Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS02 KWNS 021728
SWODY2
SPC AC 021727

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1127 AM CST MON MAR 02 2015

VALID 031200Z - 041200Z

...NO SVR TSTM AREAS FORECAST...

...SUMMARY...
ISOLATED THUNDERSTORMS ARE EXPECTED TUESDAY AFTERNOON ACROSS PARTS
OF THE FOUR CORNERS STATES...AND ON TUESDAY EVENING/NIGHT FROM THE
SOUTHERN GREAT PLAINS TO THE LOWER OHIO VALLEY.

...SYNOPSIS...
A BROAD MID-LEVEL TROUGH WILL GRADUALLY SHIFT EAST DURING THE PERIOD
BECOMING CENTERED FROM NORTHERN ONTARIO TO THE GULF OF CALIFORNIA BY
04/12Z. EMBEDDED WITHIN THIS TROUGH WILL BE SEVERAL SHORTWAVE
IMPULSES OF VARYING AMPLITUDE. A FLAT RIDGE WILL MOVE TOWARDS THE
EAST COAST...EMANATING FROM AN ANTICYCLONE CENTERED OVER THE WESTERN
CARIBBEAN. AT THE SURFACE...PRIMARY CYCLONE SHOULD BECOME
ESTABLISHED OVER NORTHERN ONTARIO WITH A PROGRESSIVE COLD FRONT
REACHING THE OHIO VALLEY TO SOUTHERN GREAT PLAINS TUESDAY NIGHT.

...ARK-LA-TEX TO LOWER OHIO VALLEY...
STRENGTHENING LOW-LEVEL SOUTH/SOUTHWESTERLIES LATE DAY 1 INTO DAY 2
WILL YIELD POLEWARD TRANSPORT OF A WESTERN GULF MOISTURE PLUME. THE
APPROACHING COLD FRONT WILL IMPINGE ON THIS MODIFYING WARM SECTOR
TUESDAY EVENING/NIGHT. HOWEVER...INSTABILITY WILL BE QUITE LIMITED
BY MID/UPPER-LEVEL WARM-AIR ADVECTION DOWNSTREAM OF THE BROAD
TROUGH. ONLY MEAGER MUCAPE IS EXPECTED WHERE FORCED ASCENT OCCURS
ALONG AND BEHIND THE FRONT. AN EXPANDING SHALLOW CONVECTIVE BAND
SHOULD DEVELOP BY TUESDAY EVENING. IT IS POSSIBLE THAT SPORADIC
LIGHTNING STRIKES MAY ACCOMPANY EMBEDDED DEEPER UPDRAFTS.

...FAR WEST TO NORTH TEXAS...
A LOBE OF FORCED ASCENT SHOULD OVERSPREAD THE REGION TUESDAY
EVENING/NIGHT AS MID-LEVEL HEIGHT FALLS OCCUR DOWNSTREAM OF THE
SOUTHERN-STREAM SHORTWAVE IMPULSE OVER THE GULF OF CALIFORNIA.
MOISTENING AROUND 700 MB AMIDST STEEPER MID-LEVEL LAPSE RATES
RELATIVE TO FARTHER NORTHEAST MAY YIELD SCANT BUOYANCY AND A RISK
FOR ISOLATED ELEVATED THUNDERSTORMS.

...FOUR CORNERS AREA...
DIURNAL HEATING NEAR THE MID-LEVEL THERMAL TROUGH WILL YIELD STEEP
TROPOSPHERIC LAPSE RATES. DESPITE LIMITED MOISTURE...AN EMBEDDED
SHORTWAVE IMPULSE TRACKING ACROSS THE EASTERN GREAT BASIN IN
CONJUNCTION WITH OROGRAPHIC ASCENT SHOULD FOSTER A RISK FOR ISOLATED
LIGHTNING TUESDAY AFTERNOON.

..GRAMS.. 03/02/2015



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