Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/05/13


AREA FORECAST DISCUSSION
NWS PUEBLO CO
1132 AM MDT FRI MAY 3 2013 .UPDATE... ISSUED AT 853 AM MDT FRI MAY 3 2013 UPDATED FORECAST TO TAKE DOWN THE FREEZE WARNING FOR THE REMAINDER OF THIS MORNING AS TEMPERATURES CONTINUE TO RISE ABOVE FREEZING. THERE IS STILL THE POTENTIAL FOR ANOTHER FROST OR FREEZE AGAIN TONIGHT SO CURRENT FREEZE WATCH FOR TONIGHT WILL REMAIN IN EFFECT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 300 AM MDT FRI MAY 3 2013 CURRENTLY...CLEAR SKIES WITH NORTHERLY FLOW ALOFT AS THE UPPER TROUGH SITS TO THE EAST OF COLORADO OVER KS AND NE...AS PER LATEST SATELLITE IMAGERY AND H5 RAP ANALYSIS. WIDESPREAD BELOW FREEZING TEMPS FOR THE EASTERN CO PLAINS AS OF 3 AM. TODAY AND TONIGHT...NOT A LOT TO ADD TO THE ONGOING FORECAST PACKAGE IN THE SHORT TERM. THE UPPER TROUGH TO THE EAST IS EXPECTED TO STRENGTHEN AS IT EJECTS TO THE SE AWAY FROM CO...RELAXING THE WINDS ALOFT FOR THE STATE. SUNNY TO MOSTLY SUNNY SKIES ARE EXPECTED TODAY...WITH A NICE REBOUND FOR TEMPS INTO THE UPPER 50S TO MID 60S FOR MOST LOCATIONS TODAY. LIGHT WINDS AND CLEAR SKIES TONIGHT WILL PRODUCE ONE MORE NIGHT AND SUB-FREEZING TEMPS...AND CURRENT FREEZE WATCH LOOKS GOOD. DECIDED TO HOLD OFF ON UPGRADING AT THIS TIME...AND TO AVOID CONFUSION OPTED TO LET CURRENT WARNING RUN THE COURSE...THEN AT EXPIRATION THE WATCH CAN BE UPGRADED. MOORE .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 300 AM MDT FRI MAY 3 2013 ...WETTER PATTERN POSSIBLE THIS PERIOD... SIMULATIONS IN RATHER GOOD AGREEMENT GIVEN THE RATHER WEAK FLOW REGIME WHICH WILL BE OVER THE WESTERN PART OF THE CONUS THIS PERIOD. AT THE BEGINNING OF THIS PD (SAT 12Z)...A WELL ESTABLISHED CUTOFF LOW WILL BE LOCATED IN THE VICINITY OF MISSOURI WHILE A WEAKER CLOSED LOW WILL BE DEVELOPING OVER THE S IDAHO REGION. WEAK RIDGING AND OVERALL WEAK MIDLVL FLOW WILL BE OVER THE FCST AREA. AS THE WEEKEND PROGRESSES...THE LOW OVER MISSOURI WILL SLOWLY MOVE EAST WHILE THE UPPER LOW OVER IDAHO RETROGRADES OVER N CALIF. THIS WILL ALLOW FOR A SMALL MIDLVL RIDGE TO BUILD OVER THE FCST AREA. GIVEN THIS PATTERN...I EXPECT IT WILL BE MAINLY DRY OVER THE REGION. A FEW SCTD AFTERNOON AND EVENING TSRA WILL BE POSSIBLE OVER THE CONTDVD AND AN ISOLATED STORM OR TWO WILL BE POSSIBLE OVER THE S MTNS/PIKES PEAK REGION. DAYTIME TEMPS WILL BE PLEASANT WITH MAINLY 60S ACROSS THE PLAINS AND VALLEYS. DURING THE MONDAY TIMEFRAME...A SHORTWAVE WILL EJECT OUT OF THE CALIF LOW AND MOVE ACROSS THE REGION. I EXPECT WE WILL SEE INCREASING CHANCES OF SHOWER OVER THE MTNS WITH ISOLATED SHOWERS BECOMING POSSIBLE OVER THE PLAINS LATE IN THE DAY. MAX TEMPS MONDAY WILL BE A FEW DEGREES WARMER THAN THE WEEKENDS HIGHS. SHEAR WILL BE INCREASING MONDAY (ALTHOUGH NOT ALL THAT STRONG)...SO WE MAY SEE A BIT MORE ORGANIZED CONVECTION ON THIS DAY ON THE PLAINS. TUESDAY...CALIF LOW STARTS TO MOVE EAST AND SIMULATIONS HINT AT A DRY SLOT AFFECTING THE S TIER OF THE CWA. THIS SHOULD BRING A DECREASING THREAT OF SHOWERS TO THE REGION AND ALLOW FOR TEMPS TO RISE INTO THE MID 70S ACROSS THE PLAINS WITH 60S VALLEYS. WEDNESDAY IS WHEN THE MAIN LOW MOVES OVER THE STATE...AND THIS IS THE DAY WE SHOULD SEE THE MOST ACTIVE WX. THERE IS NOT MUCH COLD AIR WITH THIS SYSTEM SO ALL PRECIP (EXCEPT OVER THE HIGHEST TRRN) SHOULD BE LIQUID. SHEAR IS FCST TO BE RATHER IMPRESSIVE (ESPECIALLY GFS) OVER THE FAR E PLAINS AND IT IS POSSIBLE WE MAY SEE OUR FIRST SEVERE WX THREAT OVER THE FCST AREA. THERE WILL ALSO BE A GOOD CHANCE OF PRECIP OVER THE ENTIRE AREA GIVEN THE EXPECTED INSTABILITY AND FORCING. FOR NOW I HAVE POPS IN THE 20-40% RANGE...BUT THESE VALUES MAY NEED TO BE INCREASED IF MODELS CONTINUE TO SHOW THIS SCENARIO. MAX TEMPS THIS DAY WILL BE COOLER GIVEN THE LIKELY INCREASED CLOUD COVER OVER THE FCST AREA. WED NITE THROUGH THU THE WEAK UPPER LOW MOVES VERY LITTLE AND WE SHOULD SEE A CONTINUED THREAT OF MUCH NEED PRECIP OVER THE FCST AREA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1122 AM MDT FRI MAY 3 2013 VFR CONDITIONS ARE EXPECTED AT KPUB...KCOS...AND KALS THROUGH 18Z SATURDAY WITH ONLY A FEW HIGH CLOUDS MOVING ACROSS SOUTHEASTERN COLORADO BY 20Z. -PJC && .PUB WATCHES/WARNINGS/ADVISORIES... FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR COZ084>089-093>099. && $$ UPDATE...KT SHORT TERM...MOORE LONG TERM...HODANISH AVIATION...PJC
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1018 AM MDT FRI MAY 3 2013 .UPDATE... && .SHORT TERM...ONGOING FORECASTS LOOK ON TRACK. HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS COLORADO DESPITE THE NORTHERLY FLOW ALOFT. WARMUP TO CONTINUE WITH HIGHS ACROSS NORTHEAST COLORADO AROUND 60 DEGREES. EXPECTED FORECAST HIGHS MAY NEED TO BE INCREASED A FEW DEGREES AS CURRENT TEMPERATURES ALREADY IN THE 40S ACROSS PLAINS. SOME INCREASE IN HIGH LEVEL CLOUDS AND WEAK NORTHERLY SURGE MAY SLOW WARMUP. WILL SEE HOW THINGS TRANSPIRE BEFORE MAKING ANY ADJUSTMENTS. .AVIATION...CURRENT TAF TRENDS LOOK REASONABLE. WEAK NORTHERLY SURGE STILL EXPECTED AROUND 18Z...AS NOTED BY LATEST RAP AND HRRR...WITH THE TREND TOWARD EASTERLY BY 00Z THEN SOUTHEAST DURING THE EVENING. VFR... && .HYDROLOGY... && .PREV DISCUSSION... /ISSUED 406 AM MDT FRI MAY 3 2013/ SHORT TERM...NORTHERLY FLOW ALOFT WILL PREVAIL TODAY AS AN UPPER LEVEL LOW SPINS OVER THE CENTRAL AND SOUTHERN PLAINS. FLOW ALOFT WILL NORTHWESTERLY AS A RIDGE STARTS TO FORM DUE TO A TROUGH MOVING SOUTHWEST ACROSS THE NORTHERN ROCKIES. FOR TODAY...AIRMASS CONTINUES TO RECOVER FROM THE COLD BLAST A COUPLE OF DAYS AGO. HIGHS WILL BE NEAR 60 DEGREES ACROSS NORTHEAST COLORADO. NORTH TO NORTHEAST WINDS WILL DEVELOP THIS AFTERNOON AS A SURFACE HIGH RESIDES OVER THE NORTHERN PLAINS. AS THIS HIGH SINKS SOUTH OVERNIGHT...IT WILL PUSH SLIGHTLY COOLER AIR INTO THE AREA FOR SATURDAY. BECAUSE OF THIS SURFACE HIGH SINKING SOUTH...THE NORMAL SOUTHERLY DRAINAGE WINDS WILL HAVE A HARD TIME DEVELOPING TONIGHT. OVERNIGHT LOWS WILL CONTINUE TO BE ON THE COOL SIDE FOR THIS TIME OF YEAR WITH READINGS AROUND 32 DEGREES. LONG TERM...CONTORTED JET STREAM PATTERN TAKES SHAPE OVER THE WRN CONUS OVER THE WEEKEND. BY SATURDAY...100+ KT JET DIVING SOUTH OUT OF WESTERN CANADA CARVES OUT A STRONG POSITIVELY TILTED UPPER LEVEL TROUGH OVER THE PACIFIC NORTHWEST/NORTHERN ROCKIES. AS THIS IS GOING ON...NEARLY ZONAL FLOW ALOFT SETS UP OVER COLORADO WITH A SHORTWAVE RIDGE FORMING TO OUR SOUTH. MEANWHILE POST-FRONTAL EAST-NORTHEAST LOW-LEVEL FLOW COUPLED WITH DIURNAL HEATING APPEARS TO PRODUCE LOW TOP CONVECTION OVER AND NEAR THE FRONT RANGE MTNS SATURDAY AFTERNOON. ANY PRECIP SHOULD BE LIGHT ACCORDING TO THE NAM AND GFS AND MOST OF THAT CONFINED TO THE HIGHER ELEVATIONS. BY SATURDAY EVENING COULD SEE SOME ENHANCEMENT IN THIS PRECIP WITH LOWERING CLOUD BASES GENERALLY ALONG AND WEST OF THE FRONT RANGE...WITH A WEAK MID-LEVEL DISTURBANCE MOVING UP FROM THE FOUR CORNERS. GFS IS A BIT MORE AMBITIOUS WITH ITS MOISTURE PROFILE AND THE AMOUNT OF PRECIP IT PRODUCES. STILL...PRECIP AMOUNTS SHOULD BE ON THE LOW SIDE. EXCEPT FOR A FEW SHOWERS DRIFTING OVR THE I-25 URBAN CORRIDOR DURING THE EVENING...DO NOT SEE ANY PRECIP FARTHER OUT ON THE PLAINS. ON SUNDAY...AS THE UPPER RIDGE TO OUR SOUTH CONTINUES TO AMPLIFY ..SO DOES THE SOUTHWEST FLOW CARRYING MID AND HIGH LEVEL MOISTURE UP FROM THE DESERT SOUTHWEST. THIS INCREASE IN FLOW IS IN RESPONSE TO THE STRONG JET SPINNING UP A DEEP CUTOFF LOW OFF THE CALIFORNIA COAST. THE SHIFT TO A MORE SOUTHERLY FLOW ALOFT AND A SOUTHEASTERLY LOW LEVEL FLOW ON THE PLAINS HELPS TO DRAWS MORE LOW AND MID-LEVEL MOISTURE UP INTO THE AREA RESULTING IN MORE CLOUDS MAINLY AT AND ABOVE MTN TOP LEVEL AND A SLIGHTLY BETTER CHANCE OF WETTING PRECIP FOR THE HIGH COUNTRY...AS WELL AS A SLIGHT CHANCE OF RAIN SHOWERS FOR THE URBAN CORRIDOR AND PALMER DIVIDE AREAS BY EVENING. TEMPERATURES IN THE 50S ON THE PLAIN SATURDAY ARE EXPECTED TO THE LOWER 60S ON SUNDAY. HIGH COUNTRY TEMPERATURE ABOUT THE SAME BOTH DAYS..IN THE 40S AND LOWER 50S. CLOUD COVER AND COOL TEMPERATURES WILL KEEP SNOWMELT RUNOFF IN THE HIGH COUNTRY IN CHECK. BY MONDAY...MODELS SHOW A ZONAL JET STREAM SNAKING ALONG THE U.S. MEXICO BORDER WITH COLORADO UNDER A MUCH WEAKER DIFLUENT SOUTHWEST FLOW ALOFT. LOW-LEVEL FLOW EAST OF THE MTNS REMAINS SOUTHEASTERLY. THROUGH THE DAY MODELS INDICATE YET ANOTHER EVEN STRONGER SHORTWAVE TROUGH ROTATING UP FROM THE SOUTHWEST WITHIN THE BROAD CIRCULATION AROUND THE WEST COAST CUTOFF LOW. WOULD EXPECT TO SEE SHOWERS ON THE INCREASE IN THE HIGH COUNTRY FROM SOUTH TO NORTH ON MONDAY AS THE SHORTWAVE TROUGH SWINGS NORTHWARD ACROSS THE REGION. SNOW LEVEL SHOULD REMAIN FAIRLY HIGH POSSIBLY UP AROUND 10500 OR 11000 FT WITH WARM ADVECTION. BY AFTERNOON WITH STEEP MID-LEVEL LAPSE RATES... ISOLATED T-STORMS ALSO A POSSIBILITY OVER THE HIGH TERRAIN. LATEST GUIDANCE SHOWS THE SHORT WAVE ENERGY AND MOISTURE PASSING OVER THE NORTHEAST PLAINS DURING THE EVENING. NOT SURE ABOUT ANY THUNDER. LOW POPS LOOK GOOD THERE. TEMPERATURES ON MONDAY WARM 1-2 DEG C FROM THE DAY BEFORE. TUESDAY AND BEYOND...PERIOD STARTS OUT DRY TUESDAY MORNING WITH WEAK DOWNWARD MOTION IN THE WAKE OF PASSING SHORTWAVE. FROM THERE...MODELS SHOW A GENERAL INCREASE IN MOISTURE AND LARGE SCALE LIFT WITH THE WEST COAST CYCLONE FINALLY MAKING ITS MOVE INLAND ACROSS THE GREAT BASIN. MODELS EVOLVE THIS CLOSED LOW INTO A BROAD LOW PRESSURE TROUGH WHICH SLOWLY MIGRATES EASTWARD ACROSS THE CENTRAL AND SOUTHERN ROCKY MTN REGIONS MIDWEEK. THIS WOULD KEEP TEMPERATURE AT OR BELOW AVERAGE AND THE WEATHER UNSETTLED WITH A CHANCE OF SHOWERS STARTING TUESDAY AFTERNOON OUT THROUGH THURSDAY. AT THIS TIME...TEMPERATURES APPEAR TOO WARM FOR ANY SNOW AT LOWER ELEVATIONS. AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH TONIGHT. NORMAL LIGHT SOUTHERLY DRAINAGE WINDS AT KDEN AND KAPA WILL BECOME LIGHT AFTER SUNRISE. BY 18Z...NORTH TO NORTHEAST WINDS WILL DEVELOP AT SPEEDS LESS THAN 15 KNOTS. LIGHT WINDS ARE EXPECT TO REDEVELOP TONIGHT. HYDROLOGY...NO CONCERNS. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...D-L LONG TERM....BAKER AVIATION...D-L
AREA FORECAST DISCUSSION
NWS PUEBLO CO
856 AM MDT FRI MAY 3 2013 .UPDATE... ISSUED AT 853 AM MDT FRI MAY 3 2013 UPDATED FORECAST TO TAKE DOWN THE FREEZE WARNING FOR THE REMAINDER OF THIS MORNING AS TEMPERATURES CONTINUE TO RISE ABOVE FREEZING. THERE IS STILL THE POTENTIAL FOR ANOTHER FROST OR FREEZE AGAIN TONIGHT SO CURRENT FREEZE WATCH FOR TONIGHT WILL REMAIN IN EFFECT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 300 AM MDT FRI MAY 3 2013 CURRENTLY...CLEAR SKIES WITH NORTHERLY FLOW ALOFT AS THE UPPER TROUGH SITS TO THE EAST OF COLORADO OVER KS AND NE...AS PER LATEST SATELLITE IMAGERY AND H5 RAP ANALYSIS. WIDESPREAD BELOW FREEZING TEMPS FOR THE EASTERN CO PLAINS AS OF 3 AM. TODAY AND TONIGHT...NOT A LOT TO ADD TO THE ONGOING FORECAST PACKAGE IN THE SHORT TERM. THE UPPER TROUGH TO THE EAST IS EXPECTED TO STRENGTHEN AS IT EJECTS TO THE SE AWAY FROM CO...RELAXING THE WINDS ALOFT FOR THE STATE. SUNNY TO MOSTLY SUNNY SKIES ARE EXPECTED TODAY...WITH A NICE REBOUND FOR TEMPS INTO THE UPPER 50S TO MID 60S FOR MOST LOCATIONS TODAY. LIGHT WINDS AND CLEAR SKIES TONIGHT WILL PRODUCE ONE MORE NIGHT AND SUB-FREEZING TEMPS...AND CURRENT FREEZE WATCH LOOKS GOOD. DECIDED TO HOLD OFF ON UPGRADING AT THIS TIME...AND TO AVOID CONFUSION OPTED TO LET CURRENT WARNING RUN THE COURSE...THEN AT EXPIRATION THE WATCH CAN BE UPGRADED. MOORE .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 300 AM MDT FRI MAY 3 2013 ...WETTER PATTERN POSSIBLE THIS PERIOD... SIMULATIONS IN RATHER GOOD AGREEMENT GIVEN THE RATHER WEAK FLOW REGIME WHICH WILL BE OVER THE WESTERN PART OF THE CONUS THIS PERIOD. AT THE BEGINNING OF THIS PD (SAT 12Z)...A WELL ESTABLISHED CUTOFF LOW WILL BE LOCATED IN THE VICINITY OF MISSOURI WHILE A WEAKER CLOSED LOW WILL BE DEVELOPING OVER THE S IDAHO REGION. WEAK RIDGING AND OVERALL WEAK MIDLVL FLOW WILL BE OVER THE FCST AREA. AS THE WEEKEND PROGRESSES...THE LOW OVER MISSOURI WILL SLOWLY MOVE EAST WHILE THE UPPER LOW OVER IDAHO RETROGRADES OVER N CALIF. THIS WILL ALLOW FOR A SMALL MIDLVL RIDGE TO BUILD OVER THE FCST AREA. GIVEN THIS PATTERN...I EXPECT IT WILL BE MAINLY DRY OVER THE REGION. A FEW SCTD AFTERNOON AND EVENING TSRA WILL BE POSSIBLE OVER THE CONTDVD AND AN ISOLATED STORM OR TWO WILL BE POSSIBLE OVER THE S MTNS/PIKES PEAK REGION. DAYTIME TEMPS WILL BE PLEASANT WITH MAINLY 60S ACROSS THE PLAINS AND VALLEYS. DURING THE MONDAY TIMEFRAME...A SHORTWAVE WILL EJECT OUT OF THE CALIF LOW AND MOVE ACROSS THE REGION. I EXPECT WE WILL SEE INCREASING CHANCES OF SHOWER OVER THE MTNS WITH ISOLATED SHOWERS BECOMING POSSIBLE OVER THE PLAINS LATE IN THE DAY. MAX TEMPS MONDAY WILL BE A FEW DEGREES WARMER THAN THE WEEKENDS HIGHS. SHEAR WILL BE INCREASING MONDAY (ALTHOUGH NOT ALL THAT STRONG)...SO WE MAY SEE A BIT MORE ORGANIZED CONVECTION ON THIS DAY ON THE PLAINS. TUESDAY...CALIF LOW STARTS TO MOVE EAST AND SIMULATIONS HINT AT A DRY SLOT AFFECTING THE S TIER OF THE CWA. THIS SHOULD BRING A DECREASING THREAT OF SHOWERS TO THE REGION AND ALLOW FOR TEMPS TO RISE INTO THE MID 70S ACROSS THE PLAINS WITH 60S VALLEYS. WEDNESDAY IS WHEN THE MAIN LOW MOVES OVER THE STATE...AND THIS IS THE DAY WE SHOULD SEE THE MOST ACTIVE WX. THERE IS NOT MUCH COLD AIR WITH THIS SYSTEM SO ALL PRECIP (EXCEPT OVER THE HIGHEST TRRN) SHOULD BE LIQUID. SHEAR IS FCST TO BE RATHER IMPRESSIVE (ESPECIALLY GFS) OVER THE FAR E PLAINS AND IT IS POSSIBLE WE MAY SEE OUR FIRST SEVERE WX THREAT OVER THE FCST AREA. THERE WILL ALSO BE A GOOD CHANCE OF PRECIP OVER THE ENTIRE AREA GIVEN THE EXPECTED INSTABILITY AND FORCING. FOR NOW I HAVE POPS IN THE 20-40% RANGE...BUT THESE VALUES MAY NEED TO BE INCREASED IF MODELS CONTINUE TO SHOW THIS SCENARIO. MAX TEMPS THIS DAY WILL BE COOLER GIVEN THE LIKELY INCREASED CLOUD COVER OVER THE FCST AREA. WED NITE THROUGH THU THE WEAK UPPER LOW MOVES VERY LITTLE AND WE SHOULD SEE A CONTINUED THREAT OF MUCH NEED PRECIP OVER THE FCST AREA. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 300 AM MDT FRI MAY 3 2013 VFR CONDITIONS ARE FORECAST FOR THE THREE MAIN TAF SITES OF KCOS...KPUB AND KALS FOR THE NEXT 24 HRS. && .PUB WATCHES/WARNINGS/ADVISORIES... FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR COZ084>089-093>099. FREEZE WARNING UNTIL 9 AM MDT THIS MORNING FOR COZ083>089- 093>099. && $$ UPDATE...KT SHORT TERM...MOORE LONG TERM...HODANISH AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
321 AM MDT FRI MAY 3 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 300 AM MDT FRI MAY 3 2013 CURRENTLY...CLEAR SKIES WITH NORTHERLY FLOW ALOFT AS THE UPPER TROUGH SITS TO THE EAST OF COLORADO OVER KS AND NE...AS PER LATEST SATELLITE IMAGERY AND H5 RAP ANALYSIS. WIDESPREAD BELOW FREEZING TEMPS FOR THE EASTERN CO PLAINS AS OF 3 AM. TODAY AND TONIGHT...NOT A LOT TO ADD TO THE ONGOING FORECAST PACKAGE IN THE SHORT TERM. THE UPPER TROUGH TO THE EAST IS EXPECTED TO STRENGTHEN AS IT EJECTS TO THE SE AWAY FROM CO...RELAXING THE WINDS ALOFT FOR THE STATE. SUNNY TO MOSTLY SUNNY SKIES ARE EXPECTED TODAY...WITH A NICE REBOUND FOR TEMPS INTO THE UPPER 50S TO MID 60S FOR MOST LOCATIONS TODAY. LIGHT WINDS AND CLEAR SKIES TONIGHT WILL PRODUCE ONE MORE NIGHT AND SUB-FREEZING TEMPS...AND CURRENT FREEZE WATCH LOOKS GOOD. DECIDED TO HOLD OFF ON UPGRADING AT THIS TIME...AND TO AVOID CONFUSION OPTED TO LET CURRENT WARNING RUN THE COURSE...THEN AT EXPIRATION THE WATCH CAN BE UPGRADED. MOORE .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 300 AM MDT FRI MAY 3 2013 ...WETTER PATTERN POSSIBLE THIS PERIOD... SIMULATIONS IN RATHER GOOD AGREEMENT GIVEN THE RATHER WEAK FLOW REGIME WHICH WILL BE OVER THE WESTERN PART OF THE CONUS THIS PERIOD. AT THE BEGINNING OF THIS PD (SAT 12Z)...A WELL ESTABLISHED CUTOFF LOW WILL BE LOCATED IN THE VICINITY OF MISSOURI WHILE A WEAKER CLOSED LOW WILL BE DEVELOPING OVER THE S IDAHO REGION. WEAK RIDGING AND OVERALL WEAK MIDLVL FLOW WILL BE OVER THE FCST AREA. AS THE WEEKEND PROGRESSES...THE LOW OVER MISSOURI WILL SLOWLY MOVE EAST WHILE THE UPPER LOW OVER IDAHO RETROGRADES OVER N CALIF. THIS WILL ALLOW FOR A SMALL MIDLVL RIDGE TO BUILD OVER THE FCST AREA. GIVEN THIS PATTERN...I EXPECT IT WILL BE MAINLY DRY OVER THE REGION. A FEW SCTD AFTERNOON AND EVENING TSRA WILL BE POSSIBLE OVER THE CONTDVD AND AN ISOLATED STORM OR TWO WILL BE POSSIBLE OVER THE S MTNS/PIKES PEAK REGION. DAYTIME TEMPS WILL BE PLEASANT WITH MAINLY 60S ACROSS THE PLAINS AND VALLEYS. DURING THE MONDAY TIMEFRAME...A SHORTWAVE WILL EJECT OUT OF THE CALIF LOW AND MOVE ACROSS THE REGION. I EXPECT WE WILL SEE INCREASING CHANCES OF SHOWER OVER THE MTNS WITH ISOLATED SHOWERS BECOMING POSSIBLE OVER THE PLAINS LATE IN THE DAY. MAX TEMPS MONDAY WILL BE A FEW DEGREES WARMER THAN THE WEEKENDS HIGHS. SHEAR WILL BE INCREASING MONDAY (ALTHOUGH NOT ALL THAT STRONG)...SO WE MAY SEE A BIT MORE ORGANIZED CONVECTION ON THIS DAY ON THE PLAINS. TUESDAY...CALIF LOW STARTS TO MOVE EAST AND SIMULATIONS HINT AT A DRY SLOT AFFECTING THE S TIER OF THE CWA. THIS SHOULD BRING A DECREASING THREAT OF SHOWERS TO THE REGION AND ALLOW FOR TEMPS TO RISE INTO THE MID 70S ACROSS THE PLAINS WITH 60S VALLEYS. WEDNESDAY IS WHEN THE MAIN LOW MOVES OVER THE STATE...AND THIS IS THE DAY WE SHOULD SEE THE MOST ACTIVE WX. THERE IS NOT MUCH COLD AIR WITH THIS SYSTEM SO ALL PRECIP (EXCEPT OVER THE HIGHEST TRRN) SHOULD BE LIQUID. SHEAR IS FCST TO BE RATHER IMPRESSIVE (ESPECIALLY GFS) OVER THE FAR E PLAINS AND IT IS POSSIBLE WE MAY SEE OUR FIRST SEVERE WX THREAT OVER THE FCST AREA. THERE WILL ALSO BE A GOOD CHANCE OF PRECIP OVER THE ENTIRE AREA GIVEN THE EXPECTED INSTABILITY AND FORCING. FOR NOW I HAVE POPS IN THE 20-40% RANGE...BUT THESE VALUES MAY NEED TO BE INCREASED IF MODELS CONTINUE TO SHOW THIS SCENARIO. MAX TEMPS THIS DAY WILL BE COOLER GIVEN THE LIKELY INCREASED CLOUD COVER OVER THE FCST AREA. WED NITE THROUGH THU THE WEAK UPPER LOW MOVES VERY LITTLE AND WE SHOULD SEE A CONTINUED THREAT OF MUCH NEED PRECIP OVER THE FCST AREA. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 300 AM MDT FRI MAY 3 2013 VFR CONDITIONS ARE FORECAST FOR THE THREE MAIN TAF SITES OF KCOS...KPUB AND KALS FOR THE NEXT 24 HRS. && .PUB WATCHES/WARNINGS/ADVISORIES... FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR COZ084>089-093>099. FREEZE WARNING UNTIL 9 AM MDT THIS MORNING FOR COZ083>089- 093>099. && $$ SHORT TERM...MOORE LONG TERM...HODANISH AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
937 PM EDT Sat May 4 2013 .NEAR TERM [Rest of Tonight]... Updated at: 930 PM EDT The low-level cloud cover and light rain / drizzle appears to be lingering in the eastern half of our forecast area longer than the models have been indicating. Most of the MOS guidance is far too low with PoPs as some of the bands of light rain showers have produced several hundredths of an inch of rain in an hour. Therefore, the forecast overnight was weighted toward the CAM (convection-allowing models) guidance, and the locally-derived PoPs from those models. Cross sections of NAM and RUC fields from DTS-SAV show the sloped frontogenetic circulation in the low levels (surface to 800mb) gradually shifting east with time overnight. Therefore, PoPs and cloud cover were gradually decreased from west to east. The expected stratus lingering through 12z in the far east should lead to warmer low temperatures than MOS is indicating, especially east of 40J-ABY. Lows were nudged up a bit in those locations. && .SHORT TERM [Sunday through Monday]... The anomalous upper level low will steadily spin through the heart of the Southeast through the period. The low will provide plenty of forcing for showers both Sunday and Monday as impulses translate around the base of the low. The main limiting factor will be the dry air in the lower levels which will likely keep any rainfall rather light. Regardless, the wet pattern will continue until the upper low spirals out of the region sometime on Monday night. Aside from the continuing shower activity, temperatures will run 10, to even 15 degrees below average for some locations. Advancing clouds and rain will keep temperatures in check tomorrow, with a lower 70s to upper 70s northwest to southeast gradient in place. Overnight, lows will dip into the upper 40s in the wake of the showers. Monday will be the coldest afternoon as we are forecast to mix into the upper cold pool. Expect temperatures to remain around 70 degrees throughout Florida, and in the middle 60s across Georgia and Alabama, where clouds and rain will linger much of the day. With rain lingering into the night, overnight lows won`t be quite as cool, with around 50 degrees expected to the northwest, and up to 60 degrees across the southeast Big Bend of Florida. && .LONG TERM [Monday Night through Friday]... In the wake of the upper low, we will dry out an warm up quite a bit. No major weather systems are forecast to impact the local area, and temperatures will warm to seasonal averages by mid week. && .AVIATION [through 00z Monday]... Updated at: 930 PM EDT Skies have cleared at KDHN and KECP, well behind a slow-moving cold front. KABY, KTLH, and KVLD will continue with IFR cigs and MVFR vis (-RA/BR) this evening, but we expect clearing at KTLH around 06 UTC. KABY and KVLD will not clear until Sunday morning. Strong winds will develop Sunday afternoon as a strong mid tropospheric jet max rounds the base of a large, deep-layer low pressure system. W-WSW winds of 15 KT (gusts of 25-30 KT) are likely. Widely scattered SHRA are possible, but should not have much impact to ops. && .MARINE... Ongoing advisory conditions will continue through at least Monday morning as the disturbed pattern is forecast to bring a few fronts across our Gulf of Mexico waters. Cautionary conditions will then take over until Tuesday, when higher pressure and weaker gradients spread over the northern Gulf. && .FIRE WEATHER... Drier air will move into the area for Sunday and Monday, but red flag conditions are not expected. However, mixing heights, transport winds, and dispersions are expected to be high on both days. && .HYDROLOGY... With only light rain anticipated through mid week, do not expect any meaningful river or creek rises for the foreseeable future. All area rivers will remain below action stage, except the Apalachicola River at Blountstown which will bounce in and out of action stage over the next several days. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 46 77 48 71 56 / 40 30 10 20 20 Panama City 53 72 53 68 60 / 0 30 10 20 10 Dothan 43 71 46 68 50 / 10 30 20 40 20 Albany 47 74 47 68 52 / 90 30 20 40 30 Valdosta 54 76 48 70 55 / 90 20 10 30 30 Cross City 55 78 50 71 59 / 40 10 10 20 20 Apalachicola 52 73 52 68 61 / 10 30 10 20 20 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...Small Craft Advisory until 8 AM EDT Monday for Gulf of Mexico waters from Destin to the Suwannee River, out to 60 NM. && $$ NEAR TERM...Lamers SHORT TERM...Harrigan LONG TERM...Harrigan AVIATION...Fournier MARINE...Harrigan FIRE WEATHER...DVD HYDROLOGY...Harrigan
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
234 AM EDT FRI MAY 3 2013 .AVIATION... PATCHY TO DENSE FOG HAS DEVELOPED OVER THE INTERIOR AREAS OF SOUTH FLORIDA THIS MORNING. THE FOG COULD MOVE INTO THE TAF SITES OF KTMB...KAPF...KFXE...AND KMIA BETWEEN 09Z AND 12Z THIS MORNING. SO HAVE LOWER THE VIS AND CEILING INTO THE MVFR CONDITIONS FOR THE FOG. REST OF THE TAF SITES SHOULD REMAIN IN THE VFR CONDITIONS THROUGH THE EARLY MORNING HOURS OF TODAY. HOWEVER...KPBI TAF SITE COULD SEE SOME SHOWERS THROUGH THE EARLY MORNING HOURS OF TODAY. SO HAVE PUT IN VCSH FOR THIS SITE. THE WINDS WILL BE MAINLY FROM THE WEST DIRECTION AT SPEEDS OF 5 KNOTS OR LESS AT THE EAST COAST TAF SITES THROUGH THIS MORNING...EXCEPT KPBI WHERE THE WINDS WILL BE SWINGING FROM A NORTHEAST DIRECTION TO A NORTHWEST DIRECTION AT 5 MPH OR LESS AND AT KAPF WHERE THE WINDS WILL BE LIGHT AND VARIABLE. ALL OF THE TAF SITES SHOULD SEE SHOWERS BETWEEN 11Z AND 17Z BEFORE A CHANCE OF THUNDERSTORMS RETURN BETWEEN 17Z AND 00Z. SO HAVE PUT IN VCSH FOR ALL OF THE TAF SITES FOR THE MORNING HOURS AND VCTS FOR THE AFTERNOON HOURS FOR TODAY. THE WINDS WILL ALSO REMAIN IN A WESTERLY DIRECTION FOR THE DAY HOURS TODAY AROUND 10 KNOTS. AT THIS TIME WILL LEAVE THE CEILING AND VIS IN THE VFR CONDITIONS FOR THE DAY HOURS TODAY...DUE TO THE UNCERTAIN TIMING OF THE SHOWERS AND THUNDERSTORMS AFFECTING THE TAF SITES. && .AVIATION...54/BNB .PREV DISCUSSION... /ISSUED 959 PM EDT THU MAY 2 2013/ UPDATE... A CLEARING TREND CONTINUES ACROSS THE REGION WITH HEAVY SHOWERS AND THUNDERSTORMS EXITING THE LOCAL ATLANTIC WATERS TO THE EAST. HOWEVER...THERE IS STILL A STILL A CHANCE OF ADDITIONAL SHOWERS AND ISOLATED THUNDERSTORMS OVERNIGHT. THE OOZ SOUNDING INDICATED STEEP LOW LEVEL LAPSE RATES AND THERE IS A SURFACE TROUGH DEVELOPING IN THE EASTERN GULF WITH DEEPER LAYERED TROPICAL MOISTURE STILL LINGERING ACROSS THE REGION. SOME OF THE MESOSCALE MODEL GUIDANCE ALSO INDICATED POSSIBLE CONVECTION RETURNING TO THE ATLANTIC WATERS AND PORTIONS OF EASTERN SOUTH FLORIDA TONIGHT. && 60 PREV DISCUSSION... /ISSUED 747 PM EDT THU MAY 2 2013/ AVIATION... BULK OF PRECIPITATION HAS MOVED OFFSHORE IN ASSOCIATION WITH MESOSCALE LOW PRESSURE AREA, OR MESOLOW, WHICH MOVED ACROSS SOUTH FLORIDA THIS AFTERNOON. LEFTOVER MID/HIGH CLOUDS WILL MOVE THROUGH THE AREA BY 04Z WITH ONLY SCT CLOUDS AND VFR CONDITIONS OVERNIGHT. THE MESOLOW IS OFF THE SE FLORIDA COAST AS OF 00Z AND IS LIKELY CAUSING A TEMPORARY INCREASE IN NE WINDS TO 20-30 KNOTS ALONG THE EAST COAST. THESE WINDS SHOULD DECREASE LATER THIS EVENING AS THE LOW MOVES FARTHER OFFSHORE AND THE LARGE SCALE GRADIENT FLOW TAKES OVER. WINDS SHIFT TO SW ACROSS ALL OF SOUTH FLORIDA ON FRIDAY AS MAIN SFC LOW MOVES ACROSS THE AREA. SCATTERED TSTMS WILL RETURN TO THE AREA ON FRIDAY WITH VCTS INCLUDED AT ALL SITES. /MOLLEDA && PREV DISCUSSION... /ISSUED 501 PM EDT THU MAY 2 2013/ UPDATE... A SMALL CRAFT ADVISORY IS IN EFFECT FROM 2 AM THIS MORNING TO 200 PM FRIDAY FOR THE ATLANTIC WATERS TO THE EAST OF PALM BEACH COUNTY. THE COMBINATION OF WINDS FORECAST TO INCREASE TO THE 16 TO 21 KNOT RANGE AND A SMALL LONG PERIOD SWELL WILL RESULT IN SEAS TO NEAR 7 FEET MAINLY EXPECTED TO THE EAST OF PALM BEACH COUNTY. 60 PREV DISCUSSION... /ISSUED 324 PM EDT THU MAY 2 2013/ DISCUSSION... WIDESPREAD SHOWERS AND THUNDERSTORMS HAVE MOVED ACROSS SOUTH FLORIDA TODAY. A WELL DEVELOPED MCS/MCV WAS MOVING ACROSS SOUTH FLORIDA THIS AFTERNOON...AND SOME STORMS HAVE SHOWN ROTATION. THERE WERE REPORTS OF DAMAGE FROM A STORM IN BOCA RATON EARLIER THIS AFTERNOON AS WELL. SEVERE STREET FLOODING WAS REPORTED IN THE BOCA RATON AND DELRAY BEACH AREAS...WHERE OVER 7.5 INCHES OF RAIN HAS FALLEN. A SURFACE BOUNDARY APPEARED TO BE DRIFTING SOUTH AND IT WAS LOCATED ACROSS BROWARD COUNTY THIS AFTERNOON...AND LOCALLY HEAVY RAIN AND FLOODING WILL BE POSSIBLE ACROSS BROWARD AND MIAMI DADE COUNTY THROUGH THIS EVENING. AN UPPER LEVEL LOW ACROSS THE NORTHEASTERN GULF WILL CONTINUE TO SLIDE SOUTHEAST AND OPEN INTO A TROUGH OVERNIGHT AS IT MOVES INTO THE FLORIDA PENINSULA. UPPER LEVEL DIVERGENCE FROM THIS UPPER LOW MAY HELP STORMS CONTINUE INTO THE EVENING BEFORE DIMINISHING. THE HRRR SHOWS SHOWERS DISSIPATING AFTER 00Z THIS EVENING. SURFACE LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS THE EASTERN GULF OF MEXICO AND MOVE OVER SOUTH FLORIDA ON FRIDAY. THIS WILL ALLOW THE STEERING FLOW OVER SOUTH FLORIDA TO REMAIN LIGHT FROM A SOUTH TO SOUTHWEST DIRECTION KEEPING THE DEEP TROPICAL MOISTURE IN PLACE. SO SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS THE REGION AGAIN ON FRIDAY. THE EMPHASIS WILL BE FOR THE EAST COAST AND NORTHEAST COAST WHERE THE BEST LOW LEVEL CONVERGENCE AND THE SURFACE BOUNDARY WILL BE FOUND...ALONG WITH UPPER LEVEL FORCING ASSOCIATED WITH THE UPPER LEVEL FLOW. THE 500 MB TEMPS ON FRIDAY SHOULD BE A LITTLE BIT WARMER THAN TODAY...DUE TO THE UPPER LEVEL LOW DISSIPATING OVER THE NORTHEAST GULF OF MEXICO. HOWEVER...ANY STORMS THAT DO AFFECT SOUTH FLORIDA TONIGHT INTO FRIDAY WILL BE CAPABLE OF PRODUCING HEAVY RAINFALL. THE LOW WILL CONTINUE TO MOVE EAST OVER SOUTH FLORIDA ON SATURDAY BEFORE MOVING INTO THE WESTERN ATLANTIC WATERS ON SUNDAY. SLIGHTLY DRIER CONDITIONS ARE EXPECTED ON SATURDAY...BUT RAIN CHANCES WILL CONTINUE FOR THE NORTHERN TWO-THIRDS OF THE REGION. MUCH DRIER AIR WILL WORK INTO THE AREA FROM THE WEST ON SUNDAY. FOR EARLY TO MIDDLE OF NEXT WEEK...A MID TO UPPER LEVEL LOW WILL DEVELOP OVER THE TENNESSEE VALLEY AND MOVE SLOWLY EAST TOWARDS THE MID ATLANTIC STATES. THIS WILL ALLOW FOR DRIER WEATHER TO CONTINUE TO WORK INTO SOUTH FLORIDA FROM THE WEST. SO THE WEATHER SHOULD REMAIN DRY OVER SOUTH FLORIDA FOR THE EARLY TO MIDDLE PART OF NEXT WEEK. AVIATION... LIGHT TO MODERATE RAIN WILL CONTINUE AT KAPF AND KPBI THROUGH ABOUT 21-22Z. VERY HEAVY RAIN AND THUNDERSTORMS WILL CONTINUE FOR THE REST OF THE EAST COAST TAF SITES...WHERE IFR CONDITIONS MAY OCCUR. RAIN IS EXPECTED TO BEGIN DIMINISHING AFTER 04-06Z TONIGHT...WITH IMPROVING CONDITIONS. STORMS WILL BE POSSIBLE AGAIN BEGINNING LATE MORNING ON FRIDAY. WINDS WILL BE VARIABLE THE REST OF THIS AFTERNOON WITH GUSTY WINDS POSSIBLE. LIGHT AND VARIABLE WINDS ARE EXPECTED AFTER MIDNIGHT. WITH LOW PRESSURE MOVING OVER SOUTH FLORIDA...WESTERLY WINDS ARE EXPECTED ON FRIDAY. MARINE... THE WINDS OVER SOUTH FLORIDA TODAY INTO FRIDAY WILL BE FROM THE SOUTH TO SOUTHEAST DIRECTION AT 10 KNOTS OR LESS...BEFORE SLOWLY SWINGING TO A NORTHWEST DIRECTION BY LATE THIS WEEKEND AND INCREASING SPEEDS TO 10 TO 15 KNOTS. AT THE SAME TIME...A SMALL NORTHEAST SWELL OF 1 TO 3 FEET WILL CONTINUE TO AFFECT THE ATLANTIC WATERS OF SOUTH FLORIDA LATE THIS WEEK INTO THIS WEEKEND. THESE CONDITIONS WILL ALLOW FOR THE ATLANTIC SEAS TO REMAIN BELOW 6 FEET TODAY INTO THIS WEEKEND...EXCEPT FOR THE PALM BEACH WATERS WHERE THE SEAS COULD BUILD TO 6 FEET THIS WEEKEND. FOR THE GULF SIDE...THE SEAS WILL REMAIN BELOW 6 FEET TODAY INTO THIS WEEKEND. THE ONLY EXCEPTION IS THE OFFSHORE GULF WATERS WHERE THE SEAS COULD BUILD TO 6 FEET BY THIS WEEKEND. FIRE WEATHER... DEEP TROPICAL MOISTURE WILL REMAIN OVER THE REGION ON FRIDAY WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. SLIGHTLY DRIER AIR WILL BEGIN TO MOVE INTO THE REGION ON SATURDAY...WITH LESSER RAIN CHANCES. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 69 87 67 85 / 40 30 20 20 FORT LAUDERDALE 73 88 69 85 / 30 20 20 20 MIAMI 72 87 69 86 / 30 10 10 20 NAPLES 68 87 66 82 / 20 20 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR FAR SOUTH MIAMI DADE-GLADES-HENDRY-INLAND BROWARD-INLAND COLLIER- INLAND MIAMI DADE-INLAND PALM BEACH-MAINLAND MONROE. AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 PM EDT THIS AFTERNOON FOR COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM 20 NM TO 60 NM. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...13/SI AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1052 AM EDT FRI MAY 3 2013 .UPDATE... THE AVIATION SECTION HAS BEEN BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 345 AM EDT FRI MAY 3 2013 RAIN CHANCES WILL INCREASE ACROSS THE REGION THROUGH SUNDAY AS AN UPPER LOW CUTS OFF OVER THE SOUTHERN PLAINS TODAY...THEN STRENGTHENS AND DRIFTS SOUTHEAST INTO THE LOWER MISSISSIPPI VALLEY BY SUNDAY. THE UPPER LOW WILL MOVE THROUGH THE CAROLINAS EARLY NEXT WEEK AND OFF THE MID ATLANTIC COAST BY WEDNESDAY. HIGH PRESSURE WILL REESTABLISH ACROSS THE OHIO VALLEY WITH WARMER DRIER WEATHER RETURNING BY MIDWEEK. && .NEAR TERM /REST OF TODAY/... ISSUED AT 945 AM EDT FRI MAY 3 2013 MINOR TWEAKS MADE TO GRIDS...MAINLY SKY COVER...RAIN CHANCES AND TEMPERATURES BASED ON SATELLITE...RADAR AND CURRENT CONDITIONS. A COLD FRONT HAS PUSHED INTO THE NORTHWEST PART OF OUR FORECAST AREA. HOWEVER ALL MODELS BACK IT WEST INTO ILLINOIS THIS AFTERNOON AS LOW PRESSURE DEVELOPS OVER THE MID MISSISSIPPI VALLEY. WILL LOWER TEMPERATURES A DEGREE OR TWO NORTHWEST AND FAR WEST FOR THIS AFTERNOON. PREVIOUS NEAR TERM DISCUSSION FOLLOWS... ABUNDANCE OF MID AND HIGH LEVEL CLOUD COVER ACROSS CENTRAL INDIANA EARLY THIS MORNING. DEEPER MOISTURE NEAR AND WEST OF A QUASI- STATIONARY FRONTAL BOUNDARY NOW DRAPED ACROSS THE WABASH VALLEY SOUTHWEST INTO THE MISSISSIPPI RIVER VALLEY. TEMPERATURES WERE IN THE 60S OVER MUCH OF THE FORECAST AREA AT 07Z...WITH THE EXCEPTION OF UPPER 40S AND 50S OVER THE FAR NORTHWEST WHICH HAD SLIPPED BEHIND THE FRONT. FOCUS FOR TODAY WILL BE ON THE LOCATION OF THE FRONT AND POTENTIAL FOR CONVECTIVE DEVELOPMENT ACROSS CENTRAL INDIANA. UPPER TROUGH CONTINUING TO AMPLIFY OVER THE CENTRAL PLAINS THIS MORNING AND AS ENERGY ALOFT DIVES INTO THE TROUGH TODAY EXPECT IT TO AMPLIFY AND STRENGTHEN FURTHER...EVENTUALLY CUTTING OFF OVER SOUTHWEST MISSOURI BY THIS EVENING. AT THE SURFACE...NEARLY STATIONARY BOUNDARY OVER EXTREME WESTERN FORECAST AREA LIKELY TO MOVE LITTLE THROUGH THE MORNING BEFORE RETROGRADING BACK TO THE WEST INTO ILLINOIS THIS AFTERNOON AS THE UPPER LOW DEEPENS. SURFACE LOW PRESSURE CURRENTLY DEVELOPING OVER NORTHERN MISSISSIPPI EARLY THIS MORNING WILL LIFT NORTH THEN NORTHWEST ALONG THE BOUNDARY AND SHOULD BE NEAR KSTL BY THIS EVENING. REMAIN UNIMPRESSED IN POTENTIAL FOR WIDESPREAD RAINFALL FOR CENTRAL INDIANA TODAY AS BULK OF THE DEEPEST MOISTURE WILL REMAIN CONFINED ALONG AND TO THE WEST OF THE LOCATION OF THE BOUNDARY ALL DAY. PREDOMINANT SOUTHEASTERLY LOW LEVEL FLOW WILL MAINTAIN SOME DEGREE OF DRY AIR THROUGH THE BOUNDARY LAYER ACROSS MUCH OF THE REGION. LOW LEVEL CONVERGENCE AND ISENTROPIC LIFT WILL REMAIN FOCUSED TO THE SOUTHWEST OF THE FORECAST AREA TODAY AS A LOW LEVEL JET LIFTS INTO THE MID MISSISSIPPI VALLEY. PRESENCE OF A FEW MID LEVEL VORT LOBES ROTATING UP INTO THE REGION FROM THE SOUTH AND WEAK INSTABILITY LOOK TO BE THE MAIN CATALYSTS FOR CONVECTIVE DEVELOPMENT TODAY. WILL CARRY LIKELY POPS IN THE WABASH VALLEY THIS MORNING IN THE VICINITY OF THE BOUNDARY AND CHANCE POPS ELSEWHERE. LOW/MID LEVEL LAPSE RATES BRIEFLY INCREASE THIS AFTERNOON AND ALONG WITH THE INSTABILITY PRESENT...SHOULD BE ENOUGH TO GENERATE SCATTERED LOW TOPPED CONVECTION. TEMPS...LOW LEVEL THERMALS ARE SUPPORTIVE OF MOS GUIDANCE TODAY WITH HIGHS WARMING INTO THE 70S. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... ISSUED AT 345 AM EDT FRI MAY 3 2013 FORECAST CHALLENGES FOCUS ON POTENTIAL FOR RAIN AS THE UPPER LOW TRACKS FROM THE OZARKS E/SE INTO THE SOUTHEAST STATES BY SUNDAY NIGHT. OP GFS/GGEM/ECMWF ALL IN EXCELLENT AGREEMENT ON TRACK AND STRENGTH OF THE UPPER LOW THROUGH THE SHORT TERM WITH THE 00Z NAM BECOMING A SLOW OUTLIER BY SUNDAY. AFOREMENTIONED SURFACE LOW WILL GET PULLED AWAY FROM THE REGION TONIGHT AND SATURDAY BY THE UPPER LOW...WITH THE FRONTAL BOUNDARY BECOMING STRETCHED AND EVENTUALLY WASHING OUT ACROSS THE LOWER OHIO VALLEY BY LATE WEEKEND AS THE UPPER LOW MOVES INTO MISSISSIPPI. BEST CHANCES FOR WIDESPREAD RAINFALL TO IMPACT CENTRAL INDIANA WILL COME SATURDAY INTO EARLY SUNDAY AS DEEPER MOISTURE PIVOTS BACK NORTH INTO THE SOUTHERN HALF OF THE FORECAST AREA AND COMBINES WITH A PERIOD OF ISENTROPIC LIFT AND STRONG CONVERGENCE AT THE NOSE OF THE LOW LEVEL JET. AN AXIS OF MID LEVEL DEFORMATION ALSO COMES INTO PLAY ON SATURDAY AND ALIGNS JUST NORTH OF THE LOW LEVEL JET. CONFIDENCE IS HIGHEST IN HEAVIER RAINFALL IMPACTING THE LOWER WABASH VALLEY SATURDAY AND SATURDAY NIGHT...GRADUALLY DIMINISHING IN COVERAGE AND INTENSITY GOING NORTH/EAST ACROSS THE FORECAST AREA FURTHER AWAY FROM THE DEEPER PLUME OF MOISTURE AND BETTER FORCING. COULD SEE 1.5 TO 2 INCHES OF RAINFALL BY THE END OF THE WEEKEND OVER THE LOWER WABASH VALLEY...DROPPING TO A HALF INCH OR LESS ALONG AND NORTH/EAST OF INTERSTATE 74. WILL KEEP THUNDER MENTION OUT THROUGH THE PERIOD AS POOR LAPSE RATES AND LITTLE TO NO INSTABILITY OVER THE OHIO VALLEY. WILL CARRY LIKELY POPS OVER SOUTHERN COUNTIES WITH DECREASING POPS FURTHER NORTH/EAST. PRESENCE OF SUBSIDENCE AND DRIER AIR TRANSPORTING INTO THE LOWER GREAT LAKES FROM THE EAST WILL LIKELY CREATE A SHARP CUTOFF TO THE NORTHERN EXTENT OF THE PRECIP SHIELD. VERY DISTINCT POSSIBILITY THAT NORTHEAST COUNTIES SEE LITTLE TO NO RAINFALL TONIGHT THROUGH SUNDAY...ESPECIALLY IF MODEL TRENDS CONTINUE WITH THE MORE SOUTHERN TRACK TO THE UPPER LOW OVER THE WEEKEND. PRECIP COVERAGE WILL DIMINISH SUNDAY NIGHT AS DRIER AIR WRAPS AROUND THE BACK SIDE OF THE UPPER LOW AND INTO THE REGION. TEMPS...LEANED TOWARDS COOLER MAVMOS GUIDANCE ACROSS MUCH OF THE AREA FOR HIGHS SATURDAY. DID UNDERCUT TEMPS HOWEVER OVER THE LOWER WABASH VALLEY WITH EXPECTATION OF RAINFALL AND CLOUDS. UNDERCUT MOS OVER ENTIRE FORECAST AREA SUNDAY AS SIMILAR BOUNDARY LAYER TEMPS TO SATURDAY AND PRESENCE OF CLOUDS/RAIN SHOULD KEEP HIGHS A COUPLE DEGREES COOLER THAN GUIDANCE. WENT A DEGREE OR TWO WARMER ON LOWS TONIGHT AND SAT NIGHT AND NEAR MOS SUNDAY NIGHT. && .LONG TERM /MONDAY THROUGH THURSDAY/... ISSUED AT 345 AM EDT FRI MAY 3 2013 RAIN SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE SOUTHERN COUNTIES WILL BE POSSIBLE EARLY IN THE EXTENDED PERIOD AS A BROAD UPPER LEVEL LOW CONTINUES TO AFFECT CENTRAL INDIANA. THE GFS AND EURO ARE IN DECENT AGREEMENT WITH THE TRACK OF THE SYSTEM...TAKING THE UPPER LOW OVER THE SOUTHEAST U.S. AND AN ACCOMPANYING SURFACE LOW OVER THE TENNESSEE VALLEY. MODELS START TO DIFFER THOUGH ON THURSDAY AS THE EURO BRINGS ANOTHER UPPER LEVEL LOW OVER THE UPPER MIDWEST...AND THE GFS SHOWS RIDGING. FOR NOW...WILL STICK WITH LATEST INITIALIZATION WHICH INCREASES POPS FROM WEST TO EAST STARTING THURSDAY AFTERNOON. IN REGARD TO TEMPS...WAS ABLE TO CONTINUE WITH ALLBLEND...EXCEPT FOR MONDAY/S HIGHS WHICH NEEDED ADJUSTING DOWN DUE TO CLOUD COVER OVER THE SOUTH. && .AVIATION /DISCUSSION FOR THE 03/1500Z TAF ISSUANCE/... UPDATED TO REMOVE -TSRA FROM KHUF THIS AFTERNOON AND REPLACE WITH VCTS...AND ALSO PUSHED BACK VCTS BY A BIT AT THE SITES BASED ON RAP AND HRRR OUTPUT. PREVIOUS DISCUSSION FOLLOWS... ISSUED AT 1052 AM EDT FRI MAY 3 2013 SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS /MAINLY THIS AFTERNOON/ WILL IMPACT TAF SITES FOR DURATION OF TAF PERIOD AS A STATIONARY BOUNDARY REMAINS DRAPED OVER WESTERN PORTIONS OF CENTRAL INDIANA. NONETHELESS...ANTICIPATE VFR CONDITIONS TO BE THE PREVAILING FLIGHT CATEGORY WITH ONLY BRIEF DETERIORATION TO MVFR AT TIMES WITH HEAVIER SHOWERS/STORMS. THUNDERSTORMS SHOULD TAPER OFF WITH LOSS OF DAYTIME HEATING...SO ONLY CARRIED MENTION OF RAIN AFTER SAT 00Z. WINDS WILL BE SOUTHEASTERLY AT 8 TO 14 KTS. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN/JH SHORT TERM...RYAN LONG TERM....TDUD AVIATION...TDUD/CP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
110 AM EDT FRI MAY 3 2013 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 332 PM EDT THU MAY 2 2013 AN UPPER TROUGH OF LOW PRESSURE OVER THE GREAT PLAINS WILL DEEPEN INTO A CLOSED UPPER LOW AND TRACK INTO THE MID MISSISSIPPI VALLEY BY SATURDAY AND ACROSS TENNESSEE AND THE DEEP SOUTH SUNDAY AND MONDAY. IT WILL MOVE OFF THE MID ATLANTIC COAST BY THE MIDDLE OF NEXT WEEK AND HIGH PRESSURE WILL REBUILD ACROSS OUR REGION. THIS SYSTEM WILL BRING INCREASING CHANCE OF SHOWERS NEXT FEW DAYS...ESPECIALLY WEST AND SOUTH. && .NEAR TERM /REST OF TONIGHT/... ISSUED AT 1007 PM EDT THU MAY 2 2013 MAIN CHANGE OVER THE LAST SEVERAL UPDATES HAS BEEN TO TAILOR BACK POPS...ESPECIALLY ACROSS THE WESTERN COUNTIES WHERE ONLY A FEW ISOLATED THUNDERSTORMS ARE MOVING THROUGH. BELIEVE HRRR HAS THE BEST HANDLE ON POPS TONIGHT INTO FRIDAY AND LEANED TOWARD THIS GUIDANCE. AT THIS RATE BULK OF PRECIP WILL NOT REACH CENTRAL INDIANA UNTIL AT LEAST LATE MORNING FRIDAY...IF NOT LATER. PREVIOUS DISC FOLLOWS... RADAR HAS SHOWN AND INCREASE TO SHOWERS AND THUNDERSTORMS ACROSS ILLINOIS THIS AFTERNOON AS CAPES HAVE BEEN RUNNING FROM 1500 TO 2000 J/KG. SOME OF THESE MAY SPREAD INTO FAR WESTERN SECTIONS THIS EVENING AS AIRMASS IS SOMEWHAT UNSTABLE THERE. FATHER EAST WILL DOWNPLAY RAIN CHANCES SOME AS MODELS HAVE TENDED TO BE TOO QUICK IN SPREADING RAIN EAST TOO MUCH. LAPS SHOWS CAPES FROM INDY AND EASTWARD NO MORE THAN 200 J/KG AND SOME OF THE PREVIOUS MODELS INDICATED THAT IT COULD BE RAINING MUCH OF TODAY HERE AS WELL. FOR NOW WILL MENTION HIGH CHANCE POPS FAR WEST...AND SLIGHT CHANCES FROM INDY AND WESTWARD LATER TONIGHT. WHILE MOST EASTERN AREAS SHOULD REMAIN DRY. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO LOWER 60S WHICH IS CLOSE TO PERSISTENCE. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... ISSUED AT 332 PM EDT THU MAY 2 2013 FORECAST FOCUS CONTINUES TO BE ON RAIN CHANCES FRIDAY...AND OVER THE WEEKEND. MODELS DEEPEN THE UPPER TROUGH OVER THE PLAINS INTO A CLOSED UPPER LOW AND TRACK IT TOWARDS SOUTHERN TENNESSEE AND NORTHERN MISSISSIPPI. MODELS HAVE TRENDED A LITTLE FARTHER SOUTH WITH THE TRACK...ESPECIALLY THE GFS. AS A RESULT...IT LOOKS LIKE THE HEAVIEST RAINS WILL BE ACROSS OUR SOUTH AND ANY RAIN THAT MAKES IT INTO OUR NORTHEAST WILL BE LIGHT. ON FRIDAY WILL MENTION LIKELY POPS...FAR WEST...CHANCE POPS ELSEWHERE...BUT DRY OR SLIGHT CHANCE POPS FAR EAST. WENT CLOSER TO SLIGHTLY WARMER MET TEMPERATURES EAST AS THERE WILL STILL BE SOME SUN. THERE WILL BE BETTER CHANCES OF SHOWERS OVER THE WEEKEND CENTRAL AND SOUTH AS THE UPPER LOW MOVES A LITTLE CLOSER. WENT WITH LIKELY POPS FROM INDY AND SOUTH AND WEST AND CHANCE POPS ELSEWHERE. WENT CLOSE TO A MOS BLEND ON TEMPERATURES. HIGH TEMPERATURES COULD BE A LITTLE WARMER ACROSS OUR NORTHEAST...BECAUSE PRECIPITATION THERE WILL BE SCATTERED AT BEST. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... ISSUED AT 335 AM EDT THU MAY 2 2013 ENSEMBLES ARE SHOWING BETTER AGREEMENT ON A LARGE UPPER LOW SLOWLY PASSING ACROSS THE TENNESSEE VALLEY FROM WEST TO EAST DURING THE LONG TERM. SURFACE LOWS ARE STILL SHOWING QUITE A BIT OF SCATTER SUNDAY NIGHT BUT SEEM TO COME INTO BETTER AGREEMENT BY MONDAY NIGHT ON A LOCATION SOUTHEAST OF INDIANA AND MOVING FURTHER EAST AND AWAY FROM THE AREA BY MIDDAY TUESDAY. THIS SHOULD ALLOW FOR POPS TO DROP TO SLIGHT CHANCE OR LESS FROM MONDAY NIGHT ON. DURING THE DAYS SOME INSTABILITY MAKES ITS WAY INTO THE SOUTHERN COUNTIES SO INCLUDED A SLIGHT CHANCE OF THUNDER AT THAT TIME. SUNDAY NIGHT AND MONDAY THERE IS SUFFICIENT FORCING FROM THE PROXIMITY OF THE UPPER AND SURFACE LOWS TO JUSTIFY HIGH CHANCE POPS ACROSS THE SOUTH WITH LOWER CHANCES AS YOU HEAD NORTH. FOR TEMPERATURES GENERALLY WENT WITH ALLBLEND...WITH A SLIGHT ADJUSTMENT DOWN FOR HIGHS ON MONDAY WITH THE UPPER LOW TO THE SOUTH AND MOSTLY CLOUDY SKIES. && .AVIATION /DISCUSSION FOR THE 03/06Z TAFS/... ISSUED AT 107 AM EDT FRI MAY 3 2013 MAINLY VFR THROUGH THE PERIOD OUTSIDE OF SHOWERS/THUNDERSTORMS. BOUNDARY IS NEARLY STATIONARY JUST TO OUR NORTHWEST/WEST WITH WEAK LOW PRESSURE ALONG IT. THIS BOUNDARY SERVED AS FOCUS FOR SCATTERED CONVECTIVE DEVELOPMENT TO OUR WEST YESTERDAY AFTERNOON WITH SLOW AND ERRATIC STORM MOTIONS IN AN UNSTABLE BUT VERY WEAKLY SHEARED ENVIRONMENT. WITH LOSS OF HEATING...INTENSITY OF STORMS HAS BEEN STEADILY DIMINISHING...ONLY SHOWERS LIKELY TO REMAIN BY ISSUANCE TIME NEAR HUF/LAF...SO WILL CARRY VCSH THERE. OVERNIGHT IN GENERAL EXPECTING JUST AN INCREASE IN CLOUD COVER. WINDS WILL BECOME LESS THAN 10KT AT IND...LIGHT AND VARIABLE AT THE OUTLYING SITES. WILL CONTINUE WITH VCTS/CB MENTION TOMORROW AS THIS BOUNDARY SHOULD MAKE SOME VERY SLOW EASTWARD PROGRESS. WINDS WILL BE 8-12KT TOMORROW OUT OF THE SOUTHEAST. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...JH NEAR TERM...JH/SMF SHORT TERM...JH LONG TERM....CP AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1232 AM CDT FRI MAY 3 2013 .SYNOPSIS... ISSUED AT 351 PM CDT THU MAY 2 2013 12Z UA ANALYSIS HAS 850MB LOWS ALONG THE KS/MO BORDER AND ANOTHER IN WESTERN OKLAHOMA. A VERY STRONG 850MB THERMAL GRADIENT RAN FROM MN/WI DOWN TO OKLAHOMA AND WEST TEXAS. SATELLITE TRENDS THROUGH MID AFTERNOON SHOW THE LOW CLOUDS MAKING SLOW PROGRESS EASTWARD. RADAR SHOWS THE MAIN RAIN SHIELD OVER CENTRAL AND NORTHEAST IOWA WITH SCATTERED CONVECTION ACROSS ILLINOIS AND EASTERN IOWA. 18Z SFC ANALYSIS HAS WEAK LOWS FROM LOWER MICHIGAN BACK INTO NORTHEAST ARKANSAS WITH THE FRONT CONNECTING ALL THE LOWS. DEW POINTS ACROSS THE PLAINS AND PARTS OF THE UPPER MIDWEST WERE IN THE 20S AND 30S WITH 40S AND HIGHER FROM THE GREAT LAKES INTO THE LOWER MISSISSIPPI VALLEY. 08 && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 351 PM CDT THU MAY 2 2013 VERY DIFFICULT FCST. REFER TO THE CLIMATE SECTION FOR INFORMATION REGARDING MAY SNOW FOR SOME LOCATIONS. THE TRENDS WITH THE MODELS IS COLDER. THE MAIN PRECIPITATION SHIELD IS ALONG AND BEHIND THE 850MB FRONT. THE RAP AND WRF TRENDS HAVE THIS FRONT SLOWLY MOVING EAST TONIGHT. THUS RAIN WILL SLOWLY BREAK OUT AND INCREASE IN AREAL COVERAGE DURING THE EVENING HOURS. WBZ TEMPERATURES AND ACTUAL OBSERVATIONS SHOW TREMENDOUS EVAPORATIVE COOLING WILL OCCUR ACROSS THE FAR NORTHWEST AND WESTERN PARTS OF THE CWFA TONIGHT. FCST SOUNDINGS INDICATE RAIN BECOMING MIXED WITH AND THEN CHANGING OVER TO SLEET/SNOW MIXTURE. THE OVERALL FORCING AND WAA ALOFT IS SIGNIFICANT SO THERE WILL LIKELY BE ACCUMULATIONS ON GRASSY SURFACES EVEN THOUGH THE GROUND IS QUITE WARM. THEREFORE...WINTER WEATHER ADVISORIES HAVE BEEN RAISED FOR THE WESTERN TWO ROWS OF COUNTIES FROM HWY 92 ON NORTH. BUCHANAN...BENTON...IOWA...AND KEOKUK COUNTIES HAVE THE BEST CHANCE AT SEEING POTENTIALLY HISTORIC SNOWFALL FOR MAY. THE HIGHEST SNOWFALL AMOUNTS WILL BE IN THE WESTERN PARTS OF THESE COUNTIES. SNOW/SLEET AMOUNTS THERE COULD RANGE FROM 1 TO 4 INCHES. FURTHER EAST...ACROSS DELAWARE...LINN...JOHNSON...AND WASHINGTON COUNTIES THE CHANGE OVER TO SLEET WILL OCCUR DURING THE EVENING. IN THIS AREA MORE SLEET THAN SNOW IS EXPECTED WITH THE HIGHER AMOUNTS IN THE WESTERN PARTS OF THESE COUNTIES. SNOW/SLEET AMOUNTS IN THIS AREA COULD RANGE FROM A DUSTING TO 1 INCH. THE OVERALL LARGE PICTURE SUGGESTS THE POTENTIAL FOR SOME SLEET AS FAR EAST AS A DUBUQUE IOWA TO KAHOKA MISSOURI LINE DUE TO EVAPORATIVE COOLING. IN THIS AREA ONLY TRACE AMOUNTS ARE EXPECTED. ROUGHLY ALONG AND EAST OF THE MISSISSIPPI...SHOWERS WILL GIVE WAY TO A WIDESPREAD RAIN AS THE WAA INCREASES. FRIDAY...THE SNOW/SLEET MIXTURE IN THE FAR NORTHWEST/WEST PARTS OF THE CWFA WILL CHANGE BACK TO ALL RAIN AS WARM AIR ALOFT MOVES INTO THE AREA. ACROSS THE EASTERN CWFA THE OVERALL FORCING INCREASES AS A SFC WAVE MOVES UP FROM THE SOUTH. ALTHOUGH NOT INCLUDED IN THE FORECAST...THE LIFT TOOL SUGGESTS POSSIBLY SOME ISOLATED THUNDER OVER THE FAR SOUTHEAST AND EASTERN PARTS OF THE CWFA AS STRONG CONVERGENCE MOVES ALONG A THETA E GRADIENT. 08 .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 351 PM CDT THU MAY 2 2013 RECORD COLD RAIN...SLEET...SNOW EVENT MAIN CHALLENGE THIS FORECAST. OVERVIEW...INITIALIZATION AND VERIFICATION GOOD WITH MAIN ISSUE THE PHASING OF LATENT HEAT RELEASE AND STRONG EVAPORATIVE COOLING TO DETERMINE WHAT FAR WESTERN SECTIONS RECEIVE SLEET AND SNOW TONIGHT. VERIFICATION AT 18Z SUPPORTS FORCING AND THERMAL FIELDS OF 12Z NAM- WRF AND HI-RES ECMWF. THIS SUPPORTS SOME ACCUMULATIONS OF SNOW AND QUITE A BIT OF SLEET FAR WEST SECTIONS. HEAVY RAIN AND FORCING TOOLS SUGGEST MOST OF AREA TO PICK UP 1.5 TO LOCALLY AROUND 2.5 INCHES OF TOTAL PRECIPITATION NEXT 2-3 DAYS WITH MOST FALLING FRIDAY AND FRIDAY NIGHT. STRATIFORM NATURE AND AMOUNTS OVER LONGER TIME PERIOD SUPPORT MINOR RIVER ISSUES ON SOME RIVERS. FRIDAY NIGHT...KEPT CATEGORICAL POPS WITH DEEPLY OCCLUDING AND MATURING RAIN OF UPPER LOW TO DEPOSIT MOSTLY 1/3 TO 2/3 OF AN INCH WITH HEAVIEST OVER SW 1/2 TO 2/3 OF AREAL TEMPERATURES WITH MILDER AIR FROM EAST TO ALLOW TEMPERATURES TO BE NEARLY STEADY WITH LOWER 50S EAST TO MID/UPPER 40S FAR WEST. SATURDAY AND SUNDAY...MINOR CHANGES MADE. CONSIDERABLE CLOUDS WITH PERIODS OF LIGHT RAIN SATURDAY AND SATURDAY AND VERY LIGHT RAIN SUNDAY. A QUARTER INCH OR LESS ON SATURDAY MOST LOCATIONS WITH SPOTTY VERY LIGHT AMOUNTS SUNDAY. TEMPERATURES COOL WITH MOSTLY LOWER TO MIDDLE 60S AND MINS SATURDAY NIGHT IN THE MID/UPPER 40S. NICHOLS DAYS 4 THROUGH 7...SUNDAY NIGHT THROUGH THURSDAY... SUNDAY NIGHT THROUGH MONDAY NIGHT THE DEEP UPPER LOW GRADUALLY SHIFTS SOUTHEAST...AND A SURFACE RIDGE BUILDS INTO THE AREA TO CAUSE OUR SCATTERED SHOWERS TO SLOWLY DIMINISH IN COVERAGE...SO THAT BY MONDAY NIGHT WE SHOULD BE COMPLETELY DRY. TEMPERATURES TO REMAIN BELOW NORMAL WITH LOWS IN THE 40S. MONDAY HIGHS ARE CURRENTLY FORECAST TO RISE INTO THE UPPER 60S...BUT IT TOO MUCH CLOUD COVER IS LINGERING WILL HAVE TO LOWER THESE VALUES. TUESDAY AND TUESDAY NIGHT THE SURFACE RIDGE SLOWLY SHIFTS EAST ACROSS THE AREA...PRODUCING MAINLY DRY CONDITIONS AND GRADUALLY WARMING TEMPERATURES. AM CARRYING SOME DAYTIME SLIGHT CHANCE POPS IN THE SOUTHWEST CLOSEST TO THE LINGERING PLUME OF MOISTURE WHERE WE MIGHT GET SOME DIURNALLY DRIVEN SHOWERS. HIGHS TUESDAY SHOULD GET APPROACH 70 WITH 850MB TEMPERATURES GRADUALLY WARMING AS WELL. TUESDAY NIGHT MINS TO MODERATE TO AROUND 50. WEDNESDAY AND THURSDAY QUITE A BIT OF UNCERTAINTY RE-ENTERS THE FORECAST. WE WILL BE IN A SPLIT FLOW WITH A NORTHERN STREAM MAINLY AFFECTING SOUTHERN CANADA AND THE FAR NORTHERN CONUS...AND THE SOUTHERN STREAM MAINLY AFFECTING THE SOUTHERN CONUS. MODELS ARE DIVERGING IN THE HANDLING OF A SHORTWAVE THAT MOVES THROUGH THE NORTHERN STREAM...AND HOW MUCH IT PHASES WITH A CUT OFF LOW IN THE SOUTHERN STREAM OVER THE SOUTHWEST CONUS. THE ECMWF IS FASTER AND IS PHASING IT MORE...AND DRAGGING MORE MOISTURE UP INTO THE AREA...PRODUCING PRECIPITATION BEGINNING WEDNESDAY NIGHT. THE GFS IS SLOWER AND PHASES IT LESS...AND DOES NOT BRING PRECIPITATION INTO THE AREA UNTIL THURSDAY NIGHT. THUS...WHILE I AM CARRYING SOME SLIGHT CHANCE POPS BEGINNING ON WEDNESDAY...THESE ARE MORE FOR A CONTINUATION OF THE DIURNAL SHOWERS DURING THE DAY WITH THE GRADUALLY INCREASING MOISTURE. AM BRINGING IN SOME LOW CHANCE POPS FOR THURSDAY IN ASSOCIATION WITH THE NEW SHORTWAVE. TEMPERATURES TO CONTINUE TO WARM THROUGH AT LEAST WEDNESDAY NIGHT...WITH HIGHS ON WEDNESDAY INTO THE LOWER 70S. THURSDAY STILL FAIRLY WARM IN THE FORECAST BUT THIS MAY NEED TO BE LOWERED IF PRECIPITATION MOVES INTO THE AREA SOONER. LE && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1230 AM CDT FRI MAY 3 2013 AN AREA OF RAIN SHOWERS CONTINUES TO DEVELOP AND SPREAD NORTH AFFECTING EASTERN IOWA AND WESTERN ILLINOIS. THE RAIN CONTINUES TO INCREASE IN COVERAGE AND PERIODS OF RAIN ARE EXPECTED THROUGHOUT FRIDAY AS THE UPPER LEVEL SYSTEM MOVES INTO THE REGION. JUST A BIT FURTHER WEST A MIX OF WINTRY PRECIPITATION HAS BEEN REPORTED WITH SOME SLEET AND SNOW...AND LIGHT FREEZING RAIN AS FAR EAST AS KCID. THE MAIN BAND OF SNOW CONTINUES TO EDGE EAST FROM CENTRAL IOWA. HOWEVER THE WINTRY PRECIPITATION IS EXPECTED TO REMAIN WEST OF KDBQ. A RETURN TO LIQUID PRECIPITATION IS THEN FORECAST AS WARMER TEMPERATURES WORK BACK IN FROM EAST TO WEST BY MID FRIDAY MORNING. MAINLY IFR CONDITIONS ARE EXPECTED WITH POTENTIAL FOR LIFR CONDITIONS AT TIMES THROUGH FRIDAY. STOFLET && .CLIMATE... ISSUED AT 351 PM CDT THU MAY 2 2013 MAY SNOWFALL IN IOWA IS RARE. A VERY QUICK LOOK BACK AT PAST WEATHER RECORDS SUGGESTS THAT THE LAST TIME A FAIRLY WIDESPREAD SNOW OCCURRED IN MAY ACROSS IOWA WAS IN 1966. BELOW IS WHEN MEASURABLE SNOW AND/OR SLEET FELL IN MAY FOR SELECTED SITES. CEDAR RAPIDS #1 (MARION)... 0.2 INCHES 05/01/1997 FELL AS SLEET 0.3 INCHES 05/11/1966 DUBUQUE IOWA... 3.1 INCHES 05/01/1966 1.0 INCHES 05/07-08/1960 IOWA CITY WWTP... 0.2 INCHES 05/05/1944 MOLINE ILLINOIS... 0.3 INCHES ON 05/03/1935 TRACE ON 05/06/1989 TRACE ON 05/22/1917* * LATEST RECORDED SNOWFALL ON RECORD && .DVN WATCHES/WARNINGS/ADVISORIES... IA...WINTER WEATHER ADVISORY UNTIL 10 AM CDT THIS MORNING FOR BENTON- BUCHANAN-IOWA-KEOKUK. WINTER WEATHER ADVISORY UNTIL 8 AM CDT THIS MORNING FOR DELAWARE- JOHNSON-LINN-WASHINGTON. IL...NONE. MO...NONE. && $$ SYNOPSIS...08 SHORT TERM...08 LONG TERM...NICHOLS/LE AVIATION...STOFLET CLIMATE...08
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
107 PM EDT FRI MAY 03 2013 ...Updated Aviation Discussion... .Forecast Update... Issued at 1155 AM EDT Fri May 3 2013 12Z Models continue to advertise a sharp cutoff in precipitation on the northeast side of the large band of rain expected to setup as the upper low now over the Central Plains starts travelling southeast. Have begun to trim pops over the northeast forecast area, including a tweak downward for the Louisville area for tomorrow. Pops over the south still look pretty solid. Given the slow-moving nature of the line across our forecast area combined with heavy rains that fell earlier, as well as ensemble guidance indicating rivers across the south likely will go to flood stage, have decided to go ahead and issue a flood watch across south central Kentucky. Issued at 905 AM EDT Fri May 3 2013 Atmosphere much less capped than yesterday, as seen from the earlier showers we had over the northwest forecast area this morning. The limiting factor will be dry air over the east. The ARW and NMM versions of the WRF as well as the latest RAP all have a band of showers and storms forming at the edge of this dry air, which would be along the I-65 corridor, later this afternoon. As for the more steady rains coming in, models are fine tuning where the band will set up and move (slowly). There looks to be a sharp cutoff over the northeast, and the heaviest rains look to fall where we`ve had plenty of rain already in the last month. Given that earlier rain we may have to go with a flood watch across south central Kentucky and will decide after seeing the 12Z model data. Issued at 520 AM EDT Fri May 3 2013 Did a quick update to increase PoPs a bit across our western sections due to the batch of showers moving northward through southwestern Indiana. Also have some isolated showers that have popped up on the east side of I-65 as well, so have also expanded PoPs a little further east. && .Short Term (Now through Saturday)... Issued at 324 AM EDT Fri May 3 2013 In the near term, partly to mostly cloudy skies are expected to persist across the region. Early morning radar imagery shows a few isolated showers moving northward across our western CWA...mainly west of I-65. We expect the isolated showers to continue through the remainder of the early morning hours west of I-65. Temperatures remained quite mild with readings in the upper 50s in the southeast sections with lower 60s elsewhere. Temperatures will probably drop another 1-2 degrees before hitting their overnight minimums. Stalled out boundary out to our west is forecast to make very slow progress eastward today, mainly staying out near the Mississippi river. Southeasterly winds will pick up today as the pressure gradient increases across the region. Plenty of clouds are expected across the western half of the region today with a little less in the east. Moisture plume out ahead of the slow moving boundary will help generate waves of showers mainly to our west. Previous forecast has a very good handle here with isolated-scattered showers and possibly a thunderstorm or two mainly west of I-65 during the afternoon hours. Current data still supports this, so only some minor tweaks to the grids were made here. Temperatures this afternoon will warm into the mid-upper 70s with the highest temps out across the east where the veil of clouds is expected to be a bit thinner. By tonight, the frontal boundary out to the west is forecast to start making some eastward progress as the deep closed low out over the Plains gets more organized and deepens. Rain showers will be most concentrated out across our western sections and then overspread much of central Kentucky by sunrise Saturday. Light southeasterly flow and plenty of cloud cover will result in mild overnight minimum temperatures with readings cooling into the mid-upper 50s. Saturday, by all accounts, will be cloudy and wet across the region as the surface frontal boundary occludes across the region. Band of showers over western Kentucky is expected to gradually spread eastward across the central part of the state throughout the day. The rain will generally be light to moderate, but could be a little heavy at times especially across southern Kentucky. Instability is virtually not existent so not expecting much in the way of thunder. However, with the good moisture fetch off the SW Atlantic, training of rain showers looks increasingly likely which could lay down around an inch of rain in some spots by Saturday evening. The clouds and precipitation will keep temperatures down on Saturday with highs only warming into the upper 50s. .Long Term (Saturday Night through Thursday)... Issued at 300 AM EDT Fri May 3 2013 The well advertised cutoff upper level low will be over Arkansas at the beginning of the long term. This low will slowly swing across the southeastern CONUS and into northern GA by Monday morning. It will then work its way up the Atlantic coast through mid week. The fetch of moisture off the Atlantic will continue to wrap around the northern side of the low as it slides south of the forecast area through the end of the weekend. Moderate rain will continue across much of the area Saturday night through Sunday. Through this time period an rainfall totals look to range from half an inch across portions of the Bluegrass and southern Indiana to an inch south of the Bluegrass Parkway. Some minor flooding will be possible on area rivers with this rain. For more information refer to the hydrology discussion below. Rain chances will continue off and on through the first half of the work week. However, these will become more diurnal in nature as the low moves up the coast. A few thunderstorms will be possible with this activity, especially if the sun is able to break out at all. Thursday finally looks to be dry under ridging aloft. Temperatures will remain on the cool side Sunday with highs only in the lower 60s. However we will see a warming trend through the week. By Thursday high temperatures should be back into the upper 70s with lows in the mid to upper 50s. && .Aviation (18Z TAF Issuance)... Issued at 105 PM EDT Fri May 3 2013 Stalled frontal boundary remains out to our west, but we should start to see some movement this period, as a developing upper low over the Central Plains drifts southeast into Arkansas tonight. We may see an isolated storm this afternoon, as moisture starts to increase ahead of this system. However coverage looks isolated enough to leave out of each of the terminals for now. High-res models continue to show some storms along a NW/SE-oriented band near KSDF later this afternoon, but would prefer to wait and see development before adding to the TAFs. More solid rain chances will start, first at KBWG late tonight then at KSDF Saturday morning. Have enough confidence in at least MVFR conditions as we get deeper into the moisture, so put these in 6-7 hours after the showery activity starts. && .Hydrology... Issued at 300 PM EDT Thu May 2 2013 An upper air disturbance is forecast to move across the region this weekend. This will result in moderate to heavy rainfall over southern Kentucky. Between Friday afternoon and Sunday morning between one and inch inches could fall with the heaviest amounts near Bowling Green. This area recently had minor flooding and this new rain could result in a new round of flooding in the middle of the Green River Basin. Residents with livestock or equipment in flood prone areas should watch water levels closely this weekend. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...NONE. KY...FLOOD WATCH FROM SATURDAY MORNING THROUGH SUNDAY EVENING FOR KYZ026-027-061>066-070>078-081-082. $$ Updates..........RJS Short Term.......MJ Long Term........EER Aviation.........RJS Hydrology........CMC
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1158 AM EDT FRI MAY 03 2013 .Forecast Update... Issued at 1155 AM EDT Fri May 3 2013 12Z Models continue to advertise a sharp cutoff in precipitation on the northeast side of the large band of rain expected to setup as the upper low now over the Central Plains starts travelling southeast. Have begun to trim pops over the northeast forecast area, including a tweak downward for the Louisville area for tomorrow. Pops over the south still look pretty solid. Given the slow-moving nature of the line across our forecast area combined with heavy rains that fell earlier, as well as ensemble guidance indicating rivers across the south likely will go to flood stage, have decided to go ahead and issue a flood watch across south central Kentucky. Issued at 905 AM EDT Fri May 3 2013 Atmosphere much less capped than yesterday, as seen from the earlier showers we had over the northwest forecast area this morning. The limiting factor will be dry air over the east. The ARW and NMM versions of the WRF as well as the latest RAP all have a band of showers and storms forming at the edge of this dry air, which would be along the I-65 corridor, later this afternoon. As for the more steady rains coming in, models are fine tuning where the band will set up and move (slowly). There looks to be a sharp cutoff over the northeast, and the heaviest rains look to fall where we`ve had plenty of rain already in the last month. Given that earlier rain we may have to go with a flood watch across south central Kentucky and will decide after seeing the 12Z model data. Issued at 520 AM EDT Fri May 3 2013 Did a quick update to increase PoPs a bit across our western sections due to the batch of showers moving northward through southwestern Indiana. Also have some isolated showers that have popped up on the east side of I-65 as well, so have also expanded PoPs a little further east. && .Short Term (Now through Saturday)... Issued at 324 AM EDT Fri May 3 2013 In the near term, partly to mostly cloudy skies are expected to persist across the region. Early morning radar imagery shows a few isolated showers moving northward across our western CWA...mainly west of I-65. We expect the isolated showers to continue through the remainder of the early morning hours west of I-65. Temperatures remained quite mild with readings in the upper 50s in the southeast sections with lower 60s elsewhere. Temperatures will probably drop another 1-2 degrees before hitting their overnight minimums. Stalled out boundary out to our west is forecast to make very slow progress eastward today, mainly staying out near the Mississippi river. Southeasterly winds will pick up today as the pressure gradient increases across the region. Plenty of clouds are expected across the western half of the region today with a little less in the east. Moisture plume out ahead of the slow moving boundary will help generate waves of showers mainly to our west. Previous forecast has a very good handle here with isolated-scattered showers and possibly a thunderstorm or two mainly west of I-65 during the afternoon hours. Current data still supports this, so only some minor tweaks to the grids were made here. Temperatures this afternoon will warm into the mid-upper 70s with the highest temps out across the east where the veil of clouds is expected to be a bit thinner. By tonight, the frontal boundary out to the west is forecast to start making some eastward progress as the deep closed low out over the Plains gets more organized and deepens. Rain showers will be most concentrated out across our western sections and then overspread much of central Kentucky by sunrise Saturday. Light southeasterly flow and plenty of cloud cover will result in mild overnight minimum temperatures with readings cooling into the mid-upper 50s. Saturday, by all accounts, will be cloudy and wet across the region as the surface frontal boundary occludes across the region. Band of showers over western Kentucky is expected to gradually spread eastward across the central part of the state throughout the day. The rain will generally be light to moderate, but could be a little heavy at times especially across southern Kentucky. Instability is virtually not existent so not expecting much in the way of thunder. However, with the good moisture fetch off the SW Atlantic, training of rain showers looks increasingly likely which could lay down around an inch of rain in some spots by Saturday evening. The clouds and precipitation will keep temperatures down on Saturday with highs only warming into the upper 50s. .Long Term (Saturday Night through Thursday)... Issued at 300 AM EDT Fri May 3 2013 The well advertised cutoff upper level low will be over Arkansas at the beginning of the long term. This low will slowly swing across the southeastern CONUS and into northern GA by Monday morning. It will then work its way up the Atlantic coast through mid week. The fetch of moisture off the Atlantic will continue to wrap around the northern side of the low as it slides south of the forecast area through the end of the weekend. Moderate rain will continue across much of the area Saturday night through Sunday. Through this time period an rainfall totals look to range from half an inch across portions of the Bluegrass and southern Indiana to an inch south of the Bluegrass Parkway. Some minor flooding will be possible on area rivers with this rain. For more information refer to the hydrology discussion below. Rain chances will continue off and on through the first half of the work week. However, these will become more diurnal in nature as the low moves up the coast. A few thunderstorms will be possible with this activity, especially if the sun is able to break out at all. Thursday finally looks to be dry under ridging aloft. Temperatures will remain on the cool side Sunday with highs only in the lower 60s. However we will see a warming trend through the week. By Thursday high temperatures should be back into the upper 70s with lows in the mid to upper 50s. && .Aviation (12Z TAF Issuance)... Issued at 643 AM EDT Fri May 3 2013 Nearly stationary frontal boundary out near the MS river will remain out to our west throughout the day. VFR conditions are expected at all the terminals today with southeast winds picking up during the mid-morning hours. The pressure gradient is expected to increase as a deep upper low continues to strengthen over the Plains. Southeast winds of 10-15 mph with gusts up to 20 mph will be possible later this afternoon. A few waves of low pressure will move up along the frontal boundary producing a few rounds of showers later today. The vast majority of this activity will stay west of KBWG and KSDF this afternoon. Coverage still looks rather sparse enough to preclude mention in this TAF forecast at the moment. && .Hydrology... Issued at 300 PM EDT Thu May 2 2013 An upper air disturbance is forecast to move across the region this weekend. This will result in moderate to heavy rainfall over southern Kentucky. Between Friday afternoon and Sunday morning between one and inch inches could fall with the heaviest amounts near Bowling Green. This area recently had minor flooding and this new rain could result in a new round of flooding in the middle of the Green River Basin. Residents with livestock or equipment in flood prone areas should watch water levels closely this weekend. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...NONE. KY...FLOOD WATCH FROM SATURDAY MORNING THROUGH SUNDAY EVENING FOR KYZ026-027-061>066-070>078-081-082. $$ Updates..........MJ/RJS Short Term.......MJ Long Term........EER Aviation.........MJ Hydrology........CMC
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
908 AM EDT FRI MAY 03 2013 .Forecast Update... Issued at 905 AM EDT Fri May 3 2013 Atmosphere much less capped than yesterday, as seen from the earlier showers we had over the northwest forecast area this morning. The limiting factor will be dry air over the east. The ARW and NMM versions of the WRF as well as the latest RAP all have a band of showers and storms forming at the edge of this dry air, which would be along the I-65 corridor, later this afternoon. As for the more steady rains coming in, models are fine tuning where the band will set up and move (slowly). There looks to be a sharp cutoff over the northeast, and the heaviest rains look to fall where we`ve had plenty of rain already in the last month. Given that earlier rain we may have to go with a flood watch across south central Kentucky and will decide after seeing the 12Z model data. Issued at 520 AM EDT Fri May 3 2013 Did a quick update to increase PoPs a bit across our western sections due to the batch of showers moving northward through southwestern Indiana. Also have some isolated showers that have popped up on the east side of I-65 as well, so have also expanded PoPs a little further east. && .Short Term (Now through Saturday)... Issued at 324 AM EDT Fri May 3 2013 In the near term, partly to mostly cloudy skies are expected to persist across the region. Early morning radar imagery shows a few isolated showers moving northward across our western CWA...mainly west of I-65. We expect the isolated showers to continue through the remainder of the early morning hours west of I-65. Temperatures remained quite mild with readings in the upper 50s in the southeast sections with lower 60s elsewhere. Temperatures will probably drop another 1-2 degrees before hitting their overnight minimums. Stalled out boundary out to our west is forecast to make very slow progress eastward today, mainly staying out near the Mississippi river. Southeasterly winds will pick up today as the pressure gradient increases across the region. Plenty of clouds are expected across the western half of the region today with a little less in the east. Moisture plume out ahead of the slow moving boundary will help generate waves of showers mainly to our west. Previous forecast has a very good handle here with isolated-scattered showers and possibly a thunderstorm or two mainly west of I-65 during the afternoon hours. Current data still supports this, so only some minor tweaks to the grids were made here. Temperatures this afternoon will warm into the mid-upper 70s with the highest temps out across the east where the veil of clouds is expected to be a bit thinner. By tonight, the frontal boundary out to the west is forecast to start making some eastward progress as the deep closed low out over the Plains gets more organized and deepens. Rain showers will be most concentrated out across our western sections and then overspread much of central Kentucky by sunrise Saturday. Light southeasterly flow and plenty of cloud cover will result in mild overnight minimum temperatures with readings cooling into the mid-upper 50s. Saturday, by all accounts, will be cloudy and wet across the region as the surface frontal boundary occludes across the region. Band of showers over western Kentucky is expected to gradually spread eastward across the central part of the state throughout the day. The rain will generally be light to moderate, but could be a little heavy at times especially across southern Kentucky. Instability is virtually not existent so not expecting much in the way of thunder. However, with the good moisture fetch off the SW Atlantic, training of rain showers looks increasingly likely which could lay down around an inch of rain in some spots by Saturday evening. The clouds and precipitation will keep temperatures down on Saturday with highs only warming into the upper 50s. .Long Term (Saturday Night through Thursday)... Issued at 300 AM EDT Fri May 3 2013 The well advertised cutoff upper level low will be over Arkansas at the beginning of the long term. This low will slowly swing across the southeastern CONUS and into northern GA by Monday morning. It will then work its way up the Atlantic coast through mid week. The fetch of moisture off the Atlantic will continue to wrap around the northern side of the low as it slides south of the forecast area through the end of the weekend. Moderate rain will continue across much of the area Saturday night through Sunday. Through this time period an rainfall totals look to range from half an inch across portions of the Bluegrass and southern Indiana to an inch south of the Bluegrass Parkway. Some minor flooding will be possible on area rivers with this rain. For more information refer to the hydrology discussion below. Rain chances will continue off and on through the first half of the work week. However, these will become more diurnal in nature as the low moves up the coast. A few thunderstorms will be possible with this activity, especially if the sun is able to break out at all. Thursday finally looks to be dry under ridging aloft. Temperatures will remain on the cool side Sunday with highs only in the lower 60s. However we will see a warming trend through the week. By Thursday high temperatures should be back into the upper 70s with lows in the mid to upper 50s. && .Aviation (12Z TAF Issuance)... Issued at 643 AM EDT Fri May 3 2013 Nearly stationary frontal boundary out near the MS river will remain out to our west throughout the day. VFR conditions are expected at all the terminals today with southeast winds picking up during the mid-morning hours. The pressure gradient is expected to increase as a deep upper low continues to strengthen over the Plains. Southeast winds of 10-15 mph with gusts up to 20 mph will be possible later this afternoon. A few waves of low pressure will move up along the frontal boundary producing a few rounds of showers later today. The vast majority of this activity will stay west of KBWG and KSDF this afternoon. Coverage still looks rather sparse enough to preclude mention in this TAF forecast at the moment. && .Hydrology... Issued at 300 PM EDT Thu May 2 2013 An upper air disturbance is forecast to move across the region this weekend. This will result in moderate to heavy rainfall over southern Kentucky. Between Friday afternoon and Sunday morning between one and inch inches could fall with the heaviest amounts near Bowling Green. This area recently had minor flooding and this new rain could result in a new round of flooding in the middle of the Green River Basin. Residents with livestock or equipment in flood prone areas should watch water levels closely this weekend. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...NONE. KY...NONE. $$ Updates..........MJ/RJS Short Term.......MJ Long Term........EER Aviation.........MJ Hydrology........CMC
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
700 PM EDT FRI MAY 3 2013 .SYNOPSIS... ISSUED AT 329 PM EDT FRI MAY 3 2013 UNSEASONABLY WARM TEMPERATURES WILL PERSIST THROUGH THE WEEKEND INTO EARLY NEXT WORK WEEK. EAST WINDS WILL KEEP TEMPERATURES WARM ALL THE WAY TO THE LAKE SHORE. THE NEXT GOOD CHANCES FOR RAIN DO NOT ARRIVE UNTIL WEDNESDAY NIGHT INTO THURSDAY. && .UPDATE... ISSUED AT 522 PM EDT FRI MAY 3 2013 I UPDATED THE GRIDS TO BETTER MATCH THE TEMP/DEW POINT GRADIENT NEAR US-31 OVER THE NEXT FEW HOURS. I ALSO USING A COMBINATION OF THE HRRR 19Z AND RAP MODEL UPDATED THE POP/WEATHER GRIDS TO SHOW THE SHOWERS LIFTING OUT TO THE NORTHWEST OVER THE NEXT FEW HOURS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 329 PM EDT FRI MAY 3 2013 CONVECTION HAS RECENTLY DEVELOPED ALONG THE INVERTED TROUGH/LAKE BREEZE BOUNDARY IN A REGION OF BETTER INSTABILITY CENTERED MAINLY SOUTH OF MUSKEGON. EXPECT A RAPID DECREASE IN ACTIVITY AGAIN THIS EVENING WITH A LOSS OF INSOLATION. AFTER THIS EVENING...DRY CONDITIONS WITH EAST WINDS WILL PERSIST THROUGH THE WEEKEND. THIS IS A WARM AND DRY PATTERN SO WENT ABOVE GUIDANCE TEMPERATURES...ESPECIALLY ALONG THE LAKESHORE WHICH CAN WARM SIGNIFICANTLY WITH THIS TYPE OF PATTERN WHERE SLIGHT DOWNSLOPING COMES INTO PLAY. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 342 PM EDT FRI MAY 3 2013 HAVE A DRY FORECAST FROM MONDAY THROUGH WEDNESDAY NIGHT AS THE LOW OVER THE SOUTHEAST U.S. AIDES IN KEEPING A RIDGE OVER THE GREAT LAKES. DRY AND WARM WEATHER IS FORECAST TO CONTINUE WITH HIGHS NEAR 70 OR INTO THE LOWER 70S EACH DAY NEXT WEEK. THE NEXT CHANCE FOR PRECIPITATION COMES OUT ON THURSDAY WHEN AN UPPER SHORTWAVE TROUGH IS PROGD TO SLIP THROUGH THE AREA. GIVEN UPPER LOWS SITUATED OVER THE LOWER 48 AND THE SHORTWAVE IS ON THE SOUTHERN EDGE OF THE WESTERLIES...CONFIDENCE IS LOWER IN ITS PLACEMENT AT DAY 6 IN THE FORECAST. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 700 PM EDT FRI MAY 3 2013 VFR CIGS WILL PREVAIL THROUGH SATURDAY. AS THE SYSTEM MOVES SOUTH OF MICHIGAN TONIGHT THROUGH SATURDAY THE IMPACT FOR SOUTHWEST MICHIGAN IS DEEP SOUTHEAST WINDS AND CEILING WELL ABOVE 10000 FT AGL. THE SHOWERS NEAR THE LAKE SHORE LATE THIS AFTERNOON HAVE ALREADY MOVED OUT OVER THE LAKE TO THE NORTHWEST OF MUSKEGON AND ARE NOT EXPECTED TO COME BACK. && .MARINE... ISSUED AT 329 PM EDT FRI MAY 3 2013 NO CHANGES TO THE FORECAST PLANNED AT THIS TIME. AFTER WINDS AND WAVES SUBSIDE THIS EVENING...GENERALLY LIGHT OFFSHORE WINDS WILL PRECLUDE THE NEED FOR HEADLINES. && .FIRE WEATHER... ISSUED AT 329 PM EDT FRI MAY 3 2013 WITH EASTERLY WINDS OVER THE WEEKEND...WE ARE IN A FAVORABLE SETUP FOR WARM AND DRY CONDITIONS. THE LATEST PLANNING FORECAST ISSUANCE BRINGS SOME AREAS CLOSER TO RED FLAG WARNING CRITERIA. TEMPERATURE AND HUMIDITY THRESHOLDS WILL BE SOMETHING TO CLOSELY WATCH OVER THE NEXT COUPLE DAYS. HOWEVER...WIND SPEEDS SHOULD ALSO BE DECREASING FROM SATURDAY TO SUNDAY. && .HYDROLOGY... ISSUED AT 329 PM EDT FRI MAY 3 2013 NO CONCERNS DUE TO LITTLE OR NO EXPECTED PRECIPITATION OVER THE NEXT SEVERAL DAYS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...WDM SYNOPSIS...TJT SHORT TERM...TJT LONG TERM...DUKE AVIATION...WDM FIRE WEATHER...TJT HYDROLOGY...TJT MARINE...TJT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
524 PM EDT FRI MAY 3 2013 .SYNOPSIS... ISSUED AT 329 PM EDT FRI MAY 3 2013 UNSEASONABLY WARM TEMPERATURES WILL PERSIST THROUGH THE WEEKEND INTO EARLY NEXT WORK WEEK. EAST WINDS WILL KEEP TEMPERATURES WARM ALL THE WAY TO THE LAKE SHORE. THE NEXT GOOD CHANCES FOR RAIN DO NOT ARRIVE UNTIL WEDNESDAY NIGHT INTO THURSDAY. && .UPDATE... ISSUED AT 522 PM EDT FRI MAY 3 2013 I UPDATED THE GRIDS TO BETTER MATCH THE TEMP/DEW POINT GRADIENT NEAR US-31 OVER THE NEXT FEW HOURS. I ALSO USING A COMBINATION OF THE HRRR 19Z AND RAP MODEL UPDATED THE POP/WEATHER GRIDS TO SHOW THE SHOWERS LIFTING OUT TO THE NORTHWEST OVER THE NEXT FEW HOURS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 329 PM EDT FRI MAY 3 2013 CONVECTION HAS RECENTLY DEVELOPED ALONG THE INVERTED TROUGH/LAKE BREEZE BOUNDARY IN A REGION OF BETTER INSTABILITY CENTERED MAINLY SOUTH OF MUSKEGON. EXPECT A RAPID DECREASE IN ACTIVITY AGAIN THIS EVENING WITH A LOSS OF INSOLATION. AFTER THIS EVENING...DRY CONDITIONS WITH EAST WINDS WILL PERSIST THROUGH THE WEEKEND. THIS IS A WARM AND DRY PATTERN SO WENT ABOVE GUIDANCE TEMPERATURES...ESPECIALLY ALONG THE LAKESHORE WHICH CAN WARM SIGNIFICANTLY WITH THIS TYPE OF PATTERN WHERE SLIGHT DOWNSLOPING COMES INTO PLAY. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 342 PM EDT FRI MAY 3 2013 HAVE A DRY FORECAST FROM MONDAY THROUGH WEDNESDAY NIGHT AS THE LOW OVER THE SOUTHEAST U.S. AIDES IN KEEPING A RIDGE OVER THE GREAT LAKES. DRY AND WARM WEATHER IS FORECAST TO CONTINUE WITH HIGHS NEAR 70 OR INTO THE LOWER 70S EACH DAY NEXT WEEK. THE NEXT CHANCE FOR PRECIPITATION COMES OUT ON THURSDAY WHEN AN UPPER SHORTWAVE TROUGH IS PROGD TO SLIP THROUGH THE AREA. GIVEN UPPER LOWS SITUATED OVER THE LOWER 48 AND THE SHORTWAVE IS ON THE SOUTHERN EDGE OF THE WESTERLIES...CONFIDENCE IS LOWER IN ITS PLACEMENT AT DAY 6 IN THE FORECAST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 245 PM EDT FRI MAY 3 2013 EXPECTING VFR CONDITIONS THE NEXT 24 HOURS...AS SOUTHWEST LOWER MICHIGAN REMAINS ON THE PERIPHERY OF AN UPPER LOW TO OUR SOUTHWEST. CEILINGS BETWEEN 5000-8000FT CAN BE EXPECTED THIS AFTERNOON AND EVENING AS CUMULUS CLOUDS BUBBLE UP IN THE HEAT OF THE DAY. HAVE INCLUDED VCSH AT KMKG...KGRR AND KAZO FROM 21Z THROUGH 04Z. THE HIGH BASED CUMULUS SHOULD DISSIPATE TOWARDS MIDNIGHT...WITH CLOUDS AT OR ABOVE 10000FT TONIGHT INTO SATURDAY MORNING. WIND DIRECTION WILL BE SOUTHEAST FOR THE MOST PART OUTSIDE OF A LAKE BREEZE THAT PUSHES SLIGHTLY INLAND THIS AFTERNOON. && .MARINE... ISSUED AT 329 PM EDT FRI MAY 3 2013 NO CHANGES TO THE FORECAST PLANNED AT THIS TIME. AFTER WINDS AND WAVES SUBSIDE THIS EVENING...GENERALLY LIGHT OFFSHORE WINDS WILL PRECLUDE THE NEED FOR HEADLINES. && .FIRE WEATHER... ISSUED AT 329 PM EDT FRI MAY 3 2013 WITH EASTERLY WINDS OVER THE WEEKEND...WE ARE IN A FAVORABLE SETUP FOR WARM AND DRY CONDITIONS. THE LATEST PLANNING FORECAST ISSUANCE BRINGS SOME AREAS CLOSER TO RED FLAG WARNING CRITERIA. TEMPERATURE AND HUMIDITY THRESHOLDS WILL BE SOMETHING TO CLOSELY WATCH OVER THE NEXT COUPLE DAYS. HOWEVER...WIND SPEEDS SHOULD ALSO BE DECREASING FROM SATURDAY TO SUNDAY. && .HYDROLOGY... ISSUED AT 329 PM EDT FRI MAY 3 2013 NO CONCERNS DUE TO LITTLE OR NO EXPECTED PRECIPITATION OVER THE NEXT SEVERAL DAYS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...WDM SYNOPSIS...TJT SHORT TERM...TJT LONG TERM...DUKE AVIATION...DUKE FIRE WEATHER...TJT HYDROLOGY...TJT MARINE...TJT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
418 PM EDT FRI MAY 3 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 418 PM EDT FRI MAY 3 2013 UPPER TROUGH CONTINUES TO SPLIT APART NEXT 24 HRS WITH UPPER LOW FOCUSING OVER CNTRL MISSISSIPPI RIVER VALLEY. REGIONAL RADAR SHOWS SWATH OF MAINLY RAIN FROM ILLINOIS INTO WISCONISN AND INTO WESTERN UPR MICHIGAN AND INTO MINNESOTA ARROWHEAD. THIS PRECIP IS SUPPORTED BY PERSISTENT H85-H7 FRONTOGENESIS AND RIGHT ENTRANCE REGION FROM UPPER JET OVER ONTARIO. BOTH FEATURES ARE FORECAST TO DIMINISH INTO SATURDAY AS UPPER LOW TO THE SOUTH BECOMES DOMINANT UPPER LEVEL FEATURE. ANALYSIS FROM RUC AND NAM INDICATING WARM LAYER IS WELL ABOVE 0C SUGGESTS PTYPE OVER WESTERN UPR MICHIGAN SHOULD BE RAIN BUT REPORTS FROM GOGEBIC INTO SOUTHERN HOUGHTON COUNTY SHOW IT IS NOT WITH LGT SNOW OCCURRING. THESE AREAS LINE UP WELL WITH SUB ZERO 950-900MB TEMPS SO KEPT MENTION OF SLEET/SNOW OVER FAR WESTERN UPR MICHIGAN THROUGH EARLY MORNING HOURS BEFORE SHALLOWER COLD TEMPS WARM ABOVE 0C. OTHERWISE...RAIN WILL BE DOMINANT PTYPE ACROSS REST OF CWA...MORE SCATTERED IN THE EASTERN HALF OF CWA. KEPT A MENTION OF FZRA OVER INLAND WESTERN THIRD OF CWA. SINCE MAJORITY OF PRECIP WILL OCCUR OVER WESTERN CWA AND SINCE THERE IS GOING TO BE CONTINUING FZRA/SLEET/SNOW...CHANGING TO RAIN/FREEZING RAIN...OPTED TO KEEP WINTER WEATHER ADVY OUT FOR GOGEBIC AND ONTONAGON COUNTIES THROUGH 12Z SATURDAY. COULD SEE SIMILAR PYTPE THIS EVENING FARTHER EAST ACROSS KEWEENAW...BUT BASED ON UPSTREAM RADAR TRENDS AND BLEND OF SHORT TERM MODELS...THINK THESE AREAS WILL MISS OUT ON HEAVIER QPF AND BETTER CHANCE OF SLEET/ICE ACCUMS. IMPROVING WEATHER ON SATURDAY...HOPEFULLY. LINGERING DIVERGENCE ALOFT MAY STILL BRING SOME LGT RAIN OVER WEST AND NORTHWEST CWA. SHOULD STAY DRY OVER THE EAST HALF. SIMILAR TO LAST COUPLE DAYS SHOULD BE A WIDE TEMPERATURE RANGE FROM WEST TO EAST. BASED ON FCST H85 TEMPS AND CLEARER SKIES EXPECTED...THINKING EASTERN INTERIOR CWA MAY REACH MID 60S TO LOWER 70S. COOLER NORTH FLOW KEEPS WEST AND CNTRL COOLER...BUT STILL A BIT WARMER THAN RECENT TEMPERATURES. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 418 PM EDT FRI MAY 3 2013 NAM SHOWS A CLOSED 500 MB LOW OVER NORTHERN CA AND ANOTHER OVER NORTHERN ARKANSAS WITH A 500 MB RIDGE OVER THE LOWER GREAT LAKES. THE 500 MB PATTERN OVER THE EAST HALF OF THE U.S. IS AN OMEGA BLOCK 00Z SUN AND DOES NOT MOVE MUCH ON SUNDAY EXCEPT TO TRY TO FORM A REX BLOCK WITH THE LOW MOVING SLOWLY EAST UNDERNEATH THE RIDGE. THE REX BLOCK THEN GETS ESTABLISHED ON MON. THIS FORECAST PERIOD FEATURES DEEPER MOISTURE OVER THE WEST HALF OF THE CWA GRADUALLY DECREASING. WILL KEEP SLIGHT CHANCE POPS OVER THE FAR WESTERN CWA SAT NIGHT WITH THIS MOVING FURTHER WEST WITH TIME ON SUN. PCPN SHOULD BE ALL RAIN BY THAT TIME. TEMPERATURES CONTINUE THE SLOW WARMING TREND WITH TIME AND DRY WEATHER COMES IN FOR SUN INTO MON. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR TEMPERATURES EXCEPT DID LOWER LOWS A BIT WITH THE COLDER MOS GUIDANCE FOR SAT NIGHT AND SUN NIGHT. IN THE EXTENDED...ECMWF AND GFS SHOW A CLOSED 500 MB LOW OVER THE SOUTHEAST U.S. 12Z TUE. THINGS GET INTERESTING OVER THE NORTHERN PLAINS. 12Z TUE...ECMWF HAS A CLOSED 500 MB LOW NEAR SISSETON SD AND THE GFS HAS A 500 MB RIDGE THERE INSTEAD. THIS DIFFERENCE CARRIES INTO 12Z WED WITH THE ECMWF CONTINUING ITS SOLUTION OF A TROUGH IN THE UPPER MISSISSIPPI VALLEY WITH THE 06Z GFS HAVING A CLOSED 500 MB LOW OVER MISSOURI WHILE THE 00Z GFS STILL MAINTAINING A RIDGE OVER THE CORNBELT. THE ECMWF TAKES THE TROUGH INTO THE UPPER GREAT LAKES 12Z THU WITH THE GFS MAINTAINING A FLAT 500 MB RIDGE OVER THE AREA. THE 500 MB RIDGE GETS FLATTENED BY 12Z FRI WITH A BROAD 500 MB TROUGH AND THE WESTERLIES GETTING PUSHED SOUTH INTO THE AREA. CONFIDENCE REMAINS LOW WITH THIS EXTENDED FORECAST DUE TO THE 2 VERY DIFFERENT MODEL SOLUTIONS. LOOKS DRY THROUGH TUE NIGHT BEFORE A COLD FRONT HEADS SOUTH OUT OF CANADA AND BRINGS WITH IT A SLIGHT CHANCE TO LOW CHANCE FOR PCPN WED INTO FRI. TEMPERATURES CONTINUE TO SLOWLY WARM AND GO TO NEAR NORMAL BY THE END OF THE PERIOD. THE COLD FRONT MOVES THROUGH WED NIGHT AND SLOWLY PUSHES SOUTH OF THE AREA THEN FOR THU INTO FRI. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 149 PM EDT FRI MAY 3 2013 CIGS REMAIN FAIRLY SIMILAR THROUGH THE TAF PERIOD AS LOW LEVEL MOISTURE IS ABUNDANT. BASED ON UPSTREAM RADAR AND OBSERVATION TRENDS...STILL DECENT CHANCE OF SEEING ADDITIONAL PRECIP AT IWD BY THIS EVENING...PROBABLY IN THE FORM OF FZRA/FZDZ. BETTER CHANCE FOR PRECIP AT SAW...SCT SHOWERS...WILL BE AROUND SUNSET. THERE WILL BE BETTER CHANCE OF DZ/FZDZ BY THIS EVENING AND THROUGH THE NIGHT AT CMX. HAVE WENT WITH A RETURN TO IFR VSBY AT SAW LATER THIS EVENING THROUGH DAYBREAK SATURDAY GIVEN PERSISTENT UPSLOPE FLOW AND SUBSIDENCE INVERSION SETTING UP LATER TONIGHT. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 418 PM EDT FRI MAY 3 2013 NO GALES SEEN DURING THIS FORECAST PERIOD. THE STRONGEST WINDS IN THE PERIOD ARE THIS AFTERNOON WITH NORTHEAST WINDS BELOW 25 KNOTS. A HIGH PRESSURE RIDGE SETTLES IN AND KEEPS STRONG SYSTEMS AWAY FROM THE AREA. && .HYDROLOGY... ISSUED AT 418 PM EDT FRI MAY 3 2013 STURGEON RIVER AT ALSTON AND CHASSELL...THE MICHIGAMME RIVER AROUND WITCH LAKE...AND THE PAINT RIVER NEAR CRYSTAL FALLS WILL REMAIN CONCERNS INTO AT LEAST EARLY NEXT WEEK...BUT OTHERWISE RIVER LEVELS CONTINUE TO COME DOWN. ACTUALLY...MICHIGAMME MAY REMAIN A CONCERN THROUGH MOST OF NEXT WEEK. DECENT AMOUNT OF WATER EQUIVALENT HAS OCCURRED LAST TWO DAYS OVER WESTERN CWA...VCNTY OF IRONWOOD TO ONTONAGON...OVER 2 INCHES OVER FAR WESTERN GOGEBIC COUNTY. WILL HAVE TO ASSESS WHAT AFFECT THE PRECIP WILL HAVE WHEN COMBINED WITH FURTHER MELTING OF ANY SUSTAINED SNOWPACK WHEN TEMPS WARM INTO THE 60-70S SUN INTO NEXT WEEK. SNOW WATER EQUIVALENT OF 8.8 INCHES IN PAINESDALE ON THURSDAY WITH 24 INCHES OF SNOW DEPTH...SO THE OTTER RIVER STILL HAS PLENTY OF SNOW IN THE HEADWATERS WHICH MAY CAUSE ADDITIONAL PROBELMS AT CLLM4 IN THE COMING DAYS. FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND ADVISORIES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY UNTIL 8 AM EDT /7 AM CDT/ SATURDAY FOR MIZ002-009. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLA LONG TERM...07 AVIATION...JLA MARINE...07 HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
246 PM EDT FRI MAY 3 2013 .SYNOPSIS... ISSUED AT 340 AM EDT FRI MAY 3 2013 IT WILL BE MILD TODAY WITH SCATTERED AFTERNOON SHOWERS AND A FEW THUNDERSTORMS MAINLY WEST OF A LINE FROM KALAMAZOO TO GRAND RAPIDS AND BIG RAPIDS. DRY AND MILD WEATHER IS ANTICIPATED THROUGH THE WEEKEND AND FOR MOST OF NEXT WEEK. && .UPDATE... ISSUED AT 932 AM EDT FRI MAY 3 2013 UPDATED FORECAST TO ACCOUNT FOR RAIN SHOWERS CURRENTLY OVER FAR SW CWA. HAVE GENERALLY RAISED POPS NEAR THE LAKESHORE INTO THE AFTERNOON. LATEST HRRR GUIDANCE SUGGESTS THAT AREA OF PRECIPITATION OVER CENTRAL IN WILL MOVE NORTH...REACHING OUR SOUTHERN CWA BY THIS EVENING. WILL MONITOR THIS AND MAY BE RAISING POPS SOUTH OF I-96 LATER TODAY IF THESE TRENDS CONTINUE. && .SHORT TERM...(TODAY THROUGH SUNDAY AFTERNOON) ISSUED AT 340 AM EDT FRI MAY 3 2013 OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE PROBABILITIES FOR SCATTERED SHOWERS/TSTORMS TODAY. AS WAS THE CASE YESTERDAY AFTERNOON WE EXPECT SFC CONVERGENCE FROM AN INVERTED SFC TROF AND THE LAKE BREEZE TO TRIGGER DEVELOPMENT OF SHOWERS AND A FEW STORMS THIS AFTERNOON... WITH THE RELATIVELY BEST CHC FOR THOSE WEST OF US-131 AS SUGGESTED BY LATEST 00Z 4KM WRF-NMM SIM Z GUIDANCE. MAX TEMPS WILL REACH THE LOW TO MID 70S EXCEPT SIGNIFICANTLY COOLER RIGHT ALONG THE LAKE MI SHORELINE. DRY AND SEASONABLY MILD WX IS THEN EXPECTED TONIGHT THROUGH SUNDAY AS THE UPPER RIDGE AXIS TAKES HOLD AND UPPER LOW DRIFTS FURTHER SE INTO THE SOUTHEASTERN UNITED STATES. MAX TEMPS THIS WEEKEND SHOULD AGAIN REACH THE LOW TO MID 70S. THE EASTERLY WINDS WILL LIKELY NOT BE STRONG ENOUGH TO PRECLUDE LAKE BREEZE DEVELOPMENT SATURDAY AND SUNDAY... SO LOCATIONS RIGHT ALONG LAKE MI SHOULD AGAIN BE COOLER. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 340 AM EDT FRI MAY 3 2013 LOOKS LIKE A QUIET WEATHER PATTERN IN THE EXTENDED AS THE UPPER LOW TRACKS WELL SOUTH OF THE GREAT LAKES AND DRY EAST FLOW DOMINATES. ADDED SLIGHT CHANCE POPS FOR THURSDAY AS WEAKER...NORTHERN CUT OFF LOW FINALLY MOVES EAST AND OVER LOWER MICHIGAN. THIS SHOULD BE MOISTURE STARVED SINCE IT HAS LITTLE OR NO GULF MOISTURE TO WORK WITH. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 245 PM EDT FRI MAY 3 2013 EXPECTING VFR CONDITIONS THE NEXT 24 HOURS...AS SOUTHWEST LOWER MICHIGAN REMAINS ON THE PERIPHERY OF AN UPPER LOW TO OUR SOUTHWEST. CEILINGS BETWEEN 5000-8000FT CAN BE EXPECTED THIS AFTERNOON AND EVENING AS CUMULUS CLOUDS BUBBLE UP IN THE HEAT OF THE DAY. HAVE INCLUDED VCSH AT KMKG...KGRR AND KAZO FROM 21Z THROUGH 04Z. THE HIGH BASED CUMULUS SHOULD DISSIPATE TOWARDS MIDNIGHT...WITH CLOUDS AT OR ABOVE 10000FT TONIGHT INTO SATURDAY MORNING. WIND DIRECTION WILL BE SOUTHEAST FOR THE MOST PART OUTSIDE OF A LAKE BREEZE THAT PUSHES SLIGHTLY INLAND THIS AFTERNOON. && .MARINE... ISSUED AT 340 AM EDT FRI MAY 3 2013 WE WILL ALLOW THE SCA TO EXPIRE EARLY THIS MORNING. WAVE HEIGHTS OF 2 TO 4 FEET ARE ANTICIPATED TODAY BUT WAVES AND WINDS WILL STAY BELOW SCA CRITERIA. MINIMAL WAVE ACTION IS ANTICIPATED THIS WEEKEND WITH OFFSHORE WINDS. && .FIRE WEATHER... ISSUED AT 340 AM EDT FRI MAY 3 2013 A FEW SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY. AFTER TODAY DRY AND MILD WEATHER IS EXPECTED THIS WEEKEND THROUGH MOST OF NEXT WEEK KEEPING FUEL MOISTURE RATHER LOW. && .HYDROLOGY... ISSUED AT 340 AM EDT FRI MAY 3 2013 ANY PRECIPITATION TODAY FROM SCATTERED SHOWERS AND A FEW STORMS WILL BE QUITE LIGHT. DRY WEATHER IS EXPECTED THIS WEEKEND THROUGH MOST OF NEXT WEEK. THEREFORE THERE ARE NO SIGNIFICANT HYDRO CONCERNS AT THIS TIME THAT WOULD AFFECT MAINSTEM RIVERS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...TJT SYNOPSIS...LAURENS SHORT TERM...LAURENS LONG TERM...OSTUNO AVIATION...DUKE FIRE WEATHER...LAURENS HYDROLOGY...LAURENS MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
931 AM EDT FRI MAY 3 2013 .SYNOPSIS... ISSUED AT 340 AM EDT FRI MAY 3 2013 IT WILL BE MILD TODAY WITH SCATTERED AFTERNOON SHOWERS AND A FEW THUNDERSTORMS MAINLY WEST OF A LINE FROM KALAMAZOO TO GRAND RAPIDS AND BIG RAPIDS. DRY AND MILD WEATHER IS ANTICIPATED THROUGH THE WEEKEND AND FOR MOST OF NEXT WEEK. && .UPDATE... ISSUED AT 932 AM EDT FRI MAY 3 2013 UPDATED FORECAST TO ACCOUNT FOR RAIN SHOWERS CURRENTLY OVER FAR SW CWA. HAVE GENERALLY RAISED POPS NEAR THE LAKESHORE INTO THE AFTERNOON. LATEST HRRR GUIDANCE SUGGESTS THAT AREA OF PRECIPITATION OVER CENTRAL IN WILL MOVE NORTH...REACHING OUR SOUTHERN CWA BY THIS EVENING. WILL MONITOR THIS AND MAY BE RAISING POPS SOUTH OF I-96 LATER TODAY IF THESE TRENDS CONTINUE. && .SHORT TERM...(TODAY THROUGH SUNDAY AFTERNOON) ISSUED AT 340 AM EDT FRI MAY 3 2013 OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE PROBABILITIES FOR SCATTERED SHOWERS/TSTORMS TODAY. AS WAS THE CASE YESTERDAY AFTERNOON WE EXPECT SFC CONVERGENCE FROM AN INVERTED SFC TROF AND THE LAKE BREEZE TO TRIGGER DEVELOPMENT OF SHOWERS AND A FEW STORMS THIS AFTERNOON... WITH THE RELATIVELY BEST CHC FOR THOSE WEST OF US-131 AS SUGGESTED BY LATEST 00Z 4KM WRF-NMM SIM Z GUIDANCE. MAX TEMPS WILL REACH THE LOW TO MID 70S EXCEPT SIGNIFICANTLY COOLER RIGHT ALONG THE LAKE MI SHORELINE. DRY AND SEASONABLY MILD WX IS THEN EXPECTED TONIGHT THROUGH SUNDAY AS THE UPPER RIDGE AXIS TAKES HOLD AND UPPER LOW DRIFTS FURTHER SE INTO THE SOUTHEASTERN UNITED STATES. MAX TEMPS THIS WEEKEND SHOULD AGAIN REACH THE LOW TO MID 70S. THE EASTERLY WINDS WILL LIKELY NOT BE STRONG ENOUGH TO PRECLUDE LAKE BREEZE DEVELOPMENT SATURDAY AND SUNDAY... SO LOCATIONS RIGHT ALONG LAKE MI SHOULD AGAIN BE COOLER. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 340 AM EDT FRI MAY 3 2013 LOOKS LIKE A QUIET WEATHER PATTERN IN THE EXTENDED AS THE UPPER LOW TRACKS WELL SOUTH OF THE GREAT LAKES AND DRY EAST FLOW DOMINATES. ADDED SLIGHT CHANCE POPS FOR THURSDAY AS WEAKER...NORTHERN CUT OFF LOW FINALLY MOVES EAST AND OVER LOWER MICHIGAN. THIS SHOULD BE MOISTURE STARVED SINCE IT HAS LITTLE OR NO GULF MOISTURE TO WORK WITH. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 751 AM EDT FRI MAY 3 2013 VFR SHOULD PREVAIL MOST OF THE DAY BUT AREAS OF MVFR IN SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND INTO THE EVENING. LEFT THIS OUT OF THE FORECAST SINCE THE COVERAGE IS EXPECTED TO BE LOW...BUT PROBABLY GREATER THAN YESTERDAY. WINDS WILL BE AOB 10 KNOTS FROM THE EAST OR SOUTHEAST. && .MARINE... ISSUED AT 340 AM EDT FRI MAY 3 2013 WE WILL ALLOW THE SCA TO EXPIRE EARLY THIS MORNING. WAVE HEIGHTS OF 2 TO 4 FEET ARE ANTICIPATED TODAY BUT WAVES AND WINDS WILL STAY BELOW SCA CRITERIA. MINIMAL WAVE ACTION IS ANTICIPATED THIS WEEKEND WITH OFFSHORE WINDS. && .FIRE WEATHER... ISSUED AT 340 AM EDT FRI MAY 3 2013 A FEW SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY. AFTER TODAY DRY AND MILD WEATHER IS EXPECTED THIS WEEKEND THROUGH MOST OF NEXT WEEK KEEPING FUEL MOISTURE RATHER LOW. && .HYDROLOGY... ISSUED AT 340 AM EDT FRI MAY 3 2013 ANY PRECIPITATION TODAY FROM SCATTERED SHOWERS AND A FEW STORMS WILL BE QUITE LIGHT. DRY WEATHER IS EXPECTED THIS WEEKEND THROUGH MOST OF NEXT WEEK. THEREFORE THERE ARE NO SIGNIFICANT HYDRO CONCERNS AT THIS TIME THAT WOULD AFFECT MAINSTEM RIVERS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...TJT SYNOPSIS...LAURENS SHORT TERM...LAURENS LONG TERM...OSTUNO AVIATION...OSTUNO FIRE WEATHER...LAURENS HYDROLOGY...LAURENS MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
730 PM CDT SAT MAY 4 2013 ...UPDATED FOR 00Z AVIATION DISCUSSION... .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 341 PM CDT SAT MAY 4 2013 WARMER WEATHER WILL GRADUALLY MOVE IN ACROSS THE REGION OVER THE NEXT FEW DAYS AND CONDITIONS BEGIN TO DRY OUT. BY THE MIDDLE OF THE WEEK A SERIES OF UPPER LEVEL DISTURBANCES WILL BRING RETURNED CHANCES FOR SHOWERS AND THUNDERSTORMS...ALONG WITH COOLER TEMPERATURES. EARLY AFTERNOON NORTH AMERICAN WATER VAPOR IMAGERY TOGETHER WITH 500MB HEIGHTS AND WINDS SHOWED THE CUTOFF LOW SPINNING OVER THE OZARK MOUNTAINS...WITH A RIDGE LOCATED ALONG EACH COAST. AT THE SURFACE A LOOSE PRESSURE GRADIENT WAS DRAPED ACROSS THE UPPER MIDWEST BETWEEN A 1028 HIGH IN NORTH DAKOTA...AND A 1013 LOW IN SOUTHERN MISSOURI WITH NORTHERLY WINDS OVER MINNESOTA AND WISCONSIN. THE EXPANSIVE CLOUD SHIELD FROM THE AFOREMENTIONED UPPER LEVEL LOW WAS BEGINNING TO SHOW SOME HOLES IN WISCONSIN...AND THIS ALLOWED TEMPERATURES TO CLIMB INTO THE MID 70S WHERE THERE WAS NO SNOWPACK. HOWEVER...FARTHER WEST TEMPERATURES WERE ONLY IN THE 40S WHERE THE DEEP SNOWPACK LINGERED FROM THE PREVIOUS WINTER STORM. FARTHER WEST STILL IN NEAR THE SD/MN BORDER TEMPERATURES WERE ONLY IN THE UPPER 30S ALONG WITH THICKER CLOUDS AND LIGHT DRIZZLE ASSOCIATED WITH THE DEFORMATION ZONE FROM THE DECAYING CYCLONE TO THE SOUTH. TONIGHT FORECAST MODELS SHOW THE PRESSURE GRADIENT RELAXING...RESULTING IN DECREASING WINDS. AS THE CLEARING TREND PROGRESSES WESTWARD OVERNIGHT AREAS OF FOG ARE EXPECTED TO DEVELOP ALONG THE MN/WI BORDER...WITH THE HIGHEST POTENTIAL FOR DENSE FOG ALONG AND EAST OF A LINE FROM ALBERT LEA UP THROUGH RED WING AND RICE LAKE WI. FORECAST SOUNDINGS SHOW A DEEP INVERSION WITH LOW LEVEL MOISTURE...BUT FEEL THE WINDS ARE OVERDONE...SO THE FOG POTENTIAL IS HIGHER THAN INDICATED. MEMBER 2 OF THE HOPWRF HAS A BETTER HANDLE OF THE CLEARING TREND...AND SHOWS FOG DEVELOPMENT IN THIS REGION AROUND 08Z. THE 16Z RUN OF THE HRRR SHOWS A SIMILAR TREND. THEREFORE HAVE ISSUED A DENSE FOG ADVISORY OVERNIGHT. HIGH TEMPERATURES ON SUNDAY WILL DEPEND ON HOW QUICKLY WE CAN MIX OUT THE FOG. THIS WILL BE DIFFICULT TO DO WITH LIGHT WINDS AND WEAK MECHANICAL MIXING...SO WILL HAVE TO DEPEND ON THE EARLY MAY SUN. TEMPERATURES ACROSS THE WEST WILL BE 15 TO 20 DEGREES COOLER THAN SNOW FREE AREAS OF WISCONSIN DUE TO CLOUD COVER. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 341 PM CDT SAT MAY 4 2013 SUNDAY NIGHT WILL HAVE ANOTHER FAVORABLE SETUP FOR FOG DEVELOPMENT. ON MONDAY SURFACE TEMPERATURES WILL REBOUND TO NEAR 70 DEGREES...WITH WARMER TEMPS ON TUESDAY AS SOUTHERLY FLOW INCREASES AHEAD OF THE NEXT WEAK UPPER LEVEL WAVE. USED A MIX DOWN TOOL TO FORECAST HIGH TEMPERATURES...AND INCREASED THEM A FEW DEGREES ABOVE THE PREVIOUS FORECAST...ESPECIALLY IN FAR WESTERN MINNESOTA. THIS WAVE IS FORECAST TO BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS WEDNESDAY. THE SEVERE WEATHER THREAT IS VERY LOW...WITH SMALL DEEP LAYER SHEAR AND ONLY 500J/KG OF MLCAPE. UNSETTLED WEATHER WILL CONTINUE THROUGH THE END OF THE WEEK. LOW POPS AND SLIGHTLY COOLER TEMPERATURES WILL BE FOCUSED ALONG A WARM FRONT THAT IS FORECAST TO STALL OUT ACROSS THE REGION...AS PERIODIC SHORTWAVES MOVING ACROSS THE UPPER MIDWEST. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY AFTERNOON) ISSUED AT 1230 PM CDT SAT MAY 4 2013 WELL ADVERTISED CUT OFF 50H LOW WILL CONTINUE TO SLOWLY TREK FROM ARKANSAS INTO ALABAMA BY SUN/18Z. EJECTION OF THIS FEATURE HAS PRETTY MUCH ELIMINATED MOST CHANCES FOR RAINFALL ACROSS ALL TAF SITES. QUITE A FEW LARGE AREAS OF CLEAR TO SCT SKY CONDITIONS NOTED OVER EAST CENTRAL MN AND MOST OF WI. IFR CIGS AT KAXN ...KSTC AND KRWF WILL TRANSITION BACK TO VFR CONDITIONS BY 03Z. MODELS ARE WAY TOO PESSIMISTIC ON MVFR CIGS THROUGH AT LEAST FIRST 6 TO 8 HOURS OF FORECAST...ALTHOUGH NAM GUIDANCE CLOSER TO ACTUAL CONDITIONS. WITH THAT SAID DECIDED BEST OPTION WAS TO REINTRODUCE LOW END MVFR CIGS AT MOST AIRPORTS AFT 09Z ASSOCIATED WITH FOG FORMATION IN LIEU OF LIGHTENING N WIND REGIME AND COPIOUS RESIDUAL MOISTURE LEVELS. IFR VSBY FOG SHOULD DEVELOP OVER MOST TAF SITES WITH WORST VSBYS...LIFR...ANTICIPATED AT KEAU AND KRNH...A REFLECTION OF RECENT HEAVY SNOWFALL EVENT. KU-RULE INDICATING FAIRLY QUICK DISINTEGRATION OF STRATOCU DECK BY 14Z MOST LOCALES. SHORT WINDOW OF SCT CONDITIONS FROM KSTC-KMSP EAST...AS COLD AIR ALOFT COMBINES WITH SFC HEATING INITIATING NEW VFR STRATO-CU DECK BY LATE MORNING. KU-RULE CONFIRMS THIS ASSUMPTION...AND BACKS UP SCT CONDITIONS THROUGH MOST OF THE DAYLIGHT HOURS AT KAXN AND KRWF. LIGHT NORTHERLY WINDS WILL CONTINUE THROUGH END OF PD. SHOULD EXPECT SCT CONDITIONS SUNDAY NIGHT...WITH VERY POSSIBLE IFR-LOW END FOG CONDITIONS DEVELOPING AGAIN LATE SUNDAY NIGHT. KMSP... ANTICIPATE WEAK NORTHERLY WIND COMPONENT THROUGH END OF PERIOD. HIGH LEVEL CIRRUS WILL GIVE WAY TO LOWERING MID AND THEN STRATO CU DECK BY 07Z. RADIATIONAL COOLING...SLACKENING WIND REGIME AND PLENTY OF RESIDUAL MOISTURE SHOULD EQUAL AT LEAST IFR VSBYS AND POSSIBLE SHORT PERIOD LIFR BETWEEN 09 AND 12Z. MVFR TO LOW END MVFR CIGS WILL FOLLOW SUIT WITH FOG INITIATION. STRATO-CU DECK SHOULD BREAK UP BY 14Z...AS NVA CONTINUES TO PLOW INTO REGION FROM WESTERN WI. STILL ENOUGH COLD AIR ALOFT TO INITIATED VFR STRATO CU RETURN BY LATE MORNING...WITH DISINTEGRATION ANTICIPATED BY 22Z TIME FRAME AND THEN CLEARING SKIES FOR MUCH OF SUNDAY NIGHT. ANOTHER GOOD CHANCE FOR MVFR FOG ANTICIPATED FOR LATE SUNDAY NIGHT. /OUTLOOK FOR KMSP/ MON...VFR CIGS. PERIOD OF MVFR CIGS 09Z-12Z. WINDS LIGHT/VARIABLE. TUE...VFR. WINDS LIGHT/VARIABLE...BECOMING SOUTH 3-5 KTS TUE NIGHT. WED...VFR. WIND SOUTH AT 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR MNZ078-085- 093. WI...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR WIZ015-016- 023>028. && $$ SHORT TERM...TRH LONG TERM...JRB AVIATION...AZ
AREA FORECAST DISCUSSION
NWS DULUTH MN
1243 PM CDT FRI MAY 3 2013 .AVIATION...18Z TAF ISSUANCE PRECIPITATION IN VARIOUS FORMS WILL CONTINUE ACROSS THE REGION THIS AFTERNOON...WEST OF A LINE FROM KINL THROUGH KDLH...THEN SPREAD EAST INTO KBRD AFT 00Z. MOST OF THE PRECIPITATION WILL BE SNOW AT FIRST...THEN CHANGE TO RAIN OR FREEZING RAIN...DEPENDING ON SFC TEMPS...WHICH WILL HOVER AROUND FREEZING. CIGS WILL BE MAINLY MVFR THROUGH 00Z THEN DROP TO IFR IN THE MAIN RAIN AREAS. && .PREV DISCUSSION... /ISSUED 1025 AM CDT FRI MAY 3 2013/ UPDATE... HAVE EXTENDED THE WINTER WEATHER ADVISORY FOR FREEZING RAIN OVER NORTHERN WISCONSIN /EXCEPT PRICE COUNTY/ THROUGH 1000 PM THIS EVENING...POSSIBLY NEEDING TO BE EXTENDED FURTHER. THE 12Z NAM/DLHWRF BOTH SHOW SFC TEMPS REMAIN BELOW FREEZING OVER THE ADVISORY AREA THROUGH AT LEAST MIDNIGHT. MEANWHILE...AN S-SE H85 FLOW WILL CONTINUE TO WARM MID LEVELS THROUGH THE DAY...DIMINISHING ANY LINGERING SNOW AND PROMOTING FREEZING RAIN THIS AFTERNOON/TONIGHT. HAVE INTRODUCED MENTION OF FREEZING RAIN TO MN ARROWHEAD ZONES THIS AFTERNOON AND EVENING WHERE H80-H85 LAYER TEMPS WARM A FEW DEGREES ABOVE 0 C...WHILE SFC READINGS REMAIN SUB-FREEZING. WE WILL CLOSELY MONITOR THIS AREA FOR ICE ACCUM POTENTIAL...AND AN ADVISORY MAY BE NEEDED THIS AFTERNOON/TONIGHT FOR LAKE COOK COUNTIES. PREV DISCUSSION... /ISSUED 408 AM CDT FRI MAY 3 2013/ .SHORT TERM...TODAY THROUGH SATURDAY. AT 4 AM...IT WAS FAIRLY QUIET ACROSS THE NORTHLAND. THERE WAS SOME LIGHT SNOW ACROSS NW WI...AND REPORTS JUST OUTSIDE OF THE CWA OF SOME LIGHT FREEZING DRIZZLE. TEMPERATURES RANGED FROM THE 20S IN NE MN TO AROUND 30 IN NW WI. THE NEXT MAIN WAVE OF PRECIPITATION WAS QUICKLY STREAMING NORTHWARD THROUGH THE PLAINS. WE SHOULD SEE AN INCREASE THROUGHOUT THE MORNING ACROSS WESTERN WISCONSIN. DEFINITELY SOME PTYPE ISSUES...AND A THOROUGH ASSESSMENT OF THE FORECAST SOUNDINGS SHOW SOME PRETTY SIGNIFICANT DIFFERENCES AMONG THE MODELS. JUST A FEW DEGREES DIFFERENCE IN THE WARM LAYER WILL MEAN A CHANGE FROM FREEZING RAIN OR RAIN...TO SLEET AND/OR SNOW. FOR TODAY...HAVE RAISED POPS A BIT THROUGHOUT THE DAY...FIRST WITH LIKELY POPS IN THE EASTERN 1/3 OF THE CWA...AND THEN SPREADING IT NORTHWARD AND WESTWARD AS THE MORNING WEARS ON. NAM BUFR SOUNDINGS AND THE HRRR FORECAST PTYPE INDICATE THAT A MIXTURE COULD LAST INTO THE AFTERNOON...AND THERE MAY BE SOME SLEET AS WELL. FORECAST LAYER THICKNESS VALUES ALSO INDICATE SOME POTENTIAL FOR THIS TO LAST INTO THE AFTERNOON AND EVEN TONIGHT. WILL EXTEND THE ADVISORY TIME THROUGH NOON WITH THE CAVEAT THAT SOME AREAS MAY NEED TO BE EXTENDED INTO THE AFTERNOON. HAVE INCREASED POPS CONSIDERABLY TONIGHT AND ON SATURDAY...WITH GENERALLY RAIN DURING THE EVENING AND RAIN AND/OR FREEZING RAIN AFTER MIDNIGHT. IN GENERAL...WE SHOULD SEE MAINLY RAIN ON SATURDAY. TEMPS WILL BE TRICKY DUE TO THE CLOUDS AND EXPECTED PRECIPITATION. .LONG TERM...SATURDAY NIGHT THROUGH THURSDAY. A TROUGH OF LOW PRESSURE AND BAROCLINIC ZONE IS EVIDENT SATURDAY NIGHT...WEAKENING SUNDAY. THIS WILL LEAD TO A CHANCE FOR RAIN OVER MUCH OF THE CWA SATURDAY NIGHT...DIMINISHING FROM NORTH TO SOUTH SUNDAY. RIDGING WILL TAKE OVER MONDAY INTO MONDAY NIGHT AND LEAD TO A DRY PERIOD. CONFIDENCE DIMINISHES MONDAY NIGHT INTO AT LEAST MID WEEK...AS THE ECMWF BRINGS IN A SHORTWAVE AND SUPPORTS THE CHANCE FOR SHOWERS TUESDAY/WEDNESDAY. WE FOLLOWED CLOSER TO THIS SOLUTION DURING THAT PERIOD. THE MODELS THEN HAVE A FASTER WNW FLOW OVER FAR NORTHERN MN/SOUTHERN CANADA BY LATE IN THE WEEK WITH A CONTINUED CHANCE FOR RAIN WITH WEAK LOW PRESSURE AT THE SURFACE. WE HAVE POPS CONTINUING THROUGH THE REST OF THE PERIOD...ALTHOUGH WERE NOT OVERLY IMPRESSED WITH THE FORCING AND EXPECTED PRECIPITATION AMOUNTS. TEMPERATURES WILL BE A BIT BELOW NORMAL SUNDAY...RISING INTO THE SIXTIES MONDAY THROUGH THE END OF THE WEEK. HYDROLOGY... FLOOD WARNINGS CONTINUED FOR THE MISSISSIPPI RIVER AT AITKIN AND FORT RIPLEY FOR MINOR FLOODING. WE DROPPED THE WARNING FOR THE SAINT LOUIS RIVER IN SCANLON AS THERE IS A CLEAR LOWERING TREND. A FLOOD WARNING REMAINS FOR CENTRAL AND SOUTHERN SAINT LOUIS COUNTY AS THERE IS STILL FLOODING OCCURRING THERE WITH WATER OVER SEVERAL ROADS ACCORDING TO THE SAINT LOUIS COUNTY HIGHWAY DEPARTMENT. THE NUMBER OF CLOSED ROADS HAD DIMINISHED SINCE YESTERDAY THOUGH. THERE IS STILL SNOW OVER NORTHERN MINNESOTA...ESPECIALLY IN THE WOODS. COOLER TEMPS TODAY WILL SLOW THE MELT...BUT TEMPS WILL START TO WARM THIS WEEKEND INTO NEXT WEEK...KEEPING ELEVATED RIVERS/STREAMS. WE CONTINUED THE WARNING ACROSS ASHLAND/IRON COUNTIES. THE MONTREAL REMAINS HIGH...AND THE ASHLAND COUNTY COMMISSIONER REPORTED SEVERAL ROADS UNDER WATER AS WELL. ALL THIS SNOW THAT HAS RECENTLY FALLEN WILL START TO MELT THIS WEEKEND ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL UNTIL MONDAY/TUESDAY. THIS SNOWFALL AS WELL AS SNOW THAT WAS ALREADY ON THE GROUND WILL KEEP RIVERS AND STREAMS ELEVATED. THE BAD RIVER HAS FALLEN A COUPLE FEET SINCE YESTERDAY...BUT COULD START TO RISE AGAIN AS THE SNOW MELTS. && .POINT TEMPS/POPS... DLH 37 32 40 36 / 80 80 60 50 INL 47 29 51 33 / 10 10 10 10 BRD 49 34 45 38 / 10 50 60 40 HYR 33 32 44 34 / 90 90 60 30 ASX 34 32 39 33 / 90 90 60 40 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...WINTER WEATHER ADVISORY UNTIL 10 PM CDT THIS EVENING FOR WIZ002>004-007-008. LS...SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ121-143>148. && $$ SHORT TERM...GRANING LONG TERM....CLC AVIATION...CLC
AREA FORECAST DISCUSSION
NWS DULUTH MN
1025 AM CDT FRI MAY 3 2013 .UPDATE... HAVE EXTENDED THE WINTER WEATHER ADVISORY FOR FREEZING RAIN OVER NORTHERN WISCONSIN /EXCEPT PRICE COUNTY/ THROUGH 1000 PM THIS EVENING...POSSIBLY NEEDING TO BE EXTENDED FURTHER. THE 12Z NAM/DLHWRF BOTH SHOW SFC TEMPS REMAIN BELOW FREEZING OVER THE ADVISORY AREA THROUGH AT LEAST MIDNIGHT. MEANWHILE...AN S-SE H85 FLOW WILL CONTINUE TO WARM MID LEVELS THROUGH THE DAY...DIMINISHING ANY LINGERING SNOW AND PROMOTING FREEZING RAIN THIS AFTERNOON/TONIGHT. HAVE INTRODUCED MENTION OF FREEZING RAIN TO MN ARROWHEAD ZONES THIS AFTERNOON AND EVENING WHERE H80-H85 LAYER TEMPS WARM A FEW DEGREES ABOVE 0 C...WHILE SFC READINGS REMAIN SUB-FREEZING. WE WILL CLOSELY MONITOR THIS AREA FOR ICE ACCUM POTENTIAL...AND AN ADVISORY MAY BE NEEDED THIS AFTERNOON/TONIGHT FOR LAKE COOK COUNTIES. && .PREV DISCUSSION... /ISSUED 644 AM CDT FRI MAY 3 2013/ AVIATION...12Z TAFS WAA AND AN INVERTED TROUGH WERE CAUSING SNOW...WITH A WINTRY MIX IN SPOTS OVER NORTHWEST WISCONSIN. MVFR WITH SOME SPOTTY IFR CEILINGS COVERED NORTHWEST WISCONSIN. OVERALL...MVFR OR EVEN SOME IFR CONDITIONS SHOULD SPREAD WEST AND NORTH THROUGH THE DAY INTO TONIGHT. SNOW...OR A WINTRY MIX WILL ALSO SPREAD WEST AND NORTH TODAY. BOUNDARY LAYER TEMPS WILL THEN WARM AND RAIN WILL BECOME MORE WIDESPREAD. FREEZING RAIN WILL THEN BE POSSIBLE AGAIN LATER TONIGHT AS SURFACE TEMPS COOL. PREV DISCUSSION... /ISSUED 408 AM CDT FRI MAY 3 2013/ SHORT TERM...TODAY THROUGH SATURDAY. AT 4 AM...IT WAS FAIRLY QUIET ACROSS THE NORTHLAND. THERE WAS SOME LIGHT SNOW ACROSS NW WI...AND REPORTS JUST OUTSIDE OF THE CWA OF SOME LIGHT FREEZING DRIZZLE. TEMPERATURES RANGED FROM THE 20S IN NE MN TO AROUND 30 IN NW WI. THE NEXT MAIN WAVE OF PRECIPITATION WAS QUICKLY STREAMING NORTHWARD THROUGH THE PLAINS. WE SHOULD SEE AN INCREASE THROUGHOUT THE MORNING ACROSS WESTERN WISCONSIN. DEFINITELY SOME PTYPE ISSUES...AND A THOROUGH ASSESSMENT OF THE FORECAST SOUNDINGS SHOW SOME PRETTY SIGNIFICANT DIFFERENCES AMONG THE MODELS. JUST A FEW DEGREES DIFFERENCE IN THE WARM LAYER WILL MEAN A CHANGE FROM FREEZING RAIN OR RAIN...TO SLEET AND/OR SNOW. FOR TODAY...HAVE RAISED POPS A BIT THROUGHOUT THE DAY...FIRST WITH LIKELY POPS IN THE EASTERN 1/3 OF THE CWA...AND THEN SPREADING IT NORTHWARD AND WESTWARD AS THE MORNING WEARS ON. NAM BUFR SOUNDINGS AND THE HRRR FORECAST PTYPE INDICATE THAT A MIXTURE COULD LAST INTO THE AFTERNOON...AND THERE MAY BE SOME SLEET AS WELL. FORECAST LAYER THICKNESS VALUES ALSO INDICATE SOME POTENTIAL FOR THIS TO LAST INTO THE AFTERNOON AND EVEN TONIGHT. WILL EXTEND THE ADVISORY TIME THROUGH NOON WITH THE CAVEAT THAT SOME AREAS MAY NEED TO BE EXTENDED INTO THE AFTERNOON. HAVE INCREASED POPS CONSIDERABLY TONIGHT AND ON SATURDAY...WITH GENERALLY RAIN DURING THE EVENING AND RAIN AND/OR FREEZING RAIN AFTER MIDNIGHT. IN GENERAL...WE SHOULD SEE MAINLY RAIN ON SATURDAY. TEMPS WILL BE TRICKY DUE TO THE CLOUDS AND EXPECTED PRECIPITATION. LONG TERM...SATURDAY NIGHT THROUGH THURSDAY. A TROUGH OF LOW PRESSURE AND BAROCLINIC ZONE IS EVIDENT SATURDAY NIGHT...WEAKENING SUNDAY. THIS WILL LEAD TO A CHANCE FOR RAIN OVER MUCH OF THE CWA SATURDAY NIGHT...DIMINISHING FROM NORTH TO SOUTH SUNDAY. RIDGING WILL TAKE OVER MONDAY INTO MONDAY NIGHT AND LEAD TO A DRY PERIOD. CONFIDENCE DIMINISHES MONDAY NIGHT INTO AT LEAST MID WEEK...AS THE ECMWF BRINGS IN A SHORTWAVE AND SUPPORTS THE CHANCE FOR SHOWERS TUESDAY/WEDNESDAY. WE FOLLOWED CLOSER TO THIS SOLUTION DURING THAT PERIOD. THE MODELS THEN HAVE A FASTER WNW FLOW OVER FAR NORTHERN MN/SOUTHERN CANADA BY LATE IN THE WEEK WITH A CONTINUED CHANCE FOR RAIN WITH WEAK LOW PRESSURE AT THE SURFACE. WE HAVE POPS CONTINUING THROUGH THE REST OF THE PERIOD...ALTHOUGH WERE NOT OVERLY IMPRESSED WITH THE FORCING AND EXPECTED PRECIPITATION AMOUNTS. TEMPERATURES WILL BE A BIT BELOW NORMAL SUNDAY...RISING INTO THE SIXTIES MONDAY THROUGH THE END OF THE WEEK. HYDROLOGY... FLOOD WARNINGS CONTINUED FOR THE MISSISSIPPI RIVER AT AITKIN AND FORT RIPLEY FOR MINOR FLOODING. WE DROPPED THE WARNING FOR THE SAINT LOUIS RIVER IN SCANLON AS THERE IS A CLEAR LOWERING TREND. A FLOOD WARNING REMAINS FOR CENTRAL AND SOUTHERN SAINT LOUIS COUNTY AS THERE IS STILL FLOODING OCCURRING THERE WITH WATER OVER SEVERAL ROADS ACCORDING TO THE SAINT LOUIS COUNTY HIGHWAY DEPARTMENT. THE NUMBER OF CLOSED ROADS HAD DIMINISHED SINCE YESTERDAY THOUGH. THERE IS STILL SNOW OVER NORTHERN MINNESOTA...ESPECIALLY IN THE WOODS. COOLER TEMPS TODAY WILL SLOW THE MELT...BUT TEMPS WILL START TO WARM THIS WEEKEND INTO NEXT WEEK...KEEPING ELEVATED RIVERS/STREAMS. WE CONTINUED THE WARNING ACROSS ASHLAND/IRON COUNTIES. THE MONTREAL REMAINS HIGH...AND THE ASHLAND COUNTY COMMISSIONER REPORTED SEVERAL ROADS UNDER WATER AS WELL. ALL THIS SNOW THAT HAS RECENTLY FALLEN WILL START TO MELT THIS WEEKEND ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL UNTIL MONDAY/TUESDAY. THIS SNOWFALL AS WELL AS SNOW THAT WAS ALREADY ON THE GROUND WILL KEEP RIVERS AND STREAMS ELEVATED. THE BAD RIVER HAS FALLEN A COUPLE FEET SINCE YESTERDAY...BUT COULD START TO RISE AGAIN AS THE SNOW MELTS. && .POINT TEMPS/POPS... DLH 37 32 40 36 / 80 80 60 50 INL 47 29 51 33 / 10 20 10 10 BRD 49 34 45 38 / 10 60 60 40 HYR 33 32 44 34 / 90 80 60 30 ASX 34 32 39 33 / 90 80 60 40 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...WINTER WEATHER ADVISORY UNTIL 10 PM CDT THIS EVENING FOR WIZ002>004-007-008. WINTER WEATHER ADVISORY UNTIL NOON CDT TODAY FOR WIZ009. LS...SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ121-143>148. && $$ SHORT TERM...GRANING
AREA FORECAST DISCUSSION
NWS DULUTH MN
644 AM CDT FRI MAY 3 2013 .AVIATION...12Z TAFS WAA AND AN INVERTED TROUGH WERE CAUSING SNOW...WITH A WINTRY MIX IN SPOTS OVER NORTHWEST WISCONSIN. MVFR WITH SOME SPOTTY IFR CEILINGS COVERED NORTHWEST WISCONSIN. OVERALL...MVFR OR EVEN SOME IFR CONDITIONS SHOULD SPREAD WEST AND NORTH THROUGH THE DAY INTO TONIGHT. SNOW...OR A WINTRY MIX WILL ALSO SPREAD WEST AND NORTH TODAY. BOUNDARY LAYER TEMPS WILL THEN WARM AND RAIN WILL BECOME MORE WIDESPREAD. FREEZING RAIN WILL THEN BE POSSIBLE AGAIN LATER TONIGHT AS SURFACE TEMPS COOL. && .PREV DISCUSSION... /ISSUED 408 AM CDT FRI MAY 3 2013/ SHORT TERM...TODAY THROUGH SATURDAY. AT 4 AM...IT WAS FAIRLY QUIET ACROSS THE NORTHLAND. THERE WAS SOME LIGHT SNOW ACROSS NW WI...AND REPORTS JUST OUTSIDE OF THE CWA OF SOME LIGHT FREEZING DRIZZLE. TEMPERATURES RANGED FROM THE 20S IN NE MN TO AROUND 30 IN NW WI. THE NEXT MAIN WAVE OF PRECIPITATION WAS QUICKLY STREAMING NORTHWARD THROUGH THE PLAINS. WE SHOULD SEE AN INCREASE THROUGHOUT THE MORNING ACROSS WESTERN WISCONSIN. DEFINITELY SOME PTYPE ISSUES...AND A THOROUGH ASSESSMENT OF THE FORECAST SOUNDINGS SHOW SOME PRETTY SIGNIFICANT DIFFERENCES AMONG THE MODELS. JUST A FEW DEGREES DIFFERENCE IN THE WARM LAYER WILL MEAN A CHANGE FROM FREEZING RAIN OR RAIN...TO SLEET AND/OR SNOW. FOR TODAY...HAVE RAISED POPS A BIT THROUGHOUT THE DAY...FIRST WITH LIKELY POPS IN THE EASTERN 1/3 OF THE CWA...AND THEN SPREADING IT NORTHWARD AND WESTWARD AS THE MORNING WEARS ON. NAM BUFR SOUNDINGS AND THE HRRR FORECAST PTYPE INDICATE THAT A MIXTURE COULD LAST INTO THE AFTERNOON...AND THERE MAY BE SOME SLEET AS WELL. FORECAST LAYER THICKNESS VALUES ALSO INDICATE SOME POTENTIAL FOR THIS TO LAST INTO THE AFTERNOON AND EVEN TONIGHT. WILL EXTEND THE ADVISORY TIME THROUGH NOON WITH THE CAVEAT THAT SOME AREAS MAY NEED TO BE EXTENDED INTO THE AFTERNOON. HAVE INCREASED POPS CONSIDERABLY TONIGHT AND ON SATURDAY...WITH GENERALLY RAIN DURING THE EVENING AND RAIN AND/OR FREEZING RAIN AFTER MIDNIGHT. IN GENERAL...WE SHOULD SEE MAINLY RAIN ON SATURDAY. TEMPS WILL BE TRICKY DUE TO THE CLOUDS AND EXPECTED PRECIPITATION. LONG TERM...SATURDAY NIGHT THROUGH THURSDAY. A TROUGH OF LOW PRESSURE AND BAROCLINIC ZONE IS EVIDENT SATURDAY NIGHT...WEAKENING SUNDAY. THIS WILL LEAD TO A CHANCE FOR RAIN OVER MUCH OF THE CWA SATURDAY NIGHT...DIMINISHING FROM NORTH TO SOUTH SUNDAY. RIDGING WILL TAKE OVER MONDAY INTO MONDAY NIGHT AND LEAD TO A DRY PERIOD. CONFIDENCE DIMINISHES MONDAY NIGHT INTO AT LEAST MID WEEK...AS THE ECMWF BRINGS IN A SHORTWAVE AND SUPPORTS THE CHANCE FOR SHOWERS TUESDAY/WEDNESDAY. WE FOLLOWED CLOSER TO THIS SOLUTION DURING THAT PERIOD. THE MODELS THEN HAVE A FASTER WNW FLOW OVER FAR NORTHERN MN/SOUTHERN CANADA BY LATE IN THE WEEK WITH A CONTINUED CHANCE FOR RAIN WITH WEAK LOW PRESSURE AT THE SURFACE. WE HAVE POPS CONTINUING THROUGH THE REST OF THE PERIOD...ALTHOUGH WERE NOT OVERLY IMPRESSED WITH THE FORCING AND EXPECTED PRECIPITATION AMOUNTS. TEMPERATURES WILL BE A BIT BELOW NORMAL SUNDAY...RISING INTO THE SIXTIES MONDAY THROUGH THE END OF THE WEEK. HYDROLOGY... FLOOD WARNINGS CONTINUED FOR THE MISSISSIPPI RIVER AT AITKIN AND FORT RIPLEY FOR MINOR FLOODING. WE DROPPED THE WARNING FOR THE SAINT LOUIS RIVER IN SCANLON AS THERE IS A CLEAR LOWERING TREND. A FLOOD WARNING REMAINS FOR CENTRAL AND SOUTHERN SAINT LOUIS COUNTY AS THERE IS STILL FLOODING OCCURRING THERE WITH WATER OVER SEVERAL ROADS ACCORDING TO THE SAINT LOUIS COUNTY HIGHWAY DEPARTMENT. THE NUMBER OF CLOSED ROADS HAD DIMINISHED SINCE YESTERDAY THOUGH. THERE IS STILL SNOW OVER NORTHERN MINNESOTA...ESPECIALLY IN THE WOODS. COOLER TEMPS TODAY WILL SLOW THE MELT...BUT TEMPS WILL START TO WARM THIS WEEKEND INTO NEXT WEEK...KEEPING ELEVATED RIVERS/STREAMS. WE CONTINUED THE WARNING ACROSS ASHLAND/IRON COUNTIES. THE MONTREAL REMAINS HIGH...AND THE ASHLAND COUNTY COMMISSIONER REPORTED SEVERAL ROADS UNDER WATER AS WELL. ALL THIS SNOW THAT HAS RECENTLY FALLEN WILL START TO MELT THIS WEEKEND ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL UNTIL MONDAY/TUESDAY. THIS SNOWFALL AS WELL AS SNOW THAT WAS ALREADY ON THE GROUND WILL KEEP RIVERS AND STREAMS ELEVATED. THE BAD RIVER HAS FALLEN A COUPLE FEET SINCE YESTERDAY...BUT COULD START TO RISE AGAIN AS THE SNOW MELTS. && .POINT TEMPS/POPS... DLH 40 32 40 36 / 40 80 60 50 INL 47 29 51 33 / 10 20 10 10 BRD 49 34 45 38 / 10 60 60 40 HYR 42 32 44 34 / 80 80 60 30 ASX 37 32 39 33 / 70 80 60 40 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...WINTER WEATHER ADVISORY UNTIL NOON CDT TODAY FOR WIZ002>004- 007>009. LS...SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ121-143>148. && $$ SHORT TERM...DAP LONG TERM....MELDE AVIATION...MELDE
AREA FORECAST DISCUSSION...CORRECTED
NWS DULUTH MN
408 AM CDT FRI MAY 3 2013 .SHORT TERM...TODAY THROUGH SATURDAY. AT 4 AM...IT WAS FAIRLY QUIET ACROSS THE NORTHLAND. THERE WAS SOME LIGHT SNOW ACROSS NW WI...AND REPORTS JUST OUTSIDE OF THE CWA OF SOME LIGHT FREEZING DRIZZLE. TEMPERATURES RANGED FROM THE 20S IN NE MN TO AROUND 30 IN NW WI. THE NEXT MAIN WAVE OF PRECIPITATION WAS QUICKLY STREAMING NORTHWARD THROUGH THE PLAINS. WE SHOULD SEE AN INCREASE THROUGHOUT THE MORNING ACROSS WESTERN WISCONSIN. DEFINITELY SOME PTYPE ISSUES...AND A THOROUGH ASSESSMENT OF THE FORECAST SOUNDINGS SHOW SOME PRETTY SIGNIFICANT DIFFERENCES AMONG THE MODELS. JUST A FEW DEGREES DIFFERENCE IN THE WARM LAYER WILL MEAN A CHANGE FROM FREEZING RAIN OR RAIN...TO SLEET AND/OR SNOW. FOR TODAY...HAVE RAISED POPS A BIT THROUGHOUT THE DAY...FIRST WITH LIKELY POPS IN THE EASTERN 1/3 OF THE CWA...AND THEN SPREADING IT NORTHWARD AND WESTWARD AS THE MORNING WEARS ON. NAM BUFR SOUNDINGS AND THE HRRR FORECAST PTYPE INDICATE THAT A MIXTURE COULD LAST INTO THE AFTERNOON...AND THERE MAY BE SOME SLEET AS WELL. FORECAST LAYER THICKNESS VALUES ALSO INDICATE SOME POTENTIAL FOR THIS TO LAST INTO THE AFTERNOON AND EVEN TONIGHT. WILL EXTEND THE ADVISORY TIME THROUGH NOON WITH THE CAVEAT THAT SOME AREAS MAY NEED TO BE EXTENDED INTO THE AFTERNOON. HAVE INCREASED POPS CONSIDERABLY TONIGHT AND ON SATURDAY...WITH GENERALLY RAIN DURING THE EVENING AND RAIN AND/OR FREEZING RAIN AFTER MIDNIGHT. IN GENERAL...WE SHOULD SEE MAINLY RAIN ON SATURDAY. TEMPS WILL BE TRICKY DUE TO THE CLOUDS AND EXPECTED PRECIPITATION. .LONG TERM...SATURDAY NIGHT THROUGH THURSDAY. A TROUGH OF LOW PRESSURE AND BAROCLINIC ZONE IS EVIDENT SATURDAY NIGHT...WEAKENING SUNDAY. THIS WILL LEAD TO A CHANCE FOR RAIN OVER MUCH OF THE CWA SATURDAY NIGHT...DIMINISHING FROM NORTH TO SOUTH SUNDAY. RIDGING WILL TAKE OVER MONDAY INTO MONDAY NIGHT AND LEAD TO A DRY PERIOD. CONFIDENCE DIMINISHES MONDAY NIGHT INTO AT LEAST MID WEEK...AS THE ECMWF BRINGS IN A SHORTWAVE AND SUPPORTS THE CHANCE FOR SHOWERS TUESDAY/WEDNESDAY. WE FOLLOWED CLOSER TO THIS SOLUTION DURING THAT PERIOD. THE MODELS THEN HAVE A FASTER WNW FLOW OVER FAR NORTHERN MN/SOUTHERN CANADA BY LATE IN THE WEEK WITH A CONTINUED CHANCE FOR RAIN WITH WEAK LOW PRESSURE AT THE SURFACE. WE HAVE POPS CONTINUING THROUGH THE REST OF THE PERIOD...ALTHOUGH WERE NOT OVERLY IMPRESSED WITH THE FORCING AND EXPECTED PRECIPITATION AMOUNTS. TEMPERATURES WILL BE A BIT BELOW NORMAL SUNDAY...RISING INTO THE SIXTIES MONDAY THROUGH THE END OF THE WEEK. && .AVIATION...06Z TAFS A BAND OF PCPN OVER NW WISCONSIN THAT IS ASSOCIATED WITH A WINTER STORM THAT HAS BEEN AFFECTING THE REGION SINCE LAST NIGHT WILL CONTINUE THROUGH FRIDAY. THE SNOW WILL LIKELY TRANSITION TO A WINTRY MIXTURE OF SNOW/SLEET/-FZRA LATE TONIGHT AND THEN TO -RA BY EARLY FRIDAY AFTERNOON. WIDESPREAD IFR/MVFR CONDITIONS ACROSS NW WISCONSIN WILL LIKELY CONTINUE THROUGH FRIDAY. WIDESPREAD LOW VFR CIGS IN THE 3 TO 4 KFT RANGE WILL PREVAIL ACROSS NE MINNESOTA THROUGH AT LEAST TONIGHT IF NOT FRIDAY. THERE MAY BE TIMES WHERE KDLH/KHIB/KINL FLIRT WITH MVFR CIGS. THE PCPN AND MVFR CIGS OVER NW WISCONSIN WILL LIKELY BEGIN TO MOVE INTO KDLH TOMORROW MORNING OR AFTERNOON AS THE BAND OF PCPN SPREADS WESTWARD...AND THEN INTO THE KBRD AND KHIB AREAS IN THE AFTERNOON OR EVENING. BY THE TIME THE PCPN MOVES INTO KDLH...IT SHOULD MOSTLY BE -RA. && .HYDROLOGY... FLOOD WARNINGS CONTINUED FOR THE MISSISSIPPI RIVER AT AITKIN AND FORT RIPLEY FOR MINOR FLOODING. WE DROPPED THE WARNING FOR THE SAINT LOUIS RIVER IN SCANLON AS THERE IS A CLEAR LOWERING TREND. A FLOOD WARNING REMAINS FOR CENTRAL AND SOUTHERN SAINT LOUIS COUNTY AS THERE IS STILL FLOODING OCCURRING THERE WITH WATER OVER SEVERAL ROADS ACCORDING TO THE SAINT LOUIS COUNTY HIGHWAY DEPARTMENT. THE NUMBER OF CLOSED ROADS HAD DIMINISHED SINCE YESTERDAY THOUGH. THERE IS STILL SNOW OVER NORTHERN MINNESOTA...ESPECIALLY IN THE WOODS. COOLER TEMPS TODAY WILL SLOW THE MELT...BUT TEMPS WILL START TO WARM THIS WEEKEND INTO NEXT WEEK...KEEPING ELEVATED RIVERS/STREAMS. WE CONTINUED THE WARNING ACROSS ASHLAND/IRON COUNTIES. THE MONTREAL REMAINS HIGH...AND THE ASHLAND COUNTY COMMISSIONER REPORTED SEVERAL ROADS UNDER WATER AS WELL. ALL THIS SNOW THAT HAS RECENTLY FALLEN WILL START TO MELT THIS WEEKEND ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL UNTIL MONDAY/TUESDAY. THIS SNOWFALL AS WELL AS SNOW THAT WAS ALREADY ON THE GROUND WILL KEEP RIVERS AND STREAMS ELEVATED. THE BAD RIVER HAS FALLEN A COUPLE FEET SINCE YESTERDAY...BUT COULD START TO RISE AGAIN AS THE SNOW MELTS. && .POINT TEMPS/POPS... DLH 40 32 40 36 / 40 80 60 50 INL 47 29 51 33 / 10 20 10 10 BRD 49 34 45 38 / 10 60 60 40 HYR 42 32 44 34 / 80 80 60 30 ASX 37 32 39 33 / 70 80 60 40 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...WINTER WEATHER ADVISORY UNTIL NOON CDT TODAY FOR WIZ002>004- 007>009. LS...SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ143>146. SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ121-147-148. && $$ SHORT TERM...DAP LONG TERM....MELDE AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
406 AM CDT FRI MAY 3 2013 .SHORT TERM...TODAY THROUGH WEDNESDAY. AT 4 AM...IT WAS FAIRLY QUIET ACROSS THE NORTHLAND. THERE WAS SOME LIGHT SNOW ACROSS NW WI...AND REPORTS JUST OUTSIDE OF THE CWA OF SOME LIGHT FREEZING DRIZZLE. TEMPERATURES RANGED FROM THE 20S IN NE MN TO AROUND 30 IN NW WI. THE NEXT MAIN WAVE OF PRECIPITATION WAS QUICKLY STREAMING NORTHWARD THROUGH THE PLAINS. WE SHOULD SEE AN INCREASE THROUGHOUT THE MORNING ACROSS WESTERN WISCONSIN. DEFINITELY SOME PTYPE ISSUES...AND A THOROUGH ASSESSMENT OF THE FORECAST SOUNDINGS SHOW SOME PRETTY SIGNIFICANT DIFFERENCES AMONG THE MODELS. JUST A FEW DEGREES DIFFERENCE IN THE WARM LAYER WILL MEAN A CHANGE FROM FREEZING RAIN OR RAIN...TO SLEET AND/OR SNOW. FOR TODAY...HAVE RAISED POPS A BIT THROUGHOUT THE DAY...FIRST WITH LIKELY POPS IN THE EASTERN 1/3 OF THE CWA...AND THEN SPREADING IT NORTHWARD AND WESTWARD AS THE MORNING WEARS ON. NAM BUFR SOUNDINGS AND THE HRRR FORECAST PTYPE INDICATE THAT A MIXTURE COULD LAST INTO THE AFTERNOON...AND THERE MAY BE SOME SLEET AS WELL. FORECAST LAYER THICKNESS VALUES ALSO INDICATE SOME POTENTIAL FOR THIS TO LAST INTO THE AFTERNOON AND EVEN TONIGHT. WILL EXTEND THE ADVISORY TIME THROUGH NOON WITH THE CAVEAT THAT SOME AREAS MAY NEED TO BE EXTENDED INTO THE AFTERNOON. HAVE INCREASED POPS CONSIDERABLY TONIGHT AND ON SATURDAY...WITH GENERALLY RAIN DURING THE EVENING AND RAIN AND/OR FREEZING RAIN AFTER MIDNIGHT. IN GENERAL...WE SHOULD SEE MAINLY RAIN ON SATURDAY. TEMPS WILL BE TRICKY DUE TO THE CLOUDS AND EXPECTED PRECIPITATION. .LONG TERM...SATURDAY NIGHT THROUGH THURSDAY. A TROUGH OF LOW PRESSURE AND BAROCLINIC ZONE IS EVIDENT SATURDAY NIGHT...WEAKENING SUNDAY. THIS WILL LEAD TO A CHANCE FOR RAIN OVER MUCH OF THE CWA SATURDAY NIGHT...DIMINISHING FROM NORTH TO SOUTH SUNDAY. RIDGING WILL TAKE OVER MONDAY INTO MONDAY NIGHT AND LEAD TO A DRY PERIOD. CONFIDENCE DIMINISHES MONDAY NIGHT INTO AT LEAST MID WEEK...AS THE ECMWF BRINGS IN A SHORTWAVE AND SUPPORTS THE CHANCE FOR SHOWERS TUESDAY/WEDNESDAY. WE FOLLOWED CLOSER TO THIS SOLUTION DURING THAT PERIOD. THE MODELS THEN HAVE A FASTER WNW FLOW OVER FAR NORTHERN MN/SOUTHERN CANADA BY LATE IN THE WEEK WITH A CONTINUED CHANCE FOR RAIN WITH WEAK LOW PRESSURE AT THE SURFACE. WE HAVE POPS CONTINUING THROUGH THE REST OF THE PERIOD...ALTHOUGH WERE NOT OVERLY IMPRESSED WITH THE FORCING AND EXPECTED PRECIPITATION AMOUNTS. TEMPERATURES WILL BE A BIT BELOW NORMAL SUNDAY...RISING INTO THE SIXTIES MONDAY THROUGH THE END OF THE WEEK. && .AVIATION...06Z TAFS A BAND OF PCPN OVER NW WISCONSIN THAT IS ASSOCIATED WITH A WINTER STORM THAT HAS BEEN AFFECTING THE REGION SINCE LAST NIGHT WILL CONTINUE THROUGH FRIDAY. THE SNOW WILL LIKELY TRANSITION TO A WINTRY MIXTURE OF SNOW/SLEET/-FZRA LATE TONIGHT AND THEN TO -RA BY EARLY FRIDAY AFTERNOON. WIDESPREAD IFR/MVFR CONDITIONS ACROSS NW WISCONSIN WILL LIKELY CONTINUE THROUGH FRIDAY. WIDESPREAD LOW VFR CIGS IN THE 3 TO 4 KFT RANGE WILL PREVAIL ACROSS NE MINNESOTA THROUGH AT LEAST TONIGHT IF NOT FRIDAY. THERE MAY BE TIMES WHERE KDLH/KHIB/KINL FLIRT WITH MVFR CIGS. THE PCPN AND MVFR CIGS OVER NW WISCONSIN WILL LIKELY BEGIN TO MOVE INTO KDLH TOMORROW MORNING OR AFTERNOON AS THE BAND OF PCPN SPREADS WESTWARD...AND THEN INTO THE KBRD AND KHIB AREAS IN THE AFTERNOON OR EVENING. BY THE TIME THE PCPN MOVES INTO KDLH...IT SHOULD MOSTLY BE -RA. && .HYDROLOGY... FLOOD WARNINGS CONTINUED FOR THE MISSISSIPPI RIVER AT AITKIN AND FORT RIPLEY FOR MINOR FLOODING. WE DROPPED THE WARNING FOR THE SAINT LOUIS RIVER IN SCANLON AS THERE IS A CLEAR LOWERING TREND. A FLOOD WARNING REMAINS FOR CENTRAL AND SOUTHERN SAINT LOUIS COUNTY AS THERE IS STILL FLOODING OCCURRING THERE WITH WATER OVER SEVERAL ROADS ACCORDING TO THE SAINT LOUIS COUNTY HIGHWAY DEPARTMENT. THE NUMBER OF CLOSED ROADS HAD DIMINISHED SINCE YESTERDAY THOUGH. THERE IS STILL SNOW OVER NORTHERN MINNESOTA...ESPECIALLY IN THE WOODS. COOLER TEMPS TODAY WILL SLOW THE MELT...BUT TEMPS WILL START TO WARM THIS WEEKEND INTO NEXT WEEK...KEEPING ELEVATED RIVERS/STREAMS. WE CONTINUED THE WARNING ACROSS ASHLAND/IRON COUNTIES. THE MONTREAL REMAINS HIGH...AND THE ASHLAND COUNTY COMMISSIONER REPORTED SEVERAL ROADS UNDER WATER AS WELL. ALL THIS SNOW THAT HAS RECENTLY FALLEN WILL START TO MELT THIS WEEKEND ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL UNTIL MONDAY/TUESDAY. THIS SNOWFALL AS WELL AS SNOW THAT WAS ALREADY ON THE GROUND WILL KEEP RIVERS AND STREAMS ELEVATED. THE BAD RIVER HAS FALLEN A COUPLE FEET SINCE YESTERDAY...BUT COULD START TO RISE AGAIN AS THE SNOW MELTS. && .POINT TEMPS/POPS... DLH 40 32 40 36 / 40 80 60 50 INL 47 29 51 33 / 10 20 10 10 BRD 49 34 45 38 / 10 60 60 40 HYR 42 32 44 34 / 80 80 60 30 ASX 37 32 39 33 / 70 80 60 40 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...WINTER WEATHER ADVISORY UNTIL NOON CDT TODAY FOR WIZ002>004- 007>009. LS...SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ143>146. SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ121-147-148. && $$ SHORT TERM...DAP LONG TERM....MELDE AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1233 AM CDT FRI MAY 3 2013 .AVIATION...06Z TAFS A BAND OF PCPN OVER NW WISCONSIN THAT IS ASSOCIATED WITH A WINTER STORM THAT HAS BEEN AFFECTING THE REGION SINCE LAST NIGHT WILL CONTINUE THROUGH FRIDAY. THE SNOW WILL LIKELY TRANSITION TO A WINTRY MIXTURE OF SNOW/SLEET/-FZRA LATE TONIGHT AND THEN TO -RA BY EARLY FRIDAY AFTERNOON. WIDESPREAD IFR/MVFR CONDITIONS ACROSS NW WISCONSIN WILL LIKELY CONTINUE THROUGH FRIDAY. WIDESPREAD LOW VFR CIGS IN THE 3 TO 4 KFT RANGE WILL PREVAIL ACROSS NE MINNESOTA THROUGH AT LEAST TONIGHT IF NOT FRIDAY. THERE MAY BE TIMES WHERE KDLH/KHIB/KINL FLIRT WITH MVFR CIGS. THE PCPN AND MVFR CIGS OVER NW WISCONSIN WILL LIKELY BEGIN TO MOVE INTO KDLH TOMORROW MORNING OR AFTERNOON AS THE BAND OF PCPN SPREADS WESTWARD...AND THEN INTO THE KBRD AND KHIB AREAS IN THE AFTERNOON OR EVENING. BY THE TIME THE PCPN MOVES INTO KDLH...IT SHOULD MOSTLY BE -RA. && .PREV DISCUSSION... /ISSUED 1003 PM CDT THU MAY 2 2013/ UPDATE... LIGHT SNOW CONTINUES TO FALL ACROSS NW WISCONSIN THIS EVENING. I UPDATED THE FORECAST THROUGH THE REST OF TONIGHT. THE SNOW WILL LIKELY CONTINUE THROUGH THE REST OF THE NIGHT. THERE HAS BEEN A LITTLE BIT OF A LULL THIS EVENING...BUT THE MODELS AND RADAR SUGGEST THE SNOW/PCPN RATES MAY PICK UP A BIT AGAIN AFTER MIDNIGHT. THE LATEST NAM12 SOUNDINGS AND HRRR MODEL RUNS SUGGESTED THE FREEZING RAIN MIGHT NOT BEGIN TO MOVE INTO NW WISCONSIN UNTIL VERY LATE TONIGHT...SO I DELAYED ITS ARRIVAL. THE MAIN CHALLENGE WITH THIS UPDATE WAS TO DETERMINE IF THE WINTER WEATHER HEADLINES ARE STILL GOOD. MUCH OF NW WISCONSIN STILL HAS A WINTER STORM WARNING WHICH IS IN EFFECT THROUGH FRIDAY MORNING. WHILE ONLY LIGHT TO MODERATE SNOW IS EXPECTED THROUGH FRIDAY MORNING...THE THREAT OF FREEZING RAIN LATER TONIGHT AND FRIDAY MORNING HAS ME LEANING ON MAINTAINING THE CURRENT HEADLINES. THERE IS A CHANCE THAT SIGNIFICANTLY MORE FREEZING RAIN COULD FALL THAN FORECASTED. I THINK IT WOULD BE BEST TO FIRST MONITOR THE CHANGE OVER TO MIXED PCPN LATER TONIGHT BEFORE MAKING CHANGES. THE NIGHT SHIFT CAN REEVALUATE WHETHER OR NOT TO CHANGE THE CURRENT WARNINGS AND ADVISORIES. PREV DISCUSSION... /ISSUED 719 PM CDT THU MAY 2 2013/ UPDATE... IT CONTINUES TO SNOW ACROSS NW WISCONSIN EARLY THIS EVENING. IT ALSO APPEARS TO BE SNOWING LIGHT OVER THE EASTERN ARROWHEAD OF MINNESOTA...BUT LITTLE TO NO ADDITIONAL ACCUMULATION IS EXPECTED THROUGH THE REMAINDER OF THE NIGHT. THEREFORE...I LET THE WINTER WEATHER ADVISORY FOR SOUTHERN COOK COUNTY EXPIRE AS PLANNED. I LET THE WINTER STORM WARNINGS AND ADVISORY FOR COUNTIES IN NW WISCONSIN CONTINUE THROUGH TOMORROW MORNING DUE TO THE EXPECTED ADDITIONAL SNOW AND POTENTIAL FREEZING RAIN. THE LATEST NAM12 SOUNDINGS AND HRRR MODEL RUNS SEEM TO INDICATE THE FREEZING RAIN MIGHT NOT BEGIN TO MOVE INTO NW WISCONSIN UNTIL VERY LATE TONIGHT...SO I MIGHT DELAY ITS TIMING IN THE FORECAST WITH A LATER UPDATE LATER THIS EVENING. PREV DISCUSSION... /ISSUED 620 PM CDT THU MAY 2 2013/ AVIATION.../00Z TAF ISSUANCE/ A BAND OF PCPN OVER NW WISCONSIN THAT IS ASSOCIATED WITH A WINTER STORM THAT HAS BEEN AFFECTING THE REGION SINCE LAST NIGHT WILL CONTINUE THROUGH FRIDAY. THE SNOW WILL LIKELY TRANSITION TO A WINTRY MIXTURE OF SNOW/SLEET/-FZRA LATE TONIGHT AND THEN TO -RA BY EARLY FRIDAY AFTERNOON. WIDESPREAD IFR/MVFR CONDITIONS ACROSS NW WISCONSIN WILL LIKELY CONTINUE THROUGH FRIDAY. UNFORTUNATELY...THE OBSERVATION EQUIPMENT AT KHYR IS INOPERABLE...SO I AM UNABLE TO KNOW WHAT IS EXACTLY HAPPENING AT KHYR. I PROVIDED A BEST GUESS FORECAST FOR KHYR THROUGH FRIDAY...AND I WILL NOT BE PLANNING TO MAKE ANY AMENDMENTS FOR THIS SITE. WIDESPREAD LOW VFR CIGS IN THE 3 TO 4 KFT RANGE WILL PREVAIL ACROSS NE MINNESOTA THROUGH AT LEAST TONIGHT IF NOT FRIDAY. THERE MAY BE TIMES WHERE KDLH/KHIB/KINL FLIRT WITH MVFR CIGS. THE PCPN AND MVFR CIGS OVER NW WISCONSIN WILL LIKELY BEGIN TO MOVE INTO KDLH TOMORROW MORNING OR AFTERNOON AS THE BAND OF PCPN SPREADS WESTWARD. BY THE TIME THE PCPN MOVES INTO KDLH...IT SHOULD MOSTLY BE -RA. PREV DISCUSSION... /ISSUED 351 PM CDT THU MAY 2 2013/ SHORT TERM...THROUGH EARLY FRIDAY EVENING. WHAT AN IMPRESSIVE EVENT SO FAR...WITH MAX SNOWFALL SO FAR OF 16 INCHES 8 MILES SOUTH OF HAYWARD AND IN ASHLAND. I THINK IT`S LIKELY THERE WILL BE SOME HIGHER TOTALS THAT COME IN AS ADDITIONAL REPORTS FILTER IN LATE THIS AFTERNOON OR EVENING. OVERALL...SNOWFALL INTENSITY WAS DIMINISHING WITH MOST OBSERVATIONS SHOWING VSBYS AT OR ABOVE THREE QUARTERS OF A MILE. A SPOTTER REPORTED THE SNOW HAD ENDED FOR NOW IN OGEMA IN SOUTHERN PRICE COUNTY. WARM AIR ADVECTION AND A TROUGH SHOULD CAUSE PRECIPITATION TO EXPAND OVERNIGHT OVER NORTHWEST WISCONSIN...AND THE WARMER AIR ALOFT MOVING IN SHOULD CAUSE A WINTRY MIX TO OCCUR BY LATE TONIGHT OR FRIDAY MORNING OVER MOST AREAS OF OUR WISCONSIN CWA. HEADLINES WERE A CHALLENGE OVERNIGHT...AND WE OPTED TO EXTEND THE WARNING FOR ASHLAND/BAYFIELD/IRON/SAWYER AND PRICE COUNTIES...RATHER THAN CHANGE IT OVER TO AN ADVISORY. WE DID CHANGE WASHBURN TO AN ADVISORY...AS MUCH OF THAT COUNTY HAS NOT HAD MUCH ADDITIONAL SNOWFALL. WE`LL RELAY ADDITIONAL SNOWFALL AND POSSIBLE LIGHT ICE ACCUMULATIONS IN THE HWO/STATEMENTS/ZONES/GRAPHICAST. WE EXPECT ANOTHER INCH OR TWO TONIGHT/FRIDAY MORNING...WITH THAT SAME AMOUNT POSSIBLE THIS AFTERNOON INTO EARLY EVENING. MODELS ARE IN DECENT AGREEMENT THROUGH THE PERIOD...AND FINALLY ARE IN GOOD AGREEMENT WITH THE EVOLUTION OF THE UPPER TROUGH THAT WILL CUT OFF A LOW IN THE CENTRAL PLAINS TONIGHT INTO FRIDAY. THE GFS WAS MUCH CLOSER THAN THE ECMWF WITH THIS A COUPLE DAYS AGO. WE DELAYED THE WESTWARD MENTION OF POPS ON FRIDAY AS THE MODELS KEEP THE BULK OF THE PRECIP OVER NORTHWEST WISCONSIN. WE EXPECT A TRANSITION TO MAINLY RAIN BY AFTERNOON AS WARMER TEMPS ALOFT CONTINUE TO ADVECT WEST AND BOUNDARY LAYER TEMPS WARM ABOVE FREEZING. LONG TERM...FRIDAY NIGHT THROUGH THURSDAY. MAIN FOCUS IN EXTENDED IS THREAT FOR FZRA FRIDAY NIGHT AS ANOTHER ROUND OF RAIN LIFTS NORTH OVER THE REGION. AT THIS TIME...THERE IS A POTENTIAL FOR SOME LIGHT ICE ACCUM IS OVER THE WIS ZONES...AS WELL AS IN THE MN ARROWHEAD WHERE SFC TEMPS LOOK TO FALL BELOW FREEZING AS THE MID LEVELS QUICKLY WARM THROUGH THE NIGHT. AN ONSHORE FLOW WITH WATER TEMPS IN THE MID 30S SHOULD KEEP AREAS NEAR LAKE SUPERIOR WARM ENOUGH FOR ALL RA. A COLD CORE LOW IN THE SOUTHERN STREAM...BECOMES CUT-OFF OVER THE SE CONUS THROUGH THE WEEKEND. A H85 TROUGH AND REGION OF FGEN EXTENDING NORTH FROM THE LOW...ACROSS THE NORTHLAND...WILL BE THE FOCUS FOR ONGOING RAIN FRIDAY NIGHT THROUGH SATURDAY NIGHT. THE LATEST NAM/GFS BOTH SHOW PWATS INCREASING FROM THE SOUTHEAST FRIDAY NIGHT...REACHING AROUND AN INCH OVER THE SRN HALF OF THE FA BY SAT AFTRN. MUCH OF THE NORTHLAND CAN EXPECT RAINFALL TOTALS ON THE ORDER OF A HALF TO ONE INCH...WITH LOCALLY HIGHER AMOUNTS. HYDROLOGY... FLOOD WARNINGS CONTINUED FOR THE MISSISSIPPI RIVER AT AITKIN AND FORT RIPLEY FOR MINOR FLOODING. WE DROPPED THE WARNING FOR THE SAINT LOUIS RIVER IN SCANLON AS THERE IS A CLEAR LOWERING TREND. A FLOOD WARNING REMAINS FOR CENTRAL AND SOUTHERN SAINT LOUIS COUNTY AS THERE IS STILL FLOODING OCCURRING THERE WITH WATER OVER SEVERAL ROADS ACCORDING TO THE SAINT LOUIS COUNTY HIGHWAY DEPARTMENT. THE NUMBER OF CLOSED ROADS HAD DIMINISHED SINCE YESTERDAY THOUGH. THERE IS STILL SNOW OVER NORTHERN MINNESOTA...ESPECIALLY IN THE WOODS. COOLER TEMPS TODAY INTO FRIDAY WILL SLOW THE MELT...BUT TEMPS WILL START TO WARM THIS WEEKEND INTO NEXT WEEK...KEEPING ELEVATED RIVERS/STREAMS. WE CONTINUED THE WARNING ACROSS ASHLAND/IRON COUNTIES. THE MONTREAL REMAINS HIGH...AND THE ASHLAND COUNTY COMMISSIONER REPORTED SEVERAL ROADS UNDER WATER AS WELL. ALL THIS SNOW THAT HAS RECENTLY FALLEN WILL START TO MELT THIS WEEKEND ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL UNTIL MONDAY/TUESDAY. THIS SNOWFALL AS WELL AS SNOW THAT WAS ALREADY ON THE GROUND WILL KEEP RIVERS AND STREAMS ELEVATED. THE BAD RIVER HAS FALLEN A COUPLE FEET SINCE YESTERDAY...BUT COULD START TO RISE AGAIN AS THE SNOW MELTS. && .POINT TEMPS/POPS... DLH 42 32 39 35 / 20 80 60 40 INL 48 29 50 32 / 0 10 10 20 BRD 48 34 44 37 / 10 50 60 40 HYR 40 32 43 33 / 70 80 60 30 ASX 37 32 38 33 / 70 80 60 30 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...WINTER STORM WARNING UNTIL 11 AM CDT THIS MORNING FOR WIZ002>004- 008-009. WINTER WEATHER ADVISORY UNTIL 11 AM CDT THIS MORNING FOR WIZ007. LS...SMALL CRAFT ADVISORY FROM 4 AM EARLY THIS MORNING TO 1 AM CDT SATURDAY FOR LSZ144>146. SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ121-147-148. && $$ AVIATION...GROCHOCINSKI/MELDE
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
633 PM CDT SAT MAY 4 2013 .DISCUSSION... HAVE MADE SEVERAL CHANGES TO THE OVERNIGHT FORECAST TO REFLECT ONGOING TRENDS. TEMPERATURES ARE ALREADY IN THE LOW 40S...AND THINK WE WILL SHED AT LEAST A COUPLE OF DEGREES YET TONIGHT. HAVE REDUCED MIN TEMPS IN MOST LOCATIONS OVERNIGHT...ESPECIALLY IN THE WEST/NORTHWEST CWA WHERE TEMPS ARE COOLEST. INCREASED SKY COVERAGE TO 100 PERCENT EVERYWHERE THROUGH THE NIGHT...AS WE WILL BE LOCKED IN STRATUS THROUGH THE REMAINDER OF THE NIGHT AS LOWER CEILINGS INVADE FROM THE EAST. AS FAR AS PRECIPITATION...THOUGHT THE 18Z NAM/12Z 4KM WRF/LATEST FEW RUNS OF RAP HAD A VERY GOOD HANDLE ON THE CURRENT PRECIP DISTRIBUTION...WITH A NARROW BAND OF RAIN IN NORTHEAST NEB AND A MORE ROBUST AREA OF SHOWERS IN EAST CENTRAL IA. THOSE MODELS ERODE THE PRECIPITATION COVERAGE IN IA AS IT SLIDES WESTWARD THROUGH THE NIGHT...LEAVING JUST A FEW SHOWERS BY THE TIME IT REACHES WESTERN IA LATER TONIGHT. HAVE KEPT MOST OF THE CWA FREE OF POPS OVERNIGHT...WITH A PATCHY DRIZZLE MENTION UNDER WEAK LIFT AND ABUNDANT LOW-LEVEL MOISTURE. DID HOLD ONTO A CHANCE POP IN THE NORTHWEST CWA EARLY THIS EVENING...AS THE BAND OF SCATTERED COVERAGE MOVES ACROSS...AS WELL AS A CHANCE IN THE EAST TONIGHT AS THE DISSIPATING AREAS OF SHOWERS REACH WESTERN IA. MAYES && .AVIATION... 00Z TAFS FOR KOMA...KLNK...AND KOFK. IFR CONDITIONS ARE EXPECTED THIS EVENING AND TONIGHT...WITH IMPROVING CONDITIONS BY SUNDAY AFTERNOON. IFR CEILINGS ARE ALREADY OVER KOMA AND WILL OVERSPREAD KLNK/KOFK LATER THIS EVENING. MAY SEE PATCHY DZ AT THE SITES TONIGHT...BUT WILL LIKELY KEEP MENTION OUT UNLESS IT BECOMES MORE WIDESPREAD. DID INCLUDE MVFR VIS AT ALL SITES OVERNIGHT. CEILINGS SHOULD LIFT TO MVFR BY MID-MORNING AND TO VFR BY MIDDAY OR EARLY AFTERNOON. NORTH WINDS ARE EXPECTED TO REMAIN AT OR BELOW 10KT THROUGH THE PERIOD. MAYES && .PREV DISCUSSION... /ISSUED 249 PM CDT SAT MAY 4 2013/ DISCUSSION... LARGE CLOSED UPPER LOW CONTINUES TO SLOWLY SPIN ACROSS NORTHWESTERN ARKANSAS...WITH MOISTURE CONTINUING TO MOVE FROM EAST TO WEST THROUGH THE FORECAST AREA. FIRST WAVE MOVED IN LATE LAST NIGHT THROUGH THIS MORNING...WHICH BROUGHT WIDESPREAD PRECIPITATION TO THE FORECAST AREA...WHICH CONTINUES THIS AFTERNOON ALONG AND NORTH OF I80...WHICH HAS MOSTLY BEEN RAIN ALTHOUGH A FEW SNOW FLAKES WERE NOTED FROM TIME TO TIME. THIS FIRST BATCH OF VERY LIGHT PRECIP WILL CONTINUE TO PUSH WEST NORTHWEST THROUGH THE NORTHERN CWA EARLY THIS EVENING. MEANWHILE...THE NEXT BATCH OF SIMILAR PRECIPITATION IS CURRENTLY MOVING THROUGH THE MID MISSISSIPPI RIVER VALLEY AND SHOULD BEGIN TO MOVE INTO OUR AREA BY VERY LATE THIS EVENING AND AFTER MIDNIGHT. THERE WILL BE A DRY PERIOD IN BETWEEN THE FIRST AND SECOND WAVES...AND ITS ENTIRELY POSSIBLE THAT PARTS OF SOUTHEAST NEBRASKA COULD REMAIN DRY OVERNIGHT...BUT CLOUDY. AS THE UPPER LOW CONTINUES TO DRIFT SLOWLY EAST SOUTHEAST THROUGH THE DAY SUNDAY...OUR REGION IS LEFT IN A COL AREA WITH LINGERING TRAPPED MOISTURE...WITH SCATTERED SHOWERS IN THE MORNING...WITH DIMINISHING COVERAGE IN THE AFTERNOON...AND SHOULD BE OVER BY SUNDAY EVENING AS WEAK RIDGING BUILDS IN ALOFT. MONDAY MORNING WILL PROBABLY BE DRY...BUT LEFT IN A SLIGHT CHANCE OF SHOWERS MONDAY AFTERNOON AS LAPSE RATES STEEPEN ALTHOUGH CYCLONIC FORCING BY THAT TIME IS ALMOST NON EXIST. FOR THE EXTENDED FORECAST...THE UPPER CLOSED LOW THAT EXISTS ACROSS THE WEST COAST WILL CONTINUE TO DEEPEN AND MAY EVEN RETROGRADE THROUGH MONDAY. MEANWHILE...THE FIRST PIECE OF THIS SYSTEM MOVING INTO THE CALIFORNIA BAJA REGION TODAY APPEARS TO BE MOVING THROUGH THE PLAINS BY TUESDAY/WEDNESDAY WHICH WILL BRING MORE SHOWERS AND PROBABLY THUNDERSTORMS AS INSTABILITY INCREASES... ALTHOUGH SIGNIFICANT LOW LEVEL MOISTURE IS NOT EXPECTED. MEANWHILE...THE UPPER CLOSED LOW MOVES INTO THE CENTRAL ROCKIES AND BEGINS EJECTING SMALL WAVES INTO ONTO THE PLAINS THROUGH THE REMAINDER OF THE WEEK WHICH WILL BRING DAILY CHANCES FOR RAIN. AGAIN...NOT THAT IT WILL BE A CONTINUOUSLY RAINY PERIOD...BUT IT SHOULD DEFINITELY BE A MORE ACTIVE PERIOD. ALSO DURING THIS TIME...A SUBTLE COOL FRONT APPEARS TO BE SETTLING SOUTHWARD THROUGH THE AREA...TRANSITIONING WINDS FROM SOUTH EARLY IN THE PERIOD TO EAST NORTHEAST BY FRIDAY AND SATURDAY. DEWALD && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
135 PM EDT FRI MAY 3 2013 .SYNOPSIS... HIGH PRESSURE CENTERED OVER NEW ENGLAND AND THE CANADIAN MARITIMES WILL CONTINUE TO PROVIDE OUR REGION WITH BEAUTIFUL WEATHER THROUGH THE WEEKEND INTO EARLY NEXT WEEK. TEMPERATURES DURING THAT STRETCH WILL REMAIN ABOVE NORMAL WITH AFTERNOON HIGHS GENERALLY IN THE 70S. LOOKING FURTHER DOWN THE ROAD...THERE IS LITTLE IF ANY CHANCE FOR WIDESPREAD PRECIPITATION THROUGH NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... GORGEOUS SPRING WEATHER WILL BE FOUND ACROSS ALL OF WESTERN AND NORTH CENTRAL NEW YORK THIS AFTERNOON AS HIGH PRESSURE OVER NEW ENGLAND WILL KEEP A WEALTH OF SUNSHINE IN PLACE. IT WILL QUITE MILD AS H85 TEMPS IN THE VCNTY OF 10C WILL SUPPORT MID AFTERNOON HIGHS IN THE UPPER 70S ACROSS THE LAKE PLAINS...AS WELL AS IN THE GENESEE AND SOUTHERN TIER VALLEYS. ONCE AGAIN...THE COOL SPOTS WILL BE NEAR LAKE ONTARIO WHERE A LAKE BREEZE SHOULD KEEP READINGS IN THE 60S. SPEAKING OF WHICH...THE KBUF RADAR IS ONCE AGAIN DOING A FINE JOB OF ILLUMINATING THE LAKE BREEZE BOUNDARY OFF LAKE ONTARIO. AS OF 1730Z THE FRONT WAS SLOWLY SETTLING SOUTH ACROSS THE SOUTHERN PORTIONS OF NIAGARA AND ORLEANS COUNTIES AND EXTENDED TO JUST NORTH OF ROCHESTER. THE HRRR SIMULATION IS HANDLING THIS THE BEST OF THE FINER SCALE GUIDANCE PACKAGES. OTHERWISE... THE HIGH AMPLITUDE OMEGA BLOCK RESPONSIBLE FOR THIS STRETCH OF FINE WEATHER WILL GENERALLY REMAIN IN PLACE THROUGH SATURDAY...ALTHOUGH DEEP CLOSED LOWS OVER THE SOUTHERN PLAINS AND EASTERN ATLANTIC WILL PINCH OFF THE SRN PORTION OF THE BLOCKING RIDGE. WHILE THE CORE OF THE HIGH WILL REMAIN IN PLACE OVER OUR REGION...THE AFOREMENTIONED ERODING OF ITS SOUTHERN FLANK WILL ALLOW LOWER H85 TEMPS TO ADVECT WESTWARD FROM THE COAST. AS A RESULT...H85 TEMPS WILL SETTLE TO BETWEEN 6 AND 8C WHICH IN TURN WILL KEEP SATURDAYS HIGH TEMPS A BIT LOWER (ABT 5 DEG F) THAN THOSE FROM THE PAST COUPLE DAYS. IN TERMS OF LOW TEMPS TONIGHT...IT WILL ALSO BE A BIT COOLER WITH MINS DROPPING BACK CLOSER TO TYPICAL ERLY MAY VALUES. TEMPS BY DAYBREAK WILL RANGE FROM THE MID AND UPPER 30S IN THE SRN TIER VALLEYS TO THE LOWER 50SALONG THE IAG ESCARPMENT FROM IAG TO ROC. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/... SURFACE HIGH PRESSURE WILL REMAIN ACROSS THE NORTHEASTERN STATES THROUGH THE WEEKEND. THIS WILL KEEP AN EXTENDED PERIOD OF FAIR AND WARM WEATHER ACROSS WESTERN NEW YORK. SKIES SHOULD BE MOSTLY CLEAR FOR THE WEEKEND...OUTSIDE OF PERHAPS SOME SCATTERED CUMULUS INLAND OF THE LAKE BREEZE. 850MB TEMPS AVERAGING AROUND +6C WILL YIELD AFTERNOON HIGH TEMPS A LITTLE LESS WARM THAN THE RECENT PAST FEW DAYS. HIGHS WILL BE IN THE LOWER TO MID 70S FOR MOST LOCATIONS...BUT A WELL DEVELOPED LAKE BREEZE CIRCULATION WILL BRING COOLER LAKE AIR A LITTLE FARTHER INLAND. THIS WILL BE ESPECIALLY TRUE ON SUNDAY WHEN A NORTHERLY WIND DEVELOPS FOLLOWING WHAT APPEARS TO BE A WEAK AND VERY DRY BACKDOOR FRONT. LOW TEMPERATURES WILL ALSO BE MILD THROUGH THE PERIOD...WITH LOWS AROUND 50 ON THE LAKE PLAINS OF WESTERN NY...WITH 40S ACROSS THE INTERIOR AND EAST OF LAKE ONTARIO. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE FORECAST FOR NEXT WEEK CONTINUES TO DEPEND ON THE PROGRESSION OF A CUT-OFF LOW. WHILE SOME DETAILS STILL REMAIN UNCERTAIN...MODEL CONSENSUS HAS COME INTO BETTER AGREEMENT OVER THE PAST COUPLE RUNS. EXPECT THE CLOSED LOW TO START THE WEEK ACROSS THE SOUTHEASTERN STATES. CONSENSUS THEN LIFTS THE LOW NORTHWARD TO THE MID-ATLANTIC STATES TOWARD MID-WEEK...AND THEN THE LOW WILL LIKELY SLIDE TO THE EAST AND OFF THE ATLANTIC COAST THURSDAY. WHILE THERE IS STILL SOME CHANCE THE LOW WILL REACH US...THE VAST MAJORITY OF GUIDANCE KEEPS THE UPPER LOW TOO FAR SOUTH TO BRING ANY PRECIPITATION TO OUR REGION. IF THIS CONSENSUS HOLDS...EXPECT ANOTHER WEEK OF NICE WEATHER WITH ABOVE NORMAL TEMPERATURES. THERE MAY BE A BIT MORE CLOUD COVER AS A RESULT OF THE UPPER LOW. HOWEVER...850 MB TEMPERATURES SHOULD CONTINUE TO RUN AROUND +10C. THIS WOULD ALLOW DAYTIME HIGHS TO CONTINUE TO CLIMB INTO THE 70S THROUGH THE END OF THE WEEK. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... HIGH PRESSURE WILL KEEP LIGHT WINDS AND VFR CONDITIONS IN PLACE THROUGH AT LEAST SATURDAY. THE ONLY REAL FORECAST CHALLENGE WILL BE TIMING OF THE LAKE BREEZE BOUNDARY OFF LAKE ONTARIO...WHICH WILL DROP SOUTH OF IAG/BUF AND ROCHESTER AFTER 19Z THIS AFTERNOON...AND AGAIN SATURDAY AFETRNOON. OUTLOOK... SUNDAY THROUGH WEDNESDAY...VFR. && .MARINE... HIGH PRESSURE DOMINATING THE NORTHEASTERN UNITED STATES WILL PERSIST THROUGH THE WEEKEND WITH LIGHT SOUTHEASTERLY FLOW RESULTING IN TRANQUIL CONDITIONS ON THE LAKES. LAKE BREEZES WILL SET UP IN THE EACH AFTERNOON. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...RSH NEAR TERM...RSH SHORT TERM...WCH LONG TERM...APFFEL AVIATION...RSH MARINE...TMA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
106 AM EDT FRI MAY 3 2013 .SYNOPSIS... STRONG HIGH PRESSURE WILL REMAIN ANCHORED NORTH OF THE REGION TODAY THROUGH THE WEEKEND. AN APPROACHING LOW PRESSURE SYSTEM WILL BRING UNSETTLED WEATHER TO THE CAROLINAS EARLY NEXT WEEK. FAIR WEATHER IS EXPECTED TO FOLLOW THIS SYSTEM THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS OF 106 AM FRIDAY...BASED ON LATEST KLTX AND SURROUNDING 88DS AND THE LATEST HRRR OUTPUT AND THE 00Z NAM...THE BULK OF THE PCPN IN THE FORM OF STRATIFORM R- AND L- TO REMAIN OVER THE ADJACENT ATLANTIC WATERS. A TRAJECTORY RUNNING FROM ENE TO WSW FROM THE CURRENT PCPN OVER THE ATL WATERS...WILL BRUSH ACROSS THE COASTAL COUNTIES OVERNIGHT. WILL THE SLIGHT CHANCE ALONG THE IMMEDIATE COAST FOR ANY ONSHORE MOVEMENT. LATEST NAM MODEL AND GFS MOS INDICATES A RANGE OF LOWS FROM LOW TO MID 50S NE PORTIONS OF THE CWA TO MID AND UPPER 50S SOUTHERN PORTIONS. DEWPOINTS ONLY A FEW TICKS BELOW TEMPS DURING THE OVERNIGHT. NE WINDS TO STAY ACTIVE OVERNIGHT ALONG WITH INTERVALS OF CLOUDS...THUS PREVENTING ANY FOG DEVELOPMENT. POCKETS OF DRIZZLE ALONG THE IMMEDIATE COAST OVERNIGHT COULD TEMPORARILY BRING DOWN VSBYS. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... AS OF 3 PM THURSDAY...MAIN FORECAST CHALLENGE IS THE POSSIBILITY OF THE INTERVALS OF NUISANCE RAIN/DRIZZLE CONTINUING FOR THE NEXT COUPLE OF DAYS. ALTHOUGH THERMAL PROFILES CONTINUE TO DRY OUT...THE FACT THAT THE NATURE OF THE SHOWERS HAS BEEN AND IS VERY SHALLOW. THIS ALMOST GOES WITHOUT SAYING WITH DRIZZLE. THE GFS...NAM AS WELL AS SREF PLUME DIAGRAMS SHOW SMALL AREAS OF QPF INDICATIVE OF THIS ACTIVITY CONTINUING THROUGH SATURDAY...THEREFORE...I HAVE ADDED THIS TO THE FORECAST. TIMING IS DIFFICULT BUT LEANED TOWARD THE NAM TO SHOW AN INCREMENTAL DIFFERENCE WITH A SLIGHT INCREASE BOTH FRIDAY AND SATURDAY MORNINGS. ONLY SMALL CHANGES TO TEMPERATURE FORECAST. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 3 PM THURSDAY...CLIMATOLOGICALLY UNUSUAL SETUP THROUGH MOST OF THE PERIOD MAKING FOR SOME INTERESTING AND CHALLENGING FORECASTS. DEEP CUTOFF UPPER LOW WILL APPROACH AND EVENTUALLY TRAVERSE THE CAROLINAS...WHICH IS MUCH MORE TYPICAL OF WINTER OR MUCH EARLIER IN THE SPRING. IT IS MORE THE ISOLATION FROM THE FLOW OF THIS FEATURE RATHER THAN ITS UNUSUAL TIMING THAT MAKES THE FORECAST CHALLENGING SINCE SUCH FEATURES ARE USUALLY POORLY HANDLED BY MODEL GUIDANCE. THAT SAID THE MODELS HAVE COME INTO PRETTY GOOD AGREEMENT WITH THE EVOLUTION OF THE PATTERN. THERE WILL STILL BE SOME FUTURE REFINEMENTS IN THE TIMING POSSIBLE AND THE WEATHER ITSELF WILL BE QUITE COMPLEX AS WE SHOULD GO THROUGH SOME DISTINCT REGIME CHANGES THROUGH THE PERIOD. SUNDAY APPEARS TO BE THE LAST DAY IN THE PRE FRONTAL FLOW AHEAD OF THE UPPER LOW. MOISTURE WILL BE RAPIDLY ON THE RISE ESP ACCORDING TO THE RELATIVELY FASTER GFS. BEST FORCING IN THE FORM OF MID LEVEL JETTING AND HEIGHT FALLS COME EITHER LATE SUNDAY OR SUNDAY NIGHT INTO MONDAY AGAIN DEPENDING ON MODEL SOLN. RAINFALL CHANCES AND QPF POTENTIAL ARE STARTING TO LOOK PRETTY GOOD WITH SUCH STRONG FORCING AND DEEP ATLANTIC MOISTURE EXPECTED. THEN THE SYNOPTIC SCALE DRY SLOT WILL MOVE ACROSS THE AREA SHUTTING OFF THE RAINFALL FOR ABOUT A PERIOD. WE WILL THEN MOVE INTO A VERY CONVECTIVE REGIME AS THE COLD POOL ALOFT CRAWLS ACROSS THE REGION. RIGHT NOW BEST ESTIMATE IS THIS IS TUESDAY...WHICH COULD BE A BUSY DAY WITH A RADAR SCOPE FULL OF SMALL HAIL PRODUCING SHALLOW TSTMS. RAIN CHANCES WILL BE SMALLER FOR THE REMAINDER OF THE PERIOD AS THE SLOW MOVING SYSTEM COULD STILL PLAGUE THE COASTAL CAROLINAS WITH WRAP-AROUND MOISTURE. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 05Z...LIGHT PRECIPITATION IS AGAIN MOVING ONSHORE NEAR KILM BUT THE MAJORITY IS REMAINING OFFSHORE. SCATTERED LOW CLOUDS 1-2K ARE INCREASING UPSTREAM OF THE COASTAL TERMINALS WITH CLOUDS EXPANDING WEST FROM THE PRECIPITATION AREA ALONG THE COAST. CIGS AND VSBYS ARE CURRENTLY VFR. HIGH PRESSURE WILL CONTINUE ACROSS THE TERMINALS THIS TAF VALID PERIOD RESULTING IN A CONTINUED MOIST ENE-E LOW-MID LEVEL FLOW. THERE IS MODERATE CONFIDENCE MVFR CIGS WILL DEVELOP AS ADVERTISED IN TAFS WITH THE LOWEST CONFIDENCE IN TIMING. CONFIDENCE HAS LOWERED THAT IFR WILL OCCUR AT THE COASTAL TERMINALS...ALTHOUGH IF ANY LIGHT RAIN OCCURS THERE COULD BE TEMPO PERIODS OF IFR. BEST CONFIDENCE OF IFR REMAIN AT KFLO. MVFR CONDITIONS WILL BE LIKELY AT ALL TERMINALS THROUGH THE MORNING HOURS. ALL MODELS SUGGEST INCREASING MID LEVEL MOISTURE AFTER 12Z INITIALLY AT THE COASTAL TERMINALS. THIS COULD INCREASE THE CHANCES OF PRECIPITATION. SOME OF THIS PRECIPITATION COULD MOVE WEST TO THE INLAND TERMINALS BY AFTERNOON. EXTENDED OUTLOOK...SLIGHT CHANCE OF SHOWERS ESPECIALLY COASTAL TERMINALS THROUGH SUNDAY. IFR/MVFR EARLY SUNDAY WITH RAIN/ISOLATED THUNDERSTORMS DEVELOPING SUNDAY EVENING PERSISTING THROUGH MONDAY. MVFR/TEMPO IFR POSSIBLE. VFR/TEMPO MVFR WITH SCATTERED SHOWERS TUESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 106 AM FRIDAY...SCA EXTENDED FOR ALL WATERS TO 6 PM SATURDAY...MAY 4TH. PERSISTENCE THE WORD HERE FOR WINDS. CURRENT NE WINDS BASICALLY REMAIN AT THESE SPEEDS FOR THE OVERNIGHT PERIOD. OF NOTE...HRRR AND NAM INDICATE A MORE EASTERLY WIND DIRECTION AND 3 TO 5 KT SUSTAINED HIER SPEEDS FOR THE ADJACENT OFFSHORE WATERS. THIS WILL LIKELY HAVE IMPLICATIONS ON SIGNIFICANT SEAS OVERNIGHT...ESPECIALLY THE OUTER WATERS OFF THE CAPES...FEAR AND ROMAIN. OVERALL...HAVE INCREASED SIGNIFICANT SEAS BY 1 FOOT...HIGHEST AT 8 FT...ACROSS ALL WATERS...AND WOULD NOT BE SURPRISED TO OBSERVE 2 FT HIER...HIGHEST AT 9 FT...MAINLY ACROSS THE OUTER WATERS 15 TO 20 NM OUT FROM THE CAPES. AVERAGE PERIODS OVERNIGHT WILL RUN 5 TO 6 SECONDS. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 PM THURSDAY...PERSISTENT NORTHEAST FLOW CONTINUES THROUGH THE PERIOD. THERE MAY BE A LITTLE VEERING VERY LATE IN THE PERIOD TO MORE OF A EASTERLY FLOW BUT OVERALL...THE NE FLOW WILL BE THE STORY. STRONGEST WINDS WILL OCCUR FRIDAY WITH A FEW AREAS ACROSS THE OUTER WATERS POSSIBLY EXCEEDING 25 KNOTS. FOR NOW THINK THESE SPEEDS WILL BE LIMITED IN DURATION TO KEEP GALE CONSIDERATION IN CHECK. SEAS WILL REMAIN RUGGED THROUGH THE PERIOD AND WILL ALMOST CERTAINLY SEE THE SMALL CRAFT ADVISORY CONTINUE. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 3 PM THURSDAY...FAIRLY COMPLEX AND ACTIVE WEATHER EXPECTED FOR MOST OF THE PERIOD ESPECIALLY EARLY ON. A DEEPLY CUTOFF UPPER SYSTEM WILL APPROACH FROM THE WEST ON SUNDAY WITH A COLD FRONT ALONG ITS LEADING EDGE. ONSHORE/EASTERLY FLOW WILL GET PINCHED BY THIS APPROACHING BOUNDARY AS HIGH PRESSURE NOSED INTO THE CAROLINAS TRIES TO HOLD ITS GROUND. AT SOME POINT THERE SHOULD BE SOME PRETTY SHARP VEERING AS THE HIGH LOSES GROUND TO THE APPROACHING FRONT...AND THIS IS PROBABLY THE MOST UNCERTAIN PART OF THE FORECAST. SOUTHERLY FLOW SHOULD OVERSPREAD BY MONDAY WITH ADDITIONAL VEERING DUE TO THE CYCLONIC CURVATURE OF THE ISOBARS COMING ACROSS THE CAROLINAS MONDAY NIGHT INTO TUESDAY. ALL OF THE CHANGING OF THE WIND DIRECTION THROUGH THE PERIOD SHOULD KEEP WAVE FACES RATHER STEEP AND PERIODS SHORT MAKING FOR CHOPPY CONDITIONS. WHETHER OR NOT ANY CAUTIONARY HEADLINES OR EVEN ADVISORIES ARE NEEDED TO TO WAVE HEIGHTS IS VERY UNCERTAIN BUT WIND SPEEDS WILL REMAIN SHY OF EITHER. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR AMZ250-252- 254-256. && $$ NEAR TERM...DCH/MJC SHORT TERM...SHK LONG TERM...MBB AVIATION...MRR/MJC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
714 PM CDT SAT MAY 4 2013 .UPDATE... ISSUED AT 711 PM CDT SAT MAY 4 2013 FCST ON TRACK PRETTY GOOD. DID ADJUST CURRENT TEMPS A BIT AS TEMPS IN FAR EAST NEVER GOT OUT OF THE 30S. OTHERWISE MOVED RAIN AREA A TAD FURTHER WEST AND WENT 80-90 BACK TO FORMAN-CENTRAL CASS CO- CROOKSTON TO BAUDETTE AS RAIN HAS MADE IT THAT FAR WEST. DONT THINK IT WILL MAKE IT MUCH FARTHER WEST. WENT CATEGORICAL IN THIS BAND THROUGH 09Z THEN BACKED OFF AS DRIER AIR WORKS IN FROM THE NORTHWEST AFTER THAT TIME. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 342 PM CDT SAT MAY 4 2013 MAIN CHALLENGE FOR THIS FORECAST PACKAGE WILL BE PCPN. LATEST ANALYSIS SHOWS UPPER LOW OVER NRN ARKANSAS. EXPECT SLOWER CHANGES TO THE LOCAL WEATHER OVER THE NEXT FEW DAYS AS THE OVERALL PATTERN SHOWS A REX BLOCK OVER WRN CONUS AND ANOTHER BLOCK OVER THE EAST COAST. MODELS INITIALIZED WELL AND AND OPTED FOR A BLENDED SOLN. FOR TODAY AND TONIGHT...MAIN QUESTION IS WHERE AREA OF PCPN WILL SETTLE. REGIONAL RADAR SHOWS BAND OF PCPN MOVING NORTH INTO WEST CENTRAL AND NW MINNESOTA. HRRR AND RAP MODELS IN GENERAL AGREEMENT ON PLACEMENT OF PCPN AND EXPECT MOST PCPN AMOUNTS WILL BE UNDER A QUARTER INCH OVER THE NEXT 24 HOURS. THE 300K ISENTROPIC ANALYSIS SHOWS SOME DECENT LIFT AND EXPECTING AN 850MB BAROCLINIC ZONE TO SET UP. HOWEVER...CONDENSATION PRESSURE DEFICITS WEAK SO FOR NOW WILL ONLY KEEP LIKELY POPS IN THAT AREA. FOR SUNDAY...LOOKING FOR THE BAROCLINIC ZONE TO SLOWLY SLIDE SOUTHEAST AND WILL SEE THE END OF PCPN. OTHERWISE...LOOKING FOR DRIER WEATHER GOING INTO MONDAY. EXTENSIVE CLOUD COVER WILL KEEP TEMPERATURES A BIT LOWER TODAY INTO SUNDAY WHEN THE UPPER RIDGE BEGINS SLIDE OVER THE AREA AND A WARMING TREND BEGINS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 342 PM CDT SAT MAY 4 2013 12 UTC GFS/ECMWF SHOW THE FORECAST AREA IN POORLY DEFINED SPLIT FLOW MID-WEEK...TRANSITIONING TO NORTHWEST FLOW ALOFT FRIDAY NIGHT INTO SATURDAY WITH A STRONG CANADIAN COLD FRONT. PRECIPITATION CHANCES THROUGH FRIDAY WILL DEPEND ON EVOLUTION OF A WEAK CUT-OFF LOW ACROSS THE SOUTHERN ROCKIES. MOST MODELS PAINT MOST QPF ACROSS THE CENTRAL PLAINS...BUT SOME DOES MAKE IT FARTHER NORTH. WITH THESE CUT-OFF LOWS NOT A LOT OF CONFIDENCE...SO WILL KEEP ALL BLEND 20-40 POPS FOR MOST OF THE WEEK. HOWEVER...THERE SHOULD BE MORE DRY PERIODS THAN WET. WILL ALSO LIMIT THUNDER MENTION AS INSTABILITY APPEARS TO BE MINIMAL AT THIS TIME. TEMPERATURES WILL BE ON THE WARM-SIDE OF THE MOST RECENT THERMAL REGIME WITH HIGHS IN THE 60S AND LOWS MAINLY IN THE 40S. IT DOES APPEAR CONDITIONS WILL COOL ON SATURDAY WITH PASSAGE OF THE FRONT FRIDAY NIGHT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 711 PM CDT SAT MAY 4 2013 QUESTION OVERNIGHT IS CEILINGS. BEMIDJI HANGING AROUND IFR CIGS WITH LIGHT RAIN/DRIZZLE AND I THINK A GOOD CHANCE TO GO IFR CIGS AFTER DARK THROUGH THE OVERNIGHT. FARGO-THIEF RIVER RIVER CIGS HOLDING THAT MVFR-VFR THRESHOLD AND WILL MAINTAIN THAT RANGE THROUGH THE NIGHT. GFK-DVL WILL REMAIN VFR...HIGH END STRATOCU IN GFK AND CIRRUS AT DVL. ALL AREAS WILL SEE NORTHEAST WINDS DIMINISH TO UNDER 10 KTS. && .HYDROLOGY... ISSUED AT 1258 PM CDT SAT MAY 4 2013 THE BROAD CREST WAVE OF SNOWMELT RUNOFF IS APPROACHING THE DRAYTON AREA THIS WEEKEND WITH A CREST EXPECTED NEAR 40 FEET. THE CREST WAVE WILL MOVE INTO THE PEMBINA REGION TOWARD THE END OF NEXT WEEK WITH A FORECAST NEAR 48.5 FEET...JUST UNDER MAJOR FLOOD STAGE. A SECOND ROUND OF RUNOFF IS EXPECTED ALONG THE PEMBINA RIVER WITH ADDITIONAL RISES FORECAST AT WALHALLA AND NECHE THIS NEXT WEEK. ELSEWHERE RIVERS CONTINUE TO RECEDE AS NO NEW RUNOFF IS OCCURRING WITH THE DRY WEATHER OVER THE PAST WEEK. AREAL FLOODING...WILL KEEP THE NORTH DAKOTA WARNINGS GOING AS OVERLAND FLOODING CONTINUES TO CAUSE ISSUES AND ROAD CLOSURES. AS FOR THE BELTRAMI AND CLEARWATER COUNTIES WILL CANCEL AFTER CONFIRMING WITH COUNTY OFFICIALS THAT OVERLAND WATER HAS DIMINISHED DRAMATICALLY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...RIDDLE SHORT TERM...HOPKINS LONG TERM...ROGERS AVIATION...RIDDLE HYDROLOGY...JK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
950 AM EDT FRI MAY 3 2013 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OVER NEW ENGLAND THROUGH THE WEEKEND THEN BEGIN TO WEAKEN EARLY NEXT WEEK. LOW PRESSURE EXTENDING UP THE MISSISSIPPI VALLEY TO LAKE MICHIGAN WILL REMAIN STATIONARY INTO SATURDAY THEN SLOWLY MOVE EAST THROUGH THE LOWER TENNESSEE VALLEY. && .NEAR TERM /THROUGH TONIGHT/... ONLY MINOR CHANGES PLANNED FOR THE FORECAST. THE 12Z SOUNDINGS SHOW A SHARP GRADIENT IN MOISTURE ACROSS THE REGION WITH PRECIP WATER AT PIT ONLY .13 INCH TO .82 INCH AT ILN. THE HRRR ACKNOWLEDGES THIS DRY AIR OVER THE CENTRAL APPALACHIANS AND ADVECTS IT NORTHWESTWARD ACROSS THE EASTERN 2/3 OF THE FORECAST AREA THIS AFTERNOON. WILL LOWER DEWPOINTS IN THE 30S AND RAISE MAX TEMPERATURES A FEW DEGREES TO SUPPORT THE 12Z SOUNDING AT PIT. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... THE SHORT TERM FORECAST DEPENDS ON THE EVOLUTION OF THE UPPER LOW AS IT FORMS TODAY IN THE AR/MO REGION. CURRENT GFS/NAM/SREF RUNS FAIRLY AGREEABLE IN KEEPING THE LOW IN AR THROUGH SATURDAY NIGHT BEFORE DRIVING IT SLOWLY EAST ACROSS AL AND GA. MEANWHILE HIGH PRESSURE ALOFT AND AT THE SURFACE WILL EXTEND INTO THE AREA FROM THE E/NE WITH DRY AIR CONTINUING TO MOVE ACROSS THE AREA. BASED ON THIS KEPT THE FORECAST DRY THROUGH THE ENTIRE SHORT TERM PERIOD WITH FAIR SKIES EXPECTED MUCH OF THE TIME. TEMPS SHOULD REMAIN SEASONAL TO A FEW DEGREES ABOVE. && .LONG TERM /TUESDAY THROUGH THURSDAY/... ONLY DAY THAT HAS ANY CHANCE OF PRECIPITATION IS TUESDAY...AND THAT MAY NOT PAN OUT. MORE CONSISTENCY WITH MODELS MAINTAINING HIGH PRESSURE OVER THE AREA AND SHIFTING THE CUTOFF LOW EAST ACROSS THE TN VALLEY. CLOUD SHIELD WILL LIKELY REACH TO THE LOCAL AREA...BUT SHOWERS MAY NOT. WILL CONTINUE THE LOW PRECIP CHANCES...WITH NO PRECIP MENTIONED FOR WEDNESDAY AND THURSDAY. TEMPERATURES SLIGHTLY ABOVE NORMAL. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS WILL CONTINUE THROUGH TONIGHT. MOST LOCATIONS WILL ONLY SEE VARIABLE AMOUNTS OF HIGH LEVEL CLOUD COVER. EXPECT SE WINDS TO CONTINUE WITH SOME GUSTS AROUND 20 KNOTS FOR MOST LOCATIONS BY FRIDAY AFTERNOON. LAKE BREEZE POSSIBLE AT KERI...NOT AS LIKELY FOR KCLE. NO CHANGES. .OUTLOOK...NON-VFR CONDITIONS POSSIBLE BY MONDAY. && .MARINE... HIGH PRESSURE TO THE EAST OF THE LAKE WILL CONTINUE TO BLOCK THE ADVANCEMENT OF LOW PRESSURE ACROSS THE WESTERN LAKES/MIDWEST. THAT SYSTEM WILL EVENTUALLY PASS SOUTH OF LAKE ERIE...LIKELY ACROSS THE TN VALLEY EARLY NEXT WEEK. THIS WILL LEAVE HIGH PRESSURE AS THE MAIN INFLUENCE FOR LAKE ERIE. CAN EXPECT DAILY ONSHORE/LAKE BREEZE FLOW FOR MOST OF THE AFTERNOONS...THE SOUTHEAST FLOW AT NIGHT BECOMING MORE NORTHEASTERLY. BY MIDWEEK HIGH PRESSURE BUILDS OVER THE WESTERN LAKES AND THE FLOW ACROSS LAKE ERIE WILL BECOME MORE NORTHERLY...BUT STILL REMAIN LIGHT. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...TK NEAR TERM...LAPLANTE SHORT TERM...TK LONG TERM...OUDEMAN AVIATION...OUDEMAN MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
832 PM CDT SAT MAY 4 2013 .UPDATE... LATEST RADAR IMAGERY SHOWS LIGHT TO MODERATE RAIN SHIELD REMAINS ACROSS EASTERN ZONES...GENERALLY ALONG AND EAST OF A LINE FROM GALLATIN TO MANCHESTER. WEST OF THAT LINE...SCATTERED TO NUMEROUS LIGHT TO OCCASIONALLY MODERATE SHOWERS HAVE DEVELOPED WESTWARD TO NEAR A CLARKSVILLE TO PULASKI LINE. LOCATIONS REMAIN DRY TO THE WEST OF THERE...BUT LIGHT SHOWERS HAVE BEGUN SPREADING ACROSS THE TENNESSEE RIVER IN THE PAST HOUR IN ASSOCIATION WITH THE APPROACHING UPPER LOW. TEMPERATURES REMAIN UNUSUALLY COLD AND WIDELY VARIABLE AT THIS HOUR...WITH LOW 50S ON THE PLATEAU...MID TO UPPER 40S IN THE CENTRAL CWA...AND LOW 50S IN THE SOUTHWEST. HAVE MADE SEVERAL ADJUSTMENTS TO GRIDS/ZONES BASED ON LATEST OBS AND RADAR TRENDS. RAISED POPS ACROSS THE WEST WHERE LIGHT RAIN IS SPREADING EASTWARD WITH UPPER LOW...AND EXTENDED LIKELY POPS FURTHER TO THE WEST TO NEAR A CLARKSVILLE/PULASKI LINE. LATEST HRRR RUNS INDICATE CURRENT SHOWER ACTIVITY ALONG THE I-65 CORRIDOR WILL CONTINUE THIS EVENING THEN DISSIPATE OVERNIGHT AS DRIER AIR AROUND CIRCULATION OF UPPER LOW SHIFTS EASTWARD. AS THIS OCCURS...HRRR INDICATES PRECIPITATION INTENSITIES WITHIN RAIN SHIELD WILL STRENGTHEN OVERNIGHT AS SURFACE TROUGH DEEPENS AND UPPER LOW APPROACHES...LEADING TO AN INCREASE IN RAINFALL RATES IN THE FLOOD WATCH AREA. AS MENTIONED PREVIOUSLY...OF PARTICULAR CONCERN WILL BE THE SOUTHERN PLATEAU COUNTIES OF VAN BUREN...WHITE...CUMBERLAND...AND PUTNAM WHERE HIGHEST MOISTURE TRANSPORT WILL BE FOCUSED AND OROGRAPHIC LIFT IN THE 2000-3000 FT TERRAIN ENHANCES PRECIPITATION. THE CROSSVILLE ASOS HAS RECEIVED 1.31 INCHES OF RAIN AS OF 7 PM...AND ANOTHER 1 TO 1.5 INCHES IS POSSIBLE THROUGH MIDNIGHT IN THE FLOOD WATCH AREA. STORM TOTAL AMOUNTS THROUGH SUNDAY FROM 2 TO POTENTIALLY 4 INCHES STILL APPEAR REASONABLE IN EASTERN ZONES AND NO CHANGES ARE PLANNED TO THE FLOOD WATCH. SHAMBURGER && .PREV DISCUSSION... /ISSUED 646 PM CDT SAT MAY 4 2013/ UPDATE...FOR 00Z AVIATION FORECAST AVIATION... POOR FLYING CONDITIONS TO CONTINUE ACROSS THE MID STATE NEXT 24 HOURS AS UPPER LOW CURRENTLY SPINNING OVER CENTRAL ARKANSAS KEEPS A MOISTURE PLUME STREAMING INTO TENNESSEE. SHORT RANGE MODELS HAVE GOOD HANDLE ON RAINFALL WITH THE HEAVIEST TO FALL ALONG THE CENTRAL AND SOUTHERN PLATEAU COUNTIES WHERE RAINFALL WILL BECOME HEAVY OVERNIGHT. RAIN WILL CONTINUE ON SUNDAY. HAVE FORECASTED LOW IFR CEILINGS AT CROSSVILLE IN THE OVERNIGHT ALONG WITH HEAVY RAINFALL. ALSO EXPECT LOW IFR CEILINGS AT NASHVILLE BUT WITH LIGHT RANIFALL. BOYD PREV DISCUSSION... /ISSUED 613 PM CDT SAT MAY 4 2013/ MESOSCALE UPDATE... LATEST RADAR IMAGERY SHOWS MAIN AXIS OF MODERATE TO OCCASIONALLY HEAVY RAIN NOW OVER THE UPPER CUMBERLAND REGION...GENERALLY EAST OF A LINE FROM LAFAYETTE TO ALTAMONT. LATEST HRRR MODEL RUNS INDICATE THIS MAIN RAIN BAND WILL REMAIN IN PLACE FOR ANOTHER 12 TO 18 HOURS AS A SURFACE TROUGH OF LOW PRESSURE ARCING SOUTHEAST TO NORTHWEST REMAIN IN PLACE AND DEEPENS WITH THE UPPER LOW APPROACHING FROM THE WEST. OBS FROM THE CROSSVILLE ASOS INDICATE RAINFALL RATES OF 0.10 TO 0.25 INCHES PER HOUR ARE OCCURRING IN THE HEAVIEST RAIN AREAS...WITH 1 TO 2 INCHES OF RAINFALL POSSIBLE JUST THROUGH MIDNIGHT. HEAVIEST RAIN TOTALS ARE EXPECTED TO BE ON THE SOUTHERN PLATEAU ACROSS VAN BUREN...WHITE...AND CUMBERLAND COUNTIES WHERE OROGRAPHIC ENHANCEMENT FROM THE HIGHER TERRAIN SQUEEZES OUT ADDITIONAL MOISTURE. FLOODING WILL BECOME AN INCREASING CONCERN IN THIS AREA AS WE CONTINUE THROUGH THE NIGHT AND ESPECIALLY ON SUNDAY. SHAMBURGER PREV DISCUSSION... /ISSUED 340 PM CDT SAT MAY 4 2013/ DISCUSSION... PRECIP CLEARING LINE HAS BEEN MAKING A SLOW EASTWARD MOVEMENT TODAY. AT 2PM THE CLEARING LINE WAS ROUGHLY ORIENTED PARALLEL TO I-65. THIS EASTWARD PROGRESSION MAY CONTINUE FOR A FEW MORE HOURS BUT WILL LIKELY STALL BY EVENING. CURRENTLY UPPER LEVEL LOW IS LOCATED OVER NRN AR WITH A SLOW ESE MOVEMENT. 2 SFC TROUGH ARE AT WORK WITH ONE LOCATED ALONG THE MS RIVER AND ANOTHER INVERTED VERSION OF A SFC TROUGH EXTENDING NORTHWARD THROUGH GA INTO EASTERN TN. AS THE UPPER LOW CONTINUES MOVING EASTWARD...INTENSIFICATION ALONG THE STATIONARY INVERTED TROUGH IS EXPECTED. THERE MAY EVEN BE A BIT OF RETROGRADE MOVEMENT WITH THE INVERTED TROUGH AS IT STRENGTHENS. SO FAR OMEGA RETURNS HAVE BEEN MARGINALLY IMPRESSIVE OVER EASTERN PORTIONS OF THE MID STATE WHERE THE RAIN IS ONGOING. TONIGHT HOWEVER...THE STRENGTHENING INVERTED TROUGH WILL TRANSLATE INTO GREATER FORCING AND THE RAINFALL INTENSITY LEVELS WILL PICK UP. THUS...THOUGH I WILL LIKELY BE CUTTING A FEW MORE CENTRAL COUNTIES FROM THE FLOOD WATCH...THE EASTERN THIRD OF OUR CWA(PLATEAU AND ADJACENT COUNTIES) ARE STILL VERY MUCH UNDER THE GUN. MODELS ARE ALL CONVERGING ON THE HEAVY RAINFALL POTENTIAL EXTENDING NORTHWARD INTO OUR SOUTHERN PLATEAU IN PARTICULAR. ADDITIVE RAINFALL ENHANCEMENT IS CLEARLY INDICATED WITH HRRR DATA ALONG WITH A GENERAL MODEL QPF CONSENSUS. AROUND 2 TO 3 INCHES OF ADDITIONAL RAINFALL WITH LOCALIZED AMOUNTS OF 4 INCHES ARE STILL POSSIBLE ACROSS OUR SOUTHERN PLATEAU. ELSEWHERE ACROSS THE WATCH AREA...WILL LEAN TOWARD AROUND 2 INCHES OF ADDITIONAL RAINFALL BEING POSSIBLE BUT WILL REFRAIN FROM THE EXTRA LOCALIZED WORDING. CURRENT THINKING FOR THE WATCH AREA IS TO INCLUDE AREAS ALONG AND EAST OF A LINE FROM MACON COUNTY TO COFFEE COUNTY. WILL KEEP THE WATCH GOING UNTIL 7 PM SUNDAY NIGHT. ALTHOUGH THE HEAVIEST ACTIVITY WILL MOVE EAST OF OUR COUNTIES BY 18Z...ITS GOOD TO KEEP THE WATCH GOING FOR A FEW MORE HOURS AS FLOODING CAN OFTEN OCCUR HOURS AFTER THE HEAVIER RAINFALL ENDS. SHOWER ACTIVITY...THOUGH LESS INTENSE...TO PERSIST INTO SUNDAY NIGHT AS THE UPPER LOW PASSES JUST TO OUR SOUTH. SOME SUNSHINE WILL RETURN ON MONDAY ALONG WITH WARMER TEMPS. IN THE EXT FCST...UPPER LOW WILL BE FAR ENOUGH EAST AND UPPER RIDGING WILL COMMENCE BY MID WEEK. THIS WILL EQUATE TO WARMER AND DRIER CONDITIONS. IN FACT...MAY GO POP FREE TUES NT INTO WED. UPPER RIDGE WILL BEGIN TO FLATTEN BY THE END OF THE WEEK. INSTABILITY PARAMETERS INDICATE INCREASE CAPES AND LOWERING CAP STRENGTHS BEGINNING ON THU. A SFC FRONT WILL THEN MOVE CLOSER BY FRIDAY AND SATURDAY AND THIS WILL ADD TO OUR SHOWER AND TSTM CHANCES. EXT TEMPS WILL BE RUNNING ABOVE NORMAL FOR THE LAST HALF OF THE EXTENDED...THU-SAT. WONT DEVIATE MUCH FROM MEX ADVICE. && .OHX WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH THROUGH SUNDAY EVENING FOR TNZ009>011-029>034- 063>066-077>080. && $$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
646 PM CDT SAT MAY 4 2013 .UPDATE...FOR 00Z AVIATION FORECAST .AVIATION... POOR FLYING CONDITIONS TO CONTINUE ACROSS THE MID STATE NEXT 24 HOURS AS UPPER LOW CURRENTLY SPINNING OVER CENTRAL ARKANSAS KEEPS A MOISTURE PLUME STREAMING INTO TENNESSEE. SHORT RANGE MODELS HAVE GOOD HANDLE ON RAINFALL WITH THE HEAVIEST TO FALL ALONG THE CENTRAL AND SOUTHERN PLATEAU COUNTIES WHERE RAINFALL WILL BECOME HEAVY OVERNIGHT. RAIN WILL CONTINUE ON SUNDAY. HAVE FORECASTED LOW IFR CEILINGS AT CROSSVILLE IN THE OVERNIGHT ALONG WITH HEAVY RAINFALL. ALSO EXPECT LOW IFR CEILINGS AT NASHVILLE BUT WITH LIGHT RANIFALL. BOYD && .PREV DISCUSSION... /ISSUED 613 PM CDT SAT MAY 4 2013/ MESOSCALE UPDATE... LATEST RADAR IMAGERY SHOWS MAIN AXIS OF MODERATE TO OCCASIONALLY HEAVY RAIN NOW OVER THE UPPER CUMBERLAND REGION...GENERALLY EAST OF A LINE FROM LAFAYETTE TO ALTAMONT. LATEST HRRR MODEL RUNS INDICATE THIS MAIN RAIN BAND WILL REMAIN IN PLACE FOR ANOTHER 12 TO 18 HOURS AS A SURFACE TROUGH OF LOW PRESSURE ARCING SOUTHEAST TO NORTHWEST REMAIN IN PLACE AND DEEPENS WITH THE UPPER LOW APPROACHING FROM THE WEST. OBS FROM THE CROSSVILLE ASOS INDICATE RAINFALL RATES OF 0.10 TO 0.25 INCHES PER HOUR ARE OCCURRING IN THE HEAVIEST RAIN AREAS...WITH 1 TO 2 INCHES OF RAINFALL POSSIBLE JUST THROUGH MIDNIGHT. HEAVIEST RAIN TOTALS ARE EXPECTED TO BE ON THE SOUTHERN PLATEAU ACROSS VAN BUREN...WHITE...AND CUMBERLAND COUNTIES WHERE OROGRAPHIC ENHANCEMENT FROM THE HIGHER TERRAIN SQUEEZES OUT ADDITIONAL MOISTURE. FLOODING WILL BECOME AN INCREASING CONCERN IN THIS AREA AS WE CONTINUE THROUGH THE NIGHT AND ESPECIALLY ON SUNDAY. SHAMBURGER PREV DISCUSSION... /ISSUED 340 PM CDT SAT MAY 4 2013/ DISCUSSION... PRECIP CLEARING LINE HAS BEEN MAKING A SLOW EASTWARD MOVEMENT TODAY. AT 2PM THE CLEARING LINE WAS ROUGHLY ORIENTED PARALLEL TO I-65. THIS EASTWARD PROGRESSION MAY CONTINUE FOR A FEW MORE HOURS BUT WILL LIKELY STALL BY EVENING. CURRENTLY UPPER LEVEL LOW IS LOCATED OVER NRN AR WITH A SLOW ESE MOVEMENT. 2 SFC TROUGH ARE AT WORK WITH ONE LOCATED ALONG THE MS RIVER AND ANOTHER INVERTED VERSION OF A SFC TROUGH EXTENDING NORTHWARD THROUGH GA INTO EASTERN TN. AS THE UPPER LOW CONTINUES MOVING EASTWARD...INTENSIFICATION ALONG THE STATIONARY INVERTED TROUGH IS EXPECTED. THERE MAY EVEN BE A BIT OF RETROGRADE MOVEMENT WITH THE INVERTED TROUGH AS IT STRENGTHENS. SO FAR OMEGA RETURNS HAVE BEEN MARGINALLY IMPRESSIVE OVER EASTERN PORTIONS OF THE MID STATE WHERE THE RAIN IS ONGOING. TONIGHT HOWEVER...THE STRENGTHENING INVERTED TROUGH WILL TRANSLATE INTO GREATER FORCING AND THE RAINFALL INTENSITY LEVELS WILL PICK UP. THUS...THOUGH I WILL LIKELY BE CUTTING A FEW MORE CENTRAL COUNTIES FROM THE FLOOD WATCH...THE EASTERN THIRD OF OUR CWA(PLATEAU AND ADJACENT COUNTIES) ARE STILL VERY MUCH UNDER THE GUN. MODELS ARE ALL CONVERGING ON THE HEAVY RAINFALL POTENTIAL EXTENDING NORTHWARD INTO OUR SOUTHERN PLATEAU IN PARTICULAR. ADDITIVE RAINFALL ENHANCEMENT IS CLEARLY INDICATED WITH HRRR DATA ALONG WITH A GENERAL MODEL QPF CONSENSUS. AROUND 2 TO 3 INCHES OF ADDITIONAL RAINFALL WITH LOCALIZED AMOUNTS OF 4 INCHES ARE STILL POSSIBLE ACROSS OUR SOUTHERN PLATEAU. ELSEWHERE ACROSS THE WATCH AREA...WILL LEAN TOWARD AROUND 2 INCHES OF ADDITIONAL RAINFALL BEING POSSIBLE BUT WILL REFRAIN FROM THE EXTRA LOCALIZED WORDING. CURRENT THINKING FOR THE WATCH AREA IS TO INCLUDE AREAS ALONG AND EAST OF A LINE FROM MACON COUNTY TO COFFEE COUNTY. WILL KEEP THE WATCH GOING UNTIL 7 PM SUNDAY NIGHT. ALTHOUGH THE HEAVIEST ACTIVITY WILL MOVE EAST OF OUR COUNTIES BY 18Z...ITS GOOD TO KEEP THE WATCH GOING FOR A FEW MORE HOURS AS FLOODING CAN OFTEN OCCUR HOURS AFTER THE HEAVIER RAINFALL ENDS. SHOWER ACTIVITY...THOUGH LESS INTENSE...TO PERSIST INTO SUNDAY NIGHT AS THE UPPER LOW PASSES JUST TO OUR SOUTH. SOME SUNSHINE WILL RETURN ON MONDAY ALONG WITH WARMER TEMPS. IN THE EXT FCST...UPPER LOW WILL BE FAR ENOUGH EAST AND UPPER RIDGING WILL COMMENCE BY MID WEEK. THIS WILL EQUATE TO WARMER AND DRIER CONDITIONS. IN FACT...MAY GO POP FREE TUES NT INTO WED. UPPER RIDGE WILL BEGIN TO FLATTEN BY THE END OF THE WEEK. INSTABILITY PARAMETERS INDICATE INCREASE CAPES AND LOWERING CAP STRENGTHS BEGINNING ON THU. A SFC FRONT WILL THEN MOVE CLOSER BY FRIDAY AND SATURDAY AND THIS WILL ADD TO OUR SHOWER AND TSTM CHANCES. EXT TEMPS WILL BE RUNNING ABOVE NORMAL FOR THE LAST HALF OF THE EXTENDED...THU-SAT. WONT DEVIATE MUCH FROM MEX ADVICE. && .OHX WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH THROUGH SUNDAY EVENING FOR TNZ009>011-029>034- 063>066-077>080. && $$ 01
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
613 PM CDT SAT MAY 4 2013 .MESOSCALE UPDATE... LATEST RADAR IMAGERY SHOWS MAIN AXIS OF MODERATE TO OCCASIONALLY HEAVY RAIN NOW OVER THE UPPER CUMBERLAND REGION...GENERALLY EAST OF A LINE FROM LAFAYETTE TO ALTAMONT. LATEST HRRR MODEL RUNS INDICATE THIS MAIN RAIN BAND WILL REMAIN IN PLACE FOR ANOTHER 12 TO 18 HOURS AS A SURFACE TROUGH OF LOW PRESSURE ARCING SOUTHEAST TO NORTHWEST REMAIN IN PLACE AND DEEPENS WITH THE UPPER LOW APPROACHING FROM THE WEST. OBS FROM THE CROSSVILLE ASOS INDICATE RAINFALL RATES OF 0.10 TO 0.25 INCHES PER HOUR ARE OCCURRING IN THE HEAVIEST RAIN AREAS...WITH 1 TO 2 INCHES OF RAINFALL POSSIBLE JUST THROUGH MIDNIGHT. HEAVIEST RAIN TOTALS ARE EXPECTED TO BE ON THE SOUTHERN PLATEAU ACROSS VAN BUREN...WHITE...AND CUMBERLAND COUNTIES WHERE OROGRAPHIC ENHANCEMENT FROM THE HIGHER TERRAIN SQUEEZES OUT ADDITIONAL MOISTURE. FLOODING WILL BECOME AN INCREASING CONCERN IN THIS AREA AS WE CONTINUE THROUGH THE NIGHT AND ESPECIALLY ON SUNDAY. SHAMBURGER && .PREV DISCUSSION... /ISSUED 340 PM CDT SAT MAY 4 2013/ DISCUSSION... PRECIP CLEARING LINE HAS BEEN MAKING A SLOW EASTWARD MOVEMENT TODAY. AT 2PM THE CLEARING LINE WAS ROUGHLY ORIENTED PARALLEL TO I-65. THIS EASTWARD PROGRESSION MAY CONTINUE FOR A FEW MORE HOURS BUT WILL LIKELY STALL BY EVENING. CURRENTLY UPPER LEVEL LOW IS LOCATED OVER NRN AR WITH A SLOW ESE MOVEMENT. 2 SFC TROUGH ARE AT WORK WITH ONE LOCATED ALONG THE MS RIVER AND ANOTHER INVERTED VERSION OF A SFC TROUGH EXTENDING NORTHWARD THROUGH GA INTO EASTERN TN. AS THE UPPER LOW CONTINUES MOVING EASTWARD...INTENSIFICATION ALONG THE STATIONARY INVERTED TROUGH IS EXPECTED. THERE MAY EVEN BE A BIT OF RETROGRADE MOVEMENT WITH THE INVERTED TROUGH AS IT STRENGTHENS. SO FAR OMEGA RETURNS HAVE BEEN MARGINALLY IMPRESSIVE OVER EASTERN PORTIONS OF THE MID STATE WHERE THE RAIN IS ONGOING. TONIGHT HOWEVER...THE STRENGTHENING INVERTED TROUGH WILL TRANSLATE INTO GREATER FORCING AND THE RAINFALL INTENSITY LEVELS WILL PICK UP. THUS...THOUGH I WILL LIKELY BE CUTTING A FEW MORE CENTRAL COUNTIES FROM THE FLOOD WATCH...THE EASTERN THIRD OF OUR CWA(PLATEAU AND ADJACENT COUNTIES) ARE STILL VERY MUCH UNDER THE GUN. MODELS ARE ALL CONVERGING ON THE HEAVY RAINFALL POTENTIAL EXTENDING NORTHWARD INTO OUR SOUTHERN PLATEAU IN PARTICULAR. ADDITIVE RAINFALL ENHANCEMENT IS CLEARLY INDICATED WITH HRRR DATA ALONG WITH A GENERAL MODEL QPF CONSENSUS. AROUND 2 TO 3 INCHES OF ADDITIONAL RAINFALL WITH LOCALIZED AMOUNTS OF 4 INCHES ARE STILL POSSIBLE ACROSS OUR SOUTHERN PLATEAU. ELSEWHERE ACROSS THE WATCH AREA...WILL LEAN TOWARD AROUND 2 INCHES OF ADDITIONAL RAINFALL BEING POSSIBLE BUT WILL REFRAIN FROM THE EXTRA LOCALIZED WORDING. CURRENT THINKING FOR THE WATCH AREA IS TO INCLUDE AREAS ALONG AND EAST OF A LINE FROM MACON COUNTY TO COFFEE COUNTY. WILL KEEP THE WATCH GOING UNTIL 7 PM SUNDAY NIGHT. ALTHOUGH THE HEAVIEST ACTIVITY WILL MOVE EAST OF OUR COUNTIES BY 18Z...ITS GOOD TO KEEP THE WATCH GOING FOR A FEW MORE HOURS AS FLOODING CAN OFTEN OCCUR HOURS AFTER THE HEAVIER RAINFALL ENDS. SHOWER ACTIVITY...THOUGH LESS INTENSE...TO PERSIST INTO SUNDAY NIGHT AS THE UPPER LOW PASSES JUST TO OUR SOUTH. SOME SUNSHINE WILL RETURN ON MONDAY ALONG WITH WARMER TEMPS. IN THE EXT FCST...UPPER LOW WILL BE FAR ENOUGH EAST AND UPPER RIDGING WILL COMMENCE BY MID WEEK. THIS WILL EQUATE TO WARMER AND DRIER CONDITIONS. IN FACT...MAY GO POP FREE TUES NT INTO WED. UPPER RIDGE WILL BEGIN TO FLATTEN BY THE END OF THE WEEK. INSTABILITY PARAMETERS INDICATE INCREASE CAPES AND LOWERING CAP STRENGTHS BEGINNING ON THU. A SFC FRONT WILL THEN MOVE CLOSER BY FRIDAY AND SATURDAY AND THIS WILL ADD TO OUR SHOWER AND TSTM CHANCES. EXT TEMPS WILL BE RUNNING ABOVE NORMAL FOR THE LAST HALF OF THE EXTENDED...THU-SAT. WONT DEVIATE MUCH FROM MEX ADVICE. && .OHX WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH THROUGH SUNDAY EVENING FOR TNZ009>011-029>034- 063>066-077>080. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
938 AM EDT FRI MAY 3 2013 .DISCUSSION... NO CHANGES ARE NEEDED TO THE FORECAST THIS MORNING. A SE FLOW OF MOISTURE OFF THE ATLANTIC IS BRINGING BROKEN CLOUDS TO SOUTHERN AREAS...WHILE DOWNSLOPE EFFECTS ARE PROVIDING MOSTLY SUNNY SKIES IN THE CENTRAL AND SOUTHERN TN VALLEY. THE RUC AND SREF SHOW LIGHT QPF COMING INTO SOUTHERN SECTIONS LATE IN THE AFTERNOON...AND THE CURRENT FORECAST OF LOW CHANCE POPS IN THAT AREA LOOKS GOOD. TEMPS AND DEWPOINTS APPEAR TO BE IN LINE WITH OBS. && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DGS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
930 PM CDT SAT MAY 4 2013 NEW INFORMATION ADDED TO UPDATE SECTION .UPDATE... ISSUED AT 926 PM CDT SAT MAY 4 2013 NOT PLANNING ANY SIG CHGS TO THE FCST THIS EVENING. CENTRAL WI MIXED OUT THE LOW-LEVEL MOISTURE THIS AFTN...SO VERY LARGE SFC DWPT DEPRESSIONS IN THAT AREA. THAT ALSO EXTENDS INTO N-C WI...S OF REMNANTS OF BOUNDARY ACRS THAT RGN. THE AREA OF GREATEST CONCERN IS THE FAR NW PART OF THE FCST AREA. THAT AREA STILL HAS SOME SNOW/ICE ON THE GROUND...AND THE LOWEST DWPT DEPRESSIONS. BUT SFC PRESSURE GRADIENT IS A LITTLE STRONGER IN THAT AREA. AT THIS POINT...JUST HAVING MENTION OF SOME FG IN THE GRIDS/ZONES SEEMS SUFFICIENT. && .SHORT TERM...TONIGHT AND SUNDAY ISSUED AT 236 PM CDT SAT MAY 4 2013 AN UPPER LEVEL DISTURBANCE ROTATING AROUND THE UPPER LOW CAUSED SOME SHOWERS TO DEVELOP LATE THIS MORNING/EARLY THIS AFTERNOON. MOST OF THESE SHOWERS WERE NOW WEST OF WOOD AND MARATHON COUNTY. COULD NOT RULE OUT A STRAY SHOWER UNTIL 21Z...BUT WILL NOT HIGHLIGHT IN A PRE-FIRST PERIOD TO THE ZONE FORECAST TO ACCOUNT FOR THIS REMOTE POSSIBILITY. ATTENTION THEN TURNS TO THE FOG. NUMERICAL GUIDANCE NOT INDICATIVE OF DENSE FOG LATE TONIGHT OUTSIDE THE FAR NORTH. HOWEVER...DEW POINTS MAINLY IN THE 40S TO AROUND 50 THIS AFTERNOON...PARTLY CLOUDY SKIES AND LIGHT WINDS TONIGHT...AND A COLDER THAN NORMAL SOIL TEMPERATURES LEAD ME TO THINK THERE WILL BE MORE FOG/DENSE FOG AROUND TONIGHT THAN THE NUMERICAL GUIDANCE SUGGEST. WILL MENTION AREAS OF DENSE FOG ACROSS THE FAR NORTH AND AREAS OF FOG WITH LOCALLY DENSE FOG POSSIBLE ELSEWHERE. ANY FOG SHOULD BURN OFF BY MID MORNING ON SUNDAY. ANOTHER MILD DAY IS EXPECTED WITH HIGHS WELL INTO THE 60S TO LOWER 70S. A WEAK BOUNDARY IS EXPECTED TO DROP SOUTH IN NORTHERN WISCONSIN SUNDAY AFTERNOON. THIS BOUNDARY COULD TRIGGER SOME ISOLATED/SCATTERED SHOWERS GENERALLY NORTH OF A WAUSAU TO WAUSAUKEE LINE. .LONG TERM...SUNDAY NIGHT THROUGH SATURDAY ISSUED AT 236 PM CDT SAT MAY 4 2013 THE REMNANTS OF THE SYSTEM WHICH CAUSED HAVOC OVER THE MID SECTION OF THE COUNTRY THE LATER HALF OF THE PREVIOUS WORK WEEK CONTINUES TO CHURN OVER THE SOUTHEAST STATES AND SLOWLY WEAKEN THROUGH TUESDAY. ANOTHER UPPER LOW SYSTEM IS PROGGED TO DROP INTO SOUTHWEST STATES EARLY IN THE NEW WORK WEEK AS WELL. LOCALLY A RIDGE OF HIGH PRESSURE WILL EXTEND OVER THE GREAT LAKES REGION TROUGH AT LEAST MID WEEK. ABOVE NORMAL AND MAINLY DRY CONDITIONS CAN BE EXPECTED THROUGH MID WEEK. WEAK MID LEVEL CONVERGENCE OVER THE NORTHERN PLAINS AND NORTHWEST WESTERN MAY BE CLOSE ENOUGH TO PARTS OF NORTH CENTRAL AND CENTRAL WISCONSIN TO GENERATE AN ISOLATED SHOWER IN THE AFTERNOON EACH MONDAY AND TUESDAY SINCE MARGINAL INSTABILITY REMAINS IN THIS AREA. SLIGHTLY COOLER TEMPS ALOFT WERE PRODUCING TOTAL TOTALS IN THE MID TO UPPER 40S. HOWEVER SUBSIDENCE FROM THE EAST WINDS WITH THE UPPER RIDGE MAY LOWER HUMIDITY TO KEEP THE SHOWERS IN CHECK. AS A RESULT WILL KEEP THE FORECAST DRY THROUGH MID WEEK. PROGS BEGIN TO INTRODUCE A PATTERN CHANGE WITH LIFTING THE SOUTHWEST U.S. LOW INTO THE MID SECTION OF THE COUNTRY BEFORE DEVELOPING A DEEPER SHORT WAVE TROUGH THE LATER HALF OF THE WEEK. PCPN CHANCES WILL BE ON THE INCREASE OVER AT LEAST THE SOUTH HALF OF THE STATE AS THE TROUGH DRAGS A LOW PRESSURE SYSTEM OVER IOWA AND ILLINOIS WHILE HIGH PRESSURE DROPS INTO THE GREAT LAKES FROM THE NORTH. A COLDER SURGE OF AIR WITH A FROPA MAY DROP INTO THE REGION LATE SATURDAY INTO SATURDAY NIGHT. A FEW RAIN/SNOW? SHOWERS WILL BE POSSIBLE ACROSS NORTH NEXT WEEKEND. THE RIDGE OF HIGH PRESSURE WITH LIGHT WINDS AND CLEAR SKIES MAY PROVIDE A FEW NIGHTS WITH FOG. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 557 PM CDT SAT MAY 4 2013 MAIN ISSUE IS THE POTENTIAL FOR FG FORMATION TNGT. RAP VSBY FCST FOCUSES ON THE FAR N...WHERE THERE IS STILL SOME LINGERING SNOW/ICE COVER...AND HAS MVFR CONDITIONS ELSEWHERE. THAT/S SIMILAR TO WHAT/S IN THE GOING FCST...SO WL STAY THE COURSE WITH THAT FOR NOW AND SEE HOW DPWTS REACT THIS EVENING. /PARTS OF CENTRAL WI MIXED INTO DRIER AIR ALOFT THIS AFTN./. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE.........SKOWRONSKI SHORT TERM.....ECKBERG LONG TERM......TDH AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
625 PM CDT SAT MAY 4 2013 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 306 PM CDT SAT MAY 4 2013 MAIN FORECAST CONCERN IS ON FOG AND DENSE FOG POTENTIAL TONIGHT CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED UPPER LOWS OVER NORTHERN CALIFORNIA AND IN ARKANSAS...WHILE AN UPPER HIGH WAS PRESENT ACROSS MUCH OF THE GREAT LAKES. FLOWING BETWEEN THE ARKANSAS UPPER LOW AND THE GREAT LAKES UPPER HIGH WAS A SHORTWAVE OVER CENTRAL WISCONSIN. DPVA AHEAD OF THIS SHORTWAVE COMBINED WITH DAYTIME HEATING AND SOME EVAPOTRANSPIRATION HAS AIDED IN SHOWERS NORTH OF I-94. FARTHER SOUTH...SCATTERED SHOWERS ARE ALSO PRESENT ACROSS PORTIONS OF NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN...AIDED BY INSTABILITY PRODUCED BY DEWPOINTS CLIMBING INTO THE LOW 50S AND SOME COOLER TEMPS ALOFT. REGARDING TEMPERATURES... THEY VARY GREATLY ACROSS THE FORECAST AREA...FROM THE 40S IN ROCHESTER TO 60S ACROSS MUCH OF SOUTHWEST INTO CENTRAL WISCONSIN. THE WARMER TEMPERATURES ARE A RESULT OF MORE SUN AND AN EASTERLY FLOW OF WARMER AIR COMING OUT OF THE UPPER HIGH. 12Z GRB SOUNDING SHOWED 900MB TEMPS OF +14C...COMPARED TO +5C AT MPX. BOTH SOUNDINGS HAD AN INVERSION...BUT MPX WAS MUCH DEEPER AND THUS COMBINED WITH THE CLOUDS WAS HELPING TO KEEP TEMPERATURES COOLER IN SOUTHEAST MN. THE DEEPER INVERSION ALSO HAS HELPED TRAPPED PLENTY OF LOW LEVEL MOISTURE...INCLUDING THAT FROM THE MELTING SNOWPACK...WHICH RESULTED IN LOW VISIBILITIES OVER NORTHEAST IOWA...SOUTHEAST MINNESOTA AND EVEN NORTH CENTRAL WISCONSIN THIS MORNING. VERY LITTLE CHANGE IS FORECAST IN THE UPPER LEVEL PATTERN THROUGH SUNDAY...EXCEPT FOR SOME UPPER RIDGING TRYING TO BUILD WESTWARD THROUGH THE FORECAST AREA FROM THE UPPER HIGH. THIS UPPER RIDGING SHOULD HELP TO KEEP THE FORECAST AREA DRY THROUGH SUNDAY AFTER ANY SHOWERS FROM THIS AFTERNOON DISSIPATE WITH LOSS OF HEATING. THE BIG ISSUE TONIGHT IS FOG. CONTINUING SNOW MELT OVER WESTERN AND FAR NORTHERN PORTIONS OF THE AREA WILL HELP TO KEEP THE LOW LEVELS OF THE ATMOSPHERE MOIST. MEANWHILE...MODELS MAINTAIN AN INVERSION OVER THE SNOW PACK AREAS...WHICH MAKES SENSE WITH THE EASTERLY FLOW OF WARMER AIR ALOFT ABOVE A NORTH-NORTHEAST FLOW OF COOL AIR AT THE SURFACE. GIVEN THAT 1/4SM FOG FORMED THIS MORNING AND WINDS ARE GOING TO BE EVEN LIGHTER...SITUATION SEEMS VERY FAVORABLE FOR FOG AND EVEN DENSE FOG. ADDITIONALLY...SOME CLEARING COULD TRY TO WORK IN BASED ON VISIBLE SATELLITE TRENDS...MAKING FOG EVEN MORE FAVORABLE. SREF PROBABILITIES FOR VISIBILITY LESS THAN 1 MILE ARE MUCH MORE EXPANSIVE AND HIGHER TONIGHT COMPARED TO THIS MORNING...AND THE 04.00Z/06Z/12Z HIRES ARW/NMM ALL SHOW MORE FOG TOO THAN THIS MORNING. LATEST HRRR/RAP ALSO DEVELOP FOG OVER THE SNOW PACK. GIVEN THESE SIGNALS...HAVE INCREASED FOG COVERAGE AND ISSUED A DENSE FOG ADVISORY...CONFINED TO THE AREAS WITH MELTING SNOW PACK. COMBINATION OF HIGHER DEWPOINTS TONIGHT AND COME CLOUDS WILL RESULT IN A WARMER NIGHT TONIGHT. WARMER TEMPERATURES ARE ALSO ON TAP TOMORROW WITH MORE SUN LIKELY AS DRIER AIR COMING OUT OF THE UPPER HIGH ADVECTS WESTWARD. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 306 PM CDT SAT MAY 4 2013 SUNDAY NIGHT THROUGH TUESDAY...NOT MUCH TO TALK ABOUT WITH REGARDS TO THE UPPER LEVEL PATTERN. THE UPPER HIGH THAT IS OVER THE GREAT LAKES SLOWLY BREAKS DOWN IN RESPONSE TO A SHORTWAVE TROUGH TRACKING ACROSS NORTHERN ONTARIO COME MONDAY. STILL...THE FORECAST AREA JUST SITS IN A LACK OF ANY UPPER LEVEL FLOW...SPLIT BETWEEN A SOUTHERN STREAM TRACKING ACROSS THE SOUTHERN U.S. AND THE NORTHERN STREAM WELL UP IN CANADA. MEANWHILE AT THE SURFACE...HIGH PRESSURE CURRENTLY PRESENT OVER NORTHERN ONTARIO IS PROGGED TO BUILD SOUTH INTO THE AREA DURING THIS PERIOD. DRYING AIR WITH THIS HIGH PRESSURE AREA COMBINED WITH LACK OF ANY FLOW ALOFT WILL HELP TO KEEP THE FORECAST AREA DRY. MAIN CONCERN AGAIN IS FOG. SREF PROBABILITIES FOR VISIBILITY LESS THAN 1 MILE SHOOT BACK UP AGAIN SUNDAY NIGHT... CONFINED TO THE SNOW PACK AREA. ONE QUESTION WOULD BE IS HOW MUCH SNOW IS LEFT AFTER MELTING FROM THIS WEEKEND. HOWEVER...SOILS ARE LIKELY GOING TO BE MOIST...AND WITH LIGHT WINDS AND CLEARING FROM THE HIGH PRESSURE AREA BUILDING IN...RECIPE LOOKS GOOD AGAIN FOR FOG AND EVEN DENSE FOG. MAY EVEN SEE FOG AGAIN MONDAY NIGHT...DEPENDING IF THE SOIL IS STILL MOIST. REGARDING TEMPERATURES THROUGH TUESDAY...850MB TEMPS ARE PROGGED TO HOLD AROUND 8C FOR MONDAY AND THEN CLIMB TO NEAR 10C BY THE END OF THE DAY TUESDAY. THESE READINGS ARE 0.5 TO 1 STANDARD DEVIATION ABOVE NORMAL. BOTH DAYS SHOULD SEE QUITE A BIT OF SUN BEING IN PROXIMITY TO THE SURFACE HIGH...THUS THINKING MIXING TO 850MB WILL NOT BE A PROBLEM. THIS RESULTS IN HIGHS MAINLY IN THE LOW 70S ON MONDAY AND LOW TO MID 70S ON TUESDAY. DID KEEP THE ROCHESTER AREA A LITTLE COOLER ON MONDAY DUE TO WETTER SOIL. LIGHT WINDS AND DRY AIR LIKELY TO RESULT IN DECENT COOLING AT NIGHT. FOLLOWED A BLEND OF MOS GUIDANCE FOR LOWS. TUESDAY NIGHT THROUGH SATURDAY...04.12Z ECMWF/GFS/CANADIAN AND ECMWF ENSEMBLES SHOW THAT THE MORE ZONAL LOOKING NORTHERN STREAM WILL BUCKLE DURING THE EXTENDED PORTION OF THE FORECAST. FOR FRIDAY AND SATURDAY...GOOD AGREEMENT EXISTS IN FAIRLY DEEP TROUGHING OVER CENTRAL CANADA...BEGINNING TO DROP DOWN TOWARDS THE FORECAST AREA. IF THE 04.00Z/04.12Z ECMWF ARE CORRECT...WE COULD BE LOOKING AT A SIGNIFICANT COOL DOWN HEADING INTO EARLY NEXT WEEK AS 850MB TEMPS PLUMMET TO -8 TO -10C. BEFORE THAT TROUGH ARRIVES...THOUGH...A SERIES OF WEAK COLD FRONTS / SYSTEMS ARE PROGGED TO COME THROUGH THE AREA. THE FIRST MOVES THROUGH LATE WEDNESDAY. INSTABILITY BUILDING AHEAD OF THIS FRONT...AIDED BY TEMPERATURES CLIMBING AT LEAST INTO THE LOW IF NOT MID 70S...REQUIRES A CHANCE OF SHOWERS AND THUNDERSTORMS. FOR THURSDAY INTO FRIDAY...THE 04.00Z/12Z ECMWF INDICATES A SHORTWAVE TROUGH MOVING WEST TO EAST THROUGH THE AREA...WHEREAS THE GFS AND CANADIAN KEEP THIS SHORTWAVE MUCH FARTHER TO THE SOUTH. FOR NOW HAVE INCLUDED A CHANCE OF SHOWERS AND THUNDERSTORMS UNTIL MODEL CONSISTENCY BECOMES BETTER. THEN FOR SATURDAY WOULD BE THE STRONGER COLD FRONT ACCOMPANYING THE UPPER TROUGH...THUS ANOTHER CHANCE OF PRECIPITATION. TEMPERATURES LOOK TO STAY NEAR OR ABOVE NORMAL...UNTIL SATURDAY. SATURDAY COULD BE TRICKY WITH HIGHS AS IT DEPENDS ON WHEN THE FRONT COMES THROUGH. 04.12Z ECMWF IS SLOWER...WHICH WOULD SUGGEST THE BLEND OF ALL AVAILABLE GUIDANCE MIGHT BE TOO COOL. WE WILL HAVE TO WAIT AND SEE. && .AVIATION...TONIGHT AND SUNDAY 625 PM CDT SAT MAY 4 2013 CLOSED CIRCULATION WELL SOUTH OF THE AREA...CENTERED OVER NORTHERN ARKANSAS. CIRCULATION AROUND IT STILL ROTATING SOME CLOUD COVER INTO THE AREA...BUT MAINLY MID AND HIGH LEVEL. BIGGEST CONCERN TO AVIATION TONIGHT WILL BE FOG...ESPECIALLY OVER THE SNOW PACK AREAS OF SOUTHEAST MN /KRST/. HIGH DEWPOINT AIR MOVING WEST ACROSS THE SNOW COVER...AND THIS HAS MAINTAINED CLOUD COVER THROUGH THE DAY. ONCE DAYLIGHT IS LOST...ANTICIPATE FOG TO FORM. DENSE FOG IS LIKELY AND AN ADVISORY IS IN EFFECT FOR KRST. CONDITIONS SHOULD IMPROVE SUNDAY DURING THE MID TO LATE MORNING HOURS. FOR KLSE...WILL LIKELY STILL BE SOME AREAS OF FOG...BUT PERHAPS NOT AS THICK. TAFS HAVE FOLLOWED THE GENERAL TREND OF THE ONES ISSUED EARLIER TODAY. WILL MONITOR CHANGING CONDITIONS AS THE SUN SETS FOR ANY NECESSARY ADJUSTMENTS. && .HYDROLOGY... ISSUED AT 306 PM CDT SAT MAY 4 2013 AFTER SOME ISOLATED/SCATTERED RAIN SHOWERS THROUGH THIS EVENING...A FEW DAYS OF DRY WEATHER ARE EXPECTED. THESE DRY DAYS WILL BE BENEFICIAL...ALLOWING RUNOFF FROM THE RECENT RAIN AND SNOWMELT TO WORK ITS WAY THROUGH THE TRIBUTARIES INTO THE MAIN STEM OF THE MISSISSIPPI RIVER. MOST OF THE TRIBUTARIES ARE REMAINING BELOW FLOOD STAGE. MEANWHILE...ALL THE WATER EVENTUALLY LOOKS TO PUSH SOME SITES ALONG THE MISSISSIPPI RIVER RIGHT TO FLOOD STAGE. SEE THE LATEST FLOOD AND RIVER STATEMENTS FOR MORE INFORMATION. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR WIZ032-033. MN...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR MNZ079- 086>088-094-095. IA...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR IAZ008-009- 018-019. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...MW HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
255 PM CDT FRI MAY 3 2013 .SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT) ISSUED AT 255 PM CDT FRI MAY 3 2013 MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES AND POSSIBLE THUNDERSTORMS THROUGH PERIOD. LATEST WATER VAPOR SATELLITE IMAGERY SHOWS UPPER LEVEL LOW CUTTING OFF OVER THE CENTRAL PLAINS AND INDICATING GOOD FETCH OF MOISTURE LIFTING NORTHWARD INTO THE UPPER MIDWEST AND GREAT LAKES REGION. LATEST MOSAIC RADAR SHOWS RAIN ACROSS PORTIONS OF SOUTHEAST MINNESOTA AND WESTERN WISCONSIN INTO EASTERN IOWA AND NORTHERN ILLINOIS. THIS IS IN RESPONSE TO DECENT MOISTURE TRANSPORT AND CONVERGENCE IN THE 925-850MB LAYER PER 03.15Z RAP. THE 03.12Z GFS/NAM ARE IN GOOD AGREEMENT IN MOVING UPPER LEVEL CUTOFF LOW OVER THE SOUTHERN PLAINS AND SOUTHEAST UNITED STATES THROUGH SATURDAY NIGHT. THE DETERMINISTIC MODELS CONTINUE TO SHOW A SERIES OF SHORTWAVE TROUGHS WRAPPING AROUND UPPER LEVEL LOW INTO THE UPPER MIDWEST. THE 03.12Z GFS/NAM AND 03.15Z RAP INDICATE THE AREA IS ON THE NOSE OF DECENT MOISTURE TRANSPORT AND CONVERGENCE AT 925-850MB LAYER TONIGHT INTO SATURDAY MORNING. THIS WILL CONTINUE TO SPREAD RAIN/RAIN SHOWERS INTO THE FORECAST AREA THROUGH SATURDAY. ALONG WITH THE SURGE OF MOISTURE...THE 03.12Z GFS/NAM ADVECT WARMER AIR ALOFT INTO THE FORECAST AREA THIS EVENING AND INTO TONIGHT...WITH 925MB TEMPERATURES RISING TO PLUS 5 TO PLUS 13 DEGREES CELSIUS BY 12Z SATURDAY. ALL PRECIPITATION SHOULD REMAIN AS RAIN ACROSS THE FORECAST AREA. THE 03.12Z GFS/NAM INCREASE 0-6KM MOST UNSTABLE CAPE OF 300-500 J/KG ACROSS SOUTHERN HALF OF FORECAST AREA AFTER 15Z SATURDAY. CANNOT RULE OUT AN ISOLATED THUNDERSTORM ACROSS THIS AREA FROM 15Z SATURDAY TO 00Z SUNDAY. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 255 PM CDT FRI MAY 3 2013 SUNDAY...EASTERLY TO NORTHEASTERLY FLOW ALOFT DEVELOPS OVER REGION AFTER 06Z SUNDAY AND WILL ADVECT DRIER AIR INTO THE REGION. WITH 925MB TEMPERATURES AROUND PLUS 13 DEGREES CELSIUS AND PARTIAL SUNSHINE OVER FORECAST AREA...EXPECT HIGH TEMPERATURES TO WARM INTO THE 60S. MONDAY NIGHT THROUGH FRIDAY...MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES WEDNESDAY INTO FRIDAY. THE 03.00Z GFS/ECMWF/GEM ARE IN AGREEMENT IN DEVELOPING SPLIT UPPER LEVEL FLOW OVER THE CONTINENTAL UNITED STATES THROUGH PERIOD. THE MAIN DIFFERENCE IS THE 03.00Z ECMWF PUSHES A WEAK UPPER LEVEL LOW INTO THE UPPER MIDWEST WEDNESDAY INTO THURSDAY AND THE GEM/GFS CONTINUE TO SHOW RIDGING OVER THE REGION. THE 03.00Z ECMWF INDICATE WEAK MOISTURE CONVERGENCE AND LIFT IN ASSOCIATED WITH WEAK UPPER LEVEL LOW AND PRODUCES PRECIPITATION OVER THE AREA. THE 03.00Z GEFS INDICATE UPPER LEVEL RIDGING OVER THE UPPER MIDWEST AND GREAT LAKES REGION AND NO HINT OF A WEAK UPPER LEVEL LOW OVER THE AREA. CONFIDENCE IN PRECIPITATION CHANCES WEDNESDAY AND THURSDAY IS DECREASING AT THIS TIME. THE 03.00Z GEM/ECMWF/GFS ARE SUGGESTING 850MB TEMPERATURES PLUS 6 TO PLUS 10 DEGREES CELSIUS MONDAY NIGHT THROUGH FRIDAY ACROSS THE AREA. EXPECT HIGH TEMPERATURES TO CLIMBING TO AROUND 70 ACROSS FORECAST AREA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 108 PM CDT FRI MAY 3 2013 WINTRY MIX FINALLY GIVING WAY TO ALL RAIN AT THE KRST/KLSE TAF SITES AS WARMER AIR ROTATES IN FROM THE EAST/SOUTHEAST. LOOK FOR AREAS OF RAIN/RAIN SHOWERS TO CONTINUE OVERNIGHT INTO SATURDAY MORNING AS MOISTURE ROTATES AROUND LOW PRESSURE MEANDERING AROUND SOUTHERN IL/MO. MVFR/IFR CIGS EXPECTED THROUGH THE PERIOD. && .HYDROLOGY... ISSUED AT 255 PM CDT FRI MAY 3 2013 THE RECENT HEAVY SNOW AND EXPECTED RAINFALL AMOUNTS OF THREE QUARTERS OF AN INCH TO AROUND AN INCH OVER THE REGION TONIGHT INTO SATURDAY NIGHT...WILL PRODUCE RISES ALONG THE MISSISSIPPI RIVER AND AREA TRIBUTARIES THROUGH THE WEEKEND. A FEW SITES ALONG THE MISSISSIPPI RIVER ARE EXPECTED TO RISE TO ABOVE AND TO NEAR FLOOD STAGE. SOME TRIBUTARIES ARE FORECAST TO HAVE WITHIN BANK RISES. && .ARX WATCHES/WARNINGS/ADVISORIES... 255 PM CDT FRI MAY 3 2013 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DTJ LONG TERM....DTJ AVIATION.....DAS HYDROLOGY....DTJ
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
327 AM EDT SUN MAY 5 2013 .DISCUSSION... ...ROUGH SURF/HIGH RIP CURRENT RISK TODAY... CURRENTLY-TODAY...WEAK FRONTAL BOUNDARY OVER WEST CENTRAL FLORIDA IS POISED TO SLIDE ACROSS THE AREA. THERE WILL BE CONSIDERABLE LOW CLOUDS AHEAD OF AND JUST BEHIND THE BOUNDARY. BY LATE MORNING HEATING/MIXING WILL DISSIPATE MOST OF THIS CLOUDINESS. WEST/NORTHWEST FLOW WILL BE OCCASIONALLY GUSTY DURING THE DAY. MAX TEMPS WILL CONTINUE A LITTLE BELOW NORMAL IN THE UPPER 70S TO LOWER 80S. TONIGHT...WEAK RIDGING BEHIND THE FRONT WILL KEEP SKIES MOSTLY CLEAR EARLY. ANOTHER WEAK FRONTAL TROUGH WILL PUSH INTO THE PENINSULA AFTER MIDNIGHT. THE AIR MASS WILL BE QUITE DRY SO EXPECT JUST A NARROW BAND OF CLOUDINESS WITH THIS BOUNDARY. OVERNIGHT LOWS WILL BE A LITTLE BELOW NORMAL IN THE UPPER 50S TO LOWER 60S. MON-MON NIGHT...LARGE EXPANSIVE UPPER LOW OVER THE TENNESSEE VALLEY IS FORECAST TO SLOWLY MOVE EAST INTO THE CAROLINAS THROUGH THE END OF THIS PERIOD. ONLY WEAK ENERGY ALOFT ASSOCIATED WITH THIS FEATURE WILL TRAVERSE EAST CENTRAL FLORIDA. A WEAK FRONTAL TROUGH WILL MOVE ACROSS THE COVERAGE WARNING AREA AND PROVIDE A SMALL THREAT FOR SHOWERS...MAINLY SOUTH OF THE I-4 CORRIDOR. YET ANOTHER FEATURE IS FORECAST TO DROP INTO NORTH-CENTRAL FLORIDA OVERNIGHT. WILL KEEP POPS AT 20 PERCENT OR LESS. WESTERLY WINDS INCREASING TO 10-15 MPH IN THE AFTERNOON. HIGHS IN THE UPPER 70S TO AROUND 80 DEGREES NORTH OF THE I-4 CORRIDOR WITH LOWER 80S FURTHER SOUTHWARD. LOWS MAINLY IN THE UPPER 50S...EXCEPT AROUND 60 DEGREES TO LOWER 60S ACROSS THE SPACE/TREASURE COASTS AND ORLANDO METRO. TUE-TUE NIGHT...THE PREVIOUSLY MENTIONED UPPER LOW WILL GRADUALLY WEAKEN AS IT BEGINS TO MOVE UP THE MID ATLANTIC COAST. CLOSER TO HOME THE NEXT WEAK FRONTAL TROUGH WILL MOVE FROM NORTH-CENTRAL FLORIDA THROUGH EAST CENTRAL FLORIDA DURING THE DAY. AGAIN ISOLATED SHOWERS WILL BE POSSIBLE THROUGH THE DAY BUT EXPECT PRECIPITATION TO BE LIGHT AS MOISTURE VALUES ARE POOR. MAINLY WESTERLY WINDS AGAIN INCREASING TO 10-15 MPH IN THE AFTERNOON. HIGHS NEAR 80 DEGREES TO LOWER 80S MOST LOCATIONS...EXCEPT A FEW MIDDLE 80S POSSIBLE ACROSS OKEECHOBEE COUNTY AND SOUTHERN OSCEOLA COUNTY. OVERNIGHT LOWS ONCE AGAIN IN THE MIDDLE TO UPPER 50S WITH A FEW LOWER 60S POSSIBLE ALONG THE TREASURE COAST AND ORLANDO METRO. WED-SAT...THE UPPER LOW CONTINUES TO WEAKEN AS IT SLOWLY MOVES UP THE ATLANTIC SEABOARD...FINALLY OPENING UP INTO A TROUGH AND MOVING INTO THE NORTH ATLANTIC DURING THE DAY ON FRI. MAINLY ZONAL WINDS ALOFT OVER THE AREA WITH ONLY A FEW SUBTLE IMPULSES EMBEDDED WITHIN. SLIGHT SHORTWAVE RIDGING BEGINS TO INCREASE OVER THE REGION ON SAT. THE LOCAL SURFACE PRESSURE GRADIENT REMAINS RATHER WEAK AS HIGH PRESSURE OVER THE AREA INITIALLY MOVES INTO THE WESTERN ATLANTIC ON THU WITH RIDGING EXTENDING ACROSS THE CENTRAL PENINSULA INTO THE WEEKEND. LIGHT WESTERLY SURFACE FLOW ON WED WILL GIVE WAY TO AFTERNOON SEA BREEZES EACH DAY THU-SAT. ENOUGH MOISTURE MAY CREEP BACK INTO THE AREA ON SAT FOR A FEW LATE DAY STORMS ACROSS THE INTERIOR. BELOW NORMAL MAX/MIN TEMPERATURES WILL CONTINUE INTO WED BEFORE A GRADUAL WARMING TREND COMMENCES THU LASTING INTO THE WEEKEND. && .AVIATION... MVFR STRATUS HAS BEEN ADVANCING SLOWLY EAST ACROSS THE PENINSULA AHEAD OF AND JUST BEHIND WEAK FRONTAL BOUNDARY. SOME IFR CEILINGS MAY OCCUR KISM-KMCO-KDAB NORTHWARD IN THE PRE DAWN HOURS. THE MVFR STRATUS SHOULD ARRIVE A LITTLE LATER KMLB-KVRB-KFPR-KSUA...JUST BEFORE SUNRISE...AND SHOULD GRADUALLY BREAK UP BY LATE MORNING. VFR EXPECTED BY LATE MORNING/EARLY AFTERNOON...BUT WEST/NORTHWEST WINDS WILL GUST TO NEAR 20 KNOTS AT MOST TERMINALS. && .MARINE... CURRENTLY-TONIGHT...THE NORTHERN OFFSHORE LEG STILL HAS SOUTHEAST WINDS AROUND 20 KNOTS BUT THE GFS AND LATEST RAP SHOW SURFACE LOW OVER NORTHEAST FLORIDA MOVING FARTHER AWAY AND WINDS WEAKENING BY FORECAST ISSUANCE TIME. WEST/NORTHWEST WINDS 10 TO 15 KNOTS EXPECTED MOST OF THE DAY AND INTO TONIGHT. SEAS ARE STILL ELEVATED ESPECIALLY IN THE NORTH DUE TO EAST/NORTHEAST SWELLS. THIS WILL LIKELY MAKE INLETS HAZARDOUS DURING THE OUTGOING TIDE THIS MORNING. THEREFORE...WILL CARRY A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS THIS MORNING OVER ALL THE WATERS. MON-MON NIGHT...WEAK HIGH PRESSURE WILL BUILD INTO THE AREA BEHIND THE MOST RECENT WEAK FRONTAL TROUGH. WESTERLY WINDS THROUGH THIS TIME WITH SPEEDS NEAR 10 KTS NEAR SHORE AND OCCASIONALLY 10-15 KTS OFFSHORE. INCREASING LARGE EASTERLY SWELL WILL KEEP SEAS 3-5 FT NEAR SHORE AND 5-6 FT OFFSHORE. CAUTIONARY STATEMENTS WILL BE NECESSARY FOR OFFSHORE LEGS DUE TO THE SWELL. TUE-THU...ANOTHER WEAK TROUGH PASSES THROUGH THE AREA ON TUE BEFORE HIGH PRESSURE BUILDS BACK INTO THE REGION EMERGING INTO THE WESTERN ATLANTIC ON THU. MAINLY A WESTERLY COMPONENT OF WIND BUT MAY SEE WINDS BACK TO THE E/ESE ALONG THE COAST BY WED/THU WITH EAST COAST SEA BREEZE FORMATION. WIND SPEEDS 10-12 KTS NEAR SHORE WITH PERIODS AROUND 15 KTS OFFSHORE. SEAS TO SUBSIDE DURING THIS TIME WITH INITIAL 3-5 FT SEAS FALLING BACK 3 FT OR LESS BY EARLY THU. && .FIRE WEATHER... TODAY...A FEW HOURS OF RH 30 TO 35 PERCENT SHOULD OCCUR OVER THE INTERIOR NORTH THIS AFTERNOON. WEST WINDS NEAR 15 MPH WILL BE GUSTY TO AROUND 20 MPH AT TIMES. HOWEVER...THE ERC VALUES ARE TOO LOW AFTER RECENT RAINS FOR RED FLAG CRITERIA TO OCCUR. MON-THU...GUIDANCE CONTINUES TO SHOW MIN RH VALUES DROPPING INTO THE M-U30S OVER THE INTERIOR EACH AFTERNOON. WINDS SHOULD NOT BE A HUGE CONCERN...AND FORTUNATELY...ERC VALUES HAVE DROPPED SIGNIFICANTLY FROM LAST WEEK`S RAINFALL. && .PRELIMINARY POINT TEMPS/POPS... DAB 78 60 76 58 / 20 10 10 10 MCO 81 60 81 58 / 10 10 20 10 MLB 79 62 80 60 / 10 10 20 10 VRB 80 61 82 59 / 10 10 20 10 LEE 80 59 79 58 / 10 10 10 10 SFB 80 60 80 59 / 10 10 20 10 ORL 80 62 81 61 / 10 10 20 10 FPR 79 58 81 60 / 10 10 20 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 12 NOON TODAY FOR ALL OF THE COASTAL WATERS. && $$ SHORT TERM...LASCODY LONG TERM....SEDLOCK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
404 AM EDT SUN MAY 5 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 402 AM EDT SUN MAY 5 2013 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG STRETCHING FM SE CANADA INTO THE UPR GRT LKS TO THE N OF CLOSED LO OVER THE SRN MS RIVER VALLEY THAT WAS RESPONSIBLE FOR THE WINTER WX THE PAST COUPLE OF DAYS. THE 00Z GRB RAOB AND ESPECIALLY THE APX RAOB SHOW A VERY DRY AIRMASS UNDER THIS RDG...WITH THE 00Z H85 DEWPT DEPRESSION AS HI AS 24C/PWAT JUST 0.24 INCH OR 49 PCT OF NORMAL AT APX. BUT THERE IS STILL A RIBBON OF DEEPER MSTR SOME -SHRA EXTENDING NNWWD FM THE CLOSED LO TO THE S INTO MN/ADJOINING ONTARIO. THE 00Z INL RAOB SHOWS A NEARLY SATURATED PROFILE AND 00Z PWAT OF 0.83 INCH...188 PCT OF NORMAL. ALTHOUGH THERE ARE SOME HI CLDS OVER THE E...THAT AREA IS DOMINATED BY THE DRY AIRMASS SHOWN ON THE APX RAOB. WITH H85 TEMPS UP TO 10C...MAX TEMPS YDAY REACHED THE 70S OVER THE SCENTRAL AND ERN CWA WHERE THE DRY AIR ALLOWED FOR QUITE A BIT OF SUNSHINE AND LAKE COOLING WAS ABSENT IN THE NLY FLOW S OF HI PRES CENTERED OVER NW ONTARIO. ALTHOUGH THE DRY AIR ALF HAS PUSHED INTO THE WRN CWA PER THE LATEST RUC ANALYSIS SDNGS...ENUF LLVL MSTR LINGERS THERE UNDER SHARP INVRN AT H9 TO SUPPORT LO CLDS/FOG OVER THE WRN CWA FM THE KEWEENAW THRU GOGEBIC COUNTY. SINCE THE 00Z YPL RAOB SHOWS SOME MSTR BTWN H9-825 EVEN CLOSE TO THE ONTARIO HI CENTER...THERE IS QUITE A BIT OF LO CLD EXTENDING WELL N OF LK SUP TO THE HI PRES RDG AXIS. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LO CLD TRENDS/IMPACT ON TEMPS. POTENTIAL FOR LOW RH OVER THE E/IMPACT ON FIRE WX CONCERNS THIS AFTN IS THE FOCUS THERE. TODAY...UPR RDG AXIS/MID LVL DRY AIR WL REMAIN DOMINANT. ALTHOUGH SFC HI PRES OVER NW ONTARIO IS PROGGED TO DRIFT SLOWLY S TOWARD LK SUP...THE NNW FLOW IN ADVANCE OF THIS HI...ALBEIT LGT...WL LIKELY ACT TO HOLD LO CLDS IN PLACE OVER MUCH OF THE NW HALF OF THE CWA DESPITE THE ONSET OF DIURNAL HEATING THAT WOULD NORMALLY MIX OUT THIS LLVL MSTR. IN FACT...COOL ADVECTION OFF THE CHILLY WATERS OF LK SUP WL TEND TO OFFSET THE DIURNAL HEATING AND MAINTAIN A LLVL INVRN/POTENTIAL FOR MORE PERSISTENT LO CLDS IN THIS AREA AS HI TEMPS HOLD IN THE 40S NEAR THE SHORE. OVER THE E HALF OF THE CWA...A LGT S FLOW WL PREVAIL ARND SFC HI PRES OVER SE ONTARIO. ALTHOUGH THERE MAY BE MODERATION NEAR THE BAY OF GREEN BAY/ LK MI WITH A LK BREEZE...H85 TEMPS NEAR 10C/MIXING TO H8-85 ON NAM/ GFS FCST SDNGS WITH A GOOD DEAL OF SUNSHINE SUPPORT HI TEMPS TOPPING OUT IN THE 70S AWAY FM THE LK COOLING. WITH SFC DEWPTS MIXING OUT TOWARD 35 OVER THE INTERIOR...MIN RH WL LIKELY FALL AS LO AS ABOUT 25 PCT. FORTUNATELY...THE WINDS WL BE LGT...SO NO FIRE WX HEADLINES ARE NECESSARY. TONIGHT...WITH HI PRES FCST TO SHIFT OVHD AND LGT WINDS...EXPECT TEMPS TO DIP INTO THE 30S...FALLING MOST SHARPLY OVER THE E AND SCENTRAL...WHERE MUCH DRIER AIR /PWAT NEAR 0.5 INCH/ WL LINGER. SINCE MORE LLVL MSTR WL BE LINGERNING OVER THE W/NCENTRAL... RETAINED A MENTION OF FOG IN THIS AREA OVERNGT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 402 AM EDT SUN MAY 5 2013 WITH THE CUTOFF LOW SITUATED OVER THE SOUTHEAST CONUS AND THE NORTHERN JET STREAM WELL TO THE NORTH OF THE AREA IN CANADA...A QUIET START TO THE WORK WEEK IS EXPECTED WITH ABOVE NORMAL TEMPERATURES OVER MUCH OF THE AREA. MONDAY AND TUESDAY WILL BE DOMINATED BY HIGH PRESSURE AT THE SURFACE. EXPECT MOSTLY CLEAR SKIES FOR MUCH OF THIS PERIOD...BUT THERE COULD BE SOME HIGH BASED DIURNAL CU DEVELOPING OVER THE INTERIOR WEST DUE TO A POCKET OF 800-750MB MOISTURE. A FEW MODELS HINT AT SOME SHOWER DEVELOPMENT...BUT WITH THE HIGH BASES AND LIMITED MOISTURE KEEPING MLCAPE VALUES BELOW 150 J/KG...THINK IT WILL JUST BE CU. THE SUNSHINE WILL ALLOW FOR AMPLE MIXING...TO 800-775MB...AND LEAD TO HIGHS IN THE LOWER 70S AWAY FROM THE GREAT LAKES. LAKE BREEZES ON BOTH DAYS WILL KEEP TEMPERATURES COOLER NEAR THE GREAT LAKES. DID TRY TO MIX OUT DEWPOINTS A LITTLE MORE THAN THE MODELS HAVE INDICATED BASED OFF WHAT OCCURRED YESTERDAY. FORTUNATELY...WITH LIGHT WINDS UNDER THE HIGH...IT WILL LIMIT FIRE WX CONCERNS OVER THE SOUTH CENTRAL AND EAST EVEN THOUGH FFMC VALUES ARE ON THE INCREASE AND ARE OR BECOMING HIGH. PATCHY GROUND FOG IS POSSIBLE OVER THE KEWEENAW AND INTERIOR WEST MONDAY NIGHT WITH THE CLEAR SKIES AND LOW LEVEL COOLING BY LINGERING SNOW COVER. FARTHER EAST...DRIER AIR IN PLACE WILL LIMIT THE FOG POTENTIAL. OVER THE GREAT LAKES...MODELS ARE HINTING AT FOG DEVELOPMENT WITH THE LIGHT WINDS ON MONDAY. BUT DEWPOINTS AREN/T EXTREMELY HIGH AND WITH DRY AIR ALOFT IT WON/T GET MUCH HELP FROM THE LAND. WITH THAT BEING SAID...IF IT DOES DEVELOP...THE LIGHT WINDS WOULD LEAD TO SLOW MOVEMENT AND IT LINGERING INTO WEDNESDAY. COULD SEE SOME PATCHY GROUND FOG OVER THE FAR WEST LATE TUESDAY NIGHT...BUT CONFIDENCE IS TOO LOW TO ADD AT THIS POINT. THE HIGH PRESSURE WILL BEGIN TO GIVE WAY ON WEDNESDAY...AS AN UPPER TROUGH OVER THE WEST COAST SLIDES INTO THE PLAINS AND A SHORTWAVE SLIDES THROUGH THE NORTHERN STREAM AND PRODUCES A SURFACE LOW THAT MOVES INTO NORTHWEST QUEBEC ON WEDNESDAY. A COLD FRONT ASSOCIATED WITH THIS LOW WILL TRY TO DROP THROUGH THE AREA ON WEDNESDAY AFTERNOON AND NIGHT. WITH THE UPPER TROUGH MOVING INTO THE PLAINS...IT MAY PROVIDE ENOUGH MOISTURE TO PRODUCE SOME SHOWERS. BUT THE MODELS DIFFER ON THE NORTHEASTWARD EXTENT OF THE MOISTURE FROM THE UPPER TROUGH. THE 12Z ECMWF/GEM KEEP THE MOISTURE FARTHER TO THE WEST...WHILE THE 18Z GFS PULLS IT INTO THE UPPER GREAT LAKES. LATEST 00Z GFS/GEM RUNS HAVE TRENDED TOWARDS THE ECMWF IDEA. BASED ON THE EXISTING DRY AIR MASS AND LIMITED MOISTURE RETURN...WOULD TEND TO SIDE WITH THE DRIER IDEA AND WILL ONLY HAVE SLIGHTS OR LOW CHANCE POPS FOR THE PASSAGE OF THE FRONT. BEHIND THE FRONT...ANOTHER NORTHERN STREAM SHORTWAVE MAY AFFECT THE AREA ON FRIDAY NIGHT INTO SATURDAY AND BRING ANOTHER POTENTIAL FOR RAIN. BUT AGAIN...MOISTURE LOOKS TO BE THE CONCERN FOR THAT PERIOD UNLESS THE LOW MOVING THROUGH THE LOWER GREAT LAKES MOVES FARTHER TO THE NORTH. TEMPERATURES WED INTO SATURDAY LOOK TO BE COOLER THAN THE FIRST PART OF THE WORK WEEK...BUT STILL NORMAL OR VERY SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 123 AM EDT SUN MAY 5 2013 EXPECT LOW CLOUDS AND FOG AT ALL TAF SITES THROUGH AROUND DAYBREAK TODAY WITH LIFR/IFR FLIGHT CATEGORY. LIGHT WINDS WILL BE THE RULE AS A LARGE AREA OF HIGH PRESSURE SINKS IN FROM CENTRAL ONTARIO...AND RESIDES OVER THE AREA BY MID AFTERNOON. SKIES SHOULD SCATTER OUT AT ALL THE TAF SITES BY THE AFTN. LIGHT WIND REGIME WILL LEAD TO LAKE BREEZES AT ALL SITES. LIGHT WINDS AND CONTINUAL LOW-LEVEL MOISTURE ALLOWS POTENTIAL FOR LGT FOG AGAIN LATER TONIGHT INTO EARLY MONDAY MORNING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 402 AM EDT SUN MAY 5 2013 A QUIET PERIOD OF WEATHER IS EXPECTED THROUGH THE PERIOD...WITH THE WINDS LIKELY STAYING BELOW 25KTS. HIGH PRESSURE THAT HAS SETUP OVER THE AREA WILL REMAIN THROUGH THE FIRST PART OF THE WORK WEEK AND LEAD TO LIGHT WINDS. THEN...A COLD FRONT DROPPING SOUTHEAST ACROSS THE UPPER GREAT LAKES ON WEDNESDAY INTO WEDNESDAY NIGHT WILL BRING A WIND SHIFT BUT ONLY 10-20KT WINDS. WEAK HIGH PRESSURE WILL MOVE OVER NORTHERN LAKE SUPERIOR FOR THURSDAY INTO THURSDAY NIGHT AND DIMINISH THE WINDS. && .HYDROLOGY... ISSUED AT 402 AM EDT SUN MAY 5 2013 HYDROLOGY CONCERNS WILL REMAIN OVER THE COMING DAYS...UNTIL THE REMAINING SNOW PACK MELTS OVER THE NORTHWESTERN THIRD OF UPPER MICHIGAN. VISIBLE SATELLITE AND MODIS IMAGERY TODAY STILL SHOWS SNOW REMAINING IN THE HIGHER TERRAIN LOCATIONS OF THE HURON MOUNTAINS AND THE KEWEENAW PENINSULA. FARTHER WEST...THE 10 PLUS INCHES OF WET SNOW WILL ALSO HELP KEEP THE POTENTIAL OF RISING RIVER LEVELS IN PLACE. DID SEE RISES AT SOME OF THE SITES OVER THE WEST /RKLM4 AND ESPECIALLY TRRM4/ WITH THE WARMER TEMPERATURES YESTERDAY AND WOULD EXPECT THAT TO CONTINUE TODAY INTO THE FIRST PART OF THE WORK WEEK. THE STURGEON RIVER AT ALSTON AND CHASSELL...THE MICHIGAMME RIVER AROUND WITCH LAKE...AND THE PAINT RIVER NEAR CRYSTAL FALLS WILL REMAIN CONCERNS INTO AT LEAST EARLY NEXT WEEK...AND IN THE CASE OF THE MICHIGAMME RIVER PERHAPS WELL INTO THE COMING WEEK. BUT OTHERWISE RIVER LEVELS CONTINUE TO COME DOWN DESPITE SOME RECENT HEAVY PRECIP THAT IMPACTED MAINLY THE W HALF OF UPR MI. FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND ADVISORIES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...JLA MARINE...SRF HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1158 PM CDT SAT MAY 4 2013 .UPDATE... ISSUED AT 1150 PM CDT SAT MAY 4 2013 UPDATED TO INCLUDE 06Z AVIATION DISCUSSION BELOW. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 341 PM CDT SAT MAY 4 2013 WARMER WEATHER WILL GRADUALLY MOVE IN ACROSS THE REGION OVER THE NEXT FEW DAYS AND CONDITIONS BEGIN TO DRY OUT. BY THE MIDDLE OF THE WEEK A SERIES OF UPPER LEVEL DISTURBANCES WILL BRING RETURNED CHANCES FOR SHOWERS AND THUNDERSTORMS...ALONG WITH COOLER TEMPERATURES. EARLY AFTERNOON NORTH AMERICAN WATER VAPOR IMAGERY TOGETHER WITH 500MB HEIGHTS AND WINDS SHOWED THE CUTOFF LOW SPINNING OVER THE OZARK MOUNTAINS...WITH A RIDGE LOCATED ALONG EACH COAST. AT THE SURFACE A LOOSE PRESSURE GRADIENT WAS DRAPED ACROSS THE UPPER MIDWEST BETWEEN A 1028 HIGH IN NORTH DAKOTA...AND A 1013 LOW IN SOUTHERN MISSOURI WITH NORTHERLY WINDS OVER MINNESOTA AND WISCONSIN. THE EXPANSIVE CLOUD SHIELD FROM THE AFOREMENTIONED UPPER LEVEL LOW WAS BEGINNING TO SHOW SOME HOLES IN WISCONSIN...AND THIS ALLOWED TEMPERATURES TO CLIMB INTO THE MID 70S WHERE THERE WAS NO SNOWPACK. HOWEVER...FARTHER WEST TEMPERATURES WERE ONLY IN THE 40S WHERE THE DEEP SNOWPACK LINGERED FROM THE PREVIOUS WINTER STORM. FARTHER WEST STILL IN NEAR THE SD/MN BORDER TEMPERATURES WERE ONLY IN THE UPPER 30S ALONG WITH THICKER CLOUDS AND LIGHT DRIZZLE ASSOCIATED WITH THE DEFORMATION ZONE FROM THE DECAYING CYCLONE TO THE SOUTH. TONIGHT FORECAST MODELS SHOW THE PRESSURE GRADIENT RELAXING...RESULTING IN DECREASING WINDS. AS THE CLEARING TREND PROGRESSES WESTWARD OVERNIGHT AREAS OF FOG ARE EXPECTED TO DEVELOP ALONG THE MN/WI BORDER...WITH THE HIGHEST POTENTIAL FOR DENSE FOG ALONG AND EAST OF A LINE FROM ALBERT LEA UP THROUGH RED WING AND RICE LAKE WI. FORECAST SOUNDINGS SHOW A DEEP INVERSION WITH LOW LEVEL MOISTURE...BUT FEEL THE WINDS ARE OVERDONE...SO THE FOG POTENTIAL IS HIGHER THAN INDICATED. MEMBER 2 OF THE HOPWRF HAS A BETTER HANDLE OF THE CLEARING TREND...AND SHOWS FOG DEVELOPMENT IN THIS REGION AROUND 08Z. THE 16Z RUN OF THE HRRR SHOWS A SIMILAR TREND. THEREFORE HAVE ISSUED A DENSE FOG ADVISORY OVERNIGHT. HIGH TEMPERATURES ON SUNDAY WILL DEPEND ON HOW QUICKLY WE CAN MIX OUT THE FOG. THIS WILL BE DIFFICULT TO DO WITH LIGHT WINDS AND WEAK MECHANICAL MIXING...SO WILL HAVE TO DEPEND ON THE EARLY MAY SUN. TEMPERATURES ACROSS THE WEST WILL BE 15 TO 20 DEGREES COOLER THAN SNOW FREE AREAS OF WISCONSIN DUE TO CLOUD COVER. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 341 PM CDT SAT MAY 4 2013 SUNDAY NIGHT WILL HAVE ANOTHER FAVORABLE SETUP FOR FOG DEVELOPMENT. ON MONDAY SURFACE TEMPERATURES WILL REBOUND TO NEAR 70 DEGREES...WITH WARMER TEMPS ON TUESDAY AS SOUTHERLY FLOW INCREASES AHEAD OF THE NEXT WEAK UPPER LEVEL WAVE. USED A MIX DOWN TOOL TO FORECAST HIGH TEMPERATURES...AND INCREASED THEM A FEW DEGREES ABOVE THE PREVIOUS FORECAST...ESPECIALLY IN FAR WESTERN MINNESOTA. THIS WAVE IS FORECAST TO BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS WEDNESDAY. THE SEVERE WEATHER THREAT IS VERY LOW...WITH SMALL DEEP LAYER SHEAR AND ONLY 500J/KG OF MLCAPE. UNSETTLED WEATHER WILL CONTINUE THROUGH THE END OF THE WEEK. LOW POPS AND SLIGHTLY COOLER TEMPERATURES WILL BE FOCUSED ALONG A WARM FRONT THAT IS FORECAST TO STALL OUT ACROSS THE REGION...AS PERIODIC SHORTWAVES MOVING ACROSS THE UPPER MIDWEST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1150 PM CDT SAT MAY 4 2013 VERY LITTLE ADVECTIVE FLOW WILL OCCUR ACROSS THE AREA THROUGH THE PERIOD... WITH JUST SOME SLIGHT INCREASE IN HEIGHTS AND DRYING OF THE BOUNDARY LAYER INDICATED. WE SHOULD SEE A BIT MORE BREAKS IN CLOUD COVER TODAY AS THE AIRMASS CONTINUES TO MODERATE... BUT STILL PLENTY OF MVFR AND SOME IFR CEILINGS WILL BE FOUND FOR AT LEAST PART OF THE DAY. VISIBILITIES ARE A TOUGH CALL OVERNIGHT INTO EARLY SUNDAY MORNING... WITH A GOOD POTENTIAL FOR RADIATION FOG IF ANY HOLES IN THE CLOUD COVER DEVELOP... WHICH LOOKS LIKE A POSSIBILITY OVER EASTERN SITES. ON THE FLIP SIDE... WESTERN SITES WILL SEE FOG DEVELOP MORE FROM THE TOP DOWN AS THE STRATUS DECK LOWERS. WHATEVER LOWS VISIBILITIES DO OCCUR SHOULD MANAGE TO MIX OUT DURING THE 12-14Z TIME FRAME. KMSP... VERY LOW CONFIDENCE IN THE FORECAST SPECIFICS... PARTICULARLY WITH REGARD TO VISIBILITIES OVERNIGHT AND HOW QUICKLY CEILINGS WILL IMPROVE ON SUNDAY. COULD EASILY SEE SOME IMPROVEMENT IN CEILINGS DURING THE FIRST FEW HOURS OF THE FORECAST WITH MINIMAL LOW CLOUDS JUST OFF TO THE SOUTHEAST OF THE AREA... BUT REMAINED PESSIMISTIC AT THIS POINT. IF THE LOW CLOUDS DO CLEAR FOR A TIME OVERNIGHT THEN VISIBILITIES COULD GET A BIT WORSE THAN INDICATED. OTHERWISE... A GENERAL IMPROVEMENT SHOULD OCCUR SUNDAY WITH THE BOUNDARY LAYER DRYING OUT A BIT MORE AND THE AREA PROBABLY BREAKING INTO SOME A DECENT AMOUNT OF SUNSHINE BY EARLY AFTERNOON. /OUTLOOK FOR KMSP/ MONDAY...MVFR CEILINGS POSSIBLE EARLY. LIGHT AND VARIABLE WINDS. MONDAY NIGHT AND TUESDAY...VFR CONDITIONS EXPECTED. LIGHT AND VARIABLE WINDS. TUESDAY NIGHT...MVFR CEILINGS AND VISIBILITIES POSSIBLE LATE WITH A CHANCE OF SHRA/TSRA. SOUTH WINDS 5 TO 10 KT. WEDNESDAY...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A CHANCE OF SHRA/TSRA. SOUTHEAST WINDS 5 TO 15 KT BECOMING EAST. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...DENSE FOG ADVISORY UNTIL 10 AM CDT SUNDAY FOR MNZ077-078-082>085- 091>093. WI...DENSE FOG ADVISORY UNTIL 10 AM CDT SUNDAY FOR WIZ015-016-023>028. && $$ UPDATE... SHORT TERM... LONG TERM...JRB AVIATION...
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1150 PM CDT SAT MAY 4 2013 .AVIATION... 06Z TAFS FOR KOMA...KLNK...AND KOFK. NOT MUCH CHANGE FROM PREVIOUS THINKING ON TAFS. CEILINGS ARE ON THE EDGE OF IFR/MVFR BUT EXPECTED TO SWING TO IFR AND STAY THERE. KOMA IS AT SOME RISK FOR A SCATTERED SHOWER OR PATCHY DRIZZLE...BUT DID NOT INCLUDE MENTION FOR NOW AS COVERAGE IS NOT GREAT AS SHOWERS MOVE ACROSS IOWA TOWARD THE MISSOURI RIVER. SOME CHANCE FOR PATCHY DRIZZLE TO PASS OVER KOFK/KLNK...BUT RISK SEEMS TOO LOW TO INCLUDE MENTION AT THIS TIME. DID INCLUDE VISIBILITY RESTRICTION TO MVFR FOR SOME TIME TONIGHT AT ALL SITES AS WINDS DECREASE BELOW 10KT AND TEMPERATURE/DEWPOINT SPREADS DECREASE. CEILINGS SHOULD IMPROVE GRADUALLY ON SUNDAY AFTERNOON...WITH VFR CONDITIONS EXPECTED FROM LATE AFTERNOON THROUGH THE EVENING. MAYES && .PREV DISCUSSION... /ISSUED 633 PM CDT SAT MAY 4 2013/ DISCUSSION... HAVE MADE SEVERAL CHANGES TO THE OVERNIGHT FORECAST TO REFLECT ONGOING TRENDS. TEMPERATURES ARE ALREADY IN THE LOW 40S...AND THINK WE WILL SHED AT LEAST A COUPLE OF DEGREES YET TONIGHT. HAVE REDUCED MIN TEMPS IN MOST LOCATIONS OVERNIGHT...ESPECIALLY IN THE WEST/NORTHWEST CWA WHERE TEMPS ARE COOLEST. INCREASED SKY COVERAGE TO 100 PERCENT EVERYWHERE THROUGH THE NIGHT...AS WE WILL BE LOCKED IN STRATUS THROUGH THE REMAINDER OF THE NIGHT AS LOWER CEILINGS INVADE FROM THE EAST. AS FAR AS PRECIPITATION...THOUGHT THE 18Z NAM/12Z 4KM WRF/LATEST FEW RUNS OF RAP HAD A VERY GOOD HANDLE ON THE CURRENT PRECIP DISTRIBUTION...WITH A NARROW BAND OF RAIN IN NORTHEAST NEB AND A MORE ROBUST AREA OF SHOWERS IN EAST CENTRAL IA. THOSE MODELS ERODE THE PRECIPITATION COVERAGE IN IA AS IT SLIDES WESTWARD THROUGH THE NIGHT...LEAVING JUST A FEW SHOWERS BY THE TIME IT REACHES WESTERN IA LATER TONIGHT. HAVE KEPT MOST OF THE CWA FREE OF POPS OVERNIGHT...WITH A PATCHY DRIZZLE MENTION UNDER WEAK LIFT AND ABUNDANT LOW-LEVEL MOISTURE. DID HOLD ONTO A CHANCE POP IN THE NORTHWEST CWA EARLY THIS EVENING...AS THE BAND OF SCATTERED COVERAGE MOVES ACROSS...AS WELL AS A CHANCE IN THE EAST TONIGHT AS THE DISSIPATING AREAS OF SHOWERS REACH WESTERN IA. MAYES PREV DISCUSSION... /ISSUED 249 PM CDT SAT MAY 4 2013/ DISCUSSION... LARGE CLOSED UPPER LOW CONTINUES TO SLOWLY SPIN ACROSS NORTHWESTERN ARKANSAS...WITH MOISTURE CONTINUING TO MOVE FROM EAST TO WEST THROUGH THE FORECAST AREA. FIRST WAVE MOVED IN LATE LAST NIGHT THROUGH THIS MORNING...WHICH BROUGHT WIDESPREAD PRECIPITATION TO THE FORECAST AREA...WHICH CONTINUES THIS AFTERNOON ALONG AND NORTH OF I80...WHICH HAS MOSTLY BEEN RAIN ALTHOUGH A FEW SNOW FLAKES WERE NOTED FROM TIME TO TIME. THIS FIRST BATCH OF VERY LIGHT PRECIP WILL CONTINUE TO PUSH WEST NORTHWEST THROUGH THE NORTHERN CWA EARLY THIS EVENING. MEANWHILE...THE NEXT BATCH OF SIMILAR PRECIPITATION IS CURRENTLY MOVING THROUGH THE MID MISSISSIPPI RIVER VALLEY AND SHOULD BEGIN TO MOVE INTO OUR AREA BY VERY LATE THIS EVENING AND AFTER MIDNIGHT. THERE WILL BE A DRY PERIOD IN BETWEEN THE FIRST AND SECOND WAVES...AND ITS ENTIRELY POSSIBLE THAT PARTS OF SOUTHEAST NEBRASKA COULD REMAIN DRY OVERNIGHT...BUT CLOUDY. AS THE UPPER LOW CONTINUES TO DRIFT SLOWLY EAST SOUTHEAST THROUGH THE DAY SUNDAY...OUR REGION IS LEFT IN A COL AREA WITH LINGERING TRAPPED MOISTURE...WITH SCATTERED SHOWERS IN THE MORNING...WITH DIMINISHING COVERAGE IN THE AFTERNOON...AND SHOULD BE OVER BY SUNDAY EVENING AS WEAK RIDGING BUILDS IN ALOFT. MONDAY MORNING WILL PROBABLY BE DRY...BUT LEFT IN A SLIGHT CHANCE OF SHOWERS MONDAY AFTERNOON AS LAPSE RATES STEEPEN ALTHOUGH CYCLONIC FORCING BY THAT TIME IS ALMOST NON EXIST. FOR THE EXTENDED FORECAST...THE UPPER CLOSED LOW THAT EXISTS ACROSS THE WEST COAST WILL CONTINUE TO DEEPEN AND MAY EVEN RETROGRADE THROUGH MONDAY. MEANWHILE...THE FIRST PIECE OF THIS SYSTEM MOVING INTO THE CALIFORNIA BAJA REGION TODAY APPEARS TO BE MOVING THROUGH THE PLAINS BY TUESDAY/WEDNESDAY WHICH WILL BRING MORE SHOWERS AND PROBABLY THUNDERSTORMS AS INSTABILITY INCREASES... ALTHOUGH SIGNIFICANT LOW LEVEL MOISTURE IS NOT EXPECTED. MEANWHILE...THE UPPER CLOSED LOW MOVES INTO THE CENTRAL ROCKIES AND BEGINS EJECTING SMALL WAVES INTO ONTO THE PLAINS THROUGH THE REMAINDER OF THE WEEK WHICH WILL BRING DAILY CHANCES FOR RAIN. AGAIN...NOT THAT IT WILL BE A CONTINUOUSLY RAINY PERIOD...BUT IT SHOULD DEFINITELY BE A MORE ACTIVE PERIOD. ALSO DURING THIS TIME...A SUBTLE COOL FRONT APPEARS TO BE SETTLING SOUTHWARD THROUGH THE AREA...TRANSITIONING WINDS FROM SOUTH EARLY IN THE PERIOD TO EAST NORTHEAST BY FRIDAY AND SATURDAY. DEWALD && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ 99/99
AREA FORECAST DISCUSSION
NWS RALEIGH NC
315 AM EDT SUN MAY 5 2013 .SYNOPSIS... COOL HIGH PRESSURE WILL EXTEND ALONG THE NORTHEAST AND MID ATLANTIC COAST THROUGH MONDAY. A STRONG UPPER LOW WILL TRACK SLOWLY EASTWARD ACROSS THE DEEP SOUTH AND CAROLINAS THROUGH TUESDAY. && .NEAR TERM /THROUGH MONDAY NIGHT/... AS OF 300 AM SUNDAY... FOR TODAY: RAIN CHANCES WILL SLOWLY INCREASE FROM SW TO NE LATER TODAY... HOWEVER IT LOOKS LIKE THE HEAVIER RAIN IS LIKELY TO HOLD OFF UNTIL LATE. THE UPPER LOW IS CURRENTLY SPINNING NEAR MEMPHIS... WHILE NC REMAINS BENEATH A MID LEVEL COL AREA BORDERED BY THE PERSISTENT BLOCKING HIGH OVER THE ERN GREAT LAKES... BROAD WEAK LOW PRESSURE OUT OVER THE ATLANTIC... AND THE POTENT VORTEX OVER THE LOWER MISS VALLEY. STRONG MOISTURE TRANSPORT CONTINUES TO DRIVE UP OVER GA/SC INTO THE SRN APPALACHIANS WITH A 45 KT SOUTHEASTERLY LOW LEVEL JET ORTHOGONAL TO THE SLOPES OVER SW NC... LEADING TO MAXIMUM POTENTIAL TERRAIN UPGLIDE HERE AND A HIGH THREAT OF HEAVY RAIN AND FLOODING ISSUES TO OUR WEST TODAY. ADDING TO THIS LOW-LEVEL-ROOTED MECHANICAL LIFT IS STRONG UPPER DIVERGENCE WHICH WILL PEAK OVER WRN NC TODAY... ALTHOUGH THE SLOW MOVEMENT AND THE START OF GRADUAL WEAKENING OF THIS VORTEX WILL MINIMIZE MID LEVEL DPVA AND HEIGHT FALLS. SO WHILE SOME OF THIS SHIELD OF HEAVIER RAIN MAY WORK INTO THE FAR SWRN CWA THIS AFTERNOON... GIVEN THE FOCUS OF STRONGER LIFT AND MOISTURE FLUX LARGELY OVER WRN NC... EXPECT MORE IN THE WAY OF VERY PATCHY LIGHT RAIN AND DRIZZLE OVER MUCH OF CENTRAL NC THROUGH TODAY. THIS IS FURTHER SUPPORTED BY MODEL TRENDS SHOWING A SLOWING OF THE NE PROGRESS OF THE HEAVY RAIN SHIELD TODAY... AS WELL AS THE LATEST RAP AND CONVECTION-ALLOWING WRF RUNS. WILL LOWER POPS AND QPF AND DELAY THE ARRIVAL OF HIGHER CHANCES UNTIL LATE TODAY. THICKNESSES ABOUT 20-25 METER BELOW NORMAL COMBINED WITH THE BRISK ENE WINDS AND CONSIDERABLE CLOUD COVER SUPPORT COOL HIGHS OF 58-68. FOR TONIGHT: WE SHOULD FINALLY SEE THE MORE WIDESPREAD RAIN WORK INTO CENTRAL NC FROM THE SW. THE VORTEX TO OUR SW WILL BEGIN TO SLOWLY FILL AS IT WOBBLES ACROSS NRN AL TO NEAR CHATTANOOGA TONIGHT. AS IT APPROACHES... THE OCCLUDED SURFACE FRONT WILL PIVOT NE INTO SW NC ACROSS SC... WHILE THE INTENSE PLUME OF ATLANTIC MOISTURE (WITH PRECIP WATER OVER 150 PERCENT OF NORMAL) STREAMING OVER SC INTO WRN NC GRADUALLY TRANSLATES TO THE NNE. EXPECT A SLOW BUT STEADY INCREASE IN POPS FROM VERY LATE AFTERNOON THROUGH TONIGHT IN CENTRAL NC FROM SW TO NE... TRENDING UP TO CATEGORICAL ACROSS THE SOUTH AND WEST WITH LIKELY POPS IN THE NE. TOUGH CALL ON AMOUNTS THROUGH TONIGHT... CONSIDERING THAT THE MID LEVEL VORTEX WILL BE WEAKENING AND THUS THE DYNAMIC FORCING WILL BE ON THE DECREASE... PLUS THE NORTHWARD SHIFT OF THE SOUTHEASTERLY LOW LEVEL JET INTO NW NC AND SW VA WILL ACCORDINGLY PLACE THE BEST LOW LEVEL CONVERGENCE AND MOISTURE TRANSPORT JUST WEST OF THE FORECAST AREA. WILL FORECAST AMOUNTS UP TO A HALF INCH OVER THE FAR SRN AND FAR WRN CWA INCLUDING LAURINBURG INTO SOUTHERN PINES AND THE TRIAD TO THE SW... WHILE AREAS TO THE NORTH AND EAST SHOULD SEE MUCH LOWER AMOUNTS... GENERALLY A TENTH INCH OR LESS THROUGH TONIGHT AS WE SIMPLY WON`T SEE QUITE THE FORCING FOR ASCENT NOR HIGHER PW FLUX IN THE NE CWA OVERNIGHT. THE CLOUDS AND WINDS SHOULD LIMIT COOLING AND LOWER THE DIURNAL TEMP SPREAD... THUS HAVE NUDGED UP LOWS SLIGHTLY TO 54-60. FOR MONDAY/MONDAY NIGHT: THE MID LEVEL VORTEX IS EXPECTED TO REMAIN POTENT BUT STEADILY WEAKEN AS IT MEANDERS AROUND NE AL MONDAY THEN EASES INTO EAST CENTRAL GA MONDAY NIGHT AS LOBES OF VORTICITY ROTATE AROUND IT AND DRIVE ITS MOVEMENT. MODELS DIFFER ON THE EVOLUTION OF SURFACE FEATURES BUT IT APPEARS MOST LIKELY THAT THE PRIMARY LOW WILL WEAK OVER TN WHILE A SECONDARY TRIPLE-POINT LOW FORMS OVER THE CENTRAL NC/SC BORDER AREA... NEAR THE CROOK OF A MID LEVEL DRY SLOT PUNCHING INTO SC. IF THIS LOW WANDERS UP TOWARD CLT AS MOST OPERATIONAL MODELS SUGGEST... THE MID LEVEL DRY SLOT SHOULD SHIFT INTO FAR SRN NC WHILE THE BEST LOW LEVEL MOISTURE FEED AND UPPER DIVERGENCE (AND HENCE THE GREATEST ASCENT AND LOW LEVEL MOISTURE TRANSPORT) SHIFT INTO EAST-CENTRAL/NE/NORTH-CENTRAL NC MONDAY... AND EVENTUALLY UP INTO VA MONDAY NIGHT. THIS SUPPORTS THE GENERAL TREND OF EARLIER FORECAST OF SHIFTING THE CATEGORICAL POPS NORTHWARD THROUGH NC DURING THIS PERIOD. INSTABILITY REMAINS MARGINAL BUT DOES INCREASE ACROSS THE SOUTH MONDAY/MONDAY NIGHT WITH THE ARRIVAL OF THE DRY SLOT AND RISING MID LEVEL LAPSE RATES TO OVER 6.75 C/KM... AND THE NAM/GFS TAKE MLCAPE NEAR 1000 J/KG MONDAY AFTERNOON. WILL NEED TO RETAIN A MENTION OF AT LEAST ISOLATED STORMS... MAINLY SOUTH OF HIGHWAY 64 AND MAINLY IN THE AFTERNOON/EVENING. THE WIND PROFILE IS NOT TEXTBOOK BUT 0-6KM SHEAR DOES REACH 30-40 KTS WITH A CURVED 0-3 KM HODOGRAPH AND 0-1 KM SHEAR OF 20-25 KTS... SO WE COULD SEE A STRONG STORM OR TWO. ADDITIONAL RAINFALL AMOUNTS COULD APPROACH AN INCH ESPECIALLY IN THE NORTHERN HALF ACCOMPANYING THE AXIS OF MORE STEADY RAIN. THE DIURNAL SPREAD SHOULD AGAIN BE MUCH LOWER THAN USUAL... ALTHOUGH A FEW ANTICIPATED BREAKS IN THE CLOUDS IN THE SOUTH MONDAY AFTERNOON SHOULD CAUSE A SPIKE IN TEMPS. HIGHS FROM 61 NW TO 72 SE. LOWS 53 SW TO 59 NE. -GIH && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 315 AM SUNDAY... TUESDAY... THE UPPER LOW OVER THE SAVANNAH RIVER BASIN WILL LIFT VERY SLOWLY NORTHEAST ACROSS THE CAROLINAS TUESDAY. HEAVIER RAIN ASSOCIATED WITH THE WARM CONVEYOR BELT AND DEEP MOIST AXIS WILL SHIFT NORTH ACROSS VA WITH THE OCCLUDED FRONT...AS A DRY SLOT WORKS ITS WAY AROUND THE EAST SIDE OF THE UPPER LOW. COOLING ALOFT AND STEEPENING MID LEVEL LAPSE RATES (TO AROUND 7 C/KM) SHOULD STILL SUPPORT AT LEAST SCATTERED SHOWERS AND STORMS...PARTICULARLY OVER THE COASTAL PLAIN WHERE HEIGHT FALLS ALOFT AND LOW LEVEL CONVERGENCE WILL BE MAXIMIZED AHEAD OF THE UPPER LOW AND ASSOCIATED BAGGY SURFACE LOW. WHILE FAIRLY WIDESPREAD CLOUD COVER MAY INHIBIT HEATING...STRONG DEEP LAYER SHEAR AROUND 40KT ON THE EASTERN PERIPHERY OF THE UPPER LOW COULD STILL SUPPORT SOME STORM ORGANIZATION AND ENHANCE THE THREAT OF HAIL IF INSTABILITY CAN DEVELOP...MAINLY OVER THE NORTHERN COASTAL PLAIN. THE THREAT SEVERE WEATHER APPEARS TO BE LOW...HOWEVER. SOME BREAKS IN CLOUD COVER APPEAR MORE LIKELY OVER THE EAST TUESDAY...THOUGH GUIDANCE STILL ONLY INDICATES HIGHS AROUND 70 OVER THE COASTAL PLAIN. OVER THE WEST...DEEPER MOISTURE WRAPPED AROUND THE NORTHWEST SIDE OF THE UPPER LOW WILL MAINTAIN MOSTLY CLOUDY SKIES AND MAY KEEP TEMPS FROM RISING OUT OF THE LOWER 60S. TUESDAY NIGHT AND WEDNESDAY... THE UPPER LOW WILL MOVE OVERHEAD TUESDAY NIGHT AND OFF THE VA TIDEWATER REGION DURING THE DAY WEDNESDAY. FORCING FOR ASCENT WILL BECOME LESS FAVORABLE BEHIND THE UPPER LOW AS THE DEEP LAYER FLOW EXHIBITS MORE BACKING AND SUBSIDENCE BEGINS TO SET IN. SOME SHOWERS ARE POSSIBLE IN THE WRAP AROUND MOISTURE LIKELY TO ENCOMPASS VA WEDNESDAY...SOME OF WHICH MAY LINGER OF DRIFT SOUTH INTO THE NORTHERN PORTION OF THE CWA. THERMODYNAMIC PROFILES SUGGEST SOME WEAK INSTABILITY AND A FEW STORMS WILL BE POSSIBLE...THOUGH AGAIN THE THREAT OF SEVERE IS LOW. LOWS IN THE MID 50S WEDNESDAY MORNING SHOULD REBOUND INTO THE LOW TO MID 70S AREAWIDE BY WEDNESDAY AFTERNOON. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... AS OF 315 AM SUNDAY... HEIGHTS WILL CONTINUE TO SLOWLY RISE THURSDAY THROUGH FRIDAY IN THE WAKE OF THE DEPARTING UPPER LOW AND AHEAD OF SOUTHERN STREAM ENERGY MOVING OUT OF THE SOUTHWESTERN US. WITH SHORTWAVE RIDGING ALOFT OVERHEAD...DRY CONDITIONS AREA EXPECTED WITH TEMPS MODERATING INTO THE UPPER 70S AND LOWER 80S. MEDIUM RANGE MODELS THEN SHOW THE POTENTIAL FOR THE SPLIT FLOW PATTERN TO AMPLIFY NEXT WEEKEND...WITH A CUT OFF LOW OVER THE SOUTHWESTERN US AND TROUGHING FROM THE NORTH CENTRAL US TO THE EAST COAST. A COLD FRONT OVER THE MIDWEST STATES FRIDAY SHOULD EVENTUALLY PUSH EAST ACROSS THE MOUNTAINS BY SUNDAY...THOUGH THERE IS QUITE A BIT OF DISAGREEMENT BETWEEN THE ECMWF AND GFS ON THE EVOLUTION OF ENERGY OVER THE CENTRAL US AND THE PROGRESSION OF THE FRONT. PREFER TO MAINTAIN THE CHANCE POPS CURRENTLY IN THE FORECAST FOR SATURDAY AND FAVOR A SOLUTION IN BETWEEN THE FASTER ECMWF AND SLOWER GFS. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 1240 AM SUNDAY... BRISK AND GUSTY SURFACE WINDS FROM THE ENE (FROM 060-080 DEGREES) WILL PERSIST THROUGH TODAY/TONIGHT... AND THIS FLOW OF MOIST ATLANTIC AIR INTO NC WILL MAKE SUB-VFR CONDITIONS DOMINANT OVER CENTRAL NC TAF SITES. CLOUDS BASED AT ONE TO THREE THOUSAND FT AGL HAVE VARIED FROM SCATTERED TO BROKEN OVER THE LAST SEVERAL HOURS (TOPPED BY BROKEN VFR CLOUDS BASED FOUR THOUSAND TO TWELVE THOUSAND FT AGL)... MAKING IT DIFFICULT TO PINPOINT EXACTLY WHEN AND WHERE PERIODIC MVFR CIGS WILL PREVAIL. WITH LOWER-THAN-USUAL CONFIDENCE... EXPECT MAINLY VFR CIGS THROUGH 09Z-10Z THIS MORNING... FOLLOWED BY MVFR TO IFR CIGS AFTER 10Z. A FEW LIGHT SPRINKLES OR DRIZZLE ARE POSSIBLE THIS MORNING THROUGH MID AFTERNOON... BUT VSBYS SHOULD REMAIN MOSTLY VFR AND THE HEAVIEST RAINFALL WILL HOLD WEST OF A LINE FROM MT AIRY TO SALISBURY TO CLT. THE MVFR/IFR CIGS SHOULD RISE TO VFR AFTER 16Z-18Z THIS MORNING. MORE SUBSTANTIAL RAIN AND SUB-VFR VSBYS/CIGS WILL MOVE IN SLOWLY FROM THE SW TOWARD THE NE THIS AFTERNOON/ EVENING... REACHING INT/GSO/FAY AFTER 21Z... BUT NOT EXPECTED TO REACH RDU/RWI UNTIL NEAR OR AFTER 06Z TONIGHT. SUSTAINED WINDS OF 10-16 KTS GUSTING TO AROUND 20 KTS WILL CONTINUE THROUGH THE FORECAST PERIOD. LOOKING BEYOND 06Z TONIGHT: GOOD CHANCE OF CONTINUED DOMINATION OF SUB-VFR CONDITIONS WITH PERIODS OF RAIN THROUGH AT LEAST TUESDAY AS AN UPPER LEVEL LOW SLOWLY CROSSES THE REGION. BRISK ENE SURFACE WINDS WILL PERSIST THROUGH MONDAY BEFORE WEAKENING MONDAY NIGHT. SHALLOW IFR FOG IS POSSIBLE TUESDAY NIGHT/WEDNESDAY MORNING... AND AGAIN THURSDAY MORNING. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...SMITH LONG TERM...SMITH AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 AM EDT SUN MAY 5 2013 .SYNOPSIS... COOL HIGH PRESSURE WILL EXTEND ALONG THE NORTHEAST AND MID ATLANTIC COAST THROUGH MONDAY. A STRONG UPPER LOW WILL TRACK SLOWLY EASTWARD ACROSS THE DEEP SOUTH AND CAROLINAS THROUGH TUESDAY. && .NEAR TERM /THROUGH MONDAY NIGHT/... AS OF 300 AM SUNDAY... FOR TODAY: RAIN CHANCES WILL SLOWLY INCREASE FROM SW TO NE LATER TODAY... HOWEVER IT LOOKS LIKE THE HEAVIER RAIN IS LIKELY TO HOLD OFF UNTIL LATE. THE UPPER LOW IS CURRENTLY SPINNING NEAR MEMPHIS... WHILE NC REMAINS BENEATH A MID LEVEL COL AREA BORDERED BY THE PERSISTENT BLOCKING HIGH OVER THE ERN GREAT LAKES... BROAD WEAK LOW PRESSURE OUT OVER THE ATLANTIC... AND THE POTENT VORTEX OVER THE LOWER MISS VALLEY. STRONG MOISTURE TRANSPORT CONTINUES TO DRIVE UP OVER GA/SC INTO THE SRN APPALACHIANS WITH A 45 KT SOUTHEASTERLY LOW LEVEL JET ORTHOGONAL TO THE SLOPES OVER SW NC... LEADING TO MAXIMUM POTENTIAL TERRAIN UPGLIDE HERE AND A HIGH THREAT OF HEAVY RAIN AND FLOODING ISSUES TO OUR WEST TODAY. ADDING TO THIS LOW-LEVEL-ROOTED MECHANICAL LIFT IS STRONG UPPER DIVERGENCE WHICH WILL PEAK OVER WRN NC TODAY... ALTHOUGH THE SLOW MOVEMENT AND THE START OF GRADUAL WEAKENING OF THIS VORTEX WILL MINIMIZE MID LEVEL DPVA AND HEIGHT FALLS. SO WHILE SOME OF THIS SHIELD OF HEAVIER RAIN MAY WORK INTO THE FAR SWRN CWA THIS AFTERNOON... GIVEN THE FOCUS OF STRONGER LIFT AND MOISTURE FLUX LARGELY OVER WRN NC... EXPECT MORE IN THE WAY OF VERY PATCHY LIGHT RAIN AND DRIZZLE OVER MUCH OF CENTRAL NC THROUGH TODAY. THIS IS FURTHER SUPPORTED BY MODEL TRENDS SHOWING A SLOWING OF THE NE PROGRESS OF THE HEAVY RAIN SHIELD TODAY... AS WELL AS THE LATEST RAP AND CONVECTION-ALLOWING WRF RUNS. WILL LOWER POPS AND QPF AND DELAY THE ARRIVAL OF HIGHER CHANCES UNTIL LATE TODAY. THICKNESSES ABOUT 20-25 METER BELOW NORMAL COMBINED WITH THE BRISK ENE WINDS AND CONSIDERABLE CLOUD COVER SUPPORT COOL HIGHS OF 58-68. FOR TONIGHT: WE SHOULD FINALLY SEE THE MORE WIDESPREAD RAIN WORK INTO CENTRAL NC FROM THE SW. THE VORTEX TO OUR SW WILL BEGIN TO SLOWLY FILL AS IT WOBBLES ACROSS NRN AL TO NEAR CHATTANOOGA TONIGHT. AS IT APPROACHES... THE OCCLUDED SURFACE FRONT WILL PIVOT NE INTO SW NC ACROSS SC... WHILE THE INTENSE PLUME OF ATLANTIC MOISTURE (WITH PRECIP WATER OVER 150 PERCENT OF NORMAL) STREAMING OVER SC INTO WRN NC GRADUALLY TRANSLATES TO THE NNE. EXPECT A SLOW BUT STEADY INCREASE IN POPS FROM VERY LATE AFTERNOON THROUGH TONIGHT IN CENTRAL NC FROM SW TO NE... TRENDING UP TO CATEGORICAL ACROSS THE SOUTH AND WEST WITH LIKELY POPS IN THE NE. TOUGH CALL ON AMOUNTS THROUGH TONIGHT... CONSIDERING THAT THE MID LEVEL VORTEX WILL BE WEAKENING AND THUS THE DYNAMIC FORCING WILL BE ON THE DECREASE... PLUS THE NORTHWARD SHIFT OF THE SOUTHEASTERLY LOW LEVEL JET INTO NW NC AND SW VA WILL ACCORDINGLY PLACE THE BEST LOW LEVEL CONVERGENCE AND MOISTURE TRANSPORT JUST WEST OF THE FORECAST AREA. WILL FORECAST AMOUNTS UP TO A HALF INCH OVER THE FAR SRN AND FAR WRN CWA INCLUDING LAURINBURG INTO SOUTHERN PINES AND THE TRIAD TO THE SW... WHILE AREAS TO THE NORTH AND EAST SHOULD SEE MUCH LOWER AMOUNTS... GENERALLY A TENTH INCH OR LESS THROUGH TONIGHT AS WE SIMPLY WON`T SEE QUITE THE FORCING FOR ASCENT NOR HIGHER PW FLUX IN THE NE CWA OVERNIGHT. THE CLOUDS AND WINDS SHOULD LIMIT COOLING AND LOWER THE DIURNAL TEMP SPREAD... THUS HAVE NUDGED UP LOWS SLIGHTLY TO 54-60. FOR MONDAY/MONDAY NIGHT: THE MID LEVEL VORTEX IS EXPECTED TO REMAIN POTENT BUT STEADILY WEAKEN AS IT MEANDERS AROUND NE AL MONDAY THEN EASES INTO EAST CENTRAL GA MONDAY NIGHT AS LOBES OF VORTICITY ROTATE AROUND IT AND DRIVE ITS MOVEMENT. MODELS DIFFER ON THE EVOLUTION OF SURFACE FEATURES BUT IT APPEARS MOST LIKELY THAT THE PRIMARY LOW WILL WEAK OVER TN WHILE A SECONDARY TRIPLE-POINT LOW FORMS OVER THE CENTRAL NC/SC BORDER AREA... NEAR THE CROOK OF A MID LEVEL DRY SLOT PUNCHING INTO SC. IF THIS LOW WANDERS UP TOWARD CLT AS MOST OPERATIONAL MODELS SUGGEST... THE MID LEVEL DRY SLOT SHOULD SHIFT INTO FAR SRN NC WHILE THE BEST LOW LEVEL MOISTURE FEED AND UPPER DIVERGENCE (AND HENCE THE GREATEST ASCENT AND LOW LEVEL MOISTURE TRANSPORT) SHIFT INTO EAST-CENTRAL/NE/NORTH-CENTRAL NC MONDAY... AND EVENTUALLY UP INTO VA MONDAY NIGHT. THIS SUPPORTS THE GENERAL TREND OF EARLIER FORECAST OF SHIFTING THE CATEGORICAL POPS NORTHWARD THROUGH NC DURING THIS PERIOD. INSTABILITY REMAINS MARGINAL BUT DOES INCREASE ACROSS THE SOUTH MONDAY/MONDAY NIGHT WITH THE ARRIVAL OF THE DRY SLOT AND RISING MID LEVEL LAPSE RATES TO OVER 6.75 C/KM... AND THE NAM/GFS TAKE MLCAPE NEAR 1000 J/KG MONDAY AFTERNOON. WILL NEED TO RETAIN A MENTION OF AT LEAST ISOLATED STORMS... MAINLY SOUTH OF HIGHWAY 64 AND MAINLY IN THE AFTERNOON/EVENING. THE WIND PROFILE IS NOT TEXTBOOK BUT 0-6KM SHEAR DOES REACH 30-40 KTS WITH A CURVED 0-3 KM HODOGRAPH AND 0-1 KM SHEAR OF 20-25 KTS... SO WE COULD SEE A STRONG STORM OR TWO. ADDITIONAL RAINFALL AMOUNTS COULD APPROACH AN INCH ESPECIALLY IN THE NORTHERN HALF ACCOMPANYING THE AXIS OF MORE STEADY RAIN. THE DIURNAL SPREAD SHOULD AGAIN BE MUCH LOWER THAN USUAL... ALTHOUGH A FEW ANTICIPATED BREAKS IN THE CLOUDS IN THE SOUTH MONDAY AFTERNOON SHOULD CAUSE A SPIKE IN TEMPS. HIGHS FROM 61 NW TO 72 SE. LOWS 53 SW TO 59 NE. -GIH && .SHORT TERM / /... AS OF 245 PM SATURDAY... TO BE UPDATED. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 245 PM SATURDAY... TUESDAY...THE UPPER LOW MOVING ACROSS SOUTH CAROLINA SHOULD START TO LIFT NORTHEAST TUESDAY NIGHT BASED ON THE LATEST GUIDANCE. THE NAM IS FARTHER WEST WITH THE TRACK OF THE UPPER LOW...AND WITH THE GFS TRENDING TOWARD THE ECMWF...WILL LEAN TOWARD THE GFS FOR THIS FORECAST. WILL NOTE THAT THE NAM AND THE CANADIAN ARE FAIRLY SIMILAR...SO CONFIDENCE IS ONLY MODEST. AS THE LEFT EXIT REGION OF A 60-KNOT 500MB JET MOVES NORTHEAST ALONG THE COAST TUESDAY...THIS SHOULD SUPPORT INCREASED DIVERGENCE ALOFT RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA OVER THE NORTHEAST PIEDMONT AND THE NORTHERN COASTAL PLAIN...WHERE A LOW-LEVEL CONVERGENT ZONE MAY EXIST AND WHERE STRONG 850MB LIFT IS FORECAST BY THE GFS...ALONG WITH BETTER 700-500MB FRONTOGENESIS COMPARED TO THE REST OF CENTRAL NORTH CAROLINA. MOISTURE IS DEEPEST TO THE NORTHEAST AS WELL...AND AS SUCH WILL CONTINUE THE FORECAST OF THE HIGHEST CHANCES FOR SHOWERS... LOW-END CATEGORICAL...MAINLY ALONG AND NORTH OF A LINE FROM ABOUT PERSON COUNTY TO WILSON WHERE THE GFS FORECASTS AN 850MB THETA-E RIDGE. ANTICIPATE THE HEAVIEST RAIN DURING THE DAY TO OCCUR THERE. ELSEWHERE...WITH THE STEEP LAPSE RATES UNDER COLD TEMPERATURES ALOFT...AND LAPSE RATES ARE FORECAST BY THE GFS TO APPROACH 7C/KM IN PARTS OF CENTRAL NORTH CAROLINA TUESDAY AFTERNOON...ANTICIPATE SCATTERED-TO-NUMEROUS SHOWERS AND ISOLATED-TO-SCATTERED THUNDERSTORMS. SURFACE-BASED CAPE IS FORECAST BY THE GFS TO BE BETWEEN 500 AND 750J/KG TUESDAY AFTERNOON...BUT DOWNDRAFT CAPE IS WEAK...SO THE POTENTIAL FOR SEVERE WEATHER SHOULD BE LIMITED. -10C TO -30C CAPE IS MAXIMIZED BY THE GFS IN A CORRIDOR FROM ABOUT KRWI TO KRDU TO KAFP TUESDAY AFTERNOON...SO IF THERE ARE ENOUGH BREAKS FOR A STRONG STORM OR TWO WITH SMALL HAIL...PERFECT PROGGING THE GFS IT WOULD BE IN THAT LOCATION. IN A NORTHEAST FLOW WITH SOME GUSTS AND LOWER CLOUDS THE TRIAD MAY STRUGGLE TO GET TO 60 TUESDAY...WITH HIGHS OF 65 TO 70 FOR MUCH OF THE REST OF THE AREA. TUESDAY NIGHT...NUMEROUS SHOWERS MAY CONTINUE IN THE EVENING ESPECIALLY TOWARD THE VIRGINIA BORDER...WITH SCATTERED SHOWERS ELSEWHERE BEFORE BUFR SOUNDINGS FROM THE GFS SHOW THE LAYER FROM 850MB TO 700MB STARTING TO WARM AFTER 03Z. SUFFICIENT LOW-LEVEL MOISTURE AND LIFT MAY EXIST FOR SCATTERED SHOWERS TO PERSIST OVERNIGHT ESPECIALLY ALONG AND NORTH OF ABOUT U.S. 64. MAINTAINED A SLIGHT CHANCE OF A SHOWER OVERNIGHT IN THE SOUTHWEST PIEDMONT... THROUGH THE SANDHILLS AND THE SOUTHERN COASTAL PLAIN...BUT A LARGE PART OF THE OVERNIGHT MAY END UP DRY THERE AS THE UPPER LOW MOVES NORTH AND SOME SUBSIDENCE STARTS TO CREEP IN. LEANED TOWARD THE GFS GRIDDED OVERNIGHT LOWS IN THE LOWER TO MID 50S...WITH THE WARMEST TEMPERATURES OVERNIGHT QUITE POSSIBLY NEAR THE VIRGINIA BORDER UNDER THICKER CLOUDS AND DEEPER MOISTURE. FOR THE PERIOD WEDNESDAY THROUGH SATURDAY...UPPER-LEVEL LOW PRESSURE WILL ONLY SLOWLY LIFT AWAY FROM CENTRAL NORTH CAROLINA. THE ECMWF HAS GENERALLY BEEN FASTER LIFTING THE LOW TO THE NORTHEAST...BUT GIVEN THE CLOSED NATURE OF THE UPPER LOW...IT MAY BE A LITTLE SLOWER WITH COLD TEMPERATURES ALOFT LINGERING INTO THURSDAY. COARSE MODEL SOUNDINGS FROM BOTH THE GFS AND THE ECMWF ARE SLIGHTLY MORE CAPPED TOWARD THE SANDHILLS WEDNESDAY AS COMPARED TO FARTHER NORTH...AND EVEN THE SLOWER AND MORE UNSTABLE GFS HAS DECENT LOW-LEVEL CIN BELOW STEEP LAPSE RATES ALOFT...WITH THE STEEPEST LAPSE RATES CLOSER TO THE CENTER OF THE LOW OVER THE NORTHERN COASTAL PLAIN. THE HIGHEST CHANCES FOR SHOWERS WEDNESDAY SHOULD BE NORTH OF A LINE FROM WILSON TO ROXBORO...GRADUALLY DIMINISHING SOUTH FARTHER FROM THE LOW AND DEEPER MOISTURE. BY THURSDAY...THINKING THE LOW WILL MAKE SLOW PROGRESS NORTH AND NORTHEAST...ANTICIPATE LINGERING ISOLATED CHANCES FOR SHOWERS NORTH AND NORTHEAST OF THE TRIANGLE. HEIGHTS ALOFT THEN START TO RISE AND...WITH INCREASING SUBSIDENCE...THE END OF THE NEXT WORK WEEK SHOULD BE DRY AND SEASONABLY MILD. HEIGHTS ALOFT WILL LIKELY START TO FALL AGAIN FOR THE WEEKEND IN RESPONSE TO UPPER-LEVEL TROUGHINESS MOVING FROM CANADA INTO THE GREAT LAKES. THE ECMWF HAS GENERALLY BEEN FASTER THAN THE GFS WITH A POSITIVELY-TILTED FRONT MOVING TOWARD CENTRAL NORTH CAROLINA OVER THE WEEKEND. SOMETIMES POSITIVELY-TILTED FRONTS END UP BEING SLOWER THAN EXPECTED WITH THE ONSET OF SHOWERS IF SURFACE HIGH PRESSURE AHEAD OF A FRONT IS AT LEAST MODERATELY STRONG. IN THIS CASE... THOUGH...IN THE WAKE OF THE UPPER-LEVEL LOW...HIGH PRESSURE RIDGING THAT IS FORECAST INTO THE SOUTHEAST AND GULF OF MEXICO SEEMS RELATIVELY WEAKER...AND AS SUCH THERE MAY BE THE POTENTIAL FOR BETTER MOISTURE TRANSPORT AND CHANCES FOR SHOWERS MORE LIKELY IN THE WESTERN PIEDMONT BY SATURDAY AFTERNOON...AND ACROSS ALL OF CENTRAL NORTH CAROLINA SATURDAY NIGHT. HIGH TEMPERATURES WILL BE FORECAST BELOW NORMAL WEDNESDAY...AND AROUND NORMAL BY THE START OF NEXT WEEKEND. OVERNIGHT LOWS SHOULD BE NEAR OR ABOVE NORMAL. JUST TO NOTE...THE LAST 80-DEGREE DAY AT KGSO WAS APRIL 17...AND APRIL 19 AT BOTH KRDU AND KFAY. ASSUMING WE MAKE IT TO 80 BY THE END OF THE WEEK...IT WILL HAVE BEEN AROUND THREE WEEKS SINCE THE LAST TOUCH OF 80. FOR WHAT IT IS WORTH...LAST MAY...CENTRAL NORTH CAROLINA HAD ALREADY EXPERIENCED AROUND 90 TO THE LOWER 90S EARLY IN THE MONTH. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 1240 AM SUNDAY... BRISK AND GUSTY SURFACE WINDS FROM THE ENE (FROM 060-080 DEGREES) WILL PERSIST THROUGH TODAY/TONIGHT... AND THIS FLOW OF MOIST ATLANTIC AIR INTO NC WILL MAKE SUB-VFR CONDITIONS DOMINANT OVER CENTRAL NC TAF SITES. CLOUDS BASED AT ONE TO THREE THOUSAND FT AGL HAVE VARIED FROM SCATTERED TO BROKEN OVER THE LAST SEVERAL HOURS (TOPPED BY BROKEN VFR CLOUDS BASED FOUR THOUSAND TO TWELVE THOUSAND FT AGL)... MAKING IT DIFFICULT TO PINPOINT EXACTLY WHEN AND WHERE PERIODIC MVFR CIGS WILL PREVAIL. WITH LOWER-THAN-USUAL CONFIDENCE... EXPECT MAINLY VFR CIGS THROUGH 09Z-10Z THIS MORNING... FOLLOWED BY MVFR TO IFR CIGS AFTER 10Z. A FEW LIGHT SPRINKLES OR DRIZZLE ARE POSSIBLE THIS MORNING THROUGH MID AFTERNOON... BUT VSBYS SHOULD REMAIN MOSTLY VFR AND THE HEAVIEST RAINFALL WILL HOLD WEST OF A LINE FROM MT AIRY TO SALISBURY TO CLT. THE MVFR/IFR CIGS SHOULD RISE TO VFR AFTER 16Z-18Z THIS MORNING. MORE SUBSTANTIAL RAIN AND SUB-VFR VSBYS/CIGS WILL MOVE IN SLOWLY FROM THE SW TOWARD THE NE THIS AFTERNOON/ EVENING... REACHING INT/GSO/FAY AFTER 21Z... BUT NOT EXPECTED TO REACH RDU/RWI UNTIL NEAR OR AFTER 06Z TONIGHT. SUSTAINED WINDS OF 10-16 KTS GUSTING TO AROUND 20 KTS WILL CONTINUE THROUGH THE FORECAST PERIOD. LOOKING BEYOND 06Z TONIGHT: GOOD CHANCE OF CONTINUED DOMINATION OF SUB-VFR CONDITIONS WITH PERIODS OF RAIN THROUGH AT LEAST TUESDAY AS AN UPPER LEVEL LOW SLOWLY CROSSES THE REGION. BRISK ENE SURFACE WINDS WILL PERSIST THROUGH MONDAY BEFORE WEAKENING MONDAY NIGHT. SHALLOW IFR FOG IS POSSIBLE TUESDAY NIGHT/WEDNESDAY MORNING... AND AGAIN THURSDAY MORNING. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM... LONG TERM...DJF AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
313 AM CDT SUN MAY 5 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 313 AM CDT SUN MAY 5 2013 THE LATEST WATER VAPOR IMAGERY SHOWS AN H5-H3 CIRCULATION OVER CENTRAL SOUTH DAKOTA. LATEST RADAR SHOWS A NARROW AND PERSISTENT BAND OF LIGHT RAIN BING STEERED NORTHBOUND BY THE AFOREMENTIONED UPPER LOW FROM EASTERN SOUTH DAKOTA...INTO LAMOURE AND DICKEY COUNTIES OF NORTH DAKOTA. THE LATEST RAP AND GFS CONTINUE WITH THE IDEA OF LIGHT RAIN THROUGH MID AFTERNOON...AND HAVE TRENDED POPS APPROPRIATELY...BEGINNING WITH CATEGORICAL AND TRENDING LOWER THIS AFTERNOON. WITH WESTERN AND CENTRAL NORTH DAKOTA ESSENTIALLY IN A COL AREA...THE UPPER LOW REMAINS NEARLY STATIONARY AND MEANDERS LITTLE THROUGH THE SHORT TERM PERIOD. H85 TEMPERATURES RISE A FEW DEGREES IN THE NEXT TWO DAYS...CONSEQUENTLY WILL SEE WARMING TEMPERATURES REFLECTED AT THE SURFACE. HIGHS TODAY WILL REACH INTO 60S WITH LIGHT WINDS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 313 AM CDT SUN MAY 5 2013 HIGHLIGHTS OF THE EXTENDED FORECAST IS A WARM UP TO SLIGHTLY ABOVE NORMAL TEMPERATURES IN THE 70S ON MONDAY INTO TUESDAY..WITH SCATTERED RAIN SHOWERS AND THUNDERSTORMS POSSIBLE WEDNESDAY INTO FRIDAY...WITH TEMPERATURES COOLING LATE IN THE WEEK. A SPLIT FLOW UPPER LEVEL PATTERN IS EXPECTED TO BE IN PLACE ACROSS THE CONUS THROUGH AT LEAST TUESDAY WITH A CUTOFF LOW ACROSS THE SOUTHEASTERN CONUS...AND A SECOND ACROSS THE DESERT SOUTHWEST. THIS PATTERN SUPPORTS DRY CONDITIONS FOR THE NORTHERN PLAINS WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES. THE NEXT CHANCE FOR PRECIPITATION...POSSIBLY THUNDERSTORMS...IS WEDNESDAY INTO FRIDAY AS POTENTIAL NORTHERN STREAM ENERGY SINKS SOUTH ACROSS THE NORTHERN PLAINS. THIS SLIGHT SHIFT OF THE POLAR JET FURTHER SOUTH WITH NORTHWEST FLOW ALOFT SUPPORTS A POSSIBLE COOL DOWN BACK INTO THE 60S THURSDAY AND FRIDAY...AND THE 50S BY SATURDAY. OVERALL...UTILIZED A BLEND OF THE 00 UTC GUIDANCE SUITE FOR MOST FIELDS...FAVORING THE WARMER EDGE OF TEMPERATURE GUIDANCE WHICH HAS SHOWN GREATER VERIFICATION SCORES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 313 AM CDT SUN MAY 5 2013 VFR CIGS/VSBYS NEXT 24HRS WITH MOSTLY CLEAR SKIES AND LIGHT WINDS. KJMS WILL BE THE ONLY AERODROME WITH BKN CIGS AT AROUND 10KFT. && .HYDROLOGY... ISSUED AT 313 AM CDT SUN MAY 5 2013 THE SOURIS RIVER CONTINUES TO BE A COMPLEX MIXTURE OF LOCATIONS RISING WHILE OTHER FORECAST POINTS ARE IN RECESSION. LOWER RELEASES FROM BOUNDARY DAM AND REDUCED SNOWMELT RUNOFF BELOW ALAMEDA AND RAFFERTY DAMS HAS RESULTED IN THE ENTIRE UPPER SOURIS RIVER BASIN FROM SHERWOOD TO MINOT TO VELVA FALLING AND REMAINING BELOW FLOOD STAGE. FARTHER DOWNSTREAM AT TOWNER...BANTRY AND WESTHOPE...THE SOURIS RIVER REMAINS STEADY TO RISING AS FLOOD WATERS SLOWLY MAKE THEIR WAY THROUGH THE AREA. WILLOW CREEK NEAR WILLOW CITY IS EXPECTED TO EXPERIENCE ANOTHER RISE TO JUST ABOVE MINOR FLOOD STAGE THROUGH MONDAY. MUCH OF THE MELT WATER GENERATED IN THIS AREA APPEARS TO BE GOING INTO THE SOIL AND TEMPERING EARLIER EXPECTATIONS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KS LONG TERM...AYD AVIATION...KS HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1257 AM CDT SUN MAY 5 2013 .UPDATE... ISSUED AT 1253 AM CDT SUN MAY 5 2013 UDPATED TO EXTEND CATGEORICAL POPS FOR LIGHT RAIN INTO MIDDAY SUNDAY FOR SOUTHEAST ND INTO NW MN FROM FORMAN-WAHPETON THROUGH FARGO TO BEMIDJI-WASKISH AS BAND OF MID LEVEL CONVERGENCE REMAINS IN THAT AREA UNTIL IT FINALLY FALLS APART LATER SUNDAY. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 342 PM CDT SAT MAY 4 2013 MAIN CHALLENGE FOR THIS FORECAST PACKAGE WILL BE PCPN. LATEST ANALYSIS SHOWS UPPER LOW OVER NRN ARKANSAS. EXPECT SLOWER CHANGES TO THE LOCAL WEATHER OVER THE NEXT FEW DAYS AS THE OVERALL PATTERN SHOWS A REX BLOCK OVER WRN CONUS AND ANOTHER BLOCK OVER THE EAST COAST. MODELS INITIALIZED WELL AND AND OPTED FOR A BLENDED SOLN. FOR TODAY AND TONIGHT...MAIN QUESTION IS WHERE AREA OF PCPN WILL SETTLE. REGIONAL RADAR SHOWS BAND OF PCPN MOVING NORTH INTO WEST CENTRAL AND NW MINNESOTA. HRRR AND RAP MODELS IN GENERAL AGREEMENT ON PLACEMENT OF PCPN AND EXPECT MOST PCPN AMOUNTS WILL BE UNDER A QUARTER INCH OVER THE NEXT 24 HOURS. THE 300K ISENTROPIC ANALYSIS SHOWS SOME DECENT LIFT AND EXPECTING AN 850MB BAROCLINIC ZONE TO SET UP. HOWEVER...CONDENSATION PRESSURE DEFICITS WEAK SO FOR NOW WILL ONLY KEEP LIKELY POPS IN THAT AREA. FOR SUNDAY...LOOKING FOR THE BAROCLINIC ZONE TO SLOWLY SLIDE SOUTHEAST AND WILL SEE THE END OF PCPN. OTHERWISE...LOOKING FOR DRIER WEATHER GOING INTO MONDAY. EXTENSIVE CLOUD COVER WILL KEEP TEMPERATURES A BIT LOWER TODAY INTO SUNDAY WHEN THE UPPER RIDGE BEGINS SLIDE OVER THE AREA AND A WARMING TREND BEGINS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 342 PM CDT SAT MAY 4 2013 12 UTC GFS/ECMWF SHOW THE FORECAST AREA IN POORLY DEFINED SPLIT FLOW MID-WEEK...TRANSITIONING TO NORTHWEST FLOW ALOFT FRIDAY NIGHT INTO SATURDAY WITH A STRONG CANADIAN COLD FRONT. PRECIPITATION CHANCES THROUGH FRIDAY WILL DEPEND ON EVOLUTION OF A WEAK CUT-OFF LOW ACROSS THE SOUTHERN ROCKIES. MOST MODELS PAINT MOST QPF ACROSS THE CENTRAL PLAINS...BUT SOME DOES MAKE IT FARTHER NORTH. WITH THESE CUT-OFF LOWS NOT A LOT OF CONFIDENCE...SO WILL KEEP ALL BLEND 20-40 POPS FOR MOST OF THE WEEK. HOWEVER...THERE SHOULD BE MORE DRY PERIODS THAN WET. WILL ALSO LIMIT THUNDER MENTION AS INSTABILITY APPEARS TO BE MINIMAL AT THIS TIME. TEMPERATURES WILL BE ON THE WARM-SIDE OF THE MOST RECENT THERMAL REGIME WITH HIGHS IN THE 60S AND LOWS MAINLY IN THE 40S. IT DOES APPEAR CONDITIONS WILL COOL ON SATURDAY WITH PASSAGE OF THE FRONT FRIDAY NIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1253 AM CDT SUN MAY 5 2013 BEMIDJI-PARK RAPIDS REGION SHOULD STAY IN IFR-LOW END MVFR CIGS THROUGH 16Z SUNDAY AS MOISTURE REMAINS IN THE AREA WITH LIGHT NORTHEAST WINDS. IN PRECIP BAND FROM FARGO INTO NW MN VFR CLDS THOUGH AS MOISTURE ISNT AS DEEP. VFR CLOUDS IN GRAND FORKS TO MORE CIRRUS IN DVL. SLOW DECREASE IN CLOUDS FROM THE NORTHWEST SUN AFTN-EVE WITH LIGHT NORTH-NORTHEAST WINDS TURNING VARIABLE SUN LATE AFTN-EVE. && .HYDROLOGY... ISSUED AT 1258 PM CDT SAT MAY 4 2013 THE BROAD CREST WAVE OF SNOWMELT RUNOFF IS APPROACHING THE DRAYTON AREA THIS WEEKEND WITH A CREST EXPECTED NEAR 40 FEET. THE CREST WAVE WILL MOVE INTO THE PEMBINA REGION TOWARD THE END OF NEXT WEEK WITH A FORECAST NEAR 48.5 FEET...JUST UNDER MAJOR FLOOD STAGE. A SECOND ROUND OF RUNOFF IS EXPECTED ALONG THE PEMBINA RIVER WITH ADDITIONAL RISES FORECAST AT WALHALLA AND NECHE THIS NEXT WEEK. ELSEWHERE RIVERS CONTINUE TO RECEDE AS NO NEW RUNOFF IS OCCURRING WITH THE DRY WEATHER OVER THE PAST WEEK. AREAL FLOODING...WILL KEEP THE NORTH DAKOTA WARNINGS GOING AS OVERLAND FLOODING CONTINUES TO CAUSE ISSUES AND ROAD CLOSURES. AS FOR THE BELTRAMI AND CLEARWATER COUNTIES WILL CANCEL AFTER CONFIRMING WITH COUNTY OFFICIALS THAT OVERLAND WATER HAS DIMINISHED DRAMATICALLY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...RIDDLE SHORT TERM...HOPKINS LONG TERM...ROGERS AVIATION...RIDDLE HYDROLOGY...JK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1215 AM CDT SUN MAY 5 2013 .UPDATE... ISSUED AT 1215 AM CDT SUN MAY 5 2013 LATEST WATER VAPOR IMAGERY SHOWS A H5-H3 CIRCULATION TAKING SHAPE OVER SOUTH CENTRAL SOUTH DAKOTA. LONG FETCH OF LIGHT RAIN EXTENDING IN EASTERN SOUTH DAKOTA WILL CONTINUE TO BE PULLED NORTH INTO OUR SOUTHEAST COUNTIES OF LAMOURE AND DICKEY OVERNIGHT. THE RAP AND GFS MAINTAIN LIGHT PRECIPITATION THROUGH 20Z SUNDAY...AND SEE NO REASON TO DEVIATE MUCH FROM THIS. THUS...HAVE INCREASED POPS TO CATEGORICAL THROUGH 12Z SUNDAY...AND GRADUALLY SUBSIDING TO LIKELY POPS THROUGH 18Z SUNDAY. THE GFS/RAP DO SHOW SOME WANING OF THE PRECIPITATION BETWEEN 12Z AND 18Z SUNDAY...BEFORE ENDING BY MID AFTERNOON. THE REST OF THE FORECAST REMAINS IN GOOD STANDING AND MADE LITTLE OR NO CHANGES TO THE OTHER ELEMENTS. UPDATE ISSUED AT 1001 PM CDT SAT MAY 4 2013 STABLE WEATHER PATTERN CONTINUES WITH SURFACE HIGH ACROSS THE DAKOTAS INTO SOUTHERN CANADA. UPPER LEVEL LOW CONTINUES TO SPREAD SOME MIDDLE AND HIGH CLOUDS ACROSS EASTERN NORTH DAKOTA. SKIES WERE MOSTLY CLEAR WEST. RADARS CONTINUE TO SHOW SOME LIGHT RAIN ACROSS EASTERN DICKEY AND LAMOURE COUNTIES...WITH OAKES REPORTING SOME LIGHT RAIN IN THE PAST HOUR. RAISED THE CHANCE OF RAIN ACROSS DICKEY AND LAMOURE COUNTIES THROUGH EARLY MORNING OTHERWISE CURRENT TREND LOOKS GOOD. FOR HYDROLOGY...LOWER RELEASES FROM THE CANADIAN DAMS AND DECREASED EXPECTATIONS FROM SNOW MELT RUNOFF HAS RESULTED IN THE UPPER SOURIS FALLING BELOW FLOOD STAGE FROM SHERWOOD...THROUGH MINOT TO VELVA. THE LOWER SOURIS FROM TOWNER TO BANTRY TO WESTHOPE AS WELL AS THE WILLOW CREEK NEAR WILLOW CITY WILL CONTINUE TO SEE STEADY TO SLOW RISES IN RIVER LEVELS AS THE WATER MAKES ITS WAY THROUGH THE LOWER SOURIS RIVER VALLEY THROUGH NEXT WEEK. UPDATE ISSUED AT 609 PM CDT SAT MAY 4 2013 UPPER LEVEL LOW SWIRLING LIGHT RAIN ACROSS SOUTHEAST NORTH DAKOTA. ABERDEEN REPORTED LIGHT RAIN WITH THE LAST HOUR. CUTOFF FOR THE RAIN WILL BE ACROSS CENTRAL DICKEY AND EASTERN LAMOURE COUNTIES THIS EVENING. CURRENT FORECAST GOOD...JUST RAISED THE CHANCE OF RAIN EASTERN DICKEY AND LAMOURE COUNTIES THIS EVENING. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 332 PM CDT SAT MAY 4 2013 A FAIRLY STAGNANT WEATHER PATTERN WILL CONTINUE OVER WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE PERIOD. NORTHEASTERLY WINDS THIS AFTERNOON WILL BECOME LIGHT AND VARIABLE OVERNIGHT AND SUNDAY AS HIGH PRESSURE RE-ESTABLISHES ITSELF ACROSS THE REGION. AS FAR AS PRECIP CHANCES ARE CONCERNED...WRAP AROUND MOISTURE ASSOCIATED WITH A STRONG UPPER LOW OVER THE LOWER MISSISSIPPI RIVER VALLEY WILL GENERATE A SLIGHT CHANCE OF LIGHT RAIN OVER THE EASTERN PORTIONS OF LAMOURE AND DICKEY COUNTIES TONIGHT. OTHERWISE...DEEP LAYER ANTICYCLONIC FLOW WILL MAINTAIN DRY CONDITIONS ACROSS WESTERN AND CENTRAL NORTH DAKOTA THROUGH SUNDAY. DUE TO DECREASING WINDS AND MOSTLY CLEAR SKIES...TEMPERATURES SHOULD RADIATE TO WELL BELOW NORMAL READINGS TONIGHT WITH READINGS GENERALLY IN THE 20S WEST OF THE MISSOURI RIVER AND IN THE 30S EAST OF THE MISSOURI RIVER. HIGHS SUNDAY SHOULD BE NEAR NORMAL WITH READINGS MAINLY IN THE 60S. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 332 PM CDT SAT MAY 4 2013 MAIN HIGHLIGHTS OF THE EXTENDED FORECAST INCLUDES A CONTINUED WARM UP TO SLIGHTLY ABOVE NORMAL TEMPERATURES IN THE 70S ON MONDAY POSSIBLY INTO WEDNESDAY...WITH SCATTERED RAIN SHOWERS AND POSSIBLE THUNDERSTORMS TUESDAY AFTERNOON INTO FRIDAY. A SPLIT FLOW UPPER LEVEL PATTERN IS EXPECTED TO BE IN PLACE ACROSS THE CONUS THROUGH AT LEAST TUESDAY MORNING WITH A CUTOFF LOW ACROSS THE SOUTHEASTERN CONUS...AND A SECOND SLOWLY PROPAGATING ONSHORE ACROSS CALIFORNIA. THIS PATTERN SUPPORTS DRY CONDITIONS FOR THE NORTHERN PLAINS WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES WITH THE LACK OF LARGE SCALE GREEN UP THUS FAR. THE NEXT CHANCE FOR PRECIPITATION...POSSIBLY THUNDERSTORMS...IS TUESDAY AFTERNOON AS SOME IMPULSE ENERGY FROM THE WESTERN CUTOFF LOW MOVES INTO THE CENTRAL/NORTHERN PLAINS TUESDAY AFTERNOON THROUGH FRIDAY...AND AT THE SAME TIME POTENTIAL NORTHERN STREAM ENERGY SINKS SOUTH ACROSS THE NORTHERN PLAINS. THIS SLIGHT SHIFT OF THE POLAR JET FURTHER SOUTH MAY LEAD TO A SLIGHT COOL DOWN BACK INTO THE 60S THURSDAY AND FRIDAY...AND INTO THE 50S FOR NEXT SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1215 AM CDT SUN MAY 5 2013 VFR CIGS/VSBYS NEXT 24HRS WITH MOSTLY CLEAR SKIES AND LIGHT WINDS. KJMS WILL BE THE ONLY AERORDROME WITH BKN CIGS AT AROUND 10KFT. && .HYDROLOGY... ISSUED AT 332 PM CDT SAT MAY 4 2013 AFTER COORDINATION WITH EMERGENCY MANAGEMENT AFFECTED BY OVERLAND FLOODING...DECIDED TO CANCEL THE AREAL FLOOD WARNING FOR OVERLAND FLOODING FOR WELLS...PIERCE...AND FOSTER COUNTIES. EVEN THOUGH OVERLAND FLOODING CONTINUES TO DIMINISH...ISOLATED INSTANCES OF WATER OVER THE ROADWAY CONTINUE TO BE REPORTED. AS A RESULT...WILL CONTINUE TO HIGHLIGHT THIS THREAT IN THE HWO. THE RIVER FLOOD WATCH FOR THE JAMES RIVER AT GRACE CITY HAS BEEN CANCELLED AND REPLACED WITH A HYDROLOGIC STATEMENT. THE RIVER LEVEL HAS FALLEN BELOW MINOR FLOOD STAGE AND WILL CONTINUE A SLOW FALL FOR THE NEXT SEVERAL DAYS. HOWEVER...THE FLOOD WARNING FOR THE PIPESTEM CREEK NEAR PINGREE SHOULD REMAIN ABOVE MODERATE STAGE FOR THE NEXT FEW DAYS. MINOR TO MODERATE FLOODING IS STILL FORECAST FOR THE SOURIS RIVER BASIN NEAR SHERWOOD...TOWNER...BANTRY...WILLOW CITY...AND WESTHOPE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KS SHORT TERM...TM LONG TERM...JV AVIATION...KS HYDROLOGY...TM
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1137 PM CDT SAT MAY 4 2013 .UPDATE...FOR 06Z AVIATION FORECAST .AVIATION... POOR FLYING CONDITIONS WILL CONTINUE FOR THE NEXT 24 HOURS. COLD UPPER LOW CENTERED OVER EASTERN ARKANSAS AT 04Z WITH MOISTURE PLUME OFF THE ATLANTIC THROUGH GEORGIA AND ACROSS EASTERN HALF OF TENNESSEE INTO KENTUCKY. WIDESPREAD RAIN WILL CONTINUE ACROSS EASTERN HALF OF MID STATE AND PLATEAU WITH THE HEAVIEST RAINS FORECAST TO FALL IN EASTERN MIDDLE TENNESSEE AND PLATEAU OVERNIGHT TONIGHT. AS UPPER LOW MOVES EAST LIFT AND INSTABILITY WILL INCREASE WITH ACTIVITY BECOMING MORE SHOWERY BY SUNDAY AFTERNOON WITH THUNDERSTORM POTENTIAL INCREASING SUNDAY AFTERNOON AND EVENING ESPECIALLY SOUTH HALF OF THE MID STATE CLOSER TO THE CENTER OF COLD CORE ALOFT. BOYD && .PREV DISCUSSION... /ISSUED 832 PM CDT SAT MAY 4 2013/ UPDATE... LATEST RADAR IMAGERY SHOWS LIGHT TO MODERATE RAIN SHIELD REMAINS ACROSS EASTERN ZONES...GENERALLY ALONG AND EAST OF A LINE FROM GALLATIN TO MANCHESTER. WEST OF THAT LINE...SCATTERED TO NUMEROUS LIGHT TO OCCASIONALLY MODERATE SHOWERS HAVE DEVELOPED WESTWARD TO NEAR A CLARKSVILLE TO PULASKI LINE. LOCATIONS REMAIN DRY TO THE WEST OF THERE...BUT LIGHT SHOWERS HAVE BEGUN SPREADING ACROSS THE TENNESSEE RIVER IN THE PAST HOUR IN ASSOCIATION WITH THE APPROACHING UPPER LOW. TEMPERATURES REMAIN UNUSUALLY COLD AND WIDELY VARIABLE AT THIS HOUR...WITH LOW 50S ON THE PLATEAU...MID TO UPPER 40S IN THE CENTRAL CWA...AND LOW 50S IN THE SOUTHWEST. HAVE MADE SEVERAL ADJUSTMENTS TO GRIDS/ZONES BASED ON LATEST OBS AND RADAR TRENDS. RAISED POPS ACROSS THE WEST WHERE LIGHT RAIN IS SPREADING EASTWARD WITH UPPER LOW...AND EXTENDED LIKELY POPS FURTHER TO THE WEST TO NEAR A CLARKSVILLE/PULASKI LINE. LATEST HRRR RUNS INDICATE CURRENT SHOWER ACTIVITY ALONG THE I-65 CORRIDOR WILL CONTINUE THIS EVENING THEN DISSIPATE OVERNIGHT AS DRIER AIR AROUND CIRCULATION OF UPPER LOW SHIFTS EASTWARD. AS THIS OCCURS...HRRR INDICATES PRECIPITATION INTENSITIES WITHIN RAIN SHIELD WILL STRENGTHEN OVERNIGHT AS SURFACE TROUGH DEEPENS AND UPPER LOW APPROACHES...LEADING TO AN INCREASE IN RAINFALL RATES IN THE FLOOD WATCH AREA. AS MENTIONED PREVIOUSLY...OF PARTICULAR CONCERN WILL BE THE SOUTHERN PLATEAU COUNTIES OF VAN BUREN...WHITE...CUMBERLAND...AND PUTNAM WHERE HIGHEST MOISTURE TRANSPORT WILL BE FOCUSED AND OROGRAPHIC LIFT IN THE 2000-3000 FT TERRAIN ENHANCES PRECIPITATION. THE CROSSVILLE ASOS HAS RECEIVED 1.31 INCHES OF RAIN AS OF 7 PM...AND ANOTHER 1 TO 1.5 INCHES IS POSSIBLE THROUGH MIDNIGHT IN THE FLOOD WATCH AREA. STORM TOTAL AMOUNTS THROUGH SUNDAY FROM 2 TO POTENTIALLY 4 INCHES STILL APPEAR REASONABLE IN EASTERN ZONES AND NO CHANGES ARE PLANNED TO THE FLOOD WATCH. SHAMBURGER PREV DISCUSSION... /ISSUED 646 PM CDT SAT MAY 4 2013/ UPDATE...FOR 00Z AVIATION FORECAST AVIATION... POOR FLYING CONDITIONS TO CONTINUE ACROSS THE MID STATE NEXT 24 HOURS AS UPPER LOW CURRENTLY SPINNING OVER CENTRAL ARKANSAS KEEPS A MOISTURE PLUME STREAMING INTO TENNESSEE. SHORT RANGE MODELS HAVE GOOD HANDLE ON RAINFALL WITH THE HEAVIEST TO FALL ALONG THE CENTRAL AND SOUTHERN PLATEAU COUNTIES WHERE RAINFALL WILL BECOME HEAVY OVERNIGHT. RAIN WILL CONTINUE ON SUNDAY. HAVE FORECASTED LOW IFR CEILINGS AT CROSSVILLE IN THE OVERNIGHT ALONG WITH HEAVY RAINFALL. ALSO EXPECT LOW IFR CEILINGS AT NASHVILLE BUT WITH LIGHT RANIFALL. BOYD PREV DISCUSSION... /ISSUED 613 PM CDT SAT MAY 4 2013/ MESOSCALE UPDATE... LATEST RADAR IMAGERY SHOWS MAIN AXIS OF MODERATE TO OCCASIONALLY HEAVY RAIN NOW OVER THE UPPER CUMBERLAND REGION...GENERALLY EAST OF A LINE FROM LAFAYETTE TO ALTAMONT. LATEST HRRR MODEL RUNS INDICATE THIS MAIN RAIN BAND WILL REMAIN IN PLACE FOR ANOTHER 12 TO 18 HOURS AS A SURFACE TROUGH OF LOW PRESSURE ARCING SOUTHEAST TO NORTHWEST REMAIN IN PLACE AND DEEPENS WITH THE UPPER LOW APPROACHING FROM THE WEST. OBS FROM THE CROSSVILLE ASOS INDICATE RAINFALL RATES OF 0.10 TO 0.25 INCHES PER HOUR ARE OCCURRING IN THE HEAVIEST RAIN AREAS...WITH 1 TO 2 INCHES OF RAINFALL POSSIBLE JUST THROUGH MIDNIGHT. HEAVIEST RAIN TOTALS ARE EXPECTED TO BE ON THE SOUTHERN PLATEAU ACROSS VAN BUREN...WHITE...AND CUMBERLAND COUNTIES WHERE OROGRAPHIC ENHANCEMENT FROM THE HIGHER TERRAIN SQUEEZES OUT ADDITIONAL MOISTURE. FLOODING WILL BECOME AN INCREASING CONCERN IN THIS AREA AS WE CONTINUE THROUGH THE NIGHT AND ESPECIALLY ON SUNDAY. SHAMBURGER PREV DISCUSSION... /ISSUED 340 PM CDT SAT MAY 4 2013/ DISCUSSION... PRECIP CLEARING LINE HAS BEEN MAKING A SLOW EASTWARD MOVEMENT TODAY. AT 2PM THE CLEARING LINE WAS ROUGHLY ORIENTED PARALLEL TO I-65. THIS EASTWARD PROGRESSION MAY CONTINUE FOR A FEW MORE HOURS BUT WILL LIKELY STALL BY EVENING. CURRENTLY UPPER LEVEL LOW IS LOCATED OVER NRN AR WITH A SLOW ESE MOVEMENT. 2 SFC TROUGH ARE AT WORK WITH ONE LOCATED ALONG THE MS RIVER AND ANOTHER INVERTED VERSION OF A SFC TROUGH EXTENDING NORTHWARD THROUGH GA INTO EASTERN TN. AS THE UPPER LOW CONTINUES MOVING EASTWARD...INTENSIFICATION ALONG THE STATIONARY INVERTED TROUGH IS EXPECTED. THERE MAY EVEN BE A BIT OF RETROGRADE MOVEMENT WITH THE INVERTED TROUGH AS IT STRENGTHENS. SO FAR OMEGA RETURNS HAVE BEEN MARGINALLY IMPRESSIVE OVER EASTERN PORTIONS OF THE MID STATE WHERE THE RAIN IS ONGOING. TONIGHT HOWEVER...THE STRENGTHENING INVERTED TROUGH WILL TRANSLATE INTO GREATER FORCING AND THE RAINFALL INTENSITY LEVELS WILL PICK UP. THUS...THOUGH I WILL LIKELY BE CUTTING A FEW MORE CENTRAL COUNTIES FROM THE FLOOD WATCH...THE EASTERN THIRD OF OUR CWA(PLATEAU AND ADJACENT COUNTIES) ARE STILL VERY MUCH UNDER THE GUN. MODELS ARE ALL CONVERGING ON THE HEAVY RAINFALL POTENTIAL EXTENDING NORTHWARD INTO OUR SOUTHERN PLATEAU IN PARTICULAR. ADDITIVE RAINFALL ENHANCEMENT IS CLEARLY INDICATED WITH HRRR DATA ALONG WITH A GENERAL MODEL QPF CONSENSUS. AROUND 2 TO 3 INCHES OF ADDITIONAL RAINFALL WITH LOCALIZED AMOUNTS OF 4 INCHES ARE STILL POSSIBLE ACROSS OUR SOUTHERN PLATEAU. ELSEWHERE ACROSS THE WATCH AREA...WILL LEAN TOWARD AROUND 2 INCHES OF ADDITIONAL RAINFALL BEING POSSIBLE BUT WILL REFRAIN FROM THE EXTRA LOCALIZED WORDING. CURRENT THINKING FOR THE WATCH AREA IS TO INCLUDE AREAS ALONG AND EAST OF A LINE FROM MACON COUNTY TO COFFEE COUNTY. WILL KEEP THE WATCH GOING UNTIL 7 PM SUNDAY NIGHT. ALTHOUGH THE HEAVIEST ACTIVITY WILL MOVE EAST OF OUR COUNTIES BY 18Z...ITS GOOD TO KEEP THE WATCH GOING FOR A FEW MORE HOURS AS FLOODING CAN OFTEN OCCUR HOURS AFTER THE HEAVIER RAINFALL ENDS. SHOWER ACTIVITY...THOUGH LESS INTENSE...TO PERSIST INTO SUNDAY NIGHT AS THE UPPER LOW PASSES JUST TO OUR SOUTH. SOME SUNSHINE WILL RETURN ON MONDAY ALONG WITH WARMER TEMPS. IN THE EXT FCST...UPPER LOW WILL BE FAR ENOUGH EAST AND UPPER RIDGING WILL COMMENCE BY MID WEEK. THIS WILL EQUATE TO WARMER AND DRIER CONDITIONS. IN FACT...MAY GO POP FREE TUES NT INTO WED. UPPER RIDGE WILL BEGIN TO FLATTEN BY THE END OF THE WEEK. INSTABILITY PARAMETERS INDICATE INCREASE CAPES AND LOWERING CAP STRENGTHS BEGINNING ON THU. A SFC FRONT WILL THEN MOVE CLOSER BY FRIDAY AND SATURDAY AND THIS WILL ADD TO OUR SHOWER AND TSTM CHANCES. EXT TEMPS WILL BE RUNNING ABOVE NORMAL FOR THE LAST HALF OF THE EXTENDED...THU-SAT. WONT DEVIATE MUCH FROM MEX ADVICE. && .OHX WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH THROUGH SUNDAY EVENING FOR TNZ009>011-029>034- 063>066-077>080. && $$ 01
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1206 AM CDT SUN MAY 5 2013 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 306 PM CDT SAT MAY 4 2013 MAIN FORECAST CONCERN IS ON FOG AND DENSE FOG POTENTIAL TONIGHT CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED UPPER LOWS OVER NORTHERN CALIFORNIA AND IN ARKANSAS...WHILE AN UPPER HIGH WAS PRESENT ACROSS MUCH OF THE GREAT LAKES. FLOWING BETWEEN THE ARKANSAS UPPER LOW AND THE GREAT LAKES UPPER HIGH WAS A SHORTWAVE OVER CENTRAL WISCONSIN. DPVA AHEAD OF THIS SHORTWAVE COMBINED WITH DAYTIME HEATING AND SOME EVAPOTRANSPIRATION HAS AIDED IN SHOWERS NORTH OF I-94. FARTHER SOUTH...SCATTERED SHOWERS ARE ALSO PRESENT ACROSS PORTIONS OF NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN...AIDED BY INSTABILITY PRODUCED BY DEWPOINTS CLIMBING INTO THE LOW 50S AND SOME COOLER TEMPS ALOFT. REGARDING TEMPERATURES... THEY VARY GREATLY ACROSS THE FORECAST AREA...FROM THE 40S IN ROCHESTER TO 60S ACROSS MUCH OF SOUTHWEST INTO CENTRAL WISCONSIN. THE WARMER TEMPERATURES ARE A RESULT OF MORE SUN AND AN EASTERLY FLOW OF WARMER AIR COMING OUT OF THE UPPER HIGH. 12Z GRB SOUNDING SHOWED 900MB TEMPS OF +14C...COMPARED TO +5C AT MPX. BOTH SOUNDINGS HAD AN INVERSION...BUT MPX WAS MUCH DEEPER AND THUS COMBINED WITH THE CLOUDS WAS HELPING TO KEEP TEMPERATURES COOLER IN SOUTHEAST MN. THE DEEPER INVERSION ALSO HAS HELPED TRAPPED PLENTY OF LOW LEVEL MOISTURE...INCLUDING THAT FROM THE MELTING SNOWPACK...WHICH RESULTED IN LOW VISIBILITIES OVER NORTHEAST IOWA...SOUTHEAST MINNESOTA AND EVEN NORTH CENTRAL WISCONSIN THIS MORNING. VERY LITTLE CHANGE IS FORECAST IN THE UPPER LEVEL PATTERN THROUGH SUNDAY...EXCEPT FOR SOME UPPER RIDGING TRYING TO BUILD WESTWARD THROUGH THE FORECAST AREA FROM THE UPPER HIGH. THIS UPPER RIDGING SHOULD HELP TO KEEP THE FORECAST AREA DRY THROUGH SUNDAY AFTER ANY SHOWERS FROM THIS AFTERNOON DISSIPATE WITH LOSS OF HEATING. THE BIG ISSUE TONIGHT IS FOG. CONTINUING SNOW MELT OVER WESTERN AND FAR NORTHERN PORTIONS OF THE AREA WILL HELP TO KEEP THE LOW LEVELS OF THE ATMOSPHERE MOIST. MEANWHILE...MODELS MAINTAIN AN INVERSION OVER THE SNOW PACK AREAS...WHICH MAKES SENSE WITH THE EASTERLY FLOW OF WARMER AIR ALOFT ABOVE A NORTH-NORTHEAST FLOW OF COOL AIR AT THE SURFACE. GIVEN THAT 1/4SM FOG FORMED THIS MORNING AND WINDS ARE GOING TO BE EVEN LIGHTER...SITUATION SEEMS VERY FAVORABLE FOR FOG AND EVEN DENSE FOG. ADDITIONALLY...SOME CLEARING COULD TRY TO WORK IN BASED ON VISIBLE SATELLITE TRENDS...MAKING FOG EVEN MORE FAVORABLE. SREF PROBABILITIES FOR VISIBILITY LESS THAN 1 MILE ARE MUCH MORE EXPANSIVE AND HIGHER TONIGHT COMPARED TO THIS MORNING...AND THE 04.00Z/06Z/12Z HIRES ARW/NMM ALL SHOW MORE FOG TOO THAN THIS MORNING. LATEST HRRR/RAP ALSO DEVELOP FOG OVER THE SNOW PACK. GIVEN THESE SIGNALS...HAVE INCREASED FOG COVERAGE AND ISSUED A DENSE FOG ADVISORY...CONFINED TO THE AREAS WITH MELTING SNOW PACK. COMBINATION OF HIGHER DEWPOINTS TONIGHT AND COME CLOUDS WILL RESULT IN A WARMER NIGHT TONIGHT. WARMER TEMPERATURES ARE ALSO ON TAP TOMORROW WITH MORE SUN LIKELY AS DRIER AIR COMING OUT OF THE UPPER HIGH ADVECTS WESTWARD. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 306 PM CDT SAT MAY 4 2013 SUNDAY NIGHT THROUGH TUESDAY...NOT MUCH TO TALK ABOUT WITH REGARDS TO THE UPPER LEVEL PATTERN. THE UPPER HIGH THAT IS OVER THE GREAT LAKES SLOWLY BREAKS DOWN IN RESPONSE TO A SHORTWAVE TROUGH TRACKING ACROSS NORTHERN ONTARIO COME MONDAY. STILL...THE FORECAST AREA JUST SITS IN A LACK OF ANY UPPER LEVEL FLOW...SPLIT BETWEEN A SOUTHERN STREAM TRACKING ACROSS THE SOUTHERN U.S. AND THE NORTHERN STREAM WELL UP IN CANADA. MEANWHILE AT THE SURFACE...HIGH PRESSURE CURRENTLY PRESENT OVER NORTHERN ONTARIO IS PROGGED TO BUILD SOUTH INTO THE AREA DURING THIS PERIOD. DRYING AIR WITH THIS HIGH PRESSURE AREA COMBINED WITH LACK OF ANY FLOW ALOFT WILL HELP TO KEEP THE FORECAST AREA DRY. MAIN CONCERN AGAIN IS FOG. SREF PROBABILITIES FOR VISIBILITY LESS THAN 1 MILE SHOOT BACK UP AGAIN SUNDAY NIGHT... CONFINED TO THE SNOW PACK AREA. ONE QUESTION WOULD BE IS HOW MUCH SNOW IS LEFT AFTER MELTING FROM THIS WEEKEND. HOWEVER...SOILS ARE LIKELY GOING TO BE MOIST...AND WITH LIGHT WINDS AND CLEARING FROM THE HIGH PRESSURE AREA BUILDING IN...RECIPE LOOKS GOOD AGAIN FOR FOG AND EVEN DENSE FOG. MAY EVEN SEE FOG AGAIN MONDAY NIGHT...DEPENDING IF THE SOIL IS STILL MOIST. REGARDING TEMPERATURES THROUGH TUESDAY...850MB TEMPS ARE PROGGED TO HOLD AROUND 8C FOR MONDAY AND THEN CLIMB TO NEAR 10C BY THE END OF THE DAY TUESDAY. THESE READINGS ARE 0.5 TO 1 STANDARD DEVIATION ABOVE NORMAL. BOTH DAYS SHOULD SEE QUITE A BIT OF SUN BEING IN PROXIMITY TO THE SURFACE HIGH...THUS THINKING MIXING TO 850MB WILL NOT BE A PROBLEM. THIS RESULTS IN HIGHS MAINLY IN THE LOW 70S ON MONDAY AND LOW TO MID 70S ON TUESDAY. DID KEEP THE ROCHESTER AREA A LITTLE COOLER ON MONDAY DUE TO WETTER SOIL. LIGHT WINDS AND DRY AIR LIKELY TO RESULT IN DECENT COOLING AT NIGHT. FOLLOWED A BLEND OF MOS GUIDANCE FOR LOWS. TUESDAY NIGHT THROUGH SATURDAY...04.12Z ECMWF/GFS/CANADIAN AND ECMWF ENSEMBLES SHOW THAT THE MORE ZONAL LOOKING NORTHERN STREAM WILL BUCKLE DURING THE EXTENDED PORTION OF THE FORECAST. FOR FRIDAY AND SATURDAY...GOOD AGREEMENT EXISTS IN FAIRLY DEEP TROUGHING OVER CENTRAL CANADA...BEGINNING TO DROP DOWN TOWARDS THE FORECAST AREA. IF THE 04.00Z/04.12Z ECMWF ARE CORRECT...WE COULD BE LOOKING AT A SIGNIFICANT COOL DOWN HEADING INTO EARLY NEXT WEEK AS 850MB TEMPS PLUMMET TO -8 TO -10C. BEFORE THAT TROUGH ARRIVES...THOUGH...A SERIES OF WEAK COLD FRONTS / SYSTEMS ARE PROGGED TO COME THROUGH THE AREA. THE FIRST MOVES THROUGH LATE WEDNESDAY. INSTABILITY BUILDING AHEAD OF THIS FRONT...AIDED BY TEMPERATURES CLIMBING AT LEAST INTO THE LOW IF NOT MID 70S...REQUIRES A CHANCE OF SHOWERS AND THUNDERSTORMS. FOR THURSDAY INTO FRIDAY...THE 04.00Z/12Z ECMWF INDICATES A SHORTWAVE TROUGH MOVING WEST TO EAST THROUGH THE AREA...WHEREAS THE GFS AND CANADIAN KEEP THIS SHORTWAVE MUCH FARTHER TO THE SOUTH. FOR NOW HAVE INCLUDED A CHANCE OF SHOWERS AND THUNDERSTORMS UNTIL MODEL CONSISTENCY BECOMES BETTER. THEN FOR SATURDAY WOULD BE THE STRONGER COLD FRONT ACCOMPANYING THE UPPER TROUGH...THUS ANOTHER CHANCE OF PRECIPITATION. TEMPERATURES LOOK TO STAY NEAR OR ABOVE NORMAL...UNTIL SATURDAY. SATURDAY COULD BE TRICKY WITH HIGHS AS IT DEPENDS ON WHEN THE FRONT COMES THROUGH. 04.12Z ECMWF IS SLOWER...WHICH WOULD SUGGEST THE BLEND OF ALL AVAILABLE GUIDANCE MIGHT BE TOO COOL. WE WILL HAVE TO WAIT AND SEE. && .AVIATION...THROUGH 06Z MONDAY 1205 AM CDT SUN MAY 5 2013 BIGGEST CONCERN FOR AVIATION INTERESTS OVERNIGHT IS THE POTENTIAL FOR FOG. PREVIOUS FORECAST CYCLES WERE SUGGESTING THAT THE HIGH BOUNDRY LAYER MOISTURE OVER THE SNOW FIELD WOULD RESULT IN A BOUT OF DENSE FOG. HOWEVER...WINDS THUS FAR HAVE STAYED UP AND MAINTAINED ENOUGH MIXING TO PRECLUDE WIDESPREAD REDUCTIONS IN VISIBILITY SO FAR. THE NEWER 00Z MODEL RUNS HAVE NOW PULLED BACK ON THE FOG THREAT. HOWEVER...IF THE WINDS DO SLACKEN...WE COULD SEE THE TEMPERATURE/DEWPOINT SPREAD TIGHTEN UP. FOR NOW...WILL MAINTAIN THE DENSE FOG POTENTIAL AT THE KRST AIRPORT OVERNIGHT... BUT DID REDUCE THE NUMBER OF HOURS. AT KLSE OPTED TO IMPROVE THE VISIBILITY FROM WHAT PREVIOUS FORECASTS HAD. BEYOND TONIGHT...ONCE THE FOG THREAT ENDS BY MID-MORNING...VFR CONDITIONS WILL PREVAIL. && .HYDROLOGY... ISSUED AT 306 PM CDT SAT MAY 4 2013 AFTER SOME ISOLATED/SCATTERED RAIN SHOWERS THROUGH THIS EVENING...A FEW DAYS OF DRY WEATHER ARE EXPECTED. THESE DRY DAYS WILL BE BENEFICIAL...ALLOWING RUNOFF FROM THE RECENT RAIN AND SNOWMELT TO WORK ITS WAY THROUGH THE TRIBUTARIES INTO THE MAIN STEM OF THE MISSISSIPPI RIVER. MOST OF THE TRIBUTARIES ARE REMAINING BELOW FLOOD STAGE. MEANWHILE...ALL THE WATER EVENTUALLY LOOKS TO PUSH SOME SITES ALONG THE MISSISSIPPI RIVER RIGHT TO FLOOD STAGE. SEE THE LATEST FLOOD AND RIVER STATEMENTS FOR MORE INFORMATION. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR WIZ032-033. MN...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR MNZ079- 086>088-094-095. IA...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR IAZ008-009- 018-019. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...MW HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1011 AM EDT Sun May 5 2013 .NEAR TERM [Through Tonight]... The 12z regional RAP analysis depicted an anomalous upper level low centered over northern Mississippi, spanning much of the eastern third of the country. This morning`s subjective surface analysis places two low pressure systems and attending fronts across the Southeast. The first low/front, which were responsible for yesterday`s weather, have moved to the eastern U.S. coastline, with the low centered over southeast Georgia. The second low is positioned over northern Alabama, with a cold front extending south through western Alabama, then riding west along the northern Gulf of Mexico coastline. The second system will impact the Tri-State area later today. Expect the cool and sunny start to transition to a warm and eventually cloudy/rainy afternoon. Highs will reach the middle to upper 70s for most locations as we reside in a dry slot between fronts to start the day, with the cold center of the upper low remaining well to our northwest. Expect breezy conditions this afternoon as we will be able to tap into the strong winds aloft associated with the aforementioned low. As the surface front passes through the region later this afternoon, expect scattered light showers to accompany it. These showers will be less expansive than yesterday, and rather quick moving. They have already begun developing along the western Panhandle coastline and will spread east and expand inland through the afternoon. Expect the bulk of the rain between the 2 PM EDT and 9 PM EDT time range. Tonight, clouds and showers will clear our area to the east, and we will have another unseasonably cool night. Expect the middle 40s to be common area wide. && .SHORT TERM [Monday Through Tuesday]... A 550-dm upper low will be be positioned near the border of Northeast AL and Northwest GA at 12Z Monday and then drift south for a few hours before pulling east Monday night. By Tuesday evening, the low will be centered over the Carolinas and have filled to 560 dm. The associated surface low will be occluded through this time and remain north and then northeast of the area. In the wake of another cold front, drier air will move into the lowest levels. However, there will still be enough moisture to tap into the steep mid level lapse rates associated with the upper low to allow scattered showers to develop Monday afternoon. An isolated thunderstorm cannot be ruled out during peak heating across our GA zones north of U.S 84. The showers will be more isolated further south over the coastal counties of the FL Big Bend and Panhandle. As the upper low lifts away, PoPs will drop over our western zones Monday evening, but remain in the chance category further east across the Big Bend and our GA zones. By Tuesday, a slight chance for morning showers was maintained only for our far eastern zones in South Central GA and the eastern FL Big Bend. Temps will be well below normal, by some 10-12 degrees for afternoon highs Monday. Most areas will top out in the lower 70s, more typical for early March. Lows Monday night will not be as chilly as tonight`s, but will still be 6-8 degrees below normal, generally within a degree or two of 50. Tuesday will see more sunshine which will allow temps to warm into the mid to upper 70s which is still 8-10 degrees below normal. && .LONG TERM [Tuesday Night through Saturday]... In the wake of the upper low, we will dry out an warm up quite a bit. No major weather systems are forecast to impact the local area, and temperatures will warm to seasonal averages by mid week. && .AVIATION [Beginning 14Z Sunday]... VFR conditions are anticipated for the duration of the TAF. Gusty winds will be the main forecast concern today. Expect gusts to 30 knots near our northwestern terminals, and up to 15 knots further southeast. Light rain will fall from mid-level cloudiness this afternoon and should not result in any category restrictions. && .MARINE... The lull in advisory level winds will be short lived this morning as another cold front approaches from the west. Expect another surge in westerly winds later today before falling to below advisory criteria tomorrow morning. Cautionary conditions are forecast through Monday, remaining light to moderate out of the west or northwest from Monday night through mid week. && .FIRE WEATHER... Drier air is still expected to move into the area for today and Monday, but conditions will not be dry enough for Red Flag concerns. However, dispersions are expected to be quite high across much of North Florida today and Monday. && .HYDROLOGY... With only light rainfall amounts anticipated through mid week, we do not expect any meaningful river or creek rises. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 78 47 72 51 77 / 20 10 30 30 10 Panama City 74 52 73 55 76 / 20 10 20 20 10 Dothan 72 45 71 50 74 / 30 10 40 20 10 Albany 75 47 72 50 76 / 30 10 40 40 10 Valdosta 76 47 72 51 75 / 20 10 30 40 20 Cross City 78 49 75 50 77 / 10 20 20 30 20 Apalachicola 71 50 72 55 73 / 20 10 20 20 10 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...Small Craft Advisory until 5 AM EDT Monday for Gulf of Mexico waters from Apalachicola to Destin and out to 60 NM. Small Craft Advisory from 5 PM this afternoon to 5 AM EDT Monday for Gulf of Mexico waters from Apalachicola to the Suwannee River and out to 60 NM. && $$ NEAR TERM...Harrigan SHORT TERM...Wool LONG TERM...Harrigan AVIATION...Harrigan MARINE...Harrigan/Wool FIRE WEATHER...Gould HYDROLOGY...Wool
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
930 AM EDT SUN MAY 5 2013 .DISCUSSION... ...ROUGH SURF/HIGH RIP CURRENT RISK TODAY... CURRENTLY-THIS AFTERNOON...REMOVED RAIN CHANCES FROM THE FORECAST AS RADAR TRENDS WERE INDICATING THAT THE STORMS IN THE ATLANTIC WERE EAST OF OUR COASTAL WATERS AND WILL CONTINUE TO MOVE AWAY THIS AFTERNOON. VISIBLE SATELLITE IMAGERY LOOP SHOWS PARTLY CLOUDY SKIES FROM SOUTH BREVARD OSCEOLA COUNTIES NORTH. TO THE SOUTH...CUMULUS AND STRATOCUMULUS MOVING OFF TO THE SOUTHEAST. MORE CUMULUS AND STRATOCUMULUS TO FORM AS DAYTIME HEATING WARMS UP THE LOWEST LAYERS. MORNING SOUNDINGS FROM THE FLORIDA UPPER AIR SITES SHOW A DRY LAYER STARTING AROUND 900MB/APPROX 3500 FEET AND ABOVE. SURFACE ANALYSIS SHOWING WEAK HIGH PRESSURE WORKING ITS WAY ACROSS THE EASTERN GULF OF MEXICO AND CENTRAL FLORIDA. THE NORTHWEST TO WEST WIND WILL KEEP TEMPERATURES AND HUMIDITY LEVELS COMFORTABLE THIS AFTERNOON. PREVIOUS ZONE DISCUSSION TONIGHT...WEAK RIDGING BEHIND THE FRONT WILL KEEP SKIES MOSTLY CLEAR EARLY. ANOTHER WEAK FRONTAL TROUGH WILL PUSH INTO THE PENINSULA AFTER MIDNIGHT. THE AIR MASS WILL BE QUITE DRY SO EXPECT JUST A NARROW BAND OF CLOUDINESS WITH THIS BOUNDARY. OVERNIGHT LOWS WILL BE A LITTLE BELOW NORMAL IN THE UPPER 50S TO LOWER 60S. MON-MON NIGHT...LARGE EXPANSIVE UPPER LOW OVER THE TENNESSEE VALLEY IS FORECAST TO SLOWLY MOVE EAST INTO THE CAROLINAS THROUGH THE END OF THIS PERIOD. ONLY WEAK ENERGY ALOFT ASSOCIATED WITH THIS FEATURE WILL TRAVERSE EAST CENTRAL FLORIDA. A WEAK FRONTAL TROUGH WILL MOVE ACROSS THE COVERAGE WARNING AREA AND PROVIDE A SMALL THREAT FOR SHOWERS...MAINLY SOUTH OF THE I-4 CORRIDOR. YET ANOTHER FEATURE IS FORECAST TO DROP INTO NORTH-CENTRAL FLORIDA OVERNIGHT. WILL KEEP POPS AT 20 PERCENT OR LESS. WESTERLY WINDS INCREASING TO 10-15 MPH IN THE AFTERNOON. HIGHS IN THE UPPER 70S TO AROUND 80 DEGREES NORTH OF THE I-4 CORRIDOR WITH LOWER 80S FURTHER SOUTHWARD. LOWS MAINLY IN THE UPPER 50S...EXCEPT AROUND 60 DEGREES TO LOWER 60S ACROSS THE SPACE/TREASURE COASTS AND ORLANDO METRO. TUE-TUE NIGHT...THE PREVIOUSLY MENTIONED UPPER LOW WILL GRADUALLY WEAKEN AS IT BEGINS TO MOVE UP THE MID ATLANTIC COAST. CLOSER TO HOME THE NEXT WEAK FRONTAL TROUGH WILL MOVE FROM NORTH-CENTRAL FLORIDA THROUGH EAST CENTRAL FLORIDA DURING THE DAY. AGAIN ISOLATED SHOWERS WILL BE POSSIBLE THROUGH THE DAY BUT EXPECT PRECIPITATION TO BE LIGHT AS MOISTURE VALUES ARE POOR. MAINLY WESTERLY WINDS AGAIN INCREASING TO 10-15 MPH IN THE AFTERNOON. HIGHS NEAR 80 DEGREES TO LOWER 80S MOST LOCATIONS...EXCEPT A FEW MIDDLE 80S POSSIBLE ACROSS OKEECHOBEE COUNTY AND SOUTHERN OSCEOLA COUNTY. OVERNIGHT LOWS ONCE AGAIN IN THE MIDDLE TO UPPER 50S WITH A FEW LOWER 60S POSSIBLE ALONG THE TREASURE COAST AND ORLANDO METRO. WED-SAT...THE UPPER LOW CONTINUES TO WEAKEN AS IT SLOWLY MOVES UP THE ATLANTIC SEABOARD...FINALLY OPENING UP INTO A TROUGH AND MOVING INTO THE NORTH ATLANTIC DURING THE DAY ON FRI. MAINLY ZONAL WINDS ALOFT OVER THE AREA WITH ONLY A FEW SUBTLE IMPULSES EMBEDDED WITHIN. SLIGHT SHORTWAVE RIDGING BEGINS TO INCREASE OVER THE REGION ON SAT. THE LOCAL SURFACE PRESSURE GRADIENT REMAINS RATHER WEAK AS HIGH PRESSURE OVER THE AREA INITIALLY MOVES INTO THE WESTERN ATLANTIC ON THU WITH RIDGING EXTENDING ACROSS THE CENTRAL PENINSULA INTO THE WEEKEND. LIGHT WESTERLY SURFACE FLOW ON WED WILL GIVE WAY TO AFTERNOON SEA BREEZES EACH DAY THU-SAT. ENOUGH MOISTURE MAY CREEP BACK INTO THE AREA ON SAT FOR A FEW LATE DAY STORMS ACROSS THE INTERIOR. BELOW NORMAL MAX/MIN TEMPERATURES WILL CONTINUE INTO WED BEFORE A GRADUAL WARMING TREND COMMENCES THU LASTING INTO THE WEEKEND. && .AVIATION... VFR. BROKEN-SCATTERED VFR FROM KVRB SOUTH THE REST OF THE MORNING AS && .MARINE... CURRENTLY-THIS AFTERNOON...BUOY 009 RECORDING NORTHWEST WINDS AROUND 20 KNOTS AND 7 FOOT SEAS WITH LARGE LONG PERIOD EASTERLY SWELLS BEING THE PRIMARY COMPONENT TO SIGNIFICANT WAVE HEIGHTS. THE TWO NEARSHORE SCRIPPS BUOYS WERE RECORDING 4 TO 5 FOOT SEAS WITH A 2 FOOT LONG PERIOD EASTERLY SWELL. WILL HAVE TO FOLLOW BUOY WAVE HEIGHT TRENDS AND MAKE A LAST MINUTE CALL ON WHETHER TO EXTEND OR DROP THE SMALL CRAFT ADVISORY AT MIDDAY. PREVIOUS MARINE DISCUSSION CURRENTLY-TONIGHT...THE NORTHERN OFFSHORE LEG STILL HAS SOUTHEAST WINDS AROUND 20 KNOTS BUT THE GFS AND LATEST RAP SHOW SURFACE LOW OVER NORTHEAST FLORIDA MOVING FARTHER AWAY AND WINDS WEAKENING BY FORECAST ISSUANCE TIME. WEST/NORTHWEST WINDS 10 TO 15 KNOTS EXPECTED MOST OF THE DAY AND INTO TONIGHT. SEAS ARE STILL ELEVATED ESPECIALLY IN THE NORTH DUE TO EAST/NORTHEAST SWELLS. THIS WILL LIKELY MAKE INLETS HAZARDOUS DURING THE OUTGOING TIDE THIS MORNING. THEREFORE...WILL CARRY A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS THIS MORNING OVER ALL THE WATERS. MON-MON NIGHT...WEAK HIGH PRESSURE WILL BUILD INTO THE AREA BEHIND THE MOST RECENT WEAK FRONTAL TROUGH. WESTERLY WINDS THROUGH THIS TIME WITH SPEEDS NEAR 10 KTS NEAR SHORE AND OCCASIONALLY 10-15 KTS OFFSHORE. INCREASING LARGE EASTERLY SWELL WILL KEEP SEAS 3-5 FT NEAR SHORE AND 5-6 FT OFFSHORE. CAUTIONARY STATEMENTS WILL BE NECESSARY FOR OFFSHORE LEGS DUE TO THE SWELL. TUE-THU...ANOTHER WEAK TROUGH PASSES THROUGH THE AREA ON TUE BEFORE HIGH PRESSURE BUILDS BACK INTO THE REGION EMERGING INTO THE WESTERN ATLANTIC ON THU. MAINLY A WESTERLY COMPONENT OF WIND BUT MAY SEE WINDS BACK TO THE E/ESE ALONG THE COAST BY WED/THU WITH EAST COAST SEA BREEZE FORMATION. WIND SPEEDS 10-12 KTS NEAR SHORE WITH PERIODS AROUND 15 KTS OFFSHORE. SEAS TO SUBSIDE DURING THIS TIME WITH INITIAL 3-5 FT SEAS FALLING BACK 3 FT OR LESS BY EARLY THU. && .FIRE WEATHER... TODAY...A FEW HOURS OF RH 30 TO 35 PERCENT SHOULD OCCUR OVER THE INTERIOR NORTH THIS AFTERNOON. WEST WINDS NEAR 15 MPH WILL BE GUSTY TO AROUND 20 MPH AT TIMES. HOWEVER...THE ERC VALUES ARE TOO LOW AFTER RECENT RAINS FOR RED FLAG CRITERIA TO OCCUR. MON-THU...GUIDANCE CONTINUES TO SHOW MIN RH VALUES DROPPING INTO THE M-U30S OVER THE INTERIOR EACH AFTERNOON. WINDS SHOULD NOT BE A HUGE CONCERN...AND FORTUNATELY...ERC VALUES HAVE DROPPED SIGNIFICANTLY FROM LAST WEEK`S RAINFALL. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 12 NOON TODAY FOR ALL OF THE COASTAL WATERS. && $$ UPDATES/AVIATION...WIMMER RADAR/IMPACT WX....CRISTALDI
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
734 AM EDT SUN MAY 5 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 402 AM EDT SUN MAY 5 2013 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG STRETCHING FM SE CANADA INTO THE UPR GRT LKS TO THE N OF CLOSED LO OVER THE SRN MS RIVER VALLEY THAT WAS RESPONSIBLE FOR THE WINTER WX THE PAST COUPLE OF DAYS. THE 00Z GRB RAOB AND ESPECIALLY THE APX RAOB SHOW A VERY DRY AIRMASS UNDER THIS RDG...WITH THE 00Z H85 DEWPT DEPRESSION AS HI AS 24C/PWAT JUST 0.24 INCH OR 49 PCT OF NORMAL AT APX. BUT THERE IS STILL A RIBBON OF DEEPER MSTR SOME -SHRA EXTENDING NNWWD FM THE CLOSED LO TO THE S INTO MN/ADJOINING ONTARIO. THE 00Z INL RAOB SHOWS A NEARLY SATURATED PROFILE AND 00Z PWAT OF 0.83 INCH...188 PCT OF NORMAL. ALTHOUGH THERE ARE SOME HI CLDS OVER THE E...THAT AREA IS DOMINATED BY THE DRY AIRMASS SHOWN ON THE APX RAOB. WITH H85 TEMPS UP TO 10C...MAX TEMPS YDAY REACHED THE 70S OVER THE SCENTRAL AND ERN CWA WHERE THE DRY AIR ALLOWED FOR QUITE A BIT OF SUNSHINE AND LAKE COOLING WAS ABSENT IN THE NLY FLOW S OF HI PRES CENTERED OVER NW ONTARIO. ALTHOUGH THE DRY AIR ALF HAS PUSHED INTO THE WRN CWA PER THE LATEST RUC ANALYSIS SDNGS...ENUF LLVL MSTR LINGERS THERE UNDER SHARP INVRN AT H9 TO SUPPORT LO CLDS/FOG OVER THE WRN CWA FM THE KEWEENAW THRU GOGEBIC COUNTY. SINCE THE 00Z YPL RAOB SHOWS SOME MSTR BTWN H9-825 EVEN CLOSE TO THE ONTARIO HI CENTER...THERE IS QUITE A BIT OF LO CLD EXTENDING WELL N OF LK SUP TO THE HI PRES RDG AXIS. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LO CLD TRENDS/IMPACT ON TEMPS. POTENTIAL FOR LOW RH OVER THE E/IMPACT ON FIRE WX CONCERNS THIS AFTN IS THE FOCUS THERE. TODAY...UPR RDG AXIS/MID LVL DRY AIR WL REMAIN DOMINANT. ALTHOUGH SFC HI PRES OVER NW ONTARIO IS PROGGED TO DRIFT SLOWLY S TOWARD LK SUP...THE NNW FLOW IN ADVANCE OF THIS HI...ALBEIT LGT...WL LIKELY ACT TO HOLD LO CLDS IN PLACE OVER MUCH OF THE NW HALF OF THE CWA DESPITE THE ONSET OF DIURNAL HEATING THAT WOULD NORMALLY MIX OUT THIS LLVL MSTR. IN FACT...COOL ADVECTION OFF THE CHILLY WATERS OF LK SUP WL TEND TO OFFSET THE DIURNAL HEATING AND MAINTAIN A LLVL INVRN/POTENTIAL FOR MORE PERSISTENT LO CLDS IN THIS AREA AS HI TEMPS HOLD IN THE 40S NEAR THE SHORE. OVER THE E HALF OF THE CWA...A LGT S FLOW WL PREVAIL ARND SFC HI PRES OVER SE ONTARIO. ALTHOUGH THERE MAY BE MODERATION NEAR THE BAY OF GREEN BAY/ LK MI WITH A LK BREEZE...H85 TEMPS NEAR 10C/MIXING TO H8-85 ON NAM/ GFS FCST SDNGS WITH A GOOD DEAL OF SUNSHINE SUPPORT HI TEMPS TOPPING OUT IN THE 70S AWAY FM THE LK COOLING. WITH SFC DEWPTS MIXING OUT TOWARD 35 OVER THE INTERIOR...MIN RH WL LIKELY FALL AS LO AS ABOUT 25 PCT. FORTUNATELY...THE WINDS WL BE LGT...SO NO FIRE WX HEADLINES ARE NECESSARY. TONIGHT...WITH HI PRES FCST TO SHIFT OVHD AND LGT WINDS...EXPECT TEMPS TO DIP INTO THE 30S...FALLING MOST SHARPLY OVER THE E AND SCENTRAL...WHERE MUCH DRIER AIR /PWAT NEAR 0.5 INCH/ WL LINGER. SINCE MORE LLVL MSTR WL BE LINGERNING OVER THE W/NCENTRAL... RETAINED A MENTION OF FOG IN THIS AREA OVERNGT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 402 AM EDT SUN MAY 5 2013 WITH THE CUTOFF LOW SITUATED OVER THE SOUTHEAST CONUS AND THE NORTHERN JET STREAM WELL TO THE NORTH OF THE AREA IN CANADA...A QUIET START TO THE WORK WEEK IS EXPECTED WITH ABOVE NORMAL TEMPERATURES OVER MUCH OF THE AREA. MONDAY AND TUESDAY WILL BE DOMINATED BY HIGH PRESSURE AT THE SURFACE. EXPECT MOSTLY CLEAR SKIES FOR MUCH OF THIS PERIOD...BUT THERE COULD BE SOME HIGH BASED DIURNAL CU DEVELOPING OVER THE INTERIOR WEST DUE TO A POCKET OF 800-750MB MOISTURE. A FEW MODELS HINT AT SOME SHOWER DEVELOPMENT...BUT WITH THE HIGH BASES AND LIMITED MOISTURE KEEPING MLCAPE VALUES BELOW 150 J/KG...THINK IT WILL JUST BE CU. THE SUNSHINE WILL ALLOW FOR AMPLE MIXING...TO 800-775MB...AND LEAD TO HIGHS IN THE LOWER 70S AWAY FROM THE GREAT LAKES. LAKE BREEZES ON BOTH DAYS WILL KEEP TEMPERATURES COOLER NEAR THE GREAT LAKES. DID TRY TO MIX OUT DEWPOINTS A LITTLE MORE THAN THE MODELS HAVE INDICATED BASED OFF WHAT OCCURRED YESTERDAY. FORTUNATELY...WITH LIGHT WINDS UNDER THE HIGH...IT WILL LIMIT FIRE WX CONCERNS OVER THE SOUTH CENTRAL AND EAST EVEN THOUGH FFMC VALUES ARE ON THE INCREASE AND ARE OR BECOMING HIGH. PATCHY GROUND FOG IS POSSIBLE OVER THE KEWEENAW AND INTERIOR WEST MONDAY NIGHT WITH THE CLEAR SKIES AND LOW LEVEL COOLING BY LINGERING SNOW COVER. FARTHER EAST...DRIER AIR IN PLACE WILL LIMIT THE FOG POTENTIAL. OVER THE GREAT LAKES...MODELS ARE HINTING AT FOG DEVELOPMENT WITH THE LIGHT WINDS ON MONDAY. BUT DEWPOINTS AREN/T EXTREMELY HIGH AND WITH DRY AIR ALOFT IT WON/T GET MUCH HELP FROM THE LAND. WITH THAT BEING SAID...IF IT DOES DEVELOP...THE LIGHT WINDS WOULD LEAD TO SLOW MOVEMENT AND IT LINGERING INTO WEDNESDAY. COULD SEE SOME PATCHY GROUND FOG OVER THE FAR WEST LATE TUESDAY NIGHT...BUT CONFIDENCE IS TOO LOW TO ADD AT THIS POINT. THE HIGH PRESSURE WILL BEGIN TO GIVE WAY ON WEDNESDAY...AS AN UPPER TROUGH OVER THE WEST COAST SLIDES INTO THE PLAINS AND A SHORTWAVE SLIDES THROUGH THE NORTHERN STREAM AND PRODUCES A SURFACE LOW THAT MOVES INTO NORTHWEST QUEBEC ON WEDNESDAY. A COLD FRONT ASSOCIATED WITH THIS LOW WILL TRY TO DROP THROUGH THE AREA ON WEDNESDAY AFTERNOON AND NIGHT. WITH THE UPPER TROUGH MOVING INTO THE PLAINS...IT MAY PROVIDE ENOUGH MOISTURE TO PRODUCE SOME SHOWERS. BUT THE MODELS DIFFER ON THE NORTHEASTWARD EXTENT OF THE MOISTURE FROM THE UPPER TROUGH. THE 12Z ECMWF/GEM KEEP THE MOISTURE FARTHER TO THE WEST...WHILE THE 18Z GFS PULLS IT INTO THE UPPER GREAT LAKES. LATEST 00Z GFS/GEM RUNS HAVE TRENDED TOWARDS THE ECMWF IDEA. BASED ON THE EXISTING DRY AIR MASS AND LIMITED MOISTURE RETURN...WOULD TEND TO SIDE WITH THE DRIER IDEA AND WILL ONLY HAVE SLIGHTS OR LOW CHANCE POPS FOR THE PASSAGE OF THE FRONT. BEHIND THE FRONT...ANOTHER NORTHERN STREAM SHORTWAVE MAY AFFECT THE AREA ON FRIDAY NIGHT INTO SATURDAY AND BRING ANOTHER POTENTIAL FOR RAIN. BUT AGAIN...MOISTURE LOOKS TO BE THE CONCERN FOR THAT PERIOD UNLESS THE LOW MOVING THROUGH THE LOWER GREAT LAKES MOVES FARTHER TO THE NORTH. TEMPERATURES WED INTO SATURDAY LOOK TO BE COOLER THAN THE FIRST PART OF THE WORK WEEK...BUT STILL NORMAL OR VERY SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 733 AM EDT SUN MAY 5 2013 EXPECT LO CLDS/FOG AT MAINLY THE WRN SITES OF CMX AND ESPECIALLY IWD TO LINGER THRU THIS MRNG BEFORE DIURNAL HEATING MIXES OUT THE LLVL MSTR DURING THE AFTN. WHERE THE LLVL NNE FLOW PRESENTS THE GREATEST UPSLOPE COMPONENT AT IWD...CONDITIONS WL BE AS LO AS LIFR TO VLIFR...AND THE LO CLDS WL LINGER LONGER THRU MUCH OF THE DAY. ALTHOUGH SOME LO CLDS COULD IMPACT SAW EARLY IN THE TAF PERIOD... THIS SITE APPEARS TO BE TOO DEEP INTO THE DRY AIR SHOWN ON THE 00Z GRB/APX RAOBS TO SEE PERSISTENT LO CLD/IFR WX. EXPECT FOG/IFR CONDITIONS TO REDVLP TNGT AS HI PRES/LGT WINDS DOMINATE THE AREA WITH LINGERING LLVL MSTR. THE LOWEST CONDITIONS SHOULD AGAIN PREVAIL AT IWD AND CMX...WHERE MORE LLVL MSTR WL LINGER. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 402 AM EDT SUN MAY 5 2013 A QUIET PERIOD OF WEATHER IS EXPECTED THROUGH THE PERIOD...WITH THE WINDS LIKELY STAYING BELOW 25KTS. HIGH PRESSURE THAT HAS SETUP OVER THE AREA WILL REMAIN THROUGH THE FIRST PART OF THE WORK WEEK AND LEAD TO LIGHT WINDS. THEN...A COLD FRONT DROPPING SOUTHEAST ACROSS THE UPPER GREAT LAKES ON WEDNESDAY INTO WEDNESDAY NIGHT WILL BRING A WIND SHIFT BUT ONLY 10-20KT WINDS. WEAK HIGH PRESSURE WILL MOVE OVER NORTHERN LAKE SUPERIOR FOR THURSDAY INTO THURSDAY NIGHT AND DIMINISH THE WINDS. && .HYDROLOGY... ISSUED AT 402 AM EDT SUN MAY 5 2013 HYDROLOGY CONCERNS WILL REMAIN OVER THE COMING DAYS...UNTIL THE REMAINING SNOW PACK MELTS OVER THE NORTHWESTERN THIRD OF UPPER MICHIGAN. VISIBLE SATELLITE AND MODIS IMAGERY TODAY STILL SHOWS SNOW REMAINING IN THE HIGHER TERRAIN LOCATIONS OF THE HURON MOUNTAINS AND THE KEWEENAW PENINSULA. FARTHER WEST...THE 10 PLUS INCHES OF WET SNOW WILL ALSO HELP KEEP THE POTENTIAL OF RISING RIVER LEVELS IN PLACE. DID SEE RISES AT SOME OF THE SITES OVER THE WEST /RKLM4 AND ESPECIALLY TRRM4/ WITH THE WARMER TEMPERATURES YESTERDAY AND WOULD EXPECT THAT TO CONTINUE TODAY INTO THE FIRST PART OF THE WORK WEEK. THE STURGEON RIVER AT ALSTON AND CHASSELL...THE MICHIGAMME RIVER AROUND WITCH LAKE...AND THE PAINT RIVER NEAR CRYSTAL FALLS WILL REMAIN CONCERNS INTO AT LEAST EARLY NEXT WEEK...AND IN THE CASE OF THE MICHIGAMME RIVER PERHAPS WELL INTO THE COMING WEEK. BUT OTHERWISE RIVER LEVELS CONTINUE TO COME DOWN DESPITE SOME RECENT HEAVY PRECIP THAT IMPACTED MAINLY THE W HALF OF UPR MI. FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND ADVISORIES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...KC MARINE...SRF HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
705 AM EDT SUN MAY 5 2013 .SYNOPSIS... COOL HIGH PRESSURE WILL EXTEND ALONG THE NORTHEAST AND MID ATLANTIC COAST THROUGH MONDAY. A STRONG UPPER LOW WILL TRACK SLOWLY EASTWARD ACROSS THE DEEP SOUTH AND CAROLINAS THROUGH TUESDAY. && .NEAR TERM /THROUGH MONDAY NIGHT/... AS OF 300 AM SUNDAY... FOR TODAY: RAIN CHANCES WILL SLOWLY INCREASE FROM SW TO NE LATER TODAY... HOWEVER IT LOOKS LIKE THE HEAVIER RAIN IS LIKELY TO HOLD OFF UNTIL LATE. THE UPPER LOW IS CURRENTLY SPINNING NEAR MEMPHIS... WHILE NC REMAINS BENEATH A MID LEVEL COL AREA BORDERED BY THE PERSISTENT BLOCKING HIGH OVER THE ERN GREAT LAKES... BROAD WEAK LOW PRESSURE OUT OVER THE ATLANTIC... AND THE POTENT VORTEX OVER THE LOWER MISS VALLEY. STRONG MOISTURE TRANSPORT CONTINUES TO DRIVE UP OVER GA/SC INTO THE SRN APPALACHIANS WITH A 45 KT SOUTHEASTERLY LOW LEVEL JET ORTHOGONAL TO THE SLOPES OVER SW NC... LEADING TO MAXIMUM POTENTIAL TERRAIN UPGLIDE HERE AND A HIGH THREAT OF HEAVY RAIN AND FLOODING ISSUES TO OUR WEST TODAY. ADDING TO THIS LOW-LEVEL-ROOTED MECHANICAL LIFT IS STRONG UPPER DIVERGENCE WHICH WILL PEAK OVER WRN NC TODAY... ALTHOUGH THE SLOW MOVEMENT AND THE START OF GRADUAL WEAKENING OF THIS VORTEX WILL MINIMIZE MID LEVEL DPVA AND HEIGHT FALLS. SO WHILE SOME OF THIS SHIELD OF HEAVIER RAIN MAY WORK INTO THE FAR SWRN CWA THIS AFTERNOON... GIVEN THE FOCUS OF STRONGER LIFT AND MOISTURE FLUX LARGELY OVER WRN NC... EXPECT MORE IN THE WAY OF VERY PATCHY LIGHT RAIN AND DRIZZLE OVER MUCH OF CENTRAL NC THROUGH TODAY. THIS IS FURTHER SUPPORTED BY MODEL TRENDS SHOWING A SLOWING OF THE NE PROGRESS OF THE HEAVY RAIN SHIELD TODAY... AS WELL AS THE LATEST RAP AND CONVECTION-ALLOWING WRF RUNS. WILL LOWER POPS AND QPF AND DELAY THE ARRIVAL OF HIGHER CHANCES UNTIL LATE TODAY. THICKNESSES ABOUT 20-25 METER BELOW NORMAL COMBINED WITH THE BRISK ENE WINDS AND CONSIDERABLE CLOUD COVER SUPPORT COOL HIGHS OF 58-68. FOR TONIGHT: WE SHOULD FINALLY SEE THE MORE WIDESPREAD RAIN WORK INTO CENTRAL NC FROM THE SW. THE VORTEX TO OUR SW WILL BEGIN TO SLOWLY FILL AS IT WOBBLES ACROSS NRN AL TO NEAR CHATTANOOGA TONIGHT. AS IT APPROACHES... THE OCCLUDED SURFACE FRONT WILL PIVOT NE INTO SW NC ACROSS SC... WHILE THE INTENSE PLUME OF ATLANTIC MOISTURE (WITH PRECIP WATER OVER 150 PERCENT OF NORMAL) STREAMING OVER SC INTO WRN NC GRADUALLY TRANSLATES TO THE NNE. EXPECT A SLOW BUT STEADY INCREASE IN POPS FROM VERY LATE AFTERNOON THROUGH TONIGHT IN CENTRAL NC FROM SW TO NE... TRENDING UP TO CATEGORICAL ACROSS THE SOUTH AND WEST WITH LIKELY POPS IN THE NE. TOUGH CALL ON AMOUNTS THROUGH TONIGHT... CONSIDERING THAT THE MID LEVEL VORTEX WILL BE WEAKENING AND THUS THE DYNAMIC FORCING WILL BE ON THE DECREASE... PLUS THE NORTHWARD SHIFT OF THE SOUTHEASTERLY LOW LEVEL JET INTO NW NC AND SW VA WILL ACCORDINGLY PLACE THE BEST LOW LEVEL CONVERGENCE AND MOISTURE TRANSPORT JUST WEST OF THE FORECAST AREA. WILL FORECAST AMOUNTS UP TO A HALF INCH OVER THE FAR SRN AND FAR WRN CWA INCLUDING LAURINBURG INTO SOUTHERN PINES AND THE TRIAD TO THE SW... WHILE AREAS TO THE NORTH AND EAST SHOULD SEE MUCH LOWER AMOUNTS... GENERALLY A TENTH INCH OR LESS THROUGH TONIGHT AS WE SIMPLY WON`T SEE QUITE THE FORCING FOR ASCENT NOR HIGHER PW FLUX IN THE NE CWA OVERNIGHT. THE CLOUDS AND WINDS SHOULD LIMIT COOLING AND LOWER THE DIURNAL TEMP SPREAD... THUS HAVE NUDGED UP LOWS SLIGHTLY TO 54-60. FOR MONDAY/MONDAY NIGHT: THE MID LEVEL VORTEX IS EXPECTED TO REMAIN POTENT BUT STEADILY WEAKEN AS IT MEANDERS AROUND NE AL MONDAY THEN EASES INTO EAST CENTRAL GA MONDAY NIGHT AS LOBES OF VORTICITY ROTATE AROUND IT AND DRIVE ITS MOVEMENT. MODELS DIFFER ON THE EVOLUTION OF SURFACE FEATURES BUT IT APPEARS MOST LIKELY THAT THE PRIMARY LOW WILL WEAK OVER TN WHILE A SECONDARY TRIPLE-POINT LOW FORMS OVER THE CENTRAL NC/SC BORDER AREA... NEAR THE CROOK OF A MID LEVEL DRY SLOT PUNCHING INTO SC. IF THIS LOW WANDERS UP TOWARD CLT AS MOST OPERATIONAL MODELS SUGGEST... THE MID LEVEL DRY SLOT SHOULD SHIFT INTO FAR SRN NC WHILE THE BEST LOW LEVEL MOISTURE FEED AND UPPER DIVERGENCE (AND HENCE THE GREATEST ASCENT AND LOW LEVEL MOISTURE TRANSPORT) SHIFT INTO EAST-CENTRAL/NE/NORTH-CENTRAL NC MONDAY... AND EVENTUALLY UP INTO VA MONDAY NIGHT. THIS SUPPORTS THE GENERAL TREND OF EARLIER FORECAST OF SHIFTING THE CATEGORICAL POPS NORTHWARD THROUGH NC DURING THIS PERIOD. INSTABILITY REMAINS MARGINAL BUT DOES INCREASE ACROSS THE SOUTH MONDAY/MONDAY NIGHT WITH THE ARRIVAL OF THE DRY SLOT AND RISING MID LEVEL LAPSE RATES TO OVER 6.75 C/KM... AND THE NAM/GFS TAKE MLCAPE NEAR 1000 J/KG MONDAY AFTERNOON. WILL NEED TO RETAIN A MENTION OF AT LEAST ISOLATED STORMS... MAINLY SOUTH OF HIGHWAY 64 AND MAINLY IN THE AFTERNOON/EVENING. THE WIND PROFILE IS NOT TEXTBOOK BUT 0-6KM SHEAR DOES REACH 30-40 KTS WITH A CURVED 0-3 KM HODOGRAPH AND 0-1 KM SHEAR OF 20-25 KTS... SO WE COULD SEE A STRONG STORM OR TWO. ADDITIONAL RAINFALL AMOUNTS COULD APPROACH AN INCH ESPECIALLY IN THE NORTHERN HALF ACCOMPANYING THE AXIS OF MORE STEADY RAIN. THE DIURNAL SPREAD SHOULD AGAIN BE MUCH LOWER THAN USUAL... ALTHOUGH A FEW ANTICIPATED BREAKS IN THE CLOUDS IN THE SOUTH MONDAY AFTERNOON SHOULD CAUSE A SPIKE IN TEMPS. HIGHS FROM 61 NW TO 72 SE. LOWS 53 SW TO 59 NE. -GIH && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 315 AM SUNDAY... TUESDAY... THE UPPER LOW OVER THE SAVANNAH RIVER BASIN WILL LIFT VERY SLOWLY NORTHEAST ACROSS THE CAROLINAS TUESDAY. HEAVIER RAIN ASSOCIATED WITH THE WARM CONVEYOR BELT AND DEEP MOIST AXIS WILL SHIFT NORTH ACROSS VA WITH THE OCCLUDED FRONT...AS A DRY SLOT WORKS ITS WAY AROUND THE EAST SIDE OF THE UPPER LOW. COOLING ALOFT AND STEEPENING MID LEVEL LAPSE RATES (TO AROUND 7 C/KM) SHOULD STILL SUPPORT AT LEAST SCATTERED SHOWERS AND STORMS...PARTICULARLY OVER THE COASTAL PLAIN WHERE HEIGHT FALLS ALOFT AND LOW LEVEL CONVERGENCE WILL BE MAXIMIZED AHEAD OF THE UPPER LOW AND ASSOCIATED BAGGY SURFACE LOW. WHILE FAIRLY WIDESPREAD CLOUD COVER MAY INHIBIT HEATING...STRONG DEEP LAYER SHEAR AROUND 40KT ON THE EASTERN PERIPHERY OF THE UPPER LOW COULD STILL SUPPORT SOME STORM ORGANIZATION AND ENHANCE THE THREAT OF HAIL IF INSTABILITY CAN DEVELOP...MAINLY OVER THE NORTHERN COASTAL PLAIN. THE THREAT SEVERE WEATHER APPEARS TO BE LOW...HOWEVER. SOME BREAKS IN CLOUD COVER APPEAR MORE LIKELY OVER THE EAST TUESDAY...THOUGH GUIDANCE STILL ONLY INDICATES HIGHS AROUND 70 OVER THE COASTAL PLAIN. OVER THE WEST...DEEPER MOISTURE WRAPPED AROUND THE NORTHWEST SIDE OF THE UPPER LOW WILL MAINTAIN MOSTLY CLOUDY SKIES AND MAY KEEP TEMPS FROM RISING OUT OF THE LOWER 60S. TUESDAY NIGHT AND WEDNESDAY... THE UPPER LOW WILL MOVE OVERHEAD TUESDAY NIGHT AND OFF THE VA TIDEWATER REGION DURING THE DAY WEDNESDAY. FORCING FOR ASCENT WILL BECOME LESS FAVORABLE BEHIND THE UPPER LOW AS THE DEEP LAYER FLOW EXHIBITS MORE BACKING AND SUBSIDENCE BEGINS TO SET IN. SOME SHOWERS ARE POSSIBLE IN THE WRAP AROUND MOISTURE LIKELY TO ENCOMPASS VA WEDNESDAY...SOME OF WHICH MAY LINGER OF DRIFT SOUTH INTO THE NORTHERN PORTION OF THE CWA. THERMODYNAMIC PROFILES SUGGEST SOME WEAK INSTABILITY AND A FEW STORMS WILL BE POSSIBLE...THOUGH AGAIN THE THREAT OF SEVERE IS LOW. LOWS IN THE MID 50S WEDNESDAY MORNING SHOULD REBOUND INTO THE LOW TO MID 70S AREAWIDE BY WEDNESDAY AFTERNOON. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... AS OF 315 AM SUNDAY... HEIGHTS WILL CONTINUE TO SLOWLY RISE THURSDAY THROUGH FRIDAY IN THE WAKE OF THE DEPARTING UPPER LOW AND AHEAD OF SOUTHERN STREAM ENERGY MOVING OUT OF THE SOUTHWESTERN US. WITH SHORTWAVE RIDGING ALOFT OVERHEAD...DRY CONDITIONS AREA EXPECTED WITH TEMPS MODERATING INTO THE UPPER 70S AND LOWER 80S. MEDIUM RANGE MODELS THEN SHOW THE POTENTIAL FOR THE SPLIT FLOW PATTERN TO AMPLIFY NEXT WEEKEND...WITH A CUT OFF LOW OVER THE SOUTHWESTERN US AND TROUGHING FROM THE NORTH CENTRAL US TO THE EAST COAST. A COLD FRONT OVER THE MIDWEST STATES FRIDAY SHOULD EVENTUALLY PUSH EAST ACROSS THE MOUNTAINS BY SUNDAY...THOUGH THERE IS QUITE A BIT OF DISAGREEMENT BETWEEN THE ECMWF AND GFS ON THE EVOLUTION OF ENERGY OVER THE CENTRAL US AND THE PROGRESSION OF THE FRONT. PREFER TO MAINTAIN THE CHANCE POPS CURRENTLY IN THE FORECAST FOR SATURDAY AND FAVOR A SOLUTION IN BETWEEN THE FASTER ECMWF AND SLOWER GFS. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... AS OF 705 AM SUNDAY... BRISK AND GUSTY SURFACE WINDS FROM THE ENE (FROM 060-080 DEGREES) WILL PERSIST THROUGH TODAY/TONIGHT... AND THIS FLOW OF MOIST ATLANTIC AIR INTO NC WILL MAKE SUB-VFR CONDITIONS DOMINANT OVER CENTRAL NC TAF SITES FOR THE NEXT 24 HOURS. IFR TO MVFR CLOUDS (BASED AT 700 TO 1500 FT AGL) HAVE BECOME MOSTLY BROKEN OVER THE LAST SEVERAL HOURS (TOPPED BY BROKEN VFR CLOUDS BASED 4 THOUSAND TO 12 THOUSAND FT AGL). EXPECT MVFR-IFR CIGS TO PERSIST THROUGH THE DAY... ALONG WITH A FEW LIGHT SPRINKLES OR DRIZZLE... BUT VSBYS SHOULD REMAIN MOSTLY VFR TODAY... AND THE HEAVIEST RAINFALL WILL HOLD WEST OF A LINE FROM MT AIRY TO SALISBURY TO CLT TODAY. A PERIOD OF VFR CIGS IS POSSIBLE AFTER 16Z-18Z THIS AFTERNOON... BUT CIGS SHOULD DROP BACK TO MVFR THEN IFR THIS EVENING. WIDESPREAD RAIN WITH SUB-VFR VSBYS WILL MOVE IN SLOWLY FROM THE SW TOWARD THE NE TONIGHT... REACHING INT/GSO/FAY AFTER 01Z AND RDU/RWI AFTER 04Z. SUSTAINED WINDS OF 10-16 KTS GUSTING TO AROUND 20 KTS WILL CONTINUE THROUGH THE FORECAST PERIOD. LOOKING BEYOND 12Z MONDAY MORNING: GOOD CHANCE OF CONTINUED DOMINATION OF SUB-VFR CONDITIONS WITH PERIODS OF RAIN THROUGH AT LEAST TUESDAY AS AN UPPER LEVEL LOW SLOWLY CROSSES THE REGION. BRISK ENE SURFACE WINDS WILL PERSIST THROUGH MONDAY BEFORE WEAKENING MONDAY NIGHT. SHALLOW IFR FOG IS POSSIBLE TUESDAY NIGHT/WEDNESDAY MORNING... AND AGAIN THURSDAY MORNING. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...SMITH LONG TERM...SMITH AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1000 AM CDT SUN MAY 5 2013 .UPDATE... ISSUED AT 1000 AM CDT SUN MAY 5 2013 MORNING RADAR TRENDS SHOW DECREASING PRECIPITATION ACROSS SOUTHEASTERN NORTH DAKOTA. SHORT RANGE MODEL GUIDANCE CONTINUES THIS DECREASING TREND THROUGH THE AFTERNOON. AS A RESULT...UPDATED THE HOURLY POPS TO CHANCE IN THE MORNING DECREASING TO SLIGHT CHANCE OVER LAMOURE AND DICKEY COUNTIES THIS AFTERNOON. THE REMAINING WEATHER ELEMENTS WERE BLENDED TO CURRENT OBS/TRENDS. THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 644 AM CDT SUN MAY 5 2013 NO SIGNIFICANT CHANGES WERE REQUIRED WITH THIS FORECAST UPDATE OTHER THAN TO BLEND TO THE LATEST OBSERVED TRENDS THROUGH 1130 UTC. PATCHY DENSE FOG IS BEGINNING TO FORM JUST OUTSIDE OF THE CWA ACROSS TOWNER AND CAVALIER COUNTIES. LEFT IT OUT OF THE FORECAST FOR ROLETTE AND TOWNER COUNTIES FOR NOW AS THE SUN IS ON THE RISE. THAT SAID...WILL CONTINUE TO MONITOR FOR THE NEXT HOUR OR SO SHOULD THE FOG DEVELOP FURTHER SOUTH AND WEST. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 313 AM CDT SUN MAY 5 2013 THE LATEST WATER VAPOR IMAGERY SHOWS AN H5-H3 CIRCULATION OVER CENTRAL SOUTH DAKOTA. LATEST RADAR SHOWS A NARROW AND PERSISTENT BAND OF LIGHT RAIN BING STEERED NORTHBOUND BY THE AFOREMENTIONED UPPER LOW FROM EASTERN SOUTH DAKOTA...INTO LAMOURE AND DICKEY COUNTIES OF NORTH DAKOTA. THE LATEST RAP AND GFS CONTINUE WITH THE IDEA OF LIGHT RAIN THROUGH MID AFTERNOON...AND HAVE TRENDED POPS APPROPRIATELY...BEGINNING WITH CATEGORICAL AND TRENDING LOWER THIS AFTERNOON. WITH WESTERN AND CENTRAL NORTH DAKOTA ESSENTIALLY IN A COL AREA...THE UPPER LOW REMAINS NEARLY STATIONARY AND MEANDERS LITTLE THROUGH THE SHORT TERM PERIOD. H85 TEMPERATURES RISE A FEW DEGREES IN THE NEXT TWO DAYS...CONSEQUENTLY WILL SEE WARMING TEMPERATURES REFLECTED AT THE SURFACE. HIGHS TODAY WILL REACH INTO 60S WITH LIGHT WINDS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 313 AM CDT SUN MAY 5 2013 HIGHLIGHTS OF THE EXTENDED FORECAST IS A WARM UP TO SLIGHTLY ABOVE NORMAL TEMPERATURES IN THE 70S ON MONDAY INTO TUESDAY..WITH SCATTERED RAIN SHOWERS AND THUNDERSTORMS POSSIBLE WEDNESDAY INTO FRIDAY...WITH TEMPERATURES COOLING LATE IN THE WEEK. A SPLIT FLOW UPPER LEVEL PATTERN IS EXPECTED TO BE IN PLACE ACROSS THE CONUS THROUGH AT LEAST TUESDAY WITH A CUTOFF LOW ACROSS THE SOUTHEASTERN CONUS...AND A SECOND ACROSS THE DESERT SOUTHWEST. THIS PATTERN SUPPORTS DRY CONDITIONS FOR THE NORTHERN PLAINS WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES. THE NEXT CHANCE FOR PRECIPITATION...POSSIBLY THUNDERSTORMS...IS WEDNESDAY INTO FRIDAY AS POTENTIAL NORTHERN STREAM ENERGY SINKS SOUTH ACROSS THE NORTHERN PLAINS. THIS SLIGHT SHIFT OF THE POLAR JET FURTHER SOUTH WITH NORTHWEST FLOW ALOFT SUPPORTS A POSSIBLE COOL DOWN BACK INTO THE 60S THURSDAY AND FRIDAY...AND THE 50S BY SATURDAY. OVERALL...UTILIZED A BLEND OF THE 00 UTC GUIDANCE SUITE FOR MOST FIELDS...FAVORING THE WARMER EDGE OF TEMPERATURE GUIDANCE WHICH HAS SHOWN GREATER VERIFICATION SCORES. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY) ISSUED AT 644 AM CDT SUN MAY 5 2013 VFR/MOSTLY CLEAR SKIES WILL DOMINATE THE AERODROMES NEXT 24HR. THE EXCEPTION WILL BE AT KJMS...WHERE BKN CIGS AT AROUND 10KFT CAN BE EXPECTED. WINDS WILL BE LIGHT...LESS THAN 10KT THROUGH THE PERIOD. && .HYDROLOGY... ISSUED AT 313 AM CDT SUN MAY 5 2013 THE SOURIS RIVER CONTINUES TO BE A COMPLEX MIXTURE OF LOCATIONS RISING WHILE OTHER FORECAST POINTS ARE IN RECESSION. LOWER RELEASES FROM BOUNDARY DAM AND REDUCED SNOWMELT RUNOFF BELOW ALAMEDA AND RAFFERTY DAMS HAS RESULTED IN THE ENTIRE UPPER SOURIS RIVER BASIN FROM SHERWOOD TO MINOT TO VELVA FALLING AND REMAINING BELOW FLOOD STAGE. FARTHER DOWNSTREAM AT TOWNER...BANTRY AND WESTHOPE...THE SOURIS RIVER REMAINS STEADY TO RISING AS FLOOD WATERS SLOWLY MAKE THEIR WAY THROUGH THE AREA. WILLOW CREEK NEAR WILLOW CITY IS EXPECTED TO EXPERIENCE ANOTHER RISE TO JUST ABOVE MINOR FLOOD STAGE THROUGH MONDAY. MUCH OF THE MELT WATER GENERATED IN THIS AREA APPEARS TO BE GOING INTO THE SOIL AND TEMPERING EARLIER EXPECTATIONS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TM SHORT TERM...KS LONG TERM...AYD AVIATION...KS HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
644 AM CDT SUN MAY 5 2013 .UPDATE... ISSUED AT 644 AM CDT SUN MAY 5 2013 NO SIGNIFICANT CHANGES WERE REQUIRED WITH THIS FORECAST UPDATE OTHER THAN TO BLEND TO THE LATEST OBSERVED TRENDS THROUGH 1130 UTC. PATCHY DENSE FOG IS BEGINNING TO FORM JUST OUTSIDE OF THE CWA ACROSS TOWNER AND CAVALIER COUNTIES. LEFT IT OUT OF THE FORECAST FOR ROLETTE AND TOWNER COUNTIES FOR NOW AS THE SUN IS ON THE RISE. THAT SAID...WILL CONTINUE TO MONITOR FOR THE NEXT HOUR OR SO SHOULD THE FOG DEVELOP FURTHER SOUTH AND WEST. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 313 AM CDT SUN MAY 5 2013 THE LATEST WATER VAPOR IMAGERY SHOWS AN H5-H3 CIRCULATION OVER CENTRAL SOUTH DAKOTA. LATEST RADAR SHOWS A NARROW AND PERSISTENT BAND OF LIGHT RAIN BING STEERED NORTHBOUND BY THE AFOREMENTIONED UPPER LOW FROM EASTERN SOUTH DAKOTA...INTO LAMOURE AND DICKEY COUNTIES OF NORTH DAKOTA. THE LATEST RAP AND GFS CONTINUE WITH THE IDEA OF LIGHT RAIN THROUGH MID AFTERNOON...AND HAVE TRENDED POPS APPROPRIATELY...BEGINNING WITH CATEGORICAL AND TRENDING LOWER THIS AFTERNOON. WITH WESTERN AND CENTRAL NORTH DAKOTA ESSENTIALLY IN A COL AREA...THE UPPER LOW REMAINS NEARLY STATIONARY AND MEANDERS LITTLE THROUGH THE SHORT TERM PERIOD. H85 TEMPERATURES RISE A FEW DEGREES IN THE NEXT TWO DAYS...CONSEQUENTLY WILL SEE WARMING TEMPERATURES REFLECTED AT THE SURFACE. HIGHS TODAY WILL REACH INTO 60S WITH LIGHT WINDS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 313 AM CDT SUN MAY 5 2013 HIGHLIGHTS OF THE EXTENDED FORECAST IS A WARM UP TO SLIGHTLY ABOVE NORMAL TEMPERATURES IN THE 70S ON MONDAY INTO TUESDAY..WITH SCATTERED RAIN SHOWERS AND THUNDERSTORMS POSSIBLE WEDNESDAY INTO FRIDAY...WITH TEMPERATURES COOLING LATE IN THE WEEK. A SPLIT FLOW UPPER LEVEL PATTERN IS EXPECTED TO BE IN PLACE ACROSS THE CONUS THROUGH AT LEAST TUESDAY WITH A CUTOFF LOW ACROSS THE SOUTHEASTERN CONUS...AND A SECOND ACROSS THE DESERT SOUTHWEST. THIS PATTERN SUPPORTS DRY CONDITIONS FOR THE NORTHERN PLAINS WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES. THE NEXT CHANCE FOR PRECIPITATION...POSSIBLY THUNDERSTORMS...IS WEDNESDAY INTO FRIDAY AS POTENTIAL NORTHERN STREAM ENERGY SINKS SOUTH ACROSS THE NORTHERN PLAINS. THIS SLIGHT SHIFT OF THE POLAR JET FURTHER SOUTH WITH NORTHWEST FLOW ALOFT SUPPORTS A POSSIBLE COOL DOWN BACK INTO THE 60S THURSDAY AND FRIDAY...AND THE 50S BY SATURDAY. OVERALL...UTILIZED A BLEND OF THE 00 UTC GUIDANCE SUITE FOR MOST FIELDS...FAVORING THE WARMER EDGE OF TEMPERATURE GUIDANCE WHICH HAS SHOWN GREATER VERIFICATION SCORES. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY) ISSUED AT 644 AM CDT SUN MAY 5 2013 VFR/MOSTLY CLEAR SKIES WILL DOMINATE THE AERODROMES NEXT 24HR. THE EXCEPTION WILL BE AT KJMS...WHERE BKN CIGS AT AROUND 10KFT CAN BE EXPECTED. WINDS WILL BE LIGHT...LESS THAN 10KT THROUGH THE PERIOD. && .HYDROLOGY... ISSUED AT 313 AM CDT SUN MAY 5 2013 THE SOURIS RIVER CONTINUES TO BE A COMPLEX MIXTURE OF LOCATIONS RISING WHILE OTHER FORECAST POINTS ARE IN RECESSION. LOWER RELEASES FROM BOUNDARY DAM AND REDUCED SNOWMELT RUNOFF BELOW ALAMEDA AND RAFFERTY DAMS HAS RESULTED IN THE ENTIRE UPPER SOURIS RIVER BASIN FROM SHERWOOD TO MINOT TO VELVA FALLING AND REMAINING BELOW FLOOD STAGE. FARTHER DOWNSTREAM AT TOWNER...BANTRY AND WESTHOPE...THE SOURIS RIVER REMAINS STEADY TO RISING AS FLOOD WATERS SLOWLY MAKE THEIR WAY THROUGH THE AREA. WILLOW CREEK NEAR WILLOW CITY IS EXPECTED TO EXPERIENCE ANOTHER RISE TO JUST ABOVE MINOR FLOOD STAGE THROUGH MONDAY. MUCH OF THE MELT WATER GENERATED IN THIS AREA APPEARS TO BE GOING INTO THE SOIL AND TEMPERING EARLIER EXPECTATIONS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...KS LONG TERM...AYD AVIATION...KS HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
937 AM CDT SUN MAY 5 2013 .UPDATE... UPPER LOW MOVING SLOWLY ACROSS NORTHERN MS THIS MORNING. SFC TROUGH STILL EXPECTED TO RETROGRADE SLIGHTLY THROUGH 18Z AND THEN START TO MOVE SLOWLY EASTWARD. THESE 2 DISTINCT FEATURES ARE SHOWING UP NICELY ON RADAR THIS MORNING AS SHOWERS CONTINUE. LATEST 24 HR RADAR ESTIMATES SHOW THE HIGHEST QPF TOTALS ACROSS OUR SOUTHERN PLATEAU. NOW THOUGH THE RAIN AREA IN THE EAST HAS SHIFTED A LITTLE FURTHER EAST...SOME BACK BUILDING AND OR REDEVELOPMENT IS LIKELY FOR THE AFTERNOON. HRRR IS SHOWING THE REDEVELOPMENT AND THIS MAY BE INDUCED BY SOME PARTIAL CLEARING WHICH WILL LEAD TO WARMER SFC TEMPS AND SOME ADDED DESTABILIZATION. FOR THE FORECAST...NO CHANGES AT THIS TIME. WILL ALLOW THE FLOOD WATCH TO CONTINUE AS IS. && .PREV DISCUSSION... /ISSUED 625 AM CDT SUN MAY 5 2013/ AVIATION UPDATE...FOR 12Z TAF PACKAGE... CURRENT RADAR TRENDS INDICATE THE RAIN SHIELD HAS CLEARED KBNA AND KCKV. KCSV CONTINUES TO BE IMPACTED BY RA AND WILL LIKELY CONTINUE THIS TREND THROUGHOUT THE NEXT 6 TO 12 HOURS. SHOULD STAY MOSTLY MVFR FOR KCSV BUT BRIEF LIFR CONDITIONS COULD DEVELOP DURING HEAVIEST RAINS. KBNA INDICATED SOME LIGHT BR AT TAF ISSUANCE BUT EXPECT THAT TO DISSIPATE QUICKLY AS TEMPERATURES WARM THIS MORNING. MODELS INDICATE REDEVELOPMENT OF SHOWERS BY AROUND 18Z DUE TO WARMING AND CENTRAL LOW PRESSURE BEING OVER TOP MIDDLE TENNESSEE. MIGHT BE AN ISOLATED TSRA DURING THIS PERIOD BUT CONFIDENCE NOT HIGH SO LEFT SHRA IN TAFS FOR NOW. PREV DISCUSSION... /ISSUED 356 AM CDT SUN MAY 5 2013/ SHORT TERM...RAIN CONTINUES TO FALL OVER MOST OF THE NORTHEASTERN HALF OF THE MID STATE THIS MORNING, WITH ANOTHER AREA SHOWERS, WRAPPED AROUND UPPER LOW, APPROACHING OUR SOUTHWESTERN COUNTIES. SEVERAL INCHES OF RAIN HAVE FALLEN OVER MUCH, IF NOT MOST, OF THE FLOOD WATCH AREA AND GROUNDS ARE FULLY SATURATED. ANY HEAVY DOWNPOURS THAT DEVELOP OVER THAT AREA TODAY WILL LEAD TO THE LIKELIHOOD OF PONDING OF WATER AND THE POSSIBILITY OF FLASH FLOODING. A FLOOD ADVISORY IS IN EFFECT FOR PARTS OF EASTERN MIDDLE TENNESSEE, BETWEEN MONTEREY, CROSSVILLE AND ALTAMONT UNTIL 515 AM CDT. NOT MUCH CHANGE IN THE EXPECTED WEATHER PATTERN OVER THE NEXT SEVERAL DAYS, AS CLOSED UPPER LOW WANDERS ACROSS NORTHERN PARTS OF MISSISSIPPI AND ALABAMA. WITH FREEZING LEVEL AND WET-BULB ZERO VALUES SO LOW, WOULDN`T BE SURPRISED IF A FEW THUNDERSTORMS DEVELOP OVER THE SOUTH TODAY AND ARE ACCOMPANIED BY SOME SMALL HAIL. FURTHER NORTH, EXPECT A CONTINUATION OF JUST PLAIN RAIN. LIKELIHOOD FOR SHOWERS AND THUNDERSTORMS CONTINUES ON MONDAY, ESPECIALLY IN DEEPEST MOISTURE OVER THE NORTHEAST AND EXTREME SOUTHERN COUNTIES. EVEN THOUGH UPPER LOW PULLS TO THE ATLANTIC COAST BY TUESDAY, ENOUGH ATMOSPHERIC MOISTURE REMAINS OVER THE MID STATE TO KEEP AT LEAST A CHANCE FOR SHOWERS AND THUNDERSTORMS IN OUR NECK OF THE WOODS. CLEARING SKIES, WET GROUND, AND DEW POINTS IN THE 50S WILL CREATE GOOD CONDITIONS FOR THE FORMATION OF AREAS OF FOG LATE TUESDAY NIGHT AND WEDNESDAY NIGHT. PRECIPITATION BY WEDNESDAY AND THURSDAY SHOULD BECOME RESTRICTED TO THE AFTERNOON HOURS, AND IN THE FORM OF ISOLATED POP-UP SHOWERS AND THUNDERSTORMS. LONG TERM...BELIEVE IT OR NOT, THE EXTENDED FORECAST CONTINUES TO PAINT AN INCREASED CHANCE OF RAIN BY NEXT SATURDAY, WHICH WOULD MAKE IT THE THIRD STRAIGHT SATURDAY WITH RAIN (UGH!). EXTENDED MODELS ARE ALSO YIELDING A RATHER CHILLY PATTERN FOR NEXT WEEKEND, WITH UPPER RIDGE BUILDING OVER THE ROCKIES AND A TROUGH DEEPENING OVER THE OHIO RIVER AND TENNESSEE VALLEYS. && .OHX WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR TNZ009>011-029>034- 063>066-077>080. && $$ 21
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
149 PM EDT SUN MAY 5 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 402 AM EDT SUN MAY 5 2013 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG STRETCHING FM SE CANADA INTO THE UPR GRT LKS TO THE N OF CLOSED LO OVER THE SRN MS RIVER VALLEY THAT WAS RESPONSIBLE FOR THE WINTER WX THE PAST COUPLE OF DAYS. THE 00Z GRB RAOB AND ESPECIALLY THE APX RAOB SHOW A VERY DRY AIRMASS UNDER THIS RDG...WITH THE 00Z H85 DEWPT DEPRESSION AS HI AS 24C/PWAT JUST 0.24 INCH OR 49 PCT OF NORMAL AT APX. BUT THERE IS STILL A RIBBON OF DEEPER MSTR SOME -SHRA EXTENDING NNWWD FM THE CLOSED LO TO THE S INTO MN/ADJOINING ONTARIO. THE 00Z INL RAOB SHOWS A NEARLY SATURATED PROFILE AND 00Z PWAT OF 0.83 INCH...188 PCT OF NORMAL. ALTHOUGH THERE ARE SOME HI CLDS OVER THE E...THAT AREA IS DOMINATED BY THE DRY AIRMASS SHOWN ON THE APX RAOB. WITH H85 TEMPS UP TO 10C...MAX TEMPS YDAY REACHED THE 70S OVER THE SCENTRAL AND ERN CWA WHERE THE DRY AIR ALLOWED FOR QUITE A BIT OF SUNSHINE AND LAKE COOLING WAS ABSENT IN THE NLY FLOW S OF HI PRES CENTERED OVER NW ONTARIO. ALTHOUGH THE DRY AIR ALF HAS PUSHED INTO THE WRN CWA PER THE LATEST RUC ANALYSIS SDNGS...ENUF LLVL MSTR LINGERS THERE UNDER SHARP INVRN AT H9 TO SUPPORT LO CLDS/FOG OVER THE WRN CWA FM THE KEWEENAW THRU GOGEBIC COUNTY. SINCE THE 00Z YPL RAOB SHOWS SOME MSTR BTWN H9-825 EVEN CLOSE TO THE ONTARIO HI CENTER...THERE IS QUITE A BIT OF LO CLD EXTENDING WELL N OF LK SUP TO THE HI PRES RDG AXIS. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LO CLD TRENDS/IMPACT ON TEMPS. POTENTIAL FOR LOW RH OVER THE E/IMPACT ON FIRE WX CONCERNS THIS AFTN IS THE FOCUS THERE. TODAY...UPR RDG AXIS/MID LVL DRY AIR WL REMAIN DOMINANT. ALTHOUGH SFC HI PRES OVER NW ONTARIO IS PROGGED TO DRIFT SLOWLY S TOWARD LK SUP...THE NNW FLOW IN ADVANCE OF THIS HI...ALBEIT LGT...WL LIKELY ACT TO HOLD LO CLDS IN PLACE OVER MUCH OF THE NW HALF OF THE CWA DESPITE THE ONSET OF DIURNAL HEATING THAT WOULD NORMALLY MIX OUT THIS LLVL MSTR. IN FACT...COOL ADVECTION OFF THE CHILLY WATERS OF LK SUP WL TEND TO OFFSET THE DIURNAL HEATING AND MAINTAIN A LLVL INVRN/POTENTIAL FOR MORE PERSISTENT LO CLDS IN THIS AREA AS HI TEMPS HOLD IN THE 40S NEAR THE SHORE. OVER THE E HALF OF THE CWA...A LGT S FLOW WL PREVAIL ARND SFC HI PRES OVER SE ONTARIO. ALTHOUGH THERE MAY BE MODERATION NEAR THE BAY OF GREEN BAY/ LK MI WITH A LK BREEZE...H85 TEMPS NEAR 10C/MIXING TO H8-85 ON NAM/ GFS FCST SDNGS WITH A GOOD DEAL OF SUNSHINE SUPPORT HI TEMPS TOPPING OUT IN THE 70S AWAY FM THE LK COOLING. WITH SFC DEWPTS MIXING OUT TOWARD 35 OVER THE INTERIOR...MIN RH WL LIKELY FALL AS LO AS ABOUT 25 PCT. FORTUNATELY...THE WINDS WL BE LGT...SO NO FIRE WX HEADLINES ARE NECESSARY. TONIGHT...WITH HI PRES FCST TO SHIFT OVHD AND LGT WINDS...EXPECT TEMPS TO DIP INTO THE 30S...FALLING MOST SHARPLY OVER THE E AND SCENTRAL...WHERE MUCH DRIER AIR /PWAT NEAR 0.5 INCH/ WL LINGER. SINCE MORE LLVL MSTR WL BE LINGERNING OVER THE W/NCENTRAL... RETAINED A MENTION OF FOG IN THIS AREA OVERNGT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 402 AM EDT SUN MAY 5 2013 WITH THE CUTOFF LOW SITUATED OVER THE SOUTHEAST CONUS AND THE NORTHERN JET STREAM WELL TO THE NORTH OF THE AREA IN CANADA...A QUIET START TO THE WORK WEEK IS EXPECTED WITH ABOVE NORMAL TEMPERATURES OVER MUCH OF THE AREA. MONDAY AND TUESDAY WILL BE DOMINATED BY HIGH PRESSURE AT THE SURFACE. EXPECT MOSTLY CLEAR SKIES FOR MUCH OF THIS PERIOD...BUT THERE COULD BE SOME HIGH BASED DIURNAL CU DEVELOPING OVER THE INTERIOR WEST DUE TO A POCKET OF 800-750MB MOISTURE. A FEW MODELS HINT AT SOME SHOWER DEVELOPMENT...BUT WITH THE HIGH BASES AND LIMITED MOISTURE KEEPING MLCAPE VALUES BELOW 150 J/KG...THINK IT WILL JUST BE CU. THE SUNSHINE WILL ALLOW FOR AMPLE MIXING...TO 800-775MB...AND LEAD TO HIGHS IN THE LOWER 70S AWAY FROM THE GREAT LAKES. LAKE BREEZES ON BOTH DAYS WILL KEEP TEMPERATURES COOLER NEAR THE GREAT LAKES. DID TRY TO MIX OUT DEWPOINTS A LITTLE MORE THAN THE MODELS HAVE INDICATED BASED OFF WHAT OCCURRED YESTERDAY. FORTUNATELY...WITH LIGHT WINDS UNDER THE HIGH...IT WILL LIMIT FIRE WX CONCERNS OVER THE SOUTH CENTRAL AND EAST EVEN THOUGH FFMC VALUES ARE ON THE INCREASE AND ARE OR BECOMING HIGH. PATCHY GROUND FOG IS POSSIBLE OVER THE KEWEENAW AND INTERIOR WEST MONDAY NIGHT WITH THE CLEAR SKIES AND LOW LEVEL COOLING BY LINGERING SNOW COVER. FARTHER EAST...DRIER AIR IN PLACE WILL LIMIT THE FOG POTENTIAL. OVER THE GREAT LAKES...MODELS ARE HINTING AT FOG DEVELOPMENT WITH THE LIGHT WINDS ON MONDAY. BUT DEWPOINTS AREN/T EXTREMELY HIGH AND WITH DRY AIR ALOFT IT WON/T GET MUCH HELP FROM THE LAND. WITH THAT BEING SAID...IF IT DOES DEVELOP...THE LIGHT WINDS WOULD LEAD TO SLOW MOVEMENT AND IT LINGERING INTO WEDNESDAY. COULD SEE SOME PATCHY GROUND FOG OVER THE FAR WEST LATE TUESDAY NIGHT...BUT CONFIDENCE IS TOO LOW TO ADD AT THIS POINT. THE HIGH PRESSURE WILL BEGIN TO GIVE WAY ON WEDNESDAY...AS AN UPPER TROUGH OVER THE WEST COAST SLIDES INTO THE PLAINS AND A SHORTWAVE SLIDES THROUGH THE NORTHERN STREAM AND PRODUCES A SURFACE LOW THAT MOVES INTO NORTHWEST QUEBEC ON WEDNESDAY. A COLD FRONT ASSOCIATED WITH THIS LOW WILL TRY TO DROP THROUGH THE AREA ON WEDNESDAY AFTERNOON AND NIGHT. WITH THE UPPER TROUGH MOVING INTO THE PLAINS...IT MAY PROVIDE ENOUGH MOISTURE TO PRODUCE SOME SHOWERS. BUT THE MODELS DIFFER ON THE NORTHEASTWARD EXTENT OF THE MOISTURE FROM THE UPPER TROUGH. THE 12Z ECMWF/GEM KEEP THE MOISTURE FARTHER TO THE WEST...WHILE THE 18Z GFS PULLS IT INTO THE UPPER GREAT LAKES. LATEST 00Z GFS/GEM RUNS HAVE TRENDED TOWARDS THE ECMWF IDEA. BASED ON THE EXISTING DRY AIR MASS AND LIMITED MOISTURE RETURN...WOULD TEND TO SIDE WITH THE DRIER IDEA AND WILL ONLY HAVE SLIGHTS OR LOW CHANCE POPS FOR THE PASSAGE OF THE FRONT. BEHIND THE FRONT...ANOTHER NORTHERN STREAM SHORTWAVE MAY AFFECT THE AREA ON FRIDAY NIGHT INTO SATURDAY AND BRING ANOTHER POTENTIAL FOR RAIN. BUT AGAIN...MOISTURE LOOKS TO BE THE CONCERN FOR THAT PERIOD UNLESS THE LOW MOVING THROUGH THE LOWER GREAT LAKES MOVES FARTHER TO THE NORTH. TEMPERATURES WED INTO SATURDAY LOOK TO BE COOLER THAN THE FIRST PART OF THE WORK WEEK...BUT STILL NORMAL OR VERY SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 149 PM EDT SUN MAY 5 2013 VFR CEILINGS AND VIS ARE QUICKLY TAKING HOLD THIS AFTERNOON AS DRY AIR PUSHES IN FROM THE EAST...ERODING THE LOW CLOUDS THAT HAVE BEEN STUCK OVER THE WEST END OF UPPER MICHIGAN THROUGH MUCH OF THE DAY /IWD AND CMX/. YET ANOTHER ROUND OF FOG IS ANTICIPATED TONIGHT...BUT GIVEN SUCH DRY AIR...THE FOG IS NOT EXPECTED TO BE QUITE AS DENSE OR LAST NEARLY AS LONG INTO THE DAY MONDAY. VFR CEILINGS AND VIS SHOULD BE THE RULE AGAIN AT ALL SITES BY APPROX 15Z MONDAY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 402 AM EDT SUN MAY 5 2013 A QUIET PERIOD OF WEATHER IS EXPECTED THROUGH THE PERIOD...WITH THE WINDS LIKELY STAYING BELOW 25KTS. HIGH PRESSURE THAT HAS SETUP OVER THE AREA WILL REMAIN THROUGH THE FIRST PART OF THE WORK WEEK AND LEAD TO LIGHT WINDS. THEN...A COLD FRONT DROPPING SOUTHEAST ACROSS THE UPPER GREAT LAKES ON WEDNESDAY INTO WEDNESDAY NIGHT WILL BRING A WIND SHIFT BUT ONLY 10-20KT WINDS. WEAK HIGH PRESSURE WILL MOVE OVER NORTHERN LAKE SUPERIOR FOR THURSDAY INTO THURSDAY NIGHT AND DIMINISH THE WINDS. && .HYDROLOGY... ISSUED AT 402 AM EDT SUN MAY 5 2013 HYDROLOGY CONCERNS WILL REMAIN OVER THE COMING DAYS...UNTIL THE REMAINING SNOW PACK MELTS OVER THE NORTHWESTERN THIRD OF UPPER MICHIGAN. VISIBLE SATELLITE AND MODIS IMAGERY TODAY STILL SHOWS SNOW REMAINING IN THE HIGHER TERRAIN LOCATIONS OF THE HURON MOUNTAINS AND THE KEWEENAW PENINSULA. FARTHER WEST...THE 10 PLUS INCHES OF WET SNOW WILL ALSO HELP KEEP THE POTENTIAL OF RISING RIVER LEVELS IN PLACE. DID SEE RISES AT SOME OF THE SITES OVER THE WEST /RKLM4 AND ESPECIALLY TRRM4/ WITH THE WARMER TEMPERATURES YESTERDAY AND WOULD EXPECT THAT TO CONTINUE TODAY INTO THE FIRST PART OF THE WORK WEEK. THE STURGEON RIVER AT ALSTON AND CHASSELL...THE MICHIGAMME RIVER AROUND WITCH LAKE...AND THE PAINT RIVER NEAR CRYSTAL FALLS WILL REMAIN CONCERNS INTO AT LEAST EARLY NEXT WEEK...AND IN THE CASE OF THE MICHIGAMME RIVER PERHAPS WELL INTO THE COMING WEEK. BUT OTHERWISE RIVER LEVELS CONTINUE TO COME DOWN DESPITE SOME RECENT HEAVY PRECIP THAT IMPACTED MAINLY THE W HALF OF UPR MI. FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND ADVISORIES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...KF MARINE...SRF HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
346 PM CDT SUN MAY 5 2013 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 345 PM CDT SUN MAY 5 2013 OTHER THAN THE FAIRLY LOW PROBABILITY OF SOME PATCHY FOG OVERNIGHT...THE NEXT 24 HOURS ARE LOOKING DRY AND RATHER UNEVENTFUL...AS TEMPERATURES FINALLY MAKE A LEGITIMATE RUN BACK TOWARD 70 DEGREES ON MONDAY. 19Z OBJECTIVE SURFACE ANALYSIS HIGHLIGHTS A BROAD...ROUGHLY 1022 MILLIBAR NORTH-SOUTH ORIENTED RIDGE AXIS EXTENDING SOUTHWARD ACROSS THE CENTRAL CONUS...IN THE WAKE OF THE DEPARTED SURFACE LOW REFLECTION OF THE SLOW-MOVING CUT OFF UPPER LOW. BREEZES THIS AFTERNOON ACROSS THE CWA ARE GENERALLY OUT OF THE NORTH AT SUSTAINED SPEEDS 10-15 MPH WITH SOME HIGHER GUSTS. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA HIGHLIGHT A SPLIT-FLOW UPPER AIR PATTERN THAT WILL DEFINE MUCH OF THE WEEK...WITH THE CENTRAL PLAINS LOCATED NORTH OF THE SOUTHERN STREAM AND SOUTH OF THE NORTHERN STREAM. DIRECTLY OVERHEAD IN THE MID LEVELS...FAIRLY WEAK WEST-NORTHWEST FLOW PREVAILS...AS THE CENTRAL PLAINS LIES IN BETWEEN TWO DOMINANT CLOSED 500 MILLIBAR LOWS..ONE DEPARTING ACROSS THE SOUTHEAST STATES...AND ANOTHER CENTERED JUST OFF THE CA COAST. IN BETWEEN...A MID/UPPER RIDGE EXTENDS NORTH TOWARD THE CENTRAL PLAINS FROM MEXICO...BUT WITH ANOTHER SMALL-SCALE CUT CLOSED MID LEVEL LOW SPINNING JUST TO THE NORTH OVER SD. AS OUTLINED IN THE EARLIER DISCUSSION...SKY COVER AND RESULTANT TEMPS WERE AT THE MERCY OF LOW STRATUS SCATTERING OUT AND/OR CLEARING FROM WEST-EAST...AND ALL THINGS CONSIDERED...THINGS HAVE ACTUALLY WORKED OUT FAIRLY WELL WITH ROUGHLY THE WESTERN 2/3 OF THE CWA NOW PREDOMINANTLY SUNNY-PARTLY CLOUDY AT THIS HOUR...WHILE MOSTLY CLOUDY SKIES ARE HANGING ON LONGER MAINLY EAST OF HIGHWAY 14. HIGH TEMPS APPEAR ON TRACK TO RANGE FROM THE UPPER 50S NORTHEAST TO MID 60S SOUTHWEST. FORTUNATELY FOR FIRE WEATHER CONCERNS...WINDS ARE GUSTING WELL UNDER 25 MPH...AS DEWPOINTS HAVE CRASHED ENOUGH TO DROP RELATIVE HUMIDITY VALUES TO NEAR/SLIGHTLY BELOW 20 PERCENT IN THE EXTREME WESTERN CWA...MAINLY WESTERN DAWSON/GOSPER/FURNAS COUNTIES. HEADING INTO THIS EVENING/TONIGHT...WILL RUN WITH THE ASSUMPTION THAT THE CURRENTLY ERODING STRATUS DECK WILL CONTINUE TO FADE AWAY EASTWARD WITH TIME INTO THE OAX/TOP AREAS...AND NOT COMPLETELY STALL OUT IN OUR EASTERN COUNTIES OR EVEN PUSH BACK WEST. HOWEVER...AM NOT 100 PERCENT CONFIDENT IN THIS...GIVEN THAT STEERING FLOW AT 900MB DOES TURN MORE EASTERLY TONIGHT...SO WILL HAVE TO KEEP AN EYE ON THESE LOW LEVEL CLOUD TRENDS. OTHERWISE...A GRADUAL INCREASE IN MAINLY THIN MID/HIGH CLOUDS WILL OCCUR TONIGHT...IN RESPONSE TO SUBTLE...LOW AMPLITUDE ENERGY LIFTING NORTHEAST TOWARD THE CENTRAL PLAINS OUT AHEAD OF THE AFOREMENTIONED WESTERN CONUS PARENT TROUGH/CLOSED LOW. GIVEN THAT SKIES SHOULD GENERALLY AVERAGE PARTLY CLOUDY OVERNIGHT...ESPECIALLY WEST...AM NOT ANTICIPATING IDEAL RADIATIONAL COOLING CONDITIONS DESPITE THE CONTINUED PRESENCE OF THE LOW LEVEL RIDGE AXIS SITTING DIRECTLY OVER THE AREA...WHICH WILL RESULT IN SEVERAL HOURS OF GENERALLY LIGHT/VARIABLE TO EASTERLY BREEZES. FOR LOW TEMPS...SLIGHTLY UNDERCUT A BLEND OF 12Z MET/MAV GUIDANCE...WHICH RESULTS IN THE MAJORITY OF THE AREA BOTTOMING OUT BETWEEN 38-43...AND MAYBE DOWN AROUND 36 IN THE COLDER-PRONE WESTERN DAWSON COUNTY AREA. THAT BEING SAID...IF SKIES AVERAGE CLEARER THAN ANTICIPATED...COULD SEE MORE OF THE CWA MAKE A RUN TOWARD THE MID 30S...AND THIS WILL NEED WATCHED IN CASE A FEW SPOTS FLIRT WITH FROST-WORTHY READINGS. FOR NOW...HAVE LEFT OUT FROST MENTION ALL AREAS. HOWEVER...HAVE LEFT IN A MENTION OF PATCHY FOG CWA-WIDE FROM 09Z-13Z AS THE LIGHT WIND REGIME COULD PROMOTE SOME DEVELOPMENT. THIS WOULD GENERALLY SEEM MOST FAVORED WITHIN THE EASTERN 1/2 OF THE CWA IN CLOSEST PROXIMITY TO THE WEST EDGE OF LOWER STRATUS...AND ALSO OVER WHERE A BIT MORE LIGHT PRECIP FELL DURING THE PAST FEW DAYS. FOR NOW...AM NOT EXPECTING SIGNIFICANT VISIBILITY ISSUES...BUT ITS WORTH NOTING THAT THE LATEST HRRR ACTUALLY DOES SUGGEST SOME DENSER FOG DEVELOPMENT MAINLY EAST OF HIGHWAY 281...SO THIS ALSO BEARS WATCHING. TURNING TO THE DAYTIME HOURS MONDAY...THE OVERALL MID/UPPER AIR PATTERN CHANGES LITTLE...AS THE CENTRAL PLAINS REMAIN UNDER FAIRLY UNEVENTFUL QUASI-ZONAL FLOW ALOFT...AND STILL DOWNSTREAM FROM A LEAD SHORTWAVE EJECTING NORTHEAST TOWARD THE REGION FROM THE DESERT SOUTHWEST...WHICH COULD PROMOTE SOME RAIN CHANCES MONDAY NIGHT AS DESCRIBED BELOW. IN ADDITION...JUST TO THE NORTH THE COMPACT LITTLE CLOSED LOW OVER SD SHOULD PRETTY MUCH REMAIN IN PLACE...WITH LITTLE CONSEQUENCE INTO NEB/KS. AT THE SURFACE...THE RIDGE AXIS WILL ONLY SLOWLY EDGE EAST DURING THE DAY...PROVIDING A DAY OF FAIRLY LIGHT BREEZES. EVEN DURING THE AFTERNOON...THE EASTERN 1/2 OF THE CWA WILL ONLY AVERAGE AROUND 5 MPH...WHILE WESTERN COUNTIES PICK UP A SLIGHTLY STRONGER EAST-SOUTHEAST BREEZE OF 10 TO POSSIBLY 15 MPH. ASSUMING THAT SKIES AVERAGE MOSTLY CLEAR/PARTLY CLOUDY UNDER ONLY PASSING MID-HIGH CLOUDS...SHOULD SEE A NICE JUMP IN HIGH TEMPS VERSUS TODAY...AND MADE LITTLE CHANGE TO PREVIOUS FORECAST WITH ALL AREAS RISING TO WITHIN A FEW DEGREES EITHER SIDE OF 70. THE ONLY CAVEAT FOR THESE WARM TEMPS WOULD BE IF ANY MORNING FOG TURNS INTO A SLOW-ERODING STRATUS DECK THAT LINGERS WELL INTO THE DAY WITHIN THE RIDGE AXIS MAINLY IN THE EASTERN CWA...BUT IT SEEMS UNLIKELY THAT THE SITUATION GETS THIS PESSIMISTIC. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 345 PM CDT SUN MAY 5 2013 A PROLONGED PERIOD OF UNSETTLED WEATHER IS SHAPING UP ACROSS THE REGION AS THE UPPER LEVEL LOW OFF THE CALIFORNIA COAST SLOWLY PROGRESSES EASTWARD WHILE SPINNING OFF SEVERAL WEAK DISTURBANCES AHEAD OF IT. WHILE A GENERALLY BLOCKY PATTERN WITH RIDGING WILL EXIST ACROSS THE CENTRAL PLAINS THROUGH MUCH OF THE PERIOD...THE LOW LEVEL FLOW WILL BEGIN TO SHIFT AND BECOME SOUTHERLY LATE MONDAY...HELPING MOISTURE ADVECT NORTHWARD. THIS FLOW SHOULD HELP DEWPOINTS CLIMB BACK INTO THE 50S BY TUESDAY AFTERNOON...WITH BUILDING INSTABILITY ACROSS THE PLAINS. WHILE INITIALLY...THERE WILL BE A SMALL CHANCE FOR SOME RAIN SHOWERS AHEAD OF THE FIRST UPPER LEVEL WAVE SPINNING OFF THE WESTERN LOW...INSTABILITY WILL BE VERY WEAK...AND LOW LEVEL MOISTURE WILL STILL BE LACKING...IN ORDER TO SUPPORT MUCH IN THE WAY OF SHOWER OR THUNDERSTORM ACTIVITY. AS A RESULT...SLOWED DOWN THE INITIAL TIMING OF THE ONSET OF ANY PRECIPITATION TO THE PRE-DAWN HOURS TUESDAY. AS MOISTURE CONTINUES TO SURGE NORTH DURING THE DAY TUESDAY AFTERNOON...INSTABILITY WILL BUILD...AND SEE THE POTENTIAL FOR SOME THUNDERSTORMS TO DEVELOP DURING THE LATE MORNING/EARLY AFTERNOON HOURS AS STEEP LOW LEVEL LAPSE RATES WILL REQUIRE LITTLE IN THE WAY OF FORCING FOR SHOWER AND THUNDERSTORM DEVELOPMENT. AS WE THEN TRANSITION INTO TUESDAY NIGHT...THE NOSE OF THE LOW LEVEL JET IS EXPECTED TO BE POINTED TOWARDS THE LOCAL AREA...WHICH SHOULD ALLOW FOR THE DEVELOPMENT OF ELEVATED CONVECTION ACROSS THE LOCAL AREA DURING THE LATE EVENING AND OVERNIGHT HOURS...SOME OF WHICH COULD BECOME STRONG TO MARGINALLY SEVERE. AS A RESULT...PLAN ON HIGHLIGHTING THE POTENTIAL FOR SOME MARGINALLY SEVERE HAIL FOR THE TUESDAY NIGHT PERIOD IN THE AFTERNOON HWO. BEYOND TUESDAY NIGHT...THINGS GET A LITTLE MORE MUDDLED AS MULTIPLE WEAK DISTURBANCES AHEAD OF THE MAIN UPPER LEVEL LOW TRANSITION ACROSS THE PLAINS. EVEN SO...THERE IS SOME AGREEMENT AMONGST THE MODELS FOR ANOTHER DECENT SHOT OF PRECIPITATION ACROSS NORTH CENTRAL KANSAS AND PORTIONS OF SOUTH CENTRAL NEBRASKA WEDNESDAY NIGHT AND THURSDAY...AND SAW NO REASON TO REDUCE THE LIKELY POPS GIVEN BY THE ALLBLEND SOLUTION FOR THIS PERIOD. THEN...DEPENDING ON WHICH MODEL SOLUTION YOU BELIEVE...THE MAIN UPPER LEVEL LOW SHOULD BEGIN TO TRACK EASTWARD ON FRIDAY...WITH A COLD FRONT DROPPING DOWN ACROSS THE NORTHERN PLAINS FRIDAY NIGHT OR SATURDAY. DUE TO THE DISCREPANCIES IN TIMING...HUNG ONTO CHANCES FOR PRECIPITATION THROUGH SATURDAY AFTERNOON...WITH PRECIPITATION COMING TO AN END BEHIND THIS COLD FRONT BY THE LATTER HALF OF NEXT WEEKEND. WHILE THERE WILL BE A NOTICEABLE DROP IN TEMPERATURES BEHIND THIS FRONT...ON THE ORDER OF 10-15F BASED ON 850MB TEMPS...DO NOT EXPECT A RETURN TO THE CHILLY TEMPERATURES OF LATE...AS ABOVE NORMAL TEMPERATURES ARE EXPECTED ALL WEEK...GENERALLY IN THE LOWER TO MIDDLE 70S...WITH THIS NEXT FRONT SIMPLY DROPPING TEMPERATURES A FEW DEGREES BELOW CLIMATOLOGY FOR EARLY/MID MAY. && .AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 100 PM CDT SUN MAY 5 2013 ALTHOUGH VFR CEILING/VISIBILITY AND PRECIP-FREE CONDITIONS ARE FORECAST THROUGH THE MAJORITY OF THE PERIOD...WILL HAVE TO CONTEND WITH AT LEAST A FEW HOURS OF LINGERING MVFR CEILING THIS AFTERNOON...AS A LOW STRATUS DECK ONLY VERY VERY SLOWLY ERODES AND/OR LIFTS ACROSS CENTRAL NEBRASKA. TOOK A BEST STAB USING LATEST TRENDS/GUIDANCE BY RAISING CEILING ABOVE 2000 FT BY 19Z...AND ABOVE 3000 FT BY 22Z...STAYING IN LINE WITH PREVIOUS MORNING TAF ISSUANCE. WILL DEPICT A SCATTERED LOW CLOUD SITUATION BY 00Z EARLY THIS EVENING...AND ASSUME THAT A BKN/OVC LOW DECK WILL NOT AGAIN RETURN. HOWEVER...GIVEN THAT THE LOW LEVEL STEERING FLOW TAKES ON MORE OF AN EASTERLY COMPONENT OVERNIGHT...ITS NOT COMPLETELY OUT OF THE QUESTION THAT MVFR CEILING COULD MAKE A RETURN...AND THIS WILL NEED CLOSELY WATCHED DESPITE LACK OF SUPPORT IN COMPUTER MODELS/GUIDANCE. AS FOR VISIBILITY...CONFIDENCE IS FAIRLY HIGH IN VFR THROUGH THE PERIOD...ALTHOUGH ITS ALSO NOT OUT OF THE QUESTION THAT SOME HAZE/LIGHT FOG COULD DEVELOP WITHIN A SURFACE RIDGE AXIS LATE TONIGHT. THIS STILL SEEMS UNLIKELY ENOUGH TO OMIT FOR NOW. SURFACE WIND-WISE...FAIRLY LIGHT SPEEDS SUSTAINED AT NO MORE THAN 5-10KT ARE ANTICIPATED THROUGH THE MAJORITY OF THE PERIOD...AS NORTHERLY FLOW THIS AFTERNOON BECOMES LIGHT/VARIABLE OVERNIGHT AND EVENTUALLY EASTERLY MONDAY MORNING. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH LONG TERM...SAR AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1258 PM CDT SUN MAY 5 2013 .UPDATE... ISSUED AT 1258 PM CDT SUN MAY 5 2013 NO MAJOR MODIFICATIONS WERE MADE TO THE ONGOING FORECAST. ONLY UPDATED THE AFTERNOON MAX TEMP FORECAST ACROSS NORTH CENTRAL NORTH DAKOTA BASED ON CURRENT OBS/TRENDS. OTHERWISE...THE REMAINING WEATHER ELEMENTS ARE IN GOOD SHAPE. THE UPDATED GRIDDED/TEXT PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 1000 AM CDT SUN MAY 5 2013 MORNING RADAR TRENDS SHOW DECREASING PRECIPITATION ACROSS SOUTHEASTERN NORTH DAKOTA. SHORT RANGE MODEL GUIDANCE CONTINUES THIS DECREASING TREND THROUGH THE AFTERNOON. AS A RESULT...UPDATED THE HOURLY POPS TO CHANCE IN THE MORNING DECREASING TO SLIGHT CHANCE OVER LAMOURE AND DICKEY COUNTIES THIS AFTERNOON. THE REMAINING WEATHER ELEMENTS WERE BLENDED TO CURRENT OBS/TRENDS. THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 644 AM CDT SUN MAY 5 2013 NO SIGNIFICANT CHANGES WERE REQUIRED WITH THIS FORECAST UPDATE OTHER THAN TO BLEND TO THE LATEST OBSERVED TRENDS THROUGH 1130 UTC. PATCHY DENSE FOG IS BEGINNING TO FORM JUST OUTSIDE OF THE CWA ACROSS TOWNER AND CAVALIER COUNTIES. LEFT IT OUT OF THE FORECAST FOR ROLETTE AND TOWNER COUNTIES FOR NOW AS THE SUN IS ON THE RISE. THAT SAID...WILL CONTINUE TO MONITOR FOR THE NEXT HOUR OR SO SHOULD THE FOG DEVELOP FURTHER SOUTH AND WEST. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 313 AM CDT SUN MAY 5 2013 THE LATEST WATER VAPOR IMAGERY SHOWS AN H5-H3 CIRCULATION OVER CENTRAL SOUTH DAKOTA. LATEST RADAR SHOWS A NARROW AND PERSISTENT BAND OF LIGHT RAIN BING STEERED NORTHBOUND BY THE AFOREMENTIONED UPPER LOW FROM EASTERN SOUTH DAKOTA...INTO LAMOURE AND DICKEY COUNTIES OF NORTH DAKOTA. THE LATEST RAP AND GFS CONTINUE WITH THE IDEA OF LIGHT RAIN THROUGH MID AFTERNOON...AND HAVE TRENDED POPS APPROPRIATELY...BEGINNING WITH CATEGORICAL AND TRENDING LOWER THIS AFTERNOON. WITH WESTERN AND CENTRAL NORTH DAKOTA ESSENTIALLY IN A COL AREA...THE UPPER LOW REMAINS NEARLY STATIONARY AND MEANDERS LITTLE THROUGH THE SHORT TERM PERIOD. H85 TEMPERATURES RISE A FEW DEGREES IN THE NEXT TWO DAYS...CONSEQUENTLY WILL SEE WARMING TEMPERATURES REFLECTED AT THE SURFACE. HIGHS TODAY WILL REACH INTO 60S WITH LIGHT WINDS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 313 AM CDT SUN MAY 5 2013 HIGHLIGHTS OF THE EXTENDED FORECAST IS A WARM UP TO SLIGHTLY ABOVE NORMAL TEMPERATURES IN THE 70S ON MONDAY INTO TUESDAY..WITH SCATTERED RAIN SHOWERS AND THUNDERSTORMS POSSIBLE WEDNESDAY INTO FRIDAY...WITH TEMPERATURES COOLING LATE IN THE WEEK. A SPLIT FLOW UPPER LEVEL PATTERN IS EXPECTED TO BE IN PLACE ACROSS THE CONUS THROUGH AT LEAST TUESDAY WITH A CUTOFF LOW ACROSS THE SOUTHEASTERN CONUS...AND A SECOND ACROSS THE DESERT SOUTHWEST. THIS PATTERN SUPPORTS DRY CONDITIONS FOR THE NORTHERN PLAINS WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES. THE NEXT CHANCE FOR PRECIPITATION...POSSIBLY THUNDERSTORMS...IS WEDNESDAY INTO FRIDAY AS POTENTIAL NORTHERN STREAM ENERGY SINKS SOUTH ACROSS THE NORTHERN PLAINS. THIS SLIGHT SHIFT OF THE POLAR JET FURTHER SOUTH WITH NORTHWEST FLOW ALOFT SUPPORTS A POSSIBLE COOL DOWN BACK INTO THE 60S THURSDAY AND FRIDAY...AND THE 50S BY SATURDAY. OVERALL...UTILIZED A BLEND OF THE 00 UTC GUIDANCE SUITE FOR MOST FIELDS...FAVORING THE WARMER EDGE OF TEMPERATURE GUIDANCE WHICH HAS SHOWN GREATER VERIFICATION SCORES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY) ISSUED AT 1258 PM CDT SUN MAY 5 2013 VFR CONDITIONS WILL PREVAIL OVER WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE TAF PERIOD. WINDS WILL GENERALLY BE LIGHT AND VARIABLE. && .HYDROLOGY... ISSUED AT 313 AM CDT SUN MAY 5 2013 THE SOURIS RIVER CONTINUES TO BE A COMPLEX MIXTURE OF LOCATIONS RISING WHILE OTHER FORECAST POINTS ARE IN RECESSION. LOWER RELEASES FROM BOUNDARY DAM AND REDUCED SNOWMELT RUNOFF BELOW ALAMEDA AND RAFFERTY DAMS HAS RESULTED IN THE ENTIRE UPPER SOURIS RIVER BASIN FROM SHERWOOD TO MINOT TO VELVA FALLING AND REMAINING BELOW FLOOD STAGE. FARTHER DOWNSTREAM AT TOWNER...BANTRY AND WESTHOPE...THE SOURIS RIVER REMAINS STEADY TO RISING AS FLOOD WATERS SLOWLY MAKE THEIR WAY THROUGH THE AREA. WILLOW CREEK NEAR WILLOW CITY IS EXPECTED TO EXPERIENCE ANOTHER RISE TO JUST ABOVE MINOR FLOOD STAGE THROUGH MONDAY. MUCH OF THE MELT WATER GENERATED IN THIS AREA APPEARS TO BE GOING INTO THE SOIL AND TEMPERING EARLIER EXPECTATIONS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TM SHORT TERM...KS LONG TERM...AYD AVIATION...TM HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1245 PM CDT SUN MAY 5 2013 .UPDATE... && .AVIATION... 18Z TAFS..LOW PRESSURE HANGING OVER THE AREA WILL CONTINUE TO PRODUCE SCT SHRA THROUGH THE TAF PERIOD. MODELS SUGGEST THAT THE DRY SLOT OVER BNA AND CKV WILL FILL IN WITH MOISTURE AND AT LEAST SCATTERED SHOWERS AFTER 21Z. BNA/CKV WILL THEN VARY FROM MVFR TO IFR WITH ON AND OFF RAIN OVERNIGHT INTO MONDAY MORNING. CSV WILL VARY FROM IFR TO LIFR THROUGH THE PERIOD WITH SOME IMPROVEMENT POSSIBLE AFTER 14Z MONDAY. 13 && .PREV DISCUSSION... /ISSUED 1145 AM CDT SUN MAY 5 2013/ UPDATE... HAVE OPTED TO CANCEL THE FLOOD WATCH. THOUGH ADDITIONAL REDEVELOPMENT IS EXPECTED ACROSS THE MID STATE...QPF RETURNS ARE EXPECTED TO REMAIN INSIGNIFICANT. FURTHERMORE...LATEST RFC ISSUED FFG IS WELL ABOVE ANY EXPECTED QPF RETURNS OVER THE NEXT 24 TO 48 HOURS. MOISTURE IN ASSOCIATION WITH THE UPPER LEVEL LOW WILL CONTINUE TO MOVE ACROSS SOUTHERN MIDDLE TN TODAY...BUT AGAIN...QPF RETURNS WILL REMAIN RATHER LOW. ONLY OTHER CHANGE AT THIS TIME WILL BE TO LOWER MAX TEMPS A DEGREE OR TWO ACROSS THE BOARD. COULD STILL SEE A BRIEF PEAK OF SUNSHINE THIS AFTERNOON TO THE WEST OF THE PLATEAU. IT SHOULD REMAIN BRIEF HOWEVER. UPDATES INCLUDING THE FLOOD WATCH CANCELLATION WILL BE SENT SHORTLY. PREV DISCUSSION... /ISSUED 937 AM CDT SUN MAY 5 2013/ UPDATE... UPPER LOW MOVING SLOWLY ACROSS NORTHERN MS THIS MORNING. SFC TROUGH STILL EXPECTED TO RETROGRADE SLIGHTLY THROUGH 18Z AND THEN START TO MOVE SLOWLY EASTWARD. THESE 2 DISTINCT FEATURES ARE SHOWING UP NICELY ON RADAR THIS MORNING AS SHOWERS CONTINUE. LATEST 24 HR RADAR ESTIMATES SHOW THE HIGHEST QPF TOTALS ACROSS OUR SOUTHERN PLATEAU. NOW THOUGH THE RAIN AREA IN THE EAST HAS SHIFTED A LITTLE FURTHER EAST...SOME BACK BUILDING AND OR REDEVELOPMENT IS LIKELY FOR THE AFTERNOON. HRRR IS SHOWING THE REDEVELOPMENT AND THIS MAY BE INDUCED BY SOME PARTIAL CLEARING WHICH WILL LEAD TO WARMER SFC TEMPS AND SOME ADDED DESTABILIZATION. FOR THE FORECAST...NO CHANGES AT THIS TIME. WILL ALLOW THE FLOOD WATCH TO CONTINUE AS IS. PREV DISCUSSION... /ISSUED 356 AM CDT SUN MAY 5 2013/ SHORT TERM...RAIN CONTINUES TO FALL OVER MOST OF THE NORTHEASTERN HALF OF THE MID STATE THIS MORNING, WITH ANOTHER AREA SHOWERS, WRAPPED AROUND UPPER LOW, APPROACHING OUR SOUTHWESTERN COUNTIES. SEVERAL INCHES OF RAIN HAVE FALLEN OVER MUCH, IF NOT MOST, OF THE FLOOD WATCH AREA AND GROUNDS ARE FULLY SATURATED. ANY HEAVY DOWNPOURS THAT DEVELOP OVER THAT AREA TODAY WILL LEAD TO THE LIKELIHOOD OF PONDING OF WATER AND THE POSSIBILITY OF FLASH FLOODING. A FLOOD ADVISORY IS IN EFFECT FOR PARTS OF EASTERN MIDDLE TENNESSEE, BETWEEN MONTEREY, CROSSVILLE AND ALTAMONT UNTIL 515 AM CDT. NOT MUCH CHANGE IN THE EXPECTED WEATHER PATTERN OVER THE NEXT SEVERAL DAYS, AS CLOSED UPPER LOW WANDERS ACROSS NORTHERN PARTS OF MISSISSIPPI AND ALABAMA. WITH FREEZING LEVEL AND WET-BULB ZERO VALUES SO LOW, WOULDN`T BE SURPRISED IF A FEW THUNDERSTORMS DEVELOP OVER THE SOUTH TODAY AND ARE ACCOMPANIED BY SOME SMALL HAIL. FURTHER NORTH, EXPECT A CONTINUATION OF JUST PLAIN RAIN. LIKELIHOOD FOR SHOWERS AND THUNDERSTORMS CONTINUES ON MONDAY, ESPECIALLY IN DEEPEST MOISTURE OVER THE NORTHEAST AND EXTREME SOUTHERN COUNTIES. EVEN THOUGH UPPER LOW PULLS TO THE ATLANTIC COAST BY TUESDAY, ENOUGH ATMOSPHERIC MOISTURE REMAINS OVER THE MID STATE TO KEEP AT LEAST A CHANCE FOR SHOWERS AND THUNDERSTORMS IN OUR NECK OF THE WOODS. CLEARING SKIES, WET GROUND, AND DEW POINTS IN THE 50S WILL CREATE GOOD CONDITIONS FOR THE FORMATION OF AREAS OF FOG LATE TUESDAY NIGHT AND WEDNESDAY NIGHT. PRECIPITATION BY WEDNESDAY AND THURSDAY SHOULD BECOME RESTRICTED TO THE AFTERNOON HOURS, AND IN THE FORM OF ISOLATED POP-UP SHOWERS AND THUNDERSTORMS. LONG TERM...BELIEVE IT OR NOT, THE EXTENDED FORECAST CONTINUES TO PAINT AN INCREASED CHANCE OF RAIN BY NEXT SATURDAY, WHICH WOULD MAKE IT THE THIRD STRAIGHT SATURDAY WITH RAIN (UGH!). EXTENDED MODELS ARE ALSO YIELDING A RATHER CHILLY PATTERN FOR NEXT WEEKEND, WITH UPPER RIDGE BUILDING OVER THE ROCKIES AND A TROUGH DEEPENING OVER THE OHIO RIVER AND TENNESSEE VALLEYS. && .OHX WATCHES/WARNINGS/ADVISORIES...NONE. && $$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1145 AM CDT SUN MAY 5 2013 .UPDATE... HAVE OPTED TO CANCEL THE FLOOD WATCH. THOUGH ADDITIONAL REDEVELOPMENT IS EXPECTED ACROSS THE MID STATE...QPF RETURNS ARE EXPECTED TO REMAIN INSIGNIFICANT. FURTHERMORE...LATEST RFC ISSUED FFG IS WELL ABOVE ANY EXPECTED QPF RETURNS OVER THE NEXT 24 TO 48 HOURS. MOISTURE IN ASSOCIATION WITH THE UPPER LEVEL LOW WILL CONTINUE TO MOVE ACROSS SOUTHERN MIDDLE TN TODAY...BUT AGAIN...QPF RETURNS WILL REMAIN RATHER LOW. ONLY OTHER CHANGE AT THIS TIME WILL BE TO LOWER MAX TEMPS A DEGREE OR TWO ACROSS THE BOARD. COULD STILL SEE A BRIEF PEAK OF SUNSHINE THIS AFTERNOON TO THE WEST OF THE PLATEAU. IT SHOULD REMAIN BRIEF HOWEVER. UPDATES INCLUDING THE FLOOD WATCH CANCELLATION WILL BE SENT SHORTLY. && .PREV DISCUSSION... /ISSUED 937 AM CDT SUN MAY 5 2013/ UPDATE... UPPER LOW MOVING SLOWLY ACROSS NORTHERN MS THIS MORNING. SFC TROUGH STILL EXPECTED TO RETROGRADE SLIGHTLY THROUGH 18Z AND THEN START TO MOVE SLOWLY EASTWARD. THESE 2 DISTINCT FEATURES ARE SHOWING UP NICELY ON RADAR THIS MORNING AS SHOWERS CONTINUE. LATEST 24 HR RADAR ESTIMATES SHOW THE HIGHEST QPF TOTALS ACROSS OUR SOUTHERN PLATEAU. NOW THOUGH THE RAIN AREA IN THE EAST HAS SHIFTED A LITTLE FURTHER EAST...SOME BACK BUILDING AND OR REDEVELOPMENT IS LIKELY FOR THE AFTERNOON. HRRR IS SHOWING THE REDEVELOPMENT AND THIS MAY BE INDUCED BY SOME PARTIAL CLEARING WHICH WILL LEAD TO WARMER SFC TEMPS AND SOME ADDED DESTABILIZATION. FOR THE FORECAST...NO CHANGES AT THIS TIME. WILL ALLOW THE FLOOD WATCH TO CONTINUE AS IS. PREV DISCUSSION... /ISSUED 625 AM CDT SUN MAY 5 2013/ AVIATION UPDATE...FOR 12Z TAF PACKAGE... CURRENT RADAR TRENDS INDICATE THE RAIN SHIELD HAS CLEARED KBNA AND KCKV. KCSV CONTINUES TO BE IMPACTED BY RA AND WILL LIKELY CONTINUE THIS TREND THROUGHOUT THE NEXT 6 TO 12 HOURS. SHOULD STAY MOSTLY MVFR FOR KCSV BUT BRIEF LIFR CONDITIONS COULD DEVELOP DURING HEAVIEST RAINS. KBNA INDICATED SOME LIGHT BR AT TAF ISSUANCE BUT EXPECT THAT TO DISSIPATE QUICKLY AS TEMPERATURES WARM THIS MORNING. MODELS INDICATE REDEVELOPMENT OF SHOWERS BY AROUND 18Z DUE TO WARMING AND CENTRAL LOW PRESSURE BEING OVER TOP MIDDLE TENNESSEE. MIGHT BE AN ISOLATED TSRA DURING THIS PERIOD BUT CONFIDENCE NOT HIGH SO LEFT SHRA IN TAFS FOR NOW. PREV DISCUSSION... /ISSUED 356 AM CDT SUN MAY 5 2013/ SHORT TERM...RAIN CONTINUES TO FALL OVER MOST OF THE NORTHEASTERN HALF OF THE MID STATE THIS MORNING, WITH ANOTHER AREA SHOWERS, WRAPPED AROUND UPPER LOW, APPROACHING OUR SOUTHWESTERN COUNTIES. SEVERAL INCHES OF RAIN HAVE FALLEN OVER MUCH, IF NOT MOST, OF THE FLOOD WATCH AREA AND GROUNDS ARE FULLY SATURATED. ANY HEAVY DOWNPOURS THAT DEVELOP OVER THAT AREA TODAY WILL LEAD TO THE LIKELIHOOD OF PONDING OF WATER AND THE POSSIBILITY OF FLASH FLOODING. A FLOOD ADVISORY IS IN EFFECT FOR PARTS OF EASTERN MIDDLE TENNESSEE, BETWEEN MONTEREY, CROSSVILLE AND ALTAMONT UNTIL 515 AM CDT. NOT MUCH CHANGE IN THE EXPECTED WEATHER PATTERN OVER THE NEXT SEVERAL DAYS, AS CLOSED UPPER LOW WANDERS ACROSS NORTHERN PARTS OF MISSISSIPPI AND ALABAMA. WITH FREEZING LEVEL AND WET-BULB ZERO VALUES SO LOW, WOULDN`T BE SURPRISED IF A FEW THUNDERSTORMS DEVELOP OVER THE SOUTH TODAY AND ARE ACCOMPANIED BY SOME SMALL HAIL. FURTHER NORTH, EXPECT A CONTINUATION OF JUST PLAIN RAIN. LIKELIHOOD FOR SHOWERS AND THUNDERSTORMS CONTINUES ON MONDAY, ESPECIALLY IN DEEPEST MOISTURE OVER THE NORTHEAST AND EXTREME SOUTHERN COUNTIES. EVEN THOUGH UPPER LOW PULLS TO THE ATLANTIC COAST BY TUESDAY, ENOUGH ATMOSPHERIC MOISTURE REMAINS OVER THE MID STATE TO KEEP AT LEAST A CHANCE FOR SHOWERS AND THUNDERSTORMS IN OUR NECK OF THE WOODS. CLEARING SKIES, WET GROUND, AND DEW POINTS IN THE 50S WILL CREATE GOOD CONDITIONS FOR THE FORMATION OF AREAS OF FOG LATE TUESDAY NIGHT AND WEDNESDAY NIGHT. PRECIPITATION BY WEDNESDAY AND THURSDAY SHOULD BECOME RESTRICTED TO THE AFTERNOON HOURS, AND IN THE FORM OF ISOLATED POP-UP SHOWERS AND THUNDERSTORMS. LONG TERM...BELIEVE IT OR NOT, THE EXTENDED FORECAST CONTINUES TO PAINT AN INCREASED CHANCE OF RAIN BY NEXT SATURDAY, WHICH WOULD MAKE IT THE THIRD STRAIGHT SATURDAY WITH RAIN (UGH!). EXTENDED MODELS ARE ALSO YIELDING A RATHER CHILLY PATTERN FOR NEXT WEEKEND, WITH UPPER RIDGE BUILDING OVER THE ROCKIES AND A TROUGH DEEPENING OVER THE OHIO RIVER AND TENNESSEE VALLEYS. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
240 PM CDT SUN MAY 5 2013 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 230 PM CDT SUN MAY 5 2013 MAIN FORECAST CONCERN IS ON ANY FOG POTENTIAL TONIGHT CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED UPPER HIGHS IN SOUTHERN BRITISH COLUMBIA AND OVER THE GREAT LAKES REGIONS...WHILE UPPER LOWS WERE PRESENT JUST WEST OF SAN FRANSISCO CA...OVER CENTRAL SOUTH DAKOTA AND OVER ALABAMA. THIS SETUP RESULTS IN LITTLE FLOW IN THE UPPER LEVELS ACROSS THE NORTHERN U.S.. THERE REMAINS SCATTERED-BROKEN HIGH CLOUDS OVER THE AREA...ON THE SOUTHWEST SIDE OF THE UPPER HIGH. OTHERWISE...A DRY AIRMASS HAS BEEN ADVECTING INTO THE FORECAST AREA FROM THE EAST...WITH THE 12Z GRB SOUNDING REFLECTIVE OF THE DRY AIR. THE COMBINATION OF THE DRY AIR...850MB TEMPS AROUND 8C...AND THE SUN HAS ALLOWED TEMPERATURES TO CLIMB INTO THE 65 TO 75 DEGREE RANGE WHERE SNOW DOES NOT EXIST. MEANWHILE...DODGE CENTER WHICH STILL HAS A DECENT AMOUNT OF SNOW ON THE GROUND...TEMPERATURES ARE STUCK IN THE MID 40S. REGARDING THE SEA LEVEL PRESSURE PATTERN...HIGH PRESSURE STRETCHED ACROSS NORTHERN MINNESOTA INTO NORTHERN ONTARIO...WHILE AN INVERTED TROUGH WAS PRESENT OVER WESTERN WISCONSIN...EXTENDING NORTH FROM LOW PRESSURE IN ALABAMA. LITTLE CHANGE IS PROGGED TO THE UPPER LEVEL PATTERN ACROSS THE UPPER MIDWEST INTO THE GREAT LAKES WITH PERHAPS JUST A SLIGHT BREAKDOWN OF THE UPPER RIDGE OVER THE GREAT LAKES. AS A RESULT...NOT EXPECTING MUCH CHANGE BETWEEN WHAT HAPPENED TODAY TO WHAT WILL HAPPEN TOMORROW. IF ANYTHING...WINDS SHOULD BE A BIT LIGHTER WITH THE HIGH PRESSURE AREA OVER NORTHERN ONTARIO PROGGED TO DRIFT SOUTH INTO NORTHERN WISCONSIN BY 00Z TUESDAY. PER 200-300MB RH PROGS...LOOKS LIKE THE SCATTERED TO BROKEN HIGH CLOUDS WILL PERSIST ACROSS THE AREA THROUGH MONDAY. THESE CLOUDS COMBINED WITH LIGHT NORTHERLY DRY ADVECTION SHOULD PRECLUDE ANY FOG DEVELOPMENT TONIGHT...DESPITE PERSISTENCE FROM SREF PROGS AND NMM CORE MODELS WHICH CONTINUE TO SHOW TOO HIGH OF DEWPOINTS. EVEN WORSE...THE 05.12Z NAM AND NCEP HIRES NMM MODELS BASICALLY HAD FOG AND TEMPS AROUND 34F AT KRST ALL DAY TODAY. NCEP HIRES ARW MODELS...WHICH ARE DOING BETTER WITH DEWPOINTS BUT STILL TOO HIGH...THIS TIME TONIGHT DO NOT SHOW FOG. REGARDING LOW...THE HIGH CLOUDS TONIGHT WILL KEEP TEMPERATURES UP SOMEWHAT...BUT THE DRY AIRMASS ALSO SUPPORTS READINGS FALLING...ESPECIALLY IN THE TYPICAL COLD SPOTS. TRENDED TOWARDS THE COLDER SIDE OF GUIDANCE. ON MONDAY...850MB TEMPS ARE STILL HOLDING AROUND 8C...SO EXPECTING HIGHS SIMILAR TO TODAY. ONLY DIFFERENCE WOULD BE OUT WEST WHERE LESSER SNOW SHOULD ALLOW FOR WARMER TEMPERATURES. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 230 PM CDT SUN MAY 5 2013 MONDAY NIGHT THROUGH WEDNESDAY...ONLY MAIN CONCERN FROM A PRECIPITATION PERSPECTIVE IS THE UPPER LOW SITUATED OVER CENTRAL SOUTH DAKOTA. HANDLING OF THIS UPPER LOW HAS BEEN VERY PROBLEMATIC RUN TO RUN AND BETWEEN MODEL TO MODEL. THERE HAS BEEN A GENERAL SLOW DOWN IN BRINGING THIS UPPER LOW TOWARDS THE AREA...WHICH MAKES SENSE AS IT IS CAUGHT IN A LACK OF FLOW BETWEEN THE NORTHERN AND SOUTHERN STREAMS. THE WAY MODELS EVENTUALLY BRING IT TOWARDS THE AREA IS FROM A NORTHERN STREAM TROUGH DROPPING INTO SOUTH CENTRAL CANADA...THUS PICKING UP THE UPPER LOW. THE 05.12Z GFS IS THE FASTEST SOLUTION... AND QUITE A BIT FASTER COMPARED TO ITS 05.06Z GFS...IMPACTING THE AREA DURING THE DAY WEDNESDAY. 05.12Z NAM/UKMET/CANADIAN AND 05.00Z/05.12Z ECMWF ARE SLOWER. BELIEVE SLOWER IS THE WAY TO GO...WHICH WOULD KEEP ANY PRECIPITATION FORCED BY THE UPPER LOW MOSTLY WEST OF THE AREA. THUS HAVE KEPT ANY PRECIPITATION CHANCES LOW AND CONFINED TO WESTERN SECTIONS. OTHERWISE...DRY CONDITIONS WILL PREVAIL UNDER THE INFLUENCE OF HIGH PRESSURE AND LITTLE IN THE WAY OF FLOW ALOFT. 850MB TEMPS HOLD IN THE 8-10C RANGE FOR BOTH TUESDAY AND WEDNESDAY...WHICH SHOULD YIELD HIGHS IN THE 70S BOTH DAYS WITH JUST SOME SCATTERED CLOUDS AROUND. A DRY AIRMASS ACCOMPANYING THE HIGH...LIGHT WINDS AND THE SCATTERED CLOUDS LIKELY TO ALLOW FOR DECENT COOLING AT NIGHT. STAYED TOWARDS THE COLD END OF GUIDANCE...PARTICULARLY FOR THE TYPICAL COLD SPOTS. WEDNESDAY NIGHT THROUGH SUNDAY...FOCUS AT THE BEGINNING OF THIS PERIOD REMAINS ON THE UPPER LOW AND A COLD FRONTAL BOUNDARY THAT LOOKS TO ACCOMPANY THIS UPPER LOW...AS WELL AS THE AFOREMENTIONED NORTHERN STREAM SHORTWAVE TROUGH. AS MENTIONED THE 05.12Z GFS WAS A BIT FAST WITH THE UPPER LOW...THUS PREFER THE SLOWER 05.00Z/05.12Z ECMWF. EITHER SOLUTION REQUIRES AT LEAST SOME CHANCES OF SHOWERS AND THUNDERSTORMS WITH THE COLD FRONTAL PASSAGE AND EVENTUALLY UPPER LOW. IT APPEARS THE COLD FRONT WILL SLOWLY DROP SOUTHEAST THROUGH THE AREA WEDNESDAY NIGHT THROUGH THURSDAY...WITH THE BEST CHANCES OF PRECIPITATION OVER SOUTHERN PORTIONS OF THE AREA CLOSER TO THE PROGGED UPPER LOW. CANADIAN HIGH PRESSURE BUILDS IN FOR FRIDAY...YIELDING DRIER AND SLIGHTLY COOLER CONDITIONS WITH 850MB TEMPS OF 6-8C. MODELS CONTINUE TO HINT AT BIG CHANGES FOR THE WEEKEND WITH THE 05.12Z ECMWF/GFS/CANADIAN/GFS ENSEMBLES AND ECMWF ENSEMBLES ALL SHOWING A POTENT TROUGH DROPPING DOWN INTO THE WESTERN GREAT LAKES REGION. THIS TROUGH CURRENTLY IS IN THE ARCTIC NORTH OF SIBERIA... THUS EXPECTING A DECENT COLD SHOT. IN FACT...850MB TEMPS ARE PROGGED TO PLUMMET TO -4 TO -6C BY 12Z SUNDAY OVER THE FORECAST AREA. A COLD FRONT LOOKS TO RACE AHEAD OF THIS POTENT TROUGH...WHICH MEANS BETWEEN THE TWO A LIKELY DEFORMATION BAND OF LIGHT PRECIPITATION. THUS...CHANCES OF SHOWERS ARE IN THE FORECAST FOR SATURDAY. TEMPERATURES SATURDAY WILL BE TRICKY...ALL DEPENDING ON WHEN THE FRONT COMES THROUGH. IF IT IS SLOWER...850MB TEMPS OF 6-8C WOULD SUPPORT MOST LOCATIONS TOPPING OUT INTO THE 60S AND POSSIBLY EVEN LOW 70S LIKE THE 05.00Z ECMWF. ON THE OTHER HAND...A FASTER SOLUTION LIKE THE 05.12Z ECMWF/CANADIAN WOULD BE IN THE 50S...OR COLDER. FOR NOW WENT WITH THE COMPROMISE AND FOLLOWED A BLEND OF GUIDANCE FOR TEMPERATURES. DEFINITELY COLDER BUT DRIER FOR SUNDAY AS THE 850MB THERMAL TROUGH AND CANADIAN AIR MOVE IN. HIGHS LIKELY TO ONLY TOP OUT IN THE 50S ON SUNDAY...A GOOD 15 DEGREES OR SO BELOW NORMAL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1228 PM CDT SUN MAY 5 2013 MID/UPPER LEVEL RIDGE OF HIGH PRESSURE WILL KEEP THE AREA UNDER VFR CONDITIONS GOING INTO TONIGHT WITH JUST A FEW CIRRUS NOTED. GOOD MIXING THROUGH THE BOUNDARY LAYER TODAY AND DRIER/LIGHT NORTHERLY FLOW THROUGH TONIGHT EXPECTED TO PREVENT ANY WIDESPREAD FOG ACTIVITY. DID INCLUDE 4SM BR AT KRST/KLSE IN THE 08-14Z TIME FRAME. OTHERWISE...VFR CONDITIONS/LIGHT WINDS WILL CONTINUE THROUGH MONDAY AS THE RIDGE OF HIGH PRESSURE HOLDS OVER THE AREA. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...DAS