STORM2K

RL3AO wrote:The SPC didn't seem too bullish but we will see what they say in the next couple days.

THERE ARE QUITE A FEW GUIDANCE DIFFERENCES WITH INDIVIDUAL SYSTEMS
THAT OUR BLEND SEEMS TO ADDRESS BUT ONE OF THE MORE STARK
CONTRASTS IS THAT THE 06/12 UTC GFS AND 00/12 UTC CANADIAN AND 00
UTC NOGAPS...BUT NOT THE NEWER 12 UTC RUN...SEPARATE A MORE CLOSED
SRN POLAR CLOSED LOW SUN-WED FROM THE SWRN US SLOWLY EWD INTO THE
S-CENTRAL US. THERE ARE A FEW GFS AND ECMWF ENSEMBLE MEMBERS IN
THIS VEIN BUT OVERALL THIS SEEMS TO BE A LESS LIKELY ALTERNATE
SOLUTION CONSIDERING THE LACK OF A WELL DEFINED AND AMPLIFIED
UPSTREAM MID-UPPER LEVEL RIDGE. THE NEW 12 UTC ECMWF AND UKMET
ALSO STILL OFFER MORE PROGRESSIVE SOLUTIONS.

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0302 AM CST THU NOV 08 2007

VALID 111200Z - 161200Z

THE MEDIUM RANGE MODELS ARE IN BETTER AGREEMENT FOR THIS WEEKEND
SHOWING AN UPPER-LEVEL RIDGE OVER THE MS VALLEY. THIS RIDGE MOVES
EWD TO THE ATLANTIC COASTAL STATES WITH AN OPEN TROUGH DEVELOPING IN
THE ROCKIES BY EARLY NEXT WEEK. THE MODELS DIVERGE SHARPLY AT THIS
POINT WITH THE GFS MOVING A WELL-DEVELOPED UPPER-LEVEL TROUGH INTO
THE PLAINS STATES AND THE ECMWF REMAINING ZONAL ACROSS THE CNTRL AND
NRN STATES. THIS DIFFERENCE IN THE UPPER-LEVEL PATTERN PRESENTS A
LOT OF UNCERTAINTY CONCERNING THE SEVERE POTENTIAL. HOWEVER...IT
APPEARS LOW-LEVEL MOISTURE WILL BE ABLE TO RETURN NWD INTO THE
MID-MS VALLEY THIS WEEKEND. THIS WILL SET THE STAGE FOR THUNDERSTORM
ACTIVITY AS A COLD FRONT MOVES SEWD ACROSS THE CNTRL PLAINS AND
MID-MS VALLEY MONDAY AND TUESDAY AS DEPICTED BY THE ECMWF. IF ENOUGH
INSTABILITY DEVELOPS ALONG THE BOUNDARY...SEVERE THUNDERSTORMS WILL
BE POSSIBLE. HOWEVER...THE TIMING OF THE FRONT AND STRENGTH OF THE
UPPER-LEVEL TROUGH REMAIN HIGHLY UNCERTAIN AND A SEVERE WEATHER
THREAT AREA CAN NOT BE OUTLOOKED ATTM.

..BROYLES.. 11/08/2007

Ed Mahmoud wrote:Model differences still have SPC saying "Predictability Too Low" on 4-8 day outlook

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0302 AM CST THU NOV 08 2007

VALID 111200Z - 161200Z

THE MEDIUM RANGE MODELS ARE IN BETTER AGREEMENT FOR THIS WEEKEND
SHOWING AN UPPER-LEVEL RIDGE OVER THE MS VALLEY. THIS RIDGE MOVES
EWD TO THE ATLANTIC COASTAL STATES WITH AN OPEN TROUGH DEVELOPING IN
THE ROCKIES BY EARLY NEXT WEEK. THE MODELS DIVERGE SHARPLY AT THIS
POINT WITH THE GFS MOVING A WELL-DEVELOPED UPPER-LEVEL TROUGH INTO
THE PLAINS STATES AND THE ECMWF REMAINING ZONAL ACROSS THE CNTRL AND
NRN STATES. THIS DIFFERENCE IN THE UPPER-LEVEL PATTERN PRESENTS A
LOT OF UNCERTAINTY CONCERNING THE SEVERE POTENTIAL. HOWEVER...IT
APPEARS LOW-LEVEL MOISTURE WILL BE ABLE TO RETURN NWD INTO THE
MID-MS VALLEY THIS WEEKEND. THIS WILL SET THE STAGE FOR THUNDERSTORM
ACTIVITY AS A COLD FRONT MOVES SEWD ACROSS THE CNTRL PLAINS AND
MID-MS VALLEY MONDAY AND TUESDAY AS DEPICTED BY THE ECMWF. IF ENOUGH
INSTABILITY DEVELOPS ALONG THE BOUNDARY...SEVERE THUNDERSTORMS WILL
BE POSSIBLE. HOWEVER...THE TIMING OF THE FRONT AND STRENGTH OF THE
UPPER-LEVEL TROUGH REMAIN HIGHLY UNCERTAIN AND A SEVERE WEATHER
THREAT AREA CAN NOT BE OUTLOOKED ATTM.

..BROYLES.. 11/08/2007

Ed Mahmoud wrote:Latest Euro looks like GFS did a few days ago, while GFS continues to flip almost every run. If 12Z Euro pans out, might be an interesting Tuesday in TX & OK

THE MODELS SEEM TO BE
HAVING A DIFFICULT TIME INITIALIZING THE ALEUTIAN LOW AND STRONG
POLAR JET OVER THE PACIFIC NW. THE INITIALIZATION FOR THE 12Z
RUNS SEEMS TO BE BETTER TODAY. SHORT RANGE MODELS CONTINUE TO
BRING A STRONGER SHORTWAVE TROUGH INTO THE DESERT SW MONDAY AND
THEN INTO W TX ON TUESDAY. THE 12Z GFS AND CANADIAN MODELS SEEM
TO HAVE SOME GOOD AGREEMENT WITH THIS EVOLUTION. THE ECMWF SEEMS
TO DIG THE SHORTWAVE A LITTLE FARTHER SOUTH THAN THESE AND
RESULTS IN A MORE CUTOFF SYSTEM. THE GFS HAS TRENDED TO A MORE
PROGRESSIVE SOLUTION AS HAS THE CANADIAN. THE FORECAST HAS BEEN
TRENDED TOWARDS THESE SOLUTIONS ALTHOUGH HIGHER POPS MAY BE
POSSIBLE TUE/WED. THE GFS/CANADIAN TAKES THE POTENT SHORTWAVE
OVER MUCH OF TX TUE INTO WED WITH HEAVY RAINFALL AND SEVERE
WEATHER POSSIBLE. THE FORECAST WILL STICK WITH MAINLY 40 POPS FOR
NOW JUST IN CASE THE MODELS FLIP AGAIN ON THEIR SOLUTIONS. TUE
LOOKS TO BE THE BEST TIME FRAME FOR ORGANIZED THUNDERSTORM
ACTIVITY WHICH MAY COME TO AN END LATE WED. BOTH MODELS BRING A
STOUT COLD FRONT THROUGH THE AREA DURING THE DAY WED WHICH SHOULD
ALLOW FOR COOLER/MORE SEASONABLE TEMPS FOR THE END OF NEXT WEEK
IN THE EXTENDED FORECAST. FORECAST CONFIDENCE IS A LITTLE HIGHER
WITH SOME BETTER AGREEMENT AMONG THE MODELS. STILL...CONFIDENCE
IS NOT HIGH ENOUGH TO REALLY PUSH THE THREAT FOR SEVERE WEATHER.
IT DOES BEAR WATCHING AS PARTS OF TX COULD BE PRIMED FOR MORE
WIDESPREAD SEVERE WEATHER.

...DISCUSSION...
00Z ECMWF/GFS AND MOST MEMBERS OF THE LATEST NCEP-GEFS SUGGEST THAT
THE SRN STREAM UPR LOW THAT DROPS INTO NRN MEXICO EARLY NEXT WEEK
MAY NOT EJECT EWD INTO TX UNTIL AFTER FRIDAY 16 NOV. MEANWHILE...A
SERIES OF MID-LEVEL WAVES MOVING QUICKLY SEWD FROM THE N PAC BASIN
WILL GRADUALLY CARVE OUT A COLD...BUT PROGRESSIVE ERN STATES TROUGH
BY MID-LATE NEXT WEEK FOLLOWED BY MORE OF A ZONAL WNWLY FLOW PATTERN
BY THE WEEKEND. THIS SCENARIO WILL LIKELY SPELL A REINFORCEMENT OF
DRY/STABLE CONTINENTAL POLAR AIR THAT WILL SPREAD QUICKLY SEWD FROM
THE NRN PLAINS/GRTLKS REGION INTO FL AND THE NRN GULF BASIN BY
WEEK/S END. THOUGH A BAND OF SHOWERS/TSTMS WILL ACCOMPANY THE FRONT
ACROSS THE OH/TN VLYS...MID-SOUTH AND PARTS OF THE SRN PLAINS...POOR
MOISTURE/LAPSE RATE RECOVERIES AHEAD OF THE FRONT WILL PRECLUDE ANY
ORGANIZED SVR WEATHER OUTBREAKS.

..RACY.. 11/10/2007