October 28th-? MidAtl/NE Cool Spell, Cognition: Long range [7-10 Days Out] Options

[WEATHERFREAK]

Now that models have started to come into better agreement. I've decided to start this thread. But just to be on the safe side, I've opted to label it cool rather then cold for now.

Discuss your thoughts below...

This post has been edited by WEATHERFREAK: Oct 21 2011, 09:27 AM

[jdrenken]

The SE is a completely different region that has their own topics.

[WEATHERFREAK]

[NYCSuburbs]

These are yesterday's images and are no longer valid, considering that the models significantly backed away from the strong storm. These are today's HPC maps:

[sw03181]

I posted this over in the 27th-30th event thread. 12z GFS has Hartford barely making it outta the 40's

111028/1500Z 123 32014KT 40.5F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
111028/1800Z 126 32012KT 43.7F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
111028/2100Z 129 31008KT 39.6F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
111029/0000Z 132 31005KT 33.4F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
----------------------------------------------+----++-------------++--------------++-------------++-----------+---+---
111029/0300Z 135 29003KT 31.6F UP 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
111029/0600Z 138 27003KT 31.8F UP 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
111029/0900Z 141 VRB02KT 31.8F UP 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
111029/1200Z 144 VRB02KT 34.3F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
----------------------------------------------+----++-------------++--------------++-------------++-----------+---+---
111029/1500Z 147 21006KT 46.9F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
111029/1800Z 150 22008KT 50.9F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
111029/2100Z 153 20006KT 44.8F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
111030/0000Z 156 22006KT 37.8F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
----------------------------------------------+----++-------------++--------------++-------------++-----------+---+---
111030/0300Z 159 26005KT 38.1F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
111030/0600Z 162 29005KT 34.5F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
111030/0900Z 165 28007KT 34.9F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
111030/1200Z 168 30009KT 34.5F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
----------------------------------------------+----++-------------++--------------++-------------++-----------+---+---
111030/1500Z 171 32015KT 43.3F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
111030/1800Z 174 32013KT 45.7F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
111030/2100Z 177 33007KT 42.8F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
111031/0000Z 180 33005KT 35.2F 0:1| 0.0|| 0.0 0.000|| 0.00 0.00|| 0.00 0.00|| 0.00 0| 0| 0
==================================================
==================================================
================

http://www.meteor.iastate.edu/~ckarsten/co...s&site=kbdl

[WEATHERFREAK]

they have the high too far to the north(especially after the 12z suites).

[jdrenken]

they have the high too far to the north(especially after the 12z suites).

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
330 PM EDT SUN OCT 23 2011

VALID 12Z WED OCT 26 2011 - 12Z SUN OCT 30 2011

THE UPDATED PRELIM USED A BLEND OF THE 00Z/23 ECENS/GEFS MEANS AS
HAVING THE BEST CONTINUITY FROM YESTERDAY IN A TRANSITIONAL
PATTERN. FINAL PROGS MADE ONLY MINOR CHANGES FROM EARLIER PRELIMS
NEAR THE E COAST AND IN THE WRN ATLANTIC.

TODAYS 00Z AND 12Z DETERMINISTIC MODELS AND ENSEMBLES HAVE PRETTY
MUCH ABANDONED THE IDEA OF A CONSOLIDATED UPPER TROF MOVING ACROSS
THE SRN PORTION OF THE LOWER 48. THAT SCENARIO WOULD HAVE
GENERATED A HUGE FRONT RANGE SNOWSTORM IN CO/NERN NM...AND ANOTHER
WIDESPREAD HEAVY RAIN EVENT FOR THE ERN CONUS. WE ARE STILL
LOOKING FOR A MAJOR PCPN EVENT FROM THE OH VLY INTO THE NERN
STATES...BUT ONLY LIGHT PCPN ACROSS THE SERN STATES EXCEPT FOR
MODERATE TO HEAVY OVER FL.

BY KEEPING MORE ENERGY IN THE NRN STREAM ...MODELS HAVE STRONGLY
SPED UP THE MOVEMENT OF THE MAIN SYS FOR LATE THIS WEEK FROM
YESTERDAYS GUIDANCE ACROSS THE LOWER 48. THERE IS JUST ENOUGH SRN
STREAM ENERGY LEFT TO SUPPORT LOCALLY HEAVY SNOW WED INTO EARLY
THU IN CO/NE NM...BUT CERTAINLY NOT ON THE SCALE OF YESTERDAYS
MODEL CONSENSUS. IN THE E...INSTEAD OF A CLOSING OFF UPPER LOW
KY/TN FRI...WE EXPECT A FLAT WAVE OVER THE MID ATLANTIC THU RACING
TO THE CANADIAN MARITIMES FRI AM...SUPPORTED BY NRN STREAM ENERGY.


THE NEW 12Z GFS HAS ACTUALLY TRENDED BACK TOWARDS A MORE VIGOROUS
SRN STREAM SYS OVER THE 4 CORNERS REGION BY WED EVE. ITS SRN
STREAM SYS THEN SPLITS OFF FROM ITS POSITIVELY TILTED NRN STREAM
COUNTERPART...MOVING TO THE LOWER MS VLY BY DAY 5 WHILE THE NRN
STREAM REMAINS DOMINANT/PROGRESSIVE. THE GFS SCOOTS A SURFACE WAVE
ASSOCIATED WITH THE NRN STREAM ACROSS UPPER PORTIONS OF THE OH
VLY/MID ATLANTIC ON THU. ONCE THAT WAVE IS GONE...THE GFS SHOWS
DRY HIGH PRES AND FAST MOVING SHORTWAVES DOMINATING THE WEATHER
PATTERN N OF ABOUT 36 DEGREES LATITUDE. THE 12Z CANADIAN SHOWS
MORE OF A GFS SCENARIO BUT GETS ABOUT 18 HOURS SLOWER WITH THE SRN
STREAM SYS BY DAY 5. WE THINK THAT THE GFS IS MISSING SOME
INTERACTION WITH THE NRN STREAM AND HAS TOO LITTLE PCPN AS A
RESULT.

THE UKMET DEPICTS A DIFFERENT SCENARIO ENTIRELY AFTER THU DAY 4.
IT AMPLIFIES A SHORTWAVE INTO THE MID AND UPPER MS VLY IN SUCH A
FASHION BY FRI AS TO PICK UP THE WEAKENING SRN STREAM SYS. THIS
GIVES A HEAVY PCPN PATTERN WHICH SHOWS A MAX FROM NRN AR ALONG THE
OH RIVER TO LONG ISLAND. THE MAX PRECIP AXIS OF THE ECMWF THRU DAY
4 IS FARTHER N THAN OUR EARLIER THINKING...WHICH WAS FROM TX THRU
THE OH VLY...BUT HAS SUPPORT FROM THE UKMET IN BREAKING OUT MORE
PCPN OVER OK WED OR WED NIGHT. THE UKMET GOES TO EXTREME AMPLITUDE
BY SAT DAY 6...CLOSING OFF A 540DM CLOSED LOW OVER THE UPPER OH
VLY. THERE APPEARS TO BE TOO MUCH UPSTREAM FLOW SAT FOR THIS TO
HAPPEN. THE UKMET PCPN SCENARIO MIGHT HAVE SOME SKILL THRU DAY 4
BUT IS PROBABLY TOO GENEROUS OVERALL.

FINALLY...THE NEW 12Z/22 ECMWF GIVE THE BEST SUPPORT TO OUR
EARLIER THINKING WITH ONLY MINOR DIFFERENCES IN THE
TIMING/INTENSITY OF SYS OVER THE LOWER 38 THRU THE PERIOD. THE
ECMWF DOES LOWER HEIGHTS SUBSTANTIALLY OVER THE NE QUADRANT OF
NATION DAY 6 AS DOES THE UKMET...THOUGH NOT AS DRASTICALLY. ITS
SURFACE AND PCPN PATTERN GENERALLY SUPPORTS CONTINUITY,

FLOOD

[WEATHERFREAK]

That still does not warrant stalling the front over the Florida Keys on Saturday. There still will be plenty of energy and hight falls behind this boundary. But only as strong as last weeks front(but models will probably flip back given the overall senario).

[jdrenken]

That still does not warrant stalling the front over the Florida Keys on Saturday. There still will be plenty of energy and hight falls behind this boundary. But only as strong as last weeks front(but models will probably flip back given the overall senario).

You labeled the thread as cool and not cold yourself, yet are quick to complain about the HPC under doing it?

They are going with a cool pattern themselves. Accept it and move on.

EDIT: We are getting later into the fall to which the impact of such a cold front will not have the same drastic results as it would've a month ago.

Perfect example is shown looking at the GEFS 2m temps. The majority is seeing between 6-9 degrees below normal in the MidAtl/NE in the later push of the cold air and 9-12 in the front push.

[jdrenken]

HPC Probability of 32 Degrees

28th 12Z


29th 12Z

[SnowMan11]

GFS ensembles. BRRR.

[sw03181]

18z soundings for BDL:
http://www.meteor.iastate.edu/~ckarsten/co...m&site=kbdl

There's a good chance folks just north of I95 get their first frost sometime after Halloween (if they havent already).

[jdrenken]

Today's NAEFS

Attached thumbnail(s)

 

[Fire/Rescue]

I continue to hear about this sharp cold front, the big cool down and how "Chilly/Cold" it's gonna end up being once the storm(s) exit the area towards the end of this week and weekend. Been hearing alot of chatter with regard to how COLD it's gonna be for the "Trick or Treaters" this year for the Mid-Atlantic and NE.....however I am just not seeing it, at least according to my area forecast.

My forecast this weekend.....

NWS carries highs in the Mid 50's and Sunny all weekend with Lows in the Upper 30's
Accu-Wx is pretty much the same however holding Highs in the Low 50's and Mostly Cloudy, actually Accu-Wx's 15 day extended does not show any true COLD air either....pretty much just 50's and 60's until the end of the period when temperatures only drop back into the upper 40's for highs.

NWS
Accu-Wx

[sw03181]

This mornings 6z GFS soundings for BDL are even colder
http://www.meteor.iastate.edu/~ckarsten/co...m&site=kbdl

[LoveNYCSnow]

I continue to hear about this sharp cold front, the big cool down and how "Chilly/Cold" it's gonna end up being once the storm(s) exit the area towards the end of this week and weekend. Been hearing alot of chatter with regard to how COLD it's gonna be for the "Trick or Treaters" this year for the Mid-Atlantic and NE.....however I am just not seeing it, at least according to my area forecast.

My forecast this weekend.....

NWS carries highs in the Mid 50's and Sunny all weekend with Lows in the Upper 30's
Accu-Wx is pretty much the same however holding Highs in the Low 50's and Mostly Cloudy, actually Accu-Wx's 15 day extended does not show any true COLD air either....pretty much just 50's and 60's until the end of the period when temperatures only drop back into the upper 40's for highs.

NWS
Accu-Wx

The forecasters are usually somewhat conservative in situations like this and fair reason as the models usually moderate but as of now they are showing widespread 40s for highs all the way down to the Northern MA, not sure about Baltimore, and then it shows near freezing all the way near the I95 corridor but again there is potential for moderation. Even with that said, I'm pretty sure highs in the low to mid 50s, lows in the upper 30s even in itself is below normal near Baltimore this time of year.

[jdrenken]

One person's "cold" is another person's "cool".

Here are the averages for BWI in October.

DY NMX NMN NPCP NS RMX /YEAR LOMX/YEAR RMN /YEAR HIMN/YEAR MXPCP YEAR MXSN YEAR
25 64 42 0.10 0.0 77 /1931+ 47 /2005+ 28 /1962 64 /1971 2.22 1872 T 1930
26 64 42 0.10 0.0 81 /1978 45 /1962 27 /1952 62 /2010+ 3.18 1943
27 63 42 0.11 0.0 82 /1963 44 /1976+ 29 /1988+ 67 /2010 1.99 2003
28 63 41 0.11 0.0 87 /1919 47 /1976 27 /1976 64 /1947 1.92 1972
29 63 41 0.11 0.0 82 /1946+ 46 /1925+ 26 /2001 65 /1946 1.51 1973+ T 1952+
30 63 41 0.11 0.0 83 /1946 39*/2002 26 /1965 65 /1918 0.97 1898 2.5*1925
31 62 41 0.11 0.0 85 /1946 41 /1925 25*/1966 66 /1971 1.50 1926

[jdrenken]

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
938 AM EDT MON OCT 24 2011

VALID 12Z FRI OCT 28 2011 - 12Z MON OCT 31 2011

DURING THE MEDIUM RANGE PERIOD EXPECT A MODERATELY PROGRESSIVE
PATTERN WHICH OVER A MULTI-DAY TIME FRAME SHOULD AVERAGE OUT TO
BROAD CYCLONIC FLOW WITH AN AXIS OVER THE ERN HALF OF THE CONUS.
CONFIDENCE IN GUIDANCE EVOLUTION OF EACH INDIVIDUAL SHRTWV IS
AVERAGE TO BELOW AVERAGE DUE TO THE SENSITIVITY TO ACCURATE TIMING
OF UPSTREAM AND DOWNSTREAM FEATURES.

EXAMINING FEATURES FROM EAST TO WEST... SOLNS STILL DISPLAY A
DECENT AMOUNT OF SPREAD WITH THE WAVE FCST TO TRACK OFF THE EAST
COAST AROUND LATE DAY 3 THU. THE 00Z ECMWF/ECMWF MEAN PROVIDE THE
BEST INTERMEDIATE TRACK BETWEEN THE FARTHEST LEFT 00Z GEFS MEAN
AND MORE SUPPRESSED UKMET/CANADIAN. THE 00Z/06Z GFS RUNS ARE NOT
TOO FAR FROM THE ECMWF TRACK BUT ARE A LITTLE FASTER. UPSTREAM
THERE IS A DECENT MAJORITY OPERATIONAL CLUSTER SUGGESTING THAT
MORE SHRTWV ENERGY WILL BE OVER THE SRN ROCKIES AND VICINITY AT
THE START OF THU THAN FCST BY LATEST GFS RUNS. SOME GEFS MEMBERS
ALSO FAVOR THE ECMWF CLUSTER THOUGH NOT IN SUFFICIENT NUMBERS TO
BE WELL REFLECTED IN THE CORRESPONDING MEAN. THIS ENERGY IS
EXPECTED TO COMBINE WITH AMPLIFYING WRN CANADA/NRN ROCKIES FLOW BY
SAT TO YIELD AN ERN CONUS TROF WHOSE PRECISE SHARPNESS WILL
DETERMINE THE TRACK OF ASSOC SFC LOW PRESSURE THAT MAY AFFECT SOME
AREAS OVER THE EAST. THE 00Z/06Z GFS AND 00Z ECMWF/UKMET ALL
INDICATE A MORE DEVELOPED WRN ATLC SYSTEM THAN SHOWN IN LATEST
ENSEMBLE MEANS WITH ONLY THE 00Z CANADIAN MORE SUPPRESSED. THE
STRONGEST AND MOST WWD ECMWF/UKMET ARE WITHIN THE ENSEMBLE
SPREAD... BUT OCCASIONAL TENDENCY TOWARD OVER-DEVELOPMENT IN THE
UKMET AND LACK OF CONTINUITY IN THE ECMWF AND OTHER MODELS
CURRENTLY FAVOR A COMPROMISE APPROACH AMONG THE 00Z ECMWF/00Z
GFS/06Z GFS PERHAPS LEANING A LITTLE MORE TOWARD THE ECMWF TRACK
BY EARLY SUN ONCE THE SYSTEM REACHES JUST S OF THE CANADIAN
MARITIMES.

THE NEXT SHRTWV IN THE SERIES IS EXPECTED TO REACH THE WEST COAST
AROUND FRI. THE 06Z GFS COMPARES LESS FAVORABLY TO OTHER SOLNS AS
IT DISPLAYS A SHARPER/MORE AMPLIFIED FEATURE ON FRI... THOUGH
EXTREME TRAITS DIMINISH THEREAFTER. AS THIS SHRTWV MOVES INLAND
DURING THE WEEKEND INTO EARLY NEXT WEEK SOME TIMING/DETAIL SPREAD
DEVELOPS WITH GFS RUNS LEANING TO THE PROGRESSIVE SIDE OF THE
SPREAD AND THE 00Z ECMWF MEAN TO THE SLOW AND SWWD ELONGATED SIDE.
THE 00Z ECMWF IS BETWEEN THE TWO. NEGATIVE HGT ANOMALIES THAT
MULTI-DAY MEANS INDICATE TO VARYING DEGREES OVER THE NRN ATLC BY
D+8 TELECONNECT TO A POSITIVELY TITLED MEAN TROF OVER THE CNTRL
CONUS... FAVORING SOME INCLUSION OF THE ECMWF MEAN. HOWEVER NEG
HGT ANOMALIES TO THE N OF ALASKA OFFER POTENTIAL FOR A SOMEWHAT
FLATTER/FASTER SOLN. THE FINAL SYSTEM OF THE PERIOD SHOULD REACH
WRN CANADA AND THE PAC NW AROUND SUN-MON WITH THE 00Z GFS THE
NOTABLE EXTREME FOR ITS AMPLITUDE.

THE ABOVE CONSIDERATIONS FAVOR A BLEND OF THE 00Z ECMWF/ECMWF MEAN
AS THE PRIMARY STARTING POINT FOR THE DAYS 3-7 THU-MON FCST...
WITH 20 PCT OF THE LESS PROBABLE GEFS MEAN ALSO INCLUDED IN LIGHT
OF THE FCST UNCERTAINTY. MINOR ADJUSTMENTS TO THE INITIAL BLEND
WERE MADE TO ACCOMMODATE PREFERENCES FOR THE MID-PERIOD SYSTEM
NEAR THE EAST COAST.

RAUSCH

[WEATHERFREAK]

It appears the models have gone back to an amplified EC trough(through not as extreme).

[Fire/Rescue]

The forecasters are usually somewhat conservative in situations like this and fair reason as the models usually moderate but as of now they are showing widespread 40s for highs all the way down to the Northern MA, not sure about Baltimore, and then it shows near freezing all the way near the I95 corridor but again there is potential for moderation. Even with that said, I'm pretty sure highs in the low to mid 50s, lows in the upper 30s even in itself is below normal near Baltimore this time of year.

No doubt as it will be (Chilly) I guess I was just antisipating it to be COLD is all, but hey this sort of weathr and temperatures are only just around the corner now.