Some NWS forecast discussions about next week/GFS

[Anonymous]

Looks to rival some if the cold I remember from the 80s!!!!!!!!!!

NWS Tampa...
MODELS ARE COMING IN MUCH...MUCH DEEPER WITH NEXT SYSTEM FOR
SUNDAY AND MONDAY. GFS AND DGEX IN LINE WITH MASSIVE HEIGHT FALLS
OVER THE EASTERN U.S. AS ANOMALOUS UPPER LOW CUTS OFF IN HIGHLY
AMPLIFIED FLOW. FORECAST 850 MB TEMPS AND LOW LEVEL THICKNESSES
SHOCKINGLY COLD ON LATEST GFS FOR MONDAY...IN FACT THE COLDEST I HAVE
EVER SEEN IN MY 10+ YEARS DOWN HERE! WERE THIS TO VERIFY...A MAJOR
FREEZE WOULD OCCUR THROUGH THE ENTIRE FA. FORTUNATELY...WE ARE STILL
TALKING ABOUT 5 DAYS OUT...SO WILL JUST GO WITH A TYPICAL COLD
OUTBREAK FOR NOW AND KEEP A VERY CLOSE EYE ON FUTURE TRENDS.

NWS Jax...
.LONG TERM...WEAK FRONT PASSES THE AREA LATE FRI OR EARLY SAT...THEN
NEXT ARCTIC BLAST PUSHES THRU SUN AS BOMB DEVELOPS ALONG E SEABOARD.
00Z MEX MOS HIGH TEMPS ON MON ARE A WHOPPING 11 DEGS LOWER THAN
PREVIOUS RUN...WITH TUE MINS SOME 15 DEGS COLDER. WHILE THESE TEMPS
ARE CERTAINLY POSSIBLE...WILL EASE TEMPS IN THIS DIRECTION SO THAT
LATER SHIFTS CAN LOOK FOR MORE CONSISTENCY. SUFFICE IT TO SAY THAT
TEMPS LATE IN THE WKND AND EARLY NEXT WEEK WILL BE MUCH BELOW NORMAL
ONCE AGAIN.


NWS Tallahassee...
LONG TERM...FRIDAY THROUGH TUESDAY.
LATEST MEX GUIDANCE IS SHOWING SUBSTANTIALLY COLDER TEMPERATURES
MONDAY AND TUESDAY COMPARED TO WHAT IS IN GRIDS. NOT WANTING TO
COMPLETELY JUMP ON THE LATEST GUIDANCE...WE TOOK AN AVERAGE BETWEEN
OUR INHERITED FORECAST AND THIS GUIDANCE.

Peachtree City, Ga...

.LONG TERM...
NEW GFS NOW ADVERTISING A BIG CHANGE SUNDAY THROUGH MONDAY WITH VERY
COLD AIR MOVING INTO THE CWA. THE NEW MOS GUIDANCE IS SHOWING
WIDESPREAD TEMPS IN THE TEENS ALL THE WAY INTO CENTRAL GA BY MONDAY
MORNING. WHILE THIS MAY BE TOO COLD...WILL START TRENDING THE TEMPS
DOWN SUNDAY THROUGH MONDAY. WILL ALSO MOVE THE PRECIP ONSET FORWARD
BY 6 HOURS BEGINNING LATE SATURDAY NIGHT. MOST OF THE PRECIP SHOULD
BE LIGHT AND IN THE FORM OF LIGHT RAIN/LIGHT SNOW/FLURRIES THROUGH
MONDAY. &&


Charleston, SC...

.LONG TERM /FRIDAY THROUGH TUESDAY/...THE WEAK COASTAL TROF ON FRI
WILL BRING SOME CLOUDS TO THE FORECAST...BUT FOR THE MOST PART
EXPECT LOW POP OVER THE WATER. WILL CONTINUE THE 20 POP FOR A
SECTION OF THE SC COASTAL ZONES. THE COMBINATION OF A WAVE COMING
OUT OF CANADA AND ANOTHER WAVE MOVING EAST OUT OF THE SW U.S. WILL
COMBINE TO SET UP ANOTHER TROF OVER THE EAST COAST EARLY SATURDAY.
HIGH PRESSURE MOVES IN ONCE AGAIN ALBEIT WEAKER THAN THE PREVIOUS
HIGH. A STRONGER TROF IS FORECAST TO DIG SOUTHEAST THROUGH THE
UPPER MS AND OHIO VALLEYS ON SUN. WITH A SURFACE LOW FORECAST TO
FORM OFF THE MID ATLANTIC COAST...WRAP AROUND MOISTURE IN THE FORM
OF CLOUDS ALONG WITH COLD TEMPS COULD MAKE MON VERY COLD INDEED.
NEWEST MEX GUIDANCE IS SOME 10 DEGREES COOLER FOR MON WITH HIGHS IN
THE UPPER 30S. NOT READY TO MAKE THE LEAP INTO FORECASTING S- FOR
THE AREA AS POPS ARE TOO SMALL. BUT IT IS SOMETHING WE HAVE TO
WATCH OVER THE NEXT SEVERAL MODEL RUNS. AS SYSTEM EXITS...WILL
LIKELY LEAVE TUE MORNING WITH LOWS WELL INTO THE 20S.

For fun, I checked the GFS for Cecil Field, Fla (2 miles from me) A low of 11 and high of 31 for the 20th seems a tad chilly to me.

Code: Select all

CECIL FIELD   
 KVQQ   GFSX MOS GUIDANCE  12/15/2004  0000 UTC                       
 FHR  24| 36  48| 60  72| 84  96|108 120|132 144|156 168|180 192     
 WED  15| THU 16| FRI 17| SAT 18| SUN 19| MON 20| TUE 21| WED 22 CLIMO
 X/N  53| 29  61| 42  66| 40  64| 34  59| 10  47| 20  57| 40  65 39 66
 TMP  38| 34  49| 44  51| 43  49| 38  40| 11  31| 23  44| 49  53     
 DPT  28| 29  44| 43  46| 40  40| 32  18|  4  16| 20  39| 49  43     
 CLD  CL| CL  PC| PC  PC| OV  OV| PC  PC| CL  CL| OV  OV| OV  OV     
 WND  12|  7   9|  4   6|  6   9|  7  16| 10  14|  8  10|  5  12     
 P12   2|  4  10| 20  15| 24  24| 13  17| 16  11|  5   9| 15  20999999
 P24    |     15|     22|     34|     17|     21|     14|     26    26
 Q12   0|  0   0|  0   0|  0   0|  0   0|  0   0|  0    |             
 Q24    |      0|      0|      0|      0|      0|       |             
 T12   1|  0   0|  2   2|  4   2|  3   0|  0   0|  0   2|  2   3     
 T24    |  1    |  3    |  4    |  3    |  2    |  0    |  3         
 PZP   2|  2   6|  0   0|  0   0|  0   2|  6   6| 10   5|  2   1     
 PSN  10|  0   0|  0   0|  0   0|  0   4| 26   9| 21   8|  0   0     
 PRS  15|  0   1|  0   0|  1   3|  1   9|  4   8|  1   3|  2   1     
 TYP   R|  R   R|  R   R|  R   R|  R   R|  R   R|  R   R|  R   R     
 SNW    |      0|      0|      0|      0|       |       |           

[Scorpion]

Amazing! If this verifies my area can be in the 20's! Hopefully in time for Christmas .

[PurdueWx80]

The X/N row is for maximum and minimum temperatures, so the low is actually 10! and the high is 47 that day.

[Brent]

BMX:

NEXT SHORTWAVE TROF BEARS WATCHING A LITTLE CLOSER...AS GFS
INDICATES THAT IT MAY GENERATE ENOUGH LIFT TO BRING PRECIP CHANCES
CLOSER TO THE STATE SATURDAY NIGHT. WILL GO AHEAD AND PULL THE
TRIGGER ON THE FIRST MENTION OF WINTRY PRECIP IN OUR CWA THIS
WINTER: SLIGHT CHANCE OF RAIN OR SNOW IN THE NORTHEASTERN ZONES
SATURDAY NIGHT. NOTHING TO RUN OUT AND EMPTY THE GROCERY STORES
ABOUT...THOUGH.

00Z GFS SOLUTION FROM SUNDAY THROUGH THE REST OF THE FORECAST PERIOD
IS HIGHLY SUSPECT -- OR AT LEAST CONFIDENCE IS VERY LOW. THAT BIG
CUTOFF LOW ALONG THE EAST COAST SEEMS LIKE AN EXTREME SOLUTION WHEN
LOOKING AT THE ENSEMBLES...AND WE CERTAINLY WANT TO SEE MORE IN
THE WAY OF CONSISTENCY (AND LESS IN THE WAY OF MODEL SPREAD) BEFORE
WE JUMP ON A SOLUTION THIS AMPLIFIED. THOSE 10 DEGREE LOWS PREDICTED
BY THE 00Z MEX OUTPUT SEEM UNREALISTIC...ESPECIALLY CONSIDERING HOW
THE MODELS OVERFORECASTED THE STRENGTH OF THE CURRENT AIRMASS (SEE --
I TOLD YOU WE WOULD REFERENCE IT IN THE FUTURE).

SNOW MONGERS AND THOSE -removed- A POSSIBLE WHITE CHRISTMAS ARE NO
DOUBT GETTING A KICK OUT OF THE 00Z GFS SOLUTION FOR TUESDAY NIGHT
AND WEDNESDAY. EVEN THOUGH THAT'S JUST BEYOND THE RANGE OF THIS
FORECASTING PACKAGE...IT WILL PROBABLY GET SOME AIR PLAY AND SOME
RUMORS GOING. WILL WATCH THE 06Z AND 12Z RUNS (AND ALL FUTURE
RUNS...FOR THAT MATTER) WITH GREAT INTEREST.

HUN:

UPPER FLOW WILL REMAIN PRIMARILY OUT OF THE NORTHWEST THROUGH THE
WEEKEND...KEEPING CONDITIONS MAINLY DRY WITH BELOW NORMAL
TEMPERATURES. ANOTHER S/WV TROUGH WILL PUSH SEWRD WITHIN THE MEAN
FLOW...AND DRAG A MUCH STRONGER COLD FRONT TOWARD THE TN VALLEY BY
SATURDAY NIGHT INTO SUNDAY. LATEST GFS SHOWING A BIT MORE MOISTURE
WITH THIS SYSTEM NOW...AND IS MUCH MORE AGGRESSIVE WITH THE STRENGTH
OF THE COLD SHOT TO FOLLOW THE FROPA SUNDAY AND MONDAY. WITH A BIT
MORE MOISTURE TO WORK WITH AND SOME INCREASE IN UVM/CONVERGENCE...
WILL INTRODUCE JUST A SLIGHT CHANCE OF PRECIP FOR SATURDAY NIGHT.
ASSUMING WE CAN SQUEEZE A LITTLE PRECIP OUT OF THIS SYSTEM...CHECK
OF PROGGED THERMAL PROFILES AND PARTIAL THICKNESS VALUES WOULD
INDICATE JUST A VERY COLD RAIN AT THIS POINT. THUS WILL KEEP THE
FORECAST ALL LIQUID FOR NOW...AND KEEP A CLOSE EYE ON LATER
MOISTURE/THERMAL TRENDS AS THE EVENT GETS CLOSER.

AS FOR TEMPERATURES...GFS LIKELY TRENDING IN THE RIGHT DIRECTION
WHEN PROJECTING ANOTHER DECENT COOLDOWN SUNDAY AND MONDAY...BUT
STILL SEEMS WAY TOO COLD...ESPECIALLY WHEN COMPARED TO THE LATEST
ENSEMBLES AND ECMWF (LOWS NEAR 10 MONDAY MORNING??). GIVEN THAT THE
GFS 'OVERFORECASTED' THE STRENGTH OF THE CURRENT COLD AIRMASS...NOT
QUITE READY TO BUY INTO THIS EXTREMELY COLD SOLUTION JUST YET.
NONETHELESS...DO EXPECT TEMPERATURES THROUGHOUT THE EXTENDED TO
REMAIN BELOW NORMAL...AND WILL BE TRENDING TEMPS FOR ALL PERIODS
FROM SUNDAY THROUGH TUESDAY GENERALLY 5-10 DEGREES COOLER.