Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/02/14


AREA FORECAST DISCUSSION
NWS PUEBLO CO
614 PM MDT MON SEP 1 2014 .UPDATE... ISSUED AT 558 PM MDT MON SEP 1 2014 UPDATED TO PULL POPS ACROSS THE PLAINS THIS EVENING BASED ON RADAR AND RECENT HI-RES MODEL DATA. MOISTURE AND LOW CLOUDS MAY BE POSSIBLE OVER THE FAR SOUTHEAST PLAINS LATE TONIGHT INTO TUESDAY MORNING...BUT NO PRECIP IS EXPECTED AT THIS TIME. MOZLEY && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 240 PM MDT MON SEP 1 2014 MAIN NEAR/SHORT-TERM METEOROLOGICAL ISSUES ARE TEMPERATURES...LOCALIZED GUSTY WINDS AT TIMES AND LOCALIZED LOW- GRADE POPS. CWFA EXPERIENCING NEAR SEASONAL SEPTEMBER AFTERNOON TEMPERATURES IN COMBINATION WITH GENERALLY SUNNY SKIES...ALTHOUGH SOME VARIABLE CLOUDS NOTED OVER PRIMARILY HIGHER TERRAIN LOCATIONS. IN ADDITION...WIND GUSTS EXCEEDING 30 MPH AT TIMES HAVE BEEN OBSERVED OVER THE MOUNTAINS OF CHAFFEE COUNTY. RECENT RADAR RETURNS INDICATE SHOWERS AND THUNDERSTORMS NEARING FAR NORTHEASTERN COLORADO...WELL NORTH OF OUR CWFA. LATEST COMPUTER SIMULATIONS...REAL-TIME DATA AND FORECAST MODEL SOUNDINGS INDICATE THAT GENERALLY DRY CONDITIONS SHOULD CONTINUE OVER THE MAJORITY OF THE FORECAST DISTRICT FROM LATE THIS AFTERNOON INTO TUESDAY AFTERNOON...ALTHOUGH RECENT HRRR MODEL DATA SUGGESTS THAT SHOWERS AND THUNDERSTORMS MAY THREATEN PORTIONS OF NORTHERN EL PASO AND KIOWA COUNTIES AS WELL AS SECTIONS OF LAS ANIMAS AND BACA COUNTIES FROM LATER THIS AFTERNOON INTO THIS EVENING. FOR TUESDAY...THE HIGHEST PROBABILITY OF ISOLATED SHOWER AND THUNDERSTORM ACTIVITY SHOULD BE NOTED OVER WESTERN HIGHER TERRAIN LOCATIONS...PRIMARILY DURING THE AFTERNOON AND EVENING HOURS. GUSTY...PRIMARILY HIGHER TERRAIN WINDS ARE ALSO ANTICIPATED AT TIMES FROM LATER THIS AFTERNOON INTO TUESDAY WHILE ABOVE SEASONAL EARLY SEPTEMBER AFTERNOON TEMPERATURES ARE PROJECTED TUESDAY. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 240 PM MDT MON SEP 1 2014 ...HOT WITH LOW THUNDERSTORM CHANCES THROUGH EARLY THURSDAY THEN COOLER WITH INCREASING THUNDERSTORM CHANCES... TUESDAY EVENING INTO EARLY THURSDAY...THE AIR MASS OVER THE REGION WILL BE QUITE WARM AND THE THUNDERSTORM CHANCES WILL BE LOW. COULD BE SOME SPOTTY DRY THUNDERSTORMS AROUND TUESDAY EVENING...MAINLY OVER THE MOUNTAINS. THEN...WEDNESDAY AFTERNOON...COULD BE SOME SPOTTY DRY LINE ACTIVITY ACROSS THE FAR SOUTHEAST PLAINS. MODELS HAVE BEEN BACK AND FORTH ON THIS SO CONFIDENCE IS A LITTLE LOW BUT THE POSSIBILITY REMAINS ALIVE. ON THURSDAY...THINGS START TO TRANSITION TO A COOLER...WETTER PATTERN. MODELS HAVE BEEN PRETTY CONSISTENT ON THIS SO CONFIDENCE IS INCREASING. IT STARTS WITH THE ARRIVAL OF A COLD FRONT THROUGH THE EASTERN PLAINS THURSDAY AFTERNOON. THE FRONT PUSHES INTO THE REGION AS THE RESULT OF AN UPPER DISTURBANCE MOVING THROUGH THE NORTHERN ROCKIES AND PLAINS. AS THE FRONT MOVES IN...MOIST UPSLOPE WINDS BEHIND THE FRONT GRADUALLY FIRE THUNDERSTORMS OVER AND NEAR THE MOUNTAINS IN THE AFTERNOON...SOME OF WHICH WORK EAST ACROSS THE PLAINS BY LATE IN THE DAY. WITH ADDED MOISTURE IN THE AIR AND UPSLOPE WINDS...THE THREAT FOR STRONG STORMS WILL INCREASE THIS DAY. FRIDAY THROUGH MONDAY...WE COULD BE DEALING WITH SOME RICH SUBTROPICAL MOISTURE AT TIMES...JUST DEPENDING ON HOW THINGS TRACK OVER THE NEXT FEW DAYS. RIGHT NOW...INDICATIONS ARE THAT FRIDAY AND SATURDAY COULD BOTH BE PRETTY WET OVER THE REGION WITH CONCERNS OF FLASH FLOODING. SUNDAY AND MONDAY STILL LOOK PRETTY WET FOR THE MOUNTAINS...BUT THE PLAINS LOOK MORE STABLE WITH LESS ACTIVITY. ALL OF THIS IS STILL SEVERAL DAYS AWAY AND HIGHLY SUBJECT TO CHANGE...HOWEVER. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 240 PM MDT MON SEP 1 2014 VFR CONDITIONS ARE ANTICIPATED AT THE KALS...KCOS AND KPUB TAF SITES THROUGH TUESDAY AFTERNOON. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MOZLEY SHORT TERM...77 LONG TERM...LW AVIATION...LW
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
944 AM MDT SUN AUG 31 2014 .UPDATE... ISSUED AT 924 AM MDT SUN AUG 31 2014 WATER VAPOR IMAGERY SHOWING STRONG UPPER TROF AXIS MOVING THROUGH SOUTHWEST WYOMING THIS MORNING. AHEAD OF THE TROF SCATTERED SHOWERS AND A FEW THUNDERSTORMS CONTINUE TO MOVE EAST ACROSS NORTHERN PORTIONS OF CWA AND ACROSS THE MOUNTAINS. LATEST RAP SHOWING MODEST QG ASCENT OVER NORTHERN COLORADO WITH THE TROF AND THIS WILL CONTINUE THROUGH THE AFTERNOON. INITIAL COLD FRONT HAS MOVED THROUGH MUCH OF NORTHEAST COLORADO AS WINDS HAVE SHIFTED NORTHEAST WHILE MAINTAINING DEWPOINTS IN THE UPPER 40S TO MID 50S. MAIN CHANGE TO ZONES WAS TO INCREASE CHANCES OF SHOWERS/STORMS THIS MORNING AND AFTERNOON OVER THE MOUNTAINS AND FAR NORTHERN PLAINS. WOULD NOT BE SURPRISED TO SEE A FEW SEVERE STORMS OVER THE NORTHEAST PLAINS GIVEN MODERATE ASCENT WITH JET STREAK AND AMPLE LOW LEVEL MOISTURE. FORECAST SOUNDINGS INDICATE 1000-1500J/KG OF CAPE POSSIBLE ESPECIALLY OVER THE PLAINS. WINDS TO 70 MPH AND SMALL HAIL WOULD BE THE MAIN THREAT GIVEN THE STRONG MID LEVEL FLOW OF 50KT AT 500MB. && .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 205 AM MDT SUN AUG 31 2014 TROUGH AND COLD FRONT WILL MOVE ACROSS COLORADO TODAY. DECENT BAND OF SHOWERS WITH A SHARP WIND SHIFT MOVING INTO THE NORTHERN MOUNTAINS NOW...THIS SHOWER BAND HAS HAD 40 MPH WINDS WITH IT ACROSS SOUTHERN WYOMING...PROBABLY NOT AS STRONG FURTHER SOUTH BUT EXPECT SOME WEST TO SOUTHWEST WIND WITH IT AS IT MOVES ACROSS THIS MORNING. THERE SHOULD BE ADDITIONAL SHOWER BANDS MUCH OF THE DAY OVER THE MOUNTAINS...WHILE WEST WINDS WILL LIMIT PRECIPITATION EAST OF THE FRONT RANGE THROUGH MIDDAY. WIND SHIFT TO A MORE NORTHERLY DIRECTION AND THE TROUGH AXIS COME THIS AFTERNOON AND THAT WOULD BE THE BEST CHANCE OF STORMS EAST OF THE MOUNTAINS. BY SUNSET THE TROUGH SHOULD BE EAST OF THE STATE AND THE SHOWERS SHOULD BE EXITING. CAPES WILL BE VERY LOW SO ONLY EXPECTING THE WIND WITH THE SHOWERS OVER MOST OF THE AREA TODAY. GENERALLY EXPECTING GUSTS IN THE 30-40 MPH RANGE THOUGH THERE IS POTENTIAL FOR NEAR SEVERE GUSTS IN ORGANIZED LINES...NOT EXPECTING THAT MUCH PRECIP THOUGH SO A LOW THREAT. NEAR THE EASTERN BORDER CONVECTION MAY BE A BIT STRONGER WITH BETTER MOISTURE...AGAIN MAINLY A WIND THREAT BUT MORE OF A CHANCE OUT THERE. WITH THE CLOUD COVER AND SOME COLD ADVECTION THIS AFTERNOON HIGHS WILL BE LOWER...CURRENT FORECAST LOOKS GOOD. I LOWERED TEMPS A LITTLE TONIGHT WITH CLEARING...DRIER AIR...AND DIMINISHING WINDS IN MOST AREAS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 205 AM MDT SUN AUG 31 2014 STRONG WEST-NORTHWESTERLY FLOW ALOFT IS PROGGED OVER THE CWA MONDAY WITH THE UPPER TROUGH AXIS EAST OF COLORADO. THE JET LEVEL FLOW DECREASES AND BECOMES ZONAL MONDAY NIGHT THROUGH TUESDAY NIGHT. DOWNWARD SYNOPTIC SCALE ENERGY IS PROGGED OVER THE FORECAST AREA ON MONDAY...WEAKER...BUT STILL DOWNWARD MONDAY NIGHT THROUGH TUESDAY NIGHT. THE LOW LEVEL WINDS LOOK TO BE WEAK UPSLOPE MONDAY INTO MONDAY EVENING...THEN NORMAL DIURNAL PATTERNS TAKE OVER. THE PLAINS HAVE FAIRLY STRONG SOUTHERLY WINDS PROGGED ON TUESDAY. MOISTURE IS NOT GREAT THROUGH THE PERIODS...BUT THERE IS SOME PROGGED AT THE LOWER LEVELS OF THE PLAINS. THE PRECIPITABLE WATER VALUES ARE GENERALLY FROM THE 0.30 TO 0.80 INCH RANGE THROUGHOUT. THE BOUNDARY LAYER DEW POINT READINGS RANGE FROM THE 20S F WEST TO LOWER 50S F EAST THROUGH THE PERIODS. THERE IS TINY BIT OF CAPE PROGGED OVER THE PLAINS MONDAY AFTERNOON...WITH CONSIDERABLY MORE PROGGED MAINLY FOR THE PLAINS ON TUESDAY AND TUESDAY EVENING. CONCERNING MEASURABLE RAINFALL ON THE QPF FIELDS...THERE ARE TINY AMOUNTS PROGGED HERE AND THERE NOW AND THEN FROM THE VARIOUS MODELS MONDAY THROUGH TUESDAY NIGHT...BUT IT IS VERY INSIGNIFICANT. FOR POPS...WILL GO WITH 0-10%S THROUGH THE PERIODS. FOR TEMPERATURES...MONDAY`S HIGHS ARE 1-3 C COLDER THAN TODAY`S EXPECTED READINGS. TUESDAY`S HIGHS ARE 2-5 C WARMER THAN MONDAY`S. FOR THE LATER DAYS...WEDNESDAY THROUGH SATURDAY...THE MODELS HAVE THE UPPER RIDGE CENTERED IMMEDIATELY SOUTH-SOUTHEAST OF COLORADO ALL FOUR DAYS. THE FLOW ALOFT IS WEST-SOUTHWESTERLY ALL FOUR DAYS. MOISTURE INCREASES A BIT THURSDAY INTO NEXT WEEKEND. MODELS ALSO SHOW UPSLOPE EAST OF THE DIVIDE FROM LATER THURSDAY THROUGH SATURDAY. && .AVIATION...(FOR THE TAFS THROUGH 18Z MONDAY MORNING) ISSUED AT 924 AM MDT SUN AUG 31 2014 STILL SOME UNCERTAINTY ON HOW MUCH CONVECTION WILL SURVIVE ACROSS THE LOCAL TERMINALS AS UPPER TROF MOVES ACROSS THE REGION THIS AFTERNOON. INITIALLY...WE HAVE SOME UPSLOPE FLOW AS LOW LEVEL MOISTURE REMAINS HIGH. HOWEVER AS BANDS OF SHOWERS MOVE OFF THE MOUNTAINS THERE WILL BE MORE DOWNSLOPE WINDS DEVELOPING FROM THE NORTHWEST. THIS WILL DRY THINGS OUT WITH LESSER CHANCES OF THUNDERSTORMS. WILL MAINTAIN TEMPO GROUPS FOR THE HIGHER WINDS AS THE MAIN THREAT. RAPID CLEARING BEHIND THE TROF EARLY THIS EVENING WITH CLEARING SKIES. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ENTREKIN SHORT TERM...GIMMESTAD LONG TERM...RJK AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS ALBANY NY
224 AM EDT SUN AUG 31 2014 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS TODAY...SOME POSSIBLY WITH HEAVY RAINFALL. WEAK HIGH PRESSURE WILL BUILD IN LABOR DAY. IT WILL BE VERY WARM AND HUMID AND MAINLY RAIN-FREE...BUT AN ADDITIONAL THUNDERSTORM CANNOT BE RULED OUT. ANOTHER COLD FRONT IS EXPECTED TO BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS TUESDAY AND TUESDAY NIGHT. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1245 AM EDT...RADAR INDICATED THAT SHOWERS AND THUNDERSTORMS WERE STILL HAVING A DIFFICULT TIME MAKING INTO HERKIMER COUNTY...AS THEY WERE MAINLY TRACKING TO THE NORTHWEST OF NORTHERN HERKIMER COUNTY...ALONG THE TUG HILL PLATEAU. BOTH THE LATEST RUC13 AND HRRR NOW KEEP MOST OF THE ACTIVITY CONFINED TO OUR NORTHWEST AREAS OVERNIGHT SO WE DECIDED TO TRIM BACK THE POPS EVEN MORE COMPARED TO THE LAST UPDATE. THE IFR 11U-3.9U IFR SATELLITE PICTURES INDICATED STRATUS SLOWLY OVERSPREADING THE REGION FROM THE SOUTH...WHILE MID AND HIGH CLOUDS WERE WORKING IN FROM THE WEST. TEMPERATURES WERE STILL MILD...GENERALLY IN THE 60S THANKS TO THE INCREASING CLOUDS AND A PERSISTENT SOUTHERLY BREEZE. FOR THE REST OF THE OVERNIGHT...LOOK FOR SCATTERED SHOWERS AND PERHAPS A RUMBLE OF THUNDER (THE SHOWALTER INDICES WERE GENERALLY JUST ABOVE 0 SO MUCH INSTABILITY)...OVER MAINLY OUR PORTION OF THE ADIRONDACK PARK. EVERYONE ELSE SHOULD REMAIN DRY WITH INCREASING CLOUDS. NO CHANGES TO OVERNIGHT LOWS...LOOK FOR THEM TO ONLY DROP A POINT OR TWO MORE...GENERALLY STAYING IN THE 60S ALL NIGHT ALONG. THE SOUTHERLY BREEZE WILL PERSIST 5 TO 15 MPH. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/... STILL SOME QUESTION AS TO HOW MUCH CLOUD COVER WILL BE OVER THE REGION TOMORROW. SOUTHWEST BOUNDARY LAYER FLOW AND A LOOSENING BOUNDARY LAYER THERMAL GRADIENT SHOULD PROMOTE SOME BREAKS IN CLOUD COVER. THERE SHOULD ALSO BE BREAKS IN THE LEFTOVER CONVECTIVE DEBRIS FROM CONVECTION IN THE GREAT LAKES AND WESTERN NY/PA. CLOUD COVER CURRENTLY UPSTREAM IN THE OH VALLEY AND GREAT LAKES IS SCATTERED TO BROKEN. SO WITH THE PROSPECTS FOR AT LEAST SOME INTERVALS OF SUN...WITH RAPIDLY WARMING BOUNDARY LAYER TEMPERATURES...HIGHS SOLIDLY IN THE 80S SUNDAY...BUT UPPER 70S SOUTHERN ADIRONDACKS WHERE SHOWERS AND THUNDERSTORMS SHOULD AFFECT EARLIER IN THE DAY. UPPER DYNAMICS...ALONG WITH A LITTLE LOW LEVEL JET SEGMENT TRACKS THROUGH THE REGION SUNDAY AND SUNDAY NIGHT. DEEP MOISTURE SEEN IN THE SATELLITE DERIVED SOUNDER IMAGERY OF PWAT...IS SURGING NORTH FROM THE MS/TN VALLEY. SO...COVERAGE OF SHOWERS AND SCATTERED THUNDERSTORMS SHOULD INCREASE TO LIKELY IN THE AFTERNOON IN MOST AREAS. LOCALLY HEAVY RAIN IS POSSIBLE AND WILL ADDRESS IN HAZARDOUS WEATHER OUTLOOK...BUT NO WIDESPREAD OR HIGH IMPACT FLOOD THREAT EXPECTED. WEAK COLD FRONT EXITS SUNDAY NIGHT WITH JUST SOME LINGERING SCATTERED SHOWERS AND THUNDERSTORMS...WITH THE BEST COVERAGE IN THE MID HUDSON VALLEY...BERKSHIRES AND NW CT SUNDAY EVENING. SOME QUESTION AS TO HOW FAR SOUTH THE WEAK LOW LEVEL BOUNDARY GETS...SO SCATTERED SHOWERS AND THUNDERSTORMS COULD LINGER THROUGH MUCH OF MONDAY IN THE MID HUDSON VALLEY AND NW CT...BUT JUST SCATTERED... WITH ISOLATED AFTERNOON ACTIVITY ELSEWHERE. STILL...SOME PERIODS OF SUNSHINE EXPECTED MONDAY...WITH PERHAPS MORE CLOUDS THAN SUN IN THE MID HUDSON VALLEY AND NW CT. HIGHS MONDAY SOLIDLY IN THE 80S. THERE COULD BE A LULL IN THE SHOWER AND THUNDERSTORM ACTIVITY MONDAY NIGHT WITH PARTIAL CLEARING...BUT DEW POINTS ARE NOT EXPECTED TO DROP MUCH IF ANY...SO LOWS MONDAY NIGHT IN THE 60S. ANOTHER COLD FRONT APPROACHES TUESDAY...WITH A BIT BETTER BOUNDARY LAYER FRONTOGENESIS AND THERMAL GRADIENT TRACKING TOWARD THE REGION. CURRENT CONSENSUS ON TIMING SUGGESTS SOME SUNSHINE AND DAYTIME HEATING AT LEAST TUESDAY MORNING...WITH THE LEADING EDGE OF SCATTERED SHOWERS AND THUNDERSTORMS APPROACHING WESTERN AREAS MIDDAY OR EARLY AFTERNOON TUESDAY...THEN AFFECTING THE REST OF THE REGION THROUGH THE AFTERNOON. HIGHS TUESDAY SOLIDLY IN THE 80S. THUNDERSTORMS TUESDAY COULD BE STRONG BASED ON THE POTENTIAL INSTABILITY...THERMAL GRADIENT FORCING AND BOUNDARY LAYER WINDS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MIDWEEK THROUGH THE END OF THE WORK WEEK WILL FEATURE DRY CONDITIONS AS HIGH PRESSURE MOVES OVER THE FORECAST AREA BEHIND A COLD FRONT. HOWEVER...A COLD FRONT ON SATURDAY WILL BRING A SHOWERY START FOR THE BEGINNING OF THE WEEKEND. TEMPERATURES WILL AVERAGE A FEW DEGREES ABOVE NORMAL...WITH HIGHS FROM AROUND 70 DEGREES...TO THE LOWER AND MID 80S WEDNESDAY THROUGH FRIDAY. SATURDAY WILL BE COOLER WITH HIGHS FROM THE MID 60S TO AROUND 809 DEGREES. NIGHTTIME LOWS WILL BE IN THE MID 50S TO UPPER 60S RANGE JUST PRIOR TO THE COLD FRONT TUESDAY NIGHT. WEDNESDAY NIGHT LOWS WILL RANGE FROM AROUND 50 DEGREES IN THE WESTERN ADIRONDACKS...TO NEAR 60 DEGREES DOWN THE HUDSON VALLEY. THEN READINGS SLOWLY BOUNCE BACK... WITH LOWS FROM MAINLY THE LOWER AND MID 50S IN THE MOUNTAINS...TO THE LOWER 60S DOWN THE HUDSON VALLEY. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 200 AM...CIGS AT THE KGFL/KALB/KPOU TAF SITES ARE VERY CLOSE TO THE MVFR/VFR CUTOFF OF 3000 FEET...WITH KALB STILL ONLY SCT AT 3300 FEET. AT KPSF CIGS ARE AROUND 1500 FEET. EXPECT MAINLY MVFR CIGS AT ALL THE TAF SITES THROUGH AROUND 15Z...WITH OCCASIONAL IFR CIGS AT KPSF. AFTER 15Z CIGS SHOULD RISE TO MAINLY VFR AT KGFL/KALB/KPOU...AND MVFR AT KPSF. VCSH HAS BEEN INCLUDED AT ALL THE TAF SITES AFTER 15Z. THE MAIN BAND OF MOISTURE ASSOCIATED WITH THE FRONTAL BOUNDARY AND UPPER LEVEL TROF WILL MOVE ACROSS THE TAF SITES LATER SUNDAY AFTERNOON AND EVENING. HAVE FORECAST MVFR CIGS/VSBYS AT ALL THE TAFS SITES AFTER 19Z/20Z AS WIDESPREAD SHOWERS MOVE IN...WITH A PROB 30 GROUP GENERALLY BETWEEN 19Z AND 01Z FOR A CHANCE OF TSTMS WITH MVFR CONDITIONS. THE WIDESPREAD SHOWERS WILL LIKELY END BY AROUND 01Z/02Z AT THE TAF SITES...BUT EXPECT MVFR CIGS/VSBYS TO LINGER DUE TO FOG AND STRATUS STILL OVER THE REGION. WINDS WILL BE CALM OR SOUTH AT 8 KTS OR LESS THROUGH THE REST OF TONIGHT...THEN SOUTH OR SOUTHWEST AT 7 TO 10 KTS ON SUNDAY AND SUNDAY EVENING...BECOMING 5 KTS OR LESS AFTER 02Z SUNDAY NIGHT. OUTLOOK... LATE SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA. LABOR DAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA. MONDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA. TUESDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA. TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA. WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... LATE TONIGHT INTO SUNDAY A SLOW MOVING COLD FRONT WILL BRING A ROUND OF SHOWERS AND THUNDERSTORMS...SOME POSSIBLY WITH HEAVY RAINFALL. WEAK HIGH PRESSURE WILL BUILD IN LABOR DAY. IT WILL BE VERY WARM HUMID AND MAINLY RAIN-FREE...BUT AN ADDITIONAL THUNDERSTORM CANNOT BE RULED OUT. ANOTHER COLD FRONT IS EXPECTED TO BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS TUESDAY AND TUESDAY NIGHT. MINIMUM RH VALUES SHOULD BE BETWEEN 65 TO 75 PERCENT SUNDAY ASS COVERAGE OF SHOWERS AND THUNDERSTORMS INCREASES. MINIMUM RH VALUES MONDAY SHOULD BE 55 TO 65 PERCENT. MAXIMUM RH VALUES TONIGHT AND TOMORROW NIGHT ARE EXPECTED TO BE 80 TO 100 PERCENT WITH SOME DEW FORMATION. THE SURFACE WIND BE SOUTH TO SOUTHWEST AT 15 MPH OR LESS TONIGHT THROUGH SUNDAY NIGHT...THEN BECOME WEST TO SOUTHWEST MONDAY. && .HYDROLOGY... SHOWERS AND THUNDERSTORMS WILL DEVELOP LATE TONIGHT AND ESPECIALLY SUNDAY INTO SUNDAY EVENING. AVERAGE BASIN RAINFALLS LOOK TO GENERALLY BE UNDER AN INCH SO AT THIS POINT...MAIN STREAM RIVERS WILL GENERALLY SEE LITTLE OR NO RISES. HOWEVER...WITH PWAT VALUES FORECAST TO INCREASE TO 2 INCHES...ANY THUNDERSTORM COULD CONTAIN LOCALLY HEAVY RAINFALL EASILY EXCEEDING AN INCH. ANY TRAINING THUNDERSTORMS COULD RESULT LOCALIZED PONDING OF WATER IN AREAS OF POOR DRAINAGE. ADDITIONAL THUNDERSTORMS ON LABOR DAY LOOK ISOLATED AND GENERALLY NOT EXPECTED TO PRODUCE ADDITIONAL HYDRO PROBLEMS. MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE TUESDAY INTO WEDNESDAY AS A STRONGER COLD FRONT ARRIVES. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...SND/HWJIV/NAS NEAR TERM...HWJIV SHORT TERM...NAS LONG TERM...ELH AVIATION...GJM FIRE WEATHER...NAS HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1243 AM EDT SUN AUG 31 2014 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS TODAY...SOME POSSIBLY WITH HEAVY RAINFALL. WEAK HIGH PRESSURE WILL BUILD IN LABOR DAY. IT WILL BE VERY WARM AND HUMID AND MAINLY RAIN-FREE...BUT AN ADDITIONAL THUNDERSTORM CANNOT BE RULED OUT. ANOTHER COLD FRONT IS EXPECTED TO BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS TUESDAY AND TUESDAY NIGHT. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1245 AM EDT...RADAR INDICATED THAT SHOWERS AND THUNDERSTORMS WERE STILL HAVING A DIFFICULT TIME MAKING INTO HERKIMER COUNTY...AS THEY WERE MAINLY TRACKING TO THE NORTHWEST OF NORTHERN HERKIMER COUNTY...ALONG THE TUG HILL PLATEAU. BOTH THE LATEST RUC13 AND HRRR NOW KEEP MOST OF THE ACTIVITY CONFINED TO OUR NORTHWEST AREAS OVERNIGHT SO WE DECIDED TO TRIM BACK THE POPS EVEN MORE COMPARED TO THE LAST UPDATE. THE IFR 11U-3.9U IFR SATELLITE PICTURES INDICATED STRATUS SLOWLY OVERSPREADING THE REGION FROM THE SOUTH...WHILE MID AND HIGH CLOUDS WERE WORKING IN FROM THE WEST. TEMPERATURES WERE STILL MILD...GENERALLY IN THE 60S THANKS TO THE INCREASING CLOUDS AND A PERSISTENT SOUTHERLY BREEZE. FOR THE REST OF THE OVERNIGHT...LOOK FOR SCATTERED SHOWERS AND PERHAPS A RUMBLE OF THUNDER (THE SHOWALTER INDICES WERE GENERALLY JUST ABOVE 0 SO MUCH INSTABILITY)...OVER MAINLY OUR PORTION OF THE ADIRONDACK PARK. EVERYONE ELSE SHOULD REMAIN DRY WITH INCREASING CLOUDS. NO CHANGES TO OVERNIGHT LOWS...LOOK FOR THEM TO ONLY DROP A POINT OR TWO MORE...GENERALLY STAYING IN THE 60S ALL NIGHT ALONG. THE SOUTHERLY BREEZE WILL PERSIST 5 TO 15 MPH. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/... STILL SOME QUESTION AS TO HOW MUCH CLOUD COVER WILL BE OVER THE REGION TOMORROW. SOUTHWEST BOUNDARY LAYER FLOW AND A LOOSENING BOUNDARY LAYER THERMAL GRADIENT SHOULD PROMOTE SOME BREAKS IN CLOUD COVER. THERE SHOULD ALSO BE BREAKS IN THE LEFTOVER CONVECTIVE DEBRIS FROM CONVECTION IN THE GREAT LAKES AND WESTERN NY/PA. CLOUD COVER CURRENTLY UPSTREAM IN THE OH VALLEY AND GREAT LAKES IS SCATTERED TO BROKEN. SO WITH THE PROSPECTS FOR AT LEAST SOME INTERVALS OF SUN...WITH RAPIDLY WARMING BOUNDARY LAYER TEMPERATURES...HIGHS SOLIDLY IN THE 80S SUNDAY...BUT UPPER 70S SOUTHERN ADIRONDACKS WHERE SHOWERS AND THUNDERSTORMS SHOULD AFFECT EARLIER IN THE DAY. UPPER DYNAMICS...ALONG WITH A LITTLE LOW LEVEL JET SEGMENT TRACKS THROUGH THE REGION SUNDAY AND SUNDAY NIGHT. DEEP MOISTURE SEEN IN THE SATELLITE DERIVED SOUNDER IMAGERY OF PWAT...IS SURGING NORTH FROM THE MS/TN VALLEY. SO...COVERAGE OF SHOWERS AND SCATTERED THUNDERSTORMS SHOULD INCREASE TO LIKELY IN THE AFTERNOON IN MOST AREAS. LOCALLY HEAVY RAIN IS POSSIBLE AND WILL ADDRESS IN HAZARDOUS WEATHER OUTLOOK...BUT NO WIDESPREAD OR HIGH IMPACT FLOOD THREAT EXPECTED. WEAK COLD FRONT EXITS SUNDAY NIGHT WITH JUST SOME LINGERING SCATTERED SHOWERS AND THUNDERSTORMS...WITH THE BEST COVERAGE IN THE MID HUDSON VALLEY...BERKSHIRES AND NW CT SUNDAY EVENING. SOME QUESTION AS TO HOW FAR SOUTH THE WEAK LOW LEVEL BOUNDARY GETS...SO SCATTERED SHOWERS AND THUNDERSTORMS COULD LINGER THROUGH MUCH OF MONDAY IN THE MID HUDSON VALLEY AND NW CT...BUT JUST SCATTERED... WITH ISOLATED AFTERNOON ACTIVITY ELSEWHERE. STILL...SOME PERIODS OF SUNSHINE EXPECTED MONDAY...WITH PERHAPS MORE CLOUDS THAN SUN IN THE MID HUDSON VALLEY AND NW CT. HIGHS MONDAY SOLIDLY IN THE 80S. THERE COULD BE A LULL IN THE SHOWER AND THUNDERSTORM ACTIVITY MONDAY NIGHT WITH PARTIAL CLEARING...BUT DEW POINTS ARE NOT EXPECTED TO DROP MUCH IF ANY...SO LOWS MONDAY NIGHT IN THE 60S. ANOTHER COLD FRONT APPROACHES TUESDAY...WITH A BIT BETTER BOUNDARY LAYER FRONTOGENESIS AND THERMAL GRADIENT TRACKING TOWARD THE REGION. CURRENT CONSENSUS ON TIMING SUGGESTS SOME SUNSHINE AND DAYTIME HEATING AT LEAST TUESDAY MORNING...WITH THE LEADING EDGE OF SCATTERED SHOWERS AND THUNDERSTORMS APPROACHING WESTERN AREAS MIDDAY OR EARLY AFTERNOON TUESDAY...THEN AFFECTING THE REST OF THE REGION THROUGH THE AFTERNOON. HIGHS TUESDAY SOLIDLY IN THE 80S. THUNDERSTORMS TUESDAY COULD BE STRONG BASED ON THE POTENTIAL INSTABILITY...THERMAL GRADIENT FORCING AND BOUNDARY LAYER WINDS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MIDWEEK THROUGH THE END OF THE WORK WEEK WILL FEATURE DRY CONDITIONS AS HIGH PRESSURE MOVES OVER THE FORECAST AREA BEHIND A COLD FRONT. HOWEVER...A COLD FRONT ON SATURDAY WILL BRING A SHOWERY START FOR THE BEGINNING OF THE WEEKEND. TEMPERATURES WILL AVERAGE A FEW DEGREES ABOVE NORMAL...WITH HIGHS FROM AROUND 70 DEGREES...TO THE LOWER AND MID 80S WEDNESDAY THROUGH FRIDAY. SATURDAY WILL BE COOLER WITH HIGHS FROM THE MID 60S TO AROUND 809 DEGREES. NIGHTTIME LOWS WILL BE IN THE MID 50S TO UPPER 60S RANGE JUST PRIOR TO THE COLD FRONT TUESDAY NIGHT. WEDNESDAY NIGHT LOWS WILL RANGE FROM AROUND 50 DEGREES IN THE WESTERN ADIRONDACKS...TO NEAR 60 DEGREES DOWN THE HUDSON VALLEY. THEN READINGS SLOWLY BOUNCE BACK... WITH LOWS FROM MAINLY THE LOWER AND MID 50S IN THE MOUNTAINS...TO THE LOWER 60S DOWN THE HUDSON VALLEY. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... VFR CONDITIONS PREVAILING ACROSS THE TERMINALS THIS AFTERNOON...HOWEVER AN EXPANSIVE AREA OF STRATUS CLOUDS IS NOTICEABLY CREEPING TOWARDS THE AREA FROM PA/NJ INTO THE CATSKILLS OF NY...COURTESY OF LOW LEVEL MOISTURE INCREASING WITH A SOUTH TO SOUTHWEST FLOW. FOR NOW...MOST OF THE CIGS ARE IN VFR RANGE ALTHOUGH MVFR CIGS HAVE BEEN NOTED ACROSS SOME HIGHER TERRAIN AREAS. WILL MENTION SCT CLOUDS EARLY WITH CIGS DEVELOPING LATER THIS AFTERNOON OR EARLY EVENING...FROM SOUTHWEST TO NORTHEAST ACROSS THE AREA. CIGS EXPECTED TO LOWER TO MVFR RANGE THIS EVENING...ESPECIALLY LATER THIS EVENING AS LOW LEVEL DEWPOINTS CONTINUE TO RISE. OVERNIGHT MAINLY MVFR CONDITIONS EXPECTED WITH OVC CIGS AND SOME MIST. HOWEVER...THERE IS A CHANCE OF SOME OCCASIONAL IFR AT KPSF BUT CONFIDENCE NOT GREAT ENOUGH TO MENTION IN TAF AT THIS TIME. CIGS WILL ONLY SLOWLY RISE ON SUNDAY...BUT SHOULD STILL GENERALLY REMAIN IN MVFR RANGE THROUGH 18Z SUNDAY UNTIL LATER IN THE DAY. A COLD FRONT WILL APPROACH FROM THE WEST BRINGING A THREAT OF MAINLY AFTERNOON RAIN SHOWERS/THUNDERSTORMS. WILL MENTION VCSH IN KGFL/KALB TAF PRIOR TO 18Z. WINDS WILL BE SOUTHERLY AROUND 6-12 KT WITH SOME OCCASIONAL HIGHER GUSTS. WIND SPEEDS WILL DECREASE TO AROUND 3-8 KT AFTER DARK. WINDS WILL GENERALLY BE SOUTH-SOUTHWEST AROUND 5-10 KT ON SUNDAY. OUTLOOK... SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA. LABOR DAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA. MONDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA. TUESDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA. TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA. WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... LATE TONIGHT INTO SUNDAY A SLOW MOVING COLD FRONT WILL BRING A ROUND OF SHOWERS AND THUNDERSTORMS...SOME POSSIBLY WITH HEAVY RAINFALL. WEAK HIGH PRESSURE WILL BUILD IN LABOR DAY. IT WILL BE VERY WARM HUMID AND MAINLY RAIN-FREE...BUT AN ADDITIONAL THUNDERSTORM CANNOT BE RULED OUT. ANOTHER COLD FRONT IS EXPECTED TO BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS TUESDAY AND TUESDAY NIGHT. MINIMUM RH VALUES SHOULD BE BETWEEN 65 TO 75 PERCENT SUNDAY ASS COVERAGE OF SHOWERS AND THUNDERSTORMS INCREASES. MINIMUM RH VALUES MONDAY SHOULD BE 55 TO 65 PERCENT. MAXIMUM RH VALUES TONIGHT AND TOMORROW NIGHT ARE EXPECTED TO BE 80 TO 100 PERCENT WITH SOME DEW FORMATION. THE SURFACE WIND BE SOUTH TO SOUTHWEST AT 15 MPH OR LESS TONIGHT THROUGH SUNDAY NIGHT...THEN BECOME WEST TO SOUTHWEST MONDAY. && .HYDROLOGY... SHOWERS AND THUNDERSTORMS WILL DEVELOP LATE TONIGHT AND ESPECIALLY SUNDAY INTO SUNDAY EVENING. AVERAGE BASIN RAINFALLS LOOK TO GENERALLY BE UNDER AN INCH SO AT THIS POINT...MAIN STREAM RIVERS WILL GENERALLY SEE LITTLE OR NO RISES. HOWEVER...WITH PWAT VALUES FORECAST TO INCREASE TO 2 INCHES...ANY THUNDERSTORM COULD CONTAIN LOCALLY HEAVY RAINFALL EASILY EXCEEDING AN INCH. ANY TRAINING THUNDERSTORMS COULD RESULT LOCALIZED PONDING OF WATER IN AREAS OF POOR DRAINAGE. ADDITIONAL THUNDERSTORMS ON LABOR DAY LOOK ISOLATED AND GENERALLY NOT EXPECTED TO PRODUCE ADDITIONAL HYDRO PROBLEMS. MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE TUESDAY INTO WEDNESDAY AS A STRONGER COLD FRONT ARRIVES. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...SND/HWJIV/NAS NEAR TERM...HWJIV SHORT TERM...NAS LONG TERM...ELH AVIATION...JPV FIRE WEATHER...NAS HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
607 AM EDT SUN AUG 31 2014 .SYNOPSIS... HIGH PRESSURE WELL OFF THE EAST COAST WILL MAINTAIN A SOUTHWESTERLY FLOW OVER THE AREA THROUGH THE FIRST PART OF THE WEEK. A WEAK COLD FRONT IS THEN EXPECTED TO MOVE ACROSS OUR AREA TUESDAY NIGHT AND EARLY WEDNESDAY. HIGH PRESSURE WILL BUILD IN BEHIND THIS FRONT FOR THE SECOND HALF OF THE WEEK. ANOTHER COLD FRONT MAY APPROACH FROM THE WEST NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... OUR REGION WILL MAINLY BE CAUGHT BETWEEN SYSTEMS TODAY, AS AN UPPER-LEVEL RIDGE REMAINS SITUATED TO OUR SOUTH AND SOUTHEAST WITH SURFACE HIGH PRESSURE TO THE EAST. MEANWHILE, AN UPPER-LEVEL TROUGH WILL CONTINUE TO TRACK ACROSS THE GREAT LAKES THEN ACROSS SOUTHERN ONTARIO CANADA. THIS WILL RESULT IN A DEEP SOUTHWESTERLY FLOW, WHICH WILL PULL AN ABUNDANCE OF MOISTURE INTO OUR REGION. AS A RESULT, A MORE HUMID DAY IS EXPECTED. THE PRESENCE OF SOME WAA COMBINED WITH THETA-E ADVECTION IS HELPING TO PRODUCE A DECENT AMOUNT OF CLOUD COVER. THERE MAY BE SOME BREAKS IN THIS AS THE FLOW ABOVE THE SURFACE INCREASES SOME, HOWEVER IT WILL ALSO BE FIGHTING AN INVERSION. THE INITIAL WAA AND INCREASE IN MOISTURE MAY BE ENOUGH TO RESULT IN SOME ISENTROPIC LIFT TO POP A FEW SHOWERS THIS MORNING MAINLY ACROSS OUR WESTERN TO NORTHERN ZONES. THIS SCENARIO WAS LESS CERTAIN AS SOME MODEL GUIDANCE THAT HINTED AT THIS SEEM TO HAVE LOST A SUBTLE SHORT WAVE RUNNING OUT AHEAD OF THE MAIN FEATURE. THE HRRR HAD THE RIGHT IDEA, BUT SO FAR IT IS OVERDONE WITH THE COVERAGE. THERE WAS HOWEVER A SMALL GROUP OF SHOWERS THAT DEVELOPED IN THE LEHIGH VALLEY BUT THEN DISSIPATED AS IT MOVED NORTHEASTWARD. ANOTHER ISOLATED SHOWER CANNOT BE RULED OUT EARLY, BUT OTHERWISE THE MAIN POPS WERE DELAYED SOME AND THEN WERE GRADUALLY EXPANDED AND INCREASED EASTWARD WITH TIME. AS WE STEP FORWARD THROUGH THE DAY, ENOUGH HEATING COMBINED WITH CLIMBING SURFACE DEW POINTS SHOULD RESULT IN ENOUGH INSTABILITY /MLCAPE UP TO 1500 J/KG/ TO PRODUCE SHOWERS AND THUNDERSTORMS. THE BULK OF THIS ACTIVITY IS EXPECTED TO DEVELOP TO OUR WEST NEAR A WEAK FRONTAL BOUNDARY WITH ADDITIONAL DEVELOPMENT POSSIBLY NEAR A DIFFERENTIAL HEATING ZONE. THE HEIGHT FALLS ARE WEAK THIS FAR EAST AS THE SHORT WAVE TROUGH TRACKS TO OUR NORTH LATE IN THE DAY. HOWEVER, AN INCREASE IN THE MID LEVEL FLOW TO NEAR 40 KNOTS WILL INCREASE THE SHEAR WITH TIME. THIS SHOULD BE ENOUGH TO PROMOTE SOME STORM ORGANIZATION WITH THE MAIN MODE BEING LINE SEGMENTS. IN ADDITION, THE PW VALUES ARE FORECAST TO INCREASE TO AROUND 2 INCHES WHICH WILL LEAD TO DOWNPOURS. THESE DOWNPOURS MAY RESULT IN BRIEF POOR DRAINAGE FLOODING, HOWEVER THE FLASH FLOOD THREAT GENERALLY LOOKS LOW AS THERE SHOULD BE ENOUGH OF A STORM MOTION. THE MOIST ENVIRONMENT COMBINED WITH ENOUGH INSTABILITY COULD ALSO RESULT IN SOME STORMS PRODUCING FREQUENT LIGHTNING. GIVEN THE FORECAST THERMODYNAMIC SETUP, SOME STORMS WILL BE CAPABLE OF PRODUCING GUSTY TO PERHAPS LOCALLY DAMAGING WINDS. THIS GENERALLY LOOKS TO BE FROM ABOUT THE INTERSTATE 95 CORRIDOR ON NORTH AND WEST BY LATE AFTERNOON. WE THEREFORE MAINTAINED INCREASING POPS FROM WEST TO EAST WITH THE WESTERN ZONES GOING TO LIKELY IN THE AFTERNOON, AND WE ALSO ADDED SOME ENHANCED WORDING. MUCH OF THE EASTERN AND SOUTHEASTERN ZONES MAY REMAIN DRY FOR THE BULK OF THE DAY. AS FOR HIGH TEMPERATURES, WE USED AN EVEN BLEND OF THE NAM/GFS MOS THEN ADJUSTED DOWN A LITTLE BIT FOR SOME AREAS WITH THE IDEA OF LOTS OF CLOUDS PREVAILING. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... THE AFOREMENTIONED SHORT WAVE TROUGH IS FORECAST TO DAMPEN OUT AS IT TRACKS WELL TO OUR NORTH TONIGHT. THERE IS STILL A TRAIL OF SHORT WAVES ROLLING UP THE BACKSIDE OF THE UPPER-LEVEL RIDGE WITH ALSO A WEAKENING FRONTAL BOUNDARY NEARING THE AREA. THE FORECAST SOUNDINGS INDICATE THAT ENOUGH INSTABILITY IS MAINTAINED FOR AWHILE FOR SOME SHOWERS AND THUNDERSTORMS TO CONTINUE THROUGH THE EVENING, ESPECIALLY FROM THE INTERSTATE 95 CORRIDOR ON NORTH AND WEST. A SOMEWHAT MORE PRONOUNCED SHORT WAVE MAY HELP TO FOCUS A CONVECTIVE CLUSTER OVERNIGHT, HOWEVER WHERE THIS IS FOCUSED HAS LESS CERTAINTY WITH IT ATTM. AS THE PW VALUES REMAIN RATHER HIGH, LOCAL DOWNPOURS COULD PUT DOWN A DECENT AMOUNT OF RAIN HOWEVER ANY FLOOD THREAT LOOKS BRIEF AND LOCALIZED. AS MENTIONED ABOVE, SOME STRONG CONVECTION MAY OCCUR IN THE EVENING WITH LOCALLY GUSTY WINDS POSSIBLE. THIS WOULD BE MORE TIED TO ANY LINE SEGMENTS THAT ARE ABLE TO MAINTAIN THEMSELVES WITH PERHAPS SOME ENHANCEMENT FROM WATER LOADED DOWNDRAFTS. OTHERWISE, A WEALTH OF CLOUDS SHOULD BE AROUND THROUGH THE NIGHT FOR MUCH OF THE AREA ALONG WITH MUGGY CONDITIONS. AS FOR LOW TEMPERATURES, AN EVEN BLEND OF THE NAM/GFS MOS WAS GENERALLY USED. && .LONG TERM /MONDAY THROUGH SATURDAY/... UNSETTLED WEATHER IS EXPECTED ON MONDAY WITH CONVECTION STILL POSSIBLE MOST AREAS THROUGH MOST OF THE DAY. LOCALLY HEAVY RAIN IS POSSIBLE JUST ABOUT ANYWHERE...BUT LATEST GUIDANCE SUGGESTS NEAR AND SOUTH AND EAST OF THE I-95 CORRIDOR MIGHT BE FAVORED. ANY FLOODING SHOULD BE MORE URBAN AND POOR DRAINAGE FLOODING. WITH A CONTINUED SOUTHWESTERLY FLOW, TEMPERATURES WILL PEAK 5 TO 10 DEGREES ABOVE NORMAL FOR THE BEGINNING OF SEPTEMBER. MONDAY NIGHT AND TUESDAY...A LULL IN THE PRECIPITATION IS EXPECTED LATE MONDAY NIGHT THROUGH TUESDAY AFTERNOON. IF THERE`S ENOUGH SUNSHINE...TEMPERATURES COULD PEAK OUT IN THE LOW 90S. TUESDAY NIGHT...SHOWERS AND THUNDERSTORMS...SOME WITH LOCALLY HEAVY RAIN...CAN BE EXPECTED AS A COLD FRONT SWINGS THROUGH THE AREA FROM WEST TO EAST. WEDNESDAY THROUGH FRIDAY...THE AIR MASS BEHIND THE COLD FRONT REALLY WON`T BE TOO MUCH COOLER COURTESY OF A MID-LEVEL ZONAL FLOW, BUT IT WILL BE DRIER AND MORE COMFORTABLE. HIGHS ALL THREE DAYS WILL BE PRIMARILY IN THE LOW TO MID 80S, WHICH IS STILL ABOVE NORMAL. BEAUTIFUL EARLY SEPTEMBER WEATHER. SATURDAY...INCREASING CLOUDINESS AS THE DAY WEARS ON AS A COLD FRONT APPROACHES FROM THE WEST. SHOWERS AND THUNDERSTORMS ARE POSSIBLE WITH TEMPERATURES STILL ABOVE NORMAL. && .AVIATION /10Z SUNDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...AREAS OF MVFR TO LOCAL IFR CEILINGS WILL IMPROVE TO VFR CEILINGS BY MIDDAY. AN ISOLATED SHOWER IS POSSIBLE EARLY THIS MORNING MAINLY FROM NEAR KABE AND KRDG, OTHERWISE SOME SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE TO DEVELOP TO OUR WEST AND OVERSPREAD OUR AREA THIS AFTERNOON. SOME TIMING WAS INDICATED IN THE TAFS, WITH THUNDER ONLY MENTIONED AT KABE TO KRDG DUE TO HIGHER CONFIDENCE AS OF NOW. THIS WILL BE REVISITED LATER THIS MORNING. THERE WILL BE BRIEF TIMES OF MVFR/IFR VISIBILITIES ESPECIALLY WITHIN SHOWERS AND THUNDERSTORMS AS DOWNPOURS ARE ANTICIPATED. SOUTH-SOUTHEAST WINDS INCREASING TO GENERALLY 10-15 KNOTS AND BECOMING SOUTH-SOUTHWEST. TONIGHT...SHOWERS AND THUNDERSTORMS SHOULD CONTINUE EASTWARD WITH MUCH OF THE ACTIVITY IN THE EVENING HOURS. AS A RESULT, THERE WILL BE TIMES OF MVFR/IFR DUE TO DOWNPOURS. IN ADDITION, SOME LIGHT FOG COULD DEVELOP LATE IF SOME CLEARING OCCURS COMBINED WITH LIGHT WINDS. OUTLOOK... MONDAY INTO MONDAY NIGHT...IFR CONDITIONS EXPECTED WITH SHOWERS AND THUNDERSTORMS. COVERAGE OF PRECIPITATION DECREASING DURING THE OVERNIGHT HOURS. TUESDAY...GENERALLY VFR CONDITIONS EXPECTED DURING THE DAY. TUESDAY NIGHT...IFR CONDITIONS POSSIBLE AS A COLD FRONT MOVES THROUGH THE AREA. WEDNESDAY THROUGH FRIDAY...GENERALLY VFR CONDITIONS EXPECTED. && .MARINE... A SOUTHERLY FLOW IS EXPECTED THROUGH TONIGHT AHEAD OF A WEAKENING FRONTAL BOUNDARY AS A DISTURBANCE TRACKS WELL TO OUR NORTH. AS THIS OCCURS, THE FLOW IS FORECAST TO INCREASE AND THIS OPENS THE DOOR TO SOME MIXING. IT APPEARS THAT THE WARM AIR ADVECTING ACROSS THE AREA WILL KEEP THE STRONGER WINDS ABOVE THE SURFACE. WHILE THERE CAN BE SOME GUSTINESS ESPECIALLY NEARSHORE, IT GENERALLY LOOKS MARGINAL. THE SOUTHERLY FLOW WILL ALSO ALLOW THE SEAS TO BUILD THROUGH TONIGHT, HOWEVER GIVEN THE SOUTHERLY FLOW DIRECTION AND FETCH, WE KEPT SEAS UP TO 4 FEET. THEREFORE, NO SMALL CRAFT ADVISORY HAS BEEN ISSUED AT THIS TIME. SOME SHOWERS AND THUNDERSTORMS WILL ARRIVE LATE THIS AFTERNOON AND TONIGHT, AND SOME STORMS COULD PRODUCE LOCALLY GUSTY WINDS. OUTLOOK... MONDAY AND MONDAY NIGHT...WINDS AND SEAS SHOULD REMAIN JUST BELOW SMALL CRAFT ADVISORY CRITERIA. GUSTIER WINDS POSSIBLE IN THE VICINITY OF THUNDERSTORMS. TUESDAY THROUGH THURSDAY...WINDS AND SEAS EXPECTED TO REMAIN BELOW SCA CRITERIA. HOWEVER, SOME GUSTY WINDS ARE POSSIBLE WITH THUNDERSTORMS TUESDAY NIGHT AND EARLY WEDNESDAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...MIKETTA NEAR TERM...GORSE SHORT TERM...GORSE LONG TERM...MIKETTA AVIATION...GORSE/MIKETTA MARINE...GORSE/MIKETTA
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
345 PM EDT SUN AUG 31 2014 .SYNOPSIS... 19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A PROGRESSIVE NORTHERN STREAM PATTERN ACROSS THE CONUS OVER THE TOP OF AN ELONGATED WEST TO EAST ORIENTED UPPER RIDGE EXTENDING FROM NORTHERN MEXICO...ACROSS THE DEEP SOUTH AND INTO THE WESTERN ATLANTIC. POTENT SHORTWAVE / MOMENTUM PUSH IS SEEN IN WV IMAGERY EJECTING OUT OF THE INTER-MOUNTAIN WEST ACROSS THE NORTHERN PLAINS. THIS ENERGY IS EXPECTED TO RESULT IN A LARGE AREA OF SEVERE POTENTIAL ACROSS THE NORTHERN PLAINS/UPPER MS VALLEY THIS EVENING. CLOSER TO HOME WE FIND OUR REGION UNDERNEATH THE ELONGATED UPPER RIDGE MENTIONED ABOVE...AND THIS RIDGE WILL BE STAYING PUT FOR THE NEXT SEVERAL DAYS. A SWATH OF MID/UPPER LEVEL DRIER AIR IS CLEARLY SEEN ON WV IMAGERY ARRIVING OVER THE FL PENINSULA FROM THE EAST... ALTHOUGH THE 12Z KTBW SOUNDING PROFILE WAS LAUNCHED AHEAD OF THIS PUSH...AND LIKELY DID NOT SAMPLE MUCH OF THE THIS AIRMASS THAT IS NOW STREAMING OVERHEAD. EVEN STILL...THE 12Z SOUNDING WAS ALREADY DRIER THAN 24 HOURS AGO WITH A PW VALUE DOWN A FEW TENTHS OF AN INCH TO AROUND 1.7". REGIONAL RADARS SHOWING DISORGANIZED SHOWER/STORM ACTIVITY AHEAD OF AND ALONG THE EAST COAST SEA-BREEZE WHICH IS QUICKLY TRANSLATING ACROSS THE STATE THIS MID-AFTERNOON. SHOWERS AND STORMS ARE ALREADY ARRIVING AROUND THE FORT MYERS AREA AND PROGRESSING WESTWARD THROUGH POLK/HIGHLANDS/DESOTO/HARDEE COUNTIES FURTHER TO THE NORTH. AS MENTIONED ABOVE...SO FAR THE CONVECTION IS RATHER DISORGANIZED AND SHALLOW IN NATURE AS THE SYNOPTIC FLOW IS WITH THE SEA-BREEZE FLOW...LIMITING LOW LEVEL FOCUS. DO EXPECT A LEAST SOME MORE ROBUST CONVECTIVE CELLS IN THE NEXT SEVERAL HOURS AS THIS ACTIVITY AND THE EAST COAST SEABREEZE ARRIVES AT THE I-75 CORRIDOR TO THE NORTH OF FORT MYERS. HAVE SEEN SEVERAL OF THE COASTAL OBS FLIP AROUND ONSHORE INDICATING SEA-BREEZE FORMATION...AND THIS SHOULD ENSURE MORE PRONOUNCED CONVERGENCE FOR STRONG UPDRAFTS / DEEP CONVECTION INTO THE EARLY EVENING HOURS. WE HAVE MIXED REALLY WELL SO FAR THIS DIURNAL CYCLE WITH CU BASES AROUND THE REGION GENERALLY AT OR ABOVE 5KFT. THIS SUGGEST WE NOW HAVE A DEEP MIXED LAYER / INVERTED V PROFILE IN THE LOWER LEVELS. WITH THIS IN MIND...STILL BELIEVE WE ARE LOOKING AT AN ENHANCED WIND GUST THREAT FROM THE STRONGER STORMS...AND THIS POTENTIAL WILL NEED TO BE WATCHED CLOSELY ON RADAR THROUGH THE EARLY EVENING PERIOD. && .SHORT TERM (TONIGHT AND MONDAY)... ANY LINGERING STORMS WILL BE QUICKLY EXITING INTO THE GULF WITHIN A COUPLE HOURS OF SUNSET...WHICH WILLS SET UP A MOSTLY DRY AND SEASONABLE OVERNIGHT PERIOD. SIMILAR TO SATURDAY NIGHT...STORMS MAY LINGER FOR A FEW EXTRA HOURS UP OVER THE COASTAL NATURE COAST BEFORE EVEN HERE THE ACTIVITY DIMINISHES AND PUSHES OFFSHORE. WITH THE FAST PROGRESSION OF ACTIVITY FROM EAST TO WEST...THE DURATION OF RAINFALL FOR ANY ONE LOCATIONS DOES NOT LOOK TO BE ALL THAT GREAT...HOWEVER THE CHANCES FOR A PASSING STORM ARE FAIRLY HIGH...ESPECIALLY FROM PASCO/HERNANDO COUNTIES SOUTHWARD. CURRENT GRIDS SHOWS 60-70% COVERAGE THE NEXT SEVERAL HOURS...AND FEEL THIS FORECAST IS STILL VALID. THE OVERALL SYNOPTIC PATTERN DOES NOT CHANGE MUCH HEADING INTO LABOR DAY...AND HENCE NEITHER WILL THE FORECAST. EASTERLY FLOW WILL CONTINUE TO DOMINATE THE REGION ON THE SOUTHERN SIDE OF THE SUBTROPICAL RIDGE AXIS LOCATED NEAR THE I-10 CORRIDOR. MANY OF THE THERMODYNAMIC PARAMETERS THROUGH THE COLUMN LOOK SIMILAR TO TODAY SUGGESTING WIND WILL AGAIN BE THE PRIMARY THREAT WITH ANY OF THE STRONGER STORMS. FORECAST WILL SHOW A QUIET AND MAINLY RAIN FREE MORNING AND EARLY AFTERNOON...FOLLOWED BY INCREASING STORM CHANCES ARRIVING FROM THE EAST WITH THE SEA-BREEZE. THE PEAK OF THE STORMS SHOULD AGAIN FALL BETWEEN 2 AND 6 PM TO THE SOUTH OF SARASOTA...AND 4 TO 8 PM FURTHER NORTH THROUGH THE I-4 CORRIDOR AND UP INTO THE NATURE COAST. && .LONG TERM (TUESDAY NIGHT THROUGH SATURDAY)... NOT MUCH CHANGE FOR THE ONGOING LONG TERM FORECAST. THE ATLANTIC SURFACE RIDGE WILL REMAIN GENERALLY NORTHEAST OF THE AREA...WITH EAST OR SOUTHEAST FLOW CONTINUING. A MID/UPPER-LEVEL LOW WILL MAKE ITS WAY WEST-NORTHWESTWARD TOWARD THE EAST COAST OF FLORIDA THROUGH MID TO LATE WEEK. THE GFS SHOWS A MORE WELL-DEFINED FEATURE WITH 500 MB TEMPS COOLING SLIGHTLY TO -8 DEGREES CELSIUS OVER OUR SOUTHERNMOST ZONES WHILE THE ECMWF IS NOT QUITE AS DEFINED BUT DOES STILL SHOW SOME COOL TEMPS ALOFT OF AROUND -7. ANOTHER FACTOR FOR WEDNESDAY WILL BE THE DRIER AIR THAT MOVES OVER THE REGION...WHICH WOULD TEND TO SCALE BACK POPS A BIT...THOUGH STILL IN THE SCATTERED RANGE...BUT SOME OF THE STORMS THAT DO FORM COULD BE ON THE STRONGER SIDE WITH THE COOLING 500 MB TEMPS. OTHERWISE...EXPECT FAIRLY TYPICAL SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WITH AN EAST TO SOUTHEAST FLOW. TEMPERATURES LOOK TO REMAIN AROUND NORMAL VALUES FOR THE PERIOD. && .AVIATION... VFR CONDITIONS PREVAIL ACROSS THE FORECAST AREA LATE THIS MORNING AS WE AWAIT MORE LATE DAY STORMS. STORMS LATE THIS AFTERNOON AND EARLY EVENING WILL HAVE AN ENHANCED WIND THREAT. OTHERWISE...AWAY FROM THE STORMS EXPECT VFR CONDITIONS TO CONTINUE. STORMS WILL PUSH OFFSHORE WITHIN A COUPLE HOURS OF SUNSET. && .MARINE... HIGH PRESSURE RIDGING ACROSS THE NORTHEASTERN GULF OF MEXICO AND FLORIDA PENINSULA WILL KEEP WINDS LESS THAN 15 KNOTS AND SEAS BELOW 3 FEET FOR THE NEXT SEVERAL DAYS. THE SEA BREEZE WILL SET UP ALONG THE COASTLINE EACH DAY TURNING THE WINDS TO AN ONSHORE FLOW IN THE AFTERNOON. SCATTERED SHOWERS AND STORMS WILL BE POSSIBLE EACH DAY DEVELOPING OVER LAND AND THEN PUSHING WESTWARD OVER THE COASTAL WATERS DURING THE EVENING HOURS. THE ONLY EXPECTED HAZARD WILL BE GUSTY WINDS AND HIGHER SEAS IN THE VICINITY OF THUNDERSTORMS. && .FIRE WEATHER... HIGH PRESSURE WILL REMAIN ALIGNED OVER THE NORTHERN PORTION OF THE STATE THROUGH THE MIDDLE OF THE WEEK. THIS PATTERN WILL KEEP AMPLE ATLANTIC LOW LEVEL MOISTURE IN PLACE TO PREVENT ANY CRITICAL LEVELS OF RELATIVE HUMIDITY. THUNDERSTORMS WILL BE MOST LIKELY ALONG THE I-75 CORRIDOR DURING THE LATE AFTERNOON AND EVENING HOURS THE NEXT SEVERAL DAYS. FOG POTENTIAL...PATCHY GROUND FOG COULD DEVELOP LATE EACH NIGHT...ESPECIALLY IN LOCATIONS THAT RECEIVE RAIN DURING THE PREVIOUS EVENING. HOWEVER...NO SIGNIFICANT FOG IS ANTICIPATED THROUGH THE MIDDLE OF THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... TPA 77 93 78 92 / 30 50 20 50 FMY 75 94 76 92 / 10 60 10 50 GIF 75 94 75 93 / 10 50 10 40 SRQ 75 92 76 91 / 30 60 20 50 BKV 72 93 73 93 / 40 50 20 40 SPG 79 93 80 91 / 40 60 30 50 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/AVIATION/FIRE WX...MROCZKA MARINE...FLEMING LONG TERM...CARLISLE
AREA FORECAST DISCUSSION...CORRECTED
NWS TAMPA BAY RUSKIN FL
1100 AM EDT SUN AUG 31 2014 .UPDATE... 15Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A PROGRESSIVE NORTHERN STREAM PATTERN ACROSS THE CONUS OVER THE TOP OF AN ELONGATED WEST TO EAST ORIENTED UPPER RIDGE EXTENDING FROM NORTHERN MEXICO...ACROSS THE DEEP SOUTH AND INTO THE WESTERN ATLANTIC. POTENT SHORTWAVE / MOMENTUM PUSH IS SEEN IN WV IMAGERY EJECTING OUT OF THE INTER-MOUNTAIN WEST ACROSS THE NORTHERN PLAINS. THIS ENERGY IS EXPECTED TO RESULT IN A LARGE AREA OF SEVERE POTENTIAL ACROSS THE NORTHERN PLAINS/UPPER MS VALLEY LATER TODAY INTO TONIGHT. CLOSER TO HOME WE FIND OUR REGION UNDERNEATH THE ELONGATED UPPER RIDGE MENTIONED ABOVE...AND THIS RIDGE WILL BE STAYING PUT FOR THE NEXT SEVERAL DAYS. A SWATH OF MID/UPPER LEVEL DRIER AIR IS CLEARLY SEEN ON WV IMAGERY ARRIVING OVER THE FL PENINSULA FROM THE EAST... ALTHOUGH THE 12Z KTBW SOUNDING PROFILE WAS LAUNCHED AHEAD OF THIS PUSH...AND LIKELY DID NOT SAMPLE MUCH OF THE THIS AIRMASS THAT IS NOW STREAMING OVERHEAD. EVEN STILL...THE 12Z SOUNDING WAS ALREADY DRIER THAN 24 HOURS AGO WITH A PW VALUE DOWN A FEW TENTHS OF AN INCH TO AROUND 1.7". CONVECTIVE POTENTIAL TODAY IS A BIT TRICKY. NO DOUBT THAT WE WILL SEE STORMS DEVELOPING IN THE FAVORED EASTERLY FLOW...HOWEVER... TODAYS COLUMN PER THIS 12Z SOUNDING IS NOT AS FAVORABLE FOR SUSTAINED DEEP CONVECTION AS WAS SEEN ON SATURDAY. THE MID LEVELS TODAY ARE A BIT WARMER AND ALSO A BIT DRIER. IN ADDITION...THE LOWER LEVELS BELOW 700MB SHOW A BIT OF A WARM/DRY BUBBLE/CAP. DO NOT THINK THAT THIS CAP WILL BE ENOUGH TO STOP CONVECTION...BUT SHOULD CERTAINLY WORK TO DELAY ITS ONSET. WILL NEED TO MIX THE BOUNDARY LAYER A BIT HIGHER TO OVERCOME THIS CIN COMPARED TO YESTERDAY. FEEL THIS LATER DEVELOPMENT WILL BE THE MAIN DIFFERENCE BETWEEN YESTERDAY AND TODAY. SO...THE COLUMN IS A BIT DRIER...BUT NOT ENOUGH TO BE CONSIDERED HOSTILE TO DEEP CONVECTION. ONE CONCERN WITH HAVING TO MIX OUT THE LOWER LEVELS MORE TO REACH THE CONVECTIVE TEMPERATURE IS THAT WE WILL END UP WITH A DEEPER INVERTED V SIGNATURE / MIXED LAYER BY LATE AFTERNOON. THESE HIGHER CLOUD BASES AND DEEP WELL MIXED LAYER WILL PROMOTE AN ENHANCED WIND THREAT WITH THESE LATE DAY STORMS. AS MENTIONED ABOVE...WE ARE SEEING A WELL DEFINED EAST TO SOUTHEAST 1000-700MB SYNOPTIC FLOW TODAY...AND THIS PATTERN IS FAVORED FOR CONVECTIVE DEVELOPMENT ALONG THE I-75 CORRIDOR AS THE FLOW INTERACTS WITH A FEEBLE WEST COAST SEA-BREEZE. HIRES CONVECTIVE ALLOWING SUITE OF MODELS SEEM TO BE PINNING THE I-75 CORRIDOR FROM AROUND TAMPA BAY AND SOUTHWARD FOR THE GREATEST COVERAGE OF STORMS DURING THE LATE AFTERNOON/EARLY EVENING. MANY OF THESE MEMBERS ARE MUCH LESS AGGRESSIVE UP ALONG THE NATURE COAST. NOW THERE IS DEFINITELY A TREND HERE...BUT OVERALL DO NOT SEE MUCH DIFFERENCE IN AIRMASS. PERHAPS A BIT GREATER OVERALL SUPPRESSION IN CLOSER PROXIMITY TO THE UPPER RIDGE AXIS IS MAKING A DIFFERENCE IN THESE SIMULATIONS...BUT THIS SHOULD BE MINOR. WITH THE MORNING FORECAST UPDATE HAVE KEEP RAIN CHANCES LATER TODAY OUT OF THE LIKELY RANGE (GREATER THAN 60%) TO THE NORTH OF PASCO COUNTY...BUT DO NOT FEEL COMFORTABLE GOING LESS THAN CHANCE 40-50% FOR THESE NORTHERN ZONES. HOWEVER...SIMILAR TO SATURDAY...AS YOU HEAD NORTH THROUGH THE NATURE COAST...MUCH OF THE STORM ACTIVITY SHOULD BE INTO THE EVENING HOURS. IN CONTRAST...THE AREAS SOUTH OF TAMPA BAY...ESPECIALLY HIGHLAND COUNTY OVER TO THE FORT MYERS AREAS WILL BE FIRST TO SEE THE CONVECTIVE INITIATION DURING THE EARLY TO MIDDLE AFTERNOON HOURS. THE MORNING SOUNDING SHOWS DEEP LAYER EAST/SE FLOW THROUGH THE COLUMN...AND THE RAP KEEPS THIS GOING THROUGH THE DAY. THEREFORE...THERE IS LITTLE DOUBT IN THE PREVAILING STORM MOTION FROM ESE TO WNW TODAY. BOATERS ON THE COASTAL WATERS SHOULD KEEP A CLOSE EYE TO THE EAST LATE THIS AFTERNOON/EARLY EVENING AS ANY STORMS WILL BE MOVING QUICKLY IN YOUR DIRECTION AND PUSHING OFFSHORE WITH TIME. ANY LINGERING STORMS WILL BE QUICKLY EXITING INTO THE GULF WITHIN A COUPLE HOURS OF SUNSET...WHICH WILLS SET UP A MOSTLY DRY AND SEASONABLE OVERNIGHT PERIOD. THE OVERALL SYNOPTIC PATTERN DOES NOT CHANGE MUCH HEADING INTO LABOR DAY...AND HENCE NEITHER WILL THE FORECAST. EASTERLY FLOW WILL PROMOTE A QUIET MORNING AND THEN MAINLY LATE AFTERNOON/EVENING STORMS. MORE ON THE MONDAY DETAILS WITH THE AFTERNOON DISCUSSION. HAVE A GREAT SUNDAY AND WATCH OUT FOR THOSE GUSTY LATE DAY STORMS. && .AVIATION... VFR CONDITIONS PREVAIL ACROSS THE FORECAST AREA LATE THIS MORNING AS WE AWAIT MORE LATE DAY STORMS. STORMS LATE THIS AFTERNOON AND EARLY EVENING WILL HAVE AN ENHANCED WIND THREAT. OTHERWISE...AWAY FROM THE STORMS EXPECT VFR CONDITIONS TO CONTINUE. STORMS WILL PUSH OFFSHORE WITHIN A COUPLE HOURS OF SUNSET. && .MARINE... EAST SOUTHEAST WINDS LESS THAN 15 KNOTS AND SEAS LESS THAN 3 FEET WILL CONTINUE FOR THE NEXT SEVERAL DAYS AS HIGH PRESSURE OVER THE ATLANTIC RIDGES WEST OVER THE FLORIDA PENINSULA. THE SEA BREEZE WILL SET UP ALONG THE COASTLINE EACH DAY TURNING THE WINDS TO AN ONSHORE FLOW OUT OF THE SOUTHWEST THROUGH NORTHWEST DIRECTION. SCATTERED SHOWERS AND STORMS WILL BE POSSIBLE EACH DAY DEVELOPING OVER LAND AND THEN PUSHING WESTWARD OVER THE COASTAL WATERS DURING THE EVENING HOURS. THE ONLY EXPECTED HAZARD WILL BE GUSTY WINDS AND HIGHER SEAS IN THE VICINITY OF THUNDERSTORMS. && .PRELIMINARY POINT TEMPS/POPS... TPA 93 76 93 78 / 70 30 50 40 FMY 94 75 94 76 / 70 10 50 30 GIF 94 75 94 75 / 40 10 40 10 SRQ 94 74 93 76 / 70 30 50 40 BKV 94 72 94 73 / 50 40 40 30 SPG 93 79 93 80 / 70 40 50 40 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE/AVIATION...MROCZKA MARINE...WYNN
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
239 PM EDT SUN AUG 31 2014 .SYNOPSIS... A PERSISTENT UPPER RIDGE WILL KEEP VERY WARM TEMPERATURES IN THE FORECAST THIS WEEK. INCREASED LOW LEVEL MOISTURE WILL RESULT IN CHANCES OF AFTERNOON STORMS AND HUMID CONDITIONS WITH HEAT INDICES AT OR ABOVE 100 DEGREES. && .NEAR TERM /THROUGH TONIGHT/... WATER VAPOR IMAGERY EARLY THIS AFTERNOON INDICATES THE UPPER RIDGE AXIS IS RIGHT OVERHEAD EXTENDING FROM SOUTHEAST VIRGINA THROUGH THE CENTRAL CAROLINAS INTO SOUTHERN GEORGIA. PRECIPITABLE WATER AXIS JUST UNDER 2 INCHES EXTENDS NORTHWARD ALONG THE I-20 CORRIDOR AND REGIONAL RADAR SHOWING SCATTERED SHOWERS DEVELOPING ALONG THIS AXIS IN SOUTHEAST GEORGIA INTO THE CSRA. HRRR HAD A GOOD HANDLE ON THIS AND HAVE HIGHEST POPS THIS AFTERNOON IN THE SOUTHEAST PORTION OF THE FORECAST AREA BUT STILL MAINTAINING CHANCE POPS. UPPER FLOW REMAINS VERY WEAK WITH STORM MOTION GENERALLY 5 KNOTS OR LESS AND CONVECTION HAS BEEN GOING UP AND RIGHT BACK DOWN FAIRLY QUICKLY AS THEY RAIN THEMSELVES OUT. THINK SEVERE THREAT REMAINS LOW GIVEN SUCH WARM AIR IN THE LOWER 20KFT AND SURFACE TEMPERATURES PUSHING INTO THE MID AND UPPER 90S. SOME LINGERING SHOWERS MAY EXIST THROUGH THE LATE EVENING HOURS BUT EXPECT PRECIPITATION TO END BY 06Z OR SO WITH SOME CONVECTIVE DEBRIS CLOUD OVER THE AREA TONIGHT. TEMPERATURES WILL BE WARM AGAIN TONIGHT IN THE LOW TO MID 70S AFTER SUCH A WARM DAY WITH CLOUD COVER AND ABUNDANT LOW LEVEL MOISTURE LIMITING RADIATIONAL COOLING. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... STRONG MID/UPPER LEVEL RIDGE CONTINUES TO HOLD ALONG THE SOUTHEAST COAST INTO MONDAY NIGHT. S/W ENERGY ACROSS THE CNTRL/NRN PLAINS WILL CONTINUE TO MOVE EASTWARD ACROSS THE GREAT LAKES AND FLATTEN OUT THE AMPLITUDE OF THE RIDGE...BUT THE SOUTHEAST REMAINS UNDER HIGHER HEIGHTS AND SEPARATE FROM THE MAIN W TO E FLOW. LOW LEVEL FLOW REMAINS FROM THE SOUTH TO SOUTH-SOUTHWEST THROUGH THE PERIOD. THIS WILL HELP TO KEEP LOW LEVEL MOISTURE IN PLACES WITH DEWPOINTS RANGING FROM THE MIDDLE 60S TO LOWER 70S. HOWEVER...CHANCES FOR SHOWERS/THUNDERSTORMS LOOK LOW THROUGH THE PERIOD. GUIDANCE POPS ALONG WITH LACK OF UPPER TRIGGERS INDICATING ONLY SLIGHT CHANCE POPS THROUGH THE PERIOD. CONVECTIVE ACTIVITY WILL BE MAINLY DIURNAL IN NATURE WITH ONLY SOME WEAK SURFACE CONVERGENCE/SEA BREEZE ACTION EACH DAY. AS FOR TEMPERATURES...EXPECT AFTERNOON TEMPERATURES TO CONTINUE THE RUN OF 5 TO 10 DEGREES ABOVE NORMAL. AS HIGHS THIS AFTERNOON HAVE CLIMBED INTO THE UPPER 90S IN SOME AREAS...DECIDED TO RAISE AFTERNOON HIGHS FOR MONDAY BASED ON CURRENT TRENDS AND BOUNDARY LAYER/H8 TEMPS. EXPECT MIDDLE TO UPPER 90S ACROSS MOST LOCATIONS. LIKE THIS AFTERNOON A LOCATION OR TWO MAY REACH THE CENTURY MARK. OVERNIGHT LOWS WILL BE IN THE LOWER 70S. AFTERNOON HEAT INDEX VALUES TOMORROW WILL CLIMB TO AROUND 105 DEGREES. && .LONG TERM /TUESDAY THROUGH SATURDAY/... NO REAL CHANGES TO THE EXTENDED FORECAST. UPPER RIDGE CONTINUES OVER THE AREA FROM TUESDAY THROUGH NEXT WEEKEND. IN FACT THE RIDGE BEGINS TO AMPLIFY ONCE AGAIN BEGINNING WEDNESDAY THROUGH FRIDAY. THE THE MAIN FLOW ACROSS THE NORTHERN HALF OF THE U.S....EXPECT S/W ACTIVITY TO REMAIN NORTH OF THE AREA FROM THE NRN PLAINS AND GREAT LAKES INTO NEW ENGLAND/MID ATLANTIC REGION AND REMAINING NORTH OF THE CWA. LOW-LEVEL MOISTURE CONTINUES TO SLOWLY INCREASE DURING THE BEGINNING OF THE PERIOD AND REMAIN BETWEEN 1.5 AND 2.0 INCHES THROUGH THE WEEK AND INTO THE WEEKEND. A WEAK BOUNDARY TRIES TO MOVE SOUTHWARD INTO THE REGION WEDNESDAY...BUT MODELS CONTINUE TO SHOW IT HANGING UP JUST NORTH AND WEST OF THE CWA. REMNANTS OF BOUNDARY LINGER JUST NORTH OF THE CWA THROUGH MUCH OF THE WEEK. OTHERWISE...JUST A SLIGHT CHANCE/LOW CHANCE POPS THROUGH THE PERIOD. STILL LOOKS TO BE DIURNAL IN NATURE WITH AFTERNOON HEATING WITH WEAK SURFACE CONVERGENCE AND LITTLE/NO UPPER SUPPORT. TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL THROUGH THE REMAINDER OF THE LONG TERM PERIOD. EXPECT AFTERNOON HIGHS IN THE LOW/MID 90S AND OVERNIGHT LOWS IN THE LOW/MID 70S. NORMALS HIGHS ARE IN THE UPPER 80S AND LOWS NEAR 70. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... VFR CONDITIONS THROUGH MUCH OF THE PERIOD EXPECTED WITH ISOLATED SHOWERS 18Z-02Z. HAVE INCLUDED VCSH AT CAE/CUB/AGS/DNL WITH RADAR INDICATING CONVECTION DEVELOPING ALONG A WEAK CONVERGENCE LINE POSITIONED ALONG THE I-20 CORRIDOR. THINK THE STRENGTH OF THE UPPER RIDGE OVERHEAD WILL LIMIT CONVECTION AND POSSIBILITY OF THUNDER SO NOT MENTIONING AT THIS TIME. SOUTHERLY WINDS AROUND 5 TO 10 MPH THIS AFTERNOON BECOMING LIGHT AND VARIABLE OVERNIGHT. EXPECT SOME LIGHT MVFR FOG TO DEVELOP LATE TONIGHT GIVEN ABUNDANT BOUNDARY LAYER MOISTURE IN PLACE...ALTHOUGH POSSIBLE DEBRIS CLOUDS MAY IMPACT FOG POTENTIAL LEADING TO LOWER CONFIDENCE. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN LATE NIGHT AND EARLY MORNING STRATUS AND FOG. SCATTERED MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS SUNDAY THROUGH THURSDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
150 PM CDT SUN AUG 31 2014 .DISCUSSION... 328 AM CDT AFTER A FAIRLY QUIET DAY ACROSS THE AREA TODAY...ATTENTION QUICKLY SHIFTS TO THE WEATHER FOR LABOR DAY INTO MONDAY NIGHT...DURING WHICH PERIODS OF EXTREMELY HEAVY RAINFALL AND SEVERE WEATHER ARE POSSIBLE. THUNDERSTORMS CONTINUED TO TRAIN ACROSS THE SAME AREAS ACROSS PORTIONS OF FORD AND IROQUOIS COUNTIES IN ILLINOIS AND ALSO BENTON COUNTY IN INDIANA YESTERDAY EVENING AND INTO THE OVERNIGHT HOURS. THESE AREAS LIED IN THE RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET STREAK. THE COMBINATION OF THIS...AND THE CONTINUED LOW LEVEL CONFLUENCE CONTINUED TO DRIVE THIS CONVECTION. RADAR ESTIMATES SOME VERY HEFTY ISOLATED RAINFALL AMOUNTS IN EXCESS OF 4 INCHES ACROSS PORTIONS OF THESE COUNTIES. ALTHOUGH SOME ISOLATED ACTIVITY CONTINUES ACROSS THIS AREA AS OF THIS WRITING...IT IS EXPECTED THAT ALL THIS ACTIVITY WILL SHIFT OUT OF THE AREA AROUND...OR JUST PRIOR TO DAYBREAK AS THE UPPER LEVEL JET DEVELOPS EASTWARD. WATER VAPOR IMAGERY EARLY THIS MORNING SHOWS THE NEXT UPPER LEVEL SYSTEM CURRENTLY DIGGING ACROSS THE ROCKIES. AIRCRAFT AND UPPER AIR OBSERVATIONS ACROSS WESTERN CANADA AND OVER THE NORTHEAST PACIFIC INDICATE SOME IMPRESSIVE UPPER LEVEL WINDS...FOR THIS TIME OF YEAR...IN EXCESS OF 110 KT WITHIN THE CORE OF THE JET STREAK DIGGING OVER THE WESTERN CONUS. THE FIRST MID LEVEL IMPULSE IS EXPECTED TO CONTINUE SHIFTING EASTWARD OVER THE UPPER MIDWEST INTO MONDAY MORNING. AS IT DOES SO...IT WILL DRIVE A FAIRLY STOUT SURFACE LOW NORTHEASTWARD FROM THE DAKOTAS TO ONTARIO. SOME VERY SUBSTANTIAL CONVECTION IS EXPECTED TO DEVELOP AHEAD OF THE COLD FRONT LATER TODAY ACROSS PORTIONS OF THE MID MISSOURI VALLEY AND INTO MINNESOTA. THIS ACTIVITY WILL LIKELY SHIFT EAST-NORTHEASTWARD OVERNIGHT TONIGHT...WITH SOME OF THE REMNANT ACTIVITY POSSIBLY REACHING NORTH CENTRAL ILLINOIS BY AROUND...OR JUST PRIOR TO DAYBREAK MONDAY. IT APPEARS THAT THIS INITIAL ROUND OF CONVECTION COULD BE IN A WEAKENING PHASE AS IT TRIES TO PUSH OVER PORTIONS OF NORTHERN ILLINOIS MONDAY MORNING. HOWEVER...RENEWED CONVECTIVE DEVELOPMENT...POSSIBLY ALONG ANY OUTFLOW BOUNDARIES LAID DOWN BY EARLY MORNING ACTIVITY...IS LIKELY ACROSS PORTIONS OF NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA BY MONDAY AFTERNOON. MODEL SOUNDINGS ALL INDICATE FAVORABLE PROFILES FOR ACTIVE STRONG TO SEVERE STORMS OVER THE AREA DURING THE AFTERNOON AND EARLY EVENING MONDAY. DEEP LAYER BULK SHEAR LOOKS TO BE SOMEWHAT UNIDIRECTIONAL...BUT WITH 0-6 KM SPEED SHEAR OF NEARLY 50 KT...ORGANIZED CONVECTIVE ACTIVITY APPEARS VERY POSSIBLE. THE MAIN COMPLICATING FACTOR AT THIS POINT IS HOW MUCH ANY CLOUD DEBRIS OR REMNANT MORNING CONVECTIVE ACTIVITY IMPACTS AFTERNOON HEATING AND DESTABILIZATION ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA. HOWEVER...IN SPITE OF THIS POSSIBILITY EARLY IN THE DAY...IT DOES APPEAR THAT THE HIGH THETA E NEAR SURFACE AIR MASS SHOULD BE ENOUGH TO PRODUCE AMPLE MLCAPE VALUES AT OR JUST IN EXCESS OF 1500 J/KG...WHICH COMBINED WITH THE 45+ DEEP LAYER SHEAR CERTAINLY POINTS TO A SEVERE THREAT. AT THIS TIME IT APPEARS RATHER MODEST MID LEVEL LAPSE RATES WOULD RESULT IN THE MAIN SEVERE THREAT BEING STRONG DAMAGING WIND GUSTS. HOWEVER...THERE IS ALSO A SECONDARY THREAT OF LARGE HAIL...ESPECIALLY IF ANY SUPER CELLS CAN FORM. THERE IS ALSO A DECENT CONCERN FOR EXTREMELY HEAVY RAINFALL RATES WITH THESE STORMS...WITH PWAT VALUES IN THIS JUICY ENVIRONMENT LIKELY TO RESIDE AROUND 1.7 INCHES. NUMERICAL GUIDANCE CONTINUES TO SUGGEST THAT A SECONDARY MID LEVEL IMPULSE WILL APPROACH THE AREA MONDAY NIGHT AND ACT TO INDUCE/STRENGTHEN A SOUTHWESTERLY UPPER LEVEL JET STREAK ACROSS THE GREAT LAKES REGION INTO MONDAY NIGHT. THIS PROCESS COULD SET UP PORTIONS OF THE AREA WITHIN THE FAVORABLE RIGHT ENTRANCE REGION OF A 100 KT UPPER LEVEL JET INTO TUESDAY MORNING AS THE SURFACE COLD FRONTAL BOUNDARY SLOWLY TRIES TO SHIFT SOUTHWARD ACROSS THE SOUTHERN HALF OF MY CWA. I HAVE INCREASING CONCERNS THAT THIS COULD SET UP A VERY HEAVY RAIN EVENT MONDAY NIGHT...WITH STORMS POTENTIALLY TRAINING TO THE EAST NORTHEAST NEARLY PARALLEL TO THE SURFACE BOUNDARY. AT THIS TIME IT APPEARS THIS HEAVY RAIN THREAT COULD END UP SOUTH OF INTERSTATE 80 MONDAY NIGHT. HOWEVER...UNCERTAINTY IS STILL A BIT HIGH AS TO HOW FAR SOUTH THE SURFACE FRONT WILL GET MONDAY NIGHT...AND HENCE WHERE THE MOST FAVORED AREAS FOR TRAINING CELLS WILL OCCUR. AT THIS POINT...I HAVE ADDED HEAVY RAIN WORDING TO THE FORECAST...MAINLY FOR AREAS SOUTH OF INTERSTATE 80 INTO MONDAY NIGHT. FOLLOWING THIS ACTIVE WEATHER MONDAY NIGHT IT APPEARS THE WEATHER WILL BE DRY FOR THE MOST PART THROUGH LATE WEEK. THE MAIN STORY HOWEVER...WILL BE THE INCREASING HEAT BY THURSDAY. FORECAST GUIDANCE CONTINUES TO FORECAST MID LEVEL HEIGHTS TO BUILD SUBSTANTIALLY ACROSS THE CENTRAL CONUS. THIS COULD LEAD TO A RUN AT 90 TEMPERATURES FOR THURSDAY AS 850 MB TEMPERATURES WARM TO 20 TO 22C. I HAVE STARTED CUTTING BACK ON THE SLIGHT CHANCE POPS...ESPECIALLY ON WEDNESDAY AND WEDNESDAY NIGHT...BUT LEFT IN SOME SLIGHTS FOR THURSDAY. ALTHOUGH SOME ISOLATED CONVECTIVE ACTIVITY IS POSSIBLE DURING THIS TIME...IT APPEARS THAT THE BUILDING HEIGHTS AND WARMING TEMPS ALOFT COULD END UP CAPPING THE AREA...AND LIMITING THE THREAT FOR CONVECTIVE DEVELOPMENT THROUGH THURSDAY. CONVECTIVE CHANCES DO LOOK TO RETURN TO THE AREA AGAIN BY FRIDAY. ANOTHER SIGNIFICANT WAVE IS EXPECTED TO SHIFT EASTWARD ACROSS THE NORTHERN CONUS AND SOUTHERN CANADA LATE IN THE PERIOD...AND THIS LOOKS TO SHIFT A COLD FRONT SOUTHWARD ACROSS THE AREA SOMETIME EITHER FRIDAY OR FRIDAY NIGHT AND THIS COULD SPARK OFF ACTIVITY ACROSS THE AREA. COOLER WEATHER DOES LOOK TO OVERSPREAD TO AREA UNDER NORTHERLY WINDS BY EARLY NEXT WEEKEND. KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * LAKE BREEZE THIS AFTERNOON AND WHETHER OR NOT IT WILL PUSH ACROSS ORD/MDW. * GUSTY SOUTHWEST WINDS DEVELOPING MID MORNING MONDAY. * CHANCES FOR THUNDERSTORMS...WITH A LOWER CHANCE OF LINGERING PRECIP COMING IN TOMORROW MORNING...AND A BETTER CHANCE FOR NEW DEVELOPMENT OF STRONG THUNDERSTORMS MONDAY AFTERNOON. BMD //DISCUSSION...UPDATED 18Z... THIS AFTERNOON...WEAK HIGH PRESSURE IS IN PLACE TODAY ALLOWING FOR GENERALLY LIGHT SOUTHWEST FLOW. A LAKE BREEZE HAS ALREADY DEVELOPED THOUGH REMAINS FAIRLY CLOSE TO THE SHORE AT THIS HOUR. IT IS UNCERTAIN WHETHER IT WILL MAKE IT ACROSS THE TERMINALS BUT MOST GUIDANCE IS LEANING AGAINST THIS OCCURRING...AND IF IT DOES IT WOULD LIKELY BE LATE. ATTENTION TURNS TO THE WEST TONIGHT AS AN UPPER LEVEL DISTURBANCE PUSHES ACROSS THE PLAINS KICKING OFF THUNDERSTORMS. THESE THUNDERSTORMS ARE EXPECTED TO PERSIST THROUGH THE OVERNIGHT HOURS MOVING INTO NORTHERN ILLINOIS EARLY MONDAY MORNING IN A DISSIPATING STAGE. RFD HAS BEST CHANCE FOR SEEING SOME FESTERING EARLY MORNING ACTIVITY SO ADDED A PROB30 FOR TSRA. DEPENDING ON HOW FAR EAST THIS PRECIP MAKES IT EARLY MONDAY...EXPECT THE ATMOSPHERE TO RECOVER BECOMING MODERATELY UNSTABLE WITH ADDITIONAL THUNDERSTORMS EXPECTED TO REDEVELOP MONDAY AFTERNOON. THESE STORMS COULD BE STRONG TO SEVERE WITH GUSTY WINDS THE PRIMARY THREAT. BMD //ORD AND MDW CONFIDENCE...UPDATED 18Z... * LOW CONFIDENCE IN LAKE BREEZE MAKING IT THROUGH ORD/MDW TODAY. * LOW-MEDIUM CONFIDENCE IN CIGS REST OF TODAY. * MEDIUM-HIGH CONFIDENCE IN WIND SPEEDS AND DIRECTION MONDAY. * HIGH CONFIDENCE IN AT LEAST A PERIOD OF TSRA BUT LOW CONFIDENCE IN SPECIFIC TIMING. BMD //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...CHANCE SHRA/TSRA. TUESDAY AND WEDNESDAY...VFR. WX NIL. THURSDAY THROUGH SATURDAY...PERIODIC CHANCES FOR SHRA/TSRA. KREIN && .MARINE... 149 PM CDT THE WEATHER PATTERN ACROSS THE WESTERN LAKES WILL BE FAIRLY PROGRESSIVE OVER THE NEXT SEVERAL DAYS...WITH A PAIR OF SURFACE LOWS PASSING ACROSS OR NORTH OF THE NORTHERN LAKES AND TRAILING COLD FRONTS ACROSS LAKE MICHIGAN. THE FIRST LOW...OVER FAR NORTHWEST MINNESOTA THIS AFTERNOON...WILL MOVE NORTHEAST ACROSS ONTARIO AND THE NORTHERN LAKES THROUGH MONDAY WITH ITS TRAILING COLD FRONT PUSHING SOUTHEAST ACROSS THE LAKE MONDAY AFTERNOON AND EVENING. TIGHTENING OF THE GRADIENT AHEAD OF THE LOW AND FRONTAL TROUGH WILL RESULT IN SOUTHERLY WINDS INCREASING LATE TONIGHT AND MONDAY...WITH GUSTS REACHING THE 20-25 KT RANGE AND CONTINUING INTO EARLY MONDAY EVENING BEFORE THE GRADIENT WEAKENS ALONG THE COLD FRONTAL TROUGH. THIS FRONT WILL PUSH SOUTHEAST ACROSS THE LAKE MONDAY NIGHT...WITH LIGHTER WINDS OVERNIGHT AND TUESDAY AS A BUBBLE HIGH MOVES ACROSS THE AREA BEHIND THE FRONT. THE HIGH WILL MOVE OFF TO THE EAST WEDNESDAY MORNING...WITH WINDS BECOMING SOUTH AND STRENGTHENING TO 20-25 KT AGAIN LATER IN THE WEDNESDAY AND CONTINUING INTO THURSDAY BEFORE THE NEXT SURFACE LOW PASSES NORTH OF THE LAKES AND ITS TRAILING COLD FRONT MOVES THROUGH LATE THURSDAY NIGHT AND EARLY FRIDAY. WINDS DONT LOOK TO BE TOO STRONG IMMEDIATELY BEHIND THIS SECOND FRONT...THOUGH A PERIOD OF ENHANCED NORTHERLY WINDS IS POSSIBLE SATURDAY AS HIGH PRESSURE BUILDS IN BEHIND THE FRONT. WITH GUSTY SOUTH WINDS MONDAY...A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THE ILLINOIS AND INDIANA NEAR SHORE WATERS FROM MID-MORNING THROUGH MORNING EVENING. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744- LMZ745...10 AM MONDAY TO 10 PM MONDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1243 PM CDT Sun Aug 31 2014 .UPDATE... ISSUED AT 948 AM CDT SUN AUG 31 2014 A low overcast persists across much of central Illinois along and east of a Peoria to Jacksonville line this morning. 1430z visible satellite imagery is showing thin spots developing in the cloud cover, so am expecting it to dissipate within the next 2 to 3 hours. HRRR ceiling forecast shows this trend quite nicely, resulting in a partly to mostly sunny afternoon. May see a few showers/thunder pop up along/south of I-70: however, areal coverage will remain spotty. Updated the forecast to better reflect sky cover trends this morning and to confine PoPs to just the far SE KILX CWA. && .SHORT TERM...(Today and tonight) ISSUED AT 358 AM CDT SUN AUG 31 2014 Shortwave trough and jet entrance region that brought banded convection and some locally heavy precipitation to central IL last evening has shifted northeastward with shower activity nearly ended over the ILX CWA. With clearing skies and good radiational cooling, patchy fog will continue to form overnight, mainly I-55 westward. Moist conditions with enough instability will remain through the afternoon today for a few showers and thunderstorms, mainly I-70 southeastward, but a relatively dry day expected. Highs in the mid 80s are expected. After sunset, convection should end quickly across the CWA with the loss of surface heating. Late in the night, chances for thunderstorms will spread back into west central Illinois as another cold front approaches from the west. && .LONG TERM...(Monday through Saturday) ISSUED AT 358 AM CDT SUN AUG 31 2014 SPC continues a slight risk (15+%) of severe thunderstorms across central IL nw of a Flora to Robinson line Monday afternoon/evening for damaging winds and large hail. This seems reasonable considering surface to 6 km bulk shear values of 30-40 kts, CAPES of 2-3k J/kg. Heavy rains also possible with thunderstorms in tropical airmass ahead of frontal boundary. Short waves and 30-40 kt low level jet moving into IL river valley later Sunday night into Monday morning and then spreading into eastern IL Monday afternoon/evening. Upper level trof over northern Rockies moves east into Midwest Monday/Monday night and drives a cold front southeast across central IL Monday night. Continued likely pops across much of area Monday afternoon into Monday night, though diminishing pops overnight Monday night nw of IL river. Best chances of showers and thunderstorms lingers over areas from I-72 south on Tue especially in the morning. The 5% risk of severe storms Tue is southeast of Lawrenceville. Quite warm and humid Monday ahead of front with highs 82-88F and dewpoints 70-75F and warmest temps in southeast IL where rain arrives later. Frontal boundary to weaken as it moves se into Ohio River valley Tue/Wed with near zonal upper level flow over the region. Carried just slight chance of convection during midweek from Tue night through Thu night. Highs in the low to mid 80s Tue/Wed climb into mid 80s to around 90F Thu/Fri as dewpoints rise back into the low to mid 70s with heat indices approaching 100F southern counties Thu/Fri afternoon. Next frontal boundary press southeast into IL Friday afternoon into Sat and bringing next best chances of showers and thunderstorms and cooler temps during next weekend. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) ISSUED AT 1243 PM CDT SUN AUG 31 2014 MVFR ceilings will persist at the central Illinois terminals for the next hour or two before gradually dissipating as the afternoon progresses. Based on satellite trends, have scattered ceilings at most sites by 19z, then at KDEC and KBMI by 20z. After that, mostly clear skies will prevail through the evening before clouds begin to increase from the west late tonight. A thunderstorm complex currently developing across western Iowa/Nebraska will track eastward tonight, with most model guidance keeping it west of the Illinois River until 12z. Think storms will arrive in the Illinois River Valley toward dawn in a weakening state, then spread eastward across the area Monday morning. Have therefore introduced low VFR ceilings and VCTS at KPIA after 12z, then further east to KBMI and KDEC after 14/15z. Given plenty of low-level moisture and relatively light winds, included slightly reduced visbys down to 4sm at KCMI where skies will remain mostly clear through dawn. Further west, think increasing clouds and wind will prevent fog formation. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BARNES SHORT TERM...ONTON LONG TERM...07 AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1108 AM CDT SUN AUG 31 2014 .DISCUSSION... 328 AM CDT AFTER A FAIRLY QUIET DAY ACROSS THE AREA TODAY...ATTENTION QUICKLY SHIFTS TO THE WEATHER FOR LABOR DAY INTO MONDAY NIGHT...DURING WHICH PERIODS OF EXTREMELY HEAVY RAINFALL AND SEVERE WEATHER ARE POSSIBLE. THUNDERSTORMS CONTINUED TO TRAIN ACROSS THE SAME AREAS ACROSS PORTIONS OF FORD AND IROQUOIS COUNTIES IN ILLINOIS AND ALSO BENTON COUNTY IN INDIANA YESTERDAY EVENING AND INTO THE OVERNIGHT HOURS. THESE AREAS LIED IN THE RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET STREAK. THE COMBINATION OF THIS...AND THE CONTINUED LOW LEVEL CONFLUENCE CONTINUED TO DRIVE THIS CONVECTION. RADAR ESTIMATES SOME VERY HEFTY ISOLATED RAINFALL AMOUNTS IN EXCESS OF 4 INCHES ACROSS PORTIONS OF THESE COUNTIES. ALTHOUGH SOME ISOLATED ACTIVITY CONTINUES ACROSS THIS AREA AS OF THIS WRITING...IT IS EXPECTED THAT ALL THIS ACTIVITY WILL SHIFT OUT OF THE AREA AROUND...OR JUST PRIOR TO DAYBREAK AS THE UPPER LEVEL JET DEVELOPS EASTWARD. WATER VAPOR IMAGERY EARLY THIS MORNING SHOWS THE NEXT UPPER LEVEL SYSTEM CURRENTLY DIGGING ACROSS THE ROCKIES. AIRCRAFT AND UPPER AIR OBSERVATIONS ACROSS WESTERN CANADA AND OVER THE NORTHEAST PACIFIC INDICATE SOME IMPRESSIVE UPPER LEVEL WINDS...FOR THIS TIME OF YEAR...IN EXCESS OF 110 KT WITHIN THE CORE OF THE JET STREAK DIGGING OVER THE WESTERN CONUS. THE FIRST MID LEVEL IMPULSE IS EXPECTED TO CONTINUE SHIFTING EASTWARD OVER THE UPPER MIDWEST INTO MONDAY MORNING. AS IT DOES SO...IT WILL DRIVE A FAIRLY STOUT SURFACE LOW NORTHEASTWARD FROM THE DAKOTAS TO ONTARIO. SOME VERY SUBSTANTIAL CONVECTION IS EXPECTED TO DEVELOP AHEAD OF THE COLD FRONT LATER TODAY ACROSS PORTIONS OF THE MID MISSOURI VALLEY AND INTO MINNESOTA. THIS ACTIVITY WILL LIKELY SHIFT EAST-NORTHEASTWARD OVERNIGHT TONIGHT...WITH SOME OF THE REMNANT ACTIVITY POSSIBLY REACHING NORTH CENTRAL ILLINOIS BY AROUND...OR JUST PRIOR TO DAYBREAK MONDAY. IT APPEARS THAT THIS INITIAL ROUND OF CONVECTION COULD BE IN A WEAKENING PHASE AS IT TRIES TO PUSH OVER PORTIONS OF NORTHERN ILLINOIS MONDAY MORNING. HOWEVER...RENEWED CONVECTIVE DEVELOPMENT...POSSIBLY ALONG ANY OUTFLOW BOUNDARIES LAID DOWN BY EARLY MORNING ACTIVITY...IS LIKELY ACROSS PORTIONS OF NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA BY MONDAY AFTERNOON. MODEL SOUNDINGS ALL INDICATE FAVORABLE PROFILES FOR ACTIVE STRONG TO SEVERE STORMS OVER THE AREA DURING THE AFTERNOON AND EARLY EVENING MONDAY. DEEP LAYER BULK SHEAR LOOKS TO BE SOMEWHAT UNIDIRECTIONAL...BUT WITH 0-6 KM SPEED SHEAR OF NEARLY 50 KT...ORGANIZED CONVECTIVE ACTIVITY APPEARS VERY POSSIBLE. THE MAIN COMPLICATING FACTOR AT THIS POINT IS HOW MUCH ANY CLOUD DEBRIS OR REMNANT MORNING CONVECTIVE ACTIVITY IMPACTS AFTERNOON HEATING AND DESTABILIZATION ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA. HOWEVER...IN SPITE OF THIS POSSIBILITY EARLY IN THE DAY...IT DOES APPEAR THAT THE HIGH THETA E NEAR SURFACE AIR MASS SHOULD BE ENOUGH TO PRODUCE AMPLE MLCAPE VALUES AT OR JUST IN EXCESS OF 1500 J/KG...WHICH COMBINED WITH THE 45+ DEEP LAYER SHEAR CERTAINLY POINTS TO A SEVERE THREAT. AT THIS TIME IT APPEARS RATHER MODEST MID LEVEL LAPSE RATES WOULD RESULT IN THE MAIN SEVERE THREAT BEING STRONG DAMAGING WIND GUSTS. HOWEVER...THERE IS ALSO A SECONDARY THREAT OF LARGE HAIL...ESPECIALLY IF ANY SUPER CELLS CAN FORM. THERE IS ALSO A DECENT CONCERN FOR EXTREMELY HEAVY RAINFALL RATES WITH THESE STORMS...WITH PWAT VALUES IN THIS JUICY ENVIRONMENT LIKELY TO RESIDE AROUND 1.7 INCHES. NUMERICAL GUIDANCE CONTINUES TO SUGGEST THAT A SECONDARY MID LEVEL IMPULSE WILL APPROACH THE AREA MONDAY NIGHT AND ACT TO INDUCE/STRENGTHEN A SOUTHWESTERLY UPPER LEVEL JET STREAK ACROSS THE GREAT LAKES REGION INTO MONDAY NIGHT. THIS PROCESS COULD SET UP PORTIONS OF THE AREA WITHIN THE FAVORABLE RIGHT ENTRANCE REGION OF A 100 KT UPPER LEVEL JET INTO TUESDAY MORNING AS THE SURFACE COLD FRONTAL BOUNDARY SLOWLY TRIES TO SHIFT SOUTHWARD ACROSS THE SOUTHERN HALF OF MY CWA. I HAVE INCREASING CONCERNS THAT THIS COULD SET UP A VERY HEAVY RAIN EVENT MONDAY NIGHT...WITH STORMS POTENTIALLY TRAINING TO THE EAST NORTHEAST NEARLY PARALLEL TO THE SURFACE BOUNDARY. AT THIS TIME IT APPEARS THIS HEAVY RAIN THREAT COULD END UP SOUTH OF INTERSTATE 80 MONDAY NIGHT. HOWEVER...UNCERTAINTY IS STILL A BIT HIGH AS TO HOW FAR SOUTH THE SURFACE FRONT WILL GET MONDAY NIGHT...AND HENCE WHERE THE MOST FAVORED AREAS FOR TRAINING CELLS WILL OCCUR. AT THIS POINT...I HAVE ADDED HEAVY RAIN WORDING TO THE FORECAST...MAINLY FOR AREAS SOUTH OF INTERSTATE 80 INTO MONDAY NIGHT. FOLLOWING THIS ACTIVE WEATHER MONDAY NIGHT IT APPEARS THE WEATHER WILL BE DRY FOR THE MOST PART THROUGH LATE WEEK. THE MAIN STORY HOWEVER...WILL BE THE INCREASING HEAT BY THURSDAY. FORECAST GUIDANCE CONTINUES TO FORECAST MID LEVEL HEIGHTS TO BUILD SUBSTANTIALLY ACROSS THE CENTRAL CONUS. THIS COULD LEAD TO A RUN AT 90 TEMPERATURES FOR THURSDAY AS 850 MB TEMPERATURES WARM TO 20 TO 22C. I HAVE STARTED CUTTING BACK ON THE SLIGHT CHANCE POPS...ESPECIALLY ON WEDNESDAY AND WEDNESDAY NIGHT...BUT LEFT IN SOME SLIGHTS FOR THURSDAY. ALTHOUGH SOME ISOLATED CONVECTIVE ACTIVITY IS POSSIBLE DURING THIS TIME...IT APPEARS THAT THE BUILDING HEIGHTS AND WARMING TEMPS ALOFT COULD END UP CAPPING THE AREA...AND LIMITING THE THREAT FOR CONVECTIVE DEVELOPMENT THROUGH THURSDAY. CONVECTIVE CHANCES DO LOOK TO RETURN TO THE AREA AGAIN BY FRIDAY. ANOTHER SIGNIFICANT WAVE IS EXPECTED TO SHIFT EASTWARD ACROSS THE NORTHERN CONUS AND SOUTHERN CANADA LATE IN THE PERIOD...AND THIS LOOKS TO SHIFT A COLD FRONT SOUTHWARD ACROSS THE AREA SOMETIME EITHER FRIDAY OR FRIDAY NIGHT AND THIS COULD SPARK OFF ACTIVITY ACROSS THE AREA. COOLER WEATHER DOES LOOK TO OVERSPREAD TO AREA UNDER NORTHERLY WINDS BY EARLY NEXT WEEKEND. KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * CHANCE FOR A LAKE BREEZE/WIND SHIFT TO EASTERLY LATE SUNDAY AFTERNOON. KREIN/BMD //DISCUSSION...UPDATED 12Z... AS THE CLOUD SHIELD CLEARS OUT AND WITH CALM WINDS AND RESIDUAL LOW LEVEL MOISTURE IN PLACE...SOME PATCHY FOG/STRATUS HAS DEVELOPED. HOWEVER...WITH AMPLE SUNSHINE...EXPECT THAT THE FOG/STRATUS WILL QUICKLY DISSIPATE BY MID MORNING WITH VFR CONDITIONS EXPECTED THE REMAINDER OF THE DAY. WINDS SHOULD REMAIN LIGHT ENOUGH TO ALLOW A LAKE BREEZE TO DEVELOP...BUT THERE APPEARS TO BE LITTLE PUSH BEHIND THE BOUNDARY...SO AT THIS POINT...FEEL THAT CHANCES ARE LOW THAT THE LAKE BREEZE WILL PUSH INLAND OF ORD/MDW. HOWEVER...IF THE LAKE BREEZE DOES MANAGE TO PUSH WEST OF ORD/MDW...IT WOULD NOT BE UNTIL ARND 22-23Z AND ELY WINDS WOULD BE ARND 5-7KT. ANOTHER APPROACHING COLD FRONT WILL BRING INCREASING CHANCES FOR MORE SHOWERS AND THUNDERSTORMS BUT THIS WILL LIKELY NOT BE UNTIL AFTER 12Z TOMORROW. KREIN //ORD AND MDW CONFIDENCE...UPDATED 16Z... * MEDIUM TO HIGH CONFIDENCE IN LAKE BREEZE SUNDAY AFTERNOON...AND MEDIUM CONFIDENCE THAT THE BOUNDARY WILL NOT PUSH THROUGH ORD/MDW. * LOW CONFIDENCE IN TIMING TS TOMORROW. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. KREIN/BMD //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...CHANCE SHRA/TSRA. TUESDAY AND WEDNESDAY...VFR. WX NIL. THURSDAY THROUGH SATURDAY...PERIODIC CHANCES FOR SHRA/TSRA. KREIN && .MARINE... 300 AM CDT A PERIOD OF CHANGEABLE WEATHER...IN PARTICULAR...WIND DIRECTION...IS SETTING UP FOR THE NEXT SEVERAL DAYS. LOW PRESSURE JUST NORTH OF GEORGIAN BAY WILL TRACK EAST TO SOUTHERN QUEBEC BY LATE SUNDAY MORNING WHILE DRAGGING A WEAK COLD FRONT SOUTH ACROSS THE LAKE AND CLEARING THE SOUTH END OF LAKE MICHIGAN BY EARLY SUNDAY. THIS WILL SET UP A BRIEF PERIOD OF NWLY WINDS...BUT AS HIGH PRESSURE BUILDS OVER THE NORTHERN LAKES BEHIND THE FRONT SUNDAY AFTERNOON WINDS WILL BECOME LGT/VRBL FOR A SHORT TIME. SLY FLOW WILL RETURN TO THE LAKE SUNDAY NIGHT AND MONDAY...STRENGTHENING TO ARND 25KT AS ANOTHER LOW DEVELOPING OVER THE NORTHERN PLAINS DEEPENS WHILE TRACKING TO HUDSON BAY MONDAY NIGHT. THIS LOW WILL DRAG ANOTHER COLD FRONT SOUTH ACROSS LAKE MICHIGAN MONDAY NIGHT. WEAK HIGH PRESSURE WILL BUILD ACROSS THE LAKE TUESDAY BRINGING ANOTHER PERIOD OF LIGHT WINDS. BUT YET ANOTHER LOW IS EXPECTED TO MOVE OUT OF THE NORTHERN ROCKIES AND INTO THE NORTHERN PLAINS WEDNESDAY NIGHT...BRINGING ANOTHER PERIOD OF BRISK SOUTH WINDS TO THE LAKE FOR WEDNESDAY AND THURSDAY. THIS LOW IS FORECAST TO TRACK TO NEAR THE SOUTHERN TIP OF JAMES BAY DRAGGING ANOTHER COLD FRONT ACROSS THE LAKE FRIDAY OR FRIDAY NIGHT. ACCOMPANYING THESE FRONTAL PASSAGES WILL ALSO BE PERIODS OF THUNDERSTORMS AS WELL. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 948 AM CDT Sun Aug 31 2014 .UPDATE... ISSUED AT 948 AM CDT SUN AUG 31 2014 A low overcast persists across much of central Illinois along and east of a Peoria to Jacksonville line this morning. 1430z visible satellite imagery is showing thin spots developing in the cloud cover, so am expecting it to dissipate within the next 2 to 3 hours. HRRR ceiling forecast shows this trend quite nicely, resulting in a partly to mostly sunny afternoon. May see a few showers/thunder pop up along/south of I-70: however, areal coverage will remain spotty. Updated the forecast to better reflect sky cover trends this morning and to confine PoPs to just the far SE KILX CWA. && .SHORT TERM...(Today and tonight) ISSUED AT 358 AM CDT SUN AUG 31 2014 Shortwave trough and jet entrance region that brought banded convection and some locally heavy precipitation to central IL last evening has shifted northeastward with shower activity nearly ended over the ILX CWA. With clearing skies and good radiational cooling, patchy fog will continue to form overnight, mainly I-55 westward. Moist conditions with enough instability will remain through the afternoon today for a few showers and thunderstorms, mainly I-70 southeastward, but a relatively dry day expected. Highs in the mid 80s are expected. After sunset, convection should end quickly across the CWA with the loss of surface heating. Late in the night, chances for thunderstorms will spread back into west central Illinois as another cold front approaches from the west. && .LONG TERM...(Monday through Saturday) ISSUED AT 358 AM CDT SUN AUG 31 2014 SPC continues a slight risk (15+%) of severe thunderstorms across central IL nw of a Flora to Robinson line Monday afternoon/evening for damaging winds and large hail. This seems reasonable considering surface to 6 km bulk shear values of 30-40 kts, CAPES of 2-3k J/kg. Heavy rains also possible with thunderstorms in tropical airmass ahead of frontal boundary. Short waves and 30-40 kt low level jet moving into IL river valley later Sunday night into Monday morning and then spreading into eastern IL Monday afternoon/evening. Upper level trof over northern Rockies moves east into Midwest Monday/Monday night and drives a cold front southeast across central IL Monday night. Continued likely pops across much of area Monday afternoon into Monday night, though diminishing pops overnight Monday night nw of IL river. Best chances of showers and thunderstorms lingers over areas from I-72 south on Tue especially in the morning. The 5% risk of severe storms Tue is southeast of Lawrenceville. Quite warm and humid Monday ahead of front with highs 82-88F and dewpoints 70-75F and warmest temps in southeast IL where rain arrives later. Frontal boundary to weaken as it moves se into Ohio River valley Tue/Wed with near zonal upper level flow over the region. Carried just slight chance of convection during midweek from Tue night through Thu night. Highs in the low to mid 80s Tue/Wed climb into mid 80s to around 90F Thu/Fri as dewpoints rise back into the low to mid 70s with heat indices approaching 100F southern counties Thu/Fri afternoon. Next frontal boundary press southeast into IL Friday afternoon into Sat and bringing next best chances of showers and thunderstorms and cooler temps during next weekend. && .AVIATION...(For the 12Z TAFS through 12Z Monday morning) ISSUED AT 656 AM CDT SUN AUG 31 2014 Mainly IFR/MVFR visibilities this morning due to low ceilings and areas of fog. Expect improving conditions through 14Z with conditions generally becoming VFR as surface heating lifts ceilings and dissipates fog. Isold TSRA to continue until around 00Z mainly K1H2-KPRG southward with potential MVFR cig/vsby and gusty winds. After 00Z...TSRA ending with VFR conditions across central/SE Illinois. Toward 12Z Monday...potential TSRA development KIJX-KPIA westward depending on speed of approaching system, but probability of TSRA and associated flight category reductions too low probability before 12Z for mention in TAFS at this time. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BARNES SHORT TERM...ONTON LONG TERM...07 AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
303 AM CDT SUN AUG 31 2014 .DISCUSSION... 221 PM CDT SYNOPSIS...SCATTERED THUNDERSTORMS ARE POSSIBLE NW OF I-55 WHILE A LINE OF STORMS WILL IMPACT AREAS ALONG AND EAST OF I-55 THROUGH THIS EVENING. TOMORROW WILL BE DRY BUT UNSETTLED WEATHER RETURNS MONDAY WITH MULTIPLE CHANCES FOR THUNDERSTORMS. SEVERE STORMS ARE POSSIBLE MONDAY. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD WITH A COUPLE DAYS GETTING INTO THE MID 80S. THROUGH TONIGHT... AN UPPER LEVEL TROUGH IS OVER THE UPPER MISSISSIPPI RIVER VALLEY AND IT WILL PASS OVER THE REGION THROUGH THIS EVENING. A SURFACE LOW IS OVER THE NORTHERN END OF LAKE MI WITH ITS COLD FRONT EXTENDING THROUGH WI AND EASTERN IA. THE LOW WILL CONTINUE NE THROUGH THE NIGHT. HAVE MUCH HIGHER CONFIDENCE IN THE CONVECTIVE FORECAST TODAY COMPARED TO YESTERDAY DUE TO CLEAR FORCING MECHANISMS. EXPECTING TO HAVE TWO AREAS TO MONITOR. THE FIRST IS NORTHWEST OF I-55 WHERE ISOLATED TO SCATTERED STORMS WILL CONTINUE TO FESTER THROUGH THIS AFTERNOON AHEAD OF UPPER LEVEL WAVE AND COLD FRONT. THE BIGGER CONCERN WILL BE ALONG AND SE OF I-55 WHERE A LINE OF SHOWERS AND STORMS HAS ALREADY DEVELOPED. THE LATEST RAP ANALYSIS SHOWS A NICE CORRIDOR OF MOISTURE CONVERGENCE WHERE THE CONVECTION HAS FIRED. THE LATEST AMDAR SOUNDINGS ARE CAPLESS WITH 1000-1500 J/KG OF CAPE. HOWEVER...LAPSE RATES ARE POOR AND WIND SHEAR IS MINIMAL AT BEST. THE AMDAR SOUNDINGS DO HAVE LOW LEVEL INVERTED V/S AND THE RAP ANALYSIS HAS AROUND 1000 J/KG OF DOWNDRAFT CAPE. THEREFORE NOT EXPECTING WIDESPREAD SEVERE WEATHER...BUT A STORM OR TWO MAY PULSE UP AND PRODUCE SEVERE WINDS. HEAVY DOWNPOURS ARE ALSO EXPECTED WITH PWAT VALUES OF 1.6-1.8 INCHES. BASED ON SHORT TERM GUIDANCE...THE AREA MOST CONCERNING IS SOUTH OF A VALPARAISO IN TO GIBSON CITY IL LINE. STORMS WILL CONTINUE TO DEVELOP AND MOVE OVER THIS REGION WITH AMPLE FORCING. THEREFORE IF STORMS TRAIN OVER THE SAME AREA FOR AN EXTENDED PERIOD OF TIME...FLASH FLOODING MAY OCCUR. STORMS DIMINISH AND PUSH EAST OVERNIGHT WHILE HIGH PRESSURE SPREADS OVER THE REGION. WINDS WILL DIMINISH AND FOG IS POSSIBLE. SUNDAY... SUNDAY LOOKS DRY WITH HIGH PRESSURE OVER THE REGION. WE WILL BE IN THE NEXT LOW/S WARM SECTOR WITH 850MB TEMPS AROUND 18C. THEREFORE RAISED HIGH TEMPS INTO THE MID 80S AWAY FROM THE LAKE. THE WEAK PRESSURE GRADIENT WILL ALLOW A LAKE BREEZE TO FORM AND KEEP THE IL LAKEFRONT AROUND 80. GUIDANCE HAS SLOWED THE NEXT LOW SO PUSHED BACK POPS SUNDAY NIGHT. JEE MONDAY... UPPER WAVE DIGGING TOWARDS THE INTER-MOUNTAIN WEST THIS AFTERNOON WILL LIFT ACROSS THE PLAINS INTO THE UPPER MIDWEST ON MONDAY WITH ATTENDANT SURFACE LOW DEEPENING AS IT LIFTS ACROSS ONTARIO TO NEAR JAMES BAY BY LATE MONDAY. A SURFACE FRONT WILL SLOWLY PUSH ACROSS THE REGION MONDAY AND GUIDANCE HAS TRENDED TOWARDS A SLOWER SOLUTION OVER THE LAST 24 HOURS. MODERATE TO STRONG INSTABILITY IS PROGGED TO DEVELOP ALONG AND AHEAD OF THE FRONT WHERE THE GFS ADVERTISES A CORRIDOR OF JUST OVER 2000 J/KG MLCAPE JUST TO THE WEST OF THE CWA MONDAY AFTERNOON. THE BETTER CONVERGENCE ASSOCIATED WITH THE COLD FRONT MAY ARRIVE JUST PAST THE MOST FAVORABLE DIURNAL TIMING IF TIMING TRENDS HOLD TRUE...BUT THE RIGHT ENTRANCE REGION TO THE UPPER JET IS PROGGED TO MOVE OVER THE AREA BY MID TO LATE IN THE EVENING WITH DEEP LAYER SHEAR VALUES INCREASING TO AROUND 40 KT OR SO WHICH WOULD BE SUFFICIENT FOR AN ORGANIZED SEVERE WEATHER THREAT...THOUGH THIS THREAT SHOULD DIMINISH WEST TO EAST AS WE GET LATER INTO THE OVERNIGHT HOURS AND THE BOUNDARY LAYER STABILIZES. TUESDAY THROUGH THURSDAY... A SECONDARY SHORTWAVE TROUGH IS PROGGED TO PUSH ACROSS THE REGION ON TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWER AND THUNDERSTORMS MAINLY ACROSS SOUTH/SOUTHEASTERN PORTIONS OF THE CWA WHERE THE FRONTAL BOUNDARY MAY STILL SLOWLY BE MAKING A PUSH. MODERATE TO STRONG HEIGHTS RISES QUICKLY BUILD IN BEHIND THIS FEATURE THOUGH AND SHOULD RESULT IN A DRY WEATHER FOR MOST OF THE FORECAST AREA TUESDAY. THE GFS IS PARTICULAR IS HOLDING ONTO SOME POPS NORTH OF THE BOUNDARY WEDNESDAY INTO THURSDAY WHERE PERSISTENT WARM ADVECTION WILL RESULT IN MID LEVEL ASCENT...THOUGH THE ECMWF REMAINS DRY THIS PERIOD. WILL MAINTAIN SLIGHT CHANCE POPS IN THE MEANTIME. FRIDAY THROUGH SATURDAY... THERMAL RIDGE IS EXPECTED TO MOVE BACK OVERHEAD LATE IN THE WEEK WITH H85 TEMPS PUSHING INTO THE LOW 20C RANGE WHICH WILL LEAD TO ANOTHER WARM UP WITH TEMPS INTO THE UPPER 80S. ANOTHER SLOW MOVING COLD FRONT WILL THEN SAG SOUTH ACROSS THE REGION BRINGING RENEWED CHANCES FOR SHOWERS AND THUNDERSTORMS. DEUBELBEISS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SLIGHT CHANCE OF FOG/STRATUS EARLY SUNDAY MORNING. * CHANCE FOR A LAKE BREEZE/WIND SHIFT TO EASTERLY LATE SUNDAY AFTERNOON. KREIN //DISCUSSION...UPDATED 06Z... SCT TSRA WILL CONTINUE TONIGHT WELL TO THE SOUTHEAST OF THE TERMINALS OVER EAST CENTRAL IL AND WEST CENTRAL INDIANA. AN OLD BOUNDARY LIES JUST SOUTH OF THE TERMINALS WITH SLIGHTLY DRIER/LESS HUMID AIR TO THE NORTH...MOSTLY NOTABLE IN THE DEWPOINT GRADIENT. GIVEN THE LACK OF RAIN TODAY AND MIXING OUT OF LOW LEVEL MOISTURE...PLUS THE URBAN HEAT ISLAND EFFECTS...NOT ANTICIPATING FOG/STRATUS TO BE MUCH OF AN ISSUE FOR THE CHICAGO TERMINALS. HOWEVER...SHORT RANGE MODEL GUIDANCE IS STILL INDICATING A HIGH POSSIBILITY OF IFR CIGS/VSBY AWAY FROM THE HIGHLY URBANIZED AREAS...SO WILL MAINTAIN MVFR/IFR FOG AT THE MORE FOG PRONE OUTLYING TERMINALS...PARTICULARLY GYY/DPA/RFD. ANY VSBY RESTRICTIONS THAT DO FORM OVERNIGHT WILL QUICKLY DISSIPATE BY MID MORNING SUNDAY WITH VFR CONDITIONS EXPECTED THE REMAINDER OF THE DAY. WINDS SHOULD REMAIN LIGHT ENOUGH TO ALLOW A LAKE BREEZE TO DEVELOP...BUT THERE APPEARS TO BE LITTLE PUSH BEHIND THE BOUNDARY...SO AT THIS POINT...FEEL THAT CHANCES ARE LOW THAT THE LAKE BREEZE WILL PUSH INLAND OF ORD/MDW. HOWEVER...IF THE LAKE BREEZE DOES MANAGE TO PUSH WEST OF ORD/MDW...IT WOULD NOT BE UNTIL ARND 22-23Z AND ELY WINDS WOULD BE ARND 5-7KT. KREIN //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM-HIGH CONFIDENCE IN NO IFR AT ORD/MDW OVERNIGHT. * MEDIUM TO HIGH CONFIDENCE IN LAKE BREEZE SUNDAY AFTERNOON...AND MEDIUM CONFIDENCE THAT THE BOUNDARY WILL NOT PUSH THROUGH ORD/MDW. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. KREIN //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...PERIOD OR TWO OF SHRA/TSRA...STRONG TSRA POSSIBLE. TUESDAY AND WEDNESDAY...PREDOMINANTLY VFR. THURSDAY...SLIGHT CHANCE TSRA...OTHERWISE VFR. FRIDAY...CHANCE TSRA. IZZI && .MARINE... 300 AM CDT A PERIOD OF CHANGEABLE WEATHER...IN PARTICULAR...WIND DIRECTION...IS SETTING UP FOR THE NEXT SEVERAL DAYS. LOW PRESSURE JUST NORTH OF GEORGIAN BAY WILL TRACK EAST TO SOUTHERN QUEBEC BY LATE SUNDAY MORNING WHILE DRAGGING A WEAK COLD FRONT SOUTH ACROSS THE LAKE AND CLEARING THE SOUTH END OF LAKE MICHIGAN BY EARLY SUNDAY. THIS WILL SET UP A BRIEF PERIOD OF NWLY WINDS...BUT AS HIGH PRESSURE BUILDS OVER THE NORTHERN LAKES BEHIND THE FRONT SUNDAY AFTERNOON WINDS WILL BECOME LGT/VRBL FOR A SHORT TIME. SLY FLOW WILL RETURN TO THE LAKE SUNDAY NIGHT AND MONDAY...STRENGTHENING TO ARND 25KT AS ANOTHER LOW DEVELOPING OVER THE NORTHERN PLAINS DEEPENS WHILE TRACKING TO HUDSON BAY MONDAY NIGHT. THIS LOW WILL DRAG ANOTHER COLD FRONT SOUTH ACROSS LAKE MICHIGAN MONDAY NIGHT. WEAK HIGH PRESSURE WILL BUILD ACROSS THE LAKE TUESDAY BRINGING ANOTHER PERIOD OF LIGHT WINDS. BUT YET ANOTHER LOW IS EXPECTED TO MOVE OUT OF THE NORTHERN ROCKIES AND INTO THE NORTHERN PLAINS WEDNESDAY NIGHT...BRINGING ANOTHER PERIOD OF BRISK SOUTH WINDS TO THE LAKE FOR WEDNESDAY AND THURSDAY. THIS LOW IS FORECAST TO TRACK TO NEAR THE SOUTHERN TIP OF JAMES BAY DRAGGING ANOTHER COLD FRONT ACROSS THE LAKE FRIDAY OR FRIDAY NIGHT. ACCOMPANYING THESE FRONTAL PASSAGES WILL ALSO BE PERIODS OF THUNDERSTORMS AS WELL. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
102 AM CDT SUN AUG 31 2014 .DISCUSSION... 221 PM CDT SYNOPSIS...SCATTERED THUNDERSTORMS ARE POSSIBLE NW OF I-55 WHILE A LINE OF STORMS WILL IMPACT AREAS ALONG AND EAST OF I-55 THROUGH THIS EVENING. TOMORROW WILL BE DRY BUT UNSETTLED WEATHER RETURNS MONDAY WITH MULTIPLE CHANCES FOR THUNDERSTORMS. SEVERE STORMS ARE POSSIBLE MONDAY. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD WITH A COUPLE DAYS GETTING INTO THE MID 80S. THROUGH TONIGHT... AN UPPER LEVEL TROUGH IS OVER THE UPPER MISSISSIPPI RIVER VALLEY AND IT WILL PASS OVER THE REGION THROUGH THIS EVENING. A SURFACE LOW IS OVER THE NORTHERN END OF LAKE MI WITH ITS COLD FRONT EXTENDING THROUGH WI AND EASTERN IA. THE LOW WILL CONTINUE NE THROUGH THE NIGHT. HAVE MUCH HIGHER CONFIDENCE IN THE CONVECTIVE FORECAST TODAY COMPARED TO YESTERDAY DUE TO CLEAR FORCING MECHANISMS. EXPECTING TO HAVE TWO AREAS TO MONITOR. THE FIRST IS NORTHWEST OF I-55 WHERE ISOLATED TO SCATTERED STORMS WILL CONTINUE TO FESTER THROUGH THIS AFTERNOON AHEAD OF UPPER LEVEL WAVE AND COLD FRONT. THE BIGGER CONCERN WILL BE ALONG AND SE OF I-55 WHERE A LINE OF SHOWERS AND STORMS HAS ALREADY DEVELOPED. THE LATEST RAP ANALYSIS SHOWS A NICE CORRIDOR OF MOISTURE CONVERGENCE WHERE THE CONVECTION HAS FIRED. THE LATEST AMDAR SOUNDINGS ARE CAPLESS WITH 1000-1500 J/KG OF CAPE. HOWEVER...LAPSE RATES ARE POOR AND WIND SHEAR IS MINIMAL AT BEST. THE AMDAR SOUNDINGS DO HAVE LOW LEVEL INVERTED V/S AND THE RAP ANALYSIS HAS AROUND 1000 J/KG OF DOWNDRAFT CAPE. THEREFORE NOT EXPECTING WIDESPREAD SEVERE WEATHER...BUT A STORM OR TWO MAY PULSE UP AND PRODUCE SEVERE WINDS. HEAVY DOWNPOURS ARE ALSO EXPECTED WITH PWAT VALUES OF 1.6-1.8 INCHES. BASED ON SHORT TERM GUIDANCE...THE AREA MOST CONCERNING IS SOUTH OF A VALPARAISO IN TO GIBSON CITY IL LINE. STORMS WILL CONTINUE TO DEVELOP AND MOVE OVER THIS REGION WITH AMPLE FORCING. THEREFORE IF STORMS TRAIN OVER THE SAME AREA FOR AN EXTENDED PERIOD OF TIME...FLASH FLOODING MAY OCCUR. STORMS DIMINISH AND PUSH EAST OVERNIGHT WHILE HIGH PRESSURE SPREADS OVER THE REGION. WINDS WILL DIMINISH AND FOG IS POSSIBLE. SUNDAY... SUNDAY LOOKS DRY WITH HIGH PRESSURE OVER THE REGION. WE WILL BE IN THE NEXT LOW/S WARM SECTOR WITH 850MB TEMPS AROUND 18C. THEREFORE RAISED HIGH TEMPS INTO THE MID 80S AWAY FROM THE LAKE. THE WEAK PRESSURE GRADIENT WILL ALLOW A LAKE BREEZE TO FORM AND KEEP THE IL LAKEFRONT AROUND 80. GUIDANCE HAS SLOWED THE NEXT LOW SO PUSHED BACK POPS SUNDAY NIGHT. JEE MONDAY... UPPER WAVE DIGGING TOWARDS THE INTER-MOUNTAIN WEST THIS AFTERNOON WILL LIFT ACROSS THE PLAINS INTO THE UPPER MIDWEST ON MONDAY WITH ATTENDANT SURFACE LOW DEEPENING AS IT LIFTS ACROSS ONTARIO TO NEAR JAMES BAY BY LATE MONDAY. A SURFACE FRONT WILL SLOWLY PUSH ACROSS THE REGION MONDAY AND GUIDANCE HAS TRENDED TOWARDS A SLOWER SOLUTION OVER THE LAST 24 HOURS. MODERATE TO STRONG INSTABILITY IS PROGGED TO DEVELOP ALONG AND AHEAD OF THE FRONT WHERE THE GFS ADVERTISES A CORRIDOR OF JUST OVER 2000 J/KG MLCAPE JUST TO THE WEST OF THE CWA MONDAY AFTERNOON. THE BETTER CONVERGENCE ASSOCIATED WITH THE COLD FRONT MAY ARRIVE JUST PAST THE MOST FAVORABLE DIURNAL TIMING IF TIMING TRENDS HOLD TRUE...BUT THE RIGHT ENTRANCE REGION TO THE UPPER JET IS PROGGED TO MOVE OVER THE AREA BY MID TO LATE IN THE EVENING WITH DEEP LAYER SHEAR VALUES INCREASING TO AROUND 40 KT OR SO WHICH WOULD BE SUFFICIENT FOR AN ORGANIZED SEVERE WEATHER THREAT...THOUGH THIS THREAT SHOULD DIMINISH WEST TO EAST AS WE GET LATER INTO THE OVERNIGHT HOURS AND THE BOUNDARY LAYER STABILIZES. TUESDAY THROUGH THURSDAY... A SECONDARY SHORTWAVE TROUGH IS PROGGED TO PUSH ACROSS THE REGION ON TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWER AND THUNDERSTORMS MAINLY ACROSS SOUTH/SOUTHEASTERN PORTIONS OF THE CWA WHERE THE FRONTAL BOUNDARY MAY STILL SLOWLY BE MAKING A PUSH. MODERATE TO STRONG HEIGHTS RISES QUICKLY BUILD IN BEHIND THIS FEATURE THOUGH AND SHOULD RESULT IN A DRY WEATHER FOR MOST OF THE FORECAST AREA TUESDAY. THE GFS IS PARTICULAR IS HOLDING ONTO SOME POPS NORTH OF THE BOUNDARY WEDNESDAY INTO THURSDAY WHERE PERSISTENT WARM ADVECTION WILL RESULT IN MID LEVEL ASCENT...THOUGH THE ECMWF REMAINS DRY THIS PERIOD. WILL MAINTAIN SLIGHT CHANCE POPS IN THE MEANTIME. FRIDAY THROUGH SATURDAY... THERMAL RIDGE IS EXPECTED TO MOVE BACK OVERHEAD LATE IN THE WEEK WITH H85 TEMPS PUSHING INTO THE LOW 20C RANGE WHICH WILL LEAD TO ANOTHER WARM UP WITH TEMPS INTO THE UPPER 80S. ANOTHER SLOW MOVING COLD FRONT WILL THEN SAG SOUTH ACROSS THE REGION BRINGING RENEWED CHANCES FOR SHOWERS AND THUNDERSTORMS. DEUBELBEISS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SLIGHT CHANCE OF FOG/STRATUS EARLY SUNDAY MORNING. * CHANCE FOR A LAKE BREEZE/WIND SHIFT TO EASTERLY LATE SUNDAY AFTERNOON. KREIN //DISCUSSION...UPDATED 06Z... SCT TSRA WILL CONTINUE TONIGHT WELL TO THE SOUTHEAST OF THE TERMINALS OVER EAST CENTRAL IL AND WEST CENTRAL INDIANA. AN OLD BOUNDARY LIES JUST SOUTH OF THE TERMINALS WITH SLIGHTLY DRIER/LESS HUMID AIR TO THE NORTH...MOSTLY NOTABLE IN THE DEWPOINT GRADIENT. GIVEN THE LACK OF RAIN TODAY AND MIXING OUT OF LOW LEVEL MOISTURE...PLUS THE URBAN HEAT ISLAND EFFECTS...NOT ANTICIPATING FOG/STRATUS TO BE MUCH OF AN ISSUE FOR THE CHICAGO TERMINALS. HOWEVER...SHORT RANGE MODEL GUIDANCE IS STILL INDICATING A HIGH POSSIBILITY OF IFR CIGS/VSBY AWAY FROM THE HIGHLY URBANIZED AREAS...SO WILL MAINTAIN MVFR/IFR FOG AT THE MORE FOG PRONE OUTLYING TERMINALS...PARTICULARLY GYY/DPA/RFD. ANY VSBY RESTRICTIONS THAT DO FORM OVERNIGHT WILL QUICKLY DISSIPATE BY MID MORNING SUNDAY WITH VFR CONDITIONS EXPECTED THE REMAINDER OF THE DAY. WINDS SHOULD REMAIN LIGHT ENOUGH TO ALLOW A LAKE BREEZE TO DEVELOP...BUT THERE APPEARS TO BE LITTLE PUSH BEHIND THE BOUNDARY...SO AT THIS POINT...FEEL THAT CHANCES ARE LOW THAT THE LAKE BREEZE WILL PUSH INLAND OF ORD/MDW. HOWEVER...IF THE LAKE BREEZE DOES MANAGE TO PUSH WEST OF ORD/MDW...IT WOULD NOT BE UNTIL ARND 22-23Z AND ELY WINDS WOULD BE ARND 5-7KT. KREIN //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM-HIGH CONFIDENCE IN NO IFR AT ORD/MDW OVERNIGHT. * MEDIUM TO HIGH CONFIDENCE IN LAKE BREEZE SUNDAY AFTERNOON...AND MEDIUM CONFIDENCE THAT THE BOUNDARY WILL NOT PUSH THROUGH ORD/MDW. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. KREIN //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...PERIOD OR TWO OF SHRA/TSRA...STRONG TSRA POSSIBLE. TUESDAY AND WEDNESDAY...PREDOMINANTLY VFR. THURSDAY...SLIGHT CHANCE TSRA...OTHERWISE VFR. FRIDAY...CHANCE TSRA. IZZI && .MARINE... 221 PM CDT MODERATE SOUTHWEST FLOW IS CURRENTLY IN PLACE ACROSS LAKE MICHIGAN WHERE SOUTHWEST WINDS ARE GUSTING 20 TO 25 KTS WITH OCCASIONAL 30 KT WINDS. A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THE NEARSHORE WATERS THROUGH LATE THIS EVENING. THIS IS AHEAD OF LOW PRESSURE CURRENTLY CENTERED NEAR GREEN BAY. THE LOW WILL DRAG A COLD FRONT SOUTH ACROSS LAKE MICHIGAN TONIGHT TURNING WINDS TO THE NORTHWEST. WINDS WILL ABATE BRIEFLY AS TRANSIENT HIGH PRESSURE PUSHES ACROSS THE NORTHERN LAKES REGION...BUT BY MIDDAY SUNDAY WINDS ARE EXPECTED TO BEGIN TO TURN SOUTHEAST AND START TO RAMP UP AGAIN AHEAD OF ANOTHER AREA OF LOW PRESSURE. THIS NEXT WILL LOW LIFT FROM THE NORTHERN PLAINS...DEEPENING AS IT HEADS TO HUDSON BAY MONDAY NIGHT INTO TUESDAY. SOUTH WINDS ARE EXPECTED TO PEAK MONDAY OVER THE LAKE WITH GUSTS SOLIDLY INTO THE 20 KT RANGE...APPROACHING 30 KT OVER THE NORTH END OF THE LAKE. ANOTHER COLD FRONT WILL SAG SOUTH ACROSS LAKE MICHIGAN MONDAY NIGHT. DEUBELBEISS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1251 AM EDT SUN AUG 31 2014 .SYNOPSIS... ISSUED AT 1250 AM EDT SUN AUG 31 2014 SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL REMAIN POSSIBLE THIS MORNING ALONG A WEAK FRONTAL BOUNDARY. DRIER AIR WILL FILTER INTO THE AREA LATER TODAY INTO TONIGHT AS HIGH PRESSURE BRIEFLY BUILDS INTO THE GREAT LAKES REGION. A COLD FRONT WILL PUSH IN FROM THE WEST MONDAY INTO MONDAY EVENING BRINGING RENEWED CHANCES FOR SHOWERS AND THUNDERSTORMS. HIGHS WILL REACH INTO THE UPPER 70S TO LOWS 80 TODAY AND THE LOW TO MID 80S ON MONDAY. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 335 PM EDT SAT AUG 30 2014 CONVECTIVE DEVELOPMENT HAS TRIGGERED WHERE THE CLOUDS CLEARED EARLIER TODAY...MAINLY OVER CENTRAL ILLINOIS TO LOWER LAKE MICHIGAN AND INTO NORTHERN MICHIGAN. BEST SYNOPTIC SCALE FORCING ASSOCIATED WITH THE LOW/TROF IN WISCONSIN. FLOW REGIME IS SUCH THAT THE CONVECTION HAS DEVELOPED IN A STRETCHING DEFORMATION AXIS. HRRR AND LOCAL WRF SHOW THE SFC BASED FRONTOGENESIS IN THIS AXIS... LAPSE RATES AND WIND PROFILES SUPPORT THE POTENTIAL FOR CONVECTIVE LINES AND INDIVIDUAL LINE SEGMENTS. ISOLATED THREAT FOR SEVERE WIND GUSTS. DO NOT EXPECT TO SEE SUSTAINED CONVECTIVE DEVELOPMENT AS THE BOUNDARY LAYER FORCING DOES NOT PERSIST MUCH PAST 04Z. LOW LEVEL JET KICKS IN OVERNIGHT AND THIS SHOULD BE ENOUGH TO SUSTAIN MORE ORGANIZED SHRA/TSRA ACROSS THE SOUTHEASTERN HALF OF THE FORECAST AREA. WHILE THERE IS DISCREPANCY IN TIMING AND INTENSITY BETWEEN THE MODELS...THE BOUNDARY LAYER CAPE AND WIND PROFILES ARE VERY SIMILAR AND DO SUPPORT PERSISTENT/LINGERING SHOWERS THROUGH SUNDAY MORNING. WITH ABUNDANT MOISTURE TAP AND A LONG FETCH OF ISENTROPIC ASSENT...SOME OF THE SHOWERS COULD PRODUCE MODERATE TO LOCALLY HEAVY RAINFALL. AS THE LOW LEVEL JET DECREASES AND THE TROF/DEFORMATION AXIS SHIFTS EASTWARD...EXPECT IMPROVING CONDITIONS DURING THE DAY SUNDAY AHEAD OF ANOTHER MORE ROBUST SYNOPTIC SYSTEM APPROACHING THE AREA FOR MONDAY. && .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 335 PM EDT SAT AUG 30 2014 MAIN FOCUS OF LONG TERM IS ON PRECIP/SEVERE WEATHER CHANCES MONDAY INTO MONDAY NIGHT. WELL DEFINED MID/UPPER LEVEL TROUGH CURRENTLY DIGGING INTO THE PACIFIC NORTHWEST WILL SWING THROUGH THE GREAT LAKES LATE MONDAY. TROUGH WILL BE LIFTING AS IT MOVES THROUGH THE REGION BUT STRONG PUSH OF HEIGHT FALLS AND CVA WILL SUPPORT A DECENT SURFACE CYCLONE AND ATTENDANT COLD FRONT. PRECIP CHANCES WILL BE FURTHER AIDED BY GOOD RIGHT ENTRANCE JET DYNAMICS OVER THE SOUTHERN GREAT LAKES. DEEP AND STRONG SOUTHWEST FLOW AHEAD OF THE TROUGH WILL EASILY ADVECT HIGH THETA-E AIRMASS BACK INTO OUR AREA ON MONDAY. AFTERNOON SBCAPE VALUES EXPECTED TO REACH THE 2-3 KJ/KG RANGE AS HIGH TEMPS CLIMB INTO THE MID...OR PERHAPS UPPER...80S WITH SURFACE DEWPOINTS IN THE LOW 70S. VERY DYNAMIC WAVE WILL LIKELY SUPPORT NUMEROUS SHOWERS AND THUNDERSTORMS BUT TIMING WILL BE CRITICAL TO SEVERE WEATHER CHANCES. LATEST 12Z NWP SUITE KEEPS SURFACE BOUNDARY WEST OF OUR CWA UNTIL TUESDAY MORNING. ISO/SCT CONVECTION MAY DEVELOP IN THE WARM SECTOR MONDAY AFTERNOON ALONG WEAK PREFRONTAL TROUGH AS SUGGESTED BY THE LATEST NAM12 BUT EXPECT BULK OF THE ACTIVITY WILL BE TIED TO THE ACTUAL COLD FRONT LATE MONDAY NIGHT. BETTER WIND PROFILES...WITH 0-6KM SHEAR OF 30+ KNOTS...WILL ALSO BE TIED CLOSER TO THE FRONT. DESPITE MORE THAN ADEQUATE SHEAR...MIDLEVEL LAPSE RATES OF 6-7 C/KM ARE ONLY WEAKLY SUPPORTIVE OF A NOCTURNAL SEVERE WEATHER THREAT. FORECAST SOUNDINGS INDICATE ONLY AROUND 1000 J/KG OF ELEVATED INSTABILITY MONDAY NIGHT....PLENTY FOR WIDESPREAD THUNDERSTORMS BUT SEVERE POTENTIAL IS LESS CLEAR. THERE WILL BE A THREAT FOR SEVERE WINDS...AND POTENTIAL ROTATION...WITH ANY SUBSTANTIVE UPDRAFTS THAT MANAGE TO DEVELOP BUT LATE ARRIVAL OF FRONT MAY LIMIT CHANCES FOR A WIDESPREAD SEVERE WEATHER EVENT. PUSHED BACK TIMING OF POPS BUT ALSO INCREASED THEM A BIT BASED ON LATEST MODEL SOLUTIONS. COULD ALSO BE A THREAT FOR STRONGER STORMS IN OUR FAR SOUTHEAST COUNTIES LATE TUESDAY MORNING IF SURFACE BOUNDARY IS SLOW ENOUGH TO EXIT THE CWA. QUIET WEATHER EXPECTED MIDWEEK BEFORE ANOTHER TROUGH APPROACHES NEXT WEEKEND. SCT CONVECTION MAY BE POSSIBLE THURSDAY INTO FRIDAY AS WARM FRONT LIFTS NORTH ONCE AGAIN BUT BEST CHANCES LOOK TO HOLD OFF UNTIL THE WEEKEND. AFTER A BRIEF BREAK TUES AND WED...HEAT AND HUMIDITY WILL RETURN FOR THE END OF THE WEEK AS ACTIVE WEATHER PATTERN CONTINUES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1250 AM EDT SUN AUG 31 2014 HIGH BOUNDARY LAYER MOISTURE AND WEAK CONVERGENCE INVOF OF A SFC TROUGH WILL ALLOW CIGS TO LOWER INTO MAINLY IFR-LOW MVFR THIS MORNING. BROKEN/POORLY ORGANIZED CONVECTIVE LINE ALONG THIS SFC TROUGH WILL SAG SLOWLY SSE INTO THE KFWA AREA THIS MORNING/EARLY AFTERNOON. OPTED FOR A VCSH MENTION FOR NOW GIVEN UNCERTAINTY/WEAK FORCING. PCPN SHOULD REMAIN SOUTH/EAST OF KSBN WITH POTENTIAL FOR FOG/LIFR CONDITIONS TO FILL IN TOWARD DAYBREAK. CONDITIONS SHOULD GRADUALLY IMPROVE TO VFR THIS AFTERNOON. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...STEINWEDEL SHORT TERM...LEWIS LONG TERM...AGD AVIATION...STEINWEDEL VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
314 PM CDT SUN AUG 31 2014 .SYNOPSIS... ISSUED AT 313 PM CDT SUN AUG 31 2014 A WARM...MID SUMMER-LIKE DAY IS FOUND OVER OUR CWA TODAY AS WE REMAIN WELL EAST OF THE COLD FRONT APPROACHING IOWA THIS AFTERNOON. THE COLD FRONT IS SLOWLY MOVING EAST...AND HAS ALREADY SPAWNED A FEW HIGH BASED THUNDERSTORMS FROM SOUTHERN MN TO FAR EASTERN NE. TEMPERATURES WITH FULL SUN TODAY HAVE REACHED THE MID 80S AS OF 2 PM...AND APPEAR SET FOR HIGHS IN THE MID TO UPPER 80S BEFORE CLOUDS INTERRUPT THE HEATING LATER THIS AFTERNOON. SURFACE BASED STORMS REMAIN CAPPED FOR NOW...THOUGH CAPE VALUES ARE SHOWN ON RAP DATA TO BE 2000 TO 4000 J/KG. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 313 PM CDT SUN AUG 31 2014 THERE IS LITTLE DOUBT THERE WILL BE AN IMPRESSIVE CONVECTIVE EVENT TONIGHT. THERE IS PLENTY OF DOUBT THAT IT WILL STRONGLY AFFECT MORE THAN JUST THE WESTERN MOST PORTION OF OUR CWA. THE SLOW MOVING FRONT SHOULD BE ENOUGH TO FOCUS STORMS WITH PLENTY OF CAPE AND MOISTURE AVAILABLE TO THE WEST...LIKELY NEAR THE MISSOURI RIVER. THEY SHOULD MOVE EAST...SLOWLY. THIS PLACES THE WEAKENING PHASE OF THE COMPLEX INTO EASTERN IOWA BETWEEN MIDNIGHT AND 9 AM MONDAY. THIS POOR DIURNAL TIMING COMBINED WITH LESS THAN IDEAL MOISTURE TRANSPORT DURING THAT TIME FRAME SUGGESTS BOTH INTENSITY AND COVERAGE OF STORMS WILL BE ON THE WANE IN THAT PERIOD. I HAVE CONFINED HIGH POPS TO ONLY THE WESTERN CWA LATE TONIGHT...AND LOWERED TO CHANCE FOR MONDAY MORNING SINCE MOST MODELS SUGGEST A FRAGMENTED LINE...AND THAT SEEMS MOST LIKELY TO ME AS WELL. QPF SHOULD BE IMPRESSIVE TO THE WEST...BUT MAY BE INSIGNIFICANT IN OUR CWA...GENERALLY 0.25 OR LESS IN ALL BE THE FAR WEST...WHERE 0.5 TO 1.0 IS POSSIBLE. MONDAY WILL SEE FAR BETTER DYNAMICS...THUS THE SPC OUTLOOK FOR SEVERE WEATHER. HOWEVER...THE CONVERGENT OUTFLOW BOUNDARY WILL LIKELY BE WELL IN ADVANCE OF THE COLD FRONT...WHICH SHOULD ALSO DEFLECT THE STRONGEST HEATING WELL EAST OF THE CWA AS WELL. THUS...THE WEAKENING CONVECTIVE DEBRIS SHOULD INHIBIT OUR MONDAY SEVERE POTENTIAL...AS WELL AS WIDESPREAD RAIN POTENTIAL AGAIN. SURE SEEMS THIS EVENT SHOULD PRODUCE THE MAJORITY OF ITS RAIN WEST AND SOUTHEAST OF OUR CWA. ERVIN .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 313 PM CDT SUN AUG 31 2014 THE FRONT WILL CLEAR THE SOUTHEAST HALF OF THE AREA LATE MONDAY EVENING. THE SOUTHEAST HALF OF THE AREA SHOULD SEE PRECIPITATION ONGOING AT SUNSET THAT ENDS FROM NORTHWEST TO SOUTHEAST AFTER MIDNIGHT. DRIER AIR MOVING INTO THE AREA SHOULD RESULT IN LOWS NEAR OR SLIGHTLY BELOW NORMAL BY SUNRISE TUESDAY. TUESDAY/TUESDAY NIGHT DRY CONDITIONS ARE EXPECTED AS HIGH PRESSURE MOVES THROUGH THE MIDWEST. TEMPERATURES SHOULD BE CLOSE TO NORMAL. WEDNESDAY MORNING LOOKS TO BE DRY ACROSS THE AREA AS THE HIGH MOVES TOWARD THE EAST COAST. A WEAK DISTURBANCE WILL MOVE THROUGH THE AREA WEDNESDAY AFTERNOON. THE OVERALL FORCING IS NOT STRONG AND MOISTURE AVAILABILITY IS IN QUESTION. IF PRECIPITATION DOES OCCUR IT WOULD BE ISOLATED IN NATURE WITH THE SOUTH HALF BEING FAVORED. WEDNESDAY NIGHT ON... THE MODEL CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS IN EACH 12 HR PERIOD FROM WEDNESDAY NIGHT THROUGH SATURDAY. THERE IS A WEAK DISTURBANCE MOVING THROUGH THE AREA WEDNESDAY NIGHT/THURSDAY. MOISTURE AVAILABILITY WILL BE ON THE INCREASE BUT THE OVERALL FORCING IS NOT STRONG. THE POSSIBILITY DOES EXIST THERE WILL BE PERIODS OF DRY WEATHER WEDNESDAY NIGHT/THURSDAY. THE MODELS DIFFER SOMEWHAT ON THE TIMING BUT AGREE THAT ANOTHER COLD FRONT WILL MOVE THROUGH THE AREA IN THE THURSDAY NIGHT THROUGH FRIDAY NIGHT TIME FRAME. SEVERAL MODELS ARE PUSHING A SIGNIFICANT HIGH INTO THE WESTERN GREAT LAKES ON SATURDAY. THE CURRENT MODEL CONSENSUS HAS SLIGHT CHANCE POPS ACROSS THE SOUTH QUARTER OF THE AREA BUT THE OVERALL TREND IS SUGGESTING DECREASING PRECIPITATION CHANCES. SATURDAY NIGHT THROUGH SUNDAY THE MODEL CONSENSUS HAS DRY CONDITIONS WITH HIGH PRESSURE OVER THE GREAT LAKES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1225 PM CDT SUN AUG 31 2014 CLEAR SKIES AND SOUTHERLY WINDS AROUND 12 KTS WILL CONTINUE THIS AFTERNOON...WITH AN EVENTUAL INCREASE IN MID AND HIGH CLOUDS TOWARD EVENING AS A COLD FRONT APPROACHES FROM THE WEST. THIS FRONT WILL BRING WIDESPREAD THUNDERSTORMS TO THE PLAINS...THROUGH CENTRAL IOWA AND SOUTHERN MINNESOTA THIS AFTERNOON AND EVENING. HOWEVER...THE LINE OF STORMS SHOULD WEAKEN BELOW SEVERE LEVELS LATE THIS EVENING AS IT APPROACHES EASTERN IOWA. A PERIOD OF THUNDERSTORMS AND RAIN IS LIKELY AT DBQ AND CID AS THIS LINE MOVES EAST. FARTHER SOUTHEAST...THE LINE OF STORMS MAY BREAK UP INTO SCATTERED SHOWERS...THUS A PROB30 PERIOD OF STORMS IS INCLUDED AT MLI AND BRL. AFTER STORMS ROLL EAST MONDAY MORNING...A PERIOD OF MVFR CIGS IS EXPECTED AT ALL SITES. ERVIN && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...ERVIN SHORT TERM...ERVIN LONG TERM...08 AVIATION...ERVIN
AREA FORECAST DISCUSSION
NWS TOPEKA KS
655 PM CDT Mon Sep 1 2014 ...Update to aviation forecast discussion... .SHORT TERM...(This Evening through Tuesday) Issued at 319 PM CDT MON SEP 1 2014 Quick cyclonic upper flow remains in place with the core of last night`s wave already in the Great Lakes and another weaker wave coming into the High Plains per recent water vapor imagery. The cold front`s location is hard to nail down behind outflow from the overnight convection and weak pressure fields, but appears to be bisecting the local area from southwest to northeast. Lower cloud under a modest inversion has been rather prevalent today, keeping temps in the 70s. Modest convergence persists in east central Kansas this afternoon. With still some CIN remaining per RAP analysis, confirmed by recent visible satellite imagery, and the western upper wave staying well north, storm chances don`t look great, but will maintain some mention ahead of the front in east central Kansas, diminishing with time as weak high pressure continues to move across northern sections of the state. There are some breaks in the clouds to the south, and some increase in instability is anticipated for the next few hours. Deep layer is not very high in the weak low level wind fields, but hard to completely rule out with mixed layer CAPE likely rising to near 1500 J/kg. As the surface high builds in, winds should be rather light, and depending on cloud trends particularly with convection, a fairly good setup for radiational fog will be in place with cloudy skies and limited mixing today and low cloud scouring out following the recent heavy rain. Will go ahead with some patchy fog mention at this point and let later shifts watch trends. Storm chances continue to look like Tuesday but with the boundary again possibly not far south, will keep a small chance near it. Better mixing and insolation should yield highs back into the 80s. .LONG TERM...(Tuesday Night through Monday) Issued at 319 PM CDT MON SEP 1 2014 Models continue to show the potential for elevated thunderstorms and large hail Tuesday night. The one wrinkle is the NAM appears to be quite a bit stronger in magnitude for both the elevated instability and effective shear. There is still good theta-e advection along the nose of the low level jet as well as isentropic upglide, so I think there should be some storms over eastern KS. The question is whether they will be strong enough to produce severe hail. Have continued with a chance POP through the night and think the potential still exists for some severe storms. It just may be more marginal than the NAM would suggest. With the exception of some elevated precip possibly lingering through the morning Wednesday, the forecast should quiet down as the models keep the jet stream and synoptic scale energy north of the forecast through Thursday morning. By Thursday night, a frontal system is projected to begin moving into the area. There is some uncertainty in the timing of the frontal system as most solutions have trended faster with the front, the NAM being the fastest. For now I`ve not made many changes from the previous forecast thinking the front would move through mainly Friday and Friday evening with the higher chances for precip in these periods. However if the faster trend continues, the POPs may need to be pushed up in the forecast as well. Have continued to trend POPs down for Saturday and kept a dry forecast for Sunday with models showing surface ridging and relatively dryer air over KS. By Monday, there is some disagreement with the GFS and ECMWF in the amplification of an upper trough across the west. Because the GFS is the more amplified solution, it is quick to set up return flow with the potential for shortwaves within southwesterly flow aloft to pass near the area. Have taken a conservative approach with the forecast at this time and have introduced only a slight chance for precip on Monday until there is a little more agreement in solutions. Temps will remain quite warm Wednesday and Thursday as the models show the thermal ridge over portions of the state. Because of this have continued with highs in the 90s and lows from around 70 to the mid 70s. Cold air advection is expected to increase Thursday night as the front moves through the area. This should bring a cool down for the weekend with highs in the 70s and lows in the 50s to around 60. && .AVIATION...(For the 00Z TAFs through 00Z Tuesday Evening) Issued at 634 PM CDT MON SEP 1 2014 Fog at the taf sites later tonight will be the biggest issue with this forecast period. The low stratus deck which has been around this afternoon is very slow to progress anywhere. Current satellite image shows higher cumulus building northward from south central KS so clearing may be delayed. Also elevated showers are possible this evening as evident from latest radar although the models were much further south. These showers could approach MHK in the next hour. If the clouds are able to clear out later this evening then the potential for dense fog will be higher. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...65 LONG TERM...Wolters AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1221 PM CDT SUN AUG 31 2014 ...UPDATED AVIATION SECTION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 333 AM CDT SUN AUG 31 2014 THE HRRR WAS INDICATING A BROKEN LINE OF RELATIVELY LIGHT REFLECTIVITY MOVING EASTWARD FROM THE AFOREMENTIONED DEVELOPMENT ZONE INTO CENTRAL KS BY AROUND 10-12 UTC. THIS SOLUTION WAS FOLLOWED WITH BASICALLY LOW POPS BELOW 20 PERCENT. THE MORE SIGNIFICANT ISSUE FOR THE DAY WILL BE A LATE DAY OR EVENING SEVERE WEATHER THREAT. THE NMM AND ARW MODEL RUNS DEVELOPED A QLCS TYPE BOWING SEGMENT ACROSS NORTHERN KS, ALONG AND AHEAD OF A COLD FRONT/DRYLINE INTERSECTION OVER NORTHERN KS. FARTHER SOUTH, OVER OUR AREA, ANY CONVECTION IN THESE SOLUTIONS COULD BE GENERALLY MORE DISCREET AND MORE HIGH BASED (HAIL AND WIND THREATS POSSIBLE) WITH SUFFICIENT SHEAR FOR SUPERCELLS. HOWEVER, IT IS POSSIBLE OUTFLOWS/COLD POOLS COULD FORCE MORE WIDESPREAD DEVELOPMENT FARTHER BRINGING MORE OF OUR AREA INTO A SEVERE WEATHER THREAT. SURFACE WINDS WILL BE MORE BREEZY AHEAD OF THE DRYLINE THIS AFTERNOON. MODELS SUGGEST 15 TO 20 KNOTS SUSTAINED WINDS WILL BE COMMON WITH GUSTS IN TO JUST UNDER 30 KNOTS. YESTERDAY`S HIGHS OF LOW 90S TO MID 90S IN THE SOUTHWEST SECTIONS ARE A REASONABLE TELL FOR HIGHS TODAY. THE LATEST SHORT TERM CONSENSUS SUPPORTS MID 90S TO NEAR 100 DEGREES IN THE SW GIVEN THE COMBINATION OF SLIGHTLY DRIER AIR AND BETTER DOWNSLOPE. WITH THE FRONTAL BOUNDARY AND POTENTIAL MOIST BOUNDARY LAYER OUTFLOW ACROSS THE AREA TONIGHT, A LARGE GRADIENT OF AROUND 20 DEGREES COULD EXIST FOR OVERNIGHT LOWS FROM MID 50`S OUT WEST TO MID 70S IN THE PRATT COLDWATER AND MEDICINE LODGE AREA SETTING AN EARLY MILD LOW JUST AFTER MIDNIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 414 AM CDT SUN AUG 31 2014 THE FRONT FOLLOWING TONIGHTS STORM SYSTEM WILL REACH THE TEXAS PANHANDLE AND ADJACENT WESTERN OKLAHOMA BY LATE MONDAY/MONDAY NIGHT. THE DAYTIME HOURS MONDAY WILL BE FAIRLY TRANQUIL AS SUBSIDENCE WILL PREVAIL IN THE WAKE OF THE DEPARTING SYSTEM. MODEST TEMPERATURES IN THE 80S ARE EXPECTED. THE FRONT WILL STALL OUT MONDAY NIGHT AND WE WILL FIND OURSELVES IN THE RIGHT ENTRANCE REGION OF AN UPPER TROPOSPHERIC JET. THIS WILL ENHANCE FRONTOGENESIS IN THE 900-800MB LAYER, SUPPORTING NOCTURNAL THUNDERSTORMS ONCE THE LOW LEVEL JET DEVELOPS. THE MOST FAVORABLE LOCATION FOR MONDAY NIGHT/EARLY TUESDAY STORMS WILL BE ACROSS SOUTH CENTRAL KANSAS, WHICH IS WHERE WE WILL HAVE THE HIGHEST CHANCE POPS (AROUND 40 PERCENT). THIS FRONTAL ZONE WILL NOT MOVE TUESDAY, AND WE WILL NEED TO CARRY SOME CHANCE POPS THROUGH THE DAY ACROSS SOUTH CENTRAL KANSAS. DAYTIME TEMPERATURES WILL BE AT OR JUST SLIGHTLY ABOVE AVERAGE FOR THE FIRST PART OF SEPTEMBER (MID TO UPPER 80S AS A RULE). THE FRONT WILL EVENTUALLY DISSOLVE BY LATE TUESDAY NIGHT AND ESPECIALLY BY WEDNESDAY, AS THE LOW LEVEL FLOW FIELD BEGINS TO RESPOND TO LOWER PRESSURE MUCH FARTHER NORTH WHERE THE POLAR JET WILL BE LOCATED. THE NEXT STORM SYSTEM MID-WEEK WILL BE MUCH FARTHER NORTH WITH WEAK ZONAL FLOW ACROSS COLORADO AND KANSAS FOR THE MOST PART. THIS WILL LEAD TO WARMER TEMPERATURES AND DRIER WEATHER. WEDNESDAY AND THURSDAY CONTINUE TO LOOK LIKE THE HOTTEST DAYS NEXT WEEK WITH AFTERNOON HIGHS IN THE 95-100F RANGE FOR MUCH OF WESTERN AND SOUTHERN KANSAS. THE NORTHERN POLAR JET STORM SYSTEM THAT WAS MENTIONED WILL MOVE EAST ACROSS THE NORTHERN GREAT PLAINS/ADJACENT CANADIAN PRAIRIES LATE IN THE WEEK, USHERING IN SOME MUCH COOLER TEMPERATURES ACROSS THE NORTHERN PLAINS. THIS AIRMASS WILL LIKELY REACH KANSAS BY END OF WEEK AND INTO THE WEEKEND. THERE APPEARS TO BE A FAIRLY STRONG SIGNAL OF COOLER/WETTER WEATHER SEPTEMBER 6-8 TIME FRAME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1216 PM CDT SUN AUG 31 2014 A DRYLINE WILL SET UP BETWEEN THE GCK AND DDC TERMINAL THIS AFTERNOON WITH SOUTH SOUTHWEST WINDS FELT ACROSS THE GCK TERMINAL AND SOUTH TO SOUTH SOUTHEAST WINDS FELT AT THE HYS AND DDC TERMINALS. BREEZY CONDITIONS WILL ALSO OCCUR ACROSS THE TAF SITES THIS AFTERNOON WITH SUSTAINED WINDS ABOVE 20 KNOTS AND GUSTS ABOVE 30 KNOTS. WINDS THEN DIE DOWN THIS EVENING BEFORE BECOMING LIGHT AND VARIABLE OVERNIGHT. A FEW THUNDERSTORMS MAY DEVELOP ACROSS THE HYS AND DDC TERMINALS EARLY THIS EVENING BRIEFLY REDUCING VISIBILITIES AND CEILINGS. I HAVE PLACED A TEMPO GROUP IN THE TAFS TO REFLECT THIS. && .PRELIMINARY POINT TEMPS/POPS... DDC 99 65 87 65 / 50 30 10 30 GCK 100 62 87 63 / 20 30 10 20 EHA 100 62 91 63 / 10 10 10 10 LBL 103 65 91 64 / 10 20 10 20 HYS 97 64 84 63 / 50 60 20 20 P28 99 71 90 70 / 10 20 20 50 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RUSSELL LONG TERM...UMSCHEID AVIATION...HOVORKA_42
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
715 AM CDT SUN AUG 31 2014 ...UPDATED LONG TERM SECTION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 333 AM CDT SUN AUG 31 2014 THE HRRR WAS INDICATING A BROKEN LINE OF RELATIVELY LIGHT REFLECTIVITY MOVING EASTWARD FROM THE AFOREMENTIONED DEVELOPMENT ZONE INTO CENTRAL KS BY AROUND 10-12 UTC. THIS SOLUTION WAS FOLLOWED WITH BASICALLY LOW POPS BELOW 20 PERCENT. THE MORE SIGNIFICANT ISSUE FOR THE DAY WILL BE A LATE DAY OR EVENING SEVERE WEATHER THREAT. THE NMM AND ARW MODEL RUNS DEVELOPED A QLCS TYPE BOWING SEGMENT ACROSS NORTHERN KS, ALONG AND AHEAD OF A COLD FRONT/DRYLINE INTERSECTION OVER NORTHERN KS. FARTHER SOUTH, OVER OUR AREA, ANY CONVECTION IN THESE SOLUTIONS COULD BE GENERALLY MORE DISCREET AND MORE HIGH BASED (HAIL AND WIND THREATS POSSIBLE) WITH SUFFICIENT SHEAR FOR SUPERCELLS. HOWEVER, IT IS POSSIBLE OUTFLOWS/COLD POOLS COULD FORCE MORE WIDESPREAD DEVELOPMENT FARTHER BRINGING MORE OF OUR AREA INTO A SEVERE WEATHER THREAT. SURFACE WINDS WILL BE MORE BREEZY AHEAD OF THE DRYLINE THIS AFTERNOON. MODELS SUGGEST 15 TO 20 KNOTS SUSTAINED WINDS WILL BE COMMON WITH GUSTS IN TO JUST UNDER 30 KNOTS. YESTERDAY`S HIGHS OF LOW 90S TO MID 90S IN THE SOUTHWEST SECTIONS ARE A REASONABLE TELL FOR HIGHS TODAY. THE LATEST SHORT TERM CONSENSUS SUPPORTS MID 90S TO NEAR 100 DEGREES IN THE SW GIVEN THE COMBINATION OF SLIGHTLY DRIER AIR AND BETTER DOWNSLOPE. WITH THE FRONTAL BOUNDARY AND POTENTIAL MOIST BOUNDARY LAYER OUTFLOW ACROSS THE AREA TONIGHT, A LARGE GRADIENT OF AROUND 20 DEGREES COULD EXIST FOR OVERNIGHT LOWS FROM MID 50`S OUT WEST TO MID 70S IN THE PRATT COLDWATER AND MEDICINE LODGE AREA SETTING AN EARLY MILD LOW JUST AFTER MIDNIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 414 AM CDT SUN AUG 31 2014 THE FRONT FOLLOWING TONIGHTS STORM SYSTEM WILL REACH THE TEXAS PANHANDLE AND ADJACENT WESTERN OKLAHOMA BY LATE MONDAY/MONDAY NIGHT. THE DAYTIME HOURS MONDAY WILL BE FAIRLY TRANQUIL AS SUBSIDENCE WILL PREVAIL IN THE WAKE OF THE DEPARTING SYSTEM. MODEST TEMPERATURES IN THE 80S ARE EXPECTED. THE FRONT WILL STALL OUT MONDAY NIGHT AND WE WILL FIND OURSELVES IN THE RIGHT ENTRANCE REGION OF AN UPPER TROPOSPHERIC JET. THIS WILL ENHANCE FRONTOGENESIS IN THE 900-800MB LAYER, SUPPORTING NOCTURNAL THUNDERSTORMS ONCE THE LOW LEVEL JET DEVELOPS. THE MOST FAVORABLE LOCATION FOR MONDAY NIGHT/EARLY TUESDAY STORMS WILL BE ACROSS SOUTH CENTRAL KANSAS, WHICH IS WHERE WE WILL HAVE THE HIGHEST CHANCE POPS (AROUND 40 PERCENT). THIS FRONTAL ZONE WILL NOT MOVE TUESDAY, AND WE WILL NEED TO CARRY SOME CHANCE POPS THROUGH THE DAY ACROSS SOUTH CENTRAL KANSAS. DAYTIME TEMPERATURES WILL BE AT OR JUST SLIGHTLY ABOVE AVERAGE FOR THE FIRST PART OF SEPTEMBER (MID TO UPPER 80S AS A RULE). THE FRONT WILL EVENTUALLY DISSOLVE BY LATE TUESDAY NIGHT AND ESPECIALLY BY WEDNESDAY, AS THE LOW LEVEL FLOW FIELD BEGINS TO RESPOND TO LOWER PRESSURE MUCH FARTHER NORTH WHERE THE POLAR JET WILL BE LOCATED. THE NEXT STORM SYSTEM MID-WEEK WILL BE MUCH FARTHER NORTH WITH WEAK ZONAL FLOW ACROSS COLORADO AND KANSAS FOR THE MOST PART. THIS WILL LEAD TO WARMER TEMPERATURES AND DRIER WEATHER. WEDNESDAY AND THURSDAY CONTINUE TO LOOK LIKE THE HOTTEST DAYS NEXT WEEK WITH AFTERNOON HIGHS IN THE 95-100F RANGE FOR MUCH OF WESTERN AND SOUTHERN KANSAS. THE NORTHERN POLAR JET STORM SYSTEM THAT WAS MENTIONED WILL MOVE EAST ACROSS THE NORTHERN GREAT PLAINS/ADJACENT CANADIAN PRAIRIES LATE IN THE WEEK, USHERING IN SOME MUCH COOLER TEMPERATURES ACROSS THE NORTHERN PLAINS. THIS AIRMASS WILL LIKELY REACH KANSAS BY END OF WEEK AND INTO THE WEEKEND. THERE APPEARS TO BE A FAIRLY STRONG SIGNAL OF COOLER/WETTER WEATHER SEPTEMBER 6-8 TIME FRAME. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 713 AM CDT SUN AUG 31 2014 STRONG TO SEVERE THUNDERSTORMS WILL DEVELOP ACROSS WESTERN KANSAS LATE THIS AFTERNOON INTO THIS EVENING. WE WILL GO AHEAD AND INCLUDE A PROB30 FOR TSRA FOR GCK, DDC, AND HYS FOR A 3 OR 4 HOUR PERIOD. BY LATE EVENING, THE THUNDERSTORM THREAT WILL MOVE EAST, LEAVING IN ITS WAKE LIGHTER WINDS FROM THE NORTH. && .PRELIMINARY POINT TEMPS/POPS... DDC 98 65 87 65 / 30 50 10 30 GCK 99 62 87 63 / 40 50 10 20 EHA 100 62 91 63 / 10 10 10 10 LBL 102 65 91 64 / 20 20 10 20 HYS 96 64 84 63 / 50 80 20 20 P28 99 71 90 70 / 10 20 20 50 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RUSSELL LONG TERM...UMSCHEID AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
417 AM CDT SUN AUG 31 2014 ...UPDATED LONG TERM SECTION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 333 AM CDT SUN AUG 31 2014 THE HRRR WAS INDICATING A BROKEN LINE OF RELATIVELY LIGHT REFLECTIVITY MOVING EASTWARD FROM THE AFOREMENTIONED DEVELOPMENT ZONE INTO CENTRAL KS BY AROUND 10-12 UTC. THIS SOLUTION WAS FOLLOWED WITH BASICALLY LOW POPS BELOW 20 PERCENT. THE MORE SIGNIFICANT ISSUE FOR THE DAY WILL BE A LATE DAY OR EVENING SEVERE WEATHER THREAT. THE NMM AND ARW MODEL RUNS DEVELOPED A QLCS TYPE BOWING SEGMENT ACROSS NORTHERN KS, ALONG AND AHEAD OF A COLD FRONT/DRYLINE INTERSECTION OVER NORTHERN KS. FARTHER SOUTH, OVER OUR AREA, ANY CONVECTION IN THESE SOLUTIONS COULD BE GENERALLY MORE DISCREET AND MORE HIGH BASED (HAIL AND WIND THREATS POSSIBLE) WITH SUFFICIENT SHEAR FOR SUPERCELLS. HOWEVER, IT IS POSSIBLE OUTFLOWS/COLD POOLS COULD FORCE MORE WIDESPREAD DEVELOPMENT FARTHER BRINGING MORE OF OUR AREA INTO A SEVERE WEATHER THREAT. SURFACE WINDS WILL BE MORE BREEZY AHEAD OF THE DRYLINE THIS AFTERNOON. MODELS SUGGEST 15 TO 20 KNOTS SUSTAINED WINDS WILL BE COMMON WITH GUSTS IN TO JUST UNDER 30 KNOTS. YESTERDAY`S HIGHS OF LOW 90S TO MID 90S IN THE SOUTHWEST SECTIONS ARE A REASONABLE TELL FOR HIGHS TODAY. THE LATEST SHORT TERM CONSENSUS SUPPORTS MID 90S TO NEAR 100 DEGREES IN THE SW GIVEN THE COMBINATION OF SLIGHTLY DRIER AIR AND BETTER DOWNSLOPE. WITH THE FRONTAL BOUNDARY AND POTENTIAL MOIST BOUNDARY LAYER OUTFLOW ACROSS THE AREA TONIGHT, A LARGE GRADIENT OF AROUND 20 DEGREES COULD EXIST FOR OVERNIGHT LOWS FROM MID 50`S OUT WEST TO MID 70S IN THE PRATT COLDWATER AND MEDICINE LODGE AREA SETTING AN EARLY MILD LOW JUST AFTER MIDNIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 414 AM CDT SUN AUG 31 2014 THE FRONT FOLLOWING TONIGHTS STORM SYSTEM WILL REACH THE TEXAS PANHANDLE AND ADJACENT WESTERN OKLAHOMA BY LATE MONDAY/MONDAY NIGHT. THE DAYTIME HOURS MONDAY WILL BE FAIRLY TRANQUIL AS SUBSIDENCE WILL PREVAIL IN THE WAKE OF THE DEPARTING SYSTEM. MODEST TEMPERATURES IN THE 80S ARE EXPECTED. THE FRONT WILL STALL OUT MONDAY NIGHT AND WE WILL FIND OURSELVES IN THE RIGHT ENTRANCE REGION OF AN UPPER TROPOSPHERIC JET. THIS WILL ENHANCE FRONTOGENESIS IN THE 900-800MB LAYER, SUPPORTING NOCTURNAL THUNDERSTORMS ONCE THE LOW LEVEL JET DEVELOPS. THE MOST FAVORABLE LOCATION FOR MONDAY NIGHT/EARLY TUESDAY STORMS WILL BE ACROSS SOUTH CENTRAL KANSAS, WHICH IS WHERE WE WILL HAVE THE HIGHEST CHANCE POPS (AROUND 40 PERCENT). THIS FRONTAL ZONE WILL NOT MOVE TUESDAY, AND WE WILL NEED TO CARRY SOME CHANCE POPS THROUGH THE DAY ACROSS SOUTH CENTRAL KANSAS. DAYTIME TEMPERATURES WILL BE AT OR JUST SLIGHTLY ABOVE AVERAGE FOR THE FIRST PART OF SEPTEMBER (MID TO UPPER 80S AS A RULE). THE FRONT WILL EVENTUALLY DISSOLVE BY LATE TUESDAY NIGHT AND ESPECIALLY BY WEDNESDAY, AS THE LOW LEVEL FLOW FIELD BEGINS TO RESPOND TO LOWER PRESSURE MUCH FARTHER NORTH WHERE THE POLAR JET WILL BE LOCATED. THE NEXT STORM SYSTEM MID-WEEK WILL BE MUCH FARTHER NORTH WITH WEAK ZONAL FLOW ACROSS COLORADO AND KANSAS FOR THE MOST PART. THIS WILL LEAD TO WARMER TEMPERATURES AND DRIER WEATHER. WEDNESDAY AND THURSDAY CONTINUE TO LOOK LIKE THE HOTTEST DAYS NEXT WEEK WITH AFTERNOON HIGHS IN THE 95-100F RANGE FOR MUCH OF WESTERN AND SOUTHERN KANSAS. THE NORTHERN POLAR JET STORM SYSTEM THAT WAS MENTIONED WILL MOVE EAST ACROSS THE NORTHERN GREAT PLAINS/ADJACENT CANADIAN PRAIRIES LATE IN THE WEEK, USHERING IN SOME MUCH COOLER TEMPERATURES ACROSS THE NORTHERN PLAINS. THIS AIRMASS WILL LIKELY REACH KANSAS BY END OF WEEK AND INTO THE WEEKEND. THERE APPEARS TO BE A FAIRLY STRONG SIGNAL OF COOLER/WETTER WEATHER SEPTEMBER 6-8 TIME FRAME. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1122 PM CDT SAT AUG 30 2014 A VERY SMALL CLUSTER OF GRADUALLY WEAKENING THUNDERSTORMS NEAR GARDEN CITY EARLIER WERE MOVING TO THE SOUTH OF THE DDC TERMINAL AND EXPECTED TO NOT HAVE A DIRECT IMPACT. HOWEVER, ELEVATED WARM ADVECTION SHOWERS AND PROBABLY ISOLATED THUNDERSTORMS MAY MOVE THROUGH THE AREA BETWEEN 6 AND 10 Z. ANY THUNDERSTORMS SHOULD BE TOO FEW AND FAR BETWEEN TO CONSIDER FOR EVEN A TEMPO GROUP AT THIS TIME. SLIGHTLY MORE BREEZY CONDITIONS ARE EXPECTED SUNDAY AFTERNOON AHEAD OF A SURFACE DRYLINE. THESE MORE BREEZY CONDITIONS ARE EXPECTED FROM DDC TO HYS. LATE AFTERNOON TO EVENING DEEP MOIST CONVECTION MAY DEVELOP ANYWHERE ALONG THE DRYLINE OR AND INCOMING COLD FRONT NORTH OF GARDEN CITY IN THE EVENING, POSSIBLY POSING A LOW PROBABILITY SEVERE THREAT WITH THE BEST CHANCES NEAR THE HYS TERMINAL. && .PRELIMINARY POINT TEMPS/POPS... DDC 98 65 87 65 / 30 50 10 30 GCK 99 62 87 63 / 40 50 10 20 EHA 100 62 91 63 / 10 10 10 10 LBL 102 65 91 64 / 20 20 10 20 HYS 96 64 84 63 / 50 80 20 20 P28 99 71 90 70 / 10 20 20 50 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RUSSELL LONG TERM...UMSCHEID AVIATION...33
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
337 AM CDT SUN AUG 31 2014 ...UPDATED SHORT TERM... .SYNOPSIS... ISSUED AT 333 AM CDT SUN AUG 31 2014 WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WERE DEVELOPING FROM THE NORTHEAST TEXAS PANHANDLE THROUGH LIBERAL AND NORTHWARD TO NEAR THE I-70 CORRIDOR WEST OF CEDAR BLUFF. THESE WERE ASSOCIATED WITH A WARM AIR AND MOISTURE ADVECTION PATTERN ACROSS THE WESTERN 1/3 OF KS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 333 AM CDT SUN AUG 31 2014 THE HRRR WAS INDICATING A BROKEN LINE OF RELATIVELY LIGHT REFLECTIVITY MOVING EASTWARD FROM THE AFOREMENTIONED DEVELOPMENT ZONE INTO CENTRAL KS BY AROUND 10-12 UTC. THIS SOLUTION WAS FOLLOWED WITH BASICALLY LOW POPS BELOW 20 PERCENT. THE MORE SIGNIFICANT ISSUE FOR THE DAY WILL BE A LATE DAY OR EVENING SEVERE WEATHER THREAT. THE NMM AND ARW MODEL RUNS DEVELOPED A QLCS TYPE BOWING SEGMENT ACROSS NORTHERN KS, ALONG AND AHEAD OF A COLD FRONT/DRYLINE INTERSECTION OVER NORTHERN KS. FARTHER SOUTH, OVER OUR AREA, ANY CONVECTION IN THESE SOLUTIONS COULD BE GENERALLY MORE DISCREET AND MORE HIGH BASED (HAIL AND WIND THREATS POSSIBLE) WITH SUFFICIENT SHEAR FOR SUPERCELLS. HOWEVER, IT IS POSSIBLE OUTFLOWS/COLD POOLS COULD FORCE MORE WIDESPREAD DEVELOPMETN FARTHER BRINGING MORE OF OUR AREA INTO A SEVERE WEATHER THREAT. SURFACE WINDS WILL BE MORE BREEZY AHEAD OF THE DRYLINE THIS AFTERNOON. MODELS SUGGEST 15 TO 20 KNOTS SUSTAINED WINDS WILL BE COMMON WITH GUSTS IN TO JUST UNDER 30 KNOTS. YESTERDAY`S HIGHS OF LOW 90S TO MID 90S IN THE SOUTHWEST SECTIONS ARE A REASONABLE TELL FOR HIGHS TODAY. THE LATEST SHORT TERM CONSENSUS SUPPORTS MID 90S TO NEAR 100 DEGREES IN THE SW GIVEN THE COMBINATION OF SLIGHTLY DRIER AIR AND BETTER DOWNSLOPE. WITH THE FRONTAL BOUNDARY AND POTENTIAL MOIST BOUNDARY LAYER OUTFLOW ACROSS THE AREA TONIGHT, A LARGE GRADIENT OF AROUND 20 DEGREES COULD EXIST FOR OVERNIGHT LOWS FROM MID 50`S OUT WEST TO MID 70S IN THE PRATT COLDWATER AND MEDICINE LODGE AREA SETTING AN EARLY MILD LOW JUST AFTER MIDNIGHT. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 243 PM CDT SAT AUG 30 2014 A SURFACE BOUNDARY WILL EXTEND FROM NORTHEAST COLORADO INTO NORTH CENTRAL KANSAS AT 00Z SUNDAY AS AN UPPER LEVEL TROUGH BEGINS TO MOVE OUT INTO THE CENTRAL HIGH PLAINS. GIVEN THE EXPECTED LOW LEVEL MOISTURE POOLING NORTH OF THIS FRONT ALONG WITH LOCATION OF THE LEFT EXIT REGION OF AN UPPER LEVEL JET AND LATE DAY INSTABILITY NEAR THE NORTHERN EDGE OF A +13C TO +16C 700MB TEMPERATURE GRADIENT WILL CONTINUE TO FAVOR CONVECTION INCREASING IN AREAL COVERAGE DURING THE EARLY EVENING AS IT SPREADS EAST ACROSS NORTHWEST AND NORTH CENTRAL KANSAS. SEVERE THUNDERSTORMS WILL BE POSSIBLE SUNDAY EVENING IN THIS AREA BASED ON THE 0-6KM SHEAR VALUES RANGING FROM 30 TO 40 KNOTS WITH SURFACE BASED CAPES GREATER THAN 2000 J/KG. WIDESPREAD HEAVY RAINFALL MAY ALSO BE AN ISSUE ACROSS NORTH CENTRAL KANSAS OVERNIGHT GIVEN THE PRECIPTABLE WATER VALUES OF 1.5 TO NEAR 2 INCHES AND A LOW LEVEL JET DEVELOPS AHEAD OF THE EASTWARD MOVING UPPER LEVEL TROUGH. AT THIS TIME MODELS DIFFERING SOME ON WHERE THE MID LEVEL BAROCLINIC ZONE WILL BE SUNDAY NIGHT AND DUE TO LOW CONFIDENCE ON WHERE IT WILL BE SUNDAY NIGHT HAVE DECIDED TO STAY CLOSE TO THE PREVIOUS FORECAST ON SOUTHERN EXTENT OF THE OVERNIGHT CONVECTION. THIS WILL KEEP THE BULK OF PRECIPITATION SUNDAY NIGHT ALONG AND NORTH OF HIGHWAY 96. FURTHER SOUTH A DRYLINE WILL BE LOCATED ACROSS WESTERN KANSAS, HOWEVER ABOVE THIS DRYLINE 700MB TEMPERATURES WERE FORECAST TO WARM TO +14 TO NEAR +16C. THESE WARM MID LEVEL TEMPERATURES WILL LIMIT HOW WIDESPREAD CONVECTION WILL BE FURTHER SOUTH, HOWEVER AT THIS TIME AM NOT COMPLETELY ABLE TO RULE ON A FEW SCATTERED/WIDELY SCATTERED THUNDERSTORMS EARLY SUNDAY NIGHT. WITH SIMILAR INSTABILITY AND SHEAR VALUES EXPECTED IN THE EVENING ANY STORM WHICH DOES DEVELOP ALONG THE DRYLINE WILL ALSO HAVE THE POTENTIAL FOR BECOMING SEVERE. AS THE UPPER LEVEL TROUGH MOVES INTO CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS A COLD FRONT WILL MOVE SOUTH ACROSS WESTERN KANSAS LATE SUNDAY NIGHT. RAIN WILL END FROM WEST TO EAST AND LOWER DEWPOINTS/COOLER AIR WILL BEGIN TO BRIEFLY SETTLE INTO SOUTHWEST KANSAS BY EARLY MONDAY. GUSTY NORTH WINDS JUST BEHIND THE FRONT WILL DECREASE DURING THE DAY AS AN AREA OF HIGH PRESSURE EXITS MOVES ACROSS NORTHWEST KANSAS. 850MB TEMPERATURES AT 00Z TUESDAY SUPPORTING HIGHS MAINLY IN THE 80S. HIGHS IN THE LOWER 90S STILL APPEAR POSSIBLE NEAR THE OKLAHOMA BORDER. MOISTURE, WARM AIR ADVECTION, AND ISENTROPIC LIFT IMPROVES MONDAY NIGHT INTO TUESDAY ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS AS ANOTHER UPPER LEVEL DISTURBANCE CROSSES THE CENTRAL PLAINS. THIS WILL RESULT IN INCREASING CLOUDS AND POSSIBLY A FEW SHOWERS/THUNDERSTORMS NORTH OF OUR SURFACE BOUNDARY. INCREASING CLOUDS MONDAY NIGHT WILL AID IN KEEPING TEMPERATURES UP WHILE AT THIS TIME IT APPEARS THE BETTER CHANCES FOR PRECIPITATION WILL BE ACROSS SOUTH CENTRAL KANSAS. A WARMING TREND WILL THEN DEVELOP MID WEEK AS A WARM FRONT LIFTS NORTH ACROSS KANSAS AND A WESTERLY DOWNSLOPE FLOW IMPROVES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1122 PM CDT SAT AUG 30 2014 A VERY SMALL CLUSTER OF GRADUALLY WEAKENING THUNDERSTORMS NEAR GARDEN CITY EARLIER WERE MOVING TO THE SOUTH OF THE DDC TERMINAL AND EXPECTED TO NOT HAVE A DIRECT IMPACT. HOWEVER, ELEVATED WARM ADVECTION SHOWERS AND PROBABLY ISOLATED THUNDERSTORMS MAY MOVE THROUGH THE AREA BETWEEN 6 AND 10 Z. ANY THUNDERSTORMS SHOULD BE TOO FEW AND FAR BETWEEN TO CONSIDER FOR EVEN A TEMPO GROUP AT THIS TIME. SLIGHTLY MORE BREEZY CONDITIONS ARE EXPECTED SUNDAY AFTERNOON AHEAD OF A SURFACE DRYLINE. THESE MORE BREEZY CONDITIONS ARE EXPECTED FROM DDC TO HYS. LATE AFTERNOON TO EVENING DEEP MOIST CONVECTION MAY DEVELOP ANYWHERE ALONG THE DRYLINE OR AND INCOMING COLD FRONT NORTH OF GARDEN CITY IN THE EVENING, POSSIBLY POSING A LOW PROBABILITY SEVERE THREAT WITH THE BEST CHANCES NEAR THE HYS TERMINAL. && .PRELIMINARY POINT TEMPS/POPS... DDC 98 65 87 65 / 30 50 10 30 GCK 99 62 87 63 / 40 50 10 20 EHA 100 62 91 63 / 10 10 10 10 LBL 102 65 91 64 / 20 20 10 20 HYS 96 64 84 63 / 50 80 20 20 P28 99 71 90 70 / 10 20 20 30 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RUSSELL SHORT TERM...RUSSELL LONG TERM...BURGERT AVIATION...33
AREA FORECAST DISCUSSION
NWS GOODLAND KS
237 AM MDT SUN AUG 31 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 237 AM MDT SUN AUG 31 2014 SHORTWAVE THAT BROUGHT SCATTERED RW/TRW TO PORTIONS OF THE FORECAST AREA OVERNIGHT WILL CONTINUE TO SHIFT EAST OF THE AREA THIS MORNING...WITH SOME LINGERING MID CLOUD COVER STILL TO CLR THE REGION BY MID MORNING. EXPECTING CONDITIONS TO IMPROVE BY MIDDAY AS WEAK RIDGING PROVIDE SEVERAL HOURS OF DRY CONDITIONS BEFORE NEXT ROUND OF PRECIPITATION MOVES TO AFFECT THE AREA LATER THIS AFTERNOON INTO THE EVENING HOURS. IT IS THIS TIMEFRAME THAT WILL POSE A SEVERE WX THREAT TO MUCH OF THE TRI STATE REGION. HIGH PRESSURE IS GOING TO GIVE WAY TO A STRONG SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT LATER THIS AFTERNOON AND SWING THRU THE AREA THRU 12Z MONDAY. LATEST MODEL TRACK OF THE UPPER TROUGH THRU THE PERIOD...PUTS BEST DYNAMICS FOR SEVERE CONDITIONS OVER EASTERN ZONES...ESPECIALLY AREAS NORTH AND EAST OF GOODLAND. BULK SHEAR 0-6KM WILL RANGING FROM 37 KTS SOUTH TO NEAR 60 KTS NORTH...COMBINED WITH LL JET 30-40KTS...LI/S -4 TO -8 AND HIGH DEWPTS WILL ALLOW FOR POTENTIAL SEVERE THUNDER TO DEVELOP...EVEN THE CHANCE FOR A TORNADO. THIS IS REINFORCED BY SPC PUTTING MUCH OF THE FORECAST AREA IN SLIGHT RISK IN THE AFOREMENTIONED TIMEFRAME WHERE DAMAGING WINDS AND LARGE HAIL/TORNADO ARE POSSIBLE. HAVE THUS CONTINUED ENHANCED WORDING IN FORECAST FOR THESE ELEMENTS. MODELS DO KEEP SYSTEM FAIRLY PROGRESSIVE THRU THE AREA OVERNIGHT WITH PRECIP TAPERING FROM WEST TO EAST BY 06Z-12Z. HIGHS TODAY WILL RANGE FROM THE MID 80S THRU THE MID 90S...WHILE THE COLD FRONT WILL HELP TO DROP THE AREA INTO THE MID 50S TO LOW 60S FOR LOWS TONIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 237 AM MDT SUN AUG 31 2014 GOING INTO MONDAY...FRONTAL BOUNDARY AND ASSOCIATED PRECIPITATION HAS SHIFTED WELL EAST OF THE FORECAST AREA...ALLOWING FOR HIGH PRESSURE TO BUILD OVER THE REGION. BY MONDAY EVENING RIGHT INTO TUESDAY MORNING...MODELS SHOW FRONTAL BOUNDARY STALLING OVER THE GREAT LKS REGION BACK DOWN ACROSS SOUTHERN PORTIONS OF KANSAS BUT CLRING OUT BY MIDDAY TUESDAY FOR A QUIET STRETCH OF WEATHER INTO TUESDAY NIGHT DUE TO SFC HIGH PRESSURE. WITH RIDGE BLOCKING MOST OF THE CWA FROM THE STALLED FRONT...WILL ONLY PUT IN 15-25 POPS ALONG EXTREME SOUTHERN ZONES FOR TRW/RW. TEMPERATURES DURING THIS TIME FRAME WILL RANGE IN THE MID 80S FOR HIGHS...DOWN TO THE MID 50S TO LOW 60S FOR OVERNGT LOWS. THE EXTENDED PERIOD WILL START OUT DRY WITH TEMPERATURES WARMER THAN PREVIOUS DAYS. BROAD UPPER RIDGING WILL CONTINUE ACROSS A LARGE PORTION OF THE SOUTHERN AND CENTRAL UNITED STATES THROUGH MID WEEK WITH A PROGRESSIVE ZONAL FLOW PATTERN IN THE HIGHER LATITUDES. LATE IN THE PERIOD...IN RESPONSE TO A MID/UPPER SHORTWAVE THAT WILL CROSS THE NORTHERN PLAINS...THE LEE SURFACE TROUGH WILL EVOLVE INTO A BROAD ELONGATING LOW WITH INCREASING BAROCLINICITY IN THE TRAILING PORTION THAT MOVES THROUGH OUR AREA. ALONG AND BEHIND THIS FRONT...SHOWERS AND THUNDERSTORM CHANCES WILL BEGIN THURSDAY NIGHT AND LAST THROUGH SATURDAY. TEMPERATURES WILL GRADUALLY FALL LATE IN THE WEEK LIKELY REACHING BELOW NORMAL LEVELS BY THE WEEKEND. ALTHOUGH SOME DISAGREEMENT EXISTS...CONSENSUS OF DETERMINISTIC GUIDANCE SEEMS TO FALL IN ABOUT THE MIDDLE OF ENSEMBLE MEMBERS SO CONFIDENCE IS ABOUT AVERAGE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1137 PM MDT SAT AUG 30 2014 PERSISTENT VFR CONDITIONS EXPECTED THROUGH THIS TAF CYCLE. SHOWERS/ISOLATED STORMS ARE MOVING INTO KGLD SO HAVE PLACED VCTS BACK INTO TAF. KGLD VAD WIND PROFILE DEPICTS A LOW LEVEL JET OF 45 KTS OVER KGLD AT PRESENT TIME WITH RAP MODEL ANALYSIS INDICATING STRONG WINDS OVER KMCK. MAINTAINED LLWS IN TAF WITH OUTFLOW BOUNDARIES AND SOMEWHAT ERRATIC SURFACE WINDS MOVING THROUGH. FOR THIS AFTERNOON...PLACED VCTS INTO KMCK TAF AS CONVECTION IS EXPECTED TO DEVELOP AHEAD OF A VIGOROUS UPPER LEVEL DISTURBANCE. STORMS COULD PRODUCE STRONG WIND GUSTS IN EXCESS OF 50 KTS AND LARGE HAIL. NOT CONFIDENT ENOUGH TO PLACE TS INTO KGLD TAF AS MOST MODEL GUIDANCE REMAINS INSISTENT CONVECTION STAYS NORTHEAST. COLD FRONT SLIDES THROUGH DURING THE EVENING...BRINGING LIGHT NORTH WINDS AND CALM WEATHER BEHIND THE UPPER LEVEL DISTURBANCE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JN LONG TERM...JN/BRB AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
121 AM MDT SUN AUG 31 2014 .UPDATE... ISSUED AT 119 AM MDT SUN AUG 31 2014 UPDATE ISSUED TO INCREASE POPS FOR TRW/RW THAT HAS DEVELOPED...AND WILL CARRY THRU UNTIL NEXT ESTF AND/OR 12Z THIS MORNING. BULK OF ANY REMAINING PRECIP WILL BE FOCUSED OVER AREAS EAST OF GOODLAND. REST OF FORECAST ON TRACK AT THIS TIME. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 1239 PM MDT SAT AUG 30 2014 18Z WATER VAPOR IMAGERY INDICATED SHORT WAVE RIDGING IN PLACE ACROSS THE NORTHERN PLAINS WITH NOTICEABLE SHORT WAVE TROUGH MOVING INTO UTAH. AT THE SURFACE...LEE TROUGH DEVELOPING ACROSS WESTERN CWA WITH SOUTHWESTERLY WINDS IN THE 10 TO 20 KT RANGE COMMON. PRIMARY FORECAST CONCERN WILL CENTER AROUND PRECIP CHANCES THIS EVENING AND AGAIN ON SUNDAY. TONIGHT...SHORT WAVE TROUGH CURRENTLY OVER UTAH WILL CONTINUE TO DRIFT TO THE EAST TONIGHT...WITH LARGE SCALE FORCING INCREASING BETWEEN 03 AND 09Z IN RESPONSE. INSTABILITY...BOTH SURFACE AND ELEVATED APPEAR TO BE VERY LIMITED SO DO NOT ANTICIPATE MANY STRONG/SEVERE STORMS. WHILE A FEW LATE AFTERNOON STORMS ARE POSSIBLE...DO EXPECT BEST CHANCES TO OCCUR WHEN LARGE SCALE FORCING/INCREASING LLJ ARE MAXIMIZED. TOMORROW...POTENTIAL FOR SEVERE THUNDERSTORMS...ESPECIALLY IN THE EASTERN CWA LOOKS ON TRACK AS FRONTAL BOUNDARY SLOWLY SAGS SOUTH ACROSS THE AREA. THINK BEST CHANCE FOR CONVECTIVE INITIATION WILL BE ALONG DEVELOPING DRY LINE TO THE THE SOUTH OF THE FRONTAL ZONE. WHILE STRONG INSTABILITY AND SHEAR EXIST TO THE NORTH OF FRONT...STRONG CAP MAKES ANY EARLY INITIATION UNLIKELY. A FEW STORMS COULD DEVELOP OVER THE HIGHER TERRAIN AND DRIFT INTO THE CWA...BUT THIS SCENARIO MOST LIKELY AFTER SUNSET. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 230 PM MDT SAT AUG 30 2014 MAIN FOCUS IS STILL ON THE POTENTIAL FOR SEVERE THUNDERSTORMS INTO SUNDAY EVENING AS SURFACE COLD FRONT MOVES ACROSS THE FORECAST AREA AND THE AXIS OF THE UPPER TROUGH SWEEPS ACROSS THE CENTRAL HIGH PLAINS REGION. WITH HIGHS IN THE 90S AND DEWPOINTS IN THE UPPER 50S TO LOWER 60S...INSTABILITY AND SHEAR SHOULD BE FAVORABLE FOR SUPERCELLS ACROSS THE EASTERN PORTION OF THE FORECAST AREA WITH LARGE HAIL AND ISOLATED TORNADOS TRANSITIONING INTO MAINLY A WIND THREAT BY LATE EVENING. COOLER...NEAR AVERAGE...TEMPERATURES FOR THIS TIME OF YEAR ARE EXPECTED ON MONDAY BEHIND THE COLD FRONT AS THE REGION DRIES OUT WITH HIGH PRESSURE MOVING IN AT THE SURFACE AND THE UPPER FLOW BECOMING ZONAL THROUGH THE MIDDLE OF THE WEEK. WARMER TEMPERATURES ARE EXPECTED THROUGH THE LATTER HALF OF THE WEEK AS THE LARGE AREA OF HIGH PRESSURE ALOFT EXPANDS ACROSS THE SOUTHERN UNITED STATES. THE UPPER FLOW TURNS MORE SOUTHWESTERLY AND A LEE TROUGH DEEPENS ALONG THE EASTERN COLORADO BORDER THROUGH THE LATTER HALF OF NEXT WEEK...BRINGING ANOTHER PERIOD OF ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE CENTRAL HIGH PLAINS EACH DAY AS DISTURBANCES MOVE OUT OF THE SOUTHWEST UNITED STATES...EAST OF THE ROCKIES...AND ACROSS THE PLAINS STATES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1137 PM MDT SAT AUG 30 2014 PERSISTENT VFR CONDITIONS EXPECTED THROUGH THIS TAF CYCLE. SHOWERS/ISOLATED STORMS ARE MOVING INTO KGLD SO HAVE PLACED VCTS BACK INTO TAF. KGLD VAD WIND PROFILE DEPICTS A LOW LEVEL JET OF 45 KTS OVER KGLD AT PRESENT TIME WITH RAP MODEL ANALYSIS INDICATING STRONG WINDS OVER KMCK. MAINTAINED LLWS IN TAF WITH OUTFLOW BOUNDARIES AND SOMEWHAT ERRATIC SURFACE WINDS MOVING THROUGH. FOR THIS AFTERNOON...PLACED VCTS INTO KMCK TAF AS CONVECTION IS EXPECTED TO DEVELOP AHEAD OF A VIGOROUS UPPER LEVEL DISTURBANCE. STORMS COULD PRODUCE STRONG WIND GUSTS IN EXCESS OF 50 KTS AND LARGE HAIL. NOT CONFIDENT ENOUGH TO PLACE TS INTO KGLD TAF AS MOST MODEL GUIDANCE REMAINS INSISTENT CONVECTION STAYS NORTHEAST. COLD FRONT SLIDES THROUGH DURING THE EVENING...BRINGING LIGHT NORTH WINDS AND CALM WEATHER BEHIND THE UPPER LEVEL DISTURBANCE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JN SHORT TERM...JRM LONG TERM...LOCKHART AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1137 PM MDT SAT AUG 30 2014 .UPDATE... ISSUED AT 854 PM MDT SAT AUG 30 2014 UPDATED THE FORECAST TO MAKE ADJUSTMENTS FOR THIS EVENING/TONIGHT AND INCLUDE LATEST GUIDANCE INTO SEVERE WEATHER CHANCES TOMORROW AFTERNOON/EVENING. FOR TONIGHT...LOWERED POPS AND MENTIONED ISOLATED THUNDER. ACTIVITY IS NOT IMPRESSIVE COMING IN FROM COLORADO AND CAP HAS LIMITED CONVECTION OVER THE TRI-STATE REGION. FORECAST STILL LOOKS GOOD FOR TOMORROW. BEST CHANCES FOR SEVERE WEATHER LIES ALONG AND WEST OF HIGHWAY 83. THERE COULD BE A CHANCE OF A TORNADO OR TWO NORTH AND EAST OF A LINE FROM TRENTON NEBRASKA TO HOXIE AND HILL CITY KANSAS. LCLS OF 1300-1600 METERS...FAVORABLE SHEAR AND TURNING OF WINDS IN BOUNDARY LAYER WILL PROVIDE AN ENVIRONMENT CONDUCIVE TO TORNADO DEVELOPMENT. MAIN THREATS ARE BE LARGE HAIL AND DAMAGING WINDS BUT COULD NOT RULE OUT A TORNADO OR TWO. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 1239 PM MDT SAT AUG 30 2014 18Z WATER VAPOR IMAGERY INDICATED SHORT WAVE RIDGING IN PLACE ACROSS THE NORTHERN PLAINS WITH NOTICEABLE SHORT WAVE TROUGH MOVING INTO UTAH. AT THE SURFACE...LEE TROUGH DEVELOPING ACROSS WESTERN CWA WITH SOUTHWESTERLY WINDS IN THE 10 TO 20 KT RANGE COMMON. PRIMARY FORECAST CONCERN WILL CENTER AROUND PRECIP CHANCES THIS EVENING AND AGAIN ON SUNDAY. TONIGHT...SHORT WAVE TROUGH CURRENTLY OVER UTAH WILL CONTINUE TO DRIFT TO THE EAST TONIGHT...WITH LARGE SCALE FORCING INCREASING BETWEEN 03 AND 09Z IN RESPONSE. INSTABILITY...BOTH SURFACE AND ELEVATED APPEAR TO BE VERY LIMITED SO DO NOT ANTICIPATE MANY STRONG/SEVERE STORMS. WHILE A FEW LATE AFTERNOON STORMS ARE POSSIBLE...DO EXPECT BEST CHANCES TO OCCUR WHEN LARGE SCALE FORCING/INCREASING LLJ ARE MAXIMIZED. TOMORROW...POTENTIAL FOR SEVERE THUNDERSTORMS...ESPECIALLY IN THE EASTERN CWA LOOKS ON TRACK AS FRONTAL BOUNDARY SLOWLY SAGS SOUTH ACROSS THE AREA. THINK BEST CHANCE FOR CONVECTIVE INITIATION WILL BE ALONG DEVELOPING DRY LINE TO THE THE SOUTH OF THE FRONTAL ZONE. WHILE STRONG INSTABILITY AND SHEAR EXIST TO THE NORTH OF FRONT...STRONG CAP MAKES ANY EARLY INITIATION UNLIKELY. A FEW STORMS COULD DEVELOP OVER THE HIGHER TERRAIN AND DRIFT INTO THE CWA...BUT THIS SCENARIO MOST LIKELY AFTER SUNSET. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 230 PM MDT SAT AUG 30 2014 MAIN FOCUS IS STILL ON THE POTENTIAL FOR SEVERE THUNDERSTORMS INTO SUNDAY EVENING AS SURFACE COLD FRONT MOVES ACROSS THE FORECAST AREA AND THE AXIS OF THE UPPER TROUGH SWEEPS ACROSS THE CENTRAL HIGH PLAINS REGION. WITH HIGHS IN THE 90S AND DEWPOINTS IN THE UPPER 50S TO LOWER 60S...INSTABILITY AND SHEAR SHOULD BE FAVORABLE FOR SUPERCELLS ACROSS THE EASTERN PORTION OF THE FORECAST AREA WITH LARGE HAIL AND ISOLATED TORNADOS TRANSITIONING INTO MAINLY A WIND THREAT BY LATE EVENING. COOLER...NEAR AVERAGE...TEMPERATURES FOR THIS TIME OF YEAR ARE EXPECTED ON MONDAY BEHIND THE COLD FRONT AS THE REGION DRIES OUT WITH HIGH PRESSURE MOVING IN AT THE SURFACE AND THE UPPER FLOW BECOMING ZONAL THROUGH THE MIDDLE OF THE WEEK. WARMER TEMPERATURES ARE EXPECTED THROUGH THE LATTER HALF OF THE WEEK AS THE LARGE AREA OF HIGH PRESSURE ALOFT EXPANDS ACROSS THE SOUTHERN UNITED STATES. THE UPPER FLOW TURNS MORE SOUTHWESTERLY AND A LEE TROUGH DEEPENS ALONG THE EASTERN COLORADO BORDER THROUGH THE LATTER HALF OF NEXT WEEK...BRINGING ANOTHER PERIOD OF ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE CENTRAL HIGH PLAINS EACH DAY AS DISTURBANCES MOVE OUT OF THE SOUTHWEST UNITED STATES...EAST OF THE ROCKIES...AND ACROSS THE PLAINS STATES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1137 PM MDT SAT AUG 30 2014 PERSISTENT VFR CONDITIONS EXPECTED THROUGH THIS TAF CYCLE. SHOWERS/ISOLATED STORMS ARE MOVING INTO KGLD SO HAVE PLACED VCTS BACK INTO TAF. KGLD VAD WIND PROFILE DEPICTS A LOW LEVEL JET OF 45 KTS OVER KGLD AT PRESENT TIME WITH RAP MODEL ANALYSIS INDICATING STRONG WINDS OVER KMCK. MAINTAINED LLWS IN TAF WITH OUTFLOW BOUNDARIES AND SOMEWHAT ERRATIC SURFACE WINDS MOVING THROUGH. FOR THIS AFTERNOON...PLACED VCTS INTO KMCK TAF AS CONVECTION IS EXPECTED TO DEVELOP AHEAD OF A VIGOROUS UPPER LEVEL DISTURBANCE. STORMS COULD PRODUCE STRONG WIND GUSTS IN EXCESS OF 50 KTS AND LARGE HAIL. NOT CONFIDENT ENOUGH TO PLACE TS INTO KGLD TAF AS MOST MODEL GUIDANCE REMAINS INSISTENT CONVECTION STAYS NORTHEAST. COLD FRONT SLIDES THROUGH DURING THE EVENING...BRINGING LIGHT NORTH WINDS AND CALM WEATHER BEHIND THE UPPER LEVEL DISTURBANCE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...RRH SHORT TERM...JRM LONG TERM...LOCKHART AVIATION...RRH
AREA FORECAST DISCUSSION
NWS JACKSON KY
1045 PM EDT MON SEP 1 2014 .UPDATE... ISSUED AT 1045 PM EDT MON SEP 1 2014 ISOLATED SHOWERS CONTINUE TO AFFECT NORTHERN KY...INCLUDING THE NORTHERN PART OF THE JACKSON FORECAST AREA. THE SHOWERS HAVE SHOWN A DECREASING TREND...AND THE TOTAL LIGHTNING DATA INDICATES THERE IS NO LONGER ANY LIGHTNING IN KY. CONVECTION CONTINUES TO DEVELOP ACROSS MO AND CENTRAL IL. BASED ON CURRENT TRENDS AND THE LATEST HRRR DATA THIS COULD IMPACT OUR AREA BEGINNING SOMETIME NEAR OF AFTER 12Z. HOURLY NDFD DATA HAS BEEN UPDATED FOR LATEST OBSERVATIONAL TRENDS. UPDATE ISSUED AT 751 PM EDT MON SEP 1 2014 ISOLATED THUNDERSTORMS CONTINUE TO AFFECT THE NORTHERN THIRD OF KY...INCLUDING THE NORTHERN PART OF THE JACKSON FORECAST AREA. WITH LOSS OF DAYTIME HEATING EXPECT THE ISOLATED CONVECTION TO CONTINUE TO WANE. HOWEVER A SHORT WAVE MOVING INTO MO IS RESULTING IN AN INCREASE IN SHOWERS AND THUNDERSTORMS AHEAD OF THE SURFACE COLD FRONT THERE...AND THE REMNANTS OF THIS CONVECTION MAY AFFECT THE NORTHERN PARTS OF THE FORECAST AREA LATE TONIGHT OR EARLY TUESDAY MORNING. THIS IDEA IS SUPPORTED BY THE LATEST HRRR AND THE 18Z NAM AND GFS. HAVE UPDATED NDFD FOR LATEST OBSERVATIONAL TRENDS AND WILL BE MAKING ADDITIONAL ADJUSTMENTS TO HOURLY WEATHER GRIDS SHORTLY. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 315 PM EDT MON SEP 1 2014 A LINE OF SCATTERED SHOWERS AND THUNDERSTORMS CONTINUES TO MOVE ACROSS EASTERN KENTUCKY. THIS LINE IS OUT AHEAD OF THE COLD FRONT IN THE WARM AIR. THERE IS A BIT OF CURVATURE TO THE LINE OF HEAVIEST STORMS;...SO WILL BE WATCHING FOR SOME POTENTIALLY STRONG WIND GUSTS AS THE LINE GOES THROUGH. THE MERCER AND LINCOLN COUNTY MESONET SITES SAW WIND GUSTS OF 30 MPH AS THE LINE WENT THROUGH AND BATH COUNTY SAW A GUST TO 41 MPH. CURRENT THINKING IS THE MAX GUSTS STAY AROUND 40 MPH WITH THE STRONGEST STORMS AND MOST GUSTS WILL BE IN THE 25 TO 35 MPH RANGE AS THE STORMS CONTINUE TO MOVE ACROSS EASTERN KENTUCKY. THESE STORMS WILL DROP BETWEEN 0.25 TO 0.75 INCHES OF RAIN AS IT MOVES ACROSS THE AREA. HAVE A LITTLE CONCERN FOR PARTS OF EASTERN KENTUCKY THAT GOT HAMMERED LAST NIGHT FROM THE HEAVY RAIN...HOWEVER THESE STORMS HAVE BEEN QUITE PROGRESSIVE AND HAVE NOT YET SEEN ANY TRAINING OF THE ECHOES. THIS LINE SHOULD CONTINUE TO MOVE ACROSS THE AREA AND THEN THE LEADING EDGE OF THE PREFRONTAL PRECIPITATION WILL BE MOVING INTO THE AREA LATER TONIGHT. THE FRONT WILL BE MOVING ACROSS THE AREA TOMORROW AND BRING WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE AREA. THERE WILL BE A SLIGHT RISK OF SEVERE THUNDERSTORMS TOMORROW. SPC CURRENTLY HAS MOST OF EASTERN KENTUCKY IN THE SLIGHT RISK AREA. THE MAIN THREAT WILL BE WINDS WITH A VERY WEAK THREAT FOR MARGINALLY SEVERE HAIL. MOST LIKELY...ANY HAIL WILL STAY IN THE 0.5 TO 0.75 INCH RANGE. THE PRECIPITATION WILL DROP OFF FAIRLY QUICKLY BEHIND THE FRONT. THE MODELS ARE IN VERY GOOD AGREEMENT WITH THE TIMING. WENT WITH THE MODEL BLEND FOR THE TEMPERATURES WITH JUST SOME ADJUSTMENTS DUE TO ELEVATION. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 315 PM EDT MON SEP 1 2014 THE MODELS BEGIN THE EXTENDED PERIOD IN PRETTY GOOD AGREEMENT ONCE AGAIN...WITH A RIDGE OF HIGH PRESSURE...BOTH ALOFT AND AT THE SURFACE...CENTERED OVER THE EASTERN GULF OF MEXICO...ALONG WITH A WELL DEFINED TROUGH OF LOW PRESSURE ALOFT TAKING SHAPE OVER THE NORTHERN PLAINS. THE MODELS HAVE THE RIDGE BREAKING DOWN CONSISTENTLY TO BEGIN THE PERIOD...WITH SHOWERS AND STORMS POPPING UP BENEATH IT ACROSS THE TENNESSEE VALLEY DOWN TO THE GULF. AS THE TROUGH EVOLVES AND STRENGTHENS...IT WILL EJECT OUT OF THE PLAINS WEDNESDAY NIGHT AND THURSDAY...AND PUSH ACROSS THE GREAT LAKES AND OHIO VALLEY REGIONS. THE COLD FRONT TRAILING FROM THIS UPPER LOW WILL END BEING OUR WEATHER MAKER FOR THE UPCOMING WEEKEND. THE FRONT IS EXPECTED TO INTERACT WITH MOISTURE COMING OFF THE GULF OF MEXICO ON SOUTHWESTERLY WINDS. THE FRONT WILL HAVE A DIFFICULT TIME MOVING EASTWARD...HOWEVER...AS THE RIDGE DIGS IN A BIT JUST OFF THE SOUTHEAST COAST AND FLOW ALOFT BECOMES MORE ZONAL. THERE WILL BE A GOOD CHANCE OF RAIN FRIDAY MORNING THROUGH SUNDAY MORNING...AS LIFT AND MOISTURE ALONG THE SLUGGISH FRONT SET OFF REPEATED ROUNDS OF SHOWERS AND STORMS. THE RAIN SHOULD FINALLY MOVE OUT OF THE AREA SUNDAY EVENING...AS THE FRONT FINALLY MOVES OUT OF THE AREA. TEMPERATURES TO BEGIN THE PERIOD LOOK TO BE ABOVE NORMAL...WITH HIGHS TOPPING OUT AROUND IN THE MID TO UPPER 80S WEDNESDAY THROUGH FRIDAY. ONCE THE FRONT STALLS ACROSS THE AREA AND PRECIPITATION BECOMES MORE WIDESPREAD...TEMPERATURES WILL LIKELY MAX OUT BELOW NORMAL VALUES SATURDAY THROUGH MONDAY. HIGHS ON FRIDAY WILL BE CLOSER TO NORMAL AS THE FRONT WILL STILL BE TO OUR WEST. ON SATURDAY AND SUNDAY...THE POSITIONING OF THE FRONT WILL ALLOW FOR SOME COOLER AND DRIER AIR TO FILTER INTO THE AREA. HIGHS ON SATURDAY SHOULD BE CLOSE TO NORMAL...AS THE BULK OF COOL AIR SHOULD STILL BE TRAPPED NORTH OF THE OHIO RIVER. ON SUNDAY...HOWEVER...ONCE WINDS HAVE SHIFTED TO THE NORTH...TEMPERATURES WILL BE QUITE COOL...WITH READINGS PEAKING IN THE MID TO UPPER 70S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 751 PM EDT MON SEP 1 2014 ISOLATED THUNDERSTORMS OVER NORTHERN KY...NORTH OF THE TAF SITES... WILL DIMINISH THIS EVENING. VFR CONDITIONS WILL PREVAIL UNTIL AFTER 06Z WHEN AREAS OF FOG WILL BEGIN TO FORM. MVFR CONDITIONS IN FOG ARE EXPECTED LATE TONIGHT AND EARLY TUESDAY MORNING...BUT ANY FOG WILL BURN OFF QUICKLY TUESDAY MORNING. VFR CONDITIONS WILL PREVAIL FOR MOST OF THE DAY ON TUESDAY...BUT AN APPROACHING COLD FRONT WILL BRING A THREAT OF THUNDERSTORMS DURING THE AFTERNOON AND EVENING. SOUTHWEST WINDS WILL BECOME GUSTY AHEAD OF THE COLD FRONT TUESDAY AFTERNOON...WITH SOME GUSTS IN EXCESS OF 15 KNOTS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SBH SHORT TERM...JJ LONG TERM...AR AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
752 PM EDT MON SEP 1 2014 .UPDATE... ISSUED AT 751 PM EDT MON SEP 1 2014 ISOLATED THUNDERSTORMS CONTINUE TO AFFECT THE NORTHERN THIRD OF KY...INCLUDING THE NORTHERN PART OF THE JACKSON FORECAST AREA. WITH LOSS OF DAYTIME HEATING EXPECT THE ISOLATED CONVECTION TO CONTINUE TO WANE. HOWEVER A SHORT WAVE MOVING INTO MO IS RESULTING IN AN INCREASE IN SHOWERS AND THUNDERSTORMS AHEAD OF THE SURFACE COLD FRONT THERE...AND THE REMNANTS OF THIS CONVECTION MAY AFFECT THE NORTHERN PARTS OF THE FORECAST AREA LATE TONIGHT OR EARLY TUESDAY MORNING. THIS IDEA IS SUPPORTED BY THE LATEST HRRR AND THE 18Z NAM AND GFS. HAVE UPDATED NDFD FOR LATEST OBSERVATIONAL TRENDS AND WILL BE MAKING ADDITIONAL ADJUSTMENTS TO HOURLY WEATHER GRIDS SHORTLY. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 315 PM EDT MON SEP 1 2014 A LINE OF SCATTERED SHOWERS AND THUNDERSTORMS CONTINUES TO MOVE ACROSS EASTERN KENTUCKY. THIS LINE IS OUT AHEAD OF THE COLD FRONT IN THE WARM AIR. THERE IS A BIT OF CURVATURE TO THE LINE OF HEAVIEST STORMS;...SO WILL BE WATCHING FOR SOME POTENTIALLY STRONG WIND GUSTS AS THE LINE GOES THROUGH. THE MERCER AND LINCOLN COUNTY MESONET SITES SAW WIND GUSTS OF 30 MPH AS THE LINE WENT THROUGH AND BATH COUNTY SAW A GUST TO 41 MPH. CURRENT THINKING IS THE MAX GUSTS STAY AROUND 40 MPH WITH THE STRONGEST STORMS AND MOST GUSTS WILL BE IN THE 25 TO 35 MPH RANGE AS THE STORMS CONTINUE TO MOVE ACROSS EASTERN KENTUCKY. THESE STORMS WILL DROP BETWEEN 0.25 TO 0.75 INCHES OF RAIN AS IT MOVES ACROSS THE AREA. HAVE A LITTLE CONCERN FOR PARTS OF EASTERN KENTUCKY THAT GOT HAMMERED LAST NIGHT FROM THE HEAVY RAIN...HOWEVER THESE STORMS HAVE BEEN QUITE PROGRESSIVE AND HAVE NOT YET SEEN ANY TRAINING OF THE ECHOES. THIS LINE SHOULD CONTINUE TO MOVE ACROSS THE AREA AND THEN THE LEADING EDGE OF THE PREFRONTAL PRECIPITATION WILL BE MOVING INTO THE AREA LATER TONIGHT. THE FRONT WILL BE MOVING ACROSS THE AREA TOMORROW AND BRING WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE AREA. THERE WILL BE A SLIGHT RISK OF SEVERE THUNDERSTORMS TOMORROW. SPC CURRENTLY HAS MOST OF EASTERN KENTUCKY IN THE SLIGHT RISK AREA. THE MAIN THREAT WILL BE WINDS WITH A VERY WEAK THREAT FOR MARGINALLY SEVERE HAIL. MOST LIKELY...ANY HAIL WILL STAY IN THE 0.5 TO 0.75 INCH RANGE. THE PRECIPITATION WILL DROP OFF FAIRLY QUICKLY BEHIND THE FRONT. THE MODELS ARE IN VERY GOOD AGREEMENT WITH THE TIMING. WENT WITH THE MODEL BLEND FOR THE TEMPERATURES WITH JUST SOME ADJUSTMENTS DUE TO ELEVATION. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 315 PM EDT MON SEP 1 2014 THE MODELS BEGIN THE EXTENDED PERIOD IN PRETTY GOOD AGREEMENT ONCE AGAIN...WITH A RIDGE OF HIGH PRESSURE...BOTH ALOFT AND AT THE SURFACE...CENTERED OVER THE EASTERN GULF OF MEXICO...ALONG WITH A WELL DEFINED TROUGH OF LOW PRESSURE ALOFT TAKING SHAPE OVER THE NORTHERN PLAINS. THE MODELS HAVE THE RIDGE BREAKING DOWN CONSISTENTLY TO BEGIN THE PERIOD...WITH SHOWERS AND STORMS POPPING UP BENEATH IT ACROSS THE TENNESSEE VALLEY DOWN TO THE GULF. AS THE TROUGH EVOLVES AND STRENGTHENS...IT WILL EJECT OUT OF THE PLAINS WEDNESDAY NIGHT AND THURSDAY...AND PUSH ACROSS THE GREAT LAKES AND OHIO VALLEY REGIONS. THE COLD FRONT TRAILING FROM THIS UPPER LOW WILL END BEING OUR WEATHER MAKER FOR THE UPCOMING WEEKEND. THE FRONT IS EXPECTED TO INTERACT WITH MOISTURE COMING OFF THE GULF OF MEXICO ON SOUTHWESTERLY WINDS. THE FRONT WILL HAVE A DIFFICULT TIME MOVING EASTWARD...HOWEVER...AS THE RIDGE DIGS IN A BIT JUST OFF THE SOUTHEAST COAST AND FLOW ALOFT BECOMES MORE ZONAL. THERE WILL BE A GOOD CHANCE OF RAIN FRIDAY MORNING THROUGH SUNDAY MORNING...AS LIFT AND MOISTURE ALONG THE SLUGGISH FRONT SET OFF REPEATED ROUNDS OF SHOWERS AND STORMS. THE RAIN SHOULD FINALLY MOVE OUT OF THE AREA SUNDAY EVENING...AS THE FRONT FINALLY MOVES OUT OF THE AREA. TEMPERATURES TO BEGIN THE PERIOD LOOK TO BE ABOVE NORMAL...WITH HIGHS TOPPING OUT AROUND IN THE MID TO UPPER 80S WEDNESDAY THROUGH FRIDAY. ONCE THE FRONT STALLS ACROSS THE AREA AND PRECIPITATION BECOMES MORE WIDESPREAD...TEMPERATURES WILL LIKELY MAX OUT BELOW NORMAL VALUES SATURDAY THROUGH MONDAY. HIGHS ON FRIDAY WILL BE CLOSER TO NORMAL AS THE FRONT WILL STILL BE TO OUR WEST. ON SATURDAY AND SUNDAY...THE POSITIONING OF THE FRONT WILL ALLOW FOR SOME COOLER AND DRIER AIR TO FILTER INTO THE AREA. HIGHS ON SATURDAY SHOULD BE CLOSE TO NORMAL...AS THE BULK OF COOL AIR SHOULD STILL BE TRAPPED NORTH OF THE OHIO RIVER. ON SUNDAY...HOWEVER...ONCE WINDS HAVE SHIFTED TO THE NORTH...TEMPERATURES WILL BE QUITE COOL...WITH READINGS PEAKING IN THE MID TO UPPER 70S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 751 PM EDT MON SEP 1 2014 ISOLATED THUNDERSTORMS OVER NORTHERN KY...NORTH OF THE TAF SITES... WILL DIMINISH THIS EVENING. VFR CONDITIONS WILL PREVAIL UNTIL AFTER 06Z WHEN AREAS OF FOG WILL BEGIN TO FORM. MVFR CONDITIONS IN FOG ARE EXPECTED LATE TONIGHT AND EARLY TUESDAY MORNING...BUT ANY FOG WILL BURN OFF QUICKLY TUESDAY MORNING. VFR CONDITIONS WILL PREVAIL FOR MOST OF THE DAY ON TUESDAY...BUT AN APPROACHING COLD FRONT WILL BRING A THREAT OF THUNDERSTORMS DURING THE AFTERNOON AND EVENING. SOUTHWEST WINDS WILL BECOME GUSTY AHEAD OF THE COLD FRONT TUESDAY AFTERNOON...WITH SOME GUSTS IN EXCESS OF 15 KNOTS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SBH SHORT TERM...JJ LONG TERM...AR AVIATION...SBH
AREA FORECAST DISCUSSION
NWS PADUCAH KY
238 PM CDT Sun Aug 31 2014 .SHORT TERM...(Tonight through Tuesday night) Issued at 238 PM CDT SUN AUG 31 2014 Wvapor and RAP data shows subtle mid level wave moving slowly east across the area. Convection near SEMO making little eastward progress. Tiny showers over west KY moving east as well. Will keep PoPs limited through the early evening before ending them from west to east overnight. Frontal boundary will approach the area Monday night. Best chance of activity will be over far north and west sections of the area. Cannot rule out isolated anywhere, but chances too low down into west KY to include for now. Moisture is increasingly limited south of the Ohio. PoPs will rise from NW to SE Monday night as the front settles south toward the area. Again best chances north, lowering south. Tuesday the front will stall somewhere across the area, with upper level support moving across the region. Thus the chance of convection continues. We could see some strong storms Tuesday given degree of forecast instability, and an uptick in the mean flow 850-500mb. Tuesday night we will drop off PoPs in the wake of the upper system. However more activity could move into or toward SEMO toward daybreak Wednesday. Temps will be a blend of existing numbers and the latest blend of raw model output. .LONG TERM...(Wednesday through Sunday) Issued at 238 PM CDT SUN AUG 31 2014 By Wednesday morning, whatever is left of the frontal boundary that went through the area the night before, will be situated somewhere over our southern counties. The front will be lifting back north as a warm front and this is seen most evidently in the theta e fields. This rebounding front along with minor perturbations in the zonal flow aloft will likely lead to some convection, especially given the decent mid level lapse rates, sfc instability parameters and deep moisture. The upper wave will move off to the east Wednesday night and things should be fairly quiet except for some possible lingering afternoon convection. On Thursday, the upper ridge really begins building over the region and become centered over us by the end of the day. This should help boost temperatures up a degree or two into the lower 90s. We should not see widespread chances for storms though on Thursday, but it appears as though a small chance will remain, with the best chances in the east where the better moisture will be confined. Meanwhile, a frontal boundary will be progressing eastward across the upper Midwest down into the Central Plains. This front will be slow to move and models have not been handling its speed very well. Todays runs of the GFS and ECMWF show a faster progression and have the front into the area by Friday or Friday night. The best moisture and QPF is behind the actual front so precipitation chances ramp up by Friday night into Saturday. Beyond Saturday, models were having a rough time resolving how quickly the moisture gets shoved out of the area and this is due to the differences in the strength and progression of the sfc high originating from the north central plains states. But the 12Z model runs of the GFS and ECMWF have finally aligned well and believe that Sunday (and even Saturday night) should be dry now. In fact, much drier and cooler air settling in with highs probably in the 70s on Sunday. && .AVIATION... Issued at 238 PM CDT SUN AUG 31 2014 Conditions continue to improve given diurnal aspect and with deeper moisture heading east. Will linger mainly VFR Cu through the end of the day, with any pockets of MVFR east of a KEVV to KCEY line giving way to VFR. Chance of convection too low to include at any of the Terminals. Not too concerned with fog tonight. Cannot rule out some low cloud development based on moisture transport of respectable moisture still across the area below 4k/ft. Wind should stay up enough to preclude a real fog concern. SSW winds will pick up mid morning Labor day, 10 kts or so, with some CU expected. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$
AREA FORECAST DISCUSSION
NWS JACKSON KY
130 PM EDT SUN AUG 31 2014 .UPDATE... ISSUED AT 130 PM EDT SUN AUG 31 2014 UPDATED THE FORECAST GRIDS AND FLASH FLOOD WATCH EARLIER THIS AFTERNOON. SHOWERS AND STORMS ARE ONGOING ACROSS THE AREA...WITH NEW ACTIVITY BEGINNING TO POP UP IN CENTRAL TENNESSEE AND ALABAMA. AFTER A LULL IN ACTIVITY...NUMEROUS SHOWERS AND STORMS ARE EXPECTED TO MOVE BACK INTO THE AREA LATER THIS AFTERNOON INTO THIS EVENING. THE FLASH FLOOD WATCH IS GOOD UNTIL 6 PM TODAY. WILL CONTINUE TO MONITOR THE SITUATION TO SEE WHETHER OR NOT WE CAN SHAVE SOME COUNTIES OFF OR CANCEL IT ALTOGETHER BY THE 4 PM AFTERNOON FORECAST PACKAGE ISSUANCE. THE FORECAST IS PRETTY MUCH ON TRACK FOR THE DAY SO NO MAJOR CHANGES HAVE BEEN PLANNED AS OF YET. UPDATE ISSUED AT 720 AM EDT SUN AUG 31 2014 THE BAND OF RAIN OVER CENTRAL KY IS GRADUALLY WORKING INTO EASTERN KY. ACTIVITY OVER THE NEXT FEW HOURS SHOULD MAINLY BE ACROSS THE WESTERN AND NORTHWESTERN LOCATIONS. ACTIVITY SHOULD INCREASE IN INTENSITY FROM MIDDAY INTO THE AFTERNOON HOURS AND LOCALLY HEAVY RAIN WILL BE POSSIBLE GIVEN THE VERY MOIST AIR MASS IN PLACE ACROSS THE REGION. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 335 AM EDT SUN AUG 31 2014 EARLY THIS MORNING...THE REGION REMAINED IN A VERY MOIST AIR MASS WITH PW OF 2 INCHES OR MORE EXTENDING INTO THE OHIO VALLEY REGION BETWEEN A RIDGE OF HIGH PRESSURE CENTERED OFF THE SOUTHEAST US COAST AND A SHORTWAVE TROUGH EXTENDING SOUTH FROM THE GREAT LAKES INTO THE MS VALLEY REGION. A LULL IN THE SHOWER AND THUNDERSTORM ACTIVITY IS WORKING NORTH AND NORTHEAST ACROSS THE CWA ATTM AS THE FIRST WAVE IS BEGINNING TO DEPART. HOWEVER...THE NEXT WAVE IS WORKING INTO THE MID MS AND LOWER OH VALLEY REGION AS THE DEEP MOISTURE PLUME REMAINS. OVER THE NEXT COUPLE OF DAYS...THE INITIAL WAVE WILL DEPART TO THE NORTH AND NORTHEAST...BUT THE NEXT MOST EVIDENT AT THE 850 MB AND 700 MB LEVEL IS EXPECTED TO TRACK EAST NORTHEAST ACROSS THE OH VALLEY REGION TODAY. THIS SYSTEM SHOULD ONCE AGAIN INTERACT WITH THE DEEP MOISTURE PLUME IN PLACE ACROSS THE REGION AND LEAD TO RENEWED CONVECTIVE ACTIVITY TO OUR WEST GRADUALLY TRANSITIONING INTO EASTERN KY LATER TONIGHT AND INTO THE DAY ON SUNDAY. THIS SYSTEM WILL DEPART TO THE NORTH AND EAST TONIGHT. THE SOUTHEASTERN RIDGE IS EXPECTED TO FLATTEN BY TONIGHT AND INTO MONDAY. THE NEXT TROUGH WILL HAVE MOVED INTO THE UPPER MS VALLEY REGION AND PLAINS FROM THE ROCKIES BY LATE TONIGHT...WITH THIS TROUGH WORKING INTO THE GREAT LAKES AND APPROACHING THE LOWER OH VALLEY REGION LATE IN THE PERIOD. THE ASSOCIATED SFC COLD FRONT IS ALSO EXPECTED TO APPROACH THE LOWER OH VALLEY REGION LATE IN THE PERIOD...BUT WILL HAVE MORE OF AN EFFECT ON THE LONG TERM PORTION OF THE FORECAST. RECENT HRRR RUNS BRING THE STRONGEST ACTIVITY ACROSS THE REGION DURING THE AFTERNOON INTO THE EARLY EVENING ON SUNDAY. THIS ACTIVITY SHOULD BE EFFICIENT RAIN PRODUCERS AND WHERE ANY TRAINING OCCURS LOCALLY HEAVY RAIN AND FLASH FLOODING WILL BE POSSIBLE. A FLASH FLOOD WATCH IS ALREADY IN PLACE ACROSS WESTERN AND NORTHWESTERN PARTS OF THE CWA ATTM AND WE PLAN TO KEEP IT IN PLACE WITH NO CHANGES. LATER SHIFTS MAY WANT TO CONSIDER EXTENDING IT FURTHER SOUTH AND EAST...BUT RAINFALL OVER THE PAST 24 HOURS HAS BEEN GENERALLY LIGHTER THERE COMPARED TO THE SOUTHWESTERN PART OF THE CWA WHERE RADAR ESTIMATES AND RAIN GAGES INDICATE THAT UPWARDS OF 2 INCHES OR MORE HAS FALLEN ACROSS PARTS OF WAYNE COUNTY AND FROM MCCREARY COUNTY NORTHEAST INTO LAUREL COUNTY. TEMPERATURES TODAY SHOULD BE SUPPRESSED BELOW SATURDAYS LEVELS BY THE ANTICIPATED CLOUD COVER AND PRECIPITATION. LOCALLY HEAVY RAIN WILL BE MENTIONED IN THE HWO OUTSIDE OF LOCATIONS CURRENTLY IN THE FLASH FLOOD WATCH. WITH THE WAVE DEPARTING TONIGHT...CHANCES FOR CONVECTION WILL ALSO DIMINISH. MIN TEMPERATURES WILL REMAIN ON THE MILD SIDE. AT LEAST PATCHY VALLEY FOG SHOULD DEVELOP...WHERE ANY PARTIAL CLEARING OCCURS. ON MONDAY...THE REGION WILL MORE OR LESS BE IN BETWEEN SYSTEMS WITH CONTINUED SOUTHERLY FLOW AND NOT MUCH IN THE WAY OF FORCING. MAX TEMPERATURES WILL AGAIN BE A FEW DEGREES ABOVE NORMAL AND COULD APPROACH 90 IN SOME LOCATIONS. THE DAYTIME HEATING OF THE WARM AND RATHER MOIST AIR MASS IN PLACE BY THE AFTERNOON SHOULD LEAD TO SOME DIURNALLY DRIVEN CONVECTION FOR MONDAY. AT THIS TIME...ONLY ISOLATED POPS WERE USED. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 252 AM EDT SUN AUG 31 2014 SUMMER-LIKE WEATHER WILL PERSIST THIS WEEK WITH PLENTY OF WARM AND HUMID CONDITIONS ON TAP. A STRONG RIDGE WILL CONTINUE TO RESIDE OVER THE SOUTHEAST THROUGH THE WEEK. BEST CHANCE OF RAIN WILL COME ON TUESDAY AS A SURFACE TROUGH DROPS INTO EASTERN KENTUCKY BEFORE STALLING. SOME WEAK FORCING WILL YIELD SCATTERED TO NUMEROUS SHOWERS AND STORMS THROUGH THE AFTERNOON AND EVENING HOURS. DECENT SHEAR PROFILES...COMBINED WITH MODEST INSTABILITY COULD YIELD THE POSSIBILITY OF A FEW STRONG TO SEVERE STORMS ON TUESDAY WITH THE MAIN THREAT BEING DAMAGING WINDS. OTHERWISE...THE FRONT WILL STALL OVER THE AREA TUESDAY NIGHT...AND VIRTUALLY WASH OUT. THE THREAT FOR AFTERNOON/EVENING SHOWERS WILL CONTINUE THROUGH WEEKS END GIVEN THE DAYTIME INSTABILITY EACH AFTERNOON/EVENING. TEMPERATURES WILL REMAIN NEAR OR SLIGHT ABOVE NORMAL THROUGH THE WEEK WITH ALL THE COOLER AIR BOTTLED UP WELL TO OUR NORTH. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 130 PM EDT SUN AUG 31 2014 MVFR CONDITIONS CAN BE EXPECTED AT THE TAF SITES THROUGH AROUND 13Z ON MONDAY...AS RAIN AND FOG FROM SHOWER AND STORM ACTIVITY AFFECT THE TAF AIRPORTS. THE SHOWERS AND STORMS ARE EXPECTED TO TAPER OFF QUICKLY AFTER 0Z THIS EVENING...WITH ISOLATED ACTIVITY AT BEST ACROSS THE AREA AFTER 8Z. EASTERN KENTUCKY MIGHT EVEN BE RAIN FREE DURING THE MORNING HOURS ON MONDAY...BEFORE SHOWERS AND STORMS BEGIN FIRING UP AGAIN MONDAY AFTERNOON DURING PEAK HEATING AND AS YET ANOTHER ATMOSPHERIC WAVE MOVES ACROSS THE REGION. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 6 PM EDT THIS EVENING FOR KYZ044-050>052- 058>060-068-069-079-080-083>086-104-106-108-111-114-116. && $$ UPDATE...AR SHORT TERM...JP LONG TERM...KAS AVIATION...AR
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
730 AM EDT SUN AUG 31 2014 .UPDATE... ISSUED AT 720 AM EDT SUN AUG 31 2014 THE BAND OF RAIN OVER CENTRAL KY IS GRADUALLY WORKING INTO EASTERN KY. ACTIVITY OVER THE NEXT FEW HOURS SHOULD MAINLY BE ACROSS THE WESTERN AND NORTHWESTERN LOCATIONS. ACTIVITY SHOULD INCREASE IN INTENSITY FROM MIDDAY INTO THE AFTERNOON HOURS AND LOCALLY HEAVY RAIN WILL BE POSSIBLE GIVEN THE VERY MOIST AIRMASS IN PLACE ACROSS THE REGION. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 335 AM EDT SUN AUG 31 2014 EARLY THIS MORNING...THE REGION REMAINED IN A VERY MOIST AIRMASS WITH PW OF 2 INCHES OR MORE EXTENDING INTO THE OHIO VALLEY REGION BETWEEN A RIDGE OF HIGH PRESSURE CENTERED OFF THE SOUTHEAST US COAST AND A SHORTWAVE TROUGH EXTENDING SOUTH FROM THE GREAT LAKES INTO THE MS VALLEY REGION. A LULL IN THE SHOWER AND THUNDERSTORM ACTIVITY IS WORKING NORTH AND NORTHEAST ACROSS THE CWA ATTM AS THE FIRST WAVE IS BEGINNING TO DEPART. HOWEVER...THE NEXT WAVE IS WORKING INTO THE MID MS AND LOWER OH VALLEY REGION AS THE DEEP MOISTURE PLUME REMAINS. OVER THE NEXT COUPLE OF DAYS...THE INITIAL WAVE WILL DEPART TO THE NORTH AND NORTHEAST...BUT THE NEXT MOST EVIDENT AT THE 850 MB AND 700 MB LEVEL IS EXPECTED TO TRACK EAST NORTHEAST ACROSS THE OH VALLEY REGION TODAY. THIS SYSTEM SHOULD ONCE AGAIN INTERACT WITH THE DEEP MOISTURE PLUME IN PLACE ACROSS THE REGION AND LEAD TO RENEWED CONVECTIVE ACTIVITY TO OUR WEST GRADUALLY TRANSITIONING INTO EASTERN KY LATER TONIGHT AND INTO THE DAY ON SUNDAY. THIS SYSTEM WILL DEPART TO THE NORTH AND EAST TONIGHT. THE SOUTHEASTERN RIDGE IS EXPECTED TO FLATTEN BY TONIGHT AND INTO MONDAY. THE NEXT TROUGH WILL HAVE MOVED INTO THE UPPER MS VALLEY REGION AND PLAINS FROM THE ROCKIES BY LATE TONIGHT...WITH THIS TROUGH WORKING INTO THE GREAT LAKES AND APPROACHING THE LOWER OH VALLEY REGION LATE IN THE PERIOD. THE ASSOCIATED SFC COLD FRONT IS ALSO EXPECTED TO APPROACH THE LOWER OH VALLEY REGION LATE IN THE PERIOD...BUT WILL HAVE MORE OF AN EFFECT ON THE LONG TERM PORTION OF THE FORECAST. RECENT HRRR RUNS BRING THE STRONGEST ACTIVITY ACROSS THE REGION DURING THE AFTERNOON INTO THE EARLY EVENING ON SUNDAY. THIS ACTIVITY SHOULD BE EFFICIENT RAIN PRODUCERS AND WHERE ANY TRAINING OCCURS LOCALLY HEAVY RAIN AND FLASH FLOODING WILL BE POSSIBLE. A FLASH FLOOD WATCH IS ALREADY IN PLACE ACROSS WESTERN AND NORTHWESTERN PARTS OF THE CWA ATTM AND WE PLAN TO KEEP IT IN PLACE WITH NO CHANGES. LATER SHIFTS MAY WANT TO CONSIDER EXTENDING IT FURTHER SOUTH AND EAST...BUT RAINFALL OVER THE PAST 24 HOURS HAS BEEN GENERALLY LIGHTER THERE COMPARED TO THE SOUTHWESTERN PART OF THE CWA WHERE RADAR ESTIMATES AND RAIN GAGES INDICATE THAT UPWARDS OF 2 INCHES OR MORE HAS FALLEN ACROSS PARTS OF WAYNE COUNTY AND FROM MCCREARY COUNTY NORTHEAST INTO LAUREL COUNTY. TEMPERATURES TODAY SHOULD BE SUPPRESSED BELOW SATURDAYS LEVELS BY THE ANTICIPATED CLOUD COVER AND PRECIPITATION. LOCALLY HEAVY RAIN WILL BE MENTIONED IN THE HWO OUTSIDE OF LOCATIONS CURRENTLY IN THE FLASH FLOOD WATCH. WITH THE WAVE DEPARTING TONIGHT...CHANCES FOR CONVECTION WILL ALSO DIMINISH. MIN TEMPERATURES WILL REMAIN ON THE MILD SIDE. AT LEAST PATCHY VALLEY FOG SHOULD DEVELOP...WHERE ANY PARTIAL CLEARING OCCURS. ON MONDAY...THE REGION WILL MORE OR LESS BE IN BETWEEN SYSTEMS WITH CONTINUED SOUTHERLY FLOW AND NOT MUCH IN THE WAY OF FORCING. MAX TEMPERATURES WILL AGAIN BE A FEW DEGREES ABOVE NORMAL AND COULD APPROACH 90 IN SOME LOCATIONS. THE DAYTIME HEATING OF THE WARM AND RATHER MOIST AIRMASS IN PLACE BY THE AFTERNOON SHOULD LEAD TO SOME DIURNALLY DRIVEN CONVECTION FOR MONDAY. AT THIS TIME...ONLY ISOLATED POPS WERE USED. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 252 AM EDT SUN AUG 31 2014 SUMMER-LIKE WEATHER WILL PERSIST THIS WEEK WITH PLENTY OF WARM AND HUMID CONDITIONS ON TAP. A STRONG RIDGE WILL CONTINUE TO RESIDE OVER THE SOUTHEAST THROUGH THE WEEK. BEST CHANCE OF RAIN WILL COME ON TUESDAY AS A SURFACE TROUGH DROPS INTO EASTERN KENTUCKY BEFORE STALLING. SOME WEAK FORCING WILL YIELD SCATTERED TO NUMEROUS SHOWERS AND STORMS THROUGH THE AFTERNOON AND EVENING HOURS. DECENT SHEAR PROFILES...COMBINED WITH MODEST INSTABILITY COULD YIELD THE POSSIBILITY OF A FEW STRONG TO SEVERE STORMS ON TUESDAY WITH THE MAIN THREAT BEING DAMAGING WINDS. OTHERWISE...THE FRONT WILL STALL OVER THE AREA TUESDAY NIGHT...AND VIRTUALLY WASH OUT. THE THREAT FOR AFTERNOON/EVENING SHOWERS WILL CONTINUE THROUGH WEEKS END GIVEN THE DAYTIME INSTABILITY EACH AFTERNOON/EVENING. TEMPERATURES WILL REMAIN NEAR OR SLIGHT ABOVE NORMAL THROUGH THE WEEK WITH ALL THE COOLER AIR BOTTLED UP WELL TO OUR NORTH. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 725 AM EDT SUN AUG 31 2014 ANOTHER WAVE WILL MOVE NORTHEAST AND INTERACT WITH ABUNDANT MOISTURE TO BRING A BAND OF RAIN SHOWERS AND SOME EMBEDDED TSRA INTO THE WESTERN PART OF THE AREA DURING THE FIRST FEW HOURS OF THE PERIOD. THIS WILL LOWER CIGS GRADUALLY DOWN TOWARD THE MVFR RANGE. AS THE DISTURBANCE WORKS OVERHEAD THIS AFTERNOON...STRONGER THUNDERSTORMS MAY DEVELOP WITH LOCALLY HEAVY RAIN. CONFIDENCE IN EXACT TIMING OF THIS IS LOW AT THIS TIME. CONVECTION SHOULD DIMINISH DURING THE 22Z TO 4Z PERIOD. PATCHY VALLEY FOG MAY DEVELOP LATE IN THE PERIOD IN THE DEEPER VALLEYS...BUT MAY NOT AFFECT THE TAF SITES. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 6 PM EDT THIS EVENING FOR KYZ044-050>052- 058>060-068-069-079-080-083>086-104-106-108-111-114-116. && $$ UPDATE...JP SHORT TERM...JP LONG TERM...KAS AVIATION...JP
AREA FORECAST DISCUSSION
NWS JACKSON KY
342 AM EDT SUN AUG 31 2014 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 335 AM EDT SUN AUG 31 2014 EARLY THIS MORNING...THE REGION REMAINED IN A VERY MOIST AIRMASS WITH PW OF 2 INCHES OR MORE EXTENDING INTO THE OHIO VALLEY REGION BETWEEN A RIDGE OF HIGH PRESSURE CENTERED OFF THE SOUTHEAST US COAST AND A SHORTWAVE TROUGH EXTENDING SOUTH FROM THE GREAT LAKES INTO THE MS VALLEY REGION. A LULL IN THE SHOWER AND THUNDERSTORM ACTIVITY IS WORKING NORTH AND NORTHEAST ACROSS THE CWA ATTM AS THE FIRST WAVE IS BEGINNING TO DEPART. HOWEVER...THE NEXT WAVE IS WORKING INTO THE MID MS AND LOWER OH VALLEY REGION AS THE DEEP MOISTURE PLUME REMAINS. OVER THE NEXT COUPLE OF DAYS...THE INITIAL WAVE WILL DEPART TO THE NORTH AND NORTHEAST...BUT THE NEXT MOST EVIDENT AT THE 850 MB AND 700 MB LEVEL IS EXPECTED TO TRACK EAST NORTHEAST ACROSS THE OH VALLEY REGION TODAY. THIS SYSTEM SHOULD ONCE AGAIN INTERACT WITH THE DEEP MOISTURE PLUME IN PLACE ACROSS THE REGION AND LEAD TO RENEWED CONVECTIVE ACTIVITY TO OUR WEST GRADUALLY TRANSITIONING INTO EASTERN KY LATER TONIGHT AND INTO THE DAY ON SUNDAY. THIS SYSTEM WILL DEPART TO THE NORTH AND EAST TONIGHT. THE SOUTHEASTERN RIDGE IS EXPECTED TO FLATTEN BY TONIGHT AND INTO MONDAY. THE NEXT TROUGH WILL HAVE MOVED INTO THE UPPER MS VALLEY REGION AND PLAINS FROM THE ROCKIES BY LATE TONIGHT...WITH THIS TROUGH WORKING INTO THE GREAT LAKES AND APPROACHING THE LOWER OH VALLEY REGION LATE IN THE PERIOD. THE ASSOCIATED SFC COLD FRONT IS ALSO EXPECTED TO APPROACH THE LOWER OH VALLEY REGION LATE IN THE PERIOD...BUT WILL HAVE MORE OF AN EFFECT ON THE LONG TERM PORTION OF THE FORECAST. RECENT HRRR RUNS BRING THE STRONGEST ACTIVITY ACROSS THE REGION DURING THE AFTERNOON INTO THE EARLY EVENING ON SUNDAY. THIS ACTIVITY SHOULD BE EFFICIENT RAIN PRODUCERS AND WHERE ANY TRAINING OCCURS LOCALLY HEAVY RAIN AND FLASH FLOODING WILL BE POSSIBLE. A FLASH FLOOD WATCH IS ALREADY IN PLACE ACROSS WESTERN AND NORTHWESTERN PARTS OF THE CWA ATTM AND WE PLAN TO KEEP IT IN PLACE WITH NO CHANGES. LATER SHIFTS MAY WANT TO CONSIDER EXTENDING IT FURTHER SOUTH AND EAST...BUT RAINFALL OVER THE PAST 24 HOURS HAS BEEN GENERALLY LIGHTER THERE COMPARED TO THE SOUTHWESTERN PART OF THE CWA WHERE RADAR ESTIMATES AND RAIN GAGES INDICATE THAT UPWARDS OF 2 INCHES OR MORE HAS FALLEN ACROSS PARTS OF WAYNE COUNTY AND FROM MCCREARY COUNTY NORTHEAST INTO LAUREL COUNTY. TEMPERATURES TODAY SHOULD BE SUPPRESSED BELOW SATURDAYS LEVELS BY THE ANTICIPATED CLOUD COVER AND PRECIPITATION. LOCALLY HEAVY RAIN WILL BE MENTIONED IN THE HWO OUTSIDE OF LOCATIONS CURRENTLY IN THE FLASH FLOOD WATCH. WITH THE WAVE DEPARTING TONIGHT...CHANCES FOR CONVECTION WILL ALSO DIMINISH. MIN TEMPERATURES WILL REMAIN ON THE MILD SIDE. AT LEAST PATCHY VALLEY FOG SHOULD DEVELOP...WHERE ANY PARTIAL CLEARING OCCURS. ON MONDAY...THE REGION WILL MORE OR LESS BE IN BETWEEN SYSTEMS WITH CONTINUED SOUTHERLY FLOW AND NOT MUCH IN THE WAY OF FORCING. MAX TEMPERATURES WILL AGAIN BE A FEW DEGREES ABOVE NORMAL AND COULD APPROACH 90 IN SOME LOCATIONS. THE DAYTIME HEATING OF THE WARM AND RATHER MOIST AIRMASS IN PLACE BY THE AFTERNOON SHOULD LEAD TO SOME DIURNALLY DRIVEN CONVECTION FOR MONDAY. AT THIS TIME...ONLY ISOLATED POPS WERE USED. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 252 AM EDT SUN AUG 31 2014 SUMMER-LIKE WEATHER WILL PERSIST THIS WEEK WITH PLENTY OF WARM AND HUMID CONDITIONS ON TAP. A STRONG RIDGE WILL CONTINUE TO RESIDE OVER THE SOUTHEAST THROUGH THE WEEK. BEST CHANCE OF RAIN WILL COME ON TUESDAY AS A SURFACE TROUGH DROPS INTO EASTERN KENTUCKY BEFORE STALLING. SOME WEAK FORCING WILL YIELD SCATTERED TO NUMEROUS SHOWERS AND STORMS THROUGH THE AFTERNOON AND EVENING HOURS. DECENT SHEAR PROFILES...COMBINED WITH MODEST INSTABILITY COULD YIELD THE POSSIBILITY OF A FEW STRONG TO SEVERE STORMS ON TUESDAY WITH THE MAIN THREAT BEING DAMAGING WINDS. OTHERWISE...THE FRONT WILL STALL OVER THE AREA TUESDAY NIGHT...AND VIRTUALLY WASH OUT. THE THREAT FOR AFTERNOON/EVENING SHOWERS WILL CONTINUE THROUGH WEEKS END GIVEN THE DAYTIME INSTABILITY EACH AFTERNOON/EVENING. TEMPERATURES WILL REMAIN NEAR OR SLIGHT ABOVE NORMAL THROUGH THE WEEK WITH ALL THE COOLER AIR BOTTLED UP WELL TO OUR NORTH. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 215 AM EDT SUN AUG 31 2014 MVFR OR IFR VIS AND OR CIGS ARE ANTICIPATED AS THE BAND OF CONVECTION WORKS ACROSS THE EASTERN AND NORTHEASTERN PART OF THE CWA OVER THE NEXT 2 TO 3 HOURS. VFR HAS DEVELOPED BEHIND THIS BAND OF PRECIPITATION AND AS THE LULL IN THE ACTIVITY WORKS NORTH ACROSS EAST KY...VFR CIGS ARE ANTICIPATED UNTIL AT LEAST THE 12Z TO 15Z RANGE. THE PRESS GRADIENT APPEARS GREAT ENOUGH TO KEEP THE TAF SITES MIXY OVERNIGHT...BUT SOME MVFR OR LOWER VALLEY FOG MAY STILL DEVELOP BETWEEN 6Z AND 12Z AT NON TAF SITES. MORE SHOWERS AND SOME THUNDER MAY DEVELOP AGAIN DURING THE 15Z TO 18Z PERIOD...WITH THIS ACTIVITY DIMINISHING BY THE LAST 6 HOURS OF THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR KYZ044-050>052- 058>060-068-069-079-080-083>086-104-106-108-111-114-116. && $$ SHORT TERM...JP LONG TERM...KAS AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
649 PM EDT SUN AUG 31 2014 .SYNOPSIS... A COLD FRONT WILL DROP SOUTHEAST THROUGH THE REGION O0VERNIGHT AND WILL STALL OFF THE COAST ON MONDAY. A SECOND COLD FRONT WILL APPROACH FROM THE WEST ON TUESDAY AND WILL CROSS THE REGION TUESDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE WEST ON WEDNESDAY AND WILL CREST OVER THE REGION THURSDAY BEFORE SHIFTING OFFSHORE. HIGH PRESSURE WILL HOLD OFF THE NEW ENGLAND COAST ON FRIDAY. A COLD FRONT WILL CROSS THE AREA ON SATURDAY. && .NEAR TERM /THROUGH MONDAY/... UPDATE...LIGHT SHOWERS CONTINUE TO MOVE ACROSS THE BULK OF THE CWFA ATTM. THIS HAS STABILIZED THE VAST MAJORITY OF THE AREA. THE LINGERING INSTABILITY AXIS...FROM EARLIER DAYTIME HEATING...REMAINS ACROSS SERN NH. THIS IS WHERE ANY STRONGER CONVECTION WILL BE WATCHED TO DEVELOP. CURRENTLY ONE STRONGER SHOWER IS MOVING TOWARDS THIS AREA...BUT ATTM HEAVY RNFL APPEAR TO BE THE GREATEST THREAT. HOWEVER...CAPE VALUES REMAIN BETWEEN 500-1000 J/KG PER SPC MESOANALYSIS. WILL MAINTAIN THE GUSTY WIND AND HEAVY RNFL WORDING IN THE GRIDS...AND JUST ADJUST POP TO BETTER REFLECT RADAR TRENDS AT THIS HOUR. WILL ALSO WATCH FOR A SECOND ROUND OF CONVECTION ACROSS THE NRN ZONES...AS S/WV TROF NEARS LATER THIS EVENING. FORCING JUST DOWNSTREAM FROM THE S/WV HAS KICKED OFF PLENTY OF TSTMS ACROSS ERN ONTARIO AND NOW QUEBEC. PREVIOUS DISCUSSION...A SHORT WAVE TROUGH APPROACHING FROM THE WEST WILL WEAKEN THIS EVENING AS IT MOVES EASTWARD TOWARD NORTHERN NEW ENGLAND. THE ATTENDANT SFC COLD FRONT WILL APPROACH AS WELL...AND ALSO WEAKEN. A SHIELD OF LIGHT RAIN CONTINUES TO TRAVERSE ACROSS NORTHERN AND CENTRAL ZONES AS OF 19Z THIS SUNDAY AFTERNOON. THIS WILL STABILIZE THE AIRMASS ACROSS THIS AREA. HOWEVER...ALONG THE COASTAL PLAIN SWWD OVER TO SOUTHERNMOST NH SHOULD REMAIN MOSTLY DRY FOR THE NEXT SEVERAL HOURS. THEREFORE...THESE AREAS SHOULD RETAIN THE INSTABILITY /1000-1500 J/KG SBCAPE/ THROUGH EARLY EVENING. THE QUESTION IS DO THUNDERSTORMS DEVELOP IN THIS AREA. SEVERAL OF THE LATEST RUNS OF THE HRRR CONTINUE TO SHOW THUNDERSTORMS WILL HEAVY RAINFALL MOVING ACROSS SOUTHERNMOST NH AND SOUTHERNMOST ME BETWEEN 22Z AND 03Z. THIS SEEMS REASONABLE GIVEN THE CURRENT MESOSCALE SETUP. AS A RESULT WILL CONTINUE WITH HIGH POPS...ESPECIALLY IN THIS AREA. MODERATE DEEP LAYER SHEAR MAY AID IN A FEW OF THESE STORMS BECOMING STRONG...WITH GUSTY WINDS BEING THE MAIN THREAT. WITH PWATS INCREASING TO AROUND 2 INCHES BY EARLY EVENING...TORRENTIAL DOWNPOURS WILL BE LIKELY IN ANY THUNDERSTORM. THERE IS A LOW PROB FOR TRAINING STORMS ACROSS SOUTHERN NH AND SOUTHERNMOST ME...SO LOCALIZED FLASH FLOODING WILL BE POSSIBLE THIS EVENING. THE BULK OF THE ACTIVITY SHOULD MOVE OFFSHORE AROUND MIDNIGHT LEADING TO A MAINLY DRY OVERNIGHT. && .SHORT TERM /MONDAY NIGHT/... ON MONDAY...THE SHORT WAVE TROUGH WILL DEPART IN THE MORNING. STILL...WITH MODERATE AMOUNTS OF LOW LEVEL THETA-E IN TANDEM WITH SLIGHTLY COOLER TEMPS ALOFT AND A WEAK SFC FRONT IN THE VCNTY...WE COULD SEE A FEW SHOWERS DURING THE DAY...PERHAPS A THUNDERSTORM. HOWEVER...ACTIVITY SHOULD BE FEW AND FAR BETWEEN...WITH HIGHEST POPS ACROSS CENTRAL AND NORTHERN ZONES. HUMID CONDITIONS WILL CONTINUE. MUGGY AND QUIET MONDAY NIGHT. && .LONG TERM /TUESDAY THROUGH SUNDAY/... COLD FRONT APPROACHES FROM THE WEST ON TUESDAY AND WILL SET THE STAGE FOR POSSIBLE SEVERE WEATHER. PRE-FRONTAL TROUGH FORECAST TO PUSH IN FROM THE WEST DURING PRIME TIME HEATING. MODERATE CAPES AND INCREASING SHEAR DURING THE AFTERNOON AND EVENING HOURS WILL LIKELY RESULT IN MORE ORGANIZED CONVECTION DURING THE LATE AFTERNOON AND EVENING WITH DAMAGING WINDS THE MAIN THREAT. STRONGER CELLS MAY ALSO PRODUCE SOME HAIL BUT FREEZING LEVELS WILL BE QUITE HIGH SO NOT LOOKING FOR MUCH IN THE WAY OF SEVERE HAIL. WILL SEE A HOT AND MUGGY DAY WITH HIGHS RANGING THROUGH THE 80S. COLD FRONT WILL PUSH OFFSHORE TUESDAY NIGHT WITH CONVECTION ENDING ACROSS THE REGION BY MIDNIGHT. HIGH PRESSURE BUILDING IN FROM THE WEST WILL BRING CLEARING DOWNWIND OF THE MOUNTAINS. LOW TEMPS OVERNIGHT WILL RANGE THROUGH THE 60S. COOLER AND MUCH DRIER AIR PUSHES IN FOR WEDNESDAY AS HIGH PRESSURE CONTINUES TO BUILD INTO THE NORTHEAST. SHOULD SEE A MOSTLY SUNNY DAY WITH HIGHS FROM THE MID 70S TO LOWER 80S. FAIR WEATHER WILL CONTINUE THURSDAY AND FRIDAY AS HIGH PRESSURE CONTINUES TO BUILD SOUTH OF THE REGION FINALLY PUSHING OFFSHORE ON FRIDAY. AFTER A STELLAR LATE SUMMER DAY ON THURSDAY...RETURN FLOW WILL BEGIN TO PUMP WARMER AND MORE HUMID AIR BACK INTO THE REGION ON FRIDAY. MAY SEE ENOUGH INSTABILITY CREEP INTO THE CONNECTICUT VALLEY LATE FRIDAY TO KICK OFF AN ISOLATED SHOWER OR THUNDERSTORM BUT THE MAJORITY OF THE FORECAST AREA WILL SEE A DRY DAY. RATHER STRONG LOOKING COLD FRONT FORECAST TO PUSH IN FROM THE WEST ON SATURDAY WHICH COULD PRODUCE ANOTHER ROUND OF SEVERE THUNDERSTORMS. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... SHORT TERM...LOCAL IFR IN SHOWERS AND THUNDERSTORMS THIS EVENING. AFTER MIDNIGHT...FOG AND SOME LOW STRATUS MAY DEVELOP AND RESULT IN LOW CONDITIONS AS WELL. MAINLY VFR EXPECTED ON MONDAY OUTSIDE OF WDLY SCT SHOWERS. LONG TERM...MAINLY VFR EXPECTED OUTSIDE OF ANY SHOWERS AND THUNDERSTORMS TUE EVE/NIGHT. SOME VALLEY FOG AND COASTAL STRATUS POSSIBLE DURING THE PERIOD LATE AT NIGHT. && .MARINE... SHORT TERM...SCA FOR THE OUTER WATERS FOR TONIGHT. OTHERWISE...SUB-SCA CONDITIONS LIKELY THROUGH MONDAY NIGHT. LONG TERM...SUB-SCA EXPECTED TUE THROUGH FRI. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ150-152. && $$ NEAR TERM...LEGRO
AREA FORECAST DISCUSSION
NWS GRAY ME
323 PM EDT SUN AUG 31 2014 .SYNOPSIS... A COLD FRONT WILL DROP SOUTHEAST THROUGH THE REGION O0VERNIGHT AND WILL STALL OFF THE COAST ON MONDAY. A SECOND COLD FRONT WILL APPROACH FROM THE WEST ON TUESDAY AND WILL CROSS THE REGION TUESDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE WEST ON WEDNESDAY AND WILL CREST OVER THE REGION THURSDAY BEFORE SHIFTING OFFSHORE. HIGH PRESSURE WILL HOLD OFF THE NEW ENGLAND COAST ON FRIDAY. A COLD FRONT WILL CROSS THE AREA ON SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... A SHORT WAVE TROUGH APPROACHING FROM THE WEST WILL WEAKEN THIS EVENING AS IT MOVES EASTWARD TOWARD NORTHERN NEW ENGLAND. THE ATTENDANT SFC COLD FRONT WILL APPROACH AS WELL...AND ALSO WEAKEN. A SHIELD OF LIGHT RAIN CONTINUES TO TRAVERSE ACROSS NORTHERN AND CENTRAL ZONES AS OF 19Z THIS SUNDAY AFTERNOON. THIS WILL STABILIZE THE AIRMASS ACROSS THIS AREA. HOWEVER...ALONG THE COASTAL PLAIN SWWD OVER TO SOUTHERNMOST NH SHOULD REMAIN MOSTLY DRY FOR THE NEXT SEVERAL HOURS. THEREFORE...THESE AREAS SHOULD RETAIN THE INSTABILITY /1000-1500 J/KG SBCAPE/ THROUGH EARLY EVENING. THE QUESTION IS DO THUNDERSTORMS DEVELOP IN THIS AREA. SEVERAL OF THE LATEST RUNS OF THE HRRR CONTINUE TO SHOW THUNDERSTORMS WILL HEAVY RAINFALL MOVING ACROSS SOUTHERNMOST NH AND SOUTHERNMOST ME BETWEEN 22Z AND 03Z. THIS SEEMS REASONABLE GIVEN THE CURRENT MESOSCALE SETUP. AS A RESULT WILL CONTINUE WITH HIGH POPS...ESPECIALLY IN THIS AREA. MODERATE DEEP LAYER SHEAR MAY AID IN A FEW OF THESE STORMS BECOMING STRONG...WITH GUSTY WINDS BEING THE MAIN THREAT. WITH PWATS INCREASING TO AROUND 2 INCHES BY EARLY EVENING...TORRENTIAL DOWNPOURS WILL BE LIKELY IN ANY THUNDERSTORM. THERE IS A LOW PROB FOR TRAINING STORMS ACROSS SOUTHERN NH AND SOUTHERNMOST ME...SO LOCALIZED FLASH FLOODING WILL BE POSSIBLE THIS EVENING. THE BULK OF THE ACTIVITY SHOULD MOVE OFFSHORE AROUND MIDNIGHT LEADING TO A MAINLY DRY OVERNIGHT. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... ON MONDAY...THE SHORT WAVE TROUGH WILL DEPART IN THE MORNING. STILL...WITH MODERATE AMOUNTS OF LOW LEVEL THETA-E IN TANDEM WITH SLIGHTLY COOLER TEMPS ALOFT AND A WEAK SFC FRONT IN THE VCNTY...WE COULD SEE A FEW SHOWERS DURING THE DAY...PERHAPS A THUNDERSTORM. HOWEVER...ACTIVITY SHOULD BE FEW AND FAR BETWEEN...WITH HIGHEST POPS ACROSS CENTRAL AND NORTHERN ZONES. HUMID CONDITIONS WILL CONTINUE. MUGGY AND QUIET MONDAY NIGHT. && .LONG TERM /TUESDAY THROUGH SUNDAY/... COLD FRONT APPROACHES FROM THE WEST ON TUESDAY AND WILL SET THE STAGE FOR POSSIBLE SEVERE WEATHER. PRE-FRONTAL TROUGH FORECAST TO PUSH IN FROM THE WEST DURING PRIME TIME HEATING. MODERATE CAPES AND INCREASING SHEAR DURING THE AFTERNOON AND EVENING HOURS WILL LIKELY RESULT IN MORE ORGANIZED CONVECTION DURING THE LATE AFTERNOON AND EVENING WITH DAMAGING WINDS THE MAIN THREAT. STRONGER CELLS MAY ALSO PRODUCE SOME HAIL BUT FREEZING LEVELS WILL BE QUITE HIGH SO NOT LOOKING FOR MUCH IN THE WAY OF SEVERE HAIL. WILL SEE A HOT AND MUGGY DAY WITH HIGHS RANGING THROUGH THE 80S. COLD FRONT WILL PUSH OFFSHORE TUESDAY NIGHT WITH CONVECTION ENDING ACROSS THE REGION BY MIDNIGHT. HIGH PRESSURE BUILDING IN FROM THE WEST WILL BRING CLEARING DOWNWIND OF THE MOUNTAINS. LOW TEMPS OVERNIGHT WILL RANGE THROUGH THE 60S. COOLER AND MUCH DRIER AIR PUSHES IN FOR WEDNESDAY AS HIGH PRESSURE CONTINUES TO BUILD INTO THE NORTHEAST. SHOULD SEE A MOSTLY SUNNY DAY WITH HIGHS FROM THE MID 70S TO LOWER 80S. FAIR WEATHER WILL CONTINUE THURSDAY AND FRIDAY AS HIGH PRESSURE CONTINUES TO BUILD SOUTH OF THE REGION FINALLY PUSHING OFFSHORE ON FRIDAY. AFTER A STELLAR LATE SUMMER DAY ON THURSDAY...RETURN FLOW WILL BEGIN TO PUMP WARMER AND MORE HUMID AIR BACK INTO THE REGION ON FRIDAY. MAY SEE ENOUGH INSTABILITY CREEP INTO THE CONNECTICUT VALLEY LATE FRIDAY TO KICK OFF AN ISOLATED SHOWER OR THUNDERSTORM BUT THE MAJORITY OF THE FORECAST AREA WILL SEE A DRY DAY. RATHER STRONG LOOKING COLD FRONT FORECAST TO PUSH IN FROM THE WEST ON SATURDAY WHICH COULD PRODUCE ANOTHER ROUND OF SEVERE THUNDERSTORMS. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... SHORT TERM...LOCAL IFR IN SHOWERS AND THUNDERSTORMS THIS EVENING. AFTER MIDNIGHT...FOG AND SOME LOW STRATUS MAY DEVELOP AND RESULT IN LOW CONDITIONS AS WELL. MAINLY VFR EXPECTED ON MONDAY OUTSIDE OF WDLY SCT SHOWERS. LONG TERM...MAINLY VFR EXPECTED OUTSIDE OF ANY SHOWERS AND THUNDERSTORMS TUE EVE/NIGHT. SOME VALLEY FOG AND COASTAL STRATUS POSSIBLE DURING THE PERIOD LATE AT NIGHT. && .MARINE... SHORT TERM...SCA FOR THE OUTER WATERS FOR TONIGHT. OTHERWISE...SUB-SCA CONDITIONS LIKELY THROUGH MONDAY NIGHT. LONG TERM...SUB-SCA EXPECTED TUE THROUGH FRI. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ150-152. && $$ NEAR TERM...MLE
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1028 PM EDT MON SEP 1 2014 .SYNOPSIS... A BERMUDA HIGH WILL PERSIST THROUGH TUESDAY. A COLD FRONT WILL CROSS THE AREA TUESDAY NIGHT...FOLLOWED BY HIGH PRESSURE THROUGH THE REST OF THE WEEK. && .NEAR TERM /THROUGH TUESDAY/... SURFACE HIGH PRESSURE PERSISTS OFFSHORE. WATER VAPOR IMAGERY INDICATES AN UPPER DISTURBANCE MOVING ACROSS WV. SHOWER ACTIVITY HAS BECOME VERY ISOLATED. ONE SHOWER NEAR WARM SPRINGS VA MAY BRUSH THE SOUTHERN TIER OF THE FORECAST AREA IN THE NEXT COUPLE OF HOURS...AND OTHER SPOTTY AREAS OF LIGHT RAIN ARE APPROACHING THE SHENANDOAH VALLEY. HRRR HAS DEPICTED THIS PRETTY WELL...AND INDICATES SOME ADDITIONAL SHOWER ACTIVITY WILL BE POSSIBLE AS THE DISTURBANCE MOVES ACROSS THE CWA OVER THE NEXT SEVERAL HOURS. KEPT MENTION OF THUNDER ACROSS THE POTOMAC HIGHLANDS. ALTHOUGH IT SHOULD BE ISOLATED...CLOUD TOPS ON THE SHOWER NEAR WARM SPRINGS ARE AT -36C...INDICATING ENOUGH INSTABILITY FOR A FEW LIGHTNING STRIKES. WILL HAVE POTENTIAL FOR FOG TONIGHT WITH MOIST AIRMASS IN PLACE...BUT IT MAY BE INHIBITED IN SOME SPOTS WITH APPROACHING CLOUDS FROM THE DISTURBANCE TO OUR WEST. LOWS GENERALLY IN THE UPPER 60S TO LOW 70S TONIGHT...AND SLIGHTLY COOLER IN ELEVATED AREAS. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... COLD FRONT WILL STILL BE LOCATED ACROSS THE OHIO VALLEY AT 12Z TUE. BUT FRONT WILL MARCH EASTWARD THROUGH THE DAY...MAKING IT TO THE POTOMAC HIGHLANDS BY LATE AFTERNOON. PRE-FRONTAL ENVIRONMENT WILL BE WARM AND MOIST...BUT CONVECTION LIKELY WAITS UNTIL THE FRONT GETS CLOSER TO THE CWA AND HAVE POPS EXPANDING EASTWARD WITH TIME HIGHEST IN THE EVENING ACROSS THE INTERSTATE 95 CORRIDOR. THERE IS THE RISK FOR A FEW STORMS TO BECOME SEVERE /DAMAGING WIND GUSTS/ TUESDAY...ESPECIALLY BEFORE DARK DUE TO THE COMBINATION OF INSTABILITY AND INCREASED SHEAR. CONFIDENCE IS LOWER FURTHER DOWNSTREAM ONCE THE SUN SETS. FRONT MOVES THROUGH AT NIGHT. POPS LOWER FROM WEST TO EAST. DRIER AIR MOVES IN FOR WEDNESDAY WITH THE RETURN OF SUNSHINE. WHILE DEWPOINTS ARE LOWER...DOWNSLOPING WILL SUPPORT ABOVE NORMAL TEMPERATURES WHICH STILL MAY BE NEAR 90. SAME TYPE OF SCENARIO ON THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... WEAK SURFACE TROUGH...MOISTURE AND WEAK PVA MAY BE ENOUGH TO SUPPLY A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS FRIDAY. INCREASED MOISTURE AND THE PASSAGE OF COLD FRONT WILL SUPPORT DEVELOPMENT OF STRONGER ACTIVITY OVER THE WEEKEND AND INTO MONDAY. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... PRIMARILY VFR CONDITIONS EXPECTED THIS EVENING INTO THE OVERNIGHT HOURS...ALTHOUGH A BRIEF SHOWER IS POSSIBLE AT ALL TERMINALS OUTSIDE OF BWI/MTN. FOG MAY DEVELOP LATE TONIGHT WITH A MOIST AIRMASS IN PLACE. TSRA POSSIBLE AGAIN TUESDAY AFTERNOON/EVENING AHEAD OF A COLD FRONT. NO SIGNIFICANT WEATHER EXPECTED MID TO LATE WEEK. && .MARINE... EARLIER GUSTS ON THE WATERS NEAR TANGIER SOUND HAVE DIMINISHED. WINDS GENERALLY FROM THE SOUTH 10KT OR LESS TONIGHT. APPROACHING COLD FRONT WILL LIKELY PRODUCE SCATTERED THUNDERSTORMS LATE TUESDAY AFTERNOON AND EVENING...WITH GUSTY WINDS POSSIBLE. FRONT MOVES THROUGH TUESDAY NIGHT WITH HIGH PRESSURE BUILDING IN FOR WEDNESDAY. SOUTHERLY CHANNELLING/SCA CONDITIONS COULD BE POSSIBLE LATE FRIDAY. COLD FRONT EXPECTED TO MOVE THROUGH OVER THE WEEKEND. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...CEM/BPP NEAR TERM...BPP/KCS SHORT TERM...BPP LONG TERM...CEM AVIATION...CEM/BPP/KCS MARINE...CEM/BPP/KCS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
329 PM EDT SUN AUG 31 2014 .SYNOPSIS... BERMUDA HIGH PRESSURE WILL PERSIST THROUGH TUESDAY WITH AN ACTIVE PATTERN FOR THE EASTERN SEABOARD. A WEAK COLD FRONT WILL CROSS THE AREA TUESDAY NIGHT...FOLLOWED BY HIGH PRESSURE. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... AREA BETWEEN I-81 AND THE BAY HAS RECEIVED PLENTY OF INSOLATION TODAY...WHICH SUPPORTS THE DVLPMNT OF LEE TROFFING EVIDENT IN LTST SFC ANALY. OTRW...THE NEAREST SYNOP FEATURE IS A WK CDFNT IN THE ST LAWR VLY SWWD TO DTW. A BKN LINE OF SHRA/TSRA HAS DVLPD ALONG THE DIFFERENTIAL HEATING BNDRY...FM FDK-OKV-HIGHLAND CO VA. ADDTL TSRA CAN BE FOUND JUST OVER THE SUSQ RIVER IN CECIL CO. MESO ANALY SUGGESTS A RIBBON OF MUCAPE AOA 2000 J/KG AND EFFECTIVE BULK SHEAR ALONG AND JUST E OF THE AREA WHERE STORMS FORMING. THEREFORE...SEE NO REASON WHY DVLPMNT WONT CONTINUE. HRRR HAS BEEN PERFORMING RATHER WELL THUS FAR TDA. IT SUGGESTS THAT PCPN WL CONT TO FILL IN AS AREA HEADS TWD I-95 BY 20-22Z. FCST IS BASED ON THIS SCENARIO. THERES ENUF CAPE AND SHEAR FOR ORGANIZATION TO OCCUR. THUS FAR THATS FAILED TO HPPN...LKLY DUE TO WK MID LVL LAPSE RATES. IF WE CAN OVERCOME THE ISSUES IN THE MID LVLS...THEN THE MOST LKLY THREAT WUD COME FROM WET MICROBURSTS. IN ADDITION...PWAT NEAR 2 INCHES WUD SUPPORT HVY RAINERS. THE TAIL OF A PVA LOBE WL CROSS THE AREA BTWN 00-06Z. HV HELD ONTO LKLY OR HIER POPS ALL AREAS XCPT FOR CHO-EZF-NHK DUE TO THIS ADDED SUPPORT. ONCE WE GET TOO MUCH LATER THAN THAT...WE WL LOSE OUR HEATING...AND XPCT A DOWNWARD TREND TO THE STORMS. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/... WL STILL HV LEE TROF AND AN UNSTBL AMS MON. HWVR...FORCING FOR PCPN WL BE LACKING. STILL XPCT SCT STORM DVLPMNT DURING THE MIDDAY...WHICH WL BE DROPPING INTO THE LEE TROF DURING THE AFTN. THE RELATIVE LACK OF ACTIVITY AND CLEARING SKIES FROM WEST-TO- EAST WILL ALLOW TEMPS TO CLIMB BACK INTO THE U80S AND SOME L90S FOR THE AREA ON MON AFTN...W/ DEWPOINTS STANDING PAT IN THE U60S/L70S - ANOTHER MUGGY DAY FOR THE AREA. WEAK RIDGING CROSSES THE CENTRAL MID-ATLANTIC MONDAY NIGHT INTO TUESDAY...MAKING FOR A REPRIEVE IN THUNDERSTORMS FOR 12-18 HRS. WITH THE BERMUDA HIGH IN PLACE...EXPECT TUESDAY TO HAVE THE HIGHEST TEMPERATURE DAY SINCE JULY. MAX TEMPS LOW TO MID 90S ACROSS LOWER ELEVATIONS. THE NEXT COLD FRONT APPROACHES LATE TUESDAY AND CROSSES THAT NIGHT. WITH PLENTY OF ENERGY FROM THE HOT DAY...EXPECT AT LEAST ISOLATED SEVERE WEATHER...PARTICULAR FOR WRN ZONES THAT ARE PROGGED TO GET THE EVENING ACTIVITY. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... HIGH PRESSURE OVER THE CWA WILL MOVE OFFSHORE ALLOWING A COLD FRONT FROM THE WEST TO ENTER THE CWA FRIDAY. ALTHOUGH PVA IS WEAK... STALLED BOUNDARY AND MOISTURE WILL SUPPLY ACTIVE WEATHER INTO THE WEEKEND. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... VFR CONDS ACRS THE TERMINALS TAFTN. SCTD-NMRS SHRA/TSRA HV DVLPD E OF MRB BUT W OF THE REST OF THE AIRFIELDS. DUE TO XPCTD CVRG AND TRACKABLE FEATURES...TAFS NOW HV EXPLICIT THUNDER MENTION. IN ADDITION...HV TEMPO FOR MOST LKLY TIME FRAME...22Z-02Z. HV MVFR VSBY AND G30 KT. IF FULL CNVCTV DVLPMNT REALIZED AND AN AIRFIELD TAKES A DIRECT HIT...IFR FLGT CONDS AND HIER GUSTS PSBL. SLY WINDS WILL PERSIST INTO MON...ALONG W/ A FEW HIT/MISS SHOWERS AS WELL THRU MON EVE. BRIEF HIGH PRESSURE/VFR TUESDAY ON A HOT DAY (MAX TEMPS IN THE MID 90S). SCATTERED STRONG THUNDERSTORMS TUESDAY NIGHT AS A WEAK COLD FRONT CROSSES THE REGION. HIGH PRESSURE/VFR OUTSIDE OF POTENTIAL MORNING FOG MID TO LATE WEEK. && .MARINE... SLY FLOW ACRS THE MARINE AREA SUN-MON. MDL SNDGS DEPICT G20 KT PSBL TAFTN...WHICH BEING FULLY REALIZED ATTM. HV RAISED SCA INTO THE EVNG ALL WATERS. SLY FLOW PTTN CONTS INTO MON...BUT WNDS SHUD BE LIGHTER. SUB SCA SWLY FLOW MONDAY NIGHT THROUGH TUESDAY. WEAK COLD FRONT BRINGS WLY FLOW LATE TUESDAY NIGHT THROUGH WEDNESDAY. HIGH PRESSURE OVERHEAD WEDNESDAY NIGHT AND THURSDAY. && .TIDES/COASTAL FLOODING... DEPARTURES ON THE UPR TIDAL POTOMAC RIVER AND MOST OF THE BAY STILL HOVERING AROUND 1 FT. LWTV2/SLIM2 STILL ONLY 3/4 FT ABOVE NORMAL. A GOOD SLY FLOW CONTS ON THE WATERS...SO DO NOT ANTICIPATE DEPARTURES TO DECREASE MUCH TNGT. BASED ON THESE TRENDS... ANNAPOLIS WL EXCEED MINOR CRITERIA...AND SVRL OTHER SITES WL REACH CAUTION STAGE. HV ISSUED COASTAL FLOOD ADVY FOR AA COUNTY...AND MONITOR THE REST. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT EDT TONIGHT FOR MDZ014. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ANZ530>533-536>542. SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ534- 543. && $$ SYNOPSIS...BAJ NEAR TERM...HTS SHORT TERM...HTS/GMS LONG TERM...CEM AVIATION...HTS/BAJ MARINE...HTS/BAJ TIDES/COASTAL FLOODING...HTS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1018 AM EDT SUN AUG 31 2014 .SYNOPSIS... BERMUDA HIGH PRESSURE WILL PERSIST THROUGH TUESDAY WITH AN ACTIVE PATTERN FOR THE EASTERN SEABOARD. A WEAK COLD FRONT WILL CROSS THE AREA TUESDAY NIGHT...FOLLOWED BY HIGH PRESSURE. && .NEAR TERM /THROUGH TONIGHT/... HIPRES OFF THE EAST COAST OF THE CONUS THIS MRNG. THE ERN SEABOARD W/IN WARM/HUMID S/SWLY FLOW...AHD OF A CDFNT ACRS SRN CNDA. STLT/WATER VAPOR IMGRY DEPICT A STREAM OF MSTR AHD OF THE CDFNT...EMINATING FM THE GLFMEX UP ALONG THE APLCHNS TO THE UPR OHVLY/ERN GRTLKS. PWAT W/IN THIS ZONE AOA 2 INCHES. MRNG LWX RAOB DEPICTS AN INVSN ARND H9...BUT A VERY UNSTBL ENVIRONMENT ABV THAT. DAYTIME HEATING SHUD BE ABLE TO ERODE THE INVSN...BUT WL AT LEAST HOLD THINGS IN CHECK FOR A LTL WHILE. A PIECE OF ENERGY HAS BKN OFF FM MAIN STREAM...PROVIDING SHRA TO THE PTMC HIGHLANDS. RECENT HRRR RUNS SUGGEST THIS WL MAKE IT TO THE CATOCTINS BEFORE DSPTG...LKLY A RESULT OF THE INVSN. WHILE FULL SUN TEMPS IN THE MID 90S...ADVANCING CLDCVR LKLY WL KEEP MAXT LWR THAN THAT. UPDTD TEMPS TO LTST LAMP SINCE POTL CERTAINLY THERE FOR TEMPS HIER THAN MID-UPR 80S. USING A TEMP OF 90F AND DEWPTS IN THE LWR 70S...SHUD HV 2000-2500 J/KG CAPE BY LT DAY. BUT...FORCING WL COME IN THE WAY OF PVA/MID LVL 20-30 KT FLOW...AND THAT WL HOLD OFF TIL AFTR 18Z FOR THE MTNS...AND CLSR TO 00Z FOR THE CSTL PLAIN. ALSO NEED TO BE MINDFUL OF THE DIFF HTG BNDRY...WHICH CUD BE ANTHR SOURCE OF INITIATION. CERTAINLY HV THE DOWNDRAFT POTL FOR STRONG STORMS TDA...BUT DONT THINK WE/LL BE ABLE TO ACHIEVE FULL POTL. CANNOT RULE OUT LCL WET MICROBURSTS...BUT BELIEVE THEY WL BE HIT-OR-MISS IN NATURE. AMPLE MSTR WL ALSO LEAD TO HVY RAINERS...THE OTHER THREAT THIS PM. RAFL RATES WL BE SUFFICIENT TO LEAD TO A LCL FLASH FLOOD THREAT... SPCLY UNDER TRAINING CELLS. && .SHORT TERM /MONDAY THROUGH TUESDAY/... AFTER THE EVE CONVECTION HAS DISSIPATED OFF AND MOVED EAST... ANOTHER REGIONAL BATCH OF LIGHT/MOD RANGE IS TAGGED BY NEAR TERM GUIDANCE AS MOVING ALONG THE MASON-DIXON LINE AS WELL - KEEPING PRECIP CHANCES ALIVE INTO EARLY MON. AS THE BACK END OF THIS FEATURE PASSES BY TO THE NORTH...PRECIP CHANCES WILL REMAIN IN THE LOW CHANCE RANGE THRU MON AFTN/EVE ACROSS THE ERN HALF OF THE CWA BUT MAINLY OF A LIGHT/SCTD NATURE...OUTSIDE OF A FEW TSTMS. THE RELATIVE LACK OF ACTIVITY AND CLEARING SKIES FROM WEST-TO-EAST WILL ALLOW TEMPS TO CLIMB BACK INTO THE U80S AND SOME L90S FOR THE AREA ON MON AFTN...W/ DEWPOINTS STANDING PAT IN THE U60S/L70S - ANOTHER MUGGY DAY FOR THE AREA. WEAK RIDGING CROSSES THE CENTRAL MID-ATLANTIC MONDAY NIGHT INTO TUESDAY...MAKING FOR A REPRIEVE IN THUNDERSTORMS FOR 12-18 HRS. WITH THE BERMUDA HIGH IN PLACE...EXPECT TUESDAY TO HAVE THE HIGHEST TEMPERATURE DAY SINCE JULY. MAX TEMPS LOW TO MID 90S ACROSS LOWER ELEVATIONS. THE NEXT COLD FRONT APPROACHES LATE TUESDAY AND CROSSES THAT NIGHT. WITH PLENTY OF ENERGY FROM THE HOT DAY...EXPECT AT LEAST ISOLATED SEVERE WEATHER...PARTICULAR FOR WRN ZONES THAT ARE PROGGED TO GET THE EVENING ACTIVITY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE BUILDS IN BEHIND WITH CONTINENTAL AIR (NOT CANADIAN) SO TEMPERATURE REMAIN ABOVE NORMAL. EXPECT MAX TEMPS AROUND 90F WEDNESDAY THROUGH FRIDAY. RETURN FLOW AND ACTIVE WEATHER RETURNS LATE FRIDAY INTO THE WEEKEND. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... MRNG FLGT RESTRICTIONS HV CLRD ACRS THE TERMINALS. SCTD SHRA/TSRA XPCTD TO DVLP LATER TDA INTO THIS EVNG. LCL IFR PSBL. SCT NATURE OF THE THREAT LENDS TO VCTS IN TAF ATTM. MORE SPECIFIC RESTRICTIONS WL BE PLACED INTO FCST WHEN/WHERE APPROPRIATE. SLY WINDS WILL PERSIST INTO MON...ALONG W/ A FEW HIT/MISS SHOWERS AS WELL THRU MON EVE. BRIEF HIGH PRESSURE/VFR TUESDAY ON A HOT DAY (MAX TEMPS IN THE MID 90S). SCATTERED STRONG THUNDERSTORMS TUESDAY NIGHT AS A WEAK COLD FRONT CROSSES THE REGION. HIGH PRESSURE/VFR OUTSIDE OF POTENTIAL MORNING FOG MID TO LATE WEEK. && .MARINE... SLY FLOW ACRS THE MARINE AREA SUN-MON. GUSTS TAFTN WL APPROACH SCA LIMITS. AM CONSIDERING POSTING ADVY FOR THE AFTN-EVNG. FLOW PTTN CONTS INTO MON. SUB SCA SWLY FLOW MONDAY NIGHT THROUGH TUESDAY. WEAK COLD FRONT BRINGS WLY FLOW LATE TUESDAY NIGHT THROUGH WEDNESDAY. HIGH PRESSURE OVERHEAD WEDNESDAY NIGHT AND THURSDAY. && .TIDES/COASTAL FLOODING... DEPARTURES ON THE UPR TIDAL POTOMAC RIVER AND MOST OF THE BAY HOVERING AROUND 1 FT. LWTV2/SLIM2 ONLY 3/4 FT ABOVE NORMAL. BASED ON CURRENT TRENDS...THE CURRENT TIDE CYCLE WILL NOT CAUSE ISSUES...ALTHOUGH ITS MIGHTY CLOSE TO ADVY AT ANNAPOLIS. WINDS WILL REMAIN SLY THRU THE DAY. THE PM TIDE IS THE HIGHER ONE ASTRONOMICALLY...SO WL NEED TO CONSIDER ADVYS. WL CONT TO MONITOR. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...BAJ NEAR TERM...HTS SHORT TERM...GMS LONG TERM...BAJ AVIATION...HTS/GMS/BAJ MARINE...HTS/GMS/BAJ TIDES/COASTAL FLOODING...HTS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1158 PM EDT MON SEP 1 2014 .AVIATION... //DISCUSSION... WIDELY SCATTERED SHOWERS WILL FUNNEL INTO AREA OVERNIGHT AND EVENTUALLY FOCUS OVER THE SOUTHERN CWA LATE TONIGHT INTO EARLY TUESDAY AS A SECONDARY SHORTWAVE TROUGH SHIFTS THROUGH THE AREA FROM THE SOUTHERN STREAM. THIS ACTIVITY WILL BRUSH THE I 94 TERMINALS WITH SCATTERED...BUT SOMEWHAT PERSISTENT...ACTIVITY AROUND DAYBREAK. TO THE NORTH...ISOLATED SHRAS WILL REMAIN HIT/MISS INTO PARTS OF THE OVERNIGHT HOURS. SOME PATCHY FOG/STRATUS WITH IFR/MVFR CONDITIONS WILL ALSO BE POSSIBLE AS LOW LEVEL MOISTURE REMAINS ELEVATED. THAT SAID...A GENERAL INCREASE IN MID/UPPER CLOUDINESS WITH APPROACHING WAVE WILL LIMIT THIS PROCESS TO SOME EXTENT. BY MID/LATE MORNING TUESDAY...EXPECT VFR CONDITIONS AS DRIER AIR WORKS INTO THE AREA. //DTW THRESHOLD THREATS... * LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT THE TERMINAL LATE TONIGHT INTO TUESDAY MORNING. * LOW CONFIDENCE IN CEILINGS BELOW 5000 FEET LATE TONIGHT INTO EARLY TUESDAY. && .PREV DISCUSSION...ISSUED 244 PM EDT MON SEP 1 2014 SHORT TERM...THIS EVENING AND TONIGHT 18Z SPECIAL CONFIRMS THE WARMER COLUMN DEPICTED BY THE RAP AND THEN SOME. 900MB INVERSION IS QUITE A BIT MORE ROBUST THAN DEPICTED BY THE GUIDANCE AS IS THE 600MB CAP. THUS, EVEN THE MOST TAME DEPICTIONS OF CONVECTION IN THE NWP ARE LIKELY TOO AGGRESSIVE AND CONCERNS REGARDING CAPPING NOTED IN THE MORNING UPDATE ARE CONFIRMED. UPDRAFTS WILL STRUGGLE ACROSS MOST OF THE CWA WITH THE EXCEPTION OF LOCATIONS NORTH OF I-69 AND ESPECIALLY WEST OF US-23 WHERE MID-LEVEL COOLING AND FORCING WILL BE MAXIMIZED. WITH THE LINE ALREADY MARCHING TOWARD THIS AREA, EXPECT THAT THE ABUNDANCE OF MID-LEVEL DRY AIR AND UNIDIRECTIONAL FLOW ABOVE 1.5KM WILL SUPPORT BOWING SEGMENTS CARRYING A LOW-END SEVERE WIND THREAT. IN ADDITION, ISOLATED TORNADO THREAT OUTLINED IN THE EARLIER UPDATE REMAINS IN TACT. FOR REMAINING AREAS, EXPECT NOTHING MORE THAN A GUST TO 40 MPH. IN ADDITION, BACKED OFF ON POPS AS EARLIER SUSPICIONS REGARDING COVERAGE POTENTIAL STILL LOOM. A WEAK COLD FRONT WILL SAG THROUGH THE AREA TONIGHT. FRONTAL INVERSION WILL PROMOTE EXPANSION OF STRATUS LATE TONIGHT, BUT EXPECT THAT MOISTURE WILL BE TOO SHALLOW AND FORCING TOO WEAK TO SUPPORT ANY LEGITIMATE COVERAGE OR INTENSITY OF SHOWERS. WITH UPPER SUPPORT IN THE FORM OF A SHEARING SHORTWAVE NOT SCHEDULED TO ARRIVE UNTIL TUESDAY MORNING PER 12Z GUIDANCE, AND MAINLY SOUTH OF THE AREA AT THAT, NOTHING MORE THAN A CHC POP IS WARRANTED ATTM. LONG TERM...TUESDAY THROUGH NEXT MONDAY A COLD FRONT WILL BE SOUTHEAST OF THE CWA TO START OUT TUESDAY MORNING. HOWEVER A MID LEVEL SHORTWAVE RIDING NORTHEAST ALONG THE FRONT WILL BRING THE CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE AREA TUESDAY MORNING. AFTER THE SHORTWAVE TRACKS OFF TO THE NORTHEAST SIGNIFICANT DRYING WILL TAKE PLACE AS A SLUG OF 30 PERCENT RELATIVE HUMIDITY AT 700 MB ADVECTS IN FROM THE WEST...ENDING RAIN CHANCES QUICKLY EARLY TUESDAY AFTERNOON. WHILE THERE IS STILL SOME UNCERTAINTY REGARDING HOW FAR WEST THE RAIN WILL FALL GIVEN THE PUSH OF DRY AIR ADVECTING IN...THE LATEST SUITE OF MODELS HAS THE DRIER AIR PUSHING IN A BIT SOONER THAN THE 00Z RUNS. THEREFORE WILL NUDGE THE FORECAST A BIT DRIER TUESDAY AFTERNOON FROM THE PREVIOUS FORECAST. DESPITE THE PASSAGE OF A COLD FRONT THERE ISN`T A LARGE PUSH OF COLD AIR ASSOCIATED WITH IT...MEANING DAYTIME HIGHS ARE EXPECTED TO GET AROUND 80 TUESDAY AFTERNOON BEHIND THE FRONT. RIDGING WILL KEEP THE FORECAST DRY THROUGH WEDNESDAY AS REBOUNDING HEIGHTS ALLOW DAYTIME HIGHS TO GET BACK INTO THE LOWER 80S BY WEDNESDAY AFTERNOON. MOISTURE SURGE FROM THE GULF OF MEXICO COMMENCES ON THURSDAY AS A LOW CHANCE FOR CONVECTION EXISTS WITHIN THE WARM SECTOR OF A REGION-WIDE LOW PRESSURE SYSTEM. BEST CHANCE FOR THUNDERSTORMS /POSSIBLY SEVERE/ WILL BE FRIDAY AS WARM AND MOIST AIRMASS (85/70 T/TD) IS IN PLACE ALONG WITH FORECASTED CAPE OF 3000 J/KG. BULK SHEAR INCREASES TO NEAR 30 KT IN THE 1-6 KM LAYER AS WELL. THESE INGREDIENTS WILL BE IN PLACE AS A RAGGED COLD FRONT CROSSES THE STATE. THIS BRINGS A TRIPLE THREAT OF SEVERE WEATHER WITH WIND...HAIL...AND ISOLATED TORNADOES ALL POSSIBLE MARINE... SHOWERS AND THUNDERSTORMS WILL TRACK THROUGH THE CENTRAL GREAT LAKES TONIGHT AS A COLD FRONT MOVES THROUGH LAKE HURON AND LOWER MICHIGAN. SOME OF THESE STORMS MAY BE SEVERE...MAINLY ACROSS THE NORTHERN PORTION OF LAKE HURON. HIGH PRESSURE WILL BUILD INTO THE REGION BEHIND THIS FRONT ON TUESDAY...WHICH WILL REMAIN IN CONTROL OF THE WEATHER THROUGH THURSDAY...PROVIDING FAVORABLE BOATING CONDITIONS. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....DG SHORT TERM...JVC LONG TERM....KURIMSKI/MM MARINE.......KURIMSKI YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
645 PM EDT SUN AUG 31 2014 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 322 PM EDT SUN AUG 31 2014 A WEAK AREA OF HIGH PRESSURE WILL KEEP MUCH OF THE REGION DRY INTO THE EVENING. A COLD FRONT WILL APPROACH FROM THE WEST ON LABOR DAY TRIGGERING SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL RETURN FOR TUESDAY DRYING THE REGION OUT. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 322 PM EDT SUN AUG 31 2014 THE MAIN CHALLENGE IN THE SHORT TERM DEALS WITH THE POTENTIAL FOR SEVERE WEATHER ON MONDAY. OVERALL THE POTENTIAL STILL EXISTS. ONE POTENTIAL LIMITING FACTOR WILL BE WHAT IMPACTS THE DECAYING AREA OF THUNDERSTORMS WILL HAVE AS IT MOVES IN FROM THE WEST MONDAY MORNING. THE HRRR RUC SHOWS THIS SYSTEM WEAKENING WELL BEFORE IT ARRIVES IN MI...SO I AM THINKING THIS WILL HAVE A MINIMAL IMPACT ON THE POTENTIAL INSTABILITY MONDAY. THE COMBINATION OF HEATING AND MOISTURE ADVECTION SUPPORTS CAPE OVER 1500 J/KG ON MONDAY. DEEP LAYER SHEAR INCREASES TOWARD 18Z AS THE MID LEVEL WAVE CURRENTLY IN WI ARRIVES IN NW LOWER. THE LIFT ASSOCIATED WITH THIS FEATURE SHOULD TRIGGER STORMS. THE SHEAR WILL HELP TO INCREASE THE POTENTIAL FOR ORGANIZED CONVECTION AND RESULTING SEVERE WEATHER. DAMAGING WINDS AND LARGE HAIL A THREAT. SRH VALUES AROUND 200 M2/S2 DO SUPPORT A RISK FOR TORNADOES. && .LONG TERM...(WEDNESDAY THROUGH SUNDAY) ISSUED AT 322 PM EDT SUN AUG 31 2014 MEDIUM RANGE MODELS ARE IN DECENT AGREEMENT INTO NEXT WEEKEND... HOWEVER THERE ARE TIMING DIFFERENCES WITH A STRONG COLD FRONT THAT COMES THROUGH FRIDAY/FRIDAY NIGHT. LARGE HIGH PRESSURE IS EXPECTED TO BE SITTING OVER THE EAST SEABOARD BY MID WEEK. THIS WILL BRING WARMING SOUTHERLY FLOW TO THE GREAT LAKES REGION. IT CONTINUES TO LOOK LIKE THURSDAY WILL BE THE WARMEST DAY OF THE WEEK WITH 80S FOR HIGHS. THE RISK FOR SHOWERS AND STORMS WILL INCREASE ON THURSDAY WITH A COLD FRONT MOVING INTO THE WESTERN GREAT LAKES. WARM AND MOIST AIR WITH MOVE IN AHEAD OF THIS FRONT. IF A LOW LEVEL JET COMES INTO PLAY WE COULD BE LOOKING AT STRONG TO SEVERE STORMS TOWARD THE END OF THE DAY. THERE CONTINUES TO BE TIMING DIFFERENCES WITH THE FRONT...BUT THE GFS SLOWED THE FRONT DOWN...CLOSER TO THE WHAT THE ECMWF HAS SHOWN. THEREFORE BELIEVE THE FRONT WILL BE COMING THROUGH ON FRIDAY WITH ADDITIONAL CHANCES FOR SHOWERS AND STORMS. MUCH COOLER AIR FOLLOWS THIS STRONG FRONT FOR FRIDAY NIGHT AND INTO NEXT WEEKEND. H8 TEMPS DROP TO +7 TO +10C AS COMPARED TO AROUND +19C AHEAD OF THE COLD FRONT. THE WEEKEND SHOULD FEATURE HIGHS IN THE UPPER 60S TO MID 70S WITH MAINLY DRY WEATHER. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 645 PM EDT SUN AUG 31 2014 SCATTERED SHOWERS MAY AFFECT OUR SOUTHEAST TERMINALS (KLAN AND PERHAPS KBTL/KJXN) DURING THE EARLY TO MID EVENING HOURS TONIGHT BEFORE DISSIPATING. MAINLY VFR CONDITIONS ARE ANTICIPATED OVERNIGHT BUT SOME PATCHY MVFR CONDITIONS MAY DEVELOP DURING THE EARLY MORNING HOURS MONDAY DUE TO LOW CLOUDS AND/OR FOG. CONDITIONS SHOULD THEN GRADUALLY DETERIORATE TO MAINLY MVFR MONDAY MORNING DUE TO LOW CLOUDS AND PATCHY FOG. BY LATE MONDAY MORNING/EARLY AFTERNOON SSW WINDS WILL INCREASE WITH GUSTS AROUND 20 TO 25 KTS. SCATTERED THUNDERSTORMS WILL ALSO DEVELOP FROM LATE MONDAY MORNING THROUGH MONDAY AFTERNOON AS INSTABILITY INCREASES AHEAD OF AN APPROACHING COLD FRONT. SCATTERED SHOWERS AND THUNDERSTORMS WILL LINGER MONDAY EVENING. && .MARINE... ISSUED AT 322 PM EDT SUN AUG 31 2014 BEACH HAZARDS AND SCA ISSUED FOR MONDAY && .HYDROLOGY... ISSUED AT 322 PM EDT SUN AUG 31 2014 HIGH PWAT VALUES SUPPORT LOCALLY HEAVY RAIN ON MONDAY. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT FROM MONDAY MORNING THROUGH MONDAY EVENING FOR MIZ037-043-050-056-064-071. LM...SMALL CRAFT ADVISORY FROM 10 AM TO 10 PM EDT MONDAY FOR LMZ844>849. && $$ SYNOPSIS...MJS SHORT TERM...MJS LONG TERM...JK AVIATION...LAURENS HYDROLOGY...MJS MARINE...MJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
330 PM EDT SUN AUG 31 2014 LATEST UPDATE... SYNOPSIS/SHORT TERM/LONG TERM/HYDRO/MARINE .SYNOPSIS... ISSUED AT 322 PM EDT SUN AUG 31 2014 A WEAK AREA OF HIGH PRESSURE WILL KEEP MUCH OF THE REGION DRY INTO THE EVENING. A COLD FRONT WILL APPROACH FROM THE WEST ON LABOR DAY TRIGGERING SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL RETURN FOR TUESDAY DRYING THE REGION OUT. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 322 PM EDT SUN AUG 31 2014 THE MAIN CHALLENGE IN THE SHORT TERM DEALS WITH THE POTENTIAL FOR SEVERE WEATHER ON MONDAY. OVERALL THE POTENTIAL STILL EXISTS. ONE POTENTIAL LIMITING FACTOR WILL BE WHAT IMPACTS THE DECAYING AREA OF THUNDERSTORMS WILL HAVE AS IT MOVES IN FROM THE WEST MONDAY MORNING. THE HRRR RUC SHOWS THIS SYSTEM WEAKENING WELL BEFORE IT ARRIVES IN MI...SO I AM THINKING THIS WILL HAVE A MINIMAL IMPACT ON THE POTENTIAL INSTABILITY MONDAY. THE COMBINATION OF HEATING AND MOISTURE ADVECTION SUPPORTS CAPE OVER 1500 J/KG ON MONDAY. DEEP LAYER SHEAR INCREASES TOWARD 18Z AS THE MID LEVEL WAVE CURRENTLY IN WI ARRIVES IN NW LOWER. THE LIFT ASSOCIATED WITH THIS FEATURE SHOULD TRIGGER STORMS. THE SHEAR WILL HELP TO INCREASE THE POTENTIAL FOR ORGANIZED CONVECTION AND RESULTING SEVERE WEATHER. DAMAGING WINDS AND LARGE HAIL A THREAT. SRH VALUES AROUND 200 M2/S2 DO SUPPORT A RISK FOR TORNADOES. .LONG TERM...(WEDNESDAY THROUGH SUNDAY) ISSUED AT 322 PM EDT SUN AUG 31 2014 MEDIUM RANGE MODELS ARE IN DECENT AGREEMENT INTO NEXT WEEKEND... HOWEVER THERE ARE TIMING DIFFERENCES WITH A STRONG COLD FRONT THAT COMES THROUGH FRIDAY/FRIDAY NIGHT. LARGE HIGH PRESSURE IS EXPECTED TO BE SITTING OVER THE EAST SEABOARD BY MID WEEK. THIS WILL BRING WARMING SOUTHERLY FLOW TO THE GREAT LAKES REGION. IT CONTINUES TO LOOK LIKE THURSDAY WILL BE THE WARMEST DAY OF THE WEEK WITH 80S FOR HIGHS. THE RISK FOR SHOWERS AND STORMS WILL INCREASE ON THURSDAY WITH A COLD FRONT MOVING INTO THE WESTERN GREAT LAKES. WARM AND MOIST AIR WITH MOVE IN AHEAD OF THIS FRONT. IF A LOW LEVEL JET COMES INTO PLAY WE COULD BE LOOKING AT STRONG TO SEVERE STORMS TOWARD THE END OF THE DAY. THERE CONTINUES TO BE TIMING DIFFERENCES WITH THE FRONT...BUT THE GFS SLOWED THE FRONT DOWN...CLOSER TO THE WHAT THE ECMWF HAS SHOWN. THEREFORE BELIEVE THE FRONT WILL BE COMING THROUGH ON FRIDAY WITH ADDITIONAL CHANCES FOR SHOWERS AND STORMS. MUCH COOLER AIR FOLLOWS THIS STRONG FRONT FOR FRIDAY NIGHT AND INTO NEXT WEEKEND. H8 TEMPS DROP TO +7 TO +10C AS COMPARED TO AROUND +19C AHEAD OF THE COLD FRONT. THE WEEKEND SHOULD FEATURE HIGHS IN THE UPPER 60S TO MID 70S WITH MAINLY DRY WEATHER. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 134 PM EDT SUN AUG 31 2014 CEILINGS WERE TRENDING TOWARD VFR EARLY THIS AFTERNOON...HOWEVER SOME MVFR MAY HOLD ON UNTIL ABOUT 20Z. OTHERWISE THE VFR AND LIGHT WINDS WILL BE MAINTAINED INTO AND THROUGH MUCH OF THE OVERNIGHT. I HAVE INTRODUCED SOME MVFR CEILINGS RETURNING AROUND DAYBREAK MONDAY DUE TO MOIST LOW LEVELS AND DIURNAL TRENDS. THEN BY LATE MONDAY MORNING/EARLY AFTERNOON SSW WINDS WILL INCREASE WITH GUSTS AROUND 20 KNOTS. ALSO IN THIS TIME FRAME WIDELY SCATTERED THUNDERSTORMS MAY BEGIN TO DEVELOP AS INSTABILITY INCREASES AHEAD OF AN APPROACHING COLD FRONT. && .MARINE... ISSUED AT 322 PM EDT SUN AUG 31 2014 BEACH HAZARDS AND SCA ISSUED FOR MONDAY && .HYDROLOGY... ISSUED AT 322 PM EDT SUN AUG 31 2014 HIGH PWAT VALUES SUPPORT LOCALLY HEAVY RAIN ON MONDAY. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT FROM MONDAY MORNING THROUGH MONDAY EVENING FOR MIZ037-043-050-056-064-071. LM...SMALL CRAFT ADVISORY FROM 10 AM TO 10 PM EDT MONDAY FOR LMZ844>849. && $$ SYNOPSIS...MJS SHORT TERM...MJS LONG TERM...JK AVIATION...JK HYDROLOGY...MJS MARINE...MJS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
224 PM EDT SUN AUG 31 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 514 AM EDT SUN AUG 31 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A MID LEVEL RIDGE FROM THE UPPER MS VALLEY THROUGH WRN LAKE SUPERIOR BTWN A DEPARTING SHRTWV TROUGH INTO NRN LOWER MI AND AN UPSTREAM SHRTWV OVER THE WRN DAKOTAS. ISOLATED SHOWERS ASSOCIATED WITH THE COMMA HEAD OF THE MI SHRTWV WERE EXITING THE ERN CWA. HOWEVER...EXTENSIVE LOW LEVEL MOISTURE/LOW CLOUDS PERSISTED OVER MUCH OF UPPER MI...EXCEPT FROM CMX/P59 TO IWD. AT THE SFC...A RIDGE EXTENDED FROM JAMES BAY AND NRN ONTARIO INTO WRN UPPER MI AND NW WI. TODAY...AS THE 850-700 MB MOISTURE DEPARTS THIS MORNING AND DAYTIME HEATING/MIXING INCREASES...EXPECT THAT THE REMAINING CLOUDS OVER THE CNTRL AND EAST WILL THIN OUT AND GIVE WAY TO SCT CU BY AFTERNOON. WITH SUBSIDENCE LIMITING INVERSION HEIGHTS CLOSER TO 900 MB...MAX TEMPS MAINLY IN THE MID 70S ARE IN STORE WITH SOME LOWER READINGS NEAR THE GREAT LAKES WHERE E OR SSE WINDS PREVAIL. TONIGHT...AS THE DAKOTAS SHORTWAVE AND ASSOCIATED SFC TROUGH APPROACH THE REGION SRLY FLOW AND MOISTURE ADVECTION WILL INCREASE. AS PWAT VALUES CLIMB INTO THE 1.5-2.0 INCH RANGE FROM NW WI TO NEAR IWD AND LARGE SCALE LIFT INCREASES WITH UPPER LEVEL DIV 700-300 MB QVECTOR CONV AHEAD OF THE MID LEVEL TROUGH...SHRA/TSRA THAT DEVELOP OVER MN WILL SPREAD TOWARD AND INTO THE CWA...MAINLY AFT 06Z. WITH THE INITIAL PUSH OF 850-700 MB THETA-E ADVECTION SOME ISOLD SHRA/TSRA MAY ALSO SPREAD INTO N CNTRL UPPER MI DURING THE EVENING...BUT CONFIDENCE INTO CNTRL UPPER MI IS LOW WITH ONLY SLIGHT CHANCE POPS MENTIONED. THE BEST CHANCE FOR SVR STORMS IS EXPECTED TO REMAIN WEST OF THE CWA...CLOSER TO THE GREATER INSTABILITY. HOWEVER...WITH MUCAPE VALUES TO AT LEAST 1K J/KG AND FAVORABLE 0-1KM/0-6KM SHEAR TO 30/40 KNOTS...SOME STRONG STORMS WILL BE POSSIBLE WITH GUSTY WINDS AND SMALL HAIL. THE MAIN HAZARD WITH TSRA LATE TONIGHT WILL BE LOCALLY HEAVY RAIN WITH SOME ISOLD 1-2 INCH AMOUNTS POSSIBLE. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 224 PM EDT SUN AUG 31 2014 ASIDE FROM SOME MINOR PRECIP AMOUNTS POSSIBLE EARLY IN THE NIGHT OVER FAR ERN UPPER MI DUE TO THE MON COLD FRONT EXITING THE AREA...MON NIGHT AND TUE LOOK DRY FOR THE MOST PART AS SFC RIDGING MOVES IN. A COUPLE MODELS SHOW A FEW HUNDREDTHS OF AN INCH OF QPF TUE AFTERNOON AS A SHORTWAVE MOVES THROUGH THE REGION...BUT FORECAST SOUNDINGS ARE JUST TOO DRY AND THE SHORTWAVE LOOKS TO GO TOO FAR SE OF THE AREA TO HAVE PRECIP IN THE FORECAST. WILL KEEP A DRY FORECAST. HIGH TEMPS LOOK TO BE FROM THE UPPER 60S TO MID 70S AS 850MB TEMPS WILL BE 9-11C. FOR WED...SFC RIDGING MOVES E...SO SLY LOW LEVEL FLOW WILL BE ON THE INCREASE UNDER ZONAL UPPER FLOW. MODELS SHOW VERY SUBTLE SHORTWAVE ENERGY MOVING THROUGH THE AREA WED. OF COURSE...THIS FAR OUT THE CONFIDENCE OF PRECIP RESULTING FROM WEAK SHORTWAVES IS MINIMAL...SO WILL HAVE SLIGHT CHANCE POPS AT BEST. FOR WED NIGHT THROUGH FRI NIGHT...MODELS TEND TO GENERALLY AGREE THAT A STRONGER SHORTWAVE WILL MOVE INTO THE NCENTRAL CONUS AND EVENTUALLY ACROSS OR NEAR THE CWA LATE FRI INTO FRI NIGHT. WHILE THE ECMWF HAS SHOWN BETTER RUN TO RUN CONTINUITY WITH THE SHORTWAVE AND RESULTING SFC LOW...THE UPPER LEVEL ENERGY IS CURRENTLY OVER THE SEWARD PENINSULA OF ALASKA AND WILL ONLY ENTER THE CONUS OVER WA TUE NIGHT. SHORTWAVE ENERGY THAT HAS YET TO REALLY DETACH FROM THE PARENT UPPER LEVEL LOW OVER ALASKA NORMALLY LEADS TO PRETTY LOW CONFIDENCE IN TIMING/TRACK 4-5 DAYS OUT...WHICH IS THE CASE HERE. DO HAVE TO PREFER THE ECMWF SINCE IT HAS BEEN MORE STEADY FROM RUN TO RUN...BUT CONFIDENCE IS STILL LOW SINCE THE GFS IS AROUND 18 HOURS SLOWER AND FARTHER S WITH THE PASSAGE OF THE RESULTING SFC LOW THAN THE ECMWF. OVERALL CONFIDENCE IN RAIN SOMEWHERE IN THE THU-FRI TIME SPAN IS GOOD ENOUGH FOR HIGH CHANCE POPS...BUT TIMING WILL NEED TO BE REFINED OVER THE NEXT FEW FORECASTS. AT THIS TIME...THE BEST CHANCES FOR STRONG TO SEVERE STORMS /USING THE PREFERRED TIMING AND TRACK OF THE ECMWF/ IS WED NIGHT INTO THU MORNING ALONG THE WARM FRONT WHERE ELEVATED STORMS WOULD BE POSSIBLE...AND AGAIN LATE THU INTO THU NIGHT AS MLCAPES APPROACH 3000J/KG WITH 0-6KM SHEAR OF 40-50KTS AND 0-1KM SHEAR AROUND 30KTS ALONG AND AHEAD OF THE COLD FRONT. WHILE ALL MODES OF SEVERE WEATHER WOULD BE POSSIBLE WITH THE ECMWF SOLUTION LATE THU INTO THU NIGHT...IT IS ALSO THE WORST CASE SCENARIO. THE FARTHER S GFS WOULD RESULT IN MORE CLOUDS ON FRI BEFORE THE SFC LOW AND COLD FRONT MOVE THROUGH...SO INSTABILITY WOULD NOT BE AS STRONG. WILL NEED TO MONITOR AS CONFIDENCE IN SEVERE CHANCE ARE LIMITED AND MODEL GUIDANCE WILL LIKELY CHANGE. FARTHER N ECMWF IS ALSO WARMEST WITH 850MB TEMPS RISING TO AROUND 20C THU AFTERNOON...WHICH WOULD RESULT IN HIGH TEMPS WELL INTO THE 80S OR EVEN LOW 90S DEPENDING ON CLOUD AND PRECIP COVERAGE. WILL GO WITH A MORE CONSENSUS APPROACH TO TEMPS GIVEN UNCERTAINTY. NEXT WEEKEND LOOKS DRY AS COOLER HIGH PRESSURE SETTLES IN BEHIND THE PREVIOUS SYSTEM. 850MB TEMPS FALL TO 3-4C ON SAT AND WARM TO 6-8C ON SUN...SO COOLER CONDITIONS WITH HIGHS IN THE 60S TO LOW 70S ARE EXPECTED. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1206 PM EDT SUN AUG 31 2014 EXPECT LINGERING SC IFR CIGS AT CMX AND SAW TO DISSIPATE WITH MIXING EARLY THIS AFTERNOON. OTHERWISE...VFR CONDITIONS WILL CONTINUE UNTIL LATE TONIGHT INTO MON MORNING AS NEXT SYSTEM AND RAIN ARRIVES BY THEN FOR IWD AND CMX. SAW IS A DIFFERENT STORY AS THERE IS A POTENTIAL OF AN UPSLOPE LOW CLOUD/FOG EVENT FROM LAKE MICHIGAN WITH SOUTH WINDS AND PUT THAT SCENARIO OF LIFR/IFR CONDITIONS WITH FOG AND LOW CLOUDS THERE TONIGHT. ON MON MORNING...RAIN WILL HAVE STARTED AND IFR/LIFR CONDITIONS FOR ALL SITES WILL PREVAIL. LLJ SETS UP TONIGHT OFF THE SFC AT ALL SITES AND PUT IN LLWS TO COVER IT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 514 AM EDT SUN AUG 31 2014 WINDS WILL BE LESS THAN 20 KTS OR LESS THROUGH MOST OF THE PERIOD EXCEPT FOR A PERIOD OF SE TO S GUSTS OF 20 TO 30 KNOTS TONIGHT AND MONDAY MORNING. WINDS WILL THEN VEER WRLY TO 20 KNOTS MON AFTERNOON AND MON NIGHT IN THE WAKE OF A LOW PRESSURE SYSTEM AND COLD FRONT. WIDESPREAD FOG WILL CONTINUE THROUGH THIS MORNING AND THEN DEVELOP AGAIN TONIGHT INTO MONDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...TITUS AVIATION...07 MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1207 PM EDT SUN AUG 31 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 514 AM EDT SUN AUG 31 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A MID LEVEL RIDGE FROM THE UPPER MS VALLEY THROUGH WRN LAKE SUPERIOR BTWN A DEPARTING SHRTWV TROUGH INTO NRN LOWER MI AND AN UPSTREAM SHRTWV OVER THE WRN DAKOTAS. ISOLATED SHOWERS ASSOCIATED WITH THE COMMA HEAD OF THE MI SHRTWV WERE EXITING THE ERN CWA. HOWEVER...EXTENSIVE LOW LEVEL MOISTURE/LOW CLOUDS PERSISTED OVER MUCH OF UPPER MI...EXCEPT FROM CMX/P59 TO IWD. AT THE SFC...A RIDGE EXTENDED FROM JAMES BAY AND NRN ONTARIO INTO WRN UPPER MI AND NW WI. TODAY...AS THE 850-700 MB MOISTURE DEPARTS THIS MORNING AND DAYTIME HEATING/MIXING INCREASES...EXPECT THAT THE REMAINING CLOUDS OVER THE CNTRL AND EAST WILL THIN OUT AND GIVE WAY TO SCT CU BY AFTERNOON. WITH SUBSIDENCE LIMITING INVERSION HEIGHTS CLOSER TO 900 MB...MAX TEMPS MAINLY IN THE MID 70S ARE IN STORE WITH SOME LOWER READINGS NEAR THE GREAT LAKES WHERE E OR SSE WINDS PREVAIL. TONIGHT...AS THE DAKOTAS SHORTWAVE AND ASSOCIATED SFC TROUGH APPROACH THE REGION SRLY FLOW AND MOISTURE ADVECTION WILL INCREASE. AS PWAT VALUES CLIMB INTO THE 1.5-2.0 INCH RANGE FROM NW WI TO NEAR IWD AND LARGE SCALE LIFT INCREASES WITH UPPER LEVEL DIV 700-300 MB QVECTOR CONV AHEAD OF THE MID LEVEL TROUGH...SHRA/TSRA THAT DEVELOP OVER MN WILL SPREAD TOWARD AND INTO THE CWA...MAINLY AFT 06Z. WITH THE INITIAL PUSH OF 850-700 MB THETA-E ADVECTION SOME ISOLD SHRA/TSRA MAY ALSO SPREAD INTO N CNTRL UPPER MI DURING THE EVENING...BUT CONFIDENCE INTO CNTRL UPPER MI IS LOW WITH ONLY SLIGHT CHANCE POPS MENTIONED. THE BEST CHANCE FOR SVR STORMS IS EXPECTED TO REMAIN WEST OF THE CWA...CLOSER TO THE GREATER INSTABILITY. HOWEVER...WITH MUCAPE VALUES TO AT LEAST 1K J/KG AND FAVORABLE 0-1KM/0-6KM SHEAR TO 30/40 KNOTS...SOME STRONG STORMS WILL BE POSSIBLE WITH GUSTY WINDS AND SMALL HAIL. THE MAIN HAZARD WITH TSRA LATE TONIGHT WILL BE LOCALLY HEAVY RAIN WITH SOME ISOLD 1-2 INCH AMOUNTS POSSIBLE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 433 AM EDT SUN AUG 31 2014 UPPER LEVELS FEATURE TROUGHING OVER THE CENTRAL CONUS TO BEGIN THE PERIOD BUT THAT GIVES WAY TO SHALLOW RIDGING BY MID WEEK. SHORTWAVE TROUGH MOVES FROM ROCKIES TO CENTRAL CANADA BY LATE THIS WEEK...WITH WARM SW FLOW ALOFT STREAMING ACROSS THE GREAT LAKES. COLD FRONT MOVES THROUGH AROUND FRIDAY WITH SFC RIDGE AND DRY/COOLER AIR SETTLING OVER UPPER GREAT LAKES BY NEXT WEEKEND. CHANCES FOR SHRA/TSRA ON LABOR DAY AS STRONG SHORTWAVE AND COLD FRONT CROSS UPPER GREAT LAKES. THERE WILL BE ADDITIONAL CHANCES FOR SHRA AND TSRA AHEAD AND ALONG THE LATE WEEK COLD FRONT AS WELL. EXPECT TEMPS FOR THE MOST PART TO BE ABOVE NORMAL THROUGH THE WEEK. TEMPS PROBABLY WILL NOT FALL BLO NORMAL UNTIL NEXT WEEKEND IN WAKE OF THE COLD FRONT PASSAGE ON FRIDAY. THUNDER CHANCES AND STRENGTH ON LABOR DAY AND AGAIN WEDNESDAY NIGHT THROUGH FRIDAY LOOKS TO BE THE HIGHEST IMPACT WEATHER THIS WEEK. LABOR DAY...INITIAL SHORTWAVE CURRENTLY DRIVING SHRA/TSRA OVER THE DAKOTAS LIFTS OVER ONTARIO TO START THE DAY WHILE ANOTHER SHORTWAVE CURRENTLY OVER OREGON/IDAHO TRACKS TOWARD WESTERN GREAT LAKES. MAIN SFC LOW WILL BE NORTH OF LK SUPERIOR CLOSER TO LEADING SHORTWAVE. SFC TROUGH WILL EXTEND SOUTH ACROSS UPPER GREAT LAKES REGION AND ON INTO THE SOUTHERN PLAINS. H85-H5 Q-VECTOR CONVERGENCE MOSTLY IMPACTS CWA IN THE MORNING. MOISTURE TRANSPORT AT H85-H7 IS MAXIMIZED AHEAD OF THE FRONT IN THE MORNING AS WELL. THERE WILL BE SOME RISK FOR STRONGER STORMS AS DURING THIS PERIOD OF FORCING/LIFT THERE IS A H85 JET UP TO 50 KTS FM THE SOUTHWEST/0-6KM SHEAR OVER 40 KTS AND 1-6KM MUCAPES UP TO 500 J/KG. FREEZING LEVEL IS BTWN 12-13KFT WITH STORM CORES HAVING TO REACH ABOVE 35 KFT FOR POTENTIAL OF ONE-INCH HAIL. INSTABILITY WILL BE LIMITING FACTOR...BUT THERE MAY BE AT LEAST ISOLATED STRONGER STORMS. BY AFTN...MLCAPES SPIKE UP WELL OVER 1000 J/KG ESPECIALLY CNTRL CWA...BUT SFC FRONT IS ON ITS WAY ACROSS CWA BY THAT TIME AND LARGER SCALE SUBSIDENCE SHOULD BE DEVELOPING IN WAKE OF SHORTWAVES MOVING THROUGH LATE TONIGHT INTO MONDAY MORNING. IF SFC FRONT SLOWS UP...EVEN JUST SLIGHTLY...ISOLD STORMS MAY TRY TO DEVELOP WITH THE INCREASING DAYTIME HEATING/INSTABILITY. RISK OF SEVERE STILL THERE AS WELL WITH 0-6KM SHEAR 35-40 KTS. MAX TEMPS ON LABOR DAY HIGHLY DEPEND ON EXTENT OF CLOUD COVER...BUT SEEMS THAT MANY AREAS WILL SEE READINGS WELL INTO THE 70S. SOUTH WINDS MAY BE GUSTY OVER EASTERN THIRD OF CWA...ESPECIALLY NEAR LK MICHIGAN SHORE. FRONT CLEARS EASTERN CWA BY MONDAY EVENING WITH HIGH PRESSURE SETTLING ACROSS FOR LATER MONDAY NIGHT INTO TUESDAY. ONSHORE WNW WINDS WILL KEEP LK SUPERIOR SHORE COOLER ON TUESDAY IN THE MID-UPR 60S...BUT TEMPS SHOULD MAINLY BE IN THE LOWER 70S ELSEWHERE. AS FLOW ALOFT BECOMES MORE ZONAL BY WEDNESDAY MAY START TO SEE WEAKER SHORTWAVES WORK ACROSS UPR LAKES. GFS/GEM-NH AGGRESSIVE WITH QPF ON WEDNESDAY BUT GFS SOUNDINGS INDICATE DEEPER MOISTURE IS LACKING WITH ONLY WEAKER SHORTWAVES SHOWN. PREFER SLOWER ECMWF SOLUTION SHOWING BETTER CHANCES OF SHRA/TSRA ARRIVING BY WEDNESDAY NIGHT AS STRONGER SHORTWAVE ARRIVES. LAST FEW RUNS OF ECMWF ARE SHOWING GREATER SIGNAL OF THIS OCCURRING. STRONG LOW-LEVEL MOISTURE TRANSPORT AIMED INTO THE UPR LAKES ALONG WITH LARGE AREA OF ML MUCAPES OVER 1000-1500 J/KG UPSTREAM WITH LIFT ENHANCED BY RIGHT ENTRANCE REGION OF JET STREAK OVER ONTARIO/QUEBEC COULD RESULT IN AT LEAST ISOLD STRONG ELEVATED STORMS WEDNESDAY NIGHT INTO THURSDAY MORNING WITH ANOTHER ROUND OF STRONGER SFC BASED STORMS ALONG FRONTAL BOUNDARY POSSIBLE LATER THURSDAY. LIMITING FACTOR FOR ADDITIONAL STORMS LATER IN THE DAY WOULD BE NOT AS MUCH MOISTURE ALONG THE SFC FRONT IN WAKE OF THE SHORTWAVE THAT MOVES THROUGH THURSDAY MORNING. TEMPS AHEAD OF THE FRONT ON THURSDAY COULD GET QUITE WARM AS H85 TEMPS SURGE TOWARD +20C. WITH FULL SUNSHINE THIS WOULD SUPPORT HIGHS INTO THE UPPER 80S IF NOT LOWER 90S. CURRENT FORECAST IS MORE TOWARD CONSENSUS WITH UNCERTAINTY ON CLOUDS AND PRECIP CHANCES. WILL BE SOMETHING THAT MAY NEED ADJUSTING IN LATER FORECASTS THOUGH. THE FRONT...ALONG WITH SOME POTENTIAL FOR ADDITIONAL SHRA/TSRA... SLIDES EAST AND SOUTH OF MOST CWA BY FRIDAY. HIGH PRESSURE MOVES ACROSS FOR AT LEAST THE START OF NEXT WEEKEND WITH A MODEST COOLING TREND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1206 PM EDT SUN AUG 31 2014 EXPECT LINGERING SC IFR CIGS AT CMX AND SAW TO DISSIPATE WITH MIXING EARLY THIS AFTERNOON. OTHERWISE...VFR CONDITIONS WILL CONTINUE UNTIL LATE TONIGHT INTO MON MORNING AS NEXT SYSTEM AND RAIN ARRIVES BY THEN FOR IWD AND CMX. SAW IS A DIFFERENT STORY AS THERE IS A POTENTIAL OF AN UPSLOPE LOW CLOUD/FOG EVENT FROM LAKE MICHIGAN WITH SOUTH WINDS AND PUT THAT SCENARIO OF LIFR/IFR CONDITIONS WITH FOG AND LOW CLOUDS THERE TONIGHT. ON MON MORNING...RAIN WILL HAVE STARTED AND IFR/LIFR CONDITIONS FOR ALL SITES WILL PREVAIL. LLJ SETS UP TONIGHT OFF THE SFC AT ALL SITES AND PUT IN LLWS TO COVER IT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 514 AM EDT SUN AUG 31 2014 WINDS WILL BE LESS THAN 20 KTS OR LESS THROUGH MOST OF THE PERIOD EXCEPT FOR A PERIOD OF SE TO S GUSTS OF 20 TO 30 KNOTS TONIGHT AND MONDAY MORNING. WINDS WILL THEN VEER WRLY TO 20 KNOTS MON AFTERNOON AND MON NIGHT IN THE WAKE OF A LOW PRESSURE SYSTEM AND COLD FRONT. WIDESPREAD FOG WILL CONTINUE THROUGH THIS MORNING AND THEN DEVELOP AGAIN TONIGHT INTO MONDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...07 MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
516 AM EDT SUN AUG 31 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 514 AM EDT SUN AUG 31 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A MID LEVEL RIDGE FROM THE UPPER MS VALLEY THROUGH WRN LAKE SUPERIOR BTWN A DEPARTING SHRTWV TROUGH INTO NRN LOWER MI AND AN UPSTREAM SHRTWV OVER THE WRN DAKOTAS. ISOLATED SHOWERS ASSOCIATED WITH THE COMMA HEAD OF THE MI SHRTWV WERE EXITING THE ERN CWA. HOWEVER...EXTENSIVE LOW LEVEL MOISTURE/LOW CLOUDS PERSISTED OVER MUCH OF UPPER MI...EXCEPT FROM CMX/P59 TO IWD. AT THE SFC...A RIDGE EXTENDED FROM JAMES BAY AND NRN ONTARIO INTO WRN UPPER MI AND NW WI. TODAY...AS THE 850-700 MB MOISTURE DEPARTS THIS MORNING AND DAYTIME HEATING/MIXING INCREASES...EXPECT THAT THE REMAINING CLOUDS OVER THE CNTRL AND EAST WILL THIN OUT AND GIVE WAY TO SCT CU BY AFTERNOON. WITH SUBSIDENCE LIMITING INVERSION HEIGHTS CLOSER TO 900 MB...MAX TEMPS MAINLY IN THE MID 70S ARE IN STORE WITH SOME LOWER READINGS NEAR THE GREAT LAKES WHERE E OR SSE WINDS PREVAIL. TONIGHT...AS THE DAKOTAS SHORTWAVE AND ASSOCIATED SFC TROUGH APPROACH THE REGION SRLY FLOW AND MOISTURE ADVECTION WILL INCREASE. AS PWAT VALUES CLIMB INTO THE 1.5-2.0 INCH RANGE FROM NW WI TO NEAR IWD AND LARGE SCALE LIFT INCREASES WITH UPPER LEVEL DIV 700-300 MB QVECTOR CONV AHEAD OF THE MID LEVEL TROUGH...SHRA/TSRA THAT DEVELOP OVER MN WILL SPREAD TOWARD AND INTO THE CWA...MAINLY AFT 06Z. WITH THE INITIAL PUSH OF 850-700 MB THETA-E ADVECTION SOME ISOLD SHRA/TSRA MAY ALSO SPREAD INTO N CNTRL UPPER MI DURING THE EVENING...BUT CONFIDENCE INTO CNTRL UPPER MI IS LOW WITH ONLY SLIGHT CHANCE POPS MENTIONED. THE BEST CHANCE FOR SVR STORMS IS EXPECTED TO REMAIN WEST OF THE CWA...CLOSER TO THE GREATER INSTABILITY. HOWEVER...WITH MUCAPE VALUES TO AT LEAST 1K J/KG AND FAVORABLE 0-1KM/0-6KM SHEAR TO 30/40 KNOTS...SOME STRONG STORMS WILL BE POSSIBLE WITH GUSTY WINDS AND SMALL HAIL. THE MAIN HAZARD WITH TSRA LATE TONIGHT WILL BE LOCALLY HEAVY RAIN WITH SOME ISOLD 1-2 INCH AMOUNTS POSSIBLE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 433 AM EDT SUN AUG 31 2014 UPPER LEVELS FEATURE TROUGHING OVER THE CENTRAL CONUS TO BEGIN THE PERIOD BUT THAT GIVES WAY TO SHALLOW RIDGING BY MID WEEK. SHORTWAVE TROUGH MOVES FROM ROCKIES TO CENTRAL CANADA BY LATE THIS WEEK...WITH WARM SW FLOW ALOFT STREAMING ACROSS THE GREAT LAKES. COLD FRONT MOVES THROUGH AROUND FRIDAY WITH SFC RIDGE AND DRY/COOLER AIR SETTLING OVER UPPER GREAT LAKES BY NEXT WEEKEND. CHANCES FOR SHRA/TSRA ON LABOR DAY AS STRONG SHORTWAVE AND COLD FRONT CROSS UPPER GREAT LAKES. THERE WILL BE ADDITIONAL CHANCES FOR SHRA AND TSRA AHEAD AND ALONG THE LATE WEEK COLD FRONT AS WELL. EXPECT TEMPS FOR THE MOST PART TO BE ABOVE NORMAL THROUGH THE WEEK. TEMPS PROBABLY WILL NOT FALL BLO NORMAL UNTIL NEXT WEEKEND IN WAKE OF THE COLD FRONT PASSAGE ON FRIDAY. THUNDER CHANCES AND STRENGTH ON LABOR DAY AND AGAIN WEDNESDAY NIGHT THROUGH FRIDAY LOOKS TO BE THE HIGHEST IMPACT WEATHER THIS WEEK. LABOR DAY...INITIAL SHORTWAVE CURRENTLY DRIVING SHRA/TSRA OVER THE DAKOTAS LIFTS OVER ONTARIO TO START THE DAY WHILE ANOTHER SHORTWAVE CURRENTLY OVER OREGON/IDAHO TRACKS TOWARD WESTERN GREAT LAKES. MAIN SFC LOW WILL BE NORTH OF LK SUPERIOR CLOSER TO LEADING SHORTWAVE. SFC TROUGH WILL EXTEND SOUTH ACROSS UPPER GREAT LAKES REGION AND ON INTO THE SOUTHERN PLAINS. H85-H5 Q-VECTOR CONVERGENCE MOSTLY IMPACTS CWA IN THE MORNING. MOISTURE TRANSPORT AT H85-H7 IS MAXIMIZED AHEAD OF THE FRONT IN THE MORNING AS WELL. THERE WILL BE SOME RISK FOR STRONGER STORMS AS DURING THIS PERIOD OF FORCING/LIFT THERE IS A H85 JET UP TO 50 KTS FM THE SOUTHWEST/0-6KM SHEAR OVER 40 KTS AND 1-6KM MUCAPES UP TO 500 J/KG. FREEZING LEVEL IS BTWN 12-13KFT WITH STORM CORES HAVING TO REACH ABOVE 35 KFT FOR POTENTIAL OF ONE-INCH HAIL. INSTABILITY WILL BE LIMITING FACTOR...BUT THERE MAY BE AT LEAST ISOLATED STRONGER STORMS. BY AFTN...MLCAPES SPIKE UP WELL OVER 1000 J/KG ESPECIALLY CNTRL CWA...BUT SFC FRONT IS ON ITS WAY ACROSS CWA BY THAT TIME AND LARGER SCALE SUBSIDENCE SHOULD BE DEVELOPING IN WAKE OF SHORTWAVES MOVING THROUGH LATE TONIGHT INTO MONDAY MORNING. IF SFC FRONT SLOWS UP...EVEN JUST SLIGHTLY...ISOLD STORMS MAY TRY TO DEVELOP WITH THE INCREASING DAYTIME HEATING/INSTABILITY. RISK OF SEVERE STILL THERE AS WELL WITH 0-6KM SHEAR 35-40 KTS. MAX TEMPS ON LABOR DAY HIGHLY DEPEND ON EXTENT OF CLOUD COVER...BUT SEEMS THAT MANY AREAS WILL SEE READINGS WELL INTO THE 70S. SOUTH WINDS MAY BE GUSTY OVER EASTERN THIRD OF CWA...ESPECIALLY NEAR LK MICHIGAN SHORE. FRONT CLEARS EASTERN CWA BY MONDAY EVENING WITH HIGH PRESSURE SETTLING ACROSS FOR LATER MONDAY NIGHT INTO TUESDAY. ONSHORE WNW WINDS WILL KEEP LK SUPERIOR SHORE COOLER ON TUESDAY IN THE MID-UPR 60S...BUT TEMPS SHOULD MAINLY BE IN THE LOWER 70S ELSEWHERE. AS FLOW ALOFT BECOMES MORE ZONAL BY WEDNESDAY MAY START TO SEE WEAKER SHORTWAVES WORK ACROSS UPR LAKES. GFS/GEM-NH AGGRESSIVE WITH QPF ON WEDNESDAY BUT GFS SOUNDINGS INDICATE DEEPER MOISTURE IS LACKING WITH ONLY WEAKER SHORTWAVES SHOWN. PREFER SLOWER ECMWF SOLUTION SHOWING BETTER CHANCES OF SHRA/TSRA ARRIVING BY WEDNESDAY NIGHT AS STRONGER SHORTWAVE ARRIVES. LAST FEW RUNS OF ECMWF ARE SHOWING GREATER SIGNAL OF THIS OCCURRING. STRONG LOW-LEVEL MOISTURE TRANSPORT AIMED INTO THE UPR LAKES ALONG WITH LARGE AREA OF ML MUCAPES OVER 1000-1500 J/KG UPSTREAM WITH LIFT ENHANCED BY RIGHT ENTRANCE REGION OF JET STREAK OVER ONTARIO/QUEBEC COULD RESULT IN AT LEAST ISOLD STRONG ELEVATED STORMS WEDNESDAY NIGHT INTO THURSDAY MORNING WITH ANOTHER ROUND OF STRONGER SFC BASED STORMS ALONG FRONTAL BOUNDARY POSSIBLE LATER THURSDAY. LIMITING FACTOR FOR ADDITIONAL STORMS LATER IN THE DAY WOULD BE NOT AS MUCH MOISTURE ALONG THE SFC FRONT IN WAKE OF THE SHORTWAVE THAT MOVES THROUGH THURSDAY MORNING. TEMPS AHEAD OF THE FRONT ON THURSDAY COULD GET QUITE WARM AS H85 TEMPS SURGE TOWARD +20C. WITH FULL SUNSHINE THIS WOULD SUPPORT HIGHS INTO THE UPPER 80S IF NOT LOWER 90S. CURRENT FORECAST IS MORE TOWARD CONSENSUS WITH UNCERTAINTY ON CLOUDS AND PRECIP CHANCES. WILL BE SOMETHING THAT MAY NEED ADJUSTING IN LATER FORECASTS THOUGH. THE FRONT...ALONG WITH SOME POTENTIAL FOR ADDITIONAL SHRA/TSRA... SLIDES EAST AND SOUTH OF MOST CWA BY FRIDAY. HIGH PRESSURE MOVES ACROSS FOR AT LEAST THE START OF NEXT WEEKEND WITH A MODEST COOLING TREND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 126 AM EDT SUN AUG 31 2014 EXPECT LINGERING VFR SC CIGS AT IWD AND CMX TO DISSIPATE AS HI PRES BLDS OVER WRN UPR MI UNDER SUBSIDENCE IN THE WAKE OF DEPARTING UPR DISTURBANCE. WITH LGT WINDS UNDER THE BLDG HI...EXPECT RADIATION FOG TO DVLP AND DROP CONDITIONS TO LIFR AND EVEN VLIFR IN THE PRESENCE OF NOCTURNAL COOLING/LINGERING HI SFC DEWPTS. A MORE STEADY... UPSLOPE N WIND OFF LK SUP WL MAINTAIN IFR CONDITIONS AT SAW. THE PRESENCE OF THESE CLDS WL LIMIT THE POTENTIAL FOR THICKER RADIATION FOG AT SAW. WITH DAYTIME HEATING...EXPECT LINGERING FOG/LO CLDS TO MIX OUT AND GIVE WAY TO VFR CONDITIONS. THIS PROCESS WL BE SLOWEST AT SAW AS AN UPSLOPE NE VEERING SE WIND DVLPS ON THE WRN FLANK OF SFC HI SHIFTING TO THE E. A STRENGTHENING SSW WIND WL OVERSPREAD THE UPR LKS THIS EVNG BTWN THE DEPARTING SFC HI AND AN APRCHG COLD FNT. WITH NOCTURNAL COOLING...A LLJ WL DVLP AND MAY BE SUFFICIENTLY STRONG TO BRING MARGINAL LLWS TO AT LEAST THE WRN IWD/CMX TAF SITES. RIGHT NOW...IT APPEARS THE INCOMING AIRMASS WL BE TOO DRY TO CAUSE ANY LO CLDS. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 514 AM EDT SUN AUG 31 2014 WINDS WILL BE LESS THAN 20 KTS OR LESS THROUGH MOST OF THE PERIOD EXCEPT FOR A PERIOD OF SE TO S GUSTS OF 20 TO 30 KNOTS TONIGHT AND MONDAY MORNING. WINDS WILL THEN VEER WRLY TO 20 KNOTS MON AFTERNOON AND MON NIGHT IN THE WAKE OF A LOW PRESSURE SYSTEM AND COLD FRONT. WIDESPREAD FOG WILL CONTINUE THROUGH THIS MORNING AND THEN DEVELOP AGAIN TONIGHT INTO MONDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...KC MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1207 PM CDT SUN AUG 31 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 245 AM CDT SUN AUG 31 2014 ALTHOUGH SUNDAY AND ITS POTENTIAL SEVERE WEATHER EVENT ARE HERE...THE CAMS STILL LEAVE PLENTY OF QUESTIONS AS TO HOW THINGS WILL EVOLVE LATER TODAY. FOR THIS MORNING...INITIAL SURGE OF THE LLJ IS MOVING ACROSS THE DAKOTAS OUT AHEAD OF SHORTWAVE THAT CAN BE SEEN ON WATER VAPOR MOVING INTO CENTRAL SODAK. ALTHOUGH BEST FORCING AND MOST WIDESPREAD THUNDERSTORM ACTIVITY CAN BE FOUND AT THE NOSE OF THE LLJ ACROSS NODAK AND ON ITS WAY TO NW MN...ENOUGH THETA-E ADVECTION AND ISENTROPIC LIFT IS PRESENT ON THE ERN FLANK OF THE LLJ TO GET SCT CONVECTION DOWN INTO NE NEB. THE HRRR/HOPWRF/MPXWRF/NMM/ARW ALL SHOW THIS BAND OF ISO/SCT SHOWERS WORKING ACROSS MN THROUGH THE MORNING...SO WORKED SOME 20/30 POPS ACROSS MN THIS MORNING TO ACCOUNT FOR THAT. EXPECT THIS ACTIVITY TO START WEAKENING AS IT MOVES EAST ACROSS MN AND LIKELY WILL NOT MAKE IT INTO WI AS IT ENCOUNTERS A PROGRESSIVELY DRIER AIRMASS /SEE 00Z SOUNDING FROM MPX LAST NIGHT/. IN THE WAKE OF THIS MORNING ACTIVITY...H85 TEMPS WILL BE INCREASING TO AROUND 20C. LOOKING AT BUFKIT SOUNDINGS FROM ACROSS THE AREA...THIS WILL PUT A DECENT CAP IN PLACE THAT LOOKS TO KEEP A LID ON SURFACE BASED CONVECTION UNTIL ABOUT 00Z. WHERE WE ARE SEEING SOME VARIABILITY THOUGH WITH THE CAMS IS WITH THE POTENTIAL FOR SOME ELEVATED CONVECTION TO DEVELOP THIS AFTERNOON OUT AHEAD OF WHAT YOU COULD CONSIDER THE MAIN SHOW FROM THE SEVERE WEATHER PERSPECTIVE. THIS ELEVATED CONVECTION LOOKS TO BE TIED TO THE STRONG WAVE ON WATER VAPOR CURRENTLY MOVING INTO WRN KS. THIS FEATURE HAS A FEW STORMS ASSOCIATED WITH IT IN KANSAS THIS MORNING AND BY THE AFTERNOON...THIS WAVE WILL BE NEAR THE MN/IA BORDER. THE CAMS THAT ARE MOST BULLISH WITH THIS ACTIVITY ARE THE MPXWRF AND ARW...AND ALTHOUGH IT ENDS AT 21Z...YOU GET A SENSE FROM THE HRRR REFLECTIVITY FORECAST...IT MAY BE GOING THE SAME WAY IN THE NEXT COUPLE OF RUNS. THE IMPACT OF THIS ACTIVITY ON THE FORECAST WAS TO SPREAD HIGHER POPS A BIT FARTHER EAST LATE THIS AFTERNOON THAN THE POSITION OF THE SFC FEATURES WOULD OTHERWISE SUGGEST. AS FOR THE POTENTIAL SFC BASED CONVECTION...THE MAIN TREND SEEN WITH THE CAMS AND 00Z DETERMINISTIC MODELS WAS DELAY ITS START SOME...WHICH MAKE SENSE GIVEN THE CAPPING SEEN IN THE FORECAST SOUNDINGS. CURRENT EXPECTATIONS ARE THAT SFC BASED CONVECTION WILL DEVELOP AROUND 21Z NEAR OMAHA...WHERE INSTABILITY WILL BE MAXIMIZED...WITH INITIATION ALONG THE FRONT UP IN MN COMING A BIT CLOSER TO 00Z. GREATEST SEVERE THREAT REALLY LOOKS TO BE DOWN ACROSS IOWA...WHERE THE COMBINATION OF AN IMPINGING WRLY MID LEVEL JET WITH A 40-50 KT SWRLY LLJ LOOKS TO MAXIMIZE SHEAR. CAN NOT ARGUE WITH THE DAY1 SEVERE PROBABILITIES...WHICH HAS THE GREATER SEVERE POTENTIAL EXISTING FROM I-90 SOUTH. LOOKING AT THE 0-3/0-6 KM SHEAR OF 30-60 KTS WITH VECTORS ORIENTED MOSTLY PERPENDICULAR TO THE FRONT ACROSS IOWA INDICATES THE POTENTIAL FOR GETTING A STRONG MCS WITH STRONG WINDS ACROSS IOWA TONIGHT...WHICH IS WHAT THE NMM/ARW CERTAINLY SHOW EVOLVING. STILL A GOOD DEGREE OF VARIABILITY WITH HOW THIS ACTIVITY WILL EVOLVE ACROSS THE MPX CWA...WITH SOME SUGGESTION THAT WE MAY SEE THE GREATEST THUNDERSTORM ACTIVITY SPLIT THE MPX CWA TO THE NORTH AND SOUTH. CERTAINLY THE HRRR MSLP FORECAST SHOWS SOME MERIT TO THIS POSSIBILITY...WITH TWO SFC LOWS NOTED BY 21Z. ONE UP IN NRN MN AND THE OTHER IN WRN KS. FOR TONIGHT...WE ARE ALSO SEEING THE NMM AND THE ARW TO A LESSER EXTENT HANGING UP ACTIVITY BACK ACROSS THE CENTER OF THE MPX CWA AS THEY BOTH DEVELOP A DEFORMATION BAND IN THE WAKE IN THE MAIN COLD FRONT ACTIVITY. THIS LOOKS TO BE TIED TO THE MAIN SHORT WAVE POSSIBLY MIXED WITH A BIT OF AN MCV MOVING ACROSS THE UPPER MS VALLEY LATE TONIGHT. AS A RESULT...HELD ON TO CHANCE POPS A BIT LONGER BACK ACROSS MOST OF THE MN PORTION OF THE MPX CWA IN THE WAKE OF THE FRONT. THIS ACTIVITY WOULD NOT HAVE MUCH OF A SEVERE THREAT...THOUGH IT WOULD SET UP MORE IN A WAY TO ALLOW FOR SOME TRAINING OF STORMS ALONG A SW TO NE AXIS...SO IT COULD POSE MORE OF A HYDRO THREAT IF IT MATERIALIZES. TO SUMMARIZE...WE EXPECT A BAND OF NON-SEVERE SHOWERS/STORMS TO MOVE ACROSS MN THIS MORNING. STILL A GOOD DEGREE OF UNCERTAINTY WITH RESPECT THE AFTERNOON ACTIVITY...WITH THE POTENTIAL FOR A PREFRONTAL TROUGH TO GET ELEVATED CONVECTION GOING BY EARLY AFTERNOON IN THE EAST...WITH THE GREATEST SEVERE RISK EXISTING FROM ABOUT 6 PM TO MIDNIGHT FROM SOUTH CENTRAL MN INTO IOWA AHEAD OF THE MAIN SFC COLD FRONT. EVENTUALLY...A LINE OR TWO OF STORMS LOOKS TO FORM...WITH THE MAIN SEVERE THREAT BEING DAMAGING STRAIGHT LINE WINDS. HOWEVER...WHERE ACTIVITY INITIALLY DEVELOPS...IT WILL LIKELY BE SUPER CELLULAR IN NATURE...WITH LARGE HAIL AND A FEW TORNADOES BEING POSSIBLE AS WELL...BUT THIS THREAT LOOKS GREATEST FROM ERN NEB INTO WRN IOWA. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 245 AM CDT SUN AUG 31 2014 THE LONGER TERM WILL INCLUDE SOME ADDITIONAL CHANCES FOR SHRA/TSRA AS WE SEE THE LARGE SCALE PATTERN ONCE AGAIN BECOME MORE ZONAL BY THE MIDDLE OF THE WEEK... BEFORE ANOTHER UPPER TROUGH MOVES INTO THE CENTER OF THE COUNTRY TOWARD THE WEEKEND. THE MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH MIDWEEK... BUT DIVERGES A FAIR AMOUNT BY THE WEEKEND... WHICH LEADS TO MORE UNCERTAINTY AND NECESSITATES THE INCLUSION OF CHANCE POPS FOR SEVERAL DAYS. SOME PCPN WILL LIKELY STILL BE ONGOING ACROSS THE EASTERN PORTION OF THE AREA ON MONDAY AS THE FRONTAL BOUNDARY SLOWLY PUSHES EAST INTO THE GREAT LAKES. COULD SEE A FEW SHRA/TSRA SNEAK BACK INTO THE WESTERN AND CENTRAL PORTION OF THE AREA MONDAY NIGHT INTO EARLY TUESDAY AS THE UPPER TROUGH/COLD POOL SWING THROUGH THE REGION. THIS ACTIVITY WILL SHIFT NORTHEAST BY TUESDAY... WITH RETURN FLOW BEGINNING TO SETUP BY TUESDAY NIGHT. CHANCES FOR SHRA/TSRA LOOK TO RETURN FROM WEST TO EAST WEDNESDAY INTO THURSDAY AS A SURFACE LOW SLOWLY TAKES SHAPE OVER THE PLAINS AHEAD OF THE NEXT UPPER TROUGH... WITH A LONG PERIOD OF MAINLY WEAK ISENTROPIC LIFT PROGGED ACROSS OUR AREA. THE SPEED WITH WHICH THE SURFACE LOW MOVES THROUGH OUR AREA VARIES QUITE A BIT AMONGST THE GUIDANCE... AND AT THIS POINT THERE IS TOO MUCH SPREAD IN THE ENSEMBLE SOLUTIONS TO HAVE MUCH CONFIDENCE IN ANYTHING SPECIFIC. UNTIL THE SURFACE LOW AND ASSOCIATED FRONTAL BOUNDARY MOVE THROUGH... WE/LL CONTINUE TO HAVE A NEED FOR AT LEAST CHANCE POPS. THERE IS ALSO UNCERTAINTY IN HOW FAR SOUTH THE BOUNDARY WILL BE DISPLACED ONCE THE SURFACE LOW AND UPPER TROUGH MOVE EAST... WITH THE GUIDANCE SHOWING VARYING AMPLITUDES OF THE UPPER TROUGH WHICH LEADS TO DIFFERENCES IN HOW FAR SOUTH THE BOUNDARY IS DISPLACED AS THE SURFACE HIGH BUILDS INTO THE AREA LATE FRIDAY INTO SATURDAY. AT THIS POINT... KEPT SOME POPS OVER THE SOUTHERN PART OF THE AREA INTO SATURDAY TO ACCOUNT FOR THE POSSIBILITY OF THE BOUNDARY HANGING UP OVER NORTHERN IOWA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1155 AM CDT SUN AUG 31 2014 LOW CONFIDENCE IN TSRA/SHRA DEVELOPMENT AFT 21Z WITH SHORT TERM MODELS HAVING PROBLEMS WITH THE CONVECTION ALREADY DEVELOPING NEAR KRWF/KFRM AS OF 17Z. WILL USE REGIONAL RADAR AND MOVEMENT TRENDS FOR THE FIRST 3 HRS AS THIS LINE BECOMES MORE ORGANIZED AND MOVES OFF TO THE NE. KRWF/KSTC WILL BE MOST IMPACTED IN THE SHORT TERM. ELSEWHERE...TSRA/SHRA SHOULD HOLD OFF UNTIL AFT 21Z...WITH A BETTER CHC AFT 00Z AS THE MAIN UPPER WAVE AND SFC FRONT MOVES CLOSER TO THE AREA. WINDS WILL BE GUSTY THIS AFTN FROM THE S/SW...WITH A MORE SW/WSW BY THE LATE AFTN IN WC/SW MN AND DECREASE TO LESS THAN 10 KTS. EC MN/WC WI WILL LIKELY SEE THE GUSTY WINDS UNTIL 00Z FROM THE S/SSW. AM CONCERN WITH AREAS FROM SC/EC MN...EASTWARD ACROSS WC WI AFT 2Z AS A LARGE AREA OF CONVECTION IS EXPECTED TO DEVELOP. WILL ADJUST AS NECESSARY BUT IFR/MVFR CIGS/VSBYS FOR KRNH/KEAU LOOK MORE LIKELY OVERNIGHT. KMSP... BASED ON THE LATEST REGIONAL RADAR MOST OF THE ACTIVITY SHOULD HOLD OFF TO THE WEST UNTIL AFT 20-21Z...WITH A PERIOD OF VCTS FROM 20-23Z...BUT LOW CONFIDENCE ON AREAL EXTENT. A BETTER CHC OF WIDESPREAD ACTIVITY IS EXPECTED AFT 2Z...WITH A PERIOD OF HEAVY SHRA/TSRA AND LOW VSBYS. AFT 6Z...CHC/S OF SHRA/TSRA DIMINISH...BUT MVFR CIGS AND/OR VSBYS MAY DEVELOP BEHIND THE SFC FRONT...ESPECIALLY DURING THE TYPICAL 09-14Z TIME FRAME. IF MVFR CIGS DEVELOP...DO NOT EXPECT VFR CONDS UNTIL AFT 16-18Z ON MONDAY. /OUTLOOK FOR KMSP/ MON...VFR BY AFTERNOON WINDS WNW 5-10 KTS. TUE...VFR. WINDS WSW 5-10 KTS. WED...VFR. CHC MVFR/TSRA LATE. WINDS S 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM... AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
609 AM CDT SUN AUG 31 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 245 AM CDT SUN AUG 31 2014 ALTHOUGH SUNDAY AND ITS POTENTIAL SEVERE WEATHER EVENT ARE HERE...THE CAMS STILL LEAVE PLENTY OF QUESTIONS AS TO HOW THINGS WILL EVOLVE LATER TODAY. FOR THIS MORNING...INITIAL SURGE OF THE LLJ IS MOVING ACROSS THE DAKOTAS OUT AHEAD OF SHORTWAVE THAT CAN BE SEEN ON WATER VAPOR MOVING INTO CENTRAL SODAK. ALTHOUGH BEST FORCING AND MOST WIDESPREAD THUNDERSTORM ACTIVITY CAN BE FOUND AT THE NOSE OF THE LLJ ACROSS NODAK AND ON ITS WAY TO NW MN...ENOUGH THETA-E ADVECTION AND ISENTROPIC LIFT IS PRESENT ON THE ERN FLANK OF THE LLJ TO GET SCT CONVECTION DOWN INTO NE NEB. THE HRRR/HOPWRF/MPXWRF/NMM/ARW ALL SHOW THIS BAND OF ISO/SCT SHOWERS WORKING ACROSS MN THROUGH THE MORNING...SO WORKED SOME 20/30 POPS ACROSS MN THIS MORNING TO ACCOUNT FOR THAT. EXPECT THIS ACTIVITY TO START WEAKENING AS IT MOVES EAST ACROSS MN AND LIKELY WILL NOT MAKE IT INTO WI AS IT ENCOUNTERS A PROGRESSIVELY DRIER AIRMASS /SEE 00Z SOUNDING FROM MPX LAST NIGHT/. IN THE WAKE OF THIS MORNING ACTIVITY...H85 TEMPS WILL BE INCREASING TO AROUND 20C. LOOKING AT BUFKIT SOUNDINGS FROM ACROSS THE AREA...THIS WILL PUT A DECENT CAP IN PLACE THAT LOOKS TO KEEP A LID ON SURFACE BASED CONVECTION UNTIL ABOUT 00Z. WHERE WE ARE SEEING SOME VARIABILITY THOUGH WITH THE CAMS IS WITH THE POTENTIAL FOR SOME ELEVATED CONVECTION TO DEVELOP THIS AFTERNOON OUT AHEAD OF WHAT YOU COULD CONSIDER THE MAIN SHOW FROM THE SEVERE WEATHER PERSPECTIVE. THIS ELEVATED CONVECTION LOOKS TO BE TIED TO THE STRONG WAVE ON WATER VAPOR CURRENTLY MOVING INTO WRN KS. THIS FEATURE HAS A FEW STORMS ASSOCIATED WITH IT IN KANSAS THIS MORNING AND BY THE AFTERNOON...THIS WAVE WILL BE NEAR THE MN/IA BORDER. THE CAMS THAT ARE MOST BULLISH WITH THIS ACTIVITY ARE THE MPXWRF AND ARW...AND ALTHOUGH IT ENDS AT 21Z...YOU GET A SENSE FROM THE HRRR REFLECTIVITY FORECAST...IT MAY BE GOING THE SAME WAY IN THE NEXT COUPLE OF RUNS. THE IMPACT OF THIS ACTIVITY ON THE FORECAST WAS TO SPREAD HIGHER POPS A BIT FARTHER EAST LATE THIS AFTERNOON THAN THE POSITION OF THE SFC FEATURES WOULD OTHERWISE SUGGEST. AS FOR THE POTENTIAL SFC BASED CONVECTION...THE MAIN TREND SEEN WITH THE CAMS AND 00Z DETERMINISTIC MODELS WAS DELAY ITS START SOME...WHICH MAKE SENSE GIVEN THE CAPPING SEEN IN THE FORECAST SOUNDINGS. CURRENT EXPECTATIONS ARE THAT SFC BASED CONVECTION WILL DEVELOP AROUND 21Z NEAR OMAHA...WHERE INSTABILITY WILL BE MAXIMIZED...WITH INITIATION ALONG THE FRONT UP IN MN COMING A BIT CLOSER TO 00Z. GREATEST SEVERE THREAT REALLY LOOKS TO BE DOWN ACROSS IOWA...WHERE THE COMBINATION OF AN IMPINGING WRLY MID LEVEL JET WITH A 40-50 KT SWRLY LLJ LOOKS TO MAXIMIZE SHEAR. CAN NOT ARGUE WITH THE DAY1 SEVERE PROBABILITIES...WHICH HAS THE GREATER SEVERE POTENTIAL EXISTING FROM I-90 SOUTH. LOOKING AT THE 0-3/0-6 KM SHEAR OF 30-60 KTS WITH VECTORS ORIENTED MOSTLY PERPENDICULAR TO THE FRONT ACROSS IOWA INDICATES THE POTENTIAL FOR GETTING A STRONG MCS WITH STRONG WINDS ACROSS IOWA TONIGHT...WHICH IS WHAT THE NMM/ARW CERTAINLY SHOW EVOLVING. STILL A GOOD DEGREE OF VARIABILITY WITH HOW THIS ACTIVITY WILL EVOLVE ACROSS THE MPX CWA...WITH SOME SUGGESTION THAT WE MAY SEE THE GREATEST THUNDERSTORM ACTIVITY SPLIT THE MPX CWA TO THE NORTH AND SOUTH. CERTAINLY THE HRRR MSLP FORECAST SHOWS SOME MERIT TO THIS POSSIBILITY...WITH TWO SFC LOWS NOTED BY 21Z. ONE UP IN NRN MN AND THE OTHER IN WRN KS. FOR TONIGHT...WE ARE ALSO SEEING THE NMM AND THE ARW TO A LESSER EXTENT HANGING UP ACTIVITY BACK ACROSS THE CENTER OF THE MPX CWA AS THEY BOTH DEVELOP A DEFORMATION BAND IN THE WAKE IN THE MAIN COLD FRONT ACTIVITY. THIS LOOKS TO BE TIED TO THE MAIN SHORT WAVE POSSIBLY MIXED WITH A BIT OF AN MCV MOVING ACROSS THE UPPER MS VALLEY LATE TONIGHT. AS A RESULT...HELD ON TO CHANCE POPS A BIT LONGER BACK ACROSS MOST OF THE MN PORTION OF THE MPX CWA IN THE WAKE OF THE FRONT. THIS ACTIVITY WOULD NOT HAVE MUCH OF A SEVERE THREAT...THOUGH IT WOULD SET UP MORE IN A WAY TO ALLOW FOR SOME TRAINING OF STORMS ALONG A SW TO NE AXIS...SO IT COULD POSE MORE OF A HYDRO THREAT IF IT MATERIALIZES. TO SUMMARIZE...WE EXPECT A BAND OF NON-SEVERE SHOWERS/STORMS TO MOVE ACROSS MN THIS MORNING. STILL A GOOD DEGREE OF UNCERTAINTY WITH RESPECT THE AFTERNOON ACTIVITY...WITH THE POTENTIAL FOR A PREFRONTAL TROUGH TO GET ELEVATED CONVECTION GOING BY EARLY AFTERNOON IN THE EAST...WITH THE GREATEST SEVERE RISK EXISTING FROM ABOUT 6 PM TO MIDNIGHT FROM SOUTH CENTRAL MN INTO IOWA AHEAD OF THE MAIN SFC COLD FRONT. EVENTUALLY...A LINE OR TWO OF STORMS LOOKS TO FORM...WITH THE MAIN SEVERE THREAT BEING DAMAGING STRAIGHT LINE WINDS. HOWEVER...WHERE ACTIVITY INITIALLY DEVELOPS...IT WILL LIKELY BE SUPER CELLULAR IN NATURE...WITH LARGE HAIL AND A FEW TORNADOES BEING POSSIBLE AS WELL...BUT THIS THREAT LOOKS GREATEST FROM ERN NEB INTO WRN IOWA. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 245 AM CDT SUN AUG 31 2014 THE LONGER TERM WILL INCLUDE SOME ADDITIONAL CHANCES FOR SHRA/TSRA AS WE SEE THE LARGE SCALE PATTERN ONCE AGAIN BECOME MORE ZONAL BY THE MIDDLE OF THE WEEK... BEFORE ANOTHER UPPER TROUGH MOVES INTO THE CENTER OF THE COUNTRY TOWARD THE WEEKEND. THE MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH MIDWEEK... BUT DIVERGES A FAIR AMOUNT BY THE WEEKEND... WHICH LEADS TO MORE UNCERTAINTY AND NECESSITATES THE INCLUSION OF CHANCE POPS FOR SEVERAL DAYS. SOME PCPN WILL LIKELY STILL BE ONGOING ACROSS THE EASTERN PORTION OF THE AREA ON MONDAY AS THE FRONTAL BOUNDARY SLOWLY PUSHES EAST INTO THE GREAT LAKES. COULD SEE A FEW SHRA/TSRA SNEAK BACK INTO THE WESTERN AND CENTRAL PORTION OF THE AREA MONDAY NIGHT INTO EARLY TUESDAY AS THE UPPER TROUGH/COLD POOL SWING THROUGH THE REGION. THIS ACTIVITY WILL SHIFT NORTHEAST BY TUESDAY... WITH RETURN FLOW BEGINNING TO SETUP BY TUESDAY NIGHT. CHANCES FOR SHRA/TSRA LOOK TO RETURN FROM WEST TO EAST WEDNESDAY INTO THURSDAY AS A SURFACE LOW SLOWLY TAKES SHAPE OVER THE PLAINS AHEAD OF THE NEXT UPPER TROUGH... WITH A LONG PERIOD OF MAINLY WEAK ISENTROPIC LIFT PROGGED ACROSS OUR AREA. THE SPEED WITH WHICH THE SURFACE LOW MOVES THROUGH OUR AREA VARIES QUITE A BIT AMONGST THE GUIDANCE... AND AT THIS POINT THERE IS TOO MUCH SPREAD IN THE ENSEMBLE SOLUTIONS TO HAVE MUCH CONFIDENCE IN ANYTHING SPECIFIC. UNTIL THE SURFACE LOW AND ASSOCIATED FRONTAL BOUNDARY MOVE THROUGH... WE/LL CONTINUE TO HAVE A NEED FOR AT LEAST CHANCE POPS. THERE IS ALSO UNCERTAINTY IN HOW FAR SOUTH THE BOUNDARY WILL BE DISPLACED ONCE THE SURFACE LOW AND UPPER TROUGH MOVE EAST... WITH THE GUIDANCE SHOWING VARYING AMPLITUDES OF THE UPPER TROUGH WHICH LEADS TO DIFFERENCES IN HOW FAR SOUTH THE BOUNDARY IS DISPLACED AS THE SURFACE HIGH BUILDS INTO THE AREA LATE FRIDAY INTO SATURDAY. AT THIS POINT... KEPT SOME POPS OVER THE SOUTHERN PART OF THE AREA INTO SATURDAY TO ACCOUNT FOR THE POSSIBILITY OF THE BOUNDARY HANGING UP OVER NORTHERN IOWA. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 558 AM CDT SUN AUG 31 2014 EXTENSIVE FOG/LOW STRATUS THAT DEVELOPED OVER WI BENEATH THE SFC HIGH HAS MANAGED TO WORK INTO ERN MN/WRN WI ON SOUTHEAST WINDS THIS MORNING. AS WINDS CONTINUE TO BECOME MORE SRLY AND PICK UP IN STRENGTH...WE SHOULD SEE THESE CLOUDS MIX OUT PRETTY QUICK THIS MORNING. SHOWERS THAT SNUCK INTO WRN MN EARLY THIS MORNING WILL CONTINUE TO SLOWLY FALL APPART AS THEY WORK ACROSS MN AND FEEL VCSH MENTIONS AT MN TERMINALS IS ENOUGH FOR THIS MORNING. FOR THE AFTERNOON...BEGINNING TO FAVOR THE HRRR/ARW TREND FOR STORMS TODAY...WITH STORMS DEVELOPING NEAR THE MN/WI BORDER AROUND 20Z ON A LEAD TROUGH...WITH THE MAIN COLD FRONTAL ACTIVITY NOT LOOKING TO REALLY GET GOING IN MN UNTIL AFTER 00Z. BEHIND THIS ACTIVITY...GFSLAMP IS WANTING TO DEVELOP LOW STRATUS...BUT 925-850 RH FORECASTS FROM THE NAM/GFS INDICATE THE STRATUS BEING FAVORED FOR NRN MN...SO KEPT CIGS VFR TONIGHT. KMSP...CONFIDENCE IS NOT AT THE CERTAIN LEVEL FOR MSP GETTING STORMS THIS AFTERNOON...AS SEVERAL OF THE CAMS ARE SHOWING AFTERNOON ACTIVITY MAINLY IMPACTING WI...WHILE STRONGER STORMS TONIGHT STAY OFF TO THE SOUTH. IT IS THIS SECONDARY ACTIVITY THOUGH THAT LOOKS TO HAVE THE GREATEST POTENTIAL FOR IMPACTING THE FIELD...WHICH IS WHY THE TEMPO GROUP IS STILL THERE FROM 1-4Z. MOVED THE VCTS MENTION UP TO 21Z TO ACCOUNT FOR UNCERTAINTY FOR WHERE STORMS WILL DEVELOP ALONG THE PREFRONTAL TROUGH THIS AFTERNOON. GIVEN STRENGTH OF WINDS...SHOULD NOT TAKE TOO LONG TO MIX OUT LOW STRATUS THIS MORNING...WITH THAT LOOKING TO OCCUR BETWEEN 14Z AND 15Z. /OUTLOOK FOR KMSP/ MON...MVFR/TSRA ENDING EARLY. VFR BY AFTERNOON WINDS WNW 5-10 KTS. TUE...VFR. WINDS WSW 5-10 KTS. WED...VFR. CHC MVFR/TSRA LATE. WINDS S 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM... AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
338 AM CDT SUN AUG 31 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 245 AM CDT SUN AUG 31 2014 ALTHOUGH SUNDAY AND ITS POTENTIAL SEVERE WEATHER EVENT ARE HERE...THE CAMS STILL LEAVE PLENTY OF QUESTIONS AS TO HOW THINGS WILL EVOLVE LATER TODAY. FOR THIS MORNING...INITIAL SURGE OF THE LLJ IS MOVING ACROSS THE DAKOTAS OUT AHEAD OF SHORTWAVE THAT CAN BE SEEN ON WATER VAPOR MOVING INTO CENTRAL SODAK. ALTHOUGH BEST FORCING AND MOST WIDESPREAD THUNDERSTORM ACTIVITY CAN BE FOUND AT THE NOSE OF THE LLJ ACROSS NODAK AND ON ITS WAY TO NW MN...ENOUGH THETA-E ADVECTION AND ISENTROPIC LIFT IS PRESENT ON THE ERN FLANK OF THE LLJ TO GET SCT CONVECTION DOWN INTO NE NEB. THE HRRR/HOPWRF/MPXWRF/NMM/ARW ALL SHOW THIS BAND OF ISO/SCT SHOWERS WORKING ACROSS MN THROUGH THE MORNING...SO WORKED SOME 20/30 POPS ACROSS MN THIS MORNING TO ACCOUNT FOR THAT. EXPECT THIS ACTIVITY TO START WEAKENING AS IT MOVES EAST ACROSS MN AND LIKELY WILL NOT MAKE IT INTO WI AS IT ENCOUNTERS A PROGRESSIVELY DRIER AIRMASS /SEE 00Z SOUNDING FROM MPX LAST NIGHT/. IN THE WAKE OF THIS MORNING ACTIVITY...H85 TEMPS WILL BE INCREASING TO AROUND 20C. LOOKING AT BUFKIT SOUNDINGS FROM ACROSS THE AREA...THIS WILL PUT A DECENT CAP IN PLACE THAT LOOKS TO KEEP A LID ON SURFACE BASED CONVECTION UNTIL ABOUT 00Z. WHERE WE ARE SEEING SOME VARIABILITY THOUGH WITH THE CAMS IS WITH THE POTENTIAL FOR SOME ELEVATED CONVECTION TO DEVELOP THIS AFTERNOON OUT AHEAD OF WHAT YOU COULD CONSIDER THE MAIN SHOW FROM THE SEVERE WEATHER PERSPECTIVE. THIS ELEVATED CONVECTION LOOKS TO BE TIED TO THE STRONG WAVE ON WATER VAPOR CURRENTLY MOVING INTO WRN KS. THIS FEATURE HAS A FEW STORMS ASSOCIATED WITH IT IN KANSAS THIS MORNING AND BY THE AFTERNOON...THIS WAVE WILL BE NEAR THE MN/IA BORDER. THE CAMS THAT ARE MOST BULLISH WITH THIS ACTIVITY ARE THE MPXWRF AND ARW...AND ALTHOUGH IT ENDS AT 21Z...YOU GET A SENSE FROM THE HRRR REFLECTIVITY FORECAST...IT MAY BE GOING THE SAME WAY IN THE NEXT COUPLE OF RUNS. THE IMPACT OF THIS ACTIVITY ON THE FORECAST WAS TO SPREAD HIGHER POPS A BIT FARTHER EAST LATE THIS AFTERNOON THAN THE POSITION OF THE SFC FEATURES WOULD OTHERWISE SUGGEST. AS FOR THE POTENTIAL SFC BASED CONVECTION...THE MAIN TREND SEEN WITH THE CAMS AND 00Z DETERMINISTIC MODELS WAS DELAY ITS START SOME...WHICH MAKE SENSE GIVEN THE CAPPING SEEN IN THE FORECAST SOUNDINGS. CURRENT EXPECTATIONS ARE THAT SFC BASED CONVECTION WILL DEVELOP AROUND 21Z NEAR OMAHA...WHERE INSTABILITY WILL BE MAXIMIZED...WITH INITIATION ALONG THE FRONT UP IN MN COMING A BIT CLOSER TO 00Z. GREATEST SEVERE THREAT REALLY LOOKS TO BE DOWN ACROSS IOWA...WHERE THE COMBINATION OF AN IMPINGING WRLY MID LEVEL JET WITH A 40-50 KT SWRLY LLJ LOOKS TO MAXIMIZE SHEAR. CAN NOT ARGUE WITH THE DAY1 SEVERE PROBABILITIES...WHICH HAS THE GREATER SEVERE POTENTIAL EXISTING FROM I-90 SOUTH. LOOKING AT THE 0-3/0-6 KM SHEAR OF 30-60 KTS WITH VECTORS ORIENTED MOSTLY PERPENDICULAR TO THE FRONT ACROSS IOWA INDICATES THE POTENTIAL FOR GETTING A STRONG MCS WITH STRONG WINDS ACROSS IOWA TONIGHT...WHICH IS WHAT THE NMM/ARW CERTAINLY SHOW EVOLVING. STILL A GOOD DEGREE OF VARIABILITY WITH HOW THIS ACTIVITY WILL EVOLVE ACROSS THE MPX CWA...WITH SOME SUGGESTION THAT WE MAY SEE THE GREATEST THUNDERSTORM ACTIVITY SPLIT THE MPX CWA TO THE NORTH AND SOUTH. CERTAINLY THE HRRR MSLP FORECAST SHOWS SOME MERIT TO THIS POSSIBILITY...WITH TWO SFC LOWS NOTED BY 21Z. ONE UP IN NRN MN AND THE OTHER IN WRN KS. FOR TONIGHT...WE ARE ALSO SEEING THE NMM AND THE ARW TO A LESSER EXTENT HANGING UP ACTIVITY BACK ACROSS THE CENTER OF THE MPX CWA AS THEY BOTH DEVELOP A DEFORMATION BAND IN THE WAKE IN THE MAIN COLD FRONT ACTIVITY. THIS LOOKS TO BE TIED TO THE MAIN SHORT WAVE POSSIBLY MIXED WITH A BIT OF AN MCV MOVING ACROSS THE UPPER MS VALLEY LATE TONIGHT. AS A RESULT...HELD ON TO CHANCE POPS A BIT LONGER BACK ACROSS MOST OF THE MN PORTION OF THE MPX CWA IN THE WAKE OF THE FRONT. THIS ACTIVITY WOULD NOT HAVE MUCH OF A SEVERE THREAT...THOUGH IT WOULD SET UP MORE IN A WAY TO ALLOW FOR SOME TRAINING OF STORMS ALONG A SW TO NE AXIS...SO IT COULD POSE MORE OF A HYDRO THREAT IF IT MATERIALIZES. TO SUMMARIZE...WE EXPECT A BAND OF NON-SEVERE SHOWERS/STORMS TO MOVE ACROSS MN THIS MORNING. STILL A GOOD DEGREE OF UNCERTAINTY WITH RESPECT THE AFTERNOON ACTIVITY...WITH THE POTENTIAL FOR A PREFRONTAL TROUGH TO GET ELEVATED CONVECTION GOING BY EARLY AFTERNOON IN THE EAST...WITH THE GREATEST SEVERE RISK EXISTING FROM ABOUT 6 PM TO MIDNIGHT FROM SOUTH CENTRAL MN INTO IOWA AHEAD OF THE MAIN SFC COLD FRONT. EVENTUALLY...A LINE OR TWO OF STORMS LOOKS TO FORM...WITH THE MAIN SEVERE THREAT BEING DAMAGING STRAIGHT LINE WINDS. HOWEVER...WHERE ACTIVITY INITIALLY DEVELOPS...IT WILL LIKELY BE SUPER CELLULAR IN NATURE...WITH LARGE HAIL AND A FEW TORNADOES BEING POSSIBLE AS WELL...BUT THIS THREAT LOOKS GREATEST FROM ERN NEB INTO WRN IOWA. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 245 AM CDT SUN AUG 31 2014 THE LONGER TERM WILL INCLUDE SOME ADDITIONAL CHANCES FOR SHRA/TSRA AS WE SEE THE LARGE SCALE PATTERN ONCE AGAIN BECOME MORE ZONAL BY THE MIDDLE OF THE WEEK... BEFORE ANOTHER UPPER TROUGH MOVES INTO THE CENTER OF THE COUNTRY TOWARD THE WEEKEND. THE MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH MIDWEEK... BUT DIVERGES A FAIR AMOUNT BY THE WEEKEND... WHICH LEADS TO MORE UNCERTAINTY AND NECESSITATES THE INCLUSION OF CHANCE POPS FOR SEVERAL DAYS. SOME PCPN WILL LIKELY STILL BE ONGOING ACROSS THE EASTERN PORTION OF THE AREA ON MONDAY AS THE FRONTAL BOUNDARY SLOWLY PUSHES EAST INTO THE GREAT LAKES. COULD SEE A FEW SHRA/TSRA SNEAK BACK INTO THE WESTERN AND CENTRAL PORTION OF THE AREA MONDAY NIGHT INTO EARLY TUESDAY AS THE UPPER TROUGH/COLD POOL SWING THROUGH THE REGION. THIS ACTIVITY WILL SHIFT NORTHEAST BY TUESDAY... WITH RETURN FLOW BEGINNING TO SETUP BY TUESDAY NIGHT. CHANCES FOR SHRA/TSRA LOOK TO RETURN FROM WEST TO EAST WEDNESDAY INTO THURSDAY AS A SURFACE LOW SLOWLY TAKES SHAPE OVER THE PLAINS AHEAD OF THE NEXT UPPER TROUGH... WITH A LONG PERIOD OF MAINLY WEAK ISENTROPIC LIFT PROGGED ACROSS OUR AREA. THE SPEED WITH WHICH THE SURFACE LOW MOVES THROUGH OUR AREA VARIES QUITE A BIT AMONGST THE GUIDANCE... AND AT THIS POINT THERE IS TOO MUCH SPREAD IN THE ENSEMBLE SOLUTIONS TO HAVE MUCH CONFIDENCE IN ANYTHING SPECIFIC. UNTIL THE SURFACE LOW AND ASSOCIATED FRONTAL BOUNDARY MOVE THROUGH... WE/LL CONTINUE TO HAVE A NEED FOR AT LEAST CHANCE POPS. THERE IS ALSO UNCERTAINTY IN HOW FAR SOUTH THE BOUNDARY WILL BE DISPLACED ONCE THE SURFACE LOW AND UPPER TROUGH MOVE EAST... WITH THE GUIDANCE SHOWING VARYING AMPLITUDES OF THE UPPER TROUGH WHICH LEADS TO DIFFERENCES IN HOW FAR SOUTH THE BOUNDARY IS DISPLACED AS THE SURFACE HIGH BUILDS INTO THE AREA LATE FRIDAY INTO SATURDAY. AT THIS POINT... KEPT SOME POPS OVER THE SOUTHERN PART OF THE AREA INTO SATURDAY TO ACCOUNT FOR THE POSSIBILITY OF THE BOUNDARY HANGING UP OVER NORTHERN IOWA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1233 AM CDT SUN AUG 31 2014 WITH THE HRRR ALONG WITH VIRTUALLY ALL OTHER CAMS SHOWING A BAND OF SHRA/TSRA WORKING ACROSS MN WITH INITIAL ARRIVAL OF THE LLJ...STARTED TO INTRODUCE VCSH IN THE MORNING TO ALL MN TERMINALS. THIS SCENARIO SEEMS VERY PLAUSIBLE GIVEN THE FACT THAT WE ARE CURRENTLY SEEING SCT ACTIVITY CLEAR DOWN INTO NC NEB. THE ATMO HAS ALREADY TIPPED ITS HAND WHEN IT COMES TO FOG AT EAU...SO HAVE LEFT THEM DOWN THE REST OF THE NIGHT. WITH THAT SAID...THERE IS STILL A FAIR AMOUNT OF CLOUD COVER IN THE 050-080 LEVEL IN ERN MN INTO WRN WI...WHICH MAY LEAD TO A BIT OF VARIABILITY IN THE VSBYS AT RNH/EAU AS THEY SKIP BETWEEN 050-080 CLOUDS AND CLEAR SKIES /WHICH WILL BE ACCOMPANIED BY FOG/. STILL A GOOD DEGREE OF VARIABILITY WITH THE 00Z CAMS IN TERMS OF AFTERNOON CONVECTION...BUT FORECAST SOUNDINGS DO SHOW A GOOD DEGREE OF CAPPING TO OVERCOME FIRST...SO DID DELAY AFTERNOON TS MENTION AN HOUR OR TWO FROM WHAT THE 00Z TAF HAD. IN ADDITION...REMOVED THE AFTERNOON TS MENTION AT AXN...WITH AXN LOOKING TO MOST LIKELY BE WEST OF THAT ROUND OF STORMS. KMSP...BEGINNING TO GAIN CONFIDENCE IN AT LEAST SCT SHRA/TSRA IN THE METRO AREA THIS MORNING...SO HAVE STARTED WITH INTRODUCING A VCSH GROUP. BY 9Z...SHOULD HAVE A BETTER FEEL FOR WHETHER OR NOT WE WILL SEE ANYTHING...SO WILL WAIT FOR THAT AMD TO SEE IF WE NEED ANY STRONGER SHRA/TSRA MENTION. 00Z TAF LOOKED TO HAVE GOOD TIMING FOR POTENTIAL AFTERNOON TSRA...SO STUCK WITH THAT. IS POTENTIAL THAT MSP COULD GET SPLIT BY ACTIVITY TODAY...WITH STRONGER ACTIVITY REMAINING SOUTH OF THE FIELD WITH BETTER LLJ FORCING DOWN IN IOWA AND GOING NORTH OF THE FIELD...CLOSER TO THE SFC LOW THAT WILL BE GOING ACROSS NRN MN. STILL...GIVEN THE STRENGTH OF THE FRONT/FORCING...ODDS LOOK BETTER THAT MSP WILL SEE SOME TSRA ACTIVITY THAN STORMS MISSING THE AIRPORT. /OUTLOOK FOR KMSP/ MON...MVFR/TSRA ENDING EARLY. VFR BY AFTERNOON WINDS WNW 5-10 KTS. TUE...VFR. WINDS WSW 5-10 KTS. WED...VFR. CHC MVFR/TSRA LATE. WINDS S 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM... AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1252 AM CDT SUN AUG 31 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 242 PM CDT SAT AUG 30 2014 WEAK CONVERGENCE ZONE ALONG WITH MLCAPES AROUND 500 J/KG HAD GENERATED A FEW SHRA ACROSS SOUTHERN MN TODAY. BOUNDARY LAYER MOISTURE REMAINS ROBUST...SO CLOUDS HAVE BEEN SLOW TO ERODE DURING THE TYPICAL DIURNAL AFTERNOON TIME FRAME. AS WINDS REMAIN WEAK AND CYCLONIC CONTINUES DURING THE LATE AFTERNOON/EARLY EVENING...THESE LOW CLOUDS MAY HOLD ON UNTIL LATER TONIGHT. ONCE WINDS SHIFT TO THE SOUTHEAST AHEAD OF A DEEPENING AREA OF LOW PRESSURE ACROSS SD LATER TONIGHT...ANY LOW CLOUDS SHOULD QUICKLY MOVE OUT OR DISSIPATE. SOME FOG MAY DEVELOP ACROSS WC WI AS THIS AREA WILL BE LAST TO SEE BOUNDARY LAYER MOISTURE RETREAT ALONG WITH WEAK MIXING IN THE BOUNDARY LAYER. A STRONG JET STREAM MOVING INTO THE PACIFIC NW TODAY WILL SET THE STAGE FOR A VERY ACTIVE SUNDAY AFTERNOON/EVENING ACROSS THE UPPER MIDWEST. BOTH AMPLE MOISTURE AND INCREASING SHEAR VALUES...ALONG A DEEPENING AREA OF LOW PRESSURE ACROSS THE NORTHERN PLAINS...SHOULD LEAD TO WIDESPREAD THUNDERSTORMS DEVELOPMENT BY THE LATE AFTERNOON AHEAD OF A COLD FRONT. THERE REMAINS SOME DIFFERENCES IN THE MODELS IN TERMS OF STRENGTH OF THE LLJ ALONG WITH THE UPPER LEVEL JET CORE TO CONCLUDE WIDESPREAD SEVERE WX ACROSS THE UPPER MIDWEST. THE UPPER JET CORE...WHICH IS EXPECTED TO BECOME A JET COUPLET FROM THE NORTHERN AND SOUTHERN JET STREAMS...SHOULD LEAD TO STRONG UPPER LEVEL DIFFLUENCE BY SUNDAY EVENING. AGAIN...MODELS HAVE SOME DIFFERENCES IN THIS JET COUPLET WHICH LEADS TO DIFFERENCES IN TIMING AND PLACEMENT OF THE HIGHER QPF AMOUNTS. IN ADDITION...RESIDUAL CLOUD COVER FROM DECAYING MORNING TSRA COULD LIMIT FULL AFTERNOON ISOLATION. THE BEST AREA FOR BOTH JET STRUCTURE/HIGHER INSTABILITY AND SHEAR VALUES REMAIN ACROSS IOWA. FAR SC/SW MN COULD ALSO BE IN THIS AREA OF HIGHER SVR WX POTENTIAL. LATER SHIFTS WILL NEED MONITOR STRENGTH OF THIS JET ALONG WITH TSRA DEVELOPMENT TOWARD MORNING. IN ADDITION TO THE SVR WX THREAT...PWATS VALUES RISE INTO THE 1.5" RANGE. IF ANY TSRA BEGIN TO TRAIN OR BACK BUILD...FLASH FLOODING IS POSSIBLE...ESPECIALLY ONCE THE LLJ INCREASES DURING THE EVENING HRS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 242 PM CDT SAT AUG 30 2014 POTENT COLD FRONT WILL HAVE SHIFTED THROUGH MUCH OF THE MPX CWFA BY DAYBREAK MON MORNING...WITH IT PROGRESSING JUST BARELY INTO WRN WI AND SERN MN. SOME LINGERING SHOWERS/TSTMS WILL LIKELY BE ONGOING IN FAR ERN PORTIONS OF THE CWFA AT THE START OF THIS PERIOD BUT STRENGTH WILL BE FAIRLY WEAK...MEANING THAT ANY SEVERE POTENTIAL WILL HAVE BEEN TAPPED BY THIS POINT. SUPPORTING THIS FACT IS THAT THE UPPER LEVEL TROF AXIS WILL BE E OF THE CWFA AND THE FRONT WILL BE RATHER STRETCHED OUT BETWEEN THE MAIN LOW PRES CENTER OVER WRN ONTARIO PROVINCE AND A SECONDARY LOW PRES CENTER OVER KS. HIGH PRES WILL THEN NUDGE IN FROM THE CENTRAL PLAINS WHILE FLOW ALOFT IS MAINLY ZONAL WNW-ESE. A FEW BUCKLES IN THE FLOW WITHIN A PERSISTENTLY DEEP MOIST ATMO MAY PRODUCE ISOLATED SHOWERS FROM TIME TO TIME LATE MON THRU MUCH OF WED. THIS AREA OF HIGH PRES WILL SHIFT E INTO THE MID-MISS RIVER VALLEY THEN OHIO VALLEY BY WED MORNING... ALLOWING FOR A WARMER AND MORE MOIST SLY RETURN FLOW TO DEVELOP BY MIDDAY WED. THE ADDITIONAL MOISTURE WILL PRECEDE THE ARRIVAL OF A SLOW-MOVING LOW PRES CENTER FROM THE NRN ROCKIES WED NIGHT. THIS LOW WILL STALL OUT OVER THE NRN PLAINS...HELPING SET UP A SFC FRONTAL BOUNDARY EXTENDING FROM WRN MN ACROSS THE ROCKIES. THIS BOUNDARY WILL ACT AS A LOW-LEVEL CONFLUENT ZONE AND AID IN PRECIPITATION DEVELOPMENT THU THROUGH SAT. NOT LOOKING FOR A LOT IN THE WAY OF QPF NOR STORM STRENGTH...BUT FINDING SOLID DRY TIME WILL BE DIFFICULT DUE TO SCATTERED SHOWERS FOR MUCH OF THE LATTER PORTION OF THE WEEK. CANNOT SAY ANY DAY WILL BE A WASHOUT ATTM...BUT ALSO HARD TO PINPOINT ONE TIMEFRAME OVER ANOTHER FOR BEST TIMING OF PRECIPITATION. TEMPERATURES LOOK TO GO ON A SLOW WARMING TREND THRU THE WORKWEEK...CLIMBING THROUGH THE MID-UPR 70S INTO THE LWR 80S BY FRI. HOWEVER...THERE WILL BE PLENTY OF CLOUD/RAIN COMPLICATIONS WHICH ON SMALL SCALES MAY CREATE SOME VARIETY WITH MAX/MIN TEMPS. BY SAT... THIS LOW PRES COMPLEX WILL SHIFT S AND E OF THE MPX CWFA...ALLOWING FOR A COOLING OF TEMPERATURES FOR NEXT WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1233 AM CDT SUN AUG 31 2014 WITH THE HRRR ALONG WITH VIRTUALLY ALL OTHER CAMS SHOWING A BAND OF SHRA/TSRA WORKING ACROSS MN WITH INITIAL ARRIVAL OF THE LLJ...STARTED TO INTRODUCE VCSH IN THE MORNING TO ALL MN TERMINALS. THIS SCENARIO SEEMS VERY PLAUSIBLE GIVEN THE FACT THAT WE ARE CURRENTLY SEEING SCT ACTIVITY CLEAR DOWN INTO NC NEB. THE ATMO HAS ALREADY TIPPED ITS HAND WHEN IT COMES TO FOG AT EAU...SO HAVE LEFT THEM DOWN THE REST OF THE NIGHT. WITH THAT SAID...THERE IS STILL A FAIR AMOUNT OF CLOUD COVER IN THE 050-080 LEVEL IN ERN MN INTO WRN WI...WHICH MAY LEAD TO A BIT OF VARIABILITY IN THE VSBYS AT RNH/EAU AS THEY SKIP BETWEEN 050-080 CLOUDS AND CLEAR SKIES /WHICH WILL BE ACCOMPANIED BY FOG/. STILL A GOOD DEGREE OF VARIABILITY WITH THE 00Z CAMS IN TERMS OF AFTERNOON CONVECTION...BUT FORECAST SOUNDINGS DO SHOW A GOOD DEGREE OF CAPPING TO OVERCOME FIRST...SO DID DELAY AFTERNOON TS MENTION AN HOUR OR TWO FROM WHAT THE 00Z TAF HAD. IN ADDITION...REMOVED THE AFTERNOON TS MENTION AT AXN...WITH AXN LOOKING TO MOST LIKELY BE WEST OF THAT ROUND OF STORMS. KMSP...BEGINNING TO GAIN CONFIDENCE IN AT LEAST SCT SHRA/TSRA IN THE METRO AREA THIS MORNING...SO HAVE STARTED WITH INTRODUCING A VCSH GROUP. BY 9Z...SHOULD HAVE A BETTER FEEL FOR WHETHER OR NOT WE WILL SEE ANYTHING...SO WILL WAIT FOR THAT AMD TO SEE IF WE NEED ANY STRONGER SHRA/TSRA MENTION. 00Z TAF LOOKED TO HAVE GOOD TIMING FOR POTENTIAL AFTERNOON TSRA...SO STUCK WITH THAT. IS POTENTIAL THAT MSP COULD GET SPLIT BY ACTIVITY TODAY...WITH STRONGER ACTIVITY REMAINING SOUTH OF THE FIELD WITH BETTER LLJ FORCING DOWN IN IOWA AND GOING NORTH OF THE FIELD...CLOSER TO THE SFC LOW THAT WILL BE GOING ACROSS NRN MN. STILL...GIVEN THE STRENGTH OF THE FRONT/FORCING...ODDS LOOK BETTER THAT MSP WILL SEE SOME TSRA ACTIVITY THAN STORMS MISSING THE AIRPORT. /OUTLOOK FOR KMSP/ MON...MVFR/TSRA ENDING EARLY. VFR BY AFTERNOON WINDS WNW 5-10 KTS. TUE...VFR. WINDS WSW 5-10 KTS. WED...VFR. CHC MVFR/TSRA LATE. WINDS S 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...JLT LONG TERM...JPC AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
850 PM CDT MON SEP 1 2014 .UPDATE... TONIGHT WILL BE QUIET AS CONVECTION FROM EARLIER SURGE OF MOISTURE MOVING TO THE N HAS WINDED DOWN. PWATS HAVE CLIMBED TO ~2.1-2.2 INCHES IN REGIONAL SOUNDINGS/BLENDED SATELLITE TOTALS AND SOME OF THESE HIGHER CLOUDS COULD LINGER INTO THE EVENING. LEFT ONLY WORDING OF SOME SHOWERS IN THE FAR SW BUT ENDING BY 02Z. EXPECTING CLOUDS TO LINGER IN THE AREA BUT SLOWLY DISSIPATE IN THE S/SW AS THE RUC/HRRR INDICATE SOME MID LEVEL DRYING. AREAS THAT RECEIVED RAINFALL COULD HAVE SOME PATCHY DENSE FOG...ESPECIALLY IN THE S/SE NEAR MCB/HBG...BUT NOT EXPECTING IT TO BE WIDESPREAD ENOUGH TO MENTION IN WX GRIDS DUE TO WIDESPREAD CLOUDINESS. HRRR DOES INDICATES SOME LOW STRATUS MOVING BACK IN AFTER 06Z TUESDAY AND ADJUSTED SKY GRIDS ACCORDINGLY. ADJUSTED LOWS SLIGHTLY UPWARD ACROSS THE AREA DUE TO LINGERING CLOUDS. TWEAKED HOURLY TEMPS/DEWPOINTS TO CURRENT TRENDS. REST OF THE FORECAST IS ON TRACK. /DC/ && .AVIATION...LATE TONIGHT ANTICIPATE WIDESPREAD MVFR TO LOCALLY IFR CONDITIONS TO DEVELOP BY DAYBREAK TUESDAY. POTENTIAL FOR LOCALLY DENSE FOG AND/OR IFR FLIGHT CATS IS HIGHEST AT PIB/HBG AREA OF THE PINE BELT. FLIGHT CATS WILL IMPROVE THROUGH THE MORNING TOMORROW...AS IS TYPICAL...WITH MORE MORE SCATTERED AFTERNOON SHOWERS AND STORMS ANTICIPATED LATER TUESDAY. /BB/EC/ && .PREV DISCUSSION... /ISSUED 330 PM CDT MON SEP 1 2014/ SHORT TERM...THE MORNING SOUNDINGS SHOWED DRIER AIR ALOFT OVER THE CWA BUT THE BLENDED TOTAL PRECIPITABLE WATER PRODUCT SHOWS TWO INCH PWS SURGING BACK NORTH OVER THE SOUTHWEST TWO THIRDS OF OUR CWA. THIS INCREASE IN DEEP MOISTURE WAS COMBINING WITH TEMPERATURES IN THE LOW TO MID 90S TO DEVELOP A LITTLE GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. HAVE INCREASED POPS THIS AFTERNOON ACROSS MUCH OF THE AREA ALTHOUGH ISOLATED COVERAGE IS STILL EXPECTED IN THE NORTHEAST. CONVECTION WILL DISSIPATE EARLY THIS EVENING. OVERNIGHT TEMPERATURES WILL AGAIN BOTTOM OUT A LITTLE ABOVE NORMAL...IN THE MID 70S AT MOST SITES. A WEAK SURFACE RIDGE WILL NOSE ACROSS THE OUR CWA FROM THE EAST THROUGH WEDNESDAY WHILE A RATHER FLAT MID LEVEL RIDGE RESIDES OVERHEAD. THIS WILL RESULT IN A PERSISTENCE FORECAST FOR THE SHORT TERM WITH WARMER THAN NORMAL TEMPERATURES THROUGH THE PERIOD. BY TUESDAY PWS WILL BE BACK AT OR ABOVE TWO INCHES AREAWIDE. IN THE ABSENCE OF SIGNIFICANT MORNING CLOUDINESS...TEMPERATURES WILL WARM UP RAPIDLY. THE WARM TEMPERATURES WILL COMBINE WITH THE MOIST AIRMASS FOR SCATTERED COVERAGE OF AFTERNOON AND EVENING STORMS. IT WILL BE HARD TO RULE OUT A STRONG THUNDERSTORM OR TWO BUT OVERALL...PARAMETERS DO NOT LOOK THAT FAVORABLE FOR WET MICROBURSTS THE NEXT TWO AFTERNOONS. /22/ LONG TERM...THURSDAY THROUGH SUNDAY...GFS/ECMWF IN AGREEMENT THIS PERIOD IN THAT PATTERN OVER THE LOWER CONUS WILL BE DOMINATED BY FLAT RELATIVELY WEAK DEEP LAYERED RIDGE. AS MID/UPPER RIDGE AXIS LOOKS TO REMAIN ANCHORED OVER NORTH MS...FLOW OVER THE AREA WILL REMAIN EASTERLY AND AFFECTED BY ANY WAVES MOVING ALONG THE GULF COAST. LOW LEVEL FLOW WILL REMAIN SOUTHERLY AS WELL SERVING TO KEEP MOISTURE PLENTIFUL WITH PW/S REMAINING AROUND 2 INCHES. HARD TO FIND ANY SIGNIFICANT WAVES IN THE FLOW DURING THIS PERIOD. WHILE THE LOWER LEVELS LOOK TO BENEFIT MOST FROM THE WARMING FROM THE RIDGE...MID/UPPER LEVEL TEMPS REMAIN SOMEWHAT COOL (NEAR -10C AT H5) ALLOWING FOR AFTERNOON VERTICAL TOTALS IN THE MID 20S. BELIEVE ISOLATED/SCATTERED CONVECTION WILL DOMINATE EACH AFTERNOON/EVENING...MOST NUMEROUS IN THE SOUTH. SEA BREEZE ACTIVITY LOOKS TO ENHANCE CONVECTION OVER THE SOUTH...BUT WEAK ONSHORE FLOW SHOULD LIMIT ITS NORTHWARD EXTENT EACH DAY. A WEAK FRONTAL BOUNDARY LOOKS TO DIP INTO NORTHERN MS ON SUNDAY SERVING TO INCREASE CONVECTIVE POTENTIAL OVER THE NORTH BY THAT TIME./26/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 74 94 73 95 / 12 39 23 31 MERIDIAN 73 94 71 95 / 9 28 24 29 VICKSBURG 74 94 72 94 / 12 43 20 30 HATTIESBURG 74 95 75 96 / 12 33 24 33 NATCHEZ 74 92 74 93 / 13 44 22 30 GREENVILLE 75 93 73 95 / 9 41 19 30 GREENWOOD 74 94 73 95 / 7 41 24 35 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ DC/BB/EC/22/26
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
357 PM CDT Sun Aug 31 2014 .SHORT TERM...(This Evening through Wednesday Afternoon) Issued at 357 PM CDT SUN AUG 31 2014 Afternoon water vapor imagery showing long advertised Pacific trough digging into the central Plains this afternoon...with strong shortwave energy now seen entering western Nebraska. Strengthening wind fields along the southern edge of this feature have advected Mexican Plateau air /i.e. elevated mixed layer/ east across the central/southern Plains as seen on the latest 7.4 micron water vapor GOES sounder channel. Latest RUC analysis shows 7-500 mb lapse rates approaching 9C/km across western Kansas and Nebraska...and fcst models suggest this mid-level airmass will continue tracking east into our region overnight. Along the surface...latest analysis shows a developing leeside low across southeastern Colorado...with a northward extending frontal boundary draped across the Plains which then joins the main area of low pressure now found along the Minnesota/Manitoba border. With time this evening...aforementioned boundary will progress eastward as upstream troughing continues to settle into the central and southern Plains. Airmass ahead of both the cold front and upper wave continues to destabilize with latest SPC meso graphics yielding as much as 3500 joules of MLCAPE between KC and Topeka. Most importantly however...deep layered shear will continue increasing as well as mid- level wind max moves into the area overnight. All said...ingredients appear to be coming together for a fairly active evening and overnight period. Latest radar trends now showing developing cells across north-central Kansas along the previously mentioned frontal boundary. Storms should continue to fire this afternoon before gradually spreading east through the early evening and overnight. As has been advertised in recent days quite well by numerical models...isolated convection to our west and north will likely congeal into a forward propagating MCS this evening just before it enters northwestern Missouri. As this occurs...deep layered shear will continue to strengthen as a low- level jet increases to nearly 50 kts directly overhead. This poses two potential issues for our region: 1) Maintenance of ongoing severe weather as cold pool continues to track southeast with time into northwest Missouri/northeast Kansas 2) Increasing likelihood for developing heavy rain/possible flooding as low-level jet ascends any convectively generated cold pools The above said...main concerns severe-wise for our area will remain strong damaging winds as cold pool for developing MCS tracks south and east with time. Current thinking is damaging wind potential will gradually decrease as storms approach the greater KC area...however cannot rule out strong gusts in and around the metro during the late evening hrs. Additionally...a low-end tornado threat does exist across far northwest Missouri as strong updrafts continue to tilt horizontal vorticity into the vertical along the leading edge of the cold pool as it tracks south and east with time. For now...agree completely with where SPC has the highest tornado threat /NW MO/ as further progress to the south and east will likely result in a less favorable environment due to nocturnal cooling/low-level stabilization effects. In terms of hydro concerns...have elected to go with a flash flood watch for much of northwest MO/northeast Kansas as potential exists for training convection if an outflow boundary lays out across central Missouri. As alluded to above...strength of developing low- level jet is a little concerning especially when PWAT values are expected to increase to anywhere between 2-3 standard deviations above normal as main front approaches. HPC QPF shows a 2+ inch bullseye directly west of KC which appears to be in favor of developing training after midnight. Would rather play it safe hence the current flash flood watch which runs from 2z this evening through 15z Monday morning. Front to slowly settle south of the region during the early morning hrs. Another round of strong to severe storms is possible on Monday...primarly south of the the greater KC area as daytime heating combines with still impressive wind fields aloft. For tomorrow...more optimal timing may support isolated supercell structures as opposed to tonight/s linear activity. Regardless...have maintained likely pops for most areas south of I-70 during the afternoon hrs. Front to clear the area tomorrow night which should support a mostly dry Tuesday. Front slowly expected to lift north as a warm front through the day on Wednesday but minimal impacts expected as no significant features are at play to enhance upward vertical motion. Temps by then should begin to rise with low to mid 90s possible Wednesday afternoon as southerly flow reinvades the area. .LONG TERM...(Wednesday Evening through Sunday) Issued at 357 PM CDT SUN AUG 31 2014 A little bit of everything during the extended portion of the forecast. Storms early Wednesday, followed by a return of hot and humid air until a cold front and more storms on Friday, then finally some fall-like weather over the weekend. Medium range models all on the same page with the overall pattern. Mid-week zonal flow backs to the southwest in response to an upper trough tracking east from the Northern Rockies through the Upper MS Valley by Friday. Elevated convection associated with a northward returning warm front will affect the CWA early Wednesday followed by hot and humid air spreading back into the region. This will likely last into Friday when the southern extension of the Northern Plains upper trough forces a cold front south and through the Mid MO River Valley by Saturday morning. Moderately strong and broad area of high pressure expanding southward will bring some much needed relief from the high humidities. && .AVIATION...(For the 18Z TAFS through 18Z Monday Morning) Issued at 1231 PM CDT SUN AUG 31 2014 VFR conditions this afternoon will give way to increasing chances for showers and storms by evening as a strong storm system moves into the area. Right now...initial shwr/storm activity expected to reach MCI as early as 4z...and STJ as early as 3z. As this moves in...strong wind gusts may create SQ conditions before strong convective outflow moves east of area terminals. Shwrs/storms likely to continue through a good portion of the overnight as low-level jet increases...and storms continuously redevelop along and north of thunderstorm outflow. Additional showers and storms possible after 12z...however bulk of activity should be shifting south as main frontal boundary continues to move through the area. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...FLASH FLOOD WATCH from 9 PM CDT this evening through Monday morning FOR KSZ025-102>105. MO...FLASH FLOOD WATCH from 9 PM CDT this evening through Monday morning FOR MOZ001>005-011>014-020>022-028>030. && $$ SHORT TERM...32 LONG TERM...MJ AVIATION...32
AREA FORECAST DISCUSSION
NWS BILLINGS MT
901 AM MDT SUN AUG 31 2014 .UPDATE... MINOR UPDATES TO THE FORECAST THIS MORNING...MAINLY TO SLIGHTLY ADJUST HIGH TEMPERATURES UPWARD FOR THIS AFTERNOON. MAIN WAVE IS TRACKING FARTHER SOUTH THAN ANTICIPATED...WHICH IS KEEPING RAIN SHOWER ACTIVITY SUPPRESSED TO THE SOUTH ACROSS WYOMING THIS MORNING. THUS EXPECT TEMPERATURES WILL BE ABLE TO RISE BETTER THAN EXPECTED WITH THE LACK OF PRECIPITATION. STILL ANTICIPATE SOME INSTABILITY SHOWERS TO DEVELOP BY THIS AFTERNOON...BUT THE ACTIVITY WILL BE FAIRLY SCATTERED. CHURCH && .SHORT TERM...VALID FOR TDY AND MON... BROAD CYCLONIC FLOW WILL CONTINUE TO PREVAIL OVER OUR REGION THE NEXT COUPLE OF DAYS. WE WILL HAVE A COUPLE OF DISTURBANCES WITHIN THE FLOW ALOFT TRACK THROUGH THE REGION PRODUCING PERIODS OF SHOWERS AND SCATTERED THUNDERSHOWERS. A SEASONABLY COOL AIR MASS WILL REMAIN ENTRENCHED OVER THE REGION AS WELL KEEPING HIGHS ABOUT 10 DEGREES COOLER THAN NORMAL. AS FOR ADJUSTMENTS IN THIS PACKAGE...JET MAX ON THE FRONT END OF BROADER TROUGH IS WEAKER THAN THE ONE ON THE BACKSIDE WHICH SHOULD KEEP SOME OF THE ENERGY DIGGING SOUTH EARLY TODAY. THIS WILL KEEP THE BEST LIFT GENERALLY SOUTH IN NW WYOMING. ONLY THE RAP HAS PICKED UP ON THIS SO FAR WITH THE GFS/WRF/ECMWF ALL OVERPLAYING THE PRECIPITATION TOO FAR NORTH. HOWEVER...WE WILL SEE INSTABILITY SHOWERS DEVELOP AS THE COLD POOL MOVES OVER US THIS AFTERNOON. WE MAY SEE A BETTER CHANCE OF PRECIPITATION ON THIS SIDE OF THE STATELINE BY AFTERNOON AS JET STREAM BUCKLES NORTH WITH EASTWARD MOVEMENT OF UPPER TROUGH AXIS. SO HAVE ADJUSTED HIGHEST POPS SOUTHWARD THIS MORNING...AND HIT THE SE SECTION HARDEST LATE MORNING TO THIS AFTERNOON. ANOTHER SHORT WAVE COMES THROUGH THIS EVENING AND AFFECTS MAINLY OUR WESTERN TERRAIN BEFORE SPREADING SHOWERS TO THE SOUTHEAST THROUGH MONDAY. TEMPERATURES WILL REMAIN ON THE COOL SIDE WITH LITTLE CHANGE TO INHERITED FORECASTS. BT .LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT... RELATIVELY MINOR CHANGES TO THE EXTENDED PERIOD THIS MORNING. ALTHOUGH MODELS ARE IN GOOD AGREEMENT WITH REGARD TO THE OVERALL PATTERN...TIMING REMAINS A BIT OF AN ISSUE...AND LITTLE HAS CHANGES FROM PREVIOUS MODELS RUNS. THE TIMING PROBLEMS HAVE NECESSITATED A MORE BROAD BRUSH APPROACH TO POPS THROUGHOUT THE PERIOD. THE EXTENDED FORECAST REMAINS CONSISTENT...STARTING OFF QUIET FOR WEDNESDAY...WITH ZONAL DOWNSLOPE FLOW ACROSS THE AREA. CONDITIONS BEGIN TO CHANGE LATE WEDNESDAY AS SYSTEM OVER WESTERN CANADA DIGS SOUTH AND FLOW TURNS SOUTHWEST OVER MONTANA. A COLD FRONT ALSO PUSHES INTO THE REGION WEDNESDAY INCREASING THE CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS. HAVE EXPANDED POPS COVERAGE WEDNESDAY EVENING/NIGHT. BROAD TROF REMAINS IN CONTROL OVER THE REGION INTO NEXT WEEKEND...WHICH KEEPS KEEPS SLIGHT PRECIP POTENTIAL IN PLACE THROUGHOUT THE PERIOD AS WELL. PERSISTENCE OF TROF WILL KEEP DAYTIME TEMPS WELL BELOW SEASONAL AVERAGE THROUGHOUT THE EXTENDED PERIOD...WITH 60S AND 70S THROUGHOUT THE PERIOD. AAG && .AVIATION... SCATTERED SHOWERS ARE EXPECTED ACROSS MUCH OF THE REGION TODAY AS ANOTHER DISTURBANCE CROSSES THE AREA. VFR CONDITIONS WILL PREVAIL WITH LOCAL MVFR AND OCCASIONAL MOUNTAIN OBSCURATIONS NEAR SHOWER ACTIVITY. CHAMBERS && .PRELIMINARY POINT TEMP/POPS... TDY MON TUE WED THU FRI SAT ------------------------------------------------------- BIL 071 051/070 050/078 054/077 050/069 049/069 050/074 3/T 32/T 00/U 12/T 22/T 22/T 22/T LVM 068 044/070 043/079 046/077 043/068 044/069 045/076 3/T 42/T 00/U 12/T 22/T 22/T 23/T HDN 072 051/072 050/080 053/081 051/072 051/073 050/077 2/T 32/T 00/U 12/T 22/T 22/T 22/T MLS 074 052/074 052/079 054/080 053/071 053/072 052/075 2/T 12/T 00/U 11/U 12/T 22/T 22/T 4BQ 071 051/071 051/080 053/083 052/072 051/073 051/076 4/T 23/T 00/U 12/T 22/T 22/T 22/T BHK 072 050/072 048/077 051/080 050/073 049/070 049/073 4/T 12/T 00/U 12/T 22/T 22/T 22/T SHR 068 047/069 046/080 050/083 049/073 048/075 048/078 5/T 33/T 00/U 12/T 22/T 22/T 23/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
330 AM MDT SUN AUG 31 2014 .SHORT TERM...VALID FOR TDY AND MON... BROAD CYCLONIC FLOW WILL CONTINUE TO PREVAIL OVER OUR REGION THE NEXT COUPLE OF DAYS. WE WILL HAVE A COUPLE OF DISTURBANCES WITHIN THE FLOW ALOFT TRACK THROUGH THE REGION PRODUCING PERIODS OF SHOWERS AND SCATTERED THUNDERSHOWERS. A SEASONABLY COOL AIR MASS WILL REMAIN ENTRENCHED OVER THE REGION AS WELL KEEPING HIGHS ABOUT 10 DEGREES COOLER THAN NORMAL. AS FOR ADJUSTMENTS IN THIS PACKAGE...JET MAX ON THE FRONT END OF BROADER TROUGH IS WEAKER THAN THE ONE ON THE BACKSIDE WHICH SHOULD KEEP SOME OF THE ENERGY DIGGING SOUTH EARLY TODAY. THIS WILL KEEP THE BEST LIFT GENERALLY SOUTH IN NW WYOMING. ONLY THE RAP AND HRRR HAS PICKED UP ON THIS SO FAR WITH THE GFS/WRF/ECMWF ALL OVERPLAYING THE PRECIPITATION TOO FAR NORTH. HOWEVER...WE WILL SEE INSTABILITY SHOWERS DEVELOP AS THE COLD POOL MOVES OVER THE WEST THIS AFTERNOON. WE MAY SEE A BETTER CHANCE OF PRECIPITATION ON THIS SIDE OF THE STATELINE BY AFTERNOON AS ENERGY TURNS NORTHEAST ON TROUGHS FRONT SIDE. SO HAVE ADJUSTED HIGHEST POPS SOUTHWARD THIS MORNING...AND HIT THE SE SECTION HARDEST LATE MORNING TO THIS AFTERNOON. ANOTHER SHORT WAVE COMES THROUGH THIS EVENING AND AFFECTS MAINLY OUR WESTERN TERRAIN BEFORE SPREADING SHOWERS TO THE SOUTHEAST THROUGH MONDAY. TEMPERATURES WILL REMAIN ON THE COOL SIDE WITH LITTLE CHANGE TO INHERITED FORECASTS. BT .LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT... RELATIVELY MINOR CHANGES TO THE EXTENDED PERIOD THIS MORNING. ALTHOUGH MODELS ARE IN GOOD AGREEMENT WITH REGARD TO THE OVERALL PATTERN...TIMING REMAINS A BIT OF AN ISSUE...AND LITTLE HAS CHANGES FROM PREVIOUS MODELS RUNS. THE TIMING PROBLEMS HAVE NECESSITATED A MORE BROAD BRUSH APPROACH TO POPS THROUGHOUT THE PERIOD. THE EXTENDED FORECAST REMAINS CONSISTENT...STARTING OFF QUIET FOR WEDNESDAY...WITH ZONAL DOWNSLOPE FLOW ACROSS THE AREA. CONDITIONS BEGIN TO CHANGE LATE WEDNESDAY AS SYSTEM OVER WESTERN CANADA DIGS SOUTH AND FLOW TURNS SOUTHWEST OVER MONTANA. A COLD FRONT ALSO PUSHES INTO THE REGION WEDNESDAY INCREASING THE CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS. HAVE EXPANDED POPS COVERAGE WEDNESDAY EVENING/NIGHT. BROAD TROF REMAINS IN CONTROL OVER THE REGION INTO NEXT WEEKEND...WHICH KEEPS KEEPS SLIGHT PRECIP POTENTIAL IN PLACE THROUGHOUT THE PERIOD AS WELL. PERSISTENCE OF TROF WILL KEEP DAYTIME TEMPS WELL BELOW SEASONAL AVERAGE THROUGHOUT THE EXTENDED PERIOD...WITH 60S AND 70S THROUGHOUT THE PERIOD. AAG && .AVIATION... SCATTERED SHOWERS ARE EXPECTED ACROSS MUCH OF THE REGION TODAY AS ANOTHER DISTURBANCE CROSSES THE AREA. AREAS OF MVFR AND FREQUENT MOUNTAIN OBSCURATIONS CAN BE EXPECTED THROUGHOUT THE DAY. AAG && .PRELIMINARY POINT TEMP/POPS... TDY MON TUE WED THU FRI SAT ------------------------------------------------------- BIL 069 051/070 050/078 054/077 050/069 049/069 050/074 3/T 32/T 00/U 12/T 22/T 22/T 22/T LVM 066 044/070 043/079 046/077 043/068 044/069 045/076 4/T 42/T 00/U 12/T 22/T 22/T 23/T HDN 071 051/072 050/080 053/081 051/072 051/073 050/077 3/T 32/T 00/U 12/T 22/T 22/T 22/T MLS 074 052/074 052/079 054/080 053/071 053/072 052/075 2/T 22/T 00/U 11/U 12/T 22/T 22/T 4BQ 070 051/071 051/080 053/083 052/072 051/073 051/076 4/T 23/T 00/U 12/T 22/T 22/T 22/T BHK 072 050/072 048/077 051/080 050/073 049/070 049/073 4/T 12/T 00/U 12/T 22/T 22/T 22/T SHR 066 047/069 046/080 050/083 049/073 048/075 048/078 5/T 33/T 00/U 12/T 22/T 22/T 23/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1206 PM EDT SUN AUG 31 2014 .SYNOPSIS... A SLOW MOVING TROUGH OF LOW PRESSURE WILL PRODUCE SHOWERS AND A FEW THUNDERSTORMS TODAY BEFORE SLOWLY TAPERING OFF FROM NORTHWEST TO SOUTHEAST THIS AFTERNOON. IT WILL REMAIN MUGGY ALTHOUGH EXTENSIVE CLOUD COVER WILL KEEP TEMPERATURES LOWER THAN YESTERDAY. A FEW SPOTTY SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON LABOR DAY...BUT THE MAJORITY OF THE DAY SHOULD BE RAIN FREE WITH TEMPERATURES WARMING BACK TO A LITTLE ABOVE AVERAGE. && .NEAR TERM /THROUGH TONIGHT/... RADAR IMAGERY LATE THIS MORNING SHOWS A SOLID AREA OF RAIN ACROSS CENTRAL NEW YORK...JUST ABOUT TO EXIT EAST OF OUR CWA. BEHIND THIS...BROKEN LINES OF SHOWERS WITH EMBEDDED THUNDERSTORMS HAVE DEVELOPED AHEAD OF A WIND SHIFT BOUNDARY WHICH EXTENDS FROM SW-NE AND IS LOCATED NEAR BUFFALO AT 1100 AM. THIS BOUNDARY WILL CONTINUE TO MOVE EAST IN ASSOCIATION WITH A MID LEVEL TROUGH. THE 12Z BUF SOUNDING HAS AN IMPRESSIVE 1.83 INCH PWAT...SO SHOWERS AND THUNDERSTORMS WHICH DO DEVELOP AHEAD OF THIS BOUNDARY WILL PRODUCE BRIEF HEAVY DOWNPOURS. FOR THE MOST PART...THE PROGRESSIVE NATURE OF THE BOUNDARY WILL MITIGATE FLOOD POTENTIAL...HOWEVER A DEVELOPING AREA OF HEAVY RAIN SHOWERS ACROSS LAKE ERIE MAY HAVE THE POTENTIAL TO PRODUCE LOCALIZED FLOODING IN CHAUTAUQUA COUNTY THROUGH MID AFTERNOON. IT IS STILL FAIRLY MOIST BEHIND THIS BOUNDARY...AND WITH A LAKE BREEZE CONVERGENCE BOUNDARY EXPECTED TO DEVELOP NEAR THE SOUTH SHORES OF LAKE ONTARIO THERE COULD BE A FEW SHOWERS OR THUNDERSTORMS WHICH DEVELOP ON THIS BOUNDARY. HOWEVER...MOST MESOSCALE GUIDANCE FROM THE HRRR TO NAM/RGEM FOCUS THE STEADIEST SHOWERS ACROSS EAST OF EACH LAKE...OUT AHEAD OF THE BOUNDARY. SOUTHWESTERLY WINDS WILL PICK UP ACROSS THE NIAGARA FRONTIER THIS AFTERNOON...WHICH SHOULD PROVIDE AT LEAST A PARTIAL CLEARING BY MIXING OUT LOW MOISTURE. TEMPERATURES ALOFT ARE STILL WARM...WITH SURFACE TEMPERATURES LIKELY TO REACH 80 IN ANY AREAS WHICH GET PROLONGED SUNSHINE. SOUTHERN AND EASTERN PORTIONS OF THE CWA SHOULD STAY STUCK IN THE CLOUDS...WITH HIGHS AVERAGING IN THE MID 70S. TONIGHT SHOWERS ACROSS THE SOUTHERN TIER AND CENTRAL NY WILL CONTINUE TO SLOWLY DIMINISH. ENOUGH INSTABILITY MAY DEVELOP IN THE WAKE OF THIS MAIN RAIN AREA TO ALLOW SCATTERED THUNDERSTORMS TO FORM DURING THE LATE AFTERNOON AND EARLY EVENING ACROSS THE NIAGARA PENINSULA. IF THEY MATERIALIZE...A FEW MAY MAKE IT INTO AREAS JUST NORTH OF BUFFALO THIS EVENING. SCATTERED STORMS MAY ALSO FORM OVER SOUTHEAST ONTARIO AND CROSS THE SAINT LAWRENCE INTO THE NORTH COUNTRY THIS EVENING. OTHERWISE EXPECT SOME PARTIAL CLEARING OVERNIGHT ON THE LAKE PLAINS. ACROSS THE HIGHER TERRAIN LOW LEVEL MOISTURE AND WEAK UPSLOPE FLOW AND CONVERGENCE WILL LIKELY SUPPORT EXPANDING LOW CLOUD COVER. EXPECT LOWS IN THE MID TO UPPER 60S ON THE LAKE PLAINS AND LOWER TO MID 60S IN THE SOUTHERN TIER AND NORTH COUNTRY. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... A WARM AND STICKY AIRMASS WILL REMAIN ACROSS THE REGION ON MONDAY...WITH MOST OF THE FORECAST AREA EXPERIENCING MAINLY DRY CONDITIONS. HOWEVER THERE WILL BE THE CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON AND EVENING...MAINLY ACROSS THE INTERIOR SOUTHERN TIER WHERE THE BEST INSTABILITY WILL RESIDE. CAPE VALUES BY LATER IN THE AFTERNOON ACROSS THIS REGION WILL RUN IN THE 1000-1500 J/KG RANGE WITH LI`S POSSIBLY AS LOW AS -4. HOWEVER WITH WEAK 0-6KM BULK SHEAR (~20KTS) AND LACK OF A GOOD SURFACE TRIGGER (ASIDE FROM A POSSIBLE LAKE BREEZE)...NOT EXPECTING ANY THUNDERSTORMS TO REACH SEVERE LIMITS. INSTABILITY LOOKS LOWER ACROSS THE REMAINDER OF THE AREA...AND THUS CONVECTIVE CHANCES LOOK MUCH LOWER AS WELL. TEMPERATURES WILL AGAIN BE ON THE WARM SIDE WITH HIGHS IN THE UPPER 70S TO LOWER 80S. WITH THE LOSS OF DAYTIME HEATING MONDAY NIGHT MOST OF THE DIURNALLY DRIVEN CONVECTION WILL DIMINISH IN COVERAGE...ALTHOUGH A FEW STORMS MAY CONTINUE LATE INTO THE EVENING...ESPECIALLY ACROSS PORTIONS OF THE SOUTHERN TIER. AT THE SAME TIME A COLD FRONT OVER THE UPPER GREAT LAKES WILL BE ADVANCING TOWARD THE REGION AND BE LOCATED WEST OF NEW YORK STATE BY TUESDAY MORNING. THAT SAID...MOST OF THE NIGHT LOOKS TO REMAIN DRY...WITH PRECIP CHANCES STARTING TO INCREASE A BIT ACROSS WESTERN NEW YORK TOWARD TUESDAY MORNING. ANOTHER MILD NIGHT CAN BE EXPECTED WITH LOWS IN THE MID TO UPPER 60S FOR MOST LOCATIONS THANKS TO DEEP SOUTHERLY FLOW OUT AHEAD OF THE APPROACHING COLD FRONT. LATEST GUIDANCE PACKAGE HAS THE COLD FRONT NOW MOVING A BIT SLOWER THAN IN PREVIOUS RUNS. THIS IS MOST LIKELY DUE TO MOST OF THE MODELS NOW COMING INTO AGREEMENT ON THE DEVELOPMENT OF LOW PRESSURE SOMEWHERE IN THE OHIO VALLEY ALONG THE FRONT AND THEN TRACKING IT NORTHEAST ALONG THE BOUNDARY WHICH WOULD SLOW IT DOWN A LITTLE. THAT SAID...IT NOW APPEARS IT WILL TAKE THE BULK OF THE DAY TUESDAY FOR THE COLD FRONT TO SWEEP ACROSS THE REGION WITH SHOWERS AN THUNDERSTORMS LIKELY...WITH LOWER CHANCE POPS BY LATER IN THE DAY ACROSS WESTERN NEW YORK. HIGH PRECIPITABLE WATER VALUES OF 1.7"-1.9" TUESDAY AFTERNOON OFFER THE RISK OF HEAVY DOWNPOURS WITH ANY THUNDERSTORM. SBCAPES OVER 1000 J/KG COMBINED WITH LIFTED INDEX VALUES AT -4C TO -5C ALSO POINT TO THE POSSIBILITY OF STORMS. THE MAIN DIFFERENCES FROM MONDAY ARE THAT 0-6KM BULK SHEAR VALUES LOOK TO BE IN THE 40-45KT RANGE...AND ALSO HAVE THE SURFACE COLD FRONT CROSSING THE FORECAST AREA WHICH WILL SERVE AS THE FOCAL POINT FOR STORMS TO FIRE ALONG. ALL THIS SAID...LOOKS AS THOUGH THERE COULD BE SOME STRONG STORMS...WITH A FEW STORMS POSSIBLY REACHING SEVERE LIMITS. MAIN THREATS APPEAR TO BE GUSTY WINDS ASSOCIATED WITH BOWING LINE SEGMENTS AND MARGINALLY SEVERE HAIL. ANOTHER WARM DAY ON TAP WITH HIGHS IN THE UPPER 70S TO LOWER 80S. THE COLD FRONT WILL SLIDE SOUTH AND EAST OF THE FORECAST AREA TUESDAY EVENING...TAKING THE SHOWERS AND STORMS WITH IT. ALTHOUGH A FEW SHOWERS WILL STILL BE POSSIBLE DURING THE EVENING ACROSS EASTERN AREAS...BUT EVEN HERE THINGS WILL DRY OUT LATER TUESDAY NIGHT AS SURFACE HIGH PRESSURE STARTS TO BUILD EAST ACROSS NEW YORK STATE. LOWS WILL BE GENERALLY IN THE UPPER 50S TO LOWER 60S. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BUILD ACROSS THE REGION WEDNESDAY AND THURSDAY BRINGING IN DRIER AIR AND TEMPERATURES THAT WILL STILL AVERAGE AT OR JUST A BIT ABOVE NORMAL FOR EARLY SEPTEMBER. HIGH PRESSURE WILL THEN SLIDE OFF THE NEW ENGLAND COAST BY FRIDAY. THIS WILL PROVIDE MAINLY DRY CONDITIONS THROUGH MIDWEEK...BEFORE THE NEXT FRONTAL SYSTEM APPROACHES FOR LATE IN THE WEEK AND EARLY WEEKEND. TEMPERATURES WILL BE A BIT ABOVE SEASONAL NORMALS WITH HIGHS IN THE UPPER 70S TO LOW 80S AND LOWS IN THE LOWER 60S. && .AVIATION /16Z SUNDAY THROUGH THURSDAY/... CONDITIONS HAVE LOWERED LATE THIS MORNING...WITH THE APPROACH OF A SURFACE TROUGH AN IN HEAVIER RAIN SHOWERS. LOW VSBY IN RAIN SHOWERS...AND A FEW EMBEDDED THUNDERSTORMS SHOULD BE TEMPORARY. EXPECT A MIX OF MVFR/VFR CIGS AT BUF/IAG/ROC/ART WITH THE SW WIND SHIFT...WHILE JHW IS LIKELY TO REMAIN IFR OR LOWER AND THEN IMPROVE WITH THE WIND SHIFT. TONIGHT ANY SHOWERS AND SCATTERED THUNDER ACROSS THE SOUTHERN TIER WILL DIMINISH DURING THE EVENING. MAINLY VFR DURING THE EVENING WILL GIVE WAY TO INCREASING AMOUNTS OF IFR IN LOW STRATUS OVERNIGHT WITH EXTENSIVE LOW LEVEL MOISTURE FIELDS. EXPECT STRATUS TO FORM FIRST ACROSS HIGHER TERRAIN...BUT MAY SPREAD TO THE LOWER ELEVATIONS OF WESTERN NY AS WELL AFTER ABOUT 09Z. AREAS OF FOG AND IFR VSBY ARE LIKELY ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER AND FINGER LAKES AS WELL WHERE THE LOW STRATUS INTERSECTS THE HILLS. OUTLOOK... MONDAY...VFR/MVFR IN SCATTERED SHOWERS AND THUNDERSTORMS. TUESDAY...SHOWERS AND THUNDERSTORMS LIKELY WITH ASSOCIATED BRIEF MVFR/IFR. SOME STORMS MAY BE STRONG. WEDNESDAY AND THURSDAY...VFR. && .MARINE... MODERATE SOUTHERLIES WILL CONTINUE TO PRODUCE MARGINAL SMALL CRAFT ADVISORY CONDITIONS AT THE NORTHEAST END OF LAKE ONTARIO FROM GALLOO ISLAND TO CAPE VINCENT THROUGH EARLY AFTERNOON BEFORE DIMINISHING. LOW PRESSURE WILL MOVE ACROSS SOUTHERN QUEBEC TODAY WITH WINDS BECOMING MORE SOUTHWEST ON THE LOWER LAKES. EXPECT WINDS TO INCREASE ABRUPTLY ON LAKE ERIE THROUGH EARLY AFTERNOON...WITH A 3 TO 6 HOUR PERIOD OF 15 TO 20 KNOT WINDS AND 3 TO 5 FOOT WAVES AS WINDS ALOFT SHIFT TO THE WSW AND MIX DOWN AS THEY ENCOUNTER THE CHAUTAUQUA RIDGE. ALSO...THERE IS A CONVERGENCE BOUNDARY ON LAKE ERIE WHICH HAS THE POTENTIAL TO PRODUCE WATER SPOUTS THROUGH EARLY AFTERNOON. THIS POTENTIAL WILL END AS THE BOUNDARY SLIDES FURTHER SOUTH AND OFF THE LAKE. THE PRESSURE GRADIENT RELAXES ACROSS THE LOWER LAKES TONIGHT AS LOW PRESSURE DISSIPATES OVER SOUTHEAST QUEBEC. THIS WILL ALLOW WINDS AND WAVES TO SUBSIDE. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LEZ040- 041. SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LOZ045. && $$ SYNOPSIS...HITCHCOCK NEAR TERM...APFFEL/HITCHCOCK SHORT TERM...JM LONG TERM...JM/WCH AVIATION...APFFEL/HITCHCOCK MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1112 AM EDT SUN AUG 31 2014 .SYNOPSIS... A SLOW MOVING TROUGH OF LOW PRESSURE WILL PRODUCE SHOWERS AND A FEW THUNDERSTORMS TODAY BEFORE SLOWLY TAPERING OFF FROM NORTHWEST TO SOUTHEAST THIS AFTERNOON. IT WILL REMAIN MUGGY ALTHOUGH EXTENSIVE CLOUD COVER WILL KEEP TEMPERATURES LOWER THAN YESTERDAY. A FEW SPOTTY SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON LABOR DAY...BUT THE MAJORITY OF THE DAY SHOULD BE RAIN FREE WITH TEMPERATURES WARMING BACK TO A LITTLE ABOVE AVERAGE. && .NEAR TERM /THROUGH TONIGHT/... RADAR IMAGERY LATE THIS MORNING SHOWS A SOLID AREA OF RAIN ACROSS CENTRAL NEW YORK...JUST ABOUT TO EXIT EAST OF OUR CWA. BEHIND THIS...BROKEN LINES OF SHOWERS WITH EMBEDDED THUNDERSTORMS HAVE DEVELOPED AHEAD OF A WIND SHIFT BOUNDARY WHICH EXTENDS FROM SW-NE AND IS LOCATED NEAR BUFFALO AT 1100 AM. THIS BOUNDARY WILL CONTINUE TO MOVE EAST IN ASSOCIATION WITH A MID LEVEL TROUGH. THE 12Z BUF SOUNDING HAS AN IMPRESSIVE 1.83 INCH PWAT...SO SHOWERS AND THUNDERSTORMS WHICH DO DEVELOP AHEAD OF THIS BOUNDARY WILL PRODUCE BRIEF HEAVY DOWNPOURS...BUT ARE LIKELY TO MOVE WITH THE BOUNDARY WHICH SHOULD MITIGATE FLOOD POTENTIAL. IT IS STILL FAIRLY MOIST BEHIND THIS BOUNDARY...AND WITH A LAKE BREEZE CONVERGENCE BOUNDARY EXPECTED TO DEVELOP NEAR THE SOUTH SHORES OF LAKE ONTARIO THERE COULD BE A FEW SHOWERS OR THUNDERSTORMS WHICH DEVELOP ON THIS BOUNDARY. HOWEVER...MOST MESOSCALE GUIDANCE FROM THE HRRR TO NAM/RGEM FOCUS THE STEADIEST SHOWERS ACROSS EAST OF EACH LAKE...OUT AHEAD OF THE BOUNDARY. SOUTHWESTERLY WINDS WILL PICK UP ACROSS THE NIAGARA FRONTIER THIS AFTERNOON...WHICH SHOULD PROVIDE AT LEAST A PARTIAL CLEARING BY MIXING OUT LOW MOISTURE. TEMPERATURES ALOFT ARE STILL WARM...WITH SURFACE TEMPERATURES LIKELY TO REACH 80 IN ANY AREAS WHICH GET PROLONGED SUNSHINE. SOUTHERN AND EASTERN PORTIONS OF THE CWA SHOULD STAY STUCK IN THE CLOUDS...WITH HIGHS AVERAGING IN THE MID 70S. TONIGHT SHOWERS ACROSS THE SOUTHERN TIER AND CENTRAL NY WILL CONTINUE TO SLOWLY DIMINISH. ENOUGH INSTABILITY MAY DEVELOP IN THE WAKE OF THIS MAIN RAIN AREA TO ALLOW SCATTERED THUNDERSTORMS TO FORM DURING THE LATE AFTERNOON AND EARLY EVENING ACROSS THE NIAGARA PENINSULA. IF THEY MATERIALIZE...A FEW MAY MAKE IT INTO AREAS JUST NORTH OF BUFFALO THIS EVENING. SCATTERED STORMS MAY ALSO FORM OVER SOUTHEAST ONTARIO AND CROSS THE SAINT LAWRENCE INTO THE NORTH COUNTRY THIS EVENING. OTHERWISE EXPECT SOME PARTIAL CLEARING OVERNIGHT ON THE LAKE PLAINS. ACROSS THE HIGHER TERRAIN LOW LEVEL MOISTURE AND WEAK UPSLOPE FLOW AND CONVERGENCE WILL LIKELY SUPPORT EXPANDING LOW CLOUD COVER. EXPECT LOWS IN THE MID TO UPPER 60S ON THE LAKE PLAINS AND LOWER TO MID 60S IN THE SOUTHERN TIER AND NORTH COUNTRY. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... A WARM AND STICKY AIRMASS WILL REMAIN ACROSS THE REGION ON MONDAY...WITH MOST OF THE FORECAST AREA EXPERIENCING MAINLY DRY CONDITIONS. HOWEVER THERE WILL BE THE CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON AND EVENING...MAINLY ACROSS THE INTERIOR SOUTHERN TIER WHERE THE BEST INSTABILITY WILL RESIDE. CAPE VALUES BY LATER IN THE AFTERNOON ACROSS THIS REGION WILL RUN IN THE 1000-1500 J/KG RANGE WITH LI`S POSSIBLY AS LOW AS -4. HOWEVER WITH WEAK 0-6KM BULK SHEAR (~20KTS) AND LACK OF A GOOD SURFACE TRIGGER (ASIDE FROM A POSSIBLE LAKE BREEZE)...NOT EXPECTING ANY THUNDERSTORMS TO REACH SEVERE LIMITS. INSTABILITY LOOKS LOWER ACROSS THE REMAINDER OF THE AREA...AND THUS CONVECTIVE CHANCES LOOK MUCH LOWER AS WELL. TEMPERATURES WILL AGAIN BE ON THE WARM SIDE WITH HIGHS IN THE UPPER 70S TO LOWER 80S. WITH THE LOSS OF DAYTIME HEATING MONDAY NIGHT MOST OF THE DIURNALLY DRIVEN CONVECTION WILL DIMINISH IN COVERAGE...ALTHOUGH A FEW STORMS MAY CONTINUE LATE INTO THE EVENING...ESPECIALLY ACROSS PORTIONS OF THE SOUTHERN TIER. AT THE SAME TIME A COLD FRONT OVER THE UPPER GREAT LAKES WILL BE ADVANCING TOWARD THE REGION AND BE LOCATED WEST OF NEW YORK STATE BY TUESDAY MORNING. THAT SAID...MOST OF THE NIGHT LOOKS TO REMAIN DRY...WITH PRECIP CHANCES STARTING TO INCREASE A BIT ACROSS WESTERN NEW YORK TOWARD TUESDAY MORNING. ANOTHER MILD NIGHT CAN BE EXPECTED WITH LOWS IN THE MID TO UPPER 60S FOR MOST LOCATIONS THANKS TO DEEP SOUTHERLY FLOW OUT AHEAD OF THE APPROACHING COLD FRONT. LATEST GUIDANCE PACKAGE HAS THE COLD FRONT NOW MOVING A BIT SLOWER THAN IN PREVIOUS RUNS. THIS IS MOST LIKELY DUE TO MOST OF THE MODELS NOW COMING INTO AGREEMENT ON THE DEVELOPMENT OF LOW PRESSURE SOMEWHERE IN THE OHIO VALLEY ALONG THE FRONT AND THEN TRACKING IT NORTHEAST ALONG THE BOUNDARY WHICH WOULD SLOW IT DOWN A LITTLE. THAT SAID...IT NOW APPEARS IT WILL TAKE THE BULK OF THE DAY TUESDAY FOR THE COLD FRONT TO SWEEP ACROSS THE REGION WITH SHOWERS AN THUNDERSTORMS LIKELY...WITH LOWER CHANCE POPS BY LATER IN THE DAY ACROSS WESTERN NEW YORK. HIGH PRECIPITABLE WATER VALUES OF 1.7"-1.9" TUESDAY AFTERNOON OFFER THE RISK OF HEAVY DOWNPOURS WITH ANY THUNDERSTORM. SBCAPES OVER 1000 J/KG COMBINED WITH LIFTED INDEX VALUES AT -4C TO -5C ALSO POINT TO THE POSSIBILITY OF STORMS. THE MAIN DIFFERENCES FROM MONDAY ARE THAT 0-6KM BULK SHEAR VALUES LOOK TO BE IN THE 40-45KT RANGE...AND ALSO HAVE THE SURFACE COLD FRONT CROSSING THE FORECAST AREA WHICH WILL SERVE AS THE FOCAL POINT FOR STORMS TO FIRE ALONG. ALL THIS SAID...LOOKS AS THOUGH THERE COULD BE SOME STRONG STORMS...WITH A FEW STORMS POSSIBLY REACHING SEVERE LIMITS. MAIN THREATS APPEAR TO BE GUSTY WINDS ASSOCIATED WITH BOWING LINE SEGMENTS AND MARGINALLY SEVERE HAIL. ANOTHER WARM DAY ON TAP WITH HIGHS IN THE UPPER 70S TO LOWER 80S. THE COLD FRONT WILL SLIDE SOUTH AND EAST OF THE FORECAST AREA TUESDAY EVENING...TAKING THE SHOWERS AND STORMS WITH IT. ALTHOUGH A FEW SHOWERS WILL STILL BE POSSIBLE DURING THE EVENING ACROSS EASTERN AREAS...BUT EVEN HERE THINGS WILL DRY OUT LATER TUESDAY NIGHT AS SURFACE HIGH PRESSURE STARTS TO BUILD EAST ACROSS NEW YORK STATE. LOWS WILL BE GENERALLY IN THE UPPER 50S TO LOWER 60S. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BUILD ACROSS THE REGION WEDNESDAY AND THURSDAY BRINGING IN DRIER AIR AND TEMPERATURES THAT WILL STILL AVERAGE AT OR JUST A BIT ABOVE NORMAL FOR EARLY SEPTEMBER. HIGH PRESSURE WILL THEN SLIDE OFF THE NEW ENGLAND COAST BY FRIDAY. THIS WILL PROVIDE MAINLY DRY CONDITIONS THROUGH MIDWEEK...BEFORE THE NEXT FRONTAL SYSTEM APPROACHES FOR LATE IN THE WEEK AND EARLY WEEKEND. TEMPERATURES WILL BE A BIT ABOVE SEASONAL NORMALS WITH HIGHS IN THE UPPER 70S TO LOW 80S AND LOWS IN THE LOWER 60S. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... CONDITIONS HAVE LOWERED LATE THIS MORNING...WITH THE APPROACH OF A SURFACE TROUGH AN IN HEAVIER RAIN SHOWERS. LOW VSBY IN RAIN SHOWERS...AND A FEW EMBEDDED THUNDERSTORMS SHOULD BE TEMPORARY. EXPECT A MIX OF MVFR/VFR CIGS AT BUF/IAG/ROC/ART WITH THE SW WIND SHIFT...WHILE JHW IS LIKELY TO REMAIN IFR OR LOWER AND THEN IMPROVE WITH THE WIND SHIFT. TONIGHT ANY SHOWERS AND SCATTERED THUNDER ACROSS THE SOUTHERN TIER WILL DIMINISH DURING THE EVENING. MAINLY VFR DURING THE EVENING WILL GIVE WAY TO INCREASING AMOUNTS OF IFR IN LOW STRATUS OVERNIGHT WITH EXTENSIVE LOW LEVEL MOISTURE FIELDS. EXPECT STRATUS TO FORM FIRST ACROSS HIGHER TERRAIN...BUT MAY SPREAD TO THE LOWER ELEVATIONS OF WESTERN NY AS WELL AFTER ABOUT 09Z. AREAS OF FOG AND IFR VSBY ARE LIKELY ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER AND FINGER LAKES AS WELL WHERE THE LOW STRATUS INTERSECTS THE HILLS. OUTLOOK... MONDAY...VFR/MVFR IN SCATTERED SHOWERS AND THUNDERSTORMS. TUESDAY...SHOWERS AND THUNDERSTORMS LIKELY WITH ASSOCIATED BRIEF MVFR/IFR. SOME STORMS MAY BE STRONG. WEDNESDAY AND THURSDAY...VFR. && .MARINE... MODERATE SOUTHERLIES WILL CONTINUE TO PRODUCE MARGINAL SMALL CRAFT ADVISORY CONDITIONS AT THE NORTHEAST END OF LAKE ONTARIO FROM GALLOO ISLAND TO CAPE VINCENT THROUGH EARLY AFTERNOON BEFORE DIMINISHING. LOW PRESSURE WILL MOVE ACROSS SOUTHERN QUEBEC TODAY WITH WINDS BECOMING MORE SOUTHWEST ON THE LOWER LAKES. EXPECT WINDS TO INCREASE ABRUPTLY ON LAKE ERIE THROUGH EARLY AFTERNOON...WITH A 3 TO 6 HOUR PERIOD OF 15 TO 20 KNOT WINDS AND 3 TO 5 FOOT WAVES AS WINDS ALOFT SHIFT TO THE WSW AND MIX DOWN AS THEY ENCOUNTER THE CHAUTAUQUA RIDGE. ALSO...THERE IS A CONVERGENCE BOUNDARY ON LAKE ERIE WHICH HAS THE POTENTIAL TO PRODUCE WATER SPOUTS THROUGH EARLY AFTERNOON. THIS POTENTIAL WILL END AS THE BOUNDARY SLIDES FURTHER SOUTH AND OFF THE LAKE. THE PRESSURE GRADIENT RELAXES ACROSS THE LOWER LAKES TONIGHT AS LOW PRESSURE DISSIPATES OVER SOUTHEAST QUEBEC. THIS WILL ALLOW WINDS AND WAVES TO SUBSIDE. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LEZ040- 041. SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LOZ045. && $$ SYNOPSIS...HITCHCOCK NEAR TERM...APFFEL/HITCHCOCK SHORT TERM...JM LONG TERM...JM/WCH AVIATION...APFFEL/HITCHCOCK MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
751 AM EDT SUN AUG 31 2014 .SYNOPSIS... A SLOW MOVING TROUGH OF LOW PRESSURE WILL PRODUCE OCCASIONAL SHOWERS AND SCATTERED THUNDERSTORMS ACROSS MUCH OF THE REGION THIS MORNING BEFORE SLOWLY TAPERING OFF FROM NORTHWEST TO SOUTHEAST THIS AFTERNOON. IT WILL REMAIN MUGGY ALTHOUGH EXTENSIVE CLOUD COVER WILL KEEP TEMPERATURES LOWER THAN YESTERDAY. A FEW SPOTTY SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON LABOR DAY...BUT THE MAJORITY OF THE DAY SHOULD BE RAIN FREE WITH TEMPERATURES WARMING BACK TO A LITTLE ABOVE AVERAGE. && .NEAR TERM /THROUGH TONIGHT/... RADAR IMAGERY THIS MORNING SHOWING A SOLID AREA OF LIGHT RAIN COVERING MUCH OF THE REGION...WITH A FEW POCKETS OF MODERATE RAIN ACROSS THE SOUTHERN TIER AND CENTRAL NY. THE WIDESPREAD NATURE OF THE RAIN IS LIKELY DUE TO MID LEVEL DEFORMATION AND FRONTOGENESIS FROM A WEAK BAROCLINIC LEAF NOTED IN IR SATELLITE IMAGERY. THIS STEADY RAIN WILL SHIFT SLOWLY EAST THROUGH THE REGION THROUGH MIDDAY. THE BACK EDGE IS NEAR KERI-KBUF AT 1130Z...AND MUCH OF THE NIAGARA FRONTIER WILL MISS OUT ON THE STEADIER RAIN. THAT SAID... THE BACK EDGE MAY NOT STAY CLEAN WITH MESOSCALE MODEL GUIDANCE SUCH AS THE HRRR SUGGESTING CONVECTIVE SHOWERS WILL DEVELOP BY LATE MORNING ACROSS THE NIAGARA FRONTIER JUST WEST OF THE STEADIER RAIN. FOR TODAY A MID LEVEL TROUGH WILL ADVANCE EAST ACROSS THE CENTRAL GREAT LAKES...WITH DOWNSTREAM HEIGHT FALLS AND DPVA PRODUCED BY CONVECTIVELY AUGMENTED VORTICITY MAXIMA AIDING IN LARGE SCALE ASCENT. UPPER LEVEL DIVERGENCE WILL BE ENHANCED BY THE RIGHT ENTRANCE REGION OF A 80+ KNOT UPPER LEVEL JET STRETCHING FROM LOWER MICHIGAN TO SOUTHERN QUEBEC. A BELT OF 30-35 KNOT FLOW IN THE 900-700MB LAYER WILL AID IN ORGANIZING CONVERGENCE AND MOISTURE TRANSPORT. AT THE SURFACE WEAK/ELONGATED LOW PRESSURE WILL MOVE INTO SOUTHERN QUEBEC WITH A WEAK PRE-FRONTAL TROUGH EASING ACROSS THE LOWER LAKES PROVIDING LOW LEVEL CONVERGENCE. IR SATELLITE IMAGERY SHOWING A WEAK BAROCLINIC LEAF DEVELOPING ACROSS THE OHIO VALLEY EARLY THIS MORNING. AS THIS FEATURE TRANSLATES NORTHEAST TODAY IT WILL ACT TO ENHANCE MID LEVEL FRONTOGENESIS AND DEFORMATION ACROSS OUR REGION...AIDING IN MORE WIDESPREAD SHOWERS. PWAT VALUES ARE AROUND 1.8 INCHES ON AVERAGE WITH AMPLE MOISTURE IN PLACE. GIVEN THE QUALITY MOISTURE AND SUFFICIENT FORCING FOR ASCENT COMING TOGETHER...HAVE RAISED POPS TO CATEGORICAL FOR THE BULK OF THE AREA THIS MORNING WITH THE EXCEPTION OF A FEW COUNTIES ALONG THE CANADIAN BORDER WHERE SHOWERS SHOULD BE A LITTLE LESS FREQUENT. IN GENERAL THE MOST PERSISTENT RAIN AND HIGHEST AMOUNTS SHOULD FOCUS FROM THE WESTERN SOUTHERN TIER TO THE FINGER LAKES AND SOUTHERN TUG HILL REGION WITH LESSER AMOUNTS NEAR THE INTERNATIONAL BORDER. ENOUGH INSTABILITY WILL REMAIN TO KEEP A FEW EMBEDDED THUNDERSTORMS AS WELL...ALTHOUGH COVERAGE WILL REMAIN WIDELY SCATTERED. A FEW STORMS MAY PRODUCE LOCALLY HEAVY RAINFALL...BUT THIS RISK SHOULD REMAIN VERY ISOLATED AT BEST. THIS AFTERNOON THE AFOREMENTIONED DYNAMICS AND BAROCLINIC LEAF WILL SHIFT SLOWLY SOUTH AND EAST AND TAKE THE STEADIER SHOWERS WITH IT. EXPECT A DRYING TREND FOR THE AFTERNOON FROM NORTHWEST TO SOUTHEAST WITH AREAS ALONG AND NORTH OF THE NYS THRUWAY EVENTUALLY BECOMING MAINLY DRY WITH A FEW BREAKS OF SUNSHINE POSSIBLE LATE. SHOWERS WILL BE SLOWER TO END ACROSS THE SOUTHERN TIER AND ACROSS THE HIGHER TERRAIN EAST OF LAKE ONTARIO. THE EXTENSIVE CLOUD COVER WILL KEEP TEMPERATURES LOWER TODAY ALTHOUGH IT WILL STILL BE VERY MUGGY. EXPECT HIGHS IN THE UPPER 70S ON THE LAKE PLAINS AND LOWER TO MID 70S ACROSS THE HIGHER TERRAIN. THE WARM SPOT SHOULD BE THE SAINT LAWRENCE VALLEY WHERE SHOWERS AND THICKER CLOUD COVER WILL EXIT THE EARLIEST. TONIGHT SHOWERS ACROSS THE SOUTHERN TIER AND CENTRAL NY WILL CONTINUE TO SLOWLY DIMINISH. ENOUGH INSTABILITY MAY DEVELOP IN THE WAKE OF THIS MAIN RAIN AREA TO ALLOW SCATTERED THUNDERSTORMS TO FORM DURING THE LATE AFTERNOON AND EARLY EVENING ACROSS THE NIAGARA PENINSULA. IF THEY MATERIALIZE...A FEW MAY MAKE IT INTO AREAS JUST NORTH OF BUFFALO THIS EVENING. SCATTERED STORMS MAY ALSO FORM OVER SOUTHEAST ONTARIO AND CROSS THE SAINT LAWRENCE INTO THE NORTH COUNTRY THIS EVENING. OTHERWISE EXPECT SOME PARTIAL CLEARING OVERNIGHT ON THE LAKE PLAINS. ACROSS THE HIGHER TERRAIN LOW LEVEL MOISTURE AND WEAK UPSLOPE FLOW AND CONVERGENCE WILL LIKELY SUPPORT EXPANDING LOW CLOUD COVER. EXPECT LOWS IN THE MID TO UPPER 60S ON THE LAKE PLAINS AND LOWER TO MID 60S IN THE SOUTHERN TIER AND NORTH COUNTRY. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... A WARM AND STICKY AIRMASS WILL REMAIN ACROSS THE REGION ON MONDAY...WITH MOST OF THE FORECAST AREA EXPERIENCING MAINLY DRY CONDITIONS. HOWEVER THERE WILL BE THE CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON AND EVENING...MAINLY ACROSS THE INTERIOR SOUTHERN TIER WHERE THE BEST INSTABILITY WILL RESIDE. CAPE VALUES BY LATER IN THE AFTERNOON ACROSS THIS REGION WILL RUN IN THE 1000-1500 J/KG RANGE WITH LI`S POSSIBLY AS LOW AS -4. HOWEVER WITH WEAK 0-6KM BULK SHEAR (~20KTS) AND LACK OF A GOOD SURFACE TRIGGER (ASIDE FROM A POSSIBLE LAKE BREEZE)...NOT EXPECTING ANY THUNDERSTORMS TO REACH SEVERE LIMITS. INSTABILITY LOOKS LOWER ACROSS THE REMAINDER OF THE AREA...AND THUS CONVECTIVE CHANCES LOOK MUCH LOWER AS WELL. TEMPERATURES WILL AGAIN BE ON THE WARM SIDE WITH HIGHS IN THE UPPER 70S TO LOWER 80S. WITH THE LOSS OF DAYTIME HEATING MONDAY NIGHT MOST OF THE DIURNALLY DRIVEN CONVECTION WILL DIMINISH IN COVERAGE...ALTHOUGH A FEW STORMS MAY CONTINUE LATE INTO THE EVENING...ESPECIALLY ACROSS PORTIONS OF THE SOUTHERN TIER. AT THE SAME TIME A COLD FRONT OVER THE UPPER GREAT LAKES WILL BE ADVANCING TOWARD THE REGION AND BE LOCATED WEST OF NEW YORK STATE BY TUESDAY MORNING. THAT SAID...MOST OF THE NIGHT LOOKS TO REMAIN DRY...WITH PRECIP CHANCES STARTING TO INCREASE A BIT ACROSS WESTERN NEW YORK TOWARD TUESDAY MORNING. ANOTHER MILD NIGHT CAN BE EXPECTED WITH LOWS IN THE MID TO UPPER 60S FOR MOST LOCATIONS THANKS TO DEEP SOUTHERLY FLOW OUT AHEAD OF THE APPROACHING COLD FRONT. LATEST GUIDANCE PACKAGE HAS THE COLD FRONT NOW MOVING A BIT SLOWER THAN IN PREVIOUS RUNS. THIS IS MOST LIKELY DUE TO MOST OF THE MODELS NOW COMING INTO AGREEMENT ON THE DEVELOPMENT OF LOW PRESSURE SOMEWHERE IN THE OHIO VALLEY ALONG THE FRONT AND THEN TRACKING IT NORTHEAST ALONG THE BOUNDARY WHICH WOULD SLOW IT DOWN A LITTLE. THAT SAID...IT NOW APPEARS IT WILL TAKE THE BULK OF THE DAY TUESDAY FOR THE COLD FRONT TO SWEEP ACROSS THE REGION WITH SHOWERS AN THUNDERSTORMS LIKELY...WITH LOWER CHANCE POPS BY LATER IN THE DAY ACROSS WESTERN NEW YORK. HIGH PRECIPITABLE WATER VALUES OF 1.7"-1.9" TUESDAY AFTERNOON OFFER THE RISK OF HEAVY DOWNPOURS WITH ANY THUNDERSTORM. SBCAPES OVER 1000 J/KG COMBINED WITH LIFTED INDEX VALUES AT -4C TO -5C ALSO POINT TO THE POSSIBILITY OF STORMS. THE MAIN DIFFERENCES FROM MONDAY ARE THAT 0-6KM BULK SHEAR VALUES LOOK TO BE IN THE 40-45KT RANGE...AND ALSO HAVE THE SURFACE COLD FRONT CROSSING THE FORECAST AREA WHICH WILL SERVE AS THE FOCAL POINT FOR STORMS TO FIRE ALONG. ALL THIS SAID...LOOKS AS THOUGH THERE COULD BE SOME STRONG STORMS...WITH A FEW STORMS POSSIBLY REACHING SEVERE LIMITS. MAIN THREATS APPEAR TO BE GUSTY WINDS ASSOCIATED WITH BOWING LINE SEGMENTS AND MARGINALLY SEVERE HAIL. ANOTHER WARM DAY ON TAP WITH HIGHS IN THE UPPER 70S TO LOWER 80S. THE COLD FRONT WILL SLIDE SOUTH AND EAST OF THE FORECAST AREA TUESDAY EVENING...TAKING THE SHOWERS AND STORMS WITH IT. ALTHOUGH A FEW SHOWERS WILL STILL BE POSSIBLE DURING THE EVENING ACROSS EASTERN AREAS...BUT EVEN HERE THINGS WILL DRY OUT LATER TUESDAY NIGHT AS SURFACE HIGH PRESSURE STARTS TO BUILD EAST ACROSS NEW YORK STATE. LOWS WILL BE GENERALLY IN THE UPPER 50S TO LOWER 60S. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BUILD ACROSS THE REGION WEDNESDAY AND THURSDAY BRINGING IN DRIER AIR AND TEMPERATURES THAT WILL STILL AVERAGE AT OR JUST A BIT ABOVE NORMAL FOR EARLY SEPTEMBER. HIGH PRESSURE WILL THEN SLIDE OFF THE NEW ENGLAND COAST BY FRIDAY. THIS WILL PROVIDE MAINLY DRY CONDITIONS THROUGH MIDWEEK...BEFORE THE NEXT FRONTAL SYSTEM APPROACHES FOR LATE IN THE WEEK AND EARLY WEEKEND. TEMPERATURES WILL BE A BIT ABOVE SEASONAL NORMALS WITH HIGHS IN THE UPPER 70S TO LOW 80S AND LOWS IN THE LOWER 60S. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... A STEADY AREA OF LIGHT RAIN WILL CONTINUE TO MOVE SLOWLY EAST ACROSS THE SOUTHERN TIER...FINGER LAKES...AND CENTRAL NY THROUGH MIDDAY. CIGS/VSBY WILL REMAIN VFR IN MANY AREAS...ALTHOUGH A FEW POCKETS OF MODERATE RAIN WILL PRODUCE MVFR VSBY AT TIMES. EXPECT POCKETS OF MVFR/IFR CIGS TO ALSO BECOME A LITTLE MORE COMMON BY MID MORNING ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER AND FINGER LAKES. THE LOWER ELEVATIONS ON THE LAKE PLAINS SHOULD STAY MAINLY VFR DUE IN PART TO SSW DOWNSLOPE FLOW. THE STEADIER SHOWERS WILL DIMINISH FROM NORTHWEST TO SOUTHEAST DURING THE LATE MORNING TO EARLY AFTERNOON. EXPECT CIGS/VSBY TO IMPROVE TO MAINLY VFR EXCEPT IN ANY HEAVIER SHOWERS AND WIDELY SCATTERED THUNDERSTORMS THAT DEVELOP WITH DAYTIME HEATING THIS AFTERNOON. BY MID AFTERNOON THESE SHOULD BE CONFINED TO THE SOUTHERN TIER AND CENTRAL NY WITH THE REMAINDER OF THE AREA DRY. TONIGHT ANY SHOWERS AND SCATTERED THUNDER ACROSS THE SOUTHERN TIER WILL DIMINISH DURING THE EVENING. MAINLY VFR DURING THE EVENING WILL GIVE WAY TO INCREASING AMOUNTS OF IFR IN LOW STRATUS OVERNIGHT WITH EXTENSIVE LOW LEVEL MOISTURE FIELDS. EXPECT STRATUS TO FORM FIRST ACROSS HIGHER TERRAIN...BUT MAY SPREAD TO THE LOWER ELEVATIONS OF WESTERN NY AS WELL AFTER ABOUT 09Z. AREAS OF FOG AND IFR VSBY ARE LIKELY ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER AND FINGER LAKES AS WELL WHERE THE LOW STRATUS INTERSECTS THE HILLS. OUTLOOK... MONDAY...VFR/MVFR IN SCATTERED SHOWERS AND THUNDERSTORMS. TUESDAY...SHOWERS AND THUNDERSTORMS LIKELY WITH ASSOCIATED BRIEF MVFR/IFR. SOME STORMS MAY BE STRONG. WEDNESDAY AND THURSDAY...VFR. && .MARINE... MODERATE SOUTHERLIES WILL CONTINUE TO PRODUCE MARGINAL SMALL CRAFT ADVISORY CONDITIONS AT THE NORTHEAST END OF LAKE ONTARIO FROM GALLOO ISLAND TO CAPE VINCENT THROUGH EARLY TO MID MORNING BEFORE DIMINISHING. LOW PRESSURE WILL MOVE ACROSS SOUTHERN QUEBEC TODAY WITH WINDS BECOMING MORE SOUTHWEST ON THE LOWER LAKES. THIS WILL ALLOW WINDS TO INCREASE SOMEWHAT ON LAKE ERIE...WITH MARGINAL SMALL CRAFT ADVISORY CONDITIONS FROM MID TO LATE MORNING THROUGH MID TO LATE AFTERNOON. THE PRESSURE GRADIENT RELAXES ACROSS THE LOWER LAKES TONIGHT AS LOW PRESSURE DISSIPATES OVER SOUTHEAST QUEBEC. THIS WILL ALLOW WINDS AND WAVES TO SUBSIDE. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LEZ040- 041. SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR LOZ045. && $$ SYNOPSIS...HITCHCOCK NEAR TERM...HITCHCOCK SHORT TERM...JM LONG TERM...JM/WCH AVIATION...HITCHCOCK MARINE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS RALEIGH NC
813 PM EDT MON SEP 1 2014 .SYNOPSIS...AN AREA OF HIGH PRESSURE WILL EXTEND OVER THE REGION THROUGH TUESDAY. A WEAK SURFACE FRONT WILL SETTLE SOUTHWARD ACROSS CENTRAL NC ON WEDNESDAY. HIGH PRESSURE WILL BUILD BACK OVER THE AREA FOR THE REMAINDER OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 305 PM MONDAY... LATE THIS AFTERNOON THROUGH TONIGHT... SLIGHT TO MODERATELY UNSTABLE COVERS CENTRAL NC AT MID AFTERNOON WITH A WEAK SHEAR AXIS SLOWLY EDGING EASTWARD ACROSS THE REGION. BEST DYNAMICS/LIFT ASSOCIATED WITH THIS FEATURE WELL NORTH OF OUR REGION AS SHEAR AXIS IS IMPEDING UPON A MID-UPPER LEVEL RIDGE POSITIONED OVER EASTERN NC. THE RIDGE WILL CONTINUE TO INHIBIT MOST CONVECTIVE DEVELOPMENT BUT COULD STILL SEE AN ISOLATED STORM OR TWO DEVELOP ACROSS THE REGION. BASED ON 18Z MESO-ANALYSIS...ISOLATED CONVECTIVE DEVELOPMENT APPEARS TO BE FAVORED OVER THE WESTERN PIEDMONT...AND NEAR THE VIRGINIA BORDER COUNTIES. THIS SCENARIO HAS THE SUPPORT OF THE LATEST HRRR (WHICH HAS BEEN TRENDING WETTER). THE CONVECTIVE ALLOWING MODELS...THOUGH...HAVE BEEN TRENDING DRIER AND NOW SUGGEST THAT ISOLATED CONVECTION WILL OCCUR OUTSIDE OF OUR FORECAST AREA. WILL LIKELY SEE PATCHES OF FOG DEVELOP AFTER MIDNIGHT...MAINLY OVER THE COASTAL PLAIN..SANDHILLS AND EASTERN PIEDMONT. HOWEVER DENSE FOG WILL BE RARE WITH BULK OF THE VISIBILITIES AT OR ABOVE 1-2 MILES. MIN TEMPS OVERNIGHT NEAR 70-LOWER 70S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 305 PM MONDAY... TUESDAY AND TUESDAY NIGHT... MID-UPPER LEVEL RIDGE PROJECTED TO SLOWLY WEAKEN THIS PERIOD. THIS MAY ALLOW A FEW MORE T-STORMS TO DEVELOP IN THE SLIGHT-MODERATELY UNSTABLE AIR MASS TUESDAY AFTERNOON- EVENING. IN ADDITION...A S/W RESPONSIBLE FOR TRIGGERING THE CONVECTION ACROSS PARTS OF THE MISSOURI VALLEY/OZARKS THIS AFTERNOON- EVENING WILL APPROACH CENTRAL NC FROM THE NW LATE IN THE DAY. THIS FEATURE MAY TRIGGER ADDITIONAL ISOLATED-SCATTERED CONVECTION TUESDAY EVENING ACROSS THE NW PIEDMONT...AND OVERNIGHT TUESDAY INTO EARLY WEDNESDAY OVER THE REMAINDER OF CENTRAL NC. WHILE FORCING IS BETTER COMPARED TO THE PAST FEW DAYS...LIFT IS STILL CONSIDERED WEAK- MARGINAL AT BEST. THUS WILL LIMIT POPS TO NO HIGHER THAN LOW CHANCE. ANOTHER HOT DAY IN STORE FOR THE REGION. AFTERNOON THICKNESSES WILL REMAIN 20-25M ABOVE NORMAL...SUPPORTIVE OF HIGH TEMPS IN THE LOW-MID 90S UNDER FULL SUN CONDITIONS. WHEN THE HUMIDITY IS FACTORED IN...HEAT INDEX VALUES NEAR 100-104 WILL BE COMMON WITH THE HIGHEST H.I.VALUES IN THE SOUTHERN COASTAL PLAIN AND SANDHILLS. MIN TEMPS TUESDAY NIGHT GENERALLY IN THE LOWER 70S. -WSS FOR WED/WED NIGHT: THE WEAK SURFACE REFLECTION THAT REMAINS FROM THE COLD FRONT APPROACHING CENTRAL NC WILL BECOME EVEN MORE WASHED OUT AS IT SHIFTS INTO THE LEE TROUGH OVER CENTRAL NC. MODELS SHOW A VERY WEAK VORTICITY LOBE ASSOCIATED WITH THIS FRONT PUSHING ESE THROUGH NC EARLY WED... AND ITS APPROACH ALONG WITH LINGERING STRONG LOW LEVEL MOISTURE TRANSPORT OVER ERN NC SHOULD SUPPORT AN AREA OF ATYPICAL MORNING SHOWERS/STORMS OVER THE ERN AND ESPECIALLY SE CWA WED MORNING. THE DEPARTURE AND DAMPENING OF THE MEAN MID LEVEL TROUGH WELL TO OUR NE WILL RESULT IN MODEST RISING HEIGHTS (15-25 M) WITHIN THE FLAT (W-E ORIENTED) MID LEVEL RIDGE ACROSS NC THROUGH WED NIGHT. THE LATEST NAM RUN IS CONSISTENT WITH PREVIOUS RUNS IN BRINGING LOWER PW (UNDER 1.5") INTO MUCH OF THE CWA FROM THE NW WITH A BIT STRONGER 850-700 MB NW WIND AS COMPARED TO THE GFS... WHICH KEEPS PW VALUES UP TO 1.7-1.9". GIVEN THE FACT THAT THE MID LEVEL TROUGH WILL BE DAMPENING WITH LITTLE REASON TO SUPPORT A STRONG PUSH OF DRY AIR PAST THE MOUNTAINS... THE GFS`S MORE SUBDUED TROUGH INFLUENCE APPEARS MORE LIKELY... BASED ON THE PERSISTENCE OF THE STRONG RIDGE. MODERATE INSTABILITY IS EXPECTED OVER ALL BUT PERHAPS THE FAR NW... WITH THE GFS SHOWING MUCAPE PEAKING AT 1000-2500 J/KG. WILL STAY CLOSE TO THE GFS/ECMWF SOLUTION WITH SCATTERED AFTERNOON THROUGH EVENING STORMS... WITH BEST COVERAGE ACROSS THE SOUTHERN CWA AND ALONG/EAST OF THE PERSISTENT LEE TROUGH... AS WELL AS ALONG THE INLAND-TRACKING SEA BREEZE. WITH ABOVE-NORMAL PW AND WEAK MID LEVEL FLOW... SLOW-MOVERS AND HEAVY-RAINERS ARE POSSIBLE. WITH THICKNESSES A TAD LOWER THAN TUE BUT REMAINING 12-20 M ABOVE NORMAL... EXPECT WARM AND STICKY HIGHS OF 91-95... DESPITE A GOOD CHANCE OF DEBRIS CLOUD COVER THROUGH THE DAY. CONVECTION CHANCES SHOULD RECEDE WED NIGHT BUT THE GFS INDICATES PLENTY OF ELEVATED BUOYANCY POTENTIAL OVERNIGHT... INCLUDING MLCAPE OF 500-1000 J/KG RESULTING FROM VERY WARM 960-920 MB TEMPS. WILL HOLD ONTO CHANCE POPS MAINLY SOUTH HALF OVERNIGHT. MUGGY LOWS IN THE LOW-MID 70S. -GIH && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 230 PM MONDAY... FOR THU/FRI: CONTINUED ABOVE-NORMAL WARMTH WITH ONLY MINOR CHANGES IN AIR MASS. AT THE SURFACE... THE WEAK LEE TROUGH HOLDS THROUGH CENTRAL NC... ALONG WITH A HUMID AND SOMEWHAT STAGNANT AIR MASS. A POSITIVELY TILTED TROUGH SHIFTS THROUGH THE PACIFIC NORTHWEST AND SW CANADA INTO THE DAKOTAS THU... RESULTING IN BUILDING HEIGHTS AND GRADUAL MID LEVEL WARMING OVER THE SOUTHEAST STATES. THIS POLAR STREAM TROUGH THEN SHIFTS INTO ERN CANADA... WHILE THE FLAT RIDGE HOLDS ACROSS NC. WITH PLENTY OF LOW LEVEL MOISTURE POOLING... ISOLATED TO SCATTERED STORMS FOCUSED ALONG A SEA BREEZE OR SOME OTHER SUBTLE BOUNDARY REMAIN A GOOD BET... DESPITE THE WARMING TEMPS ALOFT. WILL RETAIN AFTERNOON AND EVENING STORM CHANCES BOTH DAYS... WITH TEMPS HOLDING ABOUT A CATEGORY ABOVE NORMAL AS THICKNESSES STAY 10-15 M ABOVE NORMAL. FOR SAT THROUGH MON: A PATTERN TRANSITION IS LIKELY NEXT WEEKEND. THE INITIAL MID LEVEL TROUGH CONTINUES HEADING EASTWARD OVER ERN CANADA EARLY SAT... HOWEVER A SLUG OF STRONG VORTICITY EMANATING FROM A STRONG COLD VORTEX OVER THE BEAUFORT SEA WILL PUSH EASTWARD CLOSE ON ITS HEELS... TAKING A COLD FRONT TO NEW ENGLAND AND THE OH VALLEY BY EARLY SAT. THE RESULTING TROUGH OVER ERN NOAM SUNDAY SHOULD HELP PUSH THE FRONT SOUTHWARD INTO NC... AFTER WHICH TIME IT IS APT TO LAY WEST/EAST AND STALL OVER THE CAROLINAS FOR LATE SUN THROUGH MON. THE GFS HAS A STRONGER/FASTER TIME FRAME THAN THE ECMWF... WITH THE FORMER MODEL SOLUTION TAKING THICKNESSES MUCH COLDER... UP TO 25 M BELOW NORMAL AS OPPOSED TO THE ECMWF WHICH IS BARELY 5 M BELOW NORMAL. TOUGH TO RESOLVE SUCH DIFFERENCES BUT GIVEN THE STRENGTH OF THE SRN CONUS RIDGE... AND THE FAR-NORTH TRACK OF THE POLAR LOW... I REMAIN SKEPTICAL ABOUT A STRONG COLD FRONTAL PASSAGE THROUGH NC. WILL STAY ON THE CONSERVATIVE SIDE OF THE TEMP TREND... WITH HIGHS/LOWS INITIALLY AROUND 90/AROUND 70 SAT... SLIPPING TO LOW-MID 80S/UPPER 60S BY MON. PRECIP CHANCES AND PATTERNS ARE LIKELY TO CHANGE LITTLE THROUGH SUN... PERHAPS INCREASING IN COVERAGE AS THE FRONT APPROACHES WITH FALLING HEIGHTS ALOFT... STRENGTHENING (YET STILL SOMEWHAT WEAK) MID LEVEL FLOW... AND A PERSISTENT CONFLUENT INFLUX OF GULF AND ATLANTIC MOISTURE IN THE LOW LEVELS. WILL MAINTAIN SCATTERED SHOWERS AND STORMS FOCUSED ON -- BUT NOT RESTRICTED TO -- AFTERNOON AND EVENING HOURS. WILL KEEP A CLIMO CHANCE POP ON MON... WITH LOWER THAN USUAL CONFIDENCE AS CONVECTION WILL GREATLY DEPEND ON WHETHER THE FRONT HOLDS UP ACROSS NC OR SHIFTS TO OUR SOUTH. -GIH && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... AS OF 800 PM MONDAY... MOSTLY VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGHOUT THE CURRENT TAF PERIOD. THE EXCEPTION WILL A BRIEF PERIOD OF LOW STRATUS/FOG TOWARDS DAYBREAK ON TUESDAY...MOST LIKELY ACROSS THE EASTERN HALF OF THE FORECAST AREA AND WITH KRWI HAVING THE HIGHEST PROBABILITY (GIVEN THE PERSISTENT AIR MASS IN PLACE). AFTER ALMOST CALM WINDS OVERNIGHT...MOSTLY LIGHT (UNDER 10 KNOTS) SOUTHWESTERLY WINDS WILL PREVAIL. ISOLATED STORMS ARE EXPECTED TUESDAY AFTERNOON/EVENING. OUTLOOK...TYPICAL SUMMERTIME CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE PERIOD...FEATURING DIURNAL CONVECTION EACH AFTERNOON/EVENING AND PATCHY FOG/LOW CLOUDS DURING THE PRE-DAWN MORNING HOURS. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...WSS SHORT TERM...WSS/HARTFIELD LONG TERM...HARTFIELD AVIATION...KRD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
729 AM EDT SUN AUG 31 2014 .SYNOPSIS... STRENGTHENING BERMUDA HIGH PRESSURE OFFSHORE WILL BRING SUMMERTIME HEAT AND HUMIDITY THROUGH THE LABOR DAY WEEKEND WITH A FEW SHOWERS AND THUNDERSTORMS POSSIBLE. A WEAK COLD FRONT WILL APPROACH FROM THE NORTH LATE NEXT WEEK...BUT WILL LIKELY STALL BEFORE REACHING THE AREA. BERMUDA HIGH PRESSURE AND A PIEDMONT TROUGH WILL REMAIN THE DOMINANT FEATURES INTO NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM SUNDAY...SURFACE HIGH PRESSURE COVERS MUCH OF THE WESTERN AND CENTRAL ATLANTIC OCEAN. THE UPPER LEVEL RIDGE IS CENTERED JUST OFF THE CAROLINA COAST AND SHOULD KEEP ANY SYNOPTIC IMPULSES DEFLECTED AWAY TO OUR NORTH AND WEST. 850 MB TEMPERATURES AROUND +18C THIS AFTERNOON SHOULD RESULT IN HIGH TEMPERATURES IN THE MID 90S FROM MARION AND FLORENCE WESTWARD INTO DARLINGTON COUNTY. ONSHORE WINDS CLOSER TO THE COAST SHOULD KEEP TEMPERATURES A LITTLE COOLER...GENERALLY IN THE UPPER 80S TO LOWER 90S. ALTHOUGH THERE IS CONSIDERABLE DRY AIR ALOFT DUE TO THE UPPER RIDGE (COLUMN PRECIP WATER VALUES ARE ONLY 1.5 INCHES) VERY RICH MOISTURE EXISTS IN THE LOWEST LEVELS OF THE ATMOSPHERE. DEWPOINTS IN THE MID 70S THIS MORNING WILL FORTUNATELY MIX DOWN TO NEAR 70 THIS AFTERNOON INLAND...BUT THAT WILL STILL BE ENOUGH TO PUSH HEAT INDICES TO 100-103 DEGREES ACROSS MOST OF OUR FORECAST AREA. THIS MOISTURE MAY ALSO FUEL WIDELY SCATTERED SHOWERS NEAR THIS COAST LATER THIS MORNING...PROBABLY BECOMING LESSER IN COVERAGE THIS AFTERNOON AS DRIER AIR MIXES DOWNWARD. FORECAST POPS RANGE FROM 20-30 PERCENT... VIRTUALLY ALL EAST OF I-95 AND HIGHEST IN A STRIPE ACROSS LELAND TO BURGAW AS CONSISTENTLY INDICATED BY HOURLY HRRR MODEL RUNS THROUGH THE NIGHT. ANY LINGERING DAYTIME CUMULUS SHOULD QUICKLY DIE AWAY THIS EVENING... WITH ONLY A LITTLE PATCHY FOG OR LOW STRATUS EXPECTED TO DEVELOP OVERNIGHT. LOWS SHOULD FALL INTO THE LOWER 70S FOR MOST LOCALES...A FEW DEGREES WARMER NEAR THE BEACHES. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 AM SUNDAY...BERMUDA HIGH AND STRENGTHENING PIEDMONT TROUGH WILL BE THE MAIN SURFACE FEATURES THROUGH THE PERIOD. ALOFT A FLAT MID LEVEL RIDGE WILL EXTEND ACROSS MUCH OF THE SOUTHERN CONUS. DEEP WESTERLY FLOW IN THE MID LEVELS WILL PUSH TROPICAL MOISTURE EXPANDING NORTH FROM THE WESTERN GULF OF MEXICO OVER THE REGION MON AND TUE. INCREASING MOISTURE ALOFT ALONG WITH LOW LEVEL MOISTURE ADVECTION AROUND WEST SIDE OF BERMUDA HIGH WILL PUSH PRECIPITABLE WATER VALUES OVER 2 INCHES FOR MUCH OF THE PERIOD. FLAT MID LEVEL PATTERN MEANS LITTLE TO NO FORCING ALOFT WILL BE PRESENT. HOWEVER THE COMBINATION OF LOW LEVEL MOISTURE AND SURFACE HEATING WILL PUSH ML CAPE VALUES TO 1K-2K J/KG FOR MON AND OVER 2K J/KG ON TUE. CONVECTION WILL INITIALLY BE SLOW TO DEVELOP BUT ONCE SEA BREEZE AND PIEDMONT TROUGH TAKE SHAPE SHOWERS AND THUNDERSTORMS SHOULD START POPPING UP. WILL MAINTAIN CHC POP FOR EACH AFTERNOON BUT WITH SLIGHTLY HIGHER VALUES ON TUE GIVEN SLIGHTLY HIGHER CAPE VALUES. TEMPERATURES WILL RUN ABOVE CLIMO THROUGH THE PERIOD. HIGHS WILL RANGE FROM UPPER 80S ALONG THE IMMEDIATE COAST TO MID 90S INLAND. LOWS WILL BE IN THE LOW TO MID 70S. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 3 AM SUNDAY...BERMUDA HIGH AND PIEDMONT TROUGH ALONG WITH ELONGATED MID LEVEL RIDGE WILL REMAIN THE SIGNIFICANT FEATURES THROUGH THE PERIOD. A COUPLE COLD FRONTS WILL TRY AND MAKE A RUN TO THE AREA DURING THE NEXT WEEK BUT THEY ARE LIKELY TO STALL AND WASH OUT JUST NORTH OF THE FORECAST AREA. THE SURFACE AND MID LEVEL PATTERNS ARE NOT ONES THAT GENERALLY SUPPORT FRONTS MOVING INTO AND SOUTH OF THE CAPE FEAR REGION. PRECIPITABLE WATER VALUES WILL REMAIN AROUND 2 INCHES THROUGH THE END OF THE WEEK. DIURNAL HEATING AND SOUTHWEST FLOW WILL RESULT IN ML CAPE VALUES ABOVE 2K J/KG FOR MUCH OF THE PERIOD. WEAK GRADIENT WILL ALLOW SEA BREEZE DEVELOPMENT AND PIEDMONT TROUGH SHOULD BE WELL DEFINED. TYPICAL SUMMER PATTERN WITH NEAR CLIMO PWATS AND TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO SUGGEST POP WILL BE NEAR CLIMO FOR MUCH OF THE PERIOD...30 PERCENT. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... AS OF 12Z...IFR TEMPO LIFR IN BR/FG OCCURRING AT KFLO THIS MORNING. KLBT IS VFR. TEMPO MVFR CIGS ARE OCCURRING AT KCRE/KMYR. ISOLATED LIGHT SHOWERS ARE MOVING N ACROSS THE NEAR SHORE WATERS. BR/FG SHOULD BURN OFF AROUND 14Z AT KFLO. VFR IS THEN EXPECTED AT BOTH KFLO/KLBT INTO THIS EVENING. TEMPO MVFR CIGS/SHOWERS WILL REMAIN POSSIBLE AT THE COASTAL TERMINALS UNTIL THE SEA SHIFTS FURTHER INLAND MID-LATE MORNING. BEST CONFIDENCE OF A TEMPO SHOWER IS AT KILM. VFR IS THEN EXPECTED AFTERWARDS AT THE COASTAL TERMINALS INTO THIS EVENING. THIS AFTERNOON THE BEST SHOWER POTENTIAL WILL BE BETWEEN THE INLAND AND COASTAL TERMINALS. SE-S WINDS WILL INCREASE TO 10-20 KT AT THE COASTAL TERMINALS AND 5 TO 10 KT AT KFLO/KLBT LATER THIS MORNING. WINDS SLOWLY DECREASE THIS EVENING...BECOMING LGT S-SW THIS EVENING AND OVERNIGHT. BEST BR/FG POTENTIAL WILL BE THE INLAND TERMINALS OVERNIGHT...WITH IFR VSBYS/LIFR CIGS LIKELY KFLO/KLBT BY 08Z. EXTENDED OUTLOOK...INCREASING CHANCES FOR AFTN SHOWERS/TSTMS MONDAY THROUGH THURSDAY WITH BRIEF AND LOCALIZED PERIODS OF MVFR POSSIBLE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM SUNDAY...SURFACE HIGH PRESSURE COVERS MOST OF THE WESTERN AND CENTRAL ATLANTIC OCEAN. THIS SHOULD PRODUCE A SOUTH-SOUTHEAST WIND TODAY...VEERING MORE SOUTHWESTERLY TONIGHT. SEAS CURRENTLY AROUND 2 FEET MAY OCCASIONALLY REACH 3 FEET IN A COMBINATION OF SOUTHEASTERLY SWELL AND LOCAL WIND WAVES...WITH ANY SCATTERED MORNING SHOWERS EXPECTED TO DISSIPATE BY EARLY AFTERNOON. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 AM SUNDAY...BERMUDA HIGH AND PIEDMONT TROUGH WILL MAINTAIN SOUTHWEST FLOW OVER THE WATERS THROUGH THE PERIOD. SPEEDS 10 KT OR LESS WILL INCREASE TO A SOLID 15 KT EACH AFTERNOON AND EVENING AS THE PIEDMONT TROUGH STRENGTHENS. SEAS IN THE 2 TO 3 FT RANGE. LONG TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 3 AM SUNDAY...MINIMAL CHANGE FOR THE LONG TERM PERIOD. BERMUDA HIGH REMAINS IN PLACE AS DOES THE PIEDMONT TROUGH. LATE IN THE PERIOD A WEAKENING COLD FRONT WILL APPROACH FROM THE NORTH BUT IS EXPECTED TO STALL BEFORE REACHING THE AREA. SOUTHWEST FLOW AROUND 10 KT WILL INCREASE TO A SOLID 15 KT EACH AFTERNOON AND EVENING. SEAS WILL RUN 2 TO 3 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...III LONG TERM...III AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
633 AM EDT SUN AUG 31 2014 .SYNOPSIS... STRENGTHENING BERMUDA HIGH PRESSURE OFFSHORE WILL BRING SUMMERTIME HEAT AND HUMIDITY THROUGH THE LABOR DAY WEEKEND WITH A FEW SHOWERS AND THUNDERSTORMS POSSIBLE. A WEAK COLD FRONT WILL APPROACH FROM THE NORTH LATE NEXT WEEK...BUT WILL LIKELY STALL BEFORE REACHING THE AREA. BERMUDA HIGH PRESSURE AND A PIEDMONT TROUGH WILL REMAIN THE DOMINANT FEATURES INTO NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM SUNDAY...SURFACE HIGH PRESSURE COVERS MUCH OF THE WESTERN AND CENTRAL ATLANTIC OCEAN. THE UPPER LEVEL RIDGE IS CENTERED JUST OFF THE CAROLINA COAST AND SHOULD KEEP ANY SYNOPTIC IMPULSES DEFLECTED AWAY TO OUR NORTH AND WEST. 850 MB TEMPERATURES AROUND +18C THIS AFTERNOON SHOULD RESULT IN HIGH TEMPERATURES IN THE MID 90S FROM MARION AND FLORENCE WESTWARD INTO DARLINGTON COUNTY. ONSHORE WINDS CLOSER TO THE COAST SHOULD KEEP TEMPERATURES A LITTLE COOLER...GENERALLY IN THE UPPER 80S TO LOWER 90S. ALTHOUGH THERE IS CONSIDERABLE DRY AIR ALOFT DUE TO THE UPPER RIDGE (COLUMN PRECIP WATER VALUES ARE ONLY 1.5 INCHES) VERY RICH MOISTURE EXISTS IN THE LOWEST LEVELS OF THE ATMOSPHERE. DEWPOINTS IN THE MID 70S THIS MORNING WILL FORTUNATELY MIX DOWN TO NEAR 70 THIS AFTERNOON INLAND...BUT THAT WILL STILL BE ENOUGH TO PUSH HEAT INDICES TO 100-103 DEGREES ACROSS MOST OF OUR FORECAST AREA. THIS MOISTURE MAY ALSO FUEL WIDELY SCATTERED SHOWERS NEAR THIS COAST LATER THIS MORNING...PROBABLY BECOMING LESSER IN COVERAGE THIS AFTERNOON AS DRIER AIR MIXES DOWNWARD. FORECAST POPS RANGE FROM 20-30 PERCENT... VIRTUALLY ALL EAST OF I-95 AND HIGHEST IN A STRIPE ACROSS LELAND TO BURGAW AS CONSISTENTLY INDICATED BY HOURLY HRRR MODEL RUNS THROUGH THE NIGHT. ANY LINGERING DAYTIME CUMULUS SHOULD QUICKLY DIE AWAY THIS EVENING... WITH ONLY A LITTLE PATCHY FOG OR LOW STRATUS EXPECTED TO DEVELOP OVERNIGHT. LOWS SHOULD FALL INTO THE LOWER 70S FOR MOST LOCALES...A FEW DEGREES WARMER NEAR THE BEACHES. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 AM SUNDAY...BERMUDA HIGH AND STRENGTHENING PIEDMONT TROUGH WILL BE THE MAIN SURFACE FEATURES THROUGH THE PERIOD. ALOFT A FLAT MID LEVEL RIDGE WILL EXTEND ACROSS MUCH OF THE SOUTHERN CONUS. DEEP WESTERLY FLOW IN THE MID LEVELS WILL PUSH TROPICAL MOISTURE EXPANDING NORTH FROM THE WESTERN GULF OF MEXICO OVER THE REGION MON AND TUE. INCREASING MOISTURE ALOFT ALONG WITH LOW LEVEL MOISTURE ADVECTION AROUND WEST SIDE OF BERMUDA HIGH WILL PUSH PRECIPITABLE WATER VALUES OVER 2 INCHES FOR MUCH OF THE PERIOD. FLAT MID LEVEL PATTERN MEANS LITTLE TO NO FORCING ALOFT WILL BE PRESENT. HOWEVER THE COMBINATION OF LOW LEVEL MOISTURE AND SURFACE HEATING WILL PUSH ML CAPE VALUES TO 1K-2K J/KG FOR MON AND OVER 2K J/KG ON TUE. CONVECTION WILL INITIALLY BE SLOW TO DEVELOP BUT ONCE SEA BREEZE AND PIEDMONT TROUGH TAKE SHAPE SHOWERS AND THUNDERSTORMS SHOULD START POPPING UP. WILL MAINTAIN CHC POP FOR EACH AFTERNOON BUT WITH SLIGHTLY HIGHER VALUES ON TUE GIVEN SLIGHTLY HIGHER CAPE VALUES. TEMPERATURES WILL RUN ABOVE CLIMO THROUGH THE PERIOD. HIGHS WILL RANGE FROM UPPER 80S ALONG THE IMMEDIATE COAST TO MID 90S INLAND. LOWS WILL BE IN THE LOW TO MID 70S. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 3 AM SUNDAY...BERMUDA HIGH AND PIEDMONT TROUGH ALONG WITH ELONGATED MID LEVEL RIDGE WILL REMAIN THE SIGNIFICANT FEATURES THROUGH THE PERIOD. A COUPLE COLD FRONTS WILL TRY AND MAKE A RUN TO THE AREA DURING THE NEXT WEEK BUT THEY ARE LIKELY TO STALL AND WASH OUT JUST NORTH OF THE FORECAST AREA. THE SURFACE AND MID LEVEL PATTERNS ARE NOT ONES THAT GENERALLY SUPPORT FRONTS MOVING INTO AND SOUTH OF THE CAPE FEAR REGION. PRECIPITABLE WATER VALUES WILL REMAIN AROUND 2 INCHES THROUGH THE END OF THE WEEK. DIURNAL HEATING AND SOUTHWEST FLOW WILL RESULT IN ML CAPE VALUES ABOVE 2K J/KG FOR MUCH OF THE PERIOD. WEAK GRADIENT WILL ALLOW SEA BREEZE DEVELOPMENT AND PIEDMONT TROUGH SHOULD BE WELL DEFINED. TYPICAL SUMMER PATTERN WITH NEAR CLIMO PWATS AND TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO SUGGEST POP WILL BE NEAR CLIMO FOR MUCH OF THE PERIOD...30 PERCENT. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 06Z...STILL EXPECT MVFR/IFR CIGS TO DEVELOP EARLY THIS MORNING WITH THE BEST CHANCES FOR IFR INLAND AT KLBT/KFLO. HAVE BACKED OFF THE FOG A BIT GIVEN THE INCREASING DEBRIS CLOUDS SPREADING INTO OUR AREA. WOULD NOT RULE OUT TEMPO IFR VSBYS INLAND...BUT MVFR SEEMS MORE LIKELY ATTM. EXPECT PERIODS OF MVFR CIGS ALONG THE COAST BEGINNING AROUND DAYBREAK...WITH THE POTENTIAL FOR SOME ISOLATED SHOWERS MOVING ONSHORE AS WELL. THE HRRR MODEL SHOWS A FEW SHOWERS SKIRTING THE COAST THIS MORNING...SO WILL MAINTAIN VCSH FOR KILM/KCRE/KMYR. THE MVFR CIGS MAY LINGER THROUGH MUCH OF THE MORNING...BUT CONDITIONS WILL IMPROVE TO VFR BY MIDDAY AND PERSIST THROUGH THE REST OF THE PERIOD. WINDS WILL BE SOUTH 6-10 KT DURING THE DAY...POSSIBLY A BIT HIGHER ALONG THE COAST. COULD SEE SOME ISOLATED SHOWERS ALONG THE SEABREEZE FONT IN THE AFTN...BUT CONFIDENCE IN TIMING/LOCATION IS TOO LOW TO MENTION IN THE TAFS. EXTENDED OUTLOOK...INCREASING CHANCES FOR AFTN SHOWERS/TSTMS MONDAY THROUGH THURSDAY WITH BRIEF AND LOCALIZED PERIODS OF MVFR POSSIBLE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM SUNDAY...SURFACE HIGH PRESSURE COVERS MOST OF THE WESTERN AND CENTRAL ATLANTIC OCEAN. THIS SHOULD PRODUCE A SOUTH-SOUTHEAST WIND TODAY...VEERING MORE SOUTHWESTERLY TONIGHT. SEAS CURRENTLY AROUND 2 FEET MAY OCCASIONALLY REACH 3 FEET IN A COMBINATION OF SOUTHEASTERLY SWELL AND LOCAL WIND WAVES...WITH ANY SCATTERED MORNING SHOWERS EXPECTED TO DISSIPATE BY EARLY AFTERNOON. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 AM SUNDAY...BERMUDA HIGH AND PIEDMONT TROUGH WILL MAINTAIN SOUTHWEST FLOW OVER THE WATERS THROUGH THE PERIOD. SPEEDS 10 KT OR LESS WILL INCREASE TO A SOLID 15 KT EACH AFTERNOON AND EVENING AS THE PIEDMONT TROUGH STRENGTHENS. SEAS IN THE 2 TO 3 FT RANGE. LONG TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 3 AM SUNDAY...MINIMAL CHANGE FOR THE LONG TERM PERIOD. BERMUDA HIGH REMAINS IN PLACE AS DOES THE PIEDMONT TROUGH. LATE IN THE PERIOD A WEAKENING COLD FRONT WILL APPROACH FROM THE NORTH BUT IS EXPECTED TO STALL BEFORE REACHING THE AREA. SOUTHWEST FLOW AROUND 10 KT WILL INCREASE TO A SOLID 15 KT EACH AFTERNOON AND EVENING. SEAS WILL RUN 2 TO 3 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...III LONG TERM...III AVIATION...BJR/TRA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
311 AM EDT SUN AUG 31 2014 .SYNOPSIS... STRENGTHENING BERMUDA HIGH PRESSURE OFFSHORE WILL BRING SUMMERTIME HEAT AND HUMIDITY THROUGH THE LABOR DAY WEEKEND WITH A FEW SHOWERS AND THUNDERSTORMS POSSIBLE. A WEAK COLD FRONT WILL APPROACH FROM THE NORTH LATE NEXT WEEK...BUT WILL LIKELY STALL BEFORE REACHING THE AREA. BERMUDA HIGH PRESSURE AND A PIEDMONT TROUGH WILL REMAIN THE DOMINANT FEATURES INTO NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 AM SUNDAY...SURFACE HIGH PRESSURE COVERS MUCH OF THE WESTERN AND CENTRAL ATLANTIC OCEAN. THE UPPER LEVEL RIDGE IS CENTERED JUST OFF THE CAROLINA COAST AND SHOULD KEEP ANY SYNOPTIC IMPULSES DEFLECTED AWAY TO OUR NORTH AND WEST. 850 MB TEMPERATURES AROUND +18C THIS AFTERNOON SHOULD RESULT IN HIGH TEMPERATURES IN THE MID 90S FROM MARION AND FLORENCE WESTWARD INTO DARLINGTON COUNTY. ONSHORE WINDS CLOSER TO THE COAST SHOULD KEEP TEMPERATURES A LITTLE COOLER...GENERALLY IN THE UPPER 80S TO LOWER 90S. ALTHOUGH THERE IS CONSIDERABLE DRY AIR ALOFT DUE TO THE UPPER RIDGE (COLUMN PRECIP WATER VALUES ARE ONLY 1.5 INCHES) VERY RICH MOISTURE EXISTS IN THE LOWEST LEVELS OF THE ATMOSPHERE. DEWPOINTS IN THE MID 70S THIS MORNING WILL FORTUNATELY MIX DOWN TO NEAR 70 THIS AFTERNOON INLAND...BUT THAT WILL STILL BE ENOUGH TO PUSH HEAT INDICES TO 100-103 DEGREES ACROSS MOST OF OUR FORECAST AREA. THIS MOISTURE MAY ALSO FUEL WIDELY SCATTERED SHOWERS NEAR THIS COAST LATER THIS MORNING...PROBABLY BECOMING LESSER IN COVERAGE THIS AFTERNOON AS DRIER AIR MIXES DOWNWARD. FORECAST POPS RANGE FROM 20-30 PERCENT... VIRTUALLY ALL EAST OF I-95. ANY LINGERING DAYTIME CUMULUS SHOULD QUICKLY DIE AWAY THIS EVENING... WITH ONLY A LITTLE PATCHY FOG OR LOW STRATUS EXPECTED TO DEVELOP OVERNIGHT. LOWS SHOULD FALL INTO THE LOWER 70S FOR MOST LOCALES...A FEW DEGREES WARMER NEAR THE BEACHES. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 AM SUNDAY...BERMUDA HIGH AND STRENGTHENING PIEDMONT TROUGH WILL BE THE MAIN SURFACE FEATURES THROUGH THE PERIOD. ALOFT A FLAT MID LEVEL RIDGE WILL EXTEND ACROSS MUCH OF THE SOUTHERN CONUS. DEEP WESTERLY FLOW IN THE MID LEVELS WILL PUSH TROPICAL MOISTURE EXPANDING NORTH FROM THE WESTERN GULF OF MEXICO OVER THE REGION MON AND TUE. INCREASING MOISTURE ALOFT ALONG WITH LOW LEVEL MOISTURE ADVECTION AROUND WEST SIDE OF BERMUDA HIGH WILL PUSH PRECIPITABLE WATER VALUES OVER 2 INCHES FOR MUCH OF THE PERIOD. FLAT MID LEVEL PATTERN MEANS LITTLE TO NO FORCING ALOFT WILL BE PRESENT. HOWEVER THE COMBINATION OF LOW LEVEL MOISTURE AND SURFACE HEATING WILL PUSH ML CAPE VALUES TO 1K-2K J/KG FOR MON AND OVER 2K J/KG ON TUE. CONVECTION WILL INITIALLY BE SLOW TO DEVELOP BUT ONCE SEA BREEZE AND PIEDMONT TROUGH TAKE SHAPE SHOWERS AND THUNDERSTORMS SHOULD START POPPING UP. WILL MAINTAIN CHC POP FOR EACH AFTERNOON BUT WITH SLIGHTLY HIGHER VALUES ON TUE GIVEN SLIGHTLY HIGHER CAPE VALUES. TEMPERATURES WILL RUN ABOVE CLIMO THROUGH THE PERIOD. HIGHS WILL RANGE FROM UPPER 80S ALONG THE IMMEDIATE COAST TO MID 90S INLAND. LOWS WILL BE IN THE LOW TO MID 70S. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 3 AM SUNDAY...BERMUDA HIGH AND PIEDMONT TROUGH ALONG WITH ELONGATED MID LEVEL RIDGE WILL REMAIN THE SIGNIFICANT FEATURES THROUGH THE PERIOD. A COUPLE COLD FRONTS WILL TRY AND MAKE A RUN TO THE AREA DURING THE NEXT WEEK BUT THEY ARE LIKELY TO STALL AND WASH OUT JUST NORTH OF THE FORECAST AREA. THE SURFACE AND MID LEVEL PATTERNS ARE NOT ONES THAT GENERALLY SUPPORT FRONTS MOVING INTO AND SOUTH OF THE CAPE FEAR REGION. PRECIPITABLE WATER VALUES WILL REMAIN AROUND 2 INCHES THROUGH THE END OF THE WEEK. DIURNAL HEATING AND SOUTHWEST FLOW WILL RESULT IN ML CAPE VALUES ABOVE 2K J/KG FOR MUCH OF THE PERIOD. WEAK GRADIENT WILL ALLOW SEA BREEZE DEVELOPMENT AND PIEDMONT TROUGH SHOULD BE WELL DEFINED. TYPICAL SUMMER PATTERN WITH NEAR CLIMO PWATS AND TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO SUGGEST POP WILL BE NEAR CLIMO FOR MUCH OF THE PERIOD...30 PERCENT. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... AS OF 06Z...STILL EXPECT MVFR/IFR CIGS TO DEVELOP EARLY THIS MORNING WITH THE BEST CHANCES FOR IFR INLAND AT KLBT/KFLO. HAVE BACKED OFF THE FOG A BIT GIVEN THE INCREASING DEBRIS CLOUDS SPREADING INTO OUR AREA. WOULD NOT RULE OUT TEMPO IFR VSBYS INLAND...BUT MVFR SEEMS MORE LIKELY ATTM. EXPECT PERIODS OF MVFR CIGS ALONG THE COAST BEGINNING AROUND DAYBREAK...WITH THE POTENTIAL FOR SOME ISOLATED SHOWERS MOVING ONSHORE AS WELL. THE HRRR MODEL SHOWS A FEW SHOWERS SKIRTING THE COAST THIS MORNING...SO WILL MAINTAIN VCSH FOR KILM/KCRE/KMYR. THE MVFR CIGS MAY LINGER THROUGH MUCH OF THE MORNING...BUT CONDITIONS WILL IMPROVE TO VFR BY MIDDAY AND PERSIST THROUGH THE REST OF THE PERIOD. WINDS WILL BE SOUTH 6-10 KT DURING THE DAY...POSSIBLY A BIT HIGHER ALONG THE COAST. COULD SEE SOME ISOLATED SHOWERS ALONG THE SEABREEZE FONT IN THE AFTN...BUT CONFIDENCE IN TIMING/LOCATION IS TOO LOW TO MENTION IN THE TAFS. EXTENDED OUTLOOK...INCREASING CHANCES FOR AFTN SHOWERS/TSTMS MONDAY THROUGH THURSDAY WITH BRIEF AND LOCALIZED PERIODS OF MVFR POSSIBLE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 AM SUNDAY...SURFACE HIGH PRESSURE COVERS MOST OF THE WESTERN AND CENTRAL ATLANTIC OCEAN. THIS SHOULD PRODUCE A SOUTH-SOUTHEAST WIND TODAY...VEERING MORE SOUTHWESTERLY TONIGHT. SEAS CURRENTLY AROUND 2 FEET MAY OCCASIONALLY REACH 3 FEET IN A COMBINATION OF SOUTHEASTERLY SWELL AND LOCAL WIND WAVES...WITH ANY SCATTERED MORNING SHOWERS EXPECTED TO DISSIPATE BY EARLY AFTERNOON. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 AM SUNDAY...BERMUDA HIGH AND PIEDMONT TROUGH WILL MAINTAIN SOUTHWEST FLOW OVER THE WATERS THROUGH THE PERIOD. SPEEDS 10 KT OR LESS WILL INCREASE TO A SOLID 15 KT EACH AFTERNOON AND EVENING AS THE PIEDMONT TROUGH STRENGTHENS. SEAS IN THE 2 TO 3 FT RANGE. LONG TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 3 AM SUNDAY...MINIMAL CHANGE FOR THE LONG TERM PERIOD. BERMUDA HIGH REMAINS IN PLACE AS DOES THE PIEDMONT TROUGH. LATE IN THE PERIOD A WEAKENING COLD FRONT WILL APPROACH FROM THE NORTH BUT IS EXPECTED TO STALL BEFORE REACHING THE AREA. SOUTHWEST FLOW AROUND 10 KT WILL INCREASE TO A SOLID 15 KT EACH AFTERNOON AND EVENING. SEAS WILL RUN 2 TO 3 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...III LONG TERM...III AVIATION...BJR/TRA
AREA FORECAST DISCUSSION
NWS RALEIGH NC
220 AM EDT SUN AUG 31 2014 .SYNOPSIS...HIGH PRESSURE WILL EXTEND OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK. A WEAKENING COLD FRONT WILL APPROACH THE REGION FROM THE NORTH ON WEDNESDAY... BEFORE RETREATING THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1045 PM SATURDAY... THE LATEST SURFACE ANALYSIS CONTINUED TO SHOW A SLACK GRADIENT OVER CENTRAL NORTH CAROLINA. RADAR SHOWED EARLIER SHOWERS HAD DIMINISHED...AS THE SEA BREEZE HAD MOVED NORTH AND WEAKENED WHILE VERY DRY MID-LEVEL AIR MOVED EAST ACROSS CENTRAL AND EASTERN NORTH CAROLINA ON WATER VAPOR IMAGERY. K INDICES SHOULD FALL INTO THE TEENS AS BUFR SOUNDINGS FROM THE GFS AND NAM ALONG WITH RAP SOUNDINGS SHOW AN OVERALL STABLE AIR MASS THEN. SOME OF THE TEMPERATURES ACROSS CENTRAL NORTH CAROLINA FELL QUICKLY DURING MID-EVENING...BUT WITH SOME THIN CIRRUS MOVING EAST FROM DEEP CONVECTION WELL UPSTREAM...ALONG WITH SURFACE DEW POINTS AROUND 70 TO THE LOWER 70S IN MOST LOCATIONS...TEMPERATURES ARE NOT EXPECTED TO CONTINUE THAT RAPID FALL. LOWS SHOULD MOSTLY BE WITHIN A DEGREE OR TWO OF 70. SOME LOW CLOUDS REMAIN POSSIBLE LATE TONIGHT PARTICULARLY AS NOTED ON NAM BUFR SOUNDINGS AND THE SREF PROBABILISTIC GUIDANCE...AND ALLUDED TO MORE ON THE GFS 18Z MOS GUIDANCE OUTPUT FROM ITS EARLIER...MORE OPTIMISTIC 12Z GUIDANCE. THE LATEST HRRR WRF WOULD SUGGEST A BETTER POTENTIAL FOR LOW CLOUDS LATE TONIGHT IN A NARROW AXIS ALONG AND WEST OF U.S. 1...WHERE SREF PROBABILITIES ARE A LITTLE HIGHER RELATIVE TO THE REST OF THE AREA AND CLOSER TO THE HIGHER 925MB WINDS. THOSE 925MB WINDS SEEM A LITTLE HIGH FOR FOG IN MOST PLACES...TO 20KT TOWARD THE TRIAD LATE TONIGHT...BUT THE LOWER VALUES OF 10 TO 15KT TOWARD INTERSTATE 95 ALONG WITH EXPECTED DEW POINTS IN THE LOWER 70S COULD ALLOW A LITTLE MORE NOTICEABLE FOG IN PATCHES TOWARD THERE LATE. && .SHORT TERM /SUNDAY AND SUNDAY NIGHT/... AS OF 230 PM SATURDAY... A SHORT WAVE TROUGH OVER THE MS RIVER VALLEY TO START THE DAY WILL LIFT TO THE NORTHEAST INTO THE OH VALLEY THROUGH SUNDAY NIGHT. HOWEVER...ITS ASSOCIATED ENERGY AND DEEP MOISTURE PLUME (EMANATING FROM THE GULF) WILL LARGELY REMAIN WEST AND NORTH OF CENTRAL NC. IN ADDITION...THE SUBTROPICAL RIDGE CENTERED OVER THE SOUTHEAST COAST SHOULD ALSO HELP KEEP THE BETTER RAIN CHANCES WEST OF THE AREA. THEREFORE...WILL CONTINUE THE FORECAST THINKING OF ONLY ISOLATED TO WIDELY SCATTERED SHOWERS/STORMS...WITH THE BEST CHANCES ACROSS THE WEST DUE TO THE PROXIMITY OF THE ABOVE FEATURES. TEMPS WILL CONTINUE TO BE ABOVE NORMAL...WITH HIGHS GENERALLY IN THE LOWER 90S AND OVERNIGHT LOWS AROUND 70 DEGREES. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 220 AM SUNDAY... SUMMERTIME SUBTROPICAL RIDGING REMAINS THE MAIN THEME OF OUR FORECAST THIS WEEK. THE UPPER RIDGE IS FORECAST TO EXPAND AND STRENGTHEN EARLY TO MID WEEK... THEN CONTRACT LATE WEEK INTO THE WEEKEND. HOWEVER... THE RIDGING IS EXPECTED TO REMAIN FIRMLY IN PLACE OVER THE SOUTHERN AND SOUTHEASTERN STATES THROUGH THE WEEK. MOISTURE... DAILY INSTABILITY... AND A LEE TROUGH/WEAKENING SURFACE COLD FRONTS (WED-THU)... THEN AGAIN TOWARD THE WEEKEND WILL PROVIDE SPARK FOR MAINLY AFTERNOON AND EARLY EVENING THUNDERSTORMS WED-SAT. SENSIBLE WEATHER WILL INCLUDE AN EXTENDED PERIOD OF HOT/HUMID WEATHER THROUGH THE WEEK. DAILY LOWS 70-75. HIGHS 90-95. THESE READINGS WILL BE AROUND 5 DEGREES ABOVE NORMAL. 20 POP TUE... WILL INCREASE TO 30-50 PERCENT DURING THE AFTERNOON AND EARLY EVENINGS WED-SAT. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... AS OF 751 PM SATURDAY... VFR CONDITIONS WILL CONTINUE THROUGH THE EVENING. LOW LEVEL MOISTURE REMAINS HIGH ACROSS THE AREA WITH LIGHT SURFACE WINDS... AND IFR CONDITIONS WITH STRATUS... AND POSSIBLY SOME PATCHY FOG.... ARE EXPECTED TO DEVELOP IN THE EARLY MORNING HOURS SUNDAY AT KRDU...KRWI...AND KFAY... WHERE DEWPOINTS ARE HIGHEST. MVFR CONDITIONS ARE POSSIBLE AT KGSO AND KINT. CONDITIONS WILL RETURN TO VFR AFTER 12Z SUNDAY... WITH A FEW SHOWERS/THUNDERSTORMS POSSIBLE IN THE AFTERNOON. OUTLOOK...A SUMMERTIME PATTERN WILL PERSIST THROUGH EARLY/MID NEXT WEEK...WITH ISOLATED TO SCATTERED AFTERNOON/EVENING CONVECTION AND A POTENTIAL FOR EARLY MORNING FOG/STRATUS. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...PWB NEAR TERM...DJF SHORT TERM...KRD LONG TERM...PWB AVIATION...SEC/KRD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1259 AM EDT SUN AUG 31 2014 .SYNOPSIS... STRENGTHENING BERMUDA HIGH PRESSURE OFFSHORE WILL BRING SUMMERTIME HEAT AND HUMIDITY THROUGH THE LABOR DAY WEEKEND WITH A FEW SHOWERS AND THUNDERSTORMS POSSIBLE. A WEAK COLD FRONT WILL APPROACH FROM THE NORTH LATE NEXT WEEK...BUT WILL LIKELY STALL BEFORE REACHING THE AREA. BERMUDA HIGH PRESSURE AND A PIEDMONT TROUGH WILL REMAIN THE DOMINANT FEATURES INTO NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 100 AM SATURDAY...NO SIGNIFICANT CHANGES ARE NEEDED TO THE FORECAST. PREVIOUS DISCUSSION FROM 1000 PM FOLLOWS... MUCH LIKE THE PAST COUPLE OF NIGHTS...A FEW SHOWERS HAVE BEGUN TO DEVELOP OFFSHORE. SOME OF THE HIGHER RESOLUTION MODELS ARE SHOWING THESE SHOWERS FLIRTING WITH THE IMMEDIATE COAST OVERNIGHT. GIVEN THE PREVAILING SOUTHERLY FLOW...THE HIGHEST RISK FOR SHOWERS WILL BE ACROSS BRUNSWICK COUNTY AND THE SOUTHERN PORTIONS OF NEW HANOVER COUNTY. WILL INCLUDE PATCHY LATE NIGHT FOG ACROSS MOST OF THE AREA... GREATEST COVERAGE IS EXPECTED AWAY FROM THE IMMEDIATE COAST WHERE MIXING WILL BE LEAST. MUCH LIKE LAST NIGHT...EXPECT A FOG AND STRATUS MIX LATE. HIGH LEVEL CONVECTIVE DEBRIS CLOUDINESS WILL CONTINUE TO SPILL ACROSS THE FORECAST AREA. THESE CLOUDS ARE FROM UPSTREAM CONVECTION AND WILL BE MAINLY THIN ACROSS THE EASTERN CAROLINAS OVERNIGHT. LIGHT TO CLAM WINDS AND ONLY A HINT OF A WEAK NOCTURNAL JET SHOULD ALLOW FOR AT LEAST SOME RADIATIONAL COOLING. DID NOT STRAY TOO FAR FROM THE LOWS OF SAT...WHICH WILL PUT MOST LOCATIONS IN THE LOWER TO MID 70S OVERNIGHT. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... AS OF 330 PM SATURDAY...MODELS REMAIN SIMILAR AND VIGILANT WITH REGARD TO KEEPING RIDGING ALOFT ACROSS THE FORECAST AREA THRU-OUT THE SHORT TERM PERIOD. SOME FLATTENING DOES OCCUR DURING LATE IN THE SHORT TERM PERIOD AS SUCCESSIVE MID-UPPER LEVEL S/W TROFS PUSH BASICALLY FROM WEST TO EAST ACROSS THE U.S....WITH THE BEST DYNAMICS ASSOCIATED WITH EACH OF THEM REMAINING NORTH OF THE FA. NEVERTHELESS...WITH TIME...THEY DO PARTIALLY ERODE THE MID-UPPER RIDGING ACROSS THE FA BY DAYBREAK TUE. AT THE SFC...THE STALLED E-W ORIENTED FRONTAL BOUNDARY ACROSS CENTRAL NC...WILL SLOWLY DISSIPATE AS IT RETURNS BACK TO THE NORTH DURING THIS PERIOD. THE RIDGE AXIS EXTENDING FROM THE 1025+ WESTERN ATLANTIC HIGH...WILL BECOME THE DOMINATE WX FEATURE TO AFFECT THE EASTERN CAROLINAS MONDAY THRU TUESDAY. IN ADDITION...THE PIEDMONT TROF ACROSS THE CENTRAL CAROLINAS WILL BECOME MORE PREVALENT BY LABOR DAY AND BEYOND. AS FOR PCPN CHANCES...THE AFTERNOON/EVENING SEA BREEZE AND PREVALENT PIEDMONT TROF WILL PROVIDE THE FORCING FOR DIURNALLY DRIVEN CONVECTION BOTH DAYS. MODELS DO INDICATE A BETTER DEFINED PIEDMONT TROF BY MONDAY AND THUS THE OVERALL POP SCHEME WILL BE ADVERTISED WITH A SLIGHTLY HIGHER CHANCE MONDAY OVER SUNDAY. LATEST SREF ALSO INDICATE A HIGHER POP FOR MONDAY OVER TUE. SEE NO REASON TO GO AGAINST THIS LAYOUT OF POPS. AS FOR DAILY MAX AND MIN TEMPS...WILL STAY CLOSER TO THE NAM MOS GUIDANCE DUE TO ITS BETTER PERFORMANCE THE PAST 5 DAYS WHEN COMPARED TO THE OTHER AVBL MODEL MOS GUIDANCE. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 330 PM SATURDAY...MID TO UPPER RIDGE HOLDING ON OVER SOUTHERN CONUS WHILE SHORTWAVES RIDE BY IN NORTHERN STREAM FLOW. THESE SHORTWAVES WILL DRIVE A FEW COLD FRONTS EAST BUT TRAILING END SHOULD REMAIN NORTH OF LOCAL AREA. THESE BOUNDARIES MAY MOVE CLOSE ENOUGH TO AFFECT THE WINDS OR PRODUCE SOME DRIER AIR TO MOVE IN ALOFT. OVERALL BERMUDA HIGH PRESSURE TO THE EAST AND PIEDMONT TROUGH TO THE WEST WILL REMAIN THE MAIN PLAYERS THROUGH THE WEEK...MAINTAINING A WARM HUMID AIR MASS. EXPECT LOCALIZED CONVECTION POSSIBLE EACH DAY WITH FOCUS ALONG SEA BREEZE BOUNDARY AND PIEDMONT TROUGH INLAND. A WEAK SOUTHERLY RETURN FLOW SHOULD BE ENHANCED BY SEA BREEZE EACH AFTERNOON. DEWPOINT TEMPS UP ABOVE 70 WILL KEEP OVERNIGHT LOWS IN 70S AND DAYTIME HIGHS WILL REACH CLOSE TO 90 ALONG THE COAST AND INTO THE MID 90S INLAND. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 06Z...STILL EXPECT MVFR/IFR CIGS TO DEVELOP EARLY THIS MORNING WITH THE BEST CHANCES FOR IFR INLAND AT KLBT/KFLO. HAVE BACKED OFF THE FOG A BIT GIVEN THE INCREASING DEBRIS CLOUDS SPREADING INTO OUR AREA. WOULD NOT RULE OUT TEMPO IFR VSBYS INLAND...BUT MVFR SEEMS MORE LIKELY ATTM. EXPECT PERIODS OF MVFR CIGS ALONG THE COAST BEGINNING AROUND DAYBREAK...WITH THE POTENTIAL FOR SOME ISOLATED SHOWERS MOVING ONSHORE AS WELL. THE HRRR MODEL SHOWS A FEW SHOWERS SKIRTING THE COAST THIS MORNING...SO WILL MAINTAIN VCSH FOR KILM/KCRE/KMYR. THE MVFR CIGS MAY LINGER THROUGH MUCH OF THE MORNING...BUT CONDITIONS WILL IMPROVE TO VFR BY MIDDAY AND PERSIST THROUGH THE REST OF THE PERIOD. WINDS WILL BE SOUTH 6-10 KT DURING THE DAY...POSSIBLY A BIT HIGHER ALONG THE COAST. COULD SEE SOME ISOLATED SHOWERS ALONG THE SEABREEZE FONT IN THE AFTN...BUT CONFIDENCE IN TIMING/LOCATION IS TOO LOW TO MENTION IN THE TAFS. EXTENDED OUTLOOK...INCREASING CHANCES FOR AFTN SHOWERS/TSTMS MONDAY THROUGH THURSDAY WITH BRIEF AND LOCALIZED PERIODS OF MVFR POSSIBLE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 100 AM SUNDAY...TWO MINOR CHANGES HAVE BEEN MADE TO THE FORECAST WITH THIS EARLY MORNING NEAR-TERM UPDATE. THE FIRST WAS TO TRIM BACK SEA HEIGHT FORECASTS BASED ON LATEST BUOY DATA SHOWING NOTHING HIGHER THAN 2 FEET NEAR OR OFFSHORE. THE OTHER CHANGE WAS TO INDICATE IN THE HIGH-RESOLUTION GRIDDED FORECAST A WEAK LANDBREEZE DEVELOPING JUST BEFORE DAYBREAK WITH LIGHT NORTH TO NORTHWEST WINDS NEAR THE BEACHES. PREVIOUS DISCUSSION FROM 1000 PM FOLLOWS... HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL KEEP A SOUTHERLY FLOW ACROSS THE WATERS OVERNIGHT...UP TO AROUND 10 KT. SEAS WILL REMAIN NEAR 3 FT. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 330 PM SATURDAY...THE SFC PRESSURE PATTERN FOR BOTH SUNDAY AND LABOR DAY ILLUSTRATE THE RIDGE AXIS EXTENDING FROM THE WESTERN ATLANTIC HIGH WILL REMAIN JUST SOUTH OF THE LOCAL WATERS. THIS POSITIONING WILL RESULT WITH A SOUTH TO SOUTHWEST WIND DIRECTION ACROSS THE WATERS...AND POSSIBLY BECOMING MORE WSW LATE IN THE PERIOD. THE SFC PG WILL SLOWLY TIGHTEN-SOME ACROSS THE LOCAL WATERS AS THE PIEDMONT TROF ACROSS THE EASTERN CAROLINAS BECOMES BETTER ESTABLISHED. LOOK FOR WIND SPEEDS INITIALLY AROUND 10 KT AT THE START...INCREASING TO 10 TO 15 KT OR POSSIBLY A SOLID 15 KT WITH GUSTS AROUND 20 KT BY MONDAY AFTN AND NIGHT. A DECENT SEA BREEZE CIRCULATION WILL SETUP EACH AFTN AND EVENG...AFFECTING THE NEARSHORE WATERS WITHIN 10 NM FROM THE COAST WITH HIGHER WIND SPEEDS. SIGNIFICANT SEAS WILL RUN A SOLID 2 TO 3 FT...WITH 4 FOOTERS NOT OUT OF THE QUESTION DURING THE PEAK OF THE SEA BREEZE EACH DAY...BUT MORE-SO DURING MONDAY AFTN AND NIGHT DUE TO SOLID SYNOPTIC WINDS AROUND 15 KT. A SOLID 2 FOOT EASTERLY GROUND SWELL EXHIBITING 8 TO 10 SECOND PERIODS...WILL INITIALLY DOMINATE THE SIGNIFICANT SEAS EARLY IN THE PERIOD. BUT AS SYNOPTIC AND MESOSCALE DRIVEN WINDS INCREASE ACROSS THE AREA WATERS...LOOK FOR AN INCREASE TO THE LOCALLY PRODUCED WIND WAVES TO COMBINE WITH THE GROUND SWELL AND PRODUCE THOSE 4 FOOTERS BY LATE IN THIS SHORT TERM PERIOD. LONG TERM /TUESDAY THROUGH THURSDAY/... AS OF 330 PM SATURDAY...BERMUDA HIGH OFF SHORE AND PIEDMONT TROUGH INLAND WILL MAINTAIN A PERSISTENT LIGHT SOUTHERLY RETURN FLOW THROUGH MUCH OF THE WEEK AROUND 10 TO 15 KTS. THE FLOW WILL BE ENHANCED BY THE SEA BREEZE EACH AFTN. THE WEAK SOUTHERLY PUSH WILL KEEP SEAS 1 TO 3 FT WITH A SLIGHT CHOP EACH AFTN. WINDS MAY LIGHTEN FURTHER TO LESS THAN 10 KTS BY THURS WITH A FURTHER DROP IN SEAS DOWN TO 2 FT OR LESS && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...RJD/TRA SHORT TERM...DCH LONG TERM...RGZ AVIATION...BJR/TRA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1235 PM CDT SUN AUG 31 2014 .UPDATE... ISSUED AT 1227 PM CDT SUN AUG 31 2014 BROAD AREA OF PRECIPITATION HAS PUSHED OFF TO THE EAST. OF TO THE WEST...SHOWERS ARE STARTING TO RE-DEVELOP WITH THE NEXT WAVE PUSHING THROUGH BROAD CYCLONIC FLOW. WITH HIT-AND-MISS SHOWER ACTIVITY EXPECTED...HAVE BROAD BRUSHED LOW POPS FOR LATER THIS AFTERNOON. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 824 AM CDT SUN AUG 31 2014 SHOWER ACTIVITY WITH A FEW WEAK THUNDERSTORMS CONTINUES MAINLY ALONG AND EAST OF A LINE FROM JAMESTOWN TO HARVEY TO BOTTINEAU. HAVE ADJUSTED POPS ACCORDINGLY FOR THIS...AND HAVE KEPT SOME LOW POPS IN THE FAR SOUTHWEST AS SOME WEAK SHOWERS START TO DEVELOP AND MOVE INTO THAT AREA. HAVE ALSO EXPANDED PATCHY FOG COVERAGE FOR THE MORNING AS VISIBILITY HAS DROPPED OVER A VARIETY OF LOCATIONS IN WESTERN NORTH DAKOTA. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 633 AM CDT SUN AUG 31 2014 STILL GETTING SOME THUNDERSTORM REDEVELOPMENT ACROSS EAST CENTRAL NORTH DAKOTA IN STUTSMAN COUNTY. APPEARS THIS WILL TRACK EAST FOR THE NEXT FEW HOURS. AREAS OF FOG SPREADING ACROSS THE FAR NORTH. THIS WILL LAST THROUGH MID MORNING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 358 AM CDT SUN AUG 31 2014 FOCUS IN THE SHORT TERM WILL BE ON THE EXITING RAINFALL THROUGH THIS MORNING AND THE CHANCES FOR RAIN LATER TODAY. THE HRRR MODEL HAS DONE A DECENT JOB OF FORECASTING PRECIPITATION THROUGH THE NIGHT AND EARLY THIS MORNING AND POPS MIMIC THE 05 UTC HRRR PRECIPITATION AS IT PROGRESSES NORTHEAST. MOST ALL HEAVY RAIN HAS PUSHED EAST INTO EASTERN NORTH DAKOTA...HOWEVER A VERY THIN BAND OF SHOWERS IS SLOWLY MOVING EAST ACROSS WESTERN NORTH DAKOTA. AS OF 0730 UTC THE BAND DROPPED HEAVY RAIN AT THE DICKINSON AIRPORT. DO NOT EXPECT THIS BAND...AT LEAST THE HEAVY RAIN ASSOCIATED WITH IT...TO LAST MUCH LONGER INTO THE MORNING HOURS. LOOKING FORWARD TO THIS AFTERNOON AND TONIGHT MODELS AGREE ON A BROAD TROUGH SETTING UP OVER THE NORTHERN PLAINS TODAY WITH A WEAK SHORT WAVE MOVING THROUGH IN THE AFTERNOON AND NIGHT. THE 00 UTC MODELS ARE HAVING A DIFFICULT TIME NAILING DOWN WHERE THE PRECIPITATION WILL FALL EXACTLY...HOWEVER ONLY LIGHT TO MODERATE SHOWERS ARE EXPECTED. AT THE MOST EXPECTING A SOME SCATTERED SHOWERS AND A FEW RUMBLES OF THUNDER. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 358 AM CDT SUN AUG 31 2014 THE EXTENDED BEGINS WITH A COOL CYCLONIC FLOW ALOFT ACROSS THE NORTHERN PLAINS MONDAY INTO TUESDAY. THIS SHOULD AT LEAST SUPPORT SOME WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. HIGHS MONDAY AND TUESDAY WILL BE A BIT COOL IN THE UPPER 60S TO LOWER 70S. BY WEDNESDAY THE FLOW ALOFT BECOMES MORE ZONAL AS THE IN BETWEEN SHORTWAVE TROUGHS. BY THURSDAY THE GFS/ECMWF/GEM BRING THE NEXT SHORTWAVE TROUGH INTO THE NORTHERN PLAINS WHICH IS PRETTY CONSISTENT WITH THE PAST FEW MODEL RUNS. THE ECMWF/GEM ARE A BIT MORE ROBUST IN QPF FORECAST FOR NORTH DAKOTA. LIKED THE ALLBLEND VERSION OF POPS FOR WEDNESDAY NIGHT AT 30 POPS FOR NOW. AFTER THURSDAY THE FLOW ALOFT BECOMES SEPARATED BETWEEN A NORTHERN AND SOUTHERN STREAM FLOW WITH THE GFS MORE PRONOUNCED IN THE FLOW SEPARATION AROUND A CUTOFF LOW OFF THE WEST COAST. THE BASIC RESULT WILL BE A QUIET PERIOD FRIDAY INTO SATURDAY AS THE FLOW MERGES ALOFT OVER THE NORTHERN PLAINS RESULTING IN WEAK SUDSIDENCE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1227 PM CDT SUN AUG 31 2014 ISOLD -SHRA/-TSRA ARE EXPECTED THROUGH MUCH OF THE FORECAST PERIOD...THOUGH WILL REFRAIN FROM MENTIONING IN INDIVIDUAL TERMINAL FORECASTS GIVEN THE LOW PROBABILITY OF ANY VIS/CIG RESTRICTIONS. WILL MONITOR AND UPDATE AS NEEDED. MVFR CIGS WILL CONTINUE TO AFFECT THE KJMS TERMINAL THROUGH EARLY AFTERNOON. OTHERWISE...VFR CONDITIONS ARE EXPECTED. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJS SHORT TERM...MM LONG TERM...WAA AVIATION...JJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
837 AM CDT SUN AUG 31 2014 .UPDATE... ISSUED AT 824 AM CDT SUN AUG 31 2014 SHOWER ACTIVITY WITH A FEW WEAK THUNDERSTORMS CONTINUES MAINLY ALONG AND EAST OF A LINE FROM JAMESTOWN TO HARVEY TO BOTTINEAU. HAVE ADJUSTED POPS ACCORDINGLY FOR THIS...AND HAVE KEPT SOME LOW POPS IN THE FAR SOUTHWEST AS SOME WEAK SHOWERS START TO DEVELOP AND MOVE INTO THAT AREA. HAVE ALSO EXPANDED PATCHY FOG COVERAGE FOR THE MORNING AS VISIBILITY HAS DROPPED OVER A VARIETY OF LOCATIONS IN WESTERN NORTH DAKOTA. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 633 AM CDT SUN AUG 31 2014 STILL GETTING SOME THUNDERSTORM REDEVELOPMENT ACROSS EAST CENTRAL NORTH DAKOTA IN STUTSMAN COUNTY. APPEARS THIS WILL TRACK EAST FOR THE NEXT FEW HOURS. AREAS OF FOG SPREADING ACROSS THE FAR NORTH. THIS WILL LAST THROUGH MID MORNING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 358 AM CDT SUN AUG 31 2014 FOCUS IN THE SHORT TERM WILL BE ON THE EXITING RAINFALL THROUGH THIS MORNING AND THE CHANCES FOR RAIN LATER TODAY. THE HRRR MODEL HAS DONE A DECENT JOB OF FORECASTING PRECIPITATION THROUGH THE NIGHT AND EARLY THIS MORNING AND POPS MIMIC THE 05 UTC HRRR PRECIPITATION AS IT PROGRESSES NORTHEAST. MOST ALL HEAVY RAIN HAS PUSHED EAST INTO EASTERN NORTH DAKOTA...HOWEVER A VERY THIN BAND OF SHOWERS IS SLOWLY MOVING EAST ACROSS WESTERN NORTH DAKOTA. AS OF 0730 UTC THE BAND DROPPED HEAVY RAIN AT THE DICKINSON AIRPORT. DO NOT EXPECT THIS BAND...AT LEAST THE HEAVY RAIN ASSOCIATED WITH IT...TO LAST MUCH LONGER INTO THE MORNING HOURS. LOOKING FORWARD TO THIS AFTERNOON AND TONIGHT MODELS AGREE ON A BROAD TROUGH SETTING UP OVER THE NORTHERN PLAINS TODAY WITH A WEAK SHORT WAVE MOVING THROUGH IN THE AFTERNOON AND NIGHT. THE 00 UTC MODELS ARE HAVING A DIFFICULT TIME NAILING DOWN WHERE THE PRECIPITATION WILL FALL EXACTLY...HOWEVER ONLY LIGHT TO MODERATE SHOWERS ARE EXPECTED. AT THE MOST EXPECTING A SOME SCATTERED SHOWERS AND A FEW RUMBLES OF THUNDER. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 358 AM CDT SUN AUG 31 2014 THE EXTENDED BEGINS WITH A COOL CYCLONIC FLOW ALOFT ACROSS THE NORTHERN PLAINS MONDAY INTO TUESDAY. THIS SHOULD AT LEAST SUPPORT SOME WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. HIGHS MONDAY AND TUESDAY WILL BE A BIT COOL IN THE UPPER 60S TO LOWER 70S. BY WEDNESDAY THE FLOW ALOFT BECOMES MORE ZONAL AS THE IN BETWEEN SHORTWAVE TROUGHS. BY THURSDAY THE GFS/ECMWF/GEM BRING THE NEXT SHORTWAVE TROUGH INTO THE NORTHERN PLAINS WHICH IS PRETTY CONSISTENT WITH THE PAST FEW MODEL RUNS. THE ECMWF/GEM ARE A BIT MORE ROBUST IN QPF FORECAST FOR NORTH DAKOTA. LIKED THE ALLBLEND VERSION OF POPS FOR WEDNESDAY NIGHT AT 30 POPS FOR NOW. AFTER THURSDAY THE FLOW ALOFT BECOMES SEPARATED BETWEEN A NORTHERN AND SOUTHERN STREAM FLOW WITH THE GFS MORE PRONOUNCED IN THE FLOW SEPARATION AROUND A CUTOFF LOW OFF THE WEST COAST. THE BASIC RESULT WILL BE A QUIET PERIOD FRIDAY INTO SATURDAY AS THE FLOW MERGES ALOFT OVER THE NORTHERN PLAINS RESULTING IN WEAK SUDSIDENCE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 633 AM CDT SUN AUG 31 2014 FRONTAL BOUNDARY IS MOVING EAST ACROSS THE REGION THIS MORNING. ONLY KJMS IS AHEAD OF THE FRONT AND BY 18Z THE FRONT SHOULD BE PAST KJMS. LOW CLOUDS WILL STICK AROUND THROUGH THE MORNING AT KJMS...KBIS... AND KMOT PROVIDING IFR TO MVFR CONDITIONS. EXPECT CONDITIONS TO IMPROVE EARLY THIS AFTERNOON FROM WEST TO EAST. SHOWERS AND THUNDERSTORMS WILL ALSO BE POSSIBLE THROUGH THE 12Z TAF PERIOD...HOWEVER SCATTERED IN NATURE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJS SHORT TERM...MM LONG TERM...WAA AVIATION...MM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
710 AM CDT SUN AUG 31 2014 .UPDATE... ISSUED AT 705 AM CDT SUN AUG 31 2014 CONVECTION ASSOCIATED WITH MID/UPPER LEVEL CIRCULATION MOVING NORTHEAST 30KTS...WITH REDEVELOPMENT SOUTHWEST OF THE DEVILS LAKE BASIN UNDER 700 MB CAA. AREA HAS GRADUALLY SLOWED DURING THE PAST SEVERAL HOURS AS UPPER CIRCULATION APPEARS TO BE INTENSIFYING. REDEVELOPMENT APPEARS AIDED BY 850MB MOIST TRANSPORT AND 0-6KM BULK SHEAR OF 40KTS. LATEST HRRR AND 03Z HOPWRF SUPPORT THESE TRENDS THROUGH 18Z. HAVE TWEAKED POPS/WX/WINDS BASED ON CURRENT CONDITIONS AND HIGH-RES MODEL FCSTS. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 330 AM CDT SUN AUG 31 2014 FOR THE NEXT 6 TO 12 HOURS THE MAIN CONCERN IS THE CONVECTION AND RISK FOR SEVERE. AS OF 08Z A LINE OF TSRA EXTENDED FROM KDVL...KS32 TO KGWR MOVG EAST 35 KTS. THIS LINE IS MOVING INTO AN AREA OF INCREASINGLY STABLE AIR AND APPEARS TO BE OUTRUNNING THE LOWER LEVEL FORCING. THE NAM12 AND GFS40 HAD BEEN INCREASING THE BULK 0-6KM SHEAR TO NEAR 50KTS IN THE DEVILS LAKE BASIN...WHICH DOES NOT YET APPEAR TO BE THE CASE. HAVE TRIED TO TIME THE TSRA ACROSS THE CWFA THIS FIRST 12 HOURS BLENDING INHERITED FCST AND HRRR/NAM/WRF MODEL MOVEMENT. THE FIRST WAVE ASSOCIATED WITH CONVECTION MOVES EAST BY 18Z...WITH SECOND FAST WAVE MOVING INTO WY AS OF 08Z. AS THE UPPER WAVES ARE PROGRESSIVE AND THE SYNOPTIC SCALE MODELS ARE IN FAIR AGREEMENT WITH THE HIGH-RES MODELS...HAVE TRENDED THE BULK OF THE TSRA/RASH OVER THE EASTERN HALF CWFA BY 00Z. MAY HAVE HELD ON TO POPS TOO LONG POST 18Z...BUT THIS IS DIFFICULT TO ASCERTAIN ATTM. THE FCST PRESENCE OF THE LOW LEVEL BOUNDARY AND INSTABILITY 18Z- 00Z ARGUES FOR HOLDING ONTO POPS. SECOND SHORT WAVE FORECAST TO MOVE ACROSS THE SOUTHERN HALF OF THE FA 00Z TO 06Z MONDAY SO HAVE HELD ON TO CHC POPS THROUGH 06Z THEN ENDED RAIN RISK FOR MONDAY. HIGH TEMPERATURES TODAY WILL BE HIGHLY DEPENDENT ON THE CLOUD COVER...THICKNESSES ARE HIGH ENOUGH OVER THE SOUTH TO SUPPORT UPPER 70S TO LOWER 80S. HAVE USED THE LOCAL BIAS CORRECTED TEMPERATURE MODEL FOR TODAY - TUESDAY AS IT SEEMS TO HAVE SUPERIOR SKILL OF LATE. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 330 AM CDT SUN AUG 31 2014 FLOW ALOFT TURNS FLAT WEST-NORTHWEST BEHIND SECOND WAVE BUT HEIGHTS DO NOT FALL APPRECIABLY. THE NEXT SHORTWAVE AND ASSOCIATED SURFACE REFLECTION IMPACTS THE SOUTHERN CWFA MONDAY NIGHT. MODELS SUGGEST NEXT WAVE FOR TUESDAY FOCUSED MORE ALONG AND NORTH OF THE HIGHWAY 2 CORRIDOR FOR TUESDAY AFTERNOON AND EVENING...WITH ONLY CHC POPS. WEDNESDAY THROUGH SATURDAY...THE NEXT UPPER TROUGH WILL MOVE INTO THE NORTHERN ROCKIES AT THE START OF THE PERIOD...THEN MOVING OFF INTO MANITOBA BY THURSDAY. THE SFC LOW WILL MOVE BY TO OUR SOUTH AND WE SHOULD SEE PLENTY OF PRECIP WITH A BOUNDARY NEARBY...ALTHOUGH THE MODELS DIFFER ON EXACT TIMING AND PLACEMENT OF THE LOW. WILL CONTINUE TO KEEP FAIRLY HIGH POPS FOR WEDNESDAY NIGHT AND SOME LINGERING IN THE EST INTO THURSDAY AS A COLD FRONT COMES THROUGH. SFC HIGH PRESSURE BUILDING IN FOR THE END OF THE PERIOD WILL BRING DRY CONDITIONS AND COOLER TEMPERATURES. THE ECMWF AND GFS START TO DIVERGE BY SATURDAY...SO KEPT ALLBLEND POPS FOR THE TIME BEING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 636 AM CDT SUN AUG 31 2014 TYPICAL MIXTURE OF VFR/MVFR/IFR CIGS FOUND IN THE PRESENCE OF TSRA AND SHRA AS AREA OF CONVECTION MOVES NORTHEAST 30 TO 35 KTS. SFC LOW AND ASSOC WNDSHFT FCST TO MOVE TO KGFK...KFAR LINE 19Z TO 20Z...REACHING KBJI AROUND 010200Z. AFTER INITIAL CONVECTION MOVES NORTHEAST TAF SITES...EXPCT VFR CIGS AND VSBY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...EWENS SHORT TERM...EWENS LONG TERM...JR/EWENS AVIATION...EWENS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
639 AM CDT SUN AUG 31 2014 .UPDATE... ISSUED AT 633 AM CDT SUN AUG 31 2014 STILL GETTING SOME THUNDERSTORM REDEVLOPMENT ACROSS EAST CENTRAL NORTH DAKOTA IN STUTSMAN COUNTY. APPEARS THIS WILL TRACK EAST FOR THE NEXT FEW HOURS. AREAS OF FOG SPEADING ACROSS THE FAR NORTH. THIS WILL LAST THROUGH MID MORNING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 358 AM CDT SUN AUG 31 2014 FOCUS IN THE SHORT TERM WILL BE ON THE EXITING RAINFALL THROUGH THIS MORNING AND THE CHANCES FOR RAIN LATER TODAY. THE HRRR MODEL HAS DONE A DECENT JOB OF FORECASTING PRECIPITATION THROUGH THE NIGHT AND EARLY THIS MORNING AND POPS MIMIC THE 05 UTC HRRR PRECIPITATION AS IT PROGRESSES NORTHEAST. MOST ALL HEAVY RAIN HAS PUSHED EAST INTO EASTERN NORTH DAKOTA...HOWEVER A VERY THIN BAND OF SHOWERS IS SLOWLY MOVING EAST ACROSS WESTERN NORTH DAKOTA. AS OF 0730 UTC THE BAND DROPPED HEAVY RAIN AT THE DICKINSON AIRPORT. DO NOT EXPECT THIS BAND...AT LEAST THE HEAVY RAIN ASSOCIATED WITH IT...TO LAST MUCH LONGER INTO THE MORNING HOURS. LOOKING FORWARD TO THIS AFTERNOON AND TONIGHT MODELS AGREE ON A BROAD TROUGH SETTING UP OVER THE NORTHERN PLAINS TODAY WITH A WEAK SHORT WAVE MOVING THROUGH IN THE AFTERNOON AND NIGHT. THE 00 UTC MODELS ARE HAVING A DIFFICULT TIME NAILING DOWN WHERE THE PRECIPITATION WILL FALL EXACTLY...HOWEVER ONLY LIGHT TO MODERATE SHOWERS ARE EXPECTED. AT THE MOST EXPECTING A SOME SCATTERED SHOWERS AND A FEW RUMBLES OF THUNDER. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 358 AM CDT SUN AUG 31 2014 THE EXTENDED BEGINS WITH A COOL CYCLONIC FLOW ALOFT ACROSS THE NORTHERN PLAINS MONDAY INTO TUESDAY. THIS SHOULD AT LEAST SUPPORT SOME WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. HIGHS MONDAY AND TUESDAY WILL BE A BIT COOL IN THE UPPER 60S TO LOWER 70S. BY WEDNESDAY THE FLOW ALOFT BECOMES MORE ZONAL AS THE IN BETWEEN SHORTWAVE TROUGHS. BY THURSDAY THE GFS/ECMWF/GEM BRING THE NEXT SHORTWAVE TROUGH INTO THE NORTHERN PLAINS WHICH IS PRETTY CONSISTENT WITH THE PAST FEW MODEL RUNS. THE ECMWF/GEM ARE A BIT MORE ROBUST IN QPF FORECAST FOR NORTH DAKOTA. LIKED THE ALLBLEND VERSION OF POPS FOR WEDNESDAY NIGHT AT 30 POPS FOR NOW. AFTER THURSDAY THE FLOW ALOFT BECOMES SEPARATED BETWEEN A NORTHERN AND SOUTHERN STREAM FLOW WITH THE GFS MORE PRONOUNCED IN THE FLOW SEPARATION AROUND A CUTOFF LOW OFF THE WEST COAST. THE BASIC RESULT WILL BE A QUIET PERIOD FRIDAY INTO SATURDAY AS THE FLOW MERGES ALOFT OVER THE NORTHERN PLAINS RESULTING IN WEAK SUDSIDENCE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 633 AM CDT SUN AUG 31 2014 FRONTAL BOUNDARY IS MOVING EAST ACROSS THE REGION THIS MORNING. ONLY KJMS IS AHEAD OF THE FRONT AND BY 18Z THE FRONT SHOULD BE PAST KJMS. LOW CLOUDS WILL STICK AROUND THROUGH THE MORNING AT KJMS...KBIS... AND KMOT PROVIDING IFR TO MVFR CONDITIONS. EXPECT CONDITIONS TO IMPROVE EARLY THIS AFTERNOON FROM WEST TO EAST. SHOWERS AND THUNDERSTORMS WILL ALSO BE POSSIBLE THROUGH THE 12Z TAF PERIOD...HOWEVER SCATTERED IN NATURE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...MM LONG TERM...WAA AVIATION...MM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
359 AM CDT SUN AUG 31 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 358 AM CDT SUN AUG 31 2014 FOCUS IN THE SHORT TERM WILL BE ON THE EXITING RAINFALL THROUGH THIS MORNING AND THE CHANCES FOR RAIN LATER TODAY. THE HRRR MODEL HAS DONE A DECENT JOB OF FORECASTING PRECIPITATION THROUGH THE NIGHT AND EARLY THIS MORNING AND POPS MIMIC THE 05 UTC HRRR PRECIPITATION AS IT PROGRESSES NORTHEAST. MOST ALL HEAVY RAIN HAS PUSHED EAST INTO EASTERN NORTH DAKOTA...HOWEVER A VERY THIN BAND OF SHOWERS IS SLOWLY MOVING EAST ACROSS WESTERN NORTH DAKOTA. AS OF 0730 UTC THE BAND DROPPED HEAVY RAIN AT THE DICKINSON AIRPORT. DO NOT EXPECT THIS BAND...AT LEAST THE HEAVY RAIN ASSOCIATED WITH IT...TO LAST MUCH LONGER INTO THE MORNING HOURS. LOOKING FORWARD TO THIS AFTERNOON AND TONIGHT MODELS AGREE ON A BROAD TROUGH SETTING UP OVER THE NORTHERN PLAINS TODAY WITH A WEAK SHORT WAVE MOVING THROUGH IN THE AFTERNOON AND NIGHT. THE 00 UTC MODELS ARE HAVING A DIFFICULT TIME NAILING DOWN WHERE THE PRECIPITATION WILL FALL EXACTLY...HOWEVER ONLY LIGHT TO MODERATE SHOWERS ARE EXPECTED. AT THE MOST EXPECTING A SOME SCATTERED SHOWERS AND A FEW RUMBLES OF THUNDER. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 358 AM CDT SUN AUG 31 2014 THE EXTENDED BEGINS WITH A COOL CYCLONIC FLOW ALOFT ACROSS THE NORTHERN PLAINS MONDAY INTO TUESDAY. THIS SHOULD AT LEAST SUPPORT SOME WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. HIGHS MONDAY AND TUESDAY WILL BE A BIT COOL IN THE UPPER 60S TO LOWER 70S. BY WEDNESDAY THE FLOW ALOFT BECOMES MORE ZONAL AS THE IN BETWEEN SHORTWAVE TROUGHS. BY THURSDAY THE GFS/ECMWF/GEM BRING THE NEXT SHORTWAVE TROUGH INTO THE NORTHERN PLAINS WHICH IS PRETTY CONSISTENT WITH THE PAST FEW MODEL RUNS. THE ECMWF/GEM ARE A BIT MORE ROBUST IN QPF FORECAST FOR NORTH DAKOTA. LIKED THE ALLBLEND VERSION OF POPS FOR WEDNESDAY NIGHT AT 30 POPS FOR NOW. AFTER THURSDAY THE FLOW ALOFT BECOMES SEPARATED BETWEEN A NORTHERN AND SOUTHERN STREAM FLOW WITH THE GFS MORE PRONOUNCED IN THE FLOW SEPARATION AROUND A CUTOFF LOW OFF THE WEST COAST. THE BASIC RESULT WILL BE A QUIET PERIOD FRIDAY INTO SATURDAY AS THE FLOW MERGES ALOFT OVER THE NORTHERN PLAINS RESULTING IN WEAK SUDSIDENCE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1240 AM CDT SUN AUG 31 2014 0530Z A LINE OF THUNDERSTORMS WAS PROGRESSING EAST ALONG A FRONTAL BOUNDARY OVER CENTRAL NORTH DAKOTA. KMOT-KBIS-KJMS WILL INITIALLY BE IMPACTED BY THE STORMS. AFTER 08Z THE LINE WILL HAVE MOVED EAST OF KMOT-KBIS AND THEN AFTER 10Z AT KJMS. NORTHWEST FLOW MAY BRING IN SOME MVFR CEILINGS ESPECIALLY AFTER SUNRISE CENTRAL AND EAST. OTHERWISE ONLY VERY ISOLATED SHOWERS DURING THE DAY SUNDAY. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...MM LONG TERM...WAA AVIATION...WAA
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1039 PM EDT MON SEP 1 2014 .SYNOPSIS... A COLD FRONT WILL REACH THE NORTHERN OHIO VALLEY BY DAYBREAK AND CROSS THE REGION FROM THE NORTHWEST ON TUESDAY. HIGH PRESSURE WILL BRIEFLY BUILD IN BEHIND THE FRONT...WITH DRY CONDITIONS EXPECTED FOR WEDNESDAY. A RETURN TO SOUTHERLY FLOW WILL INCREASE THE THREAT FOR SHOWERS AND STORMS AT THE END OF THE WEEK...CULMINATING ON SATURDAY AS THE NEXT COLD FRONT CROSSES THE REGION. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... ONLY A FEW SHOWERS LINGERING IN THE FAR EASTERN ZONES AND THEY WILL MOVE OUT BEFORE MIDNIGHT. SHOWERS AND STORMS OCCURRING IN THE CENTRAL PLAINS WILL SPREAD EAST NORTHEAST TOWARDS THE REGION. HRRR AND RAP MODELS SHOWING SOME TIMING DISCREPANCIES. BUT IT APPEARS THAT ACTIVITY WILL NOT SPREAD INTO WESTERN ZONES UNTIL VERY LATE TONIGHT. EXPECT ANY HEAVIER RAINFALL TO CLOSER TO THE END OF THE PERIOD AND INTO TUESDAY. FORECAST LOWS LOOK REASONABLE. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... BY THE TIME DAYLIGHT HOURS OF TUESDAY ROLLS AROUND...THE SYSTEM IS EXPECTED TO SHIFT THE SW-NE AXIS MORE INTO THE CWA AND ALONG THE I-71 CORRIDOR. AREAS THAT SAW EXCESSIVE RAINFALL ON SATURDAY MAY BE HIT WITH ANOTHER SOAKER...BUT THE UNUSUALLY HIGH VALUES SHOULD NOT MAKE ANOTHER APPEARANCE...AT LEAST OVER WARREN AND GREENE COUNTIES. PRECIP DURING THE DAY OVER THE CWA WILL BE PROGRESSIVE AND EXPAND SOUTHEAST TO COVER THE REST OF CWA BY THE AFTERNOON. HIGH TEMPS WILL BE MUTED DUE TO THE RAINFALL...GENERALLY IN THE LOW 80S...SOME MID 80S ARE POSSIBLE IF THE RAIN HOLDS OFF A FEW HOURS OVER THE SOUTHEAST. HIGH PRESSURE WILL BRIEFLY FILL IN BEHIND THE COLD FRONT AND PROVIDE ENOUGH DOWNWARD MOTION TO HELP SCOUR OUT MOST OF THE CLOUD COVER AND USHER IN SOME DRIER AIR. THE DRIEST AIR AND SUBSEQUENT COOLER TEMPERATURES FOR TUESDAY NIGHT WILL BE FOUND ALONG AND NORTH OF THE I-70 CORRIDOR...WITH THE AREA EAST OF COLUMBUS GETTING THE BEST COOLING BOTH TUES AND WED NIGHTS. NORTH OF DAYTON ON WED NIGHT WILL LIKELY BE INVOLVED WITH THE RETURNING WARMER AND MORE MOIST AIR ON THE SOUTHERLY WINDS. HIGHS ON WEDNESDAY WILL REACH THE LOW TO MID 80S ACROSS THE REGION. && .LONG TERM /THURSDAY THROUGH MONDAY/... PERIOD BEGINS WITH A WEAK WARM FRONT LIFTING UP THROUGH THE WRN OHIO VALLEY. AS FRONT LIFTS UP ACROSS THE AREA THURSDAY...THERE WILL BE A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM. BY FRIDAY...A CDFNT BEGINS TO PUSH THROUGH THE GREAT LAKES. MODELS ARE SHOWING A RANGE ON THE FROPA TIMING. THE GFS IS THE QUICKEST...WHILE THE ECMWF IS ON THE SLOWER END OF THE GUIDANCE. BOTH MODELS SHOW FROPA FRIDAY NIGHT INTO SATURDAY MORNING WITH CONTINUED PCPN CHANCES ON SATURDAY. PUT THE BEST POPS FRIDAY NIGHT WITH 50 POP ACROSS THE REGION. REDEVELOPED THE PCPN SATURDAY MORNING WITH 50 POPS ACROSS THE SOUTH...BUT LOWER POPS TO THE NW. THE GFS DRIES THINGS OUT QUICKER SATURDAY NIGHT AS COMPARED TO THE ECMWF WHICH LEAVES LINGERING PCPN CHANCES INTO SATURDAY NIGHT ACROSS THE SOUTH. HELD ON TO 20 POPS FOR THE EVENING HOURS IN THE SOUTHEAST. HIGH PRESSURE BUILDS ACROSS THE REGION SUNDAY INTO MONDAY. WARM AND HUMID CONDITIONS ARE EXPECTED FOR THURSDAY AND FRIDAY. HIGHS WILL BE IN THE UPPER 80S TO 90 WITH DEWPOINTS IN THE UPPER 60S TO LOWER 70S. COOLER CONDITIONS SATURDAY WITH HIGHS RANGING FROM THE MID 70S IN THE NORTH TO THE LOWER 80S IN NRN KY. BY SUNDAY AND MONDAY...HIGHS WILL BE IN THE LOWER TO MID 70S ACROSS THE REGION. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... A MID DECK WILL SPREAD INTO THE REGION AFTER 06Z WITH SOME SHOWERS ASSOCIATED WITH IT. MORE WIDESPREAD SHOWERS AND THUNDERSTORMS WILL FOLLOW. THERE ARE SOME TIMING DISCREPANCIES IN THE NEAR TERM GUIDANCE. HAVE USED A SOMEWHAT FASTER SOLUTION WHICH WOULD BRING THE PRECIPITATION IN BEFORE 12Z. APPEARS THAT HEAVIER RAINFALL AND THUS BETTER CHANCE OF PREVAILING MVFR CEILINGS AND VISIBILITIES WILL BE AT KDAY. SHOWERS AND STORMS ARE EXPECTED TO LAST INTO THE AFTERNOON BEFORE TAPERING OFF/MOVING EAST. WINDS WILL SHIFT TO A MORE WESTERLY COMPONENT IN THE LATTER PART OF THE TAF PERIOD. OUTLOOK...MVFR TO IFR VISIBILITIES ARE POSSIBLE LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THUNDERSTORMS POSSIBLE FRIDAY INTO SATURDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...FRANKS NEAR TERM... SHORT TERM...FRANKS LONG TERM...SITES AVIATION...
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1116 AM EDT SUN AUG 31 2014 .SYNOPSIS... DEEP MOISTURE AND UPPER LEVEL DISTURBANCES PROVIDE ROUNDS OF SHOWERS AND STORMS TODAY. WEAK FRONT CROSSES TUESDAY WITH SHOWERS AND STORMS. && .NEAR TERM /THROUGH TONIGHT/... SENT A QUICK UPDATE TO ADJUST POPS ACCORDING WITH LATEST DOPPLER RADAR AND HIGH RESOLUTION MODELS. REMOVED THUNDER AT LEAST THROUGH 18Z AS THERE IS NO SIGN OF LIGHTNING UNDER AREAS OF STRATIFORM RAIN. EMBEDDED SHOWERS COULD BECOME THUNDERSTORMS THIS AFTERNOON ACROSS CENTRAL WV. THE HEAVIEST RAINFALL COULD REACH 0.5 INCHES PER HOURS. WILL KEEP MONITORING THE RAINFALL RATES THROUGH THIS AFTERNOON. PREVIOUS DISCUSSION BELOW... UPDATE... NOW HAVE EVIDENCE OF THE STRATUS DECK SHOWING UP OVER SOUTHEAST OHIO AND THE TRI STATE AREA WITH FEW/SCT SHOWING UP IN THE OBS BELOW 2500FT. REWORKED THE POPS GIVEN THE RADAR TRENDS...AND CONTINUE WITH THE QUIETER PERIOD BETWEEN 12Z AND 16Z. RAINFALL AMOUNTS OVER THE LAST 3 HOURS ARE IN THE 0.2 TO 0.3 INCH RANGE IN THE HEAVIER AMOUNTS. PREVIOUS DISCUSSION... THROUGH THE EARLY AFTERNOON/18Z TIME FRAME TODAY...LEANED HEAVILY ON THE HRRR MODEL GIVEN THAT IT HAD INITIALIZED VERY WELL. TYPICALLY LIKE THE OUTPUT OF THIS MODEL WHEN THAT HAPPENS. ALSO...SINCE THE NAM MATCHED UP FAIRLY WELL...DEFORMATION AND FRONTOGENESIS PROGS PROVED VALUABLE IN THE PATTERN OF THE POP CONSTRUCTION THIS MORNING. THIS HELPED TO ADD SOME DEFINITION TO THE PREVIOUS FORECAST...PARTICULARLY OVER THE LOWLANDS SOUTH/EAST OF THE OHIO RIVER. AXIS OF DEEP MOISTURE DEPARTS TONIGHT...ALTHOUGH MAY STILL BE HANGING ON IN THE MOUNTAINS BY 12Z MONDAY. TEMPERATURES COME DOWN SIGNIFICANTLY FOR TODAY IN THE PERIODIC RAIN. MAY NOT COME OUT OF THE 70S OVER SOUTHEAST OHIO. SOUTHERN MOUNTAIN LOCATIONS IN THE EASTERN PORTION OF THE CWA COULD END UP WARMER THAN THE OHIO RIVER SITES. THE MAV GUIDANCE HAS BEEN HANDS DOWN BETTER THAN THE OTHERS AND LEANED ON THIS...BUT ALWAYS A LITTLE HESITANT IN A DIFFERENT ATMOSPHERE. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... MODELS AGREE OUR AREA WILL BE BETWEEN TWO SIGNIFICANT SYSTEMS ON MONDAY. WHILE DYNAMICS WILL BE AT A MINIMUM...A WARM AND HUMID AIRMASS WILL CONTINUE FOR A THREAT OF SCATTERED AFTERNOON STORMS MONDAY...AND MORE SUNSHINE WILL LEAD TO HIGH TEMPERATURES IN THE MID TO UPPER 80S. WITH LOSS OF HEATING...ANY CONVECTION WILL DISSIPATE QUICKLY EARLY MONDAY EVENING. IT WILL REMAIN MOSTLY PRECIP FREE MONDAY NIGHT BEFORE THE NEXT SYSTEM IN THE FORM OF ANOTHER UPPER TROUGH AND ASSOCIATED COOL FRONT AFFECT US TUESDAY. MODELS HAVE THE UPPER TROUGH PROGRESSING EASTWARD ACROSS OUR AREA TUESDAY AND EARLY TUESDAY NIGHT WITH A BAND OF SHOWERS AND STORMS. SO HIGH POPS PROGRESSING FROM NORTHWEST TO SOUTHEAST TUESDAY INTO EARLY TUESDAY NIGHT ARE IN ORDER. WHILE THE UPPER TROUGH EXITS TUESDAY NIGHT...THE COOL FRONT WILL LOSE DEFINITION AS IT CROSSES THE AREA...AND GRADUALLY BE REPLACED BY WEAK HIGH PRESSURE LATER TUESDAY NIGHT AND WEDNESDAY. HEIGHTS RISE MODESTLY BEHIND THE UPPER TROUGH...BUT MODELS STILL INDICATE ENOUGH MOISTURE AND INSTABILITY IN THE FAR SOUTH FOR A SHOWER OR TWO TO CONTINUE INTO WEDNESDAY. LOOK FOR HIGH TEMPERATURES TO STAY IN THE 80S FOR TUESDAY AND WEDNESDAY...BUT WITH SOME DRIER AIR FILTERING INTO THE NORTH TUESDAY NIGHT AND WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... LONG TERM PERIOD CAN GENERALLY BE CHARACTERIZED BY ZONAL FLOW ALOFT. LEANED WPC FOR THE MOST PART WITH A FEW TWEAKS HERE AND THERE. WARM AND MUGGY CONDITIONS WILL CONTINUE THROUGH THE PERIOD...WITH NO HEAT WAVES OR ABNORMALLY COOL SPELLS IN SIGHT. A COLD FRONT WILL PUSH ACROSS TUE NIGHT WITH ANOTHER FRONT APPROACHING SAT NIGHT...WITH SUBSEQUENT HIGHER POPS DURING THOSE PERIODS. IN BETWEEN...THURSDAY AND FRIDAY LOOK MOSTLY SUNNY TO PERHAPS PARTLY CLOUDY WITH ONLY MINIMAL CHANCES FOR PRECIP EACH DAY. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... VFR CONDITIONS WILL PREVAIL ACROSS MOST SITES THROUGH 18Z. THE EXCEPTION WILL BE MVFR UNDER LIGHT RAIN POSSIBLE AT HTS...TO MOVE OVER CRW BY 18-20Z. CONVECTION WILL INCREASE IN INTENSITY ACROSS CENTRAL WV THIS AFTERNOON. INCLUDED TSRA FOR CRW...CKB...AND BKW...AND VCTS/CB FOR THE REST OF SITES AFTER 18Z. EXPECT AND EXTENSIVE LOW STRATUS DECK TO SET UP THIS EVENING AS THE DEEPER MOISTURE PUSHES NORTHEASTWARD. AS THOSE CEILINGS COME DOWN...FEEL THE VISIBILITIES CAN COME DOWN AS WELL WITH THE RECENT RAIN. NO LIFR FOG DUE TO LIGHT WINDS OVERNIGHT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING AND EXTENT OF TSRA THIS AFTERNOON MAY VARY. EXTEND OF POST RAIN AND SUBSIDENCE OF LOW STRATUS COULD VARY FROM SITE TO SITE. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H M M M M M M M M M BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H M M PKB CONSISTENCY M H H H H H H H M M M M CKB CONSISTENCY M H H H H H M M M M M M AFTER 12Z MONDAY... IFR IN DENSE EARLY MORNING VALLEY FOG EARLY NEXT WEEK. IFR IN SHOWERS AND STORMS POSSIBLE WITH THE COLD FRONT TUESDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/26 NEAR TERM...ARJ/26 SHORT TERM...JMV LONG TERM...50 AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
640 AM EDT SUN AUG 31 2014 .SYNOPSIS... DEEP MOISTURE AND UPPER LEVEL DISTURBANCES PROVIDE ROUNDS OF SHOWERS AND STORMS TODAY. WEAK FRONT CROSSES TUESDAY WITH SHOWERS AND STORMS. && .NEAR TERM /THROUGH TONIGHT/... UPDATE... NOW HAVE EVIDENCE OF THE STRATUS DECK SHOWING UP OVER SOUTHEAST OHIO AND THE TRI STATE AREA WITH FEW/SCT SHOWING UP IN THE OBS BELOW 2500FT. REWORKED THE POPS GIVEN THE RADAR TRENDS...AND CONTINUE WITH THE QUIETER PERIOD BETWEEN 12Z AND 16Z. RAINFALL AMOUNTS OVER THE LAST 3 HOURS ARE IN THE 0.2 TO 0.3 INCH RANGE IN THE HEAVIER AMOUNTS. PREVIOUS DISCUSSION... THROUGH THE EARLY AFTERNOON/18Z TIME FRAME TODAY...LEANED HEAVILY ON THE HRRR MODEL GIVEN THAT IT HAD INITIALIZED VERY WELL. TYPICALLY LIKE THE OUTPUT OF THIS MODEL WHEN THAT HAPPENS. ALSO...SINCE THE NAM MATCHED UP FAIRLY WELL...DEFORMATION AND FRONTOGENESIS PROGS PROVED VALUABLE IN THE PATTERN OF THE POP CONSTRUCTION THIS MORNING. THIS HELPED TO ADD SOME DEFINITION TO THE PREVIOUS FORECAST...PARTICULARLY OVER THE LOWLANDS SOUTH/EAST OF THE OHIO RIVER. AXIS OF DEEP MOISTURE DEPARTS TONIGHT...ALTHOUGH MAY STILL BE HANGING ON IN THE MOUNTAINS BY 12Z MONDAY. TEMPERATURES COME DOWN SIGNIFICANTLY FOR TODAY IN THE PERIODIC RAIN. MAY NOT COME OUT OF THE 70S OVER SOUTHEAST OHIO. SOUTHERN MOUNTAIN LOCATIONS IN THE EASTERN PORTION OF THE CWA COULD END UP WARMER THAN THE OHIO RIVER SITES. THE MAV GUIDANCE HAS BEEN HANDS DOWN BETTER THAN THE OTHERS AND LEANED ON THIS...BUT ALWAYS A LITTLE HESITANT IN A DIFFERENT ATMOSPHERE. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... MODELS AGREE OUR AREA WILL BE BETWEEN TWO SIGNIFICANT SYSTEMS ON MONDAY. WHILE DYNAMICS WILL BE AT A MINIMUM...A WARM AND HUMID AIRMASS WILL CONTINUE FOR A THREAT OF SCATTERED AFTERNOON STORMS MONDAY...AND MORE SUNSHINE WILL LEAD TO HIGH TEMPERATURES IN THE MID TO UPPER 80S. WITH LOSS OF HEATING...ANY CONVECTION WILL DISSIPATE QUICKLY EARLY MONDAY EVENING. IT WILL REMAIN MOSTLY PRECIP FREE MONDAY NIGHT BEFORE THE NEXT SYSTEM IN THE FORM OF ANOTHER UPPER TROUGH AND ASSOCIATED COOL FRONT AFFECT US TUESDAY. MODELS HAVE THE UPPER TROUGH PROGRESSING EASTWARD ACROSS OUR AREA TUESDAY AND EARLY TUESDAY NIGHT WITH A BAND OF SHOWERS AND STORMS. SO HIGH POPS PROGRESSING FROM NORTHWEST TO SOUTHEAST TUESDAY INTO EARLY TUESDAY NIGHT ARE IN ORDER. WHILE THE UPPER TROUGH EXITS TUESDAY NIGHT...THE COOL FRONT WILL LOSE DEFINITION AS IT CROSSES THE AREA...AND GRADUALLY BE REPLACED BY WEAK HIGH PRESSURE LATER TUESDAY NIGHT AND WEDNESDAY. HEIGHTS RISE MODESTLY BEHIND THE UPPER TROUGH...BUT MODELS STILL INDICATE ENOUGH MOISTURE AND INSTABILITY IN THE FAR SOUTH FOR A SHOWER OR TWO TO CONTINUE INTO WEDNESDAY. LOOK FOR HIGH TEMPERATURES TO STAY IN THE 80S FOR TUESDAY AND WEDNESDAY...BUT WITH SOME DRIER AIR FILTERING INTO THE NORTH TUESDAY NIGHT AND WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... LONG TERM PERIOD CAN GENERALLY BE CHARACTERIZED BY ZONAL FLOW ALOFT. LEANED WPC FOR THE MOST PART WITH A FEW TWEAKS HERE AND THERE. WARM AND MUGGY CONDITIONS WILL CONTINUE THROUGH THE PERIOD...WITH NO HEAT WAVES OR ABNORMALLY COOL SPELLS IN SIGHT. A COLD FRONT WILL PUSH ACROSS TUE NIGHT WITH ANOTHER FRONT APPROACHING SAT NIGHT...WITH SUBSEQUENT HIGHER POPS DURING THOSE PERIODS. IN BETWEEN...THURSDAY AND FRIDAY LOOK MOSTLY SUNNY TO PERHAPS PARTLY CLOUDY WITH ONLY MINIMAL CHANCES FOR PRECIP EACH DAY. && .AVIATION /10Z SUNDAY THROUGH THURSDAY/... NOW SEEING THE DEVELOPMENT OF THE EXPECTED MVFR/IFR STRATUS DECK BACK IN OHIO TOWARDS THE NORTHERN PANHANDLE. WILL BE WATCHING UNI AND THEN THE RIVER TERMINALS OF PKB AND HTS TO DO THE SAME AND CARRY THIS IN THE TAFS THIS MORNING. AFTER A LULL IN THE CONVECTION THIS MORNING...EXPECT IT TO PICK UP THIS AFTERNOON. CARRYING VCTS/CB IN THE TAFS RIGHT NOW AS THE BANDS OF SHOWERS AND STORMS PASS THROUGH THE AREA. BEST CHANCE FOR THE CONVECTION IS WEST OF THE MOUNTAINS AND IN THE OHIO VALLEY. THIS DOES NOT MEAN THUNDER CHANCES ARE RELEGATED TO THESE AREAS HOWEVER. EXPECT AND EXTENSIVE LOW STRATUS DECK TO SET UP THIS EVENING AS THE DEEPER MOISTURE PUSHES NORTHEASTWARD. AS THOSE CEILINGS COME DOWN...FEEL THE VISIBILITIES CAN COME DOWN AS WELL WITH THE RECENT RAIN. NO LIFR FOG DUE TO LIGHT WINDS OVERNIGHT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING AND EXTENT OF TSRA IS IN QUESTION. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22 EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18 CRW CONSISTENCY L L L M H H H M M M H M HTS CONSISTENCY L L L M H M M M M M M M BKW CONSISTENCY M M M H H H H H H H H H EKN CONSISTENCY L L L M H H H H H H H H PKB CONSISTENCY L L L L M M H H H H H M CKB CONSISTENCY L L L L M M H H H M M M AFTER 12Z MONDAY... IFR IN DENSE EARLY MORNING VALLEY FOG EARLY NEXT WEEK. IFR IN SHOWERS AND STORMS POSSIBLE WITH THE COLD FRONT TUESDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/26 NEAR TERM...26 SHORT TERM...JMV LONG TERM...50 AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
329 AM EDT SUN AUG 31 2014 .SYNOPSIS... DEEP MOISTURE AND UPPER LEVEL DISTURBANCES PROVIDE ROUNDS OF SHOWERS AND STORMS TODAY. WEAK FRONT CROSSES TUESDAY WITH SHOWERS AND STORMS. && .NEAR TERM /THROUGH TONIGHT/... THROUGH THE EARLY AFTERNOON/18Z TIME FRAME TODAY...LEANED HEAVILY ON THE HRRR MODEL GIVEN THAT IT HAD INITIALIZED VERY WELL. TYPICALLY LIKE THE OUTPUT OF THIS MODEL WHEN THAT HAPPENS. ALSO...SINCE THE NAM MATCHED UP FAIRLY WELL...DEFORMATION AND FRONTOGENESIS PROGS PROVED VALUABLE IN THE PATTERN OF THE POP CONSTRUCTION THIS MORNING. THIS HELPED TO ADD SOME DEFINITION TO THE PREVIOUS FORECAST...PARTICULARLY OVER THE LOWLANDS SOUTH/EAST OF THE OHIO RIVER. AXIS OF DEEP MOISTURE DEPARTS TONIGHT...ALTHOUGH MAY STILL BE HANGING ON IN THE MOUNTAINS BY 12Z MONDAY. TEMPERATURES COME DOWN SIGNIFICANTLY FOR TODAY IN THE PERIODIC RAIN. MAY NOT COME OUT OF THE 70S OVER SOUTHEAST OHIO. SOUTHERN MOUNTAIN LOCATIONS IN THE EASTERN PORTION OF THE CWA COULD END UP WARMER THAN THE OHIO RIVER SITES. THE MAV GUIDANCE HAS BEEN HANDS DOWN BETTER THAN THE OTHERS AND LEANED ON THIS...BUT ALWAYS A LITTLE HESITANT IN A DIFFERENT ATMOSPHERE. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... MODELS AGREE OUR AREA WILL BE BETWEEN TWO SIGNIFICANT SYSTEMS ON MONDAY. WHILE DYNAMICS WILL BE AT A MINIMUM...A WARM AND HUMID AIRMASS WILL CONTINUE FOR A THREAT OF SCATTERED AFTERNOON STORMS MONDAY...AND MORE SUNSHINE WILL LEAD TO HIGH TEMPERATURES IN THE MID TO UPPER 80S. WITH LOSS OF HEATING...ANY CONVECTION WILL DISSIPATE QUICKLY EARLY MONDAY EVENING. IT WILL REMAIN MOSTLY PRECIP FREE MONDAY NIGHT BEFORE THE NEXT SYSTEM IN THE FORM OF ANOTHER UPPER TROUGH AND ASSOCIATED COOL FRONT AFFECT US TUESDAY. MODELS HAVE THE UPPER TROUGH PROGRESSING EASTWARD ACROSS OUR AREA TUESDAY AND EARLY TUESDAY NIGHT WITH A BAND OF SHOWERS AND STORMS. SO HIGH POPS PROGRESSING FROM NORTHWEST TO SOUTHEAST TUESDAY INTO EARLY TUESDAY NIGHT ARE IN ORDER. WHILE THE UPPER TROUGH EXITS TUESDAY NIGHT...THE COOL FRONT WILL LOSE DEFINITION AS IT CROSSES THE AREA...AND GRADUALLY BE REPLACED BY WEAK HIGH PRESSURE LATER TUESDAY NIGHT AND WEDNESDAY. HEIGHTS RISE MODESTLY BEHIND THE UPPER TROUGH...BUT MODELS STILL INDICATE ENOUGH MOISTURE AND INSTABILITY IN THE FAR SOUTH FOR A SHOWER OR TWO TO CONTINUE INTO WEDNESDAY. LOOK FOR HIGH TEMPERATURES TO STAY IN THE 80S FOR TUESDAY AND WEDNESDAY...BUT WITH SOME DRIER AIR FILTERING INTO THE NORTH TUESDAY NIGHT AND WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... LONG TERM PERIOD CAN GENERALLY BE CHARACTERIZED BY ZONAL FLOW ALOFT. LEANED WPC FOR THE MOST PART WITH A FEW TWEAKS HERE AND THERE. WARM AND MUGGY CONDITIONS WILL CONTINUE THROUGH THE PERIOD...WITH NO HEAT WAVES OR ABNORMALLY COOL SPELLS IN SIGHT. A COLD FRONT WILL PUSH ACROSS TUE NIGHT WITH ANOTHER FRONT APPROACHING SAT NIGHT...WITH SUBSEQUENT HIGHER POPS DURING THOSE PERIODS. IN BETWEEN...THURSDAY AND FRIDAY LOOK MOSTLY SUNNY TO PERHAPS PARTLY CLOUDY WITH ONLY MINIMAL CHANCES FOR PRECIP EACH DAY. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... VERY COMPLEX TAFS TODAY GIVEN THE UNSETTLED SURFACE AND UPPER LEVEL CONDITIONS BRINGING SHOWERS WITH A FEW EMBEDDED STORMS THROUGH THE PERIOD. TRIED TO USE AS MUCH PREVAILING SHRA AS POSSIBLE...AND ALSO TRIED TO PEG THE BEST CHANCES FOR TSRA WITH PEAK HEATING TODAY UTILIZING THE PROB30 WORDING IN THE TAFS. THIS TIMING HAS A LOWER CONFIDENCE ATTACHED TO IT. AFTER THE INITIAL WAVE OF RAIN EXITS THE OHIO VALLEY...EXPECT AN MVFR STRATUS LAYER TO DEVELOP TOWARDS DAWN. THIS COULD LIMIT THUNDER CHANCES UNTIL THIS LAYER DISSOLVES...AND WILL MAINLY AFFECT PKB AND HTS. LATER TONIGHT...AS THE CEILINGS LOWER AGAIN AFTER THE MAIN BATCH OF RAIN MOVES INTO THE MOUNTAINS...EXPECT CEILINGS TO LOWER. AS THIS HAPPENS THE CHANCES FOR VISIBILITIES TO LOWER INCREASE AS WELL. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z MONDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING AND EXTENT OF TSRA IS IN QUESTION. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE SUN 08/31/14 UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19 EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15 CRW CONSISTENCY M M L L L L M H H H H H HTS CONSISTENCY M M M L L L M M M H H M BKW CONSISTENCY M M M M M M M H H H H H EKN CONSISTENCY L L L L L L M H H H H H PKB CONSISTENCY M M M L L L L L L H H H CKB CONSISTENCY M M M L L L L L L M H H AFTER 06Z MONDAY... IFR IN DENSE EARLY MORNING VALLEY FOG EARLY NEXT WEEK. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/26 NEAR TERM...26 SHORT TERM...JMV LONG TERM...50 AVIATION...26
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
158 AM EDT SUN AUG 31 2014 .SYNOPSIS... A WEAK COLD FRONT OVER THE GREAT LAKES WILL BECOME STATIONARY ON SUNDAY JUST NORTH OF LAKE ERIE. AN AREA OF LOW PRESSURE OVER THE GULF COAST STATES WILL MOVE NORTHEAST UP THE APPALACHIANS OVERNIGHT AND SUNDAY. A STRONGER COLD FRONT WILL MOVE FROM THE NORTHERN PLAINS AND CROSS THE AREA ON TUESDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... BAND OF SHOWERS CONTINUE TO MOVE NORTHEAST ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA IN ASSOCIATION WITH UPPER LEVEL POSITIVE VORTICITY ADVECTION. MORE ACTIVE ACTIVITY ACROSS SOUTHERN OHIO SHOULD LIFT NORTHEAST INTO THE REGION OVERNIGHT BUT SHOULD ALSO WEAKEN TO JUST SHOWERS. FURTHER WEST...A LINE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO ADVANCE EAST WITH THE COLD FRONT. LATEST HRRR GUIDANCE SUGGESTS LINE WILL WEAKEN BY THE TIME IT REACHES OUR AREA. THIS SEEMS LOGICAL SINCE THERE IS A LOT OF CIN OVER THE REGION AT THIS TIME TO OVERCOME. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/... A WARM...MUGGY AND UNSETTLED AIR MASS WILL LINGER OVER THE AREA MOST OF THE PERIOD. UNSEASONABLY WARM SURFACE DEW POINTS WILL MAKE IT FEEL MORE LIKE JULY THAN LABOR DAY WEEKEND. MODELS CONTINUE TO HAVE DIFFICULTY PIN POINTING PRECIP CHANCES. IT DOES APPEAR THAT BEST CHANCES FOR PRECIP ON SUNDAY WILL BE ACROSS THE SOUTHEAST HALF OF THE AREA. FURTHER NORTH WEAK HIGH PRESSURE WILL BRIEFLY BUILD OVER LAKE ERIE IN THE WAKE OF THE SURFACE LOW MOVING THROUGH NOW. BY SUNDAY EVENING THE THREAT FOR PRECIP SHOULD BE OVER ALL AREAS. ANOTHER LOW OVER THE PLAINS WILL LIFT A WARM FRONT BACK ACROSS THE AREA ON MONDAY. THE MODELS ARE IN A LITTLE BIT BETTER AGREEMENT WITH THIS SYSTEM. WILL NEED ANOTHER PERIOD OF LIKELY OR HIGHER WORDING FROM LATE MONDAY TILL A COLD FRONT CROSSES THE REGION ON TUESDAY. PRECIP CHANCES WILL DIMINISH BY TUESDAY EVENING. THE FRONTAL PASSAGE WON`T BE STRONG ENOUGH TO BRING A COMPLETE AIR MASS CHANGE BUT SURFACE DEW POINTS SHOULD DIP INTO THE LOWER 60S. SUNDAY WILL BE THE COOLEST DAY OF THE PERIOD WITH THE PRECIP ACROSS THE AREA. THE REMAINDER OF THE PERIOD WILL BE ABOVE NORMAL AND HAVE USED A BLEND OF GUIDANCE. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... UPPER RIDGE BUILDS IN FROM THE SOUTH BEHIND EXITING TROUGH ON WEDNESDAY. WITH INFLUENCE OF THE RIDGE IN WEAK FLOW PATTER MOST CONVECTION WILL BE SUPPRESSED. CAN`T COMPLETELY RULE OUT TSRA BUT FOR NOW WILL KEEP A SMALL POP IN THROUGH FRIDAY. THE MODELS ARE IN FAIRLY STRONG AGREEMENT THAT THE RIDGE WILL LEAD TO H850 TEMPS 18-20C FOR LATE IN THE WEEK. THIS MAKES IT DIFFICULT TO LEAN TOWARDS THE MUCH COOLER CLIMATOLOGY (UPPER 70S) FOR THU-SAT...SO HAVE TRENDED CLOSER TO THE MODEL GUIDANCE MID 80S. THE MOISTURE ADVECTION IS NOT AS FAVORABLE AS IT WAS WITH THE CURRENT WEATHER PATTERN...SO DESPITE HIGH SFC DEW POINTS THE OVERALL PRECIPITABLE WATER VALUES FOR THE AIR COLUMN WILL BE LOWER IN THE 1.5" RANGE. THIS WILL AGAIN SUPPORT A LOWER CHANCE FOR PRECIPITATION. THE TIMING ON THE FRONT WHICH WILL BRING THE WARM WEATHER TO AN END IS LOOKING MORE LIKE LATE SATURDAY WHICH SHOULD BRING BETTER CHANCES OF THUNDERSTORMS. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... THE FLOW IS SOUTHWEST AHEAD OF THE COLD FRONT THAT IS WELL NORTH OF LAKE ERIE. THE FRONT WILL REMAIN WELL NORTH OF THE AREA THROUGH THE TAF PERIOD. HOWEVER...PLENTY OF MOISTURE IN THIS FLOW WILL CAUSE MAINLY SHOWERS AT THE TAF SITES THROUGH EARLY AFTERNOON AND THEN A DECREASE IN SHOWERS. SOME THUNDERSTORMS ARE POSSIBLE. THE THUNDERSTORMS OVER CENTRAL INDIANA ARE EXPECTED TO DECREASE. VFR CONDITIONS TO START AND THEN MVFR CEILINGS WILL DEVELOP BY DAYBREAK ALONG WITH SOME MVFR VISIBILITIES. PLENTY OF LOW LEVEL MOISTURE SO SOME IFR CEILINGS ARE ALSO POSSIBLE MAINLY BETWEEN DAYBREAK AND EARLY AFTERNOON. CONFIDENCE IS AROUND 60% THAT SOME IFR CEILINGS WILL DEVELOP. OUTLOOK...NON VFR LIKELY AT TIMES IN SHOWERS AND THUNDERSTORMS THROUGH TUESDAY. && .MARINE... LOW LEVEL JET WILL STRENGTHEN AS AN AREA OF LOW PRESSURE ADVANCED TOWARDS LAKE ERIE THIS EVENING. LOOK FOR WINDS AROUND 20KT WITH GUSTS AROUND 25 KT OVERNIGHT. THE SW DIRECTION WILL KEEP THE LARGEST WAVES OFFSHORE OR IN CANADIAN WATERS. COULD STILL SEE SOME 4 FOOTERS IN THE NEAR SHORE. ENERGY WILL SLIDE EAST SUNDAY MORNING AND THOUGH WINDS ARE STILL SW THE SPEEDS WILL DROP OFF NOTABLY. THE NEXT FRONTAL BOUNDARY WILL COME THROUGH MONDAY NIGHT AT WHICH TIME THE WINDS COULD ONCE AGAIN REACH SMALL CRAFT. HIGH PRESSURE WILL BUILD BACK IN AND WINDS/WAVES WILL REMAIN BELOW HEADLINE CRITERIA THE REST OF THE FORECAST PERIODS. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR LEZ148- 149. && $$ SYNOPSIS...KOSARIK NEAR TERM...LOMBARDY SHORT TERM...KUBINA LONG TERM...JAMISON AVIATION...KIELTYKA MARINE...JAMISON
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1233 AM EDT SUN AUG 31 2014 .SYNOPSIS... A WEAK COLD FRONT OVER THE GREAT LAKES WILL BECOME STATIONARY ON SUNDAY JUST NORTH OF LAKE ERIE. AN AREA OF LOW PRESSURE OVER THE GULF COAST STATES WILL MOVE NORTHEAST UP THE APPALACHIANS OVERNIGHT AND SUNDAY. A STRONGER COLD FRONT WILL MOVE FROM THE NORTHERN PLAINS AND CROSS THE AREA ON TUESDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... BAND OF SHOWERS CONTINUE TO MOVE NORTHEAST ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA IN ASSOCIATION WITH UPPER LEVEL POSITIVE VORTICITY ADVECTION. MORE ACTIVE ACTIVITY ACROSS SOUTHERN OHIO SHOULD LIFT NORTHEAST INTO THE REGION OVERNIGHT BUT SHOULD ALSO WEAKEN TO JUST SHOWERS. FURTHER WEST...A LINE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO ADVANCE EAST WITH THE COLD FRONT. LATEST HRRR GUIDANCE SUGGESTS LINE WILL WEAKEN BY THE TIME IT REACHES OUR AREA. THIS SEEMS LOGICAL SINCE THERE IS A LOT OF CIN OVER THE REGION AT THIS TIME TO OVERCOME. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/... A WARM...MUGGY AND UNSETTLED AIR MASS WILL LINGER OVER THE AREA MOST OF THE PERIOD. UNSEASONABLY WARM SURFACE DEW POINTS WILL MAKE IT FEEL MORE LIKE JULY THAN LABOR DAY WEEKEND. MODELS CONTINUE TO HAVE DIFFICULTY PIN POINTING PRECIP CHANCES. IT DOES APPEAR THAT BEST CHANCES FOR PRECIP ON SUNDAY WILL BE ACROSS THE SOUTHEAST HALF OF THE AREA. FURTHER NORTH WEAK HIGH PRESSURE WILL BRIEFLY BUILD OVER LAKE ERIE IN THE WAKE OF THE SURFACE LOW MOVING THROUGH NOW. BY SUNDAY EVENING THE THREAT FOR PRECIP SHOULD BE OVER ALL AREAS. ANOTHER LOW OVER THE PLAINS WILL LIFT A WARM FRONT BACK ACROSS THE AREA ON MONDAY. THE MODELS ARE IN A LITTLE BIT BETTER AGREEMENT WITH THIS SYSTEM. WILL NEED ANOTHER PERIOD OF LIKELY OR HIGHER WORDING FROM LATE MONDAY TILL A COLD FRONT CROSSES THE REGION ON TUESDAY. PRECIP CHANCES WILL DIMINISH BY TUESDAY EVENING. THE FRONTAL PASSAGE WON`T BE STRONG ENOUGH TO BRING A COMPLETE AIR MASS CHANGE BUT SURFACE DEW POINTS SHOULD DIP INTO THE LOWER 60S. SUNDAY WILL BE THE COOLEST DAY OF THE PERIOD WITH THE PRECIP ACROSS THE AREA. THE REMAINDER OF THE PERIOD WILL BE ABOVE NORMAL AND HAVE USED A BLEND OF GUIDANCE. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... UPPER RIDGE BUILDS IN FROM THE SOUTH BEHIND EXITING TROUGH ON WEDNESDAY. WITH INFLUENCE OF THE RIDGE IN WEAK FLOW PATTER MOST CONVECTION WILL BE SUPPRESSED. CAN`T COMPLETELY RULE OUT TSRA BUT FOR NOW WILL KEEP A SMALL POP IN THROUGH FRIDAY. THE MODELS ARE IN FAIRLY STRONG AGREEMENT THAT THE RIDGE WILL LEAD TO H850 TEMPS 18-20C FOR LATE IN THE WEEK. THIS MAKES IT DIFFICULT TO LEAN TOWARDS THE MUCH COOLER CLIMATOLOGY (UPPER 70S) FOR THU-SAT...SO HAVE TRENDED CLOSER TO THE MODEL GUIDANCE MID 80S. THE MOISTURE ADVECTION IS NOT AS FAVORABLE AS IT WAS WITH THE CURRENT WEATHER PATTERN...SO DESPITE HIGH SFC DEW POINTS THE OVERALL PRECIPITABLE WATER VALUES FOR THE AIR COLUMN WILL BE LOWER IN THE 1.5" RANGE. THIS WILL AGAIN SUPPORT A LOWER CHANCE FOR PRECIPITATION. THE TIMING ON THE FRONT WHICH WILL BRING THE WARM WEATHER TO AN END IS LOOKING MORE LIKE LATE SATURDAY WHICH SHOULD BRING BETTER CHANCES OF THUNDERSTORMS. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... LOW PRESSURE SYSTEM OVER NORTHERN MICHIGAN WITH COLD FRONT INTO SOUTHERN PLAINS. SWATH OF SHOWERS WITH A FEW EMBEDDED TSRA NOW INTO SW OHIO WILL WILL MOVE ACROSS THE SOUTHERN AND EASTERN LOCATIONS THIS EVENING. MODELS HINT AT ANOTHER WAVE OF PRECIP OVER THE SOUTHERN AND EASTERN TERMINALS TOMORROW MORNING. FRONT WILL APPROACH NW OHIO TONIGHT THEN BECOME DIFFUSE...SO COULD SEE SOME TSRA NW OHIO LATER THIS EVENING. JUST WENT WITH TSVC IN TAFS. OUTLOOK...NON VFR LIKELY IN SHOWERS AND THUNDERSTORMS THROUGH TUESDAY AT TIMES. && .MARINE... LOW LEVEL JET WILL STRENGTHEN AS AN AREA OF LOW PRESSURE ADVANCED TOWARDS LAKE ERIE THIS EVENING. LOOK FOR WINDS AROUND 20KT WITH GUSTS AROUND 25 KT OVERNIGHT. THE SW DIRECTION WILL KEEP THE LARGEST WAVES OFFSHORE OR IN CANADIAN WATERS. COULD STILL SEE SOME 4 FOOTERS IN THE NEAR SHORE. ENERGY WILL SLIDE EAST SUNDAY MORNING AND THOUGH WINDS ARE STILL SW THE SPEEDS WILL DROP OFF NOTABLY. THE NEXT FRONTAL BOUNDARY WILL COME THROUGH MONDAY NIGHT AT WHICH TIME THE WINDS COULD ONCE AGAIN REACH SMALL CRAFT. HIGH PRESSURE WILL BUILD BACK IN AND WINDS/WAVES WILL REMAIN BELOW HEADLINE CRITERIA THE REST OF THE FORECAST PERIODS. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY FROM 4 AM EARLY THIS MORNING TO 4 PM EDT THIS AFTERNOON FOR LEZ148-149. && $$ SYNOPSIS...KOSARIK NEAR TERM...LOMBARDY SHORT TERM...KUBINA LONG TERM...JAMISON AVIATION...DJB MARINE...JAMISON
AREA FORECAST DISCUSSION
NWS TULSA OK
618 PM CDT MON SEP 1 2014 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. FOR THE 0Z TAFS... SCATTERED SHOWERS AND THUNDERSTORMS WILL LIKELY AFFECT NORTHEAST OKLAHOMA AND NORTHWEST ARKASNAS SITES THIS EVENING. SOME STORMS COULD BE SEVERE WITH LARGE HAIL AND HIGH WINDS. TEMPORARY MVFR CONDITIONS COULD BE EXPERIENCED WITH ANY THUNDERSTORM ACTIVITY. && .PREV DISCUSSION... /ISSUED 329 PM CDT MON SEP 1 2014/ DISCUSSION... A PROGRESSIVE...LOW AMPLITUDE SHORTWAVE TROUGH IS SLIDING EAST ACROSS THE NORTH CENTRAL PART OF THE COUNTRY TODAY. A PAIR OF EMBEDDED VORTICITY MAXIMA EXIST...ONE LIFTING QUICKLY NORTHEAST INTO THE GREAT LAKES...AND ANOTHER MOVING ACROSS WY ATTM. NORTHEAST OK/NORTHWEST AR LIES ON THE SOUTHERN FRINGE OF THE DECENT WESTERLY FLOW IN THE MID LEVELS. AT THE SURFACE...A MORE COMPLEX PATTERN EXISTS DUE TO OVERNIGHT CONVECTION THAT WAS MORE EXTENSIVE THAN FORECAST. THE OUTFLOW BOUNDARY FROM THAT CONVECTION HAS BEEN RETREATING NORTH DURING THE AFTERNOON AND IS APPROACHING THE KANSAS BORDER. MEANWHILE...THE SYNOPTIC COLD FRONT HAS BECOME NEARLY STATIONARY ACROSS CENTRAL AND SW KS. THE HRRR HAS BEEN CONSISTENT ALL DAY IN DVLPNG STORMS BTWN 22-00Z IN THE ZONE BTWN THE TWO BOUNDARIES. DIRECTIONAL/SPEED SHEAR SHOULD BE GREAT ENOUGH TO SUPPORT SUPERCELLS...ESPECIALLY GIVEN AVAILABLE CAPE. LOW LEVEL BACKED WINDS IN BTWN THE TWO BOUNDARIES SUGGESTS...IF A SUPERCELL CAN GET GOING...THAT A LARGE HAIL/TORNADO RISK EXISTS BEFORE CELLS GRADUALLY CONGEAL INTO CLUSTERS AND THEN MOVE E/SE THIS EVENING...WHEN THE MAIN THREAT BECOMES DAMAGING WINDS. MORE DEVELOPMENT IS FORECAST BY THE HRRR LATER TONIGHT NORTH OF THE EFFECTIVE BOUNDARY. THERE WILL BE A SHARP CUTOFF AS YOU GO SOUTH WHERE RAIN FALLS AND WHERE IT DOESN`T...GIVEN STRONG CAP IN PLACE DUE TO EML. I BACKED OFF SOME ON LOWS TONIGHT ACROSS THE NE OK AND NW AR GIVEN POTENTIAL FOR CONVECTIVELY COOLED OUTFLOW...MUCH LIKE LAST NIGHT. RAIN/STORM CHANCES WILL CONTINUE INTO TUESDAY MAINLY ACROSS NE OK/NW AR NEAR AND NORTH OF THE EFFECTIVE BOUNDARY...WHICH WILL BEGIN TO RETREAT AGAIN TOMORROW AND ESPECIALLY TOMORROW NIGHT. THE BEST CHANCES FOR RAIN/STORMS TUESDAY NIGHT WILL BE NORTH AND EAST OF TULSA IN THE WARM ADVECTION REGIME. PRECIP CHANCES COME TO AN END WEDNESDAY AS THE BOUNDARY LIFTS NORTH OF THE REGION AND MID LEVEL HEIGHTS RISE. GUSTY SOUTHWEST WINDS WILL PUSH TEMPS BACK INTO THE UPPER 90S WEDNESDAY AFTERNOON ACROSS NE OK. THE DETERMINISTIC RUNS OF THE GFS/ECMWF TODAY ARE SLOWER WITH THE FRONT TOWARD THE END OF THE WEEK...GFS MORE SO THAN THE ECMWF. NEVERTHELESS...POPS WILL BE CARRIED FRIDAY AND SATURDAY...GRADUALLY TAPERING OFF SUNDAY. TEMPS WILL FALL BACK INTO THE 80S FOR HIGHS AND 60S FOR LOWS. THE RATHER ACTIVE PATTERN ACROSS THE NORTHERN TIER OF STATES CONTINUES INTO NEXT WEEK...AS ANOTHER STRONG SYSTEM MOVES ACROSS THE NORTHERN PART OF THE COUNTRY. AN EVEN STRONGER FRONT COULD BE ON THE WAY IN ABOUT 10 DAYS...A SIGN OF THE CHANGE IN SEASONS. LACY && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...06
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
655 AM EDT SUN AUG 31 2014 .SYNOPSIS... A WARM AND HUMID SOUTHWEST FLOW WILL KEEP THE CHANCES FOR RAIN IN THE FORECAST THROUGH THE LABOR DAY HOLIDAY. A COLD FRONT WILL BRING A BREAK IN THE HUMIDITY FOR MID WEEK. && .NEAR TERM /THROUGH TONIGHT/... THE RADAR BECOMING MORE ACTIVE WITH SCATTERED SHOWERS AND THUNDERSTORMS MOVING THROUGH WRN PA...MAKING SLOW PROGRESS TOWARD MY FCST AREA. THE HRRR SHOWS THE RAIN CURRENTLY FROM KENTUCKY INTO SOUTHERN OHIO CONTINUING TO MARCH NORTHEAST THROUGH MORNING WITH MOST OF MY WESTERN ZONES GETTING WET BY ABOUT 6-7AM...AND MUCH OF THE REST OF MY FCST AREA COVERED WITH SHOWERS AND THUNDERSTORMS BY MID DAY. THIS AFTERNOON WE COULD ALSO SEE A SEVERE THREAT DEVELOP FOR MY SERN ZONES. MODELS ARE COOKING UP A FAIR AMOUNT OF CAPE OVER EASTERN AREAS HINTING THAT THE THE CLOUDS WILL BE LESS EXTENSIVE ALLOWING FOR MORE IN THE WAY OF SOLAR HEATING. FORECAST MID LEVEL LAPSE RATES ARE WEAK BUT SHEAR WILL INCREASE WHICH COULD AID IN ORGANIZING STORM DEVELOPMENT. MODELS ALSO PROG A WEAK LOW LEVEL CONVERGENCE ZONE...PERHAPS THE REMNANTS OF THE OLD WARM FRONT WHERE ENHANCED LOW LEVEL SHEAR...EHI`S PROGGED 1-3(M^2/S^2) COULD HELP A STORM OR TWO TAKE ON SOME SPIN. WITH LOW LCLS EXPECTED IN THE VERY TROPICAL AIRMASS...HAVE TO STAY AWARE OF THE POTENTIAL FOR AN ISOLATED TORNADO. AS IT STANDS RIGHT NOW...THE SEVERE THREAT WILL BE VERY DEPENDENT ON GETTING THE SUN TO COME OUT AND FIRST COOK UP THE CAPES. WITH AN ANOMALOUSLY STRONG LOW LEVEL JET AND PURE TROPICAL AIR...ANOTHER THREAT WILL BE LOCALLY HEAVY RAIN IN SOME OF THE THUNDERSTORMS. IT HAS BEEN DRY SO NO HEADLINES ARE PLANNED...BUT WILL OPT FOR SOME ENHANCED WORDING IN THE FORECAST AND HWO PRODUCT. HIGHS WILL NOT BE TERRIBLY HIGH...IN THE MID 70S TO MID 80S FROM NW TO SE...BUT DEWPOINTS WELL UP IN THE 60S TO LOWER 70S WILL BRING ONE OF THE MORE UNCOMFORTABLY HUMID DAYS WE`VE SEEN THIS SUMMER. IT`S HARD TO PIN DOWN WHAT WILL OCCUR OVERNIGHT WITH REGARD TO CONVECTION. ECMWF/NAM/GFS ALL PAINT DIFFERENT SCENARIOS. THE NAM/SREF REPRESENT THE WETTEST SOLUTIONS WITH SOME SORT OF MESO LOW TRACKING ACROSS SOUTHERN PA. THE GFS/GEFS ARGUE FOR SMALLER CHANCES OF RAIN WITH MOST OF THE AREA SEEING WEAK LOW LEVEL RIDGING DEVELOP IN THE WAKE OF TODAY`S EVENTS. THE ECMWF IS THE DRIEST OF ALL. RIGHT NOW WE HAVE LIKELY POPS OVER THE SOUTH AND CHANCE OVER THE NORTH. UNLESS I SEE SOMETHING COMPELLING...WILL PROBABLY NOT CHANGE IT MUCH GIVEN THE EXPECTATIONS OF LITTLE OR NO REAL FOCUSING MECHANISM. ANOTHER WARM MUGGY NIGHT IS IN STORE AS THE AIRMASS WILL REMAIN VIRTUALLY UNCHANGED. && .SHORT TERM /MONDAY/... AT THIS TIME I AM HOLDING OUT HOPE OF A DRIER LABOR DAY...BUT CANNOT DROP THE MENTION OF RAIN ALTOGETHER. SREF/GEFS BOTH SHOW THE ANOMALOUS PWAT PLUME SLIDING EAST WITH DRYING TAKING PLACE LOCALLY. SHORT RANGE OPERATIONAL GUIDANCE HINTS AT WEAK SHORTWAVE RIDGING AND RISING UPPER HEIGHTS...SO I TRENDED POPS DOWN DURING THE DAY WITH THE THINKING BEING THAT MOST AREAS WILL HAVE A DRY AFTERNOON AND EVENING FOR THE LAST OF THE TRADITIONAL SUMMER`S COOKOUTS. OVERALL IT WILL NOT FEEL SIGNIFICANTLY DRIER HOWEVER AS TEMPERATURES WILL ONCE AGAIN RISE INTO THE 70S AND 80S WITH DEWPOINTS REMAINING TROPICAL IN THE 60S AND LOWER 70S. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... STILL PRETTY GOOD AGREEMENT IN A COLD FRONT SWINGING THROUGH THE STATE LATE TUESDAY. THIS SHOULD PROVIDE THE BEST CHANCE OF RAIN IN THE EXTENDED BEFORE HIGH PRESSURE BUILDS IN FOR MIDWEEK...BRINGING A FEW DAYS OF MILD AND DRY WEATHER. THE NEXT CHANCE FOR RAIN LOOKS LIKE IT WILL NOT BE UNTIL LATER IN THE WEEK WHEN A MORE HUMID FLOW WILL DEVELOP AROUND THE HIGH MOVING OFF THE COAST. AT THIS POINT A COLD FRONT LOOKS LIKELY FOR SATURDAY FOLLOWED BY A COOLER AIRMASS FOR NEXT WEEKEND. THIS UPCOMING WEEK WILL BE ONE OF THE RARE EXTENDED PERIODS OF WARMER THAN NORMAL TEMPERATURES WE HAVE SEEN THIS SUMMER. HIGH TEMPERATURES WILL CLIMB TO ALMOST 90 ACROSS THE SOUTH AND EAST ON TUESDAY AHEAD OF THE FRONTAL PASSAGE. THEN AN UPPER RIDGE WILL BUILD OVER THE EASTERN US FOR THE SECOND HALF OF THE WEEK...KEEPING HIGH TEMPERATURES AT OR SLIGHTLY ABOVE SEASONAL NORMALS FOR EARLY SEPTEMBER. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... MAIN AREAS THAT STILL HAVE CIGS IN THE 1500 RANGE IS IPT...MDT...AND LNS. MOST OF THE LOWER CIGS OUT OF THE UNV...AOO...AND JST. SHOWERS IN THE BFD AREA AT 12Z. RATHER FAST MOVING BOW ECHO WILL MOVE JUST NORTH OF UNV. WILL ADJUST THE 12Z TAFS. ANYWAY...THE MAIN ISSUE NOW IS THE LARGE AREA OF SHOWERS AND THUNDERSTORMS JUST MOVING INTO OUR AREA FROM PIT. BEEN UPDATING FCST AS NEEDED. OUTLOOK... MON...AM FOG POSS...ESP W MTNS. ISOLD PM TSRA IMPACTS POSS. TUE...SCT PM TSRA IMPACTS POSS. WED...PATCHY AM FOG POSS. THU...PATCHY AM FOG POSS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LA CORTE AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
556 AM EDT SUN AUG 31 2014 .SYNOPSIS... A WARM AND HUMID SOUTHWEST FLOW WILL KEEP THE CHANCES FOR RAIN IN THE FORECAST THROUGH THE LABOR DAY HOLIDAY. A COLD FRONT WILL BRING A BREAK IN THE HUMIDITY FOR MID WEEK. && .NEAR TERM /THROUGH TONIGHT/... THE RADAR BECOMING MORE ACTIVE WITH SCATTERED SHOWERS AND THUNDERSTORMS MOVING THROUGH WRN PA...MAKING SLOW PROGRESS TOWARD MY FCST AREA. THE HRRR SHOWS THE RAIN CURRENTLY FROM KENTUCKY INTO SOUTHERN OHIO CONTINUING TO MARCH NORTHEAST THROUGH MORNING WITH MOST OF MY WESTERN ZONES GETTING WET BY ABOUT 6-7AM...AND MUCH OF THE REST OF MY FCST AREA COVERED WITH SHOWERS AND THUNDERSTORMS BY MID DAY. THIS AFTERNOON WE COULD ALSO SEE A SEVERE THREAT DEVELOP FOR MY SERN ZONES. MODELS ARE COOKING UP A FAIR AMOUNT OF CAPE OVER EASTERN AREAS HINTING THAT THE THE CLOUDS WILL BE LESS EXTENSIVE ALLOWING FOR MORE IN THE WAY OF SOLAR HEATING. FORECAST MID LEVEL LAPSE RATES ARE WEAK BUT SHEAR WILL INCREASE WHICH COULD AID IN ORGANIZING STORM DEVELOPMENT. MODELS ALSO PROG A WEAK LOW LEVEL CONVERGENCE ZONE...PERHAPS THE REMNANTS OF THE OLD WARM FRONT WHERE ENHANCED LOW LEVEL SHEAR...EHI`S PROGGED 1-3(M^2/S^2) COULD HELP A STORM OR TWO TAKE ON SOME SPIN. WITH LOW LCLS EXPECTED IN THE VERY TROPICAL AIRMASS...HAVE TO STAY AWARE OF THE POTENTIAL FOR AN ISOLATED TORNADO. AS IT STANDS RIGHT NOW...THE SEVERE THREAT WILL BE VERY DEPENDENT ON GETTING THE SUN TO COME OUT AND FIRST COOK UP THE CAPES. WITH AN ANOMALOUSLY STRONG LOW LEVEL JET AND PURE TROPICAL AIR...ANOTHER THREAT WILL BE LOCALLY HEAVY RAIN IN SOME OF THE THUNDERSTORMS. IT HAS BEEN DRY SO NO HEADLINES ARE PLANNED...BUT WILL OPT FOR SOME ENHANCED WORDING IN THE FORECAST AND HWO PRODUCT. HIGHS WILL NOT BE TERRIBLY HIGH...IN THE MID 70S TO MID 80S FROM NW TO SE...BUT DEWPOINTS WELL UP IN THE 60S TO LOWER 70S WILL BRING ONE OF THE MORE UNCOMFORTABLY HUMID DAYS WE`VE SEEN THIS SUMMER. IT`S HARD TO PIN DOWN WHAT WILL OCCUR OVERNIGHT WITH REGARD TO CONVECTION. ECMWF/NAM/GFS ALL PAINT DIFFERENT SCENARIOS. THE NAM/SREF REPRESENT THE WETTEST SOLUTIONS WITH SOME SORT OF MESO LOW TRACKING ACROSS SOUTHERN PA. THE GFS/GEFS ARGUE FOR SMALLER CHANCES OF RAIN WITH MOST OF THE AREA SEEING WEAK LOW LEVEL RIDGING DEVELOP IN THE WAKE OF TODAY`S EVENTS. THE ECMWF IS THE DRIEST OF ALL. RIGHT NOW WE HAVE LIKELY POPS OVER THE SOUTH AND CHANCE OVER THE NORTH. UNLESS I SEE SOMETHING COMPELLING...WILL PROBABLY NOT CHANGE IT MUCH GIVEN THE EXPECTATIONS OF LITTLE OR NO REAL FOCUSING MECHANISM. ANOTHER WARM MUGGY NIGHT IS IN STORE AS THE AIRMASS WILL REMAIN VIRTUALLY UNCHANGED. && .SHORT TERM /MONDAY/... AT THIS TIME I AM HOLDING OUT HOPE OF A DRIER LABOR DAY...BUT CANNOT DROP THE MENTION OF RAIN ALTOGETHER. SREF/GEFS BOTH SHOW THE ANOMALOUS PWAT PLUME SLIDING EAST WITH DRYING TAKING PLACE LOCALLY. SHORT RANGE OPERATIONAL GUIDANCE HINTS AT WEAK SHORTWAVE RIDGING AND RISING UPPER HEIGHTS...SO I TRENDED POPS DOWN DURING THE DAY WITH THE THINKING BEING THAT MOST AREAS WILL HAVE A DRY AFTERNOON AND EVENING FOR THE LAST OF THE TRADITIONAL SUMMER`S COOKOUTS. OVERALL IT WILL NOT FEEL SIGNIFICANTLY DRIER HOWEVER AS TEMPERATURES WILL ONCE AGAIN RISE INTO THE 70S AND 80S WITH DEWPOINTS REMAINING TROPICAL IN THE 60S AND LOWER 70S. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... STILL PRETTY GOOD AGREEMENT IN A COLD FRONT SWINGING THROUGH THE STATE LATE TUESDAY. THIS SHOULD PROVIDE THE BEST CHANCE OF RAIN IN THE EXTENDED BEFORE HIGH PRESSURE BUILDS IN FOR MIDWEEK...BRINGING A FEW DAYS OF MILD AND DRY WEATHER. THE NEXT CHANCE FOR RAIN LOOKS LIKE IT WILL NOT BE UNTIL LATER IN THE WEEK WHEN A MORE HUMID FLOW WILL DEVELOP AROUND THE HIGH MOVING OFF THE COAST. AT THIS POINT A COLD FRONT LOOKS LIKELY FOR SATURDAY FOLLOWED BY A COOLER AIRMASS FOR NEXT WEEKEND. THIS UPCOMING WEEK WILL BE ONE OF THE RARE EXTENDED PERIODS OF WARMER THAN NORMAL TEMPERATURES WE HAVE SEEN THIS SUMMER. HIGH TEMPERATURES WILL CLIMB TO ALMOST 90 ACROSS THE SOUTH AND EAST ON TUESDAY AHEAD OF THE FRONTAL PASSAGE. THEN AN UPPER RIDGE WILL BUILD OVER THE EASTERN US FOR THE SECOND HALF OF THE WEEK...KEEPING HIGH TEMPERATURES AT OR SLIGHTLY ABOVE SEASONAL NORMALS FOR EARLY SEPTEMBER. && .AVIATION /10Z SUNDAY THROUGH THURSDAY/... CIGS AT MANY SPOTS SUCH AS UNV AND AOO GOING BETWEEN SCT015 AMD BKN015 FOR EXAMPLE...AS BEEN THE CASE SINCE YESTERDAY. ANYWAY...THE MAIN ISSUE NOW IS THE LARGE AREA OF SHOWERS AND THUNDERSTORMS JUST STARTING TO MOVE INTO OUR AREA FROM PIT. BEEN UPDATING FCST AS NEEDED. OUTLOOK... MON...AM FOG POSS...ESP W MTNS. ISOLD PM TSRA IMPACTS POSS. TUE...SCT PM TSRA IMPACTS POSS. WED...PATCHY AM FOG POSS. THU...PATCHY AM FOG POSS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LA CORTE AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
444 AM EDT SUN AUG 31 2014 .SYNOPSIS... A WARM AND HUMID SOUTHWEST FLOW WILL KEEP THE CHANCES FOR RAIN IN THE FORECAST THROUGH THE LABOR DAY HOLIDAY. A COLD FRONT WILL BRING A BREAK IN THE HUMIDITY FOR MID WEEK. && .NEAR TERM /THROUGH TONIGHT/... THE RADAR BECOMING MORE ACTIVE WITH SCATTERED SHOWERS AND THUNDERSTORMS MOVING THROUGH WRN PA...MAKING SLOW PROGRESS TOWARD MY FCST AREA. THE HRRR SHOWS THE RAIN CURRENTLY FROM KENTUCKY INTO SOUTHERN OHIO CONTINUING TO MARCH NORTHEAST THROUGH MORNING WITH MOST OF MY WESTERN ZONES GETTING WET BY ABOUT 6-7AM...AND MUCH OF THE REST OF MY FCST AREA COVERED WITH SHOWERS AND THUNDERSTORMS BY MID DAY. THIS AFTERNOON WE COULD ALSO SEE A SEVERE THREAT DEVELOP FOR MY SERN ZONES. MODELS ARE COOKING UP A FAIR AMOUNT OF CAPE OVER EASTERN AREAS HINTING THAT THE THE CLOUDS WILL BE LESS EXTENSIVE ALLOWING FOR MORE IN THE WAY OF SOLAR HEATING. FORECAST MID LEVEL LAPSE RATES ARE WEAK BUT SHEAR WILL INCREASE WHICH COULD AID IN ORGANIZING STORM DEVELOPMENT. MODELS ALSO PROG A WEAK LOW LEVEL CONVERGENCE ZONE...PERHAPS THE REMNANTS OF THE OLD WARM FRONT WHERE ENHANCED LOW LEVEL SHEAR...EHI`S PROGGED 1-3(M^2/S^2) COULD HELP A STORM OR TWO TAKE ON SOME SPIN. WITH LOW LCLS EXPECTED IN THE VERY TROPICAL AIRMASS...HAVE TO STAY AWARE OF THE POTENTIAL FOR AN ISOLATED TORNADO. AS IT STANDS RIGHT NOW...THE SEVERE THREAT WILL BE VERY DEPENDENT ON GETTING THE SUN TO COME OUT AND FIRST COOK UP THE CAPES. WITH AN ANOMALOUSLY STRONG LOW LEVEL JET AND PURE TROPICAL AIR...ANOTHER THREAT WILL BE LOCALLY HEAVY RAIN IN SOME OF THE THUNDERSTORMS. IT HAS BEEN DRY SO NO HEADLINES ARE PLANNED...BUT WILL OPT FOR SOME ENHANCED WORDING IN THE FORECAST AND HWO PRODUCT. HIGHS WILL NOT BE TERRIBLY HIGH...IN THE MID 70S TO MID 80S FROM NW TO SE...BUT DEWPOINTS WELL UP IN THE 60S TO LOWER 70S WILL BRING ONE OF THE MORE UNCOMFORTABLY HUMID DAYS WE`VE SEEN THIS SUMMER. IT`S HARD TO PIN DOWN WHAT WILL OCCUR OVERNIGHT WITH REGARD TO CONVECTION. ECMWF/NAM/GFS ALL PAINT DIFFERENT SCENARIOS. THE NAM/SREF REPRESENT THE WETTEST SOLUTIONS WITH SOME SORT OF MESO LOW TRACKING ACROSS SOUTHERN PA. THE GFS/GEFS ARGUE FOR SMALLER CHANCES OF RAIN WITH MOST OF THE AREA SEEING WEAK LOW LEVEL RIDGING DEVELOP IN THE WAKE OF TODAY`S EVENTS. THE ECMWF IS THE DRIEST OF ALL. RIGHT NOW WE HAVE LIKELY POPS OVER THE SOUTH AND CHANCE OVER THE NORTH. UNLESS I SEE SOMETHING COMPELLING...WILL PROBABLY NOT CHANGE IT MUCH GIVEN THE EXPECTATIONS OF LITTLE OR NO REAL FOCUSING MECHANISM. ANOTHER WARM MUGGY NIGHT IS IN STORE AS THE AIRMASS WILL REMAIN VIRTUALLY UNCHANGED. && .SHORT TERM /MONDAY/... AT THIS TIME I AM HOLDING OUT HOPE OF A DRIER LABOR DAY...BUT CANNOT DROP THE MENTION OF RAIN ALTOGETHER. SREF/GEFS BOTH SHOW THE ANOMALOUS PWAT PLUME SLIDING EAST WITH DRYING TAKING PLACE LOCALLY. SHORT RANGE OPERATIONAL GUIDANCE HINTS AT WEAK SHORTWAVE RIDGING AND RISING UPPER HEIGHTS...SO I TRENDED POPS DOWN DURING THE DAY WITH THE THINKING BEING THAT MOST AREAS WILL HAVE A DRY AFTERNOON AND EVENING FOR THE LAST OF THE TRADITIONAL SUMMER`S COOKOUTS. OVERALL IT WILL NOT FEEL SIGNIFICANTLY DRIER HOWEVER AS TEMPERATURES WILL ONCE AGAIN RISE INTO THE 70S AND 80S WITH DEWPOINTS REMAINING TROPICAL IN THE 60S AND LOWER 70S. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... STILL PRETTY GOOD AGREEMENT IN A COLD FRONT SWINGING THROUGH THE STATE LATE TUESDAY. THIS SHOULD PROVIDE THE BEST CHANCE OF RAIN IN THE EXTENDED BEFORE HIGH PRESSURE BUILDS IN FOR MIDWEEK...BRINGING A FEW DAYS OF MILD AND DRY WEATHER. THE NEXT CHANCE FOR RAIN LOOKS LIKE IT WILL NOT BE UNTIL LATER IN THE WEEK WHEN A MORE HUMID FLOW WILL DEVELOP AROUND THE HIGH MOVING OFF THE COAST. AT THIS POINT A COLD FRONT LOOKS LIKELY FOR SATURDAY FOLLOWED BY A COOLER AIRMASS FOR NEXT WEEKEND. THIS UPCOMING WEEK WILL BE ONE OF THE RARE EXTENDED PERIODS OF WARMER THAN NORMAL TEMPERATURES WE HAVE SEEN THIS SUMMER. HIGH TEMPERATURES WILL CLIMB TO ALMOST 90 ACROSS THE SOUTH AND EAST ON TUESDAY AHEAD OF THE FRONTAL PASSAGE. THEN AN UPPER RIDGE WILL BUILD OVER THE EASTERN US FOR THE SECOND HALF OF THE WEEK...KEEPING HIGH TEMPERATURES AT OR SLIGHTLY ABOVE SEASONAL NORMALS FOR EARLY SEPTEMBER. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... THERE WERE A FEW STORMS ACROSS THE NW AT MIDNIGHT. MOST OF THESE NE OF OUR AREA...UP IN WESTERN NY. MAIN ISSUE OVERNIGHT WILL BE A WIDE RANGE OF CONDITIONS. LOW CIGS WILL BE IN SOME SPOTS. 06Z TAFS SENT. EARLIER DISCUSSION BELOW. LATE EVENING SATL IMAGERY SHOWS STRATUS COVERING THE EASTERN HALF OF THE STATE...THE RESULT OF MOIST SERLY FLOW OFF THE ATLANTIC OCEAN. FURTHER WEST...WIDESPREAD VFR NOTED ACROSS THE WESTERN HALF OF THE STATE. ALL MDL DATA POINTS TOWARD DETERIORATING FLYING CONDS OVERNIGHT. PLUME OF HIGH MOISTURE IS IN PLACE OVR CENTRAL PA AND AS LOW LVLS COOL...EXPECT LOWERING STRATUS OVR MOST OF CENTRAL PA. THE WORST CONDS IN THE FORM OF IFR CIGS ARE LIKELY TO BE AT KBFD LATE TONIGHT...WHERE SW FLOW ASCENDS THE HIGHER TERRAIN OF NW PA. MOS GUIDANCE INDICATING A DIP TO IFR CIGS ACROSS MUCH OF CENTRAL PA EARLY SUN AM. HOWEVER...BASED ON LATEST SREF OUTPUT AND EXPECTED SOUTHERLY FLOW RATHER THAN SERLY...BELIEVE MVFR CIGS ARE MORE LIKELY FROM KAOO AND KUNV EASTWARD. THE BEST FLYING CONDS ARE LIKELY TO BE AT KJST...WHERE SOUTH WIND DOWNSLOPING THE HIGHER TERRAIN OF THE CENTRAL APPALACHIANS MAY KEEP CONDS VFR THERE OVERNIGHT. A TROUGH OF LOW PRESSURE APPROACHING FROM THE GRT LKS WILL SPREAD A BAND OF SHRA INTO NW PA SUNDAY MORNING. SCT SHRA/TSRA WILL DEVELOP AHEAD OF THIS FEATURE OVR THE REST OF CENTRAL PA BY SUN AFTN. LOCALIZED VSBY REDUCTIONS ARE POSSIBLE IN ANY OF THESE SHOWERS. HOWEVER...THE BIGGEST AVIATION CONCERN SUNDAY WILL BE THE POSSIBLE LOW CIGS IN THE MORNING...ESP KBFD. PREDOMINANTLY VFR CONDS ARE LIKELY BY SUNDAY AFTN. OUTLOOK... MON...AM FOG POSS...ESP W MTNS. ISOLD PM TSRA IMPACTS POSS. TUE...SCT PM TSRA IMPACTS POSS. WED...PATCHY AM FOG POSS. THU...PATCHY AM FOG POSS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LA CORTE AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
150 AM EDT SUN AUG 31 2014 .SYNOPSIS... A BERMUDA HIGH WILL DEVELOP AND LINGER INTO EARLY NEXT WEEK... RESULTING IN TYPICAL SUMMERTIME HEAT AND SCATTERED AFTERNOON THUNDERSTORMS EACH DAY. && .NEAR TERM /THROUGH TODAY/... AS OF 145 AM EDT SUNDAY...BAND OF CONVECTION CONTINUES TO SLOWLY PUSH EAST ACROSS NORTHEAST GA AND SOUTHWEST NC THIS MORNING. LIGHT/MODERATE PRECIPIATION RATES HAVE BEEN OBSERVED WITH A FEW LOCATIONS RECEIVING NEARLY AN INCH PER HOUR. AS THIS CONVECTION CONTINUES TO MOVE EAST INTO THE WESTERN UPSTATE OF SC...EXPECTING A WEAKENING TREND TO PREVAIL WITH DECREASING RAIN RATES LIKELY. THAT SAID...DECIDED TO INCREASE POPS SUBSTANTIALLY FOR THESE AFFECTED ZONES OVER THE NEXT FEW HOURS WITH POPS TRENDING DOWN NEAR DAYBREAK. ALSO MADE QPF ADJUSTMENTS TO ACCOUNT FOR ABOVE MENTIONED RAIN RATES WHICH DID NOT REVEAL ANY FLOODING CONCERNS AS FORWARD PROPAGATION REMAINS SUFFICIENT. OTHERWISE...TWEAKED TEMPERATURES AND DEWPOINTS TO REFLECT LATEST OBSERVATIONAL TRENDS WITH NO OTHER CHANGES MADE. PREVIOUS DISCUSSIONS... EVENING UPDATE...MADE A NOTABLE CHANGE TO THE POP/WX/QPF GRIDS OVERNIGHT. THE LAST FEW RUNS OF THE HRRR HAVE BEEN CONSISTENT AND THE LATEST OP MODELS HAVE CAUGHT ONTO THE IDEA OF A LINE OF -SHRA/TSRA ORGANIZING ACROSS THE SW/RN ZONES ARND 06Z THEN PUSHING NE THRU 12Z BEFORE DISSIPATING. WONT ANTICIPATE STRONG WX WITH THIS LINE AS IT MOVES UNDERNEATH STRONG RIDGING ALOFT AND INSTABILITY WILL BE WEAK THROUGH A DEEP LAYER. OTHERWISE...A FG THREAT ACROSS THE MTNS AND NC FTHILLS WILL BE CURTAILED WITH CONTINUED BKN/OVC CLOUD COVER...YET PATCHY VSBYS IN THE ONE MILE OR LESS RANGE COULD DEVELOP ACROSS THE NC MTN VALLEYS BEFORE DAYBREAK AS CLOUDS THIN FROM THE SW AFT 09Z. MIN TEMPS WERE BUMPED UP A DEGREE OR TWO MOST LOCALE BASED ON LATEST TRENDS AND ANTICIPATED SLOW COOLING RATES. AS OF 215 PM...LATEST CAM`S SHOWING A LITTLE MORE CONVECTIVE RESPONSE THIS AFTERNOON SO HAVE NUDGED THE POPS HIGHER OVER THE WESTERN UPSTATE AND THE MOUNTAINS. IT STILL LOOKS LIKE CONVECTIVE COVERAGE WILL INCREASE AS THE AFTERNOON PROGRESSES OVER NE GA AND THE SW MOUNTAINS...WITH COVERAGE THEN SPREADING NE INTO THE CENTRAL MOUNTAINS/NORTHERN MOUNTAINS DURING THE EVENING HOURS AS A WEAK SHORT WAVE MOVES THROUGH TN. CAN`T RULE OUT SOME SHOWERS/STORMS AFFECTING THE ADJACENT FOOTHILLS/PIEDMONT DURING THE EVENING SO HAVE BUMPED POPS UPWARD THERE PER LATEST CAMS. HAVE DISCOUNTED THE SPURIOUS DEEP CONVECTION AND HEAVY QPF THAT THE NAM DEVELOPS IN THE NC PIEDMONT OVERNIGHT. DO NOT SEE THE TRIGGERING MECHANISM FOR SUCH A RESPONSE AND THERE IS NO SUPPORT FROM ANY OTHER MODEL. IN REGARD TO THE BIG PICTURE...THE UPPER HIGH WILL BE GRADUALLY SUPPRESSED TO THE SE AS A SERIES OF SHORT WAVES MOVE THROUGH THE TN VALLEY INTO THE MID-ATLANTIC STATES. THE FIRST OF THESE SHORT WAVES WILL MOVE BY THIS EVENING AND THEN ANOTHER ON SUNDAY. AS THE FIRST WAVE MOVES BY TO THE WEST TONIGHT...SCT SHOWERS AND STORMS WILL OCCUR MAINLY OVER THE MOUNTAINS...POSSIBLY CONTINUING INTO THE EARLY MORNING HOURS OF SUNDAY. WITH MOIST PROFILES AND WEAK WIND FIELDS... SEVERE STORMS ARE NOT EXPECTED. HOWEVER...SOME LOCALLY HEAVY IS POSSIBLE. ON SUNDAY...SCT SHOWERS AND STORMS ARE EXPECTED TO DEVELOP AGAIN AS ANOTHER SHORT WAVE MOVES BY TO THE WEST COINCIDING WITH MAX HEATING. THE MODELS HAVE BEEN TRENDING AWAY FROM SHOWING MUCH QPF RESPONSE OUTSIDE THE MOUNTAINS ON SUNDAY. HENCE...HAVE DIALED BACK POPS TO THE SLIGHT CHANCE/CHANCE RANGE OVER THE PIEDMONT. THE BEST COVERAGE SHOULD BE ALONG THE SPINE OF THE MOUNTAINS WHERE NUMEROUS STORMS MAY OCCUR. USED OUR CONSALL BLEND TO POPULATE MOST FIELDS. TEMPS WILL CONTINUE ABOVE CLIMO. MAX TEMPS ON SUNDAY WILL BE CLOSE TO TODAY`S NUMBERS...THOUGH PERHAPS A COUPLE DEGREES LESS WARM IN THE MOUNTAINS DUE TO MORE CONVECTIVE COVERAGE. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... AS OF 200 PM SATURDAY...FAIRLY STANDARD LATE SUMMER WEATHER IS EXPECTED THROUGH THE SHORT TERM...AS SUBTROPICAL/BERMUDA HIGH PRESSURE REMAINS AS THE DOMINANT SYNOPTIC SCALE FEATURE ACROSS THE SOUTHEAST. THIS SHOULD GENERALLY SUPPORT WARM AND HUMID CONDITIONS THROUGH THE PERIOD...WITH CHANCES FOR DIURNAL CONVECTION GENERALLY EXPECTED TO BE NEAR TO SLIGHTLY ABOVE CLIMO (30 PERCENT MTNS/20 PERCENT ACROSS THE LOWER TERRAIN) MON AND TUE AFTERNOONS. CONVECTIVE CHANCES MAY INCREASE SLIGHTLY ACROSS OUR WESTERN AREAS BY TUE EVENING...AS DEEP LAYER MOISTURE INCREASES AHEAD OF A WEAK FRONTAL ZONE. TEMPERATURES ARE EXPECTED TO REMAIN ABOUT A CATEGORY ABOVE NORMAL THROUGH THE PERIOD. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 230 PM EDT SATURDAY...THE LATEST GLOBAL MODELS INDICATE THAT H5 HEIGHTS WILL CONTINUE TO RISE OVER THE FORECAST AREA TUE NIGHT INTO FRI AS A BROAD UPPER RIDGING AMPLIFIES ACROSS THE SOUTHEAST AND GULF STATES. BY SAT...WEAK UPPER NWLY FLOW WILL SET UP AS THE CENTER OF UPPER ANTICYCLONE RETROGRADES TOWARD THE WESTERN CONUS. AT THE SURFACE...HIGH PRESSURE WILL WEAKEN AND SLIDE SOUTH OF THE AREA TUE NIGHT AS A WEAK COLD FRONT APPROACHES FROM THE NW. THE FRONT WILL PUSH THRU THE AREA ON WED AND BECOMES STATIONARY JUST TO OUR SOUTH BY THU. A BERMUDA HIGH WILL THEN BUILD BACK IN FROM THE SE BY FRI AND REMAIN IN PLACE THRU DAY 7. AS FOR OUR SENSIBLE WEATHER...HAVE MENTIONED 30/40 POPS WED/THU DUE TO INCREASING MOISTURE AND BUOYANCY ALONG AND AHEAD OF THE FRONT. FRI/SAT...DIURNAL BUOYANCY AND MOISTURE UNDER THE INFLUENCE OF BERMUDA HIGH WILL BE SUPPORTIVE OF SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS ON EACH DAY...MAINTAINING POPS IN THE 30/40 RANGE. TEMPERATURES WILL STAY AROUND 2-5 DEGREES ABOVE NORMAL WED/THU BEFORE COOLING TO NEAR NORMAL BY FRI. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AT KCLT...VFR CONDITIONS WILL PREVAIL INITIALLY AHEAD OF POSSIBLE VISB REDUCTIONS NEAR DAYBREAK. INITIALIZED TAF VFR WITH 07KT SOUTHERLY WINDS UNDER SCT LOW VFR STRATOCU. INTRODUCED 2HR TEMPO AT 11Z TO ACCOUNT FOR DECOUPLING PBL AND POTENTIAL MVFR LEVEL FOG RESTRICTIONS. BY 13Z CONDITIONS WILL IMPROVE UNDER BKN/OVC LOW LEVEL STRATUS LASTING THROUGH MUCH OF THE MORNING BEFORE LOW LEVEL MOISTURE MIXES OUT. BY MIDDAY...SKIES WILL FEATURE SCT MID/HIGH LEVEL CLOUDS WITH INCREASING SOUTHERLY WINDS FOR THE REMAINDER OF THE PERIOD. AS FOR WX...CURRENT RADAR TRENDS AND LATEST CAM GUIDANCE INDICATE BAND OF CONVECTION ACROSS NORTHEAST GA WILL NOT SURVIVE THE TRIP EAST INTO THE NC PIEDMONT...THEREFORE NO WX MENTION FOR THIS FEATURE. HOWEVER...AS THE PROFILE HEATS DURING THE AFTERNOON HOURS ON SUNDAY CANNOT RULE OUT SHRA/TSRA LATE IN THE DAY THEREFORE KEPT PREVIOUS PROB30 FOR SUCH. ELSEWHERE...A MIXTURE OF VFR/MVFR AND POSSIBLE IFR CONDITIONS WILL BE POSSIBLE THROUGH THE EVENING AT ALL SITES. ABOVE MENTIONED BAND OF CONVECTION WILL SPREAD EAST AFFECTING THE SC SITES ALONG WITH KAVL THROUGH THE OVERNIGHT. THEREFORE EACH TAF LOCATION FEATURES PREVAILING VCTS LEADING UP TO ARRIVAL WITH A TEMPO FOR TSRA AND IFR CIGS/VISB DURING PASSAGE. CONDITIONS WILL SLOWLY IMPROVE AFTER DAYBREAK AT ALL SITES AS ABOVE MENTIONED SHRA/TSRA ERODES ALONG WITH INCREASING CLOUD BASES. VFR WILL PREVAIL LATE IN THE PERIOD WITH THE EXCEPTION OF PROB30 MENTION AT KAVL AND KHKY TO ACCOUNT FOR AFTERNOON CONVECTION. WINDS THROUGH THE PERIOD WILL REMAIN SOUTHERLY WITH FLOW INCREASING INTO SUNDAY AFTERNOON. OUTLOOK...GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH EARLY NEXT WEEK WITH THE EXCEPTION FOR RESTRICTIONS IN THE EARLY MORNING DUE TO LOW CLOUDS AND FOG...PRIMARILY IN THE MOUNTAIN VALLEYS. DIURNAL CONVECTION IS EXPECTED EACH AFTERNOON WITH THE MOST COVERAGE OVER THE MOUNTAINS. CONFIDENCE TABLE... 05-11Z 11-17Z 17-23Z 23-05Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP MED 72% MED 66% HIGH 100% HIGH 100% KAVL HIGH 84% HIGH 86% HIGH 100% HIGH 100% KHKY MED 79% HIGH 92% HIGH 100% HIGH 100% KGMU HIGH 81% LOW 58% HIGH 100% HIGH 100% KAND HIGH 81% MED 68% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JOH NEAR TERM...CDG/LG/SBK SHORT TERM...JDL LONG TERM...JOH AVIATION...CDG
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
331 PM CDT SUN AUG 31 2014 .SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT POTENT SHORTWAVE EVIDENT ON WATER VAPOR OVER WYOMING. AHEAD OF THIS WAVE...OMEGA AND UPPER JET MAX HELPING TO MAINTAIN BAND OF RAINFALL THAT HAS TREKKED FROM SOUTH CENTRAL SD TO NORTHEAST SD OVER THE PAST SEVERAL HOURS. HAVE BEEN ADJUSTING POPS FOR THIS BAND OF RAIN AS IT APPEARS IT WILL SURVIVE MOST IF NOT ALL THE WAY ACROSS THE CWA. HRRR PICKING UP ON THIS QUITE NICELY. OVERNIGHT...EXPECTING SCATTERED SHOWERS AND STORMS TO MOVE EAST ACROSS THE STATE BUT WITH MINIMAL SEVERE THREAT DUE TO LACK OF INSTABILITY. ONLY QUESTION IS THE DEGREE OF AREAL COVERAGE OF PRECIP. SOME MODELS GREATER THAN OTHERS...WITH THE HRRR PARTICULARLY DRY AND SORT OF THE OUTLIER. MOST OTHER MODELS HAVE ACTIVITY MOVING ACROSS AT LEAST THE SOUTHERN HALF OF SD TONIGHT. HAVE ADJUSTED POPS ACCORDINGLY AND LINGERED THEM A BIT LONGER THROUGH THE NIGHT AS NSSL WRF STILL SHOWS CONVECTIVE CLUSTERS OVER SOUTHEAST SD AT 09Z TONIGHT. A WEAKER WAVE MOVES ACROSS THE AREA MONDAY...BUT SHOULD STILL PROVIDE FOR A FEW SCATTERED SHOWERS OR STORMS. AREAL COVERAGE DOES NOT APPEAR IT WILL QUITE MATCH UP TO WHATS MOVING INTO WESTERN SD RIGHT NOW...BUT WORTHY OF 20/30 POPS NONETHELESS. AGAIN A LACK OF INSTABILITY TOMORROW SO SEVERE THREAT IS VERY LOW. TUESDAY STILL LOOKS DRY WITH NO NOTABLE SYSTEMS IN THE AREA. 500 MB HEIGHTS RISE SLOWLY THROUGH THE DAY WITH WARM AIR ADVECTION DEVELOPING. HIGHS WILL BUMP UP INTO THE UPPER 70S TO LOW 80S FOR MOST AREAS. .LONG TERM...WEDNESDAY THROUGH SUNDAY THE EARLY PART OF THE PERIOD STARTS OFF SOMEWHAT ACTIVE AS FAIRLY STRONG SYSTEM MOVES ACROSS THE NORTHERN PLAINS. LATEST MODELS ARE IN FAIR AGREEMENT ON AVAILABLE MOISTURE/INSTABILITY BUT DO SUGGEST CAPPING MIGHT FORCE MOST ACTIVITY TO REMAIN NORTH OF THE CWA WEDNESDAY NIGHT INTO THURSDAY AS COLD FRONT MOVES EAST. THUS POPS NO HIGHER THAN CHC NEEDED AT THIS POINT. BEHIND THE FRONT IT LOOKS FAIRLY DRY FROM THURSDAY THROUGH SUNDAY AS HIGH PRESSURE PROVES DOMINANT. TEMPERATURES WILL START OFF ABOVE NORMAL AT THE BEGINNING OF THE PERIOD THEN TREND TOWARD NORMAL OR EVEN BELOW BY THE END OF THE WEEK. && .AVIATION... 18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS WHATEVER LEFTOVER MVFR CIGS ARE HANGING AROUND SHOULD DISSIPATE THIS AFTERNOON. AN AREA OF RAIN/SHOWERS ASSOCIATED WITH AN MCV IS LIKELY TO AFFECT KPIR/KATY/KABR THIS AFTERNOON INTO THE EARLY EVENING HOURS. OVERALL VFR CONDITIONS ARE EXPECTED LATER THIS AFTERNOON THROUGH TONIGHT. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ SHORT TERM...TMT LONG TERM...TDK AVIATION...TDK WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1244 PM CDT SUN AUG 31 2014 .UPDATE... AVIATION DISCUSSION UPDATED BELOW. SOMEWHAT DIFFICULT FORECAST SHAPING UP FOR TODAY WITH A FEW UNCERTAINTIES. FAIRLY POTENT SHORTWAVE TROUGH CROSSING WYOMING AT THIS TIME. SFC COLD FRONT IT MAKING ITS WAY THROUGH THE EASTERN CWA AND IS ALMOST AT THE SD/MN BORDER. AREA OF RAIN MOVING NORTHEAST ACROSS SOUTH CENTRAL SD. MADE A FEW CHANGES TO THE FORECAST FOR TODAY BASED ON CURRENT MODEL AND RADAR TRENDS. FIRST OFF...SEVERE THREAT LOOKS TO BE EAST OF THE CWA TODAY AND LATEST DAY ONE SEVERE OUTLOOK HAS SHIFTED EAST. FRONTAL PASSAGE SPEED LIKELY PUTS BEST SEVERE POTENTIAL FROM MINNESOTA THROUGH IOWA AND INTO NEBRASKA. HAVING SAID THAT THOUGH...STILL EXPECTING ADDITIONAL SHOWER AND STORM DEVELOPMENT ACROSS WESTERN/CENTRAL SD LATER THIS AFTERNOON...THEN SPREADING EAST INTO THE EVENING. MODELS PICKING UP ON THIS...AND HRRR ACTUALLY HAVING A GOOD REPRESENTATION OF CURRENT CONDITIONS AND MAY BE LATCHING ONTO SOMETHING FOR LATER TODAY. BASICALLY...IT WOULD APPEAR MUCH OF THE CWA IS QUIET TODAY...ESPECIALLY THE NORTHEAST. BUT BY THIS AFTERNOON AND EVENING COULD SEE AN INCREASE IN SHOWER AND STORM COVERAGE. ADJUSTED POPS ACCORDINGLY BUT STILL SOME UNCERTAINTY HERE. NEED TO WATCH AREA OF RAIN MOVING TOWARDS PIERRE TO SEE IF IT HOLDS TOGETHER OR EXPANDS. CONCERNING TODAYS TEMPS...ANOTHER GREY AREA AS ABUNDANT MID LEVEL CLOUDS STREAMING INTO THE REGION MAY KEEP TEMPS DOWN A FEW DEGREES. ALSO DEALING WITH A STRATUS DECK OVER THE NORTHERN CWA IN WHICH ITS RESIDENT TIME OVER THE AREA IS QUESTIONABLE. FURTHER ADJUSTMENTS TO POPS/TEMPS LIKELY NEEDED THROUGHOUT THE DAY. && .PREVIOUS DISCUSSION... .SHORT TERM...TODAY THROUGH TUESDAY WARM ADVECTION/LOW LEVEL JET LINE OF STORMS PUSHING RAPIDLY TO THE EAST/NORTHEAST. THE SURFACE LOW IS POSITIONED BACK TOWARDS THE MO RIVER...AND THE UPPER TROF AXIS IS POSITIONED BACK IN WY. WHILE THE SURFACE LOW/TROF IS EXPECTED TO PUSH INTO THE FAR EASTERN CWA...COOLER AIR ALOFT WILL HELP DESTABILIZE THE ATMOSPHERE ACROSS THE REGION. THE FAR EASTERN CWA WILL CONTINUE TO SEE A FAVORABLE SHEAR PROFILE FOR SEVERE WEATHER...AND THE REST OF THE CWA WILL REMAIN CONVECTIVELY UNSTABLE. LOSS TO DAYTIME HEATING WILL REMOVE THE THREAT OF STORMS...HOWEVER CLOUDS AND LIGHT SHOWERS MAY PERSIST AS THE UPPER TROF REMAINS OVERHEAD. A SECONDARY SHORTWAVE MOVES IN MONDAY EVENING...WITH ANOTHER ROUND OF CONVECTION. AS FOR TEMPERATURES...LOOK FOR HIGHS IN THE 70S BOTH TODAY AND MONDAY. TUESDAY WILL SEE WARMER READINGS UNDER A WARM ADVECTION REGIME. .LONG TERM...TUESDAY NIGHT THROUGH SATURDAY THE MODELS AGREE WELL IN THE LONG TERM WITH KEEPING IT MAINLY DRY ALONG WITH A COOL DOWN. THE PERIOD BEGINS WITH AN UPPER LOW PRESSURE TROUGH DROPPING INTO THE PACIFIC NORTHWEST ON TUESDAY NIGHT. THIS THEN TRACKS ALONG THE CANADIAN BORDER INTO THURSDAY. AT THE SURFACE...A LOW PRESSURE AREA AND COOL FRONT SWEEP FROM NORTHWEST TO SOUTHEAST ACROSS OUR REGION FROM TUESDAY NIGHT INTO THURSDAY. THUS...WARMER AIR AND SUNSHINE IN ADVANCE OF THIS WILL BRING ABOVE NORMAL TEMPERATURES TO THE CWA FOR WEDNESDAY WITH HIGHS IN THE 80S TO AROUND 90 DEGREES IN THE SOUTHWEST CWA. AS THE SURFACE LOW PRESSURE AREA/COOL FRONT PUSH ACROSS THE REGION FOR THURSDAY INTO FRIDAY... TEMPERATURES WILL COOL TO MAINLY THE 70S FOR FRIDAY CONTINUING INTO SATURDAY. SURFACE HIGH PRESSURE LOOKS TO BE IN CONTROL OF THE WEATHER FROM THURSDAY THROUGH SATURDAY. HAVE IN A FEW CHANCES OF SHOWERS/STORMS THROUGH THE PERIOD MAINLY EARLY WITH THE SURFACE LOW AND COOL FRONT. && .AVIATION... 18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS WHATEVER LEFTOVER MVFR CIGS ARE HANGING AROUND SHOULD DISSIPATE THIS AFTERNOON. AN AREA OF RAIN/SHOWERS ASSOCIATED WITH AN MCV IS LIKELY TO AFFECT KPIR/KATY/KABR THIS AFTERNOON INTO THE EARLY EVENING HOURS. OVERALL VFR CONDITIONS ARE EXPECTED LATER THIS AFTERNOON THROUGH TONIGHT. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...TMT SHORT TERM...CONNELLY LONG TERM...MOHR AVIATION...TDK WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1039 AM CDT SUN AUG 31 2014 .UPDATE...REST OF TODAY SOMEWHAT DIFFICULT FORECAST SHAPING UP FOR TODAY WITH A FEW UNCERTAINTIES. FAIRLY POTENT SHORTWAVE TROUGH CROSSING WYOMING AT THIS TIME. SFC COLD FRONT IT MAKING ITS WAY THROUGH THE EASTERN CWA AND IS ALMOST AT THE SD/MN BORDER. AREA OF RAIN MOVING NORTHEAST ACROSS SOUTH CENTRAL SD. MADE A FEW CHANGES TO THE FORECAST FOR TODAY BASED ON CURRENT MODEL AND RADAR TRENDS. FIRST OFF...SEVERE THREAT LOOKS TO BE EAST OF THE CWA TODAY AND LATEST DAY ONE SEVERE OUTLOOK HAS SHIFTED EAST. FRONTAL PASSAGE SPEED LIKELY PUTS BEST SEVERE POTENTIAL FROM MINNESOTA THROUGH IOWA AND INTO NEBRASKA. HAVING SAID THAT THOUGH...STILL EXPECTING ADDITIONAL SHOWER AND STORM DEVELOPMENT ACROSS WESTERN/CENTRAL SD LATER THIS AFTERNOON...THEN SPREADING EAST INTO THE EVENING. MODELS PICKING UP ON THIS...AND HRRR ACTUALLY HAVING A GOOD REPRESENTATION OF CURRENT CONDITIONS AND MAY BE LATCHING ONTO SOMETHING FOR LATER TODAY. BASICALLY...IT WOULD APPEAR MUCH OF THE CWA IS QUIET TODAY...ESPECIALLY THE NORTHEAST. BUT BY THIS AFTERNOON AND EVENING COULD SEE AN INCREASE IN SHOWER AND STORM COVERAGE. ADJUSTED POPS ACCORDINGLY BUT STILL SOME UNCERTAINTY HERE. NEED TO WATCH AREA OF RAIN MOVING TOWARDS PIERRE TO SEE IF IT HOLDS TOGETHER OR EXPANDS. CONCERNING TODAYS TEMPS...ANOTHER GREY AREA AS ABUNDANT MID LEVEL CLOUDS STREAMING INTO THE REGION MAY KEEP TEMPS DOWN A FEW DEGREES. ALSO DEALING WITH A STRATUS DECK OVER THE NORTHERN CWA IN WHICH ITS RESIDENT TIME OVER THE AREA IS QUESTIONABLE. FURTHER ADJUSTMENTS TO POPS/TEMPS LIKELY NEEDED THROUGHOUT THE DAY. && .PREVIOUS DISCUSSION... .SHORT TERM...THROUGH TUESDAY WARM ADVECTION/LOW LEVEL JET LINE OF STORMS PUSHING RAPIDLY TO THE EAST/NORTHEAST. THE SURFACE LOW IS POSITIONED BACK TOWARDS THE MO RIVER...AND THE UPPER TROF AXIS IS POSITIONED BACK IN WY. WHILE THE SURFACE LOW/TROF IS EXPECTED TO PUSH INTO THE FAR EASTERN CWA...COOLER AIR ALOFT WILL HELP DESTABILIZE THE ATMOSPHERE ACROSS THE REGION. THE FAR EASTERN CWA WILL CONTINUE TO SEE A FAVORABLE SHEAR PROFILE FOR SEVERE WEATHER...AND THE REST OF THE CWA WILL REMAIN CONVECTIVELY UNSTABLE. LOSS TO DAYTIME HEATING WILL REMOVE THE THREAT OF STORMS...HOWEVER CLOUDS AND LIGHT SHOWERS MAY PERSIST AS THE UPPER TROF REMAINS OVERHEAD. A SECONDARY SHORTWAVE MOVES IN MONDAY EVENING...WITH ANOTHER ROUND OF CONVECTION. AS FOR TEMPERATURES...LOOK FOR HIGHS IN THE 70S BOTH TODAY AND MONDAY. TUESDAY WILL SEE WARMER READINGS UNDER A WARM ADVECTION REGIME. .LONG TERM...TUESDAY NIGHT THROUGH SATURDAY THE MODELS AGREE WELL IN THE LONG TERM WITH KEEPING IT MAINLY DRY ALONG WITH A COOL DOWN. THE PERIOD BEGINS WITH AN UPPER LOW PRESSURE TROUGH DROPPING INTO THE PACIFIC NORTHWEST ON TUESDAY NIGHT. THIS THEN TRACKS ALONG THE CANADIAN BORDER INTO THURSDAY. AT THE SURFACE...A LOW PRESSURE AREA AND COOL FRONT SWEEP FROM NORTHWEST TO SOUTHEAST ACROSS OUR REGION FROM TUESDAY NIGHT INTO THURSDAY. THUS...WARMER AIR AND SUNSHINE IN ADVANCE OF THIS WILL BRING ABOVE NORMAL TEMPERATURES TO THE CWA FOR WEDNESDAY WITH HIGHS IN THE 80S TO AROUND 90 DEGREES IN THE SOUTHWEST CWA. AS THE SURFACE LOW PRESSURE AREA/COOL FRONT PUSH ACROSS THE REGION FOR THURSDAY INTO FRIDAY... TEMPERATURES WILL COOL TO MAINLY THE 70S FOR FRIDAY CONTINUING INTO SATURDAY. SURFACE HIGH PRESSURE LOOKS TO BE IN CONTROL OF THE WEATHER FROM THURSDAY THROUGH SATURDAY. HAVE IN A FEW CHANCES OF SHOWERS/STORMS THROUGH THE PERIOD MAINLY EARLY WITH THE SURFACE LOW AND COOL FRONT. && .AVIATION... 12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS WINDS WILL COME AROUND TO THE SOUTHWEST AND WEST AND INCREASE THIS MORNING BEHIND A SURFACE LOW PRESSURE AREA MOVING ACROSS NORTHEAST SD. OTHERWISE...AN UPPER LEVEL LOW PRESSURE TROUGH OUT WEST WILL BE MOVING INTO THE REGION TODAY. THIS WILL SPREAD IN VFR MID LEVEL CLOUDS ALONG WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FOR LATE THIS MORNING INTO THE EARLY EVENING. INSERTED SOME VICINITY SHOWERS IN FOR ALL LOCATIONS AT THIS TIME. THE CLOUDS AND PRECIPITATION WILL MOVE OFF TO THE EAST THIS EVENING WITH WINDS BECOMING LIGHT. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...TMT SHORT TERM...CONNELLY LONG TERM...MOHR AVIATION...MOHR WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
251 PM EDT SUN AUG 31 2014 .SHORT TERM...(TONIGHT THROUGH TUESDAY)...AIR MASS WAS SLUGGISH TO DE-STABILIZE THIS AFTERNOON DUE TO EXTENSIVE CLOUD COVER. HOWEVER STARTING TO SEE SCATTERED CONVECTION (SOMEWHAT STRONG) DEVELOP OVER NE AL AND SRN PLATEAU...WHERE MESO PAGE SHOWS 30 KTS OF SHEAR. BASED ON THIS NEW ACTIVITY WENT IN LINE WITH LATEST HRRR AND RAP MODELS. THUS...KEPT A SLIVER OF LIKELY POPS FOR LATE AFTERNOON ACROSS SEQUATCHIE VALLEY AND NRN PLATEAU COUNTIES. OTHERWISE...FOR THIS EVENING...CARRIED CHANCE POPS FROM W TO E ACROSS THE FORECAST AREA WITH HIGHER CHANCES WEST. DROPPED BACK TO MOSTLY SLIGHT CHANCE POPS AFTER MIDNIGHT AND ALLOWED FOR PATCHY FOG AREAWIDE LATE. RIDGING IS NOTED BRIEFLY ACROSS THE REGION FOR MONDAY AND MONDAY NIGHT...BEFORE MODELS ADVERTISE ANOTHER APPROACHING SHORTWAVE FOR TUESDAY. LOWERED POPS A BIT MORE FOR MONDAY AND CARRIED JUST MINIMAL POPS IN HIGHER TERRAIN AREAS FOR MONDAY EVENING. CHANCE POPS FOR NOW ON TUESDAY...MORE LIKELY IN THE AFTERNOON. I THINK FOG COULD BE MORE OF AN ISSUE MONDAY NIGHT GIVEN AN APPARENT LACK OF CONVECTIVE DEBRIS CLOUDS. FOR TEMPS...MOS MINS CLOSE AND GENERALLY FOLLOWED. FAVORED THE WARMER MAXES MONDAY AND STAYED A BIT BELOW THE WARMER GFS MAXES ON TUESDAY. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)...A WEAK FRONTAL BOUNDARY IS PROGGED TO DROP SOUTH ACROSS THE VIEWING AREA WEDNESDAY INTO THURSDAY GENERATING A LITTLE BETTER CHANCE FOR SOME SHOWERS AND THUNDERSTORMS ACROSS THE REGION. THE MODELS DON`T SHOW MUCH DRYING AND STABILIZING BEHIND THIS WEAK FEATURE SO KEPT CHANCE POPS FOR CONVECTION GOING AREA WIDE ON FRIDAY AND SATURDAY. ANOTHER LOW AMPLITUDE UPPER TROUGH PASSAGE ACROSS THE NORTHEASTERN QUARTER OF THE COUNTRY HAS BEEN MODELED FOR LATE IN THE WEEKEND SO RAISED POPS IN THE CHANCE CATEGORY FOR SUNDAY AS A SURFACE COOL FRONTAL BOUNDARY ACCOMPANIES THE UPPER FEATURE. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 69 93 71 92 / 30 20 10 30 KNOXVILLE MCGHEE TYSON AIRPORT, TN 69 90 69 90 / 30 10 10 30 OAK RIDGE, TN 68 91 69 90 / 40 10 10 30 TRI CITIES AIRPORT, TN 66 90 63 89 / 30 10 10 30 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ TG
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
950 AM EDT SUN AUG 31 2014 .DISCUSSION...CHALLENGE FOR FORECAST THIS MORNING IS HOW FAR EAST THE STEADY STREAM OF SHOWERS AND TSRA SPREAD...AS THE SHORTWAVE TROUGH TO OUR NORTH TRACKS ACROSS THE GREAT LAKES AND OHIO VALLEY. THE SHORT RANGE MODELS...MAINLY THE HRRR AND RAP...SEEM MORE REASONABLE IN KEEPING THE BEST COVERAGE ACROSS OUR WRN COUNIES. FORECAST GRIDS GENERALLY IN LINE WITH THIS SCENARIO...BUT WILL MONITOR RADAR DEVELOPMENTS FOR THE REST OF THE MORNING. EXTENSIVE CLOUD COVER COULD HINDER MAX TEMPS THIS AFTERNOON...ALTHO MIN TEMPS WERE VERY MILD...SO REACHING 80S TO NEAR 90 DEGREES IS QUITE POSSIBLE. FORECAST GRIDS AND PRODUCTS LOOK GOOD WITH NO UPDATES NEEDED UNLESS THE SHOWERS WORK FURTHER EAST OF I-75 AND I-81...WHERE SCATTERED WORDING AND HIGH CHANCE POPS ARE FORECAST. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 88 70 93 71 / 50 30 20 10 KNOXVILLE MCGHEE TYSON AIRPORT, TN 87 69 91 69 / 50 30 20 10 OAK RIDGE, TN 87 69 91 69 / 60 30 20 10 TRI CITIES AIRPORT, TN 86 66 87 63 / 50 40 20 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ TG
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
111 PM CDT SUN AUG 31 2014 .DISCUSSION... 18Z AVIATION DISCUSSION. && .AVIATION... A BROAD LIGHT RAIN SHIELD WITH EMBEDDED STORMS EXTENDING FROM THE MATAGORDA BAY REGION COUNTIES NORTHEAST ACROSS NORTHERN GALVESTON BAY AND INTO THE PINEY WOODS...MORE DISCRETE CELLS PASSING ACROSS KUTS AND KCLL THIS HOUR. RAIN WILL BE ENDING THROUGH THE DAY...THIS LULL WILL PERSIST THROUGH EARLY MONDAY MORNING WHERE RETURN NEAR- COASTAL/GULF PRECIPITATION RE-DEVELOPS AND MOVES INLAND PAST SUNRISE. IF NOT WITHIN RAINS/STORM...VFR CEILINGS/VSBY. PERIODS OF OVERNIGHT MVFR/IFR DECKS...OR VSBY-REDUCING HZ/FOG...OVER MORE RURAL AREAS DUE TO A WEAK WIND AND WET GROUND. AREAL SHRA/TSRA COVERAGE MAY NOT BE AS WIDESPREAD AS TODAY...BUT THE FORECAST IS FOR RETURN MORE DISCRETE CELLS LATE MONDAY MORNING INTO EARLY AFTERNOON ACTIVITY...OR AS SOUTHERN COUNTY CONVECTION ADVANCES INTO A MID- UPPER 80F WARMED INTERIOR AIR MASS. 31 && .PREV DISCUSSION... /ISSUED 1014 AM CDT SUN AUG 31 2014/ UPDATE... SEE MORNING UPDATE. DISCUSSION... AT 9 AM...A WEAK TROUGH OR PERHAPS AN OUTFLOW EXTENDS FROM ABOUT LEAGUE CITY TOM PALACIOS. MOISTURE IS PLENTIFUL AT 850 MB WITH DEW PTS AT 16-17 C. AT 700 MB...A WEAK TROUGH EXTENDED FROM ABOUT WHARTON TO MCALLEN WITH A WELL DEFINED 700 MB TROUGH AXIS EXTENDING FROM ABOUT ST LOUIS TO TEXARKANA TO AUSTIN. AT 250 MB...A WELL DEFINED TROUGH AXIS EXTENDS FROM SE OK INTO CENTRAL TEXAS. THE LIFT PROVIDED BY THE MID LEVEL TROUGHS AND DEEP MOISTURE WILL SET THE STAGE FOR ADDITIONAL SHRA/TSRA THROUGH THE MORNING. 12Z SOUNDINGS SHOW PW VALUES BETWEEN 2.2 AND 2.3 INCHES...NO CAPPING AND CONVECTIVE TEMPS IN LOWER 80S. RADAR IS SHOWING A SWATH OF RAINFALL MAINLY ALONG AND EAST OF US HWY 59. 1 TO 3 INCHES OF RAIN HAS FALLEN OVER PARTS OF MATAGORDA AND BRAZORIA COUNTIES WITH A BIT MORE ON THE WAY THIS MORNING. MODELS INITIALIZED FAIRLY WELL SO AM EXPECTING THE RAINFALL TO CONTINUE TO MOVE EAST AND NORTH THROUGH THE MORNING WITH RAINFALL BEGINNING TO DIMINISH BY EARLY THIS AFTN. CURRENT FCST LOOKS ON TRACK BUT MAY TWEAK TEMPS DOWN A BIT IN THE RAIN COOLED AIR. 43 && PREV DISCUSSION... /ISSUED 644 AM CDT SUN AUG 31 2014/ DISCUSSION... SEE AVIATION FOR 12Z TAF DISCUSSION. AVIATION... BAND OF SHRA WITH A FEW ISOLATED TSRA EMBEDDED CONTINUES TO LIFT SLOWLY NORTHWARD ALONG THE US 59 CORRIDOR. HI RES MODELS INDICATE THIS ACTIVITY WILL CONTINUE TO SPREAD NORTHWARD THROUGH THE DAY AND FILL IN FURTHER EAST. BEST COVERAGE AND TSRA CHANCES LOOK TO REMAIN ALONG AND WEST OF INTERSTATE 45 WITH COVERAGE DIMINISHING BY LATE AFTERNOON. LOW CLOUDS REDEVELOP AFTER MIDNIGHT WITH MVFR CIGS POSSIBLE BY DAYBREAK ON MONDAY. 38 && PREV DISCUSSION... /ISSUED 439 AM CDT SUN AUG 31 2014/ DISCUSSION... ALTHOUGH THERE WAS PLENTY OF TROPICAL MOISTURE AND LIFT FROM AN UPPER LEVEL TROUGH AXIS...THE MAJORITY OF CONVECTION FORMED IN THE GULF OF MEXICO AND MOVED INTO E TX AND SW LA. LAKE CHARLES ENDED UP WITH 7.87 INCHES OF RAIN FOR YESTERDAY. THERE IS A SIMILAR ENVIRONMENT IN PLACE TODAY WITH TROPICAL MOISTURE STILL OVER MUCH OF SE TX AND UPPER TX COAST. THE TROUGH AXIS IS SLOWLY WEAKENING BUT STILL COULD BE A FOCUS FOR CONVECTIVE ACTIVITY. BOTH 00Z LCH/CRP SOUNDINGS SHOWED 2.2 INCHES OF PRECIP WATER AND GOES SOUNDER DATA ALSO DEPICTS A SWATH OF TROPICAL MOISTURE STRETCHING SW TO NE ACROSS THE TX COAST. BASED ON WATER VAPOR IMAGERY TROUGH AXIS SHOULD BE MOVING OUT OF THE AREA AS UPSTREAM SHORT WAVE TROUGH MOVES ACROSS THE ROCKIES AND INTO THE PLAINS LATER TODAY/TONIGHT. THIS SHOULD ALSO HELP ADVECT TROPICAL MOISTURE OVER THE REGION THIS MORNING AND AFTERNOON. HI RES MODELS WRF- ARW/RAP/HRRR DEVELOP CONVECTION ALONG THE UPPER TX COAST AND MOVE IT INTO THE COASTAL COUNTIES AROUND 12Z THIS MORNING. RADAR ALREADY SHOWING SOME SHOWER ACTIVITY FROM MATAGORDA BAY AND OFFSHORE. THIS SEEMS TO BE MATCHING THE TRENDS IN THE SHORT RANGE HI RES MODELS. THE NAM/GFS/ECMWF ALSO SUPPORT THE IDEA OF A SWATH OF PRECIP EMBEDDED WITHIN MAIN TROPICAL MOISTURE AXIS. DECIDED TO KEEP MENTION OF 60 POPS. AGAIN WITH THIS MUCH MOISTURE STRONGER STORMS WILL BE CAPABLE OF 1-2 INCHES OF RAIN AN HOUR. ACCUMULATED PRECIP TOTALS FROM 06Z HRRR SHOW SWATH OF 2-4 INCHES OF RAIN BY 21Z THIS AFTERNOON SO ISOLATED HIGHER AMOUNTS OF RAIN WILL BE POSSIBLE. MODELS DO INDICATE RAINFALL COMING TO AN END LATE AFTERNOON AND EVENING SO DECREASED RAIN CHANCES FOR THE AFTERNOON. OVERALL MOISTURE TRENDS IN NAM/GFS KEEP NEARLY 2 INCHES OF PRECIP WATER OVER THE TX COAST THROUGH THE MIDDLE OF THE WEEK. A TROPICAL WAVE IN THE NW CARIBBEAN SHOULD BE MOVING ACROSS THE YUCATAN TODAY AND TOMORROW. NHC GIVES THIS WAVE A 50 PERCENT CHANCE OF BECOMING A TROPICAL CYCLONE OVER NEXT 5 DAYS. ITS BEST CHANCE TO DO SO PER LATEST MODEL GUIDANCE WILL NOT BE UNTIL IT EMERGES IN THE GULF. EVEN THEN ONLY THE NAM REALLY DEVELOPS THE SYSTEM INTO A CLOSED CIRCULATION. THE GFS/ECMWF KEEP IT AS AN OPEN WAVE WHICH HAS BEEN WAY MORE CONSISTENT THAN THE NAM. OVERALL IMPACT TO TX WILL BE TO KEEP A FETCH OF DEEP MOISTURE OFF THE GULF IN PLACE. THIS SHOULD ALLOW FOR DAILY RAIN CHANCES FOR THE NEXT WEEK WITH DAY TIME HEATING DRIVING CONVECTIVE TRENDS. COVERAGE IN CONVECTION WILL BE THE REAL ISSUE AS GLOBAL MODELS ESTABLISH A BROAD ELONGATED UPPER LEVEL RIDGE OVER MUCH OF THE SOUTHERN U.S. THE STRENGTH OF THE RIDGE IS ALSO A QUESTION SO DIFFICULT TO GAGE HOW MUCH SUBSIDENCE WILL BE OCCURRING DUE TO THE RIDGE. WITH THESE FACTORS IN MIND THE FORECAST WILL KEEP AT LEAST SOME MENTION OF THUNDERSTORMS EACH DAY. IT LOOKS LIKE THE HIGHER RAIN CHANCES WILL BE TUE/WED AS THIS IS WHEN TROPICAL MOISTURE FROM THE TROPICAL WAVE MAY IMPACT THE AREA. FORECAST WILL GO WITH 30/40 POPS FOR THESE DAYS WITH 20 POPS FOR THE REST OF THE WEEK. TEMPERATURES FOR THE WEEK WILL BE ABOVE NORMAL BUT STILL THE MORE TYPICAL SUMMER TIME TEMPERATURES. MIN TEMPS IN THE MID/UPPER 70S WILL BE EXPECTED WITH MAX TEMPS IN THE LOW/MID 90S. TEMPS WILL BE GREATLY INFLUENCED BY CONVECTION AND RESULTING CLOUD COVER. AS IT STANDS...WITH 100F NOT EXPECTED FOR A HIGH TEMPERATURE AT KCLL OR KIAH TODAY...THE STREAK OF NOT REACHING 100F FOR A HIGH TEMPERATURE CONTINUES INTO SEPTEMBER. HOPEFULLY IT STAYS THAT WAY FOR THE REST OF THE YEAR. 39 && MARINE... SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS MORNING ACROSS THE COASTAL WATERS AS DEEP TROPICAL MOISTURE MOVES BACK INTO THE REGION. EXPECT ONSHORE FLOW TO PERSIST THROUGH MUCH OF THE UPCOMING WEEK. WIND SPEEDS WILL INCREASE LATE MONDAY NIGHT INTO TUESDAY AND CAUTION FLAGS MAY BE NEEDED FOR THE COASTAL WATERS. 38 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 76 95 76 95 76 / 10 20 10 20 10 HOUSTON (IAH) 77 93 77 93 77 / 10 30 20 30 10 GALVESTON (GLS) 81 89 82 89 81 / 10 30 30 40 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...43 AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1014 AM CDT SUN AUG 31 2014 .UPDATE... SEE MORNING UPDATE. && .DISCUSSION... AT 9 AM...A WEAK TROUGH OR PERHAPS AN OUTFLOW EXTENDS FROM ABOUT LEAGUE CITY TOM PALACIOS. MOISTURE IS PLENTIFUL AT 850 MB WITH DEW PTS AT 16-17 C. AT 700 MB...A WEAK TROUGH EXTENDED FROM ABOUT WHARTON TO MCALLEN WITH A WELL DEFINED 700 MB TROUGH AXIS EXTENDING FROM ABOUT ST LOUIS TO TEXARKANA TO AUSTIN. AT 250 MB...A WELL DEFINED TROUGH AXIS EXTENDS FROM SE OK INTO CENTRAL TEXAS. THE LIFT PROVIDED BY THE MID LEVEL TROUGHS AND DEEP MOISTURE WILL SET THE STAGE FOR ADDITIONAL SHRA/TSRA THROUGH THE MORNING. 12Z SOUNDINGS SHOW PW VALUES BETWEEN 2.2 AND 2.3 INCHES...NO CAPPING AND CONVECTIVE TEMPS IN LOWER 80S. RADAR IS SHOWING A SWATH OF RAINFALL MAINLY ALONG AND EAST OF US HWY 59. 1 TO 3 INCHES OF RAIN HAS FALLEN OVER PARTS OF MATAGORDA AND BRAZORIA COUNTIES WITH A BIT MORE ON THE WAY THIS MORNING. MODELS INITIALIZED FAIRLY WELL SO AM EXPECTING THE RAINFALL TO CONTINUE TO MOVE EAST AND NORTH THROUGH THE MORNING WITH RAINFALL BEGINNING TO DIMINISH BY EARLY THIS AFTN. CURRENT FCST LOOKS ON TRACK BUT MAY TWEAK TEMPS DOWN A BIT IN THE RAIN COOLED AIR. 43 && .PREV DISCUSSION... /ISSUED 644 AM CDT SUN AUG 31 2014/ DISCUSSION... SEE AVIATION FOR 12Z TAF DISCUSSION. AVIATION... BAND OF SHRA WITH A FEW ISOLATED TSRA EMBEDDED CONTINUES TO LIFT SLOWLY NORTHWARD ALONG THE US 59 CORRIDOR. HI RES MODELS INDICATE THIS ACTIVITY WILL CONTINUE TO SPREAD NORTHWARD THROUGH THE DAY AND FILL IN FURTHER EAST. BEST COVERAGE AND TSRA CHANCES LOOK TO REMAIN ALONG AND WEST OF INTERSTATE 45 WITH COVERAGE DIMINISHING BY LATE AFTERNOON. LOW CLOUDS REDEVELOP AFTER MIDNIGHT WITH MVFR CIGS POSSIBLE BY DAYBREAK ON MONDAY. 38 PREV DISCUSSION... /ISSUED 439 AM CDT SUN AUG 31 2014/ DISCUSSION... ALTHOUGH THERE WAS PLENTY OF TROPICAL MOISTURE AND LIFT FROM AN UPPER LEVEL TROUGH AXIS...THE MAJORITY OF CONVECTION FORMED IN THE GULF OF MEXICO AND MOVED INTO E TX AND SW LA. LAKE CHARLES ENDED UP WITH 7.87 INCHES OF RAIN FOR YESTERDAY. THERE IS A SIMILAR ENVIRONMENT IN PLACE TODAY WITH TROPICAL MOISTURE STILL OVER MUCH OF SE TX AND UPPER TX COAST. THE TROUGH AXIS IS SLOWLY WEAKENING BUT STILL COULD BE A FOCUS FOR CONVECTIVE ACTIVITY. BOTH 00Z LCH/CRP SOUNDINGS SHOWED 2.2 INCHES OF PRECIP WATER AND GOES SOUNDER DATA ALSO DEPICTS A SWATH OF TROPICAL MOISTURE STRETCHING SW TO NE ACROSS THE TX COAST. BASED ON WATER VAPOR IMAGERY TROUGH AXIS SHOULD BE MOVING OUT OF THE AREA AS UPSTREAM SHORT WAVE TROUGH MOVES ACROSS THE ROCKIES AND INTO THE PLAINS LATER TODAY/TONIGHT. THIS SHOULD ALSO HELP ADVECT TROPICAL MOISTURE OVER THE REGION THIS MORNING AND AFTERNOON. HI RES MODELS WRF- ARW/RAP/HRRR DEVELOP CONVECTION ALONG THE UPPER TX COAST AND MOVE IT INTO THE COASTAL COUNTIES AROUND 12Z THIS MORNING. RADAR ALREADY SHOWING SOME SHOWER ACTIVITY FROM MATAGORDA BAY AND OFFSHORE. THIS SEEMS TO BE MATCHING THE TRENDS IN THE SHORT RANGE HI RES MODELS. THE NAM/GFS/ECMWF ALSO SUPPORT THE IDEA OF A SWATH OF PRECIP EMBEDDED WITHIN MAIN TROPICAL MOISTURE AXIS. DECIDED TO KEEP MENTION OF 60 POPS. AGAIN WITH THIS MUCH MOISTURE STRONGER STORMS WILL BE CAPABLE OF 1-2 INCHES OF RAIN AN HOUR. ACCUMULATED PRECIP TOTALS FROM 06Z HRRR SHOW SWATH OF 2-4 INCHES OF RAIN BY 21Z THIS AFTERNOON SO ISOLATED HIGHER AMOUNTS OF RAIN WILL BE POSSIBLE. MODELS DO INDICATE RAINFALL COMING TO AN END LATE AFTERNOON AND EVENING SO DECREASED RAIN CHANCES FOR THE AFTERNOON. OVERALL MOISTURE TRENDS IN NAM/GFS KEEP NEARLY 2 INCHES OF PRECIP WATER OVER THE TX COAST THROUGH THE MIDDLE OF THE WEEK. A TROPICAL WAVE IN THE NW CARIBBEAN SHOULD BE MOVING ACROSS THE YUCATAN TODAY AND TOMORROW. NHC GIVES THIS WAVE A 50 PERCENT CHANCE OF BECOMING A TROPICAL CYCLONE OVER NEXT 5 DAYS. ITS BEST CHANCE TO DO SO PER LATEST MODEL GUIDANCE WILL NOT BE UNTIL IT EMERGES IN THE GULF. EVEN THEN ONLY THE NAM REALLY DEVELOPS THE SYSTEM INTO A CLOSED CIRCULATION. THE GFS/ECMWF KEEP IT AS AN OPEN WAVE WHICH HAS BEEN WAY MORE CONSISTENT THAN THE NAM. OVERALL IMPACT TO TX WILL BE TO KEEP A FETCH OF DEEP MOISTURE OFF THE GULF IN PLACE. THIS SHOULD ALLOW FOR DAILY RAIN CHANCES FOR THE NEXT WEEK WITH DAY TIME HEATING DRIVING CONVECTIVE TRENDS. COVERAGE IN CONVECTION WILL BE THE REAL ISSUE AS GLOBAL MODELS ESTABLISH A BROAD ELONGATED UPPER LEVEL RIDGE OVER MUCH OF THE SOUTHERN U.S. THE STRENGTH OF THE RIDGE IS ALSO A QUESTION SO DIFFICULT TO GAGE HOW MUCH SUBSIDENCE WILL BE OCCURRING DUE TO THE RIDGE. WITH THESE FACTORS IN MIND THE FORECAST WILL KEEP AT LEAST SOME MENTION OF THUNDERSTORMS EACH DAY. IT LOOKS LIKE THE HIGHER RAIN CHANCES WILL BE TUE/WED AS THIS IS WHEN TROPICAL MOISTURE FROM THE TROPICAL WAVE MAY IMPACT THE AREA. FORECAST WILL GO WITH 30/40 POPS FOR THESE DAYS WITH 20 POPS FOR THE REST OF THE WEEK. TEMPERATURES FOR THE WEEK WILL BE ABOVE NORMAL BUT STILL THE MORE TYPICAL SUMMER TIME TEMPERATURES. MIN TEMPS IN THE MID/UPPER 70S WILL BE EXPECTED WITH MAX TEMPS IN THE LOW/MID 90S. TEMPS WILL BE GREATLY INFLUENCED BY CONVECTION AND RESULTING CLOUD COVER. AS IT STANDS...WITH 100F NOT EXPECTED FOR A HIGH TEMPERATURE AT KCLL OR KIAH TODAY...THE STREAK OF NOT REACHING 100F FOR A HIGH TEMPERATURE CONTINUES INTO SEPTEMBER. HOPEFULLY IT STAYS THAT WAY FOR THE REST OF THE YEAR. 39 MARINE... SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS MORNING ACROSS THE COASTAL WATERS AS DEEP TROPICAL MOISTURE MOVES BACK INTO THE REGION. EXPECT ONSHORE FLOW TO PERSIST THROUGH MUCH OF THE UPCOMING WEEK. WIND SPEEDS WILL INCREASE LATE MONDAY NIGHT INTO TUESDAY AND CAUTION FLAGS MAY BE NEEDED FOR THE COASTAL WATERS. 38 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 94 76 95 76 95 / 20 10 20 10 20 HOUSTON (IAH) 91 77 93 77 93 / 60 10 30 20 30 GALVESTON (GLS) 88 81 89 82 89 / 60 10 30 30 40 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
644 AM CDT SUN AUG 31 2014 .DISCUSSION... SEE AVIATION FOR 12Z TAF DISCUSSION. && .AVIATION... BAND OF SHRA WITH A FEW ISOLATED TSRA EMBEDDED CONTINUES TO LIFT SLOWLY NORTHWARD ALONG THE US 59 CORRIDOR. HI RES MODELS INDICATE THIS ACTIVITY WILL CONTINUE TO SPREAD NORTHWARD THROUGH THE DAY AND FILL IN FURTHER EAST. BEST COVERAGE AND TSRA CHANCES LOOK TO REMAIN ALONG AND WEST OF INTERSTATE 45 WITH COVERAGE DIMINISHING BY LATE AFTERNOON. LOW CLOUDS REDEVELOP AFTER MIDNIGHT WITH MVFR CIGS POSSIBLE BY DAYBREAK ON MONDAY. 38 && .PREV DISCUSSION... /ISSUED 439 AM CDT SUN AUG 31 2014/ DISCUSSION... ALTHOUGH THERE WAS PLENTY OF TROPICAL MOISTURE AND LIFT FROM AN UPPER LEVEL TROUGH AXIS...THE MAJORITY OF CONVECTION FORMED IN THE GULF OF MEXICO AND MOVED INTO E TX AND SW LA. LAKE CHARLES ENDED UP WITH 7.87 INCHES OF RAIN FOR YESTERDAY. THERE IS A SIMILAR ENVIRONMENT IN PLACE TODAY WITH TROPICAL MOISTURE STILL OVER MUCH OF SE TX AND UPPER TX COAST. THE TROUGH AXIS IS SLOWLY WEAKENING BUT STILL COULD BE A FOCUS FOR CONVECTIVE ACTIVITY. BOTH 00Z LCH/CRP SOUNDINGS SHOWED 2.2 INCHES OF PRECIP WATER AND GOES SOUNDER DATA ALSO DEPICTS A SWATH OF TROPICAL MOISTURE STRETCHING SW TO NE ACROSS THE TX COAST. BASED ON WATER VAPOR IMAGERY TROUGH AXIS SHOULD BE MOVING OUT OF THE AREA AS UPSTREAM SHORT WAVE TROUGH MOVES ACROSS THE ROCKIES AND INTO THE PLAINS LATER TODAY/TONIGHT. THIS SHOULD ALSO HELP ADVECT TROPICAL MOISTURE OVER THE REGION THIS MORNING AND AFTERNOON. HI RES MODELS WRF- ARW/RAP/HRRR DEVELOP CONVECTION ALONG THE UPPER TX COAST AND MOVE IT INTO THE COASTAL COUNTIES AROUND 12Z THIS MORNING. RADAR ALREADY SHOWING SOME SHOWER ACTIVITY FROM MATAGORDA BAY AND OFFSHORE. THIS SEEMS TO BE MATCHING THE TRENDS IN THE SHORT RANGE HI RES MODELS. THE NAM/GFS/ECMWF ALSO SUPPORT THE IDEA OF A SWATH OF PRECIP EMBEDDED WITHIN MAIN TROPICAL MOISTURE AXIS. DECIDED TO KEEP MENTION OF 60 POPS. AGAIN WITH THIS MUCH MOISTURE STRONGER STORMS WILL BE CAPABLE OF 1-2 INCHES OF RAIN AN HOUR. ACCUMULATED PRECIP TOTALS FROM 06Z HRRR SHOW SWATH OF 2-4 INCHES OF RAIN BY 21Z THIS AFTERNOON SO ISOLATED HIGHER AMOUNTS OF RAIN WILL BE POSSIBLE. MODELS DO INDICATE RAINFALL COMING TO AN END LATE AFTERNOON AND EVENING SO DECREASED RAIN CHANCES FOR THE AFTERNOON. OVERALL MOISTURE TRENDS IN NAM/GFS KEEP NEARLY 2 INCHES OF PRECIP WATER OVER THE TX COAST THROUGH THE MIDDLE OF THE WEEK. A TROPICAL WAVE IN THE NW CARIBBEAN SHOULD BE MOVING ACROSS THE YUCATAN TODAY AND TOMORROW. NHC GIVES THIS WAVE A 50 PERCENT CHANCE OF BECOMING A TROPICAL CYCLONE OVER NEXT 5 DAYS. ITS BEST CHANCE TO DO SO PER LATEST MODEL GUIDANCE WILL NOT BE UNTIL IT EMERGES IN THE GULF. EVEN THEN ONLY THE NAM REALLY DEVELOPS THE SYSTEM INTO A CLOSED CIRCULATION. THE GFS/ECMWF KEEP IT AS AN OPEN WAVE WHICH HAS BEEN WAY MORE CONSISTENT THAN THE NAM. OVERALL IMPACT TO TX WILL BE TO KEEP A FETCH OF DEEP MOISTURE OFF THE GULF IN PLACE. THIS SHOULD ALLOW FOR DAILY RAIN CHANCES FOR THE NEXT WEEK WITH DAY TIME HEATING DRIVING CONVECTIVE TRENDS. COVERAGE IN CONVECTION WILL BE THE REAL ISSUE AS GLOBAL MODELS ESTABLISH A BROAD ELONGATED UPPER LEVEL RIDGE OVER MUCH OF THE SOUTHERN U.S. THE STRENGTH OF THE RIDGE IS ALSO A QUESTION SO DIFFICULT TO GAGE HOW MUCH SUBSIDENCE WILL BE OCCURRING DUE TO THE RIDGE. WITH THESE FACTORS IN MIND THE FORECAST WILL KEEP AT LEAST SOME MENTION OF THUNDERSTORMS EACH DAY. IT LOOKS LIKE THE HIGHER RAIN CHANCES WILL BE TUE/WED AS THIS IS WHEN TROPICAL MOISTURE FROM THE TROPICAL WAVE MAY IMPACT THE AREA. FORECAST WILL GO WITH 30/40 POPS FOR THESE DAYS WITH 20 POPS FOR THE REST OF THE WEEK. TEMPERATURES FOR THE WEEK WILL BE ABOVE NORMAL BUT STILL THE MORE TYPICAL SUMMER TIME TEMPERATURES. MIN TEMPS IN THE MID/UPPER 70S WILL BE EXPECTED WITH MAX TEMPS IN THE LOW/MID 90S. TEMPS WILL BE GREATLY INFLUENCED BY CONVECTION AND RESULTING CLOUD COVER. AS IT STANDS...WITH 100F NOT EXPECTED FOR A HIGH TEMPERATURE AT KCLL OR KIAH TODAY...THE STREAK OF NOT REACHING 100F FOR A HIGH TEMPERATURE CONTINUES INTO SEPTEMBER. HOPEFULLY IT STAYS THAT WAY FOR THE REST OF THE YEAR. 39 MARINE... SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS MORNING ACROSS THE COASTAL WATERS AS DEEP TROPICAL MOISTURE MOVES BACK INTO THE REGION. EXPECT ONSHORE FLOW TO PERSIST THROUGH MUCH OF THE UPCOMING WEEK. WIND SPEEDS WILL INCREASE LATE MONDAY NIGHT INTO TUESDAY AND CAUTION FLAGS MAY BE NEEDED FOR THE COASTAL WATERS. 38 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 94 76 95 76 95 / 20 10 20 10 20 HOUSTON (IAH) 91 77 93 77 93 / 40 10 30 20 30 GALVESTON (GLS) 88 81 89 82 89 / 60 10 30 30 40 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...39 AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
439 AM CDT SUN AUG 31 2014 .DISCUSSION... ALTHOUGH THERE WAS PLENTY OF TROPICAL MOISTURE AND LIFT FROM AN UPPER LEVEL TROUGH AXIS...THE MAJORITY OF CONVECTION FORMED IN THE GULF OF MEXICO AND MOVED INTO E TX AND SW LA. LAKE CHARLES ENDED UP WITH 7.87 INCHES OF RAIN FOR YESTERDAY. THERE IS A SIMILAR ENVIRONMENT IN PLACE TODAY WITH TROPICAL MOISTURE STILL OVER MUCH OF SE TX AND UPPER TX COAST. THE TROUGH AXIS IS SLOWLY WEAKENING BUT STILL COULD BE A FOCUS FOR CONVECTIVE ACTIVITY. BOTH 00Z LCH/CRP SOUNDINGS SHOWED 2.2 INCHES OF PRECIP WATER AND GOES SOUNDER DATA ALSO DEPICTS A SWATH OF TROPICAL MOISTURE STRETCHING SW TO NE ACROSS THE TX COAST. BASED ON WATER VAPOR IMAGERY TROUGH AXIS SHOULD BE MOVING OUT OF THE AREA AS UPSTREAM SHORT WAVE TROUGH MOVES ACROSS THE ROCKIES AND INTO THE PLAINS LATER TODAY/TONIGHT. THIS SHOULD ALSO HELP ADVECT TROPICAL MOISTURE OVER THE REGION THIS MORNING AND AFTERNOON. HI RES MODELS WRF- ARW/RAP/HRRR DEVELOP CONVECTION ALONG THE UPPER TX COAST AND MOVE IT INTO THE COASTAL COUNTIES AROUND 12Z THIS MORNING. RADAR ALREADY SHOWING SOME SHOWER ACTIVITY FROM MATAGORDA BAY AND OFFSHORE. THIS SEEMS TO BE MATCHING THE TRENDS IN THE SHORT RANGE HI RES MODELS. THE NAM/GFS/ECMWF ALSO SUPPORT THE IDEA OF A SWATH OF PRECIP EMBEDDED WITHIN MAIN TROPICAL MOISTURE AXIS. DECIDED TO KEEP MENTION OF 60 POPS. AGAIN WITH THIS MUCH MOISTURE STRONGER STORMS WILL BE CAPABLE OF 1-2 INCHES OF RAIN AN HOUR. ACCUMULATED PRECIP TOTALS FROM 06Z HRRR SHOW SWATH OF 2-4 INCHES OF RAIN BY 21Z THIS AFTERNOON SO ISOLATED HIGHER AMOUNTS OF RAIN WILL BE POSSIBLE. MODELS DO INDICATE RAINFALL COMING TO AN END LATE AFTERNOON AND EVENING SO DECREASED RAIN CHANCES FOR THE AFTERNOON. OVERALL MOISTURE TRENDS IN NAM/GFS KEEP NEARLY 2 INCHES OF PRECIP WATER OVER THE TX COAST THROUGH THE MIDDLE OF THE WEEK. A TROPICAL WAVE IN THE NW CARIBBEAN SHOULD BE MOVING ACROSS THE YUCATAN TODAY AND TOMORROW. NHC GIVES THIS WAVE A 50 PERCENT CHANCE OF BECOMING A TROPICAL CYCLONE OVER NEXT 5 DAYS. ITS BEST CHANCE TO DO SO PER LATEST MODEL GUIDANCE WILL NOT BE UNTIL IT EMERGES IN THE GULF. EVEN THEN ONLY THE NAM REALLY DEVELOPS THE SYSTEM INTO A CLOSED CIRCULATION. THE GFS/ECMWF KEEP IT AS AN OPEN WAVE WHICH HAS BEEN WAY MORE CONSISTENT THAN THE NAM. OVERALL IMPACT TO TX WILL BE TO KEEP A FETCH OF DEEP MOISTURE OFF THE GULF IN PLACE. THIS SHOULD ALLOW FOR DAILY RAIN CHANCES FOR THE NEXT WEEK WITH DAY TIME HEATING DRIVING CONVECTIVE TRENDS. COVERAGE IN CONVECTION WILL BE THE REAL ISSUE AS GLOBAL MODELS ESTABLISH A BROAD ELONGATED UPPER LEVEL RIDGE OVER MUCH OF THE SOUTHERN U.S. THE STRENGTH OF THE RIDGE IS ALSO A QUESTION SO DIFFICULT TO GAGE HOW MUCH SUBSIDENCE WILL BE OCCURRING DUE TO THE RIDGE. WITH THESE FACTORS IN MIND THE FORECAST WILL KEEP AT LEAST SOME MENTION OF THUNDERSTORMS EACH DAY. IT LOOKS LIKE THE HIGHER RAIN CHANCES WILL BE TUE/WED AS THIS IS WHEN TROPICAL MOISTURE FROM THE TROPICAL WAVE MAY IMPACT THE AREA. FORECAST WILL GO WITH 30/40 POPS FOR THESE DAYS WITH 20 POPS FOR THE REST OF THE WEEK. TEMPERATURES FOR THE WEEK WILL BE ABOVE NORMAL BUT STILL THE MORE TYPICAL SUMMER TIME TEMPERATURES. MIN TEMPS IN THE MID/UPPER 70S WILL BE EXPECTED WITH MAX TEMPS IN THE LOW/MID 90S. TEMPS WILL BE GREATLY INFLUENCED BY CONVECTION AND RESULTING CLOUD COVER. AS IT STANDS...WITH 100F NOT EXPECTED FOR A HIGH TEMPERATURE AT KCLL OR KIAH TODAY...THE STREAK OF NOT REACHING 100F FOR A HIGH TEMPERATURE CONTINUES INTO SEPTEMBER. HOPEFULLY IT STAYS THAT WAY FOR THE REST OF THE YEAR. 39 && .MARINE... SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS MORNING ACROSS THE COASTAL WATERS AS DEEP TROPICAL MOISTURE MOVES BACK INTO THE REGION. EXPECT ONSHORE FLOW TO PERSIST THROUGH MUCH OF THE UPCOMING WEEK. WIND SPEEDS WILL INCREASE LATE MONDAY NIGHT INTO TUESDAY AND CAUTION FLAGS MAY BE NEEDED FOR THE COASTAL WATERS. 38 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 94 76 95 76 95 / 20 10 20 10 20 HOUSTON (IAH) 91 77 93 77 93 / 40 10 30 20 30 GALVESTON (GLS) 88 81 89 82 89 / 60 10 30 30 40 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...39 AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
937 PM EDT MON SEP 1 2014 .SYNOPSIS... WEAK HIGH PRESSURE WILL REMAIN OVER THE REGION TONIGHT INTO MUCH OF TUESDAY. A WEAK COLD FRONT TRACKS SOUTHEAST INTO OUR AREA BY TUESDAY EVENING...BEFORE STALLING ACROSS THE CAROLINAS AND WASHING OUT ON WEDNESDAY. HIGH PRESSURE SETS BACK UP OVER THE EAST BY FRIDAY WITH YET ANOTHER COLD FRONT MOVING TOWARD US THIS WEEKEND. && .NEAR TERM /THROUGH TUESDAY/... AS OF 850 PM EDT MONDAY... OTHER FOR ISOLATED SHRA/TSRA PASSING ACROSS THE FAR NORTH...CONVECTION REMAINS LIMITED THIS EVENING AS SOUNDINGS SHOW WEAK CAPPING ALOFT WITHIN A DEEP WESTERLY FLOW REGIME. THIS ALONG WITH LACK OF DEEP INSTABILITY SHOULD KEEP THINGS MAINLY QUIET OVERNIGHT WITH JUST SOME PATCHY FOG IN THE VALLEYS AND PERHAPS OUT EAST. HOWEVER WITH THE LATEST HRRR TRACKING THE CURRENT ISOLATED COVERAGE OVER GREENBRIER EAST TOWARD THE SOUTHERN SHENANDOAH VALLEY...WILL LEAVE IN SOME LOW POPS ACROSS THE EXTREME NORTH SINCE HEADING INTO SOME DECENT LEFTOVER CAPE DESPITE LOSS OF HEATING. WILL ALSO CONTINUE SOME LOW CHANCES FAR NW LATE FOR ACTIVITY COMING IN AHEAD OF THE UPSTREAM FRONT AROUND DAYBREAK. OTRW FEW CHANGES OTHER THAN TO INCLUDE A BIT OF FOG AND BUMP UP TEMPS IN SPOTS GIVEN SUCH A MUGGY OVERNIGHT. ANOTHER SHORTWAVE AHEAD OF A FRONT SHIFTING SE INTO THE OHIO VALLEY PASSES ACROSS TUESDAY MORNING. FOR NOW IT LOOKS LIKE THE WESTERN CWA WILL SEE A CHANCE OF SHOWERS/ISOLATED TSRA DURING THE MORNING BUT AGAIN EAST OF THE BLUE RIDGE LOOKS FEEBLE. THERE IS GOOD SUBSIDENCE BEHIND THIS FEATURE BY 18Z TUESDAY BUT ANOTHER WAVE AND THE FRONT ITSELF WILL EDGE CLOSER TOWARD TUE EVENING...WHICH WILL BRING A BETTER THREAT OF SHOWERS AND STORMS TO THE MOUNTAINS WITH ISOLATED TO WIDELY SCATTERED COVERAGE OVER THE FOOTHILLS AND PIEDMONT. TUESDAY WILL BE HOT...WITH ENOUGH SUN TO SEND TEMPS INTO THE LOWER TO MID 90S EAST...AND LOWER TO MID 80S WEST. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... AS OF 224 PM EDT MONDAY... A WEAK COLD FRONT SLIDES ACROSS THE REGION TUESDAY NIGHT...PUSHING PRECIPITATION TO THE EAST COAST. HIGH PRESSURE BUILDS IN FROM THE WEST THROUGH WEDNESDAY. THE ASSOCIATED DEW POINT FRONT AND DRIER AIR IS LAGGING WAY BEHIND AND DOES NOT ENTER THE FORECAST AREA UNTIL LATE WEDNESDAY MORNING. THIS DEW POINT FRONT MAY MAKE IT AS FAR AS THE VA/NC BORDER WEDNESDAY AFTERNOON...THEN BEGINS TO RETREAT TO THE NORTH WEDNESDAY NIGHT AND THURSDAY. SURFACE HIGH PRESSURE WILL KEEP MOST OF THE AREA DRY BUT COULD SEE ISOLATED DIURNAL SHOWERS SOUTH OF THE DEW POINT FRONT WEDNESDAY AFTERNOON/EVENING. AS THIS SURFACE RIDGE DRIFTS OFF THE MID ATLANTIC COAST THURSDAY...SOUTHEAST FLOW AND ATLANTIC MOISTURE WILL INCREASE THE CHANCE FOR SHOWERS FOR AREAS ALONG AND EAST OF THE BLUE RIDGE...ESPECIALLY THE NORTH CAROLINA HIGH COUNTY THURSDAY AFTERNOON. EVEN THOUGH FLOW IS WEAK ALOFT...WARM SOUTHWEST FLOW WILL OVERRUN THIS RIDGE/INSITU WEDGE TO PRODUCE A LOW STRATUS DECK AND A CHANCE FOR LIGHT RAIN/DRIZZLE FOR AREAS EAST OF THE BLUE RIDGE OVERNIGHT THURSDAY. TEMPERATURES WILL RANGE FROM THE UPPER 70S TO LOWER 80S ACROSS THE MOUNTAINS AND UPPER 80S TO LOWER 90S EAST WEDNESDAY AFTERNOON. EASTERLY FLOW THURSDAY WILL PRODUCE UNIFORM TEMPERATURES IN THE 80S. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 248 PM EDT MONDAY... HIGH PRESSURE EXITS THE MID ATLANTIC COAST ON FRIDAY AND WILL BE REPLACED BY A LEE TROUGH. WITH AN UPPER LEVEL RIDGE ACROSS THE GULF STATE TO THE SOUTHEAST COAST...NEARLY ZONAL FLOW MAY BRING A SHORT WAVE OVER THE REGION FRIDAY. THIS SHORT WAVE WILL HELP SPARK CONVECTION THROUGH THE AFTERNOON AND EVENING HOURS. IF THIS SHORT WAVE DOES NOT MATERIALIZE...DIURNAL CONVECTION IS STILL POSSIBLE WITH ABUNDANT MOISTURE...AFTERNOON HEATING AND A LEE TROUGH. FOR THE WEEKEND...A COLD FRONT IS EXPECTED TO PASS OVER THE REGION SATURDAY (GFS) OR SUNDAY (ECM). WITH A STUBBORN UPPER LEVEL RIDGE TO THE SOUTH...FAVORING THE SLOWER ECM RUN. PREFRONTAL OR DIURNAL CONVECTION IS POSSIBLE SATURDAY BUT WILL KEEP THE HIGHEST POPS WITH THE FRONTAL PASSAGE SUNDAY. NOT QUITE SURE IF THE FRONT WILL COMPLETE CLEAR THE FORECAST AREA AS THE UPPER LEVEL RIDGE CONTINUES TO HANG ACROSS THE SOUTHERN STATES. TEMPERATURES WILL REMAIN WARMER THAN NORMAL UNTIL THE FRONT CLEARS THE AREA. ONCE THE FRONT PASSES...TEMPERATURES WILL RUN COOLER THAN NORMAL WITH HIGHS IN THE 70S. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... AS OF 640 PM EDT MONDAY... OVERALL VFR SHOULD PREVAIL OVERNIGHT UNDER DIMINISHING WINDS AND MOSTLY CLEAR SKIES THIS EVENING. A FEW SHOWERS MAY MAKE A RUN AT KLWB OVER THE NEXT COUPLE OF HOURS BUT LIKELY TO DISSIPATE CROSSING THE RIDGES SO LEAVING OUT MENTION WITH JUST A FEW MORE CLOUDS AROUND. WELL MIXED LOW LEVELS FROM THIS AFTERNOON LIKELY TO INHIBIT MUCH FOG DEVELOPMENT EXCEPT FOR SOME BRIEF MVFR AT KLYH/KDAN THAT SHOULD STAY EAST OF ANY UPSTREAM MID DECK THAT MAY ARRIVE OVER THE WEST TOWARD DAWN. CANT TOTALLY RULE OUT SOME BRIEF VALLEY FOG AT KLWB/KBCB JUST AFTER MIDNIGHT BEFORE ANY ADDED CLOUDS PUSH EAST. THUS WENT WITH A BRIEF MVFR TEMPO GROUP AT KLWB/KBCB FOR FOG ALTHOUGH FORECAST FOG STABILITY VALUES SHOW ONLY SPOTTY COVERAGE AT BEST. UPPER TROUGH AND ITS ASSOCIATED COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY WITH MOSTLY ISOLATED MOUNTAIN SHOWERS/STORMS EXPECTED DURING THE DAY AHEAD OF THE BOUNDARY. HOWEVER MAY SEE A MORE ORGANIZED BAND DROP IN FROM THE NW WITH THE LEADING PRE- FRONTAL CONVERGENCE...SO INCLUDING A VCTS MENTION ACROSS THE SOUTHEAST WEST VA SITES AROUND MID AFTERNOON AND LATE AT KBCB. OTRW EXPECTING MOSTLY VFR AFTER EARLY MID DECK ERODES AND SCATTERED-BROKEN CU FIELDS BETWEEN 4-6K FT TAKE SHAPE WITH HEATING. EXTENDED AVIATION DISCUSSION... FRONT SETTLES CLOSER TUESDAY NIGHT INTO WEDNESDAY...WHEN BETTER COVERAGE OF SHRA/TSRA IS EXPECTED. HOWEVER LOW CONFIDENCE ON THE TIMING AND SOUTHWARD POSITION OF THE BOUNDARY ON WEDNESDAY AT THIS POINT PENDING PRE-FRONTAL COVERAGE FROM TUESDAY NIGHT. FOR NOW APPEARS MAINLY VFR OUTSIDE OF EARLY MORNING FOG WEDNESDAY...THEN PERIODS OF MVFR WEDNESDAY AFTERNOON ESPCLY SOUTHERN SECTIONS...AND MAINLY ACROSS THE SOUTH/SOUTHWEST THURSDAY AFTERNOON FOR MORE ISOLATED NATURE COVERAGE. FRONT WASHES OUT TO THE SOUTH OF THE AREA FRIDAY WITH MORE WIDELY SCATTERED DIURNAL NATURE SHOWERS AND STORMS...THEN PERHAPS BECOMING MORE WIDESPREAD SATURDAY WITH PERIODIC MVFR IN MORE ORGANIZED COVERAGE AHEAD OF ANOTHER COLD FRONT ARRIVING FROM THE NORTHWEST LATE. OTRW WILL SEE A DAILY TREND OF EARLY MVFR/IFR IN FOG...FOLLOWED BY BRIEF VFR...THEN INCREASING AFTERNOON/EVENING CONVECTION WHEN MVFR TO LOCAL IFR WILL BE POSSIBLE. && .EQUIPMENT... AS OF 730 AM EDT FRIDAY ... THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...WILL BE OUT OF SERVICE UNTIL FURTHER NOTICE. A PART HAS BEEN BACK-ORDERED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/WP NEAR TERM...JH/WP SHORT TERM...RCS LONG TERM...RCS AVIATION...JH/RAB/WP EQUIPMENT...RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
744 AM EDT SUN AUG 31 2014 .SYNOPSIS... THE REGION WILL STAY BETWEEN A LARGE HIGH PRESSURE SYSTEM OVER THE SOUTHEAST UNITED STATES AND WESTERN ATLANTIC AND A COMPLEX LOW PRESSURE SYSTEM CROSSING THE GREAT LAKES. A COLD FRONT FINALLY ARRIVES FROM THE NORTH BY THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM EDT SUNDAY... ELONGATED BAROCLINIC ZONE IS SUPPORTED BY AN UPPER JET AND AXIS OF VORTICITY THAT EXTENDS FROM THE LOWER MISSISSIPPI VALLEY TO NEW ENGLAND. UPPER RIDGE REMAINS PARKED OVER THE NORTH CAROLINA COAST. BAND OF DEEPER MOISTURE SHOWN ON WATER VAPOR AND TOTAL PRECIPITABLE WATER IMAGES WILL MAKE ONLY SLOW PROGRESS EAST INTO THE COUNTY WARNING AREA BY MONDAY MORNING. MODELS BRING CLUSTER OF SHOWERS AND THUNDERSTORMS OVER KENTUCKY AND TENNESSEE ACROSS MUCH OF THE FORECAST AREA THIS MORNING. NOT SURE HOW FAR EAST THIS PRECIPITATION WILL GET. 06Z HRRR HAD REASONABLE TIMING MOVING THE EASTERN EDGE INTO THE FORECAST AREA THROUGH 8AM SO WILL BE FOLLOWING THAT ALONG WITH RADAR TRENDS. LARGER BAND OF SHOWERS WILL PIVOT ENOUGH TO REACH SOUTHEAST WEST VIRGINIA TONIGHT...SIMILAR TO ORIENTATION OF WPC QPF FORECAST AND THE 00Z GFS...SLIGHTLY FARTHER SOUTH THAN THE 00Z NAM. 4KM NAM AND HRRR DEVELOP THUNDERSTORMS ALONG THE BLUE RIDGE THIS AFTERNOON...CLOSE TO THE EDGE OF THE THICKER CLOUD COVER. EXPECT THE COVERAGE OF THUNDERSTORMS IN THE EAST TO DIMINISH AFTER SUNSET. CLOUDS WILL LIMIT HEATING AND INSTABILITY TODAY. STAYED CLOSER TO BIAS CORRECTED MAV GUIDANCE FOR MAXIMUM TEMPERATURES. HUMID AIR MASS AND VERY MILD DEW POINTS WILL RESULT IN LITTLE COOLING TONIGHT. USED WARMER MET GUIDANCE FOR OVERNIGHT LOWS. && .SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM EDT SUNDAY... PROGRESSIVE NORTHERN STREAM FLOW WILL PRODUCE TROUGHING ACROSS THE NORTHEAST BY MONDAY MORNING. SEVERAL SHORTWAVES TRAVERSE ACROSS THE MID ATLANTIC REGION. THESE UPPER DISTURBANCES WILL SHAPE THE TIMING OF CONVECTION. AN UPPER DISTURBANCE WILL SHIFT ACROSS THE GREAT LAKES FROM THE OHIO RIVER VALLEY MONDAY MORNING...ENHANCING THE CHANCES OF SHOWERS IN THE WEST-NORTHWEST. THE SUBTROPICAL BERMUDA HIGH PRESSURE WILL REMAIN IN PLACE. A VERY MOIST SOUTHWEST FLOW WILL CONTINUE LABOR DAY. HIGH TEMPERATURES MONDAY WILL RANGE FROM THE UPPER 70S IN THE MOUNTAINS TO THE LOWER 90S IN THE PIEDMONT. SCATTERED SHOWERS AND THUNDERSTORMS REDEVELOP MONDAY AFTERNOON WITH SOLAR HEATING. SOME OF THE THUNDERSTORMS MAY CONTAIN LOCALLY HEAVY RAINS. RAINFALL WILL DIMINISH QUICKLY AS THE SUN SETS AND SHOULD SEE DRY...ALBEIT WARM AND MUGGY...CONDITIONS PERSIST THROUGH MONDAY NIGHT. LOW TEMPERATURES MONDAY NIGHT WILL VARY FROM THE LOWER 60S IN THE WEST TO THE AROUND 70 IN THE EAST. DEEP LAYER MOISTURE INCREASES TUESDAY AS ANOTHER LOW PRESSURE SYSTEM MOVING ACROSS EASTERN CANADA WILL DRAG A COLD FRONT SOUTH OF THE GREAT LAKES. BETTER CHANCES FOR CONVECTION WILL BE FOUND ACROSS THE HIGHER TERRAIN...WHERE STRONGER UPPER LEVEL SUPPORT WILL BE LOCATED. HIGHS TUESDAY WILL CLIMB INTO THE LOWER 80S IN THE MOUNTAINS TO THE LOWER 90S IN THE PIEDMONT. MODEL TREND HAVE BEEN SLOWING THE TIMING OF THE FRONT AND EXPECT THE COLD FRONT WILL STALL FURTHER NORTH TUESDAY NIGHT DUE TO THE UPPER LEVEL RIDGING IN PLACE ACROSS THE SOUTHEAST STATES. LOWS WILL FALL INTO THE MID 60S TO THE LOW 70S TUESDAY NIGHT. KEPT THE HIGHEST POPS ACROSS THE SOUTH WEDNESDAY ALONG THE STALLED FRONTAL BOUNDARY. WHILE...HIGH PRESSURE PASSING ACROSS THE GREAT LAKES SHOULD KEEP THE NORTHERN HALF OF OUR AREA DRY. HIGHS WEDNESDAY WILL BE FROM THE LOWER 80S IN THE WEST TO AROUND 90 DEGREES IN THE EAST. SLOWLY DRY THINGS OUT WEDNESDAY NIGHT FROM NORTH TO SOUTH. LOW TEMPERATURES WILL DROP INTO THE UPPER 50S IN THE NORTHWEST MOUNTAINS TO NEAR 70 DEGREES IN THE PIEDMONT. && .LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 330 PM SATURDAY... UPPER LEVEL RIDGING WILL SHIFT NORTHWARD FROM THE SOUTHEAST STATES OVER THE MID ATLANTIC DURING THE SECOND HALF OF THE WEEK...RESULTING IN BOTH WARMER TEMPERATURES AND WEAKER WINDS ALOFT. THIS WILL MAKE FOR MORE STABLE CONDITIONS THAT WILL KEEP SHOWER AND THUNDERSTORM ACTIVITY DISORGANIZED THROUGH THE PERIOD. ANY RAINFALL WHICH DEVELOPS WILL BE DRIVEN MAINLY BY DAYTIME HEATING...WHICH WILL ALLOW THIS ACTIVITY TO FIZZLE AFTER SUNSET. HIGH PRESSURE WILL PASS OFF THE NEW ENGLAND COAST ON THURSDAY... RESULTING IN A WEAK WEDGING PATTERN WITH EASTERLY FLOW OFF THE ATLANTIC. THIS WILL LIKELY BE THE DRIEST DAY OF THE PERIOD. WINDS WILL SHIFT SOUTHWESTERLY AGAIN ON FRIDAY AS ANOTHER COLD FRONT SINKS SOUTH FROM THE GREAT LAKES. STRONGER FLOW OFF THE ATLANTIC WILL RESULT IN INCREASED MOISTURE...AND WILL EXPECT SPOTTY SHOWER AND THUNDERSTORM ACTIVITY DURING THE AFTERNOON AND EVENING. EXPECT TEMPERATURES TO REMAIN SLIGHTLY ABOVE NORMAL FOR THE PERIOD. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... AS OF 735 AM EDT SUNDAY... SATELLITE PICTURES SHOWED AN AREA OF IFR CLOUDS SPREADING NORTH OUT OF NORTH CAROLINA. THESE CLOUDS MAY BRIEFLY REACH KLYH OR KDAN BEFORE 10AM. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WERE MOVING NORTH- NORTHEAST ACROSS THE CENTRAL APPALACHIANS THIS MORNING. EXPECT RAIN AT KROA/KBCB AND KLWB THROUGH 14Z/10AM THIS MORNING. CEILINGS AND VISIBILITIES WILL REMAIN VFR IN ALL BUT THE HEAVIEST SHOWERS. THE PRECIPITATION WILL GRADUALLY DIMINISH THIS MORNING AS IT MOVES EAST. THERE WILL BE A BREAK IN THE PRECIPITATION THROUGH ABOUT 1PM/17Z...THEN MORE SHOWERS AND THUNDERSTORMS WILL DEVELOP. HRRR GUIDANCE SHOWED THE MOST LIKELY LOCATION FOR REDEVELOPMENT WILL BE ALONG THE BLUE RIDGE. BUT THIS WILL DEPEND ON HOW MUCH HEATING AND RESULTING INSTABILITY HAS OCCURRED. MEDIUM CONFIDENCE ON THE LOCATION OF STORMS THIS AFTERNOON AND EVENING. ONCE THE PRECIPITATION MOVES OUT OF THE AREA LATE TONIGHT...HIGH AMOUNTS OF LOW LEVEL MOISTURE...ALONG WITH SOME BREAKS IN THE CLOUD COVER WILL RESULT IN FOG FORMATION. HIGH CONFIDENCE OF MVFR FOG ACROSS THE REGION LATE TONIGHT. EXTENDED DISCUSSION... IMPULSES EXIT BY MONDAY LEAVING THE REGION IN BETWEEN THIS EXITING SYSTEM AND THE NEXT UPSTREAM COLD FRONT. THIS SHOULD ALLOW FOR MORE IN THE WAY OF WIDESPREAD VFR ON MONDAY AFTER EARLY FOG FADES...WITH ONLY ISOLATED CONVECTION LIKELY DURING THE AFTERNOON INCLUDING SPOTTY MVFR CONDITIONS. ANOTHER COLD FRONT IS EXPECTED TO PRODUCE SIMILAR CONDITIONS AS IT APPROACHES FROM THE NW TUESDAY...THEN BETTER COVERAGE OF SHRA/TSRA WEDNESDAY WITH THE FRONT PASSING...AND ACROSS THE SOUTH THURSDAY WHERE THE BOUNDARY STALLS. HOWEVER LOW CONFIDENCE ON THE TIMING AND SOUTHWARD POSITION OF THE BOUNDARY AT THIS POINT. THUS APPEARS MAINLY VFR FOR NOW TUE-THU OUTSIDE OF AFTERNOON/EVENING CONVECTION AND TYPICAL EARLY MORNING FOG IN THE VALLEYS AND WHERE EARLIER HEAVY RAIN OCCURRED. && .EQUIPMENT... AS OF 730 AM EDT FRIDAY ... THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...WILL BE OUT OF SERVICE UNTIL FURTHER NOTICE. A PART HAS BEEN BACK-ORDERED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...KK LONG TERM...NF AVIATION...AMS EQUIPMENT...AMS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
405 AM EDT SUN AUG 31 2014 .SYNOPSIS... THE REGION WILL STAY BETWEEN A LARGE HIGH PRESSURE SYSTEM OVER THE SOUTHEAST UNITED STATES AND WESTERN ATLANTIC AND A COMPLEX LOW PRESSURE SYSTEM CROSSING THE GREAT LAKES. A COLD FRONT FINALLY ARRIVES FROM THE NORTH BY THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM EDT SUNDAY... ELONGATED BAROCLINIC ZONE IS SUPPORTED BY AN UPPER JET AND AXIS OF VORTICITY THAT EXTENDS FROM THE LOWER MISSISSIPPI VALLEY TO NEW ENGLAND. UPPER RIDGE REMAINS PARKED OVER THE NORTH CAROLINA COAST. BAND OF DEEPER MOISTURE SHOWN ON WATER VAPOR AND TOTAL PRECIPITABLE WATER IMAGES WILL MAKE ONLY SLOW PROGRESS EAST INTO THE COUNTY WARNING AREA BY MONDAY MORNING. MODELS BRING CLUSTER OF SHOWERS AND THUNDERSTORMS OVER KENTUCKY AND TENNESSEE ACROSS MUCH OF THE FORECAST AREA THIS MORNING. NOT SURE HOW FAR EAST THIS PRECIPITATION WILL GET. 06Z HRRR HAD REASONABLE TIMING MOVING THE EASTERN EDGE INTO THE FORECAST AREA THROUGH 8AM SO WILL BE FOLLOWING THAT ALONG WITH RADAR TRENDS. LARGER BAND OF SHOWERS WILL PIVOT ENOUGH TO REACH SOUTHEAST WEST VIRGINIA TONIGHT...SIMILAR TO ORIENTATION OF WPC QPF FORECAST AND THE 00Z GFS...SLIGHTLY FARTHER SOUTH THAN THE 00Z NAM. 4KM NAM AND HRRR DEVELOP THUNDERSTORMS ALONG THE BLUE RIDGE THIS AFTERNOON...CLOSE TO THE EDGE OF THE THICKER CLOUD COVER. EXPECT THE COVERAGE OF THUNDERSTORMS IN THE EAST TO DIMINISH AFTER SUNSET. CLOUDS WILL LIMIT HEATING AND INSTABILITY TODAY. STAYED CLOSER TO BIAS CORRECTED MAV GUIDANCE FOR MAXIMUM TEMPERATURES. HUMID AIR MASS AND VERY MILD DEW POINTS WILL RESULT IN LITTLE COOLING TONIGHT. USED WARMER MET GUIDANCE FOR OVERNIGHT LOWS. && .SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM EDT SUNDAY... PROGRESSIVE NORTHERN STREAM FLOW WILL PRODUCE TROUGHING ACROSS THE NORTHEAST BY MONDAY MORNING. SEVERAL SHORTWAVES TRAVERSE ACROSS THE MID ATLANTIC REGION. THESE UPPER DISTURBANCES WILL SHAPE THE TIMING OF CONVECTION. AN UPPER DISTURBANCE WILL SHIFT ACROSS THE GREAT LAKES FROM THE OHIO RIVER VALLEY MONDAY MORNING...ENHANCING THE CHANCES OF SHOWERS IN THE WEST-NORTHWEST. THE SUBTROPICAL BERMUDA HIGH PRESSURE WILL REMAIN IN PLACE. A VERY MOIST SOUTHWEST FLOW WILL CONTINUE LABOR DAY. HIGH TEMPERATURES MONDAY WILL RANGE FROM THE UPPER 70S IN THE MOUNTAINS TO THE LOWER 90S IN THE PIEDMONT. SCATTERED SHOWERS AND THUNDERSTORMS REDEVELOP MONDAY AFTERNOON WITH SOLAR HEATING. SOME OF THE THUNDERSTORMS MAY CONTAIN LOCALLY HEAVY RAINS. RAINFALL WILL DIMINISH QUICKLY AS THE SUN SETS AND SHOULD SEE DRY...ALBEIT WARM AND MUGGY...CONDITIONS PERSIST THROUGH MONDAY NIGHT. LOW TEMPERATURES MONDAY NIGHT WILL VARY FROM THE LOWER 60S IN THE WEST TO THE AROUND 70 IN THE EAST. DEEP LAYER MOISTURE INCREASES TUESDAY AS ANOTHER LOW PRESSURE SYSTEM MOVING ACROSS EASTERN CANADA WILL DRAG A COLD FRONT SOUTH OF THE GREAT LAKES. BETTER CHANCES FOR CONVECTION WILL BE FOUND ACROSS THE HIGHER TERRAIN...WHERE STRONGER UPPER LEVEL SUPPORT WILL BE LOCATED. HIGHS TUESDAY WILL CLIMB INTO THE LOWER 80S IN THE MOUNTAINS TO THE LOWER 90S IN THE PIEDMONT. MODEL TREND HAVE BEEN SLOWING THE TIMING OF THE FRONT AND EXPECT THE COLD FRONT WILL STALL FURTHER NORTH TUESDAY NIGHT DUE TO THE UPPER LEVEL RIDGING IN PLACE ACROSS THE SOUTHEAST STATES. LOWS WILL FALL INTO THE MID 60S TO THE LOW 70S TUESDAY NIGHT. KEPT THE HIGHEST POPS ACROSS THE SOUTH WEDNESDAY ALONG THE STALLED FRONTAL BOUNDARY. WHILE...HIGH PRESSURE PASSING ACROSS THE GREAT LAKES SHOULD KEEP THE NORTHERN HALF OF OUR AREA DRY. HIGHS WEDNESDAY WILL BE FROM THE LOWER 80S IN THE WEST TO AROUND 90 DEGREES IN THE EAST. SLOWLY DRY THINGS OUT WEDNESDAY NIGHT FROM NORTH TO SOUTH. LOW TEMPERATURES WILL DROP INTO THE UPPER 50S IN THE NORTHWEST MOUNTAINS TO NEAR 70 DEGREES IN THE PIEDMONT. && .LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 330 PM SATURDAY... UPPER LEVEL RIDGING WILL SHIFT NORTHWARD FROM THE SOUTHEAST STATES OVER THE MID ATLANTIC DURING THE SECOND HALF OF THE WEEK...RESULTING IN BOTH WARMER TEMPERATURES AND WEAKER WINDS ALOFT. THIS WILL MAKE FOR MORE STABLE CONDITIONS THAT WILL KEEP SHOWER AND THUNDERSTORM ACTIVITY DISORGANIZED THROUGH THE PERIOD. ANY RAINFALL WHICH DEVELOPS WILL BE DRIVEN MAINLY BY DAYTIME HEATING...WHICH WILL ALLOW THIS ACTIVITY TO FIZZLE AFTER SUNSET. HIGH PRESSURE WILL PASS OFF THE NEW ENGLAND COAST ON THURSDAY... RESULTING IN A WEAK WEDGING PATTERN WITH EASTERLY FLOW OFF THE ATLANTIC. THIS WILL LIKELY BE THE DRIEST DAY OF THE PERIOD. WINDS WILL SHIFT SOUTHWESTERLY AGAIN ON FRIDAY AS ANOTHER COLD FRONT SINKS SOUTH FROM THE GREAT LAKES. STRONGER FLOW OFF THE ATLANTIC WILL RESULT IN INCREASED MOISTURE...AND WILL EXPECT SPOTTY SHOWER AND THUNDERSTORM ACTIVITY DURING THE AFTERNOON AND EVENING. EXPECT TEMPERATURES TO REMAIN SLIGHTLY ABOVE NORMAL FOR THE PERIOD. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... AS OF 125 AM EDT SUNDAY... SATELLITE PICTURES SHOWED AN EXPANSIVE BAND OF DEEP MOISTURE FROM THE GULF OF MEXICO INTO THE GREAT LAKES. AXIS OF VORTICITY ALONG THIS SAME CORRIDOR WILL GENERATE SHOWERS AND THUNDERSTORMS TODAY AND TONIGHT. ONGOING SHOWERS AND THUNDERSTORMS OVER THE TENNESSEE AND OHIO VALLEYS EARLY THIS MORNING WILL GRADUALLY MOVE EAST IN TO WEST VIRGINIA AND VIRGINIA TODAY. LOWER CONFIDENCE AS TO HOW FAR EAST THIS PRECIPITATION WILL GET BY 00Z/8PM. FOR NOW HAVE LEFT PRECIPITATION OUT OF THE KBCB AND KROA TAFS. ALSO KEPT KLYH AND KDAN DRY. HIGHER CONFIDENCE THAT KLWB AND KBLF WILL HAVE A PROLONGED PERIOD OF SHOWERS OVERNIGHT. MODELS BRING IFR CEILINGS INTO KLYH AND KDAN EARLY THIS MORNING. EXPECT ANY STRATUS THAT DOES DEVELOP WILL LIFT TO VFR SHORTLY AFTER SUNRISE. EXTENDED DISCUSSION... IMPULSES EXIT BY MONDAY LEAVING THE REGION IN BETWEEN THIS EXITING SYSTEM AND THE NEXT UPSTREAM COLD FRONT. THIS SHOULD ALLOW FOR MORE IN THE WAY OF WIDESPREAD VFR ON MONDAY AFTER EARLY FOG FADES WITH ONLY ISOLATED CONVECTION LIKELY DURING THE AFTERNOON INCLUDING SPOTTY MVFR. ANOTHER COLD FRONT IS EXPECTED TO PRODUCE SIMILAR CONDITIONS AS IT APPROACHES FROM THE NW TUESDAY...THEN PERHAPS BETTER COVERAGE OF SHRA/TSRA WEDNESDAY WITH THE FRONT PASSING...AND ACROSS THE SOUTH THURSDAY WHERE THE BOUNDARY LOOKS TO STALL. HOWEVER TIMING AND SOUTHWARD EXTENT OF THE BOUNDARY QUITE LOW CONFIDENCE AT THIS POINT. THUS APPEARS MAINLY VFR FOR NOW TUE-THU OUTSIDE OF AFTERNOON/EVENING CONVECTION AND TYPICAL EARLY MORNING FOG IN THE VALLEYS AND WHERE EARLIER HEAVY RAIN OCCURRED. && .EQUIPMENT... AS OF 730 AM EDT FRIDAY ... THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...WILL BE OUT OF SERVICE UNTIL FURTHER NOTICE. A PART HAS BEEN BACK-ORDERED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...KK LONG TERM...NF AVIATION...AMS EQUIPMENT...AMS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1050 PM CDT MON SEP 1 2014 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SYNOPSIS... ISSUED AT 233 PM CDT MON SEP 1 2014 WARM AND RATHER HUMID WITH SHOWERS AND THUNDERSTORMS AT TIMES THROUGH MOST OF THE HOLIDAY-SHORTENED WORK WEEK. STG SUBTROPICAL RIDGE ACRS THE SRN CONUS WL EXPAND NWD A BIT THE NEXT FEW DAYS AS SEASONABLY STG AND PROGRESSIVE BAND OF WESTERLIES TO IT/S N GRADUALLY RECEDES FARTHER NWD. THE PRIMARY FRONTAL ZONE SEPARATING WARM AND VERY MOIST TROPICAL AIR TO THE S FM COOLER AND DRIER CANADIAN AIR TO THE N WL REMAIN STETCHED OUT W-E ALONG THE SRN EDGE OF THE MAIN WESTERLIES...AND CLOSE TO THE FCST AREA. THIS WL RESULT IN SEVERAL OPPORTUNITIES FOR PCPN...LIKELY RESULTING IN ABV NORMAL AMNTS. TEMPS AND HUMIDITIES ARE EXPECTED TO REMAIN AOA NORMAL FOR THE NEXT SEVERAL DAYS...THEN DROP BACK CLOSE TO NORMAL BY THE WEEKEND. && .SHORT TERM...TONIGHT AND TUESDAY ISSUED AT 233 PM CDT MON SEP 1 2014 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COLD FRONT SLICING ACROSS NORTH-CENTRAL TO SOUTHWEST WISCONSIN EARLY THIS AFTERNOON. PRIMARY AREA OF RAIN AHEAD OF A SHORTWAVE HAS EXITED NORTHEAST WISCONSIN...BUT ARE SEEING SCATTERED SHOWER AND ISOLATED THUNDERSTORM DEVELOPMENT ALONG THE COLD FRONT WHERE ML CAPE VALUES ARE AROUND 400 J/KG. THIS FRONT WILL CONTINUE TO MARCH EAST THIS AFTERNOON AND REACH EAST-CENTRAL WISCONSIN BY AROUND 00Z. WILL HAVE TO KEEP A SCT SHOWER/ISOLD TSTORM MENTION AHEAD OF THE FRONT UNTIL THEN. CLEARING SKIES EXIST BEHIND THE FRONT OVER FAR WESTERN WISCONSIN AND MINNESOTA. THEN THE NEXT SHORTWAVE IS QUICKLY MOVING EAST OVER WESTERN SOUTH DAKOTA WHERE A FEW LIGHTNING STRIKES ARE OCCURRING. TIMING THE END OF PRECIP TONIGHT AND POTENTIAL FOR THUNDERSTORMS TOMORROW ARE THE MAIN FORECAST CONCERNS. TONIGHT...THE COLD FRONT WILL BE SLIDING SOUTHEAST ACROSS EAST-CENTRAL AND SOUTHERN WISCONSIN EARLY IN THE EVENING...AND WILL LEAVE A SLIGHT CHANCE OF SHOWERS OVER CALUMET...KEWAUNEE...AND MANITOWOC COUNTIES FOR THE 00-01Z PERIOD. THEN SHOULD SEE A CLEARING PERIOD THROUGH THE REST OF THE EVENING AS DRIER MID-LEVEL AIR WORKS IN FROM THE WEST. A MODESTLY TIGHT PRESSURE GRADIENT WILL BE IN PLACE FOR THE EVENING...BUT SHOULD LOOSEN OVERNIGHT...AND PROBABLY ENOUGH FOR FOG FORMATION OVER N-C WISCONSIN. NOT AS CONFIDENT ABOUT THE REST OF THE AREA AS STATISTICAL GUIDANCE IS RATHER PESSIMISTIC ABOUT THE THREAT OF FOG. WILL KEEP A PATCHY MENTION ALONG THE WIS RIVER VALLEY TOO. THE NEXT SHORTWAVE WILL BE MOVING INTO THE NORTHERN MISSISSIPPI VALLEY LATE AND SHOULD HAVE INCREASING CLOUDS TOWARDS SUNRISE. LOWS RANGING FROM THE LOW 50S NORTH TO NEAR 60S SOUTH. TUESDAY...THE SHORTWAVE TROUGH WILL MOVE ACROSS WISCONSIN DURING THE MORNING BEFORE EXITING BY MID TO LATE AFTERNOON. THERE MAY BE A SPOTTY SHOWER WITH THE WAVE EARLY IN THE MORNING...BUT WITH DAYTIME HEATING...MODELS PROJECT STEEP LOW LEVEL LAPSE RATES DEVELOPING ALL THE WAY UP TO 750MB. CONVECTIVE TEMPERATURES ARE ONLY PROJECTED TO REACH THE LOWER TO THE MIDDLE 70S...WHICH ARE SLIGHTLY BELOW THE FORECASTED MAX TEMPS FOR THE DAY. IN ADDITION...ML CAPES ARE PROJECTED TO RANGE FROM 500-1000 J/KG BY MIDDAY TO EARLY AFTERNOON WITH NO CAP IN PLACE. AS A RESULT...SHOULD SEE ISOLATED SHOWERS EARLY BECOME MORE SCATTERED BY MIDDAY AS CONVECTIVE TEMPS ARE APPROACHED. WITH THOSE CAPES...CANNOT RULE OUT THUNDERSTORMS...AND WILL KEEP A MENTION IN THE FORECAST. LOW FREEZING LEVELS AROUND 10KFT AND 0-6KM BULK SHEARS OF 30-35 KTS SUGGEST GUSTY WINDS AND SMALL HAIL WILL BE POSSIBLE WITHIN ANY THUNDERSTORMS. HIGHS RANGING FROM THE LOWER 70S NORTH TO UPPER 70S SOUTH. .LONG TERM...TUESDAY NIGHT THROUGH MONDAY ISSUED AT 233 PM CDT MON SEP 1 2014 ISOLD-SCT SHRA WL PROBABLY BE GONE BY TOMORROW NGT...SO WL START THE LONG-TERM FCST OUT DRY. WK SFC PRESSURE GRADIENT AND 10-15 KT WLY FLOW AT 850 MB WL NOT BE IDEAL FOR FOG TOMORROW NGT. BUT GIVEN RECENT RAINS...WL MENTION PATCHY FOG ACRS THE AREA AFTER MIDNIGHT. QUIET WX SHOULD AT LEAST LINGER INTO WED...AND QUITE LIKELY LAST THE WHOLE DAY. WL JUST BRUSH SOME LOW CHC POPS ACRS THE NW PART OF THE AREA IN THE AFTN IN CASE SOME CONVECTION FM THE W CAN MAKE IT THAT FAR E IN THE RELATIVELY FAST/FLAT WLY FLOW ALOFT. A 24-36 HR PERIOD OF VERY ACTIVE WX WL PROBABLY FOLLOW FOR THE LATTER HALF OF THE ABBREVIATED WORK WEEK. STG SHRTWV IN THE MAIN BAND OF WESTERLIES WL BE PROGRESSING EWD ALONG THE U.S./CANADIAN BORDER WED NGT...LIKELY RESULTING IN CYCLONGENESIS ACRS THE NRN PLAINS. STRENGTHENING LLJ WL LIKELY VEER INTO THE FCST AREA DURING THE NGT...PROBABLY BRINGING AN MCS FROM THE NRN PLAINS EWD INTO THE FCST AREA. THE MAIN RESERVOIR OF VERY MOIST AND UNSTABLE AIR WL BE TO THE SW...SO THE SVR THREAT WL MOST LIKELY REMAIN TO OUR W. BUT WL NEED TO CLOSELY MONITOR THE SITN OVER THE NEXT FEW DAYS AS THE FCST AREA WL BE ON THE ERN EDGE OF ELEVATED MIXED LAYER...WITH FAIRLY STEEP MIDDLE LEVEL LAPSE RATES EDGING IN FM THE W. AS WAS THE CASE THIS MORNING AND BACK LAST MONDAY /AUG 25/... CONVECTIVE POTENTIAL THU WL DEPEND ON THE BEHAVIOR OF THE DEPARTING NOCTURNAL CONVECTION. WHAT MAY BE DIFFERENT THIS TIME IS HIGHER UPR HEIGHTS AND STRONG WLY FLOW ALOFT DRIVING ELEVATED MIXED LAYER ACRS THE AREA...RESULTING IN VERY WARM TEMPS ALOFT AND POSSIBLY RESULTING IN STG CAPPING. ASSUMING CONVECTION SHUTS DOWN...TEMPS WL LIKELY SOAR WELL INTO THE 80S WITH DWPTS RISING INTO THE LOWER TO MIDDLE 70S. IF THAT OCCURS...A VERY VOLATILE ATM COULD BE IN PLACE AS THE COLD FRONT STARTS IT/S PUSH ACRS THE AREA THU AFTN/EVENING. TOO MANY IF/S TO GET TOO SPECIFIC WITH THE FCST THIS FAR OUT... BUT GIVEN THE OVERALL LOOK OF THE LARGE SCALE SET-UP...WL BEGIN TO OPEN THE DOOR TO SOME SVR POTENTIAL IN THE HWO. COOLER AND DRIER AIR WL PUSH INTO THE AREA IN THE WAKE OF THE FRONT...AND LIKELY LINGER INTO EARLY NEXT WEEK. NO SIG CHGS NEED TO BROAD-BASED EXTENDED FCST INITIALIZATION GRIDS. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1047 PM CDT MON SEP 1 2014 CLEARING SKIES THIS EVENING AND DIMINISHING SURFACE WINDS WILL LIKELY LEAD TO GROUND FOG FORMATION LATE TONIGHT...THOUGH STRONGER FLOW JUST OFF THE SURFACE SHOULD LIMIT EXTENT. WEAK DISTURBANCES MOVING THROUGH THE FLOW WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS BY TUESDAY MORNING. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......SKOWRONSKI SHORT TERM.....MPC LONG TERM......SKOWRONSKI AVIATION.......TE
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
700 PM CDT MON SEP 1 2014 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SYNOPSIS... ISSUED AT 233 PM CDT MON SEP 1 2014 WARM AND RATHER HUMID WITH SHOWERS AND THUNDERSTORMS AT TIMES THROUGH MOST OF THE HOLIDAY-SHORTENED WORK WEEK. STG SUBTROPICAL RIDGE ACRS THE SRN CONUS WL EXPAND NWD A BIT THE NEXT FEW DAYS AS SEASONABLY STG AND PROGRESSIVE BAND OF WESTERLIES TO IT/S N GRADUALLY RECEDES FARTHER NWD. THE PRIMARY FRONTAL ZONE SEPARATING WARM AND VERY MOIST TROPICAL AIR TO THE S FM COOLER AND DRIER CANADIAN AIR TO THE N WL REMAIN STETCHED OUT W-E ALONG THE SRN EDGE OF THE MAIN WESTERLIES...AND CLOSE TO THE FCST AREA. THIS WL RESULT IN SEVERAL OPPORTUNITIES FOR PCPN...LIKELY RESULTING IN ABV NORMAL AMNTS. TEMPS AND HUMIDITIES ARE EXPECTED TO REMAIN AOA NORMAL FOR THE NEXT SEVERAL DAYS...THEN DROP BACK CLOSE TO NORMAL BY THE WEEKEND. && .SHORT TERM...TONIGHT AND TUESDAY ISSUED AT 233 PM CDT MON SEP 1 2014 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COLD FRONT SLICING ACROSS NORTH-CENTRAL TO SOUTHWEST WISCONSIN EARLY THIS AFTERNOON. PRIMARY AREA OF RAIN AHEAD OF A SHORTWAVE HAS EXITED NORTHEAST WISCONSIN...BUT ARE SEEING SCATTERED SHOWER AND ISOLATED THUNDERSTORM DEVELOPMENT ALONG THE COLD FRONT WHERE ML CAPE VALUES ARE AROUND 400 J/KG. THIS FRONT WILL CONTINUE TO MARCH EAST THIS AFTERNOON AND REACH EAST-CENTRAL WISCONSIN BY AROUND 00Z. WILL HAVE TO KEEP A SCT SHOWER/ISOLD TSTORM MENTION AHEAD OF THE FRONT UNTIL THEN. CLEARING SKIES EXIST BEHIND THE FRONT OVER FAR WESTERN WISCONSIN AND MINNESOTA. THEN THE NEXT SHORTWAVE IS QUICKLY MOVING EAST OVER WESTERN SOUTH DAKOTA WHERE A FEW LIGHTNING STRIKES ARE OCCURRING. TIMING THE END OF PRECIP TONIGHT AND POTENTIAL FOR THUNDERSTORMS TOMORROW ARE THE MAIN FORECAST CONCERNS. TONIGHT...THE COLD FRONT WILL BE SLIDING SOUTHEAST ACROSS EAST-CENTRAL AND SOUTHERN WISCONSIN EARLY IN THE EVENING...AND WILL LEAVE A SLIGHT CHANCE OF SHOWERS OVER CALUMET...KEWAUNEE...AND MANITOWOC COUNTIES FOR THE 00-01Z PERIOD. THEN SHOULD SEE A CLEARING PERIOD THROUGH THE REST OF THE EVENING AS DRIER MID-LEVEL AIR WORKS IN FROM THE WEST. A MODESTLY TIGHT PRESSURE GRADIENT WILL BE IN PLACE FOR THE EVENING...BUT SHOULD LOOSEN OVERNIGHT...AND PROBABLY ENOUGH FOR FOG FORMATION OVER N-C WISCONSIN. NOT AS CONFIDENT ABOUT THE REST OF THE AREA AS STATISTICAL GUIDANCE IS RATHER PESSIMISTIC ABOUT THE THREAT OF FOG. WILL KEEP A PATCHY MENTION ALONG THE WIS RIVER VALLEY TOO. THE NEXT SHORTWAVE WILL BE MOVING INTO THE NORTHERN MISSISSIPPI VALLEY LATE AND SHOULD HAVE INCREASING CLOUDS TOWARDS SUNRISE. LOWS RANGING FROM THE LOW 50S NORTH TO NEAR 60S SOUTH. TUESDAY...THE SHORTWAVE TROUGH WILL MOVE ACROSS WISCONSIN DURING THE MORNING BEFORE EXITING BY MID TO LATE AFTERNOON. THERE MAY BE A SPOTTY SHOWER WITH THE WAVE EARLY IN THE MORNING...BUT WITH DAYTIME HEATING...MODELS PROJECT STEEP LOW LEVEL LAPSE RATES DEVELOPING ALL THE WAY UP TO 750MB. CONVECTIVE TEMPERATURES ARE ONLY PROJECTED TO REACH THE LOWER TO THE MIDDLE 70S...WHICH ARE SLIGHTLY BELOW THE FORECASTED MAX TEMPS FOR THE DAY. IN ADDITION...ML CAPES ARE PROJECTED TO RANGE FROM 500-1000 J/KG BY MIDDAY TO EARLY AFTERNOON WITH NO CAP IN PLACE. AS A RESULT...SHOULD SEE ISOLATED SHOWERS EARLY BECOME MORE SCATTERED BY MIDDAY AS CONVECTIVE TEMPS ARE APPROACHED. WITH THOSE CAPES...CANNOT RULE OUT THUNDERSTORMS...AND WILL KEEP A MENTION IN THE FORECAST. LOW FREEZING LEVELS AROUND 10KFT AND 0-6KM BULK SHEARS OF 30-35 KTS SUGGEST GUSTY WINDS AND SMALL HAIL WILL BE POSSIBLE WITHIN ANY THUNDERSTORMS. HIGHS RANGING FROM THE LOWER 70S NORTH TO UPPER 70S SOUTH. .LONG TERM...TUESDAY NIGHT THROUGH MONDAY ISSUED AT 233 PM CDT MON SEP 1 2014 ISOLD-SCT SHRA WL PROBABLY BE GONE BY TOMORROW NGT...SO WL START THE LONG-TERM FCST OUT DRY. WK SFC PRESSURE GRADIENT AND 10-15 KT WLY FLOW AT 850 MB WL NOT BE IDEAL FOR FOG TOMORROW NGT. BUT GIVEN RECENT RAINS...WL MENTION PATCHY FOG ACRS THE AREA AFTER MIDNIGHT. QUIET WX SHOULD AT LEAST LINGER INTO WED...AND QUITE LIKELY LAST THE WHOLE DAY. WL JUST BRUSH SOME LOW CHC POPS ACRS THE NW PART OF THE AREA IN THE AFTN IN CASE SOME CONVECTION FM THE W CAN MAKE IT THAT FAR E IN THE RELATIVELY FAST/FLAT WLY FLOW ALOFT. A 24-36 HR PERIOD OF VERY ACTIVE WX WL PROBABLY FOLLOW FOR THE LATTER HALF OF THE ABBREVIATED WORK WEEK. STG SHRTWV IN THE MAIN BAND OF WESTERLIES WL BE PROGRESSING EWD ALONG THE U.S./CANADIAN BORDER WED NGT...LIKELY RESULTING IN CYCLONGENESIS ACRS THE NRN PLAINS. STRENGTHENING LLJ WL LIKELY VEER INTO THE FCST AREA DURING THE NGT...PROBABLY BRINGING AN MCS FROM THE NRN PLAINS EWD INTO THE FCST AREA. THE MAIN RESERVOIR OF VERY MOIST AND UNSTABLE AIR WL BE TO THE SW...SO THE SVR THREAT WL MOST LIKELY REMAIN TO OUR W. BUT WL NEED TO CLOSELY MONITOR THE SITN OVER THE NEXT FEW DAYS AS THE FCST AREA WL BE ON THE ERN EDGE OF ELEVATED MIXED LAYER...WITH FAIRLY STEEP MIDDLE LEVEL LAPSE RATES EDGING IN FM THE W. AS WAS THE CASE THIS MORNING AND BACK LAST MONDAY /AUG 25/... CONVECTIVE POTENTIAL THU WL DEPEND ON THE BEHAVIOR OF THE DEPARTING NOCTURNAL CONVECTION. WHAT MAY BE DIFFERENT THIS TIME IS HIGHER UPR HEIGHTS AND STRONG WLY FLOW ALOFT DRIVING ELEVATED MIXED LAYER ACRS THE AREA...RESULTING IN VERY WARM TEMPS ALOFT AND POSSIBLY RESULTING IN STG CAPPING. ASSUMING CONVECTION SHUTS DOWN...TEMPS WL LIKELY SOAR WELL INTO THE 80S WITH DWPTS RISING INTO THE LOWER TO MIDDLE 70S. IF THAT OCCURS...A VERY VOLATILE ATM COULD BE IN PLACE AS THE COLD FRONT STARTS IT/S PUSH ACRS THE AREA THU AFTN/EVENING. TOO MANY IF/S TO GET TOO SPECIFIC WITH THE FCST THIS FAR OUT... BUT GIVEN THE OVERALL LOOK OF THE LARGE SCALE SET-UP...WL BEGIN TO OPEN THE DOOR TO SOME SVR POTENTIAL IN THE HWO. COOLER AND DRIER AIR WL PUSH INTO THE AREA IN THE WAKE OF THE FRONT...AND LIKELY LINGER INTO EARLY NEXT WEEK. NO SIG CHGS NEED TO BROAD-BASED EXTENDED FCST INITIALIZATION GRIDS. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 636 PM CDT MON SEP 1 2014 CLEARING SKIES THIS EVENING AND DIMINISHING WINDS WILL LIKELY LEAD TO GROUND FOG FORMATION LATE TONIGHT OVER N-C WISCONSIN. THE GRADIENT IS A LITTLE TIGHTER OVER CENTRAL AND EAST-CENTRAL WI SO SHOULD NOT SEE AS THICK OF FOG AS FURTHER NORTH. A WEAK DISTURBANCE WILL THEN ARRIVE TUESDAY MORNING AND WILL PROVIDE A SCT SHOWER THREAT BY MIDDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......SKOWRONSKI SHORT TERM.....MPC LONG TERM......SKOWRONSKI AVIATION.......TE
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SYNOPSIS... ISSUED AT 233 PM CDT MON SEP 1 2014 WARM AND RATHER HUMID WITH SHOWERS AND THUNDERSTORMS AT TIMES THROUGH MOST OF THE HOLIDAY-SHORTENED WORK WEEK. STG SUBTROPICAL RIDGE ACRS THE SRN CONUS WL EXPAND NWD A BIT THE NEXT FEW DAYS AS SEASONABLY STG AND PROGRESSIVE BAND OF WESTERLIES TO IT/S N GRADUALLY RECEDES FARTHER NWD. THE PRIMARY FRONTAL ZONE SEPARATING WARM AND VERY MOIST TROPICAL AIR TO THE S FM COOLER AND DRIER CANADIAN AIR TO THE N WL REMAIN STETCHED OUT W-E ALONG THE SRN EDGE OF THE MAIN WESTERLIES...AND CLOSE TO THE FCST AREA. THIS WL RESULT IN SEVERAL OPPORTUNITIES FOR PCPN...LIKELY RESULTING IN ABV NORMAL AMNTS. TEMPS AND HUMIDITIES ARE EXPECTED TO REMAIN AOA NORMAL FOR THE NEXT SEVERAL DAYS...THEN DROP BACK CLOSE TO NORMAL BY THE WEEKEND. && .SHORT TERM...TONIGHT AND TUESDAY ISSUED AT 233 PM CDT MON SEP 1 2014 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COLD FRONT SLICING ACROSS NORTH-CENTRAL TO SOUTHWEST WISCONSIN EARLY THIS AFTERNOON. PRIMARY AREA OF RAIN AHEAD OF A SHORTWAVE HAS EXITED NORTHEAST WISCONSIN...BUT ARE SEEING SCATTERED SHOWER AND ISOLATED THUNDERSTORM DEVELOPMENT ALONG THE COLD FRONT WHERE ML CAPE VALUES ARE AROUND 400 J/KG. THIS FRONT WILL CONTINUE TO MARCH EAST THIS AFTERNOON AND REACH EAST-CENTRAL WISCONSIN BY AROUND 00Z. WILL HAVE TO KEEP A SCT SHOWER/ISOLD TSTORM MENTION AHEAD OF THE FRONT UNTIL THEN. CLEARING SKIES EXIST BEHIND THE FRONT OVER FAR WESTERN WISCONSIN AND MINNESOTA. THEN THE NEXT SHORTWAVE IS QUICKLY MOVING EAST OVER WESTERN SOUTH DAKOTA WHERE A FEW LIGHTNING STRIKES ARE OCCURRING. TIMING THE END OF PRECIP TONIGHT AND POTENTIAL FOR THUNDERSTORMS TOMORROW ARE THE MAIN FORECAST CONCERNS. TONIGHT...THE COLD FRONT WILL BE SLIDING SOUTHEAST ACROSS EAST-CENTRAL AND SOUTHERN WISCONSIN EARLY IN THE EVENING...AND WILL LEAVE A SLIGHT CHANCE OF SHOWERS OVER CALUMET...KEWAUNEE...AND MANITOWOC COUNTIES FOR THE 00-01Z PERIOD. THEN SHOULD SEE A CLEARING PERIOD THROUGH THE REST OF THE EVENING AS DRIER MID-LEVEL AIR WORKS IN FROM THE WEST. A MODESTLY TIGHT PRESSURE GRADIENT WILL BE IN PLACE FOR THE EVENING...BUT SHOULD LOOSEN OVERNIGHT...AND PROBABLY ENOUGH FOR FOG FORMATION OVER N-C WISCONSIN. NOT AS CONFIDENT ABOUT THE REST OF THE AREA AS STATISTICAL GUIDANCE IS RATHER PESSIMISTIC ABOUT THE THREAT OF FOG. WILL KEEP A PATCHY MENTION ALONG THE WIS RIVER VALLEY TOO. THE NEXT SHORTWAVE WILL BE MOVING INTO THE NORTHERN MISSISSIPPI VALLEY LATE AND SHOULD HAVE INCREASING CLOUDS TOWARDS SUNRISE. LOWS RANGING FROM THE LOW 50S NORTH TO NEAR 60S SOUTH. TUESDAY...THE SHORTWAVE TROUGH WILL MOVE ACROSS WISCONSIN DURING THE MORNING BEFORE EXITING BY MID TO LATE AFTERNOON. THERE MAY BE A SPOTTY SHOWER WITH THE WAVE EARLY IN THE MORNING...BUT WITH DAYTIME HEATING...MODELS PROJECT STEEP LOW LEVEL LAPSE RATES DEVELOPING ALL THE WAY UP TO 750MB. CONVECTIVE TEMPERATURES ARE ONLY PROJECTED TO REACH THE LOWER TO THE MIDDLE 70S...WHICH ARE SLIGHTLY BELOW THE FORECASTED MAX TEMPS FOR THE DAY. IN ADDITION...ML CAPES ARE PROJECTED TO RANGE FROM 500-1000 J/KG BY MIDDAY TO EARLY AFTERNOON WITH NO CAP IN PLACE. AS A RESULT...SHOULD SEE ISOLATED SHOWERS EARLY BECOME MORE SCATTERED BY MIDDAY AS CONVECTIVE TEMPS ARE APPROACHED. WITH THOSE CAPES...CANNOT RULE OUT THUNDERSTORMS...AND WILL KEEP A MENTION IN THE FORECAST. LOW FREEZING LEVELS AROUND 10KFT AND 0-6KM BULK SHEARS OF 30-35 KTS SUGGEST GUSTY WINDS AND SMALL HAIL WILL BE POSSIBLE WITHIN ANY THUNDERSTORMS. HIGHS RANGING FROM THE LOWER 70S NORTH TO UPPER 70S SOUTH. .LONG TERM...TUESDAY NIGHT THROUGH MONDAY ISSUED AT 233 PM CDT MON SEP 1 2014 ISOLD-SCT SHRA WL PROBABLY BE GONE BY TOMORROW NGT...SO WL START THE LONG-TERM FCST OUT DRY. WK SFC PRESSURE GRADIENT AND 10-15 KT WLY FLOW AT 850 MB WL NOT BE IDEAL FOR FOG TOMORROW NGT. BUT GIVEN RECENT RAINS...WL MENTION PATCHY FOG ACRS THE AREA AFTER MIDNIGHT. QUIET WX SHOULD AT LEAST LINGER INTO WED...AND QUITE LIKELY LAST THE WHOLE DAY. WL JUST BRUSH SOME LOW CHC POPS ACRS THE NW PART OF THE AREA IN THE AFTN IN CASE SOME CONVECTION FM THE W CAN MAKE IT THAT FAR E IN THE RELATIVELY FAST/FLAT WLY FLOW ALOFT. A 24-36 HR PERIOD OF VERY ACTIVE WX WL PROBABLY FOLLOW FOR THE LATTER HALF OF THE ABBREVIATED WORK WEEK. STG SHRTWV IN THE MAIN BAND OF WESTERLIES WL BE PROGRESSING EWD ALONG THE U.S./CANADIAN BORDER WED NGT...LIKELY RESULTING IN CYCLONGENESIS ACRS THE NRN PLAINS. STRENGTHENING LLJ WL LIKELY VEER INTO THE FCST AREA DURING THE NGT...PROBABLY BRINGING AN MCS FROM THE NRN PLAINS EWD INTO THE FCST AREA. THE MAIN RESERVOIR OF VERY MOIST AND UNSTABLE AIR WL BE TO THE SW...SO THE SVR THREAT WL MOST LIKELY REMAIN TO OUR W. BUT WL NEED TO CLOSELY MONITOR THE SITN OVER THE NEXT FEW DAYS AS THE FCST AREA WL BE ON THE ERN EDGE OF ELEVATED MIXED LAYER...WITH FAIRLY STEEP MIDDLE LEVEL LAPSE RATES EDGING IN FM THE W. AS WAS THE CASE THIS MORNING AND BACK LAST MONDAY /AUG 25/... CONVECTIVE POTENTIAL THU WL DEPEND ON THE BEHAVIOR OF THE DEPARTING NOCTURNAL CONVECTION. WHAT MAY BE DIFFERENT THIS TIME IS HIGHER UPR HEIGHTS AND STRONG WLY FLOW ALOFT DRIVING ELEVATED MIXED LAYER ACRS THE AREA...RESULTING IN VERY WARM TEMPS ALOFT AND POSSIBLY RESULTING IN STG CAPPING. ASSUMING CONVECTION SHUTS DOWN...TEMPS WL LIKELY SOAR WELL INTO THE 80S WITH DWPTS RISING INTO THE LOWER TO MIDDLE 70S. IF THAT OCCURS...A VERY VOLATILE ATM COULD BE IN PLACE AS THE COLD FRONT STARTS IT/S PUSH ACRS THE AREA THU AFTN/EVENING. TOO MANY IF/S TO GET TOO SPECIFIC WITH THE FCST THIS FAR OUT... BUT GIVEN THE OVERALL LOOK OF THE LARGE SCALE SET-UP...WL BEGIN TO OPEN THE DOOR TO SOME SVR POTENTIAL IN THE HWO. COOLER AND DRIER AIR WL PUSH INTO THE AREA IN THE WAKE OF THE FRONT...AND LIKELY LINGER INTO EARLY NEXT WEEK. NO SIG CHGS NEED TO BROAD-BASED EXTENDED FCST INITIALIZATION GRIDS. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1156 AM CDT MON SEP 1 2014 THE MAIN AREA OF SHOWERS AND ISOLATED THUNDERSTORMS WILL EXIT NORTHEAST WISCONSIN EARLY THIS AFTERNOON. SOME SPOTTY SHOWERS ALONG THE FRONT WILL LIKELY PASS OVER CENTRAL AND NORTH-CENTRAL WISCONSIN THIS AFTERNOON BUT NOT SURE OF COVERAGE...SO LEFT OUT OF TAF SITES FOR NOW. MVFR CIGS WILL TAKE A LITTLE LONGER TO MOVE OUT...HOWEVER...BUT SHOULD STILL SEE CIGS IMPROVE MID TO LATE IN THE AFTERNOON. CLEARING SKIES THIS EVENING AND DIMINISHING WINDS WILL LIKELY LEAD TO GROUND FOG FORMATION LATE TONIGHT OVER N-C WISCONSIN. THE GRADIENT IS A LITTLE TIGHTER OVER CENTRAL AND EAST-CENTRAL WI SO SHOULD NOT SEE AS THICK OF FOG AS FURTHER NORTH. A WEAK DISTURBANCE WILL THEN ARRIVE TUESDAY MORNING AND WILL PROVIDE A SCT SHOWER THREAT BY MIDDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... BEACH HAZARDS STATEMENT UNTIL 9 PM CDT THIS EVENING FOR WIZ022- 040-050. && $$ SYNOPSIS.......SKOWRONSKI SHORT TERM.....MPC LONG TERM......SKOWRONSKI AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1110 PM MDT MON SEP 1 2014 .UPDATE... ISSUED AT 558 PM MDT MON SEP 1 2014 UPDATED TO PULL POPS ACROSS THE PLAINS THIS EVENING BASED ON RADAR AND RECENT HI-RES MODEL DATA. MOISTURE AND LOW CLOUDS MAY BE POSSIBLE OVER THE FAR SOUTHEAST PLAINS LATE TONIGHT INTO TUESDAY MORNING...BUT NO PRECIP IS EXPECTED AT THIS TIME. MOZLEY && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 240 PM MDT MON SEP 1 2014 MAIN NEAR/SHORT-TERM METEOROLOGICAL ISSUES ARE TEMPERATURES...LOCALIZED GUSTY WINDS AT TIMES AND LOCALIZED LOW- GRADE POPS. CWFA EXPERIENCING NEAR SEASONAL SEPTEMBER AFTERNOON TEMPERATURES IN COMBINATION WITH GENERALLY SUNNY SKIES...ALTHOUGH SOME VARIABLE CLOUDS NOTED OVER PRIMARILY HIGHER TERRAIN LOCATIONS. IN ADDITION...WIND GUSTS EXCEEDING 30 MPH AT TIMES HAVE BEEN OBSERVED OVER THE MOUNTAINS OF CHAFFEE COUNTY. RECENT RADAR RETURNS INDICATE SHOWERS AND THUNDERSTORMS NEARING FAR NORTHEASTERN COLORADO...WELL NORTH OF OUR CWFA. LATEST COMPUTER SIMULATIONS...REAL-TIME DATA AND FORECAST MODEL SOUNDINGS INDICATE THAT GENERALLY DRY CONDITIONS SHOULD CONTINUE OVER THE MAJORITY OF THE FORECAST DISTRICT FROM LATE THIS AFTERNOON INTO TUESDAY AFTERNOON...ALTHOUGH RECENT HRRR MODEL DATA SUGGESTS THAT SHOWERS AND THUNDERSTORMS MAY THREATEN PORTIONS OF NORTHERN EL PASO AND KIOWA COUNTIES AS WELL AS SECTIONS OF LAS ANIMAS AND BACA COUNTIES FROM LATER THIS AFTERNOON INTO THIS EVENING. FOR TUESDAY...THE HIGHEST PROBABILITY OF ISOLATED SHOWER AND THUNDERSTORM ACTIVITY SHOULD BE NOTED OVER WESTERN HIGHER TERRAIN LOCATIONS...PRIMARILY DURING THE AFTERNOON AND EVENING HOURS. GUSTY...PRIMARILY HIGHER TERRAIN WINDS ARE ALSO ANTICIPATED AT TIMES FROM LATER THIS AFTERNOON INTO TUESDAY WHILE ABOVE SEASONAL EARLY SEPTEMBER AFTERNOON TEMPERATURES ARE PROJECTED TUESDAY. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 240 PM MDT MON SEP 1 2014 ...HOT WITH LOW THUNDERSTORM CHANCES THROUGH EARLY THURSDAY THEN COOLER WITH INCREASING THUNDERSTORM CHANCES... TUESDAY EVENING INTO EARLY THURSDAY...THE AIR MASS OVER THE REGION WILL BE QUITE WARM AND THE THUNDERSTORM CHANCES WILL BE LOW. COULD BE SOME SPOTTY DRY THUNDERSTORMS AROUND TUESDAY EVENING...MAINLY OVER THE MOUNTAINS. THEN...WEDNESDAY AFTERNOON...COULD BE SOME SPOTTY DRY LINE ACTIVITY ACROSS THE FAR SOUTHEAST PLAINS. MODELS HAVE BEEN BACK AND FORTH ON THIS SO CONFIDENCE IS A LITTLE LOW BUT THE POSSIBILITY REMAINS ALIVE. ON THURSDAY...THINGS START TO TRANSITION TO A COOLER...WETTER PATTERN. MODELS HAVE BEEN PRETTY CONSISTENT ON THIS SO CONFIDENCE IS INCREASING. IT STARTS WITH THE ARRIVAL OF A COLD FRONT THROUGH THE EASTERN PLAINS THURSDAY AFTERNOON. THE FRONT PUSHES INTO THE REGION AS THE RESULT OF AN UPPER DISTURBANCE MOVING THROUGH THE NORTHERN ROCKIES AND PLAINS. AS THE FRONT MOVES IN...MOIST UPSLOPE WINDS BEHIND THE FRONT GRADUALLY FIRE THUNDERSTORMS OVER AND NEAR THE MOUNTAINS IN THE AFTERNOON...SOME OF WHICH WORK EAST ACROSS THE PLAINS BY LATE IN THE DAY. WITH ADDED MOISTURE IN THE AIR AND UPSLOPE WINDS...THE THREAT FOR STRONG STORMS WILL INCREASE THIS DAY. FRIDAY THROUGH MONDAY...WE COULD BE DEALING WITH SOME RICH SUBTROPICAL MOISTURE AT TIMES...JUST DEPENDING ON HOW THINGS TRACK OVER THE NEXT FEW DAYS. RIGHT NOW...INDICATIONS ARE THAT FRIDAY AND SATURDAY COULD BOTH BE PRETTY WET OVER THE REGION WITH CONCERNS OF FLASH FLOODING. SUNDAY AND MONDAY STILL LOOK PRETTY WET FOR THE MOUNTAINS...BUT THE PLAINS LOOK MORE STABLE WITH LESS ACTIVITY. ALL OF THIS IS STILL SEVERAL DAYS AWAY AND HIGHLY SUBJECT TO CHANGE...HOWEVER. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1108 PM MDT MON SEP 1 2014 VFR CONDITIONS AT ALL THREE TERMINALS THROUGH THE NEXT 24 HOURS. WINDS WILL BE DIURNALLY DRIVEN AND SHOULD REMAIN IN THE 10-15 KT RANGE ON TUESDAY AFTERNOON ACROSS THE REGION. AN ISOLATED THUNDERSTORM IS POSSIBLE ALONG THE CONTINENTAL DIVIDE TUESDAY AFTERNOON WITH A VERY LOW PROBABILITY OF IMPACT AT KALS. MOZLEY && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MOZLEY SHORT TERM...77 LONG TERM...LW AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
345 AM EDT TUE SEP 2 2014 .CURRENTLY...WEAK HIGH PRES EXISTS OVER EXTREME S GA WITH WEAK TROUGH NEAR COASTAL GA. DEBRIS CLOUDS CONTINUE TO DISSIPATE AS LATE NIGHT CONVECTION LINGERED LATE TONIGHT OVER INLAND AREAS. SLOW DISSIPATION OF CLOUDS WILL ENSURE INLAND TEMPS WILL ONLY STEADILY DECREASE TOWARD SUNRISE. ALOFT...MID LEVEL HIGH IS LOCATED OVER SRN GA AS WELL...WITH NEARLY ZONAL FLOW OVER NE FL. SOME PATCHY FOG IS BEING REPORTED NOW AND INCLUDED IN THE LATEST FCST BY SUNRISE. A FEW SHOWERS ARE LOCATED AROUND 60 NM OR MORE OFFSHORE AND WILL LIKELY PUSH A LITTLE FURTHER EWD OVER THE NEXT FEW HRS. .SHORT TERM... TODAY...A FAIRLY SIMILAR PATTERN TO YESTERDAY WITH MEAN LAYER HIGH PRES CONTINUING JUST NW OF THE AREA AND MEAN FLOW FROM THE NE AND E. MODELS GENERALLY SHOW THE E COAST SEA BREEZE FIRING SOME CONVECTION BY LATE MORNING AND EARLY AFTN...PERHAPS A BIT EARLIER THAN PRIOR DAYS. ISOLD TO SCT SHOWERS AND STORMS ARE FCST TO DEVELOP OVER THE ERN ZONES BY NOON-1PM AND THEN GRADUALLY BLOSSOM AND DRIFT INLAND AROUND 5 TO 10 MPH. THE HRRR MODEL SHOWS DEEPEST MOISTURE OVER SE GA AND PORTIONS OF NE FL LATER TODAY AND WILL PLACE HIGH END CHANCE TO LIKELY POPS IN THESE AREAS...MAINLY AFTER 2 PM. WARM TEMPS AT 850 MB AROUND 18/19C STILL SUPPORT HIGHS IN THE LOWER TO MID 90S...YIELDING HEAT INDICES UP TO 105 IN SE GA. PRECIP WILL SLOWLY FADE TONIGHT WITH SCT COVERAGE INLAND AND MORE ISOLD TOWARD THE COAST. PATCHY FOG WILL BE POSSIBLE FOR INLAND AREAS LATE IN THE NIGHT...USING CONSENSUS OF GUIDANCE TOOLS. WEDNESDAY...SOMEWHAT OF A TRANSITION DAY AS TROPICAL UPPER LEVEL TROUGH OVER THE FL STRAITS AND BAHAMAS PUSHES WWD WHILE MID LEVEL HIGH OVER GA LIFTS SLIGHTLY NWD. THIS SCENARIO WILL INCREASE MEAN ELY WINDS AND ALLOW A QUICKER PUSH OF THE E COAST SEA BREEZE. INITIALLY HIGH PWATS WILL DECREASE DURING THE LATTER HALF OF THE DAY ACROSS OUR SERN ZONES AS A DRY SLOT MOVES NWWD OVER CENTRAL FL AND EVENTUALLY INTO OUR SRN ZONES. OVERALL...A BIT LESS COVERAGE OF SHOWERS AND STORMS...ESPECIALLY FOR THE COASTAL ZONES. RAIN CHANCES PROGGED AT 20-30% COASTAL COUNTIES AND 30-40% INLAND. HIGHS AGAIN IN THE LOWER TO MID 90S. .LONG TERM...DEEPER MOISTURE WILL START ADVECT INTO THE REGION BY LATE WEDNESDAY AND CONTINUE MORE EARNESTLY THROUGH THE END OF THE WEEK. INVERTED MEAN MID LAYER INVERTED TROF AND TUTT WILL APPROACH AND MOVE THROUGH THE REGION AND RESIDE EAST OF THE FL PENINSULA BY EARLY THURSDAY. BEHIND THIS FEATURE ABOVE NORMAL CHANCES OF PRECIPITATION...ESPECIALLY ACROSS NE FL WITH HIGHER END CHANCE OF POPS THURSDAY AND FRIDAY AFTERNOON AND EARLY EVENING. GOING INTO NEXT WEEKEND THE UPPER LEVEL RIDGE AXIS MAINTAINS THE SAME POSITION AS THE CURRENT WX PATTERN WITH HIGH PRESSURE OVER SOUTHERN GEORGIA. THIS MEAN HIGH PRESSURE AREA SLIDES NORTHEASTWARD OVER THE NE SEABOARD DURING THE BEGINNING OF NEXT WEEK. THIS WILL ALLOW LIGHTER SLY SFC WINDS TO CONTINUE EARLY NEXT WEEK WITH MERGING SEA BREEZES IN THE AFTERNOON AND EARLY EVENING HOURS. ELECTED TO KEEP SCATTERED SHWRS AND TSTMS NEXT WEEK WITH DEEP MOISTURE REMAINING INTACT. TEMPERATURES WITHIN A COUPLE DEGREES OF NORMAL WILL PREVAIL. && .AVIATION...PREVAILING VFR TODAY. OCNL MVFR VSBY EXPECTED AROUND GNV AND VQQ TERMINALS 08Z-12Z. WITH POPS GENERALLY AT OR BELOW 50% WILL MAINTAIN VCTS TSTMS EXCEPT FOR GNV WHERE PROBS ARE SUFFICIENTLY HIGH TO GO WITH TEMPO GROUP BY 21Z. && .MARINE...S/SE WINDS UNDER 15 KT WILL PREVAIL INTO THE UPCOMING WEEKEND WITH SEAS MAINLY 2-3 FT. ISOLATED SHOWERS/TSTMS WILL PREVAIL THROUGH MIDWEEK...WITH SOME INCREASE LATE WEEK AS A WEAK WAVE APPROACHES THE WATERS. RIP CURRENTS: GENERAL LOW RISK THROUGH WEDNESDAY WITH FAIRLY SMALL SWELLS AROUND 1-2 FT AND WEAK ONSHORE EXCEPT FOR BRIEF WIND INCREASE ASSOCD E COAST SEA BREEZE IN THE AFTERNOONS. && .PRELIMINARY POINT TEMPS/POPS... AMG 95 73 95 73 / 60 30 40 30 SSI 89 76 88 76 / 30 10 20 10 JAX 92 73 92 73 / 40 20 30 20 SGJ 88 74 88 75 / 30 10 20 10 GNV 92 71 92 71 / 50 30 30 30 OCF 92 71 93 71 / 50 30 40 40 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ SHASHY/CORDERO
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
358 AM CDT TUE SEP 2 2014 ...UPDATED SHORT TERM SECTION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 357 AM CDT TUE SEP 2 2014 AS OF 0845 UTC, STRONG THUNDERSTORMS WERE UNDERWAY ACROSS COMANCHE, BARBER, AND CLARK COUNTY, TIED MOST CLOSELY TO A ZONE OF FRONTOGENESIS AT AROUND 750MB STRETCHING FROM THE OKLAHOMA PANHANDLE EAST- NORTHEASTWARD TO FAR SOUTH-CENTRAL KANSAS. THE HIRES CONVECTIVE- ALLOWING MODELS PICKED UP ON THIS QUITE WELL IN THE COMPOSITE REFLECTIVITY AND QPF FIELDS. THESE MODELS SHOW THE CONVECTION MOVING OFF INTO NORTHERN OKLAHOMA BEFORE 1200 UTC, SO WE WILL TAPER THE POPS DOWN AROUND THIS TIME. EARLIER IN THE SHIFT, WE ADDED SOME AREAS OF 1/2SM FOG GENERALLY ALONG/SOUTH OF THE ARKANSAS RIVER IN A ZONE OF SATURATED SURFACE AIR NORTH OF THE WEAK SURFACE LOW. ANY FOG WHICH DEVELOPS SHOULD ERODE NOT TOO LONG AFTER SUNRISE, HOWEVER LOW STRATUS IS EXPECTED TO HOLD ON THROUGH LATE MORNING NORTH OF THE 850MB LOW. THIS MAY THROW A BIT OF A CURVE BALL IN THE TEMPERATURES TODAY, SO WE ADJUSTED THEM DOWN (USING A MODIFIED HRRR SOLUTION) OUT ACROSS THE WESTERN HALF FOR THE FIRST HALF OF THE DAY WITH CLOUDS KEEPING A LID IN THE WARM- UP. ONCE THE CLOUDS ERODE COMPLETELY BY MIDDAY/EARLY AFTERNOON, TEMPERATURES WILL WARM INTO THE MID 80S. ANY SURFACE-BASED CONVECTION LATE THIS AFTERNOON WILL BE DOWN ALONG THE SURFACE FRONT ACROSS NORTHWEST OKLAHOMA. BY EARLY EVENING, SOME OF THE THUNDERSTORM ACTIVITY MAY HEAD UP INTO BARBER COUNTY AND EXPAND IN COVERAGE SOME AS LOW LEVEL JET STRENGTHENS AFTER SUNSET. RICH LOW LEVEL MOISTURE LEADING TO 2000-3000 J/KG MOST-UNSTABLE CAPE WILL SUPPORT RENEWED SEVERE WEATHER RISK, EVEN WITH ELEVATED STORMS DURING THE LATE NIGHT HOURS TONIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 326 AM CDT TUE SEP 2 2014 THE LONGWAVE SYNOPTIC FLOW PATTERN WILL BE SOMEWHAT PROGRESSIVE THROUGH THIS FORECAST, AT LEAST ENOUGH TO BRING SIGNIFICANT SENSIBLE WEATHER CHANGES TO THE AREA FOR LATE IN THE WEEK. WEDNESDAY AND THURSDAY WILL SEE SUNNY AND VERY WARM TO HOT TEMPERATURES, AS THE UPPER JET LIFTS NORTHWARD ACROSS THE NORTHERN TIER OF STATES ALLOWING THE LARGE SOUTHERN ROCKIES/SOUTHERN PLAINS HIGH PROVIDE STRONG SUBSIDENCE, FULL INSOLATION AND SOUTHERLY SURFACE WINDS. THE ECMWF/GFS AND NAM ARE IN EXCELLENT AGREEMENT IN BREAKING DOWN THIS PATTERN BY THURSDAY AND BRINGING A COLD FRONT THROUGH THE NORTHERN PLAINS OF WESTERN NEBRASKA AND AS FAR SOUTH AS WEST CENTRAL KANSAS WITH THE LEADING COOLER AIR SURGE BY THURSDAY AFTERNOON. CONVECTION COULD OCCUR LATE THURSDAY AFTERNOON OR EVENING AS WELL WITH THIS COLD FRONT FEATURE, BUT UPPER SUPPORT/DYNAMICS FOR WIDESPREAD STORM DEVELOPMENT IS LACKING. THE UPPER JET WILL SINK SOUTHWARD THROUGH THE CENTRAL PLAINS AND CENTRAL MISSISSIPPI VALLEY, DRIVING THE COLD FRONT FARTHER SOUTH INTO THE SOUTHERN PLAINS BY SATURDAY MORNING. THE RESULT WILL BE ADDITONAL CHANCES FOR POSSIBLY EVEN SEVERE STORMS, BUT PERHAPS JUST POST SURFACE FRONTAL HIGH BASED CONVECTION FROM MID LEVEL FRONTOGENESIS FRIDAY OR FRIDAY NIGHT WITH MUCH MORE PLEASANT TEMPERATURES IN THE 70S. A SLOW WARMING TREND IS LIKELY THROUGH THE LATE PART OF THE WEEKEND INTO EARLY NEXT WEEK AS RETURN SOUTHERLY FLOW BECOMES REESTABLISHED. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1249 AM CDT TUE SEP 2 2014 SCATTERED SHOWERS AND THUNDERSTORMS ALONG AN ELEVATED FRONTAL BOUNDARY ABOUT 7000 FT AGL WILL BE CLOSE ENOUGH TO GCK, DDC, AND EVEN HYS TO JUSTIFY A VCTS GROUP FOR A FEW HOURS OVERNIGHT. OTHERWISE, WE EXPECT SOME LOW STRATUS TO DEVELOP IN WEAK, BUT MOIST UPSLOPE FLOW, ESPECIALLY AT GCK AND DDC, SO WE WILL INCLUDE SOME IFR (AND BRIEFLY LIFR AT GCK) IN THE 10-14Z TIME FRAME ROUGHLY. THE STRATUS LAYER WILL LIFT IN CEILING AFTER SUNRISE, HOWEVER IT IS STILL SOMEWHAT UNCLEAR HOW LONG IT WILL TAKE TO SCATTER OUT. SOME OF THIS LOW STRATUS WILL ADVECT NORTHWARD TO HYS LATE MORNING, SO WE WILL FORECAST SOME MVFR 1000-1500 CEILING FROM LATE MORNING UNTIL EARLY AFTERNOON UP THERE. && .PRELIMINARY POINT TEMPS/POPS... DDC 87 68 98 71 / 20 10 0 0 GCK 87 67 100 71 / 10 10 0 10 EHA 87 66 99 69 / 10 0 10 10 LBL 87 69 100 72 / 10 10 0 10 HYS 86 67 99 73 / 10 10 10 10 P28 90 72 98 74 / 40 30 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...UMSCHEID LONG TERM...RUSSELL AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1155 PM CDT Mon Sep 1 2014 ...Update to aviation forecast discussion... .SHORT TERM...(This Evening through Tuesday) Issued at 319 PM CDT MON SEP 1 2014 Quick cyclonic upper flow remains in place with the core of last night`s wave already in the Great Lakes and another weaker wave coming into the High Plains per recent water vapor imagery. The cold front`s location is hard to nail down behind outflow from the overnight convection and weak pressure fields, but appears to be bisecting the local area from southwest to northeast. Lower cloud under a modest inversion has been rather prevalent today, keeping temps in the 70s. Modest convergence persists in east central Kansas this afternoon. With still some CIN remaining per RAP analysis, confirmed by recent visible satellite imagery, and the western upper wave staying well north, storm chances don`t look great, but will maintain some mention ahead of the front in east central Kansas, diminishing with time as weak high pressure continues to move across northern sections of the state. There are some breaks in the clouds to the south, and some increase in instability is anticipated for the next few hours. Deep layer is not very high in the weak low level wind fields, but hard to completely rule out with mixed layer CAPE likely rising to near 1500 J/kg. As the surface high builds in, winds should be rather light, and depending on cloud trends particularly with convection, a fairly good setup for radiational fog will be in place with cloudy skies and limited mixing today and low cloud scouring out following the recent heavy rain. Will go ahead with some patchy fog mention at this point and let later shifts watch trends. Storm chances continue to look like Tuesday but with the boundary again possibly not far south, will keep a small chance near it. Better mixing and insolation should yield highs back into the 80s. .LONG TERM...(Tuesday Night through Monday) Issued at 319 PM CDT MON SEP 1 2014 Models continue to show the potential for elevated thunderstorms and large hail Tuesday night. The one wrinkle is the NAM appears to be quite a bit stronger in magnitude for both the elevated instability and effective shear. There is still good theta-e advection along the nose of the low level jet as well as isentropic upglide, so I think there should be some storms over eastern KS. The question is whether they will be strong enough to produce severe hail. Have continued with a chance POP through the night and think the potential still exists for some severe storms. It just may be more marginal than the NAM would suggest. With the exception of some elevated precip possibly lingering through the morning Wednesday, the forecast should quiet down as the models keep the jet stream and synoptic scale energy north of the forecast through Thursday morning. By Thursday night, a frontal system is projected to begin moving into the area. There is some uncertainty in the timing of the frontal system as most solutions have trended faster with the front, the NAM being the fastest. For now I`ve not made many changes from the previous forecast thinking the front would move through mainly Friday and Friday evening with the higher chances for precip in these periods. However if the faster trend continues, the POPs may need to be pushed up in the forecast as well. Have continued to trend POPs down for Saturday and kept a dry forecast for Sunday with models showing surface ridging and relatively dryer air over KS. By Monday, there is some disagreement with the GFS and ECMWF in the amplification of an upper trough across the west. Because the GFS is the more amplified solution, it is quick to set up return flow with the potential for shortwaves within southwesterly flow aloft to pass near the area. Have taken a conservative approach with the forecast at this time and have introduced only a slight chance for precip on Monday until there is a little more agreement in solutions. Temps will remain quite warm Wednesday and Thursday as the models show the thermal ridge over portions of the state. Because of this have continued with highs in the 90s and lows from around 70 to the mid 70s. Cold air advection is expected to increase Thursday night as the front moves through the area. This should bring a cool down for the weekend with highs in the 70s and lows in the 50s to around 60. && .AVIATION...(For the 06Z TAFs through 06Z Tuesday Night) Issued at 1149 PM CDT MON SEP 1 2014 Elevated thunderstorms have moved well south and east of the taf sites. Mid and high level clouds have blanketed the area from the convection in southern KS, but they are slowly progressing eastward. Once the clouds clear out there maybe brief periods of patchy especially during calm winds in the predawn hours. Although the forecast winds just above the surface may inhibit fog development. Therefore did not add any tempo for dense fog at this time. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...65 LONG TERM...Wolters AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS JACKSON KY
418 AM EDT TUE SEP 2 2014 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 330 AM EDT TUE SEP 2 2014 PRESENTLY...A SHORTWAVE TROUGH IS PUSHING INTO THE OHIO RIVER VALLEY REGION. AN MCS DEVELOPED YESTERDAY EVENING HEAD OF THIS TROUGH AND IS NOW MARCHING EASTWARD INTO CENTRAL/SOUTHERN INDIANA...STRETCHING BACK TO THE SOUTHWEST ACROSS SOUTHERN ILLINOIS. IR SATELLITE HAS SHOWN SOME WARMING WITH THE CLOUD TOPS OVER THE PAST HOUR OR TWO...INDICATING THAT THIS MCS MAY ALREADY BE ON THE DECLINE. IN FACT...THE HRRR SUPPORTS THE IDEA OF A DYING MCS AS IT TRIES TO PUSH INTO CENTRAL KENTUCKY TOWARDS DAYBREAK. CANNOT RULE OUT A FEW SHOWERS PUSHING INTO THE BLUEGRASS SHORTLY AFTER 8 AM...BUT ANTICIPATE MORE OF THE ACTION WITH THE SHORTWAVE TROUGH WILL COME LATER THIS AFTERNOON AS WE GENERATE SOME INSTABILITY. WITH THIS IN MIND...PLAN TO BACK OFF THE POPS THROUGH MIDDAY WITH JUST SOME ISOLATED SHOWERS FOR AREAS NORTH OF I-64. OUTFLOW FROM THE DYING MCS WILL BE PUSHING ACROSS EASTERN KENTUCKY EARLY THIS AFTERNOON...AND COULD KICK START THE CONVECTION AS IT ENCOUNTERS SOME DECENT INSTABILITY. THE FORCING ALOFT SHOULD ALLOW FOR FAIRLY GOOD SHOWER AND THUNDERSTORM COVERAGE BY MID TO LATE AFTERNOON. WITH BULK SHEAR VALUES OF 30-40KTS THIS AFTERNOON...A SEVERE THREAT WOULD EXIST AS THUNDERSTORMS COULD PUT OUT SOME DAMAGING WIND GUSTS. THE SHEAR PROFILES WEAKEN BY MID EVENING AND THE LOSS OF DAYTIME INSTABILITY SHOULD YIELD WEAKENING STORMS AFTER 6 PM. HOWEVER...A FEW GUSTY WINDS MAY STILL BE POSSIBLE THROUGH 8 OR 9 PM. THE SHORTWAVE TROUGH WILL STALL A COLD FRONT ACROSS SOUTHERN KENTUCKY BY LATE THIS EVENING. GIVEN THE PRESENCE OF THIS BOUNDARY...AND PLENTY OF MOISTURE...IT MAY BE POSSIBLE TO SEE ISOLATED SHOWERS THROUGH THE NIGHT ACROSS THE SOUTHERN HALF OF KENTUCKY. THIS BOUNDARY WILL LINGER AROUND INTO WEDNESDAY AND WITH INSTABILITY AGAIN RAMPING UP DURING THE AFTERNOON...WE COULD BE LOOKING AT A FEW MORE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. HOWEVER...BY WEDNESDAY...VERY LITTLE SHEAR IS PRESENT...SO WE SHOULD SEE MORE ORDINARY THUNDERSTORMS WITH NO SEVERE THREAT. TEMPERATURES OVER THE NEXT 2 DAYS SHOULD BE FAIRLY SIMILAR TO WHAT WE HAVE SEEN LATELY WITH HIGHS INTO THE LOW TO MID 80S. SAME CAN BE SAID FOR LOWS TONIGHT WITH READINGS GENERALLY AROUND 70. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 418 AM EDT TUE SEP 2 2014 THE FRONTAL BOUNDARY REFERENCED IN THE SHORT TERM WILL BE DISSOLVING EARLY IN THE LONG TERM PERIOD...BUT THERE SHOULD STILL BE DRY AIR IN PLACE WEDNESDAY NIGHT...ESPECIALLY ALOFT. IF ANY CONVECTIVE PRECIP CAN DEVELOP OFF OF LOW LEVEL MOISTURE ON WEDNESDAY AFTERNOON...IT SHOULD DIE OUT BY NIGHT AS HEATING IS LOST AND SUPPORT ALOFT WILL LIKELY BE LACKING. DEEPER MOISTURE WILL MAKE A COMEBACK LATE IN THE WEEK AND MAY FUEL A RESURGENCE OF SHOWERS AND THUNDERSTORMS...BUT A SUBTROPICAL RIDGE ALOFT OVER THE SE CONUS WILL HELP TO KEEP COVERAGE LIMITED FOR A WHILE. THE RIDGE WILL WEAKEN AND GET SUPPRESSED BY A BROAD TROUGH DROPPING SE INTO THE NE CONUS DURING THE WEEKEND. THIS WILL ALLOW A COLD FRONT TO MOVE INTO OUR REGION FROM THE NW. THE SCENARIO WILL ALLOW AN INCREASE IN PRECIP COVERAGE...WITH A PEAK EXPECTED ON SATURDAY. EVEN THOUGH THE FRONT SHOULD PASS BY SUNDAY...THE MODELS STILL LEAVE SOME QUESTION AS TO HOW EFFECTIVE THE FRONT WILL BE AT BRINGING IN A DRIER AIR MASS. HAVE HELD ONTO LOW POPS IN THE AFTERNOON AND EVENING ON SUNDAY AND MONDAY...ESPECIALLY IN OUR SE COUNTIES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 207 AM EDT TUE SEP 2 2014 MAINLY VFR CONDITIONS ARE EXPECTED AT THE TAF SITES OVER THE NEXT 24 TO 36 HOURS. A WEAK COLD FRONT WILL DROP SOUTH INTO EASTERN KENTUCKY TODAY AND COULD SPAWN SCATTERED TO NUMEROUS THUNDERSTORMS. PLAN TO STICK WITH THE VCTS THIS AFTERNOON AS TIMING AND UNCERTAINTY ARE TOO GREAT TO GO WITH A THUNDERSTORM PREVAILING GROUP. ACTIVITY SHOULD WANE BY MID TO LATE EVENING WITH A QUIET NIGHT EXPECTED TONIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KAS LONG TERM...HAL AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
330 AM EDT TUE SEP 2 2014 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 330 AM EDT TUE SEP 2 2014 PRESENTLY...A SHORTWAVE TROUGH IS PUSHING INTO THE OHIO RIVER VALLEY REGION. AN MCS DEVELOPED YESTERDAY EVENING HEAD OF THIS TROUGH AND IS NOW MARCHING EASTWARD INTO CENTRAL/SOUTHERN INDIANA...STRETCHING BACK TO THE SOUTHWEST ACROSS SOUTHERN ILLINOIS. IR SATELLITE HAS SHOWN SOME WARMING WITH THE CLOUD TOPS OVER THE PAST HOUR OR TWO...INDICATING THAT THIS MCS MAY ALREADY BE ON THE DECLINE. IN FACT...THE HRRR SUPPORTS THE IDEA OF A DYING MCS AS IT TRIES TO PUSH INTO CENTRAL KENTUCKY TOWARDS DAYBREAK. CANNOT RULE OUT A FEW SHOWERS PUSHING INTO THE BLUEGRASS SHORTLY AFTER 8 AM...BUT ANTICIPATE MORE OF THE ACTION WITH THE SHORTWAVE TROUGH WILL COME LATER THIS AFTERNOON AS WE GENERATE SOME INSTABILITY. WITH THIS IN MIND...PLAN TO BACK OFF THE POPS THROUGH MIDDAY WITH JUST SOME ISOLATED SHOWERS FOR AREAS NORTH OF I-64. OUTFLOW FROM THE DYING MCS WILL BE PUSHING ACROSS EASTERN KENTUCKY EARLY THIS AFTERNOON...AND COULD KICK START THE CONVECTION AS IT ENCOUNTERS SOME DECENT INSTABILITY. THE FORCING ALOFT SHOULD ALLOW FOR FAIRLY GOOD SHOWER AND THUNDERSTORM COVERAGE BY MID TO LATE AFTERNOON. WITH BULK SHEAR VALUES OF 30-40KTS THIS AFTERNOON...A SEVERE THREAT WOULD EXIST AS THUNDERSTORMS COULD PUT OUT SOME DAMAGING WIND GUSTS. THE SHEAR PROFILES WEAKEN BY MID EVENING AND THE LOSS OF DAYTIME INSTABILITY SHOULD YIELD WEAKENING STORMS AFTER 6 PM. HOWEVER...A FEW GUSTY WINDS MAY STILL BE POSSIBLE THROUGH 8 OR 9 PM. THE SHORTWAVE TROUGH WILL STALL A COLD FRONT ACROSS SOUTHERN KENTUCKY BY LATE THIS EVENING. GIVEN THE PRESENCE OF THIS BOUNDARY...AND PLENTY OF MOISTURE...IT MAY BE POSSIBLE TO SEE ISOLATED SHOWERS THROUGH THE NIGHT ACROSS THE SOUTHERN HALF OF KENTUCKY. THIS BOUNDARY WILL LINGER AROUND INTO WEDNESDAY AND WITH INSTABILITY AGAIN RAMPING UP DURING THE AFTERNOON...WE COULD BE LOOKING AT A FEW MORE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. HOWEVER...BY WEDNESDAY...VERY LITTLE SHEAR IS PRESENT...SO WE SHOULD SEE MORE ORDINARY THUNDERSTORMS WITH NO SEVERE THREAT. TEMPERATURES OVER THE NEXT 2 DAYS SHOULD BE FAIRLY SIMILAR TO WHAT WE HAVE SEEN LATELY WITH HIGHS INTO THE LOW TO MID 80S. SAME CAN BE SAID FOR LOWS TONIGHT WITH READINGS GENERALLY AROUND 70. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 330 AM EDT TUE SEP 2 2014 LONG TERM DISCUSSION WILL FOLLOW SHORTLY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 207 AM EDT TUE SEP 2 2014 MAINLY VFR CONDITIONS ARE EXPECTED AT THE TAF SITES OVER THE NEXT 24 TO 36 HOURS. A WEAK COLD FRONT WILL DROP SOUTH INTO EASTERN KENTUCKY TODAY AND COULD SPAWN SCATTERED TO NUMEROUS THUNDERSTORMS. PLAN TO STICK WITH THE VCTS THIS AFTERNOON AS TIMING AND UNCERTAINTY ARE TOO GREAT TO GO WITH A THUNDERSTORM PREVAILING GROUP. ACTIVITY SHOULD WANE BY MID TO LATE EVENING WITH A QUIET NIGHT EXPECTED TONIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KAS LONG TERM...HAL AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
207 AM EDT TUE SEP 2 2014 .UPDATE... ISSUED AT 207 AM EDT TUE SEP 2 2014 UPDATED TO REMOVE POPS FOR MOST AREAS THROUGH THE REMAINDER OF THE NIGHT. THE MCS TO OUR WEST WILL APPROACH THE BLUEGRASS TOWARDS 8 AM...BUT MOST AREAS SHOULD STAY DRY UNTIL THEN. THIS MCS IS EXPECTED TO DECAY THROUGH THE MORNING HOURS AND REALLY NOT MAKE IT VERY FAR INTO EASTERN KENTUCKY IF IT MAKES IT AT ALL. MAY NEED TO WATCH FOR REDEVELOPMENT ALONG THE OUTFLOW FROM THIS SYSTEM LATER ON TOWARDS MIDDAY OR THE AFTERNOON. NO OTHER CHANGES PLANNED AT THIS TIME. UPDATE ISSUED AT 1045 PM EDT MON SEP 1 2014 ISOLATED SHOWERS CONTINUE TO AFFECT NORTHERN KY...INCLUDING THE NORTHERN PART OF THE JACKSON FORECAST AREA. THE SHOWERS HAVE SHOWN A DECREASING TREND...AND THE TOTAL LIGHTNING DATA INDICATES THERE IS NO LONGER ANY LIGHTNING IN KY. CONVECTION CONTINUES TO DEVELOP ACROSS MO AND CENTRAL IL. BASED ON CURRENT TRENDS AND THE LATEST HRRR DATA THIS COULD IMPACT OUR AREA BEGINNING SOMETIME NEAR OF AFTER 12Z. HOURLY NDFD DATA HAS BEEN UPDATED FOR LATEST OBSERVATIONAL TRENDS. UPDATE ISSUED AT 751 PM EDT MON SEP 1 2014 ISOLATED THUNDERSTORMS CONTINUE TO AFFECT THE NORTHERN THIRD OF KY...INCLUDING THE NORTHERN PART OF THE JACKSON FORECAST AREA. WITH LOSS OF DAYTIME HEATING EXPECT THE ISOLATED CONVECTION TO CONTINUE TO WANE. HOWEVER A SHORT WAVE MOVING INTO MO IS RESULTING IN AN INCREASE IN SHOWERS AND THUNDERSTORMS AHEAD OF THE SURFACE COLD FRONT THERE...AND THE REMNANTS OF THIS CONVECTION MAY AFFECT THE NORTHERN PARTS OF THE FORECAST AREA LATE TONIGHT OR EARLY TUESDAY MORNING. THIS IDEA IS SUPPORTED BY THE LATEST HRRR AND THE 18Z NAM AND GFS. HAVE UPDATED NDFD FOR LATEST OBSERVATIONAL TRENDS AND WILL BE MAKING ADDITIONAL ADJUSTMENTS TO HOURLY WEATHER GRIDS SHORTLY. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 315 PM EDT MON SEP 1 2014 A LINE OF SCATTERED SHOWERS AND THUNDERSTORMS CONTINUES TO MOVE ACROSS EASTERN KENTUCKY. THIS LINE IS OUT AHEAD OF THE COLD FRONT IN THE WARM AIR. THERE IS A BIT OF CURVATURE TO THE LINE OF HEAVIEST STORMS;...SO WILL BE WATCHING FOR SOME POTENTIALLY STRONG WIND GUSTS AS THE LINE GOES THROUGH. THE MERCER AND LINCOLN COUNTY MESONET SITES SAW WIND GUSTS OF 30 MPH AS THE LINE WENT THROUGH AND BATH COUNTY SAW A GUST TO 41 MPH. CURRENT THINKING IS THE MAX GUSTS STAY AROUND 40 MPH WITH THE STRONGEST STORMS AND MOST GUSTS WILL BE IN THE 25 TO 35 MPH RANGE AS THE STORMS CONTINUE TO MOVE ACROSS EASTERN KENTUCKY. THESE STORMS WILL DROP BETWEEN 0.25 TO 0.75 INCHES OF RAIN AS IT MOVES ACROSS THE AREA. HAVE A LITTLE CONCERN FOR PARTS OF EASTERN KENTUCKY THAT GOT HAMMERED LAST NIGHT FROM THE HEAVY RAIN...HOWEVER THESE STORMS HAVE BEEN QUITE PROGRESSIVE AND HAVE NOT YET SEEN ANY TRAINING OF THE ECHOES. THIS LINE SHOULD CONTINUE TO MOVE ACROSS THE AREA AND THEN THE LEADING EDGE OF THE PREFRONTAL PRECIPITATION WILL BE MOVING INTO THE AREA LATER TONIGHT. THE FRONT WILL BE MOVING ACROSS THE AREA TOMORROW AND BRING WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE AREA. THERE WILL BE A SLIGHT RISK OF SEVERE THUNDERSTORMS TOMORROW. SPC CURRENTLY HAS MOST OF EASTERN KENTUCKY IN THE SLIGHT RISK AREA. THE MAIN THREAT WILL BE WINDS WITH A VERY WEAK THREAT FOR MARGINALLY SEVERE HAIL. MOST LIKELY...ANY HAIL WILL STAY IN THE 0.5 TO 0.75 INCH RANGE. THE PRECIPITATION WILL DROP OFF FAIRLY QUICKLY BEHIND THE FRONT. THE MODELS ARE IN VERY GOOD AGREEMENT WITH THE TIMING. WENT WITH THE MODEL BLEND FOR THE TEMPERATURES WITH JUST SOME ADJUSTMENTS DUE TO ELEVATION. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 315 PM EDT MON SEP 1 2014 THE MODELS BEGIN THE EXTENDED PERIOD IN PRETTY GOOD AGREEMENT ONCE AGAIN...WITH A RIDGE OF HIGH PRESSURE...BOTH ALOFT AND AT THE SURFACE...CENTERED OVER THE EASTERN GULF OF MEXICO...ALONG WITH A WELL DEFINED TROUGH OF LOW PRESSURE ALOFT TAKING SHAPE OVER THE NORTHERN PLAINS. THE MODELS HAVE THE RIDGE BREAKING DOWN CONSISTENTLY TO BEGIN THE PERIOD...WITH SHOWERS AND STORMS POPPING UP BENEATH IT ACROSS THE TENNESSEE VALLEY DOWN TO THE GULF. AS THE TROUGH EVOLVES AND STRENGTHENS...IT WILL EJECT OUT OF THE PLAINS WEDNESDAY NIGHT AND THURSDAY...AND PUSH ACROSS THE GREAT LAKES AND OHIO VALLEY REGIONS. THE COLD FRONT TRAILING FROM THIS UPPER LOW WILL END BEING OUR WEATHER MAKER FOR THE UPCOMING WEEKEND. THE FRONT IS EXPECTED TO INTERACT WITH MOISTURE COMING OFF THE GULF OF MEXICO ON SOUTHWESTERLY WINDS. THE FRONT WILL HAVE A DIFFICULT TIME MOVING EASTWARD...HOWEVER...AS THE RIDGE DIGS IN A BIT JUST OFF THE SOUTHEAST COAST AND FLOW ALOFT BECOMES MORE ZONAL. THERE WILL BE A GOOD CHANCE OF RAIN FRIDAY MORNING THROUGH SUNDAY MORNING...AS LIFT AND MOISTURE ALONG THE SLUGGISH FRONT SET OFF REPEATED ROUNDS OF SHOWERS AND STORMS. THE RAIN SHOULD FINALLY MOVE OUT OF THE AREA SUNDAY EVENING...AS THE FRONT FINALLY MOVES OUT OF THE AREA. TEMPERATURES TO BEGIN THE PERIOD LOOK TO BE ABOVE NORMAL...WITH HIGHS TOPPING OUT AROUND IN THE MID TO UPPER 80S WEDNESDAY THROUGH FRIDAY. ONCE THE FRONT STALLS ACROSS THE AREA AND PRECIPITATION BECOMES MORE WIDESPREAD...TEMPERATURES WILL LIKELY MAX OUT BELOW NORMAL VALUES SATURDAY THROUGH MONDAY. HIGHS ON FRIDAY WILL BE CLOSER TO NORMAL AS THE FRONT WILL STILL BE TO OUR WEST. ON SATURDAY AND SUNDAY...THE POSITIONING OF THE FRONT WILL ALLOW FOR SOME COOLER AND DRIER AIR TO FILTER INTO THE AREA. HIGHS ON SATURDAY SHOULD BE CLOSE TO NORMAL...AS THE BULK OF COOL AIR SHOULD STILL BE TRAPPED NORTH OF THE OHIO RIVER. ON SUNDAY...HOWEVER...ONCE WINDS HAVE SHIFTED TO THE NORTH...TEMPERATURES WILL BE QUITE COOL...WITH READINGS PEAKING IN THE MID TO UPPER 70S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 207 AM EDT TUE SEP 2 2014 MAINLY VFR CONDITIONS ARE EXPECTED AT THE TAF SITES OVER THE NEXT 24 TO 36 HOURS. A WEAK COLD FRONT WILL DROP SOUTH INTO EASTERN KENTUCKY TODAY AND COULD SPAWN SCATTERED TO NUMEROUS THUNDERSTORMS. PLAN TO STICK WITH THE VCTS THIS AFTERNOON AS TIMING AND UNCERTAINTY ARE TOO GREAT TO GO WITH A THUNDERSTORM PREVAILING GROUP. ACTIVITY SHOULD WANE BY MID TO LATE EVENING WITH A QUIET NIGHT EXPECTED TONIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...JJ LONG TERM...AR AVIATION...KAS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
502 AM EDT TUE SEP 2 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 500 AM EDT TUE SEP 2 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD LOW AMPLITUDE MID/UPPER LEVEL TROUGH THROUGH FROM THE NRN PLAINS INTO THE UPPER MS VALLEY AND WRN GREAT LAKES WITH SEVERAL WEAK EMBEDDED SHORTWAVES. ONE WAS LOCATED FROM SW MN INTO NW IA WHILE ANOTHER UPSTREAM SHRTWV WAS MOVING THROUGH NORTH DAKOTA. AT THE SFC...WRLY FLOW PREVAILED ACROSS UPPER MI BETWEEN A 987 MB LOW NEAR JAMES BAY AND A WEAK RIDGE INTO THE CNTRL PLAINS.IR LOOP SHOWED MAINLY CLEAR SKIES ACROSS MOST OF THE CWA BUT WITH INCREASING CLOUDS FROM MN INTO NW WI AND WRN UPPER MI AHEAD OF THE SW MN SHRTWV. TODAY...MOST OF THE FORCING ASSOCIATED WITH THE MN SHRTWV IS EXPECTED TO REMAIN SOUTH OF UPPER MI. HOWEVER...THE COMBINATION OF DAYTIME HEATING AND 850-600 MB LAPSE RATES TO NEAR 7.5C/KM AND LOW LEVEL CONV ALONG LAKE BREEZE BOUNDARIES(ESPECIALLY OVER THE EAST) WILL SUPPORT ISOLD/SCT SHRA BY THIS AFTERNOON. AS THE NORTH DAKOTA SHRTWV NEAR BY MID TO LATE AFTERNOON SOME ADDITIONAL WEAK QVECTOR CONV MAY ALSO CONTRIBUTE TO PCPN CHANCES. ALTHOUGH MLCAPE VALUES INTO THE 400-800 J/KG RANGE WILL BE MARGINAL FOR TS...SOME ISOLD COULD DEVELOP. WITH FREEZING HEIGHTS ONLY NEAR 9K-10K FT...SOME SMALL HAIL MAY BE POSSIBLE. TONIGHT...WITH THE LOSS OF DAYTIME HEATING AND THE SHRTWVS EXITING TO THE EAST...ANY PCPN SHOULD QUICKLY DIMINISH. WITH THE FAST MID/UPPER LEVEL FLOW ACROSS THE NRN CONUS...MODELS SUGGEST THAT ANOTHER WEAK SHRTWV COULD MOVE THROUGH THE NRN LAKES AND PRODUCE SOME LIGHT PCPN. HOWEVER...WITH VERY LIMITED MOISTURE AND LITTLE INSTABILITY...CONFIDENCE IN ADDITIONAL PCPN DEVELOPING WAS LOW AND NO ADDITIONAL RAIN WAS MENTIONED. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 401 AM EDT TUE SEP 2 2014 THOUGH ACTIVE WEDNESDAY NIGHT INTO THURSDAY EVENING...THE REST OF LONG TERM WILL BE QUIET AS HIGH PRESSURE DOMINATES FROM FRIDAY INTO EARLY NEXT WEEK. STARTING ON WEDNESDAY...WEAKER SHORTWAVES WORK THEIR WAY ACROSS NORTHERN PLAINS AND TO UPPER GREAT LAKES BY LATE IN THE DAY IN A ZONAL FLOW PATTERN ALOFT. LARGE SCALE LIFT IS PRESENT BUT THERE IS NOT MUCH FOR A STRONGER SHORTWAVE AND ALSO OVERALL MOISTURE IS LIMITED. BULK OF SHRA/TSRA LATER ON WEDNESDAY SHOULD STAY WEST OF UPR MICHIGAN...MAINLY OVER CENTRAL AND SOUTHERN MINNESOTA CLOSER TO SFC WARM FRONT AND BUILDING INSTABILITY. COULD SEE ISOLD SHRA/TSRA OVER WESTERN LK SUPERIOR OR EVEN FAR WEST UPR MICHIGAN DUE TO GENERAL H85-H7 WARM AIR ADVECTION AND MID-LEVEL MOISTURE ADVECTION. TEMPS ON WEDNESDAY SHOULD PUSH INTO THE UPPER 70S OR LOWER 80S EVEN WITH SCT-BKN MID CLOUDS IN THE AFTN. POTENTIAL FOR PERIOD OF ACTIVE WEATHER WEDNESDAY NIGHT INTO THURSDAY MORNING AS THE APPROACH OF A SFC LOW OVER THE NORTHERN PLAINS INCREASES LOW-LEVEL JET /40 KTS AT H85/ INTO THE UPPER GREAT LAKES. SINCE THERE IS NOT REALLY A STRONG SHORTWAVE MOVING THROUGH AT THAT TIME THOUGH...THINK THAT THE BULK OF SHRA/TSRA WILL BE VCNTY OF WHERE LOW- LEVEL JET INTERSECTS THE SFC-H85 WARM FRONT. BASED ON SFC WINDS AND DWPNTS...BEST GUESS AT LOCATION OF THAT BOUNDARY IS FM CNTRL MN INTO WESTERN WI WEDNESDAY NIGHT. MAX INSTABILITY BOTH IN TERMS OF MLCAPE AND ELEVATED MUCAPE WILL BE MAXIMIZED OVER MUCH OF MINNESOTA AND INTO WISCONSIN WITH INSTABILITY TRAILING OFF CONSIDERABLY INTO UPR MICHIGAN AND LK MICHIGAN/LOWER MICHIGAN. MAJORITY OF MODELS INDICATE WIDESPREAD QPF OVER UPR MICHIGAN WEDNESDAY NIGHT...BUT HAVE MY DOUBTS ON THIS AS MOST OF THE HEAVY SHRA/TSRA COULD END UP FARTHER SOUTH ALONG WARM FRONT AND ALSO BASED ON H85-H3 THICKNESSES WHICH...ALONG WITH FORWARD PROPAGATING CORFIDI VECTORS...CAN BE USED TO DETERMINE GENERAL MOTION OF AN MCS. SIMILAR TO EARLIER IN THE NIGHT...THERE IS STILL MID-LEVEL MOISTURE ADVECTION FARTHER NORTH OF THE BOUNDARY THOUGH SO CANNOT COMPLETELY RULE OUT SHRA/TSRA MAKING IT ACROSS UPR MICHIGAN. ANOTHER FACTOR THAT COULD BUMP SHRA/TSRA FARTHER NORTH INTO THE CWA IS INCREASING CAPPING THAT DEVELOPS IN THE H8-H7 LAYER OUT AHEAD OF THE SFC LOW. AT THIS POINT THOUGH IT APPEARS THAT MAIN EXTENT OF CAPPING WILL REMAIN BACK OVER THE CENTRAL PLAINS ON WEDNESDAY NIGHT. GIVEN THE CONCERNS ABOUT TSRA OVERAGE...BACKED DOWN A BIT ON THE HIGHER POPS WE HAD GOING BUT DID KEEP POPS HIGH CHANCE TO LOW END LIKELY WITH BETTER CHANCES OVER THE WEST INITIALLY SHIFTING TO THE EAST FOLLOWING THE TREND OF H7-H5 Q-VECTOR CONVERGENCE TIED TO INITIAL WEAK SHORTWAVE AND ALSO WHERE THIS FORCING SYNCS UP WITH GREATER MID-LEVEL MOISTURE TRANSPORT. TSRA INTENSITY SHOULD DIMINISH INTO THE EAST BY LATE WED NIGHT INTO THURSDAY MORNING AS SHRA/TSRA OUTRUN GREATER POOL OF INSTABILITY OVER MINNESOTA AND WISCONSIN. FOR THURSDAY...RETAINED MUCH OF THE PREVIOUS FORECAST SHOWING TREND TOWARD LOWER POPS BY LATE THURSDAY MORNING IN WAKE OF THE INITIAL SHRA/TSRA MOVING EAST THEN POPS RAMPING BACK UP IN THE AFTN WITH POSSIBLE ADDITIONAL SHRA/TSRA AHEAD OF APPROACHING COLD FRONT. CAPPING SHOULD INCREASE MARKEDLY BY LATE MORNING/EARLY AFTN BASED ON FORECAST SOUNDINGS SO THIS WILL IMPACT ADDITIONAL DEVELOPMENT OF SHRA/TSRA. COULD GET QUITE WARM WITH EVEN JUST A LITTLE CLEARING. MIXING TO H9 WITH SHARPER INVERSION AROUND THAT LEVEL SHOWN ON SOUNDINGS MAY BE CONSERVATIVE BUT STILL RESULTS IN HIGHS AROUND 80 OVER MUCH OF CWA. NUDGED TEMPS UP INTO THE LOWER 80S AS A STARTING POINT...BUT A MUGGY DAY /SFC DWPNTS 65-70/ WITH MID 80S IS CERTAINLY POSSIBLE IN SOME AREAS. PRIMARY SHORTWAVE DRIVING THE COLD FRONT WILL BE JUST NORTH OF MINNESOTA BY LATE THURSDAY AFTN. GIVEN THE WARM AND HUMID AIRMASS...MLCAPES AHEAD OF THE FRONT OVER WEST HALF OF CWA COULD PUSH OVER 2500J/KG...BUT MAIN QUESTIONS ARE HOW MUCH DEEPER MOISTURE WILL BE AROUND AHEAD OF THE FRONT AND WILL CAPPING IN THE H8-H7 LAYER BE TOO STRONG TO PROHIBIT SHRA/TSRA FROM DEVELOPING? BASED ON CONSENSUS OF MODELS AND LATEST TRENDS...SEEMS THAT THERE IS A RISK OF STORMS FORMING MID-LATE THURSDAY AFTN OVER THE WEST AND AFFECTING REST OF CWA INTO THE EARLY EVENING AS BETTER MOISTURE IS RE-INTRODUCED INTO THE AREA FM THE WEST/SOUTHWEST AND LIFT INCREASES AND CAPPING DECREASES AS SHORTWAVE AND H5 SPEED MAX DRAW CLOSER. GIVEN THE DEGREE OF INSTABILITY...IF STORMS FORM...SEVERE WEATHER POTENTIAL IS ELEVATED AS 0-6KM SHEAR IS OVER 45 KTS AND 0-3KM SHEAR IS OVER 30 KTS. THE FORECASTED INSTABILITY...IF IT IS INDEED REALIZED...AND SUCH SHEAR WOULD SUPPORT ROTATING/SUPERCELL TYPE STORMS AND ALSO POTENTIAL FOR STORMS CONSOLIDATING INTO SEVERE WIND GUST PRODUCING MCS ALONG THE COLD FRONT. A CONDITIONAL RISK ATTM...BUT CERTAINTLY WORTH MONITORING AS WE GET CLOSER TO THIS TIME FRAME. SPC DAY3 OUTLOOK HIGHLIGHTS WI INTO WEST HALF OF UPR MICHIGAN WITH A 15 PCT RISK FOR SEVERE /SLIGHT CATEGORICAL RISK/. WILL MENTION POTENTIAL FOR SEVERE IN THE MORNING HAZARDOUS WEATHER OUTLOOK. ONCE THE COLD FRONT SLIDES THROUGH ON THURSDAY NIGHT...ANY LINGERING SHRA/TSRA WILL QUICKLY COME TO AN END BY THE OVERNIGHT SOUTH AND EAST CWA. MAIN ISSUE LATE THURSDAY NIGHT INTO FRIDAY WILL BE GUSTY NORTHWEST WINDS ON LK SUPERIOR AS IT BECOMES UNSTABLE IN THE 1000-900MB LAYER. MIXED LAYER WINDS ARE OVER 30 KTS SO IT COULD BE GUSTY ALONG THE LK SUPERIOR SHORE TO BEGIN THE DAY ON FRIDAY. DUE TO PRESSURE RISES BTWN DEPARTING LOW AND APPROACHING HIGH...EVEN HIGHER WINDS WOULD NOT BE OUT OF QUESTION. INCREASING WAVE ACTION WOULD ALSO LEAD TO HIGH SWIM RISK ON BEACHES FROM MARQUETTE TO GRAND MARAIS. QUIET WEATHER FOR THE WEEKEND AS IT LOOKS NOW. HIGH PRESSURE SETTLES OVERHEAD AND STAYS IN PLACE INTO EARLY NEXT WEEK. TEMPS AT NIGHT MAY DIP BLO 40 DEGREES IN THE INTERIOR. DAYTIME HIGHS WILL BE SEASONABLY COOL IN THE 60S FOR MOST AREAS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 122 AM EDT TUE SEP 2 2014 EXPECT VFR CONDITIONS TO PREDOMINATE THIS FCST PERIOD WITH RELATIVELY DRY LLVL AIR SHOWN ON UPSTREAM RAOBS DOMINATING. AN APRCHG UPR DISTURBANCE/DAYTIME HEATING AND DESTABILIZATION COULD CAUSE SOME -SHRA AT SAW AND PERHAPS IWD THIS AFTN...BUT THE DRY LLVL AIR SHOULD MAINTAIN PREDOMINANT VFR WX EVEN IF THE -SHRA OCCUR. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 500 AM EDT TUE SEP 2 2014 WINDS WILL BE 20 KNOTS OR LESS THROUGH MOST OF THIS FORECAST PERIOD EXCEPT FOR THU NIGHT INTO FRI WHEN WEST TO NORTHWEST WINDS BEHIND A STRONG COLD FRONT WILL APPROACH 30 KNOTS. THIS WILL BE THE WHEN THE STRONGEST WINDS OCCUR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...KC MARINE...JLB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1225 AM CDT TUE SEP 2 2014 .UPDATE... ISSUED AT 1225 AM CDT TUE SEP 2 2014 ONLY MINOR TWEAKS WERE MADE TO THE ONGOING FORECAST. CANADIAN RADAR SHOWS SCATTERED SHOWERS MOVING SOUTHEAST ACROSS THE CANADIAN PRAIRIES. THE LATEST RUN OF THE HRRR (03 UTC) PICKS UP ON THE CANADIAN ACTIVITY AND BRINGS A FEW ISOLATED SHOWERS ACROSS THE NORTH THROUGH THE EARLY MORNING HOURS. UPDATED THE PRECIP FORECAST TO REFLECT THE LATEST TRENDS. LATEST TEMPERATURE OBSERVATIONS WERE NEARING OVERNIGHT FORECAST LOWS ALREADY. WITH SEVERAL HOURS OF DIURNAL COOLING AHEAD...LOWERED THE OVERNIGHT LOWS A FEW MORE DEGREES. UPDATE ISSUED AT 938 PM CDT MON SEP 1 2014 SCATTERED/ISOLATED SHOWERS AND THUNDERSTORMS HAVE DIMINISHED OVER THE LAST HOUR WITH THE LOSS OF DAYTIME HEATING. REMOVED EVENING POPS FROM THE FORECAST AS A RESULT. ALSO ADJUSTED THE HOURLY TEMP/DEWPOINT GRIDS BASED ON CURRENT OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 604 PM CDT MON SEP 1 2014 ISOLATED TO SCATTERED INSTABILITY SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP THROUGH THE EARLY EVENING HOURS...MAINLY OVER WESTERN NORTH DAKOTA. WITH VERY WEAK DEEP LAYER SHEAR IN PLACE...THIS CONVECTION IS EXPECTED TO BE BRIEF AND SUB-SEVERE. IT SHOULD END BY 03Z THIS EVENING...IF NOT SOONER. AFTER MIDNIGHT...THE MESOSCALE MODELS PROG A WEAK WAVE AND ATTENDANT LIGHT QPF TO SKIRT ACROSS THE CANADIAN BORDER COUNTIES. AS A RESULT...WILL MAINTAIN SLIGHT CHANCE POPS ACROSS THE EXTREME NORTHERN CWA AFTER MIDNIGHT. CONVECTION SHOULD BE BRIEF AND REMAIN SUB-SEVERE IF IT EVEN MATERIALIZES. OTHERWISE...JUST MADE A FEW COSMETIC ADJUSTMENTS TO THE HOURLY SENSIBLE WEATHER GRIDS. THE UPDATED PRODUCTS WILL BE OUT SHORTLY. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 247 PM CDT MON SEP 1 2014 CURRENT SURFACE ANALYSIS PLACES LOW OVER ONTARIO WITH HIGH OVER THE PACIFIC NORTHWEST INTO THE CENTRAL ROCKIES. UPPER LEVEL ANALYSIS PLACES BROAD TROUGH CENTERED OVER THE PLAINS WORKING TOWARDS THE MIDWEST. MODEST SHORT WAVE WORKING THROUGH THE FLOW NOW MAKING ITS WAY FROM EASTERN MONTANA INTO THE WESTERN DAKOTAS STARTING TO PRODUCE SOME CONVECTION. FOR THE REST OF THIS AFTERNOON INTO THIS EVENING...EXPECT SOME SHOWERS AND THUNDERSTORMS TO CONTINUE TO DEVELOP THROUGH THE AFTERNOON. EXPECT ANY ACTIVITY SHOULD REMAIN ON THE TAME SIDE WITH WEAK INSTABILITY/SHEAR. MOST ACTIVITY SHOULD COME TO AN END THIS EVENING WITH DIMINISHING INSOLATION...THOUGH SOME SHOWERS/STORMS MAY LINGER THROUGH THE OVERNIGHT OVER FAR NORTHERN NORTH DAKOTA AS ANOTHER WAVE MAKES ITS WAY THROUGH. ON TUESDAY...A FEW SHOWERS/STORMS MAY CONTINUE OVER THE FAR NORTH AS AFOREMENTIONED WAVE CONTINUES TO MAKE ITS WAY THROUGH. OTHERWISE A QUIET DAY IS ON TAP AS LOW AMPLITUDE RIDGE STARTS TO WORK ITS WAY INTO THE AREA. SLIGHTLY MILDER TEMPS ARE EXPECTED. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 247 PM CDT MON SEP 1 2014 THE EXTENDED MODEL SUITE IS IN GOOD AGREEMENT WITH A POSITIVELY TILTED SHORTWAVE TROUGH CURRENTLY LOCATED/ELONGATED FROM 140W/60N TO 150W/55N...TO SHIFT INLAND TUESDAY NIGHT. THIS TROUGH IS FORECAST TO REMAIN NEUTRAL TO SLIGHTLY NEGATIVE TILTED AS IT SLIDES ACROSS WESTERN AND CENTRAL NORTH DAKOTA WEDNESDAY NIGHT/THURSDAY MORNING. THIS WILL BE THE TIME PERIOD WITH THE HIGHEST POPS...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. HEAVIEST RAINFALL APPEARS TO OCCUR OVER NORTH CENTRAL NORTH DAKOTA WITH AROUND 0.65 INCHES FORECAST FROM MOHALL TO STANLEY...AND FROM MINOT TO NEAR GARRISON. NAM/GFS SOUNDINGS SHOW A STRONG CAP IN PLACE THROUGH 00Z THURSDAY FOR KMOT/KBIS/KJMS...AND A WEAKER CAP IN PLACE AT KISN/KDIK. HAVE CONFINED POPS TO MAINLY THE NORTHWEST AND PORTIONS OF NORTH CENTRAL NORTH DAKOTA WEDNESDAY...WITH SHOWERS AND THUNDERSTORMS INCREASING IN COVERAGE WEDNESDAY EVENING AND NIGHT. A POTENT COLD FRONT SWEEPS THROUGH WEDNESDAY NIGHT WITH THE UPPER TROUGH APPROACHING AND SLIDING THROUGH ON THURSDAY. SPC HAS A SEE TEXT WHICH INCLUDES NORTH DAKOTA...HOWEVER LIMITED LOW LEVEL MOISTURE PER AN EAST TO SOUTHEASTERLY FLOW MAY INHIBIT ORGANIZED SEVERE THUNDERSTORMS FROM DEVELOPING. HOWEVER STRONG 0-6KM SHEAR OF 55KT TO 60KT WILL BE IN PLACE AHEAD OF THE UPPER TROUGH AND ALONG/AHEAD OF THE SURFACE COLD FRONT. THIS WILL BE MONITORED CLOSELY. STRONG COOLING AS THE H85 FRONT SLIDES THROUGH...WITH TEMPS COOLING FROM AROUND +20C WEDNESDAY EVENING...TO +6C THURSDAY EVENING. EXPECT THE GREATEST WARMTH TO OCCUR ACROSS SOUTHERN NORTH DAKOTA WEDNESDAY AFTERNOON ALONG/AHEAD OF THE H85 THERMAL RIDGE AXIS. EXPECT HIGHS IN THE LOWER 80S. THIS WILL BE REPLACED WITH WIDESPREAD HIGHS IN THE 60S...EXCEPT LOWER 70S IN THE FAR SOUTHERN JAMES RIVER VALLEY THURSDAY. BREEZY NORTHWEST WINDS OF 15 TO 25 MPH WILL ALSO MATERIALIZE BEHIND THE FRONT FOR THURSDAY. WITH THE UPPER TROUGH SWINGING THROUGH THURSDAY...STILL EXPECT A CHANCE FOR SHOWERS AND THUNDERSHOWERS MAINLY ACROSS THE NORTH. THEREAFTER...FRIDAY THROUGH SUNDAY...DRY WEATHER WITH A SLOW MODERATING TREND AS BROAD CYCLONIC NORTHWEST FLOW DOMINATES THROUGH SATURDAY. THIS TRANSITIONS TO BROAD RIDGING SUNDAY AND HIGHS WARMING INTO THE MID 70S. A SLIGHT CHANCE OF THUNDERSTORMS COULD RETURN BY MONDAY BUT THE BETTER CHANCES ARRIVE TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1225 AM CDT TUE SEP 2 2014 VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH THE TAF PERIOD WITH PREDOMINATELY WEST SOUTHWEST WINDS AND SCATTERED HIGH CLOUDS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AJ SHORT TERM...JJS LONG TERM...KS AVIATION...AJ
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
408 AM EDT TUE SEP 2 2014 .SYNOPSIS... A WEAK COLD FRONT WILL MOVE ACROSS THE AREA TODAY EXTENDING FROM LOW PRESSURE TRACKING NORTHEAST ACROSS QUEBEC. HIGH PRESSURE WILL EXPAND OVER THE OHIO VALLEY TONIGHT...THEN TO THE EAST COAST ON WEDNESDAY. A WARM FRONT WILL LIFT NORTH ON THURSDAY AHEAD OF THE NEXT LOW PRESSURE SYSTEM THAT WILL PASS NORTH OF THE GREAT LAKES ON FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A SWATH OF RAIN CAN BE SEEN ON UPSTREAM RADARS SPREADING NORTHEAST ACROSS INDIANA EARLY THIS MORNING. THIS RAIN WILL CONTINUE TO BE PULLED NORTHEAST AHEAD OF THE SHORTWAVE ENERGY MOVING ACROSS THE PLAINS. THE 00Z SOUNDING OUT OF ILX SHOWED QUITE A BIT OF DRY AIR IN THE COLUMN AHEAD OF THIS DEEPER PUSH OF MOISTURE AND THIS NOW RESIDES OVER THE FORECAST AREA EARLY THIS MORNING. THE STRONGER MOISTURE ADVECTION IS FOCUSED NEAR 700MB AND THE DRIER LOW LEVEL AIR MAY CAUSE SOME EVAPORATION INITIALLY. THE BETTER INSTABILITY WILL BE LOCATED FARTHER SOUTH AND TRENDS HAVE BEEN FOR THE DEEP CONVECTION TO RESIDE ON THE SE FLANK OF THE PRECIPITATION SHIELD. WILL CARRY A HIGH POP FOR JUST ABOUT ALL AREAS THIS MORNING...ALTHOUGH WILL ONLY CARRY A CHANCE OF THUNDERSTORMS(BETTER CHANCES OF THUNDERSTORMS WILL BE LOCATED ALONG AND SOUTH OF INTERSTATE 70 IN CENTRAL OHIO). PRECIPITATION AMOUNTS WILL GENERALLY BE A HALF INCH OR LESS. LOW PRESSURE IS LOCATED JUST EAST OF JAMES BAY THIS MORNING WITH THE TRAILING COLD FRONT STILL LOCATED NORTH OF LAKE ERIE. THIS WEAK FRONT IS EXPECTED TO MOVE THROUGH TOLEDO AROUND NOON...CLEVELAND EARLY THIS AFTERNOON AND YOUNGSTOWN BY LATE AFTERNOON. ALTHOUGH THE INITIAL SURGE OF MOISTURE WILL EXIT TO THE EAST...THE FRONT WILL INTERACT WITH THE LINGERING MOISTURE WITH A CHANCE OF SHOWERS AND THUNDERSTORMS IN THE EASTERN AREAS THIS AFTERNOON. THE STORM PREDICTION CENTER HAS PLACED OUR SE TIER OF COUNTIES IN THE SLIGHT RISK FOR SEVERE THUNDERSTORMS TODAY. EXPECTING A CONSIDERABLE AMOUNT OF CLOUD COVER TO HAVE A LIMITING EFFECT ON HEATING/INSTABILITY ALONG AND AHEAD OF THE FRONT THIS AFTERNOON. BETTER CHANCES OF SEVERE WEATHER WILL BE LOCATED JUST SOUTH AND EAST OF THE AREA BUT CAN NOT ENTIRELY RULE OUT A SEVERE STORM IF HEATING IS STRONGER THAN EXPECTED. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... HIGH PRESSURE WILL EXPAND EASTWARD ACROSS THE OHIO VALLEY TONIGHT. IT LOOKS LIKE A WEAK THERMAL TROUGH WILL LINGER OVER LAKE ERIE ON THE NORTH SIDE OF THE HIGH THIS EVENING AND MAY PROVIDE ENOUGH CONVERGENCE FOR A FEW SHOWERS TO DEVELOP OVER THE LAKE. LEFT A LOW POP BOTH OVER THE LAKE AND ALONG THE EASTERN LAKESHORE FOR A PORTION OF THE NIGHT. INLAND AREAS...ESPECIALLY OUR SOUTHERN COUNTIES COULD SEE SOME FOG OR STRATUS GIVEN THE LINGERING BOUNDARY LAYER MOISTURE COUPLED WITH CLEARING SKIES AND LIGHT WINDS. TEMPERATURES WILL BOTTOM OUT IN THE UPPER 50S TO LOW 60S. THE AIRMASS DOES NOT COOL MUCH WITH THE FRONTAL PASSAGE AND TEMPERATURES ARE STILL EXPECTED TO BE A COUPLE DEGREES ABOVE NORMAL ON WEDNESDAY. THE MAIN DIFFERENCE WILL BE FELT IN THE HUMIDITY WHICH WILL BE LOWER AND MORE PLEASANT WITH DEWPOINTS NEAR 60 DEGREES. MAINLY JUST SCATTERED CU ON WEDNESDAY ONCE ANY MORNING CLOUDS BURN OFF. HEIGHTS WILL REBOUND OVER THE AREA ON THURSDAY AND A WARM FRONT WILL LIFT NORTH AHEAD OF THE NEXT LOW PRESSURE SYSTEM TRACKING OUT OF THE PLAINS. THIS SYSTEM IS FORECAST TO TRACK ACROSS LAKE SUPERIOR THEN CONTINUE NORTHEAST ACROSS ONTARIO AND QUEBEC. ENOUGH DRY AIR SHOULD STILL BE IN PLACE ON THURSDAY FOR THE FORECAST AREA TO STAY DRY. LEFT THE 20 POP IN THE FORECAST ON THURSDAY NIGHT AS MOISTURE DOES START TO INCREASE ALTHOUGH THE MORE FOCUSED MOISTURE ADVECTION WILL BE WELL TO THE NORTH. THE ASSOCIATED COLD FRONT WILL SINK SOUTH TOWARDS THE AREA ON FRIDAY. LOWERED POPS DURING THE MORNING HOURS AND ACROSS THE SOUTHERN COUNTIES THAT SHOULD STRUGGLE TO SEE ANY PRECIPITATION UNTIL FRIDAY NIGHT. TEMPERATURES ON THURSDAY AND FRIDAY WILL BE IN THE MID 80S...WITH A FEW SPOTS MAKING A RUN AT THE UPPER 80S. && .LONG TERM /SATURDAY THROUGH MONDAY/... NO BIG CHANGES TO THE MODELS FOR THE EXTENDED WITH GUIDANCE SHOWING A COLD FRONT TO OUR SOUTH SATURDAY MORNING WITH DRIER AIR AND HIGH MOVING IN FROM THE NORTH. DONT THINK THE DAY WILL BEGIN DRY HOWEVER AS THE ECMWF REMAINS SLOWER THAN THE GFS IN MOVING MOISTURE OUT OF THE AREA. WILL CONTINUE WITH CHANCE POPS THROUGH THE MORNING SATURDAY BEFORE DROPPING TO A SLIGHT CHANCE ACROSS THE NORTH. SATURDAY NIGHT THROUGH MONDAY LOOK DRY. TEMPS NEAR NORMAL AFTER AN ABOVE NORMAL END TO THE WEEK. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... WEAK COLD FRONT TO OUR NORTHWEST WITH BEST GUESS POSITION FROM CENTRAL LWR MI SW INTO MO. MCS ACROSS MO AND SRN IL WHILE A FEW LINGERING SHOWERS ALONG WITH A LITTLE THUNDER ACROSS FAR EASTERN ERIE COUNTY PA AND EAST INTO WRN NY. THAT ACTIVITY WILL CONTINUE EAST OUT OF THE AREA OVER THE NEXT HOUR OR TWO. HRRR DOES SHOW SOME REDEVELOPMENT OVER ERIE COUNTY AND WILL ACCOUNT FOR THAT IN THE TAF. OTHERWISE MAINLY VFR ACROSS THE AREA THIS HOURS ALTHOUGH THE HRRR DOES SHOW ACTIVITY TO OUR WEST MOVING INTO THE AREA TOWARDS MORNING. EXPECT THE BULK OF THE CONVECTION TO REMAIN SOUTH OF OUR AREA...TRACKING ACROSS CENTRAL AND SRN OHIO...HOWEVER SO EXPECT SOME PRECIP TO EXTEND NORTH AND AFFECT THE AREA. BROUGHT SHOWERS INTO KTOL/KFDY AROUND 10Z AND KCLE/KMFD 11-12Z AND KERI- KYNG 14-15Z. ALSO INCLUDED VCTS BUT FOR NOW DID NOT INCLUDE THUNDER IN TEMPO GROUPS. HELD ONTO MVFR CIGS THROUGH THE BALANCE OF THE MORNING GIVEN DEEP HIGH RH ACROSS THE AREA. DRIER AIR SHOULD BEGIN MOVING IN THROUGH THE AFTERNOON. OUTLOOK...NON VFR LIKELY IN SHOWERS AND THUNDERSTORMS BY FRIDAY EVENING INTO SATURDAY WITH THE NEXT COLD FRONT. && .MARINE... WILL BEGIN TODAY CLOSE TO SMALL CRAFT CRITERIA MAINLY EAST OF CONNEAUT BUT FOR NOW WILL CONTINUE WITH A FORECAST JUST BELOW. WINDS TODAY WILL BE FROM THE SOUTHWEST AHEAD OF A WEAK COLD FRONT DUE IN LATE MORNING/EARLY AFTERNOON. WINDS WILL TURN WEST TO BRIEFLY NORTHWEST BEHIND THE BOUNDARY. HIGH PRESSURE BUILDS IN TONIGHT AND WEDNESDAY. THURSDAY THE HIGH WILL DRIFT EAST AND A LOW WILL BE MOVING THROUGH THE NORTHERN PLAINS. THIS WILL AGAIN SETUP SOUTHWEST FLOW ON THE LAKE THURSDAY INCREASING TO 10 TO 20 KNOTS. THE LOW WILL MOVE THROUGH EASTERN CANADA FRIDAY DRAGGING A COLD FRONT ACROSS THE LAKE DURING THE AFTERNOON. WINDS WILL TURN NORTHWEST FRIDAY NIGHT AND SATURDAY BEHIND THE FRONT. ALTHOUGH CLOSE...NO NEAR TERM HEADLINES FOR NOW. FRIDAY INTO SATURDAY WE COULD REACH SMALL CRAFT CRITERIA AS WINDS TURN NORTHWEST. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KEC NEAR TERM...KEC SHORT TERM...KEC LONG TERM...TK AVIATION...TK MARINE...TK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
152 AM EDT TUE SEP 2 2014 .SYNOPSIS... A COLD FRONT WILL REACH THE NORTHERN OHIO VALLEY BY DAYBREAK AND CROSS THE REGION FROM THE NORTHWEST ON TUESDAY. HIGH PRESSURE WILL BRIEFLY BUILD IN BEHIND THE FRONT...WITH DRY CONDITIONS EXPECTED FOR WEDNESDAY. A RETURN TO SOUTHERLY FLOW WILL INCREASE THE THREAT FOR SHOWERS AND STORMS AT THE END OF THE WEEK...CULMINATING ON SATURDAY AS THE NEXT COLD FRONT CROSSES THE REGION. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... ONLY A FEW SHOWERS LINGERING IN THE FAR EASTERN ZONES AND THEY WILL MOVE OUT BEFORE MIDNIGHT. SHOWERS AND STORMS OCCURRING IN THE CENTRAL PLAINS WILL SPREAD EAST NORTHEAST TOWARDS THE REGION. HRRR AND RAP MODELS SHOWING SOME TIMING DISCREPANCIES. BUT IT APPEARS THAT ACTIVITY WILL NOT SPREAD INTO WESTERN ZONES UNTIL VERY LATE TONIGHT. EXPECT ANY HEAVIER RAINFALL TO CLOSER TO THE END OF THE PERIOD AND INTO TUESDAY. FORECAST LOWS LOOK REASONABLE. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/... BY THE TIME DAYLIGHT HOURS OF TUESDAY ROLLS AROUND...THE SYSTEM IS EXPECTED TO SHIFT THE SW-NE AXIS MORE INTO THE CWA AND ALONG THE I-71 CORRIDOR. AREAS THAT SAW EXCESSIVE RAINFALL ON SATURDAY MAY BE HIT WITH ANOTHER SOAKER...BUT THE UNUSUALLY HIGH VALUES SHOULD NOT MAKE ANOTHER APPEARANCE...AT LEAST OVER WARREN AND GREENE COUNTIES. PRECIP DURING THE DAY OVER THE CWA WILL BE PROGRESSIVE AND EXPAND SOUTHEAST TO COVER THE REST OF CWA BY THE AFTERNOON. HIGH TEMPS WILL BE MUTED DUE TO THE RAINFALL...GENERALLY IN THE LOW 80S...SOME MID 80S ARE POSSIBLE IF THE RAIN HOLDS OFF A FEW HOURS OVER THE SOUTHEAST. HIGH PRESSURE WILL BRIEFLY FILL IN BEHIND THE COLD FRONT AND PROVIDE ENOUGH DOWNWARD MOTION TO HELP SCOUR OUT MOST OF THE CLOUD COVER AND USHER IN SOME DRIER AIR. THE DRIEST AIR AND SUBSEQUENT COOLER TEMPERATURES FOR TUESDAY NIGHT WILL BE FOUND ALONG AND NORTH OF THE I-70 CORRIDOR...WITH THE AREA EAST OF COLUMBUS GETTING THE BEST COOLING BOTH TUES AND WED NIGHTS. NORTH OF DAYTON ON WED NIGHT WILL LIKELY BE INVOLVED WITH THE RETURNING WARMER AND MORE MOIST AIR ON THE SOUTHERLY WINDS. HIGHS ON WEDNESDAY WILL REACH THE LOW TO MID 80S ACROSS THE REGION. && .LONG TERM /THURSDAY THROUGH MONDAY/... PERIOD BEGINS WITH A WEAK WARM FRONT LIFTING UP THROUGH THE WRN OHIO VALLEY. AS FRONT LIFTS UP ACROSS THE AREA THURSDAY...THERE WILL BE A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM. BY FRIDAY...A CDFNT BEGINS TO PUSH THROUGH THE GREAT LAKES. MODELS ARE SHOWING A RANGE ON THE FROPA TIMING. THE GFS IS THE QUICKEST...WHILE THE ECMWF IS ON THE SLOWER END OF THE GUIDANCE. BOTH MODELS SHOW FROPA FRIDAY NIGHT INTO SATURDAY MORNING WITH CONTINUED PCPN CHANCES ON SATURDAY. PUT THE BEST POPS FRIDAY NIGHT WITH 50 POP ACROSS THE REGION. REDEVELOPED THE PCPN SATURDAY MORNING WITH 50 POPS ACROSS THE SOUTH...BUT LOWER POPS TO THE NW. THE GFS DRIES THINGS OUT QUICKER SATURDAY NIGHT AS COMPARED TO THE ECMWF WHICH LEAVES LINGERING PCPN CHANCES INTO SATURDAY NIGHT ACROSS THE SOUTH. HELD ON TO 20 POPS FOR THE EVENING HOURS IN THE SOUTHEAST. HIGH PRESSURE BUILDS ACROSS THE REGION SUNDAY INTO MONDAY. WARM AND HUMID CONDITIONS ARE EXPECTED FOR THURSDAY AND FRIDAY. HIGHS WILL BE IN THE UPPER 80S TO 90 WITH DEWPOINTS IN THE UPPER 60S TO LOWER 70S. COOLER CONDITIONS SATURDAY WITH HIGHS RANGING FROM THE MID 70S IN THE NORTH TO THE LOWER 80S IN NRN KY. BY SUNDAY AND MONDAY...HIGHS WILL BE IN THE LOWER TO MID 70S ACROSS THE REGION. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... SOME SPOTTY MVFR STRATUS IS STARTING TO DEVELOP ACROSS THE AREA AND THIS COULD FILL IN A BIT MORE OVER THE NEXT HOUR OR SO. HOWEVER...THINK THE QUICKLY THICKENING CIRRUS SHIELD SHOULD PREVENT IT FROM BECOMING TOO WIDESPREAD. OTHERWISE...AN AREA OF SHOWERS AND THUNDERSTORMS PROGRESSING EAST ACROSS EASTERN ILLINOIS AND WESTERN INDIANA SHOULD APPROACH THE WESTERN TAF SITES TOWARD 09Z AND THE EASTERN TAF SITES AROUND 11Z. PCPN IS ASSOCIATED WITH A GOOD LOW LEVEL JET THAT IS FORECAST TO SHIFT EAST INTO OUR AREA THROUGH 12Z BEFORE BEGINNING TO WEAKEN BETWEEN 12Z AND 15Z. THIS SHOULD ALLOW FOR AN OVERALL WEAKENING TREND IN THE THUNDERSTORM INTENSITY/COVERAGE THROUGH MID TO LATE MORNING AS IT PROGRESSES EAST ACROSS OUR AREA. AS THIS INITIAL WAVE PUSHES EAST OF THE AREA...WE COULD SEE A LULL IN THE PCPN FROM LATE MORNING INTO EARLY AFTERNOON. HOWEVER...AS WE DESTABILIZE THROUGH THE AFTERNOON...EXPECT TO SEE SOME ISOLATED TO SCATTERED THUNDERSTORM REDEVELOPMENT. DRIER AIR WILL PUSH IN FROM THE NORTHWEST LATE THIS AFTERNOON INTO THIS EVENING...ALLOWING FOR DECREASING CLOUDS THROUGH THE END OF THE TAF PERIOD. OUTLOOK...MVFR TO IFR VISIBILITIES ARE POSSIBLE LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. THUNDERSTORMS POSSIBLE FRIDAY INTO SATURDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...FRANKS NEAR TERM... SHORT TERM...FRANKS LONG TERM...SITES AVIATION...JGL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
122 AM EDT TUE SEP 2 2014 .SYNOPSIS... A COLD FRONT WILL MOVE EAST ACROSS THE AREA ON TUESDAY. HIGH PRESSURE WILL BUILD NORTH OUT OF THE GULF COAST STATES TUESDAY THROUGH THURSDAY AND THEN MOVE TO THE EAST COAST. A WARM FRONT WILL LIFT NORTH ACROSS THE REGION THURSDAY AS LOW PRESSURE MOVES EAST ACROSS THE NORTHERN LAKES THURSDAY NIGHT. A COLD FRONT TRAILING FROM THE LOW WILL SAG SOUTHEAST OVER THE REGION FRIDAY NIGHT. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THE PREFRONTAL TROUGH ARE LOCATED OUT OVER LAKE ERIE AND ARE MOVING WITH AN EAST- NORTHEAST DIRECTION. THEREFORE THEY MAY CLIP ERIE COUNTY PA BEFORE HEADING OFF TO NY. ALL OTHERS WILL BE PRIMARILY DRY ALTHOUGH CANNOT RULE OUT A STRAY SHOWER/TS OVERNIGHT. A COLD FRONT WAS LOCATED FAR TO THE WEST...NEAR CHICAGO. THE BETTER CHANCE OF PRECIPITATION COMES MUCH LATER TONIGHT AS A WAVE DEVELOPS ALONG THIS FRONT WITH SUPPORT OF AN UPPER LEVEL WAVE AND JET MAX. A STEADIER RAIN WITH EMBEDDED THUNDER WILL BEGIN TO WORK ITS WAY IN FROM THE FINDLAY AREA NORTHEAST TOWARD MORNING. THERE IS SOME QUESTION AS TO HOW FAST IT CAN MOVE INTO THE AREA BEFORE 6 AM. AREA WILL STILL BE IN THE WARM SECTOR OVERNIGHT AND EXPECT LOWS ONLY IN THE UPPER 60S AND LOWER 70S. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/... MORNING SHORTWAVE WILL PULL NORTHEAST AND DIMINISH THE RAIN CHANCES AS THE DAY GOES ON TUESDAY. THE BIGGEST QUESTION IS HOW FAR NORTH THIS AREA OF RAIN TRACKS. HAVE TOLEDO IN THE CHANCE CATEGORY...AND THE SOUTHEAST THIRD OF THE AREA IN CATEGORICAL POPS. THE COLD FRONT WILL CROSS THE AREA DURING THE DAY ON TUESDAY...WITH IMPROVEMENT FROM WEST TO EAST. THE BROAD UPPER LEVEL TROUGH WILL BEGIN TO LIFT OUT OF THE AREA ON TUESDAY ALLOWING FOR ZONAL FLOW TO DEVELOP FROM WEST TO EAST THROUGH THIS PERIOD. HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE GULF COAST STATES AND BRING DRIER AIR TO THE REGION. THE HIGH PRESSURE WILL BECOME THE DOMINATING WEATHER FEATURE THROUGH WEDNESDAY. A WARM FRONT WILL LIFT NORTHEAST ALONG WITH SOME LIMITED MEAN 1000 TO 500 MB MOISTURE ON THURSDAY AND WE COULD SEE A MINIMAL CHANCE FOR SHOWERS AND THUNDERSTORMS BY THURSDAY NIGHT. WILL HOLD ON TO THE SLIGHT CHANCE AT THIS POINT SINCE MOISTURE WILL BE SO LIMITED. AIR MASS BEHIND THE COLD FRONT IS NOT THAT STRONG SO NOT EXPECTING TOO MUCH IN THE WAY OF COLD AIR ADVECTION ON TUESDAY INTO TUESDAY NIGHT. LOWS WILL DROP OFF HOWEVER ABOUT 10 DEGREES TUESDAY NIGHT AND THEN BEGIN TO RECOVER WEDNESDAY AND WEDNESDAY NIGHT AS WARM AIR ADVECTION BEGINS TO TAKE PLACE. FURTHER WARMING TAKES PLACE THURSDAY AND THURSDAY NIGHT IN THE EARNEST WARM AIR ADVECTION. 850 MB TEMPERATURES CLIMB FROM 16C ON TUESDAY BACK TO AROUND 20C BY THURSDAY. && .LONG TERM /FRIDAY THROUGH MONDAY/... MODELS IN FAIR AGREEMENT TODAY. WILL START TO SEE PRECIP CHANCES INCREASE ON FRIDAY AS A MOIST SOUTHERLY FLOW DEVELOPS AHEAD OF A COLD FRONT. FRIDAY NIGHT AND SATURDAY WILL BE WET AND THE LIKELY POPS IN THE PREVIOUS FORECAST SEEM REASONABLE. THE COLD FRONT WILL MOVE SOUTH ACROSS THE AREA SATURDAY AND PRECIP SHOULD END DURING THE AFTERNOON. THERE WILL BE A DISTINCT AIR MASS CHANGE BEHIND THIS FRONT WITH DEW POINTS DIPPING INTO THE 40S AND TEMPERATURES BECOMING BELOW NORMAL. BY MONDAY...MORNING LOWS WILL BE IN THE 40S SOME AREAS WITH HIGHS STRUGGLING TO GET TO 70. WITH HIGH PRESSURE OVERHEAD THERE SHOULD BE A LOT OF SUNSHINE BOTH SUNDAY AND MONDAY. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... WEAK COLD FRONT TO OUR NORTHWEST WITH BEST GUESS POSITION FROM CENTRAL LWR MI SW INTO MO. MCS ACROSS MO AND SRN IL WHILE A FEW LINGERING SHOWERS ALONG WITH A LITTLE THUNDER ACROSS FAR EASTERN ERIE COUNTY PA AND EAST INTO WRN NY. THAT ACTIVITY WILL CONTINUE EAST OUT OF THE AREA OVER THE NEXT HOUR OR TWO. HRRR DOES SHOW SOME REDEVELOPMENT OVER ERIE COUNTY AND WILL ACCOUNT FOR THAT IN THE TAF. OTHERWISE MAINLY VFR ACROSS THE AREA THIS HOURS ALTHOUGH THE HRRR DOES SHOW ACTIVITY TO OUR WEST MOVING INTO THE AREA TOWARDS MORNING. EXPECT THE BULK OF THE CONVECTION TO REMAIN SOUTH OF OUR AREA...TRACKING ACROSS CENTRAL AND SRN OHIO...HOWEVER SO EXPECT SOME PRECIP TO EXTEND NORTH AND AFFECT THE AREA. BROUGHT SHOWERS INTO KTOL/KFDY AROUND 10Z AND KCLE/KMFD 11-12Z AND KERI- KYNG 14-15Z. ALSO INCLUDED VCTS BUT FOR NOW DID NOT INCLUDE THUNDER IN TEMPO GROUPS. HELD ONTO MVFR CIGS THROUGH THE BALANCE OF THE MORNING GIVEN DEEP HIGH RH ACROSS THE AREA. DRIER AIR SHOULD BEGIN MOVING IN THROUGH THE AFTERNOON. OUTLOOK...NON VFR LIKELY IN SHOWERS AND THUNDERSTORMS BY FRIDAY EVENING INTO SATURDAY WITH THE NEXT COLD FRONT. && .MARINE... SOUTHWEST TO SOUTH FLOW WILL CONTINUE TILL A COLD FRONT CROSSES THE LAKE ON TUESDAY. IT APPEARS SHOWERS AND THUNDERSTORMS WILL OCCUR ON THE LAKE THIS EVENING AND AGAIN RIGHT AHEAD OF THE COLD FRONT EARLY THURSDAY. SOME OF THE STORMS ON THE WEST END COULD BE STRONG THIS EVENING. LOOKS LIKE SPEEDS AND WAVES WILL REMAIN JUST BELOW SMALL CRAFT CRITERIA TONIGHT SO WILL HOLD OFF ON ANY ISSUANCE. THE FLOW WILL BECOME WESTERLY BEHIND THE FRONT. HIGH PRESSURE WILL BUILD OVER THE LAKE FOR THE MIDDLE PART OF THE WEEK RESULTING IN LIGHT AND VARIABLE FLOW. THE SURFACE RIDGE WILL EVENTUALLY MOVE OFF TO THE EAST ON THURSDAY ALLOWING A WEAK SOUTHERLY FLOW TO DEVELOP. S TO SW FLOW WILL THEN GRADUALLY INCREASE TILL A COLD FRONT CROSSES THE LAKE ON SATURDAY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...LOMBARDY NEAR TERM...LOMBARDY/OUDEMAN SHORT TERM...LOMBARDY/OUDEMAN LONG TERM...KUBINA AVIATION...TK MARINE...KUBINA
CONTINUE ON WITH THE FORECAST DISCUSSION...

IN A BASIC SENSE...THE MOVEMENT OF THUNDERSTORM SYSTEMS IS CONTROLLED BY THE AVERAGE OF THE WINDS ALOFT...OFTEN REFERRED TO AS THE STEERING WINDS. IN MOST CASES...THUNDERSTORMS WILL SIMPLY MOVE IN THE DIRECTION IN WHICH THE WINDS ALOFT ARE BLOWING. HOWEVER THE SECOND COMPONENT TO CONSIDER IS OFTEN REFERRED TO AS THE PROPAGATION COMPONENT OF STORM MOTION. PROPAGATION INFLUENCES STORM MOTION BY CHANGING THE DIRECTION OF MOTION OF A THUNDERSTORM SYSTEM IN THE DIRECTION THAT NEW THUNDERSTORMS DEVELOP. THIS IS THE MORE COMPLICATED FACTOR TO UNDERSTAND...BUT IN GENERAL...NEW THUNDERSTORMS TEND TO DEVELOP IN THE OPPOSITE DIRECTION OF THE LOW LEVEL JET. ON A DAY LIKE TODAY...WHERE THE STEERING WINDS ARE SOMEWHAT LIGHT DUE TO UPPER LEVEL RIDGING OVER TEXAS...BUT THE LOW-LEVEL JET IS RELATIVELY STRONG...THE PROPAGATION COMPONENT CAN DOMINATE THE DIRECTION IN WHICH THE THUNDERSTORM SYSTEM MOVES. FOR TODAY...THE STEERING WINDS ARE SOMEWHAT LIGHT AND WOULD INDICATE AN EASTERLY STORM MOTION. THIS IS WHY THE STORMS ARE JUST SORT OF SITTING THERE ALONG THE FRONT AS OF 3 AM. HOWEVER IF THIS RESULTS IN A STRONG ENOUGH COLD POOL (A COLLECTION OF RAIN COOLED AIR) THIS COLD POOL COULD START TO SURGE SOUTH...CAUSING NEW STORMS TO DEVELOP IN THE OPPOSITE DIRECTION OF THE LOW-LEVEL JET. SINCE THE LOW-LEVEL JET EXTENDS FROM OUR CWA TO THE FRONT...THE WHOLE COMPLEX OF STORMS COULD START TO MOVE SOUTH DIRECTLY TOWARDS THE RED RIVER...BUT WILL STILL MOVE AT LEAST SLIGHTLY TO THE EAST DUE TO THE STEERING WINDS ALOFT. THIS IS A DRAMATIC SHIFT IN DIRECTION FROM WHAT STORMS HAVE BEEN DOING OVERNIGHT...BUT IT MAKES SENSE IN THE CONTEXT OF WHAT WAS DESCRIBED ABOVE. THE MAIN POINT OF UNCERTAINTY THIS MORNING IS: WILL THUNDERSTORMS BECOME ORGANIZED ENOUGH TO MOVE AS A SYSTEM? THAT IS LARGELY UNKNOWN BECAUSE JUST LOOKING AT THE STORMS ON RADAR IS NOT ENOUGH TO DETERMINE HOW STRONG THE COLD POOL WILL GET...BUT THE FACT THAT THE HRRR AND THE TEXAS TECH WRF BOTH ADVERTISE A DRAMATIC SHIFT TO THE SOUTH OF THUNDERSTORMS TOWARDS THE RED RIVER AROUND SUNRISE GIVES CONFIDENCE IN THIS SOLUTION. WENT AHEAD AND PLACED A VERY SMALL AREA OF 20 POPS IN THE FORECAST FROM JUST NORTH OF SHERMAN EXTENDING TO THE SOUTHEAST INCLUDING MUCH OF LAMAR COUNTY. IF THE STORMS DO MOVE TO THE SOUTH AS THESE HIGH RESOLUTION MODELS INDICATE...THEY WILL BE IN THEIR DISSIPATING STAGES BY THE TIME THEY CROSS THE RED RIVER WELL AFTER SUNRISE THIS MORNING...SO NO STRONG OR SEVERE WEATHER IS EXPECTED AT THIS TIME. THIS AFTERNOON...MODELS CONTINUE TO CONSISTENTLY SHOW A SURGE OF TROPICAL MOISTURE TO THE NORTHWEST FROM THE TX GULF COAST THIS AFTERNOON. THIS SURGE OF MOISTURE APPEARS TO BE ASSOCIATED WITH A SUBTLE BUT IMPORTANT MID-LEVEL WIND SHIFT ASSOCIATED WITH DOLLY MOVING NORTHWEST TOWARDS THE NORTHERN MEXICO GULF COAST. THIS DEEPER TROPICAL MOISTURE IS EXPECTED TO REMAIN SOUTH OF THE INTERSTATE 20 CORRIDOR THIS AFTERNOON...SO REORIENTED POPS A BIT TO HIGHLIGHT THE SOUTHERN HALF OF THE CWA. IN GENERAL...THERE IS STILL NO OBVIOUS LIFT...SO THE COVERAGE OF STORMS WILL PROBABLY BE ISOLATED IN NATURE...AND LEFT POPS AT THE 20 PERCENT LEVEL FOR NOW. WEDNESDAY THROUGH FRIDAY...DOLLY IS EXPECTED TO MAKE LANDFALL OVER NORTHERN MEXICO LATE THIS EVENING...AND THEN CONTINUE OFF TO THE WEST-NORTHWEST THROUGH THE END OF THE WEEK. MODELS SEEM TO SEND THE DEEPER MID-LEVEL TROPICAL MOISTURE PLUME TO THE WEST WITH DOLLY...SO WENT AHEAD AND REMOVED POPS FROM THE FORECAST ON WEDNESDAY AFTERNOON ACROSS THE SOUTHERN CWA AND LEFT THE REMAINDER OF THE FORECAST DRY. WEAK UPPER LEVEL RIDGING IS THE DOMINANT FEATURE DURING THIS TIME FRAME...SO EXPECT SUBSIDENCE TO WIN OUT IN KEEPING THINGS DRY ACROSS NORTH AND CENTRAL TEXAS. THIS WEEKEND...MODELS CONTINUE TO HINT AT A COLD FRONT MOVING SOUTH OF THE RED RIVER SOMETIME SATURDAY AFTERNOON THROUGH SUNDAY MORNING. MODELS STILL SEEM TO INDICATE THAT THE PRIMARY REASON THAT THE FRONT MAKES IT SOUTH OF THE RED RIVER IS DUE TO PERSISTENT THUNDERSTORM ACTIVITY ALONG THE FRONT LATE THIS WEEK. IF THE FRONTAL MOTION IS REALLY DEPENDENT UPON PERSISTENT THUNDERSTORM ACTIVITY...CONFIDENCE IN THE TIMING AND PLACEMENT OF THE FRONT IS GOING TO REMAIN LOW UNTIL LATE THIS WEEK. THE BIGGEST REASON FOR OPTIMISM IN THE FRONT MAKING IT THIS FAR SOUTH IS OBSERVING WHAT HAPPENS TODAY. IF MCS ACTIVITY FROM THE OK/KS BORDER ACTUALLY SURGES SOUTH THIS MORNING...IT BECOMES EASY TO SEE HOW PERSISTENT STORMS TO OUR NORTH CAN SEND A STRONG OUTFLOW BOUNDARY/FRONT ACROSS NORTH TEXAS UNDER WEAK RIDGING ALOFT. THE FRONT IS MOST LIKELY TO BE IN PLACE OVER THE CWA ON SUNDAY...SO LEFT POPS MAINLY ALONG AND NORTH OF INTERSTATE 20 ON SATURDAY...AND KEPT THEM BROAD BRUSHED OVER THE ENTIRE CWA ON SUNDAY. EARLY NEXT WEEK...THE FRONT...ASSUMING IT MAKES IT HERE THIS WEEKEND...WILL PROBABLY DISSIPATE BY MONDAY. BECAUSE THE FRONT DOES NOT REPRESENT A TRUE AIRMASS REPLACEMENT...THAT IS...THERE IS NO CANADIAN/OR SIGNIFICANTLY COOL AIR TO THE NORTH OF THIS FRONT...IT WILL UNDERGO FRONTOLYSIS AND LOSE DEFINITION QUICKLY UNDER RIDGING ALOFT. LEFT THE FORECAST FOR EARLY NEXT WEEK DRY AS A RESULT. CAVANAUGH && .AVIATION... /ISSUED 1130 PM CDT MON SEP 1 2014/ VFR CONDITIONS AREA-WIDE WILL BECOME BRIEFLY INTERRUPTED BY A PERIOD OF MVFR DURING THE TUESDAY MORNING HOURS AS STRATUS SPREADS NORTHWARD IN THE SOUTHERLY LOW LEVEL FLOW. WE HAVE NOW INCLUDED MVFR CIGS INDISCRIMINATELY BASED ON THE MOST RECENT MODEL DATA...WITH ONSET AT 08Z IN KACT AND 11-12Z IN THE METROPLEX. CIGS SHOULD SCATTER OUT IN THE 15-17Z TIMEFRAME...OTHERWISE PERSISTENT SOUTH TO SOUTHEAST WINDS CAN BE EXPECTED. 30 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 97 77 96 77 96 / 5 5 5 5 0 WACO, TX 98 75 97 74 97 / 20 20 10 5 5 PARIS, TX 92 72 91 72 92 / 20 10 5 5 0 DENTON, TX 96 75 95 74 95 / 10 5 5 0 0 MCKINNEY, TX 95 74 94 74 94 / 10 5 5 5 0 DALLAS, TX 97 78 96 78 96 / 5 5 5 5 0 TERRELL, TX 96 76 96 75 96 / 10 10 5 5 0 CORSICANA, TX 97 76 96 75 96 / 20 20 10 5 5 TEMPLE, TX 98 72 97 73 97 / 20 20 10 5 5 MINERAL WELLS, TX 97 73 96 72 96 / 5 5 5 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
354 AM CDT TUE SEP 2 2014 .SHORT TERM... (Today and Tonight) Another mild night ongoing across West Central Texas, with south winds remaining strong enough to keep temperatures from dropping very much. Readings still right around 80 degrees at 3 AM (08Z). Models do indicate that some patchy low cloudiness will develop by sunrise and spread northward into the area, with low cloud satellite imagery showing some of this starting to develop across portions of Central Texas. Another hot day in store for the area, with the upper level ridge of high pressure in control. The 00Z NAM showed some convection across West Central Texas this afternoon, but the GFS is dry. Both the TTU WRF and the HRRR both show a similar pattern, scattered sea breeze activity pushing well inland today, but dissipating at sunset across Central Texas. Thus, will not insert PoPs into the forecast. After readings above the 100 degree mark at San Angelo and Abilene, models indicate a slight cooling at 850MB today as a little cooler and more moist air mass from the Gulf of Mexico slides into the area. Will keep afternoon highs below the 100 degree mark, but still a degree or two above guidance. Mild again tonight as south winds keep temperatures from dropping very quickly. Again, stayed just a little above guidance, as it has been too cool for the last several days. .LONG TERM... Surface temperatures fall 2 to 3 degrees F Wednesday as 850 MB temperatures fall another 1 to 2 degrees Celsius. Tropical Storm Dolly in the Bay of Campeche is expected to move into Mexico early Wednesday, and may send weak disturbances/moisture northward to affect the I-10 corridor Thursday and Friday. This is indicated mainly by the EC model, as the GFS model is dry and the NAM model nearly so. Will keep rain chances out of forecast for this time period, given the uncertainty and limited agreement in the models. For Saturday night into Sunday, however, both the GFS and EC modes are still indicating a weak cold front to bring a slight chance of showers and thunderstorms. Forecast already has rain chances in for this time period, and will maintain them. && .PRELIMINARY POINT TEMPS/POPS... Abilene 100 76 96 74 95 / 5 5 5 5 5 San Angelo 98 75 95 74 94 / 5 5 10 10 10 Junction 95 77 93 74 93 / 10 10 10 10 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07/04
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
355 AM CDT TUE SEP 2 2014 .SHORT TERM... 3 AM TEMPS WERE STILL IN THE LOWER 80S ACROSS MUCH OF THE SOUTHERN SOUTH PLAINS INTO THE ROLLING PLAINS...WHICH ISN/T SURPRISING GIVEN THE RECORD-SETTING WARMTH ACROSS THE AREA ON LABOR DAY. A WEAK COLD FRONT WAS LOCATED NEAR I-40...AND THERE WAS EVEN AN AREA OF LOW CLOUDS DEVELOPING NORTH OF THE FRONT ACROSS THE OKLA AND NRN TX PANHANDLES. ALOFT...A SHORTWAVE TROUGH IS MOVING FROM THE CENTRAL PLAINS INTO THE MIDWEST...WITH ONLY A WEAK REFLECTION INTO THE SRN HIGH PLAINS. THE FRONT IS EXPECTED TO MAKE SOME SWD PROGRESS THIS MORNING ACROSS THE WEST BEFORE STALLING/WASHING OUT THIS AFTERNOON...WITH A WEAK SURFACE LOW DEVELOPING ACROSS THE WESTERN SPLNS. THIS IN TURN SHOULD PRODUCE A WEAKLY CONVERGENT ZONE FROM THE CENTRAL SPLNS TO THE SOUTH-CENTRAL TX PANHANDLE...ALONG WITH A DIFFUSE DRYLINE. WITH LITTLE IF ANY UPPER-LEVEL SUPPORT...WE/LL HAVE TO RELY ON SURFACE-BASED LIFT TO GENERATE ANY MOIST CONVECTION TODAY. KLBB FCST SOUNDING SHOWS A WEAKLY CAPPED PROFILE THIS AFTERNOON...WITH NO CAP REMAINING FARTHER TO THE NORTH-NORTHEAST. THERE IS NOT A WHOLE LOT OF QPF SIGNAL IN MODEL SOLUTIONS...BUT THE 06 UTC HRRR AND RAP RUNS INDICATE ISOLATED DEVELOPMENT AS WELL AS THE SREF...WHICH SOMEWHAT BULLSEYES THE CAPROCK CANYONS AREA. WE WILL RUN WITH A 15-20 PERCENT CHANCE OF T-STORMS...CENTERED ACROSS BRISCOE COUNTY...AND ROUGHLY EXTENDING WEST TO I-27 AND SOUTH TO NEAR HWY 82. SHEAR APPEARS TO BE TOO WEAK TO SUPPORT MORE THAN PULSE-TYPE NON-SEVERE STORMS...BUT ML CAPES NEARING 2000 J/KG COULD SUPPORT SMALL HAIL...LOCALIZED WIND GUSTS TO 50 MPH...AND A BRIEF DOWNPOUR. STORMS SHOULD DIMINISH QUICKLY THIS EVENING WITH THE LOSS OF SFC-BASED INSTABILITY. SKIES SHOULD BE MOSTLY CLEAR TONIGHT ALTHOUGH SOME LOW STRATUS COULD INVADE FROM THE SOUTH EARLY WED MORNING. AS FOR TEMPS...FORTUNATELY WE SHOULD SEE THE HEAT OF THE PAST TWO DAYS BACK DOWN A BIT...ALTHOUGH WE WOULDN/T BE SURPRISED TO SEE A FEW LOCATIONS HIT 100 DEGREES IN THE LOW ROLLING PLAINS. HIGH TEMPS MAY ONLY REACH THE LOWER 90S IN THE FAR SW TX PANHANDLE DUE TO THE WEAK FRONT/S INFLUENCE...WITH MIDDLE TO UPPER 90S EXPECTED ELSEWHERE. && .LONG TERM... THE EXTENDED FORECAST FEATURES A WELCOME COOLING TREND EARLY ON WITH INCREASING RAIN CHANCES BY THE WEEKEND. INITIALLY...THE WESTERN EXTENT OF A LONGITUDINALLY BROAD UPPER RIDGE WILL HOLD SWAY OVER WEST TEXAS MID/LATE WEEK. THIS RIDGE WILL PROVIDE DRY AND WARM WEATHER...THOUGH DECREASING 1000-500 MB THICKNESSES AND 850 MB TEMPERATURES PROMISE A GRADUAL COOLING TREND. THINGS MAY EVENTUALLY BECOME MORE INTERESTING LATE WEEK INTO THE WEEKEND THOUGH THIS WILL BE AT LEAST PARTIALLY CONTINGENT ON WHETHER OR NOT A COLD FRONT MOVING THROUGH THE PLAINS CAN SETTLE INTO THE SOUTH PLAINS. THE COLD FRONT WILL MAKE ITS FIRST RUN SOUTHWARD BEHIND A POTENT SHORTWAVE TROUGH RIDING ACROSS THE NORTHERN TIER OF THE NATION AND SOUTHERN CANADA WEDNESDAY AND THURSDAY. CURRENT NWP HOLDS THE FRONT TO OUR NORTH ON FRIDAY...AS INCREASING AMOUNTS OF TROPOSPHERIC MOISTURE /POTENTIALLY ENHANCED BY REMNANTS OF DOLLY AND A TAP OFF A TROPICAL CYCLONE YET TO FORM IN THE EASTERN PACIFIC/ ARE FUNNELED AROUND THE RIDGE INTO THE DESERT SOUTHWEST. THE BEST RAIN CHANCES WILL LIKELY REMAIN FOCUSED TO NORTH AND WEST FRIDAY INTO FRIDAY NIGHT...AND WE HAVE DECREASED POPS SOMEWHAT OVER THIS PERIOD. THE LATEST ITERATION OF THE GFS AND ECMWF NOW TEND TO KEEP THE UPPER RIDGE CENTERED CLOSE ENOUGH THROUGH THE WEEKEND TO MAKE IT A LITTLE MORE UNCERTAIN WHETHER WE WILL FULLY BE ABLE TO TAP THE SUB-TROPICAL AND TROPICAL MOISTURE. EVEN SO...THE NWP SUGGESTS THE OUTFLOW AIDED FRONT WILL SAG INTO THE SOUTH PLAINS SOMETIME OVER THE WEEKEND /AS EARLY AS FRIDAY NIGHT WITH THE ECMWF OR NOT UNTIL SATURDAY NIGHT IN THE GFS/. REGARDLESS...IF THE FRONT CAN MAKE IT INTO THE CWA IT WILL BRING MORE SIGNIFICANT COOLING ALONG WITH ENHANCED RAIN CHANCES. GIVEN THE UNKNOWNS...WE HAVE NOT MADE MANY ADJUSTMENTS TO THE FORECAST OVER THE WEEKEND AND HAVE MAINTAINED THE HIGHEST POPS SATURDAY NIGHT...WHEN CONFIDENCE IS HIGHEST OF THE QUASI-STATIONARY FRONT RESIDING SOMEWHERE LOCALLY. THE FRONT WILL THEN LIFT BACK NORTHWARD EARLY NEXT WEEK AS PRESSURES FALL ACROSS THE HIGH PLAINS...DOWNSTREAM OF A WESTERN STORM SYSTEM. THIS WILL RESULT IN WARMER AND DRIER WEATHER FOR WEST TEXAS. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 92 64 93 64 89 / 10 10 10 10 10 TULIA 95 67 94 66 90 / 20 10 10 10 0 PLAINVIEW 94 66 93 67 90 / 20 10 0 0 0 LEVELLAND 95 67 93 67 89 / 10 10 10 10 10 LUBBOCK 97 70 93 68 90 / 10 10 0 0 0 DENVER CITY 97 67 93 67 89 / 10 10 10 10 10 BROWNFIELD 97 68 93 68 90 / 10 10 0 0 10 CHILDRESS 98 72 97 73 96 / 10 10 0 0 0 SPUR 97 69 96 71 93 / 10 10 0 0 10 ASPERMONT 98 73 98 73 96 / 10 10 0 0 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 33/23
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
149 AM EDT TUE SEP 2 2014 .SYNOPSIS... WEAK HIGH PRESSURE WILL REMAIN OVER THE REGION TONIGHT INTO MUCH OF TUESDAY. A WEAK COLD FRONT TRACKS SOUTHEAST INTO OUR AREA BY TUESDAY EVENING...BEFORE STALLING ACROSS THE CAROLINAS AND WASHING OUT ON WEDNESDAY. HIGH PRESSURE SETS BACK UP OVER THE EAST BY FRIDAY WITH YET ANOTHER COLD FRONT MOVING TOWARD US THIS WEEKEND. && .NEAR TERM /THROUGH TODAY/... AS OF 138 AM EDT TUESDAY... MADE SOME MINOR ADJUSTMENTS IN TEMPERATURES AND POPS FOR THIS MORNING. AS OF 850 PM EDT MONDAY... OTHER FOR ISOLATED SHRA/TSRA PASSING ACROSS THE FAR NORTH...CONVECTION REMAINS LIMITED THIS EVENING AS SOUNDINGS SHOW WEAK CAPPING ALOFT WITHIN A DEEP WESTERLY FLOW REGIME. THIS ALONG WITH LACK OF DEEP INSTABILITY SHOULD KEEP THINGS MAINLY QUIET OVERNIGHT WITH JUST SOME PATCHY FOG IN THE VALLEYS AND PERHAPS OUT EAST. HOWEVER WITH THE LATEST HRRR TRACKING THE CURRENT ISOLATED COVERAGE OVER GREENBRIER EAST TOWARD THE SOUTHERN SHENANDOAH VALLEY...WILL LEAVE IN SOME LOW POPS ACROSS THE EXTREME NORTH SINCE HEADING INTO SOME DECENT LEFTOVER CAPE DESPITE LOSS OF HEATING. WILL ALSO CONTINUE SOME LOW CHANCES FAR NW LATE FOR ACTIVITY COMING IN AHEAD OF THE UPSTREAM FRONT AROUND DAYBREAK. OTRW FEW CHANGES OTHER THAN TO INCLUDE A BIT OF FOG AND BUMP UP TEMPS IN SPOTS GIVEN SUCH A MUGGY OVERNIGHT. ANOTHER SHORTWAVE AHEAD OF A FRONT SHIFTING SE INTO THE OHIO VALLEY PASSES ACROSS TUESDAY MORNING. FOR NOW IT LOOKS LIKE THE WESTERN CWA WILL SEE A CHANCE OF SHOWERS/ISOLATED TSRA DURING THE MORNING BUT AGAIN EAST OF THE BLUE RIDGE LOOKS FEEBLE. THERE IS GOOD SUBSIDENCE BEHIND THIS FEATURE BY 18Z TUESDAY BUT ANOTHER WAVE AND THE FRONT ITSELF WILL EDGE CLOSER TOWARD TUE EVENING...WHICH WILL BRING A BETTER THREAT OF SHOWERS AND STORMS TO THE MOUNTAINS WITH ISOLATED TO WIDELY SCATTERED COVERAGE OVER THE FOOTHILLS AND PIEDMONT. TUESDAY WILL BE HOT...WITH ENOUGH SUN TO SEND TEMPS INTO THE LOWER TO MID 90S EAST...AND LOWER TO MID 80S WEST. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... AS OF 224 PM EDT MONDAY... A WEAK COLD FRONT SLIDES ACROSS THE REGION TUESDAY NIGHT...PUSHING PRECIPITATION TO THE EAST COAST. HIGH PRESSURE BUILDS IN FROM THE WEST THROUGH WEDNESDAY. THE ASSOCIATED DEW POINT FRONT AND DRIER AIR IS LAGGING WAY BEHIND AND DOES NOT ENTER THE FORECAST AREA UNTIL LATE WEDNESDAY MORNING. THIS DEW POINT FRONT MAY MAKE IT AS FAR AS THE VA/NC BORDER WEDNESDAY AFTERNOON...THEN BEGINS TO RETREAT TO THE NORTH WEDNESDAY NIGHT AND THURSDAY. SURFACE HIGH PRESSURE WILL KEEP MOST OF THE AREA DRY BUT COULD SEE ISOLATED DIURNAL SHOWERS SOUTH OF THE DEW POINT FRONT WEDNESDAY AFTERNOON/EVENING. AS THIS SURFACE RIDGE DRIFTS OFF THE MID ATLANTIC COAST THURSDAY...SOUTHEAST FLOW AND ATLANTIC MOISTURE WILL INCREASE THE CHANCE FOR SHOWERS FOR AREAS ALONG AND EAST OF THE BLUE RIDGE...ESPECIALLY THE NORTH CAROLINA HIGH COUNTY THURSDAY AFTERNOON. EVEN THOUGH FLOW IS WEAK ALOFT...WARM SOUTHWEST FLOW WILL OVERRUN THIS RIDGE/INSITU WEDGE TO PRODUCE A LOW STRATUS DECK AND A CHANCE FOR LIGHT RAIN/DRIZZLE FOR AREAS EAST OF THE BLUE RIDGE OVERNIGHT THURSDAY. TEMPERATURES WILL RANGE FROM THE UPPER 70S TO LOWER 80S ACROSS THE MOUNTAINS AND UPPER 80S TO LOWER 90S EAST WEDNESDAY AFTERNOON. EASTERLY FLOW THURSDAY WILL PRODUCE UNIFORM TEMPERATURES IN THE 80S. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 248 PM EDT MONDAY... HIGH PRESSURE EXITS THE MID ATLANTIC COAST ON FRIDAY AND WILL BE REPLACED BY A LEE TROUGH. WITH AN UPPER LEVEL RIDGE ACROSS THE GULF STATE TO THE SOUTHEAST COAST...NEARLY ZONAL FLOW MAY BRING A SHORT WAVE OVER THE REGION FRIDAY. THIS SHORT WAVE WILL HELP SPARK CONVECTION THROUGH THE AFTERNOON AND EVENING HOURS. IF THIS SHORT WAVE DOES NOT MATERIALIZE...DIURNAL CONVECTION IS STILL POSSIBLE WITH ABUNDANT MOISTURE...AFTERNOON HEATING AND A LEE TROUGH. FOR THE WEEKEND...A COLD FRONT IS EXPECTED TO PASS OVER THE REGION SATURDAY (GFS) OR SUNDAY (ECM). WITH A STUBBORN UPPER LEVEL RIDGE TO THE SOUTH...FAVORING THE SLOWER ECM RUN. PREFRONTAL OR DIURNAL CONVECTION IS POSSIBLE SATURDAY BUT WILL KEEP THE HIGHEST POPS WITH THE FRONTAL PASSAGE SUNDAY. NOT QUITE SURE IF THE FRONT WILL COMPLETE CLEAR THE FORECAST AREA AS THE UPPER LEVEL RIDGE CONTINUES TO HANG ACROSS THE SOUTHERN STATES. TEMPERATURES WILL REMAIN WARMER THAN NORMAL UNTIL THE FRONT CLEARS THE AREA. ONCE THE FRONT PASSES...TEMPERATURES WILL RUN COOLER THAN NORMAL WITH HIGHS IN THE 70S. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 140 AM EDT TUESDAY... OVERALL VFR SHOULD PREVAIL THIS MORNING AT THE TAF LOCATIONS. A FEW SHOWERS MAY MAKE A RUN AT KLWB OVER THE NEXT COUPLE OF HOURS BUT LIKELY TO DISSIPATE CROSSING THE RIDGES SO LEAVING OUT MENTION. WELL MIXED LOW LEVELS WILL LIKELY INHIBIT MUCH FOG DEVELOPMENT THIS MORNING. CANT TOTALLY RULE OUT SOME BRIEF VALLEY FOG AT KLWB/KBCB ALTHOUGH FORECAST FOG STABILITY VALUES SHOW ONLY SPOTTY COVERAGE AT BEST. UPPER TROUGH AND ITS ASSOCIATED COLD FRONT WILL APPROACH FROM THE NORTHWEST THIS AFTERNOON WITH MOSTLY ISOLATED MOUNTAIN SHOWERS/STORMS EXPECTED DURING THE DAY AHEAD OF THE BOUNDARY. HOWEVER MAY SEE A MORE ORGANIZED BAND DROP IN FROM THE NW WITH THE LEADING PRE- FRONTAL CONVERGENCE...SO INCLUDING A VCTS MENTION ACROSS THE SOUTHEAST WEST VA SITES AROUND MID AFTERNOON AND LATE AT KBCB. OTRW EXPECTING MOSTLY VFR AFTER EARLY MID DECK ERODES AND SCATTERED- BROKEN CU FIELDS BETWEEN 4-6K FT TAKE SHAPE WITH HEATING. WIDELY SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS EVENING INTO TONIGHT. MEDIUM TO HIGH CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE PERIOD. EXTENDED AVIATION DISCUSSION... FRONT SETTLES CLOSER TUESDAY NIGHT INTO WEDNESDAY...WHEN BETTER COVERAGE OF SHRA/TSRA IS EXPECTED. HOWEVER LOW CONFIDENCE ON THE TIMING AND SOUTHWARD POSITION OF THE BOUNDARY ON WEDNESDAY AT THIS POINT PENDING PRE-FRONTAL COVERAGE FROM TUESDAY NIGHT. FOR NOW APPEARS MAINLY VFR OUTSIDE OF EARLY MORNING FOG WEDNESDAY...THEN PERIODS OF MVFR WEDNESDAY AFTERNOON ESPECIALLY SOUTHERN SECTIONS...AND MAINLY ACROSS THE SOUTH/SOUTHWEST THURSDAY AFTERNOON FOR MORE ISOLATED NATURE COVERAGE. FRONT WASHES OUT TO THE SOUTH OF THE AREA FRIDAY WITH MORE WIDELY SCATTERED DIURNAL NATURE SHOWERS AND STORMS...THEN PERHAPS BECOMING MORE WIDESPREAD SATURDAY WITH PERIODIC MVFR IN MORE ORGANIZED COVERAGE AHEAD OF ANOTHER COLD FRONT ARRIVING FROM THE NORTHWEST LATE. OTRW WILL SEE A DAILY TREND OF EARLY MVFR/IFR IN FOG...FOLLOWED BY BRIEF VFR...THEN INCREASING AFTERNOON/EVENING CONVECTION WHEN MVFR TO LOCAL IFR WILL BE POSSIBLE. && .EQUIPMENT... AS OF 730 AM EDT FRIDAY ... THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...WILL BE OUT OF SERVICE UNTIL FURTHER NOTICE. A PART HAS BEEN BACK-ORDERED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/WP NEAR TERM...JH/WP SHORT TERM...RCS LONG TERM...RCS AVIATION...JH/KK EQUIPMENT...RAB
AREA FORECAST DISCUSSION
NWS ALBANY NY
843 AM EDT TUE SEP 2 2014 .SYNOPSIS... HIGH PRESSURE OFFSHORE WILL SUPPLY THE REGION WITH ANOTHER DAY OF A SOUTHWEST FLOW WHICH WILL BRING VERY WARM TEMPERATURES ONCE MORE. A COLD FRONT WILL APPROACH THE REGION LATE TODAY INTO THE EVENING BRINGING SHOWERS AND THUNDERSTORMS...SOME OF WHICH COULD CONTAIN HEAVY RAINFALL AND GUSTY WINDS. SLIGHTLY COOLER AND NOTICEABLY DRIER AIR WILL FOLLOW ON WEDNESDAY. THE DRY WEATHER IS EXPECTED TO CONTINUE THE REST OF THE WORK WEEK WITH WARMING TEMPERATURES ONCE MORE. && .NEAR TERM /THROUGH TONIGHT/... AS OF 841 AM EDT...QUICK UPDATE TO ACCOUNT FOR ISOLD SHOWERS AHEAD OF A WEAK SFC TROUGH IN THE WARM SECTOR. SOME SHOWERS ARE ACROSS THE MOHAWK VALLEY...AND MOVED THROUGH THE CAPITAL REGION...AND THE BERKSHIRES AND SRN VT. THESE SHOWERS WITH PERHAPS A RUMBLE OF THUNDER WILL LIMIT THE HEATING THIS MORNING. THE BETTER FORCING FOR SOME STRONGER THUNDERSTORMS AHEAD OF THE COLD FRONT LOOK LIKE THEY WILL NOT REACH THE WRN PERIPHERY OF THE FCST AREA UNTIL 22Z- 00Z BASED ON THE LATEST HRRR GUIDANCE. THE FOG WAS ALSO REMOVED FROM THE GRIDS...AND THE CLOUD COVER WAS INCREASED OVER THE NRN AND CNTRL THIRD. THE H500 TEMP THIS MORNING IS -6C WITH KBUF -8C. THE 12Z KALB RAOB INDICATES A STRONG LOW TO MID LEVEL CAP IS BETWEEN 750-650 HPA WHICH WILL CURTAIL ANY STRONG TO POSSIBLY SEVERE THREAT UNTIL THE LATE PM/EARLY EVENING. OTHERWISE IT WILL BECOME RATHER HOT AGAIN ONCE MORE AS TEMPERATURES CREST WELL INTO THE 80S. IN THE MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY AMBIENT TEMPERATURES COULD TOUCH 90. COMBINE THAT WITH DEWPOINTS AROUND 70...AND THE APPARENT TEMPERATURES WILL REACH THE MID AND UPPER 90S...SHORT OF ADVISORY CRITERIA. HILLTOWNS WILL HAVE APPARENT TEMPERATURES GENERALLY IN THE 85-90 RANGE. A SOUTH TO SOUTHWEST WIND WILL AVERAGE 5 TO 15 MPH. A COLD FRONT...CURRENTLY WORKING THROUGH THE OHIO VALLEY...IS FORECAST TO CROSS OUR REGION LATE THIS AFTERNOON TO THE NORTH AND WEST OF ALBANY...AND DURING THE EARLY EVENING ALBANY SOUTH AND EAST. THE ENTRANCE OF A POTENT UPPER LEVEL JET (NEAR 100 KTS) LOOKS TO MOVE ACROSS THE REGION THIS EVENING. THE BEST FORCING STILL LOOKS TO LIFT NORTHWEST OF OUR REGION BUT IT LOOKS CLOSER THAN THIS TIME YESTERDAY. THIS JET WILL INCREASE THE DEEP LAYER WIND SHEAR. COMBINE THAT WITH PRETTY GOOD INSTABILITY (SBCAPES AVERAGING AROUND 1500 J/KG)...AND IT IS A GOOD BET SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON TO OUR WEST AND MOVE NORTHWEST TO SOUTHEAST. MITIGATING FACTORS INCLUDE A MODEST MID LEVEL LAPSE RATES...ONLY AROUND 5.5 C/KM. ALSO...THE CAP THAT WAS DISCUSSED EARLY MIGHT PERSIST INTO THIS EVENING...WHICH COULD CONTINUE TO HINDER CONVECTION...ALTHOUGH IT IS RATHER WEAK. IF THUNDERSTORMS DO GET GOING...THEY WILL HAVE A HEALTHY WIND FIELD TO WORK WITH...WHICH COULD ALLOW FOR BOWING SEGMENTS AND PERHAPS A SQUALL LINE TO DEVELOP. THESE COULD PRODUCE STRONG TO DAMAGING WIND GUSTS. SPC CONTINUES TO ONLY HIGHLIGHT THE SOUTHWESTERN PORTION OF THE MOHAWK VALLEY IN "SLIGHT RISK" FOR SEVERE THUNDERSTORMS. HOWEVER WE WILL CONTINUE TO USE POSSIBLE GUSTY WINDS AND HEAVY RAINFALL EVERYWHERE ACROSS OUR REGION. BY FAR...THE BIGGEST THREAT TODAY WOULD BE DAMAGING WIND...AND WITH ONLY A VERY SMALL CHANCE FOR LARGE HAIL IN THE BIGGEST UPDRAFTS. THUNDERSTORM ACTIVITY WILL PERSIST INTO THE EVENING HOURS...BUT AS THE COLD FRONT MOVES BY...LINGERING SHOWERS AND WEAKENING THUNDERSTORMS SHOULD DISSIPATE BY AROUND MIDNIGHT. A SLIGHTLY COOLER AND DRIER AIR MASS WILL MOVE IN OVERNIGHT...LOWERING TEMPERATURES FROM THE MID 50S NORTHWEST OF THE CAPITAL REGION...TO THE LOWER TO MID 60S ALBANY SOUTHWARD. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... WEDNESDAY WILL FEATURE A GOOD DEAL OF SUNSHINE...A NORTHWEST BREEZE 10-15 MPH AND HIGH TEMPERATURES 80-85 IN THE VALLEYS (WARMEST NEAR POUGHKEEPSIE) MID TO UPPER 70S OVER THE HIGHER TERRAIN. DEWPOINTS WILL DROP INTO THE 50S. WEDNESDAY NIGHT AS HIGH PRESSURE MOVES OVERHEAD...AND THE SKY IS EXPECTED TO CLEAR...TEMPERATURES WILL DIP INTO THE 50S REGION WIDE WITH MID TO UPPER 40S ACROSS THE ADIRONDACKS AND PORTIONS OF THE SOUTHERN GREENS. IT LOOKS AS IF SOME PATCHY FOG SHOULD FORM OVERNIGHT. THURSDAY...HIGH PRESSURE WILL BEGIN TO DRIFT OFFSHORE...ALLOWING A SOUTHERLY FLOW TO BEGIN TO PUMP WARMER AND SLIGHTLY MORE HUMID AIR BACK INTO THE REGION. HIGHS WILL REACH AROUND 80 OVER THE HIGHER TERRAIN...CLOSER TO 85 IN THE VALLEYS. DEWPOINTS WILL BE AROUND 60. THURSDAY NIGHT WILL BE MILD WITH LOWS RANGING FROM THE UPPER 50S IN OUTLYING AREAS...60S MOST OTHER PLACES...LOCALLY UPPER 60S IN THE CAPITAL REGION. && .LONG TERM /FRIDAY THROUGH MONDAY/... THE LARGE AND WARM HIGH PRESSURE SYSTEM WILL HOLD OVER THE REGION FOR MOST OF FRIDAY WITH SLOWLY INCREASING CLOUDS EXPECTED AND HIGHS IN THE 80S AS 850 MB TEMPS REACH +16 TO +18 DEG CELSIUS. LATE IN THE DAY THERE IS A CHANCE OF SHOWERS OR TSTMS ACROSS THE NORTHWEST PART OF THE FORECAST AREA AS A COLD FRONT AND UPPER LEVEL TROF APPROACH FROM THE WEST. FRI NIGHT INTO SATURDAY...MOST ACTIVE PORTION OF THE LONG TERM WITH A COLD FRONT INTERACTING WITH A MOIST AND UNSTABLE AIR MASS. MODEL TIMING OF THE BOUNDARY IS STILL VARIABLE...BUT THE MODELS ARE CLOSER THAN THEY WERE 24 HOURS AGO. ALL THE MEDIUM RANGE MODELS NOW AGREE THAT ANY SHOWERS ASSOCIATED WITH THIS FRONTAL BOUNDARY WILL BE OUT OF THE REGION BEFORE SUNDAY...WITH SOME MODELS MUCH SOONER. WILL CONTINUE TO KEEP CHANCE POPS ACROSS THE REGION FRIDAY NIGHT AND SATURDAY...THEN LOWER POPS TO ONLY SLIGHT CHANCE BY LATE SATURDAY NIGHT. LOWS FRIDAY NIGHT WILL BE IN THE UPPER 50S AND 60S. HIGHS SATURDAY IN THE UPPER 60S ACROSS THE ADIRONDACKS...AND THE 70S TO LOWER 80S ELSEWHERE. LOWS SATURDAY NIGHT IN THE UPPER 40S AND 50S AS THE COOLER AIR BEHIND THE FRONT BEGINS TO SEEP IN. ON SUNDAY A SPRAWLING HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION AND CONTROL OUR WEATHER INTO EARLY NEXT WEEK. THIS HIGH PRESSURE AREA IS OF CANADIAN ORIGIN SO IT WILL BE NOTICEABLY COOLER SUNDAY AND MONDAY. HIGHS SUNDAY AND MONDAY WILL BE IN THE MID 60S TO MID 70S. LOWS SUNDAY NIGHT IN THE MID 40S TO MID 50S. && .AVIATION /13Z TUESDAY THROUGH SATURDAY/... ANY LEFTOVER FOG/STRATUS AT KGFL/KPSF WILL BE GONE BY 13Z... OTHERWISE THE TAF SITES WILL FEATURE VFR CONDITIONS UNTIL A SHORTWAVE TROF AND COLD FRONT APPROACH FROM THE WEST LATE IN THE DAY AND MOVE THROUGH THE TAF SITES THIS EVENING. SOME ISOLD SHOWERS ASSOCIATED WITH A PREFRONTAL SFC TROUGH MAY GET CLOSE TO TERMINALS...AND A VCSH GROUP WAS USED AT KALB BTWN 12Z-16Z. BEGINNING 21Z TO 23Z HAVE FORECASTED A 4-6 HOUR WINDOW OF PROB30 FOR MVFR CONDITIONS DUE TO THUNDERSTORMS AT ALL THE TAF SITES. THE THREAT FOR TSTMS WILL END WHEN THE COLD FRONT MOVES THROUGH BETWEEN 02Z AND 04Z TUESDAY NIGHT. SURFACE WINDS WILL BECOME SOUTH OR SOUTHWEST AT 5 TO 10 KTS TODAY INTO THIS EVENING...THEN SHIFT TO WESTERLY BEHIND THE COLD FRONT AT 4 TO 8 KTS. OUTLOOK... WEDNESDAY TO FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY NIGHT TO SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. && .FIRE WEATHER... HIGH PRESSURE WILL MOVE EAST OF OUR REGION TODAY ALLOWING A COLD FRONT TO MOVE IN LATE TODAY INTO THIS EVENING. THIS FRONT WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS TO THE AREA...MAINLY LATE THIS AFTERNOON INTO THE EARLY EVENING HOURS. IT WILL BE A RATHER HOT DAY WITH PARTIAL SUNSHINE BEFORE THE SHOWERS AND STORMS ARRIVE. RH VALUES WILL ONLY DROP TO THE 55-65 PERCENT RANGE THIS AFTERNOON. A SOUTH TO SOUTHWEST WIND WILL AVERAGE 5-15 MPH. RAINFALL FROM THE THUNDERSTORMS LOOK REACH AROUND A QUARTER INCH OR BETTER IN MOST AREAS FROM ALBANY NORTHWARD...A QUARTER INCH OR LESS SOUTH OF ALBANY. HOWEVER...ANY THUNDERSTORM COULD PRODUCE HEAVY RAINFALL PRODUCING LOCALIZED AMOUNTS EASILY EXCEEDING AN INCH IN ANY GIVEN SPOT. RH VALUES TONIGHT WILL BE IN THE TYPICAL 80-100 PERCENT RANGE ALTHOUGH A BIT OF BREEZE MIGHT PERSIST IN MANY AREAS...AS THE WIND SHIFTS FROM SOUTHWEST TO NORTHWEST. WEDNESDAY WILL FEATURE LOWER HUMIDITY ALONG WITH A GOOD DEAL OF SUNSHINE. A NORTHWEST BREEZE WILL AVERAGE 10-15 MPH WITH SOME HIGHER GUSTS INTO THE 20S...MAINLY OVER THE HIGHER TERRAIN/MOHAWK VALLEY AND GREATER CAPITAL REGION. AFTERNOON RH VALUES WILL DROP INTO THE 35-45 PERCENT RANGE. A FULL RECOVERY WEDNESDAY NIGHT WITH THE WIND GOING CALM...AND RH VALUES NEAR 100 PERCENT WITH PLENTY OF DEW EXPECTED. THE NEXT CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE LATE FRIDAY INTO SATURDAY. && .HYDROLOGY... IT WILL BE MAINLY DRY THROUGH MIDDAY. THEN...SHOWER AND THUNDERSTORM COVERAGE SHOULD INCREASE FROM NORTHWEST TO SOUTHEAST THROUGH THE AFTERNOON INTO THE EARLY EVENING. AVERAGE BASIN RAINFALL WITH THESE STORMS IS PROJECTED TO BE AROUND HALF AN INCH ACROSS NORTHERN AREAS OF OUR HYDROLOGICAL SERVICE AREA (HSA)...NORTH OF ALBANY. LOOK FOR AROUND HALF AN INCH IN AND AROUND THE CAPITAL REGION...AND LESSER AMOUNTS OF A QUARTER INCH OR LESS FURTHER SOUTH. PWATS ARE EXPECTED TO EXCEED TWO INCHES TODAY. THIS WILL ALLOW FOR THE POTENTIAL FOR ANY THUNDERSTORM TO PRODUCE LOCALLY MUCH HEAVY RAINFALL...POSSIBLY EXCEEDING AN INCH AND THIS RAIN COULD FALL IN A SHORT TIME. THEREFORE THERE IS THE POTENTIAL FOR SIGNIFICANT PONDING OF WATER ON ROADWAYS AND AREAS OF POOR DRAINAGE. WHILE THE THREAT FOR ANY ORGANIZED FLASH FLOODING IS VERY LOW...A HIGH LOCALIZED FLASH FLOOD CANNOT BE RULED OUT. DRIER WEATHER RETURNS BY WEDNESDAY...LASTING THROUGH THE REMAINDER OF THE WORKWEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...HWJIV/WASULA NEAR TERM...HWJIV/WASULA SHORT TERM...HWJIV LONG TERM...GJM AVIATION...GJM/WASULA FIRE WEATHER...HWJIV/NAS HYDROLOGY...HWJIV/NAS
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1130 AM EDT TUE SEP 2 2014 .UPDATE (REST OF TODAY AND TONIGHT)... 15Z WATER VAPOR AND H4 RAP ANALYSIS SHOW THE MAIN NORTHERN STREAM FLOW FAR TO OUR NORTH ALONG THE CANADIAN BORDER AND OVER TOP AN ELONGATED WEST TO EAST ORIENTED UPPER RIDGE EXTENDING ACROSS THE SOUTHERN TIER OF THE CONUS. OUR FORECAST AREA RESIDES UNDER THIS LARGE UPPER RIDGE...HOWEVER A TUTT FEATURE RETROGRADING WESTWARD OVER THE BAHAMAS IS BEGINNING TO ERODE THE RIDGE TO OUR SOUTH AND EAST...AND WILL BEGIN TO BREAK DOWN THE RIDGE OVER OUR HEADS TONIGHT. 02/12Z SOUNDING PROFILE SHOWS THE INFLUENCE OF THE UPPER RIDGE OVERHEAD WITH A SUBSIDENCE INVERSION SIGNATURE AROUND 750MB. ABOVE THIS LAYER IT ON THE DRY SIDE. THE RESULTING PW IS LOW AROUND 1.7"...WHICH IS BELOW AVERAGE FOR EARLY SEPTEMBER...BUT NOT AN EXTREME VALUE. WE HAVE SEEN A BIT OF COOLING IN THE MID-LEVELS SINCE MONDAY...POSSIBLY THE VERY BEGINNING INFLUENCE OF THE APPROACHING TUTT. WILL EXPECT TO SEE ANOTHER DEGREE OR 2 OF COOLING IN THE MID-LEVELS OVER THE NEXT 24 TO 36 HOURS AS THE TUTT PASSES JUST TO OUR SOUTH. THIS COOLING ALONG WITH OUR EVENTUAL POSITION ON THE EASTERN PERIPHERY OF THE TUTT (FAVORED FOR UPWARD MOTION AND CONVECTION) MAY LEAD TO ENHANCED CONVECTION LATER IN THE WEEK. BACK TO TODAY. SOME MIXED SIGNALS REGARDING CONVECTIVE TIMING AND EVOLUTION FOR THE AFTERNOON AND EVENING. HIRES CONVECTION ALLOWING MODELS ARE KIND OF SPLIT...WITH A FEW MEMBERS RATHER ACTIVE ALONG THE I-75 CORRIDOR LATER TODAY...AND A FEW MEMBERS WHO HAVE TROUBLE GENERATING MUCH CONVECTION...AND ESPECIALLY DEEP CONVECTION. MORE THAN LIKELY IT IS DIFFERING WAYS THE GUIDANCE IS HANDLING THE SUBSIDENCE OF THE UPPER RIDGE RESULTING IN THE DIFFERENCES. AM TENDING TO SIDE ON THE MORE ACTIVE CONVECTION SOLUTIONS. THE SUBSIDENCE INVERSION IS THERE...BUT IS NOT REALLY PRONOUNCED. GIVEN THE WEAKNESS OF THE OVERALL SUBSIDENCE AND THE EASTERLY FLOW BEING FAVORED FOR ENHANCED CONVERGENCE/UPDRAFTS ALONG THE FLORIDA WEST COAST WILL KEEP HIGH END CHANCE POPS IN THE FORECAST ALONG THE ENTIRE I-75 CORRIDOR. SIMILAR TO THE PAST FEW DAYS...THE STORMS ARE LIKELY TO BREAK OUT FIRST DURING THE EARLY/MID AFTERNOON DOWN TOWARD FORT MYERS AND OVER THE INTERIOR SOUTH (HIGHLANDS/DESOTO/HARDEE COUNTIES)...AND THEN MIGRATE/EVOLVE NORTH AND WEST INTO THE TAMPA BAY AREA AND NATURE COAST DURING THE LATE AFTERNOON/EARLY EVENING. THE EASTERLY FLOW JUST ABOVE THE SURFACE IS 8-10 KNOTS THIS AFTERNOON WHICH WILL SLOW THE INLAND PROPAGATION OF THE SEA-BREEZE...BUT NOT STOP IT. THEREFORE...WOULD EXPECT THE BREEZE TO BE SET UP NEAR OR JUST INSIDE OF I-75 BY LATE AFTERNOON...AND IT WILL BE THIS ZONE WHERE STORMS WILL IGNITE AS THE EAST COAST SEA-BREEZE ARRIVES AND INTERACTS. STORM MOTION WILL BE WESTWARD AFTER INITIATION...SO MARINERS SHOULD BE AWARE OF THE WEATHER OVER LAND TO THEIR EAST AND BE PREPARED FOR STORMS TO RAPIDLY DEVELOP AND MOVE OFFSHORE LATER TODAY. THE ACTIVITY WILL ALL PUSH OFFSHORE WITHIN A COUPLE HOURS OF SUNSET AND PROVIDE THE REGION WITH A MOSTLY DRY AND SEASONABLE OVERNIGHT PERIOD. && .AVIATION... VFR CONDITIONS PREVAIL ACROSS THE REGION LATE THIS MORNING. BEGINNING TO SEE THE FIRST OF A CU FIELD BEGIN TO DEVELOP. SCT SHOWERS AND STORMS WILL BE MOVING EAST TO WEST ACROSS THE PENINSULA DURING THE AFTERNOON. KFMY/KRSW/KPGD WILL BE FIRST TO SEE THE STORMS IN THE VICINITY BY MID AFTERNOON. FURTHER NORTH AROUND THE TAMPA BAY TERMINALS STORMS ARE LIKELY TO BE LATER IN THE AFTERNOON AND EVENING HOURS. AWAY FROM ANY STORMS...VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. && .MARINE... EAST SOUTHEAST WINDS LESS THAN 15 KNOTS AND SEAS 2 FEET OF LESS WILL CONTINUE INTO NEXT WEEK AS HIGH PRESSURE OVER THE ATLANTIC RIDGES WEST OVER THE FLORIDA PENINSULA. THE SEA BREEZE WILL SET UP ALONG THE COASTLINE EACH DAY TURNING THE WINDS TO AN ONSHORE FLOW OUT OF THE SOUTHWEST THROUGH NORTHWEST DIRECTION. SCATTERED SHOWERS AND STORMS WILL BE POSSIBLE EACH DAY DEVELOPING OVER LAND AND THEN PUSHING WESTWARD OVER THE COASTAL WATERS DURING THE EVENING HOURS. THE ONLY EXPECTED HAZARD WILL BE GUSTY WINDS AND HIGHER SEAS IN THE VICINITY OF THUNDERSTORMS. && .PRELIMINARY POINT TEMPS/POPS... TPA 91 76 91 76 / 50 30 40 30 FMY 93 74 91 74 / 50 10 50 20 GIF 93 74 92 74 / 40 10 40 10 SRQ 92 75 91 73 / 50 30 50 30 BKV 93 72 93 71 / 50 20 40 30 SPG 92 79 90 78 / 50 30 40 30 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE/AVIATION...MROCZKA MARINE...WYNN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
639 AM CDT TUE SEP 2 2014 ...UPDATED AVIATION SECTION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 357 AM CDT TUE SEP 2 2014 AS OF 0845 UTC, STRONG THUNDERSTORMS WERE UNDERWAY ACROSS COMANCHE, BARBER, AND CLARK COUNTY, TIED MOST CLOSELY TO A ZONE OF FRONTOGENESIS AT AROUND 750MB STRETCHING FROM THE OKLAHOMA PANHANDLE EAST- NORTHEASTWARD TO FAR SOUTH-CENTRAL KANSAS. THE HIRES CONVECTIVE- ALLOWING MODELS PICKED UP ON THIS QUITE WELL IN THE COMPOSITE REFLECTIVITY AND QPF FIELDS. THESE MODELS SHOW THE CONVECTION MOVING OFF INTO NORTHERN OKLAHOMA BEFORE 1200 UTC, SO WE WILL TAPER THE POPS DOWN AROUND THIS TIME. EARLIER IN THE SHIFT, WE ADDED SOME AREAS OF 1/2SM FOG GENERALLY ALONG/SOUTH OF THE ARKANSAS RIVER IN A ZONE OF SATURATED SURFACE AIR NORTH OF THE WEAK SURFACE LOW. ANY FOG WHICH DEVELOPS SHOULD ERODE NOT TOO LONG AFTER SUNRISE, HOWEVER LOW STRATUS IS EXPECTED TO HOLD ON THROUGH LATE MORNING NORTH OF THE 850MB LOW. THIS MAY THROW A BIT OF A CURVE BALL IN THE TEMPERATURES TODAY, SO WE ADJUSTED THEM DOWN (USING A MODIFIED HRRR SOLUTION) OUT ACROSS THE WESTERN HALF FOR THE FIRST HALF OF THE DAY WITH CLOUDS KEEPING A LID IN THE WARM- UP. ONCE THE CLOUDS ERODE COMPLETELY BY MIDDAY/EARLY AFTERNOON, TEMPERATURES WILL WARM INTO THE MID 80S. ANY SURFACE-BASED CONVECTION LATE THIS AFTERNOON WILL BE DOWN ALONG THE SURFACE FRONT ACROSS NORTHWEST OKLAHOMA. BY EARLY EVENING, SOME OF THE THUNDERSTORM ACTIVITY MAY HEAD UP INTO BARBER COUNTY AND EXPAND IN COVERAGE SOME AS LOW LEVEL JET STRENGTHENS AFTER SUNSET. RICH LOW LEVEL MOISTURE LEADING TO 2000-3000 J/KG MOST-UNSTABLE CAPE WILL SUPPORT RENEWED SEVERE WEATHER RISK, EVEN WITH ELEVATED STORMS DURING THE LATE NIGHT HOURS TONIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 326 AM CDT TUE SEP 2 2014 THE LONGWAVE SYNOPTIC FLOW PATTERN WILL BE SOMEWHAT PROGRESSIVE THROUGH THIS FORECAST, AT LEAST ENOUGH TO BRING SIGNIFICANT SENSIBLE WEATHER CHANGES TO THE AREA FOR LATE IN THE WEEK. WEDNESDAY AND THURSDAY WILL SEE SUNNY AND VERY WARM TO HOT TEMPERATURES, AS THE UPPER JET LIFTS NORTHWARD ACROSS THE NORTHERN TIER OF STATES ALLOWING THE LARGE SOUTHERN ROCKIES/SOUTHERN PLAINS HIGH PROVIDE STRONG SUBSIDENCE, FULL INSOLATION AND SOUTHERLY SURFACE WINDS. THE ECMWF/GFS AND NAM ARE IN EXCELLENT AGREEMENT IN BREAKING DOWN THIS PATTERN BY THURSDAY AND BRINGING A COLD FRONT THROUGH THE NORTHERN PLAINS OF WESTERN NEBRASKA AND AS FAR SOUTH AS WEST CENTRAL KANSAS WITH THE LEADING COOLER AIR SURGE BY THURSDAY AFTERNOON. CONVECTION COULD OCCUR LATE THURSDAY AFTERNOON OR EVENING AS WELL WITH THIS COLD FRONT FEATURE, BUT UPPER SUPPORT/DYNAMICS FOR WIDESPREAD STORM DEVELOPMENT IS LACKING. THE UPPER JET WILL SINK SOUTHWARD THROUGH THE CENTRAL PLAINS AND CENTRAL MISSISSIPPI VALLEY, DRIVING THE COLD FRONT FARTHER SOUTH INTO THE SOUTHERN PLAINS BY SATURDAY MORNING. THE RESULT WILL BE ADDITONAL CHANCES FOR POSSIBLY EVEN SEVERE STORMS, BUT PERHAPS JUST POST SURFACE FRONTAL HIGH BASED CONVECTION FROM MID LEVEL FRONTOGENESIS FRIDAY OR FRIDAY NIGHT WITH MUCH MORE PLEASANT TEMPERATURES IN THE 70S. A SLOW WARMING TREND IS LIKELY THROUGH THE LATE PART OF THE WEEKEND INTO EARLY NEXT WEEK AS RETURN SOUTHERLY FLOW BECOMES REESTABLISHED. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 637 AM CDT TUE SEP 2 2014 IFR FOG IS STILL POSSIBLE THROUGH AROUND 14 UTC BEFORE INSOLATION BEGINS TO STRONGLY WARM THE BOUNDARY LAYER THROUGH THE CLOUD LAYER. VISIBILITY HAS ALREADY FLUCTUATED AROUND 2 MILES AT GCK AND DDC SINCE ABOUT 9 Z. THUNDERSTORMS SHOULD NO LONGER BE A THREAT TOT HE TERMINALS THIS MORNING. LIGHT SOUTHEAST WINDS WILL PREVAIL THROUGH THE AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... DDC 87 68 98 71 / 20 10 0 0 GCK 87 67 100 71 / 10 10 0 10 EHA 87 66 99 69 / 10 0 10 10 LBL 87 69 100 72 / 10 10 0 10 HYS 86 67 99 73 / 10 10 10 10 P28 90 72 98 74 / 40 30 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...UMSCHEID LONG TERM...RUSSELL AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS JACKSON KY
948 AM EDT TUE SEP 2 2014 .UPDATE... ISSUED AT 948 AM EDT TUE SEP 2 2014 THE FORECAST FOR THIS AFTERNOON HAS BECOME COMPLICATED BY THE REMNANTS OF AN MCS OVER THE OHIO VALLEY AND THE OUTFLOW BOUNDARY WHICH IS CURRENTLY MOVING INTO THE BLUEGRASS. CURRENT THINKING IS THAT THE OUTFLOW BOUNDARY WILL GENERALLY WEAKEN AS IT CONTINUES MOVING TO THE SOUTHEAST. THIS SHOULD BE TEMPORARY AND WILL THEN BE THE FOCUS OF DEVELOPMENT LATER IN THE AFTERNOON. SO PRETTY MUCH GOING WITH TWO PRONGS. THE FIRST BEING REDEVELOPMENT WITH THE OUTFLOW BOUNDARY AND THE SECOND BEING THE PREFRONTAL ACTIVITY. THE SEVERE THREAT TODAY WILL BE EFFECTED BY HOW MUCH DEBRIS CLOUD IS ABLE TO MOVE INTO THE AREA. THE LOW LEVEL INSTABILITY WILL BE EFFECTED BY EFFECTED BY THE CLOUDS. THE LATEST NAM BUFFER HAS REALLY BACKED OFF FROM YESTERDAY WITH HALF THE CAPE THAN WHAT WAS FORECAST YESTERDAY. ALSO MISSING IS THE DRY AIR POCKETS ALOFT WHICH WOULD HAVE BEEN HELPFUL FOR WET MICROBURSTS TO OCCUR. CAN NOT RULE OUT SEVERE THUNDERSTORMS...HOWEVER THE CHANCES HAVE GONE DOWN. MOST LIKELY WILL STILL SEE A COUPLE OF SEVERE STORMS WITH THIS SYSTEM. UPDATED THE FORECAST TO REFLECT THE CURRENT CONDITIONS AND MODEL TRENDS. UPDATE ISSUED AT 649 AM EDT TUE SEP 2 2014 NO SIGNIFICANT CHANGES MADE THIS MORNING. LINE OF SHOWERS AND STORMS EXTENDS FROM CINCINNATI SOUTHWEST TO THE NORTHWEST SIDE OF LOUISVILLE. THIS LINE CONTINUES TO SLOWLY WEAKEN AS IT MOVES EAST. IF IT WERE TO HOLD TOGETHER...LOOKS LIKE IT MAY WORK INTO THE BLUEGRASS COUNTIES AFTER 13Z. HOWEVER...GIVEN THE TREND THIS SEEMS UNLIKELY AND AT BEST PERHAPS AN ISOLATED SHOWER CAN HOLD TOGETHER. MAIN CONCERN CONTINUES TO BE LATER TODAY...PRIMARILY AFTER 2 PM AS OUTFLOW FROM THIS MORNINGS CONVECTION REDEVELOPS SHOWERS AND STORMS. NOT SURE THE COVERAGE WILL BE ALL THAT GREAT AFTER LOOKING AT THE LATEST HRRR AND NEW 06Z MAV GUIDANCE. BOTH OF THESE MODELS HAVE BACKED OFF SIGNIFICANTLY ON THE CHANCES OF RAIN TODAY. HOWEVER...GOING TO STAY THE COURSE AS THE TROUGH IS STILL FAIRLY DEFINED AND OUTFLOW HAS ALREADY DEFINED A BOUNDARY FOR NEW CONVECTION TO DEVELOP. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 330 AM EDT TUE SEP 2 2014 PRESENTLY...A SHORTWAVE TROUGH IS PUSHING INTO THE OHIO RIVER VALLEY REGION. AN MCS DEVELOPED YESTERDAY EVENING HEAD OF THIS TROUGH AND IS NOW MARCHING EASTWARD INTO CENTRAL/SOUTHERN INDIANA...STRETCHING BACK TO THE SOUTHWEST ACROSS SOUTHERN ILLINOIS. IR SATELLITE HAS SHOWN SOME WARMING WITH THE CLOUD TOPS OVER THE PAST HOUR OR TWO...INDICATING THAT THIS MCS MAY ALREADY BE ON THE DECLINE. IN FACT...THE HRRR SUPPORTS THE IDEA OF A DYING MCS AS IT TRIES TO PUSH INTO CENTRAL KENTUCKY TOWARDS DAYBREAK. CANNOT RULE OUT A FEW SHOWERS PUSHING INTO THE BLUEGRASS SHORTLY AFTER 8 AM...BUT ANTICIPATE MORE OF THE ACTION WITH THE SHORTWAVE TROUGH WILL COME LATER THIS AFTERNOON AS WE GENERATE SOME INSTABILITY. WITH THIS IN MIND...PLAN TO BACK OFF THE POPS THROUGH MIDDAY WITH JUST SOME ISOLATED SHOWERS FOR AREAS NORTH OF I-64. OUTFLOW FROM THE DYING MCS WILL BE PUSHING ACROSS EASTERN KENTUCKY EARLY THIS AFTERNOON...AND COULD KICK START THE CONVECTION AS IT ENCOUNTERS SOME DECENT INSTABILITY. THE FORCING ALOFT SHOULD ALLOW FOR FAIRLY GOOD SHOWER AND THUNDERSTORM COVERAGE BY MID TO LATE AFTERNOON. WITH BULK SHEAR VALUES OF 30-40KTS THIS AFTERNOON...A SEVERE THREAT WOULD EXIST AS THUNDERSTORMS COULD PUT OUT SOME DAMAGING WIND GUSTS. THE SHEAR PROFILES WEAKEN BY MID EVENING AND THE LOSS OF DAYTIME INSTABILITY SHOULD YIELD WEAKENING STORMS AFTER 6 PM. HOWEVER...A FEW GUSTY WINDS MAY STILL BE POSSIBLE THROUGH 8 OR 9 PM. THE SHORTWAVE TROUGH WILL STALL A COLD FRONT ACROSS SOUTHERN KENTUCKY BY LATE THIS EVENING. GIVEN THE PRESENCE OF THIS BOUNDARY...AND PLENTY OF MOISTURE...IT MAY BE POSSIBLE TO SEE ISOLATED SHOWERS THROUGH THE NIGHT ACROSS THE SOUTHERN HALF OF KENTUCKY. THIS BOUNDARY WILL LINGER AROUND INTO WEDNESDAY AND WITH INSTABILITY AGAIN RAMPING UP DURING THE AFTERNOON...WE COULD BE LOOKING AT A FEW MORE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. HOWEVER...BY WEDNESDAY...VERY LITTLE SHEAR IS PRESENT...SO WE SHOULD SEE MORE ORDINARY THUNDERSTORMS WITH NO SEVERE THREAT. TEMPERATURES OVER THE NEXT 2 DAYS SHOULD BE FAIRLY SIMILAR TO WHAT WE HAVE SEEN LATELY WITH HIGHS INTO THE LOW TO MID 80S. SAME CAN BE SAID FOR LOWS TONIGHT WITH READINGS GENERALLY AROUND 70. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 418 AM EDT TUE SEP 2 2014 THE FRONTAL BOUNDARY REFERENCED IN THE SHORT TERM WILL BE DISSOLVING EARLY IN THE LONG TERM PERIOD...BUT THERE SHOULD STILL BE DRY AIR IN PLACE WEDNESDAY NIGHT...ESPECIALLY ALOFT. IF ANY CONVECTIVE PRECIP CAN DEVELOP OFF OF LOW LEVEL MOISTURE ON WEDNESDAY AFTERNOON...IT SHOULD DIE OUT BY NIGHT AS HEATING IS LOST AND SUPPORT ALOFT WILL LIKELY BE LACKING. DEEPER MOISTURE WILL MAKE A COMEBACK LATE IN THE WEEK AND MAY FUEL A RESURGENCE OF SHOWERS AND THUNDERSTORMS...BUT A SUBTROPICAL RIDGE ALOFT OVER THE SE CONUS WILL HELP TO KEEP COVERAGE LIMITED FOR A WHILE. THE RIDGE WILL WEAKEN AND GET SUPPRESSED BY A BROAD TROUGH DROPPING SE INTO THE NE CONUS DURING THE WEEKEND. THIS WILL ALLOW A COLD FRONT TO MOVE INTO OUR REGION FROM THE NW. THE SCENARIO WILL ALLOW AN INCREASE IN PRECIP COVERAGE...WITH A PEAK EXPECTED ON SATURDAY. EVEN THOUGH THE FRONT SHOULD PASS BY SUNDAY...THE MODELS STILL LEAVE SOME QUESTION AS TO HOW EFFECTIVE THE FRONT WILL BE AT BRINGING IN A DRIER AIR MASS. HAVE HELD ONTO LOW POPS IN THE AFTERNOON AND EVENING ON SUNDAY AND MONDAY...ESPECIALLY IN OUR SE COUNTIES. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 649 AM EDT TUE SEP 2 2014 MAINLY VFR CONDITIONS ARE EXPECTED AT THE TAF SITES OVER THE NEXT 24 TO 36 HOURS. A COLD FRONT WILL DROP SOUTH INTO EASTERN KENTUCKY TODAY AND COULD SPAWN SCATTERED TO NUMEROUS THUNDERSTORMS THIS AFTERNOON. PLAN TO STICK WITH THE VCTS THIS AFTERNOON AS TIMING...COVERAGE...AND UNCERTAINTY ARE TOO GREAT TO GO WITH A THUNDERSTORM PREVAILING GROUP. ACTIVITY SHOULD WANE BY MID TO LATE EVENING WITH A QUIET NIGHT EXPECTED TONIGHT. HOWEVER...AS SKIES CLEAR AND CALM WINDS...WE SHOULD SET THE STAGE FOR BETTER FOG PRODUCTION TONIGHT...ESPECIALLY IF WE GET ANY RAIN TODAY. THUS...WILL TAKE AIRPORTS BELOW MINIMUMS LATE TONIGHT WITH THE FOG. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJ SHORT TERM...KAS LONG TERM...HAL AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
649 AM EDT TUE SEP 2 2014 .UPDATE... ISSUED AT 649 AM EDT TUE SEP 2 2014 NO SIGNIFICANT CHANGES MADE THIS MORNING. LINE OF SHOWERS AND STORMS EXTENDS FROM CINCINNATI SOUTHWEST TO THE NORTHWEST SIDE OF LOUISVILLE. THIS LINE CONTINUES TO SLOWLY WEAKEN AS IT MOVES EAST. IF IT WERE TO HOLD TOGETHER...LOOKS LIKE IT MAY WORK INTO THE BLUEGRASS COUNTIES AFTER 13Z. HOWEVER...GIVEN THE TREND THIS SEEMS UNLIKELY AND AT BEST PERHAPS AN ISOLATED SHOWER CAN HOLD TOGETHER. MAIN CONCERN CONTINUES TO BE LATER TODAY...PRIMARILY AFTER 2 PM AS OUTFLOW FROM THIS MORNINGS CONVECTION REDEVELOPS SHOWERS AND STORMS. NOT SURE THE COVERAGE WILL BE ALL THAT GREAT AFTER LOOKING AT THE LATEST HRRR AND NEW 06Z MAV GUIDANCE. BOTH OF THESE MODELS HAVE BACKED OFF SIGNIFICANTLY ON THE CHANCES OF RAIN TODAY. HOWEVER...GOING TO STAY THE COURSE AS THE TROUGH IS STILL FAIRLY DEFINED AND OUTFLOW HAS ALREADY DEFINED A BOUNDARY FOR NEW CONVECTION TO DEVELOP. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 330 AM EDT TUE SEP 2 2014 PRESENTLY...A SHORTWAVE TROUGH IS PUSHING INTO THE OHIO RIVER VALLEY REGION. AN MCS DEVELOPED YESTERDAY EVENING HEAD OF THIS TROUGH AND IS NOW MARCHING EASTWARD INTO CENTRAL/SOUTHERN INDIANA...STRETCHING BACK TO THE SOUTHWEST ACROSS SOUTHERN ILLINOIS. IR SATELLITE HAS SHOWN SOME WARMING WITH THE CLOUD TOPS OVER THE PAST HOUR OR TWO...INDICATING THAT THIS MCS MAY ALREADY BE ON THE DECLINE. IN FACT...THE HRRR SUPPORTS THE IDEA OF A DYING MCS AS IT TRIES TO PUSH INTO CENTRAL KENTUCKY TOWARDS DAYBREAK. CANNOT RULE OUT A FEW SHOWERS PUSHING INTO THE BLUEGRASS SHORTLY AFTER 8 AM...BUT ANTICIPATE MORE OF THE ACTION WITH THE SHORTWAVE TROUGH WILL COME LATER THIS AFTERNOON AS WE GENERATE SOME INSTABILITY. WITH THIS IN MIND...PLAN TO BACK OFF THE POPS THROUGH MIDDAY WITH JUST SOME ISOLATED SHOWERS FOR AREAS NORTH OF I-64. OUTFLOW FROM THE DYING MCS WILL BE PUSHING ACROSS EASTERN KENTUCKY EARLY THIS AFTERNOON...AND COULD KICK START THE CONVECTION AS IT ENCOUNTERS SOME DECENT INSTABILITY. THE FORCING ALOFT SHOULD ALLOW FOR FAIRLY GOOD SHOWER AND THUNDERSTORM COVERAGE BY MID TO LATE AFTERNOON. WITH BULK SHEAR VALUES OF 30-40KTS THIS AFTERNOON...A SEVERE THREAT WOULD EXIST AS THUNDERSTORMS COULD PUT OUT SOME DAMAGING WIND GUSTS. THE SHEAR PROFILES WEAKEN BY MID EVENING AND THE LOSS OF DAYTIME INSTABILITY SHOULD YIELD WEAKENING STORMS AFTER 6 PM. HOWEVER...A FEW GUSTY WINDS MAY STILL BE POSSIBLE THROUGH 8 OR 9 PM. THE SHORTWAVE TROUGH WILL STALL A COLD FRONT ACROSS SOUTHERN KENTUCKY BY LATE THIS EVENING. GIVEN THE PRESENCE OF THIS BOUNDARY...AND PLENTY OF MOISTURE...IT MAY BE POSSIBLE TO SEE ISOLATED SHOWERS THROUGH THE NIGHT ACROSS THE SOUTHERN HALF OF KENTUCKY. THIS BOUNDARY WILL LINGER AROUND INTO WEDNESDAY AND WITH INSTABILITY AGAIN RAMPING UP DURING THE AFTERNOON...WE COULD BE LOOKING AT A FEW MORE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. HOWEVER...BY WEDNESDAY...VERY LITTLE SHEAR IS PRESENT...SO WE SHOULD SEE MORE ORDINARY THUNDERSTORMS WITH NO SEVERE THREAT. TEMPERATURES OVER THE NEXT 2 DAYS SHOULD BE FAIRLY SIMILAR TO WHAT WE HAVE SEEN LATELY WITH HIGHS INTO THE LOW TO MID 80S. SAME CAN BE SAID FOR LOWS TONIGHT WITH READINGS GENERALLY AROUND 70. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 418 AM EDT TUE SEP 2 2014 THE FRONTAL BOUNDARY REFERENCED IN THE SHORT TERM WILL BE DISSOLVING EARLY IN THE LONG TERM PERIOD...BUT THERE SHOULD STILL BE DRY AIR IN PLACE WEDNESDAY NIGHT...ESPECIALLY ALOFT. IF ANY CONVECTIVE PRECIP CAN DEVELOP OFF OF LOW LEVEL MOISTURE ON WEDNESDAY AFTERNOON...IT SHOULD DIE OUT BY NIGHT AS HEATING IS LOST AND SUPPORT ALOFT WILL LIKELY BE LACKING. DEEPER MOISTURE WILL MAKE A COMEBACK LATE IN THE WEEK AND MAY FUEL A RESURGENCE OF SHOWERS AND THUNDERSTORMS...BUT A SUBTROPICAL RIDGE ALOFT OVER THE SE CONUS WILL HELP TO KEEP COVERAGE LIMITED FOR A WHILE. THE RIDGE WILL WEAKEN AND GET SUPPRESSED BY A BROAD TROUGH DROPPING SE INTO THE NE CONUS DURING THE WEEKEND. THIS WILL ALLOW A COLD FRONT TO MOVE INTO OUR REGION FROM THE NW. THE SCENARIO WILL ALLOW AN INCREASE IN PRECIP COVERAGE...WITH A PEAK EXPECTED ON SATURDAY. EVEN THOUGH THE FRONT SHOULD PASS BY SUNDAY...THE MODELS STILL LEAVE SOME QUESTION AS TO HOW EFFECTIVE THE FRONT WILL BE AT BRINGING IN A DRIER AIR MASS. HAVE HELD ONTO LOW POPS IN THE AFTERNOON AND EVENING ON SUNDAY AND MONDAY...ESPECIALLY IN OUR SE COUNTIES. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 649 AM EDT TUE SEP 2 2014 MAINLY VFR CONDITIONS ARE EXPECTED AT THE TAF SITES OVER THE NEXT 24 TO 36 HOURS. A COLD FRONT WILL DROP SOUTH INTO EASTERN KENTUCKY TODAY AND COULD SPAWN SCATTERED TO NUMEROUS THUNDERSTORMS THIS AFTERNOON. PLAN TO STICK WITH THE VCTS THIS AFTERNOON AS TIMING...COVERAGE...AND UNCERTAINTY ARE TOO GREAT TO GO WITH A THUNDERSTORM PREVAILING GROUP. ACTIVITY SHOULD WANE BY MID TO LATE EVENING WITH A QUIET NIGHT EXPECTED TONIGHT. HOWEVER...AS SKIES CLEAR AND CALM WINDS...WE SHOULD SET THE STAGE FOR BETTER FOG PRODUCTION TONIGHT...ESPECIALLY IF WE GET ANY RAIN TODAY. THUS...WILL TAKE AIRPORTS BELOW MINIMUMS LATE TONIGHT WITH THE FOG. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...KAS LONG TERM...HAL AVIATION...KAS
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1045 AM EDT TUE SEP 2 2014 .UPDATE... ISSUED AT 1044 AM EDT TUE SEP 2 2014 LIMITED CHANGES TO THE GOING FORECAST. MAIN CHANGE WAS TO THE THICKNESS OF THE MID-HIGH CLOUDS STREAMING NORTHEAST ACROSS THE AREA THIS MORNING AND HAVE BUMPED THE FORECAST UP TO MOSTLY CLOUDY OVER THE CENTRAL U.P. AS THIS MOVES THROUGH. DO HAVE SOME CONCERN ON THE IMPACT THE CLOUDS WILL HAVE ON DIURNAL HEATING TODAY AND IN TURN SHOWERS DEVELOPING THIS AFTERNOON. HAVE NOTICED A TREND IN THE HIGH-RES MODELS (HRRR...NAMDNG...AND OUR LOCAL WRF-ARW) TO DEVELOP THE SHOWERS A LITTLE FARTHER TO THE EAST (GENERALLY EASTERN MARQUETTE/MENOMINEE COUNTIES AND EASTWARD)...AND HAVE ADJUSTED THE POPS SLIGHTLY TOWARDS THAT IDEA. THE EASTERN U.P. STILL LOOKS TO HAVE THE BEST CHANCES DUE TO LAKE BREEZE CONVERGENCE AND STORM MOTION VECTORS PUSHING SHOWERS EASTWARD. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 500 AM EDT TUE SEP 2 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD LOW AMPLITUDE MID/UPPER LEVEL TROUGH THROUGH FROM THE NRN PLAINS INTO THE UPPER MS VALLEY AND WRN GREAT LAKES WITH SEVERAL WEAK EMBEDDED SHORTWAVES. ONE WAS LOCATED FROM SW MN INTO NW IA WHILE ANOTHER UPSTREAM SHRTWV WAS MOVING THROUGH NORTH DAKOTA. AT THE SFC...WRLY FLOW PREVAILED ACROSS UPPER MI BETWEEN A 987 MB LOW NEAR JAMES BAY AND A WEAK RIDGE INTO THE CNTRL PLAINS.IR LOOP SHOWED MAINLY CLEAR SKIES ACROSS MOST OF THE CWA BUT WITH INCREASING CLOUDS FROM MN INTO NW WI AND WRN UPPER MI AHEAD OF THE SW MN SHRTWV. TODAY...MOST OF THE FORCING ASSOCIATED WITH THE MN SHRTWV IS EXPECTED TO REMAIN SOUTH OF UPPER MI. HOWEVER...THE COMBINATION OF DAYTIME HEATING AND 850-600 MB LAPSE RATES TO NEAR 7.5C/KM AND LOW LEVEL CONV ALONG LAKE BREEZE BOUNDARIES(ESPECIALLY OVER THE EAST) WILL SUPPORT ISOLD/SCT SHRA BY THIS AFTERNOON. AS THE NORTH DAKOTA SHRTWV NEAR BY MID TO LATE AFTERNOON SOME ADDITIONAL WEAK QVECTOR CONV MAY ALSO CONTRIBUTE TO PCPN CHANCES. ALTHOUGH MLCAPE VALUES INTO THE 400-800 J/KG RANGE WILL BE MARGINAL FOR TS...SOME ISOLD COULD DEVELOP. WITH FREEZING HEIGHTS ONLY NEAR 9K-10K FT...SOME SMALL HAIL MAY BE POSSIBLE. TONIGHT...WITH THE LOSS OF DAYTIME HEATING AND THE SHRTWVS EXITING TO THE EAST...ANY PCPN SHOULD QUICKLY DIMINISH. WITH THE FAST MID/UPPER LEVEL FLOW ACROSS THE NRN CONUS...MODELS SUGGEST THAT ANOTHER WEAK SHRTWV COULD MOVE THROUGH THE NRN LAKES AND PRODUCE SOME LIGHT PCPN. HOWEVER...WITH VERY LIMITED MOISTURE AND LITTLE INSTABILITY...CONFIDENCE IN ADDITIONAL PCPN DEVELOPING WAS LOW AND NO ADDITIONAL RAIN WAS MENTIONED. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 401 AM EDT TUE SEP 2 2014 THOUGH ACTIVE WEDNESDAY NIGHT INTO THURSDAY EVENING...THE REST OF LONG TERM WILL BE QUIET AS HIGH PRESSURE DOMINATES FROM FRIDAY INTO EARLY NEXT WEEK. STARTING ON WEDNESDAY...WEAKER SHORTWAVES WORK THEIR WAY ACROSS NORTHERN PLAINS AND TO UPPER GREAT LAKES BY LATE IN THE DAY IN A ZONAL FLOW PATTERN ALOFT. LARGE SCALE LIFT IS PRESENT BUT THERE IS NOT MUCH FOR A STRONGER SHORTWAVE AND ALSO OVERALL MOISTURE IS LIMITED. BULK OF SHRA/TSRA LATER ON WEDNESDAY SHOULD STAY WEST OF UPR MICHIGAN...MAINLY OVER CENTRAL AND SOUTHERN MINNESOTA CLOSER TO SFC WARM FRONT AND BUILDING INSTABILITY. COULD SEE ISOLD SHRA/TSRA OVER WESTERN LK SUPERIOR OR EVEN FAR WEST UPR MICHIGAN DUE TO GENERAL H85-H7 WARM AIR ADVECTION AND MID-LEVEL MOISTURE ADVECTION. TEMPS ON WEDNESDAY SHOULD PUSH INTO THE UPPER 70S OR LOWER 80S EVEN WITH SCT-BKN MID CLOUDS IN THE AFTN. POTENTIAL FOR PERIOD OF ACTIVE WEATHER WEDNESDAY NIGHT INTO THURSDAY MORNING AS THE APPROACH OF A SFC LOW OVER THE NORTHERN PLAINS INCREASES LOW-LEVEL JET /40 KTS AT H85/ INTO THE UPPER GREAT LAKES. SINCE THERE IS NOT REALLY A STRONG SHORTWAVE MOVING THROUGH AT THAT TIME THOUGH...THINK THAT THE BULK OF SHRA/TSRA WILL BE VCNTY OF WHERE LOW- LEVEL JET INTERSECTS THE SFC-H85 WARM FRONT. BASED ON SFC WINDS AND DWPNTS...BEST GUESS AT LOCATION OF THAT BOUNDARY IS FM CNTRL MN INTO WESTERN WI WEDNESDAY NIGHT. MAX INSTABILITY BOTH IN TERMS OF MLCAPE AND ELEVATED MUCAPE WILL BE MAXIMIZED OVER MUCH OF MINNESOTA AND INTO WISCONSIN WITH INSTABILITY TRAILING OFF CONSIDERABLY INTO UPR MICHIGAN AND LK MICHIGAN/LOWER MICHIGAN. MAJORITY OF MODELS INDICATE WIDESPREAD QPF OVER UPR MICHIGAN WEDNESDAY NIGHT...BUT HAVE MY DOUBTS ON THIS AS MOST OF THE HEAVY SHRA/TSRA COULD END UP FARTHER SOUTH ALONG WARM FRONT AND ALSO BASED ON H85-H3 THICKNESSES WHICH...ALONG WITH FORWARD PROPAGATING CORFIDI VECTORS...CAN BE USED TO DETERMINE GENERAL MOTION OF AN MCS. SIMILAR TO EARLIER IN THE NIGHT...THERE IS STILL MID-LEVEL MOISTURE ADVECTION FARTHER NORTH OF THE BOUNDARY THOUGH SO CANNOT COMPLETELY RULE OUT SHRA/TSRA MAKING IT ACROSS UPR MICHIGAN. ANOTHER FACTOR THAT COULD BUMP SHRA/TSRA FARTHER NORTH INTO THE CWA IS INCREASING CAPPING THAT DEVELOPS IN THE H8-H7 LAYER OUT AHEAD OF THE SFC LOW. AT THIS POINT THOUGH IT APPEARS THAT MAIN EXTENT OF CAPPING WILL REMAIN BACK OVER THE CENTRAL PLAINS ON WEDNESDAY NIGHT. GIVEN THE CONCERNS ABOUT TSRA OVERAGE...BACKED DOWN A BIT ON THE HIGHER POPS WE HAD GOING BUT DID KEEP POPS HIGH CHANCE TO LOW END LIKELY WITH BETTER CHANCES OVER THE WEST INITIALLY SHIFTING TO THE EAST FOLLOWING THE TREND OF H7-H5 Q-VECTOR CONVERGENCE TIED TO INITIAL WEAK SHORTWAVE AND ALSO WHERE THIS FORCING SYNCS UP WITH GREATER MID-LEVEL MOISTURE TRANSPORT. TSRA INTENSITY SHOULD DIMINISH INTO THE EAST BY LATE WED NIGHT INTO THURSDAY MORNING AS SHRA/TSRA OUTRUN GREATER POOL OF INSTABILITY OVER MINNESOTA AND WISCONSIN. FOR THURSDAY...RETAINED MUCH OF THE PREVIOUS FORECAST SHOWING TREND TOWARD LOWER POPS BY LATE THURSDAY MORNING IN WAKE OF THE INITIAL SHRA/TSRA MOVING EAST THEN POPS RAMPING BACK UP IN THE AFTN WITH POSSIBLE ADDITIONAL SHRA/TSRA AHEAD OF APPROACHING COLD FRONT. CAPPING SHOULD INCREASE MARKEDLY BY LATE MORNING/EARLY AFTN BASED ON FORECAST SOUNDINGS SO THIS WILL IMPACT ADDITIONAL DEVELOPMENT OF SHRA/TSRA. COULD GET QUITE WARM WITH EVEN JUST A LITTLE CLEARING. MIXING TO H9 WITH SHARPER INVERSION AROUND THAT LEVEL SHOWN ON SOUNDINGS MAY BE CONSERVATIVE BUT STILL RESULTS IN HIGHS AROUND 80 OVER MUCH OF CWA. NUDGED TEMPS UP INTO THE LOWER 80S AS A STARTING POINT...BUT A MUGGY DAY /SFC DWPNTS 65-70/ WITH MID 80S IS CERTAINLY POSSIBLE IN SOME AREAS. PRIMARY SHORTWAVE DRIVING THE COLD FRONT WILL BE JUST NORTH OF MINNESOTA BY LATE THURSDAY AFTN. GIVEN THE WARM AND HUMID AIRMASS...MLCAPES AHEAD OF THE FRONT OVER WEST HALF OF CWA COULD PUSH OVER 2500J/KG...BUT MAIN QUESTIONS ARE HOW MUCH DEEPER MOISTURE WILL BE AROUND AHEAD OF THE FRONT AND WILL CAPPING IN THE H8-H7 LAYER BE TOO STRONG TO PROHIBIT SHRA/TSRA FROM DEVELOPING? BASED ON CONSENSUS OF MODELS AND LATEST TRENDS...SEEMS THAT THERE IS A RISK OF STORMS FORMING MID-LATE THURSDAY AFTN OVER THE WEST AND AFFECTING REST OF CWA INTO THE EARLY EVENING AS BETTER MOISTURE IS RE-INTRODUCED INTO THE AREA FM THE WEST/SOUTHWEST AND LIFT INCREASES AND CAPPING DECREASES AS SHORTWAVE AND H5 SPEED MAX DRAW CLOSER. GIVEN THE DEGREE OF INSTABILITY...IF STORMS FORM...SEVERE WEATHER POTENTIAL IS ELEVATED AS 0-6KM SHEAR IS OVER 45 KTS AND 0-3KM SHEAR IS OVER 30 KTS. THE FORECASTED INSTABILITY...IF IT IS INDEED REALIZED...AND SUCH SHEAR WOULD SUPPORT ROTATING/SUPERCELL TYPE STORMS AND ALSO POTENTIAL FOR STORMS CONSOLIDATING INTO SEVERE WIND GUST PRODUCING MCS ALONG THE COLD FRONT. A CONDITIONAL RISK ATTM...BUT CERTAINTLY WORTH MONITORING AS WE GET CLOSER TO THIS TIME FRAME. SPC DAY3 OUTLOOK HIGHLIGHTS WI INTO WEST HALF OF UPR MICHIGAN WITH A 15 PCT RISK FOR SEVERE /SLIGHT CATEGORICAL RISK/. WILL MENTION POTENTIAL FOR SEVERE IN THE MORNING HAZARDOUS WEATHER OUTLOOK. ONCE THE COLD FRONT SLIDES THROUGH ON THURSDAY NIGHT...ANY LINGERING SHRA/TSRA WILL QUICKLY COME TO AN END BY THE OVERNIGHT SOUTH AND EAST CWA. MAIN ISSUE LATE THURSDAY NIGHT INTO FRIDAY WILL BE GUSTY NORTHWEST WINDS ON LK SUPERIOR AS IT BECOMES UNSTABLE IN THE 1000-900MB LAYER. MIXED LAYER WINDS ARE OVER 30 KTS SO IT COULD BE GUSTY ALONG THE LK SUPERIOR SHORE TO BEGIN THE DAY ON FRIDAY. DUE TO PRESSURE RISES BTWN DEPARTING LOW AND APPROACHING HIGH...EVEN HIGHER WINDS WOULD NOT BE OUT OF QUESTION. INCREASING WAVE ACTION WOULD ALSO LEAD TO HIGH SWIM RISK ON BEACHES FROM MARQUETTE TO GRAND MARAIS. QUIET WEATHER FOR THE WEEKEND AS IT LOOKS NOW. HIGH PRESSURE SETTLES OVERHEAD AND STAYS IN PLACE INTO EARLY NEXT WEEK. TEMPS AT NIGHT MAY DIP BLO 40 DEGREES IN THE INTERIOR. DAYTIME HIGHS WILL BE SEASONABLY COOL IN THE 60S FOR MOST AREAS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 738 AM EDT TUE SEP 2 2014 EXPECT VFR CONDITIONS TO PREVAIL THIS FCST PERIOD WITH RELATIVELY DRY LOW LEVEL AIR DOMINATING. AN APPROACHING UPPER DISTURBANCE ALONG WITH DAYTIME HEATING AND DESTABILIZATION COULD CAUSE SOME -SHRA AT SAW AND PERHAPS IWD THIS AFTN...BUT THE DRY LOW LEVEL AIR SHOULD MAINTAIN PREDOMINANT VFR WX EVEN IF THE -SHRA OCCUR. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 500 AM EDT TUE SEP 2 2014 WINDS WILL BE 20 KNOTS OR LESS THROUGH MOST OF THIS FORECAST PERIOD EXCEPT FOR THU NIGHT INTO FRI WHEN WEST TO NORTHWEST WINDS BEHIND A STRONG COLD FRONT WILL APPROACH 30 KNOTS. THIS WILL BE THE WHEN THE STRONGEST WINDS OCCUR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...SRF SHORT TERM...JLB LONG TERM...JLA AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
739 AM EDT TUE SEP 2 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 500 AM EDT TUE SEP 2 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD LOW AMPLITUDE MID/UPPER LEVEL TROUGH THROUGH FROM THE NRN PLAINS INTO THE UPPER MS VALLEY AND WRN GREAT LAKES WITH SEVERAL WEAK EMBEDDED SHORTWAVES. ONE WAS LOCATED FROM SW MN INTO NW IA WHILE ANOTHER UPSTREAM SHRTWV WAS MOVING THROUGH NORTH DAKOTA. AT THE SFC...WRLY FLOW PREVAILED ACROSS UPPER MI BETWEEN A 987 MB LOW NEAR JAMES BAY AND A WEAK RIDGE INTO THE CNTRL PLAINS.IR LOOP SHOWED MAINLY CLEAR SKIES ACROSS MOST OF THE CWA BUT WITH INCREASING CLOUDS FROM MN INTO NW WI AND WRN UPPER MI AHEAD OF THE SW MN SHRTWV. TODAY...MOST OF THE FORCING ASSOCIATED WITH THE MN SHRTWV IS EXPECTED TO REMAIN SOUTH OF UPPER MI. HOWEVER...THE COMBINATION OF DAYTIME HEATING AND 850-600 MB LAPSE RATES TO NEAR 7.5C/KM AND LOW LEVEL CONV ALONG LAKE BREEZE BOUNDARIES(ESPECIALLY OVER THE EAST) WILL SUPPORT ISOLD/SCT SHRA BY THIS AFTERNOON. AS THE NORTH DAKOTA SHRTWV NEAR BY MID TO LATE AFTERNOON SOME ADDITIONAL WEAK QVECTOR CONV MAY ALSO CONTRIBUTE TO PCPN CHANCES. ALTHOUGH MLCAPE VALUES INTO THE 400-800 J/KG RANGE WILL BE MARGINAL FOR TS...SOME ISOLD COULD DEVELOP. WITH FREEZING HEIGHTS ONLY NEAR 9K-10K FT...SOME SMALL HAIL MAY BE POSSIBLE. TONIGHT...WITH THE LOSS OF DAYTIME HEATING AND THE SHRTWVS EXITING TO THE EAST...ANY PCPN SHOULD QUICKLY DIMINISH. WITH THE FAST MID/UPPER LEVEL FLOW ACROSS THE NRN CONUS...MODELS SUGGEST THAT ANOTHER WEAK SHRTWV COULD MOVE THROUGH THE NRN LAKES AND PRODUCE SOME LIGHT PCPN. HOWEVER...WITH VERY LIMITED MOISTURE AND LITTLE INSTABILITY...CONFIDENCE IN ADDITIONAL PCPN DEVELOPING WAS LOW AND NO ADDITIONAL RAIN WAS MENTIONED. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 401 AM EDT TUE SEP 2 2014 THOUGH ACTIVE WEDNESDAY NIGHT INTO THURSDAY EVENING...THE REST OF LONG TERM WILL BE QUIET AS HIGH PRESSURE DOMINATES FROM FRIDAY INTO EARLY NEXT WEEK. STARTING ON WEDNESDAY...WEAKER SHORTWAVES WORK THEIR WAY ACROSS NORTHERN PLAINS AND TO UPPER GREAT LAKES BY LATE IN THE DAY IN A ZONAL FLOW PATTERN ALOFT. LARGE SCALE LIFT IS PRESENT BUT THERE IS NOT MUCH FOR A STRONGER SHORTWAVE AND ALSO OVERALL MOISTURE IS LIMITED. BULK OF SHRA/TSRA LATER ON WEDNESDAY SHOULD STAY WEST OF UPR MICHIGAN...MAINLY OVER CENTRAL AND SOUTHERN MINNESOTA CLOSER TO SFC WARM FRONT AND BUILDING INSTABILITY. COULD SEE ISOLD SHRA/TSRA OVER WESTERN LK SUPERIOR OR EVEN FAR WEST UPR MICHIGAN DUE TO GENERAL H85-H7 WARM AIR ADVECTION AND MID-LEVEL MOISTURE ADVECTION. TEMPS ON WEDNESDAY SHOULD PUSH INTO THE UPPER 70S OR LOWER 80S EVEN WITH SCT-BKN MID CLOUDS IN THE AFTN. POTENTIAL FOR PERIOD OF ACTIVE WEATHER WEDNESDAY NIGHT INTO THURSDAY MORNING AS THE APPROACH OF A SFC LOW OVER THE NORTHERN PLAINS INCREASES LOW-LEVEL JET /40 KTS AT H85/ INTO THE UPPER GREAT LAKES. SINCE THERE IS NOT REALLY A STRONG SHORTWAVE MOVING THROUGH AT THAT TIME THOUGH...THINK THAT THE BULK OF SHRA/TSRA WILL BE VCNTY OF WHERE LOW- LEVEL JET INTERSECTS THE SFC-H85 WARM FRONT. BASED ON SFC WINDS AND DWPNTS...BEST GUESS AT LOCATION OF THAT BOUNDARY IS FM CNTRL MN INTO WESTERN WI WEDNESDAY NIGHT. MAX INSTABILITY BOTH IN TERMS OF MLCAPE AND ELEVATED MUCAPE WILL BE MAXIMIZED OVER MUCH OF MINNESOTA AND INTO WISCONSIN WITH INSTABILITY TRAILING OFF CONSIDERABLY INTO UPR MICHIGAN AND LK MICHIGAN/LOWER MICHIGAN. MAJORITY OF MODELS INDICATE WIDESPREAD QPF OVER UPR MICHIGAN WEDNESDAY NIGHT...BUT HAVE MY DOUBTS ON THIS AS MOST OF THE HEAVY SHRA/TSRA COULD END UP FARTHER SOUTH ALONG WARM FRONT AND ALSO BASED ON H85-H3 THICKNESSES WHICH...ALONG WITH FORWARD PROPAGATING CORFIDI VECTORS...CAN BE USED TO DETERMINE GENERAL MOTION OF AN MCS. SIMILAR TO EARLIER IN THE NIGHT...THERE IS STILL MID-LEVEL MOISTURE ADVECTION FARTHER NORTH OF THE BOUNDARY THOUGH SO CANNOT COMPLETELY RULE OUT SHRA/TSRA MAKING IT ACROSS UPR MICHIGAN. ANOTHER FACTOR THAT COULD BUMP SHRA/TSRA FARTHER NORTH INTO THE CWA IS INCREASING CAPPING THAT DEVELOPS IN THE H8-H7 LAYER OUT AHEAD OF THE SFC LOW. AT THIS POINT THOUGH IT APPEARS THAT MAIN EXTENT OF CAPPING WILL REMAIN BACK OVER THE CENTRAL PLAINS ON WEDNESDAY NIGHT. GIVEN THE CONCERNS ABOUT TSRA OVERAGE...BACKED DOWN A BIT ON THE HIGHER POPS WE HAD GOING BUT DID KEEP POPS HIGH CHANCE TO LOW END LIKELY WITH BETTER CHANCES OVER THE WEST INITIALLY SHIFTING TO THE EAST FOLLOWING THE TREND OF H7-H5 Q-VECTOR CONVERGENCE TIED TO INITIAL WEAK SHORTWAVE AND ALSO WHERE THIS FORCING SYNCS UP WITH GREATER MID-LEVEL MOISTURE TRANSPORT. TSRA INTENSITY SHOULD DIMINISH INTO THE EAST BY LATE WED NIGHT INTO THURSDAY MORNING AS SHRA/TSRA OUTRUN GREATER POOL OF INSTABILITY OVER MINNESOTA AND WISCONSIN. FOR THURSDAY...RETAINED MUCH OF THE PREVIOUS FORECAST SHOWING TREND TOWARD LOWER POPS BY LATE THURSDAY MORNING IN WAKE OF THE INITIAL SHRA/TSRA MOVING EAST THEN POPS RAMPING BACK UP IN THE AFTN WITH POSSIBLE ADDITIONAL SHRA/TSRA AHEAD OF APPROACHING COLD FRONT. CAPPING SHOULD INCREASE MARKEDLY BY LATE MORNING/EARLY AFTN BASED ON FORECAST SOUNDINGS SO THIS WILL IMPACT ADDITIONAL DEVELOPMENT OF SHRA/TSRA. COULD GET QUITE WARM WITH EVEN JUST A LITTLE CLEARING. MIXING TO H9 WITH SHARPER INVERSION AROUND THAT LEVEL SHOWN ON SOUNDINGS MAY BE CONSERVATIVE BUT STILL RESULTS IN HIGHS AROUND 80 OVER MUCH OF CWA. NUDGED TEMPS UP INTO THE LOWER 80S AS A STARTING POINT...BUT A MUGGY DAY /SFC DWPNTS 65-70/ WITH MID 80S IS CERTAINLY POSSIBLE IN SOME AREAS. PRIMARY SHORTWAVE DRIVING THE COLD FRONT WILL BE JUST NORTH OF MINNESOTA BY LATE THURSDAY AFTN. GIVEN THE WARM AND HUMID AIRMASS...MLCAPES AHEAD OF THE FRONT OVER WEST HALF OF CWA COULD PUSH OVER 2500J/KG...BUT MAIN QUESTIONS ARE HOW MUCH DEEPER MOISTURE WILL BE AROUND AHEAD OF THE FRONT AND WILL CAPPING IN THE H8-H7 LAYER BE TOO STRONG TO PROHIBIT SHRA/TSRA FROM DEVELOPING? BASED ON CONSENSUS OF MODELS AND LATEST TRENDS...SEEMS THAT THERE IS A RISK OF STORMS FORMING MID-LATE THURSDAY AFTN OVER THE WEST AND AFFECTING REST OF CWA INTO THE EARLY EVENING AS BETTER MOISTURE IS RE-INTRODUCED INTO THE AREA FM THE WEST/SOUTHWEST AND LIFT INCREASES AND CAPPING DECREASES AS SHORTWAVE AND H5 SPEED MAX DRAW CLOSER. GIVEN THE DEGREE OF INSTABILITY...IF STORMS FORM...SEVERE WEATHER POTENTIAL IS ELEVATED AS 0-6KM SHEAR IS OVER 45 KTS AND 0-3KM SHEAR IS OVER 30 KTS. THE FORECASTED INSTABILITY...IF IT IS INDEED REALIZED...AND SUCH SHEAR WOULD SUPPORT ROTATING/SUPERCELL TYPE STORMS AND ALSO POTENTIAL FOR STORMS CONSOLIDATING INTO SEVERE WIND GUST PRODUCING MCS ALONG THE COLD FRONT. A CONDITIONAL RISK ATTM...BUT CERTAINTLY WORTH MONITORING AS WE GET CLOSER TO THIS TIME FRAME. SPC DAY3 OUTLOOK HIGHLIGHTS WI INTO WEST HALF OF UPR MICHIGAN WITH A 15 PCT RISK FOR SEVERE /SLIGHT CATEGORICAL RISK/. WILL MENTION POTENTIAL FOR SEVERE IN THE MORNING HAZARDOUS WEATHER OUTLOOK. ONCE THE COLD FRONT SLIDES THROUGH ON THURSDAY NIGHT...ANY LINGERING SHRA/TSRA WILL QUICKLY COME TO AN END BY THE OVERNIGHT SOUTH AND EAST CWA. MAIN ISSUE LATE THURSDAY NIGHT INTO FRIDAY WILL BE GUSTY NORTHWEST WINDS ON LK SUPERIOR AS IT BECOMES UNSTABLE IN THE 1000-900MB LAYER. MIXED LAYER WINDS ARE OVER 30 KTS SO IT COULD BE GUSTY ALONG THE LK SUPERIOR SHORE TO BEGIN THE DAY ON FRIDAY. DUE TO PRESSURE RISES BTWN DEPARTING LOW AND APPROACHING HIGH...EVEN HIGHER WINDS WOULD NOT BE OUT OF QUESTION. INCREASING WAVE ACTION WOULD ALSO LEAD TO HIGH SWIM RISK ON BEACHES FROM MARQUETTE TO GRAND MARAIS. QUIET WEATHER FOR THE WEEKEND AS IT LOOKS NOW. HIGH PRESSURE SETTLES OVERHEAD AND STAYS IN PLACE INTO EARLY NEXT WEEK. TEMPS AT NIGHT MAY DIP BLO 40 DEGREES IN THE INTERIOR. DAYTIME HIGHS WILL BE SEASONABLY COOL IN THE 60S FOR MOST AREAS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 738 AM EDT TUE SEP 2 2014 EXPECT VFR CONDITIONS TO PREVAIL THIS FCST PERIOD WITH RELATIVELY DRY LOW LEVEL AIR DOMINATING. AN APPROACHING UPPER DISTURBANCE ALONG WITH DAYTIME HEATING AND DESTABILIZATION COULD CAUSE SOME -SHRA AT SAW AND PERHAPS IWD THIS AFTN...BUT THE DRY LOW LEVEL AIR SHOULD MAINTAIN PREDOMINANT VFR WX EVEN IF THE -SHRA OCCUR. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 500 AM EDT TUE SEP 2 2014 WINDS WILL BE 20 KNOTS OR LESS THROUGH MOST OF THIS FORECAST PERIOD EXCEPT FOR THU NIGHT INTO FRI WHEN WEST TO NORTHWEST WINDS BEHIND A STRONG COLD FRONT WILL APPROACH 30 KNOTS. THIS WILL BE THE WHEN THE STRONGEST WINDS OCCUR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...JLA AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION
NWS JACKSON MS
1052 AM CDT TUE SEP 2 2014 .UPDATE... SOME ADJUSTMENTS WERE MADE TO THE POPS AND QPF FOR THIS AFTERNOON AND EVENING...AND MINOR ADJUSTMENTS WERE MADE TO TEMPERATURES. ALL ELSE IS GENERALLY ON TRACK. && .DISCUSSION...A DIFFICULT FORECAST SCENARIO EXISTS FOR TODAY AS CONVECTIVE OUTFLOW PUSHES SOUTH ACROSS ARKANSAS AND TOWARD NORTHWEST PORTIONS OF THE ARKLAMISS...WHILE THE BEST LOW LEVEL CONVERGENCE SETS UP GENERALLY ALONG THE NATCHEZ TRACE CORRIDOR. THIS PATTERN IS RESULTING IN LOW LEVEL DRY AIR ADVECTION AHEAD OF THE SOUTHWARD MOVING BOUNDARY AND THIS MAY LIMIT CONVECTIVE DEVELOPMENT LATER THIS AFTERNOON OVER PORTIONS OF NORTHEAST LOUISIANA INTO WESTERN MS. HOWEVER...BASED ON THE LATEST HRRR AND LOCAL WRF GUIDANCE...EXPECT CONSIDERABLE SHOWER/TSTM DEVELOPMENT ALONG THE SAID MOIST-CONVERGENCE AXIS WHERE PRECIPITABLE WATER IN EXCESS OF TWO INCHES AND SB CAPE ~3500 J/KG WILL EXIST. LAPSE RATES WILL BE MARGINAL FOR GETTING A FEW SEVERE STORMS. OVERALL... HAVE ADJUSTED POPS TO BETTER REFLECT THE ABOVE SCENARIO... INCREASED THEM EAST AND DECREASED THEM OVER PORTIONS OF THE LA/MS DELTA REGION...BUT THIS IS NOT A HIGH CONFIDENCE FORECAST GIVEN 10-15 KTS OF LOW LEVEL FLOW AND NUMEROUS OUTFLOW BOUNDARIES LIKELY TO EXIST. /EC/ && .AVIATION...CEILINGS WERE SLOWLY LIFTING ACROSS THE REGION...WITH MVFR CONDITIONS AT MOST LOCATIONS. THROUGH NOON...LOOK FOR CEILING TO CONTINUE TO LIFT. SHOWERS WILL REMAIN IN THE VICINITY OF JACKSON GOING INTO THE AFTERNOON. WITH CLOUDS LINGERING OVER THE AREA...NOT SURE HOW MUCH THUNDER WILL BE AROUND...BUT WILL CONTINUE THE VCTS FROM 20-24Z. A BOUNDARY OFF TO NORTHWEST WAS SLOWLY MOVING IN THIS DIRECTION...BUT MODELS SUGGEST IT WILL NOT MAKE IT THIS FAR SOUTH. MODELS SEEM TO DISAGREE ABOUT FOG DEVELOPMENT FOR TONIGHT BUT AGREE STRATUS SHOULD NOT DEVELOP. WILL ADD PATCHY FOG TO ALL SITES FROM 8-12Z. && .PREV DISCUSSION... /ISSUED 351 AM CDT TUE SEP 2 2014/ DISCUSSION... TODAY THROUGH WEDNESDAY GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS EXPECTED TODAY VS. YESTERDAY WITH SOME POSSIBLY ON THE STRONG TO BRIEFLY SEVERE SIDE IN WEST AND SOUTHWEST AREAS. TEMPERATURES WILL RISE QUICKLY THROUGH MORNING HOURS BUT BE TEMPERED BY SHOWER COVERAGE DURING THE AFTN. A SWIFT MOVING S/WV TROUGH ACROSS THE CENTRAL PLAINS IS SUSTAINING A MCS IN KS/OK/MO THIS MORNING AND IS ACTING TO FLATTEN THE ALREADY WEAK H7-H5 RIDGING OVER THE LOWER MS VALLEY. HI-RES GUIDANCE INDICATES THE MCS WILL SHIFT INTO OK/AR THROUGH THE DAWN HOURS AND SLOWLY WEAKEN AS IT GUSTS OUT. HOWEVER, HRRR/ARW SUGGEST A CONVERGENT BAND DEVELOPING FROM THIS OUTFLOW IN SOUTH AR AND NORTH LA BY LATE MORNING TO EARLY AFTN THAT COULD SERVE AS A FOCUS FOR MORE ORGANIZED ACTIVITY INTO WEST AND SOUTHWEST MS BY MID TO LATE AFTN. AHEAD OF THIS BOUNDARY, IT SHOULD ALSO BE NOTED THAT WITH SUCH A WARM START THIS MORNING, CONVECTIVE TEMPERATURES WILL BE REACHED 11AM-12PM AND ISO/SCT SHOWERS/TSTORMS WILL LIKELY DEVELOP ACROSS THE I-20 AND HWY 82 CORRIDORS. GREATER INSTABILITY WILL EXIST IN WEST IN CONJUNCTION WITH POSSIBLE CONVERGENCE BAND AND THIS MAY PROMOTE BETTER UPDRAFT STRENGTH AS SUPPORTED BY SPC SSEO OUTPUT. STORMS COULD BECOME STRONG TO BRIEFLY SEVERE WITH LOCALIZED WINDS IN THE 40-60 MPH RANGE AND FREQUENT LIGHTNING. WILL NOT FORMALLY INTRODUCE A LIMITED THREAT OF SEVERE JUST YET AS TO MONITOR HI-RES TRENDS AND ALLOW FOR MORNING SOUNDING ANALYSIS. SHOWERS/STORMS WILL DIMINISH THROUGH THE MID EVENING HOURS BUT SOME NEW ACTIVITY MAY DEVELOP IN NORTH MS ALONG AN ELEVATED BOUNDARY EARLY WEDNESDAY MORNING AND HAVE PLACED 20% POPS FOR FAR NORTH TIER COUNTIES. PWATS NEAR 2" WILL CONTINUE WEDNESDAY WITH ANOTHER ROUND OF SHOWERS/STORMS EXPECTED DURING THE AFTERNOON HOURS. THIS ACTIVITY ALSO SHOULD DECREASE THROUGH MID EVENING HOURS WITH QUIET CONDITIONS OVERNIGHT THURSDAY EXPECTED. /ALLEN/ THURSDAY THROUGH MONDAY... DEEP LAYERED RIDGE LOOKS TO REMAIN ANCHORED OVER THE LOWER CONUS THROUGH THE PERIOD. THIS SHOULD KEEP THE MOIST AND UNSTABLE AIRMASS LOCKED IN PLACE AND A CONTINUATION OF THE SENSIBLE WEATHER WE HAVE BEEN EXPERIENCING. WILL PRETTY MUCH HAVE TO CONTEND WITH AFTERNOON/EVENING AIRMASS CONVECTION EACH DAY THROUGH THE EXTENDED TIME FRAME. ALTHOUGH CONVECTIVE COVERAGE SHOULD REMAIN SCATTERED...STORMS MAY BE SOMEWHAT MORE NUMEROUS OVER THE SOUTH WHERE INTERACTIONS WITH THE SEA BREEZE MAY BE ENCOUNTERED. WENT CLOSE TO GFS MOS MAXIMUMS WITH HIGHS IN THE LOW TO MID 90S AS BELIEVE THIS LEVEL OF WARMING WILL STILL BE LIKELY GIVEN MID AFTERNOON CONVECTIVE INITIATION TIMES. MOVING INTO THE WEEKEND...SUBTLE MID LEVEL TROFFINESS OVER THE EASTERN PORTIONS OF THE COUNTRY WILL ALLOW A WEAK COLD FRONT TO EASE INTO THE REGION FROM THE NORTH SATURDAY NIGHT/SUNDAY. THE BOUNDARY LOOKS AS THOUGH IT WILL QUICKLY STALL OVER THE NORTH AND NOT OFFER ANYMORE THAN AN INCREASE IN CONVECTIVE COVERAGE FOR THE REMAINDER OF THE WEEKEND AND THE FIRST PART OF NEXT WEEK. WHILE THE COOL AIR BEHIND THE BOUNDARY SHOULD STAY TO THE NORTH OF THE AREA...INCREASED CONVECTION SUNDAY AND MONDAY SHOULD ONLY ALLOW MAXIMUMS TO REACH AROUND 90...BUT OVERNIGHT LOWS WILL REMAIN IN THE LOWER 70S./26/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 92 73 94 72 / 50 27 32 19 MERIDIAN 93 72 94 71 / 49 24 41 17 VICKSBURG 92 72 94 72 / 51 24 24 19 HATTIESBURG 94 75 95 73 / 52 30 50 21 NATCHEZ 90 74 92 72 / 54 30 40 23 GREENVILLE 93 73 94 73 / 50 20 19 14 GREENWOOD 92 73 94 72 / 46 20 27 14 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
718 AM EDT TUE SEP 2 2014 .SYNOPSIS... A WEAK COLD FRONT WILL MOVE ACROSS THE AREA TODAY EXTENDING FROM LOW PRESSURE TRACKING NORTHEAST ACROSS QUEBEC. HIGH PRESSURE WILL EXPAND OVER THE OHIO VALLEY TONIGHT...THEN TO THE EAST COAST ON WEDNESDAY. A WARM FRONT WILL LIFT NORTH ON THURSDAY AHEAD OF THE NEXT LOW PRESSURE SYSTEM THAT WILL PASS NORTH OF THE GREAT LAKES ON FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A SWATH OF RAIN CAN BE SEEN ON UPSTREAM RADARS SPREADING NORTHEAST ACROSS INDIANA EARLY THIS MORNING. THIS RAIN WILL CONTINUE TO BE PULLED NORTHEAST AHEAD OF THE SHORTWAVE ENERGY MOVING ACROSS THE PLAINS. THE 00Z SOUNDING OUT OF ILX SHOWED QUITE A BIT OF DRY AIR IN THE COLUMN AHEAD OF THIS DEEPER PUSH OF MOISTURE AND THIS NOW RESIDES OVER THE FORECAST AREA EARLY THIS MORNING. THE STRONGER MOISTURE ADVECTION IS FOCUSED NEAR 700MB AND THE DRIER LOW LEVEL AIR MAY CAUSE SOME EVAPORATION INITIALLY. THE BETTER INSTABILITY WILL BE LOCATED FARTHER SOUTH AND TRENDS HAVE BEEN FOR THE DEEP CONVECTION TO RESIDE ON THE SE FLANK OF THE PRECIPITATION SHIELD. WILL CARRY A HIGH POP FOR JUST ABOUT ALL AREAS THIS MORNING...ALTHOUGH WILL ONLY CARRY A CHANCE OF THUNDERSTORMS(BETTER CHANCES OF THUNDERSTORMS WILL BE LOCATED ALONG AND SOUTH OF INTERSTATE 70 IN CENTRAL OHIO). PRECIPITATION AMOUNTS WILL GENERALLY BE A HALF INCH OR LESS. LOW PRESSURE IS LOCATED JUST EAST OF JAMES BAY THIS MORNING WITH THE TRAILING COLD FRONT STILL LOCATED NORTH OF LAKE ERIE. THIS WEAK FRONT IS EXPECTED TO MOVE THROUGH TOLEDO AROUND NOON...CLEVELAND EARLY THIS AFTERNOON AND YOUNGSTOWN BY LATE AFTERNOON. ALTHOUGH THE INITIAL SURGE OF MOISTURE WILL EXIT TO THE EAST...THE FRONT WILL INTERACT WITH THE LINGERING MOISTURE WITH A CHANCE OF SHOWERS AND THUNDERSTORMS IN THE EASTERN AREAS THIS AFTERNOON. THE STORM PREDICTION CENTER HAS PLACED OUR SE TIER OF COUNTIES IN THE SLIGHT RISK FOR SEVERE THUNDERSTORMS TODAY. EXPECTING A CONSIDERABLE AMOUNT OF CLOUD COVER TO HAVE A LIMITING EFFECT ON HEATING/INSTABILITY ALONG AND AHEAD OF THE FRONT THIS AFTERNOON. BETTER CHANCES OF SEVERE WEATHER WILL BE LOCATED JUST SOUTH AND EAST OF THE AREA BUT CAN NOT ENTIRELY RULE OUT A SEVERE STORM IF HEATING IS STRONGER THAN EXPECTED. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... HIGH PRESSURE WILL EXPAND EASTWARD ACROSS THE OHIO VALLEY TONIGHT. IT LOOKS LIKE A WEAK THERMAL TROUGH WILL LINGER OVER LAKE ERIE ON THE NORTH SIDE OF THE HIGH THIS EVENING AND MAY PROVIDE ENOUGH CONVERGENCE FOR A FEW SHOWERS TO DEVELOP OVER THE LAKE. LEFT A LOW POP BOTH OVER THE LAKE AND ALONG THE EASTERN LAKESHORE FOR A PORTION OF THE NIGHT. INLAND AREAS...ESPECIALLY OUR SOUTHERN COUNTIES COULD SEE SOME FOG OR STRATUS GIVEN THE LINGERING BOUNDARY LAYER MOISTURE COUPLED WITH CLEARING SKIES AND LIGHT WINDS. TEMPERATURES WILL BOTTOM OUT IN THE UPPER 50S TO LOW 60S. THE AIRMASS DOES NOT COOL MUCH WITH THE FRONTAL PASSAGE AND TEMPERATURES ARE STILL EXPECTED TO BE A COUPLE DEGREES ABOVE NORMAL ON WEDNESDAY. THE MAIN DIFFERENCE WILL BE FELT IN THE HUMIDITY WHICH WILL BE LOWER AND MORE PLEASANT WITH DEWPOINTS NEAR 60 DEGREES. MAINLY JUST SCATTERED CU ON WEDNESDAY ONCE ANY MORNING CLOUDS BURN OFF. HEIGHTS WILL REBOUND OVER THE AREA ON THURSDAY AND A WARM FRONT WILL LIFT NORTH AHEAD OF THE NEXT LOW PRESSURE SYSTEM TRACKING OUT OF THE PLAINS. THIS SYSTEM IS FORECAST TO TRACK ACROSS LAKE SUPERIOR THEN CONTINUE NORTHEAST ACROSS ONTARIO AND QUEBEC. ENOUGH DRY AIR SHOULD STILL BE IN PLACE ON THURSDAY FOR THE FORECAST AREA TO STAY DRY. LEFT THE 20 POP IN THE FORECAST ON THURSDAY NIGHT AS MOISTURE DOES START TO INCREASE ALTHOUGH THE MORE FOCUSED MOISTURE ADVECTION WILL BE WELL TO THE NORTH. THE ASSOCIATED COLD FRONT WILL SINK SOUTH TOWARDS THE AREA ON FRIDAY. LOWERED POPS DURING THE MORNING HOURS AND ACROSS THE SOUTHERN COUNTIES THAT SHOULD STRUGGLE TO SEE ANY PRECIPITATION UNTIL FRIDAY NIGHT. TEMPERATURES ON THURSDAY AND FRIDAY WILL BE IN THE MID 80S...WITH A FEW SPOTS MAKING A RUN AT THE UPPER 80S. && .LONG TERM /SATURDAY THROUGH MONDAY/... NO BIG CHANGES TO THE MODELS FOR THE EXTENDED WITH GUIDANCE SHOWING A COLD FRONT TO OUR SOUTH SATURDAY MORNING WITH DRIER AIR AND HIGH MOVING IN FROM THE NORTH. DONT THINK THE DAY WILL BEGIN DRY HOWEVER AS THE ECMWF REMAINS SLOWER THAN THE GFS IN MOVING MOISTURE OUT OF THE AREA. WILL CONTINUE WITH CHANCE POPS THROUGH THE MORNING SATURDAY BEFORE DROPPING TO A SLIGHT CHANCE ACROSS THE NORTH. SATURDAY NIGHT THROUGH MONDAY LOOK DRY. TEMPS NEAR NORMAL AFTER AN ABOVE NORMAL END TO THE WEEK. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... WEAK COLD FRONT TO OUR NORTHWEST NR A KFNT-KSBN LINE. FROM WILL MOVE THROUGH THE AREA DURING THE DAY. CONVECTION FROM INDIANA TRACKING ENE ACROSS CENTRAL AND SRN OHIO. WILL LIKELY SEE THUNDER INTO NRN OHIO BUT KEPT MENTION OUT OF THE FAR NRN TAFS. HRRR MOVES THIS PRECIP THROUGH DURING THE MORNING AND EARLY AFTERNOON WITH POSSIBLY A FEW LINGERING SHOWERS FOR MID AFTERNOON. EXPECT MAINLY MVFR CONDITIONS WITH AND JUST BEHIND THE PRECIP...LIFTING TO VFR 2 TO 4 HOURS AFTER PRECIP ENDS. EXPECT THE EVENING WILL BEGIN VFR HOWEVER WITH LOW LEVEL MOISTURE IN PLACE...DRYING ALOFT AND HIGH PRESSURE OVER THE AREA EXPECT MVFR AND POSSIBLY IFR CIGS/FOG TO DEVELOP OVERNIGHT. OUTLOOK...NON VFR LIKELY IN SHOWERS AND THUNDERSTORMS BY FRIDAY EVENING INTO SATURDAY WITH THE NEXT COLD FRONT. && .MARINE... WILL BEGIN TODAY CLOSE TO SMALL CRAFT CRITERIA MAINLY EAST OF CONNEAUT BUT FOR NOW WILL CONTINUE WITH A FORECAST JUST BELOW. WINDS TODAY WILL BE FROM THE SOUTHWEST AHEAD OF A WEAK COLD FRONT DUE IN LATE MORNING/EARLY AFTERNOON. WINDS WILL TURN WEST TO BRIEFLY NORTHWEST BEHIND THE BOUNDARY. HIGH PRESSURE BUILDS IN TONIGHT AND WEDNESDAY. THURSDAY THE HIGH WILL DRIFT EAST AND A LOW WILL BE MOVING THROUGH THE NORTHERN PLAINS. THIS WILL AGAIN SETUP SOUTHWEST FLOW ON THE LAKE THURSDAY INCREASING TO 10 TO 20 KNOTS. THE LOW WILL MOVE THROUGH EASTERN CANADA FRIDAY DRAGGING A COLD FRONT ACROSS THE LAKE DURING THE AFTERNOON. WINDS WILL TURN NORTHWEST FRIDAY NIGHT AND SATURDAY BEHIND THE FRONT. ALTHOUGH CLOSE...NO NEAR TERM HEADLINES FOR NOW. FRIDAY INTO SATURDAY WE COULD REACH SMALL CRAFT CRITERIA AS WINDS TURN NORTHWEST. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KEC NEAR TERM...KEC SHORT TERM...KEC LONG TERM...TK AVIATION...TK MARINE...TK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
711 AM EDT TUE SEP 2 2014 .SYNOPSIS... A WEAK COLD FRONT WILL MOVE ACROSS THE AREA TODAY EXTENDING FROM LOW PRESSURE TRACKING NORTHEAST ACROSS QUEBEC. HIGH PRESSURE WILL EXPAND OVER THE OHIO VALLEY TONIGHT...THEN TO THE EAST COAST ON WEDNESDAY. A WARM FRONT WILL LIFT NORTH ON THURSDAY AHEAD OF THE NEXT LOW PRESSURE SYSTEM THAT WILL PASS NORTH OF THE GREAT LAKES ON FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LIGHT RAIN HAS SPREAD INTO THE TOLEDO AREA AND WILL CONTINUE TO PUSH EASTWARD. POPS REMAIN PRETTY HIGH WITH THE MORNING UPDATE ALTHOUGH SHOWERS WILL NOT LAST THAT LONG IN SOME AREAS. DRY AIR CAN ALREADY BE SEEN OVER NRN INDIANA AND THE COVERAGE AND INTENSITY OF SHOWERS HAS SHOWN A DECREASING TREND. STILL THINK MOST AREAS WILL SEE RAIN SO POPS REMAIN HIGH AND CAN BE LOWERED THROUGH THE DAY AS RAIN EXITS TO THE EAST. PREVIOUS DISCUSSION...A SWATH OF RAIN CAN BE SEEN ON UPSTREAM RADARS SPREADING NORTHEAST ACROSS INDIANA EARLY THIS MORNING. THIS RAIN WILL CONTINUE TO BE PULLED NORTHEAST AHEAD OF THE SHORTWAVE ENERGY MOVING ACROSS THE PLAINS. THE 00Z SOUNDING OUT OF ILX SHOWED QUITE A BIT OF DRY AIR IN THE COLUMN AHEAD OF THIS DEEPER PUSH OF MOISTURE AND THIS NOW RESIDES OVER THE FORECAST AREA EARLY THIS MORNING. THE STRONGER MOISTURE ADVECTION IS FOCUSED NEAR 700MB AND THE DRIER LOW LEVEL AIR MAY CAUSE SOME EVAPORATION INITIALLY. THE BETTER INSTABILITY WILL BE LOCATED FARTHER SOUTH AND TRENDS HAVE BEEN FOR THE DEEP CONVECTION TO RESIDE ON THE SE FLANK OF THE PRECIPITATION SHIELD. WILL CARRY A HIGH POP FOR JUST ABOUT ALL AREAS THIS MORNING...ALTHOUGH WILL ONLY CARRY A CHANCE OF THUNDERSTORMS(BETTER CHANCES OF THUNDERSTORMS WILL BE LOCATED ALONG AND SOUTH OF INTERSTATE 70 IN CENTRAL OHIO). PRECIPITATION AMOUNTS WILL GENERALLY BE A HALF INCH OR LESS. LOW PRESSURE IS LOCATED JUST EAST OF JAMES BAY THIS MORNING WITH THE TRAILING COLD FRONT STILL LOCATED NORTH OF LAKE ERIE. THIS WEAK FRONT IS EXPECTED TO MOVE THROUGH TOLEDO AROUND NOON...CLEVELAND EARLY THIS AFTERNOON AND YOUNGSTOWN BY LATE AFTERNOON. ALTHOUGH THE INITIAL SURGE OF MOISTURE WILL EXIT TO THE EAST...THE FRONT WILL INTERACT WITH THE LINGERING MOISTURE WITH A CHANCE OF SHOWERS AND THUNDERSTORMS IN THE EASTERN AREAS THIS AFTERNOON. THE STORM PREDICTION CENTER HAS PLACED OUR SE TIER OF COUNTIES IN THE SLIGHT RISK FOR SEVERE THUNDERSTORMS TODAY. EXPECTING A CONSIDERABLE AMOUNT OF CLOUD COVER TO HAVE A LIMITING EFFECT ON HEATING/INSTABILITY ALONG AND AHEAD OF THE FRONT THIS AFTERNOON. BETTER CHANCES OF SEVERE WEATHER WILL BE LOCATED JUST SOUTH AND EAST OF THE AREA BUT CAN NOT ENTIRELY RULE OUT A SEVERE STORM IF HEATING IS STRONGER THAN EXPECTED. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... HIGH PRESSURE WILL EXPAND EASTWARD ACROSS THE OHIO VALLEY TONIGHT. IT LOOKS LIKE A WEAK THERMAL TROUGH WILL LINGER OVER LAKE ERIE ON THE NORTH SIDE OF THE HIGH THIS EVENING AND MAY PROVIDE ENOUGH CONVERGENCE FOR A FEW SHOWERS TO DEVELOP OVER THE LAKE. LEFT A LOW POP BOTH OVER THE LAKE AND ALONG THE EASTERN LAKESHORE FOR A PORTION OF THE NIGHT. INLAND AREAS...ESPECIALLY OUR SOUTHERN COUNTIES COULD SEE SOME FOG OR STRATUS GIVEN THE LINGERING BOUNDARY LAYER MOISTURE COUPLED WITH CLEARING SKIES AND LIGHT WINDS. TEMPERATURES WILL BOTTOM OUT IN THE UPPER 50S TO LOW 60S. THE AIRMASS DOES NOT COOL MUCH WITH THE FRONTAL PASSAGE AND TEMPERATURES ARE STILL EXPECTED TO BE A COUPLE DEGREES ABOVE NORMAL ON WEDNESDAY. THE MAIN DIFFERENCE WILL BE FELT IN THE HUMIDITY WHICH WILL BE LOWER AND MORE PLEASANT WITH DEWPOINTS NEAR 60 DEGREES. MAINLY JUST SCATTERED CU ON WEDNESDAY ONCE ANY MORNING CLOUDS BURN OFF. HEIGHTS WILL REBOUND OVER THE AREA ON THURSDAY AND A WARM FRONT WILL LIFT NORTH AHEAD OF THE NEXT LOW PRESSURE SYSTEM TRACKING OUT OF THE PLAINS. THIS SYSTEM IS FORECAST TO TRACK ACROSS LAKE SUPERIOR THEN CONTINUE NORTHEAST ACROSS ONTARIO AND QUEBEC. ENOUGH DRY AIR SHOULD STILL BE IN PLACE ON THURSDAY FOR THE FORECAST AREA TO STAY DRY. LEFT THE 20 POP IN THE FORECAST ON THURSDAY NIGHT AS MOISTURE DOES START TO INCREASE ALTHOUGH THE MORE FOCUSED MOISTURE ADVECTION WILL BE WELL TO THE NORTH. THE ASSOCIATED COLD FRONT WILL SINK SOUTH TOWARDS THE AREA ON FRIDAY. LOWERED POPS DURING THE MORNING HOURS AND ACROSS THE SOUTHERN COUNTIES THAT SHOULD STRUGGLE TO SEE ANY PRECIPITATION UNTIL FRIDAY NIGHT. TEMPERATURES ON THURSDAY AND FRIDAY WILL BE IN THE MID 80S...WITH A FEW SPOTS MAKING A RUN AT THE UPPER 80S. && .LONG TERM /SATURDAY THROUGH MONDAY/... NO BIG CHANGES TO THE MODELS FOR THE EXTENDED WITH GUIDANCE SHOWING A COLD FRONT TO OUR SOUTH SATURDAY MORNING WITH DRIER AIR AND HIGH MOVING IN FROM THE NORTH. DONT THINK THE DAY WILL BEGIN DRY HOWEVER AS THE ECMWF REMAINS SLOWER THAN THE GFS IN MOVING MOISTURE OUT OF THE AREA. WILL CONTINUE WITH CHANCE POPS THROUGH THE MORNING SATURDAY BEFORE DROPPING TO A SLIGHT CHANCE ACROSS THE NORTH. SATURDAY NIGHT THROUGH MONDAY LOOK DRY. TEMPS NEAR NORMAL AFTER AN ABOVE NORMAL END TO THE WEEK. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... WEAK COLD FRONT TO OUR NORTHWEST WITH BEST GUESS POSITION FROM CENTRAL LWR MI SW INTO MO. MCS ACROSS MO AND SRN IL WHILE A FEW LINGERING SHOWERS ALONG WITH A LITTLE THUNDER ACROSS FAR EASTERN ERIE COUNTY PA AND EAST INTO WRN NY. THAT ACTIVITY WILL CONTINUE EAST OUT OF THE AREA OVER THE NEXT HOUR OR TWO. HRRR DOES SHOW SOME REDEVELOPMENT OVER ERIE COUNTY AND WILL ACCOUNT FOR THAT IN THE TAF. OTHERWISE MAINLY VFR ACROSS THE AREA THIS HOURS ALTHOUGH THE HRRR DOES SHOW ACTIVITY TO OUR WEST MOVING INTO THE AREA TOWARDS MORNING. EXPECT THE BULK OF THE CONVECTION TO REMAIN SOUTH OF OUR AREA...TRACKING ACROSS CENTRAL AND SRN OHIO...HOWEVER SO EXPECT SOME PRECIP TO EXTEND NORTH AND AFFECT THE AREA. BROUGHT SHOWERS INTO KTOL/KFDY AROUND 10Z AND KCLE/KMFD 11-12Z AND KERI- KYNG 14-15Z. ALSO INCLUDED VCTS BUT FOR NOW DID NOT INCLUDE THUNDER IN TEMPO GROUPS. HELD ONTO MVFR CIGS THROUGH THE BALANCE OF THE MORNING GIVEN DEEP HIGH RH ACROSS THE AREA. DRIER AIR SHOULD BEGIN MOVING IN THROUGH THE AFTERNOON. OUTLOOK...NON VFR LIKELY IN SHOWERS AND THUNDERSTORMS BY FRIDAY EVENING INTO SATURDAY WITH THE NEXT COLD FRONT. && .MARINE... WILL BEGIN TODAY CLOSE TO SMALL CRAFT CRITERIA MAINLY EAST OF CONNEAUT BUT FOR NOW WILL CONTINUE WITH A FORECAST JUST BELOW. WINDS TODAY WILL BE FROM THE SOUTHWEST AHEAD OF A WEAK COLD FRONT DUE IN LATE MORNING/EARLY AFTERNOON. WINDS WILL TURN WEST TO BRIEFLY NORTHWEST BEHIND THE BOUNDARY. HIGH PRESSURE BUILDS IN TONIGHT AND WEDNESDAY. THURSDAY THE HIGH WILL DRIFT EAST AND A LOW WILL BE MOVING THROUGH THE NORTHERN PLAINS. THIS WILL AGAIN SETUP SOUTHWEST FLOW ON THE LAKE THURSDAY INCREASING TO 10 TO 20 KNOTS. THE LOW WILL MOVE THROUGH EASTERN CANADA FRIDAY DRAGGING A COLD FRONT ACROSS THE LAKE DURING THE AFTERNOON. WINDS WILL TURN NORTHWEST FRIDAY NIGHT AND SATURDAY BEHIND THE FRONT. ALTHOUGH CLOSE...NO NEAR TERM HEADLINES FOR NOW. FRIDAY INTO SATURDAY WE COULD REACH SMALL CRAFT CRITERIA AS WINDS TURN NORTHWEST. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KEC NEAR TERM...KEC SHORT TERM...KEC LONG TERM...TK AVIATION...TK MARINE...TK
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1026 AM CDT TUE SEP 2 2014 .UPDATE... SEE MORNING UPDATE. && .DISCUSSION... 12Z SOUNDINGS SHOW PW VALUES BETWEEN 2.1 AND 2.2 INCHES AND THIS IS SUPPORTED BY GPS MET DATA, CONVECTIVE TEMPS ARE BETWEEN 86 AND 88 DEGREES TODAY AND THIS THRESHOLD WILL BE MET EASILY. A WELL DEVELOPED S/WV EXTENDS FROM CENTRAL ARKANSAS INTO CENTRAL TEXAS WHICH SERVE AS ANOTHER FOCUS FOR SHRA/TSRA. UPPER LEVEL RIDING HAS INCHED CLOSER TO SE TX WHICH WILL IMPART A BIT OF SUBSIDENCE. THE RAP IS VERY AGGRESSIVE WITH RAINFALL THIS AFTN WHILE THE HRRR/ARW-EAST REMAIN MORE BENIGN. THE RAP WAS OVERDONE YESTERDAY AND DID NOT INITIALIZE ALL THAT WELL SO HAVE LEANED TOWARD A HRRR/WRF BLEND. CHANCE POPS LOOK APPROPRIATE SO NO CHANGES TO THE POP/WX GRIDS. DID BUMP MAX T GRIDS UP A FEW DEGREES TO MATCH TRENDS/OBS. AS FOR TS DOLLY...THE STORM WILL PROBABLY MAKE LANDFALL A BIT EARLIER...SOMETIME THIS EVENING. THE MAIN EFFECT FOR SE TX WILL BE INCREASING SWELLS OVER THE OFFSHORE MARINE ZONES AND A 1.0-1.5 FOOT BUMP UP IN TIDE LEVELS. NEW ZONES OUT BY 1030 AM. 43 && .PREV DISCUSSION... /ISSUED 629 AM CDT TUE SEP 2 2014/ AVIATION... MOSTLY SCT CLOUDS ACROSS THE AREA THIS MORNING. SHRA/TSRA MOVING TO THE NNW OUT OF THE GULF ARE SO FAR HAVING TROUBLE MAKING IT PAST THE COASTAL COUNTIES. ACTIVITY SHOULD SPREAD/DEVELOP FURTHER INLAND LATER THIS MORNING AND THIS AFTERNOON DUE TO DAYTIME HEATING AND INCREASING INSTABILITY. GOING WITH VCTS/TSRA FOR THIS MORNING NEAR THE COAST AND INLAND THIS AFTERNOON. THINGS SHOULD QUIET DOWN THIS EVENING WITH THE LOSS OF HEATING. MVFR CEILING DEVELOPMENT POSSIBLE LATE TONIGHT THROUGH EARLY WEDNESDAY MORNING. 42 PREV DISCUSSION... /ISSUED 405 AM CDT TUE SEP 2 2014/ DISCUSSION... A FEW SHOWERS ARE MOVING NORTHWARD ACROSS THE COASTAL WATERS THIS MORNING IN ASSOCIATION WITH AN AREA OF DEEPER MOISTURE WHICH IS APPROACHING THE UPPER TEXAS COAST. FURTHER TO THE SOUTH...TD 5 HAS STRENGTHENED INTO TROPICAL STORM DOLLY THIS MORNING. THE CENTER OF THE SYSTEM HAS FORMED A BIT FURTHER NORTH THAT PREVIOUSLY EXPECTED WHICH HAS CAUSED A CORRESPONDING SHIFT IN THE FORECAST TRACK. THE ONLY ADDITIONAL IMPACTS TO SOUTHEAST TEXAS WILL BE SOME SLIGHTLY HIGHER SEAS OFFSHORE AS THE NEW TRACK STILL TAKES THE SYSTEM INTO MEXICO WELL SOUTH OF THE BORDER. EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP INLAND LATER THIS MORNING AS MOISTURE STREAMS BACK INTO THE REGION. COVERAGE SHOULD INCREASE ACROSS OUR NORTHERN COUNTIES LATE THIS AFTERNOON AS A PASSING SHORTWAVE BRINGS ADDITIONAL LIFT TO THE REGION. GIVEN THE RICH MOISTURE A FEW BRIEF HEAVY DOWNPOURS WILL BE POSSIBLE WITH THE ACTIVITY TODAY. HIGH TEMPERATURES SHOULD REMAIN IN THE LOW TO MID 90S AREAWIDE WITH THE PRECIPITATION AND GREATER CLOUD COVER. ONLY SLIGHT CHANGES FOR THE MID TO EXTENDED RANGE FORECAST THIS MORNING. THE UPPER LEVEL PATTERN OVERHEAD REMAINS RELATIVELY UNCHANGED THROUGH THE WEEK WITH A BROAD FLAT RIDGE ACROSS THE SOUTHERN UNITED STATES. THIS WILL ALLOW FOR CONTINUED DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS WITH HIGH TEMPERATURES IN THE LOW TO MID 90S...NEAR THE NORMALS FOR THE FIRST WEEK OF SEPTEMBER. 38 MARINE... TROPICAL STORM DOLLY IS LOCATED IN THE BAY OF CAMPECHE EARLY THIS MORNING. BASED ON THE CURRENT FORECAST...DOLLY IS EXPECTED TO APPROACH THE COAST OF MEXICO BY TONIGHT AND MOVE INLAND BY WEDNESDAY MORNING. BUILDING SEAS CAN BE EXPECTED ALONG THE UPPER TEXAS COAST. CAUTION FLAGS ARE CURRENTLY IN EFFECT...AND ADVISORIES MIGHT BE NEEDED IF SEAS BUILD HIGHER THAN ANTICIPATED. PERIODS OF SHOWERS AND THUNDERSTORMS CAN BE EXPECTED ACROSS OUR AREA OVER THE NEXT COUPLE OF DAYS. TOWARD THE END OF THE WEEK...EXPECT WEAKENING ONSHORE WINDS AND LOWERING SEAS. 42 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 94 75 95 75 94 / 30 20 20 10 20 HOUSTON (IAH) 93 77 93 76 92 / 40 20 30 10 20 GALVESTON (GLS) 89 81 91 81 90 / 30 20 30 20 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 8 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
627 AM CDT TUE SEP 2 2014 .AVIATION... /12Z TAFS/ VFR conditions should prevail across most West Central Texas terminals through the period. However, we are seeing the expected MVFR stratus developing on low cloud imagery, although remaining pretty patchy at this point. Suspect that it will expand a little more through sunrise, and then quickly dissipate. Even at those locations it does effect, it will be a move in and out quickly type of feature. Otherwise, gusty south winds through daylight hours with just a scattered afternoon cu field developing. && .PREV DISCUSSION... /ISSUED 354 AM CDT TUE SEP 2 2014/ SHORT TERM... (Today and Tonight) Another mild night ongoing across West Central Texas, with south winds remaining strong enough to keep temperatures from dropping very much. Readings still right around 80 degrees at 3 AM (08Z). Models do indicate that some patchy low cloudiness will develop by sunrise and spread northward into the area, with low cloud satellite imagery showing some of this starting to develop across portions of Central Texas. Another hot day in store for the area, with the upper level ridge of high pressure in control. The 00Z NAM showed some convection across West Central Texas this afternoon, but the GFS is dry. Both the TTU WRF and the HRRR both show a similar pattern, scattered sea breeze activity pushing well inland today, but dissipating at sunset across Central Texas. Thus, will not insert PoPs into the forecast. After readings above the 100 degree mark at San Angelo and Abilene, models indicate a slight cooling at 850MB today as a little cooler and more moist air mass from the Gulf of Mexico slides into the area. Will keep afternoon highs below the 100 degree mark, but still a degree or two above guidance. Mild again tonight as south winds keep temperatures from dropping very quickly. Again, stayed just a little above guidance, as it has been too cool for the last several days. LONG TERM... Surface temperatures fall 2 to 3 degrees F Wednesday as 850 MB temperatures fall another 1 to 2 degrees Celsius. Tropical Storm Dolly in the Bay of Campeche is expected to move into Mexico early Wednesday, and may send weak disturbances/moisture northward to affect the I-10 corridor Thursday and Friday. This is indicated mainly by the EC model, as the GFS model is dry and the NAM model nearly so. Will keep rain chances out of forecast for this time period, given the uncertainty and limited agreement in the models. For Saturday night into Sunday, however, both the GFS and EC modes are still indicating a weak cold front to bring a slight chance of showers and thunderstorms. Forecast already has rain chances in for this time period, and will maintain them. && .PRELIMINARY POINT TEMPS/POPS... Abilene 100 76 96 74 95 / 5 5 5 5 5 San Angelo 98 75 95 74 94 / 5 5 10 10 10 Junction 95 77 93 74 93 / 10 10 10 10 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07
CONTINUE ON WITH THE FORECAST DISCUSSION...

IN A BASIC SENSE...THE MOVEMENT OF THUNDERSTORM SYSTEMS IS CONTROLLED BY THE AVERAGE OF THE WINDS ALOFT...OFTEN REFERRED TO AS THE STEERING WINDS. IN MOST CASES...THUNDERSTORMS WILL SIMPLY MOVE IN THE DIRECTION IN WHICH THE WINDS ALOFT ARE BLOWING. HOWEVER THE SECOND COMPONENT TO CONSIDER IS OFTEN REFERRED TO AS THE PROPAGATION COMPONENT OF STORM MOTION. PROPAGATION INFLUENCES STORM MOTION BY CHANGING THE DIRECTION OF MOTION OF A THUNDERSTORM SYSTEM IN THE DIRECTION THAT NEW THUNDERSTORMS DEVELOP. THIS IS THE MORE COMPLICATED FACTOR TO UNDERSTAND...BUT IN GENERAL...NEW THUNDERSTORMS TEND TO DEVELOP IN THE OPPOSITE DIRECTION OF THE LOW LEVEL JET. ON A DAY LIKE TODAY...WHERE THE STEERING WINDS ARE SOMEWHAT LIGHT DUE TO UPPER LEVEL RIDGING OVER TEXAS...BUT THE LOW-LEVEL JET IS RELATIVELY STRONG...THE PROPAGATION COMPONENT CAN DOMINATE THE DIRECTION IN WHICH THE THUNDERSTORM SYSTEM MOVES. FOR TODAY...THE STEERING WINDS ARE SOMEWHAT LIGHT AND WOULD INDICATE AN EASTERLY STORM MOTION. THIS IS WHY THE STORMS ARE JUST SORT OF SITTING THERE ALONG THE FRONT AS OF 3 AM. HOWEVER IF THIS RESULTS IN A STRONG ENOUGH COLD POOL (A COLLECTION OF RAIN COOLED AIR) THIS COLD POOL COULD START TO SURGE SOUTH...CAUSING NEW STORMS TO DEVELOP IN THE OPPOSITE DIRECTION OF THE LOW-LEVEL JET. SINCE THE LOW-LEVEL JET EXTENDS FROM OUR CWA TO THE FRONT...THE WHOLE COMPLEX OF STORMS COULD START TO MOVE SOUTH DIRECTLY TOWARDS THE RED RIVER...BUT WILL STILL MOVE AT LEAST SLIGHTLY TO THE EAST DUE TO THE STEERING WINDS ALOFT. THIS IS A DRAMATIC SHIFT IN DIRECTION FROM WHAT STORMS HAVE BEEN DOING OVERNIGHT...BUT IT MAKES SENSE IN THE CONTEXT OF WHAT WAS DESCRIBED ABOVE. THE MAIN POINT OF UNCERTAINTY THIS MORNING IS: WILL THUNDERSTORMS BECOME ORGANIZED ENOUGH TO MOVE AS A SYSTEM? THAT IS LARGELY UNKNOWN BECAUSE JUST LOOKING AT THE STORMS ON RADAR IS NOT ENOUGH TO DETERMINE HOW STRONG THE COLD POOL WILL GET...BUT THE FACT THAT THE HRRR AND THE TEXAS TECH WRF BOTH ADVERTISE A DRAMATIC SHIFT TO THE SOUTH OF THUNDERSTORMS TOWARDS THE RED RIVER AROUND SUNRISE GIVES CONFIDENCE IN THIS SOLUTION. WENT AHEAD AND PLACED A VERY SMALL AREA OF 20 POPS IN THE FORECAST FROM JUST NORTH OF SHERMAN EXTENDING TO THE SOUTHEAST INCLUDING MUCH OF LAMAR COUNTY. IF THE STORMS DO MOVE TO THE SOUTH AS THESE HIGH RESOLUTION MODELS INDICATE...THEY WILL BE IN THEIR DISSIPATING STAGES BY THE TIME THEY CROSS THE RED RIVER WELL AFTER SUNRISE THIS MORNING...SO NO STRONG OR SEVERE WEATHER IS EXPECTED AT THIS TIME. THIS AFTERNOON...MODELS CONTINUE TO CONSISTENTLY SHOW A SURGE OF TROPICAL MOISTURE TO THE NORTHWEST FROM THE TX GULF COAST THIS AFTERNOON. THIS SURGE OF MOISTURE APPEARS TO BE ASSOCIATED WITH A SUBTLE BUT IMPORTANT MID-LEVEL WIND SHIFT ASSOCIATED WITH DOLLY MOVING NORTHWEST TOWARDS THE NORTHERN MEXICO GULF COAST. THIS DEEPER TROPICAL MOISTURE IS EXPECTED TO REMAIN SOUTH OF THE INTERSTATE 20 CORRIDOR THIS AFTERNOON...SO REORIENTED POPS A BIT TO HIGHLIGHT THE SOUTHERN HALF OF THE CWA. IN GENERAL...THERE IS STILL NO OBVIOUS LIFT...SO THE COVERAGE OF STORMS WILL PROBABLY BE ISOLATED IN NATURE...AND LEFT POPS AT THE 20 PERCENT LEVEL FOR NOW. WEDNESDAY THROUGH FRIDAY...DOLLY IS EXPECTED TO MAKE LANDFALL OVER NORTHERN MEXICO LATE THIS EVENING...AND THEN CONTINUE OFF TO THE WEST-NORTHWEST THROUGH THE END OF THE WEEK. MODELS SEEM TO SEND THE DEEPER MID-LEVEL TROPICAL MOISTURE PLUME TO THE WEST WITH DOLLY...SO WENT AHEAD AND REMOVED POPS FROM THE FORECAST ON WEDNESDAY AFTERNOON ACROSS THE SOUTHERN CWA AND LEFT THE REMAINDER OF THE FORECAST DRY. WEAK UPPER LEVEL RIDGING IS THE DOMINANT FEATURE DURING THIS TIME FRAME...SO EXPECT SUBSIDENCE TO WIN OUT IN KEEPING THINGS DRY ACROSS NORTH AND CENTRAL TEXAS. THIS WEEKEND...MODELS CONTINUE TO HINT AT A COLD FRONT MOVING SOUTH OF THE RED RIVER SOMETIME SATURDAY AFTERNOON THROUGH SUNDAY MORNING. MODELS STILL SEEM TO INDICATE THAT THE PRIMARY REASON THAT THE FRONT MAKES IT SOUTH OF THE RED RIVER IS DUE TO PERSISTENT THUNDERSTORM ACTIVITY ALONG THE FRONT LATE THIS WEEK. IF THE FRONTAL MOTION IS REALLY DEPENDENT UPON PERSISTENT THUNDERSTORM ACTIVITY...CONFIDENCE IN THE TIMING AND PLACEMENT OF THE FRONT IS GOING TO REMAIN LOW UNTIL LATE THIS WEEK. THE BIGGEST REASON FOR OPTIMISM IN THE FRONT MAKING IT THIS FAR SOUTH IS OBSERVING WHAT HAPPENS TODAY. IF MCS ACTIVITY FROM THE OK/KS BORDER ACTUALLY SURGES SOUTH THIS MORNING...IT BECOMES EASY TO SEE HOW PERSISTENT STORMS TO OUR NORTH CAN SEND A STRONG OUTFLOW BOUNDARY/FRONT ACROSS NORTH TEXAS UNDER WEAK RIDGING ALOFT. THE FRONT IS MOST LIKELY TO BE IN PLACE OVER THE CWA ON SUNDAY...SO LEFT POPS MAINLY ALONG AND NORTH OF INTERSTATE 20 ON SATURDAY...AND KEPT THEM BROAD BRUSHED OVER THE ENTIRE CWA ON SUNDAY. EARLY NEXT WEEK...THE FRONT...ASSUMING IT MAKES IT HERE THIS WEEKEND...WILL PROBABLY DISSIPATE BY MONDAY. BECAUSE THE FRONT DOES NOT REPRESENT A TRUE AIRMASS REPLACEMENT...THAT IS...THERE IS NO CANADIAN/OR SIGNIFICANTLY COOL AIR TO THE NORTH OF THIS FRONT...IT WILL UNDERGO FRONTOLYSIS AND LOSE DEFINITION QUICKLY UNDER RIDGING ALOFT. LEFT THE FORECAST FOR EARLY NEXT WEEK DRY AS A RESULT. CAVANAUGH && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 97 77 96 77 96 / 5 5 5 5 0 WACO, TX 98 75 97 74 97 / 20 20 10 5 5 PARIS, TX 92 72 91 72 92 / 20 10 5 5 0 DENTON, TX 96 75 95 74 95 / 10 5 5 0 0 MCKINNEY, TX 95 74 94 74 94 / 10 5 5 5 0 DALLAS, TX 97 78 96 78 96 / 5 5 5 5 0 TERRELL, TX 96 76 96 75 96 / 10 10 5 5 0 CORSICANA, TX 97 76 96 75 96 / 20 20 10 5 5 TEMPLE, TX 98 72 97 73 97 / 20 20 10 5 5 MINERAL WELLS, TX 97 73 96 72 96 / 5 5 5 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 82/69
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
309 PM MDT TUE SEP 2 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 308 PM MDT TUE SEP 2 2014 ALL IS QUIET ON THE WESTERN FRONT THIS AFTERNOON. A BIT OF CUMULUS HAS DEVELOPED OVER THE HIGH COUNTRY ABOUT AS EXPECTED WHICH SHOULD DISSIPATE WITH THE SETTING SUN. LITTLE IN THE WAY OF QUASI- GEOSTROPHIC DYNAMICS EXPECTED THROUGH THE PERIOD. PRECIPITABLE WATER VALUES ARE FORECAST TO BE A BIT HIGHER TOMORROW THAN IS THE CASE TODAY BUT STILL NOTHING TO GET EXCITED ABOUT...MAYBE SOME MORE CUMULUS THAN TODAY. THE CIRA WRF SIMULATED SATELLITE IMAGERY DEPICTS SOME STRATUS OVER LINCOLN COUNTY AND ITS ENVIRONS AROUND SUNRISE WEDNESDAY...SIMILAR TO TODAY...AND HAVE INCLUDED THIS IN THE GRIDS. THE MAIN ISSUE FOR TOMORROW IS AN INCREASE IN THE WINDS AND THE ABOVE NORMAL HIGH TEMPERATURES DUE TO INCREASING PRESSURE GRADIENTS AND DOWNSLOPE COMPONENT. BEASTLY 90+ READINGS ARE EXPECTED AT LOWER ELEVATIONS WITH ABOVE NORMAL MAXIMA IN THE HIGH COUNTRY AS WELL. OFFICIAL RECORD HIGH OF 95 AT DIA SET IN 1995 COULD BE THREATENED. LOW HUMIDITIES IN AND CLOSE TO THE MOUNTAINS WILL COMBINE WITH THE WINDS TO ELEVATE THE FIRE DANGER ESPECIALLY IN SOUTH PARK. NO PLANS FOR FIRE WEATHER HIGHLIGHTS AT THIS TIME. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 308 PM MDT TUE SEP 2 2014 DRY WEATHER WILL REMAIN IN PLACE THROUGH WEDNESDAY NIGHT AND MOST OF THURSDAY. BY LATE THURSDAY...MID/UPPER LEVEL MOISTURE BEGINS TO INCREASE IN/NEAR THE MOUNTAINS BY LATE IN THE DAY. THE LOW LEVELS ARE QUITE STABLE SO ANY CONVECTIVE SHOWERS/STORMS THAT DEVELOP IN THE HIGH COUNTRY WILL LIKELY DISSIPATE AS THEY ATTEMPT TO MOVE INTO THE LOWER ELEVATIONS OF THE PLAINS. HAVE TRIMMED BACK THE EASTERN EXTENT OF THE ALREADY LOW POPS...BUT SOME FURTHER REFINEMENT COULD BE NECESSARY TO REMOVE THEM FROM THE I-25 CORRIDOR AS WELL. FOR NOW...HAVE KEPT LOW POPS IN CONSIDERING OUR PROXIMITY TO THE RIGHT REAR ENTRANCE REGION OF DEPARTING UPPER LEVEL SPEED MAX. ON FRIDAY AND SATURDAY...SURFACE HIGH PRESSURE BUILDS OVER THE CENTRAL PLAINS. THIS WILL KEEP A RELATIVELY COOL AND SLIGHTLY STABLE AIRMASS ACROSS MOST OF THE COLORADO PLAINS. AT THE SAME TIME...THERE IS A MODEST THETA-E RIDGE BUILDING ALONG THE FRONT RANGE AND OVER THE MOUNTAINS...WHICH SHOULD BRING SCATTERED SHOWER/STORM DEVELOPMENT EACH AFTERNOON AND EVENING. WOULD EXPECT A FEW OF THESE TO DRIFT ONTO THE PLAINS EACH LATE AFTERNOON/EVENING AS WELL...WITH A WEAKER CAP AND AGAIN THE CLOSE PROXIMITY OF THE UPPER LEVEL SPEED MAX. TEMPERATURES SHOULD REMAIN A FEW DEGREES BELOW NORMAL ON THE PLAINS WITH THE COOLER HIGH PRESSURE AND LIGHT EASTERLY UPSLOPE FLOW ACROSS THE HIGH PLAINS. ON SUNDAY...WEAK LEE TROUGHING WILL LIKELY DEVELOP AS CENTRAL PLAINS HIGH PRESSURE RETREATS TO THE EAST. THIS SHOULD ALLOW TEMPERATURES TO REBOUND TO NEAR NORMAL TEMPERATURES. CAPES MAY ALSO INCREASE WITH SOUTHERLY LOW LEVEL FLOW AND INCREASED LOW LEVEL MOISTURE...RESULTING IN A FEW STRONGER STORMS. OVERALL... THE FORECAST AREA REMAINS ON THE NORTHERN EDGE OF ANY DEEPER MONSOONAL MOISTURE SO THE THREAT OF ANY HEAVY RAINFALL IS LOW DUE TO EXPECTED FASTER STORM MOTIONS AND LIMITED PRECIPITABLE WATER. BY LATE MONDAY OR TUESDAY...WE SEE SOME POTENTIAL FOR DRYING WITH A LARGER TROUGH MOVING IN FROM THE PACIFIC NORTHWEST. THIS WOULD SWEEP ANY DEEPER MOISTURE TO THE EAST AND LOWER THE CHANCE OF ANY SHOWERS/STORMS. TIMING IS SOMEWHAT UNCERTAIN HERE WITH THE LATEST 12Z ECMWF SHOWING A SLOWER EASTWARD ADVANCEMENT OF THIS TROUGH. && .AVIATION...(FOR THE TAFS THROUGH 00Z WEDNESDAY LATE AFTERNOON) ISSUED AT 308 PM MDT TUE SEP 2 2014 CAVOK THROUGH WEDNESDAY. A WEAK WESTERLY PUSH SWUNG THE WINDS AROUND TO WESTERLY AT KDEN. THE FEATURE SHOWS UP ON THE DOPPLER VELOCITY BUT IT IS NOT CLEAR WHAT IT IS. THE HRRR HAS A HINT OF IT BUT IT WASHES OUT LATER THIS AFTERNOON WITH EAST SOUTHEASTERLIES REFORMING. THE OTHER TWO TERMINALS WERE LESS IMPACTED BY THIS. DRAINAGE FLOW EXPECTED TO FORM OVERNIGHT WHICH MAY BE A ENHANCED JUST A BIT LATE TONIGHT AS LOW PRESSURE DEVELOPS TO OUR NORTHEAST. EXPECTING GENERALLY LIGHT FLOW TOMORROW WHICH SHOULD FAVOR A SOUTHWESTERLY DIRECTION. && .BOU WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...ET LONG TERM...BARJENBRUCH AVIATION...ET
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
332 PM EDT TUE SEP 2 2014 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION TONIGHT. HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE WEST AND PERSIST THROUGH FRIDAY. ANOTHER COLD FRONT WILL CROSS THE REGION ON SATURDAY AND THEN STALL TO THE SOUTH OF OUR AREA. HIGH PRESSURE WILL BUILD ACROSS THE GREAT LAKES REGION AND THEN SLIDE ACROSS TO THE NORTH OF THE REGION EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... FRONT IS JUST NOW MOVING OFF THE GREAT LAKES INTO FAR WESTERN PA. DO NOT EXPECT IT TO MAKE ITS ARRIVAL MUCH BEFORE 06Z. HIGH RES MODELS LIKE THE HRRR HAVE BEEN CONSISTENT IN SHOWING A LINE OF CONVECTION MOVING IN AHEAD OF THE FRONT LATE THIS EVENING. HOWEVER, BY THAT TIME, INSTABILITY SHOULD BE WANING AND THERE COULD BE A SMALL BOUNDARY LAYER INVERSION. THUS, THE LINE SHOULD BE DISSIPATING AS IT MOVES THROUGH THE REGION. PWATS ARE STILL WELL ABOVE NORMAL, SO LOCALIZED HEAVY RAIN WILL BE POSSIBLE. WHILE THE HIGHEST SHEAR VALUES SHOULD REMAIN NW OF OUR REGION, COULD SEE A FEW STRONG WINDS GUSTS WHEN THE FRONT INITIALLY ARRIVES IN SOUTHEAST PA BUT THAT THREAT SHOULD BE SHORT LIVED AS WE TRANSITION FROM SURFACE BASED TO ELEVATED INSTABILITY. GIVEN THE VERY LATE ARRIVAL OF THE COLD FRONT, AND THE FACT THAT THE TEMPERATURE GRADIENT ACROSS THE FRONT IS RATHER SMALL, MINS TONIGHT SHOULD NOT BE TOO MUCH LOWER THAN THEY WERE THIS MORNING. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... AS MENTIONED PREVIOUSLY, THERE WON`T BE A LARGE DIFFERENCE IN THE TEMPERATURES POST FRONTAL (HIGHS WILL GENERALLY BE IN THE 80S ACROSS THE REGION). HOWEVER, WHAT THE FRONT WILL BE BRINGING IS CONSIDERABLE DRY AIR ADVECTION. DEW POINTS INTO THE UPPER 50S AND LOWER 60S ACROSS THE REGION BY TOMORROW AFTERNOON. THUS, WHILE HEAT INDEX VALUES HAVE BEEN ABOUT 5 DEGREES ABOVE AIR TEMPERATURE TODAY, BY TOMORROW, HEAT INDEX VALUES WILL BE RIGHT AT THE AIR TEMPERATURES. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... WEDNESDAY NIGHT THROUGH FRIDAY...HIGH PRESSURE DOMINATES OUR WEATHER THROUGH THE END OF THE WEEK AS IT SHIFTS JUST TO TOUR SOUTH AND EAST LATE WEDNESDAY THROUGH FRIDAY. THIS WILL KEEP US IN A MORE SOUTH TO SOUTHWESTERLY FLOW AND IN RETURN WE WILL CONTINUE TO SEE AN INCREASE IN MOISTURE ACROSS THE REGION. TEMPERATURES WILL CONTINUE TO MIMIC MORE OF MID SUMMER AS OPPOSED TO LATE SUMMER AND WE WILL SEE MAX TEMPS REACH INTO THE UPPER 80S TO AROUND 90 ON BOTH THURSDAY AND FRIDAY. SATURDAY...THE HIGH SHIFTS FURTHER OFFSHORE AND WE WILL BE AWAITING THE PASSAGE OF A COLD FRONT THROUGH THE DAY. THE FRONT APPEARS TO BE SLOW MOVING AND MAY TAKE ALL DAY TO CROSS FROM THE NORTHWESTERN PORTIONS OF THE AREA AND THEN THROUGH THE SOUTHERN MOST POINTS. WE WILL LIKELY SEE A PRE-FRONTAL TROUGH DEVELOP ACROSS THE AREA AND THIS WILL LIKELY HELP SERVE AS A FOCUS FOR ANY PRE-FRONTAL CONVECTION AND SHOWERS. SATURDAY WILL BE THE LAST DAY OF THIS HEAT WAVE AS COOLER AIR BEHIND THE FRONT WILL DROP TEMPS QUITE A BIT. SUNDAY...THE FRONT IS SLOW ENOUGH THAT WE MAY NOT SEE IT CLEAR THE DELMARVA AREA UNTIL SUNDAY MORNING. AS THE FRONT PUSHES SOUTH, THE QUESTION WILL BE, WHERE WILL THE FRONT STALL? CURRENT MODEL GUIDANCE INDICATES THAT THE FRONT WILL HAVE ENOUGH OF A PUSH TO GET SOUTH OF OUR AREA, WHICH SHOULD ALLOW FOR SOME COOLER AND DRIER AIR TO INFILTRATE OUR REGION. THE SLOW NATURE OF THE FRONT WILL ALLOW FOR SHOWERS TO CONTINUE, ESPECIALLY FURTHER SOUTH, INTO SUNDAY. AS THE FRONT PUSHES FURTHER SOUTH, ANY LINGERING SHOWERS SHOULD END FROM NORTH TO SOUTH. WITH HIGH PRESSURE BUILDING INTO THE GREAT LAKES AREA AND THE STALLED BOUNDARY TO OUR SOUTH, WE WILL BE IN A MORE EASTERLY FLOW REGIME WITH MOSTLY CLOUDY SKIES. THIS WILL ALLOW US TO BE COOLER ACROSS THE AREA. TEMPERATURES WILL ONLY MAKE IT INTO THE 70S THROUGH THE REGION AND IT WILL TRULY FEEL LIKE FALL OUT THERE. MONDAY THROUGH TUESDAY...THE BOUNDARY REMAINS STALLED TO OUR SOUTH BUT AS WE HEAD INTO MONDAY, A WAVE DEVELOPS ALONG IT AND IT STARTS TO MOVE A BIT. IT CURRENTLY LOOKS LIKE THE WAVE HELPS MOVE THE FRONT SLIGHTLY NORTH AND THEN TO THE EAST, KEEPING THE MAIN BOUNDARY TO OUR SOUTH. COOLER TEMPERATURES WILL CONTINUE ON MONDAY AND TUESDAY WITH HIGHS INTO THE MID TO UPPER 70S, WITH SOME LOWER 80S POSSIBLE AS SKIES CLEAR OUT AND WE START TO SEE MORE SUNSHINE. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. ISOLATED TSRA WILL BE POSSIBLE THROUGH 00Z THIS EVENING. HOWEVER, THINK THE BULK OF THE THUNDERSTORM ACTIVITY SHOULD REMAIN WEST OF THE REGION. THE COVERAGE THROUGH THIS TIME IS TOO LIMITED TO MENTION IN MOST OF THE TAFS FOR NOW. STARTING AROUND 00Z, WE SHOULD SEE A LINE OF SHRA AND TSRA MOVE INTO THE REGION FROM THE WEST. HIGH RESOLUTION MODELS HAVE BEEN CONSISTENT IN SHOWING THIS GENERAL PATTERN AND TIMING. HOWEVER, THERE IS SOME QUESTION OF THE SOUTHERN EXTENT OF THE LINE (WHICH MAY NOT GO SOUTH OF PHL), AND IF THE LINE WILL START TO SCT BEFORE IT REACHES THE DELAWARE RIVER VALLEY. THEREFORE HAVE INCLUDED A TEMPO FOR THE SE PA SITES (KRDG AND KABE) AND KTTN WHERE THERE IS HIGHER CONFIDENCE, BUT ONLY HAVE MENTION OF VCSH FOR MOST OF THE REST OF THE SITES. ONCE THE FRONT MOVES THROUGH AFTER 06Z, EXPECT NORTHWESTERLY WINDS AND GENERALLY VFR CONDITIONS. THERE IS A SMALL RISK OF BR DEVELOPMENT BUT WITH DRY AIR ADVECTION BEHIND THE FRONT, THINK THIS IS UNLIKELY. OUTLOOK... WEDNESDAY NIGHT THROUGH FRIDAY... MAINLY VFR CONDITIONS EXPECTED. SOME FOG IS POSSIBLE WHICH MAY CAUSE MVFR/IFR CONDITIONS ON THU AND FRI MORNINGS. SATURDAY THROUGH SUNDAY...MAINLY VFR CONDITIONS EXPECTED WITH MVFR/IFR CONDITIONS POSSIBLE IN SHOWERS AND THUNDERSTORMS. && .MARINE... SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH TOMORROW. GUSTY WINDS WILL BE POSSIBLE IN THE VICINITY OF ANY THUNDERSTORMS THIS AFTERNOON AND TONIGHT. AN ABRUPT WIND SHIFT TO NORTHWESTERLY WINDS IS EXPECTED WITH A COLD FRONT THAT WILL MOVE THROUGH LATE TONIGHT. HOWEVER, WIND GUSTS SHOULD REMAIN WELL BELOW 20KT EVEN WITH THE FRONT. OUTLOOK... WEDNESDAY NIGHT THROUGH SUNDAY...SUB-ADVISORY CONDITIONS ARE EXPECTED. SOME STRONGER GUSTS AND HIGHER WAVES ARE POSSIBLE IN SHOWERS AND THUNDERSTORMS, MAINLY IN THE SATURDAY/SUNDAY TIMEFRAME. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...MEOLA NEAR TERM...JOHNSON SHORT TERM...JOHNSON LONG TERM...MEOLA AVIATION...JOHNSON/MEOLA MARINE...JOHNSON/MEOLA
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
400 PM EDT TUE SEP 2 2014 .SYNOPSIS... 19Z WATER VAPOR AND H4 RAP ANALYSIS SHOW THE MAIN NORTHERN STREAM FLOW FAR TO OUR NORTH ALONG THE CANADIAN BORDER AND OVER TOP AN ELONGATED WEST TO EAST ORIENTED UPPER RIDGE EXTENDING ACROSS THE SOUTHERN TIER OF THE CONUS. OUR FORECAST AREA RESIDES UNDER THIS LARGE UPPER RIDGE...HOWEVER A TUTT FEATURE RETROGRADING WESTWARD OVER THE BAHAMAS IS BEGINNING TO ERODE THE RIDGE TO OUR SOUTH AND EAST...AND WILL BEGIN TO BREAK DOWN THE RIDGE OVER OUR HEADS TONIGHT. 02/12Z SOUNDING PROFILE SHOWS THE INFLUENCE OF THE UPPER RIDGE OVERHEAD WITH A SUBSIDENCE INVERSION SIGNATURE AROUND 750MB. ABOVE THIS LAYER IT ON THE DRY SIDE. THE RESULTING PW IS LOW AROUND 1.7"...WHICH IS BELOW AVERAGE FOR EARLY SEPTEMBER...BUT NOT AN EXTREME VALUE. WE HAVE SEEN A BIT OF COOLING IN THE MID-LEVELS SINCE MONDAY...POSSIBLY THE VERY BEGINNING INFLUENCE OF THE APPROACHING TUTT. WILL EXPECT TO SEE ANOTHER DEGREE OR 2 OF COOLING IN THE MID-LEVELS OVER THE NEXT 24 HOURS AS THE TUTT PASSES JUST TO OUR SOUTH. THIS COOLING ALONG WITH OUR EVENTUAL POSITION ON THE EASTERN PERIPHERY OF THE TUTT (FAVORED FOR UPWARD MOTION AND CONVECTION) MAY LEAD TO ENHANCED CONVECTION LATER IN THE WEEK. SEA-BREEZE HAS MOVED INLAND TO AROUND I-75 FROM TAMPA BAY SOUTHWARD PER OBS AND RADAR ANALYSIS...BUT APPEARS TO BE PINNED VERY NEAR THE COAST UP ALONG THE NATURE COAST. THE 10 KNOTS OF EASTERLY FLOW JUST ABOVE THE SURFACE WILL KEEP THE INLAND PENETRATION SLOW THE NEXT FEW HOURS BEFORE THE EAST COAST SEA-BREEZE / CONVECTIVE OUTFLOWS COLLIDE WITH IT DURING THE EARLY EVENING. HAVE SEEN SOME SCT STORMS ALREADY FORM OVER THIS BOUNDARY AND DRIFT WESTWARD INTO THE POST SEA-BREEZE ENVIRONMENT. THIS IS UNLIKE YESTERDAY WHEN VERY LITTLE OCCURRED UNTIL THE MAIN COLLISION AND ALLOWED THE RELEASE OF ALL THE DAYS INSTABILITY. THEREFORE...THE POTENTIAL FOR EXPLOSIVE THUNDERSTORMS DEVELOPMENT THIS EVENING IS LOWER...BUT WILL STILL NEED TO BE WATCHED CLOSELY. ACROSS THE FAR SOUTHERN ZONES THE SHOWERS AND STORMS ARE FILLING IN AND RAIN CHANCES LOOKING QUITE LIKELY TO THE SOUTH OF SARASOTA OVER THE NEXT SEVERAL HOURS. STORM MOTION WILL BE WESTWARD AFTER INITIATION...SO MARINERS SHOULD CONTINUE TO BE AWARE OF THE WEATHER OVER LAND TO THEIR EAST AND BE PREPARED FOR STORMS TO RAPIDLY DEVELOP AND MOVE OFFSHORE. && .SHORT TERM (TONIGHT AND WEDNESDAY)... TONIGHT... THE ACTIVITY WILL ALL PUSH OFFSHORE WITHIN A COUPLE HOURS OF SUNSET AND PROVIDE THE REGION WITH A MOSTLY DRY AND SEASONABLE OVERNIGHT PERIOD. CAN NOT RULE OUT A FEW ISOLATED SHOWERS LATER TONIGHT ROTATING IN FROM THE EAST OVER CHARLOTTE/LEE COUNTY AS THE INFLUENCE OF THE TUTT INCREASES...BUT IMPACT SHOULD BE MINIMAL AND WILL LEAVE MENTION OUT OF THE FORECAST FOR NOW. WEDNESDAY... TUTT CELL MOVES OVER THE FLORIDA STRAITS AND SOUTH FLORIDA ENDING THE DOMINATION OF THE UPPER RIDGE ON THE FLORIDA PENINSULA. AT THE LOWER LEVELS THOUGH...WILL STILL BE DEALING WITH A LIGHT/MODERATE EASTERLY FLOW REGIME. THE MORNING HOURS WILL BE GENERALLY QUIET AND DRY IN TERMS OF WEATHER...BUT WE ARE LIKELY TO SEE CONVECTIVE INITIATION A BIT EARLIER THAN HAS BEEN THE CASE OVER RECENT DAYS AS THE LOSS OF LARGE SCALE SUBSIDENCE WILL PROMOTE A LOWER CONVECTIVE TEMPERATURE. WITH THE EARLIER INITIATION...THE PATTERN OF CONVECTION BECOME LESS EASY TO PUT DETAIL INTO AS THERE IS MORE TIME FOR NUMEROUS OUTFLOW BOUNDARIES TO DISRUPT THE LARGE SCALE FLOW. THEREFORE WILL KEEP HIGH END CHANCE 40-55% RAIN CHANCES IN AT MOST LOCATIONS...BUT WITH THE EASTERLY FLOW REGIME...WILL KEEP A TENDENCY FOR THE HIGHER RAIN CHANCES TO MIGRATE TOWARD THE WEST COAST WITH TIME DURING THE AFTERNOON AND EARLY EVENING. && .LONG TERM (WEDNESDAY NIGHT-TUESDAY)... MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH THE LONG TERM PERIODS. AN UPPER LEVEL TROUGH AND INCREASING DEEP LAYER MOISTURE WILL SPREAD NORTHWESTWARD ACROSS THE STATE ON THURSDAY AND FRIDAY...WITH WEAK UPPER LEVEL RIDGING THEN BUILDING INTO THE AREA OVER THE WEEKEND AND INTO EARLY NEXT WEEK. AT THE SURFACE...THE SUBTROPICAL RIDGE AXIS IS EXPECTED TO REMAIN NORTH OF THE FORECAST AREA THROUGH THE END OF THE WORK WEEK...WITH MODEL SOLUTIONS THEN SHOWING SOME DISAGREEMENT IN POSITIONING DETAILS OVER THE WEEKEND AND INTO EARLY NEXT WEEK. THE GFS AND CANADIAN SHOW THE RIDGE AXIS REMAINING NORTH OF THE FORECAST AREA...BUT THE ECMWF SHOWS IT SHIFTING SOUTHWARD INTO CENTRAL FLORIDA. OVERALL...TYPICAL SUMMERTIME WEATHER IS EXPECTED TO PREVAIL WITH SCATTERED TO NUMEROUS MAINLY AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS EXPECTED EACH DAY. HIGH TEMPERATURES WILL REMAIN CLOSE TO NORMAL THROUGH THE LONG TERM PERIOD. && .AVIATION... VFR CONDITIONS PREVAIL ACROSS THE REGION LATE THIS MORNING. BEGINNING TO SEE THE FIRST OF A CU FIELD BEGIN TO DEVELOP. SCT SHOWERS AND STORMS WILL BE MOVING EAST TO WEST ACROSS THE PENINSULA DURING THE AFTERNOON. KFMY/KRSW/KPGD WILL BE FIRST TO SEE THE STORMS IN THE VICINITY BY MID AFTERNOON. FURTHER NORTH AROUND THE TAMPA BAY TERMINALS STORMS ARE LIKELY TO BE LATER IN THE AFTERNOON AND EVENING HOURS. AWAY FROM ANY STORMS...VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. && .MARINE... EAST SOUTHEAST WINDS LESS THAN 15 KNOTS AND SEAS 2 FEET OF LESS WILL CONTINUE INTO NEXT WEEK AS HIGH PRESSURE OVER THE ATLANTIC PUSHES WEST OVER THE FLORIDA PENINSULA. THE SEA BREEZE WILL SET UP ALONG AND NEAR THE COAST EACH DAY ALLOWING FOR AN ONSHORE FLOW FROM THE SOUTHWEST TO NORTHWEST DIRECTION. SCATTERED SHOWERS AND STORMS WILL BE POSSIBLE EACH DAY DEVELOPING OVER LAND AND THEN PUSHING WESTWARD OVER THE COASTAL WATERS DURING THE EVENING HOURS. THE ONLY EXPECTED HAZARD WILL BE GUSTY WINDS AND HIGHER SEAS IN THE VICINITY OF THUNDERSTORMS. && .FIRE WEATHER... A RIDGE OF HIGH PRESSURE WILL REMAIN NORTH OF THE REGION FOR THE NEXT SEVERAL DAYS. THIS WILL RESULT IN EASTERLY WINDS WITH THE HIGHEST RAIN CHANCES ALONG THE I-75 EACH AFTERNOON. OTHER THAN THE DAILY STORMS...NO SIGNIFICANT FIRE WEATHER CONCERNS ARE EXPECTED. FOG POTENTIAL...PATCHY GROUND FOG COULD DEVELOP LATE EACH NIGHT...ESPECIALLY IN LOCATIONS THAT RECEIVE RAIN DURING THE PREVIOUS EVENING. HOWEVER...NO SIGNIFICANT FOG IS ANTICIPATED. && .PRELIMINARY POINT TEMPS/POPS... TPA 76 90 76 91 / 30 50 30 60 FMY 75 92 74 91 / 10 50 10 60 GIF 74 92 74 92 / 10 50 10 50 SRQ 74 92 73 91 / 30 40 30 60 BKV 71 91 71 92 / 20 50 30 60 SPG 79 91 78 90 / 30 40 30 60 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/AVIATION/FIRE WX...MROCZKA MARINE...MCKAUGHAN LONG TERM...JELSEMA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
346 PM EDT TUE SEP 2 2014 .SYNOPSIS... ISSUED AT 1051 AM EDT TUE SEP 2 2014 ISOLATED SHOWERS WILL CONTINUE THROUGH AFTERNOON BEFORE DIMINISHING AS HIGH PRESSURE SETTLES OVER THE REGION. CLOUD COVER WILL ALSO DIMINISH THROUGH THE AFTERNOON...ALLOWING HIGH TEMPERATURES TO CLIMB INTO THE UPPER 70S AND LOW 80S. EXPECT A QUIET NIGHT...WITH MOSTLY CLEAR SKIES AND LOWS IN THE 50S. AREAS OF FOG WILL DEVELOP TOWARDS WEDNESDAY MORNING...BECOMING LOCALLY DENSE AT TIMES. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 344 PM EDT TUE SEP 2 2014 INFILTRATION OF DRIER AIR INTO THE REGION HAS BEEN SLOW THIS AFTERNOON...WITH AMPLE BOUNDARY LAYER MOISTURE AMID WASHED OUT SURFACE BOUNDARY ACROSS THE FORECAST AREA. LOW CLOUDS HAVE BEEN SLOW TO MIX OUT THROUGH EARLY AFTERNOON BUT LATEST SAT TRENDS SHOWING MORE SCT LOW LVL CLOUD LAYER...ESPECIALLY NW. ISOLD SHOWERS CURRENTLY NOTED ON RADAR ACROSS NW/NC IN...GIVEN AMPLE BOUNDARY LAYER MOISTURE...WEAK SFC CONVERGENCE AND SFC HEATING YIELDING VERY MODEST SB CAPES UP TO 1000 J/KG ACROSS THE REGION. HRRR AND EVEN NAM12 HINTING AT ISOLD SHOWER ACTIVITY SPREADING EAST ACROSS THE FORECAST AREA THROUGH SUNSET. THEREFORE HAVE KEPT AN ISOLD SHOWER MENTION THROUGH 00Z IN THE FCST. LOW CONFIDENCE FOR THUNDER AT THIS TIME GIVEN LACK OF FORCING AND WEAK MID LVL LAPSE RATES. AS RIDGING BUILDS EASTWARD INTO THE OVERNIGHT HOURS...CLEARING SKIES AND DRY CONDITIONS EXPECTED. WITH SLACKENING GRADIENT AND LOW LVL MOISTURE...ESPECIALLY SE W/ THE PRECIP OVER THE PAST 24 HRS...FOG DEVELOPMENT LOOKS LIKELY LATE IN THE OVERNIGHT INTO DAYBREAK WEDNESDAY. KEPT PREVIOUS FCST IN TACT WITH AREAS OF FOG MENTION FROM 09-12Z. LOW CONFIDENCE WITH THE POSSIBILITY OF DENSE FOG AT THIS TIME...GIVEN LOW LEVEL DRY ADVECTION AND EXTENSIVE CIRRUS SHIELD NOTED ACROSS THE SOUTHWEST HALF OF THE FORECAST AREA THIS AFTERNOON. IF CLOUD COVER IS QUICK TO DIMINISH TONIGHT...W/ LACK OF ANY CONVECTIVE DEBRIS...THEN DENSE FOG CHANCES WOULD INCREASE TOWARD TOMORROW MORNING...ESPECIALLY SE. WILL MONITOR TRENDS THROUGH THE EVENING AND WILL UPDATE AS NECESSARY. RIDGING BUILDS EAST OF THE AREA THROUGH THE DAY ON WEDNESDAY...WITH MOSTLY SUNNY SKIES AND FAIR CONDITIONS. KEPT HIGH TEMPS SLIGHTLY BELOW MAV...ALTHOUGH UPWARD ADJUSTMENT MAY BE NEEDED IN THE NEXT FCST WITH WAA INTO THE AREA BY THE AFTERNOON HOURS ON THE WESTERN PERIPHERY OF THE RIDGE. && .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 344 PM EDT TUE SEP 2 2014 THE GFS AND ECMWF HAVE APPEARED TO INITIALIZE THE UPSTREAM SHORT WAVE WELL AND ALSO SEEM HAVE A REASONABLE TRACK WITH THIS SYSTEM ACROSS THE CONUS THIS WEEK. THE ECMWF AND GFS HAVE ALSO SHOWN GOOD CONSISTENCY FROM RUN TO RUN WITH THIS SYSTEM THE PAST SEVERAL RUNS. LOW LEVEL THETA E AND MOISTURE FLUX WILL INCREASE RAPIDLY WEDNESDAY NIGHT...ESPECIALLY NORTH AND NORTHWEST OF THE AREA. HAVE ADDED A SMALL CHANCE FOR THUNDERSTORMS OVERNIGHT WEDNESDAY NIGHT ON THE LEADING EDGE OF THIS THETA E ADVECTION OVER FAR NORTHWEST AREAS... ESPECIALLY BERRIEN AND LAPORTE COUNTY. KEPT THURSDAY DRY AS THE PRIMARY LOW LEVEL FORCING SHIFTS NORTH OF THE AREA AND AS A LOW LEVEL INVERSION INCREASES AT THE BASE OF A WEAK TO MODERATE ELEVATED MIXED LAYER. THE GFS MAV/MEX TEMPERATURES HAVE BEEN CONSISTENT AT GENERALLY 5 TO 10 DEGREES ABOVE NORMAL FOR THURSDAY AND FRIDAY AND APPEAR ON TRACK WITH 850 MB TEMPERATURES APPROACHING 20C. THUNDERSTORM CHANCES LOOK BEST OVERNIGHT THURSDAY NIGHT THROUGH FRIDAY NIGHT AS A COLD FRONT APPROACHES. GIVEN THE TIMING OF THE FRONT AND SUBSTANTIAL INSTABILITY BY LATE THURSDAY AND FRIDAY AFTERNOON/EARLY EVENING WITH CAPES AS HIGH AS 2000 TO 3000 J/KG...CONCERN FOR AN UPSTREAM CONVECTIVE COMPLEX TO DROP SOUTHEAST OR SOUTH INTO THE FORECAST AREA AS RICH THETA E SPREADS OVER THE AREA. EXPANDED THUNDERSTORM CHANCES THURSDAY NIGHT IN THIS REGARD. OTHERWISE...KEPT STORM CHANCES FRIDAY AND FRIDAY NIGHT. OTHERWISE... COOLER AND DRIER CONDITIONS CAN BE EXPECTED FOR THE WEEKEND INTO NEXT WEEK WITH HIGHS IN THE 70S THROUGH TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 128 PM EDT TUE SEP 2 2014 DIFFUSE FRONTAL BOUNDARY PUSHING SOUTH THROUGH THE AREA AND UPPER LEVEL SUPPORT SHIFTING NORTHEAST OF THE REGION THIS AFTERNOON SHOULD YIELD IMPROVING CONDITIONS AT TERMINALS THROUGH THE FIRST HALF OF THE TAF PD. LINGERING LOW LEVEL STRATUS SLOW TO MIX OUT THROUGH MIDDAY...ESPECIALLY INVOF KFWA. BUT RECENT SATELLITE TRENDS SUGGEST RAPID MIXING AND LIFTING/CLEARING OF ANY MVFR CIGS THIS AFTERNOON. RIDGING BUILDS IN OVERNIGHT WITH CALMING WINDS AND CLEARING SKIES. LEFT PREVIOUS FCST IN TACT WITH POTENTIAL FOR MVFR/IFR FOG TOWARD DAYBREAK WEDNESDAY MORNING. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...MCD SHORT TERM...NG LONG TERM...SKIPPER AVIATION...NG VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
401 PM CDT TUE SEP 2 2014 ...UPDATED FOR LONG TERM... .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 344 PM CDT TUE SEP 2 2014 THE MID TO UPPER LEVEL FLOW HAS BECOME ZONAL IN THE WAKE OF THE MINOR SHORTWAVE TROUGH THAT TRAVERSED THE CENTRAL PLAINS MONDAY EVENING. THE EFFECTIVE FRONTAL BOUNDARY AFTER ALL OF THE NIGHTTIME CONVECTION WAS SITUATED ACROSS CENTRAL OKLAHOMA AND SOUTHERN ARKANSAS. SOUTH OF THIS FRONT, TEMPERATURES WERE ABOVE 90 AS OF 2 PM, BUT ON THE COOL SIDE OF THE FRONT, MOST READINGS WERE IN THE 70S TO LOWER 80S. LEE TROUGHING WILL DEVELOP TONIGHT AND WEDNESDAY IN RESPONSE TO THE ZONAL FLOW. LATE TONIGHT, WARMER MID LEVEL TEMPERATURES WILL SPREAD ACROSS SOUTHWEST KANSAS, CAPPING THE ELEVATED MOIST LAYER. THE NAM INDICATES THAT LOW LEVEL WINDS WILL BECOME SOUTHERLY AS THE WARM FRONT SHIFTS INTO NORTHERN KANSAS BY WEDNESDAY MORNING. HOWEVER, THE RAP SHOWS THE BOUNDARY STILL SITUATED ALONG THE KANSAS/OKLAHOMA BORDER AT 12Z. SINCE WE MAY MAINTAIN UPSLOPE SOUTHEASTERLY FLOW MOST OF THE NIGHT, I OPTED TO BRING THE LOW CLOUDS AND FOG BACK IN TOWARD 09Z. A MID LEVEL CLOUD DECK MAY DEVELOP AS THE LOW LEVEL JET DEVELOPS THIS EVENING AND AN ELEVATED THUNDERSTORM OR TWO CAN`T BE COMPLETELY RULED OUT OVER SOUTH CENTRAL KANSAS BEFORE THE STRONG CAPPING INVERSION DEVELOPS. ON WEDNESDAY, THE LEE TROUGH WILL BECOME ESTABLISHED ACROSS THE HIGH PLAINS, WITH A WEAK SURFACE DRYLINE SITUATED ACROSS FAR WESTERN KANSAS. AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT LATE IN THE DAY. HIGH TEMPERATURES WILL BE IN THE MID TO HIGH 90S,WITH SOME READINGS CLOSE TO 100F. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 357 PM CDT TUE SEP 2 2014 A STRONG UPPER LEVEL SHORTWAVE TROUGH OVER THE PACIFIC NORTHWEST WILL MOVE EASTWARD INTO THE NORTHERN PLAINS AND UPPER MIDWEST BY FRIDAY. THIS SYSTEM WILL PUSH A COLD FRONT ACROSS WESTERN KANSAS AND THE CENTRAL PLAINS ON THURSDAY BRINGING THE BEST CHANCES FOR SHOWERS AND THUNDERSTORMS. THE STRONGEST MID AND UPPER LEVEL WINDS WILL BE IN NEBRASKA, SO NOT EXPECTING LOTS OF SEVERE WITH THE FRONT. CAPE VALUES AROUND 2000 J/KG WILL BE SUFFICIENT TO PRODUCE SOME SMALL HAIL AND STRONG WINDS AS THE COLD FRONT SWEEPS ACROSS WESTERN KANSAS TO NEAR DODGE CITY BY 7 PM THURSDAY AND THROUGH MEDICINE LODGE BY AROUND MIDNIGHT. HIGH TEMPERATURES WILL BE VERY WARM AHEAD OF THE COLD FRONT ON THURSDAY WITH LOW TO MID AND UPPER 90S FORECAST. HIGHS THEN COOL INTO THE 70S INTO FRIDAY WITH A CONTINUED CHANCE FOR MAINLY AFTERNOON THUNDERSTORMS BEHIND THE FRONT IN MOIST SURFACE UPSLOPE FLOW. BY MONDAY HIGHS WARM BACK INTO THE 80S AS THE COOL HIGH PRESSURE AREA MOVES EAST AND WARM SOUTHERLY WINDS INCREASE. MORE THUNDERSTORM CHANCES CONTINUE INTO TUESDAY WITH DISTURBANCES IN SOUTHWEST FLOW ALOFT AND UPPER JET. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1241 PM CDT TUE SEP 2 2014 ZONAL FLOW IN THE WAKE OF AN UPPER LEVEL DISTURBANCE WILL LEAD TO RENEWED LEE TROUGHING AND A RETURN TO SOUTHERLY WINDS. AS A RESULT, THE WARM FRONT OVER OKLAHOMA WILL ADVANCE NORTHWARD INTO NORTHERN KANSAS TONIGHT. CIGS WILL GRADUALLY IMPROVE AT GCK/DDC TO VFR THIS AFTERNOON WITH DAYTIME HEATING. GIVEN THE LACK OF UPSLOPE COMPONENT TO THE WIND LATER TONIGHT, A RETURN TO LOW CIGS AND FOG IS NOT EXPECTED. THE RAP NOW INDICATES THAT LOW LEVEL SOUTHEAST FLOW WILL PERSIST THROUGH 12Z, AND THUS LIFR/IFR CIGS AND VISBYS MAY DEVELOP BY 09Z. && .PRELIMINARY POINT TEMPS/POPS... DDC 70 97 72 95 / 10 0 10 30 GCK 68 99 70 92 / 0 0 10 40 EHA 66 99 68 94 / 0 10 10 30 LBL 70 98 71 96 / 0 0 10 20 HYS 68 98 72 92 / 10 10 10 50 P28 72 97 74 97 / 30 10 10 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...FINCH LONG TERM...KRUSE AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
351 PM CDT TUE SEP 2 2014 ...UPDATED FOR SHORT TERM DISCUSSION... .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 344 PM CDT TUE SEP 2 2014 THE MID TO UPPER LEVEL FLOW HAS BECOME ZONAL IN THE WAKE OF THE MINOR SHORTWAVE TROUGH THAT TRAVERSED THE CENTRAL PLAINS MONDAY EVENING. THE EFFECTIVE FRONTAL BOUNDARY AFTER ALL OF THE NIGHTTIME CONVECTION WAS SITUATED ACROSS CENTRAL OKLAHOMA AND SOUTHERN ARKANSAS. SOUTH OF THIS FRONT, TEMPERATURES WERE ABOVE 90 AS OF 2 PM, BUT ON THE COOL SIDE OF THE FRONT, MOST READINGS WERE IN THE 70S TO LOWER 80S. LEE TROUGHING WLLL DEVELOP TONIGHT AND WEDNESDAY IN RESPONSE TO THE ZONAL FLOW. LATE TONIGHT, WARMER MID LEVEL TEMPERATURES WILL SPREAD ACROSS SOUTHWEST KANSAS, CAPPING THE ELEVATED MOIST LAYER. THE NAM INDICATES THAT LOW LEVEL WINDS WILL BECOME SOUTHERLY AS THE WARM FRONT SHIFTS INTO NORTHERN KANSAS BY WEDNESDAY MORNING. HOWEVER, THE RAP SHOWS THE BOUNDARY STILL SITUATED ALONG THE KANSAS/OKLAHOMA BORDER AT 12Z. SINCE WE MAY MAINTAIN UPSLOPE SOUTHEASTERLY FLOW MOST OF THE NIGHT, I OPTED TO BRING THE LOW CLOUDS AND FOG BACK IN TOWARD 09Z. A MID LEVEL CLOUD DECK MAY DEVELOP AS THE LOW LEVEL JET DEVELOPS THIS EVENING AND AN ELEVATED THUNDERSTORM OR TWO CAN`T BE COMPLETELY RULED OUT OVER SOUTH CENTRAL KANSAS BEFORE THE STRONG CAPPING INVERSION DEVELOPS. ON WEDNESDAY, THE LEE TROUGH WILL BECOME ESTABLISHED ACROSS THE HIGH PLAINS, WITH A WEAK SURFACE DRYLINE SITUATED ACROSS FAR WESTERN KANSAS. AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT LATE IN THE DAY. HIGH TEMPERATURES WILL BE IN THE MID TO HIGH 90S,WITH SOME READINGS CLOSE TO 100F. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 326 AM CDT TUE SEP 2 2014 THE LONGWAVE SYNOPTIC FLOW PATTERN WILL BE SOMEWHAT PROGRESSIVE THROUGH THIS FORECAST, AT LEAST ENOUGH TO BRING SIGNIFICANT SENSIBLE WEATHER CHANGES TO THE AREA FOR LATE IN THE WEEK. WEDNESDAY AND THURSDAY WILL SEE SUNNY AND VERY WARM TO HOT TEMPERATURES, AS THE UPPER JET LIFTS NORTHWARD ACROSS THE NORTHERN TIER OF STATES ALLOWING THE LARGE SOUTHERN ROCKIES/SOUTHERN PLAINS HIGH PROVIDE STRONG SUBSIDENCE, FULL INSOLATION AND SOUTHERLY SURFACE WINDS. THE ECMWF/GFS AND NAM ARE IN EXCELLENT AGREEMENT IN BREAKING DOWN THIS PATTERN BY THURSDAY AND BRINGING A COLD FRONT THROUGH THE NORTHERN PLAINS OF WESTERN NEBRASKA AND AS FAR SOUTH AS WEST CENTRAL KANSAS WITH THE LEADING COOLER AIR SURGE BY THURSDAY AFTERNOON. CONVECTION COULD OCCUR LATE THURSDAY AFTERNOON OR EVENING AS WELL WITH THIS COLD FRONT FEATURE, BUT UPPER SUPPORT/DYNAMICS FOR WIDESPREAD STORM DEVELOPMENT IS LACKING. THE UPPER JET WILL SINK SOUTHWARD THROUGH THE CENTRAL PLAINS AND CENTRAL MISSISSIPPI VALLEY, DRIVING THE COLD FRONT FARTHER SOUTH INTO THE SOUTHERN PLAINS BY SATURDAY MORNING. THE RESULT WILL BE ADDITONAL CHANCES FOR POSSIBLY EVEN SEVERE STORMS, BUT PERHAPS JUST POST SURFACE FRONTAL HIGH BASED CONVECTION FROM MID LEVEL FRONTOGENESIS FRIDAY OR FRIDAY NIGHT WITH MUCH MORE PLEASANT TEMPERATURES IN THE 70S. A SLOW WARMING TREND IS LIKELY THROUGH THE LATE PART OF THE WEEKEND INTO EARLY NEXT WEEK AS RETURN SOUTHERLY FLOW BECOMES REESTABLISHED. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1241 PM CDT TUE SEP 2 2014 ZONAL FLOW IN THE WAKE OF AN UPPER LEVEL DISTURBANCE WILL LEAD TO RENEWED LEE TROUGHING AND A RETURN TO SOUTHERLY WINDS. AS A RESULT, THE WARM FRONT OVER OKLAHOMA WILL ADVANCE NORTHWARD INTO NORTHERN KANSAS TONIGHT. CIGS WILL GRADUALLY IMPROVE AT GCK/DDC TO VFR THIS AFTERNOON WITH DAYTIME HEATING. THE RAP NOW INDICATES THAT LOW LEVEL SOUTHEAST FLOW WILL PERSIST THROUGH 12Z, AND THUS LIFR/IFR CIGS AND VISBYS MAY DEVELOP BY 09Z. && .PRELIMINARY POINT TEMPS/POPS... DDC 70 97 72 95 / 10 0 10 30 GCK 68 99 70 92 / 0 0 10 40 EHA 66 99 68 94 / 0 10 10 30 LBL 70 98 71 96 / 0 0 10 20 HYS 68 98 72 92 / 10 10 10 50 P28 72 97 74 97 / 30 10 10 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...FINCH LONG TERM...RUSSELL AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1247 PM CDT TUE SEP 2 2014 ...UPDATED FOR AVIATION DISCUSSION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 357 AM CDT TUE SEP 2 2014 AS OF 0845 UTC, STRONG THUNDERSTORMS WERE UNDERWAY ACROSS COMANCHE, BARBER, AND CLARK COUNTY, TIED MOST CLOSELY TO A ZONE OF FRONTOGENESIS AT AROUND 750MB STRETCHING FROM THE OKLAHOMA PANHANDLE EAST- NORTHEASTWARD TO FAR SOUTH-CENTRAL KANSAS. THE HIRES CONVECTIVE- ALLOWING MODELS PICKED UP ON THIS QUITE WELL IN THE COMPOSITE REFLECTIVITY AND QPF FIELDS. THESE MODELS SHOW THE CONVECTION MOVING OFF INTO NORTHERN OKLAHOMA BEFORE 1200 UTC, SO WE WILL TAPER THE POPS DOWN AROUND THIS TIME. EARLIER IN THE SHIFT, WE ADDED SOME AREAS OF 1/2SM FOG GENERALLY ALONG/SOUTH OF THE ARKANSAS RIVER IN A ZONE OF SATURATED SURFACE AIR NORTH OF THE WEAK SURFACE LOW. ANY FOG WHICH DEVELOPS SHOULD ERODE NOT TOO LONG AFTER SUNRISE, HOWEVER LOW STRATUS IS EXPECTED TO HOLD ON THROUGH LATE MORNING NORTH OF THE 850MB LOW. THIS MAY THROW A BIT OF A CURVE BALL IN THE TEMPERATURES TODAY, SO WE ADJUSTED THEM DOWN (USING A MODIFIED HRRR SOLUTION) OUT ACROSS THE WESTERN HALF FOR THE FIRST HALF OF THE DAY WITH CLOUDS KEEPING A LID IN THE WARM- UP. ONCE THE CLOUDS ERODE COMPLETELY BY MIDDAY/EARLY AFTERNOON, TEMPERATURES WILL WARM INTO THE MID 80S. ANY SURFACE-BASED CONVECTION LATE THIS AFTERNOON WILL BE DOWN ALONG THE SURFACE FRONT ACROSS NORTHWEST OKLAHOMA. BY EARLY EVENING, SOME OF THE THUNDERSTORM ACTIVITY MAY HEAD UP INTO BARBER COUNTY AND EXPAND IN COVERAGE SOME AS LOW LEVEL JET STRENGTHENS AFTER SUNSET. RICH LOW LEVEL MOISTURE LEADING TO 2000-3000 J/KG MOST-UNSTABLE CAPE WILL SUPPORT RENEWED SEVERE WEATHER RISK, EVEN WITH ELEVATED STORMS DURING THE LATE NIGHT HOURS TONIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 326 AM CDT TUE SEP 2 2014 THE LONGWAVE SYNOPTIC FLOW PATTERN WILL BE SOMEWHAT PROGRESSIVE THROUGH THIS FORECAST, AT LEAST ENOUGH TO BRING SIGNIFICANT SENSIBLE WEATHER CHANGES TO THE AREA FOR LATE IN THE WEEK. WEDNESDAY AND THURSDAY WILL SEE SUNNY AND VERY WARM TO HOT TEMPERATURES, AS THE UPPER JET LIFTS NORTHWARD ACROSS THE NORTHERN TIER OF STATES ALLOWING THE LARGE SOUTHERN ROCKIES/SOUTHERN PLAINS HIGH PROVIDE STRONG SUBSIDENCE, FULL INSOLATION AND SOUTHERLY SURFACE WINDS. THE ECMWF/GFS AND NAM ARE IN EXCELLENT AGREEMENT IN BREAKING DOWN THIS PATTERN BY THURSDAY AND BRINGING A COLD FRONT THROUGH THE NORTHERN PLAINS OF WESTERN NEBRASKA AND AS FAR SOUTH AS WEST CENTRAL KANSAS WITH THE LEADING COOLER AIR SURGE BY THURSDAY AFTERNOON. CONVECTION COULD OCCUR LATE THURSDAY AFTERNOON OR EVENING AS WELL WITH THIS COLD FRONT FEATURE, BUT UPPER SUPPORT/DYNAMICS FOR WIDESPREAD STORM DEVELOPMENT IS LACKING. THE UPPER JET WILL SINK SOUTHWARD THROUGH THE CENTRAL PLAINS AND CENTRAL MISSISSIPPI VALLEY, DRIVING THE COLD FRONT FARTHER SOUTH INTO THE SOUTHERN PLAINS BY SATURDAY MORNING. THE RESULT WILL BE ADDITONAL CHANCES FOR POSSIBLY EVEN SEVERE STORMS, BUT PERHAPS JUST POST SURFACE FRONTAL HIGH BASED CONVECTION FROM MID LEVEL FRONTOGENESIS FRIDAY OR FRIDAY NIGHT WITH MUCH MORE PLEASANT TEMPERATURES IN THE 70S. A SLOW WARMING TREND IS LIKELY THROUGH THE LATE PART OF THE WEEKEND INTO EARLY NEXT WEEK AS RETURN SOUTHERLY FLOW BECOMES REESTABLISHED. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1241 PM CDT TUE SEP 2 2014 ZONAL FLOW IN THE WAKE OF AN UPPER LEVEL DISTURBANCE WILL LEAD TO RENEWED LEE TROUGHING AND A RETURN TO SOUTHERLY WINDS. AS A RESULT, THE WARM FRONT OVER OKLAHOMA WILL ADVANCE NORTHWARD INTO NORTHERN KANSAS TONIGHT. CIGS WILL GRADUALLY IMPROVE AT GCK/DDC TO VFR THIS AFTERNOON WITH DAYTIME HEATING. GIVEN THE LACK OF UPSLOPE COMPONENT TO THE WIND LATER TONIGHT, A RETURN TO LOW CIGS AND FOG IS NOT EXPECTED. && .PRELIMINARY POINT TEMPS/POPS... DDC 84 68 98 71 / 10 10 0 0 GCK 82 67 100 71 / 10 0 0 10 EHA 85 66 99 69 / 0 0 10 10 LBL 86 69 100 72 / 0 10 0 10 HYS 86 67 99 73 / 0 10 10 10 P28 89 72 98 74 / 40 30 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...UMSCHEID LONG TERM...RUSSELL AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS JACKSON KY
345 PM EDT TUE SEP 2 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 343 PM EDT TUE SEP 2 2014 A LINE OF THUNDERSTORMS WITH HEAVY RAINS HAS FORMED ALONG AN OLD OUTFLOW BOUNDARY ACROSS THE MID SECTION OF EASTERN KENTUCKY. SOME OF THE STORMS HAVE BECOME NEAR SEVERE AND EXPECT SOME SEVERE STORM WARNINGS TO BE ISSUED DURING THE NEXT FEW HOURS. THE MAIN THREAT WILL BE WIND GUSTS. ANOTHER CONCERN IS THAT WITH UNIDIRECTIONAL FLOW AND HIGH PRECIPITABLE WATER...FLOODING CONCERNS WILL BE A REAL ISSUE THIS AFTERNOON AND EVENING...MAINLY IN THE SOUTHERN HALF OF EASTERN KENTUCKY AND ESPECIALLY ALONG THE OLD OUTFLOW BOUNDARY. EXPECT THE FRONT TO PUSH THE PRECIPITATION SOUTH OF THE AREA BY WEDNESDAY MORNING. IN GENERAL...THE HRRR AND RAP HAVE NOT BEEN DOING TOO WELL WITH THIS SYSTEM SO FAR. WEDNESDAY FIGURES TO BE A LITTLE MORE COMFORTABLE AS THE HUMIDITY WILL BE A LITTLE LOWER. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 301 PM EDT TUE SEP 2 2014 THE MODELS BEGIN THE EXTENDED PERIOD IN PRETTY GOOD AGREEMENT ONCE AGAIN...WITH A RIDGE OF HIGH PRESSURE...BOTH ALOFT AND AT THE SURFACE...CENTERED OVER THE EASTERN GULF OF MEXICO...ALONG WITH A WELL DEFINED TROUGH OF LOW PRESSURE ALOFT TAKING SHAPE OVER THE NORTHERN PLAINS. THE MODELS HAVE THE RIDGE STEADILY BREAKING DOWN TO BEGIN THE PERIOD...WITH SHOWERS AND STORMS POPPING UP BENEATH IT ACROSS THE TENNESSEE VALLEY DOWN TO THE GULF AND ACROSS PORTIONS OF THE SOUTHEASTERN CONUS. AS THE TROUGH EVOLVES AND STRENGTHENS...IT WILL EJECT OUT OF THE PLAINS WEDNESDAY AND THURSDAY...AND PUSH ACROSS THE GREAT LAKES AND OHIO VALLEY REGIONS. THE COLD FRONT TRAILING FROM THIS UPPER LOW WILL END UP BEING OUR WEATHER MAKER FOR THE UPCOMING WEEKEND. THE FRONT IS EXPECTED TO INTERACT WITH MOISTURE COMING OFF THE GULF OF MEXICO ON SOUTHWESTERLY WINDS. THE FRONT WILL HAVE A DIFFICULT TIME MOVING EASTWARD...HOWEVER...AS THE RIDGE DIGS IN A BIT JUST OFF THE SOUTHEAST COAST AND FLOW ALOFT BECOMES MORE ZONAL. THERE WILL BE A GOOD CHANCE OF RAIN FRIDAY MORNING THROUGH SUNDAY MORNING...AS LIFT AND MOISTURE ALONG THE SLUGGISH FRONT SET OFF REPEATED ROUNDS OF SHOWERS AND STORMS. THE RAIN SHOULD FINALLY MOVE OUT OF THE AREA SUNDAY EVENING...AS THE FRONT FINALLY MOVES OUT OF THE AREA. TEMPERATURES TO BEGIN THE PERIOD LOOK TO BE ABOVE NORMAL...WITH HIGHS TOPPING OUT AROUND IN THE MID TO UPPER 80S THURSDAY AND FRIDAY. ONCE THE FRONT STALLS ACROSS THE AREA AND PRECIPITATION BECOMES MORE WIDESPREAD...TEMPERATURES WILL LIKELY MAX OUT BELOW NORMAL VALUES SATURDAY THROUGH MONDAY. THE POSITIONING OF THE FRONT OVER THE WEEKEND WILL ALLOW FOR SOME COOLER AND DRIER AIR TO FILTER INTO THE AREA. HIGHS ON SATURDAY SHOULD BE JUST BELOW NORMAL...AS THE BULK OF COOL AIR SHOULD STILL BE TRAPPED NORTH OF THE OHIO RIVER. ON SUNDAY...HOWEVER...ONCE WINDS HAVE SHIFTED TO THE NORTH...TEMPERATURES WILL BE QUITE COOL...WITH READINGS PEAKING IN THE MID TO UPPER 70S FOR MOST LOCATIONS. THE NORTHERLY FLOW WILL ONLY ALLOW FOR A SMALL WARM UP ON MONDAY...AS HIGHS THAT DAY WILL LIKELY ONLY TOP OUT IN THE UPPER 70S AND LOWER 80S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 156 PM EDT TUE SEP 2 2014 EASTERN KENTUCKY IS PRIMED FOR THUNDERSTORMS AS MOIST AND UNSTABLE CONDITIONS ARE PREVALENT ACROSS THE AREA. THERE IS AN OLD OUTFLOW BOUNDARY BISECTING THE AREA WHICH WE ARE WATCHING AS A FOCAL POINT FOR CONVECTIVE INITIATION AND THERE IS ALSO A FRONT WHICH IS MOVING TOWARD THE AREA FROM THE NORTHWEST WITH LOTS OF PREFRONTAL CONVECTION OUT AHEAD OF IT. MAINLY VFR CONDITIONS ARE EXPECTED AT THE TAF SITES THIS AFTERNOON AND EVENING EXCEPT FOR IN THE VICINITY OF THE THUNDERSTORMS AND RAIN SHOWERS. PUT SOME TEMPO CONDITIONS IN THE TAF AS THE BEST ESTIMATE AS TO WHEN THUNDERSTORMS ARE MOST LIKELY AFFECT THEM. EXPECT SOME VLIFR TO FORM AT THE TAF STATIONS AS WELL AS THE VALLEYS LATER THIS EVENING AS THE CONVECTION MOVES OFF TO THE SOUTH AND EAST. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JJ LONG TERM...AR AVIATION...JJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
302 PM EDT TUE SEP 2 2014 .UPDATE... ISSUED AT 948 AM EDT TUE SEP 2 2014 THE FORECAST FOR THIS AFTERNOON HAS BECOME COMPLICATED BY THE REMNANTS OF AN MCS OVER THE OHIO VALLEY AND THE OUTFLOW BOUNDARY WHICH IS CURRENTLY MOVING INTO THE BLUEGRASS. CURRENT THINKING IS THAT THE OUTFLOW BOUNDARY WILL GENERALLY WEAKEN AS IT CONTINUES MOVING TO THE SOUTHEAST. THIS SHOULD BE TEMPORARY AND WILL THEN BE THE FOCUS OF DEVELOPMENT LATER IN THE AFTERNOON. SO PRETTY MUCH GOING WITH TWO PRONGS. THE FIRST BEING REDEVELOPMENT WITH THE OUTFLOW BOUNDARY AND THE SECOND BEING THE PREFRONTAL ACTIVITY. THE SEVERE THREAT TODAY WILL BE EFFECTED BY HOW MUCH DEBRIS CLOUD IS ABLE TO MOVE INTO THE AREA. THE LOW LEVEL INSTABILITY WILL BE EFFECTED BY EFFECTED BY THE CLOUDS. THE LATEST NAM BUFFER HAS REALLY BACKED OFF FROM YESTERDAY WITH HALF THE CAPE THAN WHAT WAS FORECAST YESTERDAY. ALSO MISSING IS THE DRY AIR POCKETS ALOFT WHICH WOULD HAVE BEEN HELPFUL FOR WET MICROBURSTS TO OCCUR. CAN NOT RULE OUT SEVERE THUNDERSTORMS...HOWEVER THE CHANCES HAVE GONE DOWN. MOST LIKELY WILL STILL SEE A COUPLE OF SEVERE STORMS WITH THIS SYSTEM. UPDATED THE FORECAST TO REFLECT THE CURRENT CONDITIONS AND MODEL TRENDS. UPDATE ISSUED AT 649 AM EDT TUE SEP 2 2014 NO SIGNIFICANT CHANGES MADE THIS MORNING. LINE OF SHOWERS AND STORMS EXTENDS FROM CINCINNATI SOUTHWEST TO THE NORTHWEST SIDE OF LOUISVILLE. THIS LINE CONTINUES TO SLOWLY WEAKEN AS IT MOVES EAST. IF IT WERE TO HOLD TOGETHER...LOOKS LIKE IT MAY WORK INTO THE BLUEGRASS COUNTIES AFTER 13Z. HOWEVER...GIVEN THE TREND THIS SEEMS UNLIKELY AND AT BEST PERHAPS AN ISOLATED SHOWER CAN HOLD TOGETHER. MAIN CONCERN CONTINUES TO BE LATER TODAY...PRIMARILY AFTER 2 PM AS OUTFLOW FROM THIS MORNINGS CONVECTION REDEVELOPS SHOWERS AND STORMS. NOT SURE THE COVERAGE WILL BE ALL THAT GREAT AFTER LOOKING AT THE LATEST HRRR AND NEW 06Z MAV GUIDANCE. BOTH OF THESE MODELS HAVE BACKED OFF SIGNIFICANTLY ON THE CHANCES OF RAIN TODAY. HOWEVER...GOING TO STAY THE COURSE AS THE TROUGH IS STILL FAIRLY DEFINED AND OUTFLOW HAS ALREADY DEFINED A BOUNDARY FOR NEW CONVECTION TO DEVELOP. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 330 AM EDT TUE SEP 2 2014 PRESENTLY...A SHORTWAVE TROUGH IS PUSHING INTO THE OHIO RIVER VALLEY REGION. AN MCS DEVELOPED YESTERDAY EVENING HEAD OF THIS TROUGH AND IS NOW MARCHING EASTWARD INTO CENTRAL/SOUTHERN INDIANA...STRETCHING BACK TO THE SOUTHWEST ACROSS SOUTHERN ILLINOIS. IR SATELLITE HAS SHOWN SOME WARMING WITH THE CLOUD TOPS OVER THE PAST HOUR OR TWO...INDICATING THAT THIS MCS MAY ALREADY BE ON THE DECLINE. IN FACT...THE HRRR SUPPORTS THE IDEA OF A DYING MCS AS IT TRIES TO PUSH INTO CENTRAL KENTUCKY TOWARDS DAYBREAK. CANNOT RULE OUT A FEW SHOWERS PUSHING INTO THE BLUEGRASS SHORTLY AFTER 8 AM...BUT ANTICIPATE MORE OF THE ACTION WITH THE SHORTWAVE TROUGH WILL COME LATER THIS AFTERNOON AS WE GENERATE SOME INSTABILITY. WITH THIS IN MIND...PLAN TO BACK OFF THE POPS THROUGH MIDDAY WITH JUST SOME ISOLATED SHOWERS FOR AREAS NORTH OF I-64. OUTFLOW FROM THE DYING MCS WILL BE PUSHING ACROSS EASTERN KENTUCKY EARLY THIS AFTERNOON...AND COULD KICK START THE CONVECTION AS IT ENCOUNTERS SOME DECENT INSTABILITY. THE FORCING ALOFT SHOULD ALLOW FOR FAIRLY GOOD SHOWER AND THUNDERSTORM COVERAGE BY MID TO LATE AFTERNOON. WITH BULK SHEAR VALUES OF 30-40KTS THIS AFTERNOON...A SEVERE THREAT WOULD EXIST AS THUNDERSTORMS COULD PUT OUT SOME DAMAGING WIND GUSTS. THE SHEAR PROFILES WEAKEN BY MID EVENING AND THE LOSS OF DAYTIME INSTABILITY SHOULD YIELD WEAKENING STORMS AFTER 6 PM. HOWEVER...A FEW GUSTY WINDS MAY STILL BE POSSIBLE THROUGH 8 OR 9 PM. THE SHORTWAVE TROUGH WILL STALL A COLD FRONT ACROSS SOUTHERN KENTUCKY BY LATE THIS EVENING. GIVEN THE PRESENCE OF THIS BOUNDARY...AND PLENTY OF MOISTURE...IT MAY BE POSSIBLE TO SEE ISOLATED SHOWERS THROUGH THE NIGHT ACROSS THE SOUTHERN HALF OF KENTUCKY. THIS BOUNDARY WILL LINGER AROUND INTO WEDNESDAY AND WITH INSTABILITY AGAIN RAMPING UP DURING THE AFTERNOON...WE COULD BE LOOKING AT A FEW MORE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. HOWEVER...BY WEDNESDAY...VERY LITTLE SHEAR IS PRESENT...SO WE SHOULD SEE MORE ORDINARY THUNDERSTORMS WITH NO SEVERE THREAT. TEMPERATURES OVER THE NEXT 2 DAYS SHOULD BE FAIRLY SIMILAR TO WHAT WE HAVE SEEN LATELY WITH HIGHS INTO THE LOW TO MID 80S. SAME CAN BE SAID FOR LOWS TONIGHT WITH READINGS GENERALLY AROUND 70. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 301 PM EDT TUE SEP 2 2014 THE MODELS BEGIN THE EXTENDED PERIOD IN PRETTY GOOD AGREEMENT ONCE AGAIN...WITH A RIDGE OF HIGH PRESSURE...BOTH ALOFT AND AT THE SURFACE...CENTERED OVER THE EASTERN GULF OF MEXICO...ALONG WITH A WELL DEFINED TROUGH OF LOW PRESSURE ALOFT TAKING SHAPE OVER THE NORTHERN PLAINS. THE MODELS HAVE THE RIDGE STEADILY BREAKING DOWN TO BEGIN THE PERIOD...WITH SHOWERS AND STORMS POPPING UP BENEATH IT ACROSS THE TENNESSEE VALLEY DOWN TO THE GULF AND ACROSS PORTIONS OF THE SOUTHEASTERN CONUS. AS THE TROUGH EVOLVES AND STRENGTHENS...IT WILL EJECT OUT OF THE PLAINS WEDNESDAY AND THURSDAY...AND PUSH ACROSS THE GREAT LAKES AND OHIO VALLEY REGIONS. THE COLD FRONT TRAILING FROM THIS UPPER LOW WILL END UP BEING OUR WEATHER MAKER FOR THE UPCOMING WEEKEND. THE FRONT IS EXPECTED TO INTERACT WITH MOISTURE COMING OFF THE GULF OF MEXICO ON SOUTHWESTERLY WINDS. THE FRONT WILL HAVE A DIFFICULT TIME MOVING EASTWARD...HOWEVER...AS THE RIDGE DIGS IN A BIT JUST OFF THE SOUTHEAST COAST AND FLOW ALOFT BECOMES MORE ZONAL. THERE WILL BE A GOOD CHANCE OF RAIN FRIDAY MORNING THROUGH SUNDAY MORNING...AS LIFT AND MOISTURE ALONG THE SLUGGISH FRONT SET OFF REPEATED ROUNDS OF SHOWERS AND STORMS. THE RAIN SHOULD FINALLY MOVE OUT OF THE AREA SUNDAY EVENING...AS THE FRONT FINALLY MOVES OUT OF THE AREA. TEMPERATURES TO BEGIN THE PERIOD LOOK TO BE ABOVE NORMAL...WITH HIGHS TOPPING OUT AROUND IN THE MID TO UPPER 80S THURSDAY AND FRIDAY. ONCE THE FRONT STALLS ACROSS THE AREA AND PRECIPITATION BECOMES MORE WIDESPREAD...TEMPERATURES WILL LIKELY MAX OUT BELOW NORMAL VALUES SATURDAY THROUGH MONDAY. THE POSITIONING OF THE FRONT OVER THE WEEKEND WILL ALLOW FOR SOME COOLER AND DRIER AIR TO FILTER INTO THE AREA. HIGHS ON SATURDAY SHOULD BE JUST BELOW NORMAL...AS THE BULK OF COOL AIR SHOULD STILL BE TRAPPED NORTH OF THE OHIO RIVER. ON SUNDAY...HOWEVER...ONCE WINDS HAVE SHIFTED TO THE NORTH...TEMPERATURES WILL BE QUITE COOL...WITH READINGS PEAKING IN THE MID TO UPPER 70S FOR MOST LOCATIONS. THE NORTHERLY FLOW WILL ONLY ALLOW FOR A SMALL WARM UP ON MONDAY...AS HIGHS THAT DAY WILL LIKELY ONLY TOP OUT IN THE UPPER 70S AND LOWER 80S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 156 PM EDT TUE SEP 2 2014 EASTERN KENTUCKY IS PRIMED FOR THUNDERSTORMS AS MOIST AND UNSTABLE CONDITIONS ARE PREVALENT ACROSS THE AREA. THERE IS AN OLD OUTFLOW BOUNDARY BISECTING THE AREA WHICH WE ARE WATCHING AS A FOCAL POINT FOR CONVECTIVE INITIATION AND THERE IS ALSO A FRONT WHICH IS MOVING TOWARD THE AREA FROM THE NORTHWEST WITH LOTS OF PREFRONTAL CONVECTION OUT AHEAD OF IT. MAINLY VFR CONDITIONS ARE EXPECTED AT THE TAF SITES THIS AFTERNOON AND EVENING EXCEPT FOR IN THE VICINITY OF THE THUNDERSTORMS AND RAIN SHOWERS. PUT SOME TEMPO CONDITIONS IN THE TAF AS THE BEST ESTIMATE AS TO WHEN THUNDERSTORMS ARE MOST LIKELY AFFECT THEM. EXPECT SOME VLIFR TO FORM AT THE TAF STATIONS AS WELL AS THE VALLEYS LATER THIS EVENING AS THE CONVECTION MOVES OFF TO THE SOUTH AND EAST. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJ SHORT TERM...KAS LONG TERM...AR AVIATION...JJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
156 PM EDT TUE SEP 2 2014 .UPDATE... ISSUED AT 948 AM EDT TUE SEP 2 2014 THE FORECAST FOR THIS AFTERNOON HAS BECOME COMPLICATED BY THE REMNANTS OF AN MCS OVER THE OHIO VALLEY AND THE OUTFLOW BOUNDARY WHICH IS CURRENTLY MOVING INTO THE BLUEGRASS. CURRENT THINKING IS THAT THE OUTFLOW BOUNDARY WILL GENERALLY WEAKEN AS IT CONTINUES MOVING TO THE SOUTHEAST. THIS SHOULD BE TEMPORARY AND WILL THEN BE THE FOCUS OF DEVELOPMENT LATER IN THE AFTERNOON. SO PRETTY MUCH GOING WITH TWO PRONGS. THE FIRST BEING REDEVELOPMENT WITH THE OUTFLOW BOUNDARY AND THE SECOND BEING THE PREFRONTAL ACTIVITY. THE SEVERE THREAT TODAY WILL BE EFFECTED BY HOW MUCH DEBRIS CLOUD IS ABLE TO MOVE INTO THE AREA. THE LOW LEVEL INSTABILITY WILL BE EFFECTED BY EFFECTED BY THE CLOUDS. THE LATEST NAM BUFFER HAS REALLY BACKED OFF FROM YESTERDAY WITH HALF THE CAPE THAN WHAT WAS FORECAST YESTERDAY. ALSO MISSING IS THE DRY AIR POCKETS ALOFT WHICH WOULD HAVE BEEN HELPFUL FOR WET MICROBURSTS TO OCCUR. CAN NOT RULE OUT SEVERE THUNDERSTORMS...HOWEVER THE CHANCES HAVE GONE DOWN. MOST LIKELY WILL STILL SEE A COUPLE OF SEVERE STORMS WITH THIS SYSTEM. UPDATED THE FORECAST TO REFLECT THE CURRENT CONDITIONS AND MODEL TRENDS. UPDATE ISSUED AT 649 AM EDT TUE SEP 2 2014 NO SIGNIFICANT CHANGES MADE THIS MORNING. LINE OF SHOWERS AND STORMS EXTENDS FROM CINCINNATI SOUTHWEST TO THE NORTHWEST SIDE OF LOUISVILLE. THIS LINE CONTINUES TO SLOWLY WEAKEN AS IT MOVES EAST. IF IT WERE TO HOLD TOGETHER...LOOKS LIKE IT MAY WORK INTO THE BLUEGRASS COUNTIES AFTER 13Z. HOWEVER...GIVEN THE TREND THIS SEEMS UNLIKELY AND AT BEST PERHAPS AN ISOLATED SHOWER CAN HOLD TOGETHER. MAIN CONCERN CONTINUES TO BE LATER TODAY...PRIMARILY AFTER 2 PM AS OUTFLOW FROM THIS MORNINGS CONVECTION REDEVELOPS SHOWERS AND STORMS. NOT SURE THE COVERAGE WILL BE ALL THAT GREAT AFTER LOOKING AT THE LATEST HRRR AND NEW 06Z MAV GUIDANCE. BOTH OF THESE MODELS HAVE BACKED OFF SIGNIFICANTLY ON THE CHANCES OF RAIN TODAY. HOWEVER...GOING TO STAY THE COURSE AS THE TROUGH IS STILL FAIRLY DEFINED AND OUTFLOW HAS ALREADY DEFINED A BOUNDARY FOR NEW CONVECTION TO DEVELOP. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 330 AM EDT TUE SEP 2 2014 PRESENTLY...A SHORTWAVE TROUGH IS PUSHING INTO THE OHIO RIVER VALLEY REGION. AN MCS DEVELOPED YESTERDAY EVENING HEAD OF THIS TROUGH AND IS NOW MARCHING EASTWARD INTO CENTRAL/SOUTHERN INDIANA...STRETCHING BACK TO THE SOUTHWEST ACROSS SOUTHERN ILLINOIS. IR SATELLITE HAS SHOWN SOME WARMING WITH THE CLOUD TOPS OVER THE PAST HOUR OR TWO...INDICATING THAT THIS MCS MAY ALREADY BE ON THE DECLINE. IN FACT...THE HRRR SUPPORTS THE IDEA OF A DYING MCS AS IT TRIES TO PUSH INTO CENTRAL KENTUCKY TOWARDS DAYBREAK. CANNOT RULE OUT A FEW SHOWERS PUSHING INTO THE BLUEGRASS SHORTLY AFTER 8 AM...BUT ANTICIPATE MORE OF THE ACTION WITH THE SHORTWAVE TROUGH WILL COME LATER THIS AFTERNOON AS WE GENERATE SOME INSTABILITY. WITH THIS IN MIND...PLAN TO BACK OFF THE POPS THROUGH MIDDAY WITH JUST SOME ISOLATED SHOWERS FOR AREAS NORTH OF I-64. OUTFLOW FROM THE DYING MCS WILL BE PUSHING ACROSS EASTERN KENTUCKY EARLY THIS AFTERNOON...AND COULD KICK START THE CONVECTION AS IT ENCOUNTERS SOME DECENT INSTABILITY. THE FORCING ALOFT SHOULD ALLOW FOR FAIRLY GOOD SHOWER AND THUNDERSTORM COVERAGE BY MID TO LATE AFTERNOON. WITH BULK SHEAR VALUES OF 30-40KTS THIS AFTERNOON...A SEVERE THREAT WOULD EXIST AS THUNDERSTORMS COULD PUT OUT SOME DAMAGING WIND GUSTS. THE SHEAR PROFILES WEAKEN BY MID EVENING AND THE LOSS OF DAYTIME INSTABILITY SHOULD YIELD WEAKENING STORMS AFTER 6 PM. HOWEVER...A FEW GUSTY WINDS MAY STILL BE POSSIBLE THROUGH 8 OR 9 PM. THE SHORTWAVE TROUGH WILL STALL A COLD FRONT ACROSS SOUTHERN KENTUCKY BY LATE THIS EVENING. GIVEN THE PRESENCE OF THIS BOUNDARY...AND PLENTY OF MOISTURE...IT MAY BE POSSIBLE TO SEE ISOLATED SHOWERS THROUGH THE NIGHT ACROSS THE SOUTHERN HALF OF KENTUCKY. THIS BOUNDARY WILL LINGER AROUND INTO WEDNESDAY AND WITH INSTABILITY AGAIN RAMPING UP DURING THE AFTERNOON...WE COULD BE LOOKING AT A FEW MORE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. HOWEVER...BY WEDNESDAY...VERY LITTLE SHEAR IS PRESENT...SO WE SHOULD SEE MORE ORDINARY THUNDERSTORMS WITH NO SEVERE THREAT. TEMPERATURES OVER THE NEXT 2 DAYS SHOULD BE FAIRLY SIMILAR TO WHAT WE HAVE SEEN LATELY WITH HIGHS INTO THE LOW TO MID 80S. SAME CAN BE SAID FOR LOWS TONIGHT WITH READINGS GENERALLY AROUND 70. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 418 AM EDT TUE SEP 2 2014 THE FRONTAL BOUNDARY REFERENCED IN THE SHORT TERM WILL BE DISSOLVING EARLY IN THE LONG TERM PERIOD...BUT THERE SHOULD STILL BE DRY AIR IN PLACE WEDNESDAY NIGHT...ESPECIALLY ALOFT. IF ANY CONVECTIVE PRECIP CAN DEVELOP OFF OF LOW LEVEL MOISTURE ON WEDNESDAY AFTERNOON...IT SHOULD DIE OUT BY NIGHT AS HEATING IS LOST AND SUPPORT ALOFT WILL LIKELY BE LACKING. DEEPER MOISTURE WILL MAKE A COMEBACK LATE IN THE WEEK AND MAY FUEL A RESURGENCE OF SHOWERS AND THUNDERSTORMS...BUT A SUBTROPICAL RIDGE ALOFT OVER THE SE CONUS WILL HELP TO KEEP COVERAGE LIMITED FOR A WHILE. THE RIDGE WILL WEAKEN AND GET SUPPRESSED BY A BROAD TROUGH DROPPING SE INTO THE NE CONUS DURING THE WEEKEND. THIS WILL ALLOW A COLD FRONT TO MOVE INTO OUR REGION FROM THE NW. THE SCENARIO WILL ALLOW AN INCREASE IN PRECIP COVERAGE...WITH A PEAK EXPECTED ON SATURDAY. EVEN THOUGH THE FRONT SHOULD PASS BY SUNDAY...THE MODELS STILL LEAVE SOME QUESTION AS TO HOW EFFECTIVE THE FRONT WILL BE AT BRINGING IN A DRIER AIR MASS. HAVE HELD ONTO LOW POPS IN THE AFTERNOON AND EVENING ON SUNDAY AND MONDAY...ESPECIALLY IN OUR SE COUNTIES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 156 PM EDT TUE SEP 2 2014 EASTERN KENTUCKY IS PRIMED FOR THUNDERSTORMS AS MOIST AND UNSTABLE CONDITIONS ARE PREVALENT ACROSS THE AREA. THERE IS AN OLD OUTFLOW BOUNDARY BISECTING THE AREA WHICH WE ARE WATCHING AS A FOCAL POINT FOR CONVECTIVE INITIATION AND THERE IS ALSO A FRONT WHICH IS MOVING TOWARD THE AREA FROM THE NORTHWEST WITH LOTS OF PREFRONTAL CONVECTION OUT AHEAD OF IT. MAINLY VFR CONDITIONS ARE EXPECTED AT THE TAF SITES THIS AFTERNOON AND EVENING EXCEPT FOR IN THE VICINITY OF THE THUNDERSTORMS AND RAIN SHOWERS. PUT SOME TEMPO CONDITIONS IN THE TAF AS THE BEST ESTIMATE AS TO WHEN THUNDERSTORMS ARE MOST LIKELY AFFECT THEM. EXPECT SOME VLIFR TO FORM AT THE TAF STATIONS AS WELL AS THE VALLEYS LATER THIS EVENING AS THE CONVECTION MOVES OFF TO THE SOUTH AND EAST. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJ SHORT TERM...KAS LONG TERM...HAL AVIATION...JJ
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
359 PM EDT TUE SEP 2 2014 .SYNOPSIS... SHOWERS AND THUNDERSTORMS WILL PUSH ACROSS THE NORTH COUNTRY THROUGH THE EVENING HOURS AHEAD OF A COLD FRONT. EXPECT LOCALLY HEAVY DOWNPOURS AND GUSTY WINDS WITH THE STRONGER STORMS. SUNNY, DRY AND COOLER WEATHER WILL LAST INTO THURSDAY. WARM SUMMER WEATHER RETURNS FRIDAY BUT WILL BE SHORT LIVED AS ANOTHER COLD FRONT SWEEPS IN EARLY SATURDAY GIVING A TASTE OF FALL-LIKE WEATHER FOR SUNDAY AND EARLY NEXT WEEK. && .NEAR TERM /UNTIL 8 AM WEDNESDAY MORNING/... AS OF 355 PM EDT TUESDAY...WELL, THE ATMOSPHERE IS FAIRLY PRIMED. VERY WARM AND HUMID AIRMASS IS RESULTING IN MODEST SURFACE BASED INSTABILITY (CAPE PUSHING 2000 J/KG AND LIFTED INDEX OF -2 TO -4C). SO FAR THE ACTIVITY HAS BEEN SPARSE ACROSS THE FORECAST AREA, HOWEVER RADAR SHOWS THE BUILDING LINE OF SHOWERS AND THUNDERSTORMS OUT ACROSS ONTARIO. THESE STORMS SHOULD BE CROSSING INTO THE UNITED STATES IN THE NEXT COUPLE OF HOURS. STILL LIKE HOW THE HRRR AND OUR LOCAL 6KM WRF ARE HANDLING THE EVOLUTION OF THE CONVECTION. STILL LOOKS LIKE AN ETA INTO THE CHAMPLAIN VALLEY DURING THE EVENING (LET`S GO WITH 6-8PM) AND THEN INTO EASTERN VERMONT BY 10PM. UPPER LEVEL SHORTWAVE WHICH IS THE PRIMARY TRIGGER FOR THE CONVECTION IS NOW OVER MICHIGAN AND STARTING TO LIFT NORTHEAST. OUT AHEAD OF THAT SHORT WAVE THE WIND FIELDS AND RELATED SHEAR INCREASE, BUT AT THE SAME TIME WE ARE GETTING CLOSER TO SUNSET AND LOSS OF HEATING. SO IT`S A BATTLE BETWEEN TIMING OF THE BEST DYNAMICS VS BEST INSTABILITY. AT THIS POINT STILL SEE NOTHING TO CHANGE THE IDEA THAT WE`LL HAVE AT LEAST A FEW STRONG T-STORMS AROUND, ESPECIALLY THIS EVENING AND MAINLY WEST OF THE GREEN MOUNTAINS. HAVE MAINTAINED THE IDEA OF GUSTY WINDS AND HEAVY RAIN AS THE PRIMARY THREATS. THE ACTIVITY WINDS DOWN BY MID EVENING IN THE ST LAWRENCE VALLEY TO JUST AFTER MIDNIGHT IN EASTERN VERMONT. DEPENDING ON HOW MUCH CLEARING WE GET, WE COULD HAVE A BIT OF PATCHY FOG LATE TONIGHT. THE COOLER AIR LAGS THE WEATHER A BIT, SO IT WILL STILL BE A MUGGY NIGHT WITH LOWS IN THE 60S. && .SHORT TERM /8 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 355 PM EDT TUESDAY...IT WILL BE A QUIET 48 HOURS. SHORT TERM MODELS IN PRETTY GOOD AGREEMENT WITH REGARD TO RIDGING OVER THE REGION. DAILY SPECIFICS... WEDNESDAY: FLOW TURNS NORTHWEST DURING THE MORNING. 850MB TEMPERATURES FALL TO 11-12C WHICH WILL SUPPORT HIGH TEMPERATURES IN THE MID-UPPER 70S. WITH SOME WEAK COLD-AIR ADVECTION AND A GOOD DEAL OF SUN, WE`LL HAVE SOME EXCELLENT MIXING DURING THE AFTERNOON. WE SHOULD BE ABLE TO TAP SOME OF THE 20KT OR SO OF WIND THAT WILL BE A FEW THOUSAND FEET UP, SO IT SHOULD GET A LITTLE BREEZY IN THE AFTERNOON. WEDNESDAY NIGHT: HIGH PRESSURE OVERHEAD. CLEAR AND CALM, SO PATCHY FOG LOOKS LIKE A GOOD BET, ESPECIALLY SINCE THE GROUND WILL STILL BE A BIT DAMP FROM THE RAIN THIS EVENING. TEMPERATURES MAINLY IN THE 50S, THOUGH UPPER 40S POSSIBLE IN COLD SPOTS LIKE SARANAC LAKE. THURSDAY: SHORTWAVE RIDGING AND SURFACE HIGH PRESSURE STILL NEARLY OVERHEAD, BUT STARTING TO PUSH EAST OF THE AREA. 850MB TEMPERATURES UP TO 12-13C, WHICH SUPPORTS UPPER 70S TO LOW 80S FOR HIGHS. PLENTY OF SUN AS WELL. THURSDAY NIGHT: DISCARDED THE NAM AS IT SEEMS TOO AGRESSIVE WITH THE LEADING EDGE OF WARM AIR ADVECTION AND PRODUCES THICKENING CLOUDS AND EVEN SOME LIGHT SHOWERS. THINK IT WILL REMAIN MOSTLY CLEAR AND DRY PER OTHER MODELS. HOWEVER WITH SOUTHWEST FLOW DEVELOPING, IT WON`T BE AS COLD, LOTS OF 50S AND EVEN LOW 60S FOR LOWS. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 350 PM EDT TUESDAY...EXTENDED PERIOD REMAINS PREDOMINATELY QUIET...LARGELY DOMINATED BY HIGH PRESSURE STARTING THE LATTER PART OF THE WEEKEND...BUT WET TO BEGIN. FOR THE START OF THE PERIOD...RISING HEIGHTS AND WARMING TEMPERATURES CONTINUE FRIDAY AS AN UPPER RIDGE CRESTS OVER THE NORTHEAST IN ADVANCE OF OUR NEXT SURFACE FRONT. MEAN 925MB TEMPS OF +20-23C WILL SUPPORT HIGHS WELL ABOVE NORMAL FOR EARLY SEPTEMBER WITH WIDESPREAD 80`S EXPECTED. IT`LL BE MUGGY TOO WITH DEWPOINTS RANGING THROUGH THE 60S WHICH WILL CREATE AMPLE SURFACE INSTABILITY TO SUPPORT SHOWER AND THUNDERSTORM DEVELOPMENT ALONG/AHEAD OF THE AFOREMENTIONED FRONT WHICH WILL SHIFT INTO THE BTV CWA LATE IN THE DAY AND THROUGH THE EVENING. STILL LOOKS LIKE THE BEST UPPER DYNAMICS PASSES TO OUR NORTH...WITH THE SURFACE BOUNDARY PARALLEL WITH UPPER FLOW SUPPORTING THE IDEA OF A SLOW EASTWARD PROGRESSION WHICH IS MAINTAINED BY THE LATEST ECMWF. GFS REMAINS A BIT FASTER PUSHING THE BOUNDARY THROUGH THE CWA BY SATURDAY MORNING SO HAVE CONTINUED ON WITH THE PREVIOUS FORECAST THINKING LEANING TOWARDS THE ECMWF. BY LATE SATURDAY TREND WILL BE TOWARDS CLEARER AND DRIER WEATHER AS THE UPPER FLOW TURNS ZONAL AND SURFACE HIGH PRESSURE BUILDS EASTWARD OUT OF THE CENTRAL CONUS. THIS HIGH THEN SLOWLY SHIFTS EAST THROUGH THE NORTHEAST AND OFF INTO THE CANADIAN MARITIMES BY LATE TUESDAY OFFERING A NICE STRETCH OF LATE SUMMER WEATHER. TEMPS RETURN TO MORE SEASONABLE LEVELS TO MAYBE SLIGHTLY BELOW NORMAL WITH EXPECTED HIGHS SATURDAY THROUGH TUESDAY IN THE UPPER 60S TO LOW 70S...AND LOWS IN THE MID 40S TO LOW 50S. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... THROUGH 12Z WEDNESDAY...CURRENT VFR ACROSS THE AREA WILL DETERIORATE TO VARIABLE FLIGHT CONDITIONS AS SHOWERS AND THUNDERSTORMS DEVELOP ALONG/AHEAD OF A COLD FRONT AND MOVE ACROSS THE AREA THIS AFTERNOON THROUGH MIDNIGHT. CIGS WILL PRIMARILY REMAIN VFR BUT VSBY WILL BE REDUCED TO MVFR/IFR AS STORMS PASS. AFTER 06Z...PRECIP IS EAST OF THE REGION LEAVING GENERALLY CLOUDY SKIES. CIGS OVERNIGHT WILL GENERALLY BE VFR AT KMSS/KPBG/KBTV...BUT MVFR AT KRUT/KSLK/KMPV WITH POSSIBLE IFR AT KRUT UNDER BLOCKED FLOW. AFTER 12Z...ALL CIGS LIFT TO VFR WITH SCT-BKN DIURNAL STRATOCUMULUS EXPECTED THROUGH THE DAY. OUTLOOK 18Z WEDNESDAY THROUGH SUNDAY... 18Z WED - 00Z SAT...VFR UNDER HIGH PRESSURE. EARLY MORNING IFR FOG POSSIBLE...ESPECIALLY AT KMPV/KSLK. 00Z SAT - 00Z SUN...POSSIBLE MVFR AND BRIEF IFR IN SCATTERED SHOWERS AND THUNDERSTORMS. 00Z SUN - 00Z MON...VFR UNDER HIGH PRESSURE. EARLY MORNING IFR FOG POSSIBLE...ESPECIALLY AT KMPV/KSLK. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...NASH NEAR TERM...NASH SHORT TERM...NASH LONG TERM...LAHIFF AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
133 PM EDT TUE SEP 2 2014 .SYNOPSIS... EXPECT SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND TONIGHT ACROSS MUCH OF THE NORTH COUNTRY AS A COLD FRONT MOVES INTO THE REGION. SOME OF THE STORMS WILL HAVE THE POTENTIAL TO PRODUCE GUSTY WINDS, HEAVY DOWNPOURS AND POSSIBLY SMALL HAIL. THE COLD FRONT EXITS THE REGION TONIGHT AND SLIGHTLY COOLER AND DRIER WEATHER IS EXPECTED FOR WEDNESDAY AND THURSDAY AS HIGH PRESSURE BUILDS INTO THE REGION. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... AS OF 130 PM EDT TUESDAY...EARLY AFTERNOON REFRESH FEATURES SLIGHT UPWARD MODIFICATIONS IN TEMPERATURES (ALREADY 87F HERE AT BTV) AND A SLIGHT FINE TUNING OF THE POP/WEATHER EVOLUTION FOR THE NEXT 12 HOURS. OTHERWISE THE OVERALL SCENARIO FOR A LINE OF THUNDERSTORMS TO DEVELOP IN THE NEXT FEW HOURS AND ROLL FROM WEST TO EAST ACROSS THE FORECAST AREA IS STILL UNCHANGED. LAPS SHOWS DECENT AMOUNT OF SURFACE INSTABILITY WITH TEMPERATURES WELL INTO THE 80S AND DEWPOINTS PUSHING 70F IN MANY AREAS. CAPE VALUES UP AROUND 1500 J/KG. FROM THE LOOK OF THE CLOUDS AND RELATIVE LACK OF DEVELOPMENT CURRENTLY ON RADAR OVER NORTHERN NY AND MOST OF VERMONT, IT APPEARS THERE IS STILL A WEAK CAP AND DRY AIR ALOFT (THAT SHOWED ON 12Z SOUNDINGS). HOWEVER, LOOKING FARTHER TO THE WEST OVER ONTARIO SHOWS WHAT IS HEADING THIS WAY. 6KM LOCAL WRF MODEL AND 15Z HRRR ARE PRETTY CLOSE IN THE OVERALL EVOLUTION, AND BOTH SEEM REASONABLE. HAVE LEANED TOWARD THEIR OUTPUT FOR POPULATING THE GRIDS. IF ANYTHING, THEY (AS TYPICAL) MIGHT BE AN HOUR OR TWO TOO SLOW IN TIMING. WE SHOULD SEE THE STORMS TO THE WEST CONTINUE TO EVOLVE INTO A SEMI-CONTINUOUS LINE. THESE STORMS SHOULD REACH THE ST LAWRENCE VALLEY ABOUT 20Z, THE CHAMPLAIN VALLEY ABOUT 22-23Z AND THEN INTO EASTERN VERMONT BY 01Z. THINK PRIMARY THREAT REMAINS GUSTY WINDS (THANKS TO MODERATE WINDS ALOFT AND THE DRY AIR AT MID LEVELS WHICH COULD ENHANCE DOWNBURST POTENTIAL) ALONG WITH HEAVY RAIN (GUIDANCE SUGGEST PRECIPITABLE WATER VALUES APPROACH 2". SHOULD NOT BE AN OVER THE TOP SEVERE WEATHER DAY, BUT IT WILL BE A BIT BUSY LATER THIS AFTERNOON INTO THE EARLY EVENING. && .SHORT TERM /8 PM THIS EVENING THROUGH THURSDAY/... AS OF 421 AM EDT TUESDAY...SHOWERS AND STORMS SHOULD END FROM WEST TO EAST ACROSS THE AREA TONIGHT WITH ACTIVITY EXITING MOST OF THE AREA AFTER MIDNIGHT. WESTERLY FLOW ALOFT THEN DEVELOPS FOR WEDNESDAY AND THURSDAY AND HIGH PRESSURE BUILDS IN FROM THE WEST. THIS WILL KEEP THE FORECAST DRY DURING THIS PERIOD AND WITH HIGH PRESSURE BUILDING IN FROM THE WEST AND NOT THE NORTHWEST...COLDER AIR WILL NOT MAKE IT INTO THE REGION. SO EVEN THOUGH CONDITIONS WILL BE COOLER THAN THE PAST COUPLE OF DAYS...HIGH TEMPERATURES WILL BE AT OR SLIGHTLY ABOVE SEASONAL NORMALS WITH READINGS IN THE 70S TO AROUND 80. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 410 AM EDT TUESDAY...FORECAST AREA PREDOMINANTLY UNDER WESTERLY UPPER LEVEL FLOW WITH EASTERN US RIDGE NOSING INTO NEW ENGLAND EARLY IN THE EXTENDED PERIOD...FOLLOWED BY LOWERING HEIGHTS AND BROAD TROUGH ESTABLISHED FROM THE WEEKEND ONWARD. GENERALLY QUIET WEATHER DURING THE EXTENDED PERIOD EXPECT FOR FRONTAL PASSAGE FOR THE WEEKEND BRINGING CHANCES FOR RAIN. RISING HEIGHTS AND WARMING TEMPERATURES THURSDAY INTO FRIDAY AS RIDGE BUILDS INTO THE NORTHEAST IN ADVANCE OF NEXT SURFACE FRONT. BY FRIDAY...850 MB TEMPS HIT THE UPPER TEENS...WHICH WOULD SUPPORT VERY WARM HIGHS IN THE MID TO UPPER 80S...A GOOD 10 DEGREES ABOVE NORMAL. GIVEN 850 MB TEMPS...ADJUSTED MAX TEMPS ON FRIDAY UP A DEGREE OR TWO ABOVE GUIDANCE. 500 MB TROUGH AND ASSOCIATED SURFACE FRONT MOVES ACROSS THE NORTHERN US TIER STATES THROUGH MID WEEK...THEN LIFTS NORTH ACROSS CENTRAL QUEBEC LATE IN THE WEEK INTO THE WEEKEND. TRAILING COLD FRONT ENTERS THE SAINT LAWRENCE VALLEY LATE FRIDAY AND MOVES THROUGH THE FORECAST AREA OVER THE WEEKEND. WITH BEST UPPER DYNAMICS AND SURFACE LOW PASSING TO NORTH...SURFACE BOUNDARY SLOWS AND BECOMES ORIENTED MORE NORTHEAST TO SOUTHWEST...PARALLEL WITH UPPER FLOW. MODEL DIFFERENCES BECOME APPARENT LATE SATURDAY INTO SUNDAY...WITH GFS MOVING THE SURFACE BOUNDARY AND PRECIPITATION TO THE NEW ENGLAND COAST...WHILE ECMWF HANGS IT UP IN INTERIOR NEW ENGLAND. HEDGED TOWARD THE ECMWF SOLUTION AND KEPT CHANCE POPS INTO SUNDAY. RIGHT NOW SATURDAY HAS THE BEST CHANCES FOR RAIN AND THUNDER... COINCIDING FRONTAL PASSAGE WITH MAX DAYTIME HEATING. TEMPERATURES DO RETURN TO SEASONAL NORMALS FOR THE WEEKEND WITH FRONTAL PASSAGE AND LOWER HEIGHTS AS THE EASTERN RIDGE IS SUPPRESSED. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... THROUGH 12Z WEDNESDAY...CURRENT VFR ACROSS THE AREA WILL DETERIORATE TO VARIABLE FLIGHT CONDITIONS AS SHOWERS AND THUNDERSTORMS DEVELOP ALONG/AHEAD OF A COLD FRONT AND MOVE ACROSS THE AREA THIS AFTERNOON THROUGH MIDNIGHT. CIGS WILL PRIMARILY REMAIN VFR BUT VSBY WILL BE REDUCED TO MVFR/IFR AS STORMS PASS. AFTER 06Z...PRECIP IS EAST OF THE REGION LEAVING GENERALLY CLOUDY SKIES. CIGS OVERNIGHT WILL GENERALLY BE VFR AT KMSS/KPBG/KBTV...BUT MVFR AT KRUT/KSLK/KMPV WITH POSSIBLE IFR AT KRUT UNDER BLOCKED FLOW. AFTER 12Z...ALL CIGS LIFT TO VFR WITH SCT-BKN DIURNAL STRATOCUMULUS EXPECTED THROUGH THE DAY. OUTLOOK 18Z WEDNESDAY THROUGH SUNDAY... 18Z WED - 00Z SAT...VFR UNDER HIGH PRESSURE. EARLY MORNING IFR FOG POSSIBLE...ESPECIALLY AT KMPV/KSLK. 00Z SAT - 00Z SUN...POSSIBLE MVFR AND BRIEF IFR IN SCATTERED SHOWERS AND THUNDERSTORMS. 00Z SUN - 00Z MON...VFR UNDER HIGH PRESSURE. EARLY MORNING IFR FOG POSSIBLE...ESPECIALLY AT KMPV/KSLK. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...EVENSON NEAR TERM...NASH SHORT TERM...EVENSON LONG TERM...HANSON AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1247 PM EDT TUE SEP 2 2014 .SYNOPSIS... A WEAK COLD FRONT WILL MOVE ACROSS THE AREA TODAY EXTENDING FROM LOW PRESSURE TRACKING NORTHEAST ACROSS QUEBEC. HIGH PRESSURE WILL EXPAND OVER THE OHIO VALLEY TONIGHT...THEN TO THE EAST COAST ON WEDNESDAY. A WARM FRONT WILL LIFT NORTH ON THURSDAY AHEAD OF THE NEXT LOW PRESSURE SYSTEM THAT WILL PASS NORTH OF THE GREAT LAKES ON FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LINE OF SHOWERS AND A FEW EMBEDDED THUNDERSTORMS PUSHING INTO NORTHWEST OHIO AT THIS TIME WITH THE COLD FRONT. STILL EXPECTING SOME SUN BEHIND THE FRONT ONCE IT MOVES THROUGH THE REGION. DECIDED TO BUMP TEMPERATURES DOWN A FEW DEGREES DUE TO EXTENSIVE CLOUD COVER AND COOL AIR ADVECTION BEHIND THE FRONT. OTHERWISE...NO SIGNIFICANT CHANGES. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... HIGH PRESSURE WILL EXPAND EASTWARD ACROSS THE OHIO VALLEY TONIGHT. IT LOOKS LIKE A WEAK THERMAL TROUGH WILL LINGER OVER LAKE ERIE ON THE NORTH SIDE OF THE HIGH THIS EVENING AND MAY PROVIDE ENOUGH CONVERGENCE FOR A FEW SHOWERS TO DEVELOP OVER THE LAKE. LEFT A LOW POP BOTH OVER THE LAKE AND ALONG THE EASTERN LAKESHORE FOR A PORTION OF THE NIGHT. INLAND AREAS...ESPECIALLY OUR SOUTHERN COUNTIES COULD SEE SOME FOG OR STRATUS GIVEN THE LINGERING BOUNDARY LAYER MOISTURE COUPLED WITH CLEARING SKIES AND LIGHT WINDS. TEMPERATURES WILL BOTTOM OUT IN THE UPPER 50S TO LOW 60S. THE AIR MASS DOES NOT COOL MUCH WITH THE FRONTAL PASSAGE AND TEMPERATURES ARE STILL EXPECTED TO BE A COUPLE DEGREES ABOVE NORMAL ON WEDNESDAY. THE MAIN DIFFERENCE WILL BE FELT IN THE HUMIDITY WHICH WILL BE LOWER AND MORE PLEASANT WITH DEW POINTS NEAR 60 DEGREES. MAINLY JUST SCATTERED CU ON WEDNESDAY ONCE ANY MORNING CLOUDS BURN OFF. HEIGHTS WILL REBOUND OVER THE AREA ON THURSDAY AND A WARM FRONT WILL LIFT NORTH AHEAD OF THE NEXT LOW PRESSURE SYSTEM TRACKING OUT OF THE PLAINS. THIS SYSTEM IS FORECAST TO TRACK ACROSS LAKE SUPERIOR THEN CONTINUE NORTHEAST ACROSS ONTARIO AND QUEBEC. ENOUGH DRY AIR SHOULD STILL BE IN PLACE ON THURSDAY FOR THE FORECAST AREA TO STAY DRY. LEFT THE 20 POP IN THE FORECAST ON THURSDAY NIGHT AS MOISTURE DOES START TO INCREASE ALTHOUGH THE MORE FOCUSED MOISTURE ADVECTION WILL BE WELL TO THE NORTH. THE ASSOCIATED COLD FRONT WILL SINK SOUTH TOWARDS THE AREA ON FRIDAY. LOWERED POPS DURING THE MORNING HOURS AND ACROSS THE SOUTHERN COUNTIES THAT SHOULD STRUGGLE TO SEE ANY PRECIPITATION UNTIL FRIDAY NIGHT. TEMPERATURES ON THURSDAY AND FRIDAY WILL BE IN THE MID 80S...WITH A FEW SPOTS MAKING A RUN AT THE UPPER 80S. && .LONG TERM /SATURDAY THROUGH MONDAY/... NO BIG CHANGES TO THE MODELS FOR THE EXTENDED WITH GUIDANCE SHOWING A COLD FRONT TO OUR SOUTH SATURDAY MORNING WITH DRIER AIR AND HIGH MOVING IN FROM THE NORTH. DONT THINK THE DAY WILL BEGIN DRY HOWEVER AS THE ECMWF REMAINS SLOWER THAN THE GFS IN MOVING MOISTURE OUT OF THE AREA. WILL CONTINUE WITH CHANCE POPS THROUGH THE MORNING SATURDAY BEFORE DROPPING TO A SLIGHT CHANCE ACROSS THE NORTH. SATURDAY NIGHT THROUGH MONDAY LOOK DRY. TEMPS NEAR NORMAL AFTER AN ABOVE NORMAL END TO THE WEEK. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... WEAK COLD FRONT TO OUR NORTHWEST NR A KFNT-KSBN LINE. FROM WILL MOVE THROUGH THE AREA DURING THE DAY. CONVECTION FROM INDIANA TRACKING ENE ACROSS CENTRAL AND SRN OHIO. WILL LIKELY SEE THUNDER INTO NRN OHIO BUT KEPT MENTION OUT OF THE FAR NRN TAFS. HRRR MOVES THIS PRECIP THROUGH DURING THE MORNING AND EARLY AFTERNOON WITH POSSIBLY A FEW LINGERING SHOWERS FOR MID AFTERNOON. EXPECT MAINLY MVFR CONDITIONS WITH AND JUST BEHIND THE PRECIP...LIFTING TO VFR 2 TO 4 HOURS AFTER PRECIP ENDS. EXPECT THE EVENING WILL BEGIN VFR HOWEVER WITH LOW LEVEL MOISTURE IN PLACE...DRYING ALOFT AND HIGH PRESSURE OVER THE AREA EXPECT MVFR AND POSSIBLY IFR CIGS/FOG TO DEVELOP OVERNIGHT. OUTLOOK...NON VFR LIKELY IN SHOWERS AND THUNDERSTORMS BY FRIDAY EVENING INTO SATURDAY WITH THE NEXT COLD FRONT. && .MARINE... WILL BEGIN TODAY CLOSE TO SMALL CRAFT CRITERIA MAINLY EAST OF CONNEAUT BUT FOR NOW WILL CONTINUE WITH A FORECAST JUST BELOW. WINDS TODAY WILL BE FROM THE SOUTHWEST AHEAD OF A WEAK COLD FRONT DUE IN LATE MORNING/EARLY AFTERNOON. WINDS WILL TURN WEST TO BRIEFLY NORTHWEST BEHIND THE BOUNDARY. HIGH PRESSURE BUILDS IN TONIGHT AND WEDNESDAY. THURSDAY THE HIGH WILL DRIFT EAST AND A LOW WILL BE MOVING THROUGH THE NORTHERN PLAINS. THIS WILL AGAIN SETUP SOUTHWEST FLOW ON THE LAKE THURSDAY INCREASING TO 10 TO 20 KNOTS. THE LOW WILL MOVE THROUGH EASTERN CANADA FRIDAY DRAGGING A COLD FRONT ACROSS THE LAKE DURING THE AFTERNOON. WINDS WILL TURN NORTHWEST FRIDAY NIGHT AND SATURDAY BEHIND THE FRONT. ALTHOUGH CLOSE...NO NEAR TERM HEADLINES FOR NOW. FRIDAY INTO SATURDAY WE COULD REACH SMALL CRAFT CRITERIA AS WINDS TURN NORTHWEST. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KEC NEAR TERM...LOMBARDY SHORT TERM...KEC LONG TERM...TK AVIATION...TK MARINE...TK
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
531 PM CDT TUE SEP 2 2014 .UPDATE... THUNDERSTORMS HAVE DEVELOPED OVER THE WESTERN AND CENTRAL SOUTH PLAINS...A BIT SOUTH OF PREVIOUS BEST-GUESS...BUT GIVE SHORT TERM SOLUTIONS SOME CREDIT. WE HAVE UPDATED FOR LOW COVERAGE THUNDER THROUGH EARLY THIS EVENING. 1500-2000 JOULES PER KILOGRAM OF CONVECTIVE ENERGY BUT VERY LITTLE SHEAR CONTRIBUTING TO BRIEF HEAVY SHOWERS AND BRIEF MOSTLY WEAK HAIL INDICATIONS AT THIS TIME. ACTIVITY SHOULD TAKE ON BETTER NORTHERLY DRIFT...THOUGH BELIEVE MOST ACTIVITY WILL RELENT BY DARK. RMCQUEEN && .PREV DISCUSSION... /ISSUED 306 PM CDT TUE SEP 2 2014/ SHORT TERM... FOCUS IN THE SHORT TERM IS ON SMALL CHANCE FOR ISOLATED SHOWERS AND/OR THUNDERSTORMS LATE THIS AFTN AND THIS EVENING. RADAR IS QUIET ATTM BUT SATELLITE SHOWING AN AREA OF CUMULUS DEVELOPMENT TO THE EAST AND SOUTHEAST OF LUBBOCK IN AN AREA WHERE OBJECTIVE ANALYSIS SHOWS ENHANCED INSTABILITY AND WEAKENING INHIBITION. SOME VERY MODEST LOW LEVEL SPEED CONVERGENCE AND MOISTURE ADVECTION IN THIS AREA MAY NOT HELP TOO MUCH BUT CERTAINLY WILL NOT HURT. A WEAK FRONTAL BOUNDARY PULLED UP STATIONARY NEAR A MORTON TO TULIA LINE WITH WEAK CONFLUENCE IN ITS VICINITY BUT WITH SFC DEW POINTS ABOUT 5 DEGREES LOWER THAN IN THE FORMER AREA. WOULD EXPECT THESE TWO AREAS HAVE THE BEST CHANCE OF SEEING CONVECTIVE DEVELOPMENT. 12Z WRF-NAM HIGHLIGHTS THE LATTER WHILE RECENT RUNS OF THE HRRR FEATURES THE FORMER. EITHER WAY WILL LIKELY BE DIFFICULT TO GENERATE ANYTHING OTHER THAN SMALL-SCALE AND ISOLATED SHOWERS WITH AREAL COVERAGE NOT WARRANTING MENTION IN THE ZONE FCST ATTM. WEDNESDAY SHOULD BE EVEN MORE DIFFICULT TO PRODUCE PRECIP WITH STRENGTHENING HIGH PRESSURE OVERHEAD AND LOW LEVEL FLOW BECOMING MORE UNIFORM FROM THE SOUTH. TEMPS TO REMAIN WARMER THAN NORMAL WITH BOTH LOWS AND HIGHS NEAR WARMER MAV GUIDANCE LOOKING MORE LIKELY ATTM. LONG TERM... ONLY MINOR CHANGES TO THE LONG TERM FORECAST FOR THIS ITERATION...AS A MUTED COOLING TREND WILL BE FOLLOWED BY A POTENTIALLY WET WEEKEND FOR PARTS OF THE REGION. BY WEDNESDAY EVENING...A MOSTLY ZONAL UPPER FLOW REGIME WILL BE IN PLACE ACROSS THE CONUS...WITH AN ELONGATED UPPER RIDGE IN PLACE ACROSS MOST OF THE SOUTH...INCLUDING WEST TEXAS. WHILE THIS WILL CONTINUE TO ENSURE MOSTLY DRY CONDITIONS THROUGH THE END OF THE WORK WEEK...GRADUALLY DROPPING 1000-500 MB THICKNESSES WILL ALLOW TEMPERATURES TO INCREMENTALLY FALL BACK TO A MORE REASONABLE UPPER 80S ON THE SOUTH PLAINS TO MID 90S ON THE ROLLING PLAINS. BY LATE IN THE WEEK AND THROUGH THE WEEKEND...A BROAD UPPER TROUGH WILL PUSH EASTWARD ACROSS THE NORTHERN CONUS...SENDING A MODEST COLD FRONT SOUTHWARD THROUGH THE CENTRAL PLAINS AND AT LEAST THE TEXAS PANHANDLE. MEANWHILE DEEPER MONSOONAL MOISTURE...POSSIBLY WITH A CONNECTION TO REMNANTS OF TROPICAL STORM DOLLY...WILL BE DRAWN NORTHWARD INTO THE SOUTHWEST AND EVENTUALLY EASTWARD AS IT GETS CAUGHT IN THE WESTERLY UPPER FLOW ASSOCIATED WITH THE PREVIOUSLY MENTIONED TROUGH. ALL OF THIS IS EXPECTED TO RESULT IN INCREASING RAIN CHANCES BEGINNING AS EARLY AS LATE FRIDAY...AND POSSIBLY LASTING THROUGH LATE SUNDAY DEPENDING ON A FEW FACTORS. THE MOST PROMINENT OF THESE FACTORS SEEMS TO BE THE TIMING AND STRENGTH OF THE APPROACHING COLD FRONT...AS THE GFS AND ECMWF REMAIN ABOUT 24 HOURS APART IN THIS REGARD. THE GFS INDICATES A SLOWER...WEAKER FRONT REACHING THE NORTHERN BORDER OF THE CWA LATE SATURDAY AFTERNOON AND WASHING OUT ACROSS THE CWA SUNDAY. MEANWHILE...THE ECMWF SOLUTION BRINGS THIS FRONT INTO THE AREA AS EARLY AS LATE FRIDAY...AND PUSHES THE BOUNDARY WELL THROUGH THE CWA BY LATE SATURDAY. THE LATTER SOLUTION NOT SURPRISINGLY DEVELOPS THE HEAVIEST PRECIPITATION DURING THE LATE FRIDAY THROUGH SATURDAY TIME FRAME...WHILE THE GFS SEEMS TO BE FOCUSING ON THE LATE SATURDAY THROUGH LATE SUNDAY TIME FRAME. GIVEN THAT THE BOUNDARY WILL BE WELL REMOVED FROM ITS PARENT TROUGH BY THE TIME IT REACHES THIS LATITUDE...WE WILL CONTINUE TO SIDE WITH THE SLOWER GFS SOLUTION AND HIGHLIGHT LATE SATURDAY WITH THE HIGHEST POPS. LIKEWISE...LOW END POPS WERE ALSO EXTENDED THROUGH SUNDAY EVENING GIVEN THAT IN THIS SLOWER SCENARIO REMNANTS OF THIS BOUNDARY AND AMPLE MOISTURE WOULD LIKELY LINGER THROUGH THIS PERIOD. HOWEVER...UNCERTAINTIES REGARDING FRONTAL TIMING AND STRENGTH ARE COMPOUNDED FURTHER ON SUNDAY WITH THE POSSIBILITY OF LINGERING NOCTURNAL CONVECTION AND STABILIZING OUTFLOWS. BY MONDAY...THE UPPER RIDGE IS EXPECTED TO SLIGHTLY AMPLIFY ACROSS THE SOUTHERN PLAINS WHILE THE COLUMN DRIES CONSIDERABLY. THIS SHOULD TAPER OFF PRECIPITATION CHANCES UNTIL LATER IN THE WEEK WHEN ANOTHER POSSIBLY STRONGER COLD FRONT MOVES THROUGH THE REGION. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 61 92 62 90 62 / 10 0 10 10 10 TULIA 68 93 66 91 66 / 20 0 10 0 10 PLAINVIEW 68 93 66 90 66 / 20 0 0 0 10 LEVELLAND 66 92 66 90 67 / 20 0 10 10 0 LUBBOCK 72 93 68 92 67 / 20 0 0 10 0 DENVER CITY 66 91 66 89 66 / 20 0 10 10 10 BROWNFIELD 68 93 67 90 67 / 20 0 0 10 0 CHILDRESS 75 97 75 96 72 / 10 0 0 0 0 SPUR 73 97 72 94 71 / 10 0 0 10 10 ASPERMONT 76 99 74 96 73 / 0 0 0 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 05/99
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
306 PM CDT TUE SEP 2 2014 .SHORT TERM... FOCUS IN THE SHORT TERM IS ON SMALL CHANCE FOR ISOLATED SHOWERS AND/OR THUNDERSTORMS LATE THIS AFTN AND THIS EVENING. RADAR IS QUIET ATTM BUT SATELLITE SHOWING AN AREA OF CUMULUS DEVELOPMENT TO THE EAST AND SOUTHEAST OF LUBBOCK IN AN AREA WHERE OBJECTIVE ANALYSIS SHOWS ENHANCED INSTABILITY AND WEAKENING INHIBITION. SOME VERY MODEST LOW LEVEL SPEED CONVERGENCE AND MOISTURE ADVECTION IN THIS AREA MAY NOT HELP TOO MUCH BUT CERTAINLY WILL NOT HURT. A WEAK FRONTAL BOUNDARY PULLED UP STATIONARY NEAR A MORTON TO TULIA LINE WITH WEAK CONFLUENCE IN ITS VICINITY BUT WITH SFC DEW POINTS ABOUT 5 DEGREES LOWER THAN IN THE FORMER AREA. WOULD EXPECT THESE TWO AREAS HAVE THE BEST CHANCE OF SEEING CONVECTIVE DEVELOPMENT. 12Z WRF-NAM HIGHLIGHTS THE LATTER WHILE RECENT RUNS OF THE HRRR FEATURES THE FORMER. EITHER WAY WILL LIKELY BE DIFFICULT TO GENERATE ANYTHING OTHER THAN SMALL-SCALE AND ISOLATED SHOWERS WITH AREAL COVERAGE NOT WARRANTING MENTION IN THE ZONE FCST ATTM. WEDNESDAY SHOULD BE EVEN MORE DIFFICULT TO PRODUCE PRECIP WITH STRENGTHENING HIGH PRESSURE OVERHEAD AND LOW LEVEL FLOW BECOMING MORE UNIFORM FROM THE SOUTH. TEMPS TO REMAIN WARMER THAN NORMAL WITH BOTH LOWS AND HIGHS NEAR WARMER MAV GUIDANCE LOOKING MORE LIKELY ATTM. && .LONG TERM... ONLY MINOR CHANGES TO THE LONG TERM FORECAST FOR THIS ITERATION...AS A MUTED COOLING TREND WILL BE FOLLOWED BY A POTENTIALLY WET WEEKEND FOR PARTS OF THE REGION. BY WEDNESDAY EVENING...A MOSTLY ZONAL UPPER FLOW REGIME WILL BE IN PLACE ACROSS THE CONUS...WITH AN ELONGATED UPPER RIDGE IN PLACE ACROSS MOST OF THE SOUTH...INCLUDING WEST TEXAS. WHILE THIS WILL CONTINUE TO ENSURE MOSTLY DRY CONDITIONS THROUGH THE END OF THE WORK WEEK...GRADUALLY DROPPING 1000-500 MB THICKNESSES WILL ALLOW TEMPERATURES TO INCREMENTALLY FALL BACK TO A MORE REASONABLE UPPER 80S ON THE SOUTH PLAINS TO MID 90S ON THE ROLLING PLAINS. BY LATE IN THE WEEK AND THROUGH THE WEEKEND...A BROAD UPPER TROUGH WILL PUSH EASTWARD ACROSS THE NORTHERN CONUS...SENDING A MODEST COLD FRONT SOUTHWARD THROUGH THE CENTRAL PLAINS AND AT LEAST THE TEXAS PANHANDLE. MEANWHILE DEEPER MONSOONAL MOISTURE...POSSIBLY WITH A CONNECTION TO REMNANTS OF TROPICAL STORM DOLLY...WILL BE DRAWN NORTHWARD INTO THE SOUTHWEST AND EVENTUALLY EASTWARD AS IT GETS CAUGHT IN THE WESTERLY UPPER FLOW ASSOCIATED WITH THE PREVIOUSLY MENTIONED TROUGH. ALL OF THIS IS EXPECTED TO RESULT IN INCREASING RAIN CHANCES BEGINNING AS EARLY AS LATE FRIDAY...AND POSSIBLY LASTING THROUGH LATE SUNDAY DEPENDING ON A FEW FACTORS. THE MOST PROMINENT OF THESE FACTORS SEEMS TO BE THE TIMING AND STRENGTH OF THE APPROACHING COLD FRONT...AS THE GFS AND ECMWF REMAIN ABOUT 24 HOURS APART IN THIS REGARD. THE GFS INDICATES A SLOWER...WEAKER FRONT REACHING THE NORTHERN BORDER OF THE CWA LATE SATURDAY AFTERNOON AND WASHING OUT ACROSS THE CWA SUNDAY. MEANWHILE...THE ECMWF SOLUTION BRINGS THIS FRONT INTO THE AREA AS EARLY AS LATE FRIDAY...AND PUSHES THE BOUNDARY WELL THROUGH THE CWA BY LATE SATURDAY. THE LATTER SOLUTION NOT SURPRISINGLY DEVELOPS THE HEAVIEST PRECIPITATION DURING THE LATE FRIDAY THROUGH SATURDAY TIME FRAME...WHILE THE GFS SEEMS TO BE FOCUSING ON THE LATE SATURDAY THROUGH LATE SUNDAY TIME FRAME. GIVEN THAT THE BOUNDARY WILL BE WELL REMOVED FROM ITS PARENT TROUGH BY THE TIME IT REACHES THIS LATITUDE...WE WILL CONTINUE TO SIDE WITH THE SLOWER GFS SOLUTION AND HIGHLIGHT LATE SATURDAY WITH THE HIGHEST POPS. LIKEWISE...LOW END POPS WERE ALSO EXTENDED THROUGH SUNDAY EVENING GIVEN THAT IN THIS SLOWER SCENARIO REMNANTS OF THIS BOUNDARY AND AMPLE MOISTURE WOULD LIKELY LINGER THROUGH THIS PERIOD. HOWEVER...UNCERTAINTIES REGARDING FRONTAL TIMING AND STRENGTH ARE COMPOUNDED FURTHER ON SUNDAY WITH THE POSSIBILITY OF LINGERING NOCTURNAL CONVECTION AND STABILIZING OUTFLOWS. BY MONDAY...THE UPPER RIDGE IS EXPECTED TO SLIGHTLY AMPLIFY ACROSS THE SOUTHERN PLAINS WHILE THE COLUMN DRIES CONSIDERABLY. THIS SHOULD TAPER OFF PRECIPITATION CHANCES UNTIL LATER IN THE WEEK WHEN ANOTHER POSSIBLY STRONGER COLD FRONT MOVES THROUGH THE REGION. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 61 92 62 90 62 / 10 0 10 10 10 TULIA 68 93 66 91 66 / 10 0 10 0 10 PLAINVIEW 68 93 66 90 66 / 10 0 0 0 10 LEVELLAND 66 92 66 90 67 / 0 0 10 10 0 LUBBOCK 71 93 68 92 67 / 10 0 0 0 0 DENVER CITY 66 91 66 89 66 / 0 0 10 10 10 BROWNFIELD 68 93 67 90 67 / 0 0 0 10 0 CHILDRESS 75 97 75 96 72 / 10 0 0 0 0 SPUR 73 97 72 94 71 / 10 0 0 10 10 ASPERMONT 76 99 74 96 73 / 0 0 0 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07/16
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1257 PM CDT TUE SEP 2 2014 .DISCUSSION... 18Z AVIATION DISCUSSION BELOW. && .AVIATION... LITTLE REGIONAL AIR MASS CHANGE OVER THE NEXT 24-30 HOURS. THE RESIDENT UNSTABLE AIR MASS WILL REMAIN UNSEASONABLY MOIST THROUGH THURSDAY. ALTHOUGH MOST CONVECTIVE ACTIVITY WILL REMAIN NORTH OF THE METRO HUBS TODAY...INCREASING CHANCES FOR MORE WIDESPREAD GULF PRECIPITATION MOVING INLAND DURING THE EARLY AM WED HOURS WILL PLACE MORE COASTAL TERMINALS UNDER MODERATE CHANCES FOR SPEED CONVERGENCE SHRA OR TSRA THROUGH SUNRISE. THUS...THE THINKING IS THAT MANY TERMINALS WILL EXPERIENCE BRIEF PERIODS OF PASSING SHOWERS...WITH THAT EVEN SHORTER-LIVED THUNDERSTORM...PASSING WITHIN THE VICINITY FROM LATE MORNING THROUGH MID-AFTERNOON. 31 && .PREV DISCUSSION... /ISSUED 1026 AM CDT TUE SEP 2 2014/ UPDATE... SEE MORNING UPDATE. DISCUSSION... 12Z SOUNDINGS SHOW PW VALUES BETWEEN 2.1 AND 2.2 INCHES AND THIS IS SUPPORTED BY GPS MET DATA, CONVECTIVE TEMPS ARE BETWEEN 86 AND 88 DEGREES TODAY AND THIS THRESHOLD WILL BE MET EASILY. A WELL DEVELOPED S/WV EXTENDS FROM CENTRAL ARKANSAS INTO CENTRAL TEXAS WHICH SERVE AS ANOTHER FOCUS FOR SHRA/TSRA. UPPER LEVEL RIDING HAS INCHED CLOSER TO SE TX WHICH WILL IMPART A BIT OF SUBSIDENCE. THE RAP IS VERY AGGRESSIVE WITH RAINFALL THIS AFTN WHILE THE HRRR/ARW-EAST REMAIN MORE BENIGN. THE RAP WAS OVERDONE YESTERDAY AND DID NOT INITIALIZE ALL THAT WELL SO HAVE LEANED TOWARD A HRRR/WRF BLEND. CHANCE POPS LOOK APPROPRIATE SO NO CHANGES TO THE POP/WX GRIDS. DID BUMP MAX T GRIDS UP A FEW DEGREES TO MATCH TRENDS/OBS. AS FOR TS DOLLY...THE STORM WILL PROBABLY MAKE LANDFALL A BIT EARLIER...SOMETIME THIS EVENING. THE MAIN EFFECT FOR SE TX WILL BE INCREASING SWELLS OVER THE OFFSHORE MARINE ZONES AND A 1.0-1.5 FOOT BUMP UP IN TIDE LEVELS. NEW ZONES OUT BY 1030 AM. 43 && PREV DISCUSSION... /ISSUED 405 AM CDT TUE SEP 2 2014/ DISCUSSION... A FEW SHOWERS ARE MOVING NORTHWARD ACROSS THE COASTAL WATERS THIS MORNING IN ASSOCIATION WITH AN AREA OF DEEPER MOISTURE WHICH IS APPROACHING THE UPPER TEXAS COAST. FURTHER TO THE SOUTH...TD 5 HAS STRENGTHENED INTO TROPICAL STORM DOLLY THIS MORNING. THE CENTER OF THE SYSTEM HAS FORMED A BIT FURTHER NORTH THAT PREVIOUSLY EXPECTED WHICH HAS CAUSED A CORRESPONDING SHIFT IN THE FORECAST TRACK. THE ONLY ADDITIONAL IMPACTS TO SOUTHEAST TEXAS WILL BE SOME SLIGHTLY HIGHER SEAS OFFSHORE AS THE NEW TRACK STILL TAKES THE SYSTEM INTO MEXICO WELL SOUTH OF THE BORDER. EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP INLAND LATER THIS MORNING AS MOISTURE STREAMS BACK INTO THE REGION. COVERAGE SHOULD INCREASE ACROSS OUR NORTHERN COUNTIES LATE THIS AFTERNOON AS A PASSING SHORTWAVE BRINGS ADDITIONAL LIFT TO THE REGION. GIVEN THE RICH MOISTURE A FEW BRIEF HEAVY DOWNPOURS WILL BE POSSIBLE WITH THE ACTIVITY TODAY. HIGH TEMPERATURES SHOULD REMAIN IN THE LOW TO MID 90S AREAWIDE WITH THE PRECIPITATION AND GREATER CLOUD COVER. ONLY SLIGHT CHANGES FOR THE MID TO EXTENDED RANGE FORECAST THIS MORNING. THE UPPER LEVEL PATTERN OVERHEAD REMAINS RELATIVELY UNCHANGED THROUGH THE WEEK WITH A BROAD FLAT RIDGE ACROSS THE SOUTHERN UNITED STATES. THIS WILL ALLOW FOR CONTINUED DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS WITH HIGH TEMPERATURES IN THE LOW TO MID 90S...NEAR THE NORMALS FOR THE FIRST WEEK OF SEPTEMBER. 38 && MARINE... TROPICAL STORM DOLLY IS LOCATED IN THE BAY OF CAMPECHE EARLY THIS MORNING. BASED ON THE CURRENT FORECAST...DOLLY IS EXPECTED TO APPROACH THE COAST OF MEXICO BY TONIGHT AND MOVE INLAND BY WEDNESDAY MORNING. BUILDING SEAS CAN BE EXPECTED ALONG THE UPPER TEXAS COAST. CAUTION FLAGS ARE CURRENTLY IN EFFECT...AND ADVISORIES MIGHT BE NEEDED IF SEAS BUILD HIGHER THAN ANTICIPATED. PERIODS OF SHOWERS AND THUNDERSTORMS CAN BE EXPECTED ACROSS OUR AREA OVER THE NEXT COUPLE OF DAYS. TOWARD THE END OF THE WEEK...EXPECT WEAKENING ONSHORE WINDS AND LOWERING SEAS. 42 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 75 95 75 94 75 / 20 20 10 20 10 HOUSTON (IAH) 77 93 76 92 76 / 20 30 10 20 10 GALVESTON (GLS) 81 91 81 90 81 / 20 30 20 20 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 8 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...42 AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1232 PM CDT TUE SEP 2 2014 .AVIATION... THERE REMAINS A SMALL POSSIBILITY OF ISOLATED THUNDER DEVELOPING NEAR A WEAK FRONTAL BOUNDARY THAT WILL PULL UPSTATIONARY SOUTH OF A CLOVIS TO AMARILLO LINE. SUPPRESSION FROM UPPER LEVEL HIGH PRESSURE WILL FOR THE MOST PART HELP THE CAPPING INVERSION REMAIN STRONG...BUT MODELS STILL HAVE A WEAK SIGNAL OF SOME CONVECTION DEVELOPING IN AN AREA OF LOW LEVEL CONVERGENCE NEAR THE BOUNDARY. LONG STORY SHORT IS COVERAGE WILL BE VERY LIMITED...IF ANY AT ALL...AND WILL KEEP OUT OF BOTH TAFS. OTHER ITEM OF NOTE IS THE POSSIBILITY OF STRATUS MAKING A RUN INTO THE FCST AREA LATE TONIGHT. WILL GET THE BALL ROLLING BY INSERTING A TEMPO MVFR MENTION IN THE KLBB TAF. && .PREV DISCUSSION... /ISSUED 639 AM CDT TUE SEP 2 2014/ AVIATION... SOUTHERLY SURFACE WINDS AND VFR CONDITIONS SHOULD PREVAIL OVER MOST OF THE NEXT 24 HOURS. HOWEVER...THERE IS A SMALL CHANCE OF -TSRA IN THE VICINITY OF EITHER TERMINAL BETWEEN ABOUT 20 UTC AND 03 UTC. IN ADDITION...A WEAK FRONT COULD PRODUCE A TEMPORARY WIND SHIFT AT KCDS AROUND 14-15 UTC...BUT CONFIDENCE IS VERY LOW. PREV DISCUSSION... /ISSUED 355 AM CDT TUE SEP 2 2014/ SHORT TERM... 3 AM TEMPS WERE STILL IN THE LOWER 80S ACROSS MUCH OF THE SOUTHERN SOUTH PLAINS INTO THE ROLLING PLAINS...WHICH ISN/T SURPRISING GIVEN THE RECORD-SETTING WARMTH ACROSS THE AREA ON LABOR DAY. A WEAK COLD FRONT WAS LOCATED NEAR I-40...AND THERE WAS EVEN AN AREA OF LOW CLOUDS DEVELOPING NORTH OF THE FRONT ACROSS THE OKLA AND NRN TX PANHANDLES. ALOFT...A SHORTWAVE TROUGH IS MOVING FROM THE CENTRAL PLAINS INTO THE MIDWEST...WITH ONLY A WEAK REFLECTION INTO THE SRN HIGH PLAINS. THE FRONT IS EXPECTED TO MAKE SOME SWD PROGRESS THIS MORNING ACROSS THE WEST BEFORE STALLING/WASHING OUT THIS AFTERNOON...WITH A WEAK SURFACE LOW DEVELOPING ACROSS THE WESTERN SPLNS. THIS IN TURN SHOULD PRODUCE A WEAKLY CONVERGENT ZONE FROM THE CENTRAL SPLNS TO THE SOUTH-CENTRAL TX PANHANDLE...ALONG WITH A DIFFUSE DRYLINE. WITH LITTLE IF ANY UPPER-LEVEL SUPPORT...WE/LL HAVE TO RELY ON SURFACE-BASED LIFT TO GENERATE ANY MOIST CONVECTION TODAY. KLBB FCST SOUNDING SHOWS A WEAKLY CAPPED PROFILE THIS AFTERNOON...WITH NO CAP REMAINING FARTHER TO THE NORTH-NORTHEAST. THERE IS NOT A WHOLE LOT OF QPF SIGNAL IN MODEL SOLUTIONS...BUT THE 06 UTC HRRR AND RAP RUNS INDICATE ISOLATED DEVELOPMENT AS WELL AS THE SREF...WHICH SOMEWHAT BULLSEYES THE CAPROCK CANYONS AREA. WE WILL RUN WITH A 15-20 PERCENT CHANCE OF T-STORMS...CENTERED ACROSS BRISCOE COUNTY...AND ROUGHLY EXTENDING WEST TO I-27 AND SOUTH TO NEAR HWY 82. SHEAR APPEARS TO BE TOO WEAK TO SUPPORT MORE THAN PULSE-TYPE NON-SEVERE STORMS...BUT ML CAPES NEARING 2000 J/KG COULD SUPPORT SMALL HAIL...LOCALIZED WIND GUSTS TO 50 MPH...AND A BRIEF DOWNPOUR. STORMS SHOULD DIMINISH QUICKLY THIS EVENING WITH THE LOSS OF SFC-BASED INSTABILITY. SKIES SHOULD BE MOSTLY CLEAR TONIGHT ALTHOUGH SOME LOW STRATUS COULD INVADE FROM THE SOUTH EARLY WED MORNING. AS FOR TEMPS...FORTUNATELY WE SHOULD SEE THE HEAT OF THE PAST TWO DAYS BACK DOWN A BIT...ALTHOUGH WE WOULDN/T BE SURPRISED TO SEE A FEW LOCATIONS HIT 100 DEGREES IN THE LOW ROLLING PLAINS. HIGH TEMPS MAY ONLY REACH THE LOWER 90S IN THE FAR SW TX PANHANDLE DUE TO THE WEAK FRONT/S INFLUENCE...WITH MIDDLE TO UPPER 90S EXPECTED ELSEWHERE. LONG TERM... THE EXTENDED FORECAST FEATURES A WELCOME COOLING TREND EARLY ON WITH INCREASING RAIN CHANCES BY THE WEEKEND. INITIALLY...THE WESTERN EXTENT OF A LONGITUDINALLY BROAD UPPER RIDGE WILL HOLD SWAY OVER WEST TEXAS MID/LATE WEEK. THIS RIDGE WILL PROVIDE DRY AND WARM WEATHER...THOUGH DECREASING 1000-500 MB THICKNESSES AND 850 MB TEMPERATURES PROMISE A GRADUAL COOLING TREND. THINGS MAY EVENTUALLY BECOME MORE INTERESTING LATE WEEK INTO THE WEEKEND THOUGH THIS WILL BE AT LEAST PARTIALLY CONTINGENT ON WHETHER OR NOT A COLD FRONT MOVING THROUGH THE PLAINS CAN SETTLE INTO THE SOUTH PLAINS. THE COLD FRONT WILL MAKE ITS FIRST RUN SOUTHWARD BEHIND A POTENT SHORTWAVE TROUGH RIDING ACROSS THE NORTHERN TIER OF THE NATION AND SOUTHERN CANADA WEDNESDAY AND THURSDAY. CURRENT NWP HOLDS THE FRONT TO OUR NORTH ON FRIDAY...AS INCREASING AMOUNTS OF TROPOSPHERIC MOISTURE /POTENTIALLY ENHANCED BY REMNANTS OF DOLLY AND A TAP OFF A TROPICAL CYCLONE YET TO FORM IN THE EASTERN PACIFIC/ ARE FUNNELED AROUND THE RIDGE INTO THE DESERT SOUTHWEST. THE BEST RAIN CHANCES WILL LIKELY REMAIN FOCUSED TO NORTH AND WEST FRIDAY INTO FRIDAY NIGHT...AND WE HAVE DECREASED POPS SOMEWHAT OVER THIS PERIOD. THE LATEST ITERATION OF THE GFS AND ECMWF NOW TEND TO KEEP THE UPPER RIDGE CENTERED CLOSE ENOUGH THROUGH THE WEEKEND TO MAKE IT A LITTLE MORE UNCERTAIN WHETHER WE WILL FULLY BE ABLE TO TAP THE SUB-TROPICAL AND TROPICAL MOISTURE. EVEN SO...THE NWP SUGGESTS THE OUTFLOW AIDED FRONT WILL SAG INTO THE SOUTH PLAINS SOMETIME OVER THE WEEKEND /AS EARLY AS FRIDAY NIGHT WITH THE ECMWF OR NOT UNTIL SATURDAY NIGHT IN THE GFS/. REGARDLESS...IF THE FRONT CAN MAKE IT INTO THE CWA IT WILL BRING MORE SIGNIFICANT COOLING ALONG WITH ENHANCED RAIN CHANCES. GIVEN THE UNKNOWNS...WE HAVE NOT MADE MANY ADJUSTMENTS TO THE FORECAST OVER THE WEEKEND AND HAVE MAINTAINED THE HIGHEST POPS SATURDAY NIGHT...WHEN CONFIDENCE IS HIGHEST OF THE QUASI-STATIONARY FRONT RESIDING SOMEWHERE LOCALLY. THE FRONT WILL THEN LIFT BACK NORTHWARD EARLY NEXT WEEK AS PRESSURES FALL ACROSS THE HIGH PLAINS...DOWNSTREAM OF A WESTERN STORM SYSTEM. THIS WILL RESULT IN WARMER AND DRIER WEATHER FOR WEST TEXAS. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 92 64 93 64 89 / 10 10 10 10 10 TULIA 95 67 94 66 90 / 20 10 10 10 0 PLAINVIEW 94 66 93 67 90 / 20 10 0 0 0 LEVELLAND 95 67 93 67 89 / 10 10 10 10 10 LUBBOCK 97 70 93 68 90 / 10 10 0 0 0 DENVER CITY 97 67 93 67 89 / 10 10 10 10 10 BROWNFIELD 97 68 93 68 90 / 10 10 0 0 10 CHILDRESS 98 72 97 73 96 / 10 10 0 0 0 SPUR 97 69 96 71 93 / 10 10 0 0 10 ASPERMONT 98 73 98 73 96 / 10 10 0 0 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1218 PM CDT TUE SEP 2 2014 .AVIATION... /18Z TAFS/ Expect VFR conditions through the next 12 hours with gusty south southwest winds during the afternoon and early evening. the return of MVFR CIGS will be likely early tomorrow morning at KJCT, KBBD, and KSOA terminals. Low CIGS will burn off as we approach noon tomorrow. && .PREV DISCUSSION... /ISSUED 627 AM CDT TUE SEP 2 2014/ AVIATION... /12Z TAFS/ VFR conditions should prevail across most West Central Texas terminals through the period. However, we are seeing the expected MVFR stratus developing on low cloud imagery, although remaining pretty patchy at this point. Suspect that it will expand a little more through sunrise, and then quickly dissipate. Even at those locations it does effect, it will be a move in and out quickly type of feature. Otherwise, gusty south winds through daylight hours with just a scattered afternoon cu field developing. PREV DISCUSSION... /ISSUED 354 AM CDT TUE SEP 2 2014/ SHORT TERM... (Today and Tonight) Another mild night ongoing across West Central Texas, with south winds remaining strong enough to keep temperatures from dropping very much. Readings still right around 80 degrees at 3 AM (08Z). Models do indicate that some patchy low cloudiness will develop by sunrise and spread northward into the area, with low cloud satellite imagery showing some of this starting to develop across portions of Central Texas. Another hot day in store for the area, with the upper level ridge of high pressure in control. The 00Z NAM showed some convection across West Central Texas this afternoon, but the GFS is dry. Both the TTU WRF and the HRRR both show a similar pattern, scattered sea breeze activity pushing well inland today, but dissipating at sunset across Central Texas. Thus, will not insert PoPs into the forecast. After readings above the 100 degree mark at San Angelo and Abilene, models indicate a slight cooling at 850MB today as a little cooler and more moist air mass from the Gulf of Mexico slides into the area. Will keep afternoon highs below the 100 degree mark, but still a degree or two above guidance. Mild again tonight as south winds keep temperatures from dropping very quickly. Again, stayed just a little above guidance, as it has been too cool for the last several days. LONG TERM... Surface temperatures fall 2 to 3 degrees F Wednesday as 850 MB temperatures fall another 1 to 2 degrees Celsius. Tropical Storm Dolly in the Bay of Campeche is expected to move into Mexico early Wednesday, and may send weak disturbances/moisture northward to affect the I-10 corridor Thursday and Friday. This is indicated mainly by the EC model, as the GFS model is dry and the NAM model nearly so. Will keep rain chances out of forecast for this time period, given the uncertainty and limited agreement in the models. For Saturday night into Sunday, however, both the GFS and EC modes are still indicating a weak cold front to bring a slight chance of showers and thunderstorms. Forecast already has rain chances in for this time period, and will maintain them. && .PRELIMINARY POINT TEMPS/POPS... Abilene 100 76 96 74 95 / 5 5 5 5 5 San Angelo 98 75 95 74 94 / 5 5 10 10 10 Junction 95 77 93 74 93 / 10 10 10 10 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 99/99/18
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
436 PM MDT TUE SEP 2 2014 .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 420 PM MDT TUE SEP 2 2014 MAIN FORECAST CONCERN OVER THE NEXT FEW DAYS WILL BE THE CRITICAL FIRE WEATHER CONDITIONS ACROSS THE CWA. IT TOOK A LITTLE WHILE FOR RH VALUES TO DROP TO CRITICAL LEVELS THIS AFTERNOON...BUT WE ARE CURRENTLY SEEING A RH OF AROUND 15 PERCENT IN THE FOOTHILLS OF THE LARAMIE RANGE (FIRE WEATHER ZONES 309 AND 301). RH VALUES ARE GENERALLY 15-20 PERCENT TO THE WEST OF THE LARAMIE RANGE. WITH GUSTS TO 25-30 MPH THROUGH EARLY EVENING...THIS CONTINUES TO LOOK LIKE A MARGINAL RED FLAG EVENT AND WILL KEEP THE WARNINGS GOING. CLOUD COVER THIS AFTERNOON IS QUITE LIMITED WITH ONLY ISOLATED CUMULUS. SFC MOISTURE IS BETTER IN SOUTHERLY WINDS JUST TO THE EAST OF THE CWA (DEUEL AND GARDEN COUNTIES) BUT IT WILL BE TOUGH TO ADVECT THIS MOISTURE WESTWARD. THE HRRR MODEL ALONG WITH THE OTHER MODELS DO NOT SHOW ANY QPF OVER THE PANHANDLE TONIGHT SO WILL KEEP SLIGHT CHANE POPS OUT OF THE FCST. WEDNESDAY CONTINUES TO LOOK LIKE A MORE CRITICAL FIRE WEATHER DAY OVER THE REGION. A SHORTWAVE MOVING FROM WASHINGTON INTO MONTANA WILL INDUCE PRESSURE FALLS OVER WESTERN SOUTH DAKOTA WHICH STRENGTHENS THE PRESSURE GRADIENT OVER ESPECIALLY SOUTHEAST WY. MOS GUIDANCE SHOWS WINDS ABOUT 5 KTS HIGHER THAN THIS AFTN ALONG WITH AN ADDITIONAL 5 DEGREES OF WARMING. THE FIRE WEATHER WATCH FOR TOMORROW AFTN INCLUDES TWO ZONES (310 AND 306) THAT ARE NOT INCLUDED IN TODAYS RED FLAG WARNING. THIS LOOKS GOOD SINCE BOTH THESE ZONES WERE CLOSE TO HITTING THE CRITERIA TODAY AND CONDITIONS WILL BE DRIER AND MORE BREEZY TOMORROW. THE DEEP SOUTHWESTERLY FLOW WILL RESULT IN A VERY WARM DAY WITH HIGHS RISING INTO THE UPPER 80S TO MID 90S ACROSS THE PLAINS. THIS COULD BE ONE OF THE WARMEST DAYS FOR THE REST OF THE YEAR SINCE A COLD FRONTAL PASSAGE IS STILL PROGGED FOR THURS MORNING. TEMPS WILL DROP CLOSE TO 20 DEGREES ON THURS. STILL NO GOOD CHANCE OF PRECIP THROUGH AT LEAST THURS EVENING. COULD BE ISOLATED SHOWERS DEVELOPING BY THURS NIGHT ALTHOUGH THE MODEL TREND HAS BEEN TO SHIFT THE MORE WIDESPREAD RAIN WELL TO THE SOUTH OVER NORTHWEST KS. .LONG TERM...(FRIDAY THROUGH MONDAY NIGHT) ISSUED AT 420 PM MDT TUE SEP 2 2014 MODELS ARE IN FAIR AGREEMENT WITH THE MEDIUM RANGE PERIOD SHOWING A PERSISTENT QUASI-ZONAL PATTERN OVER THE CENTRAL CONUS. TEMPERATURES WILL START OFF BELOW AVERAGE ON FRIDAY IN THE POST FRONTAL AIRMASS...WITH THE SFC HIGH SLIDING TO THE SOUTHEAST ACROSS THE CENTRAL PLAINS. SFC WINDS ACROSS THE HIGH PLAINS WILL BE OUT OF THE SOUTHEAST AS THE SFC HIGH SLIDES SOUTHEAST...WITH CONVECTION DEVELOPING OVER THE MOUNTAINS IN THE LATE AFTERNOON IN THIS LLVL UPSLOPE REGIME. SHOULD STAY FAIRLY CAPPED ACROSS THE PLAINS WITHIN THE COOLER AIRMASS...BUT CANT RULE OUT SHOWERS/WEAK TSTORMS MAINTAINING AS THEY MOVE OFF THE MOUNTAINS AS A 70 KT JET AND SHORTWAVE ENERGY WILL BE MOVING OVERHEAD AT THIS TIME. SATURDAY LOOKS VERY SIMILAR ALBEIT WITH WEAKER UPSLOPE FLOW AND SLIGHTLY WARMER TEMPS/HIGH INSTABILITY. SUNDAY AND MONDAY COULD SEE A BIT MORE SUBTROPICAL MOISTURE ADVECT UP FROM THE SOUTHWEST AS A TROUGH DIGS ALONG THE WEST COAST AND MOVES ACROSS THE GREAT BASIN. THE DEEPEST MOISTURE LOOKS TO REMAIN TO OUR SOUTH...BUT CAN SEE SOME OF THIS MOISTURE MAKING IT UP TO SOUTHERN PORTIONS OF THE CWA SO WILL MAINTAIN AT LEAST SLIGHT CHANCE POPS FOR MUCH OF THE CWA. TEMPS WILL INCREASE BACK TO MORE NORMAL VALUES FOR THIS TIME OF YEAR BY MONDAY AS THE UPPER TROUGH DEEPENS AND A WARM AIR ADVECTION PATTERN DEVELOPS OVER THE ROCKIES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING) ISSUED AT 1149 AM MDT TUE SEP 2 2014 VFR CONDITIONS WILL PREVAIL AT ALL SITES THROUGH THE PERIOD. GUSTY SOUTHWEST WINDS WILL BE COMMON TODAY...WITH 20 TO 30 KTS POSSIBLE FOR WYOMING AND 15 TO 20 KTS AT THE NEBRASKA AIRPORTS. COULD SEE AN ISOLATED SHOWER NEAR KSNY LATE THIS AFTERNOON AND EVENING...BUT CONFIDENCE IS LOW THAT THIS WILL MATERIALIZE SO WILL LEAVE IT OUT OF THE TAF FOR NOW. WINDS WILL EASE THIS EVENING FOR MOST AREAS...WITH BREEZY CONDITIONS EXPECTED TO LINGER NEAR KCDR THROUGH THE EARLY OVERNIGHT PERIOD. GUSTY WINDS WILL RETURN ON WEDNESDAY. && .FIRE WEATHER... ISSUED AT 420 PM MDT TUE SEP 2 2014 RELATIVE HUMIDITY VALUES HAVE DROPPED TO AROUND 15 PERCENT THIS AFTERNOON OVER LOWER ELEVATIONS OF SOUTHEAST WYOMING. IN ADDITION...WEST AND SOUTHWEST WINDS HAVE BEEN GUSTING TO 20-30 MPH. A RED FLAG WARNING REMAINS IN EFFECT THROUGH EARLY THIS EVENING OVER PORTIONS OF SOUTHEAST WYOMING. TEMPERATURES WILL WARM ON WEDNESDAY AND WINDS WILL BE MORE BREEZY DURING THE AFTERNOON DUE TO A STRENGTHENING PRESSURE GRADIENT. THUS...EXPECT CRITICAL FIRE WEATHER CONDITIONS TO BE MORE WIDESPREAD OVER SOUTHEAST WYOMING AND FIRE WEATHER WATCHES ARE IN EFFECT. AN ELEVATED FIRE WEATHER THREAT IS PREDICTED OVER THE WESTERN NEBRASKA PANHANDLE DUE TO HUMIDITY VALUES FALLING TO 15-20 PERCENT AND WIND GUSTS OF 20-25 MPH DURING THE AFTERNOON. A COLD FRONT ON THURSDAY MORNING WILL PUSH ACROSS THE AREA WITH MUCH COOLER TEMPERATURES FOR THURSDAY AND INTO THE WEEKEND. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR WYZ301-302-304-306-309-310. RED FLAG WARNING UNTIL 7 PM MDT THIS EVENING FOR WYZ301-302-304- 309. NE...NONE. && $$ SHORT TERM...FINCH LONG TERM...RJM AVIATION...RJM FIRE WEATHER...FINCH