VALID 04/1200Z-05/1200Z
THERE A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING AND TONIGHT... FOR PART OF SOUTHEAST LOUISIANA... SOUTHERN MISSISSIPPI... SOUTHERN ALABAMA. SEE MAP FOR DETAILS...
GENERAL THUNDERSTORMS ARE FORECAST THIS AFTERNOON AND THIS EVENING... FOR PARTS OF THE SOUTHERN AND CENTRAL ROCKIES ...SEE MAP FOR DETAILS...
GENERAL THUNDERSTORMS ARE FORECAST THIS AFTERNOON AND TONIGHT... FROM THE CENTRAL/SOUTHERN PLAINS EAST-SOUTHEAST INTO THE LOWER MS VALLEY AND SOUTHEAST...SEE MAP FOR DETAILS...
0Z UPPER AIR ANALYSIS REVEALS A LARGE UPPER LOW CENTERED FROM SOUTHEASTERN ONTARIO.. WESTWARD INTO THE UPPER MS VALLEY... A SECOND DEEPENING VIGOROUS UPPER LOW IS CENTERED ACROSS NORTHERN CA/NORTHWEST NV...
VAPOR CHANNEL IMAGERY INDICATES AFOREMENTIONED RAPIDLY DEEPENING UPPER LOW ACROSS NORTHERN CA/NORTHERN NV... STRONG DYNAMIC LIFT IS UNDER WAY WITHIN LEFT EXIT REGION -- FROM SOUTHERN/CENTRAL IDAHO SOUTH INTO MUCH OF UTAH.
VAPOR CHANNEL IMAGERY ALSO INDICATES PROMINANT SUBTROPICAL JET... FROM NORTHERN MEXICO ENE ACROSS MUCH OF TEXAS AND THE LOWER MS VALLEY...
...LOWER MISSISSIPPI VALLEY/SOUTHEAST...
SHORT-WV/SPEED MAX CURRENTLY ACROSS NORTHERN MEXICO IS FORECAST TO EJECT ENE INTO THE SOUTHEAST TX/SOUTHERN LA BY LATE AFTERNOON... WITH A SFC WARM FRONT CONTINUING ENE INTO PARTS OF SOUTHERN MS/AL OVERNIGHT. ENHANCED WAA SOUTH OF WARM FRONT IS PROGGED TO AID MID 60 DEW POINTS.. MODEST MID-LEVEL LAPSE RATES 6-6.5C/KM ATOP BOUNDARY LAYER WILL ALLOW FOR MLCAPE TO 1000J/KG.
MODELS INDICATES 40-50KNT SLY H85 LLJ... WITH 70+KNT H7 SPEED MAX. FORECAST SOUNDINGS AND DERIVED HODOGRAPHS REVEAL STRONG 0-3KM CURVATURE. THIS COMBINED WITH 0-1KM SHEAR 30-40KNTS SUGGEST THE THREAT FOR SUPERCELLS.
GIVEN LOW LEVEL HODOGRAPHS AND FORECAST PLACEMENT OF QUASI-STATIONARY/WARM FRONT INDICATE SUFFICIENT SHEAR WILL BE IN PLACE FOR SUSTAINED LOW LEVEL MESOCYCLONES... HOWEVER SOME QUESTION REMAINS WITH RESPECT TO THERMODYNAMIC ENVIRONMENT.
IF CONVECTION IS REALIZED... PRIMARY MODE WILL LIKELY BE SUPERCELLULAR INITIALLY... A TRANSITION TO MULTICELLULAR WITH EMBEDDED SUPERCELLS IS POSSIBLE. ISOLATED LARGE HAIL... DAMAGING WINDS AND ISOLATED TORNADOES ARE POSSIBLE.
...SOUTHERN/CENTRAL PLAINS...
AFOREMENTIONED SHRT-WV PROGGED ACROSS THE SOUTHEAST IS FORECAST TO TRAVERSE MUCH OF TEXAS... DEW POINTS IN THE MIDDLE 60'S COMBINED WITH STEEP MID-LEVEL LAPSE RATES WILL AID MLCAPE 1000-2000J/KG... GENERALLY ALONG AND SOUTH OF QUASI-STATIONARY FRONT. SCATTERED STRONG CONVECTION IS POSSIBLE... WITH ISOLATED SEVERE CONVECTION POSSIBLE INVOF FRONTAL BOUNDARY.
...CENTRAL/SOUTHERN ROCKIES...
AFOREMENTIONED VIGOROUS DEEPENING UPPER LOW ACROSS NORTHERN NV/NORTHERN CA IS FORECAST TO CONTINUE TO DEEPEN SLOWLY SOUTHEAST THROUGH THE DAY. COLD CORE UPPER LOW //H5 TEMPS -28 TO -32// ATOP DIADIABATIC HEATING WILL AID VERY STEEP LAPSE RATES 8-8.5C/KM. ALLOWING FOR CONDITIONAL INSTABILITY.. SUPPORTIVE OF CONVECTION CAPABLE OF PRODUCING HAIL... SOME ISOLATED LARGE HAIL.. AND ISOLATED DAMAGING WINDS IN STRONGEST CONVECTION.
- WARNER 10/04/09
NEXT UPDATE 10/06/09 0600UTC