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> October 24-26th MidAtl/NE Storm OBS, Forecasts, discussions and OBS
MaineJay
post Oct 17 2017, 04:05 AM
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Looks like we will be seeing a potent trough traverse the country. Perry high amplitude flow. Hopefully bringing much needed rain to many of us.


Remarkable similarities at day 8 in the deterministics.

ECMWF
Attached Image


GFS
Attached Image


http://wx.graphics/models/ecmwf/ecmwf.php

The eastern trough could linger as well.

6-10 day analogs
Attached Image


8-14 day
Attached Image


http://www.cpc.ncep.noaa.gov/products/pred...4day/analog.php


Total 10 day precip

ECMWF

Attached Image


GFS
Attached Image



Details will be ironed out, but the general idea is there. Typical timing/strength/location differences.
Ensembles
EPS
Attached Image

GFS
Attached Image

http://www.weatheronline.co.uk/cgi-bin/exp...WMO=&ZOOM=0

Nice discussion

QUOTE
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
310 AM EDT TUE OCT 17 2017

VALID 12Z FRI OCT 20 2017 - 12Z TUE OCT 24 2017

...GUIDANCE/UNCERTAINTY ASSESSMENT AND SENSIBLE WEATHER
HIGHLIGHTS/THREATS...

MODELS AND ENSEMBLES REMAIN IN REASONABLE AGREEMENT INTO THE
WEEKEND AND FORECAST CONFIDENCE IS ABOVE NORMAL DURING THIS PERIOD
WITH GOOD RUN TO RUN GUIDANCE CONTINUITY.
IN THIS PERIOD THE MAIN FORECAST FOCUS WILL BE ACROSS THE WRN US.
DEEP PACIFIC TROUGH RELATED HEIGHT FALLS SLAM INTO THE WEST COAST
FRI THAT WORK INLAND ACROSS MUCH OF THE WRN US AND ROCKIES INTO
SAT. EXPECT HEAVY PCPN OVER THE NWRN US INTO CA WITH INITIAL
MOISTURE FEED THAT COULD PRODUCE SOME RUNOFF ISSUES. DYNAMICALLY
DRIVEN/TERRAIN ENHANCED AMOUNTS THEN PROGRESS ACROSS THE N-CENTRAL
INTERMOUNTAIN WEST/ROCKIES. COOLING TEMPS WITH FRONTAL PASSAGE AND
HIGH PRESSURE SURGE WILL SUPPORT SOME HEAVY TERRAIN ENHANCED SNOWS
IN A PERIOD WITH LOWERING SNOW LEVELS. ADDITIONAL UPSTREAM PACIFIC
ENERGIES PUNCHING INTO THE NWRN US SHOULD ADD ANOTHER SHOT OF
MODERATE PCPN INTO THE REGION OVER THE WEEKEND. MID-UPPER LEVEL
RIDGE BUILDING SHOULD THEN USHER IN A DRY PATTERN WITH MODIFYING
TEMPS NEXT WEEK.

FORECAST SPREAD AND UNCERTAINTY INCREASES SIGNIFICANTLY BY LATER
WEEKEND INTO EARLY NEXT WEEK DOWNSTREAM ACROSS THE CENTRAL AND ERN
US. GUIDANCE HAS NOT OFFERED STELLAR RUN TO RUN CONSISTENCY WITH
THE FORECAST OF SUBSEQUENT STREAM SEPARATION AS AFOREMENTIONED WRN
US TROUGH ENERGIES PROGRESS INTO THE CENTRAL US AND LATER THE ERN
US. RECENT RUNS OF THE ECMWF HAS BEEN SHOWING DEEP CLOSED LOW
DEVELOPMENT THAT HAS SHIFTED OVER THE PAST FEW DAYS FROM AS FAR
WEST AS THE SRN ROCKIES TO THE SRN PLAINS THEN LOWER MS VALLEY.
ENSEMBLE SUPPORT FOR THIS HAS BEEN MARGINAL...AND THE LATEST 00
UTC ECMWF RUN CONTINUES TRENDING TO A MUCH WEAKER LOW SHIFTED
PROGRESIVELY EASTWARD UNDERNEATH INCREASINGLY DOMINANT AND NRN
STREAM TROUGH ENERGIES DIGGING SEWD FROM THE N-CENTRAL US MON TO
THE E-CENTRAL US TUE. ACCORDINGLY...THE NOTION THAT THE HIGHER
RESOLUTION ECMWF MIGHT BE CATCHING ONTO A MORE SIGNIFICANT SRN
STREAM SYSTEM NOT SHOWN WELL IN OTHER GUIDANCE HAS DWINDLED.
INSTEAD EXPECT THERE MAY WELL BE STREAM SEPARATION TO SOME
DEGREE...BUT OVERALL EXPECT A POTENT AND WAVY COLD FRONT AND
EMERGING DEEP INFLOW FROM THE GULF OF MEXICO INLAND AND NORTHWARD
TO FUEL A PROGRESSIVE AND WIDESPREAD SWATH OF MODERATE TO HEAVY
RAINS ACROSS THE CENTRAL THEN ERN US NEXT WEEK WITH THE EMERGING
NRN STREAM AMPLITUDE LIFTING ACTIVITY RAPIDLY NORTHWARD ACROSS THE
ERN THIRD OF THE NATION WITH ACTIVITY ADDING WRN ATLANTIC INFLOW
OEVR TIME. MOST GUIDANCE NOW SUPPORTS THIS SCENARIO AND WPC PROGS
WERE PRIMARILY DERIVED WITH A COMPOSITE MODEL AND ENSEMBLE BLEND
THAT DE-EMPHASIZED MUCH OF THE EARLIER ECMWF POTENTIAL.


SCHICHTEL


http://www.wpc.ncep.noaa.gov/discussions/h...php?disc=pmdepd



GYX
QUOTE
The large area of high pressure will be situated over New
England on Saturday. A further moderating trend will begin as
the flow switches to the southwest with the surface ridge moving
off the coastline. The onshore flow may lead to some low
cloudiness, especially along and near the coastline late in the
weekend. By early next week, models continue to slowly come in
better agreement with a slow moving trough approaching the east
coast. Plenty of moisture will potentially move poleward from
the tropical Atlantic and the Gulf of Mexico to bring well
needed precipitation to the region next week.

https://forecast.weather.gov/product.php?si...p;highlight=off

This post has been edited by MaineJay: Oct 24 2017, 02:00 AM


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Undertakerson
post Oct 17 2017, 04:30 AM
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I considered opening a thread for these dates - while I was posting in the LR Autumn thread. Nice job starting this one off.

We just might have two to get through before the EOTM.
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MaineJay
post Oct 17 2017, 05:08 AM
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QUOTE(Undertakerson @ Oct 17 2017, 05:30 AM) *
I considered opening a thread for these dates - while I was posting in the LR Autumn thread. Nice job starting this one off.

We just might have two to get through before the EOTM.


I saw you in here this morning and thought maybe you were opening the thread actually. Kept refreshing cause I was sure we were about to simultaneously start the topic. smile.gif


Tropical convection is really making the next few weeks look interesting. Beginning with the recurring typhoon that will usher in a new pattern. The MJO is looking robust, and we may have to watch the tropics in 2-3 weeks time for some late season Atlantic action.

The wave 1 structure is quite evident in velocity potential fields.
Attached Image

Unfortunately, the MJO website hasn't been updating normally.

http://www.cpc.ncep.noaa.gov/products/prec...k/MJO/mjo.shtml

This post has been edited by MaineJay: Oct 17 2017, 05:09 AM


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MaineJay
post Oct 17 2017, 05:41 AM
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I do believe this has organic forecasting support, but I'm too lazy this morning to dig it up. smile.gif


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Undertakerson
post Oct 17 2017, 05:56 AM
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QUOTE(MaineJay @ Oct 17 2017, 06:41 AM) *
I do believe this has organic forecasting support, but I'm too lazy this morning to dig it up. smile.gif

I believe I saw JD mentioning BSR support, but that may have been for the second system.

The second system seems to have the support of the Typhoon Rule, as Lan recurves ~22d. With a 7-10d lag thereafter, puts us near the Halloween/All Saint's Day time period.

There is, currently, a robust gale, taking a similar path to a system that would come from the TR path, so that lends some credence to the notion of a quick hitter trough in the East for this threads time period.

Attached Image


Attached Image
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MaineJay
post Oct 17 2017, 06:40 AM
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QUOTE(Undertakerson @ Oct 17 2017, 06:56 AM) *
I believe I saw JD mentioning BSR support, but that may have been for the second system.

The second system seems to have the support of the Typhoon Rule, as Lan recurves ~22d. With a 7-10d lag thereafter, puts us near the Halloween/All Saint's Day time period.

There is, currently, a robust gale, taking a similar path to a system that would come from the TR path, so that lends some credence to the notion of a quick hitter trough in the East for this threads time period.



Upon some reflection, perhaps strong frontal passage might be a better title. Using a 20 day bsr lag.

Edit: late bloomer, gulf of Maine? I could buy that.

Attached Image

Attached Image


http://www.opc.ncep.noaa.gov/Loops/index.p...s=14&loop=0

This post has been edited by MaineJay: Oct 17 2017, 06:42 AM


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Undertakerson
post Oct 17 2017, 03:01 PM
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I'll bet many in here would love this look in another 60+ days or so


Attached Image
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telejunkie
post Oct 17 2017, 09:36 PM
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QUOTE(Undertakerson @ Oct 17 2017, 04:01 PM) *
I'll bet many in here would love this look in another 60+ days or so


Attached Image

ohmy.gif Yes, yes we would. Time to brush off the ole weather bookmarks and start tracking some upper air patterns. Halloween snow storm up here is a good indication of a warm, snowless winter though. '05-'06 and '11-'12 are the two big halloween snowstorms that were followed by warm snowless winters.

Tangent time: Been following the tropical season from the bleachers. REALLY impressed with the posting you guys were doing through all those events. Really would like to think that it actually made a difference in some people's decisions through those events...obviously don't want to suggest amateur posters superceding NWS, but that that there were a lot of minor details that you two were explaining in here that gets glossed over by so many media sources and play such a pivotal role. So a quick round of applause and cheers from telejunkie


--------------------
Winter '16-'17 Winter Storms of Significance (>4")
11/20-11/22 - 8" 1/24 - 7" 4/1 - 4"
12/11 - 5" 2/9 - 8"
12/17 - 4" 2/12 - 10"
12/29 - 5" 3/14 - 18"

'09-'10 Snowfall: 76"
'10-'11 Snowfall: 117"
'11-'12 Snowfall: 44"
'12-'13 Snowfall: 62"
'13-'14 Snowfall: 88"
'14-'15 Snowfall: 99"
'15-'16 Snowfall: 26"
'16-'17 Snowfall: 85"

Telejunkie's, 100% unofficial yearly snowfall average - 77"
“We are what we pretend to be, so we must be careful about what we pretend to be” -Vonnegut
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MaineJay
post Oct 18 2017, 04:16 AM
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QUOTE(telejunkie @ Oct 17 2017, 10:36 PM) *
ohmy.gif Yes, yes we would. Time to brush off the ole weather bookmarks and start tracking some upper air patterns. Halloween snow storm up here is a good indication of a warm, snowless winter though. '05-'06 and '11-'12 are the two big halloween snowstorms that were followed by warm snowless winters.

Tangent time: Been following the tropical season from the bleachers. REALLY impressed with the posting you guys were doing through all those events. Really would like to think that it actually made a difference in some people's decisions through those events...obviously don't want to suggest amateur posters superceding NWS, but that that there were a lot of minor details that you two were explaining in here that gets glossed over by so many media sources and play such a pivotal role. So a quick round of applause and cheers from telejunkie



We really were fortunate to have the GOES16 for this tropical season. Heartbreaking to see all the destruction though.

I will likely have several projects that'll require me to be outside for a good part of the winter, so I'm indifferent in some ways. Lots of snow is fun, but little snow makes work easier. I'll still take the snow. smile.gif


This storm looks to provide rain however.

Schichtel with another solid disco

QUOTE
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
231 AM EDT WED OCT 18 2017

VALID 12Z SAT OCT 21 2017 - 12Z WED OCT 25 2017

...A VERY ACTIVE WEATHER PATTERN FOR BOTH THE WRN U.S. AND THEN
S-CENTRAL THROUGH ERN US...

...GUIDANCE/UNCERTAINTY ASSESSMENT AND SENSIBLE WEATHER
HIGHLIGHTS/THREATS...

IT REMAINS THE CASE THAT MODELS AND ENSEMBLES ARE IN REASONABLE
AGREEMENT THIS WEEKEND AND FORECAST CONFIDENCE IS ABOVE NORMAL
WITH GOOD RUN TO RUN GUIDANCE CONTINUITY. IN THIS PERIOD THE MAIN
FORECAST FOCUS WILL BE ACROSS THE WRN US. DEEP PACIFIC TROUGH
RELATED HEIGHT FALLS SLAM INTO THE WEST COAST FRI THAT WORK INLAND
ACROSS MUCH OF THE WRN US AND ROCKIES INTO SAT. EXPECT QUITE HEAVY
PCPN OVER THE NWRN US INTO CA WITH INITIAL MOISTURE FEED THAT
COULD PRODUCE SOME RUNOFF ISSUES. DYNAMICALLY DRIVEN/TERRAIN
ENHANCED AMOUNTS THEN PROGRESS ACROSS THE N-CENTRAL INTERMOUNTAIN
WEST/ROCKIES. COOLING TEMPS WITH FRONTAL PASSAGE AND HIGH PRESSURE
SURGE WILL SUPPORT SOME HEAVY TERRAIN ENHANCED SNOWS IN A PERIOD
WITH LOWERING SNOW LEVELS. ADDITIONAL UPSTREAM PACIFIC ENERGIES
PUNCHING INTO THE NWRN US SHOULD ADD ANOTHER SHOT OF MODERATE PCPN
INTO THE REGION BY LATER WEEKEND. MID-UPPER LEVEL RIDGE BUILDING
SHOULD THEN USHER IN A DRY PATTERN WITH MODIFYING TEMPS NEXT WEEK.

FORECAST SPREAD AND UNCERTAINTY INCREASES SIGNIFICANTLY DOWNSTREAM
NEXT WEEK ACROSS THE CENTRAL AND ERN US. GUIDANCE HAS NOT OFFERED
STELLAR RUN TO RUN CONSISTENCY WITH THE FORECAST EXTENT OF
SUBSEQUENT STREAM SEPARATION AS AFOREMENTIONED WRN US TROUGH
ENERGIES PROGRESS INTO THE CENTRAL US AND LATER THE ERN US. RECENT
RUNS OF THE ECMWF/UKMET HAVE IN PARTICULAR PERIODICALLY SHOWN DEEP
CLOSED LOW DEVELOPMENT THAT HAS VACILLATED OVER THE PAST FEW DAYS
FROM THE SRN ROCKIES TO MORE RECENTLY THE SRN PLAINS...LOWER MS
VALLEY...OR CENTRAL GULF COAST. ENSEMBLE SUPPORT HAS ALSO BEEN
QUITE VARIED AS POTENTIALLY QUITE AMPLIFIED NRN STREAM TROUGH
ENERGIES DIG SEWD FROM THE N-CENTRAL US MON TO THE E-CENTRAL US
TUE TO INTERACT TO SOME DEGREE. LATEST GUIDANCE TRENDS ARE THE
OPPOSITE FROM LAST NIGHT AND NOW SEEM TO SUPPORT TEMPORARY STREAM
SEPARATION WITH POTENTIAL TO INDUCE A SURFACE WAVE AND DEEPER
MOISTURE AND RAINFALL THREAT SIGNATURE. OVERALL EXPECT A POTENT
AND WAVY COLD FRONT AND EMERGING DEEP INFLOW FROM THE GULF OF
MEXICO INLAND AND NORTHWARD TO FUEL A PROGRESSIVE AND WIDESPREAD
SWATH OF MODERATE TO HEAVY RAINS ACROSS THE S-CENTRAL THEN ERN US
NEXT WEEK AS EMERGING NRN STREAM AMPLITUDE LIFTS AMPLE ACTIVITY
NORTHWARD...ADDING ATLANTIC INFLOW. WPC PROGS WERE PRIMARILY
DERIVED WITH A COMPOSITE GUIANCE BLEND TO OFFER WIDESPREAD
S-CENTRAL TO ERN US RAINFALL CONSISTENT WITH BOTH POTENTIAL AND
UNCERTAINTY. A QUICK PEEK AT THE 00 UTC ECMWF CONTINUES A
TROUBLING TREND OVER THE PAST FEW DAYS FOR 00 UTC RUNS OF THE
ECMWF TO OFFER MORE PROGRESSIVE SRN STREAM SOLUTIONS COMPARED TO
THEIR MORE STREAM SEPARATED AND CLOSED SYSTEM 12 UTC COUNTERPARTS.
A REASON FOR THIS IS UNCLEAR
.


SCHICHTEL

http://www.wpc.ncep.noaa.gov/discussions/h...php?disc=pmdepd


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MaineJay
post Oct 18 2017, 04:59 AM
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18.0z ECMWF. A fair amount of energy flying around. Very high amplitude. It'll be interesting to see how it all evolves.

H5 anomaly hour 90-204
Attached Image

MSLP hour 90-204
Attached Image

http://wx.graphics/models/ecmwf/ecmwf.php
Total precip
Attached Image


http://wx.graphics/models/ecmwf/ecmwf_usa.php


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PoconoSnow
post Oct 18 2017, 07:03 AM
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*stretches*

Been busy hurricane season but here's to tracking some winter weather


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JDClapper
post Oct 18 2017, 07:48 PM
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18z GFS

Attached Image


--------------------
Avg. Snowfall 2001-2017: 34¼"

Current Season: 0"

Last Season: 2016-2017 = 44"

Best Season: 2002-2003 = 63"

Worst Season: 2015-2016 = 7¼"

Largest Storm: 3/14/2017 = 17½"


** "MoM" Certified **
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MaineJay
post Oct 19 2017, 03:31 AM
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QUOTE(JDClapper @ Oct 18 2017, 08:48 PM) *
18z GFS



0z GFS tries to develop the trailing wave. Normally I'd be very dismissive, but with such high amplitude, blocked flow. Hard to rule it out at this lead time.

Last 5 ECMWF runs show increasingly difficult progression for the trof. To the point it now cuts off to a degree and drapes the ridge over the NE.

Love having all the frames for 12z/0z comp. smile.gif

Attached Image
http://wx.graphics/models/ecmwf/ecmwf.php


Really, really need a little rain. Fire dangers on the rise. sad.gif
https://forecast.weather.gov/wwamap/wwatxtg...her%20statement

This post has been edited by MaineJay: Oct 19 2017, 03:31 AM


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MaineJay
post Oct 19 2017, 03:39 AM
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GYX

QUOTE
While surface high pressure shifts east into the Atlantic, an
upper level ridge of high pressure will grow in amplitude over
the East Coast in response to deep troughing over the center of
the country. This will keep a warm and increasingly humid flow
of air into New England, with temperatures generally in the 70s
during the day and dewpoints rising into the 50s, buoying
nighttime lows by the beginning of next week.

Eventually the upper trough over the center of the country will
make its way eastward, and it seems likely that a more organized
pressure system will develop and move north northeast along the
eastern side of the trough generally in the direction of New
England. This will provide a good chance of rain sometime in the
Tuesday/Wednesday time period before the cooler air in the
trough arrives. Models still showing a wide range of solutions
on when and how this trough will move through, with the
potential existing for the trough to take the rest of the week
to make its way through. Thus rain chances will continue through
the week until a clearer picture can emerge from the mess.



Extended disco

QUOTE
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
300 AM EDT THU OCT 19 2017

VALID 12Z SUN OCT 22 2017 - 12Z THU OCT 26 2017

...HEAVY RAINFALL POTENTIAL IN THE ERN U.S. WITH RECORD HEAT IN
THE SOUTHWEST...


...PATTERN OVERVIEW AND GUIDANCE/UNCERTAINTY ASSESSMENTS...

MODELS AND ENSEMBLES AGREE TO DEVELOP AN AMPLIFIED FLOW PATTERN
OVER THE LOWER 48 NEXT WEEK. A LEAD CLOSED LOW POTENTIALLY PEELING
OFF FROM THE FLOW MAY AFFECT THE GULF COAST EARLY NEXT WEEK AS
DEEPENED MOISTURE FROM THE GULF OF MEXICO THEN ATLANTIC FEEDS
INCREASINGLY INLAND. GIVEN SUBSEQUENT PHASING WITH A DIGGING NRN
STREAM TROUGH...A RESULTANT NEGATIVELY-TILTED TROUGH LEADS TO
500MB HEIGHT DEPARTURES UPWARDS OF 3 STANDARD DEVIATIONS BELOW
NORMAL BY THE MIDDLE OF NEXT WEEK OVER THE EAST. THIS SCENARIO
OFFERS WIDESPREAD HEAVY RAIN POTENTIAL OVER THE E-CENTRAL TO ERN
US. PREFER A COMPOSITE 12 UTC GFS/ECMWF AND GEFS/ECMWF ENSEMBLE
MEAN GIVEN RECENT MODEL UNCERTAINTY.


AS A SHARP NEGATIVE HEIGHT ANOMALY ENCOMPASSES THE ERN THIRD OF
THE NATION...PRONOUNCED UPSTREAM RIDGING OVER THE WEST WILL USHER
IN WARM/DRY CONDITIONS TO THE REGION. A COMPOSITE GUIDANCE
SOLUTION SEEMS REASONABLE INTO TUE...BUT PREFER TO LEAN WEIGHTING
TOWARD THE MORE AMPLIFIED/LESS PROGRESSIVE ECMWF AND ECMWF
ENSEMBLE MEAN UPSTREAM OVER THE PACIFIC TO THE WEST COAST BY LATER
NEXT WEEK WITH THE ANTICIPATION OF WELL DOWNSTREAM EFFECTS FROM
THE ENTRAINMENT OF WRN PACIFIC TYPHOON LAN INTO THE WESTERLIES.


...SENSIBLE WEATHER HIGHLIGHTS/THREATS...

ZONAL FLOW OVER THE NWRN US SUPPORTS SOME HEAVY PRECIPITATION OVER
THE OROGRAPHICALLY FAVORED LOCATIONS OF THE OLYMPICS AND CASCADES
THIS WEEKEND. THIS WESTERLY FLOW REGIME SHOULD BE DEVOID OF
APPRECIABLE COLD AIR WHICH MAINTAINS SNOW OVER THE HIGHER
ELEVATIONS. WITH HEIGHTS BUILDING IN TIME...THE ACTIVE STORM TRACK
WILL LIFT UP INTO BRITISH COLUMBIA NEXT WEEK. FARTHER
EAST...WIDESPREAD RAINFALL SHOULD BE ONGOING WITH A WAVY COLD
FRONT MOVING THROUGH THE E-CENTRAL U.S. SUN/MON. ACTIVITY WILL
PICK UP IN COVERAGE AND INTENSITY AS THE SRN STREAM SHORTWAVE
DEVELOPS WITH HEAVIER AMOUNTS POSSIBLE IF THE SYSTEM SLOWS. A
HEAVY RAINFALL SIGNAL THEN EXISTS FOR THE ENTIRE ERN SEABOARD
OCTOBER 23-25 ONCE THE UPPER TROUGH STRENGTHENS AND A SERIES OF
SURFACE LOWS FORM. THERE IS A THREAT OF RUNOFF ISSUES.

SCHICHTEL


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MaineJay
post Oct 20 2017, 05:19 AM
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ECMWF has two waves. This loop only goes to 144 to compare it with the unmet.

Attached Image

Can't be certain, but the UKmet looks like it only has the initial wave and more progressive. By progressive I mean more east-west movement, where the ECMWF looks more meridional with the flow

Attached Image
http://wx.graphics/models/ukmet/ukmet.php

GFS has two waves, but the second looks further east the last few runs. Definitely east of the ECMWF.


ECMWF precip
Attached Image


WPC 7 day QPF. Bring it, we can handle that much, and it would be appreciated. smile.gif
Attached Image


This post has been edited by MaineJay: Oct 20 2017, 05:24 AM


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PoconoSnow
post Oct 20 2017, 07:04 AM
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This is the 27th

But still

I hope we see some of this come Nov Dec



I'm not sure I even remember how to forecast during an omega Greenland blocked flow. I thought it was actually all green there now....

I haven't seen a 10 day block chart look like this since I been following closely for a few years

Is it trolling or are we bout to taste a nice serving of what high latitude blocking actually does for US east coast sensible weather



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Undertakerson
post Oct 20 2017, 11:41 AM
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QUOTE(PoconoSnow @ Oct 20 2017, 08:04 AM) *
This is the 27th

But still

I hope we see some of this come Nov Dec



I'm not sure I even remember how to forecast during an omega Greenland blocked flow. I thought it was actually all green there now....

I haven't seen a 10 day block chart look like this since I been following closely for a few years

Is it trolling or are we bout to taste a nice serving of what high latitude blocking actually does for US east coast sensible weather


Ha - I had created a post in the Autumn thread about this blocking signal - and it being a long time since I could recall seeing that signal from the GFS. Then my cat jumped on the keyboard and ruined the whole thing - and I was too lazy to recreate it.
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Undertakerson
post Oct 20 2017, 11:47 AM
Post #18




Rank: F5 Superstorm
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From: Blue Mtn, N of Hbg, PA
Member No.: 21,746





CTP

QUOTE
All medium range guidance indicates that there will be a
significant digging northern stream trough that will eventually
take on a slightly negative tilt
early next week as it moves
from the upper midwest and Miss Valley to the Appalachian Mtns
and Carolina Coast.

Models have converged to indicate the center of the significant
rainfall event occurring late Monday through tuesday evening
when widespread rainfall amounts of 1-1.5 inches is
anticipated.
As the cold front pushes east through the
commonwealth Tuesday into Tuesday evening, Sfc-850 mb Lifted
Indices go slightly Negative acrs parts of Scent PA and the Susq
Valley. Pattern appears favorable for a Narrow Cold Frontal
Rainband - NCFRB (with brief gusty winds) to push through the
expansive shield of moderate to briefly heavy rainfall rates.

Current forecast rainfall amounts pose little threat for any
small stream flooding considering much higher short term FFG
values.


http://forecast.weather.gov/product.php?si...&glossary=1
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JDClapper
post Oct 20 2017, 12:04 PM
Post #19




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From: Loyalsock, PA (eastern suburb of Williamsport, PA, Elev 581')
Member No.: 26,143





QUOTE(Undertakerson @ Oct 20 2017, 12:47 PM) *


That hurts a little .. "significant trough" .. "negative tilt"

...

"heavy rainfall"

Booo laugh.gif

Would be a long weekend with little sleep, had this be a couple months later. I am getting that itch big time now. As I know many of you fine folks are too. wink.gif


--------------------
Avg. Snowfall 2001-2017: 34¼"

Current Season: 0"

Last Season: 2016-2017 = 44"

Best Season: 2002-2003 = 63"

Worst Season: 2015-2016 = 7¼"

Largest Storm: 3/14/2017 = 17½"


** "MoM" Certified **
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Black05GSR
post Oct 20 2017, 12:56 PM
Post #20




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From: Linden, NJ and Albrightsville, PA (1850ft)
Member No.: 27,529





QUOTE(JDClapper @ Oct 20 2017, 01:04 PM) *
That hurts a little .. "significant trough" .. "negative tilt"

...

"heavy rainfall"

Booo laugh.gif

Would be a long weekend with little sleep, had this be a couple months later. I am getting that itch big time now. As I know many of you fine folks are too. wink.gif


Looking at the long range GFS like


--------------------
Winter 2017/2018

PA - 11/7 (1.5");
Total: 1.5"

NJ -
Total: 0"
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