Skip to content

Mar 12, 2014 1300 UTC Day 1 Convective Outlook

March 12, 2014

Mar 12, 2014 1300 UTC Day 1 Convective Outlook

day1otlk

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0745 AM CDT WED MAR 12 2014

VALID 121300Z – 131200Z

…THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FROM THE CENTRAL APPALACHIANS TO THE MID ATLANTIC…

…CENTRAL APPALACHIANS/MID ATLANTIC THROUGH THIS EVENING…
A CYCLONE IN SE INDIANA WILL TRANSLATE EWD ALONG A BAROCLINIC ZONE TO SE PA/NJ BY THIS EVENING…AND THEN ON TO THE GULF OF MAINE BY THE END OF THE PERIOD. THE CYCLONE WILL DEEPEN SUBSTANTIALLY IN RESPONSE TO AMPLIFICATION AND PHASING OF SHORTWAVE TROUGHS NOW OVER THE MIDDLE AND UPPER MS VALLEYS. SW OF THE LOW…A COLD FRONT WILL MOVE EWD TO THE CREST OF THE APPALACHIANS BY EARLY AFTERNOON AND OFF THE MID/SE ATLANTIC COAST BY EARLY TONIGHT. THIS COLD FRONT WILL BE THE PRIMARY FOCUS FOR STRONG/SEVERE THUNDERSTORM DEVELOPMENT THROUGH THIS EVENING.

LOW-MIDLEVEL SWLY FLOW WILL STRENGTHEN THROUGH THE DAY FROM THE OH VALLEY/APPALACHIANS TO THE MID ATLANTIC BY THIS AFTERNOON AS A RESULT OF THE DEEPENING CYCLONE…WITH FORECAST WARM SECTOR HODOGRAPHS FAVORABLE FOR BOTH SUPERCELLS AND PERSISTENT BOWING SEGMENTS. HOWEVER…BUOYANCY WILL LIKELY REMAIN LIMITED IN THE WARM SECTOR DUE TO MOISTURE RETURN INTERRUPTED BY THE SRN STREAM TROUGH NOW OVER GA/N FL…AND A PREPONDERANCE OF CLOUDS/RAIN DURING THE DAY ACROSS THE MID ATLANTIC. AN INITIAL CORRIDOR OF MID 50S BOUNDARY LAYER DEWPOINTS WILL SPREAD NEWD FROM TN/KY TO THE W OF THE APPALACHIANS THIS MORNING…AND SIMILAR LOW-LEVEL MOISTURE WILL SPREAD NEWD FROM THE CAROLINAS TO VA/MD BY MID-LATE AFTERNOON IN ADVANCE OF THE COLD FRONT. SBCAPE WILL LIKELY PEAK FROM 100-500 J/KG…WITH THE LARGEST BUOYANCY EXPECTED WITHIN ANY CLOUD BREAKS.

FOCUSED LINEAR ASCENT ALONG THE FRONT AND DEEP-LAYER FLOW/SHEAR ORIENTED WITH LARGE COMPONENTS PARALLEL TO THE FRONT ALL SUGGEST THAT CONVECTION WILL ORGANIZE INTO A NARROW LINE/LINE SEGMENTS ALONG THE FRONT AND INTENSIFY SOME BY MIDDAY INTO THIS AFTERNOON. THOUGH BUOYANCY WILL REMAIN RELATIVELY WEAK…THE PRESENCE OF 50-60 KT LOW-LEVEL SWLY FLOW WILL CONTRIBUTE TO A RISK OF DAMAGING WINDS WITH DOWNWARD MOMENTUM TRANSFER IN THE FRONTAL CONVECTIVE LINE. ANY TORNADO RISK WILL DEPEND LARGELY ON DESTABILIZATION NEAR THE UPPER END OF EXPECTATIONS FOR THIS AFTERNOON.

…SC TO N FL TODAY…
A LEAD SRN STREAM SHORTWAVE TROUGH WILL ACCELERATE EWD FROM N FL/SE GA THE FIRST HALF OF THE DAY. IN ITS WAKE…WARMING MIDLEVEL TEMPERATURES AND ONLY MODEST INLAND MOISTURE RETURN WILL LIMIT THE DEPTH OF BUOYANCY AND THE PROSPECTS FOR DEEP CONVECTION/LIGHTNING WITH THE COLD FRONTAL PASSAGE THIS AFTERNOON/EVENING.

Advertisements

From → Weather Blog

Leave a Comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: