Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 06/13/08

AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
847 PM PDT THU JUN 12 2008 .SYNOPSIS... HIGH PRESSURE OVER NORTHERN MEXICO WILL EXPAND INTO SOUTHERN CALIFORNIA THROUGH SATURDAY BRINGING WARMING TO INLAND AREAS AND A SHALLOWER MARINE LAYER. A WEAK TROUGH OF LOW PRESSURE ALONG THE WEST COAST NEXT WEEK WILL BRING SLIGHT COOLING AND SLIGHT DEEPENING OF THE MARINE LAYER. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... SATELLITE IMAGERY SHOWED LIMITED MARINE STRATUS AT SOME BEACHES THIS AFTERNOON AND EVENING...OTHERWISE CLEAR. THE 00Z MIRAMAR SOUNDING SHOWED A STRONG INVERSION BASED NEAR 2K FT. ONSHORE SURFACE PRESSURE GRADIENTS CONTINUED...BUT HAD WEAKENED SOME FROM YESTERDAY EVENING. NOT MUCH CHANGE FROM PREVIOUS THINKING WITH HIGH PRESSURE ALOFT OVER NW MEXICO EXPANDING OVER THE AREA THROUGH THE WEEKEND. WITH THE MARINE LAYER STILL AROUND 2K FT DEEP...THE STRATUS SHOULD DEVELOP AND EXTEND WELL INLAND ACROSS THE SAN DIEGO COUNTY VALLEYS TONIGHT AND INTO LOWER PORTIONS OF THE INLAND EMPIRE. EXPECT THE MARINE LAYER WILL THIN OVER THE NEXT COUPLE OF DAYS RESULTING IN WARMING FOR THE DESERTS...MOUNTAINS...AND INLAND VALLEYS AND LESS NIGHT AND MORNING LOW CLOUD/FOG PENETRATION INTO THE VALLEYS. CLOSE TO THE COAST...THE SEA BREEZE SHOULD HOLD DAYTIME TEMPS IN THE UPPER 60S AND 70S BUT HIGHS IN THE 90S AND 100S WILL BE COMMON FAR INLAND. A STRENGTHENING LOW-LEVEL INVERSION MAY KEEP SOME BEACHES CLOUDY...BUT MOST OF THE AREA WILL EXPERIENCE SUNNY DAYS THROUGH THE WEEKEND. LOOKING AHEAD TO NEXT WEEK...THE UPPER HIGH FLATTENS...ALLOWING A MORE WESTERLY FLOW TO DRIVE HEIGHTS/THICKNESS SLIGHTLY LOWER OVER SOCAL. THIS COUPLED WITH STRONGER ONSHORE FLOW WILL BRING SOME COOLING TO INLAND AREAS THROUGH THE WEEK. THE COOLING LOOKS MOST SIGNIFICANT TOWARD THE END OF THE WEEK. THE DRY AND STABLE FLOW PATTERN SHOULD PRECLUDE ANY CHANCE OF PRECIPITATION. && .AVIATION... 130300Z...ACARS SHOWS THAT THE MARINE LAYER IS AROUND 1900 FT. STRATUS HAS BEEN SLOW TO FORM SO FAR...BUT GIVEN THE ONSHORE FLOW AND LOW LEVEL MOISTURE PROFILE...THE STRATUS SHOULD DEVELOP IN COASTAL AREAS BETWEEN 04Z AND 06Z. BASES SHOULD GENERALLY BE AT OR SLIGHTLY ABOVE 1500 FT MSL WITH TOPS TO 2200 FT...WITH A SLIGHT DOWNWARD TREND OVERNIGHT. VALLEY COVERAGE OF STRATUS SHOULD BE A BIT LESS THAN LAST NIGHT. CLEARING WILL BE MODERATELY FAST FRI...BACK TO THE BEACHES BY 17Z. LOCAL BKN CONDITIONS DUE TO STRATUS WILL CONTINUE FRI AFTERNOON ALONG THE BEACHES. A SIMILAR ONSET TO THE STRATUS IS EXPECTED FRI NIGHT...BUT WITH CEILINGS CLOSER TO 1000 FT MSL. ABOVE THE MARINE LAYER...MOSTLY CLEAR SKIES AND UNRESTRICTED VISIBILITY THROUGH FRIDAY NIGHT. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC...JAD AVIATION/MARINE...MAXWELL NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
840 PM PDT THU JUN 12 2008 .UPDATE...MARINE LAYER DEVELOPING AS EXPECTED THIS EVENING. KNKX SOUNDING INDICATED MARINE LAYER INVERSION AROUND 2150 FT THIS AFTERNOON. THIS AGREES WELL WITH LATEST ACARS SOUNDING FROM KLGB WITH MARINE INVERSION AROUND 1950 FT...AND FROM KLAX WITH MARINE INVERSION NEAR 1400 FT. WEAK TROUGH OVER THE OFFSHORE WATERS WILL CONTINUE SOUTHEAST TO SOUTH FLOW OVER THE COASTAL WATERS. MARINE LAYER STRATUS WILL CONTINUE TO PUSH NORTH OVER THE NORTHERN COASTAL WATERS...AND THEN PUSH INTO CENTRAL COAST LATER TONIGHT. SOME CONCERN THAT MARINE LAYER MAY PUSH INTO THE SALINAS RIVER VALLEY TONIGHT...WITH KSNS-KPRB TRENDING ALMOST A FULL MILLIBAR UPVALLEY. HOWEVER WITH CEILINGS AT KSNS AT 300 TO 600 FEET...IT WILL BE A CLOSE CALL AT KPRB. SOUTH OF POINT CONCEPTION...THE COASTAL EDDY IN PLACE IS REFORMING...AND THEN THE MARINE LAYER WILL CONTINUE TO DEVELOP AND SURGE INTO THE COASTAL AREAS. WITH HEIGHTS AROUND 1400 FEET CURRENTLY...MARINE LAYER COVERAGE MAY PUSH FURTHER INTO THE VALLEYS TONIGHT THAN THE CURRENT PACKAGE INDICATES. PACKAGE INDICATES PATCHY COVERAGE LATER TONIGHT...BUT AREAS OF LOW CLOUDS AND FOG MAY END UP DEVELOPING. WITH ONLY MINOR CONCERNS...NO UPDATES WILL LIKELY BE ISSUED...UNLESS THE OBSERVATIONS INDICATE STRONGER SIGNALS FOR AN UPDATE. A WARMING TREND WILL OCCUR THROUGH THE WEEKEND...ESPECIALLY FOR THE VALLEY...MOUNTAIN...AND DESERT LOCALITIES. UPPER-LEVEL RIDGE WILL GRADUALLY BUILD THROUGH SATURDAY WITH SUBSIDENCE SQUASHING THE MARINE LAYER DEPTH. MARINE LAYER COVERAGE WILL DECREASE...DESPITE SURFACE GRADIENTS TRENDING MORE ONSHORE IN BOTH NAM-WRF SOLUTION. THIS WILL LIKELY KEEP THE COASTAL AREAS SOCKED IN...WITH THE IMMEDIATE COASTS CLEARING A LITTLE LATER ON FRIDAY...AND EVEN LESS CLEARING POTENTIAL ON SATURDAY. POSSIBLE CLEARING ISSUES MAY PERSIST INTO SUNDAY. AN INCREASING NORTHWEST FLOW WILL DEVELOP OVER THE OUTER WATERS ON SUNDAY EVENING...BRINGING A POSSIBLE COOLING TREND TO START THE WORK WEEK. THIS FLOW PATTERN SHOULD REINFORCE THE EDDY CIRCULATION ALLOWING THE MARINE LAYER TO DEEPEN. && .PREV DISCUSSION... /ISSUED 150 PM PDT THU JUN 12 2008/ SHORT TERM (TODAY-SUN)...LOW CLOUDS THAT WERE ALONG THE COAST THIS MORNING HAVE CLEARED OFF THE COAST FOR THE MOST PART EARLY THIS AFTERNOON. THERE WERE SOME LOW CLOUDS LINGERING IN A FEW ISOLATED LOCATIONS...OTHERWISE MOSTLY SUNNY SKIES WILL PREVAIL THRU EARLY EVENING. TEMPS THIS AFTERNOON WILL BE NEAR SEASONAL NORMS...EXCEPT SEVERAL DEGREES ABOVE NORMAL OVER INTERIOR SLO/SBA COUNTIES WITH READINGS CLIMBING WELL INTO THE 90S IN SOME AREAS. A BROAD LOW LEVEL SE TO S FLOW OVER THE NEARSHORE COASTAL WATERS ASSOCIATED WITH AN EDDY CIRCULATION CENTERED SE OF THE CHANNEL ISLANDS WILL BRING MORE LOW CLOUDS TO COASTAL AND SOME VALLEY AREAS TONIGHT. WITH THE MARINE LAYER EXPECTED TO LOWER SOME TONIGHT...THE EXTENT OF LOW CLOUDS INTO THE VALLEYS SHOULD BE LESS THAN LAST NIGHT. OTHERWISE...UPPER LEVEL RIDGING WILL BRING CLEAR SKIES TO MOST OF THE DISTRICT TONIGHT. UPPER RIDGING WILL LINGER OVER SOCAL FRI THRU SAT NIGHT...THEN A VERY WEAK UPPER TROF WILL MOVE OVER THE SWRN CA COAST ON SUN. DRY WEATHER WILL CONTINUE OVER THE FORECAST AREA THRU THE WEEKEND. WITH THE UPPER RIDGING OVER THE REGION...THE MARINE LAYER IS EXPECTED TO LOWER SOME...DOWN TO ABOUT 1000 FT OR LESS BY FRI NIGHT THEN REMAIN RATHER SHALLOW THRU SUN. GRADIENTS WILL BE GENERALLY VERY WEAK ONSHORE NIGHT AND MORNING HOURS...THEN A BIT STRONGER ONSHORE IN THE AFTERNOON...ESPECIALLY SAT AND SUN. IT LOOKS LIKE THE BROAD SE TO S FLOW OVER THE COASTAL WATERS WILL TURN MORE W AND NW OVER THE WEEKEND. WITH NO DEFINED EDDY AND THE SHALLOW MARINE LAYER...VARYING AMOUNTS OF NIGHT AND MORNING LOW CLOUDS AND FOG SHOULD AFFECT JUST THE COASTAL AREAS...ALTHO THE SBA S COAST SHOULD REMAIN CLEAR FRI AFTERNOON THRU SUN. TEMPS ARE EXPECTED TO BE SEVERAL DEGREES ABOVE NORMAL IN MOST AREAS AWAY FROM THE COAST THRU THE WEEKEND. THE WARMEST VALLEYS IN INTERIOR SLO/SBA COUNTIES ARE EXPECTED TO TOP OUT AROUND THE CENTURY MARK BOTH FRI AND SAT. LONG TERM (MON-THU)...RATHER BENIGN UPPER PATTERN THRU THE EXTENDED PERIOD. FLAT UPPER RIDGING WILL PREVAIL THRU TUE...WITH A BROAD W FLOW ALOFT OVER THE REGION. WEAK UPPER TROFFINESS SHOULD MOVE INTO THE AREA FOR WED AND THU. IT LOOKS LIKE THE MARINE LAYER REGIME WILL CONTINUE WITH SOME NIGHT AND MORNING LOW CLOUDS AND FOG MAINLY FOR COASTAL AREAS. OTHERWISE MOSTLY CLEAR SKIES WILL CONTINUE THRU THE PERIOD. TEMPS OVER THE REGION ARE EXPECTED TO RANGE FROM NEAR NORMAL ALONG THE COAST TO A FEW DEGREES ABOVE NORMAL INLAND. && .AVIATION...13/0345Z. VFR CONDITIONS STILL EXPECTED TO PERSIST AT KPRB...KPMD...AND KWJF. MVFR CEILINGS ARE EXPECTED TO PUSH INTO MOST AREAS WITH THE ONLY POSSIBILITY OF IFR CONDITIONS OCCURRING AT KSBP AND KSMX. KLAX...MVFR CEILINGS ARE SPREADING INTO KLAX AND VICINITY CURRENTLY. VFR CONDITIONS SHOULD REDEVELOP BETWEEN 15Z AND 17Z ON FRIDAY...BUT CLEARING COULD DELAY UNTIL 20Z. KBUR...VFR CONDITIONS SHOULD PERSIST THROUGH AT LEAST 08Z...WITH MVFR CEILINGS SPREADING INTO KBUR BETWEEN 08Z AND 10Z. VFR CONDITIONS SHOULD REDEVELOP AFTER 15Z ON FRIDAY. && .LOX WATCHES/WARNINGS/ADVISORIES... HIGH RIP CURRENT RISK (SEE LAXSRFLOX). && $$ PUBLIC...HALL/SIRARD AVIATION...HALL WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
120 PM PDT THU JUN 12 2008 .SYNOPSIS... HIGH PRESSURE OVER NORTHERN MEXICO WILL EXPAND INTO SOUTHERN CALIFORNIA THROUGH SATURDAY BRINGING WARMING TO INLAND AREAS AND A SHALLOWER MARINE LAYER. A WEAK TROUGH OF LOW PRESSURE ALONG THE WEST COAST NEXT WEEK WILL BRING SLIGHT COOLING AND SLIGHT DEEPENING OF THE MARINE LAYER. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM (TONIGHT THROUGH SUNDAY)... HIGH PRESSURE OVER NORTHERN MEXICO WILL EXPAND INTO SOUTHERN CALIFORNIA THROUGH SATURDAY...THEN WEAKEN SLIGHTLY SUNDAY. THIS WILL BRING WARMING TO INLAND AREAS THROUGH SATURDAY WITH SLIGHT COOLING SUNDAY. THERE MAY BE A MINOR INTRUSION OF MID LEVEL MOISTURE FROM THE SOUTHEAST ON SATURDAY BRINGING A FEW CLOUDS TO THE MOUNTAINS IN THE AFTERNOON. CURRENT AIRCRAFT SOUNDINGS SHOW A MARINE LAYER DEPTH OF 2000 TO 2500 FEET. THE INVERSION SHOULD GRADUALLY STRENGTHEN AND LOWER INTO SATURDAY. THE NAM SHOWS SUFFICIENT MARINE LAYER DEPTH FOR STRATUS TO EXTEND WELL INLAND ACROSS THE SAN DIEGO COUNTY VALLEYS TONIGHT AND INTO LOWER PORTIONS OF THE INLAND EMPIRE. STRATUS SHOULD NOT EXTEND QUITE AS FAR INLAND FOR THE WEEKEND...NO FARTHER THAN THE LOWER COASTAL VALLEYS. && .LONG TERM (MONDAY THROUGH THURSDAY)... A WEAK TROUGH OF LOW PRESSURE ALONG THE WEST COAST WILL BRING SEASONAL WEATHER WITH SLIGHT DEEPENING OF THE MARINE LAYER AND SLIGHTLY COOLER TEMPERATURES FOR INLAND AREAS. && .AVIATION... 122000Z...MARINE LAYER AROUND 2000 FT PER RECENT SOUNDINGS. THE MORNING STRATUS CLEARED OFF SIMILARLY TO WED...EXCEPT FOR SOME LINGERING AREAS STILL HUGGING THE IMMEDIATE COAST OF SAN DIEGO CO. EXPECT STRATUS TO BEGIN TO SPREAD BACK INTO COASTAL AIRPORTS FROM 00-04Z WITH BASES INITIALLY NEAR 1500 FT MSL. A LOWERING MARINE LAYER IS EXPECTED TONIGHT WITH BASES DROPPING SOMEWHAT AND STRATUS NOT REACHING AS FAR INLAND BY EARLY FRI. ON FRI...EARLY MORNING STRATUS OVER COASTAL SECTIONS AND WRN VALLEYS SHOULD CLEAR BACK TO THE COASTLINE AROUND 15-17Z. ABOVE THE MARINE LAYER...MOSTLY CLEAR SKIES AND UNRESTRICTED VISIBILITIES WILL PREVAIL TODAY THROUGH FRIDAY. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC...MARTIN AVIATION/MARINE...LAVIS NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1027 PM EDT THU JUN 12 2008 .UPDATE... WHILE THE STORMS TO OUR WEST AND NORTH ARE EXPECTED TO REMAIN THERE, OUTSIDE OF SOME DECAYING ACTIVITY LATE TONIGHT IN THE SAGINAW VALLEY, WE STILL EXPECT A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGHOUT OUR AREA DURING THE OVERNIGHT HOURS. THIS REMAINS THE CASE AS WARM AND HUMID AIR CONTINUES TO MAKE PROGRESS INTO SE MICHIGAN FROM INDIANA AND OHIO. THE 00Z DTX SOUNDING TELLS THE STORY AS IT SHOWS MODEST LOW LEVEL MOISTURE BELOW 800 MB WITH DRY AIR ABOVE. THIS DRY AIR INDICATES SOME POTENTIAL FOR COOLING DURING THE OVERNIGHT AND FURTHER DESTABILIZATION AS LOW LEVEL MOISTURE INCREASES ON INCREASING SOUTH FLOW. OUR GOING FORECAST HAS THIS HANDLED WELL WITH THE HIGHEST CHANCE OF RAIN OVERNIGHT IN THE SAGINAW VALLEY, TO ACCOUNT FOR ANY STORM REMNANTS FROM OUT WEST, AND LOWER CHANCES NEAR THE OHIO BORDER WHERE DEVELOPMENT OVERHEAD WILL HAVE LESS COVERAGE. && .PREV DISCUSSION...ISSUED 713 PM EDT THU JUN 12 2008 AVIATION... VFR WILL REMAIN IN EFFECT FOR MOST OF TONIGHT. THERE IS SOME CONCERN FOR A BRIEF PERIOD OF MVFR VISIBILITY IN FOG/HAZE AROUND SUNRISE BUT A BETTER CHANCE OF MVFR CONDITIONS WILL ARRIVE FRIDAY AFTERNOON WITH PROSPECTS OF HEAVIER SHOWERS AND THUNDERSTORMS. FOR THE REST OF THIS EVENING AND EARLY IN THE OVERNIGHT HOURS, EXPECT THE STORMS OVER WISCONSIN AND ILLINOIS TO STAY WEST OF OUR AREA, BUT AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE AS WARM AND HUMID AIR RETURNS TO THE AREA. A SITUATION MORE LIKE THAT IN CENTRAL OHIO AT PRESS TIME WOULD BE THE CASE HERE LATER ON, HOWEVER COVERAGE WILL BE TOO LOW TO INCLUDE AT ANY OF THE AIRPORTS. AS FOR FOG LATER IN THE NIGHT, SURFACE ANALYSIS AND MODEL FORECASTS INDICATE TOO MUCH GRADIENT FLOW FOR MUCH OF AN OBSTRUCTION BUT SOME LIGHT HAZE SHOULD BE EXPECTED AS SURFACE DEWPOINT APPROACHES 70F. THESE EXPECTATIONS MAY CHANGE MORE IN FAVOR OF FOG DEPENDING ON HOW THE WIND FIELD SHAPES UP DURING THE NIGHT. PREV DISCUSSION...ISSUED 411 PM EDT THU JUN 12 2008 SHORT TERM...TONIGHT SURFACE WARM FRONT POSITIONED FROM A CHICAGO TO FINDLEY LINE WITH SOUTHEASTERLY BACKED FLOW...COMBINED WITH PLENTY OF HIGH CLOUD DEBRIS...KEEPING TEMPERATURES NEAR 80 IN MOST AREAS AS OF 3PM. WILL EXPECT INLAND AREAS FROM ADRIAN TO OWOSSO TO SEE A FEW MORE DEGREE CLIMB THIS EVENING AS WINDS BEGIN TO BACK TO THE SOUTH LATE...WHILE LOCATIONS CLOSER TO LAKE HURON WILL STRUGGLE TO CLIMB ABOVE 80. THE HIGHER DEWPOINTS HAVE ALSO BEEN SLOW TO ARRIVE... FINALLY CREEPING INTO THE MID 60S IN THE FAR SOUTH. AN 18Z TAMDAR SOUNDING OUT OF DTW SHOWS MOISTURE STARTING TO INCREASE ABOVE 800MB BUT ALSO SHOWS A CAP IN PLACE NEAR 925MB. WE WILL NEED TO SEE TEMPS/DEWPOINTS APPROACH 85/67 TO BREAK THROUGH THIS CAP FOR AN ISOLATED THUNDERSTORM THIS EVENING...WHICH ADRIAN IS APPROACHING. HAVE REMOVED THE ISOLATED THUNDERSTORMS WORDING IN THE NORTHERN AREAS BUT WILL CONTINUE TO CARRY AN ISOLATED THUNDERSTORMS FROM DETROIT SOUTH TO THE OHIO BORDER WHERE SURFACE BASED CAPES ARE AROUND 1500 J/KG. SPC MESO-ANALYSIS SHOWS ENHANCED 850MB MOISTURE OVER OHIO ALSO TRYING TO PUSH NORTH INTO THIS AREA WITH WEAK LOW LEVEL CONVERGENCE ALSO IN PLACE. UPSTREAM SHOWERS AND THUNDERSTORMS DEVELOPING OVER ILLINOIS/WISCONSIN WILL CONTINUE TO TRACK NORTHEAST TOWARDS THE UPPER PENINSULA AS UPPER TROUGH OVER THE PLAINS PUSHES EASTWARD WITH DEEP SOUTH SOUTHWESTERLY FLOW. ADDITIONAL AND POTENTIALLY STRONG THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER ILLINOIS AND TRACK INTO WESTERN LOWER OVERNIGHT AS 45+ KNOT LOW LEVEL JET NOSES INTO THIS AREA. WILL EXPECT THIS ACTIVITY TO BE WEAKENING AS IT APPROACHES THE TRI-CITIES LATE TONIGHT REACHING THE WARMER MID-LEVELS UNDERNEATH THE STRONG UPPER RIDGE. HOWEVER IF THIS CONVECTION CAN REMAIN ORGANIZED...AN ISOLATED SEVERE STORM IS NOT OUT OF THE QUESTION. WILL INCREASE POPS TO 60 PERCENT IN THIS AREA AFTER 6 AM WHILE JUST CARRYING A CHANCE OF SHOWERS AND THUNDERSTORMS AFTER MIDNIGHT ELSEWHERE. LONG TERM...FRIDAY THROUGH THURSDAY FRIDAY/FRIDAY NIGHT IS SHAPING UP TO BE AN INTERESTING TIME FRAME AS A 100+ KNOT JET LIFTS NORTH/NORTHEAST UP THE FRONT SIDE OF THE LARGE UPPER TROUGH OVER THE CENTRAL NOAM INTO THE UPPER MIDWEST/WESTERN GREAT LAKES. BY LATE IN THE DAY...LIFT WITHIN THE RIGHT ENTRANCE REGION OF THIS JET WILL BE SPREADING EAST INTO LAKE MICHIGAN/WESTERN LOWER MICHIGAN ON SOUTH INTO ILLINOIS/INDIANA. WITH THIS UPPER LEVEL SUPPORT...WOULD EXPECT SHOWERS/THUNDERSTORMS TO ERUPT FROM SOUTHWEST LOWER MICHIGAN INTO ILLINOIS/INDIANA AND THEN SPREAD NORTHEAST INTO THE AREA DURING THE LATE AFTERNOON/EVENING HOURS AS THE ASSOCIATED SURFACE FRONTAL BOUNDARY PUSHES INTO THE REGION. THIS PART OF THE SCENARIO...TIMING THE LARGE SCALE LIFT/FORCING...IS THE EASY PART. THE COMPLICATING FACTOR FOR THIS FORECAST WILL BE ANY RESIDUAL ACTIVITY FROM OVERNIGHT SHOWERS/THUNDERSTORMS THAT PERSISTS INTO THE MORNING HOURS...AND WHAT THIS MAY DO TO LIMIT INSTABILITY. AS IT IS...WOULD EXPECT THE AIRMASS THAT ADVECTS INTO THE REGION ON STRENGTHENING SOUTH/SOUTHWEST FLOW TO SUPPORT MLCAPES NEAR 2000 J/KG SO LONG AS EXTENSIVE CONVECTIVE DEBRIS DOES NOT LINGER INTO THE MID AFTERNOON. WITH MID LEVEL FLOW IN THE 40-50 KNOT RANGE...SOME STORMS WILL LIKELY BECOME SEVERE...AND GIVEN ONLY SLIGHT DIRECTIONAL CHANGE IN THE SOUTHWESTERLY WIND FIELD...THE MAIN HAZARD WOULD BE DAMAGING WINDS. AT A MINIMUM...WILL BE LEAVING LIKELY POPS (60-70%) IN THE FORECAST FOR THE AREA...AND WILL MOST LIKELY PROBABLY ATTEMPT TO DEFINE AN AREA OF EVEN GREATER CHANCE (80%)...AS THE CHANCE OF RAIN SEEMS QUITE GOOD. WILL JUST HAVE TO MONITOR OVERNIGHT CONVECTION TO BETTER ASSESS SEVERE POTENTIAL. THIS WHOLE SYSTEM WILL THEN PROGRESS TO THE EAST OVERNIGHT FRIDAY NIGHT...WITH DRY WEATHER EXPECTED ON SATURDAY/SATURDAY NIGHT AS A RIDGE OF HIGH PRESSURE BUILDS EAST THROUGH THE AREA. DURING THIS TIME FRAME...THE CENTRAL NOAM UPPER TROUGH BECOMES CENTERED OVER CANADA WITH A BROAD...NEARLY ZONAL FLOW OVER THE NORTHERN TIER OF STATES. SEVERAL DISTURBANCES WILL PROGRESS THROUGH THE AREA WITHIN THIS FLOW REGIME...MAINLY IN THE SUNDAY/SUNDAY NIGHT TIME FRAME. THIS WILL BRING ANOTHER CHANCE OF SHOWERS/THUNDERSTORMS...WHICH COULD LINGER INTO MONDAY. DID ADJUST THE FORECAST SLIGHTLY FOR TIMING...BUT KEPT POPS GOING IN THIS TIME FRAME. AFTER THESE DISTURBANCES PROGRESS OFF TO THE EAST...THE UPPER TROUGH WILL RECENTER OVER THE EASTERN CONUS...WITH NORTHWEST FLOW BECOMING ESTABLISHED. A LARGE HIGH PRESSURE SETTLES INTO THE CENTRAL PART OF THE NATION...BRINGING QUIET WEATHER FOR THE REST OF THE FORECAST. TEMPERATURES WILL ALSO BE COOLER WITH HIGHS IN THE UPPER 60S TO 70S AND LOWS GENERALLY IN THE 50S. HUMIDITY LEVELS WILL ALSO BE RATHER PLEASANT AS THE FLOW OUT OF CANADA PERSIST INTO LATE NEXT WEEK. MARINE... A PREDOMINANT SOUTHEAST WIND WILL CONTINUE ACROSS ALL MARINE AREAS INTO THIS EVENING...WITH GUSTS OF 20 TO 25 KNOTS ON LAKE HURON. THIS PERSISTENT ONSHORE FLOW WILL RESULT IN HIGHER WAVES AND AN INCREASED THREAT OF RIP CURRENTS TONIGHT...BEFORE THE FLOW BECOMES SOUTH LATE TONIGHT INTO FRIDAY. WILL LEAVE CURRENT HEADLINES THIS EVENING AND OVERNIGHT IN PLACE FOR LAKE HURON...BUT CANCEL THEM OVER LAKE ST CLAIR AND WESTERN LAKE ERIE WHERE WINDS ARE STARTING TO SUBSIDE AS WE STABILIZE. ALTHOUGH THERE WILL BE A CHANCE OF THUNDERSTORMS TONIGHT...A GREATER THREAT FOR STORMS EXISTS ON FRIDAY INTO FRIDAY NIGHT AS A COLD FRONT SWEEPS ACROSS LOWER MICHIGAN. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON... SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT HURON...UNTIL 6 AM FRIDAY. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ UPDATE.......BT AVIATION.....BT SHORT TERM...KEC LONG TERM....DG MARINE.......DG YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
713 PM EDT THU JUN 12 2008 .AVIATION... VFR WILL REMAIN IN EFFECT FOR MOST OF TONIGHT. THERE IS SOME CONCERN FOR A BRIEF PERIOD OF MVFR VISIBILITY IN FOG/HAZE AROUND SUNRISE BUT A BETTER CHANCE OF MVFR CONDITIONS WILL ARRIVE FRIDAY AFTERNOON WITH PROSPECTS OF HEAVIER SHOWERS AND THUNDERSTORMS. FOR THE REST OF THIS EVENING AND EARLY IN THE OVERNIGHT HOURS, EXPECT THE STORMS OVER WISCONSIN AND ILLINOIS TO STAY WEST OF OUR AREA, BUT AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE AS WARM AND HUMID AIR RETURNS TO THE AREA. A SITUATION MORE LIKE THAT IN CENTRAL OHIO AT PRESS TIME WOULD BE THE CASE HERE LATER ON, HOWEVER COVERAGE WILL BE TOO LOW TO INCLUDE AT ANY OF THE AIRPORTS. AS FOR FOG LATER IN THE NIGHT, SURFACE ANALYSIS AND MODEL FORECASTS INDICATE TOO MUCH GRADIENT FLOW FOR MUCH OF AN OBSTRUCTION BUT SOME LIGHT HAZE SHOULD BE EXPECTED AS SURFACE DEWPOINT APPROACHES 70F. THESE EXPECTATIONS MAY CHANGE MORE IN FAVOR OF FOG DEPENDING ON HOW THE WIND FIELD SHAPES UP DURING THE NIGHT. && .PREV DISCUSSION...ISSUED 411 PM EDT THU JUN 12 2008 SHORT TERM...TONIGHT SURFACE WARM FRONT POSITIONED FROM A CHICAGO TO FINDLEY LINE WITH SOUTHEASTERLY BACKED FLOW...COMBINED WITH PLENTY OF HIGH CLOUD DEBRIS...KEEPING TEMPERATURES NEAR 80 IN MOST AREAS AS OF 3PM. WILL EXPECT INLAND AREAS FROM ADRIAN TO OWOSSO TO SEE A FEW MORE DEGREE CLIMB THIS EVENING AS WINDS BEGIN TO BACK TO THE SOUTH LATE...WHILE LOCATIONS CLOSER TO LAKE HURON WILL STRUGGLE TO CLIMB ABOVE 80. THE HIGHER DEWPOINTS HAVE ALSO BEEN SLOW TO ARRIVE... FINALLY CREEPING INTO THE MID 60S IN THE FAR SOUTH. AN 18Z TAMDAR SOUNDING OUT OF DTW SHOWS MOISTURE STARTING TO INCREASE ABOVE 800MB BUT ALSO SHOWS A CAP IN PLACE NEAR 925MB. WE WILL NEED TO SEE TEMPS/DEWPOINTS APPROACH 85/67 TO BREAK THROUGH THIS CAP FOR AN ISOLATED THUNDERSTORM THIS EVENING...WHICH ADRIAN IS APPROACHING. HAVE REMOVED THE ISOLATED THUNDERSTORMS WORDING IN THE NORTHERN AREAS BUT WILL CONTINUE TO CARRY AN ISOLATED THUNDERSTORMS FROM DETROIT SOUTH TO THE OHIO BORDER WHERE SURFACE BASED CAPES ARE AROUND 1500 J/KG. SPC MESO-ANALYSIS SHOWS ENHANCED 850MB MOISTURE OVER OHIO ALSO TRYING TO PUSH NORTH INTO THIS AREA WITH WEAK LOW LEVEL CONVERGENCE ALSO IN PLACE. UPSTREAM SHOWERS AND THUNDERSTORMS DEVELOPING OVER ILLINOIS/WISCONSIN WILL CONTINUE TO TRACK NORTHEAST TOWARDS THE UPPER PENINSULA AS UPPER TROUGH OVER THE PLAINS PUSHES EASTWARD WITH DEEP SOUTH SOUTHWESTERLY FLOW. ADDITIONAL AND POTENTIALLY STRONG THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER ILLINOIS AND TRACK INTO WESTERN LOWER OVERNIGHT AS 45+ KNOT LOW LEVEL JET NOSES INTO THIS AREA. WILL EXPECT THIS ACTIVITY TO BE WEAKENING AS IT APPROACHES THE TRI-CITIES LATE TONIGHT REACHING THE WARMER MID-LEVELS UNDERNEATH THE STRONG UPPER RIDGE. HOWEVER IF THIS CONVECTION CAN REMAIN ORGANIZED...AN ISOLATED SEVERE STORM IS NOT OUT OF THE QUESTION. WILL INCREASE POPS TO 60 PERCENT IN THIS AREA AFTER 6 AM WHILE JUST CARRYING A CHANCE OF SHOWERS AND THUNDERSTORMS AFTER MIDNIGHT ELSEWHERE. LONG TERM...FRIDAY THROUGH THURSDAY FRIDAY/FRIDAY NIGHT IS SHAPING UP TO BE AN INTERESTING TIME FRAME AS A 100+ KNOT JET LIFTS NORTH/NORTHEAST UP THE FRONT SIDE OF THE LARGE UPPER TROUGH OVER THE CENTRAL NOAM INTO THE UPPER MIDWEST/WESTERN GREAT LAKES. BY LATE IN THE DAY...LIFT WITHIN THE RIGHT ENTRANCE REGION OF THIS JET WILL BE SPREADING EAST INTO LAKE MICHIGAN/WESTERN LOWER MICHIGAN ON SOUTH INTO ILLINOIS/INDIANA. WITH THIS UPPER LEVEL SUPPORT...WOULD EXPECT SHOWERS/THUNDERSTORMS TO ERUPT FROM SOUTHWEST LOWER MICHIGAN INTO ILLINOIS/INDIANA AND THEN SPREAD NORTHEAST INTO THE AREA DURING THE LATE AFTERNOON/EVENING HOURS AS THE ASSOCIATED SURFACE FRONTAL BOUNDARY PUSHES INTO THE REGION. THIS PART OF THE SCENARIO...TIMING THE LARGE SCALE LIFT/FORCING...IS THE EASY PART. THE COMPLICATING FACTOR FOR THIS FORECAST WILL BE ANY RESIDUAL ACTIVITY FROM OVERNIGHT SHOWERS/THUNDERSTORMS THAT PERSISTS INTO THE MORNING HOURS...AND WHAT THIS MAY DO TO LIMIT INSTABILITY. AS IT IS...WOULD EXPECT THE AIRMASS THAT ADVECTS INTO THE REGION ON STRENGTHENING SOUTH/SOUTHWEST FLOW TO SUPPORT MLCAPES NEAR 2000 J/KG SO LONG AS EXTENSIVE CONVECTIVE DEBRIS DOES NOT LINGER INTO THE MID AFTERNOON. WITH MID LEVEL FLOW IN THE 40-50 KNOT RANGE...SOME STORMS WILL LIKELY BECOME SEVERE...AND GIVEN ONLY SLIGHT DIRECTIONAL CHANGE IN THE SOUTHWESTERLY WIND FIELD...THE MAIN HAZARD WOULD BE DAMAGING WINDS. AT A MINIMUM...WILL BE LEAVING LIKELY POPS (60-70%) IN THE FORECAST FOR THE AREA...AND WILL MOST LIKELY PROBABLY ATTEMPT TO DEFINE AN AREA OF EVEN GREATER CHANCE (80%)...AS THE CHANCE OF RAIN SEEMS QUITE GOOD. WILL JUST HAVE TO MONITOR OVERNIGHT CONVECTION TO BETTER ASSESS SEVERE POTENTIAL. THIS WHOLE SYSTEM WILL THEN PROGRESS TO THE EAST OVERNIGHT FRIDAY NIGHT...WITH DRY WEATHER EXPECTED ON SATURDAY/SATURDAY NIGHT AS A RIDGE OF HIGH PRESSURE BUILDS EAST THROUGH THE AREA. DURING THIS TIME FRAME...THE CENTRAL NOAM UPPER TROUGH BECOMES CENTERED OVER CANADA WITH A BROAD...NEARLY ZONAL FLOW OVER THE NORTHERN TIER OF STATES. SEVERAL DISTURBANCES WILL PROGRESS THROUGH THE AREA WITHIN THIS FLOW REGIME...MAINLY IN THE SUNDAY/SUNDAY NIGHT TIME FRAME. THIS WILL BRING ANOTHER CHANCE OF SHOWERS/THUNDERSTORMS...WHICH COULD LINGER INTO MONDAY. DID ADJUST THE FORECAST SLIGHTLY FOR TIMING...BUT KEPT POPS GOING IN THIS TIME FRAME. AFTER THESE DISTURBANCES PROGRESS OFF TO THE EAST...THE UPPER TROUGH WILL RECENTER OVER THE EASTERN CONUS...WITH NORTHWEST FLOW BECOMING ESTABLISHED. A LARGE HIGH PRESSURE SETTLES INTO THE CENTRAL PART OF THE NATION...BRINGING QUIET WEATHER FOR THE REST OF THE FORECAST. TEMPERATURES WILL ALSO BE COOLER WITH HIGHS IN THE UPPER 60S TO 70S AND LOWS GENERALLY IN THE 50S. HUMIDITY LEVELS WILL ALSO BE RATHER PLEASANT AS THE FLOW OUT OF CANADA PERSIST INTO LATE NEXT WEEK. MARINE... A PREDOMINANT SOUTHEAST WIND WILL CONTINUE ACROSS ALL MARINE AREAS INTO THIS EVENING...WITH GUSTS OF 20 TO 25 KNOTS ON LAKE HURON. THIS PERSISTENT ONSHORE FLOW WILL RESULT IN HIGHER WAVES AND AN INCREASED THREAT OF RIP CURRENTS TONIGHT...BEFORE THE FLOW BECOMES SOUTH LATE TONIGHT INTO FRIDAY. WILL LEAVE CURRENT HEADLINES THIS EVENING AND OVERNIGHT IN PLACE FOR LAKE HURON...BUT CANCEL THEM OVER LAKE ST CLAIR AND WESTERN LAKE ERIE WHERE WINDS ARE STARTING TO SUBSIDE AS WE STABILIZE. ALTHOUGH THERE WILL BE A CHANCE OF THUNDERSTORMS TONIGHT...A GREATER THREAT FOR STORMS EXISTS ON FRIDAY INTO FRIDAY NIGHT AS A COLD FRONT SWEEPS ACROSS LOWER MICHIGAN. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON... SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT HURON...UNTIL 6 AM FRIDAY. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....BT SHORT TERM...KEC LONG TERM....DG MARINE.......DG YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
411 PM EDT THU JUN 12 2008 .SHORT TERM...TONIGHT SURFACE WARM FRONT POSITIONED FROM A CHICAGO TO FINDLEY LINE WITH SOUTHEASTERLY BACKED FLOW...COMBINED WITH PLENTY OF HIGH CLOUD DEBRIS...KEEPING TEMPERATURES NEAR 80 IN MOST AREAS AS OF 3PM. WILL EXPECT INLAND AREAS FROM ADRIAN TO OWOSSO TO SEE A FEW MORE DEGREE CLIMB THIS EVENING AS WINDS BEGIN TO BACK TO THE SOUTH LATE...WHILE LOCATIONS CLOSER TO LAKE HURON WILL STRUGGLE TO CLIMB ABOVE 80. THE HIGHER DEWPOINTS HAVE ALSO BEEN SLOW TO ARRIVE... FINALLY CREEPING INTO THE MID 60S IN THE FAR SOUTH. AN 18Z TAMDAR SOUNDING OUT OF DTW SHOWS MOISTURE STARTING TO INCREASE ABOVE 800MB BUT ALSO SHOWS A CAP IN PLACE NEAR 925MB. WE WILL NEED TO SEE TEMPS/DEWPOINTS APPROACH 85/67 TO BREAK THROUGH THIS CAP FOR AN ISOLATED THUNDERSTORM THIS EVENING...WHICH ADRIAN IS APPROACHING. HAVE REMOVED THE ISOLATED THUNDERSTORMS WORDING IN THE NORTHERN AREAS BUT WILL CONTINUE TO CARRY AN ISOLATED THUNDERSTORMS FROM DETROIT SOUTH TO THE OHIO BORDER WHERE SURFACE BASED CAPES ARE AROUND 1500 J/KG. SPC MESO-ANALYSIS SHOWS ENHANCED 850MB MOISTURE OVER OHIO ALSO TRYING TO PUSH NORTH INTO THIS AREA WITH WEAK LOW LEVEL CONVERGENCE ALSO IN PLACE. UPSTREAM SHOWERS AND THUNDERSTORMS DEVELOPING OVER ILLINOIS/WISCONSIN WILL CONTINUE TO TRACK NORTHEAST TOWARDS THE UPPER PENINSULA AS UPPER TROUGH OVER THE PLAINS PUSHES EASTWARD WITH DEEP SOUTH SOUTHWESTERLY FLOW. ADDITIONAL AND POTENTIALLY STRONG THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER ILLINOIS AND TRACK INTO WESTERN LOWER OVERNIGHT AS 45+ KNOT LOW LEVEL JET NOSES INTO THIS AREA. WILL EXPECT THIS ACTIVITY TO BE WEAKENING AS IT APPROACHES THE TRI-CITIES LATE TONIGHT REACHING THE WARMER MID-LEVELS UNDERNEATH THE STRONG UPPER RIDGE. HOWEVER IF THIS CONVECTION CAN REMAIN ORGANIZED...AN ISOLATED SEVERE STORM IS NOT OUT OF THE QUESTION. WILL INCREASE POPS TO 60 PERCENT IN THIS AREA AFTER 6 AM WHILE JUST CARRYING A CHANCE OF SHOWERS AND THUNDERSTORMS AFTER MIDNIGHT ELSEWHERE. && .LONG TERM...FRIDAY THROUGH THURSDAY FRIDAY/FRIDAY NIGHT IS SHAPING UP TO BE AN INTERESTING TIME FRAME AS A 100+ KNOT JET LIFTS NORTH/NORTHEAST UP THE FRONT SIDE OF THE LARGE UPPER TROUGH OVER THE CENTRAL NOAM INTO THE UPPER MIDWEST/WESTERN GREAT LAKES. BY LATE IN THE DAY...LIFT WITHIN THE RIGHT ENTRANCE REGION OF THIS JET WILL BE SPREADING EAST INTO LAKE MICHIGAN/WESTERN LOWER MICHIGAN ON SOUTH INTO ILLINOIS/INDIANA. WITH THIS UPPER LEVEL SUPPORT...WOULD EXPECT SHOWERS/THUNDERSTORMS TO ERUPT FROM SOUTHWEST LOWER MICHIGAN INTO ILLINOIS/INDIANA AND THEN SPREAD NORTHEAST INTO THE AREA DURING THE LATE AFTERNOON/EVENING HOURS AS THE ASSOCIATED SURFACE FRONTAL BOUNDARY PUSHES INTO THE REGION. THIS PART OF THE SCENARIO...TIMING THE LARGE SCALE LIFT/FORCING...IS THE EASY PART. THE COMPLICATING FACTOR FOR THIS FORECAST WILL BE ANY RESIDUAL ACTIVITY FROM OVERNIGHT SHOWERS/THUNDERSTORMS THAT PERSISTS INTO THE MORNING HOURS...AND WHAT THIS MAY DO TO LIMIT INSTABILITY. AS IT IS...WOULD EXPECT THE AIRMASS THAT ADVECTS INTO THE REGION ON STRENGTHENING SOUTH/SOUTHWEST FLOW TO SUPPORT MLCAPES NEAR 2000 J/KG SO LONG AS EXTENSIVE CONVECTIVE DEBRIS DOES NOT LINGER INTO THE MID AFTERNOON. WITH MID LEVEL FLOW IN THE 40-50 KNOT RANGE...SOME STORMS WILL LIKELY BECOME SEVERE...AND GIVEN ONLY SLIGHT DIRECTIONAL CHANGE IN THE SOUTHWESTERLY WIND FIELD...THE MAIN HAZARD WOULD BE DAMAGING WINDS. AT A MINIMUM...WILL BE LEAVING LIKELY POPS (60-70%) IN THE FORECAST FOR THE AREA...AND WILL MOST LIKELY PROBABLY ATTEMPT TO DEFINE AN AREA OF EVEN GREATER CHANCE (80%)...AS THE CHANCE OF RAIN SEEMS QUITE GOOD. WILL JUST HAVE TO MONITOR OVERNIGHT CONVECTION TO BETTER ASSESS SEVERE POTENTIAL. THIS WHOLE SYSTEM WILL THEN PROGRESS TO THE EAST OVERNIGHT FRIDAY NIGHT...WITH DRY WEATHER EXPECTED ON SATURDAY/SATURDAY NIGHT AS A RIDGE OF HIGH PRESSURE BUILDS EAST THROUGH THE AREA. DURING THIS TIME FRAME...THE CENTRAL NOAM UPPER TROUGH BECOMES CENTERED OVER CANADA WITH A BROAD...NEARLY ZONAL FLOW OVER THE NORTHERN TIER OF STATES. SEVERAL DISTURBANCES WILL PROGRESS THROUGH THE AREA WITHIN THIS FLOW REGIME...MAINLY IN THE SUNDAY/SUNDAY NIGHT TIME FRAME. THIS WILL BRING ANOTHER CHANCE OF SHOWERS/THUNDERSTORMS...WHICH COULD LINGER INTO MONDAY. DID ADJUST THE FORECAST SLIGHTLY FOR TIMING...BUT KEPT POPS GOING IN THIS TIME FRAME. AFTER THESE DISTURBANCES PROGRESS OFF TO THE EAST...THE UPPER TROUGH WILL RECENTER OVER THE EASTERN CONUS...WITH NORTHWEST FLOW BECOMING ESTABLISHED. A LARGE HIGH PRESSURE SETTLES INTO THE CENTRAL PART OF THE NATION...BRINGING QUIET WEATHER FOR THE REST OF THE FORECAST. TEMPERATURES WILL ALSO BE COOLER WITH HIGHS IN THE UPPER 60S TO 70S AND LOWS GENERALLY IN THE 50S. HUMIDITY LEVELS WILL ALSO BE RATHER PLEASANT AS THE FLOW OUT OF CANADA PERSIST INTO LATE NEXT WEEK. && .MARINE... A PREDOMINANT SOUTHEAST WIND WILL CONTINUE ACROSS ALL MARINE AREAS INTO THIS EVENING...WITH GUSTS OF 20 TO 25 KNOTS ON LAKE HURON. THIS PERSISTENT ONSHORE FLOW WILL RESULT IN HIGHER WAVES AND AN INCREASED THREAT OF RIP CURRENTS TONIGHT...BEFORE THE FLOW BECOMES SOUTH LATE TONIGHT INTO FRIDAY. WILL LEAVE CURRENT HEADLINES THIS EVENING AND OVERNIGHT IN PLACE FOR LAKE HURON...BUT CANCEL THEM OVER LAKE ST CLAIR AND WESTERN LAKE ERIE WHERE WINDS ARE STARTING TO SUBSIDE AS WE STABILIZE. ALTHOUGH THERE WILL BE A CHANCE OF THUNDERSTORMS TONIGHT...A GREATER THREAT FOR STORMS EXISTS ON FRIDAY INTO FRIDAY NIGHT AS A COLD FRONT SWEEPS ACROSS LOWER MICHIGAN. && .PREV DISCUSSION...ISSUED 211 PM EDT THU JUN 12 2008 AVIATION... VFR CONDITIONS WILL CONTINUE TODAY WITH THE CHANCE THAT AN ISOLATED THUNDERSTORM MAY DEVELOP LATE THIS AFTERNOON TOWARDS DETROIT. WILL LEAVE THIS OUT OF THE TAFS AS THE CHANCE OF OCCURRENCE IS QUITE SMALL WITH DRY AIR IN THE MID-LEVELS. CONSIDERABLE HIGH CLOUDINESS CREATED FROM A LARGE THUNDERSTORM COMPLEX UPSTREAM WILL CONTINUE TO BLANKET THE AREA THROUGH TONIGHT. SCT-BKN CLOUDS AROUND 5000 FEET WILL BEGIN SPREADING IN LATE TONIGHT FROM THE WEST AHEAD OF AN APPROACHING COLD FRONT. SHOWERS WITH SCATTERED THUNDERSTORMS WILL APPROACH MBS AFTER 09Z WITH MVFR CONDITIONS EXPECTED...LIKELY APPROACHING THE DETROIT AREA TOWARDS 18Z. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON... SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT HURON...UNTIL 6 AM FRIDAY. SMALL CRAFT ADVISORY...OUTER SAGINAW BAY...UNTIL 8 PM THURSDAY. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ SHORT TERM...KEC LONG TERM....DG MARINE.......DG AVIATION.....KEC YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
546 AM CDT WED JUN 11 2008 .DISCUSSION... SEVERE WEATHER CONTINUES TO BREAK OUT OVER FAR EASTERN SODAK THIS TIME FRAME. MAIN THREAT WITH SAID STORMS WILL CONTINUE TO BE HAIL STONES AND OCCASIONAL DOWNDRAFTS. SURFACE 997MB LOW PRESSURE SYSTEM OVER NORTH CENTRAL NE PROGGED TO TREK INTO SE SODAK BY EARLY THIS AFTERNOON...AND WEAKEN INTO AN INVERTED TROUGH BY EARLY THIS EVENING. MAIN THREAT STILL APPEARS TO BE HEAVY RAINFALL...AS PWATS IN THE 1.6 TO 1.8 INCH RANGE EXPECTED TO MATERIALIZE ACROSS MUCH OF EASTERN HALF OF FA DURING THE NEXT 12 TO 18 HOURS. NORMAL FOR THIS TIME OF YEAR BY THE WAY IS IN THE .80 TO .85 RANGE. VERY STRONG 1000-850MB THETA E ADVECTION PER GFS40 PRETTY MUCH NAILS CONVECTION CURRENTLY OCCURRING ACROSS EASTERN PORTION OF DAKOTAS. THIS FEATURE ALONG WITH DEPICTION OF 50H CLOSED LOW ABOVE CENTRAL MT PER VAPOR LOOP HAS PROMPTED ME TO USE THIS AS MODEL OF CHOICE FOR CURRENT FORECAST PACKAGE. CONVECTION WILL CONTINUE TO BE WELL CONTAINED PRIOR TO 12Z OVER ALL BUT EXTREME WESTERN CWA. 310K ISENTROPIC SURFACE PROJECTS AN EXPLOSION OF MOISTURE AND FORCING ACROSS MUCH OF THE FA PRIOR TO 18Z...WITH MOST OF MOISTURE CLEARLY NOTED OVER CENTRAL MN AND NW WI. BEST CHANCE FOR SEVERE WEATHER REMAINDER OF MORNING WILL CONTINUE ACROSS FAR WEST CENTRAL MN...IN ASSOCIATION WITH STRONG DIVERGENCE COUPLETS...BEST LI`S MID LEVEL CAPE...STEEPEST LAPSE RATES...AND THETA E ADVECTION. CAP WILL CONTINUE TO BE IN PLACE OVER FAR SW MN INTO EARLY THIS AFTERNOON. WARM FRONTAL BOUNDARY NEAR THE MN/IA BORDER...WILL MOVE NORTH DURING THE DAYLIGHT HOURS...AND EXTEND FROM NEAR A LINE FROM KEAU TO KSTC TO KFFM BY LATE THIS AFTERNOON. OF COURSE...THE AREA NEAR AND JUST TO THE NORTH OF THIS BOUNDARY WILL BE THE FOCUS OF THE HEAVIEST PRECIPITATION PRIOR TO 00Z. AFTER 00Z A DOUBLE BARRELED LOW PRESSURE SYSTEM WILL FORM WITH THE NORTHERN WAVE TRAVERSING MUCH OF CENTRAL MN DURING THE EVENING AND INTO THE EARLY MORNING HOURS ON THU. A SURGE OF MOISTURE IS EXPECTED ALONG THE TRAILING COLD FRONT...WITH BEST MOISTURE FLUX CONVERGENCE ANTICIPATED JUST AHEAD OF IT DURING THE 00Z-06Z TIME FRAME TONIGHT. ALTHOUGH COND PRESSURE DEFICITS PER 310K CHART BECOME QUITE DIFFUSE DURING THIS TIME FRAME...A MASSIVE 250MB DIVERGENCE COUPLET FORMS IN THE RIGHT REAR QUAD OF A 145KT JET CORE PROGGED OVER EASTERN NODAK BY MIDNIGHT. THIS FEATURE COULD BE THE MAIN EVENT FOR SEVERE WEATHER THIS GO AROUND. TOGGIE TOOL YIELDING A CHANCE THREAT FOR TWISTERS OVER FAR SW MN DURING THE EVENING HOURS. BEST FLASH FLOOD THREAT THIS JUNCTURE CONTINUES TO POINT TO FAR SOUTHERN MN WHERE BEST MOISTURE TONGUE ANTICIPATED TO DEVELOP LATE THIS AFTERNOON INTO THE EVENING...AND WHERE MOST RECENT HEAVY PRECIPITATION HAS FALLEN. OVERALL LOOK FOR RAINFALL AMOUNTS OVER WARNED AREA TO RANGE FROM THREE QUARTERS TO JUST OVER 2 INCHES OF RAINFALL. FAST PROGRESSION OF COLD FRONTAL BOUNDARY LATER TONIGHT HAS LESSENED THE THREAT ACROSS WI. LOOKS LIKE REMAINDER OF WEEK WILL SHAPE UP TO BE NEAR OR SLIGHTLY BELOW NORMAL FOR TEMPS ...AS CLOSED MID LEVEL LOW PUMPS IN COPIOUS AMOUNTS OF POLAR AIR ACROSS THE EASTERN HALF OF THE UPPER MIDWEST. && .AVIATION.../12Z TAF ISSUANCE/ THUNDERSTORMS WILL SPREAD NORTH AND EAST TOWARDS THE TAF SITES THROUGH 15Z...REACHING RWF BEFORE THAT. A SURGE OF ELEVATED UNSTABLE AND MOIST AIR IS DRIVING THESE THUNDERSTORMS. THE CHANGE IN STABILITY IS FAIRLY GREAT...ENOUGH TO DRIVE SEVERE THUNDERSTORMS ESPECIALLY BY RWF. SOME OF THESE MAY CONTAIN HAIL AND STRONGER WINDS...POSSIBLY WITH GUSTS TO NEAR 60 MPH WHICH WERE OBSERVED IN NRN SD EARLIER THIS MORNING IN A SIMILAR ATMOSPHERE. TOWARDS MSP IN THE MORNING...RECENT TAMDAR SOUNDING INDICATED LAPSE RATES IN THE MID-LEVELS NOT AS GREAT TO DRIVE SEVERE STORMS SO UNLIKELY FOR HAIL IN THE MORNING...BUT MORE POSSIBLE BY AFTN. BRIEF IFR CONDITIONS ARE POSSIBLE UNDER ANY MORNING STORMS AS WELL. THESE STORMS WILL GRADUALLY LIFT NORTHEAST AND WEAKEN DURING THE EARLY TO MID AFTN...BUT MORE WILL DEVELOP IN WRN AND SRN MN DURING THE LATE AFTN. MVFR AND IFR CIGS ALONG WITH DRIZZLE POSSIBLE IN BETWEEN THUNDERSTORMS AS LOWER TROP MOISTURE IS QUITE HIGH. SECOND ROUND OF THUNDERSTORMS FROM LATE AFTN NEAR RWF EVOLVING TOWARDS THE OTHER TAF SITES DURING THE EVENING WILL ALSO HAVE THE POTENTIAL TO BE SEVERE. THUNDER INDICES ARE HIGHEST IN THE EVENING AND HAVE THUNDER PREVAILING FOR A PERIOD DURING THAT TIME AT MOST TAF SITES.EFFICIENT PRECIP GENERATION ALONG WITH AN ANTECEDENT MOIST ATMOSPHERE WILL LEAD TO BETTER CHANCES FOR IFR CONDITIONS WITH THIS LATER BATCH AS WELL IN HEAVIER RAINFALL. ALSO...LOW LEVEL WIND SHEAR EXISTS FOR A FEW HOURS AT WI TAF SITES AS WINDS AT THE SFC HAVE BEEN SLOW TO PICK UP IN THAT AREA BUT MPX VAD PROFILER ALONG WITH DIAGNOSTIC MODELS INDICATING 40 KT ERLY WINDS NOT FAR OFF THE DECK. WINDS WILL ALSO BE BREEZY TODAY AND THIS EVE...GUSTING AT TIMES TO NEAR OR EVEN SLIGHTLY ABOVE 30 KTS AT MN TAF SITES. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR ANOKA-BLUE EARTH-BROWN-CARVER-CHISAGO-DAKOTA-FARIBAULT-FREEBORN- GOODHUE-HENNEPIN-LE SUEUR-MARTIN-NICOLLET-RAMSEY-RICE-SCOTT- SIBLEY-STEELE-WASECA-WASHINGTON-WATONWAN. WI...FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR BARRON-CHIPPEWA- DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST. CROIX. && $$ AZ/MTF
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
200 AM PDT FRI JUN 13 2008 .SYNOPSIS... HIGH PRESSURE ALOFT WILL INCREASE THROUGH SATURDAY WITH A SLIGHT DECREASE SUNDAY...THEN LITTLE CHANGE UNTIL WEDNESDAY AND THURSDAY WHEN HIGH PRESSURE ALOFT WILL DECREASE A BIT MORE. A TROUGH AND UPPER LEVEL LOW PRESSURE SYSTEM WILL SLOWLY MOVE SOUTH JUST OFF THE COAST OF CANADA. IT WILL BE JUST NORTHWEST OF VANCOUVER ISLAND BY THURSDAY. THE MARINE LAYER WILL DECREASE THROUGH SATURDAY. IT WILL INCREASE ABOUT THE MIDDLE OF NEXT WEEK. SOME DENSE FOG MAY DEVELOP MAINLY NEAR THE COAST TONIGHT AND SATURDAY MORNING. NO SIGNIFICANT WINDS EXCEPT LOCALLY BREEZY IN THE MOUNTAINS AND DESERTS IN THE AFTERNOONS AT TIMES. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... MARINE LAYER HAVING AN EASIER TIME MOVING INTO ORANGE COUNTY THAN SAN DIEGO COUNTY EARLY THIS MORNING. EXPECT LOW CLOUDS TO COVER MOST OF THE COASTAL AREAS AND MOVE INTO THE WEST PART OF THE INLAND VALLEYS IN SAN DIEGO COUNTY BY SUNRISE. SOME EARLY MORNING FOG MAY DEVELOP IN THE WEST PART OF THE INLAND EMPIRE. HIGH PRESSURE ALOFT BUILDS IN FROM THE SOUTHEAST THROUGH SATURDAY. THE HIGH DROPS SOUTH SLIGHTLY SUNDAY BUT THERE WILL BE LITTLE CHANGE THROUGH TUESDAY. THE MARINE LAYER MAY BECOME NON-EXISTENT BY SUNDAY MORNING BUT SOME LOW CLOUDS ARE EXPECTED LATE NIGHT AND EARLY MORNING NEAR THE COAST. AN UPPER LEVEL LOW IS FORECAST TO DROP SLOWLY SOUTH ALONG THE CANADIAN COAST. BY WEDNESDAY AND THURSDAY A WEAK TROUGH IS FORECAST TO DECREASE HIGH PRESSURE OVER SOCAL A BIT MORE. THE MARINE LAYER WILL INCREASE A LITTLE BY THE MIDDLE OF NEXT WEEK WITH A BIT MORE EXTENSIVE NIGHT AND MORNING LOW CLOUDS. PRESSURE GRADIENTS INCREASE AT TIMES DURING THE AFTERNOONS FOR BREEZY WINDS IN THE MOUNTAINS AND DESERTS OCCASIONALLY. MID AND HIGH CLOUDS ARE FORECAST TO MOVE OVER SOCAL SATURDAY AND SUNDAY. MODELS HAVING SECOND THOUGHTS ABOUT WHAT TO DO WITH THE UPPER LEVEL LOWS AND TROUGHS MOSTLY ROTATING THROUGH CANADA OR DROPPING SOUTH OFF THE COAST. ECMWF MOSTLY KEEPS HIGH PRESSURE OVER THE AREA ALTHOUGH IT AGREES WITH THE GFS WITH A TROUGH DECREASING HIGH PRESSURE ALOFT ON WEDNESDAY AND THURSDAY NEXT WEEK. IT WOULD APPEAR THAT HIGH PRESSURE WILL BE MOSTLY IN CONTROL FOR THE NEXT SEVERAL DAYS. IT REMAINS TO BE SEEN IF THE MARINE LAYER WILL DRY UP OFF SOCAL. EXPECT SOME STRATUS TO REMAIN LATE NIGHT AND EARLY MORNING NEAR THE COAST. && .AVIATION... 130800Z...MDCRS SOUNDINGS INDICATE THE MARINE LAYER DEPTH WAS AROUND 1800 FEET THIS MORNING. SOME LOWERING IS EXPECTED TODAY TO AROUND 1500 FEET BY THIS AFTERNOON AND TONIGHT. COASTAL STRATUS WITH BASES AROUND 1500 FEET MSL IS SOMEWHAT DISRUPTED ALONG THE COAST AT THIS TIME BUT IS SHOWING SIGNS OF BECOMING BETTER ORGANIZED...ESPECIALLY OFF ORANGE COUNTY AND NORTHERN SAN DIEGO COUNTY. EXPECT THE STRATUS TO FILL IN ALONG THE COAST AND SPREAD INLAND BETWEEN NOW AND SUNRISE WITH SOME STRATUS REACHING NEAR KONT BY SUNRISE. STRATUS SHOULD BEGIN TO BURN OFF OVER THE INLAND AREAS BY 15Z AND CLEAR TO THE COAST BETWEEN 16Z AND 17Z. EXPECT STRATUS TO RETURN TO THE COASTLINE BY SUNRISE AND SPREAD INLAND DURING THE LATE EVENING. ABOVE THE MARINE LAYER INCLUDING THE MOUNTAINS AND DESERTS...A MOSTLY CLEAR SKY WITH UNRESTRICTED VISIBILITIES WILL CONTINUE THROUGH SATURDAY. FOR DENSITY ALTITUDE PLANNING...MAXIMUM TEMPERATURE AT KPSP AND KTRM IS EXPECTED TO BE 40 TO 42 DEG C TODAY AND SATURDAY. KONT SHOULD REACH 30 DEG C TODAY AND 33 DEG ON SATURDAY. TEMPERATURES AT THE COASTAL AIRPORTS SUCH AS KSNA AND KSAN IS NOT EXPECTED TO EXCEED 25C TODAY AND SATURDAY. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC...WHITLOW AVIATION/MARINE...HORTON NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
345 AM EDT FRI JUN 13 2008 .DISCUSSION... 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR LO NEAR THE ND/CNDN BORDER DRIFTING SLOWLY EWD BTWN RDG OVER THE PAC NW AND HI AMPLITUDE RDG STRETCHING FM HUDSON BAY TO THE SE STATES. SURGE OF MSTR AHD OF THIS TROF WITH 02Z TAMDAR SDNG FM SAW SHOWING 190/50KT WIND AT H910 AND PWAT AS HI AS 2 INCHES AT DVN HAS FUELED RIBBON OF SHRA/TSRA THAT IS NOW IMPACTING THE SE PART OF THE FA. ALTHOUGH UPR LO AND ATTENDANT SFC COLD FNT REMAINS TO THE W IN MN...ARRIVAL OF DRIER AIR SHOWN ON THE 00Z MPX SDNG IN THE SW FLOW ALF AHEAD OF THE SFC FNT HAS CAUSED THE PCPN OVER THE W HALF OF THE FA TO DIMINISH TO JUST ISOLD -SHRA. WHERE DRYING ALF HAS OCCURRED OVER THE W...SOME PLACES ARE REPORTING VSBY AS LO AS 1/4SM IN FG. CLOSER TO THE SFC COLD FNT/UPR LO (WHERE H5 TEMPS ARE AOB -20C AS FAR E AS INL)...SOME SHRA/TSRA ARE IMPACTING NCNTRL MN. MUCH COLDER LLVL AIR IS NOTED TO THE W OF THE UPR LO POSITIONS WITH 00Z H85 TEMPS 5C AT BIS/GGW. MAIN FCST CONCERNS THIS PACKAGE INVOLVE SHRA/TSRA CHCS WITH SHRTWVS ROTATING ARND UPR LO NOW IN THE NRN PLAINS THAT IS FCST TO DRIFT SLOWLY EWD THE NEXT COUPLE OF DAYS. FOR TDAY...NAM/GFS SHOW UPR LO DRIFTING NEWD INTO NW ONTARIO THRU 00Z SAT. WSW FLOW ON THE SE FLANK OF THIS SYS LOOKS TO ADVECT VERY DRY AIRMASS SHOWN ON THE 00Z MPX RAOB. THIS MOTION OF THE UPR LO WL ALSO RESTRICT THE TEMP DROP ALF...WITH CORE OF -20C AIR AT H5 REMAINING WELL TO THE NW. IN FACT...NAM/GFS FCST SDNGS SHOW FAIRLY IMPRESSIVE MID LVL CAPPING DVLPG ABV H7-6 AND LIMITING DEPTH OF ANY UPDRAFTS ABV RELATIVELY HI LCL NR H85. SO...EVEN THOUGH SFC COLD FNT WL DRIFT INTO THE WRN ZNS THIS AFTN...THINK CHCS OF CNVCTN ALG THIS BNDRY WL BE QUITE A BIT LESS THAN OBSVD IN MN YDAY AFTN/EVNG. CONSIDERING THE STRENGTH OF THE CAP/LO EQUILIBRIUM LVL WITH ENVIRONMENTAL TEMP ABV -10C AT THAT LVL...REMOVED MENTION OF TS AND JUST MENTIONED ISOLD -SHRA WITH 00Z SAT FCST KINX AT IWD ONLY ARND 20. OTRW...ANY MRNG FOG/ST WL DSPT QUICKLY WITH ARRIVAL OF DRY AIR/ DIURNAL HTG/MIXING. AS FOR TEMPS...WL TEND TO BUMP UP FCST MAX TEMPS THIS AFTN CONSIDERING UPSTREAM REPORTS IN THE UPR 70S OVER SRN MN YDAY AND MIXING TO H75 OVER THE CNTRL ZNS ON GFS/NAM FCST SDNGS. EXPECT LOWER HI TEMPS DOWNWIND OF LK MI AND OVER THE W. AS UPR LO OVER NW ONTARIO DRIFTS OFF TO THE NE TNGT...A SHRTWV ROTATING ARND THIS FEATURE IS FCST TO PUSH INTO THE MN ARROWHEAD BY 12Z SAT. IN THE ABSENCE OF DIURNAL HTG AND UNDER DRY/STABLE AIRMASS ALF...MOST OF THE NGT WL BE QUIET AHD OF THIS NEXT FEATURE. ANY ISOLD -SHRA OVER THE W THIS AFTN WL END QUICKLY WITH LOSS OF DIURNAL HTG...PROBABLY BY 00Z. INTRODUCED SLGT CHC POPS LATE OVER WRN LK SUP TO ACCOUNT FOR INCOMING H5 THERMAL TROFFING/WEAKENING OF MID LVL CAP/MID LVL MOISTENING AHD OF APRCHG SHRTWV IN MN. COMBINATION OF INCOMING SHRTWV/DIURNAL HTG WL RESULT IN SCT SHRA/ TSRA ON SAT AS H5 THERMAL TROF (TEMPS AS LO AS -18C) SWINGS OVHD WITH SHRTWV AND CONVECTIVE TEMPS ARE FCST IN THE MID 60S. SINCE THE ARRIVAL OF THE SHRTWV WL BE BEST IN SYNC WITH THE SOLAR HTG CYCLE OVER THE CNTRL AND E...WL PAINT A BIT HIER CHC POPS THERE... ESPECIALLY OVER THE INTERIOR WHERE BREEZE OFF LK MI MIGHT ENHANCE LLVL CNVGC A BIT. DESPITE ARRIVAL OF H5 THERMAL TROFFING...GFS/NAM FCST SDNGS SHOW ONLY MODEST MID LVL LAPSE RATES...SO THREAT OF SVR TS SHOULD BE MINIMAL DESPITE RATHER IMPRESSIVE 0-6KM BULK SHEAR FCST IN THE 40 KT RANGE. LO WBZ FCST ARND 8.5K FT WOULD SUPPORT MORE LIKE PEA SIZED HAIL UNDER THE STRONGER CNVCTN. WITH CONVECTIVE TEMPS SO LO AND MORE CLD ARND... HI TEMPS WL BE QUITE A BIT LOWER THAN TDAY. PREFER TO TEND TOWARD THE LOWER GFS MOS GUIDANCE FOR HI TEMPS. AS UPR LO TRACKS SLOWLY ACRS ONTARIO ON SAT NGT/SUN...NUMERICAL MODELS HINT AT THE PASSAGE OF ADDITIONAL SHRTWVS ON ITS SRN FLANK ACRS THE UPR GRT LKS. BUT TIMING OF THESE SHRTWVS IS PROBLEMATIC AT BEST. SINCE THERE IS LIKELY TO BE SOME DRYING IN THE WAKE OF THE SHRTWV RESPONSIBLE FOR THE SHRA CHCS ON SAT...CUT POPS ON SAT NGT TO TO SCHC TO TAKE INTO ACCOUNT LOSS OF DIURNAL HTG...EXCEPT IN THE EVNG OVER THE E DUE TO RESIDUAL IMPACT OF DEPARTING SHRTWV. THEN MAINTAINED GOING 30 POP ON SUN WITH DIURNAL HTG UNDER H5 THERMAL TROFFING AND APRCH OF ANOTHER SHRTWV. WITH CONVECTIVE TEMPS FCST A BIT HIER ON SUN...EXPECT MAX TEMPS A COUPLE OF DEGREES HIER THAN ON SAT. MAINTAINED LO CHC POPS SUN NGT/MON TO REFLECT DIGGING OF CUTOFF LO FM ONTARIO INTO THE UPR GRT LKS. EXPECT TEMPS FALLING BLO NORMAL AS LLVL COOL AIR NOW ON THE WRN FLANK OF THIS SYS FINALLY SURGES INTO THE FA. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... KSAW...SHOWERS HAVE NOW PUSHED EAST OF THE SITE AND WILL REMAIN EAST OF THE SITE THROUGH TOMORROW. THE ONLY CONCERN LEFT IS POTENTIAL FOR FOG. WINDS HAVE BEEN TURNING TO THE SOUTH OR EVEN SLIGHTLY WEST OF DUE SOUTH...WHICH IS NOT THAT FAVORABLE OF A WIND DIRECTION FOR FOG. PLUS THE WIND SPEEDS ARE UP AROUND 10 MPH. HOWEVER...DRYING ALOFT COMBINED WITH THE RECENT RAINFALL IS FAVORABLE. THEREFORE HAVE ONLY INCLUDED A TEMPO GROUP THROUGH 10Z OF IFR CIG/VIS POTENTIAL. VFR CONDITIONS WILL THEN CONTINUE THROUGH TOMORROW WITH DAYTIME CUMULUS AND GUSTY WINDS DEVELOPING. THE GUSTY WINDS ARE EXPECTED TO DIMINISH IN THE EVENING WITH THE LOSS OF HEATING. KCMX...ERLY FLOW KEPT SOME LOW CIG AND VIS THERE THIS PAST EVENING. HOWEVER...WINDS HAVE SWITCHED TO THE SE...WHICH IS NOT NEARLY AS FAVORABLE...AND AS A RESULT THE CIG AND VIS HAVE WENT MVFR. SINCE MODELS KEEP THE WINDS AT A SE OR EVEN SOUTH DIRECTION THROUGH THE NIGHT...HAVE ONLY WENT AS LOW AS IFR ON THE VIS AND MVFR ON THE CIG. VSBYS AND CIGS WILL IMPROVE LATE TONIGHT AS A COLD FRONT PASSES AND DRIER AIR WORKS IN. VFR CONDITIONS WILL THEN CONTINUE THROUGH TOMORROW WITH DAYTIME CUMULUS AND GUSTY WINDS DEVELOPING. THE GUSTY WINDS ARE EXPECTED TO DIMINISH IN THE EVENING WITH THE LOSS OF HEATING. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS CONTINUE TO DECREASE ACROSS LAKE SUPERIOR OVERNIGHT AS A COLD FRONT HAS BEEN MOVING SLOWLY ACROSS. WINDS NOW ACROSS LAKE SUPERIOR ARE BELOW 25 KNOTS...AND THIS WILL REMAIN THROUGH THE FORECAST PERIOD. ONLY ITEM OF INTEREST IS A COLD FRONT THAT PASSES SUNDAY NIGHT ASSOCIATED WITH LOW PRESSURE MOVING SE INTO SE CANADA. THE PRESSURE GRADIENT MAY BE TIGHT ENOUGH TO RESULT IN SOME 15 TO 25 KNOT NW WINDS ON EASTERN LAKE SUPERIOR ON MONDAY...AIDED BY COLD AIR FLOWING SOUTH ACROSS LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...KC AVIATION...VOSS/AJ MARINE...AJ
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
122 AM EDT FRI JUN 13 2008 .AVIATION... THERE IS SOME CONCERN FOR A BRIEF SHOWER OR THUNDERSTORM DURING THE EARLY MORNING HOURS DUE TO OVERHEAD DEVELOPMENT. WE CONTINUE TO EXPECT THE STORMS OVER NORTHERN LOWER AND CENTRAL LAKE MICHIGAN TO REMAIN TO OUR NORTH AND WEST. ANY ACTIVITY TO AFFECT SE MICHIGAN WILL DEVELOP OVERHEAD BUT COVERAGE IS EXPECTED TO BE TOO LOW TO INCLUDE IN THE FORECAST FOR ANY ONE AIRPORT. OUTSIDE OF THAT, A PERIOD OF MVFR VISIBILITY IN FOG/HAZE AROUND SUNRISE IS POSSIBLE BUT A BETTER CHANCE OF MVFR CONDITIONS WILL ARRIVE DURING THE AFTERNOON AND EVENING WITH PROSPECTS OF HEAVIER SHOWERS AND THUNDERSTORMS. SURFACE ANALYSIS AND MODEL FORECASTS INDICATE TOO MUCH GRADIENT FLOW FOR MUCH OF AN OBSTRUCTION BUT SOME LIGHT HAZE SHOULD BE TO BE EXPECTED AS SURFACE DEWPOINT APPROACHES 70F AROUND SUNRISE. && .PREV DISCUSSION...ISSUED 1027 PM EDT THU JUN 12 2008 UPDATE... WHILE THE STORMS TO OUR WEST AND NORTH ARE EXPECTED TO REMAIN THERE, OUTSIDE OF SOME DECAYING ACTIVITY LATE TONIGHT IN THE SAGINAW VALLEY, WE STILL EXPECT A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGHOUT OUR AREA DURING THE OVERNIGHT HOURS. THIS REMAINS THE CASE AS WARM AND HUMID AIR CONTINUES TO MAKE PROGRESS INTO SE MICHIGAN FROM INDIANA AND OHIO. THE 00Z DTX SOUNDING TELLS THE STORY AS IT SHOWS MODEST LOW LEVEL MOISTURE BELOW 800 MB WITH DRY AIR ABOVE. THIS DRY AIR INDICATES SOME POTENTIAL FOR COOLING DURING THE OVERNIGHT AND FURTHER DESTABILIZATION AS LOW LEVEL MOISTURE INCREASES ON INCREASING SOUTH FLOW. OUR GOING FORECAST HAS THIS HANDLED WELL WITH THE HIGHEST CHANCE OF RAIN OVERNIGHT IN THE SAGINAW VALLEY, TO ACCOUNT FOR ANY STORM REMNANTS FROM OUT WEST, AND LOWER CHANCES NEAR THE OHIO BORDER WHERE DEVELOPMENT OVERHEAD WILL HAVE LESS COVERAGE. PREV DISCUSSION...ISSUED 411 PM EDT THU JUN 12 2008 SHORT TERM...TONIGHT SURFACE WARM FRONT POSITIONED FROM A CHICAGO TO FINDLEY LINE WITH SOUTHEASTERLY BACKED FLOW...COMBINED WITH PLENTY OF HIGH CLOUD DEBRIS...KEEPING TEMPERATURES NEAR 80 IN MOST AREAS AS OF 3PM. WILL EXPECT INLAND AREAS FROM ADRIAN TO OWOSSO TO SEE A FEW MORE DEGREE CLIMB THIS EVENING AS WINDS BEGIN TO BACK TO THE SOUTH LATE...WHILE LOCATIONS CLOSER TO LAKE HURON WILL STRUGGLE TO CLIMB ABOVE 80. THE HIGHER DEWPOINTS HAVE ALSO BEEN SLOW TO ARRIVE... FINALLY CREEPING INTO THE MID 60S IN THE FAR SOUTH. AN 18Z TAMDAR SOUNDING OUT OF DTW SHOWS MOISTURE STARTING TO INCREASE ABOVE 800MB BUT ALSO SHOWS A CAP IN PLACE NEAR 925MB. WE WILL NEED TO SEE TEMPS/DEWPOINTS APPROACH 85/67 TO BREAK THROUGH THIS CAP FOR AN ISOLATED THUNDERSTORM THIS EVENING...WHICH ADRIAN IS APPROACHING. HAVE REMOVED THE ISOLATED THUNDERSTORMS WORDING IN THE NORTHERN AREAS BUT WILL CONTINUE TO CARRY AN ISOLATED THUNDERSTORMS FROM DETROIT SOUTH TO THE OHIO BORDER WHERE SURFACE BASED CAPES ARE AROUND 1500 J/KG. SPC MESO-ANALYSIS SHOWS ENHANCED 850MB MOISTURE OVER OHIO ALSO TRYING TO PUSH NORTH INTO THIS AREA WITH WEAK LOW LEVEL CONVERGENCE ALSO IN PLACE. UPSTREAM SHOWERS AND THUNDERSTORMS DEVELOPING OVER ILLINOIS/WISCONSIN WILL CONTINUE TO TRACK NORTHEAST TOWARDS THE UPPER PENINSULA AS UPPER TROUGH OVER THE PLAINS PUSHES EASTWARD WITH DEEP SOUTH SOUTHWESTERLY FLOW. ADDITIONAL AND POTENTIALLY STRONG THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER ILLINOIS AND TRACK INTO WESTERN LOWER OVERNIGHT AS 45+ KNOT LOW LEVEL JET NOSES INTO THIS AREA. WILL EXPECT THIS ACTIVITY TO BE WEAKENING AS IT APPROACHES THE TRI-CITIES LATE TONIGHT REACHING THE WARMER MID-LEVELS UNDERNEATH THE STRONG UPPER RIDGE. HOWEVER IF THIS CONVECTION CAN REMAIN ORGANIZED...AN ISOLATED SEVERE STORM IS NOT OUT OF THE QUESTION. WILL INCREASE POPS TO 60 PERCENT IN THIS AREA AFTER 6 AM WHILE JUST CARRYING A CHANCE OF SHOWERS AND THUNDERSTORMS AFTER MIDNIGHT ELSEWHERE. LONG TERM...FRIDAY THROUGH THURSDAY FRIDAY/FRIDAY NIGHT IS SHAPING UP TO BE AN INTERESTING TIME FRAME AS A 100+ KNOT JET LIFTS NORTH/NORTHEAST UP THE FRONT SIDE OF THE LARGE UPPER TROUGH OVER THE CENTRAL NOAM INTO THE UPPER MIDWEST/WESTERN GREAT LAKES. BY LATE IN THE DAY...LIFT WITHIN THE RIGHT ENTRANCE REGION OF THIS JET WILL BE SPREADING EAST INTO LAKE MICHIGAN/WESTERN LOWER MICHIGAN ON SOUTH INTO ILLINOIS/INDIANA. WITH THIS UPPER LEVEL SUPPORT...WOULD EXPECT SHOWERS/THUNDERSTORMS TO ERUPT FROM SOUTHWEST LOWER MICHIGAN INTO ILLINOIS/INDIANA AND THEN SPREAD NORTHEAST INTO THE AREA DURING THE LATE AFTERNOON/EVENING HOURS AS THE ASSOCIATED SURFACE FRONTAL BOUNDARY PUSHES INTO THE REGION. THIS PART OF THE SCENARIO...TIMING THE LARGE SCALE LIFT/FORCING...IS THE EASY PART. THE COMPLICATING FACTOR FOR THIS FORECAST WILL BE ANY RESIDUAL ACTIVITY FROM OVERNIGHT SHOWERS/THUNDERSTORMS THAT PERSISTS INTO THE MORNING HOURS...AND WHAT THIS MAY DO TO LIMIT INSTABILITY. AS IT IS...WOULD EXPECT THE AIRMASS THAT ADVECTS INTO THE REGION ON STRENGTHENING SOUTH/SOUTHWEST FLOW TO SUPPORT MLCAPES NEAR 2000 J/KG SO LONG AS EXTENSIVE CONVECTIVE DEBRIS DOES NOT LINGER INTO THE MID AFTERNOON. WITH MID LEVEL FLOW IN THE 40-50 KNOT RANGE...SOME STORMS WILL LIKELY BECOME SEVERE...AND GIVEN ONLY SLIGHT DIRECTIONAL CHANGE IN THE SOUTHWESTERLY WIND FIELD...THE MAIN HAZARD WOULD BE DAMAGING WINDS. AT A MINIMUM...WILL BE LEAVING LIKELY POPS (60-70%) IN THE FORECAST FOR THE AREA...AND WILL MOST LIKELY PROBABLY ATTEMPT TO DEFINE AN AREA OF EVEN GREATER CHANCE (80%)...AS THE CHANCE OF RAIN SEEMS QUITE GOOD. WILL JUST HAVE TO MONITOR OVERNIGHT CONVECTION TO BETTER ASSESS SEVERE POTENTIAL. THIS WHOLE SYSTEM WILL THEN PROGRESS TO THE EAST OVERNIGHT FRIDAY NIGHT...WITH DRY WEATHER EXPECTED ON SATURDAY/SATURDAY NIGHT AS A RIDGE OF HIGH PRESSURE BUILDS EAST THROUGH THE AREA. DURING THIS TIME FRAME...THE CENTRAL NOAM UPPER TROUGH BECOMES CENTERED OVER CANADA WITH A BROAD...NEARLY ZONAL FLOW OVER THE NORTHERN TIER OF STATES. SEVERAL DISTURBANCES WILL PROGRESS THROUGH THE AREA WITHIN THIS FLOW REGIME...MAINLY IN THE SUNDAY/SUNDAY NIGHT TIME FRAME. THIS WILL BRING ANOTHER CHANCE OF SHOWERS/THUNDERSTORMS...WHICH COULD LINGER INTO MONDAY. DID ADJUST THE FORECAST SLIGHTLY FOR TIMING...BUT KEPT POPS GOING IN THIS TIME FRAME. AFTER THESE DISTURBANCES PROGRESS OFF TO THE EAST...THE UPPER TROUGH WILL RECENTER OVER THE EASTERN CONUS...WITH NORTHWEST FLOW BECOMING ESTABLISHED. A LARGE HIGH PRESSURE SETTLES INTO THE CENTRAL PART OF THE NATION...BRINGING QUIET WEATHER FOR THE REST OF THE FORECAST. TEMPERATURES WILL ALSO BE COOLER WITH HIGHS IN THE UPPER 60S TO 70S AND LOWS GENERALLY IN THE 50S. HUMIDITY LEVELS WILL ALSO BE RATHER PLEASANT AS THE FLOW OUT OF CANADA PERSIST INTO LATE NEXT WEEK. MARINE... A PREDOMINANT SOUTHEAST WIND WILL CONTINUE ACROSS ALL MARINE AREAS INTO THIS EVENING...WITH GUSTS OF 20 TO 25 KNOTS ON LAKE HURON. THIS PERSISTENT ONSHORE FLOW WILL RESULT IN HIGHER WAVES AND AN INCREASED THREAT OF RIP CURRENTS TONIGHT...BEFORE THE FLOW BECOMES SOUTH LATE TONIGHT INTO FRIDAY. WILL LEAVE CURRENT HEADLINES THIS EVENING AND OVERNIGHT IN PLACE FOR LAKE HURON...BUT CANCEL THEM OVER LAKE ST CLAIR AND WESTERN LAKE ERIE WHERE WINDS ARE STARTING TO SUBSIDE AS WE STABILIZE. ALTHOUGH THERE WILL BE A CHANCE OF THUNDERSTORMS TONIGHT...A GREATER THREAT FOR STORMS EXISTS ON FRIDAY INTO FRIDAY NIGHT AS A COLD FRONT SWEEPS ACROSS LOWER MICHIGAN. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON... SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT HURON...UNTIL 6 AM FRIDAY. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....BT UPDATE.......BT SHORT TERM...KEC LONG TERM....DG MARINE.......DG YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
752 AM EDT FRI JUN 13 2008 UPDATED AVIATION DISCUSSION FOR 12Z TAF ISSUANCE. .DISCUSSION... 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR LO NEAR THE ND/CNDN BORDER DRIFTING SLOWLY EWD BTWN RDG OVER THE PAC NW AND HI AMPLITUDE RDG STRETCHING FM HUDSON BAY TO THE SE STATES. SURGE OF MSTR AHD OF THIS TROF WITH 02Z TAMDAR SDNG FM SAW SHOWING 190/50KT WIND AT H910 AND PWAT AS HI AS 2 INCHES AT DVN HAS FUELED RIBBON OF SHRA/TSRA THAT IS NOW IMPACTING THE SE PART OF THE FA. ALTHOUGH UPR LO AND ATTENDANT SFC COLD FNT REMAINS TO THE W IN MN...ARRIVAL OF DRIER AIR SHOWN ON THE 00Z MPX SDNG IN THE SW FLOW ALF AHEAD OF THE SFC FNT HAS CAUSED THE PCPN OVER THE W HALF OF THE FA TO DIMINISH TO JUST ISOLD -SHRA. WHERE DRYING ALF HAS OCCURRED OVER THE W...SOME PLACES ARE REPORTING VSBY AS LO AS 1/4SM IN FG. CLOSER TO THE SFC COLD FNT/UPR LO (WHERE H5 TEMPS ARE AOB -20C AS FAR E AS INL)...SOME SHRA/TSRA ARE IMPACTING NCNTRL MN. MUCH COLDER LLVL AIR IS NOTED TO THE W OF THE UPR LO POSITIONS WITH 00Z H85 TEMPS 5C AT BIS/GGW. MAIN FCST CONCERNS THIS PACKAGE INVOLVE SHRA/TSRA CHCS WITH SHRTWVS ROTATING ARND UPR LO NOW IN THE NRN PLAINS THAT IS FCST TO DRIFT SLOWLY EWD THE NEXT COUPLE OF DAYS. FOR TDAY...NAM/GFS SHOW UPR LO DRIFTING NEWD INTO NW ONTARIO THRU 00Z SAT. WSW FLOW ON THE SE FLANK OF THIS SYS LOOKS TO ADVECT VERY DRY AIRMASS SHOWN ON THE 00Z MPX RAOB. THIS MOTION OF THE UPR LO WL ALSO RESTRICT THE TEMP DROP ALF...WITH CORE OF -20C AIR AT H5 REMAINING WELL TO THE NW. IN FACT...NAM/GFS FCST SDNGS SHOW FAIRLY IMPRESSIVE MID LVL CAPPING DVLPG ABV H7-6 AND LIMITING DEPTH OF ANY UPDRAFTS ABV RELATIVELY HI LCL NR H85. SO...EVEN THOUGH SFC COLD FNT WL DRIFT INTO THE WRN ZNS THIS AFTN...THINK CHCS OF CNVCTN ALG THIS BNDRY WL BE QUITE A BIT LESS THAN OBSVD IN MN YDAY AFTN/EVNG. CONSIDERING THE STRENGTH OF THE CAP/LO EQUILIBRIUM LVL WITH ENVIRONMENTAL TEMP ABV -10C AT THAT LVL...REMOVED MENTION OF TS AND JUST MENTIONED ISOLD -SHRA WITH 00Z SAT FCST KINX AT IWD ONLY ARND 20. OTRW...ANY MRNG FOG/ST WL DSPT QUICKLY WITH ARRIVAL OF DRY AIR/ DIURNAL HTG/MIXING. AS FOR TEMPS...WL TEND TO BUMP UP FCST MAX TEMPS THIS AFTN CONSIDERING UPSTREAM REPORTS IN THE UPR 70S OVER SRN MN YDAY AND MIXING TO H75 OVER THE CNTRL ZNS ON GFS/NAM FCST SDNGS. EXPECT LOWER HI TEMPS DOWNWIND OF LK MI AND OVER THE W. AS UPR LO OVER NW ONTARIO DRIFTS OFF TO THE NE TNGT...A SHRTWV ROTATING ARND THIS FEATURE IS FCST TO PUSH INTO THE MN ARROWHEAD BY 12Z SAT. IN THE ABSENCE OF DIURNAL HTG AND UNDER DRY/STABLE AIRMASS ALF...MOST OF THE NGT WL BE QUIET AHD OF THIS NEXT FEATURE. ANY ISOLD -SHRA OVER THE W THIS AFTN WL END QUICKLY WITH LOSS OF DIURNAL HTG...PROBABLY BY 00Z. INTRODUCED SLGT CHC POPS LATE OVER WRN LK SUP TO ACCOUNT FOR INCOMING H5 THERMAL TROFFING/WEAKENING OF MID LVL CAP/MID LVL MOISTENING AHD OF APRCHG SHRTWV IN MN. COMBINATION OF INCOMING SHRTWV/DIURNAL HTG WL RESULT IN SCT SHRA/ TSRA ON SAT AS H5 THERMAL TROF (TEMPS AS LO AS -18C) SWINGS OVHD WITH SHRTWV AND CONVECTIVE TEMPS ARE FCST IN THE MID 60S. SINCE THE ARRIVAL OF THE SHRTWV WL BE BEST IN SYNC WITH THE SOLAR HTG CYCLE OVER THE CNTRL AND E...WL PAINT A BIT HIER CHC POPS THERE... ESPECIALLY OVER THE INTERIOR WHERE BREEZE OFF LK MI MIGHT ENHANCE LLVL CNVGC A BIT. DESPITE ARRIVAL OF H5 THERMAL TROFFING...GFS/NAM FCST SDNGS SHOW ONLY MODEST MID LVL LAPSE RATES...SO THREAT OF SVR TS SHOULD BE MINIMAL DESPITE RATHER IMPRESSIVE 0-6KM BULK SHEAR FCST IN THE 40 KT RANGE. LO WBZ FCST ARND 8.5K FT WOULD SUPPORT MORE LIKE PEA SIZED HAIL UNDER THE STRONGER CNVCTN. WITH CONVECTIVE TEMPS SO LO AND MORE CLD ARND... HI TEMPS WL BE QUITE A BIT LOWER THAN TDAY. PREFER TO TEND TOWARD THE LOWER GFS MOS GUIDANCE FOR HI TEMPS. AS UPR LO TRACKS SLOWLY ACRS ONTARIO ON SAT NGT/SUN...NUMERICAL MODELS HINT AT THE PASSAGE OF ADDITIONAL SHRTWVS ON ITS SRN FLANK ACRS THE UPR GRT LKS. BUT TIMING OF THESE SHRTWVS IS PROBLEMATIC AT BEST. SINCE THERE IS LIKELY TO BE SOME DRYING IN THE WAKE OF THE SHRTWV RESPONSIBLE FOR THE SHRA CHCS ON SAT...CUT POPS ON SAT NGT TO TO SCHC TO TAKE INTO ACCOUNT LOSS OF DIURNAL HTG...EXCEPT IN THE EVNG OVER THE E DUE TO RESIDUAL IMPACT OF DEPARTING SHRTWV. THEN MAINTAINED GOING 30 POP ON SUN WITH DIURNAL HTG UNDER H5 THERMAL TROFFING AND APRCH OF ANOTHER SHRTWV. WITH CONVECTIVE TEMPS FCST A BIT HIER ON SUN...EXPECT MAX TEMPS A COUPLE OF DEGREES HIER THAN ON SAT. MAINTAINED LO CHC POPS SUN NGT/MON TO REFLECT DIGGING OF CUTOFF LO FM ONTARIO INTO THE UPR GRT LKS. EXPECT TEMPS FALLING BLO NORMAL AS LLVL COOL AIR NOW ON THE WRN FLANK OF THIS SYS FINALLY SURGES INTO THE FA. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... WITH THE BEGINNING OF DAYTIME HEATING AND STRONGER SOUTHERLY WINDS...VSBYS HAVE BEEN IMPROVING AT BOTH TAF SITES. CIGS REMAIN LOW...AT LIFR OR VLIFR...BUT WITH CONTINUED DAYTIME HEATING...THESE SHOULD JUMP TO VFR IN ABOUT 2 HOURS. VFR CONDITIONS ARE THEN EXPECTED TO PERSIST THROUGH THE REST OF THE FORECAST...WITH GUSTY WINDS TODAY AS DAYTIME HEATING MIXES DOWN HIGHER WINDS ALOFT. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS CONTINUE TO DECREASE ACROSS LAKE SUPERIOR OVERNIGHT AS A COLD FRONT HAS BEEN MOVING SLOWLY ACROSS. WINDS NOW ACROSS LAKE SUPERIOR ARE BELOW 25 KNOTS...AND THIS WILL REMAIN THROUGH THE FORECAST PERIOD. ONLY ITEM OF INTEREST IS A COLD FRONT THAT PASSES SUNDAY NIGHT ASSOCIATED WITH LOW PRESSURE MOVING SE INTO SE CANADA. THE PRESSURE GRADIENT MAY BE TIGHT ENOUGH TO RESULT IN SOME 15 TO 25 KNOT NW WINDS ON EASTERN LAKE SUPERIOR ON MONDAY...AIDED BY COLD AIR FLOWING SOUTH ACROSS LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...KC AVIATION...AJ MARINE...AJ