mercredi 30 juillet 2014
European Storm Forecast Experiment
Storm Forecast
Storm Forecast
Valid: Thu 31 Jul 2014 06:00 to Fri 01 Aug 2014 06:00 UTC
Issued: Thu 31 Jul 2014 00:30
Forecaster: GATZEN
Valid: Thu 31 Jul 2014 06:00 to Fri 01 Aug 2014 06:00 UTC
Issued: Thu 31 Jul 2014 00:30
Forecaster: GATZEN
A level 2 was issued for parts of Finland mainly for severe wind gusts, tornadoes, and large hail.
A level 1 was issued for Finland and north-western Russia mainly for severe wind gusts, tornadoes, and large hail.
A level 1 was issued for Greece to Bulgaria and southern Romania mainly for large hail and excessive precipitation.
A level 1 was issued for the Baltic States, eastern Poland into Czech Rep, Slovakia, eastern Austria, Hungary, and the northern Balkans as well as the Alpine region mainly for excessive precipitation and to a lower extend large hail.
SYNOPSIS
A well-developed cut-off low moves slowly from the Adriatic Sea to the Balkan Peninsula. To its north, an intensifying ridge stretches from south-western Europe across central Europe to western Russia. A head of low geopotential over north-western Europe and the north-east Atlantic, several short-wave troughs move north-eastward.
At lower levels, a cold front has crossed Sweden and Germany and will affect a region from Finland to Poland and the northern Balkans on Thursday. Rich low-level moisture ahead of the front will allow for CAPE around 1000 J/kg in the afternoon hours. Rich moisture will also remain in the Alpine region, whereas drier air spreads into Germany and France.
Most storms will be weakly organized on Thursday, and main threat will be excessive precipitation given the moist profiles ahead of the cold front. Better storm organization due to stronger vertical wind shear can be expected in the vicinity of the cut-off low over Greece and Bulgaria as well as ahead of a short-wave trough entering Finland during the day.
A level 1 was issued for Finland and north-western Russia mainly for severe wind gusts, tornadoes, and large hail.
A level 1 was issued for Greece to Bulgaria and southern Romania mainly for large hail and excessive precipitation.
A level 1 was issued for the Baltic States, eastern Poland into Czech Rep, Slovakia, eastern Austria, Hungary, and the northern Balkans as well as the Alpine region mainly for excessive precipitation and to a lower extend large hail.
SYNOPSIS
A well-developed cut-off low moves slowly from the Adriatic Sea to the Balkan Peninsula. To its north, an intensifying ridge stretches from south-western Europe across central Europe to western Russia. A head of low geopotential over north-western Europe and the north-east Atlantic, several short-wave troughs move north-eastward.
At lower levels, a cold front has crossed Sweden and Germany and will affect a region from Finland to Poland and the northern Balkans on Thursday. Rich low-level moisture ahead of the front will allow for CAPE around 1000 J/kg in the afternoon hours. Rich moisture will also remain in the Alpine region, whereas drier air spreads into Germany and France.
Most storms will be weakly organized on Thursday, and main threat will be excessive precipitation given the moist profiles ahead of the cold front. Better storm organization due to stronger vertical wind shear can be expected in the vicinity of the cut-off low over Greece and Bulgaria as well as ahead of a short-wave trough entering Finland during the day.
European Storm Forecast Experiment
Storm Forecast
Storm Forecast
Valid: Wed 30 Jul 2014 06:00 to Thu 31 Jul 2014 06:00 UTC
Issued: Tue 29 Jul 2014 22:23
Forecaster: PUCIK
Valid: Wed 30 Jul 2014 06:00 to Thu 31 Jul 2014 06:00 UTC
Issued: Tue 29 Jul 2014 22:23
Forecaster: PUCIK
A level 2 was issued for E Adriatics coastline mainly for excessive precipitation and to the lesser extent for tornadoes, severe wind gusts and large hail.
A level 2 was issued for SE Austria, SW Hungary, N Croatia and N Serbia mainly for excessive precipitation, large hail and severe wind gusts.
A level 1 was issued for parts of Italy, Serbia, Balkans mainly for excessive precipitation and to the lesser extent for large hail and severe wind gusts.
A level 1 was issued for parts of Germany, Poland, Czech Republic, Slovakia, Austria and N Hungary mainly for excessive precipitation.
SYNOPSIS
Main macrosynoptic feature will remain in the form of a deep mid to upper tropospheric low moving from N Italy towards Balkans during the forecast period. It is expected to deccelerate and gradually fill out towards the Thursday morning. Scattered to widespread thunderstorms are expected ahead of the progressing low and along the wavy frontal boundary in the unstable airmass. Towards the north, geopotential fields will be rather weak, but still scattered thunderstorms are expected in moist airmass in the belt from N Germany and Poland towards Hungary. Some activity is also expected over Scandinavia with WAA regime ongoing on the forward flank of the low over the Norwegian Sea.
A level 2 was issued for SE Austria, SW Hungary, N Croatia and N Serbia mainly for excessive precipitation, large hail and severe wind gusts.
A level 1 was issued for parts of Italy, Serbia, Balkans mainly for excessive precipitation and to the lesser extent for large hail and severe wind gusts.
A level 1 was issued for parts of Germany, Poland, Czech Republic, Slovakia, Austria and N Hungary mainly for excessive precipitation.
SYNOPSIS
Main macrosynoptic feature will remain in the form of a deep mid to upper tropospheric low moving from N Italy towards Balkans during the forecast period. It is expected to deccelerate and gradually fill out towards the Thursday morning. Scattered to widespread thunderstorms are expected ahead of the progressing low and along the wavy frontal boundary in the unstable airmass. Towards the north, geopotential fields will be rather weak, but still scattered thunderstorms are expected in moist airmass in the belt from N Germany and Poland towards Hungary. Some activity is also expected over Scandinavia with WAA regime ongoing on the forward flank of the low over the Norwegian Sea.
lundi 28 juillet 2014
European Storm Forecast Experiment
Storm Forecast
Storm Forecast
Valid: Mon 28 Jul 2014 06:00 to Tue 29 Jul 2014 06:00 UTC
Issued: Sun 27 Jul 2014 21:53
Forecaster: GROENEMEIJER
Valid: Mon 28 Jul 2014 06:00 to Tue 29 Jul 2014 06:00 UTC
Issued: Sun 27 Jul 2014 21:53
Forecaster: GROENEMEIJER
A level 1 was issued for northeast Sweden and parts of Finland, mainly for heavy rain and to a lesser extent for large hail and severe wind gusts,
A level 1 was issued for parts of eastern France, for Belgium, the Netherlands, Luxembourg, Germany, and for north, west and south Poland, as well as for the Alpine countries, the Czech Republic, Slovakia parts of Hungary, northern Italy and the northwestern Balkans. It is issued mainly for heavy rain.
A level 1 was issued for cental and south Romania, eastern Serbia and NW Bulgaria.
A level 1 was issued for NE Spain, mainly for large hail.
SYNOPSIS
A broad trough covers most of western and central Europe. The air-mass is rather warm, humid and somewhat unstable. Within the through, a fairly strong cold-core mid-level cyclone located over the English Channel will move to south France by Tuesday morning. An embedded shotwave trough stretching from the eastern Alps across the western Balkans moves slowly eastward. Within a westerly flow across northern Europe, an embedded shortwave trough should reach the Norwegian coast by 00 UTC.
A level 1 was issued for parts of eastern France, for Belgium, the Netherlands, Luxembourg, Germany, and for north, west and south Poland, as well as for the Alpine countries, the Czech Republic, Slovakia parts of Hungary, northern Italy and the northwestern Balkans. It is issued mainly for heavy rain.
A level 1 was issued for cental and south Romania, eastern Serbia and NW Bulgaria.
A level 1 was issued for NE Spain, mainly for large hail.
SYNOPSIS
A broad trough covers most of western and central Europe. The air-mass is rather warm, humid and somewhat unstable. Within the through, a fairly strong cold-core mid-level cyclone located over the English Channel will move to south France by Tuesday morning. An embedded shotwave trough stretching from the eastern Alps across the western Balkans moves slowly eastward. Within a westerly flow across northern Europe, an embedded shortwave trough should reach the Norwegian coast by 00 UTC.
Jul 28, 2014 1630 UTC Day 1 Convective Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1121 AM CDT MON JUL 28 2014 VALID 281630Z - 291200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FROM THE COASTAL CAROLINAS TO THE N CENTRAL GULF COAST... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF NEW ENGLAND... ...SUMMARY... A FEW STRONG TO SEVERE STORMS CAPABLE OF PRODUCING DAMAGING WINDS WILL BE POSSIBLE THIS AFTERNOON AND EVENING FROM THE COASTAL CAROLINAS EXTENDING WEST SOUTHWESTWARD INTO THE NORTH CENTRAL GULF COAST STATES. ISOLATED STRONG TO SEVERE STORMS MAY ALSO OCCUR TODAY OVER PORTIONS OF NEW ENGLAND. ...EASTERN CAROLINAS INTO SOUTHERN MS/AL... A LARGE UPPER TROUGH HAS BECOME ESTABLISHED OVER THE EASTERN UNITED STATES...WITH THE MAIN COLD FRONT NOW EXTENDING FROM NC INTO THE GULF COAST STATES. AMPLE LOW LEVEL MOISTURE AND STRONG HEATING WILL YIELD A MODERATELY UNSTABLE AIR MASS AHEAD OF THE FRONT THIS AFTERNOON FROM EASTERN NC/SC INTO PARTS OF GA/AL/MS. THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG/AHEAD OF THE FRONT AND NEAR SEA BREEZE BOUNDARIES. FORECAST SOUNDINGS SHOW RATHER STRONG WINDS ALOFT FROM GA NORTHEASTWARD...WHERE ORGANIZED/SUPERCELL STORM STRUCTURES ARE POSSIBLE. THIS AREA IS MOST LIKELY TO SEE LOCALLY SEVERE STORMS CAPABLE OF DAMAGING WINDS AND HAIL. FARTHER WESTWARD...VERTICAL SHEAR PROFILES ARE WEAKER...BUT POTENTIAL WILL REMAIN FOR A ISOLATED SEVERE STORMS WITH DAMAGING WINDS THE MAIN THREAT. ...NEW ENGLAND... A COMPACT UPPER LOW IS MOVING NORTHEASTWARD ACROSS NY. A MID LEVEL DRY SLOT IS ROTATING AROUND THE EAST SIDE OF THE LOW...WHERE SOME DAYTIME HEATING AND STEEPENING LAPSE RATES WILL OCCUR THIS AFTERNOON. RESIDUAL DEWPOINTS IN THE 60S AND COOLING TEMPERATURES ALOFT WILL PROMOTE CAPE VALUES OF 500-1000 J/KG. FORECAST SOUNDINGS APPEAR FAVORABLE FOR A FEW STRONG/SEVERE STORMS CAPABLE OF LARGE HAIL AND DAMAGING WINDS. A BRIEF TORNADO CANNOT BE RULED OUT. THE THREAT SHOULD END RATHER QUICKLY AFTER SUNSET.
dimanche 27 juillet 2014
Current Mesoscale Discussions,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,http://www.spc.noaa.gov/products/md/
 | Mesoscale Discussion #1482 Issued: 27/1654 UTC Until: 27/1800 UTC Concerning: SEVERE POTENTIAL...WATCH POSSIBLE |
 | Mesoscale Discussion #1481 Issued: 27/1652 UTC Until: 27/1815 UTC Concerning: SEVERE POTENTIAL...WATCH POSSIBLE |
Jul 27, 2014 0600 UTC Day 1 Convective Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1257 AM CDT SUN JUL 27 2014 VALID 271200Z - 281200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING ACROSS PARTS OF SOUTHEASTERN OHIO AND EASTERN KENTUCKY INTO WESTERN/CENTRAL WEST VIRGINIA AND ADJACENT SOUTHWEST VIRGINIA... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MODERATE RISK AREA ACROSS MUCH OF THE OHIO VALLEY AND MID ATLANTIC COAST REGION INTO SOUTHERN NEW ENGLAND... ...SUMMARY... SEVERE THUNDERSTORMS ARE EXPECTED TODAY INTO TONIGHT ACROSS MUCH OF THE OHIO VALLEY AND MID ATLANTIC COAST REGION INTO PORTIONS OF SOUTHERN NEW ENGLAND. SWATHS OF POTENTIALLY DAMAGING WIND GUSTS AND LARGE HAIL ARE POSSIBLE...PARTICULARLY ACROSS PORTIONS OF THE MID OHIO VALLEY INTO CENTRAL APPALACHIANS...WHERE A COUPLE OF TORNADOES MAY ALSO NOT BE OUT OF THE QUESTION. ...SYNOPSIS... MUCH AS HAS BEEN INDICATE BY THE MODELS...AMPLIFICATION APPEARS UNDERWAY WITHIN THE LARGE-SCALE UPPER FLOW PATTERN. AS SUBTROPICAL RIDGING BUILDS NORTHWARD THROUGH THE NORTHERN INTERMOUNTAIN REGION AND ROCKIES...A CLOSED LOW...WHICH HAS BEEN UNDERCUTTING THE BLOCKING HIGH OVER NORTHERN CANADA...IS CURRENTLY TURNING SOUTHEAST OF THE INTERNATIONAL BORDER AREA INTO THE UPPER MIDWEST. THIS FEATURE IS FORECAST TO CONTINUE DIGGING ACROSS SOUTHWESTERN PORTIONS OF THE GREAT LAKES REGION TODAY...BEFORE TURNING EASTWARD TOWARD THE NORTHERN MID ATLANTIC COAST AND SOUTHERN NEW ENGLAND TONIGHT...TO THE SOUTH OF THE PERSISTENT EASTERN CANADIAN VORTEX. AS THIS OCCURS...SEASONABLY STRONG /50-70 KT/ CYCLONIC MID-LEVEL FLOW /700-500 MB/ IS EXPECTED TO NOSE SOUTHEASTWARD ACROSS THE OHIO VALLEY TOWARD THE MID ATLANTIC COAST REGION. AND AN INITIAL SIGNIFICANT COLD FRONT LIKELY WILL SURGE SOUTHEASTWARD THROUGH MUCH OF THE MIDDLE MISSISSIPPI AND OHIO/TENNESSEE VALLEYS BY 12Z MONDAY. WITH MOISTURE SEASONABLY HIGH BENEATH THE REMNANTS OF ELEVATED MIXED LAYER AIR STILL PRESENT ACROSS THE MIDDLE MISSISSIPPI VALLEY THROUGH A LARGE PORTION OF THE OHIO VALLEY...SUFFICIENT POTENTIAL INSTABILITY EXISTS TO SUPPORT WIDESPREAD THUNDERSTORM ACTIVITY TODAY. THIS WILL INCLUDE THE RISK FOR SEVERE STORMS...IN THE PRESENCE OF ANOMALOUSLY STRONG DEEP LAYER FLOW FIELDS AND SHEAR. OTHERWISE...LINGERING MONSOONAL MOISTURE ACROSS THE SOUTHERN PLATEAU/GREAT BASIN INTO THE CENTRAL AND SOUTHERN ROCKIES...AND EASTWARD ALONG A FRONTAL ZONE ADVANCING INTO THE SOUTH CENTRAL PLAINS...IS EXPECTED TO CONTRIBUTE TO CONSIDERABLE THUNDERSTORM ACTIVITY TODAY. ADDITIONAL SCATTERED THUNDERSTORM ACTIVITY IS PROBABLE IN THE CONTINUING PRESENCE OF HIGH MOISTURE CONTENT AIR NEAR CENTRAL AND SOUTHERN FLORIDA PENINSULA ATLANTIC COASTAL AREAS. ...OHIO VALLEY INTO MID ATLANTIC COAST/SOUTHERN NEW ENGLAND... CONVECTIVE DEVELOPMENT NOW SPREADING ACROSS THE CENTRAL APPALACHIANS REGION...AS WELL AS ADDITIONAL CONVECTIVE DEVELOPMENT WHICH STILL MAY OCCUR UPSTREAM OVER THE MIDDLE MISSISSIPPI VALLEY PRIOR TO DAYBREAK...PROVIDE UNCERTAINTY CONCERNING THE EXTENT AND MODE OF THE SEVERE WEATHER POTENTIAL FOR TODAY. THE WEAKENING LEAD CONVECTION APPEARS TO BE ASSOCIATED WITH AN IMPULSE THAT EMERGED FROM THE SOUTHWESTERN U.S. MONSOONAL REGIME. THIS FEATURE IS FORECAST TO SHIFT EAST OF THE CENTRAL APPALACHIANS INTO MID ATLANTIC COASTAL AREAS BY MIDDAY...WHERE ASSOCIATED FORCING MAY SUPPORT RENEWED STRONG/SEVERE STORM DEVELOPMENT IN THE PRESENCE OF A DESTABILIZING BOUNDARY LAYER. IN ITS WAKE...DEPENDING ON THE EVOLUTION OF UPSTREAM CONVECTION...IT APPEARS POSSIBLE THAT A TRAILING LOW-LEVEL BAROCLINIC ZONE ACROSS THE CENTRAL APPALACHIANS INTO THE MIDDLE OHIO VALLEY COULD BECOME A FOCUS FOR DISCRETE STORM DEVELOPMENT...AS THE MAIN UPSTREAM IMPULSE CONTINUES TO DIG ACROSS THE GREAT LAKES. IF THIS OCCURS...MOST GUIDANCE SUGGESTS THAT STRENGTHENING DEEP LAYER FLOW FIELDS AND SHEAR...INCLUDING SIZABLE CLOCKWISE CURVED LOW-LEVEL HODOGRAPHS...WILL BE SUPPORTIVE OF SUPERCELLS CAPABLE OF PRODUCING STRONG TORNADOES. CONFIDENCE REMAINS RELATIVELY LOW AT THE PRESENT TIME...BUT THE BOUNDARY WOULD SEEM TO FOCUS THE HIGHEST TORNADO PROBABILITIES ACROSS PARTS OF EASTERN KENTUCKY INTO WEST VIRGINIA. THE EVOLUTION OF A SIGNIFICANT PRE-FRONTAL SQUALL LINE ALSO DOES NOT APPEAR OUT OF THE QUESTION...AS STRONGEST MID/UPPER FORCING FOR UPWARD VERTICAL MOTION DEVELOPS SOUTHEASTWARD ACROSS THE MIDDLE OHIO VALLEY INTO THE CENTRAL APPALACHIANS BY EARLY THIS EVENING...BEFORE CONTINUING TOWARD THE MID ATLANTIC COAST OVERNIGHT. AGAIN THIS LARGELY DEPENDS ON THE CONVECTIVE EVOLUTION PRIOR TO MID AFTERNOON...WHICH STILL REMAINS UNCLEAR AT THE PRESENT TIME.
European Storm Forecast Experiment
Storm Forecast
Storm Forecast
Valid: Sun 27 Jul 2014 06:00 to Mon 28 Jul 2014 06:00 UTC
Issued: Sun 27 Jul 2014 06:28
Forecaster: VAN DER VELDE
Valid: Sun 27 Jul 2014 06:00 to Mon 28 Jul 2014 06:00 UTC
Issued: Sun 27 Jul 2014 06:28
Forecaster: VAN DER VELDE
A level 2 and a level 1 were issued for SE Italy, S Adriatic Sea, SW Balkan mainly for excessive convective precipitation, large hail, and tornadoes.
A level 1 was issued for S Germany and the northern Alpine region mainly for excessive convective precipitation.
A level 1 was issued for N Scandinavia mainly for large hail.
A level 1 was issued for N Catalonia mainly for large hail.
SYNOPSIS
Slight low pressure prevails from N Scandinavia into central Europe and Balkan, with steep lapse rates and sufficient moisture to create weakly capped MLCAPE of 500-1500 J/kg. Vertical shear and deep lifting will be weak or absent over a large part of this area. However, two upper/mid level lows are found on the map. One moves from Scotland toward northern France with the potential of destabilizing the Benelux, S UK and NW France at night. The other low moves from Italy into southern Balkan and is causing active thunderstorms over a large area and enhanced deep layer shear.
A level 1 was issued for S Germany and the northern Alpine region mainly for excessive convective precipitation.
A level 1 was issued for N Scandinavia mainly for large hail.
A level 1 was issued for N Catalonia mainly for large hail.
SYNOPSIS
Slight low pressure prevails from N Scandinavia into central Europe and Balkan, with steep lapse rates and sufficient moisture to create weakly capped MLCAPE of 500-1500 J/kg. Vertical shear and deep lifting will be weak or absent over a large part of this area. However, two upper/mid level lows are found on the map. One moves from Scotland toward northern France with the potential of destabilizing the Benelux, S UK and NW France at night. The other low moves from Italy into southern Balkan and is causing active thunderstorms over a large area and enhanced deep layer shear.
samedi 26 juillet 2014
Convective Outlooks
| Today's Outlook | |
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| This is tomorrow's forecast for organized severe thunderstorms over the contiguous United States. Please read the description of the risk categories for further information. The latest Day 2 Outlookis available as well as all Outlooks that have been issued today. | Tomorrow's Outlook |
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| This is the day after tomorrow's (day 3) forecast for organized severe thunderstorms over the contiguous United States. Please read the description of the risk categories for further information. The latest Day 3 Outlook is available as well as all Outlooks that have been issued today. | Day 3 Outlook |
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Jul 26, 2014 0600 UTC Day 1 Convective Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1257 AM CDT SAT JUL 26 2014 VALID 261200Z - 271200Z ...THERE IS A MDT RISK OF SVR TSTMS LATE THIS AFTERNOON INTO TONIGHT...MAINLY ACROSS MUCH OF CENTRAL ILLINOIS THROUGH CENTRAL AND SOUTHERN INDIANA...BUT THIS INCLUDES AT LEAST PARTS OF THE GREATER ST. LOUIS...INDIANAPOLIS...LOUISVILLE AND CINCINNATI METROPOLITAN AREAS... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MODERATE RISK AREA ACROSS MUCH OF THE MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS... ...SUMMARY... SEVERE STORMS...SOME ACCOMPANIED BY VERY LARGE HAIL...LOCALLY STRONG WIND GUSTS AND A COUPLE OF TORNADOES ARE EXPECTED TODAY INTO TONIGHT ACROSS PARTS OF THE MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS. ONE OR MORE ORGANIZED CONVECTIVE CLUSTERS CAPABLE OF GENERATING SWATHS OF POTENTIALLY DAMAGING WINDS MAY EVOLVE LATE THIS AFTERNOON AND EVENING ACROSS MUCH OF CENTRAL ILLINOIS INTO CENTRAL AND SOUTHERN INDIANA...PERHAPS REACHING THE CENTRAL APPALACHIANS BY LATE TONIGHT. ...SYNOPSIS... WHILE BLOCKING APPEARS LIKELY TO REMAIN PROMINENT WITHIN THE WESTERLIES ACROSS THE HIGHER LATITUDES OF NORTH AMERICA...MODELS INDICATE UPPER TROUGHING EITHER SIDE OF THE HIGH CENTER OVER INTERIOR NORTHERN CANADA WILL BEGIN TO UNDERGO AMPLIFICATION DURING THIS PERIOD. AS THIS OCCURS...SUBTROPICAL RIDGING IS EXPECTED TO BUILD NORTHWARD THROUGH MUCH OF THE NORTHERN INTERMOUNTAIN REGION AND ROCKIES...AND THE CLOSED LOW...NOW UNDERCUTTING THE CANADIAN HIGH...SHOULD DIG SOUTHEASTWARD ACROSS THE CENTRAL CANADIAN/U.S. BORDER AREA. CONSIDERABLE SPREAD LINGERS WITHIN THE VARIOUS MODEL ENSEMBLE OUTPUT CONCERNING THIS LATTER DEVELOPMENT...BUT THE 12Z ECMWF AND 21Z NCEP SREF ENSEMBLE MEANS SUGGEST THAT THE REMNANT UPPER LOW/TROUGH PROBABLY WILL NOT REACH THE UPPER MIDWEST UNTIL LATE THIS EVENING OR OVERNIGHT. WHILE THE MAIN TRANSITION TO STRENGTHENING AND INCREASINGLY CYCLONIC MID-LEVEL FLOW MAY NOT OCCUR UNTIL WELL AFTER DARK ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY...DEEP LAYER SHEAR WILL BE MORE THAN SUFFICIENT FOR ORGANIZED CONVECTIVE DEVELOPMENT AS WEAK MID-LEVEL HEIGHT FALLS COMMENCE WITHIN THE NORTHWEST FLOW REGIME PRECEDING IT. BENEATH A REMNANT PLUME OF VERY WARM AND CAPPING ELEVATED MIXED LAYER AIR ALONG THE SOUTHERN EDGE OF THE STRONGER NORTHWEST FLOW...LOW-LEVEL MOISTENING SHOULD CONTINUE ACROSS THE LOWER MISSOURI/MIDDLE MISSISSIPPI VALLEYS INTO THE OHIO VALLEY. THIS IS EXPECTED TO CONTRIBUTE TO STRONG DESTABILIZATION SUPPORTIVE OF INTENSE CONVECTIVE DEVELOPMENT AND THE FOCUS FOR THE PRIMARY SEVERE WEATHER POTENTIAL TODAY. WEST SOUTHWESTWARD ALONG AN INITIAL SURFACE FRONT ADVANCING SOUTHWARD INTO THE CENTRAL PLAINS...SEVERE WEATHER POTENTIAL APPEARS LOWER DUE TO STRONGER LINGERING MID-LEVEL INHIBITION AND WEAKER SHEAR. HOWEVER...ISOLATED STRONG/SEVERE STORM DEVELOPMENT MAY NOT BE OUT OF THE QUESTION NEAR OR SHORTLY AFTER PEAK HEATING. OTHERWISE...CONDITIONS MAY ALSO BECOME AT LEAST MARGINALLY SUFFICIENT FOR STRONG/SEVERE STORM DEVELOPMENT IN RESPONSE TO THE EVOLVING UPPER PATTERN...ACROSS PARTS OF THE UPPER GREAT LAKES REGION THIS AFTERNOON THROUGH TONIGHT...AND PERHAPS AS FAR EAST AS THE LOWER GREAT LAKES/UPPER OHIO VALLEY AND CENTRAL APPALACHIANS BY LATE TONIGHT. MEANWHILE...MONSOONAL MOISTURE ACROSS THE HIGHER TERRAIN OF THE SOUTHERN PLATEAU INTO CENTRAL AND SOUTHERN ROCKIES WILL AGAIN SUPPORT CONSIDERABLE THUNDERSTORM ACTIVITY TODAY AND TONIGHT. ...MIDDLE MISSISSIPPI INTO LOWER OHIO VALLEYS... CONVECTION ALLOWING MODEL GUIDANCE DOES NOT PROVIDE CLARITY FOR THIS FORECAST...OFFERING A RATHER BROAD RANGE OF POSSIBLE SOLUTIONS. HOWEVER...A FAIRLY CONSISTENT SIGNAL HAS BEEN EVIDENT IN THE NAM AND ECMWF...AMONG OTHER MODEL OUTPUT...SUGGESTING THAT POTENTIAL EXISTS FOR THE EVOLUTION OF ONE OR MORE ORGANIZED MESOSCALE CONVECTIVE SYSTEMS ACROSS PORTIONS OF THE MIDDLE MISSISSIPPI THROUGH LOWER OHIO VALLEYS DURING THIS PERIOD. GIVEN THE AFOREMENTIONED ENVIRONMENT CONDITIONS ANTICIPATED ACROSS THIS REGION BY LATE AFTERNOON...CONFIDENCE IS FAIRLY HIGH THAT A SIGNIFICANT SEVERE WEATHER EVENT WILL BE REALIZED. ALONG/NORTH AND NORTHEAST OF AN AXIS OF STRONG SURFACE HEATING ACROSS CENTRAL MISSOURI INTO CENTRAL ILLINOIS...MOISTENING BENEATH THE AXIS OF STEEPEST MID-LEVEL LAPSE RATES WILL CONTRIBUTE TO LARGE CAPE...BEFORE INHIBITION GRADUALLY ERODES. PROBABLY AIDED BY FORCING ASSOCIATED WITH LOWER/MID TROPOSPHERIC WARM ADVECTION...INITIATION OF STORMS MAY OCCUR PRIOR TO 21Z ACROSS PARTS OF SOUTHERN IOWA AND NORTHERN MISSOURI. INITIALLY DISCRETE...A FEW SUPERCELLS APPEAR POSSIBLE WITH THE POTENTIAL FOR VERY LARGE HAIL...PERHAPS TORNADOES...BEFORE ACTIVITY GRADUALLY CONSOLIDATES INTO AN ORGANIZING MESOSCALE CONVECTIVE SYSTEM AND DEVELOPS SOUTHEASTWARD ACROSS CENTRAL ILLINOIS AND CENTRAL/SOUTHERN INDIANA THROUGH THE EVENING. ALTHOUGH MORE UNCERTAIN...AS INITIAL ACTIVITY CONTINUES TO SPREAD TOWARD THE CENTRAL APPALACHIANS OVERNIGHT...FORCING ASSOCIATED WITH THE DIGGING UPSTREAM IMPULSE MAY SUPPORT RENEWED CONVECTIVE DEVELOPMENT ALONG THE TRAILING OUTFLOW BOUNDARY ACROSS THE MIDDLE MISSISSIPPI VALLEY. AT LEAST SOME GUIDANCE SUGGESTS THAT THIS COULD EVOLVE INTO ANOTHER SOUTHEASTWARD PROPAGATING MESOSCALE CONVECTIVE SYSTEM...IN AN ENVIRONMENT THAT SHOULD REMAIN CONDUCIVE TO THE PRODUCTION OF STRONG...POTENTIALLY DAMAGING WIND GUSTS.
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