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First Taste of Winter for Plains and Northeast
10-02-2012, 03:16 PM (This post was last modified: 10-02-2012 03:32 PM by Joe-Nathan.)
Post: #1
First Taste of Winter for Plains and Northeast
Looks like the Plains and the Northeast will be getting there first snow this weekend:

OCT 6, 2012:

[Image: GFS_3_2012100212_F84_SNOWIN_SURFACE.png]

OCT 7, 2012:

[Image: GFS_3_2012100212_F120_SNOWIN_SURFACE.png]


Not much, but it aught to get some people excited.


THE DAY 3 HPC CHART:

[Image: day3_composite.gif]

AND THE DISCO:

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
348 AM EDT TUE OCT 02 2012


VALID 12Z TUE OCT 02 2012 - 12Z FRI OCT 05 2012

Quote:DAYS 1 AND 2...

...MT/WY...

NO MAJOR CHANGES TO THE PREV THINKING. A ROBUST MID LVL SHRTWV
TROF WILL SEWD ACROSS THE NWRN U.S. LATER TUES AND CONTINUING
THROUGH WED. THE TROF WILL DRIVE A STRONG COLD FRONT ACROSS THE
NRN ROCKIES AND WELL SEWD ACROSS THE NRN PLAINS...LEADING WAY FOR
A SURGE OF THE COLDEST AIR OF THE SEASON SO FAR. COLD HIGH
PRESSURE WILL NOSE SWD DOWN THE LEE OF THE CANADIAN ROCKIES VERY
QUICKLY IN BEHIND THE FRONT...FILTERING SWD ACROSS WRN MT AND AND
NRN WY...AND SETTING THE STAGE FOR A PERIOD OF MOIST LOW LVL
UPSLOPE FLOW. THIS COUPLED WITH MOIST AND COLD CYC FLOW
ALOFT...ALONG EMBEDDED VORT ENERGY DROPPING SEWD OVER THE HIGHER
TERRAIN...SHOULD ALLOW FOR A PERIOD OF NUMEROUS SNOW SHOWERS TO
DEVELOP BEGINNING LATER TUES AFTN INVOF GLACIER NATIONAL PARK AND
THEN PROGRESSING SWD AND OVERSPREADING THE ROCKY MOUNTAIN
FRONT/BELT MTNS/BIG SNOWY MTNS TUES NIGHT. SNOW SHOWERS SHOULD
DEVELOP AND OVERSPREAD THE PRYOR MTNS/BIG HORN MTNS ON WED AND
CONTINUE INTO EARLY THURS. SNOWFALL TOTALS OF 4 TO 8 INCHES WITH
ISOLD HEAVIER AMTS ARE POSSIBLE THROUGH WED INVOF GLACIER NATIONAL
PARK AND DOWN THE ROCKY MTN FRONT INTO THE BELT MTNS THROUGH EARLY
THURS. EXPECTING TOTALS OVER NRN WY TO BE ON THE ORDER OF 2 TO 4
INCHES WITH SOME ISOLD HEAVIER AMTS. CANNOT RULE OUT SOME LGT
SNOWFALL EXTENDING OUT INTO THE CNTRL MT HIGH PLAINS GIVEN THE
EXPECTED COLD AIR ADV...BUT ONLY VERY LGT ACCUMS ARE EXPECTED ATTM
OUT INTO THE HIGH PLAINS.

...CNTRL/NERN ND INTO EXTREME NWRN MN...

LOW PRESSURE IS EXPECTED TO BE DEEPENING LATE WED OVER EXTREME
SERN SD AND BY EARLY THURS SHOULD BE MOVING INTO S CNTRL
MN...ALONG WITH AN INTENSIFYING/EXPANDING MID LVL DEFORMATION ZONE
OVER CNTRL/ERN ND AND NWRN MN. EXPECTING AN EXPANDING SHIELD OF
MDT TO HVY RAIN INITIALLY ON WED AS THE SYS DEEPENS...BUT
SUFFICIENT DYNAMIC COOLING ALOFT COUPLED WITH STRENGTHENING LOW
LVL COLD AIR ADV AROUND THE W SIDE OF THE ADVANCING SFC LOW SHOULD
ALLOW RAIN TO MIX WITH AND THEN GRADUALLY CHANGE OVER TO SNOW WED
NIGHT. THIS WILL ESP BE THE CASE OVER NERN ND AND FAR NWRN MN
WHERE THE COMMA-HEAD FEATURE WILL BE THE STRONGEST AND WILL BEGIN
PIVOTING OVER THE REGION BY EARLY THURS AS COLD AIR ADV
INTENSIFIES. IN FACT...IT APPEARS THAT THE UVVS/PCPN RATES WILL
BECOME RATHER INTENSE OVER THIS REGION FOR A WHILE LATE WED
NIGHT/EARLY THURS...AND SO ONCE THE CHANGEOVER TO SNOW
OCCURS...EXPECT IT TO BECOME MDT TO HVY...AND THEREFORE SUPPORTIVE
OF A SWATH OF ACCUM SNOWFALL DESPITE MARGINAL BNDRY LYR TEMPS. A
LOW RISK OF 4 INCH AMTS WILL BE INDICATED ATTM OVER CNTRL/NERN ND
AND EXTREME NWRN MN.

THE PROBABILITY OF SIGNIFICANT ICING IS LESS THAN 10 PERCENT.


DAY 3...

...MT/WY...

COLD HIGH PRESSURE FILTERING SOUTH OVER THE NRN HIGH PLAINS WILL
CONTINUE TO BANK UP AGAINST THE ERN SLOPES OF THE NRN ROCKIES.
EXPECT SOME ADDITIONAL LGT SNOW SHOWER ACTIVITY OVER SRN MT AND
NRN WY...ESP INVOF THE BELT AND BIG HORN MTNS. ADDITIONAL SNOWFALL
ACCUMS OF A COUPLE INCHES ARE POSSIBLE.

...NERN ND INTO NRN MN...

THE LATEST MODEL GUIDANCE SHOWS A CLUSTERING OF SOLNS FAVORING AN
INTENSE EARLY SEASON WINTER STORM OVER THE FAR UPR MS VLY WITH A
FOCUS ON NRN MN THURS INTO EARLY FRI. A MID LVL TROF IS EXPECTED
TO CLOSE OFF OVER N CNTRL MN BY MIDDAY THURS IF NOT SOONER...WITH
SFC LOW PRESSURE INTENSIFYING AS IT MOVES INTO FAR NERN MN OR OVER
THE WEST END OF LAKE SUPERIOR THURS NIGHT AND ON ITS WAY INTO SWRN
ONTARIO EARLY FRI. A STRONG MID LVL DEFORMATION ZONE WITH INTENSE
DEEP LYR FRONTOGENETIC FORCING IS EXPECT TO PIVOT OVER MUCH OF FAR
NERN ND AND ESP NRN MN THURS INTO THURS NIGHT. THE COMMA-HEAD
SHOULD THEN SLOWLY EXIT NEWD INTO ONTARIO EARLY FRI...BUT THERE
WILL STILL BE MOIST COLD CYC FLOW LINGERING OVER THE REGION IN ITS
WAKE. PCPN INITIALLY IN THE FORM OF MDT TO HVY RAIN WILL MIX WITH
AND CHANGE OVER TO ALL SNOW OVER NERN ND AND NWRN MN THURS MORNING
IF IT HAS NOT ALREADY DONE SO...AND THEN THE REMAINDER OF NRN MN
BY LATE THURS AFTN AND EVENING AS A COMBINATION OF STRONG DYNAMIC
COOLING ALOFT ASSOCD WITH INTENSE UVVS...AND STRONG COLD AIR ADV
IN THE BNDRY LYR ENSUES AROUND THE W SIDE OF THE DEEPENING SFC
LOW. MOISTURE AND ENERGY PIVOTING OVER THIS AREA THURS NIGHT WILL
ALLOW SNOW TO CONTINUE BEFORE THEN TAPERING TO SNOW SHOWERS EARLY
FRI. SNOWFALL ACCUMS OF 4 TO 8 INCHES WITH ISOLD HEAVIER AMTS ARE
POSSIBLE OVER NRN AND NWRN MN ESP NEAR THE CANADIAN BORDER.

THE PROBABILITY OF SIGNIFICANT ICING AND/OR SNOW IS LESS THAN 10
PERCENT.


ORRISON

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10-03-2012, 11:17 AM
Post: #2
First Taste of Winter for Plains and Northeast
So will TWC (dumbasses) name this one ATHENA?

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