RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Sat Aug 2 06:02:01 UTC 2014.
No Mesoscale Discussions are in effect as of Sat Aug 2 06:02:01 UTC 2014.
SPC 1200Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1144 PM CDT FRI AUG 01 2014
VALID 021200Z - 031200Z
...NO SVR TSTM AREAS FORECAST...
...SUMMARY...
A FEW STRONG TO SEVERE STORMS WILL BE POSSIBLE FROM PORTIONS OF
CENTRAL AND NORTHEASTERN OREGON...EASTERN WASHINGTON...NORTHERN
IDAHO INTO WESTERN MONTANA. A FEW OF THESE STORMS MAY BECOME CAPABLE
OF PRODUCING ISOLATED STRONG WIND GUSTS AND HAIL.
...SYNOPSIS...
BLOCKING PATTERN WILL PERSIST SATURDAY WITH UPPER TROUGH IN PLACE
OVER THE EASTERN HALF OF THE U.S. AND AN UPSTREAM RIDGE DOMINATING
MUCH OF THE WEST. WEAK VORTICITY MAXIMA WILL MOVE ALONG THE NWRN
PERIPHERY OF THE UPPER RIDGE INTO THE PACIFIC NW. AN UPPER LOW NOW
OVER BAJA WILL MOVE NWD REACHING SRN CA SATURDAY NIGHT.
...PACIFIC NW THROUGH NRN ROCKIES AREA...
AN AXIS OF MODEST INSTABILITY /400-800 J/KG MLCAPE/ WILL LIKELY
DEVELOP GENERALLY EAST OF THE CASCADES ACROSS ERN OREGON AND WA AS
WELL AS FARTHER EAST ACROSS THE NRN ROCKIES. A BELT OF 25-35 KT
MID-UPPER FLOW WILL SPREAD THROUGH THIS REGION IN ASSOCIATION WITH A
SHORTWAVE TROUGH LIFTING NEWD ALONG NWRN PERIPHERY OF THE UPPER
RIDGE...BUT DEEP SHEAR WILL REMAIN GENERALLY AOB 30 KT.
DESTABILIZATION AND DEEP MIXING OF THE BOUNDARY LAYER ALONG WITH
OROGRAPHIC FORCING WILL RESULT IN THUNDERSTORM INITIATION DURING THE
AFTERNOON. INVERTED-V PROFILES AND STEEP LAPSE RATES WILL PROMOTE A
THREAT FOR MAINLY ISOLATED DOWNBURST WINDS THROUGH EARLY EVENING.
...ELSEWHERE...
SCATTERED STORMS WILL OCCUR FROM THE CNTRL THROUGH SRN ROCKIES INTO
THE INTERMOUNTAIN WEST. OTHER STORMS WILL DEVELOP FROM THE NRN
PLAINS ALONG A SEWD MOVING COLD FRONT AS WELL AS FARTHER EAST OVER
THE OH VALLEY AND MID-ATLANTIC REGION IN ASSOCIATION WITH IMPULSES
MOVING THROUGH THE UPPER LOW. IN ALL OF THESE AREAS THE
SHEAR-INSTABILITY PARAMETER SPACE WILL NOT BE SUFFICIENT FOR AN
ORGANIZED SEVERE THREAT...BUT ISOLATED INSTANCES OF STRONG WIND
GUSTS CANNOT BE RULED OUT.
..DIAL/GRAMS.. 08/02/2014
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SPC 0600Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1133 PM CDT FRI AUG 01 2014
VALID 031200Z - 041200Z
...NO SVR TSTM AREAS FORECAST...
...SUMMARY...
SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG A FRONT DURING
THE LATE AFTERNOON FROM SOUTHERN MINNESOTA TO EASTERN NEBRASKA.
SCATTERED ROBUST THUNDERSTORMS SHOULD ALSO DEVELOP ACROSS MUCH OF
THE SOUTHWESTERN U.S. GUSTY WINDS AND PERHAPS SOME HAIL MAY BE
NOTED WITH THESE STORMS.
...UPPER MS VALLEY TO MID MO VALLEY...
RIDGE-TOPPING SHORT-WAVE TROUGH WILL DIG SEWD ACROSS NWRN ONTARIO
INTO THE NRN GREAT LAKES BY 04/00Z. IN RESPONSE TO THIS
FEATURE...SFC ANTICYCLONE SHOULD BUILD SOUTH OF THE INTERNATIONAL
BORDER FORCING A FRONTAL ZONE THROUGH CNTRL MN...SWWD INTO NRN NEB
BY PEAK HEATING. APPRECIABLE LARGE SCALE FORCING SHOULD REMAIN
ACROSS CANADA BUT STRONG BOUNDARY LAYER HEATING IS EXPECTED ALONG
THE WIND SHIFT...ESPECIALLY ACROSS THE CNTRL PLAINS WHERE SFC
TEMPERATURES MAY WARM ABOVE 90F. CINH WILL WEAKEN SUFFICIENTLY FOR
CONVECTIVE DEVELOPMENT ALONG THE WIND SHIFT WITH READINGS ABOVE 90F.
WHILE LOW LEVEL WARM ADVECTION MAY INDUCE CONVECTION EARLY IN THE
PERIOD ACROSS THE MID MO VALLEY...STRONGEST TSTMS SHOULD OCCUR
DURING THE AFTERNOON/EARLY EVENING WITHIN A WEAK-MODESTLY SHEARED
PROFILE. ROBUST THUNDERSTORMS SHOULD EVOLVE WITHIN WARM ADVECTION
ZONE AND GUSTY WINDS/MARGINALLY SEVERE HAIL COULD ACCOMPANY THE
STRONGEST STORMS.
...SOUTHWESTERN U.S...
LOW LATITUDE DISTURBANCE OVER THE BAJA PENINSULA WILL DRIFT NWD TO
NEAR THE CA BORDER EARLY IN THE PERIOD...THEN ACROSS SRN CA BY
04/12Z. CIRCULATION WITH THIS FEATURE MAY STRENGTHEN A BIT INTO THE
DAY2 PERIOD WHICH SHOULD ALLOW MEAN SLY FLOW TO INCREASE ACROSS NWRN
MEXICO INTO AZ/LOWER CO RIVER VALLEY. TROPICAL SURGE INTO THIS
REGION SHOULD RESULT IN CONSIDERABLE AMOUNT OF CONVECTION. IF
SUFFICIENT HEATING DEVELOPS WITHIN THIS FLOW REGIME THEN GUSTY WINDS
APPEAR POSSIBLE WITH STRONGER STORMS.
..DARROW.. 08/02/2014
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