|
Day 4-8 Convective Outlook Issued on Nov 26, 2010
Updated: Fri Nov 26 10:00:02 UTC 2010
| D4 | Mon, Nov 29, 2010 - Tue, Nov 30, 2010 |
D7 | Thu, Dec 02, 2010 - Fri, Dec 03, 2010 |
| D5 | Tue, Nov 30, 2010 - Wed, Dec 01, 2010 |
D8 | Fri, Dec 03, 2010 - Sat, Dec 04, 2010 |
| D6 | Wed, Dec 01, 2010 - Thu, Dec 02, 2010 |
(All days are valid from 12 UTC - 12 UTC) |
Note: A severe weather
area depicted in the Day 4-8 period indicates a 30% or higher probability
for severe thunderstorms within 25 miles of any point.
PREDICTABILITY TOO LOW is used to indicate severe storms may be
possible based on some model scenarios.
However, the location or occurrence of severe storms are in doubt
due to: 1) large differences in the deterministic model solutions,
2) large spread in the ensemble guidance, and/or
3) minimal run-to-run continuity.
POTENTIAL TOO LOW means the threat for a regional area of
organized severe storms appears highly unlikely during the entire
period (e.g. less than a 30% probability for a regional severe
storm area across the CONUS through the entire Day 4-8 period).
ZCZC SPCSWOD48 ALL
ACUS48 KWNS 260959
SPC AC 260959
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0359 AM CST FRI NOV 26 2010
VALID 291200Z - 041200Z
...DISCUSSION...
MEDIUM-RANGE MODELS ARE CONSISTENT THROUGH DAY 5...BOTH PROGRESSING
A LARGE MID-LEVEL TROUGH ACROSS THE CENTRAL AND ERN CONUS. AN
ASSOCIATED SURFACE COLD FRONT IS EXPECTED TO LIKEWISE SWEEP
EWD...CROSSING THE MS VALLEY DURING THE SECOND HALF OF DAY 4 /MON
11-29/ AND THEN REACHING THE VICINITY OF THE MIDDLE AND SRN ATLANTIC
COAST BY THE END OF DAY 5 /TUE 11-30/.
AS A RESULT OF A PRIOR/SUBSTANTIAL FRONTAL INTRUSION...QUALITY OF
GULF MOISTURE AVAILABLE FOR RETURN AHEAD OF THIS FRONTAL SYSTEM IS A
QUESTION. GFS FORECASTS UPPER 60S TO AROUND 70 DEWPOINTS INTO THE
GULF COASTAL REGIONS AHEAD OF THE FRONT DAY 4. AS A
RESULT...DESPITE WEAK LAPSE RATES ALOFT...MIXED-LAYER CAPE AROUND
500 J/KG IS INDICATED. THIS DEGREE OF CAPE COMBINED WITH FAVORABLY
STRONG/VEERING FLOW WITH HEIGHT WHICH WILL LIKELY ACCOMPANY THIS
SYSTEM WOULD SUPPORT AT LEAST SOME SEVERE/TORNADO POTENTIAL.
HOWEVER...ATTM QUESTIONS EXIST REGARDING THE ACTUAL QUALITY OF
BOUNDARY LAYER MOIST RETURN -- AND THUS CAPE DEVELOPMENT -- INTO
THIS AREA. GIVEN THIS...AND THE OVERALL DEGREE/COVERAGE OF SEVERE
THREAT WHICH WOULD EVOLVE EVEN IN THE CURRENT GFS
FORECAST...CONFIDENCE IS RELATIVELY LOW THAT A SUBSTANTIAL SEVERE
EVENT IS LIKELY. THUS...WILL NOT INTRODUCE A THREAT AREA ATTM BUT
EXPECT AT LEAST LOW SEVERE PROBABILITIES TO BE ADDED IN LATER
FORECASTS NEARER IN TIME TO THE ACTUAL EVENT.
..GOSS.. 11/26/2010
CLICK TO GET WUUS48 PTSD48 PRODUCT
|
|
weather.gov 
@NWSSPC
