RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Mon Sep 26 08:55:02 UTC 2016.
No Mesoscale Discussions are in effect as of Mon Sep 26 08:55:02 UTC 2016.
SPC 1200Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1244 AM CDT MON SEP 26 2016
VALID 261200Z - 271200Z
...THERE IS A MRGL RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER OH
VALLEY AND CNTRL APPALACHIAN MTNS...
...SUMMARY...
A FEW STRONG TO SEVERE THUNDERSTORMS MAY OCCUR THIS AFTERNOON ACROSS
PARTS OF THE UPPER OHIO RIVER VALLEY AND IN THE NEARBY APPALACHIANS.
...UPPER OH VALLEY...
AN UPPER-LEVEL LOW WILL MOVE ACROSS LAKE SUPERIOR TODAY AS AN
UPPER-LEVEL TROUGH EXTENDING SWD FROM THE LOW MOVES ACROSS THE WRN
GREAT LAKES REGION AND LOWER OH VALLEY. AT THE SFC...A COLD FRONT
WILL MOVE EWD ACROSS THE LOWER GREAT LAKES AND CNTRL APPALACHIANS
WITH AN AXIS OF INSTABILITY DEVELOPING JUST AHEAD OF THE FRONT. THE
STRONGEST INSTABILITY IS FORECAST TO DEVELOP ACROSS ERN KY AND WV
WHERE SFC DEWPOINTS SHOULD BE IN THE MID 60 S F. IN RESPONSE TO SFC
HEATING AND ENHANCED LOW-LEVEL CONVERGENCE...THUNDERSTORM
DEVELOPMENT WILL BE LIKELY ALONG THE FRONT DURING THE AFTERNOON. RAP
FORECAST SOUNDINGS NEAR THE INSTABILITY AXIS AT CHARLESTON WV FOR
21Z SHOW UNIDIRECTIONAL WIND PROFILES WITH 30 TO 40 KT OF FLOW IN
THE LOW TO MID-LEVELS. THIS COMBINED WITH A MOIST LAYER FROM THE SFC
TO 700 MB MAY BE ENOUGH FOR A COUPLE MARGINALLY SEVERE WIND GUSTS
WITH THE STRONGER MULTICELLS.
..BROYLES/COOK.. 09/26/2016
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SPC 0600Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT MON SEP 26 2016
VALID 271200Z - 281200Z
...NO SVR TSTM AREAS FORECAST...
...SUMMARY...
WHILE A FEW STRONG THUNDERSTORMS MAY OCCUR ACROSS THE CAROLINAS
AND/OR SOUTHERN ARIZONA TUESDAY...ORGANIZED SEVERE STORMS ARE NOT
CURRENTLY EXPECTED.
...MID-ATLANTIC/CAROLINAS/SOUTHEAST STATES...
THE CLOSED UPPER LOW OVER THE GREAT LAKES WILL GENERALLY SETTLE
SOUTH-SOUTHEASTWARD WITH WEAK HEIGHT FALLS/COOLING ALOFT OCCURRING
AS FAR SOUTH AS THE SOUTHERN APPALACHIANS AND CAROLINAS. AS THIS
OCCURS...A COLD FRONT WILL CONTINUE EASTWARD AND EXIT MUCH OF THE
NORTHEAST/MID-ATLANTIC SEABOARD TUESDAY...WHILE OTHERWISE SPREADING
SOUTHEASTWARD AND REACHING PARTS OF GA AND THE NORTHEAST GULF OF
MEXICO LATE TUESDAY NIGHT/EARLY WEDNESDAY.
NEAR AND AHEAD OF THIS COLD FRONT...IT STILL APPEARS THAT SUFFICIENT
DESTABILIZATION TUESDAY AFTERNOON COULD ALLOW FOR A FEW STRONGER
THUNDERSTORM UPDRAFTS/DOWNDRAFTS ACROSS SOUTHEAST VA AND THE
CAROLINAS AND POSSIBLY EAST GA...ALTHOUGH MID-LEVEL LAPSE RATES AND
DEEP-LAYER SHEAR WILL BE WEAK. A VERY LOCALIZED WIND-DAMAGE RISK
CANNOT BE ENTIRELY RULED OUT ACROSS THE REGION TUESDAY
AFTERNOON...BUT ORGANIZED SEVERE THUNDERSTORMS CURRENTLY APPEAR
UNLIKELY.
...SOUTHERN AZ...
INCREASING LOW-LEVEL MOISTURE IS EXPECTED ACROSS THE REGION ON THE
PERIPHERY OF THE NORTHWEST MEXICO/BAJA VICINITY UPPER LOW. WHILE
HEATING/BUOYANCY WILL NOT BE ROBUST...RELATIVELY COOL MID-LEVEL
TEMPERATURES AND MODEST VERTICAL SHEAR /AROUND 30 KT EFFECTIVE/
COULD SUPPORT SOME SEMI-SUSTAINED STRONGER STORMS CAPABLE OF HAIL
AND WIND. ALTHOUGH THE EXACT DEGREE OF DESTABILIZATION IS CURRENTLY
UNCERTAIN OWING TO THE POSSIBILITY OF RESIDUAL CLOUD COVER/EARLY-DAY
PRECIPITATION...THE REGION WILL BE REEXAMINED IN FUTURE OUTLOOKS FOR
THE POSSIBLE INCLUSION OF LOW SEVERE PROBABILITIES.
..GUYER.. 09/26/2016
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SPC 0730Z Day 3 Outlook
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0209 AM CDT MON SEP 26 2016
VALID 281200Z - 291200Z
...NO SVR TSTM AREAS FORECAST...
...SUMMARY...
WHILE ORGANIZED SEVERE THUNDERSTORMS ARE NOT CURRENTLY EXPECTED...A
FEW STRONGER STORMS COULD OCCUR ACROSS THE COASTAL SOUTHEAST ON
WEDNESDAY.
...CAROLINAS/SOUTHEAST STATES...
SOME GUIDANCE VARIABILITY EXISTS REGARDING THE EXACT
EVOLUTION/PLACEMENT OF THE PERSISTENT CLOSED LOW OVER THE GREAT
LAKES/MIDWEST ON WEDNESDAY...BUT IT SEEMS LIKELY TO CONTINUE
SETTLING SOUTH/SOUTHEASTWARD OVER THE OH/TN RIVER VALLEYS TOWARD THE
CENTRAL/SOUTHERN APPALACHIANS. THIS ALSO RELATES TO SOME UNCERTAINTY
REGARDING THE LOCATION/MOVEMENT OF A FRONT AS IT POTENTIALLY STALLS
ACROSS THE SOUTHEAST STATES/CAROLINAS AND NEAR-COASTAL MID-ATLANTIC.
GIVEN THAT A RELATIVELY MOIST PRE-FRONTAL AIR MASS MAY STILL BE
LOCATED AT LEAST ACROSS COASTAL PORTIONS OF THE CAROLINAS INTO EAST
GA/NORTH FL...AFTERNOON HEATING AND STRENGTHENING FORCING FOR
ASCENT/WINDS ALOFT COULD ACCOUNT FOR SOME STRONGER STORMS WEDNESDAY
AFTERNOON NEAR THE FRONT. WHILE THE AFOREMENTIONED FORECAST
UNCERTAINTIES CURRENTLY PRECLUDE SEVERE PROBABILITIES AT THE DAY 3
JUNCTURE...THIS WILL BE REEVALUATED IN FUTURE OUTLOOKS.
..GUYER.. 09/26/2016
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Day 4-8 Outlook
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0352 AM CDT MON SEP 26 2016
VALID 291200Z - 041200Z
...DISCUSSION...
THE OVERALL SEVERE POTENTIAL IS EXPECTED TO REMAIN RELATIVELY LOW
THROUGH LATE THIS WEEK. INITIALLY...WITH A SLOW-MOVING CLOSED LOW
PERSISTING OVER THE OH RIVER VALLEY/APPALACHIANS THROUGH AT LEAST
DAY 4/THURSDAY...THERE IS A SOME CHANCE THAT MEANINGFUL LOW-LEVEL
MOISTURE COULD PERSIST IN NEAR-COASTAL AREAS OF THE MID-ATLANTIC.
SHOULD THIS OCCUR...SOME STRONGER STORMS MAY BE POSSIBLE ON
THURSDAY...WHILE GENERALLY COOL/STABLE CONDITIONS WILL OTHERWISE
PREVAIL EAST OF THE ROCKIES THROUGH THE WEEKEND.
IN ADVANCE OF AN AMPLIFYING WESTERN STATES UPPER TROUGH LATE THIS
WEEK...THERE COULD BE A FEW STRONG STORMS ACROSS THE GREAT
BASIN/INTERMOUNTAIN WEST AS EARLY AS DAY 5/FRIDAY...AND INTO THE
NORTHERN ROCKIES AND NORTHERN HIGH PLAINS THIS WEEKEND. MEAGER
MOISTURE/BUOYANCY SHOULD BE CONSIDERABLE LIMITING FACTORS.
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SPC Day 1 Fire Weather Outlook
DAY 1 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0235 AM CDT MON SEP 26 2016
VALID 261200Z - 271200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN CALIFORNIA...
...SYNOPSIS...
A MID/UPPER-LEVEL REX PATTERN WILL BE ESTABLISHED ACROSS THE WEST
THROUGH THE PERIOD...AS A LOW SLOWLY DRIFTS NORTH NEAR BAJA
CALIFORNIA AND A RIDGE STAYS CENTERED OVER THE NORTHERN GREAT BASIN.
THIS PATTERN SHOULD MAINTAIN EAST/NORTHEASTERLY FLOW ALOFT OVER
SOUTHERN CALIFORNIA. ELSEWHERE...A CORRIDOR OF STRONG CYCLONIC FLOW
ALOFT WILL BE POSITIONED ACROSS THE GREAT LAKES REGION...WITH AN
EMBEDDED LOW NEAR LAKE SUPERIOR.
...PORTIONS OF SOUTHERN CALIFORNIA...
ANOTHER DAY OF CRITICAL FIRE-WEATHER CONCERNS IS EXPECTED
TODAY...WITH GUSTY WINDS AND LOW RH VALUES LIKELY ONGOING ACROSS
HIGHER ELEVATIONS/TERRAIN-FAVORED AREAS AT THE BEGINNING OF THE
PERIOD. THROUGH THE LATE MORNING HOURS...RH VALUES SHOULD QUICKLY
FALL INTO THE TEENS AND SINGLE DIGITS. MID/UPPER-LEVEL FLOW WILL BE
SOMEWHAT WEAKER THAN THAT OF THE PREVIOUS DAY...BUT IT SHOULD STILL
ENCOURAGE GUSTY OFFSHORE FLOW IN MANY LOCATIONS THROUGH THE LATE
MORNING AND EARLY AFTERNOON HOURS. MOREOVER...MORE EASTERLY
MID-LEVEL FLOW SUGGESTS THE STRONGEST WINDS WILL LIKELY EXIST ACROSS
THE HIGHER TERRAIN OF SAN DIEGO AND RIVERSIDE COUNTIES.
REGARDLESS...AREAS OF SUSTAINED WINDS AROUND 20-25 MPH /WITH GUSTS
OF 30-45 MPH/ ARE POSSIBLE THROUGH EARLY AFTERNOON...RESULTING IN
CRITICAL FIRE-WEATHER CONCERNS.
WINDS SHOULD DECREASE SOME LATER IN THE DAY...BEFORE NOCTURNAL
STRENGTHENING OF OFFSHORE FLOW OVERNIGHT. HOWEVER...RH RECOVERY
SHOULD BE GREATER VERSUS THAT OF THE PREVIOUS NIGHT...AS MID-LEVEL
MOISTURE INCREASES. THUS...WHILE SOME ELEVATED CONDITIONS ARE LIKELY
BY THE END OF THE PERIOD...CRITICAL CONDITIONS MAY BE LOCALIZED AT
BEST.
..PICCA.. 09/26/2016
...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...
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SPC Day 2 Fire Weather Outlook
DAY 2 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0236 AM CDT MON SEP 26 2016
VALID 271200Z - 281200Z
...SYNOPSIS...
A MID/UPPER-LEVEL LOW WILL CONTINUE DRIFTING NORTH FROM BAJA
CALIFORNIA TOWARDS SOUTHERN CALIFORNIA...WHILE RIDGING TO ITS NORTH
SHIFTS EASTWARD FROM THE GREAT BASIN TO THE CENTRAL ROCKIES. FARTHER
EAST...STRONG CYCLONIC FLOW ALOFT WILL REMAIN ESTABLISHED ACROSS THE
GREAT LAKES AND MID/UPPER MS VALLEY...AS A LOW DROPS SOUTH FROM LAKE
SUPERIOR TOWARDS IL.
...PORTIONS OF SOUTHERN CALIFORNIA...
WHILE FIRE-WEATHER CONCERNS WILL BE CONSIDERABLY LOWER THAN THOSE OF
THE PREVIOUS DAYS...ELEVATED CONDITIONS ARE STILL ANTICIPATED...
PRIMARILY DURING THE FIRST HALF OF THE PERIOD. A SOMEWHAT ENHANCED
SFC PRESSURE GRADIENT TUESDAY MORNING SHOULD PROMOTE SUSTAINED
EASTERLY WINDS AROUND 20-25 MPH /WITH HIGHER GUSTS/...ESPECIALLY
OVER THE HIGHER TERRAIN OF SAN DIEGO AND RIVERSIDE COUNTIES.
FOLLOWING SUNRISE...RH VALUES SHOULD FALL INTO THE TEENS AND
20S...WITH SOME BREEZINESS PERSISTING ACROSS SOUTHERN
CA...ESPECIALLY IN TERRAIN-FAVORED LOCATIONS. GIVEN THE PRESENCE OF
VERY DRY FUELS...FIRE-WEATHER CONCERNS WILL REMAIN ELEVATED.
HOWEVER...THESE CONCERNS SHOULD TREND DOWNWARD LATER IN THE DAY...AS
WINDS DECREASE THROUGH THE AFTERNOON...AND RH VALUES INCREASE
THROUGH THE EVENING AND OVERNIGHT HOURS WITH THE APPROACH OF A
MID-LEVEL LOW.
..PICCA.. 09/26/2016
...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...
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