Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS02 KWNS 290532
SWODY2
SPC AC 290531

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1231 AM CDT SUN MAR 29 2015

VALID 301200Z - 311200Z

...NO SVR TSTM AREAS FORECAST...

...SUMMARY...
THUNDERSTORMS ARE POSSIBLE ACROSS PARTS OF THE SOUTHERN STATES
DURING THE PERIOD. A COUPLE OF STRONG STORMS ARE POSSIBLE IN THE
SOUTHEAST...MAINLY MONDAY AFTERNOON.

...SYNOPSIS...
AMPLIFIED SHORTWAVE TROUGH CENTERED OVER THE LOWER GREAT LAKES
WILL PROGRESS OFF THE NORTHEAST/NEW ENGLAND COAST MON NIGHT AS
AN UPSTREAM IMPULSE TRACKS FROM THE SRN PRAIRIE PROVINCES TOWARDS
THE UPPER GREAT LAKES. THIS WILL EFFECTIVELY MAINTAIN MID-LEVEL
W/NWLYS OVER THE S-CNTRL/SOUTHEAST STATES. A WEAK SRN-STREAM
SHORTWAVE IMPULSE OVER THE ERN PACIFIC SHOULD REACH BAJA CA SUR BY
EARLY TUE. AT THE SURFACE...A LARGELY W/E-ORIENTED COLD FRONT WILL
SAG SOUTH ACROSS THE SOUTHEAST BEFORE DECAYING MON NIGHT. TRAILING
PORTION OF THIS BOUNDARY WILL BE DIFFUSE BUT SHOULD SLOWLY ADVANCE N
AS A WEAK WARM FRONT OVER THE SRN GREAT PLAINS.

...SOUTHEAST...
GUIDANCE CONTINUES TO DIFFER WITH SPATIOTEMPORAL DETAILS OF THE
FRONT AND THE DEGREE OF MOISTURE RETURN AHEAD OF IT. WITH MEAN
MIXING RATIOS OF ONLY 3-6 G/KG SAMPLED IN CNTRL/ERN GULF COAST
29/00Z RAOBS...AND A MODIFIED CONTINENTAL POLAR AIR MASS STILL
PRESENT OVER MUCH OF THE GULF BASIN PER GOES PW IMAGERY...THE DRIER
SPECTRUM OF GUIDANCE APPEARS MORE BELIEVABLE GIVEN THE SHORT PERIOD
FOR FURTHER AIR MASS MODIFICATION.

DIABATIC SURFACE HEATING AHEAD OF THE FRONT IN CONJUNCTION WITH
MID-LEVEL NWLYS SHOULD YIELD MODERATELY STEEP TROPOSPHERIC LAPSE
RATES. ON THE FRINGE OF MODERATE DEEP-LAYER SHEAR...A RISK FOR
LOCALLY STRONG WINDS AND MARGINAL HAIL MAY DEVELOP. BUT WITH WEAK
FORCING FOR ASCENT ALONG WITH THE AFOREMENTIONED UNCERTAINTY
REGARDING FRONTAL PLACEMENT/BOUNDARY-LAYER MOISTURE...THIS RISK
APPEARS TOO LOW TO WARRANT SEVERE PROBABILITIES THIS OUTLOOK.

...RED RIVER OF THE SOUTH...
VAST DIFFERENCES EXIST WITHIN GUIDANCE OVER PLACEMENT OF THE DIFFUSE
FRONT AND DEGREE OF WARM SECTOR LOW-LEVEL MOISTURE. LOW-LEVEL WAA
WILL OCCUR MON NIGHT N OF THE BOUNDARY AMIDST MODEST S/SWLY FLOW.
700-MB WLYS MAY MAINTAIN SUFFICIENT EML CAPPING TO COMPLETELY
PRECLUDE TSTM DEVELOPMENT. IT IS POSSIBLE THAT A CORRIDOR OF
ELEVATED CONVECTION COULD FORM TOWARDS 12Z/TUE. GIVEN SUCH LOW
CONFIDENCE...WILL REFRAIN FROM INTRODUCING PROBABILITIES FOR SEVERE
HAIL.

..GRAMS.. 03/29/2015




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