Saturday, March 29, 2014

DAY2SVR: Nws Storm Prediction Center Norman Ok

ACUS02 KWNS 291728
SWODY2
SPC AC 291727

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1227 PM CDT SAT MAR 29 2014

VALID 301200Z - 311200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
A QUASI-ZONAL SYNOPTIC FLOW REGIME WILL PERSIST D2...WITH A LOW
AMPLITUDE PACIFIC SHORTWAVE TROUGH /CURRENTLY LOCATED NEAR
35.5N/134W PER WATER VAPOR IMAGERY/ EXPECTED TO MOVE EWD ACROSS THE
GREAT BASIN TOWARD THE CENTRAL ROCKIES SUNDAY MORNING/AFTERNOON AND
INTO THE CENTRAL PLAINS SUNDAY NIGHT. THIS FEATURE WILL INDUCE LEE
CYCLOGENESIS OVER THE CENTRAL HIGH PLAINS DURING THE DAY WITH A
TRAILING PRE-FRONTAL TROUGH EXTENDING SWD INTO THE SRN HIGH PLAINS.
MEANWHILE...A COLD FRONT WILL MOVE SWD ACROSS SD AND MN...STALLING
FROM NRN NEB INTO SRN MN TO NWRN WI SUNDAY AFTERNOON. AS THE GREAT
BASIN SHORTWAVE TROUGH MOVES INTO THE CENTRAL PLAINS SUNDAY
NIGHT...THE LEE CYCLONE WILL TRACK ENEWD AND DEEPEN SOME ALONG THE
SWRN EXTENSION OF THE AFOREMENTIONED COLD FRONT REACHING CENTRAL OR
ERN NEB BY 12Z MONDAY. A COLD FRONT ATTENDANT TO THE SHORTWAVE
TROUGH WILL MOVE ACROSS UT AND THE FOUR CORNERS REGION SUNDAY...AND
THEN MERGE WITH THE LEE TROUGH SUNDAY NIGHT...ADVANCING EWD ACROSS
NEB...WRN KS AND INTO WEST TX.

...ERN UT/WRN CO/ADJACENT SRN WY...
THE COMBINATION OF MID-LEVEL ASCENT ATTENDING THE GREAT BASIN
SHORTWAVE TROUGH...A STEEP LAPSE RATE ENVIRONMENT...AND OROGRAPHIC
FORCING WILL LIKELY CONTRIBUTE TO A FEW HIGH-BASED TSTMS OVER THE
CENTRAL ROCKY MOUNTAIN REGION SUNDAY AFTERNOON. DEEP-LAYER WINDS
WILL INCREASE IN ASSOCIATION WITH THE PROGRESSIVE SHORTWAVE TROUGH
IN THE PRESENCE OF INVERTED-V PROFILES...ESPECIALLY OVER ERN UT AND
WRN CO. DOWNWARD MIXING OF THE HIGHER MOMENTUM AIR ALONG WITH
EVAPORATIVE COOLING WITHIN CONVECTIVE ELEMENTS MAY RESULT IN LOCALLY
STRONG TSTM WIND GUSTS INTO EARLY EVENING.

...CENTRAL PLAINS...
A PLUME OF STEEP MID LEVEL LAPSE RATES WILL SPREAD EWD ACROSS THE
PLAINS TOWARD THE MS VALLEY DURING D2. SLY MOISTURE RETURN ACROSS
THE SRN/CENTRAL PLAINS WILL BE WEAK...DUE TO A COLD FRONTAL
INTRUSION INTO THE GULF OF MEXICO TODAY. THIS FACTOR SHOULD INHIBIT
THE POTENTIAL FOR SURFACE BASED TSTM DEVELOPMENT LATER IN THE D2
PERIOD...GIVEN A STRONG CAP. HOWEVER...ELEVATED TSTMS WILL BE
POSSIBLE SUNDAY NIGHT AS FORCING FOR ASCENT SPREADS EWD WITHIN
ELEVATED INSTABILITY /MUCAPE OF A FEW HUNDRED J PER KG/ AND LOW
LEVEL WAA INCREASES ALONG A STRENGTHENING PLAINS SLY LLJ. FORECAST
SOUNDINGS SUGGEST THESE STORMS SHOULD BE ROOTED AROUND 700 MB.

..PETERS.. 03/29/2014

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