Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/20/15
AREA FORECAST DISCUSSION
NWS PUEBLO CO
919 PM MDT SUN APR 19 2015
.UPDATE...
ISSUED AT 902 PM MDT SUN APR 19 2015
NARROW BANDS OF SHOWERS CONTINUE TO STREAK OFF THE SOUTHEAST MTS AND
INTO THE ADJACENT INTERSTATE 25 CORRIDOR. THESE HAVE BEEN PRETTY
LOCALIZED SO FAR. NEXT WAVE WILL COME IN AFTER MIDNIGHT ASSOC WITH
DISTURBANCE BACK ACROSS UT/WRN CO. 00Z NAM12 LOOKS CONVECTIVELY
CONTAMINATED...AND WENT WITH A BLEND OF THE LATEST
RAP13...HRRR...AND 18Z GFS. STILL SOME DISCREPANCIES BETWEEN EVEN
THESE MODELS...WITH RAP13 AND HRRR PREFERRING A MORE SOUTHERN
TRACK...ACROSS THE SOUTHWEST MOUNTAINS...SANGRES AND WETS AND
SOUTHERN I-25 CORRIDOR. WHILE GFS...AND THE HEAVY HANDED NAM12
TAKE GREATEST QPF TOTALS ACROSS NORTHERN AND CENTRAL CO...ACROSS
THE PIKES PEAK REGION LATE TONIGHT. HAVE TRENDED TOWARDS THE MORE
SOUTHERN TRACK...AND WILL SEE WHAT 00Z GFS RUN GIVES BEFORE MAKING
DRASTIC CHANGES. OVERALL FORECAST TRENDS POPS UPWARDS INTO THE SCT
CATEGORY LATE TONIGHT...WITH POPS TRENDING DOWNWARD FROM WEST TO
EAST MONDAY MORNING. -KT
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 243 PM MDT SUN APR 19 2015
CURRENTLY...THE UPPER TROUGH HAS MOVED WELL EAST INTO EASTERN KS
THIS AFTN...AND STRONG N-NW WINDS ON THE BACKSIDE OF THE SYSTEM HAVE
BEGUN TO MELLOW AS A RESULT. BRISK WINDS WITH GUSTS UP TO 30 MPH
CONTINUE FROM APPROX LHX AND EASTWARD. UNDER INTERMITTENT CLOUD
COVER WITH ABUNDANT CLOUD BREAKS...TEMPS HAVE WARMED INTO THE 40S TO
LOWER 50S FOR MOST LOWER ELEVATIONS LOCATIONS.
TONIGHT AND TOMORROW...NW FLOW ALOFT HAS SETTLED IN AND WILL BE THE
MAIN STORY OVER THE NEXT FEW DAYS. ONE UPPER WAVE IS NEARING THE
STATE...AND IS EXPECTED TO SPARK ISOLATED TO SCATTERED SHOWERS AND
STORMS OVER THE MTS AND NEARBY PLAINS LATE THIS AFTN AND EVE. AS THE
NIGHT PROGRESSES...MODELS INDICATE THAT THIS WAVE WILL CONTINUE
EAST...PROMOTING MORE CONVECTION OVER THE PALMER DVD AND RAMPART
RANGE AFTER MIDNIGHT. THIS WAS A BIT DIFFERENT THAN WHAT WAS IN THE
FORECAST GRIDS...SO INCREASED POPS IN THOSE LOCATIONS. TOMORROW AFTN
SHOWERS AND STORMS ARE FORECAST TO REDEVELOP OVER THE HIGHER TERRAIN
FOLLOWING A MORE DIURNAL CONVECTIVE PATTERN. THE CHALLENGE TONIGHT
WILL BE MIN TEMPS. TEMPS ARE HOVERING NEAR THE FREEZING MARK...AND
WHETHER THEY STAY JUST ABOVE OR DIP BELOW THAT MARK WILL BE
DETERMINED BY CLOUD COVER. THE WINDS ARE ALREADY STARTING TO DIE
DOWN...SO SIGNIFICANT BREAKS IN THE CLOUD COVER WILL ALLOW MORE
EFFICIENT RADIATIONAL COOLING. HAVE OPTED TO NOT ISSUE ANY SORT OF
FREEZE HIGHLIGHT AT THIS TIME SINCE THE OFFICIAL START IS MAY
1...BUT SOME ATTENTION TO OUTDOOR PLANTS MAY BE IN ORDER FOR
TONIGHT. AS FOR TOMORROW...AFTN MAX TEMPS SHOULD BE ON PAR OR A FEW
DEGREES WARMER THAN THOSE RECORDED TODAY. MOORE
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 243 PM MDT SUN APR 19 2015
...BUSY WEATHER PATTERN DURING THIS PERIOD...
WEATHER WILL LIKELY BE A BIT ACTIVE DURING THE EXTENDED PERIOD AS A
FEW DISTURBANCES WILL KEEP AREAS OF PRECIP AND THUNDER OVER THE
REGION. ON FRIDAY...WE MAY SEE SOME ORGANIZED ROTATING CONVECTION
ON THE PLAINS.
MONDAY EVENING A DISTURBANCE WILL BE MOVING ACROSS THE REGION ND
THIS SHOULD ALLOW FOR SOME SCATTERED SHOWERS AND STORMS...MAINLY
ALONG THE CO/NM BORDER DURING THE EVENING.
ON TUESDAY...MIDLVL RIDGE BUILDS TO THE NW OF THE FCST AREA. A WEAK
COOL FRONT IS EXPECTED TO MOVE DOWN THE PLAINS DURING THE DAY AND
THIS MAY ENHANCE THE SHOWER THREAT OVER THE PLAINS TUES
EVENING...ESPECIALLY ALONG THE PLAINS/MTN INTERFACE AND ONCE AGAIN
ALONG THE CO/NM BORDER.
THIS FRONT IS LIKELY GOING TO GET HUNG UP ALONG THE CO/NM BORDER.
THIS WILL KEEP THE PLAINS IN MOIST UPSLOPE FLOW ON WED. ALTHOUGH
FLOW WILL BE RELATIVELY WEAK ALOFT...WE SHOULD SEE ISOLD/SCTD
THUNDER ON THE PLAINS ONCE AGAIN WED AFTERNOON AND EVENING WITH
SOME SHOWERS AND STORMS OVER THE MTNS.
THU AND FRI...
THESE TWO DAYS APPEAR TO BE A BIT MORE ACTIVE AS A WEATHER SYSTEM
MOVES E-NE ACROSS THE SW CONUS AND OVER THE REGION LATER ON
FRIDAY. MOISTURE WILL BE ON THE INCREASE AS REINFORCING COOL
FRONTS WORK SOUTH ALONG THE PLAINS BRINGING UPSLOPE FLOW AND LLVL
MOISTURE. SHEAR AND INSTABILITY WILL BE ON THE INCREASE SO STORMS
THU AFTERNOON MAY BE A BIT STRONGER...AND ON FRIDAY WE MAY SEE
ENOUGH PARAMETERS COME INTO PLAY THAT WE WILL HAVE A ORGANIZED SVR
WEATHER THREAT. OVERALL...THESE TWO DAYS SHOULD BE WET GIVEN THE
FAVORABLE FORCING OVER THE REGION. THIS SYSTEM WILL ALSO LIKELY
BRING MORE HIGH MTN SNOWS...ESPECIALLY TO THE SAN JUANS AND
POSSIBLY SANGRE DE CRISTO MTNS.
FOR THE WEEKEND...MODEST W-NW FLOW ALOFT WILL PREVAIL. GFS HAS A LEE
TROUGH ALONG THE BORDER WHILE EC STILL HAS WEAK UPSLOPE FLOW OVER
THE FCST AREA. WE WILL LIKELY SEE SOME SHOWERS AND STORMS FOR THE
WEEKEND BUT WILL NOT BE AS MANY AS ON THU AND FRI.
AS FOR TEMPS THROUGH THE PERIOD...EXPECT MAX TEMPS ON THE PLAINS
TO RANGE FROM THE MID 60S TO MID 70S. DO NOT EXPECT ANY FIRE WX
ISSUES GIVEN THE RELATIVELY COOL TEMPS AND HIGHER RH AIR OVER THE
DISTRICT. /HODANISH
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 243 PM MDT SUN APR 19 2015
MAINLY VFR CONDITIONS EXPECTED AT COS...PUB AND ALS OVER THE NEXT 24
HOURS. GUSTY NORTH WINDS 20-30 KTS EXPECTED THROUGH 00Z OVER
PORTIONS OF THE EASTERN PLAINS...ROUGHLY FROM KLHX AND
EASTWARD...AND WILL CONTINUE TO WEAKEN THROUGH THE EVENING. ISOLATED
TO LOW END SCATTERED SHOWERS ARE FORECAST TO DEVELOP OVER THE MTS
THIS EVE...PRODUCING DETERIORATED CONDITIONS OVER MT PASSES. SHOWERS
ARE EXPECTED TO DEVELOP AROUND 09Z TONIGHT OVER THE PALMER
DVD...RAMPART RANGE AND IN THE VCNTY KCOS...PRODUCING INTERMITTENT
MVFR CONDITIONS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KT
SHORT TERM...MOORE
LONG TERM...HODANISH
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
328 PM MDT SAT APR 18 2015
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 325 PM MDT SAT APR 18 2015
THE LOW PRESSURE RESPONSIBLE FOR THE MUCH NEEDED PRECIP OVER THE
LAST FEW DAYS IS NOW LOCATED OVER THE FRONT PLAINS WHILE CYCLONIC
FLOW CONTINUES TO PUMP IN MOISTURE FROM THE NORTH TO SOUTH. THIS
FLOW STARTS IN NERN WY AND THE PLUME REACHES AS FAR SOUTH AS THE
SAN JUANS. SNOW AND RAIN HAS FALLEN MUCH OF THE DAY UNDER THIS
PLUME OF MOISTURE AND WILL CONTINUE TO DO SO THROUGH THIS EVENING.
CURRENT WINTER HIGHLIGHTS LOOK GOOD SO NO CHANGES THERE. AN UPPER
LEVEL DISTURBANCE OVER SRN CANADA IS TRAILING A TROUGH THAT IS
CAUSING THE AREA OF LOW PRESSURE TO KEEP MOVING EWRD. THE REASON
THIS IS HAPPENING SO SLOWLY IS THE LACK OF ANY STRONG JET FEATURES
TO REALLY GET THIS SYSTEM MOVING. EVEN SO...THE CLOUD SHIELD/PLUME
WILL BRING MORE PRECIP TO THE AREA AS THE ATTENDANT LOW PRESSURE
MEANDERS EAST. BY MIDNIGHT...PRECIP WILL FAVOR THE NRN AND CENTRAL
MTNS ALONG WITH THE FLATTOPS DUE TO THEIR FAVORABLE LOCATION SO
ADDITIONAL ACCUMULATIONS STILL POSSIBLE UP THERE. THE REST OF THE
CWA MAY SEE AN ODD SHOWER OR TWO BUT NOTHING TOO SIGNIFICANT.
BY SUNDAY...THE CANADIAN LOW WILL BE JUST TO THE NORTH OF
MINNESOTA WHILE HIGH PRESSURE BUILDS INTO THE PACNW. THIS WILL
CAUSE OUR CWA TO BE SANDWICHED BETWEEN THESE TWO FEATURES. WEAK
PIECES OF ENERGY WILL DROP DOWN FROM THE NW POSSIBLY CAUSING SOME
PRECIP FOR THE CWA. THE GFS HIGHLIGHTING TWO DISTINCT WAVES...ONE
SUNDAY EVENING AND ANOTHER MONDAY MORNING. THE NAM12 ONLY SHOWING
SOME SPOTTY SHOWERS AT BEST WITH SOME CONVECTION THROWN IN. THE
HRRR AND RAP SHOWING MUCH LESS IN THE WAY OF PRECIP. THIS ALL
MEANS UNSETTLED WX WILL CONTINUE BUT WITH MUCH MORE DEFINITIVE
BREAKS BETWEEN DISTURBANCES. FORECAST BRINGS MOSTLY BENIGN
WEATHER SUNDAY WITH INCREASING CHANCES FOR PRECIP FROM
MIDAFTERNOON ONWARDS...MAINLY FAVORING THE CONTINENTAL DIVIDE.
TEMPS WILL WARM UP CONSIDERABLY TOMORROW THOUGH STILL REMAIN 5 TO
10 DEGREES BELOW NORMAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 325 PM MDT SAT APR 18 2015
UNSETTLED NW FLOW IS EXPECTED MONDAY AND TUESDAY. AN EMBEDDED WAVE
SHOULD FOCUS THE BEST CHANCE OF SHOWERS OVER THE NORTHERN AND
CENTRAL MOUNTAINS MONDAY AFTERNOON AND EVENING. DAYTIME INSTABILITY
WILL KEEP ISOLATED TO SCATTERED SHOWERS OVER THE MTNS ON TUESDAY.
TEMPORARY RIDGING DEVELOPS OVER THE AREA BY MIDWEEK AS A TROUGH
FORMS ALONG THE WEST COAST...WITH AN UPPER LOW OVER SRN CA BY THU
MORNING. ENOUGH RESIDUAL MOISTURE LINGERS FOR A FEW AFTERNOON
SHOWERS OR THUNDERSTORMS. FLOW ALOFT BECOMES SOUTHWEST...AND THE
SRN CA LIFTS ACROSS THE FOUR CORNERS/DESERT SOUTHWEST THU NIGHT
AND FRI MORNING. TIMING AND TRACK A BIT DIFFERENT BETWEEN MODELS
BUT STILL LOOKING LIKE A BETTER CHANCE OF PRECIPITATION WITH SOME
THUNDERSTORMS LATE NEXT WEEK. BOOSTED POPS FOR THU AFTERNOON
THROUGH FRI OVER THE BLENDED FORECAST GUIDANCE AS A RESULT.
GFS AND ECMWF SOLUTIONS CONTINUE TO DIVERGE ON SATURDAY. ECWMF MORE
AMPLIFIED AS IT DIGS A PAC NW TROUGH TO THE SRN GREAT BASIN BY
SATURDAY...RESULTING IN DOWNSTREAM RIDGING AND SW FLOW OVER OUR
AREA. GFS DROPS SOME ENERGY FROM THE PAC NW TROUGH DOWN THE WEST
COAST BUT SENDS MORE OF IT ACROSS THE NRN ROCKIES WITH WESTERLY FLOW
ACROSS UT/CO. WILL FOLLOW THE BLENDED GUIDANCE FOR SAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1137 AM MDT SAT APR 18 2015
WIDESPREAD MVFR/IFR WILL CONTINUE FOR MUCH OF THE DAY AS LOW
CLOUDS AND PRECIP STREAM DOWN FROM THE NORTHWEST. KCNY AND
KVEL...AND KDRO WILL SLOWLY IMPROVE THROUGH THE DAY AS THE LOW
OVER THE FRONT RANGE CONTINUES TO DRIFT EASTWARD. REMAINING TAF
SITES WILL SEE THE PRECIP AND CIGS THROUGH 06Z WITH CONDITIONS
SLOWLY IMPROVING AFTER THAT. OCCNL LULLS ARE POSSIBLE HOWEVER. ALL
HIGHER TERRAIN WILL BE OBSCURED TODAY. NO CONCERNS WITH WINDS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT FOR COZ009-010-
012-017-018.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ003-
004-013.
UT...NONE.
&&
$$
SHORT TERM...TGR
LONG TERM...JAD
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
322 PM MDT SAT APR 18 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 322 PM MDT SAT APR 18 2015
UPPER LEVEL LOW HAS MADE VERY LITTLE EASTWARD PROGRESS TODAY AND
IS STILL LOCATED OVER SOUTHWEST WASHINGTON COUNTY...BASED ON THE
RECENT MOTION OF RADAR ECHOES. AFTERNOON HEATING AND COLD
TEMPERATURES ALOFT HAVE DE-STABILIZED THE AIRMASS ENOUGH FOR
EMBEDDED THUNDERSTORMS TO DEVELOP OVER THE FAR NORTHEAST PLAINS.
MOUNTAIN AREAS HAVE BEEN PICKING UP SCATTERED SNOW SHOWERS...BUT
NOT MUCH NEW SNOW ACCUMULATION...BASED ON WEB CAMERAS AND SNOTEL
DATA.
THE SHOWERS AND THUNDERSTORMS THIS EVENING SHOULD TAPER IN THE
EVENING...WITH THE LOSS OF DAYTIME HEATING. ADDITIONAL SHOWERS ARE
EXPECTED OVERNIGHT AS THE UPPER LOW MOVES EASTWARD AND THE RETURN
FLOW ON THE BACKSIDE OF THE LOW MOVES OUT OF THE MOUNTAINS AND
ACROSS THE PLAINS. THE NAM AND RAP FORECASTS HAVE RAIN OCCURRING
THROUGH MOST OF THE NIGHT AND THEN A DECREASE IN SHOWER ACTIVITY
BY MIDDAY SUNDAY. TEMPERATURES OVERNIGHT WILL DROP TO THE MID AND
UPPER 30S ON THE PLAINS WHICH MAY BE COOL ENOUGH FOR SOME SNOW TO
FALL. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED THOUGH. SUNDAY
WILL BE A MIX OF MORNING SHOWERS AND THEN DECREASING CLOUDS IN THE
AFTERNOON. STRONG INSOLATION SHOULD ALLOW AFTERNOON TEMPERATURES
TO CLIMB INTO THE LOWER 50S. MOUNTAIN AREAS COULD SEE SCATTERED
SNOW SHOWERS CONTINUE AS WE REMAIN UNDER MOIST NORTHWESTERLY FLOW.
SNOW ACCUMULATIONS SHOULD BE LESS THAN 3 OR 4 INCHES.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 322 PM MDT SAT APR 18 2015
A COLD NORTHWEST FLOW ON THE BACK SIDE OF EXITING
LONG WAY UPPER TROUGH DRIVES A CLIPPER TYPE DISTURBANCE SOUTHWARD
OUT OF WYOMING SUNDAY NIGHT AND MONDAY MORNING ACCORDING TO
DETERMINISTIC MODELS. SYSTEM APPEARS TO PACK ADJACENT COLD
AIR...MOISTURE AND OROGRAPHIC LIFT TO PRODUCE ANOTHER ROUND OF LIGHT
SNOW ACCUMULATION IN THE HIGHER MTN RANGES. MTN PASSES AND EXPOSED
NORTHWEST SLOPES COULD SEE ANYWHERE FROM 2-5 INCHES OF ADDITIONAL
SNOW ACCUMULATION BY MONDAY EVENING. WETBULB TEMP IS PROGGED TO BE
LOW ENOUGH FOR A RAIN/SNOW MIX ON THE NEAR BY PLAINS SUNDAY
EVENING...AND POSSIBLY ALL SNOW LATE SUNDAY NIGHT INTO MONDAY
MORNING. THIS SYSTEM DOES NOT LOOK LIKE A BIG PRECIP MAKER FOR THE
PLAINS AND ANY SNOW THAT FALLS AT LOWER ELEVATIONS SHOULD NOT
ACCUMULATE.
MODELS SHOW THIS DISTURBANCE QUICKLY MOVING OUT OF THE FCST AREA
DURING THE DAY MONDAY AND WITH LOW LEVEL WINDS TURNING WESTERLY...
TEMPS SHOULD MANAGE TO REACH THE 50S ON THE PLAINS WITH SUNSHINE
RETURNING LATE IN THE DAY.
MODELS SHOW A BREAK IN THE COOL AND WET NWLY FLOW PATTERN TUESDAY
INTO WEDNESDAY WHEN A DIRTY SHORTWAVE UPPER RIDGE OVER THE GREAT
BASIN WORKS ITS WAY ACROSS COLORADO. GFS AND NAM INDICATE A FAIR
AMOUNT OF MID AND HIGH LEVEL MOISTURE WITH THIS RIDGE...SUFFICIENT
TO WARRANT A CHANCE OF RAIN/SNOW SHOWERS IN THE HIGH COUNTRY ON
TUESDAY AND AGAIN BY WEDNESDAY AFTERNOON. LATE DAY SHOWERS ON
WEDNESDAY COULD BE ACCOMPANIED BY SOME THUNDER DURING THE WARMEST
TIME OF THE DAY. ON THE PLAINS...DRY CONDITIONS WILL PREVAIL WITH A
PREVAILING W-SWLY LOW LEVEL FLOW. AS A RESULT...TEMPS REBOUND WITH
AFTN READINGS 1-5 DEG F ABOVE AVERAGE ON TUES AND 5-10 DEG ABOVE
AVERAGE BY WED. LATE ON WEDNESDAY UPPER RIDGE OVER COLORADO APPEARS
TO FLATTEN OUT WITH MODELS SHOWING A WEAK SHORTWAVE TROUGH ZOOMING
UP FROM THE DESERT SOUTHWEST AND THEN ROUNDING THE TOP OF RIDGE.
SHOULD THIS HAPPEN...CAN SEE PRECIP CHANCES ON THE RISE AGAIN ACRS
THE CWA WITH RAIN/SNOW IN THE HIGH COUNTRY AND RAIN SHOWERS ON THE
PLAINS. THERE/S ALSO A SLIGHT CHANCE OF T-STORMS BY EVENING.
THURSDAY AND BEYOND...LARGE SCALE FLOW PATTERN OVER THE WESTERN
CONUS IS PROGGED TO BECOME MORE LIVELY WITH YET ANOTHER LARGE SCALE
UPPER TROUGH MAKING ITSELF FELT IN THE GREAT BASIN WEDNESDAY INTO
THURSDAY AND ACROSS THE NORTH CENTRAL AND NORTHEAST THURSDAY AND
FRIDAY. WITH AS MUCH MOISTURE AND COOL AIR WITH THIS SYSTEM...WILL
CONTINUE LOW POPS FOR ALL AREAS RIGHT THROUGH SATURDAY.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z SUNDAY LATE AFTERNOON)
ISSUED AT 322 PM MDT SAT APR 18 2015
SHOWER ACTIVITY IS EXPECTED TO CONTINUE MOVING INTO THE DENVER
AREA FROM THE NORTH THROUGH EARLY THIS EVENING. ISOLATED
THUNDERSTORMS WILL BE POSSIBLE ALONG WITH BRIEF HEAVY RAIN AND
GUSTY WINDS. THE THREAT OF THUNDER WILL CONTINUE THROUGH ABOUT 8
PM MDT. ADDITIONAL RAIN SHOWERS ARE EXPECTED OVERNIGHT AS THE
UPPER LEVEL SYSTEM EXITS THE STATE...DRAGGING AN AREA OF MOIST AIR
BEHIND IT. SHOWER ACTIVITY WILL MOVE OUT OF THE NORTH THROUGH THE
OVERNIGHT HOURS AND MAY MIX WITH SNOW AT TIMES. NO SIGNIFICANT
ACCUMULATIONS ARE ANTICIPATED. SHOWER ACTIVITY WILL BE TAPERING
OFF TOMORROWWITH IMPROVING CONDITIONS THROUGH THE AFTERNOON.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DANKERS
LONG TERM...BAKER
AVIATION...DANKERS
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1023 AM MDT SAT APR 18 2015
.UPDATE...
ISSUED AT 1023 AM MDT SAT APR 18 2015
NOT MANY CHANGES TO THE FORECAST AT THIS TIME. THE CENTER OF THE
UPPER LOW HAS MOVED OVER LINCOLN COUNTY WITH A VORTICITY CENTER
HELPING TO KICK OFF SHOWERS AND A FEW THUNDERSTORMS EARLIER THIS
MORNING. AS THE VORTICITY CENTER CONTINUES ROTATING OVER THE
PLAINS...IT WILL COMBINE WITH SOME DAYTIME HEATING TO CONTINUE
PRODUCING SHOWERY ACTIVITY THAT MAY EVENTUALLY MAKE IT BACK TO THE
FOOTHILLS. ANOTHER BAND OF MOISTURE IN THE DEFORMATION REGION TO
THE NORTHWEST OF THE UPPER LOW WILL CONTINUE ROTATING INTO THE
NORTHERN MOUNTAINS THROUGH THE AFTERNOON. ADDITIONAL ACCUMULATING
SNOWFALL SHOULD CONTINUE THROUGH MUCH OF THE DAY WITH AMOUNTS UP
TO A FEW INCHES POSSIBLE. LATE MORNING FORECAST UPDATE WILL
CONTAIN ONLY MINOR CHANGES...CHIEFLY ADDING THE MENTION OF
ISOLATED AFTERNOON THUNDERSTORMS TO THE PLAINS THROUGH THE LATE
MORNING AND AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 512 AM MDT SAT APR 18 2015
UPPER LOW NEAR WALSENBURG AT THIS TIME TRACKING SLOWLY EAST. DRY
SLOT HAS CURLED AROUND ACROSS MOST OF EASTERN COLORADO WITH
MOISTURE WRAPPING BACK FROM WYOMING INTO THE COLORADO MOUNTAINS.
AT THIS TIME THE BACK PART OF THIS SYSTEM DOES NOT HAVE STRONG
LIFT WITH IT...BUT THIS IS EXPECTED TO INCREASE DURING THE DAY AS
EVERYTHING CONTINUES TO SPIN AROUND THE LOW CENTER MOVING SLOWLY
EAST. A COMPLEX PATTERN...BUT THE GOOD NEWS IS THE MODELS HAVE
PRETTY GOOD AGREEMENT ON THE BIG PICTURE. DETAILS OF JUST WHERE
THE BANDING STRUCTURE AND CONVECTION ARE VARY CONSIDERABLY. LIKING
THE HRRR PRESENTATION OF THE DEVELOPING BACK EDGE SNOW BAND ACROSS
THE MOUNTAINS...ROUGHLY FROM LARAMIE TOWARD RIFLE THIS MORNING.
HARD TO SAY IF THE NORTH CENTRAL MOUNTAINS WILL BE IN THE BEST OF
THIS...OR IF IT WILL STAY FURTHER WEST WITH THE DRIER AIR CURLING
BACK OVER THE FRONT RANGE. I DID INCREASE THE POPS FOR THE
MOUNTAINS...HELD OFF ON INCREASING AMOUNTS TOO MUCH AS THE SNOW
MAY TEND TOWARD LIGHT SHOWERS IN THE VALLEYS WITH A STEADY
BACKGROUND OF LIGHT OROGRAPHIC SNOW. IF THAT BAND WOBBLES FURTHER
EAST AN ADVISORY MAY BE NEEDED. MEANWHILE ON THE PLAINS THERE IS
DRIER AIR ALOFT...BUT THE LOW LEVELS REMAIN MOIST AND THE COLD
POOL ALOFT WILL BE OVER THIS AREA...AND THERE WILL BE SOME LIFT
FROM THE TIP OF THE WARM ADVECTION NEAR THE LOW CENTER. CONVECTION
SHOULD INCREASE THROUGH THE DAY. NOT AS MUCH OF A THUNDERSTORM
RISK TODAY...CAPES LIKELY AROUND 300 J/KG AROUND DENVER AND 600
NEAR THE EASTERN BORDER. I WOULD SAY NEGLIGIBLE SEVERE THREAT
EXCEPT FOR THE COLD TEMPERATURES...COULD BE SOME HAIL OUT EAST BUT
IT SHOULD BE HARD TO GET LARGE HAIL.
FOR TONIGHT THE BACK EDGE BAND WILL TRANSLATE ACROSS OUR AREA AS
THE LOW MOVES EAST. THIS SHOULD BRING A BETTER CHANCE OF
SHOWERS. NORTH WINDS ALSO INCREASING...WHICH COULD WARM/DRY AREAS
NORTH OF DENVER BUT ENHANCE THE THREAT OF SNOW SOUTH OF DENVER.
THE NORTH WIND SHOULD ALSO BRING A FEW DEGREES OF
COOLING...LOWERING SNOW LEVELS BACK DOWN TO 5-6 THOUSAND FEET.
HOWEVER AIR TEMPERATURES WILL STILL BE ABOVE FREEZING IN MOST
AREAS...SO STILL EXPECTING LITTLE IMPACT FOR THE METRO AREA.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 512 AM MDT SAT APR 18 2015
THERE IS WEAK TO MODERATE NORTHWESTERLY JET LEVEL FLOW OVER THE
CWA SUNDAY THROUGH MONDAY NIGHT. THERE IS WEAK DOWNWARD SYNOPTIC
SCALE ENERGY FOR THE CWA SUNDAY...THEN BENIGN ENERGY SUNDAY NIGHT
THROUGH MONDAY NIGHT. THERE IS NORTHERLY FLOW IN THE LOWER LEVELS
ON SUNDAY...WITH WEAKER NORTHEASTERLIES SUNDAY NIGHT. BOUNDARY
LAYER WINDS ARE NORTHWESTERLY ON MONDAY...THEN A HINT AT NORMAL
DRAINAGE PATTERNS MONDAY NIGHT. FOR MOISTURE...THERE IS PLENTY FOR
THE CWA SUNDAY AND SUNDAY NIGHT...THE NAM BEING THE DRIEST. THERE
IS QUITE A BIT OF MOISTURE STILL AROUND BOTH MONDAY AND MONDAY
NIGHT...THE GFS BEING THE WETTEST. THERE IS A BIT OF CAPE OVER THE
FAR SOUTHWEST FORECAST AREA LATE DAY SUNDAY DAY. THERE IS A BIT
MORE CAPE OVER ALL THE HIGH COUNTRY LATE DAY MONDAY...BUT STILL
PRETTY MEAGER AMOUNTS. THE QPF FIELDS HAVE SOME MEASURABLE
PRECIPITATION MOSTLY OVER THE WESTERN TWO-THIRDS OF THE CWA
SUNDAY AFTERNOON INTO MONDAY EVENING. FOR POPS...20-50%S ARE GOOD
SUNDAY INTO MONDAY...THE LOWER NUMBERS FOR THE PLAINS. FOR
TEMPERATURES...SUNDAY`S HIGHS ARE A BIT COLDER THAN TODAY`S BEHIND
THE COLD FRONT LATE TONIGHT...EARLY SUNDAY MORNING. MONDAY`S HIGHS
ONLY WARM UP 1-2 C FROM SUNDAY`S. FOR THE LATER DAYS...TUESDAY
THROUGH FRIDAY...THERE IS AN UPPER RIDGE TUESDAY THROUGH THURSDAY
NOW ON THE MODELS. THE NEXT UPPER TROUGH LOOKS WEAKER THAN IT DID
ON YESTERDAY`S 00Z RUNS AND IT COMES THROUGH THURSDAY NIGHT AND
FRIDAY.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 1023 AM MDT SAT APR 18 2015
THE COOL...MOIST AND SLIGHTLY UNSTABLE AIRMASS WILL REMAIN OVER
NORTHEAST COLORADO THROUGH THIS AFTERNOON AND EVENING. MAY NEED TO
MENTION SOME THUNDERSTORMS AT THE DENVER AREA AIRPORTS THROUGH THE
AFTERNOON. WARMER DEW POINTS ARE MOVING INTO DENVER FROM THE
NORTHEAST SO THE THREAT OF SNOW IS GOING DOWN FOR THE REST OF THIS
AFTERNOON. STILL MAY SEE A MIX OF RAIN AND SNOW LATER TONIGHT AS
SHOWERS CONTINUE AND TEMPERATURES COOL DOWN. SHOWERS COULD BE LONG
LIVED THROUGH THE EVENING AS THE UPPER LOW PULLS OUT OF COLORADO
AND MOISTURE ON THE NORTHWEST SIDE OF THE LOW ROTATES INTO THE
DENVER AREA.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DANKERS
SHORT TERM...GIMMESTAD
LONG TERM...RJK
AVIATION...DANKERS
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
512 AM MDT SAT APR 18 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 512 AM MDT SAT APR 18 2015
UPPER LOW NEAR WALSENBURG AT THIS TIME TRACKING SLOWLY EAST. DRY
SLOT HAS CURLED AROUND ACROSS MOST OF EASTERN COLORADO WITH
MOISTURE WRAPPING BACK FROM WYOMING INTO THE COLORADO MOUNTAINS.
AT THIS TIME THE BACK PART OF THIS SYSTEM DOES NOT HAVE STRONG
LIFT WITH IT...BUT THIS IS EXPECTED TO INCREASE DURING THE DAY AS
EVERYTHING CONTINUES TO SPIN AROUND THE LOW CENTER MOVING SLOWLY
EAST. A COMPLEX PATTERN...BUT THE GOOD NEWS IS THE MODELS HAVE
PRETTY GOOD AGREEMENT ON THE BIG PICTURE. DETAILS OF JUST WHERE
THE BANDING STRUCTURE AND CONVECTION ARE VARY CONSIDERABLY. LIKING
THE HRRR PRESENTATION OF THE DEVELOPING BACK EDGE SNOW BAND ACROSS
THE MOUNTAINS...ROUGHLY FROM LARAMIE TOWARD RIFLE THIS MORNING.
HARD TO SAY IF THE NORTH CENTRAL MOUNTAINS WILL BE IN THE BEST OF
THIS...OR IF IT WILL STAY FURTHER WEST WITH THE DRIER AIR CURLING
BACK OVER THE FRONT RANGE. I DID INCREASE THE POPS FOR THE
MOUNTAINS...HELD OFF ON INCREASING AMOUNTS TOO MUCH AS THE SNOW
MAY TEND TOWARD LIGHT SHOWERS IN THE VALLEYS WITH A STEADY
BACKGROUND OF LIGHT OROGRAPHIC SNOW. IF THAT BAND WOBBLES FURTHER
EAST AN ADVISORY MAY BE NEEDED. MEANWHILE ON THE PLAINS THERE IS
DRIER AIR ALOFT...BUT THE LOW LEVELS REMAIN MOIST AND THE COLD
POOL ALOFT WILL BE OVER THIS AREA...AND THERE WILL BE SOME LIFT
FROM THE TIP OF THE WARM ADVECTION NEAR THE LOW CENTER. CONVECTION
SHOULD INCREASE THROUGH THE DAY. NOT AS MUCH OF A THUNDERSTORM
RISK TODAY...CAPES LIKELY AROUND 300 J/KG AROUND DENVER AND 600
NEAR THE EASTERN BORDER. I WOULD SAY NEGLIGIBLE SEVERE THREAT
EXCEPT FOR THE COLD TEMPERATURES...COULD BE SOME HAIL OUT EAST BUT
IT SHOULD BE HARD TO GET LARGE HAIL.
FOR TONIGHT THE BACK EDGE BAND WILL TRANSLATE ACROSS OUR AREA AS
THE LOW MOVES EAST. THIS SHOULD BRING A BETTER CHANCE OF
SHOWERS. NORTH WINDS ALSO INCREASING...WHICH COULD WARM/DRY AREAS
NORTH OF DENVER BUT ENHANCE THE THREAT OF SNOW SOUTH OF DENVER.
THE NORTH WIND SHOULD ALSO BRING A FEW DEGREES OF
COOLING...LOWERING SNOW LEVELS BACK DOWN TO 5-6 THOUSAND FEET.
HOWEVER AIR TEMPERATURES WILL STILL BE ABOVE FREEZING IN MOST
AREAS...SO STILL EXPECTING LITTLE IMPACT FOR THE METRO AREA.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 512 AM MDT SAT APR 18 2015
THERE IS WEAK TO MODERATE NORTHWESTERLY JET LEVEL FLOW OVER THE
CWA SUNDAY THROUGH MONDAY NIGHT. THERE IS WEAK DOWNWARD SYNOPTIC
SCALE ENERGY FOR THE CWA SUNDAY...THEN BENIGN ENERGY SUNDAY NIGHT
THROUGH MONDAY NIGHT. THERE IS NORTHERLY FLOW IN THE LOWER LEVELS
ON SUNDAY...WITH WEAKER NORTHEASTERLIES SUNDAY NIGHT. BOUNDARY
LAYER WINDS ARE NORTHWESTERLY ON MONDAY...THEN A HINT AT NORMAL
DRAINAGE PATTERNS MONDAY NIGHT. FOR MOISTURE...THERE IS PLENTY FOR
THE CWA SUNDAY AND SUNDAY NIGHT...THE NAM BEING THE DRIEST. THERE
IS QUITE A BIT OF MOISTURE STILL AROUND BOTH MONDAY AND MONDAY
NIGHT...THE GFS BEING THE WETTEST. THERE IS A BIT OF CAPE OVER THE
FAR SOUTHWEST FORECAST AREA LATE DAY SUNDAY DAY. THERE IS A BIT
MORE CAPE OVER ALL THE HIGH COUNTRY LATE DAY MONDAY...BUT STILL
PRETTY MEAGER AMOUNTS. THE QPF FIELDS HAVE SOME MEASURABLE
PRECIPITATION MOSTLY OVER THE WESTERN TWO-THIRDS OF THE CWA
SUNDAY AFTERNOON INTO MONDAY EVENING. FOR POPS...20-50%S ARE GOOD
SUNDAY INTO MONDAY...THE LOWER NUMBERS FOR THE PLAINS. FOR
TEMPERATURES...SUNDAY`S HIGHS ARE A BIT COLDER THAN TODAY`S BEHIND
THE COLD FRONT LATE TONIGHT...EARLY SUNDAY MORNING. MONDAY`S HIGHS
ONLY WARM UP 1-2 C FROM SUNDAY`S. FOR THE LATER DAYS...TUESDAY
THROUGH FRIDAY...THERE IS AN UPPER RIDGE TUESDAY THROUGH THURSDAY
NOW ON THE MODELS. THE NEXT UPPER TROUGH LOOKS WEAKER THAN IT DID
ON YESTERDAY`S 00Z RUNS AND IT COMES THROUGH THURSDAY NIGHT AND
FRIDAY.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 512 AM MDT SAT APR 18 2015
CONDITIONS WILL BE VARIABLE TODAY AS THERE WILL BE SCATTERED
SHOWERS. FOR THE MORNING THERE WILL BE AREAS OF MVFR CEILINGS WITH
A FEW PATCHES OF IFR. CEILINGS SHOULD BE HIGHER BY LATE
MORNING...BUT STILL EXPECT LOCALIZED MVFR NEAR SHOWERS. THERE MAY
BE LOWER CONDITIONS AGAIN THIS EVENING WHEN THERE IS A BETTER
CHANCE OF SHOWERS...MAINLY MVFR BUT A SLIGHT CHANCE OF IFR
CONDITIONS. WINDS WILL BE LIGHT AND MAINLY FROM THE NORTH OR
NORTHWEST...BUT WITH SOME VARIABILITY. SNOW MAY MIX WITH THE RAIN
TONIGHT...BUT NO RUNWAY ACCUMULATION IS EXPECTED AT THE DENVER
AREA AIRPORTS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GIMMESTAD
LONG TERM...RJK
AVIATION...GIMMESTAD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1120 PM MDT FRI APR 17 2015
.UPDATE...
ISSUED AT 919 PM MDT FRI APR 17 2015
UPDATED TO MODIFY POPS BASED ON 00Z GUIDANCE...FOCUSING
HIGHEST CHANCES OVER THE PIKES PEAK REGION AND UPPER ARKANSAS
AND CONTDVD NORTH OF HIGHWAY 50. CUT BACK ON POPS TO THE SOUTH
BUT WILL LEAVE ISOLD-SCT CHANCES OUT FOR THE HIGHER TERRAIN WITH
THE UPPER LOW OVERHEAD.
UPDATE ISSUED AT 844 PM MDT FRI APR 17 2015
MADE SOME ADJUSTMENTS TO THE WINTER HEADLINES BASED ON
OBS...TRENDS AND LATEST MODEL GUIDANCE. LOOKS LIKE THE HEAVIEST
AND MOST PERSISTENT PRECIP WILL BE OVER THE MTS NORTH OF HGWY
50 TONIGHT AND TOMORROW. SO...HAVE CANCELED THE ADVISORIES FOR THE
SANGRES AND WETS. EXTENDED PIKES PEAK AND THE SAWATCH TIL 00Z SUN
SINCE IT LOOKS LIKE PERIODS OF MODERATE SNOW WILL CONTINUE
TOMORROW. TELLER MAY ALSO HAVE TO BE EXTENDED BUT GIVEN THE
UNCERTAINTIES IN HOW THE BAND OF SNOW NORTH OF THE UPPER LOW WILL
SET UP...WILL LEAVE THE ENDING TIME FOR SAT MORNING FOR NOW. HRRR
HAS MOST OF THE HEAVIER QPF NORTH OF TELLER WHILE THE RAP AND NAM
HAVE IT DIRECTLY OVER TELLER. SO...AMOUNTS ARE MOST UNCERTAIN OVER
THE PIKES PEAK AREA BUT THE GOING ADVISORY COVERS THAT HAZARD FOR
NOW. ROSE
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 256 PM MDT FRI APR 17 2015
CURRENTLY...THE UPPER LOW IS LOCATED OVER THE SW QUAD OF THE STATE
THIS AFTERNOON...AND WAS WRAPPING DRY AIR UP INTO PORTIONS OF SOUTH
CENTRAL AND SOUTHEAST CO EFFECTIVELY SHUTTING OFF PCPN AND EVEN
CLOUD COVER FOR PORTIONS OF THE CWA. BEFORE THE DRY AIR MOVED
IN...HEAVY SNOW WAS REPORTED OVER MANY OF THE AREA MTS AS WELL AS
THE UPPER ARKANSAS RIVER BASIN...ALONG WITH SIGNIFICANT RAINFALL
AMOUNTS ALL ALONG THE I25 CORRIDOR. CLOUD ENHANCEMENT WAS OCCURRING
AS OF 3 PM OVER THE S MTS...SLOWLY SPREADING NORTH. FARTHER
EAST...DRY AIR PUSHED INTO THE SE CORNER OF THE STATE AND HELPED TO
PUSH THE SEVERE THREAT N AND NE. A FEW THUNDERSTORMS HAVE STRUGGLED
ACROSS THE PLAINS THIS AFTERNOON AS LOWER DEWPOINTS HAVE ROBBED
LOW LEVEL ENERGY.
TONIGHT AND TOMORROW...THE MAIN QUESTION IS WHERE WILL THE UPPER LOW
GO. MODELS STILL INDICATE THAT IT WILL GRADUALLY MOVE NORTH INTO
CENTRAL COLORADO THIS EVENING...THEN EDGE DUE EAST THROUGH TOMORROW
AFTERNOON. AFTER A BRIEF LULL...WHICH WILL MOST LIKELY HAVE
CUSTOMERS SCRATCHING THEIR HEADS...ALL MODELS INCLUDING THE HI-RES
OFFERINGS SHOW SHOWERS REDEVELOPING OVER THE PALMER DVD AND
RAMPART RANGE...AS WELL AS THE CENTRAL MTS...N SANGRES AND
WETS...THIS EVENING AND OVERNIGHT. ADDITIONAL SNOW AMOUNTS DO NOT
LOOK AS SIGNIFICANT NOW AS THEY DID 12 HRS AGO...AND HANDLING OF
THE HIGHLIGHTS WAS EXCEPTIONALLY TRICKY. DECIDED TO PUSH ALL
ENDING TIMES OF HIGHLIGHTS TO 12Z TOMORROW MORNING...AND CONVERTED
SOME OF THE ONGOING WARNINGS TO ADVISORIES. FURTHER ADJUSTMENTS TO
THE POP AND HIGHLIGHT GRIDS WILL OCCUR UNDOUBTEDLY. AS FOR
TEMPS...FRESH SNOW COVER FOR MUCH OF THE HIGHER TERRAIN AND HIGH
VALLEYS WILL MAKE FOR A COLD NIGHT...AS WELL AS MODIFYING THE MAX
TEMP TOMORROW DOWNWARD A FEW DEGREES. LOOK FOR MAX TEMPS TOMORROW
IN THE 40S TO NEAR 50 F FOR THE HIGH VALLEYS...50S TO LOWER 60S
FOR THE E PLAINS...WITH AREAS THAT RECEIVED EXTENSIVE SNOW COVER
ON THE LOWER END. MOORE
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 PM MDT FRI APR 17 2015
OLD UPPER LOW OPENS UP AND PULLS AWAY TO THE EAST SAT NIGHT/SUNDAY.
ANOTHER LOBE OF ENERGY ROTATING AROUND THE BACK SIDE OF THE UPPER
LOW WILL SPREAD ANOTHER BAND OF SNOW SHOWERS INTO THE MTS/PALMER
DIVIDE SATURDAY EVENING...AND INTO THE SOUTHEAST PLAINS SAT
NIGHT/EARLY SUNDAY MORNING. OVERALL ACCUMULATIONS DO NOT LOOK LIKE
THEY WILL BE THAT HEAVY...BUT A COUPLE INCHES ACROSS THE CENTRAL
MTS AND PIKES PEAK REGION WILL BE POSSIBLE...WITH 1-2 ACROSS THE
PALMER DIVIDE. IT WILL BE SOMEWHAT UNSTABLE...SO THERE IS ALWAYS A
CHANCE FOR SOME LOCALLY HEAVY BURSTS OF SNOW...BUT THINK THESE
SHOULD BE FAIRLY LOCALIZED. MEANWHILE PRECIPITATION WILL FALL AS
RAIN ACROSS THE SE PLAINS EARLY BEFORE DIMINISHING BY LATE SUN
MORNING. WINDS REALLY INCREASE ACROSS THE AREA FOR SUNDAY BEHIND
THE SYSTEM WITH NORTH WINDS GUSTING TO 40 TO 50 MPH ACROSS THE
PLAINS. FORTUNATELY MANY PLACES HAVE HAD SOME RAIN...WHICH SHOULD
MINIMIZE BLOWING DUST CONCERNS SOME...AND COOLER AIR BEHIND THE
SYSTEM SHOULD KEEP RELATIVE HUMIDITY VALUES FROM REACHING CRITICAL
LEVELS WHICH SHOULD MITIGATE ANY FIRE WEATHER CONCERNS.
NORTHWEST FLOW KEEPS UNSETTLED WEATHER OVER THE REGION FOR MONDAY
AND TUESDAY WITH PRIMARILY AFTERNOON AND EVENING SNOW SHOWERS OVER
THE MOUNTAINS. ANOTHER REINFORCING NORTHERLY SURGE MOVES THROUGH THE
PLAINS ON MONDAY WHICH WILL ENHANCE EASTERLY UPSLOPE FLOW INTO THE
SOUTHEAST MOUNTAINS. THIS WILL RESULT IN SCATTERED SNOW SHOWERS AS
ANOTHER SHORTWAVE MOVES THROUGH NW FLOW ALOFT. GFS SPREADS THESE
SHOWERS EASTWARD ONTO THE PLAINS DURING THE EVENING HOURS THOUGH
PRECIPITATION WILL FALL MAINLY AS RAIN. WESTERN U.S UPPER RIDGE
TRANSLATES EASTWARD FOR TUESDAY WITH SHOWERS STAYING MORE CONFINED
TO THE MOUNTAINS. AGAIN...MAINLY LIGHT ACCUMULATIONS EXPECTED.
ANOTHER TROF MOVES INTO THE WESTERN U.S FOR THE LATTER PART OF THE
WEEK. UPPER RIDGE AXIS SHIFTS OVER CO FOR WEDNESDAY...THEN
GRADUALLY INTO THE PLAINS THURS AND FRI AS THE UPPER TROF MOVES
TOWARDS THE GREAT BASIN. LOTS OF VARIABILITY BETWEEN THE LONG RANGE
MODELS ON TIMING...BUT BOTTOM LINE IS FOR INCREASING SOUTHWEST FLOW
FOR THURSDAY AND FRIDAY...SPREADING A CHANCE OF SNOW SHOWERS INTO
THE CONTDVD REGION BY LATE WEEK. TEMPERATURES REBOUND ACROSS THE
PLAINS...THOUGH SOUTHEAST FLOW ADVECTS HIGHER DEW POINTS INTO THE
PLAINS BRINGING A CHANCE FOR THUNDERSTORMS. AS SOUTHWEST FLOW ALOFT
INCREASES...THIS SHOULD HELP DEVELOP A DRY LINE AND PUSH IT EASTWARD
ACROSS THE PLAIN...WITH THUNDERSTORMS POSSIBLE ALONG AND TO ITS EAST
THURS AFTERNOON. WILL HAVE TO WATCH THIS DEVELOPMENT AS DEEP
LAYER SHEAR LOOKS FAVORABLE FOR STRONG TO SEVERE THUNDERSTORMS...IF
SUFFICIENT MOISTURE CAN RETURN...BUT GIVEN THE UNCERTAINTIES IN
THE EVOLUTION OF THE SYSTEM...THESE DETAILS ARE LIKELY TO EVOLVE
OVER THE NEXT SEVERAL DAYS. -KT
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1106 PM MDT FRI APR 17 2015
LARGE UPPER LOW PRESSURE AREA SPINNING OVER THE MOUNTAINS THIS
EVENING AND DRIFTING SLOWLY EASTWARD. UPPER LOW HAS WEAKENED
CONSIDERABLY FROM THIS TIME YESTERDAY. CONDITIONS ARE MOSTLY VFR
ACROSS THE FLIGHT AREA EXCEPT FOR ISOLATED TO SCATTERED SNOW SHOWERS
PRODUCING POCKETS OF MVFR/IFR/LIFR FLIGHT CONDITIONS...MAINLY OVER
THE MOUNTAINS. UPPER LOW WILL DRIFT SLOWLY EASTWARD INTO SOUTHWEST
KANSAS FROM 06Z SATURDAY TO 06Z SUNDAY. AS IT DOES SO...ISOLATED
TO SCATTERED SHOWERS WILL CONTINUE OVER THE FLIGHT AREA...RESULTING
IN AREAS OF MVFR/IFR FLIGHT CONDITIONS AND POCKETS OF LIFR CONDITIONS
UNDER THE HEAVIER PRECIPITATION. KCOS...KPUB AND KALS TAF SITES
SHOULD REMAIN GENERALLY VFR THROUGH THE NEXT 24 HOURS. HOWEVER...IT
IS POSSIBLE THAT RAIN OR SNOW SHOWERS COULD BRIEFLY IMPACT ANY OF
THE TERMINALS...ESPECIALLY KCOS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM MDT SATURDAY FOR COZ059-063-
066-081.
WINTER WEATHER ADVISORY UNTIL 6 PM MDT SATURDAY FOR COZ058-060-
061.
WINTER STORM WARNING UNTIL 6 PM MDT SATURDAY FOR COZ082.
&&
$$
UPDATE...ROSE
SHORT TERM...MOORE
LONG TERM...KT
AVIATION...LW
AREA FORECAST DISCUSSION
NWS ALBANY NY
157 PM EDT SAT APR 18 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION TODAY...HOWEVER ITS
ASSOCIATED MOISTURE IS RATHER LIMITED SO MAINLY ONLY AN INCREASE
IN CLOUDS IS EXPECTED. IN ITS WAKE...WINDS WILL BECOME BREEZY FOR
SEVERAL HOURS. HIGH PRESSURE WILL BUILD IN TONIGHT AND SUNDAY
RESULTING IN FAIR AND DRY WEATHER. A SERIES OF WEATHER SYSTEMS
WILL IMPACT THE REGION NEXT WEEK RESULTING IN COOL...DAMP...AND
UNSETTLED CONDITIONS. A WIDESPREAD RAINFALL IS EXPECTED MONDAY
AND MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
MORNING FOG BURNED OFF QUICKLY. A SHORT WAVE TROUGH AND ITS
ASSOCIATED LOW PRESSURE SYSTEM WILL PASS JUST TO OUR NORTHEAST
AND MOVE ACROSS NEW ENGLAND TODAY. MOISTURE REMAINS RATHER LIMITED
WITH THIS SYSTEM. LATEST HRRR ONLY INDICATES SCATTERED CONVECTION
SHOULD REMAINING MAINLY TO OUR NORTH AND EAST. THE BEST POTENTIAL
FOR SOME BRIEF SHOWER WILL BE NORTH OF ALBANY AND INTO THE
SOUTHERN GREENS OF VERMONT.
THE MAIN ISSUE FOR THE DAY IS BREEZY WESTERLY WINDS DEVELOPING
FOR THE AFTERNOON. MOMENTUM TRANSFER OF THE HIGHER MAGNITUDE
WINDS SUGGEST WE TAP INTO H700 LAYER WHERE 30+KTS RESIDES...SO
EXPECTING GUSTS OF 25 TO 35 MPH.
AS FOR TEMPERATURES...GIVEN THE DEEP MIXING EXPECTED AND CURRENT
TEMPERATURES RUNNING A COUPLE DEGREES WARMER...GUIDANCE AND DRY
ADIABATIC DECENT OF THOSE PARCELS ALONG WITH FAVORED LOCATIONS FOR
DOWNSLOPING WOULD YIELD TEMPERATURES AT 70F OR LOWER 70S FOR
VALLEY LOCATIONS AND 50S FOR THE HIGHER TERRAIN.
TONIGHT...SUBSIDENCE ALONG WITH DRIER AIR ALOFT AND SURFACE HIGH
BUILDING INTO THE REGION WILL RESULT IN DIMINISHING WINDS AND ANY
RESIDUAL CLOUD COVER. SO A CLEAR NIGHT EXPECTED WITH LOWS RANGING
FROM THE UPPER 20S ACROSS THE DACKS TO AROUND 40F ALONG THE HUDSON
RIVER FROM ALBANY AND POINT SOUTHWARD.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
GEN MODEL SUITE AGREEMENT HERE WITH SOME SPREAD TWRD THE END OF
THE PERIOD...MAINLY ON QPF AMNTS.
SUNDAY BEGINS WITH 500HPA RIDGE AXIS FM DELMARVA TO LK HURON...AND
SFC HIGH RIDGING S FM QB. RESULT WILL BE WIDESPREAD SUBSIDENCE...LOW
RH...LIGHT WINDS AND BRILLIANT SUNSHINE. SUN EVNG THE 500HPA RIDGE
WILL SLIDE OFFSHORE ALONG WITH THE SFC HIGH. OVERNIGHT EVOLVING
UPR GRT PLAINS 500HPA CUT OFF SHIFTS E...SHARPENING THE TROF/RIDGE
AMPLITUDE AND SHORTING THE WAVELENGTH AND UVM. SFC CYCLOGEN
ENSUES IN THE W OHIO VLY AND LIFTS NE INTO THE S GRTLKS MON. WMFNT
TRAILS SE FM MI-VA CAPES...AND LIFTS TWRD RGN SUN NT AS SFC LOW
ORGANIZES ON THE COAST. RESULT WILL BE RAPIDLY INCRG LLVL SFC WIND
GRAD...INCRG LLVL JETS...AND MOISTURE INFLUX INTO RGN. SHRA WILL
DEVELOP OVERNIGHT SUN AND EVOLVE INTO A WIDESPREAD RAIN INTO MON.
THE 500HPA CUT OFF OVER THE GRT PLAINS MOVES LITTLE BY TUES ONLY
REACHING LK SUPERIOR. WITH THE SFC LOW OVER ONTARIO...THE FRONTAL
STRUCTURE HAS EVOLVED INTO AN OCCLUSION FM OTTAWA VLY TO CSTL LOW
OVER S NEW ENG TUE MRNG. ONCE THE OCCLUSION CLEARS THE AREA...DRY
SLOT WRAPS ACROSS REGION WITH GENERALLY IMPVG CONDS. ALTHOUGH
THERE IS SOME SPREAD IN THE MODELS ON THE TIMING..ALL HAVE DONE SO
BY 18UTC TUES. AS 500HPA SHORT WVS ARE IN ROTATION AROUND BASE OF
CUTOFF TO OUR NW...SCT -SHRA MAY STILL OCCURRING IN STEEPENING
LAPSE RATE OVER FCA.
TEMPS WILL BE NR TO SLIGHTLY BLO NORMALS DURING THIS PERIOD WITH
HIGHS IN THE UPPER 50S TO MID 60S SUNDAY...AND MAINLY IN THE 50S
AFTERWARDS. LOWS WILL BE IN THE 30S WITH 40S TUESDAY MORNING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THIS PERIOD WILL BE DOMINATED BY A LARGE VERTICAL LOW PRESSURE
SYSTEM CENTERED OVER ONTARIO...BUT IMPACTING MUCH OF EASTERN HALF
OF CANADA AND NE USA.
WHILE THE MODELS DIFFER IN TIMING AND PLACEMENT OF THE FEATURES...THE
MAIN STORY WILL BE 500HPA SHORT WVS ROTATING AROUND THE LARGE
CUTOFF...EACH DRAGGING A SFC FRONT/BOUNDARY THROUGH THE FCA.
THESE FEATURES WILL PRODUCE VRBL CLOUDS...AND TRIGGER SCT TO AT
TIMES BKN -SHRA... MAYBE SOME -SHSN AT HIR TRRN...HWVR THE
ACTIVITY WILL BE DIURNALLY MODULATED AS STRONG APRIL SUN...AND
STEEP LAPSE RATES WILL ENHANCE THE CONVECTIVE NATURE OF THE SYSTEM
AN MAY EVEN RESULT IN SOME SMALL HAIL.
AS ITS OFTEN WITH THESE EVENTS...WHEN FCA IS ON SE QUADRANT OF A
MAJOR CUT OFF SYSTEM...THEY TEND TO OVER DO THE DISMAL CONDITIONS
CLOUDS AND SHOWERS.
FCST PERIOD WILL FEATURE BLO NORMAL TEMPS WITH HIGHS MAINLY
50S...LOWS IN THE 30S...VRBLE CLOUDS...SCT -SHRA/-SHSN. THESE WILL
BE DRIVEN...DIURNALLY...WITH PASSING 500HPA SHORT WVS AND BY CDFNTS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
A SHORT WAVE TROUGH AND ITS ASSOCIATED LOW PRESSURE SYSTEM ARE
PASSING JUST TO OUR NORTHEAST AND WILL MOVE ACROSS NEW ENGLAND
THIS AFTERNOON. SHOWERS ASSOCIATED WITH THE SYSTEM ARE GRAZING
THE EXTREME NORTHEAST PORTION OF THE FORECAST AREA AND ARE TO THE
NORTH AND EAST KGFL. SO JUST AN INCREASE IN CLOUDS IS EXPECTED
FOR THE TAFS.
WITH THE PASSAGE OF THE SYSTEM`S COLD FRONT WINDS WILL SHIFT TO
THE WEST-NORTHWEST AND INCREASE AND BECOME GUSTY WITH GUSTS
AROUND 25 KNOTS.
THE WINDS WILL WEAKEN THIS EVENING AS RIDGING BUILDS IN FROM THE
NORTHWEST AND ANY LINGER CLOUDS WILL DISSIPATE WITH LOSS OF HEATING.
WINDS WILL BECOME LIGHT OVERNIGHT AND SHIFT TO THE NORTHEAST TO
SOUTHEAST SUNDAY MORNING AS THE RIDGE BUILDS IN FARTHER.
OUTLOOK...
SUNDAY NIGHT: HIGH OPERATIONAL IMPACT. BREEZY. LIKELY RA.
MONDAY: HIGH OPERATIONAL IMPACT. BREEZY. DEFINITE RA.
MONDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE RA.
TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
RED FLAG WARNING FOR ALL OF EASTERN NEW YORK...BERKSHIRES AND
NORTHWEST CONNECTICUT LATER TODAY...
GUSTY WINDS AND LOW RELATIVE HUMIDITIES FOR SOUTHERN VERMONT...
EXTENSIVE COORDINATION OVERNIGHT ALONG WITH FORECAST METEOROLOGICAL
CONDITIONS HAVE WARRANTED THE UPGRADE TO RED FLAG WARNINGS FOR
EASTERN NEW YORK...BERKSHIRES AND NORTHWEST CONNECTICUT. WE WILL
HIGHLIGHT THE LOW RELATIVE HUMIDITIES...SNOW COVERAGE INTO THE
HIGHER TERRAIN...AND GUSTY WINDS WITH A SPECIAL WEATHER STATEMENT
/SPS/ FOR SOUTHERN VERMONT.
COMPACT WAVE TO THE NORTH OF THE GREAT LAKES WILL TRACK EAST-
SOUTHEAST TODAY. MOISTURE ASSOCIATED WITH THIS SYSTEM REMAINS
LIMITED...HOWEVER...ISOLATED SHOWERS ARE POSSIBLE MAINLY TO THE
NORTH OF ALBANY AND INTO SOUTHERN VT AND PERHAPS TOUCHING NORTHERN
BERKSHIRES. THEREAFTER...DEEP MIXING WITH INCREASING WINDS AND
DROPPING RELATIVE HUMIDITY VALUES YIELDS A COMBINATION OF FIRE
WEATHER HAZARDS TODAY. THE MAIN IMPACT POTENTIAL WILL BE DURING THE
AFTERNOON HOURS.
FOR SOUTHERN VERMONT...INCREASE IN CLOUD COVER ALONG WITH MARGINAL
LEVELS FOR FIRE WEATHER...SNOW COVER ACROSS THE HIGHER TERRAIN AND
COORDINATION WITH OFFICIALS HAVE RESULTED IN A SPECIAL WEATHER
STATEMENT /SPS/.
TONIGHT...WINDS WILL SUBSIDE ALONG WITH A SLOW RECOVERY OF THE
RELATIVE HUMIDITY VALUES AS A SURFACE HIGH BUILDS INTO THE REGION.
THIS HIGH REMAINS IN CONTROL THROUGH SUNDAY WITH LIGHT WINDS YET DRY
CONDITIONS WITH MINIMUM RELATIVE HUMIDITY VALUES RANGING BETWEEN 20-
30 PERCENT.
&&
.HYDROLOGY...
NO HYDROLOGY ISSUES EXPECTED THROUGH THE MONDAY MORNING AS CONDITIONS
WILL BE MAINLY DRY EXCEPT ISOLD -SHRA N TIER MIDDAY TODAY WITH A
CFP. A WIDESPREAD SOAKING RAINFALL IS LIKELY LATE SUNDAY NIGHT
INTO TUESDAY W/QPF ON THE ORDER OF HALF AN INCH TO AN INCH.
THE NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER (NOHRSC)
INDICATES THAT THERE IS STILL A FEW INCHES OF WATER EQUIVALENT IN
THE SNOW PACK ACROSS THE SRN ADIRONDACKS AND NORTHEASTERN
BERKSHIRE COUNTY. PORTIONS OF THE SOUTHERN GREEN MOUNTAINS STILL
HAVE 4 TO 9 INCHES OF SNOW WATER EQUIVALENT.
THE GENERAL CONSENSUS IS FOR AROUND AN ONE INCH OF RAINFALL AT
THIS TIME WITH THE HIGHER TOTALS SOUTH OF THE CAPITAL DISTRICT.
THIS RAINFALL COMBINED WITH RISES FROM ONGOING SNOWMELT NORTH...MAY
RESULT IN WITHIN BANK RISES MONDAY AND TUESDAY.
FOR DETAILS ON SPECIFIC AREA RIVER AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB-
SITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR CTZ001-013.
NY...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR NYZ032-033-
038>043-047>054-058>061-063>066-082>084.
MA...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR MAZ001-025.
VT...NONE.
&&
$$
SYNOPSIS...IAA/SNYDER
NEAR TERM...IAA/BGM/NAS/WASULA
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...IAA
FIRE WEATHER...IRL/WASULA
HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
1110 AM EDT SAT APR 18 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION TODAY...HOWEVER ITS
ASSOCIATED MOISTURE IS RATHER LIMITED SO MAINLY ONLY AN INCREASE
IN CLOUDS IS EXPECTED. IN ITS WAKE...WINDS WILL BECOME BREEZY FOR
SEVERAL HOURS. HIGH PRESSURE WILL BUILD IN TONIGHT AND SUNDAY
RESULTING IN FAIR AND DRY WEATHER. A SERIES OF WEATHER SYSTEMS
WILL IMPACT THE REGION NEXT WEEK RESULTING IN COOL...DAMP...AND
UNSETTLED CONDITIONS. A WIDESPREAD RAINFALL IS EXPECTED MONDAY
AND MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
MORNING FOG BURNED OFF QUICKLY. A SHORT WAVE TROUGH AND ITS
ASSOCIATED LOW PRESSURE SYSTEM WILL PASS JUST TO OUR NORTHEAST
AND MOVE ACROSS NEW ENGLAND TODAY. MOISTURE REMAINS RATHER LIMITED
WITH THIS SYSTEM. LATEST HRRR ONLY INDICATES SCATTERED CONVECTION
SHOULD REMAINING MAINLY TO OUR NORTH AND EAST. THE BEST POTENTIAL
FOR SOME BRIEF SHOWER WILL BE NORTH OF ALBANY AND INTO THE
SOUTHERN GREENS OF VERMONT.
THE MAIN ISSUE FOR THE DAY IS BREEZY WESTERLY WINDS DEVELOPING
FOR THE AFTERNOON. MOMENTUM TRANSFER OF THE HIGHER MAGNITUDE
WINDS SUGGEST WE TAP INTO H700 LAYER WHERE 30+KTS RESIDES...SO
EXPECTING GUSTS OF 25 TO 35 MPH.
AS FOR TEMPERATURES...GIVEN THE DEEP MIXING EXPECTED AND CURRENT
TEMPERATURES RUNNING A COUPLE DEGREES WARMER...GUIDANCE AND DRY
ADIABATIC DECENT OF THOSE PARCELS ALONG WITH FAVORED LOCATIONS FOR
DOWNSLOPING WOULD YIELD TEMPERATURES AT 70F OR LOWER 70S FOR
VALLEY LOCATIONS AND 50S FOR THE HIGHER TERRAIN.
TONIGHT...SUBSIDENCE ALONG WITH DRIER AIR ALOFT AND SURFACE HIGH
BUILDING INTO THE REGION WILL RESULT IN DIMINISHING WINDS AND ANY
RESIDUAL CLOUD COVER. SO A CLEAR NIGHT EXPECTED WITH LOWS RANGING
FROM THE UPPER 20S ACROSS THE DACKS TO AROUND 40F ALONG THE HUDSON
RIVER FROM ALBANY AND POINT SOUTHWARD.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
GEN MODEL SUITE AGREEMENT HERE WITH SOME SPREAD TWRD THE END OF
THE PERIOD...MAINLY ON QPF AMNTS.
SUNDAY BEGINS WITH 500HPA RIDGE AXIS FM DELMARVA TO LK HURON...AND
SFC HIGH RIDGING S FM QB. RESULT WILL BE WIDESPREAD SUBSIDENCE...LOW
RH...LIGHT WINDS AND BRILLIANT SUNSHINE. SUN EVNG THE 500HPA RIDGE
WILL SLIDE OFFSHORE ALONG WITH THE SFC HIGH. OVERNIGHT EVOLVING
UPR GRT PLAINS 500HPA CUT OFF SHIFTS E...SHARPENING THE TROF/RIDGE
AMPLITUDE AND SHORTING THE WAVELENGTH AND UVM. SFC CYCLOGEN
ENSUES IN THE W OHIO VLY AND LIFTS NE INTO THE S GRTLKS MON. WMFNT
TRAILS SE FM MI-VA CAPES...AND LIFTS TWRD RGN SUN NT AS SFC LOW
ORGANIZES ON THE COAST. RESULT WILL BE RAPIDLY INCRG LLVL SFC WIND
GRAD...INCRG LLVL JETS...AND MOISTURE INFLUX INTO RGN. SHRA WILL
DEVELOP OVERNIGHT SUN AND EVOLVE INTO A WIDESPREAD RAIN INTO MON.
THE 500HPA CUT OFF OVER THE GRT PLAINS MOVES LITTLE BY TUES ONLY
REACHING LK SUPERIOR. WITH THE SFC LOW OVER ONTARIO...THE FRONTAL
STRUCTURE HAS EVOLVED INTO AN OCCLUSION FM OTTAWA VLY TO CSTL LOW
OVER S NEW ENG TUE MRNG. ONCE THE OCCLUSION CLEARS THE AREA...DRY
SLOT WRAPS ACROSS REGION WITH GENERALLY IMPVG CONDS. ALTHOUGH
THERE IS SOME SPREAD IN THE MODELS ON THE TIMING..ALL HAVE DONE SO
BY 18UTC TUES. AS 500HPA SHORT WVS ARE IN ROTATION AROUND BASE OF
CUTOFF TO OUR NW...SCT -SHRA MAY STILL OCCURRING IN STEEPENING
LAPSE RATE OVER FCA.
TEMPS WILL BE NR TO SLIGHTLY BLO NORMALS DURING THIS PERIOD WITH
HIGHS IN THE UPPER 50S TO MID 60S SUNDAY...AND MAINLY IN THE 50S
AFTERWARDS. LOWS WILL BE IN THE 30S WITH 40S TUESDAY MORNING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THIS PERIOD WILL BE DOMINATED BY A LARGE VERTICAL LOW PRESSURE
SYSTEM CENTERED OVER ONTARIO...BUT IMPACTING MUCH OF EASTERN HALF
OF CANADA AND NE USA.
WHILE THE MODELS DIFFER IN TIMING AND PLACEMENT OF THE FEATURES...THE
MAIN STORY WILL BE 500HPA SHORT WVS ROTATING AROUND THE LARGE
CUTOFF...EACH DRAGGING A SFC FRONT/BOUNDARY THROUGH THE FCA.
THESE FEATURES WILL PRODUCE VRBL CLOUDS...AND TRIGGER SCT TO AT
TIMES BKN -SHRA... MAYBE SOME -SHSN AT HIR TRRN...HWVR THE
ACTIVITY WILL BE DIURNALLY MODULATED AS STRONG APRIL SUN...AND
STEEP LAPSE RATES WILL ENHANCE THE CONVECTIVE NATURE OF THE SYSTEM
AN MAY EVEN RESULT IN SOME SMALL HAIL.
AS ITS OFTEN WITH THESE EVENTS...WHEN FCA IS ON SE QUADRANT OF A
MAJOR CUT OFF SYSTEM...THEY TEND TO OVER DO THE DISMAL CONDITIONS
CLOUDS AND SHOWERS.
FCST PERIOD WILL FEATURE BLO NORMAL TEMPS WITH HIGHS MAINLY
50S...LOWS IN THE 30S...VRBLE CLOUDS...SCT -SHRA/-SHSN. THESE WILL
BE DRIVEN...DIURNALLY...WITH PASSING 500HPA SHORT WVS AND BY CDFNTS.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
APPEARS IFR CONDITIONS EVOLVED AT KGFL-KPSF OVERNIGHT WHERE DEWPOINT
DEPRESSIONS QUICKLY COLLAPSED. THIS FOG SHOULD BE RATHER SHALLOW IN
NATURE AND QUICKLY DISSIPATE WITH SUNRISE.
DURING THE DAY...FRONTAL BOUNDARY WILL QUICKLY MOVE ACROSS THE
REGION. WHILE MOISTURE REMAINS LIMITED WITH THIS SYSTEM...SOME SCT-
BKN VFR CIGS ARE EXPECTED MAINLY AFFECTING KGFL-KPSF.
OTHERWISE...WESTERLY WINDS WILL INCREASE WITH GUSTS OVER
20KTS...THEN WINDS SHIFTS TO THE NORTHWEST WITH EVEN SOME HIGHER
GUSTS AROUND 25KTS.
THE WINDS AND SKIES WILL ALL DISSIPATE THIS EVENING AS HIGH PRESSURE
SETTLES ACROSS THE ENTIRE REGION WITH VFR CONDITIONS EXPECTED.
OUTLOOK...
SUNDAY NIGHT: HIGH OPERATIONAL IMPACT. BREEZY. LIKELY RA.
MONDAY: HIGH OPERATIONAL IMPACT. BREEZY. DEFINITE RA.
MONDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE RA.
TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
RED FLAG WARNING FOR ALL OF EASTERN NEW YORK...BERKSHIRES AND
NORTHWEST CONNECTICUT LATER TODAY...
GUSTY WINDS AND LOW RELATIVE HUMIDITIES FOR SOUTHERN VERMONT...
EXTENSIVE COORDINATION OVERNIGHT ALONG WITH FORECAST METEOROLOGICAL
CONDITIONS HAVE WARRANTED THE UPGRADE TO RED FLAG WARNINGS FOR
EASTERN NEW YORK...BERKSHIRES AND NORTHWEST CONNECTICUT. WE WILL
HIGHLIGHT THE LOW RELATIVE HUMIDITIES...SNOW COVERAGE INTO THE
HIGHER TERRAIN...AND GUSTY WINDS WITH A SPECIAL WEATHER STATEMENT
/SPS/ FOR SOUTHERN VERMONT.
COMPACT WAVE TO THE NORTH OF THE GREAT LAKES WILL TRACK EAST-
SOUTHEAST TODAY. MOISTURE ASSOCIATED WITH THIS SYSTEM REMAINS
LIMITED...HOWEVER...ISOLATED SHOWERS ARE POSSIBLE MAINLY TO THE
NORTH OF ALBANY AND INTO SOUTHERN VT AND PERHAPS TOUCHING NORTHERN
BERKSHIRES. THEREAFTER...DEEP MIXING WITH INCREASING WINDS AND
DROPPING RELATIVE HUMIDITY VALUES YIELDS A COMBINATION OF FIRE
WEATHER HAZARDS TODAY. THE MAIN IMPACT POTENTIAL WILL BE DURING THE
AFTERNOON HOURS.
FOR SOUTHERN VERMONT...INCREASE IN CLOUD COVER ALONG WITH MARGINAL
LEVELS FOR FIRE WEATHER...SNOW COVER ACROSS THE HIGHER TERRAIN AND
COORDINATION WITH OFFICIALS HAVE RESULTED IN A SPECIAL WEATHER
STATEMENT /SPS/.
TONIGHT...WINDS WILL SUBSIDE ALONG WITH A SLOW RECOVERY OF THE
RELATIVE HUMIDITY VALUES AS A SURFACE HIGH BUILDS INTO THE REGION.
THIS HIGH REMAINS IN CONTROL THROUGH SUNDAY WITH LIGHT WINDS YET DRY
CONDITIONS WITH MINIMUM RELATIVE HUMIDITY VALUES RANGING BETWEEN 20-
30 PERCENT.
&&
.HYDROLOGY...
NO HYDROLOGY ISSUES EXPECTED THROUGH THE MONDAY MORNING AS CONDITIONS
WILL BE MAINLY DRY EXCEPT ISOLD -SHRA N TIER MIDDAY TODAY WITH A
CFP. A WIDESPREAD SOAKING RAINFALL IS LIKELY LATE SUNDAY NIGHT
INTO TUESDAY W/QPF ON THE ORDER OF HALF AN INCH TO AN INCH.
THE NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER (NOHRSC)
INDICATES THAT THERE IS STILL A FEW INCHES OF WATER EQUIVALENT IN
THE SNOW PACK ACROSS THE SRN ADIRONDACKS AND NORTHEASTERN
BERKSHIRE COUNTY. PORTIONS OF THE SOUTHERN GREEN MOUNTAINS STILL
HAVE 4 TO 9 INCHES OF SNOW WATER EQUIVALENT.
THE GENERAL CONSENSUS IS FOR AROUND AN ONE INCH OF RAINFALL AT
THIS TIME WITH THE HIGHER TOTALS SOUTH OF THE CAPITAL DISTRICT.
THIS RAINFALL COMBINED WITH RISES FROM ONGOING SNOWMELT NORTH...MAY
RESULT IN WITHIN BANK RISES MONDAY AND TUESDAY.
FOR DETAILS ON SPECIFIC AREA RIVER AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB-
SITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR CTZ001-013.
NY...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR NYZ032-033-
038>043-047>054-058>061-063>066-082>084.
MA...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR MAZ001-025.
VT...NONE.
&&
$$
SYNOPSIS...IAA/SNYDER
NEAR TERM...IAA/BGM/NAS/WASULA
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...BGM/NAS
FIRE WEATHER...IRL/WASULA
HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
1002 PM EDT SUN APR 19 2015
.UPDATE...CONVECTION FROM THIS AFTERNOON HAS PUSHED WELL OFFHORE
INTO THE ATLANTIC THIS EVENING. A SOUTHWEST FLOW FROM THE GULF
WILL CONTINUE TO PUSH CLOUDS INTO THE REGION. WITH AMPLE RESIDUAL
MOISTURE OVER THE REGION FROM THIS AFTERNOON`S RAINFALL...PATCHY
LOW CLOUDS AND FOG WILL BE POSSIBLE IN THE EARLY MORNING HOURS.
MODELS DIVERGE WITH THE AMOUNT OF DRYING IN THE LOW AND MID
LEVELS MONDAY. THE NAM AND HRRR MORE ROBUST WITH MOISTURE LEVELS
WITH SOME DRYING ACROSS THE NW ZONES (INTERIOR SE GA) BETWEEN 21Z
AND 00Z. LOOKING AT THE 700-300 MB STREAMLINES AND RH...THERE WILL
BE GOOD DIFFLUENCE ALOFT...GOOD INSTABILITY...AND SHEAR DURING THE
AFTERNOON. THE BEST MOISTURE WILL BE ACROSS OUR SOUTHERN TIER
ZONES WHERE HIGHEST POPS (50-70 PERCENT) WITH DRIER AIR TO THE
NORTHERN PART OF THE CWA (LIMITED COVERAGE - 30 PERCENT) IS
ANTICIPATED. DESPITE LESS AREAL COVERAGE THE THREAT FOR DAMAGING
WINDS, HAIL AND A COUPLE TORNADOES CANNOT BE RULED OUT.
&&
.AVIATION...AFTER AN UNSETTLED DAY WITH SCATTERED TO CATEGORICAL
RAINFALL...CONDITIONS HAVE IMPROVED TO MVFR AND VFR. IFR
CONDITIONS ARE EXPECTED AT ALL TERMINALS AFTER 06Z DUE TO LOW
CLOUDS AND FOG. GREATEST CHANCE OF RAIN IS ACROSS THE SOUTHERN
THIRD OF THE AREA (GAINESVILLE AND SAINT AUGUSTINE TERMINALS).
MENTIONED TSTMS IN TEMPO GROUPS FOR ALL TERMINALS MONDAY AFTERNOON
WITH HIGHEST CONFIDENCE FOR KGNV AND KSGJ TERMINALS.
&&
.MARINE...WINDS WILL GRADUALLY INCREASE AND VEER OUT AHEAD OF
APPROACHING COLD FRONT ALTHOUGH NO HEADLINES EXPECTED THRU MONDAY.
THE COLD FRONT CROSSES THE WATERS MONDAY NIGHT BRINGING A BRIEF
PERIOD OF CONDITIONS APPROACHING ADVISORY CRITERIA IN THE
OFFSHORE COMPONENT. SCATTERED TO NUMEROUS AFTERNOON AND EVENING
SHOWERS/TSMS THRU MONDAY... WITH STRONG WINDS POSSIBLE WITH THE
MORE INTENSE STORMS. HIGH PRESSURE QUICKLY BUILDS IN BEHIND THE
FRONT TUE WITH WIND/SEAS DECREASING FOR REMAINDER OF WEEK.
RIP CURRENTS: LOW RISK MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 67 85 60 77 / 10 40 30 10
SSI 69 82 65 75 / 20 30 30 10
JAX 69 85 64 79 / 20 40 30 10
SGJ 70 83 67 77 / 20 50 40 10
GNV 68 85 65 81 / 20 60 40 10
OCF 69 85 66 82 / 20 70 50 10
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
CORDERO/ENYEDI/GUILLET
AREA FORECAST DISCUSSION
NWS KEY WEST FL
915 PM EDT SUN APR 19 2015
.DISCUSSION...IN THE MID AND UPPER LEVELS...LATEST IR IMAGERY AS OF OF
800 PM...OVERLAID WITH AVAILABLE MODEL STREAMLINE ANALYSIS DEPICTS A
DEEP CYCLONIC MID AND UPPER PATTERN IN PLACE FROM THE SIERRA NEVADA
MOUNTAINS ALL THE WAY TO THE APPALACHIANS. A STRONG SUBTROPICAL JET
AVERAGING 50 KNOTS AT ABOUT 500 MB TO AROUND 100 KNOTS AT 250 MB
CONTINUES FROM BAJA CALIFORNIA EAST TOWARDS THE EASTERN GULF WHERE A
TROUGH IS PRESENT AND THE MID AND UPPER FLOW FANS OUT...EVIDENCE OF
DIFFLUENCE AT 250 MB.
AT THE SURFACE AND IN THE LOWER TO MID LEVELS...AS OF 800
PM...LATEST MARINE AND LAND SURFACE OBSERVATIONS ON TOP OF IR
ANALYSIS DETAIL A LOW PRESSURE OVER THE MIDDLE OHIO VALLEY WITH AN
ATTENDANT WARM FRONT DOWN TO OFF OF THE GEORGIA COAST...BUT CLOSER
TO KEYS LATITUDE...THERE IS AN APPROACHING LOW LEVEL TROUGH OVER THE
EASTERN GULF OF MEXICO. AS SUCH...THE 00Z SOUNDING AT KEY WEST THIS
EVENING ILLUSTRATED A VEERING SURFACE TO 700 MB FLOW...WITH GENTLE
SOUTHERLIES BECOMING SOUTHWEST AT 850 THEN FRESHENING UP TO 500 MB.
DESPITE SOME COLUMNAR MOISTURE IN THE LOWER TO MID TROPOSPHERE WITH
COLUMNAR PWAT AT 1.50 INCHES...THERE IS ABUNDANT DRY AIR ABOVE 700
MB.
.CURRENTLY...AS OF 800 PM...SKIES ARE PARTLY CLOUDY ACROSS THE
ISLANDS AND SURROUNDING WATERS...OWING TO SOME ALTOCU BUT MOSTLY ALL
TYPES OF SCATTERED CIRRUS IN THE UPPER LEVELS. SURFACE OBSERVATIONS
AT BOTH AIRPORT ASOS HAVE ALSO RECORDED A SLIGHT REDUCTION IN
SURFACE VISIBILITY ON ACCOUNT OF WHAT IS BEING REPORTED AS
HAZE...WHICH MIGHT BE SMOKE FROM CANE FIELDS BURNING ON CUBA WHICH
HAS ADVECTED NORTHWARD THRU THE AFTERNOON HOURS. TEMPERATURES OVER
THE ISLANDS REMAIN IN THE LOWER 80S WITH DEWPOINTS IN THE MIDDLE
70S...MORE LIKE JUNE. LATEST C-MAN STATIONS ON THE REEF..FLORIDA BAY
AND REPORTS IN THE STRAITS ARE RECORDING VARIABLE WINDS NEAR 5
KNOTS.
.FORECASTS...OVERNIGHT...MID AND UPPER TROUGHING AND SOME SLIGHT
HEIGHT FALLS ARE INDICATED ACROSS THE EASTERN GULF OF MEXICO AS WELL
AS SOUTH FLORIDA AND THE KEYS. NEVERTHELESS...THERE ARE A LACK OF
BOUNDARIES ACROSS ALL LOCATION WITHIN 150 NM OF THE KEYS ATTM. CUBA
FAILED THIS AFTERNOON TO PRODUCE MORE THAN A FEW TINY
SHOWERS...LIKELY DUE TO THE DEARTH OF DRIER AIR OVER IT AND THE
NORTHWESTERN CARIBBEAN. BUT AS THE TROUGH NOW OVER THE EASTERN GULF
SLIDES A BIT MORE TO THE EAST...THE HRRR FAVORS DEVELOPMENT OF
SHOWERS DURING THE SECOND HALF OF THE OVERNIGHT...AFTER MIDNIGHT.
BOTH GFS AND ECMWF FORECAST SOUNDINGS DO MAINTAIN PWAT AOA 1.50
INCHES OR HIGHER OVERNIGHT. SO WILL MAINTAIN THE ISOLATED
SHOWERS...20% WE ALREADY HAVE IN THE FORECAST. A FEW LIGHTNING
STRIKES ARE POSSIBLE OVER THE FLORIDA STRAITS AND THE WARMER GULF
WATERS TO THE WEST.
&&
.MARINE...VARIABLE WINDS IN PLACE THIS EVENING SHOULD BECOME SOUTH
TO SOUTHWEST AND INCREASE BACK TO NEAR 10 KNOTS JUST IN ADVANCE OF
AN APPROACHING LOW LEVEL TROUGH OVER THE EASTERN GULF OF MEXICO.
OUTSIDE OF ANY SHOWERS...BOATING CONDITIONS SHOULD BE IDEAL
OVERNIGHT.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL AT EYW AND MTH TONIGHT AND MONDAY.
BRIEF...MVFR CEILINGS...BASED AT AROUND 1500 FEET...ARE CONCEIVABLE
AT EYW AND MTH AFTER MIDNIGHT TONIGHT INTO EARLY MONDAY MORNING.
THIS POSSIBILITY WILL NOT BE PLACED IN THE TERMINAL FORECASTS AT
THIS TIME DUE TO THE BRIEF NATURE OF OCCURRENCE. SUSTAINED SOUTHWEST
TO WEST WINDS NEAR 10 KNOTS EXPECTED FROM JUST OFF THE SURFACE TO
ABOUT 3000 FEET.
&&
.CLIMATE...
ON THIS DATE IN FLORIDA KEYS WEATHER HISTORY...IN 1934...THE HIGH
TEMPERATURE IN KEY WEST WAS 89 DEGREES. THIS SET THE DAILY RECORD
FOR MAXIMUM TEMPERATURE MEASURED IN KEY WEST ON APRIL 19TH...A
RECORD WHICH STILL STANDS 81 YEARS LATER. TEMPERATURE RECORDS AT KEY
WEST DATE BACK TO 1872.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE...............FUTTERMAN
AVIATION/CLIMATE...........BS
DATA COLLECTION/UPPER AIR..VICKERY
VISIT US ON THE WEB AT WEATHER.GOV/KEY
FOLLOW US ON FACEBOOK AND TWITTER AT...
WWW.FACEBOOK.COM/NWSKEYWEST
WWW.TWITTER.COM/NWSKEYWEST
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
251 PM EDT SAT APR 18 2015
.NEAR TERM...THROUGH TONIGHT...
BUILDING UPPER RIDGE OVER FORECAST AREA THROUGH TONIGHT.
SCATTERED SHOWERS AND ISOLATED T-STORMS POSSIBLE ALONG EXISTING
BOUNDARIES...MAINLY ALONG WARM FRONT MOVING NORTHWARD OVER SRN GA
AND FL SEA BREEZES. HRRR SUGGESTS THIS WITH PEAK COVERAGE TOWARD
00Z WITH DECREASE IN COVERAGE THEREAFTER. VISIBLE SATELLITE
IMAGERY SHOWS DECENT LOW-LEVEL SW FLOW LIKELY TO PIN EAST COAST
SEA BREEZE TO COAST...THUS HRRR PRIMARILY FOCUSING ANY DEVELOPMENT
ON EASTWARD MOVING WEST-COAST SEA BREEZE. WITH LITTLE DYNAMIC
SUPPORT...WILL KEEP POP VALUES BELOW 50 THROUGH TONIGHT.
SHORT TERM...SUNDAY THROUGH MONDAY NIGHT...
UPPER RIDGING MOVES OFFSHORE WHILE STRONG UPPER TROUGH OVER THE
PLAINS SHIFTS SLOWLY EASTWARD. SURFACE LOW PRESSURE TRACKS FROM
MS NORTHEAST TO IN DURING DAY SUNDAY...WITH OUR FORECAST IN WARM
SECTOR. GREATER LOW-LEVEL SW FLOW WILL PIN EAST COAST SEA BREEZE
TO COAST WHILE ADVANCING WEST COAST SEA BREEZE EASTWARD. THIS
COMBINED WITH ACTIVITY COMING FROM NORTHEAST GULF OF MEXICO
SUPPORTS HIGH POPS...PERHAPS HIGHEST WRN/NRN AREAS...GENERALLY
50-70 PCT.
ACTIVITY DIMINISHES SUNDAY NIGHT AS MID-LEVEL DRY SLOT SPREADS OVER
FORECAST AREA. FOR MONDAY...SYSTEM CONTINUES TRACKING NORTH AND
EAST...COLD FRONT APPROACHES THE AREA FROM THE NORTHWEST. MODEL
GUIDANCE INDICATES DRIER CONDITIONS ALOFT AND BETTER DYNAMICS
PASSING WELL NORTH OF OUR FORECAST AREA...THUS CONSIDERABLY LESS
PRECIP COVERAGE MON COMPARED TO SUN. WILL MAINTAIN 30 POP MON.
DESPITE LESSER COVERAGE...MODEL GUIDNCE SUGGESTS A FEW STRONG OR
SEVERE STORMS WILL BE POSSIBLE IN AN ENVIRONMENT WITH 2000 J/KG
CAPE AND 150-200 0-3KM SR-HELICITY. SPC HAS A MARGINAL/SLIGHT RISK
AREA OVER MOST OF OUR AREA MON.
WARM SUN AND MON WITH HIGHS 80 TO 85 NORTH OF I-10 CORRIDOR...MID
80S I-10 SOUTHWARD.
FRONT AND ASSOCIATED PRECIP SHIFT OFFSHORE MON NIGHT. FRONT
WASHES OUT OVER THE SOUTHERN PART OF FORECAST AREA WHILE WEAK
HIGH PRESSURE APPROACHES FROM THE GULF COAST STATES.
LONG TERM...TUESDAY THROUGH SATURDAY...
DRIER CONDITIONS WITH HIGH PRESSURE BUILDING NORTH OF THE AREA TUE.
SLIGHTLY COOLER HIGH TEMPS IN UPPER 70S TO LOWER 80S. WILL
CONTINUE TO CONFINE LOW POPS TO OUR SOUTHERN COUNTIES.
LITTLE CHANGE WED-FRI...WITH ISOLATED SEA BREEZE SHOWERS POSSIBLE
FL PENINSULA. BETTER CHANCE OF RAIN MAY COME NEXT SAT...BASED ON
GFS AND ECM...AND WILL SHOW POPS INCREASING THEN. HIGH TEMPS
GRADUALLY INCREASING TO MID 80S BY END OF WEEK.
&&
.AVIATION...GENERALLY VFR CONDITIONS EXPECTED NEXT 24 HRS...EXCEPT
LOCALLY LOWERER IN ISOLATED TSRA AND AREAS WHERE LATE NIGHT
PATCHY FOG OCCURS.
&&
.MARINE...SOUTH TO SOUTHWEST WINDS 10-15KTS AND 2-4FT SEAS EXPECTED
THRU MONDAY AHEAD OF NEXT COLD FRONT. AFTER FRONT PASSES...WINDS
WILL BECOME NORTH AND THEN NORTHEAST WITH HIGH PRESSURE BUILDING
JUST NORTH OF THE AREA. THE HIGH IS EXPECTED TO BE WEAK...RESULTING
IN FAIRLY WEAK WINDS AND LOW SEAS TUE/WED. BEFORE THE FRONT PASSES
MON NIGHT...WINDS COULD APPROACH SMALL CRAFT ADVISORY LEVELS
ACROSS THE OFFSHORE COMPONENT.
.RIP CURRENTS...MODERATE RISK THROUGH SUNDAY DUE TO A LINGERING SWELL.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 67 82 67 83 / 40 80 20 30
SSI 68 80 69 82 / 30 60 40 30
JAX 69 85 69 85 / 30 60 30 30
SGJ 69 82 69 83 / 30 50 30 30
GNV 68 85 68 85 / 20 60 20 30
OCF 68 85 69 85 / 20 50 20 40
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
WOLF/SANDRIK/GUILLET
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
954 PM CDT SUN APR 19 2015
.UPDATE...
809 PM CDT
STEADY RAIN WILL CONTINUE MUCH OF THE EVENING ACROSS NORTHERN
ILLINOIS. MID-LEVEL DRY SLOT WILL PIVOT ACROSS EAST-CENTRAL
ILLINOIS AND NORTHWEST INDIANA THIS EVENING WITH RAIN TAPERING TO
A LIGHT DRIZZLE FOR THESE AREAS...BEFORE SHOWERS SPREAD BACK IN
FROM THE WEST OVERNIGHT. ADDED PATCHY FOG TO THE GRIDS THIS
EVENING AND TONIGHT AS SATURATED TO NEAR SATURATED CONDITIONS ARE
IN PLACE THIS EVENING. SUSPECT VISIBILITY WILL BEGIN TO IMPROVE AS
WEST WINDS INCREASE AFTER MIDNIGHT TONIGHT.
BMD
&&
.SHORT TERM...
319 PM CDT
THROUGH MONDAY NIGHT...
AFTER ANOTHER WARM EARLY AFTERNOON ACROSS MUCH OF THE REGION RAIN IS
BEGINNING TO SPREAD NORTHWARD ACROSS SOUTHERN SECTIONS OF THE CHICAGO
METRO AREA AS OF THIS WRITING. THIS ACTIVITY WILL CONTINUE TO
OVERSPREAD THE REGION THROUGH THE AFTERNOON AND EVENING...WITH
TEMPERATURES LIKELY TO DROP BACK INTO THE UPPER 50S AND LOW 60S IN
THE RAIN.
THE MID-LEVEL DISTURBANCE...AND THE ASSOCIATED SURFACE SYSTEM WILL
QUICKLY SHIFT NORTHWARD OVER LOWER MICHIGAN OVERNIGHT...AND IT
APPEARS THAT THE RAIN WILL BECOME MORE SHOWERY AND INTERMITTENT OR
POSSIBLY JUST SOME DRIZZLE LATER THIS EVENING AND INTO THE EARLY
MORNING ACROSS MUCH OF THE AREA AS THIS INITIAL MID LEVEL
DISTURBANCE SHIFTS NORTH OF THE AREA AND SOME DRIER MID LEVEL AIR
SHIFTS OVER THE SOUTHEASTERN HALF OF MY AREA. SOME ADDITIONAL RAIN
SHOWERS ARE POSSIBLE AGAIN EARLY MONDAY WITHIN A REGION OF MID LEVEL
DEFORMATION AND RAP AROUND MOISTURE ASSOCIATED WITH THE DEEPENING
LOWER AND MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION AND
SOUTHERN CANADA.
CONDITIONS SHOULD DRY OUT MONDAY AFTERNOON...WITH ONLY A SMALL
CHANCE OF AN ADDITIONAL SHOWER DEVELOPING AS COLDER AIR ALOFT
STEEPENS THE LOWER LEVEL LAPSE RATES. THE MAIN STORY DURING THE
AFTERNOON WILL BE THE WINDS. WINDS ARE EXPECTED TO INCREASE OUT OF
THE WEST-NORTHWEST DURING THE DAY AS STOUT SURFACE PRESSURE
GRADIENT SETS UP OVER THE REGION AS THE SURFACE LOW DEEPENS TO
AROUND 985 MB ACROSS ONTARIO MONDAY AFTERNOON. MODEL SOUNDINGS
SUGGEST GOOD AFTERNOON MIXING TO AROUND 850 MB SHOULD ALLOW FOR
GUSTS OF AROUND 30 KT AT TIMES...ESPECIALLY DURING THE AFTERNOON.
THESE WIND GUSTS SHOULD ABATE MONDAY EVENING...BUT STRONG WINDS
LOOK TO DEVELOP AGAIN ON TUESDAY. SEE LONG TERM DISCUSSION FOR
MORE INFO ON TUESDAY`S WINDS.
KJB
&&
.LONG TERM...
319 PM CDT
TUESDAY THROUGH SUNDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH BELOW NORMAL TEMPS
THROUGH THE FORECAST.
LARGE UPPER LEVEL CENTER WILL BE CENTERED ACROSS THE REGION AT THE
START OF THE PERIOD...AND REMAIN SITUATED THROUGH MUCH OF THE WORK
WEEK AS IT SLOWLY MOVES EAST. SEVERAL VORT LOBES ARE ANTICIPATED TO
WRAP AROUND THIS UPPER LEVEL LOW ON TUESDAY AND WITH STEEPENING
LAPSE RATES...EXPECT SKY COVER TO INCREASE THROUGH THE DAY WHILE
SCATTERED SHOWERS BECOME POSSIBLE...ESPECIALLY ACROSS NORTHERN
ILLINOIS. AS THIS OCCURS...LIKELY DEEP MIXING WITH STRONG FLOW ALOFT
WILL ALLOW FOR ANOTHER WINDY DAY. GUIDANCE IS SUGGESTING THAT
ADVISORY CONDITIONS COULD BE REACHED IN THE AFTERNOON...AND WILL
NEED TO CONTINUE MONITORING THIS POTENTIAL. ANY REMAINING PRECIP AND
CLOUD COVER SHOULD EXIT THE AREA TUESDAY NIGHT WITH DRY CONDITIONS
EXPECTED. SOME GUIDANCE DEVELOPS A SWATH OF PRECIP OVER THE CWA LATE
IN THE NIGHT INTO EARLY WEDNESDAY. HOWEVER...A MORE LIKELY SCENARIO
AT THIS TIME WOULD BE FOR DRY CONDITIONS AND SO HAVE LEFT OUT ANY
POPS AT THIS TIME. ONGOING CAA WILL MAKE FOR CHILLY CONDITIONS
TUESDAY NIGHT...WITH LOW TEMPS IN THE 30S. IF PRECIP WERE TO OCCUR
DURING THIS PERIOD...THESE COLDER CONDITIONS COULD SUPPORT THE
POTENTIAL FOR AT LEAST A RAIN SNOW MIX ACROSS NORTHERN ILLINOIS.
EXPECT DRY CONDITIONS WITH BELOW NORMAL TEMPS THROUGH THE REST OF
THE FORECAST PERIOD...WITH FORECAST HIGHS IN THE 50S. COLD NIGHT
TIME LOWS IN THE 30S COULD BECOME AN ISSUE LATE IN THE WORK WEEK AS
HIGH PRESSURE IS ANTICIPATED TO MOVE OVERHEAD...WITH LIGHTER WINDS
AND THE COLD TEMPS POSSIBLY CREATING A SETUP FOR FROST.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* WINDS BACKING NORTHWEST LATE THIS EVENING.
* LIGHT RAIN SHOWERS LATE THIS EVENING BECOMING ISOLATED AFTER
05Z-06Z...THEN A PROBABLE PERIOD OF SHOWERS MONDAY MORNING.
* LIFR CIGS LASTING INTO OVERNIGHT WITH SLOW IMPROVEMENT DURING
THE DAYBREAK TIME.
* MVFR VISIBILITY LOWERING TO IFR LATE THIS EVENING THEN LIKELY
IMPROVING SLOWLY PRIOR TO DAYBREAK.
* GUSTY WEST WINDS DEVELOPING MONDAY MORNING WITH MAX GUSTS ARND
30 KT LATE MONDAY MORNING AND AFTERNOON.
//DISCUSSION...UPDATED 00Z...
A SHIELD OF RAIN AND AT TIMES RAIN SHOWERS WILL CONTINUE TO
ADVANCE NORTHWARD ACROSS THE TAF SITES THROUGH MID-EVENING.
VISIBILITY WILL SHOW SOME FLUCTUATIONS IN THIS RAIN...MAINLY
BETWEEN 3SM AND 5SM. AS THE RAIN BECOMES MORE SCATTERED SHOWERS
AFTER 02-03ZZ AND A LIGHTER WIND FLOW NEAR LOW PRESSURE
OCCURS...THE SATURATION IS EXPECTED TO BRING LIFR CONDITIONS. THIS
IS ALREADY BEING OBSERVED UPSTREAM IN CENTRAL AND EASTERN IL.
CONFIDENCE IS HIGHEST IN LIFR CIGS BUT VISIBILITY UNDER 1SM IS
ALSO POSSIBLE...ESPECIALLY AT TAF SITES NOT FAR FROM THE LAKE
INCLUDING ORD AND MDW. ALREADY WEBCAM IMAGERY FROM DOWNTOWN
CHICAGO SHOWS WHAT IS LIKELY PART LAKE ENHANCED SUB 1SM FOG AND
WITH CONTINUED NORTHEAST WINDS THIS EVE...THIS IS POSSIBLE THIS
ROLLS INTO ORD AND MDW IN THE WAKE OF THE SHOWERS.
LATER TONIGHT WESTERLY WINDS WILL BEGIN AND THIS MAY RESULT IN A
GRADUAL IMPROVEMENT BY DAYBREAK. SOON AFTER SUNRISE THE COLD FRONT
IS EXPECTED TO MOVE OVER CHICAGO WITH WESTERLY WINDS INCREASING.
THERE WILL BE LIKELY AN AREA OF SHOWERS TOO IN THE MORNING...BUT
OVERALL CIGS AND VISIBILITY SHOULD BE IMPROVING INTO THE MVFR
CATEGORY. THE PATTERN BEHIND THE COLD FRONT FAVORS GUSTY WINDS
WHICH ARE BEING OBSERVED ACROSS THE PLAINS STATES TODAY. SPORADIC
PEAK GUSTS OF 30 KT ARE EXPECTED BETWEEN 16Z-22Z.
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH IN WIND DIRECTION THROUGH THE TAF. MEDIUM-HIGH IN SPEED.
* HIGH IN RAIN TIMING.
* HIGH IN CIGS AND DURATION. MEDIUM IN CIGS ONLY DROPPING AS FAR
AS 400FT.
* MEDIUM IN VISIBILITY TRENDS AND VISIBILITY DROPPING NO MORE
THAN TO 1 1/2SM.
* MEDIUM IN CIGS/VISBYS AND SHRA DURING THE MORNING RUSH ON
MONDAY.
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...SLIGHT CHANCE OF SHRA AND MVFR. GUSTY WEST WINDS.
WEDNESDAY-THURSDAY...VFR. NORTHWEST WINDS.
FRIDAY-SATURDAY...VFR. WINDS BECOMING NORTHEAST.
MTF
&&
.MARINE...
324 PM CDT
AS A TROUGH OF LOW PRESSURE AND SECONDARY LOW PRESSURE CENTER
MOVE ACROSS THE GREAT LAKES REGION TONIGHT...WINDS WILL LIKELY BE
VARIABLE AT TIMES. THIS WILL ESPECIALLY BE THE CASE OVER THE
SOUTHERN HALF OF THE LAKE WHERE THE LOW PRESSURE SYSTEM IS
EXPECTED TO MOVE THROUGH. IN THE NEAR TERM...EAST NORTHEAST WINDS
WILL PREVAIL OVER THE LAKE WITH THE HIGHEST SPEEDS TO 30 KT
OCCURRING OVER THE NORTHERN HALF AND WHILE 15 TO 25 KT WINDS ARE
BEING OBSERVED OVER THE SOUTH...WITH SPEEDS EXPECTED TO SLIGHTLY
DIMINISH TONIGHT. AS THIS TROUGH/LOW EXIT TO THE EAST ON
MONDAY...STRONGER WESTERLY WINDS WILL DEVELOP. HIGHEST WINDS TO 30
KT WILL OCCUR ALONG THE NEARSHORE WATERS WHILE ONLY 15 TO 25 KT
ARE LIKELY OVER THE OPEN WATERS. A SIMILAR SETUP IS EXPECTED ON
TUESDAY BUT WITH SPEEDS SLIGHTLY HIGHER...AS TO 30 KT WILL LIKELY
PREVAIL FOR BOTH LOCATIONS AND WITH EVEN GALES POSSIBLE ALONG THE
NEARSHORE WATERS DURING THE DAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...11 AM MONDAY TO 9 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
NWS CHICAGO/ROMEOVILLE IL
810 PM CDT SUN APR 19 2015
.UPDATE...
809 PM CDT
STEADY RAIN WILL CONTINUE MUCH OF THE EVENING ACROSS NORTHERN
ILLINOIS. MID-LEVEL DRY SLOT WILL PIVOT ACROSS EAST-CENTRAL
ILLINOIS AND NORTHWEST INDIANA THIS EVENING WITH RAIN TAPERING TO
A LIGHT DRIZZLE FOR THESE AREAS...BEFORE SHOWERS SPREAD BACK IN
FROM THE WEST OVERNIGHT. ADDED PATCHY FOG TO THE GRIDS THIS
EVENING AND TONIGHT AS SATURATED TO NEAR SATURATED CONDITIONS ARE
IN PLACE THIS EVENING. SUSPECT VISIBILITY WILL BEGIN TO IMPROVE AS
WEST WINDS INCREASE AFTER MIDNIGHT TONIGHT.
BMD
&&
.SHORT TERM...
319 PM CDT
THROUGH MONDAY NIGHT...
AFTER ANOTHER WARM EARLY AFTERNOON ACROSS MUCH OF THE REGION RAIN IS
BEGINNING TO SPREAD NORTHWARD ACROSS SOUTHERN SECTIONS OF THE CHICAGO
METRO AREA AS OF THIS WRITING. THIS ACTIVITY WILL CONTINUE TO
OVERSPREAD THE REGION THROUGH THE AFTERNOON AND EVENING...WITH
TEMPERATURES LIKELY TO DROP BACK INTO THE UPPER 50S AND LOW 60S IN
THE RAIN.
THE MID-LEVEL DISTURBANCE...AND THE ASSOCIATED SURFACE SYSTEM WILL
QUICKLY SHIFT NORTHWARD OVER LOWER MICHIGAN OVERNIGHT...AND IT
APPEARS THAT THE RAIN WILL BECOME MORE SHOWERY AND INTERMITTENT OR
POSSIBLY JUST SOME DRIZZLE LATER THIS EVENING AND INTO THE EARLY
MORNING ACROSS MUCH OF THE AREA AS THIS INITIAL MID LEVEL
DISTURBANCE SHIFTS NORTH OF THE AREA AND SOME DRIER MID LEVEL AIR
SHIFTS OVER THE SOUTHEASTERN HALF OF MY AREA. SOME ADDITIONAL RAIN
SHOWERS ARE POSSIBLE AGAIN EARLY MONDAY WITHIN A REGION OF MID LEVEL
DEFORMATION AND RAP AROUND MOISTURE ASSOCIATED WITH THE DEEPENING
LOWER AND MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION AND
SOUTHERN CANADA.
CONDITIONS SHOULD DRY OUT MONDAY AFTERNOON...WITH ONLY A SMALL
CHANCE OF AN ADDITIONAL SHOWER DEVELOPING AS COLDER AIR ALOFT
STEEPENS THE LOWER LEVEL LAPSE RATES. THE MAIN STORY DURING THE
AFTERNOON WILL BE THE WINDS. WINDS ARE EXPECTED TO INCREASE OUT OF
THE WEST-NORTHWEST DURING THE DAY AS STOUT SURFACE PRESSURE
GRADIENT SETS UP OVER THE REGION AS THE SURFACE LOW DEEPENS TO
AROUND 985 MB ACROSS ONTARIO MONDAY AFTERNOON. MODEL SOUNDINGS
SUGGEST GOOD AFTERNOON MIXING TO AROUND 850 MB SHOULD ALLOW FOR
GUSTS OF AROUND 30 KT AT TIMES...ESPECIALLY DURING THE AFTERNOON.
THESE WIND GUSTS SHOULD ABATE MONDAY EVENING...BUT STRONG WINDS
LOOK TO DEVELOP AGAIN ON TUESDAY. SEE LONG TERM DISCUSSION FOR
MORE INFO ON TUESDAY`S WINDS.
KJB
&&
.LONG TERM...
319 PM CDT
TUESDAY THROUGH SUNDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH BELOW NORMAL TEMPS
THROUGH THE FORECAST.
LARGE UPPER LEVEL CENTER WILL BE CENTERED ACROSS THE REGION AT THE
START OF THE PERIOD...AND REMAIN SITUATED THROUGH MUCH OF THE WORK
WEEK AS IT SLOWLY MOVES EAST. SEVERAL VORT LOBES ARE ANTICIPATED TO
WRAP AROUND THIS UPPER LEVEL LOW ON TUESDAY AND WITH STEEPENING
LAPSE RATES...EXPECT SKY COVER TO INCREASE THROUGH THE DAY WHILE
SCATTERED SHOWERS BECOME POSSIBLE...ESPECIALLY ACROSS NORTHERN
ILLINOIS. AS THIS OCCURS...LIKELY DEEP MIXING WITH STRONG FLOW ALOFT
WILL ALLOW FOR ANOTHER WINDY DAY. GUIDANCE IS SUGGESTING THAT
ADVISORY CONDITIONS COULD BE REACHED IN THE AFTERNOON...AND WILL
NEED TO CONTINUE MONITORING THIS POTENTIAL. ANY REMAINING PRECIP AND
CLOUD COVER SHOULD EXIT THE AREA TUESDAY NIGHT WITH DRY CONDITIONS
EXPECTED. SOME GUIDANCE DEVELOPS A SWATH OF PRECIP OVER THE CWA LATE
IN THE NIGHT INTO EARLY WEDNESDAY. HOWEVER...A MORE LIKELY SCENARIO
AT THIS TIME WOULD BE FOR DRY CONDITIONS AND SO HAVE LEFT OUT ANY
POPS AT THIS TIME. ONGOING CAA WILL MAKE FOR CHILLY CONDITIONS
TUESDAY NIGHT...WITH LOW TEMPS IN THE 30S. IF PRECIP WERE TO OCCUR
DURING THIS PERIOD...THESE COLDER CONDITIONS COULD SUPPORT THE
POTENTIAL FOR AT LEAST A RAIN SNOW MIX ACROSS NORTHERN ILLINOIS.
EXPECT DRY CONDITIONS WITH BELOW NORMAL TEMPS THROUGH THE REST OF
THE FORECAST PERIOD...WITH FORECAST HIGHS IN THE 50S. COLD NIGHT
TIME LOWS IN THE 30S COULD BECOME AN ISSUE LATE IN THE WORK WEEK AS
HIGH PRESSURE IS ANTICIPATED TO MOVE OVERHEAD...WITH LIGHTER WINDS
AND THE COLD TEMPS POSSIBLY CREATING A SETUP FOR FROST.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* EAST-NORTHEAST WINDS AROUND 10 KT MOST OF THE TIME THROUGH 02Z.
* LIGHT TO MODERATE RAIN THROUGH 02Z THEN BECOMING SCATTERED
SHOWERS.
* IFR CIGS LOWERING TO LIFR THIS EVENING AND PERSISTING INTO AT
LEAST EARLY OVERNIGHT.
* GRADUALLY LOWERING VISIBILITY THIS EVE. THE POTENTIAL EXISTS FOR
A RAPID DROP DUE TO LAKE ENHANCED FOG MOVING INLAND BETWEEN
0130Z-0400Z.
* ANOTHER ROUND OF -SHRA PROBABLE MONDAY MORNING.
* GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT LATE MONDAY MORNING
AND AFTERNOON.
//DISCUSSION...UPDATED 00Z...
A SHIELD OF RAIN AND AT TIMES RAIN SHOWERS WILL CONTINUE TO
ADVANCE NORTHWARD ACROSS THE TAF SITES THROUGH MID-EVENING.
VISIBILITY WILL SHOW SOME FLUCTUATIONS IN THIS RAIN...MAINLY
BETWEEN 3SM AND 5SM. AS THE RAIN BECOMES MORE SCATTERED SHOWERS
AFTER 02-03ZZ AND A LIGHTER WIND FLOW NEAR LOW PRESSURE
OCCURS...THE SATURATION IS EXPECTED TO BRING LIFR CONDITIONS. THIS
IS ALREADY BEING OBSERVED UPSTREAM IN CENTRAL AND EASTERN IL.
CONFIDENCE IS HIGHEST IN LIFR CIGS BUT VISIBILITY UNDER 1SM IS
ALSO POSSIBLE...ESPECIALLY AT TAF SITES NOT FAR FROM THE LAKE
INCLUDING ORD AND MDW. ALREADY WEBCAM IMAGERY FROM DOWNTOWN
CHICAGO SHOWS WHAT IS LIKELY PART LAKE ENHANCED SUB 1SM FOG AND
WITH CONTINUED NORTHEAST WINDS THIS EVE...THIS IS POSSIBLE THIS
ROLLS INTO ORD AND MDW IN THE WAKE OF THE SHOWERS.
LATER TONIGHT WESTERLY WINDS WILL BEGIN AND THIS MAY RESULT IN A
GRADUAL IMPROVEMENT BY DAYBREAK. SOON AFTER SUNRISE THE COLD FRONT
IS EXPECTED TO MOVE OVER CHICAGO WITH WESTERLY WINDS INCREASING.
THERE WILL BE LIKELY AN AREA OF SHOWERS TOO IN THE MORNING...BUT
OVERALL CIGS AND VISIBILITY SHOULD BE IMPROVING INTO THE MVFR
CATEGORY. THE PATTERN BEHIND THE COLD FRONT FAVORS GUSTY WINDS
WHICH ARE BEING OBSERVED ACROSS THE PLAINS STATES TODAY. SPORADIC
PEAK GUSTS OF 30 KT ARE EXPECTED BETWEEN 16Z-22Z.
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH IN WIND DIRECTION THROUGH THE TAF. MEDIUM-HIGH IN SPEED.
* HIGH IN RAIN TIMING.
* HIGH IN CIGS. MEDIUM IN CIGS ONLY DROPPING AS FAR AS 500FT AND
TIMING. HIGH IN IFR CIG DURATION.
* HIGH IN IFR VISIBILITY OCCURRING FROM MID-EVE INTO OVERNIGHT.
LOW- MEDIUM IN SPECIFIC TIMING AND HOW FAR VISIBILITY WILL DROP.
LOW ON WHETHER LESS THAN 1SM VISIBILITY WILL OCCUR.
* MEDIUM IN CIGS/VISBYS AND SHRA DURING THE MORNING RUSH ON
MONDAY.
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...SLIGHT CHANCE OF SHRA AND MVFR. GUSTY WEST WINDS.
WEDNESDAY-THURSDAY...VFR. NORTHWEST WINDS.
FRIDAY-SATURDAY...VFR. WINDS BECOMING NORTHEAST.
MTF
&&
.MARINE...
324 PM CDT
AS A TROUGH OF LOW PRESSURE AND SECONDARY LOW PRESSURE CENTER
MOVE ACROSS THE GREAT LAKES REGION TONIGHT...WINDS WILL LIKELY BE
VARIABLE AT TIMES. THIS WILL ESPECIALLY BE THE CASE OVER THE
SOUTHERN HALF OF THE LAKE WHERE THE LOW PRESSURE SYSTEM IS
EXPECTED TO MOVE THROUGH. IN THE NEAR TERM...EAST NORTHEAST WINDS
WILL PREVAIL OVER THE LAKE WITH THE HIGHEST SPEEDS TO 30 KT
OCCURRING OVER THE NORTHERN HALF AND WHILE 15 TO 25 KT WINDS ARE
BEING OBSERVED OVER THE SOUTH...WITH SPEEDS EXPECTED TO SLIGHTLY
DIMINISH TONIGHT. AS THIS TROUGH/LOW EXIT TO THE EAST ON
MONDAY...STRONGER WESTERLY WINDS WILL DEVELOP. HIGHEST WINDS TO 30
KT WILL OCCUR ALONG THE NEARSHORE WATERS WHILE ONLY 15 TO 25 KT
ARE LIKELY OVER THE OPEN WATERS. A SIMILAR SETUP IS EXPECTED ON
TUESDAY BUT WITH SPEEDS SLIGHTLY HIGHER...AS TO 30 KT WILL LIKELY
PREVAIL FOR BOTH LOCATIONS AND WITH EVEN GALES POSSIBLE ALONG THE
NEARSHORE WATERS DURING THE DAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...11 AM MONDAY TO 9 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
NWS CHICAGO/ROMEOVILLE IL
643 PM CDT SUN APR 19 2015
.SHORT TERM...
319 PM CDT
THROUGH MONDAY NIGHT...
AFTER ANOTHER WARM EARLY AFTERNOON ACROSS MUCH OF THE REGION RAIN IS
BEGINNING TO SPREAD NORTHWARD ACROSS SOUTHERN SECTIONS OF THE CHICAGO
METRO AREA AS OF THIS WRITING. THIS ACTIVITY WILL CONTINUE TO
OVERSPREAD THE REGION THROUGH THE AFTERNOON AND EVENING...WITH
TEMPERATURES LIKELY TO DROP BACK INTO THE UPPER 50S AND LOW 60S IN
THE RAIN.
THE MID-LEVEL DISTURBANCE...AND THE ASSOCIATED SURFACE SYSTEM WILL
QUICKLY SHIFT NORTHWARD OVER LOWER MICHIGAN OVERNIGHT...AND IT
APPEARS THAT THE RAIN WILL BECOME MORE SHOWERY AND INTERMITTENT OR
POSSIBLY JUST SOME DRIZZLE LATER THIS EVENING AND INTO THE EARLY
MORNING ACROSS MUCH OF THE AREA AS THIS INITIAL MID LEVEL
DISTURBANCE SHIFTS NORTH OF THE AREA AND SOME DRIER MID LEVEL AIR
SHIFTS OVER THE SOUTHEASTERN HALF OF MY AREA. SOME ADDITIONAL RAIN
SHOWERS ARE POSSIBLE AGAIN EARLY MONDAY WITHIN A REGION OF MID LEVEL
DEFORMATION AND RAP AROUND MOISTURE ASSOCIATED WITH THE DEEPENING
LOWER AND MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION AND
SOUTHERN CANADA.
CONDITIONS SHOULD DRY OUT MONDAY AFTERNOON...WITH ONLY A SMALL
CHANCE OF AN ADDITIONAL SHOWER DEVELOPING AS COLDER AIR ALOFT
STEEPENS THE LOWER LEVEL LAPSE RATES. THE MAIN STORY DURING THE
AFTERNOON WILL BE THE WINDS. WINDS ARE EXPECTED TO INCREASE OUT OF
THE WEST-NORTHWEST DURING THE DAY AS STOUT SURFACE PRESSURE
GRADIENT SETS UP OVER THE REGION AS THE SURFACE LOW DEEPENS TO
AROUND 985 MB ACROSS ONTARIO MONDAY AFTERNOON. MODEL SOUNDINGS
SUGGEST GOOD AFTERNOON MIXING TO AROUND 850 MB SHOULD ALLOW FOR
GUSTS OF AROUND 30 KT AT TIMES...ESPECIALLY DURING THE AFTERNOON.
THESE WIND GUSTS SHOULD ABATE MONDAY EVENING...BUT STRONG WINDS
LOOK TO DEVELOP AGAIN ON TUESDAY. SEE LONG TERM DISCUSSION FOR
MORE INFO ON TUESDAY`S WINDS.
KJB
&&
.LONG TERM...
319 PM CDT
TUESDAY THROUGH SUNDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH BELOW NORMAL TEMPS
THROUGH THE FORECAST.
LARGE UPPER LEVEL CENTER WILL BE CENTERED ACROSS THE REGION AT THE
START OF THE PERIOD...AND REMAIN SITUATED THROUGH MUCH OF THE WORK
WEEK AS IT SLOWLY MOVES EAST. SEVERAL VORT LOBES ARE ANTICIPATED TO
WRAP AROUND THIS UPPER LEVEL LOW ON TUESDAY AND WITH STEEPENING
LAPSE RATES...EXPECT SKY COVER TO INCREASE THROUGH THE DAY WHILE
SCATTERED SHOWERS BECOME POSSIBLE...ESPECIALLY ACROSS NORTHERN
ILLINOIS. AS THIS OCCURS...LIKELY DEEP MIXING WITH STRONG FLOW ALOFT
WILL ALLOW FOR ANOTHER WINDY DAY. GUIDANCE IS SUGGESTING THAT
ADVISORY CONDITIONS COULD BE REACHED IN THE AFTERNOON...AND WILL
NEED TO CONTINUE MONITORING THIS POTENTIAL. ANY REMAINING PRECIP AND
CLOUD COVER SHOULD EXIT THE AREA TUESDAY NIGHT WITH DRY CONDITIONS
EXPECTED. SOME GUIDANCE DEVELOPS A SWATH OF PRECIP OVER THE CWA LATE
IN THE NIGHT INTO EARLY WEDNESDAY. HOWEVER...A MORE LIKELY SCENARIO
AT THIS TIME WOULD BE FOR DRY CONDITIONS AND SO HAVE LEFT OUT ANY
POPS AT THIS TIME. ONGOING CAA WILL MAKE FOR CHILLY CONDITIONS
TUESDAY NIGHT...WITH LOW TEMPS IN THE 30S. IF PRECIP WERE TO OCCUR
DURING THIS PERIOD...THESE COLDER CONDITIONS COULD SUPPORT THE
POTENTIAL FOR AT LEAST A RAIN SNOW MIX ACROSS NORTHERN ILLINOIS.
EXPECT DRY CONDITIONS WITH BELOW NORMAL TEMPS THROUGH THE REST OF
THE FORECAST PERIOD...WITH FORECAST HIGHS IN THE 50S. COLD NIGHT
TIME LOWS IN THE 30S COULD BECOME AN ISSUE LATE IN THE WORK WEEK AS
HIGH PRESSURE IS ANTICIPATED TO MOVE OVERHEAD...WITH LIGHTER WINDS
AND THE COLD TEMPS POSSIBLY CREATING A SETUP FOR FROST.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* EAST-NORTHEAST WINDS AROUND 10 KT MOST OF THE TIME THROUGH 02Z.
* LIGHT TO MODERATE RAIN THROUGH 02Z THEN BECOMING SCATTERED
SHOWERS.
* IFR CIGS LOWERING TO LIFR THIS EVENING AND PERSISTING INTO AT
LEAST EARLY OVERNIGHT.
* GRADUALLY LOWERING VISIBILITY THIS EVE. THE POTENTIAL EXISTS FOR
A RAPID DROP DUE TO LAKE ENHANCED FOG MOVING INLAND BETWEEN
0130Z-0400Z.
* ANOTHER ROUND OF -SHRA PROBABLE MONDAY MORNING.
* GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT LATE MONDAY MORNING
AND AFTERNOON.
//DISCUSSION...UPDATED 00Z...
A SHIELD OF RAIN AND AT TIMES RAIN SHOWERS WILL CONTINUE TO
ADVANCE NORTHWARD ACROSS THE TAF SITES THROUGH MID-EVENING.
VISIBILITY WILL SHOW SOME FLUCTUATIONS IN THIS RAIN...MAINLY
BETWEEN 3SM AND 5SM. AS THE RAIN BECOMES MORE SCATTERED SHOWERS
AFTER 02-03ZZ AND A LIGHTER WIND FLOW NEAR LOW PRESSURE
OCCURS...THE SATURATION IS EXPECTED TO BRING LIFR CONDITIONS. THIS
IS ALREADY BEING OBSERVED UPSTREAM IN CENTRAL AND EASTERN IL.
CONFIDENCE IS HIGHEST IN LIFR CIGS BUT VISIBILITY UNDER 1SM IS
ALSO POSSIBLE...ESPECIALLY AT TAF SITES NOT FAR FROM THE LAKE
INCLUDING ORD AND MDW. ALREADY WEBCAM IMAGERY FROM DOWNTOWN
CHICAGO SHOWS WHAT IS LIKELY PART LAKE ENHANCED SUB 1SM FOG AND
WITH CONTINUED NORTHEAST WINDS THIS EVE...THIS IS POSSIBLE THIS
ROLLS INTO ORD AND MDW IN THE WAKE OF THE SHOWERS.
LATER TONIGHT WESTERLY WINDS WILL BEGIN AND THIS MAY RESULT IN A
GRADUAL IMPROVEMENT BY DAYBREAK. SOON AFTER SUNRISE THE COLD FRONT
IS EXPECTED TO MOVE OVER CHICAGO WITH WESTERLY WINDS INCREASING.
THERE WILL BE LIKELY AN AREA OF SHOWERS TOO IN THE MORNING...BUT
OVERALL CIGS AND VISIBILITY SHOULD BE IMPROVING INTO THE MVFR
CATEGORY. THE PATTERN BEHIND THE COLD FRONT FAVORS GUSTY WINDS
WHICH ARE BEING OBSERVED ACROSS THE PLAINS STATES TODAY. SPORADIC
PEAK GUSTS OF 30 KT ARE EXPECTED BETWEEN 16Z-22Z.
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH IN WIND DIRECTION THROUGH THE TAF. MEDIUM-HIGH IN SPEED.
* HIGH IN RAIN TIMING.
* HIGH IN CIGS. MEDIUM IN CIGS ONLY DROPPING AS FAR AS 500FT AND
TIMING. HIGH IN IFR CIG DURATION.
* HIGH IN IFR VISIBILITY OCCURRING FROM MID-EVE INTO OVERNIGHT.
LOW- MEDIUM IN SPECIFIC TIMING AND HOW FAR VISIBILITY WILL DROP.
LOW ON WHETHER LESS THAN 1SM VISIBILITY WILL OCCUR.
* MEDIUM IN CIGS/VISBYS AND SHRA DURING THE MORNING RUSH ON
MONDAY.
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...SLIGHT CHANCE OF SHRA AND MVFR. GUSTY WEST WINDS.
WEDNESDAY-THURSDAY...VFR. NORTHWEST WINDS.
FRIDAY-SATURDAY...VFR. WINDS BECOMING NORTHEAST.
MTF
&&
.MARINE...
324 PM CDT
AS A TROUGH OF LOW PRESSURE AND SECONDARY LOW PRESSURE CENTER
MOVE ACROSS THE GREAT LAKES REGION TONIGHT...WINDS WILL LIKELY BE
VARIABLE AT TIMES. THIS WILL ESPECIALLY BE THE CASE OVER THE
SOUTHERN HALF OF THE LAKE WHERE THE LOW PRESSURE SYSTEM IS
EXPECTED TO MOVE THROUGH. IN THE NEAR TERM...EAST NORTHEAST WINDS
WILL PREVAIL OVER THE LAKE WITH THE HIGHEST SPEEDS TO 30 KT
OCCURRING OVER THE NORTHERN HALF AND WHILE 15 TO 25 KT WINDS ARE
BEING OBSERVED OVER THE SOUTH...WITH SPEEDS EXPECTED TO SLIGHTLY
DIMINISH TONIGHT. AS THIS TROUGH/LOW EXIT TO THE EAST ON
MONDAY...STRONGER WESTERLY WINDS WILL DEVELOP. HIGHEST WINDS TO 30
KT WILL OCCUR ALONG THE NEARSHORE WATERS WHILE ONLY 15 TO 25 KT
ARE LIKELY OVER THE OPEN WATERS. A SIMILAR SETUP IS EXPECTED ON
TUESDAY BUT WITH SPEEDS SLIGHTLY HIGHER...AS TO 30 KT WILL LIKELY
PREVAIL FOR BOTH LOCATIONS AND WITH EVEN GALES POSSIBLE ALONG THE
NEARSHORE WATERS DURING THE DAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...11 AM MONDAY TO 9 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
NWS TOPEKA KS
1249 PM CDT Sat Apr 18 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 342 AM CDT SAT APR 18 2015
Showers and thunderstorms developing this hour across northeast
Oklahoma into south central and north central Kansas, with cell
movement toward the north northwest and the cluster moving more
northerly. This area is forecast to move across the forecast area
through the morning hours today.
Struggle with the forecast continues to be timing and coverage of
precipitation chances. After initial energy lifts across Eastern
Kansas through early afternoon, next uncertainty will be for chances
later in the afternoon. HRRR develops a cluster of showers in south
central KS, but would anticipate a break between the systems with
subsidence behind the main wave inhibiting convective development.
Have higher chances in the morning, with lower chances middle
afternoon, followed by an increase from west to east through the
evening into the overnight hours as the main wave finally starts to
get an easterly push, from both a northern US shortwave and an upper
jet traversing the southern states. With a lull in precipitation
and possibly some better sunshine out west, this would boost
instability and chances for severe thunderstorms as late day storms
develop along the dryline to our west and along the northward
advancing warm front. Primary threat would be hail, but closer
proximity to these surface features in north central Kansas could
bring an isolated tornado risk there. General precipitation chances
continue in the overnight hours ahead of the upper low as it
continues to slowly move east. Highs for Saturday in the middle 70s
west to near 70 east, with lows in the 50s.
.LONG TERM...(Sunday through Friday)
Issued at 342 AM CDT SAT APR 18 2015
By Sunday morning the mid/upper low will be centered over SC KS and
NC OK as it progresses eastward. During this time the low will
become more of an open wave as another shortwave digs into the
northern plains and upper Midwest. These waves will bring a cold
front through the region during the day Sunday. In the morning the
better chance for showers and some thunder should be in southern KS
where the front and mid level low are more coupled in the vertical.
By 18Z the models are hinting at an increase of instability on the
order of about 1000 j/kg ahead of the front that should stretch
across eastern KS. Lapse rates are not overly impressive, and deep
layer shear could reach 30 kts. Although the better shear will be
further southeast over southern MO where the flow aloft is slightly
stronger. Therefore kept a mention of thunderstorms for east central
KS during the afternoon. A majority of the precip should clear the
area around 03Z in the evening.
A sharp pressure gradient behind the front will support northwest
surface winds around 15 to 25 mph with gusts as up to 35 mph
especially in NC KS. Cold air advection on the backside of the wave
drops temps into the lower 40s and upper 30s by Monday morning.
Winds do not completely decouple Sunday night so there is little
concern for frost. On Monday winds remain gusty with high temps
generally around 60 and partly sunny skies. Monday night will not be
the classic set up for frost with a expansive high building
southward, but the winds do decrease and temps are forecast to reach
the mid to upper 30s. Therefore could not rule out the possibility
for frost perhaps in preferred sheltered locations.
NW flow aloft develops over the region as the northern stream wave
deepens over the Great Lakes. The models are beginning to advertise
embedded shortwaves within the NW flow, which track over the plains
around mid week. This will bring small chances for either showers or
thunderstorms. Late in the week a southern wave crashes the southern
CA coast and tracks northeastward towards the center of the country.
There are some differences on how far north the instability reaches
ahead of the system, and there are additional waves in the NW flow
that could interfere with the southern stream system. Confidence in
any solution is low at this point.
&&
.AVIATION...(For the 18Z TAFs through 18Z Sunday Afternoon)
Issued at 1249 PM CDT SAT APR 18 2015
VFR conditions are expected outside of convective activity. MVFR
to areas of IFR are expected near MHK through 20Z then an
improvement to VFR by 21Z. SHRA will continue through 21Z at TOP
and FOE with MHK having a low probability of shra through 00Z.
High resolution short range models develop tsra in western and
central KS then move it northeast toward MHK by 06Z, then
affecting TOP and FOE after 09Z. WInds shift to the northwest in
the 14Z-16Z period.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...67
LONG TERM...Sanders
AVIATION...53
AREA FORECAST DISCUSSION
NWS WICHITA KS
1242 PM CDT SAT APR 18 2015
...UPDATED FOR 18Z AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 350 AM CDT SAT APR 18 2015
THE UPPER LOW HAS SHIFTED EASTWARD AND IS SPINNING OVER COLORADO.
SMALL PIECES OF ENERGY WITH IT HAVE HELPED TO SPARK OFF SHOWERS
AND THUNDERSTORMS OVER THE PLAINS STATES DURING THE OVERNIGHT
HOURS. EXPECT CENTRAL AND EASTERN KANSAS TO SEE SHOWERS AND
THUNDERSTORMS THROUGH MUCH OF THE MORNING.
BILLINGS WRIGHT
&&
.UPDATE...
ISSUED AT 1037 AM CDT SAT APR 18 2015
MAIN UPPER LEVEL LOW OVER THE CO ROCKIES IS BEGINNING TO MAKE SLOW
PROGRESS INTO THE PLAINS THIS MORNING. DIFFLUENT SW FLOW AHEAD OF
THIS UPPER LOW HAS LED TO ANOTHER ROUND OF SHOWERS AND EMBEDDED
STORMS OVER THE ERN HALF OF KS. EXPECT THE SHOWERS IN ERN KS TO
GRADUALLY SHIFT TO THE E-NE OF THE AREA LATE THIS MORNING. BUT
ATTENTION QUICKLY SHIFTS BACK TO THE WEST...AS THIS UPPER LOW BEGINS
TO PUSH EAST INTO WRN KS. ALREADY SEEING SOME CLEARING ACROSS THE
WESTERN HALF OF THE FORECAST AREA...WHICH WILL LEAD TO INCREASED
SURFACE HEATING INTO THE AFTERNOON HOURS. SETUP IS A LITTLE
DIFFERENT THAN YESTERDAY...AS DRYLINE IN SW KS IS ON THE MOVE TO THE
EAST THIS MORNING...CURRENTLY JUST TO THE WEST OF THE KDDC.
LATEST LOOK AT THE HI-RES SHORT TERM MODELS SUGGEST THAT THE
INCREASED HEATING BETWEEN THE DRYLINE AND WRN SECTIONS OF THE
FORECAST AREA WILL HELP DESTABILIZE THE ATMOSPHERE JUST TO THE WEST
OF THE FORECAST AREA THIS AFTERNOON. THIS AREA IS ALSO WEAKLY
CAPPED. SO BETTER HEATING THIS MORNING...AND NOT ALOT OF RECOVERY
TIME NEEDED...MAY LEAD TO CONVECTION DEVELOPING EARLIER THAN
YESTERDAY. ESPECIALLY JUST AHEAD OF THE DRYLINE AS IT PUSHES EAST OF
KDDC...AND PUSHES TO JUST WEST OF KPPT. SO MAY SEE CONVECTION
DEVELOP AND MOVE INTO WRN SECTIONS OF THE FORECAST AREA (WEST OF I-
135) BETWEEN 20-22Z. LATEST HRRR AND ARW SUGGEST THIS SCENARIO.
AS FAR AS SEVERE WEATHER CHANCES...BULK SHEAR AROUND 40 KTS AND
SBCAPE VALUES EXPECTED TO BE IN THE 2000-2500 J/KG SUGGEST A STRONG
TO SEVERE CHANCE WITH A MIXED MODE WITH MULTICELL CLUSTERS AND A FEW
LOW TOPPED SUPERCELLS WITH LARGE HAIL (QUARTER TO GOLFBALL) AND
DAMAGING WINDS THE MAIN CONCERN. CANNOT RULE OUT A WEAK/BRIEF
TORNADO OR TWO...GIVEN THE DIRECTIONAL SHEAR AND INCREASED VERTICAL
STRETCHING DUE TO THE STEEP LAPSE RATES.
KETCHAM
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 350 AM CDT SAT APR 18 2015
MORNING:
EXPECT THE SHOWERS AND THUNDERSTORMS CURRENTLY ONGOING TO CONTINUE
TO DEVELOP AND SHIFT EAST-NORTHEASTWARD DURING THE MORNING HOURS.
DO NOT EXPECT THESE TO BE STRONG OR SEVERE...JUST A WELCOME DRINK
OF RAIN.
THIS AFTERNOON/EVENING:
THINK THAT THERE MAY BE SOME CLEARING ACROSS WESTERN AREAS THIS
MORNING/EARLY AFTERNOON BEFORE THUNDERSTORMS FIRE AGAIN THIS
AFTERNOON ALONG AND AHEAD OF THE DRYLINE. STILL SLIGHTLY CONCERNED
THAT STORMS COULD FIRE EARLIER IN THE AFTERNOON...CLOSER TO 18Z
WITH THE SUPPORT FROM THE UPPER DYNAMICS OF THE UPPER
LOW...HOWEVER...THE BEST SUPPORT FOR COVERAGE IS CLOSER TO 21Z TO
00Z. EXPECT THESE STORMS TO IMPACT CENTRAL AND SOUTH CENTRAL
KANSAS WHERE INSTABILITY AND SHEAR PARAMETERS ARE PLENTIFUL TO
SUPPORT SUPERCELLS CAPABLE OF LARGE HAIL AND DAMAGING WIND. THERE
IS STILL A SMALL CHANCE FOR A TORNADO...BEST CHANCES RESIDE IN
SOUTH CENTRAL KANSAS AND CLOSER TO THE OKLAHOMA BORDER WITH THE
BETTER HELICITY/EHI FURTHER SOUTH IN OKLAHOMA. EXPECT STORMS TO
MOVE EASTWARD DURING THE EVENING. THE SEVERE CHANCES DECREASE
OVER SOUTHEAST KANSAS THOUGH AS THE PARAMETERS ARE LESS FAVORABLE
THERE TO SUPPORT SEVERE STORMS.
DURING THE OVERNIGHT HOURS SATURDAY INTO SUNDAY:
THE UPPER LOW WILL CONTINUE TO PUSH EASTWARD AND LOBES OF
VORTICITY ARE EXPECTED TO CIRCLE AROUND IT WHICH COULD SPARK
MULTIPLE ROUNDS OF SHOWERS/THUNDERSTORMS OVER SOUTHERN KANSAS. THE
UPPER LOW WILL TRAVERSE THE STATE SUNDAY...THUNDERSTORMS WILL
BECOME SHOWERS AND THE FOCUS WILL SHIFT TO EAST AND SOUTHEAST
KANSAS. A COLD FRONT ASSOCIATED WITH THE UPPER LOW WILL MOVE
ACROSS THE STATE AND SHIFT WINDS TO THE NORTHWEST AND GUSTY.
TEMPERATURES WILL BE COOLER ON MONDAY...IN THE 60S BUT THINGS
SHOULD BE DRY AS THE UPPER LOW SLOWLY BEGINS TO SHIFT
NORTHEASTWARD.
BILLINGS WRIGHT
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 350 AM CDT SAT APR 18 2015
THE MAIN UPPER LOW IS SLOW TO EXIT AND A PIECE OF ENERGY ROTATING
AROUND ITS BACK SIDE IT WILL IMPACT THE AREA WHILE THE CENTRAL
PLAINS SITS UNDER NORTHWESTERLY UPPER LEVEL FLOW. PRECIPITATION
CHANCES WILL BE POSSIBLE EARLY TUESDAY AND THROUGHOUT THE
DAY...BUT THE GUIDANCE HAS DISCREPANCIES AMONGST THE LOCATION OF
THE PRECIPITATION...THINK IT COULD BE SOUTH OF THE STATE
LINE...HOWEVER THE GFS PUSHES IT RIGHT OVER CENTRAL KANSAS.
CONFIDENCE ON THIS PERIOD AND PRECIPITATION CHANCES IS LOW.
BY WEDNESDAY THROUGH FRIDAY THE UPPER LOW MOVES OFF TO THE
NORTHEAST AND ANOTHER SYSTEM MOVES IN FROM THE SOUTHWEST.
PRECIPITATION AND POSSIBLY THUNDERSTORM CHANCES INCREASE BY
WEDNESDAY THROUGH FRIDAY ACROSS THE AREA. THIS PERIOD HAS QUITE A
FEW DISCREPANCIES WITH THE VARIOUS SOLUTIONS...CONFIDENCE ON ANY
SOLUTION IS LOW.
TEMPERATURES WILL STAY IN THE UPPER 60S AND LOW 70S...NEAR
SEASONAL NORMALS.
BILLINGS WRIGHT
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1240 PM CDT SAT APR 18 2015
A RATHER DIFFICULT AVIATION FORECAST...AS AN UPPER LEVEL SYSTEM
CURRENTLY OVER ERN CO WILL LEAD TO LOTS OF LOW LEVEL MOISTURE ACROSS
MOST OF THE FORECAST AREA. AS LIFT FROM THIS LOW INCREASES...EXPECT
SHRA/TSRA TO DEVELOP IN THIS UNSTABLE ATMOSPHERE ACROSS MOST OF THE
FORECAST AREA AFTER 22Z/SAT. SO PLAN ON GOING WITH VCTS FOR MOST
LOCATIONS FOR THIS CHANCE. ALSO WILL GO WITH A TEMPO GROUP FOR MVFR
VSBYS IN AND AROUND THE STRONGER STORMS NEAR THE KICT/KHUT AND KRSL
TAF SITES.
EXPECT THE THUNDER CHANCES TO CONTINUE WELL INTO THE EVENING
HOURS...ESPECIALLY FOR AREAS NEAR THE KICT/KHUT/KSLN AND KRSL TAF
SITES.
KCNU WILL SEE A LATER ARRIVAL FOR THE VCTS....TO AROUND 06Z. THE
DEEPER LOW LEVEL MOISTURE COULD LEAD TO SOME MVFR CIGS AS WELL.
EXPECT A GRADUAL WIND SHIFT TO THE WEST FOR THE KRSL TAF BY SUN
MORNING.
KETCHAM
&&
.FIRE WEATHER...
ISSUED AT 350 AM CDT SAT APR 18 2015
FIRE WEATHER CONCERNS REMAIN LOW WITH THE UPPER LEVEL SYSTEM
IMPACTING THE AREA CAUSING MULTIPLE ROUNDS OF PRECIPITATION.
THE GRASSLAND FIRE DANGER INDEX REMAINS BELOW ELEVATED CONCERN
LEVELS.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 75 54 66 39 / 50 60 70 10
HUTCHINSON 75 52 62 39 / 50 60 70 10
NEWTON 73 52 62 40 / 50 60 80 10
ELDORADO 74 54 69 41 / 40 60 80 10
WINFIELD-KWLD 74 54 70 40 / 40 60 70 10
RUSSELL 75 51 59 36 / 50 60 60 10
GREAT BEND 74 50 59 35 / 50 60 60 10
SALINA 76 52 61 38 / 50 60 70 10
MCPHERSON 74 52 60 38 / 50 60 70 10
COFFEYVILLE 73 56 70 43 / 80 60 80 20
CHANUTE 72 56 70 42 / 80 60 80 20
IOLA 71 56 69 42 / 80 60 80 20
PARSONS-KPPF 73 56 69 42 / 80 60 80 20
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1039 AM CDT SAT APR 18 2015
.SYNOPSIS...
ISSUED AT 350 AM CDT SAT APR 18 2015
THE UPPER LOW HAS SHIFTED EASTWARD AND IS SPINNING OVER COLORADO.
SMALL PIECES OF ENERGY WITH IT HAVE HELPED TO SPARK OFF SHOWERS
AND THUNDERSTORMS OVER THE PLAINS STATES DURING THE OVERNIGHT
HOURS. EXPECT CENTRAL AND EASTERN KANSAS TO SEE SHOWERS AND
THUNDERSTORMS THROUGH MUCH OF THE MORNING.
BILLINGS WRIGHT
&&
.UPDATE...
ISSUED AT 1037 AM CDT SAT APR 18 2015
MAIN UPPER LEVEL LOW OVER THE CO ROCKIES IS BEGINNING TO MAKE SLOW
PROGRESS INTO THE PLAINS THIS MORNING. DIFFLUENT SW FLOW AHEAD OF
THIS UPPER LOW HAS LED TO ANOTHER ROUND OF SHOWERS AND EMBEDDED
STORMS OVER THE ERN HALF OF KS. EXPECT THE SHOWERS IN ERN KS TO
GRADUALLY SHIFT TO THE E-NE OF THE AREA LATE THIS MORNING. BUT
ATTENTION QUICKLY SHIFTS BACK TO THE WEST...AS THIS UPPER LOW BEGINS
TO PUSH EAST INTO WRN KS. ALREADY SEEING SOME CLEARING ACROSS THE
WESTERN HALF OF THE FORECAST AREA...WHICH WILL LEAD TO INCREASED
SURFACE HEATING INTO THE AFTERNOON HOURS. SETUP IS A LITTLE
DIFFERENT THAN YESTERDAY...AS DRYLINE IN SW KS IS ON THE MOVE TO THE
EAST THIS MORNING...CURRENTLY JUST TO THE WEST OF THE KDDC.
LATEST LOOK AT THE HI-RES SHORT TERM MODELS SUGGEST THAT THE
INCREASED HEATING BETWEEN THE DRYLINE AND WRN SECTIONS OF THE
FORECAST AREA WILL HELP DESTABILIZE THE ATMOSPHERE JUST TO THE WEST
OF THE FORECAST AREA THIS AFTERNOON. THIS AREA IS ALSO WEAKLY
CAPPED. SO BETTER HEATING THIS MORNING...AND NOT ALOT OF RECOVERY
TIME NEEDED...MAY LEAD TO CONVECTION DEVELOPING EARLIER THAN
YESTERDAY. ESPECIALLY JUST AHEAD OF THE DRYLINE AS IT PUSHES EAST OF
KDDC...AND PUSHES TO JUST WEST OF KPPT. SO MAY SEE CONVECTION
DEVELOP AND MOVE INTO WRN SECTIONS OF THE FORECAST AREA (WEST OF I-
135) BETWEEN 20-22Z. LATEST HRRR AND ARW SUGGEST THIS SCENARIO.
AS FAR AS SEVERE WEATHER CHANCES...BULK SHEAR AROUND 40 KTS AND
SBCAPE VALUES EXPECTED TO BE IN THE 2000-2500 J/KG SUGGEST A STRONG
TO SEVERE CHANCE WITH A MIXED MODE WITH MULTICELL CLUSTERS AND A FEW
LOW TOPPED SUPERCELLS WITH LARGE HAIL (QUARTER TO GOLFBALL) AND
DAMAGING WINDS THE MAIN CONCERN. CANNOT RULE OUT A WEAK/BRIEF
TORNADO OR TWO...GIVEN THE DIRECTIONAL SHEAR AND INCREASED VERTICAL
STRETCHING DUE TO THE STEEP LAPSE RATES.
KETCHAM
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 350 AM CDT SAT APR 18 2015
MORNING:
EXPECT THE SHOWERS AND THUNDERSTORMS CURRENTLY ONGOING TO CONTINUE
TO DEVELOP AND SHIFT EAST-NORTHEASTWARD DURING THE MORNING HOURS.
DO NOT EXPECT THESE TO BE STRONG OR SEVERE...JUST A WELCOME DRINK
OF RAIN.
THIS AFTERNOON/EVENING:
THINK THAT THERE MAY BE SOME CLEARING ACROSS WESTERN AREAS THIS
MORNING/EARLY AFTERNOON BEFORE THUNDERSTORMS FIRE AGAIN THIS
AFTERNOON ALONG AND AHEAD OF THE DRYLINE. STILL SLIGHTLY CONCERNED
THAT STORMS COULD FIRE EARLIER IN THE AFTERNOON...CLOSER TO 18Z
WITH THE SUPPORT FROM THE UPPER DYNAMICS OF THE UPPER
LOW...HOWEVER...THE BEST SUPPORT FOR COVERAGE IS CLOSER TO 21Z TO
00Z. EXPECT THESE STORMS TO IMPACT CENTRAL AND SOUTH CENTRAL
KANSAS WHERE INSTABILITY AND SHEAR PARAMETERS ARE PLENTIFUL TO
SUPPORT SUPERCELLS CAPABLE OF LARGE HAIL AND DAMAGING WIND. THERE
IS STILL A SMALL CHANCE FOR A TORNADO...BEST CHANCES RESIDE IN
SOUTH CENTRAL KANSAS AND CLOSER TO THE OKLAHOMA BORDER WITH THE
BETTER HELICITY/EHI FURTHER SOUTH IN OKLAHOMA. EXPECT STORMS TO
MOVE EASTWARD DURING THE EVENING. THE SEVERE CHANCES DECREASE
OVER SOUTHEAST KANSAS THOUGH AS THE PARAMETERS ARE LESS FAVORABLE
THERE TO SUPPORT SEVERE STORMS.
DURING THE OVERNIGHT HOURS SATURDAY INTO SUNDAY:
THE UPPER LOW WILL CONTINUE TO PUSH EASTWARD AND LOBES OF
VORTICITY ARE EXPECTED TO CIRCLE AROUND IT WHICH COULD SPARK
MULTIPLE ROUNDS OF SHOWERS/THUNDERSTORMS OVER SOUTHERN KANSAS. THE
UPPER LOW WILL TRAVERSE THE STATE SUNDAY...THUNDERSTORMS WILL
BECOME SHOWERS AND THE FOCUS WILL SHIFT TO EAST AND SOUTHEAST
KANSAS. A COLD FRONT ASSOCIATED WITH THE UPPER LOW WILL MOVE
ACROSS THE STATE AND SHIFT WINDS TO THE NORTHWEST AND GUSTY.
TEMPERATURES WILL BE COOLER ON MONDAY...IN THE 60S BUT THINGS
SHOULD BE DRY AS THE UPPER LOW SLOWLY BEGINS TO SHIFT
NORTHEASTWARD.
BILLINGS WRIGHT
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 350 AM CDT SAT APR 18 2015
THE MAIN UPPER LOW IS SLOW TO EXIT AND A PIECE OF ENERGY ROTATING
AROUND ITS BACK SIDE IT WILL IMPACT THE AREA WHILE THE CENTRAL
PLAINS SITS UNDER NORTHWESTERLY UPPER LEVEL FLOW. PRECIPITATION
CHANCES WILL BE POSSIBLE EARLY TUESDAY AND THROUGHOUT THE
DAY...BUT THE GUIDANCE HAS DISCREPANCIES AMONGST THE LOCATION OF
THE PRECIPITATION...THINK IT COULD BE SOUTH OF THE STATE
LINE...HOWEVER THE GFS PUSHES IT RIGHT OVER CENTRAL KANSAS.
CONFIDENCE ON THIS PERIOD AND PRECIPITATION CHANCES IS LOW.
BY WEDNESDAY THROUGH FRIDAY THE UPPER LOW MOVES OFF TO THE
NORTHEAST AND ANOTHER SYSTEM MOVES IN FROM THE SOUTHWEST.
PRECIPITATION AND POSSIBLY THUNDERSTORM CHANCES INCREASE BY
WEDNESDAY THROUGH FRIDAY ACROSS THE AREA. THIS PERIOD HAS QUITE A
FEW DISCREPANCIES WITH THE VARIOUS SOLUTIONS...CONFIDENCE ON ANY
SOLUTION IS LOW.
TEMPERATURES WILL STAY IN THE UPPER 60S AND LOW 70S...NEAR
SEASONAL NORMALS.
BILLINGS WRIGHT
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 653 AM CDT SAT APR 18 2015
TOUGH AVIATION FORECAST. CONFIDENCE ONCE AGAIN NOT PARTICULARLY
HIGH GIVEN CHALLENGES OF WEAKLY CAPPED/WEAK SURFACE CONVERGENCE
PATTERN. STORMS WILL PERSIST FOR A FEW HOURS AT KCNU...WHILE
REMAINDER OF THE AREA MORE THAN LIKELY DRY DURING THE MORNING.
UPPER LOW HAS DRIFTED A BIT CLOSER...SO ONSET OF RENEWED
CONVECTION MAY BE A BIT QUICKER THAN YESTERDAY...BUT STILL
THINKING LATER IN THE AFTERNOON IN AT KRSL/KHUT...WITH KICT/KSLN
VERY LATE AFTERNOON/EVENING AND KCNU LATER TONIGHT. -HOWERTON
&&
.FIRE WEATHER...
ISSUED AT 350 AM CDT SAT APR 18 2015
FIRE WEATHER CONCERNS REMAIN LOW WITH THE UPPER LEVEL SYSTEM
IMPACTING THE AREA CAUSING MULTIPLE ROUNDS OF PRECIPITATION.
THE GRASSLAND FIRE DANGER INDEX REMAINS BELOW ELEVATED CONCERN
LEVELS.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 75 54 66 39 / 50 60 70 10
HUTCHINSON 75 52 62 39 / 50 60 70 10
NEWTON 73 52 62 40 / 50 60 80 10
ELDORADO 74 54 69 41 / 40 60 80 10
WINFIELD-KWLD 74 54 70 40 / 40 60 70 10
RUSSELL 75 51 59 36 / 50 60 60 10
GREAT BEND 74 50 59 35 / 50 60 60 10
SALINA 76 52 61 38 / 50 60 70 10
MCPHERSON 74 52 60 38 / 50 60 70 10
COFFEYVILLE 73 56 70 43 / 80 60 80 20
CHANUTE 72 56 70 42 / 80 60 80 20
IOLA 71 56 69 42 / 80 60 80 20
PARSONS-KPPF 73 56 69 42 / 80 60 80 20
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
629 AM CDT Sat Apr 18 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 342 AM CDT SAT APR 18 2015
Showers and thunderstorms developing this hour across northeast
Oklahoma into south central and north central Kansas, with cell
movement toward the north northwest and the cluster moving more
northerly. This area is forecast to move across the forecast area
through the morning hours today.
Struggle with the forecast continues to be timing and coverage of
precipitation chances. After initial energy lifts across Eastern
Kansas through early afternoon, next uncertainty will be for chances
later in the afternoon. HRRR develops a cluster of showers in south
central KS, but would anticipate a break between the systems with
subsidence behind the main wave inhibiting convective development.
Have higher chances in the morning, with lower chances middle
afternoon, followed by an increase from west to east through the
evening into the overnight hours as the main wave finally starts to
get an easterly push, from both a northern US shortwave and an upper
jet traversing the southern states. With a lull in precipitation
and possibly some better sunshine out west, this would boost
instability and chances for severe thunderstorms as late day storms
develop along the dryline to our west and along the northward
advancing warm front. Primary threat would be hail, but closer
proximity to these surface features in north central Kansas could
bring an isolated tornado risk there. General precipitation chances
continue in the overnight hours ahead of the upper low as it
continues to slowly move east. Highs for Saturday in the middle 70s
west to near 70 east, with lows in the 50s.
.LONG TERM...(Sunday through Friday)
Issued at 342 AM CDT SAT APR 18 2015
By Sunday morning the mid/upper low will be centered over SC KS and
NC OK as it progresses eastward. During this time the low will
become more of an open wave as another shortwave digs into the
northern plains and upper Midwest. These waves will bring a cold
front through the region during the day Sunday. In the morning the
better chance for showers and some thunder should be in southern KS
where the front and mid level low are more coupled in the vertical.
By 18Z the models are hinting at an increase of instability on the
order of about 1000 j/kg ahead of the front that should stretch
across eastern KS. Lapse rates are not overly impressive, and deep
layer shear could reach 30 kts. Although the better shear will be
further southeast over southern MO where the flow aloft is slightly
stronger. Therefore kept a mention of thunderstorms for east central
KS during the afternoon. A majority of the precip should clear the
area around 03Z in the evening.
A sharp pressure gradient behind the front will support northwest
surface winds around 15 to 25 mph with gusts as up to 35 mph
especially in NC KS. Cold air advection on the backside of the wave
drops temps into the lower 40s and upper 30s by Monday morning.
Winds do not completely decouple Sunday night so there is little
concern for frost. On Monday winds remain gusty with high temps
generally around 60 and partly sunny skies. Monday night will not be
the classic set up for frost with a expansive high building
southward, but the winds do decrease and temps are forecast to reach
the mid to upper 30s. Therefore could not rule out the possibility
for frost perhaps in preferred sheltered locations.
NW flow aloft develops over the region as the northern stream wave
deepens over the Great Lakes. The models are beginning to advertise
embedded shortwaves within the NW flow, which track over the plains
around mid week. This will bring small chances for either showers or
thunderstorms. Late in the week a southern wave crashes the southern
CA coast and tracks northeastward towards the center of the country.
There are some differences on how far north the instability reaches
ahead of the system, and there are additional waves in the NW flow
that could interfere with the southern stream system. Confidence in
any solution is low at this point.
&&
.AVIATION...(For the 12Z TAFs through 12Z Sunday Morning)
Issued at 624 AM CDT SAT APR 18 2015
TAFs are generally VFR as first round of rain and isolated thunder
move across the area in the morning. Another round is expected
later this evening as storms develop west of the terminals and
move east. Coverage in between expected to be sporadic and won`t
mention more than VCTS at this time for the afternoon evening
hours.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...67
LONG TERM...Sanders
AVIATION...67
AREA FORECAST DISCUSSION
NWS TOPEKA KS
343 AM CDT Sat Apr 18 2015
.SHORT TERM...(Today and Tonight)
Issued at 342 AM CDT SAT APR 18 2015
Showers and thunderstorms developing this hour across northeast
Oklahoma into south central and north central Kansas, with cell
movement toward the north northwest and the cluster moving more
northerly. This area is forecast to move across the forecast area
through the morning hours today.
Struggle with the forecast continues to be timing and coverage of
precipitation chances. After initial energy lifts across Eastern
Kansas through early afternoon, next uncertainty will be for chances
later in the afternoon. HRRR develops a cluster of showers in south
central KS, but would anticipate a break between the systems with
subsidence behind the main wave inhibiting convective development.
Have higher chances in the morning, with lower chances middle
afternoon, followed by an increase from west to east through the
evening into the overnight hours as the main wave finally starts to
get an easterly push, from both a northern US shortwave and an upper
jet traversing the southern states. With a lull in precipitation
and possibly some better sunshine out west, this would boost
instability and chances for severe thunderstorms as late day storms
develop along the dryline to our west and along the northward
advancing warm front. Primary threat would be hail, but closer
proximity to these surface features in north central Kansas could
bring an isolated tornado risk there. General precipitation chances
continue in the overnight hours ahead of the upper low as it
continues to slowly move east. Highs for Saturday in the middle 70s
west to near 70 east, with lows in the 50s.
.LONG TERM...(Sunday through Friday)
Issued at 342 AM CDT SAT APR 18 2015
By Sunday morning the mid/upper low will be centered over SC KS and
NC OK as it progresses eastward. During this time the low will
become more of an open wave as another shortwave digs into the
northern plains and upper Midwest. These waves will bring a cold
front through the region during the day Sunday. In the morning the
better chance for showers and some thunder should be in southern KS
where the front and mid level low are more coupled in the vertical.
By 18Z the models are hinting at an increase of instability on the
order of about 1000 j/kg ahead of the front that should stretch
across eastern KS. Lapse rates are not overly impressive, and deep
layer shear could reach 30 kts. Although the better shear will be
further southeast over southern MO where the flow aloft is slightly
stronger. Therefore kept a mention of thunderstorms for east central
KS during the afternoon. A majority of the precip should clear the
area around 03Z in the evening.
A sharp pressure gradient behind the front will support northwest
surface winds around 15 to 25 mph with gusts as up to 35 mph
especially in NC KS. Cold air advection on the backside of the wave
drops temps into the lower 40s and upper 30s by Monday morning.
Winds do not completely decouple Sunday night so there is little
concern for frost. On Monday winds remain gusty with high temps
generally around 60 and partly sunny skies. Monday night will not be
the classic set up for frost with a expansive high building
southward, but the winds do decrease and temps are forecast to reach
the mid to upper 30s. Therefore could not rule out the possibility
for frost perhaps in preferred sheltered locations.
NW flow aloft develops over the region as the northern stream wave
deepens over the Great Lakes. The models are beginning to advertise
embedded shortwaves within the NW flow, which track over the plains
around mid week. This will bring small chances for either showers or
thunderstorms. Late in the week a southern wave crashes the southern
CA coast and tracks northeastward towards the center of the country.
There are some differences on how far north the instability reaches
ahead of the system, and there are additional waves in the NW flow
that could interfere with the southern stream system. Confidence in
any solution is low at this point.
&&
.AVIATION...(For the 06Z TAFs through 06Z Saturday Night)
Issued at 1134 PM CDT FRI APR 17 2015
Tricky forecast period as short term guidance has had difficulty
in determining timing and location of precip thru 12Z. However
latest models continue to show sct showers with a few embedded
TSRA impacting sites after 07Z at KMHK and 08Z at KTOP/KFOE. May
see brief MVFR conditions shortly after sunrise with the heavier
precip before it exits eastward early afternoon. Low confidence
thereafter as main system does not arrive into the area until
Sunday morning so will leave mention of VCTS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...67
LONG TERM...Sanders
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1139 PM CDT Fri Apr 17 2015
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Saturday)
Issued at 346 PM CDT FRI APR 17 2015
Upper low continues to spin over the Rockies this afternoon with an
upper level jet rounding the base of the upper low and moving over
New Mexico. Earlier showers and thunderstorms were moving out of the
northern counties at 20Z. Some clearing was occurring across the
southern and western sections of the cwa this afternoon. Latest meso
analysis shows surface based CAPE around 500 to 1000 J/kg with an
uncapped atmosphere. Expect scattered convection to develop in
southwest Kansas along the dry line. additional scattered storms may
develop in south west and south central Kansas per the latest runs
of the RAP and HRRR. Models suggest additional development this
evening across western and central Kansas moving northeast into
north central Kansas with the increase and veering of the low level
jet overnight. Models are in agreement with a lobe of energy working
it`s way northeast out of Oklahoma later tonight and Saturday
morning. May see a repeat of this morning with an area of showers
and embedded thunderstorms moving across the area. Expect a break
for a few hours in the afternoon, then chances increase again with
storms developing again in the afternoon in western and central
Kansas as upward vertical motion increases with the advance of the
upper trough into the High Plains. Dryline looks to set up across
western Kansas with the GFS the furthest east in central Kansas.
Shear and instability will be favorable for some of the storms to be
strong to severe with large hail and winds the main hazards in the
late afternoon hours mainly west of a Herington to Washington
line.
.LONG TERM...(Saturday Night through Friday)
Issued at 346 PM CDT FRI APR 17 2015
Short range models are relatively consistent in moving surface low
and main piece of upper trough through eastern KS late Saturday
night and Sunday. Ahead of this system Saturday night, increasing
thunderstorm chances are expected, with some potential for severe
weather, with the best chance in our forecast area over the western
2/3. Shear parameters are not very impressive and amount of
sunshine and associated surface heating Sat afternoon and evening is
also a little suspect so this is not a high probability thing.
As the low and front move through on Sunday, some isolated thunder
may continue in the east in the morning, but showers associated with
cold air aloft just behind the front will continue precip chances
into the afternoon hours.
After that, subsidence and cold advection behind that system brings
in dry conditions and cooler temperatures for Sunday night through
Tuesday, with lows dipping into the upper 30s many places and highs
in the low to mid 60s.
Precip chances return to parts of eastern KS on Wednesday when weak
low-level warm advection and a weak wave in northwest flow aloft
interact. Latest ECMWF and GEM would indicate that the cool air at
the surface is more entrenched in place than the GFS, thus have
gone cooler than guidance for highs on Wednesday.
Beyond Wednesday, considerable differences exist between 12Z GFS and
ECMWF in upper flow pattern and precip chances. GFS and GFSEnsemble
places us in a more favorable pattern for a couple days of precip
for Thursday and Friday, while the ECMWF is slower in bringing a
shortwave trough out of the southwest U.S., and would give us the
better chances on Friday. Have gone with a general compromise
with 25 to 40 percent POPs for those days.
&&
.AVIATION...(For the 06Z TAFs through 06Z Saturday Night)
Issued at 1134 PM CDT FRI APR 17 2015
Tricky forecast period as short term guidance has had difficulty
in determining timing and location of precip thru 12Z. However
latest models continue to show sct showers with a few embedded
TSRA impacting sites after 07Z at KMHK and 08Z at KTOP/KFOE. May
see brief MVFR conditions shortly after sunrise with the heavier
precip before it exits eastward early afternoon. Low confidence
thereafter as main system does not arrive into the area until
Sunday morning so will leave mention of VCTS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...GDP
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
421 PM CDT SAT APR 18 2015
.SYNOPSIS...
LATEST UA ANALYSIS AND WV IMAGERY SHOWS SLOW-MOVING UPR LOW OVER
ERN COLORADO...WITH MOIST SWLY FLOW CONTINUING TO STREAM OVER THE
REGION. ONE IMPULSE ASSOCIATED WITH THIS SYSTEM WAS MOVING ACRS
SRN TX INTO THE WRN GULF...WITH A SECOND IMPULSE CROSSING WRN TX.
THESE TWO SYSTEMS WERE TRIGGERING STORMS ACRS THE NW/CNTL GULF
COAST AS WELL AS ACRS WRN TX. OVER THE IMMEDIATE CWA...ACTIVITY
HAS REMAINED FAIRLY SCTD...WITH A SWATH OF LT/MODT RAIN OVER THE
COASTAL WATERS...AND SCT SHRA/TSRA ACRS CNTL/WRN LA.
&&
.DISCUSSION...
OVERNIGHT CONVECTIVE COMPLEX ALLOWED THE AIRMASS TO STABILIZE
TODAY...AND ONGOING CONVECTION OVER THE GULF HAS LIMITED INFLOW.
THIS COMBINATION HAS REDUCED THE POTENTIAL FOR HEAVY RAIN AND
WIDESPREAD ACTIVITY TODAY AND LIKELY INTO TONIGHT. LOOKING AT A
COMBINATION OF RECENT HRRR RUNS AS WELL AS RAP/NAM GUIDANCE SHOWS
A DECREASING TREND DURING THE EVENING AND OVERNIGHT. ACTIVITY
ALONG THE TX COAST IS EXPECTED TO TREK E/NE BUT GRADUALLY WEAKEN
AS IT APPROACHES OUR COASTAL WATERS ZONES. LIKEWISE...THE STORMS
ACRS WRN TX WILL MOVE EAST THIS EVENING...BUT ALSO WEAKEN AS THEY
REACH THE AREA LATER TONIGHT. QPF VALUES ARE EXPECTED TO REMAIN
BELOW AN INCH THROUGH SUNDAY...AND WITH THIS IN MIND...HAVE GONE
AHEAD AND CANCELLED THE FLASH FLOOD WATCH.
DRIER MID LVL AIR WILL BEGIN TO PUSH EAST OVER THE AREA ON
SUNDAY...HELPING TO BRING A REPREIVE FROM THE RAINY PATTERN.
HOWEVER...ENOUGH MOISTURE WILL LINGER TO ALLOW FOR AT LEAST A SLT
CHC FOR A FEW SHOWERS OR TSTMS. BY SUNDAY NIGHT...A COOL FRONT
WILL MOVE THROUGH THE REGION. ENOUGH CONVERGENCE AND LIFT ARE
EXPECTED ALONG THE FRONTAL BOUNDARY TO PRODUCE A SCT BAND OF
SHOWERS AND TSTMS AS IT CROSSES THE AREA. SPC DOES HAVE THE AREA
OUTLINED IN A SLT RISK FOR SUNDAY/SUNDAY NIGHT AS INSTABILITY
LOOKS TO INCREASE AHEAD OF THE BOUNDARY. THUS AN ISOLATED STRONG
TO SEVERE STORM CANNOT BE RULED OUT ESPECIALLY ACRS THE NRN TIER
OF COUNTIES AND PARISHES.
DRY WEATHER FINALLY RETURNS ON MONDAY AND SHOULD CONTINUE INTO
TUESDAY AS HIGH PRES BUILDS INTO THE AREA. SMALL RAIN CHCS WILL
RETURN BY MIDWEEK WITH CHCS INCREASING TOWARD THE LATTER PART OF
THE WEEK. ZONAL FLOW WILL PREVAIL THROUGH THE WEEK AND LIFT
ASSOCIATED WITH EMBEDDED DISTURBANCES WILL KEEP AT LEAST CHC POPS
OVER THE AREA THURSDAY AND FRIDAY.
&&
.MARINE...
LT TO MDT SWLY FLOW WILL CONTINUE THROUGH SUNDAY WITH SHOWERS AND
TSTMS GRADUALLY DIMINISHING. A COOL FRONT WILL CROSS THE COASTAL
WATERS LATE SUNDAY NIGHT...WITH MODT OFFSHORE FLOW DEVELOPING
FOR MONDAY. EXERCISE CAUTION CONDITIONS COULD BE POSSIBLE AT TIMES
MONDAY INTO TUESDAY. WINDS WILL GRADUALLY VEER ELY TUESDAY...THEN
SELY BY WEDNESDAY AS SFC HIGH PRES MOVES EAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 63 83 60 76 / 40 20 30 10
LCH 64 82 63 79 / 30 10 20 10
LFT 65 84 64 79 / 50 20 20 10
BPT 64 82 63 79 / 30 20 20 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE...24
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
308 PM CDT SAT APR 18 2015
.AVIATION...
TERMINALS WILL CONTINUE TO PREVAIL WITH MVFR AND IFR FLIGHT
CATEGORIES WITH WIDELY SCATTERED SHOWERS. THERE HAVE BEEN VERY FEW
THUNDERSTORMS SO THOSE WILL BE OMITTED FROM THE FORECAST AND
ADDED AS THEY INCREASE IN AREAL COVERAGE AND LOOK TO AFFECT
FORECAST SITES WILL AMEND AS NEEDED. A SURFACE LOW OVER LOWER
PARTS OF EAST TEXAS WILL LIFT TO THE NORTHEAST MOVING A WARM FRONT
NORTHEAST OVER THE EASTERN SECTIONS OF THE FOUR STATE REGION.
WINDS WILL BE VARIABLE WITH SOUTHEAST TO SOUTHWEST OVER THE
SOUTHEAST SIDE OF THE LOW PRESSURE AREA AND NORTHEAST TO NORTHERLY
AROUND THE BACK SIDE AS IT LIFTS NORTHEAST. A SERIES OF UPPER
LEVEL DISTURBANCES ROUNDING THE LARGE AND BROAD BASE OF AN UPPER
TROUGH OF LOW PRESSURE TO OUR WEST WILL CONTINUE TO PROVIDE
PERIODS OF SHOWERS DURING THE NIGHT AND ON SUNDAY AS THEY ASSIST
THE SURFACE LOW AND ITS MOVEMENT. THUNDERSTORMS WILL BE ON THE
INCREASE DURING THE AFTERNOON SUNDAY AND INTO THE EVENING. /06/
&&
.PREV DISCUSSION... /ISSUED 1118 AM CDT SAT APR 18 2015/
DISCUSSION...
MOST OF THE MODELS ARE NOT HANDLING THE ONGOING PRECIP VERY WELL
DEPICTING WAY TOO MUCH COVERAGE COMPARED TO WHAT IS ACTUALLY
OCCURRING. LACK OF PRECIP BACK TO THE SW ALSO LENDS LOW CONFIDENCETO
THE MODELS. HRRR SEEMS TO BE PERFORMING SLIGHTLY BETTER SO HAVE
TRIMMED POPS SLIGHTLY BASED ON THE MORE SCATTERED COVERAGE
EXPECTED BY THE HRRR ACROSS MAINLY THE NERN HALF OF THE CWA
THROUGH THE REMAINDER OF TODAY. STARTING TO SEE A FEW BREAKS IN
THE CLOUDS WHICH WILL HELP TEMPS TO WARM QUICKLY. INSTABILITY WILL
BE SUFFICIENT TO SUPPORT AT LEAST AN ISOLATED SEVERE THREAT IN
PLACE.
OTHERWISE...ONLY A FEW MINOR CHANGES WERE MADE TO DEWPOINT AND
WIND GRIDS BASED ON LATEST OBS. UPDATED PRODUCTS HAVE BEEN SENT.
/09/
PREV DISCUSSION... /ISSUED 652 AM CDT SAT APR 18 2015/
PREV DISCUSSION... /ISSUED 538 AM CDT SAT APR 18 2015/
DISCUSSION...
MOSTLY CLOUDY WITH MID TO UPPER 60S AND VARIABLE WINDS OVER THE
FOUR STATE AREA. THE KSHV 88D RADAR IS SHOWING MOST COVERAGE OF
SHOWER AND ISOLATED THUNDERSTORMS OVER OUR OKLAHOMA AND TEXAS
COUNTIES WITH DEPARTING COVERAGE FOR NOW OVER NORTH CENTRAL
LOUISIANA AND SOME OF THE TEXAS SOUTHERN FLANK PULLING ACROSS
TOLEDO BEND. OVERNIGHT...WE WERE CUT OFF FROM DECENT GULF
MOISTURE BY A LARGE THUNDERSTORM COMPLEX MOVING EAST ALONG I-10.
LOOKING AT THE WATER VAPOR...THE THICK BELT OF PACIFIC MOISTURE
IS STILL BACK ACROSS SOUTH TEXAS...AND LIFTING THIS WAY.
MEANWHILE...THE UPPER LOW IS SLOWLY EDGING OFF THE FOUR CORNERS
INTO CO/NB/KN NOW THANKS TO ANOTHER DEEPENING TROUGH ON THE NW
COAST. THE COLD FRONT WILL NOT ARRIVE UNTIL LATE AFTERNOON SUNDAY
AND INTO THE EVENING. SO TODAY LOOKS MORE FAVORABLE FOR WIDE
SPREAD COVERAGE WITH ONLY A MARGINAL RISK FOR SEVERE AND THEN ON
SUNDAY WE ARE SLIGHT/ENHANCED FOR SEVERE WITH THE COLD FRONT BY
MORE LIMITED WIDE SPREAD COVERAGE. OUR DEW POINTS WILL BE LOW TO
MID 60S WITH SOME MORE HEATING AHEAD OF THE FRONT ARRIVING WITH
SOME LIFT WHILE STILL UNDER THE UPPER DIVERGENT TROUGH TO OUR
WEST. SPC IS LOOKING FOR ANOTHER MCS BY LATE SUNDAY AFTERNOON AND
MOVING EAST QUICKLY INTO THE EVENING WHILE THE MODELS ARE ALL OVER
THE PLACE WITH QPF. LITTLE CHANGE WITH A COOL DOWN BACK TO NORMAL
FOR THE NEW WORK WEEK AND THEN ANOTHER FRONT MID TO LATE WEEK.
/24/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 62 83 56 74 / 50 20 20 10
MLU 63 81 58 75 / 60 40 30 10
DEQ 58 79 50 72 / 40 30 10 10
TXK 59 80 53 72 / 40 30 20 10
ELD 60 81 54 73 / 50 40 30 10
TYR 61 82 53 73 / 40 20 10 0
GGG 61 82 54 73 / 40 20 10 0
LFK 64 85 57 76 / 50 20 20 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
06
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
220 PM CDT SAT APR 18 2015
.AVIATION...
CLOUDS AND RAINS TO CONTINUE INTO THE EVENING HOURS. CEILINGS TO
VARY FROM MVFR TO IFR ALSO VSBY EXPECTED TO REMAIN ABOVE 3 SM.
&&
.PREV DISCUSSION... /ISSUED 1159 AM CDT SAT APR 18 2015/
UPDATE...
OVERNIGHT CONVECTIVE COMPLEX HAS MOVED EAST OF THE
REGION...ALLOWING THE AIRMASS TO STABILIZE BRIEFLY. ADDITIONAL
CONVECTION IS BEGINNING TO DEVELOP ACRS SRN TX IN ASSOCIATION
WITH THE NEXT IMPULSE IN THE MOIST SWLY FLOW. EXPECT SCT TO NMRS
SHRA/TSRA TO DEVELOP DURING THE AFTN AS THIS IMPULSE TRAVELS OVER
THE AREA. ADJUSTED POPS TODAY TO REFLECT RECENT HRRR AND RAP RUNS.
ALSO ADJUSTED QPF AMOUNTS...AND THIS PRODUCED MUCH LOWER QPF ACRS
SE TX. THUS...CANCELLED THE FFA ACRS OUR SE TX ZONES. KEPT FFA UP
ACRS LA AND ALTHOUGH THE RISK OF WIDESPREAD HEAVY RAIN AND
FLOODING IS LOWER...THERE IS STILL THE POSSIBILITY FOR SOME
LOCALIZED HEAVY RAIN ACRS PORTIONS OF SW LA. REMAINDER OF FCST IS
RELATIVELY UNCHANGED WITH JUST SOME MINOR EDITS TO HOURLY
TEMPS...DEWPOINTS AND WINDS. 24
PREV DISCUSSION... /ISSUED 656 AM CDT SAT APR 18 2015/
AVIATION...AEX STARTING OUT IFR ON CIGS THIS MORNING. ELSEWHERE
VFR CIGS WITH LGT RAIN. THERE COULD BE A FEW EMBEDDED TSTMS LATER
THIS MORNING. MVFR LATE TNITE AS WE SCATTER OUT ALOFT BUT REMAIN
MOIST IN THE BOUNDARY LAYER. COULD SEE SOME IFR CIGS IN SCUD ALONG
WITH SOME LIGHT FOG.
SWEENEY
PREV DISCUSSION... /ISSUED 501 AM CDT SAT APR 18 2015/
DISCUSSION...
HEAVY RAINS OVERNIGHT SO FAR HAVE BEEN CONFINED MAINLY TO
SOUTHERN JEFFERSON COUNTY IN SOUTHEAST TEXAS WITH 3-4 INCHES OF
RAIN MAINLY SOUTH OF URBAN AREAS...TO 2 TO 3 INCHES IN NORTHWEST
CAMERON PARISH OVER THE MARSHES. OTHERWISE...1 TO 2 INCH RAINS
WERE COMMON FROM OPELOUSAS...WEST TO DEQUINCY...TO ORANGE AND
VILLAGE MILLS. THE NORTHERN AREAS HAVE BEEN SPARED THIS TIME
AROUND.
THE BIG QUESTION TODAY IS THE AMOUNT OF AVAILABLE MOISTURE AND
INSTABILITY NEEDED TO CONTINUE THE FLASH FLOOD WATCH AND OF
COURSE THE RISK OF SEVERE STORM DEVELOPMENT. THE ATMOSPHERE HAS
BEEN WORKED OVER PRETTY WELL...AND THE CONVECTION OVER THE COASTAL
WATERS FROM 40NM TO WELL BEYOND 60NM HAS DIVERTED THE DEEP GULF
MOISTURE FURTHER SOUTH WAY FROM AREA. THERE IS A GOOD PLUME OF
CLOUDS BLOWING OFF GULF CONVECTION SWEEPING NORTHWARD ACROSS AREA
TODAY. ON THE OTHER HAND...SOUNDING FORECAST PROFILES SHOW
PRECIPITABLE WATER VALUES HOLDING ABOVE 1.5 INCHES OR BETTER AT
LEAST UNTIL 00Z AND THEN DROP OFF. THEREFORE...WILL NOT MENTION
SEVERE THUNDERSTORMS IN THE FORECAST AS THE RISK FROM SPC IS
SLIGHT. CLOUDS MAY HINDER INSTABILITY FOR MOST OF THE DAY ANYWAY.
HOWEVER...CANNOT RULE OUT AN ISOLATED BRIEF SEVERE MID TO LATE
AFTERNOON SOMEWHERE...BUT THAT WOULD BE ISOLATED IF ANY.
THE FLASH FLOOD WATCH COULD BE LIFTED TODAY IF IT WERE NOT FOR
THE SATURATED SOILS AND FILLED DITCHES. REALLY BELIEVE THAT THE
FIRST HALF OF THE MORNING THERE IS LITTLE OF ANY THREAT OF HEAVY
RAINS...HOWEVER IN THE AFTERNOON...COULD SEE SOME REDEVELOPMENT OF
HEAVIER RAINS FROM UPSTREAM INSTABILITY...THEREFORE...WILL LEAVE
FLASH FLOOD WATCH UP FOR NOW AS IT WOULD NOT BE PRUDENT TO MOVE IT
JUST YET.
THE UPPER LEVEL LOW SPINNING ACROSS COLORADO THIS MORNING WITH THE
SOUTHERLY TROUGH EXTENDING INTO THE SOUTH CENTRAL SOUTHERN
STATES...WILL CONTINUE TO MIGRATE EASTWARD OVER THE NEXT 48 HOURS.
AS IT DOES...DEEP MOISTURE AND ENERGY WILL SHIFT EASTWARD DURING
THIS PERIOD. THEREFORE...DO EXPECT TO SEE A BIG DROPOFF IN RAIN
CHANCES ON SUNDAY BUT KEEP LOW POPS IN AS AS FRONT SWEEPS THROUGH
THE AREA LATE SUNDAY NIGHT INTO MONDAY. THE FRONT WILL RETURN AS A
WARM FRONT BY MIDWEEK AND THEREFORE WILL GET A BUMP UP IN POPS AS
THE WARM FRONTAL BOUNDARY MOVES NORTHWARD. RAIN CHANCES ONCE AGAIN
FALL BY THE END OF THE WEEK AS THE REGION WILL REMAIN BETWEEN
SYSTEMS.
MARINE...
AM WIDESPREAD CONVECTION WILL END FROM WEST TO EAST THIS MORNING.
REDEVELOPMENT COULD BEGIN LATER THIS AFTERNOON BUT PROBABLY WILL
NOT BE QUITE AS BAD AS THE LAST COUPLE OF DAYS HAVE BEEN. ONSHORE
FLOW WILL CONTINUE WITH PERIODIC DISRUPTION DUE TO THUNDERSTORMS
AND OUTFLOWS.
06
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 64 82 61 78 / 50 20 20 10
LCH 65 82 64 80 / 40 20 20 10
LFT 66 84 65 80 / 60 30 20 10
BPT 65 82 64 80 / 40 20 20 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR LAZ027>033-
041>045-052>055-073-074.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...19
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1159 AM CDT SAT APR 18 2015
.UPDATE...
OVERNIGHT CONVECTIVE COMPLEX HAS MOVED EAST OF THE
REGION...ALLOWING THE AIRMASS TO STABILIZE BRIEFLY. ADDITIONAL
CONVECTION IS BEGINNING TO DEVELOP ACRS SRN TX IN ASSOCIATION
WITH THE NEXT IMPULSE IN THE MOIST SWLY FLOW. EXPECT SCT TO NMRS
SHRA/TSRA TO DEVELOP DURING THE AFTN AS THIS IMPULSE TRAVELS OVER
THE AREA. ADJUSTED POPS TODAY TO REFLECT RECENT HRRR AND RAP RUNS.
ALSO ADJUSTED QPF AMOUNTS...AND THIS PRODUCED MUCH LOWER QPF ACRS
SE TX. THUS...CANCELLED THE FFA ACRS OUR SE TX ZONES. KEPT FFA UP
ACRS LA AND ALTHOUGH THE RISK OF WIDESPREAD HEAVY RAIN AND
FLOODING IS LOWER...THERE IS STILL THE POSSIBILITY FOR SOME
LOCALIZED HEAVY RAIN ACRS PORTIONS OF SW LA. REMAINDER OF FCST IS
RELATIVELY UNCHANGED WITH JUST SOME MINOR EDITS TO HOURLY
TEMPS...DEWPOINTS AND WINDS. 24
&&
.PREV DISCUSSION... /ISSUED 656 AM CDT SAT APR 18 2015/
AVIATION...AEX STARTING OUT IFR ON CIGS THIS MORNING. ELSEWHERE
VFR CIGS WITH LGT RAIN. THERE COULD BE A FEW EMBEDDED TSTMS LATER
THIS MORNING. MVFR LATE TNITE AS WE SCATTER OUT ALOFT BUT REMAIN
MOIST IN THE BOUNDARY LAYER. COULD SEE SOME IFR CIGS IN SCUD ALONG
WITH SOME LIGHT FOG.
SWEENEY
PREV DISCUSSION... /ISSUED 501 AM CDT SAT APR 18 2015/
DISCUSSION...
HEAVY RAINS OVERNIGHT SO FAR HAVE BEEN CONFINED MAINLY TO
SOUTHERN JEFFERSON COUNTY IN SOUTHEAST TEXAS WITH 3-4 INCHES OF
RAIN MAINLY SOUTH OF URBAN AREAS...TO 2 TO 3 INCHES IN NORTHWEST
CAMERON PARISH OVER THE MARSHES. OTHERWISE...1 TO 2 INCH RAINS
WERE COMMON FROM OPELOUSAS...WEST TO DEQUINCY...TO ORANGE AND
VILLAGE MILLS. THE NORTHERN AREAS HAVE BEEN SPARED THIS TIME
AROUND.
THE BIG QUESTION TODAY IS THE AMOUNT OF AVAILABLE MOISTURE AND
INSTABILITY NEEDED TO CONTINUE THE FLASH FLOOD WATCH AND OF
COURSE THE RISK OF SEVERE STORM DEVELOPMENT. THE ATMOSPHERE HAS
BEEN WORKED OVER PRETTY WELL...AND THE CONVECTION OVER THE COASTAL
WATERS FROM 40NM TO WELL BEYOND 60NM HAS DIVERTED THE DEEP GULF
MOISTURE FURTHER SOUTH WAY FROM AREA. THERE IS A GOOD PLUME OF
CLOUDS BLOWING OFF GULF CONVECTION SWEEPING NORTHWARD ACROSS AREA
TODAY. ON THE OTHER HAND...SOUNDING FORECAST PROFILES SHOW
PRECIPITABLE WATER VALUES HOLDING ABOVE 1.5 INCHES OR BETTER AT
LEAST UNTIL 00Z AND THEN DROP OFF. THEREFORE...WILL NOT MENTION
SEVERE THUNDERSTORMS IN THE FORECAST AS THE RISK FROM SPC IS
SLIGHT. CLOUDS MAY HINDER INSTABILITY FOR MOST OF THE DAY ANYWAY.
HOWEVER...CANNOT RULE OUT AN ISOLATED BRIEF SEVERE MID TO LATE
AFTERNOON SOMEWHERE...BUT THAT WOULD BE ISOLATED IF ANY.
THE FLASH FLOOD WATCH COULD BE LIFTED TODAY IF IT WERE NOT FOR
THE SATURATED SOILS AND FILLED DITCHES. REALLY BELIEVE THAT THE
FIRST HALF OF THE MORNING THERE IS LITTLE OF ANY THREAT OF HEAVY
RAINS...HOWEVER IN THE AFTERNOON...COULD SEE SOME REDEVELOPMENT OF
HEAVIER RAINS FROM UPSTREAM INSTABILITY...THEREFORE...WILL LEAVE
FLASH FLOOD WATCH UP FOR NOW AS IT WOULD NOT BE PRUDENT TO MOVE IT
JUST YET.
THE UPPER LEVEL LOW SPINNING ACROSS COLORADO THIS MORNING WITH THE
SOUTHERLY TROUGH EXTENDING INTO THE SOUTH CENTRAL SOUTHERN
STATES...WILL CONTINUE TO MIGRATE EASTWARD OVER THE NEXT 48 HOURS.
AS IT DOES...DEEP MOISTURE AND ENERGY WILL SHIFT EASTWARD DURING
THIS PERIOD. THEREFORE...DO EXPECT TO SEE A BIG DROPOFF IN RAIN
CHANCES ON SUNDAY BUT KEEP LOW POPS IN AS AS FRONT SWEEPS THROUGH
THE AREA LATE SUNDAY NIGHT INTO MONDAY. THE FRONT WILL RETURN AS A
WARM FRONT BY MIDWEEK AND THEREFORE WILL GET A BUMP UP IN POPS AS
THE WARM FRONTAL BOUNDARY MOVES NORTHWARD. RAIN CHANCES ONCE AGAIN
FALL BY THE END OF THE WEEK AS THE REGION WILL REMAIN BETWEEN
SYSTEMS.
MARINE...
AM WIDESPREAD CONVECTION WILL END FROM WEST TO EAST THIS MORNING.
REDEVELOPMENT COULD BEGIN LATER THIS AFTERNOON BUT PROBABLY WILL
NOT BE QUITE AS BAD AS THE LAST COUPLE OF DAYS HAVE BEEN. ONSHORE
FLOW WILL CONTINUE WITH PERIODIC DISRUPTION DUE TO THUNDERSTORMS
AND OUTFLOWS.
06
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 77 64 82 61 / 80 50 20 20
LCH 77 65 82 64 / 80 40 20 20
LFT 78 66 84 65 / 90 60 30 20
BPT 78 65 82 64 / 70 40 20 20
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR LAZ027>033-
041>045-052>055-073-074.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS SHREVEPORT LA
1118 AM CDT SAT APR 18 2015
.DISCUSSION...
MOST OF THE MODELS ARE NOT HANDLING THE ONGOING PRECIP VERY WELL
DEPICTING WAY TOO MUCH COVERAGE COMPARED TO WHAT IS ACTUALLY
OCCURRING. LACK OF PRECIP BACK TO THE SW ALSO LENDS LOW CONFIDENCETO
THE MODELS. HRRR SEEMS TO BE PERFORMING SLIGHTLY BETTER SO HAVE
TRIMMED POPS SLIGHTLY BASED ON THE MORE SCATTERED COVERAGE
EXPECTED BY THE HRRR ACROSS MAINLY THE NERN HALF OF THE CWA
THROUGH THE REMAINDER OF TODAY. STARTING TO SEE A FEW BREAKS IN
THE CLOUDS WHICH WILL HELP TEMPS TO WARM QUICKLY. INSTABILITY WILL
BE SUFFICIENT TO SUPPORT AT LEAST AN ISOLATED SEVERE THREAT IN
PLACE.
OTHERWISE...ONLY A FEW MINOR CHANGES WERE MADE TO DEWPOINT AND
WIND GRIDS BASED ON LATEST OBS. UPDATED PRODUCTS HAVE BEEN SENT.
/09/
&&
.PREV DISCUSSION... /ISSUED 652 AM CDT SAT APR 18 2015/
AVIATION...
SEEING QUITE A SPREAD IN CIGS THIS MORNING...WITH IFR CIGS OVER
NCNTRL LA AS WELL AS PORTIONS OF DEEP E TX...WITH A MIX OF
MVFR/VFR CIGS ELSEWHERE ACROSS THE REGION. A WEAK SFC WAVE HAS
DEVELOPED ALONG A STATIONARY FRONT OVER EXTREME ERN TX...AND
SHOULD SHIFT ENE INTO NRN LA THIS MORNING...RESULTING IN THE
DEVELOPMENT OF LOW MVFR/IFR CIGS BY MIDMORNING OVER NW LA/SW AR.
SCT -SHRA AND ISOLATED -TSRA CONTINUE TO DEVELOP OVER PORTIONS OF
E TX/SE OK/ADJACENT SW AR THIS MORNING...WITH THIS TREND EXPECTED
TO CONTINUE/SPREAD FARTHER E ACROSS NCNTRL LA/SCNTRL AR THIS
MORNING BEFORE GRADUALLY DIMINISHING FROM SW TO NE THIS AFTERNOON.
HAVE TEMPOED MENTION OF SHRA INTO THE N LA/SW AR TERMINALS THIS
MORNING...BUT LOW CONFIDENCE PRECLUDES MENTION FOR THE AFTERNOON.
WHILE CIGS WILL BE SLOW TO IMPROVE TODAY OVER N LA/SW AR NEAR THE
SFC FRONTAL WAVE...SHOULD SEE CIGS IMPROVING TO VFR BY MID-
AFTERNOON ACROSS E TX...SCATTERING OUT BY 00Z SUNDAY. COULD ALSO
SEE THE RETURN OF IFR/MVFR CIGS LATE IN THE TAF PERIOD ACROSS E
TX/N LA JUST PRIOR TO DAYBREAK SUNDAY...WITH THESE CIGS EXPECTED
TO SPREAD FARTHER NNE SHORTLY THERE AFTERWARDS. VRB WINDS 6KTS OR
LESS TODAY WILL BECOME LT/VRB AFTER 00Z. /15/
PREV DISCUSSION... /ISSUED 538 AM CDT SAT APR 18 2015/
DISCUSSION...
MOSTLY CLOUDY WITH MID TO UPPER 60S AND VARIABLE WINDS OVER THE
FOUR STATE AREA. THE KSHV 88D RADAR IS SHOWING MOST COVERAGE OF
SHOWER AND ISOLATED THUNDERSTORMS OVER OUR OKLAHOMA AND TEXAS
COUNTIES WITH DEPARTING COVERAGE FOR NOW OVER NORTH CENTRAL
LOUISIANA AND SOME OF THE TEXAS SOUTHERN FLANK PULLING ACROSS
TOLEDO BEND. OVERNIGHT...WE WERE CUT OFF FROM DECENT GULF
MOISTURE BY A LARGE THUNDERSTORM COMPLEX MOVING EAST ALONG I-10.
LOOKING AT THE WATER VAPOR...THE THICK BELT OF PACIFIC MOISTURE
IS STILL BACK ACROSS SOUTH TEXAS...AND LIFTING THIS WAY.
MEANWHILE...THE UPPER LOW IS SLOWLY EDGING OFF THE FOUR CORNERS
INTO CO/NB/KN NOW THANKS TO ANOTHER DEEPENING TROUGH ON THE NW
COAST. THE COLD FRONT WILL NOT ARRIVE UNTIL LATE AFTERNOON SUNDAY
AND INTO THE EVENING. SO TODAY LOOKS MORE FAVORABLE FOR WIDE
SPREAD COVERAGE WITH ONLY A MARGINAL RISK FOR SEVERE AND THEN ON
SUNDAY WE ARE SLIGHT/ENHANCED FOR SEVERE WITH THE COLD FRONT BY
MORE LIMITED WIDE SPREAD COVERAGE. OUR DEW POINTS WILL BE LOW TO
MID 60S WITH SOME MORE HEATING AHEAD OF THE FRONT ARRIVING WITH
SOME LIFT WHILE STILL UNDER THE UPPER DIVERGENT TROUGH TO OUR
WEST. SPC IS LOOKING FOR ANOTHER MCS BY LATE SUNDAY AFTERNOON AND
MOVING EAST QUICKLY INTO THE EVENING WHILE THE MODELS ARE ALL OVER
THE PLACE WITH QPF. LITTLE CHANGE WITH A COOL DOWN BACK TO NORMAL
FOR THE NEW WORK WEEK AND THEN ANOTHER FRONT MID TO LATE WEEK.
/24/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 77 62 83 56 / 50 50 20 20
MLU 76 63 81 58 / 60 60 40 30
DEQ 76 58 79 50 / 40 40 30 10
TXK 75 59 80 53 / 50 40 30 20
ELD 75 60 81 54 / 50 50 40 30
TYR 78 61 82 53 / 20 40 20 10
GGG 77 61 82 54 / 30 40 20 10
LFK 78 64 85 57 / 30 50 20 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
09
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1215 PM EDT SAT APR 18 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 328 AM EDT SAT APR 18 2015
ANOTHER SUNNY DAY IS EXPECTED TODAY WITH HIGHS AROUND 70. LOW
PRESSURE WILL MOVE NORTH FROM THE GULF AREA SUNDAY BRINGING QUITE A
BIT OF RAIN WITH IT. AFTER THE LOW MOVES EAST...COLDER AIR WILL MOVE
OVER LOWER MICHIGAN AND REMAIN IN PLACE NEXT WEEK. HIGHS WILL ONLY
REACH THE MID 40S TO MID 50S NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1055 AM EDT SAT APR 18 2015
I INCREASED THE HIGH TEMPERATURE AROUND 5 DEGREES FOR THIS
AFTERNOON BASED ON MORNING SOUNDING DATA. THE RAP MODEL SEEMS TO
BE DOING A BETTER JOB OF SHOWING CURRENT TEMPERATURES...DEW POINTS
AND WINDS SO I USED THAT TO INCREASE THE WIND SPEED...TEMPERATURES
AND LOWER THE DEW POINTS. THAT ALL BEING SO... WE COULD SEE HIGHS
IN THE MID TO UPPER 70S OVER THE WESTERN SECTIONS OF THE CWA THIS
AFTERNOON. WE WILL BE GETTING CLOSE TO RED FLAG CONDITIONS IF THIS
HAPPENS. FOR NOW I WILL LET OUR HWO AND POST OF FACEBOOK COVER
THIS ISSUE.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 328 AM EDT SAT APR 18 2015
FORECAST CONCERNS DEAL WITH THE LOW APPROACHING SUNDAY. AFTER
ANOTHER SUNNY AND MILD DAY TODAY CLOUDS WILL INCREASE TONIGHT AS A
PHASED NORTHERN/SOUTHERN STREAM LOW APPROACHES FROM THE SOUTH.
STRONG 60KT LLJ WILL DRAW UP ABUNDANT MOISTURE INTO THE SYSTEM.
STRONG ISENTROPIC LIFT LATE SUNDAY MORNING WILL LEAD TO RAPID RAIN
DEVELOPMENT FROM SOUTH TO NORTH. LOOK FOR THE WIND TO INCREASE AS
WELL...AT LEAST UNTIL THE LOW MOVES OVERHEAD SUNDAY EVENING. SHORT
RANGE MODELS HAVE BEEN CONSISTENT MOVING THE LOW DIRECTLY OVER THE
CWA SO CONFIDENCE IS PRETTY HIGH WE/LL SEE RAIN. QPF AROUND 3/4 INCH
LOOKS POSSIBLE AS MIXING RATIOS CLIMB TO 8G/KG BY LATE SUNDAY
AFTERNOON. THERE STILL ISN/T A STRONG SIGNAL FOR THUNDER SO WE KEPT
IT OUT OF THE GRIDS. HOWEVER GIVEN A SLIGHT DECREASE IN STABILITY
NOTED WE CAN/T RULE IT OUT EITHER.
MONDAY WILL BE MUCH COOLER AS THE LOW MOVES EAST AND WEST WINDS
DEVELOP. HIGHS IN THE MID 50S ARE EXPECTED. THE UPPER LOW WILL MOVE
OVER THE CWA MONDAY SO WE/LL CONTINUE TO SEE SCATTERED SHOWERS.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 328 AM EDT SAT APR 18 2015
MOST OF NEXT WEEK WILL BE COLDER THAN NORMAL WITH SCATTERED RAIN OR
MIXED RAIN AND SNOW SHOWERS AS AN UPPER LOW BECOMES PARKED OVER THE
NORTHERN GREAT LAKES REGION. DEEP CYCLONIC FLOW AND COLD ADVECTION
WILL LEAD TO CONSIDERABLE CLOUDINESS WITH HIGHS ONLY IN THE 40S AND
FREQUENTLY BREEZY CONDITIONS.
THE MAIN RISK FOR SNOW SHOWERS WILL BE AT NIGHT AND DURING THE EARLY
MORNING WHEN THE BOUNDARY LAYER IS COOLEST... ESPECIALLY FOR HIGHER
ELEVATIONS NEAR AND NORTH OF ROUTE 10 WHERE SOME LIGHT ACCUMULATIONS
EVEN APPEAR POSSIBLE.
GFS/ECMWF DO NOT LOOK PARTICULARLY BULLISH WITH QPF AT ANY TIME NEXT
WEEK ALTHOUGH SPOKES OF VORTICITY ROTATING AROUND THE UPPER LOW
MAY LEAD TO OCCASIONAL BOUTS OF INCREASED COVERAGE OF HEAVIER
SHOWERS.
THINGS APPEAR TO DRY OUR THURSDAY NIGHT AND FRIDAY WHEN THE UPR LOW
MOVES EAST AND SFC RIDGING ARRIVES FROM THE WEST. BY FRIDAY HIGHS
COULD BE BACK UP INTO THE 50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY)
ISSUED AT 1215 PM EDT SAT APR 18 2015
VFR CONDITIONS WILL CONTINUE THROUGH 18Z SUNDAY. ENE WINDS WILL GUST
TO AROUND 20 KTS AT TIMES THIS AFTERNOON AND BECOME EASTERLY AND
GUST TO 20 TO 25 KTS SUNDAY MORNING AND AFTERNOON. SHOWERS WILL
GRADUALLY MOVE IN FROM SOUTH TO NORTH AT ALL THE TERMINALS BETWEEN
18Z AND 21Z SUNDAY AFTERNOON WHEN CONDITIONS WILL DETERIORATE TO
PRIMARILY MVFR WITH POCKETS OF IFR POSSIBLE IN HEAVIER SHOWERS.
&&
.MARINE...
ISSUED AT 328 AM EDT SAT APR 18 2015
A COLD FRONT WILL MOVE THROUGH EARLY TODAY AND TURN THE WINDS TO THE
NORTHEAST. THE OFFSHORE FLOW WILL CONTINUE TONIGHT AND STRENGTHEN. A
SCA MAY BE NEEDED TONIGHT.
&&
.HYDROLOGY...
ISSUED AT 1126 AM EDT SAT APR 18 2015
A GOOD SOAKING RAINFALL IS STILL ON TRACK TO AFFECT THE ENTIRE AREA
BEGINNING SUNDAY. THE BULK OF THE MOISTURE WILL LIKELY FALL
BETWEEN SUNDAY AFTERNOON INTO MONDAY MORNING WITH SOME GUIDANCE
HINTING AT OVER AN INCH IN SPOTS. ADDITIONAL CHANCES FOR RAIN WILL
SPAN THROUGH THE MIDDLE OF THE WEEK BUT ARE NOT EXPECTED TO BE
QUITE AS ABUNDANT WITH MOISTURE.
RIVERS WILL MAINLY RESPOND IN THE MANNER OF MINOR RISES. THIS SHOULD
MOSTLY CONSIST OF WITHIN BANK RISES. I HAVE A LITTLE MORE CONFIDENCE
IN THINKING MAPLE RAPIDS COULD FLIRT WITH ADVISORY CRITERIA ONCE
AGAIN.
THIS IS PENDING THE AMOUNT OF RAINFALL RECEIVED THROUGH EARLY MONDAY.
OTHERWISE...WE ARE LOOKING PRETTY GOOD WITH THIS NOT BEING A
CONVECTIVE
MODE OF PRECIPITATION...NO REAL SURPRISES AT THIS POINT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...LAURENS
HYDROLOGY...JAM
MARINE...04
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1126 AM EDT SAT APR 18 2015
LATEST UPDATE...
HYDRO
.SYNOPSIS...
ISSUED AT 328 AM EDT SAT APR 18 2015
ANOTHER SUNNY DAY IS EXPECTED TODAY WITH HIGHS AROUND 70. LOW
PRESSURE WILL MOVE NORTH FROM THE GULF AREA SUNDAY BRINGING QUITE A
BIT OF RAIN WITH IT. AFTER THE LOW MOVES EAST...COLDER AIR WILL MOVE
OVER LOWER MICHIGAN AND REMAIN IN PLACE NEXT WEEK. HIGHS WILL ONLY
REACH THE MID 40S TO MID 50S NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1055 AM EDT SAT APR 18 2015
I INCREASED THE HIGH TEMPERATURE AROUND 5 DEGREES FOR THIS
AFTERNOON BASED ON MORNING SOUNDING DATA. THE RAP MODEL SEEMS TO
BE DOING A BETTER JOB OF SHOWING CURRENT TEMPERATURES...DEW POINTS
AND WINDS SO I USED THAT TO INCREASE THE WIND SPEED...TEMPERATURES
AND LOWER THE DEW POINTS. THAT ALL BEING SO... WE COULD SEE HIGHS
IN THE MID TO UPPER 70S OVER THE WESTERN SECTIONS OF THE CWA THIS
AFTERNOON. WE WILL BE GETTING CLOSE TO RED FLAG CONDITIONS IF THIS
HAPPENS. FOR NOW I WILL LET OUR HWO AND POST OF FACEBOOK COVER
THIS ISSUE.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 328 AM EDT SAT APR 18 2015
FORECAST CONCERNS DEAL WITH THE LOW APPROACHING SUNDAY. AFTER
ANOTHER SUNNY AND MILD DAY TODAY CLOUDS WILL INCREASE TONIGHT AS A
PHASED NORTHERN/SOUTHERN STREAM LOW APPROACHES FROM THE SOUTH.
STRONG 60KT LLJ WILL DRAW UP ABUNDANT MOISTURE INTO THE SYSTEM.
STRONG ISENTROPIC LIFT LATE SUNDAY MORNING WILL LEAD TO RAPID RAIN
DEVELOPMENT FROM SOUTH TO NORTH. LOOK FOR THE WIND TO INCREASE AS
WELL...AT LEAST UNTIL THE LOW MOVES OVERHEAD SUNDAY EVENING. SHORT
RANGE MODELS HAVE BEEN CONSISTENT MOVING THE LOW DIRECTLY OVER THE
CWA SO CONFIDENCE IS PRETTY HIGH WE/LL SEE RAIN. QPF AROUND 3/4 INCH
LOOKS POSSIBLE AS MIXING RATIOS CLIMB TO 8G/KG BY LATE SUNDAY
AFTERNOON. THERE STILL ISN/T A STRONG SIGNAL FOR THUNDER SO WE KEPT
IT OUT OF THE GRIDS. HOWEVER GIVEN A SLIGHT DECREASE IN STABILITY
NOTED WE CAN/T RULE IT OUT EITHER.
MONDAY WILL BE MUCH COOLER AS THE LOW MOVES EAST AND WEST WINDS
DEVELOP. HIGHS IN THE MID 50S ARE EXPECTED. THE UPPER LOW WILL MOVE
OVER THE CWA MONDAY SO WE/LL CONTINUE TO SEE SCATTERED SHOWERS.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 328 AM EDT SAT APR 18 2015
MOST OF NEXT WEEK WILL BE COLDER THAN NORMAL WITH SCATTERED RAIN OR
MIXED RAIN AND SNOW SHOWERS AS AN UPPER LOW BECOMES PARKED OVER THE
NORTHERN GREAT LAKES REGION. DEEP CYCLONIC FLOW AND COLD ADVECTION
WILL LEAD TO CONSIDERABLE CLOUDINESS WITH HIGHS ONLY IN THE 40S AND
FREQUENTLY BREEZY CONDITIONS.
THE MAIN RISK FOR SNOW SHOWERS WILL BE AT NIGHT AND DURING THE EARLY
MORNING WHEN THE BOUNDARY LAYER IS COOLEST... ESPECIALLY FOR HIGHER
ELEVATIONS NEAR AND NORTH OF ROUTE 10 WHERE SOME LIGHT ACCUMULATIONS
EVEN APPEAR POSSIBLE.
GFS/ECMWF DO NOT LOOK PARTICULARLY BULLISH WITH QPF AT ANY TIME NEXT
WEEK ALTHOUGH SPOKES OF VORTICITY ROTATING AROUND THE UPPER LOW
MAY LEAD TO OCCASIONAL BOUTS OF INCREASED COVERAGE OF HEAVIER
SHOWERS.
THINGS APPEAR TO DRY OUR THURSDAY NIGHT AND FRIDAY WHEN THE UPR LOW
MOVES EAST AND SFC RIDGING ARRIVES FROM THE WEST. BY FRIDAY HIGHS
COULD BE BACK UP INTO THE 50S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 745 AM EDT SAT APR 18 2015
SFC WINDS WILL INCREASE OUT OF THE NORTHEAST LATER THIS MORNING...
WITH SPEEDS OF 10 TO 20 KTS BECOMING COMMON BY AFTERNOON. THE
WINDS INCREASE FURTHER AFTER 20Z... WITH SOME GUSTS TO 30 KTS
POSSIBLE LATE TODAY INTO TONIGHT. HIGH CONFIDENCE IN VFR
CIGS/VSBYS CONTINUING TODAY AND TONIGHT.
&&
.MARINE...
ISSUED AT 328 AM EDT SAT APR 18 2015
A COLD FRONT WILL MOVE THROUGH EARLY TODAY AND TURN THE WINDS TO THE
NORTHEAST. THE OFFSHORE FLOW WILL CONTINUE TONIGHT AND STRENGTHEN. A
SCA MAY BE NEEDED TONIGHT.
&&
.HYDROLOGY...
ISSUED AT 1126 AM EDT SAT APR 18 2015
A GOOD SOAKING RAINFALL IS STILL ON TRACK TO AFFECT THE ENTIRE AREA
BEGINNING SUNDAY. THE BULK OF THE MOISTURE WILL LIKELY FALL
BETWEEN SUNDAY AFTERNOON INTO MONDAY MORNING WITH SOME GUIDANCE
HINTING AT OVER AN INCH IN SPOTS. ADDITIONAL CHANCES FOR RAIN WILL
SPAN THROUGH THE MIDDLE OF THE WEEK BUT ARE NOT EXPECTED TO BE
QUITE AS ABUNDANT WITH MOISTURE.
RIVERS WILL MAINLY RESPOND IN THE MANNER OF MINOR RISES. THIS SHOULD
MOSTLY CONSIST OF WITHIN BANK RISES. I HAVE A LITTLE MORE CONFIDENCE
IN THINKING MAPLE RAPIDS COULD FLIRT WITH ADVISORY CRITERIA ONCE AGAIN.
THIS IS PENDING THE AMOUNT OF RAINFALL RECEIVED THROUGH EARLY MONDAY.
OTHERWISE...WE ARE LOOKING PRETTY GOOD WITH THIS NOT BEING A CONVECTIVE
MODE OF PRECIPITATION...NO REAL SURPRISES AT THIS POINT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JAM
MARINE...04
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1056 AM EDT SAT APR 18 2015
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 328 AM EDT SAT APR 18 2015
ANOTHER SUNNY DAY IS EXPECTED TODAY WITH HIGHS AROUND 70. LOW
PRESSURE WILL MOVE NORTH FROM THE GULF AREA SUNDAY BRINGING QUITE A
BIT OF RAIN WITH IT. AFTER THE LOW MOVES EAST...COLDER AIR WILL MOVE
OVER LOWER MICHIGAN AND REMAIN IN PLACE NEXT WEEK. HIGHS WILL ONLY
REACH THE MID 40S TO MID 50S NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1055 AM EDT SAT APR 18 2015
I INCREASED THE HIGH TEMPERATURE AROUND 5 DEGREES FOR THIS
AFTERNOON BASED ON MORNING SOUNDING DATA. THE RAP MODEL SEEMS TO
BE DOING A BETTER JOB OF SHOWING CURRENT TEMPERATURES...DEW POINTS
AND WINDS SO I USED THAT TO INCREASE THE WIND SPEED...TEMPERATURES
AND LOWER THE DEW POINTS. THAT ALL BEING SO... WE COULD SEE HIGHS
IN THE MID TO UPPER 70S OVER THE WESTERN SECTIONS OF THE CWA THIS
AFTERNOON. WE WILL BE GETTING CLOSE TO RED FLAG CONDITIONS IF THIS
HAPPENS. FOR NOW I WILL LET OUR HWO AND POST OF FACEBOOK COVER
THIS ISSUE.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 328 AM EDT SAT APR 18 2015
FORECAST CONCERNS DEAL WITH THE LOW APPROACHING SUNDAY. AFTER
ANOTHER SUNNY AND MILD DAY TODAY CLOUDS WILL INCREASE TONIGHT AS A
PHASED NORTHERN/SOUTHERN STREAM LOW APPROACHES FROM THE SOUTH.
STRONG 60KT LLJ WILL DRAW UP ABUNDANT MOISTURE INTO THE SYSTEM.
STRONG ISENTROPIC LIFT LATE SUNDAY MORNING WILL LEAD TO RAPID RAIN
DEVELOPMENT FROM SOUTH TO NORTH. LOOK FOR THE WIND TO INCREASE AS
WELL...AT LEAST UNTIL THE LOW MOVES OVERHEAD SUNDAY EVENING. SHORT
RANGE MODELS HAVE BEEN CONSISTENT MOVING THE LOW DIRECTLY OVER THE
CWA SO CONFIDENCE IS PRETTY HIGH WE/LL SEE RAIN. QPF AROUND 3/4 INCH
LOOKS POSSIBLE AS MIXING RATIOS CLIMB TO 8G/KG BY LATE SUNDAY
AFTERNOON. THERE STILL ISN/T A STRONG SIGNAL FOR THUNDER SO WE KEPT
IT OUT OF THE GRIDS. HOWEVER GIVEN A SLIGHT DECREASE IN STABILITY
NOTED WE CAN/T RULE IT OUT EITHER.
MONDAY WILL BE MUCH COOLER AS THE LOW MOVES EAST AND WEST WINDS
DEVELOP. HIGHS IN THE MID 50S ARE EXPECTED. THE UPPER LOW WILL MOVE
OVER THE CWA MONDAY SO WE/LL CONTINUE TO SEE SCATTERED SHOWERS.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 328 AM EDT SAT APR 18 2015
MOST OF NEXT WEEK WILL BE COLDER THAN NORMAL WITH SCATTERED RAIN OR
MIXED RAIN AND SNOW SHOWERS AS AN UPPER LOW BECOMES PARKED OVER THE
NORTHERN GREAT LAKES REGION. DEEP CYCLONIC FLOW AND COLD ADVECTION
WILL LEAD TO CONSIDERABLE CLOUDINESS WITH HIGHS ONLY IN THE 40S AND
FREQUENTLY BREEZY CONDITIONS.
THE MAIN RISK FOR SNOW SHOWERS WILL BE AT NIGHT AND DURING THE EARLY
MORNING WHEN THE BOUNDARY LAYER IS COOLEST... ESPECIALLY FOR HIGHER
ELEVATIONS NEAR AND NORTH OF ROUTE 10 WHERE SOME LIGHT ACCUMULATIONS
EVEN APPEAR POSSIBLE.
GFS/ECMWF DO NOT LOOK PARTICULARLY BULLISH WITH QPF AT ANY TIME NEXT
WEEK ALTHOUGH SPOKES OF VORTICITY ROTATING AROUND THE UPPER LOW
MAY LEAD TO OCCASIONAL BOUTS OF INCREASED COVERAGE OF HEAVIER
SHOWERS.
THINGS APPEAR TO DRY OUR THURSDAY NIGHT AND FRIDAY WHEN THE UPR LOW
MOVES EAST AND SFC RIDGING ARRIVES FROM THE WEST. BY FRIDAY HIGHS
COULD BE BACK UP INTO THE 50S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 745 AM EDT SAT APR 18 2015
SFC WINDS WILL INCREASE OUT OF THE NORTHEAST LATER THIS MORNING...
WITH SPEEDS OF 10 TO 20 KTS BECOMING COMMON BY AFTERNOON. THE
WINDS INCREASE FURTHER AFTER 20Z... WITH SOME GUSTS TO 30 KTS
POSSIBLE LATE TODAY INTO TONIGHT. HIGH CONFIDENCE IN VFR
CIGS/VSBYS CONTINUING TODAY AND TONIGHT.
&&
.MARINE...
ISSUED AT 328 AM EDT SAT APR 18 2015
A COLD FRONT WILL MOVE THROUGH EARLY TODAY AND TURN THE WINDS TO THE
NORTHEAST. THE OFFSHORE FLOW WILL CONTINUE TONIGHT AND STRENGTHEN. A
SCA MAY BE NEEDED TONIGHT.
&&
.HYDROLOGY...
ISSUED AT 1119 AM EDT FRI APR 17 2015
NO RIVER FLOOD ADVISORIES ARE IN EFFECT AT THIS TIME. IMPROVEMENT
IS EXPECTED TO CONTINUE AS DRY CONDITIONS WILL HOLD STRONG TODAY
THROUGH SATURDAY.
THOUGHTS ON THE NEXT ROUND OF MOISTURE ARE CONSISTENT WITH THE
PREVIOUS HYDRO UPDATE (4/16). A DECENT SOAKING RAIN IS EXPECTED TO
MOVE IN SUNDAY WITH OFF/ON WET WEATHER POSSIBLE THROUGH THE
MIDDLE OF NEXT WEEK. MUCH OF THE MOISTURE SHOULD FALL LATE IN THE
WEEKEND AND EARLY INTO THE NEW WORK WEEK. THIS COULD RESULT IN MINOR
UPTICKS FOR RIVERS. THE LACK OF CONVECTIVE ACTIVITY...OR HIGH END
HEAVIER RAINFALL...KEEPS ME SOMEWHAT CONSERVATIVE ON ANY RISES
THAT WOULD OTHERWISE BE MORE CONCERNING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JAM
MARINE...04
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1200 PM CDT SAT APR 18 2015
.UPDATE... IN THE PAST HOUR OR TWO IT IS BECOMING INCREASINGLY
APPARENT THAT DEEP CONVECTION STRETCHING FROM THE NORTH CENTRAL GULF
TO THE WESTERN GULF IS REALLY GOING TO HAMPER VIGOROUS THUNDERSTORM
DEVELOPMENT OVER THE LOWER MS VALLEY LATE TODAY INTO THIS EVENING.
STILL NOT CONVINCED THAT MOISTURE...LIFT AND INSTABILITY INGREDIENTS
WILL NOT BE ENOUGH AT LEAST ALONG AND SOUTHEAST OF THE NATCHEZ TRACE
CORRIDOR TO GET A FEW SEVERE STORMS GOING EVENTUALLY WITH A HEAVY
RAIN THREAT PERSISTING AS WELL. FOR THAT REASON WE HAVE DOWNPLAYED
SEVERE POTENTIAL IN ALL AREAS THROUGH THE REST OF TODAY AND INTO
TONIGHT IN ALL AREAS (ALTHOUGH KEEPING SOME RISK GOING IN THE
SOUTHEAST HALF OF THE CWA). WE WILL WATCH TRENDS CLOSELY TO ADJUST
WITH THE AFTERNOON UPDATE. /BB/
&&
.PREV DISCUSSION... /ISSUED 1025 AM CDT SAT APR 18 2015/
UPDATE... THINGS THIS MORNING ARE EVOLVING GENERALLY AS
ANTICIPATED...ALTHOUGH QUESTION MARKS GOING INTO LATE TODAY STILL
PERSIST IN SOME MEASURE OWING TO THUNDERSTORMS ANCHORED TO THE SE LA
COAST. THESE STORMS WERE PREVIOUSLY SPREADING A LIGHT RAIN SHIELD
INTO MY SOUTHERN ZONES...BUT THE NORTHWARD EXTENT OF THIS PRECIP HAS
SHRUNK IN THE LAST FEW HOURS. ALSO...VIGOROUS STORMS JUST SOUTH OF
THE COAST HAVE BEEN GRADUALLY LOSING COVERAGE SINCE DAYBREAK AND
THEY SHOULD EBB QUICKLY INTO MIDDAY AS UPPER JET PULLING BACK TO THE
WEST REMOVES MUCH OF THE UPPER LEVEL SUPPORT. HOWEVER...IF SAID
EVOLUTION DOES NOT COME TO PASS WITH HASTE THEN MOISTURE TRANSPORT
BLOCKING AND CLOUD COVER INTO SOME OF MY SOUTHERN ZONES WILL HINDER
POTENTIAL FOR VIGOROUS INLAND THUNDERSTORM FORMATION AS WE GO INTO
THIS AFTERNOON.
BUT ASSUMING THE LATTER CAVEAT IS NOT AN ISSUE...LATEST HRRR AND
DOWNSCALED NAM RUNS POINT TO WORRISOME STORMS MOVING INTO MY
SOUTHERN ZONES (ESPECIALLY SOUTH CENTRAL AND SE MS) ZONES FROM MID
AFTERNOON THROUGH MID EVENING. ATMOSPHERIC LAPSE RATES WILL MAINLY
BE AT OR LESS THAN 6 C/KM IN THE H700-H500 LAYER BUT MLCAPE PEAKING
OVER 1000 J/KG SHOULD BE SUFFICIENT GIVEN EXPECTED LOW LEVEL AND
DEEP LAYER SHEAR TO PRODUCE ORGANIZED STORMS. ONCE AGAIN...A FEW
TORNADOES CANNOT BE RULED OUT.
THERE IS NOT ENOUGH EVIDENCE YET TO GO CHANGING THE PREVIOUS
FORECAST AND SEVERE WEATHER EXPECTATIONS MUCH. HOWEVER...WE WILL BE
WATCHING TRENDS CLOSELY OVER THE NEXT FEW HOURS AND WILL SEE IF VERY
RECENT HRRR HINTS THAT SEVERE RISK WILL BE STRONGLY FOCUSING
SOUTHEAST OF THE NATCHEZ TRACE APPEAR SOLID. IF THAT IS THE CASE WE
WILL UPDATE ACCORDINGLY...BUT EVEN IF WE DO FOCUS THE SEVERE RISK
EVEN MORE CONSIDERABLY IN SOUTHERN ZONES THE RISK OF LOCALIZED
FLOODING PROBLEMS STILL LOOKS TO EXTEND ACROSS A MUCH LARGER PORTION
OF THE FORECAST AREA. /BB/
AVIATION...IFR CATEGORY STRATUS PREVAILS ACROSS THE TAF SITES THIS
MORNING WITH SHOWERS MOVING ACROSS HBG. EXPECT THESE CONDITIONS TO
PERSIST UNTIL LATE MORNING/EARLY AFTERNOON BEFORE FINALLY MIXING
OUT. SHRA WILL MOSTLY CONFINED TO LOCATIONS SOUTH OF THE HEZ-HBG
CORRIDOR THIS MORNING AS A CONVECTIVE COMPLEX SLIDES EASTWARD ALONG
THE COAST...BUT A NEW ROUND OF SHRA/TSRA IS EXPECTED BY MID/LATE
AFTERNOON LASTING INTO THE EVENING WITH AN APPROACHING DISTURBANCE.
THERE MAY BE A WINDOW OF OPPORTUNITY FOR BETTER FLYING CONDITIONS
DURING THE EARLY AFTERNOON...FOLLOWED BY POOR FLYING CONDITIONS
PERSISTING FROM MID/LATE AFTERNOON THROUGH THE EVENING.
/EC/15/
PREV DISCUSSION... /ISSUED 454 AM CDT SAT APR 18 2015/
SHORT TERM...TODAY THROUGH TONIGHT...AN ACTIVE WEATHER WEEKEND IS
IN STORE AS TWO ROUNDS OF SEVERE WEATHER ARE EXPECTED TO IMPACT THE
ARKLAMISS. THE FIRST ROUND WILL BE INITIATED BY INCREASINGLY
FAVORABLE CYCLONIC AND SHEARED FLOW DEVELOPING OVER THE LOWER MS
VALLEY REGION LATER THIS AFTERNOON AND EVENING. THE CONVECTIVE SYSTEM
CURRENTLY MOVING EAST ALONG THE THE LA COAST WILL DELAY TIMING OF THE
MORE SIGNIFICANT THUNDERSTORM ACTIVITY UNTIL MID/LATE AFTERNOON...BUT
VERY MOIST AND UNSTABLE AIR WITH PRECIPITABLE WATER VALUES > 1.75
INCHES AND ML CAPE NEAR 1000 J/KG SHOULD BE AVAILABLE FOR VIGOROUS
CONVECTIVE DEVELOPMENT AT THAT TIME. WITH DEEP LAYER AND LOW LEVEL
SHEAR ON THE INCREASE...STILL EXPECT ORGANIZED STORMS TO DEVELOP WITH
THE MOST FAVORABLE SET-UP FOR SEVERE WEATHER AND HEAVY RAINFALL
ALONG/SOUTH OF THE I-20 CORRIDOR...BUT WILL SAY THAT CONFIDENCE IS A
LITTLE SHAKIER NOW ON THIS SCENARIO BASED ON RECENT HIGH RES GUIDANCE
TRENDS. IF THE NEXT ROUND OF CONVECTIVE DOES NOT MATERIALIZE AS
ANTICIPATED DUE TO THE MORNING CONVECTION...OR IF IT DEVELOPS FARTHER
EAST...THEN IT IS POSSIBLE THAT MORE ROBUST CONVECTION WOULD IMPACT
NORTHERN PORTIONS OF THE ARKLAMISS AND THIS COULD ALLOW THE SEVERE
WEATHER/HEAVY RAINFALL THREAT TO SHIFT FARTHER NORTH AS WELL. STAY
TUNED FOR UPDATES TO THIS FORECAST LATER THIS MORNING AS CONVECTIVE
EVOLUTION HOPEFULLY BECOMES A LITTLE MORE CLEAR. /EC/
SUNDAY THROUGH SUNDAY NIGHT...MODELS FOR SUNDAY CONTINUE TO SUPPORT
THE RISK FOR SEVERE STORMS ALONG WITH SOME POTENTIAL FOR A HIGHER END
EVENT. WHAT IS STARTING TO BECOME MORE CLEAR IS MUCH OF THE DAY LOOKS
TO BE IN A LULL FROM CONVECTION AFTER MORNING ACTIVITY DEPARTS TO THE
EAST AND THE ROUND OF STORMS WILL BE MORE FOCUSED LATER BETWEEN A 5PM
TO 3AM WINDOW. IN THE WAKE OF THE SAT SYSTEM...MUCH STEEPER LAPSE
RATES WILL SPREAD OVER THE AREA (7.0 TO 7.5 C/KM)(29-31C VERTICAL
TOTALS). ALOFT MUCH COLDER TEMPS WILL MOVE IN WITH H5 READINGS OF -15
TO - 16C. THIS WILL ALL SUPPORT SBCAPE OF 2000-3000 J/KG AS SFC
HEATING REACHES AROUND 80 DEGREES. THIS WILL ALL SUPPORT VIGOROUS
STORMS WITH ROBUST UPDRAFTS. CONCURRENT WITH THIS WILL BE AN OVERALL
DRIER ATMOSPHERE COLUMN AS WELL WITH PWS AROUND 1.2 INCHES. THIS WILL
LEND TO KEEPING STORMS MORE DISCRETE ALONG WITH AN EASTWARD DEEP
LAYER (0-6KM) SHEAR VECTOR OF 40-50KTS. EXPECTATIONS ARE FOR NOT MANY
(ISO/SCT) SUPERCELLS THAT WILL PACK QUITE THE PUNCH. LARGE HAIL >
GOLF BALL SIZE APPEARS VERY POSSIBLE ALONG WITH DAMAGING WINDS WHICH
ALSO COULD BE HIGHER END. DUE TO THIS POSSIBILITY OF SEEING
SIGNIFICANT TYPE WEATHER (>2 IN HAIL)...WILL UP OUR OUTLOOK TO SIG
OVER A DECENT PORTION OF THE NW. ELSEWHERE THE OUTLOOK WILL REMAIN
SIMILAR AS STORMS MAY LOSE SOME POTENCY AS THEY PUSH FURTHER EAST AND
GET LATER INTO THE OVERNIGHT. /CME/
LONG TERM...MONDAY THROUGH SATURDAY....MONDAY MORNING THE LARGE
CLOSED LOW IS EXPECTED TO BE CENTERED OVER THE UPPER MISSISSIPPI
VALLEY WITH ASSOCIATED LARGE AMPLITUDE UPPER LEVEL TROUGHING OVER
THE EASTERN TWO THIRDS OF THE CONUS. MODELS AGREE THAT THE
ASSOCIATED SURFACE LOW WILL BE OVER THE WESTERN GREAT LAKES REGION
MONDAY MORNING BUT THERE ARE TIMING DIFFERENCES WITH THE TRAILING
COLD FRONT THAT IS EXPECTED TO BE OVER SOUTHEAST MISSISSIPPI.
CONSENSUS PLACES THIS COLD FRONT AND THE BULK OF THE PRECIPITATION
JUST SOUTHEAST OF OUR CWA AT DAYBREAK BUT WL MAINTAIN LOW CHANCES OF
LIGHT RAIN IN OUR NORTHEAST THROUGH MID MORNING AS A WEAK SHORTWAVE
PASSES OVER OVERHEAD. DRY WEATHER IS EXPECTED AREAWIDE BY NOON.
SLIGHTLY COOLER AND MUCH DRIER AIR WILL FILTER INTO OUR CWA MONDAY
KNOCKING DEW POINTS INTO THE 40S DURING THE AFTERNOON. DRY WEATHER
IS EXPECTED TO LAST OVER OUR CWA THROUGH TUESDAY AS A SURFACE HIGH
MOVES EAST ACROSS OUR AREA. THIS SURFACE HIGH WILL SHIFT EAST
WEDNESDAY AND THE RESULTING RETURN FLOW WILL INCREASE MOISTURE TO
SUPPORT RAIN CHANCES AGAIN FROM THE WEST BY WEDNESDAY AFTERNOON.
WARMER THAN NORMAL TEMPERATURES AND GREATER RAIN CHANCES ARE
EXPECTED FOR THE END OF THE WEEK BUT THERE ARE SIGNIFICANT
DIFFERENCES IN THE MODELS WITH SOME MAIN FEATURES. THE NORTHERN
CLOSED LOW WILL MOVE SLOWLY EAST ACROSS THE GREAT LAKES REGION
TUESDAY AND WEDNESDAY AND BE OVER THE NEW ENGLAND STATES BY FRIDAY.
THIS LOW WILL TRY TO HELP SUPPORT ANOTHER COLD FRONT DROPPING INTO
OUR CWA THURSDAY INTO FRIDAY BUT INDUCED SHORTWAVE RIDGING
DOWNSTREAM OF A SECOND CLOSED LOW MOVING OVER THE DESERT SOUTHWEST
THURSDAY LOOKS TO IMPEDE THE COLD FRONT INTO OUR AREA. SHORTWAVES
ROUNDING THE BASE OF THE SOUTHERN CLOSED LOW LOOK TO COMBINE WITH
INCREASING MOISTURE AND DAYTIME HEATING FOR A ROUND OF CONVECTION
THURSDAY AND FRIDAY. BOTH GFS AND ECMWF OPEN THE CLOSED LOW AND
BRING THE REMAINING SHORTWAVE TROUGH ACROSS OUR REGION SATURDAY BUT
DIFFER ON THE SURFACE FEATURES WITH THE GFS DEPICTING A MUCH DEEPER
LOW AND STRONGER COLD FRONT ACROSS OUR AREA. FOR NOW...GREATEST POPS
THROUGH THE LONG TERM WILL BE CARRIED FRIDAY AND FRIDAY NIGHT. /22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 75 64 81 61 / 84 66 31 39
MERIDIAN 76 65 82 64 / 71 83 37 34
VICKSBURG 73 64 81 59 / 86 49 34 46
HATTIESBURG 77 66 84 65 / 86 78 33 28
NATCHEZ 75 64 82 60 / 91 54 28 42
GREENVILLE 73 63 81 57 / 58 47 49 57
GREENWOOD 74 63 79 59 / 56 55 44 56
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
JAN
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1025 AM CDT SAT APR 18 2015
.UPDATE... THINGS THIS MORNING ARE EVOLVING GENERALLY AS
ANTICIPATED...ALTHOUGH QUESTION MARKS GOING INTO LATE TODAY STILL
PERSIST IN SOME MEASURE OWING TO THUNDERSTORMS ANCHORED TO THE SE LA
COAST. THESE STORMS WERE PREVIOUSLY SPREADING A LIGHT RAIN SHIELD
INTO MY SOUTHERN ZONES...BUT THE NORTHWARD EXTENT OF THIS PRECIP HAS
SHRUNK IN THE LAST FEW HOURS. ALSO...VIGOROUS STORMS JUST SOUTH OF
THE COAST HAVE BEEN GRADUALLY LOSING COVERAGE SINCE DAYBREAK AND
THEY SHOULD EBB QUICKLY INTO MIDDAY AS UPPER JET PULLING BACK TO THE
WEST REMOVES MUCH OF THE UPPER LEVEL SUPPORT. HOWEVER...IF SAID
EVOLUTION DOES NOT COME TO PASS WITH HASTE THEN MOISTURE TRANSPORT
BLOCKING AND CLOUD COVER INTO SOME OF MY SOUTHERN ZONES WILL HINDER
POTENTIAL FOR VIGOROUS INLAND THUNDERSTORM FORMATION AS WE GO INTO
THIS AFTERNOON.
BUT ASSUMING THE LATTER CAVEAT IS NOT AN ISSUE...LATEST HRRR AND
DOWNSCALED NAM RUNS POINT TO WORRISOME STORMS MOVING INTO MY
SOUTHERN ZONES (ESPECIALLY SOUTH CENTRAL AND SE MS) ZONES FROM MID
AFTERNOON THROUGH MID EVENING. ATMOSPHERIC LAPSE RATES WILL MAINLY
BE AT OR LESS THAN 6 C/KM IN THE H700-H500 LAYER BUT MLCAPE PEAKING
OVER 1000 J/KG SHOULD BE SUFFICIENT GIVEN EXPECTED LOW LEVEL AND
DEEP LAYER SHEAR TO PRODUCE ORGANIZED STORMS. ONCE AGAIN...A FEW
TORNADOES CANNOT BE RULED OUT.
THERE IS NOT ENOUGH EVIDENCE YET TO GO CHANGING THE PREVIOUS
FORECAST AND SEVERE WEATHER EXPECTATIONS MUCH. HOWEVER...WE WILL BE
WATCHING TRENDS CLOSELY OVER THE NEXT FEW HOURS AND WILL SEE IF VERY
RECENT HRRR HINTS THAT SEVERE RISK WILL BE STRONGLY FOCUSING
SOUTHEAST OF THE NATCHEZ TRACE APPEAR SOLID. IF THAT IS THE CASE WE
WILL UPDATE ACCORDINGLY...BUT EVEN IF WE DO FOCUS THE SEVERE RISK
EVEN MORE CONSIDERABLY IN SOUTHERN ZONES THE RISK OF LOCALIZED
FLOODING PROBLEMS STILL LOOKS TO EXTEND ACROSS A MUCH LARGER PORTION
OF THE FORECAST AREA. /BB/
&&
.AVIATION...IFR CATEGORY STRATUS PREVAILS ACROSS THE TAF SITES THIS
MORNING WITH SHOWERS MOVING ACROSS HBG. EXPECT THESE CONDITIONS TO
PERSIST UNTIL LATE MORNING/EARLY AFTERNOON BEFORE FINALLY MIXING
OUT. SHRA WILL MOSTLY CONFINED TO LOCATIONS SOUTH OF THE HEZ-HBG
CORRIDOR THIS MORNING AS A CONVECTIVE COMPLEX SLIDES EASTWARD ALONG
THE COAST...BUT A NEW ROUND OF SHRA/TSRA IS EXPECTED BY MID/LATE
AFTERNOON LASTING INTO THE EVENING WITH AN APPROACHING DISTURBANCE.
THERE MAY BE A WINDOW OF OPPORTUNITY FOR BETTER FLYING CONDITIONS
DURING THE EARLY AFTERNOON...FOLLOWED BY POOR FLYING CONDITIONS
PERSISTING FROM MID/LATE AFTERNOON THROUGH THE EVENING.
/EC/15/
&&
.PREV DISCUSSION... /ISSUED 454 AM CDT SAT APR 18 2015/
SHORT TERM...TODAY THROUGH TONIGHT...AN ACTIVE WEATHER WEEKEND IS
IN STORE AS TWO ROUNDS OF SEVERE WEATHER ARE EXPECTED TO IMPACT THE
ARKLAMISS. THE FIRST ROUND WILL BE INITIATED BY INCREASINGLY
FAVORABLE CYCLONIC AND SHEARED FLOW DEVELOPING OVER THE LOWER MS
VALLEY REGION LATER THIS AFTERNOON AND EVENING. THE CONVECTIVE SYSTEM
CURRENTLY MOVING EAST ALONG THE THE LA COAST WILL DELAY TIMING OF THE
MORE SIGNIFICANT THUNDERSTORM ACTIVITY UNTIL MID/LATE AFTERNOON...BUT
VERY MOIST AND UNSTABLE AIR WITH PRECIPITABLE WATER VALUES > 1.75
INCHES AND ML CAPE NEAR 1000 J/KG SHOULD BE AVAILABLE FOR VIGOROUS
CONVECTIVE DEVELOPMENT AT THAT TIME. WITH DEEP LAYER AND LOW LEVEL
SHEAR ON THE INCREASE...STILL EXPECT ORGANIZED STORMS TO DEVELOP WITH
THE MOST FAVORABLE SET-UP FOR SEVERE WEATHER AND HEAVY RAINFALL
ALONG/SOUTH OF THE I-20 CORRIDOR...BUT WILL SAY THAT CONFIDENCE IS A
LITTLE SHAKIER NOW ON THIS SCENARIO BASED ON RECENT HIGH RES GUIDANCE
TRENDS. IF THE NEXT ROUND OF CONVECTIVE DOES NOT MATERIALIZE AS
ANTICIPATED DUE TO THE MORNING CONVECTION...OR IF IT DEVELOPS FARTHER
EAST...THEN IT IS POSSIBLE THAT MORE ROBUST CONVECTION WOULD IMPACT
NORTHERN PORTIONS OF THE ARKLAMISS AND THIS COULD ALLOW THE SEVERE
WEATHER/HEAVY RAINFALL THREAT TO SHIFT FARTHER NORTH AS WELL. STAY
TUNED FOR UPDATES TO THIS FORECAST LATER THIS MORNING AS CONVECTIVE
EVOLUTION HOPEFULLY BECOMES A LITTLE MORE CLEAR. /EC/
SUNDAY THROUGH SUNDAY NIGHT...MODELS FOR SUNDAY CONTINUE TO SUPPORT
THE RISK FOR SEVERE STORMS ALONG WITH SOME POTENTIAL FOR A HIGHER END
EVENT. WHAT IS STARTING TO BECOME MORE CLEAR IS MUCH OF THE DAY LOOKS
TO BE IN A LULL FROM CONVECTION AFTER MORNING ACTIVITY DEPARTS TO THE
EAST AND THE ROUND OF STORMS WILL BE MORE FOCUSED LATER BETWEEN A 5PM
TO 3AM WINDOW. IN THE WAKE OF THE SAT SYSTEM...MUCH STEEPER LAPSE
RATES WILL SPREAD OVER THE AREA (7.0 TO 7.5 C/KM)(29-31C VERTICAL
TOTALS). ALOFT MUCH COLDER TEMPS WILL MOVE IN WITH H5 READINGS OF -15
TO - 16C. THIS WILL ALL SUPPORT SBCAPE OF 2000-3000 J/KG AS SFC
HEATING REACHES AROUND 80 DEGREES. THIS WILL ALL SUPPORT VIGOROUS
STORMS WITH ROBUST UPDRAFTS. CONCURRENT WITH THIS WILL BE AN OVERALL
DRIER ATMOSPHERE COLUMN AS WELL WITH PWS AROUND 1.2 INCHES. THIS WILL
LEND TO KEEPING STORMS MORE DISCRETE ALONG WITH AN EASTWARD DEEP
LAYER (0-6KM) SHEAR VECTOR OF 40-50KTS. EXPECTATIONS ARE FOR NOT MANY
(ISO/SCT) SUPERCELLS THAT WILL PACK QUITE THE PUNCH. LARGE HAIL >
GOLF BALL SIZE APPEARS VERY POSSIBLE ALONG WITH DAMAGING WINDS WHICH
ALSO COULD BE HIGHER END. DUE TO THIS POSSIBILITY OF SEEING
SIGNIFICANT TYPE WEATHER (>2 IN HAIL)...WILL UP OUR OUTLOOK TO SIG
OVER A DECENT PORTION OF THE NW. ELSEWHERE THE OUTLOOK WILL REMAIN
SIMILAR AS STORMS MAY LOSE SOME POTENCY AS THEY PUSH FURTHER EAST AND
GET LATER INTO THE OVERNIGHT. /CME/
LONG TERM...MONDAY THROUGH SATURDAY....MONDAY MORNING THE LARGE
CLOSED LOW IS EXPECTED TO BE CENTERED OVER THE UPPER MISSISSIPPI
VALLEY WITH ASSOCIATED LARGE AMPLITUDE UPPER LEVEL TROUGHING OVER
THE EASTERN TWO THIRDS OF THE CONUS. MODELS AGREE THAT THE
ASSOCIATED SURFACE LOW WILL BE OVER THE WESTERN GREAT LAKES REGION
MONDAY MORNING BUT THERE ARE TIMING DIFFERENCES WITH THE TRAILING
COLD FRONT THAT IS EXPECTED TO BE OVER SOUTHEAST MISSISSIPPI.
CONSENSUS PLACES THIS COLD FRONT AND THE BULK OF THE PRECIPITATION
JUST SOUTHEAST OF OUR CWA AT DAYBREAK BUT WL MAINTAIN LOW CHANCES OF
LIGHT RAIN IN OUR NORTHEAST THROUGH MID MORNING AS A WEAK SHORTWAVE
PASSES OVER OVERHEAD. DRY WEATHER IS EXPECTED AREAWIDE BY NOON.
SLIGHTLY COOLER AND MUCH DRIER AIR WILL FILTER INTO OUR CWA MONDAY
KNOCKING DEW POINTS INTO THE 40S DURING THE AFTERNOON. DRY WEATHER
IS EXPECTED TO LAST OVER OUR CWA THROUGH TUESDAY AS A SURFACE HIGH
MOVES EAST ACROSS OUR AREA. THIS SURFACE HIGH WILL SHIFT EAST
WEDNESDAY AND THE RESULTING RETURN FLOW WILL INCREASE MOISTURE TO
SUPPORT RAIN CHANCES AGAIN FROM THE WEST BY WEDNESDAY AFTERNOON.
WARMER THAN NORMAL TEMPERATURES AND GREATER RAIN CHANCES ARE
EXPECTED FOR THE END OF THE WEEK BUT THERE ARE SIGNIFICANT
DIFFERENCES IN THE MODELS WITH SOME MAIN FEATURES. THE NORTHERN
CLOSED LOW WILL MOVE SLOWLY EAST ACROSS THE GREAT LAKES REGION
TUESDAY AND WEDNESDAY AND BE OVER THE NEW ENGLAND STATES BY FRIDAY.
THIS LOW WILL TRY TO HELP SUPPORT ANOTHER COLD FRONT DROPPING INTO
OUR CWA THURSDAY INTO FRIDAY BUT INDUCED SHORTWAVE RIDGING
DOWNSTREAM OF A SECOND CLOSED LOW MOVING OVER THE DESERT SOUTHWEST
THURSDAY LOOKS TO IMPEDE THE COLD FRONT INTO OUR AREA. SHORTWAVES
ROUNDING THE BASE OF THE SOUTHERN CLOSED LOW LOOK TO COMBINE WITH
INCREASING MOISTURE AND DAYTIME HEATING FOR A ROUND OF CONVECTION
THURSDAY AND FRIDAY. BOTH GFS AND ECMWF OPEN THE CLOSED LOW AND
BRING THE REMAINING SHORTWAVE TROUGH ACROSS OUR REGION SATURDAY BUT
DIFFER ON THE SURFACE FEATURES WITH THE GFS DEPICTING A MUCH DEEPER
LOW AND STRONGER COLD FRONT ACROSS OUR AREA. FOR NOW...GREATEST POPS
THROUGH THE LONG TERM WILL BE CARRIED FRIDAY AND FRIDAY NIGHT. /22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 75 64 81 61 / 83 66 31 39
MERIDIAN 76 65 82 64 / 73 78 37 34
VICKSBURG 73 64 81 59 / 87 53 34 46
HATTIESBURG 77 66 84 65 / 87 75 33 28
NATCHEZ 75 64 82 60 / 91 44 28 42
GREENVILLE 73 63 81 57 / 65 72 49 57
GREENWOOD 74 63 79 59 / 61 78 44 56
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
BB/15/EC/22
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1243 PM CDT Sat Apr 18 2015
.DISCUSSION...
Issued at 411 AM CDT SAT APR 18 2015
Overview: Closed and cut-off upper low now over central CO will be
the primary weather driver for the weekend. Feature will open up by
Sunday and move east in response to a shortwave trough digging
southeast through the Northern Rockies. Expect to see a several
rounds of active convection Saturday and Sunday.
Today - Sunday:
While eyes have been fixated on the closed upper low now over CO/NM
the real weather makers will be periodic vorticity lobes and
associated layered frontogenesis that rotate northeast out from
under the upper low. Little going on over the CWA early this morning
as we`re lacking any discernible feature to initiate any convection.
But we are finally seeing the long awaited next round of convection.
Regional radars have recently lit up from OK northward through
central KS albeit further west than we`ve been expecting. Favor
following the HRRR reflectivity trends, which have slowed down the
arrival of the KS/OK convection and latest NAM mass fields/h7
vorticity prog. Thus have pared back PoPs significantly for first
part of morning and slowed the eastward expansion of precipitation.
Even still this is a forecast which will need adjusting throughout
the day as the convection tied to the upper low has had repeated
false starts as well as expanding too fast to the east.
Thickening cloud cover and rain-cooled air will affect temperatures
over the western half of the CWA more so than the eastern half where
precipitation will move in later in the day. Precipitable water
values around two standard deviations above normal suggest potential
for 1"+ rains through tonight. Weak shear and MUCAPEs under 1000J/kg
favor convection remaining below severe limits.
Should see a lull in the rain later tonight and first part of Sunday
before the next wave of convection moves in. The upper low will have
opened up by then and will accelerate eastward. Anticipate convection
increasing as it moves east through the CWA in response to improving
upper level dynamics and low-level convergence associated with a
cold front. However, once again the 0-6km shear of 20-25kts and
modest MUCAPEs favor convection being sub-severe.
Monday - Tuesday:
A fairly deep upper trough stretching from MN through the Mid MS
Valley will influence our weather with widespread subsidence on the
backside of the trough. Abundant solar insolation will help offset
cold air advection but still result in below average temperatures.
Wednesday - Friday:
As the upper trough shifts east through the Great Lakes an upper
ridge will build eastward through the Rockies and into the
Central/Southern Plains. Medium range models are in agreement that a
cold front will surge through the region on Wednesday. However, they
disagree on whether or not convection will be generated. Moisture
fields look minimal and believe any shower activity will be widely
scattered.
As we get into Thursday and Friday the ECMWF and GFS both lift a
shortwave out of the southwestern U.S. but the GFS appears
unrealistic in deepening a surface over the Central High Plains and
spreading warm advection convection too far downstream. Will use a
blended forecast but overall confidence low for Thursday`s PoPs but
timing looks better for the PoPs on Friday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1240 PM CDT SAT APR 18 2015
Light to moderate rain, with perhaps an isolated, brief pocket of
heavy rain will move through the area through the next few hours.
There could be a couple isolated rumbles of thunder, but overall the
threat for lightning/thunder is minimal with this activity. There
will likely be a lull in the rain through the evening and
overnight hours, before another round picks up on Sunday morning.
Expect some spotty activity prior to sunrise Sunday, with confidence
rising in widespread moderate rain by the late morning to early
afternoon hours.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...Leighton
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
645 AM CDT Sat Apr 18 2015
.DISCUSSION...
Issued at 411 AM CDT SAT APR 18 2015
Overview: Closed and cut-off upper low now over central CO will be
the primary weather driver for the weekend. Feature will open up by
Sunday and move east in response to a shortwave trough digging
southeast through the Northern Rockies. Expect to see a several
rounds of active convection Saturday and Sunday.
Today - Sunday:
While eyes have been fixated on the closed upper low now over CO/NM
the real weather makers will be periodic vorticity lobes and
associated layered frontogenesis that rotate northeast out from
under the upper low. Little going on over the CWA early this morning
as we`re lacking any discernible feature to initiate any convection.
But we are finally seeing the long awaited next round of convection.
Regional radars have recently lit up from OK northward through
central KS albeit further west than we`ve been expecting. Favor
following the HRRR reflectivity trends, which have slowed down the
arrival of the KS/OK convection and latest NAM mass fields/h7
vorticity prog. Thus have pared back PoPs significantly for first
part of morning and slowed the eastward expansion of precipitation.
Even still this is a forecast which will need adjusting throughout
the day as the convection tied to the upper low has had repeated
false starts as well as expanding too fast to the east.
Thickening cloud cover and rain-cooled air will affect temperatures
over the western half of the CWA more so than the eastern half where
precipitation will move in later in the day. Precipitable water
values around two standard deviations above normal suggest potential
for 1"+ rains through tonight. Weak shear and MUCAPEs under 1000J/kg
favor convection remaining below severe limits.
Should see a lull in the rain later tonight and first part of Sunday
before the next wave of convection moves in. The upper low will have
opened up by then and will accelerate eastward. Anticipate convection
increasing as it moves east through the CWA in response to improving
upper level dynamics and low-level convergence associated with a
cold front. However, once again the 0-6km shear of 20-25kts and
modest MUCAPEs favor convection being sub-severe.
Monday - Tuesday:
A fairly deep upper trough stretching from MN through the Mid MS
Valley will influence our weather with widespread subsidence on the
backside of the trough. Abundant solar insolation will help offset
cold air advection but still result in below average temperatures.
Wednesday - Friday:
As the upper trough shifts east through the Great Lakes an upper
ridge will build eastward through the Rockies and into the
Central/Southern Plains. Medium range models are in agreement that a
cold front will surge through the region on Wednesday. However, they
disagree on whether or not convection will be generated. Moisture
fields look minimal and believe any shower activity will be widely
scattered.
As we get into Thursday and Friday the ECMWF and GFS both lift a
shortwave out of the southwestern U.S. but the GFS appears
unrealistic in deepening a surface over the Central High Plains and
spreading warm advection convection too far downstream. Will use a
blended forecast but overall confidence low for Thursday`s PoPs but
timing looks better for the PoPs on Friday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday Morning)
Issued at 641 AM CDT SAT APR 18 2015
A large area of showers and thunderstorms will evolve and lift north
through eastern KS and western MO during the morning and afternoon
hours. Generally VFR conditions with occasional MVFR cig/vsby
restrictions with the stronger storms. Should see the rain
temporarily end from west to east during the evening hours.
Another band of showers and isolated storms may reach eastern KS and
west central MO by the pre-dawn hours of Sunday morning with
generally VFR conditions.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
412 AM CDT Sat Apr 18 2015
.DISCUSSION...
Issued at 411 AM CDT SAT APR 18 2015
Overview: Closed and cut-off upper low now over central CO will be
the primary weather driver for the weekend. Feature will open up by
Sunday and move east in response to a shortwave trough digging
southeast through the Northern Rockies. Expect to see a several
rounds of active convection Saturday and Sunday.
Today - Sunday:
While eyes have been fixated on the closed upper low now over CO/NM
the real weather makers will be periodic vorticity lobes and
associated layered frontogenesis that rotate northeast out from
under the upper low. Little going on over the CWA early this morning
as we`re lacking any discernible feature to initiate any convection.
But we are finally seeing the long awaited next round of convection.
Regional radars have recently lit up from OK northward through
central KS albeit further west than we`ve been expecting. Favor
following the HRRR reflectivity trends, which have slowed down the
arrival of the KS/OK convection and latest NAM mass fields/h7
vorticity prog. Thus have pared back PoPs significantly for first
part of morning and slowed the eastward expansion of precipitation.
Even still this is a forecast which will need adjusting throughout
the day as the convection tied to the upper low has had repeated
false starts as well as expanding too fast to the east.
Thickening cloud cover and rain-cooled air will affect temperatures
over the western half of the CWA more so than the eastern half where
precipitation will move in later in the day. Precipitable water
values around two standard deviations above normal suggest potential
for 1"+ rains through tonight. Weak shear and MUCAPEs under 1000J/kg
favor convection remaining below severe limits.
Should see a lull in the rain later tonight and first part of Sunday
before the next wave of convection moves in. The upper low will have
opened up by then and will accelerate eastward. Anticipate convection
increasing as it moves east through the CWA in response to improving
upper level dynamics and low-level convergence associated with a
cold front. However, once again the 0-6km shear of 20-25kts and
modest MUCAPEs favor convection being sub-severe.
Monday - Tuesday:
A fairly deep upper trough stretching from MN through the Mid MS
Valley will influence our weather with widespread subsidence on the
backside of the trough. Abundant solar insolation will help offset
cold air advection but still result in below average temperatures.
Wednesday - Friday:
As the upper trough shifts east through the Great Lakes an upper
ridge will build eastward through the Rockies and into the
Central/Southern Plains. Medium range models are in agreement that a
cold front will surge through the region on Wednesday. However, they
disagree on whether or not convection will be generated. Moisture
fields look minimal and believe any shower activity will be widely
scattered.
As we get into Thursday and Friday the ECMWF and GFS both lift a
shortwave out of the southwestern U.S. but the GFS appears
unrealistic in deepening a surface over the Central High Plains and
spreading warm advection convection too far downstream. Will use a
blended forecast but overall confidence low for Thursday`s PoPs but
timing looks better for the PoPs on Friday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1129 PM CDT FRI APR 17 2015
VFR conditions will likely prevail at the terminals through the rest
of the overnight hours as the forecast for storms looks to have
slowed. Storms still look likely in the morning, but now it appears
that it will be after sunrise before anything sweeps across our
terminals. Thunderstorms are forecast to redevelop in the late
afternoon hours. Otherwise, easterly surface wind overnight will veer
to the south through the morning hours, with speeds remaining less
then 10 knots.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...Cutter
DISCUSSION...MJ
AVIATION...Cutter
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
259 PM CDT SAT APR 18 2015
.SYNOPSIS...
ISSUED AT 255 PM CDT SAT APR 18 2015
ANALYSIS OF THE 19Z MSL DATA SHOWED LOW PRESSURE CENTERED IN WESTERN
KANSAS WITH A WARM FRONT ACROSS NORTHERN KANSAS...A COLD FRONT INTO
THE OKLAHOMA/TEXAS PANHANDLE AND AN INVERTED TROUGH FROM SOUTHWEST
TO NORTH CENTRAL NEBRASKA. IN THE UPPER LEVELS...THE WATER VAPOR
IMAGERY SHOWED A CLOSED CYCLONIC CIRCULATION LOCATED IN EASTERN
COLORADO.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 255 PM CDT SAT APR 18 2015
THE CENTER OF STRONG CUT OFF LOW /H500 MB TEMP -25C/ IS NEAR AKRON
COLORADO THIS AFTERNOON. HIGH RES MODELS INSIST THAT
CONVECTION...AIDED BY A SIGNIFICANT PV ANOMALY ROTATING NORTHEAST
INTO WESTERN KANSAS AROUND THE LOW CENTER...WILL DEVELOP ONCE AGAIN
ACROSS NORTHWEST KANSAS AND SOUTHWEST NEBRASKA LATE THIS AFTERNOON
AND THIS EVENING. THE ACTIVITY WILL GROW UPSCALE MUCH LIKE LAST
NIGHT AS IT MOVES NORTH/NORTHEAST INTO THE REST OF WESTERN...CENTRAL
AND NORTH CENTRAL NEBRASKA TONIGHT.
AS FAR AS SEVERE POTENTIAL...GOOD SURFACE HEATING UNDERWAY ATTM
ACROSS SOUTHWEST NEBRASKA AND NORTHWEST KANSAS. EXPECTING MUCAPE ON
THE ORDER OF 1500 J/KG BY LATE AFTERNOON INTO THE EVENING HOURS. ONE
WEAKNESS ARE THE WIND FIELDS ARE FAIRLY LIGHT...AND NOT A A LOT OF
VEERING WITH HEIGHT. NEVERTHELESS WITH THE STEEP LOW AND MID LEVEL
LAPSE RATES...WILL SEE SOME VIGOROUS UPDRAFTS...AND SOME HAIL LIKELY
WITH THOSE STRONGER UPDRAFTS. TORNADO POTENTIAL IS NOT ZERO...BUT
AGAIN WITH THE WEAK WIND FIELDS AND LIMITED VEERING...NOT EXPECTING
THAT TO BE THE PRIMARY RISK. IF A TORNADO OCCURS IT WOULD MORE THAN
LIKELY BE WEAK. K INDICES ARE HIGH...AND LOCALLY HEAVY RAINFALL
WILL BE POSSIBLE.
THE CLOSED H500 MB CIRCULATION IS FORECASTED TO MIGRATE INTO
NORTHWEST KANSAS BY SUNDAY MORNING...AND CONTINUE EAST ACROSS KANSAS
DURING THE DAY. A SMALL DEFORMATION BAND OF PRECIPITATION IS LIKELY
ON THE NORTH AND WEST SIDE OF THE TRACK. THE EXACT TRACK OF THE LOW
CENTER IS UNCERTAIN...AS CONVECTION LIKELY TO INFLUENCE THE MASS
FIELD AND EXPECT THE FINAL TRACK COULD END UP A LITTLE FARTHER
NORTH. THIS IS HINTED IN THE LATEST RUN OF THE RAP MODEL. OTHERWISE
A COLD FRONT ASSOCIATED WITH A SEPARATE NORTHERN STREAM SYSTEM WILL
CRASH THROUGH THE AREA...BRINGING GUSTY NORTHWEST WINDS TO THE
REGION.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 255 PM CDT SAT APR 18 2015
MEDIUM RANGE...(SUNDAY NIGHT THROUGH TUESDAY)
THE UPPER LEVEL LOW ACROSS COLORADO WILL LIFT OUT AND COLLIDE WITH
AN UPPER LEVEL SHORT WAVE ACROSS ACROSS THE NORTHERN GREAT LAKES
FORMING A VERY LARGE CLOSED UPPER LOW. UPSTREAM HEIGHTS RISE SHARPLY
ACROSS NRN CANADA SUPPORTING A BROAD AREA OF HIGH PRESSURE WHICH
CIRCULATE COOL AIR SOUTH THROUGH THE PLAINS AND MIDWEST. THIS KEEPS
THE FORECAST AREA IN COOL NORTHWEST FLOW. DAYTIME MIXING PRODUCES
PARTLY CLOUDY SKIES MONDAY AND TUESDAY PLACING A LIMIT ON HEATING.
MONDAY WOULD BE A WINDY DAY WITH NORTHWEST WINDS INCREASING TO 20
TO 30 MPH IN THE AFTN WHICH WEAKEN AT SUNSET. WINDS STAY REASONABLY
STRONG SUNDAY NIGHT ALSO. THE EFFECT ON TEMPERATURES WOULD BE FOR
LOWS MONDAY MORNING FALLING INTO THE UPPER 20S ACROSS WESTERN
NEBRASKA BUT ABOVE FREEZING EAST OF HIGHWAY 83. LOWS FALL BELOW
FREEZING EVERYWHERE MONDAY NIGHT EXCEPT ALONG HIGHWAY 281. HIGHS
RISE INTO THE 50S MONDAY AND LOWER 60S TUESDAY.
THE FORECAST IS DRY AND THE MODELS INDICATE DEW POINTS FALL INTO
TEENS AND 20S SUNDAY NIGHT THROUGH TUESDAY. THE RISK TO THE FORECAST
IS THAT THE VERY DRY AIR COULD SUPPORT COLDER LOWS THAN FORECAST BUT
THAT WOULD COMPETE DIRECTLY WITH THE WARM WET GROUND FROM THE HEAVY
RAINFALL.
EXTENDED RANGE...(TUESDAY NIGHT THROUGH SATURDAY)
A RIDGE IN WESTERN NORTH AMERICA CONTINUES TO BUILD INTO THE
NORTHWEST TERRITORIES AND NORTHERN ALBERTA OPENING UP A PATH FROM
NUNAVUT IN EXTREME NORTHERN CANADA TO NORTH CENTRAL AND NORTHEAST
NEBRASKA. AS A RESULT...TEMPERATURES ARE EXPECTED TO BE A LITTLE
BELOW THE SEASONAL AVERAGES IN THE NORTHEAST NEBRASKA SANDHILLS AND
THE NIOBRARA VALLEY WITH NIGHTTIME TEMPERATURES AT OR BELOW FREEZING
INTO FRIDAY MORNING. EVEN IN THE WESTERN SANDHILLS...THE EASTERN
PANHANDLE AND SOUTHWEST NEBRASKA WILL BE SLIGHTLY BELOW AVERAGE
WITH LOWS IN THE LOW TO MID 30S.
IN THE SOUTHWEST STATES...A TROUGH DIGS INTO SOUTHERN CALIFORNIA
RESULTING IN SOUTHWEST FLOW ALOFT ACROSS THE CENTRAL PLAINS. A WEAK
INVERTED TROUGH MOVING ACROSS THE PLAINS COULD BRING THE POSSIBILITY
OF SHOWERS TO CENTRAL AND WESTERN NEBRASKA THURSDAY THROUGH
SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1228 PM CDT SAT APR 18 2015
LARGE UPPER LEVEL LOW CONTINUES TO MOVE ONLY VERY SLOWLY ACROSS
EASTERN COLORADO. EXPECT ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS TO DEVELOP AS A RESULT THIS AFTERNOON AND TONIGHT.
THE BEST CONCENTRATION OF SHOWERS AND STORMS WILL BE ACROSS
CENTRAL AND SOUTHWEST NEBRASKA...INCLUDING THE KLBF TAF SITE. LATE
TONIGHT A COLD FRONT WILL QUICKLY MOVE SOUTHEAST THROUGH THE
AREA...THIS WILL BRING MVFR AND POSSIBLE IFR CEILINGS WITH IT FROM
AROUND 07Z TO 16Z SUNDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SPRINGER
SHORT TERM...TAYLOR
MEDIUM RANGE...CDC
EXTENDED RANGE...SPRINGER
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
106 PM CDT SAT APR 18 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT SAT APR 18 2015
SPC SUGGESTED SIGNIFICANT SEVERE WEATHER POTENTIAL THIS AFTERNOON
AND EARLY THIS EVENING ACROSS PARTS OF SOUTHWEST AND NCNTL NEB. A
PORTION OF THE LOW PRESSURE ACROSS SWRN KS THIS MORNING IS
EXPECTED TO LIFT NORTHEAST THROUGH SCNTL AND ERN NEB THIS
AFTERNOON SETTING UP A UNSTABLE WARM SECTOR FROM ROUGHLY IMPERIAL
TO ONEILL.
ALTHOUGH THE RAP IS FAIRLY QUIET THE NAM AND HRRR SBN MODELS
SUGGEST REASONABLE POTENTIAL FOR CONVECTIVE DEVELOPMENT THIS AFTN
IF SKIES PARTIALLY CLEAR ALLOWING FOR TEMPERATURES TO RISE INTO
THE MID AND UPPER 60S. SATELLITE SHOWS CLEARING THIS MORNING
ACROSS CNTL HIGH PLAINS OF KS/COLO AND IT IS BELIEVED THIS
CLEARING WILL MOVE INTO SCNTL NEB THIS AFTN.
THE STORM ACTIVITY COULD BEGIN AS EARLY AS 18Z IN THE SOUTHWEST
WITH THE NAM SOLN OR AS LATE AS 21Z-00Z IN THE HRRR MODEL.
SATELLITE TIMING TOOLS INDICATE THE CLEARING ACROSS KS COULD
REACH SOUTHWEST NEB BY 13-15Z THIS MORNING WHICH WOULD PROVIDE A
GOOD START FOR MODEST HEATING GIVEN THAT THIS CLEARING AREA WOULD
TEND TO FILL IN WITH DEVELOPING CUMULUS.
ONE WEAKNESS ARE THE WIND FIELDS 500MB AND BELOW WHICH ARE LIGHT
PRODUCING BULK SHEAR VALUES OF 30KT OR LESS WHICH MIGHT SUPPORT
MORE OF HEAVY RAIN THREAT. STILL TEMPERATURES ALOFT WILL BE VERY
COLD AS THE H500MB LOW ACROSS COLO MOVES EAST TO NEAR
LIMON/SPRINGFIELD. WINDS AT 300MB ARE STRONG NEAR 65KT
POTENTIALLY ENHANCING UPDRAFTS AND PROVIDING VENTILATION.
FREEZING LEVELS ARE NEAR 5KFT SUPPORTING A LOW TOP STORM
ENVIRONMENT AND GOOD POTENTIAL FOR HAIL. THE NAM IS PRODUCING
AROUND 2000 J/KG OF CAPE AT NORTH PLATTE AND BROKEN BOW WHILE THE
RAP AND OTHER MODELS SHOW HALF OR LESS THAT VALUE.
NORTHWEST WINDS WILL SWEEP IN FROM THE WEST IN THE WAKE OF THE
DISTURBANCE TONIGHT. THIS SHOULD PRODUCE DRYING AND DECREASING
RAIN CHANCES FROM MIDNIGHT ONWARD.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 328 AM CDT SAT APR 18 2015
SUNDAY WILL SEE THE STRONG LOW PRESSURE WEAKENING AS IT PUSHES
EAST WHILE A TROUGH DIGS ACROSS THE CANADIAN PLAINS. SOME
LINGERING SUNDAY MORNING SHOWERS ARE POSSIBLE IN THE EASTERN
ZONES...HOWEVER THE BIGGER EVENTS OF THE DAY WILL BE THE CAA AND
INCREASING NW WINDS. AS THE LOW PUSHES ACROSS KS...DRY AIR WILL
QUICKLY FILL IN BEHIND...RESULTING IN DECREASING CLOUDS FROM WEST
TO EAST IN THE MORNING. BY AFTERNOON SHOULD SEE MOSTLY SUNNY
SKIES FOR ALL. THE SUN WILL COMBINE WITH THE STRONG NW WINDS
/GUSTING TO 30 TO 40 MPH/ TO PROMOTE GOOD MIXING OF THE BL AND
OFFSET THE CAA AND TEMPS PUSH INTO THE 50S.
EARLY IN THE WEEK THE TROUGH DIGS TOWARDS THE GREAT LAKES REGION
AND ABSORBS THE SOUTHERN LOW. ELONGATED SFC HIGH PRESSURE BUILDS
ACROSS THE HIGH PLAINS. THE ACTIVE WEATHER IS WELL TO THE NE
ALTHOUGH A FEW UPPER LEVEL DISTURBANCES WILL RIDE ALONG THE NW
FLOW OVERHEAD AND BRING SOME PASSING CLOUDS AT TIMES. LIMITED
MOISTURE IN THE LOWER LEVELS AND MODELS/FORECAST ARE DRY. TEMPS
TO START THE WEEK WILL BE CHILLY IN THE MORNING WITH MOST AREAS
NEAR OR BELOW THE FREEZING MARK. STILL A COUPLE OF WEEKS FROM
TYPICAL LAST FREEZE FOR MOST OF THE AREA...SO NO HEADLINES NEEDED
YET. HIGHS REBOUND NICELY WITH A WARMING TREND WITH 60S MAYBE 70
FOR WED AND THURS.
EYES THEN FOCUS ON A TROUGH AS IT DIGS ACROSS THE SOUTHWEST.
MODELS IN GOOD AGREEMENT DEVELOPING A CLOSED 500 MB LOW NEAR SRN
CAL BY THURS. THE LOW THEN LIFTS TOWARDS THE 4 CORNERS WHILE
BECOMING AN OPEN WAVE. THE WAVE WILL THEN PUSH ACROSS THE PLAINS
TO END THE WEEK. THIS WILL BRING A RETURN OF THE ACTIVE
WEATHER...AND WILL HAVE POPS TOWARDS THE END OF THE EXTENDED
PERIOD. STILL HAVE SOME LOCATION AND TIMING ISSUES TO IRON OUT
WHICH IS TYPICAL THIS FAR OUT SO POPS KEPT BELOW 50 PERCENT FOR
NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1228 PM CDT SAT APR 18 2015
LARGE UPPER LEVEL LOW CONTINUES TO MOVE ONLY VERY SLOWLY ACROSS
EASTERN COLORADO. EXPECT ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS TO DEVELOP AS A RESULT THIS AFTERNOON AND TONIGHT.
THE BEST CONCENTRATION OF SHOWERS AND STORMS WILL BE ACROSS
CENTRAL AND SOUTHWEST NEBRASKA...INCLUDING THE KLBF TAF SITE. LATE
TONIGHT A COLD FRONT WILL QUICKLY MOVE SOUTHEAST THROUGH THE
AREA...THIS WILL BRING MVFR AND POSSIBLE IFR CEILINGS WITH IT FROM
AROUND 07Z TO 16Z SUNDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...TAYLOR
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
625 AM CDT SAT APR 18 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT SAT APR 18 2015
SPC SUGGESTED SIGNIFICANT SEVERE WEATHER POTENTIAL THIS AFTERNOON
AND EARLY THIS EVENING ACROSS PARTS OF SOUTHWEST AND NCNTL NEB. A
PORTION OF THE LOW PRESSURE ACROSS SWRN KS THIS MORNING IS
EXPECTED TO LIFT NORTHEAST THROUGH SCNTL AND ERN NEB THIS
AFTERNOON SETTING UP A UNSTABLE WARM SECTOR FROM ROUGHLY IMPERIAL
TO ONEILL.
ALTHOUGH THE RAP IS FAIRLY QUIET THE NAM AND HRRR SBN MODELS
SUGGEST REASONABLE POTENTIAL FOR CONVECTIVE DEVELOPMENT THIS AFTN
IF SKIES PARTIALLY CLEAR ALLOWING FOR TEMPERATURES TO RISE INTO
THE MID AND UPPER 60S. SATELLITE SHOWS CLEARING THIS MORNING
ACROSS CNTL HIGH PLAINS OF KS/COLO AND IT IS BELIEVED THIS
CLEARING WILL MOVE INTO SCNTL NEB THIS AFTN.
THE STORM ACTIVITY COULD BEGIN AS EARLY AS 18Z IN THE SOUTHWEST
WITH THE NAM SOLN OR AS LATE AS 21Z-00Z IN THE HRRR MODEL.
SATELLITE TIMING TOOLS INDICATE THE CLEARING ACROSS KS COULD
REACH SOUTHWEST NEB BY 13-15Z THIS MORNING WHICH WOULD PROVIDE A
GOOD START FOR MODEST HEATING GIVEN THAT THIS CLEARING AREA WOULD
TEND TO FILL IN WITH DEVELOPING CUMULUS.
ONE WEAKNESS ARE THE WIND FIELDS 500MB AND BELOW WHICH ARE LIGHT
PRODUCING BULK SHEAR VALUES OF 30KT OR LESS WHICH MIGHT SUPPORT
MORE OF HEAVY RAIN THREAT. STILL TEMPERATURES ALOFT WILL BE VERY
COLD AS THE H500MB LOW ACROSS COLO MOVES EAST TO NEAR
LIMON/SPRINGFIELD. WINDS AT 300MB ARE STRONG NEAR 65KT
POTENTIALLY ENHANCING UPDRAFTS AND PROVIDING VENTILATION.
FREEZING LEVELS ARE NEAR 5KFT SUPPORTING A LOW TOP STORM
ENVIRONMENT AND GOOD POTENTIAL FOR HAIL. THE NAM IS PRODUCING
AROUND 2000 J/KG OF CAPE AT NORTH PLATTE AND BROKEN BOW WHILE THE
RAP AND OTHER MODELS SHOW HALF OR LESS THAT VALUE.
NORTHWEST WINDS WILL SWEEP IN FROM THE WEST IN THE WAKE OF THE
DISTURBANCE TONIGHT. THIS SHOULD PRODUCE DRYING AND DECREASING
RAIN CHANCES FROM MIDNIGHT ONWARD.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 328 AM CDT SAT APR 18 2015
SUNDAY WILL SEE THE STRONG LOW PRESSURE WEAKENING AS IT PUSHES
EAST WHILE A TROUGH DIGS ACROSS THE CANADIAN PLAINS. SOME
LINGERING SUNDAY MORNING SHOWERS ARE POSSIBLE IN THE EASTERN
ZONES...HOWEVER THE BIGGER EVENTS OF THE DAY WILL BE THE CAA AND
INCREASING NW WINDS. AS THE LOW PUSHES ACROSS KS...DRY AIR WILL
QUICKLY FILL IN BEHIND...RESULTING IN DECREASING CLOUDS FROM WEST
TO EAST IN THE MORNING. BY AFTERNOON SHOULD SEE MOSTLY SUNNY
SKIES FOR ALL. THE SUN WILL COMBINE WITH THE STRONG NW WINDS
/GUSTING TO 30 TO 40 MPH/ TO PROMOTE GOOD MIXING OF THE BL AND
OFFSET THE CAA AND TEMPS PUSH INTO THE 50S.
EARLY IN THE WEEK THE TROUGH DIGS TOWARDS THE GREAT LAKES REGION
AND ABSORBS THE SOUTHERN LOW. ELONGATED SFC HIGH PRESSURE BUILDS
ACROSS THE HIGH PLAINS. THE ACTIVE WEATHER IS WELL TO THE NE
ALTHOUGH A FEW UPPER LEVEL DISTURBANCES WILL RIDE ALONG THE NW
FLOW OVERHEAD AND BRING SOME PASSING CLOUDS AT TIMES. LIMITED
MOISTURE IN THE LOWER LEVELS AND MODELS/FORECAST ARE DRY. TEMPS
TO START THE WEEK WILL BE CHILLY IN THE MORNING WITH MOST AREAS
NEAR OR BELOW THE FREEZING MARK. STILL A COUPLE OF WEEKS FROM
TYPICAL LAST FREEZE FOR MOST OF THE AREA...SO NO HEADLINES NEEDED
YET. HIGHS REBOUND NICELY WITH A WARMING TREND WITH 60S MAYBE 70
FOR WED AND THURS.
EYES THEN FOCUS ON A TROUGH AS IT DIGS ACROSS THE SOUTHWEST.
MODELS IN GOOD AGREEMENT DEVELOPING A CLOSED 500 MB LOW NEAR SRN
CAL BY THURS. THE LOW THEN LIFTS TOWARDS THE 4 CORNERS WHILE
BECOMING AN OPEN WAVE. THE WAVE WILL THEN PUSH ACROSS THE PLAINS
TO END THE WEEK. THIS WILL BRING A RETURN OF THE ACTIVE
WEATHER...AND WILL HAVE POPS TOWARDS THE END OF THE EXTENDED
PERIOD. STILL HAVE SOME LOCATION AND TIMING ISSUES TO IRON OUT
WHICH IS TYPICAL THIS FAR OUT SO POPS KEPT BELOW 50 PERCENT FOR
NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 625 AM CDT SAT APR 18 2015
MIXED FLIGHT CONDITIONS CONTINUE TODAY. VFR IS EXPECTED THIS
MORNING ACROSS SWRN/SCNTL NEB AS A CLEAR SLOT MOVES IN FROM THE
SOUTH. THIS AREA OF CLEARING WILL WARM UP AND DESTABLIZE THIS
AFTN WITH SCATTERED SHRA/TSTM COVERAGE DEVELOPING 18Z-21Z AND
CONTINUING THROUGH ABOUT 03Z THIS EVENING. STORMS WHICH DEVELOP
WILL LIKELY LIFT NORTH TOWARD KVTN THIS EVENING AROUND 03Z-06Z.
A COLD FRONT WILL SWEEP INTO THE FCST AREA FROM THE NORTHWEST TONIGHT
BETWEEN 03Z-09Z PRODUCING MVFR CIGS AND SCATTERED SHOWERS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
328 AM CDT SAT APR 18 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT SAT APR 18 2015
SPC SUGGESTED SIGNIFICANT SEVERE WEATHER POTENTIAL THIS AFTERNOON
AND EARLY THIS EVENING ACROSS PARTS OF SOUTHWEST AND NCNTL NEB. A
PORTION OF THE LOW PRESSURE ACROSS SWRN KS THIS MORNING IS
EXPECTED TO LIFT NORTHEAST THROUGH SCNTL AND ERN NEB THIS
AFTERNOON SETTING UP A UNSTABLE WARM SECTOR FROM ROUGHLY IMPERIAL
TO ONEILL.
ALTHOUGH THE RAP IS FAIRLY QUIET THE NAM AND HRRR SBN MODELS
SUGGEST REASONABLE POTENTIAL FOR CONVECTIVE DEVELOPMENT THIS AFTN
IF SKIES PARTIALLY CLEAR ALLOWING FOR TEMPERATURES TO RISE INTO
THE MID AND UPPER 60S. SATELLITE SHOWS CLEARING THIS MORNING
ACROSS CNTL HIGH PLAINS OF KS/COLO AND IT IS BELIEVED THIS
CLEARING WILL MOVE INTO SCNTL NEB THIS AFTN.
THE STORM ACTIVITY COULD BEGIN AS EARLY AS 18Z IN THE SOUTHWEST
WITH THE NAM SOLN OR AS LATE AS 21Z-00Z IN THE HRRR MODEL.
SATELLITE TIMING TOOLS INDICATE THE CLEARING ACROSS KS COULD
REACH SOUTHWEST NEB BY 13-15Z THIS MORNING WHICH WOULD PROVIDE A
GOOD START FOR MODEST HEATING GIVEN THAT THIS CLEARING AREA WOULD
TEND TO FILL IN WITH DEVELOPING CUMULUS.
ONE WEAKNESS ARE THE WIND FIELDS 500MB AND BELOW WHICH ARE LIGHT
PRODUCING BULK SHEAR VALUES OF 30KT OR LESS WHICH MIGHT SUPPORT
MORE OF HEAVY RAIN THREAT. STILL TEMPERATURES ALOFT WILL BE VERY
COLD AS THE H500MB LOW ACROSS COLO MOVES EAST TO NEAR
LIMON/SPRINGFIELD. WINDS AT 300MB ARE STRONG NEAR 65KT
POTENTIALLY ENHANCING UPDRAFTS AND PROVIDING VENTILATION.
FREEZING LEVELS ARE NEAR 5KFT SUPPORTING A LOW TOP STORM
ENVIRONMENT AND GOOD POTENTIAL FOR HAIL. THE NAM IS PRODUCING
AROUND 2000 J/KG OF CAPE AT NORTH PLATTE AND BROKEN BOW WHILE THE
RAP AND OTHER MODELS SHOW HALF OR LESS THAT VALUE.
NORTHWEST WINDS WILL SWEEP IN FROM THE WEST IN THE WAKE OF THE
DISTURBANCE TONIGHT. THIS SHOULD PRODUCE DRYING AND DECREASING
RAIN CHANCES FROM MIDNIGHT ONWARD.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 328 AM CDT SAT APR 18 2015
SUNDAY WILL SEE THE STRONG LOW PRESSURE WEAKENING AS IT PUSHES
EAST WHILE A TROUGH DIGS ACROSS THE CANADIAN PLAINS. SOME
LINGERING SUNDAY MORNING SHOWERS ARE POSSIBLE IN THE EASTERN
ZONES...HOWEVER THE BIGGER EVENTS OF THE DAY WILL BE THE CAA AND
INCREASING NW WINDS. AS THE LOW PUSHES ACROSS KS...DRY AIR WILL
QUICKLY FILL IN BEHIND...RESULTING IN DECREASING CLOUDS FROM WEST
TO EAST IN THE MORNING. BY AFTERNOON SHOULD SEE MOSTLY SUNNY
SKIES FOR ALL. THE SUN WILL COMBINE WITH THE STRONG NW WINDS
/GUSTING TO 30 TO 40 MPH/ TO PROMOTE GOOD MIXING OF THE BL AND
OFFSET THE CAA AND TEMPS PUSH INTO THE 50S.
EARLY IN THE WEEK THE TROUGH DIGS TOWARDS THE GREAT LAKES REGION
AND ABSORBS THE SOUTHERN LOW. ELONGATED SFC HIGH PRESSURE BUILDS
ACROSS THE HIGH PLAINS. THE ACTIVE WEATHER IS WELL TO THE NE
ALTHOUGH A FEW UPPER LEVEL DISTURBANCES WILL RIDE ALONG THE NW
FLOW OVERHEAD AND BRING SOME PASSING CLOUDS AT TIMES. LIMITED
MOISTURE IN THE LOWER LEVELS AND MODELS/FORECAST ARE DRY. TEMPS
TO START THE WEEK WILL BE CHILLY IN THE MORNING WITH MOST AREAS
NEAR OR BELOW THE FREEZING MARK. STILL A COUPLE OF WEEKS FROM
TYPICAL LAST FREEZE FOR MOST OF THE AREA...SO NO HEADLINES NEEDED
YET. HIGHS REBOUND NICELY WITH A WARMING TREND WITH 60S MAYBE 70
FOR WED AND THURS.
EYES THEN FOCUS ON A TROUGH AS IT DIGS ACROSS THE SOUTHWEST.
MODELS IN GOOD AGREEMENT DEVELOPING A CLOSED 500 MB LOW NEAR SRN
CAL BY THURS. THE LOW THEN LIFTS TOWARDS THE 4 CORNERS WHILE
BECOMING AN OPEN WAVE. THE WAVE WILL THEN PUSH ACROSS THE PLAINS
TO END THE WEEK. THIS WILL BRING A RETURN OF THE ACTIVE
WEATHER...AND WILL HAVE POPS TOWARDS THE END OF THE EXTENDED
PERIOD. STILL HAVE SOME LOCATION AND TIMING ISSUES TO IRON OUT
WHICH IS TYPICAL THIS FAR OUT SO POPS KEPT BELOW 50 PERCENT FOR
NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1213 AM CDT SAT APR 18 2015
THUNDERSTORMS IN SOUTHWEST NEBRASKA WILL STILL BE CAPABLE OF
PRODUCING HAIL AND HEAVY RAIN THROUGH THE NIGHT INTO EARLY
SATURDAY. AS FOR HAVING THUNDER AT ANY ONE POINT...THE
PROBABILITY IS LOW. PROJECTING FROM THE CURRENT RADAR IMAGERY
INDICATES THAT THUNDERSTORMS WILL PASS CLOSE ENOUGH TO KLBF TO BE
INCLUDED IN THE TAF UNTIL ABOUT 08Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
948 PM EDT SUN APR 19 2015
.SYNOPSIS...
WIDESPREAD RAIN WILL DEVELOP OVER OUR AREA LATER TONIGHT INTO
EARLY MONDAY AS A STORM SYSTEM MOVES THROUGH THE GREAT LAKES.
AFTER A BRIEF LULL IN RAIN MIDDAY MONDAY, ANOTHER ROUND OF SHOWERS
IS POSSIBLE MONDAY AFTERNOON AND EVENING. DURING THAT TIME
SCATTERED THUNDERSTORMS ARE POSSIBLE. WE WILL REMAIN UNSETTLED AND
VERY COOL THE REST OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
940 PM UPDATE...
TIMING OF RAINFALL LOOKS TO BE ON TRACK. I TWEAKED THE OVERNIGHT
WIND GRIDS A BIT. WE STILL HAVE GUSTS OVER 40 MPH ON THE HILLTOPS
ABOVE 1500 FEET. I INCREASED WIND IN THE LAKE PLAIN, SHOWING SOME
GUSTS IN THE LOWER 30S AT KSYR. RUC SOUNDINGS SEEM A BIT LOW HERE
GIVEN FAVORABLE SOUTHEAST DOWNSLOPING AND MAV GUIDANCE SHOWING
SUSTAINED WINDS IN THE LOWER 20S. OTHERWISE PREVIOUS AFD IS
BELOW...
300 PM UPDATE...
A BEAUTIFUL END TO OUR WEEKEND ALBEIT A GOOD 10 DEGREES OR SO
COOLER THAN YESTERDAY AFTERNOON. I HOPE YOU ENJOYED THE WEEKEND
BECAUSE THE WEATHER THROUGH THE END OF THE MONTH DOESN`T LOOK ALL
THAT GOOD.
WE ARE ALREADY SEEING SIGNS OF THOSE CHANGES IN THE FORM OF SOME
THIN WISPY HIGH CLOUDS. THESE ARE WELL AHEAD OF AN AREA OF LOW
PRESSURE NOW OVER ILLINOIS THAT WILL TRACK THROUGH THE GREAT
LAKES MONDAY. A LARGE SHIELD OF RAIN WELL AHEAD OF A WARM FRONT
WITH THIS SYSTEM WILL MOVE IN TONIGHT. NOT EXPECTING ANY HYDRO
ISSUES BUT A QUICK SHOT OF STEADY RAIN IS LIKELY FOR EVERYONE.
THE BIG STORY TONIGHT MAY BE THE WIND, ESPECIALLY ACROSS THE
HIGHER ELEVATIONS THAT FAVOR A SOUTHEAST WIND FLOW. WHILE WE ARE
VERY STABLE JUST A FEW THOUSAND FEET UP AND RAIN WILL LIKELY
TEMPER WINDS A BIT, STRONG WINDS UNDER THE INVERSION WILL FAVOR
LOCALLY STRONG GUSTS ON THE HILLTOPS. IN GENERAL GUSTS TO 20 MPH
ARE LIKELY TONIGHT FOR MOST OF US. FAVORED TERRAIN AREAS WILL
GUST BETWEEN 30 AND 40 MPH. THIS INCLUDES THE CATSKILLS, HIGHER
TERRAIN OF NEPA AND THE WESTERN SOUTHERN TIER AND THE HILLS SOUTH
OF SYRACUSE. WOULD NOT BE SURPRISED TO SEE A FEW GUSTS ABOVE 40
MPH ACROSS AREAS SUCH AS SEMPRONIUS, POMPEY, GEORGETOWN, IN THE
FAVORED SOUTHEAST FLOW AREAS SOUTH OF SYRACUSE.
MONDAY...
MODEL CONSENSUS STILL FAVORS THE STEADIER RAIN SLIDING EAST AND
PERHAPS EVEN OUT OF OUR AREA BY MIDDAY. MOST OF OUR AREA WILL GET
INTO THE WARM SECTOR BY AFTERNOON AND PERHAPS EVEN A FEW BREAKS IN
THE CLOUD COVER. THIS MAY GIVE US JUST ENOUGH INSTABILITY,
ESPECIALLY IF WE CAN SEE SOME SUN, TO COMBINE WITH A COLD FRONT
APPROACHING DURING THE EVENING FOR SOME THUNDERSTORMS. SPC DAY 2
OUTLOOK HAS MOVED THE SLIGHT RISK TOWARD OUR AREA AND JUST BRUSHES
SOUTHERN LUZERNE COUNTY. IN ADDITION A MARGINAL RISK (OLD SEE TEXT
FROM PAST YEARS) IS NOW UP TO NEAR THE NY STATE THRUWAY. WILL
CONTINUE TO MENTION T-STORMS IN THE FORECAST. SHEAR VALUES ARE
GOOD BUT IT WILL COME DOWN TO HOW MUCH INSTABILITY WE CAN REALIZE
DURING THE AFTERNOON TO DETERMINE SEVERE RISK.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
345 PM UPDATE...
A COLD FRONT WILL BE MOVING THROUGH THE AREA MONDAY EVENING. WITH
LINGERING INSTABILITY, THUNDERSTORMS WILL BE POSSIBLE ACROSS THE
ENTIRE AREA. ALL HI RESOLUTION GUIDANCE POINTS TO THE POTENTIAL
OF A SQUALL LINE BETWEEN 21Z MONDAY AND 03Z TUESDAY ROUGHLY FROM
THE SOUTHERN TIER OF NY INTO NEPA. ADJUSTED OUR CURRENT HWO TO
REFLECT THIS THREAT ESPECIALLY ACROSS NEPA, WHICH IS CLOSE TO
WHAT SPC IS FORECASTING FOR SEVERE RISK.
BEYOND MONDAY NIGHT, THE PERIOD WILL BE DOMINATED BY A CLOSED
UPPER LOW JUST NORTH OF THE GREAT LAKES. GRADUALLY THROUGH THE
PERIOD WE WILL SEE PROGRESSIVELY COOLER AIR FILTER INTO THE AREA
ALONG WITH PERIODS OF SHOWERS. THIS WILL TRANSLATE INTO NEAR
NORMAL HIGHS TUESDAY (MID TO UPPER 50S) BUT THEN BELOW NORMAL
HIGHS BY WEDNESDAY. IN FACT SOME AREAS MAY NOT GET OUT OF THE 40S
FOR HIGHS WEDNESDAY AFTERNOON. THROUGH WEDNESDAY MOST AREAS WILL
SEE JUST RAIN SHOWERS. 850 TEMPS DO DROP BELOW ZERO BY WED MORNING
SO A STRAY FLAKE COULDN`T BE RULED OUT IN CNY EARLY IN THE DAY,
BUT THE APPRECIABLE COLDER AIR HOLDS OFF UNTIL WEDNESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE EXTENDED FORECAST WILL BE DOMINATED BY AN UPPER LEVEL LOW
WHICH SLOWLY MOVES FROM NEARBY SOUTHERN ONTARIO TO NOVA SCOTIA.
WILL CONTINUE TO ADVERTISE CHC/SLIGHT CHC POPS EACH DAY. BEST
CHANCES FOR SHOWERS WILL BE WED NIGHT WITH THE PASSAGE OF A SFC
OCCLUSION AND DURING THE DAYTIME PERIODS AS COLD POOL ALOFT AND
DIURNAL INSTABILITY WILL INCREASE COVERAGE. AIRMASS IS COLD ENOUGH
DURING THE OVERNIGHT PERIODS FOR A SNOW/RAIN SHOWER MIX. TEMPS
WILL RUN 5 TO 15 DEGREES BELOW NORMAL.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
00Z MON UPDATE... THE MOST SIG ISSUE THIS PD IS LIKELY TO BE THE
GUSTY SFC WINDS/PSBL LLWS...SPCLY LTR TNT AND MON MRNG. GIVEN AN
EXPECTED SE FLOW...KSYR/KITH/KBGM ARE LIKELY TO EXPERIENCE THE
STGST/MOST PERSISTENT GUSTS...WITH LOCAL TERRAIN EFFECTS (30-35
KT INDICATED). LLWS IS MORE LIKELY TO BE A CONCERN AT
KELM/KAVP...WITH MORE OF A WIND SPEED DIFFERENCE BETWEEN THE SFC
AND 2000 FEET AGL (PROJECTED WINDS AT THE 2000 FOOT LVL OF 50-60
KT).
VFR WILL CONTINUE FOR MUCH OF THE OVERNIGHT PD. SOME RESTRICTIONS
ARE PSBL MON MRNG...WHEN A BAND OF STEADIER RAIN IS EXPECTED TO
CROSS THE RGN. MVFR RESTRICTIONS ARE THE MOST LIKELY SCENARIO
(ROUGHLY 08-16Z)...WITH KRME/KBGM/KITH THE MOST PROBABLE SITES TO
BE IMPACTED.
FOR MOST OF MON AFTN...VFR SHOULD RETURN...AS A LULL IN PCPN IS
EXPECTED. LATE IN THE DAY (AFTER 21Z)...A LN OF SHWRS/PSBL TSTMS
COULD IMPACT KITH/KELM/KBGM/KAVP...WITH MVFR RESTRICTIONS AGN
PSBL. FOR THE TIME BEING...FCST RANGE (OUT NEARLY 24 HRS) AND
UNCERTAIN COVERAGE PRECLUDES MENTION OF THUNDER IN THE TERMINAL
FCSTS.
.OUTLOOK...
MON NIGHT-FRI...UNSETTLED PATTERN. RESTRICTIONS IN -SHRA...ESP
MON NGT.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
NEAR TERM...HEDEN
SHORT TERM...HEDEN
LONG TERM...RRM
AVIATION...MLJ/RRM
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
646 AM EDT SAT APR 18 2015
.SYNOPSIS...
WEAKENING LOW PRESSURE OFFSHORE AND AN APPROACHING DISTURBANCE
ALOFT FROM THE WEST WILL MAINTAIN SCATTERED SHOWERS TODAY. A WARM
FRONT WILL LIFT NORTH ACROSS THE AREA SUNDAY AND SUNDAY NIGHT
BRINGING WIDESPREAD SHOWERS AND THUNDERSTORMS. THIS WILL BE
FOLLOWED BY A COLD FRONT MONDAY NIGHT...WITH DRY AND SEASONABLE
HIGH PRESSURE TO FOLLOW THROUGH THE MIDDLE OF THE UPCOMING WEEK.
THIS HIGH PRESSURE WILL MOVE OFFSHORE THURSDAY BRINGING A RETURN
TO ABOVE NORMAL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM SATURDAY...THE ONLY TWEAKS TO THE FORECAST THIS
MORNING ARE TO INCREASE POPS TO 80-100 PERCENT ALONG AND EAST OF
I-95 FOR THE LARGE AREA OF RAIN AND EMBEDDED CONVECTIVE SHOWERS
MOVING EAST TOWARD THE COAST. LATEST HRRR AND HRRRX MODELS SHOW
THIS ACTIVITY MOVING OFF THE COAST BY 15Z-16Z (11 AM TO NOON) WITH
SCATTERED SHOWERS REDEVELOPING FARTHER INLAND FOR THE AFTERNOON.
DISCUSSION FROM 300 AM FOLLOWS...
A VERY NEBULOUS SURFACE PRESSURE PATTERN EXISTS ACROSS THE
CAROLINAS. WEAK LOW PRESSURE DEVELOPED A COUPLE DAYS AGO ALONG AN
OLD STALLED FRONT NEAR SAVANNAH. THIS LOW IS NOW DISSIPATING WELL
EAST OF THE SOUTH CAROLINA COAST DUE TO LACK OF BAROCLINICITY.
THIS WILL LEAVE VIRTUALLY NO SURFACE FEATURES OF NOTE
TODAY...LEAVING WINDS AT THE MERCY OF LOCAL EFFECTS LIKE THE
AFTERNOON SEABREEZE CIRCULATION PLUS ANY SHOWER OUTFLOW
BOUNDARIES.
AN UPPER LEVEL DISTURBANCE IS MOVING EASTWARD ACROSS THE CAROLINAS
THIS MORNING. THIS FEATURE SHOULD BRING GOOD CHANCES OF SHOWERS...
ESPECIALLY TO COASTAL SOUTH CAROLINA...WITH PRECIPITATION COVERAGE
EXPECTED TO DECREASE MARKEDLY IN THE FIRST FEW HOURS AFTER DAYBREAK.
STRONG APRIL SUNSHINE WILL CUT THROUGH THE REMAINING CLOUD COVER AND
HIGHS SHOULD STILL APPROACH 80 INLAND...WITH MID 70S NEAR THE COAST.
ALTHOUGH PRECIPITATION CHANCES MAY NOT INCREASE APPRECIABLY DURING
THE AFTERNOON AT THE COAST...TEMPS NEAR 80 SHOULD TRIGGER SCATTERED
SHOWERS INLAND WITH COVERAGE PROBABLY AROUND 30 PERCENT.
ANOTHER UPPER DISTURBANCE WILL APPROACH THE EASTERN CAROLINAS VERY
LATE TONIGHT FROM THE SOUTHWEST. HIGH PRESSURE OVER SE CANADA WILL
BEGIN TO BUILD DOWN THE EASTERN SEABOARD LATE TONIGHT AS WELL...WITH
A BACKDOOR COLD FRONT APPROACHING THE AREA FROM THE NORTHEAST AROUND
SUNRISE SUNDAY. LOWS SHOULD FALL INTO THE LOWER TO MIDDLE 60S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...STILL SHAPING UP TO BE A VERY WET PERIOD FOR
THE SHORT TERM AHEAD OF A COLD FRONT WHICH WILL CROSS THE AREA
MONDAY NIGHT.
SUNDAY WILL BEGIN DRY ACROSS MOST OF THE AREA...BUT THIS WILL
QUICKLY CHANGE AS A LOW PRESSURE SYSTEM BENEATH A POTENT SHORTWAVE
DEVELOPS AND MOVES OUT OF THE GULF STATES AND INTO THE OHIO VLY. A
WARM FRONT AHEAD OF THIS FEATURE WILL MOVE OVERHEAD THE
CAROLINAS...WITH A SECONDARY AREA OF LOW PRESSURE POSSIBLY
DEVELOPING OVERHEAD LATE SUNDAY NIGHT. DEEP SW FLOW WILL INTENSIFY
LATE SUNDAY...WITH 850MB V-WIND COMPONENT REACHING +3 SD`S LATE
SUNDAY NIGHT...SUPPORTING AN ENVIRONMENT OF POTENTIALLY RECORD-FOR-
THE-DAY PRECIPITABLE WATER AS COMPARED AGAINST THE SPC SOUNDING
CLIMATOLOGY. ALTHOUGH A NICE SUBTROPICAL JET WILL ARC ACROSS THE
MEXICO/US BORDER SUNDAY NIGHT...THIS WILL NOT AID IN ANY LIFT SO
UPPER SUPPORT LOOKS TO BE PRETTY WEAK INVOF THIS SYSTEM.
HOWEVER...SURFACE CONVERGENCE NEAR THE LOW PRESSURE COMBINED WITH
STRONG LOW-LEVEL MOISTURE TRANSPORT...WARM CLOUD DEPTH OF 11-12
KFT...AND ONLY WEAK INSTABILITY WHICH PROVIDES LONG PARCEL RESIDENCE
TIMES WITHIN THE SATURATED COLUMN...SUGGEST PERIODS OF HEAVY
RAINFALL WILL OCCUR...ESPECIALLY SUNDAY NIGHT. INSTABILITY LOOKS
PRETTY LIMITED SO THUNDER WILL BE ONLY ISOLATED...BUT HEAVY SHOWERS
PRODUCING WIDESPREAD 1" OF QPF OR MORE LOOKS VERY LIKELY INTO MONDAY
MORNING.
MUCH DRIER AIR WILL FILTER INTO THE REGION MONDAY...BUT CONTINUED
DEEP SW FLOW AND THE APPROACH OF A COLD FRONT WILL STILL CREATE THE
POTENTIAL FOR SCATTERED SHOWERS. BEST CHANCE WILL BE LATE MONDAY
INTO MONDAY NIGHT IMMEDIATELY AHEAD OF AND ALONG THE
BOUNDARY...WHICH IS PROGGED TO MOVE OFFSHORE BY THE END OF THE
PERIOD.
TEMPS THROUGH THE PERIOD WILL BE NORMAL-TO-ABOVE FOR MID-APRIL.
MONDAY WILL BE THE WARMER DAY WITH FEWER CLOUDS ALLOWING FOR MORE
INSOLATION TO WARM THE SURFACE. 850MB TEMPS BOTH DAYS WILL BE 12-
14C...BUT CLOUDS AND RAIN WILL KEEP HIGHS IN THE MID 70S
SUNDAY...WARMING INTO THE LOW 80S AWAY FROM THE COAST MONDAY. LOWS
SUNDAY NIGHT WILL STRUGGLE TO DROP ONLY INTO THE UPR 60S...LOW 60S
BEHIND THE FRONT MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...COLD FRONT WILL BE OFFSHORE TUESDAY
MORNING...AND A PRIMARILY QUIET WEEK LOOKS TO BE ON TAP FOR THE
EXTENDED. HIGH PRESSURE WILL MOVE ACROSS THE SOUTHERN TIER OF STATES
TUE-THU BEFORE PUSHING OFFSHORE LATE IN THE WEEK. THIS OCCURS IN
RESPONSE TO FORCED-ZONAL FLOW SOUTH OF A LARGE CLOSED LOW WHICH WILL
SIT AND SPIN ACROSS SE CANADA THROUGH MUCH OF THE WEEK. THE
CAROLINAS WILL BE ON THE PERIPHERY OF THIS FEATURE...SO WHILE COOLER
TEMPS WILL OCCUR TUE/WED...SEASONABLE VALUES ARE ANTICIPATED. LATE
IN THE PERIOD AS THE HIGH PUSHES OFFSHORE...MOIST RETURN FLOW WILL
DEVELOP AND SHOWER ACTIVITY WILL BECOME POSSIBLE ONCE AGAIN
THURSDAY...AND ESPECIALLY FRIDAY. FRIDAY WILL FEATURE THE BEST
CHANCES FOR PRECIP BOTH DUE TO INCREASED COLUMN MOISTURE...BUT ALSO
THANKS TO A COLD FRONT WHICH WILL APPROACH FROM THE NW...DRIVEN BY A
PIECE OF VORT ENERGY ROTATING AROUND THE AFOREMENTIONED LARGE UPPER
LOW. TEMPS THU/FRI WILL RETURN TO ABOVE NORMAL HOWEVER.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...A RATHER LARGE BATCH OF PRECIP IS CURRENTLY PASSING
THROUGH THE CWA FROM WEST TO EAST...ASSOCIATED WITH A SHORT WAVE.
LOOK FOR INTERMITTENT MVFR WITH POSSIBLE BRIEF IFR PERIODS IN THE
HEAVIER PRECIP. THE SHORTWAVE AND ASSOCIATED PRECIP WILL EXIT THE
REGION BY LATE MORNING...HOWEVER IT IS LIKELY THAT MVFR CEILINGS
WILL REMAIN FOR SOME TIME AFTER THAT. HIGH PRESSURE CENTERED TO OUR
NORTH WILL GIVE US LIGHT NORTHEAST FLOW TODAY. THROUGH THE EVENING
HOURS MAINLY A MID CLOUD CEILING WILL PREVAIL.
EXTENDED OUTLOOK...SHOWERS ACCOMPANIED WITH ISOLATED THUNDER TO
AFFECT THE FORECAST AREA LATE SUNDAY THROUGH MONDAY
MORNING...RESULTING IN OCCASIONAL MVFR AND IFR CONDITIONS. SCATTERED
PCPN ASSOCIATED WITH A CFP MONDAY NIGHT FOLLOWED BY MAINLY VFR
CONDITIONS TUE THROUGH WED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM SATURDAY...ADJUSTED FORECAST WIND DIRECTIONS 20-30
DEGREES COUNTERCLOCKWISE FOR THE NEXT 3-4 HOURS BASED ON CURRENT
OBSERVATIONS...OTHERWISE NO SIGNIFICANT CHANGES HAVE BEEN MADE TO
THE FORECAST. DISCUSSION FROM 300 AM FOLLOWS...
A VERY DISORGANIZED SURFACE WEATHER PATTERN EXISTS ACROSS THE
AREA. WEAK LOW PRESSURE THAT DEVELOPED A COUPLE DAYS AGO ALONG AN
OLD STATIONARY FRONT IS DISSIPATING OFF THE SOUTH CAROLINA COAST.
MORE IMPORTANT TO OUR WEATHER WILL BE THE PASSAGE OF AN UPPER
LEVEL DISTURBANCE THIS MORNING WHICH PROMISES TO BRING GOOD
CHANCES FOR SHOWERS. BEHIND THIS DISTURBANCE LOOK FOR PARTIAL
CLEARING AND A REDUCTION IN RAIN COVERAGE FOR THE AFTERNOON. BY
LATE TONIGHT THE APPROACH OF ANOTHER DISTURBANCE FROM THE
SOUTHWEST COULD BRING INCREASING SHOWER CHANCES IN AROUND
DAYBREAK.
VARIABLE WINDS TODAY SHOULD REMAIN 10 KNOTS OR LESS. SEAS AS HIGH AS
4 FEET IN THE 10-20 MILE OFFSHORE WATERS NEAR CAPE FEAR WILL SUBSIDE
THIS AFTERNOON...WITH 2-3 FEET SEAS EXPECTED FOR ALL AREAS. VERY
LATE TONIGHT HIGH PRESSURE OVER SE CANADA WILL PUSH A BACKDOOR FRONT
TOWARD THE AREA...WITH INCREASING NE WINDS EXPECTED AROUND DAYBREAK
SUNDAY.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...STRENGTHENING SOUTHERLY FLOW AHEAD OF A COLD
FRONT WILL PRODUCE GUSTY WINDS AND A POSSIBLE SHORT SCA SUNDAY NIGHT
INTO MONDAY. BEFORE THIS TIME...WINDS WILL VEER FROM E TO S THROUGH
SUNDAY AS HIGH PRESSURE MOVES OFF TO THE NE AND A WARM FRONT LIFTS
ACROSS THE WATERS. AS THE WINDS VEER THEY WILL INCREASE AS
WELL...BECOMING 15-20 KTS SUNDAY NIGHT INTO MONDAY...AND THESE WINDS
WILL PUSH SEAS UP TO 3-6 FT...HIGHEST ACROSS THE NC WATERS. A SHORT
DURATION SCA STILL LOOKS LIKELY AND IS HIGHLIGHTED IN THE HWO. WINDS
WILL SLOWLY VEER THROUGH MONDAY TO THE SW AT SIMILAR SPEEDS...BEFORE
THE COLD FRONT CROSSES THE WATERS AT THE END OF THE PERIOD WITH A
WIND SHIFT TO THE NW. SEAS MONDAY WILL BE 3-5 FT AHEAD OF THE COLD
FRONT...BEFORE FALLING AS THE WINDS TURN OFFSHORE LATE.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...HIGH PRESSURE MOVING ACROSS THE SOUTHERN
TIER OF THE NATION WILL DRIFT ACROSS THE WATERS DURING WEDNESDAY.
AHEAD OF THIS...LIGHT NW WINDS WILL OCCUR OVER THE WATERS...BECOMING
VARIABLE WEDNESDAY AS THE GRADIENT WEAKENS...AND EVENTUALLY TURNING
TO THE SW LATE...BUT STILL AT SPEEDS GENERALLY 10 KTS OR LESS. A
VERY BRIEF PERIOD OF 3-5 FT SEAS ARE POSSIBLE EARLY
TUESDAY...LEFTOVERS FROM THE MORE STRONGLY FORCED SEAS ON
MONDAY...BEFORE FALLING TO 2-3 FT AND PERSISTING THROUGH MID-WEEK.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...DL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
647 PM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 648 PM CDT SUN APR 19 2015
MAIN UPDATE EARLY THIS EVENING WAS TO BUMP UP SKY COVER TO BROKEN
ACROSS CENTRAL NORTH DAKOTA THROUGH MUCH OF THE EVENING. LATEST
SATELLITE IMAGERY SHOWS BROKEN VFR LAYER AROUND 7-9KFT ACROSS
CENTRAL NORTH DAKOTA...AND DIMINISHING TO A SCATTERED LAYER ACROSS
THE WEST. RAP/NAM FORECAST SOUNDINGS INDICATE A LITTLE INVERSION
HERE WITH MOISTURE UNDERNEATH AND IS SUPPORTED BY 00Z SOUNDING.
HAVE SLOWED THE CLEARING ACROSS THE CENTRAL THIS EVENING. SHOWERS
CONTINUE TO DISSIPATE AND HAVE LIMITED SHOWER MENTION TO ISOLATED
FROM THE HIGHWAY 83 CORRIDOR EASTWARD AND DISSIPATING FROM WEST
TO EAST DURING THE EVENING. OTHERWISE NO CHANGES TO THE GOING
FORECAST.
UPDATE ISSUED AT 502 PM CDT SUN APR 19 2015
QUICK UPDATED THIS AFTERNOON TO REMOVE MENTION OF SHOWERS WEST AND
THUNDER CENTRAL AND WEST. SHOWERS HAVE ALL BUT DISSIPATED ACROSS
THE WESTERN THIRD OF NORTH DAKOTA WITH DIMINISHING CLOUDS EXPECTED
FOR THE REMAINDER OF THE AFTERNOON. SHOWERS HAVE DECREASED IN
INTENSITY AND AREAL COVERAGE CENTRAL WITH NO LIGHTNING CG STRIKES
INDICATED YET. WITH DAYTIME HEATING ON THE WANE...WILL REMOVE
THUNDER CENTRAL AND GO WITH JUST ISOLATED TO SCATTERED SHOWERS.
OTHERWISE NO CHANGES EXCEPT TO UPDATED LATEST SENSIBLE WEATHER
ELEMENTS. WILL CONTINUE TO BE BREEZY TO WINDY THIS AFTERNOON.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 305 PM CDT SUN APR 19 2015
RAIN SHOWERS THIS AFTERNOON AND CRITICAL FIRE WEATHER CONDITIONS
MONDAY HIGHLIGHT THE SHORT TERM FORECAST.
SCATTERED SHOWERS ACROSS CENTRAL AND MUCH OF WESTERN NORTH DAKOTA
WILL CONTINUE THE REMAINDER OF THE AFTERNOON IN WRAP AROUND
MOISTURE BEHIND THE SURFACE LOW ACROSS MINNESOTA. HAVE HAD MANY
REPORTS OF SMALL HAIL UP TO PEA SIZE WITH THESE SHOWERS...AND HAVE
MAINTAINED AN ISOLATED THUNDERSTORM MENTION WITH LOW TOPPED
CONVECTION IN COLD TEMPERATURES ALOFT. THESE SHOWERS AND STORMS
ARE EXPECTED TO FOLLOW A DIURNAL PATTERN OF FADING WITH THE
APPROACH OF SUNSET. REGARDING CRITICAL FIRE WEATHER CONDITIONS
MONDAY...SEE THE FIRE WEATHER DISCUSSION BELOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 305 PM CDT SUN APR 19 2015
AN UPPER LOW WILL REMAIN JUST EAST OF NORTH DAKOTA THROUGH THE
EARLY PART OF THIS WEEK. MOST OF THE WIDESPREAD PRECIPITATION
ASSOCIATED WITH THE UPPER LEVEL LOW SHOULD REMAIN EAST OF US.
HOWEVER...NORTH DAKOTA WILL BE UNDER THE INFLUENCE OF A CURVED JET
AND BAROCLINIC ZONE. THIS COULD SPARK SOME ISOLATED TO SCATTERED
RAIN SHOWERS THROUGH TUESDAY. GUSTY NORTHWEST WINDS WILL CONTINUE
IN THE WAKE OF THE SYSTEM THROUGH TUESDAY. QUIET AND COOL
CONDITIONS ARE EXPECTED WITH RIDGING TO THE WEST AND
NORTHWESTERLY FLOW OVER THE AREA THROUGH THE REST OF THE WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 648 PM CDT SUN APR 19 2015
LOW PRESSURE OVER THE NORTHERN GREAT LAKES REGION WILL MOVE EAST
TONIGHT. VFR CEILINGS ACROSS CENTRAL NORTH DAKOTA IN THE WRAP
AROUND MOISTURE WILL SLOWLY DISSIPATE FROM WEST TO EAST TONIGHT
WITH MAINLY SCATTERED VFR CLOUDS EXPECTED ON MONDAY. HRRR DOES
SHOW ANOTHER LOBE OF MOISTURE DROPPING THROUGH CENTRAL NORTH
DAKOTA LATER TONIGHT WITH POSSIBLE MVFR CEILINGS. WILL MONITOR FOR
NOW BUT KEEP WITH VFR CEILINGS. NORTHWEST WINDS WILL DIMINISH THIS
EVENING BUT PICK UP AGAIN MONDAY WITH GUSTS TO AROUND 25 KTS WEST
AND POSSIBLY OVER 35 KNOTS CENTRAL AND EAST.
&&
.FIRE WEATHER...
ISSUED AT 305 PM CDT SUN APR 19 2015
DESPITE COOL TEMPERATURES IN THE UPPER 40S AND 50S...A DRY AND
WINDY DAY IS EXPECTED ACROSS ALL OF WESTERN AND CENTRAL NORTH
DAKOTA MONDAY WHICH WILL LEAD TO CRITICAL FIRE WEATHER CONDITIONS.
AFTERNOON RELATIVE HUMIDITY LEVELS WEST OF NORTH DAKOTA HIGHWAY 3
WILL FALL TO AS LOW AS 15 PERCENT WITH NORTHWEST WINDS OF 25 TO 35
MPH. TO THE EAST OF NORTH DAKOTA HIGHWAY 3 ACROSS THE TURTLE
MOUNTAINS THROUGH THE JAMES RIVER VALLEY...RELATIVE HUMIDITY
LEVELS NEAR 30 PERCENT ARE EXPECTED...WITH NORTHWEST WIND GUSTS
TO 40 MPH. GIVEN THE LACK OF SIGNIFICANT GREEN UP OF
VEGETATION...RAPID FIRE SPREAD IS EXPECTED WITH ANY FIRE START.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TO 10 PM CDT /9 PM
MDT/ MONDAY FOR NDZ001>005-009>013-017>023-025-031>037-040>048-
050-051.
&&
$$
UPDATE...TWH
SHORT TERM...AYD
LONG TERM...AJ
AVIATION...TWH
FIRE WEATHER...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
314 PM CDT SAT APR 18 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 315 PM CDT SAT APR 18 2015
RAINFALL POTENTIAL THROUGH TONIGHT HIGHLIGHTS THE SHORT TERM
FORECAST.
AS OF 1930 UTC...A COLD FRONT WAS JUST ENTERING NORTHWEST NORTH
DAKOTA AND WILL CONTINUE TO PROPAGATE THROUGH CENTRAL NORTH DAKOTA
THIS EVENING. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WITH
WEAK INSTABILITY HAVE DEVELOPED ALONG THIS FRONT AND WILL APPROACH
THE HIGHWAY 83 CORRIDOR BY 01-02 UTC. AS CYCLOGENESIS OCCURS
ACROSS EASTERN SOUTH DAKOTA THROUGH THE NIGHT AND THE NORTHERN STREAM
WAVE ASSOCIATED WITH THE COLD FRONT PHASES WITH THE LOW TO THE
SOUTH...RAINFALL COVERAGE WILL INCREASE ACROSS CENTRAL NORTH
DAKOTA THROUGH THE EVENING AND NIGHT. THEREAFTER...A WINDY SUNDAY
IS FORECAST IN THE WAKE OF THE NOW DEEPENING LOW ACROSS MINNESOTA.
AT THIS TIME...WIND GUSTS APPEAR TO STAY BELOW ADVISORY CRITERIA
WITH 30 TO 35 KTS TO MIX IN COLD AIR ADVECTION. SCATTERED LIGHT
RAIN SHOWERS ARE ALSO EXPECTED IN WRAP AROUND MOISTURE WITH
PERHAPS A FEW SNOWFLAKES MIXING IN SUNDAY MORNING AS TEMPERATURES
FALL INTO THE MID 30S NORTHWEST AND NORTH CENTRAL. GIVEN GOOD
AGREEMENT...WILL WEIGH HEAVILY ON THE 16-18 UTC HRRR ITERATIONS
BLENDED TO THE GLOBAL 12 UTC DETERMINISTIC AND ENSEMBLE SUITE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CDT SAT APR 18 2015
WINDY WITH SCATTERED SHOWERS TO BEGIN THE EXTENDED...COOL AND DRY
THROUGH THE REMAINDER OF THE WEEK.
AS THE MAIN SURFACE LOW ENTERS NORTHERN MINNESOTA AND SOUTHERN
CANADA...MOISTURE SHOULD WRAP AROUND THE BACKSIDE...PROVIDING
NORTH DAKOTA WITH SOME SCATTERED LIGHT RAIN. THE HIGH RESOLUTION
SHORT TERM MODELS ARE A LITTLE MORE ROBUST WITH PRECIPITATION
COVERAGE THAN THE GLOBAL MODELS (ECMWF/GFS). WITH THE LOW
REMAINING NEARBY AND REMAINING UNDER THE INFLUENCE OF A FAVORABLE
JET STREAK...LIGHT SHOWERS HERE AND THERE AREN`T OUT OF THE
QUESTION THROUGH TUESDAY. GUSTY WINDS ARE EXPECTED THOUGH THE DAY
SUNDAY AND MONDAY AS THE PRESSURE GRADIENT TIGHTENS WITH THE
SURFACE LOW DEEPENING AND PROPAGATING TOWARD THE GREAT LAKES.
THESE GUSTY NORTHWEST WINDS WILL BE ADVECTING DRIER AIR INTO THE
AREA. THIS COULD CREATE RATHER CRITICAL FIRE CONDITIONS MONDAY AS
RELATIVE HUMIDITY DROPS BELOW 20 PERCENT.
THROUGH THE REMAINDER OF THE WORK WEEK...UPPER LOW SLOWLY WORKS
OFF TO THE EAST KEEPING NORTH/NORTHWESTERLY FLOW OVER OUR AREA.
WITH THE EXCEPTION OF ISOLATED SHOWERS EARLY THIS WEEK...DRY
WEATHER IS EXPECTED. TEMPERATURES WILL REMAIN A BIT BELOW
AVERAGE WITH READINGS IN THE 50S FOR HIGHS AND 20S/30S FOR LOWS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 315 PM CDT SAT APR 18 2015
A COLD FRONT ACROSS WESTERN NORTH DAKOTA THIS AFTERNOON WILL
MOVE ACROSS THE CENTRAL THIS EVENING AND MERGE WITH A LOW
DEVELOPING ACROSS EASTERN SOUTH DAKOTA TONIGHT. SCATTERED RAIN
SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE ACROSS WESTERN
NORTH DAKOTA THIS AFTERNOON...WITH MORE WIDESPREAD RAIN SHOWERS
POSSIBLE AT KMOT/KBIS/KJMS THIS EVENING AND TONIGHT. EMBEDDED MVFR
CONDITIONS POSSIBLE IN RAIN.
&&
.FIRE WEATHER...
ISSUED AT 315 PM CDT SAT APR 18 2015
CRITICAL FIRE WEATHER CONDITIONS MAY BE POSSIBLE ON MONDAY...AND
THIS WILL NEED TO BE MONITORED. WHILE TEMPERATURES WILL ONLY BE IN
THE 50S...MINIMUM RELATIVE HUMIDITY LEVELS OF 15 TO 20 PERCENT AND
NORTHWEST WINDS OF 25 TO 35 MPH ARE POSSIBLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AYD
LONG TERM...AJ
AVIATION...AYD
FIRE WEATHER...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1230 PM CDT SAT APR 18 2015
.UPDATE...
ISSUED AT 1230 PM CDT SAT APR 18 2015
NO SIGNIFICANT CHANGES WITH THIS UPDATE AS THE 12 UTC
DETERMINISTIC SUITE AND 13-16 UTC HRRR ITERATIONS MATCH WELL TO
OBSERVED TRENDS THROUGH 17 UTC OF RAIN SLOWLY PROPAGATING NORTH
FROM SOUTH DAKOTA IN ASSOCIATION WITH THE UPPER LEVEL LOW AND
RAIN SHOWER ACTIVITY JUST BEGINNING ACROSS EASTERN MONTANA
ALONG THE COLD FRONT.
UPDATE ISSUED AT 920 AM CDT SAT APR 18 2015
WILL CONTINUE TO FAVOR THE TRENDS OF THE 10-13 UTC HRRR ITERATIONS
WHICH KEEP THE BAND OF PRECIPITATION ACROSS SOUTHERN SOUTH DAKOTA
AND EASTERN NEBRASKA IN ASSOCIATION WITH THE UPPER LEVEL LOW FOR
THE MOST PART TO THE SOUTH OF NORTH DAKOTA UNTIL 22-24 UTC THIS
EVENING GIVEN DRY EAST-SOUTHEASTERLY LOW LEVEL FLOW PRECEDING
THIS SYSTEM. BETTER CHANCES FOR SHOWER ACTIVITY THIS AFTERNOON ARE
ACROSS THE WEST AS A COLD FRONT ACROSS EASTERN MONTANA THIS
MORNING ENTERS WESTERN NORTH DAKOTA THIS AFTERNOON. DID ADD A
MENTION OF THUNDERSTORMS TO THE WEST ALONG THE FRONT WITH SOME
WEAK INSTABILITY DEPICTED ON THE 06 UTC NAM/GFS BUFR SOUNDINGS.
UPDATE ISSUED AT 626 AM CDT SAT APR 18 2015
A FEW WEAK RADAR ECHOS ARE TRYING TO SNEAK INTO THE SOUTH CENTRAL
PART OF THE STATE...THOUGH THESE APPEAR WEAK AND DOUBTFUL MORE THAN
A FEW SPRINKLES COULD BE HITTING THE GROUND. WITH THAT SAID...LATEST
GUIDANCE IS STILL ON TRACK FOR SHOWERS TO BE ON THE INCREASE LATE
DAY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 424 AM CDT SAT APR 18 2015
MARGINAL FIRE WEATHER CONDITIONS AND CHANCES FOR MUCH NEEDED
RAIN WILL HIGHLIGHT THE SHORT TERM.
AS TWO UPPER LEVEL LOWS CONVERGE OVER THE NORTHERN PLAINS THROUGH
SATURDAY...MOISTURE TRANSPORT FROM THE SOUTH AND ATMOSPHERIC
INSTABILITY WILL CREATE WIDESPREAD CHANCES FOR RAIN. SOUTHERN AND
EASTERN AREAS OF THE STATE ARE EXPECTED TO HAVE THE GREATEST CHANCES
FOR SUBSTANTIAL RAIN...CONCLUDED THROUGH GOOD AGREEMENT WITH THE
CURRENT 00Z MODEL SUITE. CHANCES FOR RAIN ARE FORECAST TO INITIATE
THROUGH SATURDAY AFTERNOON AND PERSIST INTO SUNDAY MORNING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 424 AM CDT SAT APR 18 2015
ON SUNDAY...DEEPENING TROUGH CLOSES OFF OVER MANITOBA WHILE LOW OVER
THE SOUTHERN PLAINS WASHES INTO THE NORTHERN SYSTEM. PRECIPITATION
CHANCES WILL CONTINUE PRIMARILY OVER CENTRAL AND NORTHERN NORTH
DAKOTA...THOUGH MOISTURE WRAPPING AROUND THE BACK SIDE OF THE SYSTEM
WILL STILL KEEP LOWER PRECIPITATION CHANCES FURTHER SOUTH AND WEST.
GUSTY WINDS EXPECTED THOUGH THE DAY IN TIGHT PRESSURE GRADIENT WITH
SURFACE LOW PUSHING INTO THE MIDWEST. WINDS WILL REMAIN BREEZY
OVERNIGHT WITH LOW RAIN/SNOW CHANCES LINGERING OVER CENTRAL NORTH
DAKOTA.
UPPER LOW PUSHES ALONG THE MINNESOTA/ONTARIO BORDER ON MONDAY. THIS
WILL KEEP LOW PRECIPITATION CHANCES GOING PRIMARILY OVER THE JAMES
RIVER VALLEY. WITH TIGHT PRESSURE GRADIENT ON THE BACK SIDE OF THIS
SYSTEM...WILL KEEP THE STRONGER WINDS MAINLY OVER CENTRAL NORTH
DAKOTA...DECREASING TOWARDS THE WEST.
THROUGH THE REMAINDER OF THE WORK WEEK...UPPER LOW SLOWLY WORKS OFF
TO THE EAST KEEPING NORTH/NORTHWESTERLY FLOW OVER OUR AREA. WITH THE
EXCEPTION OF A FEW SHOWERS POSSIBLE ON TUESDAY AS A FAST MOVING WAVE
SLIDES THROUGH THE FLOW...DRY WEATHER IS EXPECTED. TEMPERATURES WILL
REMAIN A BIT BELOW AVERAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1225 PM CDT SAT APR 18 2015
A COLD FRONT ACROSS EASTERN MONTANA THIS MORNING WILL ENTER
WESTERN NORTH DAKOTA THIS AFTERNOON AND MERGE WITH A LOW
DEVELOPING ACROSS EASTERN SOUTH DAKOTA TONIGHT. SCATTERED RAIN
SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE ACROSS WESTERN
NORTH DAKOTA THIS AFTERNOON...WITH MORE WIDESPREAD RAIN SHOWERS
POSSIBLE AT KMOT/KBIS/KJMS THIS EVENING AND TONIGHT. EMBEDDED MVFR
CONDITIONS POSSIBLE IN RAIN.
&&
.FIRE WEATHER...
ISSUED AT 424 AM CDT SAT APR 18 2015
RELATIVE HUMIDITY VALUES ARE PROJECTED TO BE IN THE LOWER TO MID
20S THIS AFTERNOON OVER CENTRAL NORTH DAKOTA. WITH SOUTHERLY WINDS
OF AROUND 10 TO 20 MPH...NEAR CRITICAL FIRE WEATHER CONDITIONS
WILL BE POSSIBLE. OVER WESTERN NORTH DAKOTA...A COLD FRONT WILL
PUSH INTO THE AREA BRINGING A WIND SHIFT TO THE NORTHWEST. BEHIND
THE FRONT...WINDS WILL INCREASE TO AROUND 25 MPH. RELATIVE
HUMIDITY VALUES WILL BE HIGHER OVER THIS REGION...INCREASING
BEHIND THE FRONT...THOUGH THIS STILL MAY BRING A PERIOD OF NEAR
CRITICAL FIRE WEATHER CONDITIONS. WETTING RAINS POSSIBLE
TONIGHT...ESPECIALLY OVER THE EASTERN HALF OF THE STATE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...AC
LONG TERM...JJS
AVIATION...AYD
FIRE WEATHER...AC/JJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
921 AM CDT SAT APR 18 2015
.UPDATE...
ISSUED AT 920 AM CDT SAT APR 18 2015
WILL CONTINUE TO FAVOR THE TRENDS OF THE 10-13 UTC HRRR ITERATIONS
WHICH KEEP THE BAND OF PRECIPITATION ACROSS SOUTHERN SOUTH DAKOTA
AND EASTERN NEBRASKA IN ASSOCIATION WITH THE UPPER LEVEL LOW FOR
THE MOST PART TO THE SOUTH OF NORTH DAKOTA UNTIL 22-24 UTC THIS
EVENING GIVEN DRY EAST-SOUTHEASTERLY LOW LEVEL FLOW PRECEDING
THIS SYSTEM. BETTER CHANCES FOR SHOWER ACTIVITY THIS AFTERNOON ARE
ACROSS THE WEST AS A COLD FRONT ACROSS EASTERN MONTANA THIS
MORNING ENTERS WESTERN NORTH DAKOTA THIS AFTERNOON. DID ADD A
MENTION OF THUNDERSTORMS TO THE WEST ALONG THE FRONT WITH SOME
WEAK INSTABILITY DEPICTED ON THE 06 UTC NAM/GFS BUFR SOUNDINGS.
UPDATE ISSUED AT 626 AM CDT SAT APR 18 2015
A FEW WEAK RADAR ECHOS ARE TRYING TO SNEAK INTO THE SOUTH CENTRAL
PART OF THE STATE...THOUGH THESE APPEAR WEAK AND DOUBTFUL MORE THAN
A FEW SPRINKLES COULD BE HITTING THE GROUND. WITH THAT SAID...LATEST
GUIDANCE IS STILL ON TRACK FOR SHOWERS TO BE ON THE INCREASE LATE
DAY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 424 AM CDT SAT APR 18 2015
MARGINAL FIRE WEATHER CONDITIONS AND CHANCES FOR MUCH NEEDED
RAIN WILL HIGHLIGHT THE SHORT TERM.
AS TWO UPPER LEVEL LOWS CONVERGE OVER THE NORTHERN PLAINS THROUGH
SATURDAY...MOISTURE TRANSPORT FROM THE SOUTH AND ATMOSPHERIC
INSTABILITY WILL CREATE WIDESPREAD CHANCES FOR RAIN. SOUTHERN AND
EASTERN AREAS OF THE STATE ARE EXPECTED TO HAVE THE GREATEST CHANCES
FOR SUBSTANTIAL RAIN...CONCLUDED THROUGH GOOD AGREEMENT WITH THE
CURRENT 00Z MODEL SUITE. CHANCES FOR RAIN ARE FORECAST TO INITIATE
THROUGH SATURDAY AFTERNOON AND PERSIST INTO SUNDAY MORNING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 424 AM CDT SAT APR 18 2015
ON SUNDAY...DEEPENING TROUGH CLOSES OFF OVER MANITOBA WHILE LOW OVER
THE SOUTHERN PLAINS WASHES INTO THE NORTHERN SYSTEM. PRECIPITATION
CHANCES WILL CONTINUE PRIMARILY OVER CENTRAL AND NORTHERN NORTH
DAKOTA...THOUGH MOISTURE WRAPPING AROUND THE BACK SIDE OF THE SYSTEM
WILL STILL KEEP LOWER PRECIPITATION CHANCES FURTHER SOUTH AND WEST.
GUSTY WINDS EXPECTED THOUGH THE DAY IN TIGHT PRESSURE GRADIENT WITH
SURFACE LOW PUSHING INTO THE MIDWEST. WINDS WILL REMAIN BREEZY
OVERNIGHT WITH LOW RAIN/SNOW CHANCES LINGERING OVER CENTRAL NORTH
DAKOTA.
UPPER LOW PUSHES ALONG THE MINNESOTA/ONTARIO BORDER ON MONDAY. THIS
WILL KEEP LOW PRECIPITATION CHANCES GOING PRIMARILY OVER THE JAMES
RIVER VALLEY. WITH TIGHT PRESSURE GRADIENT ON THE BACK SIDE OF THIS
SYSTEM...WILL KEEP THE STRONGER WINDS MAINLY OVER CENTRAL NORTH
DAKOTA...DECREASING TOWARDS THE WEST.
THROUGH THE REMAINDER OF THE WORK WEEK...UPPER LOW SLOWLY WORKS OFF
TO THE EAST KEEPING NORTH/NORTHWESTERLY FLOW OVER OUR AREA. WITH THE
EXCEPTION OF A FEW SHOWERS POSSIBLE ON TUESDAY AS A FAST MOVING WAVE
SLIDES THROUGH THE FLOW...DRY WEATHER IS EXPECTED. TEMPERATURES WILL
REMAIN A BIT BELOW AVERAGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 918 AM CDT SAT APR 18 2015
A COLD FRONT ACROSS EASTERN MONTANA THIS MORNING WILL ENTER
WESTERN NORTH DAKOTA THIS AFTERNOON AND MERGE WITH A LOW
DEVELOPING ACROSS EASTERN SOUTH DAKOTA TONIGHT. SCATTERED RAIN
SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE ACROSS WESTERN
NORTH DAKOTA THIS AFTERNOON...WITH MORE WIDESPREAD RAIN SHOWERS
POSSIBLE AT KMOT/KBIS/KJMS THIS EVENING AND TONIGHT. EMBEDDED MVFR
CONDITIONS POSSIBLE IN RAIN.
&&
.FIRE WEATHER...
ISSUED AT 424 AM CDT SAT APR 18 2015
RELATIVE HUMIDITY VALUES ARE PROJECTED TO BE IN THE LOWER TO MID
20S THIS AFTERNOON OVER CENTRAL NORTH DAKOTA. WITH SOUTHERLY WINDS
OF AROUND 10 TO 20 MPH...NEAR CRITICAL FIRE WEATHER CONDITIONS
WILL BE POSSIBLE. OVER WESTERN NORTH DAKOTA...A COLD FRONT WILL
PUSH INTO THE AREA BRINGING A WIND SHIFT TO THE NORTHWEST. BEHIND
THE FRONT...WINDS WILL INCREASE TO AROUND 25 MPH. RELATIVE
HUMIDITY VALUES WILL BE HIGHER OVER THIS REGION...INCREASING
BEHIND THE FRONT...THOUGH THIS STILL MAY BRING A PERIOD OF NEAR
CRITICAL FIRE WEATHER CONDITIONS. WETTING RAINS POSSIBLE
TONIGHT...ESPECIALLY OVER THE EASTERN HALF OF THE STATE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...AC
LONG TERM...JJS
AVIATION...AYD
FIRE WEATHER...AC/JJS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
800 PM EDT SUN APR 19 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTH FROM WESTERN KENTUCKY TO THE
CENTRAL GREAT LAKES TONIGHT AND PULL A WARM FRONT NORTH ACROSS
THE AREA. A COLD FRONT WILL SWEEP EAST ACROSS THE AREA ON MONDAY.
A COOL PATTERN WILL PERSIST THROUGH THE WEEK WITH INTERVALS OF
SHOWERS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPDATE...NAM12 AND RUC SHOW 925MB WINDS INCREASING TO 50 KNOTS OR
BETTER THROUGH THE EVENING AND HRRR AND NAM SHOW THIS CAUSING AN
INCREASE IS SURFACE WINDS WITH THE HIGHEST IMPACT OCCURRING IN A
CORRIDOR FROM MNN/MFD AREAS NNE TO THE CENTRAL LAKESHORE THROUGH
THE EVENING. THROUGH THE LATE EVENING THIS EXPANDS NORTHEAST
ACROSS THE REST OF THE LAKESHORE WHILE DIMINISHING A BIT BACK
ACROSS THE CENTRAL HIGHLANDS. SINCE PEAK GUSTS ARE ALREADY CLOSE
TO CRITERIA AT SEVERAL LOCATIONS FEEL THIS INCREASE WOULD CAUSE
MORE AREAS TO BE AT OR ABOVE CRITERIA.
ORIGINAL...LOW PRESSURE MAKING ITS WAY FROM WESTERN KENTUCKY
NORTH- NORTHEASTWARD. AN EXPANSIVE AREA OF RAIN/SHOWERS IS
ADVANCING NORTHWARD AND HAS REACHED MOUNT VERNON...MARION...AND
FINDLAY. SO FAR LIGHTNING HAS BEEN NIL AND HAVE NO MENTION OF
THUNDER. WILL CONTINUE TO BE STABLE WITH LIMITED LAPSE RATES.
OTHER THAN THE RAIN...WINDS WILL REMAIN GUSTY THROUGH THE NIGHT.
IN FACT THE DOWNSLOPE WIND FOR ERIE PA IS EXPECTED TO SURPASS WIND
ADVISORY CRITERIA. THE MOST CRITICAL TIME IS BETWEEN MIDNIGHT AND
4 AM. WITHOUT THE ADDED EFFECT OF THE DOWNSLOPE...GUSTS FOR OTHERS
WILL BE DAMPENED BY THE SHOWERS. TEMPERATURES TONIGHT WILL BE MILD
IN THE 50S. LOWS FOR THE TOLEDO AREA AND OTHERS ALONG THE
IMMEDIATE LAKESHORE TRICKY. THESE LOCATIONS WERE LEFT OUT OF THE
SUMMER LIKE 70S TODAY WITH A WIND OFF OF THE LAKE AND TEMPERATURES
THAT DID NOT GET OUT OF THE 50S. WINDS WILL EVENTUALLY COME AROUND
TO THE SOUTHEAST TONIGHT. SO WILL GO WITH A LOW THAT IS ACTUALLY A
FEW DEGREES WARMER THAN THEIR LATE AFTERNOON TEMPS. THE SAME GOES
FOR ERIE PA.
A LULL IS EXPECTED IN THE RAIN LATER TONIGHT AS A MID LEVEL DRY
SLOT ARRIVES...ALTHOUGH AN ISOLATED SHOWER IS STILL POSSIBLE AT
ANY TIME. THE TIMING OF THE NEXT ROUND OF ENHANCED PRECIPITATION
CHANCES MAY ARRIVE JUST BEFORE MORNING FOR FINDLAY/MARION. THUNDER
MAY ACCOMPANY THESE SHOWERS...BUT HAVE NOT PUT ANY MENTION IN THE
TONIGHT PORTION OF THE FORECAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
WILL HAVE TO CONTEND WITH THE ADVANCING COLD FRONT FOR
MONDAY...ALONG WITH VIGOROUS DYNAMICS ALOFT. THE DEGREE OF
INSTABILITY IN THE WARM SECTOR WILL DICTATE THE POTENTIAL
STRENGTH OF THUNDERSTORMS. THE AREA THAT HAS THE BEST CHANCES IS
ACROSS EASTERN OH AND POSSIBLY INTO NW PA. HAVE RAISED PRECIP
CHANCE FOR MONDAY. WILL STICK FAIRLY CLOSE TO GUIDANCE TEMPS FOR
MONDAY...WITH TEMPS IN THE 60S AND POSSIBLY TOUCHING 70 ACROSS THE
EAST.
SHOWERS/THUNDERSTORMS EXIT WITH THE PASSAGE OF THE COLD FRONT BY
MONDAY EVENING. THE PATTERN THROUGH MID WEEK WILL FEATURE A
STAGNANT UPPER LOW FIXATED OVER THE NORTHERN LAKES/CANADA. COLD
ADVECTION...ALTHOUGH AT A SLOW RATE...CONTINUES SOME EACH DAY.
TEMPERATURES WILL STRUGGLE TO REACH 60 TUESDAY...AND THEN STRUGGLE
EVEN MORE WEDNESDAY. WITH THE CYCLONIC FLOW AND STEEP LAPSE RATES...ANY
IMPULSE WORKING ITS WAY AROUND THE UPPER LOW WILL GENERATE
SHOWERS. WHILE THERE IS STILL TIMING DIFFERENCES...IT APPEARS ONE
OF THESE IMPULSES MAY MOVE ACROSS THE AREA BOTH TUESDAY AND
WEDNESDAY. WITH THE WEDNESDAY IMPULSE LOOKING A LITTLE
STRONGER...HAVE INCREASED PRECIP CHANCES SOME. BY WEDNESDAY NIGHT
H8 TEMPS ARE REACHING -5C AND THAT MAY ADD A FEW LAKE EFFECT RAIN
SHOWERS TO THE MIX. IT WILL REMAIN ON THE BREEZY SIDE WITH WEST-
SOUTHWEST FLOW AND A RELATIVELY TIGHT GRADIENT PERSISTING INTO MID
WEEK.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
BELOW NORMAL TEMPERATURES ARE EXPECTED THROUGH THE LONG TERM
FORECAST AS UPPER LEVEL LOW PRESSURE TAKES UP RESIDENCE. THIS LOW
WILL WOBBLE ACROSS THE REGION WITH EACH PIECE OF JET ENERGY THAT
ROTATES AROUND THE BASE OF IT. THIS WILL BE THE PERIODS OF TIME
WHERE PRECIPITATION WILL HAVE AN UPTICK. ALL LOCATIONS WILL HAVE A
CHANCE OF A PASSING SHOWER OR TWO EACH AFTERNOON. HOWEVER THE BEST
CHANCES OF SEEING THE RAIN/SNOW SHOWERS WILL BE ACROSS NE OHIO INTO
NW PA. ANY SNOW SHOWERS WILL BE LIMITED TO THE OVERNIGHT AND EARLY
MORNING HOURS.
HIGH TEMPERATURES WILL GENERALLY BE IN THE 50S THROUGH THE PERIOD.
WE WILL NEED TO MONITOR LOW TEMPERATURES CLOSELY THROUGH THE LONG
TERM. IF CLOUD COVER DECREASES MORE THAN ANTICIPATED THERE COULD BE
SOME PATCHY FROST.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
LARGE AREA OF RAIN MOVING NORTH ACROSS THE AREA AT THIS TIME. MAIN
BAND SHOULD BE QUICK TO LIFT THROUGH THE REGION WITH SCATTERED
ACTIVITY LATER TONIGHT. SOME THUNDER ACTIVITY BEING REPORTED WELL
SOUTH OF THE AREA BUT WILL LEAVE MENTION OUT OF THE TAFS SINCE
CONFIDENCE IS LOW AT THIS TIME. MVFR TO IFR CONDITIONS EXPECTED
OVERNIGHT AND THEN GRADUAL IMPROVEMENT TOMORROW ESPECIALLY AFTER
COLD FRONTAL PASSAGE. WINDS WILL BE THE BIG PROBLEM OVERNIGHT WITH
GUSTS PUSHING 40 KNOTS AT THE SURFACE OVER THE NEXT SEVERAL HOURS.
EXPECTING WINDS TO DIMINISH SOMEWHAT ONCE WIND SHIFTS TO MORE
SOUTHERLY. WIND SHEAR IS MARGINAL BUT EXPECTING WINDS TO REACH 45
KNOTS AT 1000 FEET AND MAY CAUSE SOME PROBLEMS SO DECIDED TO
INCLUDE IN THE TAFS.
.OUTLOOK...NON VFR AT TIMES MONDAY EVENING AND THEN MAINLY VFR.
&&
.MARINE...
LOW PRESSURE WILL MOVE THROUGH THE CENTRAL GREAT LAKES TONIGHT
LIFTING A WARM FRONT ACROSS THE LAKE. AHEAD OF THE WARM FRONT EAST
TO SOUTHEAST WINDS HAVE BEEN IN THE 15 TO 25 KNOT RANGE WHICH IS
HIGH ENOUGH TO HOIST A SMALL CRAFT ADVISORY. WILL KEEP THESE IN
THEIR CURRENT CONFIGURATION. HOWEVER THE UPPER LEVEL LOW WILL
PERSIST OVER THE CENTRAL GREAT LAKES THROUGH THE WEEK. AS A COUPLE
PIECES OF JET ENERGY ROTATE AROUND THE BASE OF THIS LOW WE EXPECT
WESTERLY WINDS TO REMAIN ELEVATED. IN ALL LIKELIHOOD THE EASTERN
HALF OF LAKE ERIE WILL SEE SMALL CRAFT ADVISORIES CONTINUE INTO
WEDNESDAY. WILL LET LATER SHIFTS PINPOINT THIS A BIT MORE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 6 AM EDT MONDAY FOR OHZ008>014-017>021-
027>031-036>038-047-089.
PA...WIND ADVISORY UNTIL 6 AM EDT MONDAY FOR PAZ001-002.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT MONDAY FOR LEZ148-149.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ142>147.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...TK/OUDEMAN
SHORT TERM...OUDEMAN
LONG TERM...MULLEN
AVIATION...LOMBARDY
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
753 PM EDT SUN APR 19 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTH FROM WESTERN KENTUCKY TO THE
CENTRAL GREAT LAKES TONIGHT AND PULL A WARM FRONT NORTH ACROSS
THE AREA. A COLD FRONT WILL SWEEP EAST ACROSS THE AREA ON MONDAY.
A COOL PATTERN WILL PERSIST THROUGH THE WEEK WITH INTERVALS OF
SHOWERS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPDATE...NAM12 AND RUC SHOW 925MB WINDS INCREASING TO 50 KNOTS OR
BETTER THROUGH THE EVENING AND HRRR AND NAM SHOW THIS CAUSING AN
INCREASE IS SURFACE WINDS WITH THE HIGHEST IMPACT OCCURRING IN A
CORRIDOR FROM MNN/MFD AREAS NNE TO THE CENTRAL LAKESHORE THROUGH
THE EVENING. THROUGH THE LATE EVENING THIS EXPANDS NORTHEAST
ACROSS THE REST OF THE LAKESHORE WHILE DIMINISHING A BIT BACK
ACROSS THE CENTRAL HIGHLANDS. SINCE PEAK GUSTS ARE ALREADY CLOSE
TO CRITERIA AT SEVERAL LOCATIONS FEEL THIS INCREASE WOULD CAUSE
MORE AREAS TO BE AT OR ABOVE CRITERIA.
ORIGINAL...LOW PRESSURE MAKING ITS WAY FROM WESTERN KENTUCKY
NORTH- NORTHEASTWARD. AN EXPANSIVE AREA OF RAIN/SHOWERS IS
ADVANCING NORTHWARD AND HAS REACHED MOUNT VERNON...MARION...AND
FINDLAY. SO FAR LIGHTNING HAS BEEN NIL AND HAVE NO MENTION OF
THUNDER. WILL CONTINUE TO BE STABLE WITH LIMITED LAPSE RATES.
OTHER THAN THE RAIN...WINDS WILL REMAIN GUSTY THROUGH THE NIGHT.
IN FACT THE DOWNSLOPE WIND FOR ERIE PA IS EXPECTED TO SURPASS WIND
ADVISORY CRITERIA. THE MOST CRITICAL TIME IS BETWEEN MIDNIGHT AND
4 AM. WITHOUT THE ADDED EFFECT OF THE DOWNSLOPE...GUSTS FOR OTHERS
WILL BE DAMPENED BY THE SHOWERS. TEMPERATURES TONIGHT WILL BE MILD
IN THE 50S. LOWS FOR THE TOLEDO AREA AND OTHERS ALONG THE
IMMEDIATE LAKESHORE TRICKY. THESE LOCATIONS WERE LEFT OUT OF THE
SUMMER LIKE 70S TODAY WITH A WIND OFF OF THE LAKE AND TEMPERATURES
THAT DID NOT GET OUT OF THE 50S. WINDS WILL EVENTUALLY COME AROUND
TO THE SOUTHEAST TONIGHT. SO WILL GO WITH A LOW THAT IS ACTUALLY A
FEW DEGREES WARMER THAN THEIR LATE AFTERNOON TEMPS. THE SAME GOES
FOR ERIE PA.
A LULL IS EXPECTED IN THE RAIN LATER TONIGHT AS A MID LEVEL DRY
SLOT ARRIVES...ALTHOUGH AN ISOLATED SHOWER IS STILL POSSIBLE AT
ANY TIME. THE TIMING OF THE NEXT ROUND OF ENHANCED PRECIPITATION
CHANCES MAY ARRIVE JUST BEFORE MORNING FOR FINDLAY/MARION. THUNDER
MAY ACCOMPANY THESE SHOWERS...BUT HAVE NOT PUT ANY MENTION IN THE
TONIGHT PORTION OF THE FORECAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
WILL HAVE TO CONTEND WITH THE ADVANCING COLD FRONT FOR
MONDAY...ALONG WITH VIGOROUS DYNAMICS ALOFT. THE DEGREE OF
INSTABILITY IN THE WARM SECTOR WILL DICTATE THE POTENTIAL
STRENGTH OF THUNDERSTORMS. THE AREA THAT HAS THE BEST CHANCES IS
ACROSS EASTERN OH AND POSSIBLY INTO NW PA. HAVE RAISED PRECIP
CHANCE FOR MONDAY. WILL STICK FAIRLY CLOSE TO GUIDANCE TEMPS FOR
MONDAY...WITH TEMPS IN THE 60S AND POSSIBLY TOUCHING 70 ACROSS THE
EAST.
SHOWERS/THUNDERSTORMS EXIT WITH THE PASSAGE OF THE COLD FRONT BY
MONDAY EVENING. THE PATTERN THROUGH MID WEEK WILL FEATURE A
STAGNANT UPPER LOW FIXATED OVER THE NORTHERN LAKES/CANADA. COLD
ADVECTION...ALTHOUGH AT A SLOW RATE...CONTINUES SOME EACH DAY.
TEMPERATURES WILL STRUGGLE TO REACH 60 TUESDAY...AND THEN STRUGGLE
EVEN MORE WEDNESDAY. WITH THE CYCLONIC FLOW AND STEEP LAPSE RATES...ANY
IMPULSE WORKING ITS WAY AROUND THE UPPER LOW WILL GENERATE
SHOWERS. WHILE THERE IS STILL TIMING DIFFERENCES...IT APPEARS ONE
OF THESE IMPULSES MAY MOVE ACROSS THE AREA BOTH TUESDAY AND
WEDNESDAY. WITH THE WEDNESDAY IMPULSE LOOKING A LITTLE
STRONGER...HAVE INCREASED PRECIP CHANCES SOME. BY WEDNESDAY NIGHT
H8 TEMPS ARE REACHING -5C AND THAT MAY ADD A FEW LAKE EFFECT RAIN
SHOWERS TO THE MIX. IT WILL REMAIN ON THE BREEZY SIDE WITH WEST-
SOUTHWEST FLOW AND A RELATIVELY TIGHT GRADIENT PERSISTING INTO MID
WEEK.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
BELOW NORMAL TEMPERATURES ARE EXPECTED THROUGH THE LONG TERM
FORECAST AS UPPER LEVEL LOW PRESSURE TAKES UP RESIDENCE. THIS LOW
WILL WOBBLE ACROSS THE REGION WITH EACH PIECE OF JET ENERGY THAT
ROTATES AROUND THE BASE OF IT. THIS WILL BE THE PERIODS OF TIME
WHERE PRECIPITATION WILL HAVE AN UPTICK. ALL LOCATIONS WILL HAVE A
CHANCE OF A PASSING SHOWER OR TWO EACH AFTERNOON. HOWEVER THE BEST
CHANCES OF SEEING THE RAIN/SNOW SHOWERS WILL BE ACROSS NE OHIO INTO
NW PA. ANY SNOW SHOWERS WILL BE LIMITED TO THE OVERNIGHT AND EARLY
MORNING HOURS.
HIGH TEMPERATURES WILL GENERALLY BE IN THE 50S THROUGH THE PERIOD.
WE WILL NEED TO MONITOR LOW TEMPERATURES CLOSELY THROUGH THE LONG
TERM. IF CLOUD COVER DECREASES MORE THAN ANTICIPATED THERE COULD BE
SOME PATCHY FROST.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
SOUTHEAST WINDS WILL BE BREEZY TO WINDY THROUGH THE 06Z. STRONGEST
WINDS WILL LIKELY BE NEAR KERI WITH A FEW GUSTS AROUND 40 KNOTS
POSSIBLE. REGION IS NOW AWAITING THE ARRIVAL OF THE SHOWERS THAT
ARE CURRENTLY (1745Z) MOVING INTO CENTRAL OHIO. THESE WILL BE ON
THE LIGHT SIDE UNTIL THE LOWER LEVELS OF THE ATMOSPHERE CAN
SATURATE. THIS WILL MEAN GRADUALLY LOWERING CEILINGS INTO THE
EVENING. AT THIS POINT IT APPEARS THE MVFR CEILINGS AND
VISIBILITIES WILL NOT ARRIVE UNTIL THE SHOWERS HAVE PERSISTED FOR
AN HOUR OR TWO. THE MVFR CEILINGS SHOULD THEN REMAIN UNTIL WINDS
SHIFT AROUND TO THE SOUTH. AS THE SOUTHERLY WINDS ARRIVE CEILINGS
WILL LIFT BACK TO VFR LEVELS. THE HEAVIEST RAINFALL SHOULD BE NEAR
AND WEST OF A LINE FROM SANDUSKY TO KMFD TO K4I3.
DO NOT FEEL CONFIDENT IN THE THUNDER CHANCES OVERNIGHT. IF THUNDER
CAN OCCUR IT WILL BE NEAR KFDY AND KTOL.
.OUTLOOK..NON VFR AT TIMES MONDAY AND MONDAY EVENING AND THEN
MAINLY VFR.
&&
.MARINE...
LOW PRESSURE WILL MOVE THROUGH THE CENTRAL GREAT LAKES TONIGHT
LIFTING A WARM FRONT ACROSS THE LAKE. AHEAD OF THE WARM FRONT EAST
TO SOUTHEAST WINDS HAVE BEEN IN THE 15 TO 25 KNOT RANGE WHICH IS
HIGH ENOUGH TO HOIST A SMALL CRAFT ADVISORY. WILL KEEP THESE IN
THEIR CURRENT CONFIGURATION. HOWEVER THE UPPER LEVEL LOW WILL
PERSIST OVER THE CENTRAL GREAT LAKES THROUGH THE WEEK. AS A COUPLE
PIECES OF JET ENERGY ROTATE AROUND THE BASE OF THIS LOW WE EXPECT
WESTERLY WINDS TO REMAIN ELEVATED. IN ALL LIKELIHOOD THE EASTERN
HALF OF LAKE ERIE WILL SEE SMALL CRAFT ADVISORIES CONTINUE INTO
WEDNESDAY. WILL LET LATER SHIFTS PINPOINT THIS A BIT MORE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 6 AM EDT MONDAY FOR OHZ008>014-017>021-
027>031-036>038-047-089.
PA...WIND ADVISORY UNTIL 6 AM EDT MONDAY FOR PAZ001-002.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT MONDAY FOR LEZ148-149.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ142>147.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...TK/OUDEMAN
SHORT TERM...OUDEMAN
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
733 PM EDT SUN APR 19 2015
.SYNOPSIS...
SOUTHEAST FLOW BREAKS DOWN OVERNIGHT...ALLOWING MORE HUMID/UNSTABLE
AIR TO CREEP FURTHER EAST. COLD FRONT MONDAY WITH SHOWERS AND
STORMS...FOLLOWED BY AN EXTENDED PERIOD OF COOLER AND DRIER WEATHER.
&&
.NEAR TERM /THROUGH MONDAY/...
720 PM UPDATE...UPDATED POPS BASED ON RECENT HRRR RUNS...WHICH
SEEM TO HAVE A FAIR HANDLE ON THE LINE OF SHOWERS AND STORMS
STRETCHING FROM CINCINNATI OH TO CHATTANOOGA TN. ADDED A LINE OF
LIKELY POPS LATE THIS EVENING INTO TONIGHT MOVING NE ACROSS CWA.
MAY GET SOME RUMBLES OF THUNDER AS WELL..MAINLY IN THE OHIO RIVER
VALLEY...CLOSER TO THE VORT MAX THAT STAYS TO OUR WEST. HAVE NOT
SEEN ANY GAUGES IN CWA WITH MORE THAN A QUARTER INCH STORM TOTAL
YET...AND SHOWERS TONIGHT SHOULD BE PROGRESSIVE WITH FAST FLOW
ABOVE THE SURFACE...LIMITING ANY WIDESPREAD WATER CONCERNS.
PREVIOUS DISCUSSION...
LIGHT RAIN CONTINUES ACROSS THE AREA.
HAVE BEEN WRESTLING WITH THE POTENTIAL FOR HEAVY RAIN THROUGH THE
TONIGHT PERIOD GIVEN THE FAST FLOWS THROUGH THE LOW LEVELS AND THE
HIGH PRECIPITATION EFFICIENCY. HOWEVER...CONVECTION ONGOING ACROSS
THE DEEP SOUTH CONTINUES TO THROW HIGH LEVEL CLOUDS INTO THE AREA
WITH AFOREMENTIONED LIGHT RAIN. SO...THERMODYNAMICALLY
SPEAKING...NOT GETTING THE DEEPER CONVECTION THAT MIGHT OTHERWISE
BE POSSIBLE. ALSO ASSISTING IN THE SUPPRESSION IS THE STRONG
SOUTHEASTERLY FLOW...PROVIDING SOME LOW LEVEL DRYING THAT HAS
LARGELY CUT OFF THE INSTABILITY ACROSS THE CWA.
THE EASTERN SLOPES STILL HAVE THE CHANCE FOR THE HIGHER
PRECIPITATION AMOUNTS...BUT WILL KEEP ANY FLOOD WATCHES OUT OF THE
FORECAST FOR NOW. RAINFALL RATES JUST ARE NOT THERE...BUT THIS
WILL NEED TO BE MONITORED.
OVER TOWARDS THE WESTERN CWA/TRI STATE AREA...THIS IS WHERE SOME
CONVECTION WOULD BE POSSIBLE THROUGH TONIGHT...AS THIS AREA LIES
ON THE WESTERN FRINGE OF THE CIRRUS COMING UP FROM THE SOUTHERN
CONVECTION. THERE IS SOME CLEARING RIGHT NOW OVER CENTRAL KENTUCKY
AND TENNESSEE WHICH WOULD ALLOW FOR SOME STORMS TO ORGANIZE...AND
WITH THE 0-6KM BULK SHEAR SOUTHWESTERLY...THIS WOULD STEER IT
TOWARDS THIS PARTICULAR AREA. VISIBLE SATELLITE IMAGE IS SHOWING
SOME ENHANCEMENT HERE...AND SPC HAS RECENTLY ISSUED A MESOSCALE
DISCUSSION FOR THIS AREA.
INTO LATE TONIGHT AND MONDAY...THE COLD FRONT SWINGS THROUGH AFTER
09Z. HEATING WILL HELP WITH THE CONVECTION WITH THE FRONT...AND
HAVE HIGHER POPS AND HIGHER CHANCES FOR THUNDER BASED ON SURFACE
INSTABILITY AFTER 12Z AND IN THE EASTERN CWA. SPC HAS A SLIGHT
CHANCE RISK FOR SEVERE IN THE NORTHEASTERN THIRD OF THE CWA.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
EASTERN CANADIAN UPPER LOW WILL BE THE CONTROLLING FEATURE THIS
PERIOD. SHOWERS WILL END EARLY MONDAY NIGHT AS THE COLD FRONT EXITS
TO THE EAST. WEAK UPPER DISTURBANCES ROTATING AROUND THIS UPPER LOW
WILL BRING REINFORCING SHOTS OF COOLER AIR TUESDAY NIGHT AND
WEDNESDAY...SO A SHOWER IS POSSIBLE TUESDAY NIGHT AND WEDNESDAY.
BELOW NORMAL TEMPERATURES WILL BE THE RULE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THANKFULLY...THE DRIER AND COOLER PATTERN APPEARS TO CONTINUE.
WITH TROFS OFF NORTHWEST COAST AND OVER NEW ENGLAND AND NORTHEAST
COAST. THE LACK OF DEEPER MOISTURE IS CERTAINLY WELCOMED.
STILL FAST MOVING MID LEVEL DISTURBANCES IN THE WNW STEERING FLOW
THAT CAUSES PROBLEMS HERE WITH DETERMINISTIC POPS HERE.
WAS DRIER FOR THE START OF THIS LONG TERM...THINKING WEDNESDAY`S
WEAK SYSTEM WILL BE EXITING WEDNESDAY EVENING. MEDIUM RANGE GUIDANCE
FROM WPC INTRODUCED LKLY POPS SATURDAY...BUT WILL HAVE JUST CHANCE
POPS WORKING NORTH SATURDAY. CONFIDENCE IN TIMING SOUTHERN MOISTURE
MOVING NORTH IS LOW.
STRATOCUMULUS CLOUD IN THE COOLER FLOW AND WIND LIKELY TO MESS
WITH OUR FORECAST LOW TEMPERATURES...BUT HAVE 30S AND LOWER 40S FOR
SEVERAL NIGHTS...FOR DAWN FRIDAY...SATURDAY...AND SUNDAY.
&&
.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
CURRENT GUSTY SOUTHEAST WINDS A GRADUALLY DIMINISHING THIS
EVENING...AND TURN MORE SOUTHERLY LATER TONIGHT. HAVE AN AREA OF
RAIN ACROSS THE EASTERN CWA...WITH SOME MVFR POSSIBLE. ALSO EXPECT
MVFR CIGS ON EASTERN SLOPES. NOT ENTIRELY SURE WHY BKW HAS NOT
ALREADY GOTTEN THIS...SO CONFIDENCE IS LOWERED A BIT. ALSO HAVE A
LINE OF SHOWERS TO OUR WEST WHICH WILL MOVE THROUGH THIS
EVENING...EXPECT THEM TO WEAKEN SO DID NOT INCLUDE ANY MVFR OR
IFR...BUT MAY NEED TO CHANGE THAT BASED ON TRENDS OVER THE NEXT
COUPLE HOURS. DID NOT INCLUDE MUCH FOG TONIGHT WITH FLOW
REMAINING...BUT AFTER ANY SHOWER COULD SEE SOME BRIEF FOG.
A COLD FRONT WILL MOVE THROUGH TOMORROW WITH THE POTENTIAL OF
SHOWERS AND THUNDERSTORMS. THIS WILL ALSO CAUSE WINDS TO BECOME
MORE WESTERLY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: BRIEF IFR POSSIBLE IN HEAVY RAIN...BUT SHOULD
NOT LAST LONG. TIMING OF PRECIPITATION BEGINNING/END MAY VARY.
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 20 21 22 23 00 01 02 03 04 05 06 07
EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H M
EKN CONSISTENCY H H H M M M H H H H H H
PKB CONSISTENCY M M M H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 00Z TUESDAY...
IFR POSSIBLE MONDAY IN SHOWERS AND THUNDERSTORMS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/JMV/26
NEAR TERM...MZ/26
SHORT TERM...JMV
LONG TERM...KTB
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS NORMAN OK6
1150 AM CDT SAT APR 18 2015
.AVIATION...
EXPECT VFR CEILINGS THROUGH THE AFTN WITH A ROUND OF
TSTMS TO AFFECT MOST TAF SITES LATE THIS AFTN INTO THIS EVENING. A
COLD FRONT WILL BRING A WIND SHIFT FROM NW TO SE OVERNIGHT INTO
SUNDAY MORNING. SOME GUSTS TO NEAR 30KTS POSSIBLE IN NORTHWEST OK.
30
&&
.PREV DISCUSSION... /ISSUED 646 AM CDT SAT APR 18 2015/
.DISCUSSION...
AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW.
&&
.AVIATION...
HAVE LOW CONFIDENCE OF VFR TO LIFR CONDITIONS IN WESTERN OKLAHOMA
THROUGH 21Z AS WELL AS LOW CONFIDENCE WITH TSRA TIMING/COVERAGE
AFTER 19Z.
CONDITIONS WILL BOUNCE BETWEEN VFR AND LIFR WITH BR/FG ACROSS
WESTERN OKLAHOMA THROUGH 21Z. THE WORST CONDITIONS MAY BE NEAR
KCSM AND KHBR THROUGH 15Z. IFR CONDITIONS MAY AFFECT KSPS AND KLAW
AS WELL THROUGH 15Z...BUT DID NOT MENTION THINKING THESE LOWER
CONDITIONS WILL STAY WEST OF THESE SITES.
HAVE HIGH CONFIDENCE ALL SITES WILL BE VFR BY 21Z.
ISO-NUM TSRA WILL FORM AND AFFECT MANY TAF SITES AFTER 19Z. USED
VCTS/TEMPOS AT MOST SITES EXCEPT KCSM AND KHBR WHERE CONFIDENCE OF
STORMS IS TOO LOW TO MENTION. BRIEF VARIABLE GUSTY WINDS...
HAIL...AND MVFR OR LOWER CONDITIONS ARE POSSIBLE WITH THE
STRONGEST STORMS. MOST STORMS WILL BE EAST OF ALL TAF SITES BY
04Z.
ADDITIONAL MVFR/IFR CONDITIONS MAY DEVELOP AFTER 06Z BUT DID NOT
MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE.
MBS
&&
.PREV DISCUSSION... /ISSUED 419 AM CDT SAT APR 18 2015/
DISCUSSION...
SEVERE THUNDERSTORM POTENTIAL THIS AFTERNOON AND EVENING IS THE
MAIN CONCERN.
RAIN CHANCES THIS MORNING LOOK TO BE MAINLY CONFINED TO LOCATIONS
EAST OF I-35 WHERE MOST LATEST RADAR ECHOES WERE OCCURRING FROM A
WEAK IMPULSE ROTATING AROUND A MID/UPPER LOW IN SOUTHERN
COLORADO. NO SEVERE STORMS ARE EXPECTED WITH THIS ACTIVITY...JUST
SOME LOCALIZED HEAVY RAIN. MOST OF THIS ACTIVITY MAY END BY 8 AM
IF THE LATEST HRRR RUNS ARE CORRECT. MOST LOCATIONS WILL REMAIN
DRY THIS MORNING.
ADDED PATCHY FOG MENTION THROUGH 11 AM THIS MORNING ACROSS PARTS
OF WESTERN OKLAHOMA AND WESTERN NORTH TEXAS WHERE SOME PARTIAL
CLEARING...ABUNDANT LOW LEVEL MOISTURE...AND LATEST HRRR RUNS
FAVOR SOME DEVELOPMENT. DOUBT IT WILL GET TOO WIDESPREAD OR DENSE.
THIS AFTERNOON AND EVENING...ISOLATED TO NUMEROUS SHOWERS AND
THUNDERSTORMS WILL DEVELOP ACROSS THE AREA. CAPPING WILL BE RATHER
WEAK. WITH MORE SUN COMPARED TO YESTERDAY...THINK CONVECTIVE
TEMPERATURES WILL BE REACHED RATHER EASILY IN THE 2 TO 5 PM TIME
FRAME. FIRST DEVELOPMENT MAY BE FOCUSED IN WESTERN OKLAHOMA AND
WESTERN NORTH TEXAS NEAR A DEVELOPING DRYLINE. WENT NEAR GUIDANCE
RAIN CHANCES. EXACTLY WHERE AND WHEN STORMS OCCUR REMAINS TRICKY
TODAY AND TONIGHT.
IN REGARDS TO SEVERE POTENTIAL THIS AFTERNOON AND EVENING...
BELIEVE THERE WILL BE SOME SEVERE STORMS WITH LARGE HAIL AS THE
MAIN CONCERN. THE AIR WILL BE MODERATELY UNSTABLE WITH MLCAPE
1500-2500 J/KG. STRONG 0-6 KM SHEAR 30-50 KT SUPPORTS SUPERCELLS
AND MULTICELLS. STRONG 0-3 KM SHEAR VALUES 25-45 KT AND VERY COLD
MID LEVELS WITH 500 MB TEMPERATURES AROUND -18C COULD SUPPORT VERY
LARGE HAIL IN SOME CELLS AS LONG AS CONVECTION IS NOT TOO
WIDESPREAD. SOME DAMAGING WINDS MAY OCCUR AS WELL IF STORMS CAN
ORGANIZE INTO CLUSTERS AND LINES. TORNADO POTENTIAL APPEARS TO BE
LIMITED DUE TO WEAK LOW LEVEL SHEAR...THOUGH NOTICED THE LATEST
RAP13 INDICATED STRONGER LOW LEVEL WINDS POSSIBLY DEVELOPING IN
SOUTHWESTERN OKLAHOMA IN THE 5 TO 9 PM TIME FRAME WHICH MAY
INCREASE THIS POTENTIAL. WILL CLOSELY MONITOR.
LOCALLY HEAVY RAINFALL MAY AGAIN OCCUR LATE THIS AFTERNOON AND
TONIGHT...THOUGH STORM MOTIONS WILL BE FASTER WHICH MAY LIMIT THE
DURATION OF HEAVY RAINFALL IN ONE GIVEN LOCATION.
MOST STORMS WILL MOVE INTO EASTERN OKLAHOMA AFTER MIDNIGHT
TONIGHT...ALLOWING FOR MOIST AND COOL CONDITIONS. WOULD NOT BE
SURPRISED IF SOME FOG FORMED...BUT DID NOT MENTION DUE TO LOW
CONFIDENCE.
ON SUNDAY...A FEW SHOWERS AND STORMS MAY LINGER MAINLY OVER
NORTHERN OKLAHOMA...THOUGH APPEARS THE SEVERE POTENTIAL WILL SHIFT
IN FAR EASTERN OKLAHOMA AND POINTS EAST. WITH LINGERING WEAK
INSTABILITY AND COLD MID/UPPER LEVELS...A FEW STORMS WITH SMALL
HAIL COULD OCCUR. BREEZY CONDITIONS WILL DEVELOP. THERE IS AN
OUTSIDE CHANCE WINDS COULD APPROACH ADVISORY CRITERIA WITH GUSTS
OVER 40 MPH IN NORTHWEST OKLAHOMA. WENT WITH THE WARMER SIDE OF
GUIDANCE TEMPERATURES THINKING SOME SUN WILL OCCUR...ESPECIALLY
EARLY IN THE DAY.
SUNDAY NIGHT THROUGH FRIDAY...A WET PATTERN MAY CONTINUE WITH
RAIN CHANCES REMAINING IN THE FORECAST MOST DAYS. THERE ARE SOME
MODEL DISCREPANCIES WITH WEATHER FEATURES...THUS FORECAST
CONFIDENCE REMAINS LOW. SOME STRONG TO SEVERE STORMS MAY OCCUR
TUESDAY THROUGH FRIDAY WITH NEARBY MOISTURE AND INSTABILITY.
MBS
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17/17
AREA FORECAST DISCUSSION
NWS NORMAN OK
646 AM CDT SAT APR 18 2015
.DISCUSSION...
AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW.
&&
.AVIATION...
HAVE LOW CONFIDENCE OF VFR TO LIFR CONDITIONS IN WESTERN OKLAHOMA
THROUGH 21Z AS WELL AS LOW CONFIDENCE WITH TSRA TIMING/COVERAGE
AFTER 19Z.
CONDITIONS WILL BOUNCE BETWEEN VFR AND LIFR WITH BR/FG ACROSS
WESTERN OKLAHOMA THROUGH 21Z. THE WORST CONDITIONS MAY BE NEAR
KCSM AND KHBR THROUGH 15Z. IFR CONDITIONS MAY AFFECT KSPS AND KLAW
AS WELL THROUGH 15Z...BUT DID NOT MENTION THINKING THESE LOWER
CONDITIONS WILL STAY WEST OF THESE SITES.
HAVE HIGH CONFIDENCE ALL SITES WILL BE VFR BY 21Z.
ISO-NUM TSRA WILL FORM AND AFFECT MANY TAF SITES AFTER 19Z. USED
VCTS/TEMPOS AT MOST SITES EXCEPT KCSM AND KHBR WHERE CONFIDENCE OF
STORMS IS TOO LOW TO MENTION. BRIEF VARIABLE GUSTY WINDS...
HAIL...AND MVFR OR LOWER CONDITIONS ARE POSSIBLE WITH THE
STRONGEST STORMS. MOST STORMS WILL BE EAST OF ALL TAF SITES BY
04Z.
ADDITIONAL MVFR/IFR CONDITIONS MAY DEVELOP AFTER 06Z BUT DID NOT
MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE.
MBS
&&
.PREV DISCUSSION... /ISSUED 419 AM CDT SAT APR 18 2015/
DISCUSSION...
SEVERE THUNDERSTORM POTENTIAL THIS AFTERNOON AND EVENING IS THE
MAIN CONCERN.
RAIN CHANCES THIS MORNING LOOK TO BE MAINLY CONFINED TO LOCATIONS
EAST OF I-35 WHERE MOST LATEST RADAR ECHOES WERE OCCURRING FROM A
WEAK IMPULSE ROTATING AROUND A MID/UPPER LOW IN SOUTHERN
COLORADO. NO SEVERE STORMS ARE EXPECTED WITH THIS ACTIVITY...JUST
SOME LOCALIZED HEAVY RAIN. MOST OF THIS ACTIVITY MAY END BY 8 AM
IF THE LATEST HRRR RUNS ARE CORRECT. MOST LOCATIONS WILL REMAIN
DRY THIS MORNING.
ADDED PATCHY FOG MENTION THROUGH 11 AM THIS MORNING ACROSS PARTS
OF WESTERN OKLAHOMA AND WESTERN NORTH TEXAS WHERE SOME PARTIAL
CLEARING...ABUNDANT LOW LEVEL MOISTURE...AND LATEST HRRR RUNS
FAVOR SOME DEVELOPMENT. DOUBT IT WILL GET TOO WIDESPREAD OR DENSE.
THIS AFTERNOON AND EVENING...ISOLATED TO NUMEROUS SHOWERS AND
THUNDERSTORMS WILL DEVELOP ACROSS THE AREA. CAPPING WILL BE RATHER
WEAK. WITH MORE SUN COMPARED TO YESTERDAY...THINK CONVECTIVE
TEMPERATURES WILL BE REACHED RATHER EASILY IN THE 2 TO 5 PM TIME
FRAME. FIRST DEVELOPMENT MAY BE FOCUSED IN WESTERN OKLAHOMA AND
WESTERN NORTH TEXAS NEAR A DEVELOPING DRYLINE. WENT NEAR GUIDANCE
RAIN CHANCES. EXACTLY WHERE AND WHEN STORMS OCCUR REMAINS TRICKY
TODAY AND TONIGHT.
IN REGARDS TO SEVERE POTENTIAL THIS AFTERNOON AND EVENING...
BELIEVE THERE WILL BE SOME SEVERE STORMS WITH LARGE HAIL AS THE
MAIN CONCERN. THE AIR WILL BE MODERATELY UNSTABLE WITH MLCAPE
1500-2500 J/KG. STRONG 0-6 KM SHEAR 30-50 KT SUPPORTS SUPERCELLS
AND MULTICELLS. STRONG 0-3 KM SHEAR VALUES 25-45 KT AND VERY COLD
MID LEVELS WITH 500 MB TEMPERATURES AROUND -18C COULD SUPPORT VERY
LARGE HAIL IN SOME CELLS AS LONG AS CONVECTION IS NOT TOO
WIDESPREAD. SOME DAMAGING WINDS MAY OCCUR AS WELL IF STORMS CAN
ORGANIZE INTO CLUSTERS AND LINES. TORNADO POTENTIAL APPEARS TO BE
LIMITED DUE TO WEAK LOW LEVEL SHEAR...THOUGH NOTICED THE LATEST
RAP13 INDICATED STRONGER LOW LEVEL WINDS POSSIBLY DEVELOPING IN
SOUTHWESTERN OKLAHOMA IN THE 5 TO 9 PM TIME FRAME WHICH MAY
INCREASE THIS POTENTIAL. WILL CLOSELY MONITOR.
LOCALLY HEAVY RAINFALL MAY AGAIN OCCUR LATE THIS AFTERNOON AND
TONIGHT...THOUGH STORM MOTIONS WILL BE FASTER WHICH MAY LIMIT THE
DURATION OF HEAVY RAINFALL IN ONE GIVEN LOCATION.
MOST STORMS WILL MOVE INTO EASTERN OKLAHOMA AFTER MIDNIGHT
TONIGHT...ALLOWING FOR MOIST AND COOL CONDITIONS. WOULD NOT BE
SURPRISED IF SOME FOG FORMED...BUT DID NOT MENTION DUE TO LOW
CONFIDENCE.
ON SUNDAY...A FEW SHOWERS AND STORMS MAY LINGER MAINLY OVER
NORTHERN OKLAHOMA...THOUGH APPEARS THE SEVERE POTENTIAL WILL SHIFT
IN FAR EASTERN OKLAHOMA AND POINTS EAST. WITH LINGERING WEAK
INSTABILITY AND COLD MID/UPPER LEVELS...A FEW STORMS WITH SMALL
HAIL COULD OCCUR. BREEZY CONDITIONS WILL DEVELOP. THERE IS AN
OUTSIDE CHANCE WINDS COULD APPROACH ADVISORY CRITERIA WITH GUSTS
OVER 40 MPH IN NORTHWEST OKLAHOMA. WENT WITH THE WARMER SIDE OF
GUIDANCE TEMPERATURES THINKING SOME SUN WILL OCCUR...ESPECIALLY
EARLY IN THE DAY.
SUNDAY NIGHT THROUGH FRIDAY...A WET PATTERN MAY CONTINUE WITH
RAIN CHANCES REMAINING IN THE FORECAST MOST DAYS. THERE ARE SOME
MODEL DISCREPANCIES WITH WEATHER FEATURES...THUS FORECAST
CONFIDENCE REMAINS LOW. SOME STRONG TO SEVERE STORMS MAY OCCUR
TUESDAY THROUGH FRIDAY WITH NEARBY MOISTURE AND INSTABILITY.
MBS
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17/17
AREA FORECAST DISCUSSION
NWS NORMAN OK
419 AM CDT SAT APR 18 2015
.DISCUSSION...
SEVERE THUNDERSTORM POTENTIAL THIS AFTERNOON AND EVENING IS THE
MAIN CONCERN.
RAIN CHANCES THIS MORNING LOOK TO BE MAINLY CONFINED TO LOCATIONS
EAST OF I-35 WHERE MOST LATEST RADAR ECHOES WERE OCCURRING FROM A
WEAK IMPULSE ROTATING AROUND A MID/UPPER LOW IN SOUTHERN
COLORADO. NO SEVERE STORMS ARE EXPECTED WITH THIS ACTIVITY...JUST
SOME LOCALIZED HEAVY RAIN. MOST OF THIS ACTIVITY MAY END BY 8 AM
IF THE LATEST HRRR RUNS ARE CORRECT. MOST LOCATIONS WILL REMAIN
DRY THIS MORNING.
ADDED PATCHY FOG MENTION THROUGH 11 AM THIS MORNING ACROSS PARTS
OF WESTERN OKLAHOMA AND WESTERN NORTH TEXAS WHERE SOME PARTIAL
CLEARING...ABUNDANT LOW LEVEL MOISTURE...AND LATEST HRRR RUNS
FAVOR SOME DEVELOPMENT. DOUBT IT WILL GET TOO WIDESPREAD OR DENSE.
THIS AFTERNOON AND EVENING...ISOLATED TO NUMEROUS SHOWERS AND
THUNDERSTORMS WILL DEVELOP ACROSS THE AREA. CAPPING WILL BE RATHER
WEAK. WITH MORE SUN COMPARED TO YESTERDAY...THINK CONVECTIVE
TEMPERATURES WILL BE REACHED RATHER EASILY IN THE 2 TO 5 PM TIME
FRAME. FIRST DEVELOPMENT MAY BE FOCUSED IN WESTERN OKLAHOMA AND
WESTERN NORTH TEXAS NEAR A DEVELOPING DRYLINE. WENT NEAR GUIDANCE
RAIN CHANCES. EXACTLY WHERE AND WHEN STORMS OCCUR REMAINS TRICKY
TODAY AND TONIGHT.
IN REGARDS TO SEVERE POTENTIAL THIS AFTERNOON AND EVENING...
BELIEVE THERE WILL BE SOME SEVERE STORMS WITH LARGE HAIL AS THE
MAIN CONCERN. THE AIR WILL BE MODERATELY UNSTABLE WITH MLCAPE
1500-2500 J/KG. STRONG 0-6 KM SHEAR 30-50 KT SUPPORTS SUPERCELLS
AND MULTICELLS. STRONG 0-3 KM SHEAR VALUES 25-45 KT AND VERY COLD
MID LEVELS WITH 500 MB TEMPERATURES AROUND -18C COULD SUPPORT VERY
LARGE HAIL IN SOME CELLS AS LONG AS CONVECTION IS NOT TOO
WIDESPREAD. SOME DAMAGING WINDS MAY OCCUR AS WELL IF STORMS CAN
ORGANIZE INTO CLUSTERS AND LINES. TORNADO POTENTIAL APPEARS TO BE
LIMITED DUE TO WEAK LOW LEVEL SHEAR...THOUGH NOTICED THE LATEST
RAP13 INDICATED STRONGER LOW LEVEL WINDS POSSIBLY DEVELOPING IN
SOUTHWESTERN OKLAHOMA IN THE 5 TO 9 PM TIME FRAME WHICH MAY
INCREASE THIS POTENTIAL. WILL CLOSELY MONITOR.
LOCALLY HEAVY RAINFALL MAY AGAIN OCCUR LATE THIS AFTERNOON AND
TONIGHT...THOUGH STORM MOTIONS WILL BE FASTER WHICH MAY LIMIT THE
DURATION OF HEAVY RAINFALL IN ONE GIVEN LOCATION.
MOST STORMS WILL MOVE INTO EASTERN OKLAHOMA AFTER MIDNIGHT
TONIGHT...ALLOWING FOR MOIST AND COOL CONDITIONS. WOULD NOT BE
SURPRISED IF SOME FOG FORMED...BUT DID NOT MENTION DUE TO LOW
CONFIDENCE.
ON SUNDAY...A FEW SHOWERS AND STORMS MAY LINGER MAINLY OVER
NORTHERN OKLAHOMA...THOUGH APPEARS THE SEVERE POTENTIAL WILL SHIFT
IN FAR EASTERN OKLAHOMA AND POINTS EAST. WITH LINGERING WEAK
INSTABILITY AND COLD MID/UPPER LEVELS...A FEW STORMS WITH SMALL
HAIL COULD OCCUR. BREEZY CONDITIONS WILL DEVELOP. THERE IS AN
OUTSIDE CHANCE WINDS COULD APPROACH ADVISORY CRITERIA WITH GUSTS
OVER 40 MPH IN NORTHWEST OKLAHOMA. WENT WITH THE WARMER SIDE OF
GUIDANCE TEMPERATURES THINKING SOME SUN WILL OCCUR...ESPECIALLY
EARLY IN THE DAY.
SUNDAY NIGHT THROUGH FRIDAY...A WET PATTERN MAY CONTINUE WITH
RAIN CHANCES REMAINING IN THE FORECAST MOST DAYS. THERE ARE SOME
MODEL DISCREPANCIES WITH WEATHER FEATURES...THUS FORECAST
CONFIDENCE REMAINS LOW. SOME STRONG TO SEVERE STORMS MAY OCCUR
TUESDAY THROUGH FRIDAY WITH NEARBY MOISTURE AND INSTABILITY.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 77 55 72 45 / 50 70 20 10
HOBART OK 79 50 72 42 / 50 20 10 0
WICHITA FALLS TX 81 53 76 46 / 50 30 10 0
GAGE OK 77 47 66 38 / 40 20 20 10
PONCA CITY OK 75 54 71 41 / 50 70 60 10
DURANT OK 76 58 76 49 / 50 60 20 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
141 AM EDT SAT APR 18 2015
.SYNOPSIS...
DRIER AND WARMER AIR WILL SPREAD INTO THE REGION THROUGH SATURDAY. A
WARM FRONT WILL LIFT NORTHEAST ACROSS THE AREA SATURDAY NIGHT INTO
SUNDAY...ACCOMPANIED BY ABUNDANT MOISTURE AND MORE RAINFALL. A COLD
FRONT WILL CROSS THE AREA ON MONDAY...USHERING IN SEASONABLE
TEMPERATURES AND DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 140 AM...WIDESPREAD PRECIP BEGINNING TO MOVE EAST OF THE AREA.
EXPECT THIS TREND TO CONTINUE WITH ONLY SPOTTY LIGHT SHRA FOR THE
REST OF THE NITE. OTHERWISE...GOING FCST ON TRACK WITH CLOUDY SKIES
AND MILD TEMPS. PATCHY DENSE FOG LIKELY ALONG THE UPPER SAVANNAH
RIVER VALLEY AND LITTLE TENNESSEE BASIN...WITH AREAS OF DENSE FOG
POSSIBLE. PATCHY DENSE FOG COULD DEVELOP ELSEWHERE AS WELL. MAIN
UPDATES WERE FOR CURRENT CONDITIONS.
AS OF 1030 PM EDT FRIDAY...WIDESPREAD SHOWERS STILL COVER THE
UPSTATE AND PORTIONS OF THE MOUNTAINS...SO CONTINUING CATEGORICAL
POPS FOR ANOTHER COUPLE OF HOURS UNTIL THE SHORTWAVE AXIS PUSHES
THROUGH STILL LOOKS GOOD. TEMPERATURES ON TRACK FOR THE MOST PART SO
ONLY MINOR TWEAKS TO HOURLY TRENDS.
AS OF 730 PM EDT FRIDAY...HAVE BUMPED UP POPS ACROSS MOST OF THE
AREA THIS EVENING INTO THE OVERNIGHT PERIOD TO ACCOUNT FOR FAIRLY
WIDESPREAD LIGHT RAIN/SHOWERS MOVING ACROSS THE AREA...FORCED BY THE
RELATIVELY STRONG SHORTWAVE MOVING ACROSS THE SOUTHEAST THIS
EVENING. IF THE HRRR IS TO BE BELIEVED...THESE SHOWERS COULD LINGER
OVERNIGHT AND PAST SUNRISE...AND WILL EVALUATE FURTHER FOR THE LATE
EVENING UPDATE. BEST MOISTURE REMAINS ACROSS THE UPSTATE AND
NORTHEAST GEORGIA BUT STILL SEEING SOME LIGHT RAIN ACROSS THE
MOUNTAINS AND FOOTHILLS. STILL SEEING SOME SBCAPE VALUES HOLDING ON
ACROSS THE PIEDMONT BUT THESE SHOULD BEGIN DROPPING RAPIDLY WITH
SUNSET...SO HAVE PULLED BACK ON THUNDER WORDING THIS EVENING AND
OVERNIGHT. OTHER GRIDS IN GOOD SHAPE FOR THE MOST PART...WITH ONLY
MINOR TWEAKS TO ACCOUNT FOR HOURLY TRENDS.
AS OF 430 PM EDT FRIDAY...VERY LITTLE CHANGE TO PREVIOUS THINKING
FOR THE NEAR TERM. PRECIPITATION BEGINNING TO OVERSPREAD WESTERN AND
SOUTHWESTERN ZONES AS EXPECTED. NEW GUIDANCE BEGINNING TO PULL BACK
A LITTLE ON CONVECTIVE POTENTIAL...WITH INCREASING CLOUD COVER AND
MOISTENING ATMOSPHERE WHAT LITTLE SBCAPE WAS BEGINNING TO CREEP INTO
THE MESOANALYSES OVER THE PAST COUPLE OF HOURS IS ONCE AGAIN FALLING
OFF. LOOKING AT HI-RES REFLECTIVITY FORECASTS...DEFINITELY STARTING
TO LOOK LIKE MORE STRATIFORM RAIN OR SHOWERS WITH THE POSSIBILITY OF
EMBEDDED THUNDER. HAVE LEFT WEATHER WORDING AS IS FOR NOW SINCE
CURRENTLY ADVERTISED THUNDER IS CHANCE AT BEST...BUT WILL REEVALUATE
MORE THOROUGHLY FOR NEXT NEAR-TERM UPDATE. ONLY MINOR TWEAKS TO
TEMPS AND DEWPOINTS TO UPDATE TRENDS.
AS OF 245 PM EDT FRIDAY...THE SYNOPTIC PATTERN HAS NOT CHANGED ALL
THAT MUCH FROM YESTERDAY...OR DAYS PAST FOR THAT MATTER. IT STILL
FEATURES ROTATING CLOSE UPPER LOW OVER THE FOUR CORNERS WHILE DEEP
SOUTHWEST WAA PREVAILS ACROSS THE SOUTHEAST UNITED STATES. AT
THE SURFACE...SPRINGTIME WEDGE STARTING TO ERODE AS EXPECTED THIS
AFTERNOON AS WINDS HAVE VEERED SOUTHERLY ACROSS NORTHEAST GA AND THE
UPSTATE...ALONG WITH A FEW LOCATIONS OVER THE NC PIEDMONT.
FURTHERMORE...H5 SHORT WAVE AND ASSOCIATED VORTICITY MAXIMA
CONTINUES TO SLIDE EAST ACROSS THE DEEP SOUTH WITH A BROAD AREA OF
PRECIPITATION ACCOMPANYING. LATEST SPC MESO ANALYSIS NOT ALL THAT
IMPRESSIVE AS INSTABILITY REMAINS NEARLY NONEXISTENT ACROSS THE FCST
AREA. MODELS FAVOR IMPROVING LAPSE RATES WITH HEATING THIS
AFTERNOON...HOWEVER STILL SKEPTICAL AS PRECIP SHIELD AND ASSOCIATED
LOW OVERCAST SKY COVER WILL LIMIT HEATING. NEVERTHELESS...THE FCST
DOES FEATURE INCREASING POPS THROUGH THE AFTERNOON/EVENING HOURS
WITH CHANCES FOR THUNDER MENTIONED...AND WILL CONTINUE WITH SUCH IN
THE HWO. POPS WILL LOWER AFTER MIDNIGHT AS THE PRIMARY UPPER WAVE
EJECTS TO THE EAST...AND A WEAK/DRY BACK DOOR FRONT SLIDES SOUTHWARD
ACROSS THE REGION. HELD ON TO TOKEN SLIGHT/CHANCE POPS THROUGH
MORNING TO ACCOUNT FOR ANY RESIDUAL SHRA ALONG THE BOUNDARY. LATEST
SOUNDINGS DO NOT SUGGEST AS MUCH MID DRYING AS THE PREVIOUS
RUN...THEREFORE NOT ALL THAT CONFIDENT IN AREAS OF DENSE FOG
OVERNIGHT. THAT SAID...WOULDNT BE SURPRISED TO SEE ISOLATED CASES OF
SUCH ACROSS THE NC PIEDMONT/FOOTHILLS JUST AHEAD OF THE INTRUDING
BOUNDARY WHEN WINDS ARE CALMEST AND THE PBL IS DECOUPLED.
SATURDAY WILL BE HIGHLIGHTED BY DECREASING CLOUDINESS AS DOWNSLOPING
FLOW PREVAILS AMONGST INCREASING HEIGHTS ALOFT AS AXIS OF SHORTWAVE
RIDGE SHIFTS OVERHEAD. POPS WILL INCREASE YET AGAIN THROUGH THE DAY
AS FCST SOUNDINGS INDICATE MODEST DESTABILIZATION WITH HEATING.
HOWEVER EXPECTING UPPER RIDGING TO PROVIDE SOME SUBSIDENCE THEREFORE
KEPT POPS AT OR BELOW CHANCE LEVELS THROUGH THE DAY. TEMPERATURES
ON SATURDAY WILL DEPEND HIGHLY ON HOW SOON THE SKY COVER SCT OUT.
TOOK A MIDDLE OF THE ROAD APPROACH AS IT PERTAINS TO GUIDANCE...WITH
THE FCST FEATURING HIGHS 3-5 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 200 PM FRIDAY...TWO AREAS OF CONCERN TO DEAL WITH IN THE SHORT
TERM. THE FIRST WILL BE A PERIOD OF HEAVY RAIN ON SUNDAY AND THEN A
RISK OF SEVERE STORMS ON MONDAY.
THE UPPER RIDGE OVER THE SOUTHEAST U.S. WILL TRANSLATE EASTWARD
SATURDAY NIGHT AS THE UPPER LOW THAT HAS BEEN OVER THE 4-CORNERS
BEGINS TO MOVE EAST THANKS TO A DIGGING TROUGH MOVING SE OUT OF THE
CANADIAN PRAIRE. A SHORT WAVE OUT AHEAD OF THE UPPER LOW WILL MOVE
NE FROM THE GULF COAST AND ACROSS THE WESTERN CAROLIANS AND NE GA ON
SUNDAY. AT THE SURFACE...A WARM FRONT WILL APPROACH FROM THE SW ON
SUNDAY. ALL OF THIS WILL RESULT IN ALL TYPES OF FORCING ACROSS THE
REGION ON SUNDAY. PWATS WILL BE IN THE 1.5-1.7" RANGE WITH A 35-45
KT SELY 850 MB JET INTO THE BLUE RIDGE. WILL RAMP POPS UP QUICKLY TO
CATEGORICAL FROM WEST TO EAST BY MIDDAY SUNDAY...THEN DECREASE
RAPIDLY FROM WEST TO EAST LATE SUNDAY AS THE AXIS OF DEEP MOISTURE
AND FORCING SHIFT EAST. HEAVY RAIN LOOKS TO BE A GOOD BET...BUT THE
RELATIVELY QUICK MOVEMENT OF THE SYSTEM SHOULD PRECLUDE ANY SERIOUS
HYDRO ISSUES. BLENDING THE MODEL CONSENSUS AND WPC QPF GUIDANCE...
RESULTS IN GENERALLY 1.5"-2.0" FROM LATE SATURDAY NIGHT INTO SUNDAY
NIGHT. THE HIGHEST AMOUNTS AS USUAL ARE EXPECTED TO BE NEAR THE BLUE
RIDGE ESCARPMENT WHERE 2-3" OF RAIN CAN BE EXPECTED. THESE VALUES
ARE UNDER THE 12 TO 24 HOUR FFG. THERE MAY BE SOME LOCALIZED
FLOODING BUT WIDESPREAD FLOODING IS UNLIKELY. HOWEVER...WILL
CONTINUE TO MENTION HEAVY RAIN IN THE HWO. AN IN SITU WEDGE WILL
RESULT IN COOL TEMPS ON SUNDAY AND WILL THEREFORE TREND TOWARD
CONSRAW GUIDANCE TEMPS.
SOME DEGREE OF CLEARING SHOULD OCCUR SUNDAY NIGHT AS THE AXIS OF
DEEP MOISTURE SHIFTS NE AND A DOWNSLOPE WIND COMPONENT THROUGH THE
COLUMN DEVLOPS. ON MONDAY...A COLD FRONT WILL MOVE ACROSS THE REGION
FROM WEST TO EAST. BOTH THE NAM AND GFS INDICATE THAT THE ATMOSPHERE
WILL DESTABLIZE BY AFTERNOON WITH CAPES MOST LIKELY INCREASING TO
BETWEEN 1000 AND 1500 J/KG PER GFS AND ECM. ALSO...0-6KM SHEAR
INCREASES TO ABOUT 40KT. THIS MAY SUPPORT SOME ORGANIZION TO THE
CONVECTION AS THE COLD FRONT MOVES THROUGH. THE 12Z NAM MODEL
REFLECTIVY SUGGESTS THAT A BROKEN LINE OF CONVECTION WILL ACCOMPANY
THE FRONT ACROSS THE AREA ON MONDAY WITH A FEW SEVERE STORMS
POSSIBLE. WITH THE AREA SOLIDLY IN THE WARM SECTOR ON MONDAY...MAX
TEMPS ARE EXPECTED TO BE ABOUT 5 DEGREES ABOVE CLIMO.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 245 PM FRIDAY...MONDAY NIGHT...SFC HIGH PRESSURE WILL BUILD
OVER THE FORECAST AREA IN THE WAKE OF A PASSING COLD FRONT. 12Z GFS
INDICATES THAT H85 TEMPERATURES WILL COOL BY 5 C FROM 0Z TO 12Z
TUESDAY...A LITTLE LESS COOLING ON THE ECMWF. USING A BLEND OF
GUIDANCE...I WILL FORECAST LOW TEMPERATURES FROM THE UPPER 40S
WITHIN THE MTN VALLEYS TO MID 50S EAST. ON TUESDAY...BROAD HIGH
PRESSURE WILL REMAIN ACROSS THE CWA. THE REGION SHOULD SEE MOSTLY
SUNNY CONDITIONS WITH A LIGHT SOUTHWEST WIND. TEMPERATURES SHOULD
RESPOND TO THE LATE APRIL SUN AND WEAK DOWNSLOPING...FORECAST TUES
HIGHS SLIGHTLY ABOVE NORMAL.
WEDNESDAY THROUGH FRIDAY...THE GFS AND ECMWF GENERALLY AGREE THAT A
LARGE CLOSED MID LEVEL LOW WILL REMAIN ACROSS THE NORTHEAST AND
EASTERN CANADA...AS A RIDGE LINGERS OVER THE SOUTHERN PLAINS. THE
HEIGHTS ACROSS THE CWA WILL LIKELY REMAIN NW TO SE THROUGH THE
PERIOD. THE MODELS ARE IN LESS AGREEMENT WITH THE PLACEMENT AND
TIMING OF SFC FEATURES...PRIMARILY WEAK FRONTS AND PRESSURE CENTERS.
I AM MORE CONFIDENT TIMING MID LEVEL FEATURES WITHIN THE NW FLOW
ACROSS THE SOUTHERN APPALACHIANS...I WILL FAVOR THE ECMWF.
OVERALL...I WILL KEEP CONDITIONS DRY ON WED...BUT MOISTURE WILL
INCREASE THROUGH THE DAY. A SHORT SERIES OF MID LEVEL S/W ARE
FORECAST TO RIPPLE ACROSS THE CWA THURSDAY THROUGH FRIDAY.
TEMPERATURES SHOULD RANGE CLOSE TO NORMAL WITH AFTERNOON DEWPOINTS
ONLY IN THE 40S. GIVEN THE TRACK OF THE MID LEVEL DISTURBANCES AND
WEAK DIURNAL INSTABILITY...I WILL INDICATE ONLY SCHC POPS ACROSS THE
MTNS ON THURSDAY. FORECAST SOUNDINGS SHOW GREATER INSTABILITY FRIDAY
AFTERNOON...FROM THE MTNS TO THE PIEDMONT. THE COMBINATION OF THE
PASSING DISTURBANCE AND INSTABILITY SHOULD SUPPORT SCT COVERAGE
ACROSS THE MTNS AND ISO EAST.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...CANNOT RULE OUT A BRIEF MVFR VSBY OR CIG AS SHRA MOVE
ACROSS THE AIR FIELD EARLY THIS MORNING. HOWEVER...DO EXPECT
CONDITIONS TO FALL TO MVFR THEN IFR TOWARD DAYBREAK AFTER THE PRECIP
ENDS. EXPECT LOW VFR BY NOON OR SO AS FORCING ENDS AND LOW LEVEL
MOISTURE MIXES OUT. MVFR COULD RETURN BY THE END OF THE PERIOD...BUT
MORE LIKELY TOWARD THE END OF THE NEXT TAF ISSUANCE. LIGHT NORTH OR
CALM WIND EARLY THIS MORNING BECOMES LIGHT NE...THEN ENE THRU THE
DAY.
ELSEWHERE...PRECIP WILL SOON MOVE EAST OF THE AREA AND CONDITIONS
WILL FALL TO IFR BEFORE DAYBREAK. IN FACT...LIFR LIKELY...LIKE THE
CURRENT CONDITIONS AT KAND. EXPECT A SLOW IMPROVEMENT TO LOW VFR
THRU THE MORNING. MVFR AND PRECIP MOVE BACK IN FROM THE WEST
TONIGHT. CALM WIND BECOMES NE THIS MORNING...THEN ENE TONIGHT. KAVL
WILL SEE NLY WIND BECOMING SLY TODAY...REMAINING THERE TONIGHT.
OUTLOOK...DEEPER MOISTURE WILL RETURN ALONG A WARM FRONT THROUGH
SUNDAY...WITH HEAVY RAINFALL AND WIDESPREAD RESTRICTIONS LIKELY ONCE
AGAIN. THUNDERSTORMS WILL THEN BE POSSIBLE THROUGH MONDAY AS A COLD
FRONT REACHES THE AREA FROM THE WEST.
CONFIDENCE TABLE...
05-11Z 11-17Z 17-23Z 23-00Z
KCLT MED 66% MED 62% LOW 57% HIGH 100%
KGSP MED 75% MED 62% MED 64% HIGH 100%
KAVL HIGH 100% HIGH 87% LOW 59% HIGH 100%
KHKY HIGH 100% HIGH 87% MED 66% HIGH 100%
KGMU HIGH 91% MED 69% MED 71% HIGH 100%
KAND MED 75% MED 75% LOW 52% HIGH 90%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...CSH
NEAR TERM...CDG/RWH/TDP
SHORT TERM...LG
LONG TERM...NED
AVIATION...RWH
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1243 PM CDT SAT APR 18 2015
.UPDATE...
ISSUED AT 1030 AM CDT SAT APR 18 2015
WITH DRY AIR IN PLACE...ERODING NORTHERN EXTENT OF SHOWER
ACTIVITY...REDUCED POPS/QPF NORTH OF THE MAIN BAND OF
PRECIPITATION FOR THE AFTERNOON IN LINE WITH LATEST HRRR AND RUC
GUIDANCE. LATEST NAM IS IN LINE WITH CURRENT FORECAST AFTER 00Z.
HRRR COLUMN MAX REF DOES LOOK LIKE A WEAK FEW CONVECTIVE CELLS
FORM OVER THE CWA TODAY SO WILL LEAVE MENTION OF THUNDER IN.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 327 AM CDT SAT APR 18 2015
PRECIPITATION CHANCES OVER THE NEXT 24 HOURS...AND WINDS SUNDAY
AND MONDAY WILL BE THE FORECAST CHALLENGES.
A FAIRLY DRY AIR MASS REMAINS IN PLACE ACROSS MOST OF THE CWA THIS
MORNING WITH DEW POINTS MAINLY IN THE UPPER 20S. HIGHER DEW
POINTS ARE ADVECTING NORTHWESTWARD INTO WESTERN SOUTH DAKOTA WHERE
VALUES IN THE 40S. THESE HIGHER DEW POINTS...ALONG WITH SOME
SHOWERS AND THUNDERSTORMS WILL SLOWLY TRACK NORTHWARD THROUGH THE
DAY AS AN UPPER LEVEL LOW PRESSURE SYSTEM MOVES ACROSS THE CENTRAL
PLAINS. VARIOUS HI-RES MODELS SUGGEST SHOWERS WOULD REACH HIGHWAY
212 AROUND 18Z...AND HIGHWAY 12 BETWEEN 21-0Z THIS AFTERNOON. HAVE
TRIED TO DELAY POPS IN THE NORTHERN AND FAR NORTHEASTERN PORTION
OF THE CWA UNTIL AFTER 21Z. PCPN MAY NOT REACH THE
SISSETON/WHEATON AREA UNTIL AFTER 0Z SUNDAY.
TONIGHT THROUGH SUNDAY MORNING...MODELS SUGGEST THE LOW PRESSURE
SYSTEM WILL MERGE WITH A NORTHERN STREAM TROUGH...WHICH COULD
BRING BETTER CHANCES FOR SHOWERS. THE NORTHERN STREAM WILL LIKELY
BRING GUSTY NORTHWESTERLY WINDS TONIGHT ALONG A SURFACE COLD
FRONT. A FAIRLY DRY AIR MASS WILL FOLLOW THIS COLD FRONT WITH PCPN
LIKELY ENDING FROM WEST TO EAST BY THE MID MORNING HOURS ON
SUNDAY. BY SUNDAY AFTERNOON COLD AIR ADVECTION WILL DEVELOP WITH
GUSTY NORTHWESTERLY WINDS AND INSTABILITY SHOWERS POSSIBLE. WINDS
MAY EXCEED ADVISORY LEVELS...ESPECIALLY IN THE WESTERN HALF OF THE
CWA. A TIGHT PRESSURE GRADIENT OVER THE REGION WILL PROMOTE GUSTY
NORTHWESTERLY WINDS ON MONDAY AS WELL. COLD AIR ALOFT...ALONG WITH
CAPE VALUES AROUND 100 J/KG COULD PRODUCE ISOLATED SHOWERS IN THE
FAR EASTERN PORTION OF THE CWA MONDAY AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT APR 18 2015
NOT MUCH CHANGE NOTED IN THE LONGER RANGE MODEL OUTPUT...COMPARED
TO 24 HOURS. PRECIPITATION CHANCES ARE PRETTY MUCH DONE AND GONE
MONDAY NIGHT...WITH A MAINLY DRY FORECAST THERE-AFTER /DRY AND
COOL NORTHWEST FLOW ESTABLISHING OVER THE NORTHERN PLAINS ALOFT/.
BY THURSDAY...THERE IS A RATHER SLIM CHANCE THAT ENERGY TRYING
TO LIFT NORTH-NORTHEAST TOWARD THE NORTHERN PLAINS COULD INTRODUCE
SOME DEFORMATION ZONE-FORCED LIGHT PRECIP POTENTIAL ACROSS THE
SOUTHWESTERN FORECAST ZONES...PRIOR TO EXPERIENCING THE SHEARING
EFFECTS OF NORTHWEST /POLAR JET/ FLOW ALOFT. SUPERBLEND CONTINUES
TO PRODUCE SOME LOW PROBABILITIES FOR PRECIPITATION THURSDAY
NIGHT/FRIDAY THOUGH. UNDER THIS NORTHWEST FLOW ALOFT REGIME...LOW
LEVEL FLOW IS PERSISTENTLY ADVECTING COOL/DRY AIR DOWN OUT OF
CANADA ON NORTHEASTERLY BOUNDARY LAYER MIXING WINDS. TEMPERATURES
DURING THE EXTENDED FORECAST PERIOD SHOULD BE RUNNING NEAR NORMAL
TO PERHAPS A FEW DEGREES BELOW NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1236 PM CDT SAT APR 18 2015
A LOW PRESSURE SYSTEM WILL BRING SOME SHOWERS TO THE REGION THIS
AFTERNOON AND EVENING. VFR CONDITIONS ARE EXPECTED THROUGH THE
PERIOD EXCEPT PERHAPS SOME BRIEF AND TRANSIENT MVFR CIGS IN HEAVIER
SHOWERS NEAR KMBG/KATY THIS EVENING. AS THE LOW EXITS SHOWERS WILL
TAPER OFF BY 9Z AND NORTHWEST WINDS WILL INCREASE TO 15 TO 25 KTS
WITH HIGHER GUSTS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...CONNELLY
SHORT TERM...SD
LONG TERM...DORN
AVIATION...WISE
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
1040 AM CDT SAT APR 18 2015
.UPDATE...
ISSUED AT 1030 AM CDT SAT APR 18 2015
WITH DRY AIR IN PLACE...ERODING NORTHERN EXTENT OF SHOWER
ACTIVITY...REDUCED POPS/QPF NORTH OF THE MAIN BAND OF
PRECIPITATION FOR THE AFTERNOON IN LINE WITH LATEST HRRR AND RUC
GUIDANCE. LATEST NAM IS IN LINE WITH CURRENT FORECAST AFTER 00Z.
HRRR COLUMN MAX REF DOES LOOK LIKE A WEAK FEW CONVECTIVE CELLS
FORM OVER THE CWA TODAY SO WILL LEAVE MENTION OF THUNDER IN.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 327 AM CDT SAT APR 18 2015
PRECIPITATION CHANCES OVER THE NEXT 24 HOURS...AND WINDS SUNDAY
AND MONDAY WILL BE THE FORECAST CHALLENGES.
A FAIRLY DRY AIR MASS REMAINS IN PLACE ACROSS MOST OF THE CWA THIS
MORNING WITH DEW POINTS MAINLY IN THE UPPER 20S. HIGHER DEW
POINTS ARE ADVECTING NORTHWESTWARD INTO WESTERN SOUTH DAKOTA WHERE
VALUES IN THE 40S. THESE HIGHER DEW POINTS...ALONG WITH SOME
SHOWERS AND THUNDERSTORMS WILL SLOWLY TRACK NORTHWARD THROUGH THE
DAY AS AN UPPER LEVEL LOW PRESSURE SYSTEM MOVES ACROSS THE CENTRAL
PLAINS. VARIOUS HI-RES MODELS SUGGEST SHOWERS WOULD REACH HIGHWAY
212 AROUND 18Z...AND HIGHWAY 12 BETWEEN 21-0Z THIS AFTERNOON. HAVE
TRIED TO DELAY POPS IN THE NORTHERN AND FAR NORTHEASTERN PORTION
OF THE CWA UNTIL AFTER 21Z. PCPN MAY NOT REACH THE
SISSETON/WHEATON AREA UNTIL AFTER 0Z SUNDAY.
TONIGHT THROUGH SUNDAY MORNING...MODELS SUGGEST THE LOW PRESSURE
SYSTEM WILL MERGE WITH A NORTHERN STREAM TROUGH...WHICH COULD
BRING BETTER CHANCES FOR SHOWERS. THE NORTHERN STREAM WILL LIKELY
BRING GUSTY NORTHWESTERLY WINDS TONIGHT ALONG A SURFACE COLD
FRONT. A FAIRLY DRY AIR MASS WILL FOLLOW THIS COLD FRONT WITH PCPN
LIKELY ENDING FROM WEST TO EAST BY THE MID MORNING HOURS ON
SUNDAY. BY SUNDAY AFTERNOON COLD AIR ADVECTION WILL DEVELOP WITH
GUSTY NORTHWESTERLY WINDS AND INSTABILITY SHOWERS POSSIBLE. WINDS
MAY EXCEED ADVISORY LEVELS...ESPECIALLY IN THE WESTERN HALF OF THE
CWA. A TIGHT PRESSURE GRADIENT OVER THE REGION WILL PROMOTE GUSTY
NORTHWESTERLY WINDS ON MONDAY AS WELL. COLD AIR ALOFT...ALONG WITH
CAPE VALUES AROUND 100 J/KG COULD PRODUCE ISOLATED SHOWERS IN THE
FAR EASTERN PORTION OF THE CWA MONDAY AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT APR 18 2015
NOT MUCH CHANGE NOTED IN THE LONGER RANGE MODEL OUTPUT...COMPARED
TO 24 HOURS. PRECIPITATION CHANCES ARE PRETTY MUCH DONE AND GONE
MONDAY NIGHT...WITH A MAINLY DRY FORECAST THERE-AFTER /DRY AND
COOL NORTHWEST FLOW ESTABLISHING OVER THE NORTHERN PLAINS ALOFT/.
BY THURSDAY...THERE IS A RATHER SLIM CHANCE THAT ENERGY TRYING
TO LIFT NORTH-NORTHEAST TOWARD THE NORTHERN PLAINS COULD INTRODUCE
SOME DEFORMATION ZONE-FORCED LIGHT PRECIP POTENTIAL ACROSS THE
SOUTHWESTERN FORECAST ZONES...PRIOR TO EXPERIENCING THE SHEARING
EFFECTS OF NORTHWEST /POLAR JET/ FLOW ALOFT. SUPERBLEND CONTINUES
TO PRODUCE SOME LOW PROBABILITIES FOR PRECIPITATION THURSDAY
NIGHT/FRIDAY THOUGH. UNDER THIS NORTHWEST FLOW ALOFT REGIME...LOW
LEVEL FLOW IS PERSISTENTLY ADVECTING COOL/DRY AIR DOWN OUT OF
CANADA ON NORTHEASTERLY BOUNDARY LAYER MIXING WINDS. TEMPERATURES
DURING THE EXTENDED FORECAST PERIOD SHOULD BE RUNNING NEAR NORMAL
TO PERHAPS A FEW DEGREES BELOW NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 651 AM CDT SAT APR 18 2015
VFR CONDITIONS ARE EXPECTED THROUGH THE FIRST PART OF TODAY AT
KPIR. HOWEVER A LOW PRESSURE SYSTEM MOVING NORTHEAST WILL SPREAD
SHOWERS AND LOWER /MVFR/ CIGS INTO KPIR BY AROUND
MID-DAY...LASTING WELL INTO TONIGHT BEFORE RELATIVELY LIGHT WINDS
SWITCH AROUND TO THE NORTHWEST AND INCREASE TO 20 TO 30 KNOTS.
VFR CONDITIONS ARE EXPECTED TO HOLD THROUGH LATE THIS
AFTERNOON/EARLY THIS EVENING AT KABR/KMBG/KATY BEFORE THE SHOWERS
AND LOWER /MVFR/ CIGS MOVE IN. LIKE KPIR...KMBG SHOULD SEE
SIMILAR TIMING ON THE CHANGE IN WIND DIRECTION AND SPEED.
HOWEVER...KABR AND KATY PROBABLY WON`T SEE THE ABRUPT SHIFT AND
INCREASE IN WIND SPEEDS UNTIL LATER TONIGHT AT OR AFTER 06Z.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...CONNELLY
SHORT TERM...SD
LONG TERM...DORN
AVIATION...DORN
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
818 PM CDT SUN APR 19 2015
.DISCUSSION...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REMOVE WORDING IN THE ZONE
FORECAST PRODUCT FOR THE THRU LATE AFTERNOON GROUPING. HAVE ALSO UPDATED
TO MATCH CURRENT REGIONAL SFC OBS....SATELLITE...AND RADAR TRENDS ALONG
WITH TWEAKS TO HRLY TEMP...DEWPOINT...SKY...AND WIND SPEED/DIRECTION GRIDS.
AN EMBEDDED SHORTWAVE IN UPPER LEVEL TROUGH THAT IS MOVING ACROSS NW INTO
NC PORTIONS OF THE MID STATE THIS EVENING SHOULD CONTINUE MOVING NEWD WITH
DEVELOPING ISO STRONG TO SVR TSTMS ASSOCIATED WITH IT GENERALLY MOVING THIS
WAY ALSO...WITH THE POSSIBILITY OF SHWRS/TSTMS MOVING INTO THE NASHVILLE METRO
AREA PRESENTLY. EXPECT MAYBE SOME ISO SHWRS/TSTMS THRU 05Z ACROSS REST OF MID
STATE. MAIN CONCERN IS LINE OF SVR CONVECTION APPROACHING THE MS RIVER VALLEY
AS OF 01Z AND ITS POTENTIAL IMPACTS ON THE MID STATE`S WX AS IT IS EXPECTED TO
APPROACH THE TN RIVER VALLEY REGION OF THE MID STATE BY 05Z.
LATEST SHORT RANGE MODELS SHOWING BRUNT OF ACTIVITY CURRENTLY OVER AR MOVING
GENERALLY NE OF MID STATE AS IT APPROACHES THE TN RIVER VALLEY BY 05Z...WITH
CONVECTION PRESENTLY ACROSS SRN AR/NRN LA MOVING NEWD DRAGGING A LINE OF
SHWRS/TSTMS INTO THE MID STATE. 00Z MON KOHX SOUNDING PROFILE AND INDICES
SHOWING RELATIVELY LOW CAPE AND LOW SHEAR VALUES AS OF THIS TIME...WITH
MARGINAL INSTABILITY AND PCPN WATER VALUES AROUND 1.2 INCHES AND UNIDIRECTIONAL
SWLY FLOW SFC/ALOFT. MODEL SOUNDINGS SHOWING SOME ENHANCEMENTS IN INSTABILITY
AND SHEAR VALUES BETWEEN 06Z-09Z ACROSS WRN AND CENTRAL PORTIONS OF THE MID
STATE WITH UNIDIRECTIONAL SWLY FLOW SFC/ALOFT CONTINUING. 01Z CONVECTIVE
OUTLOOK CURTAILING THE SLIGHT RISK OF SVR TSTM AREA ACROSS THE PLATEAU COUNTIES
AND NOW GENERALLY LIMITING THIS POSSIBILITY TO LOCATIONS W OF THE PLATEAU.
SPC STILL EXPECTING SOME WEAKENING AS THIS CURRENT LINE OF SHWRS/TSTMS
APPROACHING THE MS RIVER MOVES EWD TONIGHT PER BOUNDARY LAYER DESTABILIZATION.
WITH THIS ALL SAID...DO EXPECT A QUASI-LINEAR LINE OF SHWRS/TSTMS TO MOVE
THRU THE MID STATE FROM AROUND 11 PM ONWARD W THRU THE EARLY MORNING HRS
E...BUT WILL IT STILL CONTAIN STRONG TO SVR CONVECTION WITH IT? ALL INDICATIONS
AT THIS TIME IS THAT IT IS BORDERLINE IF IT DOES OR NOT...AS SFC FRONT ITSELF
SHOULD APPROACH THE MS RIVER BY 06Z AND THEN PUSH EWD INTO THE MID STATE
JUST W OF PLATEAU BY 12Z...AS UPPER LEVEL TROUGHING BECOMES MORE PRONOUNCED
ACROSS THE MID STATE. THUS UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT
THE ABOVE REASONING/TIMINGS MENTIONED.
&&
.PREV DISCUSSION.../ISSUED 645 PM CDT SUN APR 19 2015/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
SEVERAL ADMS POSSIBLE THRU AT LEAST 20/15Z DUE TO CEILING AND VSBY
FLUCTUATIONS AND SHWR/TSTM IMPACTS. EXPECT BEST POTENTIAL FOR
SHWRS/TSTMS NEAR CKV THRU 20/05Z PER PROXIMITY TO UPPER LEVEL TROUGH
DYNAMICS. EXPECTING BRUNT OF SHWRS/TSTMS BETWEEN 20/05Z W - 20/11Z E
AS CONVECTIVE LINE MOVES THRU MID STATE. MVFR CEILINGS TO IFR VSBYS
WILL BE POSSIBLE DURING THIS TIME PERIOD...ESPECIALLY WITH ONSET OF
SHWR/TSTM ACTIVITY AT TAF SITES. EXPECT LINGERING SHWRS BEHIND MAIN
CONVECTIVE LINE FOR AT LEAST A COUPLE OF HRS...WITH MVFR FOG INDUCED
VSBYS DEVELOPING ALSO. MVFR CEILINGS EXPECTED BY 20/15Z...WITH VFR
CEILINGS POSSIBLE 20/18Z AND AFTERWARDS.
PREV DISCUSSION.../ISSUED 200 PM CDT SUN APR 19 2015/
DISCUSSION...SURFACE MAP AT 18Z SHOWS A 1000 MB LOW CENTERED OVER
SOUTHERN ILLINOIS, WITH A WARM FROM SITUATED TO OUR NORTH, A
COLD FRONT STILL WEST OF THE MISSISSIPPI RIVER, AND A PRE-FRONTAL
TROUGH JUST NOW CROSSING THE TENNESSEE RIVER THAT IS PROVIDING THE
FOCUS FOR A DEVELOPING LINE OF CONVECTION. SATELLITE IMAGERY IS
STARTING TO SHOW SOME BREAKS IN THE CLOUDS, ESPECIALLY WEST OF
NASHVILLE. LAPS SOUNDING FOR BNA AT 18Z SHOWS WEAK INSTABILITY,
WITH A LIFTED INDEX OF -3.3 AND A CAPE OF 962 J/KG. ATMOSPHERE
REMAINS SUFFICIENTLY MOIST, WITH PRECIPITABLE WATER OF 1.44 INCHES
AND A K-INDEX OF 34. LATEST HRRR SHOWS SCATTERED CELLS ACROSS
MIDDLE TENNESSEE UNTIL A MORE ORGANIZED LINE OF CONVECTION COMES
THROUGH WITH THE COLD FRONT BETWEEN 04Z AND 09Z. GIVEN THE TIMING
OF THE FRONT, THE POTENTIAL FOR WIDESPREAD SEVERE STORMS APPEARS
LOW, ALTHOUGH MIDDLE TENNESSEE DOES REMAIN UNDER A SLIGHT RISK OF
SEVERE WEATHER TODAY AND TONIGHT, SO ISOLATED CASES OF SEVERE
ACTIVITY ARE STILL POSSIBLE. AFTER A FEW LINGERING SHOWERS ON
MONDAY, LOOK FOR A BRIEF RESPITE ON TUESDAY BEFORE THE NEXT COLD
FRONT DROPS SOUTHWARD THROUGH MIDDLE TENNESSEE WEDNESDAY AND
THURSDAY. GIVEN THAT THE UPPER FLOW ACROSS THE REGION WILL REMAIN
EITHER CYCLONIC OR ZONAL, WARM ADVECTION WILL BE HARD TO COME BY,
AND SO TEMPERATURES DURING THE NEXT 7 DAYS WILL REMAIN AT OR BELOW
NORMAL.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 61 67 44 69 / 70 30 10 10
CLARKSVILLE 58 66 42 68 / 70 30 05 10
CROSSVILLE 59 63 43 64 / 70 60 20 10
COLUMBIA 60 68 44 70 / 70 30 10 10
LAWRENCEBURG 58 68 44 70 / 70 30 10 10
WAVERLY 58 68 43 69 / 70 30 05 10
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
645 PM CDT SUN APR 19 2015
.UPDATE...FOR 00Z AVIATION DISCUSSION.
&&
.AVIATION...00Z AVIATION DISCUSSION.
SEVERAL ADMS POSSIBLE THRU AT LEAST 20/15Z DUE TO CEILING AND VSBY
FLUCTUATIONS AND SHWR/TSTM IMPACTS. EXPECT BEST POTENTIAL FOR
SHWRS/TSTMS NEAR CKV THRU 20/05Z PER PROXIMITY TO UPPER LEVEL TROUGH
DYNAMICS. EXPECTING BRUNT OF SHWRS/TSTMS BETWEEN 20/05Z W - 20/11Z E
AS CONVECTIVE LINE MOVES THRU MID STATE. MVFR CEILINGS TO IFR VSBYS
WILL BE POSSIBLE DURING THIS TIME PERIOD...ESPECIALLY WITH ONSET OF
SHWR/TSTM ACTIVITY AT TAF SITES. EXPECT LINGERING SHWRS BEHIND MAIN
CONVECTIVE LINE FOR AT LEAST A COUPLE OF HRS...WITH MVFR FOG INDUCED
VSBYS DEVELOPING ALSO. MVFR CEILINGS EXPECTED BY 20/15Z...WITH VFR
CEILINGS POSSIBLE 20/18Z AND AFTERWARDS.
&&
.PREV DISCUSSION.../ISSUED 200 PM CDT SUN APR 19 2015/
DISCUSSION...SURFACE MAP AT 18Z SHOWS A 1000 MB LOW CENTERED OVER
SOUTHERN ILLINOIS, WITH A WARM FROM SITUATED TO OUR NORTH, A
COLD FRONT STILL WEST OF THE MISSISSIPPI RIVER, AND A PRE-FRONTAL
TROUGH JUST NOW CROSSING THE TENNESSEE RIVER THAT IS PROVIDING THE
FOCUS FOR A DEVELOPING LINE OF CONVECTION. SATELLITE IMAGERY IS
STARTING TO SHOW SOME BREAKS IN THE CLOUDS, ESPECIALLY WEST OF
NASHVILLE. LAPS SOUNDING FOR BNA AT 18Z SHOWS WEAK INSTABILITY,
WITH A LIFTED INDEX OF -3.3 AND A CAPE OF 962 J/KG. ATMOSPHERE
REMAINS SUFFICIENTLY MOIST, WITH PRECIPITABLE WATER OF 1.44 INCHES
AND A K-INDEX OF 34. LATEST HRRR SHOWS SCATTERED CELLS ACROSS
MIDDLE TENNESSEE UNTIL A MORE ORGANIZED LINE OF CONVECTION COMES
THROUGH WITH THE COLD FRONT BETWEEN 04Z AND 09Z. GIVEN THE TIMING
OF THE FRONT, THE POTENTIAL FOR WIDESPREAD SEVERE STORMS APPEARS
LOW, ALTHOUGH MIDDLE TENNESSEE DOES REMAIN UNDER A SLIGHT RISK OF
SEVERE WEATHER TODAY AND TONIGHT, SO ISOLATED CASES OF SEVERE
ACTIVITY ARE STILL POSSIBLE. AFTER A FEW LINGERING SHOWERS ON
MONDAY, LOOK FOR A BRIEF RESPITE ON TUESDAY BEFORE THE NEXT COLD
FRONT DROPS SOUTHWARD THROUGH MIDDLE TENNESSEE WEDNESDAY AND
THURSDAY. GIVEN THAT THE UPPER FLOW ACROSS THE REGION WILL REMAIN
EITHER CYCLONIC OR ZONAL, WARM ADVECTION WILL BE HARD TO COME BY,
AND SO TEMPERATURES DURING THE NEXT 7 DAYS WILL REMAIN AT OR BELOW
NORMAL.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
530 PM CDT SAT APR 18 2015
.UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CURRENT REGIONAL
SFC OBS...SATELLITE...AND MOSAIC RADAR TRENDS ALONG WITH THE LATEST IN
SHORT RANGE MODEL CONSENSUS...THUS MAINTAINING ISO SHWRS/TSTMS THRU AT
LEAST THE MID EVENING HRS. BULK OF SHWR/TSTMS ACTIVITY SHOULD SPREAD FROM
THE SW TO THE NE ACROSS THE MID STATE AFTER MIDNIGHT.
&&
.PREV DISCUSSION.../ISSUED 351 PM CDT SAT APR 18 2015/
DISCUSSION...
AS AN UPPER TROUGH CENTERED OVER THE CENTRAL PLAINS MOVES EAST THIS
AFTERNOON AND OVERNIGHT IT WILL INFLUENCE SHOWERS AND THUNDERSTORMS
TO CONTINUE THEIR TREK NORTHWARD THROUGH MIDDLE TN. HRRR IS FORECASTING
SCATTERED AFTERNOON ACTIVITY TO MOVE INTO KENTUCKY AND ANOTHER
WAVE OF PRECIP TO SPREAD INTO MIDDLE TENNESSEE FROM THE SOUTH
BEFORE MIDNIGHT. PWAT VALUES WILL BE AROUND 1.5 INCHES FOR SEVERAL
HOURS OVERNIGHT TONIGHT. WITH THE GROUND ALREADY SATURATED FROM
THIS PAST WEEK`S RAINFALL...WE COULD SEE CREEKS AND STREAMS RISE
PRETTY QUICKLY DURING THE OVERNIGHT HOURS...WATCH FOR MINOR
FLOODING IN LOW LYING AREAS AND PONDING OF WATER ON ROADWAYS
OVERNIGHT. WHILE THERE MAY BE STORMS AROUND...NOT EXPECTING
ANYTHING STRONG OR SEVERE TONIGHT.
BETWEEN LATE SUNDAY MORNING AND EARLY AFTERNOON THE DEEPEST
MOISTURE WILL PUSH NORTH OF OUR AREA. LINGERING CLOUD
COVER...ESPECIALLY OVER THE NORTHEASTERN PORTION OF THE CWA MAY
INHIBIT INSTABILITY...BUT CLOUDS SHOULD BREAK UP ENOUGH DURING
THE AFTERNOON HOURS TO ALLOW FOR TEMPERATURES TO WARM INTO THE LOW
70S ALONG THE CUMBERLAND PLATEAU AND MID 70S ELSEWHERE. THIS
SHOULD BE WARM ENOUGH TO INITIATE ISOLATED TO SCATTERED STORMS
THROUGHOUT THE AFTERNOON. CURRENTLY SPC HAS THE MID-STATE IN A
SLIGHT RISK FOR SEVERE THUNDERSTORMS FOR SUNDAY AFTERNOON THROUGH
SUNDAY NIGHT. THE MAIN THREAT WITH ANY STORMS DURING THIS TIME
FRAME WILL BE DAMAGING WINDS AND HAIL. WE COULD SEE A COUPLE OF
ROUNDS OF THUNDERSTORMS OVERNIGHT SUNDAY NIGHT AHEAD OF A
SHORTWAVE AND ITS ASSOCIATED SURFACE LOW...WHICH STRENGTHEN OVER
SOUTHERN ILLINOIS AND HEAD NORTHEAST ON MONDAY.
THE FRONTAL PASSAGE ASSOCIATED WITH THE AFOREMENTIONED LOW WILL
OCCUR ON MONDAY AND WILL ALLOW FOR TEMPERATURES TO COOL INTO THE
40S OVERNIGHT MONDAY NIGHT. ALL PRECIP SHOULD PUSH EAST OF THE
TENNESSEE VALLEY TUESDAY NIGHT. A SURFACE HIGH MOVES IN ON TUESDAY
AND GIVES US A MUCH NEEDED DRY AND RELATIVELY COOL DAY WITH HIGH
TEMPERATURES IN THE MID 60S.
THE NEXT CHANCE OF PRECIP ENTERS THE FORECAST WEDNESDAY EVENING AS
A WEAK FRONT BRINGS A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH
THE AREA. COULD SEE A BREAK ON FRIDAY AS THAT MOISTURE PUSHES
SOUTH...THEN ANOTHER SURFACE LOW BRINGS ADDITIONAL THUNDERSTORM
CHANCES FRIDAY NIGHT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
351 PM CDT SAT APR 18 2015
.DISCUSSION...
AS AN UPPER TROUGH CENTERED OVER THE CENTRAL PLAINS MOVES EAST THIS
AFTERNOON AND OVERNIGHT IT WILL INFLUENCE SHOWERS AND THUNDERSTORMS
TO CONTINUE THEIR TREK NORTHWARD THROUGH MIDDLE TN. HRRR IS FORECASTING
SCATTERED AFTERNOON ACTIVITY TO MOVE INTO KENTUCKY AND ANOTHER
WAVE OF PRECIP TO SPREAD INTO MIDDLE TENNESSEE FROM THE SOUTH
BEFORE MIDNIGHT. PWAT VALUES WILL BE AROUND 1.5 INCHES FOR SEVERAL
HOURS OVERNIGHT TONIGHT. WITH THE GROUND ALREADY SATURATED FROM
THIS PAST WEEK`S RAINFALL...WE COULD SEE CREEKS AND STREAMS RISE
PRETTY QUICKLY DURING THE OVERNIGHT HOURS...WATCH FOR MINOR
FLOODING IN LOW LYING AREAS AND PONDING OF WATER ON ROADWAYS
OVERNIGHT. WHILE THERE MAY BE STORMS AROUND...NOT EXPECTING
ANYTHING STRONG OR SEVERE TONIGHT.
BETWEEN LATE SUNDAY MORNING AND EARLY AFTERNOON THE DEEPEST
MOISTURE WILL PUSH NORTH OF OUR AREA. LINGERING CLOUD
COVER...ESPECIALLY OVER THE NORTHEASTERN PORTION OF THE CWA MAY
INHIBIT INSTABILITY...BUT CLOUDS SHOULD BREAK UP ENOUGH DURING
THE AFTERNOON HOURS TO ALLOW FOR TEMPERATURES TO WARM INTO THE LOW
70S ALONG THE CUMBERLAND PLATEAU AND MID 70S ELSEWHERE. THIS
SHOULD BE WARM ENOUGH TO INITIATE ISOLATED TO SCATTERED STORMS
THROUGHOUT THE AFTERNOON. CURRENTLY SPC HAS THE MID-STATE IN A
SLIGHT RISK FOR SEVERE THUNDERSTORMS FOR SUNDAY AFTERNOON THROUGH
SUNDAY NIGHT. THE MAIN THREAT WITH ANY STORMS DURING THIS TIME
FRAME WILL BE DAMAGING WINDS AND HAIL. WE COULD SEE A COUPLE OF
ROUNDS OF THUNDERSTORMS OVERNIGHT SUNDAY NIGHT AHEAD OF A
SHORTWAVE AND ITS ASSOCIATED SURFACE LOW...WHICH STRENGTHEN OVER
SOUTHERN ILLINOIS AND HEAD NORTHEAST ON MONDAY.
THE FRONTAL PASSAGE ASSOCIATED WITH THE AFOREMENTIONED LOW WILL
OCCUR ON MONDAY AND WILL ALLOW FOR TEMPERATURES TO COOL INTO THE
40S OVERNIGHT MONDAY NIGHT. ALL PRECIP SHOULD PUSH EAST OF THE
TENNESSEE VALLEY TUESDAY NIGHT. A SURFACE HIGH MOVES IN ON TUESDAY
AND GIVES US A MUCH NEEDED DRY AND RELATIVELY COOL DAY WITH HIGH
TEMPERATURES IN THE MID 60S.
THE NEXT CHANCE OF PRECIP ENTERS THE FORECAST WEDNESDAY EVENING AS
A WEAK FRONT BRINGS A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH
THE AREA. COULD SEE A BREAK ON FRIDAY AS THAT MOISTURE PUSHES
SOUTH...THEN ANOTHER SURFACE LOW BRINGS ADDITIONAL THUNDERSTORM
CHANCES FRIDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 62 76 60 68 / 100 70 60 40
CLARKSVILLE 62 74 58 66 / 100 70 60 40
CROSSVILLE 61 71 59 67 / 100 80 60 60
COLUMBIA 62 75 60 67 / 100 60 60 40
LAWRENCEBURG 63 75 59 68 / 100 50 60 40
WAVERLY 62 75 59 69 / 100 60 60 30
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
11
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
855 AM EDT SAT APR 18 2015
.DISCUSSION...DENSE FOG IS SLOWING LIFTING ACROSS THE AREA THIS
MORNING...HOWEVER...WILL EXTEND ADVISORY UNTIL 14Z (10 AM ET).
MODELS...INCLUDING LATEST HRRR MODEL...SHOWS UPSLOPE FLOW INTO THE
SPINE OF SOUTHERN APPALACHIANS THIS AFTERNOON. MARGINAL INSTABILITY
WILL ALLOW SHOWERS AND ISOLATED THUNDERSTORMS TO DEVELOP ACROSS THE
MOUNTAINS...THEN SPREADING INTO THE VALLEY. BEST COVERAGE...DUE TO
BETTER INSTABILITY...WILL BE ACROSS THE CENTRAL AND SOUTHERN
MOUNTAINS AND SOUTHWEST NORTH CAROLINA. HAVE INCREASE CHANCES FOR
CONVECTION AREA-WIDE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 76 62 76 61 / 40 100 90 60
KNOXVILLE MCGHEE TYSON AIRPORT, TN 78 61 76 61 / 40 100 90 60
OAK RIDGE, TN 77 62 75 60 / 30 100 90 60
TRI CITIES AIRPORT, TN 80 58 75 56 / 30 70 90 60
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR CHEROKEE-
CLAY.
TN...DENSE FOG ADVISORY UNTIL 10 AM EDT /9 AM CDT/ THIS MORNING FOR
ANDERSON-BLEDSOE-BLOUNT SMOKY MOUNTAINS-BRADLEY-CAMPBELL-
CLAIBORNE-COCKE SMOKY MOUNTAINS-EAST POLK-GRAINGER-HAMBLEN-
HAMILTON-HANCOCK-HAWKINS-JEFFERSON-JOHNSON-KNOX-LOUDON-
MARION-MCMINN-MEIGS-MORGAN-NW BLOUNT-NORTH SEVIER-NORTHWEST
CARTER-NORTHWEST COCKE-NORTHWEST GREENE-NORTHWEST MONROE-
RHEA-ROANE-SCOTT TN-SEQUATCHIE-SEVIER SMOKY MOUNTAINS-
SOUTHEAST CARTER-SOUTHEAST GREENE-SOUTHEAST MONROE-SULLIVAN-
UNICOI-UNION-WASHINGTON TN-WEST POLK.
VA...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LEE-RUSSELL-
SCOTT-WASHINGTON-WISE.
&&
$$
AREA FORECAST DISCUSSION
NWS AMARILLO TX
521 PM CDT SAT APR 18 2015
.UPDATE...
WEST TEXAS MESONET AND SCHOOL NET OBSERVATIONS SHOW A CONTINUED
DECREASE IN SURFACE DEW POINTS AND VEERING OF SURFACE WINDS ACROSS
THE FAR EASTERN PORTION OF THE TEXAS PANHANDLE. SPC RAP MESOANALYSIS
HAS RESPONDED BY DEPICTING MUCH HIGHER LCL HEIGHTS THAT ARE LESS
FAVORABLE FOR TORNADOES. A MORE FAVORABLE ENVIRONMENT EXISTS FURTHER
EAST INTO OKLAHOMA WHERE SURFACE WINDS REMAINED BACKED AND AT LEAST
SHALLOW LOW LEVEL MOISTURE /DEW POINTS IN THE MID TO UPPER 50S/ IS
PRESENT. A FAIRLY POTENT VORT MAX IS MOVING ACROSS THE TEXAS
PANHANDLE NOW AS SEEN ON WATER VAPOR LOOP AND THIS MAY RESULT IN AN
UPTICK IN CONVECTION OVER THE NEXT COUPLE OF HOURS. HAIL AND WIND
ARE STILL POSSIBLE WITH THE STRONGEST STORMS AS ENOUGH INSTABILITY
REMAINS INTO EARLY EVENING. WILL CONTINUE TO MONITOR TRENDS IN THE
OBSERVATIONS...ESPECIALLY LATER THIS EVENING WHEN MIXING SUBSIDES
AND THE DRYLINE POSSIBLY SHIFTS WESTWARD SOME. THE BEST CHANCE OF
BETTER LOW LEVEL MOISTURE RETURNING TO THE FORECAST AREA WILL BE
ACROSS WHEELER AND COLLINGSWORTH COUNTIES.
BRB
&&
.PREV DISCUSSION... /ISSUED 221 PM CDT SAT APR 18 2015/
DISCUSSION...
EARLY THIS AFTERNOON A DEEP CLOSED LOW WAS SITUATED OVER EASTERN
COLORADO AND SLOWLY MOVING EAST. A BAND OF CLOUDS ASSOCIATED WITH A
RELATIVELY POTENT VORT LOBE ROTATING AROUND THE MID-UPPER LOW WAS
EVIDENT IN IR/VIS SATELLITE. SURFACE OBSERVATIONS SHOW LIGHT RAIN
BENEATH THIS BAND OF CLOUDS AT CLAYTON NEW MEXICO AND PRESUMABLY
FURTHER SOUTH-SOUTHWEST EAST OF TUCUMCARI INTO THE FAR WESTERN TEXAS
PANHANDLE WHERE LIGHT ECHOS WERE PRESENT ON REGIONAL RADAR MOSAIC.
FURTHER EAST ACROSS THE TEXAS AND OKLAHOMA PANHANDLE LOW CLOUDS HAVE
DIMINISHED AND/OR SHIFTED INTO OKLAHOMA AS SURFACE WINDS CONTINUE TO
VEER SLIGHTLY. SHALLOW LOW LEVEL MOISTURE SEEN ON 12Z KAMA SOUNDING
REMAINS ACROSS THE EASTERN PANHANDLES EAST OF A DIFFUSE DRYLINE.
THERE REMAINS SOME UNCERTAINTY ON THE POSITION OF THE DRYLINE THAT
IS EXPECTED TO SHARPEN THIS AFTERNOON AS DIABATIC HEATING/MIXING
COMMENCES. USING SHORT RANGE MODEL FORECAST SOUNDINGS AS GUIDANCE ON
THE DEPTH OF MOISTURE OFF THE CAPROCK AND ESPECIALLY FURTHER EAST
NEAR THE OKLAHOMA BORDER LEADS TO FAIRLY HIGH CONFIDENCE ON THE
PREVIOUS FORECAST WHICH RELEGATES ANY SUBSTANTIAL DEEP CONVECTION TO
NEAR OR JUST EAST OF THE OKLAHOMA STATE LINE LATER THIS AFTERNOON.
LOW LEVEL MOISTURE IS DEEPER FROM THERE EASTWARD INTO OKLAHOMA AND
THUS DRYLINE CIRCULATION THAT DEVELOPS STANDS A BETTER CHANCE AT
INITIATING CONVECTION THERE THAN WAS THE CASE FURTHER WEST
YESTERDAY. SO THROUGH THE LATE AFTERNOON AND EVENING THERE IS ONLY A
LOW PROBABILITY OF ISOLATED-SCATTERED CONVECTION ACROSS THE EXTREME
EASTERN PORTION OF THE PANHANDLES WITH BETTER CHANCES OUT OF THE
FORECAST AREA ACROSS WESTERN OKLAHOMA. IF THE ABOVE ASSESSMENT IS
MISPLACED SLIGHTLY EAST THAN ANY STORM THAT DOES DEVELOP ON OUR SIDE
OF THE STATE LINE WOULD HAVE THE POTENTIAL TO BECOME SEVERE DUE TO
MODERATE INSTABILITY AND SUFFICIENT DEEP LAYER SHEAR OF AROUND 30
KNOTS FOR STORM ORGANIZATION/PERSISTENCE. LARGE HAIL WOULD BE THE
PRIMARY THREAT INTO THE EVENING GIVEN STEEP MID LEVEL LAPSE RATES
OWING TO THE APPROACHING MID-UPPER LOW. WILL CONTINUE TO MONITOR
TRENDS IN SURFACE OBSERVATIONS AND DRYLINE EVOLUTION THROUGHOUT THE
AFTERNOON.
FURTHER WEST OF THE DRYLINE...DEEP MIXING WILL OCCUR GENERALLY EAST
OF THE AFOREMENTIONED BAND OF LOW-MID CLOUDS NOW ENTERING THE TEXAS
PANHANDLE. CU FIELD IS INCREASING IMMEDIATELY AHEAD OF THIS. BASES
SHOULD BECOME RELATIVELY HIGH AS MIXED LAYER DEEPENS THROUGH THE
AFTERNOON. WITH FORCING FROM PREVIOUSLY MENTIONED VORT LOBE
CONVECTION MAY BECOME DEEP ENOUGH FOR SHOWERS AND THUNDERSTORMS FOR
MUCH OF THE AREA LATER THIS AFTERNOON. IF CONVECTION BECOMES DEEP
ENOUGH FOR CHARGE SEPARATION AND LIGHTNING...LIMITED INSTABILITY
SHOULD PRECLUDE THE THREAT OF SEVERE THUNDERSTORMS. PROGNOSTICATIONS
FROM THE HI-RES CONVECTION ALLOWING GUIDANCE INCLUDING THE HRRR AND
TTU WRF SEEM TO LINE UP WELL WITH THE ABOVE THINKING.
AS THE MID-UPPER LOW CONTINUES TO SHIFT EAST A COLD FRONT WILL MOVE
THROUGH THE AREA TONIGHT. MODEL GUIDANCE IS IN AGREEMENT IN AN
EVOLUTION OF THE LOW INTO A MORE OPEN AND PROGRESSIVE WAVE THAT WILL
BE EAST OF THE AREA BY TOMORROW AFTERNOON. AN AREA OF MOISTURE ON
THE BACK SIDE OF THIS EVOLVING SHORTWAVE TROUGH FAVORABLY TIMED WITH
PEAK HEATING SHOULD BE ENOUGH FOR EXTENSIVE CUMULUS DEVELOPMENT
DURING THE AFTERNOON POSSIBLY ENOUGH FOR BROKEN SKY CONDITIONS
ESPECIALLY ACROSS THE EASTERN PORTION OF THE AREA. DEPTH OF
CONVECTION IN ROUGHLY THE NORTHEAST THIRD WILL NEED TO BE MONITORED
AS IT MAY BECOME SUFFICIENT FOR A FEW SHOWERS GIVEN RESIDUAL COOL MID
LEVEL TEMPERATURES AND RELATIVELY HIGH TQ INDEX VALUES. ADJUSTED LOW
POPS ON SUNDAY AFTERNOON TO EXTEND A BIT FURTHER SOUTH AND WEST TO
ACCOUNT FOR THIS.
EARLY NEXT WEEK A SPLIT UPPER FLOW PATTERN WILL EXIST WITH STRONG
PERIODICALLY PERTURBED WESTERLY SOUTHERN BRANCH JUST SOUTH OF US AND
NORTHWESTERLY NORTHERN BRANCH ACROSS THE CENTRAL PLAINS. MEAN
RIDGING WILL BE PRESENT OVER THE WESTERN STATES. GRADUALLY
INCREASING 500 MB HEIGHTS AND A SLIGHTLY MORE AMPLIFIED PATTERN WILL
EVOLVE THROUGH THE WEEK ESPECIALLY AS ANOTHER CLOSED LOW DEVELOPS
AND DEEPENS OVER THE SOUTHWESTERN CONUS BY THURSDAY. AS THIS MOVES
EAST THIS WILL PROBABLY RESULT IN ANOTHER CONVECTIVELY ACTIVE
PATTERN FOR THE LATTER HALF OF THE WEEK. AS IS TYPICALLY THE CASE AT
THAT TIME RANGE MODEL GUIDANCE DIFFERS IN TIMING AND AMPLITUDE BUT
THE SIGNAL IS THERE FOR A SCENARIO FAVORING A NORTH/WEST SURGE OF
LOW LEVEL MOISTURE AND FORCING FOR ASCENT RESULTING IN ABOVE CLIMO
PRECIPITATION PROBABILITIES AND THE POSSIBILITY OF SEVERE
THUNDERSTORMS BY MID AND ESPECIALLY LATE WEEK. EVEN BEFORE THEN
THERE WILL BE A FEW OPPORTUNITIES FOR PRECIPITATION EARLIER IN THE
WEEK AS DIFFICULT TO RESOLVE SMALL SHORTWAVE TROUGHS WITHIN MEAN
WEST-NORTHWESTERLY FLOW CROSS THE AREA. CONVECTION MAY EMANATE FROM
THE HIGHER TERRAIN OF COLORADO AND NEW MEXICO AND MOVE INTO THE
PANHANDLES LATE MONDAY AND AGAIN LATE TUESDAY...ALTHOUGH THIS
FORECAST WILL BE LESS DETERMINISTIC WITH TIMING OF HIGHER
PROBABILITIES OF PRECIPITATION AND MORE BROAD BRUSH GIVEN INHERENT
UNCERTAINTIES OF THIS TYPE PATTERN.
BRB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
15/17
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
445 PM CDT SAT APR 18 2015
.DISCUSSION...
SENT OUT AN UPDATED FORECAST PACKAGE AND RAISED POPS AREA WIDE DUE
TO ONGOING/DEVELOPING CONVECTION ACROSS THE COASTAL COUNTIES AND
OFF THE COAST...AND FOR DEVELOPING STORMS OUT WEST THAT THE MODELS
HAVE MOVING INTO THE AREA THIS EVENING. SOME OF THE STORMS COULD
HAVE THE POTENTIAL TO BECOME STRONG OR SEVERE...WITH DAMAGING WINDS...
LARGE HAIL...AND LOCALLY HEAVY RAINFALL THE PRIMARY SEVERE WEATHER
THREATS. 42
&&
.PREV DISCUSSION... /ISSUED 340 PM CDT SAT APR 18 2015/
DISCUSSION...
THE UPPER LOW OVER EASTERN CO WILL OPEN UP AND SHEAR OUT OVER THE
PLAINS DURING THE NEXT DAY OR TWO. A COUPLE OF SHORTWAVE TROUGHS
MOVING OVERHEAD WILL BRING SCATTERED THUNDERSTORMS ACROSS SE TX
DURING A COUPLE OF EPISODES TONIGHT...THE FIRST DURING THE LATE
AFTERNOON AND EARLY EVENING AND THE SECOND FROM LATE EVENING
INTO THE OVERNIGHT PERIOD. CANNOT RULE OUT THE POSSIBILITY OF AN
ISOLATED OR STRONG THUNDERSTORM. ALTHOUGH THE MAIN STORM ACTION
WELL OFFSHORE OF THE COAST HAS BEEN STEALING MOST OF THE INFLOW
MOISTURE...THE LATEST SATELLITE TRENDS INDICATE THAT THE STORMS
NEAR MATAGORDA BAY WERE BEGINNING TO EXHIBIT COOLING CLOUD TOPS.
THERE IS ALSO A SLIGHT CHANCE THAT THE STORMS OVER THE FAR
SOUTHWESTERN SET OF COUNTIES MAY CONTAIN LOCALLY HEAVY RAINFALL
DURING THE REMAINING AFTERNOON HOURS. THE SECOND ROUND OF STORMS
WAS BEING FORECASTED BY THE HRRR AND TEXAS TECH WRF TO MOVE OVER
THE NORTHWESTERN AND NORTHERN SET OF COUNTIES BETWEEN ABOUT 9 PM
AND 2 AM OR SO. RAP FORECAST SOUNDING SHOW THE POTENTIAL FOR
ISOLATED STRONG OR SEVERE STORMS WITH THESE AS WELL.
HIGH PRESSURE SHOULD THEN BUILD OVERHEAD SUNDAY AND MONDAY AND
LOWER THE RAIN CHANCES. BOTH THE GFS AND ECMWF AGREE WITH ONSHORE
WINDS AND RAIN CHANCES RETURNING BY WEDNESDAY.
MARINE...
AN UPPER LEVEL DISTURBANCE WILL GENERATE SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS ACROSS THE COASTAL WATERS THIS EVENING.
SOME STORMS COULD BE STRONG. OTHERWISE...ONSHORE FLOW WILL PERSIST
THROUGH SUNDAY. A COLD FRONT WILL PUSH OFF THE COAST SUNDAY NIGHT
WITH MODERATE OFFSHORE WINDS IN ITS WAKE. WINDS WILL DIMINISH AND
VEER BACK TO THE SOUTHEAST BY LATE TUESDAY NIGHT AS HIGH PRESSURE
PUSHES OFF TO THE EAST. 47
PREV DISCUSSION... /ISSUED 1248 PM CDT SAT APR 18 2015/
AVIATION...
SAT IMAGERY SUGGESTS INLAND PORTIONS OF SE TX SHOULD START SEEING
SOME INTERMITTENT BREAKS OF SUN. ELSEWHERE...EXPECT TO SEE
IMPROVING CIG HEIGHTS IN THE NEXT COUPLE HOURS. THERE IS A SFC
BOUNDARY NEAR THE COAST...SO ADDITIONAL HEATING ALONG WITH
APPROACHING S/W FROM MID TX COAST SHOULD ALLOW FOR AT LEAST SOME
SCT TSRA TO DEVELOP THIS AFTN - ESP SOUTH OF A COLUMBUS-LIBERTY
LINE. (THIS IS ROUGHLY THE SAME LOCATIONS THAT SAW SOME SIG WX
YDAY SO WILL NEED TO KEEP A CLOSE EYE ON THINGS.) AREAS FURTHER N
WILL NEED TO KEEP AN EYE ON NW TX. MODELS ARE POINTING TOWARD A
DEVELOPING LINE OF SHRA/TSRA OUT THERE THIS AFTN...POSSIBLY MAKING
IT ESE TOWARD SE TX LATE EVNG & OVERNIGHT. WILL SEE HOW THIS ALL
PLAYS OUT, BUT WENT AHEAD AND THREW THE POTENTIAL OF THIS
OCCURRING IN THE 9-2AM TIMEFRAME IN THE CLL, UTS, CXO TAFS.
CONSIDERABLE UNCERTAINTY IN THIS ATTM BUT FEEL IT`S ENOUGH TO
BEGIN MENTIONING. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 63 85 56 75 54 / 50 20 10 10 20
HOUSTON (IAH) 64 85 61 78 57 / 50 20 20 10 10
GALVESTON (GLS) 69 81 66 77 66 / 50 20 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...42
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS EL PASO TX/SANTA TERESA NM
251 PM MDT SAT APR 18 2015
.SYNOPSIS...
WINDS WILL TAPER OFF AFTER SUNSET THIS EVENING AS TEMPERATURES
COOL ACROSS THE BORDERLAND. DAYTIME CLOUDS WILL DISSOLVE LEAVING
SKIES MOSTLY CLEAR OVERNIGHT. SUNDAY WILL BE GENERALLY DRY AND
SUNNY AS A LOW PRESSURE SYSTEM BEGINS TO EXIT EAST. TEMPERATURES
WILL WARM ABOUT 5 DEGREES AND WINDS WILL BE NOTICEABLY LIGHTER.
JUST A BIT OF LINGERING MOISTURE ALOFT MAY ALLOW FOR A STRAY
ELEVATED THUNDERSTORM OVER THE MOUNTAINS IN THE AFTERNOON HOURS.
THE WEATHER REPEATS MONDAY. TUESDAY ONWARD STRONGER WINDS RETURN FOR
EACH AFTERNOON WITH THURSDAY LOOKING THE STRONGEST FOR THE WEEK.
GENERALLY DRY CONDITIONS LOOK TO HOLD FOR THE WEEK AHEAD BUT A
PACIFIC LOW PRESSURE SYSTEM DOES TRACK ACROSS THE REGION THURSDAY
TO BRING INCREASED CLOUDS...AND MAYBE A STRAY SHOWER OR STORM.
&&
.DISCUSSION...
LARGE UPPER-LEVEL LOW PRESSURE SYSTEM SPINS OVER E CO. IT IS
S-L-O-W-L-Y DRIFTING EAST TOWARDS KS. WE SIT UNDER THE SOUTHERN
PERIPHERY OF THIS SYSTEM WITH A BIT OF MID-LEVEL MOISTURE AND
LARGE-SCALE WEAK FORCING ALOFT. THE RESULT THUS FAR TODAY HAS BEEN
TO ROTATE A NICE CU-FIELD OVER THE NORTHERN ZONES FROM THE NW.
HOWEVER STILL NO ENHANCED RADAR ECHOS OR LIGHTNING. MOST OF THE
CU IS QUITE FLAT. VERY REASONABLE GIVEN THE ACTUAL 12Z SOUNDING
AND THE PROG 18-00Z SOUNDINGS. SHOULD BE A SHALLOW LAYER OF
MOISTURE WITH PW`S AT 1/3". MODELS DO SHOW THE ATMOSPHERE LEANING
TOWARD MARGINALLY UNSTABLE WITH LI`S NEAR 0 AND CAPE LESS THAN 100
J/KG. BOTTOM LINE IS THAT STORM POTENTIAL IS THERE...BUT IT IS
MARGINAL WITH ONLY ISOLATED AND WEAK STORMS. BOTH THE HRRR AND WRF
MODELS SHOW LATE AFTN/EARLY EVE STORMS OVER SIERRA/OTERO COUNTIES
AS DO THE GFS AND NAM. THUS SLIGHT CHANCE WORDING IN THE FORECAST
FOR THOSE AREAS FOR THE EVENING HOURS TONIGHT. THREATS/IMPACT WOULD
BE STRONG OUTFLOW WIND/LOW VSBY WITH DUST.
FOR SUNDAY IT APPEARS WE WILL SEE VERY SIMULAR WEATHER CONDITIONS
WITH REGARDS TO TODAY. WITH THE LOW EXITING AND HEIGHTS AND
THICKNESSES RISING ALONG WITH LIGHTER WINDS WE SHOULD GAIN ABOUT
5-7 DEGREES ON TEMPS SUNDAY. SUNDAY`S MOISTURE PROFILE RESEMBLES
TODAY`S WITH JUST A THIN LAYER OF MODERATELY MOIST AIR ALOFT. WE
WILL CONTINUE TO SEE VERY MINOR (WEAK) IMPULSES ALOFT TRACK OVER
IN WNW FLOW. WITH OROGRAPHICS WE COULD SEE A FEW MOUNTAIN
STORMS...BUT AGAIN ISOLATED AND WEAK. THE LOWLANDS SHOULD STAY
DRY. LIGHTER WINDS WILL BE THE BIGGER DEAL AS WINDS DROP BELOW THE
BREEZY CATEGORY OF 15 TO 25 MPH.
TUESDAY THE PATTERN BECOMES MORE SOUTHWEST ORIENTED AND THAT MEANS
WIND WILL BE ON THE INCREASE AGAIN. A DEEPENING PACIFIC TROUGH TO
OUR WEST AND A DEEPENING SURFACE TROUGH TO OUR EAST WILL TIGHTEN
GRADIENTS AND INCREASE WINDS. TUESDAY AND WEDNESDAY WILL BE DRY...
A FEW DEGREES WARMER THAN NORMAL...AND BREEZY.
THURSDAY THE WEST COAST LOW PRESSURE SYSTEM ARRIVES WITH WHAT
APPEARS TO BE MINIMAL MOISTURE. DESPITE APPEARING TO STRUGGLE WITH
IT THE MODELS DO SPIT OUT SOME QPF AND THUS WHAT LOOKS TO BE
ISOLATED SHOWERS AND THUNDERSTORMS. FOR NOW WE ARE IGNORING THE
SLIGHT PCPN POTENTIAL IN FAVOR WHAT WHAT SHOULD BE A LARGER
IMPACT...WIND. THURSDAY LOOKS WINDY BUT CLOUDS MAY TEMPER THE
SPEEDS A BIT.
FRIDAY THE PACIFIC STORM SYSTEM PASSES AND A MODERATELY WEAK
PACIFIC FRONT PUSHES IN TO BRING A SMALL BIT OF COOLING AND
LIGHTER WINDS. MODELS SUGGEST A SHORT WAVE RIDGE TO BUILD OVER THE
AREA SATURDAY ALLOWING TEMPS TO WARM WITH DRY CONDITIONS.
14-BIRD
&&
.AVIATION...VALID 19/00Z-20/00Z...
SCT-BKN CU FIELDS WILL PERSIST INTO THE EARLY EVENING HOURS
GENERALLY NORTH OF A SVC-LRU LINE...WITH BASES RUNNING BETWEEN 9-10K
FEET. A FEW ISOLATED SHOWERS MAY AFFECT AREAS NORTH OF TCS.
ELSEWHERE...MOSTLY CLEAR SKIES WILL PREVAIL. WEST TO NORTHWEST
WINDS WILL RANGE 15-20 KNOTS WITH GUSTS 25-30 KNOTS...WITH A FEW
HIGHER GUSTS POSSIBLE IN SW NEW MEXICO. WINDS WILL DIMINISH FAIRLY
QUICKLY AFTER SUNSET. EXPECT SIMILAR CONDITIONS TOMORROW WITH LOWER
WIND SPEEDS. A FEW ISOLATED CONVECTIVE SHOWERS OR EVEN A
THUNDERSTORM WILL AFFECT THE AREA TOMORROW...FAVORING AREAS NORTH OF
AN LSB-LRU LINE.
25-HARDIMAN
&&
.FIRE WEATHER...
WINDS WILL CONTINUE TO SLOWLY INCREASE OVER THEN NEXT FEW HOURS
DUE TO A STRONG UPPER LOW OVER COLORADO AND AN INCREASINGLY
STRONG PRESSURE GRADIENT. RH VALUES HAVE DROPPED INTO THE LOW AND
MID TEENS. CURRENT RED FLAG WARNING LOOKS GOOD AND WILL CONTINUE
THROUGH 8 PM. THE UPPER LOW WILL MOVE EAST INTO THE PLAINS
TOMORROW...WHILE A WEAK BACKDOOR COLD FRONT STALLS OUT OVER THE
AREA. A SECONDARY UPPER LEVEL DISTURBANCE AND THIS FRONT WILL
BRING A SLIGHT CHANCE FOR THUNDERSTORMS TO THE HIGHER TERRAIN
AREAS SUNDAY AFTERNOON AND EVENING. LIGHTER WINDS WILL PREVAIL
EARLY NEXT WEEK...WITH INCREASING SOUTHWEST FLOW BEYOND WEDNESDAY.
25-HARDIMAN
&&
.PRELIMINARY POINT TEMPS/POPS...
EL PASO 52 80 54 82 55 / 0 0 0 0 0
SIERRA BLANCA 46 76 49 78 50 / 0 0 0 0 0
LAS CRUCES 45 78 48 79 48 / 0 0 0 0 0
ALAMOGORDO 45 76 49 78 49 / 0 10 10 0 0
CLOUDCROFT 34 56 36 58 39 / 10 10 10 10 0
TRUTH OR CONSEQUENCES 46 76 48 78 48 / 0 10 10 0 0
SILVER CITY 40 71 43 72 43 / 0 0 0 0 0
DEMING 42 80 44 80 45 / 0 0 0 0 0
LORDSBURG 40 79 43 80 43 / 0 0 0 0 0
WEST EL PASO METRO 52 80 55 81 55 / 0 0 0 0 0
DELL CITY 46 79 50 80 50 / 0 0 0 0 0
FORT HANCOCK 48 80 52 82 52 / 0 0 0 0 0
LOMA LINDA 48 73 50 75 52 / 0 0 0 0 0
FABENS 48 80 51 81 51 / 0 0 0 0 0
SANTA TERESA 47 80 50 80 50 / 0 0 0 0 0
WHITE SANDS HQ 50 77 53 79 53 / 0 0 0 0 0
JORNADA RANGE 40 78 44 79 44 / 0 0 0 0 0
HATCH 44 79 46 80 46 / 0 0 0 0 0
COLUMBUS 47 78 50 79 50 / 0 0 0 0 0
OROGRANDE 48 77 52 78 51 / 0 0 0 0 0
MAYHILL 39 64 39 66 43 / 10 10 10 0 0
MESCALERO 38 63 40 66 41 / 10 10 10 0 0
TIMBERON 39 64 41 66 42 / 10 10 10 0 0
WINSTON 36 69 39 72 39 / 10 10 10 0 0
HILLSBORO 42 75 44 77 45 / 0 10 10 0 0
SPACEPORT 41 78 44 79 44 / 0 0 10 0 0
LAKE ROBERTS 37 69 39 71 39 / 10 10 10 0 0
HURLEY 39 73 42 74 42 / 0 0 0 0 0
CLIFF 39 78 40 79 41 / 0 0 0 0 0
MULE CREEK 33 75 37 76 37 / 0 0 0 0 0
FAYWOOD 41 74 44 75 44 / 0 0 0 0 0
ANIMAS 44 79 47 79 47 / 0 0 0 0 0
HACHITA 42 79 45 80 45 / 0 0 0 0 0
ANTELOPE WELLS 42 78 46 79 46 / 0 0 0 0 0
CLOVERDALE 41 74 44 75 44 / 0 0 0 0 0
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR NMZ111-112.
TX...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR TXZ055-056.
&&
$$
14/25
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
340 PM CDT SAT APR 18 2015
.DISCUSSION...
THE UPPER LOW OVER EASTERN CO WILL OPEN UP AND SHEAR OUT OVER THE
PLAINS DURING THE NEXT DAY OR TWO. A COUPLE OF SHORTWAVE TROUGHS
MOVING OVERHEAD WILL BRING SCATTERED THUNDERSTORMS ACROSS SE TX
DURING A COUPLE OF EPISODES TONIGHT...THE FIRST DURING THE LATE
AFTERNOON AND EARLY EVENING AND THE SECOND FROM LATE EVENING
INTO THE OVERNIGHT PERIOD. CANNOT RULE OUT THE POSSIBILITY OF AN
ISOLATED OR STRONG THUNDERSTORM. ALTHOUGH THE MAIN STORM ACTION
WELL OFFSHORE OF THE COAST HAS BEEN STEALING MOST OF THE INFLOW
MOISTURE...THE LATEST SATELLITE TRENDS INDICATE THAT THE STORMS
NEAR MATAGORDA BAY WERE BEGINNING TO EXHIBIT COOLING CLOUD TOPS.
THERE IS ALSO A SLIGHT CHANCE THAT THE STORMS OVER THE FAR
SOUTHWESTERN SET OF COUNTIES MAY CONTAIN LOCALLY HEAVY RAINFALL
DURING THE REMAINING AFTERNOON HOURS. THE SECOND ROUND OF STORMS
WAS BEING FORECASTED BY THE HRRR AND TEXAS TECH WRF TO MOVE OVER
THE NORTHWESTERN AND NORTHERN SET OF COUNTIES BETWEEN ABOUT 9 PM
AND 2 AM OR SO. RAP FORECAST SOUNDING SHOW THE POTENTIAL FOR
ISOLATED STRONG OR SEVERE STORMS WITH THESE AS WELL.
HIGH PRESSURE SHOULD THEN BUILD OVERHEAD SUNDAY AND MONDAY AND
LOWER THE RAIN CHANCES. BOTH THE GFS AND ECMWF AGREE WITH ONSHORE
WINDS AND RAIN CHANCES RETURNING BY WEDNESDAY.
40
&&
.MARINE...
AN UPPER LEVEL DISTURBANCE WILL GENERATE SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS ACROSS THE COASTAL WATERS THIS EVENING.
SOME STORMS COULD BE STRONG. OTHERWISE...ONSHORE FLOW WILL PERSIST
THROUGH SUNDAY. A COLD FRONT WILL PUSH OFF THE COAST SUNDAY NIGHT
WITH MODERATE OFFSHORE WINDS IN ITS WAKE. WINDS WILL DIMINISH AND
VEER BACK TO THE SOUTHEAST BY LATE TUESDAY NIGHT AS HIGH PRESSURE
PUSHES OFF TO THE EAST. 47
&&
.PREV DISCUSSION... /ISSUED 1248 PM CDT SAT APR 18 2015/
AVIATION...
SAT IMAGERY SUGGESTS INLAND PORTIONS OF SE TX SHOULD START SEEING
SOME INTERMITTENT BREAKS OF SUN. ELSEWHERE...EXPECT TO SEE
IMPROVING CIG HEIGHTS IN THE NEXT COUPLE HOURS. THERE IS A SFC
BOUNDARY NEAR THE COAST...SO ADDITIONAL HEATING ALONG WITH
APPROACHING S/W FROM MID TX COAST SHOULD ALLOW FOR AT LEAST SOME
SCT TSRA TO DEVELOP THIS AFTN - ESP SOUTH OF A COLUMBUS-LIBERTY
LINE. (THIS IS ROUGHLY THE SAME LOCATIONS THAT SAW SOME SIG WX
YDAY SO WILL NEED TO KEEP A CLOSE EYE ON THINGS.) AREAS FURTHER N
WILL NEED TO KEEP AN EYE ON NW TX. MODELS ARE POINTING TOWARD A
DEVELOPING LINE OF SHRA/TSRA OUT THERE THIS AFTN...POSSIBLY MAKING
IT ESE TOWARD SE TX LATE EVNG & OVERNIGHT. WILL SEE HOW THIS ALL
PLAYS OUT, BUT WENT AHEAD AND THREW THE POTENTIAL OF THIS
OCCURRING IN THE 9-2AM TIMEFRAME IN THE CLL, UTS, CXO TAFS.
CONSIDERABLE UNCERTAINTY IN THIS ATTM BUT FEEL IT`S ENOUGH TO
BEGIN MENTIONING. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 63 85 56 75 54 / 40 20 10 10 20
HOUSTON (IAH) 64 85 61 78 57 / 30 20 20 10 10
GALVESTON (GLS) 69 81 66 77 66 / 30 20 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...40
AVIATION/MARINE...47
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
255 PM CDT SAT APR 18 2015
.SHORT TERM.../NOW THROUGH SUNDAY NIGHT/...A LOW PRESSURE SYSTEM
CENTERED OVER EASTERN COLORADO IS MAINTAINING A BROAD AREA OF
DIFFLUENT FLOW ALOFT OVER SOUTH CENTRAL TEXAS. ALSO ...A VERY
ACTIVE SUB TROPICAL JET WITH SHORTWAVES WITHIN THE FLOW IS MOVING
ACROSS SOUTH TX UNDERNEATH THIS LOW. THIS WILL CONTINUE TO PRODUCE
NUMEROUS SHOWERS AND THUNDERSTORMS ALONG THE LOWER TEXAS GULF
WATERS NORTHEAST INTO THE NORTHWEST GULF COAST. THERE IS AN AREA
OF CONVECTION DEVELOPING ALONG A STATIONARY FRONT WHICH IS
INTERACTING WITH PLENTY OF DEEP LAYER MOISTURE AND INSTABILITY
POOLED ALONG IT. NEAR THE SURFACE DEW POINTS RANGE FROM 70 TO 75
DEGREES AND PRECIPITABLE WATER VALUES IN THE LAST KBRO 12Z
SOUNDING SHOWS 1.96 INCHES AND THE LATEST RAP MODEL RUN SHOWS
PWATS OF 1.5 TO 1.9 INCHES ESPECIALLY FROM HIDALGO COUNTY
NORTHEAST AND EAST TOWARDS THE COAST. IN ADDITION...THE A SLIGHT
BREAK IN THE CLOUDS IS ALLOWING FOR TEMPS TO WARM UP FOR THE NEXT
FEW HOURS RESULTING IN INCREASE INSTABILITY ACROSS THE AREA. THIS
WILL RESULT IN A CONTINUATION OF THE CONVECTION IN THE LATE
AFTERNOON THROUGH THE OVERNIGHT HOURS THROUGH MIDNIGHT. THE
CONVECTION WILL ALSO BE ENHANCE ALONG THE SIERRA MADRE AND MOVE
NORTHEAST WHICH WILL MAKE ITS WAY INTO STARR AND HIDALGO COUNTY
LATE EVENING INTO THE OVERNIGHT. THE MAIN THREAT WITH THESE STORMS
WILL BE VERY HEAVY DOWNPOURS PRODUCING FLOODING...STRONG DAMAGING
WINDS...HAIL AND FREQUENT CG LIGHTNING. INTO SUNDAY THE UPPER
LEVEL JET WILL MAKE ITS WAY INTO SOUTH TEXAS PROVIDING SUPPORT FOR
SOME CONVECTION TO DEVELOP SUNDAY AFTERNOON. EXPECT THE BEST
POTENTIAL TO REMAIN ALONG THE COAST DUE TO THE INSTABILITY IN THE
AREA. EXPECT A FEW OF THE STORMS TO BECOME SEVERE. THE CLOSED LOW
BECOMES AN OPEN WAVE AS IT MOVES NORTHEAST INTO THE GREAT LAKES
SUNDAY NIGHT PUSHING A COLD FRONT BEHIND IT ALONG THE CENTRAL
PLAINS. THE CONVECTION WILL BE ENHANCE EVEN MORE OVERNIGHT SUNDAY
ASSOCIATED TO THE BOUNDARY AS THE FRONT APPROACHES THE AREA. THE
FRONT WILL ARRIVED BY THE END OF THE SHORT TERM OVER THE NORTHERN
RANCHLANDS EARLY MONDAY MORNING.
.LONG TERM.../MONDAY THROUGH SATURDAY/...THE CLOSED LOW THAT
HAS BEEN PLAUGING THE REGION WITH INTERMITTENT THUNDERSTORMS FOR
THE LAST SEVERAL DAYS OPENS UP AND MERGES WITH A SHARP SHORTWAVE
TROUGH UPPER TROUGH MOVING OUT OF CANADA. THE RESULT WILL BE A
LARGE SCALE UPPER TROUGH DEVELOPING MONDAY INTO TUESDAY FROM THE
NORTHERN PLAINS TO THE MIDWEST EXTENDING SOUTH INTO THE GULF
SOUTH. THIS SENDS A COLD FRONT THROUGH SOUTH TEXAS SUNDAY NIGHT
MOVING OFFSHORE THE LOWER TEXAS COAST AS EARLY AS SUNRISE MONDAY.
MODELS ARE IN GOOD AGREEMENT AND REMAIN VERY CONSISTENT WITH THE
EVOLUTION OF THE UPPER LEVEL AND SURFACE FEATURES. MODERATE TO
HIGH CONFIDENCE IN THE FORECAST THROUGH TUESDAY MAINTAINS A
LOWERING OF TEMPERATURES AND HIGHER CHANCES OF RAINFALL. THE
COOLING OF THE LOWER ATMOSPHERE, LOWER LAPSE RATES, WEAKENING
INSTABILITY WILL LIMIT THE THUNDERSTORM INTENSITY AND SEVERE
WEATHER PROBABILITIES GO WAY LOW. GFS MODEL SOUNDING CONTINUE TO
INDICATE THE BEST CHANCE OF THUNDER MONDAY MORNING AS THE FRONTAL
BOUNDARY PASSES THROUGH BUT AS THE COOLER SURFACE AIR SETTLES IN
THE INSTABILITY QUICKLY WEAKENS. ANY THUNDERSTORMS THAT LINGER
INTO THE MONDAY AFTERNOON AND EVENING WILL BE ELEVATED.
AS WE MOVE INTO TUESDAY AND THE REST OF THE WEEK THE FRONT
INITIALLY REMAINS STATIONARY NEAR OR JUST SOUTH OF THE REGION
KEEPING A MOIST EASTERLY FLOW AND POSSIBLY THE HIGHEST CHANCE OF
RAIN. BOTH GFS AND ECMWF INDICATE ON AVERAGE THAT TUESDAY WILL
HAVE THE BEST COVERAGE OF RAIN. THIS WILL ALSO KEEP TEMPERATURES
BELOW NORMAL.
AFTER TUESDAY FORECAST TRENDS DOWNWARD ON THE RAIN AND UP
WITH THE TEMPERATURES. THE FRONT EVENTUALLY DISSIPATES OR MOVES
BACK NORTH AS SHORTWAVE RIDGING BUILDS OVER WESTERN TEXAS WITH THE
NEXT UPPER TROUGH APPROACHING THE PACIFIC COAST. GFS AND ECMWF DO
LITTLE WITH THIS TROUGH AND IT LOOKS MUCH WEAKER THEN THE LAST FEW
TROUGHS. SOME PERTURBATIONS DO ADVANCE THROUGH THE TROUGH AND
RIDE ALONG STOUT SOUTHWESTERLY UPPER JET AND MAY SPARK SOME
AFTERNOON CONVECTION OVER THE SIERRA MADRE AND THEN DRIFT INTO OUR
CWA EACH AFTERNOON AND EVENING. THIS WILL BE INDICATED BY LOW
GRADE POPS EACH LATE DAY AND EVENING.
&&
.MARINE...NOW THROUGH SUNDAY NIGHT...THE SOUTHEAST WINDS WILL
REMAIN LIGHT TO VARIABLE WITH LOW SEAS ACROSS THE GULF WATERS.
THE MAIN CONCERNED THROUGH THE SHORT TERM WILL CONTINUE TO BE THE
CONVECTION OVER THE GULF. THERE IS ENOUGH INSTABILITY IN THE AREA
FROM A STATIONARY BOUNDARY PARALLEL TO THE COAST THAT WILL ENHANCE
MORE CONVECTION INCREASING LATE THIS AFTERNOON AND CONTINUE
OVERNIGHT. SUNDAY...THE POTENTIAL FOR CONVECTION WILL BEGIN TO
DEVELOP IN THE AFTERNOON AND CONTINUE OVERNIGHT AS A COLD FRONT IS
EXPECTED TO ARRIVED EARLY MONDAY INCREASING THE CHANCE OF RAIN
EVEN MORE AND SHIFTING WINDS NORTHERLY.
MONDAY THROUGH THURSDAY...COLD FRONT STILL ON TAP FOR EARLY
MONDAY AS HIGH PRESSURE BUILDS DOWN THE CENTRAL PLAINS AS A MID
LEVEL TROUGH DEEPENS INTO THE GULF SOUTH STATES. NORTHEAST WINDS
INCREASE APPROACHING SMALL CRAFT ADVISORY CONDITIONS MONDAY
AFTERNOON. SEAS TO RESPOND AND BUILD UPWARDS TO 6 FEET BY MONDAY
NIGHT. MODERATE NORTHEAST TO EAST WINDS PERSIST TUESDAY AS THE
FRONT BECOMES STATIONARY AND HIGH PRESSURE EXPANDS OVER THE
CENTRAL GULF. A RETURN TO SOUTHEAST WINDS WEDNESDAY WITH A GRADUAL
INCREASE THROUGH THE END OF THE WEEK IS EXPECTED. SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS MONDAY AND TUESDAY WITH
DECREASING COVERAGE MID TO LATE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 72 86 72 77 / 20 20 30 40
BROWNSVILLE 71 87 72 78 / 20 40 30 50
HARLINGEN 71 90 71 80 / 20 40 40 50
MCALLEN 70 92 72 80 / 20 30 30 50
RIO GRANDE CITY 68 94 71 80 / 20 20 30 40
SOUTH PADRE ISLAND 72 79 72 76 / 20 20 30 40
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
67/59
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
227 PM CDT Sat Apr 18 2015
.UPDATE...
The Storm Prediction Center has just issued Severe Thunderstorm
Watch number 72, and it covers all of West Central Texas. So, we
just sent an update to our Zone forecast to include a watch
headline for all of our counties.
&&
.PREV DISCUSSION... /ISSUED 1249 PM CDT Sat Apr 18 2015/
AVIATION...
/18Z TAFS/
Expect VFR conditions to dominate for the next 24 hours and
thunderstorms this afternoon and evening. Thunderstorms will
likely impact Sonora, Brady, and Junction this afternoon and
evening.
PREV DISCUSSION... /ISSUED 631 AM CDT Sat Apr 18 2015/
AVIATION...
/12Z TAFS/
Two upper level disturbance will bring a round of storms to most
TAF sites this morning and again this afternoon. Latest radar data
is showing an area of storms moving east and northeast towards
KSOA and KJCT and could reach those sites between 12Z and 15Z.
Main impacts will be gusty winds, brief heavy rain, lightning and
low visibilities. The IFR Cigs should gradually improve to VFR shortly
after 15Z. The next round of storms may form along the dryline
after 18Z at KSOA, KBBD and KJCT. A few of these may become severe
and produce large hail, damaging winds and very heavy rainfall.
PREV DISCUSSION... /ISSUED 420 AM CDT Sat Apr 18 2015/
SHORT TERM...
(Today and Tonight)
There is a threat for severe thunderstorms across the eastern half
of West Central Texas today as an upper level trough associated with
the upper low near the Four Corners moves across the region. The
main threats will be large hail and damaging winds. SPC has placed
much of the area east of the dryline in a slight risk for severe
thunderstorms today.
Latest radar is showing showers developing across the mountains in
northern Mexico, south of Sanderson, in association with the next
approaching shortwave as can be seen on water vapor satellite
imagery. This could bring a round of showers and thunderstorms to
West Central Texas this morning before the main upper trough moves
across later this afternoon.
The dryline is forecast to move east today as the RUC model progs
this front from Haskell to just east of San Angelo to Sonora by
early evening. This dryline should trigger scattered thunderstorms
this afternoon as the following ingredients come together: dewpoints
ranging from the upper 50s to the lower 60s, moderate 0-6km shear,
MU CAPE Values 1500-2000 J/KG, a weak capping inversion, approaching
upper trough and a right rear entrance region of the southern stream
upper level jet flowing across the area. These parameters should
set the stage for the development of a few supercells today,
resulting in large hail and damaging winds. These storms may
continue into the early evening hours before dissipating.
Highest Pops were placed across the Northwest Hill Country extending
north to Brownwood. Went closer to the warmer MAV MOS for
temps as the dry warm air invades the western part of the region
today.
26
LONG TERM...
(Sunday through Friday)
Cold front will move through Sunday. Dry southwest to west winds
ahead of the front will not only preclude rain chances, but also
give a boost to temperatures, being downslope compression. Still,
cold advection will bring cooler temperatures Sunday, with highs
in the 70s.
Isolated dryline thunderstorms possible mid and late week. West
Central Texas will be under a broad upper ridge, so widespread
showers or thunderstorms not expected. Could see a few highs
approach 90s, especially Wednesday and Thursday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 54 77 46 72 51 / 20 5 5 5 5
San Angelo 54 82 48 74 53 / 10 5 5 5 10
Junction 55 85 50 74 54 / 30 5 5 5 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
223 PM CDT SAT APR 18 2015
.UPDATE...
TO ISSUE SEVERE THUNDERSTORM WATCH 72. THUNDERSTORMS ARE BEGINNING
TO FORM ALONG THE DRYLINE AND ARE EXPECTED TO MOVE TO THE
SOUTHEAST AND INTO OUR CWA. CONDITIONS REMAIN FAVORALE FOR STORMS
TO BECOME SEVERE. WE HAVE ISSUED A SEVERE THUNDERSTOMR WATCH FOR
THE AREA FROM BURNET TO BANDERA TO VAL VERDE COUNTIES AND
NORTHWARD.
&&
.PREV DISCUSSION... /ISSUED 1256 PM CDT SAT APR 18 2015/
AVIATION...
ISOLD SHRA/TSRA ARE POSSIBLE EARLY THIS AFTERNOON. SHRA/TSRA WILL
DEVELOP ALONG THE DRYLINE THIS AFTERNOON NEAR THE EDWARDS PLATEAU
AND MOVE ACROSS THE HILL COUNTRY AND I-35 CORRIDOR AREAS LATE THIS
AFTERNOON INTO THIS EVENING. BEST CHANCES WILL BE AT KAUS/KSAT
WHERE HAVE GONE WITH TEMPO FROM 19/00Z TO 19/04Z. KSSF SHOULD BE
JUST SOUTH OF THE LINE WHILE SHRA/TSRA WILL DISSIPATE WHEN THEY
DRIFT OF THE SERRANIAS DEL BURRO WITH NO IMPACT TO KDRT. AREAS OF
MVFR CIGS WILL LIFT TO VFR SCT-BKN SKIES BY MID AFTERNOON. MVFR
CIGS WILL REDEVELOP OVERNIGHT. DRIER AIR WILL FILTER IN FROM THE
WEST ON SUNDAY WITH A RETURN TO VFR SKIES BY MIDDAY. NELY WINDS
LESS THAN 7 KTS WILL TURN TO SELY THIS AFTERNOON AND THEN SLY
TONIGHT AND THEN WLY ON SUNDAY. WIND GUSTS TO 50 KTS ARE POSSIBLE
IN AND NEAR TSRA.
PREV DISCUSSION... /ISSUED 1201 PM CDT SAT APR 18 2015/
UPDATE...
CONVECTION HAS BEEN A LITTLE SLOWER TO BEGIN THIS MORNING. HAVE
REDUCED POPS FOR THE NEXT COUPLE OF HOURS...ESPECIALLY ACROSS THE
EASTERN HALF OF THE CWA. SPC HAS UPDATED THE DAY ONE OUTLOOK AND
INCREASED OUR RISK TO ENHANCED. EXPECTING STRONG TO SEVERE STORMS
TO FORM LATER THIS AFTERNOON ALONG THE DRYLINE WHICH CURRENTLY
STRETCHES FROM AROUND CHILDRESS TO MIDLAND TO THE BIG BEND. THESE
STORMS WILL MOVE EASTWARD AND INTO OUR NORTHERN AREA LATE THIS
AFTERNOON OR EARLY EVENING. THE MAIN THREAT LOOKS TO BE LARGE HAIL
AND DAMAGING WINDS. THERE IS ALSO A LESSER THREAT FOR TORNADOES. WITH
ALL OF THE RAIN OVER THE PAST COUPLE OF DAYS LOCALLY HEAVY
RAINFALL IN STORMS WILL RUNOFF QUICKLY AND MAY CAUSE FLASH
FLOODING...BUT THIS IS NOT A WIDESPREAD THREAT.
PREV DISCUSSION... /ISSUED 611 AM CDT SAT APR 18 2015/
AVIATION...
CEILINGS ARE IFR/MVFR AROUND THE AREA AIRPORTS THIS MORNING AND
CONDITIONS SHOULD SLOWLY IMPROVE TO VFR BY EARLY AFTERNOON.
CONVECTION HAS DEVELOPED WEST OF KDRT AND WILL SHOW VCTS FOR THE
FIRST FEW HOURS OF THE VALID TAF PERIOD. CONFIDENCE REGARDING
CONVECTION CHANCES THIS AFTERNOON IS NOT VERY HIGH. THE MOST
LIKELY SCENARIO IS FOR THIS ELEVATED CONVECTION TO MOVE EAST THIS
MORNING AND THE ATMOSPHERE TO REENERGIZE BY THE LATE AFTERNOON
HOURS. THERE SHOULD BE A SURFACE CONVERGENCE ZONE DEVELOPING WEST
OF THE I-35 TAF SITES. THE MOST LIKELY TIME THESE WOULD BE TO THE
TERMINALS WOULD BE AROUND 22-03Z. WILL HANDLE THIS WITH A VCTS
FOR NOW. ADDITIONAL MVFR RESTRICTIONS ARE POSSIBLE TONIGHT...BUT
IFR IS NOT ANTICIPATED AS SLIGHTLY DRIER AIR MOVES INTO THE AREA.
HAMPSHIRE
PREV DISCUSSION... /ISSUED 401 AM CDT SAT APR 18 2015/
SHORT TERM (TODAY THROUGH SUNDAY)...
AN UPPER LEVEL STORM SYSTEM IS CENTERED ACROSS COLORADO EARLY THIS
MORNING. THIS SYSTEM IS FORECAST TO MOVE TO THE NORTHEAST AND THEN
EAST THROUGH THE WEEKEND AND BECOMES AN OPEN WAVE LATE SUNDAY
AFTERNOON. SEVERAL SHORT WAVES ASSOCIATED WITH THE UPPER LEVEL
LOW ARE ANTICIPATED TO PUSH ACROSS THE AREA FOR THE NEXT 12 TO 18
HOURS AND ENHANCE STORM DEVELOPMENT LATE THIS MORNING THROUGH THE
EVENING HOURS. AT LOWER LEVELS...A PRE-FRONTAL TROUGH/DRY-LINE
WILL SERVE AS THE MAIN FOCUS AS STORMS FORM IN THE MOIST AND
WARM SECTOR. BY THIS AFTERNOON...DEWPOINT TEMPERATURES ARE
FORECAST TO REACH THE MID TO UPPER 60S WITH AREA SOUNDINGS
SUGGESTING ML CAPES OF 1500 TO 2500J/KG AND LI RANGING FROM -5 TO
-10 FOR LARGE TO EXTREME INSTABILITY. THEREFORE...ANY STORM THAT
DOES DEVELOP HAS THE POTENTIAL TO BECOME STRONG OR SEVERE. PER SPC
DAY 1 CONVECTIVE OUTLOOK...ALL OF SOUTH CENTRAL TEXAS WITH THE
EXCEPTION OF THE NORTHWEST PORTION OF VAL VERDE COUNTY...IS UNDER
A SLIGHT RISK OF SEVERE THUNDERSTORMS.
HIRES SOLUTIONS ARE HAVING DIFFICULTIES ON TIMING AND AREAS OF
STORM DEVELOPMENT INITIALLY. THE HRRR STARTS CONVECTION ACROSS THE
SOUTHERN COUNTIES AS AN MCS DEVELOPS ACROSS THE COASTAL PLAINS AND
MOVE TO THE EAST. THE TEXAS TECH IS MORE AGGRESSIVE ON FORMING
STORMS AHEAD OF THE DRY-LINE AS IT PUSHES TO THE EAST AND OVER THE
EDWARDS PLATEAU/HILL COUNTRY AREA. THE HRRR DOES DEVELOP
CONVECTION AHEAD OF THE DRY-LINE THIS AFTERNOON BUT NOWHERE NEAR
TEXAS TECH MODEL. THEREFORE...THE SHORT-TERM/FIRST PERIOD CONSISTS
ON A BLEND OF THE HRRR/TEXAS TECH SOLUTIONS. BY LATER THIS
EVENING...MID LEVEL WESTERLY WILL TAKE OVER AS THE UPPER LEVEL LOW
PUSHES TO THE EAST...MARKING THE END OF RAIN CHANCES THROUGH
MONDAY. WITH A WESTERLY FLOW IN PLACE FOR SUNDAY...EXPECT A NICE
WARMUP WITH HIGHS IN THE UPPER 80S AND LOWER 90S. CAN NOT RULE OUT
AN ISOLATED STORM ACROSS THE FAR EASTERN COUNTIES SUNDAY
AFTERNOON AS LINGERING INSTABILITY REMAINS. A BACK DOOR COLD FRONT
WILL PUSH ACROSS THE AREA SUNDAY EVENING TO COOL THE OVERNIGHT
TEMPS INTO THE 50S AREAWIDE.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
A CLEAR NIGHT IS IN STORE FOR SUNDAY NIGHT WITH NORTHERLY WINDS
AND COOL TEMPERATURES FOLLOWED BY A PARTLY CLOUDY DAY ON MONDAY.
SOUTHERLY FLOW RETURNS TUESDAY AS WELL AS THE RAIN CHANCES FOR
SOUTH CENTRAL TEXAS. SEVERAL SHORT WAVES ARE EXPECTED TO PASS BY
AND TRIGGER SHOWERS AND STORMS THROUGH FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 61 89 57 76 57 / 40 - - 0 20
AUSTIN BERGSTROM INTL AIRPORT 60 87 55 76 56 / 40 - - 0 20
NEW BRAUNFELS MUNI AIRPORT 60 87 56 76 56 / 30 0 10 - 20
BURNET MUNI AIRPORT 57 87 53 74 54 / 40 0 0 0 20
DEL RIO INTL AIRPORT 59 90 59 79 61 / 20 0 - 10 20
GEORGETOWN MUNI AIRPORT 59 87 54 74 54 / 40 - - 0 20
HONDO MUNI AIRPORT 59 88 57 78 58 / 20 0 - - 30
SAN MARCOS MUNI AIRPORT 61 86 56 75 56 / 40 0 10 - 20
LA GRANGE - FAYETTE REGIONAL 63 86 57 75 58 / 40 10 10 - 20
SAN ANTONIO INTL AIRPORT 61 88 58 77 59 / 30 0 - - 30
STINSON MUNI AIRPORT 61 88 59 77 59 / 20 0 10 - 30
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...05
PUBLIC SERVICE/DATA COLLECTION...01
AREA FORECAST DISCUSSION
NWS AMARILLO TX
221 PM CDT SAT APR 18 2015
.DISCUSSION...
EARLY THIS AFTERNOON A DEEP CLOSED LOW WAS SITUATED OVER EASTERN
COLORADO AND SLOWLY MOVING EAST. A BAND OF CLOUDS ASSOCIATED WITH A
RELATIVELY POTENT VORT LOBE ROTATING AROUND THE MID-UPPER LOW WAS
EVIDENT IN IR/VIS SATELLITE. SURFACE OBSERVATIONS SHOW LIGHT RAIN
BENEATH THIS BAND OF CLOUDS AT CLAYTON NEW MEXICO AND PRESUMABLY
FURTHER SOUTH-SOUTHWEST EAST OF TUCUMCARI INTO THE FAR WESTERN TEXAS
PANHANDLE WHERE LIGHT ECHOS WERE PRESENT ON REGIONAL RADAR MOSAIC.
FURTHER EAST ACROSS THE TEXAS AND OKLAHOMA PANHANDLE LOW CLOUDS HAVE
DIMINISHED AND/OR SHIFTED INTO OKLAHOMA AS SURFACE WINDS CONTINUE TO
VEER SLIGHTLY. SHALLOW LOW LEVEL MOISTURE SEEN ON 12Z KAMA SOUNDING
REMAINS ACROSS THE EASTERN PANHANDLES EAST OF A DIFFUSE DRYLINE.
THERE REMAINS SOME UNCERTAINTY ON THE POSITION OF THE DRYLINE THAT
IS EXPECTED TO SHARPEN THIS AFTERNOON AS DIABATIC HEATING/MIXING
COMMENCES. USING SHORT RANGE MODEL FORECAST SOUNDINGS AS GUIDANCE ON
THE DEPTH OF MOISTURE OFF THE CAPROCK AND ESPECIALLY FURTHER EAST
NEAR THE OKLAHOMA BORDER LEADS TO FAIRLY HIGH CONFIDENCE ON THE
PREVIOUS FORECAST WHICH RELEGATES ANY SUBSTANTIAL DEEP CONVECTION TO
NEAR OR JUST EAST OF THE OKLAHOMA STATE LINE LATER THIS AFTERNOON.
LOW LEVEL MOISTURE IS DEEPER FROM THERE EASTWARD INTO OKLAHOMA AND
THUS DRYLINE CIRCULATION THAT DEVELOPS STANDS A BETTER CHANCE AT
INITIATING CONVECTION THERE THAN WAS THE CASE FURTHER WEST
YESTERDAY. SO THROUGH THE LATE AFTERNOON AND EVENING THERE IS ONLY A
LOW PROBABILITY OF ISOLATED-SCATTERED CONVECTION ACROSS THE EXTREME
EASTERN PORTION OF THE PANHANDLES WITH BETTER CHANCES OUT OF THE
FORECAST AREA ACROSS WESTERN OKLAHOMA. IF THE ABOVE ASSESSMENT IS
MISPLACED SLIGHTLY EAST THAN ANY STORM THAT DOES DEVELOP ON OUR SIDE
OF THE STATE LINE WOULD HAVE THE POTENTIAL TO BECOME SEVERE DUE TO
MODERATE INSTABILITY AND SUFFICIENT DEEP LAYER SHEAR OF AROUND 30
KNOTS FOR STORM ORGANIZATION/PERSISTENCE. LARGE HAIL WOULD BE THE
PRIMARY THREAT INTO THE EVENING GIVEN STEEP MID LEVEL LAPSE RATES
OWING TO THE APPROACHING MID-UPPER LOW. WILL CONTINUE TO MONITOR
TRENDS IN SURFACE OBSERVATIONS AND DRYLINE EVOLUTION THROUGHOUT THE
AFTERNOON.
FURTHER WEST OF THE DRYLINE...DEEP MIXING WILL OCCUR GENERALLY EAST
OF THE AFOREMENTIONED BAND OF LOW-MID CLOUDS NOW ENTERING THE TEXAS
PANHANDLE. CU FIELD IS INCREASING IMMEDIATELY AHEAD OF THIS. BASES
SHOULD BECOME RELATIVELY HIGH AS MIXED LAYER DEEPENS THROUGH THE
AFTERNOON. WITH FORCING FROM PREVIOUSLY MENTIONED VORT LOBE
CONVECTION MAY BECOME DEEP ENOUGH FOR SHOWERS AND THUNDERSTORMS FOR
MUCH OF THE AREA LATER THIS AFTERNOON. IF CONVECTION BECOMES DEEP
ENOUGH FOR CHARGE SEPARATION AND LIGHTNING...LIMITED INSTABILITY
SHOULD PRECLUDE THE THREAT OF SEVERE THUNDERSTORMS. PROGNOSTICATIONS
FROM THE HI-RES CONVECTION ALLOWING GUIDANCE INCLUDING THE HRRR AND
TTU WRF SEEM TO LINE UP WELL WITH THE ABOVE THINKING.
AS THE MID-UPPER LOW CONTINUES TO SHIFT EAST A COLD FRONT WILL MOVE
THROUGH THE AREA TONIGHT. MODEL GUIDANCE IS IN AGREEMENT IN AN
EVOLUTION OF THE LOW INTO A MORE OPEN AND PROGRESSIVE WAVE THAT WILL
BE EAST OF THE AREA BY TOMORROW AFTERNOON. AN AREA OF MOISTURE ON
THE BACK SIDE OF THIS EVOLVING SHORTWAVE TROUGH FAVORABLY TIMED WITH
PEAK HEATING SHOULD BE ENOUGH FOR EXTENSIVE CUMULUS DEVELOPMENT
DURING THE AFTERNOON POSSIBLY ENOUGH FOR BROKEN SKY CONDITIONS
ESPECIALLY ACROSS THE EASTERN PORTION OF THE AREA. DEPTH OF
CONVECTION IN ROUGHLY THE NORTHEAST THIRD WILL NEED TO BE MONITORED
AS IT MAY BECOME SUFFICIENT FOR A FEW SHOWERS GIVEN RESIDUAL COOL MID
LEVEL TEMPERATURES AND RELATIVELY HIGH TQ INDEX VALUES. ADJUSTED LOW
POPS ON SUNDAY AFTERNOON TO EXTEND A BIT FURTHER SOUTH AND WEST TO
ACCOUNT FOR THIS.
EARLY NEXT WEEK A SPLIT UPPER FLOW PATTERN WILL EXIST WITH STRONG
PERIODICALLY PERTURBED WESTERLY SOUTHERN BRANCH JUST SOUTH OF US AND
NORTHWESTERLY NORTHERN BRANCH ACROSS THE CENTRAL PLAINS. MEAN
RIDGING WILL BE PRESENT OVER THE WESTERN STATES. GRADUALLY
INCREASING 500 MB HEIGHTS AND A SLIGHTLY MORE AMPLIFIED PATTERN WILL
EVOLVE THROUGH THE WEEK ESPECIALLY AS ANOTHER CLOSED LOW DEVELOPS
AND DEEPENS OVER THE SOUTHWESTERN CONUS BY THURSDAY. AS THIS MOVES
EAST THIS WILL PROBABLY RESULT IN ANOTHER CONVECTIVELY ACTIVE
PATTERN FOR THE LATTER HALF OF THE WEEK. AS IS TYPICALLY THE CASE AT
THAT TIME RANGE MODEL GUIDANCE DIFFERS IN TIMING AND AMPLITUDE BUT
THE SIGNAL IS THERE FOR A SCENARIO FAVORING A NORTH/WEST SURGE OF
LOW LEVEL MOISTURE AND FORCING FOR ASCENT RESULTING IN ABOVE CLIMO
PRECIPITATION PROBABILITIES AND THE POSSIBILITY OF SEVERE
THUNDERSTORMS BY MID AND ESPECIALLY LATE WEEK. EVEN BEFORE THEN
THERE WILL BE A FEW OPPORTUNITIES FOR PRECIPITATION EARLIER IN THE
WEEK AS DIFFICULT TO RESOLVE SMALL SHORTWAVE TROUGHS WITHIN MEAN
WEST-NORTHWESTERLY FLOW CROSS THE AREA. CONVECTION MAY EMANATE FROM
THE HIGHER TERRAIN OF COLORADO AND NEW MEXICO AND MOVE INTO THE
PANHANDLES LATE MONDAY AND AGAIN LATE TUESDAY...ALTHOUGH THIS
FORECAST WILL BE LESS DETERMINISTIC WITH TIMING OF HIGHER
PROBABILITIES OF PRECIPITATION AND MORE BROAD BRUSH GIVEN INHERENT
UNCERTAINTIES OF THIS TYPE PATTERN.
BRB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
05/17
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1256 PM CDT SAT APR 18 2015
.AVIATION...
ISOLD SHRA/TSRA ARE POSSIBLE EARLY THIS AFTERNOON. SHRA/TSRA WILL
DEVELOP ALONG THE DRYLINE THIS AFTERNOON NEAR THE EDWARDS PLATEAU
AND MOVE ACROSS THE HILL COUNTRY AND I-35 CORRIDOR AREAS LATE THIS
AFTERNOON INTO THIS EVENING. BEST CHANCES WILL BE AT KAUS/KSAT
WHERE HAVE GONE WITH TEMPO FROM 19/00Z TO 19/04Z. KSSF SHOULD BE
JUST SOUTH OF THE LINE WHILE SHRA/TSRA WILL DISSIPATE WHEN THEY
DRIFT OF THE SERRANIAS DEL BURRO WITH NO IMPACT TO KDRT. AREAS OF
MVFR CIGS WILL LIFT TO VFR SCT-BKN SKIES BY MID AFTERNOON. MVFR
CIGS WILL REDEVELOP OVERNIGHT. DRIER AIR WILL FILTER IN FROM THE
WEST ON SUNDAY WITH A RETURN TO VFR SKIES BY MIDDAY. NELY WINDS
LESS THAN 7 KTS WILL TURN TO SELY THIS AFTERNOON AND THEN SLY
TONIGHT AND THEN WLY ON SUNDAY. WIND GUSTS TO 50 KTS ARE POSSIBLE
IN AND NEAR TSRA.
&&
.PREV DISCUSSION... /ISSUED 1201 PM CDT SAT APR 18 2015/
UPDATE...
CONVECTION HAS BEEN A LITTLE SLOWER TO BEGIN THIS MORNING. HAVE
REDUCED POPS FOR THE NEXT COUPLE OF HOURS...ESPECIALLY ACROSS THE
EASTERN HALF OF THE CWA. SPC HAS UPDATED THE DAY ONE OUTLOOK AND
INCREASED OUR RISK TO ENHANCED. EXPECTING STRONG TO SEVERE STORMS
TO FORM LATER THIS AFTERNOON ALONG THE DRYLINE WHICH CURRENTLY
STRETCHES FROM AROUND CHILDRESS TO MIDLAND TO THE BIG BEND. THESE
STORMS WILL MOVE EASTWARD AND INTO OUR NORTHERN AREA LATE THIS
AFTERNOON OR EARLY EVENING. THE MAIN THREAT LOOKS TO BE LARGE HAIL
AND DAMAGING WINDS. THERE IS ALSO A LESSER THREAT FOR TORNADOES. WITH
ALL OF THE RAIN OVER THE PAST COUPLE OF DAYS LOCALLY HEAVY
RAINFALL IN STORMS WILL RUNOFF QUICKLY AND MAY CAUSE FLASH
FLOODING...BUT THIS IS NOT A WIDESPREAD THREAT.
PREV DISCUSSION... /ISSUED 611 AM CDT SAT APR 18 2015/
AVIATION...
CEILINGS ARE IFR/MVFR AROUND THE AREA AIRPORTS THIS MORNING AND
CONDITIONS SHOULD SLOWLY IMPROVE TO VFR BY EARLY AFTERNOON.
CONVECTION HAS DEVELOPED WEST OF KDRT AND WILL SHOW VCTS FOR THE
FIRST FEW HOURS OF THE VALID TAF PERIOD. CONFIDENCE REGARDING
CONVECTION CHANCES THIS AFTERNOON IS NOT VERY HIGH. THE MOST
LIKELY SCENARIO IS FOR THIS ELEVATED CONVECTION TO MOVE EAST THIS
MORNING AND THE ATMOSPHERE TO REENERGIZE BY THE LATE AFTERNOON
HOURS. THERE SHOULD BE A SURFACE CONVERGENCE ZONE DEVELOPING WEST
OF THE I-35 TAF SITES. THE MOST LIKELY TIME THESE WOULD BE TO THE
TERMINALS WOULD BE AROUND 22-03Z. WILL HANDLE THIS WITH A VCTS
FOR NOW. ADDITIONAL MVFR RESTRICTIONS ARE POSSIBLE TONIGHT...BUT
IFR IS NOT ANTICIPATED AS SLIGHTLY DRIER AIR MOVES INTO THE AREA.
HAMPSHIRE
PREV DISCUSSION... /ISSUED 401 AM CDT SAT APR 18 2015/
SHORT TERM (TODAY THROUGH SUNDAY)...
AN UPPER LEVEL STORM SYSTEM IS CENTERED ACROSS COLORADO EARLY THIS
MORNING. THIS SYSTEM IS FORECAST TO MOVE TO THE NORTHEAST AND THEN
EAST THROUGH THE WEEKEND AND BECOMES AN OPEN WAVE LATE SUNDAY
AFTERNOON. SEVERAL SHORT WAVES ASSOCIATED WITH THE UPPER LEVEL
LOW ARE ANTICIPATED TO PUSH ACROSS THE AREA FOR THE NEXT 12 TO 18
HOURS AND ENHANCE STORM DEVELOPMENT LATE THIS MORNING THROUGH THE
EVENING HOURS. AT LOWER LEVELS...A PRE-FRONTAL TROUGH/DRY-LINE
WILL SERVE AS THE MAIN FOCUS AS STORMS FORM IN THE MOIST AND
WARM SECTOR. BY THIS AFTERNOON...DEWPOINT TEMPERATURES ARE
FORECAST TO REACH THE MID TO UPPER 60S WITH AREA SOUNDINGS
SUGGESTING ML CAPES OF 1500 TO 2500J/KG AND LI RANGING FROM -5 TO
-10 FOR LARGE TO EXTREME INSTABILITY. THEREFORE...ANY STORM THAT
DOES DEVELOP HAS THE POTENTIAL TO BECOME STRONG OR SEVERE. PER SPC
DAY 1 CONVECTIVE OUTLOOK...ALL OF SOUTH CENTRAL TEXAS WITH THE
EXCEPTION OF THE NORTHWEST PORTION OF VAL VERDE COUNTY...IS UNDER
A SLIGHT RISK OF SEVERE THUNDERSTORMS.
HIRES SOLUTIONS ARE HAVING DIFFICULTIES ON TIMING AND AREAS OF
STORM DEVELOPMENT INITIALLY. THE HRRR STARTS CONVECTION ACROSS THE
SOUTHERN COUNTIES AS AN MCS DEVELOPS ACROSS THE COASTAL PLAINS AND
MOVE TO THE EAST. THE TEXAS TECH IS MORE AGGRESSIVE ON FORMING
STORMS AHEAD OF THE DRY-LINE AS IT PUSHES TO THE EAST AND OVER THE
EDWARDS PLATEAU/HILL COUNTRY AREA. THE HRRR DOES DEVELOP
CONVECTION AHEAD OF THE DRY-LINE THIS AFTERNOON BUT NOWHERE NEAR
TEXAS TECH MODEL. THEREFORE...THE SHORT-TERM/FIRST PERIOD CONSISTS
ON A BLEND OF THE HRRR/TEXAS TECH SOLUTIONS. BY LATER THIS
EVENING...MID LEVEL WESTERLY WILL TAKE OVER AS THE UPPER LEVEL LOW
PUSHES TO THE EAST...MARKING THE END OF RAIN CHANCES THROUGH
MONDAY. WITH A WESTERLY FLOW IN PLACE FOR SUNDAY...EXPECT A NICE
WARMUP WITH HIGHS IN THE UPPER 80S AND LOWER 90S. CAN NOT RULE OUT
AN ISOLATED STORM ACROSS THE FAR EASTERN COUNTIES SUNDAY
AFTERNOON AS LINGERING INSTABILITY REMAINS. A BACK DOOR COLD FRONT
WILL PUSH ACROSS THE AREA SUNDAY EVENING TO COOL THE OVERNIGHT
TEMPS INTO THE 50S AREAWIDE.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
A CLEAR NIGHT IS IN STORE FOR SUNDAY NIGHT WITH NORTHERLY WINDS
AND COOL TEMPERATURES FOLLOWED BY A PARTLY CLOUDY DAY ON MONDAY.
SOUTHERLY FLOW RETURNS TUESDAY AS WELL AS THE RAIN CHANCES FOR
SOUTH CENTRAL TEXAS. SEVERAL SHORT WAVES ARE EXPECTED TO PASS BY
AND TRIGGER SHOWERS AND STORMS THROUGH FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 81 61 89 57 76 / 40 40 - - -
AUSTIN BERGSTROM INTL AIRPORT 81 60 87 55 76 / 50 40 - - -
NEW BRAUNFELS MUNI AIRPORT 81 60 87 56 76 / 50 30 0 - -
BURNET MUNI AIRPORT 79 57 87 53 74 / 40 40 - - -
DEL RIO INTL AIRPORT 86 59 90 59 79 / 30 10 0 - 10
GEORGETOWN MUNI AIRPORT 79 59 87 54 74 / 40 40 10 - -
HONDO MUNI AIRPORT 82 59 88 57 78 / 40 20 0 - -
SAN MARCOS MUNI AIRPORT 81 61 86 56 75 / 50 40 0 - -
LA GRANGE - FAYETTE REGIONAL 80 63 86 57 75 / 50 40 20 10 10
SAN ANTONIO INTL AIRPORT 81 61 88 58 77 / 40 30 0 - -
STINSON MUNI AIRPORT 82 61 88 59 77 / 40 20 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...05
PUBLIC SERVICE/DATA COLLECTION...01
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1249 PM CDT SAT APR 18 2015
.AVIATION...
THE UPPER LOW NOW SPINNING OVER COLORADO WILL MOVE EAST ACROSS THE
PLAINS OVER THE NEXT 24 HOURS. A SHORTWAVE TROUGH WORKING ITS WAY
AROUND THE SOUTH SIDE OF THE UPPER LOW WILL MOVE ACROSS CENTRAL
TEXAS THIS AFTERNOON...AIDING IN THE DEVELOPMENT OF SCATTERED
SHOWERS AND THUNDERSTORMS WEST OF THE TAF LOCATIONS LATE THIS
AFTERNOON. CONVECTION WILL SPREAD EAST ACROSS NORTH TEXAS THIS
EVENING. TIMING WILL BE A CHALLENGE...BUT THE LATEST HI-RES
GUIDANCE ONCE AGAIN PINPOINTS THE 00-04Z TIME FRAME AS THE MOST
LIKELY AT ALL TAF LOCATIONS THIS EVENING. CONVECTION SHOULD MOVE
EAST OF THE AREA AND WEAKEN AROUND MIDNIGHT LOCAL.
A COLD FRONT WILL PUSH SOUTHEAST ACROSS NORTH TEXAS TOMORROW.
SOUTH TO SOUTHWEST WINDS WILL INCREASE TO 10-15 KT AROUND SUNRISE
AHEAD OF THE FRONT. WINDS WILL VEER TO THE WEST SHORTLY AFTER 18Z
WHILE INCREASING TO 15-20 KT. NORTHWEST WINDS ARE EXPECTED AT ALL
LOCATIONS BY 00Z SUNDAY EVENING. AT THIS TIME...IT APPEARS THAT
ANY CONVECTION ASSOCIATED WITH THE FRONT WILL REMAIN EAST OF ALL
TAF SITES.
30
&&
.UPDATE...
MORNING UPPER AIR DATA AND SHORT-TERM MODEL GUIDANCE HAS
IDENTIFIED A SHORTWAVE TROUGH THAT IS PIVOTING AROUND THE UPPER
LOW OVER COLORADO. THIS SHORTWAVE WILL TRACK THROUGH TEXAS THIS
AFTERNOON AND EVENING. A DRY LINE IS FORECAST TO SET UP JUST WEST
OF THE CWA BORDER THIS AFTERNOON AND WILL BECOME THE FOCUS FOR
SCATTERED CONVECTION WHEN FORCING FROM THE SHORTWAVE TROUGH
ARRIVES. CONVECTIVE INITIATION SHOULD START AFTER 3 PM JUST WEST
OF THE CWA...WITH THESE STORMS MOVING/DEVELOPING GRADUALLY
NORTHEASTWARD INTO AND THROUGH THE CWA DURING THE LATE AFTERNOON
AND EVENING HOURS. GIVEN THE EXPECTED TIMING...HAVE LOWERED THE
POPS ALONG AND EAST OF I-35 FOR THE TODAY PERIOD AS ANY
RAIN/STORMS SHOULD HOLD OFF UNTIL THIS EVENING FOR THESE AREAS.
THERE IS A LACK OF LOW LEVEL WIND FLOW EVIDENT IN THE MORNING
DATA AND THE AIRMASS HAS BEEN FAIRLY WORKED OVER BY THE CONVECTION
FROM YESTERDAY AND LAST NIGHT. HOWEVER THE APPROACH OF THE
SHORTWAVE TROUGH WILL HELP TURN WINDS TO THE SOUTH BY THE
AFTERNOON...THEREBY INCREASING MOISTURE/THETA-E ADVECTION AND BULK
SHEAR VALUES ACROSS NORTH TEXAS. TEMPERATURES WILL ALSO WARM INTO
THE UPPER 70S AND LOWER 80S OVER NORTH TEXAS TODAY...WHICH WILL
YIELD GENERALLY 1000-2000 J/KG OF SURFACE BASED CAPE. THUS THE
AIRMASS SHOULD BE RECHARGED JUST ENOUGH TO SUPPORT SCATTERED
CONVECTION WITH A POTENTIAL FOR SEVERE WIND AND HAIL...ESPECIALLY
WEST OF I-35 IN THE LATE AFTERNOON HOURS. THE SEVERE THREAT WILL
DIMINISH AS THE STORMS HEAD EAST OF I-35 DUE TO THE LOSS OF
HEATING AND INCREASING CINH.
TR.92
&&
.PREV DISCUSSION... /ISSUED 415 AM CDT SAT APR 18 2015/
THE UPPER LOW THAT HAS BEEN PARKED OVER THE FOUR CORNERS IS
BEGINNING TO DISLODGE...AND BY THIS TIME SUNDAY MORNING IT WILL BE
OVER THE HIGH PLAINS NEAR THE COLORADO/KANSAS BORDER. THIS WILL
STEADILY VEER THE 700MB FLOW ACROSS WEST TEXAS TODAY...HELPING TO
NUDGE THE DRYLINE FARTHER EAST THAN IN RECENT DAYS. ALTHOUGH
WITHIN THE FIRST 24 HOURS OF THE LATEST GUIDANCE...OPERATIONAL
SOLUTIONS VARY WIDELY ON THE LATE AFTERNOON POSITION. ALTHOUGH THE
NAM IS AMONG THE FARTHEST WEST...WHICH IS UNUSUAL IN THIS
SCENARIO...THE CONSENSUS AMONG THE MESOSCALE GUIDANCE IS FOR THE
BOUNDARY TO REACH A VERNON-SAN ANGELO LINE NEAR PEAK HEATING. OUR
FORECAST WILL FAVOR THIS POSITION. BASED ON THE MID-LEVEL FLOW...
THERE SHOULD BE A BULGE NEAR THE RED RIVER. THE RAP AND TTU WRF
SHOW THIS CLEARLY...ADDING TO THE CONFIDENCE IN THEIR EVOLUTION OF
THE BOUNDARY TODAY.
THE ATMOSPHERE ACROSS NORTH TEXAS HAS BEEN WELL WORKED OVER. THIS
STABILITY...COUPLED WITH SUBSIDENCE IN THE WAKE OF A DEPARTING
DISTURBANCE...SHOULD PRECLUDE MUCH ADDITIONAL PRECIPITATION THIS
MORNING. WEAK LOW-LEVEL FLOW WILL RESULT IN NEGLIGIBLE MOIST
ADVECTION TODAY...AND DESTABILIZATION THIS AFTERNOON WILL BE
PRIMARILY GOVERNED BY SURFACE HEATING. ALTHOUGH THE I-35 CORRIDOR
WILL BE SLOW TO CLEAR TODAY...WESTERN NORTH TEXAS WILL SEE
SUFFICIENT SUNSHINE. EXPECT THUNDERSTORMS TO DEVELOP ALONG THE
DRYLINE MID TO LATE AFTERNOON. THOUGH RELATIVELY WEAK...THE
STEERING FLOW ALOFT SHOULD GUIDE THE ACTIVITY EAST THROUGH NORTH
TEXAS THIS EVENING. EVEN THOUGH THE SURFACE LAYER WILL BE
STEADILY STABILIZING AT THAT TIME...THE COLD POOL ASSOCIATED WITH
AN ORGANIZED MCS SHOULD PROLONG THE LIFESPAN OF ITS UPDRAFTS. THIS
WILL MAINTAIN A HAIL THREAT WELL INTO THE EVENING. THIS IS NOT THE
TYPICAL SETUP FOR A SQUALL LINE...BUT A WELL ORGANIZED COMPLEX
COULD POSE A WIND THREAT AS WELL. THE SPEED SHOULD BE SUFFICIENT
TO AVOID SIGNIFICANT FLOODING CONCERNS IN MOST AREAS...BUT WHERE
HEAVY RAIN HAS FALLEN RECENTLY...ADDITIONAL RAINFALL COULD
REAGGRAVATE FLOODING ISSUES.
AS THE UPPER LOW EJECTS THROUGH THE CENTRAL PLAINS...IT WILL SURGE
A COLD FRONT THROUGH THE REGION. WITH WIDESPREAD ACTIVITY THIS
EVENING...LARGE-SCALE SUBSIDENCE INVADING...AND VEERING LOW-LEVEL
FLOW EARLY SUNDAY...THE ATMOSPHERE SHOULD BE UNABLE TO PRODUCE ANY
FRONTAL PRECIPITATION. THE EXCEPTION WOULD BE EAST TEXAS...WHERE
THE MOISTURE PROFILE WILL BE MORE FAVORABLE...AND THE FRONT WILL
ARRIVE DURING THE WARM AFTERNOON HOURS. ABUNDANT APRIL SUNSHINE
AND A PRONOUNCED DOWNSLOPE WIND SHOULD OFFSET ANY COLD ADVECTION
BEHIND THE FRONT...AND TEMPERATURES SHOULD REACH THE 80S IN MANY
AREAS SUNDAY AFTERNOON. THE COOL AIR WILL ARRIVE SUNDAY NIGHT...
AND RURAL AREAS IN THE NORTHERN HALF OF THE CWA WILL LIKELY DIP
INTO THE 40S MONDAY AND TUESDAY MORNING.
ZONAL FLOW WILL PREVAIL MUCH OF THE UPCOMING WEEK. THE NEXT WAVE
EMBEDDED IN THIS WESTERLY FLOW WILL ARRIVE AROUND TUESDAY...BUT
AT THAT TIME...BOUNDARY LAYER MOISTURE MAY NOT HAVE BEEN ABLE TO
SUFFICIENTLY RECOVER. ADDITIONAL RIPPLES WILL FOLLOW...MAINTAINING
RAIN CHANCES. HOWEVER...POPS ARE NOTHING MORE THAN CLIMATOLOGY.
EXTENDED GUIDANCE IS IN REMARKABLY GOOD AGREEMENT WITH
UNSEASONABLE STRONG SHORTWAVE RIDGING AS THE NEXT UPPER LOW ENTERS
THE DESERT SOUTHWEST. GFS MOS TEMPS FOR THURSDAY AND FRIDAY ARE
NEAR 90 DEGREES. WITH PERFECT PROG 850MB TEMPS AROUND 20C...THIS
IS NOT OUT OF THE QUESTION. A BIT CONCERNED THAT CLOUD COVER MAY
PUT A DAMPER ON THE SPRING FEVER...AND FOR NOW...WILL KEEP
TEMPERATURES CLOSER TO CLIMATOLOGY.
25
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 79 60 80 53 73 / 20 50 10 5 5
WACO, TX 80 60 83 53 75 / 20 50 10 5 5
PARIS, TX 75 58 77 50 70 / 20 40 20 5 0
DENTON, TX 77 57 79 49 72 / 30 50 10 5 5
MCKINNEY, TX 78 58 79 51 73 / 20 50 10 5 0
DALLAS, TX 80 62 81 54 74 / 20 50 10 5 5
TERRELL, TX 78 60 80 52 74 / 20 50 10 5 5
CORSICANA, TX 79 61 82 52 75 / 20 50 20 5 5
TEMPLE, TX 79 60 84 53 74 / 20 50 10 5 5
MINERAL WELLS, TX 81 55 79 48 74 / 40 50 10 5 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
30/92
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1248 PM CDT SAT APR 18 2015
.AVIATION...
SAT IMAGERY SUGGESTS INLAND PORTIONS OF SE TX SHOULD START SEEING
SOME INTERMITTENT BREAKS OF SUN. ELSEWHERE...EXPECT TO SEE
IMPROVING CIG HEIGHTS IN THE NEXT COUPLE HOURS. THERE IS A SFC
BOUNDARY NEAR THE COAST...SO ADDITIONAL HEATING ALONG WITH
APPROACHING S/W FROM MID TX COAST SHOULD ALLOW FOR AT LEAST SOME
SCT TSRA TO DEVELOP THIS AFTN - ESP SOUTH OF A COLUMBUS-LIBERTY
LINE. (THIS IS ROUGHLY THE SAME LOCATIONS THAT SAW SOME SIG WX
YDAY SO WILL NEED TO KEEP A CLOSE EYE ON THINGS.) AREAS FURTHER N
WILL NEED TO KEEP AN EYE ON NW TX. MODELS ARE POINTING TOWARD A
DEVELOPING LINE OF SHRA/TSRA OUT THERE THIS AFTN...POSSIBLY MAKING
IT ESE TOWARD SE TX LATE EVNG & OVERNIGHT. WILL SEE HOW THIS ALL
PLAYS OUT, BUT WENT AHEAD AND THREW THE POTENTIAL OF THIS
OCCURRING IN THE 9-2AM TIMEFRAME IN THE CLL, UTS, CXO TAFS.
CONSIDERABLE UNCERTAINTY IN THIS ATTM BUT FEEL IT`S ENOUGH TO
BEGIN MENTIONING. 47
&&
.PREV DISCUSSION... /ISSUED 1145 AM CDT SAT APR 18 2015/
A STATIONARY FRONT WAS LOCATED JUST OFFSHORE ALONG THE COAST. THE
AIRMASS ALONG ABOUT A TWO-TIER COUNTY WIDTH ALONG THE COAST WAS
FAIRLY MOIST. NAMBUFR MODEL SOUNDINGS SHOW INCREASING INSTABILITY
DURING THE AFTERNOON WITH HEATING AND AS THE FRONTAL BOUNDARY
DRIFTS BACK INLAND. WATER VAPOR OVER THE PAST FEW HOURS SHOWED AN
APPROACHING SHORTWAVE TROUGH MOVING TOWARD THE AREA FROM THE
SOUTH. THE 06Z TEXAS TECH WRF AND 15Z HRRR BOTH FORECASTED BEST
CHANCES STARTING NEAR THE COAST BASICALLY ALONG AND EAST OF THE
HIGHWAY 59 CORRIDOR FROM MID AFTERNOON THROUGH MID EVENING.
ANOTHER UPPER LEVEL SHORTWAVE TROUGH WILL MOVE ACROSS SE TEXAS
LATE THIS EVENING FROM THE WEST. THIS MAY HELP GENERATE ADDITIONAL
SCATTERED STORMS DURING THE LATE EVENING AND INTO THE OVERNIGHT
PERIOD.
TWEAKED RAIN CHANCES MAINLY FOR TONIGHT AND ALSO TEMPERATURES FOR
TODAY. 40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 79 62 85 56 75 / 30 40 10 0 0
HOUSTON (IAH) 80 64 84 60 78 / 50 30 20 10 0
GALVESTON (GLS) 77 69 81 67 75 / 40 30 20 20 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1201 PM CDT SAT APR 18 2015
.UPDATE...
CONVECTION HAS BEEN A LITTLE SLOWER TO BEGIN THIS MORNING. HAVE
REDUCED POPS FOR THE NEXT COUPLE OF HOURS...ESPECIALLY ACROSS THE
EASTERN HALF OF THE CWA. SPC HAS UPDATED THE DAY ONE OUTLOOK AND
INCREASED OUR RISK TO ENHANCED. EXPECTING STRONG TO SEVERE STORMS
TO FORM LATER THIS AFTERNOON ALONG THE DRYLINE WHICH CURRENTLY
STRETCHES FROM AROUND CHILDRESS TO MIDLAND TO THE BIG BEND. THESE
STORMS WILL MOVE EASTWARD AND INTO OUR NORTHERN AREA LATE THIS
AFTERNOON OR EARLY EVENING. THE MAIN THREAT LOOKS TO BE LARGE HAIL
AND DAMAGING WINDS. THERE IS ALSO A LESSER THREAT FOR TORNADOES. WITH
ALL OF THE RAIN OVER THE PAST COUPLE OF DAYS LOCALLY HEAVY
RAINFALL IN STORMS WILL RUNOFF QUICKLY AND MAY CAUSE FLASH
FLOODING...BUT THIS IS NOT A WIDESPREAD THREAT.
&&
.PREV DISCUSSION... /ISSUED 611 AM CDT SAT APR 18 2015/
AVIATION...
CEILINGS ARE IFR/MVFR AROUND THE AREA AIRPORTS THIS MORNING AND
CONDITIONS SHOULD SLOWLY IMPROVE TO VFR BY EARLY AFTERNOON.
CONVECTION HAS DEVELOPED WEST OF KDRT AND WILL SHOW VCTS FOR THE
FIRST FEW HOURS OF THE VALID TAF PERIOD. CONFIDENCE REGARDING
CONVECTION CHANCES THIS AFTERNOON IS NOT VERY HIGH. THE MOST
LIKELY SCENARIO IS FOR THIS ELEVATED CONVECTION TO MOVE EAST THIS
MORNING AND THE ATMOSPHERE TO REENERGIZE BY THE LATE AFTERNOON
HOURS. THERE SHOULD BE A SURFACE CONVERGENCE ZONE DEVELOPING WEST
OF THE I-35 TAF SITES. THE MOST LIKELY TIME THESE WOULD BE TO THE
TERMINALS WOULD BE AROUND 22-03Z. WILL HANDLE THIS WITH A VCTS
FOR NOW. ADDITIONAL MVFR RESTRICTIONS ARE POSSIBLE TONIGHT...BUT
IFR IS NOT ANTICIPATED AS SLIGHTLY DRIER AIR MOVES INTO THE AREA.
HAMPSHIRE
PREV DISCUSSION... /ISSUED 401 AM CDT SAT APR 18 2015/
SHORT TERM (TODAY THROUGH SUNDAY)...
AN UPPER LEVEL STORM SYSTEM IS CENTERED ACROSS COLORADO EARLY THIS
MORNING. THIS SYSTEM IS FORECAST TO MOVE TO THE NORTHEAST AND THEN
EAST THROUGH THE WEEKEND AND BECOMES AN OPEN WAVE LATE SUNDAY
AFTERNOON. SEVERAL SHORT WAVES ASSOCIATED WITH THE UPPER LEVEL
LOW ARE ANTICIPATED TO PUSH ACROSS THE AREA FOR THE NEXT 12 TO 18
HOURS AND ENHANCE STORM DEVELOPMENT LATE THIS MORNING THROUGH THE
EVENING HOURS. AT LOWER LEVELS...A PRE-FRONTAL TROUGH/DRY-LINE
WILL SERVE AS THE MAIN FOCUS AS STORMS FORM IN THE MOIST AND
WARM SECTOR. BY THIS AFTERNOON...DEWPOINT TEMPERATURES ARE
FORECAST TO REACH THE MID TO UPPER 60S WITH AREA SOUNDINGS
SUGGESTING ML CAPES OF 1500 TO 2500J/KG AND LI RANGING FROM -5 TO
-10 FOR LARGE TO EXTREME INSTABILITY. THEREFORE...ANY STORM THAT
DOES DEVELOP HAS THE POTENTIAL TO BECOME STRONG OR SEVERE. PER SPC
DAY 1 CONVECTIVE OUTLOOK...ALL OF SOUTH CENTRAL TEXAS WITH THE
EXCEPTION OF THE NORTHWEST PORTION OF VAL VERDE COUNTY...IS UNDER
A SLIGHT RISK OF SEVERE THUNDERSTORMS.
HIRES SOLUTIONS ARE HAVING DIFFICULTIES ON TIMING AND AREAS OF
STORM DEVELOPMENT INITIALLY. THE HRRR STARTS CONVECTION ACROSS THE
SOUTHERN COUNTIES AS AN MCS DEVELOPS ACROSS THE COASTAL PLAINS AND
MOVE TO THE EAST. THE TEXAS TECH IS MORE AGGRESSIVE ON FORMING
STORMS AHEAD OF THE DRY-LINE AS IT PUSHES TO THE EAST AND OVER THE
EDWARDS PLATEAU/HILL COUNTRY AREA. THE HRRR DOES DEVELOP
CONVECTION AHEAD OF THE DRY-LINE THIS AFTERNOON BUT NOWHERE NEAR
TEXAS TECH MODEL. THEREFORE...THE SHORT-TERM/FIRST PERIOD CONSISTS
ON A BLEND OF THE HRRR/TEXAS TECH SOLUTIONS. BY LATER THIS
EVENING...MID LEVEL WESTERLY WILL TAKE OVER AS THE UPPER LEVEL LOW
PUSHES TO THE EAST...MARKING THE END OF RAIN CHANCES THROUGH
MONDAY. WITH A WESTERLY FLOW IN PLACE FOR SUNDAY...EXPECT A NICE
WARMUP WITH HIGHS IN THE UPPER 80S AND LOWER 90S. CAN NOT RULE OUT
AN ISOLATED STORM ACROSS THE FAR EASTERN COUNTIES SUNDAY
AFTERNOON AS LINGERING INSTABILITY REMAINS. A BACK DOOR COLD FRONT
WILL PUSH ACROSS THE AREA SUNDAY EVENING TO COOL THE OVERNIGHT
TEMPS INTO THE 50S AREAWIDE.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
A CLEAR NIGHT IS IN STORE FOR SUNDAY NIGHT WITH NORTHERLY WINDS
AND COOL TEMPERATURES FOLLOWED BY A PARTLY CLOUDY DAY ON MONDAY.
SOUTHERLY FLOW RETURNS TUESDAY AS WELL AS THE RAIN CHANCES FOR
SOUTH CENTRAL TEXAS. SEVERAL SHORT WAVES ARE EXPECTED TO PASS BY
AND TRIGGER SHOWERS AND STORMS THROUGH FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 81 61 89 57 76 / 40 40 - - -
AUSTIN BERGSTROM INTL AIRPORT 81 60 87 55 76 / 50 40 - - -
NEW BRAUNFELS MUNI AIRPORT 81 60 87 56 76 / 50 30 0 - -
BURNET MUNI AIRPORT 79 57 87 53 74 / 40 40 - - -
DEL RIO INTL AIRPORT 86 59 90 59 79 / 30 10 0 - 10
GEORGETOWN MUNI AIRPORT 79 59 87 54 74 / 40 40 10 - -
HONDO MUNI AIRPORT 82 59 88 57 78 / 40 20 0 - -
SAN MARCOS MUNI AIRPORT 81 61 86 56 75 / 50 40 0 - -
LA GRANGE - FAYETTE REGIONAL 80 63 86 57 75 / 50 40 20 10 10
SAN ANTONIO INTL AIRPORT 81 61 88 58 77 / 40 30 0 - -
STINSON MUNI AIRPORT 82 61 88 59 77 / 40 20 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...05
PUBLIC SERVICE/DATA COLLECTION...01
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1145 AM CDT SAT APR 18 2015
.DISCUSSION...
A STATIONARY FRONT WAS LOCATED JUST OFFSHORE ALONG THE COAST. THE
AIRMASS ALONG ABOUT A TWO-TIER COUNTY WIDTH ALONG THE COAST WAS
FAIRLY MOIST. NAMBUFR MODEL SOUNDINGS SHOW INCREASING INSTABILITY
DURING THE AFTERNOON WITH HEATING AND AS THE FRONTAL BOUNDARY
DRIFTS BACK INLAND. WATER VAPOR OVER THE PAST FEW HOURS SHOWED AN
APPROACHING SHORTWAVE TROUGH MOVING TOWARD THE AREA FROM THE
SOUTH. THE 06Z TEXAS TECH WRF AND 15Z HRRR BOTH FORECASTED BEST
CHANCES STARTING NEAR THE COAST BASICALLY ALONG AND EAST OF THE
HIGHWAY 59 CORRIDOR FROM MID AFTERNOON THROUGH MID EVENING.
ANOTHER UPPER LEVEL SHORTWAVE TROUGH WILL MOVE ACROSS SE TEXAS
LATE THIS EVENING FROM THE WEST. THIS MAY HELP GENERATE ADDITIONAL
SCATTERED STORMS DURING THE LATE EVENING AND INTO THE OVERNIGHT
PERIOD.
TWEAKED RAIN CHANCES MAINLY FOR TONIGHT AND ALSO TEMPERATURES FOR
TODAY.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 79 62 85 56 75 / 30 40 10 0 0
HOUSTON (IAH) 80 64 84 60 78 / 50 30 20 10 0
GALVESTON (GLS) 77 69 81 67 75 / 40 30 20 20 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...40
AVIATION/MARINE...41
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
941 AM CDT SAT APR 18 2015
.UPDATE...
MORNING UPPER AIR DATA AND SHORT-TERM MODEL GUIDANCE HAS
IDENTIFIED A SHORTWAVE TROUGH THAT IS PIVOTING AROUND THE UPPER
LOW OVER COLORADO. THIS SHORTWAVE WILL TRACK THROUGH TEXAS THIS
AFTERNOON AND EVENING. A DRY LINE IS FORECAST TO SET UP JUST WEST
OF THE CWA BORDER THIS AFTERNOON AND WILL BECOME THE FOCUS FOR
SCATTERED CONVECTION WHEN FORCING FROM THE SHORTWAVE TROUGH
ARRIVES. CONVECTIVE INITIATION SHOULD START AFTER 3 PM JUST WEST
OF THE CWA...WITH THESE STORMS MOVING/DEVELOPING GRADUALLY
NORTHEASTWARD INTO AND THROUGH THE CWA DURING THE LATE AFTERNOON
AND EVENING HOURS. GIVEN THE EXPECTED TIMING...HAVE LOWERED THE
POPS ALONG AND EAST OF I-35 FOR THE TODAY PERIOD AS ANY
RAIN/STORMS SHOULD HOLD OFF UNTIL THIS EVENING FOR THESE AREAS.
THERE IS A LACK OF LOW LEVEL WIND FLOW EVIDENT IN THE MORNING
DATA AND THE AIRMASS HAS BEEN FAIRLY WORKED OVER BY THE CONVECTION
FROM YESTERDAY AND LAST NIGHT. HOWEVER THE APPROACH OF THE
SHORTWAVE TROUGH WILL HELP TURN WINDS TO THE SOUTH BY THE
AFTERNOON...THEREBY INCREASING MOISTURE/THETA-E ADVECTION AND BULK
SHEAR VALUES ACROSS NORTH TEXAS. TEMPERATURES WILL ALSO WARM INTO
THE UPPER 70S AND LOWER 80S OVER NORTH TEXAS TODAY...WHICH WILL
YIELD GENERALLY 1000-2000 J/KG OF SURFACE BASED CAPE. THUS THE
AIRMASS SHOULD BE RECHARGED JUST ENOUGH TO SUPPORT SCATTERED
CONVECTION WITH A POTENTIAL FOR SEVERE WIND AND HAIL...ESPECIALLY
WEST OF I-35 IN THE LATE AFTERNOON HOURS. THE SEVERE THREAT WILL
DIMINISH AS THE STORMS HEAD EAST OF I-35 DUE TO THE LOSS OF
HEATING AND INCREASING CINH.
TR.92
&&
.AVIATION...
/ISSUED 707 AM CDT SAT APR 18 2015/
/12Z TAFS/
PREVIOUS RAINFALL AND LIGHT WINDS HAVE MADE THE TAFS QUITE
CHALLENGING THROUGH THE FIRST 3-6 HRS OF THE FORECAST. TO ADD TO
THE MIX...SUBSIDENCE AND SOME PARTIAL BREAKS IN THE MULTIPLE
LAYERS OF CLOUDS ARE CAUSING VSBYSO FLUCTUATE FROM P6SM TO 1/4SM
IN FOG FROM THE TAF SITES AND AREAS TO THE WEST. WILL CARRY
PREVAILING MVFR VSBYS W/TEMPO IFR-VLIFR VSBYS IN SHALLOW GROUND
FOG THROUGH LATE MORNING. AS WARMING TEMPERATURES AND STRONGER SE
WINDS ARRIVE BY MIDDAY...LOOK FOR VFR CIGS TO PREVAIL.
AN UPPER LOW OVER COLORADO WILL DRIFT OVER THE HIGH PLAINS OF
WESTERN KS BY TONIGHT. ANOTHER STORM CLUSTER WILL FORM OFF THE
WEST TX DRYLINE LATE THIS AFTERNOON AND MIGRATE EWD TOWARD I-35
AND THE TAF SITES IN THE 23Z-04Z TIME FRAME ONCE AGAIN. HAVE
BROUGHT STORMS IN AN HOUR SOONER AT AFW/FTW...BUT OTHERWISE WILL
CARRY A 2-HR TEMPO GROUP FOR THE HIGHEST CONFIDENCE TIMING FOR
TSRA WITH MVFR CIGS/CB. WITH THE UPPER LOW FURTHER EAST COMPARED
TO THE SAME TIME LAST NIGHT...WE DO NOT EXPECT THE CONVECTIVE
COMPLEX TO HANG AROUND QUITE AS LONG THROUGH 06Z LIKE FRIDAY
EVENING.
WE EXPECT LIGHT N/NE TO VRB SURFACE WINDS UNDER 5 KTS THROUGH
MID-LATE MORNING. THE ENVIRONMENTAL FLOW SHOULD TAKES OVER WITH
S/SE WINDS NEAR 10 KTS DURING AFTERNOON...BECOMING SOUTHERLY 5-10
KTS OVERNIGHT. IT/S HIGHLY POSSIBLE THAT THIS FLOW WILL BE DISTURBED
BY CONVECTIVE OUTFLOW ONCE AGAIN WITH DIFFERING DIRECTIONS AND
SPEEDS...BUT THAT WILL NEED TO BE ADDRESSED ON LATER TAFS WHEN
CONFIDENCE IS HIGHER.
MORE MVFR/IFR CONDITIONS MAY RETURN SUNDAY MORNING...BUT SHOULD
OCCUR MAINLY AFTER 12Z AND BEYOND THIS TAF CYCLE.
05/
&&
.PREV DISCUSSION... /ISSUED 415 AM CDT SAT APR 18 2015/
THE UPPER LOW THAT HAS BEEN PARKED OVER THE FOUR CORNERS IS
BEGINNING TO DISLODGE...AND BY THIS TIME SUNDAY MORNING IT WILL BE
OVER THE HIGH PLAINS NEAR THE COLORADO/KANSAS BORDER. THIS WILL
STEADILY VEER THE 700MB FLOW ACROSS WEST TEXAS TODAY...HELPING TO
NUDGE THE DRYLINE FARTHER EAST THAN IN RECENT DAYS. ALTHOUGH
WITHIN THE FIRST 24 HOURS OF THE LATEST GUIDANCE...OPERATIONAL
SOLUTIONS VARY WIDELY ON THE LATE AFTERNOON POSITION. ALTHOUGH THE
NAM IS AMONG THE FARTHEST WEST...WHICH IS UNUSUAL IN THIS
SCENARIO...THE CONSENSUS AMONG THE MESOSCALE GUIDANCE IS FOR THE
BOUNDARY TO REACH A VERNON-SAN ANGELO LINE NEAR PEAK HEATING. OUR
FORECAST WILL FAVOR THIS POSITION. BASED ON THE MID-LEVEL FLOW...
THERE SHOULD BE A BULGE NEAR THE RED RIVER. THE RAP AND TTU WRF
SHOW THIS CLEARLY...ADDING TO THE CONFIDENCE IN THEIR EVOLUTION OF
THE BOUNDARY TODAY.
THE ATMOSPHERE ACROSS NORTH TEXAS HAS BEEN WELL WORKED OVER. THIS
STABILITY...COUPLED WITH SUBSIDENCE IN THE WAKE OF A DEPARTING
DISTURBANCE...SHOULD PRECLUDE MUCH ADDITIONAL PRECIPITATION THIS
MORNING. WEAK LOW-LEVEL FLOW WILL RESULT IN NEGLIGIBLE MOIST
ADVECTION TODAY...AND DESTABILIZATION THIS AFTERNOON WILL BE
PRIMARILY GOVERNED BY SURFACE HEATING. ALTHOUGH THE I-35 CORRIDOR
WILL BE SLOW TO CLEAR TODAY...WESTERN NORTH TEXAS WILL SEE
SUFFICIENT SUNSHINE. EXPECT THUNDERSTORMS TO DEVELOP ALONG THE
DRYLINE MID TO LATE AFTERNOON. THOUGH RELATIVELY WEAK...THE
STEERING FLOW ALOFT SHOULD GUIDE THE ACTIVITY EAST THROUGH NORTH
TEXAS THIS EVENING. EVEN THOUGH THE SURFACE LAYER WILL BE
STEADILY STABILIZING AT THAT TIME...THE COLD POOL ASSOCIATED WITH
AN ORGANIZED MCS SHOULD PROLONG THE LIFESPAN OF ITS UPDRAFTS. THIS
WILL MAINTAIN A HAIL THREAT WELL INTO THE EVENING. THIS IS NOT THE
TYPICAL SETUP FOR A SQUALL LINE...BUT A WELL ORGANIZED COMPLEX
COULD POSE A WIND THREAT AS WELL. THE SPEED SHOULD BE SUFFICIENT
TO AVOID SIGNIFICANT FLOODING CONCERNS IN MOST AREAS...BUT WHERE
HEAVY RAIN HAS FALLEN RECENTLY...ADDITIONAL RAINFALL COULD
REAGGRAVATE FLOODING ISSUES.
AS THE UPPER LOW EJECTS THROUGH THE CENTRAL PLAINS...IT WILL SURGE
A COLD FRONT THROUGH THE REGION. WITH WIDESPREAD ACTIVITY THIS
EVENING...LARGE-SCALE SUBSIDENCE INVADING...AND VEERING LOW-LEVEL
FLOW EARLY SUNDAY...THE ATMOSPHERE SHOULD BE UNABLE TO PRODUCE ANY
FRONTAL PRECIPITATION. THE EXCEPTION WOULD BE EAST TEXAS...WHERE
THE MOISTURE PROFILE WILL BE MORE FAVORABLE...AND THE FRONT WILL
ARRIVE DURING THE WARM AFTERNOON HOURS. ABUNDANT APRIL SUNSHINE
AND A PRONOUNCED DOWNSLOPE WIND SHOULD OFFSET ANY COLD ADVECTION
BEHIND THE FRONT...AND TEMPERATURES SHOULD REACH THE 80S IN MANY
AREAS SUNDAY AFTERNOON. THE COOL AIR WILL ARRIVE SUNDAY NIGHT...
AND RURAL AREAS IN THE NORTHERN HALF OF THE CWA WILL LIKELY DIP
INTO THE 40S MONDAY AND TUESDAY MORNING.
ZONAL FLOW WILL PREVAIL MUCH OF THE UPCOMING WEEK. THE NEXT WAVE
EMBEDDED IN THIS WESTERLY FLOW WILL ARRIVE AROUND TUESDAY...BUT
AT THAT TIME...BOUNDARY LAYER MOISTURE MAY NOT HAVE BEEN ABLE TO
SUFFICIENTLY RECOVER. ADDITIONAL RIPPLES WILL FOLLOW...MAINTAINING
RAIN CHANCES. HOWEVER...POPS ARE NOTHING MORE THAN CLIMATOLOGY.
EXTENDED GUIDANCE IS IN REMARKABLY GOOD AGREEMENT WITH
UNSEASONABLE STRONG SHORTWAVE RIDGING AS THE NEXT UPPER LOW ENTERS
THE DESERT SOUTHWEST. GFS MOS TEMPS FOR THURSDAY AND FRIDAY ARE
NEAR 90 DEGREES. WITH PERFECT PROG 850MB TEMPS AROUND 20C...THIS
IS NOT OUT OF THE QUESTION. A BIT CONCERNED THAT CLOUD COVER MAY
PUT A DAMPER ON THE SPRING FEVER...AND FOR NOW...WILL KEEP
TEMPERATURES CLOSER TO CLIMATOLOGY.
25
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 79 60 80 53 73 / 20 50 10 5 5
WACO, TX 80 60 83 53 75 / 20 50 10 5 5
PARIS, TX 75 58 77 50 70 / 20 40 20 5 0
DENTON, TX 77 57 79 49 72 / 30 50 10 5 5
MCKINNEY, TX 78 58 79 51 73 / 20 50 10 5 0
DALLAS, TX 80 62 81 54 74 / 20 50 10 5 5
TERRELL, TX 78 60 80 52 74 / 20 50 10 5 5
CORSICANA, TX 79 61 82 52 75 / 20 50 20 5 5
TEMPLE, TX 79 60 84 53 74 / 20 50 10 5 5
MINERAL WELLS, TX 81 55 79 48 74 / 40 50 10 5 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
707 AM CDT SAT APR 18 2015
.AVIATION...
/12Z TAFS/
PREVIOUS RAINFALL AND LIGHT WINDS HAVE MADE THE TAFS QUITE
CHALLENGING THROUGH THE FIRST 3-6 HRS OF THE FORECAST. TO ADD TO
THE MIX...SUBSIDENCE AND SOME PARTIAL BREAKS IN THE MULTIPLE
LAYERS OF CLOUDS ARE CAUSING VSBYSO FLUCTUATE FROM P6SM TO 1/4SM
IN FOG FROM THE TAF SITES AND AREAS TO THE WEST. WILL CARRY
PREVAILING MVFR VSBYS W/TEMPO IFR-VLIFR VSBYS IN SHALLOW GROUND
FOG THROUGH LATE MORNING. AS WARMING TEMPERATURES AND STRONGER SE
WINDS ARRIVE BY MIDDAY...LOOK FOR VFR CIGS TO PREVAIL.
AN UPPER LOW OVER COLORADO WILL DRIFT OVER THE HIGH PLAINS OF
WESTERN KS BY TONIGHT. ANOTHER STORM CLUSTER WILL FORM OFF THE
WEST TX DRYLINE LATE THIS AFTERNOON AND MIGRATE EWD TOWARD I-35
AND THE TAF SITES IN THE 23Z-04Z TIME FRAME ONCE AGAIN. HAVE
BROUGHT STORMS IN AN HOUR SOONER AT AFW/FTW...BUT OTHERWISE WILL
CARRY A 2-HR TEMPO GROUP FOR THE HIGHEST CONFIDENCE TIMING FOR
TSRA WITH MVFR CIGS/CB. WITH THE UPPER LOW FURTHER EAST COMPARED
TO THE SAME TIME LAST NIGHT...WE DO NOT EXPECT THE CONVECTIVE
COMPLEX TO HANG AROUND QUITE AS LONG THROUGH 06Z LIKE FRIDAY
EVENING.
WE EXPECT LIGHT N/NE TO VRB SURFACE WINDS UNDER 5 KTS THROUGH
MID-LATE MORNING. THE ENVIRONMENTAL FLOW SHOULD TAKES OVER WITH
S/SE WINDS NEAR 10 KTS DURING AFTERNOON...BECOMING SOUTHERLY 5-10
KTS OVERNIGHT. IT/S HIGHLY POSSIBLE THAT THIS FLOW WILL BE DISTURBED
BY CONVECTIVE OUTFLOW ONCE AGAIN WITH DIFFERING DIRECTIONS AND
SPEEDS...BUT THAT WILL NEED TO BE ADDRESSED ON LATER TAFS WHEN
CONFIDENCE IS HIGHER.
MORE MVFR/IFR CONDITIONS MAY RETURN SUNDAY MORNING...BUT SHOULD
OCCUR MAINLY AFTER 12Z AND BEYOND THIS TAF CYCLE.
05/
&&
.PREV DISCUSSION... /ISSUED 415 AM CDT SAT APR 18 2015/
THE UPPER LOW THAT HAS BEEN PARKED OVER THE FOUR CORNERS IS
BEGINNING TO DISLODGE...AND BY THIS TIME SUNDAY MORNING IT WILL BE
OVER THE HIGH PLAINS NEAR THE COLORADO/KANSAS BORDER. THIS WILL
STEADILY VEER THE 700MB FLOW ACROSS WEST TEXAS TODAY...HELPING TO
NUDGE THE DRYLINE FARTHER EAST THAN IN RECENT DAYS. ALTHOUGH
WITHIN THE FIRST 24 HOURS OF THE LATEST GUIDANCE...OPERATIONAL
SOLUTIONS VARY WIDELY ON THE LATE AFTERNOON POSITION. ALTHOUGH THE
NAM IS AMONG THE FARTHEST WEST...WHICH IS UNUSUAL IN THIS
SCENARIO...THE CONSENSUS AMONG THE MESOSCALE GUIDANCE IS FOR THE
BOUNDARY TO REACH A VERNON-SAN ANGELO LINE NEAR PEAK HEATING. OUR
FORECAST WILL FAVOR THIS POSITION. BASED ON THE MID-LEVEL FLOW...
THERE SHOULD BE A BULGE NEAR THE RED RIVER. THE RAP AND TTU WRF
SHOW THIS CLEARLY...ADDING TO THE CONFIDENCE IN THEIR EVOLUTION OF
THE BOUNDARY TODAY.
THE ATMOSPHERE ACROSS NORTH TEXAS HAS BEEN WELL WORKED OVER. THIS
STABILITY...COUPLED WITH SUBSIDENCE IN THE WAKE OF A DEPARTING
DISTURBANCE...SHOULD PRECLUDE MUCH ADDITIONAL PRECIPITATION THIS
MORNING. WEAK LOW-LEVEL FLOW WILL RESULT IN NEGLIGIBLE MOIST
ADVECTION TODAY...AND DESTABILIZATION THIS AFTERNOON WILL BE
PRIMARILY GOVERNED BY SURFACE HEATING. ALTHOUGH THE I-35 CORRIDOR
WILL BE SLOW TO CLEAR TODAY...WESTERN NORTH TEXAS WILL SEE
SUFFICIENT SUNSHINE. EXPECT THUNDERSTORMS TO DEVELOP ALONG THE
DRYLINE MID TO LATE AFTERNOON. THOUGH RELATIVELY WEAK...THE
STEERING FLOW ALOFT SHOULD GUIDE THE ACTIVITY EAST THROUGH NORTH
TEXAS THIS EVENING. EVEN THOUGH THE SURFACE LAYER WILL BE
STEADILY STABILIZING AT THAT TIME...THE COLD POOL ASSOCIATED WITH
AN ORGANIZED MCS SHOULD PROLONG THE LIFESPAN OF ITS UPDRAFTS. THIS
WILL MAINTAIN A HAIL THREAT WELL INTO THE EVENING. THIS IS NOT THE
TYPICAL SETUP FOR A SQUALL LINE...BUT A WELL ORGANIZED COMPLEX
COULD POSE A WIND THREAT AS WELL. THE SPEED SHOULD BE SUFFICIENT
TO AVOID SIGNIFICANT FLOODING CONCERNS IN MOST AREAS...BUT WHERE
HEAVY RAIN HAS FALLEN RECENTLY...ADDITIONAL RAINFALL COULD
REAGGRAVATE FLOODING ISSUES.
AS THE UPPER LOW EJECTS THROUGH THE CENTRAL PLAINS...IT WILL SURGE
A COLD FRONT THROUGH THE REGION. WITH WIDESPREAD ACTIVITY THIS
EVENING...LARGE-SCALE SUBSIDENCE INVADING...AND VEERING LOW-LEVEL
FLOW EARLY SUNDAY...THE ATMOSPHERE SHOULD BE UNABLE TO PRODUCE ANY
FRONTAL PRECIPITATION. THE EXCEPTION WOULD BE EAST TEXAS...WHERE
THE MOISTURE PROFILE WILL BE MORE FAVORABLE...AND THE FRONT WILL
ARRIVE DURING THE WARM AFTERNOON HOURS. ABUNDANT APRIL SUNSHINE
AND A PRONOUNCED DOWNSLOPE WIND SHOULD OFFSET ANY COLD ADVECTION
BEHIND THE FRONT...AND TEMPERATURES SHOULD REACH THE 80S IN MANY
AREAS SUNDAY AFTERNOON. THE COOL AIR WILL ARRIVE SUNDAY NIGHT...
AND RURAL AREAS IN THE NORTHERN HALF OF THE CWA WILL LIKELY DIP
INTO THE 40S MONDAY AND TUESDAY MORNING.
ZONAL FLOW WILL PREVAIL MUCH OF THE UPCOMING WEEK. THE NEXT WAVE
EMBEDDED IN THIS WESTERLY FLOW WILL ARRIVE AROUND TUESDAY...BUT
AT THAT TIME...BOUNDARY LAYER MOISTURE MAY NOT HAVE BEEN ABLE TO
SUFFICIENTLY RECOVER. ADDITIONAL RIPPLES WILL FOLLOW...MAINTAINING
RAIN CHANCES. HOWEVER...POPS ARE NOTHING MORE THAN CLIMATOLOGY.
EXTENDED GUIDANCE IS IN REMARKABLY GOOD AGREEMENT WITH
UNSEASONABLE STRONG SHORTWAVE RIDGING AS THE NEXT UPPER LOW ENTERS
THE DESERT SOUTHWEST. GFS MOS TEMPS FOR THURSDAY AND FRIDAY ARE
NEAR 90 DEGREES. WITH PERFECT PROG 850MB TEMPS AROUND 20C...THIS
IS NOT OUT OF THE QUESTION. A BIT CONCERNED THAT CLOUD COVER MAY
PUT A DAMPER ON THE SPRING FEVER...AND FOR NOW...WILL KEEP
TEMPERATURES CLOSER TO CLIMATOLOGY.
25
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 79 60 80 53 73 / 40 50 10 5 5
WACO, TX 80 60 83 53 75 / 40 50 10 5 5
PARIS, TX 75 58 77 50 70 / 50 40 20 5 0
DENTON, TX 77 57 79 49 72 / 40 50 10 5 5
MCKINNEY, TX 78 58 79 51 73 / 40 50 10 5 0
DALLAS, TX 80 62 81 54 74 / 40 50 10 5 5
TERRELL, TX 78 60 80 52 74 / 40 50 10 5 5
CORSICANA, TX 79 61 82 52 75 / 40 50 20 5 5
TEMPLE, TX 79 60 84 53 74 / 40 50 10 5 5
MINERAL WELLS, TX 81 55 79 48 74 / 40 50 10 5 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/25
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
631 AM CDT Sat Apr 18 2015
.AVIATION...
/12Z TAFS/
Two upper level disturbance will bring a round of storms to most
TAF sites this morning and again this afternoon. Latest radar data
is showing an area of storms moving east and northeast towards
KSOA and KJCT and could reach those sites between 12Z and 15Z.
Main impacts will be gusty winds, brief heavy rain, lightning and
low visibilities. The IFR Cigs should gradually improve to VFR shortly
after 15Z. The next round of storms may form along the dryline
after 18Z at KSOA, KBBD and KJCT. A few of these may become severe
and produce large hail, damaging winds and very heavy rainfall.
&&
.PREV DISCUSSION... /ISSUED 420 AM CDT Sat Apr 18 2015/
SHORT TERM...
(Today and Tonight)
There is a threat for severe thunderstorms across the eastern half
of West Central Texas today as an upper level trough associated with
the upper low near the Four Corners moves across the region. The
main threats will be large hail and damaging winds. SPC has placed
much of the area east of the dryline in a slight risk for severe
thunderstorms today.
Latest radar is showing showers developing across the mountains in
northern Mexico, south of Sanderson, in association with the next
approaching shortwave as can be seen on water vapor satellite
imagery. This could bring a round of showers and thunderstorms to
West Central Texas this morning before the main upper trough moves
across later this afternoon.
The dryline is forecast to move east today as the RUC model progs
this front from Haskell to just east of San Angelo to Sonora by
early evening. This dryline should trigger scattered thunderstorms
this afternoon as the following ingredients come together: dewpoints
ranging from the upper 50s to the lower 60s, moderate 0-6km shear,
MU CAPE Values 1500-2000 J/KG, a weak capping inversion, approaching
upper trough and a right rear entrance region of the southern stream
upper level jet flowing across the area. These parameters should
set the stage for the development of a few supercells today,
resulting in large hail and damaging winds. These storms may
continue into the early evening hours before dissipating.
Highest Pops were placed across the Northwest Hill Country extending
north to Brownwood. Went closer to the warmer MAV MOS for
temps as the dry warm air invades the western part of the region
today.
26
LONG TERM...
(Sunday through Friday)
Cold front will move through Sunday. Dry southwest to west winds
ahead of the front will not only preclude rain chances, but also
give a boost to temperatures, being downslope compression. Still,
cold advection will bring cooler temperatures Sunday, with highs
in the 70s.
Isolated dryline thunderstorms possible mid and late week. West
Central Texas will be under a broad upper ridge, so widespread
showers or thunderstorms not expected. Could see a few highs
approach 90s, especially Wednesday and Thursday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 82 55 79 49 72 / 30 20 5 5 5
San Angelo 84 54 82 50 75 / 30 10 5 5 5
Junction 82 56 85 52 75 / 50 30 5 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
26/99/99
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
611 AM CDT SAT APR 18 2015
.AVIATION...
CEILINGS ARE IFR/MVFR AROUND THE AREA AIRPORTS THIS MORNING AND
CONDITIONS SHOULD SLOWLY IMPROVE TO VFR BY EARLY AFTERNOON.
CONVECTION HAS DEVELOPED WEST OF KDRT AND WILL SHOW VCTS FOR THE
FIRST FEW HOURS OF THE VALID TAF PERIOD. CONFIDENCE REGARDING
CONVECTION CHANCES THIS AFTERNOON IS NOT VERY HIGH. THE MOST
LIKELY SCENARIO IS FOR THIS ELEVATED CONVECTION TO MOVE EAST THIS
MORNING AND THE ATMOSPHERE TO REENERGIZE BY THE LATE AFTERNOON
HOURS. THERE SHOULD BE A SURFACE CONVERGENCE ZONE DEVELOPING WEST
OF THE I-35 TAF SITES. THE MOST LIKELY TIME THESE WOULD BE TO THE
TERMINALS WOULD BE AROUND 22-03Z. WILL HANDLE THIS WITH A VCTS
FOR NOW. ADDITIONAL MVFR RESTRICTIONS ARE POSSIBLE TONIGHT...BUT
IFR IS NOT ANTICIPATED AS SLIGHTLY DRIER AIR MOVES INTO THE AREA.
HAMPSHIRE
&&
.PREV DISCUSSION... /ISSUED 401 AM CDT SAT APR 18 2015/
SHORT TERM (TODAY THROUGH SUNDAY)...
AN UPPER LEVEL STORM SYSTEM IS CENTERED ACROSS COLORADO EARLY THIS
MORNING. THIS SYSTEM IS FORECAST TO MOVE TO THE NORTHEAST AND THEN
EAST THROUGH THE WEEKEND AND BECOMES AN OPEN WAVE LATE SUNDAY
AFTERNOON. SEVERAL SHORT WAVES ASSOCIATED WITH THE UPPER LEVEL
LOW ARE ANTICIPATED TO PUSH ACROSS THE AREA FOR THE NEXT 12 TO 18
HOURS AND ENHANCE STORM DEVELOPMENT LATE THIS MORNING THROUGH THE
EVENING HOURS. AT LOWER LEVELS...A PRE-FRONTAL TROUGH/DRY-LINE
WILL SERVE AS THE MAIN FOCUS AS STORMS FORM IN THE MOIST AND
WARM SECTOR. BY THIS AFTERNOON...DEWPOINT TEMPERATURES ARE
FORECAST TO REACH THE MID TO UPPER 60S WITH AREA SOUNDINGS
SUGGESTING ML CAPES OF 1500 TO 2500J/KG AND LI RANGING FROM -5 TO
-10 FOR LARGE TO EXTREME INSTABILITY. THEREFORE...ANY STORM THAT
DOES DEVELOP HAS THE POTENTIAL TO BECOME STRONG OR SEVERE. PER SPC
DAY 1 CONVECTIVE OUTLOOK...ALL OF SOUTH CENTRAL TEXAS WITH THE
EXCEPTION OF THE NORTHWEST PORTION OF VAL VERDE COUNTY...IS UNDER
A SLIGHT RISK OF SEVERE THUNDERSTORMS.
HIRES SOLUTIONS ARE HAVING DIFFICULTIES ON TIMING AND AREAS OF
STORM DEVELOPMENT INITIALLY. THE HRRR STARTS CONVECTION ACROSS THE
SOUTHERN COUNTIES AS AN MCS DEVELOPS ACROSS THE COASTAL PLAINS AND
MOVE TO THE EAST. THE TEXAS TECH IS MORE AGGRESSIVE ON FORMING
STORMS AHEAD OF THE DRY-LINE AS IT PUSHES TO THE EAST AND OVER THE
EDWARDS PLATEAU/HILL COUNTRY AREA. THE HRRR DOES DEVELOP
CONVECTION AHEAD OF THE DRY-LINE THIS AFTERNOON BUT NOWHERE NEAR
TEXAS TECH MODEL. THEREFORE...THE SHORT-TERM/FIRST PERIOD CONSISTS
ON A BLEND OF THE HRRR/TEXAS TECH SOLUTIONS. BY LATER THIS
EVENING...MID LEVEL WESTERLY WILL TAKE OVER AS THE UPPER LEVEL LOW
PUSHES TO THE EAST...MARKING THE END OF RAIN CHANCES THROUGH
MONDAY. WITH A WESTERLY FLOW IN PLACE FOR SUNDAY...EXPECT A NICE
WARMUP WITH HIGHS IN THE UPPER 80S AND LOWER 90S. CAN NOT RULE OUT
AN ISOLATED STORM ACROSS THE FAR EASTERN COUNTIES SUNDAY
AFTERNOON AS LINGERING INSTABILITY REMAINS. A BACK DOOR COLD FRONT
WILL PUSH ACROSS THE AREA SUNDAY EVENING TO COOL THE OVERNIGHT
TEMPS INTO THE 50S AREAWIDE.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
A CLEAR NIGHT IS IN STORE FOR SUNDAY NIGHT WITH NORTHERLY WINDS
AND COOL TEMPERATURES FOLLOWED BY A PARTLY CLOUDY DAY ON MONDAY.
SOUTHERLY FLOW RETURNS TUESDAY AS WELL AS THE RAIN CHANCES FOR
SOUTH CENTRAL TEXAS. SEVERAL SHORT WAVES ARE EXPECTED TO PASS BY
AND TRIGGER SHOWERS AND STORMS THROUGH FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 81 61 89 57 76 / 40 40 - - -
AUSTIN BERGSTROM INTL AIRPORT 81 60 87 55 76 / 50 40 - - -
NEW BRAUNFELS MUNI AIRPORT 81 60 87 56 76 / 50 30 0 - -
BURNET MUNI AIRPORT 79 57 87 53 74 / 40 40 - - -
DEL RIO INTL AIRPORT 86 59 90 59 79 / 30 10 0 - 10
GEORGETOWN MUNI AIRPORT 79 59 87 54 74 / 40 40 10 - -
HONDO MUNI AIRPORT 82 59 88 57 78 / 40 20 0 - -
SAN MARCOS MUNI AIRPORT 81 61 86 56 75 / 50 40 0 - -
LA GRANGE - FAYETTE REGIONAL 80 63 86 57 75 / 50 40 20 10 10
SAN ANTONIO INTL AIRPORT 81 61 88 58 77 / 40 30 0 - -
STINSON MUNI AIRPORT 82 61 88 59 77 / 40 20 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...29
SYNOPTIC/GRIDS...17
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
420 AM CDT Sat Apr 18 2015
.SHORT TERM...
(Today and Tonight)
There is a threat for severe thunderstorms across the eastern half
of West Central Texas today as an upper level trough associated with
the upper low near the Four Corners moves across the region. The
main threats will be large hail and damaging winds. SPC has placed
much of the area east of the dryline in a slight risk for severe
thunderstorms today.
Latest radar is showing showers developing across the mountains in
northern Mexico, south of Sanderson, in association with the next
approaching shortwave as can be seen on water vapor satellite
imagery. This could bring a round of showers and thunderstorms to
West Central Texas this morning before the main upper trough moves
across later this afternoon.
The dryline is forecast to move east today as the RUC model progs
this front from Haskell to just east of San Angelo to Sonora by
early evening. This dryline should trigger scattered thunderstorms
this afternoon as the following ingredients come together: dewpoints
ranging from the upper 50s to the lower 60s, moderate 0-6km shear,
MU CAPE Values 1500-2000 J/KG, a weak capping inversion, approaching
upper trough and a right rear entrance region of the southern stream
upper level jet flowing across the area. These parameters should
set the stage for the development of a few supercells today,
resulting in large hail and damaging winds. These storms may
continue into the early evening hours before dissipating.
Highest Pops were placed across the Northwest Hill Country extending
north to Brownwood. Went closer to the warmer MAV MOS for
temps as the dry warm air invades the western part of the region
today.
26
.LONG TERM...
(Sunday through Friday)
Cold front will move through Sunday. Dry southwest to west winds
ahead of the front will not only preclude rain chances, but also
give a boost to temperatures, being downslope compression. Still,
cold advection will bring cooler temperatures Sunday, with highs
in the 70s.
Isolated dryline thunderstorms possible mid and late week. West
Central Texas will be under a broad upper ridge, so widespread
showers or thunderstorms not expected. Could see a few highs
approach 90s, especially Wednesday and Thursday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 82 55 79 49 72 / 30 20 5 5 5
San Angelo 84 54 82 50 75 / 30 10 5 5 5
Junction 82 56 85 52 75 / 50 30 5 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
26/04
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
415 AM CDT SAT APR 18 2015
.DISCUSSION...
THE UPPER LOW THAT HAS BEEN PARKED OVER THE FOUR CORNERS IS
BEGINNING TO DISLODGE...AND BY THIS TIME SUNDAY MORNING IT WILL BE
OVER THE HIGH PLAINS NEAR THE COLORADO/KANSAS BORDER. THIS WILL
STEADILY VEER THE 700MB FLOW ACROSS WEST TEXAS TODAY...HELPING TO
NUDGE THE DRYLINE FARTHER EAST THAN IN RECENT DAYS. ALTHOUGH
WITHIN THE FIRST 24 HOURS OF THE LATEST GUIDANCE...OPERATIONAL
SOLUTIONS VARY WIDELY ON THE LATE AFTERNOON POSITION. ALTHOUGH THE
NAM IS AMONG THE FARTHEST WEST...WHICH IS UNUSUAL IN THIS
SCENARIO...THE CONSENSUS AMONG THE MESOSCALE GUIDANCE IS FOR THE
BOUNDARY TO REACH A VERNON-SAN ANGELO LINE NEAR PEAK HEATING. OUR
FORECAST WILL FAVOR THIS POSITION. BASED ON THE MID-LEVEL FLOW...
THERE SHOULD BE A BULGE NEAR THE RED RIVER. THE RAP AND TTU WRF
SHOW THIS CLEARLY...ADDING TO THE CONFIDENCE IN THEIR EVOLUTION OF
THE BOUNDARY TODAY.
THE ATMOSPHERE ACROSS NORTH TEXAS HAS BEEN WELL WORKED OVER. THIS
STABILITY...COUPLED WITH SUBSIDENCE IN THE WAKE OF A DEPARTING
DISTURBANCE...SHOULD PRECLUDE MUCH ADDITIONAL PRECIPITATION THIS
MORNING. WEAK LOW-LEVEL FLOW WILL RESULT IN NEGLIGIBLE MOIST
ADVECTION TODAY...AND DESTABILIZATION THIS AFTERNOON WILL BE
PRIMARILY GOVERNED BY SURFACE HEATING. ALTHOUGH THE I-35 CORRIDOR
WILL BE SLOW TO CLEAR TODAY...WESTERN NORTH TEXAS WILL SEE
SUFFICIENT SUNSHINE. EXPECT THUNDERSTORMS TO DEVELOP ALONG THE
DRYLINE MID TO LATE AFTERNOON. THOUGH RELATIVELY WEAK...THE
STEERING FLOW ALOFT SHOULD GUIDE THE ACTIVITY EAST THROUGH NORTH
TEXAS THIS EVENING. EVEN THOUGH THE SURFACE LAYER WILL BE
STEADILY STABILIZING AT THAT TIME...THE COLD POOL ASSOCIATED WITH
AN ORGANIZED MCS SHOULD PROLONG THE LIFESPAN OF ITS UPDRAFTS. THIS
WILL MAINTAIN A HAIL THREAT WELL INTO THE EVENING. THIS IS NOT THE
TYPICAL SETUP FOR A SQUALL LINE...BUT A WELL ORGANIZED COMPLEX
COULD POSE A WIND THREAT AS WELL. THE SPEED SHOULD BE SUFFICIENT
TO AVOID SIGNIFICANT FLOODING CONCERNS IN MOST AREAS...BUT WHERE
HEAVY RAIN HAS FALLEN RECENTLY...ADDITIONAL RAINFALL COULD
REAGGRAVATE FLOODING ISSUES.
AS THE UPPER LOW EJECTS THROUGH THE CENTRAL PLAINS...IT WILL SURGE
A COLD FRONT THROUGH THE REGION. WITH WIDESPREAD ACTIVITY THIS
EVENING...LARGE-SCALE SUBSIDENCE INVADING...AND VEERING LOW-LEVEL
FLOW EARLY SUNDAY...THE ATMOSPHERE SHOULD BE UNABLE TO PRODUCE ANY
FRONTAL PRECIPITATION. THE EXCEPTION WOULD BE EAST TEXAS...WHERE
THE MOISTURE PROFILE WILL BE MORE FAVORABLE...AND THE FRONT WILL
ARRIVE DURING THE WARM AFTERNOON HOURS. ABUNDANT APRIL SUNSHINE
AND A PRONOUNCED DOWNSLOPE WIND SHOULD OFFSET ANY COLD ADVECTION
BEHIND THE FRONT...AND TEMPERATURES SHOULD REACH THE 80S IN MANY
AREAS SUNDAY AFTERNOON. THE COOL AIR WILL ARRIVE SUNDAY NIGHT...
AND RURAL AREAS IN THE NORTHERN HALF OF THE CWA WILL LIKELY DIP
INTO THE 40S MONDAY AND TUESDAY MORNING.
ZONAL FLOW WILL PREVAIL MUCH OF THE UPCOMING WEEK. THE NEXT WAVE
EMBEDDED IN THIS WESTERLY FLOW WILL ARRIVE AROUND TUESDAY...BUT
AT THAT TIME...BOUNDARY LAYER MOISTURE MAY NOT HAVE BEEN ABLE TO
SUFFICIENTLY RECOVER. ADDITIONAL RIPPLES WILL FOLLOW...MAINTAINING
RAIN CHANCES. HOWEVER...POPS ARE NOTHING MORE THAN CLIMATOLOGY.
EXTENDED GUIDANCE IS IN REMARKABLY GOOD AGREEMENT WITH
UNSEASONABLE STRONG SHORTWAVE RIDGING AS THE NEXT UPPER LOW ENTERS
THE DESERT SOUTHWEST. GFS MOS TEMPS FOR THURSDAY AND FRIDAY ARE
NEAR 90 DEGREES. WITH PERFECT PROG 850MB TEMPS AROUND 20C...THIS
IS NOT OUT OF THE QUESTION. A BIT CONCERNED THAT CLOUD COVER MAY
PUT A DAMPER ON THE SPRING FEVER...AND FOR NOW...WILL KEEP
TEMPERATURES CLOSER TO CLIMATOLOGY.
25
&&
.AVIATION...
/ISSUED 635 PM CDT FRI APR 17 2015/
FOR THE 00Z TAFS...TRACKING THE NORTH/SOUTH ORIENTED LINE OF
THUNDERSTORMS MOVING EAST TOWARDS THE DFW METROPLEX IS THE PRIMARY
FORECAST CONCERN.
THE LINE OF STORMS JUST WEST OF TARRANT COUNTY HAS BEEN LOSING
INTENSITY FOR THE MOST PART...AND AS A RESULT HAS BEEN
CONSISTENTLY SLOWLY DOWN WITH REGARDS TO ITS EASTERLY PROGRESS.
THE MOST INTENSE PART OF THE LINE IS LOCATED OVER FAR SOUTHWESTERN
TARRANT COUNTY...MOVING EAST NOW AT ABOUT 20 MPH. FOR THE MOST
PART THIS LINE OF STORMS WILL BE CAPABLE OF PRODUCING 20 TO 30 MPH
WIND GUSTS...HEAVY RAINFALL...AND FREQUENT LIGHTNING AS IT MOVES
OVER AREA TAF SITES.
THE MORE INTENSE LINE OF STORMS OVER FAR SOUTHERN TARRANT COUNTY
WILL BE CAPABLE OF PRODUCING WIND GUSTS OF 40 TO 45 MPH AS WELL AS
HEAVY RAINFALL AND FREQUENT LIGHTNING. THIS MORE INTENSE LINE OF
STORMS APPEARS ON TRACK TO MOVE OVER KGKY AIRPORT...REMAINING JUST
SOUTH OF KFTW...KDFW...KAFW...AND KDAL AIRPORTS.
WILL LIKELY HAVE TO KEEP AMENDING THE TAFS FOR TIMING
CONSIDERATIONS AS THE STORMS ROLL ACROSS THE DFW AREA. BEHIND THE
MAIN LINE OF STORMS...LIGHT RAIN SHOWERS ARE EXPECTED TO PERSIST
FOR A COUPLE OF HOURS BEFORE ALL PRECIPITATION ENDS ACROSS THE DFW
AREA.
OTHER THAN STORMS...IFR CIGS ARE EXPECTED TO BUILD OVER NORTH AND
CENTRAL TEXAS FROM THE SOUTH EARLY TOMORROW MORNING. DID NOT SEE
ANY REASON TO CHANGE THE TIMING OF THE ONSET OF IFR CIGS FROM THE
PREVIOUS FORECAST...BUT MAY NEED TO ADJUST THE TIMING ONCE STORMS
HAVE DISSIPATED...ALLOWING FOR AN EVALUATION OF WHERE OUTFLOW
BOUNDARIES END UP. DID NOT HAVE ENOUGH CONFIDENCE IN THE TIMING OF
STORMS ON SATURDAY TO INCLUDE THEM IN THE TAFS AT THIS TIME.
STORMS MAY ONCE AGAIN THREATEN AREA TAF SITES TOMORROW AFTERNOON
OR EVENING.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 79 60 80 53 73 / 40 50 10 5 5
WACO, TX 80 60 83 53 75 / 40 50 10 5 5
PARIS, TX 75 58 77 50 70 / 50 40 20 5 0
DENTON, TX 77 57 79 49 72 / 40 50 10 5 5
MCKINNEY, TX 78 58 79 51 73 / 40 50 10 5 0
DALLAS, TX 80 62 81 54 74 / 40 50 10 5 5
TERRELL, TX 78 60 80 52 74 / 40 50 10 5 5
CORSICANA, TX 79 61 82 52 75 / 40 50 20 5 5
TEMPLE, TX 79 60 84 53 74 / 40 50 10 5 5
MINERAL WELLS, TX 81 55 79 48 74 / 40 50 10 5 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/25
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
411 AM CDT Sat Apr 18 2015
.SHORT TERM...
(Today and Tonight)
There is a threat for severe thunderstorms across the eastern half
of West Central Texas today as an upper level trough associated with
the upper low near the Four Corners moves across the region. The
main threats will be large hail and damaging winds. SPC has placed
much of the area east of the dryline in a slight risk for severe
thunderstorms today.
The dryline is forecast to move east today as the RUC model progs
this front from Haskell to just east of San Angelo to Sonora by
early evening. This dryline should trigger scattered
thunderstorms this afternoon as the following ingredients come
together: dewpoints ranging from the upper 50s to the lower 60s,
moderate 0-6km shear, MU CAPE Values 1500-2000 J/KG, a weak capping
inversion, and a right rear entrance region of the southern stream
upper level jet flowing across the area. These parameters should
set the stage for the development of a few supercells today,
resulting in large hail and damaging winds. These storms may
continue into the early evening hours before dissipating.
Highest Pops were placed across the Northwest Hill Country extending
north to Brownwood. Went closer to the warmer MAV MOS for
temps as the dry warm air invades the western part of the region
today.
26
.LONG TERM...
(Sunday through Friday)
Cold front will move through Sunday. Dry southwest to west winds
ahead of the front will not only preclude rain chances, but also
give a boost to temperatures, being downslope compression. Still,
cold advection will bring cooler temperatures Sunday, with highs
in the 70s.
Isolated dryline thunderstorms possible mid and late week. West
Central Texas will be under a broad upper ridge, so widespread
showers or thunderstorms not expected. Could see a few highs
approach 90s, especially Wednesday and Thursday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 82 55 79 49 72 / 30 20 5 5 5
San Angelo 84 54 82 50 75 / 30 10 5 5 5
Junction 82 56 85 52 75 / 50 30 5 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
26/04
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
401 AM CDT SAT APR 18 2015
.SHORT TERM (TODAY THROUGH SUNDAY)...
AN UPPER LEVEL STORM SYSTEM IS CENTERED ACROSS COLORADO EARLY THIS
MORNING. THIS SYSTEM IS FORECAST TO MOVE TO THE NORTHEAST AND THEN
EAST THROUGH THE WEEKEND AND BECOMES AN OPEN WAVE LATE SUNDAY
AFTERNOON. SEVERAL SHORT WAVES ASSOCIATED WITH THE UPPER LEVEL
LOW ARE ANTICIPATED TO PUSH ACROSS THE AREA FOR THE NEXT 12 TO 18
HOURS AND ENHANCE STORM DEVELOPMENT LATE THIS MORNING THROUGH THE
EVENING HOURS. AT LOWER LEVELS...A PRE-FRONTAL TROUGH/DRY-LINE
WILL SERVE AS THE MAIN FOCUS AS STORMS FORM IN THE MOIST AND
WARM SECTOR. BY THIS AFTERNOON...DEWPOINT TEMPERATURES ARE
FORECAST TO REACH THE MID TO UPPER 60S WITH AREA SOUNDINGS
SUGGESTING ML CAPES OF 1500 TO 2500J/KG AND LI RANGING FROM -5 TO
-10 FOR LARGE TO EXTREME INSTABILITY. THEREFORE...ANY STORM THAT
DOES DEVELOP HAS THE POTENTIAL TO BECOME STRONG OR SEVERE. PER SPC
DAY 1 CONVECTIVE OUTLOOK...ALL OF SOUTH CENTRAL TEXAS WITH THE
EXCEPTION OF THE NORTHWEST PORTION OF VAL VERDE COUNTY...IS UNDER
A SLIGHT RISK OF SEVERE THUNDERSTORMS.
HIRES SOLUTIONS ARE HAVING DIFFICULTIES ON TIMING AND AREAS OF
STORM DEVELOPMENT INITIALLY. THE HRRR STARTS CONVECTION ACROSS THE
SOUTHERN COUNTIES AS AN MCS DEVELOPS ACROSS THE COASTAL PLAINS AND
MOVE TO THE EAST. THE TEXAS TECH IS MORE AGGRESSIVE ON FORMING
STORMS AHEAD OF THE DRY-LINE AS IT PUSHES TO THE EAST AND OVER THE
EDWARDS PLATEAU/HILL COUNTRY AREA. THE HRRR DOES DEVELOP
CONVECTION AHEAD OF THE DRY-LINE THIS AFTERNOON BUT NOWHERE NEAR
TEXAS TECH MODEL. THEREFORE...THE SHORT-TERM/FIRST PERIOD CONSISTS
ON A BLEND OF THE HRRR/TEXAS TECH SOLUTIONS. BY LATER THIS
EVENING...MID LEVEL WESTERLY WILL TAKE OVER AS THE UPPER LEVEL LOW
PUSHES TO THE EAST...MARKING THE END OF RAIN CHANCES THROUGH
MONDAY. WITH A WESTERLY FLOW IN PLACE FOR SUNDAY...EXPECT A NICE
WARMUP WITH HIGHS IN THE UPPER 80S AND LOWER 90S. CAN NOT RULE OUT
AN ISOLATED STORMS ACROSS THE FAR EASTERN COUNTIES SUNDAY
AFTERNOON AS LINGERING INSTABILITY REMAINS. A BACK DOOR COLD FRONT
WILL PUSH ACROSS THE AREA SUNDAY EVENING TO COOL THE OVERNIGHT
TEMPS INTO THE 50S AREAWIDE.
&&
.LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
A CLEAR NIGHT IS IN STORE FOR SUNDAY NIGHT WITH NORTHERLY WINDS
AND COOL TEMPERATURES FOLLOWED BY A PARTLY CLOUDY DAY ON MONDAY.
SOUTHERLY FLOW RETURNS TUESDAY AS WELL AS THE RAIN CHANCES FOR
SOUTH CENTRAL TEXAS. SEVERAL SHORT WAVES ARE EXPECTED TO PASS BY
AND TRIGGER SHOWERS AND STORMS THROUGH FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 81 61 89 57 76 / 40 40 - - -
AUSTIN BERGSTROM INTL AIRPORT 81 60 87 55 76 / 50 40 - - -
NEW BRAUNFELS MUNI AIRPORT 81 60 87 56 76 / 50 30 0 - -
BURNET MUNI AIRPORT 79 57 87 53 74 / 40 40 - - -
DEL RIO INTL AIRPORT 86 59 90 59 79 / 30 10 0 - 10
GEORGETOWN MUNI AIRPORT 79 59 87 54 74 / 40 40 10 - -
HONDO MUNI AIRPORT 82 59 88 57 78 / 40 20 0 - -
SAN MARCOS MUNI AIRPORT 81 61 86 56 75 / 50 40 0 - -
LA GRANGE - FAYETTE REGIONAL 80 63 86 57 75 / 50 40 20 10 10
SAN ANTONIO INTL AIRPORT 81 61 88 58 77 / 40 30 0 - -
STINSON MUNI AIRPORT 82 61 88 59 77 / 40 20 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...29
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1147 PM CDT FRI APR 17 2015
.UPDATE...
SOME MINOR CHANGES TO THE FORECAST INCLUDE INSERTING A MENTION OF
FOG AND INCREASING MINIMUM TEMPERATURES FOR TONIGHT. THE DRYLINE
HAS MOVED FARTHER WEST THAN MODELS FORECAST BRINGING IN MOIST AIR
ON THE CAPROCK. MODELS HAVE TRENDED TOWARDS DEVELOPING FOG IN THE
MOIST AIR THROUGH MID MORNING. FURTHERMORE...T/TD SPREADS OFF THE
CAPROCK WERE ALREADY RUNNING BETWEEN 1-2 DEGREES. IT IS STILL
NEBULOUS ON WHETHER AREAS ON THE CAPROCK WILL SEE FOG OR NOT. THE
DRYLINE RECENTLY ENCOUNTERED A WESTWARD MOVING BOUNDARY WHICH HAS
GREATLY SLOWED THE PROGRESSION OF THE DRYLINE. AT SOME POINT...THE
DRYLINE WILL LIKELY BEGIN MOVING EAST. OVERNIGHT TEMPERATURES WERE
GENERALLY RAISED ON EASTERN PORTIONS OF THE CAPROCK WHERE THIS
MOISTURE HAS INVADED.
&&
.AVIATION...
VERY MOIST AIR NEAR THE SURFACE WILL LIKELY BRING FOG INTO THE
KCDS TERMINAL EARLY SATURDAY MORNING. IT REMAINS UNCLEAR ON
WHETHER FOG WILL MAKE IT INTO KLBB OR KPVW. A DRYLINE BOUNDARY IS
CLOSE TO BOTH TERMINALS WHICH MAKES IT UNCERTAIN ON WHETHER THE
LOW LEVEL MOISTURE WILL STAY IN THE VICINITY OF EITHER TERMINAL.
IF MOISTURE DOES HANG ON...THEN FOG AND LOW CIGS WILL BE POSSIBLE
AT KLBB AND KPVW. BREEZY WINDS WILL DEVELOP OUT OF THE SOUTHWEST
DURING THE AFTERNOON AT ALL TAF SITES.
&&
PREV DISCUSSION... /ISSUED 321 PM CDT FRI APR 17 2015/
SHORT TERM...
DRYLINE AT 19Z EXTENDED FROM JUST WEST OF SILVERTON SOUTH TO WHITE
RIVER LAKE AND NEAR LAKE ALAN HENRY. THIS BOUNDARY HAS BEEN FORCED
WEST ALL DAY BY CONVECTIVE OUTFLOWS FARTHER EAST AND RECENT RUNS OF
THE RUC HAVE THE DRYLINE ARRIVING ALONG INTERSTATE 27 BY THIS
EVENING...PERHAPS MUCH SOONER. INSTABILITY-WISE...A NARROW AXIS OF
SBCAPE AROUND 1000 J/KG MAY FULFILL SOME TSTORMS ALONG AND EAST OF
THE DRYLINE THROUGH THE EVENING...BUT VISUAL TRENDS OF TOWERING AND
MODERATE CU SUGGEST DEEPER ASCENT IS LACKING. WATER VAPOR IMAGERY
INDICATE THIS AREA IS BATTLING SUBSIDENCE ALOFT DUE TO AN AXIS OF
PERSISTENT DEEP CONVECTION 60-100 MILES FARTHER EAST. BECAUSE OF
THIS AND LIMITED NWP SUPPORT...POPS HAVE BEEN SCALED BACK TO SLIGHT
CHANCE FOR MOST AREAS OFF THE CAPROCK.
AS THE FOUR CORNERS LOW BEGINS LIFTING NORTHEAST TONIGHT...LOWER
TROPOSPHERIC WINDS WILL VEER MORE WESTERLY ACROSS THE WESTERN HALF
OF THE CWA AND HELP TO NUDGE THE DRYLINE EASTWARD BEFORE DAYBREAK
SAT. MODELS AGREE THE DRYLINE WILL MIX OUT OF OUR EASTERN ZONES BY
MIDDAY AHEAD OF BREEZY SW WINDS...BUT ANY DISRUPTION TO THIS SUCH AS
WE SAW TODAY WITH CONVECTIVE OUTFLOWS COULD SUPPORT A MORE WESTERLY
DRYLINE LOCATION AND NECESSITATE MODIFICATIONS TO OUR DRY FORECAST
FOR SATURDAY. WHEREVER THE DRYLINE ENDS UP...DEEP CONVECTION SHOULD
EASILY UNFOLD BY SAT AFTN UNDER WEAK INHIBITION...STRONGER CYCLONIC
FLOW AND A FAVORABLE MID-LEVEL COLD POCKET OF -20C AT 500MB.
LONG TERM...
COLD FRONT PROGGED TO MOVE THROUGH THE FCST AREA SUNDAY MORNING
WITH ENOUGH COLD ADVECTION TO RESULT IN HIGHS MAINLY UPPER 60S AND
LOWER 70S WHILE ALSO SCOURING LOW LEVEL MOISTURE OUT OF THE FCST
AREA. MAY SEE SOME CONVECTION ATTEMPT TO DEVELOP ON THE HIGH
TERRAIN OF NRN NM/SRN COLO AND BE DRIVEN TO THE SE ON NWLY UPPER
FLOW...BUT WITH DRY LOW LEVELS WOULD EXPECT IT TO HAVE A HARD
TIME GETTING THIS FAR TO THE SE. SITUATION CHANGES SOME MONDAY
WHEN SOUTH AND SE WINDS BEGIN TO BRING MOISTURE BACK INTO THE
AREA. LOOKS LIKE HIGH TERRAIN CONVECTION WILL HAVE A BETTER CHANCE
OF MOVING THROUGH THE PANHANDLE AND INTO NRN PARTS OF THE FCST
AREA.
THE MIDDLE PART OF THE WEEK WILL THEN BE ONE WITH POSSIBILITY OF
WEAKLY-FORCED DIURNAL DRYLINE STORMS WITH LOW LEVEL MOISTURE
INCREASING WITH TIME...CONFLUENT FLOW ALOFT TRANSITIONING TO WEAK
UPPER RIDGING. 20-30 PCT STORM CHANCES TUESDAY THROUGH FRIDAY LOOK
FINE WITH THIS SYNOPTIC SETUP.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 40 70 40 65 / 0 0 10 0
TULIA 48 73 44 67 / 0 0 10 0
PLAINVIEW 49 73 45 68 / 0 0 0 0
LEVELLAND 45 75 46 70 / 0 0 0 0
LUBBOCK 50 76 47 71 / 0 0 0 0
DENVER CITY 44 74 47 71 / 0 0 0 0
BROWNFIELD 45 76 48 72 / 0 0 0 0
CHILDRESS 56 79 51 73 / 20 10 10 0
SPUR 54 79 50 73 / 20 0 0 0
ASPERMONT 57 81 52 77 / 20 10 10 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION...DELAYED
NWS BLACKSBURG VA
1154 PM EDT SUN APR 19 2015
.SYNOPSIS...
LOW PRESSURE OVER WESTERN KENTUCKY WITH A WARM FRONT EXTENDING EAST
AND COLD FRONT TRAILING SOUTHWARD FROM THE LOW WILL LIFT NORTHEAST
TONIGHT INTO MONDAY. A COLD FRONT CROSSES THE REGION ON
MONDAY...THEN HIGH PRESSURE BUILDS IN FOR TUESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 1150 PM EDT SUNDAY...
FLOOD WATCHES REMAIN IN EFFECT TONIGHT.
MESO-SCALE WAVE TRACKING NORTH ALONG THE APPALACHIANS AT
MIDNIGHT...WILL PULL THE BULK OF THE HEAVY RAIN WITH IT. SINCE THE
ALLEGHANY HIGHLANDS AND SOUTHERN SHENANDOAH VALLEY DID NOT HAVE RAIN
ALL DAY AND MODERATE TO HEAVY RAIN HAS ONLY FALLEN FOR A FEW
HOURS...THE FLOOD THREAT IS DIMINISHING QUICKLY. WE WILL CONTINUE
THE FLOOD WATCH FOR THE ROANOKE VALLEY NORTHWARD UNTIL THE RAIN
EXITS THE AREA...POSSIBLY BY 2AM. THE FLOOD WATCH TO THE SOUTH
INTO THE NORTH CAROLINA HIGHLAND WILL EXPIRE AT MIDNIGHT.
PREVIOUS DISCUSSION...
AS OF 333 PM EDT SUNDAY...
FLOOD WATCHES REMAIN IN EFFECT INTO TONIGHT.
A WARM FRONT TO OUR SOUTH WILL LIFT NORTH THIS EVENING AND CROSS THE
FORECAST AREA TONIGHT. DEEPER MOISTURE AND HIGHER PWATS WILL
INCREASE IN THE WARM ADVECTION WITH THE NORTHWARD ADVANCE OF THE
FRONT. THE REGIONAL RADAR IMAGE SHOWED WIDESPREAD CONVECTION ACROSS
THE MID ATLANTIC REGION SOUTHWARD TO THE SOUTHEAST US. THERE ARE
SOME CONCERNS OF STRONG CONVECTION ACROSS GEORGIA THIS AFTERNOON MAY
TAKE SOME OF THE MOISTURE AWAY FROM OUR AREA. OUR LOCAL RNK
WRFARW...HIRESW-ARW...NAM AND GFS WAIT UNTIL AFTER 00Z BEFORE
BRINGING IN HEAVIER CONVECTION THIS EVENING...WHILE HRRR AND ECMWF
ARE A LITTLE FASTER WITH TIMING. THE HRRR AND HIRESW-ARW LIFTS THE
PRECIPITATION NORTHEAST WITH MOST OF RAIN PULLING OUT BY 06-08Z.
USED A BLEND OF HRRR AND NAM FOR POPS...TAPERING POPS BACK AFTER 06Z
TONIGHT INTO MONDAY MORNING.
NOT EXPECTING ANY STRONG THUNDERSTORMS THIS AFTERNOON INTO TONIGHT
WITH CLOUD COVER HINDERING INSTABILITIES. HOWEVER...THE LOW LEVEL
JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL RESULT IN
STRONG UPSLOPE AND ISENTROPIC LIFT. THE STRONG WINDS THROUGH A
DEEP LAYER WILL PROVIDE LARGE HELICITY VALUES LATE THIS AFTERNOON
INTO THIS EVENING. THE DAY ONE CONVECTIVE OUTLOOK (SWODY1) PLACED
A MARGINAL (5 PERCENT CHANCE OF WIND) ACROSS SOUTHWEST PORTION OF
CWA. PLAYED LOW TEMPERATURES CLOSE TO ADJMAV WITH READINGS FROM
THE UPPER 40S IN THE NORTHWEST MOUNTAINS TO AROUND 60 DEGREES IN
THE PIEDMONT.
A WARM...MOIST AND UNSTABLE AIRMASS EXPECTED MONDAY. THE ATMOSPHERE
WILL DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT WITH SHOWERS
AND THUNDERSTORMS DEVELOPING MONDAY. INITIALLY CUT BACK POPS CLOSER
TO NAM FOR MONDAY MORNING...THEN INCREASED TO LIKELY BY MONDAY
AFTERNOON. SPC CONTINUES OUR SLIGHT RISK FOR MONDAY ACROSS MOST OF
OUR CWA. THIS IS SUPPORTED BY THE DYNAMIC ENVIRONMENT WITH HEALTHY
SHEAR AND DECENT CAPES AROUND 2K. IT WILL ALSO BE QUITE BREEZY WITH
EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER.
THE FRONT SHOULD BE CLEARING MONDAY NIGHT. HIGH TEMPERATURES MONDAY
WILL RANGE FROM THE MID 60S IN THE MOUNTAINS TO THE LOWER 80S IN THE
PIEDMONT.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 345 PM EDT SUNDAY...
TAIL END OF COLD FRONT AND ASSOCIATED CONVECTION WILL BE EXITING
THE AREA JUST AFT 00Z. HOWEVER...A BROAD UPPER TROUGH...ALMOST
WINTERLIKE PATTERN CONTINUES TO EVOLVE AND DEEPEN ACROSS THE
GREAT LAKES WITH NUMEROUS SPOKES OF PVA/SHORT WAVES REMAINING
UPSTREAM. THIS LEAVES THE REGION...ESPECIALLY THE MOUNTAINS...WITH
A VERY UNSETTLED PATTERN. AT A MINIMUM...EXPECT VARIABLE
CLOUDINESS. TIMING OF EMBEDDED DISTURBANCES WILL BE THE KEY TO THE
TIMES FOR THE BETTER CHANCES OF SHOWERS. FOR SEVERAL DAYS...THE
GFS HAS INSISTED ON A SIGNIFICANT DISTURBANCE MOVING THROUGH THE
REGION WED WITH WIDESPREAD -SHRA AS A RESULT. THE OTHER MODELS
REMAIN LACKLUSTER WITH THIS FEATURE...BUT DO SUGGEST AT LEAST SOME
SMALL CHANCE WITHIN THIS TIME FRAME. GIVEN THE UNSETTLED NATURE OF
THE PATTERN WITH UPSLOPE FLOW AND VERY DIFFICULT TO TIME UPPER
DISTURBANCES...CANNOT REALLY DROP POPS AT ANY TIME. BEST FOCUS
THROUGH THE PERIOD WILL REMAIN WEST OF THE BLUE RIDGE...AND
ESPECIALLY ACROSS THE MOUNTAINS OF WV/FAR SW VA. IN
ADDITION...ENOUGH INSTABILITY SUGGESTED WITH COLD AIR ALOFT...TO
INTRODUCE ISOLD TSRA WITH THE WED DISTURBANCE AS WELL.
850MB TEMPS DROP TO NEAR 0C ACROSS THE NORTHERN PART OF THE
FORECAST AREA BY WED...BUT THE BETTER COLD ADVECTION COMES IN THE
EXTENDED PERIOD BEHIND THE WED DISTURBANCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...
BROAD UPPER TROUGH REMAINS IN PLACE AND DOMINATES THE EXTENDED
FORECAST...GRADUALLY SHIFTING FURTHER ESE LATE IN THE PERIOD.
THIS KEEPS THE REGION IN AN UNSTABLE/UNSETTLED NORTHWEST FLOW WITH
NUMEROUS EMBEDDED SHORT WAVES. MODELS VARY CONSIDERABLY AS TO THE
TIMING AND PLACEMENT OF THESE DISTURBANCES...BUT ENOUGH AGREEMENT
THAT POPS CANNOT BE DROPPED REALLY AT ANY TIME THE OVERALL TREND
IS TO PUSH THE BETTER MOISTURE FURTHER SOUTH OF THE REGION AS THE
WEEK PROGRESSES AND 850MB TEMPS DROP BELOW 0C IN THE NORTHERN
COUNTIES. THE ENTIRE PERIOD SHOULD FEATURE BELOW NORMAL
TEMPERATURES WITH LOW CHC POPS...HIGHEST ACROSS THE MOUNTAINS AND
TOWARD THE SOUTHERN COUNTIES...WITH THE NORTHERN PIEDMONT THE
DRIEST. ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL THROUGHOUT THE
PERIOD...NO REAL CLEAR CONCERN AT THIS POINT FOR FROST/FREEZE
BECAUSE OF CYCLONIC FLOW AND CLOUDS.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
AS OF 742 PM EDT SUNDAY...
A STRONG SOUTHEAST LOW LEVEL JET WILL CONTINUE TO BRING WIND GUSTS
UP TO 30KTS ALONG WITH 1-2 HOURS OF HEAVY RAIN ACROSS THE FORECAST
AREA THIS EVENING. LOW-END MVFR RESTRICTIONS WILL REMAIN IN PLACE
THROUGH MIDNIGHT...WITH VISIBILITIES IMPROVING AS RAIN EXITS. VFR
CONDITIONS HIGHLY LIKELY MONDAY MORNING...THEN CONVECTION WITH THE
COLD FRONT EXPECTED IN THE AFTERNOON. THIS CONVECTION WILL EXIT
THE MOUNTAINS BY 18Z AND THE PIEDMONT BY 22Z MONDAY.
MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE
TAF PERIOD.
EXTENDED AVIATION...
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH UNTIL 6 AM EDT MONDAY FOR VAZ018>020-022>024-
033>035.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...KK/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/KK/RCS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
756 PM EDT SUN APR 19 2015
.SYNOPSIS...
LOW PRESSURE OVER WESTERN KENTUCKY WITH A WARM FRONT EXTENDING EAST
AND COLD FRONT TRAILING SOUTHWARD FROM THE LOW WILL LIFT NORTHEAST
TONIGHT INTO MONDAY. A COLD FRONT CROSSES THE REGION ON
MONDAY...THEN HIGH PRESSURE BUILDS IN FOR TUESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 730 PM EDT SUNDAY...
FLOOD WATCHES REMAIN IN EFFECT INTO TONIGHT.
LAST BAND OF HEAVY RAIN MOVING ACROSS THE AREA THIS EVENING. VERY
HEAVY RAIN IS EXPECTED...ESPECIALLY ALONG THE BLUE RIDGE...WITH
WIND GUSTS UP TO 40 MPH. RAINFALL AMOUNTS OF 2 TO 4 INCHES HAVE
BEEN REPORTED FROM WATAUGA COUNTY NC TO PATRICK COUNTY VA. CREEKS
AND STREAMS ARE COMING OUT OF THEIR BANKS...THEREFORE WILL
CONTINUE WITH THE FLOOD WATCH UNTIL THE THREAT IS OVER...POSSIBLY
BY MIDNIGHT.
PREVIOUS DISCUSSION...
AS OF 333 PM EDT SUNDAY...
FLOOD WATCHES REMAIN IN EFFECT INTO TONIGHT.
A WARM FRONT TO OUR SOUTH WILL LIFT NORTH THIS EVENING AND CROSS THE
FORECAST AREA TONIGHT. DEEPER MOISTURE AND HIGHER PWATS WILL
INCREASE IN THE WARM ADVECTION WITH THE NORTHWARD ADVANCE OF THE
FRONT. THE REGIONAL RADAR IMAGE SHOWED WIDESPREAD CONVECTION ACROSS
THE MID ATLANTIC REGION SOUTHWARD TO THE SOUTHEAST US. THERE ARE
SOME CONCERNS OF STRONG CONVECTION ACROSS GEORGIA THIS AFTERNOON MAY
TAKE SOME OF THE MOISTURE AWAY FROM OUR AREA. OUR LOCAL RNK
WRFARW...HIRESW-ARW...NAM AND GFS WAIT UNTIL AFTER 00Z BEFORE
BRINGING IN HEAVIER CONVECTION THIS EVENING...WHILE HRRR AND ECMWF
ARE A LITTLE FASTER WITH TIMING. THE HRRR AND HIRESW-ARW LIFTS THE
PRECIPITATION NORTHEAST WITH MOST OF RAIN PULLING OUT BY 06-08Z.
USED A BLEND OF HRRR AND NAM FOR POPS...TAPERING POPS BACK AFTER 06Z
TONIGHT INTO MONDAY MORNING.
NOT EXPECTING ANY STRONG THUNDERSTORMS THIS AFTERNOON INTO TONIGHT
WITH CLOUD COVER HINDERING INSTABILITIES. HOWEVER...THE LOW LEVEL
JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL RESULT IN
STRONG UPSLOPE AND ISENTROPIC LIFT. THE STRONG WINDS THROUGH A
DEEP LAYER WILL PROVIDE LARGE HELICITY VALUES LATE THIS AFTERNOON
INTO THIS EVENING. THE DAY ONE CONVECTIVE OUTLOOK (SWODY1) PLACED
A MARGINAL (5 PERCENT CHANCE OF WIND) ACROSS SOUTHWEST PORTION OF
CWA. PLAYED LOW TEMPERATURES CLOSE TO ADJMAV WITH READINGS FROM
THE UPPER 40S IN THE NORTHWEST MOUNTAINS TO AROUND 60 DEGREES IN
THE PIEDMONT.
A WARM...MOIST AND UNSTABLE AIRMASS EXPECTED MONDAY. THE ATMOSPHERE
WILL DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT WITH SHOWERS
AND THUNDERSTORMS DEVELOPING MONDAY. INITIALLY CUT BACK POPS CLOSER
TO NAM FOR MONDAY MORNING...THEN INCREASED TO LIKELY BY MONDAY
AFTERNOON. SPC CONTINUES OUR SLIGHT RISK FOR MONDAY ACROSS MOST OF
OUR CWA. THIS IS SUPPORTED BY THE DYNAMIC ENVIRONMENT WITH HEALTHY
SHEAR AND DECENT CAPES AROUND 2K. IT WILL ALSO BE QUITE BREEZY WITH
EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER.
THE FRONT SHOULD BE CLEARING MONDAY NIGHT. HIGH TEMPERATURES MONDAY
WILL RANGE FROM THE MID 60S IN THE MOUNTAINS TO THE LOWER 80S IN THE
PIEDMONT.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 345 PM EDT SUNDAY...
TAIL END OF COLD FRONT AND ASSOCIATED CONVECTION WILL BE EXITING
THE AREA JUST AFT 00Z. HOWEVER...A BROAD UPPER TROUGH...ALMOST
WINTERLIKE PATTERN CONTINUES TO EVOLVE AND DEEPEN ACROSS THE
GREAT LAKES WITH NUMEROUS SPOKES OF PVA/SHORT WAVES REMAINING
UPSTREAM. THIS LEAVES THE REGION...ESPECIALLY THE MOUNTAINS...WITH
A VERY UNSETTLED PATTERN. AT A MINIMUM...EXPECT VARIABLE
CLOUDINESS. TIMING OF EMBEDDED DISTURBANCES WILL BE THE KEY TO THE
TIMES FOR THE BETTER CHANCES OF SHOWERS. FOR SEVERAL DAYS...THE
GFS HAS INSISTED ON A SIGNIFICANT DISTURBANCE MOVING THROUGH THE
REGION WED WITH WIDESPREAD -SHRA AS A RESULT. THE OTHER MODELS
REMAIN LACKLUSTER WITH THIS FEATURE...BUT DO SUGGEST AT LEAST SOME
SMALL CHANCE WITHIN THIS TIME FRAME. GIVEN THE UNSETTLED NATURE OF
THE PATTERN WITH UPSLOPE FLOW AND VERY DIFFICULT TO TIME UPPER
DISTURBANCES...CANNOT REALLY DROP POPS AT ANY TIME. BEST FOCUS
THROUGH THE PERIOD WILL REMAIN WEST OF THE BLUE RIDGE...AND
ESPECIALLY ACROSS THE MOUNTAINS OF WV/FAR SW VA. IN
ADDITION...ENOUGH INSTABILITY SUGGESTED WITH COLD AIR ALOFT...TO
INTRODUCE ISOLD TSRA WITH THE WED DISTURBANCE AS WELL.
850MB TEMPS DROP TO NEAR 0C ACROSS THE NORTHERN PART OF THE
FORECAST AREA BY WED...BUT THE BETTER COLD ADVECTION COMES IN THE
EXTENDED PERIOD BEHIND THE WED DISTURBANCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...
BROAD UPPER TROUGH REMAINS IN PLACE AND DOMINATES THE EXTENDED
FORECAST...GRADUALLY SHIFTING FURTHER ESE LATE IN THE PERIOD.
THIS KEEPS THE REGION IN AN UNSTABLE/UNSETTLED NORTHWEST FLOW WITH
NUMEROUS EMBEDDED SHORT WAVES. MODELS VARY CONSIDERABLY AS TO THE
TIMING AND PLACEMENT OF THESE DISTURBANCES...BUT ENOUGH AGREEMENT
THAT POPS CANNOT BE DROPPED REALLY AT ANY TIME THE OVERALL TREND
IS TO PUSH THE BETTER MOISTURE FURTHER SOUTH OF THE REGION AS THE
WEEK PROGRESSES AND 850MB TEMPS DROP BELOW 0C IN THE NORTHERN
COUNTIES. THE ENTIRE PERIOD SHOULD FEATURE BELOW NORMAL
TEMPERATURES WITH LOW CHC POPS...HIGHEST ACROSS THE MOUNTAINS AND
TOWARD THE SOUTHERN COUNTIES...WITH THE NORTHERN PIEDMONT THE
DRIEST. ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL THROUGHOUT THE
PERIOD...NO REAL CLEAR CONCERN AT THIS POINT FOR FROST/FREEZE
BECAUSE OF CYCLONIC FLOW AND CLOUDS.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 742 PM EDT SUNDAY...
A STRONG SOUTHEAST LOW LEVEL JET WILL CONTINUE TO BRING WIND GUSTS
UP TO 30KTS ALONG WITH 1-2 HOURS OF HEAVY RAIN ACROSS THE FORECAST
AREA THIS EVENING. LOW-END MVFR RESTRICTIONS WILL REMAIN IN PLACE
THROUGH MIDNIGHT...WITH VISIBILITIES IMPROVING AS RAIN EXITS. VFR
CONDITIONS HIGHLY LIKELY MONDAY MORNING...THEN CONVECTION WITH THE
COLD FRONT EXPECTED IN THE AFTERNOON. THIS CONVECTION WILL EXIT
THE MOUNTAINS BY 18Z AND THE PIEDMONT BY 22Z MONDAY.
MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE
TAF PERIOD.
EXTENDED AVIATION...
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.HYDROLOGY...
AS OF 330 PM EDT SUNDAY...
HAVE EXPANDED THE FLOOD WATCH FOR THE ALLEGHANY HIGHLANDS OF
VIRGINIA.
A DEEP LAYER FROM THE SURFACE THROUGH MID LEVELS OF THE
ATMOSPHERE OF SOUTHEAST WINDS...WILL BE INCREASING TO AROUND 50
KNOTS LATER THIS AFTERNOON AND EVENING. PRECIPITABLE WATER VALUES
JUST ABOVE 1.5 INCHES WILL BE ADVECTED INTO THE FORECAST AREA. THE
STRONGEST LIFT AND HIGHEST RAINFALL AMOUNTS WILL BE FROM 18Z/2PM
THROUGH 06Z/2AM SO HAVE ADDED HEAVY RAIN TO THE FORECAST ALONG THE
BLUE RIDGE FOR THIS TIME FRAME.
TOTAL RAINFALL AMOUNTS WILL RANGE FROM 1 TO 3 INCHES THROUGH
12Z/8AM MONDAY. FLASH FLOOD GUIDANCE VALUES WERE ROUGHLY 1.5 TO
2.5 INCHES FOR 3 HOURS. SO THIS AMOUNT OF RAINFALL HAS THE
POTENTIAL TO PRODUCE FLOODING ON SMALL STREAMS AND CREEKS.
PROBABILISTIC GUIDANCE FOR MAINSTEM RIVERS SUGGESTS A SMALL
POSSIBILITY FOR MINOR FLOODING ALONG THE DAN RIVER AND NEW RIVER.
HOWEVER...THE IS HIGHLY DEPENDENT ON THE AMOUNT OF RAINFALL
THROUGH MONDAY MORNING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH UNTIL 6 AM EDT MONDAY FOR VAZ018>020-022>024-
033>035.
FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ009-012>017-032.
NC...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ001>003-018>020.
WV...NONE.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...KK/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/KK/RCS
HYDROLOGY...KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
401 PM EDT SAT APR 18 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE OVER OUR AREA TODAY WILL MOVE EAST ALLOWING
A MOISTURE EASTERLY FLOW TO DEVELOP TONIGHT. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN...HEAVY AT
TIMES...SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE
REGION WITH A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON
MONDAY. DRY AND COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF
NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 300 PM EDT SATURDAY
WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.
ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.
PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.
CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...
HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...
MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
AS OF 120 PM EDT SATURDAY...
VFR CONDITIONS WERE NOTED AT ALL THE TAF SITES EARLY THIS
AFTERNOON...BUT FLYING CONDITIONS ARE FORECAST TO DETERIORATE
DURING THE OVERNIGHT HOURS/EARLY MORNING SUNDAY.
FOR THE REMINDER OF TODAY...WEAK CONVERGENCE AND UPSLOPE MAY
GENERATE ISOLD SHWRS OR TSTORMS THIS AFTERNOON...ESPECIALLY NEAR
BLUE RIDGE ALONG OR SOUTH OF VA/NC BORDER...BUT PROBABILITY IS TOO
LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.
MODELS HAVE BEEN CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS
TO LOWER TO MVFR AFTER 08Z. HIGHEST CONFIDENCE IN MVFR CEILINGS
IS AT KBCB AFTER 08Z/2AM.
A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER
MIDNIGHT WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY
SUNDAY AND CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN
PLACE ALONG AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE
NOT EXPECTED TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL
CREATE POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA
WILL BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL
WIND SHEAR.
CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING
THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT
MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT.
WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND
FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING
AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION MOVES ARRIVES.
EXTENDED AVIATION...
A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.
THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.
.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...
ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH FROM LATE TONIGHT THROUGH SUNDAY EVENING FOR
VAZ015>017-032.
NC...FLOOD WATCH FROM LATE TONIGHT THROUGH SUNDAY EVENING FOR
NCZ001>003-018>020.
WV...NONE.
&&
$$
SYNOPSIS...PH
NEAR TERM...PH
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/PH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
154 AM EDT SAT APR 18 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND SATURDAY BRINGING
DRY AND WARM WEATHER FOR THE START OF THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND
COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1012 PM EDT FRIDAY...
ISOLD SHOWERS HAVE DISSIPATED AND SEE NO REASON FOR ANY NEW ONES
TO FIRE UP OVERNIGHT...OTHER THAN ONE OR TWO ACROSS NORTHERN NC
GIVEN MUCAPE VALUES STILL AROUND 300-500 J/KG. ALSO KEEPING AN EYE
ON THE NORTHERN EDGE OF AREA OF SHOWERS INTO SW NC...WHICH IS
AHEAD OF A SHORT WAVE NEAR CHATTANOOGA...AS SOMETHING COULD SNEAK
INTO OUR NW NC MTNS AFTER MIDNIGHT...BUT MOST GUIDANCE AGREES
THIS WILL STAY JUST TO OUR SOUTH. LEFT SLIGHT CHC POP ACROSS
SOUTHERN EDGE OF FCST AREA THROUGH MUCH OF THE NIGHT...BUT REMOVED
MENTION EVERYWHERE ELSE. TRENDS LOOK BETTER FOR MORE CLEARING FROM
WEST LATE...AND THUS POSSIBILITY OF SOME PATCHY VALLEY FOG WITH
WET GROUND SO ADDED THAT AS WELL...MAINLY TO MTN VALLEYS.
OVERNIGHT TEMPS LOOK ON TRACK AT THIS POINT.
PREV DISC AS OF 635 PM EDT FRIDAY...
UPDATE TO REFLECT CURRENT MAINLY ISOLD COVERAGE OF
SHOWERS FROM FOOTHILLS INTO SOUTHSIDE VA. INCLUDED A COUPLE HOURS
OF CHC POPS ACROSS SOUTHSIDE THROUGH EARLY EVENING WITH CLUSTER
OF SHOWERS THERE...AND SO FAR NOT SEEING ANY SIGNS OF EVEN
INTERCLOUD LIGHTNING WITH CELLS NEAR MTV AND DAN...BUT KEEPING
ISOLD THUNDER IN FCST GIVEN SBCAPES OF 500-800 J/KG....AND SOME
ISOLD LTG IN CELLS JUST NORTHEAST OF BUCKINGHAM COUNTY. ALL THIS
ACTIVITY SHOULD SLOWLY DIMINISH AS IT DRIFTS SOUTHEASTWARD INTO
FAR NORTHERN NC BY 8 OR 9PM...AND RECENT HRRR RUNS SEEM TO BE
DOING A BETTER JOB CAPTURING THE SPARSITY OF THE SHALLOW
CONVECTION AND WEAKENING INTO THE EVENING HOURS WITH LOSS OF
HEATING.
SOME OF THE MORE WIDESPREAD LIGHT RAIN OVER FAR SW NC AND UPSTATE
SC WILL SLIDE TO THE NORTHEAST IN ADVANCE OF WEAK SHORT WAVE
HEADING EAST OUT OF TN...BUT PREVIOUS THINKING THAT IT WILL REMAIN
SOUTH OF THE FCST AREA STILL LOOKS ON TRACK. WE DO KEEP A
LINGERING SLIGHT CHC POP ACROSS NW NC MTNS UNTIL A LITTLE AFTER
MIDNIGHT JUST IN CASE...BUT THEN DROP ALL POPS TOWARD MORNING.
PREVIOUS DISCUSSION AS OF 235 PM EDT MONDAY...
AT THE SFC...HIGH PRESSURE WILL SLOWLY NOSE SOUTH INTO THE
EASTERN OHIO VALLEY BRINGING A LIGHT NORTH WIND. A SHALLOW LAYER
OF MOISTURE NEAR THE SURFACE WILL REMAIN...WHICH WILL RESULT IN
POCKETS OF FOG...ESPECIALLY WHERE CLOUDS ARE ABSENT TO THE NORTH.
LEANED TOWARD THE WARMER GUIDANCE VALUES WITH CLOUDS.
FOR SATURDAY...HEIGHTS BUILD IN ADVANCE OF A DEEP UPPER LEVEL TROF
IN THE WEST AND TEMPS SHOULD AGAIN WARM WELL INTO THE 70S AND THE
80S IN THE EAST.
A WEAK LOW LEVEL EAST FLOW COMBINED WITH A NOSE OF HIGHER THETA-E
AIR IN NW NC INTO FAR SW VA MAY SPARK ISOLATED SHOWERS/STORMS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...
FOCUS THROUGH THIS PERIOD REMAINS ON A STRONG NEGATIVELY TILTED
UPPER TROUGH PROGGED TO LIFT RAPIDLY NORTHEAST ACROSS THE REGION
SUNDAY INTO EARLY MONDAY. MEANWHILE...ANTECEDENT HIGH PRESSURE
WILL MOVE OFF THE MID-ATLANTIC COAST INTO A NEAR CLASSIC WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT INDUCED RAINFALL INTO THE
WEDGE AIR MASS WILL ENHANCE/INTENSIFY THE WEDGE SUNDAY.
RAINFALL/QPF WILL BE THE MAIN CONCERN AS THE WEDGE KEEPS A VERY
STABLE/COOL AIR MASS IS PLACE. MOIST SOUTHEAST...UPSLOPE FLOW
ALONG THE BLUE RIDGE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS
WATAUGA NORTHEAST TOWARD FLOYD. AS NOTED YESTERDAY...HOWEVER...THE
SYSTEM WILL REMAIN HIGHLY PROGRESSIVE...LIMITING THE PERIOD OF
HEAVIER RAINFALL TO 12 HOURS OR LESS. WPC HAS PARTS OF THE NC/VA
SOUTHERN VA PIEDMONT OUTLOOKED FOR EXCESSIVE RAINFALL. THE MAIN
CONCERN WITHIN THIS AREA WOULD BE WATAUGA THROUGH
ASHE/WILKES...WITH LESS CONCERN TOWARD THE DANVILLE AREA WHERE
ANTECEDENT CONDITIONS ARE RELATIVELY DRY. IN ADDITION...THE
CONVECTIVE THREAT THROUGH THE HEAVIER RAIN PERIOD AS NOTED ABOVE
IS MINIMAL TO NONE...WHICH SHOULD FURTHER REDUCE THE FLASH FLOOD
THREAT. WILL RE-EVALUATE AGAIN TOMORROW...BUT AT THIS POINT NO
NEED FOR A FLOOD/FLASH FLOOD WATCH. ONE MAY EVENTUALLY BE NEEDED
FOR A SMALL AREA INCLUDING THE NW NC MOUNTAINS AND THE ADJACENT
FOOTHILLS. WENT WELL BELOW GUIDANCE ON MAX TEMPS IN THE WEDGE
SUNDAY...BUT AT OR ABOVE GUIDANCE ON MONDAY IN THE WARM SECTOR.
MAX TEMPS MONDAY WILL BE A GOOD 20 DEGREES WARMER IN MOST AREAS
THAN ON SUNDAY.
MONDAY IS A DIFFERENT STORY. A SIGNIFICANT WARM SECTOR WILL SURGE
NORTHWARD INTO THE REGION MONDAY AFTERNOON BEHIND THE DEPARTING
UPPER TROUGH AND AN APPROACHING STRONG COLD FRONT ASSOCIATED WITH
A DEEPENING BROAD UPPER TROUGH ACROSS THE GREAT LAKES. SEVERAL OF
THE MODELS CONTINUE TO ADVERTISE GOOD POTENTIAL FOR STRONG
THUNDERSTORMS MONDAY AFTERNOON...WITH SIGNIFICANT SVR PARAMETER
NEAR 20000 ACROSS THE PIEDMONT...CAPES NEARING 2000 J/KG WITH AT
LEAST 20-30KTS OF 0-2KM LOW-LEVEL SHEAR AND LIS NEAR -4C. SPC DAY
4 OUTLOOK SUGGESTS THAT DAMAGING WINDS WOULD BE THE MAIN CONCERN
WITH ANY CONVECTION...MOST LIKELY LINEAR ORIENTED...THAT DEVELOPS
ALONG/IN ADVANCE OF THE COLD FRONT MONDAY AFTERNOON/EVENING. THIS
ACTIVITY QUICKLY MOVES EAST OF THE REGION MON AFTERNOON.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...
A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.
BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM EDT SATURDAY...
STARTING THE TAF PERIOD WITH WEAK HIGH PRESSURE AND LIGHT WINDS
OVER THE MID ATLANTIC REGION. SOME FOG HAD DEVELOPED IN THE
VALLEYS IN AREAS WHERE THE HIGH CLOUDS HAD CLEARED OUT. ISOLATED
THUNDERSTORMS EAST OF LYNCHBURG WILL NOT IMPACT TAF SITES.
LOCATIONS THAT HAVE SOME CLEARING EARLY THIS MORNING MAY HAVE FOG
DEVELOPMENT...ESPECIALLY IN THE VALLEYS WEST OF THE BLUE RIDGE.
HIGHEST CONFIDENCE OF FOG FORMING IS AT KBCB WERE THE DEW POINT
DEPRESSION WAS ALREADY SMALL. FOG WILL BRING THE VISIBILITY DOWN
TO IFR VALUES...POSSIBLY LIFR AT KLWB AFTER 10Z/6AM.
ANY FOG AND LOW STRATUS DISSIPATES BY 13Z OR SO...FOR WIDESPREAD
VFR CONDITIONS FOR THE DAY SATURDAY...WITH LIGHT EAST TO NORTHEAST
WINDS AS SFC HIGH PRESSURE REMAINS TO THE NORTH AND WEAK SFC
TROUGH WILL LINGER ACROSS NORTH CAROLINA. THIS MAY RESULT IN
ENOUGH WEAK CONVERGENCE AND UPSLOPE TO KICK OFF A FEW ISOLD SHWRS
OR TSTORMS BY AFTERNOON...ESPECIALLY NEAR BLUE RIDGE ALONG OR
SOUTH OF VA/NC BORDER...BUT VERY UNLIKELY ANY ONE SHOWER OR STORM
WILL IMPACT ANY AIRPORTS.
EXTENDED AVIATION...
A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.
THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PH
NEAR TERM...JH/PH/SK
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/SK
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1128 AM CDT SAT APR 18 2015
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.UPDATE...
ISSUED AT 407 AM CDT SAT APR 18 2015
AFTER FURTHER COORDINATION WITH ARX AND THE DNR...WILL ISSUE A RED
FLAG WARNING FOR WOOD COUNTY. THE COMBO OF HUMIDITIES FALLING NEAR
20 PCT THIS AFTERNOON...MAX TEMPS IN THE 60S...WIND SPEEDS OF 10
TO 20 MPH...AND DRY FUELS WILL LEAD TO A CRITICAL FIRE WEATHER DAY
THERE. THIS RED FLAG WARNING WILL TARGET THE PINE COUNTRY OF
CENTRAL WISCONSIN.
ADDITIONALLY...THE COLD FRONT HAS JUST PASSED OVER GREEN BAY.
WINDS HAVE SHIFTED TO THE NORTH AND ARE GUSTING TO 22 KNOTS AT THE
GRB AIRPORT. SOME GUSTS UP TO 25 KNOTS OVER THE BAY ARE ALSO OCCURRING.
&&
.SHORT TERM...TODAY...TONIGHT...AND SUNDAY
ISSUED AT 330 AM CDT SAT APR 18 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A FAIRLY
POTENT COLD FRONT DROPPING SOUTH OVER FAR N-C WISCONSIN AND THE
CENTRAL UPPER PENINSULA. NORTH WINDS BEHIND THE FRONT COMBINED WITH
IMPRESSIVE PRESSURE RISES ARE CONTRIBUTING TO WIND GUSTS OVER 30 KTS
OVER LAKE SUPERIOR. AS THE FRONT MOVES ACROSS NORTHERN WISCONSIN
EARLY THIS MORNING...EXPECT NORTH WINDS TO STRENGTHEN AND BECOME
GUSTY FOR PERIOD. ELSEWHERE...UPPER LEVEL LOW PRESSURE CONTINUES TO
SPIN OVER THE CENTRAL ROCKIES AND PRODUCE SHOWERS AND THUNDERSTORMS
ACROSS THE CENTRAL GREAT PLAINS. FORECAST CONCERNS INCLUDE FIRE
WEATHER PARAMETERS TODAY...AND PRECIP CHANCES ON SUNDAY.
TODAY...THE DRY COLD FRONT WILL DROP SOUTH ACROSS THE REST OF
NORTHERN WISCONSIN EARLY THIS MORNING AND CENTRAL WISCONSIN BY
MID-MORNING. BEHIND THE FRONT...THE MODELS ARE STILL DEPICTING VERY
DRY AIR TO MOVE INTO NORTH-CENTRAL TO EAST-CENTRAL WISCONSIN TODAY.
THOUGH NORTHEAST WINDS OFF LAKE MICHIGAN WILL HELP MODERATE THE DRY
AIR OVER EASTERN WISCONSIN...MODEST WIND SPEEDS SHOULD BE ABLE TO TAP INTO
THIS VERY DRY AIR JUST ABOVE THE INVERSION...AROUND 900MB. SO WAS
AGGRESSIVE IN DROPPING HUMIDITIES TODAY...WHICH SHOULD FALL INTO THE
TEENS OVER N-C WISCONSIN AND TO AROUND 25 PCT OVER CENTRAL
WISCONSIN. EAST WINDS WILL ALSO BE APPROACHING CRITICALLY SUSTAINED
SPEEDS OVER CENTRAL WISCONSIN THIS AFTERNOON. STILL WAITING FOR A
FINAL DECISION FROM THE DNR CONCERNING A RED FLAG WARNING...WHICH SHOULD
HAVE BY 5 AM. OTHERWISE...WILL SEE A SUNNY AND COOLER DAY. HIGHS
IN THE LOW TO MID 60S AWAY FROM LAKE MICHIGAN.
TONIGHT...CLOUDS WILL BE ON THE INCREASE AS THE CENTRAL ROCKIES
UPPER LOW MOVES ACROSS THE CENTRAL PLAINS...WHILE A NORTHERN STREAM
WAVE DIGS OVER THE NORTHERN PLAINS. AS CLOUDS THICKEN AND
LOWER...WINDS BELOW 900MB WILL REMAIN OUT OF THE SOUTHEAST AND
CONTINUE TO ADVECT VERY DRY AIR OVER THE REGION. THIS DRY AIR WILL
HAVE TO BE OVERCOME...AND THIS MAY NOT OCCUR UNTIL LATE IN THE NIGHT
OVER THE WEST. WILL MODIFY PRECIP CHANCES SLIGHTLY TO REFLECT THIS.
LOWS RANGING FROM THE MID 30S NORTH TO THE MID 40S SOUTHWEST.
SUNDAY...MID-LEVEL HEIGHT FALLS WILL CONTINUE TO ADVANCE INTO THE
WESTERN GREAT LAKES. ONE AREA OF LOW PRESSURE WILL MOVE INTO
WESTERN WISCONSIN DURING THE AFTERNOON...WHILE A SOUTHERN STREAM LOW
SWINGS NE TOWARDS THE SOUTHERN TIP OF LAKE MICHIGAN. FORCING WILL
IMPROVE THROUGH THE DAY AHEAD OF THESE FEATURES...THOUGH THE LEAD BAND OF
LIGHT RAIN MAY DECAY DURING THE MORNING AS A RESULT OF THE DRY LOW
LEVEL FLOW. THEN A SECOND ROUND OF PRECIP MAY TRY TO MOVE INTO THE
AREA WITH THE APPROACHING LOW PRESSURE SYSTEMS. TEMPS ARE DIFFICULT
BECAUSE OF THE PRECIP POTENTIAL...AMPLE CLOUD COVER...AND EAST
WINDS. HAVE DROPPED TEMPS SOME SINCE TEMPS DO NOT TYPICALLY RISE
WELL WHEN THERE IS CLOUD COVER AND EAST WINDS. PRECIP WILL ALSO
LIKELY HOLD TEMPS BACK OVER CENTRAL AND NORTH-CENTRAL WISCONSIN. SO
WENT WITH HIGHS RANGING FROM THE MID 50S NORTH TO LOW 60S SOUTH.
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY
ISSUED AT 330 AM CDT SAT APR 18 2015
500MB TROUGH WILL EVOLVE INTO A CLOSED UPPER LOW OVER THE WESTERN
GREAT LAKES REGION EARLY NEXT WEEK...THEN MEANDER ACROSS EASTERN
CANADA AND THE GREAT LAKES REGION THROUGH THE END OF NEXT WEEK.
THIS WILL LEAD TO COOL AND UNSETTLED CONDITIONS...ALONG WITH A
CHANCE OF SNOW LATE AT NIGHT AND EARLY MORNING HOURS.
RAINFALL TOTALS STILL PROBLEMATIC SUNDAY NIGHT AS TWO SEPARATE
SYSTEMS WILL BRING RAIN TO THE AREA. NORTHERN STREAM SYSTEM WILL
BRING RAIN TO THE WESTERN HALF OF THE STATE...MEANWHILE A FAIRLY
POTENT LOW PRESSURE SYSTEM WILL MOVE NORTHEAST INTO THE GREAT
LAKES REGION SUNDAY NIGHT. STILL A LOT OF QUESTIONS ON TRACK OF
SYSTEM DUE TO CLOSING UPPER LOW NORTHWEST OF THE STATE. MODEL QPF
WOULD SUGGEST THAT MUCH NEEDED RAIN WOULD FALL ACROSS THE REGION.
MAIN QUESTION IS WHERE AXIS OF HEAVIER RAIN WOULD FALL. MODEL
RUN TO RUN CONTINUITY HAS NOT BEEN CONSISTENT...THUS LOW CONFIDENCE
IN THE RAINFALL AMOUNT FORECAST. MONDAY IS NOT MUCH CLEARER AS SOME
OF THE MODELS BRING DRY SLOT ACROSS THE AREA WITH A SIGNIFICANT DOWNWARD
TREND IN RAINFALL AMOUNTS. THE ECMWF/CANADIAN DO NOT SHARE THIS TREND
WITH THE WRF/GFS...THUS WILL KEEP SCATTERED DEPICTION/WORDING IN
THE FORECAST.
AS UPPER LOW CLOSES MONDAY NIGHT THROUGH WEDNESDAY...COOL CYCLONIC FLOW
AND WEAK DISTURBANCES MOVING THROUGH THE MEAN FLOW WILL BRING
CHANCES OF RAIN AND SNOW SHOWERS DEPENDING ON LOCATION AND TIMING
OF THE DAY. AT SOME POINT...THERE COULD BE A MINOR ACCUMULATION OF
SNOW ACROSS THE NORTH. SOME MODERATION IN TEMPERATURES IS EXPECTED BY
THE END OF THE WEEK AS THE UPPER LOW GRADUALLY SHIFTS EAST OF THE AREA.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1102 AM CDT SAT APR 18 2015
VFR CONDITIONS EXPECTED THROUGH THIS AFTERNOON. GUSTY ENE WINDS TO
CONTINUE BEFORE DIMINISHING THIS EVENING...WITH THE GUSTIEST WINDS
IN EASTERN TAF SITES.
DRY CONDITIONS WILL HOLD THROUGH THE NIGHT...WITH INCREASING VFR
CLOUD COVER FROM SW TO NE THROUGH THE NIGHT. LLWS THROUGH ABOUT
1500FT WILL DEVELOP AFTER MIDNIGHT...AND THEN DIMINISH SUNDAY
MORNING AS WINDS MIX AGAIN.
VFR CIGS WILL STICK AROUND SUNDAY...WITH RAIN SHOWERS POSSIBLE IN
NORTH-CENTRAL WISCONSIN AFTER DAYBREAK AS A LOW PRESSURE SYSTEM
LIFTS TO THE NORTH AND WEST OF THE STATE...WITH ONLY VERY LIGHT
RAIN AND PCPN EXPECTED. EASTERN TAF SITES SHOULD STAY DRY UNTIL AT
LEAST MIDDAY IF NOT MOST OF SUNDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR WIZ035.
&&
$$
UPDATE.........MPC
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......ALLEN
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
612 AM CDT SAT APR 18 2015
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.UPDATE...
ISSUED AT 407 AM CDT SAT APR 18 2015
AFTER FURTHER COORDINATION WITH ARX AND THE DNR...WILL ISSUE A RED
FLAG WARNING FOR WOOD COUNTY. THE COMBO OF HUMIDITIES FALLING NEAR
20 PCT THIS AFTERNOON...MAX TEMPS IN THE 60S...WIND SPEEDS OF 10
TO 20 MPH...AND DRY FUELS WILL LEAD TO A CRITICAL FIRE WEATHER DAY
THERE. THIS RED FLAG WARNING WILL TARGET THE PINE COUNTRY OF
CENTRAL WISCONSIN.
ADDITIONALLY...THE COLD FRONT HAS JUST PASSED OVER GREEN BAY.
WINDS HAVE SHIFTED TO THE NORTH AND ARE GUSTING TO 22 KNOTS AT THE
GRB AIRPORT. SOME GUSTS UP TO 25 KNOTS OVER THE BAY ARE ALSO OCCURRING.
&&
.SHORT TERM...TODAY...TONIGHT...AND SUNDAY
ISSUED AT 330 AM CDT SAT APR 18 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A FAIRLY
POTENT COLD FRONT DROPPING SOUTH OVER FAR N-C WISCONSIN AND THE
CENTRAL UPPER PENINSULA. NORTH WINDS BEHIND THE FRONT COMBINED WITH
IMPRESSIVE PRESSURE RISES ARE CONTRIBUTING TO WIND GUSTS OVER 30 KTS
OVER LAKE SUPERIOR. AS THE FRONT MOVES ACROSS NORTHERN WISCONSIN
EARLY THIS MORNING...EXPECT NORTH WINDS TO STRENGTHEN AND BECOME
GUSTY FOR PERIOD. ELSEWHERE...UPPER LEVEL LOW PRESSURE CONTINUES TO
SPIN OVER THE CENTRAL ROCKIES AND PRODUCE SHOWERS AND THUNDERSTORMS
ACROSS THE CENTRAL GREAT PLAINS. FORECAST CONCERNS INCLUDE FIRE
WEATHER PARAMETERS TODAY...AND PRECIP CHANCES ON SUNDAY.
TODAY...THE DRY COLD FRONT WILL DROP SOUTH ACROSS THE REST OF
NORTHERN WISCONSIN EARLY THIS MORNING AND CENTRAL WISCONSIN BY
MID-MORNING. BEHIND THE FRONT...THE MODELS ARE STILL DEPICTING VERY
DRY AIR TO MOVE INTO NORTH-CENTRAL TO EAST-CENTRAL WISCONSIN TODAY.
THOUGH NORTHEAST WINDS OFF LAKE MICHIGAN WILL HELP MODERATE THE DRY
AIR OVER EASTERN WISCONSIN...MODEST WIND SPEEDS SHOULD BE ABLE TO TAP INTO
THIS VERY DRY AIR JUST ABOVE THE INVERSION...AROUND 900MB. SO WAS
AGGRESSIVE IN DROPPING HUMIDITIES TODAY...WHICH SHOULD FALL INTO THE
TEENS OVER N-C WISCONSIN AND TO AROUND 25 PCT OVER CENTRAL
WISCONSIN. EAST WINDS WILL ALSO BE APPROACHING CRITICALLY SUSTAINED
SPEEDS OVER CENTRAL WISCONSIN THIS AFTERNOON. STILL WAITING FOR A
FINAL DECISION FROM THE DNR CONCERNING A RED FLAG WARNING...WHICH SHOULD
HAVE BY 5 AM. OTHERWISE...WILL SEE A SUNNY AND COOLER DAY. HIGHS
IN THE LOW TO MID 60S AWAY FROM LAKE MICHIGAN.
TONIGHT...CLOUDS WILL BE ON THE INCREASE AS THE CENTRAL ROCKIES
UPPER LOW MOVES ACROSS THE CENTRAL PLAINS...WHILE A NORTHERN STREAM
WAVE DIGS OVER THE NORTHERN PLAINS. AS CLOUDS THICKEN AND
LOWER...WINDS BELOW 900MB WILL REMAIN OUT OF THE SOUTHEAST AND
CONTINUE TO ADVECT VERY DRY AIR OVER THE REGION. THIS DRY AIR WILL
HAVE TO BE OVERCOME...AND THIS MAY NOT OCCUR UNTIL LATE IN THE NIGHT
OVER THE WEST. WILL MODIFY PRECIP CHANCES SLIGHTLY TO REFLECT THIS.
LOWS RANGING FROM THE MID 30S NORTH TO THE MID 40S SOUTHWEST.
SUNDAY...MID-LEVEL HEIGHT FALLS WILL CONTINUE TO ADVANCE INTO THE
WESTERN GREAT LAKES. ONE AREA OF LOW PRESSURE WILL MOVE INTO
WESTERN WISCONSIN DURING THE AFTERNOON...WHILE A SOUTHERN STREAM LOW
SWINGS NE TOWARDS THE SOUTHERN TIP OF LAKE MICHIGAN. FORCING WILL
IMPROVE THROUGH THE DAY AHEAD OF THESE FEATURES...THOUGH THE LEAD BAND OF
LIGHT RAIN MAY DECAY DURING THE MORNING AS A RESULT OF THE DRY LOW
LEVEL FLOW. THEN A SECOND ROUND OF PRECIP MAY TRY TO MOVE INTO THE
AREA WITH THE APPROACHING LOW PRESSURE SYSTEMS. TEMPS ARE DIFFICULT
BECAUSE OF THE PRECIP POTENTIAL...AMPLE CLOUD COVER...AND EAST
WINDS. HAVE DROPPED TEMPS SOME SINCE TEMPS DO NOT TYPICALLY RISE
WELL WHEN THERE IS CLOUD COVER AND EAST WINDS. PRECIP WILL ALSO
LIKELY HOLD TEMPS BACK OVER CENTRAL AND NORTH-CENTRAL WISCONSIN. SO
WENT WITH HIGHS RANGING FROM THE MID 50S NORTH TO LOW 60S SOUTH.
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY
ISSUED AT 330 AM CDT SAT APR 18 2015
500MB TROUGH WILL EVOLVE INTO A CLOSED UPPER LOW OVER THE WESTERN
GREAT LAKES REGION EARLY NEXT WEEK...THEN MEANDER ACROSS EASTERN
CANADA AND THE GREAT LAKES REGION THROUGH THE END OF NEXT WEEK.
THIS WILL LEAD TO COOL AND UNSETTLED CONDITIONS...ALONG WITH A
CHANCE OF SNOW LATE AT NIGHT AND EARLY MORNING HOURS.
RAINFALL TOTALS STILL PROBLEMATIC SUNDAY NIGHT AS TWO SEPARATE
SYSTEMS WILL BRING RAIN TO THE AREA. NORTHERN STREAM SYSTEM WILL
BRING RAIN TO THE WESTERN HALF OF THE STATE...MEANWHILE A FAIRLY
POTENT LOW PRESSURE SYSTEM WILL MOVE NORTHEAST INTO THE GREAT
LAKES REGION SUNDAY NIGHT. STILL A LOT OF QUESTIONS ON TRACK OF
SYSTEM DUE TO CLOSING UPPER LOW NORTHWEST OF THE STATE. MODEL QPF
WOULD SUGGEST THAT MUCH NEEDED RAIN WOULD FALL ACROSS THE REGION.
MAIN QUESTION IS WHERE AXIS OF HEAVIER RAIN WOULD FALL. MODEL
RUN TO RUN CONTINUITY HAS NOT BEEN CONSISTENT...THUS LOW CONFIDENCE
IN THE RAINFALL AMOUNT FORECAST. MONDAY IS NOT MUCH CLEARER AS SOME
OF THE MODELS BRING DRY SLOT ACROSS THE AREA WITH A SIGNIFICANT DOWNWARD
TREND IN RAINFALL AMOUNTS. THE ECMWF/CANADIAN DO NOT SHARE THIS TREND
WITH THE WRF/GFS...THUS WILL KEEP SCATTERED DEPICTION/WORDING IN
THE FORECAST.
AS UPPER LOW CLOSES MONDAY NIGHT THROUGH WEDNESDAY...COOL CYCLONIC FLOW
AND WEAK DISTURBANCES MOVING THROUGH THE MEAN FLOW WILL BRING
CHANCES OF RAIN AND SNOW SHOWERS DEPENDING ON LOCATION AND TIMING
OF THE DAY. AT SOME POINT...THERE COULD BE A MINOR ACCUMULATION OF
SNOW ACROSS THE NORTH. SOME MODERATION IN TEMPERATURES IS EXPECTED BY
THE END OF THE WEEK AS THE UPPER LOW GRADUALLY SHIFTS EAST OF THE AREA.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 610 AM CDT SAT APR 18 2015
A COLD FRONT HAS MOVED THROUGH THE REGION...SHIFTING
WINDS TO THE NORTHEAST. THESE NE WINDS WILL BE GUSTY AT TIMES TODAY
OVER CENTRAL AND NORTHEAST WISCONSIN. THE GUSTINESS WILL DIMINISH
THIS EVENING...BUT WILL SEE THICKENING AND LOWERING CLOUDS THROUGH
THE NIGHT. RAIN WILL LIKELY HOLD OFF AT THE TAF SITES UNTIL
SUNDAY MORNING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 11 AM THIS MORNING TO 7 PM CDT THIS
EVENING FOR WIZ035.
&&
$$
UPDATE.........MPC
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
411 AM CDT SAT APR 18 2015
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 407 AM CDT SAT APR 18 2015
AFTER FURTHER COORDINATION WITH ARX AND THE DNR...WILL ISSUE A RED
FLAG WARNING FOR WOOD COUNTY. THE COMBO OF HUMIDITIES FALLING NEAR
20 PCT THIS AFTERNOON...MAX TEMPS IN THE 60S...WIND SPEEDS OF 10
TO 20 MPH...AND DRY FUELS WILL LEAD TO A CRITICAL FIRE WEATHER DAY
THERE. THIS RED FLAG WARNING WILL TARGET THE PINE COUNTRY OF
CENTRAL WISCONSIN.
ADDITIONALLY...THE COLD FRONT HAS JUST PASSED OVER GREEN BAY.
WINDS HAVE SHIFTED TO THE NORTH AND ARE GUSTING TO 22 KNOTS AT THE
GRB AIRPORT. SOME GUSTS UP TO 25 KNOTS OVER THE BAY ARE ALSO OCCURRING.
&&
.SHORT TERM...TODAY...TONIGHT...AND SUNDAY
ISSUED AT 330 AM CDT SAT APR 18 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A FAIRLY
POTENT COLD FRONT DROPPING SOUTH OVER FAR N-C WISCONSIN AND THE
CENTRAL UPPER PENINSULA. NORTH WINDS BEHIND THE FRONT COMBINED WITH
IMPRESSIVE PRESSURE RISES ARE CONTRIBUTING TO WIND GUSTS OVER 30 KTS
OVER LAKE SUPERIOR. AS THE FRONT MOVES ACROSS NORTHERN WISCONSIN
EARLY THIS MORNING...EXPECT NORTH WINDS TO STRENGTHEN AND BECOME
GUSTY FOR PERIOD. ELSEWHERE...UPPER LEVEL LOW PRESSURE CONTINUES TO
SPIN OVER THE CENTRAL ROCKIES AND PRODUCE SHOWERS AND THUNDERSTORMS
ACROSS THE CENTRAL GREAT PLAINS. FORECAST CONCERNS INCLUDE FIRE
WEATHER PARAMETERS TODAY...AND PRECIP CHANCES ON SUNDAY.
TODAY...THE DRY COLD FRONT WILL DROP SOUTH ACROSS THE REST OF
NORTHERN WISCONSIN EARLY THIS MORNING AND CENTRAL WISCONSIN BY
MID-MORNING. BEHIND THE FRONT...THE MODELS ARE STILL DEPICTING VERY
DRY AIR TO MOVE INTO NORTH-CENTRAL TO EAST-CENTRAL WISCONSIN TODAY.
THOUGH NORTHEAST WINDS OFF LAKE MICHIGAN WILL HELP MODERATE THE DRY
AIR OVER EASTERN WISCONSIN...MODEST WIND SPEEDS SHOULD BE ABLE TO TAP INTO
THIS VERY DRY AIR JUST ABOVE THE INVERSION...AROUND 900MB. SO WAS
AGGRESSIVE IN DROPPING HUMIDITIES TODAY...WHICH SHOULD FALL INTO THE
TEENS OVER N-C WISCONSIN AND TO AROUND 25 PCT OVER CENTRAL
WISCONSIN. EAST WINDS WILL ALSO BE APPROACHING CRITICALLY SUSTAINED
SPEEDS OVER CENTRAL WISCONSIN THIS AFTERNOON. STILL WAITING FOR A
FINAL DECISION FROM THE DNR CONCERNING A RED FLAG WARNING...WHICH SHOULD
HAVE BY 5 AM. OTHERWISE...WILL SEE A SUNNY AND COOLER DAY. HIGHS
IN THE LOW TO MID 60S AWAY FROM LAKE MICHIGAN.
TONIGHT...CLOUDS WILL BE ON THE INCREASE AS THE CENTRAL ROCKIES
UPPER LOW MOVES ACROSS THE CENTRAL PLAINS...WHILE A NORTHERN STREAM
WAVE DIGS OVER THE NORTHERN PLAINS. AS CLOUDS THICKEN AND
LOWER...WINDS BELOW 900MB WILL REMAIN OUT OF THE SOUTHEAST AND
CONTINUE TO ADVECT VERY DRY AIR OVER THE REGION. THIS DRY AIR WILL
HAVE TO BE OVERCOME...AND THIS MAY NOT OCCUR UNTIL LATE IN THE NIGHT
OVER THE WEST. WILL MODIFY PRECIP CHANCES SLIGHTLY TO REFLECT THIS.
LOWS RANGING FROM THE MID 30S NORTH TO THE MID 40S SOUTHWEST.
SUNDAY...MID-LEVEL HEIGHT FALLS WILL CONTINUE TO ADVANCE INTO THE
WESTERN GREAT LAKES. ONE AREA OF LOW PRESSURE WILL MOVE INTO
WESTERN WISCONSIN DURING THE AFTERNOON...WHILE A SOUTHERN STREAM LOW
SWINGS NE TOWARDS THE SOUTHERN TIP OF LAKE MICHIGAN. FORCING WILL
IMPROVE THROUGH THE DAY AHEAD OF THESE FEATURES...THOUGH THE LEAD BAND OF
LIGHT RAIN MAY DECAY DURING THE MORNING AS A RESULT OF THE DRY LOW
LEVEL FLOW. THEN A SECOND ROUND OF PRECIP MAY TRY TO MOVE INTO THE
AREA WITH THE APPROACHING LOW PRESSURE SYSTEMS. TEMPS ARE DIFFICULT
BECAUSE OF THE PRECIP POTENTIAL...AMPLE CLOUD COVER...AND EAST
WINDS. HAVE DROPPED TEMPS SOME SINCE TEMPS DO NOT TYPICALLY RISE
WELL WHEN THERE IS CLOUD COVER AND EAST WINDS. PRECIP WILL ALSO
LIKELY HOLD TEMPS BACK OVER CENTRAL AND NORTH-CENTRAL WISCONSIN. SO
WENT WITH HIGHS RANGING FROM THE MID 50S NORTH TO LOW 60S SOUTH.
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY
ISSUED AT 330 AM CDT SAT APR 18 2015
500MB TROUGH WILL EVOLVE INTO A CLOSED UPPER LOW OVER THE WESTERN
GREAT LAKES REGION EARLY NEXT WEEK...THEN MEANDER ACROSS EASTERN
CANADA AND THE GREAT LAKES REGION THROUGH THE END OF NEXT WEEK.
THIS WILL LEAD TO COOL AND UNSETTLED CONDITIONS...ALONG WITH A
CHANCE OF SNOW LATE AT NIGHT AND EARLY MORNING HOURS.
RAINFALL TOTALS STILL PROBLEMATIC SUNDAY NIGHT AS TWO SEPARATE
SYSTEMS WILL BRING RAIN TO THE AREA. NORTHERN STREAM SYSTEM WILL
BRING RAIN TO THE WESTERN HALF OF THE STATE...MEANWHILE A FAIRLY
POTENT LOW PRESSURE SYSTEM WILL MOVE NORTHEAST INTO THE GREAT
LAKES REGION SUNDAY NIGHT. STILL A LOT OF QUESTIONS ON TRACK OF
SYSTEM DUE TO CLOSING UPPER LOW NORTHWEST OF THE STATE. MODEL QPF
WOULD SUGGEST THAT MUCH NEEDED RAIN WOULD FALL ACROSS THE REGION.
MAIN QUESTION IS WHERE AXIS OF HEAVIER RAIN WOULD FALL. MODEL
RUN TO RUN CONTINUITY HAS NOT BEEN CONSISTENT...THUS LOW CONFIDENCE
IN THE RAINFALL AMOUNT FORECAST. MONDAY IS NOT MUCH CLEARER AS SOME
OF THE MODELS BRING DRY SLOT ACROSS THE AREA WITH A SIGNIFICANT DOWNWARD
TREND IN RAINFALL AMOUNTS. THE ECMWF/CANADIAN DO NOT SHARE THIS TREND
WITH THE WRF/GFS...THUS WILL KEEP SCATTERED DEPICTION/WORDING IN
THE FORECAST.
AS UPPER LOW CLOSES MONDAY NIGHT THROUGH WEDNESDAY...COOL CYCLONIC FLOW
AND WEAK DISTURBANCES MOVING THROUGH THE MEAN FLOW WILL BRING
CHANCES OF RAIN AND SNOW SHOWERS DEPENDING ON LOCATION AND TIMING
OF THE DAY. AT SOME POINT...THERE COULD BE A MINOR ACCUMULATION OF
SNOW ACROSS THE NORTH. SOME MODERATION IN TEMPERATURES IS EXPECTED BY
THE END OF THE WEEK AS THE UPPER LOW GRADUALLY SHIFTS EAST OF THE AREA.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1100 PM CDT FRI APR 17 2015
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. A DRY COLD FRONT
WILL ARRIVE LATER TONIGHT. WINDS WILL SHIFT TO THE NORTHEAST BEHIND
THE FRONT...AND BECOME GUSTY FOR A FEW HOURS TODAY...ESPECIALLY IN
EASTERN WISCONSIN. WINDS WILL DIE DOWN AGAIN SATURDAY EVENING WITH
THICKENING MID CLOUDS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 11 AM THIS MORNING TO 7 PM CDT THIS
EVENING FOR WIZ035.
&&
$$
UPDATE.........MPC
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......KURIMSKI
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND SUNDAY
ISSUED AT 330 AM CDT SAT APR 18 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A FAIRLY
POTENT COLD FRONT DROPPING SOUTH OVER FAR N-C WISCONSIN AND THE
CENTRAL UPPER PENINSULA. NORTH WINDS BEHIND THE FRONT COMBINED WITH
IMPRESSIVE PRESSURE RISES ARE CONTRIBUTING TO WIND GUSTS OVER 30 KTS
OVER LAKE SUPERIOR. AS THE FRONT MOVES ACROSS NORTHERN WISCONSIN
EARLY THIS MORNING...EXPECT NORTH WINDS TO STRENGTHEN AND BECOME
GUSTY FOR PERIOD. ELSEWHERE...UPPER LEVEL LOW PRESSURE CONTINUES TO
SPIN OVER THE CENTRAL ROCKIES AND PRODUCE SHOWERS AND THUNDERSTORMS
ACROSS THE CENTRAL GREAT PLAINS. FORECAST CONCERNS INCLUDE FIRE
WEATHER PARAMETERS TODAY...AND PRECIP CHANCES ON SUNDAY.
TODAY...THE DRY COLD FRONT WILL DROP SOUTH ACROSS THE REST OF
NORTHERN WISCONSIN EARLY THIS MORNING AND CENTRAL WISCONSIN BY
MID-MORNING. BEHIND THE FRONT...THE MODELS ARE STILL DEPICTING VERY
DRY AIR TO MOVE INTO NORTH-CENTRAL TO EAST-CENTRAL WISCONSIN TODAY.
THOUGH NORTHEAST WINDS OFF LAKE MICHIGAN WILL HELP MODERATE THE DRY
AIR OVER EASTERN WISCONSIN...MODEST WIND SPEEDS SHOULD BE ABLE TO TAP INTO
THIS VERY DRY AIR JUST ABOVE THE INVERSION...AROUND 900MB. SO WAS
AGGRESSIVE IN DROPPING HUMIDITIES TODAY...WHICH SHOULD FALL INTO THE
TEENS OVER N-C WISCONSIN AND TO AROUND 25 PCT OVER CENTRAL
WISCONSIN. EAST WINDS WILL ALSO BE APPROACHING CRITICALLY SUSTAINED
SPEEDS OVER CENTRAL WISCONSIN THIS AFTERNOON. STILL WAITING FOR A
FINAL DECISION FROM THE DNR CONCERNING A RED FLAG WARNING...WHICH SHOULD
HAVE BY 5 AM. OTHERWISE...WILL SEE A SUNNY AND COOLER DAY. HIGHS
IN THE LOW TO MID 60S AWAY FROM LAKE MICHIGAN.
TONIGHT...CLOUDS WILL BE ON THE INCREASE AS THE CENTRAL ROCKIES
UPPER LOW MOVES ACROSS THE CENTRAL PLAINS...WHILE A NORTHERN STREAM
WAVE DIGS OVER THE NORTHERN PLAINS. AS CLOUDS THICKEN AND
LOWER...WINDS BELOW 900MB WILL REMAIN OUT OF THE SOUTHEAST AND
CONTINUE TO ADVECT VERY DRY AIR OVER THE REGION. THIS DRY AIR WILL
HAVE TO BE OVERCOME...AND THIS MAY NOT OCCUR UNTIL LATE IN THE NIGHT
OVER THE WEST. WILL MODIFY PRECIP CHANCES SLIGHTLY TO REFLECT THIS.
LOWS RANGING FROM THE MID 30S NORTH TO THE MID 40S SOUTHWEST.
SUNDAY...MID-LEVEL HEIGHT FALLS WILL CONTINUE TO ADVANCE INTO THE
WESTERN GREAT LAKES. ONE AREA OF LOW PRESSURE WILL MOVE INTO
WESTERN WISCONSIN DURING THE AFTERNOON...WHILE A SOUTHERN STREAM LOW
SWINGS NE TOWARDS THE SOUTHERN TIP OF LAKE MICHIGAN. FORCING WILL
IMPROVE THROUGH THE DAY AHEAD OF THESE FEATURES...THOUGH THE LEAD BAND OF
LIGHT RAIN MAY DECAY DURING THE MORNING AS A RESULT OF THE DRY LOW
LEVEL FLOW. THEN A SECOND ROUND OF PRECIP MAY TRY TO MOVE INTO THE
AREA WITH THE APPROACHING LOW PRESSURE SYSTEMS. TEMPS ARE DIFFICULT
BECAUSE OF THE PRECIP POTENTIAL...AMPLE CLOUD COVER...AND EAST
WINDS. HAVE DROPPED TEMPS SOME SINCE TEMPS DO NOT TYPICALLY RISE
WELL WHEN THERE IS CLOUD COVER AND EAST WINDS. PRECIP WILL ALSO
LIKELY HOLD TEMPS BACK OVER CENTRAL AND NORTH-CENTRAL WISCONSIN. SO
WENT WITH HIGHS RANGING FROM THE MID 50S NORTH TO LOW 60S SOUTH.
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY
ISSUED AT 330 AM CDT SAT APR 18 2015
500MB TROUGH WILL EVOLVE INTO A CLOSED UPPER LOW OVER THE WESTERN
GREAT LAKES REGION EARLY NEXT WEEK...THEN MEANDER ACROSS EASTERN
CANADA AND THE GREAT LAKES REGION THROUGH THE END OF NEXT WEEK.
THIS WILL LEAD TO COOL AND UNSETTLED CONDITIONS...ALONG WITH A
CHANCE OF SNOW LATE AT NIGHT AND EARLY MORNING HOURS.
RAINFALL TOTALS STILL PROBLEMATIC SUNDAY NIGHT AS TWO SEPARATE
SYSTEMS WILL BRING RAIN TO THE AREA. NORTHERN STREAM SYSTEM WILL
BRING RAIN TO THE WESTERN HALF OF THE STATE...MEANWHILE A FAIRLY
POTENT LOW PRESSURE SYSTEM WILL MOVE NORTHEAST INTO THE GREAT
LAKES REGION SUNDAY NIGHT. STILL A LOT OF QUESTIONS ON TRACK OF
SYSTEM DUE TO CLOSING UPPER LOW NORTHWEST OF THE STATE. MODEL QPF
WOULD SUGGEST THAT MUCH NEEDED RAIN WOULD FALL ACROSS THE REGION.
MAIN QUESTION IS WHERE AXIS OF HEAVIER RAIN WOULD FALL. MODEL
RUN TO RUN CONTINUITY HAS NOT BEEN CONSISTENT...THUS LOW CONFIDENCE
IN THE RAINFALL AMOUNT FORECAST. MONDAY IS NOT MUCH CLEARER AS SOME
OF THE MODELS BRING DRY SLOT ACROSS THE AREA WITH A SIGNIFICANT DOWNWARD
TREND IN RAINFALL AMOUNTS. THE ECMWF/CANADIAN DO NOT SHARE THIS TREND
WITH THE WRF/GFS...THUS WILL KEEP SCATTERED DEPICTION/WORDING IN
THE FORECAST.
AS UPPER LOW CLOSES MONDAY NIGHT THROUGH WEDNESDAY...COOL CYCLONIC FLOW
AND WEAK DISTURBANCES MOVING THROUGH THE MEAN FLOW WILL BRING
CHANCES OF RAIN AND SNOW SHOWERS DEPENDING ON LOCATION AND TIMING
OF THE DAY. AT SOME POINT...THERE COULD BE A MINOR ACCUMULATION OF
SNOW ACROSS THE NORTH. SOME MODERATION IN TEMPERATURES IS EXPECTED BY
THE END OF THE WEEK AS THE UPPER LOW GRADUALLY SHIFTS EAST OF THE AREA.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1100 PM CDT FRI APR 17 2015
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. A DRY COLD FRONT
WILL ARRIVE LATER TONIGHT. WINDS WILL SHIFT TO THE NORTHEAST BEHIND
THE FRONT...AND BECOME GUSTY FOR A FEW HOURS TODAY...ESPECIALLY IN
EASTERN WISCONSIN. WINDS WILL DIE DOWN AGAIN SATURDAY EVENING WITH
THICKENING MID CLOUDS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......KURIMSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
243 PM MDT SAT APR 18 2015
.UPDATE...
ISSUED AT 239 PM MDT SAT APR 18 2015
TORNADO WATCH ISSUED FOR CHEYENNE COUNTY AND MORRILL COUNTY IN THE
SOUTHERN NEBRASKA PANHANDLE UNTIL 8 PM. BASED ON CURRENT MESOSCALE
ANALYSIS...THE MAIN THREATS ARE MARGINAL SEVERE HAIL AND FUNNEL
CLOUDS THIS AFTERNOON...BUT AN ISOLATED BRIEF TORNADO IS NOT OUT
OF THE QUESTION IN THE WATCH COUNTIES. MOST LIKELY THE BOUNDARY
LAYER WILL STABILIZE OVER THE NEXT SEVERAL HOURS AS COLD OUTFLOW
FROM SHOWERS AND THUNDERSTORMS SPREAD ACROSS THE AREA...ENDING
ANY THREAT FOR TORNADOS.
UPDATE ISSUED AT 1135 AM MDT SAT APR 18 2015
ADJUSTED WINTER WEATHER HEADLINES FOR THE BAND OF HEAVY SNOW WHICH
IS EXPECTED TO CONTINUE OVER NORTHERN ALBANY COUNTY AND
EASTERN/CENTRAL CARBON COUNTY TODAY. ADDED THE ARLINGTON ZONE TO
THE WARNING BASE ON LATEST GFS AND NAM SHOWING HEAVY PRECIPITATION
ACROSS THIS AREA THROUGH EARLY THIS EVENING. LATEST RADAR SHOWING
THE BAND OF HEAVY TROWAL PRECIPITATION SETTING UP AT THIS TIME AND
SURFACE OBS AND WEB CAMS VERIFY THE HEAVY SNOW. MODEL SURFACE
TEMPERATURES AND MOS GUIDANCE MOST LIKELY TOO WARM AROUND
ARLINGTON GIVEN WHAT WILL BE HEAVY PRECIPITATION. EAST AND WEST OF
THIS PRECIPITATION BAND...TEMPERATURES WILL WARM AS EXPECTED.
IMPACTS ON ROADS IS A BIT OF A QUESTION WITH TEMPERATURES NEAR
FREEZING AND HIGH SUN ANGLE THAT MAY BE ABLE TO MELT MUCH OF THE
SNOW...EVEN WITHIN THE HEAVY BAND. REGARDLESS ROADS WILL AT LEAST
BE SLUSHY AT TIMES...IF NOT COMPLETELY SNOW COVERED. MOST SNOW
ACCUMULATIONS WILL BE ON ELEVATED SURFACES AND OVER CURRENT SNOW
COVER.
WINTER WEATHER HEADLINES HAVE BEEN CANCELLED FOR THE SOUTHERN
LARAMIE RANGE AND FOOTHILLS WITH THE BAND OF SNOW SETTING UP WEST
OF THE THIS AREA. THERE IS THE POTENTIAL FOR SOME SNOW SHOWERS
THIS AFTERNOON. AS THE TROWAL SHIFTS EAST THIS EVENING THERE WILL
LIKELY BE A PERIOD OF SNOW OVER THE SOUTHERN LARAMIE RANGE BUT
ACCUMULATIONS WILL BE MINIMAL...MAYBE AN INCH OR TWO OF NEW
ACCUMULATIONS.
UPDATE ISSUED AT 1009 AM MDT SAT APR 18 2015
ADJUSTED POPS SLIGHTLY TO REFLECT THE POSITION OF THE TROWAL THIS
MORNING. THE TROWAL WHICH IS VERY DISTINGUISHABLE ON SATELLITE AND
RADAR WILL MOVE SLIGHTLY WESTWARD THROUGH EARLY AFTERNOON. AT THAT
POINT IT WILL STALL AND THEN SHIFT EAST INTO THIS EVENING AS A
NORTHERN STREAM KICKER PUSHES THE CLOSED UPPER LOW INTO THE
PLAINS.
LOWERED TEMPERATURES ACROSS THE WEST TODAY AS TROWAL PRECIPITATION
WILL HOLD TEMPERATURES DOWN...KEEPING MOST PRECIPITATION WEST OF
THE LARAMIE RANGE AS SNOW BUT SOME PLACES WILL MIX WITH OR CHANGE
TO RAIN. WILL KEEP AN EYE ON THINGS BUT MAY NEED TO LOWER
TEMPERATURES IN THE WEST A BIT MORE. LARAMIE SHOULD SEE SNOW
THROUGH THE DAY WITH SEVERAL MORE INCHES OF SNOWFALL. WITH
TEMPERATURES NEAR FREEZING AROUND LARAMIE AND THE RELATIVELY HIGH
APRIL SUN ANGLE...NOT MUCH SNOW WILL ACCUMULATE ON ROADS WAYS WITH
WET TO SLUSHY ROADS EXPECTED.
EAST OF THE LARAMIE RANGE THERE IS THE POTENTIAL FOR THUNDERSTORMS
THIS AFTERNOON. MODELS SHOWING 500-1000 J/KG OF MOST UNSTABLE
CAPE. SHEAR VALUES ARE NOT IMPRESSIVE...BUT GIVEN THE COLD NATURE
OF THIS SYSTEM...IT IS LIKELY THERE WILL BE SOME SMALL HAIL TODAY
AND WITH LOW FREEZING LEVELS...MARGINAL SEVERE HAIL NOT OUT OF THE
QUESTION WITH ANY STRONGER UPDRAFTS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 415 AM MDT SAT APR 18 2015
TODAY...SLOW MOVING CLOSED UPPER LOW PROGGED TO MOVE FROM CENTRAL
COLORADO THIS MORNING TO EAST CENTRAL COLORADO BY DINNER TIME. ALL
MODELS INCLUDING THE HRRR SHOW A BAND OF PRECIPITATION SWINGING
WESTWARD ACROSS OUR COUNTIES THIS MORNING AND AFTERNOON WITH DECENT
UPWARD VERTICAL MOTION AND QUASIGEOSTROPHIC FORCING...THUS HAVE
OPTED TO EXTEND OUR WINTER WEATHER ADVISORIES AND WINTER STORM
WARNINGS THROUGH MIDDAY...WHILE DROPPING CHEYENNE FROM THE ADVISORY
WITH TEMPERATURES LIKELY REMAINING ABOVE FREEZING AND THUS MINIMAL
IMPACTS TO TRAVEL.
TONIGHT...FINALLY...THE UPPER TROUGH OPENS UP AS A NORTHERN STREAM
SHORTWAVE TROUGH ALOFT MOVES EASTWARD INTO WESTERN NORTH
DAKOTA...THUS PRECIPITATION CHANCES DWINDLE AS THE NIGHT PROGRESSES.
SUNDAY...BREEZY TO WINDY...AND COOL WITH BRISK NORTHWEST FLOW ALOFT
AND DEEP UNIDIRECTIONAL WINDS. LOOKS LIKE ENOUGH LOW AND MID LEVEL
MOISTURE FOR ISOLATED TO SCATTERED SHOWERS OVER AND NEAR OUR
NORTHERN LARAMIE...SNOWY AND SIERRA MADRE RANGES...WITH MOSTLY DRY
CONDITIONS ELSEWHERE.
SUNDAY NIGHT...MOIST OROGRAPHIC NORTHWEST FLOW ALOFT CONTINUES
PRODUCING SCATTERED TO NUMEROUS SNOW SHOWERS OVER AND NEAR OUR
SNOWY...SIERRA MADRE AND LARAMIE RANGES...DRY ELSEWHERE.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 415 AM MDT SAT APR 18 2015N
THE EXTENDED PERIOD WILL START OUT TRANQUIL AND THEN END
POTENTIALLY UNSETTLED. NORTHWESTERLY FLOW ALOFT WILL BE IN PLACE
ON MON WITH A WEAK SHORTWAVE MOVING OVERHEAD DURING THE DAY. COULD
BE SOME LIGHT SNOW SHOWERS OVER THE SIERRA MADRE AND SNOWY
RANGES...BUT MUCH OF THE ACTIVITY WILL BE CONFINED TO NORTHERN
COLORADO. WITH 700MB TEMPS AROUND -6C...IT WILL BE ANOTHER DAY OF
BELOW NORMAL TEMPS. WE FINALLY GET TEMPS TO MODERATE SOME BY TUES
AND ESPECIALLY INTO WED...BACK INTO THE 50S AND 60S TO THE EAST OF
THE LARAMIE RANGE. A BUILDING SFC HIGH OVER THE NORTHERN PLAINS ON
THURS WILL CAUSE SOUTHEAST WINDS TO DEVELOP ACROSS THE PLAINS.
WEAK INSTABILITY WILL BE PRESENT ON THURS AFTN...SO INCLUDED A
SLIGHT OF TSTMS. A SHORTWAVE WILL THEN LIFT NORTHEASTWARD FROM
ARIZONA INTO COLORADO ON FRI. BOTH THE GFS AND ECMWF INDICATE THE
BEST CHANCE OF WIDESPREAD PRECIP COULD BE FRI AFTN INTO FRI NIGHT
WITH GOOD EASTERLY UPSLOPE FLOW OVER THE PLAINS. 700MB TEMPS ARE
AROUND -2C...SO COULD BE DEALING WITH ANOTHER CASE WHERE SNOW IS
LARGELY CONFINED TO AREAS ALONG AND WEST OF THE LARAMIE RANGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH SUNDAY MORNING)
THE LARGE AREA OF LIGHT SNOW IS CURRENTLY ALONG AND JUST WEST OF THE
LARAMIE RANGE AND MOVING SLIGHTLY WESTWARD. IFR CONDITIONS AND LIGHT
SNOW WILL CONTINUE BETWEEN KRWL AND KLAR THIS AFTERNOON...WITH MVFR
CONDITIONS EXPECTED AT KRWL...AND IFR CONDITIONS AT KLAR. IFR
CONDITIONS DUE TO LOW CIGS WILL CONTINUE AT KCYS...BUT CONDITIONS
SHOULD IMPROVE A BIT THROUGH THE AFTERNOON AS SHOWERS BEGIN TO
DEVELOP TO THE SOUTH. A COLD FRONT WILL PUSH ACROSS THE PLAINS BY
LATE THIS EVENING (AFTER 03Z) WITH BREEZY NORTH WINDS EXPECTED.
&&
.FIRE WEATHER...
ISSUED AT 402 AM MDT SAT APR 18 2015
NO FIRE WEATHER ISSUES WITH RECENT WIDESPREAD
PRECIPITATION...AND PROJECTED HUMIDITIES AND WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 9 PM MDT THIS EVENING FOR WYZ110-114.
WINTER WEATHER ADVISORY UNTIL 9 PM MDT THIS EVENING FOR WYZ103-
105-106-112-113-115.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...RUBIN
LONG TERM...ZF
AVIATION...TJT
FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1136 AM MDT SAT APR 18 2015
.UPDATE...
ISSUED AT 1135 AM MDT SAT APR 18 2015
ADJUSTED WINTER WEATHER HEADLINES FOR THE BAND OF HEAVY SNOW WHICH
IS EXPECTED TO CONTINUE OVER NORTHERN ALBANY COUNTY AND
EASTERN/CENTRAL CARBON COUNTY TODAY. ADDED THE ARLINGTON ZONE TO
THE WARNING BASE ON LATEST GFS AND NAM SHOWING HEAVY PRECIPITATION
ACROSS THIS AREA THROUGH EARLY THIS EVENING. LATEST RADAR SHOWING
THE BAND OF HEAVY TROWAL PRECIPITATION SETTING UP AT THIS TIME AND
SURFACE OBS AND WEB CAMS VERIFY THE HEAVY SNOW. MODEL SURFACE
TEMPERATURES AND MOS GUIDANCE MOST LIKELY TOO WARM AROUND
ARLINGTON GIVEN WHAT WILL BE HEAVY PRECIPITATION. EAST AND WEST OF
THIS PRECIPITATION BAND...TEMPERATURES WILL WARM AS EXPECTED.
IMPACTS ON ROADS IS A BIT OF A QUESTION WITH TEMPERATURES NEAR
FREEZING AND HIGH SUN ANGLE THAT MAY BE ABLE TO MELT MUCH OF THE
SNOW...EVEN WITHIN THE HEAVY BAND. REGARDLESS ROADS WILL AT LEAST
BE SLUSHY AT TIMES...IF NOT COMPLETELY SNOW COVERED. MOST SNOW
ACCUMULATIONS WILL BE ON ELEVATED SURFACES AND OVER CURRENT SNOW
COVER.
WINTER WEATHER HEADLINES HAVE BEEN CANCELLED FOR THE SOUTHERN
LARAMIE RANGE AND FOOTHILLS WITH THE BAND OF SNOW SETTING UP WEST
OF THE THIS AREA. THERE IS THE POTENTIAL FOR SOME SNOW SHOWERS
THIS AFTERNOON. AS THE TROWAL SHIFTS EAST THIS EVENING THERE WILL
LIKELY BE A PERIOD OF SNOW OVER THE SOUTHERN LARAMIE RANGE BUT
ACCUMULATIONS WILL BE MINIMAL...MAYBE AN INCH OR TWO OF NEW
ACCUMULATIONS.
UPDATE ISSUED AT 1009 AM MDT SAT APR 18 2015
ADJUSTED POPS SLIGHTLY TO REFLECT THE POSITION OF THE TROWAL THIS
MORNING. THE TROWAL WHICH IS VERY DISTINGUISHABLE ON SATELLITE AND
RADAR WILL MOVE SLIGHTLY WESTWARD THROUGH EARLY AFTERNOON. AT THAT
POINT IT WILL STALL AND THEN SHIFT EAST INTO THIS EVENING AS A
NORTHERN STREAM KICKER PUSHES THE CLOSED UPPER LOW INTO THE
PLAINS.
LOWERED TEMPERATURES ACROSS THE WEST TODAY AS TROWAL PRECIPITATION
WILL HOLD TEMPERATURES DOWN...KEEPING MOST PRECIPITATION WEST OF
THE LARAMIE RANGE AS SNOW BUT SOME PLACES WILL MIX WITH OR CHANGE
TO RAIN. WILL KEEP AN EYE ON THINGS BUT MAY NEED TO LOWER
TEMPERATURES IN THE WEST A BIT MORE. LARAMIE SHOULD SEE SNOW
THROUGH THE DAY WITH SEVERAL MORE INCHES OF SNOWFALL. WITH
TEMPERATURES NEAR FREEZING AROUND LARAMIE AND THE RELATIVELY HIGH
APRIL SUN ANGLE...NOT MUCH SNOW WILL ACCUMULATE ON ROADS WAYS WITH
WET TO SLUSHY ROADS EXPECTED.
EAST OF THE LARAMIE RANGE THERE IS THE POTENTIAL FOR THUNDERSTORMS
THIS AFTERNOON. MODELS SHOWING 500-1000 J/KG OF MOST UNSTABLE
CAPE. SHEAR VALUES ARE NOT IMPRESSIVE...BUT GIVEN THE COLD NATURE
OF THIS SYSTEM...IT IS LIKELY THERE WILL BE SOME SMALL HAIL TODAY
AND WITH LOW FREEZING LEVELS...MARGINAL SEVERE HAIL NOT OUT OF THE
QUESTION WITH ANY STRONGER UPDRAFTS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 415 AM MDT SAT APR 18 2015
TODAY...SLOW MOVING CLOSED UPPER LOW PROGGED TO MOVE FROM CENTRAL
COLORADO THIS MORNING TO EAST CENTRAL COLORADO BY DINNER TIME. ALL
MODELS INCLUDING THE HRRR SHOW A BAND OF PRECIPITATION SWINGING
WESTWARD ACROSS OUR COUNTIES THIS MORNING AND AFTERNOON WITH DECENT
UPWARD VERTICAL MOTION AND QUASIGEOSTROPHIC FORCING...THUS HAVE
OPTED TO EXTEND OUR WINTER WEATHER ADVISORIES AND WINTER STORM
WARNINGS THROUGH MIDDAY...WHILE DROPPING CHEYENNE FROM THE ADVISORY
WITH TEMPERATURES LIKELY REMAINING ABOVE FREEZING AND THUS MINIMAL
IMPACTS TO TRAVEL.
TONIGHT...FINALLY...THE UPPER TROUGH OPENS UP AS A NORTHERN STREAM
SHORTWAVE TROUGH ALOFT MOVES EASTWARD INTO WESTERN NORTH
DAKOTA...THUS PRECIPITATION CHANCES DWINDLE AS THE NIGHT PROGRESSES.
SUNDAY...BREEZY TO WINDY...AND COOL WITH BRISK NORTHWEST FLOW ALOFT
AND DEEP UNIDIRECTIONAL WINDS. LOOKS LIKE ENOUGH LOW AND MID LEVEL
MOISTURE FOR ISOLATED TO SCATTERED SHOWERS OVER AND NEAR OUR
NORTHERN LARAMIE...SNOWY AND SIERRA MADRE RANGES...WITH MOSTLY DRY
CONDITIONS ELSEWHERE.
SUNDAY NIGHT...MOIST OROGRAPHIC NORTHWEST FLOW ALOFT CONTINUES
PRODUCING SCATTERED TO NUMEROUS SNOW SHOWERS OVER AND NEAR OUR
SNOWY...SIERRA MADRE AND LARAMIE RANGES...DRY ELSEWHERE.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 415 AM MDT SAT APR 18 2015N
THE EXTENDED PERIOD WILL START OUT TRANQUIL AND THEN END
POTENTIALLY UNSETTLED. NORTHWESTERLY FLOW ALOFT WILL BE IN PLACE
ON MON WITH A WEAK SHORTWAVE MOVING OVERHEAD DURING THE DAY. COULD
BE SOME LIGHT SNOW SHOWERS OVER THE SIERRA MADRE AND SNOWY
RANGES...BUT MUCH OF THE ACTIVITY WILL BE CONFINED TO NORTHERN
COLORADO. WITH 700MB TEMPS AROUND -6C...IT WILL BE ANOTHER DAY OF
BELOW NORMAL TEMPS. WE FINALLY GET TEMPS TO MODERATE SOME BY TUES
AND ESPECIALLY INTO WED...BACK INTO THE 50S AND 60S TO THE EAST OF
THE LARAMIE RANGE. A BUILDING SFC HIGH OVER THE NORTHERN PLAINS ON
THURS WILL CAUSE SOUTHEAST WINDS TO DEVELOP ACROSS THE PLAINS.
WEAK INSTABILITY WILL BE PRESENT ON THURS AFTN...SO INCLUDED A
SLIGHT OF TSTMS. A SHORTWAVE WILL THEN LIFT NORTHEASTWARD FROM
ARIZONA INTO COLORADO ON FRI. BOTH THE GFS AND ECMWF INDICATE THE
BEST CHANCE OF WIDESPREAD PRECIP COULD BE FRI AFTN INTO FRI NIGHT
WITH GOOD EASTERLY UPSLOPE FLOW OVER THE PLAINS. 700MB TEMPS ARE
AROUND -2C...SO COULD BE DEALING WITH ANOTHER CASE WHERE SNOW IS
LARGELY CONFINED TO AREAS ALONG AND WEST OF THE LARAMIE RANGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH SUNDAY MORNING)
THE LARGE AREA OF LIGHT SNOW IS CURRENTLY ALONG AND JUST WEST OF THE
LARAMIE RANGE AND MOVING SLIGHTLY WESTWARD. IFR CONDITIONS AND LIGHT
SNOW WILL CONTINUE BETWEEN KRWL AND KLAR THIS AFTERNOON...WITH MVFR
CONDITIONS EXPECTED AT KRWL...AND IFR CONDITIONS AT KLAR. IFR
CONDITIONS DUE TO LOW CIGS WILL CONTINUE AT KCYS...BUT CONDITIONS
SHOULD IMPROVE A BIT THROUGH THE AFTERNOON AS SHOWERS BEGIN TO
DEVELOP TO THE SOUTH. A COLD FRONT WILL PUSH ACROSS THE PLAINS BY
LATE THIS EVENING (AFTER 03Z) WITH BREEZY NORTH WINDS EXPECTED.
&&
.FIRE WEATHER...
ISSUED AT 402 AM MDT SAT APR 18 2015
NO FIRE WEATHER ISSUES WITH RECENT WIDESPREAD
PRECIPITATION...AND PROJECTED HUMIDITIES AND WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 9 PM MDT THIS EVENING FOR WYZ110-114.
WINTER WEATHER ADVISORY UNTIL 9 PM MDT THIS EVENING FOR WYZ103-
105-106-112-113-115.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...RUBIN
LONG TERM...ZF
AVIATION...TJT
FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1010 AM MDT SAT APR 18 2015
.UPDATE...
ISSUED AT 1009 AM MDT SAT APR 18 2015
ADJUSTED POPS SLIGHTLY TO REFLECT THE POSITION OF THE TROWAL THIS
MORNING. THE TROWAL WHICH IS VERY DISTINGUISHABLE ON SATELLITE AND
RADAR WILL MOVE SLIGHTLY WESTWARD THROUGH EARLY AFTERNOON. AT THAT
POINT IT WILL STALL AND THEN SHIFT EAST INTO THIS EVENING AS A
NORTHERN STREAM KICKER PUSHES THE CLOSED UPPER LOW INTO THE
PLAINS.
LOWERED TEMPERATURES ACROSS THE WEST TODAY AS TROWAL PRECIPITATION
WILL HOLD TEMPERATURES DOWN...KEEPING MOST PRECIPITATION WEST OF
THE LARAMIE RANGE AS SNOW BUT SOME PLACES WILL MIX WITH OR CHANGE
TO RAIN. WILL KEEP AN EYE ON THINGS BUT MAY NEED TO LOWER
TEMPERATURES IN THE WEST A BIT MORE. LARAMIE SHOULD SEE SNOW
THROUGH THE DAY WITH SEVERAL MORE INCHES OF SNOWFALL. WITH
TEMPERATURES NEAR FREEZING AROUND LARAMIE AND THE RELATIVELY HIGH
APRIL SUN ANGLE...NOT MUCH SNOW WILL ACCUMULATE ON ROADS WAYS WITH
WET TO SLUSHY ROADS EXPECTED.
EAST OF THE LARAMIE RANGE THERE IS THE POTENTIAL FOR THUNDERSTORMS
THIS AFTERNOON. MODELS SHOWING 500-1000 J/KG OF MOST UNSTABLE
CAPE. SHEAR VALUES ARE NOT IMPRESSIVE...BUT GIVEN THE COLD NATURE
OF THIS SYSTEM...IT IS LIKELY THERE WILL BE SOME SMALL HAIL TODAY
AND WITH LOW FREEZING LEVELS...MARGINAL SEVERE HAIL NOT OUT OF THE
QUESTION WITH ANY STRONGER UPDRATS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 415 AM MDT SAT APR 18 2015
TODAY...SLOW MOVING CLOSED UPPER LOW PROGGED TO MOVE FROM CENTRAL
COLORADO THIS MORNING TO EAST CENTRAL COLORADO BY DINNER TIME. ALL
MODELS INCLUDING THE HRRR SHOW A BAND OF PRECIPITATION SWINGING
WESTWARD ACROSS OUR COUNTIES THIS MORNING AND AFTERNOON WITH DECENT
UPWARD VERTICAL MOTION AND QUASIGEOSTROPHIC FORCING...THUS HAVE
OPTED TO EXTEND OUR WINTER WEATHER ADVISORIES AND WINTER STORM
WARNINGS THROUGH MIDDAY...WHILE DROPPING CHEYENNE FROM THE ADVISORY
WITH TEMPERATURES LIKELY REMAINING ABOVE FREEZING AND THUS MINIMAL
IMPACTS TO TRAVEL.
TONIGHT...FINALLY...THE UPPER TROUGH OPENS UP AS A NORTHERN STREAM
SHORTWAVE TROUGH ALOFT MOVES EASTWARD INTO WESTERN NORTH
DAKOTA...THUS PRECIPITATION CHANCES DWINDLE AS THE NIGHT PROGRESSES.
SUNDAY...BREEZY TO WINDY...AND COOL WITH BRISK NORTHWEST FLOW ALOFT
AND DEEP UNIDIRECTIONAL WINDS. LOOKS LIKE ENOUGH LOW AND MID LEVEL
MOISTURE FOR ISOLATED TO SCATTERED SHOWERS OVER AND NEAR OUR
NORTHERN LARAMIE...SNOWY AND SIERRA MADRE RANGES...WITH MOSTLY DRY
CONDITIONS ELSEWHERE.
SUNDAY NIGHT...MOIST OROGRAPHIC NORTHWEST FLOW ALOFT CONTINUES
PRODUCING SCATTERED TO NUMEROUS SNOW SHOWERS OVER AND NEAR OUR
SNOWY...SIERRA MADRE AND LARAMIE RANGES...DRY ELSEWHERE.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 415 AM MDT SAT APR 18 2015
THE EXTENDED PERIOD WILL START OUT TRANQUIL AND THEN END
POTENTIALLY UNSETTLED. NORTHWESTERLY FLOW ALOFT WILL BE IN PLACE
ON MON WITH A WEAK SHORTWAVE MOVING OVERHEAD DURING THE DAY. COULD
BE SOME LIGHT SNOW SHOWERS OVER THE SIERRA MADRE AND SNOWY
RANGES...BUT MUCH OF THE ACTIVITY WILL BE CONFINED TO NORTHERN
COLORADO. WITH 700MB TEMPS AROUND -6C...IT WILL BE ANOTHER DAY OF
BELOW NORMAL TEMPS. WE FINALLY GET TEMPS TO MODERATE SOME BY TUES
AND ESPECIALLY INTO WED...BACK INTO THE 50S AND 60S TO THE EAST OF
THE LARAMIE RANGE. A BUILDING SFC HIGH OVER THE NORTHERN PLAINS ON
THURS WILL CAUSE SOUTHEAST WINDS TO DEVELOP ACROSS THE PLAINS.
WEAK INSTABILITY WILL BE PRESENT ON THURS AFTN...SO INCLUDED A
SLIGHT OF TSTMS. A SHORTWAVE WILL THEN LIFT NORTHEASTWARD FROM
ARIZONA INTO COLORADO ON FRI. BOTH THE GFS AND ECMWF INDICATE THE
BEST CHANCE OF WIDESPREAD PRECIP COULD BE FRI AFTN INTO FRI NIGHT
WITH GOOD EASTERLY UPSLOPE FLOW OVER THE PLAINS. 700MB TEMPS ARE
AROUND -2C...SO COULD BE DEALING WITH ANOTHER CASE WHERE SNOW IS
LARGELY CONFINED TO AREAS ALONG AND WEST OF THE LARAMIE RANGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 545 AM MDT SAT APR 18 2015
THE LARGE AREA OF LIGHT SNOW IS CURRENTLY ALONG AND JUST WEST OF
THE LARAMIE RANGE AND MOVING WESTWARD. EXPECT IFR CONDITIONS AND LIGHT
SNOW THROUGH MUCH OF THE MORNING TO THE WEST OF THE LARAMIE RANGE.
IFR CIGS ARE EXPECTED THROUGH MID MORNING AT CYS BUT PRECIPITATION
HAS ENDED. MVFR CONDITIONS WILL GENERALLY PREVAIL THROUGH 18Z
OVER THE NEBRASKA PANHANDLE WITH PERIODS OF LIGHT
RAIN...ESPECIALLY OVER THE NORTHERN PANHANDLE. A COLD FRONT WILL
PUSH ACROSS THE PLAINS BY LATE THIS EVENING (AFTER 03Z) WITH
BREEZY NORTH WINDS.
&&
.FIRE WEATHER...
ISSUED AT 402 AM MDT SAT APR 18 2015
NO FIRE WEATHER ISSUES WITH RECENT WIDESPREAD
PRECIPITATION...AND PROJECTED HUMIDITIES AND WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL NOON MDT TODAY FOR WYZ114>117.
WINTER WEATHER ADVISORY UNTIL NOON MDT TODAY FOR WYZ103-105-106-
110-112.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...RUBIN
LONG TERM...ZF
AVIATION...ZF
FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
551 AM MDT SAT APR 18 2015
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 415 AM MDT SAT APR 18 2015
TODAY...SLOW MOVING CLOSED UPPER LOW PROGGED TO MOVE FROM CENTRAL
COLORADO THIS MORNING TO EAST CENTRAL COLORADO BY DINNER TIME. ALL
MODELS INCLUDING THE HRRR SHOW A BAND OF PRECIPITATION SWINGING
WESTWARD ACROSS OUR COUNTIES THIS MORNING AND AFTERNOON WITH DECENT
UPWARD VERTICAL MOTION AND QUASIGEOSTROPHIC FORCING...THUS HAVE
OPTED TO EXTEND OUR WINTER WEATHER ADVISORIES AND WINTER STORM
WARNINGS THROUGH MIDDAY...WHILE DROPPING CHEYENNE FROM THE ADVISORY
WITH TEMPERATURES LIKELY REMAINING ABOVE FREEZING AND THUS MINIMAL
IMPACTS TO TRAVEL.
TONIGHT...FINALLY...THE UPPER TROUGH OPENS UP AS A NORTHERN STREAM
SHORTWAVE TROUGH ALOFT MOVES EASTWARD INTO WESTERN NORTH
DAKOTA...THUS PRECIPITATION CHANCES DWINDLE AS THE NIGHT PROGRESSES.
SUNDAY...BREEZY TO WINDY...AND COOL WITH BRISK NORTHWEST FLOW ALOFT
AND DEEP UNIDIRECTIONAL WINDS. LOOKS LIKE ENOUGH LOW AND MID LEVEL
MOISTURE FOR ISOLATED TO SCATTERED SHOWERS OVER AND NEAR OUR
NORTHERN LARAMIE...SNOWY AND SIERRA MADRE RANGES...WITH MOSTLY DRY
CONDITIONS ELSEWHERE.
SUNDAY NIGHT...MOIST OROGRAPHIC NORTHWEST FLOW ALOFT CONTINUES
PRODUCING SCATTERED TO NUMEROUS SNOW SHOWERS OVER AND NEAR OUR
SNOWY...SIERRA MADRE AND LARAMIE RANGES...DRY ELSEWHERE.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 415 AM MDT SAT APR 18 2015
THE EXTENDED PERIOD WILL START OUT TRANQUIL AND THEN END
POTENTIALLY UNSETTLED. NORTHWESTERLY FLOW ALOFT WILL BE IN PLACE
ON MON WITH A WEAK SHORTWAVE MOVING OVERHEAD DURING THE DAY. COULD
BE SOME LIGHT SNOW SHOWERS OVER THE SIERRA MADRE AND SNOWY
RANGES...BUT MUCH OF THE ACTIVITY WILL BE CONFINED TO NORTHERN
COLORADO. WITH 700MB TEMPS AROUND -6C...IT WILL BE ANOTHER DAY OF
BELOW NORMAL TEMPS. WE FINALLY GET TEMPS TO MODERATE SOME BY TUES
AND ESPECIALLY INTO WED...BACK INTO THE 50S AND 60S TO THE EAST OF
THE LARAMIE RANGE. A BUILDING SFC HIGH OVER THE NORTHERN PLAINS ON
THURS WILL CAUSE SOUTHEAST WINDS TO DEVELOP ACROSS THE PLAINS.
WEAK INSTABILITY WILL BE PRESENT ON THURS AFTN...SO INCLUDED A
SLIGHT OF TSTMS. A SHORTWAVE WILL THEN LIFT NORTHEASTWARD FROM
ARIZONA INTO COLORADO ON FRI. BOTH THE GFS AND ECMWF INDICATE THE
BEST CHANCE OF WIDESPREAD PRECIP COULD BE FRI AFTN INTO FRI NIGHT
WITH GOOD EASTERLY UPSLOPE FLOW OVER THE PLAINS. 700MB TEMPS ARE
AROUND -2C...SO COULD BE DEALING WITH ANOTHER CASE WHERE SNOW IS
LARGELY CONFINED TO AREAS ALONG AND WEST OF THE LARAMIE RANGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 545 AM MDT SAT APR 18 2015
THE LARGE AREA OF LIGHT SNOW IS CURRENTLY ALONG AND JUST WEST OF
THE LARAMIE RANGE AND MOVING WESTWARD. EXPECT IFR CONDITIONS AND LIGHT
SNOW THROUGH MUCH OF THE MORNING TO THE WEST OF THE LARAMIE RANGE.
IFR CIGS ARE EXPECTED THROUGH MID MORNING AT CYS BUT PRECIPITATION
HAS ENDED. MVFR CONDITIONS WILL GENERALLY PREVAIL THROUGH 18Z
OVER THE NEBRASKA PANHANDLE WITH PERIODS OF LIGHT
RAIN...ESPECIALLY OVER THE NORTHERN PANHANDLE. A COLD FRONT WILL
PUSH ACROSS THE PLAINS BY LATE THIS EVENING (AFTER 03Z) WITH
BREEZY NORTH WINDS.
&&
.FIRE WEATHER...
ISSUED AT 402 AM MDT SAT APR 18 2015
NO FIRE WEATHER ISSUES WITH RECENT WIDESPREAD
PRECIPITATION...AND PROJECTED HUMIDITIES AND WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL NOON MDT TODAY FOR WYZ114>117.
WINTER WEATHER ADVISORY UNTIL NOON MDT TODAY FOR WYZ103-105-106-
110-112.
NE...NONE.
&&
$$
SHORT TERM...RUBIN
LONG TERM...ZF
AVIATION...ZF
FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION...DELAYED
NWS CHEYENNE WY
426 AM MDT SAT APR 18 2015
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 415 AM MDT SAT APR 18 2015
TODAY...SLOW MOVING CLOSED UPPER LOW PROGGED TO MOVE FROM CENTRAL
COLORADO THIS MORNING TO EAST CENTRAL COLORADO BY DINNER TIME. ALL
MODELS INCLUDING THE HRRR SHOW A BAND OF PRECIPITATION SWINGING
WESTWARD ACROSS OUR COUNTIES THIS MORNING AND AFTERNOON WITH DECENT
UPWARD VERTICAL MOTION AND QUASIGEOSTROPHIC FORCING...THUS HAVE
OPTED TO EXTEND OUR WINTER WEATHER ADVISORIES AND WINTER STORM
WARNINGS THROUGH MIDDAY...WHILE DROPPING CHEYENNE FROM THE ADVISORY
WITH TEMPERATURES LIKELY REMAINING ABOVE FREEZING AND THUS MINIMAL
IMPACTS TO TRAVEL.
TONIGHT...FINALLY...THE UPPER TROUGH OPENS UP AS A NORTHERN STREAM
SHORTWAVE TROUGH ALOFT MOVES EASTWARD INTO WESTERN NORTH
DAKOTA...THUS PRECIPITATION CHANCES DWINDLE AS THE NIGHT PROGRESSES.
SUNDAY...BREEZY TO WINDY...AND COOL WITH BRISK NORTHWEST FLOW ALOFT
AND DEEP UNIDIRECTIONAL WINDS. LOOKS LIKE ENOUGH LOW AND MID LEVEL
MOISTURE FOR ISOLATED TO SCATTERED SHOWERS OVER AND NEAR OUR
NORTHERN LARAMIE...SNOWY AND SIERRA MADRE RANGES...WITH MOSTLY DRY
CONDITIONS ELSEWHERE.
SUNDAY NIGHT...MOIST OROGRAPHIC NORTHWEST FLOW ALOFT CONTINUES
PRODUCING SCATTERED TO NUMEROUS SNOW SHOWERS OVER AND NEAR OUR
SNOWY...SIERRA MADRE AND LARAMIE RANGES...DRY ELSEWHERE.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 415 AM MDT SAT APR 18 2015
THE EXTENDED PERIOD WILL START OUT TRANQUIL AND THEN END
POTENTIALLY UNSETTLED. NORTHWESTERLY FLOW ALOFT WILL BE IN PLACE
ON MON WITH A WEAK SHORTWAVE MOVING OVERHEAD DURING THE DAY. COULD
BE SOME LIGHT SNOW SHOWERS OVER THE SIERRA MADRE AND SNOWY
RANGES...BUT MUCH OF THE ACTIVITY WILL BE CONFINED TO NORTHERN
COLORADO. WITH 700MB TEMPS AROUND -6C...IT WILL BE ANOTHER DAY OF
BELOW NORMAL TEMPS. WE FINALLY GET TEMPS TO MODERATE SOME BY TUES
AND ESPECIALLY INTO WED...BACK INTO THE 50S AND 60S TO THE EAST OF
THE LARAMIE RANGE. A BUILDING SFC HIGH OVER THE NORTHERN PLAINS ON
THURS WILL CAUSE SOUTHEAST WINDS TO DEVELOP ACROSS THE PLAINS.
WEAK INSTABILITY WILL BE PRESENT ON THURS AFTN...SO INCLUDED A
SLIGHT OF TSTMS. A SHORTWAVE WILL THEN LIFT NORTHEASTWARD FROM
ARIZONA INTO COLORADO ON FRI. BOTH THE GFS AND ECMWF INDICATE THE
BEST CHANCE OF WIDESPREAD PRECIP COULD BE FRI AFTN INTO FRI NIGHT
WITH GOOD EASTERLY UPSLOPE FLOW OVER THE PLAINS. 700MB TEMPS ARE
AROUND -2C...SO COULD BE DEALING WITH ANOTHER CASE WHERE SNOW IS
LARGELY CONFINED TO AREAS ALONG AND WEST OF THE LARAMIE RANGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1155 PM MDT FRI APR 17 2015
WIDESPREAD IFR/LIFR CONDITIONS THROUGH THE MORNING. A LARGE AREA
OF RAIN IS CURRENTLY OVER THE PANHANDLE AND WILL MOVE TO AROUND
THE LARAMIE RANGE BY 12Z. WITH COLDER TEMPS ACROSS WY...EXPECT
LOWER VIS IN LIGHT SNOW. PERIODS OF SNOW WILL BE LIKELY ACROSS WY
THROUGH THE EARLY AFTN.
&&
.FIRE WEATHER...
ISSUED AT 402 AM MDT SAT APR 18 2015
NO FIRE WEATHER ISSUES WITH RECENT WIDESPREAD
PRECIPITATION...AND PROJECTED HUMIDITIES AND WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL NOON MDT TODAY FOR WYZ114>117.
WINTER WEATHER ADVISORY UNTIL NOON MDT TODAY FOR WYZ103-105-106-
110-112.
NE...NONE.
&&
$$
SHORT TERM...RUBIN
LONG TERM...ZF
AVIATION...ZF
FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1115 PM MDT SUN APR 19 2015
.UPDATE...
ISSUED AT 902 PM MDT SUN APR 19 2015
NARROW BANDS OF SHOWERS CONTINUE TO STREAK OFF THE SOUTHEAST MTS AND
INTO THE ADJACENT INTERSTATE 25 CORRIDOR. THESE HAVE BEEN PRETTY
LOCALIZED SO FAR. NEXT WAVE WILL COME IN AFTER MIDNIGHT ASSOC WITH
DISTURBANCE BACK ACROSS UT/WRN CO. 00Z NAM12 LOOKS CONVECTIVELY
CONTAMINATED...AND WENT WITH A BLEND OF THE LATEST
RAP13...HRRR...AND 18Z GFS. STILL SOME DISCREPANCIES BETWEEN EVEN
THESE MODELS...WITH RAP13 AND HRRR PREFERRING A MORE SOUTHERN
TRACK...ACROSS THE SOUTHWEST MOUNTAINS...SANGRES AND WETS AND
SOUTHERN I-25 CORRIDOR. WHILE GFS...AND THE HEAVY HANDED NAM12
TAKE GREATEST QPF TOTALS ACROSS NORTHERN AND CENTRAL CO...ACROSS
THE PIKES PEAK REGION LATE TONIGHT. HAVE TRENDED TOWARDS THE MORE
SOUTHERN TRACK...AND WILL SEE WHAT 00Z GFS RUN GIVES BEFORE MAKING
DRASTIC CHANGES. OVERALL FORECAST TRENDS POPS UPWARDS INTO THE SCT
CATEGORY LATE TONIGHT...WITH POPS TRENDING DOWNWARD FROM WEST TO
EAST MONDAY MORNING. -KT
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 243 PM MDT SUN APR 19 2015
CURRENTLY...THE UPPER TROUGH HAS MOVED WELL EAST INTO EASTERN KS
THIS AFTN...AND STRONG N-NW WINDS ON THE BACKSIDE OF THE SYSTEM HAVE
BEGUN TO MELLOW AS A RESULT. BRISK WINDS WITH GUSTS UP TO 30 MPH
CONTINUE FROM APPROX LHX AND EASTWARD. UNDER INTERMITTENT CLOUD
COVER WITH ABUNDANT CLOUD BREAKS...TEMPS HAVE WARMED INTO THE 40S TO
LOWER 50S FOR MOST LOWER ELEVATIONS LOCATIONS.
TONIGHT AND TOMORROW...NW FLOW ALOFT HAS SETTLED IN AND WILL BE THE
MAIN STORY OVER THE NEXT FEW DAYS. ONE UPPER WAVE IS NEARING THE
STATE...AND IS EXPECTED TO SPARK ISOLATED TO SCATTERED SHOWERS AND
STORMS OVER THE MTS AND NEARBY PLAINS LATE THIS AFTN AND EVE. AS THE
NIGHT PROGRESSES...MODELS INDICATE THAT THIS WAVE WILL CONTINUE
EAST...PROMOTING MORE CONVECTION OVER THE PALMER DVD AND RAMPART
RANGE AFTER MIDNIGHT. THIS WAS A BIT DIFFERENT THAN WHAT WAS IN THE
FORECAST GRIDS...SO INCREASED POPS IN THOSE LOCATIONS. TOMORROW AFTN
SHOWERS AND STORMS ARE FORECAST TO REDEVELOP OVER THE HIGHER TERRAIN
FOLLOWING A MORE DIURNAL CONVECTIVE PATTERN. THE CHALLENGE TONIGHT
WILL BE MIN TEMPS. TEMPS ARE HOVERING NEAR THE FREEZING MARK...AND
WHETHER THEY STAY JUST ABOVE OR DIP BELOW THAT MARK WILL BE
DETERMINED BY CLOUD COVER. THE WINDS ARE ALREADY STARTING TO DIE
DOWN...SO SIGNIFICANT BREAKS IN THE CLOUD COVER WILL ALLOW MORE
EFFICIENT RADIATIONAL COOLING. HAVE OPTED TO NOT ISSUE ANY SORT OF
FREEZE HIGHLIGHT AT THIS TIME SINCE THE OFFICIAL START IS MAY
1...BUT SOME ATTENTION TO OUTDOOR PLANTS MAY BE IN ORDER FOR
TONIGHT. AS FOR TOMORROW...AFTN MAX TEMPS SHOULD BE ON PAR OR A FEW
DEGREES WARMER THAN THOSE RECORDED TODAY. MOORE
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 243 PM MDT SUN APR 19 2015
...BUSY WEATHER PATTERN DURING THIS PERIOD...
WEATHER WILL LIKELY BE A BIT ACTIVE DURING THE EXTENDED PERIOD AS A
FEW DISTURBANCES WILL KEEP AREAS OF PRECIP AND THUNDER OVER THE
REGION. ON FRIDAY...WE MAY SEE SOME ORGANIZED ROTATING CONVECTION
ON THE PLAINS.
MONDAY EVENING A DISTURBANCE WILL BE MOVING ACROSS THE REGION ND
THIS SHOULD ALLOW FOR SOME SCATTERED SHOWERS AND STORMS...MAINLY
ALONG THE CO/NM BORDER DURING THE EVENING.
ON TUESDAY...MIDLVL RIDGE BUILDS TO THE NW OF THE FCST AREA. A WEAK
COOL FRONT IS EXPECTED TO MOVE DOWN THE PLAINS DURING THE DAY AND
THIS MAY ENHANCE THE SHOWER THREAT OVER THE PLAINS TUES
EVENING...ESPECIALLY ALONG THE PLAINS/MTN INTERFACE AND ONCE AGAIN
ALONG THE CO/NM BORDER.
THIS FRONT IS LIKELY GOING TO GET HUNG UP ALONG THE CO/NM BORDER.
THIS WILL KEEP THE PLAINS IN MOIST UPSLOPE FLOW ON WED. ALTHOUGH
FLOW WILL BE RELATIVELY WEAK ALOFT...WE SHOULD SEE ISOLD/SCTD
THUNDER ON THE PLAINS ONCE AGAIN WED AFTERNOON AND EVENING WITH
SOME SHOWERS AND STORMS OVER THE MTNS.
THU AND FRI...
THESE TWO DAYS APPEAR TO BE A BIT MORE ACTIVE AS A WEATHER SYSTEM
MOVES E-NE ACROSS THE SW CONUS AND OVER THE REGION LATER ON
FRIDAY. MOISTURE WILL BE ON THE INCREASE AS REINFORCING COOL
FRONTS WORK SOUTH ALONG THE PLAINS BRINGING UPSLOPE FLOW AND LLVL
MOISTURE. SHEAR AND INSTABILITY WILL BE ON THE INCREASE SO STORMS
THU AFTERNOON MAY BE A BIT STRONGER...AND ON FRIDAY WE MAY SEE
ENOUGH PARAMETERS COME INTO PLAY THAT WE WILL HAVE A ORGANIZED SVR
WEATHER THREAT. OVERALL...THESE TWO DAYS SHOULD BE WET GIVEN THE
FAVORABLE FORCING OVER THE REGION. THIS SYSTEM WILL ALSO LIKELY
BRING MORE HIGH MTN SNOWS...ESPECIALLY TO THE SAN JUANS AND
POSSIBLY SANGRE DE CRISTO MTNS.
FOR THE WEEKEND...MODEST W-NW FLOW ALOFT WILL PREVAIL. GFS HAS A LEE
TROUGH ALONG THE BORDER WHILE EC STILL HAS WEAK UPSLOPE FLOW OVER
THE FCST AREA. WE WILL LIKELY SEE SOME SHOWERS AND STORMS FOR THE
WEEKEND BUT WILL NOT BE AS MANY AS ON THU AND FRI.
AS FOR TEMPS THROUGH THE PERIOD...EXPECT MAX TEMPS ON THE PLAINS
TO RANGE FROM THE MID 60S TO MID 70S. DO NOT EXPECT ANY FIRE WX
ISSUES GIVEN THE RELATIVELY COOL TEMPS AND HIGHER RH AIR OVER THE
DISTRICT. /HODANISH
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1111 PM MDT SUN APR 19 2015
KALS...GENERALLY VFR CONDITIONS UNTIL LATE TONIGHT INTO MONDAY
MORNING AS SHOWERS WILL BE POSSIBLE AROUND THE SAN LUIS VALLEY
LOWERING CIGS AT THE TERMINAL. BREEZY NORTHWEST WINDS ARE EXPECTED
IN THE AFTERNOON WITH MORE WIDESPREAD SHOWER ACTIVITY...MORE
LIKELY TO IMPACT THE TERMINAL...AFTER 20Z.
KCOS...LIGHT PRECIPITATION IS LOWERING CIGS AROUND THE TERMINAL
WITH MODELS INDICATING THE BEST CHANCE FOR SNOW SHOWERS BETWEEN
11-13Z. EXPECT LOWERED CIGS TO CONTINUE INTO MONDAY MORNING BEFORE
IMPROVING THROUGHOUT THE AFTERNOON.
KPUB...A FEW SHOWERS ARE POSSIBLE AROUND THE TERMINAL PRODUCING
LOWERED CIGS TONIGHT...WITH A SMALL WINDOW AROUND 11Z OF SHOWERS
IMPACTING THE TERMINAL. EXPECTED IMPROVING CONDITIONS BY LATE
MORNING INTO MONDAY AFTERNOON. MOZLEY
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KT
SHORT TERM...MOORE
LONG TERM...HODANISH
AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
425 AM EDT MON APR 20 2015
.NEAR TERM [THROUGH TODAY]...
AT 08 UTC, A LARGE CLUSTER OF THUNDERSTORMS WAS BEGINNING TO
DEVELOP UPSTREAM NEAR COASTAL LOUISIANA; THIS WILL LIKELY BE THE
NEXT ROUND OF STORMS TO AFFECT THE AREA LATER THIS MORNING. THE
STORMS WERE DEVELOPING JUST AHEAD OF AN ADVANCING COLD FRONT AND
IN THE LEFT EXIT REGION OF A STRONG 120-140 KNOT UPPER LEVEL JET.
BOTH HI-RES AND GLOBAL MODELS ARE IN GOOD AGREEMENT IN ADVANCING
THIS CONVECTION INTO OUR AREA LARGELY BETWEEN 12 UTC AND 18 UTC,
ALTHOUGH SLIGHT TIMING DIFFERENCES (+/- 2 HOURS) STILL EXIST. THEY
ALSO AGREE THAT THE BULK OF THE CONVECTION WILL BE CONCENTRATED
OVER THE SOUTHERN HALF OF OUR FORECAST AREA - PRIMARILY OUR
FLORIDA ZONES AND PERHAPS THE SOUTHERN ROW OR TWO OF GEORGIA
ZONES. WE ADDED LIKELY POPS OF 60 TO 70 PERCENT IN THOSE AREAS FOR
THE MORNING HOURS. THE QUESTION THEN BECOMES WHAT THE WARM SECTOR
WILL LOOK LIKE THIS AFTERNOON AS THE SYNOPTIC COLD FRONT BEGINS TO
ARRIVE IN OUR AREA. MODELS THAT MAINTAIN SOME INSTABILITY IN THE
NORTHERN HALF OF OUR AREA AFTER THE MORNING ROUND OF CONVECTION
ARE INDICATING MORE AFTERNOON CONVECTION, AS WOULD BE EXPECTED.
THEREFORE, AFTERNOON RAIN CHANCES WILL BE TIED TO HOW THINGS
UNFOLD THIS MORNING. FOR NOW WE PLACED 20 TO 30 PERCENT POPS IN
THE NORTHERN HALF OF OUR AREA THIS AFTERNOON.
THE UPSTREAM STORMS APPEAR TO BE DEVELOPING IN THE CUSP OF A PLUME
OF STEEPER MID-LEVEL LAPSE RATES ASSOCIATED WITH AN ELEVATED MIXED
LAYER, BASED ON THE LATEST RAP ANALYSIS AND 00Z SOUNDINGS FROM THE
WESTERN GULF COAST. AS INCREASING ASCENT LEADS TO SOME MID-LEVEL
COOLING, AND THE EML PROPAGATES EAST, LAPSE RATES SHOULD STEEPEN
ACROSS OUR AREA EARLY THIS MORNING. MODEL FORECAST SOUNDINGS SHOW 7
C/KM 700-500MB LAPSE RATES AT TLH BY 12-15Z. COMBINED WITH THE LOW-
LEVEL MOISTURE IN PLACE ACROSS THE AREA, THIS IS EXPECTED TO
GENERATE CAPE VALUES ON THE ORDER OF 2000-2500 J/KG, WHICH WILL ALSO
COINCIDE WITH 0-6KM BULK SHEAR VALUES AROUND 50 KNOTS. ALL OF THESE
ARE INDICATORS OF A FAVORABLE ENVIRONMENT FOR SEVERE STORMS:
ORGANIZED CONVECTIVE LINES (WHICH SEEMS LIKE IT WILL BE THE DOMINANT
MODE THIS MORNING) OR SUPERCELLS. STRAIGHT-LINE HODOGRAPHS THIS
MORNING WOULD FAVOR SPLITTING SUPERCELLS IF THEY WERE TO OCCUR, AND
IN A HIGHLY SHEARED ENVIRONMENT WITH STEEP LAPSE RATES AND LOW WET-
BULB ZERO HEIGHTS (~8500 FT) LARGE HAIL WOULD BE A GREATER THREAT.
THEREFORE, THIS MORNING WE EXPECT THE MAIN THREATS TO BE ASSOCIATED
WITH LARGE HAIL AND DAMAGING WINDS. IF ISOLATED TO SCATTERED STORMS
CAN DEVELOP IN THE AFTERNOON ALONG THE COLD FRONT, SUPERCELLS WOULD
AGAIN BE POSSIBLE AND GREATER LOW LEVEL SHEAR WOULD MEAN THAT
ISOLATED TORNADOES WOULD ALSO BE A THREAT IN ADDITION TO HAIL AND
WINDS. HOWEVER, NEW CONVECTION MAY BE FIGHTING BOTH DIMINISHED
INSTABILITY AND INCREASINGLY DRY MID-LEVEL AIR WHICH CAN DILUTE
UPDRAFT STRENGTH. THEREFORE, CONFIDENCE IS LOWER FOR BOTH RAIN
CHANCES AND SEVERE WEATHER CHANCES IN THE AFTERNOON.
TO RECAP: MORNING ROUND OF STORMS IS LIKELY - MAINLY SOUTH. SOME OF
THOSE MAY BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS. THE
COMBINATION OF STRONG INSTABILITY AND STRONG SHEAR IS A BIT UNUSUAL,
SO A SIGNIFICANT SEVERE REPORT OR TWO CAN`T BE RULED OUT. IN THE
AFTERNOON, ISOLATED STORMS MAY REDEVELOP - ESPECIALLY NORTH. THE
CHANCES OF SEVERE WEATHER MAY BE LOWER AFTER 18 UTC.
.SHORT TERM [TONIGHT THROUGH WEDNESDAY]...
THE SEVERE THREAT SHOULD PRETTY MUCH BE OVER BY TONIGHT WITH JUST
SOME ISOLATED TO SCATTERED SHOWERS AND STORMS OVER OUR EASTERN ZONES
UNTIL AROUND MIDNIGHT. WE WILL THEN FINALLY COME UNDER THE INFLUENCE
OF SURFACE HIGH PRESSURE WHICH WILL BRING US A RARE TWO-DAY STRETCH
WITHOUT APPRECIABLE POPS, AND SOME SUNSHINE AND LOWER HUMIDITY TO
BOOT. TEMPERATURES WILL BE MUCH CLOSER TO SEASONAL LEVELS AS WELL,
ESPECIALLY AT NIGHT.
.LONG TERM [WEDNESDAY NIGHT THROUGH MONDAY]...
RAIN CHANCES AND NIGHTTIME TEMPERATURES WILL GRADUALLY CREEP UP ONCE
AGAIN AS SURFACE HIGH PRESSURE MOVES EAST OF THE AREA AND OUR FLOW
BECOMES ONSHORE ONCE AGAIN. DAYTIME HIGHS WILL GENERALLY BE IN THE
LOWER 80S. THE SOUTHERN BRANCH OF THE JET WILL CONTINUE TO PULL
IMPULSES OF ENERGY ACROSS THE REGION AS A SURFACE FRONT SETS UP JUST
NORTH OF THE REGION, OCCASIONALLY DIPPING INTO OUR NORTHERN ZONES.
THESE FEATURES AND THE SEA BREEZE WILL GENERATED SCATTERED
THUNDERSTORMS EACH DAY. SHEAR AND INSTABILITY LOOK SUFFICIENT FOR
SOME SOME STRONG STORMS ON THURSDAY WITH SEVERE STORMS POSSIBLE
FRIDAY AND SATURDAY.
&&
.AVIATION...
[THROUGH 06Z TUESDAY] SOME LOW CIGS AND PATCHY FOG WILL BE POSSIBLE
THIS MORNING AT ALL TERMINAL SITES WITH IFR CONDITIONS LIKELY FOR A
TIME AND LIFR POSSIBLE. CONDITIONS SHOULD IMPROVE TO MVFR-VFR AFTER
ABOUT 14-15 UTC OVERALL. HOWEVER, TEMPORARY VIS RESTRICTIONS IN
THUNDERSTORMS WILL BE POSSIBLE. ONE ROUND OF STORMS WILL MOVE IN
DURING THE MORNING HOURS - REACHING ECP AROUND 13 UTC, TLH AROUND 15
UTC, AND VLD AROUND 16 UTC (+/- 2 HOURS AT EACH SITE). SOME OF THESE
STORMS COULD BE QUITE STRONG AND PRODUCE HAIL OR BRIEF GUSTS IN
EXCESS OF 30 KNOTS. ISOLATED STORMS MAY REDEVELOP IN THE AFTERNOON,
AFFECTING MAINLY DHN AND ABY.
&&
.MARINE...
STRONG TO SEVERE STORMS WILL BE POSSIBLE TODAY ACROSS THE WATERS.
EVEN OUTSIDE OF THUNDERSTORMS, WINDS ARE EXPECTED TO REACH
CAUTIONARY LEVELS AT TIMES TODAY AND TONIGHT BEFORE DIMINISHING ON
TUESDAY AS HIGH PRESSURE MOVES EAST ALONG THE COAST. THIS HIGH WILL
THEN MOVE OFF THE EAST COAST OF FLORIDA AND BRING A PERIOD OF LIGHT
ONSHORE WINDS FROM WEDNESDAY THROUGH FRIDAY.
&&
.FIRE WEATHER...
WETTING RAINS ARE EXPECTED TODAY ACROSS PRIMARILY THE SOUTHERN HALF
OF THE AREA (FLORIDA ZONES AND THE SOUTHERN ROW OF ZONES IN
GEORGIA). RH WILL STAY ABOVE 60 PERCENT IN MOST AREAS. DRIER AIR
WILL ARRIVE TOMORROW, BUT IT SHOULD NOT BE SUFFICIENTLY DRY FOR RED
FLAG CONDITIONS AND FUEL MOISTURES SHOULD STILL BE HIGH. RAIN
CHANCES AND HIGHER RH RETURN BY THURSDAY.
&&
.HYDROLOGY...
MINOR FLOODING IS OCCURRING ALONG PARTS OF THE CHOCTAWHATCHEE RIVER
AND IS EXPECTED TO CONTINUE. BRUCE IS FORECAST TO EVENTUALLY REACH
MODERATE FLOOD STAGE IN A COUPLE OF DAYS, ALBEIT JUST BARELY. MINOR
FLOODING IS ALSO OCCURRING ON THE KINCHAFOONEE CREEK AT DAWSON. THE
APALACHICOLA RIVER AT BLOUNTSTOWN IS NOW FORECAST TO CREST JUST
BARELY BELOW FLOOD STAGE, BUT THAT COULD QUICKLY CHANGE IF MORE RAIN
FALLS IN THE BASIN THAN THE CURRENTLY PREDICTED HALF INCH FOR
TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TALLAHASSEE 81 62 82 57 85 / 70 20 10 10 10
PANAMA CITY 78 63 76 63 79 / 70 10 0 10 10
DOTHAN 78 57 77 56 81 / 30 10 0 10 10
ALBANY 78 58 78 55 82 / 50 10 0 10 10
VALDOSTA 80 61 79 55 84 / 60 20 10 10 10
CROSS CITY 83 64 82 58 84 / 70 30 10 10 10
APALACHICOLA 79 65 79 63 81 / 70 20 10 10 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH LATE TONIGHT FOR COASTAL BAY-
COASTAL GULF-SOUTH WALTON.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...LAMERS
SHORT TERM...WOOL
LONG TERM...WOOL
AVIATION...LAMERS
MARINE...WOOL
FIRE WEATHER...WOOL
HYDROLOGY...WOOL
AREA FORECAST DISCUSSION
NWS LINCOLN IL
313 AM CDT MON APR 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT MON APR 20 2015
07Z/2AM WATER VAPOR IMAGERY SHOWS LONG-WAVE TROUGH AXIS EXTENDING
FROM MINNESOTA TO NORTHERN TEXAS, WITH VIGOROUS SHORT-WAVE NOTED ON
ITS EAST SIDE OVER SOUTHEAST MISSOURI. WITH MAIN WAVE STILL TO THE
WEST, SCATTERED SHOWERS ARE ONGOING ACROSS CENTRAL ILLINOIS EARLY
THIS MORNING. AS SOUTHEAST MISSOURI WAVE TRACKS INTO THE OHIO RIVER
VALLEY, THINK AREAL COVERAGE OF SHOWERS WILL DIMINISH AFTER SUNRISE,
WITH LITTLE OR NO PRECIP OCCURRING FOR THE BALANCE OF THE MORNING.
DESPITE LOW-LEVEL DRYING IN THE WAKE OF THIS FEATURE, SYNOPTIC-SCALE
CYCLONIC FLOW ALOFT WILL LEAD TO STEEP LAPSE RATES AND PERHAPS A FEW
SHOWERS FROM LATE MORNING INTO THE AFTERNOON. MOST MODEL GUIDANCE
REMAINS DRY: HOWEVER, BOTH THE HRRR AND 4KM WRF-NMM SUGGEST AT LEAST
ISOLATED SHOWERS AS THE ATMOSPHERE DESTABILIZES. WILL CARRY SLIGHT
CHANCE POPS ACROSS THE BOARD TO COVER THIS POSSIBILITY. COLD FRONT
CURRENTLY APPROACHING THE I-55 CORRIDOR WILL SWEEP EASTWARD THIS
MORNING AND EXIT INTO INDIANA BY MIDDAY. STRONG/GUSTY WINDS WILL
DEVELOP BEHIND THE FRONT AS PRESSURE GRADIENT TIGHTENS. LATEST OBS
ARE ALREADY SHOWING GUSTS IN THE 25 TO 30MPH RANGE AND THINK MIXING
OF HIGHER MOMENTUM AIR ALOFT WILL RESULT IN GUSTS OF 30 TO 35MPH
DURING THE DAY. HIGH TEMPERATURES WILL BE IN THE UPPER 50S AND
LOWER 60S.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 AM CDT MON APR 20 2015
A COOL AND MOSTLY DRY WEEK IS ON TAP ACROSS CENTRAL ILLINOIS, WITH
THE NEXT SIGNIFICANT CHANCE FOR RAIN LIKELY HOLDING OFF UNTIL NEXT
WEEKEND. A DEEP UPPER LOW OVER THE GREAT LAKES WILL BE THE DOMINANT
WEATHER FEATURE EARLY IN THE PERIOD, KEEPING THE MIDWEST LOCKED IN A
NORTHWESTERLY FLOW PATTERN. THANKS TO A TIGHTENING PRESSURE
GRADIENT AHEAD OF AN APPROACHING COLD FRONT, STRONG WESTERLY WINDS
WILL ONCE AGAIN DEVELOP ON TUESDAY. NUMERIC GUIDANCE AND FORECAST
SOUNDINGS BOTH SUGGEST GUSTS REACHING 30 TO 35MPH AT TIMES. THE
FRONT WILL PASS THROUGH THE AREA TUESDAY NIGHT INTO WEDNESDAY
MORNING: HOWEVER, DEEP-LAYER MOISTURE WILL BE LACKING, SO PRECIP
CHANCES WILL REMAIN NEGLIGIBLE. WILL ONLY CARRY LOW CHANCE POPS
ACROSS THE SOUTHERN KILX CWA AS THE FRONT PASSES. AN EVEN COOLER
AIRMASS WILL ARRIVE FOR THE MIDDLE AND END OF THE WEEK BEHIND THE
DEPARTING FRONT, WITH HIGHS DROPPING INTO THE UPPER 50S/LOWER 60S
FOR WEDNESDAY THROUGH FRIDAY. OVERNIGHT LOWS WILL DIP INTO THE 30S,
WITH THE BEST POTENTIAL FOR FROST LIKELY SETTING UP FOR WEDNESDAY
NIGHT AND THURSDAY NIGHT AS SKIES REMAIN CLEAR AND WINDS DIMINISH.
FURTHER OUT, MAJOR MODEL DISCREPANCIES HAVE DEVELOPED CONCERNING THE
NEXT POTENTIAL SYSTEM FOR THE END OF THE WEEK. THE 00Z APR 20 GFS
HAS MADE A MAJOR SHIFT FROM ITS PREVIOUS RUNS AND NOW SHOWS RAIN
SPREADING INTO CENTRAL ILLINOIS FROM AN APPROACHING UPPER LOW AS
EARLY AS FRIDAY. MEANWHILE, BOTH THE ECMWF AND GEM ARE MUCH SLOWER,
WITH RAIN NOT ARRIVING UNTIL LATE FRIDAY NIGHT INTO SATURDAY. GIVEN
INITIAL PRESENCE OF A STRONG RIDGE AXIS ACROSS THE MIDWEST, THINK
THE RAPID PROGRESSION OF RAIN INTO THE DRY AIRMASS SEEMS SUSPECT.
IN ADDITION, THE SLOWER ECMWF/GEM HAVE MAINTAINED GOOD CONSISTENCY
WITH THEIR EARLIER RUNS. AS A RESULT, HAVE REJECTED THE GFS IN
FAVOR OF THE ECMWF/GEM CONSENSUS FOR THE END OF THE WEEK. HAVE
THEREFORE KEPT FRIDAY DRY, THEN HAVE INTRODUCED POPS MAINLY ACROSS
THE CENTRAL AND SOUTHERN CWA FRIDAY NIGHT INTO SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1146 PM CDT SUN APR 19 2015
COLD FRONT FROM AROUND KGBG-KIJX THIS EVENING WILL CROSS CENTRAL
IL TERMINALS THROUGH 10Z CAUSING A FEW SHOWERS AND BRINGING AN
INCREASE IN WESTERLY WINDS. A MIX OF IFR/LIFR CEILINGS AND MAINLY
MVFR VSBYS IN BR WILL GRADUALLY IMPROVE AFTER FRONTAL
PASSAGE...WITH GENERALLY VFR CONDITIONS BY AROUND 14Z. WINDS
INCREASING TO W 15-20 KTS WITH GUSTS UP TO 30 KTS LATE MORNING
THROUGH AFTERNOON. WINDS AND GUSTS DECREASING AFTER 00Z TUESDAY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
104 AM CDT MON APR 20 2015
.UPDATE...809 PM CDT
STEADY RAIN WILL CONTINUE MUCH OF THE EVENING ACROSS NORTHERN
ILLINOIS. MID-LEVEL DRY SLOT WILL PIVOT ACROSS EAST-CENTRAL
ILLINOIS AND NORTHWEST INDIANA THIS EVENING WITH RAIN TAPERING TO
A LIGHT DRIZZLE FOR THESE AREAS...BEFORE SHOWERS SPREAD BACK IN
FROM THE WEST OVERNIGHT. ADDED PATCHY FOG TO THE GRIDS THIS
EVENING AND TONIGHT AS SATURATED TO NEAR SATURATED CONDITIONS ARE
IN PLACE THIS EVENING. SUSPECT VISIBILITY WILL BEGIN TO IMPROVE AS
WEST WINDS INCREASE AFTER MIDNIGHT TONIGHT.
BMD
&&
.SHORT TERM...
319 PM CDT
THROUGH MONDAY NIGHT...
AFTER ANOTHER WARM EARLY AFTERNOON ACROSS MUCH OF THE REGION RAIN IS
BEGINNING TO SPREAD NORTHWARD ACROSS SOUTHERN SECTIONS OF THE CHICAGO
METRO AREA AS OF THIS WRITING. THIS ACTIVITY WILL CONTINUE TO
OVERSPREAD THE REGION THROUGH THE AFTERNOON AND EVENING...WITH
TEMPERATURES LIKELY TO DROP BACK INTO THE UPPER 50S AND LOW 60S IN
THE RAIN.
THE MID-LEVEL DISTURBANCE...AND THE ASSOCIATED SURFACE SYSTEM WILL
QUICKLY SHIFT NORTHWARD OVER LOWER MICHIGAN OVERNIGHT...AND IT
APPEARS THAT THE RAIN WILL BECOME MORE SHOWERY AND INTERMITTENT OR
POSSIBLY JUST SOME DRIZZLE LATER THIS EVENING AND INTO THE EARLY
MORNING ACROSS MUCH OF THE AREA AS THIS INITIAL MID LEVEL
DISTURBANCE SHIFTS NORTH OF THE AREA AND SOME DRIER MID LEVEL AIR
SHIFTS OVER THE SOUTHEASTERN HALF OF MY AREA. SOME ADDITIONAL RAIN
SHOWERS ARE POSSIBLE AGAIN EARLY MONDAY WITHIN A REGION OF MID LEVEL
DEFORMATION AND RAP AROUND MOISTURE ASSOCIATED WITH THE DEEPENING
LOWER AND MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION AND
SOUTHERN CANADA.
CONDITIONS SHOULD DRY OUT MONDAY AFTERNOON...WITH ONLY A SMALL
CHANCE OF AN ADDITIONAL SHOWER DEVELOPING AS COLDER AIR ALOFT
STEEPENS THE LOWER LEVEL LAPSE RATES. THE MAIN STORY DURING THE
AFTERNOON WILL BE THE WINDS. WINDS ARE EXPECTED TO INCREASE OUT OF
THE WEST-NORTHWEST DURING THE DAY AS STOUT SURFACE PRESSURE
GRADIENT SETS UP OVER THE REGION AS THE SURFACE LOW DEEPENS TO
AROUND 985 MB ACROSS ONTARIO MONDAY AFTERNOON. MODEL SOUNDINGS
SUGGEST GOOD AFTERNOON MIXING TO AROUND 850 MB SHOULD ALLOW FOR
GUSTS OF AROUND 30 KT AT TIMES...ESPECIALLY DURING THE AFTERNOON.
THESE WIND GUSTS SHOULD ABATE MONDAY EVENING...BUT STRONG WINDS
LOOK TO DEVELOP AGAIN ON TUESDAY. SEE LONG TERM DISCUSSION FOR
MORE INFO ON TUESDAY`S WINDS.
KJB
&&
.LONG TERM...
319 PM CDT
TUESDAY THROUGH SUNDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH BELOW NORMAL TEMPS
THROUGH THE FORECAST.
LARGE UPPER LEVEL CENTER WILL BE CENTERED ACROSS THE REGION AT THE
START OF THE PERIOD...AND REMAIN SITUATED THROUGH MUCH OF THE WORK
WEEK AS IT SLOWLY MOVES EAST. SEVERAL VORT LOBES ARE ANTICIPATED TO
WRAP AROUND THIS UPPER LEVEL LOW ON TUESDAY AND WITH STEEPENING
LAPSE RATES...EXPECT SKY COVER TO INCREASE THROUGH THE DAY WHILE
SCATTERED SHOWERS BECOME POSSIBLE...ESPECIALLY ACROSS NORTHERN
ILLINOIS. AS THIS OCCURS...LIKELY DEEP MIXING WITH STRONG FLOW ALOFT
WILL ALLOW FOR ANOTHER WINDY DAY. GUIDANCE IS SUGGESTING THAT
ADVISORY CONDITIONS COULD BE REACHED IN THE AFTERNOON...AND WILL
NEED TO CONTINUE MONITORING THIS POTENTIAL. ANY REMAINING PRECIP AND
CLOUD COVER SHOULD EXIT THE AREA TUESDAY NIGHT WITH DRY CONDITIONS
EXPECTED. SOME GUIDANCE DEVELOPS A SWATH OF PRECIP OVER THE CWA LATE
IN THE NIGHT INTO EARLY WEDNESDAY. HOWEVER...A MORE LIKELY SCENARIO
AT THIS TIME WOULD BE FOR DRY CONDITIONS AND SO HAVE LEFT OUT ANY
POPS AT THIS TIME. ONGOING CAA WILL MAKE FOR CHILLY CONDITIONS
TUESDAY NIGHT...WITH LOW TEMPS IN THE 30S. IF PRECIP WERE TO OCCUR
DURING THIS PERIOD...THESE COLDER CONDITIONS COULD SUPPORT THE
POTENTIAL FOR AT LEAST A RAIN SNOW MIX ACROSS NORTHERN ILLINOIS.
EXPECT DRY CONDITIONS WITH BELOW NORMAL TEMPS THROUGH THE REST OF
THE FORECAST PERIOD...WITH FORECAST HIGHS IN THE 50S. COLD NIGHT
TIME LOWS IN THE 30S COULD BECOME AN ISSUE LATE IN THE WORK WEEK AS
HIGH PRESSURE IS ANTICIPATED TO MOVE OVERHEAD...WITH LIGHTER WINDS
AND THE COLD TEMPS POSSIBLY CREATING A SETUP FOR FROST.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WINDS BACKING NORTHWEST LATE THIS EVENING.
* A PERIOD OF SHOWERS MONDAY MORNING.
* LIFR CIGS LASTING INTO OVERNIGHT WITH SLOW IMPROVEMENT DURING
THE DAYBREAK TIME.
* MVFR VISIBILITY THROUGH THE EARLY MORNING HOURS.
* GUSTY WEST WINDS DEVELOPING MONDAY MORNING WITH MAX GUSTS ARND
30 KT LATE MONDAY MORNING AND AFTERNOON.
KMD
//DISCUSSION...UPDATED 06Z...
IFR/LIFR CIGS ARE COMMON ACROSS THE AREA ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW. VSBYS HAVE NOT DIPPED TOO FAR...HOLDING
AT 3-4SM AND LARGELY BETTER THAN THAT IN MOST AREAS THE LOW
CONTINUES NORTHEAST...EXPECT WINDS TO VEER TO SW. NOT EXPECTING
VSBYS TO DROP MUCH FURTHER AS WINDS STAY UP TONIGHT...THOUGH IFR
VSBYS ARE SLIGHTLY POSIBLE...BUT CIGS ARE EXPECTED TO HOLD IN THE
LIFR/IFR CATEGORY DUE TO A LOW LEVEL MOIST AXIS EXTENDING ACROSS
INTO IOWA.
A COLD FRONT WILL ADVANCE EAST TOWARD THE TERMINALS MONDAY
MORNING. TIME HEIGHTS SUGGSEST A GRADUAL LIFT IN CIGS BACK INTO
MVFR AFTER DAYBREAK...BUT A DIMINISHING TREND IN THE TRACKING OF
SHOWERS ACROSS THE TERMINALS THIS MORNING HAS BEEN SEEN IN LATEST
HI-RES MODEL RUNS. SO THE PERIOD OF -SHRA MENTIONED IN THE TAFS
MAY BE A BIT OVERDONE IN THE LENGTH OF TIME. OF MORE CONCERN ARE
THE WESTERLY WINDS THAT WILL GUSTS INTO THE 20S AND POSSIBLY NEAR
30 KT BEHIND THE COLD FRONT THAT WILL MOVE THROUGH DURING THE
LATTER HALF OF MORNING PUSH.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH IN WIND DIRECTION THROUGH THE TAF. MEDIUM-HIGH IN SPEED.
* HIGH IN RAIN INITIAL TIMING THOUGH LOW IN DURATION.
* HIGH IN CIGS AND DURATION. MEDIUM IN CIGS ONLY DROPPING AS FAR
AS 400-500FT.
* MEDIUM IN VISIBILITY TRENDS AND VISIBILITY DROPPING NO MORE THAN
TO 3SM.
* MEDIUM IN CIGS/VISBYS AND SHRA DURING THE MORNING RUSH ON
MONDAY.
KMD
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...SLIGHT CHANCE OF SHRA AND MVFR. GUSTY WEST WINDS.
WEDNESDAY-THURSDAY...VFR. NORTHWEST WINDS.
FRIDAY-SATURDAY...VFR. WINDS BECOMING NORTHEAST.
MTF
&&
.MARINE...
324 PM CDT
AS A TROUGH OF LOW PRESSURE AND SECONDARY LOW PRESSURE CENTER
MOVE ACROSS THE GREAT LAKES REGION TONIGHT...WINDS WILL LIKELY BE
VARIABLE AT TIMES. THIS WILL ESPECIALLY BE THE CASE OVER THE
SOUTHERN HALF OF THE LAKE WHERE THE LOW PRESSURE SYSTEM IS
EXPECTED TO MOVE THROUGH. IN THE NEAR TERM...EAST NORTHEAST WINDS
WILL PREVAIL OVER THE LAKE WITH THE HIGHEST SPEEDS TO 30 KT
OCCURRING OVER THE NORTHERN HALF AND WHILE 15 TO 25 KT WINDS ARE
BEING OBSERVED OVER THE SOUTH...WITH SPEEDS EXPECTED TO SLIGHTLY
DIMINISH TONIGHT. AS THIS TROUGH/LOW EXIT TO THE EAST ON
MONDAY...STRONGER WESTERLY WINDS WILL DEVELOP. HIGHEST WINDS TO 30
KT WILL OCCUR ALONG THE NEARSHORE WATERS WHILE ONLY 15 TO 25 KT
ARE LIKELY OVER THE OPEN WATERS. A SIMILAR SETUP IS EXPECTED ON
TUESDAY BUT WITH SPEEDS SLIGHTLY HIGHER...AS TO 30 KT WILL LIKELY
PREVAIL FOR BOTH LOCATIONS AND WITH EVEN GALES POSSIBLE ALONG THE
NEARSHORE WATERS DURING THE DAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...11 AM MONDAY TO 9 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...CORRECTED TYPO IN FIRST PARAGRAPH OF LONG TERM
NWS QUAD CITIES IA IL
346 AM CDT MON APR 20 2015
.SYNOPSIS...
ISSUED AT 335 AM CDT MON APR 20 2015
DEEPENING CYCLONE (987 MB) WAS LOCATED IN EXTREME WESTERN LOWER MI
AND BROUGHT WIDESPREAD RAIN TO THE DVN CWA LAST EVENING AND OVERNIGHT.
A COLD FRONT HAS SWEPT THROUGH THE AREA WITH NORTHWEST WINDS GUSTING
TO 35 MPH. DOPPLER RADAR INDICATED LIGHT RAIN STILL FALLING ROUGHLY
ALONG AND NORTH OF HIGHWAY 30 IN IA AND IL AND WAS GRADUALLY LIFTING
NORTHWARD. CURRENT TEMPERATURES RANGED FROM THE LOWER 40S TO MID 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT MON APR 20 2015
FORECAST FOCUS ON RAIN CHANCES...WIND AND TEMPERATURES.
TODAY...THIS WILL BE A VERY WINDY AND MUCH COOLER DAY AS THE DEEPENING
CYCLONE TRACKS NORTHWARD TO JUST NORTH OF LAKE SUPERIOR. THE STRATIFORM
RAIN SHIELD SHOULD LIFT OUT OF THE DVN CWA BY MID TO LATE MORNING.
OTHERWISE PARTLY SUNNY SKIES ARE EXPECTED WITH FORECAST SOUNDINGS
INDICATING DEEP MIXING TO ABOUT 700 MB BRINGING DOWN 35 TO 40 MPH
WIND GUSTS...WHICH IS BELOW ADVISORY CRITERIA. NONETHELESS HANG ONTO
YOUR HAT AND THE STEERING WHEEL! STEEP LAPSE RATES AND ENOUGH MOISTURE
SHOULD ALLOW FOR ISOLATED HIGH-BASED RAIN SHOWERS ANYWHERE IN THE CWA
LATER THIS MORNING THROUGH THE AFTERNOON. THE HRRR AND WRF MODELS DEPICT
THIS SCENARIO QUITE WELL. TEMPERATURES WILL BE A CHALLENGE AGAIN AS
WE HAVE COLD AIR ADVECTION BUT THERE WILL ALSO BE SOME SUNSHINE TO
OFFSET THIS SOMEWHAT. THEREFORE A GOOD COMPROMISE SEEMS TO BE HIGHS
IN THE UPPER 50S TO LOWER 60S.
TONIGHT...DEEP CYCLONE (980 MB) WILL BE ANCHORED NORTH OF LAKE SUPERIOR
DUE TO A STRONG GREENLAND BLOCK. SKIES SHOULD BE PARTLY CLOUDY AND GUSTY
WEST WINDS WILL DIMINISH BY SUNSET WITH DECOUPLING. HOWEVER... THE WINDS
SHOULD STAY AT 10 TO 15 MPH MUCH OF THE NIGHT. MINIMUM TEMPERATURES
IN THE 35 TO 40 RANGE SHOULD BE COMMON. A FEW SHOWERS MAY LINGER INTO
THE EARLY EVENING HOURS FOR LATER SHIFTS TO CONSIDER...BUT FOR NOW I
WILL CONTINUE A DRY FORECAST FOR TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 AM CDT MON APR 20 2015
SEASONABLY COOL AND MAINLY DRY FOR MUCH OF THE WEEK WITH FROST/FREEZE
POTENTIAL LATER IN THE WEEK.
NORTHWEST FLOW PATTERN WILL GOVERN MUCH OF THE LONG TERM PERIOD AS
BLOCKING DEVELOPS OVER EASTERN ATLANTIC AND GREENLAND RESULTING IN
SLOW EASTWARD PROGRESSION OF GREAT LAKES UPPER LOW. SERIES OF
IMPULSES WILL ROTATE AROUND THE CYCLONE WITH NORTHERN CWA IN CLOSER
PROXIMITY AND THUS FAVORED FOR MORE DIURNAL DRIVEN CLOUD COVER ON
TUESDAY ALONG WITH SPRINKLES AND SOME LIGHT POPCORN SHOWERS GIVEN
STEEP LAPSE RATES...COLD AIR ALOFT AND PRESENCE OF SKINNY CAPE NOTED
ON FORECAST SOUNDINGS. MAIN ITEM ON TUESDAY WILL BE WINDY CONDITIONS
WITH POTENTIAL FOR WIND ADVISORY AS NAM/GFS BUFR SOUNDINGS SHOWING
30-35 KTS OF WIND ON AVERAGE THROUGH THE MIXED LAYER WITH 50-55 KTS
SITTING ATOP DEEP MIXED LAYER TO NEAR 650 MB. POSSIBLE AS WELL THAT
ANY SHOWERS COULD ENHANCE WIND GUSTS VIA EVAPORATIVE COOLING OF
PCPN IN LARGE... DRY SUB-CLOUD LAYER WITH CLASSIC INVERTED V TYPE
SOUNDINGS.
CANADIAN SURFACE RIDGE AXIS WILL BUILD IN OVER THE LATTER HALF OF THE
WEEK AS THE UPPER LOW PLODS EASTWARD FROM GREAT LAKES. THIS WILL
BRING DIMINISHING WINDS WEDNESDAY THROUGH FRIDAY BUT ALSO REINFORCE
COOL... DRY AIR WITH MORE IDEAL RADIATIONAL COOLING SETUP LEADING TO
INCREASING RISK FOR AREAS OF FROST AND FREEZING TEMPS POSSIBLY AS
EARLY AS WEDNESDAY AM... BUT MORE LIKELY THURSDAY/FRIDAY AM. FREEZE
HIGHLIGHTS ARE ACTIVE IF NEEDED WITH FRUIT TREES NOW SUSCEPTIBLE
TO TEMPS AT/BELOW 28F PER FEEDBACK FROM ISU EXTENSION COMMERCIAL
HORTICULTURE SPECIALIST. NURSERIES AND STORES ALSO MOVING
STOCK OUTDOORS... AND RECENT WARM SPELL AND MOISTURE HAS CAUSED YARDS
TO ADVANCE QUICKLY.
TOWARD SATURDAY AND INTO THE FIRST HALF OF THE WEEKEND THERE IS THE
POTENTIAL FOR RAIN CHANCES WITH ANOTHER STORM SYSTEM. CONFIDENCE IS
LOW AS MODEL VARIANCE QUITE HIGH. DPROG/DT... OR COMPARISON OF MODELS
RUN TO RUN... SHOWS BETTER CONSISTENCY EXISTS WITH ECMWF WHICH IS
SLOWER AND FAVORS SOUTHERN CWA FOR BETTER RAIN CHANCES DUE TO MORE
SOUTHERLY TRACK OF SYSTEM AND INCREASING EASTERLY FLOW. GFS ENSEMBLE
MEANS SIMILAR LINES OF ECMWF AND ACTUALLY SUGGEST MUCH IF NOT ALL OF
RAIN STAYING TO OUR SOUTH FROM PARTS OF MID TO LOWER MISSISSIPPI VLY
WHICH ALSO FITS WITH PATTERN OF LATE. AS RESULT... HAVE ADJUSTED POPS
TO LOWER OR REMOVE ACROSS THE NORTH/EAST FRIDAY NIGHT AND SATURDAY AND
PLACE THE BEST CHANCES ACROSS THE SOUTHERN CWA.
TEMPS THROUGHOUT THE ENTIRE PERIOD LOOK TO REMAIN SEASONABLY COOL WITH
HIGHS 50S/60S... AND LOWS MAINLY IN THE 30S WITH SOME 20S IN FAVORED
DRAINAGE LOCATIONS WEDNESDAY THROUGH FRIDAY MORNINGS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1131 PM CDT SUN APR 19 2015
COMPLEX STORM SYSTEM CONTINUES PROGRESSING ACROSS THE MIDWEST AND
PRODUCING WIDESPREAD RAIN WITH IFR-MVFR CIGS AND VSBYS IN EASTERN
IOWA AND NORTHWEST ILLINOIS. THE SYSTEM SHOULD BEGIN EXITING THE
REGION TOWARD SUNRISE. MEANWHILE A SURFACE COLD FRONT ASSOCIATED
WITH THE SYSTEM HAS REACHED ROUGHLY ALONG THE MISSISSIPPI RIVER
AT 04Z. VERY STRONG AND GUSTY NORTHWEST WINDS ARE FOLLOWING THE
FRONT AND WILL CONTINUE MONDAY. WHILE VFR CONDITIONS ARE ON TAP
MONDAY...SCATTERED AFTERNOON INSTABILITY SHOWERS MAY DEVELOP
CAUSING LOCALIZED MVFR VSBYS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...MCCLURE
AVIATION...WOLF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
333 AM EDT MON APR 20 2015
.SYNOPSIS...
WIDESPREAD RAIN WILL DEVELOP OVER OUR AREA LATER TONIGHT INTO
EARLY MONDAY AS A STORM SYSTEM MOVES THROUGH THE GREAT LAKES.
AFTER A BRIEF LULL IN RAIN MIDDAY MONDAY, ANOTHER ROUND OF SHOWERS
IS POSSIBLE MONDAY AFTERNOON AND EVENING. DURING THAT TIME
SCATTERED THUNDERSTORMS ARE POSSIBLE. WE WILL REMAIN UNSETTLED AND
VERY COOL THE REST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
940 PM UPDATE...
TIMING OF RAINFALL LOOKS TO BE ON TRACK. I TWEAKED THE OVERNIGHT
WIND GRIDS A BIT. WE STILL HAVE GUSTS OVER 40 MPH ON THE HILLTOPS
ABOVE 1500 FEET. I INCREASED WIND IN THE LAKE PLAIN, SHOWING SOME
GUSTS IN THE LOWER 30S AT KSYR. RUC SOUNDINGS SEEM A BIT LOW HERE
GIVEN FAVORABLE SOUTHEAST DOWNSLOPING AND MAV GUIDANCE SHOWING
SUSTAINED WINDS IN THE LOWER 20S. OTHERWISE PREVIOUS AFD IS
BELOW...
300 PM UPDATE...
A BEAUTIFUL END TO OUR WEEKEND ALBEIT A GOOD 10 DEGREES OR SO
COOLER THAN YESTERDAY AFTERNOON. I HOPE YOU ENJOYED THE WEEKEND
BECAUSE THE WEATHER THROUGH THE END OF THE MONTH DOESN`T LOOK ALL
THAT GOOD.
WE ARE ALREADY SEEING SIGNS OF THOSE CHANGES IN THE FORM OF SOME
THIN WISPY HIGH CLOUDS. THESE ARE WELL AHEAD OF AN AREA OF LOW
PRESSURE NOW OVER ILLINOIS THAT WILL TRACK THROUGH THE GREAT
LAKES MONDAY. A LARGE SHIELD OF RAIN WELL AHEAD OF A WARM FRONT
WITH THIS SYSTEM WILL MOVE IN TONIGHT. NOT EXPECTING ANY HYDRO
ISSUES BUT A QUICK SHOT OF STEADY RAIN IS LIKELY FOR EVERYONE.
THE BIG STORY TONIGHT MAY BE THE WIND, ESPECIALLY ACROSS THE
HIGHER ELEVATIONS THAT FAVOR A SOUTHEAST WIND FLOW. WHILE WE ARE
VERY STABLE JUST A FEW THOUSAND FEET UP AND RAIN WILL LIKELY
TEMPER WINDS A BIT, STRONG WINDS UNDER THE INVERSION WILL FAVOR
LOCALLY STRONG GUSTS ON THE HILLTOPS. IN GENERAL GUSTS TO 20 MPH
ARE LIKELY TONIGHT FOR MOST OF US. FAVORED TERRAIN AREAS WILL
GUST BETWEEN 30 AND 40 MPH. THIS INCLUDES THE CATSKILLS, HIGHER
TERRAIN OF NEPA AND THE WESTERN SOUTHERN TIER AND THE HILLS SOUTH
OF SYRACUSE. WOULD NOT BE SURPRISED TO SEE A FEW GUSTS ABOVE 40
MPH ACROSS AREAS SUCH AS SEMPRONIUS, POMPEY, GEORGETOWN, IN THE
FAVORED SOUTHEAST FLOW AREAS SOUTH OF SYRACUSE.
MONDAY...
MODEL CONSENSUS STILL FAVORS THE STEADIER RAIN SLIDING EAST AND
PERHAPS EVEN OUT OF OUR AREA BY MIDDAY. MOST OF OUR AREA WILL GET
INTO THE WARM SECTOR BY AFTERNOON AND PERHAPS EVEN A FEW BREAKS IN
THE CLOUD COVER. THIS MAY GIVE US JUST ENOUGH INSTABILITY,
ESPECIALLY IF WE CAN SEE SOME SUN, TO COMBINE WITH A COLD FRONT
APPROACHING DURING THE EVENING FOR SOME THUNDERSTORMS. SPC DAY 2
OUTLOOK HAS MOVED THE SLIGHT RISK TOWARD OUR AREA AND JUST BRUSHES
SOUTHERN LUZERNE COUNTY. IN ADDITION A MARGINAL RISK (OLD SEE TEXT
FROM PAST YEARS) IS NOW UP TO NEAR THE NY STATE THRUWAY. WILL
CONTINUE TO MENTION T-STORMS IN THE FORECAST. SHEAR VALUES ARE
GOOD BUT IT WILL COME DOWN TO HOW MUCH INSTABILITY WE CAN REALIZE
DURING THE AFTERNOON TO DETERMINE SEVERE RISK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
345 PM UPDATE...
A COLD FRONT WILL BE MOVING THROUGH THE AREA MONDAY EVENING. WITH
LINGERING INSTABILITY, THUNDERSTORMS WILL BE POSSIBLE ACROSS THE
ENTIRE AREA. ALL HI RESOLUTION GUIDANCE POINTS TO THE POTENTIAL
OF A SQUALL LINE BETWEEN 21Z MONDAY AND 03Z TUESDAY ROUGHLY FROM
THE SOUTHERN TIER OF NY INTO NEPA. ADJUSTED OUR CURRENT HWO TO
REFLECT THIS THREAT ESPECIALLY ACROSS NEPA, WHICH IS CLOSE TO
WHAT SPC IS FORECASTING FOR SEVERE RISK.
BEYOND MONDAY NIGHT, THE PERIOD WILL BE DOMINATED BY A CLOSED
UPPER LOW JUST NORTH OF THE GREAT LAKES. GRADUALLY THROUGH THE
PERIOD WE WILL SEE PROGRESSIVELY COOLER AIR FILTER INTO THE AREA
ALONG WITH PERIODS OF SHOWERS. THIS WILL TRANSLATE INTO NEAR
NORMAL HIGHS TUESDAY (MID TO UPPER 50S) BUT THEN BELOW NORMAL
HIGHS BY WEDNESDAY. IN FACT SOME AREAS MAY NOT GET OUT OF THE 40S
FOR HIGHS WEDNESDAY AFTERNOON. THROUGH WEDNESDAY MOST AREAS WILL
SEE JUST RAIN SHOWERS. 850 TEMPS DO DROP BELOW ZERO BY WED MORNING
SO A STRAY FLAKE COULDN`T BE RULED OUT IN CNY EARLY IN THE DAY,
BUT THE APPRECIABLE COLDER AIR HOLDS OFF UNTIL WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
0330 AM UPDATE...NO CHANGES WERE MADE TO THE LONG TERM GRIDS WITH
THIS UPDATE AS MODELS IN OVERALL GOOD AGREEMENT CONTINUING TO
INDICATE COOL, GENERALLY UNSETTLED CONDITIONS FOR THE LONG RANGE.
PREVIOUS DISCUSSION...THE EXTENDED FORECAST WILL BE DOMINATED BY
AN UPPER LEVEL LOW WHICH SLOWLY MOVES FROM NEARBY SOUTHERN ONTARIO
TO NOVA SCOTIA. WILL CONTINUE TO ADVERTISE CHC/SLIGHT CHC POPS
EACH DAY. BEST CHANCES FOR SHOWERS WILL BE WED NIGHT WITH THE
PASSAGE OF A SFC OCCLUSION AND DURING THE DAYTIME PERIODS AS COLD
POOL ALOFT AND DIURNAL INSTABILITY WILL INCREASE COVERAGE. AIRMASS
IS COLD ENOUGH DURING THE OVERNIGHT PERIODS FOR A SNOW/RAIN SHOWER
MIX. TEMPS WILL RUN 5 TO 15 DEGREES BELOW NORMAL.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
06Z MON UPDATE... THE MOST SIG ISSUE THIS PD IS LIKELY TO BE THE
GUSTY SFC WINDS/LLWS...SPCLY LTR TNT AND MON MRNG. GIVEN AN
EXPECTED SE FLOW...KSYR/KITH/KBGM ARE LIKELY TO EXPERIENCE THE
STGST/MOST PERSISTENT GUSTS...WITH LOCAL TERRAIN EFFECTS (30-35 KT
INDICATED). LLWS WILL ESPECIALLY BE A CONCERN AT KELM/KAVP...WITH
THE MOST SIGNIFICANT WIND SPEED DIFFERENCE BETWEEN THE SFC AND
2000 FEET AGL (PROJECTED WINDS AT THE 2000 FOOT LVL OF 50-60 KT)
HOWEVER WE HAVE ADDED IT FOR THE OTHER SITES AS WELL WITH THIS
UPDATE AS CRITERIA IS EXPECTED TO BE MET.
VFR WILL CONTINUE FOR MUCH OF THE OVERNIGHT PD. SOME RESTRICTIONS
ARE PSBL MON MRNG...WHEN A BAND OF STEADIER RAIN IS EXPECTED TO
CROSS THE RGN. MVFR RESTRICTIONS ARE THE MOST LIKELY SCENARIO
(ROUGHLY 08-16Z)...WITH KRME/KBGM/KITH THE MOST PROBABLE SITES TO
BE IMPACTED.
FOR MOST OF MON AFTN...VFR SHOULD RETURN...AS A LULL IN PCPN IS
EXPECTED. LATE IN THE DAY (AFTER 21Z)...A LN OF SHWRS/PSBL TSTMS
WILL LIKELY IMPACT THE AREA...WITH MVFR RESTRICTIONS AGN PSBL. ANY
STORMS COULD ALSO PRODUCE STRONG WIND GUSTS WITH EVEN THE RISK OF
HAIL. FOR THE TIME BEING...FCST RANGE (OUT NEARLY 18 HRS) AND
UNCERTAIN COVERAGE PRECLUDES MENTION OF THUNDER IN THE TERMINAL
FCSTS BUT THE BEST CHANCE FOR STORMS WILL BE FOR KELM/KAVP/KBGM.
.OUTLOOK...
MON NIGHT-FRI...UNSETTLED PATTERN. RESTRICTIONS IN -SHRA, LOW
CLOUDS...ESP MON NGT.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
NEAR TERM...HEDEN
SHORT TERM...HEDEN
LONG TERM...PCF/RRM
AVIATION...PCF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
156 AM EDT MON APR 20 2015
.SYNOPSIS...
WIDESPREAD RAIN WILL DEVELOP OVER OUR AREA LATER TONIGHT INTO
EARLY MONDAY AS A STORM SYSTEM MOVES THROUGH THE GREAT LAKES.
AFTER A BRIEF LULL IN RAIN MIDDAY MONDAY, ANOTHER ROUND OF SHOWERS
IS POSSIBLE MONDAY AFTERNOON AND EVENING. DURING THAT TIME
SCATTERED THUNDERSTORMS ARE POSSIBLE. WE WILL REMAIN UNSETTLED AND
VERY COOL THE REST OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
940 PM UPDATE...
TIMING OF RAINFALL LOOKS TO BE ON TRACK. I TWEAKED THE OVERNIGHT
WIND GRIDS A BIT. WE STILL HAVE GUSTS OVER 40 MPH ON THE HILLTOPS
ABOVE 1500 FEET. I INCREASED WIND IN THE LAKE PLAIN, SHOWING SOME
GUSTS IN THE LOWER 30S AT KSYR. RUC SOUNDINGS SEEM A BIT LOW HERE
GIVEN FAVORABLE SOUTHEAST DOWNSLOPING AND MAV GUIDANCE SHOWING
SUSTAINED WINDS IN THE LOWER 20S. OTHERWISE PREVIOUS AFD IS
BELOW...
300 PM UPDATE...
A BEAUTIFUL END TO OUR WEEKEND ALBEIT A GOOD 10 DEGREES OR SO
COOLER THAN YESTERDAY AFTERNOON. I HOPE YOU ENJOYED THE WEEKEND
BECAUSE THE WEATHER THROUGH THE END OF THE MONTH DOESN`T LOOK ALL
THAT GOOD.
WE ARE ALREADY SEEING SIGNS OF THOSE CHANGES IN THE FORM OF SOME
THIN WISPY HIGH CLOUDS. THESE ARE WELL AHEAD OF AN AREA OF LOW
PRESSURE NOW OVER ILLINOIS THAT WILL TRACK THROUGH THE GREAT
LAKES MONDAY. A LARGE SHIELD OF RAIN WELL AHEAD OF A WARM FRONT
WITH THIS SYSTEM WILL MOVE IN TONIGHT. NOT EXPECTING ANY HYDRO
ISSUES BUT A QUICK SHOT OF STEADY RAIN IS LIKELY FOR EVERYONE.
THE BIG STORY TONIGHT MAY BE THE WIND, ESPECIALLY ACROSS THE
HIGHER ELEVATIONS THAT FAVOR A SOUTHEAST WIND FLOW. WHILE WE ARE
VERY STABLE JUST A FEW THOUSAND FEET UP AND RAIN WILL LIKELY
TEMPER WINDS A BIT, STRONG WINDS UNDER THE INVERSION WILL FAVOR
LOCALLY STRONG GUSTS ON THE HILLTOPS. IN GENERAL GUSTS TO 20 MPH
ARE LIKELY TONIGHT FOR MOST OF US. FAVORED TERRAIN AREAS WILL
GUST BETWEEN 30 AND 40 MPH. THIS INCLUDES THE CATSKILLS, HIGHER
TERRAIN OF NEPA AND THE WESTERN SOUTHERN TIER AND THE HILLS SOUTH
OF SYRACUSE. WOULD NOT BE SURPRISED TO SEE A FEW GUSTS ABOVE 40
MPH ACROSS AREAS SUCH AS SEMPRONIUS, POMPEY, GEORGETOWN, IN THE
FAVORED SOUTHEAST FLOW AREAS SOUTH OF SYRACUSE.
MONDAY...
MODEL CONSENSUS STILL FAVORS THE STEADIER RAIN SLIDING EAST AND
PERHAPS EVEN OUT OF OUR AREA BY MIDDAY. MOST OF OUR AREA WILL GET
INTO THE WARM SECTOR BY AFTERNOON AND PERHAPS EVEN A FEW BREAKS IN
THE CLOUD COVER. THIS MAY GIVE US JUST ENOUGH INSTABILITY,
ESPECIALLY IF WE CAN SEE SOME SUN, TO COMBINE WITH A COLD FRONT
APPROACHING DURING THE EVENING FOR SOME THUNDERSTORMS. SPC DAY 2
OUTLOOK HAS MOVED THE SLIGHT RISK TOWARD OUR AREA AND JUST BRUSHES
SOUTHERN LUZERNE COUNTY. IN ADDITION A MARGINAL RISK (OLD SEE TEXT
FROM PAST YEARS) IS NOW UP TO NEAR THE NY STATE THRUWAY. WILL
CONTINUE TO MENTION T-STORMS IN THE FORECAST. SHEAR VALUES ARE
GOOD BUT IT WILL COME DOWN TO HOW MUCH INSTABILITY WE CAN REALIZE
DURING THE AFTERNOON TO DETERMINE SEVERE RISK.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
345 PM UPDATE...
A COLD FRONT WILL BE MOVING THROUGH THE AREA MONDAY EVENING. WITH
LINGERING INSTABILITY, THUNDERSTORMS WILL BE POSSIBLE ACROSS THE
ENTIRE AREA. ALL HI RESOLUTION GUIDANCE POINTS TO THE POTENTIAL
OF A SQUALL LINE BETWEEN 21Z MONDAY AND 03Z TUESDAY ROUGHLY FROM
THE SOUTHERN TIER OF NY INTO NEPA. ADJUSTED OUR CURRENT HWO TO
REFLECT THIS THREAT ESPECIALLY ACROSS NEPA, WHICH IS CLOSE TO
WHAT SPC IS FORECASTING FOR SEVERE RISK.
BEYOND MONDAY NIGHT, THE PERIOD WILL BE DOMINATED BY A CLOSED
UPPER LOW JUST NORTH OF THE GREAT LAKES. GRADUALLY THROUGH THE
PERIOD WE WILL SEE PROGRESSIVELY COOLER AIR FILTER INTO THE AREA
ALONG WITH PERIODS OF SHOWERS. THIS WILL TRANSLATE INTO NEAR
NORMAL HIGHS TUESDAY (MID TO UPPER 50S) BUT THEN BELOW NORMAL
HIGHS BY WEDNESDAY. IN FACT SOME AREAS MAY NOT GET OUT OF THE 40S
FOR HIGHS WEDNESDAY AFTERNOON. THROUGH WEDNESDAY MOST AREAS WILL
SEE JUST RAIN SHOWERS. 850 TEMPS DO DROP BELOW ZERO BY WED MORNING
SO A STRAY FLAKE COULDN`T BE RULED OUT IN CNY EARLY IN THE DAY,
BUT THE APPRECIABLE COLDER AIR HOLDS OFF UNTIL WEDNESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE EXTENDED FORECAST WILL BE DOMINATED BY AN UPPER LEVEL LOW
WHICH SLOWLY MOVES FROM NEARBY SOUTHERN ONTARIO TO NOVA SCOTIA.
WILL CONTINUE TO ADVERTISE CHC/SLIGHT CHC POPS EACH DAY. BEST
CHANCES FOR SHOWERS WILL BE WED NIGHT WITH THE PASSAGE OF A SFC
OCCLUSION AND DURING THE DAYTIME PERIODS AS COLD POOL ALOFT AND
DIURNAL INSTABILITY WILL INCREASE COVERAGE. AIRMASS IS COLD ENOUGH
DURING THE OVERNIGHT PERIODS FOR A SNOW/RAIN SHOWER MIX. TEMPS
WILL RUN 5 TO 15 DEGREES BELOW NORMAL.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
06Z MON UPDATE... THE MOST SIG ISSUE THIS PD IS LIKELY TO BE THE
GUSTY SFC WINDS/LLWS...SPCLY LTR TNT AND MON MRNG. GIVEN AN
EXPECTED SE FLOW...KSYR/KITH/KBGM ARE LIKELY TO EXPERIENCE THE
STGST/MOST PERSISTENT GUSTS...WITH LOCAL TERRAIN EFFECTS (30-35 KT
INDICATED). LLWS WILL ESPECIALLY BE A CONCERN AT KELM/KAVP...WITH
THE MOST SIGNIFICANT WIND SPEED DIFFERENCE BETWEEN THE SFC AND
2000 FEET AGL (PROJECTED WINDS AT THE 2000 FOOT LVL OF 50-60 KT)
HOWEVER WE HAVE ADDED IT FOR THE OTHER SITES AS WELL WITH THIS
UPDATE AS CRITERIA IS EXPECTED TO BE MET.
VFR WILL CONTINUE FOR MUCH OF THE OVERNIGHT PD. SOME RESTRICTIONS
ARE PSBL MON MRNG...WHEN A BAND OF STEADIER RAIN IS EXPECTED TO
CROSS THE RGN. MVFR RESTRICTIONS ARE THE MOST LIKELY SCENARIO
(ROUGHLY 08-16Z)...WITH KRME/KBGM/KITH THE MOST PROBABLE SITES TO
BE IMPACTED.
FOR MOST OF MON AFTN...VFR SHOULD RETURN...AS A LULL IN PCPN IS
EXPECTED. LATE IN THE DAY (AFTER 21Z)...A LN OF SHWRS/PSBL TSTMS
WILL LIKELY IMPACT THE AREA...WITH MVFR RESTRICTIONS AGN PSBL. ANY
STORMS COULD ALSO PRODUCE STRONG WIND GUSTS WITH EVEN THE RISK OF
HAIL. FOR THE TIME BEING...FCST RANGE (OUT NEARLY 18 HRS) AND
UNCERTAIN COVERAGE PRECLUDES MENTION OF THUNDER IN THE TERMINAL
FCSTS BUT THE BEST CHANCE FOR STORMS WILL BE FOR KELM/KAVP/KBGM.
.OUTLOOK...
MON NIGHT-FRI...UNSETTLED PATTERN. RESTRICTIONS IN -SHRA...ESP
MON NGT.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
NEAR TERM...HEDEN
SHORT TERM...HEDEN
LONG TERM...RRM
AVIATION...PCF
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
435 AM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE EAST THROUGH THE GREAT LAKES AND OHIO
VALLEY TODAY. BREEZY TO WINDY CONDITIONS ARE EXPECTED ON TUESDAY
AHEAD OF A WEAK COLD FRONT. THIS FRONT WILL PUSH THROUGH THE
REGION TUESDAY NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
IT WILL BE A COMPLEX POP FORECAST THIS MORNING GIVEN VARIOUS
OPERATIONAL MODELS AND CONVECTION ALLOW MODELS SOLUTIONS. HAVE
USED A BLEND OF THE NCEP HRRR AND THE ESRL HRRR TO TRY TO PINPOINT
POPS AND TIMING OF PCPN TODAY.
AN EMBEDDED S/WV TO OUR SOUTHWEST THIS MORNING IS FORECAST TO
EJECT NORTHEAST ACROSS OUR REGION THROUGH EARLY AFTERNOON. IT WILL
ALSO BE ACCOMPANIED BY A COLD FRONT. MOSAIC RADAR CONTINUES TO
DEPICT AN AREA OF SHOWERS/EMBEDDED THUNDER APPROACHING THE
CINCINNATI TRI-STATE REGION. THIS PCPN SHOULD PUSH INTO THE
SOUTHWESTERN AND WESTERN ZONES EARLY THIS MORNING AND AS SUCH HAVE
GONE WITH LIKELY POPS IN THESE LOCATIONS. FOR THE REMAINDER OF THE
REGION...IT GETS A LITTLE TRICKY AS CAMS TRY TO WEAKEN PCPN SHIELD
AND THEN FOCUS MORE SCATTERED SHOWERS/EMBEDDED THUNDERSTORMS ALONG
AND AHEAD OF THE COLD FRONT. HAVE GONE WITH HIGH CHANCE POPS IN
THE EAST TO ACCOUNT FOR THIS. THERE IS A MARGINAL RISK OF SEVERE
STORMS TODAY OVER OUR EASTERN TWO THIRDS CWFA. INSTABILITY SEEMS
TO BE LACKING OVERALL DESPITE SOME FAVORABLE WINDS ALOFT. BELIEVE
WE WILL PROBABLY SEE SOME GUSTY WINDS WITH SHOWERS/THUNDERSTORMS...
BUT THEY SHOULD STAY BELOW SEVERE LIMITS. WE WILL ALSO SEE SOME
SYNOPTIC SCALE GUSTS IN THE 25 TO 30 KNOT RANGE AS CAA DEVELOPS IN
THE WAKE OF THE FRONT. HIGHS TODAY WILL BE TOUGH GIVEN EARLY
WARMTH AND THEN A GRADUAL DROP TO TEMPERATURES FROM WEST TO EAST
IN THE CAA PATTERN. HAVE RANGED HIGHS FROM NEAR 60 WEST TO THE
UPPER 60S EAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
MODELS INDICATE THAT THERE COULD BE A FEW LIGHT SHOWERS LINGERING
BEHIND THE FRONT THIS EVENING. THEREAFTER...SKIES SHOULD GRADUALLY
BECOME MOSTLY CLEAR AS DRIER AIR ADVECTS INTO THE AREA.
FOR TUESDAY INTO WEDNESDAY...HAVE TAKEN A BLEND OF THE ECMWF AND
THE NAM-WRF. THE OPERATIONAL GFS SEEMS PECULIAR WITH ITS BIG QPF
BULLSEYES FOR TUESDAY NIGHT INTO WEDNESDAY GIVEN THE MOISTURE
STARVED REGIME. WE SHOULD SEE PARTLY TO MOSTLY SUNNY SKIES FOR
MUCH OF THE DAY. BIGGEST WEATHER MAKER WILL BE THE WINDS. PRESSURE
GRADIENT BETWEEN LOW PRESSURE TO OUR NORTH AND HIGH PRESSURE TO
OUR SOUTH...COMBINED WITH DEEP ADIABATIC MIXING...WILL RESULT IN
BREEZY TO WINDY CONDITIONS FROM LATE MORNING INTO THE EARLY
EVENING. THE GFS IS THE ONLY MODEL THAT WOULD INDICATE THE NEED
FOR A WIND ADVISORY ACRS OUR NRN ZONES FOR TUESDAY. SINCE THIS IS
THE OUTLIER ATTM...HAVE GONE WITH THE NAM WHICH KEEPS SUSTAINED
WINDS IN THE 15 TO 25 KNOT RANGE AND GUSTS GENERALLY IN THE 25 TO
35 RANGE. WE NEED SUSTAINED 27 KNOTS AND GUSTS OF 40 KNOTS FOR A
WIND ADVISORY. BY LATE IN THE DAY...MODELS INDICATE THAT A TONGUE
OF MAINLY MID LEVEL MOISTURE WILL PUSH INTO THE SRN ZONES. GIVEN
DRY LOWER LEVELS...HAVE OPTED TO JUST MENTIONED A SLIGHT CHANCE
FOR LIGHT SHOWERS HERE.
FOR TUESDAY NIGHT INTO WEDNESDAY...A WEAK COLD FRONT WILL PUSH
SOUTHEAST THROUGH THE FORECAST AREA. A CONVERGENT CONFIGURATION
IN THE LOW LEVELS MAY BRING A SLIGHT CHC/CHC FOR SHOWERS ACRS THE
SRN ZONES TUESDAY NIGHT. IT NOW LOOKS LIKE WEDNESDAY SHOULD BE DRY
AS WE WILL BE BETWEEN SYSTEMS. IT WILL CONTINUE TO COOL THROUGH
THE PERIOD.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A VERY COOL AND DRY PERIOD EXPECTED FOR THU/FRI BEFORE LARGE SCALE
UPR LOW FINALLY LIFTS JUST ENOUGH NORTH TO ALLOW FOR A MORE VIGOROUS
SOUTHERN STREAM S/WV TO AGAIN BRING SHOWERS TO THE SOUTHERN FCST
AREA.
CONTINUED THE UNSEASONABLY COOL TREND WITH THE UPR LOW DOMINATING
THE NORTHERN AREA AND GENERAL NW FLOW THROUGH MUCH OF THE PERIOD.
POTENTIAL FOR MID/UPR 30S FOR LOW TEMPS WED NIGHT AND LOW/MID 30S
THURS NIGHT.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
SHOWERS ARE MOVING OUT OF THE AREA RIGHT NOW...LEAVING DRY
CONDITIONS FOR THE REST OF THE OVERNIGHT HOURS. CEILINGS SHOULD
GENERALLY REMAIN IN THE MVFR CATEGORY THROUGH MORNING...WITH A FEW
BREAKS TO VFR POSSIBLE.
ANOTHER ROUND OF SHOWERS IS EXPECTED TO MOVE INTO THE REGION
BETWEEN 11Z AND 14Z...WITH A POSSIBILITY FOR REDUCED VISIBILITIES.
MVFR CEILINGS ARE EXPECTED TO BECOME THICKER THROUGH THE MORNING
WITH RAIN IN THE VICINITY. AS THIS IS OCCURRING...WINDS WILL SHIFT
TO THE SSW AND INCREASE IN STRENGTH. WIND GUSTS AS HIGH AS 30
KNOTS WILL BE POSSIBLE.
ADDITIONAL SHOWERS MAY DEVELOP DURING THE AFTERNOON AND EARLY
EVENING...BUT THESE WILL BE DISORGANIZED AND BRIEF...AND ARE
COVERED WITH A VCSH IN THE TAFS. WINDS WILL EVENTUALLY SHIFT TO
THE WSW AND WEAKEN SLIGHTLY BY EVENING...AS CLOUDS BREAK TO VFR
AROUND THE SAME TIME.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...JDR
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
353 AM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY BRINGING ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS. DRY HIGH PRESSURE BUILDS IN FOR TUESDAY
AND WEDNESDAY. ANOTHER COLD FRONT WILL PUSH IN FROM THE NORTHWEST ON
THURSDAY...POSSIBLY BRINGING SHOWERS BACK TO THE AREA. A STRONGER
STORM SYSTEM WILL MOVE IN FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM...IN THE IMMEDIATE NEAR TERM...THE RADAR HAS GONE INTO
CLEAR AIR MODE...AS A LEAD SHORTWAVE HAS EXITED TO THE NE WITHIN
DEEP LAYER SWLY FLOW. A QUASI-LINEAR MCS IS CURRENTLY CROSSING
CENTRAL TN AND NRN AL. GUIDANCE SEEMS TO BE UNDERESTIMATING THE
STRENGTH/PERSISTENCE OF THIS SYSTEM. THE LATEST RAP ANALYSIS SHOWS
500-1000 J/KG OF MUCAPE WITH 35-45 KTS OF EFFECTIVE SHEAR DOWNSTREAM
OF THIS CLUSTER. THIS RESULTS IN A /MCS MAINTENANCE/ PROB AT 70-80
PCT. SO IT IS NOW EXPECTED THAT THESE STORMS (WHILE STILL ON A
GRADUAL WEAKENING TREND) WILL LIKELY STILL SURVIVE INTO THE NC MTNS
EARLY THIS MORNING. GIVEN THE CURRENT STATE...CANNOT RULE OUT A
STRONG OR SEVERE STORM OR TWO...ESP IN GRAHAM/SWAIN...WHEN THE LINE
GETS INTO THE CWFA. FROM THERE...IT/S DIFFICULT TO SAY HOW MUCH
PRECIP WILL LINGER ACRS THE CWFA THIS MORNING. I HAVE BUMPED UP POP
IN THE WRN MTNS...BUT KEEP JUST A SHOTGUN CHC POP FOR THE REST OF
THE AREA THIS MORNING.
LATER TODAY...GUIDANCE IN GOOD AGREEMENT ON ANOTHER SPOKE OF
VORTICITY ROTATING AROUND THE BROAD CYCLONICALLY CURVED
FLOW...CROSSING THE CWFA FROM THE SOUTHWEST DURING THE PEAK-HEATING
AFTN HOURS. MEANWHILE...A COLD FRONT WILL PUSH INTO THE AREA THIS
AFTN. THE FRONT LOOKS TO ONLY HAVE MODEST LLVL CONVERGENCE.
HOWEVER...GIVEN THE STEEP MID LVL LAPSE RATES AND LINGERING BL
MOISTURE (DEWPTS IN THE MID 60S ACRS THE PIEDMONT). FAIRLY CONFIDENT
IN AT LEAST 40-50 PCT COVERAGE OF CONVECTION...MAYBE HIGHER TO THE
EAST. THE FCST SNDGS SHOW LONG BUT SLIGHTLY CURVED HODOGRAPHS WITH
1500-2500 J/KG OF UNCAPPED SBCAPE. SO EXPECT SOMEWHAT DISCRETE
STORMS INITIALLY...WITH POTENTIAL FOR SUPERCELLS. DEFINITELY WILL
BE A DAMAGING WIND AND HAIL THREAT...WITH AN ISOLD TORNADO THREAT
ACRS THE PIEDMONT THIS AFTN. THE HIGH RES MODELS DO NOT SEEM THAT
IMPRESSED WITH COVERAGE OR INTENSITY. I/M NOT SURE WHAT IS LIMITING
THEIR CONVECTION EXPECT FOR PERHAPS LACK OF DEEPER MOISTURE. THE NEW
DAY 1 CONVECTIVE OUTLOOK STILL HAS ALL AREAS EAST OF THE MTNS IN THE
SLGT RISK...AND A MARGINAL RISK FOR THE MTNS. OTHERWISE...IT WILL BE
BREEZY TODAY UNDER MOSTLY CLOUDY TO PARTLY CLOUDY SKIES WITH TEMPS
BACK ABOVE NORMAL AHEAD OF THE FRONT.
TONIGHT...DRY AIR WILL FILTER IN FROM THE WEST BEHIND THE FRONT.
POPS WILL TAPER OFF...LINGERING THRU THE EVENING ALONG THE TN BORDER
DUE TO UPSLOPE NWLY FLOW. LOWS WILL BE A COUPLE CATEGORIES ABOVE
NORMAL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM MONDAY...THINGS DRY OUT TUE AS DRY HIGH PRESSURE BUILDS
IN FROM THE WEST. EXPECT A MILD AND BREEZY DAY WITH HIGHS UP TO 5
DEGREES BELOW NORMAL. A BROAD AND LOW AMPLITUDE UPPER TROF SETS UP
ACROSS THE AREA FOR WED. WEAK SHORT WAVES MOVING THRU THE TROF WILL
HELP PUSH A WEAK COLD FRONT INTO THE AREA WED AND SOUTH OF THE AREA
WED NITE. THERE IS NOT A LOT OF DEEP MOISTURE WITH THIS SYSTEM AND
THE FORCING IS WEAK. THEREFORE...EXPECT SCT SHRA NEAR THE TN BORDER
WHERE THE MOISTURE IS DEEPEST AND WLY FLOW WILL HELP INCREASE
FORCING. ELSEWHERE...ONLY ISOLATED SHRA ARE EXPECTED...WITH LITTLE
CHC OF PRECIP SOUTH OF I-85. HIGHS WILL RISE TO NEAR NORMAL WED...
WITH LOWS NEAR NORMAL TUE NITE AND ABOVE NORMAL WED NITE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 AM MONDAY...AN UPPER TROF AXIS WILL SLIDE EAST OF THE AREA
THURSDAY ALLOWING FLAT RIDGING TO BUILD IN ON FRI. A SHORT WAVE
CROSSES THE AREA SATURDAY WITH ANOTHER BROAD AND LOW AMPLITUDE UPPER
TROF DEVELOPING ON SUNDAY.
HIGH PRESSURE BRIEFLY RETURNS TO THE AREA FRI BEFORE A STRONGER
STORM SYSTEM MOVES IN ON SATURDAY. PRECIP CHC SLOWLY RAMPS UP FRIDAY
WITH POTENTIALLY HEAVY PRECIP ON SATURDAY. DRY HIGH PRESSURE RETURNS
FOR SUNDAY. NEAR NORMAL HIGHS THURSDAY...FALL BELOW NORMAL FOR THE
REST OF THE PERIOD. LOWS BOUNCE AROUND FROM NEAR TO A LITTLE ABOVE
NORMAL.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...PLENTY OF LLVL MOISTURE ACRS THE AREA WITH
AN INCREASING SWLY LLVL JET OVERNIGHT SHUD RESULT IN A FAIR AMOUNT
OF LIFR TO MVFR CIGS THRU DAYBREAK. THERE WILL BE A BAND OF DECAYING
CONVECTION APPROACHING THE AREA FROM THE WEST DURING THE PRE-DAWN
HOURS. HOWEVER...GUIDANCE IN GOOD AGREEMENT THAT THE PRECIP SHUD
PRETTY MUCH FIZZLE BY THE TIME IT PUSHES INTO THE NC MTNS AROUND
DAYBREAK. DURING THE DAY TODAY...STRATUS SHUD MIX/SCT INTO AN MVFR
TO LOW VFR CU DECK...WITH INCREASING INSTBY EXPECTED BY THE AFTN.
EXPECTING MAINLY SCATTERED SHRA AND TSRA TO DEVELOP THIS AFTN...SO
WILL KEEP A PROB30 FOR ALL SITES. WINDS WILL BECOME QUITE GUSTY OUT
OF THE SW...WITH GUSTS FREQUENTLY IN THE 20-25 KT RANGE EXPECTED. A
COLD FRONT WILL PUSH THRU THE AREA LATE AFTN INTO THE
EVENING...ENDING THE CONVECTION CHCS AND SHIFTING WINDS TO W AND NW
BY THE END OF THE TAF PERIOD. DRY AIR SHUD FILTER OUT ANY LOW
CLOUDS...AND ONLY CIRRUS EXPECTED THIS EVENING.
OUTLOOK...DRY HIGH PRESSURE WILL BUILD IN ACROSS THE REGION FOR THE
MIDDLE OF THE WEEK...LEADING TO LOW PRECIP/RESTRICTION CHANCES.
CONFIDENCE TABLE...
08-14Z 14-20Z 20-02Z 02-06Z
KCLT MED 75% HIGH 87% HIGH 100% HIGH 100%
KGSP MED 64% MED 79% HIGH 89% HIGH 100%
KAVL MED 73% HIGH 95% MED 65% HIGH 90%
KHKY MED 60% HIGH 82% HIGH 98% HIGH 100%
KGMU LOW 50% MED 78% HIGH 89% HIGH 100%
KAND MED 64% MED 79% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...ARK
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1131 PM CDT SUN APR 19 2015
.UPDATE...FOR 06Z AVIATION DISCUSSION.
&&
.AVIATION...06Z AVIATION DISCUSSION.
SEVERAL ADMS CONTINUE TO BE POSSIBLE THRU AT LEAST 20/15Z DUE TO CEILING
AND VSBY FLUCTUATIONS AND SHWR/TSTM IMPACTS. AT 06Z...CSV SHOULD BE
EXPERIENCING SHWRS/TSTMS WITH TEMPO MVFR VSBYS/CEILINGS POSSIBLE AS
LEADING CONVECTIVE LINE OF SHWRS/TSTMS WITH AN AREA OF SHWRS/SCT TSTMS
BEHIND MOVES INTO MID STATE. EXPECT THIS TO BE THE EXPERIENCE BY NO
LATER THAN 07Z BNA...WITH CSV AROUND 09Z. EXPECT THESE LINGERING SHWRS/SCT
TSTMS BEHIND MAIN CONVECTIVE LINE FOR AT LEAST A COUPLE OF HRS...WITH
MVFR FOG INDUCED VSBYS DEVELOPING ALSO. MVFR CEILINGS EXPECTED BY 20/15Z...
WITH VFR CEILINGS POSSIBLE 20/18Z AND AFTERWARDS. CEILING EROSION EXPECTED
AT ALL TAF SITES BY 21/02Z.
&&
.PREV DISCUSSION.../ISSUED 818 PM CDT SUN APR 19 2015/
DISCUSSION...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REMOVE WORDING IN THE ZONE
FORECAST PRODUCT FOR THE THRU LATE AFTERNOON GROUPING. HAVE ALSO UPDATED
TO MATCH CURRENT REGIONAL SFC OBS....SATELLITE...AND RADAR TRENDS ALONG
WITH TWEAKS TO HRLY TEMP...DEWPOINT...SKY...AND WIND SPEED/DIRECTION GRIDS.
AN EMBEDDED SHORTWAVE IN UPPER LEVEL TROUGH THAT IS MOVING ACROSS NW INTO
NC PORTIONS OF THE MID STATE THIS EVENING SHOULD CONTINUE MOVING NEWD WITH
DEVELOPING ISO STRONG TO SVR TSTMS ASSOCIATED WITH IT GENERALLY MOVING THIS
WAY ALSO...WITH THE POSSIBILITY OF SHWRS/TSTMS MOVING INTO THE NASHVILLE METRO
AREA PRESENTLY. EXPECT MAYBE SOME ISO SHWRS/TSTMS THRU 05Z ACROSS REST OF MID
STATE. MAIN CONCERN IS LINE OF SVR CONVECTION APPROACHING THE MS RIVER VALLEY
AS OF 01Z AND ITS POTENTIAL IMPACTS ON THE MID STATE`S WX AS IT IS EXPECTED TO
APPROACH THE TN RIVER VALLEY REGION OF THE MID STATE BY 05Z.
LATEST SHORT RANGE MODELS SHOWING BRUNT OF ACTIVITY CURRENTLY OVER AR MOVING
GENERALLY NE OF MID STATE AS IT APPROACHES THE TN RIVER VALLEY BY 05Z...WITH
CONVECTION PRESENTLY ACROSS SRN AR/NRN LA MOVING NEWD DRAGGING A LINE OF
SHWRS/TSTMS INTO THE MID STATE. 00Z MON KOHX SOUNDING PROFILE AND INDICES
SHOWING RELATIVELY LOW CAPE AND LOW SHEAR VALUES AS OF THIS TIME...WITH
MARGINAL INSTABILITY AND PCPN WATER VALUES AROUND 1.2 INCHES AND UNIDIRECTIONAL
SWLY FLOW SFC/ALOFT. MODEL SOUNDINGS SHOWING SOME ENHANCEMENTS IN INSTABILITY
AND SHEAR VALUES BETWEEN 06Z-09Z ACROSS WRN AND CENTRAL PORTIONS OF THE MID
STATE WITH UNIDIRECTIONAL SWLY FLOW SFC/ALOFT CONTINUING. 01Z CONVECTIVE
OUTLOOK CURTAILING THE SLIGHT RISK OF SVR TSTM AREA ACROSS THE PLATEAU COUNTIES
AND NOW GENERALLY LIMITING THIS POSSIBILITY TO LOCATIONS W OF THE PLATEAU.
SPC STILL EXPECTING SOME WEAKENING AS THIS CURRENT LINE OF SHWRS/TSTMS
APPROACHING THE MS RIVER MOVES EWD TONIGHT PER BOUNDARY LAYER DESTABILIZATION.
WITH THIS ALL SAID...DO EXPECT A QUASI-LINEAR LINE OF SHWRS/TSTMS TO MOVE
THRU THE MID STATE FROM AROUND 11 PM ONWARD W THRU THE EARLY MORNING HRS
E...BUT WILL IT STILL CONTAIN STRONG TO SVR CONVECTION WITH IT? ALL INDICATIONS
AT THIS TIME IS THAT IT IS BORDERLINE IF IT DOES OR NOT...AS SFC FRONT ITSELF
SHOULD APPROACH THE MS RIVER BY 06Z AND THEN PUSH EWD INTO THE MID STATE
JUST W OF PLATEAU BY 12Z...AS UPPER LEVEL TROUGHING BECOMES MORE PRONOUNCED
ACROSS THE MID STATE. THUS UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT
THE ABOVE REASONING/TIMINGS MENTIONED.
PREV DISCUSSION.../ISSUED 645 PM CDT SUN APR 19 2015/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
SEVERAL ADMS POSSIBLE THRU AT LEAST 20/15Z DUE TO CEILING AND VSBY
FLUCTUATIONS AND SHWR/TSTM IMPACTS. EXPECT BEST POTENTIAL FOR
SHWRS/TSTMS NEAR CKV THRU 20/05Z PER PROXIMITY TO UPPER LEVEL TROUGH
DYNAMICS. EXPECTING BRUNT OF SHWRS/TSTMS BETWEEN 20/05Z W - 20/11Z E
AS CONVECTIVE LINE MOVES THRU MID STATE. MVFR CEILINGS TO IFR VSBYS
WILL BE POSSIBLE DURING THIS TIME PERIOD...ESPECIALLY WITH ONSET OF
SHWR/TSTM ACTIVITY AT TAF SITES. EXPECT LINGERING SHWRS BEHIND MAIN
CONVECTIVE LINE FOR AT LEAST A COUPLE OF HRS...WITH MVFR FOG INDUCED
VSBYS DEVELOPING ALSO. MVFR CEILINGS EXPECTED BY 20/15Z...WITH VFR
CEILINGS POSSIBLE 20/18Z AND AFTERWARDS.
PREV DISCUSSION.../ISSUED 200 PM CDT SUN APR 19 2015/
DISCUSSION...SURFACE MAP AT 18Z SHOWS A 1000 MB LOW CENTERED OVER
SOUTHERN ILLINOIS, WITH A WARM FROM SITUATED TO OUR NORTH, A
COLD FRONT STILL WEST OF THE MISSISSIPPI RIVER, AND A PRE-FRONTAL
TROUGH JUST NOW CROSSING THE TENNESSEE RIVER THAT IS PROVIDING THE
FOCUS FOR A DEVELOPING LINE OF CONVECTION. SATELLITE IMAGERY IS
STARTING TO SHOW SOME BREAKS IN THE CLOUDS, ESPECIALLY WEST OF
NASHVILLE. LAPS SOUNDING FOR BNA AT 18Z SHOWS WEAK INSTABILITY,
WITH A LIFTED INDEX OF -3.3 AND A CAPE OF 962 J/KG. ATMOSPHERE
REMAINS SUFFICIENTLY MOIST, WITH PRECIPITABLE WATER OF 1.44 INCHES
AND A K-INDEX OF 34. LATEST HRRR SHOWS SCATTERED CELLS ACROSS
MIDDLE TENNESSEE UNTIL A MORE ORGANIZED LINE OF CONVECTION COMES
THROUGH WITH THE COLD FRONT BETWEEN 04Z AND 09Z. GIVEN THE TIMING
OF THE FRONT, THE POTENTIAL FOR WIDESPREAD SEVERE STORMS APPEARS
LOW, ALTHOUGH MIDDLE TENNESSEE DOES REMAIN UNDER A SLIGHT RISK OF
SEVERE WEATHER TODAY AND TONIGHT, SO ISOLATED CASES OF SEVERE
ACTIVITY ARE STILL POSSIBLE. AFTER A FEW LINGERING SHOWERS ON
MONDAY, LOOK FOR A BRIEF RESPITE ON TUESDAY BEFORE THE NEXT COLD
FRONT DROPS SOUTHWARD THROUGH MIDDLE TENNESSEE WEDNESDAY AND
THURSDAY. GIVEN THAT THE UPPER FLOW ACROSS THE REGION WILL REMAIN
EITHER CYCLONIC OR ZONAL, WARM ADVECTION WILL BE HARD TO COME BY,
AND SO TEMPERATURES DURING THE NEXT 7 DAYS WILL REMAIN AT OR BELOW
NORMAL.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
110 AM EDT MON APR 20 2015
.SYNOPSIS...
LOW PRESSURE OVER WESTERN KENTUCKY WITH A WARM FRONT EXTENDING EAST
AND COLD FRONT TRAILING SOUTHWARD FROM THE LOW WILL LIFT NORTHEAST
TONIGHT INTO MONDAY. A COLD FRONT CROSSES THE REGION ON
MONDAY...THEN HIGH PRESSURE BUILDS IN FOR TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 100 AM EDT MONDAY...
HEAVY RAIN HAS MOVED NORTH OF THE AREA...THEREFORE THE FLOOD WATCH
HAS BEEN CANCELLED FOR THE ENTIRE AREA.
PREVIOUS DISCUSSION...
AS OF 333 PM EDT SUNDAY...
A WARM FRONT TO OUR SOUTH WILL LIFT NORTH THIS EVENING AND CROSS THE
FORECAST AREA TONIGHT. DEEPER MOISTURE AND HIGHER PWATS WILL
INCREASE IN THE WARM ADVECTION WITH THE NORTHWARD ADVANCE OF THE
FRONT. THE REGIONAL RADAR IMAGE SHOWED WIDESPREAD CONVECTION ACROSS
THE MID ATLANTIC REGION SOUTHWARD TO THE SOUTHEAST US. THERE ARE
SOME CONCERNS OF STRONG CONVECTION ACROSS GEORGIA THIS AFTERNOON MAY
TAKE SOME OF THE MOISTURE AWAY FROM OUR AREA. OUR LOCAL RNK
WRFARW...HIRESW-ARW...NAM AND GFS WAIT UNTIL AFTER 00Z BEFORE
BRINGING IN HEAVIER CONVECTION THIS EVENING...WHILE HRRR AND ECMWF
ARE A LITTLE FASTER WITH TIMING. THE HRRR AND HIRESW-ARW LIFTS THE
PRECIPITATION NORTHEAST WITH MOST OF RAIN PULLING OUT BY 06-08Z.
USED A BLEND OF HRRR AND NAM FOR POPS...TAPERING POPS BACK AFTER 06Z
TONIGHT INTO MONDAY MORNING.
NOT EXPECTING ANY STRONG THUNDERSTORMS THIS AFTERNOON INTO TONIGHT
WITH CLOUD COVER HINDERING INSTABILITIES. HOWEVER...THE LOW LEVEL
JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL RESULT IN
STRONG UPSLOPE AND ISENTROPIC LIFT. THE STRONG WINDS THROUGH A
DEEP LAYER WILL PROVIDE LARGE HELICITY VALUES LATE THIS AFTERNOON
INTO THIS EVENING. THE DAY ONE CONVECTIVE OUTLOOK (SWODY1) PLACED
A MARGINAL (5 PERCENT CHANCE OF WIND) ACROSS SOUTHWEST PORTION OF
CWA. PLAYED LOW TEMPERATURES CLOSE TO ADJMAV WITH READINGS FROM
THE UPPER 40S IN THE NORTHWEST MOUNTAINS TO AROUND 60 DEGREES IN
THE PIEDMONT.
A WARM...MOIST AND UNSTABLE AIRMASS EXPECTED MONDAY. THE ATMOSPHERE
WILL DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT WITH SHOWERS
AND THUNDERSTORMS DEVELOPING MONDAY. INITIALLY CUT BACK POPS CLOSER
TO NAM FOR MONDAY MORNING...THEN INCREASED TO LIKELY BY MONDAY
AFTERNOON. SPC CONTINUES OUR SLIGHT RISK FOR MONDAY ACROSS MOST OF
OUR CWA. THIS IS SUPPORTED BY THE DYNAMIC ENVIRONMENT WITH HEALTHY
SHEAR AND DECENT CAPES AROUND 2K. IT WILL ALSO BE QUITE BREEZY WITH
EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER.
THE FRONT SHOULD BE CLEARING MONDAY NIGHT. HIGH TEMPERATURES MONDAY
WILL RANGE FROM THE MID 60S IN THE MOUNTAINS TO THE LOWER 80S IN THE
PIEDMONT.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
AS OF 345 PM EDT SUNDAY...
TAIL END OF COLD FRONT AND ASSOCIATED CONVECTION WILL BE EXITING
THE AREA JUST AFT 00Z. HOWEVER...A BROAD UPPER TROUGH...ALMOST
WINTERLIKE PATTERN CONTINUES TO EVOLVE AND DEEPEN ACROSS THE
GREAT LAKES WITH NUMEROUS SPOKES OF PVA/SHORT WAVES REMAINING
UPSTREAM. THIS LEAVES THE REGION...ESPECIALLY THE MOUNTAINS...WITH
A VERY UNSETTLED PATTERN. AT A MINIMUM...EXPECT VARIABLE
CLOUDINESS. TIMING OF EMBEDDED DISTURBANCES WILL BE THE KEY TO THE
TIMES FOR THE BETTER CHANCES OF SHOWERS. FOR SEVERAL DAYS...THE
GFS HAS INSISTED ON A SIGNIFICANT DISTURBANCE MOVING THROUGH THE
REGION WED WITH WIDESPREAD -SHRA AS A RESULT. THE OTHER MODELS
REMAIN LACKLUSTER WITH THIS FEATURE...BUT DO SUGGEST AT LEAST SOME
SMALL CHANCE WITHIN THIS TIME FRAME. GIVEN THE UNSETTLED NATURE OF
THE PATTERN WITH UPSLOPE FLOW AND VERY DIFFICULT TO TIME UPPER
DISTURBANCES...CANNOT REALLY DROP POPS AT ANY TIME. BEST FOCUS
THROUGH THE PERIOD WILL REMAIN WEST OF THE BLUE RIDGE...AND
ESPECIALLY ACROSS THE MOUNTAINS OF WV/FAR SW VA. IN
ADDITION...ENOUGH INSTABILITY SUGGESTED WITH COLD AIR ALOFT...TO
INTRODUCE ISOLD TSRA WITH THE WED DISTURBANCE AS WELL.
850MB TEMPS DROP TO NEAR 0C ACROSS THE NORTHERN PART OF THE
FORECAST AREA BY WED...BUT THE BETTER COLD ADVECTION COMES IN THE
EXTENDED PERIOD BEHIND THE WED DISTURBANCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...
BROAD UPPER TROUGH REMAINS IN PLACE AND DOMINATES THE EXTENDED
FORECAST...GRADUALLY SHIFTING FURTHER ESE LATE IN THE PERIOD.
THIS KEEPS THE REGION IN AN UNSTABLE/UNSETTLED NORTHWEST FLOW WITH
NUMEROUS EMBEDDED SHORT WAVES. MODELS VARY CONSIDERABLY AS TO THE
TIMING AND PLACEMENT OF THESE DISTURBANCES...BUT ENOUGH AGREEMENT
THAT POPS CANNOT BE DROPPED REALLY AT ANY TIME THE OVERALL TREND
IS TO PUSH THE BETTER MOISTURE FURTHER SOUTH OF THE REGION AS THE
WEEK PROGRESSES AND 850MB TEMPS DROP BELOW 0C IN THE NORTHERN
COUNTIES. THE ENTIRE PERIOD SHOULD FEATURE BELOW NORMAL
TEMPERATURES WITH LOW CHC POPS...HIGHEST ACROSS THE MOUNTAINS AND
TOWARD THE SOUTHERN COUNTIES...WITH THE NORTHERN PIEDMONT THE
DRIEST. ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL THROUGHOUT THE
PERIOD...NO REAL CLEAR CONCERN AT THIS POINT FOR FROST/FREEZE
BECAUSE OF CYCLONIC FLOW AND CLOUDS.
&&
.AVIATION /05Z MONDAY THROUGH FRIDAY/...
AS OF 110 AM EDT MONDAY...
BULK OF THE RAIN IS HEADING NORTH OF THE AREA WITH THE WIND BECOMING
SOUTHWESTERLY. VISIBILITIES WILL IMPROVE QUICKLY AS LIGHT RAIN
TRACKS TO THE NORTH BY 08Z...THEN CEILINGS WILL LIFT TO VFR
WITHIN A COUPLE OF HOURS AFTER...DEFINITELY BY 12Z MONDAY.
SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE REGION MONDAY
AFTERNOON...FOLLOWED BY A COLD FRONT. PRESSURE RISES BEHIND THE
FRONT WILL BRING BREEZY AND GUSTY WESTERLY WINDS TO THE AREA INTO
MONDAY NIGHT.
EXTENDED AVIATION...
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...KK/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/KK/RCS
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 400 AM CDT MON APR 20 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF
STRENGTHENING LOW PRESSURE MOVING NORTH OVER SOUTHWEST LOWER
MICHIGAN. COMMA HEAD PRECIP AROUND THE LOW IS NOW SHIFTING
NORTHWEST AND EXTENDS FROM WAUTOMA TO WAUSAUKEE. FARTHER
WEST...MID-LEVEL FRONTOGENESIS IS CREATING A BAND OF RAIN OVER
WESTERN WISCONSIN AHEAD OF AN UPPER TROUGH POSITIONED OVER
SOUTH-CENTRAL CANADA AND THE NORTHERN PLAINS. WINDS SHIFT TO THE
NORTHWEST OVER WESTERN WISCONSIN AND ARE GUSTING INTO THE LOWER 30
KTS. SOME SNOW BEING REPORTED OVER NORTHERN MINNESOTA AS WELL. AS
THE LOW CONTINUES TO LIFT TO THE NORTH AND THE UPPER TROUGH SETTLES
OVER THE GREAT LAKES...PRECIP TRENDS ARE THE MAIN FORECAST CONCERN.
TODAY...THE LOW PRESSURE SYSTEM WILL TRAVEL NORTHWARD OVER WESTERN
LOWER MICHIGAN INTO NORTHERN ONTARIO. MODELS INDICATE THAT COMMA
HEAD PRECIP ASSOCIATED WITH THE LOW WILL LIFT NORTH ACROSS THE
CENTRAL FORECAST AREA EARLY THIS MORNING AND ACROSS THE CENTRAL UPPER
PENINSULA LATER IN THE MORNING. MEANWHILE...THE FGEN INDUCED RAIN
BAND WILL PIVOT NORTHEAST ACROSS CENTRAL AND NORTH-CENTRAL WISCONSIN
THIS MORNING AND NORTHEAST WISCONSIN THIS AFTERNOON. THEREFORE
EXPECT PERIODS OF RAIN THROUGH THE MORNING...BEFORE THE RAIN
GRADUALLY EXITS TO THE NORTHEAST IN THE AFTERNOON.
ADDITIONALLY...WEST WINDS WILL DRIVE COLDER AIR ACROSS THE STATE
BEHIND THE SYSTEM WHICH WILL STEEPEN LOW LEVEL LAPSE RATES...AND
PROMOTE GUSTY WINDS DEVELOPING. SOME GUSTS OVER CENTRAL AND
EAST-CENTRAL WISCONSIN COULD EXCEED 30 MPH THIS AFTERNOON. WITH THE
RAIN AND CLOUDS...COOLER HIGHS IN THE MID 40S TO AROUND 50.
TONIGHT...MID-LEVEL DRY SLOTTING WILL BE ROTATING OVERHEAD DURING
THE EVENING BEFORE DEEPER MOISTURE RETURNS AS UPPER LEVEL LOW
PRESSURE SETTLES ACROSS THE REGION. MOISTURE WILL BE THE DEEPEST
OVER FAR NORTH-CENTRAL WISCONSIN FOR THE EVENING HOURS...WHERE WILL
CARRY LOW CHANCES OF PRECIP. THEN PRECIP CHANCES WILL INCREASE FROM
NORTHWEST TO SOUTHEAST THROUGH THE OVERNIGHT. SOUNDINGS COOL ENOUGH
OVERNIGHT FOR SNOW TO BECOME THE DOMINANT PTYPE OVER CENTRAL AND
NORTH-CENTRAL WISCONSIN FOR MINOR ACCUMULATIONS ON GRASSY SURFACES.
LOWS RANGING FROM THE LOW TO MID 30S.
TUESDAY...WITH UPPER LEVEL LOW PRESSURE OVERHEAD...PERIODS OF RAIN
AND SNOW SHOWERS LOOK TO OCCUR OVER NORTH-CENTRAL WISCONSIN. MINOR
SNOW ACCUMULATIONS ARE POSSIBLE ACROSS THE NORTH DURING THE
MORNING. CHANCES OF PRECIP WILL IMPROVE THROUGH THE MORNING OVER
EASTERN WISCONSIN WHERE PRECIP COULD BE A MIX OF RAIN AND SNOW
INITIALLY BEFORE TEMPS RISE WARM ENOUGH FOR ALL RAIN. COOL WITH
HIGHS RANGING FROM NEAR 40 NORTH TO THE UPPER 40S SOUTHEAST.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 400 AM CDT MON APR 20 2015
UPPER LOW ACROSS ONTARIO WILL GRADUALLY SHIFT EAST INTO QUEBEC BY
THE END OF THE WORK WEEK. COOL CYCLONIC FLOW WILL CONTINUE TO BRING
BELOW NORMAL TEMPERATURES INTO THE WEEKEND...ALONG WITH A CHANCE OF
RAIN OR SNOW SHOWERS AT TIMES TUESDAY NIGHT INTO THURSDAY. HIGHEST
CHANCES WILL BE ACROSS THE NORTH...IN CLOSER PROXIMITY TO THE UPPER
LOW AND SHORTWAVE ENERGY. CURRENT FORECAST IS DRY FOR FRIDAY...
BUT COULD NOT RULE OUT A STRAY RAIN/SNOW SHOWER ACROSS THE NORTH.
DRY CONDITIONS ARE EXPECTED THIS WEEKEND AS HIGH PRESSURE DOMINATES
THE WEATHER PATTERN. ONLY MINOR CHANGES MADE TO MAX/MIN TEMPERATURES
AND PRECIPITATION CHANCES.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1140 PM CDT SUN APR 19 2015
STEADY RAIN CONTINUES TO SPREAD OVER THE TAF SITES
EARLY THIS MORNING AS LOW PRESSURE LIFTS THROUGH THE CENTRAL
GREAT LAKES. THIS ACTIVITY WILL CAUSE CONDITIONS TO FALL TO
IFR...WITH LIFR CIGS POSSIBLE AT TIMES. RAIN WILL END FROM WEST
TO EAST LATER THIS MORNING AND DURING THE AFTERNOON HOURS AS THE
LOW LIFTS NORTH OVER WESTERN ONTARIO. CONDITIONS WILL EVENTUALLY
IMPROVE BACK TO VFR AS THE RAIN ENDS DURING THE AFTERNOON AND
EVENING HOURS. A TIGHT PRESSURE GRADIENT WILL LEAD TO GUSTY
WESTERLY WINDS SUNDAY AFTERNOON AS THE LOW LIFTS TO THE NORTH.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......KURIMSKI
AREA FORECAST DISCUSSION
NWS ALBANY NY
1031 AM EDT MON APR 20 2015
.SYNOPSIS...
OCCASIONAL PERIODS OF RAIN ARE EXPECTED ACROSS EASTERN
NEW YORK AND WESTERN NEW ENGLAND THIS AFTERNOON INTO TONIGHT...AS A
LOW PRESSURE SYSTEM TRACKS INTO THE GREAT LAKES...AND A
FRONTAL SYSTEM ASSOCIATED WITH THE LOW APPROACHES FROM THE WEST.
EAST TO SOUTHEAST WINDS WILL BECOME STRONG AND GUSTY TODAY AHEAD OF
THE SYSTEM. A FEW RUMBLES OF THUNDER WILL BE POSSIBLE TONIGHT AS THE
FRONT PASSES. SOME BREAKS IN THE CLOUDS WILL DEVELOP TUESDAY
AFTERNOON BEHIND THE FRONT...OTHERWISE GENERALLY COOL AND SOMEWHAT
UNSETTLED CONDITIONS WILL PERSIST THROUGH THE REMAINDER OF THE WEEK
...AS A LARGE UPPER LEVEL LOW REMAINS ANCHORED NORTH OF THE GREAT
LAKES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1030 AM EDT...THE SURGE OF WARM ADVECTION PRECIPITATION AHEAD
OF THE WARM OVER THE UPPER MID ATLANTIC REGION IS MOVING INTO THE
MID HUDSON VALLEY...SE CATSKILLS.. SRN TACONICS...SRN BERKS...AND
NW CT. SOME RAINFALL RATES ACROSS NRN NJ REACHED A QUARTER OF AN
INCH AN HOUR EARLIER THIS MORNING. NORTH OF THIS AREA...SCT
SHOWERS OR PERIODS OF LIGHT RAIN PERSIST. ONGOING FORECAST IS IN
PRETTY GOOD SHAPE WITH JUST SOME RETOOLING OF THE POPS...AND
HOURLY TEMPS BASED ON THE RADAR AND OBSERVATIONS TRENDS. THERE IS
GOOD SUPPORT FROM THE LATEST HRRR FOR THE PCPN TO EXPAND NORTHWARD
INTO THE CAPITAL REGION...NRN CATSKILLS...MOHAWK VALLEY...SRN VT
CORRIDOR. SOME DOWNSLOPING DUE TO THE STRONG E/SE LLJ MAY LIMIT
THE MODERATE RAINFALL EXPANSION INTO THE UPPER HUDSON REGION...AND
WEST OF THE SRN GREENS. THE HIGHER TOTALS OF A THIRD TO TWO THIRDS
OF AN INCH OF RAINFALL ARE EXPECTED SOUTH OF THE CAPITAL REGION.
THE STEADIER RAIN SHOULD TAPER TO SHOWERS AND SOME DRIZZLE FOR
THIS AFTERNOON AS THE LOW LEVEL JET AND STRONGEST ISENTROPIC LIFT
PASS NORTH AND EAST OF THE REGION. SOUTH/EAST FACING HIGHER
ELEVATIONS WILL BE MOST PRONE TO MORE PERSISTENT SHOWERS AND
DRIZZLE THIS AFTERNOON.
GUSTY EAST/SOUTHEAST WINDS HAVE DEVELOPED LATE THIS MORNING AS
THE LOW LEVEL JET AND TIGHT PRESSURE GRADIENT PASS THROUGH. SOME
GUSTS OF 30-40 MPH HAVE BEEN NOTED AT KDDH AND KAQW. THE BEST
CHANCE FOR STRONGER WINDS TO MIX DOWN WILL BE ACROSS HIGHER
TERRAIN OF THE TACONICS...SOUTHERN GREEN MTNS...AND
BERKSHIRES...WHERE SOME GUSTS OF 50-55 MPH MAY OCCUR...ESP FROM
THE LATE MORNING THROUGH EARLY AFTERNOON. WIND GUSTS OF 35-45 MPH
WILL ALSO BE LIKELY ACROSS PORTIONS OF THE WESTERN
ADIRONDACKS...MOHAWK VALLEY AND EASTERN CATSKILLS. IN MOST VALLEY
AREAS...SOME WIND GUSTS OF 25-35 MPH COULD OCCUR EARLY THIS
MORNING AS THE RAIN INITIALLY REACHES THE GROUND. HOWEVER...THE
BOUNDARY LAYER SHOULD THEN STABILIZE ONCE WET BULB COOLING
OCCURS INTO THE AFTERNOON...DIMINISHING THE THREAT OF STRONGER
WINDS MIXING DOWN TO THE VALLEY FLOOR.
TEMPS WILL MAINLY BE IN THE 40S TO ABOUT 50F OVER THE HIGHER
TERRAIN...AND LOWER TO MID 50S IN THE VALLEY AREAS...EXCEPT IN THE
UPPER HUDSON REGION/LAKE GEORGE REGION AND PARTS OF SRN VT WHERE
SOME OF THE MAX TEMPS MAY ONLY REACH THE UPPER 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...A WARM FRONT WILL SLOWLY ATTEMPT TO LIFT NORTHWARD FROM
THE MID ATLANTIC STATES...AS A COLD/OCCLUDED FRONT APPROACHES FROM
THE GREAT LAKES REGION. ALTHOUGH THE PARENT LOW IS EXPECTED TO
TRACK ACROSS THE GREAT LAKES REGION TONIGHT...A WEAK TRIPLE POINT
LOW MAY FORM ALONG THE JUNCTION OF THE RETREATING WARM FRONT...AND
APPROACHING COLD FRONT FROM THE WEST...SOMEWHERE OVER SOUTH
CENTRAL PA. MODELS SUGGEST THAT SOME ELEVATED INSTABILITY...WITH
SHOWALTER INDICES DIPPING INTO THE -1C TO -3C RANGE OVERSPREADS AT
LEAST THE WESTERN AND SOUTHERN HALF OF THE REGION
OVERNIGHT...WHICH...IN COMBINATION WITH SYNOPTIC LIFT AHEAD OF THE
APPROACHING FRONTS...AND SOME QG FORCING AHEAD OF AN VORT LOBE
APPROACHING FROM THE SOUTHWEST...MAY ALLOW FOR A ROUND OF ELEVATED
CONVECTION LATER THIS EVENING AND OVERNIGHT...ESP FOR AREAS NEAR
AND SOUTH OF INTERSTATE 90. SO...SOME RUMBLES OF THUNDER ARE NOT
OUT OF THE QUESTION. ANY THUNDERSTORMS ARE EXPECTED TO REMAIN
NON-SEVERE ACROSS OUR REGION...WHICH IS IN AGREEMENT WITH LATEST
SPC DAY 1 OUTLOOK...WHICH KEEPS OUR AREA IN THE GENERAL THUNDER
REGION. HOWEVER...ANY THUNDERSTORMS THAT OCCUR OVERNIGHT COULD
HAVE LOCALLY HEAVY DOWNPOURS. TEMPS ARE EXPECTED TO HOLD NEARLY
STEADY MOST OF THE NIGHT...BEFORE FALLING INTO THE 40S CLOSER TO
DAYBREAK.
TUESDAY...SOME LINGERING SHOWERS WILL BE POSSIBLE IN THE MORNING
AS THE AFOREMENTIONED VORT LOBE SWINGS ACROSS. THEN...IT APPEARS
THAT OUR REGION WILL EXPERIENCE A PERIOD OF SUBSIDENCE IN THE
AFTERNOON HOURS...WHEN SOME BREAKS OF SUN COULD OCCUR. SOME LOW
LEVEL INSTABILITY COULD ALLOW FOR ISOLATED SHOWERS TO DEVELOP
LATER IN THE AFTERNOON...MAINLY ACROSS THE WESTERN ADIRONDACK
REGION. MAX TEMPS ARE FORECAST TO REACH THE LOWER/MID 60S IN
VALLEY AREAS AND 50S ACROSS HIGHER ELEVATIONS.
TUE NT-WED...ANOTHER REINFORCING COLD FRONT AND UPPER LEVEL
SHORTWAVE ARE EXPECTED TO CROSS THE REGION ON WED. WEAK RIDGING
JUST AHEAD OF THIS FEATURE MAY ALLOW FOR SOME BREAKS IN THE CLOUDS
TO CONTINUE INTO EARLY TUE NT...BEFORE CLOUDS REDEVELOP...AND
SHOWERS OVERSPREAD THE REGION DURING WED. BOUNDARY LAYER TEMPS MAY
BECOME QUITE CHILLY TUE NT/WED AM IF ENOUGH BREAKS IN THE CLOUDS
CAN DEVELOP...WITH WIDESPREAD LOW TEMPS IN THE 30S. ON
WED...DEPENDING ON THE TIMING OF SHOWER DEVELOPMENT...MAX TEMPS
COULD BRIEFLY REACH THE UPPER 50S TO LOWER 60S IN VALLEYS...BEFORE
FALLING ONCE SHOWERS OCCUR. FOR HIGHER ELEVATIONS...ONLY 40S ARE
EXPECTED. IN FACT...SOME WET SNOW AND/OR GRAUPEL COULD OCCUR
ACROSS THE SOUTHERN ADIRONDACKS AND HIGHER ELEVATIONS ACROSS THE
CATSKILLS AND WESTERN NEW ENGLAND BY LATE WED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
BELOW NORMAL TEMPERATURES AND INTERVALS OF SHOWERS AND SNOW SHOWERS
AS LARGE UPPER LOW AND ASSOCIATED EASTERN NORTH AMERICAN UPPER
TROUGHING CONTROLS THE WEATHER. THERE IS A GOOD CONSENSUS ON THE
LARGE SCALE UPPER LOW AND UPPER TROUGH BUT DISAGREEMENT ON THE TRACK
AND TIMING OF SMALL PIECES OF UPPER ENERGY ROTATING AROUND THE
PERIPHERY OF THE UPPER LOW...SOME OF WHICH ARE EXPECTED TO TRACK
THROUGH OR NEAR OUR REGION. SINCE THE CENTER OF THE UPPER LOW IS
EXPECTED TO TRACK NORTH OF THE REGION...OR ACROSS OUR NORTHERN
PORTION OF THE FORECAST AREA...THE DEEP FLOW ACROSS OUR REGION
SHOULD BE WEST...WHICH TYPICALLY RESULTS ISOLATED TO SCATTERED
COVERAGE OF SHOWERS AND SNOW SHOWERS. THE BEST COVERAGE ALSO IS
TYPICALLY IN LEE OF LAKE ONTARIO INTO THE SOUTHERN ADIRONDACKS AND
WESTERN MOHAWK VALLEY...AND ALSO INTO THE SOUTHERN GREEN MOUNTAINS
TO NORTHERN TACONICS DUE TO SOME UPSLOPE...BUT AGAIN JUST
SCATTERED.
DAYTIME PRECIPITATION TYPE LOOKS TO BE JUST RAIN SHOWERS...BUT
NIGHTTIME COULD SEE SOME SNOW SHOWER ACTIVITY...ESPECIALLY IN HIGHER
ELEVATIONS. THERE ARE ALSO HINTS AT SOME UPPER ENERGY POSSIBLY
INTERACTING WITH THE SOUTHERN STREAM NEXT WEEKEND THAT COULD SUPPORT
MORE ORGANIZED LOW PRESSURE AND MORE ORGANIZED PRECIPITATION...WITH
COLDER THAN NORMAL TEMPERATURES IN PLACE...WILL JUST WATCH
CAREFULLY.
NOT GETTING TO SPECIFIC ON TIMING OF INTERVALS OF SHOWERS/SNOW
SHOWERS DUE TO THE INCONSISTENCIES IN THE FINE DETAILS IN SOURCES OF
GUIDANCE...BUT THERE WILL BE PERIODS OF DRY WEATHER EVEN WITH THE
DOMINANCE OF ISOLATED TO SCATTERED SHOWERS/SNOW SHOWERS IN THE
FORECAST. THERE WILL ALSO BE SOME INTERVALS OF BREAKS IN THE CLOUDS
AND AGAIN...TRYING TO BROADBRUSH TIMING OF ANY CLOUDINESS VERSUS
BREAKS IN THE CLOUDS. HIGHS THURSDAY THROUGH SUNDAY LOOK TO BE IN
THE LOWER TO MID 50S...BUT 40S HIGHER ELEVATIONS...AND MAYBE BARELY
40 IN SOME PARTS OF THE SOUTHERN ADIRONDACKS. LOWS IN THE 20S AND
30S AT NIGHT WITH COLDEST TEMPERATURES IN HIGHER ELEVATIONS.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AN APPROACHING WARM FRONT AND A LOW PRESSURE SYSTEM WILL BRING A
WIDESPREAD SOAKING RAINFALL TO THE REGION FROM THIS MORNING
THROUGH TONIGHT.
VFR/LOW MVFR CONDITIONS SHOULD PERSIST THROUGH THE LATE
MORNING...AS RAIN HAS BEEN LIGHT AND THE ATMOSPHERE IS STILL
TAKING SOME TIME TO MOISTEN. CIGS WILL GRADUALLY LOWER...BUT
SHOULD REMAIN VFR THROUGH 14Z-16Z THIS MORNING. OCCASIONAL LIGHT
TO MODERATE RAIN SHOULD PREVAIL AFTER 14Z-16Z. RAIN INTENSITY
SHOULD WEAKEN BY MID TO LATE AFTERNOON BUT OCCASIONAL LIGHT RAIN
IS EXPECTED TO CONTINUE. CONDITIONS WILL GENERALLY DETERIORATE TO
MVFR ALTHOUGH SOME BRIEF IFR IS POSSIBLE BEFORE 00Z TUESDAY. AFTER
00Z... CEILINGS WILL CONTINUE TO LOWER TOWARD IFR BUT ENOUGH
UNCERTAINTY TO JUST INDICATE SCATTERED LAYER BELOW 1000 FEET WITH
CEILINGS AROUND 1000 FEET BETWEEN 00Z-12Z. VISIBILITIES WILL
CONTINUE MVFR WITH PERIODS OF LIGHT RAIN THROUGH THIS EVENING.
LOW LEVEL WIND SHEAR /LLWS/ IS EXPECTED AT KPSF/KPOU AND KGFL
THROUGH THE DAY AND WAS BEGUN AT 12Z...AS A STRONG SOUTHEAST JET
ALOFT MOVES OVERHEAD. SURFACE WINDS SHOULD BE STRONGER AND
OCCASIONALLY GUSTY AT KALB...SO WILL LEAVE OUT MENTION OF LLWS FOR
NOW. LLWS SHOULD END BY 00Z AS THE LOW LEVEL JET SEGMENT EXITS THE
REGION.
SURFACE WINDS WILL BE EAST-SOUTHEAST AROUND 10-16 KT BY THE LATE
MORNING. GUSTS COULD EXCEED 20-25 KT... ESPECIALLY AT KALB/KPSF.
WINDS REMAIN EAST TO SOUTHEAST THIS EVENING BUT DIMINISH TO 10 KT
OR LESS. WINDS WILL SHIFT TO SOUTHWEST AT 6 KT OR LESS LATER
TONIGHT.
OUTLOOK...
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
THURSDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
&&
.FIRE WEATHER...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THE AREA TODAY AND
TONIGHT...WITH RAINFALL AMTS OF 0.75-1.5 INCHES EXPECTED. THE
WEATHER WILL BE COOL AND UNSETTLED FOR MUCH OF THE WEEK.
&&
.HYDROLOGY...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THE AREA TODAY AND
TONIGHT. EXPECTING WIDESPREAD QPF AMOUNTS OF AROUND AN INCH WITH
HIGHER AMOUNTS UP TO AROUND 1.5 INCHES WHERE THE RAINFALL IS
ENHANCED BY THE STRONG EAST TO SOUTHEAST FLOW...PARTICULARLY
ACROSS THE CENTRAL AND SOUTHEASTERN CATSKILLS...TACONICS...BERKSHIRES
INTO THE LITCHFIELD HILLS AND ACROSS SOUTHERN VERMONT. LOCALIZED
HIGHER AMOUNTS OF 2 TO 3 INCHES WILL BE POSSIBLE.
THERE IS STILL SOME SNOW COVER LEFT IN THE FORECAST AREA. BASED
ON NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER (NOHRSC)
THIS IS ACROSS THE PORTIONS OF THE WESTERN ADIRONDACKS AND ACROSS
THE HIGHER TERRAIN OF THE SOUTHERN GREEN MOUNTAINS.
BASED ON CURRENT FORECASTS...ONLY THE SCHOHARIE CREEK AT GILBOA
DAM IS FORECAST TO REACH ITS FLOOD STAGE AND THE WEST CANADA CREEK
AT HINCKLEY DAM TO EXCEED ITS FLOOD STAGE BOTH BY TUESDAY EVENING.
THE REST OF THE WEEK THE FORECAST WILL BE DOMINATED BY A PERSISTENT
UPPER LEVEL TROUGH WHICH WILL RESULT IN COOL TEMPERATURES...BREEZY
CONDITIONS AND OCCASIONAL CHANCES FOR MAINLY LIGHT PRECIPITATION.
FOR DETAILS ON SPECIFIC AREA RIVER AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB-
SITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NYZ054-061.
MA...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR MAZ001-025.
VT...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR VTZ013-014.
&&
$$
SYNOPSIS...IAA/KL/WASULA
NEAR TERM...KL/WASULA
SHORT TERM...KL
LONG TERM...NAS
AVIATION...NAS/JPV
FIRE WEATHER...IAA/KL
HYDROLOGY...IAA/KL
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1035 AM EDT MON APR 20 2015
.DISCUSSION...
...STRONG TO ISOLATED SEVERE STORMS POSSIBLE THIS AFTERNOON AND
EVENING...
LATEST RADAR AND LIGHTNING IMAGERY SHOWS SQUALL LINE OVER THE NRN
AND CENTRAL GULF SHIFTING EASTWARD OUT AHEAD OF WEAK FRONT MOVING
INTO THE SOUTHEAST STATES. TRACK ESTIMATES HAS THIS LINE NEARING THE
WEST CENTRAL FL COAST BY EARLY THIS AFT. MID/HIGH LEVEL DEBRIS
CLOUDS FROM THIS CONVECTION ALREADY MOVING ACROSS THE REGION WHICH
WILL LIMIT DAYTIME HEATING TODAY. HOWEVER SHOULD STILL SEE ENOUGH
FILTERED SUNSHINE FOR HIGHS TO REACH THE MID TO UPPER 80S INTO
EARLY/MID AFT. DECENT HEATING...DEEP MOISTURE AND MARGINALLY
FAVORABLE DYNAMIC SUPPORT FROM SUBTROPICAL JET MAY ALLOW THIS LINE
TO MAINTAIN ENOUGH STRENGTH TO HOLD TOGETHER AS IT INITIALLY MOVES
ONSHORE. THE POTENTIAL FOR STRONG TO ISO SEVERE WIND GUSTS WILL
ACCOMPANY THIS CONVECTIVE BAND AS IT MOVES TOWARD LAKE COUNTY AND I-
4 CORRIDOR. STORM PREDICTION CENTER HAS PLACED THIS REGION UNDER A
SLIGHT RISK IN THE LATEST DAY 1 UPDATE. IN ADDITION TO WIND...HAIL
UP TO QUARTER SIZE WILL ALSO BE A CONCERN AS MORNING SOUNDINGS SHOW
COOLER TEMPS ALOFT WITH -10 TO -12C AT 500MB.
IN ADDITION TO THIS LINE...HRRR/WRF MODELS SHOW ADDITIONAL SCT-NMRS
SHOWERS AND STORMS DEVELOPING OUT AHEAD OF THIS SYSTEM AND PUSHING E-
NE ACROSS THE AREA INTO THE AFT HOURS. THESE STORMS COULD ALSO BRING
WITH THEM THREAT FOR STRONG WIND GUSTS AND SMALL HAIL...ESPECIALLY
WITH BOUNDARY INTERACTIONS TOWARD THE COAST IF THE EAST COAST SEA
BREEZE IS ABLE TO FORM. THEREFORE HIGH POPS UP TO 70-80 PERCENT
TODAY STILL LOOK GOOD WITH NO MAJOR CHANGES TO THE FORECAST PLANNED.
&&
.AVIATION...VFR THROUGH THE MORNING. INCREASING COVERAGE OF
SHRA/TSRA INTO THE AFT WITH APPROACHING SQUALL LINE OVER THE GULF
AND ADDITIONAL SCT-NMRS CONVECTION THAT FORMS OUT AHEAD OF THIS LINE
THAT BOTH THE WRF AND HRRR MODELS INDICATE. STRONG TO ISO SEVERE
WIND GUSTS AND HAIL POSSIBLE WITH ANY STORMS TODAY. TEMPO IFR/MVFR
CONDS WILL OCCUR WITH ANY CONVECTION TODAY WITH BEST TIMEFRAME FOR
THIS ACTIVITY BTW 18-00Z.
&&
.MARINE...
TODAY-TONIGHT...(PREVIOUS DISCUSSION) SOUTH TO SOUTHWEST WINDS
AROUND 10 KNOTS NEARSHORE AND 10 TO 15 KNOTS OFFSHORE. SEAS 2 TO 3
FEET NEARSHORE AND 3 TO 4 FEET WELL OFFSHORE. SCATTERED TO NUMEROUS
AFTERNOON WEST TO EAST MOVING SHOWERS AND STORMS. FAST MOVING...20
TO 30 MPH...STORMS AGAIN. BOATERS SHOULD KEEP AN EYE TO THE WEST FOR
FAST APPROACHING STORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 85 67 81 62 / 80 50 20 10
MCO 86 67 86 68 / 80 50 30 20
MLB 87 68 82 70 / 80 50 40 20
VRB 88 69 82 69 / 70 50 40 20
LEE 85 67 84 67 / 80 40 20 20
SFB 86 67 85 65 / 80 50 20 20
ORL 86 68 85 68 / 80 50 30 20
FPR 88 69 83 69 / 70 50 50 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
WEITLICH/KELLY
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1025 AM CDT MON APR 20 2015
.UPDATE...
ISSUED AT 1022 AM CDT MON APR 20 2015
LITTLE CHANGE NEEDED TO THE PREVIOUS FORECAST. SHOWERS HAVE
LARGELY EXITED THE AREA...AND EARLIER CLEARING TREND ACROSS WEST
CENTRAL ILLINOIS HAS BEEN FILLING IN WITH DIURNAL CLOUDS. HIGH-RES
MODEL GUIDANCE SHOWING POTENTIAL FOR SOME LIGHT REDEVELOPMENT
THROUGH THE DAY...WHICH CURRENTLY IS SEEN IN CENTRAL IOWA MOVING
SOUTHEAST. WITH STRONG COLD AIR ADVECTION AND NORTHWEST WINDS
GUSTING 30-40 MPH...HAVE LOWERED AFTERNOON TEMPERATURES BY A
COUPLE DEGREES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT MON APR 20 2015
07Z/2AM WATER VAPOR IMAGERY SHOWS LONG-WAVE TROUGH AXIS EXTENDING
FROM MINNESOTA TO NORTHERN TEXAS, WITH VIGOROUS SHORT-WAVE NOTED ON
ITS EAST SIDE OVER SOUTHEAST MISSOURI. WITH MAIN WAVE STILL TO THE
WEST, SCATTERED SHOWERS ARE ONGOING ACROSS CENTRAL ILLINOIS EARLY
THIS MORNING. AS SOUTHEAST MISSOURI WAVE TRACKS INTO THE OHIO RIVER
VALLEY, THINK AREAL COVERAGE OF SHOWERS WILL DIMINISH AFTER SUNRISE,
WITH LITTLE OR NO PRECIP OCCURRING FOR THE BALANCE OF THE MORNING.
DESPITE LOW-LEVEL DRYING IN THE WAKE OF THIS FEATURE, SYNOPTIC-SCALE
CYCLONIC FLOW ALOFT WILL LEAD TO STEEP LAPSE RATES AND PERHAPS A FEW
SHOWERS FROM LATE MORNING INTO THE AFTERNOON. MOST MODEL GUIDANCE
REMAINS DRY: HOWEVER, BOTH THE HRRR AND 4KM WRF-NMM SUGGEST AT LEAST
ISOLATED SHOWERS AS THE ATMOSPHERE DESTABILIZES. WILL CARRY SLIGHT
CHANCE POPS ACROSS THE BOARD TO COVER THIS POSSIBILITY. COLD FRONT
CURRENTLY APPROACHING THE I-55 CORRIDOR WILL SWEEP EASTWARD THIS
MORNING AND EXIT INTO INDIANA BY MIDDAY. STRONG/GUSTY WINDS WILL
DEVELOP BEHIND THE FRONT AS PRESSURE GRADIENT TIGHTENS. LATEST OBS
ARE ALREADY SHOWING GUSTS IN THE 25 TO 30MPH RANGE AND THINK MIXING
OF HIGHER MOMENTUM AIR ALOFT WILL RESULT IN GUSTS OF 30 TO 35MPH
DURING THE DAY. HIGH TEMPERATURES WILL BE IN THE UPPER 50S AND
LOWER 60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 AM CDT MON APR 20 2015
A COOL AND MOSTLY DRY WEEK IS ON TAP ACROSS CENTRAL ILLINOIS, WITH
THE NEXT SIGNIFICANT CHANCE FOR RAIN LIKELY HOLDING OFF UNTIL NEXT
WEEKEND. A DEEP UPPER LOW OVER THE GREAT LAKES WILL BE THE DOMINANT
WEATHER FEATURE EARLY IN THE PERIOD, KEEPING THE MIDWEST LOCKED IN A
NORTHWESTERLY FLOW PATTERN. THANKS TO A TIGHTENING PRESSURE
GRADIENT AHEAD OF AN APPROACHING COLD FRONT, STRONG WESTERLY WINDS
WILL ONCE AGAIN DEVELOP ON TUESDAY. NUMERIC GUIDANCE AND FORECAST
SOUNDINGS BOTH SUGGEST GUSTS REACHING 30 TO 35MPH AT TIMES. THE
FRONT WILL PASS THROUGH THE AREA TUESDAY NIGHT INTO WEDNESDAY
MORNING: HOWEVER, DEEP-LAYER MOISTURE WILL BE LACKING, SO PRECIP
CHANCES WILL REMAIN NEGLIGIBLE. WILL ONLY CARRY LOW CHANCE POPS
ACROSS THE SOUTHERN KILX CWA AS THE FRONT PASSES. AN EVEN COOLER
AIRMASS WILL ARRIVE FOR THE MIDDLE AND END OF THE WEEK BEHIND THE
DEPARTING FRONT, WITH HIGHS DROPPING INTO THE UPPER 50S/LOWER 60S
FOR WEDNESDAY THROUGH FRIDAY. OVERNIGHT LOWS WILL DIP INTO THE 30S,
WITH THE BEST POTENTIAL FOR FROST LIKELY SETTING UP FOR WEDNESDAY
NIGHT AND THURSDAY NIGHT AS SKIES REMAIN CLEAR AND WINDS DIMINISH.
FURTHER OUT, MAJOR MODEL DISCREPANCIES HAVE DEVELOPED CONCERNING THE
NEXT POTENTIAL SYSTEM FOR THE END OF THE WEEK. THE 00Z APR 20 GFS
HAS MADE A MAJOR SHIFT FROM ITS PREVIOUS RUNS AND NOW SHOWS RAIN
SPREADING INTO CENTRAL ILLINOIS FROM AN APPROACHING UPPER LOW AS
EARLY AS FRIDAY. MEANWHILE, BOTH THE ECMWF AND GEM ARE MUCH SLOWER,
WITH RAIN NOT ARRIVING UNTIL LATE FRIDAY NIGHT INTO SATURDAY. GIVEN
INITIAL PRESENCE OF A STRONG RIDGE AXIS ACROSS THE MIDWEST, THINK
THE RAPID PROGRESSION OF RAIN INTO THE DRY AIRMASS SEEMS SUSPECT.
IN ADDITION, THE SLOWER ECMWF/GEM HAVE MAINTAINED GOOD CONSISTENCY
WITH THEIR EARLIER RUNS. AS A RESULT, HAVE REJECTED THE GFS IN
FAVOR OF THE ECMWF/GEM CONSENSUS FOR THE END OF THE WEEK. HAVE
THEREFORE KEPT FRIDAY DRY, THEN HAVE INTRODUCED POPS MAINLY ACROSS
THE CENTRAL AND SOUTHERN CWA FRIDAY NIGHT INTO SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 630 AM CDT MON APR 20 2015
CLOUDS OVER THE TAF SITES ARE AT MVFR LEVELS, EXCEPT FOR BMI THAT
IS AT IFR RIGHT NOW. BELIEVE THAT BMI WILL IMPROVE TO LOWER MVFR
SOON, BUT STILL HAVE A TEMPO GROUP FOR A COUPLE HOURS TO COVER.
MVFR CIGS WILL CONTINUE THIS MORNING. SATELLITE TRENDS SHOW
CLEARING TO THE WEST OF SPI, BUT BELIEVE ONCE SUN GETS LITTLE
HIGHER, CU/SC WILL DEVELOP QUICKLY, KEEPING CLOUDS OVER SPI LATE
THIS MORNING. HIRES MODELS CONTINUE TO SHOW SCATTERED SHOWERS
DEVELOPING TO THE WEST AND MOVING INTO THE AREA. AGREE WITH THIS
FORECAST SO HAVE INCLUDED VCSH AT ALL TAF SITES FOR THIS
AFTERNOON. CLOUDS AND PCPN WILL BE DIURNAL, SO SKIES SHOULD CLEAR
JUST AFTER SUNSET. BIGGEST ISSUE WILL BE THE GUSTY WEST WINDS.
WILL HAVE GUSTS TO 25-28KTS THIS MORNING, BUT THEN INCREASE TO
30KTS FOR THIS AFTERNOON. WINDS WILL DIMINISH THIS EVENING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
630 AM CDT MON APR 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT MON APR 20 2015
07Z/2AM WATER VAPOR IMAGERY SHOWS LONG-WAVE TROUGH AXIS EXTENDING
FROM MINNESOTA TO NORTHERN TEXAS, WITH VIGOROUS SHORT-WAVE NOTED ON
ITS EAST SIDE OVER SOUTHEAST MISSOURI. WITH MAIN WAVE STILL TO THE
WEST, SCATTERED SHOWERS ARE ONGOING ACROSS CENTRAL ILLINOIS EARLY
THIS MORNING. AS SOUTHEAST MISSOURI WAVE TRACKS INTO THE OHIO RIVER
VALLEY, THINK AREAL COVERAGE OF SHOWERS WILL DIMINISH AFTER SUNRISE,
WITH LITTLE OR NO PRECIP OCCURRING FOR THE BALANCE OF THE MORNING.
DESPITE LOW-LEVEL DRYING IN THE WAKE OF THIS FEATURE, SYNOPTIC-SCALE
CYCLONIC FLOW ALOFT WILL LEAD TO STEEP LAPSE RATES AND PERHAPS A FEW
SHOWERS FROM LATE MORNING INTO THE AFTERNOON. MOST MODEL GUIDANCE
REMAINS DRY: HOWEVER, BOTH THE HRRR AND 4KM WRF-NMM SUGGEST AT LEAST
ISOLATED SHOWERS AS THE ATMOSPHERE DESTABILIZES. WILL CARRY SLIGHT
CHANCE POPS ACROSS THE BOARD TO COVER THIS POSSIBILITY. COLD FRONT
CURRENTLY APPROACHING THE I-55 CORRIDOR WILL SWEEP EASTWARD THIS
MORNING AND EXIT INTO INDIANA BY MIDDAY. STRONG/GUSTY WINDS WILL
DEVELOP BEHIND THE FRONT AS PRESSURE GRADIENT TIGHTENS. LATEST OBS
ARE ALREADY SHOWING GUSTS IN THE 25 TO 30MPH RANGE AND THINK MIXING
OF HIGHER MOMENTUM AIR ALOFT WILL RESULT IN GUSTS OF 30 TO 35MPH
DURING THE DAY. HIGH TEMPERATURES WILL BE IN THE UPPER 50S AND
LOWER 60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 AM CDT MON APR 20 2015
A COOL AND MOSTLY DRY WEEK IS ON TAP ACROSS CENTRAL ILLINOIS, WITH
THE NEXT SIGNIFICANT CHANCE FOR RAIN LIKELY HOLDING OFF UNTIL NEXT
WEEKEND. A DEEP UPPER LOW OVER THE GREAT LAKES WILL BE THE DOMINANT
WEATHER FEATURE EARLY IN THE PERIOD, KEEPING THE MIDWEST LOCKED IN A
NORTHWESTERLY FLOW PATTERN. THANKS TO A TIGHTENING PRESSURE
GRADIENT AHEAD OF AN APPROACHING COLD FRONT, STRONG WESTERLY WINDS
WILL ONCE AGAIN DEVELOP ON TUESDAY. NUMERIC GUIDANCE AND FORECAST
SOUNDINGS BOTH SUGGEST GUSTS REACHING 30 TO 35MPH AT TIMES. THE
FRONT WILL PASS THROUGH THE AREA TUESDAY NIGHT INTO WEDNESDAY
MORNING: HOWEVER, DEEP-LAYER MOISTURE WILL BE LACKING, SO PRECIP
CHANCES WILL REMAIN NEGLIGIBLE. WILL ONLY CARRY LOW CHANCE POPS
ACROSS THE SOUTHERN KILX CWA AS THE FRONT PASSES. AN EVEN COOLER
AIRMASS WILL ARRIVE FOR THE MIDDLE AND END OF THE WEEK BEHIND THE
DEPARTING FRONT, WITH HIGHS DROPPING INTO THE UPPER 50S/LOWER 60S
FOR WEDNESDAY THROUGH FRIDAY. OVERNIGHT LOWS WILL DIP INTO THE 30S,
WITH THE BEST POTENTIAL FOR FROST LIKELY SETTING UP FOR WEDNESDAY
NIGHT AND THURSDAY NIGHT AS SKIES REMAIN CLEAR AND WINDS DIMINISH.
FURTHER OUT, MAJOR MODEL DISCREPANCIES HAVE DEVELOPED CONCERNING THE
NEXT POTENTIAL SYSTEM FOR THE END OF THE WEEK. THE 00Z APR 20 GFS
HAS MADE A MAJOR SHIFT FROM ITS PREVIOUS RUNS AND NOW SHOWS RAIN
SPREADING INTO CENTRAL ILLINOIS FROM AN APPROACHING UPPER LOW AS
EARLY AS FRIDAY. MEANWHILE, BOTH THE ECMWF AND GEM ARE MUCH SLOWER,
WITH RAIN NOT ARRIVING UNTIL LATE FRIDAY NIGHT INTO SATURDAY. GIVEN
INITIAL PRESENCE OF A STRONG RIDGE AXIS ACROSS THE MIDWEST, THINK
THE RAPID PROGRESSION OF RAIN INTO THE DRY AIRMASS SEEMS SUSPECT.
IN ADDITION, THE SLOWER ECMWF/GEM HAVE MAINTAINED GOOD CONSISTENCY
WITH THEIR EARLIER RUNS. AS A RESULT, HAVE REJECTED THE GFS IN
FAVOR OF THE ECMWF/GEM CONSENSUS FOR THE END OF THE WEEK. HAVE
THEREFORE KEPT FRIDAY DRY, THEN HAVE INTRODUCED POPS MAINLY ACROSS
THE CENTRAL AND SOUTHERN CWA FRIDAY NIGHT INTO SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 630 AM CDT MON APR 20 2015
CLOUDS OVER THE TAF SITES ARE AT MVFR LEVELS, EXCEPT FOR BMI THAT
IS AT IFR RIGHT NOW. BELIEVE THAT BMI WILL IMPROVE TO LOWER MVFR
SOON, BUT STILL HAVE A TEMPO GROUP FOR A COUPLE HOURS TO COVER.
MVFR CIGS WILL CONTINUE THIS MORNING. SATELLITE TRENDS SHOW
CLEARING TO THE WEST OF SPI, BUT BELIEVE ONCE SUN GETS LITTLE
HIGHER, CU/SC WILL DEVELOP QUICKLY, KEEPING CLOUDS OVER SPI LATE
THIS MORNING. HIRES MODELS CONTINUE TO SHOW SCATTERED SHOWERS
DEVELOPING TO THE WEST AND MOVING INTO THE AREA. AGREE WITH THIS
FORECAST SO HAVE INCLUDED VCSH AT ALL TAF SITES FOR THIS
AFTERNOON. CLOUDS AND PCPN WILL BE DIURNAL, SO SKIES SHOULD CLEAR
JUST AFTER SUNSET. BIGGEST ISSUE WILL BE THE GUSTY WEST WINDS.
WILL HAVE GUSTS TO 25-28KTS THIS MORNING, BUT THEN INCREASE TO
30KTS FOR THIS AFTERNOON. WINDS WILL DIMINISH THIS EVENING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
719 AM CDT MON APR 20 2015
.UPDATE...
ISSUED AT 718 AM CDT MON APR 20 2015
DOPPLER RADAR INDICATED THE WEST (BACK) EDGE OF THE DEFORMATION ZONE
PRODUCING LIGHT RAIN AND SPRINKLES EXTENDED FROM ABOUT MANCHESTER IA
TO THE QUAD CITIES AND WAS MOVING EAST AT ABOUT 20 MPH. THIS PUTS THE
BACK EDGE EXITING THE DVN CWA BY AROUND 10 AM OR SO. NORTHWEST
WINDS HAVE BEEN GUSTING TO 30 TO 40 MPH THE PAST SEVERAL HOURS AND
EARLIER I ISSUED A SPECIAL WEATHER STATEMENT FOR THE MORNING COMMUTE.
HOWEVER...WINDS WILL REMAIN STRONG FOR MUCH OF THE DAY AND THEN
DIMINISH QUICKLY TOWARDS SUNSET.
THE LATEST HRRR AND WRF MODELS HAVE COME IN A BIT MORE AGGRESSIVE
WITH THE SHOWERS ACROSS THE CWA. THEREFORE HAVE RAISED POPS TO 30
PERCENT AND DESCRIBED IT AS "ISOLATED TO SCATTERED SHOWERS".
&&
.SYNOPSIS...
ISSUED AT 335 AM CDT MON APR 20 2015
DEEPENING CYCLONE (987 MB) WAS LOCATED IN EXTREME WESTERN LOWER MI
AND BROUGHT WIDESPREAD RAIN TO THE DVN CWA LAST EVENING AND OVERNIGHT.
A COLD FRONT HAS SWEPT THROUGH THE AREA WITH NORTHWEST WINDS GUSTING
TO 35 MPH. DOPPLER RADAR INDICATED LIGHT RAIN STILL FALLING ROUGHLY
ALONG AND NORTH OF HIGHWAY 30 IN IA AND IL AND WAS GRADUALLY LIFTING
NORTHWARD. CURRENT TEMPERATURES RANGED FROM THE LOWER 40S TO MID 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT MON APR 20 2015
FORECAST FOCUS ON RAIN CHANCES...WIND AND TEMPERATURES.
TODAY...THIS WILL BE A VERY WINDY AND MUCH COOLER DAY AS THE DEEPENING
CYCLONE TRACKS NORTHWARD TO JUST NORTH OF LAKE SUPERIOR. THE STRATIFORM
RAIN SHIELD SHOULD LIFT OUT OF THE DVN CWA BY MID TO LATE MORNING.
OTHERWISE PARTLY SUNNY SKIES ARE EXPECTED WITH FORECAST SOUNDINGS
INDICATING DEEP MIXING TO ABOUT 700 MB BRINGING DOWN 35 TO 40 MPH
WIND GUSTS...WHICH IS BELOW ADVISORY CRITERIA. NONETHELESS HANG ONTO
YOUR HAT AND THE STEERING WHEEL! STEEP LAPSE RATES AND ENOUGH MOISTURE
SHOULD ALLOW FOR ISOLATED HIGH-BASED RAIN SHOWERS ANYWHERE IN THE CWA
LATER THIS MORNING THROUGH THE AFTERNOON. THE HRRR AND WRF MODELS DEPICT
THIS SCENARIO QUITE WELL. TEMPERATURES WILL BE A CHALLENGE AGAIN AS
WE HAVE COLD AIR ADVECTION BUT THERE WILL ALSO BE SOME SUNSHINE TO
OFFSET THIS SOMEWHAT. THEREFORE A GOOD COMPROMISE SEEMS TO BE HIGHS
IN THE UPPER 50S TO LOWER 60S.
TONIGHT...DEEP CYCLONE (980 MB) WILL BE ANCHORED NORTH OF LAKE SUPERIOR
DUE TO A STRONG GREENLAND BLOCK. SKIES SHOULD BE PARTLY CLOUDY AND GUSTY
WEST WINDS WILL DIMINISH BY SUNSET WITH DECOUPLING. HOWEVER... THE WINDS
SHOULD STAY AT 10 TO 15 MPH MUCH OF THE NIGHT. MINIMUM TEMPERATURES
IN THE 35 TO 40 RANGE SHOULD BE COMMON. A FEW SHOWERS MAY LINGER INTO
THE EARLY EVENING HOURS FOR LATER SHIFTS TO CONSIDER...BUT FOR NOW I
WILL CONTINUE A DRY FORECAST FOR TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 AM CDT MON APR 20 2015
SEASONABLY COOL AND MAINLY DRY FOR MUCH OF THE WEEK WITH FROST/FREEZE
POTENTIAL LATER IN THE WEEK.
NORTHWEST FLOW PATTERN WILL GOVERN MUCH OF THE LONG TERM PERIOD AS
BLOCKING DEVELOPS OVER EASTERN ATLANTIC AND GREENLAND RESULTING IN
SLOW EASTWARD PROGRESSION OF GREAT LAKES UPPER LOW. SERIES OF
IMPULSES WILL ROTATE AROUND THE CYCLONE WITH NORTHERN CWA IN CLOSER
PROXIMITY AND THUS FAVORED FOR MORE DIURNAL DRIVEN CLOUD COVER ON
TUESDAY ALONG WITH SPRINKLES AND SOME LIGHT POPCORN SHOWERS GIVEN
STEEP LAPSE RATES...COLD AIR ALOFT AND PRESENCE OF SKINNY CAPE NOTED
ON FORECAST SOUNDINGS. MAIN ITEM ON TUESDAY WILL BE WINDY CONDITIONS
WITH POTENTIAL FOR WIND ADVISORY AS NAM/GFS BUFR SOUNDINGS SHOWING
30-35 KTS OF WIND ON AVERAGE THROUGH THE MIXED LAYER WITH 50-55 KTS
SITTING ATOP DEEP MIXED LAYER TO NEAR 650 MB. POSSIBLE AS WELL THAT
ANY SHOWERS COULD ENHANCE WIND GUSTS VIA EVAPORATIVE COOLING OF
PCPN IN LARGE... DRY SUB-CLOUD LAYER WITH CLASSIC INVERTED V TYPE
SOUNDINGS.
CANADIAN SURFACE RIDGE AXIS WILL BUILD IN OVER THE LATTER HALF OF THE
WEEK AS THE UPPER LOW PLODS EASTWARD FROM GREAT LAKES. THIS WILL
BRING DIMINISHING WINDS WEDNESDAY THROUGH FRIDAY BUT ALSO REINFORCE
COOL... DRY AIR WITH MORE IDEAL RADIATIONAL COOLING SETUP LEADING TO
INCREASING RISK FOR AREAS OF FROST AND FREEZING TEMPS POSSIBLY AS
EARLY AS WEDNESDAY AM... BUT MORE LIKELY THURSDAY/FRIDAY AM. FREEZE
HIGHLIGHTS ARE ACTIVE IF NEEDED WITH FRUIT TREES NOW SUSCEPTIBLE
TO TEMPS AT/BELOW 28F PER FEEDBACK FROM ISU EXTENSION COMMERCIAL
HORTICULTURE SPECIALIST. NURSERIES AND STORES ALSO MOVING
STOCK OUTDOORS... AND RECENT WARM SPELL AND MOISTURE HAS CAUSED YARDS
TO ADVANCE QUICKLY.
TOWARD SATURDAY AND INTO THE FIRST HALF OF THE WEEKEND THERE IS THE
POTENTIAL FOR RAIN CHANCES WITH ANOTHER STORM SYSTEM. CONFIDENCE IS
LOW AS MODEL VARIANCE QUITE HIGH. DPROG/DT... OR COMPARISON OF MODELS
RUN TO RUN... SHOWS BETTER CONSISTENCY EXISTS WITH ECMWF WHICH IS
SLOWER AND FAVORS SOUTHERN CWA FOR BETTER RAIN CHANCES DUE TO MORE
SOUTHERLY TRACK OF SYSTEM AND INCREASING EASTERLY FLOW. GFS ENSEMBLE
MEANS SIMILAR LINES OF ECMWF AND ACTUALLY SUGGEST MUCH IF NOT ALL OF
RAIN STAYING TO OUR SOUTH FROM PARTS OF MID TO LOWER MISSISSIPPI VLY
WHICH ALSO FITS WITH PATTERN OF LATE. AS RESULT... HAVE ADJUSTED POPS
TO LOWER OR REMOVE ACROSS THE NORTH/EAST FRIDAY NIGHT AND SATURDAY AND
PLACE THE BEST CHANCES ACROSS THE SOUTHERN CWA.
TEMPS THROUGHOUT THE ENTIRE PERIOD LOOK TO REMAIN SEASONABLY COOL WITH
HIGHS 50S/60S... AND LOWS MAINLY IN THE 30S WITH SOME 20S IN FAVORED
DRAINAGE LOCATIONS WEDNESDAY THROUGH FRIDAY MORNINGS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 648 AM CDT MON APR 20 2015
MVFR CIGS THIS MORNING THEN VFR CIGS THIS AFTERNOON AND VFR NO CIGS
TONIGHT. ISOLATED TO SCATTERED SHOWERS LATE THIS MORNING THROUGH THE
AFTERNOON. NORTHWEST WINDS SUSTAINED 15 TO 20 KNOTS WITH GUSTS TO
30 KNOTS TODAY THEN WEST 10 TO 15 KNOTS TONIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...HAASE
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...MCCLURE
AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
651 AM CDT MON APR 20 2015
.SYNOPSIS...
ISSUED AT 335 AM CDT MON APR 20 2015
DEEPENING CYCLONE (987 MB) WAS LOCATED IN EXTREME WESTERN LOWER MI
AND BROUGHT WIDESPREAD RAIN TO THE DVN CWA LAST EVENING AND OVERNIGHT.
A COLD FRONT HAS SWEPT THROUGH THE AREA WITH NORTHWEST WINDS GUSTING
TO 35 MPH. DOPPLER RADAR INDICATED LIGHT RAIN STILL FALLING ROUGHLY
ALONG AND NORTH OF HIGHWAY 30 IN IA AND IL AND WAS GRADUALLY LIFTING
NORTHWARD. CURRENT TEMPERATURES RANGED FROM THE LOWER 40S TO MID 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT MON APR 20 2015
FORECAST FOCUS ON RAIN CHANCES...WIND AND TEMPERATURES.
TODAY...THIS WILL BE A VERY WINDY AND MUCH COOLER DAY AS THE DEEPENING
CYCLONE TRACKS NORTHWARD TO JUST NORTH OF LAKE SUPERIOR. THE STRATIFORM
RAIN SHIELD SHOULD LIFT OUT OF THE DVN CWA BY MID TO LATE MORNING.
OTHERWISE PARTLY SUNNY SKIES ARE EXPECTED WITH FORECAST SOUNDINGS
INDICATING DEEP MIXING TO ABOUT 700 MB BRINGING DOWN 35 TO 40 MPH
WIND GUSTS...WHICH IS BELOW ADVISORY CRITERIA. NONETHELESS HANG ONTO
YOUR HAT AND THE STEERING WHEEL! STEEP LAPSE RATES AND ENOUGH MOISTURE
SHOULD ALLOW FOR ISOLATED HIGH-BASED RAIN SHOWERS ANYWHERE IN THE CWA
LATER THIS MORNING THROUGH THE AFTERNOON. THE HRRR AND WRF MODELS DEPICT
THIS SCENARIO QUITE WELL. TEMPERATURES WILL BE A CHALLENGE AGAIN AS
WE HAVE COLD AIR ADVECTION BUT THERE WILL ALSO BE SOME SUNSHINE TO
OFFSET THIS SOMEWHAT. THEREFORE A GOOD COMPROMISE SEEMS TO BE HIGHS
IN THE UPPER 50S TO LOWER 60S.
TONIGHT...DEEP CYCLONE (980 MB) WILL BE ANCHORED NORTH OF LAKE SUPERIOR
DUE TO A STRONG GREENLAND BLOCK. SKIES SHOULD BE PARTLY CLOUDY AND GUSTY
WEST WINDS WILL DIMINISH BY SUNSET WITH DECOUPLING. HOWEVER... THE WINDS
SHOULD STAY AT 10 TO 15 MPH MUCH OF THE NIGHT. MINIMUM TEMPERATURES
IN THE 35 TO 40 RANGE SHOULD BE COMMON. A FEW SHOWERS MAY LINGER INTO
THE EARLY EVENING HOURS FOR LATER SHIFTS TO CONSIDER...BUT FOR NOW I
WILL CONTINUE A DRY FORECAST FOR TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 AM CDT MON APR 20 2015
SEASONABLY COOL AND MAINLY DRY FOR MUCH OF THE WEEK WITH FROST/FREEZE
POTENTIAL LATER IN THE WEEK.
NORTHWEST FLOW PATTERN WILL GOVERN MUCH OF THE LONG TERM PERIOD AS
BLOCKING DEVELOPS OVER EASTERN ATLANTIC AND GREENLAND RESULTING IN
SLOW EASTWARD PROGRESSION OF GREAT LAKES UPPER LOW. SERIES OF
IMPULSES WILL ROTATE AROUND THE CYCLONE WITH NORTHERN CWA IN CLOSER
PROXIMITY AND THUS FAVORED FOR MORE DIURNAL DRIVEN CLOUD COVER ON
TUESDAY ALONG WITH SPRINKLES AND SOME LIGHT POPCORN SHOWERS GIVEN
STEEP LAPSE RATES...COLD AIR ALOFT AND PRESENCE OF SKINNY CAPE NOTED
ON FORECAST SOUNDINGS. MAIN ITEM ON TUESDAY WILL BE WINDY CONDITIONS
WITH POTENTIAL FOR WIND ADVISORY AS NAM/GFS BUFR SOUNDINGS SHOWING
30-35 KTS OF WIND ON AVERAGE THROUGH THE MIXED LAYER WITH 50-55 KTS
SITTING ATOP DEEP MIXED LAYER TO NEAR 650 MB. POSSIBLE AS WELL THAT
ANY SHOWERS COULD ENHANCE WIND GUSTS VIA EVAPORATIVE COOLING OF
PCPN IN LARGE... DRY SUB-CLOUD LAYER WITH CLASSIC INVERTED V TYPE
SOUNDINGS.
CANADIAN SURFACE RIDGE AXIS WILL BUILD IN OVER THE LATTER HALF OF THE
WEEK AS THE UPPER LOW PLODS EASTWARD FROM GREAT LAKES. THIS WILL
BRING DIMINISHING WINDS WEDNESDAY THROUGH FRIDAY BUT ALSO REINFORCE
COOL... DRY AIR WITH MORE IDEAL RADIATIONAL COOLING SETUP LEADING TO
INCREASING RISK FOR AREAS OF FROST AND FREEZING TEMPS POSSIBLY AS
EARLY AS WEDNESDAY AM... BUT MORE LIKELY THURSDAY/FRIDAY AM. FREEZE
HIGHLIGHTS ARE ACTIVE IF NEEDED WITH FRUIT TREES NOW SUSCEPTIBLE
TO TEMPS AT/BELOW 28F PER FEEDBACK FROM ISU EXTENSION COMMERCIAL
HORTICULTURE SPECIALIST. NURSERIES AND STORES ALSO MOVING
STOCK OUTDOORS... AND RECENT WARM SPELL AND MOISTURE HAS CAUSED YARDS
TO ADVANCE QUICKLY.
TOWARD SATURDAY AND INTO THE FIRST HALF OF THE WEEKEND THERE IS THE
POTENTIAL FOR RAIN CHANCES WITH ANOTHER STORM SYSTEM. CONFIDENCE IS
LOW AS MODEL VARIANCE QUITE HIGH. DPROG/DT... OR COMPARISON OF MODELS
RUN TO RUN... SHOWS BETTER CONSISTENCY EXISTS WITH ECMWF WHICH IS
SLOWER AND FAVORS SOUTHERN CWA FOR BETTER RAIN CHANCES DUE TO MORE
SOUTHERLY TRACK OF SYSTEM AND INCREASING EASTERLY FLOW. GFS ENSEMBLE
MEANS SIMILAR LINES OF ECMWF AND ACTUALLY SUGGEST MUCH IF NOT ALL OF
RAIN STAYING TO OUR SOUTH FROM PARTS OF MID TO LOWER MISSISSIPPI VLY
WHICH ALSO FITS WITH PATTERN OF LATE. AS RESULT... HAVE ADJUSTED POPS
TO LOWER OR REMOVE ACROSS THE NORTH/EAST FRIDAY NIGHT AND SATURDAY AND
PLACE THE BEST CHANCES ACROSS THE SOUTHERN CWA.
TEMPS THROUGHOUT THE ENTIRE PERIOD LOOK TO REMAIN SEASONABLY COOL WITH
HIGHS 50S/60S... AND LOWS MAINLY IN THE 30S WITH SOME 20S IN FAVORED
DRAINAGE LOCATIONS WEDNESDAY THROUGH FRIDAY MORNINGS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 648 AM CDT MON APR 20 2015
MVFR CIGS THIS MORNING THEN VFR CIGS THIS AFTERNOON AND VFR NO CIGS
TONIGHT. ISOLATED TO SCATTERED SHOWERS LATE THIS MORNING THROUGH THE
AFTERNOON. NORTHWEST WINDS SUSTAINED 15 TO 20 KNOTS WITH GUSTS TO
30 KNOTS TODAY THEN WEST 10 TO 15 KNOTS TONIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...MCCLURE
AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
954 AM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH MONDAY AND MOVE OFFSHORE LATE MONDAY
NIGHT. HIGH PRESSURE BUILDS OVER THE REGION TUESDAY AND WEDNESDAY.
A WEAK COLD FRONT WILL CROSS THE AREA THURSDAY. ANOTHER
DISTURBANCE WILL AFFECT THE REGION NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 950 AM MONDAY...GOOD SUBSIDENCE ACROSS THE REGION THIS
MORNING IN THE WAKE OF LAST NIGHT`S CONVECTION AND PRECIPITATION.
LOTS OF LEFT OVER LOW CLOUDS...BUT THEY SHOULD SCOUT OUT AS
SOUTHWEST FLOW INCREASES. SOME STRONG/SEVERE CONVECTION AROUND THE
CHARLOTTE AREA CURRENTLY AND WILL WATCH THE EVOLUTION OF THIS
ACTIVITY INTO THE AFTERNOON. LATEST 3KM HRRR SHOWS THIS CONVECTION
MOVING NORTHEAST AND DISSIPATING WITH ADDITIONAL STORMS DEVELOPING
IN OUR CWA IN THE 20Z-22Z TIME FRAME. LOOKS WARM THIS AFTERNOON
AHEAD OF THE FRONT WITH HIGHS INTO THE 80S AWAY FROM THE COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 430 AM MONDAY...THE FRONT WILL CROSS THE AREA EARLY
TUESDAY. THE CHALLENGE WILL BE THE EXTENT OF PRECIPITATION AHEAD
OF THE FRONT AND IF STORMS WILL DEVELOP/MOVE INTO THE AREA. GIVEN
THE TIMING OF THE FRONT...FEEL THE CHANCE OF THUNDERSTORMS WILL BE
LIMITED AS PEAK HEATING WILL HAVE ALREADY OCCURRED.
FURTHERMORE...THE BEST SYNOPTIC FORCING...SFC FRONT AND PEAK
HEATING WILL NOT COEXIST GIVING THIS SCENARIO A LOW CONFIDENCE
LEVEL IN TERMS OF THUNDERSTORM DEVELOPMENT AND SUBSTAINABILITY.
GIVEN MARGINAL LIFT...INSTABILITY AND SHEAR...WE CAN NOT RULE OUT
DISCRETE THUNDERSTORMS POSSIBLY BECOMING LINEAR IN NATURE DURING
THE EVENING HOURS...BUT THE OVERALL SPATIAL EXTENT LOOKS MINIMAL.
BY THE TIME THE MID-LEVEL DRY AIR BECOMES BETTER
SATURATED...INSTABILITY WILL HAVE DIMINISH QUITE A BIT. IF THE
FRONT MOVES A BIT FASTER THAN ANTICIPATED OR THERE IS BETTER
LIFT/SATURATION AHEAD OF THE FRONT...THEN THERE MAY BE BETTER
SPATIAL COVERAGE OF THUNDERSTORMS. AT THIS TIME...WE FEEL ANY
ACTIVITY WILL WANE AS IT CROSSES EASTERN NC DURING THE EVENING
HOURS. KEPT A CHANCE POP IN FOR THE TIME BEING. PRECIPITATION
CHANCES SHOULD DIMINISH AFTER 10Z WITH THE FRONT MOVING THROUGH BY
12Z. LOWS IN THE LOW 60S INLAND TO MID 60S ALONG THE BEACHES.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 545 AM MON...ONLY MINOR CHANGES FOR THE LONG TERM FORECAST
WITH MODELS IN MODEST AGREEMENT THROUGH THE MEDIUM RANGE. FOR
TUESDAY/WEDNESDAY...SEASONABLY MILD CONDITIONS WITH WARM DAYS AND
COOL NIGHTS EXPECTED AS ZONAL FLOW BRINGS NEAR CLIMO TEMPS AND DRY
WEATHER TO THE REGION. HIGHS SHOULD GENERALLY BE IN THE 70S WITH
LOWS IN THE UPR 40S TO MID 50S.
WEDNESDAY NIGHT/THURSDAY...SOME MINOR DIFFERENCES IN MOISTURE
AVAILABILITY WITH COLD FRONT THAT WILL SAG INTO THE AREA ON
THURSDAY. HAVE CONTINUED TO SIDE WITH DRIER SOLN WITH GFS
APPEARING TO HAVE A WET BIAS. DETERMINISTIC ECMWF MORE IN LINE
WITH ITS ENSEMBLE MEAN IN KEEPING THE AREA DRY...THEREFORE HAVE NO
HIGHER THAN A 20 POP LATE WED NIGHT INTO THUR. ANOTHER SEASONABLE
DAY ON THUR WITH HIGHS IN THE 70S AS WINDS SHIFT NORTHWESTERLY
BEHIND THE FRONT.
THURSDAY NIGHT/FRIDAY...DRY WEATHER BEHIND THE FRONT WITH SUNNY DRY
AND COOLER WEATHER. SLIGHTLY BELOW CLIMO EXPECTED WITH LOWS IN THE
40S TO NEAR 50 AND HIGHS IN THE MID 60S TO NEAR 70.
FRIDAY NIGHT/SATURDAY...A PRONOUNCED SOUTHERN STREAM SYSTEM MAY
AFFECT THE AREA THIS WEEKEND. SIGNIFICANT TIMING DIFFERENCES EXIST
THIS FAR OUT HOWEVER AND MAINTAINED THE SMALL CHANCE POPS IN THE
FCST. TEMPS WILL LIKELY REMAIN BELOW CLIMO DUE TO THE INCREASED
CLOUDS AND PRECIP WITH THE AREA ON THE COOL SIDE OF THE FRONTAL
BOUNDARY.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 12Z TUESDAY/...
AS OF 700 AM MONDAY...THE BULK OF THE PRECIPITATION HAS MOVED
OFFSHORE AT THIS TIME. LOW LEVEL CLOUDS WILL SLOWLY ERODE GIVING
WAY TO SCATTERED CU BY AFTERNOON. GUSTY SOUTHWEST WINDS CAN BE
EXPECTED AS A FRONT APPROACHES FROM THE WEST. GUSTS EXPECTED AOB
25KTS DURING THE AFTERNOON/EARLY EVENING HOURS. CLOUDS MAY START
TO BUILD IN WEST TO EAST JUST AHEAD OF THE FRONT. SHOWERS/STORMS
ASSOCIATED WITH THIS FRONT LOOKS LIMITED. SO KEPT THE MENTION OUT
OF THE TAFS FOR NOW. WINDS WILL VEER TO THE NW BEHIND THE FRONT BY
TUESDAY MORNING. FOG/STRATUS DOES NOT LOOK PROBABLY OVERNIGHT
MONDAY GIVEN THE MIX BL AND SUFFICIENT DRY AIR.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 550 AM MON...HIGH PRESSURE BUILDS ACROSS EASTERN NC TUESDAY
INTO WEDNESDAY YIELDING MOSTLY VFR CONDITIONS. A WEAK FRONT WILL
MOVE SOUTH INTO EASTERN NC THURSDAY BUT WITH LIMITED MOISTURE SO
EXPECT MOSTLY VFR CONDITIONS THURSDAY. A BETTER CHANCE FOR PRECIP
ARRIVES NEXT WEEKEND.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 950 AM MONDAY...SCA HAS EXPIRED OVER PAMLICO SOUND AS WINDS
HAVE DROPPED OFF TO 10 TO 15 KNOTS. EXPECT S/SW WINDS TO INCREASE
TO 15 TO 20 KNOTS BY MIDDAY. SEAS ARE IN THE 5 TO 8 FOOT RANGE.
CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE AND NO CHANGES NEEDED.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 550 AM MON...SEAS WILL REMAIN ELEVATED INTO TUESDAY MORNING
AND CURRENT SCA FOR ALL COASTAL WATERS WILL REMAIN IN EFFECT UNTIL
12Z TUESDAY. HIGH PRESSURE WILL BUILD OVER THE NC WATERS TUESDAY
INTO WEDNESDAY WITH WINDS SHIFTING MORE WESTERLY, 5-15 KT. SEAS
WILL DIMINISH TO 2-4 FT TUESDAY NIGHT THROUGH WEDNESDAY. A COLD
FRONT WILL MOVE SOUTH INTO THE NORTHERN WATERS THURSDAY AND SHIFT
SOUTH OF THE WATERS BY THURSDAY NIGHT. WINDS VEER NORTHWEST BEHIND
THE FRONT BUT REMAIN 5-15 KT WITH PLEASANT BOATING CONDITIONS
EXPECTED AND SEAS AROUND 2 TO 3 FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR AMZ150-152-154-
156-158.
&&
$$
SYNOPSIS...CTC/LEP
NEAR TERM...CTC
SHORT TERM...LEP
LONG TERM...DAG
AVIATION...DAG/TL/LEP
MARINE...CTC/DAG
AREA FORECAST DISCUSSION
NWS RALEIGH NC
756 AM EDT MON APR 20 2015
.SYNOPSIS...A COLD FRONT WILL APPROACH THE MOUNTAINS FROM THE WEST
THIS AFTERNOON...THEN TRACK EAST ACROSS THE CAROLINAS THIS EVENING.
HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE SOUTHWEST TONIGHT
AND TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 745 AM MONDAY...
UPDATE: THE TN VALLEY MCS HAS PERSISTED LONGER THAN PREVIOUSLY
ANTICIPATED. ALTHOUGH THE ENVIRONMENT DOWNSTREAM OF THIS FEATURE IS
MARGINALLY UNSTABLE BY VIRTUE OF RELATIVELY STEEP MID-LEVEL LAPSE
RATES ATOP A SEASONABLY MOIST WARM-SECTOR AIRMASS...ADDITIONAL (I.E.
SUPPLEMENTAL) FORCING FOR ASCENT IS LARGELY ABSENT. AS A RESULT...
ADDITIONAL WEAKENING OF THE MCS SHOULD ACCELERATE THE WEAKENING
PROCESS AND RESULT IN RAPID DECAY...SIMILAR TO 10Z HRRR SIM REF
FORECASTS. REGARDLESS...HAVE UPDATED THE FORECAST TO INTRODUCE A
SLIGHT CHANCE OF SHOWERS THIS MORNING TO ACCOUNT FOR THE POSSIBILITY
OF A SLOWER WEAKENING TREND. -VINCENT
OVERVIEW: A LOW-LEVEL TROUGH /WEAK WARM FRONT/...ASSOCIATED WITH A
DEEPENING SFC CYCLONE ATTENDANT A POTENT UPPER TROUGH DIGGING SE
INTO THE UPPER GREAT LAKES...WILL LIFT NORTHWARD THROUGH THE
DELMARVA THIS MORNING AND NORTHEAST ALONG THE MID-ATLANTIC COAST
THIS AFT/EVE INTO TONIGHT. MEANWHILE...A COLD FRONT (ATTENDANT THE
AFOREMENTIONED CYCLONE) TRACKING EASTWARD THROUGH THE TN VALLEY THIS
MORNING WILL PROGRESS ACROSS THE SOUTHERN APPALACHIANS LATE THIS
AFTERNOON...THEN TRACK EAST ACROSS THE CAROLINAS THIS EVENING INTO
TONIGHT.
PRECIPITATION: THE RECENT INCREASE IN CONVECTIVE INTENSITY OVER THE
COASTAL PLAIN IS ASSOCIATED WITH ENHANCED LOW-LEVEL CONVERGENCE
/BACKED LOW-LEVEL FLOW/ AND THE ADVECTION OF A HIGHER THETA-E
AIRMASS INTO EASTERN NC...APPARENTLY IN RESPONSE TO DPVA ATTENDANT
THE NEGATIVELY TILTED SHORTWAVE CURRENTLY TRACKING NE ACROSS THE
REGION. NOW THAT THIS ACTIVITY HAS EXITED CENTRAL NC...EXPECT DRY
CONDITIONS TO PREVAIL THROUGH SUNRISE IN ASSOC/W SUBSIDENCE IN THE
WAKE OF THE AFOREMENTIONED SHORTWAVE AND...FOR THE REMAINDER OF THE
MORNING...A LACK OF FORCING DRYING ALOFT COMBINED WITH DRYING ALOFT
ASSOC/W THE ADVECTION OF A MODIFIED ELEVATED MIXED LAYER INTO THE
REGION FROM THE SOUTHWEST. UNCERTAINTY INCREASES BY EARLY AFTERNOON
REGARD TO WHETHER OR NOT THE ONGOING TN VALLEY MCS WILL CROSS THE
SOUTHERN APPALACHIANS AND RESULT IN A POTENTIAL FOR CONVECTION IN
THE FAR WESTERN PIEDMONT BETWEEN 15-18Z. THE LATEST HIGH-RES CAMS
SUGGEST THAT THE MCS WILL DECAY ON APPROACH TO THE MOUNTAINS ~12Z AS
THE THERMODYNAMIC ENVIRONMENT BECOMES LESS FAVORABLE (I.E.
INCREASING CINH). EVEN IF THE MCS DECAYS PRIOR TO CROSSING THE
MOUNTAINS...THE PRESENCE OF AN MCV AND/OR LINGERING CONVECTIVE
DEBRIS/OUTFLOW WOULD INTRODUCE CONSIDERABLE UNCERTAINTY TO THE
CONVECTIVE FORECAST THIS AFTERNOON. EVEN IF ONE ASSUMES THE
AFOREMENTIONED FEATURES ARE ABSENT...THE CONVECTIVE FORECAST REMAINS
UNCERTAIN GIVEN A TEMPORAL/SPATIAL DISCONNECT BETWEEN THE BEST
SYNOPTIC FORCING (DPVA IN SW FLOW ALOFT BETWEEN 00-06Z)...THE BEST
LOW-LEVEL FOCUS (PRE-FRONTAL TROUGH IN THE WESTERN PIEDMONT BY
~00Z)...AND PEAK HEATING. WITH THE ABOVE IN MIND...WILL MAKE LITTLE
CHANGE TO THE PRIOR FORECAST AND INDICATE PRECIP CHANCES OF 40-50%
DURING THE LATE AFTERNOON AND EVENING...ENDING FROM WEST-EAST BY OR
SHORTLY AFTER MIDNIGHT.
SEVERE THREAT: MODERATE DESTABILIZATION (MLCAPE 1000-2000 J/KG) IS
EXPECTED TODAY IN ASSOC/W CLEARING SKIES...A MODIFIED ELEVATED MIXED
LAYER (CHARACTERIZED BY H7-H5 LAPSE RATES ON THE ORDER OF 6.5-7
C/KM)...AND SEASONABLY RICH LOW-LEVEL MOISTURE (DWPTS UPPER
50S/LOWER 60S) WITHIN AN INCREASINGLY WELL-MIXED WARM SECTOR
DOWNSTREAM OF THE APPROACHING COLD FRONT...WITH LITTLE IN THE WAY OF
A CAP /CINH/ PER LATEST FORECAST SOUNDINGS. ANY UPDRAFTS THAT
DEVELOP PRIOR TO ~21Z THIS AFTERNOON ARE UNLIKELY TO SURVIVE
ENTRAINMENT GIVEN A DRY AIRMASS ALOFT AND A GENERAL LACK OF FORCING
THROUGHOUT THE COLUMN...ASSUMING NO CONTRIBUTION FROM UPSTREAM
CONVECTION. BY LATE AFTERNOON...MODERATE/UNTAPPED INSTABILITY AND AN
ABSENCE OF CONVECTIVE INHIBITION ARE EXPECTED TO ALLOW CONVECTIVE
DEVELOPMENT ALONG THE COLD FRONT /PRE-FRONTAL TROUGH/ PROGRESSING
INTO THE FOOTHILLS...WITH UNIDIRECTIONAL DEEP-LAYER SHEAR SUFFICIENT
FOR SPLITTING SUPERCELLS AND UPSCALE GROWTH INTO A LINEAR MCS
THEREAFTER...THOUGH THE LATEST CONVECTION ALLOWING MODELS SUGGEST
MULTIPLE LINE SEGMENTS MAY DEVELOP RATHER THAN A SOLID LINE...WHICH
SEEMS REASONABLE GIVEN THE UNCERTAINTIES MENTIONED ABOVE. SHOULD
SPLITTING SUPERCELLS DEVELOP IN THE WESTERN PIEDMONT...LARGE HAIL
(UP TO GOLFBALL SIZE) AND DAMAGING WINDS WOULD BE POSSIBLE GIVEN
SPEEDY MID-LEVEL FLOW...MDT INSTABILITY AND STEEP MID-LEVEL LAPSE
RATES. FURTHER EAST...DAMAGING WINDS WOULD BE THE PRIMARY THREAT...
WITH SEVERE HAIL CONFINED TO ROTATING UPDRAFTS EMBEDDED WITHIN LINE
SEGMENTS. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 345 AM MONDAY...
DRY CONDITIONS WILL PREVAIL IN THE WAKE OF THE COLD FRONT TUE/TUE
NIGHT...WITH HIGHS IN THE UPPER 60S TO LOWER 70S AND LOWS MID/UPPER
40S TO PERHAPS 50F FAR SE COASTAL PLAIN WED MORNING. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 120 AM MONDAY...
DRY WEATHER EXPECTED WEDNESDAY AND THURSDAY.
HIGH CONFIDENCE FORECAST FOR MID WEEK AS HIGH PRESSURE WILL DOMINATE
AND BRING DRY WEATHER WITH SEASONABLY COOL TEMPERATURES WEDNESDAY
AND THURSDAY.
CONFIDENCE RAPIDLY DECREASES IN THE FORECAST BY FRIDAY THROUGH THE
WEEKEND AS MODELS SHOW SPREAD WITH HANDLING THE PROGRESSIVELY MOVING
SOUTHERN STREAM SYSTEM THAT MAY AFFECT OUR REGION AS EARLY AS
FRIDAY. JUST HOW THIS SYSTEM INTERACTS WITH THE POLAR JET AND THE
ASSOCIATED LOW LEVEL BOUNDARY WILL DETERMINE HOW QUICKLY THIS SYSTEM
MOVES AND HOW FAR NORTH THE SIGNIFICANT RAINFALL REACHES INTO THE MID-
ATLANTIC STATES. FOR NOW... WE WILL CARRY A CHANCE OF SHOWERS FOR
THE WEEKEND (CENTERED ON SATURDAY INTO SATURDAY NIGHT).
&&
.AVIATION /12Z MONDAY THROUGH THURSDAY/...
AS OF 700 AM MONDAY...
CONDITIONS WILL BECOME VFR BY MID/LATE MORNING. VSBYS SHOULD BECOME
VFR IN ALL AREAS THROUGH 09Z WITH THE LINE OF SHOWERS AND ISOLATED
STORMS FINALLY MOVING EAST OF KRWI SHORTLY. A SOUTH FLOW AT 10 MPH
WILL CONTINUE THROUGH DAYBREAK... THE GRADUALLY VEER TO THE SW AT 15-
20 MPH LATE MORNING AND AFTERNOON WITH GUSTS TO 30 MPH.
LOOKING FURTHER AHEAD...ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO FORM ALONG A COLD FRONT MONDAY
AFTERNOON OVER THE WESTERN SECTIONS OF THE AREA. THE CHANCE WILL
PUSH EAST WITH THE FRONT DURING THE LATE AFTERNOON AND EVENING.
OTHERWISE... VFR CONDITIONS WILL PREVAIL TONIGHT THROUGH THE END OF
THE WEEK DOMINATED BY HIGH PRESSURE BEGINNING TONIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...BADGETT
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1023 AM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY BRINGING ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS. DRY HIGH PRESSURE BUILDS IN FOR TUESDAY
AND WEDNESDAY. ANOTHER COLD FRONT WILL PUSH IN FROM THE NORTHWEST ON
THURSDAY...POSSIBLY BRINGING SHOWERS BACK TO THE AREA. A STRONGER
STORM SYSTEM WILL MOVE IN FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM...GUSTY TSTMS...WHAT APPEAR TO BE DRIVEN BY MCV...
SHOULD TRANSLATE QUICKLY EAST OF THE CWFA BY 15 UTC. IT SEEMS
LIKE THERE WILL BE SVRL HOURS OF ECHO FREE CONDITIONS ACRS THE
CWFA. WITHIN THE BROAD PRE-COLD FRONTAL ENVIRONMENT...PROGRESSIVE
DESTABILIZATION IS EXPECTED THROUGH THE AFTERNOON. THE NEWLY POSTED
12 UTC NAM AND CONVECTION ALLOWING MODELS EXPECTEDLY RESPOND
FAVORABLY WITHIN LLVL FRONTAL CONVERGENCE ZONE...PROGGING WIDESPREAD
DEEP CONVECTION. FAVORABLE SHEAR PROFILES LEND SUPPORT TO THE
PROBABILITY OF DISCRETE STORMS IN THE PIEDMONT LATER TODAY.
AS OF 645 AM...WELL THE NEAR TERM MODELS AND CAMS ARE NOT DOING VERY
WELL WITH THE CONVECTION ENTERING OUR WESTERN ZONES EARLY THIS
MORNING. HAVE BUMPED UP POP IN THE WEST. STILL EXPECT WEAKENING AS
THE REMNANT PRECIP CROSSES THE AREA THRU THE MORNING HOURS. CANNOT
RULE OUT A STRONG OR MARGINALLY SEVERE STORM EARLY ON...BUT
OTHERWISE JUST SOME CG LIGHTNING AND DOWNPOURS WITH THAT ACTIVITY.
THE REST OF THE FCST WAS LEFT UNCHANGED.
AS OF 330 AM...IN THE IMMEDIATE NEAR TERM...THE RADAR HAS GONE INTO
CLEAR AIR MODE...AS A LEAD SHORTWAVE HAS EXITED TO THE NE WITHIN
DEEP LAYER SWLY FLOW. A QUASI-LINEAR MCS IS CURRENTLY CROSSING
CENTRAL TN AND NRN AL. GUIDANCE SEEMS TO BE UNDERESTIMATING THE
STRENGTH/PERSISTENCE OF THIS SYSTEM. THE LATEST RAP ANALYSIS SHOWS
500-1000 J/KG OF MUCAPE WITH 35-45 KTS OF EFFECTIVE SHEAR DOWNSTREAM
OF THIS CLUSTER. THIS RESULTS IN A /MCS MAINTENANCE/ PROB AT 70-80
PCT. SO IT IS NOW EXPECTED THAT THESE STORMS (WHILE STILL ON A
GRADUAL WEAKENING TREND) WILL LIKELY STILL SURVIVE INTO THE NC MTNS
EARLY THIS MORNING. GIVEN THE CURRENT STATE...CANNOT RULE OUT A
STRONG OR SEVERE STORM OR TWO...ESP IN GRAHAM/SWAIN...WHEN THE LINE
GETS INTO THE CWFA. FROM THERE...IT/S DIFFICULT TO SAY HOW MUCH
PRECIP WILL LINGER ACRS THE CWFA THIS MORNING. I HAVE BUMPED UP POP
IN THE WRN MTNS...BUT KEEP JUST A SHOTGUN CHC POP FOR THE REST OF
THE AREA THIS MORNING.
LATER TODAY...GUIDANCE IN GOOD AGREEMENT ON ANOTHER SPOKE OF
VORTICITY ROTATING AROUND THE BROAD CYCLONICALLY CURVED
FLOW...CROSSING THE CWFA FROM THE SOUTHWEST DURING THE PEAK-HEATING
AFTN HOURS. MEANWHILE...A COLD FRONT WILL PUSH INTO THE AREA THIS
AFTN. THE FRONT LOOKS TO ONLY HAVE MODEST LLVL CONVERGENCE.
HOWEVER...GIVEN THE STEEP MID LVL LAPSE RATES AND LINGERING BL
MOISTURE (DEWPTS IN THE MID 60S ACRS THE PIEDMONT). FAIRLY CONFIDENT
IN AT LEAST 40-50 PCT COVERAGE OF CONVECTION...MAYBE HIGHER TO THE
EAST. THE FCST SNDGS SHOW LONG BUT SLIGHTLY CURVED HODOGRAPHS WITH
1500-2500 J/KG OF UNCAPPED SBCAPE. SO EXPECT SOMEWHAT DISCRETE
STORMS INITIALLY...WITH POTENTIAL FOR SUPERCELLS. DEFINITELY WILL
BE A DAMAGING WIND AND HAIL THREAT...WITH AN ISOLD TORNADO THREAT
ACRS THE PIEDMONT THIS AFTN. THE HIGH RES MODELS DO NOT SEEM THAT
IMPRESSED WITH COVERAGE OR INTENSITY. I/M NOT SURE WHAT IS LIMITING
THEIR CONVECTION EXPECT FOR PERHAPS LACK OF DEEPER MOISTURE. THE NEW
DAY 1 CONVECTIVE OUTLOOK STILL HAS ALL AREAS EAST OF THE MTNS IN THE
SLGT RISK...AND A MARGINAL RISK FOR THE MTNS. OTHERWISE...IT WILL BE
BREEZY TODAY UNDER MOSTLY CLOUDY TO PARTLY CLOUDY SKIES WITH TEMPS
BACK ABOVE NORMAL AHEAD OF THE FRONT.
TONIGHT...DRY AIR WILL FILTER IN FROM THE WEST BEHIND THE FRONT.
POPS WILL TAPER OFF...LINGERING THRU THE EVENING ALONG THE TN BORDER
DUE TO UPSLOPE NWLY FLOW. LOWS WILL BE A COUPLE CATEGORIES ABOVE
NORMAL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM MONDAY...THINGS DRY OUT TUE AS DRY HIGH PRESSURE BUILDS
IN FROM THE WEST. EXPECT A MILD AND BREEZY DAY WITH HIGHS UP TO 5
DEGREES BELOW NORMAL. A BROAD AND LOW AMPLITUDE UPPER TROF SETS UP
ACROSS THE AREA FOR WED. WEAK SHORT WAVES MOVING THRU THE TROF WILL
HELP PUSH A WEAK COLD FRONT INTO THE AREA WED AND SOUTH OF THE AREA
WED NITE. THERE IS NOT A LOT OF DEEP MOISTURE WITH THIS SYSTEM AND
THE FORCING IS WEAK. THEREFORE...EXPECT SCT SHRA NEAR THE TN BORDER
WHERE THE MOISTURE IS DEEPEST AND WLY FLOW WILL HELP INCREASE
FORCING. ELSEWHERE...ONLY ISOLATED SHRA ARE EXPECTED...WITH LITTLE
CHC OF PRECIP SOUTH OF I-85. HIGHS WILL RISE TO NEAR NORMAL WED...
WITH LOWS NEAR NORMAL TUE NITE AND ABOVE NORMAL WED NITE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 AM MONDAY...AN UPPER TROF AXIS WILL SLIDE EAST OF THE AREA
THURSDAY ALLOWING FLAT RIDGING TO BUILD IN ON FRI. A SHORT WAVE
CROSSES THE AREA SATURDAY WITH ANOTHER BROAD AND LOW AMPLITUDE UPPER
TROF DEVELOPING ON SUNDAY.
HIGH PRESSURE BRIEFLY RETURNS TO THE AREA FRI BEFORE A STRONGER
STORM SYSTEM MOVES IN ON SATURDAY. PRECIP CHC SLOWLY RAMPS UP FRIDAY
WITH POTENTIALLY HEAVY PRECIP ON SATURDAY. DRY HIGH PRESSURE RETURNS
FOR SUNDAY. NEAR NORMAL HIGHS THURSDAY...FALL BELOW NORMAL FOR THE
REST OF THE PERIOD. LOWS BOUNCE AROUND FROM NEAR TO A LITTLE ABOVE
NORMAL.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...PLENTY OF IFR TO MVFR LVL STRATUS ACRS THE
PIEDMONT THIS MORNING...SHUD LIFT AND SCATTER OUT TO A VFR LVL
CUMULUS DECK BY 14-16Z TIME FRAME. A BAND OF WEAKENING SHRA AND TSRA
ARE ENTERING WRN NC AT THE TIME OF THE TAF ISSUANCE. THE 06Z NAM
SEEMS TO HAVE THE BEST HANDLE ON THIS CONVECTION...CARRYING AN AREA
OF -RA ACRS THE NC MTNS AND FOOTHILLS...CLIPPING THE UPSTATE SITES
THIS MORNING. WILL MENTION SHRA AT KAVL AND VCTS AT KAND. NOT ENUF
CONFIDENCE ON ANY IMPACT AT GMU/GSP/HKY TO MENTION. BY MIDDAY...SW
WINDS WILL BECOME GUSTY ACRS THE ENTIRE AREA. A COLD FRONT WILL BE
PUSHING IN FROM THE WEST THIS AFTN...WITH GENERALLY ISOLD TO WIDELY
SCATTERED TSRA EXPECTED TO DEVELOP JUST OUT AHEAD OF THE FRONT ACRS
THE PIEDMONT. WILL CONTINUE TO MENTION PROB30 STARTING AT 21Z. WINDS
WILL SHIFT TO WNW EAST OF THE MTNS...AND NW AT KAVL BEHIND THE FRONT
THIS EVENING...GRADUALLY DIMINISHING OVERNIGHT.
OUTLOOK...DRY HIGH PRESSURE WILL BUILD IN ACROSS THE REGION FOR THE
MIDDLE OF THE WEEK...LEADING TO LOW PRECIP/RESTRICTION CHANCES.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-12Z
KCLT MED 79% HIGH 100% HIGH 100% HIGH 100%
KGSP MED 79% HIGH 87% HIGH 100% HIGH 100%
KAVL HIGH 93% HIGH 100% HIGH 100% HIGH 100%
KHKY MED 79% HIGH 81% HIGH 100% HIGH 100%
KGMU MED 76% HIGH 92% HIGH 100% HIGH 100%
KAND MED 76% HIGH 98% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...ARK/CSH
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
655 AM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY BRINGING ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS. DRY HIGH PRESSURE BUILDS IN FOR TUESDAY
AND WEDNESDAY. ANOTHER COLD FRONT WILL PUSH IN FROM THE NORTHWEST ON
THURSDAY...POSSIBLY BRINGING SHOWERS BACK TO THE AREA. A STRONGER
STORM SYSTEM WILL MOVE IN FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM...WELL THE NEAR TERM MODELS AND CAMS ARE NOT DOING VERY
WELL WITH THE CONVECTION ENTERING OUR WESTERN ZONES EARLY THIS
MORNING. HAVE BUMPED UP POP IN THE WEST. STILL EXPECT WEAKENING AS
THE REMNANT PRECIP CROSSES THE AREA THRU THE MORNING HOURS. CANNOT
RULE OUT A STRONG OR MARGINALLY SEVERE STORM EARLY ON...BUT
OTHERWISE JUST SOME CG LIGHTNING AND DOWNPOURS WITH THAT ACTIVITY.
THE REST OF THE FCST WAS LEFT UNCHANGED.
AS OF 330 AM...IN THE IMMEDIATE NEAR TERM...THE RADAR HAS GONE INTO
CLEAR AIR MODE...AS A LEAD SHORTWAVE HAS EXITED TO THE NE WITHIN
DEEP LAYER SWLY FLOW. A QUASI-LINEAR MCS IS CURRENTLY CROSSING
CENTRAL TN AND NRN AL. GUIDANCE SEEMS TO BE UNDERESTIMATING THE
STRENGTH/PERSISTENCE OF THIS SYSTEM. THE LATEST RAP ANALYSIS SHOWS
500-1000 J/KG OF MUCAPE WITH 35-45 KTS OF EFFECTIVE SHEAR DOWNSTREAM
OF THIS CLUSTER. THIS RESULTS IN A /MCS MAINTENANCE/ PROB AT 70-80
PCT. SO IT IS NOW EXPECTED THAT THESE STORMS (WHILE STILL ON A
GRADUAL WEAKENING TREND) WILL LIKELY STILL SURVIVE INTO THE NC MTNS
EARLY THIS MORNING. GIVEN THE CURRENT STATE...CANNOT RULE OUT A
STRONG OR SEVERE STORM OR TWO...ESP IN GRAHAM/SWAIN...WHEN THE LINE
GETS INTO THE CWFA. FROM THERE...IT/S DIFFICULT TO SAY HOW MUCH
PRECIP WILL LINGER ACRS THE CWFA THIS MORNING. I HAVE BUMPED UP POP
IN THE WRN MTNS...BUT KEEP JUST A SHOTGUN CHC POP FOR THE REST OF
THE AREA THIS MORNING.
LATER TODAY...GUIDANCE IN GOOD AGREEMENT ON ANOTHER SPOKE OF
VORTICITY ROTATING AROUND THE BROAD CYCLONICALLY CURVED
FLOW...CROSSING THE CWFA FROM THE SOUTHWEST DURING THE PEAK-HEATING
AFTN HOURS. MEANWHILE...A COLD FRONT WILL PUSH INTO THE AREA THIS
AFTN. THE FRONT LOOKS TO ONLY HAVE MODEST LLVL CONVERGENCE.
HOWEVER...GIVEN THE STEEP MID LVL LAPSE RATES AND LINGERING BL
MOISTURE (DEWPTS IN THE MID 60S ACRS THE PIEDMONT). FAIRLY CONFIDENT
IN AT LEAST 40-50 PCT COVERAGE OF CONVECTION...MAYBE HIGHER TO THE
EAST. THE FCST SNDGS SHOW LONG BUT SLIGHTLY CURVED HODOGRAPHS WITH
1500-2500 J/KG OF UNCAPPED SBCAPE. SO EXPECT SOMEWHAT DISCRETE
STORMS INITIALLY...WITH POTENTIAL FOR SUPERCELLS. DEFINITELY WILL
BE A DAMAGING WIND AND HAIL THREAT...WITH AN ISOLD TORNADO THREAT
ACRS THE PIEDMONT THIS AFTN. THE HIGH RES MODELS DO NOT SEEM THAT
IMPRESSED WITH COVERAGE OR INTENSITY. I/M NOT SURE WHAT IS LIMITING
THEIR CONVECTION EXPECT FOR PERHAPS LACK OF DEEPER MOISTURE. THE NEW
DAY 1 CONVECTIVE OUTLOOK STILL HAS ALL AREAS EAST OF THE MTNS IN THE
SLGT RISK...AND A MARGINAL RISK FOR THE MTNS. OTHERWISE...IT WILL BE
BREEZY TODAY UNDER MOSTLY CLOUDY TO PARTLY CLOUDY SKIES WITH TEMPS
BACK ABOVE NORMAL AHEAD OF THE FRONT.
TONIGHT...DRY AIR WILL FILTER IN FROM THE WEST BEHIND THE FRONT.
POPS WILL TAPER OFF...LINGERING THRU THE EVENING ALONG THE TN BORDER
DUE TO UPSLOPE NWLY FLOW. LOWS WILL BE A COUPLE CATEGORIES ABOVE
NORMAL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM MONDAY...THINGS DRY OUT TUE AS DRY HIGH PRESSURE BUILDS
IN FROM THE WEST. EXPECT A MILD AND BREEZY DAY WITH HIGHS UP TO 5
DEGREES BELOW NORMAL. A BROAD AND LOW AMPLITUDE UPPER TROF SETS UP
ACROSS THE AREA FOR WED. WEAK SHORT WAVES MOVING THRU THE TROF WILL
HELP PUSH A WEAK COLD FRONT INTO THE AREA WED AND SOUTH OF THE AREA
WED NITE. THERE IS NOT A LOT OF DEEP MOISTURE WITH THIS SYSTEM AND
THE FORCING IS WEAK. THEREFORE...EXPECT SCT SHRA NEAR THE TN BORDER
WHERE THE MOISTURE IS DEEPEST AND WLY FLOW WILL HELP INCREASE
FORCING. ELSEWHERE...ONLY ISOLATED SHRA ARE EXPECTED...WITH LITTLE
CHC OF PRECIP SOUTH OF I-85. HIGHS WILL RISE TO NEAR NORMAL WED...
WITH LOWS NEAR NORMAL TUE NITE AND ABOVE NORMAL WED NITE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 AM MONDAY...AN UPPER TROF AXIS WILL SLIDE EAST OF THE AREA
THURSDAY ALLOWING FLAT RIDGING TO BUILD IN ON FRI. A SHORT WAVE
CROSSES THE AREA SATURDAY WITH ANOTHER BROAD AND LOW AMPLITUDE UPPER
TROF DEVELOPING ON SUNDAY.
HIGH PRESSURE BRIEFLY RETURNS TO THE AREA FRI BEFORE A STRONGER
STORM SYSTEM MOVES IN ON SATURDAY. PRECIP CHC SLOWLY RAMPS UP FRIDAY
WITH POTENTIALLY HEAVY PRECIP ON SATURDAY. DRY HIGH PRESSURE RETURNS
FOR SUNDAY. NEAR NORMAL HIGHS THURSDAY...FALL BELOW NORMAL FOR THE
REST OF THE PERIOD. LOWS BOUNCE AROUND FROM NEAR TO A LITTLE ABOVE
NORMAL.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...PLENTY OF IFR TO MVFR LVL STRATUS ACRS THE
PIEDMONT THIS MORNING...SHUD LIFT AND SCATTER OUT TO A VFR LVL
CUMULUS DECK BY 14-16Z TIME FRAME. A BAND OF WEAKENING SHRA AND TSRA
ARE ENTERING WRN NC AT THE TIME OF THE TAF ISSUANCE. THE 06Z NAM
SEEMS TO HAVE THE BEST HANDLE ON THIS CONVECTION...CARRYING AN AREA
OF -RA ACRS THE NC MTNS AND FOOTHILLS...CLIPPING THE UPSTATE SITES
THIS MORNING. WILL MENTION SHRA AT KAVL AND VCTS AT KAND. NOT ENUF
CONFIDENCE ON ANY IMPACT AT GMU/GSP/HKY TO MENTION. BY MIDDAY...SW
WINDS WILL BECOME GUSTY ACRS THE ENTIRE AREA. A COLD FRONT WILL BE
PUSHING IN FROM THE WEST THIS AFTN...WITH GENERALLY ISOLD TO WIDELY
SCATTERED TSRA EXPECTED TO DEVELOP JUST OUT AHEAD OF THE FRONT ACRS
THE PIEDMONT. WILL CONTINUE TO MENTION PROB30 STARTING AT 21Z. WINDS
WILL SHIFT TO WNW EAST OF THE MTNS...AND NW AT KAVL BEHIND THE FRONT
THIS EVENING...GRADUALLY DIMINISHING OVERNIGHT.
OUTLOOK...DRY HIGH PRESSURE WILL BUILD IN ACROSS THE REGION FOR THE
MIDDLE OF THE WEEK...LEADING TO LOW PRECIP/RESTRICTION CHANCES.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-06Z
KCLT MED 78% MED 69% HIGH 100% HIGH 100%
KGSP HIGH 85% MED 69% LOW 57% HIGH 100%
KAVL HIGH 93% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 87% HIGH 100% HIGH 100%
KGMU HIGH 85% MED 69% HIGH 100% HIGH 100%
KAND HIGH 85% MED 75% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...ARK
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1206 PM EDT MON APR 20 2015
.SYNOPSIS...
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL ACCOMPANY A
COLD FRONT LATE TODAY AND THIS EVENING. THE COLD FRONT WILL CROSS
THE AREA TONIGHT. HIGH PRESSURE BUILDS BACK IN FROM THE SOUTHWEST
ON TUESDAY. ANOTHER COLD FRONT CROSSES THE AREA WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST WX ANALYSIS DEPICTS WARM FRONT JUST NORTH OF THE LOCAL AREA
WITH A TRAILING COLD FRONT EXTENDING FROM ~985MB LOW PRESSURE
OVER THE GREAT LAKES SWD TO THE LOWER MS VALLEY. ALOFT...UPPER LOW
HAS LOCATED OVER THE UPPER MIDWEST WITH TROUGH AXIS EXTENDING SWD
ALONG THE MS VALLEY. LATEST REGIONAL RADAR MOSAIC DEPICTS LAST
NIGHTS SHOWERS WELL OFFSHORE WITH DRY CONDITIONS OVER MUCH OF THE
MID-ATLANTIC REGION. SKIES AVG MOSTLY CLOUDY.
FOR TODAY...SFC LOW LIFTS NWD INTO SRN ONTARIO THIS AFTERNOON AS
THE COLD FRONT APPROACHES THE LOCAL AREA. SEVERAL PERTURBATIONS IN
INCREASING SWLY FLOW ALOFT WILL LIFT TOWARD THE REGION. THE
AIRMASS OVER THE LOCAL AREA WILL BECOME INCREASINGLY WARM/MOIST
AND UNSTABLE...ESPECIALLY WITH A FEW HOLES IN THE CLOUD COVER
EXPECTED THIS AFTERNOON. THETA E ADVECTION ALONG WITH TEMPS IN THE
LOW-MID 80S AND DEWPOINTS AROUND 60 WILL RESULT IN A MARGINALLY
UNSTABLE AIRMASS...WITH MLCAPE VALUES PER RAP GUIDANCE IN THE
1000-1500 J/KG RANGE. MODELS ALSO INDICATE VERY LITTLE MLCIN.
WHILE THERE WILL BE VERY LITTLE INHIBITION THIS AFTERNOON...EXPECT
PRECIP TO STAY TIED TO THE FRONT/CONVERGENCE ZONE. EXPECT
MOISTURE ADVECTION TO RAMP UP IN ADVANCE OF THE FRONT...WITH
PRECIP WATERS APPROACHING 1-1.25 INCHES.
COLD FRONT REACHES THE ERN VA PIEDMONT MID-LATE AFTERNOON. HI-RES
GUIDANCE INDICATING VERY LITTLE CONVECTION ALONG THE FRONT AS IT
CROSSES THE CNTRL APPALACHIANS...BUT ONCE THE FRONT REACHES THE
AIRMASS OVER THE PIEDMONT...MODELS INDICATE INITIATION AROUND
3-5PM THIS AFTERNOON OVER THE PIEDMONT. MODE EXPECTED TO START
OFF AS DISCRETE CELLS...BUT 30-40 KT OF EFFECTIVE BULK SHEAR WILL
TRANSITION TO A LINE FROM THE PIEDMONT INTO CNTRL VIRGINIA. QUICK
W-SW MID LEVEL FLOW WILL PUSH STORMS QUICKLY TO THE E-NE...WITH
THE BEST CHANCES REMAINING ALONG THE INSTABILITY AXIS FROM THE
PIEDMONT INTO CNTRL VA. STORMS PROGGED TO REACH CNTRL VA LATE
TODAY-EARLY THIS EVENING...AND THEN POINTS EWD THRU THE EVENING.
WHILE MORE INSTABILITY IS PROGGED ACROSS THE SE...EVENING TIMING
AND DECREASING SHEAR IS NOT FAVORABLE TO MAINTAIN LINE SEGMENTS
INTO THAT AREA. HI-RES GUIDANCE ALSO BACKS THIS UP. HAVE INCREASED
POPS TO LIKELY ACROSS THE PIEDMONT NEWD TO THE MD ERN SHORE...WITH
HIGH END CHANCE SOUTH AND EAST. DAMAGING WIND GUSTS AND LARGE HAIL
ARE POSSIBLE THANKS TO DEEP INSTABILITY...FAVORABLE LAPSE RATES
AND A RELATIVELY LOW FREEZING LEVEL. TORNADO RISK REMAINS LOW
THANKS TO GOOD MIXING AND HIGH LCL HEIGHTS. THE BEST RISK FOR
SEVERE WEATHER WILL BE ACROSS THE LIKELY POP AREA WITH ISOLATED
STRONG TO SEVERE STORMS STILL POSSIBLE OVER THE SE. BRIEF HEAVY
RAINFALL ALSO EXPECTED...BUT MOVEMENT WILL LIMIT ANY FLOODING
POTENTIAL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
A COLD FRONT CROSSES THE FA TONIGHT WITH CHC POPS...THEN
DRYING/COOLER WESTERLY FLOW TAKING OVR INTO TUE. PARTLY/MOSTLY
SUNNY TUE WITH HIGH TEMPS IN THE UPR 60S TO NR 70 AT THE
COAST...AND LOW/MID 70S ELSEWHERE.
HIGH PRES MOVES TO NR THE SE CONUS COAST BY WED...PROVIDING WSW
FLOW AND CONTINUING MILD WX. A WEAK TROUGH WILL BE APPROACHING
FROM THE WNW...WHICH SHOULD RESULT IN INCREASING CLOUDS AND THE
POSSIBILITY OF AFTERNOON SHOWERS (ISOLD TSTMS). LOW TEMPS TUE NGT
MID 40S WEST AND NORTH TO LOW 50S SE. HIGH TEMPS WED IN THE
LOW/MID 70S...EXCEPT 60S AT THE IMMEDIATE COAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
BROAD CYCLONIC FLOW PREVAILS THRU THE EXTENDED PERIOD AS UPPER
CLOSED LOW REMAINS IN VIC OF THE GREAT LAKES AND NEW ENGLAND. TO
BEGIN THE PERIOD...FAST MOVING COLD FRONT CROSSES THE REGION LATE
WEDS NIGHT-EARLY THURS MORNING. GFS CONTINUES TO REMAIN ON THE
SLOWER SIDE OF MODEL GUIDANCE WRT FRONTAL PASSAGE...WITH THE ECMWF
QUICKER. BASED ON WLY FLOW ALOFT AND HIGH PRESSURE BACK OVER THE
MIDWEST...OPTED TO REINTRODUCE SLIGHT CHANCE POPS WEDS NIGHT OVER
THE NRN AND NERN ZONES AND THEN THURS SOUTH AND EAST OF
RICHMOND...TRENDING SLIGHTLY TOWARD THE SLOWER GFS. HIGHS THURS
AROUND NORMAL...LOW-MID 60S. THEREAFTER...COOL HIGH PRESSURE BUILDS
SWD FROM THE CANADIAN PRAIRIES INTO THE MIDWEST...EXTENDING INTO THE
MID-ATLANTIC REGION FRI. HIGHS FRI GENERALLY IN THE UPPER 50S NE TO
MID 60S SE UNDER A PARTLY CLOUDY SKY AND NWLY WINDS. SRN STREAM
SHORTWAVE PROGGED TO LIFT INTO THE MIDWEST FRI NIGHT-SAT WITH
ASSOCIATED SFC LOW FORECAST TO PROGRESS EWD ALONG A STATIONARY
BOUNDARY OVER THE GULF STATES SAT. MOISTURE RETURNS SAT TO GO ALONG
WITH OVERRUNNING AND WEAK PERTURBATIONS ALOFT. INCREASED POPS TO
SLIGHT CHANCE N TO CHANCE S. HIGHS SAT GENERALLY AROUND 60 ACROSS
THE REGION. SFC LOW MOVES OFF THE CAROLINA COAST SAT NIGHT...WITH
ANY REMAINING PRECIP EXPECTED ACROSS THE SE LOCAL AREA. HIGH
PRESSURE RETURNS SUN...BUT COOL CONDITIONS PERSIST WITH HIGHS IN THE
UPPER 50S NE TO LOW 60S SE.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
THE FRONTAL RAINBAND IS MOVING OFFSHORE THIS MORNING. CONDITIONS
ARE IMPROVING AND SHOULD CONTINUE THROUGH THE MORNING. CLOUD
COVER ACTUALLY SCATTERING OUT BY THIS AFTERNOON...ALONG WITH A
GUSTY SW WIND. A SECONDARY IMPULSE TRACKS ACROSS THE REGION LATE
THIS AFTERNOON AND EVENING BRINGING A CHC OF SHOWERS/TSTMS. ANY
TSTMS COULD CONTAIN STRONG WIND GUSTS. A COLD FRONT THEN MOVES OFF
THE COAST LATER TONIGHT...WITH HIGH PRESSURE BUILDING INTO THE
REGION TUESDAY...BEFORE MOVING OFFSHORE WEDNESDAY. A COLD FRONT
CROSSES THE AREA WEDNESDAY NIGHT WITH A SLIGHT CHC OF SHOWERS.
HIGH PRESSURE RETURNS THURSDAY AND FRIDAY.
&&
.MARINE...
LOW PRESSURE IS LIFTING NNE OVER THE GREAT LAKES EARLY THIS
MORNING...WITH SECONDARY LOW PRESSURE OVER THE MID ATLANTIC. 3 TO
5 FT WAVES IN THE MOUTH OF THE BAY WILL CONTINUE THROUGH THE
AFTN. SEAS HAVE RISEN TO 5-8FT...AND WILL LIKELY REACH 6-9FT EARLY
TODAY...BEFORE SLOWLY SUBSIDING LATER TODAY THROUGH TUESDAY. A
FRONTAL BOUNDARY IS PRESENTLY CROSSING THE AREA AND SHOULD MOVE
OFFSHORE BY 12Z (15Z FARTHER NE). EXPECT THE WIND TO BECOME
SOUTHERLY BEHIND THE FRONT WITH SPEEDS RELAXING TO 10-15KT.
INHERITED SCA FLAGS REMAIN AS IS. HOWEVER...THE RIVERS COULD
POTENTIALLY END EARLIER THAN THE CURRENT 10 AM TIME. THIS WILL BE
RECONSIDERED AT THE 11Z/7 AM UPDATE. OTHERWISE...A COLD FRONT
APPROACHES FROM THE W THIS AFTERNOON/EVENING...AND MOVES ACROSS
THE COAST LATE TONIGHT. THIS FRONT IS EXPECTED TO TRIGGER
SHOWERS/TSTMS...WHICH WILL HAVE THE POTENTIAL OF PRODUCING STRONG
WIND GUSTS. HIGH PRESSURE BUILDS ACROSS THE SOUTHEAST TUESDAY AND
WEDNESDAY AS LOW PRESSURE LINGERS OVER THE GREAT LAKES. A WEAK
COLD FRONT CROSSES THE REGION WEDNESDAY NIGHT WITH HIGH PRESSURE
RETURNING THURSDAY AND FRIDAY.
&&
.HYDROLOGY...
AVG QPF 0.75-2.00"...LOCALLY UP TO 2.50" OVR MOST OF THE RIVER
BASINS WILL RESULT IN RIVER LVLS TO PSBLY RISE TO 1/2-NR FULL
BANKFULL TUE INTO WED.
&&
.TIDES/COASTAL FLOODING...
SOUTHERLY FLOW TODAY INTO THIS EVENING WILL HELP MAINTAIN ~1.0 FT
ANOMALIES IN THE MIDDLE BAY THROUGH TONIGHT. TIDAL ANOMALIES WILL
BEGIN TO SUBSIDE TUESDAY AS THE FLOW BECOMES OFFSHORE. NO
STATEMENTS HAVE BEEN ISSUED AT THIS TIME...BUT BISHOPS HEAD WILL
COME CLOSE TO THEIR 3.25FT MINOR THRESHOLD.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ634.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT TUESDAY FOR ANZ654-656-658.
SMALL CRAFT ADVISORY UNTIL 1 PM EDT TUESDAY FOR ANZ650-652.
&&
$$
SYNOPSIS...JDM
NEAR TERM...JDM/SAM
SHORT TERM...ALB/JDM
LONG TERM...SAM
AVIATION...AJZ
MARINE...AJZ
HYDROLOGY...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1025 AM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION TODAY AND BRING SHOWERS
AND SOME STRONG THUNDERSTORMS TO THE REGION. WE WILL THEN SETTLE
INTO A COOLER...BREEZY...AND SOMEWHAT UNSETTLED PATTERN THROUGH
THE MIDDLE OF THE WORKWEEK...WITH THE BEST CHANCE OF MORE SHOWERS
AND THUNDERSTORMS ARRIVING WITH ANOTHER FRONT ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1024 AM EDT MONDAY...
ACTIVE WEATHER DAY WITH LINGERING FLOODING ISSUES FROM SUNDAY TO
SUNDAY NIGHT HEAVY RAINS AND A SEVERE WEATHER THREAT FOR THIS
AFTERNOON INTO TONIGHT WITH COLD FRONT. SWODY1 HAS ADDED AN
ENHANCED POTENTIAL (30 PERCENT) TO SLIGHT RISK WHICH COVERS MUCH
OF OUR FORECAST AREA TODAY. THE MAIN THREATS FOR THUNDERSTORMS
PRODUCING DAMAGING WINDS AND LARGE HAIL...ALONG WITH LOCALLY HEAVY
RAIN. MODIFIED MORNING 12Z RNK SOUNDING SUPPORTS CONCERNS WITH
MODIFIED CAPES AROUND 1000 TO 2000 J/KG WITH HEALTHY SHEAR AROUND
40 KNOTS. ADJUSTED TIMING OF POPS CLOSER TO A BLEND OF HRRR AND
WRFRNK-ARW. MODIFIED TEMPERATURES AND DEW POINTS WITH SFC OBS AND
MODEL TRENDS. COLD FRONT PUSHES EAST ACROSS REGION THIS AFTERNOON
INTO THIS EVENING...THEN HIGH PRESSURE BUILDS IN BEHIND FRONT
TUESDAY. MORE CHANGES THIS AFTERNOON...
AS OF 525 AM EDT MONDAY...
THERE ARE LINGERING HYDRO ISSUES EARLY THIS MORNING FOLLOWING THE
WIDESPREAD HEAVY RAIN FROM SUNDAY AND SUNDAY NIGHT...AND SEVERAL
FLOOD WARNINGS REMAIN IN EFFECT FROM THE NORTH CAROLINA MOUNTAINS
THROUGH THE GRAYSON HIGHLANDS AND INTO SOUTHWEST VIRGINIA UNTIL
AROUND 9AM. THE SITUATION WILL CONTINUED TO BE MONITORED WITH
ADJUSTMENTS MADE ACCORDINGLY.
THE NEXT CONCERN IS THE APPROACHING COLD FRONT SET TO CROSS THE
AREA THIS AFTERNOON. MESO MODELS DISSIPATE THE CONVECTIVE COMPLEX
CURRENTLY APPROACHING FROM THE WEST WITH REDEVELOPMENT FIRING
LATER THIS MORNING INTO THIS AFTERNOON ACROSS THE REGION...
ESPECIALLY FRONT HE BLUE RIDGE EAST. EARLY MORNING SATELLITE PICS
SHOW BREAKS IN THE CLOUD COVER AND WITH 850MB TEMPS AROUND 12C WE
SHOULD SEE SURFACE TEMPERATURES RISE WELL INTO THE 70S TODAY. THIS
WILL GENERATE CAPE VALUES OF 1000J/KG TO 1500J/KG WHICH WILL BE
ENOUGH TO SUPPORT VIGOROUS CONVECTION. LOW LEVEL WINDS WILL GIVE
US 0/6KM BULK SHEAR VALUES OF 40KTS TO 50KTS WITH A SOMEWHAT
LINEAR HODOGRAPH. THUS THERE IS ENOUGH INSTABILITY AND SHEAR
PRESENT FOR A SEVERE THREAT...AND THE SPC SLIGHT RISK LOOKS TO BE
ON TARGET. WILL BE ANTICIPATING STORM CLUSTERS EVOLVING INTO
LINEAR ELEMENTS TO PRODUCE A WIND THREAT...AND THE MORE VIGOROUS
CELLS SHOULD HAVE ENOUGH CAPE IN THE HAIL GROWTH ZONE TO SUPPORT
LARGE HAIL POTENTIAL AS WELL. WHILE SWATS REMAIN HIGH BELIEVE ANY
HEAVY RAIN WILL BE LOCALIZED AND FURTHER EAST WHICH SHOULD HELP
AVOID AGGRAVATING THE HYDRO SITUATION. ENOUGH INGREDIENTS FOR A BUSY
AFTERNOON ON RADAR.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 525 AM EDT MONDAY...
BEHIND THE FRONT WE START TO SETTLE INTO A COOLER...BREEZY...AND
SOMEWHAT UNSETTLED PATTERN AS A BROAD CLOSED LOW TAKES UP
RESIDENCE OVER THE GREAT LAKES. THE FRONT WILL PUSH OFF TO OUR
EAST EARLY TONIGHT AND TAKE THE SHOWERS AND THUNDERSTORMS WITH
IT...LEAVING SOME UPSLOPE SHOWERS ACROSS THE FAR WEST FOR THE
OVERNIGHT. ANY LINGERING PRECIPITATION WILL DISSIPATE EARLY
TUESDAY MORNING AND TUESDAY LOOKS TO BE MOSTLY DRY. COULD SEE THE
OUTSIDE POSSIBILITY OF COOKING UP SOME SHOWERS ON TUESDAY
AFTERNOON BUT BELIEVE THE POPS ARE TOO SMALL TO MENTION SO WILL
KEEP THINGS UNDER 15 PERCENT. ANOTHER FRONT WILL ROTATE THROUGH
THE REGION ON WEDNESDAY AND WILL HAVE SOME SLIGHT INSTABILITY AND
STEEP LAPSE RATES TO WARRANT A MENTION OF THUNDER. WEAK HIGH
PRESSURE WILL THEN BUILD IN WEDNESDAY NIGHT AND BRING WHAT LOOKS
TO BE MOSTLY DRY WEATHER FOR THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...
BROAD UPPER TROUGH REMAINS IN PLACE AND DOMINATES THE EXTENDED
FORECAST...GRADUALLY SHIFTING FURTHER ESE LATE IN THE PERIOD.
THIS KEEPS THE REGION IN AN UNSTABLE/UNSETTLED NORTHWEST FLOW WITH
NUMEROUS EMBEDDED SHORT WAVES. MODELS VARY CONSIDERABLY AS TO THE
TIMING AND PLACEMENT OF THESE DISTURBANCES...BUT ENOUGH AGREEMENT
THAT POPS CANNOT BE DROPPED REALLY AT ANY TIME THE OVERALL TREND
IS TO PUSH THE BETTER MOISTURE FURTHER SOUTH OF THE REGION AS THE
WEEK PROGRESSES AND 850MB TEMPS DROP BELOW 0C IN THE NORTHERN
COUNTIES. THE ENTIRE PERIOD SHOULD FEATURE BELOW NORMAL
TEMPERATURES WITH LOW CHC POPS...HIGHEST ACROSS THE MOUNTAINS AND
TOWARD THE SOUTHERN COUNTIES...WITH THE NORTHERN PIEDMONT THE
DRIEST. ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL THROUGHOUT THE
PERIOD...NO REAL CLEAR CONCERN AT THIS POINT FOR FROST/FREEZE
BECAUSE OF CYCLONIC FLOW AND CLOUDS.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 750 AM EDT MONDAY...
CLUSTER OF SHOWERS AND THUNDERSTORMS IN THE TENNESSEE VALLEY WILL
MOVE EAST INTO VIRGINIA AND SOUTHERN WEST VIRGINIA THIS MORNING.
BASED ON CURRENT RADAR TRENDS THIS PRECIPITATION WILL REACH KBLF
BEFORE 16Z.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE REGION
THIS AFTERNOON AHEAD OF A COLD FRONT. PRESSURE RISES BEHIND THE
FRONT WILL BRING BREEZY AND GUSTY WESTERLY WINDS TO THE AREA INTO
MONDAY NIGHT. THERE IS SLIGHT RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON EAST OF THE BLUE RIDGE...SO WIND GUSTS WITH ANY SEVERE
THUNDERSTORMS AT KLYH AND KDAN MAY APPROACH 50 KNOTS. DO NOT
EXPECT TO HAVE ANYTHING THAT INTENSE THAT FAR EAST UNTIL AFTER
18Z.
IN THE EVENING BEHIND THE FRONT...MODELS WERE INDICATING SOME MVFR
CEILINGS IN THE MOUNTAINS. ONLY MODERATE CONFIDENCE HOW LOW
CEILINGS WILL GET ONCE THE SHOWERS CLEAR OUT AFTER SUNSET.
EXTENDED AVIATION...
VFR RETURNS LATER TONIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...MBS
NEAR TERM...KK/MBS
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/RCS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
600 AM CDT MON APR 20 2015
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 400 AM CDT MON APR 20 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF
STRENGTHENING LOW PRESSURE MOVING NORTH OVER SOUTHWEST LOWER
MICHIGAN. COMMA HEAD PRECIP AROUND THE LOW IS NOW SHIFTING
NORTHWEST AND EXTENDS FROM WAUTOMA TO WAUSAUKEE. FARTHER
WEST...MID-LEVEL FRONTOGENESIS IS CREATING A BAND OF RAIN OVER
WESTERN WISCONSIN AHEAD OF AN UPPER TROUGH POSITIONED OVER
SOUTH-CENTRAL CANADA AND THE NORTHERN PLAINS. WINDS SHIFT TO THE
NORTHWEST OVER WESTERN WISCONSIN AND ARE GUSTING INTO THE LOWER 30
KTS. SOME SNOW BEING REPORTED OVER NORTHERN MINNESOTA AS WELL. AS
THE LOW CONTINUES TO LIFT TO THE NORTH AND THE UPPER TROUGH SETTLES
OVER THE GREAT LAKES...PRECIP TRENDS ARE THE MAIN FORECAST CONCERN.
TODAY...THE LOW PRESSURE SYSTEM WILL TRAVEL NORTHWARD OVER WESTERN
LOWER MICHIGAN INTO NORTHERN ONTARIO. MODELS INDICATE THAT COMMA
HEAD PRECIP ASSOCIATED WITH THE LOW WILL LIFT NORTH ACROSS THE
CENTRAL FORECAST AREA EARLY THIS MORNING AND ACROSS THE CENTRAL UPPER
PENINSULA LATER IN THE MORNING. MEANWHILE...THE FGEN INDUCED RAIN
BAND WILL PIVOT NORTHEAST ACROSS CENTRAL AND NORTH-CENTRAL WISCONSIN
THIS MORNING AND NORTHEAST WISCONSIN THIS AFTERNOON. THEREFORE
EXPECT PERIODS OF RAIN THROUGH THE MORNING...BEFORE THE RAIN
GRADUALLY EXITS TO THE NORTHEAST IN THE AFTERNOON.
ADDITIONALLY...WEST WINDS WILL DRIVE COLDER AIR ACROSS THE STATE
BEHIND THE SYSTEM WHICH WILL STEEPEN LOW LEVEL LAPSE RATES...AND
PROMOTE GUSTY WINDS DEVELOPING. SOME GUSTS OVER CENTRAL AND
EAST-CENTRAL WISCONSIN COULD EXCEED 30 MPH THIS AFTERNOON. WITH THE
RAIN AND CLOUDS...COOLER HIGHS IN THE MID 40S TO AROUND 50.
TONIGHT...MID-LEVEL DRY SLOTTING WILL BE ROTATING OVERHEAD DURING
THE EVENING BEFORE DEEPER MOISTURE RETURNS AS UPPER LEVEL LOW
PRESSURE SETTLES ACROSS THE REGION. MOISTURE WILL BE THE DEEPEST
OVER FAR NORTH-CENTRAL WISCONSIN FOR THE EVENING HOURS...WHERE WILL
CARRY LOW CHANCES OF PRECIP. THEN PRECIP CHANCES WILL INCREASE FROM
NORTHWEST TO SOUTHEAST THROUGH THE OVERNIGHT. SOUNDINGS COOL ENOUGH
OVERNIGHT FOR SNOW TO BECOME THE DOMINANT PTYPE OVER CENTRAL AND
NORTH-CENTRAL WISCONSIN FOR MINOR ACCUMULATIONS ON GRASSY SURFACES.
LOWS RANGING FROM THE LOW TO MID 30S.
TUESDAY...WITH UPPER LEVEL LOW PRESSURE OVERHEAD...PERIODS OF RAIN
AND SNOW SHOWERS LOOK TO OCCUR OVER NORTH-CENTRAL WISCONSIN. MINOR
SNOW ACCUMULATIONS ARE POSSIBLE ACROSS THE NORTH DURING THE
MORNING. CHANCES OF PRECIP WILL IMPROVE THROUGH THE MORNING OVER
EASTERN WISCONSIN WHERE PRECIP COULD BE A MIX OF RAIN AND SNOW
INITIALLY BEFORE TEMPS RISE WARM ENOUGH FOR ALL RAIN. COOL WITH
HIGHS RANGING FROM NEAR 40 NORTH TO THE UPPER 40S SOUTHEAST.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 400 AM CDT MON APR 20 2015
UPPER LOW ACROSS ONTARIO WILL GRADUALLY SHIFT EAST INTO QUEBEC BY
THE END OF THE WORK WEEK. COOL CYCLONIC FLOW WILL CONTINUE TO BRING
BELOW NORMAL TEMPERATURES INTO THE WEEKEND...ALONG WITH A CHANCE OF
RAIN OR SNOW SHOWERS AT TIMES TUESDAY NIGHT INTO THURSDAY. HIGHEST
CHANCES WILL BE ACROSS THE NORTH...IN CLOSER PROXIMITY TO THE UPPER
LOW AND SHORTWAVE ENERGY. CURRENT FORECAST IS DRY FOR FRIDAY...
BUT COULD NOT RULE OUT A STRAY RAIN/SNOW SHOWER ACROSS THE NORTH.
DRY CONDITIONS ARE EXPECTED THIS WEEKEND AS HIGH PRESSURE DOMINATES
THE WEATHER PATTERN. ONLY MINOR CHANGES MADE TO MAX/MIN TEMPERATURES
AND PRECIPITATION CHANCES.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 559 AM CDT MON APR 20 2015
STEADY RAIN WITH IFR AND LIFR CIGS WILL END FROM SOUTHWEST TO
NORTHEAST DURING THE AFTERNOON HOURS AS LOW PRESSURE SYSTEM AND
COLD FRONT EXIT THE REGION. AS THE RAIN ENDS...CONDITIONS WILL
EVENTUALLY IMPROVE BACK TO VFR IN THE AFTERNOON. A TIGHT PRESSURE
GRADIENT WILL LEAD TO GUSTY WESTERLY WINDS TODAY. THEN UPPER LEVEL
LOW PRESSURE WILL SETTLE OVER THE REGION TONIGHT WITH RAIN AND
SNOW SHOWERS...AND MVFR CIGS SPREADING SOUTHEAST ACROSS THE TAF
SITES.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS RENO NV
1020 AM PDT MON APR 20 2015
.AVIATION UPDATE...
FOR THE 18Z TAFS WE`VE ADDED BRIEF TEMPO GROUPS FOR TSTMS AT TVL/TRK
THIS AFTERNOON. LATEST GUIDANCE INCLUDING HRRR SUGGESTS ENOUGH OF A
RISK OF TSTMS TO ADD TEMPO FOR MVFR CONDITIONS AND GUSTY WINDS,
ABOUT A 60% CHANCE. HAVE ALSO ADDED SIMILAR TEMPO PERIODS AT RNO/CXP
FOR GUSTY OUTFLOW WINDS FROM TSTMS OVER THE SIERRA. WITH
SUFFICIENTLY DRY BOUNDARY LAYER ANY TSTMS SHOULD PRODUCE LARGE
OUTFLOWS AND LATEST HRRR RUNS ARE SHOWING THAT WIND MAKING IT INTO
THE RNO/CXP AREAS LATE THIS AFTERNOON. ADMITTEDLY CONFIDENCE IS ONLY
40% IN THAT HAPPENING BUT ENOUGH OF A RISK TO ADD IN THE TAF. CS
&&
.SYNOPSIS...
SCATTERED AFTERNOON SHOWERS AND ISOLATED THUNDERSTORMS WILL
DEVELOP IN THE SIERRA TODAY. LOW PRESSURE WILL MOVE INTO EASTERN
CALIFORNIA AND WESTERN NEVADA TUESDAY AND LAST THROUGH MUCH OF THE
WORK WEEK, BRINGING INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS
OUT INTO WESTERN NEVADA AS WELL AS COOLER TEMPERATURES AREA WIDE.
&&
.SHORT TERM...
CONVECTIVE DEVELOPMENT THIS AFTERNOON AND EVENING LOOKS FAIRLY
SIMILAR TO SUNDAY, WITH THE BULK OF THE SHOWERS AND ISOLATED
THUNDERSTORMS DEVELOPING NEAR THE CREST AND MOVING TO THE WEST
SLOPES OF THE SIERRA IN THE STEERING FLOW ALOFT. A DRY SUB-CLOUD
LAYER COULD PROMOTE GUSTY OUTFLOW WINDS TO AROUND 40 MPH WITH ANY
THUNDERSTORMS. LATE IN THE AFTERNOON YESTERDAY, A LARGE-SCALE
OUTFLOW FROM CONVECTION NEAR THE CREST WAS NOTED IN THE VISIBLE
SATELLITE NEAR THE CALIFORNIA-NEVADA BORDER IN EASTERN MONO
COUNTY. WEB CAMS LOOKING EAST FROM LEE VINING INDICATED IT MAINLY
PRODUCED SOME VIRGA OR A FEW STRAY RAINDROPS. THIS COULD CERTAINLY
OCCUR AGAIN TODAY OUT INTO EXTREME WESTERN NEVADA BUT MEASURABLE
PRECIPITATION IS NOT EXPECTED.
TUESDAY, LOW PRESSURE CURRENTLY OFF THE SOUTHERN CALIFORNIA COAST
WILL MOVE INLAND WHILE THE UPPER RIDGE NEAR THE OREGON COAST TODAY
SHIFTS TO NEAR THE IDAHO BORDER. THIS WILL CAUSE THE UPPER FLOW TO
TURN AROUND TO A MORE SOUTHERLY DIRECTION OVER NORTHEAST CALIFORNIA
AND WESTERN NEVADA. THE SOUTHERLY STEERING FLOW AND SOME LOWER
LEVEL WEST WIND CONVERGENCE IN THE IMMEDIATE LEE OF THE SIERRA
SHOULD ALLOW SHOWERS AND THUNDERSTORMS TO FORM ON THE SIERRA AND
MOVE NORTH AND EAST INTO WESTERN NEVADA DURING THE LATE AFTERNOON
AND EVENING ON TUESDAY. THUNDERSTORMS DO NOT LOOK OVERLY STRONG
BASED ON MODEL INSTABILITY AND SHEAR. HOWEVER, AS WITH MONDAY, ANY
THUNDERSTORMS COULD DROP WIND GUSTS TO 40 MPH OR SO ALONG WITH
BRIEF LIGHT TO MODERATE RAINFALL.
WEDNESDAY, LOTS OF DEBRIS CLOUDS FROM TUESDAY`S CONVECTION MAY
COMBINE WITH UPPER DIVERGENCE/LIFT TO THE NORTH OF THE UPPER LOW
(OVER SOUTHEAST CALIFORNIA) TO BRING WIDESPREAD CLOUD COVER. THIS
WILL TEND TO REDUCE INSTABILITY WITH COOLER AFTERNOON TEMPERATURES
AND CAUSE THE CHANCE FOR THUNDERSTORMS TO WANE. STILL, SCATTERED
SHOWERS ARE EXPECTED FOR WEDNESDAY AFTERNOON WITH INCREASING
MOISTURE AND SOME MODEST UPPER FORCING. SNYDER
.LONG TERM...THURSDAY THROUGH SUNDAY...
FEW CHANGES MADE WITH SHOWERS LOOKING TO CONTINUE INTO THURSDAY WITH
A COUPLE THUNDERSTORMS POSSIBLE AS THE UPPER LOW EJECTS INTO ARIZONA.
A DRIER WEST TO NORTHWEST FLOW FRIDAY WILL PUSH MUCH OF THE MOISTURE
EASTWARD AS A STRONGER LOW MOVES INTO WASHINGTON. A FEW SHOWERS
REMAIN POSSIBLE, BUT WITH THE DRYING AND SOME WARMING ALOFT IT LOOKS
MUCH LESS LIKELY THAN AT THIS TIME YESTERDAY.
A MORE ZONAL FLOW IS EXPECTED FOR NEXT WEEKEND, ALTHOUGH THE SIERRA
AND WESTERN NEVADA SHOULD BE UNDER A SHORT WAVE RIDGE. THIS WILL BE
AHEAD OF A DEEPENING TROUGH NEAR 135W. THEREFORE, DO NOT EXPECT MUCH
IF ANYTHING IN THE WAY OF PRECIPITATION AS THE WEAK ATMOSPHERIC
RIVER IS POINTED INTO WASHINGTON. REGARDING TEMPERATURES, IT WILL
WARM SLIGHTLY BUT OVERALL WILL REMAIN CLOSE TO AVERAGE VALUES FOR
LATE APRIL. WALLMANN
&&
.AVIATION...
A FEW THUNDERSTORMS EXPECTED AGAIN THIS AFTERNOON ALONG THE SIERRA
CREST FROM MAMMOTH MTN TO LASSEN PEAK FROM 20-03Z. LOCAL MVR CONDS
POSSIBLE WITH GUSTY OUTFLOW WINDS. THESE STORMS HAVE ABOUT A 20-30
PCT CHANCE OF IMPACTING KMMH-KTVK-KTRK. ELSEWHERE, VFR CONDITIONS
EXPECTED WITH LIGHT WINDS. MORE STORMS ARE POSSIBLE AROUND THE SAME
TIME TUESDAY AFTERNOON WITH KRNO/KCXP POSSIBLY AFFECTED. WALLMANN
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS PUEBLO CO
318 PM MDT MON APR 20 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 318 PM MDT MON APR 20 2015
CURRENTLY...
MODEST NW FLOW PREVAILS ALOFT ACROSS THE REGION. ISOLD TO SCTD SHRA
AND -TSRA WERE NOTED OVER THE HIGHER TRRN AND WERE MOVING ONTO THE
PLAINS. MOST UNSTABLE ATMOSPHERE WAS NOTED OVER THE SPANISH PEAKS
REGION PER RADAR AND TOTAL LTG DATA. TEMPS WERE COOL AT 3 PM WITH
TEMPS IN THE U50S/L60S PLAINS AND 50S VALLEYS.
REST OF TODAY AND THIS EVENING....
ISOLD PRECIP ACTIVITY WILL CONTINUE OVER THE HIGHER TRRN WITH SOME
OF THIS ACTIVITY MOVING ONTO THE PLAINS. ANY ACTIVITY OVER THE PLAINS
WILL GENERALLY REMAIN ISOLD...WITH A BIT MORE COVERAGE EXPECTED
ALONG THE CO/NM BORDER. ACTIVITY WILL REMAIN WEAK WITH BIGGEST
CONCERN BEING CG ACTIVITY.
TONIGHT...
ANY PRECIP OVER THE REGION WILL DIE BY LATER THIS EVENING IF NOT
EARLIER. HRRR AND NAM GUIDANCE DO SHOW A TSTORM OR TWO OVER THE
PLAINS EARLY THIS EVENING UNDER THE MODEST NW FLOW. TEMPS WILL COO
INTO THE 30-35F RANGE ACROSS THE PLAINS WITH 20S IN THE VALLEYS.
TUESDAY...
IT WILL BE WARMER TOMORROW WITH HIGHS EXPECTED TO REACH INTO THE
LOWER 70S MOST OF THE PLAINS...AND 60S VALLEYS. I DO EXPECT THAT WE
WILL SEE A PRECIP PATTERN SIMILAR TO TODAY IN THAT SHOWERS AND
STORMS WILL FORM OVER THE MTNS AND MOVE ONTO THE PLAINS. ACTIVITY
WILL BE A LITTLE MORE ROBUST TOMORROW AS WE SHOULD SEE A BIT MORE
INSTABILITY TOMORROW...HOWEVER NO STRONG ACTIVITY IS ANTICIPATED AT
THIS TIME. /HODANISH
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 318 PM MDT MON APR 20 2015
RELATIVELY ACTIVE LONGER TERM IS ANTICIPATED WITH PRIMARY
METEOROLOGICAL ISSUES BEING POPS(INCLUDING THUNDERSTORMS
AND MOUNTAIN SNOWS)...TEMPERATURES AND GUSTY WINDS AT TIMES.
RECENT LONGER TERM COMPUTER SIMULATIONS...FORECAST MODEL
SOUNDINGS...PV ANALYSIS AND ADDITIONAL METEOROLOGICAL PARAMETERS
SUGGEST THAT TRANSITORY UPPER RIDGING TO SOUTHWESTERLY UPPER
FLOW WILL BE IN PLACE OVER THE FORECAST DISTRICT FROM TUESDAY
NIGHT INTO THURSDAY IN ADVANCE OF NEXT UPPER DISTURBANCE
IMPACTING CWFA FROM LATER THURSDAY INTO FRIDAY NIGHT WITH
ANOTHER UPPER DISTURBANCE IMPACTING THE FORECAST DISTRICT
FROM SATURDAY INTO SATURDAY NIGHT.
AT LOWER LEVELS...SURFACE HIGH CENTERED OVER SOUTH DAKOTA AT 06Z
WEDNESDAY SLOWLY SHIFTS INTO THE UPPER MIDWEST BY FRIDAY
NIGHT...WHILE SURFACE LOW DEVELOPS OVER SOUTHEASTERN COLORADO BY
06Z FRIDAY BEFORE SHIFTING INTO OKLAHOMA BY 06Z SATURDAY AS
NORTHERLY SURFACE SURGE PUSHES ACROSS EASTERN SECTIONS FRIDAY
NIGHT.
THE COMBINATION OF THESE METEOROLOGICAL PARAMETERS IN
COMBINATION WITH ADEQUATE ATMOSPHERIC MOISTURE WILL ALLOW FOR
UNSETTLED CONDITIONS AT TIMES OVER THE CWFA DURING THE
MAJORITY OF THE LONGER TERM IN COMBINATION WITH TEMPERATURES
RUNNING WITHIN A CATEGORY OR SO OF MID TO LATE APRIL
CLIMATOLOGICAL AVERAGES MOST LOCATIONS...ALTHOUGH SOME
ADDITIONAL WARMING IS PROJECTED TO DEVELOP BY EARLY NEXT WEEK.
AT THIS TIME...IT APPEARS THAT THE HIGHEST POTENTIAL OF STRONGER
CONVECTIVE POTENTIAL DURING THE LONGER TERM MAY BE REALIZED
WEDNESDAY AND THURSDAY(ESPECIALLY EASTERN SECTIONS) AS DEEPER
ATMOSPHERIC MOISTURE INTERACTS WITH UPPER IMPULSES TO PRODUCE
LOCALIZED POTENTIAL CAPES/LIS AND BULK SHEARS VALUES OF -5C/1000+
J/KG AND 40 KNOTS RESPECTIVELY BOTH DAYS. AS ALWAYS...WFO PUEBLO
WILL MONITOR CLOSELY.
IN ADDITION...HIGHER ELEVATION ACCUMULATING SNOW IS ANTICIPATED
AT TIMES WITH GUSTY GRADIENT WINDS ALSO POSSIBLE...PRIMARILY FROM
FRIDAY INTO FRIDAY NIGHT. FINALLY...AS BRIEFLY TOUCHED UPON
EARLIER...WARMEST CONDITIONS DURING THE LONGER TERM SHOULD BE
NOTED BY NEXT MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 318 PM MDT MON APR 20 2015
VFR CONDITIONS ARE ANTICIPATED DURING THE NEXT 24H AT ALL 3 TAF
SITES...KPUB...KALS AND KCOS. VERY ISOLD TSRA WILL BE POSSIBLE THIS
EVENING AND TOMORROW EVENING AT KCOS AND KPUB. WINDS WILL BE
DIURNALLY DRIVEN AND WILL BE LIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBANY NY
205 PM EDT MON APR 20 2015
.SYNOPSIS...
OCCASIONAL PERIODS OF RAIN ARE EXPECTED ACROSS EASTERN
NEW YORK AND WESTERN NEW ENGLAND THIS AFTERNOON INTO TONIGHT...AS A
LOW PRESSURE SYSTEM TRACKS INTO THE GREAT LAKES...AND A
FRONTAL SYSTEM ASSOCIATED WITH THE LOW APPROACHES FROM THE WEST.
EAST TO SOUTHEAST WINDS WILL BECOME STRONG AND GUSTY TODAY AHEAD OF
THE SYSTEM. A FEW RUMBLES OF THUNDER WILL BE POSSIBLE TONIGHT AS THE
FRONT PASSES. SOME BREAKS IN THE CLOUDS WILL DEVELOP TUESDAY
AFTERNOON BEHIND THE FRONT...OTHERWISE GENERALLY COOL AND SOMEWHAT
UNSETTLED CONDITIONS WILL PERSIST THROUGH THE REMAINDER OF THE WEEK
...AS A LARGE UPPER LEVEL LOW REMAINS ANCHORED NORTH OF THE GREAT
LAKES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1230 PM EDT...THE SURGE OF WARM ADVECTION PRECIPITATION
AHEAD OF THE WARM OVER THE UPPER MID ATLANTIC REGION IS MOVING
ACROSS THE SOUTHEAST PORTION OF THE FA WITH SCATTERED SHOWERS
ACROSS THE REMAINDER OF THE FA. ONGOING FORECAST IS IN PRETTY
GOOD SHAPE WITH JUST SOME RETOOLING OF THE POPS...AND HOURLY TEMPS
BASED ON THE RADAR AND OBSERVATIONS TRENDS. THERE IS GOOD SUPPORT
FROM THE LATEST HRRR FOR THE PCPN TO EXPAND NORTHWARD INTO THE
CAPITAL REGION...NRN CATSKILLS...MOHAWK VALLEY...SRN VT CORRIDOR.
SOME DOWNSLOPING DUE TO THE STRONG E/SE LLJ MAY LIMIT THE MODERATE
RAINFALL EXPANSION INTO THE UPPER HUDSON REGION...AND WEST OF THE
SRN GREENS. THE HIGHER TOTALS OF A THIRD TO TWO THIRDS OF AN INCH
OF RAINFALL ARE EXPECTED AND EAST OF THE CAPITAL REGION.
THE STEADIER RAIN SHOULD TAPER TO SHOWERS AND SOME DRIZZLE FOR
THIS AFTERNOON AS THE LOW LEVEL JET AND STRONGEST ISENTROPIC LIFT
PASS NORTH AND EAST OF THE REGION. SOUTH/EAST FACING HIGHER
ELEVATIONS WILL BE MOST PRONE TO MORE PERSISTENT SHOWERS AND
DRIZZLE THIS AFTERNOON.
GUSTY EAST/SOUTHEAST WINDS HAVE DEVELOPED LATE THIS MORNING AS
THE LOW LEVEL JET AND TIGHT PRESSURE GRADIENT PASS THROUGH. SOME
GUSTS OF 30-40 MPH HAVE BEEN NOTED AT KDDH AND KAQW. THE BEST
CHANCE FOR STRONGER WINDS TO MIX DOWN WILL BE ACROSS HIGHER
TERRAIN OF THE TACONICS...SOUTHERN GREEN MTNS...AND
BERKSHIRES...WHERE SOME GUSTS OF 50-55 MPH MAY OCCUR...ESP FROM
THE LATE MORNING THROUGH EARLY AFTERNOON. WIND GUSTS OF 35-45 MPH
WILL ALSO BE LIKELY ACROSS PORTIONS OF THE WESTERN
ADIRONDACKS...MOHAWK VALLEY AND EASTERN CATSKILLS. IN MOST VALLEY
AREAS...SOME WIND GUSTS OF 25-35 MPH COULD OCCUR EARLY THIS
MORNING AS THE RAIN INITIALLY REACHES THE GROUND. HOWEVER...THE
BOUNDARY LAYER SHOULD THEN STABILIZE ONCE WET BULB COOLING
OCCURS INTO THE AFTERNOON...DIMINISHING THE THREAT OF STRONGER
WINDS MIXING DOWN TO THE VALLEY FLOOR.
TEMPS WILL MAINLY BE IN THE 40S TO ABOUT 50F OVER THE HIGHER
TERRAIN...AND LOWER TO MID 50S IN THE VALLEY AREAS...EXCEPT IN THE
UPPER HUDSON REGION/LAKE GEORGE REGION AND PARTS OF SRN VT WHERE
SOME OF THE MAX TEMPS MAY ONLY REACH THE UPPER 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...A WARM FRONT WILL SLOWLY ATTEMPT TO LIFT NORTHWARD FROM
THE MID ATLANTIC STATES...AS A COLD/OCCLUDED FRONT APPROACHES FROM
THE GREAT LAKES REGION. ALTHOUGH THE PARENT LOW IS EXPECTED TO
TRACK ACROSS THE GREAT LAKES REGION TONIGHT...A WEAK TRIPLE POINT
LOW MAY FORM ALONG THE JUNCTION OF THE RETREATING WARM FRONT...AND
APPROACHING COLD FRONT FROM THE WEST...SOMEWHERE OVER SOUTH
CENTRAL PA. MODELS SUGGEST THAT SOME ELEVATED INSTABILITY...WITH
SHOWALTER INDICES DIPPING INTO THE -1C TO -3C RANGE OVERSPREADS AT
LEAST THE WESTERN AND SOUTHERN HALF OF THE REGION
OVERNIGHT...WHICH...IN COMBINATION WITH SYNOPTIC LIFT AHEAD OF THE
APPROACHING FRONTS...AND SOME QG FORCING AHEAD OF AN VORT LOBE
APPROACHING FROM THE SOUTHWEST...MAY ALLOW FOR A ROUND OF ELEVATED
CONVECTION LATER THIS EVENING AND OVERNIGHT...ESP FOR AREAS NEAR
AND SOUTH OF INTERSTATE 90. SO...SOME RUMBLES OF THUNDER ARE NOT
OUT OF THE QUESTION. ANY THUNDERSTORMS ARE EXPECTED TO REMAIN
NON-SEVERE ACROSS OUR REGION...WHICH IS IN AGREEMENT WITH LATEST
SPC DAY 1 OUTLOOK...WHICH KEEPS OUR AREA IN THE GENERAL THUNDER
REGION. HOWEVER...ANY THUNDERSTORMS THAT OCCUR OVERNIGHT COULD
HAVE LOCALLY HEAVY DOWNPOURS. TEMPS ARE EXPECTED TO HOLD NEARLY
STEADY MOST OF THE NIGHT...BEFORE FALLING INTO THE 40S CLOSER TO
DAYBREAK.
TUESDAY...SOME LINGERING SHOWERS WILL BE POSSIBLE IN THE MORNING
AS THE AFOREMENTIONED VORT LOBE SWINGS ACROSS. THEN...IT APPEARS
THAT OUR REGION WILL EXPERIENCE A PERIOD OF SUBSIDENCE IN THE
AFTERNOON HOURS...WHEN SOME BREAKS OF SUN COULD OCCUR. SOME LOW
LEVEL INSTABILITY COULD ALLOW FOR ISOLATED SHOWERS TO DEVELOP
LATER IN THE AFTERNOON...MAINLY ACROSS THE WESTERN ADIRONDACK
REGION. MAX TEMPS ARE FORECAST TO REACH THE LOWER/MID 60S IN
VALLEY AREAS AND 50S ACROSS HIGHER ELEVATIONS.
TUE NT-WED...ANOTHER REINFORCING COLD FRONT AND UPPER LEVEL
SHORTWAVE ARE EXPECTED TO CROSS THE REGION ON WED. WEAK RIDGING
JUST AHEAD OF THIS FEATURE MAY ALLOW FOR SOME BREAKS IN THE CLOUDS
TO CONTINUE INTO EARLY TUE NT...BEFORE CLOUDS REDEVELOP...AND
SHOWERS OVERSPREAD THE REGION DURING WED. BOUNDARY LAYER TEMPS MAY
BECOME QUITE CHILLY TUE NT/WED AM IF ENOUGH BREAKS IN THE CLOUDS
CAN DEVELOP...WITH WIDESPREAD LOW TEMPS IN THE 30S. ON
WED...DEPENDING ON THE TIMING OF SHOWER DEVELOPMENT...MAX TEMPS
COULD BRIEFLY REACH THE UPPER 50S TO LOWER 60S IN VALLEYS...BEFORE
FALLING ONCE SHOWERS OCCUR. FOR HIGHER ELEVATIONS...ONLY 40S ARE
EXPECTED. IN FACT...SOME WET SNOW AND/OR GRAUPEL COULD OCCUR
ACROSS THE SOUTHERN ADIRONDACKS AND HIGHER ELEVATIONS ACROSS THE
CATSKILLS AND WESTERN NEW ENGLAND BY LATE WED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
BELOW NORMAL TEMPERATURES AND INTERVALS OF SHOWERS AND SNOW SHOWERS
AS LARGE UPPER LOW AND ASSOCIATED EASTERN NORTH AMERICAN UPPER
TROUGHING CONTROLS THE WEATHER. THERE IS A GOOD CONSENSUS ON THE
LARGE SCALE UPPER LOW AND UPPER TROUGH BUT DISAGREEMENT ON THE TRACK
AND TIMING OF SMALL PIECES OF UPPER ENERGY ROTATING AROUND THE
PERIPHERY OF THE UPPER LOW...SOME OF WHICH ARE EXPECTED TO TRACK
THROUGH OR NEAR OUR REGION. SINCE THE CENTER OF THE UPPER LOW IS
EXPECTED TO TRACK NORTH OF THE REGION...OR ACROSS OUR NORTHERN
PORTION OF THE FORECAST AREA...THE DEEP FLOW ACROSS OUR REGION
SHOULD BE WEST...WHICH TYPICALLY RESULTS ISOLATED TO SCATTERED
COVERAGE OF SHOWERS AND SNOW SHOWERS. THE BEST COVERAGE ALSO IS
TYPICALLY IN LEE OF LAKE ONTARIO INTO THE SOUTHERN ADIRONDACKS AND
WESTERN MOHAWK VALLEY...AND ALSO INTO THE SOUTHERN GREEN MOUNTAINS
TO NORTHERN TACONICS DUE TO SOME UPSLOPE...BUT AGAIN JUST
SCATTERED.
DAYTIME PRECIPITATION TYPE LOOKS TO BE JUST RAIN SHOWERS...BUT
NIGHTTIME COULD SEE SOME SNOW SHOWER ACTIVITY...ESPECIALLY IN HIGHER
ELEVATIONS. THERE ARE ALSO HINTS AT SOME UPPER ENERGY POSSIBLY
INTERACTING WITH THE SOUTHERN STREAM NEXT WEEKEND THAT COULD SUPPORT
MORE ORGANIZED LOW PRESSURE AND MORE ORGANIZED PRECIPITATION...WITH
COLDER THAN NORMAL TEMPERATURES IN PLACE...WILL JUST WATCH
CAREFULLY.
NOT GETTING TO SPECIFIC ON TIMING OF INTERVALS OF SHOWERS/SNOW
SHOWERS DUE TO THE INCONSISTENCIES IN THE FINE DETAILS IN SOURCES OF
GUIDANCE...BUT THERE WILL BE PERIODS OF DRY WEATHER EVEN WITH THE
DOMINANCE OF ISOLATED TO SCATTERED SHOWERS/SNOW SHOWERS IN THE
FORECAST. THERE WILL ALSO BE SOME INTERVALS OF BREAKS IN THE CLOUDS
AND AGAIN...TRYING TO BROADBRUSH TIMING OF ANY CLOUDINESS VERSUS
BREAKS IN THE CLOUDS. HIGHS THURSDAY THROUGH SUNDAY LOOK TO BE IN
THE LOWER TO MID 50S...BUT 40S HIGHER ELEVATIONS...AND MAYBE BARELY
40 IN SOME PARTS OF THE SOUTHERN ADIRONDACKS. LOWS IN THE 20S AND
30S AT NIGHT WITH COLDEST TEMPERATURES IN HIGHER ELEVATIONS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
A LOW PRESSURE SYSTEM WILL CONTINUE TO MOVE INTO SOUTHERN ONTARIO
THIS AFTERNOON INTO TONIGHT. AN OCCLUDED FRONT WILL CONTINUE
PERIODS OF RAIN TONIGHT INTO TOMORROW MORNING.
FLIGHT CONDITIONS ARE GENERALLY LOW VFR/MVFR FOR THE E-CNTRL NY
AND WRN NEW ENGLAND TERMINALS. THERE HAVE BEEN SOME REDUCTIONS TO
IFR LEVELS AT KPOU IN TERMS OF VSBYS. THERE TREND WILL BE FOR THE
CIGS AND VSBYS TO LOWER TO MVFR/IFR LEVELS FOR KPOU/KPSF/KALB/KGFL
WITH THE FIRST BATCH OF RAIN MOVING THROUGH. THE BEST CHC OF IFR
CIGS/VSBYS BTWN 21Z-00Z WILL BE AT KPOU/KPSF.
A BRIEF LULL IN THE PCPN WILL LIKELY OCCUR BTWN 21Z-01Z WITH JUST
SOME DRIZZLE OR VERY LIGHT AROUND. ANOTHER DISTURBANCE AHEAD AN
OCCLUDED FRONTAL BOUNDARY WILL INCREASE THE THREAT OF WIDESPREAD
RAINFALL WITH SOME EMBEDDED RUMBLES OF THUNDER BTWN 01Z-04Z.
EXPECT WIDESPREAD LOW MVFR/IFR CONDITIONS. THE QUESTION WILL BE
HOW QUICKLY THE RAIN MOVES THROUGH...AND IT TRANSITIONS TO PERIODS
OF LIGHT RAIN AND DRIZZLE. DUE TO THE LOW STRATUS/RAIN AND DRIZZLE
IFR CIGS/VSBYS WERE FORECASTED PRIMARILY BTWN 06Z-14Z/TUE.
SLOW IMPROVEMENT IS EXPECTED TO LOW MVFR CONDITIONS BTWN 14Z-
16Z/TUE IN THE WAKE OF THE OCCLUDED FRONT.
LLWS GROUPS WERE KEPT IN UNTIL 21Z/MON AT KGFL/KPOU. THE BEST
LOW-LEVEL JET IS LIFTING NORTH AND EAST OF THE REGION. THE 2FT AGL
WINDS CONTINUE TO BE 30-35 KTS A FEW MORE HOURS.
THE E/SE WINDS CONTINUE AT 8-15 KFT AT KALB/KPSF...WITH SOME GUSTS
IN THE 20-25 KT RANGE. THE WINDS WILL GENERALLY BE FROM THE NE TO
SE AT 5-10 KTS AFTER 21Z...AND THE BE VARIABLE IN DIRECTION FROM
THE TO SOUTH TO SOUTHWEST AT 7 KTS OR LESS OVERNIGHT. THE WINDS
WILL INCREASE FROM THE W TO NW AT 8-12 KTS LATE TOMORROW MORNING
IN THE WAKE OF THE OCCLUDED FRONT.
OUTLOOK...
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
THURSDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY TO SATURDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
&&
.FIRE WEATHER...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THE AREA TODAY AND
TONIGHT...WITH RAINFALL AMTS OF 0.75-1.5 INCHES EXPECTED. THE
WEATHER WILL BE COOL AND UNSETTLED FOR MUCH OF THE WEEK.
&&
.HYDROLOGY...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THE AREA TODAY AND
TONIGHT. EXPECTING WIDESPREAD QPF AMOUNTS OF AROUND AN INCH WITH
HIGHER AMOUNTS UP TO AROUND 1.5 INCHES WHERE THE RAINFALL IS
ENHANCED BY THE STRONG EAST TO SOUTHEAST FLOW...PARTICULARLY
ACROSS THE CENTRAL AND SOUTHEASTERN CATSKILLS...TACONICS...BERKSHIRES
INTO THE LITCHFIELD HILLS AND ACROSS SOUTHERN VERMONT. LOCALIZED
HIGHER AMOUNTS OF 2 TO 3 INCHES WILL BE POSSIBLE.
THERE IS STILL SOME SNOW COVER LEFT IN THE FORECAST AREA. BASED
ON NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER (NOHRSC)
THIS IS ACROSS THE PORTIONS OF THE WESTERN ADIRONDACKS AND ACROSS
THE HIGHER TERRAIN OF THE SOUTHERN GREEN MOUNTAINS.
BASED ON CURRENT FORECASTS...ONLY THE WEST CANADA CREEK AT
HINCKLEY DAM IS EXPECTED TO EXCEED ITS FLOOD STAGE BY TUESDAY
EVENING.
THE REST OF THE WEEK THE FORECAST WILL BE DOMINATED BY A PERSISTENT
UPPER LEVEL TROUGH WHICH WILL RESULT IN COOL TEMPERATURES...BREEZY
CONDITIONS AND OCCASIONAL CHANCES FOR MAINLY LIGHT PRECIPITATION.
FOR DETAILS ON SPECIFIC AREA RIVER AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB-
SITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NYZ054-061.
MA...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR MAZ001-025.
VT...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR VTZ013-014.
&&
$$
SYNOPSIS...IAA/KL/WASULA
NEAR TERM...KL/11/WASULA
SHORT TERM...KL
LONG TERM...NAS
AVIATION...WASULA
FIRE WEATHER...IAA/KL
HYDROLOGY...IAA/KL
AREA FORECAST DISCUSSION
NWS ALBANY NY
1232 PM EDT MON APR 20 2015
.SYNOPSIS...
OCCASIONAL PERIODS OF RAIN ARE EXPECTED ACROSS EASTERN
NEW YORK AND WESTERN NEW ENGLAND THIS AFTERNOON INTO TONIGHT...AS A
LOW PRESSURE SYSTEM TRACKS INTO THE GREAT LAKES...AND A
FRONTAL SYSTEM ASSOCIATED WITH THE LOW APPROACHES FROM THE WEST.
EAST TO SOUTHEAST WINDS WILL BECOME STRONG AND GUSTY TODAY AHEAD OF
THE SYSTEM. A FEW RUMBLES OF THUNDER WILL BE POSSIBLE TONIGHT AS THE
FRONT PASSES. SOME BREAKS IN THE CLOUDS WILL DEVELOP TUESDAY
AFTERNOON BEHIND THE FRONT...OTHERWISE GENERALLY COOL AND SOMEWHAT
UNSETTLED CONDITIONS WILL PERSIST THROUGH THE REMAINDER OF THE WEEK
AS A LARGE UPPER LEVEL LOW REMAINS ANCHORED NORTH OF THE GREAT
LAKES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1230 PM EDT...THE SURGE OF WARM ADVECTION PRECIPITATION
AHEAD OF THE WARM OVER THE UPPER MID ATLANTIC REGION IS MOVING
ACROSS THE SOUTHEAST PORTION OF THE FA WITH SCATTERED SHOWERS
ACROSS THE REMAINDER OF THE FA. ONGOING FORECAST IS IN PRETTY
GOOD SHAPE WITH JUST SOME RETOOLING OF THE POPS...AND HOURLY TEMPS
BASED ON THE RADAR AND OBSERVATIONS TRENDS. THERE IS GOOD SUPPORT
FROM THE LATEST HRRR FOR THE PCPN TO EXPAND NORTHWARD INTO THE
CAPITAL REGION...NRN CATSKILLS...MOHAWK VALLEY...SRN VT CORRIDOR.
SOME DOWNSLOPING DUE TO THE STRONG E/SE LLJ MAY LIMIT THE MODERATE
RAINFALL EXPANSION INTO THE UPPER HUDSON REGION...AND WEST OF THE
SRN GREENS. THE HIGHER TOTALS OF A THIRD TO TWO THIRDS OF AN INCH
OF RAINFALL ARE EXPECTED AND EAST OF THE CAPITAL REGION.
THE STEADIER RAIN SHOULD TAPER TO SHOWERS AND SOME DRIZZLE FOR
THIS AFTERNOON AS THE LOW LEVEL JET AND STRONGEST ISENTROPIC LIFT
PASS NORTH AND EAST OF THE REGION. SOUTH/EAST FACING HIGHER
ELEVATIONS WILL BE MOST PRONE TO MORE PERSISTENT SHOWERS AND
DRIZZLE THIS AFTERNOON.
GUSTY EAST/SOUTHEAST WINDS HAVE DEVELOPED LATE THIS MORNING AS
THE LOW LEVEL JET AND TIGHT PRESSURE GRADIENT PASS THROUGH. SOME
GUSTS OF 30-40 MPH HAVE BEEN NOTED AT KDDH AND KAQW. THE BEST
CHANCE FOR STRONGER WINDS TO MIX DOWN WILL BE ACROSS HIGHER
TERRAIN OF THE TACONICS...SOUTHERN GREEN MTNS...AND
BERKSHIRES...WHERE SOME GUSTS OF 50-55 MPH MAY OCCUR...ESP FROM
THE LATE MORNING THROUGH EARLY AFTERNOON. WIND GUSTS OF 35-45 MPH
WILL ALSO BE LIKELY ACROSS PORTIONS OF THE WESTERN
ADIRONDACKS...MOHAWK VALLEY AND EASTERN CATSKILLS. IN MOST VALLEY
AREAS...SOME WIND GUSTS OF 25-35 MPH COULD OCCUR EARLY THIS
MORNING AS THE RAIN INITIALLY REACHES THE GROUND. HOWEVER...THE
BOUNDARY LAYER SHOULD THEN STABILIZE ONCE WET BULB COOLING
OCCURS INTO THE AFTERNOON...DIMINISHING THE THREAT OF STRONGER
WINDS MIXING DOWN TO THE VALLEY FLOOR.
TEMPS WILL MAINLY BE IN THE 40S TO ABOUT 50F OVER THE HIGHER
TERRAIN...AND LOWER TO MID 50S IN THE VALLEY AREAS...EXCEPT IN THE
UPPER HUDSON REGION/LAKE GEORGE REGION AND PARTS OF SRN VT WHERE
SOME OF THE MAX TEMPS MAY ONLY REACH THE UPPER 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...A WARM FRONT WILL SLOWLY ATTEMPT TO LIFT NORTHWARD FROM
THE MID ATLANTIC STATES...AS A COLD/OCCLUDED FRONT APPROACHES FROM
THE GREAT LAKES REGION. ALTHOUGH THE PARENT LOW IS EXPECTED TO
TRACK ACROSS THE GREAT LAKES REGION TONIGHT...A WEAK TRIPLE POINT
LOW MAY FORM ALONG THE JUNCTION OF THE RETREATING WARM FRONT...AND
APPROACHING COLD FRONT FROM THE WEST...SOMEWHERE OVER SOUTH
CENTRAL PA. MODELS SUGGEST THAT SOME ELEVATED INSTABILITY...WITH
SHOWALTER INDICES DIPPING INTO THE -1C TO -3C RANGE OVERSPREADS AT
LEAST THE WESTERN AND SOUTHERN HALF OF THE REGION
OVERNIGHT...WHICH...IN COMBINATION WITH SYNOPTIC LIFT AHEAD OF THE
APPROACHING FRONTS...AND SOME QG FORCING AHEAD OF AN VORT LOBE
APPROACHING FROM THE SOUTHWEST...MAY ALLOW FOR A ROUND OF ELEVATED
CONVECTION LATER THIS EVENING AND OVERNIGHT...ESP FOR AREAS NEAR
AND SOUTH OF INTERSTATE 90. SO...SOME RUMBLES OF THUNDER ARE NOT
OUT OF THE QUESTION. ANY THUNDERSTORMS ARE EXPECTED TO REMAIN
NON-SEVERE ACROSS OUR REGION...WHICH IS IN AGREEMENT WITH LATEST
SPC DAY 1 OUTLOOK...WHICH KEEPS OUR AREA IN THE GENERAL THUNDER
REGION. HOWEVER...ANY THUNDERSTORMS THAT OCCUR OVERNIGHT COULD
HAVE LOCALLY HEAVY DOWNPOURS. TEMPS ARE EXPECTED TO HOLD NEARLY
STEADY MOST OF THE NIGHT...BEFORE FALLING INTO THE 40S CLOSER TO
DAYBREAK.
TUESDAY...SOME LINGERING SHOWERS WILL BE POSSIBLE IN THE MORNING
AS THE AFOREMENTIONED VORT LOBE SWINGS ACROSS. THEN...IT APPEARS
THAT OUR REGION WILL EXPERIENCE A PERIOD OF SUBSIDENCE IN THE
AFTERNOON HOURS...WHEN SOME BREAKS OF SUN COULD OCCUR. SOME LOW
LEVEL INSTABILITY COULD ALLOW FOR ISOLATED SHOWERS TO DEVELOP
LATER IN THE AFTERNOON...MAINLY ACROSS THE WESTERN ADIRONDACK
REGION. MAX TEMPS ARE FORECAST TO REACH THE LOWER/MID 60S IN
VALLEY AREAS AND 50S ACROSS HIGHER ELEVATIONS.
TUE NT-WED...ANOTHER REINFORCING COLD FRONT AND UPPER LEVEL
SHORTWAVE ARE EXPECTED TO CROSS THE REGION ON WED. WEAK RIDGING
JUST AHEAD OF THIS FEATURE MAY ALLOW FOR SOME BREAKS IN THE CLOUDS
TO CONTINUE INTO EARLY TUE NT...BEFORE CLOUDS REDEVELOP...AND
SHOWERS OVERSPREAD THE REGION DURING WED. BOUNDARY LAYER TEMPS MAY
BECOME QUITE CHILLY TUE NT/WED AM IF ENOUGH BREAKS IN THE CLOUDS
CAN DEVELOP...WITH WIDESPREAD LOW TEMPS IN THE 30S. ON
WED...DEPENDING ON THE TIMING OF SHOWER DEVELOPMENT...MAX TEMPS
COULD BRIEFLY REACH THE UPPER 50S TO LOWER 60S IN VALLEYS...BEFORE
FALLING ONCE SHOWERS OCCUR. FOR HIGHER ELEVATIONS...ONLY 40S ARE
EXPECTED. IN FACT...SOME WET SNOW AND/OR GRAUPEL COULD OCCUR
ACROSS THE SOUTHERN ADIRONDACKS AND HIGHER ELEVATIONS ACROSS THE
CATSKILLS AND WESTERN NEW ENGLAND BY LATE WED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
BELOW NORMAL TEMPERATURES AND INTERVALS OF SHOWERS AND SNOW SHOWERS
AS LARGE UPPER LOW AND ASSOCIATED EASTERN NORTH AMERICAN UPPER
TROUGHING CONTROLS THE WEATHER. THERE IS A GOOD CONSENSUS ON THE
LARGE SCALE UPPER LOW AND UPPER TROUGH BUT DISAGREEMENT ON THE TRACK
AND TIMING OF SMALL PIECES OF UPPER ENERGY ROTATING AROUND THE
PERIPHERY OF THE UPPER LOW...SOME OF WHICH ARE EXPECTED TO TRACK
THROUGH OR NEAR OUR REGION. SINCE THE CENTER OF THE UPPER LOW IS
EXPECTED TO TRACK NORTH OF THE REGION...OR ACROSS OUR NORTHERN
PORTION OF THE FORECAST AREA...THE DEEP FLOW ACROSS OUR REGION
SHOULD BE WEST...WHICH TYPICALLY RESULTS ISOLATED TO SCATTERED
COVERAGE OF SHOWERS AND SNOW SHOWERS. THE BEST COVERAGE ALSO IS
TYPICALLY IN LEE OF LAKE ONTARIO INTO THE SOUTHERN ADIRONDACKS AND
WESTERN MOHAWK VALLEY...AND ALSO INTO THE SOUTHERN GREEN MOUNTAINS
TO NORTHERN TACONICS DUE TO SOME UPSLOPE...BUT AGAIN JUST
SCATTERED.
DAYTIME PRECIPITATION TYPE LOOKS TO BE JUST RAIN SHOWERS...BUT
NIGHTTIME COULD SEE SOME SNOW SHOWER ACTIVITY...ESPECIALLY IN HIGHER
ELEVATIONS. THERE ARE ALSO HINTS AT SOME UPPER ENERGY POSSIBLY
INTERACTING WITH THE SOUTHERN STREAM NEXT WEEKEND THAT COULD SUPPORT
MORE ORGANIZED LOW PRESSURE AND MORE ORGANIZED PRECIPITATION...WITH
COLDER THAN NORMAL TEMPERATURES IN PLACE...WILL JUST WATCH
CAREFULLY.
NOT GETTING TO SPECIFIC ON TIMING OF INTERVALS OF SHOWERS/SNOW
SHOWERS DUE TO THE INCONSISTENCIES IN THE FINE DETAILS IN SOURCES OF
GUIDANCE...BUT THERE WILL BE PERIODS OF DRY WEATHER EVEN WITH THE
DOMINANCE OF ISOLATED TO SCATTERED SHOWERS/SNOW SHOWERS IN THE
FORECAST. THERE WILL ALSO BE SOME INTERVALS OF BREAKS IN THE CLOUDS
AND AGAIN...TRYING TO BROADBRUSH TIMING OF ANY CLOUDINESS VERSUS
BREAKS IN THE CLOUDS. HIGHS THURSDAY THROUGH SUNDAY LOOK TO BE IN
THE LOWER TO MID 50S...BUT 40S HIGHER ELEVATIONS...AND MAYBE BARELY
40 IN SOME PARTS OF THE SOUTHERN ADIRONDACKS. LOWS IN THE 20S AND
30S AT NIGHT WITH COLDEST TEMPERATURES IN HIGHER ELEVATIONS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AN APPROACHING WARM FRONT AND A LOW PRESSURE SYSTEM WILL BRING A
WIDESPREAD SOAKING RAINFALL TO THE REGION FROM THIS MORNING
THROUGH TONIGHT.
VFR/LOW MVFR CONDITIONS SHOULD PERSIST THROUGH THE LATE
MORNING...AS RAIN HAS BEEN LIGHT AND THE ATMOSPHERE IS STILL
TAKING SOME TIME TO MOISTEN. CIGS WILL GRADUALLY LOWER...BUT
SHOULD REMAIN VFR THROUGH 14Z-16Z THIS MORNING. OCCASIONAL LIGHT
TO MODERATE RAIN SHOULD PREVAIL AFTER 14Z-16Z. RAIN INTENSITY
SHOULD WEAKEN BY MID TO LATE AFTERNOON BUT OCCASIONAL LIGHT RAIN
IS EXPECTED TO CONTINUE. CONDITIONS WILL GENERALLY DETERIORATE TO
MVFR ALTHOUGH SOME BRIEF IFR IS POSSIBLE BEFORE 00Z TUESDAY. AFTER
00Z... CEILINGS WILL CONTINUE TO LOWER TOWARD IFR BUT ENOUGH
UNCERTAINTY TO JUST INDICATE SCATTERED LAYER BELOW 1000 FEET WITH
CEILINGS AROUND 1000 FEET BETWEEN 00Z-12Z. VISIBILITIES WILL
CONTINUE MVFR WITH PERIODS OF LIGHT RAIN THROUGH THIS EVENING.
LOW LEVEL WIND SHEAR /LLWS/ IS EXPECTED AT KPSF/KPOU AND KGFL
THROUGH THE DAY AND WAS BEGUN AT 12Z...AS A STRONG SOUTHEAST JET
ALOFT MOVES OVERHEAD. SURFACE WINDS SHOULD BE STRONGER AND
OCCASIONALLY GUSTY AT KALB...SO WILL LEAVE OUT MENTION OF LLWS FOR
NOW. LLWS SHOULD END BY 00Z AS THE LOW LEVEL JET SEGMENT EXITS THE
REGION.
SURFACE WINDS WILL BE EAST-SOUTHEAST AROUND 10-16 KT BY THE LATE
MORNING. GUSTS COULD EXCEED 20-25 KT... ESPECIALLY AT KALB/KPSF.
WINDS REMAIN EAST TO SOUTHEAST THIS EVENING BUT DIMINISH TO 10 KT
OR LESS. WINDS WILL SHIFT TO SOUTHWEST AT 6 KT OR LESS LATER
TONIGHT.
OUTLOOK...
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
THURSDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
&&
.FIRE WEATHER...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THE AREA TODAY AND
TONIGHT...WITH RAINFALL AMTS OF 0.75-1.5 INCHES EXPECTED. THE
WEATHER WILL BE COOL AND UNSETTLED FOR MUCH OF THE WEEK.
&&
.HYDROLOGY...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THE AREA TODAY AND
TONIGHT. EXPECTING WIDESPREAD QPF AMOUNTS OF AROUND AN INCH WITH
HIGHER AMOUNTS UP TO AROUND 1.5 INCHES WHERE THE RAINFALL IS
ENHANCED BY THE STRONG EAST TO SOUTHEAST FLOW...PARTICULARLY
ACROSS THE CENTRAL AND SOUTHEASTERN CATSKILLS...TACONICS...BERKSHIRES
INTO THE LITCHFIELD HILLS AND ACROSS SOUTHERN VERMONT. LOCALIZED
HIGHER AMOUNTS OF 2 TO 3 INCHES WILL BE POSSIBLE.
THERE IS STILL SOME SNOW COVER LEFT IN THE FORECAST AREA. BASED
ON NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER (NOHRSC)
THIS IS ACROSS THE PORTIONS OF THE WESTERN ADIRONDACKS AND ACROSS
THE HIGHER TERRAIN OF THE SOUTHERN GREEN MOUNTAINS.
BASED ON CURRENT FORECASTS...ONLY THE WEST CANADA CREEK AT
HINCKLEY DAM IS EXPECTED TO EXCEED ITS FLOOD STAGE BY TUESDAY
EVENING.
THE REST OF THE WEEK THE FORECAST WILL BE DOMINATED BY A PERSISTENT
UPPER LEVEL TROUGH WHICH WILL RESULT IN COOL TEMPERATURES...BREEZY
CONDITIONS AND OCCASIONAL CHANCES FOR MAINLY LIGHT PRECIPITATION.
FOR DETAILS ON SPECIFIC AREA RIVER AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB-
SITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NYZ054-061.
MA...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR MAZ001-025.
VT...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR VTZ013-014.
&&
$$
SYNOPSIS...IAA/KL/WASULA
NEAR TERM...KL/11/WASULA
SHORT TERM...KL
LONG TERM...NAS
AVIATION...NAS/JPV
FIRE WEATHER...IAA/KL
HYDROLOGY...IAA/KL
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
641 PM EDT MON APR 20 2015
.SYNOPSIS...
A WARM FRONT JUST NORTHWEST OF INTERSTATE 95 WILL MERGE WITH AN
EASTWARD MOVING COLD FRONT AND PUSH OUT TO SEA BY MORNING. SEVERAL
REINFORCING COLD FRONTS WILL MOVE SOUTHEAST THROUGH THE MID ATLANTIC
STATES TUESDAY, WEDNESDAY AND THURSDAY AFTERNOONS. LOW PRESSURE
WILL CROSS TO THE SOUTH OF THE AREA SATURDAY INTO SATURDAY NIGHT.
HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE WEST THROUGH THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
630 PM ESTF: NOT MUCH CHANGE FROM THE 455 PM ESTF. THE HRRR CONTINUES
THE DEVELOPMENT SO WE HOLD ONTO THAT FOR NOW AND THE 12Z SPCWRF IS
NOT TOO BAD, THOUGH IT APPEARS A TOUCH FAST.
KRDG HAD 38 KT AT 2227Z. VERY GOOD FOR A SMALL STORM WITH ELEVATED
ROATION AND PREVIOUS NORTHERLY FLOW.
QSTNRY FRONT JUST NW OF I95. STRONGEST STORMS ANTICIPATED ALONG
OR EAST OF THAT LATE THIS EVENING.
SPC CONTINUES THE TORNADO WATCH FOR THE WRN/SWRN PARTS OF THE REGION
UNTIL 10 PM. MORE SHOWERS AND SCT TSTMS WITH FROPA AROUND MIDNIGHT
WEST -- 03 AM EAST. WINDS SHIFT WRLY BEHIND THE FRNT AND PRECIP
ENDS MOST AREAS BY DAWN.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
DEEP LOW PRESSURE REMAIN ACROSS CANADA WHILE HIGH PRESSURE BUILDS
OVER THE SE STATES. RATHER STRONG PRESSURE GRADIENT WILL CREATE
MODERATE/GUSTY WINDS TUE. MOSTLY FAIR WEATHER IS EXPECTED.
TEMPERATURES WILL BE SEASONABLY COOL WITH HIGHS IN THE LOW/MID 60S
MOST AREAS. WEST WINDS 10 TO 15 MPH WITH GUSTS UP TO 20 MPH DURING
THE AFTERNOON.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
A PERSISTENT UPPER LEVEL TROUGH WILL SPIN OVER THE GREAT LAKES AREA
WITH A GRADUAL PUSH TO EAST THROUGH THE WEEK, SETTLING OVER EXTREME
NORTHEASTERN UNITED STATES AND SPINNING ACROSS EASTERN CANADA
THROUGH THE WEEKEND. SEVERAL SHORTWAVES EMBEDDED IN THE UPPER LEVEL
FLOW WILL ROTATE THROUGH OUR AREA AND WE WILL SEE SHOWERS CROSS
PARTS OF THE REGION THROUGH THE WEEK.
A COLD FRONT WILL PUSH DOWN THROUGH THE REGION WEDNESDAY INTO
WEDNESDAY NIGHT, WITH A CHANCE FOR SOME SHOWERS ACROSS THE AREA.
COLDER AIR LOCATED ALONG AND BEHIND THE FRONT MAY ALLOW FOR SOME
SNOW FLAKES TO FALL ACROSS THE HIGHER TERRAIN OF THE SOUTHERN
POCONOS.
A SECOND COLD FRONT IS FORECAST TO ARRIVE BY THURSDAY EVENING BUT IT
APPEARS TO LACK MUCH MOISTURE. THEREFORE, ONLY A FEW LIGHT SHOWERS
ACROSS THE NORTHWESTERN AREAS MAY OCCUR AS THE MOISTURE LESSENS AS
IT PUSHES THROUGH THE REGION.
THE UPPER LOW FINALLY MOVES EASTWARD BUT THE CYCLONIC FLOW WILL
REMAIN ACROSS THE REGION INTO THE WEEKEND WITH A CHANCE FOR SHOWERS
CONTINUING.
THE MODELS ARE SHOWING THAT A LOW PRESSURE SYSTEM WILL CROSS TO THE
SOUTH OF THE REGION DURING THE WEEKEND. JUST HOW FAR NORTH THE
SYSTEM GETS WILL DICTATE WHETHER OR NOT WE SEE SHOWERS PUSH
NORTHWARD INTO OUR SOUTHERN AREAS. WE HAVE INCLUDED JUST A SLIGHT
CHANCE FOR SOME SHOWERS FOR SATURDAY AND SATURDAY NIGHT ACROSS THE
SOUTHERN PORTION OF THE FORECAST AREA.
HIGH PRESSURE WILL THEN BUILD IN FROM THE WEST FOR SUNDAY AND MONDAY
WITH A DRY PERIOD EXPECTED ACROSS OUR REGION.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY, AND SURROUNDING AREAS.
THROUGH TONIGHT...TAFS HAVE UPDATED WITH SOME TIMING OF POTENTIALLY
STRONGER TSTMS AND GUSTY WINDS PER HRRR. FIRST STORM VCNTY KRDG
HAD A WEST GUST 38 KT AT 2227Z.
IFR CIGS NW OF THE QSTRY FRONT, ESPECIALLY KABE. ELSEWHERE, VFR
CIGS WITH A PERIOD OF IFR CONDS IN SHOWERS AND TSTMS TONIGHT.
LIGHT WINDS, MOSTLY NE-SE NW OF THE QSTRY FNT AND SOUTHERLY
GUSTING TO 15 KT SOUTH OF THE FRONT. ALL WINDS TURNING WNW
OVERNIGHT POST LATE NIGHT CFP.
TUE...VFR SCT-BKN AOA 4500 FT WITH GUSTY W WINDS 20-25 KT.
OUTLOOK...
TUESDAY NIGHT...MAINLY VFR CONDITIONS EXPECTED.
WEDNESDAY...MAINLY VFR CONDITIONS EXPECTED WITH SUB-VFR SHOWERS
POSSIBLE AS A COLD FRONT CROSSES THE REGION.
THURSDAY THROUGH SATURDAY...MAINLY VFR CONDITIONS EXPECTED.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE ACROSS THE OCEAN AREAS THE REST OF
TODAY...TONIGHT AND INTO TUESDAY. SCA FOR SEAS INTO TONIGHT AND
THEN WINDS AND SEAS TUE. SCT TSTMS TONIGHT AND THEN FAIR WEATHER
TUE. AREAS OF FOG INTO TONIGHT.
SUB-SCA CONDITIONS ACROSS DEL BAY ATTM WITH PROBABLE HIGHER WAVES
ACROSS THE MOUTH OF THE BAY AND POSSIBLY SOME HIGHER SEAS UP ACROSS
THE SRN PART OF THE BAY. WE WILL KEEP THE SCA FLAG FOR AWHILE INTO
THE EVENING BUT DROP IT ACROSS NRN DEL BAY. IT MAY NEED TO BE ISSUED
THERE AGAIN FOR WINDS G25 FOR TUESDAY. SCT TSTMS TONIGHT BUT FAIR
WEATHER FOR TUE.
OUTLOOK...
WEDNESDAY...SEAS WILL INCREASE AND NEAR 5 FEET DURING THE
AFTERNOON BUT SHOULD SUBSIDE FAIRLY QUICKLY. WINDS WILL GUST
AROUND 20 KNOTS. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR A TIME
ON WEDNESDAY.
THURSDAY...SUB- ADVISORY CONDITIONS ARE EXPECTED ON THE AREA
WATERS.
FRIDAY...WINDS WILL BE GUSTY OUT OF THE NORTHWEST AND A SMALL
CRAFT ADVISORY MAY BE NEEDED.
SATURDAY...SUB- ADVISORY CONDITIONS ARE EXPECTED ON THE AREA
WATERS.
&&
.EQUIPMENT...
WILL TRY TO RESTORE PHL NWR SHORTLY. ITS OUTAGE SINCE ABOUT 557P.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ431-450>455.
&&
$$
SYNOPSIS...MEOLA
NEAR TERM...DRAG/O`HARA 641 PM
SHORT TERM...O`HARA
LONG TERM...MEOLA
AVIATION...DRAG/MEOLA/O`HARA 641PM
MARINE...DRAG/MEOLA/O`HARA
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
629 PM EDT MON APR 20 2015
.SYNOPSIS...
A WARM FRONT JUST NORTHWEST OF INTERSTATE 95 WILL MERGE WITH AN
EASTWARD MOVING COLD FRONT AND PUSH OUT TO SEA BY MORNING. SEVERAL
REINFORCING COLD FRONTS WILL MOVE SOUTHEAST THROUGH THE MID ATLANTIC
STATES TUESDAY, WEDNESDAY AND THURSDAY AFTERNOONS. LOW PRESSURE
WILL CROSS TO THE SOUTH OF THE AREA SATURDAY INTO SATURDAY NIGHT.
HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE WEST THROUGH THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
630 PM ESTF: NOT MUCH CHANGE FROM THE 455 PM ESTF...THOUGH
CONFIDENCE ON STRONG TSTMS IS A LITTLE LESS THAN WHAT I`D LIKE,
BASED ON DEVELOPMENTS THROUGH 6 PM. THE HRRR CONTINUES THE
DEVELOPMENT SO WE HOLD ONTO THAT FOR NOW AND THE 12Z SPCWRF IS
NOT TOO BAD, THOUGH IT APPEARS A TOUCH FAST.
QSTNRY FRONT JUST NW OF I95. STRONGEST STORMS ANTICIPATED ALONG
OR EAST OF THAT LATE THIS EVENING.
SPC CONTINUES THE TORNADO WATCH FOR THE WRN/SWRN PARTS OF THE REGION
UNTIL 10 PM. MORE SHOWERS AND SCT TSTMS WITH FROPA AROUND MIDNIGHT
WEST -- 03 AM EAST. WINDS SHIFT WRLY BEHIND THE FRNT AND PRECIP
ENDS MOST AREAS BY DAWN.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
DEEP LOW PRESSURE REMAIN ACROSS CANADA WHILE HIGH PRESSURE BUILDS
OVER THE SE STATES. RATHER STRONG PRESSURE GRADIENT WILL CREATE
MODERATE/GUSTY WINDS TUE. MOSTLY FAIR WEATHER IS EXPECTED.
TEMPERATURES WILL BE SEASONABLY COOL WITH HIGHS IN THE LOW/MID 60S
MOST AREAS. WEST WINDS 10 TO 15 MPH WITH GUSTS UP TO 20 MPH DURING
THE AFTERNOON.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
A PERSISTENT UPPER LEVEL TROUGH WILL SPIN OVER THE GREAT LAKES AREA
WITH A GRADUAL PUSH TO EAST THROUGH THE WEEK, SETTLING OVER EXTREME
NORTHEASTERN UNITED STATES AND SPINNING ACROSS EASTERN CANADA
THROUGH THE WEEKEND. SEVERAL SHORTWAVES EMBEDDED IN THE UPPER LEVEL
FLOW WILL ROTATE THROUGH OUR AREA AND WE WILL SEE SHOWERS CROSS
PARTS OF THE REGION THROUGH THE WEEK.
A COLD FRONT WILL PUSH DOWN THROUGH THE REGION WEDNESDAY INTO
WEDNESDAY NIGHT, WITH A CHANCE FOR SOME SHOWERS ACROSS THE AREA.
COLDER AIR LOCATED ALONG AND BEHIND THE FRONT MAY ALLOW FOR SOME
SNOW FLAKES TO FALL ACROSS THE HIGHER TERRAIN OF THE SOUTHERN
POCONOS.
A SECOND COLD FRONT IS FORECAST TO ARRIVE BY THURSDAY EVENING BUT IT
APPEARS TO LACK MUCH MOISTURE. THEREFORE, ONLY A FEW LIGHT SHOWERS
ACROSS THE NORTHWESTERN AREAS MAY OCCUR AS THE MOISTURE LESSENS AS
IT PUSHES THROUGH THE REGION.
THE UPPER LOW FINALLY MOVES EASTWARD BUT THE CYCLONIC FLOW WILL
REMAIN ACROSS THE REGION INTO THE WEEKEND WITH A CHANCE FOR SHOWERS
CONTINUING.
THE MODELS ARE SHOWING THAT A LOW PRESSURE SYSTEM WILL CROSS TO THE
SOUTH OF THE REGION DURING THE WEEKEND. JUST HOW FAR NORTH THE
SYSTEM GETS WILL DICTATE WHETHER OR NOT WE SEE SHOWERS PUSH
NORTHWARD INTO OUR SOUTHERN AREAS. WE HAVE INCLUDED JUST A SLIGHT
CHANCE FOR SOME SHOWERS FOR SATURDAY AND SATURDAY NIGHT ACROSS THE
SOUTHERN PORTION OF THE FORECAST AREA.
HIGH PRESSURE WILL THEN BUILD IN FROM THE WEST FOR SUNDAY AND MONDAY
WITH A DRY PERIOD EXPECTED ACROSS OUR REGION.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY, AND SURROUNDING AREAS.
THROUGH TONIGHT...TAFS HAVE UPDATED WITH SOME TIMING OF POTENTIALLY
STRONGER TSTMS AND GUSTY WINDS PER HRRR. FIRST STORM NOW AT KRDG.
IFR CIGS NW OF THE QSTRY FRONT, ESPECIALLY KABE. ELSEWHERE, VFR
CIGS WITH A PERIOD OF IFR CONDS IN SHOWERS AND TSTMS TONIGHT.
LIGHT WINDS, MOSTLY NE-SE NW OF THE QSTRY FNT AND SOUTHERLY
GUSTING TO 15 KT SOUTH OF THE FRONT. ALL WINDS TURNING WNW
OVERNIGHT POST LATE NIGHT CFP.
TUE...VFR SCT-BKN AOA 4500 FT WITH GUSTY W WINDS 20-25 KT.
OUTLOOK...
TUESDAY NIGHT...MAINLY VFR CONDITIONS EXPECTED.
WEDNESDAY...MAINLY VFR CONDITIONS EXPECTED WITH SUB-VFR SHOWERS
POSSIBLE AS A COLD FRONT CROSSES THE REGION.
THURSDAY THROUGH SATURDAY...MAINLY VFR CONDITIONS EXPECTED.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE ACROSS THE OCEAN AREAS THE REST OF
TODAY...TONIGHT AND INTO TUESDAY. SCA FOR SEAS INTO TONIGHT AND
THEN WINDS AND SEAS TUE. SCT TSTMS TONIGHT AND THEN FAIR WEATHER
TUE. AREAS OF FOG INTO TONIGHT.
SUB-SCA CONDITIONS ACROSS DEL BAY ATTM WITH PROBABLE HIGHER WAVES
ACROSS THE MOUTH OF THE BAY AND POSSIBLY SOME HIGHER SEAS UP ACROSS
THE SRN PART OF THE BAY. WE WILL KEEP THE SCA FLAG FOR AWHILE INTO
THE EVENING BUT DROP IT ACROSS NRN DEL BAY. IT MAY NEED TO BE ISSUED
THERE AGAIN FOR WINDS G25 FOR TUESDAY. SCT TSTMS TONIGHT BUT FAIR
WEATHER FOR TUE.
OUTLOOK...
WEDNESDAY...SEAS WILL INCREASE AND NEAR 5 FEET DURING THE
AFTERNOON BUT SHOULD SUBSIDE FAIRLY QUICKLY. WINDS WILL GUST
AROUND 20 KNOTS. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR A TIME
ON WEDNESDAY.
THURSDAY...SUB- ADVISORY CONDITIONS ARE EXPECTED ON THE AREA
WATERS.
FRIDAY...WINDS WILL BE GUSTY OUT OF THE NORTHWEST AND A SMALL
CRAFT ADVISORY MAY BE NEEDED.
SATURDAY...SUB- ADVISORY CONDITIONS ARE EXPECTED ON THE AREA
WATERS.
&&
.EQUIPMENT...
WILL TRY TO RESTORE PHL NWR SHORTLY. ITS OUTAGE SINCE ABOUT 557P.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ431-450>455.
&&
$$
SYNOPSIS...MEOLA
NEAR TERM...DRAG/O`HARA 630
SHORT TERM...O`HARA
LONG TERM...MEOLA
AVIATION...DRAG/MEOLA/O`HARA 630
MARINE...DRAG/MEOLA/O`HARA
EQUIPMENT...DRAG 630
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1229 PM CDT MON APR 20 2015
.UPDATE...
ISSUED AT 1022 AM CDT MON APR 20 2015
LITTLE CHANGE NEEDED TO THE PREVIOUS FORECAST. SHOWERS HAVE
LARGELY EXITED THE AREA...AND EARLIER CLEARING TREND ACROSS WEST
CENTRAL ILLINOIS HAS BEEN FILLING IN WITH DIURNAL CLOUDS. HIGH-RES
MODEL GUIDANCE SHOWING POTENTIAL FOR SOME LIGHT REDEVELOPMENT
THROUGH THE DAY...WHICH CURRENTLY IS SEEN IN CENTRAL IOWA MOVING
SOUTHEAST. WITH STRONG COLD AIR ADVECTION AND NORTHWEST WINDS
GUSTING 30-40 MPH...HAVE LOWERED AFTERNOON TEMPERATURES BY A
COUPLE DEGREES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT MON APR 20 2015
07Z/2AM WATER VAPOR IMAGERY SHOWS LONG-WAVE TROUGH AXIS EXTENDING
FROM MINNESOTA TO NORTHERN TEXAS, WITH VIGOROUS SHORT-WAVE NOTED ON
ITS EAST SIDE OVER SOUTHEAST MISSOURI. WITH MAIN WAVE STILL TO THE
WEST, SCATTERED SHOWERS ARE ONGOING ACROSS CENTRAL ILLINOIS EARLY
THIS MORNING. AS SOUTHEAST MISSOURI WAVE TRACKS INTO THE OHIO RIVER
VALLEY, THINK AREAL COVERAGE OF SHOWERS WILL DIMINISH AFTER SUNRISE,
WITH LITTLE OR NO PRECIP OCCURRING FOR THE BALANCE OF THE MORNING.
DESPITE LOW-LEVEL DRYING IN THE WAKE OF THIS FEATURE, SYNOPTIC-SCALE
CYCLONIC FLOW ALOFT WILL LEAD TO STEEP LAPSE RATES AND PERHAPS A FEW
SHOWERS FROM LATE MORNING INTO THE AFTERNOON. MOST MODEL GUIDANCE
REMAINS DRY: HOWEVER, BOTH THE HRRR AND 4KM WRF-NMM SUGGEST AT LEAST
ISOLATED SHOWERS AS THE ATMOSPHERE DESTABILIZES. WILL CARRY SLIGHT
CHANCE POPS ACROSS THE BOARD TO COVER THIS POSSIBILITY. COLD FRONT
CURRENTLY APPROACHING THE I-55 CORRIDOR WILL SWEEP EASTWARD THIS
MORNING AND EXIT INTO INDIANA BY MIDDAY. STRONG/GUSTY WINDS WILL
DEVELOP BEHIND THE FRONT AS PRESSURE GRADIENT TIGHTENS. LATEST OBS
ARE ALREADY SHOWING GUSTS IN THE 25 TO 30MPH RANGE AND THINK MIXING
OF HIGHER MOMENTUM AIR ALOFT WILL RESULT IN GUSTS OF 30 TO 35MPH
DURING THE DAY. HIGH TEMPERATURES WILL BE IN THE UPPER 50S AND
LOWER 60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 AM CDT MON APR 20 2015
A COOL AND MOSTLY DRY WEEK IS ON TAP ACROSS CENTRAL ILLINOIS, WITH
THE NEXT SIGNIFICANT CHANCE FOR RAIN LIKELY HOLDING OFF UNTIL NEXT
WEEKEND. A DEEP UPPER LOW OVER THE GREAT LAKES WILL BE THE DOMINANT
WEATHER FEATURE EARLY IN THE PERIOD, KEEPING THE MIDWEST LOCKED IN A
NORTHWESTERLY FLOW PATTERN. THANKS TO A TIGHTENING PRESSURE
GRADIENT AHEAD OF AN APPROACHING COLD FRONT, STRONG WESTERLY WINDS
WILL ONCE AGAIN DEVELOP ON TUESDAY. NUMERIC GUIDANCE AND FORECAST
SOUNDINGS BOTH SUGGEST GUSTS REACHING 30 TO 35MPH AT TIMES. THE
FRONT WILL PASS THROUGH THE AREA TUESDAY NIGHT INTO WEDNESDAY
MORNING: HOWEVER, DEEP-LAYER MOISTURE WILL BE LACKING, SO PRECIP
CHANCES WILL REMAIN NEGLIGIBLE. WILL ONLY CARRY LOW CHANCE POPS
ACROSS THE SOUTHERN KILX CWA AS THE FRONT PASSES. AN EVEN COOLER
AIRMASS WILL ARRIVE FOR THE MIDDLE AND END OF THE WEEK BEHIND THE
DEPARTING FRONT, WITH HIGHS DROPPING INTO THE UPPER 50S/LOWER 60S
FOR WEDNESDAY THROUGH FRIDAY. OVERNIGHT LOWS WILL DIP INTO THE 30S,
WITH THE BEST POTENTIAL FOR FROST LIKELY SETTING UP FOR WEDNESDAY
NIGHT AND THURSDAY NIGHT AS SKIES REMAIN CLEAR AND WINDS DIMINISH.
FURTHER OUT, MAJOR MODEL DISCREPANCIES HAVE DEVELOPED CONCERNING THE
NEXT POTENTIAL SYSTEM FOR THE END OF THE WEEK. THE 00Z APR 20 GFS
HAS MADE A MAJOR SHIFT FROM ITS PREVIOUS RUNS AND NOW SHOWS RAIN
SPREADING INTO CENTRAL ILLINOIS FROM AN APPROACHING UPPER LOW AS
EARLY AS FRIDAY. MEANWHILE, BOTH THE ECMWF AND GEM ARE MUCH SLOWER,
WITH RAIN NOT ARRIVING UNTIL LATE FRIDAY NIGHT INTO SATURDAY. GIVEN
INITIAL PRESENCE OF A STRONG RIDGE AXIS ACROSS THE MIDWEST, THINK
THE RAPID PROGRESSION OF RAIN INTO THE DRY AIRMASS SEEMS SUSPECT.
IN ADDITION, THE SLOWER ECMWF/GEM HAVE MAINTAINED GOOD CONSISTENCY
WITH THEIR EARLIER RUNS. AS A RESULT, HAVE REJECTED THE GFS IN
FAVOR OF THE ECMWF/GEM CONSENSUS FOR THE END OF THE WEEK. HAVE
THEREFORE KEPT FRIDAY DRY, THEN HAVE INTRODUCED POPS MAINLY ACROSS
THE CENTRAL AND SOUTHERN CWA FRIDAY NIGHT INTO SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1229 PM CDT MON APR 20 2015
WEST WINDS WILL REMAIN GUSTY THROUGH THE AFTERNOON WITH SOME
PERIODS OVER 30 KNOTS. WINDS WILL SUBSIDE THIS EVENING...ALTHOUGH
SUSTAINED SPEEDS REMAIN 10 KNOTS OR SO MUCH OF THE NIGHT. SPEEDS
EXPECTED TO PICK UP AGAIN EARLY TUESDAY...WITH THE GFS THE MOST
AGGRESSIVE WITH GUSTS OVER 30 KNOTS AS EARLY AS 15Z. DID NOT GO
QUITE THAT HIGH YET...BUT HAVE INCLUDED GUSTS 25-28 KNOTS AT ALL
SITES TUESDAY MORNING.
SOME LINGERING MVFR CONDITIONS CONTINUING FOR ANOTHER HOUR OR TWO
AT KCMI...BUT GENERAL TREND WILL BE FOR CEILINGS 3500-4500 FEET
ACROSS CENTRAL ILLINOIS THIS AFTERNOON. CLOUDS ARE DIURNAL IN
NATURE AND SHOULD DISSIPATE EARLY EVENING WITH LOSS OF DAYTIME
HEATING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
ISSUED BY NATIONAL WEATHER SERVICE LA CROSSE WI
1230 PM CDT MON APR 20 2015
.SYNOPSIS...
ISSUED AT 335 AM CDT MON APR 20 2015
DEEPENING CYCLONE (987 MB) WAS LOCATED IN EXTREME WESTERN LOWER MI
AND BROUGHT WIDESPREAD RAIN TO THE DVN CWA LAST EVENING AND OVERNIGHT.
A COLD FRONT HAS SWEPT THROUGH THE AREA WITH NORTHWEST WINDS GUSTING
TO 35 MPH. DOPPLER RADAR INDICATED LIGHT RAIN STILL FALLING ROUGHLY
ALONG AND NORTH OF HIGHWAY 30 IN IA AND IL AND WAS GRADUALLY LIFTING
NORTHWARD. CURRENT TEMPERATURES RANGED FROM THE LOWER 40S TO MID 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT MON APR 20 2015
FORECAST FOCUS ON RAIN CHANCES...WIND AND TEMPERATURES.
TODAY...THIS WILL BE A VERY WINDY AND MUCH COOLER DAY AS THE DEEPENING
CYCLONE TRACKS NORTHWARD TO JUST NORTH OF LAKE SUPERIOR. THE STRATIFORM
RAIN SHIELD SHOULD LIFT OUT OF THE DVN CWA BY MID TO LATE MORNING.
OTHERWISE PARTLY SUNNY SKIES ARE EXPECTED WITH FORECAST SOUNDINGS
INDICATING DEEP MIXING TO ABOUT 700 MB BRINGING DOWN 35 TO 40 MPH
WIND GUSTS...WHICH IS BELOW ADVISORY CRITERIA. NONETHELESS HANG ONTO
YOUR HAT AND THE STEERING WHEEL! STEEP LAPSE RATES AND ENOUGH MOISTURE
SHOULD ALLOW FOR ISOLATED HIGH-BASED RAIN SHOWERS ANYWHERE IN THE CWA
LATER THIS MORNING THROUGH THE AFTERNOON. THE HRRR AND WRF MODELS DEPICT
THIS SCENARIO QUITE WELL. TEMPERATURES WILL BE A CHALLENGE AGAIN AS
WE HAVE COLD AIR ADVECTION BUT THERE WILL ALSO BE SOME SUNSHINE TO
OFFSET THIS SOMEWHAT. THEREFORE A GOOD COMPROMISE SEEMS TO BE HIGHS
IN THE UPPER 50S TO LOWER 60S.
TONIGHT...DEEP CYCLONE (980 MB) WILL BE ANCHORED NORTH OF LAKE SUPERIOR
DUE TO A STRONG GREENLAND BLOCK. SKIES SHOULD BE PARTLY CLOUDY AND GUSTY
WEST WINDS WILL DIMINISH BY SUNSET WITH DECOUPLING. HOWEVER... THE WINDS
SHOULD STAY AT 10 TO 15 MPH MUCH OF THE NIGHT. MINIMUM TEMPERATURES
IN THE 35 TO 40 RANGE SHOULD BE COMMON. A FEW SHOWERS MAY LINGER INTO
THE EARLY EVENING HOURS FOR LATER SHIFTS TO CONSIDER...BUT FOR NOW I
WILL CONTINUE A DRY FORECAST FOR TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 AM CDT MON APR 20 2015
SEASONABLY COOL AND MAINLY DRY FOR MUCH OF THE WEEK WITH FROST/FREEZE
POTENTIAL LATER IN THE WEEK.
NORTHWEST FLOW PATTERN WILL GOVERN MUCH OF THE LONG TERM PERIOD AS
BLOCKING DEVELOPS OVER EASTERN ATLANTIC AND GREENLAND RESULTING IN
SLOW EASTWARD PROGRESSION OF GREAT LAKES UPPER LOW. SERIES OF
IMPULSES WILL ROTATE AROUND THE CYCLONE WITH NORTHERN CWA IN CLOSER
PROXIMITY AND THUS FAVORED FOR MORE DIURNAL DRIVEN CLOUD COVER ON
TUESDAY ALONG WITH SPRINKLES AND SOME LIGHT POPCORN SHOWERS GIVEN
STEEP LAPSE RATES...COLD AIR ALOFT AND PRESENCE OF SKINNY CAPE NOTED
ON FORECAST SOUNDINGS. MAIN ITEM ON TUESDAY WILL BE WINDY CONDITIONS
WITH POTENTIAL FOR WIND ADVISORY AS NAM/GFS BUFR SOUNDINGS SHOWING
30-35 KTS OF WIND ON AVERAGE THROUGH THE MIXED LAYER WITH 50-55 KTS
SITTING ATOP DEEP MIXED LAYER TO NEAR 650 MB. POSSIBLE AS WELL THAT
ANY SHOWERS COULD ENHANCE WIND GUSTS VIA EVAPORATIVE COOLING OF
PCPN IN LARGE... DRY SUB-CLOUD LAYER WITH CLASSIC INVERTED V TYPE
SOUNDINGS.
CANADIAN SURFACE RIDGE AXIS WILL BUILD IN OVER THE LATTER HALF OF THE
WEEK AS THE UPPER LOW PLODS EASTWARD FROM GREAT LAKES. THIS WILL
BRING DIMINISHING WINDS WEDNESDAY THROUGH FRIDAY BUT ALSO REINFORCE
COOL... DRY AIR WITH MORE IDEAL RADIATIONAL COOLING SETUP LEADING TO
INCREASING RISK FOR AREAS OF FROST AND FREEZING TEMPS POSSIBLY AS
EARLY AS WEDNESDAY AM... BUT MORE LIKELY THURSDAY/FRIDAY AM. FREEZE
HIGHLIGHTS ARE ACTIVE IF NEEDED WITH FRUIT TREES NOW SUSCEPTIBLE
TO TEMPS AT/BELOW 28F PER FEEDBACK FROM ISU EXTENSION COMMERCIAL
HORTICULTURE SPECIALIST. NURSERIES AND STORES ALSO MOVING
STOCK OUTDOORS... AND RECENT WARM SPELL AND MOISTURE HAS CAUSED YARDS
TO ADVANCE QUICKLY.
TOWARD SATURDAY AND INTO THE FIRST HALF OF THE WEEKEND THERE IS THE
POTENTIAL FOR RAIN CHANCES WITH ANOTHER STORM SYSTEM. CONFIDENCE IS
LOW AS MODEL VARIANCE QUITE HIGH. DPROG/DT... OR COMPARISON OF MODELS
RUN TO RUN... SHOWS BETTER CONSISTENCY EXISTS WITH ECMWF WHICH IS
SLOWER AND FAVORS SOUTHERN CWA FOR BETTER RAIN CHANCES DUE TO MORE
SOUTHERLY TRACK OF SYSTEM AND INCREASING EASTERLY FLOW. GFS ENSEMBLE
MEANS SIMILAR LINES OF ECMWF AND ACTUALLY SUGGEST MUCH IF NOT ALL OF
RAIN STAYING TO OUR SOUTH FROM PARTS OF MID TO LOWER MISSISSIPPI VLY
WHICH ALSO FITS WITH PATTERN OF LATE. AS RESULT... HAVE ADJUSTED POPS
TO LOWER OR REMOVE ACROSS THE NORTH/EAST FRIDAY NIGHT AND SATURDAY AND
PLACE THE BEST CHANCES ACROSS THE SOUTHERN CWA.
TEMPS THROUGHOUT THE ENTIRE PERIOD LOOK TO REMAIN SEASONABLY COOL WITH
HIGHS 50S/60S... AND LOWS MAINLY IN THE 30S WITH SOME 20S IN FAVORED
DRAINAGE LOCATIONS WEDNESDAY THROUGH FRIDAY MORNINGS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1230 PM CDT MON APR 20 2015
BROAD CYCLONIC FLOW OVER CORN BELT AND GREAT LAKES IS LEADING TO
COLD AIR ADVECTION STRATUS ALONG WITH DIURNAL CONVECTION. GAPS IN
CLOUD COVER FILLED IN QUICKLY EARLIER TODAY WITH HEATING. CEILINGS
MAINLY IN VFR CATEGORY BUT SOME MVFR THE FURTHER NORTH YOU GO...INTO
THE SYNOPTIC STRATUS. STRONG NORTHWEST FLOW ALSO CREATING HAVOC WITH
AVIATION...BUT PRESSURE GRADIENT SHOULD BEGIN TO RELAX SOMEWHAT AS
AFTERNOON WEARS ON. COULD ALSO SEE SOME INSTABILITY SHOWERS DEVELOP
BUT THEY WILL REMAIN SPOTTY AND SHOULD HAVE LIMITED IMPACT.
DIURNAL CLOUDS THIS AFTERNOON SHOULD CLEAR OUT THIS EVENING...SO
CLOUDS WILL VARY FROM MOSTLY CLEAR SOUTH TO MOSTLY CLOUDY NORTH BUT
SHOULD REMAIN VFR.
ANOTHER WAVE IN NORTHWEST FLOW AROUND LARGE UPPER LOW WILL LEAD TO
MORE DIURNAL CLOUD DEVELOPMENT ON TUESDAY. PRESSURE GRADIENT THAT
DEVELOPS WITH THIS FEATURE COULD BE TIGHTER THAN TODAY SO EXPECT
EVEN STRONGER WINDS IN OUTER FORECAST HOURS AND INTO NEXT TAF UPDATE.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...HAASE
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...MCCLURE
AVIATION...SHEA
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
550 PM EDT MON APR 20 2015
.SYNOPSIS...
LOW PRESSURE MEANDERING NORTH OF THE GREAT LAKES WILL DRIVE A COLD
FRONT TOWARD THE REGION TONIGHT. THE FRONT WILL SLOWLY CROSS THE
REGION ON TUESDAY. LOW PRESSURE NORTH OF THE GREAT LAKES WILL
GRADUALLY WEAKEN AS IT DRIFTS SOUTHEAST INTO NEW ENGLAND WEDNESDAY
THROUGH THURSDAY. LOW PRESSURE WILL CONTINUE TO WEAKEN AS IT
MEANDERS NORTH OF NEW ENGLAND FRIDAY THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
UPDATE...HAVE MODIFIED THE GRIDS THRU MORNING BASED ON LATEST
HI-RES MODEL GUIDANCE. EXAMINING RECENT HRRR RUNS HAVE A LARGE
AREA FAVORABLE FOR LIGHTNING DEVELOPMENT MOVING ACROSS THE REGION
ON THE LEADING EDGE OF THE DRY SLOT NEAR MORNING. IN
ADDITION...THE SPC SSEO PRODUCTS ALSO FAVOR A CLUSTER OR LINE OF
TSTMS CROSSING THE FORECAST AREA NEAR 12Z. HAVE INCREASED THE
PROBABILITY FOR THUNDER LATE TONIGHT AND EARLY TUE AS A RESULT.
HAVE ALSO INTRODUCED SOME AREAS OF HEAVY RA TO THE GRIDS NEAR THE
COASTAL FRONT AS WELL AS IN THE EAST SLOPES OF THE MTNS WHERE
STRONG SELY LLJ WILL IMPINGE UPON THE TERRAIN.
THIS LLJ...WHICH IS REALLY JUST GETTING UNDERWAY OVER SRN NEW
ENGLAND PER KBOX 88D...WILL SLOWLY TRAVERSE THE COAST THRU ABOUT
06Z. THIS PUTS HEAVIEST PRECIP IN THE FORECAST AREA BETWEEN ABOUT
00Z AND 06Z. IN ADDITION TO THE HEAVY PRECIP...THIS LLJ MAY INDUCE
SOME STRONG DOWNSLOPE WIND GUSTS NW OF THE WHITE MTNS.
PREVIOUS DISCUSSION...THE FIRST BATCH OF RAIN FROM THIS MORNING
WAS MOVING INTO EASTERN MAINE AS A WARM FRONT LIFTED NORTH INTO
SOUTHERN CANADA. SO FAR ONLY A TENTH TO ABOUT A THIRD OF AN INCH
OF RAIN HAS FALLEN TODAY WITH SOME ISOLATED HIGHER AMOUNTS. THIS
MORNINGS GYX SOUNDING HAD PLENTY OF DRY AIR AND THIS INHIBITED
RAINFALL FROM SPREADING FASTER FOR THE FIRST HALF OF THE DAY.
STEADIER RAINS ARE NOW OVER SOUTHERN NH AND MOVING INTO WESTERN
MAINE. THIS TREND WILL CONTINUE INTO THE EVENING HOURS.
A SECONDARY CYCLONE WILL FORM TONIGHT OVER THE VIRGINIAS AND MOVE
NE ALONG THE ATLANTIC COAST. AS IT DEEPENS IN THE GULF OF MAINE A
LLJ WILL STRENGTHEN AND FEED MOISTURE RICH AIR INTO COASTAL NH AND
MAINE. WARM RAIN PROCESSES AND TRAINING OF CELLS WILL SUPPORT HEAVY
RAIN OVERNIGHT AND INTO TUESDAY. A FLOOD WATCH REMAINS IN EFFECT AS
RAIN COMBINES WITH SNOWMELT TO BRING RIVERS AND STREAMS TO NEAR
BANKFULL.
WINDS WILL BE GUSTY... ESPECIALLY ALONG THE COAST... BUT WE
SHOULD FALL SHORT OF WIND ADVISORY CRITERIA. COASTAL FLOODING WILL
ALSO BE A CONCERN FROM PORTLAND WESTWARD AS EASTERLY FLOW
INCREASES AND COINCIDES WITH THE ASTRONOMICAL HIGH TIDE. MORE
INFORMATION ON THESE HAZARDS BELOW.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
MODERATE TO HEAVY RAIN CONTINUES INTO TUESDAY MORNING. MUCAPE
VALUES INDICATE A SLIGHT CHANCE FOR THUNDERSTORMS BETWEEN 12-18Z
TOMORROW AS THE COLD CORE OF THE UPPER LOW SWINGS BY OVERHEAD.
DRIER AIR PUNCHES IN FROM THE SW MIDDAY TUESDAY. SOME LINGERING
SHOWERS WILL BE POSSIBLE OVER THE MOUNTAINS IN UPSLOPE FLOW. HIGHS
SHOULD WARM INTO THE UPPER 40S NORTH TO LOWER 60S SOUTH.
ADDITIONAL SHOWERS WILL BE POSSIBLE TUESDAY NIGHT WITH CYCLONIC
FLOW ALOFT.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
BROAD UPPER LEVEL CLOSED LOW WILL KEEP WEATHER UNSETTLED
IN THE NORTHEAST THROUGH THE WEEK AND INTO THE WEEKEND AS
IT GRADUALLY SHIFTS EAST. EXPECT SEVERAL LOBES OF ENERGY
TO ROTATE AROUND THIS SYSTEM AND INTO THE NORTHEAST. ANY
MORNING SUN ON WEDNESDAY WILL QUICKLY GIVE WAY TO CLOUDS
AND SHOWERS AS THE FIRST OF THESE DISTURBANCES SWINGS INTO
THE REGION. EXPECT THESE SHOWERS TO PERSIST INTO WEDNESDAY
NIGHT AS A WEAK SURFACE LOW SLOWLY CROSSES THE REGION.
STEADIER PRECIP WILL COME TO AN END AS LOW PRESSURE LIFTS INTO
THE MARITIMES ON THURSDAY. EXPECT CLOUDY SKIES AND SCATTERED
SHOWERS THURSDAY THROUGH FRIDAY WITH HIGHS IN THE 40S TO LOWER
50S.
SHOWER ACTIVITY WILL DIMINISH OVER THE WEEKEND BUT SKIES WILL
REMAIN MOSTLY CLOUDY WITH RAIN OR SNOW SHOWERS POSSIBLE MAINLY IN
NORTHERN ZONES.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
SHORT TERM...MVFR WILL DETERIORATE TO LIFR AND IFR SHORTLY AS
HEAVIER RAIN MOVES IN. RAIN MAY BE LIGHTER AT KHIE WHERE WE WILL
SEE THE RAIN SHADOW EFFECT. ALSO SOME SNOW MAY MIX IN LATE IN THE
NORTH. EAST WINDS MAY GUST TO 35 KTS AT TIMES. SOME IMPROVEMENT BY
MID MORNING TUESDAY AS RAIN MOVES EAST.
LONG TERM...AREAS OF MVFR CEILINGS WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
SHORT TERM...EASTERLY WINDS AND SEAS CONTINUE TO BUILD TONIGHT. A
GALE WARNING REMAINS IN EFFECT THROUGH 2 PM TUESDAY. WINDS WILL
DECREASE BUT A SCA WILL LIKELY BE NEEDED FOR WAVES THROUGH
WEDNESDAY EVENING.
LONG TERM...SCA`S MAY BE NEEDED THURSDAY AND FRIDAY.
&&
.FIRE WEATHER...
ONSHORE FLOW TODAY BRINGS MORE MOISTURE AND EVENTUALLY RAIN TO
THE AREA. A SOAKING RAIN IS EXPECTED LATE TODAY AND TUESDAY.
&&
.HYDROLOGY...
A WIDESPREAD 1 TO 2 INCHES OF RAIN IS EXPECTED FROM THIS
AFTERNOON THROUGH TUESDAY. HOWEVER...GIVEN STRONG MOISTURE
INFLOW...LOCALIZED AMOUNTS OF UP TO 3 INCHES COULD OCCUR. THIS
WOULD LEAD TO FLOODING PROBLEMS...ESPECIALLY IN AREAS WHERE SNOW
MELT IS STILL OCCURRING. A FLOOD WATCH REMAINS IN EFFECT.
&&
.TIDES/COASTAL FLOODING...
AS EASTERLY WINDS CONTINUE TO INCREASE...SEAS WILL BUILD 10 TO 15
FT. HIGH TIDE ON APRIL 21 IS AT 1:21 AM WITH A PREDICTED HEIGHT OF
11.4 FT MLLW. HOWEVER...ONSHORE WINDS ARE EXPECTED TO RESULT IN A 1-
2 FT STORM SURGE. THE COMBINATION OF WIND, WAVES AND HIGH TIDE WILL
RESULT IN OVERWASH AND POSSIBLE INUNDATION FOR THE BEACHES OF THE
SOUTH COAST OF MAINE AND NEW HAMPSHIRE. FARTHER DOWNEAST THE
EASTERLY WIND DIRECTION IS LESS FAVORABLE FOR ONSHORE INUNDATION.
EVEN SO THE SIGNIFICANT WAVES MAY RESULT IN SOME COASTAL FLOODING
AND A COASTAL FLOOD ADVISORY HAS BEEN POSTED THERE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR MEZ007>009-012>014-
018>028.
COASTAL FLOOD ADVISORY FROM 11 PM THIS EVENING TO 3 AM EDT
TUESDAY FOR MEZ025>028.
COASTAL FLOOD WARNING FROM 11 PM THIS EVENING TO 3 AM EDT
TUESDAY FOR MEZ023-024.
NH...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR NHZ002>015.
COASTAL FLOOD WARNING FROM 11 PM THIS EVENING TO 3 AM EDT
TUESDAY FOR NHZ014.
MARINE...GALE WARNING UNTIL 2 PM EDT TUESDAY FOR ANZ150>154.
&&
$$
NEAR TERM...LEGRO
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
303 PM EDT MON APR 20 2015
.SYNOPSIS...
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL ACCOMPANY A
COLD FRONT LATE TODAY AND THIS EVENING. THE COLD FRONT WILL CROSS
THE AREA TONIGHT. HIGH PRESSURE BUILDS BACK IN FROM THE SOUTHWEST
ON TUESDAY. ANOTHER COLD FRONT CROSSES THE AREA WEDNESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
SEVERE THUNDERSTORM WATCH 89 HAS BEEN ISSUED FOR PORTIONS OF THE
ERN VA PIEDMONT...CNTRL VA AND NRN VA UNTIL 10 PM.
AS OF NOON...
LATEST WX ANALYSIS DEPICTS WARM FRONT JUST NORTH OF
THE LOCAL AREA WITH A TRAILING COLD FRONT EXTENDING FROM ~985MB
LOW PRESSURE OVER THE GREAT LAKES SWD TO THE LOWER MS VALLEY.
ALOFT...UPPER LOW HAS LOCATED OVER THE UPPER MIDWEST WITH TROUGH
AXIS EXTENDING SWD ALONG THE MS VALLEY. LATEST REGIONAL RADAR
MOSAIC DEPICTS LAST NIGHTS SHOWERS WELL OFFSHORE WITH DRY
CONDITIONS OVER MUCH OF THE MID-ATLANTIC REGION. SKIES AVG MOSTLY
CLOUDY.
FOR TODAY...SFC LOW LIFTS NWD INTO SRN ONTARIO THIS AFTERNOON AS
THE COLD FRONT APPROACHES THE LOCAL AREA. SEVERAL PERTURBATIONS IN
INCREASING SWLY FLOW ALOFT WILL LIFT TOWARD THE REGION. THE
AIRMASS OVER THE LOCAL AREA WILL BECOME INCREASINGLY WARM/MOIST
AND UNSTABLE...ESPECIALLY WITH A FEW HOLES IN THE CLOUD COVER
EXPECTED THIS AFTERNOON. THETA E ADVECTION ALONG WITH TEMPS IN THE
LOW-MID 80S AND DEWPOINTS AROUND 60 WILL RESULT IN A MARGINALLY
UNSTABLE AIRMASS...WITH MLCAPE VALUES PER RAP GUIDANCE IN THE
1000-1500 J/KG RANGE. MODELS ALSO INDICATE VERY LITTLE MLCIN.
WHILE THERE WILL BE VERY LITTLE INHIBITION THIS AFTERNOON...EXPECT
PRECIP TO STAY TIED TO THE FRONT/CONVERGENCE ZONE. EXPECT
MOISTURE ADVECTION TO RAMP UP IN ADVANCE OF THE FRONT...WITH
PRECIP WATERS APPROACHING 1-1.25 INCHES.
COLD FRONT REACHES THE ERN VA PIEDMONT MID-LATE AFTERNOON. HI-RES
GUIDANCE INDICATING VERY LITTLE CONVECTION ALONG THE FRONT AS IT
CROSSES THE CNTRL APPALACHIANS...BUT ONCE THE FRONT REACHES THE
AIRMASS OVER THE PIEDMONT...MODELS INDICATE INITIATION AROUND
3-5PM THIS AFTERNOON OVER THE PIEDMONT. MODE EXPECTED TO START
OFF AS DISCRETE CELLS...BUT 30-40 KT OF EFFECTIVE BULK SHEAR WILL
TRANSITION TO A LINE FROM THE PIEDMONT INTO CNTRL VIRGINIA. QUICK
W-SW MID LEVEL FLOW WILL PUSH STORMS QUICKLY TO THE E-NE...WITH
THE BEST CHANCES REMAINING ALONG THE INSTABILITY AXIS FROM THE
PIEDMONT INTO CNTRL VA. STORMS PROGGED TO REACH CNTRL VA LATE
TODAY-EARLY THIS EVENING...AND THEN POINTS EWD THRU THE EVENING.
WHILE MORE INSTABILITY IS PROGGED ACROSS THE SE...EVENING TIMING
AND DECREASING SHEAR IS NOT FAVORABLE TO MAINTAIN LINE SEGMENTS
INTO THAT AREA. HI-RES GUIDANCE ALSO BACKS THIS UP. HAVE INCREASED
POPS TO LIKELY ACROSS THE PIEDMONT NEWD TO THE MD ERN SHORE...WITH
HIGH END CHANCE SOUTH AND EAST. DAMAGING WIND GUSTS AND LARGE HAIL
ARE POSSIBLE THANKS TO DEEP INSTABILITY...FAVORABLE LAPSE RATES
AND A RELATIVELY LOW FREEZING LEVEL. TORNADO RISK REMAINS LOW
THANKS TO GOOD MIXING AND HIGH LCL HEIGHTS. THE BEST RISK FOR
SEVERE WEATHER WILL BE ACROSS THE LIKELY POP AREA WITH ISOLATED
STRONG TO SEVERE STORMS STILL POSSIBLE OVER THE SE. BRIEF HEAVY
RAINFALL ALSO EXPECTED...BUT MOVEMENT WILL LIMIT ANY FLOODING
POTENTIAL.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
A COLD FRONT CROSSES THE FA TONIGHT WITH CHC POPS...THEN
DRYING/COOLER WESTERLY FLOW TAKING OVR INTO TUE. PARTLY/MOSTLY
SUNNY TUE WITH HIGH TEMPS IN THE UPR 60S TO NR 70 AT THE
COAST...AND LOW/MID 70S ELSEWHERE.
HIGH PRES MOVES TO NR THE SE CONUS COAST BY WED...PROVIDING WSW
FLOW AND CONTINUING MILD WX. A WEAK TROUGH WILL BE APPROACHING
FROM THE WNW...WHICH SHOULD RESULT IN INCREASING CLOUDS AND THE
POSSIBILITY OF AFTERNOON SHOWERS (ISOLD TSTMS). LOW TEMPS TUE NGT
MID 40S WEST AND NORTH TO LOW 50S SE. HIGH TEMPS WED IN THE
LOW/MID 70S...EXCEPT 60S AT THE IMMEDIATE COAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
BROAD CYCLONIC FLOW PREVAILS THRU THE EXTENDED PERIOD AS UPPER
CLOSED LOW REMAINS IN VIC OF THE GREAT LAKES AND NEW ENGLAND. TO
BEGIN THE PERIOD...FAST MOVING COLD FRONT CROSSES THE REGION LATE
WEDS NIGHT-EARLY THURS MORNING. GFS CONTINUES TO REMAIN ON THE
SLOWER SIDE OF MODEL GUIDANCE WRT FRONTAL PASSAGE...WITH THE ECMWF
QUICKER. BASED ON WLY FLOW ALOFT AND HIGH PRESSURE BACK OVER THE
MIDWEST...OPTED TO REINTRODUCE SLIGHT CHANCE POPS WEDS NIGHT OVER
THE NRN AND NERN ZONES AND THEN THURS SOUTH AND EAST OF
RICHMOND...TRENDING SLIGHTLY TOWARD THE SLOWER GFS. HIGHS THURS
AROUND NORMAL...LOW-MID 60S. THEREAFTER...COOL HIGH PRESSURE BUILDS
SWD FROM THE CANADIAN PRAIRIES INTO THE MIDWEST...EXTENDING INTO THE
MID-ATLANTIC REGION FRI. HIGHS FRI GENERALLY IN THE UPPER 50S NE TO
MID 60S SE UNDER A PARTLY CLOUDY SKY AND NWLY WINDS. SRN STREAM
SHORTWAVE PROGGED TO LIFT INTO THE MIDWEST FRI NIGHT-SAT WITH
ASSOCIATED SFC LOW FORECAST TO PROGRESS EWD ALONG A STATIONARY
BOUNDARY OVER THE GULF STATES SAT. MOISTURE RETURNS SAT TO GO ALONG
WITH OVERRUNNING AND WEAK PERTURBATIONS ALOFT. INCREASED POPS TO
SLIGHT CHANCE N TO CHANCE S. HIGHS SAT GENERALLY AROUND 60 ACROSS
THE REGION. SFC LOW MOVES OFF THE CAROLINA COAST SAT NIGHT...WITH
ANY REMAINING PRECIP EXPECTED ACROSS THE SE LOCAL AREA. HIGH
PRESSURE RETURNS SUN...BUT COOL CONDITIONS PERSIST WITH HIGHS IN THE
UPPER 50S NE TO LOW 60S SE.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
THE FRONTAL RAINBAND IS MOVING OFFSHORE THIS MORNING. CONDITIONS
ARE IMPROVING AND SHOULD CONTINUE THROUGH THE MORNING. CLOUD
COVER ACTUALLY SCATTERING OUT BY THIS AFTERNOON...ALONG WITH A
GUSTY SW WIND. A SECONDARY IMPULSE TRACKS ACROSS THE REGION LATE
THIS AFTERNOON AND EVENING BRINGING A CHC OF SHOWERS/TSTMS. ANY
TSTMS COULD CONTAIN STRONG WIND GUSTS. A COLD FRONT THEN MOVES OFF
THE COAST LATER TONIGHT...WITH HIGH PRESSURE BUILDING INTO THE
REGION TUESDAY...BEFORE MOVING OFFSHORE WEDNESDAY. A COLD FRONT
CROSSES THE AREA WEDNESDAY NIGHT WITH A SLIGHT CHC OF SHOWERS.
HIGH PRESSURE RETURNS THURSDAY AND FRIDAY.
&&
.MARINE...
LOW PRESSURE IS LIFTING NNE OVER THE GREAT LAKES EARLY THIS
MORNING...WITH SECONDARY LOW PRESSURE OVER THE MID ATLANTIC. 3 TO
5 FT WAVES IN THE MOUTH OF THE BAY WILL CONTINUE THROUGH THE
AFTN. SEAS HAVE RISEN TO 5-8FT...AND WILL LIKELY REACH 6-9FT EARLY
TODAY...BEFORE SLOWLY SUBSIDING LATER TODAY THROUGH TUESDAY. A
FRONTAL BOUNDARY IS PRESENTLY CROSSING THE AREA AND SHOULD MOVE
OFFSHORE BY 12Z (15Z FARTHER NE). EXPECT THE WIND TO BECOME
SOUTHERLY BEHIND THE FRONT WITH SPEEDS RELAXING TO 10-15KT.
INHERITED SCA FLAGS REMAIN AS IS. HOWEVER...THE RIVERS COULD
POTENTIALLY END EARLIER THAN THE CURRENT 10 AM TIME. THIS WILL BE
RECONSIDERED AT THE 11Z/7 AM UPDATE. OTHERWISE...A COLD FRONT
APPROACHES FROM THE W THIS AFTERNOON/EVENING...AND MOVES ACROSS
THE COAST LATE TONIGHT. THIS FRONT IS EXPECTED TO TRIGGER
SHOWERS/TSTMS...WHICH WILL HAVE THE POTENTIAL OF PRODUCING STRONG
WIND GUSTS. HIGH PRESSURE BUILDS ACROSS THE SOUTHEAST TUESDAY AND
WEDNESDAY AS LOW PRESSURE LINGERS OVER THE GREAT LAKES. A WEAK
COLD FRONT CROSSES THE REGION WEDNESDAY NIGHT WITH HIGH PRESSURE
RETURNING THURSDAY AND FRIDAY.
&&
.HYDROLOGY...
AVG QPF 0.75-2.00"...LOCALLY UP TO 2.50" OVR MOST OF THE RIVER
BASINS WILL RESULT IN RIVER LVLS TO PSBLY RISE TO 1/2-NR FULL
BANKFULL TUE INTO WED.
&&
.TIDES/COASTAL FLOODING...
SOUTHERLY FLOW TODAY INTO THIS EVENING WILL HELP MAINTAIN ~1.0 FT
ANOMALIES IN THE MIDDLE BAY THROUGH TONIGHT. TIDAL ANOMALIES WILL
BEGIN TO SUBSIDE TUESDAY AS THE FLOW BECOMES OFFSHORE. NO
STATEMENTS HAVE BEEN ISSUED AT THIS TIME...BUT BISHOPS HEAD WILL
COME CLOSE TO THEIR 3.25FT MINOR THRESHOLD.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ634.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT TUESDAY FOR ANZ654-656-658.
SMALL CRAFT ADVISORY UNTIL 1 PM EDT TUESDAY FOR ANZ650-652.
&&
$$
SYNOPSIS...JDM
NEAR TERM...SAM
SHORT TERM...ALB/JDM
LONG TERM...SAM
AVIATION...AJZ
MARINE...AJZ
HYDROLOGY...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
353 PM EDT MON APR 20 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM EDT MON APR 20 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEPENING UPR TROF
OVER CENTRAL NAMERICA BTWN RDGS ALONG THE E AND W COASTS...WITH 12HR
H5 HGT FALLS UP TO 150M NOTED OVER NRN WI IN ADVANCE OF SHRTWV
LIFTING NWD INTO THE UPR LKS TO THE E OF THE UPR TROF AXIS. IR AND
WV IMAGERY SHOW A WELL DEFINED COMMA HEAD CLD OVER THE UPR GREAT LKS
IN ADVANCE OF SHRTWV AND ON CYC SIDE OF ACCOMPANYING H7 LO TRACK.
STEADY RA UNDER THIS COMMA HEAD HAS MIXED WITH SN OVER THE WRN CWA
WHERE DYNAMIC COOLING AND SOME LLVL CAA HAVE COOLED THE COLUMN
SUFFICIENTLY. FARTHER TO THE E...DRY SLOTTING ON THE ACYC SIDE OF H7
LO TRACK HAS TENDED TO DIMINISH THE PCPN COVERAGE/INTENSITY OVER THE
FAR E. ANOTHER SHRTWV IS DIGGING SWD THRU FAR NW ONTARIO/MANITOBA ON
THE WRN FLANK OF H5 CLOSED LO
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/PTYPE ASSOCIATED
WITH SHRTWV MOVING THRU THE UPR LKS RIGHT NOW AND THEN TNGT/TMRW
ACCOMPANYING PASSAGE OF NEXT SHRTWV AND WITHIN LINGERING DEEP CYC
FLOW UNDER CUTOFF H5 LO PROGGED TO LINGER OVER THE UPR LKS.
LATE TDAY/TNGT...AS SHRTWV E OF THE UPR TROF AXIS LIFTS TO THE N
THRU THIS AFTN AND TENDS TO SHEAR OUT...MODELS SHOW AREA OF SHARP
DEEP LYR QVECTOR CNVGC SUPPORTING AXIS OF COLDER CLD TOPS
DIMINISHING AND GIVING WAY TO SOME DEEP LYR QVECTOR DVGC. SO AREA OF
STEADY RA/SN OVER THE W SHOULD DIMINISH BY LATE AFTN WITH ARRIVAL OF
THE NEGATIVE DYNAMICS/MID LVL DRYING. POPS OVER THE E WL TEND TO
INCREASE LATE THIS AFTN/EARLY EVNG AS COMMA TAIL AXIS OF HIER RH
SWINGS E THRU THAT AREA...BUT PCPN INTENSITY WL NOT BE AS GREAT AS
OVER THE W SINCE THE SUPPORTING AXIS OF DIMINISHING DEEP LYR QVECTOR
CNVGC IS FCST TO REMAIN OVER THE W. NOT OUT OF THE QUESTION THERE
COULD BE A FEW INCHES OF WET SN ACCUM OVER THE HIER TERRAIN OF THE
W...BUT THERE SHOULD BE LTL IF ANY SN OVER THE E HALF WITH WEAKER
DYNAMIC FORCING/COOLING. LATER TNGT...THE TRAILING SHRTWV DIGGING
SWD TOWARD NW MN ON THE WRN FLANK OF CLOSED H5 LO IS FCST TO DIG TO
NEAR NW WI BY 12Z TUE...BRINGING SOME DPVA/MORE DEEP LYR QVECTOR
CNVGC TO THE W LATER TNGT. SHARP CYC UPSLOPE WNW FLOW IN THE
PRESENCE OF THE DEEPER FORCING/MSTR WL SUPPORT LIKELY POPS IN THIS
AREA. THERE COULD BE A FEW INCHES OF WET SN ACCUM OVER MAINLY THE
HIER TERRAIN. OVER THE CENTRAL AND E...THERE WL BE ONLY ISOLD-SCT RA
AND SN SHOWERS.
TUE...SHRTWV/ACCOMPANYING SFC LO PRES TROF ROTATING ARND CLOSED H5
LO SHIFTING SLOWLY TO THE E OVER LK SUP IS FCST TO WEAKEN SLOWLY...
LEADING TO SLOWLY DIMINISHING DEEP LYR QVECTOR CNVGC. ALTHOUGH THESE
TRENDS WL RESULT IN DIMINISHING POPS...DAYTIME HEATING/LLVL
DESTABILIZATION WL ENHANCE POPS ESPECIALLY OVER THE ERN CWA IN THE
AFTN...WHERE LLVL CNVGC WITHIN LO PRES TROF WL BE ENHANCED BY LK
BREEZE DEVELOPMENT. OTRW...LINGERING SHARP LLVL CNVGC AND THE
DAYTIME HEATING WL MAINTAIN AT LEAST CHC POPS. THE PCPN SHOULD BE
MAINLY SN IN THE MRNG...BUT THIS PCPN WL MIX WITH/CHG TO RA OVER THE
SE HALF IN THE AFTN WITH DAYTIME HEATING/TEMPS RISING AOA 40.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015
A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.
AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).
EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015
AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 353 PM EDT MON APR 20 2015
SHARP PRES GRADIENT ON THE SW FLANK OF SLOW MOVING LO PRES IN
ONTARIO WILL CAUSE W TO NW WINDS UP TO 25-30 KTS INTO THU. ALTHOUGH
THERE COULD BE SOME GALE FORCE GUSTS AT TIMES...WIDESPREAD GALES ARE
NOT EXPECTED. THE CLOSER APPROACH OF HI PRES LATER IN THE WEEK WILL
RESULT IN NW WINDS DIMINISHING TO NO MORE THAN 20 KTS ON FRI AND
SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 PM EDT MON APR 20 2015
.SYNOPSIS...A COLD FRONT WILL TRACK EAST ACROSS THE REGION TONIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE SOUTHWEST LATE TONIGHT THROUGH
TUESDAY... THEN SHIFT OFF THE COAST TUESDAY NIGHT INTO WEDNESDAY.
A COLD FRONT WILL APPROACH FROM THE NORTH WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...
NOW THROUGH THIS EVENING: NUMEROUS SIGNALS CONTINUE TO SUPPORT AN
ENHANCED RISK OF SEVERE STORMS IN CENTRAL NC. HEATING/MIXING
DISSIPATED THE WEAK CAP OVER THE REGION NEARLY 2 HOURS AGO...
YIELDING EXPLOSIVE CONVECTION TO OUR SW OVER NE GA AND UPSTATE SC.
SEE NO REASON WHY THIS WON`T CONTINUE TO EXPAND NORTHEASTWARD TOWARD
CENTRAL NC OVER THE NEXT FEW HOURS. KINEMATICS REMAIN ROBUST WITH
EFFECTIVE DEEP LAYER SHEAR OVER 40 KTS (ACCORDING TO SPC
MESOANALYSES) AND RAP ANALYSES REVEALING A LONG STRAIGHT LINE
HODOGRAPH SUPPORTIVE OF SPLITTING SUPERCELLS. MLCAPE AND MUCAPE
VALUES ARE RAPIDLY GROWING AND NOW SIT NEAR 1000 J/KG AND 1500-2000
J/KG RESPECTIVELY... AND LOW LEVEL LAPSE RATES HAVE REACHED NEAR 8
C/KM. THESE FACTORS ALONG WITH DERIVED PARAMETERS INCLUDING THE
CRAVEN SIGSVR AND SUPERCELL COMPOSITE PARAMETER SUPPORT SUSTAINED
SUPERCELLS. PW VALUES ARE ABOVE NORMAL BUT NOT INCREDIBLY HIGH...
AND THIS MAY LIMIT COVERAGE SOMEWHAT INITIALLY... BUT ALL
INDICATIONS ARE THAT CONVECTION WILL GROW AND CONGEAL INTO A LINEAR
MCS OR OR MULTICELL CLUSTERS AFFECTING A LARGER AREA. DAMAGING
STRAIGHT LINE WINDS AND LARGE HAIL STILL LOOK TO BE THE PRIMARY
THREATS... GIVEN THE LONG STRAIGHT HODOGRAPH AND FAT CAPE IN THE 0C
TO -30C LAYER WITH CONVECTION ALLOWING MODELS INDICATING STRONG
UPDRAFTS. INTENSE TORNADOES LOOK TO BE LESS LIKELY WITH LCL HEIGHTS
UP TO 1000 M CURRENTLY AND SOMEWHAT MARGINAL STORM RELATIVE HELICITY
VALUES... BUT A FEW TORNADOES REMAIN POSSIBLE IN THIS ENVIRONMENT.
STORM MOTION IS EXPECTED TO BE 40-50 MPH FROM THE WSW... AND THESE
TRANSLATIONAL SPEEDS WILL EXACERBATE THE EFFECTS OF ANY STRONG WINDS
ASSOCIATED WITH INDIVIDUAL STORMS. STRONG TO SEVERE CONVECTION NOW
OVER THE GSP CWA WILL CONTINUE TO EXPAND TO THE NE... SO EXPECT THE
GREATEST SEVERE RISK OVER CENTRAL NC TO BE BETWEEN 4 PM AND 8 PM...
GRADUALLY TAPERING DOWN AFTERWARD... WITH LITTLE MORE THAN ISOLATED
TRAILING SHOWERS AFTER 11 PM.
AFTER MIDNIGHT: THE COLD FRONT WILL MOVE ESE THROUGH CENTRAL NC
BETWEEN MIDNIGHT AND 6 AM... AND EXPECT CLEARING SKIES WITH THE
ONSET OF DOWNSLOPE LOW LEVEL FLOW AND A DRYING COLUMN. STILL EXPECT
LOWS FROM AROUND 50 IN THE NW TO AROUND 60 SE AS COOLER AIR RUSHES
IN LATE. -GIH
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 PM MONDAY...
THE COLD FRONT WILL HAVE PUSHED JUST SE OF THE FORECAST AREA BY
DAYBREAK TUE... WITH HIGH PRESSURE BUILDING IN FROM THE GULF
STATES... THEN DRIFTING ACROSS GA/SRN SC. FORECAST SOUNDINGS SHOW A
STABLE AND DRY COLUMN WITH JUST A FEW FLAT CU NEAR THE TOP OF THE
MIXED LAYER IN THE AFTERNOON. A PASSING WEAK VORTICITY MAX COULD
ALSO BRING A STREAM OF MID/HIGH CLOUDS IN THE EVENING. HIGHS BELOW
NORMAL AT 68-74 WITH PARTLY TO MOSTLY SUNNY SKIES. MOSTLY CLEAR TUE
NIGHT WITH THE HIGH SHIFTING OFF THE COAST. LOWS 44-50. -GIH
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
WEDNESDAY THROUGH THURSDAY NIGHT...DRY CONDITIONS WILL PERSIST ON
WEDNESDAY AS HIGH PRESSURE ACROSS THE SOUTHEAST US GRADUALLY SLIPS
OFFSHORE WEDNESDAY MORNING/EARLY AFTERNOON. ANOTHER COLD FRONT WILL
APPROACH THE AREA LATE WEDNESDAY INTO THURSDAY. HOWEVER...LIMITED
MOISTURE RETURN AHEAD OF THIS SYSTEM WILL KEEP PRECIP CHANCES
MINIMAL. NEVERTHELESS...WILL KEEP A SLIGHT CHANCE POP IN THE
FORECAST FOR WEDNESDAY NIGHT/EARLY THURSDAY...BUT MOST PLACES WILL
LIKELY STAY DRY AND THOSE THAT SEE PRECIP WILL HAVE MEAGER AMOUNTS.
HIGHS ON WEDNESDAY WILL RISE INTO THE MID/UPPER 70S...WHILE ON
THURSDAY HIGHS WILL RANGE FROM THE UPPER 60S ACROSS THE NORTH
(EARLIER FRONTAL PASSAGE) TO THE MID 70S FURTHER SOUTH. OVERNIGHT
LOWS WILL GENERALLY BE IN THE MID/UPPER 40S TO LOWER 50S (COOLEST
THURSDAY NIGHT BEHIND THE FRONT).
FRIDAY THROUGH MONDAY...UNCERTAINTY REMAINS FAIRLY HIGH WITH RESPECT
TO THE END OF THE WEEK AND ESPECIALLY INTO THE WEEKEND. THE OVERALL
PATTERN INDICATES THE AFOREMENTIONED COLD FRONT WILL STALL JUST
SOUTH OF THE REGION FOR THE END OF THE WEEK. THEN...AS A SOUTHERN
STREAM SYSTEM APPROACHES...MULTIPLE WAVES OF LOW PRESSURE WILL RIDE
ALONG THIS BOUNDARY...SPREADING PRECIP BACK INTO THE AREA.
HOWEVER...AS CAN BE EXPECTED THIS FAR OUT...DETAILS HAVE YET TO BE
WORKED OUT. REGARDLESS...WILL SHOW POPS EARLY IN THE WEEKEND WITH...
AS OF NOW AT LEAST...DRIER CONDITIONS BY SUNDAY. MONDAY ALSO LOOKS
TO BE DRY...BUT ANOTHER SYSTEM IS PROGGED TO BE ON OUR DOORSTEP BY
LATE MONDAY/MONDAY NIGHT. TEMPS WILL GENERALLY BE NEAR TO SLIGHTLY
BELOW NORMAL THROUGH THE TIME FRAME.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 1230 PM MONDAY...
EARLIER MVFR CIGS AT INT/GSO/RDU/FAY HAVE SCATTERED OUT... AND
EXPECT RWI TO FOLLOW SUIT AND BECOME SCT IN THE NEXT HOUR. SCATTERED
STORMS ARE EXPECTED TO FORM OVER NRN GA AND UPSTATE SC THEN MOVE TO
THE NE... LIKELY AFFECTING INT/GSO 19Z-23Z... RDU 20Z-00Z... AND
FAY/RWI 21Z-01Z. VFR CONDITIONS WILL GENERALLY CONTINUE FOR THE NEXT
24 HRS... BUT CIGS/VSBYS IN AND NEAR STORMS WILL DROP TO MVFR OR
BRIEFLY IFR. ENHANCED WIND GUSTS OVER 50 MPH AND HAIL GREATER THAN 1
INCH IN DIAMETER REMAIN POSSIBLE WITH THESE SCATTERED STORMS. EVEN
OUTSIDE OF STORMS... WINDS FROM THE SW AT 10-15 KTS GUSTING TO 20-30
KTS WILL PERSIST... VEERING AROUND TO WESTERLY WITH DIMINISHING
GUSTS AFTER PASSAGE OF A COLD FRONT AFTER 04Z. A SHORT PERIOD OF
MVFR CIGS ARE POSSIBLE WITH FRONTAL PASSAGE... BUT GENERALLY WE
EXPECT VFR CONDITIONS LATE TONIGHT THROUGH THE END OF THE TAF VALID
PERIOD WITH MOSTLY CLEAR SKIES.
LOOKING BEYOND 18Z TUE... VFR CONDITIONS SHOULD HOLD THROUGH WED AS
HIGH PRESSURE BUILDS OVER THE REGION. A FEW HOURS OF SUB-VFR
CIGS/VSBYS WITH A FEW SHOWERS ARE POSSIBLE WED EVENING/NIGHT INTO
EARLY THU AS A DISTURBANCE MOVES QUICKLY ACROSS THE DEEP SOUTH AND
SOUTHEAST STATES. VFR CONDITIONS AND COOLER WEATHER WILL FOLLOW FOR
LATE THU INTO SAT. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...KRD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
312 PM EDT MON APR 20 2015
.SYNOPSIS...A COLD FRONT WILL TRACK EAST ACROSS THE REGION TONIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE SOUTHWEST LATE TONIGHT THROUGH
TUESDAY... THEN SHIFT OFF THE COAST TUESDAY NIGHT INTO WEDNESDAY.
A COLD FRONT WILL APPROACH FROM THE NORTH WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...
NOW THROUGH THIS EVENING: NUMEROUS SIGNALS CONTINUE TO SUPPORT AN
ENHANCED RISK OF SEVERE STORMS IN CENTRAL NC. HEATING/MIXING
DISSIPATED THE WEAK CAP OVER THE REGION NEARLY 2 HOURS AGO...
YIELDING EXPLOSIVE CONVECTION TO OUR SW OVER NE GA AND UPSTATE SC.
SEE NO REASON WHY THIS WON`T CONTINUE TO EXPAND NORTHEASTWARD TOWARD
CENTRAL NC OVER THE NEXT FEW HOURS. KINEMATICS REMAIN ROBUST WITH
EFFECTIVE DEEP LAYER SHEAR OVER 40 KTS (ACCORDING TO SPC
MESOANALYSES) AND RAP ANALYSES REVEALING A LONG STRAIGHT LINE
HODOGRAPH SUPPORTIVE OF SPLITTING SUPERCELLS. MLCAPE AND MUCAPE
VALUES ARE RAPIDLY GROWING AND NOW SIT NEAR 1000 J/KG AND 1500-2000
J/KG RESPECTIVELY... AND LOW LEVEL LAPSE RATES HAVE REACHED NEAR 8
C/KM. THESE FACTORS ALONG WITH DERIVED PARAMETERS INCLUDING THE
CRAVEN SIGSVR AND SUPERCELL COMPOSITE PARAMETER SUPPORT SUSTAINED
SUPERCELLS. PW VALUES ARE ABOVE NORMAL BUT NOT INCREDIBLY HIGH...
AND THIS MAY LIMIT COVERAGE SOMEWHAT INITIALLY... BUT ALL
INDICATIONS ARE THAT CONVECTION WILL GROW AND CONGEAL INTO A LINEAR
MCS OR OR MULTICELL CLUSTERS AFFECTING A LARGER AREA. DAMAGING
STRAIGHT LINE WINDS AND LARGE HAIL STILL LOOK TO BE THE PRIMARY
THREATS... GIVEN THE LONG STRAIGHT HODOGRAPH AND FAT CAPE IN THE 0C
TO -30C LAYER WITH CONVECTION ALLOWING MODELS INDICATING STRONG
UPDRAFTS. INTENSE TORNADOES LOOK TO BE LESS LIKELY WITH LCL HEIGHTS
UP TO 1000 M CURRENTLY AND SOMEWHAT MARGINAL STORM RELATIVE HELICITY
VALUES... BUT A FEW TORNADOES REMAIN POSSIBLE IN THIS ENVIRONMENT.
STORM MOTION IS EXPECTED TO BE 40-50 MPH FROM THE WSW... AND THESE
TRANSLATIONAL SPEEDS WILL EXACERBATE THE EFFECTS OF ANY STRONG WINDS
ASSOCIATED WITH INDIVIDUAL STORMS. STRONG TO SEVERE CONVECTION NOW
OVER THE GSP CWA WILL CONTINUE TO EXPAND TO THE NE... SO EXPECT THE
GREATEST SEVERE RISK OVER CENTRAL NC TO BE BETWEEN 4 PM AND 8 PM...
GRADUALLY TAPERING DOWN AFTERWARD... WITH LITTLE MORE THAN ISOLATED
TRAILING SHOWERS AFTER 11 PM.
AFTER MIDNIGHT: THE COLD FRONT WILL MOVE ESE THROUGH CENTRAL NC
BETWEEN MIDNIGHT AND 6 AM... AND EXPECT CLEARING SKIES WITH THE
ONSET OF DOWNSLOPE LOW LEVEL FLOW AND A DRYING COLUMN. STILL EXPECT
LOWS FROM AROUND 50 IN THE NW TO AROUND 60 SE AS COOLER AIR RUSHES
IN LATE. -GIH
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 345 AM MONDAY...
DRY CONDITIONS WILL PREVAIL IN THE WAKE OF THE COLD FRONT TUE/TUE
NIGHT...WITH HIGHS IN THE UPPER 60S TO LOWER 70S AND LOWS MID/UPPER
40S TO PERHAPS 50F FAR SE COASTAL PLAIN WED MORNING. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
WEDNESDAY THROUGH THURSDAY NIGHT...DRY CONDITIONS WILL PERSIST ON
WEDNESDAY AS HIGH PRESSURE ACROSS THE SOUTHEAST US GRADUALLY SLIPS
OFFSHORE WEDNESDAY MORNING/EARLY AFTERNOON. ANOTHER COLD FRONT WILL
APPROACH THE AREA LATE WEDNESDAY INTO THURSDAY. HOWEVER...LIMITED
MOISTURE RETURN AHEAD OF THIS SYSTEM WILL KEEP PRECIP CHANCES
MINIMAL. NEVERTHELESS...WILL KEEP A SLIGHT CHANCE POP IN THE
FORECAST FOR WEDNESDAY NIGHT/EARLY THURSDAY...BUT MOST PLACES WILL
LIKELY STAY DRY AND THOSE THAT SEE PRECIP WILL HAVE MEAGER AMOUNTS.
HIGHS ON WEDNESDAY WILL RISE INTO THE MID/UPPER 70S...WHILE ON
THURSDAY HIGHS WILL RANGE FROM THE UPPER 60S ACROSS THE NORTH
(EARLIER FRONTAL PASSAGE) TO THE MID 70S FURTHER SOUTH. OVERNIGHT
LOWS WILL GENERALLY BE IN THE MID/UPPER 40S TO LOWER 50S (COOLEST
THURSDAY NIGHT BEHIND THE FRONT).
FRIDAY THROUGH MONDAY...UNCERTAINTY REMAINS FAIRLY HIGH WITH RESPECT
TO THE END OF THE WEEK AND ESPECIALLY INTO THE WEEKEND. THE OVERALL
PATTERN INDICATES THE AFOREMENTIONED COLD FRONT WILL STALL JUST
SOUTH OF THE REGION FOR THE END OF THE WEEK. THEN...AS A SOUTHERN
STREAM SYSTEM APPROACHES...MULTIPLE WAVES OF LOW PRESSURE WILL RIDE
ALONG THIS BOUNDARY...SPREADING PRECIP BACK INTO THE AREA.
HOWEVER...AS CAN BE EXPECTED THIS FAR OUT...DETAILS HAVE YET TO BE
WORKED OUT. REGARDLESS...WILL SHOW POPS EARLY IN THE WEEKEND WITH...
AS OF NOW AT LEAST...DRIER CONDITIONS BY SUNDAY. MONDAY ALSO LOOKS
TO BE DRY...BUT ANOTHER SYSTEM IS PROGGED TO BE ON OUR DOORSTEP BY
LATE MONDAY/MONDAY NIGHT. TEMPS WILL GENERALLY BE NEAR TO SLIGHTLY
BELOW NORMAL THROUGH THE TIME FRAME.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 1230 PM MONDAY...
EARLIER MVFR CIGS AT INT/GSO/RDU/FAY HAVE SCATTERED OUT... AND
EXPECT RWI TO FOLLOW SUIT AND BECOME SCT IN THE NEXT HOUR. SCATTERED
STORMS ARE EXPECTED TO FORM OVER NRN GA AND UPSTATE SC THEN MOVE TO
THE NE... LIKELY AFFECTING INT/GSO 19Z-23Z... RDU 20Z-00Z... AND
FAY/RWI 21Z-01Z. VFR CONDITIONS WILL GENERALLY CONTINUE FOR THE NEXT
24 HRS... BUT CIGS/VSBYS IN AND NEAR STORMS WILL DROP TO MVFR OR
BRIEFLY IFR. ENHANCED WIND GUSTS OVER 50 MPH AND HAIL GREATER THAN 1
INCH IN DIAMETER REMAIN POSSIBLE WITH THESE SCATTERED STORMS. EVEN
OUTSIDE OF STORMS... WINDS FROM THE SW AT 10-15 KTS GUSTING TO 20-30
KTS WILL PERSIST... VEERING AROUND TO WESTERLY WITH DIMINISHING
GUSTS AFTER PASSAGE OF A COLD FRONT AFTER 04Z. A SHORT PERIOD OF
MVFR CIGS ARE POSSIBLE WITH FRONTAL PASSAGE... BUT GENERALLY WE
EXPECT VFR CONDITIONS LATE TONIGHT THROUGH THE END OF THE TAF VALID
PERIOD WITH MOSTLY CLEAR SKIES.
LOOKING BEYOND 18Z TUE... VFR CONDITIONS SHOULD HOLD THROUGH WED AS
HIGH PRESSURE BUILDS OVER THE REGION. A FEW HOURS OF SUB-VFR
CIGS/VSBYS WITH A FEW SHOWERS ARE POSSIBLE WED EVENING/NIGHT INTO
EARLY THU AS A DISTURBANCE MOVES QUICKLY ACROSS THE DEEP SOUTH AND
SOUTHEAST STATES. VFR CONDITIONS AND COOLER WEATHER WILL FOLLOW FOR
LATE THU INTO SAT. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...VINCENT
LONG TERM...KRD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
230 PM EDT MON APR 20 2015
.SYNOPSIS...A COLD FRONT WILL TRACK EAST ACROSS THE REGION TONIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE SOUTHWEST LATE TONIGHT THROUGH
TUESDAY... THEN SHIFT OFF THE COAST TUESDAY NIGHT INTO WEDNESDAY.
A COLD FRONT WILL APPROACH FROM THE NORTH WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...
NOW THROUGH THIS EVENING: NUMEROUS SIGNALS CONTINUE TO SUPPORT AN
ENHANCED RISK OF SEVERE STORMS IN CENTRAL NC. HEATING/MIXING
DISSIPATED THE WEAK CAP OVER THE REGION NEARLY 2 HOURS AGO...
YIELDING EXPLOSIVE CONVECTION TO OUR SW OVER NE GA AND UPSTATE SC.
SEE NO REASON WHY THIS WON`T CONTINUE TO EXPAND NORTHEASTWARD TOWARD
CENTRAL NC OVER THE NEXT FEW HOURS. KINEMATICS REMAIN ROBUST WITH
EFFECTIVE DEEP LAYER SHEAR OVER 40 KTS (ACCORDING TO SPC
MESOANALYSES) AND RAP ANALYSES REVEALING A LONG STRAIGHT LINE
HODOGRAPH SUPPORTIVE OF SPLITTING SUPERCELLS. MLCAPE AND MUCAPE
VALUES ARE RAPIDLY GROWING AND NOW SIT NEAR 1000 J/KG AND 1500-2000
J/KG RESPECTIVELY... AND LOW LEVEL LAPSE RATES HAVE REACHED NEAR 8
C/KM. THESE FACTORS ALONG WITH DERIVED PARAMETERS INCLUDING THE
CRAVEN SIGSVR AND SUPERCELL COMPOSITE PARAMETER SUPPORT SUSTAINED
SUPERCELLS. PW VALUES ARE ABOVE NORMAL BUT NOT INCREDIBLY HIGH...
AND THIS MAY LIMIT COVERAGE SOMEWHAT INITIALLY... BUT ALL
INDICATIONS ARE THAT CONVECTION WILL GROW AND CONGEAL INTO A LINEAR
MCS OR OR MULTICELL CLUSTERS AFFECTING A LARGER AREA. DAMAGING
STRAIGHT LINE WINDS AND LARGE HAIL STILL LOOK TO BE THE PRIMARY
THREATS... GIVEN THE LONG STRAIGHT HODOGRAPH AND FAT CAPE IN THE 0C
TO -30C LAYER WITH CONVECTION ALLOWING MODELS INDICATING STRONG
UPDRAFTS. INTENSE TORNADOES LOOK TO BE LESS LIKELY WITH LCL HEIGHTS
UP TO 1000 M CURRENTLY AND SOMEWHAT MARGINAL STORM RELATIVE HELICITY
VALUES... BUT A FEW TORNADOES REMAIN POSSIBLE IN THIS ENVIRONMENT.
STORM MOTION IS EXPECTED TO BE 40-50 MPH FROM THE WSW... AND THESE
TRANSLATIONAL SPEEDS WILL EXACERBATE THE EFFECTS OF ANY STRONG WINDS
ASSOCIATED WITH INDIVIDUAL STORMS. STRONG TO SEVERE CONVECTION NOW
OVER THE GSP CWA WILL CONTINUE TO EXPAND TO THE NE... SO EXPECT THE
GREATEST SEVERE RISK OVER CENTRAL NC TO BE BETWEEN 4 PM AND 8 PM...
GRADUALLY TAPERING DOWN AFTERWARD... WITH LITTLE MORE THAN ISOLATED
TRAILING SHOWERS AFTER 11 PM.
AFTER MIDNIGHT: THE COLD FRONT WILL MOVE ESE THROUGH CENTRAL NC
BETWEEN MIDNIGHT AND 6 AM... AND EXPECT CLEARING SKIES WITH THE
ONSET OF DOWNSLOPE LOW LEVEL FLOW AND A DRYING COLUMN. STILL EXPECT
LOWS FROM AROUND 50 IN THE NW TO AROUND 60 SE AS COOLER AIR RUSHES
IN LATE. -GIH
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 345 AM MONDAY...
DRY CONDITIONS WILL PREVAIL IN THE WAKE OF THE COLD FRONT TUE/TUE
NIGHT...WITH HIGHS IN THE UPPER 60S TO LOWER 70S AND LOWS MID/UPPER
40S TO PERHAPS 50F FAR SE COASTAL PLAIN WED MORNING. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 120 AM MONDAY...
DRY WEATHER EXPECTED WEDNESDAY AND THURSDAY.
HIGH CONFIDENCE FORECAST FOR MID WEEK AS HIGH PRESSURE WILL DOMINATE
AND BRING DRY WEATHER WITH SEASONABLY COOL TEMPERATURES WEDNESDAY
AND THURSDAY.
CONFIDENCE RAPIDLY DECREASES IN THE FORECAST BY FRIDAY THROUGH THE
WEEKEND AS MODELS SHOW SPREAD WITH HANDLING THE PROGRESSIVELY MOVING
SOUTHERN STREAM SYSTEM THAT MAY AFFECT OUR REGION AS EARLY AS
FRIDAY. JUST HOW THIS SYSTEM INTERACTS WITH THE POLAR JET AND THE
ASSOCIATED LOW LEVEL BOUNDARY WILL DETERMINE HOW QUICKLY THIS SYSTEM
MOVES AND HOW FAR NORTH THE SIGNIFICANT RAINFALL REACHES INTO THE MID-
ATLANTIC STATES. FOR NOW... WE WILL CARRY A CHANCE OF SHOWERS FOR
THE WEEKEND (CENTERED ON SATURDAY INTO SATURDAY NIGHT).
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 1230 PM MONDAY...
EARLIER MVFR CIGS AT INT/GSO/RDU/FAY HAVE SCATTERED OUT... AND
EXPECT RWI TO FOLLOW SUIT AND BECOME SCT IN THE NEXT HOUR. SCATTERED
STORMS ARE EXPECTED TO FORM OVER NRN GA AND UPSTATE SC THEN MOVE TO
THE NE... LIKELY AFFECTING INT/GSO 19Z-23Z... RDU 20Z-00Z... AND
FAY/RWI 21Z-01Z. VFR CONDITIONS WILL GENERALLY CONTINUE FOR THE NEXT
24 HRS... BUT CIGS/VSBYS IN AND NEAR STORMS WILL DROP TO MVFR OR
BRIEFLY IFR. ENHANCED WIND GUSTS OVER 50 MPH AND HAIL GREATER THAN 1
INCH IN DIAMETER REMAIN POSSIBLE WITH THESE SCATTERED STORMS. EVEN
OUTSIDE OF STORMS... WINDS FROM THE SW AT 10-15 KTS GUSTING TO 20-30
KTS WILL PERSIST... VEERING AROUND TO WESTERLY WITH DIMINISHING
GUSTS AFTER PASSAGE OF A COLD FRONT AFTER 04Z. A SHORT PERIOD OF
MVFR CIGS ARE POSSIBLE WITH FRONTAL PASSAGE... BUT GENERALLY WE
EXPECT VFR CONDITIONS LATE TONIGHT THROUGH THE END OF THE TAF VALID
PERIOD WITH MOSTLY CLEAR SKIES.
LOOKING BEYOND 18Z TUE... VFR CONDITIONS SHOULD HOLD THROUGH WED AS
HIGH PRESSURE BUILDS OVER THE REGION. A FEW HOURS OF SUB-VFR
CIGS/VSBYS WITH A FEW SHOWERS ARE POSSIBLE WED EVENING/NIGHT INTO
EARLY THU AS A DISTURBANCE MOVES QUICKLY ACROSS THE DEEP SOUTH AND
SOUTHEAST STATES. VFR CONDITIONS AND COOLER WEATHER WILL FOLLOW FOR
LATE THU INTO SAT. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
116 PM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH THIS EVENING AND MOVE OFFSHORE LATE
MONDAY NIGHT. HIGH PRESSURE BUILDS OVER THE REGION TUESDAY AND
WEDNESDAY. A WEAK COLD FRONT WILL CROSS THE AREA THURSDAY. ANOTHER
DISTURBANCE WILL AFFECT THE REGION NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 110 PM MONDAY...STRONG SUBSIDENCE ACROSS THE REGION FOR MUCH
OF THE DAY THUS FAR...BUT A GOOD CUMULUS FIELD DEVELOPING ACROSS
THE REGION NOW. PER LATEST RUNS OF THE 3KM HRRR AND RAP...EXPECT
SHOWERS/TSTMS TO APPROACH OUR WESTERN COUNTIES AROUND 21Z-23Z WITH
ADDITIONAL SHOWERS/TSTMS DEVELOPING FURTHER EAST NEAR THE COAST
LATER IN THE EVENING. INSTABILITY SHOULD INCREASE DURING THE LATE
AFTERNOON/EVENING WITH GOOD SOLAR HEATING. MINIMAL CHANGES TO
CURRENT FORECAST AT THIS TIME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 430 AM MONDAY...THE FRONT WILL CROSS THE AREA EARLY
TUESDAY. THE CHALLENGE WILL BE THE EXTENT OF PRECIPITATION AHEAD
OF THE FRONT AND IF STORMS WILL DEVELOP/MOVE INTO THE AREA. GIVEN
THE TIMING OF THE FRONT...FEEL THE CHANCE OF THUNDERSTORMS WILL BE
LIMITED AS PEAK HEATING WILL HAVE ALREADY OCCURRED.
FURTHERMORE...THE BEST SYNOPTIC FORCING...SFC FRONT AND PEAK
HEATING WILL NOT COEXIST GIVING THIS SCENARIO A LOW CONFIDENCE
LEVEL IN TERMS OF THUNDERSTORM DEVELOPMENT AND SUBSTAINABILITY.
GIVEN MARGINAL LIFT...INSTABILITY AND SHEAR...WE CAN NOT RULE OUT
DISCRETE THUNDERSTORMS POSSIBLY BECOMING LINEAR IN NATURE DURING
THE EVENING HOURS...BUT THE OVERALL SPATIAL EXTENT LOOKS MINIMAL.
BY THE TIME THE MID-LEVEL DRY AIR BECOMES BETTER
SATURATED...INSTABILITY WILL HAVE DIMINISH QUITE A BIT. IF THE
FRONT MOVES A BIT FASTER THAN ANTICIPATED OR THERE IS BETTER
LIFT/SATURATION AHEAD OF THE FRONT...THEN THERE MAY BE BETTER
SPATIAL COVERAGE OF THUNDERSTORMS. AT THIS TIME...WE FEEL ANY
ACTIVITY WILL WANE AS IT CROSSES EASTERN NC DURING THE EVENING
HOURS. KEPT A CHANCE POP IN FOR THE TIME BEING. PRECIPITATION
CHANCES SHOULD DIMINISH AFTER 10Z WITH THE FRONT MOVING THROUGH BY
12Z. LOWS IN THE LOW 60S INLAND TO MID 60S ALONG THE BEACHES.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 545 AM MON...ONLY MINOR CHANGES FOR THE LONG TERM FORECAST
WITH MODELS IN MODEST AGREEMENT THROUGH THE MEDIUM RANGE. FOR
TUESDAY/WEDNESDAY...SEASONABLY MILD CONDITIONS WITH WARM DAYS AND
COOL NIGHTS EXPECTED AS ZONAL FLOW BRINGS NEAR CLIMO TEMPS AND DRY
WEATHER TO THE REGION. HIGHS SHOULD GENERALLY BE IN THE 70S WITH
LOWS IN THE UPR 40S TO MID 50S.
WEDNESDAY NIGHT/THURSDAY...SOME MINOR DIFFERENCES IN MOISTURE
AVAILABILITY WITH COLD FRONT THAT WILL SAG INTO THE AREA ON
THURSDAY. HAVE CONTINUED TO SIDE WITH DRIER SOLN WITH GFS
APPEARING TO HAVE A WET BIAS. DETERMINISTIC ECMWF MORE IN LINE
WITH ITS ENSEMBLE MEAN IN KEEPING THE AREA DRY...THEREFORE HAVE NO
HIGHER THAN A 20 POP LATE WED NIGHT INTO THUR. ANOTHER SEASONABLE
DAY ON THUR WITH HIGHS IN THE 70S AS WINDS SHIFT NORTHWESTERLY
BEHIND THE FRONT.
THURSDAY NIGHT/FRIDAY...DRY WEATHER BEHIND THE FRONT WITH SUNNY DRY
AND COOLER WEATHER. SLIGHTLY BELOW CLIMO EXPECTED WITH LOWS IN THE
40S TO NEAR 50 AND HIGHS IN THE MID 60S TO NEAR 70.
FRIDAY NIGHT/SATURDAY...A PRONOUNCED SOUTHERN STREAM SYSTEM MAY
AFFECT THE AREA THIS WEEKEND. SIGNIFICANT TIMING DIFFERENCES EXIST
THIS FAR OUT HOWEVER AND MAINTAINED THE SMALL CHANCE POPS IN THE
FCST. TEMPS WILL LIKELY REMAIN BELOW CLIMO DUE TO THE INCREASED
CLOUDS AND PRECIP WITH THE AREA ON THE COOL SIDE OF THE FRONTAL
BOUNDARY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 18Z TUESDAY/...
AS OF 115 PM MONDAY...NICE CUMULUS FIELD HAS DEVELOPED ACROSS THE
REGION THIS AFTERNOON WITH VFR CONDITIONS PREVAILING. GUIDANCE
INDICATES PERHAPS A BRIEF PERIOD OF MVFR CEILINGS IN SCATTERED
CONVECTION LATE TONIGHT. COLD FRONT MOVES OFFSHORE BETWEEN 06Z AND
12Z WITH DRIER AIR MOVING IN AND VFR CONDITIONS EXPECTED TO
PREVAIL THROUGH TUESDAY.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 550 AM MON...HIGH PRESSURE BUILDS ACROSS EASTERN NC TUESDAY
INTO WEDNESDAY YIELDING MOSTLY VFR CONDITIONS. A WEAK FRONT WILL
MOVE SOUTH INTO EASTERN NC THURSDAY BUT WITH LIMITED MOISTURE SO
EXPECT MOSTLY VFR CONDITIONS THURSDAY. A BETTER CHANCE FOR PRECIP
ARRIVES NEXT WEEKEND.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 115 PM MONDAY...SW WINDS CONTINUE AT 10 TO 15 KNOTS WITH
SOME GUSTS TO 20 KNOTS OVER THE CENTRAL AND NORTHERN WATERS. SEAS
5 TO 7 FEET NORTH AND 3 TO 6 FEET SOUTH. NO CHANGES NEEDED TO THE
MARINE FORECAST AT THIS TIME.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 550 AM MON...SEAS WILL REMAIN ELEVATED INTO TUESDAY MORNING
AND CURRENT SCA FOR ALL COASTAL WATERS WILL REMAIN IN EFFECT UNTIL
12Z TUESDAY. HIGH PRESSURE WILL BUILD OVER THE NC WATERS TUESDAY
INTO WEDNESDAY WITH WINDS SHIFTING MORE WESTERLY, 5-15 KT. SEAS
WILL DIMINISH TO 2-4 FT TUESDAY NIGHT THROUGH WEDNESDAY. A COLD
FRONT WILL MOVE SOUTH INTO THE NORTHERN WATERS THURSDAY AND SHIFT
SOUTH OF THE WATERS BY THURSDAY NIGHT. WINDS VEER NORTHWEST BEHIND
THE FRONT BUT REMAIN 5-15 KT WITH PLEASANT BOATING CONDITIONS
EXPECTED AND SEAS AROUND 2 TO 3 FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR AMZ150-152-154-
156-158.
&&
$$
SYNOPSIS...CTC/LEP
NEAR TERM...CTC
SHORT TERM...LEP
LONG TERM...DAG
AVIATION...TL/CTC
MARINE...CTC/DAG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
102 PM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY BRINGING ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS. DRY HIGH PRESSURE BUILDS IN FOR TUESDAY
AND WEDNESDAY. ANOTHER COLD FRONT WILL PUSH IN FROM THE NORTHWEST ON
THURSDAY...POSSIBLY BRINGING SHOWERS BACK TO THE AREA. A STRONGER
STORM SYSTEM WILL MOVE IN FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM...GUSTY TSTMS...WHAT APPEAR TO BE DRIVEN BY MCV...
SHOULD TRANSLATE QUICKLY EAST OF THE CWFA BY 15 UTC. IT SEEMS
LIKE THERE WILL BE SVRL HOURS OF ECHO FREE CONDITIONS ACRS THE
CWFA. WITHIN THE BROAD PRE-COLD FRONTAL ENVIRONMENT...PROGRESSIVE
DESTABILIZATION IS EXPECTED THROUGH THE AFTERNOON. THE NEWLY POSTED
12 UTC NAM AND CONVECTION ALLOWING MODELS EXPECTEDLY RESPOND
FAVORABLY WITHIN LLVL FRONTAL CONVERGENCE ZONE...PROGGING WIDESPREAD
DEEP CONVECTION. FAVORABLE SHEAR PROFILES LEND SUPPORT TO THE
PROBABILITY OF DISCRETE STORMS IN THE PIEDMONT LATER TODAY.
AS OF 645 AM...WELL THE NEAR TERM MODELS AND CAMS ARE NOT DOING VERY
WELL WITH THE CONVECTION ENTERING OUR WESTERN ZONES EARLY THIS
MORNING. HAVE BUMPED UP POP IN THE WEST. STILL EXPECT WEAKENING AS
THE REMNANT PRECIP CROSSES THE AREA THRU THE MORNING HOURS. CANNOT
RULE OUT A STRONG OR MARGINALLY SEVERE STORM EARLY ON...BUT
OTHERWISE JUST SOME CG LIGHTNING AND DOWNPOURS WITH THAT ACTIVITY.
THE REST OF THE FCST WAS LEFT UNCHANGED.
AS OF 330 AM...IN THE IMMEDIATE NEAR TERM...THE RADAR HAS GONE INTO
CLEAR AIR MODE...AS A LEAD SHORTWAVE HAS EXITED TO THE NE WITHIN
DEEP LAYER SWLY FLOW. A QUASI-LINEAR MCS IS CURRENTLY CROSSING
CENTRAL TN AND NRN AL. GUIDANCE SEEMS TO BE UNDERESTIMATING THE
STRENGTH/PERSISTENCE OF THIS SYSTEM. THE LATEST RAP ANALYSIS SHOWS
500-1000 J/KG OF MUCAPE WITH 35-45 KTS OF EFFECTIVE SHEAR DOWNSTREAM
OF THIS CLUSTER. THIS RESULTS IN A /MCS MAINTENANCE/ PROB AT 70-80
PCT. SO IT IS NOW EXPECTED THAT THESE STORMS (WHILE STILL ON A
GRADUAL WEAKENING TREND) WILL LIKELY STILL SURVIVE INTO THE NC MTNS
EARLY THIS MORNING. GIVEN THE CURRENT STATE...CANNOT RULE OUT A
STRONG OR SEVERE STORM OR TWO...ESP IN GRAHAM/SWAIN...WHEN THE LINE
GETS INTO THE CWFA. FROM THERE...IT/S DIFFICULT TO SAY HOW MUCH
PRECIP WILL LINGER ACRS THE CWFA THIS MORNING. I HAVE BUMPED UP POP
IN THE WRN MTNS...BUT KEEP JUST A SHOTGUN CHC POP FOR THE REST OF
THE AREA THIS MORNING.
LATER TODAY...GUIDANCE IN GOOD AGREEMENT ON ANOTHER SPOKE OF
VORTICITY ROTATING AROUND THE BROAD CYCLONICALLY CURVED
FLOW...CROSSING THE CWFA FROM THE SOUTHWEST DURING THE PEAK-HEATING
AFTN HOURS. MEANWHILE...A COLD FRONT WILL PUSH INTO THE AREA THIS
AFTN. THE FRONT LOOKS TO ONLY HAVE MODEST LLVL CONVERGENCE.
HOWEVER...GIVEN THE STEEP MID LVL LAPSE RATES AND LINGERING BL
MOISTURE (DEWPTS IN THE MID 60S ACRS THE PIEDMONT). FAIRLY CONFIDENT
IN AT LEAST 40-50 PCT COVERAGE OF CONVECTION...MAYBE HIGHER TO THE
EAST. THE FCST SNDGS SHOW LONG BUT SLIGHTLY CURVED HODOGRAPHS WITH
1500-2500 J/KG OF UNCAPPED SBCAPE. SO EXPECT SOMEWHAT DISCRETE
STORMS INITIALLY...WITH POTENTIAL FOR SUPERCELLS. DEFINITELY WILL
BE A DAMAGING WIND AND HAIL THREAT...WITH AN ISOLD TORNADO THREAT
ACRS THE PIEDMONT THIS AFTN. THE HIGH RES MODELS DO NOT SEEM THAT
IMPRESSED WITH COVERAGE OR INTENSITY. I/M NOT SURE WHAT IS LIMITING
THEIR CONVECTION EXPECT FOR PERHAPS LACK OF DEEPER MOISTURE. THE NEW
DAY 1 CONVECTIVE OUTLOOK STILL HAS ALL AREAS EAST OF THE MTNS IN THE
SLGT RISK...AND A MARGINAL RISK FOR THE MTNS. OTHERWISE...IT WILL BE
BREEZY TODAY UNDER MOSTLY CLOUDY TO PARTLY CLOUDY SKIES WITH TEMPS
BACK ABOVE NORMAL AHEAD OF THE FRONT.
TONIGHT...DRY AIR WILL FILTER IN FROM THE WEST BEHIND THE FRONT.
POPS WILL TAPER OFF...LINGERING THRU THE EVENING ALONG THE TN BORDER
DUE TO UPSLOPE NWLY FLOW. LOWS WILL BE A COUPLE CATEGORIES ABOVE
NORMAL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM MONDAY...THINGS DRY OUT TUE AS DRY HIGH PRESSURE BUILDS
IN FROM THE WEST. EXPECT A MILD AND BREEZY DAY WITH HIGHS UP TO 5
DEGREES BELOW NORMAL. A BROAD AND LOW AMPLITUDE UPPER TROF SETS UP
ACROSS THE AREA FOR WED. WEAK SHORT WAVES MOVING THRU THE TROF WILL
HELP PUSH A WEAK COLD FRONT INTO THE AREA WED AND SOUTH OF THE AREA
WED NITE. THERE IS NOT A LOT OF DEEP MOISTURE WITH THIS SYSTEM AND
THE FORCING IS WEAK. THEREFORE...EXPECT SCT SHRA NEAR THE TN BORDER
WHERE THE MOISTURE IS DEEPEST AND WLY FLOW WILL HELP INCREASE
FORCING. ELSEWHERE...ONLY ISOLATED SHRA ARE EXPECTED...WITH LITTLE
CHC OF PRECIP SOUTH OF I-85. HIGHS WILL RISE TO NEAR NORMAL WED...
WITH LOWS NEAR NORMAL TUE NITE AND ABOVE NORMAL WED NITE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 AM MONDAY...AN UPPER TROF AXIS WILL SLIDE EAST OF THE AREA
THURSDAY ALLOWING FLAT RIDGING TO BUILD IN ON FRI. A SHORT WAVE
CROSSES THE AREA SATURDAY WITH ANOTHER BROAD AND LOW AMPLITUDE UPPER
TROF DEVELOPING ON SUNDAY.
HIGH PRESSURE BRIEFLY RETURNS TO THE AREA FRI BEFORE A STRONGER
STORM SYSTEM MOVES IN ON SATURDAY. PRECIP CHC SLOWLY RAMPS UP FRIDAY
WITH POTENTIALLY HEAVY PRECIP ON SATURDAY. DRY HIGH PRESSURE RETURNS
FOR SUNDAY. NEAR NORMAL HIGHS THURSDAY...FALL BELOW NORMAL FOR THE
REST OF THE PERIOD. LOWS BOUNCE AROUND FROM NEAR TO A LITTLE ABOVE
NORMAL.
&&
.AVIATION /17Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...GUSTY SSW WINDS AHEAD OF AN APPROACHING COLD
FRONT WILL CONTINUE THIS AFTERNOON AS CU FIELD THICKENS AND EXPANDS.
THUNDERSTORM CVRG WILL ALSO CONTINUE TO BLOSSOM WITH TIME AND GIVEN
THE EXPECTED CVRG...A TEMPO TSRA WILL BE INCLUDED AT ALL TERMINAL
LOCATIONS ALONG WITH CIGS OCCASIONALLY DIPPING DIPPING TO MVFR.
CONVECTION ALLOWING MODELS DIMINISH TSTM CVRG 21-23Z TODAY FOLLOWED
BY LLVL DRYING/DROPPING SFC DWPTS AND THE INFLUX OF POST-FRONTAL
AIR. A WIND SHIFT TO WEST IS EXPECTED THIS EVENING AND GUSTS WILL
DROP OFF. CLEARING AND VFR CONDITIONS ARE ON TAP OVERNIGHT AND INTO
TUESDAY MORNING.
OUTLOOK...DRY HIGH PRESSURE WILL BUILD IN ACROSS THE REGION FOR THE
MIDDLE OF THE WEEK...LEADING TO LOW PRECIP/RESTRICTION CHANCES.
CONFIDENCE TABLE...
17-23Z 23-05Z 05-11Z 11-12Z
KCLT MED 60% HIGH 100% HIGH 100% HIGH 100%
KGSP MED 60% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU MED 60% HIGH 100% HIGH 100% HIGH 100%
KAND MED 70% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...ARK/CSH
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK/CSH
AREA FORECAST DISCUSSION
NWS AMARILLO TX
250 PM CDT MON APR 20 2015
.SHORT TERM... (TONIGHT)
THE SURFACE HIGH WILL CONTINUE TO SLIDE EAST ALLOWING FOR SOUTHERLY
FLOW TO BRING GULF MOISTURE INTO THE AREA AND BRINGING UPSLOPING
WINDS. THE UPPER LEVEL RIDGE OFF TO THE WEST IS ALSO MOVING
EASTWARD AND BRINGING A VORT LOBE THROUGH THE AREA. THESE TWO
LIFTING MECHANISMS WILL CREATE CHANCES FOR RAIN SHOWERS OVER THE
CENTRAL TO SOUTHERN TX PANHANDLE BETWEEN 6PM THROUGH 1AM. PREFERRED
THE GFS MODEL OVER NAM AS IT CAPTURED QPF LOCATIONS BETTER AS IT
AGREED WITH TEXAS TECH WRF AND HRRR MODELS. THUS WENT WITH MAV
GUIDANCE ON WINDS AND DEW POINTS. TONIGHT SHOULD BE WARMER THAN
LAST NIGHT DUE TO INCREASED CLOUD COVER AND THE SOUTHERLY FLOW
CREATING LOWS IN THE UPPER 30S TO MID 40S OVERNIGHT.
MB/CLK
.LONG TERM... (TOMORROW THROUGH SUNDAY)
THERE IS A VERY LOW PROBABILITY OF RESIDUAL CONVECTION IN THE FAR
EAST TOMORROW MORNING AS SUBTLE MID-LEVEL WAVE EXITS THE AREA. LATER
IN THE DAY WEAK HEIGHT FALLS OCCUR JUST TO OUR WEST AS CLOSED LOW IN
THE SOUTHWEST CONUS DEEPENS. ALTHOUGH SUBTLE (AND DESPITE STILL
RELATIVELY WEAK MEAN WESTERLY-NORTHWESTERLY FLOW) THIS SHOULD STILL
BE SUFFICIENT TO FORCE LEE SURFACE PRESSURE FALLS AND START THE
NORTHWESTWARD MOVEMENT OF LOW LEVEL MOISTURE BACK INTO THE AREA.
CURRENT SURFACE OBSERVATION SHOW OFF SHORE FLOW WITH RICH LOW LEVEL
MOISTURE LIMITED TO COASTAL AREAS AND DEEP SOUTH TEXAS. SHORT RANGE
GUIDANCE GENERALLY SHOWS THE EQUATORWARD PUSH OF THE COLD FRONT HAS
STOPPED AS SURFACE FLOW VEERING IN RESPONSE TO
STRENGTHENING/SOUTHEASTWARD MOVING SURFACE HIGH IN THE LOWER
MISSISSIPPI VALLEY. TIMING OF RELATIVELY RICH LOW-LEVEL MOISTURE IS
SOMEWHAT IN QUESTION GIVEN EVAPOTRANSPIRATIVE PARAMETRIZATION
POSSIBLY EXAGGERATING QUALITY OF MOISTURE RETURN INITIALLY. AM
CONCERNED THAT GOOD QUALITY MOISTURE RETURN MAY BE TOO RAPID THROUGH
LATE AFTERNOON/EARLY EVENING. SOME CONVECTION COULD FORM BY LATE
AFTERNOON BUT COVERAGE OF MEASURABLE PRECIPITATION SHOULD BE LIMITED
NECESSITATING ONLY SLIGHT CHANCE PROBABILITIES THROUGH EARLY EVENING.
0-2KM THETA-E VALUES TREND UPWARD NOTABLY AFTER DARK AND WITH
INCREASING LARGE SCALE FORCING PRECIPITATION PROBABILITIES SHOULD BE
MARKEDLY HIGHER DURING THE EVENING AND OVERNIGHT PERIOD...ESPECIALLY
ACROSS THE EASTERN PORTION OF THE FORECAST AREA. A COLD FRONT FORCED
BY A NORTHERN STREAM WAVE WILL REACH OUR AREA BY WEDNESDAY MORNING
WITH UNCERTAINTY INCREASING SOMEWHAT BY THIS TIME. THE BOUNDARY WILL
PROBABLY PROGRESS SLOWLY SOUTHWARD THROUGH THE AREA BY EVENING WITH
WEAK ISENTROPIC LIFT ATOP SHALLOW COOL LAYER RESULTING IN
CONVECTION. HAVE DIMINISHED PROBABILITIES OVERNIGHT AS MOIST UPGLIDE
OVER THE BOUNDARY WEAKENS AND MID LEVEL HEIGHTS RISE SOME.
CONFIDENCE IS A LITTLE HIGHER IN THE EXTENDED GIVEN BETTER AGREEMENT
OF MEDIUM RANGE DETERMINISTIC GUIDANCE AND LESS SPREAD IN THE
ENSEMBLE MEMBERS. BY THURSDAY A MUCH MORE SIGNIFICANT MID-UPPER
TROUGH IN THE SOUTHWEST APPROACHES CAUSING A FAIRLY DRAMATIC SURFACE
RESPONSE THROUGH FRIDAY. STRENGTHENING LEE TROUGH/LOW WILL RESULT IN
INCREASED LOW-LEVEL MOIST FLOW AGAIN AND WITH MIXING BY THURSDAY
AFTERNOON THE DRYLINE WILL SHARPEN ACROSS THE AREA. THE BEST
OPPORTUNITY FOR PRECIPITATION WITH THIS SYSTEM WILL BE THURSDAY
AFTERNOON AND EVENING AHEAD OF SHARPENING DRYLINE WHICH SEEMS MOST
LIKELY TO BE POSITIONED NORTH-SOUTH ACROSS THE CENTRAL PORTION OF
THE PANHANDLES.
GIVEN THE PROGRESSIVE NATURE OF THIS SYSTEM A PERIOD OF POST-DRYLINE
DEEP MIXING MAY OCCUR FRIDAY AFTERNOON WITH CONCERNS FOR FIRE WEATHER
POSSIBLY DEVELOPING THEN. BY THE WEEKEND IN THE WAKE OF THIS WAVE A
QUASI-ZONAL UPPER FLOW PATTERN EVOLVES WITH SOME FAIRLY SIZABLE
PERTURBATIONS SHOWING UP IN MEDIUM RANGE GUIDANCE...PARTICULARLY
AROUND SUNDAY. ALTHOUGH TIMING IS UNCERTAIN AT THIS POINT IN
TIME...DID MAINTAIN LOW PRECIPITATION PROBABILITIES ON SUNDAY.
BRB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
05/17
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
214 PM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION THIS AFTERNOON INTO
TONIGHT AND BRING SHOWERS AND SOME STRONG THUNDERSTORMS TO THE
REGION. WE WILL THEN SETTLE INTO A COOLER...BREEZY...AND SOMEWHAT
UNSETTLED PATTERN THROUGH THE MIDDLE OF THE WORKWEEK...WITH THE
BEST CHANCE OF MORE SHOWERS AND THUNDERSTORMS ARRIVING WITH
ANOTHER FRONT ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1024 AM EDT MONDAY...
ACTIVE WEATHER DAY WITH LINGERING FLOODING ISSUES FROM SUNDAY TO
SUNDAY NIGHT HEAVY RAINS AND A SEVERE WEATHER THREAT FOR THIS
AFTERNOON INTO TONIGHT WITH COLD FRONT. SWODY1 HAS ADDED AN
ENHANCED POTENTIAL (30 PERCENT) TO SLIGHT RISK WHICH COVERS MUCH
OF OUR FORECAST AREA TODAY. THE MAIN THREATS FOR THUNDERSTORMS
PRODUCING DAMAGING WINDS AND LARGE HAIL...ALONG WITH LOCALLY HEAVY
RAIN. MODIFIED MORNING 12Z RNK SOUNDING SUPPORTS CONCERNS WITH
MODIFIED CAPES AROUND 1000 TO 2000 J/KG WITH HEALTHY SHEAR AROUND
40 KNOTS. ADJUSTED TIMING OF POPS CLOSER TO A BLEND OF HRRR AND
WRFRNK-ARW. MODIFIED TEMPERATURES AND DEW POINTS WITH SFC OBS AND
MODEL TRENDS. COLD FRONT PUSHES EAST ACROSS REGION THIS AFTERNOON
INTO THIS EVENING...THEN HIGH PRESSURE BUILDS IN BEHIND FRONT
TUESDAY. MORE CHANGES THIS AFTERNOON...
AS OF 525 AM EDT MONDAY...
THERE ARE LINGERING HYDRO ISSUES EARLY THIS MORNING FOLLOWING THE
WIDESPREAD HEAVY RAIN FROM SUNDAY AND SUNDAY NIGHT...AND SEVERAL
FLOOD WARNINGS REMAIN IN EFFECT FROM THE NORTH CAROLINA MOUNTAINS
THROUGH THE GRAYSON HIGHLANDS AND INTO SOUTHWEST VIRGINIA UNTIL
AROUND 9AM. THE SITUATION WILL CONTINUED TO BE MONITORED WITH
ADJUSTMENTS MADE ACCORDINGLY.
THE NEXT CONCERN IS THE APPROACHING COLD FRONT SET TO CROSS THE
AREA THIS AFTERNOON. MESO MODELS DISSIPATE THE CONVECTIVE COMPLEX
CURRENTLY APPROACHING FROM THE WEST WITH REDEVELOPMENT FIRING
LATER THIS MORNING INTO THIS AFTERNOON ACROSS THE REGION...
ESPECIALLY FRONT HE BLUE RIDGE EAST. EARLY MORNING SATELLITE PICS
SHOW BREAKS IN THE CLOUD COVER AND WITH 850MB TEMPS AROUND 12C WE
SHOULD SEE SURFACE TEMPERATURES RISE WELL INTO THE 70S TODAY. THIS
WILL GENERATE CAPE VALUES OF 1000J/KG TO 1500J/KG WHICH WILL BE
ENOUGH TO SUPPORT VIGOROUS CONVECTION. LOW LEVEL WINDS WILL GIVE
US 0/6KM BULK SHEAR VALUES OF 40KTS TO 50KTS WITH A SOMEWHAT
LINEAR HODOGRAPH. THUS THERE IS ENOUGH INSTABILITY AND SHEAR
PRESENT FOR A SEVERE THREAT...AND THE SPC SLIGHT RISK LOOKS TO BE
ON TARGET. WILL BE ANTICIPATING STORM CLUSTERS EVOLVING INTO
LINEAR ELEMENTS TO PRODUCE A WIND THREAT...AND THE MORE VIGOROUS
CELLS SHOULD HAVE ENOUGH CAPE IN THE HAIL GROWTH ZONE TO SUPPORT
LARGE HAIL POTENTIAL AS WELL. WHILE SWATS REMAIN HIGH BELIEVE ANY
HEAVY RAIN WILL BE LOCALIZED AND FURTHER EAST WHICH SHOULD HELP
AVOID AGGRAVATING THE HYDRO SITUATION. ENOUGH INGREDIENTS FOR A BUSY
AFTERNOON ON RADAR.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 214 PM EDT MONDAY...
UPPER TROUGH WILL BE SITUATED RIGHT OVER THE AREA TUESDAY NIGHT WITH
NEXT SFC FRONT WORKING ACROSS BY WEDNESDAY...THOUGH WITH MORE WNW
FLOW ALOFT AND LACK OF SOUTHERLY INFLOW AHEAD OF THIS
SYSTEM...MOISTURE WILL BE LIMITED. AS SUCH HAVE LIMITED CHANCE POPS
OVER THE MOUNTAINS WITH SOME CHANCE INTO THE NE PIEDMONT OF
VA...WITH LESS COVERAGE INTO THE NC PIEDMONT...AS WE SHOULD SEE SOME
DOWNSLOPE DRYING AND SHEARING OF THE VERTICAL DEVELOPMENT. JUST
ENOUGH INSTABILITY WITH COLDER AIR ALOFT TO MENTION THUNDER IN THE
AFTERNOON WEDNESDAY. SHOULD BE A BREEZY DAY WITH HIGHS FROM THE
UPPER 50S OVER SE WV TO LOWER 70S SOUTHEAST.
WEDNESDAY NIGHT THROUGH THURSDAY WILL BE MAINLY DRY WITH CONTINUED
UPPER TROUGH SLIDING ACROSS THE AREA...BUT AXIS SHIFTING MORE OVER
THE COAST. NW FLOW MAY KEEP SHOWERS GOING INTO THE MOUNTAINS WED
EVENING. UPPER RIDGING ARRIVES OVER THE LOWER MS VALLEY WITH SFC
HIGH IN THE TN VALLEY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 130 PM EDT MONDAY...
NOT MUCH CHANGE TO THIS FORECAST. HIGH PRESSURE AT THE SFC BUILDS
SOUTHEAST FROM THE OHIO VALLEY INTO FRIDAY. A SOUTHERN STREAM LOW
ARRIVES OVER THE AR/OK BORDER BY SATURDAY MORNING WITH OVERRUNNING
CLOUDS WORKING INTO THE AREA FRIDAY AHEAD OF A WARM FRONT. BY
SATURDAY ENOUGH MOISTURE TO ALLOW FOR SHOWERS TO FORM BY SATURDAY
MORNING WITH BEST FORCING ACROSS THE CAROLINAS. THIS SYSTEM EXITS BY
SAT NIGHT WITH SUNDAY BEING A DRY AND COOL/MILD DAY WITH HIGHS IN
THE 50S MOUNTAINS TO 60S EAST. HIGH PRESSURE TO ASSUME POSITION OVER
THE OHIO VALLEY INTO THE SRN APPALACHIANS MONDAY TO KEEP THINGS DRY.
NEXT SOUTHERN STREAM SYSTEM MAY WORK SOME SHOWERS OUR WAY BY TUESDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 140 PM EDT MONDAY...
VFR CONDITIONS WILL LOWER THIS AFTERNOON INTO TONIGHT IN
CONVECTION TO MVFR AND IFR AHEAD AND ALONG A COLD FRONT.
SHOWERS AND THUNDERSTORMS WILL DEVELOP QUICKLY WITH THE COLD FRONT
AS IT MOVES EAST ACROSS THE REGION AND EXITS THIS EVENING.
THERE IS SLIGHT TO ENHANCED RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON INTO TONIGHT ESPECIALLY EAST OF THE BLUE RIDGE
MOUNTAINS. ISOLATED GUSTS AROUND 50 KNOT MAY BE POSSIBLE WITH ANY
SEVERE THUNDERSTORM.
PRESSURE RISES BEHIND THE FRONT WILL BRING BREEZY AND GUSTY
WESTERLY WINDS TO THE AREA THIS EVENING INTO TONIGHT. ALSO
THIS EVENING INTO TONIGHT BEHIND THE FRONT...SOME MVFR CEILINGS
ARE POSSIBLE IN THE MOUNTAINS. UNCERTAINTY ON HOW LOW CEILINGS
WILL GET ONCE THE SHOWERS CLEAR OUT TONIGHT. ANOTHER ISSUE IS THAT
ANY LOCATION THAT RECEIVED OVER AN INCH OF RAIN MAY SEE FOG
DEVELOPING OVERNIGHT INTO TUESDAY. VFR CONDITIONS SHOULD RETURN
LATER TONIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING IN BEHIND
THE FRONT WITH A DRIER AIRMASS.
EXTENDED AVIATION...
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY. HIGH PRESSURE
AT THE SURFACE BUILDS SOUTHEAST FROM THE OHIO VALLEY THURSDAY
NIGHT INTO FRIDAY. OVERRUNNING CLOUDS WORKING INTO THE AREA
FRIDAY AHEAD OF A WARM FRONT. BY SATURDAY...ENOUGH MOISTURE TO
ALLOW FOR SHOWERS TO FORM BY SATURDAY MORNING WITH BEST FORCING
ACROSS THE CAROLINAS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...MBS
NEAR TERM...KK/MBS
SHORT TERM...WP
LONG TERM...WP
AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
156 PM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION THIS AFTERNOON INTO
TONIGHT AND BRING SHOWERS AND SOME STRONG THUNDERSTORMS TO THE
REGION. WE WILL THEN SETTLE INTO A COOLER...BREEZY...AND SOMEWHAT
UNSETTLED PATTERN THROUGH THE MIDDLE OF THE WORKWEEK...WITH THE
BEST CHANCE OF MORE SHOWERS AND THUNDERSTORMS ARRIVING WITH
ANOTHER FRONT ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1024 AM EDT MONDAY...
ACTIVE WEATHER DAY WITH LINGERING FLOODING ISSUES FROM SUNDAY TO
SUNDAY NIGHT HEAVY RAINS AND A SEVERE WEATHER THREAT FOR THIS
AFTERNOON INTO TONIGHT WITH COLD FRONT. SWODY1 HAS ADDED AN
ENHANCED POTENTIAL (30 PERCENT) TO SLIGHT RISK WHICH COVERS MUCH
OF OUR FORECAST AREA TODAY. THE MAIN THREATS FOR THUNDERSTORMS
PRODUCING DAMAGING WINDS AND LARGE HAIL...ALONG WITH LOCALLY HEAVY
RAIN. MODIFIED MORNING 12Z RNK SOUNDING SUPPORTS CONCERNS WITH
MODIFIED CAPES AROUND 1000 TO 2000 J/KG WITH HEALTHY SHEAR AROUND
40 KNOTS. ADJUSTED TIMING OF POPS CLOSER TO A BLEND OF HRRR AND
WRFRNK-ARW. MODIFIED TEMPERATURES AND DEW POINTS WITH SFC OBS AND
MODEL TRENDS. COLD FRONT PUSHES EAST ACROSS REGION THIS AFTERNOON
INTO THIS EVENING...THEN HIGH PRESSURE BUILDS IN BEHIND FRONT
TUESDAY. MORE CHANGES THIS AFTERNOON...
AS OF 525 AM EDT MONDAY...
THERE ARE LINGERING HYDRO ISSUES EARLY THIS MORNING FOLLOWING THE
WIDESPREAD HEAVY RAIN FROM SUNDAY AND SUNDAY NIGHT...AND SEVERAL
FLOOD WARNINGS REMAIN IN EFFECT FROM THE NORTH CAROLINA MOUNTAINS
THROUGH THE GRAYSON HIGHLANDS AND INTO SOUTHWEST VIRGINIA UNTIL
AROUND 9AM. THE SITUATION WILL CONTINUED TO BE MONITORED WITH
ADJUSTMENTS MADE ACCORDINGLY.
THE NEXT CONCERN IS THE APPROACHING COLD FRONT SET TO CROSS THE
AREA THIS AFTERNOON. MESO MODELS DISSIPATE THE CONVECTIVE COMPLEX
CURRENTLY APPROACHING FROM THE WEST WITH REDEVELOPMENT FIRING
LATER THIS MORNING INTO THIS AFTERNOON ACROSS THE REGION...
ESPECIALLY FRONT HE BLUE RIDGE EAST. EARLY MORNING SATELLITE PICS
SHOW BREAKS IN THE CLOUD COVER AND WITH 850MB TEMPS AROUND 12C WE
SHOULD SEE SURFACE TEMPERATURES RISE WELL INTO THE 70S TODAY. THIS
WILL GENERATE CAPE VALUES OF 1000J/KG TO 1500J/KG WHICH WILL BE
ENOUGH TO SUPPORT VIGOROUS CONVECTION. LOW LEVEL WINDS WILL GIVE
US 0/6KM BULK SHEAR VALUES OF 40KTS TO 50KTS WITH A SOMEWHAT
LINEAR HODOGRAPH. THUS THERE IS ENOUGH INSTABILITY AND SHEAR
PRESENT FOR A SEVERE THREAT...AND THE SPC SLIGHT RISK LOOKS TO BE
ON TARGET. WILL BE ANTICIPATING STORM CLUSTERS EVOLVING INTO
LINEAR ELEMENTS TO PRODUCE A WIND THREAT...AND THE MORE VIGOROUS
CELLS SHOULD HAVE ENOUGH CAPE IN THE HAIL GROWTH ZONE TO SUPPORT
LARGE HAIL POTENTIAL AS WELL. WHILE SWATS REMAIN HIGH BELIEVE ANY
HEAVY RAIN WILL BE LOCALIZED AND FURTHER EAST WHICH SHOULD HELP
AVOID AGGRAVATING THE HYDRO SITUATION. ENOUGH INGREDIENTS FOR A BUSY
AFTERNOON ON RADAR.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 525 AM EDT MONDAY...
BEHIND THE FRONT WE START TO SETTLE INTO A COOLER...BREEZY...AND
SOMEWHAT UNSETTLED PATTERN AS A BROAD CLOSED LOW TAKES UP
RESIDENCE OVER THE GREAT LAKES. THE FRONT WILL PUSH OFF TO OUR
EAST EARLY TONIGHT AND TAKE THE SHOWERS AND THUNDERSTORMS WITH
IT...LEAVING SOME UPSLOPE SHOWERS ACROSS THE FAR WEST FOR THE
OVERNIGHT. ANY LINGERING PRECIPITATION WILL DISSIPATE EARLY
TUESDAY MORNING AND TUESDAY LOOKS TO BE MOSTLY DRY. COULD SEE THE
OUTSIDE POSSIBILITY OF COOKING UP SOME SHOWERS ON TUESDAY
AFTERNOON BUT BELIEVE THE POPS ARE TOO SMALL TO MENTION SO WILL
KEEP THINGS UNDER 15 PERCENT. ANOTHER FRONT WILL ROTATE THROUGH
THE REGION ON WEDNESDAY AND WILL HAVE SOME SLIGHT INSTABILITY AND
STEEP LAPSE RATES TO WARRANT A MENTION OF THUNDER. WEAK HIGH
PRESSURE WILL THEN BUILD IN WEDNESDAY NIGHT AND BRING WHAT LOOKS
TO BE MOSTLY DRY WEATHER FOR THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...
BROAD UPPER TROUGH REMAINS IN PLACE AND DOMINATES THE EXTENDED
FORECAST...GRADUALLY SHIFTING FURTHER ESE LATE IN THE PERIOD.
THIS KEEPS THE REGION IN AN UNSTABLE/UNSETTLED NORTHWEST FLOW WITH
NUMEROUS EMBEDDED SHORT WAVES. MODELS VARY CONSIDERABLY AS TO THE
TIMING AND PLACEMENT OF THESE DISTURBANCES...BUT ENOUGH AGREEMENT
THAT POPS CANNOT BE DROPPED REALLY AT ANY TIME THE OVERALL TREND
IS TO PUSH THE BETTER MOISTURE FURTHER SOUTH OF THE REGION AS THE
WEEK PROGRESSES AND 850MB TEMPS DROP BELOW 0C IN THE NORTHERN
COUNTIES. THE ENTIRE PERIOD SHOULD FEATURE BELOW NORMAL
TEMPERATURES WITH LOW CHC POPS...HIGHEST ACROSS THE MOUNTAINS AND
TOWARD THE SOUTHERN COUNTIES...WITH THE NORTHERN PIEDMONT THE
DRIEST. ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL THROUGHOUT THE
PERIOD...NO REAL CLEAR CONCERN AT THIS POINT FOR FROST/FREEZE
BECAUSE OF CYCLONIC FLOW AND CLOUDS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 140 PM EDT MONDAY...
VFR CONDITIONS WILL LOWER THIS AFTERNOON INTO TONIGHT IN
CONVECTION TO MVFR AND IFR AHEAD AND ALONG A COLD FRONT.
SHOWERS AND THUNDERSTORMS WILL DEVELOP QUICKLY WITH THE COLD FRONT
AS IT MOVES EAST ACROSS THE REGION AND EXITS THIS EVENING.
THERE IS SLIGHT TO ENHANCED RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON INTO TONIGHT ESPECIALLY EAST OF THE BLUE RIDGE
MOUNTAINS. ISOLATED GUSTS AROUND 50 KNOT MAY BE POSSIBLE WITH ANY
SEVERE THUNDERSTORM.
PRESSURE RISES BEHIND THE FRONT WILL BRING BREEZY AND GUSTY
WESTERLY WINDS TO THE AREA THIS EVENING INTO TONIGHT. ALSO
THIS EVENING INTO TONIGHT BEHIND THE FRONT...SOME MVFR CEILINGS
ARE POSSIBLE IN THE MOUNTAINS. UNCERTAINITY ON HOW LOW CEILINGS
WILL GET ONCE THE SHOWERS CLEAR OUT TONIGHT. ANOTHER ISSUE IS
THAT ANY LOCATION THAT RECIEVED OVER AN INCH OF RAIN MAY SEE
FOG DEVELOPING OVERNIGHT INTO TUESDAY. VFR CONDITIONS SHOULD
RETURN LATER TONIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING IN
BEHIND THE FRONT WITH A DRIER AIRMASS.
EXTENDED AVIATION...
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...MBS
NEAR TERM...KK/MBS
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1156 AM CDT MON APR 20 2015
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 400 AM CDT MON APR 20 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF
STRENGTHENING LOW PRESSURE MOVING NORTH OVER SOUTHWEST LOWER
MICHIGAN. COMMA HEAD PRECIP AROUND THE LOW IS NOW SHIFTING
NORTHWEST AND EXTENDS FROM WAUTOMA TO WAUSAUKEE. FARTHER
WEST...MID-LEVEL FRONTOGENESIS IS CREATING A BAND OF RAIN OVER
WESTERN WISCONSIN AHEAD OF AN UPPER TROUGH POSITIONED OVER
SOUTH-CENTRAL CANADA AND THE NORTHERN PLAINS. WINDS SHIFT TO THE
NORTHWEST OVER WESTERN WISCONSIN AND ARE GUSTING INTO THE LOWER 30
KTS. SOME SNOW BEING REPORTED OVER NORTHERN MINNESOTA AS WELL. AS
THE LOW CONTINUES TO LIFT TO THE NORTH AND THE UPPER TROUGH SETTLES
OVER THE GREAT LAKES...PRECIP TRENDS ARE THE MAIN FORECAST CONCERN.
TODAY...THE LOW PRESSURE SYSTEM WILL TRAVEL NORTHWARD OVER WESTERN
LOWER MICHIGAN INTO NORTHERN ONTARIO. MODELS INDICATE THAT COMMA
HEAD PRECIP ASSOCIATED WITH THE LOW WILL LIFT NORTH ACROSS THE
CENTRAL FORECAST AREA EARLY THIS MORNING AND ACROSS THE CENTRAL UPPER
PENINSULA LATER IN THE MORNING. MEANWHILE...THE FGEN INDUCED RAIN
BAND WILL PIVOT NORTHEAST ACROSS CENTRAL AND NORTH-CENTRAL WISCONSIN
THIS MORNING AND NORTHEAST WISCONSIN THIS AFTERNOON. THEREFORE
EXPECT PERIODS OF RAIN THROUGH THE MORNING...BEFORE THE RAIN
GRADUALLY EXITS TO THE NORTHEAST IN THE AFTERNOON.
ADDITIONALLY...WEST WINDS WILL DRIVE COLDER AIR ACROSS THE STATE
BEHIND THE SYSTEM WHICH WILL STEEPEN LOW LEVEL LAPSE RATES...AND
PROMOTE GUSTY WINDS DEVELOPING. SOME GUSTS OVER CENTRAL AND
EAST-CENTRAL WISCONSIN COULD EXCEED 30 MPH THIS AFTERNOON. WITH THE
RAIN AND CLOUDS...COOLER HIGHS IN THE MID 40S TO AROUND 50.
TONIGHT...MID-LEVEL DRY SLOTTING WILL BE ROTATING OVERHEAD DURING
THE EVENING BEFORE DEEPER MOISTURE RETURNS AS UPPER LEVEL LOW
PRESSURE SETTLES ACROSS THE REGION. MOISTURE WILL BE THE DEEPEST
OVER FAR NORTH-CENTRAL WISCONSIN FOR THE EVENING HOURS...WHERE WILL
CARRY LOW CHANCES OF PRECIP. THEN PRECIP CHANCES WILL INCREASE FROM
NORTHWEST TO SOUTHEAST THROUGH THE OVERNIGHT. SOUNDINGS COOL ENOUGH
OVERNIGHT FOR SNOW TO BECOME THE DOMINANT PTYPE OVER CENTRAL AND
NORTH-CENTRAL WISCONSIN FOR MINOR ACCUMULATIONS ON GRASSY SURFACES.
LOWS RANGING FROM THE LOW TO MID 30S.
TUESDAY...WITH UPPER LEVEL LOW PRESSURE OVERHEAD...PERIODS OF RAIN
AND SNOW SHOWERS LOOK TO OCCUR OVER NORTH-CENTRAL WISCONSIN. MINOR
SNOW ACCUMULATIONS ARE POSSIBLE ACROSS THE NORTH DURING THE
MORNING. CHANCES OF PRECIP WILL IMPROVE THROUGH THE MORNING OVER
EASTERN WISCONSIN WHERE PRECIP COULD BE A MIX OF RAIN AND SNOW
INITIALLY BEFORE TEMPS RISE WARM ENOUGH FOR ALL RAIN. COOL WITH
HIGHS RANGING FROM NEAR 40 NORTH TO THE UPPER 40S SOUTHEAST.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 400 AM CDT MON APR 20 2015
UPPER LOW ACROSS ONTARIO WILL GRADUALLY SHIFT EAST INTO QUEBEC BY
THE END OF THE WORK WEEK. COOL CYCLONIC FLOW WILL CONTINUE TO BRING
BELOW NORMAL TEMPERATURES INTO THE WEEKEND...ALONG WITH A CHANCE OF
RAIN OR SNOW SHOWERS AT TIMES TUESDAY NIGHT INTO THURSDAY. HIGHEST
CHANCES WILL BE ACROSS THE NORTH...IN CLOSER PROXIMITY TO THE UPPER
LOW AND SHORTWAVE ENERGY. CURRENT FORECAST IS DRY FOR FRIDAY...
BUT COULD NOT RULE OUT A STRAY RAIN/SNOW SHOWER ACROSS THE NORTH.
DRY CONDITIONS ARE EXPECTED THIS WEEKEND AS HIGH PRESSURE DOMINATES
THE WEATHER PATTERN. ONLY MINOR CHANGES MADE TO MAX/MIN TEMPERATURES
AND PRECIPITATION CHANCES.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1144 AM CDT MON APR 20 2015
ANY LINGERING RAIN WITH IFR TO MVFR CIGS WILL END EARLY THIS
AFTERNOON HOURS AS A LOW PRESSURE SYSTEM EXIT THE REGION. A
BRIEF PERIOD OF VFR CONDITIONS SHOULD DEVELOP LATE THIS AFTERNOON
BEFORE AN UPPER LEVEL LOW SETTLES OVER THE REGION THIS
EVENING...BRINGING WITH IT MORE MVFR CIGS AND SHOWERY ACTIVITY. IN
NORTH CENTRAL WISCONSIN...PRECIP IS POSSIBLE STARTING AFTER
MIDNIGHT...WITH LIGHT SNOW EXPECTED THROUGH EARLY TUESDAY MORNING
BEFORE CHANGING OVER TO RAIN. THE WORST CONDITIONS WITH MODERATE
SNOW POSSIBLE AND OCCASIONAL IFR CONDITIONS SHOULD REMAIN IN
NORTHERN WISCONSIN...WITH MVFR EXPECTED ELSEWHERE BASED ON
UPSTREAM OBS WHERE TONIGHTS WEATHER IS CURRENTLY LOCATED. IN
EASTERN WISCONSIN...PRECIP SHOULD NOT DEVELOP UNTIL CLOSER TO
TUESDAY MORNING...WITH RAIN AND MVFR CONDITIONS PREVAILING.
GUSTY WNW WIND WILL DIMINISH SLIGHTLY OVERNIGHT BEFORE ANOTHER
ROUND OF GUSTY WEST WINDS IS EXPECTED FOR TUESDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......ALLEN