Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/30/16


AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
1157 AM PDT MON MAR 28 2016 UPDATED AVIATION DISCUSSION .SYNOPSIS... A LOW PRESSURE SYSTEM APPROACHING FROM THE NORTH WILL BRING COOLER WEATHER...GUSTY WINDS...AND SCATTERED SHOWERS TODAY...DECREASING TO ISOLATED SHOWERS BY WEDNESDAY. WARMER AND AND DRIER WEATHER IS EXPECTED THURSDAY INTO NEXT WEEKEND AS HIGH PRESSURE RETURNS. && .SHORT TERM...(TDY-WED) COLD UPPER LEVEL LOW PRESSURE SYSTEM CURRENTLY CENTERED NEAR LAKE TAHOE IS FORECASTED TO CONTINUE DROPPING SOUTHWARD THROUGH THE AFTERNOON...CENTERED NEAR THE CALIFORNIA/NEVADA LINE. ON THE BACK SIDE OF THIS UPPER LEVEL LOW PRESSURE SYSTEM...THERE IS STRONG UPPER LEVEL WEST TO NORTHWEST WIND SUPPORT THAT WILL GENERATE WIDESPREAD GUSTY WINDS ACROSS SOUTHWEST CALIFORNIA TODAY. IN FACT...BOTH 12Z GFS AND NAM MODELS SHOWING A STRONG 105 KNOT JET THAT WILL SWEEP ACROSS THE CENTRAL COAST AND UPPER DESERTS TODAY THAT WILL HELP TO FUEL THIS STRONG WIND EVENT. EVEN AT 500 MB LEVEL...IMPRESSIVE 80 TO 90 KNOT WEST TO NORTHWEST WINDS PROJECTED FOR THIS AFTERNOON. IN ADDITION TO THE STRONG UPPER LEVEL WIND SUPPORT...THERE IS STRONG ONSHORE FLOW TODAY TO A DEVELOPING 997 MB SURFACE LOW NEAR LAS VEGAS. CURRENT PRESSURE GRADIENTS SHOWING THE SHARP ONSHORE TRENDS ALREADY OCCURRING...WITH LAX-TONOPAH AT +13.6 MB AND SANTA MARIA-LAS VEGAS AT +14.6 MB (AS OF 9 AM). THE ABOVE MENTIONED STRONG ONSHORE FLOW AND STRONG UPPER LEVEL WIND SUPPORT WILL FOCUS THE STRONGEST WINDS ACROSS THE DESERTS TODAY. THE STRONG UPPER LEVEL WIND SUPPORT ACROSS MOUNTAIN RIDGETOPS AND ABOVE WILL CREATE FAVORABLE CONDITIONS FOR STRONG MOUNTAIN WAVE WIND CONDITIONS ACROSS INTERIOR SECTIONS TODAY...ESPECIALLY THE DESERTS. AS A RESULT...A HIGH WIND WARNING IS IN EFFECT FOR THE ANTELOPE VALLEY...WHERE DAMAGING WIND GUSTS UP TO 60 MPH WILL BE LIKELY. IN ADDITION...CONDITIONS WILL BE FAVORABLE FOR DUST STORM DEVELOPMENT ACROSS THE ANTELOPE VALLEY TODAY...SO MOTORISTS SHOULD BE ALERT FOR THE POSSIBILITY OF RESTRICTED VISIBILITIES DOWN TO NEAR ZERO AT TIMES. OTHERWISE WIND ADVISORIES IN EFFECT FOR MANY PORTIONS OF SOUTHWEST CALIFORNIA TODAY...WITH MANY AREAS GUSTING BETWEEN 40 AND 55 MPH (ESPECIALLY ACROSS THE MOUNTAINS AND COASTAL AREAS). WINDS THIS STRONG WILL BRING THE POTENTIAL FOR DOWNED TREES. THE STRENGTHENING ONSHORE FLOW AND LOWERING HEIGHTS ALSO GENERATED A MOIST LAYER RANGING BETWEEN 4000 AND 6000 FEET THIS MORNING WHICH HAS YIELDED WIDESPREAD DRIZZLE AND LIGHT RAIN . AUTOMATED RAIN GAUGES SHOWED MANY AREAS SOUTH OF POINT CONCEPTION RECEIVING MEASURABLE RAINFALL (LESS THAN A TENTH OF AN INCH). THE BEST CHANCE OF SHOWERS FOR THE REMAINDER OF THE DAY WILL CONTINUE TO BE LOS ANGELES COUNTY WHERE THERE WILL BE THE DEEPEST LOW LEVEL MOISTURE AND BEST CYCLONIC FLOW. *** FROM PREVIOUS DISCUSSION *** TUESDAY WILL BE A MUCH LESS ACTIVE DAY AS THE EFFECTS OF THE TROF WANE. RESIDUAL NORTHERLY WINDS AND SOME WEAK INSTABILITY WILL ALLOW A SLIGHT CHC OF SHOWERS ON THE NORTH SLOPES AND THE ERN SAN GABRIELS. OTHERWISE SKIES WILL BE PARTLY CLOUDY. MAX TEMPS WILL BUMP UP ABOUT 4 DEGREES BUT WILL STILL BE BLO NORMAL. REALLY NOT MUCH CHANGE FOR WEDNESDAY. THE WEATHER WILL REMAIN DOMINATED BY BY A HUMONGOUS COOL UPPER LOW SITTING OVER NEVADA AND COVERING THE ENTIRE AREA FROM THE ROCKY MTNS WESTWARD. THE CHC OF SHOWERS OVER THE NORTH SLOPES WILL END LEAVING ONLY A SLIGHT CHC OF A SHOWER OVER THE ERN SAN GABRIELS. SKIES WILL REMAIN PARTLY CLOUDY AND MAX TEMPS WILL REMAIN 4 TO 8 DEGREES BLO NORMAL. .LONG TERM...(THU-SUN) ALL MDLS AGREE THAT LATER WEDNESDAY NIGHT THE UPPER LOW WILL OPEN UP INTO A BROAD TROF AND THEN WILL SLOWLY MOVE TO THE EAST DURING THE DAY ON THURSDAY. AT SAME TIME A HIGH AMPLITUDE BUT SKINNY RIDGE WILL SET UP ACROSS THE EAST PAC. THURSDAY WILL BE A TRANSITION DAY BETWEEN THE TROF AND THE RIDGE. SKIES WILL BE MOSTLY CLEAR AND MAX TEMPS WILL RISE TO NEAR NORMAL AS HGTS RISE AND ONSHORE FLOW DECREASES. TWO WARM AND SUNNY DAYS ON TAP FOR FRIDAY AND SATURDAY AS THE RIDGE MOVES OVER THE STATE. THERE IS NOT THAT MUCH OFFSHORE FLOW SO WHILE MAX TEMPS WILL RISE TO ABOVE NORMAL THEY WILL NOT BE SEARINGLY HOT. THE RIDGE WEAKENS ON SUNDAY AND ONSHORE FLOW SETS UP AND STRENGTHENS. SKIES WILL LIKELY REMAIN MOSTLY SUNNY BUT MAX TEMPS WILL FALL SEVERAL DEGREES FROM SATURDAYS WARM READINGS AND WILL ONLY BE A DEGREE OR TWO ABOVE NORMAL. && .AVIATION...28/1800Z. AT 1800Z...THERE WAS NO MARINE LAYER KLAX. LOW CONFIDENCE IN THE 18Z TAFS DUE TO LOW CIGS...GUSTY WINDS AND ISOLATED SHOWERS. CLEARING AND RISING OF CIGS MAY DIFFER BY +/- 3 HOURS. THERE IS A 30 PERCENT CHANCE THAT IFR TO MVFR CIGS FORM BETWEEN 03Z AND 09Z AND LAST 6 TO 10 HOURS FOR KLAX KBUR KLGB AND KOXR. THERE MAY BE AREAS OF BLOWING DUST AND SAND IN THE ANTELOPE VALLEY...WITH VSBYS LOCALLY DOWN TO NEAR ZERO AT TIMES THIS AFTERNOON AND EVENING. LLWS AND STRONG UDDF ARE LIKELY AROUND THE MTNS AND ANTELOPE VALLEY INCLUDING KBUR KSBA KPMD AND KWJF. KLAX...LOW CONFIDENCE IN CIG FORECAST...MODERATE CONFIDENCE IN WINDS. THERE IS A 30 PERCENT CHANCE THAT IFR TO MVFR CIGS FORM BETWEEN 03Z AND 09Z AND LAST 3 TO 8 HOURS. KBUR...LOW CONFIDENCE IN CIGS THROUGH 04Z...BUT VFR LIKELY AFTER 04Z. LOW CONFIDENCE IN WIND SHIFT TIMING AND MAGNITUDE 21Z TO 04Z. THERE IS A 30 PERCENT CHANCE OF MODERATE LLWS BETWEEN 05Z AND 15Z. && .MARINE...28/900 AM PDT. HIGH CONFIDENCE THAT GALE FORCE WINDS TO 40 KT WITH LARGE STEEP SEAS CURRENTLY OVER THE OUTER WATERS WILL EXPAND TO COVER ALL WATERS BY THIS AFTERNOON AND CONTINUE THROUGH TONIGHT. THE GALE WINDS WILL TRANSITION TO SMALL CRAFT CONDITIONS LATE TONIGHT AND CONTINUE THROUGH TUESDAY NIGHT EVERYWHERE...EXCEPT FOR THE NEAR SHORE WATERS OFF THE CENTRAL COAST. THERE IS A 30 PERCENT CHANCE OF SMALL CRAFT CONDITIONS ACROSS THE OUTER WATERS WEDNESDAY AND AGAIN ON FRIDAY. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...WIND ADVISORY IN EFFECT UNTIL 9 PM PDT THIS EVENING FOR ZONES 34>37-40-41-44>46. (SEE LAXNPWLOX). WIND ADVISORY IN EFFECT UNTIL 3 AM PDT TUESDAY FOR ZONES 39-52>54. (SEE LAXNPWLOX). HIGH WIND WARNING IN EFFECT UNTIL 3 AM PDT TUESDAY FOR ZONE 59. (SEE LAXNPWLOX). WIND ADVISORY IN EFFECT UNTIL 9 PM PDT TUESDAY FOR ZONE 87. (SEE LAXNPWLOX). PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL NOON PDT TODAY FOR ZONE 645. (SEE LAXMWWLOX). GALE WARNING IN EFFECT UNTIL 9 PM PDT THIS EVENING FOR ZONE 645. (SEE LAXMWWLOX). GALE WARNING IN EFFECT UNTIL 3 AM PDT TUESDAY FOR ZONES 650-655-670-673-676. (SEE LAXMWWLOX). && $$ PUBLIC...GOMBERG AVIATION...KITTELL/MUNROE MARINE...KITTELL/MUNROE SYNOPSIS...SWEET WEATHER.GOV/LOSANGELES
Area Forecast Discussion...UPDATED National Weather Service Reno NV 1115 AM PDT MON MAR 28 2016 .UPDATE... We have allowed the Winter Weather Advisory to expire at 11am. There are still a few locations with chain controls in western NV, although road conditions will continue to improve through the day as the road surfaces warm up and melt off the snow. Additional light accumulations of up to an inch or less are expected. Snow showers will continue to shift further south of Highway 50 during the afternoon and this evening. Hoon && .PREVIOUS DISCUSSION... /Issued 933 AM PDT MON MAR 28 2016/ UPDATE... Heavy snow amounts are being reported around the Reno- Sparks area this morning with many locations about 5 to 10 inches so far--a classic "slider" type system. HRRR model is showing additional snow around the I-80 corridor through about 11am this morning, then shifting south towards Highway 50 late morning and into the afternoon. Additional snowfall of up to a few inches will be possible over the next few hours, but snow will get lighter and have trouble sticking as we get into the afternoon hours. Also, road conditions should be improving as well as roads start to melt off. Unstable conditions will keep snow showers and clouds around through the afternoon as well, temperatures may struggle to reach 40 degrees in the valleys of western NV. Hoon AVIATION... Moderate to heavy snow at KRNO is causing IFR CIG/VIS. These conditions will likely continue through the morning at KRNO, with conditions beginning to improve this afternoon. Additional snowfall is expected, but with temperatures rising only an inch or two of slush will accumulate on the runways. Conditions have improved to VFR at KTVL, but as showers pick up this afternoon, we could have conditions lower back down to MVFR/IFR. Hoon PREVIOUS DISCUSSION... /Issued 619 AM PDT MON MAR 28 2016/ UPDATE... Band of moderate to occasionally heavy snow continues along and north of the I-80 corridor with the southern edge of the band sliding ever so slowly south toward Carson City-Dayton. Snow amounts have been in the 2 to 5 inch range thus far in the heavier snow bands with gusty north winds resulting in localized blowing and drifting snow. Latest finer scale HRRR model run indicates only a very slow drift south and east during the morning hours and then accelerating southward around 18-20z. There may be occasional letups at KTRK-KRNO-KLOL-KCXP, but given the stationary nature of this system, CIGS/VSBY will remain restricted with MVFR/periods of IFR continuing through 18z. PREVIOUS DISCUSSION... /Issued 337 AM PDT MON MAR 28 2016/ UPDATE... The band continues to develop near and north of I-80 at this hour. Latest models keep the band in this vicinity through 8 AM before it slowly shifts south. Updating to keep most snow accumulation near and north of I-80 and reducing accumulations near and south of Highway 50. Also canceling the advisory for southern Lyon County as the band will not make it there until late morning. By then, solar heating will be enough to preclude any road accumulation. Wallmann SYNOPSIS... A strong cold front will continue moving through the Sierra and Western Nevada this morning. Snow showers will occur behind the front today with the heaviest band expected along I-80 this morning. The upper low will continue to influence area weather into Wednesday as it slowly pulls east with scattered showers and cold temperatures. Mild and dry weather returns for late week. PREVIOUS DISCUSSION... /Issued 238 AM PDT MON MAR 28 2016/ SYNOPSIS... A strong cold front will continue moving through the Sierra and Western Nevada this morning. Snow showers will occur behind the front today with the heaviest band expected along I-80 this morning. The upper low will continue to influence area weather into Wednesday as it slowly pulls east with scattered showers and cold temperatures. Mild and dry weather returns for late week. SHORT TERM... The snow event is getting underway as I write this. The surface cold front is now along a line from Portola to Palomino Valley and then almost to Highway 50 in Churchill County. Showers have developed west of the crest and are moving east along the boundary. Currently, temps are mild from I-80 southward and around 40-45 degrees, but are in the 30s behind the front. With precip now moving in along I-80, areas below 5000 feet will start as rain, but expect it to change to snow north of Highway 50 by 6 AM. As for the band, the NAM/GFS/HRRR are hitting the I-80 corridor the hardest. The NAM actually shows close to 1" of water in the Reno/Sparks North Valleys. This is likely overdone, but 1/2" seems plausible. With the cold air coming in, this will mostly be snow and 3-6" of snow seems likely along the I-80 corridor above 4500 feet. Lighter amounts farther south away from this main band. Roads will be slick this morning near I-80 and also into eastern Plumas County due to the snow. Be prepared for a longer than normal commute and the advisories will continue as is. One thing to note is that the band doesn`t make it to southern Lyon County until late morning. If this occurs, any snow that falls will melt on impact, especially on the roads due to the higher late March sun angle. As we move into the afternoon, the cold pool moves overhead and expect snow showers to continue across the area, but little accumulation due to solar heating. Any lake effect for Pyramid Lake looks less likely today as models now show the winds being more Northeast, and also 30+ kts at 700 mb. This is in addition to the diurnal minimum in LES during the afternoon. Still, plenty of showers will be around in the instability. The upper low then only slowly pulls away into Wednesday. A northeast flow will continue on the backside Tuesday and Wednesday. Showers look more likely Tuesday as the cold pool remains close enough. Wednesday the instability is weaker and more south of I-80 so just have a slight chance of showers there. Temperatures will slowly moderate from today`s much below average readings, but remain below normal into Wednesday. Wallmann LONG TERM...Thursday through Sunday... Only minor changes were made as the previous forecast thinking is on track. Temperatures will begin to warm Thursday although northeast flow aloft will persist for one more day and keep the warmup slow initially. This will be the poorest day for mixing as surface warming will not keep up with warming temperatures aloft, resulting in moderate inversions. Friday, we expect temperatures to jump 7-10 degrees with a better mixing profile. For the weekend, instability and weak shortwave may be sufficient for isolated showers (probably not much more) across far northeast CA and northwest NV. Given the northern track of this shortwave, showers in the Sierra are unlikely and we have removed the mention there. Otherwise, it is going to be an unseasonably mild weekend with highs in the upper 50s to around 60 Sierra valleys and mid 60s to low 70s western NV valleys. AVIATION... A cold front moving southward into western NV early this morning will continue to drop south and allow colder air to settle into the I-80/Hwy 50 corridors. Meanwhile, instability continues to increase as upper low drops into the region with band of rain and snow intensifying near and north of I-80. Some models are indicating some impressive bands of precipitation developing through 15z and right now, it appears that zone will be very close to where it is setting up currently which would have bigger impacts for KTRK-KRNO-KLOL. Temps and dewpoints are currently too warm for much accumulation below 5000 feet and this will likely remain the case outside of heavier bands of precipitation even though we do anticipate a changeover to all snow during the morning hours. So the key to getting accumulation on area runways will be location of most intense snow bands prior to 16z. Light accumulations are already occurring at KTRK and we will just have to monitor radar trends for KRNO-KLOL. The band is forecast to slide south into Mono-Mineral County this afternoon and evening with some light accumulations possible at KMMH near or after sundown. Right now, due to the timing of the band (later in the morning) at KTVL-KCXP-KNFL, accumulations look minimal. There could still be some brief slushy accumulations if snow showers become sufficiently heavy. But any accumulation will melt quickly once the snow showers pass. Otherwise, expect periods of IFR/MVFR CIGS/VSBY during snow showers with terrain obscurement, especially close to the Sierra. Hohmann && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$ For more information from the National Weather Service visit... http://weather.gov/reno
AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
944 AM PDT MON MAR 28 2016 .SYNOPSIS... A LOW PRESSURE SYSTEM APPROACHING FROM THE NORTH WILL BRING COOLER WEATHER...GUSTY WINDS...AND SCATTERED SHOWERS TODAY...DECREASING TO ISOLATED SHOWERS BY WEDNESDAY. WARMER AND AND DRIER WEATHER IS EXPECTED THURSDAY INTO NEXT WEEKEND AS HIGH PRESSURE RETURNS. && .SHORT TERM...(TDY-WED) COLD UPPER LEVEL LOW PRESSURE SYSTEM CURRENTLY CENTERED NEAR LAKE TAHOE IS FORECASTED TO CONTINUE DROPPING SOUTHWARD THROUGH THE AFTERNOON...CENTERED NEAR THE CALIFORNIA/NEVADA LINE. ON THE BACK SIDE OF THIS UPPER LEVEL LOW PRESSURE SYSTEM...THERE IS STRONG UPPER LEVEL WEST TO NORTHWEST WIND SUPPORT THAT WILL GENERATE WIDESPREAD GUSTY WINDS ACROSS SOUTHWEST CALIFORNIA TODAY. IN FACT...BOTH 12Z GFS AND NAM MODELS SHOWING A STRONG 105 KNOT JET THAT WILL SWEEP ACROSS THE CENTRAL COAST AND UPPER DESERTS TODAY THAT WILL HELP TO FUEL THIS STRONG WIND EVENT. EVEN AT 500 MB LEVEL...IMPRESSIVE 80 TO 90 KNOT WEST TO NORTHWEST WINDS PROJECTED FOR THIS AFTERNOON. IN ADDITION TO THE STRONG UPPER LEVEL WIND SUPPORT...THERE IS STRONG ONSHORE FLOW TODAY TO A DEVELOPING 997 MB SURFACE LOW NEAR LAS VEGAS. CURRENT PRESSURE GRADIENTS SHOWING THE SHARP ONSHORE TRENDS ALREADY OCCURRING...WITH LAX-TONOPAH AT +13.6 MB AND SANTA MARIA-LAS VEGAS AT +14.6 MB (AS OF 9 AM). THE ABOVE MENTIONED STRONG ONSHORE FLOW AND STRONG UPPER LEVEL WIND SUPPORT WILL FOCUS THE STRONGEST WINDS ACROSS THE DESERTS TODAY. THE STRONG UPPER LEVEL WIND SUPPORT ACROSS MOUNTAIN RIDGETOPS AND ABOVE WILL CREATE FAVORABLE CONDITIONS FOR STRONG MOUNTAIN WAVE WIND CONDITIONS ACROSS INTERIOR SECTIONS TODAY...ESPECIALLY THE DESERTS. AS A RESULT...A HIGH WIND WARNING IS IN EFFECT FOR THE ANTELOPE VALLEY...WHERE DAMAGING WIND GUSTS UP TO 60 MPH WILL BE LIKELY. IN ADDITION...CONDITIONS WILL BE FAVORABLE FOR DUST STORM DEVELOPMENT ACROSS THE ANTELOPE VALLEY TODAY...SO MOTORISTS SHOULD BE ALERT FOR THE POSSIBILITY OF RESTRICTED VISIBILITIES DOWN TO NEAR ZERO AT TIMES. OTHERWISE WIND ADVISORIES IN EFFECT FOR MANY PORTIONS OF SOUTHWEST CALIFORNIA TODAY...WITH MANY AREAS GUSTING BETWEEN 40 AND 55 MPH (ESPECIALLY ACROSS THE MOUNTAINS AND COASTAL AREAS). WINDS THIS STRONG WILL BRING THE POTENTIAL FOR DOWNED TREES. THE STRENGTHENING ONSHORE FLOW AND LOWERING HEIGHTS ALSO GENERATED A MOIST LAYER RANGING BETWEEN 4000 AND 6000 FEET THIS MORNING WHICH HAS YIELDED WIDESPREAD DRIZZLE AND LIGHT RAIN . AUTOMATED RAIN GAUGES SHOWED MANY AREAS SOUTH OF POINT CONCEPTION RECEIVING MEASURABLE RAINFALL (LESS THAN A TENTH OF AN INCH). THE BEST CHANCE OF SHOWERS FOR THE REMAINDER OF THE DAY WILL CONTINUE TO BE LOS ANGELES COUNTY WHERE THERE WILL BE THE DEEPEST LOW LEVEL MOISTURE AND BEST CYCLONIC FLOW. *** FROM PREVIOUS DISCUSSION *** TUESDAY WILL BE A MUCH LESS ACTIVE DAY AS THE EFFECTS OF THE TROF WANE. RESIDUAL NORTHERLY WINDS AND SOME WEAK INSTABILITY WILL ALLOW A SLIGHT CHC OF SHOWERS ON THE NORTH SLOPES AND THE ERN SAN GABRIELS. OTHERWISE SKIES WILL BE PARTLY CLOUDY. MAX TEMPS WILL BUMP UP ABOUT 4 DEGREES BUT WILL STILL BE BLO NORMAL. REALLY NOT MUCH CHANGE FOR WEDNESDAY. THE WEATHER WILL REMAIN DOMINATED BY BY A HUMONGOUS COOL UPPER LOW SITTING OVER NEVADA AND COVERING THE ENTIRE AREA FROM THE ROCKY MTNS WESTWARD. THE CHC OF SHOWERS OVER THE NORTH SLOPES WILL END LEAVING ONLY A SLIGHT CHC OF A SHOWER OVER THE ERN SAN GABRIELS. SKIES WILL REMAIN PARTLY CLOUDY AND MAX TEMPS WILL REMAIN 4 TO 8 DEGREES BLO NORMAL. .LONG TERM...(THU-SUN) ALL MDLS AGREE THAT LATER WEDNESDAY NIGHT THE UPPER LOW WILL OPEN UP INTO A BROAD TROF AND THEN WILL SLOWLY MOVE TO THE EAST DURING THE DAY ON THURSDAY. AT SAME TIME A HIGH AMPLITUDE BUT SKINNY RIDGE WILL SET UP ACROSS THE EAST PAC. THURSDAY WILL BE A TRANSITION DAY BETWEEN THE TROF AND THE RIDGE. SKIES WILL BE MOSTLY CLEAR AND MAX TEMPS WILL RISE TO NEAR NORMAL AS HGTS RISE AND ONSHORE FLOW DECREASES. TWO WARM AND SUNNY DAYS ON TAP FOR FRIDAY AND SATURDAY AS THE RIDGE MOVES OVER THE STATE. THERE IS NOT THAT MUCH OFFSHORE FLOW SO WHILE MAX TEMPS WILL RISE TO ABOVE NORMAL THEY WILL NOT BE SEARINGLY HOT. THE RIDGE WEAKENS ON SUNDAY AND ONSHORE FLOW SETS UP AND STRENGTHENS. SKIES WILL LIKELY REMAIN MOSTLY SUNNY BUT MAX TEMPS WILL FALL SEVERAL DEGREES FROM SATURDAYS WARM READINGS AND WILL ONLY BE A DEGREE OR TWO ABOVE NORMAL. && .AVIATION...28/1100Z. AT 0800Z...THE MARINE LAYER DEPTH AT KLAX WAS 2700 FT DEEP. THE TOP OF THE INVERSION WAS LOCATED AT 3300 FT WITH A TEMPERATURE OF 12 DEGREES C. WIDESPREAD MVFR CIGS ACROSS THE REGION THIS MORNING...WITH LIFR TO VLIFR CONDS IN THE FOOTHILLS AND ON THE COASTAL SLOPES. THERE COULD BE LOCAL DRIZZLE OR LIGHT RAIN THIS MORNING...ESPECIALLY IN THE FOOTHILLS OF L.A. COUNTY. EXPECT CIGS TO SCATTER OUT IN MOST AREAS BY LATE MORNING...EXCEPT ACROSS L.A. COUNTY...ESPECIALLY IN THE VALLEYS AND FOOTHILLS...WHERE CIGS MAY LINGER THROUGH MUCH OF THE DAY. HOWEVER...CIGS SHOULD CONT TO RISE...WITH MOSTLY VFR CONDS EXPECTED BY LATE MORNING. STRONG AND GUSTY W TO NW WINDS WILL DEVELOP IN MANY AREAS THIS AFTERNOON. WINDS WILL BE STRONGEST NEAR THE COAST AND IN HIGHER ELEVATIONS. PARTICULARLY STRONG WINDS ARE EXPECTED IN THE ANTELOPE VALLEY...WHERE SUSTAINED WINDS COULD REACH OR EXCEED 40 KNOTS...AND GUSTS COULD REACH 55 TO POSSIBLY 60 KNOTS. THERE WILL BE AREAS OF BLOWING DUST AND SAND IN THE ANTELOPE VALLEY...WITH VSBYS LOCALLY DOWN TO NEAR ZERO AT TIMES THIS AFTERNOON AND EVENING. LLWS AND STRONG UDDF ARE LIKELY IN THE MTNS AND ANTELOPE VALLEY. KLAX...MODERATE CONFIDENCE IN THE 12Z TAF. THERE IS A 20 TO 30 PERCENT CHANCE THAT MVFR CIGS WILL LINGER THROUGH 18Z. KBUR...MODERATE CONFIDENCE IN THE 12Z TAF.THERE IS A 20 TO 30 PERCENT CHANCE THAT MVFR CIGS WILL LINGER THROUGH 18Z. && .MARINE...28/900 AM PDT. HIGH CONFIDENCE THAT GALE FORCE WINDS TO 40 KT WITH LARGE STEEP SEAS CURRENTLY OVER THE OUTER WATERS WILL EXPAND TO COVER ALL WATERS BY THIS AFTERNOON AND CONTINUE THROUGH TONIGHT. THE GALE WINDS WILL TRANSITION TO SMALL CRAFT CONDITIONS LATE TONIGHT AND CONTINUE THROUGH TUESDAY NIGHT EVERYWHERE...EXCEPT FOR THE NEAR SHORE WATERS OFF THE CENTRAL COAST. THERE IS A 30 PERCENT CHANCE OF SMALL CRAFT CONDITIONS ACROSS THE OUTER WATERS WEDNESDAY AND AGAIN ON FRIDAY. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...WIND ADVISORY IN EFFECT UNTIL 9 PM PDT THIS EVENING FOR ZONES 34>37-40-41-44>46. (SEE LAXNPWLOX). WIND ADVISORY IN EFFECT UNTIL 3 AM PDT TUESDAY FOR ZONES 39-52>54. (SEE LAXNPWLOX). HIGH WIND WARNING IN EFFECT UNTIL 3 AM PDT TUESDAY FOR ZONE 59. (SEE LAXNPWLOX). WIND ADVISORY IN EFFECT UNTIL 9 PM PDT TUESDAY FOR ZONE 87. (SEE LAXNPWLOX). PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL NOON PDT TODAY FOR ZONE 645. (SEE LAXMWWLOX). GALE WARNING IN EFFECT UNTIL 9 PM PDT THIS EVENING FOR ZONE 645. (SEE LAXMWWLOX). GALE WARNING IN EFFECT UNTIL 3 AM PDT TUESDAY FOR ZONES 650-655-670-673-676. (SEE LAXMWWLOX). && $$ PUBLIC...GOMBERG AVIATION...KITTELL/MUNROE MARINE...KITTELL/MUNROE SYNOPSIS...SWEET WEATHER.GOV/LOSANGELES
Area Forecast Discussion...UPDATED National Weather Service Reno NV 933 AM PDT MON MAR 28 2016 .UPDATE... Heavy snow amounts are being reported around the Reno- Sparks area this morning with many locations about 5 to 10 inches so far--a classic "slider" type system. HRRR model is showing additional snow around the I-80 corridor through about 11am this morning, then shifting south towards Highway 50 late morning and into the afternoon. Additional snowfall of up to a few inches will be possible over the next few hours, but snow will get lighter and have trouble sticking as we get into the afternoon hours. Also, road conditions should be improving as well as roads start to melt off. Unstable conditions will keep snow showers and clouds around through the afternoon as well, temperatures may struggle to reach 40 degrees in the valleys of western NV. Hoon && .AVIATION... Moderate to heavy snow at KRNO is causing IFR CIG/VIS. These conditions will likely continue through the morning at KRNO, with conditions beginning to improve this afternoon. Additional snowfall is expected, but with temperatures rising only an inch or two of slush will accumulate on the runways. Conditions have improved to VFR at KTVL, but as showers pick up this afternoon, we could have conditions lower back down to MVFR/IFR. Hoon && .PREVIOUS DISCUSSION... /Issued 619 AM PDT MON MAR 28 2016/ UPDATE... Band of moderate to occasionally heavy snow continues along and north of the I-80 corridor with the southern edge of the band sliding ever so slowly south toward Carson City-Dayton. Snow amounts have been in the 2 to 5 inch range thus far in the heavier snow bands with gusty north winds resulting in localized blowing and drifting snow. Latest finer scale HRRR model run indicates only a very slow drift south and east during the morning hours and then accelerating southward around 18-20z. There may be occasional letups at KTRK-KRNO-KLOL-KCXP, but given the stationary nature of this system, CIGS/VSBY will remain restricted with MVFR/periods of IFR continuing through 18z. PREVIOUS DISCUSSION... /Issued 337 AM PDT MON MAR 28 2016/ UPDATE... The band continues to develop near and north of I-80 at this hour. Latest models keep the band in this vicinity through 8 AM before it slowly shifts south. Updating to keep most snow accumulation near and north of I-80 and reducing accumulations near and south of Highway 50. Also canceling the advisory for southern Lyon County as the band will not make it there until late morning. By then, solar heating will be enough to preclude any road accumulation. Wallmann SYNOPSIS... A strong cold front will continue moving through the Sierra and Western Nevada this morning. Snow showers will occur behind the front today with the heaviest band expected along I-80 this morning. The upper low will continue to influence area weather into Wednesday as it slowly pulls east with scattered showers and cold temperatures. Mild and dry weather returns for late week. PREVIOUS DISCUSSION... /Issued 238 AM PDT MON MAR 28 2016/ SYNOPSIS... A strong cold front will continue moving through the Sierra and Western Nevada this morning. Snow showers will occur behind the front today with the heaviest band expected along I-80 this morning. The upper low will continue to influence area weather into Wednesday as it slowly pulls east with scattered showers and cold temperatures. Mild and dry weather returns for late week. SHORT TERM... The snow event is getting underway as I write this. The surface cold front is now along a line from Portola to Palomino Valley and then almost to Highway 50 in Churchill County. Showers have developed west of the crest and are moving east along the boundary. Currently, temps are mild from I-80 southward and around 40-45 degrees, but are in the 30s behind the front. With precip now moving in along I-80, areas below 5000 feet will start as rain, but expect it to change to snow north of Highway 50 by 6 AM. As for the band, the NAM/GFS/HRRR are hitting the I-80 corridor the hardest. The NAM actually shows close to 1" of water in the Reno/Sparks North Valleys. This is likely overdone, but 1/2" seems plausible. With the cold air coming in, this will mostly be snow and 3-6" of snow seems likely along the I-80 corridor above 4500 feet. Lighter amounts farther south away from this main band. Roads will be slick this morning near I-80 and also into eastern Plumas County due to the snow. Be prepared for a longer than normal commute and the advisories will continue as is. One thing to note is that the band doesn`t make it to southern Lyon County until late morning. If this occurs, any snow that falls will melt on impact, especially on the roads due to the higher late March sun angle. As we move into the afternoon, the cold pool moves overhead and expect snow showers to continue across the area, but little accumulation due to solar heating. Any lake effect for Pyramid Lake looks less likely today as models now show the winds being more Northeast, and also 30+ kts at 700 mb. This is in addition to the diurnal minimum in LES during the afternoon. Still, plenty of showers will be around in the instability. The upper low then only slowly pulls away into Wednesday. A northeast flow will continue on the backside Tuesday and Wednesday. Showers look more likely Tuesday as the cold pool remains close enough. Wednesday the instability is weaker and more south of I-80 so just have a slight chance of showers there. Temperatures will slowly moderate from today`s much below average readings, but remain below normal into Wednesday. Wallmann LONG TERM...Thursday through Sunday... Only minor changes were made as the previous forecast thinking is on track. Temperatures will begin to warm Thursday although northeast flow aloft will persist for one more day and keep the warmup slow initially. This will be the poorest day for mixing as surface warming will not keep up with warming temperatures aloft, resulting in moderate inversions. Friday, we expect temperatures to jump 7-10 degrees with a better mixing profile. For the weekend, instability and weak shortwave may be sufficient for isolated showers (probably not much more) across far northeast CA and northwest NV. Given the northern track of this shortwave, showers in the Sierra are unlikely and we have removed the mention there. Otherwise, it is going to be an unseasonably mild weekend with highs in the upper 50s to around 60 Sierra valleys and mid 60s to low 70s western NV valleys. AVIATION... A cold front moving southward into western NV early this morning will continue to drop south and allow colder air to settle into the I-80/Hwy 50 corridors. Meanwhile, instability continues to increase as upper low drops into the region with band of rain and snow intensifying near and north of I-80. Some models are indicating some impressive bands of precipitation developing through 15z and right now, it appears that zone will be very close to where it is setting up currently which would have bigger impacts for KTRK-KRNO-KLOL. Temps and dewpoints are currently too warm for much accumulation below 5000 feet and this will likely remain the case outside of heavier bands of precipitation even though we do anticipate a changeover to all snow during the morning hours. So the key to getting accumulation on area runways will be location of most intense snow bands prior to 16z. Light accumulations are already occurring at KTRK and we will just have to monitor radar trends for KRNO-KLOL. The band is forecast to slide south into Mono-Mineral County this afternoon and evening with some light accumulations possible at KMMH near or after sundown. Right now, due to the timing of the band (later in the morning) at KTVL-KCXP-KNFL, accumulations look minimal. There could still be some brief slushy accumulations if snow showers become sufficiently heavy. But any accumulation will melt quickly once the snow showers pass. Otherwise, expect periods of IFR/MVFR CIGS/VSBY during snow showers with terrain obscurement, especially close to the Sierra. Hohmann && .REV Watches/Warnings/Advisories... NV...Winter Weather Advisory until 11 AM PDT this morning NVZ003-004. CA...None. && $$ For more information from the National Weather Service visit... http://weather.gov/reno
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
901 AM MST MON MAR 28 2016 .SYNOPSIS... A STRONG WEATHER SYSTEM WILL BRING WINDY CONDITIONS THIS AFTERNOON AND EVENING WITH BLOWING DUST AT TIMES. THE SYSTEM WILL ALSO USHER IN MUCH COOLER TEMPERATURES BEGINNING TUESDAY. IN FACT TEMPERATURES WILL BE WELL BELOW NORMAL TUESDAY AND WEDNESDAY BEFORE A WARMING TREND BEGINS THURSDAY. PRECIPITATION CHANCES WILL BE QUITE MODEST AND LIMITED TO THE HIGHER TERRAIN. OVER THE WEEKEND...TEMPERATURES CLIMB ABOVE NORMAL. && .DISCUSSION... A PRE-FRONTAL REGIME CHARACTERIZES THE CURRENT SETUP ACROSS THE DESERT SOUTHWEST. MORNING DOWNSLOPE FLOW ACROSS SOUTH-CENTRAL AZ HAS BEEN STRONGER THAN NORMAL AS WELL AS SOUTHERLY FLOW UP THE CO RIVER VALLEY. HOWEVER...LOW-MID LEVEL WINDS ON AREA SOUNDINGS ARE FAR FROM BEING OFF THE CHART WITH REGARDS TO CLIMATOLOGY. THE SCENARIO IS A BIT CLEARER WHEN VIEWING THE NAEFS ANOMALIES...AS THE STRONGEST VALUES ARE STILL WELL OFF TO THE WEST AND DEVELOP LATER IN THE DAY AS THE DEEP-LAYERED LOW PRESSURE SYSTEM ACROSS THE GREAT BASIN DRIFTS FURTHER SOUTH AND EASTWARD. NO SIGNIFICANT CHANGES TO THE FORECAST ARE ANTICIPATED THIS MORNING. STILL EXPECTING BREEZY/WINDY CONDITIONS TO DEVELOP THIS AFTERNOON WITH AREAS OF BLOWING DUST AND REDUCED VSBYS POSSIBLE. TEMPERATURES WILL REMAIN A BIT ABOVE AVERAGE BEFORE A SIGNIFICANT COOLDOWN ARRIVES TOMORROW. && .PREVIOUS DISCUSSION... TODAY THROUGH THURSDAY... THE WEATHER SYSTEM OF INTEREST FOR OUR FORECAST AREA IS COVERING MUCH OF THE WESTERN CONUS EARLY THIS MORNING. THE ASSOCIATED COLD FRONT HAS REACHED SOUTHERN NEVADA AND PORTIONS OF SOUTHERN CALIFORNIA AS OF THIS WRITING. THE SYSTEM WILL CONTINUE TO ADVANCE SOUTHEASTWARD AS AN UPSTREAM RIDGE AMPLIFIES IN RESPONSE TO DEEPENING TROUGH OVER THE NORTH-CENTRAL PACIFIC. THE COLD FRONT WILL MOVE ACROSS SOUTHEAST CALIFORNIA THIS AFTERNOON...ACROSS WESTERN AND CENTRAL ARIZONA TONIGHT...AND REACH THE NEW MEXICO BORDER BY MIDDAY TUESDAY. THE MAIN CONCERN FOR TODAY IS THE WIND THIS AFTERNOON AND EVENING. AS IS OFTEN THE CASE...STRONGEST WINDS OVER OUR FORECAST AREA WILL BE SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA AND AN ADVISORY REMAINS IN EFFECT THERE...LESS WIND OVER SOUTH-CENTRAL ARIZONA. THE STRONG WINDS WILL OF COURSE KICK UP THE DUST. CONDITIONS WILL STILL BE BREEZY TUESDAY. THERE ARE STRONG HEIGHT FALLS AND DIV Q FORCING WITH THIS SYSTEM. HOWEVER...WITH MUCH OF THE SYSTEM TAKING AN OVERLAND TRAJECTORY ALONG WITH A POSITIVE TILT TO THE TROUGH PLUS RAIN SHADOWING EFFECTS...THERE WILL NOT BE MUCH MOISTURE ADVECTION FOR OUR AREA. THUS PRECIPITATION POTENTIAL CONTINUES TO BE LIMITED PRIMARILY TO THE NORTHERN HALF OF ARIZONA TUESDAY INTO THURSDAY...MAINLY TUESDAY. MUCH COOLER TEMPERATURES ARE IN STORE THOUGH. IN FACT...DESERT HIGHS WILL BE IN THE UPPER 60S TO LOW 70S TUESDAY AND WEDNESDAY WITH THE UPPER TROUGH LINGERING OVER THE GREAT BASIN AND DESERT SOUTHWEST. THE TROUGH STARTS DEPARTING THURSDAY AND TEMPERATURES START TO WARM UP BUT WITH READINGS STILL BELOW NORMAL. FRIDAY THROUGH SUNDAY... THE RIDGE BUILDS OVER THE INTERIOR WEST FRIDAY AND SATURDAY WITH TEMPERATURES CLIMBING ABOVE NORMAL AS A RESULT. MODELS DIVERGE MORE NOTICEABLY ON SUNDAY WITH GFS AND CMC FLATTENING THE RIDGE WHILE THE ECMWF DEPICTS A HIGHER AMPLITUDE. DIFFERENCES ARE NOT THAT GREAT IN REALITY. DIFFERENCES ARE MAINLY ASSOCIATED WITH HOW THEY HANDLE AN UPSTREAM TROUGH. ANTICIPATE ADDITIONAL WARMING SUNDAY AS THE LOWER LEVELS REALIZE THE FULL SUBSIDENCE WARMING FROM ALOFT. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... STRONGER WIND GUSTS DEVELOPING THIS AFTERNOON WILL BE THE PRIMARY AVIATION IMPACT WITH ONLY FEW-SCT MIDLEVEL DECKS BELOW AN INCREASING THICKER CIRRUS LAYER. AN EASTERLY SFC WIND THIS MORNING WILL SHIFT TOWARDS A SOUTHERLY CROSS RUNWAY COMPONENT LATE THIS MORNING. A FEW GUSTS TO 20KT MAY BE POSSIBLE WITH THIS CROSS WIND COMPONENT... BEFORE DIRECTIONS VEER MORE TOWARDS A SOUTHWEST DIRECTION BY MID AFTERNOON. CONFIDENCE IS VERY GOOD THAT GUSTS 25-30KT WILL BE LIKELY LATER THIS AFTERNOON. EXPECT WINDS TO PERSIST WITH A WESTERLY COMPONENT PAST MIDNIGHT AND OVER MOST OF THE NIGHTTIME HOURS TONIGHT. ALSO...MAY SEE CONDITIONS APPROACHING LOW LEVEL WIND SHEAR CRITERIA AT THE TAF SITES... INCLUDING KPHX...AFTER 9PM AS SURFACE WINDS DECOUPLE A BIT AND 30 PLUS KNOTS REMAIN FROM THE SOUTHWEST NEAR 2K FEET. FINALLY...WE MAY SEE SCT-BKN DECKS 6-8K FEET DEVELOP AFTER 06Z AND PERSIST INTO TUE MORNING BUT DO NOT EXPECT CIGS TO FALL AS LOW AS 5K AT PHOENIX OVERNIGHT. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... VERY STRONG AND GUSTY WINDS ALONG WITH BLOWING DUST WILL BE THE MAIN AVIATION IMPACTS THIS AFTERNOON. LIGHT VARIABLE TO SOUTHWEST WINDS WILL INCREASE AND BECOME STRONGER WITH OCCASIONAL GUSTS LATER THIS MORNING...WITH VERY STRONG GUSTS DEVELOPING BY EARLY AFTERNOON. CONFIDENCE IS VERY GOOD THAT FREQUENT SOUTHWEST GUSTS 30-40KT ALONG WITH BLOWING DUST OCCASIONALLY REDUCING VSBY INTO A MVFR CATEGORY WILL IMPACT TERMINAL SITES LATER THIS AFTERNOON. AFTER 03Z EXPECT PERSISTENT GUSTY SOUTHWEST WINDS NEAR 20KT AT THE TAF SITES CONTINUING WELL PAST MIDNIGHT. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... WEDNESDAY THROUGH SUNDAY...A DEEP LOW PRESSURE SYSTEM WILL CONTINUE TO AFFECT THE REGION WEDNESDAY THROUGH FRIDAY...WITH SLIGHT CHANCES OF SHOWERS MAINLY OVER THE HIGHER TERRAIN WELL EAST OF PHOENIX ON WEDNESDAY WITH DRIER CONDITIONS FOLLOWING. LESS WIND IS EXPECTED BY WEDNESDAY ALTHOUGH IT WILL BE BREEZY AT TIMES DURING THE AFTERNOON THURSDAY AND FRIDAY OVER SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA. MUCH COOLER HIGH TEMPERATURES WILL PERSIST WEDNESDAY WITH READINGS STAYING BELOW NORMAL UNTIL FRIDAY WHEN HIGHS WILL WARM INTO THE 80S OVER THE LOWER DESERTS. HUMIDITIES WILL STAY SOMEWHAT ELEVATED ON WEDNESDAY WITH READINGS MOSTLY 15 TO 25 PERCENT...WITH GRADUAL DRYING INTO FRIDAY. BY FRIDAY MANY LOWER DESERTS WILL FALL TO AROUND 10 PERCENT MINIMUM HUMIDITY. HIGH PRESSURE WILL GRADUALLY SETTLE BACK INTO THE REGION OVER THE WEEKEND WITH WARMING TEMPERATURES AND CONTINUED RELATIVELY DRY CONDITIONS. && .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM MST THIS EVENING FOR AZZ020-021. CA...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM PDT THIS EVENING FOR CAZ030>033. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...HIRSCH PREVIOUS DISCUSSION...AJ AVIATION...CB/MO FIRE WEATHER...CB/KUHLMAN/MEYERS
Area Forecast Discussion National Weather Service Sacramento CA 858 AM PDT MON MAR 28 2016 .SYNOPSIS... A cool weather system settles in over the interior West through mid-week resulting in cool and breezy weather for NorCal along with scattered showers over the mountains. Minor snowfall accumulations will be possible over the northern Sierra. Dry with warmer temperatures by end of the week. && .DISCUSSION... Good Morning from NWS Sacramento! No changes to this morning`s forecast package. Wind Advisory still in effect from 10 am to 7 pm today in the Sacramento Valley, Delta, and into the Northern San Joaquin Valley. The latest HRRR shows that the winds may not be as strong in the Northern San Joaquin valley compared to Sacramento Valley, but still on the breezy side. .Previous Discussion... Satellite imagery shows the strong vort dropping southward into NorCal as the cold upper low closes off over the PacNW. Showers, and a few thunderstorms, blossomed over the foothills and Sierra north of I-80 during the late night hours as the vort approached. Showers will continue to wrap-around into the northern Sierra today, and potentially the foothills and eastern portions of the valley this afternoon, as the low consolidates over the Great Basin. Main impacts will be centered around breezy northerly winds in the Central Valley and scattered to numerous showers over the northern Sierra where accumulating snow will be possible across the higher elevations at times into early Tuesday. Upper low forecast to shift a little further east on Tuesday limiting shower chances to mainly the northern Sierra. Surface pressure gradients expected to weaken for less breezy conditions across the region. Still a threat for a few lingering showers in the Sierra south of Tahoe into Wednesday, but ridging from the eastern Pacific builds back into NorCal for a return to dry and milder weather for most of the region. && .EXTENDED DISCUSSION (Friday THROUGH Monday) High pressure holds on over Northern California Friday resulting in another warm, sunny day. A couple weak waves moves across the area over the weekend bringing a slight chance of showers to northern mountains. Model diverge early next week with the GFS bringing another inside slider, while the ECMWF introduces a flat ridge transitioning into a broad, weak trough. Either way, nothing too exciting with the best chance of showers remaining across the mountains. JClapp && .AVIATION... Northerly flow aloft as upper low drops south into CA/NV. Cold front passing through NorCal this morning with a VFR Valley and northerly winds spreading south today. Local MVFR/IFR conditions assoc with frontal and possible showers over Sierra southward of Plumas county. Areas W-NW sfc wind gusts to 30 kts over mountains. Northerly sfc wind gusts 30 to 35 kts in northern Sac Valley after 14z and spreading southward into northern SJ Valley in afternoon. JClapp && .STO Watches/Warnings/Advisories... Wind Advisory until 7 PM PDT this evening for Carquinez Strait and Delta-Central Sacramento Valley-Northern Sacramento Valley- Northern San Joaquin Valley-Southern Sacramento Valley. && $$
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
843 AM PDT MON MAR 28 2016 .SYNOPSIS...AN UPPER LEVEL LOW DROPPING SOUTH INTO CALIFORNIA TODAY WILL RESULT IN COOL CONDITIONS...ALONG WITH SLIGHT SHOWER CHANCES OVER THE HILLS THIS AFTERNOON AND EVENING. IN ADDITION...LOCALLY STRONG AND GUSTY NORTHWEST WINDS WILL OCCUR TODAY...MAINLY NEAR THE COAST. SLIGHTLY COOLER THAN NORMAL TEMPERATURES WILL CONTINUE THROUGH MIDWEEK BEFORE A GRADUAL WARMING TREND OCCURS DURING THE SECOND HALF OF THE WEEK. && .DISCUSSION...AS OF 8:45 AM PDT MONDAY...GUSTY CONDITIONS THIS MORNING FOR A GOOD PORTION OF OUR CWA. IN FACT, PNS ISSUED EARLIER (SFOPNSMTR) LISTED A SLEW OF SPOTS OVER 20 MPH. WINDS WILL CONTINUE TO BE BLUSTERY TODAY DUE TO MODERATE PRESSURE GRADIENTS AT THE SURFACE PLUS AN UPPER LEVEL LOW DIVING IN FROM THE NORTH. QUITE POSSIBLE WE MAY SEE A FEW SPOTS HITTING WIND ADVISORY LEVELS, HOWEVER DURATION AND NUMBER OF LOCATIONS SHOULD BE SMALL. WINDS WILL BEGIN TO DIMINISH OVERNIGHT AS THE LOW PROGRESSES INTO NEVADA. COOLER AIR WILL MOVE THROUGH OUR REGION TODAY LEADING TO HIGHS JUST IN THE UPPER 50S TO MID 60S IN MOST SPOTS. AGREE WITH THE PREVIOUS SHIFT THAT WE MAY SEE A STRAY SHOWER OR TWO OVER HIGHER ELEVATION SPOTS THIS AFTERNOON AND EVENING. CURRENT FORECAST PACKAGE APPEARS TO BE ON TRACK SO NO MAJOR CHANGES PLANNED. .PREVIOUS DISCUSSION...EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWS AN UPPER TROUGH OVER THE PAC NW DIGGING SOUTH INTO NORTHERN CALIFORNIA. AS THIS TROUGH CONTINUES TO DIG FROM NORTH TO SOUTH THROUGH CALIFORNIA TODAY...IT WILL PRODUCE COOL AND LOCALLY BLUSTERY CONDITIONS ACROSS OUR REGION...AS WELL AS A SLIGHT CHANCE OF AFTERNOON AND EVENING SHOWERS. WEST TO NORTHWEST WINDS HAVE ALREADY INCREASED ALONG THE COAST AND LOCALLY IN THE HILLS EARLY THIS MORNING. WIND GUSTS ARE CURRENTLY IN EXCESS OF 30 MPH AT BOTH THE SAN FRANCISCO AND HALF MOON BAY AIRPORTS...AS WELL AS SOME SPOTS IN THE NORTH BAY HILLS. WINDS WILL REMAIN STRONG AND GUSTY NEAR THE COAST THROUGH THE DAY AND WILL PEAK LATE THIS AFTERNOON BEFORE GRADUALLY TAPERING OFF THIS EVENING. BY LATE AFTERNOON WINDS WILL PROBABLY MEET WIND ADVISORY CRITERIA AT A FEW OF THE WINDIEST SPOTS ALONG AND NEAR THE COAST SUCH AS POINT REYES AND SAN FRANCISCO AIRPORT WHERE GUSTS UP TO 45 MPH ARE POSSIBLE. HOWEVER...DO NOT EXPECT WIDESPREAD STRONG WINDS WHICH WOULD NECESSITATE A WIND ADVISORY. THIS SYSTEM DOES NOT HAVE A LOT OF MOISTURE TO WORK WITH...BUT BOTH THE NAM AND GFS FORECAST SCATTERED LIGHT PRECIP ACROSS OUR HILLS LATER TODAY...MAINLY FROM THE SOUTHERN DIABLO RANGE SOUTH INTO SAN BENITO COUNTY...AND ALSO ISOLATED SPOTS IN THE NORTH BAY HILLS AND IN THE SANTA LUCIAS. HAVE THEREFORE ADDED SLIGHT SHOWER CHANCES TO SOME OF OUR HIGHER ELEVATION AREAS THIS AFTERNOON AND EARLY EVENING. THE CORE OF THE UPPER TROUGH WILL SHIFT TO THE EAST OVER THE GREAT BASIN BY TOMORROW WHICH WILL SHOULD DIMINISH SHOWER CHANCES IN OUR AREA. WINDS SHOULD NOT BE A SIGNIFICANT FACTOR AFTER TODAY. THE UPPER TROUGH IS FORECAST TO SHEAR APART BY LATE WEDNESDAY WITH THE BULK OF THE ENERGY MOVING QUICKLY OFF TO THE EAST AND THE REST SINKING SOUTH. THIS WILL ALLOW FOR SLIGHT WARMING ON WEDNESDAY. A GRADUAL WARMING TREND WILL THEN CONTINUE INTO THE LATTER HALF OF THE WORK WEEK AS AN UPPER RIDGE DEVELOPS NEAR THE WEST COAST. BY THE END OF THE WEEK TEMPERATURES WILL BE SLIGHTLY WARMER THAN NORMAL IN MOST AREAS...SOMETHING THAT IS EXPECTED TO CONTINUE INTO THE UPCOMING WEEKEND...ALONG WITH DRY CONDITIONS. AS RECENTLY AS YESTERDAY THE GFS HAD INDICATED THE POSSIBILITY OF WET WEATHER RETURNING BY LATE IN THE UPCOMING WEEKEND OR EARLY NEXT WEEK. BUT THE PAST FEW RUNS OF THE GFS MAINTAIN DRY WEATHER...WHICH AGREES WITH THE ECMWF. && .AVIATION...AS OF 04:31 AM PDT MONDAY...DIGGING UPPER LOW AND SOLID COLD AIR ADVECTION HAS REALLY RAMPED UP THE WINDS ACROSS THE REGION. THIS WILL BE THE MAIN CONCERN THROUGH MUCH OF THE TAF PERIOD. LESS OF A CONCERN...BUT STILL A POSSIBILITY ARE SOME AFTERNOON CU/POP UP SHOWERS. BEST CHC FOR ANY PRECIP REMAINS EAST OF THE REGION...BUT WILL CARRY A TEMPO SHRA FOR KLVK. OTHERWISE...VFR CONDITIONS. VICINITY OF KSFO....GUSTY WNW WINDS WILL CONTINUE TO EASE THROUGH EARLY THIS MORNING THEN INCREASE AGAIN THIS AFTERNOON. AN AIRPORT WEATHER WARNING WILL LIKELY BE NEEDED THIS AFTERNOON FOR GUSTS OVER 35 KT. KSFO BRIDGE APPROACH...SIMILAR TO KSFO BUT WINDS WILL GUST TO AROUND 30 KT. MONTEREY BAY AREA TERMINALS...A PASSING CIG OR TWO POSSIBLE THIS MORNING...ESPECIALLY KMRY. OTHERWISE...GUSTY AND VFR THIS AFTERNOON. && .MARINE...AS OF 04:31 AM PDT MONDAY...A DRY COLD FRONT IS MOVING THROUGH THE WATERS WITH GALE WARNINGS IN EFFECT MONDAY INTO TUESDAY FOR STRONG NORTHERLY WINDS. LIGHTER WIND AND SEAS ARE THEN FORECAST FOR MID TO LATE WEEK. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...MRY BAY SCA...PIGEON PT TO PT PINOS 0-10 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM GLW...PT ARENA TO PT REYES 0-10 NM GLW...PT ARENA TO PIGEON PT 10-60 NM GLW...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM SCA...PT REYES TO PIGEON PT 0-10 NM SCA...ROUGH BAR ADVISORY FOR SF BAR GLW...SF BAY FROM 1 PM && $$ PUBLIC FORECAST: BELL/DYKEMA AVIATION: MM MARINE: R_WALBRUN VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
Area Forecast Discussion...UPDATED National Weather Service Reno NV 619 AM PDT MON MAR 28 2016 .UPDATE... Band of moderate to occasionally heavy snow continues along and north of the I-80 corridor with the southern edge of the band sliding ever so slowly south toward Carson City-Dayton. Snow amounts have been in the 2 to 5 inch range thus far in the heavier snow bands with gusty north winds resulting in localized blowing and drifting snow. Latest finer scale HRRR model run indicates only a very slow drift south and east during the morning hours and then accelerating southward around 18-20z. There may be occasionalletups at KTRK-KRNO-KLOL-KCXP, but given the stationary nature of this system, CIGS/VSBY will remain restricted with MVFR/periods of IFR continuing through 18z. && .PREVIOUS DISCUSSION... /Issued 337 AM PDT MON MAR 28 2016/ UPDATE... The band continues to develop near and north of I-80 at this hour. Latest models keep the band in this vicinity through 8 AM before it slowly shifts south. Updating to keep most snow accumulation near and north of I-80 and reducing accumulations near and south of Highway 50. Also cancelling the advisory for southern Lyon County as the band will not make it there until late morning. By then, solar heating will be enough to preclude any road accumulation. Wallmann SYNOPSIS... A strong cold front will continue moving through the Sierra and Western Nevada this morning. Snow showers will occur behind the front today with the heaviest band expected along I-80 this morning. The upper low will continue to influence area weather into Wednesday as it slowly pulls east with scattered showers and cold temperatures. Mild and dry weather returns for late week. PREVIOUS DISCUSSION... /Issued 238 AM PDT MON MAR 28 2016/ SYNOPSIS... A strong cold front will continue moving through the Sierra and Western Nevada this morning. Snow showers will occur behind the front today with the heaviest band expected along I-80 this morning. The upper low will continue to influence area weather into Wednesday as it slowly pulls east with scattered showers and cold temperatures. Mild and dry weather returns for late week. SHORT TERM... The snow event is getting underway as I write this. The surface cold front is now along a line from Portola to Palomino Valley and then almost to Highway 50 in Churchill County. Showers have developed west of the crest and are moving east along the boundary. Currently, temps are mild from I-80 southward and around 40-45 degrees, but are in the 30s behind the front. With precip now moving in along I-80, areas below 5000 feet will start as rain, but expect it to change to snow north of Highway 50 by 6 AM. As for the band, the NAM/GFS/HRRR are hitting the I-80 corridor the hardest. The NAM actually shows close to 1" of water in the Reno/Sparks North Valleys. This is likely overdone, but 1/2" seems plausible. With the cold air coming in, this will mostly be snow and 3-6" of snow seems likely along the I-80 corridor above 4500 feet. Lighter amounts farther south away from this main band. Roads will be slick this morning near I-80 and also into eastern Plumas County due to the snow. Be prepared for a longer than normal commute and the advisories will continue as is. One thing to note is that the band doesn`t make it to southern Lyon County until late morning. If this occurs, any snow that falls will melt on impact, especially on the roads due to the higher late March sun angle. As we move into the afternoon, the cold pool moves overhead and expect snow showers to continue across the area, but little accumulation due to solar heating. Any lake effect for Pyramid Lake looks less likely today as models now show the winds being more Northeast, and also 30+ kts at 700 mb. This is in addition to the diurnal minimum in LES during the afternoon. Still, plenty of showers will be around in the instability. The upper low then only slowly pulls away into Wednesday. A northeast flow will continue on the backside Tuesday and Wednesday. Showers look more likely Tuesday as the cold pool remains close enough. Wednesday the instability is weaker and more south of I-80 so just have a slight chance of showers there. Temperatures will slowly moderate from today`s much below average readings, but remain below normal into Wednesday. Wallmann LONG TERM...Thursday through Sunday... Only minor changes were made as the previous forecast thinking is on track. Temperatures will begin to warm Thursday although northeast flow aloft will persist for one more day and keep the warmup slow initially. This will be the poorest day for mixing as surface warming will not keep up with warming temperatures aloft, resulting in moderate inversions. Friday, we expect temperatures to jump 7-10 degrees with a better mixing profile. For the weekend, instability and weak shortwave may be sufficient for isolated showers (probably not much more) across far northeast CA and northwest NV. Given the northern track of this shortwave, showers in the Sierra are unlikely and we have removed the mention there. Otherwise, it is going to be an unseasonably mild weekend with highs in the upper 50s to around 60 Sierra valleys and mid 60s to low 70s western NV valleys. AVIATION... A cold front moving southward into western NV early this morning will continue to drop south and allow colder air to settle into the I-80/Hwy 50 corridors. Meanwhile, instability continues to increase as upper low drops into the region with band of rain and snow intensifying near and north of I-80. Some models are indicating some impressive bands of precipitation developing through 15z and right now, it appears that zone will be very close to where it is setting up currently which would have bigger impacts for KTRK-KRNO-KLOL. Temps and dewpoints are currently too warm for much accumulation below 5000 feet and this will likely remain the case outside of heavier bands of precipitation even though we do anticipate a changeover to all snow during the morning hours. So the key to getting accumulation on area runways will be location of most intense snow bands prior to 16z. Light accumulations are already occurring at KTRK and we will just have to monitor radar trends for KRNO-KLOL. The band is forecast to slide south into Mono-Mineral County this afternoon and evening with some light accumulations possible at KMMH near or after sundown. Right now, due to the timing of the band (later in the morning) at KTVL-KCXP-KNFL, accumulations look minimal. There could still be some brief slushy accumulations if snow showers become sufficiently heavy. But any accumulation will melt quickly once the snow showers pass. Otherwise, expect periods of IFR/MVFR CIGS/VSBY during snow showers with terrain obscurement, especially close to the Sierra. Hohmann && .REV Watches/Warnings/Advisories... NV...Winter Weather Advisory until 11 AM PDT this morning NVZ003-004. CA...None. && $$ For more information from the National Weather Service visit... http://weather.gov/reno
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NWS MELBOURNE FL
929 AM EDT MON MAR 28 2016 .DISCUSSION... A FRONTAL BOUNDARY IS APPROACHING THE I-4 CORRIDOR AND IS ACCOMPANIED BY ISOLATED TO SCATTERED SHOWERS. SHOWERS HAVE BEEN ASCD WITH THE SFC CONVERGENCE WITHIN THE FRONTAL ZONE AS WELL AS SOME INDUCED VERTICAL MOTION ASCD WITH A JET MAXIMA WHICH IS IN THE PROCESS OF DEPARTING THE AREA. THE MORNING SOUNDING FROM XMR SHOWS A MOIST AND RELATIVELY UNSTABLE AIRMASS IN PLACE OF THE SLOWLY APPROACHING FRONTAL BOUNDARY. THE MAIN STORM HAZARD WILL BE LOCALLY HEAVY RAIN...LIGHTNING AND SFC WIND GUSTS OF 40 TO 50 MPH IN STRONGER STORMS. COOLER H5 TEMPS (-11C) CAN PROMOTE SOME SMALL HAIL DEVELOPMENT AS WELL. THERE IS A CONSIDERABLE AMOUNT OF CLOUDINESS IN PLACE TO CHALLENGE THE SHORT TERM FORECAST THIS AFTERNOON. LTST HRRR GUID INDICATES THE FRONTAL BOUNDARY WL REMAIN A FOCUS FOR CONV DEVELOPMENT AS IT SLOWLY ADVANCES SWD ACROSS PORTIONS CENTRAL FL DURING THE COURSE OF THE AFTERNOON. THE CURRENT FORECAST FEATURING SCT SHOWERS AND EMBEDDED THUNDER REMAINS ON TRACK WITH THIS SETUP AND NO ADJUSTMENTS ARE ANTICIPATED. PREVIOUS DISC) PRE FRONTAL MOISTURE BAND WILL EXIST ACROSS THE AREA TODAY WITH THE HIGHEST VALUES OVER THE SOUTH. TEMPS ALOFT LOOK SUFFICIENTLY COOL (MINUS 11 TO 12 CELSIUS AT 500MB) TO SUPPORT DEEP CONVECTION. CONSIDERABLE DEBRIS CLOUDS WILL LIKELY LINGER BUT MAX TEMPS SHOULD STILL CLIMB INTO THE MID 80S. NO DISCRETE MID LEVEL IMPULSES WERE NOTED BUT PROXIMITY OF JET AXIS SHOULD PROVIDE AREAS OF DIVERGENCE ALOFT. NOT SURE IF THE EAST COAST SEA BREEZE CAN FORM THIS AFTERNOON WITH BOUNDARY LAYER WESTERLY FLOW STARTING OUT NEAR 15 KNOTS. A WEAKENING OF THE PRESSURE GRADIENT IS INDICATED LATE IN THE DAY AND THE HRRR IS SHOWING A SEA BREEZE CLOSE TO THE COAST... SO WILL HOLD ONTO A SLIGHT CHANCE FOR STRONG STORMS ESPECIALLY NEAR THE COAST. MOS POPS CAME IN NEAR 40 PERCENT AREAWIDE AND HAVE MADE LITTLE CHANGE TO THE PREVIOUS FORECAST...GOING WITH 30 PERCENT FAR NORTH...40 PERCENT CENTRAL AND 50 PERCENT SOUTH. EXPECT SLIGHT CHANCE POPS THROUGH LATE EVENING AS HIGH MOISTURE AND BOUNDARIES LINGER. MOS SHOWS FRONTAL TYPE FOG/LOW STRATUS LATE TONIGHT BUT WILL NOT INCLUDE FOG MENTION IN THE FORECAST AS VISIBILITY DOES NOT LOOK VERY LOW AT THIS TIME. && .AVIATION... EARLY IFR-MVFR CEILINGS IN SOME LOCATIONS WILL MIX OUT AND LIFT ABOVE IFR COVERAGE BY 15Z. SCATTERED SHOWERS/ISOLATED STORMS THIS AFTERNOON/EARLY EVENING SHOULD FAVOR COASTAL AND SOUTHERN TERMINALS ESPECIALLY FM KTIX SOUTH TO KSUA AND KOBE. && .MARINE... RECENT TIGHTENING OF THE PRESSURE GRADIENT AS WELL AS THE UPR WIND MAXIMA ASCD WITH DEPARTING JET FEATURE HAS BROUGHT SOUTHWEST WINDS UP TO 15 KNOTS. LOW PRESSURE NORTHEAST OF FLORIDA WILL LIFT OUT AND THE PRESSURE GRADIENT WILL DIMINISH THIS AFTERNOON. ISOLATED-SCATTERED OFFSHORE MOVING STORMS CAN BE EXPECTED IN THE AFTERNOON AND EARLY EVENING. A FEW COULD BE STRONG. WESTERLY WINDS TONIGHT WILL DIMINISH TO 10 KNOTS OR LESS AS WEAKENING FRONT APPROACHES FROM THE NORTH. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ JP/TES
AREA FORECAST DISCUSSION...UPDATED
NWS MELBOURNE FL
450 AM EDT MON MAR 28 2016 .DISCUSSION... TODAY-TONIGHT...THERE HAS BEEN LITTLE CHANGE IN THE OVERALL SCENARIO OF A FRONTAL BOUNDARY MOVING OFF THE EASTERN SEABOARD TODAY WITH SOUTHERN END SLOWING/WEAKENING WHILE SAGGING INTO NORTH FLORIDA. PRE FRONTAL MOISTURE BAND WILL EXIST ACROSS THE AREA TODAY WITH THE HIGHEST VALUES OVER THE SOUTH. TEMPS ALOFT LOOK SUFFICIENTLY COOL (MINUS 11 TO 12 CELSIUS AT 500MB) TO SUPPORT DEEP CONVECTION. CONSIDERABLE DEBRIS CLOUDS WILL LIKELY LINGER BUT MAX TEMPS SHOULD STILL CLIMB INTO THE MID 80S. NO DISCRETE MID LEVEL IMPULSES WERE NOTED BUT PROXIMITY OF JET AXIS SHOULD PROVIDE AREAS OF DIVERGENCE ALOFT. NOT SURE IF THE EAST COAST SEA BREEZE CAN FORM THIS AFTERNOON WITH BOUNDARY LAYER WESTERLY FLOW STARTING OUT NEAR 15 KNOTS. A WEAKENING OF THE PRESSURE GRADIENT IS INDICATED LATE IN THE DAY AND THE HRRR IS SHOWING A SEA BREEZE CLOSE TO THE COAST... SO WILL HOLD ONTO A SLIGHT CHANCE FOR STRONG STORMS ESPECIALLY NEAR THE COAST. MOS POPS CAME IN NEAR 40 PERCENT AREAWIDE AND HAVE MADE LITTLE CHANGE TO THE PREVIOUS FORECAST...GOING WITH 30 PERCENT FAR NORTH...40 PERCENT CENTRAL AND 50 PERCENT SOUTH. EXPECT SLIGHT CHANCE POPS THROUGH LATE EVENING AS HIGH MOISTURE AND BOUNDARIES LINGER. MOS SHOWS FRONTAL TYPE FOG/LOW STRATUS LATE TONIGHT BUT WILL NOT INCLUDE FOG MENTION IN THE FORECAST AS VISIBILITY DOES NOT LOOK VERY LOW AT THIS TIME. TUE-TUE NIGHT...DEEPENING STORM SYSTEM OVER THE CANADIAN MARITIMES WILL ABANDON THE SRN EXTENSION OF ITS FRONTAL TROF...FRONT EXPECTED TO GRIND TO A HALT OVER CENTRAL FL BY DAYBREAK AS IT PRESSES INTO THE REMNANTS OF THE ATLC RIDGE AXIS OVER THE FL STRAITS. POST FRONTAL RIDGE EMBEDDED WITHIN STRONG WRLY MID/UPR LVL FLOW WILL PUSH FROM THE MS VALLEY TO THE MID ATLC COAST. THIS WILL FORCE POST FRONTAL WINDS TO VEER STEADILY FROM NW TO N THRU THE DAY...THEN TO E/NE OVERNIGHT. PROXIMITY OF THE FRONTAL MOISTURE BAND WILL LEAD TO A WIDE PRECIP SPREAD ACRS THE CWA. POPS INCREASING FROM 20PCT OVER VOLUSIA/NRN LAKE TO 50PCT ALONG THE TREASURE COAST/LAKE-O REGION. STRONG/SVR WX POTENTIAL WILL BE ENHANCED BY MID LVL THERMAL TROF PRESSING INTO THE REGION THAT WILL PUSH H50 TEMPS INTO THE -13C/-15C RANGE WITH LAPSE RATES THRU THE H85-H50 LYR RUNNING BTWN 6.0-7.0C/KM...AND BY AN ACTIVE SRN JET BRANCH WITH H30-H20 WINDS RUNNING IN THE 70-90KT RANGE FOR MUCH OF THE PD. LIMITED COOL AIR ADVECTION AS THE FRONT STALL OVER THE CWA AND NRLY SFC/LOW LVL WINDS IN ITS WAKE TO VEER TO E/NE. MAX TEMPS GENERALLY IN THE U70S/L80S AREAWIDE...MIN TEMPS L/M60S INTERIOR...M/U60S ALONG THE COAST. WED-WED NIGHT...FRONTAL REMNANTS WILL MEANDER ACRS THE CENTRAL PENINSULA AS THE POST FRONTAL RIDGE RACES INTO THE ATLC. SOME POST FRONTAL SUBSIDENCE WILL LINGER ACRS THE CWA...BUT THE MOST TELLING WX FEATURE IS A SURPRISING AMT OF MID LVL DRY AIR THAT WILL WORK ITS WAY INTO THE REGION...PWAT VALUES LOWERING TO ARND 1.3" AREAWIDE. STRONG WX THREAT WILL LINGER AS COOL AIR ALOFT WILL BE SLOW TO MODIFY...H50 TEMPS HOLDING ARND -11C/-12C. HOWEVER...OVERALL COVERAGE WILL BE AOB 30PCT AS THE FRONTAL BNDRY SHOULD FULLY WASH OUT BY THEN...WHILE WINDS THRU THE H100-H70 LYR VEERING FROM E TO SE WOULD GENERATE A DIFFUSE SEA BREEZE BNDRY. ONSHORE COMPONENT WILL KEEP TEMPS AOA CLIMO...AFTN MAXES IN THE U70S/L80S ALONG THE COAST...L/M80S INLAND. OVERNIGHT MINS IN THE M60S INLAND...U60S/L70S ALONG THE COAST. THU-SUN...RIDGE AXIS OVER THE ATLC WILL CONTINUE A STEADY EWD RETREAT INTO THE WEEKEND AS THE NEXT SHORT WAVE TROF WORKS ITS WAY FROM THE NATION`S MIDSECTION TOWARD THE ERN SEABOARD. H100-H70 WINDS VEERING FROM SE TO W/SW THU THRU FRI...ALLOWING DEEPER MOISTURE TO GRADUALLY WORK ITS WAY INTO THE STATE AHEAD OF THE NEXT FRONTAL BOUNDARY. GFS/ECMWF IN GOOD AGREEMENT THRU FRI WRT WITH THE PROGRESS OF THE FRONTAL BNDRY BUT BEGIN TO DIVERGE INTO THE WEEKEND...THOUGH THE 28/00Z RUNS HAVE TRENDED TOWARD BETTER AGREEMENT. GFS INITIALLY MORE AGGESSIVE WITH THE FROPA...PUSHING IT S OF THE I-4 CORRIDOR ON SAT WHILE ECMWF HANGS IT UP OVER THE BIG BEND REGION. THE TWO COME BACK INTO SYNC BY 12Z SUN AS GFS STALLS THE FRONT BTWN THE I-4 CORRIDOR AND LAKE-O BY 00Z SUN...GIVING THE ECMWF TO CATCH UP. WHILE THE DEFERENCES ARE MINOR...WOULD PREFER TO KEEP POPS AOB 40PCT THRU THE EXTENDED FCST UNTIL TIMING ASPECTS LINE UP A LITTLE BETTER. TEMPS ALOFT DO SHOW A SLIGHT WARMING TREND...BUT REMAIN COOL ENOUGH (AOB -9C) TO KEEP AT LEAST A SLGT CHC OF TSRAS IN THE FCST EACH DAY. PREVAILING SRLY WIND COMPONENT THRU THE LATTER HALF OF THE WEEK WILL KEEP TEMPS AOA CLIMO. MAX TEMPS IN THE U70S/M80S...MIN TEMPS IN THE M/U60S. && .AVIATION...STILL A CHANCE FOR IFR-MVFR CEILINGS FROM ABOUT KMCO NORTH EARLY THIS MORNING. AREAS OF LIGHT RAIN HAVE OCCURRED THERE BUT A TIGHTENING OF THE PRESSURE GRADIENT WAS NOTED SO BOUNDARY LAYER WINDS SHOULD INHIBIT FOG. SCATTERED SHOWERS/ISOLATED STORMS THIS AFTERNOON/EARLY EVENING SHOULD FAVOR COASTAL TERMINALS ESPECIALLY KTIX SOUTH TO KSUA. && .MARINE... TODAY/TONIGHT...RECENT TIGHTENING OF THE PRESSURE GRADIENT ACROSS THE NORTH WAS NOTED AS LOW PRESSURE FORMED NEAR THE CAROLINA COAST. THIS HAS BROUGHT SOUTHWEST WINDS UP TO 15 KNOTS BUT THE LOW WILL LIFT OUT AND THE PRESSURE GRADIENT WILL DIMINISH THIS AFTERNOON. ISOLATED-SCATTERED OFFSHORE MOVING STORMS CAN BE EXPECTED IN THE AFTERNOON AND EARLY EVENING. A FEW COULD BE STRONG. WESTERLY WINDS TONIGHT WILL DIMINISH TO 10 KNOTS OR LESS AS WEAKENING FRONT APPROACHES FROM THE NORTH. TUE-TUE NIGHT...FRNTL TROF EXPECTED TO STALL S BTWN THE I-4 CORRIDOR AND LAKE-O AS THE POST FRONTAL RIDGE RACES OFF THE MID ATLC COAST. WINDS WILL RESPOND BY VEERING STEADILY THRU THE DAY...LIGHT TO GENTLE W/NW AT DAWN...BCMG N BY MIDDAY...BCMG NE BY SUNSET...BCMG GENTLE TO MODERATE E/NE OVERNIGHT. SEAS 2-3FT NEARSHORE AND 3-5FT OFFSHORE THRU THE DAY...BUILDING UP 3-4FT NEARSHORE AND 4-6FT OFFSHORE OVERNIGHT. CHC OF SHRAS/SLGT CHC TSRAS MVG OFFSHORE. WED-WED NIGHT...DETERIORATING CONDITIONS AS THE RIDGE AXIS PUSHES WELL INTO THE W ATLC. GENTLE TO MODERATE ERLY BREEZE THRU THE DAY...BCMG SE OVERNIGHT. SEAS 3-5FT NEARSHORE AND 4-6FT OFFSHORE THRU THE DAY...BCMG 4-6FT AREAWIDE OVERNIGHT. CHC SHRAS/SLGT CHC TSRA MVG ONSHORE. THU-THU NIGHT...CAUTIONARY TO ADVISORY CONDITIONS AS A NEW FRONTAL TROF PRESSES INTO THE DEEP SOUTH/NE GOMEX AND INTERACTS WITH THE NW FLANK OF THE RETREATING RIDGE. MODERATE TO FRESH SRLY BREEZE WILL PREVAIL...SEAS SOMEWHAT FETCH PROTECTED DUE TO THE SRLY WINDS BUT STILL ANTICIPATE 4-5FT SEAS NEARSHORE AND 5-6FT SEAS OFFSHORE. CHC SHRAS/SLGT CHC TSRAS. FRI-FRI NIGHT...WINDS CONTINUE TO SHIFT AS THE FRONTAL TROF PRESSES INTO THE NRN PENINSULA. MODERATE TO FRESH SRLY BREEZE AT DAYBREAK... BCMG A GENTLE TO MODERATE S/SW BREEZE BY SUNSET...THEN LIGHT TO GENTLE W/SW BREEZE OVERNIGHT. SEAS 4-6FT NEARSHORE AND 5-7FT OFFSHORE THRU THE DAY...BCMG 3-4FT NEARSHORE AND 4-5FT OFFSHORE. CHC SHRAS/SLGT CHC TSRAS. && .PRELIMINARY POINT TEMPS/POPS... DAB 83 64 77 65 / 30 10 20 10 MCO 86 67 82 64 / 40 20 30 10 MLB 84 68 79 69 / 40 20 40 20 VRB 85 68 81 69 / 50 20 40 20 LEE 85 66 83 63 / 40 10 20 10 SFB 85 66 80 63 / 40 10 30 10 ORL 85 68 82 64 / 40 20 30 10 FPR 86 68 81 69 / 50 20 50 20 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ SHORT TERM...LASCODY LONG TERM....BRAGAW
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
416 AM EDT MON MAR 28 2016 .DISCUSSION... TODAY-TONIGHT...THERE HAS BEEN LITTLE CHANGE IN THE OVERALL SCENARIO OF A FRONTAL BOUNDARY MOVING OFF THE EASTERN SEABOARD TODAY WITH SOUTHERN END SLOWING/WEAKENING WHILE SAGGING INTO NORTH FLORIDA. PRE FRONTAL MOISTURE BAND WILL EXIST ACROSS THE AREA TODAY WITH THE HIGHEST VALUES OVER THE SOUTH. TEMPS ALOFT LOOK SUFFICIENTLY COOL (MINUS 11 TO 12 CELSIUS AT 500MB) TO SUPPORT DEEP CONVECTION. CONSIDERABLE DEBRIS CLOUDS WILL LIKELY LINGER BUT MAX TEMPS SHOULD STILL CLIMB INTO THE MID 80S. NO DISCRETE MID LEVEL IMPULSES WERE NOTED BUT PROXIMITY OF JET AXIS SHOULD PROVIDE AREAS OF DIVERGENCE ALOFT. NOT SURE IF THE EAST COAST SEA BREEZE CAN FORM THIS AFTERNOON WITH BOUNDARY LAYER WESTERLY FLOW STARTING OUT NEAR 15 KNOTS. A WEAKENING OF THE PRESSURE GRADIENT IS INDICATED LATE IN THE DAY AND THE HRRR IS SHOWING A SEA BREEZE CLOSE TO THE COAST... SO WILL HOLD ONTO A SLIGHT CHANCE FOR STRONG STORMS ESPECIALLY NEAR THE COAST. MOS POPS CAME IN NEAR 40 PERCENT AREAWIDE AND HAVE MADE LITTLE CHANGE TO THE PREVIOUS FORECAST...GOING WITH 30 PERCENT FAR NORTH...40 PERCENT CENTRAL AND 50 PERCENT SOUTH. EXPECT SLIGHT CHANCE POPS THROUGH LATE EVENING AS HIGH MOISTURE AND BOUNDARIES LINGER. MOS SHOWS FRONTAL TYPE FOG/LOW STRATUS LATE TONIGHT BUT WILL NOT INCLUDE FOG MENTION IN THE FORECAST AS VISIBILITY DOES NOT LOOK VERY LOW AT THIS TIME. TUE-TUE NIGHT...DEEPENING STORM SYSTEM OVER THE CANADIAN MARITIMES WILL ABANDON THE SRN EXTENSION OF ITS FRONTAL TROF...FRONT EXPECTED TO GRIND TO A HALT OVER CENTRAL FL BY DAYBREAK AS IT PRESSES INTO THE REMNANTS OF THE ATLC RIDGE AXIS OVER THE FL STRAITS. POST FRONTAL RIDGE EMBEDDED WITHIN STRONG WRLY MID/UPR LVL FLOW WILL PUSH FROM THE MS VALLEY TO THE MID ATLC COAST. THIS WILL FORCE POST FRONTAL WINDS TO VEER STEADILY FROM NW TO N THRU THE DAY...THEN TO E/NE OVERNIGHT. PROXIMITY OF THE FRONTAL MOISTURE BAND WILL LEAD TO A WIDE PRECIP SPREAD ACRS THE CWA. POPS INCREASING FROM 20PCT OVER VOLUSIA/NRN LAKE TO 50PCT ALONG THE TREASURE COAST/LAKE-O REGION. STRONG/SVR WX POTENTIAL WILL BE ENHANCED BY MID LVL THERMAL TROF PRESSING INTO THE REGION THAT WILL PUSH H50 TEMPS INTO THE -13C/-15C RANGE WITH LAPSE RATES THRU THE H85-H50 LYR RUNNING BTWN 6.0-7.0C/KM...AND BY AN ACTIVE SRN JET BRANCH WITH H30-H20 WINDS RUNNING IN THE 70-90KT RANGE FOR MUCH OF THE PD. LIMITED COOL AIR ADVECTION AS THE FRONT STALL OVER THE CWA AND NRLY SFC/LOW LVL WINDS IN ITS WAKE TO VEER TO E/NE. MAX TEMPS GENERALLY IN THE U70S/L80S AREAWIDE...MIN TEMPS L/M60S INTERIOR...M/U60S ALONG THE COAST. WED-WED NIGHT...FRONTAL REMNANTS WILL MEANDER ACRS THE CENTRAL PENINSULA AS THE POST FRONTAL RIDGE RACES INTO THE ATLC. SOME POST FRONTAL SUBSIDENCE WILL LINGER ACRS THE CWA...BUT THE MOST TELLING WX FEATURE IS A SURPRISING AMT OF MID LVL DRY AIR THAT WILL WORK ITS WAY INTO THE REGION...PWAT VALUES LOWERING TO ARND 1.3" AREAWIDE. STRONG WX THREAT WILL LINGER AS COOL AIR ALOFT WILL BE SLOW TO MODIFY...H50 TEMPS HOLDING ARND -11C/-12C. HOWEVER...OVERALL COVERAGE WILL BE AOB 30PCT AS THE FRONTAL BNDRY SHOULD FULLY WASH OUT BY THEN...WHILE WINDS THRU THE H100-H70 LYR VEERING FROM E TO SE WOULD GENERATE A DIFFUSE SEA BREEZE BNDRY. ONSHORE COMPONENT WILL KEEP TEMPS AOA CLIMO...AFTN MAXES IN THE U70S/L80S ALONG THE COAST...L/M80S INLAND. OVERNIGHT MINS IN THE M60S INLAND...U60S/L70S ALONG THE COAST. THU-SUN... UPDATE TO FOLLOW. && .AVIATION...STILL A CHANCE FOR IFR-MVFR CEILINGS FROM ABOUT KMCO NORTH EARLY THIS MORNING. AREAS OF LIGHT RAIN HAVE OCCURRED THERE BUT A TIGHTENING OF THE PRESSURE GRADIENT WAS NOTED SO BOUNDARY LAYER WINDS SHOULD INHIBIT FOG. SCATTERED SHOWERS/ISOLATED STORMS THIS AFTERNOON/EARLY EVENING SHOULD FAVOR COASTAL TERMINALS ESPECIALLY KTIX SOUTH TO KSUA. && .MARINE... TODAY/TONIGHT...RECENT TIGHTENING OF THE PRESSURE GRADIENT ACROSS THE NORTH WAS NOTED AS LOW PRESSURE FORMED NEAR THE CAROLINA COAST. THIS HAS BROUGHT SOUTHWEST WINDS UP TO 15 KNOTS BUT THE LOW WILL LIFT OUT AND THE PRESSURE GRADIENT WILL DIMINISH THIS AFTERNOON. ISOLATED-SCATTERED OFFSHORE MOVING STORMS CAN BE EXPECTED IN THE AFTERNOON AND EARLY EVENING. A FEW COULD BE STRONG. WESTERLY WINDS TONIGHT WILL DIMINISH TO 10 KNOTS OR LESS AS WEAKENING FRONT APPROACHES FROM THE NORTH. TUE-TUE NIGHT...FRNTL TROF EXPECTED TO STALL S BTWN THE I-4 CORRIDOR AND LAKE-O AS THE POST FRONTAL RIDGE RACES OFF THE MID ATLC COAST. WINDS WILL RESPOND BY VEERING STEADILY THRU THE DAY...LIGHT TO GENTLE W/NW AT DAWN...BCMG N BY MIDDAY...BCMG NE BY SUNSET...BCMG GENTLE TO MODERATE E/NE OVERNIGHT. SEAS 2-3FT NEARSHORE AND 3-5FT OFFSHORE THRU THE DAY...BUILDING UP 3-4FT NEARSHORE AND 4-6FT OFFSHORE OVERNIGHT. CHC OF SHRAS/SLGT CHC TSRAS MVG OFFSHORE. WED-WED NIGHT...DETERIORATING CONDITIONS AS THE RIDGE AXIS PUSHES WELL INTO THE W ATLC. GENTLE TO MODERATE ERLY BREEZE THRU THE DAY...BCMG SE OVERNIGHT. SEAS 3-5FT NEARSHORE AND 4-6FT OFFSHORE THRU THE DAY...BCMG 4-6FT AREAWIDE OVERNIGHT. CHC SHRAS/SLGT CHC TSRA MVG ONSHORE. THU-THU NIGHT...CAUTIONARY TO ADVISORY CONDITIONS AS A NEW FRONTAL TROF PRESSES INTO THE DEEP SOUTH/NE GOMEX AND INTERACTS WITH THE NW FLANK OF THE RETREATING RIDGE. MODERATE TO FRESH SRLY BREEZE WILL PREVAIL...SEAS SOMEWHAT FETCH PROTECTED DUE TO THE SRLY WINDS BUT STILL ANTICIPATE 4-5FT SEAS NEARSHORE AND 5-6FT SEAS OFFSHORE. CHC SHRAS/SLGT CHC TSRAS. FRI-FRI NIGHT...WINDS CONTINUE TO SHIFT AS THE FRONTAL TROF PRESSES INTO THE NRN PENINSULA. MODERATE TO FRESH SRLY BREEZE AT DAYBREAK... BCMG A GENTLE TO MODERATE S/SW BREEZE BY SUNSET...THEN LIGHT TO GENTLE W/SW BREEZE OVERNIGHT. SEAS 4-6FT NEARSHORE AND 5-7FT OFFSHORE THRU THE DAY...BCMG 3-4FT NEARSHORE AND 4-5FT OFFSHORE. CHC SHRAS/SLGT CHC TSRAS. && .PRELIMINARY POINT TEMPS/POPS... DAB 83 64 77 65 / 30 10 20 10 MCO 86 67 82 64 / 40 20 30 10 MLB 84 68 79 69 / 40 20 40 20 VRB 85 68 81 69 / 50 20 40 20 LEE 85 66 83 63 / 40 10 20 10 SFB 85 66 80 63 / 40 10 30 10 ORL 85 68 82 64 / 40 20 30 10 FPR 86 68 81 69 / 50 20 50 20 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ SHORT TERM...LASCODY LONG TERM....BRAGAW
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
206 AM EDT MON MAR 28 2016 .SYNOPSIS... WEAK AREAS OF LOW PRESSURE WILL TRACK NORTHEAST ACROSS THE REGION THROUGH TONIGHT... RESULTING IN NUMEROUS TO WIDESPREAD SHOWERS THROUGH THE EARLY EVENING. A FEW THUNDERSTORMS ARE POSSIBLE. ANOTHER COLD FRONT WILL MOVE ACROSS THE REGION BY LATE MONDAY. HIGH PRESSURE WILL OVERSPREAD THE REGION TUESDAY AND WEDNESDAY. ANOTHER CHANCE FOR RAIN LATE WEEK. TEMPERATURES WARMING TO AT OR ABOVE NORMAL DURING NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... BACK EDGE OF THE STEADY RAIN SHIELD HAS CLEARED THE CSRA AND SHOULD MOVE THROUGH THE MIDLANDS FROM SOUTHWEST TO NORTHEAST DURING THE REMAINDER OF THE NIGHT AS THE MAIN SYNOPTIC AND MESOSCALE SUPPORT FOR THE RAIN SHIFTS QUICKLY AWAY FROM THE AREA TONIGHT. THERE WERE A FEW SPOTS THAT HAD SOME LOCALLY HEAVY RAIN IN EXCESS OF 2 INCHES...ESPECIALLY IN LEE AND SOUTHEASTERN RICHLAND COUNTIES...BUT THAT ACTIVITY HAS WEAKENED. ALL CURRENT AREAL FLOOD ADVISORIES WILL BE ALLOWED TO EXPIRE ON SCHEDULE OVER THE NEXT HOUR OR TWO. DESPITE THE STRONGEST SUPPORT COMING TO AN END...THERE IS STILL ENOUGH LOW LEVEL MOISTURE AND UPPER LEVEL JET ENERGY AND MID LEVEL CVA TO SUPPORT SCATTERED SHOWERS UNTIL THE EARLY MORNING HOURS. THE CHANCE OF SHOWERS SHOULD END BY DAWN AS DEEPER DRIER AIR MOVES IN. THERE ARE STILL SOME QUESTIONS ABOUT FOG THIS MORNING. THE MOS GUIDANCE FROM BOTH THE NAM AND GFS INDICATE LOW VSBYS FOR A PERIOD OF TIME BEFORE SUNRISE...BUT THE HRRR SHOWS ONLY PATCHES OF FOG. CONSIDERING THAT ALL AREAS DID RECEIVE SOME RAIN TODAY...I WILL HOLD ON TO THE FOG...BUT CONFIDENCE IS AVERAGE AT BEST. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/... UPPER LEVEL TROUGH MOVING EAST ACROSS THE OHIO VALLEY/GREAT LAKES REGION EARLY MONDAY WILL DRIVE A COLD FRONT TOWARD THE REGION MONDAY. WITH TROUGH MAINLY NORTH OF THE AREA...FRONTAL PASSAGE MAY BE DELAYED UNTIL LATE IN THE DAY OR EARLY EVENING. MOISTURE WILL BE LIMITED AND SHALLOW. SUBSIDENCE INVERSION DEVELOPS BY MIDDAY...GUIDANCE POPS VERY LOW SO REMOVED POPS. LITTLE IN THE WAY OF COLD ADVECTION DURING THE DAY AND DOWNSLOPE MORE LIKELY...SO WARM DAY EXPECTED WITH TEMPERATURES ABOVE NORMAL AROUND 80 DEGREES. COOL NIGHT MONDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE TENNESSEE/OHIO VALLEY REGION. GUIDANCE REASONABLE IN THE 40S. SEASONABLE TEMPERATURES/BUT COOL NIGHT EXPECTED TUESDAY AND WEDNESDAY AND FAIR WEATHER AS UPPER LEVEL RIDGE OVER THE MIDWEST BUILDS EAST. NORTHWEST FLOW ALOFT UNTIL LATER IN THE DAY WEDNESDAY AS RIDGE AXIS SHIFTS OVERHEAD AND THEN EAST. LOW-LEVEL MOISTURE INCREASE LATE WEDNESDAY FROM THE GULF COAST. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... ANOTHER FRONTAL SYSTEM AFFECTS THE AREA THURSDAY AND FRIDAY. ENSEMBLE POPS REMAIN HIGH. SOME POTENTIAL FOR STRONG THUNDERSTORMS THURSDAY WITH STRONG SOUTHWEST LOW LEVEL JET-MAX AND LARGE SCALE ASCENT...BUT DEGREE OF INSTABILITY UNCERTAIN. FRONT MAY LINGER THROUGH FRIDAY BUT CLEARING EXPECTED FOR THE WEEKEND. TEMPERATURES NEAR OR ABOVE NORMAL THROUGH THE PERIOD. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... RESTRICTIONS EXPECTED THROUGH THE FIRST HALF OF THE PERIOD WITH CONDITIONS RETURNING TO VFR AROUND 15Z. LOW PRESSURE OVER THE EASTERN COAST WILL CONTINUE TO DEVELOP OVERNIGHT AND LIFT NORTHEAST AWAY FROM THE REGION MONDAY. LIGHT RAIN AND DRIZZLE WILL LINGER OVER CENTRAL SC FOR THE NEXT SEVERAL HOURS...CLEARING ALL TAF SITES BY 09Z. VISIBILITIES WILL BE TEMPORARILY REDUCED AS SHOWERS MOVE THROUGH. CEILINGS ARE EXPECTED TO LOWER OVERNIGHT AFTER THE RAIN MOVES OUT. HOWEVER FOG IS LESS CERTAIN. SIGNIFICANT LOW LEVEL MOISTURE WILL FAVOR FOG ALTHOUGH DECENT MIXING MAY OCCUR DUE TO A 30 KT LLJ. IFR/LIFR CIGS WILL PERSIST THROUGH THE SUNRISE HOURS THEN BEGIN SLOWLY IMPROVING AS HIGH PRESSURE BUILDS IN. VFR CONDITIONS WILL RETURN AROUND 15Z WITH WESTERLY WINDS PREVAILING. WINDS WILL BE GUSTY DURING THE AFTERNOON...UP TO 20 KTS. THERE WILL BE A WIND SHIFT TO NW LATE IN THE TAF PERIOD AS THE HIGH PRESSURE CENTER PUSHES FURTHER EAST. EXTENDED AVIATION OUTLOOK...PRECIPITATION AND ASSOCIATED RESTRICTIONS WILL COME BACK INTO THE FORECAST THURSDAY AND FRIDAY AS THE NEXT FRONT CROSSES THE REGION. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
113 AM EDT MON MAR 28 2016 .SYNOPSIS... DEVELOPING OFFSHORE LOW PRESSURE WILL MOVE AWAY FROM THE REGION OVERNIGHT. A COLD FRONT WILL APPROACH THE AREA MONDAY...THEN WILL MOVE OFFSHORE MONDAY NIGHT. HIGH PRESSURE WILL BUILD IN FOR THE MIDDLE OF THE WEEK BEFORE A STORM SYSTEM AFFECTS THE AREA DURING THE LATTER HALF OF THE WEEK. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... THE RISK FOR ISOLATED SHOWERS WILL LINGER FOR A FEW MORE HOURS BEFORE THE MAIN MOISTURE AXIS SHIFTS OFFSHORE. LOW STRATUS CONTINUES TO FILL IN EARLY THIS MORNING. WATCHING FOR POSSIBLE STATUS BUILD DOWN AND POSSIBLE FOG. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... MONDAY...SURFACE LOW PRES WILL BE OFF THE SE NORTH CAROLINA COAST AROUND DAYBREAK...DEEPENING AND MOVING TO THE NE. LOW LEVEL FLOW VEERS MORE WESTERLY AND INDICATIONS THAT MID LVL NVA AND BUILDING SUBSIDENCE WILL KEEP ANY LINGERING SHOWERS VERY ISOLATED EARLY TO MID MORNING. THE MAIN COLD FRONT IS FORECAST TO HANG BACK DURING THE AFTERNOON AND IT WILL DESTABILIZE. HOWEVER PWATS CONTINUE TO STEADILY FALL BELOW 1 INCH AND WITH A SINKING W TO WSW FLOW IN THE BOUNDARY LAYER WE EXPECT DRY WEATHER AND WARM CONDITIONS FOR THE AFTERNOON HOURS GIVEN PERSISTENT MODEL TRENDS. WHILE WE CANNOT RULE OUT A VERY ISOLATED SHOWER OR TSTM NEAR AN INLAND LEE-SIDE SURFACE TROUGH...WE OPTED TO KEEP POPS SILENT. HIGH TEMPS SHOULD RISE TO THE LOWER 80S WITH A FEW MID 80S IF SUNSHINE BECOMES PREVALENT AFTER EARLY AFTERNOON. THE TIMING OF THE COLD FRONT MOVING THROUGH THE AREA MONDAY NIGHT IS A BIT SLOWER THAN PREVIOUS MODEL RUNS BUT OVERALL TEMP SCHEMES WERE LOOKING GOOD WITH LOWS WELL INLAND IN THE UPPER 40S WITH MID 50S CLOSE TO THE COAST. TUESDAY...COOLER SURFACE HIGH PRESSURE CENTERED OVER THE GREAT LAKES WILL BUILD INTO THE CAROLINAS WHILE AN UPPER RIDGE WILL BE MOVING OVER THE MISSISSIPPI VALLEY. NORTHEAST WINDS AT THE SURFACE COMBINED WITH NORTHWEST WINDS ALOFT WILL USHER IN COOLER TEMPERATURES TO OUR REGION. SUNSHINE IS ON TAP WITH HIGHS RANGING FROM AROUND 70 NEAR THE SANTEE COOPER LAKES OF SOUTH CAROLINA TO THE MID 70S ALONG AND SOUTH OF I-16. WEDNESDAY...SURFACE HIGH PRESSURE IS FORECAST TO SLIDE OFFSHORE OF THE MID ATLC COAST TURNING AFTERNOON WINDS ONSHORE. THE ATMOSPHERE STILL LOOKS DRY WITH PLENTY OF DEEP LAYERED RIDGING. THERE COULD BE AN INCREASE IN HIGH CLOUDS AND PERHAPS SOME COASTAL STRATCU LATE. HIGHS WILL WARM TO THE MID AND UPPER 70S. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE RIDGE AXIS THAT WAS OVER THE EASTERN THIRD OF THE U.S. WILL SHIFT OFFSHORE WEDNESDAY NIGHT WITH DRY WEATHER LIKELY TO HANG ON. SURFACE LOW PRESSURE WILL MOVE FROM THE GREAT LAKES REGION NORTHEASTWARD WHILE THE ACCOMPANYING FRONT STRETCHES SOUTHWARD INTO THE CENTRAL GULF OF MEXICO. AS THIS FRONT MOVES EASTWARD SHOWERS WILL DEVELOP ACROSS THE AREA ON THURSDAY. DEPENDING ON THE EXACT LOCATION OF THE FRONT AND HOW MUCH MOISTURE IT TAPS...PERIODS OF HEAVY RAIN AND STRONG THUNDERSTORMS COULD OCCUR THURSDAY INTO FRIDAY. MODELS DIFFER REGARDING THE TIMING OF THE FRONTAL PASSAGE...SO WENT WITH A BLEND THAT KEEPS SHOWERS ACROSS THE AREA FRIDAY NIGHT INTO SATURDAY. DRIER CONDITIONS ARE EXPECTED LATE SATURDAY OR SATURDAY NIGHT. && .AVIATION /04Z MONDAY THROUGH FRIDAY/... IFR CIGS WILL BECOME FURTHER ENTRENCHED AT THE TERMINALS THROUGH SUNRISE. THERE IS A RISK FOR CIGS DROPPING BELOW ALTERNATE MINIMUMS...ESPCLY AT KSAV. IN FACT...THERE IS ABOUT A 30 PERCENT CHANCE OF CIGS DROPPING TO AIRFIELD MINIMUMS AT KSAV...BUT WILL NOT INCLUDE CIGS THAT LOW ATTM. WILL CARRY PREVAILING IFR WITH TEMPO LIFR AT KSAV. CONFIDENCE ON FOG FORMATION IS RATHER LOW RIGHT NOW AS THERE ARE INDICATIONS THAT SOME SLIGHTLY DRIER AIR MAY SNEAK IN ABOUT THE BOUNDARY LAYER. THIS MAY LIMIT THE STATUS BUILD DOWN SOMEWHAT. WILL HAVE TO WATCH THIS CAREFULLY AND AMEND AS NEEDED. CIGS WILL SLOWLY LIFT TO VFR BY MID MORNING AND MAY EVEN SCATTER OUT FOR A TIME BEFORE FILLING BACK IN AS A CUMULUS FIELD DEVELOPS/THICKENS. A COLD FRONT WILL MOVE THROUGH THE TERMINALS TONIGHT...AROUND 03 AT KCHS AND AFTER 06Z AT KSAV. EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED THROUGH WEDNESDAY. THERE WILL BE AN INCREASING POTENTIAL FOR FLIGHT RESTRICTIONS LATE WEEK AS A FRONT APPROACHES THE REGION. && .MARINE... TONIGHT...WATCHING FOR POSSIBLE SMALL CRAFT ADVISORY CONDITIONS DEVELOPING OVER THE GEORGIA OFFSHORE WATERS OVER THE NEXT SEVERAL HOURS. BOTH THE RAP AND H3R SHOW A BRIEF PERIOD OF 20-25 KT WINDS DEVELOPING...ENDING SHORTLY AFTER SUNRISE. WILL HOLD OFF ON RAISING FLAGS...BUT TRENDS ARE BEING MONITORED. WSW FLOW EXPECTED TO PREVAIL ON MONDAY IN THE WAKE OF THE DEPARTING LOW AND AHEAD OF A COLD FRONT. STRONGER FLOW NEAR 15 KT WITH SOME HIGHER GUSTS ARE EXPECTED TO BE FURTHER OFF BEYOND 20 NM OF THE SOUTH CAROLINA COAST DURING THE DAY. OVERALL 10 TO 15 KT WITH SEAS 2 TO 3 FT NEAR SHORE AND 3-4 FT WELL OFFSHORE. THE COLD FRONT WILL MOVE THROUGH THE WATERS MONDAY NIGHT...ESPECIALLY AFTER MIDNIGHT WITH WINDS VEERING N AND NNE LATE. THE SURGING DOES NOT LOOK QUITE AS STRONG ON THE 12Z SUNDAY MODEL RUN BUT WE MAINTAINED INCREASES TO 15 TO 20 KT AND SEAS 3 TO 5 FT BY TUESDAY... HIGHER OFFSHORE WATERS. AT THIS TIME...CONDITIONS APPEAR TO BE JUST BELOW ADVISORY CRITERIA UNLESS SOME LOCALIZED PINCHING DEVELOPS. WEDNESDAY INTO THURSDAY...THE FLOW WILL GRADUALLY VEER FROM EAST TO SOUTHEAST AND EVENTUALLY SOUTH ON THURSDAY. DURING THIS TIME WIND SPEEDS WILL GRADUALLY INCREASE WITH NEAR SHORE SURGES ASSOCIATED WITH THE SEA BREEZE EACH DAY. CONDITIONS WILL DETERIORATE THURSDAY AS A COLD FRONT APPROACHES THE AREA AND SMALL CRAFT ADVISORY CONDITIONS FOR AT LEAST SEAS APPEAR LIKELY OVER AT LEAST OUTER GEORGIA WATERS AND PERHAPS IN PARTS OF THE NEAR SHORE SOUTH CAROLINA MARINE LEGS. && .EQUIPMENT... THERE WILL BE NO UPPER AIR FLIGHTS FROM KCHS /STATION 72208/ UNTIL FURTHER NOTICE. A CRITICAL COMPONENT OF THE UPPER AIR EQUIPMENT HAS FAILED. A PART IS ON ORDER...BUT IT IS UNKNOWN AT THIS TIME WHEN THE PART WILL ARRIVE. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ ST
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE, IL
304 AM CDT MON MAR 28 2016 .SHORT TERM... 304 AM CDT THROUGH TUESDAY... PRIMARY SHORT TERM CONCERN INVOLVES THE STRATUS DECK AND TIMING ITS DEPARTURE TODAY AND SECONDARILY, THE IMPACT THE CLOUDS WILL HAVE ON HIGH TEMPS TODAY. GOES IMAGERY EARLY THIS MORNING SHOWS EASTWARD PROGRESS OF THE BACK EDGE OF THE STRATUS SLOWING SINCE EARLY THIS EVENING, WHICH WOULD TEND TO SUGGEST STRATUS HANGING AROUND THROUGH AT LEAST THE MORNING HOURS EASTERN CWA AND LIKELY INTO THE AFTERNOON. SOME HOLES HAVE POPPED IN THE STRATUS DECK RECENTLY OVER WISCONSIN, WITH SOME ADDITIONAL HOLES PROBABLY OPENING UP WITH SOME WEAK BOUNDARY LAYER HEATING TODAY. EVEN SO, MORE CLOUDS SHOULD KEEP TEMPS A BIT COOLER THAN EARLIER GUIDANCE SUPPORTED AND THROW IN A LAKE BREEZE THIS AFTERNOON AND LOOK FOR EVEN COOLER TEMPS NEAR THE LAKE. BY LATE THIS AFTERNOON OR EARLY THIS EVENING SKIES SHOULD CLEAR AND SET THE STAGE FOR A SEASONABLY COOL NIGHT TONIGHT. TUESDAY LOOKS TO BE SUNNY WITH TYPICAL EARLY SPRING TEMPS, RANGING FROM 40S NEAR THE LAKE TO MID-UPPER 50S WELL INLAND. IZZI && .LONG TERM... 304 AM CDT TUESDAY NIGHT THROUGH MONDAY... FOCUS HEADING INTO MID-WEEK IS ON THE STRONG TROUGH CURRENTLY OVER THE PAC NW WHICH SHOULD AMPLIFY AND DIG FARTHER SOUTH INTO THE FOUR CORNERS REGION BY TUESDAY BEFORE EJECTING OUT INTO THE PLAINS STATES MIDWEEK. DEEPENING SURFACE CYCLONE WILL RESULT IN STRENGTHENING SOUTHERLY FLOW/WARM AIR ADVECTION TUESDAY NIGHT AND ESPECIALLY INTO WEDNESDAY. LATEST SUITE OF MODELS WOULD SUPPORT PRIMARY FOCUS FOR PRECIP IN THE WAA REGIME REMAINING MOSTLY TO THE NORTH OF OUR CWA. HIGHS BY WEDNESDAY SHOULD CLIMB INTO THE 60S WITH STRONG ENOUGH OF A GRADIENT TO PREVENT LAKE COOLING. SHOWER/T-STORM CHANCES WILL BEGIN TO RAMP UP WEDNESDAY NIGHT AS STRONG AND STRENGTHENING SYSTEM TRACKS NORTHEAST INTO THE UPPER GREAT LAKES REGION. GFS/ECMWF BOTH HAVE SFC LOW DEEPENING TO SUB- 990MB WED NIGHT WHICH SHOULD KEEP A HOWLING SOUTHERLY WIND AND UNSEASONABLY WARM LOW TEMPS AS MID TO PERHAPS UPPER 50 DEGREE DEWPOINTS ARE DRAWN NORTH INTO THE AREA. TIME OF DAY SHOULD GREATLY LIMIT THREAT OF SEVERE WEATHER THIS FAR EAST WED NIGHT, HOWEVER, GIVEN THE STRENGTH OF THE SYSTEM THUNDERSTORMS APPEAR TO BE A REASONABLE BET INTO THE NIGHT. STRONG COLD FRONT LOOKS TO MOVE THROUGH THURSDAY MORNING WITH STRONG WINDS USHERING IN COOLER TEMPS AND HERALDING AN END TO RAIN CHANCES BY AFTERNOON. TROUGH OVER THE CENTRAL/EASTERN CONUS SHOULD RESULT IN SOMEWHAT BELOW AVERAGE TEMPS BY FRIDAY AND PERHAPS INTO THE WEEKEND. VERY COLD AIR ALOFT WITH THE UPPER TROUGH COMBINED WITH THE HIGHER EARLY APRIL SUN ANGLE AND WEAK S/W ENERGY PIVOTING THROUGH THE TROUGH COULD BE ENOUGH TO SPARK SOME ISOLD TO WLDY SCTD SHOWERS FRIDAY, WITH PERHAPS SOME GRAUPEL OR WET SNOW FLAKES MIXED IN DEPENDING ON HOW COLD AIR ALOFT ENDS UP BEING. QUESTIONS DO ARISE HEADING INTO THE WEEKEND AS GFS/ECMWF ARE NOW BOTH BEGINNING TO STEP BACK FROM THE IDEA OF AN IMPRESSIVE LATE SEASON ARCTIC OUTBREAK FOR THE AREA. IN FACT, LATEST EURO WOULD EVEN SUPPORT ABOVE AVG TEMPS NOW FOR SUNDAY WITH A CLIPPER PASSING TO OUR NORTH. GIVEN THE RECENT VOLATILITY IN THE MODEL RUNS CONFIDENCE IS LOW IN THE FORECAST FOR NEXT WEEKEND, THOUGH IF RECENT TRENDS ARE A SIGN OF MODELS LOCKING ONTO A NEW SOLUTION THEN THE MUCH BELOW AVERAGE TEMPS THAT HAD PREVIOUSLY BEEN ADVERTISED IN THE MODELS NEXT WEEKEND WOULD NOT MATERIALIZE, AT LEAST NOT IN OUR AREA. STAY TUNED... IZZI && .AVIATION... FOR THE 06Z TAFS... MAIN CONCERNS/CHALLENGES THIS FORECAST PERIOD WILL BE WITH CONTINUED MVFR CEILINGS THROUGH MIDDAY AND THEN WITH A LAKE BREEZE SHIFT LATER THIS AFTERNOON. PRECIP HAS EXITED TO THE EAST EARLY THIS MORNING...WITH DRY CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE PERIOD. MVFR CEILINGS WILL LIKELY HOLD ON FOR MOST OF THE MORNING WITH A LARGE STRATUS SHIELD STILL OVER MUCH OF THE REGION. CEILINGS SHOULD REMAIN AROUND 1500FT WITH SOME POSSIBILITY FOR SOME SLIGHT LOWERING IN THE 1200-1500FT RANGE...BEFORE CEILINGS BEGIN TO LIFT BY MID TO LATE MORNING. NORTHWEST WIND IN PLACE WILL HOLD THIS MORNING INTO MOST OF TODAY BUT WITH A WIND SHIFT STILL EXPECTED LATER THIS AFTERNOON WITH A LAKE BREEZE. LOWER CONFIDENCE WITH EXACT TIMING BUT AT THIS POINT...THE 21/22Z TIMEFRAME STILL SEEMS REASONABLE. LOWER CONFIDENCE ALSO ON SPEEDS AND HAVE LEFT 08KT WITH THIS WIND SHIFT...BUT WILL NEED TO MONITOR FOR THE POSSIBILITY FOR SPEEDS TO REACH OR EXCEED 10KT. RODRIGUEZ && .MARINE... 213 AM CDT WITH LOW PRESSURE JUST TO THE EAST OF THE LAKE EARLY THIS MORNING...WINDS ARE IN THE NORTH NORTHWEST DIRECTION AND LOOK TO STAY THIS DIRECTION THROUGH MIDDAY. THIS LOW HAS BEEN DEEPENING THIS MORNING AND WILL CONTINUE TO DO SO HAS IT MOVES THROUGH THE GREAT LAKES REGION TODAY. AS THIS LOW HAS STRENGTHENED...SPEEDS HAVE INCREASED TO 30KT. THESE SPEEDS WILL LIKELY BE OBSERVED THROUGH MIDDAY WITH A DIMINISHING TREND EXPECTED THIS AFTERNOON WITH HIGH PRESSURE SHIFTING OVERHEAD. THIS DIMINISHING TREND IS EXPECTED THROUGH TONIGHT INTO TUESDAY...BUT WITH WINDS TURNING MORE SOUTHERLY OUT AHEAD OF A DEVELOPING SYSTEM OVER THE CENTRAL PLAINS. SOUTHERLY SPEEDS REALLY INCREASE ON WEDNESDAY WITH THE APPROACH OF THIS SYSTEM...WITH SPEEDS LIKELY BACK UP TO 30KT. GALES DO APPEAR POSSIBLE DURING THIS TIME...BUT HAVE LOWER CONFIDENCE WITH THIS POSSIBILITY. ALTHOUGH NOT CURRENTLY FORECASTING GALES FOR WEDNESDAY NIGHT INTO THURSDAY...STILL COULD BE A POSSIBILITY ON THE BACKSIDE OF THIS SYSTEM. RODRIGUEZ && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 3 PM MONDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 247 AM CDT MON MAR 28 2016 .SHORT TERM...(Today) ISSUED AT 247 AM CDT Mon Mar 28 2016 Deep cyclonic flow persists across central and southeast Illinois early this morning on the back side of yesterday`s storm system. However, the upper-level flow is expected to trend increasingly neutral today, while high pressure will begin to build in at the surface. This scenario is supportive of quiet weather across the area today. The main fly in the ointment is the extent of low cloud cover today, and its potential impact on temperatures. Most of the area should start the day cloudy in the cyclonic flow and associated wrap-around moisture. A weak low-level trof sinking toward the area from the Great Lakes will likely have the back edge of the clouds push slightly westward early today as it passes through. However, by afternoon, in the wake of this feature, expect significant clearing to have taken place. Widespread highs in the 50s, much cooler than yesterday across much of the forecast area, look like a good bet. && .LONG TERM...(Tonight through Sunday) ISSUED AT 247 AM CDT Mon Mar 28 2016 Main concern for this part of the forecast period remains with rain chances around mid week, along with the potential for colder weather next weekend. In the shorter term, high pressure will be drifting through the Midwest tonight and Tuesday, with dry weather prevailing. Temperatures expected to rise into the 60s both Tuesday and Wednesday as a strong southerly flow sets up behind the departing high. Area of low pressure aloft, seen on water vapor imagery near Portland OR this morning, continues to be progged by the evening models to strengthen into a closed low as it sinks into western Utah by early Wednesday morning. GFS and ECMWF track this feature to near Minneapolis by Thursday morning, while the NAM significantly lags behind and was not considered in the forecast. Some variation in how fast the moisture surge will lead to some precipitation, with the GFS bringing showers into the western CWA in the morning, while the ECMWF and Canadian hold off until afternoon. These models do agree in more widespread showers and storms Wednesday night, and have increased rain chances to the categorical range (80%). GFS increases precipitable water values to around 1.2-1.3 inches by Wednesday evening, with some heavier showers possible. Nighttime timing not especially favorable for severe weather, with latest SPC Day3 outlook keeping the slight risk just to our west, although there will be a strong low level jet into our area (GFS forecast soundings showing 40 knot winds only about 600 feet off the surface). Most precipitation will be out of the area by late Thursday morning. Latest runs of the GFS and ECMWF models are keeping the core of the colder air north of the Great Lakes this weekend, with a short period of 850 mb temperatures of -5 to -7C Saturday morning in our area concurrent with a fast moving shortwave. Blended model guidance is locking onto this, and keeps most of the forecast area above freezing Saturday morning and Sunday morning. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1146 PM CDT Sun Mar 27 2016 The back edge of clearing has reached our far SW counties, with dry air expected to continue to push into Illinois over the next 6-10 hours. Clearing will be battling the lingering low level moisture and influence of cyclonic flow aloft over NE Illinois. The HRRR indicated MVFR clouds retrograding back toward PIA to SPI from eastern Illinois in the late morning and afternoon. The NAM and GFS both point toward clearing out all TAF sites by afternoon. have leaned toward keeping clouds in a little longer tomorrow for now. Clearing should eventually develop under the advancing surface high pressure later Monday afternoon. West-northwest winds will remain steady the rest of the night, with 10-15kt. Wind directions should veer to the NW during the morning, while maintaining 10-14kt through mid-afternoon. NW winds will weaken under the cool high pressure Monday night. && .ILX Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...BAK LONG TERM...Geelhart AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE, IL
1248 AM CDT MON MAR 28 2016 .SHORT TERM... 211 PM CDT THROUGH MONDAY... RAIN AND COOLER TEMPERATURES WILL BE THE MAIN FORECAST CHALLENGES IN THE NEAR TERM. AS OF 19Z...A COLD FRONT IS EVIDENT OFF OF KLOT RADAR AND AREA OBS...AND STRETCHES FROM NEAR ORD SOUTH- SOUTHWEST INTO FORD COUNTY. TEMPERATURES AHEAD OF THE FRONT HAVE WARMED INTO THE 60S WITH A FEW SITES IN THE FAR SOUTHEASTERN COUNTIES OF THE FORECAST AREA FLIRTING WITH THE 70 MARK. AS THE FRONT SWEEPS THROUGH...EXPECT TEMPERATURES TO FALL BACK INTO THE 40S AND FOR RAIN TO OVERSPREAD THE AREA. ANY INSTABILITY FOR THUNDERSTORMS SHOULD REMAIN JUST SOUTH AND EAST OF THE FORECAST AREA THIS AFTERNOON. SHOWERS SHOULD CLEAR MOST OF THE FORECAST AREA BY AROUND MIDNIGHT OR SO...THEN EXPECT CLOUDY CONDITIONS WITH BREEZY NORTHWEST WINDS TO BE IN PLACE OVERNIGHT. HIGH PRESSURE WILL BUILD IN FROM THE WEST ON MONDAY. ANY LINGERING STRATUS SHOULD CLEAR OUT DURING THE MORNING AND AFTERNOON HOURS AS ANTICYCLONIC FLOW BUILDS IN...AND WINDS SHOULD DROP TO 10 KT OR LESS AS THE GRADIENT RELAXES. THIS WILL ALLOW A LAKE BREEZE TO FORM DURING THE AFTERNOON. EXPECT HIGH TEMPS INTO THE LOW TO MID 50S ON MONDAY AWAY FROM THE LAKE FRONT...BUT ONCE WINDS TURN OFF OF LAKE MICHIGAN BEHIND THE LAKE BREEZE...TEMPERATURES WILL ONLY BE IN THE 40S. BMD && .LONG TERM... 258 PM CDT MONDAY NIGHT THROUGH SUNDAY... LOWERED LOWS MONDAY NIGHT AS HIGH PRESSURE SHOULD LEAD TO CLEAR SKIES AND WEAK WINDS. RADIATIONAL COOLING SHOULD ALLOW TEMPS TO FALL INTO THE MID TO LOWER 30S. THE HIGH CONTINUES EAST TUESDAY...AND TUESDAY LOOKS DRY WITH WINDS BECOMING SOUTHEAST. CLOUDS SLOWLY BUILD IN SO THINKING THE STRENGTHENING SPRING SUN SHOULD BE ABLE TO RAISE TEMPS TO AROUND 60 AWAY FROM THE LAKE. SOUTHEAST WINDS WILL RESULT IN HIGHS IN THE UPPER 40S ALONG THE LAKE. THE NEXT LOW APPROACHES TUESDAY NIGHT AND MODELS SLOW THE PROGRESSION OF RAIN. KEPT A DRY FORECAST TUESDAY NIGHT WITH A VERY SLIGHT CHANCE OF SHOWERS ALONG THE IL/WI STATE LINE. HAVE LOW CONFIDENCE IN SHOWER/THUNDERSTORM COVERAGE WEDNESDAY. LOWERED POPS INTO THE CHANCE RANGE AS SOUNDINGS FEATURE SHALLOW SATURATION. THE LOW/S WARM FRONT IS PROGGED TO LIFT NORTH THROUGH THE REGION WEDNESDAY WITH WEAK FORCING ALONG IT. THE VARIOUS GUIDANCE MODELS DO NOT FEATURE MUCH UPPER LEVEL SUPPORT AND CAPE APPEARS TO BE MOSTLY ELEVATED. HAVE LOW CONFIDENCE IN PRECIP AND THUNDER COVERAGE. HAVE HIGHER CONFIDENCE IN GUSTY SOUTH WINDS WEDNESDAY WITH GUSTS 30-35 MPH OR HIGHER PSBL. HAVE MUCH HIGHER CONFIDENCE IN SHOWERS AND POSSIBLY A FEW STORMS WEDNESDAY NIGHT AS THE LOW DEEPENS OVER THE LAKE AND ITS COLD FRONT SWEEPS THROUGH. THE EURO HOLDS ON TO PRECIP LONGER THURSDAY MORNING SO KEPT POPS IN THE CHANCE OR HIGHER RANGE ESPECIALLY SINCE THE UPPER LEVEL TROUGH AXIS ROTATES THROUGH. TEMPS COULD BE COOLER THAN FORECAST...BUT MATCHED HIGH TEMPS TO THE MORNING 925 MB TEMPS OF +10 TO +14 C. ADDITIONAL VORT STREAMERS ROTATE THROUGH THURSDAY NIGHT SO KEPT AT LEAST A SLIGHT CHANCE OF PRECIP. TEMPS WILL DROP INTO THE 30S AND COULD SEE A RAIN/SNOW MIX NORTHWEST OF I-55 THURSDAY NIGHT. CONTINUE TO HAVE A CHANCE OF PRECIP FRIDAY AS YET ANOTHER UPPER LEVEL TROUGH AXIS ROTATES THROUGH. COLD AIR ALSO PUNCHES DOWN WITH THE TROUGH LEADING TO HIGHS AROUND 50 FRIDAY. ANOTHER LOW PASSES OVER THE NORTHERN LAKES SATURDAY. THINKING PRECIP WILL STAY OVER THE LAKE LATE THIS WEEK AND TEMPS WILL BE AT OR BELOW NORMAL. LOWS IN THE 20S ARE POSSIBLE NEXT WEEKEND. JEE && .AVIATION... FOR THE 06Z TAFS... MAIN CONCERNS/CHALLENGES THIS FORECAST PERIOD WILL BE WITH CONTINUED MVFR CEILINGS THROUGH MIDDAY AND THEN WITH A LAKE BREEZE SHIFT LATER THIS AFTERNOON. PRECIP HAS EXITED TO THE EAST EARLY THIS MORNING...WITH DRY CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE PERIOD. MVFR CEILINGS WILL LIKELY HOLD ON FOR MOST OF THE MORNING WITH A LARGE STRATUS SHIELD STILL OVER MUCH OF THE REGION. CEILINGS SHOULD REMAIN AROUND 1500FT WITH SOME POSSIBILITY FOR SOME SLIGHT LOWERING IN THE 1200-1500FT RANGE...BEFORE CEILINGS BEGIN TO LIFT BY MID TO LATE MORNING. NORTHWEST WIND IN PLACE WILL HOLD THIS MORNING INTO MOST OF TODAY BUT WITH A WIND SHIFT STILL EXPECTED LATER THIS AFTERNOON WITH A LAKE BREEZE. LOWER CONFIDENCE WITH EXACT TIMING BUT AT THIS POINT...THE 21/22Z TIMEFRAME STILL SEEMS REASONABLE. LOWER CONFIDENCE ALSO ON SPEEDS AND HAVE LEFT 08KT WITH THIS WIND SHIFT...BUT WILL NEED TO MONITOR FOR THE POSSIBILITY FOR SPEEDS TO REACH OR EXCEED 10KT. RODRIGUEZ && .MARINE... 258 PM CDT HEADLINES...THINKING CONDITIONS HAZARDOUS TO SMALL CRAFT WILL TAKE A LITTLE LONGER TO FORM...SO WILL NOT START THE SMALL CRAFT ADVISORY UNTIL LATE THIS EVENING. ANOTHER SMALL CRAFT ADVISORY MAY BE NEEDED WEDNESDAY AND AGAIN THURSDAY DUE TO HIGH WINDS. WINDS WILL VARY ACROSS THE LAKE THROUGH THIS EVENING AS THE LOW LIFTS NORTHEAST AND DEEPENS. WINDS BECOME MORE UNIFORM OUT OF THE NORTH AND NORTHWEST TO 30 KT AFTER MIDNIGHT. WINDS DIMINISH AND BECOME NORTHEAST TO EAST TUESDAY MORNING AS HIGH PRESSURE SPREADS OVER THE REGION. WINDS CONTINUE TO VEER AS THE HIGH SHIFTS EAST WITH SOUTH WINDS TO 30 KT BY WEDNESDAY. THE NEXT LOW FORMS OVER THE PLAINS WEDNESDAY AND DEEPENS AS IT PASSES OVER THE LAKE THURSDAY. WINDS WILL VARY FROM SOUTHWEST SOUTH OF THE LOW TO NORTHEAST NORTH OF THE LAKE. MODELS ALSO DISAGREE ON HOW STRONG WINDS WILL BE SOUTH OF THE LOW THURSDAY. COULD SEE GUSTS HIGHER THAN FORECAST. WINDS COULD ALSO BE HIGHER OVER THE NORTHERN END OF THE LAKE BEHIND THE LOW THURSDAY NIGHT...AND GALES COULD OCCUR. HAVE LOW CONFIDENCE IN WIND SPEEDS WITH THE LOW. ANOTHER LOW IS PROGGED TO PASS OVER THE NORTHERN LAKES SATURDAY WITH ANOTHER CHANCE OF GALES. DESPITE DECENT MODEL AGREEMENT IN TIMING AND LOCATION...MODELS DIFFER ON THE STRENGTH OF THE LOW SO HAVE LOW CONFIDENCE IN GALES NEXT WEEKEND AT THIS TIME. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 3 PM MONDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1146 PM CDT SUN MAR 27 2016 .UPDATE... Issued at 905 PM CDT Sun Mar 27 2016 Showers are quickly departing into Indiana, as the cold front pulls farther away to the east. West-northwest winds are still gusting to 20 mph at times, especially east of I-55. Those gusts should diminish a bit after midnight, but sustained winds will remain in the 10-15 mph range. Drier air aloft will gradually erode the cloud cover in Illinois from west to east, starting later tonight. HRRR guidance shows clearing reaching I-55 by sunrise, with clearing in the remainder of the area expected Monday morning. The colder low temps in the mid 30s will be more likely in areas that see clearing west of I-55, with upper 30s to around 40 east of there. Updates this evening were mainly to the PoP and weather grids, along with hourly temp trends. Updated forecast info is already available. && .SHORT TERM...(Tonight) ISSUED AT 300 PM CDT Sun Mar 27 2016 Cold front making its way through Central Illinois this afternoon. For now, the majority of the associated precip is well behind the boundary and dominated with moderate to heavy rain. Some destabilization out ahead of the advancing boundary is expected to continue this afternoon mainly southeast of a line from Shelbyville to Paris...but the area of concern continues to shift east. The MUCAPES are confined to the southeast and continue to move that way as cool outflow from the rainfall to the NW moves across the surface. Discrete cells ahead of the boundary will remain possible through the afternoon until the cold front moves through. So far, the cap is holding with some cloud cover slowing the development of the few echoes on radar. As far as the forecast goes...have rain showers continuing past 00Z into the evening behind the boundary and up until 06z, diminishing from west to east. Keeping much of the clouds in place for the overnight as the cloud deck is still well defined on sat imagery well back into IA. Cooler air will drop the overnight lows into the 30s...with areas to the west getting colder where some clearing will allow for more efficient radiational cooling towards dawn... and around 40 in the east where the clouds will be more persistent. .LONG TERM...(Monday through Sunday) ISSUED AT 300 PM CDT Sun Mar 27 2016 High pressure will move across the area Monday and Tuesday with dry and pleasant spring-like weather. However, another weather system will develop in the plains and move toward the area mid week. With the high pressure well to the west, windy south winds will bring the return of moisture to the midwest ahead of the system. Models look in good agreement that pcpn will remain west of the CWA through Tue night, but then pcpn becomes likely Wed afternoon well ahead of the front, that will still be back west of the area. So, could be two areas of showers and thunderstorms during the day. One over our CWA and then another back west near the front. Any rate, will have a chance of pcpn for Wed and then likely for Wed night as the front moves through the area. Once the sfc system moves through, the 500mb low pressure area and associated trough will rotate through the area Thur through Fri, so chances of pcpn will remain over portions of the CWA through the rest of the week. Then expecting dry and cooler conditions for next weekend. Temps will get warmer ahead of the next system and then cool a bit before the next one. Then cooler temps, with lows below freezing possible next weekend. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1146 PM CDT Sun Mar 27 2016 The back edge of clearing has reached our far SW counties, with dry air expected to continue to push into Illinois over the next 6-10 hours. Clearing will be battling the lingering low level moisture and influence of cyclonic flow aloft over NE Illinois. The HRRR indicated MVFR clouds retrograding back toward PIA to SPI from eastern Illinois in the late morning and afternoon. The NAM and GFS both point toward clearing out all TAF sites by afternoon. have leaned toward keeping clouds in a little longer tomorrow for now. Clearing should eventually develop under the advancing surface high pressure later Monday afternoon. West-northwest winds will remain steady the rest of the night, with 10-15kt. Wind directions should veer to the NW during the morning, while maintaining 10-14kt through mid-afternoon. NW winds will weaken under the cool high pressure Monday night. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...Shimon SHORT TERM...HJS LONG TERM...Auten AVIATION...Shimon
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1003 PM CDT TUE MAR 29 2016 ...Update for changes to severe weather potential Wednesday... .UPDATE... Issued at 925 PM CDT TUE MAR 29 2016 Have been closely monitoring incoming model data this evening, and the 01Z RAP, 00Z NAM, and 00Z HRRRexp have been showing some interesting model trends. First off, the trend has been toward slightly higher dewpoints by early afternoon with low 60s dewpoints into eastern KS. Another trend has been for the dryline to be setting up a bit farther to the west. At 19Z, the HRRRexp has the dryline from Minneapolis to Washington while the RAP is along Highway 81 and the NAM another 20 miles west. All models indicate at least some modification/mixing of low level moisture immediately in advance of the approaching dryline with dewpoints in the upper 50s to around 60. Afternoon surface winds are showing a consistent trend to have a westerly component and be veered as the surface low passes through eastern Nebraska. However, some concern remains for localized backing of winds between 21Z and 03Z as a new surface low deepens in south central KS. These are early indications, but all point to a continued and increasing severe weather threat across eastern Kansas between about 4 PM and 10 PM (or possibly later if the dryline stalls). Supercells look to be the primary storm mode but if winds remain veered into the late afternoon and evening could see more of a straight line hodograph with storm splitting and interaction, possibly resulting in some upscale growth and mixed modes. The take-away right now, based again on very early indications, is that the severe potential certainly exists through late afternoon and the evening with large hail, damaging wind, and tornadoes all possible. If winds back ahead of the developing surface low in the evening and if dewpoints hold in the low 60s, then the tornado threat could increase markedly. && .SHORT TERM...(This Evening through Wednesday) Issued at 306 PM CDT TUE MAR 29 2016 Elongated upper low was centered over the Inter-mountain West with a secondary shortwave trough continuing to drop south out of Manitoba territory. At the sfc, strong pressure gradient across the state with the sfc low over southeast CO has contributed to gusty southeast winds this afternoon in the 15 to 25 mph sustained range. Lower dewpoint temps across far eastern and northeast Kansas in addition to highs reaching the 60s has resulted in very high fire danger conditions across east central and far northeast Kansas. For this evening, the winds will persist in strength as the sfc low deepens eastward with an upper vorticity maxima ejecting northeast towards the northern plains. Southerly winds sustain between 15 and 25 mph at the sfc with occasional gusts up to 35 mph as the low level jet increases. Initial wave of lift will bring scattered showers and thunderstorms to north central KS after midnight. Expect this activity to spread east over the CWA through the morning hours. This activity is not expected to be severe with the MU Cape values generally below 600 J/KG. In addition to the overcast skies, forecast soundings show much of the moisture in the lowest levels of the atmosphere coinciding with the best forcing, indicative of light drizzle during this time as well. How quickly this precip dissipates allowing skies to clear out is variable depending on the model, leading to some uncertainty to how the afternoon evolves. The WRF models and the GFS have been consistently faster to clear skies and the dry line towards the MO/KS border by late afternoon while the NAM, ECMWF, and SREF runs have been consistently slower, focusing the eastern half of the CWA in a more favorable area. These factors have lead to some uncertainty in fire danger conditions and severe convection developing in the late afternoon and evening hours. More details are mentioned in the next period. For highs on Wednesday, while depth of cloud cover and presence of precip is still uncertain, strong warm advection ahead of the dryline should help support temps reaching the lower 70s, possibly mid 70s over north central KS as the dryline passes. RH values therefore may quickly fall in north central areas to the lower 20 percent range in the late afternoon. Wind speeds at this time remain marginal at 15 to 20 mph with gusts around 25 mph so will not mention headlines at this point. However, very high fire danger is likely. Main concern this forecast period will be the threat for strong to severe thunderstorms Wednesday afternoon across portions of eastern KS. During the early afternoon a dry line will push eastward through the forecast area. This dry line will separate deep mixing from the deep low level moisture to the east. Soundings show that surface heating along with mid level cooling associated with the approaching trough will erode the cap in place. This will allow thunderstorms to form along the dry line during the late afternoon. If the surface heating remains limited due stratus east of the dry line then convective initiation may be difficult or delayed. The cape seems to vary between the models, but with a dew point in the upper 50s to near 60, and steep mid level lapse rates it should yield around 1000 to 1500 j/kg of MLcape if the stratus can manage to clear out. With the approaching mid level system deep layer shear will be on the order of 50 to 60 kts. The hodographs are mainly straight line with the exception of the NAM. The NAM shows some localized backed winds in the low levels and a strengthening low level jet, which causes 0-3 km SRH values to approach 400. In reality those values may be closer to 100 to 200. Storms if they develop will be moving at 50 mph to the northeast. All of these parameters will support supercell development with large hail and damaging wind as the main threats. Although given this environment some tornadoes will be possible as well. The 0-1 km and 0-3 km bulk shear values could support mesovortex circulations if cold pools were to congeal into any line segments. There is split model solutions on where the dry line will be when storms develop. The farthest west seems to be a line from Washington to Dickinson counties, while the farthest east would be Jefferson to Anderson counties. So quite some spread that leads to some uncertainty in this forecast. The earliest models develop convection appears to be around 4 pm, and given the storm motion should clear the forecast area by 7 pm. .LONG TERM...(Wednesday Night through Tuesday) Issued at 306 PM CDT TUE MAR 29 2016 Thursday morning the synoptic cold front slides through the forecast area. Frontogenesis should provide enough lift for scattered showers mainly across northern KS. Initially there may be some mid level dry air to overcome before precipitation can reach the ground. Another shortwave will track towards the area in the northwest flow, which should clip northeast KS Thursday morning. This wave will bring the chance for showers after the low levels become saturated. The pattern remains quiet heading into the extended as northwest flow aloft continues. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 630 PM CDT TUE MAR 29 2016 VFR conditions are likely through 06Z but moisture will surge north late tonight with MVFR ceilings building in first at MHK and later at TOP/FOE. Some uncertainty regarding exact timing of cigs arrival but appears likely to arrive prior to sunrise. MVFR is most likely cig height but small potential for IFR mainly at MHK between 11-15Z. Small chance for a shower or storm between 11Z-15Z as well. Cigs seem likely to scatter/lift by late morning or early afternoon with TS developing near TAF sites between 20Z-23Z. && .TOP Watches/Warnings/Advisories... NONE. && $$ UPDATE...Barjenbruch SHORT TERM...Bowen/Sanders LONG TERM...Sanders AVIATION...Barjenbruch
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1213 PM CDT MON MAR 28 2016 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 312 AM CDT MON MAR 28 2016 An upper level trough across the pacific northwest will dig southeast into NV and UT Tonight and amplify. A downstream upper level ridge will amplify across the the central and southern plains. A lee surface trough will deepen across eastern CO which will cause south-southeast winds across eastern KS to increase through the afternoon hours to 10 to 20 MPH with gusts of 15 to 30 MPH. The stronger surface winds will occur across north central KS. The southerly winds will help to warm high temperatures into the mid to upper 60s. Tonight...the low-level jet will increase across western OK and the western half of KS through the night. This will result in the transport of deeper moisture northward into western KS. The resulting isentropic lift will cause elevated showers and thunderstorms to late tonight across west central KS. A few of these showers and elevated thunderstorms may move into the far western counties towards sunrise. Most of the numerical models show the showers and elevated storms remaining west of the CWA. I placed a 15- 20 percent pop in the western counties late tonight, in case a few of these elevated storms reach the western counties. The model forecasts show only 100 to 400 j/kg of MUCAPE, so these elevated storms will not be strong or severe. southeast surface winds will keep overnight lows in the lower to mid 40s. .LONG TERM...(Tuesday through Sunday) Issued at 312 AM CDT MON MAR 28 2016 Will keep some small pops going through the day Tuesday as isentropic lift weakens but southwest flow aloft could bring any precip on east. High cloud should stay rather thick with strong south winds beginning to saturate the lower levels in central Kansas. Have lowered highs a bit with more cloud expectations. Will need to continue to watch wind speeds in the afternoon and night, but a more backed lower level profile suggests less concern than before. Am less convinced of precip development Tuesday night into early Wednesday with weak elevated mixed layer in place, but moistening does occur aloft under diffluent jet, and could yet get some sprinkles in the saturating lower levels. Concern for severe storms remains for Wednesday afternoon and night. Upper trough rotating out of the western low pushes into the Central Plains in the day and on east into the Mississippi Valley Wednesday night with 500mb height falls around 110 m during the day. Dryline will push through much of Kansas during the day, but differences remain on timing and how much destabilization can occur as winds remain stout from the south with mixed layer aloft for a persistent stratus scenario, though CAPE could exceed 1000 J/kg. Strong wind fields aloft with 500mb winds in the 50-70kt range will bring considerable shear potential, but again much in the specifics remain to be desired in the lower levels based on timing and mixing uncertainty. Passage of the upper wave should dry the column out enough to keep any thing more than a few sprinkles in check from any weak northern branch energy Thursday into Friday. Upper flow backs into the weekend with old surface ridge to the south keeping moisture return retarded. High temps should moderate from the 50s to the 60s during these periods. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon) Issued at 1210 PM CDT MON MAR 28 2016 VFR prevails at terminals with occasional gusty south winds backing to the southeast aft 22Z above 10 kts sustained. Winds weaken to near 5 kts overnight as high clouds increase from the west. MVFR stratus with the next system is possible in the 15Z to 18Z time frame, however too low in confidence to mention for this issuance. && .FIRE WEATHER... Issued at 309 AM CDT MON MAR 28 2016 Expect a very high fire danger across the CWA this afternoon. Some areas across the western half of the CWA may be near red flag conditions. As the lee surface trough across eastern CO deepens this afternoon the surface pressure gradient will increase across central KS causing south-southeast surface winds to increase to 15 to 20 MPH with some gusts up to 30 MPH. The RAP forecast soundings show deeper mixing up to 800mb across north central KS which would cause dewpoints to mix out into the upper teens and lower 20s causing minimum RHs to drop below 20 percent. Since the winds will be slightly backed to the south-southeast the RAP may be mixing the boundary layer too deep. At this time I`m leaning more towards a model blend in which several members show the boundary layer only mixing up to around 850mb which would keep afternoon dewpoints in the mid to upper 20s and result in minimum RHs in the 21-27 percent range. The stronger wind gusts probably will not occur until the late afternoon hours. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Gargan LONG TERM...65 AVIATION...Bowen FIRE WEATHER...Gargan
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
618 AM CDT MON MAR 28 2016 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 312 AM CDT MON MAR 28 2016 An upper level trough across the pacific northwest will dig southeast into NV and UT Tonight and amplify. A downstream upper level ridge will amplify across the the central and southern plains. A lee surface trough will deepen across eastern CO which will cause south-southeast winds across eastern KS to increase through the afternoon hours to 10 to 20 MPH with gusts of 15 to 30 MPH. The stronger surface winds will occur across north central KS. The southerly winds will help to warm high temperatures into the mid to upper 60s. Tonight...the low-level jet will increase across western OK and the western half of KS through the night. This will result in the transport of deeper moisture northward into western KS. The resulting isentropic lift will cause elevated showers and thunderstorms to late tonight across west central KS. A few of these showers and elevated thunderstorms may move into the far western counties towards sunrise. Most of the numerical models show the showers and elevated storms remaining west of the CWA. I placed a 15- 20 percent pop in the western counties late tonight, in case a few of these elevated storms reach the western counties. The model forecasts show only 100 to 400 j/kg of MUCAPE, so these elevated storms will not be strong or severe. southeast surface winds will keep overnight lows in the lower to mid 40s. .LONG TERM...(Tuesday through Sunday) Issued at 312 AM CDT MON MAR 28 2016 Will keep some small pops going through the day Tuesday as isentropic lift weakens but southwest flow aloft could bring any precip on east. High cloud should stay rather thick with strong south winds beginning to saturate the lower levels in central Kansas. Have lowered highs a bit with more cloud expectations. Will need to continue to watch wind speeds in the afternoon and night, but a more backed lower level profile suggests less concern than before. Am less convinced of precip development Tuesday night into early Wednesday with weak elevated mixed layer in place, but moistening does occur aloft under diffluent jet, and could yet get some sprinkles in the saturating lower levels. Concern for severe storms remains for Wednesday afternoon and night. Upper trough rotating out of the western low pushes into the Central Plains in the day and on east into the Mississippi Valley Wednesday night with 500mb height falls around 110 m during the day. Dryline will push through much of Kansas during the day, but differences remain on timing and how much destabilization can occur as winds remain stout from the south with mixed layer aloft for a persistent stratus scenario, though CAPE could exceed 1000 J/kg. Strong wind fields aloft with 500mb winds in the 50-70kt range will bring considerable shear potential, but again much in the specifics remain to be desired in the lower levels based on timing and mixing uncertainty. Passage of the upper wave should dry the column out enough to keep any thing more than a few sprinkles in check from any weak northern branch energy Thursday into Friday. Upper flow backs into the weekend with old surface ridge to the south keeping moisture return retarded. High temps should moderate from the 50s to the 60s during these periods. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday Morning) Issued at 616 AM CDT MON MAR 28 2016 VFR conditions are expected throughout the period. Southerly winds will strengthen later this morning, with sustained 10-15 knots and gusts near 20 knots. Winds will then decrease to 5-10 knots after 00z this evening. && .FIRE WEATHER... Issued at 309 AM CDT MON MAR 28 2016 Expect a very high fire danger across the CWA this afternoon. Some areas across the western half of the CWA may be near red flag conditions. As the lee surface trough across eastern CO deepens this afternoon the surface pressure gradient will increase across central KS causing south-southeast surface winds to increase to 15 to 20 MPH with some gusts up to 30 MPH. The RAP forecast soundings show deeper mixing up to 800mb across north central KS which would cause dewpoints to mix out into the upper teens and lower 20s causing minimum RHs to drop below 20 percent. Since the winds will be slightly backed to the south-southeast the RAP may be mixing the boundary layer too deep. At this time I`m leaning more towards a model blend in which several members show the boundary layer only mixing up to around 850mb which would keep afternoon dewpoints in the mid to upper 20s and result in minimum RHs in the 21-27 percent range. The stronger wind gusts probably will not occur until the late afternoon hours. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Gargan LONG TERM...65 AVIATION...Baerg FIRE WEATHER...Gargan
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
312 AM CDT MON MAR 28 2016 .SHORT TERM...(Today and Tonight) Issued at 312 AM CDT MON MAR 28 2016 An upper level trough across the pacific northwest will dig southeast into NV and UT Tonight and amplify. A downstream upper level ridge will amplify across the the central and southern plains. A lee surface trough will deepen across eastern CO which will cause south-southeast winds across eastern KS to increase through the afternoon hours to 10 to 20 MPH with gusts of 15 to 30 MPH. The stronger surface winds will occur across north central KS. The southerly winds will help to warm high temperatures into the mid to upper 60s. Tonight...the low-level jet will increase across western OK and the western half of KS through the night. This will result in the transport of deeper moisture northward into western KS. The resulting isentropic lift will cause elevated showers and thunderstorms to late tonight across west central KS. A few of these showers and elevated thunderstorms may move into the far western counties towards sunrise. Most of the numerical models show the showers and elevated storms remaining west of the CWA. I placed a 15- 20 percent pop in the western counties late tonight, in case a few of these elevated storms reach the western counties. The model forecasts show only 100 to 400 j/kg of MUCAPE, so these elevated storms will not be strong or severe. southeast surface winds will keep overnight lows in the lower to mid 40s. .LONG TERM...(Tuesday through Sunday) Issued at 312 AM CDT MON MAR 28 2016 Will keep some small pops going through the day Tuesday as isentropic lift weakens but southwest flow aloft could bring any precip on east. High cloud should stay rather thick with strong south winds beginning to saturate the lower levels in central Kansas. Have lowered highs a bit with more cloud expectations. Will need to continue to watch wind speeds in the afternoon and night, but a more backed lower level profile suggests less concern than before. Am less convinced of precip development Tuesday night into early Wednesday with weak elevated mixed layer in place, but moistening does occur aloft under diffluent jet, and could yet get some sprinkles in the saturating lower levels. Concern for severe storms remains for Wednesday afternoon and night. Upper trough rotating out of the western low pushes into the Central Plains in the day and on east into the Mississippi Valley Wednesday night with 500mb height falls around 110 m during the day. Dryline will push through much of Kansas during the day, but differences remain on timing and how much destabilization can occur as winds remain stout from the south with mixed layer aloft for a persistent stratus scenario, though CAPE could exceed 1000 J/kg. Strong wind fields aloft with 500mb winds in the 50-70kt range will bring considerable shear potential, but again much in the specifics remain to be desired in the lower levels based on timing and mixing uncertainty. Passage of the upper wave should dry the column out enough to keep any thing more than a few sprinkles in check from any weak northern branch energy Thursday into Friday. Upper flow backs into the weekend with old surface ridge to the south keeping moisture return retarded. High temps should moderate from the 50s to the 60s during these periods. && .AVIATION...(For the 06Z TAFS through 06Z Monday Night) Issued at 1138 PM CDT SUN MAR 27 2016 Surface ridge over the area this evening which will move east through the period allowing return flow to develop over the plains. 00 UTC TOP sounding was extremely dry. Two issues concerning the TAFs. First, debated adding some BR around sunrise. Although there may be shallow fog in low areas, decided against mentioning it at KTOP/KMHK due to the very dry airmass and the surface ridge already southeast of the area by morning. Seconding, as return flow develops Monday along with good mixing, expect gusty winds during the afternoon. && .FIRE WEATHER... Issued at 309 AM CDT MON MAR 28 2016 Expect a very high fire danger across the CWA this afternoon. Some areas across the western half of the CWA may be near red flag conditions. As the lee surface trough across eastern CO deepens this afternoon the surface pressure gradient will increase across central KS causing south-southeast surface winds to increase to 15 to 20 MPH with some gusts up to 30 MPH. The RAP forecast soundings show deeper mixing up to 800mb across north central KS which would cause dewpoints to mix out into the upper teens and lower 20s causing minimum RHs to drop below 20 percent. Since the winds will be slightly backed to the south-southeast the RAP may be mixing the boundary layer too deep. At this time I`m leaning more towards a model blend in which several members show the boundary layer only mixing up to around 850mb which would keep afternoon dewpoints in the mid to upper 20s and result in minimum RHs in the 21-27 percent range. The stronger wind gusts probably will not occur until the late afternoon hours. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Gargan LONG TERM...65 AVIATION...Johnson FIRE WEATHER...Gargan
AREA FORECAST DISCUSSION
NWS JACKSON KY
238 AM EDT MON MAR 28 2016 .UPDATE... ISSUED AT 238 AM EDT MON MAR 28 2016 UPDATED FORECAST TO REFLECT CLOUDY SKIES THROUGH THE DAY MONDAY AS WE HAVE AMPLE LOW CLOUDS UPSTREAM (MORE SO THAN LAST SATURDAY MORNING AND WE SAW HOW THAT ENDED UP BEING A VERY CLOUDY DAY). WITH THESE CHANGES WE ALSO UPDATED TO RAISE TEMPERATURES EARLY THIS MORNING, THEN HAVE THEM HOLD STEADY OR ONLY A 1 TO 3 TEMP RISE THROUGH THE DAY WITH THE CLOUDS LOCKED IN. FINALLY...ADDED SOME DRIZZLE AS WE ARE ALREADY SEEING SOME LIGHT RETURNS SHOWING UP ON UPSTREAM RADARS. REST OF THE CONVECTIVE LINE/COLD FRONT SHOULD MOVE ON OUT IN THE NEXT FEW HOURS...WITH THAT TRANSITION TO DRIZZLE. UPDATE ISSUED AT 1056 PM EDT SUN MAR 27 2016 CONTINUING TO MONITOR AREA OF SHOWERS AND THUNDERSTORMS MOVING ACROSS CENTRAL KY...MAKING THEIR WAY INTO OUR FAR NORTHERN CWA.AT THIS POINT...THE LINE HAS LOST MOST OF ITS FORMATION AND ANY CELLS SEEM TO BE ON A DIMINISHING TREND. NOT TO SAY WE MAY NOT SEE AN ISOLATED STRONG CELL MOVE INTO THE CWA THIS EVENING STILL...BUT CONDITIONS ARE CONTINUING TO LOOK MORE AND MORE UNFAVORABLE. DID ANOTHER UPDATE TO THE POP AND WEATHER GRIDS TO BETTER REFLECT THE ONGOING RADAR TRENDS...AND WHAT IS EXPECTED INTO THE OVERNIGHT BASED ON THESE TRENDS AND LATEST HI RES MODEL DATA. ALSO LOADED THE LATEST OBSERVATIONS FOR TEMPS...DEW POINTS...AND WINDS INTO THE NEAR TERM FORECAST GRIDS TO MAKE SURE THEY WERE ON PAR WITH ONGOING CONDITIONS. ALL CHANGES HAVE BEEN PUBLISHED AND SENT TO NDFD AND THE WEB. HWO SEEMS TO STILL BE IN DECENT SHAPE...THOUGH IF STORMS CONTINUE THEIR DIMINISHING TREND WE MAY NEED TO REMOVE SMALL HAIL WORDING. ZFP IS STILL VALID. UPDATE ISSUED AT 908 PM EDT SUN MAR 27 2016 MADE A FEW UPDATES TO THE POPS AND WEATHER TIMING FOR OUR CWA...BASED ON THE CURRENT RADAR TRENDS AND LATEST HI RES MODEL OUTPUT. OVERALL POPS ARE STILL VERY WELL ON TRACK FROM PREVIOUS FORECAST...HOWEVER A FEW LIGHT SHOWERS ARE STARTING TO POP UP AHEAD WELL AHEAD OF THE LINE IN THE CWA. AS SUCH...UPGRADED MUCH OF THE CWA TO SLIGHT CHANCE POPS FOR THE NEXT COUPLE OF HOURS...THEN BLENDED INTO ONGOING FORECAST FOR THE MAIN AREA OF SHOWERS AND THUNDERSTORMS MOVING INTO THE REGION. WEATHER GRIDS WERE UPDATED ACCORDINGLY. WILL CONTINUE TO MONITOR THE INCOMING PRECIPITATION IN CASE ANY FURTHER UPDATES ARE NEEDED. SHORT TERM GRIDS HAVE BEEN PUBLISHED AND SENT TO NDFD/WEB. A NEW ZONE FORECAST HAS BEEN SENT TO TAKE OUT EARLY EVENING WORDING...AS WELL AS CAPTURE THE UPDATED WEATHER GRIDS. ALSO SENT OUT A NEW HWO TO REMOVE AFTER 9PM WORDING. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 350 PM EDT SUN MAR 27 2016 19Z SFC ANALYSIS SHOWS A DEEPENING AREA OF LOW PRESSURE MOVING INTO THE NORTHWESTERN OHIO VALLEY WITH A SHARP COLD FRONT RACING EAST TOWARD THE MISSISSIPPI RIVER. THIS FRONT WILL LIKELY BE THE DRIVER OF STORMS DEVELOPING LATER THIS EVENING THROUGH WESTERN AND CENTRAL KENTUCKY. IN EASTERN KENTUCKY...WELL AHEAD THE BOUNDARY... WINDS ARE STARTING TO PICK UP FROM THE SOUTHWEST OVER THE CUMBERLAND VALLEY WHILE THICK CLOUDS COVER MUCH OF THE CWA. THE CLOUDS LIMITED THE TEMP RISE SOMEWHAT IN THE EAST WITH SOME MID TO UPPER 60S NOTED WHILE IN THE WEST AND NORTH READINGS REACHED INTO THE 70S THANKS TO THINNER CLOUDS. DEWPOINTS...MEANWHILE ARE RUNNING IN THE LOW TO MID 50S...CONTINUING THEIR CLIMB AS THE AIR MASS MOISTENS AHEAD OF THE INCOMING SYSTEM...AND ALSO ADDING TO THE BUILDING INSTABILITY AS OF MID AFTERNOON. THE MODELS ARE IN BETTER AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL DEPICT WEAK MID LEVEL ENERGY PASSING OFF TO THE SOUTHEAST OF KENTUCKY THIS EVENING WHILE A COMPACT SHORTWAVE TROUGH CUTS INTO THE OHIO VALLEY ON ITS WAY NORTHEAST TO THE EASTERN GREAT LAKES. THE GFS HAS COME AROUND TO THE OTHER MODELS WITH MUCH BETTER CLUSTERING NOTED COMPARED TO YESTERDAY. THE CORE OF THIS SYSTEM WILL JUST BRUSH NORTHERN PARTS OF KENTUCKY THIS EVENING AND EARLY OVERNIGHT AS THE TROUGH PASSES. EVEN SO...THIS WILL PROVIDE A DYNAMIC PUNCH TO ANY SENSIBLE WEATHER TONIGHT. GIVEN THE MODEL AGREEMENT HAVE FAVORED A GENERAL BLEND FOR WX DETAILS...WITH A SIGNIFICANT LEAN TOWARD THE HRRR AND NAM12 IN THE NEAR TERM. SENSIBLE WEATHER WILL SEE A LATE SPRING EVENING AS AN APPROACHING FRONT LIKELY BRINGS STORMS TO THE AREA...CROSSING FROM WEST TO EAST TOWARD...AND JUST AFTER...MIDNIGHT. DESPITE THE CLOUDS... MUCH OF THE WESTERN AND NORTHERN PARTS OF THE AREA IS MAXIMIZING ITS CAPE AND DESTABILIZING. HOWEVER...THE FRONT WILL LIKELY BE NEEDED TO ACTIVATE THIS POTENTIAL AND THAT WILL NOT ARRIVE UNTIL WELL AFTER SUNSET AND INTO FALLING INSTABILITY. WHEN THE FRONT DOES ARRIVE...EXPECT A LINE OF SHOWERS AND STORMS TO ACCOMPANY IT WITH GUSTY WINDS AND HAIL...DUE TO THE LOW FREEZING LEVELS...AS THE MAIN THREATS. WILL BRING THIS FRONT THROUGH IN THE GRIDS WITH CATEGORICAL POPS AND A QUICK DIMINISHMENT ON ITS BACKSIDE ALONG WITH AN END TO THE STORM THREAT POST FROPA. CAA FOLLOWS THROUGH DAWN AND THEN LOOK FOR LOW CLOUDS TO LINGER DURING THE DAY MONDAY DESPITE HIGH PRESSURE BUILDING IN FROM THE WEST. SOME LOW LEVEL MOISTURE WILL LINGER INTO MONDAY NIGHT...BUT TEMPERATURES SHOULD STILL BE ABLE TO FALL INTO THE MID AND UPPER 30S WITH SOME PATCHY FROST ANTICIPATED...ESPECIALLY FOR PLACES THAT CLEAR OUT EARLIER IN THE NIGHT AND FOR VALLEY LOCATIONS. USED THE SHORTBLEND GUIDANCE AS A STARTING POINT FOR THE T/TD/WIND GRIDS THROUGH THE NIGHT AND THE SUPERBLEND THEREAFTER. DID MAKE SOME ADJUSTMENTS TO THE LOWS AND HOURLY TEMPS TONIGHT AND MONDAY NIGHT TO ACCOUNT FOR MINOR TERRAIN DIFFERENCES IN A CAA PATTERN. AS FOR POPS...ENDED UP CLOSE TO THE WET MOS NUMBERS TONIGHT AND SIMILARLY LOW THEREAFTER. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 350 PM EDT SUN MAR 27 2016 PERIOD WILL BEGIN WITH A UPPER LEVEL RIDGE AXIS STRETCHING NORTH ACROSS THE CENTRAL US AND SURFACE HIGH PASSING THROUGH THE OHIO VALLEY AND GREAT LAKES REGIONS. THIS WILL BRING WARMER AND DRIER WEATHER FOR TUESDAY AND WEDNESDAY. HOWEVER MORNINGS WILL START OFF COOL WITH FROST BEING A POTENTIAL CONCERN...BUT WE MAKE UP FOR IT WITH HIGHS GETTING BACK INTO THE LOWER 70S BY WEDNESDAY. ON THE OTHER SIDE OF THIS PREVIOUSLY MENTIONED RIDGE AXIS WILL BE A AMPLIFIED CLOSED LOW ACROSS THE WESTERN CONUS. THIS CLOSED LOW WILL TRY TO MOVE EAST...AND WILL EVENTUALLY PHASE WITH THE NORTHERN STREAM AS IT DOES. WHILE THIS TAKES PLACE A SURFACE LOW WILL DEEPEN AND EJECT NORTH AND EAST INTO THE GREAT LAKES REGION BY THURSDAY. A TRAILING COLD FRONT WILL SWEEP ACROSS THE TENNESSEE AND OHIO VALLEY REGIONS THURSDAY. THIS WILL BRING A INCREASED CHANCE FOR SHOWERS AND THUNDERSTORMS BY THURSDAY INTO THURSDAY NIGHT. WHILE THERE ARE SOME TIMING DIFFERENCES AND PHASING DIFFERENCES OVERALL MODELS SEEM TO BE MATCHING UP WELL FOR THE LONG TERM PERIOD. BEHIND THIS SYSTEM WE GET CAUGHT IN CYCLONIC FLOW AND ADDITIONAL SHORT WAVE SPOKES RIDING AROUND A DEEPER LOW ACROSS CENTRAL CANADA. THIS WILL BRING SLIGHT CHANCE OF SHOWERS ESPECIALLY IN THE AFTERNOON ON FRIDAY AS LAPSE RATES STEEPEN. WE WILL SEE ANOTHER COLD FRONT DROP SOUTH TOWARD THE END OF THE LONG TERM PERIOD AND THIS WILL FURTHER ENFORCE THE COLD AIR ACROSS EASTERN KENTUCKY. RIGHT NOW THIS FRONT LOOKS MOISTURE STARVED...AND THE MODEL BLEND KEEPS IT DRY ON SUNDAY. THIS COLD FRONT WILL COMBINE WITH UPPER LEVEL WAVES TO KEEP THE END OF THE WEEK COOL WITH TEMPS TOPPING OUT INTO THE UPPER 50S SATURDAY AND BY SUNDAY SOME MAY STRUGGLE TO GET OUT OF THE UPPER 40S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 238 AM EDT MON MAR 28 2016 COLD FRONT WILL EXIT TO THE EAST IN THE NEXT FEW HOURS WITH LOW LEVEL MOISTURE ON THE INCREASE ACROSS THE AREA. THIS MOISTURE...COUPLED WITH NORTHWEST UPSLOPE WINDS WILL LEAD TO LOW CIGS DEVELOPING TOWARDS DAYBREAK. THIS WILL ALSO LEAD TO SOME DRIZZLE. CIGS COULD BORDER ON IFR EARLY THIS MORNING BEFORE GOING MORE MVFR BY MIDDAY. KEPT MVFR CIGS AROUND THROUGH THIS EVENING AS IT MAY BE HARD TO LOOSE THE CLOUD COVER TODAY. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...GREIF LONG TERM...DJ AVIATION...KAS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
721 PM EDT TUE MAR 29 2016 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 343 PM EDT TUE MAR 29 2016 12Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW AN UPR RDG BLDG INTO THE WRN GREAT LKS...WITH 00Z-12Z H5 HGT RISES UP TO 80M AT GRB AND APX...DOWNSTREAM OF POLAR BRANCH CLOSED LO OVER THE WRN CONUS. SFC HI PRES OVER LOWER MI AND VERY DRY LLVL AIR DEPICTED ON THE LOCAL 12Z RAOBS ARE RESULTING IN QUIET WX OVER THE CWA DESPITE INCRSG HI CLDS ASSOCIATED WITH WAA IN INCRSG SLY FLOW BTWN DEPARTING HI PRES TO THE SE AND FALLING MSLP IN THE WESTERN PLAINS AHEAD OF WRN TROF. DESPITE THE INCRSG HI CLD COVER...TEMPS HAVE RISEN WELL INTO THE 50S OVER PORTIONS OF THE W HALF...ESPECIALLY WHERE SLY FLOW IS DOWNSLOPING. SOME RA TO THE NE OF SFC WARM FNT IN THE CENTRAL PLAINS HAS MOVED AS FAR NE AS FAR SW MN THIS AFTN. MAIN FCST CONCERNS IN THE SHORT TERM ARE CLD TRENDS AND TIMING ARRIVAL OF RA AHEAD OF PLAINS SFC LO PRES/WARM FNT FCST TO APRCH FM THE SW. TNGT...ALTHOUGH THE EVNG WL BE PCPN FREE WITH LINGERING DRY LLVL AIR...INCRSG DEEP LYR QVECTOR CNVGC RELATED TO SHARPENING ISENTROPIC ASCENT/MSTR ADVECTION BEST SHOWN ON THE 290 AND 295K SFCS /ABOUT H8- 7/ AND UPR DVGC IN RRQ OF 120KT H3 JET MAX FCST NEAR JAMES BAY AT 12Z WED WL RESULT IN INCRSG POPS OVERNGT...ESPECIALLY OVER THE NW HALF OF THE CWA. MORE PERSISTENT LLVL DRY AIR OVER THE SE HALF CLOSER TO DEPARTING SFC HI PRES IN THE MID ATLANTIC STATES WL HOLD DOWN POPS IN THAT AREA. WITH THE THICKENING CLDS AND STEADY SSW WINDS...THE OVERNGT WL BE MUCH WARMER THAN EARLY THIS MRNG. WITH SFC TEMPS FCST TO HOLD WELL ABOVE 32...THERE WL BE NO FROZEN/FRZG PCPN. WED...PERIODS OF RA UNDER AXIS OF DEEPER MSTR ASSOCIATED WITH PERSISTENT DEEP LYR QVECTOR CNVGC/290-295K ISENSTROPIC ASCENT WL BE THE RULE. A SFC COLD FNT ASSOCIATED WITH A DIGGING SHRTWV IN THE NRN BRANCH FLOW IS FCST TO REACH THE NW CWA BY LATE IN THE DAY. SOME OF THE GUIDANCE...ESPECIALLY THE 12Z NAM AND 00Z ECWMF...SUGGESTS SOME MID LVL DRYING ASSOCIATED WITH THIS NRN BRANCH FLOW MAY RESULT IN DIMINISHING POPS OVER AT LEAST THE FAR NW LATE IN THE DAY. SO FCST WL RETAIN SOME LOWERING OF POPS IN THAT AREA TOWARD 00Z THU. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 433 PM EDT TUE MAR 29 2016 FOR THE NEXT 1 TO 2 WEEKS...SOME DEGREE OF RIDGING WILL LIKELY PERSIST OVER WRN N AMERICA...THOUGH THE MORE PERSISTENT POSITIVE ANOMALY CENTER SHOULD REMAIN IN WRN CANADA. PER GFS ENSEMBLES...THE RIDGE WILL REACH PEAK AMPLITUDE WED/THU WHEN 500MB HEIGHT ANOMALIES TOP OUT AT 3-3.5 STANDARD DEVIATIONS ABOVE CLIMATOLOGY IN NRN BRITISH COLUMBIA/ADJACENT YUKON. THIS WILL FORCE DEEP TROFFING INTO SE CANADA AND ADJACENT GREAT LAKES. MAX NEGATIVE HEIGHT ANOMALIES OF 3-3.5 STANDARD DEVIATIONS BLO CLIMATOLOGY WILL BE CENTERED OVER ONTARIO SAT. WHILE CORE OF A COLD ARCTIC AIR MASS FOR EARLY APR WILL PASS BY TO THE NE...850MB TEMPS FALLING TO 2.5 STANDARD DEVIATIONS BLO CLIMATOLOGY HERE INDICATE CONDITIONS WILL BE QUITE COLD FOR EARLY APR STANDARDS THIS WEEKEND. MODERATION WILL BE A LITTLE SLOWER THAN PREVIOUSLY EXPECTED EARLY NEXT WEEK AS ANOTHER SHORTWAVE HELPS TO MAINTAIN ERN TROFFING. THEREAFTER...EXPECT MODERATION BACK TOWARD MORE TYPICAL EARLY APR TEMPS DUE TO WEAKER WRN RIDGING. HOWEVER... TEMPS COULD FLUCTUATE QUITE A BIT THRU THE FOLLOWING WEEKEND AS MODELS SUGGEST WRN RIDGE MAY AMPLIFY AT TIMES...ALLOWING LINGERING COLD AIR IN CANADA TO DUMP S BRIEFLY BEHIND PASSING SHORTWAVES. AS FOR PCPN...EARLY IN THE FCST PERIOD...PCPN WILL REVOLVE AROUND EVOLUTION OF THE ENERGY CURRENTLY OVER THE SW CONUS. A SIGNIFICANT PIECE OF ENERGY WILL EJECT DOWNSTREAM INTO THE GREAT LAKES WHILE ADDITIONAL ENERGY DIVES S IN THE AMPLIFYING NRN STREAM. THIS WILL LEAD TO THE MAIN PCPN EVENT OF THIS FCST CYCLE...OCCURRING WED/THU. SHORTWAVE PASSING FRI WILL PRODUCE DIURNALLY ENHANCED SHSN. CLIPPER SYSTEM PASSING EARLY SAT WILL THEN HERALD THE ARRIVAL OF MUCH COLDER AIR FOR THE WEEKEND...ACCOMPANIED BY LATE SEASON LES AND DIURNALLY ENHANCED SHSN. AFTER THE WEEKEND...THERE IS GREATER THAN NORMAL UNCERTAINTY IN PROGRESSION OF SHORTWAVES AND POTENTIAL PCPN. CANADIAN ENSEMBLES AND RECENT GFS/ECMWF RUNS SUGGEST THE NEXT BEST POTENTIAL FOR PCPN WOULD OCCUR AROUND WED. BEGINNING WED NIGHT/THU...AS ENERGY LIFTS OUT ACROSS THE PLAINS INTO THE GREAT LAKES WED NIGHT/THU...DEGREE OF PHASING WITH NRN STREAM ENERGY DIVING S INTO THE PLAINS WILL DETERMINE TRACK/STRENGTH OF THE SFC LOW PRES TRACKING FROM THE CNTRL PLAINS INTO THE GREAT LAKES. PHASING IS FURTHER COMPLICATED BY ANOTHER SHORTWAVE DIVING SSE THRU MANITOBA. BASED ON YESTERDAYS AND TODAY GUIDANCE...IT LOOKS INCREASINGLY LESS LIKELY THAT A WELL DEVELOPED/WRAPPED UP WINTER STORM WITH A WELL-DEFINED DEFORMATION BAND OF HVY PCPN WILL EVOLVE FROM THIS COMPLEX OF SHORTWAVES...BUT THAT`S NOT TO SAY THAT SOME MDT TO PERHAPS LOCALLY HVY SNOW ACCUMULATIONS WON`T OCCUR SOMEWHERE OVER THE UPPER MISSISSIPPI VALLEY AND THE UPPER LAKES. MODEL GUIDANCE CONTINUES TO NARROW IN ON A SFC LOW TRACK FROM THE WRN PLAINS ENE ACROSS WI AND THRU THE STRAITS AREA...AND ALL AVBL 12Z MODELS NOW SHOW QUITE GOOD AGREEMENT ON PROGRESSION OF COLDER AIR INTO UPPER MI WED NIGHT/THU WITH THE EXCEPTION OF THE NAM WHICH IS CONSISTENTLY FARTHEST S WITH COLDER AIR AND CHANGE TO SNOW AT EACH TIME STEP LATE WED NIGHT THRU THU. IN EXCLUDING THE NAM...EXPECT RAIN TO MIX GRADUALLY WITH/CHANGE TO SNOW FROM NW TO SE WED NIGHT/THU...BEGINNING NW LATE WED EVENING AND NOT REACHING THE SE UNTIL MID TO LATE AFTN THU. WITH THE LACK OF A WELL DEVELOPED SYSTEM/DEFORMATION PCPN...HEAVIER PCPN WILL NOT EXTEND TOO FAR NW INTO THE COLDER AIR. THIS SHOULD RESULT IN A FAIRLY NARROW BAND OF MAX SNOW ACCUMULATION IN THE ADVY RANGE SOMEWHERE OVER THE NW HALF OF UPPER MI. PER 00Z AND 12Z MODEL GUIDANCE...IT APPEARS THE AREA ROUGHLY FROM WATERSMEET/IRON RIVER NE THRU MICHIGAMME/NEGAUNEE SHOULD BE THE APPROXIMATE ZONE OF HEAVIEST SNOWFALL. WITH VERY LITTLE CHANCE OF WARNING CRITERIA BEING REACHED...ESPECIALLY WITH THE HEAVIER SNOW LIKELY FALLING DURING THE DAY THU WHEN WEAK SOLAR INSOLATION WILL AID MELTING...WATCH HEADLINES ARE NOT WARRANTED. MAIN SYNOPTIC PCPN SHIELD WILL DEPART LATER THU/THU EVENING. AFOREMENTIONED SHORTWAVE IN MANITOBA WILL THEN SWING THRU NRN ONTARIO/UPPER LAKES ON FRI...PROVIDING SCT TO NMRS -SHSN THAT WILL LIKELY BE ENHANCED BY DIURNAL HEATING UNDER CHILLY 500MB TEMPS DROPPING INTO THE MID -30S C. STRONGER SHORTWAVE AND ARCTIC COLD FRONT PASS ACROSS THE AREA SAT MORNING...ACCOMPANIED BY SHSN. WITH 850MB TEMPS FALLING TO -14 TO -17C SAT...LOOKS LIKE A SPRING-TIME HYBRID TYPE OF LAKE EFFECT SCENARIO SETTING UP BEHIND SHORTWAVE AS DAYTIME HEATING DISRUPTS LES PROCESSES AND LEADS TO SCT-NMRS DIURNALLY DRIVEN VIGOROUS SHSN ACROSS THE ENTIRE AREA UNDER CYCLONIC FLOW AND COLD AIR ALOFT. -SHSN WOULD THEN TRANSITION BACK TO A MORE TYPICAL LES REGIME SAT NIGHT/SUN MORNING AS 850MB TEMPS FALL TOWARD -20C. WITH MODERATING TEMPS ALOFT AND LOSS OF CYCLONIC FLOW...MAY NOT SEE MUCH DIURNALLY DRIVEN SHSN ACTIVITY ON SUN AFTER LES PROCESSES GET DISRUPTED AGAIN BY DAYTIME HEATING. HEADING INTO MON/TUE...THE LAST DAY OR SO OF MEDIUM RANGE MODEL RUNS HAVE SUGGESTED A SHORTWAVE TRACKING SE INTO THE RETREATING ERN TROF. ASSOCIATED WAA/ISENTROPIC ASCENT WITH WEAK SFC WAVE TRACKING ALONG THE EDGE OF THE LATE SEASON ARCTIC AIR WOULD GENERATE A STREAK OF SN SOMEWHERE ACROSS THE UPPER MISSISSIPPI VALLEY AND GREAT LAKES REGION SUN NIGHT/MON. UTILIZED A CONSENSUS OF RECENT MODEL RUNS FOR POPS (MOSTLY SCHC) DUE TO THE LACK OF MODEL AGREEMENT AND LACK OF RUN-TO- RUN CONTINUITY. SHOULD SEE A DRY DAY ON TUE BEFORE A POTENTIAL MIXED PCPN EVENT WED. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 721 PM EDT TUE MAR 29 2016 LLVL DRY AIR WILL BRING VFR CONDITIONS TONIGHT UNDER THICKENING HIGHER CLOUDS. GUSTY S WINDS UNDER THE TIGHTENING PRES GRADIENT BTWN THE DEPARTING HI PRES AND DVLPG LO PRES IN THE PLAINS WL GIVE WAY TO SOME LLWS TNGT WITH INCRSG NEAR SFC STABILITY AT KSAW. AS THE SSW FLOW TAPS MOISTER AIR LATE TNGT/WED MRNG...EXPECT SOME -RA TO ARRIVE AND CIGS TO LOWER INTO MVFR IN THE MORNING...BEGINNING FIRST AT KIWD AND LAST AT KSAW. BY AFTERNOON...KIWD AND KCMX WILL BE LIFR AND KSAW WILL BE MVFR. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 343 PM EDT TUE MAR 29 2016 AS THE PRES GRADIENT TIGHTENS OVER THE UPPER LAKES TONIGHT BETWEEN DEPARTING HI PRES AND LO PRES DEVELOPING IN THE WESTERN PLAINS... EXPECT SSW WINDS UP TO 25 KTS INTO WED MORNING. ALTHOUGH THE WINDS WILL DIMINISH AS THEY SHIFT TO THE NNW FOLLOWING A COLD FRONTAL PASSAGE LATE WED AFTERNOON/EVENING...STRONGER NNE WINDS UP TO 30 KTS WILL BE THE RULE LATE WED NIGHT AND THU AS A LO PRES RIDES NE ALONG THE STALLED FRONT JUST TO THE S OF UPPER MI. NOT OUT OF THE QUESTION THERE COULD BE SOME GALES ESPECIALLY OVER THE E HALF ON THU. WINDS WILL DIMINISH AND SHIFT TO THE WNW FOLLOWING THE EXIT OF THIS LO TO THE NE AND THE ARRIVAL OF A WEAK HI PRES RIDGE ON FRI. EXPECT ANOTHER LO TO TRACK THRU THE UPPER LAKES ON FRI NIGHT...WITH A WIND SHIFT TO THE N LATE AT NIGHT AND SAT. WINDS COULD REACH AS HI AS 30 TO 35 KTS BEFORE DIMINISHING ON SUN WITH THE CLOSER APPROACH OF TRAILING HI PRES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...ROLFSON AVIATION...07 MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
419 PM EDT MON MAR 28 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 357 PM EDT MON MAR 28 2016 12Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW AN UPR TROF EXTENDING FM QUEBEC INTO THE GREAT LKS DOWNSTREAM OF A RDG IN THE PLAINS AND A DEEPENING TROF OVER WRN NAMERICA. SHRTWV/DEEP LO PRES ARE MOVING THRU SE CANADA. ALTHOUGH THE DEEP MSTR ASSOCIATED WITH THIS DISTURBANCE IS NOW E OF THE CWA...SOME SC LINGERS OVER THE ERN CWA IN THE THERMAL TROF /H85 TEMPS ARND -4C/ AND SLOWLY WEAKENING CYC NLY FLOW LEFT IN THE WAKE OF THE DEPARTING SFC LO. BUT MORE ACYC FLOW EXTENDING S FM HI CENTER OVER FAR NW ONTARIO/ARRIVAL OF DRIER LLVL AIR SHOWN ON THE 12Z INL AND YPL RAOBS AS WELL AS DAYTIME HEATING/MIXING HAS ERODED THE LO CLDS OVER THE W. THERE IS ANOTHER SHRTWV/AREA OF MID CLDS MOVING INTO WRN LK SUP...BUT LARGER SCALE QVECTOR DVGC/SUBSIDENCE IN THE WAKE OF THE DEPARTING STRONGER SHRTWV IS CAUSING THESE MID CLDS TO DIMINISH AS THE TRAILING DISTURBANCE SLIDES INTO THE UPR LKS. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON CLDS TRENDS/IMPACT ON TEMPS. TNGT...THE HI PRES IN NW ONTARIO IS PROGGED TO BUILD SLOWLY S UNDER CONFLUENT NW FLOW E OF UPR RDG IN THE PLAINS THAT IS FCST TO BUILD IN MN OVERNGT. EXPECT MID CLDS ASSOCIATED WITH APRCHG SHRTWV TO CONTINUE TO DSPT IN THE LARGER SCALE QVECTOR DVGC/SUBSIDENCE AHEAD OF THIS RDG. ALTHOUGH SOME OF THE MODELS INDICATE LO CLDS MAY PERSIST OR REFORM OVER THE ERN CWA IN THE NLY FLOW AHEAD OF THE APRCHING HI PRES...DRYING/CLRG TRENDS UPSTREAM HINT THE GUIDANCE SHOWING LESS IN THE WAY OF CLD COVER IS ON THE RIGHT TRACK. WITH PWAT FCST TO FALL TO NEAR 0.20 INCH AND LIGHT WINDS UNDER THE MOCLR SKIES...EXPECT LO TEMPS TO FALL INTO THE TEENS AT SOME OF THE COLDER INTERIOR LOCATIONS OVER THE W AND CENTRAL CWA. TUE...INCRSG SLY FLOW ON THE WRN FLANK OF HI PRES RETREATING TO THE E IS FCST TO LIFT H85 TEMPS TO ARND 2C IN THE AFTN. ALTHOUGH THERE MAY BE SOME HI CLDS SPILLING OVER UPR RDG AXIS SHIFTING OVER THE WRN GREAT LKS...A GOOD DEAL OF SUNSHINE SHOULD BOOST MAX TEMPS WELL INTO THE 50S/CLOSE TO 60 OVER THE FAR W WHERE THE STEADY SLY FLOW WL DOWNSLOPE. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 418 PM EDT MON MAR 28 2016 FOR THE NEXT 1 TO 2 WEEKS...SOME DEGREE OF RIDGING WILL LIKELY PERSIST OVER WRN N AMERICA...THOUGH WITH MORE OF A SPLIT FLOW AS ENERGY UNDERCUTS WHAT WILL PROBABLY BE THE MORE PERSISTENT POSITIVE ANOMALY CENTER IN WRN CANADA. PER GFS ENSEMBLES...THE RIDGE WILL REACH PEAK AMPLITUDE WED/THU WHEN 500MB HEIGHT ANOMALIES TOP OUT AT 3-3.5 STANDARD DEVIATIONS ABOVE CLIMATOLOGY IN NRN BRITISH COLUMBIA/ADJACENT YUKON. THIS WILL FORCE DEEP ERN TROFFING INTO SE CANADA AND ADJACENT GREAT LAKES. MAX NEGATIVE HEIGHT ANOMALIES OF 3- 3.5 STANDARD DEVIATIONS BLO CLIMATOLOGY WILL BE CENTERED OVER NRN ONTARIO SUN. MEDIUM RANGE MODEL TRENDS OVER THE LAST 2 DAYS HAVE BEEN FOR FASTER WEAKENING OF THE WRN RIDGE WHICH RESULTS IN THE CORE OF AN UNUSUALLY COLD ARCTIC AIR MASS FOR EARLY APR PASSING BY TO THE NE OF HERE. STILL...WEATHER WILL BE MUCH COLDER ACROSS UPPER MI THIS WEEKEND. QUICK MODERATION BACK TOWARD MORE TYPICAL EARLY APR TEMPS WILL THEN OCCUR NEXT WEEK DUE TO WEAKER WRN RIDGING. HOWEVER...TEMPS COULD BECOME QUITE VARIABLE DUE TO THE POTENTIAL FOR AT LEAST 2 SHORTWAVES/LOW PRES SYSTEMS TO TRACK ACROSS THE NRN CONUS TO THE S OF LINGERING COLD AIR ACROSS CANADA. AS FOR PCPN...MAIN PCPN EVENT DURING THIS FCST PERIOD WILL REVOLVE AROUND EVOLUTION OF THE ENERGY CURRENTLY DROPPING INTO THE SW CONUS. A SIGNIFICANT PIECE OF ENERGY WILL EJECT DOWNSTREAM INTO THE GREAT LAKES WHILE ADDITIONAL ENERGY DIVES S IN THE AMPLIFYING NRN STREAM. THIS WILL LEAD TO THE MAIN PCPN EVENT OF THIS FCST CYCLE...OCCURRING WED/THU. MORE ON THIS LATER. CLIPPER SYSTEM PASSING EARLY SAT WILL THEN HERALD THE ARRIVAL OF MUCH COLDER AIR FOR THE WEEKEND...ACCOMPANIED BY LATE SEASON LES AND DIURNALLY DRIVEN SHSN. NEXT PCPN POTENTIAL WILL OCCUR AROUND TUE. BEGINNING TUE NIGHT/WED...IN RESPONSE TO ENERGY EJECTING OUT OF THE SW CONUS AND A WEAKER NRN BRANCH SHORTWAVE SWINGING TOWARD NRN ONTARIO...STRENGTHENING SOUTHERLY FLOW ACROSS THE PLAINS/MISSISSIPPI VALLEY WILL TRANSPORT INCREASING MOISTURE UP THE PLAINS TOWARD THE UPPER LAKES. UNDER THE STRENGTHENING MOISTURE TRANSPORT AND ISENTROPIC ASCENT AS VIEWED ON THE 290-295K SURFACES...EXPECT RAIN TO DEVELOP W TO E TUE NIGHT/WED MORNING. UNDER SLOW HEIGHT FALLS AND UPWARD MOTION...THERE ARE SOME HINTS THAT THE COLUMN MAY COOL JUST ENOUGH FOR THE RAIN TO MIX WITH SNOW OVER NW UPPER MI LATE TUE NIGHT/WED. HOWEVER...WITH THE COLD FRONT ASSOCIATED WITH THE NRN BRANCH SHORTWAVE NOT ARRIVING UNTIL LATER WED AFTN AT THE EARLIEST...ANY MIX OF RAIN WITH SNOW WILL LIKELY HOLD OFF UNTIL AFTER FROPA. AS ENERGY LIFTS OUT ACROSS THE PLAINS INTO THE GREAT LAKES WED NIGHT/THU...DEGREE OF PHASING WITH NRN STREAM ENERGY DIVING S INTO THE PLAINS WILL DETERMINE TRACK/STRENGTH OF THE SFC LOW PRES TRACKING FROM THE CNTRL PLAINS INTO THE GREAT LAKES. PHASING IS FURTHER COMPLICATED BY ANOTHER SHORTWAVE DIVING SSE THRU MANITOBA. AT THIS POINT...IT DOES NOT APPEAR THAT A WELL DEVELOPED/WRAPPED UP WINTER STORM WILL EVOLVE FROM THIS MESS OF SHORTWAVES...BUT THAT`S NOT TO SAY THAT SOME MDT TO PERHAPS HVY SNOW ACCUMULATIONS WON`T OCCUR SOMEWHERE OVER THE UPPER MISSISSIPPI VALLEY AND PARTS OF THE UPPER LAKES. AS OPPOSED TO MEDIUM RANGE GUIDANCE IN PREVIOUS DAYS... ROUGHLY THE LAST DAY OF GUIDANCE IS SHOWING BETTER CONVERGENCE TOWARD A SFC LOW TRACK FROM THE WRN PLAINS ENE ACROSS WI INTO FAR ERN UPPER MI/STRAITS AREA. DEGREE OF PHASING OF SHORTWAVES WHICH WILL AFFECT THE SFC LOW INTENSIFICATION IS UNCERTAIN. IF THE SHORTWAVES BECOME BETTER PHASED...A MORE ORGANIZED STORM SYSTEM WILL DEVELOP WITH A HEAVIER/MORE PRONOUNCED DEFORMATION PCPN BAND DEVELOPING FARTHER INTO THE COLD AIR...RESULTING IN A GREATER RISK OF A HEAVY SNOWFALL ACROSS AT LEAST PORTIONS OF UPPER MI. WEAKER PHASING WILL LEAD TO A LESSER RISK OF HEAVY SNOWFALL. WITH THE UNCERTAINTIES INVOLVED IN STRENGTH OF SYSTEM AND THERMAL PROFILES...WILL UTILIZE A BLENDED APPROACH OF RECENT MODEL RUNS TO CONSTRUCT PCPN AMOUNTS AND PTYPE. AT THIS POINT...THE NW HALF OF UPPER MI HAS THE GREATEST POTENTIAL OF SEEING SNOW ACCUMULATIONS THAT MAY REQUIRE A HEADLINE WED NIGHT/THU. MAIN SYNOPTIC PCPN SHIELD WILL DEPART LATER THU/THU EVENING. AFOREMENTIONED SHORTWAVE IN MANITOBA WILL SWING THRU NRN ONTARIO/UPPER LAKES ON FRI...PROVIDING AT LEAST SCT -SHSN THAT WILL LIKELY BE ENHANCED BY DIURNAL HEATING. STRONGER SHORTWAVE AND ARCTIC COLD FRONT PASS ACROSS THE AREA SAT MORNING. WITH 850MB TEMPS FALLING TO -14 TO -17C SAT...LOOKS LIKE A SPRING-TIME HYBRID TYPE OF LAKE EFFECT SCENARIO AS DAYTIME HEATING DISRUPTS LES PROCESSES AND LEADS TO VIGOROUS SCT-NMRS DIURNALLY DRIVEN SHSN ACROSS THE ENTIRE AREA UNDER CYCLONIC FLOW AND COLD AIR ALOFT. -SHSN WOULD THEN TRANSITION BACK TO A MORE TYPICAL LES REGIME SAT NIGHT/SUN MORNING AS 850MB TEMPS FALL TOWARD -20C. WITH OVERALL MODEL TRENDS TOWARD A FASTER WEAKENING OF THE WRN RIDGE AND THUS A QUICKER DEPARTURE OF COLD AIR...MAY NOT SEE AS MUCH DIURNALLY DRIVEN SHSN ACTIVITY ON SUN AS LES PROCESSES GET DISRUPTED AGAIN BY DAYTIME HEATING. ON MON...THERE ARE INDICATIONS THAT A SHORTWAVE MAY STREAK INTO THE WRN GREAT LAKES ON THE SRN EDGE OF THE RETREATING ARCTIC AIR...BUT MODELS SHOW LITTLE RUN-TO-RUN CONTINUITY...TYPICAL FOR A SMALLER SCALE FEATURE AT THIS TIME RANGE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 124 PM EDT MON MAR 28 2016 ALTHOUGH SOME LO CLDS MAY LINGER AT SAW EARLY IN THE FCST PERIOD... DRY HI PRES BLDG INTO THE UPR LKS WL RESULT IN PREDOMINANT VFR CONDITIONS AT THE TAF SITES THIS FCST PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 357 PM EDT MON MAR 28 2016 HI PRES BUILDING INTO THE UPPER LAKES WILL BRING LIGHT WINDS INTO TUE. BUT AS THIS HI SHIFTS TO THE E AND THE PRES GRADIENT TIGHTENS ACROSS THE WESTERN GREAT LAKES TO THE E OF DEVELOPING LO PRES IN THE PLAINS...EXPECT ESE VEERING SSW WINDS INCREASING UP TO 25 KTS INTO WED. AS THE LO TRACKS JUST TO THE S ON WED INTO THU...WINDS WILL SHIFT TO THE NNE AND INCREASE UP TO GALE FORCE OVER MUCH OF THE LAKE LATE WED NIGHT AND THU. WINDS WILL THEN DIMINISH A BIT LATE IN THE WEEK AS A WEAK TRAILING HI PRES MOVES OVER THE AREA. ANOTHER ROUND OF STRONG N WINDS THAT MAY REACH GALE FORCE COULD DEVELOP ON SAT FOLLOWING THE PASSAGE OF ANOTHER LO PRES THROUGH THE UPPER LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...ROLFSON AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
357 PM EDT MON MAR 28 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 357 PM EDT MON MAR 28 2016 12Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW AN UPR TROF EXTENDING FM QUEBEC INTO THE GREAT LKS DOWNSTREAM OF A RDG IN THE PLAINS AND A DEEPENING TROF OVER WRN NAMERICA. SHRTWV/DEEP LO PRES ARE MOVING THRU SE CANADA. ALTHOUGH THE DEEP MSTR ASSOCIATED WITH THIS DISTURBANCE IS NOW E OF THE CWA...SOME SC LINGERS OVER THE ERN CWA IN THE THERMAL TROF /H85 TEMPS ARND -4C/ AND SLOWLY WEAKENING CYC NLY FLOW LEFT IN THE WAKE OF THE DEPARTING SFC LO. BUT MORE ACYC FLOW EXTENDING S FM HI CENTER OVER FAR NW ONTARIO/ARRIVAL OF DRIER LLVL AIR SHOWN ON THE 12Z INL AND YPL RAOBS AS WELL AS DAYTIME HEATING/MIXING HAS ERODED THE LO CLDS OVER THE W. THERE IS ANOTHER SHRTWV/AREA OF MID CLDS MOVING INTO WRN LK SUP...BUT LARGER SCALE QVECTOR DVGC/SUBSIDENCE IN THE WAKE OF THE DEPARTING STRONGER SHRTWV IS CAUSING THESE MID CLDS TO DIMINISH AS THE TRAILING DISTURBANCE SLIDES INTO THE UPR LKS. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON CLDS TRENDS/IMPACT ON TEMPS. TNGT...THE HI PRES IN NW ONTARIO IS PROGGED TO BUILD SLOWLY S UNDER CONFLUENT NW FLOW E OF UPR RDG IN THE PLAINS THAT IS FCST TO BUILD IN MN OVERNGT. EXPECT MID CLDS ASSOCIATED WITH APRCHG SHRTWV TO CONTINUE TO DSPT IN THE LARGER SCALE QVECTOR DVGC/SUBSIDENCE AHEAD OF THIS RDG. ALTHOUGH SOME OF THE MODELS INDICATE LO CLDS MAY PERSIST OR REFORM OVER THE ERN CWA IN THE NLY FLOW AHEAD OF THE APRCHING HI PRES...DRYING/CLRG TRENDS UPSTREAM HINT THE GUIDANCE SHOWING LESS IN THE WAY OF CLD COVER IS ON THE RIGHT TRACK. WITH PWAT FCST TO FALL TO NEAR 0.20 INCH AND LIGHT WINDS UNDER THE MOCLR SKIES...EXPECT LO TEMPS TO FALL INTO THE TEENS AT SOME OF THE COLDER INTERIOR LOCATIONS OVER THE W AND CENTRAL CWA. TUE...INCRSG SLY FLOW ON THE WRN FLANK OF HI PRES RETREATING TO THE E IS FCST TO LIFT H85 TEMPS TO ARND 2C IN THE AFTN. ALTHOUGH THERE MAY BE SOME HI CLDS SPILLING OVER UPR RDG AXIS SHIFTING OVER THE WRN GREAT LKS...A GOOD DEAL OF SUNSHINE SHOULD BOOST MAX TEMPS WELL INTO THE 50S/CLOSE TO 60 OVER THE FAR W WHERE THE STEADY SLY FLOW WL DOWNSLOPE. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 351 AM EDT MON MAR 28 2016 FOCUS ON WED NIGHT-THU AND INTO THE WEEKEND AS A COMPLEX LOW PRESSURE SYSTEM MOVES THROUGH AND COLDER AIR GLANCES THE AREA THIS WEEKEND. MODELS ARE IN BETTER THAN NORMAL CONFIDENCE IN SHOWING A SOUTHERN STREAM SYSTEM MOVING INTO THE PLAINS BEFORE BEING KICKED E BY A NORTHERN STREAM SHORTWAVE. THE NORTHERN STREAM PUNCH WILL CAUSE INTENSIFICATION OF THE SYSTEM AS PHASING AND JET STREAM COUPLING OCCUR...AND MODELS HAVE BEEN TRENDING STRONGER WITH BETTER PHASING. MORE MINOR...RAIN WILL MOVE INTO THE AREA AHEAD OF THE SYSTEM TUE NIGHT INTO WED. THE 00Z/28 GFS AND 12Z/27 ECMWF ARE IN EXCELLENT AGREEMENT...WITH THE 00Z/28 GLOBAL GEM TRENDING TOWARD THESE MODELS. HOWEVER...THE 00Z/28 NAM IS VERY DIFFERENT...SO WILL NOT USE THAT MODEL AND STICK WITH A GFS/ECMWF BLEND. DYNAMIC COOLING ALONG WITH CAA WILL TRANSITION RAIN TO SNOW ON THE NW SIDE OF THE 850MB LOW TRACK LATE WED EVENING INTO WED NIGHT...THEN BEHIND THE SYSTEM AS IT PULLS OUT THU. RIGHT NOW...THE GFS AND ECMWF SHOW A 984MB SFC LOW MOVING FROM GRB AT 12Z THU TO NEAR THE STRAITS OF MACK AT 981MB BY 18Z THU...THEN INTO CANADA BY 00Z FRI. THIS TRACK RESULTS IN SEVERAL INCHES (POSSIBLY OVER A FOOT GIVEN QPF OF 1-1.25 INCHES FROM THE ECMWF AND UP TO 1.5 INCHES FROM THE GFS...BOTH DURING TIMES WHEN PRECIP SHOULD BE ALL OR MOSTLY SNOW) OF HEAVY SNOW TO MAINLY NW OF A LINE FROM MUNISING TO IRON MOUNTAIN...WITH THE HEAVIEST SWATH FROM WATERSMEET TO BARAGA/L`ANSE. THIS IS A PRETTY VOLATILE SYSTEM...SO EXACTLY WHERE THE HEAVIEST SNOW FALLS IS STILL UNCERTAIN. BIG FOCUS RIGHT NOW IS THAT THERE IS POTENTIAL FOR HEAVY SNOW...SO STAY TUNED. 850MB TEMPS WILL BE AROUND -13C FRI...WHICH WILL BE GOOD FOR SCATTERED SNOW SHOWERS MAINLY NEAR LAKE SUPERIOR. MODELS CONTINUE TO SHOW COLDER AIR FOR THE WEEKEND...BUT THEY HAVE BEEN TRENDING MORE TOWARD A GLANCING SHOT AND WARMER OVERALL. WILL KEEP LIKELY LES POPS SAT INTO SUN...BUT TOO EARLY TO TALK ABOUT AMOUNTS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 124 PM EDT MON MAR 28 2016 ALTHOUGH SOME LO CLDS MAY LINGER AT SAW EARLY IN THE FCST PERIOD... DRY HI PRES BLDG INTO THE UPR LKS WL RESULT IN PREDOMINANT VFR CONDITIONS AT THE TAF SITES THIS FCST PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 357 PM EDT MON MAR 28 2016 HI PRES BUILDING INTO THE UPPER LAKES WILL BRING LIGHT WINDS INTO TUE. BUT AS THIS HI SHIFTS TO THE E AND THE PRES GRADIENT TIGHTENS ACROSS THE WESTERN GREAT LAKES TO THE E OF DEVELOPING LO PRES IN THE PLAINS...EXPECT ESE VEERING SSW WINDS INCREASING UP TO 25 KTS INTO WED. AS THE LO TRACKS JUST TO THE S ON WED INTO THU...WINDS WILL SHIFT TO THE NNE AND INCREASE UP TO GALE FORCE OVER MUCH OF THE LAKE LATE WED NIGHT AND THU. WINDS WILL THEN DIMINISH A BIT LATE IN THE WEEK AS A WEAK TRAILING HI PRES MOVES OVER THE AREA. ANOTHER ROUND OF STRONG N WINDS THAT MAY REACH GALE FORCE COULD DEVELOP ON SAT FOLLOWING THE PASSAGE OF ANOTHER LO PRES THROUGH THE UPPER LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
124 PM EDT MON MAR 28 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 452 AM EDT MON MAR 28 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A STRONG SHORTWAVE TRACKING E THROUGH THE OHIO VALLEY AND LOWER GREAT LAKES REGION. SHORTWAVE DROPPING SE THROUGH THE NORTHERN PLAINS SUPPORTING SOME MID CLOUDS OVER ERN ND AND NRN MN. AT SFC...TIGHT GRADIENT ON BACKSIDE OF LOW CENTERED OVER THE SRN TIP OF LAKE HURON HAS SUPPORTED NORTHERLY WINDS OF 20-25 KNOTS OVER ERN LAKE SUPERIOR EARLY THIS MORNING. LINGERING SHALLOW LOW-LVL MOISTURE ASSOC WITH THE SFC LOW COMBINED WITH ONSHORE/UPSLOPE NORTHERLY WINDS HAS SUPPORTED DZ/FZDZ AND PATCHY FOG OVER PORTIONS OF NCNTRL UPPER MI EARLY THIS MORNING. NOT EXPECTING FZDZ TO CAUSE MANY ISSUES ON ROADS/SIDEWALKS AS WARM GROUND AND NEAR FREEZING TEMPS SHOULD LIMIT ICE ACCUMULATION. AT SAME TIME...NORTHERLY WINDS ARE DRAWING IN INCREASINGLY DRIER AIR FROM NORTH OF LAKE SUPERIOR ALLOWING FOR CLEARING OF LOW CLOUDS AND FOG OVER WRN AND NCNTRL LAKE SUPERIOR AND OVER PORTIONS OF WRN UPPER MI. MODEL SOUNDINGS...SATELLITE AND RADAR TRENDS SUGGEST DRIER AIR AT LOW-LVLS WILL CONTINUE TO WORK INTO CENTRAL UPPER MI THROUGH LATE MORNING WITH CONTINUED ADVANCEMENT OF SFC RDGG FROM NORTHERN ONTARIO. THIS DRYING SHOULD EFFECTIVELY PUT END TO LINGERING DZ/PATCHY FOG BY LATE MORNING. EXPECT DECREASING CLOUDS...BUT WOULDN`T BE SURPRISED IF SKY REMAINS MOSTLY CLOUDY OVER PORTIONS OF NCNTRL/ERN CWA UNDER LINGERING CYCLONIC UPSLOPE NORTHERLY FLOW. WITH SURFACE RIDGE CENTERED OVER THE UPPER GREAT LAKES TONIGHT...EXPECT A SEASONABLY COLD FROSTY NIGHT WITH LOWS IN THE TEENS AND 20S UNDER CLEAR SKIES AND LIGHT WINDS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 351 AM EDT MON MAR 28 2016 FOCUS ON WED NIGHT-THU AND INTO THE WEEKEND AS A COMPLEX LOW PRESSURE SYSTEM MOVES THROUGH AND COLDER AIR GLANCES THE AREA THIS WEEKEND. MODELS ARE IN BETTER THAN NORMAL CONFIDENCE IN SHOWING A SOUTHERN STREAM SYSTEM MOVING INTO THE PLAINS BEFORE BEING KICKED E BY A NORTHERN STREAM SHORTWAVE. THE NORTHERN STREAM PUNCH WILL CAUSE INTENSIFICATION OF THE SYSTEM AS PHASING AND JET STREAM COUPLING OCCUR...AND MODELS HAVE BEEN TRENDING STRONGER WITH BETTER PHASING. MORE MINOR...RAIN WILL MOVE INTO THE AREA AHEAD OF THE SYSTEM TUE NIGHT INTO WED. THE 00Z/28 GFS AND 12Z/27 ECMWF ARE IN EXCELLENT AGREEMENT...WITH THE 00Z/28 GLOBAL GEM TRENDING TOWARD THESE MODELS. HOWEVER...THE 00Z/28 NAM IS VERY DIFFERENT...SO WILL NOT USE THAT MODEL AND STICK WITH A GFS/ECMWF BLEND. DYNAMIC COOLING ALONG WITH CAA WILL TRANSITION RAIN TO SNOW ON THE NW SIDE OF THE 850MB LOW TRACK LATE WED EVENING INTO WED NIGHT...THEN BEHIND THE SYSTEM AS IT PULLS OUT THU. RIGHT NOW...THE GFS AND ECMWF SHOW A 984MB SFC LOW MOVING FROM GRB AT 12Z THU TO NEAR THE STRAITS OF MACK AT 981MB BY 18Z THU...THEN INTO CANADA BY 00Z FRI. THIS TRACK RESULTS IN SEVERAL INCHES (POSSIBLY OVER A FOOT GIVEN QPF OF 1-1.25 INCHES FROM THE ECMWF AND UP TO 1.5 INCHES FROM THE GFS...BOTH DURING TIMES WHEN PRECIP SHOULD BE ALL OR MOSTLY SNOW) OF HEAVY SNOW TO MAINLY NW OF A LINE FROM MUNISING TO IRON MOUNTAIN...WITH THE HEAVIEST SWATH FROM WATERSMEET TO BARAGA/L`ANSE. THIS IS A PRETTY VOLATILE SYSTEM...SO EXACTLY WHERE THE HEAVIEST SNOW FALLS IS STILL UNCERTAIN. BIG FOCUS RIGHT NOW IS THAT THERE IS POTENTIAL FOR HEAVY SNOW...SO STAY TUNED. 850MB TEMPS WILL BE AROUND -13C FRI...WHICH WILL BE GOOD FOR SCATTERED SNOW SHOWERS MAINLY NEAR LAKE SUPERIOR. MODELS CONTINUE TO SHOW COLDER AIR FOR THE WEEKEND...BUT THEY HAVE BEEN TRENDING MORE TOWARD A GLANCING SHOT AND WARMER OVERALL. WILL KEEP LIKELY LES POPS SAT INTO SUN...BUT TOO EARLY TO TALK ABOUT AMOUNTS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 124 PM EDT MON MAR 28 2016 ALTHOUGH SOME LO CLDS MAY LINGER AT SAW EARLY IN THE FCST PERIOD... DRY HI PRES BLDG INTO THE UPR LKS WL RESULT IN PREDOMINANT VFR CONDITIONS AT THE TAF SITES THIS FCST PERIOD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 452 AM EDT MON MAR 28 2016 WITH LOW PRES TRACKING THRU THE LOWER GREAT LAKES REGION THIS MORNING..NNW WINDS 15-25KT ARE EXPECTED OVER THE E HALF OF LAKE SUPERIOR TODAY. CLOSER TO AN ADVANCING HIGH PRES RIDGE...WINDS WILL BE LIGHTER OVER WRN LAKE SUPERIOR. LIGHT WINDS...MOSTLY UNDER 15KT...WILL THEN BECOME THE RULE ACROSS THE LAKE TONIGHT THRU AT LEAST TUE MORNING AS A HIGH PRES RIDGE PASSES. SE TO S WINDS WILL THEN BE ON THE INCREASE LATER TUE THRU WED AHEAD OF AN APPROACHING COLD FRONT. TYPICAL FOR THIS TYPE OF FLOW... STRONGEST WINDS WILL LIKELY BE OVER ERN LAKE SUPERIOR...PROBABLY TO 20-30KT. AS THE COLD FRONT PASSES WED NIGHT AND A LOW PRES WAVE TRACKS LONG THE FRONT...WINDS WILL SHIFT TO THE NE TO NEAR 30KT WED NIGHT. AT THIS TIME FORECAST MODELS SUGGEST NE-N GALES TO 35 KNOTS ARE POSSIBLE FOR THU/THU EVENING. WINDS WILL DIMINISH A LITTLE ON FRI BEFORE A STRONG ARCTIC COLD FRONT PASSES EARLY SAT...USHERING IN A PERIOD OF GALES DURING THE DAY SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...TITUS AVIATION...KC MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
743 AM EDT MON MAR 28 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 452 AM EDT MON MAR 28 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A STRONG SHORTWAVE TRACKING E THROUGH THE OHIO VALLEY AND LOWER GREAT LAKES REGION. SHORTWAVE DROPPING SE THROUGH THE NORTHERN PLAINS SUPPORTING SOME MID CLOUDS OVER ERN ND AND NRN MN. AT SFC...TIGHT GRADIENT ON BACKSIDE OF LOW CENTERED OVER THE SRN TIP OF LAKE HURON HAS SUPPORTED NORTHERLY WINDS OF 20-25 KNOTS OVER ERN LAKE SUPERIOR EARLY THIS MORNING. LINGERING SHALLOW LOW-LVL MOISTURE ASSOC WITH THE SFC LOW COMBINED WITH ONSHORE/UPSLOPE NORTHERLY WINDS HAS SUPPORTED DZ/FZDZ AND PATCHY FOG OVER PORTIONS OF NCNTRL UPPER MI EARLY THIS MORNING. NOT EXPECTING FZDZ TO CAUSE MANY ISSUES ON ROADS/SIDEWALKS AS WARM GROUND AND NEAR FREEZING TEMPS SHOULD LIMIT ICE ACCUMULATION. AT SAME TIME...NORTHERLY WINDS ARE DRAWING IN INCREASINGLY DRIER AIR FROM NORTH OF LAKE SUPERIOR ALLOWING FOR CLEARING OF LOW CLOUDS AND FOG OVER WRN AND NCNTRL LAKE SUPERIOR AND OVER PORTIONS OF WRN UPPER MI. MODEL SOUNDINGS...SATELLITE AND RADAR TRENDS SUGGEST DRIER AIR AT LOW-LVLS WILL CONTINUE TO WORK INTO CENTRAL UPPER MI THROUGH LATE MORNING WITH CONTINUED ADVANCEMENT OF SFC RDGG FROM NORTHERN ONTARIO. THIS DRYING SHOULD EFFECTIVELY PUT END TO LINGERING DZ/PATCHY FOG BY LATE MORNING. EXPECT DECREASING CLOUDS...BUT WOULDN`T BE SURPRISED IF SKY REMAINS MOSTLY CLOUDY OVER PORTIONS OF NCNTRL/ERN CWA UNDER LINGERING CYCLONIC UPSLOPE NORTHERLY FLOW. WITH SURFACE RIDGE CENTERED OVER THE UPPER GREAT LAKES TONIGHT...EXPECT A SEASONABLY COLD FROSTY NIGHT WITH LOWS IN THE TEENS AND 20S UNDER CLEAR SKIES AND LIGHT WINDS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 351 AM EDT MON MAR 28 2016 FOCUS ON WED NIGHT-THU AND INTO THE WEEKEND AS A COMPLEX LOW PRESSURE SYSTEM MOVES THROUGH AND COLDER AIR GLANCES THE AREA THIS WEEKEND. MODELS ARE IN BETTER THAN NORMAL CONFIDENCE IN SHOWING A SOUTHERN STREAM SYSTEM MOVING INTO THE PLAINS BEFORE BEING KICKED E BY A NORTHERN STREAM SHORTWAVE. THE NORTHERN STREAM PUNCH WILL CAUSE INTENSIFICATION OF THE SYSTEM AS PHASING AND JET STREAM COUPLING OCCUR...AND MODELS HAVE BEEN TRENDING STRONGER WITH BETTER PHASING. MORE MINOR...RAIN WILL MOVE INTO THE AREA AHEAD OF THE SYSTEM TUE NIGHT INTO WED. THE 00Z/28 GFS AND 12Z/27 ECMWF ARE IN EXCELLENT AGREEMENT...WITH THE 00Z/28 GLOBAL GEM TRENDING TOWARD THESE MODELS. HOWEVER...THE 00Z/28 NAM IS VERY DIFFERENT...SO WILL NOT USE THAT MODEL AND STICK WITH A GFS/ECMWF BLEND. DYNAMIC COOLING ALONG WITH CAA WILL TRANSITION RAIN TO SNOW ON THE NW SIDE OF THE 850MB LOW TRACK LATE WED EVENING INTO WED NIGHT...THEN BEHIND THE SYSTEM AS IT PULLS OUT THU. RIGHT NOW...THE GFS AND ECMWF SHOW A 984MB SFC LOW MOVING FROM GRB AT 12Z THU TO NEAR THE STRAITS OF MACK AT 981MB BY 18Z THU...THEN INTO CANADA BY 00Z FRI. THIS TRACK RESULTS IN SEVERAL INCHES (POSSIBLY OVER A FOOT GIVEN QPF OF 1-1.25 INCHES FROM THE ECMWF AND UP TO 1.5 INCHES FROM THE GFS...BOTH DURING TIMES WHEN PRECIP SHOULD BE ALL OR MOSTLY SNOW) OF HEAVY SNOW TO MAINLY NW OF A LINE FROM MUNISING TO IRON MOUNTAIN...WITH THE HEAVIEST SWATH FROM WATERSMEET TO BARAGA/L`ANSE. THIS IS A PRETTY VOLATILE SYSTEM...SO EXACTLY WHERE THE HEAVIEST SNOW FALLS IS STILL UNCERTAIN. BIG FOCUS RIGHT NOW IS THAT THERE IS POTENTIAL FOR HEAVY SNOW...SO STAY TUNED. 850MB TEMPS WILL BE AROUND -13C FRI...WHICH WILL BE GOOD FOR SCATTERED SNOW SHOWERS MAINLY NEAR LAKE SUPERIOR. MODELS CONTINUE TO SHOW COLDER AIR FOR THE WEEKEND...BUT THEY HAVE BEEN TRENDING MORE TOWARD A GLANCING SHOT AND WARMER OVERALL. WILL KEEP LIKELY LES POPS SAT INTO SUN...BUT TOO EARLY TO TALK ABOUT AMOUNTS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 737 AM EDT MON MAR 28 2016 VLIFR CONDITIONS AT KIWD AND IFR CONDITIONS AT KCMX WILL IMPROVE TO MVFR LATER THIS MORNING AND TO VFR EARLY THIS AFTERNOON THROUGH THE FCST PD AS DRIER AIR CONTINUES TO FILTER IN FROM THE NORTH. AT KSAW...LOW MVFR CIGS WILL CONTINUE TO IMPROVE THROUGH THE MORNING WITH VFR CONDITIONS EXPECTED EARLY THIS AFTERNOON THROUGH THE FCST PD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 452 AM EDT MON MAR 28 2016 WITH LOW PRES TRACKING THRU THE LOWER GREAT LAKES REGION THIS MORNING..NNW WINDS 15-25KT ARE EXPECTED OVER THE E HALF OF LAKE SUPERIOR TODAY. CLOSER TO AN ADVANCING HIGH PRES RIDGE...WINDS WILL BE LIGHTER OVER WRN LAKE SUPERIOR. LIGHT WINDS...MOSTLY UNDER 15KT...WILL THEN BECOME THE RULE ACROSS THE LAKE TONIGHT THRU AT LEAST TUE MORNING AS A HIGH PRES RIDGE PASSES. SE TO S WINDS WILL THEN BE ON THE INCREASE LATER TUE THRU WED AHEAD OF AN APPROACHING COLD FRONT. TYPICAL FOR THIS TYPE OF FLOW... STRONGEST WINDS WILL LIKELY BE OVER ERN LAKE SUPERIOR...PROBABLY TO 20-30KT. AS THE COLD FRONT PASSES WED NIGHT AND A LOW PRES WAVE TRACKS LONG THE FRONT...WINDS WILL SHIFT TO THE NE TO NEAR 30KT WED NIGHT. AT THIS TIME FORECAST MODELS SUGGEST NE-N GALES TO 35 KNOTS ARE POSSIBLE FOR THU/THU EVENING. WINDS WILL DIMINISH A LITTLE ON FRI BEFORE A STRONG ARCTIC COLD FRONT PASSES EARLY SAT...USHERING IN A PERIOD OF GALES DURING THE DAY SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...TITUS AVIATION...VOSS MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
453 AM EDT MON MAR 28 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 452 AM EDT MON MAR 28 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A STRONG SHORTWAVE TRACKING E THROUGH THE OHIO VALLEY AND LOWER GREAT LAKES REGION. SHORTWAVE DROPPING SE THROUGH THE NORTHERN PLAINS SUPPORTING SOME MID CLOUDS OVER ERN ND AND NRN MN. AT SFC...TIGHT GRADIENT ON BACKSIDE OF LOW CENTERED OVER THE SRN TIP OF LAKE HURON HAS SUPPORTED NORTHERLY WINDS OF 20-25 KNOTS OVER ERN LAKE SUPERIOR EARLY THIS MORNING. LINGERING SHALLOW LOW-LVL MOISTURE ASSOC WITH THE SFC LOW COMBINED WITH ONSHORE/UPSLOPE NORTHERLY WINDS HAS SUPPORTED DZ/FZDZ AND PATCHY FOG OVER PORTIONS OF NCNTRL UPPER MI EARLY THIS MORNING. NOT EXPECTING FZDZ TO CAUSE MANY ISSUES ON ROADS/SIDEWALKS AS WARM GROUND AND NEAR FREEZING TEMPS SHOULD LIMIT ICE ACCUMULATION. AT SAME TIME...NORTHERLY WINDS ARE DRAWING IN INCREASINGLY DRIER AIR FROM NORTH OF LAKE SUPERIOR ALLOWING FOR CLEARING OF LOW CLOUDS AND FOG OVER WRN AND NCNTRL LAKE SUPERIOR AND OVER PORTIONS OF WRN UPPER MI. MODEL SOUNDINGS...SATELLITE AND RADAR TRENDS SUGGEST DRIER AIR AT LOW-LVLS WILL CONTINUE TO WORK INTO CENTRAL UPPER MI THROUGH LATE MORNING WITH CONTINUED ADVANCEMENT OF SFC RDGG FROM NORTHERN ONTARIO. THIS DRYING SHOULD EFFECTIVELY PUT END TO LINGERING DZ/PATCHY FOG BY LATE MORNING. EXPECT DECREASING CLOUDS...BUT WOULDN`T BE SURPRISED IF SKY REMAINS MOSTLY CLOUDY OVER PORTIONS OF NCNTRL/ERN CWA UNDER LINGERING CYCLONIC UPSLOPE NORTHERLY FLOW. WITH SURFACE RIDGE CENTERED OVER THE UPPER GREAT LAKES TONIGHT...EXPECT A SEASONABLY COLD FROSTY NIGHT WITH LOWS IN THE TEENS AND 20S UNDER CLEAR SKIES AND LIGHT WINDS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 351 AM EDT MON MAR 28 2016 FOCUS ON WED NIGHT-THU AND INTO THE WEEKEND AS A COMPLEX LOW PRESSURE SYSTEM MOVES THROUGH AND COLDER AIR GLANCES THE AREA THIS WEEKEND. MODELS ARE IN BETTER THAN NORMAL CONFIDENCE IN SHOWING A SOUTHERN STREAM SYSTEM MOVING INTO THE PLAINS BEFORE BEING KICKED E BY A NORTHERN STREAM SHORTWAVE. THE NORTHERN STREAM PUNCH WILL CAUSE INTENSIFICATION OF THE SYSTEM AS PHASING AND JET STREAM COUPLING OCCUR...AND MODELS HAVE BEEN TRENDING STRONGER WITH BETTER PHASING. MORE MINOR...RAIN WILL MOVE INTO THE AREA AHEAD OF THE SYSTEM TUE NIGHT INTO WED. THE 00Z/28 GFS AND 12Z/27 ECMWF ARE IN EXCELLENT AGREEMENT...WITH THE 00Z/28 GLOBAL GEM TRENDING TOWARD THESE MODELS. HOWEVER...THE 00Z/28 NAM IS VERY DIFFERENT...SO WILL NOT USE THAT MODEL AND STICK WITH A GFS/ECMWF BLEND. DYNAMIC COOLING ALONG WITH CAA WILL TRANSITION RAIN TO SNOW ON THE NW SIDE OF THE 850MB LOW TRACK LATE WED EVENING INTO WED NIGHT...THEN BEHIND THE SYSTEM AS IT PULLS OUT THU. RIGHT NOW...THE GFS AND ECMWF SHOW A 984MB SFC LOW MOVING FROM GRB AT 12Z THU TO NEAR THE STRAITS OF MACK AT 981MB BY 18Z THU...THEN INTO CANADA BY 00Z FRI. THIS TRACK RESULTS IN SEVERAL INCHES (POSSIBLY OVER A FOOT GIVEN QPF OF 1-1.25 INCHES FROM THE ECMWF AND UP TO 1.5 INCHES FROM THE GFS...BOTH DURING TIMES WHEN PRECIP SHOULD BE ALL OR MOSTLY SNOW) OF HEAVY SNOW TO MAINLY NW OF A LINE FROM MUNISING TO IRON MOUNTAIN...WITH THE HEAVIEST SWATH FROM WATERSMEET TO BARAGA/L`ANSE. THIS IS A PRETTY VOLATILE SYSTEM...SO EXACTLY WHERE THE HEAVIEST SNOW FALLS IS STILL UNCERTAIN. BIG FOCUS RIGHT NOW IS THAT THERE IS POTENTIAL FOR HEAVY SNOW...SO STAY TUNED. 850MB TEMPS WILL BE AROUND -13C FRI...WHICH WILL BE GOOD FOR SCATTERED SNOW SHOWERS MAINLY NEAR LAKE SUPERIOR. MODELS CONTINUE TO SHOW COLDER AIR FOR THE WEEKEND...BUT THEY HAVE BEEN TRENDING MORE TOWARD A GLANCING SHOT AND WARMER OVERALL. WILL KEEP LIKELY LES POPS SAT INTO SUN...BUT TOO EARLY TO TALK ABOUT AMOUNTS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 136 AM EDT MON MAR 28 2016 DRYING FROM WEST HAS ALLOWED CONDITIONS TO IMPROVE TO VFR AT KIWD BUT THERE MAY BE SOME REDEVELOPMENT OF MVFR/IFR STRATUS OVERNIGHT IN WEAK NORTHERLY UPSLOPE FLOW. EXPECT CONDITIONS AT KCMX TO IMPROVE FROM VLIFR TO AT LEAST IFR OR MVFR OVERNIGHT WITH DRIER AIR ADVECTING IN THE NORTH. CONDITIONS WILL BE SLOWER TO IMPROVE AT KSAW ALTHOUGH EVEN THERE EXPECT IMPROVEMENT TO IFR LATE TONIGHT AS DZ/FZDZ ENDS. AS DRIER AIR CONTINUES TO MAKE INROADS...ALL TERMINALS WILL IMPROVE TO VFR MON MORNING/EARLY AFTN. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 452 AM EDT MON MAR 28 2016 WITH LOW PRES TRACKING THRU THE LOWER GREAT LAKES REGION THIS MORNING..NNW WINDS 15-25KT ARE EXPECTED OVER THE E HALF OF LAKE SUPERIOR TODAY. CLOSER TO AN ADVANCING HIGH PRES RIDGE...WINDS WILL BE LIGHTER OVER WRN LAKE SUPERIOR. LIGHT WINDS...MOSTLY UNDER 15KT...WILL THEN BECOME THE RULE ACROSS THE LAKE TONIGHT THRU AT LEAST TUE MORNING AS A HIGH PRES RIDGE PASSES. SE TO S WINDS WILL THEN BE ON THE INCREASE LATER TUE THRU WED AHEAD OF AN APPROACHING COLD FRONT. TYPICAL FOR THIS TYPE OF FLOW... STRONGEST WINDS WILL LIKELY BE OVER ERN LAKE SUPERIOR...PROBABLY TO 20-30KT. AS THE COLD FRONT PASSES WED NIGHT AND A LOW PRES WAVE TRACKS LONG THE FRONT...WINDS WILL SHIFT TO THE NE TO NEAR 30KT WED NIGHT. AT THIS TIME FORECAST MODELS SUGGEST NE-N GALES TO 35 KNOTS ARE POSSIBLE FOR THU/THU EVENING. WINDS WILL DIMINISH A LITTLE ON FRI BEFORE A STRONG ARCTIC COLD FRONT PASSES EARLY SAT...USHERING IN A PERIOD OF GALES DURING THE DAY SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...TITUS AVIATION...07/JV MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
352 AM EDT MON MAR 28 2016 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 417 PM EDT SUN MAR 27 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A TROF OVER THE MID AND UPPER MISSISSIPPI VALLEY. ONE WEAKER SHORTWAVE LIFTING NE ACROSS THE UPPER GREAT LAKES HAS AIDED RAIN AND SOME SNOW THAT HAS SPREAD ACROSS WRN AND NRN UPPER MI TODAY. ANOTHER SHORTWAVE IS OVER MN/ADJACENT NRN ONTARIO. A MUCH STRONGER SHORTWAVE IS TRACKING OVER MO. RAIN ASSOCIATED WITH THAT FEATURE HAS QUICKLY STREAKED NE ACROSS SE WI...NRN LAKE MI AND INTO ERN UPPER MI...FORCED BY RIGHT ENTRANCE OF UPPER JET EXTENDING ENE FROM THE UPPER LAKES AND CORRESPONDING INCREASE IN FGEN IN THE LOW/MID LEVELS. TONIGHT INTO MON MORNING...FOCUS WILL BE ON ENDING LINGERING PCPN. THE AFOREMENTIONED RAIN THAT HAS DEVELOPED NE INTO ERN UPPER MI MAY BRUSH THE SE FCST AREA THRU THE EVENING AS SHORTWAVE SWINGS FROM MO ACROSS SE LWR MI. ACROSS THE REST OF THE AREA...ARRIVAL OF DEEP LAYER QVECTOR DIVERGENCE AND DRYING IN THE MID LEVELS WILL BRING AN END TO PATCHY -RA/-SN. HOWEVER...WITH MID LEVELS GRADUALLY DRYING OUT WHILE ABUNDANT MOISTURE LINGERS AT THE LOW-LEVELS...SOME -DZ/-FZDZ MAY DEVELOP IN THE UPSLOPE AREAS UNDER RATHER PRONOUNCED LOW-LEVEL CYCLONIC NORTHERLY WINDS. ALTHOUGH CLEARING IS NOT FAR AWAY OVER NW LAKE SUPERIOR...LOW-LEVEL TRAJECTORIES TONIGHT INTO MON MORNING SUGGEST AT LEAST THE NCNTRL AND ERN FCST AREA WILL BE TAPPING THE LOW-LEVEL MOISTURE/STRATUS THAT CURRENTLY EXISTS NNE OF LAKE SUPERIOR...WHICH SUPPORTS THE IDEA OF PERSISTENT LOW-LEVEL MOISTURE AND THE POTENTIAL FOR -DZ/-FZDZ. IT ALSO SUGGESTS THAT CLOUDS MAY HOLD ON ACROSS EVEN THE W...PARTICULARY IN THE FACE OF CYCLONIC UPSLOPE FLOW. SHOULD ANY CLEARING OCCUR OVER THE W...RADIATIONAL FOG COULD DEVELOP. WITH MORE PERSISTENT CLOUD COVER...RAISED MINS FOR TONIGHT TO MOSTLY THE MID 20S TO LWR 30S. IF CLOUDS BREAK OVER THE FAR W...TEMPS WILL FALL TOWARD 20F. EXPECT ANY -DZ/-FZDZ TO START THE DAY MON TO END BY AFTN AS LOW- LEVEL MOISTURE THINS A BIT. EXPECT DECREASING CLOUDS...BUT WOULDN`T BE SURPRISED IF SKY REMAINS MOSTLY CLOUDY OVER PARTS OF THE CNTRL/E UNDER LINGERING CYCLONIC FLOW. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 351 AM EDT MON MAR 28 2016 FOCUS ON WED NIGHT-THU AND INTO THE WEEKEND AS A COMPLEX LOW PRESSURE SYSTEM MOVES THROUGH AND COLDER AIR GLANCES THE AREA THIS WEEKEND. MODELS ARE IN BETTER THAN NORMAL CONFIDENCE IN SHOWING A SOUTHERN STREAM SYSTEM MOVING INTO THE PLAINS BEFORE BEING KICKED E BY A NORTHERN STREAM SHORTWAVE. THE NORTHERN STREAM PUNCH WILL CAUSE INTENSIFICATION OF THE SYSTEM AS PHASING AND JET STREAM COUPLING OCCUR...AND MODELS HAVE BEEN TRENDING STRONGER WITH BETTER PHASING. MORE MINOR...RAIN WILL MOVE INTO THE AREA AHEAD OF THE SYSTEM TUE NIGHT INTO WED. THE 00Z/28 GFS AND 12Z/27 ECMWF ARE IN EXCELLENT AGREEMENT...WITH THE 00Z/28 GLOBAL GEM TRENDING TOWARD THESE MODELS. HOWEVER...THE 00Z/28 NAM IS VERY DIFFERENT...SO WILL NOT USE THAT MODEL AND STICK WITH A GFS/ECMWF BLEND. DYNAMIC COOLING ALONG WITH CAA WILL TRANSITION RAIN TO SNOW ON THE NW SIDE OF THE 850MB LOW TRACK LATE WED EVENING INTO WED NIGHT...THEN BEHIND THE SYSTEM AS IT PULLS OUT THU. RIGHT NOW...THE GFS AND ECMWF SHOW A 984MB SFC LOW MOVING FROM GRB AT 12Z THU TO NEAR THE STRAITS OF MACK AT 981MB BY 18Z THU...THEN INTO CANADA BY 00Z FRI. THIS TRACK RESULTS IN SEVERAL INCHES (POSSIBLY OVER A FOOT GIVEN QPF OF 1-1.25 INCHES FROM THE ECMWF AND UP TO 1.5 INCHES FROM THE GFS...BOTH DURING TIMES WHEN PRECIP SHOULD BE ALL OR MOSTLY SNOW) OF HEAVY SNOW TO MAINLY NW OF A LINE FROM MUNISING TO IRON MOUNTAIN...WITH THE HEAVIEST SWATH FROM WATERSMEET TO BARAGA/L`ANSE. THIS IS A PRETTY VOLATILE SYSTEM...SO EXACTLY WHERE THE HEAVIEST SNOW FALLS IS STILL UNCERTAIN. BIG FOCUS RIGHT NOW IS THAT THERE IS POTENTIAL FOR HEAVY SNOW...SO STAY TUNED. 850MB TEMPS WILL BE AROUND -13C FRI...WHICH WILL BE GOOD FOR SCATTERED SNOW SHOWERS MAINLY NEAR LAKE SUPERIOR. MODELS CONTINUE TO SHOW COLDER AIR FOR THE WEEKEND...BUT THEY HAVE BEEN TRENDING MORE TOWARD A GLANCING SHOT AND WARMER OVERALL. WILL KEEP LIKELY LES POPS SAT INTO SUN...BUT TOO EARLY TO TALK ABOUT AMOUNTS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 136 AM EDT MON MAR 28 2016 DRYING FROM WEST HAS ALLOWED CONDITIONS TO IMPROVE TO VFR AT KIWD BUT THERE MAY BE SOME REDEVELOPMENT OF MVFR/IFR STRATUS OVERNIGHT IN WEAK NORTHERLY UPSLOPE FLOW. EXPECT CONDITIONS AT KCMX TO IMPROVE FROM VLIFR TO AT LEAST IFR OR MVFR OVERNIGHT WITH DRIER AIR ADVECTING IN THE NORTH. CONDITIONS WILL BE SLOWER TO IMPROVE AT KSAW ALTHOUGH EVEN THERE EXPECT IMPROVEMENT TO IFR LATE TONIGHT AS DZ/FZDZ ENDS. AS DRIER AIR CONTINUES TO MAKE INROADS...ALL TERMINALS WILL IMPROVE TO VFR MON MORNING/EARLY AFTN. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 417 PM EDT SUN MAR 27 2016 WITH LOW PRES TRACKING THRU THE LOWER GREAT LAKES REGION TONIGHT AND MON MORNING...15-25KT WINDS ARE EXPECTED OVER THE E HALF OF LAKE SUPERIOR LATE TONIGHT AND MON. CLOSER TO AN APPROACHING HIGH PRES RIDGE...WINDS WILL BE LIGHTER OVER WRN LAKE SUPERIOR. LIGHT WINDS...MOSTLY UNDER 15KT...WILL THEN BECOME THE RULE ACROSS THE LAKE MON NIGHT THRU AT LEAST TUE MORNING AS HIGH PRES RIDGE PASSES. SE TO S WINDS WILL THEN BE ON THE INCREASE LATER TUE THRU WED AHEAD OF AN APPROACHING COLD FRONT. TYPICAL FOR THIS TYPE OF FLOW... STRONGEST WINDS WILL LIKELY BE OVER ERN LAKE SUPERIOR...PROBABLY TO 20-30KT. AS THE COLD FRONT PASSES WED NIGHT AND A LOW PRES WAVE TRACKS LONG THE FRONT...WINDS WILL SHIFT TO THE NE AND N IN THE 20- 30KT RANGE. WINDS MAY GUST TO GALE FORCE FOR AT LEAST A PART OF THU/THU EVENING...DEPENDING ON THE STRENGTH OF THE LOW PRES WAVE. WINDS WILL DIMINISH A LITTLE ON FRI BEFORE A STRONG ARCTIC COLD FRONT PASSES EARLY SAT...USHERING IN A PERIOD OF GALES DURING THE DAY SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...07/JV MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
143 AM EDT MON MAR 28 2016 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 417 PM EDT SUN MAR 27 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A TROF OVER THE MID AND UPPER MISSISSIPPI VALLEY. ONE WEAKER SHORTWAVE LIFTING NE ACROSS THE UPPER GREAT LAKES HAS AIDED RAIN AND SOME SNOW THAT HAS SPREAD ACROSS WRN AND NRN UPPER MI TODAY. ANOTHER SHORTWAVE IS OVER MN/ADJACENT NRN ONTARIO. A MUCH STRONGER SHORTWAVE IS TRACKING OVER MO. RAIN ASSOCIATED WITH THAT FEATURE HAS QUICKLY STREAKED NE ACROSS SE WI...NRN LAKE MI AND INTO ERN UPPER MI...FORCED BY RIGHT ENTRANCE OF UPPER JET EXTENDING ENE FROM THE UPPER LAKES AND CORRESPONDING INCREASE IN FGEN IN THE LOW/MID LEVELS. TONIGHT INTO MON MORNING...FOCUS WILL BE ON ENDING LINGERING PCPN. THE AFOREMENTIONED RAIN THAT HAS DEVELOPED NE INTO ERN UPPER MI MAY BRUSH THE SE FCST AREA THRU THE EVENING AS SHORTWAVE SWINGS FROM MO ACROSS SE LWR MI. ACROSS THE REST OF THE AREA...ARRIVAL OF DEEP LAYER QVECTOR DIVERGENCE AND DRYING IN THE MID LEVELS WILL BRING AN END TO PATCHY -RA/-SN. HOWEVER...WITH MID LEVELS GRADUALLY DRYING OUT WHILE ABUNDANT MOISTURE LINGERS AT THE LOW-LEVELS...SOME -DZ/-FZDZ MAY DEVELOP IN THE UPSLOPE AREAS UNDER RATHER PRONOUNCED LOW-LEVEL CYCLONIC NORTHERLY WINDS. ALTHOUGH CLEARING IS NOT FAR AWAY OVER NW LAKE SUPERIOR...LOW-LEVEL TRAJECTORIES TONIGHT INTO MON MORNING SUGGEST AT LEAST THE NCNTRL AND ERN FCST AREA WILL BE TAPPING THE LOW-LEVEL MOISTURE/STRATUS THAT CURRENTLY EXISTS NNE OF LAKE SUPERIOR...WHICH SUPPORTS THE IDEA OF PERSISTENT LOW-LEVEL MOISTURE AND THE POTENTIAL FOR -DZ/-FZDZ. IT ALSO SUGGESTS THAT CLOUDS MAY HOLD ON ACROSS EVEN THE W...PARTICULARY IN THE FACE OF CYCLONIC UPSLOPE FLOW. SHOULD ANY CLEARING OCCUR OVER THE W...RADIATIONAL FOG COULD DEVELOP. WITH MORE PERSISTENT CLOUD COVER...RAISED MINS FOR TONIGHT TO MOSTLY THE MID 20S TO LWR 30S. IF CLOUDS BREAK OVER THE FAR W...TEMPS WILL FALL TOWARD 20F. EXPECT ANY -DZ/-FZDZ TO START THE DAY MON TO END BY AFTN AS LOW- LEVEL MOISTURE THINS A BIT. EXPECT DECREASING CLOUDS...BUT WOULDN`T BE SURPRISED IF SKY REMAINS MOSTLY CLOUDY OVER PARTS OF THE CNTRL/E UNDER LINGERING CYCLONIC FLOW. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 313 PM EDT SUN MAR 27 2016 THE LONGER RANGE OF THE FORECAST WILL START OFF PRETTY TRANQUIL FOLLOWED BY A MIDWEEK STORM THAT WILL FEATURE RAIN FOLLOWED BY EVEN A LITTLE SNOW. AFTER A BRIEF BREAK LATE IN THE WEEK...THE UPPER GREAT LAKES WILL BE BRUSHED BY A BRIEF BUT COLD SHOT OF AIR LATE NEXT WEEKEND. SURFACE RIDGE WILL BE RIGHT OVER THE UPPER GREAT LAKES MONDAY NIGHT WITH CLEAR SKIES AND LIGHT WINDS ALLOWING FOR A SEASONABLY COLD FROSTY NIGHT WITH LOWS IN THE TEENS AND 20S. CHANGES BEGIN DURING THE DAY TUESDAY AS UPPER LOW BEGINS TO EJECT OUT OF THE ROCKIES. AS IT DOES...SURFACE LOW WILL EMERGE INTO THE PLAINS WITH BRAD SOUTHERLY FLOW AND WARM ADVECTION PUSHING TEMPERATURES INTO THE LOWER TO MIDDLE 50S OVER THE WESTERN U.P. WARM ADVECTION PRECIPITATION WILL BEGIN TO MOVE INTO THE U.P. FROM THE SOUTHWEST LATE TUESDAY NIGHT. THERE IS STILL QUITE A BIT OF UNCERTAINTY WITH THE ACTUAL TIMING AND TRACK OF THE SURFACE LOW THROUGH THE GREAT LAKES. MOST OF THE DISCREPANCIES SEEM TO HINGE ON THE HANDLING OF SHORTWAVE ENERGY MOVING ALONG THE CANADIAN BORDER AND HOW IT INTERACTS WITH THE SOUTHERN STREAM TROUGH. TRENDS SEEM TO INDICATE THAT THE NORTHERN STREAM ENERGY...AT LEAST INITIALLY WILL NOT INTERACT AS MUCH WITH THE SOUTHERN STREAM UPPER LOW LEADING TO A SLIGHTLY SLOWER PROGRESSION TO THE EAST OF THE SURFACE LOW INTO THE LAKES REGION. EXPECT MAINLY LIGHT WARM ADVECTION RAIN TO OVERSPREAD MOST OF THE AREA DURING THE DAY ON WEDNESDAY. WITH MODELS COMING INTO A BETTER CONSENSUS WITH THE SURFACE LOW TRACK ACROSS CENTRAL WI INTO NORTHERN LOWER MI EXPECT ENOUGH COLD AIR TO MOVE INTO THE AREA TO BEGIN TO TRANSITIONING THE RAIN TO SNOW FROM WEST TO EAST WEDNESDAY NIGHT INTO THURSDAY. A SLOPPY FEW INCHES OF WET SNOW LOOKS POSSIBLE INTO THURSDAY MORNING. EXPECT CLOUDY...COOL CONDITIONS ON FRIDAY WITH SOME LINGERING FLURRIES. UPPER TROUGH AND SURGE OF COLD AIR...85H TEMPS OF -20 TO -25C...WILL DROP OUT OF CANADA ACROSS LAKE SUPERIOR LATER NEXT WEEKEND WITH SOME NORTHWESTERLY WIND LAKE EFFECT SNOW SHOWERS ON SUNDAY. OVERALL TREND IN THE MODELS HOWEVER SEEMS TO BE DIMINISHING THE HARSHNESS OF THE COLD SURGE AND OFFERING MORE OF A BRIEF GLANCING BLOW WITH WARM ADVECTION RETURNING BY MONDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 136 AM EDT MON MAR 28 2016 DRYING FROM WEST HAS ALLOWED CONDITIONS TO IMPROVE TO VFR AT KIWD BUT THERE MAY BE SOME REDEVELOPMENT OF MVFR/IFR STRATUS OVERNIGHT IN WEAK NORTHERLY UPSLOPE FLOW. EXPECT CONDITIONS AT KCMX TO IMPROVE FROM VLIFR TO AT LEAST IFR OR MVFR OVERNIGHT WITH DRIER AIR ADVECTING IN THE NORTH. CONDITIONS WILL BE SLOWER TO IMPROVE AT KSAW ALTHOUGH EVEN THERE EXPECT IMPROVEMENT TO IFR LATE TONIGHT AS DZ/FZDZ ENDS. AS DRIER AIR CONTINUES TO MAKE INROADS...ALL TERMINALS WILL IMPROVE TO VFR MON MORNING/EARLY AFTN. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 417 PM EDT SUN MAR 27 2016 WITH LOW PRES TRACKING THRU THE LOWER GREAT LAKES REGION TONIGHT AND MON MORNING...15-25KT WINDS ARE EXPECTED OVER THE E HALF OF LAKE SUPERIOR LATE TONIGHT AND MON. CLOSER TO AN APPROACHING HIGH PRES RIDGE...WINDS WILL BE LIGHTER OVER WRN LAKE SUPERIOR. LIGHT WINDS...MOSTLY UNDER 15KT...WILL THEN BECOME THE RULE ACROSS THE LAKE MON NIGHT THRU AT LEAST TUE MORNING AS HIGH PRES RIDGE PASSES. SE TO S WINDS WILL THEN BE ON THE INCREASE LATER TUE THRU WED AHEAD OF AN APPROACHING COLD FRONT. TYPICAL FOR THIS TYPE OF FLOW... STRONGEST WINDS WILL LIKELY BE OVER ERN LAKE SUPERIOR...PROBABLY TO 20-30KT. AS THE COLD FRONT PASSES WED NIGHT AND A LOW PRES WAVE TRACKS LONG THE FRONT...WINDS WILL SHIFT TO THE NE AND N IN THE 20- 30KT RANGE. WINDS MAY GUST TO GALE FORCE FOR AT LEAST A PART OF THU/THU EVENING...DEPENDING ON THE STRENGTH OF THE LOW PRES WAVE. WINDS WILL DIMINISH A LITTLE ON FRI BEFORE A STRONG ARCTIC COLD FRONT PASSES EARLY SAT...USHERING IN A PERIOD OF GALES DURING THE DAY SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...MZ AVIATION...07/JV MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1050 PM CDT SUN MAR 27 2016 .UPDATE...FRONTAL BOUNDARY IS MOVING A LITTLE SLOWER THEN EXPECTED. SO WITH A DAMP GROUND AND LIGHT WINDS AHEAD OF THE FRONT SOME PATCHY FOG HAS DEVELOP. SO HAVE ADDED THE PATCHY FOG AHEAD OF THE MOVING FRONT ACROSS THE NORTHWEST. AS THE BOUNDARY MOVES THROUGH THE REGION EXPECT THE PATCHY FOG TO DECREASE FROM THE NORTHWEST AS WINDS SWITCH AROUND TO A NORTHERLY DIRECTION WITH SOME BRIEF LIGHT GUSTS. WILL KEEP THE PATCHY FOG AROUND IN THE PINEBELT REGION FOR THE REST OF THE NIGHT INTO EARLY MONDAY./17/ 924 PM CDT SUN MAR 27 2016 .DISCUSSION...THE BOUNDARY WAS MOVING THROUGH THE CWA...WITH A LINE OF SHOWERS EXTENDING FROM NORTH MISSISSIPPI INTO THE NORTHERN ZONES. UPDATED THE FORECAST TO ADJUST THE POPS. THE HI RES MODELS SUGGESTED THE RAIN ALONG THE COLD FRONT WOULD REMAIN ACROSS THE NORTH AND DIMINISH AS IT MOVED EAST. THE MODEL SEEMS TO HAVE A GOOD HANDLE ON IT. LEFT CHANCE POPS ALONG THE HIGHWAY 82 CORRIDOR AND SOME SLIGHT CHANCE VALUES JUST TO THE SOUTH. UPDATED ZONES WERE OUT...BUT MAY DO ANOTHER UPDATE TO REMOVE THE RAIN. ACTIVITY WAS ALREADY STRUGGLING. COOLER AIR WAS MOVING ACROSS ARKANSAS...WENT WITH THE RUC IN THE SHORT TERM TO CAPTURE THE FALLING TEMPS THROUGH THE NIGHT. WAS NOT TOTALLY CONVINCED TEMPS WOULD FALL INTO THE MID 40S BY MORNING...BUT VALUES NEAR 50 WERE NOT TOO FAR. TWEAKED THE HOURLY VALUES...BUT MAINTAINED OVERNIGHT LOWS. NO OTHER CHANGES. && .AVIATION...A FEW SHOWERS AND MAYBE A STRAY STORM WILL BE POSSIBLE THROUGH THIS EVENING AT GLH/GWO/GTR/CBM AS A COLD FRONT PUSHES INTO THE REGION...BUT A MAJOR IMPACT TO OPERATIONS IS NOT ANTICIPATED. THIS COLD FRONT WILL TAKE UNTIL THE EARLY MORNING HOURS TOMORROW TO CLEAR PORTIONS OF SE MS AND THEREFORE SOME IFR TO LIFR CONDITIONS DUE TO A COMBO OF LOW CEILINGS AND FOG WILL BE POSSIBLE AT MEI/NMM/PIB/HBG (ESPECIALLY AT HBG/PIB) THROUGH THE OVERNIGHT. ELSEWHERE EXPECT GENERALLY MVFR CONDITIONS AT WORST...IMPROVING BEFORE DAYBREAK...ALTHOUGH A FEW LOW CEILINGS COULD HANG ON AROUND GTR/CBM THROUGH MID MORNING TOMORROW. IN ADDITION...EXPECT A S/SW TO NW/N WIND SHIFT BEHIND THE FRONT THROUGH TOMORROW ALTHOUGH WIND SPEEDS SHOULD GENERALLY REMAIN LESS THAN 20 MPH. /BB/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 48 69 43 77 / 10 0 0 3 MERIDIAN 52 69 40 75 / 10 0 0 2 VICKSBURG 48 67 43 77 / 10 0 0 4 HATTIESBURG 57 73 47 77 / 10 0 0 5 NATCHEZ 51 67 47 77 / 10 0 0 8 GREENVILLE 44 64 43 72 / 37 0 0 3 GREENWOOD 44 66 42 74 / 48 0 0 2 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ JAN/JAN/ Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 929 PM CDT TUE MAR 29 2016 .UPDATE... Issued at 923 PM CDT TUE MAR 29 2016 Stripped away overnight PoPs. Made some adjustments to tomorrow`s PoPs and scaling back some in the afternoon. Positive tilted systems tend to be slower with their eastward push once convection develops. Noticed the 00z NAM is a bit further west with its initial development than the 12z and 18z model runs. Thinking the overnight shift may need to slow down the arrival of convection and push most of it into Wednesday night. && .DISCUSSION... Issued at 410 PM CDT TUE MAR 29 2016 Strong surface pressure gradient currently set up across mainly the western half of the forecast area as a surface low pressure system forms over the Central High Plains. This tight gradient has allowed for southerly winds to be gusty, around 20 to 30 mph. Better than anticipated mixing has cause RH values to drop to around 25 to 30 percent, which in combination with the gusty winds have brought marginal fire weather conditions, but overall not expecting any Red Flag conditions for the rest of the evening. Mid level ridging aloft has provided enough subsidence to bring fair conditions which has allowed temperatures to rise into the upper 60s to lower 70s across the area. West of this mid level ridging a closed low currently spins over the Great Basin, and will continue to inch closer to the area during the overnight hours. That trough, along with its attendant surface features will set the stage for a round of thunderstorms, some severe, for Wednesday afternoon/evening. Currently conditions over the forecast area are rather dry. As mentioned above, dew points are in the lower 30 degree range, which means any moisture advection into the area will have to overcome all that dry air. The 50 degree isodrosotherm is near Woodward, OK, arcing southeastward toward NE Texas. So, while the moisture sure has a long way to go the stout low level winds, pushing 40 to 50 kts should aid in that transport north. Surface winds should remain gusty through the overnight hours as the surface pressure gradient remains rather tight, and despite an inversion just off the surface some of those low level winds should still mix down occasionally, keeping surface winds between 20 and perhaps 30 mph through the overnight hours. As the moisture starts to stream into the area clouds will develop, and will likely form a stratus deck by early Wednesday morning, with ceilings around 2000 to 3000 feet. The question then becomes how much the area can destabilize through the day before storms fire in central/eastern Kansas. Throughout the day though, before the surface completely mixes out there could be a few isolated to scattered elevated thunderstorms. MUCAPE through the overnight hours over the inversion is likely only going to reach a few hundred J/kg of instability so while these storms shouldn`t be severe, there could be a few isolated hailers during the early to mid morning hours. By mid day, models have plenty of moisture over the forecast area to generate 1000 to 1500 J/kg of ML CAPE, across eastern Kansas and western Missouri. The trigger point for any storm formation will likely be dictated by the location of the tight dryline, which should form somewhere between KSLN and KTOP during the afternoon hours. GFS is a little more progressive with the position of the dryline, and places it more in the KC metro vicinity, but will for now side with the NAM, which places it generally parallel to I-335 out of Topeka. Helping with storm development will be the aforementioned trough, which will swing westward by this time providing good SW flow aloft, which will combine with the S/SE low level winds within the moist/warm sector to help with directional and speed shear. The result of the instability, shear, and forcing should be a line of strong storms, possibly in the form of supercells, forming just west of a TOP/EMP line and moving northeast rather speedily, impacting our eastern Kansas and far western Missouri counties shortly after sunset. Initial storm mode could be in the form of supercells, but by the time these storms get east of KC metro it could become a line of storms with perhaps a QLCS tornado threat into the evening and overnight hours. KC metro lies generally within the transition zone between initial supercells and QLCS mode, which makes narrowing down the individual hazards a little difficult. That being said, the most likely hazard will be wind, with hail a close second, then perhaps a few tornadoes. The area with the best chance to see a tornado or two will be across the western half of the CWA, with the eastern half likely seeing more of a linear mode with wind and perhaps QLCS tornado through the overnight hours. After thunderstorms clear out on Wednesday night light rain should continue across northern Missouri behind the departing system. Then on Thursday night into Friday morning another weak system with little moisture to work with should dive southeast through the area. This system will bring another chance for some light rain, and perhaps an outside chance at a light rain/snow mix for northern Missouri. Thereafter, expect fair weather with normal or above normal temperatures through the weekend and into early next week. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 640 PM CDT TUE MAR 29 2016 Extensive multi-layered VFR cloud cover will overspread the region this evening. Strong and gusty southeast to south winds up through 5k ft agl will draw low level moisture quickly northward with ceilings lowering to MVFR category by the pre-dawn hours. Ceilings should improve to VFR by early afternoon. Isolated light showers will be possible across northern and west central MO during the daylight hours. By late afternoon severe convection expected to form over northeast and east central KS and possibly far northwest MO. These individual storms are expected to for a line of strong/severe thunderstorms that will move across northern and west central MO just after this forecast period. && .EAX Watches/Warnings/Advisories... KS...None. MO...None. && $$ UPDATE...MJ DISCUSSION...Leighton AVIATION...MJ
Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 929 PM CDT TUE MAR 29 2016 .UPDATE... Issued at 923 PM CDT TUE MAR 29 2016 Stripped away overnight PoPs. Made some adjustments to tomorrow`s PoPs and scaling back some in the afternoon. Positive tilted systems tend to be slower with their eastward push once convection develops. Noticed the 00z NAM is a bit further west with its initial development than the 12z and 18z model runs. Thinking the overnight shift may need to slow down the arrival of convection and push most of it into Wednesday night. && .DISCUSSION... Issued at 410 PM CDT TUE MAR 29 2016 Strong surface pressure gradient currently set up across mainly the western half of the forecast area as a surface low pressure system forms over the Central High Plains. This tight gradient has allowed for southerly winds to be gusty, around 20 to 30 mph. Better than anticipated mixing has cause RH values to drop to around 25 to 30 percent, which in combination with the gusty winds have brought marginal fire weather conditions, but overall not expecting any Red Flag conditions for the rest of the evening. Mid level ridging aloft has provided enough subsidence to bring fair conditions which has allowed temperatures to rise into the upper 60s to lower 70s across the area. West of this mid level ridging a closed low currently spins over the Great Basin, and will continue to inch closer to the area during the overnight hours. That trough, along with its attendant surface features will set the stage for a round of thunderstorms, some severe, for Wednesday afternoon/evening. Currently conditions over the forecast area are rather dry. As mentioned above, dew points are in the lower 30 degree range, which means any moisture advection into the area will have to overcome all that dry air. The 50 degree isodrosotherm is near Woodward, OK, arcing southeastward toward NE Texas. So, while the moisture sure has a long way to go the stout low level winds, pushing 40 to 50 kts should aid in that transport north. Surface winds should remain gusty through the overnight hours as the surface pressure gradient remains rather tight, and despite an inversion just off the surface some of those low level winds should still mix down occasionally, keeping surface winds between 20 and perhaps 30 mph through the overnight hours. As the moisture starts to stream into the area clouds will develop, and will likely form a stratus deck by early Wednesday morning, with ceilings around 2000 to 3000 feet. The question then becomes how much the area can destabilize through the day before storms fire in central/eastern Kansas. Throughout the day though, before the surface completely mixes out there could be a few isolated to scattered elevated thunderstorms. MUCAPE through the overnight hours over the inversion is likely only going to reach a few hundred J/kg of instability so while these storms shouldn`t be severe, there could be a few isolated hailers during the early to mid morning hours. By mid day, models have plenty of moisture over the forecast area to generate 1000 to 1500 J/kg of ML CAPE, across eastern Kansas and western Missouri. The trigger point for any storm formation will likely be dictated by the location of the tight dryline, which should form somewhere between KSLN and KTOP during the afternoon hours. GFS is a little more progressive with the position of the dryline, and places it more in the KC metro vicinity, but will for now side with the NAM, which places it generally parallel to I-335 out of Topeka. Helping with storm development will be the aforementioned trough, which will swing westward by this time providing good SW flow aloft, which will combine with the S/SE low level winds within the moist/warm sector to help with directional and speed shear. The result of the instability, shear, and forcing should be a line of strong storms, possibly in the form of supercells, forming just west of a TOP/EMP line and moving northeast rather speedily, impacting our eastern Kansas and far western Missouri counties shortly after sunset. Initial storm mode could be in the form of supercells, but by the time these storms get east of KC metro it could become a line of storms with perhaps a QLCS tornado threat into the evening and overnight hours. KC metro lies generally within the transition zone between initial supercells and QLCS mode, which makes narrowing down the individual hazards a little difficult. That being said, the most likely hazard will be wind, with hail a close second, then perhaps a few tornadoes. The area with the best chance to see a tornado or two will be across the western half of the CWA, with the eastern half likely seeing more of a linear mode with wind and perhaps QLCS tornado through the overnight hours. After thunderstorms clear out on Wednesday night light rain should continue across northern Missouri behind the departing system. Then on Thursday night into Friday morning another weak system with little moisture to work with should dive southeast through the area. This system will bring another chance for some light rain, and perhaps an outside chance at a light rain/snow mix for northern Missouri. Thereafter, expect fair weather with normal or above normal temperatures through the weekend and into early next week. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 640 PM CDT TUE MAR 29 2016 Extensive multi-layered VFR cloud cover will overspread the region this evening. Strong and gusty southeast to south winds up through 5k ft agl will draw low level moisture quickly northward with ceilings lowering to MVFR category by the pre-dawn hours. Ceilings should improve to VFR by early afternoon. Isolated light showers will be possible across northern and west central MO during the daylight hours. By late afternoon severe convection expected to form over northeast and east central KS and possibly far northwest MO. These individual storms are expected to for a line of strong/severe thunderstorms that will move across northern and west central MO just after this forecast period. && .EAX Watches/Warnings/Advisories... KS...None. MO...None. && $$ UPDATE...MJ DISCUSSION...Leighton AVIATION...MJ
Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 929 PM CDT TUE MAR 29 2016 .UPDATE... Issued at 923 PM CDT TUE MAR 29 2016 Stripped away overnight PoPs. Made some adjustments to tomorrow`s PoPs and scaling back some in the afternoon. Positive tilted systems tend to be slower with their eastward push once convection develops. Noticed the 00z NAM is a bit further west with its initial development than the 12z and 18z model runs. Thinking the overnight shift may need to slow down the arrival of convection and push most of it into Wednesday night. && .DISCUSSION... Issued at 410 PM CDT TUE MAR 29 2016 Strong surface pressure gradient currently set up across mainly the western half of the forecast area as a surface low pressure system forms over the Central High Plains. This tight gradient has allowed for southerly winds to be gusty, around 20 to 30 mph. Better than anticipated mixing has cause RH values to drop to around 25 to 30 percent, which in combination with the gusty winds have brought marginal fire weather conditions, but overall not expecting any Red Flag conditions for the rest of the evening. Mid level ridging aloft has provided enough subsidence to bring fair conditions which has allowed temperatures to rise into the upper 60s to lower 70s across the area. West of this mid level ridging a closed low currently spins over the Great Basin, and will continue to inch closer to the area during the overnight hours. That trough, along with its attendant surface features will set the stage for a round of thunderstorms, some severe, for Wednesday afternoon/evening. Currently conditions over the forecast area are rather dry. As mentioned above, dew points are in the lower 30 degree range, which means any moisture advection into the area will have to overcome all that dry air. The 50 degree isodrosotherm is near Woodward, OK, arcing southeastward toward NE Texas. So, while the moisture sure has a long way to go the stout low level winds, pushing 40 to 50 kts should aid in that transport north. Surface winds should remain gusty through the overnight hours as the surface pressure gradient remains rather tight, and despite an inversion just off the surface some of those low level winds should still mix down occasionally, keeping surface winds between 20 and perhaps 30 mph through the overnight hours. As the moisture starts to stream into the area clouds will develop, and will likely form a stratus deck by early Wednesday morning, with ceilings around 2000 to 3000 feet. The question then becomes how much the area can destabilize through the day before storms fire in central/eastern Kansas. Throughout the day though, before the surface completely mixes out there could be a few isolated to scattered elevated thunderstorms. MUCAPE through the overnight hours over the inversion is likely only going to reach a few hundred J/kg of instability so while these storms shouldn`t be severe, there could be a few isolated hailers during the early to mid morning hours. By mid day, models have plenty of moisture over the forecast area to generate 1000 to 1500 J/kg of ML CAPE, across eastern Kansas and western Missouri. The trigger point for any storm formation will likely be dictated by the location of the tight dryline, which should form somewhere between KSLN and KTOP during the afternoon hours. GFS is a little more progressive with the position of the dryline, and places it more in the KC metro vicinity, but will for now side with the NAM, which places it generally parallel to I-335 out of Topeka. Helping with storm development will be the aforementioned trough, which will swing westward by this time providing good SW flow aloft, which will combine with the S/SE low level winds within the moist/warm sector to help with directional and speed shear. The result of the instability, shear, and forcing should be a line of strong storms, possibly in the form of supercells, forming just west of a TOP/EMP line and moving northeast rather speedily, impacting our eastern Kansas and far western Missouri counties shortly after sunset. Initial storm mode could be in the form of supercells, but by the time these storms get east of KC metro it could become a line of storms with perhaps a QLCS tornado threat into the evening and overnight hours. KC metro lies generally within the transition zone between initial supercells and QLCS mode, which makes narrowing down the individual hazards a little difficult. That being said, the most likely hazard will be wind, with hail a close second, then perhaps a few tornadoes. The area with the best chance to see a tornado or two will be across the western half of the CWA, with the eastern half likely seeing more of a linear mode with wind and perhaps QLCS tornado through the overnight hours. After thunderstorms clear out on Wednesday night light rain should continue across northern Missouri behind the departing system. Then on Thursday night into Friday morning another weak system with little moisture to work with should dive southeast through the area. This system will bring another chance for some light rain, and perhaps an outside chance at a light rain/snow mix for northern Missouri. Thereafter, expect fair weather with normal or above normal temperatures through the weekend and into early next week. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 640 PM CDT TUE MAR 29 2016 Extensive multi-layered VFR cloud cover will overspread the region this evening. Strong and gusty southeast to south winds up through 5k ft agl will draw low level moisture quickly northward with ceilings lowering to MVFR category by the pre-dawn hours. Ceilings should improve to VFR by early afternoon. Isolated light showers will be possible across northern and west central MO during the daylight hours. By late afternoon severe convection expected to form over northeast and east central KS and possibly far northwest MO. These individual storms are expected to for a line of strong/severe thunderstorms that will move across northern and west central MO just after this forecast period. && .EAX Watches/Warnings/Advisories... KS...None. MO...None. && $$ UPDATE...MJ DISCUSSION...Leighton AVIATION...MJ
  [top] Area Forecast Discussion...Updated National Weather Service Saint Louis MO 920 PM CDT TUE MAR 29 2016 .UPDATE... Issued at 910 PM CDT Tue Mar 29 2016 Looking at the latest NAM model run and HRRR model it appears that showers will likely hold off until after 12Z Wednesday morning for our forecast area. Warmer low temperatures can be expected tonight, especially over central MO due to increasing cloudiness, increasing south-southwesterly low level winds and possibly also increasing southeasterly surface winds as a strong south-southwesterly low level jet translates into northwest MO by 12Z Wednesday, surface dew points slowly rising, and low-mid level warm air advection with rising 850 mb temperatures. GKS && .SHORT TERM... (Through Late Tonight) Issued at 341 PM CDT Tue Mar 29 2016 Sfc ridge continues to builds ewd out of the region tonight allowing winds to veer to become sely to ssely tonight. Mdls suggest a swly LLJ will pick up late tonight. This will spread clouds into the area, but also shud be the focus for isod to perhaps sct TSRA late tonight into Wed morning. The primary area impacted would be central and nern MO. However, latest guidance continues to increase doubt as to where and when TSRA will develop. Continued a warm trend for tonight across the wrn half of the CWA. This area will see clouds develop/move into the region this evening and persist overnight. Trended slightly cooler further E where less clouds will be seen. However, even across this area, mixing will continue thru the night which shud help keep temps up. Tilly .LONG TERM... (Wednesday through Next Tuesday) Issued at 341 PM CDT Tue Mar 29 2016 (Wednesday through Friday) Still appears that there will be widespread moisture convergence develop across the area during the day on Wednesday as the area will lie within the axis of a 50kt low level jet. This will also be under increasing ascent ahead of the mid level trough and steepening mid level lapse rates. Expect there to be scattered showers and thunderstorms developing during the morning with the storms becoming more numerous during the afternoon and evening hours as NAM/GFS/ECMWF all show elongated vorticty moving across the area which will maximize ascent. Instability will be increasing because of the steepening lapse rates and the moisture transport, and so with the deep shear, a few severe storm capable of producing large hail and damaging winds will be possible. Rain will push mainly into the eastern part of the CWA by overnight Thursday night as the dry slot works into the area. Cold front will move across the area on Thursday. Temperatures will still be able to warm above normal ahead of the front before it moves through. Second upper trough will move across the area Thursday night into Friday bringing a chance of showers to mainly the northern half of the area. Temperatures will fall back below normal on Friday. (Saturday through Tuesday) Not much change in thinking in the extended part of the forecast. Both the ECMWF and GFS are still showing the northwesterly flow aloft becoming more zonal by early next week. This will happen as an upper trough digs down out of Canada and moves across the Upper Midwest and Great Lakes on Monday. This will cause a cold front to move across the area during the day on Monday. Both models are showing enough moisture and some QPF along the front to support a slight chance of showers on Monday. Temperatures still appear that they will climb to near normal Saturday through Monday ahead of the front before colder air moves in on Tuesday. Britt && .AVIATION... (For the 00z TAFs through 00z Wednesday Evening) Issued at 651 PM CDT Tue Mar 29 2016 VFR flight conditions are expected tonight. A southerly low level jet will ramp-up late this evening into the overnight hours. The core of the LLJ will be centered near 2,500 ft, however the lower portion will extend a good amount into the lower troposphere such that LLWS conditions are expected. Showers and thunderstorms are expected to increase in coverage Wednesday morning/aftenoon in response to lift via the LLJ, and have now included a mention of SHRA/TSRA along with flight conditions lowering into the MVFR category. The highest probability of both showers and thunderstorms appears to be focused across the southeast third of MO into southern IL including the St. Louis area terminals. Specifics for KSTL: VFR flight conditions are expected tonight. A southerly low level jet will ramp-up late this evening into the overnight hours resulting in a window of LLWS conditions from 09-15z. Showers and thunderstorms are expected to increase in coverage Wednesday morning/aftenoon in response to lift via the LLJ, and have now included a mention of SHRA/TSRA along with flight conditions lowering into the MVFR category. The new TAF has the brunt of the adverse weather starting at 18z, however would not be suprised if it actually began slightly earlier. Glass && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
744 PM CDT TUE MAR 29 2016 .SYNOPSIS... ISSUED AT 322 PM CDT TUE MAR 29 2016 H5 ANALYSIS THIS MORNING HAS A CLOSED LOW ALONG THE UTAH AND NEVADA BORDER. 100 METER HT FALLS WERE NOTED ACROSS SRN CALIFORNIA INTO NRN AZ AND A 90 KT H5 JET STREAK EXTENDED FROM SAN DIEGO...TO FLAGSTAFF AZ. UPSTREAM OF THE LOW...RIDGING WAS PRESENT FROM THE OZARKS NWD INTO NRN MINNESOTA...WHILE A TROUGH OF LOW PRESSURE WAS PRESENT OVER THE CANADIAN MARITIMES AND NEW ENGLAND. CLOSER TO WESTERN AND NORTH CENTRAL NEBRASKA...A WEAK SHORTWAVE WAS NOTED OVER SWRN NEBRASKA. THIS ALONG WITH SOME ELEVATED WARM AIR ADVECTION...LED TO THUNDERSTORMS EARLIER THIS MORNING ACROSS THE SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA. THIS ACTIVITY HAS SINCE PUSHED EAST OF THE AREA. IN ITS WAKE...ABUNDANT HIGH LEVEL CLOUDS CONTINUE TO STREAM INTO THE AREA FROM THE SOUTHWEST. AT THE SURFACE...LOW PRESSURE WAS PRESENT OVER EASTERN COLORADO WITH AN INVERTED SURFACE TROUGH EXTENDING NWD INTO THE CENTRAL PANHANDLE OF NEBRASKA. EAST OF THIS LOW AND INVERTED SURFACE TROUGH...WINDS WERE FROM THE SOUTH OR SOUTHEAST ACROSS WESTERN AND NORTH CENTRAL NEBRASKA THIS AFTERNOON AND GUSTY. LOW LEVEL MOISTURE CONTINUES TO STREAM INTO SOUTHWESTERN NEBRASKA THIS AFTERNOON AS DEW POINTS ARE NOW IN THE LOWER 40S ACROSS SWRN NEBRASKA. TEMPERATURES AS OF 3 PM CDT RANGED FROM 54 AT ONEILL TO 65 AT NORTH PLATTE AND IMPERIAL. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 322 PM CDT TUE MAR 29 2016 TONIGHT AND WEDNESDAY...IN THE TONIGHT PERIOD...THE MAIN CHALLENGE IS PRECIPITATION AND THUNDERSTORM CHANCES FOR MAINLY WESTERN PORTIONS OF THE FORECAST AREA. LATER THIS AFTERNOON THROUGH EARLY EVENING...THE LATEST NAM12...GFS AND HRRR SOLNS INITIATE CONVECTION ALONG THE NEBR/CO BORDER AROUND 23Z THIS EVENING...LIFTING THIS NORTH NORTHEAST INTO THE WESTERN SANDHILLS AND NWRN NEBRASKA THIS EVENING. GOOD DEEP LAYER SHEAR IS NOTED TONIGHT WITH 40 TO 60 KTS NOTED. HOWEVER MEAGER CAPES OF 500 TO 1000 J/KG EXIST...SO THE SEVERE THREAT SHOULD BE FAIRLY MARGINAL THIS EVENING. HOWEVER CANNOT RULE OUT A STRONG STORM OR TWO GIVEN THE STRONG APPROACHING LOW AND DYNAMICS ALOFT. WILL CONTINUE TO MENTION A STRONG TS THREAT GENERALLY WEST OF A NORTH PLATTE TO VALENTINE LINE. OVERNIGHT...MORE WIDESPREAD PCPN WILL DEVELOP OVER NORTHERN AND NORTHWESTERN PORTIONS OF THE FORECAST AREA. THIS IS IN THE VICINITY OF A H7 FRONT WHICH IS ANCHORED ALONG THE SD/NEBR BORDER. ELEVATED INSTABILITY CONTINUES OVERNIGHT AS WELL ACROSS THE ENTIRE FORECAST AREA AS H800 LI/S REMAIN NEGATIVE ACROSS THE NRN 2/3RDS OF THE FORECAST AREA. WITH THIS IN MIND...I KEPT IN A MENTION OF THUNDER FROM THE INHERITED FCST. SHIFTING INTO WEDNESDAY...RAIN WILL CONTINUE ACROSS NORTHERN NEBRASKA DURING THE EARLY MORNING HOURS. AS THE H5 LOW TRACKS OUT OF THE PANHANDLE INTO WEST CENTRAL NEBRASKA WEDS AM...AIR WILL COOL DOWN ENOUGH TO SUPPORT SNOW IN THE NORTHWESTERN CWA DURING THE LATE MORNING HOURS. A NICE AREA OF DEFORMATION PRECIPITATION WILL DEVELOP WEDS ON THE NORTHERN PERIPHERY OF THE LOW AS IT TRACKS FROM WESTERN NEBRASKA INTO EASTERN NEBRASKA. AS THIS FEATURE TRACKS EAST..IT OPENS UP AS IT INCREASES ITS FORWARD SPEED ACROSS CENTRAL AND EASTERN NEBRASKA. THIS WILL MAKE FOR A FAIRLY TIGHT WINDOW FOR CONDS FAVORABLE FOR SNOW. THIS WINDOW HAS BECOME SMALLER WITH THIS MORNINGS MODEL RUNS AS H85 TEMPS ARE NOW RUNNING 1-2C WARMER COMPARED TO YESTERDAY/S RUNS. THAT BEING SAID...WITH THE CURRENT TEMPERATURE PROFILE IN THE NORTHWEST...WE ARE LOOKING AT A 3-6 HR WINDOW WHICH IS FAVORABLE FOR SNOW. ATTM THAT IS APPROXIMATELY FROM 15 TO 21Z WEDS. WITH THIS IN MIND...CUT BACK SNOW ACCUMS IN THE NORTHWEST AND NOW HAVE 3 TO 5 INCHES IN SHERIDAN AND NORTHWESTERN CHERRY COUNTIES. WILL HOIST A WINTER WEATHER ADVISORY FOR WEDS AND CANCEL THE WINTER STORM WATCH WITH THE AFTERNOON PACKAGE. FURTHER EAST...THE THREAT FOR SEVERE STORMS IS STILL EXPECTED TO BE EAST OF THE FORECAST AREA WEDS AFTN AND EVE AS THE MODELS CONTINUE TO FORCE THE DRYLINE THROUGH THE FORECAST AREA WEDS AM. THE ONLY AREA OF CONCERN FOR A STRONG STORM MAY LIE IN THE FAR NERN CWA WHICH MAY END UP INVOF OF A WARM FRONT WEDS AFTN. THIS IS MORE FAVORED WITH THE GFS SOLN AS THE NAM12 HAS THIS FRONT SE OF THE AREA BY 21Z. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 322 PM CDT TUE MAR 29 2016 00Z THURSDAY AND BEYOND. THE UPPER LEVEL TROUGH WILL CONTINUE TO SWING THROUGH THE CWA LATE WEDNESDAY AFTERNOON...WITH THE TROUGH AXIS EAST OF THE FORECAST AREA BY 06Z THURSDAY. Q-VECTOR DIVERGENCE AND RESULTANT FRONTOLYSIS WILL BE UNDERWAY SHORTLY AFTER 00Z...WITH MOST LOCATIONS SEEING A MARKED DECREASE IN INTENSITY WELL BEFORE 06Z. THE DECREASE IN QPF HOWEVER WILL BE SHORT-LIVED AS THE NEXT SHORTWAVE AND ULJ DIVE SOUTH FROM WEST CENTRAL CANADA. THE TROPOSPHERE IS SHOWN TO BE SUFFICIENTLY SATURATED FOR AN ADDITIONAL ROUND OF QPF BEGINNING LATE MORNING ON THURSDAY. THE HEAVIEST QPF IS SHOWN ACROSS NORTHEASTERN AND NORTH CENTRAL PORTIONS OF THE FORECAST AREA WHERE OMEGA IS MAXIMIZED DURING THE EARLY AFTERNOON THURSDAY. TEMPERATURES SUPPORT RAIN OVER SNOW...BUT WILL CONTINUE A RAIN/SNOW MIX BEFORE 18Z AND AFTER 00Z AS TEMPERATURES WILL COOL WITH THE DIURNAL TREND. ANY ACCUMULATIONS OF SNOW WILL BE LIGHT. DUE TO RAPID COOLING ALOFT WITH THE SYSTEM...WEAK ELEVATED INSTABILITY IS SHOWN IN THE VARIOUS SOLUTIONS...THUS SHOWERS ARE PREFERRED...BUT A RUMBLE OR TWO OF THUNDER CANNOT BE RULED OUT. THE CLIPPER LIKE SYSTEM RAPIDLY ADVANCES EAST THURSDAY NIGHT INTO FRIDAY WITH QPF ENDING FROM NORTHWEST TO SOUTHEAST. BEYOND EARLY FRIDAY MORNING THE FORECAST TURNS DRY WITH A STARK WARMING TREND. THIS IS DUE TO THE DEVELOPMENT OF AMPLIFIED RIDGE OVER THE WESTERN STATES. THE RIDGE WILL EVENTUALLY BREAK DOWN AT DAY 7 OR BEYOND...THE BREAKDOWN WILL NEED TO BE MONITORED FOR POTENTIAL FIRE WX CONCERNS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 744 PM CDT TUE MAR 29 2016 THE THUNDERSTORM COMPLEX ACROSS WRN NEB LIFTS NORTHEAST THIS EVENING AND EXITS THE FCST AREA 04Z-06Z. MVFR CIGS SHOULD DEVELOP IN THE WAKE OF THIS DISTURBANCE AND LAST ALL OF WEDNESDAY IN SOME AREAS. A DRY SLOT OF VFR SHOULD LIFT INTO SWRN NEB TOWARD MORNING. SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE THROUGHOUT THE FCST AREA BUT MAINLY ACROSS NWRN NEB. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 7 AM CDT /6 AM MDT/ TO 7 PM CDT /6 PM MDT/ WEDNESDAY FOR NEZ004-094. && $$ SYNOPSIS...BUTTLER SHORT TERM...BUTTLER LONG TERM...JACOBS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
335 PM CDT MON MAR 28 2016 .SYNOPSIS... ISSUED AT 332 PM CDT MON MAR 28 2016 H5 HAND ANALYSIS THIS MORNING HAS A PROGRESSIVE PATTERN ACROSS THE CONUS. A TROUGH WAS PRESENT ACROSS THE EASTERN GREAT LAKES...SWD TO THE CAROLINAS. RIDGING WAS PRESENT ACROSS THE CENTRAL CONUS FROM WESTERN NEBRASKA...NORTH TO SOUTH CENTRAL CANADA. WEST OF THIS FEATURE...A CLOSED LOW WAS PRESENT ACROSS THE PANHANDLE OF IDAHO WITH A SECONDARY SHORTWAVE NOTED OVER FAR NORTHEASTERN CALIFORNIA. HT FALLS IN ASSOCIATION WITH THIS FEATURE WERE MOST PRONOUNCED AT RENO AND MEDFORD OREGON WHERE 100-120 METER FALLS WERE NOTED. FURTHER EAST...70-90 METER FALLS WERE NOTED AT ELKO NEVADA AND SALT LAKE CITY. AT THE SURFACE...HIGH PRESSURE WAS PRESENT ACROSS THE OZARKS WITH A DEVELOPING SURFACE TROUGH NOTED ALONG THE FRONT RANGES OF COLORADO...WYOMING...ALONG WITH THE WESTERN NEBRASKA PANHANDLE. SRLY WINDS HAVE INCREASED THIS AFTERNOON...WHICH HAS LED TO A DECENT SHOT OF WARM AIR ADVECTION AND TEMPERATURES IN THE MID TO UPPER 60S. SKIES WERE MAINLY CLEAR WITH THE EXCEPTION OF SOME INVADING HIGH CLOUDINESS CROSSING THE CENTRAL AND SRN ROCKIES IN ADVANCE OF THE SHORTWAVE TROUGH ACROSS THE WESTERN ROCKIES. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 332 PM CDT MON MAR 28 2016 MAIN FORECAST CHALLENGES THROUGH TUESDAY ARE TEMPERATURES AND PRECIPITATION. THE H5 RIDGE CONTINUES TO MOVE EAST ACROSS NEBRASKA... FOLLOWED BY A DEEPENING UPPER LOW AND DEVELOPING LEE SIDE SURFACE LOW. THIS EVENING AND TONIGHT... EXPECT WINDS TO STAY ELEVATED WITH THE SFC PRESSURE GRADIENT NOT RELAXING AND A LOW LEVEL JET DEVELOPING AFTER DARK. BOUNDARY LAYER WILL REMAIN WELL MIXED THROUGH EARLY EVENING AS MID LEVEL CLOUDS REMAIN WELL WEST OF THE AREA AND MOST MODELS SHOWING H85 WINDS NEAR 20-25KTS. AROUND 06Z... THE RAP IS THE STRONGEST WITH THE LLJ WITH SPEEDS APPROACHING 50KTS OVER THE SANDHILLS. MODEST MOISTURE ADVECTION WILL OCCUR LATER THIS EVENING WITH SOUTH/SOUTHEAST FLOW. DEW POINTS ARE ECLIPSING 30F IN FAR SOUTHERN NEBRASKA AND NORTHERN KANSAS AS OF 20Z. CONTINUED THE CHANCE OF THUNDER FOR AREAS ALONG/EAST OF HWY 83 OVERNIGHT... BUT PUSHED THE POPS BACK UNTIL AFTER 09Z. HRRR KEEPING THE AREA DRY THROUGH 08Z... AND SOME NCAR WRF MEMBERS SHOWING DEVELOPMENT TOWARD 09Z OVER SOUTHERN NEBRASKA. NAM FORECAST SOUNDINGS AT KLBF... KBBW...AND KONL SUPPORT AN ELEVATED SHOWER OR STORM WITH STEEP LAPSE RATES AND LIFT ABOVE THE INVERSION. NOT EXPECTING ANY SEVERE WEATHER WITH CAPE GENERALLY UNDER 500J/KG AND POSITIVE LIFTED INDEX... BUT LLJ WILL RESULT IN APPRECIABLE SHEAR. DUE TO INCREASED MOISTURE/CLOUD COVER... BREEZY CONDITIONS... AND H85 TEMPS HOVERING AROUND 9C... WENT WITH A MAV/MET BLEND OF MIN TEMPS OF UPPER 30S PANHANDLE AND NEAR 40 ELSEWHERE. TUESDAY... TRENDED MAX TEMPS TOWARD THE MAV DUE TO STRONG SOUTHERLY FLOW AHEAD OF THE DEVELOPING SFC LOW. GFS IS MOST AGGRESSIVE WITH THE H85 THERMAL RIDGE WITH TEMPS NEAR 20C AT KIML AND 13C AT KVTN... ECS A LITTLE FARTHER SOUTH WITH THERMAL AXIS... AND NAM SOUTHWEST OF THE AREA RESULTING IN 10C AT KIML AND 6C AT KVTN. HAVE COOLEST HIGHS NORTH CENTRAL DUE TO COOLER H85 TEMPS AND POSSIBLY SOME OF THE MORNING CONVECTION LASTING INTO EARLY AFTERNOON. STRONGER MID LEVEL FGEN FORCING ENTERS THE PANHANDLE AFTER 18Z... SO EXPANDED POPS FROM KIML TO KVTN. MENTIONED THUNDER WITH MUCAPE UP TO 1000J/KG... 0-6KM SHEAR NEAR 45KTS... AND LIFTED INDEX NEAR 0. NAM FORECAST SOUNDINGS AT KAIA AND KOGA SHOW SUFFICIENT LIFT IN THE LOWER AND MID LEVELS... AND IS CONSISTENT WITH ISENTROPIC UPGLIDE AT 295K AND 300K. MOISTURE ADVECTION ALSO CONTINUES WITH MIXING RATIOS NEARING 8G/KG AND DEW POINTS PASSING 45F BY 21Z. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 332 PM CDT MON MAR 28 2016 MID RANGE...TUESDAY NIGHT THROUGH THURSDAY...THE MAIN FORECAST CHALLENGE CONTINUES TO BE PRECIPITATION CHANCES AND THE THREAT FOR ACCUMULATING SNOW IN THE NORTHWESTERN SANDHILLS...AND NORTHEASTERN PANHANDLE OVERNIGHT TUESDAY NIGHT INTO WEDNESDAY. FOR TUESDAY EVENING...ABUNDANT LOW LEVEL MOISTURE WILL FLOW NORTH INTO THE FORECAST AREA WITH DEW POINTS REACHING THE UPPER 40S TO AROUND 50...BRIEFLY ALONG AND EAST OF A MERRIMAN TO OGALLALA LINE. BY MIDNIGHT...THE H5 LOW WILL BEGIN TO EXIT SERN WYOMING INTO THE NEBR PANHANDLE. ALONG AND EAST OF THE APPG LOW...ELEVATED INSTABILITY WILL INCREASE OVERNIGHT AS WELL AS MID LEVEL WAA AND LIFT. LIFT WILL WILL REMAIN STRONGEST ACROSS NORTHERN NEBRASKA INVOF OF THE H7 FRONT...SO WILL CONTINUE LIKELY MENTION OF POPS. WILL CONTINUE TO MENTION THUNDER TUESDAY NIGHT AS ELEVATED INSTABILITY CONTINUES TO BE NOTED PER NAM AND GFS FCST NEGATIVE H850 LIFTED INDICES. ON WEDNESDAY...THE UPPER LEVEL LOW WILL EMERGE EAST ENTERING THE WESTERN CWA...THEN EXITING THE EASTERN CWA TOWARD THE END OF THE DAY. THERE ARE STILL SOME DIFFERENCES WITH RESPECT TO COLD AIR ON THE BACK SIDE OF THE H5 LOW AND THIS TIES IN DIRECTLY TO SNOW POTENTIAL WEDNESDAY. THE GFS CONTINUES TO BE THE COLDEST SOLN...WITH THE ECMWF WARMEST AND THE NAM A COMPROMISE. ALSO...THE 12Z GFS...AND00Z ECMWF FROM LAST NIGHT...LIFT THE H5 LOW IN A NORTHEASTERLY DIRECTION...WHILE THE NAM LIFTS THIS MORE EAST. NATIONAL GUIDANCE FAVORS A BLEND OF THE 12Z GFS/00Z ECMWF SOLN WHICH WAS FAVORED. THIS SOLN GENERATES THE BULK OF ACCUMULATING SNOW ACROSS THE NERN PANHANDLE AND FAR NORTHWESTERN CHERRY COUNTY. UTILIZING A 8-1 SNOW TO WATER RATIO SINCE TEMPS HOVER IN THE LOWER 30S...YIELDS 3 TO 6 INCHES ACROSS NORTHERN SHERIDAN AND FAR NORTHWESTERN CHERRY COUNTY. WITH THIS IN MIND...DECIDED TO HOIST A WINTER STORM WATCH FOR SHERIDAN COUNTY FOR WEDNESDAY. FURTHER EAST...A LATER CHANGEOVER ACROSS NORTHERN NEBRASKA WILL FACILITATE SIGNIFICANTLY LOWER ACCUMS WITH AROUND 1 INCH TO 2 INCHES EXPECTED ALONG AND NORTH OF HIGHWAY 2. FURTHER SOUTH AND EAST...THUNDERSTORMS IN THE AFTERNOON...WILL GIVE WAY TO A COLD RAIN WEDS NIGHT. WITH RESPECT TO SEVERE POTENTIAL WEDS AFTERNOON...THE NAM12 REMAINS THE FARTHEST WEST WITH ITS DRYLINE WEDS AFTN AND BY 00Z THURSDAY...IS JUST OFF TO THE EAST OF THE CWA. THE NAM SOLN INITIATES CONVECTION ALONG A DRYLINE BULGE...JUST TO THE EAST OF WHEELER COUNTY LATE WEDS AFTN. SWRLY H5 WINDS WILL CARRY THIS AWAY FROM THE FORECAST AREA...SO NO SEVERE THREAT IS ANTICIPATED ATTM. THE THREAT FOR RAIN AND SNOW...WILL END OVERNIGHT IN THE CENTRAL AND EASTERN CWA WITH THE BEST CHANCES FOR LIGHT ACCUMULATIONS BEING IN THE NORTHERN CWA. IN THESE AREAS...1 TO 2 INCHES OF SNOW IS POSSIBLE. ON THURSDAY...A SECONDARY SHORTWAVE...WITH MUCH COLDER AIR ALOFT...WILL DROP SOUTH INTO NORTHERN AND EASTERN NEBRASKA. WITH SURFACE HEATING AND STEEP LAPSE RATES EXPECTED THURSDAY AFTERNOON...WE HAVE A GOOD THREAT FOR RAIN OR SNOW SHOWER DEVELOPMENT. THIS MENTION WAS CONTINUED WITH THE NEW FORECAST PACKAGE. AS FOR HIGHS THURSDAY...THEY WILL STRUGGLE TO GET OUT OF THE 40S AND WILL PROBABLY REMAIN IN THE UPPER 30S OVER NORTHERN NEBRASKA. THURSDAY NIGHT THROUGH MONDAY...ON FRIDAY...A SECONDARY ARCTIC FRONT WILL BACK INTO NORTHERN AND EASTERN NEBRASKA. H85 TEMPS WILL RANGE FROM 2C IN THE SOUTHWEST...TO -4C IN THE NORTHEASTERN CWA. HIGHS WILL RANGE FROM THE LOWER 40S IN THE NORTHEAST...TO AROUND 50 IN THE SOUTHWEST. ARCTIC AIR WILL PUSH INTO THE GREAT LAKES AND UPPER MIDWEST SATURDAY THROUGH MONDAY. ATTM...THE MODELS DO KEEP THIS AIR NORTHEAST OF THE AREA...SO HIGHS WILL BE IN THE 50S/60S THROUGH THE WEEKEND. LOCATIONS IN THE FAR NORTHEASTERN CWA MAY BE VULNERABLE TO THIS ARCTIC AIR BACKING IN FROM THE NORTHEAST...AND WILL HAVE TO CONTINUE TO MONITOR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1225 PM CDT MON MAR 28 2016 THE MAIN AVIATION WEATHER CONCERN THROUGH TUESDAY AFTERNOON IS WIND. GUSTY SOUTH/SOUTHEAST WINDS WILL CONTINUE THROUGH THIS EVENING...THEN TAPER A LITTLE OVERNIGHT. HOWEVER...A LOW LEVEL JET WILL SET UP AFTER SUNSET AND CREATE WIND SHEAR CONDITIONS OF UP TO A 30KT DIFFERENCE WITHIN 2KFT AGL. A FEW SHOWERS OR THUNDERSTORMS MAY DEVELOP AFTER MIDNIGHT...GENERALLY EAST OF A KVTN TO KLBF LINE. SOUTHEAST WINDS STRENGTHEN ONCE AGAIN LATE TUESDAY MORNING WITH GUSTS EXCEEDING 20KTS. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR NEZ004. && $$ SYNOPSIS...BUTTLER SHORT TERM...SNIVELY LONG TERM...BUTTLER AVIATION...SNIVELY
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
235 PM PDT MON MAR 28 2016 .SYNOPSIS...WIDESPREAD STRONG AND POTENTIALLY DAMAGING WINDS WILL PERSIST THIS EVENING BEFORE RELAXING LATE TONIGHT AS A STORM SYSTEM MOVES THROUGH THE AREA. WIDESPREAD BLOWING DUST IS LIKELY ALONG WITH A CHANCE OF SHOWERS MAINLY IN THE HIGHER TERRAIN NORTH AND EAST OF LAS VEGAS. COOL TEMPERATURES AND SHOWER CHANCES WILL LINGER MAINLY ACROSS THE SOUTHERN GREAT BASIN AND SIERRA THROUGH WEDNESDAY BEFORE A WARMING TREND COMMENCES LATE IN THE WEEK THROUGH THE WEEKEND. && .SHORT TERM... THROUGH WEDNESDAY NIGHT. ...MAJOR WIND EVENT STILL ON TRACK FOR THIS AFTERNOON/EVENING... A VERY WINDY EVENING IN STORE FOR MUCH OF THE AREA AS A POWERFUL STORM SYSTEM MOVES ACROSS THE GREAT BASIN. WINDS SO FAR HAVE BEEN SLOWLY CREEPING UPWARDS THROUGH THE DAY...AND LATEST WATER VAPOR IMAGERY INDICATES INCREASINGLY STRONG SUBSIDENCE MOVING TOWARDS THE REGION WHICH WILL ENHANCE DOWNSLOPING WIND POTENTIAL IN THE HOURS TO COME. IN ADDITION...FORECAST SOUNDINGS SUGGEST A STABLE LAYER ABOVE THE RIDGETOP LEVEL OF THE SPRING MOUNTAINS (~10K FT) WHICH WILL AID IN THE DEVELOPMENT OF A STRONG DOWNSLOPE WIND EVENT REACHING INTO THE WESTERN AND POSSIBLY CENTRAL LAS VEGAS VALLEY. THIS STORM SYSTEM BEARS SIMILARITY TO THE MARCH 6TH 2012 WIND EVENT WHEN THE WINDS TOPPED OUT AT 63 MPH AT MCCARRAN AND OVER 14,000 PEOPLE LOST POWER IN ADDITION TO SCATTERED WIND DAMAGE. WITH THIS EVENT...SIMILARLY STRONG WINDS CAN BE EXPECTED ACROSS MUCH OF THE MOJAVE DESERT IN EASTERN CALIFORNIA...SOUTHERN NEVADA...AND NORTHWEST ARIZONA. IN SUMMARY...PREPARE FOR *WIDESPREAD WIND GUSTS EXCEEDING 50 MPH *POCKETS OF DENSE BLOWING DUST AND LOW VISIBILITY *SPORADIC POWER OUTAGES *POSSIBLE WIND DAMAGE TO OUTDOOR STRUCTURES AND ROOFTOPS *FLIGHT DELAYS IN ADDITION TO THE WIND...THUNDERSTORMS HAVE BROKEN OUT ACROSS THE SOUTHERN GREAT BASIN FROM NEAR TONOPAH DOWN TOWARDS LIDA. THESE STORMS HAVE DEVELOPED ALONG THE COLD FRONT PUSHING SOUTH ACROSS THE AREA AND ISOLATED THUNDERSTORMS WILL REMAIN POSSIBLE ACROSS MUCH OF THE SOUTHERN GREAT BASIN THIS EVENING. A FEW SHOWERS AND STORMS MAY ALSO KICK OFF THIS EVENING ACROSS NORTHWEST ARIZONA. WINDS WILL GRADUALLY RELAX THIS EVENING AS THE COLD FRONT PUSHES ACROSS THE REGION AND PRESSURE GRADIENTS SLOWLY RELAX. TROUGH RESPONSIBLE FOR THE ACTIVE WEATHER TODAY WILL MOVE INTO THE EASTERN GREAT BASIN BY TUESDAY AFTERNOON AND LINGER THERE UNTIL WEDNESDAY AFTERNOON WHEN IT FINALLY SHIFTS EAST. IN THE MEANTIME...INSTABILITY INDUCED SHOWERS WILL REMAIN POSSIBLE ACROSS MAINLY THE SOUTHERN GREAT BASIN AND SIERRA BOTH TUESDAY AND WEDNESDAY. TEMPERATURES AREA WIDE WILL BE 10 TO 15 DEGREES BELOW NORMAL. .LONG TERM...THURSDAY THROUGH MONDAY. HIGH PRESSURE RIDGE WILL BEGIN TO BUILD INTO THE WESTERN STATES BY THURSDAY RESULTING IN IMPROVING WEATHER CONDITIONS AND A WARMING TREND. IN FACT...TEMPERATURES WILL CLIMB PRETTY RAPIDLY THROUGH THE WEEKEND...POSSIBLY REACHING THE MID 80S BY MONDAY FOR LAS VEGAS AND CLIMBING INTO THE 90S FOR DEATH VALLEY AND THE LOWER COLORADO RIVER. LONGER RANGE MODELS HINT AT THE POSSIBILITY OF ANOTHER STORM SYSTEM IMPACTING THE REGION BY THE MIDDLE OF NEXT WEEK. && .AVIATION...FOR MCCARRAN...AN AIRPORT WEATHER WARNING IS IN EFFECT FOR THE KLAS TERMINAL AREA FROM 1500 TO 1800 PDT THIS AFTERNOON FOR SOUTHWEST WINDS GUSTING UP TO 52 KTS. THIS IS DUE TO A VIGOROUS STORM MOVING INTO SOUTHERN NEVADA FROM CENTRAL CALIFORNIA. SOUTHWEST WINDS WILL DECREASE MODERATELY THIS EVENING AS THE SYSTEM MOVES OVERHEAD...BUT GUSTS OF 30-35 KTS WILL STILL BE POSSIBLE THROUGH MIDNIGHT PDT. SHOWERS WILL MOVE DOWN INTO THE NORTHWEST PART OF THE LAS VEGAS VALLEY LATE TONIGHT AND EARLY TUESDAY MORNING BUT CLOUD BASES SHOULD GENERALLY REMAIN ABOVE 8 KFT. WIND SPEEDS WILL BE SIGNIFICANTLY LIGHTER TUESDAY BUT SPEEDS SHOULD GENERALLY STAY ABOVE 10 KNOTS WITH A WEST TO NORTHWEST COMPONENT. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...WIDESPREAD SOUTHWEST WINDS GUSTING 40-55 KTS ACROSS THE MOJAVE DESERT REGION WILL DECREASE SLIGHTLY THIS EVENING BUT GUSTS OF 30-40KTS WILL BE COMMON THROUGH 12Z TUESDAY AS A VIGOROUS STORM MOVES FROM CALIFORNIA INTO NEVADA. SCATTERED TO NUMEROUS RAIN SHOWERS AND SNOW SHOWERS AND ISOLATED THUNDERSTORMS CAN BE EXPECTED OVER SOUTH CENTRAL NEVADA THROUGH TUESDAY. WINDS WILL GENERALLY BE FROM THE WEST TO NORTHWEST AT 10-20 KNOTS ACROSS THE ENTIRE REGION TUESDAY. && .SPOTTER INFORMATION STATEMENT...STRONG WINDS WILL CONTINUE TO IMPACT MUCH OF THE REGION THIS EVENING AND SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WINDS...REDUCTIONS IN VISIBILITY...OR DAMAGE ACCORDING TO STANDARD OPERATING PROCEDURES. && $$ SHORT/LONG TERM...OUTLER AVIATION...ADAIR FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
Area Forecast Discussion...UPDATED National Weather Service Reno NV 1115 AM PDT MON MAR 28 2016 .UPDATE... We have allowed the Winter Weather Advisory to expire at 11am. There are still a few locations with chain controls in western NV, although road conditions will continue to improve through the day as the road surfaces warm up and melt off the snow. Additional light accumulations of up to an inch or less are expected. Snow showers will continue to shift further south of Highway 50 during the afternoon and this evening. Hoon && .PREVIOUS DISCUSSION... /Issued 933 AM PDT MON MAR 28 2016/ UPDATE... Heavy snow amounts are being reported around the Reno- Sparks area this morning with many locations about 5 to 10 inches so far--a classic "slider" type system. HRRR model is showing additional snow around the I-80 corridor through about 11am this morning, then shifting south towards Highway 50 late morning and into the afternoon. Additional snowfall of up to a few inches will be possible over the next few hours, but snow will get lighter and have trouble sticking as we get into the afternoon hours. Also, road conditions should be improving as well as roads start to melt off. Unstable conditions will keep snow showers and clouds around through the afternoon as well, temperatures may struggle to reach 40 degrees in the valleys of western NV. Hoon AVIATION... Moderate to heavy snow at KRNO is causing IFR CIG/VIS. These conditions will likely continue through the morning at KRNO, with conditions beginning to improve this afternoon. Additional snowfall is expected, but with temperatures rising only an inch or two of slush will accumulate on the runways. Conditions have improved to VFR at KTVL, but as showers pick up this afternoon, we could have conditions lower back down to MVFR/IFR. Hoon PREVIOUS DISCUSSION... /Issued 619 AM PDT MON MAR 28 2016/ UPDATE... Band of moderate to occasionally heavy snow continues along and north of the I-80 corridor with the southern edge of the band sliding ever so slowly south toward Carson City-Dayton. Snow amounts have been in the 2 to 5 inch range thus far in the heavier snow bands with gusty north winds resulting in localized blowing and drifting snow. Latest finer scale HRRR model run indicates only a very slow drift south and east during the morning hours and then accelerating southward around 18-20z. There may be occasional letups at KTRK-KRNO-KLOL-KCXP, but given the stationary nature of this system, CIGS/VSBY will remain restricted with MVFR/periods of IFR continuing through 18z. PREVIOUS DISCUSSION... /Issued 337 AM PDT MON MAR 28 2016/ UPDATE... The band continues to develop near and north of I-80 at this hour. Latest models keep the band in this vicinity through 8 AM before it slowly shifts south. Updating to keep most snow accumulation near and north of I-80 and reducing accumulations near and south of Highway 50. Also canceling the advisory for southern Lyon County as the band will not make it there until late morning. By then, solar heating will be enough to preclude any road accumulation. Wallmann SYNOPSIS... A strong cold front will continue moving through the Sierra and Western Nevada this morning. Snow showers will occur behind the front today with the heaviest band expected along I-80 this morning. The upper low will continue to influence area weather into Wednesday as it slowly pulls east with scattered showers and cold temperatures. Mild and dry weather returns for late week. PREVIOUS DISCUSSION... /Issued 238 AM PDT MON MAR 28 2016/ SYNOPSIS... A strong cold front will continue moving through the Sierra and Western Nevada this morning. Snow showers will occur behind the front today with the heaviest band expected along I-80 this morning. The upper low will continue to influence area weather into Wednesday as it slowly pulls east with scattered showers and cold temperatures. Mild and dry weather returns for late week. SHORT TERM... The snow event is getting underway as I write this. The surface cold front is now along a line from Portola to Palomino Valley and then almost to Highway 50 in Churchill County. Showers have developed west of the crest and are moving east along the boundary. Currently, temps are mild from I-80 southward and around 40-45 degrees, but are in the 30s behind the front. With precip now moving in along I-80, areas below 5000 feet will start as rain, but expect it to change to snow north of Highway 50 by 6 AM. As for the band, the NAM/GFS/HRRR are hitting the I-80 corridor the hardest. The NAM actually shows close to 1" of water in the Reno/Sparks North Valleys. This is likely overdone, but 1/2" seems plausible. With the cold air coming in, this will mostly be snow and 3-6" of snow seems likely along the I-80 corridor above 4500 feet. Lighter amounts farther south away from this main band. Roads will be slick this morning near I-80 and also into eastern Plumas County due to the snow. Be prepared for a longer than normal commute and the advisories will continue as is. One thing to note is that the band doesn`t make it to southern Lyon County until late morning. If this occurs, any snow that falls will melt on impact, especially on the roads due to the higher late March sun angle. As we move into the afternoon, the cold pool moves overhead and expect snow showers to continue across the area, but little accumulation due to solar heating. Any lake effect for Pyramid Lake looks less likely today as models now show the winds being more Northeast, and also 30+ kts at 700 mb. This is in addition to the diurnal minimum in LES during the afternoon. Still, plenty of showers will be around in the instability. The upper low then only slowly pulls away into Wednesday. A northeast flow will continue on the backside Tuesday and Wednesday. Showers look more likely Tuesday as the cold pool remains close enough. Wednesday the instability is weaker and more south of I-80 so just have a slight chance of showers there. Temperatures will slowly moderate from today`s much below average readings, but remain below normal into Wednesday. Wallmann LONG TERM...Thursday through Sunday... Only minor changes were made as the previous forecast thinking is on track. Temperatures will begin to warm Thursday although northeast flow aloft will persist for one more day and keep the warmup slow initially. This will be the poorest day for mixing as surface warming will not keep up with warming temperatures aloft, resulting in moderate inversions. Friday, we expect temperatures to jump 7-10 degrees with a better mixing profile. For the weekend, instability and weak shortwave may be sufficient for isolated showers (probably not much more) across far northeast CA and northwest NV. Given the northern track of this shortwave, showers in the Sierra are unlikely and we have removed the mention there. Otherwise, it is going to be an unseasonably mild weekend with highs in the upper 50s to around 60 Sierra valleys and mid 60s to low 70s western NV valleys. AVIATION... A cold front moving southward into western NV early this morning will continue to drop south and allow colder air to settle into the I-80/Hwy 50 corridors. Meanwhile, instability continues to increase as upper low drops into the region with band of rain and snow intensifying near and north of I-80. Some models are indicating some impressive bands of precipitation developing through 15z and right now, it appears that zone will be very close to where it is setting up currently which would have bigger impacts for KTRK-KRNO-KLOL. Temps and dewpoints are currently too warm for much accumulation below 5000 feet and this will likely remain the case outside of heavier bands of precipitation even though we do anticipate a changeover to all snow during the morning hours. So the key to getting accumulation on area runways will be location of most intense snow bands prior to 16z. Light accumulations are already occurring at KTRK and we will just have to monitor radar trends for KRNO-KLOL. The band is forecast to slide south into Mono-Mineral County this afternoon and evening with some light accumulations possible at KMMH near or after sundown. Right now, due to the timing of the band (later in the morning) at KTVL-KCXP-KNFL, accumulations look minimal. There could still be some brief slushy accumulations if snow showers become sufficiently heavy. But any accumulation will melt quickly once the snow showers pass. Otherwise, expect periods of IFR/MVFR CIGS/VSBY during snow showers with terrain obscurement, especially close to the Sierra. Hohmann && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$ For more information from the National Weather Service visit... http://weather.gov/reno
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1000 AM PDT MON MAR 28 2016 .SYNOPSIS...WIDESPREAD STRONG WINDS ARE EXPECTED ACROSS THE MOJAVE DESERT AND SOUTHERN GREAT BASIN TODAY AS A LOW PRESSURE SYSTEM PUSHES INTO THE AREA. THIS WILL ALSO BRING CHANCES FOR SHOWERS TO AREAS FROM LAS VEGAS NORTHWARD TODAY AND TUESDAY. THE SYSTEM WILL THEN SLOWLY PULL AWAY FOLLOWED BY A WARMING TREND THE SECOND HALF OF THE WEEK. && .UPDATE...STILL ANTICIPATING A SIGNIFICANT WIND EVENT PEAKING THIS AFTERNOON WITH WIDESPREAD GUSTS OVER 50 MPH LIKELY...WITH LOCALIZED GUSTS EXCEEDING 65 MPH. BLOWING DUST ALREADY PROBLEMATIC THIS MORNING WITH HENDERSON AIRPORT REPORTING 1 MILE VISIBILITY AT THIS HOUR. NO UPDATE PLANNED THIS MORNING AS THE FORECAST IS IN GOOD SHAPE. -OUTLER- && .AVIATION...FOR MCCARRAN...A SIGNIFICANT WIND EVENT IS ON TAP THIS AFTERNOON AND EVENING. AN AIRPORT WEATHER WARNING HAS BEEN ISSUED FOR THE TERMINAL AREA FROM 1500 TO 1800 PDT THIS AFTERNOON FOR SOUTHWEST WINDS GUSTING UP TO 52 KTS. THE LATEST COMPUTER MODEL WIND FORECASTS AND THE GENERAL TRACK OF THE APPROACHING LOW PRESSURE SYSTEM DIVING FROM CENTRAL CALIFORNIA INTO SOUTHERN NEVADA THIS AFTERNOON HAVE BOOSTED CONFIDENCE THAT GUSTS OF 48-52 KTS ARE LIKELY DURING THIS PERIOD. SOUTHWEST WINDS WERE ALREADY GUSTING 30-35 KTS THIS MORNING AND WINDS WILL CONTINUE TO INCREASE AND PEAK IN INTENSITY BETWEEN 22Z-01Z. POCKETS OF SEVERE TURBULENCE CAN BE EXPECTED ALONG WITH AREAS OF BLOWING DUST. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...A MAJOR WIND EVENT WILL STRIKE THE REGION TODAY RESULTING IN POCKETS OF SEVERE TURBULENCE AND BLOWING DUST AND SAND. STRONGEST WINDS WILL BE ALONG A BELT FROM RIDGECREST TO ELY AND POINTS EAST. WIND GUSTS MAY EXCEED 50KTS AT TIMES. && .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT. A LARGE...COLD UPPER LEVEL LOW WILL PUSH INTO THE AREA TODAY. NOT MUCH CHANCE TO THE GOING FORECAST THIS MORNING...WITH WIDESPREAD STRONG WINDS EXPECTED ACROSS MOST OF THE REGION. THE MAIN NOTABLE CHANGE THIS MORNING WAS UPGRADING THE WIND ADVISORY TO A HIGH WIND WARNING FOR DEATH VALLEY NATIONAL PARK. THE LATEST HIGH-RES GUIDANCE HAS SHIFTED THE CORE OF THE STRONGEST WINDS A HAIR NORTH WITH THE LATEST RUNS...AND IS NOW EXPECTED TO IMPACT AT LEAST THE SOUTHERN PORTIONS OF THE PARK. WIDESPREAD AREAS OF BLOWING DUST IS ALSO LIKELY TODAY...AND REMAINS NOTED IN THE FORECAST. THE PRECIPITATION FORECAST REMAINS FAIRLY CONSISTENT...WITH SHOWERS EXPECTED TO BREAK OUT ACROSS AREAS MAINLY NORTH OF LAS VEGAS THIS AFTERNOON AND EVENING. THERE IS SOME WEAK INSTABILITY NOTED ACROSS THE SOUTHERN GREAT BASIN...AND A MENTION OF THUNDER WAS ADDED TO PORTIONS OF LINCOLN...NYE AND ESMERALDA COUNTIES. WINDS WILL DECREASE BEHIND A COLD FRONT THAT WILL SWEEP ACROSS THE REGION TONIGHT...HOWEVER NORTHERLY BREEZES CAN BE EXPECTED THROUGH TUESDAY. THERE IS SOME CONCERN THAT ADVISORY LEVEL WINDS COULD CONTINUE ACROSS THE NORTHWEST PART OF THE FORECAST AREA INTO TUESDAY...BUT RIGHT NOW IT APPEARS MAINLY CONFINED TO THE RIDGES.TEMPERAURES WILL PLUNGE BEHIND THE COLD FRONT TONIGHT...CAUSING SNOW LEVELS TO LOWER TO 4-5K FEET ACROSS THE NORTHERN ZONES AS PRECIPITATION BECOMES SOMEWHAT MORE SHOWERY. THIS COULD LEAD TO SOME LIGHT SNOW ACCUMULATIONS DOWN TO THE VALLEY FLOORS ACROSS ESMERALDA...CENTRAL NYE...AND NORTHERN LINCOLN COUNTIES. HOWEVER...WITH THE WARM SURFACE TEMPERATURES OF LATE AND SHOWERY NATURE I DO NOT EXPECT SIGNIFICANT IMPACTFUL ACCUMULATION...MAINLY A TRACE TO 1-2 INCHES. CONDITIONS WILL CONTINUE TO IMPROVE WEDNESDAY WITH TEMPERATURES STARTING A SLOW CLIMB AND WINDS MAINLY LIGHT AND VARIABLE IN NATURE. .LONG TERM...THURSDAY THROUGH MONDAY. THE LONG TERM PERIOD BEGINS IN A SPLIT FLOW REGIME ACROSS THE REGION...AS THE MAIN UPPER LOW RESPONSIBLE FOR THE UNSETTLED EARLY WEEK WEATHER WILL HAVE DEPARTED THE REGION AND A SECONDARY TROUGH WILL BE IN THE PROCESS OF DIGGING SOUTHWARD ACROSS WESTERN PORTIONS OF THE DESERT SOUTHWEST AND NORTHERN MEXICO. OPERATIONAL MODEL GUIDANCE REMAINS CONSISTENT IN INDICATING ONLY MEAGER MOISTURE PROFILES AT BEST WITH THIS SYSTEM...WITH THE BEST AREAS OF MOISTURE GENERALLY SOUTH OF THE CWA BY THURSDAY MORNING. THEREFORE...VARIABLE CLOUD COVER AND BREEZY NORTHERLY WINDS LOOK TO BE THE MOST LIKELY WEATHER CONDITIONS WITH THIS SYSTEM THROUGH FRIDAY MORNING. AS THE SECONDARY TROUGH EXITS THE REGION TO THE SOUTHEAST FRIDAY ...SHORTWAVE RIDGING WILL BUILD INTO THE AREA RESULTING IN THE CONTINUED RAPID INCREASE IN TEMPERATURE EACH DAY THROUGH THE END OF THE WEEKEND. TO GIVE SOME PERSPECTIVE ON HOW QUICK WE WILL WARM UP...FORECAST HIGHS BY THE WEEKEND ARE GENERALLY 15-20 DEGREES WARMER ACROSS THE REGION COMPARED TO FORECAST HIGHS FOR WEDNESDAY. OPERATIONAL MODEL SOLUTIONS GENERALLY DIVERGE ON THE EVOLUTION OF OUR OVERALL PATTERN AND RESULTANT WEATHER AT THE END OF THE FORECAST PERIOD. && .SPOTTER INFORMATION STATEMENT...STRONG WINDS WILL IMPACT MUCH OF THE REGION TODAY AND SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WINDS...REDUCTIONS IN VISIBILITY...OR DAMAGE ACCORDING TO STANDARD OPERATING PROCEDURES. && $$ SHORT TERM...WOLCOTT LONG TERM....PULLIN AVIATION.....ADAIR FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
Area Forecast Discussion...UPDATED National Weather Service Reno NV 933 AM PDT MON MAR 28 2016 .UPDATE... Heavy snow amounts are being reported around the Reno- Sparks area this morning with many locations about 5 to 10 inches so far--a classic "slider" type system. HRRR model is showing additional snow around the I-80 corridor through about 11am this morning, then shifting south towards Highway 50 late morning and into the afternoon. Additional snowfall of up to a few inches will be possible over the next few hours, but snow will get lighter and have trouble sticking as we get into the afternoon hours. Also, road conditions should be improving as well as roads start to melt off. Unstable conditions will keep snow showers and clouds around through the afternoon as well, temperatures may struggle to reach 40 degrees in the valleys of western NV. Hoon && .AVIATION... Moderate to heavy snow at KRNO is causing IFR CIG/VIS. These conditions will likely continue through the morning at KRNO, with conditions beginning to improve this afternoon. Additional snowfall is expected, but with temperatures rising only an inch or two of slush will accumulate on the runways. Conditions have improved to VFR at KTVL, but as showers pick up this afternoon, we could have conditions lower back down to MVFR/IFR. Hoon && .PREVIOUS DISCUSSION... /Issued 619 AM PDT MON MAR 28 2016/ UPDATE... Band of moderate to occasionally heavy snow continues along and north of the I-80 corridor with the southern edge of the band sliding ever so slowly south toward Carson City-Dayton. Snow amounts have been in the 2 to 5 inch range thus far in the heavier snow bands with gusty north winds resulting in localized blowing and drifting snow. Latest finer scale HRRR model run indicates only a very slow drift south and east during the morning hours and then accelerating southward around 18-20z. There may be occasional letups at KTRK-KRNO-KLOL-KCXP, but given the stationary nature of this system, CIGS/VSBY will remain restricted with MVFR/periods of IFR continuing through 18z. PREVIOUS DISCUSSION... /Issued 337 AM PDT MON MAR 28 2016/ UPDATE... The band continues to develop near and north of I-80 at this hour. Latest models keep the band in this vicinity through 8 AM before it slowly shifts south. Updating to keep most snow accumulation near and north of I-80 and reducing accumulations near and south of Highway 50. Also canceling the advisory for southern Lyon County as the band will not make it there until late morning. By then, solar heating will be enough to preclude any road accumulation. Wallmann SYNOPSIS... A strong cold front will continue moving through the Sierra and Western Nevada this morning. Snow showers will occur behind the front today with the heaviest band expected along I-80 this morning. The upper low will continue to influence area weather into Wednesday as it slowly pulls east with scattered showers and cold temperatures. Mild and dry weather returns for late week. PREVIOUS DISCUSSION... /Issued 238 AM PDT MON MAR 28 2016/ SYNOPSIS... A strong cold front will continue moving through the Sierra and Western Nevada this morning. Snow showers will occur behind the front today with the heaviest band expected along I-80 this morning. The upper low will continue to influence area weather into Wednesday as it slowly pulls east with scattered showers and cold temperatures. Mild and dry weather returns for late week. SHORT TERM... The snow event is getting underway as I write this. The surface cold front is now along a line from Portola to Palomino Valley and then almost to Highway 50 in Churchill County. Showers have developed west of the crest and are moving east along the boundary. Currently, temps are mild from I-80 southward and around 40-45 degrees, but are in the 30s behind the front. With precip now moving in along I-80, areas below 5000 feet will start as rain, but expect it to change to snow north of Highway 50 by 6 AM. As for the band, the NAM/GFS/HRRR are hitting the I-80 corridor the hardest. The NAM actually shows close to 1" of water in the Reno/Sparks North Valleys. This is likely overdone, but 1/2" seems plausible. With the cold air coming in, this will mostly be snow and 3-6" of snow seems likely along the I-80 corridor above 4500 feet. Lighter amounts farther south away from this main band. Roads will be slick this morning near I-80 and also into eastern Plumas County due to the snow. Be prepared for a longer than normal commute and the advisories will continue as is. One thing to note is that the band doesn`t make it to southern Lyon County until late morning. If this occurs, any snow that falls will melt on impact, especially on the roads due to the higher late March sun angle. As we move into the afternoon, the cold pool moves overhead and expect snow showers to continue across the area, but little accumulation due to solar heating. Any lake effect for Pyramid Lake looks less likely today as models now show the winds being more Northeast, and also 30+ kts at 700 mb. This is in addition to the diurnal minimum in LES during the afternoon. Still, plenty of showers will be around in the instability. The upper low then only slowly pulls away into Wednesday. A northeast flow will continue on the backside Tuesday and Wednesday. Showers look more likely Tuesday as the cold pool remains close enough. Wednesday the instability is weaker and more south of I-80 so just have a slight chance of showers there. Temperatures will slowly moderate from today`s much below average readings, but remain below normal into Wednesday. Wallmann LONG TERM...Thursday through Sunday... Only minor changes were made as the previous forecast thinking is on track. Temperatures will begin to warm Thursday although northeast flow aloft will persist for one more day and keep the warmup slow initially. This will be the poorest day for mixing as surface warming will not keep up with warming temperatures aloft, resulting in moderate inversions. Friday, we expect temperatures to jump 7-10 degrees with a better mixing profile. For the weekend, instability and weak shortwave may be sufficient for isolated showers (probably not much more) across far northeast CA and northwest NV. Given the northern track of this shortwave, showers in the Sierra are unlikely and we have removed the mention there. Otherwise, it is going to be an unseasonably mild weekend with highs in the upper 50s to around 60 Sierra valleys and mid 60s to low 70s western NV valleys. AVIATION... A cold front moving southward into western NV early this morning will continue to drop south and allow colder air to settle into the I-80/Hwy 50 corridors. Meanwhile, instability continues to increase as upper low drops into the region with band of rain and snow intensifying near and north of I-80. Some models are indicating some impressive bands of precipitation developing through 15z and right now, it appears that zone will be very close to where it is setting up currently which would have bigger impacts for KTRK-KRNO-KLOL. Temps and dewpoints are currently too warm for much accumulation below 5000 feet and this will likely remain the case outside of heavier bands of precipitation even though we do anticipate a changeover to all snow during the morning hours. So the key to getting accumulation on area runways will be location of most intense snow bands prior to 16z. Light accumulations are already occurring at KTRK and we will just have to monitor radar trends for KRNO-KLOL. The band is forecast to slide south into Mono-Mineral County this afternoon and evening with some light accumulations possible at KMMH near or after sundown. Right now, due to the timing of the band (later in the morning) at KTVL-KCXP-KNFL, accumulations look minimal. There could still be some brief slushy accumulations if snow showers become sufficiently heavy. But any accumulation will melt quickly once the snow showers pass. Otherwise, expect periods of IFR/MVFR CIGS/VSBY during snow showers with terrain obscurement, especially close to the Sierra. Hohmann && .REV Watches/Warnings/Advisories... NV...Winter Weather Advisory until 11 AM PDT this morning NVZ003-004. CA...None. && $$ For more information from the National Weather Service visit... http://weather.gov/reno
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
830 AM PDT MON MAR 28 2016 .SYNOPSIS...WIDESPREAD STRONG WINDS ARE EXPECTED ACROSS THE MOJAVE DESERT AND SOUTHERN GREAT BASIN TODAY AS A LOW PRESSURE SYSTEM PUSHES INTO THE AREA. THIS WILL ALSO BRING CHANCES FOR SHOWERS TO AREAS FROM LAS VEGAS NORTHWARD TODAY AND TUESDAY. THE SYSTEM WILL THEN SLOWLY PULL AWAY FOLLOWED BY A WARMING TREND THE SECOND HALF OF THE WEEK. && .UPDATE...STILL ANTICIPATING A SIGNIFICANT WIND EVENT PEAKING THIS AFTERNOON WITH WIDESPREAD GUSTS OVER 50 MPH LIKELY...WITH LOCALIZED GUSTS EXCEEDING 65 MPH. BLOWING DUST ALREADY PROBLEMATIC THIS MORNING WITH HENDERSON AIRPORT REPORTING 1 MILE VISIBILITY AT THIS HOUR. NO UPDATE PLANNED THIS MORNING AS THE FORECAST IS IN GOOD SHAPE. -OUTLER- && .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT. A LARGE...COLD UPPER LEVEL LOW WILL PUSH INTO THE AREA TODAY. NOT MUCH CHANCE TO THE GOING FORECAST THIS MORNING...WITH WIDESPREAD STRONG WINDS EXPECTED ACROSS MOST OF THE REGION. THE MAIN NOTABLE CHANGE THIS MORNING WAS UPGRADING THE WIND ADVISORY TO A HIGH WIND WARNING FOR DEATH VALLEY NATIONAL PARK. THE LATEST HIGH-RES GUIDANCE HAS SHIFTED THE CORE OF THE STRONGEST WINDS A HAIR NORTH WITH THE LATEST RUNS...AND IS NOW EXPECTED TO IMPACT AT LEAST THE SOUTHERN PORTIONS OF THE PARK. WIDESPREAD AREAS OF BLOWING DUST IS ALSO LIKELY TODAY...AND REMAINS NOTED IN THE FORECAST. THE PRECIPITATION FORECAST REMAINS FAIRLY CONSISTENT...WITH SHOWERS EXPECTED TO BREAK OUT ACROSS AREAS MAINLY NORTH OF LAS VEGAS THIS AFTERNOON AND EVENING. THERE IS SOME WEAK INSTABILITY NOTED ACROSS THE SOUTHERN GREAT BASIN...AND A MENTION OF THUNDER WAS ADDED TO PORTIONS OF LINCOLN...NYE AND ESMERALDA COUNTIES. WINDS WILL DECREASE BEHIND A COLD FRONT THAT WILL SWEEP ACROSS THE REGION TONIGHT...HOWEVER NORTHERLY BREEZES CAN BE EXPECTED THROUGH TUESDAY. THERE IS SOME CONCERN THAT ADVISORY LEVEL WINDS COULD CONTINUE ACROSS THE NORTHWEST PART OF THE FORECAST AREA INTO TUESDAY...BUT RIGHT NOW IT APPEARS MAINLY CONFINED TO THE RIDGES.TEMPERAURES WILL PLUNGE BEHIND THE COLD FRONT TONIGHT...CAUSING SNOW LEVELS TO LOWER TO 4-5K FEET ACROSS THE NORTHERN ZONES AS PRECIPITATION BECOMES SOMEWHAT MORE SHOWERY. THIS COULD LEAD TO SOME LIGHT SNOW ACCUMULATIONS DOWN TO THE VALLEY FLOORS ACROSS ESMERALDA...CENTRAL NYE...AND NORTHERN LINCOLN COUNTIES. HOWEVER...WITH THE WARM SURFACE TEMPERATURES OF LATE AND SHOWERY NATURE I DO NOT EXPECT SIGNIFICANT IMPACTFUL ACCUMULATION...MAINLY A TRACE TO 1-2 INCHES. CONDITIONS WILL CONTINUE TO IMPROVE WEDNESDAY WITH TEMPERATURES STARTING A SLOW CLIMB AND WINDS MAINLY LIGHT AND VARIABLE IN NATURE. .LONG TERM...THURSDAY THROUGH MONDAY. THE LONG TERM PERIOD BEGINS IN A SPLIT FLOW REGIME ACROSS THE REGION...AS THE MAIN UPPER LOW RESPONSIBLE FOR THE UNSETTLED EARLY WEEK WEATHER WILL HAVE DEPARTED THE REGION AND A SECONDARY TROUGH WILL BE IN THE PROCESS OF DIGGING SOUTHWARD ACROSS WESTERN PORTIONS OF THE DESERT SOUTHWEST AND NORTHERN MEXICO. OPERATIONAL MODEL GUIDANCE REMAINS CONSISTENT IN INDICATING ONLY MEAGER MOISTURE PROFILES AT BEST WITH THIS SYSTEM...WITH THE BEST AREAS OF MOISTURE GENERALLY SOUTH OF THE CWA BY THURSDAY MORNING. THEREFORE...VARIABLE CLOUD COVER AND BREEZY NORTHERLY WINDS LOOK TO BE THE MOST LIKELY WEATHER CONDITIONS WITH THIS SYSTEM THROUGH FRIDAY MORNING. AS THE SECONDARY TROUGH EXITS THE REGION TO THE SOUTHEAST FRIDAY ...SHORTWAVE RIDGING WILL BUILD INTO THE AREA RESULTING IN THE CONTINUED RAPID INCREASE IN TEMPERATURE EACH DAY THROUGH THE END OF THE WEEKEND. TO GIVE SOME PERSPECTIVE ON HOW QUICK WE WILL WARM UP...FORECAST HIGHS BY THE WEEKEND ARE GENERALLY 15-20 DEGREES WARMER ACROSS THE REGION COMPARED TO FORECAST HIGHS FOR WEDNESDAY. OPERATIONAL MODEL SOLUTIONS GENERALLY DIVERGE ON THE EVOLUTION OF OUR OVERALL PATTERN AND RESULTANT WEATHER AT THE END OF THE FORECAST PERIOD. && .AVIATION...FOR MCCARRAN...SIGNIFICANT WIND EVENT ON TAP THIS AFTERNOON AND EVENING. CONFIDENCE NOT HIGH ENOUGH TO ISSUE AN AIRPORT WEATHER WARNING AS MAJORITY OF SUSTAINED WIND SPEEDS AND WIND GUSTS SHOULD REMAIN BELOW CRITICAL THRESHOLDS. SOUTHWEST BREEZES IN THE 10-20 KT RANGE WITH GUSTS TO 30 KTS THROUGH THE MORNING HOURS, WINDS PEAK IN INTENSITY BETWEEN 21Z-04Z. POCKETS OF SEVERE TURBULENCE CAN BE EXPECTED ALONG WITH AREAS OF BLOWING DUST. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...A MAJOR WIND EVENT WILL STRIKE THE REGION TODAY RESULTING IN POCKETS OF SEVERE TURBULENCE AND BLOWING DUST AND SAND. STRONGEST WINDS WILL BE ALONG A BELT FROM RIDGECREST TO ELY AND POINTS EAST. WIND GUSTS MAY EXCEED 50KTS AT TIMES. && .SPOTTER INFORMATION STATEMENT...STRONG WINDS WILL IMPACT MUCH OF THE REGION TODAY AND SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WINDS...REDUCTIONS IN VISIBILITY...OR DAMAGE ACCORDING TO STANDARD OPERATING PROCEDURES. && $$ SHORT TERM...WOLCOTT LONG TERM....PULLIN AVIATION.....PIERCE FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
Area Forecast Discussion...UPDATED National Weather Service Reno NV 619 AM PDT MON MAR 28 2016 .UPDATE... Band of moderate to occasionally heavy snow continues along and north of the I-80 corridor with the southern edge of the band sliding ever so slowly south toward Carson City-Dayton. Snow amounts have been in the 2 to 5 inch range thus far in the heavier snow bands with gusty north winds resulting in localized blowing and drifting snow. Latest finer scale HRRR model run indicates only a very slow drift south and east during the morning hours and then accelerating southward around 18-20z. There may be occasionalletups at KTRK-KRNO-KLOL-KCXP, but given the stationary nature of this system, CIGS/VSBY will remain restricted with MVFR/periods of IFR continuing through 18z. && .PREVIOUS DISCUSSION... /Issued 337 AM PDT MON MAR 28 2016/ UPDATE... The band continues to develop near and north of I-80 at this hour. Latest models keep the band in this vicinity through 8 AM before it slowly shifts south. Updating to keep most snow accumulation near and north of I-80 and reducing accumulations near and south of Highway 50. Also cancelling the advisory for southern Lyon County as the band will not make it there until late morning. By then, solar heating will be enough to preclude any road accumulation. Wallmann SYNOPSIS... A strong cold front will continue moving through the Sierra and Western Nevada this morning. Snow showers will occur behind the front today with the heaviest band expected along I-80 this morning. The upper low will continue to influence area weather into Wednesday as it slowly pulls east with scattered showers and cold temperatures. Mild and dry weather returns for late week. PREVIOUS DISCUSSION... /Issued 238 AM PDT MON MAR 28 2016/ SYNOPSIS... A strong cold front will continue moving through the Sierra and Western Nevada this morning. Snow showers will occur behind the front today with the heaviest band expected along I-80 this morning. The upper low will continue to influence area weather into Wednesday as it slowly pulls east with scattered showers and cold temperatures. Mild and dry weather returns for late week. SHORT TERM... The snow event is getting underway as I write this. The surface cold front is now along a line from Portola to Palomino Valley and then almost to Highway 50 in Churchill County. Showers have developed west of the crest and are moving east along the boundary. Currently, temps are mild from I-80 southward and around 40-45 degrees, but are in the 30s behind the front. With precip now moving in along I-80, areas below 5000 feet will start as rain, but expect it to change to snow north of Highway 50 by 6 AM. As for the band, the NAM/GFS/HRRR are hitting the I-80 corridor the hardest. The NAM actually shows close to 1" of water in the Reno/Sparks North Valleys. This is likely overdone, but 1/2" seems plausible. With the cold air coming in, this will mostly be snow and 3-6" of snow seems likely along the I-80 corridor above 4500 feet. Lighter amounts farther south away from this main band. Roads will be slick this morning near I-80 and also into eastern Plumas County due to the snow. Be prepared for a longer than normal commute and the advisories will continue as is. One thing to note is that the band doesn`t make it to southern Lyon County until late morning. If this occurs, any snow that falls will melt on impact, especially on the roads due to the higher late March sun angle. As we move into the afternoon, the cold pool moves overhead and expect snow showers to continue across the area, but little accumulation due to solar heating. Any lake effect for Pyramid Lake looks less likely today as models now show the winds being more Northeast, and also 30+ kts at 700 mb. This is in addition to the diurnal minimum in LES during the afternoon. Still, plenty of showers will be around in the instability. The upper low then only slowly pulls away into Wednesday. A northeast flow will continue on the backside Tuesday and Wednesday. Showers look more likely Tuesday as the cold pool remains close enough. Wednesday the instability is weaker and more south of I-80 so just have a slight chance of showers there. Temperatures will slowly moderate from today`s much below average readings, but remain below normal into Wednesday. Wallmann LONG TERM...Thursday through Sunday... Only minor changes were made as the previous forecast thinking is on track. Temperatures will begin to warm Thursday although northeast flow aloft will persist for one more day and keep the warmup slow initially. This will be the poorest day for mixing as surface warming will not keep up with warming temperatures aloft, resulting in moderate inversions. Friday, we expect temperatures to jump 7-10 degrees with a better mixing profile. For the weekend, instability and weak shortwave may be sufficient for isolated showers (probably not much more) across far northeast CA and northwest NV. Given the northern track of this shortwave, showers in the Sierra are unlikely and we have removed the mention there. Otherwise, it is going to be an unseasonably mild weekend with highs in the upper 50s to around 60 Sierra valleys and mid 60s to low 70s western NV valleys. AVIATION... A cold front moving southward into western NV early this morning will continue to drop south and allow colder air to settle into the I-80/Hwy 50 corridors. Meanwhile, instability continues to increase as upper low drops into the region with band of rain and snow intensifying near and north of I-80. Some models are indicating some impressive bands of precipitation developing through 15z and right now, it appears that zone will be very close to where it is setting up currently which would have bigger impacts for KTRK-KRNO-KLOL. Temps and dewpoints are currently too warm for much accumulation below 5000 feet and this will likely remain the case outside of heavier bands of precipitation even though we do anticipate a changeover to all snow during the morning hours. So the key to getting accumulation on area runways will be location of most intense snow bands prior to 16z. Light accumulations are already occurring at KTRK and we will just have to monitor radar trends for KRNO-KLOL. The band is forecast to slide south into Mono-Mineral County this afternoon and evening with some light accumulations possible at KMMH near or after sundown. Right now, due to the timing of the band (later in the morning) at KTVL-KCXP-KNFL, accumulations look minimal. There could still be some brief slushy accumulations if snow showers become sufficiently heavy. But any accumulation will melt quickly once the snow showers pass. Otherwise, expect periods of IFR/MVFR CIGS/VSBY during snow showers with terrain obscurement, especially close to the Sierra. Hohmann && .REV Watches/Warnings/Advisories... NV...Winter Weather Advisory until 11 AM PDT this morning NVZ003-004. CA...None. && $$ For more information from the National Weather Service visit... http://weather.gov/reno
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
618 AM EDT MON MAR 28 2016 .SYNOPSIS... A DRYING TREND BEGINS TODAY AND CONTINUES THROUGH WEDNESDAY. WET CONDITIONS WILL RETURN LATE THURSDAY AND LINGER INTO THE WEEKEND AS ANOTHER COLD FRONT MOVES INTO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 615 AM MONDAY...A FEW REMAINING PATCHES OF LIGHT RAIN OR DRIZZLE ARE MOVING EAST ACROSS THE FORECAST AREA EARLY THIS MORNING. HAVE UPDATED THE FORECAST TO MOVE UP TIMING THAT PRECIP WILL EXIT THE AREA AND EXPECT DRY CONDITIONS NOT LONG AFTER SUNRISE. PREVIOUS DISCUSSION FOLLOWS: PATCHY LIGHT RAIN AND DRIZZLE ARE MOVING EAST TO WEST ACROSS THE FORECAST AREA THIS MORNING. RADAR LOOPS AND PROJECTIONS SHOW COVERAGE WILL INCREASE A BIT OVER THE NEXT FEW HOURS BEFORE FADING BY AROUND SUNRISE. AT THE SURFACE WE HAVE A LOW CENTER AND ASSOCIATED FRONTAL SYSTEM MOVING EAST UP THE COAST JUST OFFSHORE WHILE A COLD FRONT DESCENDS FROM THE NW. THIS COLD FRONT WILL MOVE OFFSHORE LATE THIS AFTERNOON OR EARLY EVENING AS THE OFFSHORE SYSTEM MOVES VERY QUICKLY NE TOWARDS NEW ENGLAND. ISENTROPIC LIFT ASSOCIATED WITH THE OFFSHORE SYSTEM BRINGING PRESENT ROUND OF MAINLY STRATIFORM PRECIPITATION...WHICH WILL END THIS MORNING AS THE SYSTEM EXITS TO THE NE. THE EXITING SYSTEM WILL PULL MUCH OF THE DEEP MOISTURE AWAY WITH IT...LEAVING LITTLE FOR THE COLD FRONT TO WORK WITH LATER ON TODAY. SKIES WILL GRADUALLY SCATTER OUT AS THE DAY WEARS ON. COOL AND DRY HIGH PRESSURE WILL FOLLOW FOR TONIGHT...NOSING IN FROM THE NW. TEMPERATURES WILL RETURN TO MORE SEASONAL LEVELS OVERNIGHT...WITH LOWS IN THE MID TO UPPER 40S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...VERY PROGRESSIVE PATTERN CONTINUES AS COOL AND DRY HIGH PRESSURE DROPS SOUTHEAST OVER THE FORECAST AREA TUESDAY AND WEDNESDAY...MOVING OFFSHORE WEDNESDAY NIGHT. ALTHOUGH WE WILL SEE A BIT OF A WARMING TREND....TEMPERATURES ON TUESDAY AND WEDNESDAY WILL BE WITHIN A FEW DEGREES OF CLIMO. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 300 AM MONDAY...A PATTERN CHANGE IS IN THE OFFING FOR THE EASTERN CAROLINAS DURING THE EXTENDED PERIOD. A DEEP MID LEVEL TROUGH OUT WEST WILL LINK UP WITH A DEVELOPING DEEP TROUGH FROM CANADA AND MOVE SLOWLY EASTWARD THROUGH THE PERIOD. A MOIST SOUTHWEST FLOW DEVELOPS THURSDAY THROUGH EARLY SATURDAY WITH THIS PATTERN. GUIDANCE CONTINUES TO ADVERTISE TWO PERIODS OF STRONGLY FORCED SHOWERS AND POSSIBLY EVEN THUNDER. THE FIRST ARRIVES LATE THURSDAY INTO EARLY FRIDAY WITH ANOTHER ROUND FRIDAY AFTERNOON INTO THE EVENING. WE CONTINUE TO ADVERTISE LIKELY POPS THROUGH THIS TIME FRAME WITH ACTIVITY COMING TO AN END EARLY SATURDAY. CLEARING AND COOLER LATE SATURDAY AND SUNDAY AS THE DEEP MID LEVEL TROUGH BRINGS ALONG WITH IT 850MB TEMPERATURES BRIEFLY JUST ABOVE FREEZING. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... AS OF 06Z... WHILE THERE ARE POCKETS OF CONVECTION ON RADAR PREDOMINATELY IT IS STRATIFORM RAIN AND WILL REMAIN SO FOR MOST OF THE OVERNIGHT HOURS. AS THE LOW APPROACHES HOWEVER...THERE MAY BE OCCASIONAL THUNDER...PARTICULARLY ALONG THE COAST OR OFFSHORE NEAR THE LOW`S TRACK. HAVE SLOWED THINGS DOWN AN HOUR OR TWO...BASED MAINLY ON THE HRRR MODEL. CEILINGS AND VISIBILITIES WILL BOUNCE AROUND A BIT...BUT WILL BE PREDOMINATELY IFR/LIFR. NOT VERY CONFIDENT ON ANY DENSE FOG...MAINLY BECAUSE THE WINDS WILL STAY AROUND 5 KTS OR BETTER. THE GFS SHUTS OFF THE MOISTURE BY 07Z...BUT THINK THIS IS A BIT FAST. LOOK FOR IMPROVING CONDITIONS AROUND DAYBREAK WITH VFR CONDITIONS SHORTLY AFTER WITH A WEST WIND. EXTENDED OUTLOOK...VFR THROUGH WEDNESDAY. MVFR SHOWERS AND CEILINGS POSSIBLE THURSDAY AND FRIDAY. FRIDAY MAY INCLUDE THUNDERSTORMS AS WELL. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 615 AM MONDAY...NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: HAVE DROPPED SCEC HEADLINES WITH THE LATEST ISSUANCE AS OFFSHORE LOW IS MOVING NE ALMOST DIRECTLY OVER THE WATERS...KEEPING GRADIENT SLACKER THAN EXPECTED. THIS SYSTEM WILL MOVE RAPIDLY NE AS A COLD FRONT DESCENDS FROM THE NW. THE COLD FRONT WILL MOVE OFFSHORE LATE THIS AFTERNOON OR EARLY EVENING...FOLLOWED BY HIGH PRESSURE NOSING IN FROM THE NW OVERNIGHT. DO NOT EXPECT ANY FLAGS FOR THE NEAR TERM...BUT IT IS POSSIBLE WE COULD SEE GUSTY WINDS IN THE 20 TO 25 KT RANGE THIS AFTERNOON. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...MONDAY...HIGH PRESSURE WILL DOMINATE THE SHORT TERM AS IT MOVES OVERHEAD TUESDAY AND WEDNESDAY AND THEN EAST OF THE WATERS WEDNESDAY NIGHT. DO NOT EXPECT ANY HEADLINES FOR THIS PERIOD...ALTHOUGH SEAS MAY REMAIN ELEVATED AT 3 TO 5 FT EARLY IN THE PERIOD. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 300 AM MONDAY...EXTENDED MARINE FORECAST BRINGS RUGGED CONDITIONS TO ALL WATERS. A STRONG COLD FRONT WILL BRING SOUTH TO SOUTHWEST WINDS OF 20-25 KNOTS THURSDAY WELL INTO THE DAY FRIDAY. THE SPEEDS DO BACK OFF A LITTLE FRIDAY. LATE IN THE PERIOD THE FLOW WEAKENS FURTHER AS WINDS SHIFT TO THE WEST. SMALL CRAFT SEAS AND THEN SOME FOR MOST OF THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK NEAR TERM...REK SHORT TERM...REK LONG TERM...SHK AVIATION...DL MARINE...REK/SHK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
300 AM EDT MON MAR 28 2016 .SYNOPSIS... A COOLING AND DRYING TREND BEGINS TODAY AND CONTINUES THROUGH WEDNESDAY. WET CONDITIONS WILL RETURN LATE THURSDAY AND LINGER INTO THE WEEKEND AS ANOTHER COLD FRONT MOVES INTO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM MONDAY...PATCHY LIGHT RAIN AND DRIZZLE ARE MOVING EAST TO WEST ACROSS THE FORECAST AREA THIS MORNING. RADAR LOOPS AND PROJECTIONS SHOW COVERAGE WILL INCREASE A BIT OVER THE NEXT FEW HOURS BEFORE FADING BY AROUND SUNRISE. AT THE SURFACE WE HAVE A LOW CENTER AND ASSOCIATED FRONTAL SYSTEM MOVING EAST UP THE COAST JUST OFFSHORE WHILE A COLD FRONT DESCENDS FROM THE NW. THIS COLD FRONT WILL MOVE OFFSHORE LATE THIS AFTERNOON OR EARLY EVENING AS THE OFFSHORE SYSTEM MOVES VERY QUICKLY NE TOWARDS NEW ENGLAND. ISENTROPIC LIFT ASSOCIATED WITH THE OFFSHORE SYSTEM BRINGING PRESENT ROUND OF MAINLY STRATIFORM PRECIPITATION...WHICH WILL END THIS MORNING AS THE SYSTEM EXITS TO THE NE. THE EXITING SYSTEM WILL PULL MUCH OF THE DEEP MOISTURE AWAY WITH IT...LEAVING LITTLE FOR THE COLD FRONT TO WORK WITH LATER ON TODAY. SKIES WILL GRADUALLY SCATTER OUT AS THE DAY WEARS ON. COOL AND DRY HIGH PRESSURE WILL FOLLOW FOR TONIGHT...NOSING IN FROM THE NW. TEMPERATURES WILL RETURN TO MORE SEASONAL LEVELS OVERNIGHT...WITH LOWS IN THE MID TO UPPER 40S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...VERY PROGRESSIVE PATTERN CONTINUES AS COOL AND DRY HIGH PRESSURE DROPS SOUTHEAST OVER THE FORECAST AREA TUESDAY AND WEDNESDAY...MOVING OFFSHORE WEDNESDAY NIGHT. ALTHOUGH WE WILL SEE A BIT OF A WARMING TREND....TEMPERATURES ON TUESDAY AND WEDNESDAY WILL BE WITHIN A FEW DEGREES OF CLIMO. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 300 AM MONDAY...A PATTERN CHANGE IS IN THE OFFING FOR THE EASTERN CAROLINAS DURING THE EXTENDED PERIOD. A DEEP MID LEVEL TROUGH OUT WEST WILL LINK UP WITH A DEVELOPING DEEP TROUGH FROM CANADA AND MOVE SLOWLY EASTWARD THROUGH THE PERIOD. A MOIST SOUTHWEST FLOW DEVELOPS THURSDAY THROUGH EARLY SATURDAY WITH THIS PATTERN. GUIDANCE CONTINUES TO ADVERTISE TWO PERIODS OF STRONGLY FORCED SHOWERS AND POSSIBLY EVEN THUNDER. THE FIRST ARRIVES LATE THURSDAY INTO EARLY FRIDAY WITH ANOTHER ROUND FRIDAY AFTERNOON INTO THE EVENING. WE CONTINUE TO ADVERTISE LIKELY POPS THROUGH THIS TIME FRAME WITH ACTIVITY COMING TO AN END EARLY SATURDAY. CLEARING AND COOLER LATE SATURDAY AND SUNDAY AS THE DEEP MID LEVEL TROUGH BRINGS ALONG WITH IT 850MB TEMPERATURES BRIEFLY JUST ABOVE FREEZING. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... AS OF 06Z... WHILE THERE ARE POCKETS OF CONVECTION ON RADAR PREDOMINATELY IT IS STRATIFORM RAIN AND WILL REMAIN SO FOR MOST OF THE OVERNIGHT HOURS. AS THE LOW APPROACHES HOWEVER...THERE MAY BE OCCASIONAL THUNDER...PARTICULARLY ALONG THE COAST OR OFFSHORE NEAR THE LOW`S TRACK. HAVE SLOWED THINGS DOWN AN HOUR OR TWO...BASED MAINLY ON THE HRRR MODEL. CEILINGS AND VISIBILITIES WILL BOUNCE AROUND A BIT...BUT WILL BE PREDOMINATELY IFR/LIFR. NOT VERY CONFIDENT ON ANY DENSE FOG...MAINLY BECAUSE THE WINDS WILL STAY AROUND 5 KTS OR BETTER. THE GFS SHUTS OFF THE MOISTURE BY 07Z...BUT THINK THIS IS A BIT FAST. LOOK FOR IMPROVING CONDITIONS AROUND DAYBREAK WITH VFR CONDITIONS SHORTLY AFTER WITH A WEST WIND. EXTENDED OUTLOOK...VFR THROUGH WEDNESDAY. MVFR SHOWERS AND CEILINGS POSSIBLE THURSDAY AND FRIDAY. FRIDAY MAY INCLUDE THUNDERSTORMS AS WELL. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM MONDAY...HAVE DROPPED SCEC HEADLINES WITH THE LATEST ISSUANCE AS OFFSHORE LOW IS MOVING NE ALMOST DIRECTLY OVER THE WATERS...KEEPING GRADIENT SLACKER THAN EXPECTED. THIS SYSTEM WILL MOVE RAPIDLY NE AS A COLD FRONT DESCENDS FROM THE NW. THE COLD FRONT WILL MOVE OFFSHORE LATE THIS AFTERNOON OR EARLY EVENING...FOLLOWED BY HIGH PRESSURE NOSING IN FROM THE NW OVERNIGHT. DO NOT EXPECT ANY FLAGS FOR THE NEAR TERM...BUT IT IS POSSIBLE WE COULD SEE GUSTY WINDS IN THE 20 TO 25 KT RANGE THIS AFTERNOON. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...MONDAY...HIGH PRESSURE WILL DOMINATE THE SHORT TERM AS IT MOVES OVERHEAD TUESDAY AND WEDNESDAY AND THEN EAST OF THE WATERS WEDNESDAY NIGHT. DO NOT EXPECT ANY HEADLINES FOR THIS PERIOD...ALTHOUGH SEAS MAY REMAIN ELEVATED AT 3 TO 5 FT EARLY IN THE PERIOD. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 300 AM MONDAY...EXTENDED MARINE FORECAST BRINGS RUGGED CONDITIONS TO ALL WATERS. A STRONG COLD FRONT WILL BRING SOUTH TO SOUTHWEST WINDS OF 20-25 KNOTS THURSDAY WELL INTO THE DAY FRIDAY. THE SPEEDS DO BACK OFF A LITTLE FRIDAY. LATE IN THE PERIOD THE FLOW WEAKENS FURTHER AS WINDS SHIFT TO THE WEST. SMALL CRAFT SEAS AND THEN SOME FOR MOST OF THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK NEAR TERM...REK SHORT TERM...REK LONG TERM...SHK AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1240 AM EDT MON MAR 28 2016 .SYNOPSIS... A STALLED FRONT ALONG THE COAST WILL MOVE INLAND THIS EVENING. LOW PRESSURE WILL MOVE NORTHEASTWARD ALONG THE FRONT AFTER MIDNIGHT...DRAGGING THE FRONT OFFSHORE. A COOLING AND DRYING TREND IS EXPECTED MONDAY THROUGH WEDNESDAY. WET CONDITIONS WILL RETURN LATE THURSDAY AND LINGER INTO THE WEEKEND AS ANOTHER COLD FRONT MOVES INTO THE AREA. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1230 AM MONDAY...HAVE SEEN A DRAMATIC DECREASE IN PRECIP COVERAGE OVER THE LAST HOUR WITH SOME PATCHY DRIZZLE AND LIGHT RAIN CONTINUING MAINLY ALONG THE COAST FROM CAPE FEAR AND NORTHWARDS. HAVE ADJUSTED FORECAST ACCORDINGLY. PREVIOUS DISCUSSION FOLLOWS: LINEAR EXTRAPOLATION OF THE RADAR-OBSERVED BACK EDGE OF THE RAIN SHIELD BRINGS IT TO DARLINGTON AROUND 05Z/1 AM EDT. THIS MATCHES UP FAIRLY WELL WITH THE EARLIER EVENING UPDATE AND ONLY SMALL CHANGES WERE NEEDED. NORTHERLY WINDS ARE BEING OBSERVED ALONG THE GEORGIA COAST AND OUT AS FAR EAST AS BUOY 41008. THIS IMPLIES THE SURFACE LOW MAY BE TAKING A TRACK A LITTLE FARTHER EAST FROM THE 18Z GFS/NAM CONSENSUS TRACK...AND I HAVE ADJUSTED HOURLY TEMPERATURE CURVES DOWN A DEGREE OR TWO SINCE THIS EASTWARD TRACK SHOULD REDUCE THE INFLOW OF WARM GULF STREAM AIR INTO COASTAL NORTH AND SOUTH CAROLINA. DISCUSSION FROM 730 PM FOLLOWS... AN UPPER DISTURBANCE ALONG THE GEORGIA-ALABAMA BORDER WILL SWEEP EAST TONIGHT...EXITING THE NC COAST BY DAYBREAK. SURFACE LOW PRESSURE IS ALREADY DEVELOPING NEAR JACKSONVILLE FLORIDA AND WILL MOVE NORTHEASTWARD ALONG THE CAROLINA COAST AFTER MIDNIGHT. UNTIL THE SURFACE LOW ARRIVES DEEP ISENTROPIC LIFT WILL CONTINUE AS GULF AND ATLANTIC MOISTURE ADVECTS ACROSS THE AREA. THE STRONGEST LIFT APPEARS TO EXIST ALONG THE 305K SURFACE...JUST BELOW 700 MB OR 10000 FEET ALOFT. IT IS ALONG THIS SURFACE THAT BOTH THE 18Z GFS AND NAM MODELS SHOW ISENTROPIC LIFT REMAINING STRONG THROUGH 2 AM EDT...LIKELY ACCOMPANIED BY SOLID RAINFALL. ELEVATED INSTABILITY IS VERY SMALL...ON THE ORDER OF 100 J/KG. THIS SHOULD HELP SUSTAIN CONVECTIVE SHOWERS EMBEDDED WITHIN THE STRATIFORM RAIN SHIELD. I HAVE TRIMMED BACK ISOLATED THUNDERSTORMS TO JUST THE COASTAL COUNTIES AND MARINE FORECAST ZONES WHERE INCREASING ADVECTION OF WARM AIR OFF THE GULF STREAM MAY PRODUCE SLIGHTLY LARGER SURFACE-BASED INSTABILITY LATER THIS EVENING. BY THE TIME THE PRECIPITATION TAPERS OFF LATE TONIGHT OVER AN INCH IS EXPECTED TO HAVE FALLEN ALONG THE COAST...WITH TOTALS CLOSER TO HALF AN INCH INLAND. IT IS INTERESTING TO SEE SLOW-MOVING CONVECTIVE SHOWERS ACROSS PORTIONS OF DARLINGTON AND MARLBORO COUNTIES RIGHT NOW THAT WILL LIKELY PRODUCE SMALL-SCALE AREAS OF RAINFALL TOTALS OVER AN INCH TOO. NO CHANGES HAVE BEEN MADE TO FORECAST LOWS...STILL ANTICIPATED TO FALL TO ONLY 60 BY DAYBREAK. TEMPERATURES MAY ACTUALLY RISE ALONG THE COAST OVER THE NEXT FEW HOURS DUE TO INCREASING GULF STREAM INFLUENCE AS THE LOW APPROACHES FROM THE SOUTH AND SOUTHERLY WINDS INCREASE. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...HIGHLIGHT THIS PERIOD IS DRYING TREND AND COOLING AS STORM SYSTEM EXITS NE AND HIGH PRESSURE BUILDS IN FROM THE WEST. GUSTY SHOWERS EARLY IN THE MORNING MONDAY ARE POSSIBLE AS INSTABILITY INCREASES BENEATH THE PASSING UPPER TROUGH. COOL AIR WILL LAG UNTIL COLD FRONTAL PASSAGE MONDAY NIGHT. THIS TRANSLATES TO A VERY MILD DAY MONDAY QUITE A BIT ABOVE NORMAL. MAXIMUMS 9-12 DEGREES COOLER UNDER SUNSHINE ON TUESDAY. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 300 PM SUNDAY...SURFACE AND MID LEVEL RIDGING IN THE AREA WED MORNING WILL KEEP THE REGION DRY WITH TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO. RETURN FLOW SETTING UP LATER IN THE DAY AS THE RIDGES MOVE OFFSHORE WILL COMMENCE OF A PERIOD OF STEADY MOISTURE RETURN. SHORTWAVE CROSSING THE UPPER MIDWEST DURING THE MIDDLE OF THE WEEK DEVELOPS A SURFACE LOW THAT MOVES INTO THE GREAT LAKES REGION THU. COLD FRONT TRAILING THIS LOW WILL MOVE INTO THE SOUTHEAST LATE IN THE WEEK. AHEAD OF THE FRONT DEEP SOUTHWEST FLOW WILL SPREAD GULF MOISTURE OVER THE REGION AND EJECT SHORTWAVES FROM THE BASE OF THE 5H TROUGH OVER THE SOUTHWESTERN CONUS. CONFIDENCE REMAINS LOW WITH RESPECT TO TIMING AND EVOLUTION OF THE MID LEVEL PATTERN BUT THE GFS...WHICH HAS CONSISTENTLY BEEN THE FASTEST SOLUTION...CONTINUES TO TREND SLOWER. CANADIAN/ECMWF/WPC SOLUTIONS REMAIN SLOWER AND ARE FAVORED. THIS IS NOT ONLY DUE TO THEIR AGREEMENT BUT WEAK MID LEVEL BLOCKING PATTERN WOULD SUGGEST SLOWER MOVEMENT OF ALL FEATURES. POP WILL STILL BE ON THE INCREASE THU BUT BEST CHANCES WILL BE THU NIGHT AND FRI/SAT. FRONT ENDS UP PARALLEL TO STEERING FLOW FRI/SAT WITH THE BOUNDARY SLOW TO CROSS THE AREA AND MOVE OFFSHORE. TEMPERATURES RUN ABOVE CLIMO THU-SAT DESPITE INCREASED CLOUD COVER AND RAIN CHANCES. SHORTWAVE CROSSING THE GULF COAST SAT NIGHT FINALLY PROVIDES THE KICK THE FRONT NEEDS...USHERING IN DRIER AIR AND TEMPERATURES NEAR CLIMO FOR THE START OF NEXT WEEK. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... AS OF 06Z... WHILE THERE ARE POCKETS OF CONVECTION ON RADAR PREDOMINATELY IT IS STRATIFORM RAIN AND WILL REMAIN SO FOR MOST OF THE OVERNIGHT HOURS. AS THE LOW APPROACHES HOWEVER...THERE MAY BE OCCASIONAL THUNDER...PARTICULARLY ALONG THE COAST OR OFFSHORE NEAR THE LOW`S TRACK. HAVE SLOWED THINGS DOWN AN HOUR OR TWO...BASED MAINLY ON THE HRRR MODEL. CEILINGS AND VISIBILITIES WILL BOUNCE AROUND A BIT...BUT WILL BE PREDOMINATELY IFR/LIFR. NOT VERY CONFIDENT ON ANY DENSE FOG...MAINLY BECAUSE THE WINDS WILL STAY AROUND 5 KTS OR BETTER. THE GFS SHUTS OFF THE MOISTURE BY 07Z...BUT THINK THIS IS A BIT FAST. LOOK FOR IMPROVING CONDITIONS AROUND DAYBREAK WITH VFR CONDITIONS SHORTLY AFTER WITH A WEST WIND. EXTENDED OUTLOOK...VFR THROUGH WEDNESDAY. MVFR SHOWERS AND CEILINGS POSSIBLE THURSDAY AND FRIDAY. FRIDAY MAY INCLUDE THUNDERSTORMS AS WELL. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1230 AM MONDAY...NO SIGNIFICANT CHANGES WERE NEEDED WITH THE LATEST UPDATE. DISCUSSION FROM 730 PM FOLLOWS: LOW PRESSURE DEVELOPING NEAR JACKSONVILLE FLORIDA WILL MOVE NORTHEASTWARD ALONG THE CAROLINA COAST OVERNIGHT...BRINGING WIDESPREAD RAIN WITH EMBEDDED THUNDERSTORMS POSSIBLE LATER THIS EVENING. EASTERLY WINDS 10-15 KT WILL TURN SOUTHERLY AND MAY INCREASE TO A SOLID 20 KNOTS ACROSS THE NC WATERS AFTER MIDNIGHT AS THE LOW MOVES ACROSS THE AREA. THIS NECESSITATES THE EXERCISE CAUTION HEADLINE ALREADY IN PLACE. SEAS CURRENTLY 2-3 FEET WILL BUILD TO 3-5 FEET DUE TO THE PERIOD OF STRONGER SOUTH WINDS EXPECTED TO DEVELOP. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...A ROUGH START UNDER EXERCISE CAUTION CONDITIONS FOR GUSTY WEST WINDS EARLY MONDAY...BUT A NICE IMPROVING TREND AFTER THAT AS HIGH PRESSURE FROM THE WEST NEARS THE COAST...MAKING FOR NICE MARINE CONDITIONS TUESDAY. NE WINDS WILL INCREASE A BIT TUESDAY NIGHT AS HIGH PRESSURE TO THE NORTH STRENGTHENS SOUTHWARD. 3-5 FT SEAS INITIALLY EASING TO 2 TO 4 FT DURING TUESDAY. LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 300 PM SUNDAY...SURFACE HIGH CENTERED NORTH OF THE WATERS WED MORNING WILL DRIFT EAST DURING THE DAY WITH NORTHEAST FLOW DROPPING TO 10 KT OR LESS AND BECOMING EASTERLY IN THE AFTERNOON. SURFACE HIGH PUSHES FARTHER EAST THU WITH GRADIENT TIGHTENING AHEAD OF NEXT SYSTEM. SOUTHERLY FLOW INCREASES WITH SPEEDS APPROACHING 20 KT IN THE AFTERNOON. ALTHOUGH WIND SPEEDS MAY FALL SHORT OF 25 KT THE INCREASING SOUTHERLY FLOW MAY PUSH SEAS OVER 6 FT AND AN SCA FOR THU OR THU NIGHT SEEMS PROBABLE. FURTHER STRENGTHENING OF SOUTHERLY FLOW IS EXPECTED FRI WITH POTENTIAL FOR 20 TO 25 KT IN THE AFTERNOON. SEAS WILL REMAIN ABOVE SCA THRESHOLDS FRI AND FRI NIGHT WITH POTENTIAL FOR DOUBLE DIGIT WAVE HEIGHTS SOUTHEAST OF BALD HEAD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MJC NEAR TERM...REK/TRA SHORT TERM...MJC LONG TERM...III AVIATION...DL MARINE...MJC/REK/TRA/III
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1247 AM CDT MON MAR 28 2016 .UPDATE... ISSUED AT 1233 AM CDT MON MAR 28 2016 FOR THIS UPDATE INCREASED OVERNIGHT LOW TEMPERATURES ACROSS THE REGION. WITH MOIST EASTERLY FLOW DEWPOINTS WILL BE INCREASING...AS WELL AS CLOUD COVER. THIS WILL LIMIT HOW FAR TEMPERATURES FALL TONIGHT. UPDATE ISSUED AT 934 PM CDT SUN MAR 27 2016 THE 00-01 UTC HRRR AND RAP ITERATIONS SUGGEST FOG DEVELOPMENT ALONG THE MISSOURI COTEAU OF NORTHWEST AND CENTRAL NORTH DAKOTA LATE TONIGHT INTO MONDAY MORNING WITH EASTERLY UPSLOPE FLOW...AND ADDED A MENTION INTO THE FORECAST. UPDATE ISSUED AT 723 PM CDT SUN MAR 27 2016 NO CHANGES REQUIRED OTHER THAN TO BLEND TO OBSERVED TRENDS...WITH MULTIPLE FLOCKS OF BIRDS LAUNCHING FROM AREA LAKES AND REFUGES CLEARING EVIDENT ON RADAR THROUGH 0044 UTC. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 310 PM CDT SUN MAR 27 2016 AT 3 PM CDT...A WEAK COLD FRONT ACROSS CENTRAL NORTH DAKOTA WILL CONTINUE MOVING SLOWLY SOUTH TONIGHT. A WARM H850 THERMAL RIDGE ACROSS SOUTHERN NORTH DAKOTA AND RESULTED IN MILD TEMPERATURES CLOSE TO 60 THIS AFTERNOON ACROSS SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA. ONCE THE CONVECTIVE TEMPERATURE WAS HIT QUITE A BIT OF STRATO-CU FORMED AND SCATTERED TO ISOLATED SHOWERS OR SPRINKLES FORMED ACROSS WEST AND CENTRAL NORTH DAKOTA. THIS WILL END BY EARLY EVENING. TONIGHT...THE COLD FRONT WILL SLIP SOUTH AND WASH OUT AS INCREASING SOUTHEAST WINDS DEVELOP BY MORNING. SKIES WILL BE CLEAR TO PARTLY CLOUDY. ON MONDAY...SOUTHEAST WINDS WILL PULL INCREASING LOW LEVEL MOISTURE INTO THE REGION. HIGHS ON MONDAY WILL BE SIMILAR TO TODAY WITH HIGHS IN THE 50S TO AROUND 60. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 310 PM CDT SUN MAR 27 2016 AN ACTIVE LONG TERM PERIOD REMAINS ON TRACK. BEST MOISTURE POTENTIAL OCCURS WITH THE INITIAL SYSTEM LATE TUESDAY THROUGH WEDNESDAY MAINLY ACROSS SOUTHERN NORTH DAKOTA WITH A COMBINATION OR RAIN THEN SNOW. THEREAFTER...GRADUALLY TURNING COLDER WITH WINDY CONDITIONS AND POTENTIAL FOR SNOW/BLOWING SNOW ESPECIALLY WEDNESDAY NIGHT THROUGH THURSDAY. TEMPERATURES TRENDING BELOW AVERAGE MID TO LATE WEEK. THE LATEST WATER VAPOR IMAGERY SHOWS A STRONG JET (120KT) WEST OF THE BRITISH COLUMBIA COAST DIVING SOUTH WITH TIME. THIS IS HELPING TO STRENGTHEN/DEEPEN AN UPPER TROUGH IN THE PACIFIC NORTHWEST. IN DOING SO...AN AMPLIFYING UPPER RIDGE WILL TAKE SHAPE WITH SHARPLY RISING HEIGHTS WITH ITS RIDGE AXIS EXTENDING THROUGH BRITISH COLUMBIA AND INTO NORTHERN ALASKA MIDWEEK. THIS WILL PLAY A KEY ROLE IN ESTABLISHING A COOLING TREND BY MID TO LATE WEEK ACROSS NORTH DAKOTA. THE UPPER RIDGE IS FORECAST TO BREAK DOWN NEXT WEEKEND...SO THE COLDER AIR BEYOND SATURDAY SHOULD SUBSIDE AND BEGIN TO MODERATE. MONDAY NIGHT THROUGH WEDNESDAY...THE MAIN HIGHLIGHT EARLY IN THE PERIOD WILL BE CHANCES OF RAIN TUESDAY EVENING...THEN TRANSITIONING TO SNOW TUESDAY NIGHT AND WEDNESDAY. FOR WESTERN AND CENTRAL NORTH DAKOTA AT THIS TIME...ALL DISCUSSIONS AND MODEL SOLUTIONS DEPEND UPON HOW AN OPEN NORTHERN STREAM UPPER TROUGH WILL INTERACT WITH AN EJECTING UPPER/SURFACE COLORADO LOW MONDAY. MODEL CONSENSUS CONTINUES TO ADVERTISE THE HIGHEST IMPACT RESIDES ACROSS SOUTHERN NORTH DAKOTA WITH MUCH LESSER PRECIPITATION NORTH. A DEFORMATION ZONE SETS UP OVER NORTHERN SOUTH DAKOTA INTO SOUTHERN NORTH DAKOTA LATE TUESDAY INTO WEDNESDAY...AS THE H7-H5 UPPER LEVEL LOW TRANSLATES FROM COLORADO TO NEBRASKA AND THEN INTO THE GREAT LAKES. THE BEST FORCING...MID LEVEL FRONTOGENESIS/Q VECTOR DIVERGENCE/LAPSE RATES...ALL COINCIDE TOGETHER WITHIN THIS DEFORMATION ZONE AREA TUESDAY NIGHT...THEN SHIFTS INTO THE SOUTHERN JAMES RIVER VALLEY WEDNESDAY MORNING. BUFKIT SOUNDING PROFILES TUESDAY EVENING WARM ENOUGH FOR RAIN...THEN TRANSITIONING TO SNOW TUESDAY NIGHT. SOME CONCERN AT THIS TIME IS THE POTENTIAL FOR SNOW/BLOWING SNOW AND A PERIOD OF LOWER VISIBILITIES FROM 12Z WEDNESDAY UNTIL 18Z WEDNESDAY ACROSS THE SOUTHERN JAMES RIVER. STRONG FORCING EARLY WEDNESDAY MORNING ALONG WITH BOUNDARY LAYER WINDS OF 35KT PER GFS AND NAM...BUT MUCH WEAKER PER ECMWF...MAY RESULT IN LOW VISIBILITIES IN FALLING SNOW IN THE FAR SOUTHERN JAMES RIVER VALLEY BEFORE THE MAIN SHIELD OF SNOW ENDS BY AROUND 18Z. WPC LIQUID PRECIPITATION AMOUNTS RANGE BETWEEN 0.25 AND 0.50 INCHES MAINLY ALONG AND SOUTH OF INTERSTATE 94 TUESDAY THROUGH WEDNESDAY MORNING. THESE AMOUNTS WILL BE A COMBINATION OF RAIN AND SNOW...WITH WPC FORECAST SNOWFALL AMOUNTS OF 1 TO 2 INCHES ALONG AND SOUTH OF I-94 VALID BETWEEN TUESDAY EVENING AND WEDNESDAY EVENING. AS THE SURFACE LOW TRANSLATES ACROSS CENTRAL/EASTERN SOUTH DAKOTA AND INTO MINNESOTA TUESDAY NIGHT INTO WEDNESDAY...DECENT INSTABILITY DEVELOPS TUESDAY EVENING IN CENTRAL/SOUTHERN SOUTH DAKOTA WITHIN THE DEFORMATION ZONE AREA. THIS AREA OF INSTABILITY CURRENTLY FALLS SHY OF REACHING SOUTHERN NORTH DAKOTA...HOWEVER THIS WILL NEED MONITORING AS ANY SHIFT NORTH COULD PUT THE SOUTHERN PORTION IN A MENTION OF THUNDERSTORMS. FOR NOW...NO MENTION OF THUNDERSTORMS. WEDNESDAY NIGHT THROUGH SATURDAY NIGHT...A STRONG UPPER RIDGE IN BRITISH COLUMBIA MENTIONED ABOVE WITH A COMPENSATORY STRONG NORTHERLY TO NORTHWEST FLOW INTO NORTH DAKOTA CAN BE EXPECTED DURING THIS TIME PERIOD. THE GFS AND ECMWF IN GOOD AGREEMENT WITH TWO COLD FRONTS SWEEPING THROUGH. THE INITIAL COLD FRONT WILL GENERATE GUSTY WINDS...LIGHT SNOW...AND BLOWING SNOW. CONCERN WILL BE SNOW/BLOWING SNOW AS BOUNDARY LAYER WINDS OF 30-35KT ARE FORECAST TO ACCOMPANY THE COLD FRONT AND SNOW. AFTER COORDINATION WITH RAPID CITY AND ABERDEEN FORECAST OFFICES...HAVE INCREASED WINDS BETWEEN 5 AND 10KT OVER WHAT OUR MODEL SOLUTIONS PROVIDED WEDNESDAY INTO THURSDAY. IN ADDITION...HAVE COORDINATED WITH SURROUNDING OFFICES AND ADJUSTED MAX TEMPERATURES DOWNWARD BY 5 TO 8 DEGREES THURSDAY WITH ONGOING COLD AIR ADVECTION AND H85 TEMPS TAKING A TREND TOWARD THE -4C TO -8C DURING THE DAY. THIS SHOULD RESULT IN MOSTLY LIGHT SNOW RATHER THAN RAIN. GFS BUFKIT SOUNDINGS SUPPORT THIS AS WELL. THE WIND AND SNOW END THURSDAY NIGHT WITH WARM AIR ADVECTION COMMENCING FRIDAY AHEAD OF OUR NEXT COLD FRONT. THIS SECOND COLD FRONT APPEARS TO HAVE LESS WIND AND SNOW WITH IT AS IT PUSHES FROM NORTH TO SOUTH FRIDAY NIGHT THROUGH SATURDAY. HOWEVER H85 TEMPS ARE COLDER...RANGING BETWEEN 0C IN THE SOUTHWEST TO -16C IN THE TURTLE MOUNTAINS. HIGH TEMPERATURES IN THE 50S TO AROUND 60F TUESDAY WILL BE REPLACED WITH 40S WEDNESDAY THROUGH SATURDAY. HOWEVER...EXPECT HIGHS IN THE 30S TO AROUND 40F THURSDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1233 AM CDT MON MAR 28 2016 MVFR/IFR FOG AND STRATUS MAY BUILD INTO KMOT AND KJMS LATE TONIGHT INTO MONDAY MORNING. KBIS IS FORECAST TO REMAIN ON THE WESTERN FRINGE OF THIS POSSIBLE FOG AND STRATUS BANK...AND WILL LEAVE OUT OF THE FORECAST FOR NOW. HOWEVER...THIS WILL HAVE TO BE MONITORED THROUGH THE NIGHT. VFR CONDITIONS ARE FORECAST AT KISN AND KDIK. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AJ SHORT TERM...WAA LONG TERM...KS AVIATION...TWH
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
604 PM EDT MON MAR 28 2016 .SYNOPSIS... DEEPENING LOW PRESSURE JUST NORTH OF NEW YORK STATE WILL MOVE OFF THE EAST COAST BY MORNING. HIGH PRESSURE OVER THE MISSISSIPPI VALLEY WILL MOVE EAST OVER THE AREA ON TUESDAY...THEN SHIFT TO THE MID ATLANTIC COAST ON WEDNESDAY. LOW PRESSURE WILL CROSS THE GREAT LAKES THURSDAY WITH THE ASSOCIATED COLD FRONT CROSSING THE AREA LATE THURSDAY OR THURSDAY NIGHT. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... THE WIND IS CONTINUING TO DIMINISH. LOOKS LIKE THERE IS ONE MORE TRAILING SHORT WAVE OVER THE NORTHERN PART OF THE LAKES THAT WILL DIVE SE ACROSS THE SNOWBELT THE 2ND HALF OF THE NIGHT. THE DEEPER MOISTURE WILL BE GONE BY THE TIME THE S/W ARRIVES. THE NEAR TERM HRRR AND RAP PRODUCE A LITTLE BIT OF QPF TONIGHT...MOSTLY UNTIL 06Z. THUS...WILL KEEP SLIGHT CHC POP FOR THIS POSSIBILITY. QUESTION IS PRECIP TYPE AS LACK OF DEEP MOISTURE COULD MEAN SPRINKLES VERSUS FLURRIES OR LIGHT SNOW SHOWERS. THINK TEMPS WILL TRY AND STAY ABOVE FREEZING AS LONG AS THE CLOUD COVER PERSISTS SO DON`T THINK A PROBLEM WITH FREEZING TYPE OF PRECIP WILL DEVELOP. THE BACK EDGE OF THE STRATOCUMULUS DECK SHOULD REACH NORTHWEST OHIO DURING THE EARLY MORNING HOURS. IT MAY STAY CLOUDY/MOSTLY CLOUDY ELSEWHERE. THE WIND AND CLOUDS WILL KEEPS TEMPS FROM CRASHING. LOWS GENERALLY IN THE LOWER/MID 30S...MAYBE SOME UPPER 20S IN THE COLDER SECTIONS OF INLAND NW PA. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... HIGH PRESSURE WILL BEGIN TO MOVE ACROSS THE AREA ON TUESDAY. WHAT REMAINS OF THE LAKE CLOUDS WILL SHIFT INLAND AND GRADUALLY MIX AWAY. TEMPERATURES WILL RANGE FROM 50 ACROSS NORTHWEST OHIO TO THE UPPER 30S/AROUND 40 NORTHWEST PA. THE SURFACE HIGH WILL MOVE EAST OF THE AREA TUESDAY NIGHT. TEMPS WILL DROP OFF IN THE EVENING AND IT WILL GET CHILLY ESPECIALLY ACROSS NORTHEAST OHIO AND NORTHWEST PA. TEMPS SHOULD LEVEL OFF OR COULD BEGIN TO RISE ELSEWHERE AS THE SOUTH FLOW BEGINS TO PICK UP EARLY WEDNESDAY. WE SHOULD SEE A VARIETY OF MID AND HIGH CLOUDS WEDNESDAY MIXED WITH SOME SUNSHINE. OUR WARM UPS HAVE BEEN FAST AND FURIOUS THIS SPRING AND WILL NOT UNDERCUT GUIDANCE OF LOWER 60S MOST AREAS. ANOTHER COLORADO LOW EXPECTED TO EJECT OUT ACROSS THE PLAINS STATES WEDNESDAY INTO THURSDAY. MOST OF THE MODELS SHOWING A NICE PLUME OF GULF MOISTURE AND UPWARD MOTION WELL AHEAD OF THE LOW IN THE DEVELOPING JET AS A NORTHERN SHORT WAVE TRIES TO PHASE WITH THE SOUTHERN BRANCH SHORT WAVE. NO WAY TO KNOW HOW MUCH THINGS WILL PHASE BUT IT SEEMS REASONABLE TO FORECAST AN INCREASING CHANCE OF SHOWERS WEDNESDAY NIGHT INTO EARLY THURSDAY. AT THIS TIME WILL NOT MENTION THUNDERSTORMS IN THE WARM ADVECTION SHOWERS WEDNESDAY NIGHT OR EARLY THURSDAY ALTHOUGH IT IS CERTAINLY NOT OUT OF THE QUESTION. AS THE COLD FRONT APPROACHES LATER THURSDAY THERE MAY BE A BETTER CHANCE FOR THUNDER GIVEN THE WARMER AND MORE UNSTABLE ATMOSPHERE IN THE WARM SECTOR AND THE TIME OF DAY. HIGHS AT LEAST IN THE MID 60S AND IT COULD BE ANOTHER OF THOSE DAYS WHERE TEMPERATURES SNEAK TO 70 IF WE CAN GET SOME SUNSHINE AND SEVERAL HOURS OF DRY WEATHER. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS UPPER LEVEL RIDGE BEGINS TO AMPLIFY IN THE WESTERN UNITED STATES THIS MEANS ONLY ONE THING FOR THE EAST. DEEP DIGGING UPPER LEVEL TROUGH DEVELOPS ALLOWING COLDER AIR TO RETURN TO THE FORECAST AREA FOR THE WEEKEND. THE UPPER LEVEL TROUGH BEGINS TO PULL OUT TO THE EAST DURING THE LATTER HALF OF THE WEEKEND BRINGING AN END TO THE COLD AIR ADVECTION AND THE BEGINNINGS OF ANOTHER WARM AIR ADVECTION PATTERN. SURFACE LOW PRESSURE WILL PULL OUT TO THE EAST FRIDAY ALLOWING A BROAD SOMEWHAT DISORGANIZED AREA OF HIGH PRESSURE TO BUILD EAST INTO THE FORECAST AREA BY FRIDAY EVENING. HOWEVER...AS UPPER LEVEL TROUGH REMAINS PRESENT ALONG WITH SHOTS OF POSITIVE VORTICITY ADVECTION...CANT RULE OUT THE POSSIBILITY FOR SOME SCATTERED SHOWER ACTIVITY. SOME SNOW COULD MIX IN WITH THE RAIN OVER THE NORTHEAST AS COLD AIR ADVECTION CONTINUES TO DEVELOP. UNFORTUNATELY...AS LONG AS THE UPPER LEVEL TROUGH LINGERS ACROSS THE AREA...MOISTURE WILL ALSO REMAIN PRESENT AND WILL KEEP A MINIMAL CHANCE OF RAIN AND/OR SNOW ACROSS THE REGION. THEN...BY MONDAY...A WARM FRONT TRIES TO LIFT NORTH ACROSS THE FORECAST AREA BUT MODELS SO FAR KEEP THE FRONT JUST SOUTH OF THE AREA DURING THE DAY MONDAY. NOT LOOKING AT ANY BIG WARM-UPS IN THIS FORECAST PERIOD. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... DEEP LOW PRESSURE PULLING OUT TO THE EAST AND NORTH OF LAKE ONTARIO AT THIS TIME. PRECIPITATION ASSOCIATED WITH THE STORM SYSTEM WILL ALSO EXIT TO THE EAST AS WELL THIS AFTERNOON. WRAP AROUND MOISTURE WILL CONTINUE TO STREAM INTO THE LOCAL AREA AND THIS WILL CONTINUE TO CAUSE SOME LOW LEVEL CLOUDINESS THROUGH MUCH OF THE NIGHT. EVENTUALLY CLEARING TAKES PLACE FROM WEST TO EAST TOMORROW. WINDS WILL BE GRADUALLY DIMINISHING AS WELL. OUTLOOK...NON VFR WEDNESDAY NIGHT INTO THURSDAY. NON VFR POSSIBLE FRIDAY AND LATE SATURDAY. && .MARINE... WINDS WILL BE DIMINISHING OVERNIGHT AND WILL LIKELY ALLOW GALES AND SMALL CRAFT ADVISORIES TO BE DISCONTINUED. I THINK THE SMALL CRAFT CONDITIONS WILL SUBSIDE EARLY THIS EVENING BUT WILL KEEP THE ADVISORY GOING UNTIL 9 PM. LATER SHIFT CAN GO AHEAD AND DROP IT AS APPROPRIATE. AS LOW PRESSURE SYSTEM PULLS OUT TO THE EAST OF THE AREA...GUSTY WINDS WILL CONTINUE ACROSS THE EAST OF THE LAKE AND THEREFORE WILL LEAVE THE GALE WARNING UP THIS EVENING. WINDS WILL BECOME FAIRLY LIGHT FOR TUESDAY AND VARIABLE. WINDS SHOULD REMAIN THAT WAY THROUGH TUESDAY NIGHT AND THEN INCREASE OUT OF THE SOUTH SLIGHTLY OVER THE LAKE WEDNESDAY. COLD DOME WILL LIKELY KEEP THE STRONGER WINDS OVER LAND RATHER THAN OVER THE WATER. EVENTUALLY WINDS WILL INCREASE WEDNESDAY NIGHT AND OVERCOME THE COLD DOME ALLOWING STRONGER WINDS TO 25 KNOTS TO MIX TO THE SURFACE. THE WINDS FINALLY SHIFT AROUND TO THE WEST BY FRIDAY AND BEGIN TO DIMINISH. HOWEVER...THIS WILL BE SHORT LIVED AS WINDS INCREASE OUT OF THE WEST SATURDAY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...GALE WARNING UNTIL 9 PM EDT THIS EVENING FOR LEZ061-148-149- 168-169. SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR LEZ142>147. && $$ SYNOPSIS...KOSARIK NEAR TERM...KOSARIK/ADAMS SHORT TERM...KOSARIK LONG TERM...LOMBARDY AVIATION...LOMBARDY MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1016 AM EDT MON MAR 28 2016 .SYNOPSIS... COLD FRONT EXITS EARLY THIS MORNING. COOLER WITH LOW LEVEL MOISTURE LINGERING INTO TONIGHT. HIGH PRESSURE TUESDAY. WARMER WEDNESDAY. LOW PRESSURE/FRONT THURSDAY. COOLER AIR OVER WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... 1000 AM UPDATE... COLD FRONT HAS PUSHED E OF THE AREA THIS MORNING...CURRENTLY EXITING THE BLUE RIDGE. AS IT CROSSED STRONG GUSTY WINDS WERE NOTED IN THE N MOUNTAINS WITH UNOFFICIAL OBS AT SNOWSHOE OF GUSTS TO 65 MPH. IN ITS WAKE AN ABUNDANCE OF STRATUS EXISTS AND WITH CAA CONTINUING THROUGHOUT TODAY AND THIS EVENING...SEE NO REASON FOR AND IMPROVING SKY. ALSO OF NOTE IS THE POTENTIAL FOR STRONG GUSTY WINDS CONTINUING OVER THE MOUNTAINS. H85 WINDS HOVER IN THE 40 TO 45 KT RANGE AND WITH CAA AIDING IN MOMENTUM TRANSFER...FEEL THE HIGHER ELEVATIONS...IE ABOVE 3500 FEET...ARE IN STORE FOR 40 TO 50 MPH GUSTS THROUGHOUT THE DAY. WE HAVE ISSUED AN SPS TO HIGHLIGHT THIS AS COUNTY WIDE AVERAGE CRITERIA IS NOT EXPECTED TO BE MET FOR A WIND ADVISORY AS THE LOWER ELEVATIONS SHOULD KEEP THERE GUSTS BELOW 40 MPH GENERALLY SPEAKING. KEPT POPS TODAY CONFINED TO THE N MOUNTAIN COUNTIES WITH AN UPTICK THIS AFTERNOON AND EVENING. TEMPS TODAY LOOK TO BE NEARLY STEADY STATE OVER THE LOWLANDS WITH THE MOUNTAINS SEEING A BIT OF A FALL AS THE DAY PROGRESSES. PREVIOUS DISCUSSION BELOW... VIGOROUS UPPER LEVEL S/W TROUGH PUSHES THROUGH THE AREA THIS MORNING...WITH WINDS DIMINISHING JUST A BIT BUT REMAINING GUSTY THROUGH THE AFTERNOON AND EVEN INTO THIS EVENING. RAIN SHOWERS WILL MOVE OUT OF THE AREA FIRST THING THIS MORNING BUT UPSLOPE FLOW WILL KEEP SHOWERS GOING IN THE MOUNTAINS. THESE SHOWERS WILL END AS SNOW SHOWERS ACROSS THE HIGHER TERRAIN TOWARD DAWN TUE. IT APPEARS STRATOCU BEHIND THE COLD FRONT WILL BE QUITE TENACIOUS TODAY AND EVEN TONIGHT...WITH ABOUT A 100MB THICK MOIST LAYER TRAPPED BELOW THE FRONTAL INVERSION. EVEN NOTORIOUSLY LOW MAV IS ABOVE FREEZING ALL BUT THE HIGHER TERRAIN TONIGHT...SO WILL NIX HWO MENTION OF FREEZE WHERE GROWING SEASON HAS BEEN STARTED...IN KY...FOR TONIGHT AND EARLY TUE MORNING. PREFERRED THE LOWER RUC FOR TEMPERATURES TODAY UNDER THE OVERCAST. EVEN WITH BLENDING IN THE LOWEST OF THE GUIDANCE OPTIONS...THE BIAS CORRECTED MAV...LOWS TONIGHT ARE A BIT HIGHER THAN PREVIOUS PACKAGE FOR THE MOST PART GIVEN THE CLOUD COVER. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... GUIDANCE IS IN FAIRLY GOOD AGREEMENT WITH OVERALL PATTERN FOR THE SHORT TERM PERIOD WITH ONLY SOME MINOR TIMING ISSUES FOR PRECIP ARRIVAL THURSDAY MORNING. HIGH PRESSURE MOVES OVERHEAD TUESDAY AND BRINGS DRY...BUT COOL CONDITIONS. EVEN THOUGH WARM AIR ADVECTION WILL BEGIN ALOFT ON TUESDAY NIGHT...CLEAR SKIES AND LIGHT WINDS SHOULD MAKE FOR EFFICIENT RADIATIONAL COOLING. DECIDED TO GO SLIGHTLY BELOW GUIDANCE FOR LOW TEMPS ESPECIALLY IN THE ISOLD VALLEYS...WHERE LOWS WILL LIKELY DROP BELOW FREEZING. HIGH PRESSURE SLIDES TO OUR EAST AND WARM AIR ADVECTION WITH RETURN FLOW WILL SHOOT OUR TEMPS BACK UP INTO THE 70S...FOR ANOTHER GREAT SPRING DAY. COLD FRONT WILL APPROACH LATE WEDNESDAY NIGHT WITH A WARM FRONT PUSHING THROUGH EARLY THURSDAY MORNING. COULD SEE SOME SHOWERS WITH THE WARM FRONT DURING THE MORNING HOURS...BUT THE HEAVIER PRECIP AND CONVECTION WILL HOLD OFF UNTIL LATER THURSDAY WITH THE PASSING OF THE COLD FRONT...AS EXPLAINED IN THE LONG TERM DISCUSSION BELOW. && .LONG TERM /THURSDAY THROUGH SUNDAY/... THE AREA WILL REMAIN IN THE WARM SECTOR OF A SFC LOW PRESSURE WITH POSSIBLE CONVECTION AHEAD OF A COLD FRONT THROUGH LATE THURSDAY. THEREFORE...KEPT LIKELY POPS FOR THURSDAY. MODELS SHOW LOW SFC CAPE AND HIGH DEEP LAYERED SHEAR ENVIRONMENT WITH PRECIPITABLE WATER UP TO 1.25 INCHES. THESE PARAMETER COULD ALLOW THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON HOURS. THEREFORE...KEPT THUNDER UNDER LIKELY POPS FOR THURSDAY. BY 12Z FRIDAY...THE FRONT WILL BE JUST EAST OF THE APPALACHIANS...BUT A SECONDARY FRONT WILL REINFORCE THE COLD AIR. THE AREA REMAINS UNDER NORTHWEST FLOW THROUGH THE WEEKEND. ANOTHER BUT FASTER SYSTEM CROSS THE GREAT LAKES SATURDAY. USED THE WPC GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... ACTIVE COLD FRONT PUSHING THROUGH THE WV MOUNTAINS EARLY THIS MORNING. EKN WILL BE THE LAST OF THE SIX AREA TAF SITES THE FRONT CROSSES EARLY THIS MORNING...IT SHOULD JUST ABOUT BE THROUGH THERE AS OF 12Z. GUSTY W WINDS WILL BE DIMINISHING FROM W TO E...AS AS THE RAIN SHOWERS MOVE OUT BUT MVFR CIGS SETTLE IN. WHILE THERE MAY BE A FEW VFR HOLES FOR A SHORT TIME THIS MORNING...THESE MVFR CIGS ARE LIKELY TO PERSIST THROUGHOUT THE TAF PERIOD...12Z TUE. GUSTY W TO NW SFC WINDS TODAY WILL GRADUALLY DIMINISH TONIGHT. MODERATE TO STRONG W FLOW ALOFT EARLY THIS MORNING...WILL GRADUALLY BECOME NW TODAY...AND THEN GRADUALLY DIMINISH TONIGHT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING AND EXTENT OF IFR CIGS IN MOUNTAINS MAY VARY...AS MAY TIMING OF MVFR CIGS OTHERWISE. CIGS COULD BREAK UP OVERNIGHT TONIGHT. GUSTY WINDS WILL VARY TODAY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 12 13 14 15 16 17 18 19 20 21 22 23 EDT 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19 CRW CONSISTENCY M M M M M M M M H H H H HTS CONSISTENCY M M M M M M M M H H H H BKW CONSISTENCY M M M M M M M M M M M M EKN CONSISTENCY M M M M M M M M M M M M PKB CONSISTENCY M M M M M M M M M M M M CKB CONSISTENCY M M M M M M M M M M M M AFTER 12Z TUESDAY... IFR POSSIBLE IN STRATUS TUE MORNING...MAINLY IN THE MOUNTAINS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...TRM/MPK NEAR TERM...TRM/30 SHORT TERM...MPK LONG TERM...ARJ AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
643 AM EDT MON MAR 28 2016 .SYNOPSIS... COLD FRONT EXITS EARLY THIS MORNING. COOLER WITH LOW LEVEL MOISTURE LINGERING INTO TONIGHT. HIGH PRESSURE TUESDAY. WARMER WEDNESDAY. LOW PRESSURE/FRONT THURSDAY. COOLER AIR OVER WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... 630 AM UPDATE... RDA STILL OTS. FCST ON TRACK WITH COLD FRONT NEAR A CKB TO BKW LINE. PREV DISCN... RADAR IS OTS AND TECHS WERE BEING CONTACTED. COLD FRONT WAS BLOWING THROUGH THE AREA EARLY THIS MORNING WITH GUSTY SHOWERS IMMEDIATELY AHEAD OF IT AND GUSTY NW WINDS IMMEDIATELY BEHIND IT. VIGOROUS UPPER LEVEL S/W TROUGH PUSHES THROUGH THE AREA THIS MORNING...WITH WINDS DIMINISHING JUST A BIT BUT REMAINING GUSTY THROUGH THE AFTERNOON AND EVEN INTO THIS EVENING. RAIN SHOWERS WILL MOVE OUT OF THE AREA FIRST THING THIS MORNING BUT UPSLOPE FLOW WILL KEEP SHOWERS GOING IN THE MOUNTAINS. THESE SHOWERS WILL END AS SNOW SHOWERS ACROSS THE HIGHER TERRAIN TOWARD DAWN TUE. IT APPEARS STRATOCU BEHIND THE COLD FRONT WILL BE QUITE TENACIOUS TODAY AND EVEN TONIGHT...WITH ABOUT A 100MB THICK MOIST LAYER TRAPPED BELOW THE FRONTAL INVERSION. EVEN NOTORIOUSLY LOW MAV IS ABOVE FREEZING ALL BUT THE HIGHER TERRAIN TONIGHT...SO WILL NIX HWO MENTION OF FREEZE WHERE GROWING SEASON HAS BEEN STARTED...IN KY...FOR TONIGHT AND EARLY TUE MORNING. PREFERRED THE LOWER RUC FOR TEMPERATURES TODAY UNDER THE OVERCAST. EVEN WITH BLENDING IN THE LOWEST OF THE GUIDANCE OPTIONS...THE BIAS CORRECTED MAV...LOWS TONIGHT ARE A BIT HIGHER THAN PREVIOUS PACKAGE FOR THE MOST PART GIVEN THE CLOUD COVER. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... GUIDANCE IS IN FAIRLY GOOD AGREEMENT WITH OVERALL PATTERN FOR THE SHORT TERM PERIOD WITH ONLY SOME MINOR TIMING ISSUES FOR PRECIP ARRIVAL THURSDAY MORNING. HIGH PRESSURE MOVES OVERHEAD TUESDAY AND BRINGS DRY...BUT COOL CONDITIONS. EVEN THOUGH WARM AIR ADVECTION WILL BEGIN ALOFT ON TUESDAY NIGHT...CLEAR SKIES AND LIGHT WINDS SHOULD MAKE FOR EFFICIENT RADIATIONAL COOLING. DECIDED TO GO SLIGHTLY BELOW GUIDANCE FOR LOW TEMPS ESPECIALLY IN THE ISOLD VALLEYS...WHERE LOWS WILL LIKELY DROP BELOW FREEZING. HIGH PRESSURE SLIDES TO OUR EAST AND WARM AIR ADVECTION WITH RETURN FLOW WILL SHOOT OUR TEMPS BACK UP INTO THE 70S...FOR ANOTHER GREAT SPRING DAY. COLD FRONT WILL APPROACH LATE WEDNESDAY NIGHT WITH A WARM FRONT PUSHING THROUGH EARLY THURSDAY MORNING. COULD SEE SOME SHOWERS WITH THE WARM FRONT DURING THE MORNING HOURS...BUT THE HEAVIER PRECIP AND CONVECTION WILL HOLD OFF UNTIL LATER THURSDAY WITH THE PASSING OF THE COLD FRONT...AS EXPLAINED IN THE LONG TERM DISCUSSION BELOW. && .LONG TERM /THURSDAY THROUGH SUNDAY/... THE AREA WILL REMAIN IN THE WARM SECTOR OF A SFC LOW PRESSURE WITH POSSIBLE CONVECTION AHEAD OF A COLD FRONT THROUGH LATE THURSDAY. THEREFORE...KEPT LIKELY POPS FOR THURSDAY. MODELS SHOW LOW SFC CAPE AND HIGH DEEP LAYERED SHEAR ENVIRONMENT WITH PRECIPITABLE WATER UP TO 1.25 INCHES. THESE PARAMETER COULD ALLOW THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON HOURS. THEREFORE...KEPT THUNDER UNDER LIKELY POPS FOR THURSDAY. BY 12Z FRIDAY...THE FRONT WILL BE JUST EAST OF THE APPALACHIANS...BUT A SECONDARY FRONT WILL REINFORCE THE COLD AIR. THE AREA REMAINS UNDER NORTHWEST FLOW THROUGH THE WEEKEND. ANOTHER BUT FASTER SYSTEM CROSS THE GREAT LAKES SATURDAY. USED THE WPC GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... ACTIVE COLD FRONT PUSHING THROUGH THE WV MOUNTAINS EARLY THIS MORNING. EKN WILL BE THE LAST OF THE SIX AREA TAF SITES THE FRONT CROSSES EARLY THIS MORNING...IT SHOULD JUST ABOUT BE THROUGH THERE AS OF 12Z. GUSTY W WINDS WILL BE DIMINISHING FROM W TO E...AS AS THE RAIN SHOWERS MOVE OUT BUT MVFR CIGS SETTLE IN. WHILE THERE MAY BE A FEW VFR HOLES FOR A SHORT TIME THIS MORNING...THESE MVFR CIGS ARE LIKELY TO PERSIST THROUGHOUT THE TAF PERIOD...12Z TUE. GUSTY W TO NW SFC WINDS TODAY WILL GRADUALLY DIMINISH TONIGHT. MODERATE TO STRONG W FLOW ALOFT EARLY THIS MORNING...WILL GRADUALLY BECOME NW TODAY...AND THEN GRADUALLY DIMINISH TONIGHT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING AND EXTENT OF IFR CIGS IN MOUNTAINS MAY VARY...AS MAY TIMING OF MVFR CIGS OTHERWISE. CIGS COULD BREAK UP OVERNIGHT TONIGHT. GUSTY WINDS WILL VARY TODAY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21 EDT 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 CRW CONSISTENCY M M M M M M M M M M H H HTS CONSISTENCY M M M M M M M M M M H H BKW CONSISTENCY M M M M M M M M M M M M EKN CONSISTENCY M M M M M M M M M M M M PKB CONSISTENCY M M M M M M M M M M M M CKB CONSISTENCY M M M M M M M M M M M M AFTER 12Z TUESDAY... IFR POSSIBLE IN STRATUS TUE MORNING...MAINLY IN THE MOUNTAINS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...TRM/MPK NEAR TERM...TRM SHORT TERM...MPK LONG TERM...ARJ AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
441 AM EDT MON MAR 28 2016 .SYNOPSIS... COLD FRONT EXITS EARLY THIS MORNING. COOLER WITH LOW LEVEL MOISTURE LINGERING INTO TONIGHT. HIGH PRESSURE TUESDAY. WARMER WEDNESDAY. LOW PRESSURE/FRONT THURSDAY. COOLER AIR OVER WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... RADAR IS OTS AND TECHS WERE BEING CONTACTED. COLD FRONT WAS BLOWING THROUGH THE AREA EARLY THIS MORNING WITH GUSTY SHOWERS IMMEDIATELY AHEAD OF IT AND GUSTY NW WINDS IMMEDIATELY BEHIND IT. VIGOROUS UPPER LEVEL S/W TROUGH PUSHES THROUGH THE AREA THIS MORNING...WITH WINDS DIMINISHING JUST A BIT BUT REMAINING GUSTY THROUGH THE AFTERNOON AND EVEN INTO THIS EVENING. RAIN SHOWERS WILL MOVE OUT OF THE AREA FIRST THING THIS MORNING BUT UPSLOPE FLOW WILL KEEP SHOWERS GOING IN THE MOUNTAINS. THESE SHOWERS WILL END AS SNOW SHOWERS ACROSS THE HIGHER TERRAIN TOWARD DAWN TUE. IT APPEARS STRATOCU BEHIND THE COLD FRONT WILL BE QUITE TENACIOUS TODAY AND EVEN TONIGHT...WITH ABOUT A 100MB THICK MOIST LAYER TRAPPED BELOW THE FRONTAL INVERSION. EVEN NOTORIOUSLY LOW MAV IS ABOVE FREEZING ALL BUT THE HIGHER TERRAIN TONIGHT...SO WILL NIX HWO MENTION OF FREEZE WHERE GROWING SEASON HAS BEEN STARTED...IN KY...FOR TONIGHT AND EARLY TUE MORNING. PREFERRED THE LOWER RUC FOR TEMPERATURES TODAY UNDER THE OVERCAST. EVEN WITH BLENDING IN THE LOWEST OF THE GUIDANCE OPTIONS...THE BIAS CORRECTED MAV...LOWS TONIGHT ARE A BIT HIGHER THAN PREVIOUS PACKAGE FOR THE MOST PART GIVEN THE CLOUD COVER. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... GUIDANCE IS IN FAIRLY GOOD AGREEMENT WITH OVERALL PATTERN FOR THE SHORT TERM PERIOD WITH ONLY SOME MINOR TIMING ISSUES FOR PRECIP ARRIVAL THURSDAY MORNING. HIGH PRESSURE MOVES OVERHEAD TUESDAY AND BRINGS DRY...BUT COOL CONDITIONS. EVEN THOUGH WARM AIR ADVECTION WILL BEGIN ALOFT ON TUESDAY NIGHT...CLEAR SKIES AND LIGHT WINDS SHOULD MAKE FOR EFFICIENT RADIATIONAL COOLING. DECIDED TO GO SLIGHTLY BELOW GUIDANCE FOR LOW TEMPS ESPECIALLY IN THE ISOLD VALLEYS...WHERE LOWS WILL LIKELY DROP BELOW FREEZING. HIGH PRESSURE SLIDES TO OUR EAST AND WARM AIR ADVECTION WITH RETURN FLOW WILL SHOOT OUR TEMPS BACK UP INTO THE 70S...FOR ANOTHER GREAT SPRING DAY. COLD FRONT WILL APPROACH LATE WEDNESDAY NIGHT WITH A WARM FRONT PUSHING THROUGH EARLY THURSDAY MORNING. COULD SEE SOME SHOWERS WITH THE WARM FRONT DURING THE MORNING HOURS...BUT THE HEAVIER PRECIP AND CONVECTION WILL HOLD OFF UNTIL LATER THURSDAY WITH THE PASSING OF THE COLD FRONT...AS EXPLAINED IN THE LONG TERM DISCUSSION BELOW. && .LONG TERM /THURSDAY THROUGH SUNDAY/... THE AREA WILL REMAIN IN THE WARM SECTOR OF A SFC LOW PRESSURE WITH POSSIBLE CONVECTION AHEAD OF A COLD FRONT THROUGH LATE THURSDAY. THEREFORE...KEPT LIKELY POPS FOR THURSDAY. MODELS SHOW LOW SFC CAPE AND HIGH DEEP LAYERED SHEAR ENVIRONMENT WITH PRECIPITABLE WATER UP TO 1.25 INCHES. THESE PARAMETER COULD ALLOW THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON HOURS. THEREFORE...KEPT THUNDER UNDER LIKELY POPS FOR THURSDAY. BY 12Z FRIDAY...THE FRONT WILL BE JUST EAST OF THE APPALACHIANS...BUT A SECONDARY FRONT WILL REINFORCE THE COLD AIR. THE AREA REMAINS UNDER NORTHWEST FLOW THROUGH THE WEEKEND. ANOTHER BUT FASTER SYSTEM CROSS THE GREAT LAKES SATURDAY. USED THE WPC GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... ACTIVE COLD FRONT BRINGING UNFAVORABLE TAKE OFF AND LANDING CONDITIONS THROUGH EARLY MON MORNING. THE FRONT WAS JUST APPROACHING WV FROM THE W AS OF 06Z. GUSTY SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONT WILL BRING MVFR TO BRIEF IFR CANDIDNESS...ALONG WITH WIND GUSTS TO 35 KTS OR SO. FOLLOWING THE FRONT...WIND SHIFTS TO THE NW WITH GUSTS TO AROUND 35 KTS AGAIN POSSIBLE. THESE STRONG WINDS SHOULD DIMINISH WITHIN AN HOUR OR TWO OF THE FRONTAL PASSAGE...AND VSBYS WILL IMPROVE...BUT CIGS WILL REMAIN MVFR THROUGH THE BALANCE OF THE TAF PERIOD...06Z TUE...AND GO IFR AT TIMES ACROSS RIDGES INCLUDING BKW. W TO NW SFC WINDS WILL REMAIN GUSTY THROUGH THE DAY MON BEFORE GRADUALLY DIMINISHING MON NT. MODERATE SW FLOW WILL BECOME MODERATE TO STRONG BEHIND THE COLD FRONT EARLY MON MORNING...AND THEN GRADUALLY DIMINISH TO LIGHT TO MODERATE NW MON NT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY... FORECAST CONFIDENCE: LOW TO MEDIUM. ALTERNATE SCENARIOS: TIMING OF PRECIPITATION AND ASSOCIATED MVFR / IFR CONDITIONS WITH ACTIVE COLD FRONT MAY VARY FROM FORECAST. MORE WIDESPREAD IFR MAY OCCUR ON MON BEHIND THE FRONT THAN CURRENTLY FORECAST. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE MON 03/28/16 UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19 EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15 CRW CONSISTENCY M M M M M M M M M M M M HTS CONSISTENCY M M M M M M M M M M M M BKW CONSISTENCY M M M M M M M M M M M M EKN CONSISTENCY M M M M M M M M M M M M PKB CONSISTENCY M M M M M M M M M M M M CKB CONSISTENCY M M M M M M M M M M M M AFTER 06Z TUESDAY... IFR POSSIBLE IN STRATUS TUESDAY MORNING...MAINLY IN THE MOUNTAINS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...TRM/MPK NEAR TERM...TRM SHORT TERM...MPK LONG TERM...ARJ AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
209 AM EDT MON MAR 28 2016 .SYNOPSIS... COLD FRONT EARLY MONDAY MORNING. LOW LEVEL MOISTURE LINGERS IN COOLER TEMPERATURES INTO MONDAY NIGHT. HIGH PRESSURE TUESDAY. WARMER WEDNESDAY. LOW PRESSURE/FRONT THURSDAY. COOLER AIR AGAIN OVER WEEKEND. && .NEAR TERM /THROUGH TODAY/... 200 AM UPDATE... FCST ON TRACK WITH ACTIVE FRONT ON WRN FLANK OF FCST AREA. STORM THAT FORMED OUT AHEAD OF PRE-COLD-FRONTAL LINE OF STORMS HAD ITS ON FRESH FEED OF WARM MOIST AIR AND WAS LOCATED ALONG WARM FRONT. MAIN LINE IS NOT SEVERE BUT CONTAINS 40 MPH GUSTS IN THE SHOWERS/EMBEDDED STORMS AND FROM THE W TO NW BEHIND THE COLD FRONT. ADDED GUSTY WORDING TO THE THUNDERSTORMS OVERNIGHT AND CRANKED UP THE GUSTS BEHIND THE FRONT INTO MON MORNING. 930 PM UPDATE... POSSIBILITY OF SOME STRONG STORMS THIS EVENING...PARTICULARLY ACROSS WESTERN ZONES...AS LINE OF STORMS IN NW OHIO...INDIANA AND WESTERN KY CONTINUES TO RACE EASTWARDS...AS A COLD FRONT ASSOCIATED WITH A DEEPENING LOW PRESSURE SYSTEM...CURRENTLY MOVING NORTHEAST TOWARDS THE GREAT LAKES...AND A NEGATIVELY TILTED UPPER SHORTWAVE TROUGH PUSHES EAST INTO THE MID MISSISSIPPI VALLEY REGION. MAIN THREAT WILL BE STRONG WINDS...WITH STRENGTHENING SHEAR OF 60+KTS OUT AHEAD OF FRONT. THERE IS SOME EVIDENCE OF WEAKENING OF STORMS ACROSS THE NORTHERN HALF OF THE LINE...AS SOUTHERN STORMS STRENGTHEN...AND IT IS STILL YET TO BE SEEN HOW IT WILL ALL PLAY OUT...BUT THERE IS A RISK FOR STRONG WINDS TONIGHT WITH ANY CONVECTION...MAINLY ACROSS OUR WEST. PREVIOUS DISCUSSION FOLLOWS... WITH MORNING UPDATE HAD PUT IN SOME ISOLATED SHOWERS AS A PSEUDO WARM FRONT LIFTS ACROSS CWA...HOWEVER RADAR ECHOS HAVE LARGELY DRIED UP SO TOOK THAT MENTION BACK OUT. HRRR STILL TRIES TO KICK OFF A SHOWER OR TWO...BUT WITH THICK CIRRUS NOW IN PLACE...DO NOT SEE US BEING ABLE TO POP ANYTHING MORE THAN SOME CU. HAVE CLOUDS CONTINUING TO INCREASE AND LOWER INTO THIS EVENING...AS A SOUTHERN STREAM SYSTEM STARTS MAKING ITS WAY UP THE ATLANTIC COAST. STILL THINKING WE COULD GET SOME ISOLATED TO SCATTERED SHOWERS ACROSS THE EASTERN SLOPES LATER THIS AFTERNOON OR EVENING...SO LEFT SOME LOW POPS THERE. OTHERWISE...ATTENTION TURNS TO NORTHERN STREAM LOW PRESSURE SYSTEM WHICH WILL LIFT THROUGH THE GREAT LAKES TONIGHT. THIS WILL DRIVE A COLD FRONT THROUGH THE CWA LATE TONIGHT/EARLY MONDAY. HAVE 80-100 POPS ALONG AND AHEAD OF THE FRONT AS IT CROSSES. MUCH LIKE THE LAST DECENT COLD FRONT WE HAD PASS...PWATS DRY UP SOME AS THE SYSTEM MOVES EAST...SO HAVE HIGHEST QPF ACROSS SE OHIO -- GENERALLY 0.5 INCH...TAPERING DOWN TO ONLY AROUND 0.25 INCH ACROSS THE MOUNTAINS. ANY INSTABILITY OF NOTE REMAINS LARGELY TO OUR WEST UNTIL SOME 200-400J/KG CAPE SLIDES THROUGH RIGHT AHEAD OF THE FRONT...AND BY THAT TIME WE ARE GETTING INTO THE DIURNAL MINIMUM FOR CONVECTION. HAVE ISOLATED TO SCATTERED THUNDER IN THE OHIO RIVER VALLEY EASTWARD TO AROUND THE I-79 CORRIDOR BEFORE FADING OUT. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY/... 850 MB THERMAL TROF PASSES AROUND 12Z TUESDAY...12Z NAM AND ECMWF ABOUT 1 TO 2C COLDER THAN THE 12Z GFS. LOWERED MIN TEMP AOA 4000 THSD A DEGREE OR TWO...TRENDING COLDER THAN GFS. OVERNIGHT MONDAY NIGHT...THINNING MOISTURE UNDER THE SUBSIDENCE INVERSION AOB 5 THSD FT...SO CLOUD COVER TOUGH...WITH HOLES OPENING UP. STILL HAVE THE LOWERING POPS OVER OUR CENTRAL MOUNTAINS FOR SPOTTY LIGHT RAIN SHOWER...MAYBE A SPOTTY LIGHT SNOW SHOWER UP HIGH. STILL THOUGHT ENOUGH CLEARING IN NE KENTUCKY MONDAY NIGHT FOR POSSIBLE MIN TEMP NEAR FREEZING FOR DAWN TUESDAY. WILL INSERT IN OUR HAZARDOUS WEATHER OUTLOOK FOR KY SINCE THAT IS WHERE OUR SPRING FREEZE PROGRAM AS ALREADY STARTED. WITH MARGINAL TEMPERATURES AND CLOUD CONCERNS FOR AT LEAST PART OF THE NIGHT...DID NOT POST A FREEZE WATCH. WITH HIGH PRESSURE OVER OUR VICINITY AT START OF TUESDAY NIGHT...THOUGHT NOCTURNAL INVERSION MAY FORM IN VALLEYS BEFORE THE THE LOW LEVEL FLOW FROM THE SOUTHEAST INCREASES 06Z TO 12Z WEDNESDAY. SO LOWERED MIN TEMPS IN THE SHELTERED VALLEYS. ANOTHER NICE MARCH DAY FOR WEDNESDAY...FOR THIS WARM MARCH OF 2016. A LARGE DIURNAL TEMP SPREAD WITH 850 TEMPS WARMING TO 14C IN SRN LOWLANDS BY LATE AFTERNOON. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... MODELS SUGGEST THAT A SFC HIGH PRESSURE MOVE OFF THE ATLANTIC COAST ALLOWING A WARM FRONT TO LIFT NORTH EARLY THURSDAY. THIS WARM FRONT COULD BRING SOME RAIN EARLY THURSDAY...BUT THE AREA WILL REMAIN IN THE WARM SECTOR OF A SFC LOW PRESSURE WITH POSSIBLE CONVECTION AHEAD OF THE COLD FRONT THROUGH LATE THURSDAY. THEREFORE...KEPT LIKELY POPS FOR THURSDAY. MODELS SHOW LOW SFC CAPE AND HIGH DEEP LAYERED SHEAR ENVIRONMENT WITH PRECIPITABLE WATER UP TO 1.25 INCHES. THESE PARAMETER COULD ALLOW THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON HOURS. THEREFORE...KEPT THUNDER UNDER LIKELY POPS FOR THURSDAY. BY 12Z FRIDAY...THE FRONT WILL BE JUST EAST OF THE APPALACHIANS...BUT A SECONDARY FRONT WILL REINFORCE THE COLD AIR. THE AREA REMAINS UNDER NORTHWEST FLOW THROUGH THE WEEKEND. ANOTHER BUT FASTER SYSTEM CROSS THE GREAT LAKES SATURDAY. USED THE WPC GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... ACTIVE COLD FRONT BRINGING UNFAVORABLE TAKE OFF AND LANDING CONDITIONS THROUGH EARLY MON MORNING. THE FRONT WAS JUST APPROACHING WV FROM THE W AS OF 06Z. GUSTY SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONT WILL BRING MVFR TO BRIEF IFR CANDIDNESS...ALONG WITH WIND GUSTS TO 35 KTS OR SO. FOLLOWING THE FRONT...WIND SHIFTS TO THE NW WITH GUSTS TO AROUND 35 KTS AGAIN POSSIBLE. THESE STRONG WINDS SHOULD DIMINISH WITHIN AN HOUR OR TWO OF THE FRONTAL PASSAGE...AND VSBYS WILL IMPROVE...BUT CIGS WILL REMAIN MVFR THROUGH THE BALANCE OF THE TAF PERIOD...06Z TUE...AND GO IFR AT TIMES ACROSS RIDGES INCLUDING BKW. W TO NW SFC WINDS WILL REMAIN GUSTY THROUGH THE DAY MON BEFORE GRADUALLY DIMINISHING MON NT. MODERATE SW FLOW WILL BECOME MODERATE TO STRONG BEHIND THE COLD FRONT EARLY MON MORNING...AND THEN GRADUALLY DIMINISH TO LIGHT TO MODERATE NW MON NT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY... FORECAST CONFIDENCE: LOW TO MEDIUM. ALTERNATE SCENARIOS: TIMING OF PRECIPITATION AND ASSOCIATED MVFR / IFR CONDITIONS WITH ACTIVE COLD FRONT MAY VARY FROM FORECAST. MORE WIDESPREAD IFR MAY OCCUR ON MON BEHIND THE FRONT THAN CURRENTLY FORECAST. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE MON 03/28/16 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 CRW CONSISTENCY H M M M M M M M M M M M HTS CONSISTENCY M M M M M M M M M M M M BKW CONSISTENCY M M M M M M M M M M M M EKN CONSISTENCY H H M M M M M M M M M M PKB CONSISTENCY M M M M M M M M M M M M CKB CONSISTENCY H H M M M M M M M M M M AFTER 06Z TUESDAY... IFR POSSIBLE IN STRATUS TUESDAY MORNING...MAINLY IN THE MOUNTAINS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...TRM/MZ/MPK NEAR TERM...TRM/MZ/SL SHORT TERM...KTB LONG TERM...ARJ AVIATION...TRM
AREA FORECAST DISCUSSION
NWS NORMAN OK
651 PM CDT TUE MAR 29 2016 .AVIATION... VFR CEILINGS BETWEEN 4-5K FEET WILL LOWER THIS EVENING AND OVERNIGHT TO MVFR (PERHAPS IFR). RUC SOUNDINGS SUGGEST THAT CAPPING INVERSION MAY BE LIFTED ENOUGH FOR WIDELY SCATTERED EARLY MORNING CONVECTION...MAINLY IN AND AROUND LAW/OUN/OKC. ADDITIONAL STORMS MAY FORM IN AND NEAR PNC/OKC/OUN AS A DRYLINE APPROACHES FROM THE WEST. OTHERWISE...GUSTY SOUTH WINDS WILL CONTINUE THIS EVENING AND OVERNIGHT. THE WIND WILL SHIFT TO THE SOUTHWEST AND WEST IN WESTERN OKLAHOMA WEDNESDAY MORNING/AFTERNOON. && .PREV DISCUSSION... /ISSUED 340 PM CDT TUE MAR 29 2016/ DISCUSSION... LOW-LEVEL MOISTURE WILL CONTINUE TO INCREASE OVERNIGHT...AS A DRYLINE TAKES SHAPE TO OUR WEST. VERY MOIST ISENTROPIC LIFT SUGGESTS DRIZZLE OVER MUCH OF OUR FORECAST AREA OVERNIGHT...WHILE SUBSTANTIAL MU CAPE INDICATES THAT THUNDERSTORMS...IF THEY OCCUR...COULD EASILY BE SEVERE. STORMS ARE MORE LIKELY TO FORM TOMORROW...AS A STRONG UPPER-LEVEL SPEED MAXIMUM APPROACHES FROM THE SOUTHWEST...AND SEVERE POTENTIAL WILL CONTINUE THROUGH THE DAY...MAINLY IN THE FORM OF HAIL...BUT OTHER SEVERE CHARACTERISTICS WILL CERTAINLY BE POSSIBLE. THE EVENING SEVERE-WEATHER SCENARIO IS STILL UNCERTAIN. THE NAM SUGGESTS THAT A FEW SUPERCELL STORMS MAY FORM SOMEWHERE ALONG A LINE FROM NEAR STILLWATER TO OKLAHOMA CITY TO DUNCAN AND HENRIETTA TEXAS LATE IN THE AFTERNOON OR IN THE EARLY EVENING. OTHER MODELS SHOW THE DRYLINE FARTHER EAST...AND WITHOUT THE SUPERPOSITION OF MAXIMUM SHEAR AND INSTABILITY NEAR THE DRYLINE BY THAT TIME. OUR FORECAST CURRENTLY TAKES SOMEWHAT OF A MIDDLE GROUND...WITH LOWER POPS IN THE EVENING...BUT RETAINING THE MENTION OF SEVERE STORMS. WE WILL RETAIN THE FIRE WEATHER WATCH AS IS. DRY/BREEZY WEATHER BEHIND THE DRYLINE PROMISES TO RAISE THE WILDFIRE POTENTIAL INTO THE CRITICAL CATEGORY OVER THAT AREA DURING THE AFTERNOON AND EARLY EVENING. GENERALLY BENIGN WEATHER WILL FOLLOW FOR THE REMAINDER OF THE FORECAST PERIOD. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 58 78 45 67 / 20 40 20 0 HOBART OK 59 79 43 68 / 20 20 10 0 WICHITA FALLS TX 62 82 46 70 / 30 40 10 0 GAGE OK 54 76 37 66 / 20 10 0 0 PONCA CITY OK 58 78 42 66 / 20 40 20 0 DURANT OK 61 73 51 69 / 40 70 30 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR OKZ004>006-009>011-014>016-021-022-033>037. TX...FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR TXZ083>085-087-088. && $$
AREA FORECAST DISCUSSION
NWS NORMAN OK
1225 PM CDT MON MAR 28 2016 .DISCUSSION... THE 18Z AVIATION DISCUSSION FOLLOWS.... && .AVIATION... WINDS WILL INCREASE A BIT IN SPEED THIS AFTERNOON...AND ARE NOT EXPECTED TO DIMINISH MUCH OVERNIGHT...AS THE SURFACE PRESSURE GRADIENT SLOWLY TIGHTENS. LOW-LEVEL MOISTURE WILL INCREASE QUICKLY TOMORROW MORNING...AND SOME STRATUS APPEARS LIKELY. THE STRATUS DECK IS MOST LIKELY IN THE WEST...WHERE IT WILL ALSO BE A LITTLE LOWER. WIND SPEEDS WILL INCREASE FURTHER TOMORROW AS THE SURFACE PRESSURE GRADIENT CONTINUES TO TIGHTEN. CMS && .PREV DISCUSSION... /ISSUED 1051 AM CDT MON MAR 28 2016/ UPDATE... INCREASED AFTERNOON HIGHS SLIGHTLY. ALSO...TWEAKED AFTERNOON DEWPOINTS. DISCUSSION... SUNNY AND WARMER WEATHER WILL OCCUR THIS AFTERNOON. INCREASING SOUTH WINDS AND LOW HUMIDITY WILL ELEVATE FIRE WEATHER CONCERNS THIS AFTERNOON INTO EARLY EVENING. INCREASED HIGHS BASED ON ABUNDANT SUNSHINE TODAY WHICH WILL INCREASE VERTICAL MIXING. LATEST HRRR RUNS SEEM TO HAVE A GREAT HANDLE ON HOURLY TEMPERATURE CURVES. AFTERNOON DEWPOINTS WERE TWEAKED ACROSS THE AREA...MAINLY TO LOWER THEM IN CENTRAL AND NORTH CENTRAL OKLAHOMA...AND TO SLIGHTLY INCREASE THEM NEAR THE RED RIVER. STILL APPEARS FIRE WEATHER CONDITIONS THIS AFTERNOON AND EARLY EVENING WILL STAY JUST BELOW RED FLAG CONDITIONS. THE STRONGEST WINDS OF 20 TO 30 MPH WITH GUSTS 25 TO 40 MPH WILL OCCUR IN FAR WESTERN OKLAHOMA NEAR GAGE...WOODWARD...AND CHEYENNE...AND THE LOWEST AFTERNOON AND EARLY EVENING HUMIDITY VALUES WILL BE NEAR PONCA CITY...ENID...AND STILLWATER...GENERALLY 15 TO 25 PERCENT. PRODUCTS WILL BE UPDATED SHORTLY. MBS PREV DISCUSSION... /ISSUED 629 AM CDT MON MAR 28 2016/ DISCUSSION... 28/12Z TAF DISCUSSION. AVIATION... VFR CONDITIONS EXPECTED TO PREVAIL WITH RETURN TO AND INCREASE IN SOUTH/SOUTHEAST WIND TODAY. WINDS WILL BECOME STRONG ACROSS FAR WESTERN OKLAHOMA TERMINALS TOWARD AND AFTER 16Z. VFR STRATUS EXPECTED TO SPREAD INTO AT LEAST WESTERN NORTH TEXAS AND SOUTHWEST OKLAHOMA TERMINALS AFTER 06Z. PREV DISCUSSION... /ISSUED 405 AM CDT MON MAR 28 2016/ DISCUSSION... FREEZE WARNING AND FROST ADVISORY WILL BE LEFT INTACT EARLY THIS MORNING. WINDS WILL BECOME GUSTY ACROSS WESTERN OKLAHOMA AND WESTERN NORTH TEXAS THIS AFTERNOON. AHEAD OF ANY SUBSTANTIAL MOISTURE RETURN... THIS WILL ELEVATE THE FIRE DANGER. WARMER AND STRONGER WIND EXPECTED ON TUESDAY BUT RH VALUES SHOULD BE CONSIDERABLY HIGHER AS LOW LEVEL MOISTURE INCREASES. CRITICAL FIRE DANGER STILL POSSIBLE WEDNESDAY AFTERNOON OVER FAR WEST/NORTHWEST OKLAHOMA BEHIND THE DRYLINE. MUCH OF CENTRAL AND SOUTHERN OKLAHOMA EASILY IN THE FUEL TRANSITION PHASE AND THERE IS EXPECTED TO BE SCATTERED TO NUMEROUS SHOWERS AND STORMS ONGOING WEDNESDAY MORNING WHICH WOULD GIVE BRIEF WINDOW FOR FINE FUEL DRYING. STORMS WILL BE POSSIBLE LATE TONIGHT AND EARLY TUESDAY MORNING MAINLY NORTHERN OKLAHOMA UP INTO KANSAS ON LEADING EDGE OF LOWER LEVEL MOISTURE PLUME. MORE WIDESPREAD SHOWERS AND STORMS EXPECTED TUESDAY NIGHT AND WEDNESDAY MORNING AS MOISTURE DEEPENS. CHANCES FOR ORGANIZED SEVERE WEATHER ACTIVITY TONIGHT AND LATE TUESDAY/EARLY WEDNESDAY ARE LOW. AS FAR AS SEVERE CONVECTION...IT STILL APPEARS THAT ANY SUBSTANTIAL SEVERE WEATHER THREAT WILL BE OVER THE EASTERN HALF OF OKLAHOMA LATE WEDNESDAY AFTERNOON AND EVENING. IF THE MENTIONED SHOWERS AND STORMS ORGANIZE WEDNESDAY MORNING AS SUGGESTED BY MODELS...OVERALL ENVIRONMENT WILL BE MORE IN QUESTION FOR OUR CWA. DRY WEATHER WITH SEASONABLE TEMPS EXPECTED THURSDAY INTO NEXT WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 70 46 70 56 / 0 10 10 30 HOBART OK 71 49 72 57 / 0 10 10 20 WICHITA FALLS TX 72 49 75 59 / 0 10 10 30 GAGE OK 71 48 73 51 / 0 10 0 10 PONCA CITY OK 70 42 70 53 / 0 10 10 30 DURANT OK 69 46 72 61 / 0 0 10 40 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 17/23/23
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1051 AM CDT MON MAR 28 2016 .UPDATE... INCREASED AFTERNOON HIGHS SLIGHTLY. ALSO...TWEAKED AFTERNOON DEWPOINTS. && .DISCUSSION... SUNNY AND WARMER WEATHER WILL OCCUR THIS AFTERNOON. INCREASING SOUTH WINDS AND LOW HUMIDITY WILL ELEVATE FIRE WEATHER CONCERNS THIS AFTERNOON INTO EARLY EVENING. INCREASED HIGHS BASED ON ABUNDANT SUNSHINE TODAY WHICH WILL INCREASE VERTICAL MIXING. LATEST HRRR RUNS SEEM TO HAVE A GREAT HANDLE ON HOURLY TEMPERATURE CURVES. AFTERNOON DEWPOINTS WERE TWEAKED ACROSS THE AREA...MAINLY TO LOWER THEM IN CENTRAL AND NORTH CENTRAL OKLAHOMA...AND TO SLIGHTLY INCREASE THEM NEAR THE RED RIVER. STILL APPEARS FIRE WEATHER CONDITIONS THIS AFTERNOON AND EARLY EVENING WILL STAY JUST BELOW RED FLAG CONDITIONS. THE STRONGEST WINDS OF 20 TO 30 MPH WITH GUSTS 25 TO 40 MPH WILL OCCUR IN FAR WESTERN OKLAHOMA NEAR GAGE...WOODWARD...AND CHEYENNE...AND THE LOWEST AFTERNOON AND EARLY EVENING HUMIDITY VALUES WILL BE NEAR PONCA CITY...ENID...AND STILLWATER...GENERALLY 15 TO 25 PERCENT. PRODUCTS WILL BE UPDATED SHORTLY. MBS && .PREV DISCUSSION... /ISSUED 629 AM CDT MON MAR 28 2016/ DISCUSSION... 28/12Z TAF DISCUSSION. AVIATION... VFR CONDITIONS EXPECTED TO PREVAIL WITH RETURN TO AND INCREASE IN SOUTH/SOUTHEAST WIND TODAY. WINDS WILL BECOME STRONG ACROSS FAR WESTERN OKLAHOMA TERMINALS TOWARD AND AFTER 16Z. VFR STRATUS EXPECTED TO SPREAD INTO AT LEAST WESTERN NORTH TEXAS AND SOUTHWEST OKLAHOMA TERMINALS AFTER 06Z. PREV DISCUSSION... /ISSUED 405 AM CDT MON MAR 28 2016/ DISCUSSION... FREEZE WARNING AND FROST ADVISORY WILL BE LEFT INTACT EARLY THIS MORNING. WINDS WILL BECOME GUSTY ACROSS WESTERN OKLAHOMA AND WESTERN NORTH TEXAS THIS AFTERNOON. AHEAD OF ANY SUBSTANTIAL MOISTURE RETURN... THIS WILL ELEVATE THE FIRE DANGER. WARMER AND STRONGER WIND EXPECTED ON TUESDAY BUT RH VALUES SHOULD BE CONSIDERABLY HIGHER AS LOW LEVEL MOISTURE INCREASES. CRITICAL FIRE DANGER STILL POSSIBLE WEDNESDAY AFTERNOON OVER FAR WEST/NORTHWEST OKLAHOMA BEHIND THE DRYLINE. MUCH OF CENTRAL AND SOUTHERN OKLAHOMA EASILY IN THE FUEL TRANSITION PHASE AND THERE IS EXPECTED TO BE SCATTERED TO NUMEROUS SHOWERS AND STORMS ONGOING WEDNESDAY MORNING WHICH WOULD GIVE BRIEF WINDOW FOR FINE FUEL DRYING. STORMS WILL BE POSSIBLE LATE TONIGHT AND EARLY TUESDAY MORNING MAINLY NORTHERN OKLAHOMA UP INTO KANSAS ON LEADING EDGE OF LOWER LEVEL MOISTURE PLUME. MORE WIDESPREAD SHOWERS AND STORMS EXPECTED TUESDAY NIGHT AND WEDNESDAY MORNING AS MOISTURE DEEPENS. CHANCES FOR ORGANIZED SEVERE WEATHER ACTIVITY TONIGHT AND LATE TUESDAY/EARLY WEDNESDAY ARE LOW. AS FAR AS SEVERE CONVECTION...IT STILL APPEARS THAT ANY SUBSTANTIAL SEVERE WEATHER THREAT WILL BE OVER THE EASTERN HALF OF OKLAHOMA LATE WEDNESDAY AFTERNOON AND EVENING. IF THE MENTIONED SHOWERS AND STORMS ORGANIZE WEDNESDAY MORNING AS SUGGESTED BY MODELS...OVERALL ENVIRONMENT WILL BE MORE IN QUESTION FOR OUR CWA. DRY WEATHER WITH SEASONABLE TEMPS EXPECTED THURSDAY INTO NEXT WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 70 46 70 56 / 0 10 10 30 HOBART OK 71 49 72 57 / 0 10 10 20 WICHITA FALLS TX 72 49 75 59 / 0 10 10 30 GAGE OK 71 48 73 51 / 0 10 0 10 PONCA CITY OK 70 42 70 53 / 0 10 10 30 DURANT OK 69 46 72 61 / 0 0 10 40 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 17/23
AREA FORECAST DISCUSSION
NWS PORTLAND OR
924 PM PDT SUN MAR 27 2016 .SYNOPSIS...A COOL LOW PRESSURE SYSTEM CONTINUES TO BRING SHOWERS TO SOUTHWEST WASHINGTON AND WESTERN OREGON...WITH TEMPERATURES COOL ENOUGH FOR SNOW IN THE CASCADES. UNSETTLED WEATHER WILL GRADUALLY COME TO AN END MONDAY AS THE MAIN UPPER LOW DRIFTS S-SE INTO THE GREAT BASIN. HIGH PRESSURE AND OFFSHORE FLOW WILL SUPPORT MUCH DRIER AND MILDER WEATHER TUESDAY AND WEDNESDAY...WITH A BLOCKING UPPER LEVEL RIDGE KEEPING TEMPERATURES ABOVE NORMAL WITH LITTLE TO NO CHANCE FOR RAIN THROUGH AT LEAST FRIDAY. THE RIDGE MAY BREAK DOWN ENOUGH TO ALLOW THE NEXT CHANCE FOR RAIN NEXT WEEKEND...BUT THAT REMAINS HIGHLY UNCERTAIN. && .EVENING UPDATE...WIDESPREAD SHOWERS CONTINUE ALONG THE COAST AND HIGHER TERRAIN THIS EVENING...WITH A LITTLE LESS COVERAGE TO THE SHOWERS FOR THE INLAND VALLEYS. 02Z HRRR RUN INITIALIZES 500 MB TEMPS AT -33 TO -34 DEG C IN THE HEART OF THE COLD POOL ALOFT... PRESENTLY JUST OFF THE NORTHERN OREGON COAST. THIS COLD POOL WILL CONTINUE TO SINK SOUTHEAST ALONG THE COAST...MOVING ONSHORE ALONG THE CENTRAL AND SOUTHERN OREGON COAST LATER TONIGHT. ISOLATED THUNDER AND SMALL HAIL ARE STILL POSSIBLE TONIGHT IN HEAVIER SHOWERS...WITH THE BEST CHANCE BEING ALONG THE COAST AND ADJACENT COASTAL WATERS. SHOWER ACTIVITY SHOULD GENERALLY DECREASE FROM NORTH TO SOUTH MONDAY...WITH SHOWERS TENDING TO FAVOR THE HIGHER TERRAIN. 00Z FREEZING LEVEL AT SALEM WAS ABOUT 3500 FEET...WHICH SUGGESTS SNOW MAY FALL AS LOW AS 2000 TO 2500 FEET IN SHOWERS. HEAVIER SHOWERS WILL PRODUCE OCCASIONAL DUSTINGS OF UP TO 1 INCH AT A TIME ABOVE 3000 FEET...BUT OVERALL ACCUMULATIONS WILL PROBABLY BE LIGHT. HOWEVER...SINCE AROUND 6 PM MOUNT HOOD HAS BEEN DIFFERENT. SNOTELS NEAR MOUNT HOOD MEADOWS HAVE REPORTED AN IMPRESSIVE 4-6 INCHES OF SNOW IN JUST THE PAST 2-4 HOURS. WITH FLOW FAIRLY UNIDIRECTIONAL FROM THE W-NW...A TERRAIN-DRIVEN CONVERGENCE ZONE SET UP BETWEEN ESTACADA AND MOUNT HOOD. SIMILAR TO THE INFAMOUS PUGET SOUND CONVERGENCE ZONE NEAR SEATTLE...THIS PRODUCED A PERSISTENT BAND OF MODERATE TO HEAVY SNOW ON MOUNT HOOD...ESPECIALLY ON THE SOUTH SLOPES. ANOTHER... SIMILAR BAND OF SHOWERS IS SETTING UP CLOSER TO THE COLUMBIA RIVER...AND WILL PROBABLY DRIFT TOWARD MOUNT HOOD AS WELL FOR A FEW MORE INCHES OF SNOW. WE CONSIDERED A WINTER WX ADVISORY...BUT GIVEN THE HIGHLY LOCALIZED NATURE OF THIS BAND WE DECIDED TO HANDLE IT WITH A SPECIAL WEATHER STATEMENT. EITHER WAY...THOSE PLANNING TRAVEL ACROSS MOUNT HOOD ALONG HWY 26 SHOULD CARRY CHAINS AND BE PREPARED FOR SNOW COVERED ROADS AND POOR VISIBILITY. OTHERWISE THE FORECAST APPEARS TO BE IN GOOD SHAPE AND THE PREVIOUS SHORT AND LONG TERM DISCUSSIONS REMAIN VALID. WEAGLE .SHORT TERM...AN UPPER LEVEL TROUGH OVER THE PACIFIC NW WILL CONTINUE SHOWERS THROUGH MONDAY. SOME SHOWERS WILL CONTAIN SMALL HAIL THIS AFTERNOON AND EVENING WITH A SLIGHT THREAT FOR THUNDERSTORMS. WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL SHORTWAVE DIGGING THE PARENT TROUGH SOUTHWARD. THE TROUGH WILL CONTINUE TO MOVE SOUTH TONIGHT AND MONDAY...ALLOWING AN UPPER RIDGE OVER THE NE PACIFIC TO NEAR THE WASHINGTON COAST. SHOWERS WILL DECREASE FROM NORTH TO SOUTH MONDAY AS THE UPPER RIDGE MOVES OVER THE PACIFIC NW. AS THE RIDGE BUILDS TO THE NORTH...THE UPPER TROUGH DIGS FURTHER SOUTH AND FORMS A LARGE UPPER LOW OVER THE SW STATES (NEVADA AND ARIZONA) MONDAY NIGHT AND TUESDAY. SHOWERS WILL END OVER THE PORTLAND FORECAST AREA AT THIS TIME WITH DRY NORTHERLY WINDS MOVING OVER THE AREA. SOME CLOUDS ROTATING AROUND THE UPPER LOW WILL PREVENT SKIES FROM CLEARING COMPLETELY...BUT THERE MAY BE ENOUGH CLEARING FOR TEMPERATURES TO DROP INTO THE MID AND UPPER 30S EARLY TUESDAY MORNING. WITH DRY AIR MASS AND PARTIAL CLEARING COULD SEE PATCHY FROST IN RURAL AREAS IF TEMPERATURES THERE DROP INTO THE LOWER 30S. AFTER A CHILLY START AND SOME PATCHY FOG TUESDAY MORNING...WILL HAVE A PLEASANT AND MILD SPRING DAY WITH PLENTY OF SUNSHINE...AND AFTERNOON TEMPERATURES WARMING INTO THE 60S INLAND AND MID TO UPPER 50S FOR THE COASTAL AREAS. ANOTHER COOL AND CLEAR NIGHT EXPECTED TUESDAY...WITH DRY AIR WELL ESTABLISHED OVER THE AREA. THE LOW LEVEL WINDS WILL TURN OFFSHORE TUESDAY NIGHT AND WEDNESDAY AS A SURFACE THERMAL TROUGH BUILDS OFFSHORE. THIS WILL MAINTAIN CLEAR SKIES AND ALLOW TEMPERATURES TO WARM INTO THE MID AND UPPER 60S WEDNESDAY AFTERNOON. TJ RADAR UPDATE...NWS DOPPLER KRTX RADAR CONTINUES TO EXPERIENCE OCCASIONAL BUT BRIEF OUTAGES. AT THIS POINT...NO ESTIMATE AS TO WHEN THIS ISSUE WILL BE RESOLVED. .LONG TERM...WEDNESDAY NIGHT THROUGH SATURDAY. GOOD AGREEMENT WITH RESPECT TO THE OVERALL PATTERN THROUGH MUCH OF THE EXTENDED PERIOD. FOR WEDNESDAY NIGHT AND THURSDAY THE UPPER RIDGE AXIS REMAINS FIRMLY IN PLACE...CENTERED AROUND 135W...WITH AN OMEGA BLOCK ANCHORED BY A PAIR OF UPPER LEVEL LOWS...ONE OVER THE CENTRAL PACIFIC AND THE OTHER OVER THE GREAT BASIN OR SOUTHWESTERN U.S. THIS WILL PERSIST THROUGH AT LEAST FRIDAY AFTERNOON...FOR A FEW MORE DAYS OF MILD DAYTIME TEMPERATURES AND CLEAR SKIES WITH LIGHT OFFSHORE FLOW. WOULD NOT BE SURPRISED TO SEE TEMPERATURES FLIRT WITH THE 70 DEGREE MARK ACROSS THE WILLAMETTE VALLEY AND INTERSTATE 5 CORRIDOR ON THURSDAY AND PERHAPS FRIDAY AS WELL....THOUGH FRIDAY WILL LIKELY BE A DEGREE OR TWO COOLER TO SOUTH OF SALEM. HOWEVER...WILL START TO SEE CLOUDS MOVE IN FROM THE SOUTHWEST AS A DISTURBANCE BREAKS DOWN THE BLOCKING PATTERN. SIMILAR DEPICTIONS OF THE OVERALL PATTERN WITH SOME SLIGHT TIMING DIFFERENCES...SO UTILIZED A BLEND OF THE 12Z ECMWF AND GFS MODELS...AS THIS WAS ALSO SUPPORTED BY THE GEFS ENSEMBLE MEMBERS. IN TERMS OF THE SENSIBLE WEATHER...THIS MEANS COOLER TEMPERATURES... CLOUDY SKIES...AND A RETURN OF SHOWERS JUST IN TIME FOR THE FIRST WEEKEND OF APRIL. CULLEN && .AVIATION...AN UPPER LEVEL TROUGH WILL SHIFT SOUTHWARD ACROSS THE REGION OVERNIGHT...AND RESULT IN A STABILIZING ATMOSPHERE LATE. THIS SHOULD BRING PREDOMINANTLY VFR CONDITIONS OVERNIGHT...BUT THERE MAY BE SOME TENDENCY FOR A FEW TAF SITES TO EXPERIENCE MVFR AND PERHAPS EVEN PATCHY IFR CONDITIONS TOWARDS 15Z MONDAY. MOS GUIDANCE IS NOT PARTICULARLY KEEN ON IFR FLIGHT RESTRICTIONS...BUT MVFR CONDITIONS CERTAINLY APPEAR LIKE A DISTINCT POSSIBILITY BETWEEN FOR SEVERAL HOURS BETWEEN 12Z AND 21Z MONDAY. ANY MVFR CONDITIONS THAT DO DEVELOP WILL LIKELY LINGER LONGEST AT KSLE AND KEUG DUE TO LOW LEVEL NORTHERLY WINDS UPSLOPING IN THE WILLAMETTE VALLEY. KPDX AND APPROACHES...A SHOWERY AND UNSTABLE PATTERN OVERNIGHT WILL PRODUCE PREDOMINANTLY VFR CONDITIONS. HOWEVER...THE ATMOSPHERE WILL BEGIN TO STABILIZE TOWARDS 15Z MONDAY...AND MAY PRODUCE A PERIOD OF MVFR CONDITIONS. A PERIOD OF IFR CONDITIONS IS NOT OUT OF THE QUESTION...BUT CONFIDENCE IS VERY LOW IN THIS SCENARIO. EXPECT ANY FLIGHT RESTRICTIONS THAT DO DEVELOP TO TREND VFR BETWEEN 19Z AND 22Z MONDAY. /NEUMAN && .MARINE...NORTH-NORTHWESTERLY WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT WILL CONTINUE ACROSS THE WATERS...PARTICULARLY THE OUTER WATERS THROUGH MONDAY. NORTHERLY WINDS SHOULD BACK OFF MONDAY NIGHT BEFORE PEAKING NEAR 20 TO 25 KT DURING THE LATE AFTERNOON AND EVENING HOURS MIDWEEK. A SOUTHERLY WIND REVERSAL SHOULD MOVE NORTHWARD UP THE COAST LATE IN THE WORK WEEK. INCREASING ONSHORE FLOW LATE IN THE WEEKEND OR EARLY NEXT WEEK MAY BRING A RETURN TO MORE ACTIVE WEATHER. IN THE MEANTIME...SEAS ARE CURRENTLY STEEP AND CHOPPY AT 8 TO 9 FT WITH A DOMINANT PERIOD AROUND 8 TO 9 SECONDS. SEAS SHOULD CLIMB A BIT OVERNIGHT AND PEAK AROUND 10 FT BEFORE RELAXING MONDAY. SEAS WILL LIKELY RELAX BELOW 10 FT ACROSS THE CENTRAL OREGON WATERS FIRST ON MONDAY WITH THE NORTHERN WATERS TO FOLLOW. WITH NO MAJOR WEATHER SYSTEMS EXPECTED TO DEVELOP IN THE NORTHEAST PACIFIC NEXT WEEK...EXPECT SEAS TO DROP INTO THE MID SINGLE DIGITS AND BECOME PREDOMINANTLY FRESH SWELL AND/OR WIND DOMINATED. /NEUMAN && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 PM PDT MONDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT MONDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 PM PDT THIS EVENING. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 5 AM TO 10 AM PDT MONDAY. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
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AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
106 AM EDT MON MAR 28 2016 .SYNOPSIS... HIGH PRESSURE OVER NEW ENGLAND WILL MAINTAIN A COOL WEDGE ALONG THE EASTERN SLOPES OF THE APPALACHIANS OVERNIGHT. A COLD FRONT WILL CROSS THROUGH THE AREA EARLY MONDAY. HIGH PRESSURE FOLLOWS THIS FRONT WITH OVERALL DRY WEATHER TUESDAY AND WEDNESDAY BEFORE MOISTURE RETURNS AHEAD OF ANOTHER COLD FRONT BY THURSDAY. && .NEAR TERM /THROUGH TODAY/... AS OF 915 PM EDT SUNDAY... 00Z RNK SOUNDING SHOWING PWAT OF 1.04 INCHES WITH DEEP MOISTURE UP TO 600MB. RADAR HAS SHOWN SOME INTENSIFICATION TO THE RAINFALL ACROSS SOUTHSIDE VIRGINIA INTO THE NC PIEDMONT. OVERALL SOUTHERLY FLOW IN THE MID LEVELS WILL FEED THE RAIN NORTH ACROSS THE PIEDMONT THROUGH EARLY MORNING. MEANWHILE...SHOULD SEE A PERIOD OF RELATIVELY DRY CONDITION OVER THE WEST UNTIL THE MAIN FRONT TRACKS EAST INTO THE MOUNTAINS BY LATE TONIGHT. STILL SOME PATCHY RAIN AND DRIZZLE LIKELY AT TIMES. NO MAJOR CHANGES TO THE REST OF THE FORECAST GRIDS...WITH THE EVENING UPDATE MAINLY FOCUSING THE HIGHER POPS EAST EARLY. PREVIOUS LATE AFTERNOON DISCUSSION... REGIONAL RADAR SHOWS SOLID AREA OF RAIN NEAR THE TRIAD OF NC ESE TO THE TRIANGLE AND MOST OF THE SOUTHEAST. THE LATEST HRRR AND RAP12 INCREASE THE RAIN THREAT OVER THE PIEDMONT TOWARD LATE EVENING WHILE LEAVING THE MOUNTAINS IN SPOTTY LIGHT RAIN AND DRIZZLE. AS SUCH MADE SOME MINOR ADJUSTMENTS TO OUR FORECAST THROUGH THE NIGHT. THE PREVIOUS FORECAST HAD A GOOD HANDLE ON THINGS BUT DECIDED TO LOWER POPS FROM THE PREVIOUS OVER THE WEST PER LATEST TRENDS. HAVE PATCHY DENSE FOG OVER THE BLUE RIDGE THROUGH THE NIGHT AS WELL. PREVIOUS AFTERNOON DISCUSSION... UPPER TROF SEEN ON WATER VAPOR OVER THE MID MISSISSIPPI VALLEY TRACK NORTHEAST TONIGHT AND CLOSES OFF A 500 MB LOWS OVER THE EASTERN GREAT LAKES. THE SHORT WAVE OVER THE LOWER MISSISSIPPI VALLEY WILL TRACK INTO SOUTHEAST VIRGINIA TONIGHT. THE ENTIRE TROF AXIS WILL BE EAST OF THE FORECAST AREA BY LATE MONDAY. BEST CHANCE OF PRECIPITATION WILL BE IN THE SOUTHEAST COUNTY WARNING AREA THIS EVENING THEN IN THE NORTHWEST COUNTIES AFTER MIDNIGHT...WITH A RELATIVE MINIMUM IN PROBABILITIES AND RAINFALL AMOUNTS IN BETWEEN. HAVE MAINTAINED A NARROW PROBABILITY OF THUNDERSTORMS IN THE FAR WEST EARLY MONDAY MORNING ALONG THE FRONT WHERE GUIDANCE WAS SHOWING CAPES IN THE 100-400 J/KG RANGE. SURFACE FRONT AND CHANCE OF PRECIPITATION WILL BE EAST OF THE FORECAST AREA BY 15Z/11AM. CLOUDS WILL HOLD IN OVER THE WESTERN UPSLOPE AREAS FOR THE REST OF MONDAY BUT AIR MASS BEHIND THE FRONT WILL BE DRY ENOUGH SO CLEAR OUT THE REST OF THE COUNTY WARNING AREA. SURFACE WIND BRIEFLY BECOMES SOUTHWEST AS THE WEDGE BREAKS JUST AHEAD OF THE COLD FRONT. WILL USE NON DIURNAL TEMPERATURE TRENDS FOR TONIGHT AND MONDAY. THE STRONGER LOW LEVEL JET STILL FORECAST TO BE ACROSS THE NORTHERN COUNTY WARNING AREA. MOMENTUM TRANSFER OFF OF BUFKIT DID NOT SUPPORT ADVISORY LEVEL WINDS...GUSTS ABOVE 40 KNOTS/46 MPH. BUT WINDS WILL BECOME GUSTY IMMEDIATELY BEHIND THE FRONT. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... AS OF 335 PM EDT SUNDAY... TUESDAY MORNING THE FRONT WILL BE WELL OFF THE COAST AND HIGH PRESSURE WILL BEGIN TO BUILD INTO THE REGION. LIMITED MOISTURE WILL HANG AROUND THE FIRST HALF OF THE DAY BRINGING MOSTLY UPSLOPE CLOUDS TO THE MOUNTAINS SCATTERING OUT AS YOU HEAD TOWARD THE BLUE RIDGE. CANT RULE OUT A STRAY LIGHT SHOWER OR FLURRY ACROSS THE FAVORED UPSLOPE REGIONS OF THE WESTERN SLOPES HOWEVER MOISTURE WILL BE SHALLOW AND WONT LAST LONG SO JUST LOW CHANCE POPS IN FOR TUESDAY MORNING. THE BACK HALF OF TUESDAY AND THE ENTIRE DAY WEDNESDAY WILL BE DRY. DESPITE THE COLDER AIR FILTERING IN MONDAY NIGHT...GUSTY NORTHWEST WINDS SHOULD HOLD THE VAST MAJORITY OF THE REGION ABOVE FREEZING TUESDAY MORNING...WITH THE EXCEPTION BEING WESTERN GREENBRIER COUNTY WHERE A FEW LOCATIONS MAY DIP JUST BELOW FREEZING. HIGH TEMPS TUESDAY WILL RANGE FROM THE LOW TO MID 50S ACROSS THE MOUNTAINS AND LOW TO MID 60S EAST OF THE BLUE RIDGE. AS THE SURFACE HIGH DRIFTS SOUTHEAST FROM THE GREAT LAKES TO NORTHERN VA BY WEDNESDAY MORNING WINDS WILL BECOME LIGHT AND WITH CLEAR SKIES EXPECT MANY VALLEY LOCATIONS IN THE MOUNTAINS TO FALL RIGHT AT OR JUST BELOW FREEZING. WARM SOUTHERLY FLOW WEDNESDAY AFTERNOON WILL ALLOW TEMPS TO REBOUND TO THE 60S ACROSS MUCH OF THE AREA. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 335 PM EDT SUNDAY... DEEPENING LOW THURSDAY MORNING WILL BE MARCHING TOWARDS THE GREAT LAKES REGION...TRAILING A COLD FRONT BACK THROUGH THE OHIO VALLEY. OUT AHEAD OF THE FRONT...A WARM SOUTHERLY FLOW AND DECENT INSTABILITY WILL BRING AN AREA OF SHOWERS AND SCATTERED THUNDERSTORMS TO THE AREA ON THURSDAY. RIGHT NOW THE BEST CHANCE FOR THUNDERSTORMS LOOKS TO BE DURING THE AFTERNOON AND EARLY EVENING ON THURSDAY. TOO EARLY TO PIN DOWN RAINFALL AMOUNTS AT THIS POINT...BUT EARLY FORECASTS FROM WPC SHOW AROUND AN INCH ACROSS MOST OF THE REGION WITH ALMOST TWO INCHES ACROSS NW NC. THE COLD FRONT WILL CROSS THE AREA ON FRIDAY BRINGING DRIER AND COOLER CONDITIONS FOR THE WEEKEND. MODELS ARE HINTING AT SOME UPSLOPE PRECIP DURING THE WEEKEND ESPECIALLY WITH A REINFORCING SHOT OF COLDER AIR LATE SATURDAY NIGHT INTO SUNDAY MORNING. FOR NOW JUST MENTION LOW CHANCE POPS ACROSS THE FAVORED UPSLOPE REGIONS. TEMPS WILL REMAIN NEAR NORMAL UNTIL THE COLD FRONT CROSSES ON FRIDAY AND THEN WILL RUN 5-10 DEGREES BELOW NORMAL THROUGH THE WEEKEND. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... AS OF 1245 AM EDT MONDAY... POOR AVIATION CONDITIONS EXPECTED TO CONTINUE THROUGH THE FIRST HALF OF THE VALID TAF PERIOD OVERNIGHT...THEN IMPROVING CONDITIONS MONDAY MORNING INTO THE AFTERNOON. HOWEVER...WIND WILL BE AN ISSUE AT ALL TAF SITES FROM MID TO LATE MORNING MONDAY INTO THE AFTERNOON. OTHERWISE WIDESPREAD MVFR TO IFR/LIFR CIGS WILL CONTINUE WITHIN A LINGERING LOW LEVEL WEDGE AND AHEAD OF AN APPROACHING UPSTREAM COLD FRONT OVERNIGHT. EXPECT BEST COVERAGE OF SHOWERS WITH AN INITIAL IMPULSE TO AFFECT THE KLYH-KDAN CORRIDOR THROUGH ABOUT 7Z/3AM WITH MVFR VSBYS IN RAIN/FOG AT TIMES. ELSEWHERE...APPEARS A MIX OF FOG AND PATCHY SHOWERS TO KEEP VFR TO MVFR VSBYS IN PLACE WITH VARIATION IN VSBYS LIKELY AS THE RAINFALL PASSES AND FOG REDEVELOPS. NEXT BAND OF SHOWERS/STORMS WITH THE COLD FRONT TO THE WEST WILL ATTEMPT TO WORK INTO THE WEST BEFORE DAYBREAK MONDAY. THESE SHOWERS LOOK TO AFFECT KLWB/KBLF AFTER 09Z/5AM...BUT LIKELY WILL NOT MAKE IT FAR ACROSS THE RIDGES EARLY MONDAY BEFORE FADING PER LATEST MODEL SOLUTIONS. THINK MOST DEEP CONVECTION WITH THIS BAND LIKELY TO EITHER PASS NORTH OR WEAKEN SO WONT INCLUDE ANY TSRA MENTION FOR NOW. ONCE THE FRONT PASSES THE REGION FROM WEST TO EAST DURING THE EARLY TO MID MORNING TIME FRAME...CIGS WILL QUICKLY IMPROVE TO VFR EAST OF THE BLUE RIDGE...LINGER IN THE IFR-MVFR RANGE FOR A FEW HOURS AROUND KBCB...THEN IMPROVE TO VFR BY 16Z/NOON...BUT LIKELY REMAIN MVFR UNTIL MID OR LATE AFTERNOON ACROSS EASTERN WV INTO FAR SOUTHWEST VA BECAUSE OF UPSLOPE FLOW. AFTER THE FRONTAL PASSAGE...EXPECT WINDS TO BECOME NW 15-25KTS WITH GUSTS 28-35KTS FROM MID MORNING THROUGH LATE IN THE DAY. MVFR CIGS MAY LINGER ACROSS KBLF/KLWB INTO MONDAY NIGHT WITH VFR EXPECTED ELSEWHERE AS HIGH PRESSURE CONTINUES TO BUILD IN. HOWEVER STRONG NW WINDS WILL CONTINUE WITH GUSTS TO 20-25 KTS OR HIGHER ALONG THE RIDGES INCLUDING KBLF/KROA/KBCB BUT LIGHTER EAST OF THE BLUE RIDGE. EXTENDED DISCUSSION... VFR SHOULD THEN PREVAIL TUESDAY INTO WEDNESDAY UNDER HIGH PRESSURE BEHIND THE FRONT. DEEP MOISTURE RETURNS LATE WEDNESDAY NIGHT AND CONTINUES ON THURSDAY AHEAD OF ANOTHER STRONG COLD FRONT. THIS LIKELY TO RESULT IN WIDESPREAD SUB-VFR IN SHOWERS AND THUNDERSTORMS WITH LOW CIGS THROUGH THURSDAY. THIS SYSTEM IS EXPECTED TO MOVE OUT OF THE AREA WITH VFR CONDITIONS EAST OF THE BLUE RIDGE AND MVFR CEILINGS IN THE MOUNTAINS ON FRIDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS/JH NEAR TERM...AMS/WP SHORT TERM...CF LONG TERM...CF/RCS AVIATION...AMS/JH/RAB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
625 PM CDT TUE MAR 29 2016 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 335 PM CDT TUE MAR 29 2016 MAIN FORECAST CONCERNS FOR TONIGHT ARE ON THE ARRIVAL OF SHOWERS AND ISOLATED THUNDERSTORMS. FOCUS THEN TURNS TO PERIODS OF SHOWERS AND SCATTERED THUNDERSTORMS WEDNESDAY INTO WEDNESDAY NIGHT WITH THE POTENTIAL FOR 1 TO 1.3 INCHES OF RAINFALL. LATEST RADAR IMAGERY ACROSS THE REGION SHOWED SHOWERS AND A FEW THUNDERSTORMS ACROSS PORTIONS OF SOUTHEAST SOUTH DAKOTA INTO NORTHWEST IOWA...WITH AN AREA OF LIGHT RETURNS NOTED ACROSS MUCH OF NORTHERN IOWA. THESE RETURNS WILL CONTINUE TO LIFT NORTHWARD LATE THIS AFTERNOON INTO THIS EVENING. WE HAVE NOT SEEN ANY PRECIPITATION REPORTED OUT OF THE RETURNS MOVING INTO NORTHEAST IOWA...BUT SUSPECT THERE ARE SOME LIGHT SPRINKLES MAKING IT TO THE SURFACE. UPPER LEVEL FORCING AND 850 MB MOISTURE TRANSPORT INCREASE ACROSS THE AREA TONIGHT WITH SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPING. EXTREME NORTHEAST IOWA AND PORTIONS OF SOUTHWEST WISCONSIN PROBABLY WON/T SEE ANY PRECIPITATION UNTIL LATE TONIGHT INTO EARLY WEDNESDAY MORNING. LOW PRESSURE THEN LIFTS NORTHEAST OUT OF THE CENTRAL PLAIN AND INTO THE UPPER MISSISSIPPI RIVER VALLEY DURING THE DAY ON WEDNESDAY. INSTABILITY INCREASES ACROSS THE AREA...ESPECIALLY ALONG AND SOUTH OF INTERSTATE 90...WHERE 0-1 KM MUCAPE VALUES INCREASE INTO THE 250-500 J/KG RANGE. 0-6 KM BULK SHEAR ALSO INCREASES TO 45 TO 50 KTS. WE AREN/T EXPECTING SURFACE BASED STORMS SO WE WILL ONLY BE UTILIZING CAPE AND SHEAR FROM MAINLY ABOVE 925 MB. A FEW STORMS COULD BE STRONG WITH SMALL HAIL...ESPECIALLY ACROSS NORTHEAST IOWA INTO EXTREME SOUTHWEST WISCONSIN WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING. THROUGH NOON WEDNESDAY RAINFALL AMOUNTS SHOULD RANGE FROM AROUND 0.75 INCH ACROSS NORTHWEST SECTIONS OF THE FORECAST AREAS TO AROUND 0.40 INCHES ACROSS SOUTHEASTERN SECTIONS. THE BULK OF THE RAINFALL LOOKS TO ARRIVE LATE WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. BY THE TIME IT TAPERS OFF LATE WEDNESDAY NIGHT INTO THURSDAY MORNING WE SHOULD SEE RAINFALL TOTALS OF 1 INCH TO 1.3 INCHES. THIS WILL CAUSE RISES ON AREA RIVERS...BUT WE AREN/T EXPECTING FLOODING AT THIS TIME. IF RAINFALL WOULD BECOME MORE CONCENTRATED ALONG THE FRONTAL BOUNDARY WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT...WE COULD SEE TOTALS APPROACH 2 INCHES AND THIS COULD CREATE SOME CONCERNS. SEE HYDROLOGY SECTION BELOW FOR MORE INFORMATION. THE RAIN MAY SWITCH OVER TO LIGHT SNOW NORTH OF INTERSTATE 90 BRIEFLY LATE WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING BEFORE ENDING...BUT NOT EXPECTING SIGNIFICANT ACCUMULATIONS AT THIS TIME. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 335 PM CDT TUE MAR 29 2016 THE LOW PULLS EAST OF THE REGION ON FRIDAY WITH ANY LINGERING RAIN TAPERING OFF DURING THE AFTERNOON HOURS. MUCH COOLER AIR MOVES IN AS A TROUGH SETTLES ACROSS THE REGION THURSDAY INTO FRIDAY. WE WILL ENTER A PERIOD OF NORTHEAST FLOW AND WINDY CONDITIONS AT TIMES AS WE GO INTO THE WEEKEND. A COUPLE OF SYSTEMS LOOK TO BRING RAIN OR SNOW TO THE REGION. A WEAK TROUGH MOVES THROUGH ON FRIDAY...BUT A STRONGER SYSTEM LOOKS TO RACE THROUGH LATE FRIDAY NIGHT INTO SATURDAY MORNING. THE LATE FRIDAY NIGHT AND SATURDAY MORNING SYSTEM COULD HAVE SOME SNOWFALL FOR THE REGION ALONG WITH STRONG NORTHWEST WINDS IN ITS WAKE. EXACT DETAILS ARE A LITTLE UNCLEAR AT THIS TIME...WILL HAVE TO KEEP A CLOSE EYE ON THIS. COOL NORTHWEST FLOW THEN CONTINUES THROUGH MUCH OF NEXT WEEK WITH HIGHS MAINLY IN THE 40S AND LOWS IN THE 20S. ANOTHER WEAK SYSTEM COULD BRING SNOW OR RAIN TO THE REGION SUNDAY NIGHT INTO MONDAY. A LOT OF SPREAD IN THE FORECAST MODEL SOLUTIONS THAT FAR OUT...SO WILL LEAN TOWARD A MODEL CONSENSUS BLEND FOR PRECIPITATION CHANCES. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 625 PM CDT TUE MAR 29 2016 THE FIRST SHORT WAVE TROUGH TOPPING THE UPPER LEVEL RIDGE OVER THE CENTRAL PORTION OF THE COUNTRY HAS BEEN PRODUCING SOME RADAR RETURNS OVER THE AREA. OBSERVATIONS AND WEB CAMS INDICATE JUST SOME SPRINKLES FROM THESE AND EXPECT THAT THEY WILL BE PAST BOTH TAF SITES BY 00Z. THE NEXT ROUND OF CONVECTION WAS OVER NORTHWEST IOWA AND WAS MOVING NORTHEAST. THE 30.22Z HRRR AND 30.21Z CR-HRRR BOTH SHOW THIS LIFTING TOWARD THE TWIN CITIES AND MISSING BOTH TAF SITES THIS EVENING. ADDITIONAL ACTIVITY IS EXPECTED TO DEVELOP LATE THIS EVENING AND CONTINUE OVERNIGHT INTO WEDNESDAY MORNING AS THE LOW LEVEL MOISTURE TRANSPORT INCREASES AND BECOMES FOCUSED ON THE AREA. SOME POSSIBILITY OF THUNDER LATE TONIGHT INTO WEDNESDAY MORNING...BUT THE 29.18Z NAM SOUNDINGS DO NOT SHOW MUCH CAPE SO CONFIDENCE TO INCLUDE IS TOO LOW AT THIS TIME. GOOD AGREEMENT BETWEEN THE HRRR...CR-HRRR AND 29.18Z CR-NAM NEST THAT THIS OVERNIGHT ACTIVITY SHOULD MOVE PAST BOTH TAF SITES BY THE MIDDLE OF THE WEDNESDAY MORNING WITH THE POSSIBILITY OF SOME ADDITIONAL SCATTERED ACTIVITY THROUGH THE DAY...BUT NOTHING THAT LOOKS ALL THAT ORGANIZED. WILL DROP BACK TO JUST A VCSH BEHIND THIS ACTIVITY BUT THIS LOOKS TO SATURATE THE LOW LEVELS ENOUGH TO TAKE THE VISIBILITY DOWN TO MVFR WITH SOME FOG WITH IFR CEILINGS. && .HYDROLOGY...LATE TONIGHT THROUGH THURSDAY ISSUED AT 335 PM CDT TUE MAR 29 2016 PERIODS OF SHOWERS AND THUNDERSTORMS WILL DROP 1 TO 1.3 INCHES OF RAINFALL ACROSS THE AREA FROM TONIGHT THROUGH EARLY THURSDAY. WITH NEARLY SATURATED SOILS...MUCH OF THE RAIN WILL RUN OFF. ALSO...MANY RIVERS AND STREAMS ARE ALREADY ELEVATED FROM RECENT PRECIPITATION. THESE FACTORS COMBINED WITH THE EXPECTED RAINFALL WILL LEAD TO SIGNIFICANT WITHIN BANK RISES ON MANY RIVERS. WE ARE NOT EXPECTING FLOODING AT THIS TIME...BUT THIS COULD CHANGE IF THE RAINFALL BECOMES MORE CONCENTRATED ALONG RIVER BASINS. MONITOR RIVER FORECASTS CLOSELY OVER THE NEXT 24-48 HOURS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...WETENKAMP LONG TERM...WETENKAMP AVIATION...04 HYDROLOGY...WETENKAMP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1245 PM CDT MON MAR 28 2016 UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND TUESDAY ISSUED AT 405 AM CDT MON MAR 28 2016 CLOUDS WERE ON THE DECREASE EARLY THIS MORNING ACROSS PORTIONS OF NORTH-CENTRAL WISCONSIN...MAINLY WEST OF A MEDFORD TO EAGLE RIVER LINE. THIS CLEARING SHOULD CONTINUE TO SPREAD SOUTH AND EAST ACROSS NORTH-CENTRAL AND CENTRAL WISCONSIN THROUGH SUNRISE... THEN ACROSS NORTHEAST WISCONSIN WITHIN A FEW HOURS AFTER SUNRISE. WHERE SKIES DO CLEAR EARLY THIS MORNING ACROSS NORTH-CENTRAL WISCONSIN...PATCHY FOG IS EXPECTED TO DEVELOP. COULD NOT RULE OUT A FEW ISOLATED SPOTS DOWN TO A QUARTER OF A MILE...BUT ENOUGH WIND ACROSS THE REGION SHOULD KEEP IT FROM BECOMING WIDESPREAD. LATER THIS AFTERNOON...A WEAK SURFACE BOUNDARY DROPS INTO NORTHERN WISCONSIN. LAST RUN OR TWO OF THE GFS DEPICTED SOME SPOTTY LIGHT PRECIPITATION ACROSS NORTH-CENTRAL WISCONSIN. THE LATEST RUN OF THE HRRR DEPICTED SOME LIGHT RAIN ALONG THIS BOUNDARY ACROSS LINCOLN AND ONEIDA COUNTIES AROUND 21-22Z. BUFKIT SOUNDINGS INDICATED STEEP LAPSE OF 8C FROM 950 TO 700MB AT RHINELANDER. BASED ON THE STEEP MID LEVEL LAPSE RATES...AND SURFACE CONVERGENCE ALONG THE BOUNDARY WAS ENOUGH SUPPORT TO ADD A CHANCE OF SPRINKLES ACROSS NORTH-CENTRAL WISCONSIN LATER THIS AFTERNOON INTO EARLY THIS EVENING. DID BUMP UP CLOUD COVER SOME ALONG THIS BOUNDARY BASED ON THE LAYER CU RULE. DAY SHIFT MAY NEED TO INCREASE THEM A LITTLE BIT MORE AS THE CU RULE WOULD SUGGEST SKIES WOULD GO MOSTLY CLOUDY FOR A PERIOD OF TIME THIS AFTERNOON ACROSS THE NORTH. ANY LINGERING SPRINKLES SHOULD END SHORTLY AFTER SUNSET...ALONG WITH THE CLOUDS DISSIPATING AFTER SUNSET. THE COMBINATION OF MOSTLY CLEAR SKIES...LIGHT WINDS AND SOME SNOW COVER ACROSS THE NORTH SHOULD ALLOW TEMPERATURES TO PLUMMET LATER TONIGHT. WENT AT OR SLIGHTLY BELOW GUIDANCE FOR LOWS. ON TUESDAY...INCREASING SOUTH TO SOUTHEAST WINDS ARE EXPECTED WITH HIGHS IN THE UPPER 40S TO MIDDLE 50S. READINGS WILL BE CONSIDERABLY COOLER NEAR THE BAY AND LAKE DUE TO THE SOUTHERLY WIND TRAJECTORY. HIGHS NEAR LAKE MICHIGAN WILL BARELY CLIMB ABOVE 40. .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY ISSUED AT 405 AM CDT MON MAR 28 2016 EXPECT PLENTY OF CHANCES FOR PRECIPITATION THROUGHOUT THIS PART OF THE FORECAST. A CLOSED 500MB LOW THAT IS FORECAST TO REACH THE DESERT SOUTHWEST TODAY WILL MOVE INTO THE GREAT LAKES REGION WEDNESDAY NIGHT/THURSDAY...ATTEMPTING TO PHASE WITH A SHORT WAVE IN THE NORTHERN BRANCH FLOW ALOFT. WARM ADVECTION AND INCREASING MOISTURE AHEAD OF AN APPROACHING SURFACE SYSTEM WILL BRING RAIN CHANCES TO THE FORECAST AREA TUESDAY NIGHT. EXPECT SHOWERS WEDNESDAY INTO WEDNESDAY EVENING...AND MODELS INDICATED SOME MINOR CAPE SO HAVE ALSO INCLUDED A MENTION OF THUNDER THROUGH 06Z THURSDAY. MOST OF THE FORECAST AREA WILL SEE RAINFALL TOTALS AROUND AN INCH FROM 12Z WEDNESDAY THROUGH 12Z THURSDAY...WHICH WILL LEAD TO RISING RIVER LEVELS. MUCH COLDER AIR WILL WRAP AROUND THE DEPARTING SURFACE LOW AS IT PASSES TO THE NORTHEAST ON THURSDAY...CHANGING PRECIPITATION TO MAINLY SNOW BY THURSDAY NIGHT. A CLIPPER SYSTEM WILL QUICKLY MOVE IN BEHIND THE DEPARTING SYSTEM...KEEPING A CHANCE FOR PRECIPITATION IN THE FORECAST INTO THE WEEKEND. THE AIRMASS WILL BE COLD ENOUGH FOR MOSTLY SNOW...MAINLY ACROSS NORTHERN WISCONSIN...BUT AMOUNTS ARE UNCERTAIN THIS FAR IN ADVANCE. TEMPERATURES WILL BE WARMER THAN NORMAL AT THE START OF THE FORECAST PERIOD...BUT QUICKLY DROP BELOW NORMAL FOR THE LATTER HALF OF THIS WEEK AND THE WEEKEND. HIGHS ARE ONLY EXPECTED TO BE IN THE UPPER 20S AND 30S ACROSS THE AREA ON SUNDAY. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1245 PM CDT MON MAR 28 2016 VFR CONDITIONS EXPECTED THROUGH TUESDAY. AN UPPER LEVEL DISTURBANCE WILL PRODUCE SOME MIDDLE CLOUDS WITH 7000 TO 10000 FT BASES THIS AFTERNOON AND EVENING. VIRGA FALLING FROM ANY OF THESE CLOUDS COULD PRODUCE DOWNDRAFTS THAT MIGHT AFFECT LIGHT AIRCRAFT. PATCHY GROUND FOG POSSIBLE AFTER 09Z TONIGHT ESPECIALLY OVER AREAS WITH SNOW COVER. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....ECKBERG LONG TERM......MG AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
634 AM CDT MON MAR 28 2016 UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND TUESDAY ISSUED AT 405 AM CDT MON MAR 28 2016 CLOUDS WERE ON THE DECREASE EARLY THIS MORNING ACROSS PORTIONS OF NORTH-CENTRAL WISCONSIN...MAINLY WEST OF A MEDFORD TO EAGLE RIVER LINE. THIS CLEARING SHOULD CONTINUE TO SPREAD SOUTH AND EAST ACROSS NORTH-CENTRAL AND CENTRAL WISCONSIN THROUGH SUNRISE... THEN ACROSS NORTHEAST WISCONSIN WITHIN A FEW HOURS AFTER SUNRISE. WHERE SKIES DO CLEAR EARLY THIS MORNING ACROSS NORTH-CENTRAL WISCONSIN...PATCHY FOG IS EXPECTED TO DEVELOP. COULD NOT RULE OUT A FEW ISOLATED SPOTS DOWN TO A QUARTER OF A MILE...BUT ENOUGH WIND ACROSS THE REGION SHOULD KEEP IT FROM BECOMING WIDESPREAD. LATER THIS AFTERNOON...A WEAK SURFACE BOUNDARY DROPS INTO NORTHERN WISCONSIN. LAST RUN OR TWO OF THE GFS DEPICTED SOME SPOTTY LIGHT PRECIPITATION ACROSS NORTH-CENTRAL WISCONSIN. THE LATEST RUN OF THE HRRR DEPICTED SOME LIGHT RAIN ALONG THIS BOUNDARY ACROSS LINCOLN AND ONEIDA COUNTIES AROUND 21-22Z. BUFKIT SOUNDINGS INDICATED STEEP LAPSE OF 8C FROM 950 TO 700MB AT RHINELANDER. BASED ON THE STEEP MID LEVEL LAPSE RATES...AND SURFACE CONVERGENCE ALONG THE BOUNDARY WAS ENOUGH SUPPORT TO ADD A CHANCE OF SPRINKLES ACROSS NORTH-CENTRAL WISCONSIN LATER THIS AFTERNOON INTO EARLY THIS EVENING. DID BUMP UP CLOUD COVER SOME ALONG THIS BOUNDARY BASED ON THE LAYER CU RULE. DAY SHIFT MAY NEED TO INCREASE THEM A LITTLE BIT MORE AS THE CU RULE WOULD SUGGEST SKIES WOULD GO MOSTLY CLOUDY FOR A PERIOD OF TIME THIS AFTERNOON ACROSS THE NORTH. ANY LINGERING SPRINKLES SHOULD END SHORTLY AFTER SUNSET...ALONG WITH THE CLOUDS DISSIPATING AFTER SUNSET. THE COMBINATION OF MOSTLY CLEAR SKIES...LIGHT WINDS AND SOME SNOW COVER ACROSS THE NORTH SHOULD ALLOW TEMPERATURES TO PLUMMET LATER TONIGHT. WENT AT OR SLIGHTLY BELOW GUIDANCE FOR LOWS. ON TUESDAY...INCREASING SOUTH TO SOUTHEAST WINDS ARE EXPECTED WITH HIGHS IN THE UPPER 40S TO MIDDLE 50S. READINGS WILL BE CONSIDERABLY COOLER NEAR THE BAY AND LAKE DUE TO THE SOUTHERLY WIND TRAJECTORY. HIGHS NEAR LAKE MICHIGAN WILL BARELY CLIMB ABOVE 40. .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY ISSUED AT 405 AM CDT MON MAR 28 2016 EXPECT PLENTY OF CHANCES FOR PRECIPITATION THROUGHOUT THIS PART OF THE FORECAST. A CLOSED 500MB LOW THAT IS FORECAST TO REACH THE DESERT SOUTHWEST TODAY WILL MOVE INTO THE GREAT LAKES REGION WEDNESDAY NIGHT/THURSDAY...ATTEMPTING TO PHASE WITH A SHORT WAVE IN THE NORTHERN BRANCH FLOW ALOFT. WARM ADVECTION AND INCREASING MOISTURE AHEAD OF AN APPROACHING SURFACE SYSTEM WILL BRING RAIN CHANCES TO THE FORECAST AREA TUESDAY NIGHT. EXPECT SHOWERS WEDNESDAY INTO WEDNESDAY EVENING...AND MODELS INDICATED SOME MINOR CAPE SO HAVE ALSO INCLUDED A MENTION OF THUNDER THROUGH 06Z THURSDAY. MOST OF THE FORECAST AREA WILL SEE RAINFALL TOTALS AROUND AN INCH FROM 12Z WEDNESDAY THROUGH 12Z THURSDAY...WHICH WILL LEAD TO RISING RIVER LEVELS. MUCH COLDER AIR WILL WRAP AROUND THE DEPARTING SURFACE LOW AS IT PASSES TO THE NORTHEAST ON THURSDAY...CHANGING PRECIPITATION TO MAINLY SNOW BY THURSDAY NIGHT. A CLIPPER SYSTEM WILL QUICKLY MOVE IN BEHIND THE DEPARTING SYSTEM...KEEPING A CHANCE FOR PRECIPITATION IN THE FORECAST INTO THE WEEKEND. THE AIRMASS WILL BE COLD ENOUGH FOR MOSTLY SNOW...MAINLY ACROSS NORTHERN WISCONSIN...BUT AMOUNTS ARE UNCERTAIN THIS FAR IN ADVANCE. TEMPERATURES WILL BE WARMER THAN NORMAL AT THE START OF THE FORECAST PERIOD...BUT QUICKLY DROP BELOW NORMAL FOR THE LATTER HALF OF THIS WEEK AND THE WEEKEND. HIGHS ARE ONLY EXPECTED TO BE IN THE UPPER 20S AND 30S ACROSS THE AREA ON SUNDAY. && .AVIATION...FOR 12Z TAF ISSUANCE ISSUED AT 617 AM CDT MON MAR 28 2016 PATCHY MVFR CIGS WILL GIVE WAY TO VFR CONDITIONS THIS MORNING AS DRIER AIR WORKS INTO THE REGION. THE ONLY EXCEPTION MAY BE ACROSS FAR NORTH-CENTRAL WISCONSIN WHERE SOME FOG MAY STILL DEVELOP FOR AN HOUR OR TWO AFTER SUNRISE. A MID DECK OF CLOUDS WILL MOVE ACROSS THE AREA THIS MORNING...THEN FAIR WEATHER CUMULUS CLOUDS SHOULD DEVELOP LATE MORNING AND AFTERNOON ACROSS NORTHERN WISCONSIN. THE LAYER CU RULE OFF THE MODELS WOULD SUGGEST SKIES WILL BECOME MOSTLY CLOUDY FOR A PERIOD OF TIME THIS AFTERNOON. A FEW SPRINKLES ARE POSSIBLE ACROSS NORTH-CENTRAL WISCONSIN...BUT DID NOT INCLUDE THEM IN THE 12Z TAFS AT KRHI/KAUW/KCWA. PATCHY FOG COULD DEVELOP LATE MONDAY NIGHT ACROSS EASTERN WISCONSIN. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....ECKBERG LONG TERM......MG AVIATION.......ECKBERG
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND TUESDAY ISSUED AT 405 AM CDT MON MAR 28 2016 CLOUDS WERE ON THE DECREASE EARLY THIS MORNING ACROSS PORTIONS OF NORTH-CENTRAL WISCONSIN...MAINLY WEST OF A MEDFORD TO EAGLE RIVER LINE. THIS CLEARING SHOULD CONTINUE TO SPREAD SOUTH AND EAST ACROSS NORTH-CENTRAL AND CENTRAL WISCONSIN THROUGH SUNRISE... THEN ACROSS NORTHEAST WISCONSIN WITHIN A FEW HOURS AFTER SUNRISE. WHERE SKIES DO CLEAR EARLY THIS MORNING ACROSS NORTH-CENTRAL WISCONSIN...PATCHY FOG IS EXPECTED TO DEVELOP. COULD NOT RULE OUT A FEW ISOLATED SPOTS DOWN TO A QUARTER OF A MILE...BUT ENOUGH WIND ACROSS THE REGION SHOULD KEEP IT FROM BECOMING WIDESPREAD. LATER THIS AFTERNOON...A WEAK SURFACE BOUNDARY DROPS INTO NORTHERN WISCONSIN. LAST RUN OR TWO OF THE GFS DEPICTED SOME SPOTTY LIGHT PRECIPITATION ACROSS NORTH-CENTRAL WISCONSIN. THE LATEST RUN OF THE HRRR DEPICTED SOME LIGHT RAIN ALONG THIS BOUNDARY ACROSS LINCOLN AND ONEIDA COUNTIES AROUND 21-22Z. BUFKIT SOUNDINGS INDICATED STEEP LAPSE OF 8C FROM 950 TO 700MB AT RHINELANDER. BASED ON THE STEEP MID LEVEL LAPSE RATES...AND SURFACE CONVERGENCE ALONG THE BOUNDARY WAS ENOUGH SUPPORT TO ADD A CHANCE OF SPRINKLES ACROSS NORTH-CENTRAL WISCONSIN LATER THIS AFTERNOON INTO EARLY THIS EVENING. DID BUMP UP CLOUD COVER SOME ALONG THIS BOUNDARY BASED ON THE LAYER CU RULE. DAY SHIFT MAY NEED TO INCREASE THEM A LITTLE BIT MORE AS THE CU RULE WOULD SUGGEST SKIES WOULD GO MOSTLY CLOUDY FOR A PERIOD OF TIME THIS AFTERNOON ACROSS THE NORTH. ANY LINGERING SPRINKLES SHOULD END SHORTLY AFTER SUNSET...ALONG WITH THE CLOUDS DISSIPATING AFTER SUNSET. THE COMBINATION OF MOSTLY CLEAR SKIES...LIGHT WINDS AND SOME SNOW COVER ACROSS THE NORTH SHOULD ALLOW TEMPERATURES TO PLUMMET LATER TONIGHT. WENT AT OR SLIGHTLY BELOW GUIDANCE FOR LOWS. ON TUESDAY...INCREASING SOUTH TO SOUTHEAST WINDS ARE EXPECTED WITH HIGHS IN THE UPPER 40S TO MIDDLE 50S. READINGS WILL BE CONSIDERABLY COOLER NEAR THE BAY AND LAKE DUE TO THE SOUTHERLY WIND TRAJECTORY. HIGHS NEAR LAKE MICHIGAN WILL BARELY CLIMB ABOVE 40. .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY ISSUED AT 405 AM CDT MON MAR 28 2016 EXPECT PLENTY OF CHANCES FOR PRECIPITATION THROUGHOUT THIS PART OF THE FORECAST. A CLOSED 500MB LOW THAT IS FORECAST TO REACH THE DESERT SOUTHWEST TODAY WILL MOVE INTO THE GREAT LAKES REGION WEDNESDAY NIGHT/THURSDAY...ATTEMPTING TO PHASE WITH A SHORT WAVE IN THE NORTHERN BRANCH FLOW ALOFT. WARM ADVECTION AND INCREASING MOISTURE AHEAD OF AN APPROACHING SURFACE SYSTEM WILL BRING RAIN CHANCES TO THE FORECAST AREA TUESDAY NIGHT. EXPECT SHOWERS WEDNESDAY INTO WEDNESDAY EVENING...AND MODELS INDICATED SOME MINOR CAPE SO HAVE ALSO INCLUDED A MENTION OF THUNDER THROUGH 06Z THURSDAY. MOST OF THE FORECAST AREA WILL SEE RAINFALL TOTALS AROUND AN INCH FROM 12Z WEDNESDAY THROUGH 12Z THURSDAY...WHICH WILL LEAD TO RISING RIVER LEVELS. MUCH COLDER AIR WILL WRAP AROUND THE DEPARTING SURFACE LOW AS IT PASSES TO THE NORTHEAST ON THURSDAY...CHANGING PRECIPITATION TO MAINLY SNOW BY THURSDAY NIGHT. A CLIPPER SYSTEM WILL QUICKLY MOVE IN BEHIND THE DEPARTING SYSTEM...KEEPING A CHANCE FOR PRECIPITATION IN THE FORECAST INTO THE WEEKEND. THE AIRMASS WILL BE COLD ENOUGH FOR MOSTLY SNOW...MAINLY ACROSS NORTHERN WISCONSIN...BUT AMOUNTS ARE UNCERTAIN THIS FAR IN ADVANCE. TEMPERATURES WILL BE WARMER THAN NORMAL AT THE START OF THE FORECAST PERIOD...BUT QUICKLY DROP BELOW NORMAL FOR THE LATTER HALF OF THIS WEEK AND THE WEEKEND. HIGHS ARE ONLY EXPECTED TO BE IN THE UPPER 20S AND 30S ACROSS THE AREA ON SUNDAY. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1120 PM CDT SUN MAR 27 2016 MAINLY MVFR CIGS TONIGHT OVER CENTRAL WISCONSIN AND MAINLY IFR CIGS OVER NORTH CENTRAL WISCONSIN AND EASTERN WISCONSIN OVERNIGHT. PATCHY MVFR/IFR VSBYS DUE TO FOG WILL LINGER OVER EASTERN WISCONSIN...AND MAY DEVELOP OVER CENTRAL WISCONSIN TOWARD MONDAY MORNING. HIGH PRESSURE BUILDING INTO THE AREA MONDAY WILL IMPROVE CONDITIONS TO VFR CATEGORIES. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....ECKBERG LONG TERM......MG AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
244 AM MST WED MAR 30 2016 .SYNOPSIS... A LOW PRESSURE SYSTEM OVER THE WESTERN STATES WILL KEEP MUCH COOLER TEMPERATURES IN PLACE TODAY WITH HIGHS IN THE UPPER 60S TO LOW 70S ACROSS THE LOWER DESERTS. MEAGER PRECIPITATION CHANCES WILL BE LIMITED TO THE HIGHER TERRAIN THROUGH FRIDAY. A WARMING TREND WILL BEGIN THURSDAY AS THE LOW PRESSURE SYSTEM BEGINS TO EXIT THE REGION. A RIDGE OF HIGH PRESSURE BUILDS OVER THE WESTERN STATES THIS WEEKEND WITH TEMPERATURES CLIMBING WELL ABOVE NORMAL. HIGHS WILL REACH THE UPPER 80S TO LOW 90S SUNDAY AND MONDAY. && .DISCUSSION... TODAY AND THURSDAY... THE UPPER LOW/TROUGH AFFECTING MUCH OF THE WESTERN STATES IS CENTERED NEAR WEST-CENTRAL UTAH EARLY THIS MORNING. UPSTREAM OF THAT IS A RIDGE WITH AN AXIS LOCATED OFFSHORE. CLOSER TO HOME A VORT MAX WITHIN THE TROUGH HAS MOVED FROM SOUTHEAST CALIFORNIA INTO WESTERN ARIZONA. SHOWER ACTIVITY WITH THAT FEATURE HAS BEEN QUITE WEAK BUT ADDED A MENTION OF SLIGHT CHANCE...FOR VERY LIGHT PRECIP/SPRINKLES OVER PORTIONS OF PORTIONS OF SOUTHWEST ARIZONA AND NORTHWEST MARICOPA COUNTY FOR THE PRE-DAWN HOURS. FURTHER EAST THERE IS ALSO A BAND OF CLOUDINESS THAT HAS DEVELOPED OVER PORTIONS OF SOUTH-CENTRAL ARIZONA...SIMILAR TO YESTERDAY MORNING BUT NOT AFFECTING NEAR AS MUCH OF THE PHOENIX AREA. THIS APPEARS TO BE ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE JET TRACKING ACROSS ARIZONA. NCEP HI-RES ARW AND NMM AS WELL AS SREF DEPICT VERY MODEST QPF THERE. THUS ADDED MENTION OF SLIGHT CHANCE TO HIGHER TERRAIN OF SOUTHERN GILA COUNTY FOR THE MORNING HOURS. COULDNT RULE OUT SPRINKLES IN THE FAR EAST VALLEY AND PORTIONS OF PINAL COUNTY BUT MEASURABLE PRECIP CHANCES TOO LOW TO MENTION. AS THE SHORT WAVE DEPARTS...POPS EAST OF PHOENIX DROP OFF THIS AFTERNOON BUT REDEVELOP OVER JOSHUA TREE NATIONAL PARK AS ANOTHER VORT MAX DROPS DOWN FROM NEVADA. LATEST RAP FORECAST SOUNDING FOR JTNP EVEN DEVELOP A LITTLE BIT OF CAPE...BUT NONE FOR BLYTHE. DESPITE THE ARRIVAL OF THIS WAVE...HEIGHTS ACTUALLY RISE SLIGHTLY AS THE MAIN PORTION OF THE SYSTEM BEGINS SHIFTING EAST. THE SHORT WAVE WILL BECOME A CLOSED LOW WITHIN THE TROUGH TONIGHT THEN TRACK SOUTHEASTWARD TO THE BORDERLANDS THURSDAY AND WEAKEN IN THE PROCESS. AS FOR TEMPERATURES ANOTHER REFRESHINGLY COOL DAY TODAY WITH VERY SIMILAR HIGH TEMPERATURES AS TUESDAY. THEN A WARMING TREND BEGINS THURSDAY. WINDS WILL BE LIGHT TODAY WITH SOME MINOR BREEZINESS THURSDAY. FRIDAY THROUGH TUESDAY... ON FRIDAY...THE RIDGE BEGINS TO MOVE IN AND THE WARMING TREND CONTINUES. HOWEVER...WITH NORTHERLY FLOW IN PLACE...A FINAL SHORT WAVE MAKES ITS WAY INTO ARIZONA FOR ONE LAST SLIGHT CHANCE OF MEAGER PRECIP FOR OUR EASTERNMOST HIGHER TERRAIN. OVER THE WEEKEND...THE RIDGE SLOWLY ADVANCES INLAND WITH TEMPERATURES REACHING THE UPPER 80S TO LOW 90S BY SUNDAY FOR THE LOWER DESERTS INCLUDING PHOENIX. MODELS GENERALLY AGREE ON THE RIDGE AXIS BEGINNING TO SHIFT EASTWARD ON MONDAY BUT THERE WILL STILL BE SOME ADDITIONAL WARMING WITH LOW 90S COMMON. ON TUESDAY...THE RIDGE LOOKS TO BE WEAKER DUE TO A NORTHERN BRANCH TROUGH MOVING INLAND AND A SOUTHERN BRANCH TROUGH NUDGING CLOSER TO SOUTHERN CALIFORNIA AND MEXICO. THE SOUTHERN BRANCH TROUGH HAVE MORE AFFECT ON US DUE TO CIRRUS SPREADING OVERHEAD. THUS TEMPS DIP DOWN A BIT ON TUESDAY BUT STILL WELL ABOVE NORMAL. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... ONLY MINIMAL AVIATION CONCERNS THROUGH WEDNESDAY AFTERNOON AS WIND SPEEDS DECREASE AND FEW-SCT CLOUDS PREVAIL. GREATEST UNCERTAINTY IS TIMING THE WIND SHIFT BACK TO AN E/SE DIRECTION LATE TONIGHT. MODEL OUTPUT HAS CONSISTENTLY SHOWN THIS WIND SHIFT...THOUGH CONFIDENCE IN TIMING IS ONLY MODEST. OTHERWISE...SCT DECK ARE LIKELY OVER HIGHER TERRAIN EAST OF PHOENIX ON WEDNESDAY...THOUGH MOUNTAIN OBSCURATION SHOULD NOT BE AS LARGE AS A PROBLEM AS TUESDAY. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... OCCASIONALLY GUSTY WINDS THIS EVENING WILL BE THE PRIMARY AVIATION CONCERN THROUGH WEDNESDAY WITH ONLY OCCASIONAL SCT CLOUD DECKS. WIND SPEEDS SHOULD GRADUALLY DECREASE OVERNIGHT LOSING STRONGER GUSTS...AND BECOME NOTICEABLY LIGHTER ON WEDNESDAY. THERE IS THE POSSIBILITY THAT DIRECTIONS COULD EVEN BECOME VARIABLE FOR PERIODS AS THE GRADIENT WEAKENS SUBSTANTIALLY. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... THURSDAY THROUGH MONDAY... A WEAKENING LOW PRESSURE SYSTEM WILL CONTINUE TO AFFECT THE REGION THURSDAY THROUGH FRIDAY...ALBEIT WITH GENERALLY DRY CONDITIONS AND PARTLY CLOUDY TO MOSTLY SUNNY SKIES. IT WILL BE BREEZY AT TIMES DURING THE AFTERNOON THURSDAY AND FRIDAY OVER SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA. COOLER HIGH TEMPERATURES WILL PERSIST THURSDAY WITH READINGS STAYING BELOW NORMAL UNTIL FRIDAY WHEN HIGHS WILL WARM INTO THE 80S OVER THE LOWER DESERTS. HUMIDITIES WILL LOWER GRADUALLY THURSDAY INTO FRIDAY AND SHOULD GENERALLY RANGE BETWEEN 10 AND 15 PERCENT. HIGH PRESSURE WILL GRADUALLY SETTLE BACK INTO THE REGION OVER THE WEEKEND AND INTO NEXT WEEK WITH WARMING TEMPERATURES AND CONTINUED RELATIVELY DRY CONDITIONS. BY MONDAY EXPECT WARMER DESERTS TO REACH INTO THE LOW 90S WITH MINIMUM HUMIDITIES TO FALL INTO THE SINGLE DIGITS ACROSS MUCH OF THE AREA. NO SIGNIFICANT WINDS ARE EXPECTED OVER THE WEEKEND JUST TYPICAL AFTERNOON LOCAL GUSTINESS FAVORING UPSLOPE OR THE SOUTHWEST. && .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...AJ AVIATION...MO FIRE WEATHER...CB/KUHLMAN/MEYERS
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
352 AM CDT WED MAR 30 2016 .SHORT TERM...(Today and Tonight) Issued at 351 AM CDT WED MAR 30 2016 An intense upper low across western UT and western AZ will shear apart with one section of the upper trough lifting northeast across CO into NE, which will amplify as it phases with a northern branch upper trough digging southeast across the northern plains. The upper trough will then move east across NE and KS Tonight. As the H5 trough lifts northeast across CO into western NE and KS an H5 jet max of 55 to 60 KTS will spread northeast across eastern KS during the afternoon and evening hours. The mesoscale models such as the ARW and NMM version of the WRF and the GFS show a round of elevated thunderstorms developing as the upper jet lifts northeast from the TX PNHDL into western and central KS this morning. If these models turn out to be accurate then precip chances will be higher across the CWA during the mid and late morning hours. These elevated storms may rotate due to the increasing vertical windshear,so I can not rule out some large hail. However, the NAM and RAP models do not show elevated storms developing through the morning hours. This afternoon and evening, the surface trough and dryline will be moving east from western KS across central KS into the western counties of the CWA. There are difference in the speed of the dryline eastward progress. Most numerical model solutions move the surface dryline along a Seneca, to Manhattan line by 6 PM this evening. Surface convergence ahead of the dryline combined with ascent ahead of the H5 trough will break the weak cap and cause scattered thunderstorms to develop across northeast and east central KS. Every model shows there will be good vertical windshear and MLCAPE of 1500 J/KG to 2500 J/KG. The NAM models seems a bit too high with forecasting around 3000 J/KG of MLCAPE across east central KS. Instability will depend on how much elevated convection develops this morning, if any, and if there will be any insolation for surface heating ahead of the dryline. I think there will be widely scattered elevated thunderstorms during the mid morning hours but these storms should move northeast into MO by noon, then we should see some breaks in the OVC for surface heating ahead of the dryline. Given an environment with good vertical windshear and sufficient instability, we should see developing thunderstorms late this afternoon become supercell thunderstorms. The models due vary quite a bit on how much low-level vertical windshear will develop ahead of the dryline. The WRF model solutions show surface and 850mb winds to veer across the warm sector late this afternoon and early this evening. 0-1 KM SRH values are only 50 to 100 J/kg. Meanwhile the NAM model solution and to some extent the RAP model have surface winds a bit more backed and 850mb winds are not as veered. The NAM develops about 100 to 200 j/kg of SRH, which would be more conducive for any supercell thunderstorms to produce tornadoes. Even if winds are a bit veered as the mesoscale models forecast, I cannot rule out a few weak tornadoes. If the low-level winds back more ahead of the dryline then the tornado threat will be greater and the tornadoes may be more intense. Any supercell thunderstorms will also produce large hail and damaging wind gusts. Most of the numerical models shift the threat for severe storms east of the CWA during the mid evening hours. The NAM model hangs up the dryline across the eastern counties of the CWA and storms continue to shift northeast across east central KS. I think over the mid evening hours the isolated supercells will evolve into line segment with the main hazards being damaging winds and perhaps some flash flooding if training of storms occur across the southeast counties of the CWA. The NAM model finally shifts the thunderstorms east of the CWA after midnight. .LONG TERM...(Thursday through Tuesday) Issued at 351 AM CDT WED MAR 30 2016 Early Thursday morning a shortwave on the base of the main upper level trough will be over northeast Kansas. There remains a small chance for rain near the Nebraska boarder Thursday morning with soundings showing decent saturation and forcing in the lower levels of the atmosphere. Most the afternoon Thursday should be dry across the area before another shortwave passes just north of the area and rain chances clip extreme northeast Kansas. From here, precipitation chances end for the rest of the period. Winds shift from the south overnight Saturday, leading to a warm and dry Sunday with highs in the middle to low 70s. Sunday afternoon these southerly winds will gust up to 25kts, creating possible elevated fire concerns for this day. The rest of the period stays mild with highs generally in the upper 60s or low 70s and lows in the 40s. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday Night) Issued at 1203 AM CDT WED MAR 30 2016 Little change to the existing TAF other than minor adjustments to the arrival timing of MVFR cigs. These cigs are currently in south central KS and should move over TAF sites by 09Z or so. Initially around 2500 feet, should fall closer to 1500 feet within 1-2 hours of arrival. Cigs will lift/scatter between 16z-19z with TS possible any time after 21Z and through the remainder of the TAF with limited confidence in exact timing. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Gargan LONG TERM...Heller AVIATION...Barjenbruch
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1206 AM CDT WED MAR 30 2016 ...Update to aviation forecast discussion... .UPDATE... Issued at 925 PM CDT TUE MAR 29 2016 Have been closely monitoring incoming model data this evening, and the 01Z RAP, 00Z NAM, and 00Z HRRRexp have been showing some interesting model trends. First off, the trend has been toward slightly higher dewpoints by early afternoon with low 60s dewpoints into eastern KS. Another trend has been for the dryline to be setting up a bit farther to the west. At 19Z, the HRRRexp has the dryline from Minneapolis to Washington while the RAP is along Highway 81 and the NAM another 20 miles west. All models indicate at least some modification/mixing of low level moisture immediately in advance of the approaching dryline with dewpoints in the upper 50s to around 60. Afternoon surface winds are showing a consistent trend to have a westerly component and be veered as the surface low passes through eastern Nebraska. However, some concern remains for localized backing of winds between 21Z and 03Z as a new surface low deepens in south central KS. These are early indications, but all point to a continued and increasing severe weather threat across eastern Kansas between about 4 PM and 10 PM (or possibly later if the dryline stalls). Supercells look to be the primary storm mode but if winds remain veered into the late afternoon and evening could see more of a straight line hodograph with storm splitting and interaction, possibly resulting in some upscale growth and mixed modes. The take-away right now, based again on very early indications, is that the severe potential certainly exists through late afternoon and the evening with large hail, damaging wind, and tornadoes all possible. If winds back ahead of the developing surface low in the evening and if dewpoints hold in the low 60s, then the tornado threat could increase markedly. && .SHORT TERM...(This Evening through Wednesday) Issued at 306 PM CDT TUE MAR 29 2016 Elongated upper low was centered over the Inter-mountain West with a secondary shortwave trough continuing to drop south out of Manitoba territory. At the sfc, strong pressure gradient across the state with the sfc low over southeast CO has contributed to gusty southeast winds this afternoon in the 15 to 25 mph sustained range. Lower dewpoint temps across far eastern and northeast Kansas in addition to highs reaching the 60s has resulted in very high fire danger conditions across east central and far northeast Kansas. For this evening, the winds will persist in strength as the sfc low deepens eastward with an upper vorticity maxima ejecting northeast towards the northern plains. Southerly winds sustain between 15 and 25 mph at the sfc with occasional gusts up to 35 mph as the low level jet increases. Initial wave of lift will bring scattered showers and thunderstorms to north central KS after midnight. Expect this activity to spread east over the CWA through the morning hours. This activity is not expected to be severe with the MU Cape values generally below 600 J/KG. In addition to the overcast skies, forecast soundings show much of the moisture in the lowest levels of the atmosphere coinciding with the best forcing, indicative of light drizzle during this time as well. How quickly this precip dissipates allowing skies to clear out is variable depending on the model, leading to some uncertainty to how the afternoon evolves. The WRF models and the GFS have been consistently faster to clear skies and the dry line towards the MO/KS border by late afternoon while the NAM, ECMWF, and SREF runs have been consistently slower, focusing the eastern half of the CWA in a more favorable area. These factors have lead to some uncertainty in fire danger conditions and severe convection developing in the late afternoon and evening hours. More details are mentioned in the next period. For highs on Wednesday, while depth of cloud cover and presence of precip is still uncertain, strong warm advection ahead of the dryline should help support temps reaching the lower 70s, possibly mid 70s over north central KS as the dryline passes. RH values therefore may quickly fall in north central areas to the lower 20 percent range in the late afternoon. Wind speeds at this time remain marginal at 15 to 20 mph with gusts around 25 mph so will not mention headlines at this point. However, very high fire danger is likely. Main concern this forecast period will be the threat for strong to severe thunderstorms Wednesday afternoon across portions of eastern KS. During the early afternoon a dry line will push eastward through the forecast area. This dry line will separate deep mixing from the deep low level moisture to the east. Soundings show that surface heating along with mid level cooling associated with the approaching trough will erode the cap in place. This will allow thunderstorms to form along the dry line during the late afternoon. If the surface heating remains limited due stratus east of the dry line then convective initiation may be difficult or delayed. The cape seems to vary between the models, but with a dew point in the upper 50s to near 60, and steep mid level lapse rates it should yield around 1000 to 1500 j/kg of MLcape if the stratus can manage to clear out. With the approaching mid level system deep layer shear will be on the order of 50 to 60 kts. The hodographs are mainly straight line with the exception of the NAM. The NAM shows some localized backed winds in the low levels and a strengthening low level jet, which causes 0-3 km SRH values to approach 400. In reality those values may be closer to 100 to 200. Storms if they develop will be moving at 50 mph to the northeast. All of these parameters will support supercell development with large hail and damaging wind as the main threats. Although given this environment some tornadoes will be possible as well. The 0-1 km and 0-3 km bulk shear values could support mesovortex circulations if cold pools were to congeal into any line segments. There is split model solutions on where the dry line will be when storms develop. The farthest west seems to be a line from Washington to Dickinson counties, while the farthest east would be Jefferson to Anderson counties. So quite some spread that leads to some uncertainty in this forecast. The earliest models develop convection appears to be around 4 pm, and given the storm motion should clear the forecast area by 7 pm. .LONG TERM...(Wednesday Night through Tuesday) Issued at 306 PM CDT TUE MAR 29 2016 Thursday morning the synoptic cold front slides through the forecast area. Frontogenesis should provide enough lift for scattered showers mainly across northern KS. Initially there may be some mid level dry air to overcome before precipitation can reach the ground. Another shortwave will track towards the area in the northwest flow, which should clip northeast KS Thursday morning. This wave will bring the chance for showers after the low levels become saturated. The pattern remains quiet heading into the extended as northwest flow aloft continues. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday Night) Issued at 1203 AM CDT WED MAR 30 2016 Little change to the existing TAF other than minor adjustments to the arrival timing of MVFR cigs. These cigs are currently in south central KS and should move over TAF sites by 09Z or so. Initially around 2500 feet, should fall closer to 1500 feet within 1-2 hours of arrival. Cigs will lift/scatter between 16z-19z with TS possible any time after 21Z and through the remainder of the TAF with limited confidence in exact timing. && .TOP Watches/Warnings/Advisories... NONE. && $$ UPDATE...Barjenbruch SHORT TERM...Bowen/Sanders LONG TERM...Sanders AVIATION...Barjenbruch
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
122 AM EDT WED MAR 30 2016 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 343 PM EDT TUE MAR 29 2016 12Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW AN UPR RDG BLDG INTO THE WRN GREAT LKS...WITH 00Z-12Z H5 HGT RISES UP TO 80M AT GRB AND APX...DOWNSTREAM OF POLAR BRANCH CLOSED LO OVER THE WRN CONUS. SFC HI PRES OVER LOWER MI AND VERY DRY LLVL AIR DEPICTED ON THE LOCAL 12Z RAOBS ARE RESULTING IN QUIET WX OVER THE CWA DESPITE INCRSG HI CLDS ASSOCIATED WITH WAA IN INCRSG SLY FLOW BTWN DEPARTING HI PRES TO THE SE AND FALLING MSLP IN THE WESTERN PLAINS AHEAD OF WRN TROF. DESPITE THE INCRSG HI CLD COVER...TEMPS HAVE RISEN WELL INTO THE 50S OVER PORTIONS OF THE W HALF...ESPECIALLY WHERE SLY FLOW IS DOWNSLOPING. SOME RA TO THE NE OF SFC WARM FNT IN THE CENTRAL PLAINS HAS MOVED AS FAR NE AS FAR SW MN THIS AFTN. MAIN FCST CONCERNS IN THE SHORT TERM ARE CLD TRENDS AND TIMING ARRIVAL OF RA AHEAD OF PLAINS SFC LO PRES/WARM FNT FCST TO APRCH FM THE SW. TNGT...ALTHOUGH THE EVNG WL BE PCPN FREE WITH LINGERING DRY LLVL AIR...INCRSG DEEP LYR QVECTOR CNVGC RELATED TO SHARPENING ISENTROPIC ASCENT/MSTR ADVECTION BEST SHOWN ON THE 290 AND 295K SFCS /ABOUT H8- 7/ AND UPR DVGC IN RRQ OF 120KT H3 JET MAX FCST NEAR JAMES BAY AT 12Z WED WL RESULT IN INCRSG POPS OVERNGT...ESPECIALLY OVER THE NW HALF OF THE CWA. MORE PERSISTENT LLVL DRY AIR OVER THE SE HALF CLOSER TO DEPARTING SFC HI PRES IN THE MID ATLANTIC STATES WL HOLD DOWN POPS IN THAT AREA. WITH THE THICKENING CLDS AND STEADY SSW WINDS...THE OVERNGT WL BE MUCH WARMER THAN EARLY THIS MRNG. WITH SFC TEMPS FCST TO HOLD WELL ABOVE 32...THERE WL BE NO FROZEN/FRZG PCPN. WED...PERIODS OF RA UNDER AXIS OF DEEPER MSTR ASSOCIATED WITH PERSISTENT DEEP LYR QVECTOR CNVGC/290-295K ISENSTROPIC ASCENT WL BE THE RULE. A SFC COLD FNT ASSOCIATED WITH A DIGGING SHRTWV IN THE NRN BRANCH FLOW IS FCST TO REACH THE NW CWA BY LATE IN THE DAY. SOME OF THE GUIDANCE...ESPECIALLY THE 12Z NAM AND 00Z ECWMF...SUGGESTS SOME MID LVL DRYING ASSOCIATED WITH THIS NRN BRANCH FLOW MAY RESULT IN DIMINISHING POPS OVER AT LEAST THE FAR NW LATE IN THE DAY. SO FCST WL RETAIN SOME LOWERING OF POPS IN THAT AREA TOWARD 00Z THU. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 433 PM EDT TUE MAR 29 2016 FOR THE NEXT 1 TO 2 WEEKS...SOME DEGREE OF RIDGING WILL LIKELY PERSIST OVER WRN N AMERICA...THOUGH THE MORE PERSISTENT POSITIVE ANOMALY CENTER SHOULD REMAIN IN WRN CANADA. PER GFS ENSEMBLES...THE RIDGE WILL REACH PEAK AMPLITUDE WED/THU WHEN 500MB HEIGHT ANOMALIES TOP OUT AT 3-3.5 STANDARD DEVIATIONS ABOVE CLIMATOLOGY IN NRN BRITISH COLUMBIA/ADJACENT YUKON. THIS WILL FORCE DEEP TROFFING INTO SE CANADA AND ADJACENT GREAT LAKES. MAX NEGATIVE HEIGHT ANOMALIES OF 3-3.5 STANDARD DEVIATIONS BLO CLIMATOLOGY WILL BE CENTERED OVER ONTARIO SAT. WHILE CORE OF A COLD ARCTIC AIR MASS FOR EARLY APR WILL PASS BY TO THE NE...850MB TEMPS FALLING TO 2.5 STANDARD DEVIATIONS BLO CLIMATOLOGY HERE INDICATE CONDITIONS WILL BE QUITE COLD FOR EARLY APR STANDARDS THIS WEEKEND. MODERATION WILL BE A LITTLE SLOWER THAN PREVIOUSLY EXPECTED EARLY NEXT WEEK AS ANOTHER SHORTWAVE HELPS TO MAINTAIN ERN TROFFING. THEREAFTER...EXPECT MODERATION BACK TOWARD MORE TYPICAL EARLY APR TEMPS DUE TO WEAKER WRN RIDGING. HOWEVER... TEMPS COULD FLUCTUATE QUITE A BIT THRU THE FOLLOWING WEEKEND AS MODELS SUGGEST WRN RIDGE MAY AMPLIFY AT TIMES...ALLOWING LINGERING COLD AIR IN CANADA TO DUMP S BRIEFLY BEHIND PASSING SHORTWAVES. AS FOR PCPN...EARLY IN THE FCST PERIOD...PCPN WILL REVOLVE AROUND EVOLUTION OF THE ENERGY CURRENTLY OVER THE SW CONUS. A SIGNIFICANT PIECE OF ENERGY WILL EJECT DOWNSTREAM INTO THE GREAT LAKES WHILE ADDITIONAL ENERGY DIVES S IN THE AMPLIFYING NRN STREAM. THIS WILL LEAD TO THE MAIN PCPN EVENT OF THIS FCST CYCLE...OCCURRING WED/THU. SHORTWAVE PASSING FRI WILL PRODUCE DIURNALLY ENHANCED SHSN. CLIPPER SYSTEM PASSING EARLY SAT WILL THEN HERALD THE ARRIVAL OF MUCH COLDER AIR FOR THE WEEKEND...ACCOMPANIED BY LATE SEASON LES AND DIURNALLY ENHANCED SHSN. AFTER THE WEEKEND...THERE IS GREATER THAN NORMAL UNCERTAINTY IN PROGRESSION OF SHORTWAVES AND POTENTIAL PCPN. CANADIAN ENSEMBLES AND RECENT GFS/ECMWF RUNS SUGGEST THE NEXT BEST POTENTIAL FOR PCPN WOULD OCCUR AROUND WED. BEGINNING WED NIGHT/THU...AS ENERGY LIFTS OUT ACROSS THE PLAINS INTO THE GREAT LAKES WED NIGHT/THU...DEGREE OF PHASING WITH NRN STREAM ENERGY DIVING S INTO THE PLAINS WILL DETERMINE TRACK/STRENGTH OF THE SFC LOW PRES TRACKING FROM THE CNTRL PLAINS INTO THE GREAT LAKES. PHASING IS FURTHER COMPLICATED BY ANOTHER SHORTWAVE DIVING SSE THRU MANITOBA. BASED ON YESTERDAYS AND TODAY GUIDANCE...IT LOOKS INCREASINGLY LESS LIKELY THAT A WELL DEVELOPED/WRAPPED UP WINTER STORM WITH A WELL-DEFINED DEFORMATION BAND OF HVY PCPN WILL EVOLVE FROM THIS COMPLEX OF SHORTWAVES...BUT THAT`S NOT TO SAY THAT SOME MDT TO PERHAPS LOCALLY HVY SNOW ACCUMULATIONS WON`T OCCUR SOMEWHERE OVER THE UPPER MISSISSIPPI VALLEY AND THE UPPER LAKES. MODEL GUIDANCE CONTINUES TO NARROW IN ON A SFC LOW TRACK FROM THE WRN PLAINS ENE ACROSS WI AND THRU THE STRAITS AREA...AND ALL AVBL 12Z MODELS NOW SHOW QUITE GOOD AGREEMENT ON PROGRESSION OF COLDER AIR INTO UPPER MI WED NIGHT/THU WITH THE EXCEPTION OF THE NAM WHICH IS CONSISTENTLY FARTHEST S WITH COLDER AIR AND CHANGE TO SNOW AT EACH TIME STEP LATE WED NIGHT THRU THU. IN EXCLUDING THE NAM...EXPECT RAIN TO MIX GRADUALLY WITH/CHANGE TO SNOW FROM NW TO SE WED NIGHT/THU...BEGINNING NW LATE WED EVENING AND NOT REACHING THE SE UNTIL MID TO LATE AFTN THU. WITH THE LACK OF A WELL DEVELOPED SYSTEM/DEFORMATION PCPN...HEAVIER PCPN WILL NOT EXTEND TOO FAR NW INTO THE COLDER AIR. THIS SHOULD RESULT IN A FAIRLY NARROW BAND OF MAX SNOW ACCUMULATION IN THE ADVY RANGE SOMEWHERE OVER THE NW HALF OF UPPER MI. PER 00Z AND 12Z MODEL GUIDANCE...IT APPEARS THE AREA ROUGHLY FROM WATERSMEET/IRON RIVER NE THRU MICHIGAMME/NEGAUNEE SHOULD BE THE APPROXIMATE ZONE OF HEAVIEST SNOWFALL. WITH VERY LITTLE CHANCE OF WARNING CRITERIA BEING REACHED...ESPECIALLY WITH THE HEAVIER SNOW LIKELY FALLING DURING THE DAY THU WHEN WEAK SOLAR INSOLATION WILL AID MELTING...WATCH HEADLINES ARE NOT WARRANTED. MAIN SYNOPTIC PCPN SHIELD WILL DEPART LATER THU/THU EVENING. AFOREMENTIONED SHORTWAVE IN MANITOBA WILL THEN SWING THRU NRN ONTARIO/UPPER LAKES ON FRI...PROVIDING SCT TO NMRS -SHSN THAT WILL LIKELY BE ENHANCED BY DIURNAL HEATING UNDER CHILLY 500MB TEMPS DROPPING INTO THE MID -30S C. STRONGER SHORTWAVE AND ARCTIC COLD FRONT PASS ACROSS THE AREA SAT MORNING...ACCOMPANIED BY SHSN. WITH 850MB TEMPS FALLING TO -14 TO -17C SAT...LOOKS LIKE A SPRING-TIME HYBRID TYPE OF LAKE EFFECT SCENARIO SETTING UP BEHIND SHORTWAVE AS DAYTIME HEATING DISRUPTS LES PROCESSES AND LEADS TO SCT-NMRS DIURNALLY DRIVEN VIGOROUS SHSN ACROSS THE ENTIRE AREA UNDER CYCLONIC FLOW AND COLD AIR ALOFT. -SHSN WOULD THEN TRANSITION BACK TO A MORE TYPICAL LES REGIME SAT NIGHT/SUN MORNING AS 850MB TEMPS FALL TOWARD -20C. WITH MODERATING TEMPS ALOFT AND LOSS OF CYCLONIC FLOW...MAY NOT SEE MUCH DIURNALLY DRIVEN SHSN ACTIVITY ON SUN AFTER LES PROCESSES GET DISRUPTED AGAIN BY DAYTIME HEATING. HEADING INTO MON/TUE...THE LAST DAY OR SO OF MEDIUM RANGE MODEL RUNS HAVE SUGGESTED A SHORTWAVE TRACKING SE INTO THE RETREATING ERN TROF. ASSOCIATED WAA/ISENTROPIC ASCENT WITH WEAK SFC WAVE TRACKING ALONG THE EDGE OF THE LATE SEASON ARCTIC AIR WOULD GENERATE A STREAK OF SN SOMEWHERE ACROSS THE UPPER MISSISSIPPI VALLEY AND GREAT LAKES REGION SUN NIGHT/MON. UTILIZED A CONSENSUS OF RECENT MODEL RUNS FOR POPS (MOSTLY SCHC) DUE TO THE LACK OF MODEL AGREEMENT AND LACK OF RUN-TO- RUN CONTINUITY. SHOULD SEE A DRY DAY ON TUE BEFORE A POTENTIAL MIXED PCPN EVENT WED. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 122 AM EDT WED MAR 30 2016 VFR CONDITIONS WILL CONTINUE INTO WED MORNING AT ALL SITES. GUSTY S WINDS UNDER THE TIGHTENING PRES GRADIENT BTWN THE DEPARTING HI PRES AND DVLPG LO PRES IN THE PLAINS WL GIVE WAY TO SOME LLWS OVERNIGHT WITH INCRSG NEAR SFC STABILITY AT KSAW. AS THE SSW FLOW TAPS MOISTER AIR WED MRNG...EXPECT SOME -RA TO ARRIVE AND CIGS TO LOWER INTO MVFR IN THE MORNING...BEGINNING FIRST AT KIWD AND LAST AT KSAW. BY AFTERNOON...KIWD AND KCMX WILL BE LIFR AND KSAW WILL BE MVFR UNTIL LATE AFTERNOON. ALL SITES WILL STAY LIFR IN THE EVENING WITH LIGHT RAIN. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 343 PM EDT TUE MAR 29 2016 AS THE PRES GRADIENT TIGHTENS OVER THE UPPER LAKES TONIGHT BETWEEN DEPARTING HI PRES AND LO PRES DEVELOPING IN THE WESTERN PLAINS... EXPECT SSW WINDS UP TO 25 KTS INTO WED MORNING. ALTHOUGH THE WINDS WILL DIMINISH AS THEY SHIFT TO THE NNW FOLLOWING A COLD FRONTAL PASSAGE LATE WED AFTERNOON/EVENING...STRONGER NNE WINDS UP TO 30 KTS WILL BE THE RULE LATE WED NIGHT AND THU AS A LO PRES RIDES NE ALONG THE STALLED FRONT JUST TO THE S OF UPPER MI. NOT OUT OF THE QUESTION THERE COULD BE SOME GALES ESPECIALLY OVER THE E HALF ON THU. WINDS WILL DIMINISH AND SHIFT TO THE WNW FOLLOWING THE EXIT OF THIS LO TO THE NE AND THE ARRIVAL OF A WEAK HI PRES RIDGE ON FRI. EXPECT ANOTHER LO TO TRACK THRU THE UPPER LAKES ON FRI NIGHT...WITH A WIND SHIFT TO THE N LATE AT NIGHT AND SAT. WINDS COULD REACH AS HI AS 30 TO 35 KTS BEFORE DIMINISHING ON SUN WITH THE CLOSER APPROACH OF TRAILING HI PRES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...ROLFSON AVIATION...07 MARINE...KC Area Forecast Discussion National Weather Service Saint Louis MO 354 AM CDT WED MAR 30 2016 .SHORT TERM... (Through Late This Afternoon) Issued at 351 AM CDT Wed Mar 30 2016 Each new model run is a bit slower with system that is approaching region. However, decent moisture convergence as low level jet ramps up this morning. So will see scattered showers and storms develop ahead of system, especially over southeastern MO late this morning. Then coverage will be on the increase this afternoon as instability increases and mid level lapse rates steepen ahead of trof. A few of the storms could be severe and will be capable of producing large hail and damaging winds. High temps will depend on precipitation and cloud cover, but with gusty south winds, will see highs in the mid 60s to low 70s. Byrd .LONG TERM... (Tonight through Tuesday) Issued at 351 AM CDT Wed Mar 30 2016 Could see a bit of a break in the activity early this evening, then line of storms develop ahead of main frontal boundary, tracking east into western portions of forecast area between 03z and 06z. This activity may weaken a bit as it tracks across forecast as it outraces the front. Some strong to severe storms are possible with this round. Then main frontal passage will be between 12z and 20z Thursday. Redevelopment of storms will depend on how much the atmosphere may be able to recover, at this point feel that any storms that do develop will be over southeast MO and southern IL. Highs on Thursday will range from around 60 degrees far north to the low 70s over east central/southeastern MO and southwestern IL. Thursday night and Friday will see another batch of showers slide southeast through region on backside of system, mainly affecting the areas along and north of Interstate 70. Colder air to move in with highs only in the low 50s far north to around 60 far south on Friday. Beyond that, a decent cold front to slide south through region on Saturday, but it will be a dry passage. Will just see an increase in winds, with winds picking up from the northwest on back side of front, gusting to near 35 mph at times Saturday afternoon. Otherwise, dry and near normal temperatures through the rest of the forecast period. Extended models do bring another cold front through region on Monday, but activity to stay just to the northeast of forecast area at this time. Byrd && .AVIATION... (For the 06z TAFs through 06z Wednesday Night) Issued at 1145 PM CDT Tue Mar 29 2016 Still looking for LLWS to develop overnight as a southerly low level jet ramps up, with VFR flight conditions persisting. Showers and thunderstorms are expected to develop on Wednesday morning and increase in coverage through the afternoon in response to lift via the LLJ, and have a mention of SHRA/TSRA along with flight conditions lowering into the MVFR category. The highest probability of both showers and thunderstorms appears to be focused across the southeast third of MO into southern IL including the St. Louis area terminals. There may be a lull in precipitation on Wednesday evening and this is reflected with nothing mentioned in the TAFS. The probability of showers and thunderstorms will then increase after 06z Thursday. Specifics for KSTL: VFR flight conditions will persist overnight through mid morning on Wednesday. A southerly low level jet is still on schedule to ramp-up overnight resulting in a window of LLWS conditions from 09-15z. Showers and thunderstorms are expected to develop on Wednesday morning and increase in coverage through the afternoon in response to lift via the LLJ, and have a mention of SHRA/TSRA along with flight conditions lowering into the MVFR category. The TAF has the brunt of the adverse weather starting at 18z, however would not be surprised if it actually began slightly earlier. There may be a lull in precipitation on Wednesday evening and this is reflected with nothing mentioned in the TAF. The probability of showers and thunderstorms will then increase again between 08-12z Thursday. Glass && .PRELIMINARY POINT TEMPS/POPS... Saint Louis 69 60 71 42 / 90 80 20 20 Quincy 68 55 63 38 / 80 80 20 30 Columbia 71 56 65 40 / 50 80 10 10 Jefferson City 72 57 67 40 / 60 70 10 10 Salem 68 60 72 43 / 90 90 60 10 Farmington 66 59 72 41 / 90 90 60 10 && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
  [top] Area Forecast Discussion National Weather Service Springfield MO 348 AM CDT WED MAR 30 2016 .SHORT TERM...(Today and tonight) Issued at 245 AM CDT Wed Mar 30 2016 The main concern for this time frame remains unchanged: Severe weather potential. Strong low pressure will shift east across Neb with a trailing dryline reaching the Flint Hills region of KS by early evening 7pm/31-00z. The main concern will be how much convection will be able to fire along the dryline late today and this evening while moderate instability is in place. Some modest moisture return at around 850mb is evident in sfc observations and is in line with RAP progged soundings in the near term. Moisture is advecting n-ne underneath and elevated mixed layer/cap along with more extensive mid/upper level moisture. Will still take some work to get precip going with sfc dew points still in the low/mid 30s. Subtle mid level impulses moving northeast from the southern Plains will increase overall lift while deeper low level moisture rapidly increases for the southwest this morning increasing chances for elevated convection with mucapes reaching up to near 1500 j/kg. Can`t rule out some hail with stronger updrafts given good mid level lapse rates. There will be a break, or at least a partial one, in the overall coverage of showers during the mid afternoon. Attention then turns to the dryline off to our west. A narrow corridor of moderate surface based instability is expected to develop with uncapped mlcape values of about 1500 j/kg by early evening (progged GFS KJLN sounding). The temporal window for progged robust instability (GFS) looks small late today and this evening but given the strong vertical shear a large hail and tornado threat exists where discreet convection can develop. The high res ARW and NMM are not too bullish in moving the convection too far off the dryline initially so it looks like the best chance for severe storms late today and this evening will be over the western cwfa. As the low continues off to the east, a cold front catches up to the dryline and moves east through the cwfa overnight. Again, high res models are not to bullish with convection as the front sweeps through with more robust convection to our south limited moisture/buoyancy over our area (as mentioned in SPC discussion). Will need to watch trends closely as the weather evolves today. The SPC day 1 looks good with a slightly higher probability of tornadoes over the far western cwfa and a general 15% hail and wind risk over most of the area. The hail risk will likely be more tied to earlier elevated convection and then what every develops near the dryline. The wind risk will be more late today and tonight. .LONG TERM...(Thursday through Tuesday) Issued at 245 AM CDT Wed Mar 30 2016 A colder and dry air mass moves into the area behind the front Thu. Frost headlines may be needed with the coldest night/early morning looking to be Fri/Sat morning. A couple of shortwaves moving through the upper level nw flow may produce some clouds brief sprinkles over the northeast cwfa Fri. A quick warming trend will occur this weekend. Another front is expected to move south into/through the area Monday, but with dry air expected to be in place, only modest rain chances are expected at best. Cooler and dry weather is expected for day 7/Tue. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1216 AM CDT Wed Mar 30 2016 An approaching storm system will bring a variety of potential hazards to the region through Wednesday evening. Low level wind shear conditions will persist into Wednesday morning and may develop again Wednesday evening. Brisk and gusty southeast to south surface winds will continue for much of the period. A band of showers and thunderstorms will bring a period of MVFR conditions to the area Wednesday morning. Additional storms will then be possible late Wednesday evening around the Joplin aerodrome. && .SGF Watches/Warnings/Advisories... MO...NONE. KS...NONE. && $$ SHORT TERM...DSA LONG TERM...DSA AVIATION...Schaumann
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1139 PM CDT TUE MAR 29 2016 .SYNOPSIS... ISSUED AT 322 PM CDT TUE MAR 29 2016 H5 ANALYSIS THIS MORNING HAS A CLOSED LOW ALONG THE UTAH AND NEVADA BORDER. 100 METER HT FALLS WERE NOTED ACROSS SRN CALIFORNIA INTO NRN AZ AND A 90 KT H5 JET STREAK EXTENDED FROM SAN DIEGO...TO FLAGSTAFF AZ. UPSTREAM OF THE LOW...RIDGING WAS PRESENT FROM THE OZARKS NWD INTO NRN MINNESOTA...WHILE A TROUGH OF LOW PRESSURE WAS PRESENT OVER THE CANADIAN MARITIMES AND NEW ENGLAND. CLOSER TO WESTERN AND NORTH CENTRAL NEBRASKA...A WEAK SHORTWAVE WAS NOTED OVER SWRN NEBRASKA. THIS ALONG WITH SOME ELEVATED WARM AIR ADVECTION...LED TO THUNDERSTORMS EARLIER THIS MORNING ACROSS THE SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA. THIS ACTIVITY HAS SINCE PUSHED EAST OF THE AREA. IN ITS WAKE...ABUNDANT HIGH LEVEL CLOUDS CONTINUE TO STREAM INTO THE AREA FROM THE SOUTHWEST. AT THE SURFACE...LOW PRESSURE WAS PRESENT OVER EASTERN COLORADO WITH AN INVERTED SURFACE TROUGH EXTENDING NWD INTO THE CENTRAL PANHANDLE OF NEBRASKA. EAST OF THIS LOW AND INVERTED SURFACE TROUGH...WINDS WERE FROM THE SOUTH OR SOUTHEAST ACROSS WESTERN AND NORTH CENTRAL NEBRASKA THIS AFTERNOON AND GUSTY. LOW LEVEL MOISTURE CONTINUES TO STREAM INTO SOUTHWESTERN NEBRASKA THIS AFTERNOON AS DEW POINTS ARE NOW IN THE LOWER 40S ACROSS SWRN NEBRASKA. TEMPERATURES AS OF 3 PM CDT RANGED FROM 54 AT ONEILL TO 65 AT NORTH PLATTE AND IMPERIAL. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 322 PM CDT TUE MAR 29 2016 TONIGHT AND WEDNESDAY...IN THE TONIGHT PERIOD...THE MAIN CHALLENGE IS PRECIPITATION AND THUNDERSTORM CHANCES FOR MAINLY WESTERN PORTIONS OF THE FORECAST AREA. LATER THIS AFTERNOON THROUGH EARLY EVENING...THE LATEST NAM12...GFS AND HRRR SOLNS INITIATE CONVECTION ALONG THE NEBR/CO BORDER AROUND 23Z THIS EVENING...LIFTING THIS NORTH NORTHEAST INTO THE WESTERN SANDHILLS AND NWRN NEBRASKA THIS EVENING. GOOD DEEP LAYER SHEAR IS NOTED TONIGHT WITH 40 TO 60 KTS NOTED. HOWEVER MEAGER CAPES OF 500 TO 1000 J/KG EXIST...SO THE SEVERE THREAT SHOULD BE FAIRLY MARGINAL THIS EVENING. HOWEVER CANNOT RULE OUT A STRONG STORM OR TWO GIVEN THE STRONG APPROACHING LOW AND DYNAMICS ALOFT. WILL CONTINUE TO MENTION A STRONG TS THREAT GENERALLY WEST OF A NORTH PLATTE TO VALENTINE LINE. OVERNIGHT...MORE WIDESPREAD PCPN WILL DEVELOP OVER NORTHERN AND NORTHWESTERN PORTIONS OF THE FORECAST AREA. THIS IS IN THE VICINITY OF A H7 FRONT WHICH IS ANCHORED ALONG THE SD/NEBR BORDER. ELEVATED INSTABILITY CONTINUES OVERNIGHT AS WELL ACROSS THE ENTIRE FORECAST AREA AS H800 LI/S REMAIN NEGATIVE ACROSS THE NRN 2/3RDS OF THE FORECAST AREA. WITH THIS IN MIND...I KEPT IN A MENTION OF THUNDER FROM THE INHERITED FCST. SHIFTING INTO WEDNESDAY...RAIN WILL CONTINUE ACROSS NORTHERN NEBRASKA DURING THE EARLY MORNING HOURS. AS THE H5 LOW TRACKS OUT OF THE PANHANDLE INTO WEST CENTRAL NEBRASKA WEDS AM...AIR WILL COOL DOWN ENOUGH TO SUPPORT SNOW IN THE NORTHWESTERN CWA DURING THE LATE MORNING HOURS. A NICE AREA OF DEFORMATION PRECIPITATION WILL DEVELOP WEDS ON THE NORTHERN PERIPHERY OF THE LOW AS IT TRACKS FROM WESTERN NEBRASKA INTO EASTERN NEBRASKA. AS THIS FEATURE TRACKS EAST..IT OPENS UP AS IT INCREASES ITS FORWARD SPEED ACROSS CENTRAL AND EASTERN NEBRASKA. THIS WILL MAKE FOR A FAIRLY TIGHT WINDOW FOR CONDS FAVORABLE FOR SNOW. THIS WINDOW HAS BECOME SMALLER WITH THIS MORNINGS MODEL RUNS AS H85 TEMPS ARE NOW RUNNING 1-2C WARMER COMPARED TO YESTERDAY/S RUNS. THAT BEING SAID...WITH THE CURRENT TEMPERATURE PROFILE IN THE NORTHWEST...WE ARE LOOKING AT A 3-6 HR WINDOW WHICH IS FAVORABLE FOR SNOW. ATTM THAT IS APPROXIMATELY FROM 15 TO 21Z WEDS. WITH THIS IN MIND...CUT BACK SNOW ACCUMS IN THE NORTHWEST AND NOW HAVE 3 TO 5 INCHES IN SHERIDAN AND NORTHWESTERN CHERRY COUNTIES. WILL HOIST A WINTER WEATHER ADVISORY FOR WEDS AND CANCEL THE WINTER STORM WATCH WITH THE AFTERNOON PACKAGE. FURTHER EAST...THE THREAT FOR SEVERE STORMS IS STILL EXPECTED TO BE EAST OF THE FORECAST AREA WEDS AFTN AND EVE AS THE MODELS CONTINUE TO FORCE THE DRYLINE THROUGH THE FORECAST AREA WEDS AM. THE ONLY AREA OF CONCERN FOR A STRONG STORM MAY LIE IN THE FAR NERN CWA WHICH MAY END UP INVOF OF A WARM FRONT WEDS AFTN. THIS IS MORE FAVORED WITH THE GFS SOLN AS THE NAM12 HAS THIS FRONT SE OF THE AREA BY 21Z. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 322 PM CDT TUE MAR 29 2016 00Z THURSDAY AND BEYOND. THE UPPER LEVEL TROUGH WILL CONTINUE TO SWING THROUGH THE CWA LATE WEDNESDAY AFTERNOON...WITH THE TROUGH AXIS EAST OF THE FORECAST AREA BY 06Z THURSDAY. Q-VECTOR DIVERGENCE AND RESULTANT FRONTOLYSIS WILL BE UNDERWAY SHORTLY AFTER 00Z...WITH MOST LOCATIONS SEEING A MARKED DECREASE IN INTENSITY WELL BEFORE 06Z. THE DECREASE IN QPF HOWEVER WILL BE SHORT-LIVED AS THE NEXT SHORTWAVE AND ULJ DIVE SOUTH FROM WEST CENTRAL CANADA. THE TROPOSPHERE IS SHOWN TO BE SUFFICIENTLY SATURATED FOR AN ADDITIONAL ROUND OF QPF BEGINNING LATE MORNING ON THURSDAY. THE HEAVIEST QPF IS SHOWN ACROSS NORTHEASTERN AND NORTH CENTRAL PORTIONS OF THE FORECAST AREA WHERE OMEGA IS MAXIMIZED DURING THE EARLY AFTERNOON THURSDAY. TEMPERATURES SUPPORT RAIN OVER SNOW...BUT WILL CONTINUE A RAIN/SNOW MIX BEFORE 18Z AND AFTER 00Z AS TEMPERATURES WILL COOL WITH THE DIURNAL TREND. ANY ACCUMULATIONS OF SNOW WILL BE LIGHT. DUE TO RAPID COOLING ALOFT WITH THE SYSTEM...WEAK ELEVATED INSTABILITY IS SHOWN IN THE VARIOUS SOLUTIONS...THUS SHOWERS ARE PREFERRED...BUT A RUMBLE OR TWO OF THUNDER CANNOT BE RULED OUT. THE CLIPPER LIKE SYSTEM RAPIDLY ADVANCES EAST THURSDAY NIGHT INTO FRIDAY WITH QPF ENDING FROM NORTHWEST TO SOUTHEAST. BEYOND EARLY FRIDAY MORNING THE FORECAST TURNS DRY WITH A STARK WARMING TREND. THIS IS DUE TO THE DEVELOPMENT OF AMPLIFIED RIDGE OVER THE WESTERN STATES. THE RIDGE WILL EVENTUALLY BREAK DOWN AT DAY 7 OR BEYOND...THE BREAKDOWN WILL NEED TO BE MONITORED FOR POTENTIAL FIRE WX CONCERNS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1138 PM CDT TUE MAR 29 2016 A SFC LOW PRESSURE SYSTEM ACROSS COLORADO THIS EVENING TRACKS EAST WEDNESDAY. THE NAM WAS PREFERRED AS IT FARTHEST SOUTH. THIS WOULD INCREASE THE RISK OF MVFR CIGS OVERNIGHT THROUGH WEDNESDAY EVENING AND IT APPEARS TO BE VERIFYING THUS FAR. THUNDERSTORMS MAY CONTINUE OVERNIGHT AND WEDNESDAY...GENERALLY PROGESSING EAST ACROSS THE FCST AREA. RAIN CHANGES TO SNOW IN IFR/LIFR ACROSS NORTHWEST NEBRASKA. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 7 AM CDT /6 AM MDT/ TO 7 PM CDT /6 PM MDT/ WEDNESDAY FOR NEZ004-094. && $$ SYNOPSIS...BUTTLER SHORT TERM...BUTTLER LONG TERM...JACOBS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1237 AM CDT WED MAR 30 2016 .UPDATE... ISSUED AT 1217 AM CDT WED MAR 30 2016 RAIN CONTINUES TO SLOWLY SHIFT TOWARDS THE SOUTHEAST ACROSS THE AREA. LATEST HRRR HAS A GOOD HANDLE ON THE POSITION OF THE RAIN SO HAVE USED THAT FOR LATEST UPDATE. REMAINDER OF FORECAST REMAINS IN GOOD SHAPE. UPDATE ISSUED AT 909 PM CDT TUE MAR 29 2016 OVERALL LITTLE CHANGE TO THE ONGOING FORECAST OTHER THAN TO BLEND TO OBSERVED TRENDS AND THE 00-01 UTC HIGH RESOLUTION SUITES THROUGH THE NIGHT WHICH HAVE A GOOD HANDLE ON THE RAIN BAND ACROSS SOUTHERN NORTH DAKOTA IN ASSOCIATION WITH A QUASI- STATIONARY FRONT. UPDATE ISSUED AT 540 PM CDT TUE MAR 29 2016 INCREASED POPS ACROSS GRANT...MORTON AND OLIVER COUNTIES THIS EVENING PER RADAR TRENDS OF AN AREA OF RAIN SHOWERS THAT HAVE NOT BEEN WELL RESOLVED BY THE 18-21 UTC HIGH RESOLUTION SUITES. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 325 PM CDT TUE MAR 29 2016 MAIN FORECAST HIGHLIGHT IN THE SHORT TERM PERIOD WILL BE INCREASING CHANCES FOR PRECIPITATION IN THE FORM OF RAIN ACROSS SOUTHERN NORTH DAKOTA INTO THIS EVENING. CURRENTLY...LARGE UPPER LEVEL LOW SPINNING OVER THE INTERMOUNTAIN WEST REGION OF NEVADA/UTAH...WITH ASSOCIATED SURFACE LOW PRESSURE DEEPENING OVER THE LEE OF THE ROCKIES OVER EASTERN COLORADO. LEAD S/WV IMPULSES ORIGINATING FROM THE LOW EJECTING NORTH-NORTHEAST THROUGH THE NORTHERN PLAINS REGION GENERATING AREAS OF LIGHT PRECIPITATION. LATEST REGIONAL RADAR SHOWS ECHOS ACROSS NORTHERN NORTH DAKOTA UNDERNEATH AN UPPER LEVEL DEFORMATION ZONE...AND ANOTHER LINE OF LIGHT TO MODERATE RETURNS MOVING NORTH OVER NORTHERN SOUTH DAKOTA ASSOCIATED WITH A SFC WARM FRONT. A NORTHERN STREAM TROUGH WILL PUSH THE UPPER LOW OVER THE INTERMOUNTAIN WEST EAST INTO THE CENTRAL PLAINS TONIGHT INTO WEDNESDAY. WARM FRONT LIFTING NORTH ACROSS THE DAKOTAS STALLS TONIGHT BEFORE MOVING INTO THE UPPER MISSISSIPPI VALLEY REGION WEDNESDAY AFTERNOON. AS THE WARM FRONT STALLS TONIGHT...BAND OF PRECIPITATION NOW LIFTING ACROSS NORTHERN SOUTH DAKOTA WILL DEVELOP AND EXPAND ACROSS MUCH OF SOUTHERN NORTH DAKOTA AFTER 00Z...THEN DISSIPATES FROM NORTH TO SOUTH OVERNIGHT TONIGHT INTO WED AS DRY AIR MOVES IN FROM THE NORTH. A QUARTER TO HALF AN INCH OF RAINFALL STILL POSSIBLE OVER THE SOUTHERN JAMES RIVER VALLEY...WITH AMOUNTS DECREASING NORTH AND WEST OF THAT AREA. NEXT ITEM OF INTEREST IS AN EMBEDDED NORTHERN STREAM S/WV MOVING SOUTH-SOUTHEAST ACROSS SASKATCHEWAN AND INTO THE NORTHERN PLAINS WEDNESDAY AFTERNOON THROUGH WED NIGHT. INITIALLY RAIN IS FORECAST...WITH PRECIPITATION TRANSITIONING TO A MIX THEN ALL SNOW WEDNESDAY NIGHT INTO EARLY THUR AS COLDER AIR IS ADVECTED INTO THE REGION. 1-2 INCHES REMAINS POSSIBLE ACROSS WESTERN AND CENTRAL AREAS OF NORTH DAKOTA. GIVEN THE TIMING OF THE SNOW AND BUFKIT INDICATING A PERIOD OF HEAVY WET SNOW WITH SUPERSATURATION AND OMEGA PEAKED IN THE DENDRITIC GROWTH ZONE...SOME TRAVEL IMPACTS MAY BE OBSERVED WED NIGHT INTO THURSDAY MORNING. WILL MENTION THIS IN THE HWO. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 325 PM CDT TUE MAR 29 2016 WINDY CONDITIONS WILL HIGHLIGHT THURSDAY AND FRIDAY IN THE WAKE OF TWO CLIPPER SYSTEMS. SUB-ADVISORY WINDS NOW FORECAST FOR THURSDAY SO PLAN TO REMOVE THIS WORDING FROM THE HWO. FOR FRIDAY...MODELS BRING IN A DEEPER SFC LOW AND GREATER PRESSURE RISES AS A CLIPPER PUSHES SOUTHEAST ACROSS SOUTH CENTRAL CANADA INTO NORTHERN MINNESOTA. BEST WIND POTENTIAL WILL THUS BE OVER CENTRAL AND EASTERN PORTIONS OF THE STATE. BUFKIT ANALYSIS SUGGESTS ADVISORY CRITERIA WINDS ALONG TO EAST OF HIGHWAY 83 CORRIDOR...THOUGH ONLY SLIGHT MOISTURE CHANCES. NAM BUFKIT INDICATING WARNING CRITERIA WIND MAGNITUDES WITHIN THE MIXED LAYER...SO WILL WANT TO MONITOR THIS OVER THE NEXT DAY OR SO. WILL MENTION THE STRONG WINDS FRIDAY IN THE THE HWO ALONG WITH THE WET SNOW/TRAVEL IMPACT POTENTIAL WED NIGHT INTO THURSDAY. MAINLY QUIET THROUGH THE WEEKEND WITH MODERATING TEMPERATURES. ANOTHER POTENTIAL CLIPPER SYSTEM NEXT WEEK TUESDAY OR WEDNESDAY...THOUGH UNCERTAINTY HIGH. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1217 AM CDT WED MAR 30 2016 MVFR CIGS OVER PTNS OF S CTRL ND WITH -SHRA WILL GRADUALLY IMPROVE THIS MORNING TO VFR LEVELS. REMAINDER OF THE AREA REMAINS MAINLY VFR. THIS EVENING...AREAS OF -RA/-SN WILL DEVELOP FROM NORTHWEST TO SOUTHEAST RESULTING IN CIGS GRADUALLY LOWERING TO MVFR LEVELS WITH LCL IFR VIS IN HEAVIER PRECIPITATION. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJS SHORT TERM...NH LONG TERM...NH AVIATION...JJS
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
834 AM MST WED MAR 30 2016 .SYNOPSIS... A LOW PRESSURE SYSTEM OVER THE WESTERN STATES WILL KEEP MUCH COOLER TEMPERATURES IN PLACE TODAY WITH HIGHS IN THE UPPER 60S TO LOW 70S ACROSS THE LOWER DESERTS. MEAGER PRECIPITATION CHANCES WILL BE LIMITED TO THE HIGHER TERRAIN THROUGH FRIDAY. A WARMING TREND WILL BEGIN THURSDAY AS THE LOW PRESSURE SYSTEM BEGINS TO EXIT THE REGION. A RIDGE OF HIGH PRESSURE BUILDS OVER THE WESTERN STATES THIS WEEKEND WITH TEMPERATURES CLIMBING WELL ABOVE NORMAL. HIGHS WILL REACH THE UPPER 80S TO LOW 90S SUNDAY AND MONDAY. && .DISCUSSION... THE UPPER LEVEL PATTERN REMAINS GENERALLY THE SAME THIS MORNING...WITH THE BIG UPPER LOW STILL ROTATING THROUGH THE GREAT BASIN ONLY SLIGHTLY FURTHER TO THE SOUTH. SEVERAL VORT LOBES/SHORTWAVES REMAIN TRAVELING THROUGH THE LOW CIRCULATION...WITH THE MOST PROMINENT ONE BEGINNING TO SPLIT FROM THE MAIN CIRC CENTER AND CARVE OUT OVER SOUTHERN CA. UPPER JET STREAK HAS ALSO SHIFTED SOUTHWARD WITH OVER 100KT 300MB WINDS OBSERVED ON THE 30/12Z TWC RAOB. TODAY WILL BE SOMEWHAT SIMILAR TO YESTERDAY IN TERMS OF TEMPERATURES AND WINDS...ALBEIT WINDS SHOULD BE LIGHTER THAN THE LAST COUPLE OF DAYS WITHOUT ANY SIGNIFICANT REGIONAL PRESSURE FALLS OCCURRING. SKIES ACROSS THE FORECAST AREA ARE GENERALLY CLEAR...SAVE FOR SOME CU FIELDS EAST ACROSS THE HIGHER TERRAIN AND THE RIM. SOME CU COULD REDEVELOP DOWN OVER THE SOUTH-CENTRAL AZ DESERTS LATER INTO THE AFTERNOON HOWEVER COVERAGE SHOULD NOT EXCEED SCATTERED GIVEN THE ALREADY DRY ENVIRONMENT AND FURTHER DRY AIR ADVECTION FROM THE NORTH. NO UPDATES NEEDED TO THIS MORNING FORECAST PACKAGE...JUST SOME ADJUSTMENTS TO SKY AND TEMP TRENDS TO MATCH CURRENT OBSERVATIONS. && .PREVIOUS DISCUSSION /ISSUED AT 244 AM MST/PDT/... TODAY AND THURSDAY... THE UPPER LOW/TROUGH AFFECTING MUCH OF THE WESTERN STATES IS CENTERED NEAR WEST-CENTRAL UTAH EARLY THIS MORNING. UPSTREAM OF THAT IS A RIDGE WITH AN AXIS LOCATED OFFSHORE. CLOSER TO HOME A VORT MAX WITHIN THE TROUGH HAS MOVED FROM SOUTHEAST CALIFORNIA INTO WESTERN ARIZONA. SHOWER ACTIVITY WITH THAT FEATURE HAS BEEN QUITE WEAK BUT ADDED A MENTION OF SLIGHT CHANCE...FOR VERY LIGHT PRECIP/SPRINKLES OVER PORTIONS OF PORTIONS OF SOUTHWEST ARIZONA AND NORTHWEST MARICOPA COUNTY FOR THE PRE-DAWN HOURS. FURTHER EAST THERE IS ALSO A BAND OF CLOUDINESS THAT HAS DEVELOPED OVER PORTIONS OF SOUTH-CENTRAL ARIZONA...SIMILAR TO YESTERDAY MORNING BUT NOT AFFECTING NEAR AS MUCH OF THE PHOENIX AREA. THIS APPEARS TO BE ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE JET TRACKING ACROSS ARIZONA. NCEP HI-RES ARW AND NMM AS WELL AS SREF DEPICT VERY MODEST QPF THERE. THUS ADDED MENTION OF SLIGHT CHANCE TO HIGHER TERRAIN OF SOUTHERN GILA COUNTY FOR THE MORNING HOURS. COULDNT RULE OUT SPRINKLES IN THE FAR EAST VALLEY AND PORTIONS OF PINAL COUNTY BUT MEASURABLE PRECIP CHANCES TOO LOW TO MENTION. AS THE SHORT WAVE DEPARTS...POPS EAST OF PHOENIX DROP OFF THIS AFTERNOON BUT REDEVELOP OVER JOSHUA TREE NATIONAL PARK AS ANOTHER VORT MAX DROPS DOWN FROM NEVADA. LATEST RAP FORECAST SOUNDING FOR JTNP EVEN DEVELOP A LITTLE BIT OF CAPE...BUT NONE FOR BLYTHE. DESPITE THE ARRIVAL OF THIS WAVE...HEIGHTS ACTUALLY RISE SLIGHTLY AS THE MAIN PORTION OF THE SYSTEM BEGINS SHIFTING EAST. THE SHORT WAVE WILL BECOME A CLOSED LOW WITHIN THE TROUGH TONIGHT THEN TRACK SOUTHEASTWARD TO THE BORDERLANDS THURSDAY AND WEAKEN IN THE PROCESS. AS FOR TEMPERATURES ANOTHER REFRESHINGLY COOL DAY TODAY WITH VERY SIMILAR HIGH TEMPERATURES AS TUESDAY. THEN A WARMING TREND BEGINS THURSDAY. WINDS WILL BE LIGHT TODAY WITH SOME MINOR BREEZINESS THURSDAY. FRIDAY THROUGH TUESDAY... ON FRIDAY...THE RIDGE BEGINS TO MOVE IN AND THE WARMING TREND CONTINUES. HOWEVER...WITH NORTHERLY FLOW IN PLACE...A FINAL SHORT WAVE MAKES ITS WAY INTO ARIZONA FOR ONE LAST SLIGHT CHANCE OF MEAGER PRECIP FOR OUR EASTERNMOST HIGHER TERRAIN. OVER THE WEEKEND...THE RIDGE SLOWLY ADVANCES INLAND WITH TEMPERATURES REACHING THE UPPER 80S TO LOW 90S BY SUNDAY FOR THE LOWER DESERTS INCLUDING PHOENIX. MODELS GENERALLY AGREE ON THE RIDGE AXIS BEGINNING TO SHIFT EASTWARD ON MONDAY BUT THERE WILL STILL BE SOME ADDITIONAL WARMING WITH LOW 90S COMMON. ON TUESDAY...THE RIDGE LOOKS TO BE WEAKER DUE TO A NORTHERN BRANCH TROUGH MOVING INLAND AND A SOUTHERN BRANCH TROUGH NUDGING CLOSER TO SOUTHERN CALIFORNIA AND MEXICO. THE SOUTHERN BRANCH TROUGH HAVE MORE AFFECT ON US DUE TO CIRRUS SPREADING OVERHEAD. THUS TEMPS DIP DOWN A BIT ON TUESDAY BUT STILL WELL ABOVE NORMAL. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... WESTERLY SYNOPTIC FLOW JUST ABOVE THE SURFACE SHOULD KEEP THE DOWNSLOPE EASTERLY WINDS AT BAY THIS MORNING. CONFIDENCE IS FAIRLY HIGH THAT KPHX WILL KEEP WEST WINDS EXCEPT FOR A BRIEF PERIOD OF VARIABLE TO SOUTHERLY LIGHT WINDS SHORTLY AFTER SUNRISE. KIWA HAS A BETTER SHOT AT GOING EASTERLY FOR A FEW HOURS...BUT NOT SURE THING. BY MID MORNING...WESTERLY WINDS WILL TAKE OVER AS MIXING COMMENCES AND LAST THROUGH THE EVENING BEFORE GRADUALLY SWITCHING OVER TO EASTERLIES TONIGHT. WILL SEE PERIODIC CU WITH BASES OF 8-10K FEET LASTING THROUGH EARLY EVENING...MOST TIMES EITHER FEW OR SCT. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... LIGHT WESTERLY PREDOMINANT WINDS EXPECTED THROUGH THE PERIOD WITH MOSTLY CLEAR SKIES. LIKELY WILL SEE SOME PERIODIC FEW TO SCT CU STARTING LATE THIS MORNING. NO AVIATION IMPACTS EXPECTED THROUGH THURSDAY MORNING. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... FRIDAY THROUGH TUESDAY... LOW PRESSURE WILL EXIT THE REGION LATE THIS WEEK WITH A STRONG UPPER LEVEL RIDGE BUILDING IN FROM THE WEST. BREEZY NORTHERLY WINDS ARE LIKELY DOWN THE LOWER COLORADO RIVER VALLEY ON FRIDAY. REBOUNDING TEMPERATURES WILL ALLOW FOR WIDESPREAD 80S FOR FRIDAY AND SATURDAY AND EVEN SOME LOWER 90S BY SUNDAY. DRY CONDITIONS WILL DOMINATE THROUGH THE ENTIRE PERIOD WITH MINIMUM AFTERNOON HUMIDITIES MOSTLY IN THE SINGLE DIGITS ACROSS THE LOWER DESERTS. NO SIGNIFICANT WINDS ARE EXPECTED OVER THE WEEKEND INTO EARLY NEXT WEEK...JUST TYPICAL AFTERNOON LOCAL GUSTINESS FAVORING UPSLOPE OR THE SOUTHWEST. && .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...NOLTE PREVIOUS DISCUSSION...AJ AVIATION...KUHLMAN FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
519 AM MST WED MAR 30 2016 .UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS... && .SYNOPSIS... A LOW PRESSURE SYSTEM OVER THE WESTERN STATES WILL KEEP MUCH COOLER TEMPERATURES IN PLACE TODAY WITH HIGHS IN THE UPPER 60S TO LOW 70S ACROSS THE LOWER DESERTS. MEAGER PRECIPITATION CHANCES WILL BE LIMITED TO THE HIGHER TERRAIN THROUGH FRIDAY. A WARMING TREND WILL BEGIN THURSDAY AS THE LOW PRESSURE SYSTEM BEGINS TO EXIT THE REGION. A RIDGE OF HIGH PRESSURE BUILDS OVER THE WESTERN STATES THIS WEEKEND WITH TEMPERATURES CLIMBING WELL ABOVE NORMAL. HIGHS WILL REACH THE UPPER 80S TO LOW 90S SUNDAY AND MONDAY. && .DISCUSSION... TODAY AND THURSDAY... THE UPPER LOW/TROUGH AFFECTING MUCH OF THE WESTERN STATES IS CENTERED NEAR WEST-CENTRAL UTAH EARLY THIS MORNING. UPSTREAM OF THAT IS A RIDGE WITH AN AXIS LOCATED OFFSHORE. CLOSER TO HOME A VORT MAX WITHIN THE TROUGH HAS MOVED FROM SOUTHEAST CALIFORNIA INTO WESTERN ARIZONA. SHOWER ACTIVITY WITH THAT FEATURE HAS BEEN QUITE WEAK BUT ADDED A MENTION OF SLIGHT CHANCE...FOR VERY LIGHT PRECIP/SPRINKLES OVER PORTIONS OF PORTIONS OF SOUTHWEST ARIZONA AND NORTHWEST MARICOPA COUNTY FOR THE PRE-DAWN HOURS. FURTHER EAST THERE IS ALSO A BAND OF CLOUDINESS THAT HAS DEVELOPED OVER PORTIONS OF SOUTH-CENTRAL ARIZONA...SIMILAR TO YESTERDAY MORNING BUT NOT AFFECTING NEAR AS MUCH OF THE PHOENIX AREA. THIS APPEARS TO BE ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE JET TRACKING ACROSS ARIZONA. NCEP HI-RES ARW AND NMM AS WELL AS SREF DEPICT VERY MODEST QPF THERE. THUS ADDED MENTION OF SLIGHT CHANCE TO HIGHER TERRAIN OF SOUTHERN GILA COUNTY FOR THE MORNING HOURS. COULDNT RULE OUT SPRINKLES IN THE FAR EAST VALLEY AND PORTIONS OF PINAL COUNTY BUT MEASURABLE PRECIP CHANCES TOO LOW TO MENTION. AS THE SHORT WAVE DEPARTS...POPS EAST OF PHOENIX DROP OFF THIS AFTERNOON BUT REDEVELOP OVER JOSHUA TREE NATIONAL PARK AS ANOTHER VORT MAX DROPS DOWN FROM NEVADA. LATEST RAP FORECAST SOUNDING FOR JTNP EVEN DEVELOP A LITTLE BIT OF CAPE...BUT NONE FOR BLYTHE. DESPITE THE ARRIVAL OF THIS WAVE...HEIGHTS ACTUALLY RISE SLIGHTLY AS THE MAIN PORTION OF THE SYSTEM BEGINS SHIFTING EAST. THE SHORT WAVE WILL BECOME A CLOSED LOW WITHIN THE TROUGH TONIGHT THEN TRACK SOUTHEASTWARD TO THE BORDERLANDS THURSDAY AND WEAKEN IN THE PROCESS. AS FOR TEMPERATURES ANOTHER REFRESHINGLY COOL DAY TODAY WITH VERY SIMILAR HIGH TEMPERATURES AS TUESDAY. THEN A WARMING TREND BEGINS THURSDAY. WINDS WILL BE LIGHT TODAY WITH SOME MINOR BREEZINESS THURSDAY. FRIDAY THROUGH TUESDAY... ON FRIDAY...THE RIDGE BEGINS TO MOVE IN AND THE WARMING TREND CONTINUES. HOWEVER...WITH NORTHERLY FLOW IN PLACE...A FINAL SHORT WAVE MAKES ITS WAY INTO ARIZONA FOR ONE LAST SLIGHT CHANCE OF MEAGER PRECIP FOR OUR EASTERNMOST HIGHER TERRAIN. OVER THE WEEKEND...THE RIDGE SLOWLY ADVANCES INLAND WITH TEMPERATURES REACHING THE UPPER 80S TO LOW 90S BY SUNDAY FOR THE LOWER DESERTS INCLUDING PHOENIX. MODELS GENERALLY AGREE ON THE RIDGE AXIS BEGINNING TO SHIFT EASTWARD ON MONDAY BUT THERE WILL STILL BE SOME ADDITIONAL WARMING WITH LOW 90S COMMON. ON TUESDAY...THE RIDGE LOOKS TO BE WEAKER DUE TO A NORTHERN BRANCH TROUGH MOVING INLAND AND A SOUTHERN BRANCH TROUGH NUDGING CLOSER TO SOUTHERN CALIFORNIA AND MEXICO. THE SOUTHERN BRANCH TROUGH HAVE MORE AFFECT ON US DUE TO CIRRUS SPREADING OVERHEAD. THUS TEMPS DIP DOWN A BIT ON TUESDAY BUT STILL WELL ABOVE NORMAL. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... WESTERLY SYNOPTIC FLOW JUST ABOVE THE SURFACE SHOULD KEEP THE DOWNSLOPE EASTERLY WINDS AT BAY THIS MORNING. CONFIDENCE IS FAIRLY HIGH THAT KPHX WILL KEEP WEST WINDS EXCEPT FOR A BRIEF PERIOD OF VARIABLE TO SOUTHERLY LIGHT WINDS SHORTLY AFTER SUNRISE. KIWA HAS A BETTER SHOT AT GOING EASTERLY FOR A FEW HOURS...BUT NOT SURE THING. BY MID MORNING...WESTERLY WINDS WILL TAKE OVER AS MIXING COMMENCES AND LAST THROUGH THE EVENING BEFORE GRADUALLY SWITCHING OVER TO EASTERLIES TONIGHT. WILL SEE PERIODIC CU WITH BASES OF 8-10K FEET LASTING THROUGH EARLY EVENING...MOST TIMES EITHER FEW OR SCT. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... LIGHT WESTERLY PREDOMINANT WINDS EXPECTED THROUGH THE PERIOD WITH MOSTLY CLEAR SKIES. LIKELY WILL SEE SOME PERIODIC FEW TO SCT CU STARTING LATE THIS MORNING. NO AVIATION IMPACTS EXPECTED THROUGH THURSDAY MORNING. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... FRIDAY THROUGH TUESDAY... LOW PRESSURE WILL EXIT THE REGION LATE THIS WEEK WITH A STRONG UPPER LEVEL RIDGE BUILDING IN FROM THE WEST. BREEZY NORTHERLY WINDS ARE LIKELY DOWN THE LOWER COLORADO RIVER VALLEY ON FRIDAY. REBOUNDING TEMPERATURES WILL ALLOW FOR WIDESPREAD 80S FOR FRIDAY AND SATURDAY AND EVEN SOME LOWER 90S BY SUNDAY. DRY CONDITIONS WILL DOMINATE THROUGH THE ENTIRE PERIOD WITH MINIMUM AFTERNOON HUMIDITIES MOSTLY IN THE SINGLE DIGITS ACROSS THE LOWER DESERTS. NO SIGNIFICANT WINDS ARE EXPECTED OVER THE WEEKEND INTO EARLY NEXT WEEK...JUST TYPICAL AFTERNOON LOCAL GUSTINESS FAVORING UPSLOPE OR THE SOUTHWEST. && .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...AJ AVIATION...KUHLMAN FIRE WEATHER...KUHLMAN Area Forecast Discussion National Weather Service Lincoln IL 1046 AM CDT WED MAR 30 2016 .UPDATE... Issued at 1045 AM CDT Wed Mar 30 2016 Forecast is pretty much on track today with scatteres showers and a few thunderstorms spreading ne across areas from I-55 west at lat this morning. Had pea size hail (1/4 inch) recently reported in Springfield with a thunderstorm. Most of the lightning activity is currently in eastern Sangamon county, and there was some lightning in past hour near Tazewell and Logan county border. 15Z surface map shows 998 mb low pressure over central Nebraska with a cold front through central KS into nw Texas/OK. Breezy sse winds of 12-20 mph and gusts of 20-30 mph over central IL this morning. 1030 am temps were in the low to mid 50s with dewpoints in the mid to upper 30s. RAP, HRRR and NAM models show scattered showers along with chances of thunderstorms spreading over eastern IL during the afternoon. SPC has marginal risk of severe storms for areas from highway 51 west this afternoon into tonight, with 5-15% risk of hail and high winds and just 2% risk of tornadoes. RAP and NAM show low MUCAPES peaking from 200-400 j/kg over western CWA today while high shear of 45-60 kts in western CWA with highest shear nw of IL river. Better chance of severe storms is west of IL this afternoon/tonight where stronger instability/higher CAPES. Highs this afternoon in the low to mid 60s with upper 60s southeast of I-70 and from Jacksonville sw. && .SHORT TERM...(Today) ISSUED AT 300 AM CDT Wed Mar 30 2016 The recent stretch of quiet weather across central and southeast Illinois will come to an end today as a slow moving storm system approaches the area. The upper-level low driving the system is still spinning across the southwest U.S., but it is expected to translate into the central High Plains by this evening as it begins to open up and become absorbed into a digging northern stream trof. Strong southerly flow ahead of the system will transport moisture into the initially very dry airmass across the forecast area this morning. This moisture will be acted on by a lead short wave ejecting out of the southwest system, and associated enhanced WAA/isentropic ascent. The stronger winds aloft will help minimize surface based instability today, but fairly steep mid-level lapse rates will still support elevated convection. Expect numerous showers and scattered thunderstorms to break out from late morning into the afternoon hours as the forcing moves in and the atmosphere has time to moisten. The elevated warm layer will keep winds from getting as strong today as they might otherwise be, but the surface gradient and potential mixing still support gusts over 30 mph by afternoon. The strong southerly winds, aside from transporting moisture into the area, will also boost temperatures well above normal. Despite the increasing clouds and precipitation threat, expect afternoon highs to top out well into the 60s. A few 70s are possible as well. .LONG TERM...(Tonight through Tuesday) ISSUED AT 300 AM CDT Wed Mar 30 2016 Large upper low along the Utah/Nevada borer expected to contract as it moves east today, reaching the northeast corner of Colorado this evening before it starts to get drawn into the trough dropping across Manitoba/western Ontario. Secondary trough expected to drop southeast from the Dakotas on Thursday as a broad trough digs southward from Ontario. These will be the main players over the next couple days in terms of rain chances over our area. Despite very high PoP`s over the area tonight, none of the models are indicating a solid, continuous rain shield, although areas south of I-70 would see the best odds of this happening as a cluster of stronger thunderstorms tracks along the lower Ohio River. Thus, precipitation will be covered with "occasional" wording. Best thunder chances will be west of highway 51 as CAPE`s rise to 500- 1000 J/kg. As the storm system has been slowing down in recent model runs, have made some significant adjustments to PoP`s on Thursday and increased them to 50-60% along and east of I-57 around midday and early afternoon. Latest SPC Day2 outlook introduced a slight risk of severe storms from about Danville-Effingham eastward, as CAPE`s rise to around 1500 J/kg and 0-6km bulk shear ramps up to around 60-70 knots. Leaned more toward the GFS timing, which has the surface front exiting the southeast CWA by late afternoon. With the slower frontal passage, have increased highs by several degrees Thursday, with most areas east of I-55 reaching around 70 degrees. Made little change to PoP`s for late Thursday night and Friday, as the secondary trough swings through the area. As it exits, the upper pattern will continue to focus a strong northwest flow into the Midwest, although the colder air will provide more of a glancing blow. Saturday night looks to be the best chance of temperatures near or below freezing, as an area of high pressure sinks southeast toward the Ohio Valley. However, a secondary surge of cooler air is progged to swing through Monday night. && .AVIATION...(For the 12Z TAFS through 12Z Thursday morning) Issued at 647 AM CDT Wed Mar 30 2016 LLWS is present to start the day across the central Illinois terminals. However, within the next couple of hours, some of the stronger winds aloft will mix down, with gusty southerly surface winds persisting through the rest of the 12Z TAF valid time. VFR conditions will degrade to MVFR, and possibly IFR by tonight, as showers and thunderstorms become more numerous with the approach of a storm system. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...07 SHORT TERM...BAK LONG TERM...Geelhart AVIATION...BAK
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
630 AM CDT WED MAR 30 2016 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 351 AM CDT WED MAR 30 2016 An intense upper low across western UT and western AZ will shear apart with one section of the upper trough lifting northeast across CO into NE, which will amplify as it phases with a northern branch upper trough digging southeast across the northern plains. The upper trough will then move east across NE and KS Tonight. As the H5 trough lifts northeast across CO into western NE and KS an H5 jet max of 55 to 60 KTS will spread northeast across eastern KS during the afternoon and evening hours. The mesoscale models such as the ARW and NMM version of the WRF and the GFS show a round of elevated thunderstorms developing as the upper jet lifts northeast from the TX PNHDL into western and central KS this morning. If these models turn out to be accurate then precip chances will be higher across the CWA during the mid and late morning hours. These elevated storms may rotate due to the increasing vertical windshear,so I can not rule out some large hail. However, the NAM and RAP models do not show elevated storms developing through the morning hours. This afternoon and evening, the surface trough and dryline will be moving east from western KS across central KS into the western counties of the CWA. There are difference in the speed of the dryline eastward progress. Most numerical model solutions move the surface dryline along a Seneca, to Manhattan line by 6 PM this evening. Surface convergence ahead of the dryline combined with ascent ahead of the H5 trough will break the weak cap and cause scattered thunderstorms to develop across northeast and east central KS. Every model shows there will be good vertical windshear and MLCAPE of 1500 J/KG to 2500 J/KG. The NAM models seems a bit too high with forecasting around 3000 J/KG of MLCAPE across east central KS. Instability will depend on how much elevated convection develops this morning, if any, and if there will be any insolation for surface heating ahead of the dryline. I think there will be widely scattered elevated thunderstorms during the mid morning hours but these storms should move northeast into MO by noon, then we should see some breaks in the OVC for surface heating ahead of the dryline. Given an environment with good vertical windshear and sufficient instability, we should see developing thunderstorms late this afternoon become supercell thunderstorms. The models due vary quite a bit on how much low-level vertical windshear will develop ahead of the dryline. The WRF model solutions show surface and 850mb winds to veer across the warm sector late this afternoon and early this evening. 0-1 KM SRH values are only 50 to 100 J/kg. Meanwhile the NAM model solution and to some extent the RAP model have surface winds a bit more backed and 850mb winds are not as veered. The NAM develops about 100 to 200 j/kg of SRH, which would be more conducive for any supercell thunderstorms to produce tornadoes. Even if winds are a bit veered as the mesoscale models forecast, I cannot rule out a few weak tornadoes. If the low-level winds back more ahead of the dryline then the tornado threat will be greater and the tornadoes may be more intense. Any supercell thunderstorms will also produce large hail and damaging wind gusts. Most of the numerical models shift the threat for severe storms east of the CWA during the mid evening hours. The NAM model hangs up the dryline across the eastern counties of the CWA and storms continue to shift northeast across east central KS. I think over the mid evening hours the isolated supercells will evolve into line segment with the main hazards being damaging winds and perhaps some flash flooding if training of storms occur across the southeast counties of the CWA. The NAM model finally shifts the thunderstorms east of the CWA after midnight. .LONG TERM...(Thursday through Tuesday) Issued at 351 AM CDT WED MAR 30 2016 Early Thursday morning a shortwave on the base of the main upper level trough will be over northeast Kansas. There remains a small chance for rain near the Nebraska boarder Thursday morning with soundings showing decent saturation and forcing in the lower levels of the atmosphere. Most the afternoon Thursday should be dry across the area before another shortwave passes just north of the area and rain chances clip extreme northeast Kansas. From here, precipitation chances end for the rest of the period. Winds shift from the south overnight Saturday, leading to a warm and dry Sunday with highs in the middle to low 70s. Sunday afternoon these southerly winds will gust up to 25kts, creating possible elevated fire concerns for this day. The rest of the period stays mild with highs generally in the upper 60s or low 70s and lows in the 40s. && .AVIATION...(For the 12Z TAFS through 12Z Thursday Morning) Issued at 622 AM CDT WED MAR 30 2016 MVFR cigs will continue through through the early afternoon hours at all terminals. Thunderstorms will be possible after 21Z at all terminals. The threat for thunderstorms will continue into the evening and early overnight hours before a cold front pushes all activity to the east. The cold front will also shift winds to a WNW direction by 4Z in MHK and 6Z at the Topeka terminals. Low cigs are possible behind the cold front, however confidence is too low at this point to introduce MVFR or lower cigs. Will reevaluate in later outlooks. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Gargan LONG TERM...Heller AVIATION...Baerg
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1131 AM EDT WED MAR 30 2016 .SYNOPSIS... HIGH PRESSURE WILL PROVIDE DRY WEATHER TODAY. A COLD FRONT WILL RETURN SHOWERS TO THE FORECAST THURSDAY AND FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FURTHER TWEAK TO TEMPS/DEWPOINTS FOR THE AFTERNOON. DEWPOINTS WERE MAINLY RAISED SLIGHTLY TO BETTER MATCH OBS AND LATEST HRRR GRIDS. REST UNCHANGED FOR NOW. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... AN UPPER TROUGH IS PROGGED TO ADVANCE FROM THE PLAINS/MIDWEST REGION TO THE GREAT LAKES BY FRIDAY. A STRONG SHORTWAVE AHEAD OF THE SYSTEM WILL CROSS THE AREA ON THURSDAY. LATEST MODEL SOLUTIONS ARE A BIT SLOWER WITH THIS FEATURE SO SLOWED THE ONSET OF POPS LATE TONIGHT. MAINTAINED CATEGORICAL POPS THURSDAY DUE TO THE DEEP MOISTURE...LARGE SCALE ASCENT...AND LOW LEVEL JET SUPPORT. A THUNDERSTORM IS POSSIBLE THURSDAY AFTERNOON...BUT OVERALL INSTABILITY IS WEAK. KEPT IN THE PREVIOUS THINKING OF CHANCE STORMS IN THE FORECAST. SURFACE LOW PRESSURE IS EXPECTED TO TRACK FROM THE UPPER MIDWEST TO ONTARIO FRIDAY. TRAILING COLD FRONT WILL CROSS THE AREA LATE THURSDAY NIGHT AND FRIDAY MORNING. INTRODUCED A BRIEF INCREASE IN POPS WITH FRONTAL PASSAGE AND ALSO INCLUDED THE MENTION OF THUNDER. TEMPERATURES SHOULD AVERAGE AROUND 10 DEGREES ABOVE SEASONAL AVERAGES UNTIL THE FRONT USHERS IN COLDER AIR ON FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... A BROAD UPPER TROUGH IS PROGGED ACROSS THE NORTHEASTERN CONUS THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. COLD AIR REINFORCING SHORTWAVES...ADVANCING THROUGH THE TROUGH...SHOULD KEEP PERIODIC RAIN/SNOW SHOWERS CHANCES AND BELOW AVERAGE TEMPERATURES THROUGH MOST OF THE LONG TERM. ADJUSTED SUPERBLEND GUIDANCE WAS USED FOR THE FORECAST TO SMOOTH OUT OPERATIONAL MODEL DIFFERENCES. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... NEARLY CALM WIND EARLY THIS MORNING WILL QUICKLY TURN SOUTHEAST THEN SOUTHERLY AND BECOME GUSTY THIS AFTERNOON. SOUTHERLY WIND WILL CONTINUE INTO THE EVENING...EVEN AS GUSTS DECREASE. HIGH CLOUDS WILL INCREASE INTO THE EVENING WHILE A SOUTHWESTERLY LOW LEVEL JET OF AROUND 50 KTS MOVES OVER THE AREA. THIS WILL ALLOW FOR LLWS TO INCREASE OVERNIGHT. .OUTLOOK /WEDNESDAY NIGHT THROUGH SUNDAY/... PERIODIC RESTRICTIONS ARE LIKELY WITH A THU/FRI COLD FRONT...AND THRU THE WEEKEND WITH SUBSEQUENT UPPER TROUGHING. && .FIRE WEATHER... GUSTY WINDS AND LOW HUMIDITY LEVELS ARE STILL EXPECTED THIS AFTERNOON. CALLS TO FORESTRY PARTNERS INDICATED THAT FUELS WERE SUFFICIENTLY MOIST TO PRECLUDE THE NEED FOR RED FLAG WARNINGS OVER OUR AREA. WE WILL CONTINUE TO MONITOR CONDITIONS THIS AFTERNOON. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
929 AM EDT WED MAR 30 2016 .SYNOPSIS... HIGH PRESSURE WILL PROVIDE DRY WEATHER TODAY. A COLD FRONT WILL RETURN SHOWERS TO THE FORECAST THURSDAY AND FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MAIN CHANGE WAS TO LOWER DEWPOINTS/RH SOMEWHAT FOR THE AFTERNOON. 12Z SOUNDING SHOWS A VERY DRY LAYER ABOVE THE SURFACE THAT WILL LIKELY MIX DOWN. USED HRRR DEWPOINTS AS A STARTING POINT WITH SOME TWEAKS. MINOR CHANGES TO TEMPERATURES AS WELL. REST UNCHANGED FOR NOW. WILL CONTINUE TO MONITOR FIRE WEATHER CONDITIONS. PREVIOUS DISCUSSION... HIGH PRESSURE WILL KEEP THE AREA DRY TODAY...WITH PLENTY OF SUNSHINE. AS SURFACE HIGH DRIFTS EASTWARD...SOUTH-SOUTHWESTERLY FLOW WILL PROMOTE WARMER AIR OVERSPREADING THE REGION WITH GUSTY SOUTHERLY WINDS INCREASING THROUGH THE AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... AN UPPER TROUGH IS PROGGED TO ADVANCE FROM THE PLAINS/MIDWEST REGION TO THE GREAT LAKES BY FRIDAY. A STRONG SHORTWAVE AHEAD OF THE SYSTEM WILL CROSS THE AREA ON THURSDAY. LATEST MODEL SOLUTIONS ARE A BIT SLOWER WITH THIS FEATURE SO SLOWED THE ONSET OF POPS LATE TONIGHT. MAINTAINED CATEGORICAL POPS THURSDAY DUE TO THE DEEP MOISTURE...LARGE SCALE ASCENT...AND LOW LEVEL JET SUPPORT. A THUNDERSTORM IS POSSIBLE THURSDAY AFTERNOON...BUT OVERALL INSTABILITY IS WEAK. KEPT IN THE PREVIOUS THINKING OF CHANCE STORMS IN THE FORECAST. SURFACE LOW PRESSURE IS EXPECTED TO TRACK FROM THE UPPER MIDWEST TO ONTARIO FRIDAY. TRAILING COLD FRONT WILL CROSS THE AREA LATE THURSDAY NIGHT AND FRIDAY MORNING. INTRODUCED A BRIEF INCREASE IN POPS WITH FRONTAL PASSAGE AND ALSO INCLUDED THE MENTION OF THUNDER. TEMPERATURES SHOULD AVERAGE AROUND 10 DEGREES ABOVE SEASONAL AVERAGES UNTIL THE FRONT USHERS IN COLDER AIR ON FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... A BROAD UPPER TROUGH IS PROGGED ACROSS THE NORTHEASTERN CONUS THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. COLD AIR REINFORCING SHORTWAVES...ADVANCING THROUGH THE TROUGH...SHOULD KEEP PERIODIC RAIN/SNOW SHOWERS CHANCES AND BELOW AVERAGE TEMPERATURES THROUGH MOST OF THE LONG TERM. ADJUSTED SUPERBLEND GUIDANCE WAS USED FOR THE FORECAST TO SMOOTH OUT OPERATIONAL MODEL DIFFERENCES. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... NEARLY CALM WIND EARLY THIS MORNING WILL QUICKLY TURN SOUTHEAST THEN SOUTHERLY AND BECOME GUSTY THIS AFTERNOON. SOUTHERLY WIND WILL CONTINUE INTO THE EVENING...EVEN AS GUSTS DECREASE. HIGH CLOUDS WILL INCREASE INTO THE EVENING WHILE A SOUTHWESTERLY LOW LEVEL JET OF AROUND 50 KTS MOVES OVER THE AREA. THIS WILL ALLOW FOR LLWS TO INCREASE OVERNIGHT. .OUTLOOK /WEDNESDAY NIGHT THROUGH SUNDAY/... PERIODIC RESTRICTIONS ARE LIKELY WITH A THU/FRI COLD FRONT...AND THRU THE WEEKEND WITH SUBSEQUENT UPPER TROUGHING. && .FIRE WEATHER... AN ENHANCED FIRE RISK IS POSSIBLE TODAY...PARTICULARLY THIS AFTERNOON. LOW RELATIVE HUMIDITIES...GUSTY WINDS...AND LOW FUELS WILL COMBINE TO INCREASE THE THREAT OF FIRES. CURRENTLY THE DRIEST RELATIVE HUMIDITIES ARE EXPECTED TO BE ISOLATED AND SHORT LIVED THIS AFTERNOON. IF CONDITIONS WORSEN OR LOW HUMIDITIES BECOME MORE WIDESPREAD...A FIRE HEADLINE MAY BE NEEDED. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION...CORRECTED
NWS CHICAGO/ROMEOVILLE, IL
1253 PM CDT WED MAR 30 2016 .UPDATE... 1134 AM CDT WIDELY SCATTERED SHOWERS HAVE DEVELOPED OVER PORTIONS OF NORTHEASTERN ILLINOIS ALONG THE LEADING EDGE OF THE BETTER MOISTURE TRANSPORT. ADDITIONAL SHOWERS...AND THUNDERSTORMS WILL LIKELY CONTINUE TO DEVELOP INTO CENTRAL PORTIONS OF THE STATE INTO THE EARLY AFTERNOON...AND SOME OF THESE STORMS WILL LIKELY SHIFT ACROSS SOME OF MY SOUTHERN COUNTIES THROUGH EARLY AFTERNOON. ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS ALSO LOOK TO DEVELOP THIS AFTERNOON AND IMPACT THE AREA BY MID TO LATE AFTERNOON. THE SEVERE THREAT WITH THESE STORM LOOKS LOW. THE MAIN CONCERN FOR SEVERE THUNDERSTORMS WILL BE ON THURSDAY. MODEL GUIDANCE CONTINUES TO SLOW THE PROGRESSION OF THE SURFACE COLD FRONT OVER THE AREA ON THURSDAY. AS A RESULT...IT APPEARS THE SEVERE WEATHER THREAT WILL ALSO EXTEND INTO EASTERN ILLINOIS AND NORTHWESTERN INDIANA DURING THE LATE MORNING THROUGH AT LEAST THE MID AFTERNOON HOURS...WHICH LOOKS TO INCLUDE AT LEAST PORTIONS OF THE CHICAGO AREA. THIS SLOWER FRONTAL TIMING LOOKS TO ALLOW TEMPERATURES TO WARM WELL INTO THE 60S TO NEAR 70 WITHIN THE PREFRONTAL AIRMASS...AND THIS IN COMBINATION WITH DEWPOINTS EXPECTED TO BE NEAR 60 BENEATH A CORRIDOR OF STEEPENING MID-LEVEL LAPSE RATES...MLCAPE VALUES IN EXCESS OF 1000 J/KG APPEAR TO BE VERY POSSIBLE. THE KINEMATIC FIELD OVER THE AREA LOOKS IMPRESSIVE...WITH A MID LEVEL JET (AROUND 500 MB) EXPECTED TO BE NEAR 70 KT...WHICH SHOULD RESULT IN VERY STRONG DEEP LAYER SHEAR. A MAINLY UNIDIRECTIONAL SHEAR PROFILE SUGGESTS STRONG AND DAMAGING WINDS WILL BE GOOD THREAT WITH THESE STORMS. HOWEVER...THERE COULD ALSO BE DECENT THREATS OF LARGE HAIL GIVEN THE GOOD POTENTIAL FOR SUPER CELL STORM STRUCTURES. KJB && .SHORT TERM... 331 PM CDT THROUGH TONIGHT... VERY DIFFICULT FORECAST THROUGH TONIGHT. CLOUD COVER IS LIMITING WARMING AND MIXING...AND LOWERED WIND SPEEDS AND TEMPS ACCORDINGLY THIS MORNING. HOWEVER...STARTING TO SEE HOLES IN THE CLOUD COVER AND WINDS ARE BEGINNING TO PICK UP. GUSTS TO 30 MPH ARE EXPECTED AND CANNOT RULE OUT OCNL GUSTS TO 35 MPH. HAVE VERY LOW CONFIDENCE IN RAIN AND THUNDER OCCURRENCE AND COVERAGE THROUGH THIS AFTN DUE TO NO CLEAR FORCING AND 15+ DEGREE SFC DEWPOINT DEPRESSIONS. THINKING THE BETTER STORM COVERAGE WILL BE SOUTH OF I-80 WHERE SHOWERS ARE ON RADAR...BUT THUNDER IS STILL STRUGGLING. WHILE SOME OF THE HI-RES MODELS SUGGEST RAIN COULD TAKE SOME TIME TO FORM THIS EVENING...STILL THINKING WE WILL SEE WIDESPREAD RAIN WITH A FEW THUNDERSTORMS. HAVE LOW CONFIDENCE IN THUNDER COVERAGE OVERNIGHT. THINKING THE BETTER COVERAGE OF STORMS WILL BE ACROSS CENTRAL IL THIS EVENING. WITH A DYING TREND AS THE SYSTEM SHIFTS EAST OVERNIGHT. STILL EXPECTING A MILD NIGHT WITH GUSTY SOUTH TO SOUTHWEST WINDS. WHILE FOG IS EXPECTED OVER THE LAKE...THINKING RAIN AND GUSTY WINDS WILL NOT ALLOW FOG TO FORM OVER LAND. HOWEVER...STRONGER RAIN SHOWERS COULD CERTAINLY REDUCE VISIBILITY. JEE && .LONG TERM... 1253 PM CDT FRIDAY THROUGH WEDNESDAY... SUBTLE NW FLOW SHORTWAVE IS PROGGED TO MOVE ACROSS THE REGION FRIDAY AND WHEN COMBINED WITH COLD AIR ALOFT AND STEEP LAPSE RATES SHOULD SUPPORT AT LEAST WIDELY SCATTERED SHOWERS DURING THE AFTERNOON. GIVEN THE LOW FREEZING LEVELS AND A STEEP LAPSE RATES ITS POSSIBLE THAT THE MORE VIGOROUS SHOWERS COULD HAVE SOME GRAUPEL (MUSHY HAIL) OR PERHAPS EVEN A WET SNOWFLAKE OR TWO. MUCH MORE VIGOROUS CLIPPER-LIKE SYSTEM IS PROGGED TO DROP SOUTHEAST INTO THE GREAT LAKES REGION SATURDAY. SURFACE LOW SHOULD TRACK NORTH OF OUR AREA PUTTING US ON THE DRY SIDE OF THE SYSTEM WITH LITTLE/NO PRECIP EXPECTED...HOWEVER LATE SEASON ARCTIC FRONT IS PROGGED TO MOVE THROUGH DURING THE AFTERNOON BRINGING COLDER TEMPERATURES BUT MORE NOTICEABLY A PERIOD OF STRONG NORTHWEST WINDS. COLD AIR BEHIND THE FRONT SHOULD BE SHORT LIVED AS ANOTHER STRONG CLIPPER TRACK SOUTHEAST INTO THE REGION SUNDAY NIGHT WITH WARM AIR ADVECTION IN ADVANCE OF THIS CLIPPER COMMENCING SUNDAY AFTERNOON. LATEST GFS/ECMWF TRACK THIS SYSTEM FAR ENOUGH NORTH TO SUPPORT ALL RAIN FOR OUR CWA...AND IF IT TRACKS MUCH FARTHER NORTH WE COULD STAY DRY ALTOGETHER. DID MAINTAIN A RAIN/SNOW CHANCE SUNDAY NIGHT AS A SOUTHWARD SHIFT IN THE FORECAST TRACK OF THE SYSTEM COULD PUT US CLOSER TO THE RAIN-SNOW LINE. SYSTEM IS PROGGED TO BE RATHER VIGOROUS WITH STRONG ASCENT IN THE RIGHT ENTRANCE REGION OF >100KT 250MB JET ACCOMPANIED BY STEEP MID-LEVEL LAPSE RATES...SO COULD EVEN SOME SOME CONVECTIVE ELEMENTS TO THE PRECIP. PLENTY OF TIME TO WATCH THIS SYSTEM AND PLENTY OF TIME FOR MODELS TO FINE TUNE TRACK/INTENSITY/TIMING OF THIS WAVE...BUT IT DOES LOOK TO BE A SYSTEM TO WATCH. VERY ACTIVE PATTERN LOOKS TO CONTINUE INTO NEXT WEEK WITH QUICK SHOT OF COOLER AIR BEHIND THE SUNDAY NIGHT/MONDAY MORNING CLIPPER FOLLOWED QUICKLY BE WARM AIR ADVECTION AHEAD OF YET ANOTHER SYSTEM SLATED TO ARRIVE TOWARD MID-WEEK. IZZI && .AVIATION... FOR THE 18Z TAFS... TRICKY FORECAST WITH LOW CONFIDENCE IN EXACT DETAILS...ESPECIALLY FOR THIS AFTERNOON AND TONIGHT. SOUTHERLY WINDS HAVE STRUGGLED WITH GUSTS MAINLY IN THE LOW 20 KT RANGE. LOWERED GUSTS THROUGH THE PERIOD BECAUSE IT SEEMS LIKE THE THICK CLOUD COVER IS LIMITING MIXING. HOWEVER...ANY BREAKS IN THE CLOUDS SEEM TO HELP GUSTS GET UP TO 30 KT. OCNL GUSTS TO 30 KT CANNOT BE RULED OUT THIS AFTN. HAVE LOW CONFIDENCE IN SHOWER AND THUNDERSTORM COVERAGE THIS AFTERNOON. KEPT -SHRA AND VCTS IN THE TAFS AFT 21Z AS PRIME TIME HEATING WILL HELP SHOWERS TO FORM. THINKING BETTER TS COVERAGE WILL BE SOUTH OF THE TERMINALS. SHOWERS INCREASE IN COVERAGE THIS EVENING BUT STILL HAVE LOW CONFIDENCE IN THUNDER OCCURRENCE AND COVERAGE. THINKING THE BEST CHANCE FOR THUNDER OVERNIGHT WILL BE AT RFD WHERE DYING STORMS OVER IOWA WILL SHIFT EAST THROUGH THE LATE EVENING. HAVE LOW CONFIDENCE IN TSRA TIMING THOUGH. KEPT IFR CIGS IN THE FORECAST AS GUIDANCE IS STILL SUGGESTING THEY WILL OCCUR. IFR CIGS ARE CURRENTLY TIED TO THE LOW OVER THE PLAINS...BUT CAN SEE CIGS DROPPING TO AT LEAST MVFR AS WE SATURATE OVERNIGHT. MIXING PICKS UP QUICKLY THURSDAY AS THE LOW ENTERS THE REGION. THINKING THE MIXING WILL HELP LIFT CIGS QUICKLY. SOUTHWEST WINDS COULD GUST HIGHER THAN FORECAST...BUT DID NOT WANT TO INCLUDE WINDS AS STRONG AS MODELS SUGGEST JUST YET. ONE MODEL FEATURES GUSTS OVER 45 KT. THINKING RAIN SHIFTS EAST IN THE MORNING...BUT A NEW ROUND OF SHOWERS AND STORMS FORMS ALONG THE LOW/S COLD FRONT IN THE LATE MORNING/EARLY AFTN. SOME OF THESE STORMS COULD BE SEVERE OVER THE EASTERN TERMINALS. WINDS BECOME WEST AND THEN NORTHWEST BEHIND THE FRONT. JEE && .MARINE... 309 AM CDT SOUTHERLY WINDS/GUSTS ARE INCREASING OVER THE LAKE EARLY THIS MORNING AS THE GRADIENT BECOMES MORE ORGANIZED WITH DEVELOPING LOW PRESSURE OVER THE CENTRAL PLAINS. THIS LOW WILL DEEPEN TODAY INTO THURSDAY AS IT APPROACHES AND THEN MOVES OVER LAKE MICHIGAN. EXPECT SOUTHERLY WINDS TO RAMP UP TO 30KT LATER TODAY WITH A FEW GALE FORCE GUSTS STILL POSSIBLE OVER THE NORTHERN PART OF THE LAKE. HOWEVER...STABILITY OVER THE LAKE WILL HELP TO LIMIT ANY PREVAILING GALES. WINDS OVER THE NEARSHORE WILL ALSO RAMP UP TO 30KT TODAY...WITH SPEEDS EXPECTED TO REMAIN BELOW GALES DURING THIS TIME. AS THE SURFACE TROUGH AXIS WITH THIS LOW MOVES OVER THE CENTRAL PART OF THE LAKE LATER TONIGHT...OVERALL SPEEDS ACROSS THE LAKE WILL DIMINISH. THIS WONT LIKELY BE THE CASE THOUGH OVER THE SOUTHERN HALF OF THE LAKE AND NEARSHORE WATERS WITH SPEEDS EXPECTED TO REMAIN ELEVATED. OVER THE OPEN WATERS...STABILITY WILL CONTINUE TO LIMIT ANY GALES. WINDS/GUSTS WILL STILL BE TO 30KT WITH SOME POTENTIAL FOR GALES OVERNIGHT ACROSS THE NEARSHORE WATERS THOUGH. DO THINK ANY GALE POTENTIAL WILL BE SPORADIC...AND SO HAVE ONLY MENTION OF GALE FORCE GUSTS. WINDS ARE EXPECTED TO STILL VARY GREATLY OVER THE LAKE ON THURSDAY WITH THIS LOW MOVING OVERHEAD. OVER THE NORTH HALF...NORTHERLY WINDS TO 30 KT WILL OCCUR AND OVER THE SOUTH HALF...SOUTH SOUTHWEST WINDS TO 30 KT WILL BE IN PLACE. SOME LOWER CONFIDENCE WITH HOW THIS SYSTEM WILL EVOLVE ON THURSDAY BUT THERE IS SOME HIGHER POTENTIAL FOR GALES ACROSS THE NEARSHORE. HIGHEST CHANCES LOOK TO BE EAST OF NORTHERLY ISLAND...AND SO HAVE REPLACED THE SMALL CRAFT ADVISORY WITH A GALE WATCH ON THURSDAY FOR AREAS EAST OF NORTHERLY ISLAND. AS THIS LOW EXITS THURSDAY NIGHT...WINDS WILL TURN TO THE NORTH/NORTHWEST WHILE DIMINISHING. A PERIOD OF SLIGHTLY LOWER SPEEDS IS EXPECTED ON FRIDAY BUT WITH ANOTHER AREA OF LOW PRESSURE EXPECTED TO STRENGTHEN AS IT MOVES THROUGH THE GREAT LAKES REGION...STRONGER WINDS APPROACHING GALES WILL BE ONCE AGAIN POSSIBLE THIS WEEKEND. RODRIGUEZ && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 10 AM THURSDAY. GALE WATCH...LMZ742-LMZ743-LMZ744-LMZ745...10 AM THURSDAY TO 7 PM THURSDAY. SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 9 PM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1253 PM CDT WED MAR 30 2016 .UPDATE... Issued at 1045 AM CDT Wed Mar 30 2016 Forecast is pretty much on track today with scatteres showers and a few thunderstorms spreading ne across areas from I-55 west at lat this morning. Had pea size hail (1/4 inch) recently reported in Springfield with a thunderstorm. Most of the lightning activity is currently in eastern Sangamon county, and there was some lightning in past hour near Tazewell and Logan county border. 15Z surface map shows 998 mb low pressure over central Nebraska with a cold front through central KS into nw Texas/OK. Breezy sse winds of 12-20 mph and gusts of 20-30 mph over central IL this morning. 1030 am temps were in the low to mid 50s with dewpoints in the mid to upper 30s. RAP, HRRR and NAM models show scattered showers along with chances of thunderstorms spreading over eastern IL during the afternoon. SPC has marginal risk of severe storms for areas from highway 51 west this afternoon into tonight, with 5-15% risk of hail and high winds and just 2% risk of tornadoes. RAP and NAM show low MUCAPES peaking from 200-400 j/kg over western CWA today while high shear of 45-60 kts in western CWA with highest shear nw of IL river. Better chance of severe storms is west of IL this afternoon/tonight where stronger instability/higher CAPES. Highs this afternoon in the low to mid 60s with upper 60s southeast of I-70 and from Jacksonville sw. && .SHORT TERM...(Today) ISSUED AT 300 AM CDT Wed Mar 30 2016 The recent stretch of quiet weather across central and southeast Illinois will come to an end today as a slow moving storm system approaches the area. The upper-level low driving the system is still spinning across the southwest U.S., but it is expected to translate into the central High Plains by this evening as it begins to open up and become absorbed into a digging northern stream trof. Strong southerly flow ahead of the system will transport moisture into the initially very dry airmass across the forecast area this morning. This moisture will be acted on by a lead short wave ejecting out of the southwest system, and associated enhanced WAA/isentropic ascent. The stronger winds aloft will help minimize surface based instability today, but fairly steep mid-level lapse rates will still support elevated convection. Expect numerous showers and scattered thunderstorms to break out from late morning into the afternoon hours as the forcing moves in and the atmosphere has time to moisten. The elevated warm layer will keep winds from getting as strong today as they might otherwise be, but the surface gradient and potential mixing still support gusts over 30 mph by afternoon. The strong southerly winds, aside from transporting moisture into the area, will also boost temperatures well above normal. Despite the increasing clouds and precipitation threat, expect afternoon highs to top out well into the 60s. A few 70s are possible as well. .LONG TERM...(Tonight through Tuesday) ISSUED AT 300 AM CDT Wed Mar 30 2016 Large upper low along the Utah/Nevada borer expected to contract as it moves east today, reaching the northeast corner of Colorado this evening before it starts to get drawn into the trough dropping across Manitoba/western Ontario. Secondary trough expected to drop southeast from the Dakotas on Thursday as a broad trough digs southward from Ontario. These will be the main players over the next couple days in terms of rain chances over our area. Despite very high PoP`s over the area tonight, none of the models are indicating a solid, continuous rain shield, although areas south of I-70 would see the best odds of this happening as a cluster of stronger thunderstorms tracks along the lower Ohio River. Thus, precipitation will be covered with "occasional" wording. Best thunder chances will be west of highway 51 as CAPE`s rise to 500- 1000 J/kg. As the storm system has been slowing down in recent model runs, have made some significant adjustments to PoP`s on Thursday and increased them to 50-60% along and east of I-57 around midday and early afternoon. Latest SPC Day2 outlook introduced a slight risk of severe storms from about Danville-Effingham eastward, as CAPE`s rise to around 1500 J/kg and 0-6km bulk shear ramps up to around 60-70 knots. Leaned more toward the GFS timing, which has the surface front exiting the southeast CWA by late afternoon. With the slower frontal passage, have increased highs by several degrees Thursday, with most areas east of I-55 reaching around 70 degrees. Made little change to PoP`s for late Thursday night and Friday, as the secondary trough swings through the area. As it exits, the upper pattern will continue to focus a strong northwest flow into the Midwest, although the colder air will provide more of a glancing blow. Saturday night looks to be the best chance of temperatures near or below freezing, as an area of high pressure sinks southeast toward the Ohio Valley. However, a secondary surge of cooler air is progged to swing through Monday night. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 1255 PM CDT Wed Mar 30 2016 A cluster of showers and thunderstorms east of the IL to along I-57 is tracking ne around 50 mph and will affect most of the central IL airports this afternoon. MVFR ceilings and vsbys likely with thunderstorms and vsbys could briefly drop below 2 miles as SPI was as low as 1/2 mile with small hail. Most of these thunderstorms pass se of PIA next few hours and introduced thunderstorm chances at PIA during mid/late afternoon. 998 mb low pressure over south central Nebraska early this afternoon will track ne to near the WI/IL border by 18Z/Thu and pull a cold front east toward the IL river by early Thu afternoon. More thunderstorms will likely occur tonight and develop along and ahead of this cold front by early Thu afternoon and track into eastern IL during mid/late Thu afternoon, just after the 24 hour TAF window. Breezy SSW winds of 15-20 kts and gusts of 25-30 kts will occur next 24 hours ahead of this cold front, with strongest winds during the afternoon and again during day on Thu. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...07 SHORT TERM...BAK LONG TERM...Geelhart AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE, IL
1136 AM CDT WED MAR 30 2016 .UPDATE... 1134 AM CDT WIDELY SCATTERED SHOWERS HAVE DEVELOPED OVER PORTIONS OF NORTHEASTERN ILLINOIS ALONG THE LEADING EDGE OF THE BETTER MOISTURE TRANSPORT. ADDITIONAL SHOWERS...AND THUNDERSTORMS WILL LIKELY CONTINUE TO DEVELOP INTO CENTRAL PORTIONS OF THE STATE INTO THE EARLY AFTERNOON...AND SOME OF THESE STORMS WILL LIKELY SHIFT ACROSS SOME OF MY SOUTHERN COUNTIES THROUGH EARLY AFTERNOON. ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS ALSO LOOK TO DEVELOP THIS AFTERNOON AND IMPACT THE AREA BY MID TO LATE AFTERNOON. THE SEVERE THREAT WITH THESE STORM LOOKS LOW. THE MAIN CONCERN FOR SEVERE THUNDERSTORMS WILL BE ON THURSDAY. MODEL GUIDANCE CONTINUES TO SLOW THE PROGRESSION OF THE SURFACE COLD FRONT OVER THE AREA ON THURSDAY. AS A RESULT...IT APPEARS THE SEVERE WEATHER THREAT WILL ALSO EXTEND INTO EASTERN ILLINOIS AND NORTHWESTERN INDIANA DURING THE LATE MORNING THROUGH AT LEAST THE MID AFTERNOON HOURS...WHICH LOOKS TO INCLUDE AT LEAST PORTIONS OF THE CHICAGO AREA. THIS SLOWER FRONTAL TIMING LOOKS TO ALLOW TEMPERATURES TO WARM WELL INTO THE 60S TO NEAR 70 WITHIN THE PREFRONTAL AIRMASS...AND THIS IN COMBINATION WITH DEWPOINTS EXPECTED TO BE NEAR 60 BENEATH A CORRIDOR OF STEEPENING MID-LEVEL LAPSE RATES...MLCAPE VALUES IN EXCESS OF 1000 J/KG APPEAR TO BE VERY POSSIBLE. THE KINEMATIC FIELD OVER THE AREA LOOKS IMPRESSIVE...WITH A MID LEVEL JET (AROUND 500 MB) EXPECTED TO BE NEAR 70 KT...WHICH SHOULD RESULT IN VERY STRONG DEEP LAYER SHEAR. A MAINLY UNIDIRECTIONAL SHEAR PROFILE SUGGESTS STRONG AND DAMAGING WINDS WILL BE GOOD THREAT WITH THESE STORMS. HOWEVER...THERE COULD ALSO BE DECENT THREATS OF LARGE HAIL GIVEN THE GOOD POTENTIAL FOR SUPER CELL STORM STRUCTURES. KJB && .SHORT TERM... 331 AM CDT THROUGH THURSDAY... DEEPENING LOW PRESSURE OVER THE CENTRAL HIGH PLAINS IS RESULTING IN GRADUALLY INCREASING SOUTHERLY WINDS AND RELATIVELY MILD EARLY MORNING TEMPERATURES. EXTENSIVE MID-HIGH LEVEL CLOUDINESS HAS OVERSPREAD THE AREA AND EXPECT MAINLY JUST SOME FILTERED SUNSHINE IF ANY AT ALL TODAY...HOWEVER STRENGTHENING SOUTHERLY WINDS/WARM AIR ADVECTION SHOULD ALLOW TEMPS TO CLIMB INTO THE UPPER 50S NORTH TO LOW-MID 60S SOUTH TODAY. LOW LEVEL MOISTURE WILL INITIALLY BE SCANT TODAY...HOWEVER STRONG MOISTURE ADVECTION IN THE 850-700 MB LEVEL BENEATH FAIRLY STEEP MID LEVEL LAPSE RATES WILL RESULT IN SOME MODEST ELEVATED INSTABILITY WHICH SHOULD SUPPORT SOME WIDELY SCATTERED HIGH BASED SHOWERS AND PERHAPS A THUNDERSTORM TODAY...PARTICULARLY THIS AFTERNOON. THERE SHOULD BE MANY DRY HOURS TODAY...IN FACT THE MAJORITY OF THE DAY SHOULD BE WINDY...MILD...AND RAIN FREE...BUT HAVE AN UMBRELLA HANDY AS THERE WILL PROBABLY BE SOME SPLASH AND DASH SHOWERS AROUND. THE MOST WIDESPREAD AND PERSISTENT SHOWER AND T-STORM ACTIVITY TONIGHT WILL LIKELY BE NEAR, IF NOT NORTH OF, THE WI BORDER TO THE NORTH OF THE SFC WARM FRONT. HOWEVER, MODEST INSTABILITY AND BROAD LARGE SCALE ASCENT...ALONG WITH ANY REMNANT ACTIVITY ROLLING IN FROM THE WEST WILL RESULT IN AT LEAST SOME OCCASIONAL SHOWERS AND T-STORMS TONIGHT. DEFINITELY NOT LOOKING LIKE A WASH-OUT...BUT HARD TO ARGUE WITH CATEGORICAL POPS BEING OFFERED UP BY GUIDANCE TONIGHT. IT WILL REMAIN WINDY...UNSEASONABLY WARM...AND RATHER HUMID TONIGHT WITH TEMPERATURES PROBABLY HOLDING NEAR IF NOT IN THE LOWER 60S. MODELS HAVE TRENDED A BIT SLOWER STILL WITH PROGRESSION OF THIS SYSTEM ON THURSDAY...WHICH NOW MEANS MOST OF THE CWA WILL START OUT IN THE WARM SECTOR FIRST THING IN THE MORNING. NAM CONTINUES TO BE AN OUTLIER WITH STRONGER SHORTWAVE HANGING BACK IN THE MEAN TROUGH AND RESULTING IN STRONGER SECONDARY CYCLOGENESIS OVER MO MIDDAY AND PAINTING A MUCH MORE OMINOUS SEVERE WEATHER THREAT OVER ESPECIALLY EASTERN COUNTIES. GFS/ECMWF ARE QUICKER WITH THE SECONDARY SHORTWAVE AND HAVE MORE UNFAVORABLE TIMING AND WOULD LEAD TO GREATER THREAT OF CONVECTIVE RE-DEVELOPMENT AND SUBSEQUENT SEVERE THREAT FARTHER EAST INTO IN. GIVEN THE RECENT SLOWING TREND WILL NEED TO KEEP AN EYE ON LATER MODEL RUNS FOR A POTENTIAL GREAT SEVERE WX THREAT LOCALLY THURSDAY. THE UNSEASONABLY WARM START TO THE DAY SHOULD SET THE STAGE FOR A VERY WARM DAY AHEAD OF THE FRONT WITH HIGHS INTO THE 70S OVER SE CWA WHERE FROPA LOOKS TO BE MIDDAY AT THE EARLIEST. IN THE WAKE OF THE COLD FRONT LOOK FOR FALLING TEMPERATURES DURING THE DAY AND THE POTENTIAL FOR VERY STRONG WINDS. TRACK OF THE SURFACE LOW REMAINS A BIT UNCERTAIN...BUT A MORE NORTHERLY TRACK LIKE THE GFS COULD PUT A LARGE PORTION OF OUR CWA FLIRTING WITH POST-FRONTAL WINDS NEAR ADVISORY CRITERIA. IZZI && .LONG TERM... 331 AM CDT FRIDAY THROUGH WEDNESDAY... SUBTLE NW FLOW SHORTWAVE IS PROGGED TO MOVE ACROSS THE REGION FRIDAY AND WHEN COMBINED WITH COLD AIR ALOFT AND STEEP LAPSE RATES SHOULD SUPPORT AT LEAST WIDELY SCATTERED SHOWERS DURING THE AFTERNOON. GIVEN THE LOW FREEZING LEVELS AND A STEEP LAPSE RATES ITS POSSIBLE THAT THE MORE VIGOROUS SHOWERS COULD HAVE SOME GRAUPEL (MUSHY HAIL) OR PERHAPS EVEN A WET SNOWFLAKE OR TWO. MUCH MORE VIGOROUS CLIPPER-LIKE SYSTEM IS PROGGED TO DROP SOUTHEAST INTO THE GREAT LAKES REGION SATURDAY. SURFACE LOW SHOULD TRACK NORTH OF OUR AREA PUTTING US ON THE DRY SIDE OF THE SYSTEM WITH LITTLE/NO PRECIP EXPECTED...HOWEVER LATE SEASON ARCTIC FRONT IS PROGGED TO MOVE THROUGH DURING THE AFTERNOON BRINGING COLDER TEMPERATURES BUT MORE NOTICEABLY A PERIOD OF STRONG NORTHWEST WINDS. COLD AIR BEHIND THE FRONT SHOULD BE SHORT LIVED AS ANOTHER STRONG CLIPPER TRACK SOUTHEAST INTO THE REGION SUNDAY NIGHT WITH WARM AIR ADVECTION IN ADVANCE OF THIS CLIPPER COMMENCING SUNDAY AFTERNOON. LATEST GFS/ECMWF TRACK THIS SYSTEM FAR ENOUGH NORTH TO SUPPORT ALL RAIN FOR OUR CWA...AND IF IT TRACKS MUCH FARTHER NORTH WE COULD STAY DRY ALTOGETHER. DID MAINTAIN A RAIN/SNOW CHANCE SUNDAY NIGHT AS A SOUTHWARD SHIFT IN THE FORECAST TRACK OF THE SYSTEM COULD PUT US CLOSER TO THE RAIN-SNOW LINE. SYSTEM IS PROGGED TO BE RATHER VIGOROUS WITH STRONG ASCENT IN THE RIGHT ENTRANCE REGION OF >100KT 250MB JET ACCOMPANIED BY STEEP MID-LEVEL LAPSE RATES...SO COULD EVEN SOME SOME CONVECTIVE ELEMENTS TO THE PRECIP. PLENTY OF TIME TO WATCH THIS SYSTEM AND PLENTY OF TIME FOR MODELS TO FINE TUNE TRACK/INTENSITY/TIMING OF THIS WAVE...BUT IT DOES LOOK TO BE A SYSTEM TO WATCH. VERY ACTIVE PATTERN LOOKS TO CONTINUE INTO NEXT WEEK WITH QUICK SHOT OF COOLER AIR BEHIND THE SUNDAY NIGHT/MONDAY MORNING CLIPPER FOLLOWED QUICKLY BE WARM AIR ADVECTION AHEAD OF YET ANOTHER SYSTEM SLATED TO ARRIVE TOWARD MID-WEEK. IZZI && .AVIATION... FOR THE 12Z TAFS... MAIN FORECAST CONCERNS/CHALLENGES WILL BE WITH SHOWER/THUNDER CHANCES TODAY AND TONIGHT...WITH THE HIGHER CHANCES FOR SHOWERS AND THUNDER NOT ARRIVING UNTIL LATER THIS AFTERNOON INTO THE EVENING. PRECIP DEVELOPMENT IS CURRENTLY WEST AND NORTHWEST OF THE TERMINALS WITH THIS DEVELOPMENT EXPECTED TO STAY AWAY FROM THE TERMINALS THIS MORNING...WITH ANY ADDITIONAL UPSTREAM DEVELOPMENT TO THE SOUTHWEST LIKELY NOT ARRIVING UNTIL LATER IN THE DAY. BASED ON LATEST TRENDS...DID PUSH BACK THE ARRIVAL OF PRECIP TO THE TERMINALS BUT COULD SEE THIS PUSHED BACK EVEN FURTHER INTO THE AFTERNOON. IF THIS TREND WERE TO CONTINUE THEN THE BULK OF TODAY COULD STAY DRY UNTIL LATE THIS AFTERNOON WHEN BETTER FORCING AND SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARRIVE. SURFACE LOW AND FRONTAL BOUNDARY TO THE WEST WILL APPROACH THE TERMINALS LATER THIS EVENING AND OVERNIGHT...WHEN HIGHER CHANCES FOR PREVAILING SHOWERS AND THUNDERSTORMS WILL OCCUR. HAVE HIGHER CONFIDENCE WITH THE TIMES OF HIGHEST POTENTIAL FOR PRECIP BUT WITH LOWER CONFIDENCE STILL IN PLACE WITH OVERALL DURATION...AS ITS POSSIBLE THAT EVEN THIS EVENING COULD SEE PERIODIC DRY CONDITIONS. SHOWERS WILL THEN LIKELY PERSIST FOR MOST OF TONIGHT WITH EVEN SCATTERED THUNDER STILL REMAINING A POSSIBILITY...ALTHOUGH NOT CURRENTLY CONVEYED IN THE TAFS GIVEN LOWER CONFIDENCE. VFR CEILINGS WILL BE IN PLACE FOR MOST OF TODAY BUT WITH CEILINGS EXPECTED TO LOWER LATER THIS AFTERNOON AND MORE SO THIS EVENING AND OVERNIGHT. HAVE HIGH CONFIDENCE WITH LOW END MVFR CEILINGS LATER THIS EVENING WITH CONFIDENCE GROWING ON THE POTENTIAL FOR IFR CEILINGS...AND HAVE INCLUDED THIS IN THE TAFS. GUSTY SOUTHERLY WINDS STILL ANTICIPATED TODAY AND TONIGHT...WITH THESE STRONGER WINDS LIKELY TO PERSIST THURSDAY MORNING. RODRIGUEZ && .MARINE... 309 AM CDT SOUTHERLY WINDS/GUSTS ARE INCREASING OVER THE LAKE EARLY THIS MORNING AS THE GRADIENT BECOMES MORE ORGANIZED WITH DEVELOPING LOW PRESSURE OVER THE CENTRAL PLAINS. THIS LOW WILL DEEPEN TODAY INTO THURSDAY AS IT APPROACHES AND THEN MOVES OVER LAKE MICHIGAN. EXPECT SOUTHERLY WINDS TO RAMP UP TO 30KT LATER TODAY WITH A FEW GALE FORCE GUSTS STILL POSSIBLE OVER THE NORTHERN PART OF THE LAKE. HOWEVER...STABILITY OVER THE LAKE WILL HELP TO LIMIT ANY PREVAILING GALES. WINDS OVER THE NEARSHORE WILL ALSO RAMP UP TO 30KT TODAY...WITH SPEEDS EXPECTED TO REMAIN BELOW GALES DURING THIS TIME. AS THE SURFACE TROUGH AXIS WITH THIS LOW MOVES OVER THE CENTRAL PART OF THE LAKE LATER TONIGHT...OVERALL SPEEDS ACROSS THE LAKE WILL DIMINISH. THIS WONT LIKELY BE THE CASE THOUGH OVER THE SOUTHERN HALF OF THE LAKE AND NEARSHORE WATERS WITH SPEEDS EXPECTED TO REMAIN ELEVATED. OVER THE OPEN WATERS...STABILITY WILL CONTINUE TO LIMIT ANY GALES. WINDS/GUSTS WILL STILL BE TO 30KT WITH SOME POTENTIAL FOR GALES OVERNIGHT ACROSS THE NEARSHORE WATERS THOUGH. DO THINK ANY GALE POTENTIAL WILL BE SPORADIC...AND SO HAVE ONLY MENTION OF GALE FORCE GUSTS. WINDS ARE EXPECTED TO STILL VARY GREATLY OVER THE LAKE ON THURSDAY WITH THIS LOW MOVING OVERHEAD. OVER THE NORTH HALF...NORTHERLY WINDS TO 30 KT WILL OCCUR AND OVER THE SOUTH HALF...SOUTH SOUTHWEST WINDS TO 30 KT WILL BE IN PLACE. SOME LOWER CONFIDENCE WITH HOW THIS SYSTEM WILL EVOLVE ON THURSDAY BUT THERE IS SOME HIGHER POTENTIAL FOR GALES ACROSS THE NEARSHORE. HIGHEST CHANCES LOOK TO BE EAST OF NORTHERLY ISLAND...AND SO HAVE REPLACED THE SMALL CRAFT ADVISORY WITH A GALE WATCH ON THURSDAY FOR AREAS EAST OF NORTHERLY ISLAND. AS THIS LOW EXITS THURSDAY NIGHT...WINDS WILL TURN TO THE NORTH/NORTHWEST WHILE DIMINISHING. A PERIOD OF SLIGHTLY LOWER SPEEDS IS EXPECTED ON FRIDAY BUT WITH ANOTHER AREA OF LOW PRESSURE EXPECTED TO STRENGTHEN AS IT MOVES THROUGH THE GREAT LAKES REGION...STRONGER WINDS APPROACHING GALES WILL BE ONCE AGAIN POSSIBLE THIS WEEKEND. RODRIGUEZ && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 10 AM THURSDAY. GALE WATCH...LMZ742-LMZ743-LMZ744-LMZ745...10 AM THURSDAY TO 7 PM THURSDAY. SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 9 PM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1046 AM CDT WED MAR 30 2016 .UPDATE... Issued at 1045 AM CDT Wed Mar 30 2016 Forecast is pretty much on track today with scatteres showers and a few thunderstorms spreading ne across areas from I-55 west at lat this morning. Had pea size hail (1/4 inch) recently reported in Springfield with a thunderstorm. Most of the lightning activity is currently in eastern Sangamon county, and there was some lightning in past hour near Tazewell and Logan county border. 15Z surface map shows 998 mb low pressure over central Nebraska with a cold front through central KS into nw Texas/OK. Breezy sse winds of 12-20 mph and gusts of 20-30 mph over central IL this morning. 1030 am temps were in the low to mid 50s with dewpoints in the mid to upper 30s. RAP, HRRR and NAM models show scattered showers along with chances of thunderstorms spreading over eastern IL during the afternoon. SPC has marginal risk of severe storms for areas from highway 51 west this afternoon into tonight, with 5-15% risk of hail and high winds and just 2% risk of tornadoes. RAP and NAM show low MUCAPES peaking from 200-400 j/kg over western CWA today while high shear of 45-60 kts in western CWA with highest shear nw of IL river. Better chance of severe storms is west of IL this afternoon/tonight where stronger instability/higher CAPES. Highs this afternoon in the low to mid 60s with upper 60s southeast of I-70 and from Jacksonville sw. && .SHORT TERM...(Today) ISSUED AT 300 AM CDT Wed Mar 30 2016 The recent stretch of quiet weather across central and southeast Illinois will come to an end today as a slow moving storm system approaches the area. The upper-level low driving the system is still spinning across the southwest U.S., but it is expected to translate into the central High Plains by this evening as it begins to open up and become absorbed into a digging northern stream trof. Strong southerly flow ahead of the system will transport moisture into the initially very dry airmass across the forecast area this morning. This moisture will be acted on by a lead short wave ejecting out of the southwest system, and associated enhanced WAA/isentropic ascent. The stronger winds aloft will help minimize surface based instability today, but fairly steep mid-level lapse rates will still support elevated convection. Expect numerous showers and scattered thunderstorms to break out from late morning into the afternoon hours as the forcing moves in and the atmosphere has time to moisten. The elevated warm layer will keep winds from getting as strong today as they might otherwise be, but the surface gradient and potential mixing still support gusts over 30 mph by afternoon. The strong southerly winds, aside from transporting moisture into the area, will also boost temperatures well above normal. Despite the increasing clouds and precipitation threat, expect afternoon highs to top out well into the 60s. A few 70s are possible as well. .LONG TERM...(Tonight through Tuesday) ISSUED AT 300 AM CDT Wed Mar 30 2016 Large upper low along the Utah/Nevada borer expected to contract as it moves east today, reaching the northeast corner of Colorado this evening before it starts to get drawn into the trough dropping across Manitoba/western Ontario. Secondary trough expected to drop southeast from the Dakotas on Thursday as a broad trough digs southward from Ontario. These will be the main players over the next couple days in terms of rain chances over our area. Despite very high PoP`s over the area tonight, none of the models are indicating a solid, continuous rain shield, although areas south of I-70 would see the best odds of this happening as a cluster of stronger thunderstorms tracks along the lower Ohio River. Thus, precipitation will be covered with "occasional" wording. Best thunder chances will be west of highway 51 as CAPE`s rise to 500- 1000 J/kg. As the storm system has been slowing down in recent model runs, have made some significant adjustments to PoP`s on Thursday and increased them to 50-60% along and east of I-57 around midday and early afternoon. Latest SPC Day2 outlook introduced a slight risk of severe storms from about Danville-Effingham eastward, as CAPE`s rise to around 1500 J/kg and 0-6km bulk shear ramps up to around 60-70 knots. Leaned more toward the GFS timing, which has the surface front exiting the southeast CWA by late afternoon. With the slower frontal passage, have increased highs by several degrees Thursday, with most areas east of I-55 reaching around 70 degrees. Made little change to PoP`s for late Thursday night and Friday, as the secondary trough swings through the area. As it exits, the upper pattern will continue to focus a strong northwest flow into the Midwest, although the colder air will provide more of a glancing blow. Saturday night looks to be the best chance of temperatures near or below freezing, as an area of high pressure sinks southeast toward the Ohio Valley. However, a secondary surge of cooler air is progged to swing through Monday night. && .AVIATION...(For the 12Z TAFS through 12Z Thursday morning) Issued at 647 AM CDT Wed Mar 30 2016 LLWS is present to start the day across the central Illinois terminals. However, within the next couple of hours, some of the stronger winds aloft will mix down, with gusty southerly surface winds persisting through the rest of the 12Z TAF valid time. VFR conditions will degrade to MVFR, and possibly IFR by tonight, as showers and thunderstorms become more numerous with the approach of a storm system. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...07 SHORT TERM...BAK LONG TERM...Geelhart AVIATION...BAK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
430 PM CDT WED MAR 30 2016 .SHORT TERM /TONIGHT/... ISSUED AT 430 PM CDT WED MAR 30 2016 SHORT TERM...TONIGHT...FOCUS CONTINUES TO BE ON SEVERE WEATHER POTENTIAL OVER THE SOUTHERN HALF OF THE FORECAST AREA THROUGH THE EARLY EVENING HOURS. WARM FRONT HAS SURGED NORTHWARD THROUGH THE DAY AND STALLED ROUGHLY ALONG A LINE FROM JUST NORTH OF WATERLOO WEST- SOUTHWEST THROUGH SOUTH OF DENISON. SURFACE DEW POINTS HAVE INCREASED TO THE MIDDLE 50S TO LOWER 60S IN THE SOUTHWEST CORNER OF THE STATE. SOME CLEARING EVIDENT ON 2015Z VISIBLE SATELLITE AND SPC MESOSCALE ANALYSIS AS WELL AS THE 30.20Z RUC SUGGEST SURFACE BASE CAPE BETWEEN 700-1100 J/KG. WEAK CONVERGENCE PRESENT ALONG THE COLD FRONT HAS ALREADY SPAWNED A FEW ELEVATED STORMS OVER CRAWFORD/CARROLL COUNTY AREA...BUT CAP IS STRONG ENOUGH TO KEEP THEM FROM DEVELOPING ANY FURTHER. THE AREA OF CONCERN IS OVER THE SOUTHWEST PORTION OF THE CWA THROUGH 02Z...BUT CHANCES QUICKLY WANE AS THE SUN SETS. EFFECTIVE SHEAR AND EVEN DEEP LAYER SHEAR IS REASONABLE FOR SUSTAINING THUNDERSTORM UPDRAFTS...BUT THE 0-1KM IS WEAK AND HAVE LOW CONFIDENCE WITH TORNADIC THREAT. THE MAIN CONCERN LOOKS TO BE HAIL AND EVEN WIND DAMAGE POTENTIAL ALONG AND SOUTH OF HIGHWAY 34 TO THE MISSOURI BORDER. ONCE THE COLD FRONT MOVES THROUGH LATE TONIGHT INTO THE OVERNIGHT HOURS...CAA SHOWER ACTIVITY LOOKS TO DEVELOP AND HAVE HIGHER POPS ACROSS THE NORTH BETWEEN 06-12Z THURSDAY. .LONG TERM /THURSDAY THROUGH WEDNESDAY/... ISSUED AT 430 PM CDT WED MAR 30 2016 THURSDAY WILL REPRESENT A TRANSITION PERIOD WITH PRECIPITATION DECREASING IN THE MORNING THE INCREASING CHANCES LATER IN THE DAY AND OVERNIGHT AS A STRONG SHORT WAVE DROPS OUT OF THE NORTHWEST FLOW. A TROUGH OF LOW PRESSURE WILL DEVELOP OVER THE UPPER MIDWEST THURSDAY NIGHT INTO FRIDAY. THERE WILL BE SOME CHANCES FOR SNOW AS THIS SYSTEM MOVES INTO THE AREA. SNOW CHANCES WILL HINGE ON LOW LEVEL WET BULB TEMPERATURES AND SHOULD HAVE RAIN TRANSITIONING TO SNOW FROM NORTHWEST TO SOUTHEAST. MAY HAVE SNOW FLAKES REACH INTO SOUTHERN IOWA. POSSIBLE FOR SOME MINOR ACCUMULATIONS ON GRASSY AREAS THAT WILL NOT LAST LONG. THE UPPER TROUGH WILL BEGIN TO SHIFT EAST BY LATE SATURDAY INTO SUNDAY WITH WARMER TEMPERATURES ARRIVING FOR SUNDAY WITH HIGHS BACK IN THE 60S. ANOTHER PUSH FOR COLDER AIR ARRIVES ON MONDAY WITH TEMPERATURES DROPPING BACK INTO THE 40S AND 50S FOLLOWED BY MORE MILD CONDITIONS TO END THE PERIOD. THE GROWING SEASON CONTINUES TO CREEP NORTH INTO SOUTHERN IOWA. CERTAINLY READINGS WILL DROP NEAR TO BELOW FREEZING AT TIMES...ESPECIALLY FRIDAY NIGHT...SATURDAY NIGHT AND MONDAY NIGHT. POSSIBLE HEADLINES MAY BE CONSIDERED AT THAT TIME. && .AVIATION...30/18Z ISSUED AT 1241 PM CDT WED MAR 30 2016 MVFR CIGS WILL CONTINUE NORTH OF THE WARM FRONT OVER FOD/MCW AND POSSIBLY AT ALO. THE LATEST HRRR AND 4KM WRF DEPICTS CONVECTION MOVING ACROSS THE STATE B/T 23Z TO 04Z FROM SOUTHWEST TO EAST- CENTRAL IOWA. CERTAINLY CAN EXPECT SOME BRIEF IFR AND EVEN LIFR VIS/CIGS IF CONVECTION ROLLS OVER AN AIRPORT...BUT LOW CONFIDENCE IN MENTIONING DUE TO THE SHORT DURATION AND UNCERTAINTY IN INITIATION. ONCE THE COLD FRONT MOVES THROUGH LATE TONIGHT...MVFR CIGS LOOKS TO SETTLE IN AND LIKELY TO SEE SOME SCATTERED SHOWERS THROUGH THE END OF THE PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...DONAVON AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1242 PM CDT WED MAR 30 2016 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TODAY/... ISSUED AT 311 AM CDT WED MAR 30 2016 FOCUS TODAY CONTINUES TO BE ON THUNDERSTORM/SEVERE WEATHER CHANCES...WITH A FAIRLY ACTIVE DAY FOR EARLY SPRING EXPECTED. A SMALL AREA OF SHOWERS/THUNDERSTORMS PUSHING OUT OF THE NE CWA...WITH ANOTHER AREA IN NE NEBRASKA MOVING TOWARD THE STATE. THIS ACTIVITY LOCATED ON THE NOSE OF THE THETA-E RIDGE THAT IS EXPECTED TO SHIFT EASTWARD AND PUSH THROUGH NORTH CENTRAL IOWA TOWARD SUNRISE/MID MORNING. THEN EXPECT A RELATIVE LULL IN ACTIVITY TOWARD MID DAY...WITH SOME WEAK ENERGY STILL EJECTING OUT AHEAD OF THE MAIN WAVE LIFTING UP INTO THE AREA. THEREFORE MAY STILL SEE SOME ISOLATED TO SCATTERED SHOWERS/TSRA AROUND MID DAY. CONCERN THEN SHIFTS TO MORE WIDESPREAD ACTIVITY AS THE SFC LOW NEARS THE STATE...WITH THE ASSOCIATED SFC WARM FRONT EXPECTED TO NOSE UP INTO SOUTHERN IOWA BY MID/LATE AFTERNOON. CAP TO ERODE...WITH INSTABILITY IN THE 500-1000 J/KG RANGE ACROSS THE SOUTHERN THIRD OF THE CWA. DECENT LOW LEVEL SHEAR...WITH MORE OF A UNIDIRECTIONAL SHEAR PROFILE...WOULD SUGGEST A SHIFT TO MORE WIND POTENTIAL AS EXPECT STORMS TO BECOME MORE LINEAR AS THE EVENING PROGRESSES AND SFC TROUGH AXIS PUSHES THROUGH THE CWA. STORM INITIATION EXPECTED TOWARD 21-00Z PER SOUNDINGS ACROSS THE SOUTHERN/SOUTHWESTERN CWA. TORNADO THREAT STILL THERE AS WELL WITH THE HIGHER LOW LEVEL SHEAR AROUND 20KTS FOR 0-1KM...ESPECIALLY WITH MORE ISOLATED CELLS THIS AFTERNOON. ONCE SYSTEM SHIFTS MORE TO A LINEAR MODE...GIVEN THE LOW LEVEL SHEAR COULD STILL HAVE SOME QUICK SPIN-UPS ON THE LEADING EDGE OF THE LINE IF STORMS CAN STAY SFC BASED AS THE SUN SETS AND HEATING IS LOST QUICKLY GIVEN IT IS STILL VERY EARLY SPRING. .LONG TERM /TONIGHT THROUGH TUESDAY/... ISSUED AT 311 AM CDT WED MAR 30 2016 ACTIVE WEATHER PATTERN FOR THE NEXT SEVEN DAYS...WITH BULK OF ANY HIGHER END WEATHER THROUGH THIS EVENING. MAIN CONCERNS EARLY IN THE FORECAST WILL BE ONGOING CONVECTION ACROSS THE AREA. MODELS IN GOOD AGREEMENT WITH PLACEMENT OF DUAL LOW TROUGH AT 00Z WITH COLD FRONT BISECTING THE FORECAST AREA FROM NEAR ATLANTIC TO WATERLOO. WITH THE LOCATION OF THE FRONT...THE BETTER CHANCES FOR ONGOING SEVERE WEATHER WILL BE ACROSS THE SOUTHEAST HALF OF THE FORECAST AREA. COMPLICATED MESOSCALE EVOLUTION THIS EVENING...AS BEST SHEAR WILL ARRIVE LATER IN THE EVENING AND LAG THE BETTER INSTABILITY THIS AFTERNOON AND EARLY EVENING. THUS...SEVERE THREAT WILL BE MAXIMIZED PRIOR TO 03Z ACROSS THE SOUTH/SOUTHWEST WITH HIGHER INSTABILITY... AND THEN CONTINUE A LINGERING SEVERE WEATHER THREAT OVER THE FAR SOUTH NEARER THE IA MO BORDER THROUGH 03Z AS SHEAR INCREASES WHILE INSTABILITY DECREASES OVERNIGHT. THE NAM12 AND GFS SUGGEST THAT A SMALL CORRIDOR OF 1000-1500 J/KG MLCAPE WILL BE LIFTED NORTHEAST INTO SOUTHERN IA BY 03Z. 0-3KM FORECAST HELICITY IS 200 M2/S2. THIS MAY SUPPORT A SMALL TOR THREAT IN THE FAR SOUTH BEYOND 00Z AS UPPER LEVEL 0-6KM SHEAR INCREASES AFTER 00Z INTO THE REGION. THOUGH THE UPPER LEVEL WIND FIELDS ARE NOT WELL ALIGNED VERTICALLY FOR A MORE SIGNIFICANT SVR EPISODE...H500/H300 WINDS DO INCREASE TO 55/95 KTS RESPECTIVELY BY 06Z WHICH SHOULD HELP LINGERING SVR THREAT TO 03Z. BEYOND 03Z...EXPECTING MORE GENERAL THUNDER AS BOTH INSTABILITY AND FAVORABLE LAPSE RATES DECREASE THROUGH 12Z. LINGERING WEAK MAINLY ELEVATED CAPE OVER THE SOUTH WILL PROMOTE SCT/ISO THUNDER THROUGH 12Z THURSDAY FAR SOUTH/SOUTHEAST. AS THE LOW PULLS OUT THURSDAY THE LOW/ELONGATED TROUGH DEEPENS SLIGHTLY WITH A DEFORMATION AXIS EXTENDING BACK ACROSS THE REGION THROUGH MIDDAY IN THE EAST. SOME UNCERTAINTY REMAINS WITH THE EXACT POSITION...SO FOR NOW HAVE BROAD BRUSHED POP OVER THE AREA THROUGH 18Z AND WILL LET SUBSEQUENT SHIFTS REFINE POSITION OF AXIS. AS IN PREVIOUS FORECAST PACKAGES...GFS/EURO AND OTHER MED RANGE MODELS AGREE ON RATHER POTENT SMALL UPPER LEVEL FEATURE DROPPING SOUTHEAST INTO THE NORTHERN/THEN CENTRAL PLAINS THURSDAY EVENING AND FRIDAY MORNING...QUICKLY DROPPING INTO THE BROADENING H500 EASTERN CONUS TROUGH THAT WILL BE DEVELOPING IN THE NEXT 36 HOURS. THOUGH THERE ARE SOME DIFFERENCES ON THE AMOUNT OF GENERATED QPF DUE TO GFS/EURO DIFFERENCES IN HANDLING FORCING AS THE FEATURE PASSES THROUGH...CONSENSUS DOES REMAIN ON STRENGTH OF COLD AIR MASS SUPPORTING MIX OF RAIN/SNOW AND ALL LIGHT SNOW OVER THE NORTH LATE THURSDAY NIGHT INTO FRIDAY MORNING. ANOTHER COLD FRONT WILL ACCOMPANY THE SYSTEM WITH COLDER AIR PLOWING INTO THE REGION FOR FRIDAY AND FRIDAY NIGHT. THOUGH SNOW IS NOW IN THE FORECAST...ONLY A DUSTING OF ACCUMULATION AT MOST IS ANTICIPATED. GIVEN THE WARMTH EXPECTED TODAY...AMOUNT OF RAIN ANTICIPATED OVER THE REGION...THE GROUND IS LIKELY TO RETAIN MORE HEAT AND FOR A LONGER PERIOD OF TIME GIVEN THE COMBINATION OF THESE FACTORS. THUS...MOST OF THE LIGHT SNOW WILL MELT ON CONTACT. AFTER HIGHS THURSDAY IN THE MID 40S NORTH TO MID 50S SOUTH...LOWS BY FRIDAY MORNING WILL BRUSH THE 30 MARK NORTH AND IN THE MID 30S SOUTH. AFTER THE CLIPPER SYSTEM RUSHES EAST OF THE REGION FRIDAY ANOTHER WILL DIVE SOUTHEAST ACROSS THE GREAT LAKES SATURDAY WITH YET ANOTHER SUNDAY NIGHT AND MONDAY. THE NET RESULT WILL BE A ROLLER COASTER OF HIGHS IN THE 50S/60S SAT/SUN FALLING BACK INTO THE 40S/50S MONDAY ONLY TO RISE AGAIN TO THE 50S/60S BY TUESDAY OF NEXT WEEK. WITH SUCH FAST MOVING STORMS AMPLIFYING ACROSS THE CENTRAL AND EASTERN CONUS...SOME MODEL DIFFERENCES HAVE RESULTED IN LOWERED FORECAST CONFIDENCE FOR DAYS6/7 AS WE MOVE TOWARD TUES/WED OF NEXT WEEK. WILL NEED TO SORT OUT DETAILS IN THE COMING DAYS. && .AVIATION...30/18Z ISSUED AT 1241 PM CDT WED MAR 30 2016 MVFR CIGS WILL CONTINUE NORTH OF THE WARM FRONT OVER FOD/MCW AND POSSIBLY AT ALO. THE LATEST HRRR AND 4KM WRF DEPICTS CONVECTION MOVING ACROSS THE STATE B/T 23Z TO 04Z FROM SOUTHWEST TO EAST- CENTRAL IOWA. CERTAINLY CAN EXPECT SOME BRIEF IFR AND EVEN LIFR VIS/CIGS IF CONVECTION ROLLS OVER AN AIRPORT...BUT LOW CONFIDENCE IN MENTIONING DUE TO THE SHORT DURATION AND UNCERTAINTY IN INITIATION. ONCE THE COLD FRONT MOVES THROUGH LATE TONIGHT...MVFR CIGS LOOKS TO SETTLE IN AND LIKELY TO SEE SOME SCATTERED SHOWERS THROUGH THE END OF THE PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...BEERENDS LONG TERM...REV AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
230 PM MDT WED MAR 30 2016 .SHORT TERM...(TODAY THROUGH FRIDAY NIGHT) ISSUED AT 301 AM MDT WED MAR 30 2016 AS OF 3 AM CDT...2 AM MDT...SKIES ACROSS THE TRI-STATE REGION ARE GRADUALLY CLEARING FROM SOUTHWEST TO NORTHEAST. TEMPERATURES VARIED DRASTICALLY ACROSS THE REGION WITH LOCATIONS IN EAST COLORADO DIPPING INTO THE UPPER 30S WHILE LOCATIONS EAST OF HIGHWAY 83 REMAIN IN THE LOW 60S. THIS IS THE RESULT OF THE SURFACE LOW PRESSURE PASSING THROUGH THE REGION AND THE WINDS. WINDS ARE SOUTH AT 10-20 MPH...GUSTING TO 30 MPH AHEAD OF THE LOW WHILE WINDS BEHIND THE LOW ARE NORTHWEST AT 5-15 MPH...GUSTING 20 MPH. AS MENTIONED ABOVE...A SURFACE LOW IS CENTERED OVER THE HIGH PLAINS AT THE PRESENT TIME...MOVING EAST. ALOFT...A LARGE LOW PRESSURE SYSTEM HAS CUTOFF FROM THE FLOW AROUND THE FOUR CORNERS REGION. RAPIDLY EVOLVING WEATHER IS ANTICIPATED OVER THE NEXT 36 HOURS ACROSS THE REGION. HAZARDS POSSIBLE DURING THIS TIME INCLUDE STRONG WIND GUSTS...BLOWING DUST...THUNDERSTORMS...SNOW AND ACCUMULATING SNOW. BEGINNING WITH TODAY...A STRONG COLD FRONT WILL PUSH NORTHWEST TO SOUTHEAST ACROSS THE FORECAST AREA BEHIND THE DEPARTING SURFACE LOW PRESSURE. 3 HOUR PRESSURE RISES NEAR/EXCEEDING 9 MB...COUPLED WITH INCREASING WINDS IN THE 0-1 KM LAYER...INDICATE THE POTENTIAL STRONG WIND GUSTS WITH THE FRONTAL SURGE. FORECAST GUSTS UP TO 50 MPH WITH THE FRONT BUT WOULD NOT BE SURPRISED IF A FEW GUSTS TO 55 MPH WERE REALIZED. IN ADDITION...DRY CONDITIONS ACROSS THE REGION LED TO SOME BLOWING DUST LAST EVENING WITH SOME OF THE STRONGER WINDS. THEREFORE...WITH THE WINDS ARRIVING BEFORE ANY PRECIPITATION... PLACED BLOWING DUST INTO THE FORECAST. ON TO THE NEXT CONCERN...RAIN/THUNDERSTORMS THIS AFTERNOON AND EVENING. FORECAST GUIDANCE INDICATES THAT...AS A STRONG SHORTWAVE TROUGH PUNCHES THROUGH THIS AFTERNOON...SHOWER AND THUNDERSTORM DEVELOPMENT IS LIKELY. DEVELOPMENT SHOULD OCCUR IMMEDIATELY ALONG THE COLD FRONT AND CLOSER TO THE SHORTWAVE TO THE NORTH. LIMITED INSTABILITY SHOULD REDUCE POTENTIAL FOR SUSTAINED UPDRAFTS CAPABLE OF SMALL HAIL. WITH DRY AIR NEAR THE SURFACE...DCAPE APPROACHING 600 J/KG AND 0-6 KM BULK SHEAR APPROACHING 70 KTS...COULD SEE A FEW SUPERCELLULAR STRUCTURES ALONG/AHEAD OF THE FRONT IN THE WARM SECTOR WITH STRONG WIND GUSTS/BLOWING DUST AS THE PRIMARY THREATS... CONTINGENT IF SUSTAINED UPDRAFT ARE ABLE TO DEVELOP. LATER THIS EVENING...A CHANGE TO A RAIN/SNOW MIX IS ANTICIPATED AS TEMPERATURES COOL BEHIND THE FRONT. AS WITH THE PREVIOUS SEVERAL FORECAST RUNS...IT APPEARS THE BEST CHANCE FOR ANY ACCUMULATING SNOW REMAINS OVER YUMA COUNTY COLORADO. CONTINUE TO MENTION A RAIN/SNOW MIX IN THE FORECAST...PRIMARILY NORTH OF INTERSTATE 70 FOR TONIGHT. HOWEVER...KEPT SNOW ACCUMULATIONS LESS THAN ONE INCH FOR EVERYONE WITH HIGHEST TOTALS...BETWEEN 0.5" AND 1.0"...OVER NORTHERN YUMA COUNTY. A FEW SLICK SPOTS ON AREA ROADS ARE POSSIBLE IF PRECIPITATION IS HEAVY ENOUGH BUT WARM GROUND TEMPERATURES SHOULD LEAD TO RAPID MELTING. COOLER WEATHER SHOULD BE EXPECTED FOR THURSDAY IN THE POST-FRONTAL AIRMASS. ANOTHER SHORTWAVE TROUGH SHOULD PASS THROUGH THE NORTHWEST FLOW. AS THIS HAPPENS...WEAK ATMOSPHERIC INSTABILITY AND LIFT FROM THE SHORTWAVE SHOULD LEAD TO SHOWER/ISOLATED THUNDERSTORM DEVELOPMENT. NOT ANTICIPATING ANY SEVERE WEATHER BUT A FEW STRONG WIND GUSTS MAY BE POSSIBLE DUE TO PERSISTENT DRY AIR NEAR THE SURFACE. A SECOND COLD FRONT SHOULD MOVE THROUGH AS WELL TO REINFORCE THE COOLER AIR. CLEAR AND CALM WEATHER FINALLY RETURNS FRIDAY. HIGH TEMPERATURES IN THE UPPER 40S TO MID 50S ARE FORECAST. NORTHWEST WINDS 10-20 MPH...GUSTING TO 35 MPH ARE EXPECTED ONCE DAYTIME MIXING BEGINS TO REACH STRONG WINDS ALOFT BY LATE MORNING. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 230 PM MDT WED MAR 30 2016 THE UPPER AIR PATTERN DURING THE EXTENDED PERIOD TRANSITIONS FROM A TROUGH OVER THE NC STATES ON FRIDAY TO A DEVELOPING BROAD RIDGE MOVING IN FROM THE WEST WHICH THEN DOMINATES THE PATTERN FROM SATURDAY THROUGH THE MIDDLE OF NEXT WEEK. AS A RESULT...THE EXTENDED PERIOD WILL BE QUIET IN TERMS OF SENSIBLE WEATHER WITH TEMPERATURES WARMING TO WELL ABOVE NORMAL SUN-TUE AND NO PRECIP THROUGH THE PERIOD. FRIDAY WILL BE THE COOLEST DAY OF THE PERIOD AS STRONG NORTH WINDS ALOFT BEHIND THE EXITING UPPER TROUGH BRING DOWN COOLER AIR WITH 850 TEMPS STARTING THE DAY AROUND OC. AS A RESULT...HIGHS FRIDAY WILL BE A BIT BELOW NORMAL MAXING OUT 50-55 DEGREES. AFTER THAT... WINDS ALOFT BECOME MORE WNW AS THE UPPER RIDGE APPROACHES WHICH WILL ALLOW FOR GOOD DOWNSLOPING...ALLOWING MAX TEMPERATURES TO WARM INTO THE 70S SUN-TUE. ABOUT THE ONLY WEATHER CONCERN WOULD BE THE POTENTIAL FOR FIRE WEATHER ISSUES SUNDAY AND AGAIN ON TUESDAY. AS TEMPERATURES WARM INTO THE 70S...AFTERNOON RH VALUES WILL DROP INTO THE MIDDLE TO UPPER TEENS SUNDAY ACROSS THE SOUTHWEST QUARTER OF THE FORECAST AREA AND AGAIN TUESDAY AFTERNOON OVER THE WESTERN THIRD. ONE POSSIBLE MITIGATING FACTOR THOUGH MIGHT BE THE LACK OF STRONGER WINDS...ESPECIALLY SUNDAY AFTERNOON. WILL WATCH THESE POTENTIAL IMPACTS AS THE WEEKEND APPROACHES. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 552 AM MDT WED MAR 30 2016 PATCHY MVFR STRATUS IS EXPECTED TO IMPACT BOTH SITES THIS MORNING. STRATUS SHOULD RAPIDLY DISSIPATE AS A SURFACE LOW SLIDES EAST...PULLING IN DRY AIR FROM THE WEST AS IT DOES SO. A STRONG COLD FRONT WILL BRING STRONG NORTHWEST WIND GUSTS...CHANCES FOR SHOWERS AND STORMS AND LOWER CEILINGS THIS AFTERNOON. MVFR CONDITIONS ANTICIPATED AT KMCK ALONG WITH A CHANCE FOR A RAIN/SNOW MIX AFTER MIDNIGHT. AT KGLD...MVFR CEILINGS ARE POSSIBLE BUT WAS TOO UNCERTAIN TO PLACE INTO TAF AT THIS TIME. FINALLY...BLOWING DUST IS POSSIBLE AT KGLD ALONG WITH FRONTAL PASSAGE. FOR NOW... DID NOT REDUCE VISIBILITY TO MVFR BUT INCLUDED A 6SM BLDU GROUP. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...RRH LONG TERM...DLF AVIATION...RRH
  [top] Area Forecast Discussion National Weather Service Dodge City KS 251 PM CDT WED MAR 30 2016 .SHORT TERM...(This evening through Thursday) Issued at 205 PM CDT Wed Mar 30 2016 Our region will be placed well in the dry slot of the evolving baroclinic system across the central Plains today and tonight. The broad open upper low moving through Colorado weakens to an open wave as it moves through Nebraska tonight. With our northern counties like Trego and Ellis being on the southern periphery, we have maintained slight pops for tonight. Thunderstorms chances in the south central are quite low as the main moisture transport axis has shift well into eastern Kansas this afternoon , and the convective allowing models are persistent in cell initiation over north central Oklahoma. Beyond significantly cooler lows tonight by about 20 degrees owing to drier air and radiational cooling, cooler and still windy conditions are seen Thursday afternoon. An isolated cold air advection/instability shower or two will be possible in the afternoon as the NAM/WRF/NMM etc, indicate low reflectivity along the leading edge of invading late day clouds. .LONG TERM...(Thursday night through Wednesday) Issued at 205 PM CDT Wed Mar 30 2016 A couple of days of lingering broad upper cyclonic flow is seen in the ECMWF/GFS. Even so, the main vorticity advection rotating through the base appears well north in the Northern Plains at this time. A gradual warming in the upper 70s and near 80 degrees again by Sunday. Mild warm weather continues through the 7 day outlook , with increasingly mild overnight lows. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 109 PM CDT Wed Mar 30 2016 Southwest Kansas will remain in the dry slot of the upper system moving through the Central Plains today and tonight. This will resulting a dry forecast and mainly issues of wind (and it will be windy) direction for area terminals. At HYS, MVFR ceilings are possible overnight as the weakening upper trough lifts across Nebraska. General windy west southwest may lull briefly in the evening hours before veering west northwest. && .FIRE WEATHER... Issued at 253 AM CDT Wed Mar 30 2016 Challenging setup this afternoon for the red flag warning in the southern counties. Just as the RH is dropping to criterion in the extreme southwest, the winds have significantly slacked into the 5-10 knot range. The conditions are actually close to red flag criteria farther north, however even here the HRRR mode is overdoing both the RH and wind with respect to critical criteria. Either way, outdoor burning remains strongly discouraged across all of southwest Kansas this afternoon and evening. Cooler temperatures on Friday will make the situation not quite as bad, however, breezy winds and teens RH values in the afternoon will still create elevated fire weather conditions. && .PRELIMINARY POINT TEMPS/POPS... DDC 37 61 32 58 / 10 20 10 0 GCK 34 60 28 57 / 10 20 10 0 EHA 34 58 32 55 / 10 20 10 0 LBL 36 62 33 58 / 0 20 10 0 HYS 39 58 31 55 / 20 20 10 0 P28 42 65 36 60 / 10 20 10 0 && .DDC Watches/Warnings/Advisories... Red Flag Warning until 9 PM CDT this evening for KSZ084>090. && $$ SHORT TERM...MR LONG TERM...MR AVIATION...Russell FIRE WEATHER...MR
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1229 PM CDT WED MAR 30 2016 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 351 AM CDT WED MAR 30 2016 An intense upper low across western UT and western AZ will shear apart with one section of the upper trough lifting northeast across CO into NE, which will amplify as it phases with a northern branch upper trough digging southeast across the northern plains. The upper trough will then move east across NE and KS Tonight. As the H5 trough lifts northeast across CO into western NE and KS an H5 jet max of 55 to 60 KTS will spread northeast across eastern KS during the afternoon and evening hours. The mesoscale models such as the ARW and NMM version of the WRF and the GFS show a round of elevated thunderstorms developing as the upper jet lifts northeast from the TX PNHDL into western and central KS this morning. If these models turn out to be accurate then precip chances will be higher across the CWA during the mid and late morning hours. These elevated storms may rotate due to the increasing vertical windshear,so I can not rule out some large hail. However, the NAM and RAP models do not show elevated storms developing through the morning hours. This afternoon and evening, the surface trough and dryline will be moving east from western KS across central KS into the western counties of the CWA. There are difference in the speed of the dryline eastward progress. Most numerical model solutions move the surface dryline along a Seneca, to Manhattan line by 6 PM this evening. Surface convergence ahead of the dryline combined with ascent ahead of the H5 trough will break the weak cap and cause scattered thunderstorms to develop across northeast and east central KS. Every model shows there will be good vertical windshear and MLCAPE of 1500 J/KG to 2500 J/KG. The NAM models seems a bit too high with forecasting around 3000 J/KG of MLCAPE across east central KS. Instability will depend on how much elevated convection develops this morning, if any, and if there will be any insolation for surface heating ahead of the dryline. I think there will be widely scattered elevated thunderstorms during the mid morning hours but these storms should move northeast into MO by noon, then we should see some breaks in the OVC for surface heating ahead of the dryline. Given an environment with good vertical windshear and sufficient instability, we should see developing thunderstorms late this afternoon become supercell thunderstorms. The models due vary quite a bit on how much low-level vertical windshear will develop ahead of the dryline. The WRF model solutions show surface and 850mb winds to veer across the warm sector late this afternoon and early this evening. 0-1 KM SRH values are only 50 to 100 J/kg. Meanwhile the NAM model solution and to some extent the RAP model have surface winds a bit more backed and 850mb winds are not as veered. The NAM develops about 100 to 200 j/kg of SRH, which would be more conducive for any supercell thunderstorms to produce tornadoes. Even if winds are a bit veered as the mesoscale models forecast, I cannot rule out a few weak tornadoes. If the low-level winds back more ahead of the dryline then the tornado threat will be greater and the tornadoes may be more intense. Any supercell thunderstorms will also produce large hail and damaging wind gusts. Most of the numerical models shift the threat for severe storms east of the CWA during the mid evening hours. The NAM model hangs up the dryline across the eastern counties of the CWA and storms continue to shift northeast across east central KS. I think over the mid evening hours the isolated supercells will evolve into line segment with the main hazards being damaging winds and perhaps some flash flooding if training of storms occur across the southeast counties of the CWA. The NAM model finally shifts the thunderstorms east of the CWA after midnight. .LONG TERM...(Thursday through Tuesday) Issued at 351 AM CDT WED MAR 30 2016 Early Thursday morning a shortwave on the base of the main upper level trough will be over northeast Kansas. There remains a small chance for rain near the Nebraska boarder Thursday morning with soundings showing decent saturation and forcing in the lower levels of the atmosphere. Most the afternoon Thursday should be dry across the area before another shortwave passes just north of the area and rain chances clip extreme northeast Kansas. From here, precipitation chances end for the rest of the period. Winds shift from the south overnight Saturday, leading to a warm and dry Sunday with highs in the middle to low 70s. Sunday afternoon these southerly winds will gust up to 25kts, creating possible elevated fire concerns for this day. The rest of the period stays mild with highs generally in the upper 60s or low 70s and lows in the 40s. && .AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon) Issued at 1219 PM CDT WED MAR 30 2016 MVFR cigs are expected to continue through the 20Z. VCTS is introduced at all terminals beginning at 21Z as scattered thunderstorms are expected to develop along a dryline as it pushes east across the area. Any lingering thunderstorm activity should exit the area from west to east this evening, 01Z at MHK and 03Z at the Topeka terminals. Winds will then veer to the WNW as a cold front passes across the area overnight. Low cigs are still possible with the cold front passage, however maintain scattered MVFR and will continue to evaluate in future outlooks. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Gargan LONG TERM...Heller AVIATION...Baerg
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
129 PM EDT WED MAR 30 2016 .SYNOPSIS... HIGH PRESSURE WILL PROVIDE DRY WEATHER TODAY. A COLD FRONT WILL RETURN SHOWERS TO THE FORECAST THURSDAY AND FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FURTHER TWEAK TO TEMPS/DEWPOINTS FOR THE AFTERNOON. DEWPOINTS WERE MAINLY RAISED SLIGHTLY TO BETTER MATCH OBS AND LATEST HRRR GRIDS. REST UNCHANGED FOR NOW. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... AN UPPER TROUGH IS PROGGED TO ADVANCE FROM THE PLAINS/MIDWEST REGION TO THE GREAT LAKES BY FRIDAY. A STRONG SHORTWAVE AHEAD OF THE SYSTEM WILL CROSS THE AREA ON THURSDAY. LATEST MODEL SOLUTIONS ARE A BIT SLOWER WITH THIS FEATURE SO SLOWED THE ONSET OF POPS LATE TONIGHT. MAINTAINED CATEGORICAL POPS THURSDAY DUE TO THE DEEP MOISTURE...LARGE SCALE ASCENT...AND LOW LEVEL JET SUPPORT. A THUNDERSTORM IS POSSIBLE THURSDAY AFTERNOON...BUT OVERALL INSTABILITY IS WEAK. KEPT IN THE PREVIOUS THINKING OF CHANCE STORMS IN THE FORECAST. SURFACE LOW PRESSURE IS EXPECTED TO TRACK FROM THE UPPER MIDWEST TO ONTARIO FRIDAY. TRAILING COLD FRONT WILL CROSS THE AREA LATE THURSDAY NIGHT AND FRIDAY MORNING. INTRODUCED A BRIEF INCREASE IN POPS WITH FRONTAL PASSAGE AND ALSO INCLUDED THE MENTION OF THUNDER. TEMPERATURES SHOULD AVERAGE AROUND 10 DEGREES ABOVE SEASONAL AVERAGES UNTIL THE FRONT USHERS IN COLDER AIR ON FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... A BROAD UPPER TROUGH IS PROGGED ACROSS THE NORTHEASTERN CONUS THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. COLD AIR REINFORCING SHORTWAVES...ADVANCING THROUGH THE TROUGH...SHOULD KEEP PERIODIC RAIN/SNOW SHOWERS CHANCES AND BELOW AVERAGE TEMPERATURES THROUGH MOST OF THE LONG TERM. ADJUSTED SUPERBLEND GUIDANCE WAS USED FOR THE FORECAST TO SMOOTH OUT OPERATIONAL MODEL DIFFERENCES. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... SOUTHERLY WINDS GUSTING TO 25 KNOTS WILL CONTINUE THIS AFTERNOON...ALONG WITH VFR CONDITIONS UNDERNEATH HIGH CLOUDS. SURFACE GUSTS WILL DIMINISH AFTER SUNSET...BUT SOUTHWESTERLY LOW LEVEL JET WILL DEVELOP BY THE LATE EVENING...NECESSITATING A LLWS MENTION AT ALL TAF SITES. INCREASING MOISTURE WILL START TO LOWER CEILINGS LATE TONIGHT...WITH SHOWERS ARRIVING IN SOUTHEAST OHIO STARTING AROUND SUNRISE. RAIN WILL SLOWLY BEGIN TO OVERSPREAD THE AREA FROM WEST TO EAST...WITH SOME MVFR CONDITIONS POSSIBLE BY THE END OF THE TAF PERIOD. ANY SIGNIFICANT THREAT OF THUNDERSTORMS WILL LIKELY HOLD OFF UNTIL LATER THURSDAY AFTERNOON. CL .OUTLOOK /WEDNESDAY NIGHT THROUGH SUNDAY/... PERIODIC RESTRICTIONS ARE LIKELY WITH A THURSDAY NIGHT/FRIDAY COLD FRONT...AND THROUGH THE WEEKEND WITH SUBSEQUENT UPPER TROUGHING. && .FIRE WEATHER... GUSTY WINDS AND LOW HUMIDITY LEVELS ARE STILL EXPECTED THIS AFTERNOON. CALLS TO FORESTRY PARTNERS INDICATED THAT FUELS WERE SUFFICIENTLY MOIST TO PRECLUDE THE NEED FOR RED FLAG WARNINGS OVER OUR AREA. WE WILL CONTINUE TO MONITOR CONDITIONS THIS AFTERNOON. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ Area Forecast Discussion National Weather Service Saint Louis MO 420 PM CDT WED MAR 30 2016 .SHORT TERM... (Through Thursday) Issued at 309 PM CDT Wed Mar 30 2016 Swly flow continues to pump moisture nwd into the area this afternoon. This is expected to continue into at least the evening hours with precip dissipating overnight. However, is some uncertainty regarding how the precip will evolve tonight. Most mdl guidance suggests ongoing precip shifting nwd and ewd over the next few hours, leaving a lull earlier in the evening. While a lull is expected between the WAA precip and a line of storms that will push out ahead of the cdfnt later tonight, exactly where and when this occurs is more uncertain. Have kept PoPs tonight rather high due to ongoing and more stratiform precip between cells. The bulk of the precip shud exit ern portions of the CWA by sunrise Thurs. The cdfnt associated with this system is expected to be just W of the CWA at 12z Thurs. Mdls prog a leading s/w lifting nwd thru wrn and nrn portions of the CWA around sunrise. This may allow for some sunrise surprise storms before lifting out of the area. This shud leave the remainder of the morning dry as the cdfnt continues to push ewd. Because of the slower timing of the cdfnt, have raised temps a fair amount in some areas compared to the prev forecast. Given that parts of KS still climbed into the mid 70s today behind the fnt, the going forecast for parts of cntl and into nern MO may be too cool. However, with more question of cloud cover, esp further N, trended a little cooler, but still twd the warmest guidance. This will also allow for TSRA to develop along the fnt as it pushes sewd thru the area. Expect TSRA to develop along the fnt during the early, to perhaps mid, afternoon mainly over the ern portions of the CWA. However, am a little concerned that mdls are pushing the fnt thru the area too quickly and have pulled PoPs wwd during the day to account for this. While TSRA may develop across nrn portions of the CWA or just N, develop shud continue swwd along the fnt as the upper trof helps cool temps aloft and the cap erodes. Given forecast parameters, expect supercells to develop along the fnt. While all severe threats will be possible, believe large hail will initially be the primary threat until the storms reach far ern portions of the CWA where low level shear is greater posing a greater tornado threat. However, there is some uncertainty regarding coverage as mdls are currently suggesting much of the cap eroding during the day. While storms may be discrete, there may not be much space between them later in the afternoon. .LONG TERM... (Friday through Next Wednesday) Issued at 409 PM CDT Wed Mar 30 2016 Main changes to the forecast thru the rest of this week was to lower PoPs on Fri. Mdls keep much of the precip N of the area as the upper trof rotates thru. Did not completely remove PoPs during the afternoon as some SHRA activity is possible. Will need to watch temps for Fri night with guidance showing close to the freezing mark. However, with continued mixing expected overnight, winds may remain strong enuf to prevent frost from forming. For the weekend and beyond, not a lot of changes made from the prev forecast. More roller coaster temps expected with a rather strong cdfnt bringing a low chance for precip on Mon. This fnt will bring much cooler air into the area, and yet another possible freeze/frost event with light winds expected as the sfc ridge builds into the area. Temps shud warm quickly ahead of the next system bringing yet another chance for precip. Tilly && .AVIATION... (For the 18z TAFs through 18z Thursday Afternoon) Issued at 1221 PM CDT Wed Mar 30 2016 Scattered showers and thunderstorms will affect the area this afternoon and evening. Trend has been for these storms to produce brief downpours and small hail. VFR conditions are expected outside of the thunderstorms with a gusty south wind. Convective trends will need to be monitored this evening to the west to determine if any remnants of the severe convection makes it into the CWA overnight. A renewed threat for thunderstorms will develop with the cold front tomorrow morning for the St. Louis Metro terminals as the wind shifts to the west. Specifics for KSTL: Closely monitoring the development of showers and thunderstorms to the southwest of the terminal this afternoon and will amend TAF as convective trends are realized. South wind will remain gusty today and shift to the west with a cold front tomorrow. A renewed threat of storms will exist tomorrow morning ahead of the cold front. CVKING && .PRELIMINARY POINT TEMPS/POPS... Saint Louis 61 78 44 58 / 80 50 10 10 Quincy 57 69 38 53 / 80 30 20 30 Columbia 57 74 39 55 / 80 30 10 20 Jefferson City 58 74 40 56 / 80 30 10 20 Salem 61 77 43 60 / 90 60 10 10 Farmington 59 77 41 60 / 90 50 10 10 && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
  [top] Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 411 PM CDT WED MAR 30 2016 .DISCUSSION... Issued at 411 PM CDT WED MAR 30 2016 Strong surface low over SE Nebraska has caused warm/moist air advection into the area, with a warm sector characterized by temperatures in the upper 60s to lower 70s and dewpoints in the upper 50s to lower 60s. Cloud cover over the area has prevented robust destabilization; however, there is enough instability present to produce a few thunderstorms this evening, some strong to severe. Expect some modest increase in instability with time as another hour or two of potential heating within breaks in the clouds. With deep layer shear approaching 35 to 45 kts through the night the CAPE/shear relationship should be adequate to get a few strong updrafts, and perhaps some severe storms. As of 20z and 21z winds within the warm sector have veered a bit to around 200 degrees and that should mitigate some of the low level turning, and might even mitigate some of the convergence along the dry line, which is running from SE Nebraska down to central Oklahoma. As the night progresses expect storms that form along the dryline to eventually congeal into a complex, that could include some embedded supercellular activity. Low level shear should increase through the night, which may bring into play some embedded spin-ups within any line segments or QLCS structures. Expect these storms to move into eastern Kansas and western Missouri by 4 pm to 5 pm, and into the KC Metro area by 6 pm to 8 pm. The main hazards with these storms will be wind and hail, although with ample low level shear an isolated brief tornado or two could form. Expect this activity to move out of the area during the overnight hours and into central/eastern Missouri by midnight, if not a little sooner. Upon cold frontal passage a drier air mass will move into the area. Once the main mid level trough moves through the northern and central plains it will have less than favorable atmosphere for precipitation production, thus expect only some light showers across far northern Missouri. Once those showers move out by Thursday and Thursday night, cooler temperatures are in store for the rest of the week and into the early weekend. Temperatures then warm up for the early part of next week, then for the late part of the week another chance for some light rain. && .AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon) Issued at 1230 PM CDT WED MAR 30 2016 Ceilings through the early to mid afternoon hours will continually rise and fall above and below MVFR threshold for the next couple hours before settling into a VFR range for the afternoon. A line of thunderstorms will likely affect each terminal around 00z and should only last for an hour or two. Handled that concern with a 3 or 4 hour TEMPO depending on site, mainly to deal with uncertainty of arrival that far in advance. Will likely be able to refine timing as the event approaches. Expect storms to clear the terminals before 04z, and shortly thereafter a cold front will move through and cause winds to shift from southerly to westerly then eventually northwesterly by early Thursday morning. && .EAX Watches/Warnings/Advisories... KS...None. MO...None. && $$ DISCUSSION...Leighton AVIATION...Leighton
Area Forecast Discussion National Weather Service Saint Louis MO 402 PM CDT WED MAR 30 2016 .SHORT TERM... (Through Thursday) Issued at 309 PM CDT Wed Mar 30 2016 Swly flow continues to pump moisture nwd into the area this afternoon. This is expected to continue into at least the evening hours with precip dissipating overnight. However, is some uncertainty regarding how the precip will evolve tonight. Most mdl guidance suggests ongoing precip shifting nwd and ewd over the next few hours, leaving a lull earlier in the evening. While a lull is expected between the WAA precip and a line of storms that will push out ahead of the cdfnt later tonight, exactly where and when this occurs is more uncertain. Have kept PoPs tonight rather high due to ongoing and more stratiform precip between cells. The bulk of the precip shud exit ern portions of the CWA by sunrise Thurs. The cdfnt associated with this system is expected to be just W of the CWA at 12z Thurs. Mdls prog a leading s/w lifting nwd thru wrn and nrn portions of the CWA around sunrise. This may allow for some sunrise surprise storms before lifting out of the area. This shud leave the remainder of the morning dry as the cdfnt continues to push ewd. Because of the slower timing of the cdfnt, have raised temps a fair amount in some areas compared to the prev forecast. Given that parts of KS still climbed into the mid 70s today behind the fnt, the going forecast for parts of cntl and into nern MO may be too cool. However, with more question of cloud cover, esp further N, trended a little cooler, but still twd the warmest guidance. This will also allow for TSRA to develop along the fnt as it pushes sewd thru the area. Expect TSRA to develop along the fnt during the early, to perhaps mid, afternoon mainly over the ern portions of the CWA. However, am a little concerned that mdls are pushing the fnt thru the area too quickly and have pulled PoPs wwd during the day to account for this. While TSRA may develop across nrn portions of the CWA or just N, develop shud continue swwd along the fnt as the upper trof helps cool temps aloft and the cap erodes. Given forecast parameters, expect supercells to develop along the fnt. While all severe threats will be possible, believe large hail will initially be the primary threat until the storms reach far ern portions of the CWA where low level shear is greater posing a greater tornado threat. However, there is some uncertainty regarding coverage as mdls are currently suggesting much of the cap eroding during the day. While storms may be discrete, there may not be much space between them later in the afternoon. .LONG TERM... (Tonight through Tuesday) Issued at 351 AM CDT Wed Mar 30 2016 Could see a bit of a break in the activity early this evening, then line of storms develop ahead of main frontal boundary, tracking east into western portions of forecast area between 03z and 06z. This activity may weaken a bit as it tracks across forecast as it outraces the front. Some strong to severe storms are possible with this round. Then main frontal passage will be between 12z and 20z Thursday. Redevelopment of storms will depend on how much the atmosphere may be able to recover, at this point feel that any storms that do develop will be over southeast MO and southern IL. Highs on Thursday will range from around 60 degrees far north to the low 70s over east central/southeastern MO and southwestern IL. Thursday night and Friday will see another batch of showers slide southeast through region on backside of system, mainly affecting the areas along and north of Interstate 70. Colder air to move in with highs only in the low 50s far north to around 60 far south on Friday. Beyond that, a decent cold front to slide south through region on Saturday, but it will be a dry passage. Will just see an increase in winds, with winds picking up from the northwest on back side of front, gusting to near 35 mph at times Saturday afternoon. Otherwise, dry and near normal temperatures through the rest of the forecast period. Extended models do bring another cold front through region on Monday, but activity to stay just to the northeast of forecast area at this time. Byrd && .AVIATION... (For the 18z TAFs through 18z Thursday Afternoon) Issued at 1221 PM CDT Wed Mar 30 2016 Scattered showers and thunderstorms will affect the area this afternoon and evening. Trend has been for these storms to produce brief downpours and small hail. VFR conditions are expected outside of the thunderstorms with a gusty south wind. Convective trends will need to be monitored this evening to the west to determine if any remnants of the severe convection makes it into the CWA overnight. A renewed threat for thunderstorms will develop with the cold front tomorrow morning for the St. Louis Metro terminals as the wind shifts to the west. Specifics for KSTL: Closely monitoring the development of showers and thunderstorms to the southwest of the terminal this afternoon and will amend TAF as convective trends are realized. South wind will remain gusty today and shift to the west with a cold front tomorrow. A renewed threat of storms will exist tomorrow morning ahead of the cold front. CVKING && .PRELIMINARY POINT TEMPS/POPS... Saint Louis 61 78 44 58 / 80 50 10 10 Quincy 57 69 38 53 / 80 30 20 30 Columbia 57 74 39 55 / 80 30 10 20 Jefferson City 58 74 40 56 / 80 30 10 20 Salem 61 77 43 60 / 90 60 10 10 Farmington 59 77 41 60 / 90 50 10 10 && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
  [top] Area Forecast Discussion National Weather Service Springfield MO 310 PM CDT WED MAR 30 2016 .MESOSCALE DISCUSSION... Issued at 305 PM CDT Wed Mar 30 2016 Showers and embedded thunderstorms have overspread much of the area this afternoon in advance of upper level shortwave tracking northeast from the Red River Valley into the Ozarks region. Strong moisture advection, most unstable CAPE around 1000 J/KG, relatively steep mid level steep lapse rates and increasing deep layer shear will continue to support a continued risk for stronger convection and the potential for marginally severe hail through late this afternoon. Also monitoring the development of thunderstorms farther west across south central Kansas in advance of approaching primary upper level trough and surface dryline. This convection is progged to move east off of the line and spread eastward into far southeastern Kansas and far western Missouri late this afternoon and early this evening. This activity will have the potential to produce all modes of severe weather especially along and west of the I-49 corridor. However the scope of severe weather is conditional with potential limiting factors including the lack of instability and some question on the extent of low level shear. && .SHORT TERM...(This evening through Thursday) Issued at 305 PM CDT Wed Mar 30 2016 Expect the next round of convection to spread east from eastern Kansas into southwestern Missouri into the evening as an upper level trough transitions into the Plains. A dry line across central Kansas is not progged to be as progressive and move more slowly eastward. Storms that have formed along the dry this afternoon will shift east off of the dry line into southeastern Kansas and far southwestern Missouri early this evening. The potential exist for severe storms but the window geographically and temporarily is somewhat limited due to a relatively narrow axis of instability. The storms will encounter a more stable environment farther east into the Missouri Ozarks. Therefore expect the greatest risk for severe weather generally along and west of I-49 late this afternoon and evening with lessening risk for severe storms farther east into the Missouri Ozarks. However still expect a good coverage of showers and storms with the potential for locally heavy rainfall amounts. Localized flooding issues may materialize where storms train over the same locations. Convection could linger into Thursday morning mainly across the eastern Ozarks as the passage of the front and dry line will be somewhat delayed. .LONG TERM...(Thursday Night through Wednesday) Issued at 305 PM CDT Wed Mar 30 2016 More tranquil weather will return for the remainder of the week into the weekend as the region comes under influence of a more northwesterly upper level flow. A cool airmass will settle into the region late in the week bringing the potential for frost or freezing temperatures Friday night. The next front with a chance of rainfall will arrive the middle of next week. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 1158 AM CDT Wed Mar 30 2016 Convection started developing over the region within the past couple of hours, with some stronger storms potentially worthy of some hail or a wind gust. Will continue trend with scattered convection this afternoon, which will mainly be elevated in nature. Have been in between MVFR and IFR all day and this will likely continue into the afternoon hours. Dryline will be the main focus for strong/severe storms later this afternoon and evening. Will likely go into MVFR and maintain through the evening and into the overnight hours. && .SGF Watches/Warnings/Advisories... MO...NONE. KS...NONE. && $$ MESOSCALE...Foster SHORT TERM...Foster LONG TERM...Foster AVIATION...Lindenberg
Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 1233 PM CDT WED MAR 30 2016 .DISCUSSION... Issued at 320 AM CDT WED MAR 30 2016 Main forecast concern/challenge continues to focus on severe storm potential today. There may be several rounds of storms to deal with throughout the day and evening/overnight hours. The first wave would likely be late morning into the early afternoon and primarily be driven warm/ moist isentropic ascent. Instability is somewhat limited for this initial wave and decreases further east. Shear also looks marginal earlier in the day so this initial round has a lower potential for producing severe weather. None-the-less, there may be a few strong to severe storms given the marginal CAPE/Shear environment but strong ascent and warm/moist advection. After this initial round moves out, likely early afternoon, there may be several hours of a lull before the next potential round develops, likely in the late afternoon/early evening time frame and likely over eastern Kansas. This round looks to have the best chance at producing severe weather. But it will be a balance between when the best instability is available and when that instability begins to fade due to diurnal effects. But CAPE/Shear combinations would support organized convection, perhaps a few supercells, that would then evolve into more of a linear mode with time. The initial stages of this round would have the best potential for producing large hail and perhaps a tornado before evolving into more of a wind threat with eastward progression with time. All of this is ahead of the main dryline/surface front. The last round may be late in the evening into the overnight as the front provides the last bit of forcing. Instability really looks to be diminishing by late in the evening, and that should decrease the intensity of any storms by this time. Also, with the positively tilted nature to the trough, the bulk of the forcing for ascent will be shifted to the north and east of the forecast area. This would likely result in diminishing intensity and coverage further south, more removed from the upper support. But it still looks like a broken line of storms is possible with the frontal passage and with very strong and nearly unidirectional flow, some mixing of strong winds to the surface can`t be ruled out. Cooler conditions are expected in the wake of this system through the end of the week. By Sunday, low level flow turns southwesterly again ahead of the next system sliding southeast through the northwesterly flow. This should help temperatures climb back into the 70s on Sunday before cooling closer to normal again for next work week. && .AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon) Issued at 1230 PM CDT WED MAR 30 2016 Ceilings through the early to mid afternoon hours will continually rise and fall above and below MVFR threshold for the next couple hours before settling into a VFR range for the afternoon. A line of thunderstorms will likely affect each terminal around 00z and should only last for an hour or two. Handled that concern with a 3 or 4 hour TEMPO depending on site, mainly to deal with uncertainty of arrival that far in advance. Will likely be able to refine timing as the event approaches. Expect storms to clear the terminals before 04z, and shortly thereafter a cold front will move through and cause winds to shift from southerly to westerly then eventually northwesterly by early Thursday morning. && .EAX Watches/Warnings/Advisories... KS...None. MO...None. && $$ DISCUSSION...CDB AVIATION...Leighton
Area Forecast Discussion...Updated Aviation National Weather Service Saint Louis MO 1229 PM CDT WED MAR 30 2016 .SHORT TERM... (Through Late This Afternoon) Issued at 351 AM CDT Wed Mar 30 2016 Each new model run is a bit slower with system that is approaching region. However, decent moisture convergence as low level jet ramps up this morning. So will see scattered showers and storms develop ahead of system, especially over southeastern MO late this morning. Then coverage will be on the increase this afternoon as instability increases and mid level lapse rates steepen ahead of trof. A few of the storms could be severe and will be capable of producing large hail and damaging winds. High temps will depend on precipitation and cloud cover, but with gusty south winds, will see highs in the mid 60s to low 70s. Byrd .LONG TERM... (Tonight through Tuesday) Issued at 351 AM CDT Wed Mar 30 2016 Could see a bit of a break in the activity early this evening, then line of storms develop ahead of main frontal boundary, tracking east into western portions of forecast area between 03z and 06z. This activity may weaken a bit as it tracks across forecast as it outraces the front. Some strong to severe storms are possible with this round. Then main frontal passage will be between 12z and 20z Thursday. Redevelopment of storms will depend on how much the atmosphere may be able to recover, at this point feel that any storms that do develop will be over southeast MO and southern IL. Highs on Thursday will range from around 60 degrees far north to the low 70s over east central/southeastern MO and southwestern IL. Thursday night and Friday will see another batch of showers slide southeast through region on backside of system, mainly affecting the areas along and north of Interstate 70. Colder air to move in with highs only in the low 50s far north to around 60 far south on Friday. Beyond that, a decent cold front to slide south through region on Saturday, but it will be a dry passage. Will just see an increase in winds, with winds picking up from the northwest on back side of front, gusting to near 35 mph at times Saturday afternoon. Otherwise, dry and near normal temperatures through the rest of the forecast period. Extended models do bring another cold front through region on Monday, but activity to stay just to the northeast of forecast area at this time. Byrd && .AVIATION... (For the 18z TAFs through 18z Thursday Afternoon) Issued at 1221 PM CDT Wed Mar 30 2016 Scattered showers and thunderstorms will affect the area this afternoon and evening. Trend has been for these storms to produce brief downpours and small hail. VFR conditions are expected outside of the thunderstorms with a gusty south wind. Convective trends will need to be monitored this evening to the west to determine if any remnants of the severe convection makes it into the CWA overnight. A renewed threat for thunderstorms will develop with the cold front tomorrow morning for the St. Louis Metro terminals as the wind shifts to the west. Specifics for KSTL: Closely monitoring the development of showers and thunderstorms to the southwest of the terminal this afternoon and will amend TAF as convective trends are realized. South wind will remain gusty today and shift to the west with a cold front tomorrow. A renewed threat of storms will exist tomorrow morning ahead of the cold front. CVKING && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
Area Forecast Discussion National Weather Service Springfield MO 1204 PM CDT WED MAR 30 2016 .SHORT TERM...(Today and tonight) Issued at 245 AM CDT Wed Mar 30 2016 The main concern for this time frame remains unchanged: Severe weather potential. Strong low pressure will shift east across Neb with a trailing dryline reaching the Flint Hills region of KS by early evening 7pm/31-00z. The main concern will be how much convection will be able to fire along the dryline late today and this evening while moderate instability is in place. Some modest moisture return at around 850mb is evident in sfc observations and is in line with RAP progged soundings in the near term. Moisture is advecting n-ne underneath and elevated mixed layer/cap along with more extensive mid/upper level moisture. Will still take some work to get precip going with sfc dew points still in the low/mid 30s. Subtle mid level impulses moving northeast from the southern Plains will increase overall lift while deeper low level moisture rapidly increases for the southwest this morning increasing chances for elevated convection with mucapes reaching up to near 1500 j/kg. Can`t rule out some hail with stronger updrafts given good mid level lapse rates. There will be a break, or at least a partial one, in the overall coverage of showers during the mid afternoon. Attention then turns to the dryline off to our west. A narrow corridor of moderate surface based instability is expected to develop with uncapped mlcape values of about 1500 j/kg by early evening (progged GFS KJLN sounding). The temporal window for progged robust instability (GFS) looks small late today and this evening but given the strong vertical shear a large hail and tornado threat exists where discreet convection can develop. The high res ARW and NMM are not too bullish in moving the convection too far off the dryline initially so it looks like the best chance for severe storms late today and this evening will be over the western cwfa. As the low continues off to the east, a cold front catches up to the dryline and moves east through the cwfa overnight. Again, high res models are not to bullish with convection as the front sweeps through with more robust convection to our south limited moisture/buoyancy over our area (as mentioned in SPC discussion). Will need to watch trends closely as the weather evolves today. The SPC day 1 looks good with a slightly higher probability of tornadoes over the far western cwfa and a general 15% hail and wind risk over most of the area. The hail risk will likely be more tied to earlier elevated convection and then what every develops near the dryline. The wind risk will be more late today and tonight. .LONG TERM...(Thursday through Tuesday) Issued at 245 AM CDT Wed Mar 30 2016 A colder and dry air mass moves into the area behind the front Thu. Frost headlines may be needed with the coldest night/early morning looking to be Fri/Sat morning. A couple of shortwaves moving through the upper level nw flow may produce some clouds brief sprinkles over the northeast cwfa Fri. A quick warming trend will occur this weekend. Another front is expected to move south into/through the area Monday, but with dry air expected to be in place, only modest rain chances are expected at best. Cooler and dry weather is expected for day 7/Tue. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 1158 AM CDT Wed Mar 30 2016 Convection started developing over the region within the past couple of hours, with some stronger storms potentially worthy of some hail or a wind gust. Will continue trend with scattered convection this afternoon, which will mainly be elevated in nature. Have been in between MVFR and IFR all day and this will likely continue into the afternoon hours. Dryline will be the main focus for strong/severe storms later this afternoon and evening. Will likely go into MVFR and maintain through the evening and into the overnight hours. && .SGF Watches/Warnings/Advisories... MO...NONE. KS...NONE. && $$ SHORT TERM...DSA LONG TERM...DSA AVIATION...Lindenberg
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
321 PM CDT WED MAR 30 2016 .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 321 PM CDT WED MAR 30 2016 PRECIP CHANCES AND TYPE TONIGHT THROUGH TOMORROW WILL BE THE PRIMARY FORECAST CHALLENGE. WV LOOP SHOWS THE MAIN UPPER LOW STILL DOWN OVER SE WY/NE CO/NEB PANHANDLE AREA...WITH A NORTHERN BRANCH SHORTWAVE DIGGING DOWN THROUGH SASKATCHEWAN. MOST OF THE MODEL RUNS HAVE BEEN TRENDING STRONGER WITH THIS FEATURE...BRINGING IT DOWN THROUGH ND LATE TONIGHT AND INTO CENTRAL SD BY TOMORROW. BOTH THE SHORT/HIGH RES DETERMINISTIC MODELS AS WELL AS THE GLOBAL RUNS BRING SOME HEALTHY QPF INTO OUR NORTHWESTERN COUNTIES BY TOMORROW MORNING. THE GFS AND RAP BOTH HAVE SOME FAIRLY STRONG MID LEVEL FRONTOGENESIS ALONG WITH GOOD Q VECTOR CONVERGENCE MOVING THROUGH THE NORTHWESTERN COUNTIES DURING THE EARLY MORNING HOURS. BY 18Z THURSDAY...THE BEST FRONTOGENESIS/MID LEVEL DEFORMATION ZONE MOVES INTO THE CENTRAL AND SOUTHERN CWA WITH A FAIRLY TIGHT GRADIENT BEHIND THE SYSTEM. BUMPED UP POPS AND QPF FROM 06Z TONIGHT THROUGH THE REST OF THE DAY ON THURSDAY. SOMEWHAT QUESTIONABLE AS TO PRECIP TYPE. THE SREF PROBABILITIES HAVE SOME DECENT CHANCES OF SNOW ON THE BACK SIDE OF THE PRECIP...BUT TEMPS ON THE COLD SIDE OF THE SFC LOW IN CANADA ARE CURRENTLY IN THE 40S AND 50S. 925MB TEMPS ARE RIGHT AT THE 0 C MARK...BUT SOME DYNAMIC COOLING IS NOT OUT OF THE QUESTION AS THE COLUMN SATURATES. INCLUDED SOME SNOW MIXING IN LATE TONIGHT OVER THE DEVILS LAKE BASIN AND PUT AROUND AN INCH OF ACCUMULATION...BUT NOT CONFIDENT ENOUGH TO PUT ANY HIGHLIGHT OUT AT THIS POINT. THINK THE PRECIP WILL CHANGE BACK OVER TO RAIN DURING THE DAY ON THURSDAY AS THE SYSTEM DIGS SOUTHEASTWARD. THE SHORTWAVE WILL MOVE OUT OF THE AREA ON THURSDAY NIGHT...BUT ANOTHER WEAK REINFORCING SHORTWAVE WILL DIG DOWN AND HELP PUSH ANOTHER SURGE OF COLDER AIR DOWN INTO THE REGION. THINK THAT MUCH OF THE PRECIP WILL BE OVER OUR SOUTHEAST BY THURSDAY EVENING AND THEN WE SHOULD SEE A BIT OF A BREAK TOWARDS FRIDAY MORNING. TEMPS THURSDAY NIGHT SHOULD BE BACK DOWN INTO THE 20S. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 321 PM CDT WED MAR 30 2016 FRIDAY THROUGH SATURDAY...NORTHWESTERLY FLOW ALOFT SETS UP OVER THE NORTHERN PLAINS...AND THERE IS GOOD AGREEMENT ON A WEAK SHORTWAVE TROUGH/JET STREAK DIGGING DOWN FROM SOUTHERN MANITOBA INTO THE UPPER MIDWEST. THIS CLIPPER SYSTEM SHOULD BRING A CHANCE FOR PRECIP TO OUR NORTHEASTERN COUNTIES. THE BEST FRONTOGENESIS SEEMS THAT IT WILL BE TO THE NORTH AND EAST OF OUR COUNTIES...BUT GIVEN OUR TENDENCY TO UNDERESTIMATE THESE TYPE OF CLIPPER SYSTEMS WILL BUMP UP PRECIP CHANCES AND AMOUNTS. TEMPS WILL BE COOLER WITH HIGHS STAYING IN THE 30S AND 40S ON FRIDAY WITH 20S AND 30S ON SATURDAY. THINK THAT PRECIP OVER OUR NORTHEASTERN COUNTIES WILL BE MOSTLY SNOW...AND SOME ACCUMULATIONS OF AN INCH OR TWO ARE NOT OUT OF THE QUESTION. FOR SATURDAY NIGHT THROUGH WEDNESDAY... NORTHWEST FLOW ALOFT ON SAT WITH SOME CHANCE OF PRECIPITATION AS A SURFACE LOW APPROACHES. NORTHWEST FLOW CONTINUES THROUGH MON AS RIDGE BUILDS IN THE WEST. SURFACE HIGH PRESSURE FROM CANADA MEANS NO PRECIPITATION EXPECTED... SLIGHTLY COOLER. UPPER LEVEL RIDGE MOVES IN THROUGHOUT TUES... IMPLYING WARMER TEMPERATURES. WINDS IN WESTERN ND SHOULD HAVE A WARMING WESTERLY COMPONENT. ON WED A SURFACE LOW MOVES THROUGH THE AREA... BRINGING CHANCES OF PRECIP AND COOLER TEMPS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1244 PM CDT WED MAR 30 2016 A LITTLE BIT OF DRIZZLE CLIPPED KFAR/KBJI THIS MORNING ALONG WITH SOME LOW CLOUDS. NOW QUITE A BIT OF CUMULUS IS FORMING IN THE SUNNY REGION JUST BEHIND THESE SLOWLY DEPARTING LOW CLOUDS. LOOKS LIKE THIS CUMULUS WILL AFFECT MOST OF THE TAF SITES THIS AFTERNOON WITH EITHER A SCT OR BKN LAYER. NORTH WINDS DECREASE SOME TONIGHT BEFORE INCREASING AGAIN ON THU MORNING. GUIDANCE IS SHOWING IT BECOMING RATHER GUSTY BY MID MORNING ALONG AND WEST OF THE VALLEY. ALONG WITH THE INCREASING WINDS...MODELS ALSO BRING IN SOME PCPN THU MORNING. NOT SURE IF THIS WILL BE RAIN...SNOW...OR A MIX...SO FOR NOW HAVE GONE WITH A MIX AND LATER SHIFTS CAN REFINE A LITTLE BETTER. NAM/GFS WERE A LITTLE FASTER BRINGING THIS IN WITH THE ECMWF ONLY BRINGING IT INTO KDVL ON THU MORNING. SO THERE ARE STILL SOME DIFFERENCES BETWEEN THE VARIOUS MODEL SOLUTIONS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...JR LONG TERM...JR/GODON AVIATION...GODON
AREA FORECAST DISCUSSION
NWS NORMAN OK
1237 PM CDT WED MAR 30 2016 .DISCUSSION... FIRE WEATHER AND 30/18Z AVIATION DISCUSSIONS FOLLOW... && .FIRE WEATHER... A RED FLAG WARNING REMAINS VALID FOR WESTERN OKLAHOMA AND PORTIONS OF WESTERN NORTH TEXAS THROUGH THIS EVENING. RAPID SCAN SATELLITE OPERATIONS ARE BEING UTILIZED TO MONITOR FOR NEW FIRE IGNITIONS. CRITICALLY DRY AIR IS BEGINNING TO SPREAD THROUGH THE OKLAHOMA PANHANDLE AND TOWARD WESTERN OKLAHOMA AT THIS TIME. FIRE CONDITIONS WILL DETERIORATE WEST OF THE DRYLINE THROUGHOUT THE AFTERNOON. THE MOST FIRE EFFECTIVE CONDITIONS WILL OCCUR BETWEEN APPROXIMATELY 3-7 PM...WHEN RH/WIND COMBINATIONS WILL APPROACH AND/OR LOCALLY EXCEED EXTREMELY CRITICAL THRESHOLDS...ESPECIALLY OVER WESTERN NORTH TEXAS AND SOUTHWESTERN OKLAHOMA. IT IS IMPORTANT TO NOTE CONDITIONS WILL NOT BE AS SEVERE AS LAST WEEK...BUT POSITIVE EFFECTS OF THE WEEKEND MOISTURE HAVE BEEN MITIGATED IN FINE FUELS AND A FAVORABLE MESOSCALE PATTERN FOR FIRE IS IDENTIFIED WITH A LOW LEVEL THERMAL RIDGE JUST WEST OF THE DRYLINE BEING OVERSPREAD BY STRONGER WINDS ALOFT. PRIMARY CONCERN WILL BE FOR MAINTAINING THE REPORTED 95 PERCENT CONTAINMENT OF THE ANDERSON CREEK FIRE GIVEN TODAY/S CRITICAL WEATHER...AND MONITORING FOR NEWLY DETECTED FIRE STARTS. LINDLEY && .AVIATION...30/18Z TAF ISSUANCE... MVFR CONDITIONS AND VCTS CONTINUE TO BE THE PRIMARY CONCERNS FOR AVIATORS ACROSS CENTRAL OKLAHOMA. EXPECT MVFR CONDITIONS TO PERSIST FOR AIRFIELDS ACROSS CENTRAL AND INTO SOUTHWESTERN OKLAHOMA AND PORTIONS OF WESTERN NORTH TEXAS. VIS SAT AND OBS SHOW SOME IMPROVEMENT TO CEILINGS... BUT CLOUDS HAVE BEEN SLOW TO MOVE EAST. THUNDERSTORMS CURRENTLY AND ADDITIONAL DEVELOPMENT THIS AFTERNOON WILL LIKELY IMPACT AIRFIELDS ACROSS SOUTHWESTERN OKLAHOMA AND CENTRAL OKLAHOMA AND NORTHERN TEXAS. STRONG SOUTHWEST WINDS THIS AFTERNOON... GUSTING 30 TO 35 KTS ACROSS WESTERN OKLAHOMA... WILL IMPACT WESTERN AIRFIELDS. WINDS OVERALL WILL REMAIN BREEZY OUT OF THE SOUTHWEST BEFORE SHIFTING TO THE WEST/NORTHWEST LATE IN THE PERIOD. KURTZ && .PREV DISCUSSION... /ISSUED 1152 AM CDT WED MAR 30 2016/ DISCUSSION... PRIMARY FORECAST FOCUS IS ON THE EVOLVING CONVECTIVE AND FIRE WEATHER CONCERNS TODAY/TONIGHT. CURRENTLY... I/VE STARTED... STOPPED... AND RE-WROTE THIS AFD SEVERAL TIMES IN THE LAST HOUR... SO YES... IT/S A MESSY CONVECTIVE SET UP TODAY. SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP ACROSS PORTIONS OF CENTRAL AND EASTERN OKLAHOMA. FROM 16Z SFC ANALYSIS... CONVERGENCE OF SFC WINDS AND HIGHER DEW POINTS... MID TO UPPER 60S... HAVE POOLED ALONG A SUBTLE 850/700MB FRONT ACROSS THE REGION. EXPECT THIS ACTIVITY TO CONTINUE AND PUSH EASTWARD THROUGH THE EARLY AFTERNOON HOURS. SEVERE CHANCES FROM THIS ACTIVITY WILL BE FOCUSED ON HAIL... WITH 1 TO 1 AND HALF INCH HAIL EXPECTED WITH THE STRONGEST UPDRAFTS. BIG DISCUSSION IN THE OFFICE AT THE MOMENT IS THE THOUGHT THAT THIS MAY BE THE EVENT FOR TODAY... AS THIS DEVELOPMENT WILL HAVE SOME... POSSIBLY MODERATE IMPACT... ON ANY DEVELOPMENT ALONG THE DRY LINE THIS AFTERNOON. WITH THAT IN MIND... THE EXPERIMENTAL HRRR HAS DONE WELL OVER ITS LAST THREE RUNS WITH THIS INITIAL CONVECTION AND WE/LL HAVE TO KEEP AN EYE ON IT INTO THE AFTERNOON. I/LL TOUCH MORE ON THAT BELOW. FIRST... DON/T FORGET FIRE WEATHER... IMPRESSIVE DEW POINTS UP STREAM IN SOUTHEASTERN COLORADO/NORTHEASTERN NEW MEXICO... SINGLE DIGITS TO TEENS... WILL CONTINUE TO ADVECT EASTWARD AS THE DRY LINE CONTINUES TO DEVELOP JUST OFF THE LLANO ESTACADO IN THE EASTERN PANHANDLES. AS THE DRY LINE SURGES EAST THROUGH 1 TO 3 PM ACROSS WESTERN OKLAHOMA AND WESTERN NORTH TEXAS... RH VALUES WILL TANK INTO THE LOW TO MID TEENS... WHILE ALREADY BREEZY S/SW WINDS INCREASE... BECOMING MORE W/SW WITH GUSTS APPROACHING 30 TO 40 MPH THROUGH THE AFTERNOON. CRITICAL TO EXTREME FIRE WEATHER CONDITIONS WILL PERSIST THROUGH SUNSET. AT PRESENT TIME... DO NOT PLAN ON MAKING ANY CHANGES TO THE GOING RED FLAG WARNING IN EFFECT WITH THE AFTERNOON FORECAST ISSUANCE. STRONG TO SEVERE STORMS THROUGH THE AFTERNOON... AS MENTIONED ABOVE... 16Z SFC ANALYSIS REVEALS THE SFC TROUGH/ASSOCIATED BOUNDARY EXTENDS FROM CENTRAL KANSAS INTO NORTHWESTERN OKLAHOMA AND SOUTHWEST INTO THE TEXAS PANHANDLE. WITH THE PUSH OF THIS BOUNDARY... CLOUD COVER CONTINUES TO BREAK ALONG/AHEAD OF THE BOUNDARY... BUT DISSIPATION IS SLOW... HAVE SEEN A FEW BREAKS AT THE OFFICE... AND ON VIS... SO EXPECT THIS TREND TO CONTINUE THROUGH THE EARLY AFTERNOON AS THE CURRENT/INITIAL CONVECTION PUSHES EAST. COULD SEE A SHORT BREAK IN ACTIVITY ACROSS CENTRAL OKLAHOMA BEFORE THE DRY LINE MAKES ITS SURGE INTO CENTRAL OKLAHOMA THROUGH 2 TO 4 PM. LATEST EXPERIMENTAL HRRR... 30/13Z HAS COME IN MORE AGGRESSIVE WITH OVERALL COVERAGE OF CONVECTION... AROUND 19 TO 20Z. THIS IS STILL A MESSY CONVECTIVE SETUP... HOW THE ATMOSPHERE REBOUNDS FROM EARLY CONVECTION WILL PLAY A VITAL ROLE THIS AFTERNOON. STILL... WITH SIGNIFICANT SFC DEW POINTS... IN THE MID TO UPPER 60S APPROACHING 70... SBCAPE VALUES WILL POOL AHEAD OF THE DRY LINE IN THE 1500 TO 3000 J/KG RANGE. DEEP LAYER SHEAR SUGGESTS SUPPORT FOR DAMAGING HAIL... UP TO GOLF BALLS... POSSIBLY LARGER... NEAR TENNIS BALLS. AS FOR TORNADO POTENTIAL... LOW LEVEL SHEAR AND SFC WINDS ARE NOT OVERLY IMPRESSIVE... 0-1 KM AND 0-3 KM HELICITIES ARE WEAK AS THE DRY LINE PUSHES THROUGH CENTRAL OKLAHOMA THIS AFTERNOON... WITH VALUES OF 0-1 KM HELICITY ONLY 50 TO 120 S2/H2. HOWEVER... WITH LOWER LCLS AND STRONG UPDRAFT DEVELOPMENT... A TORNADO OR TWO CANNOT BE RULED OUT. NOW... AS WE MOVE INTO THE AFTERNOON... THE CHANCE FOR DAMAGING HAIL AND MORE ORGANIZED CONVECTION LOOKS TO DEVELOP OVER SOUTH CENTRAL/SOUTHEASTERN OKLAHOMA. AFTER SUNSET... THE LLJ WILL INCREASE AS THE H500 SHORT WAVE BEGINS TO SWING EAST OFF THE HIGH PLAINS... INCREASING CONVECTIVE DEVELOPMENT ACROSS SOUTHEASTERN OKLAHOMA... LIKELY EAST OF OUR CWA IN TULSA AND SHREVEPORT/S AREAS. JUST A QUICK LOOK... BUT 0-1KM COMPUTED CAPE AND 0-3KM SHEAR COMPARED TO CORFIDI VECTORS... A DECENT MCS WILL LIKELY DEVELOP ACROSS THE NORTHERN PORTIONS OF THE ARKLATEX TOWARDS THE OUACHITAS AND SOUTHERN OZARKS. LATER AFDS ISSUED THIS AFTERNOON WILL CONTINUE TO FOCUS ON TODAY AND TONIGHT. KURTZ && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 47 67 40 61 / 10 0 0 0 HOBART OK 44 68 37 61 / 0 0 0 0 WICHITA FALLS TX 46 70 42 61 / 10 0 0 10 GAGE OK 39 64 33 60 / 0 0 0 0 PONCA CITY OK 44 65 37 60 / 20 0 0 0 DURANT OK 54 70 44 61 / 40 10 0 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR OKZ004>006- 009>011-014>016-021-022-033>037. TX...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR TXZ083>085-087- 088. && $$ 09/04
AREA FORECAST DISCUSSION
NWS NORMAN OK
1152 AM CDT WED MAR 30 2016 .DISCUSSION... PRIMARY FORECAST FOCUS IS ON THE EVOLVING CONVECTIVE AND FIRE WEATHER CONCERNS TODAY/TONIGHT. CURRENTLY... I/VE STARTED... STOPPED... AND RE-WROTE THIS AFD SEVERAL TIMES IN THE LAST HOUR... SO YES... IT/S A MESSY CONVECTIVE SET UP TODAY. SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP ACROSS PORTIONS OF CENTRAL AND EASTERN OKLAHOMA. FROM 16Z SFC ANALYSIS... CONVERGENCE OF SFC WINDS AND HIGHER DEW POINTS... MID TO UPPER 60S... HAVE POOLED ALONG A SUBTLE 850/700MB FRONT ACROSS THE REGION. EXPECT THIS ACTIVITY TO CONTINUE AND PUSH EASTWARD THROUGH THE EARLY AFTERNOON HOURS. SEVERE CHANCES FROM THIS ACTIVITY WILL BE FOCUSED ON HAIL... WITH 1 TO 1 AND HALF INCH HAIL EXPECTED WITH THE STRONGEST UPDRAFTS. BIG DISCUSSION IN THE OFFICE AT THE MOMENT IS THE THOUGHT THAT THIS MAY BE THE EVENT FOR TODAY... AS THIS DEVELOPMENT WILL HAVE SOME... POSSIBLY MODERATE IMPACT... ON ANY DEVELOPMENT ALONG THE DRY LINE THIS AFTERNOON. WITH THAT IN MIND... THE EXPERIMENTAL HRRR HAS DONE WELL OVER ITS LAST THREE RUNS WITH THIS INITIAL CONVECTION AND WE/LL HAVE TO KEEP AN EYE ON IT INTO THE AFTERNOON. I/LL TOUCH MORE ON THAT BELOW. FIRST... DON/T FORGET FIRE WEATHER... IMPRESSIVE DEW POINTS UP STREAM IN SOUTHEASTERN COLORADO/NORTHEASTERN NEW MEXICO... SINGLE DIGITS TO TEENS... WILL CONTINUE TO ADVECT EASTWARD AS THE DRY LINE CONTINUES TO DEVELOP JUST OFF THE LLANO ESTACADO IN THE EASTERN PANHANDLES. AS THE DRY LINE SURGES EAST THROUGH 1 TO 3 PM ACROSS WESTERN OKLAHOMA AND WESTERN NORTH TEXAS... RH VALUES WILL TANK INTO THE LOW TO MID TEENS... WHILE ALREADY BREEZY S/SW WINDS INCREASE... BECOMING MORE W/SW WITH GUSTS APPROACHING 30 TO 40 MPH THROUGH THE AFTERNOON. CRITICAL TO EXTREME FIRE WEATHER CONDITIONS WILL PERSIST THROUGH SUNSET. AT PRESENT TIME... DO NOT PLAN ON MAKING ANY CHANGES TO THE GOING RED FLAG WARNING IN EFFECT WITH THE AFTERNOON FORECAST ISSUANCE. STRONG TO SEVERE STORMS THROUGH THE AFTERNOON... AS MENTIONED ABOVE... 16Z SFC ANALYSIS REVEALS THE SFC TROUGH/ASSOCIATED BOUNDARY EXTENDS FROM CENTRAL KANSAS INTO NORTHWESTERN OKLAHOMA AND SOUTHWEST INTO THE TEXAS PANHANDLE. WITH THE PUSH OF THIS BOUNDARY... CLOUD COVER CONTINUES TO BREAK ALONG/AHEAD OF THE BOUNDARY... BUT DISSIPATION IS SLOW... HAVE SEEN A FEW BREAKS AT THE OFFICE... AND ON VIS... SO EXPECT THIS TREND TO CONTINUE THROUGH THE EARLY AFTERNOON AS THE CURRENT/INITIAL CONVECTION PUSHES EAST. COULD SEE A SHORT BREAK IN ACTIVITY ACROSS CENTRAL OKLAHOMA BEFORE THE DRY LINE MAKES ITS SURGE INTO CENTRAL OKLAHOMA THROUGH 2 TO 4 PM. LATEST EXPERIMENTAL HRRR... 30/13Z HAS COME IN MORE AGGRESSIVE WITH OVERALL COVERAGE OF CONVECTION... AROUND 19 TO 20Z. THIS IS STILL A MESSY CONVECTIVE SETUP... HOW THE ATMOSPHERE REBOUNDS FROM EARLY CONVECTION WILL PLAY A VITAL ROLE THIS AFTERNOON. STILL... WITH SIGNIFICANT SFC DEW POINTS... IN THE MID TO UPPER 60S APPROACHING 70... SBCAPE VALUES WILL POOL AHEAD OF THE DRY LINE IN THE 1500 TO 3000 J/KG RANGE. DEEP LAYER SHEAR SUGGESTS SUPPORT FOR DAMAGING HAIL... UP TO GOLF BALLS... POSSIBLY LARGER... NEAR TENNIS BALLS. AS FOR TORNADO POTENTIAL... LOW LEVEL SHEAR AND SFC WINDS ARE NOT OVERLY IMPRESSIVE... 0-1 KM AND 0-3 KM HELICITIES ARE WEAK AS THE DRY LINE PUSHES THROUGH CENTRAL OKLAHOMA THIS AFTERNOON... WITH VALUES OF 0-1 KM HELICITY ONLY 50 TO 120 S2/H2. HOWEVER... WITH LOWER LCLS AND STRONG UPDRAFT DEVELOPMENT... A TORNADO OR TWO CANNOT BE RULED OUT. NOW... AS WE MOVE INTO THE AFTERNOON... THE CHANCE FOR DAMAGING HAIL AND MORE ORGANIZED CONVECTION LOOKS TO DEVELOP OVER SOUTH CENTRAL/SOUTHEASTERN OKLAHOMA. AFTER SUNSET... THE LLJ WILL INCREASE AS THE H500 SHORT WAVE BEGINS TO SWING EAST OFF THE HIGH PLAINS... INCREASING CONVECTIVE DEVELOPMENT ACROSS SOUTHEASTERN OKLAHOMA... LIKELY EAST OF OUR CWA IN TULSA AND SHREVEPORT/S AREAS. JUST A QUICK LOOK... BUT 0-1KM COMPUTED CAPE AND 0-3KM SHEAR COMPARED TO CORFIDI VECTORS... A DECENT MCS WILL LIKELY DEVELOP ACROSS THE NORTHERN PORTIONS OF THE ARKLATEX TOWARDS THE OUACHITAS AND SOUTHERN OZARKS. LATER AFDS ISSUED THIS AFTERNOON WILL CONTINUE TO FOCUS ON TODAY AND TONIGHT. KURTZ && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 78 47 67 40 / 40 10 0 0 HOBART OK 80 44 68 37 / 20 0 0 0 WICHITA FALLS TX 83 46 70 42 / 30 10 0 0 GAGE OK 77 39 64 33 / 0 0 0 0 PONCA CITY OK 78 44 65 37 / 30 20 0 0 DURANT OK 74 54 70 44 / 70 40 10 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR OKZ004>006- 009>011-014>016-021-022-033>037. TX...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR TXZ083>085-087- 088. && $$ 09/04
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SYNOPSIS... ISSUED AT 230 PM CDT WED MAR 30 2016 A VERY CHILLY PERIOD WITH SEVERAL ROUNDS OF PRECIPITATION...SOME WINTRY. THE UPPER PATTERN INVOF NOAM IS QUITE AMPLIFIED...AND DOMINATED BY STG RIDGE ALONG THE WEST COAST. THE DOWNSTREAM FLOW IS SPLIT...WITH THE FCST AREA UNDER THE INFLUENCE OF ENERGETIC SRN STREAM. ALTHOUGH THE WRN RIDGE WL LOSE AMPLITUDE DURING THE FIRST PART OF THE FCST PERIOD...DOWNSTREAM CONSOLIDATION OF THE FLOW IS LIKELY AS VERY STG NWLY SPEED MAX DIGS SE ACRS CANADA AND INTO THE ERN CONUS. ONCE THAT FEATURE PASSES THROUGH...A GRADUAL DEAMPLIFICATION OF THE FLOW IS EXPECTED FOR A COUPLE DAYS BEFORE THE WRN RIDGE BEGINS TO REBUILD. TEMPS WL BE WELL BELOW NORMAL FOR MOST OF THE PERIOD...BEFORE REBOUNDING CLOSE TO SEASONAL NORMALS LATE. THE COLDEST DAYS LOOK TO BE SAT/SUN/MON...WHEN MOST AREAS WON/T BE ABLE TO GET OUT OF THE 30S. PRECIPITATION AMOUNTS WILL PROBABLY END UP ABOVE NORMAL FOR THE PERIOD...WITH THE BULK OF THE PRECIPITATION FALLING WITH THE NEXT 36 HOURS. && .SHORT TERM...TONIGHT AND THURSDAY ISSUED AT 230 PM CDT WED MAR 30 2016 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE POSITIONED OVER EASTERN NEBRASKA AND A SURFACE TROUGH/WEAK COLD FRONT EXTENDING FROM THE LOW NORTHEAST INTO NORTH-CENTRAL WI AND THE CENTRAL U.P. LIGHT TO MODERATE RAINFALL ASSOCIATED WITH A WEAK SHORTWAVE IS EXITING NORTHEAST WI...WHILE LIGHT SHOWERS AND DRIZZLE ARE LINGERING ACROSS NORTH-CENTRAL WI. THINK WILL SEE A LULL IN THE PRECIP BEHIND THE WAVE AS WEAK SUBSIDENCE MOVES OVERHEAD THROUGH THE REST OF THE AFTERNOON. BUT AS THE LOW PRESSURE SYSTEM MOVES NORTHEAST TONIGHT AND THURSDAY...PRECIP CHANCES/AMOUNTS AND POSSIBLE SNOW ACCUMS ARE THE MAIN FORECAST CONCERNS. TONIGHT...THE COLD FRONT POSITIONED OVER NORTH-CENTRAL WISCONSIN WILL SAG INTO SOUTHEAST WISCONSIN AS LOW PRESSURE TRAVELS ALONG IT. AS MID-LEVEL FLOW BACKS AND UPPER DIVERGENCE INCREASES AHEAD OF THE LOW...SHOULD SEE FGEN RAMP UP IN A REGION OF MOISTURE TRANSPORT OVER CENTRAL AND NORTHEAST WISCONSIN. THIS ALL POINTS TOWARDS ANOTHER ROUND OF RAINFALL MOVING INTO THIS REGION BY MID TO LATE EVENING AND CONTINUING OVERNIGHT. THE MESOMODELS SUGGEST THAT THE HEAVIEST PRECIP WILL MOSTLY FALL SOUTH OF THE FORECAST AREA...ALTHOUGH AN AREA OF HEAVIER PRECIP MAY GRAZE THE WINNEBAGO THROUGH KEWAUNEE COUNTY AREAS. A HALF INCH TO AN INCH OF RAIN IS POSSIBLE OVER CENTRAL AND NORTHEAST WI TONIGHT...WHICH RIVERS SHOULD BE OK TO HANDLE...UNLESS THUNDERSTORMS DEVELOP AND BOOST RAINFALL FURTHER. THINK CHANCES OF THIS OCCURRING IS PRETTY LOW...BUT WILL KEEP A SLIGHT CHANCE MENTION OF THUNDER SOUTH OF A WAUSAU TO GREEN BAY LINE. OVER NORTH-CENTRAL WI...RAINFALL AMOUNTS WILL BE MUCH LIGHTER. ON AND OFF LIGHT SHOWERS/DRIZZLE WILL LIKELY MIX WITH SNOW LATE TONIGHT. LOWS RANGING FROM THE LOW 30S IN THE FAR NORTH TO LOW 40S IN THE SOUTH. THURSDAY...LOW PRESSURE WILL SLIDE TO NORTHERN LOW MICHIGAN. COLDER AIR WILL CONTINUE TO FILTER INTO THE NORTHWEST HALF OF WISCONSIN BEHIND THE LOW AS GUIDANCE INDICATES THAT MID-LEVEL FGEN INCREASES AGAIN WITHIN A DEVELOPING COMMA HEAD. THIS WILL LEAD TO A BAND OF PRECIP LIFTING NORTH INTO NORTH-CENTRAL WI DURING THE MORNING HOURS. AS MIXED PRECIP CHANGES TO ALL SNOW...2-3 INCHES OF ACCUMULATIONS LOOK POSSIBLE THROUGH THE AFTERNOON HOURS. UNCERTAINTY IS RATHER HIGH CONCERNING LOCATION OF THE BAND...AND ALSO THE IMPACTS ON ROADWAYS SINCE TEMPS WILL LIKELY RISE ABOVE FREEZING INTO THE MID 30S. SINCE MOST OF THE SNOW WILL FALL AFTER THE MORNING COMMUTE...HAVE OPTED TO REFRAIN FROM ISSUING AN ADVISORY...THOUGH THE POSSIBILITY EXISTS THAT ONE WILL BE NEEDED IF THE COMMA HEAD DEVELOPS. ELSEWHERE...THINK PERIODS OF LIGHT SHOWERS WILL DIMINISH LATE IN THE AFTERNOON. HIGHS IN THE MID 30S NORTH TO MID 40S SOUTH. .LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY ISSUED AT 230 PM CDT WED MAR 30 2016 PRECIPITATION CHANCES IN THE LONG-TERM WILL BE TIED TO SHRTWVS RIDING SEWD IN THE STRENGTHENING NWLY UPR FLOW. AS SUCH...TIMING OF THE EVENTS IS LIKELY TO SHIFT SOME WITH EACH SUCCESSIVE SUITE OF MODEL RUNS. PCPN WITH WELL-DEFINED FRONTAL WV COULD LINGER PAST 00Z FRIDAY... THOUGH IT SHOULD TAPER OFF QUICKLY DURING THE EVENING. IT WL BE SOMEWHAT OF A RACE TO SEE WHETHER COLDER AIR ARRIVES QUICKLY ENOUGH TO CHG PCPN TO SNOW BEFORE IT ENDS IN E-C WI...BUT EVEN IF A CHANGEOVER OCCURS DO NOT ANTICIPATE MUCH ACCUMULATION. THERE IS CONSIDERABLE UNCERTAINTY OVER WHETHER OR NOT A SERIES OF SHRTWVS CROSSING THE REGION LATE THU NGT/FRI WL GENERATE PCPN. FORCING IS NOT VERY FOCUSED...SO CARRIED CHC POPS MAINLY ON FRIDAY...WHICH FIT PRETTY WELL WITH THE ECMWF. SHRTWV IN LFQ OF INTENSE UPPER SPEED MAX WL DIG SE ACRS THE REGION LATE FRI NGT INTO SATURDAY. IT IS LIKELY TO SUPPORT A DEEPENING CYCLONE THAT WL TRACK ACRS NRN WI. WENT WITH LIKELY POPS IN THE N/NE...IN REGION OF STRONGEST FORCING. WOULD NOT BE SURPRISED TO GET A COUPLE INCHES OF SNOW ACRS THE N. BUT THINK THE MAIN IMPACT OF THE SYSTEM WL BE WIND. WIND GUSTS OVER 40 KTS APPEAR POSSIBLE ACRS MUCH OF THE AREA SAT...ESP DURING THE AFTN...AS VERY DEEP MIXING COMBINES WITH STG SUBSIDENCE AND LOW-LEVEL CAA. WL BEGIN MENTIONING THE WIND POTENTIAL IN THE HWO. NO SIGNIFICANT CHGS WERE MADE TO THE EXTENDED FORECAST INITIALIZATION GRIDS BASED ON A BROAD BLEND OF GUIDANCE PRODUCTS. SYSTEM SLIDING ESEWD ACRS THE AREA LATE SUN/SUN NGT WL BE TRACKING ALONG VERY STG BAROCLINIC ZONE AND COULD BE A PROLIFIC SNOW PRODUCER. WARM AIR AT THIS TIME OF YEAR SEEMS TO HAVE A WAY OF MAKING IT A LITTLE FARTHER N THAN EARLY MODEL RUNS INDICATE...SO SUSPECT BEST SNOW POTENTIAL WL ONCE AGAIN BE IN THE N. BUT THAT WL NEED TO BE WATCHED CLOSELY THE NEXT COUPLE DAYS. WOULD NOT BE SURPRISED IF SYSTEM ENDS UP PRODUCING ADVISORY-CRITERIA SNOWS. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1203 PM CDT WED MAR 30 2016 A COLD FRONT WILL BE MOVING THROUGH NORTHERN WISCONSIN THIS AFTERNOON BEFORE STALLING OVER SOUTHERN WISCONSIN TONIGHT. AREAS OF LOW PRESSURE WILL TRAVEL ALONG THE FRONT AND BRING PERIODS OF RAIN TO THE TAF SITES. ONCE THIS FIRST ROUND EXITS EARLY THIS AFTERNOON...A SECOND ROUND IS EXPECTED TO ARRIVE THIS EVENING. FINALLY...A THIRD ROUND WILL ARRIVE THURSDAY MORNING. AS THE FRONT PASSES...CEILINGS WILL LIKELY FALL TO LOW MVFR THIS AFTERNOON...AND THEN TO IFR OR LIFR TONIGHT WITH RAIN OR DRIZZLE. THERE IS A SLIGHT CHANCE OF THUNDER SOUTH OF A MARSHFIELD TO GREEN BAY LINE LATE THIS AFTERNOON AND THIS EVENING...BUT PROBABILITIES ARE TOO LOW TO INCLUDE IN THE FORECAST. AS COLDER AIR GRADUALLY FILTERS SOUTH BEHIND THE FRONT...RAIN/DRIZZLE WILL LIKELY CHANGE OVER TO SNOW OVER NORTH-CENTRAL LATE TONIGHT INTO THURSDAY MORNING. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......SKOWRONSKI SHORT TERM.....MPC LONG TERM......SKOWRONSKI AVIATION.......MPC