Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/23/15
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
138 PM PDT TUE APR 21 2015
.SYNOPSIS...
A COUPLE UPPER LEVEL DISTURBANCES MOVING THROUGH THE REGION TODAY
THROUGH THURSDAY...IN ADDITION TO AN UNSTABLE ATMOSPHERE...WILL
RESULT IN THE CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY DURING
THE AFTERNOON AND EARLY EVENING HOURS EACH DAY OVER THE MOUNTAIN AND
DESERT AREAS. BEST CHANCES AND MOST WIDESPREAD SHOWER ACTIVITY
EXPECTED ON THURSDAY...WHEN SCATTERED SHOWERS AND POSSIBLE
THUNDERSTORMS MAY OCCUR OVER THE COAST AND VALLEY AREAS AS WELL. A
THIRD DISTURBANCE MOVING THROUGH ON FRIDAY COULD BRING SOME LIGHT
SHOWERS MAINLY TO AREAS OVER AND WEST OF THE MOUNTAINS. NIGHT AND
MORNING STRATUS WILL PERSIST OVER THE COAST...VALLEY AND COASTAL
SLOPE AREAS...WITH ONLY PARTIAL CLEARING AT BEST DURING THE DAY-TIME
HOURS. DAY-TIME HIGH TEMPERATURES WILL FALL TO SEVERAL DEGREES BELOW
NORMAL. ONSHORE FLOW WILL RESULT IN CONTINUED GUSTY WEST WINDS IN
THE MOUNTAINS AND DESERTS. INCREASING HIGH PRESSURE ALOFT SATURDAY
THROUGH MONDAY WILL BRING WARMING...DRYING CONDITIONS...AND A
SHALLOW MARINE LAYER.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA
INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN
SAN BERNARDINO COUNTIES...
VISIBLE SATELLITE INDICATES THAT MARINE LAYER STRATUS HAS NOT
CLEARED OUT OF MOST COAST/VALLEY/COASTAL SLOPE AREAS THIS AFTERNOON.
12Z MIRAMAR SOUNDING SHOWS A MARINE LAYER INVERSION AT 4000 FEET.
VISIBLE SATELLITE ALSO SHOWS SOME TOWERING CUMULUS/CUMULONIMBUS
OVER THE RIVERSIDE AND SAN BERNARDINO COUNTY MOUNTAINS...AND THE
HIGH DESERTS...WITH RADAR SHOWING SOME LIGHT SHOWERS IN THESE AREAS.
RADAR WAS A LITTLE MORE ACTIVE IN THE LATE MORNING HOURS...WITH
NUMEROUS LIGHTNING STRIKES OVER THE BIG BEAR LAKE AREA...AND SOME
OVER THE RIVERSIDE MOUNTAINS AND COACHELLA VALLEY. THERE WAS ALSO A
REPORT OF PEA SIZE HAIL IN BIG BEAR. THE SHOWERS AND THUNDERSTORMS
WERE THE RESULT OF A VORTICITY MAX MOVING UP FROM THE SOUTH AROUND
THE UPPER LOW CIRCULATION. HOWEVER...BARELY ANY MEASURABLE RAIN WAS
REPORTED FROM THESE SHOWERS AND THUNDERSTORMS...WITH ONLY SOME 0.01
TO 0.02 INCH REPORTS.
ACCORDING TO THE NAM12...THERE IS A SLIGHT INFLUX OF MID-LEVEL
MOISTURE THAT OCCURS THIS AFTERNOON OVER WESTERN RIVERSIDE AND
SOUTHWEST SAN BERNARDINO COUNTIES...WITH SURFACE BASED CAPE
INCREASING TO 400-600 J/KG...LIFTED INDEX OF -2 TO -5 DEG C...MOVING
THROUGH THESE AREAS AS THE UPPER LOW SITS OVER EXTREME SOUTHWEST
CALIFORNIA. SURFACE HEATING MAY BE LIMITED OVER THE HIGH DESERTS AND
SAN BERNARDINO MOUNTAINS DUE TO THE CLOUDY CONDITIONS IN THAT AREA
AT THE MOMENT. THUS...THE RIVERSIDE AND SAN DIEGO COUNTY MOUNTAINS
AND DESERTS MAY BE MORE FAVORED FOR AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS...AND THE 19Z HRRR DEPICTS THIS WELL. CHANCES FOR
SHOWERS DIMINISH OVERNIGHT AS INSTABILITY FROM DAY-TIME SURFACE
HEATING SHUTS OFF.
FOR WEDNESDAY...ANOTHER...DEEPER TROUGH DEVELOPS OVER THE
REGION...WITH SOME ADDITIONAL MID-LEVEL MOISTURE ADVECTION UNDER
SOUTHWEST FLOW. DYNAMICS LOOK WEAKER...WITH NOT A LOT OF PVA...
UPPER LEVEL DIVERGENCE OR LOW LEVEL CONVERGENCE OF WINDS INDICATED.
INSTABILITY ALSO APPEARS TO BE A LITTLE LESS...WITH SURFACE BASED
CAPE OF 100-500 J/KG AND LIFTED INDEX OF -1 TO -3 DEG C.
HOWEVER...WITH THE DAY-TIME HEATING...SOME SHOWERS AND THUNDERSTORMS
COULD DEVELOP OVER THE MOUNTAINS AND PORTIONS OF THE DESERTS DURING
THE AFTERNOON AND EARLY EVENING HOURS. THE HI-RES MODELS DO SHOW
MOUNTAIN AND HIGH DESERT CONVECTION BEING GENERATED GENERALLY IN THE
SAME LOCATIONS AS TODAY...AND THE WEDNESDAY POPS REFLECT THAT.
ON THURSDAY...THE TROUGH AXIS MOVES INLAND...BRINGING DEEPER
MOISTURE THAN TUESDAY/WEDNESDAY...SLIGHTLY COLDER AIR ALOFT...AND A
CONTINUED UNSTABLE ATMOSPHERE. DYNAMICS APPEAR TO BE STRONGER AS
WELL...WITH BETTER PVA AND UPPER LEVEL DIVERGENCE INDICATED. HIGH-
RES MODELS...PARTICULARLY THE CANSAC-WRF AND LOCAL WRF...SHOW THE
MOST WIDESPREAD SHOWERS AND THUNDERSTORMS OCCURRING ON THIS DAY AS
OPPOSED TO TUESDAY/WEDNESDAY. AS THE TROUGH MOVES INLAND...THE LOW-
LEVEL MOIST LAYER LOOKS TO DEEPEN TO NEAR 7000-10000
FEET...WHICH...IN ADDITION TO THE DYNAMICS...COULD PRODUCE SCATTERED
SHOWERS AND POSSIBLE THUNDERSTORMS OVER THE COAST AND VALLEY AREAS.
FOR TODAY THROUGH THURSDAY...SNOW LEVELS LOOK TO BE AROUND 7000-8000
FEET...WITH A COUPLE INCHES OF SNOW POSSIBLE ABOVE THAT ELEVATION.
OVERALL RAINFALL AMOUNTS WILL BE LIGHT...EXCEPT UNDERNEATH ANY HEAVY
SHOWERS OR THUNDERSTORMS. SINCE WINDS ALOFT WILL GENERALLY BE
WEAK...THE SHOWERS AND THUNDERSTORMS WILL LIKELY BE SLOW
MOVING...AND SOME LOCALIZED MINOR FLOODING COULD OCCUR. AS FAR AS
THE MARINE LAYER GOES...STRATUS WILL CONTINUE TO BE VERY DEEP...WITH
NIGHT AND MORNING STRATUS MOVING DEEP INTO THE VALLEYS AND THE
COASTAL SLOPES...AND ONLY PARTIAL CLEARING AT BEST DURING THE DAYS.
ONSHORE FLOW AT THE SURFACE WILL RESULT IN GUSTY WEST WINDS IN THE
MOUNTAINS AND DESERTS EACH DAY...STRONGEST ON THURSDAY WITH LOCAL
GUSTS TO 55 MPH POSSIBLE THAT DAY. FINALLY...DAY-TIME HIGH
TEMPERATURES WILL FALL TO 5-10 DEGREES BELOW NORMAL...AND LOCALLY 15
DEGREES BELOW NORMAL.
THE TROUGH MOVES OFF TO THE EAST LATE THURSDAY NIGHT...WITH
DIMINISHING SHOWER CHANCES GOING INTO FRIDAY MORNING. HOWEVER...SOME
SHOWERS MAY CONTINUE TO OCCUR DURING THE DAY FRIDAY AS A NEW SHORT-
WAVE TROUGH MOVES THROUGH. THESE SHOWERS ARE MOST LIKELY TO DEVELOP
WITHIN THE LOW-LEVEL MOIST LAYER OVER AND WEST OF THE MOUNTAINS. A
LACK OF INSTABILITY WILL LIKELY NOT RESULT IN THUNDERSTORMS ON THIS
DAY. ANY PRECIP AMOUNTS WILL BE FAIRLY LIGHT.
SATURDAY INTO NEXT MONDAY...HIGH PRESSURE WILL GRADUALLY DEVELOP
OVER THE REGION...RESULTING IN WARMER...DRIER WEATHER. ONSHORE FLOW
WILL CONTINUE FOR THE MOST PART...WITH A SHALLOW MARINE LAYER. DAY-
TIME HIGHS LIKELY TO REACH ABOVE NORMAL BY MONDAY.
&&
.AVIATION...
212000Z...COAST/VALLEYS...SCT/BKN LOW CLOUDS...WITH BASES 4000-5000
FEET MSL AND TOPS TO 6000 FEET MSL...WILL CONTINUE THROUGHOUT THE
DAY AND LOCALLY OBSCURE HIGHER TERRAIN AT TIMES. STRATUS WILL
QUICKLY BECOME OVC THIS EVENING FROM THE COAST TO THE COASTAL
MOUNTAIN SLOPES...WITH BASES FROM 3000-4000 FT MSL AND TOPS NEAR
5000 FT MSL. LOW CLOUDS WEDNESDAY WILL SLOWLY BECOME SCT THROUGH
WEDNESDAY AFTN.
MTNS AND DESERTS...CLOUDS OVER MOUNTAIN CRESTS AND HIGH DESERTS
THROUGH THIS EVENING. -SHRA/-TSRA CURRENTLY OVER THE HIGH
DESERTS...WITH DEVELOPMENT POSSIBLE OVER THE MOUNTAIN CRESTS THROUGH
THIS AFTERNOON. STORM BASES ARE NEAR 10 KFT WITH TOPS TO 25 KFT
...AND WILL BE CAPABLE OF PRODUCING GUSTY SFC WINDS AND SMALL HAIL.
SHOWERS WILL END BY 02Z...WITH RESIDUAL HIGHER DEBRIS CLOUDS
OVERNIGHT. ISOLATED AREAS OF BREEZY WEST WINDS THROUGH MTN
PASSES...WITH GUSTS TO 40 KT...WILL BE POSSIBLE TONIGHT.
&&
.MARINE...
130 PM...NO HAZARDOUS MARINE WEATHER IS FORECAST THROUGH SATURDAY.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT ANTICIPATED TODAY. HOWEVER WEATHER
SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...HARRISON
AVIATION/MARINE...JJT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1148 PM MDT MON APR 20 2015
.UPDATE...
ISSUED AT 1139 PM MDT MON APR 20 2015
UPDATED TO ADJUST POPS THROUGH 2 AM. AREAS SOUTH OF HIGHWAY
50 CONTINUE TO SEE ISOLATED TO SCATTERED SHOWERS WHICH SHOULD
DISSIPATE OVER THE NEXT COUPLE OF HOURS. NO OTHER UPDATES AT
THIS TIME. MOZLEY
UPDATE ISSUED AT 553 PM MDT MON APR 20 2015
UPDATED TO ADJUST SHOWER CHANCES ACROSS THE PLAINS...GENERALLY
SOUTH OF HIGHWAY 50 FOR THIS EVENING. MOST HIGH-RES MODELS HAVE
AN AREA OF SHOWER ACTIVITY DROPPING ACROSS THE PLAINS AND MADE
ADJUSTMENTS TO ACCOUNT FOR THIS. NO OTHER UPDATES AT THIS TIME.
MOZLEY
&&
.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 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1112 PM MDT MON APR 20 2015
VFR CONDITIONS EXPECTED AT THE TAF SITES OVER THE NEXT 24 HOURS.
LIGHT WINDS TONIGHT WILL INCREASE OUT OF THE SOUTH TO SOUTHWEST
ON TUESDAY...WITH SPEEDS UNDER 15 KTS. SHOWERS AND ISOLATED
THUNDERSTORMS WILL DEVELOP OVER THE MOUNTAINS TUESDAY
AFTERNOON...A FEW OF WHICH WILL MOVE OFF INTO THE ADJACENT TERRAIN
POTENTIALLY IMPACTING KCOS AND KALS. ALTHOUGH ODDS LOOK FAIRLY
LOW THAT THE TERMINALS WILL BE IMPACTED...PATTERN LOOKS SIMILAR TO
WHAT OCCURRED ON MONDAY...SO WILL CARRY VCSH IN THE TAFS AFTER
20Z FOR BOTH LOCATIONS. KPUB IS LESS LIKELY BE IMPACTED BY ANY
PASSING SHOWERS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MOZLEY
AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1117 PM MDT MON APR 20 2015
.UPDATE...
ISSUED AT 553 PM MDT MON APR 20 2015
UPDATED TO ADJUST SHOWER CHANCES ACROSS THE PLAINS...GENERALLY
SOUTH OF HIGHWAY 50 FOR THIS EVENING. MOST HIGH-RES MODELS HAVE
AN AREA OF SHOWER ACTIVITY DROPPING ACROSS THE PLAINS AND MADE
ADJUSTMENTS TO ACCOUNT FOR THIS. NO OTHER UPDATES AT THIS TIME.
MOZLEY
&&
.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 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1112 PM MDT MON APR 20 2015
VFR CONDITIONS EXPECTED AT THE TAF SITES OVER THE NEXT 24 HOURS.
LIGHT WINDS TONIGHT WILL INCREASE OUT OF THE SOUTH TO SOUTHWEST
ON TUESDAY...WITH SPEEDS UNDER 15 KTS. SHOWERS AND ISOLATED
THUNDERSTORMS WILL DEVELOP OVER THE MOUNTAINS TUESDAY
AFTERNOON...A FEW OF WHICH WILL MOVE OFF INTO THE ADJACENT TERRAIN
POTENTIALLY IMPACTING KCOS AND KALS. ALTHOUGH ODDS LOOK FAIRLY
LOW THAT THE TERMINALS WILL BE IMPACTED...PATTERN LOOKS SIMILAR TO
WHAT OCCURRED ON MONDAY...SO WILL CARRY VCSH IN THE TAFS AFTER
20Z FOR BOTH LOCATIONS. KPUB IS LESS LIKELY BE IMPACTED BY ANY
PASSING SHOWERS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MOZLEY
AVIATION...KT
AREA FORECAST DISCUSSION
NWS TAUNTON MA
404 AM EDT TUE APR 21 2015
.SYNOPSIS...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ALONG WITH MILD
TEMPERATURES THIS MORNING...GIVES WAY TO A DRYING TREND THIS
AFTERNOON. A COLD FRONT WILL BRING SCATTERED SHOWERS...AND PERHAPS
EVEN AN ISOLATED THUNDERSTORM OR TWO...WEDNESDAY AFTERNOON AND
EVENING. UNSEASONABLY COOL WEATHER FOLLOWS THURSDAY THROUGH THIS
WEEKEND WITH JUST A SPOT SHOWER FROM TIME TO TIME.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST RUNS OF THE HRRR LOOK TO HAVE A VERY GOOD HANDLE ON THE
FORECAST FOR THE NEXT SEVERAL HOURS THIS MORNING. LOTS OF ELEVATED
CONVECTION ACROSS THE WESTERN HALF OF SOUTHERN NEW ENGLAND ALREADY
THIS MORNING. SO FAR...THE MAIN HAZARDS HAVE BEEN THE LIGHTNING
AND BRIEFLY TORRENTIAL RAINFALL. THESE STORMS WERE MOVING ALONG AT
35-45 MPH...SO AM NOT OVERLY CONCERNED ABOUT SIGNIFICANT
WIDESPREAD FLOODING AT THIS TIME. SOME POOR DRAINAGE AREAS COULD
EXPERIENCE NUISANCE FLOODING FOR A TIME THIS MORNING. WE WILL
CONTINUE TO MONITOR RAINFALL RATES THOUGH.
EXPECTING RAPID CLEARING BEHIND A WARM FRONT LATER THIS MORNING
WITH TEMPERATURES SOARING INTO THE UPPER 60S TO NEAR 70 MOST
LOCATIONS. WESTERLY WINDS WILL ALLOW EVEN THE COASTAL LOCATIONS TO
GET IN ON THE WARM TEMPERATURES...UNLIKE THIS PAST SATURDAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
A SHORTWAVE WILL BE APPROACHING FROM THE WEST...BRINGING A CHANCE
FOR SOME SHOWERS TO PORTIONS OF WESTERN MA BY DAYBREAK WEDNESDAY.
WITH A COLD FRONT HAVING ALREADY PASSED THROUGH OUR REGION LATE
THIS AFTERNOON...MODELS DO NOT SHOW MUCH RAINFALL AS INSTABILITY
IS RATHER LIMITED. MUCH OF TONIGHT SHOULD REMAIN DRY ACROSS
SOUTHERN NEW ENGLAND WITH SEASONABLE MINIMUM TEMPERATURES.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS WED WITH A LOW RISK OF THUNDER/SMALL HAIL
* SEASONABLY MILD TEMPERATURES WED
* UNSEASONABLY COOL THU-SUN WITH A SPOT SHOWER OR TWO AT TIMES
OVERVIEW...
OVERALL THE 12Z GUIDANCE IS IN GOOD AGREEMENT WITHIN THE MEDIUM AND
LONG RANGE. HOWEVER EXACT TIMING AND STRENGTH OF EACH SYSTEM STILL
NEEDS TO BE WORKED OUT. UPPER LEVEL LOW WILL CONTINUE TO DOMINATE
THE REGION THROUGH THE EXTENDED...PINWHEELING BETWEEN THE GREAT
LAKES AND NEW ENGLAND. THIS SYSTEM WILL YIELD TO A MORE SHOWERY AND
COOLER FORECAST FOR THE REST OF THE WEEK AND INTO THE WEEKEND.
DETAILS...
* WEDNESDAY AND WEDNESDAY NIGHT...MODERATE CONFIDENCE.
STRONG SHORTWAVE WILL MOVE THROUGH THE FLOW ON WEDNESDAY DEVELOPING
A SURFACE LOW ACROSS HUDSON RIVER VALLEY AND INTO SOUTHERN NEW
ENGLAND. THIS LOW WILL BRING SCT RAIN SHOWERS AND ISOLATED THUNDER
TO THE AREA BY THE AFTERNOON HOURS. APPEARS WE MAY TRY TO WARM
SECTOR ALLOWING SURFACE TEMPS TO REACH INTO THE LOW TO MID 60S. THIS
WILL STEEPEN THE LAPSE RATES TO AROUND 7-8 C/KM AS 500 MB TEMPS ARE
-24C. MODEL GUIDANCE IS ALSO INDICATING THAT SOME SURFACE CAPE MAY
DEVELOP WHICH WILL HELP IN THUNDERSTORM DEVELOPMENT. IN FACT WE
COULD SEE SMALL HAIL/GRAUPEL AS FREEZING HEIGHTS WILL BE LOW
THANKS TO THE COLD POOL. STILL A LOT OF DETAILS TO WORK OUT BUT
SOMETHING TO WATCH IN THE COMING DAY.
* THURSDAY INTO MONDAY...MODERATE CONFIDENCE.
STRONG CUT OFF LOW WILL CONTINUE TO SPIN OVER THE NORTHEAST DURING
THIS TIME PERIOD. NEW ENGLAND COULD SEE A SEVERAL WAVES DEVELOP AND
PUSH THROUGH THE REGION. HOWEVER MAY SEE A LOT OF DIURNAL CU AND
DIURNAL SHOWERS DEVELOPING RATHER THAN WIDESPREAD RAIN. THESE
SHOWERS WILL BE DIURNALLY DRIVEN AS COLD POOL ALOFT WILL BE OVERHEAD
STEEPENING THE LAPSE RATES. AREAS THAT HAVE THE BEST CHANCE FOR
ANY PRECIP WILL BE NORTH OF THE PIKE...CLOSER TO THE LOW PRESSURE.
LASTLY EXPECT TEMPS TO BE ABOUT 5-10 F BELOW AVERAGE FOR THE WEEK
THANKS TO THE COOLER TEMPS ALOFT VIA THE COLD POOL. IN FACT SOME
AREAS MAY NOT SEE THE 60S FOR THE REST OF THE WEEK AND INTO THE
WEEKEND.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT-TERM /THROUGH TUESDAY/...
THROUGH 12Z...LINE OF ELEVATED THUNDERSTORMS MOVES INTO THE
CENTRAL AND EASTERN SECTIONS OF SOUTHERN NEW ENGLAND. BRIEF GUSTY
WINDS AND TORRENTIAL RAINFALL ARE THE BIGGEST THREATS.
TODAY...CONDITIONS IMPROVING TO VFR BY MIDDAY. COLD FRONT MOVES
THROUGH WITH WINDS SHIFTING W/SW THIS AFTERNOON.
TONIGHT...HIGH CONFIDENCE IN MAINLY VFR CONDITIONS DESPITE THE
RISK FOR A SPOT SHOWER OR TWO.
KBOS TAF...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN
TIMING. MORNING PUSH LIKELY TO BE AFFECTED. ALSO LOW RISK OF A
THUNDERSTORM BETWEEN 08Z AND 12Z.
KBDL TAF...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN
TIMING. RISK FOR THUNDERSTORMS HAS LIKELY MOVED EAST OF THE
TERMINAL FOR THE REST OF THIS MORNING.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
WED...MODERATE CONFIDENCE. A COLD FRONT WILL BRING A ROUND OF
SCATTERED SHOWERS MAINLY WED AFTERNOON/EARLY EVENING. LOW RISK FOR
EVEN A FEW RUMBLES OF THUNDER AND PERHAPS SMALL HAIL/GRAUPEL WITH
THE HEAVIEST SHOWERS.
THU/FRI/SAT...HIGH CONFIDENCE. MAINLY VFR. CONDITIONS COULD LOWER TO
MVFR QUICKLY IN A BRIEF DIURNALLY DRIVEN SHOWER OR TWO.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TONIGHT/...
WILL LIKELY BE ABLE TO CONVERT THE REST OF THE GALE WARNINGS FOR
THE OUTER SOUTHERN NEW ENGLAND WATERS TO SMALL CRAFT ADVISORIES.
STILL NEED TO WATCH FOR THUNDERSTORMS THIS MORNING...SOME OF WHICH
COULD PRODUCE BRIEF GUSTS UP TO 35 KT. VISIBILITY IMPROVES LATER
TODAY WITH WINDS AND SEAS CONTINUING TO DIMINISH TONIGHT.
VISIBILITIES MAY BE LIMITED AT TIMES.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
WEDNESDAY...HIGH CONFIDENCE. MODEST WEST TO SOUTHWEST FLOW EXPECTED
AHEAD OF A COLD FRONT...BUT SPEEDS WILL BE NEAR SCA ESP ACROSS THE
NEAR SHORE WATERS. A FEW SHOWERS WED AFTERNOON AND EVENING WITH A
LOW RISK OF AN ISOLATED THUNDERSTORM WITH SMALL HAIL.
THURSDAY THROUGH SATURDAY...HIGH CONFIDENCE. MODEST WESTERLY FLOW
AS A RESULT OF CLOSED LOW PRESSURE ACROSS QUEBEC. ENOUGH COLD
ADVECTION OVER THE WATERS WILL BE PRESENT TO GENERATE PERIODS OF 25
KNOT WIND GUSTS. MARGINAL SCA SEAS EXPECTED ACROSS THE OUTER-WATERS
AT TIMES...BUT WITH GOOD VISIBILITY.
&&
.TIDES/COASTAL FLOODING...
EAST TO SOUTHEAST WINDS WILL INCREASE THROUGH TONIGHT. GUIDANCE
CONTINUES TO TRACK STRONGEST WINDS ACROSS NEW ENGLAND EARLY THIS
EVENING...BEFORE HIGH TIDE OCCURS ALONG THE SOUTH COAST /AROUND
03Z/ AND EAST COAST /ABOUT 06Z/. THIS RESULTS IN WINDS BEGINNING
TO SLACKEN AS HIGH TIDE APPROACHES. ALSO SYSTEM IS FAIRLY
PROGRESSIVE SO DURATION OF ONSHORE WINDS IS LIMITED.
ESTOFS CONTINUES TO BE MORE ROBUST AND REALISTIC THAN ETSS WITH
SURGE VALUES 1.0-1.5 FT AT THE TIME OF HIGH TIDE. SEAS ALSO BUILDING
TO 10-15 FT JUST OFFSHORE. THIS SHOULD BE SUFFICIENT TO GENERATE
AREAS OF MINOR COASTAL FLOODING AND SPLASH OVER. THUS WILL CONTINUE
WITH A COASTAL FLOOD ADVISORY FOR THESE LOCATIONS DURING THIS
EVENING AND EARLY TUE MORNING HIGH TIDES.
WINDS DO NOT LOOK STRONG ENOUGH AT THE TIME OF HIGH TIDE FOR A
MODERATE COASTAL FLOOD EVENT.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR ANZ235-237-
250-254>256.
SMALL CRAFT ADVISORY UNTIL NOON EDT WEDNESDAY FOR ANZ251.
&&
$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...DUNTEN
AVIATION...BELK/DUNTEN
MARINE...BELK/DUNTEN
TIDES/COASTAL FLOODING...STAFF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
321 AM EDT TUE APR 21 2015
.SYNOPSIS...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ALONG WITH MILD
TEMPERATURES THIS MORNING...GIVES WAY TO A DRYING TREND THIS
AFTERNOON. A COLD FRONT WILL BRING SCATTERED SHOWERS...AND PERHAPS
EVEN AN ISOLATED THUNDERSTORM OR TWO...WEDNESDAY AFTERNOON AND
EVENING. UNSEASONABLY COOL WEATHER FOLLOWS THURSDAY THROUGH THIS
WEEKEND WITH JUST A SPOT SHOWER FROM TIME TO TIME.
&&
.NEAR TERM /THROUGH TODAY/...
LATEST RUNS OF THE HRRR LOOK TO HAVE A VERY GOOD HANDLE ON THE
FORECAST FOR THE NEXT SEVERAL HOURS THIS MORNING. LOTS OF ELEVATED
CONVECTION ACROSS THE WESTERN HALF OF SOUTHERN NEW ENGLAND ALREADY
THIS MORNING. SO FAR...THE MAIN HAZARDS HAVE BEEN THE LIGHTNING
AND BRIEFLY TORRENTIAL RAINFALL. THESE STORMS WERE MOVING ALONG AT
35-45 MPH...SO AM NOT OVERLY CONCERNED ABOUT SIGNIFICANT
WIDESPREAD FLOODING AT THIS TIME. SOME POOR DRAINAGE AREAS COULD
EXPERIENCE NUISANCE FLOODING FOR A TIME THIS MORNING. WE WILL
CONTINUE TO MONITOR RAINFALL RATES THOUGH.
EXPECTING RAPID CLEARING BEHIND A WARM FRONT LATER THIS MORNING
WITH TEMPERATURES SOARING INTO THE UPPER 60S TO NEAR 70 MOST
LOCATIONS. WESTERLY WINDS WILL ALLOW EVEN THE COASTAL LOCATIONS TO
GET IN ON THE WARM TEMPERATURES...UNLIKE THIS PAST SATURDAY.
&&
.SHORT TERM /TONIGHT/...
A SHORTWAVE WILL BE APPROACHING FROM THE WEST...BRINGING A CHANCE
FOR SOME SHOWERS TO PORTIONS OF WESTERN MA BY DAYBREAK WEDNESDAY.
WITH A COLD FRONT HAVING ALREADY PASSED THROUGH OUR REGION LATE
THIS AFTERNOON...MODELS DO NOT SHOW MUCH RAINFALL AS INSTABILITY
IS RATHER LIMITED. MUCH OF TONIGHT SHOULD REMAIN DRY ACROSS
SOUTHERN NEW ENGLAND WITH SEASONABLE MINIMUM TEMPERATURES.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS WED WITH A LOW RISK OF THUNDER/SMALL HAIL
* SEASONABLY MILD TEMPERATURES WED
* UNSEASONABLY COOL THU-SUN WITH A SPOT SHOWER OR TWO AT TIMES
DETAILS...
WEDNESDAY AND WEDNESDAY NIGHT...
A FAIRLY STRONG SHORTWAVE AND ASSOCIATED COLD FRONT WILL CROSS THE
REGION WED AFTERNOON AND EVENING. HIGH TEMPS SHOULD STILL REACH
INTO INTO THE UPPER 50S TO MIDDLE 60S AHEAD OF THE FRONT. WE WILL
SEE SCATTERED SHOWERS WITH THE FRONT GIVEN DECENT FORCING AND SOME
MARGINAL INSTABILITY. MOST LIKELY TIME FRAME IS WED AFTERNOON AND
EARLY EVENING. ITS QUITE COLD ALOFT AND MID LEVEL LAPSE RATES ARE
VERY IMPRESSIVE AROUND 8C/KM! IF WE CAN MUSTER A FEW HUNDRED J/KG
OF CAPE...MAY EVEN SEE AN EMBEDDED THUNDERSTORM OR TWO. CONFIDENCE
ON THUNDER IS LOW AT THIS POINT...BUT GIVEN COLD POOL ALOFT THERE IS
AT LEAST THIS RISK FOR SOME GRAUPEL/SMALL HAIL AND PERHAPS EVEN
GUSTY WINDS IN THE HEAVIEST SHOWERS. THIS ACTIVITY SHOULD WIND DOWN
BY WED EVENING.
THURSDAY THROUGH MONDAY...
ANOMALOUS CLOSED UPPER LEVEL LOW SETS UP ACROSS NORTHERN NEW ENGLAND
AND INTO QUEBEC. THE RESULT WILL BE BELOW NORMAL HEIGHTS AND COOLER
THAN NORMAL TEMPS IN SOUTHERN NEW ENGLAND. OVERALL...HIGH TEMPS
WILL RANGE FROM THE UPPER 40S TO MIDDLE 50S MUCH OF THE TIME BUT
SOME MODERATION IS POSSIBLE BY MONDAY. AS FOR PRECIP CHANCES...THE
VAST MAJORITY OF THE TIME SHOULD FEATURE DRY WEATHER.
HOWEVER...GIVEN COLD POOL ALOFT A FEW SPOT SHOWERS WILL BE POSSIBLE
AT TIMES...ESPECIALLY IN NORTHERN SECTIONS DURING THE AFTERNOON
HOURS. LOW RISK FOR EVEN A FEW WET SNOW FLAKES TO MIX IN FOR
A TIME ACROSS THE HIGHER TERRAIN...BUT WOULD BE OF NO IMPACT.
THERE IS ONE FLY IN THE OINTMENT. WE WILL HAVE TO WATCH A MORE
SIGNIFICANT LOW PRESSURE SYSTEM SAT NIGHT/SUN. MOST OF THE MODEL
GUIDANCE KEEPS THAT SYSTEM WELL TO OUR SOUTH. THE 12Z ECMWF IS A
BIT CLOSER THEN THE REST OF THE GUIDANCE...BUT EVEN THAT WOULD KEEP
US DRY. AGAIN...ODDS STRONGLY FAVOR KEEPING THIS SYSTEM SOUTH OR
OUR REGION GIVEN ANOMALOUS CLOSED LOW SITTING JUST TO OUR NORTH.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT-TERM /THROUGH TUESDAY/...
THROUGH 12Z...LINE OF ELEVATED THUNDERSTORMS MOVES INTO THE
CENTRAL AND EASTERN SECTIONS OF SOUTHERN NEW ENGLAND. BRIEF GUSTY
WINDS AND TORRENTIAL RAINFALL ARE THE BIGGEST THREATS.
TODAY...CONDITIONS IMPROVING TO VFR BY MIDDAY. COLD FRONT MOVES
THROUGH WITH WINDS SHIFTING W/SW THIS AFTERNOON.
TONIGHT...HIGH CONFIDENCE IN MAINLY VFR CONDITIONS DESPITE THE
RISK FOR A SPOT SHOWER OR TWO.
KBOS TAF...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN
TIMING. MORNING PUSH LIKELY TO BE AFFECTED. ALSO LOW RISK OF A
THUNDERSTORM BETWEEN 08Z AND 12Z.
KBDL TAF...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN
TIMING. RISK FOR THUNDERSTORMS HAS LIKELY MOVED EAST OF THE
TERMINAL FOR THE REST OF THIS MORNING.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
WED...MODERATE CONFIDENCE. A COLD FRONT WILL BRING A ROUND OF
SCATTERED SHOWERS MAINLY WED AFTERNOON/EARLY EVENING. LOW RISK FOR
EVEN A FEW RUMBLES OF THUNDER AND PERHAPS SMALL HAIL/GRAUPEL WITH
THE HEAVIEST SHOWERS.
THU/FRI/SAT...HIGH CONFIDENCE. MAINLY VFR DESPITE THE RISK FOR A
BRIEF DIURNALLY DRIVEN SHOWER OR TWO.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TONIGHT/...
WILL LIKELY BE ABLE TO CONVERT THE REST OF THE GALE WARNINGS FOR
THE OUTER SOUTHERN NEW ENGLAND WATERS TO SMALL CRAFT ADVISORIES.
STILL NEED TO WATCH FOR THUNDERSTORMS THIS MORNING...SOME OF WHICH
COULD PRODUCE BRIEF GUSTS UP TO 35 KT. VISIBILITY IMPROVES LATER
TODAY WITH WINDS AND SEAS CONTINUING TO DIMINISH TONIGHT.
VISIBILITIES MAY BE LIMITED AT TIMES.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
WEDNESDAY...HIGH CONFIDENCE. MODEST WEST TO SOUTHWEST FLOW
EXPECTED AHEAD OF A COLD FRONT...BUT SPEEDS SHOULD REMAIN BELOW
SMALL CRAFT THRESHOLDS. A FEW SHOWERS WED AFTERNOON AND EVENING
WITH A LOW RISK OF AN ISOLATED THUNDERSTORM WITH SMALL HAIL.
THURSDAY THROUGH SATURDAY...HIGH CONFIDENCE. MODEST WESTERLY FLOW AS
A RESULT OF CLOSED LOW PRESSURE ACROSS QUEBEC. ENOUGH COLD
ADVECTION OVER THE WATERS WILL BE PRESENT TO GENERATE PERIODS OF 25
KNOT WIND GUSTS. MARGINAL SCA SEAS EXPECTED ACROSS THE OUTER-WATERS
AT TIMES...BUT WITH GOOD VISIBILITY.
&&
.TIDES/COASTAL FLOODING...
EAST TO SOUTHEAST WINDS WILL INCREASE THROUGH TONIGHT. GUIDANCE
CONTINUES TO TRACK STRONGEST WINDS ACROSS NEW ENGLAND EARLY THIS
EVENING...BEFORE HIGH TIDE OCCURS ALONG THE SOUTH COAST /AROUND
03Z/ AND EAST COAST /ABOUT 06Z/. THIS RESULTS IN WINDS BEGINNING
TO SLACKEN AS HIGH TIDE APPROACHES. ALSO SYSTEM IS FAIRLY
PROGRESSIVE SO DURATION OF ONSHORE WINDS IS LIMITED.
ESTOFS CONTINUES TO BE MORE ROBUST AND REALISTIC THAN ETSS WITH
SURGE VALUES 1.0-1.5 FT AT THE TIME OF HIGH TIDE. SEAS ALSO BUILDING
TO 10-15 FT JUST OFFSHORE. THIS SHOULD BE SUFFICIENT TO GENERATE
AREAS OF MINOR COASTAL FLOODING AND SPLASH OVER. THUS WILL CONTINUE
WITH A COASTAL FLOOD ADVISORY FOR THESE LOCATIONS DURING THIS
EVENING AND EARLY TUE MORNING HIGH TIDES.
WINDS DO NOT LOOK STRONG ENOUGH AT THE TIME OF HIGH TIDE FOR A
MODERATE COASTAL FLOOD EVENT.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...COASTAL FLOOD ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR
MAZ007-015-016-019-022-024.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT EARLY THIS MORNING FOR
ANZ231>234.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR
ANZ230-236.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ235-237-
251.
GALE WARNING UNTIL 4 AM EDT EARLY THIS MORNING FOR ANZ250-
254>256.
&&
$$
SYNOPSIS...BELK/FRANK
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...FRANK
AVIATION...BELK/FRANK
MARINE...BELK/FRANK
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS ALBANY NY
1252 AM EDT TUE APR 21 2015
.SYNOPSIS...
.A LOW PRESSURE SYSTEM APPROACHING FROM THE WEST WITH ASSOCIATED
FRONTS WILL BRING OCCASIONAL SHOWERS TO THE AREA ALONG WITH A FEW
RUMBLES OF THUNDER TONIGHT. WITH A LARGE STATIONARY LOW OVER THE
REGION...UNSETTLED WEATHER WILL CONTINUE THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1245 AM EDT...A LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS
HAS NOW ENTERED WESTERN PORTIONS OF THE FORECAST AREA...EXTENDING
FROM THE WESTERN ADIRONDACKS SOUTH INTO THE WESTERN MOHAWK
VALLEY...SCHOHARIE VALLEY...AND INTO THE EASTERN CATSKILLS.
ADDITIONAL SHOWERS AND THUNDERSTORMS HAVE FORMED AHEAD OF THIS
LINE ACROSS THE MID HUDSON VALLEY AND SE CATSKILLS...AND ARE
TRANSLATING NORTH/NORTHEAST. WE EXPECT SHOWERS AND THUNDERSTORMS
TO CONTINUE EXPANDING EAST/NORTHEAST OVER THE NEXT 2-4 HOURS. SOME
THUNDERSTORMS COULD CONTAIN LOCALLY HVY DOWNPOURS...AND ISOLATED
GUSTY WINDS. IN ADDITION...SOME SMALL HAIL IS POSSIBLE WITHIN THE
TALLER CONVECTIVE ELEMENTS...AS WE HAD ONE SPOTTER FROM HIGHLAND
NY IN ULSTER CO REPORT PEA SIZE HAIL WITH ONE CELL.
THIS AREA OF SHOWERS AND THUNDERSTORMS APPEARS TO BE IN
ASSOCIATION WITH THE APPROACH OF AN OCCLUDED FRONT FROM THE
WEST...AND ALSO AIDED BY THE PASSAGE OF AN UPPER LEVEL JET CORE
OFF THE NORTHERN MID ATLANTIC COAST...PLACING OUR REGION WITHIN
ITS LEFT EXIT REGION.
A POTENT VORT LOBE CURRENTLY TRANSLATING EAST/NORTHEAST THROUGH
THE LOWER OH AND TN VALLEYS WILL ROUND THE EAST SIDE OF THE UPPER
LEVEL TROUGH AND APPROACH TOWARD DAYBREAK. THIS SHOULD ALLOW
SHOWERS TO PERSIST THROUGH DAYBREAK...WITH PERHAPS A FEW PERIODS
OF STEADY...MODERATE RAIN AT TIMES.
TEMPS WILL HOLD NEARLY STEADY...OR PERHAPS RISE A BIT IN SOME
AREAS BEFORE FALLING SEVERAL DEGREES AGAIN CLOSER TO
DAYBREAK...WITH MAINLY 40S EXPECTED FOR LOWS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
DURING THE DAY ON TUESDAY WE CAN EXPECT SOME LINGERING SHOWERS
DURING THE DAY WITH SOME BREAKS OF SUN POSSIBLE IN THE AFTERNOON.
THE UPPER LEVEL TROUGH AXIS WILL BE PASSING THROUGH THE AREA WITH
AN ASSOCIATED VORT MAX. HIGH TEMPS ON TUESDAY ARE EXPECTED MAX
TEMPS ARE FORECAST TO REACH THE LOWER/MID 60S IN VALLEY AREAS AND
50S ACROSS HIGHER ELEVATIONS.
FOR TUESDAY NIGHT AND WEDNESDAY...A SECONDARY TROUGH IS EXPECTED
TO MOVE FROM THE MIDWEST THROUGH CENTRAL NEW YORK AND CENTRAL
PENNSYLVANIA BRINGING ANOTHER ROUND OF SHOWERS AND THIS WILL BE
FOLLOWED BY YET ANOTHER TROUGH OF LOW PRESSURE ON WEDNESDAY. THIS
IS ALL OCCURRING AT THE SURFACE WHILE ALOFT AN UPPER LEVEL CLOSED
LOW SITS AND SPINS JUST NORTH OF THE UPPER GREAT LAKES SENDING
PIECES OF ENERGY IN THE FORM OF VORT LOBES ACROSS OUR FA DURING
MUCH OF THE PERIOD. EXPECT LOWS ON TUESDAY NIGHT ARE EXPECTED TO
RANGE FROM THE UPPER 20S NORTHWEST TO AROUND 40 SOUTHEAST. SOME
LIGHT SNOW ACCUMULATIONS GENERALLY UNDER AN INCH ARE POSSIBLE
ACROSS THE WESTERN ADIRONDACKS. HIGHS ON WEDNESDAY ARE EXPECTED TO
RANGE FROM THE UPPER 40S NORTHWEST TO AROUND 690 NORTHWEST.
FOR WEDNESDAY NIGHT AND THURSDAY NOT MUCH IMPROVEMENT IS EXPECTED
AS THE UPPER LEVEL TROUGH AXIS SETTLES ACROSS THE NORTHEAST US
WHILE AT THE SURFACE LOW PRESSURE INTENSIFIES ACROSS THE GULF OF
MAINE WITH YET ANOTHER COLD FRONT EXPECTED TO MOVE INTO THE
EASTERN GREAT LAKES BY THURSDAY. THUS THERE WILL STILL BE
SCATTERED SHOWERS AROUND ALTHOUGH THE PCPN SHOULD BE MAINLY ON THE
LIGHT SIDE. EXPECT LOWS WEDNESDAY NIGHT TO BE IN THE UPPER 20S TO
UPPER 30S WITH ONCE AGAIN A LITTLE LIGHT SNOW POSSIBLE ACROSS THE
WESTERN ADIRONDACKS WITH HIGHS ON THURSDAY IN THE MID 40S TO LOWER
50S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
BELOW NORMAL TEMPERATURES ALONG WITH SOME INTERVALS OF RAIN AND
EVEN SNOW SHOWERS ARE EXPECTED THROUGH THE WEEKEND.
MODEL GUIDANCE REMAINS IN GOOD AGREEMENT INDICATING A LARGE SCALE UPPER
LOW WILL DOMINATE OUR WEATHER. HOWEVER THERE CONTINUES TO BE SOME
DISAGREEMENT ON ITS EXACT TRACK AND WITH THE TIMING OF INDIVIDUAL SHORT
WAVE ROTATING ABOUT IT. THERE IS CONSENSUS THE CENTER OF THE UPPER
LOW SHOULD REMAIN TO OUR NORTH AS IT MOVES ACROSS EASTERN CANADA KEEPING
OUR THE REGION IN WESTERLY FLOW. HAVE FAVORED GUIDANCE FROM THE WEATHER
PREDICTION CENTER TO MAINTAIN FORECAST CONSISTENCY. THE BETTER CHANCES
FOR SCATTERED SHOWERS WILL BE ACROSS THE HIGHER TERRAIN. RAIN SHOWERS
ARE EXPECTED DURING THE DAY...BUT AT NIGHT IT WILL BE COLD ENOUGH FOR
SNOW SHOWER ESPECIALLY ACROSS THE HIGHER ELEVATIONS.
OVERALL EXPECTING HIGHS IN THE 40S AND 50S WITH LOWS IN THE 20S AND 30S.
NORMALS FOR LATE APRIL...
ALBANY NY: HIGHS IN THE LOWER 60S AND LOWS IN THE LOWER 40S.
GLENS FALLS NY: HIGHS IN THE LOWER 60S AND LOWS IN THE UPPER 30S.
POUGHKEEPSIE NY: HIGHS IN THE MID 60S AND LOWS AROUND 40.
BENNINGTON VT: HIGHS IN THE LOWER 60S AND LOWS IN THE UPPER 30S.
PITTSFIELD MA: HIGHS IN THE UPPER 50S AND LOWS IN THE MID 30S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A LOW PRESSURE SYSTEM WILL OCCLUDE AS IT MOVES ACROSS THE REGION
TONIGHT. WE HAVE HAD A BIT OF A LULL IN THE PRECIPITATION THIS
EVENING. HAVE SHOWERS ACTIVITY OCCURRING TO EAST AND CONVECTION TO
OUR WEST IN THE VICINITY OF THE WARM FRONT. THE HRRR SEEMS TO HAVE
A PRETTY GOOD HANDLE ON CONVECTION SO HAVE USED IT AS A GUIDE TO
INCREASE POPS THIS EVENING WITH THE BEST CHANCES AS WE APPROACH
MIDNIGHT AS ANOTHER DISTURBANCE AHEAD THE OCCLUDING FRONTAL
BOUNDARY WILL INCREASE THE THREAT FOR CONVECTION. WE ARE NOT
EXPECTED TO GET INTO THE WARM SECTOR IT GETS PINCHED OFF JUST TO
THE SOUTH OF OUR FORECAST AREA TONIGHT AS THE SYSTEM OCCLUDES.
THE MODELS CONTINUE TO SHOW SOME ELEVATED INSTABILITY WITH
SHOWALTER INDICES BELOW ZERO MOVING ACROSS THE REGION TONIGHT...SO
THERE IS A CHANCE FOR THUNDERSTORMS HOWEVER CONFIDENCE IS TOO LOW
TO INCLUDE IN THE TAFS.
CONDITIONS WILL LOWER WITH WIDESPREAD MVFR-IFR DEVELOPING.
A GRADUAL IMPROVEMENT WILL OCCUR WITH THE PASSAGE OF THE OCCLUDED
FRONT. WITH WIDESPREAD VFR FOR THE AFTERNOON.
HAVE NORTHEAST TO SOUTHEAST FLOW ACROSS AREA. RECENT OBSERVATIONS
SHOWN A DIMINISHING TREND IN WIND GUSTS ACROSS THE BERKSHIRES...
TACONICS AND SOUTHERN VERMONT WHERE THE FLOW HAS BEEN ENHANCED BY
THE TERRAIN. WINDS WILL LIGHTEN AS THE OCCLUDED BOUNDARY MOVES
THOUGH WITH A SHIFT TO SOUTHWEST TO WEST WITH ITS PASSAGE.
WESTERLY WINDS WILL INCREASE TO 10 TO 15 KNOTS AND WILL BE GUSTY
ESPECIALLY AT KALB AND KPSF.
OUTLOOK...
TUE NIGHT-WED: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WED NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
THU: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
THU NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRI: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
FRI NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SAT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
&&
.FIRE WEATHER...
THERE ARE NO FIRE WEATHER CONCERNS THIS WEEK AS WE WILL BE UNDER
THE INFLUENCE OF AN UPPER LEVEL TROUGH. A WIDESPREAD SOAKING
RAINFALL WILL OCCUR ACROSS THE AREA THROUGH 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 THROUGH 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...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/KL/LFM/11/WASULA
NEAR TERM...IAA/KL/LFM/11/WASULA
SHORT TERM...11
LONG TERM...IAA
AVIATION...IAA/WASULA
FIRE WEATHER...11
HYDROLOGY...IAA/KL/11
AREA FORECAST DISCUSSION...UPDATE
NWS PEACHTREE CITY GA
748 PM EDT WED APR 22 2015
.EVENING UPDATE...
A COLD FRONT IS PUSHING INTO FAR NW GA THIS EVENING. THIS COUPLED
WITH AN UPPER DISTURBANCE IS SPARKING SHOWERS AND THUNDERSTORMS
ACROSS NORTH AL AND NOW PUSHING INTO NW GA. EXPECT SCATTERED SHOWERS
AND THUNDERSTORMS TO CONTINUE DEVELOPING AHEAD OF THE FRONT AND
TRAVERSE ACROSS MAINLY FAR NORTH GA THROUGH THE EVENING. HIRES
MODELS HOLD THIS ACTIVITY MAINLY NORTH OF ATLANTA THROUGH THE
EVENING...BUT THE HRRR DOES SAG AT LEAST SHOWERS INTO THE ATLANTA
AREA SOMETIME SHORTLY AFTER MIDNIGHT. THIS SEEMS REASONABLE WITH THE
FRONT EXPECTED TO PUSH ACROSS ATLANTA BETWEEN 3-5 AM THU MORNING.
MESO ANALYSIS SHOWS AROUND 400-800 MUCAPE AND 20-25KT 0-1KM BULK
SHEAR... WHICH SUGGEST THE POTENTIAL FOR A FEW STRONG STORMS MOVING
INTO MAINLY NW AND NORTH CENTRAL GA THIS EVENING... WITH SMALL
HAIL... FREQUENT LTG... BRIEF HEAVY RAIN AND POSSIBLY WIND GUSTS TO
45 MPH BEING THE MAIN THREATS WITH THESE STORMS THIS EVENING. WILL
CONTINUE TO MONITOR THINGS CLOSELY AS THE FRONT SAGS INTO NORTH GA
THIS EVENING. EXPECT THE CURRENT STORMS TO SHOW SOME WEAKENING
THROUGH THE EVENING WITH LOSS OF DAYTIME HEATING. /39
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
/ISSUED AT 237 PM EDT WED APR 22 2015/
SURFACE COLD FRONT WILL MOVE INTO NORTH GA THIS EVENING AND INTO
CENTRAL GA BY THURSDAY MORNING...EXITING THE CWA BY 18Z THURSDAY.
MOISTURE IS VERY LIMITED AND THEREFORE WILL STAY WITH SLIGHT CHC/LOW
CHC POPS ACROSS NORTH GA TONIGHT AND INTO CENTRAL GA LATE TONIGHT. A
SECONDARY SHORT WAVE WILL MOVE ACROSS THE CWA WHICH WILL KEEP
CHC/SLGT CHC POPS ACROSS MOST OF THE CWA THURSDAY...BUT ENDING BY
00Z FRI. THERE IS SOME INSTABILITY THIS EVENING AND WILL KEEP THE
MENTION OF SLIGHT CHANCE TSRA...BUT BY 03Z THE INSTABILITY DECREASES
AND WILL GO WITH SHOWERS. WILL PUT THUNDER BACK IN THE GRIDS BY 15Z
AS DAYTIME HEATING HELPS ENHANCE THE LIMITED INSTABILITY THAT THERE
IS.
17
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
/ISSUED AT 237 PM EDT WED APR 22 2015/
NEEDED TO BUMP POPS UP FOR NORTH AND PORTIONS OF CENTRAL GA FRIDAY
NIGHT AND SATURDAY. OTHERWISE...MAINLY ONLY TWEAKS TO THE LONG TERM
BASED ON THE LASTEST GUIDANCE.
BDL
PREVIOUS DISCUSSION...
MEDIUM RANGE MODELS HAVE BECOME A BIT MORE CONSISTENT...BOTH RUN-TO-
RUN AND AMONGST EACH OTHER...THROUGH THE WEEKEND AT LEAST. EXTENDED
FORECAST PERIOD STARTS OUT DRY AND MILD IN THE WAKE OF THE MID-WEEK
SYSTEM. GFS AND ECMWF NOW MUCH BETTER ALIGNED BRINGING PRECIPITATION
BACK INTO THE REGION BY LATE FRIDAY WITH THE BEST CHANCES SATURDAY/
SATURDAY NIGHT AS A SERIES OF SHORT WAVES SWEEP THROUGH AND AN
ASSOCIATED SURFACE LOW/COLD FRONT MOVE ACROSS REGION. INSTABILITY IS
NOT FORECAST TO BE ALL THAT IMPRESSIVE...BUT SHOULD BE SUFFICIENT FOR
AT LEAST ISOLATED TO SCATTERED THUNDER WITH THIS SYSTEM. ALTHOUGH
THREAT OF SEVERE WEATHER LOOKS MINIMAL DUE TO LIMITED INSTABILITY...
STRONG LOW/MID-LEVEL WINDS SATURDAY BEAR WATCHING. A BIT OF A DRY
PERIOD SUNDAY BEHIND THIS SYSTEM WITH SEASONABLY MILD TEMPERATURES.
FOR THE REMAINDER OF THE EXTENDED FORECAST PERIOD THE GFS AND THE
ECMWF DIVERGE QUITE A BIT. BOTH INDICATE THE PERIOD WILL BE
UNSETTLED...BUT BOTH ALSO APPEAR TO BE SOMEWHAT OVER-AMPLIFIED AND
MORE THAN A LITTLE BIZARRE FOR THIS LATE IN THE SEASON. I BELIEVE ITS
PROBABLY A GOOD IDEA TO KEEP THE POPS AND TEMPERATURES A BIT MORE
GENERIC AND NOT SO EXTREME UNTIL THE MODELS HOPEFULLY SETTLE DOWN A
BIT ON LATER RUNS.
20
&&
.AVIATION...
00Z UPDATE...
VFR CONDITIONS WILL CONTINUE THIS THROUGH THE TAF PERIOD. A WEAK
COLD FRONT IS PUSHING INTO FAR NW GA WITH THIS UPDATE. RADAR SHOWS
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS AHEAD OF THE FRONT.
EXPECTING MAINLY MID LEVEL CIGS BY 03Z...THEN TEMPO -SHRA BETWEEN 08-
12Z TONIGHT AHEAD AND BEHIND THE FRONT. EXPECTING CURRENT WEST WINDS
TO SHIFT NW AROUND 08-09Z THU... THEN BECOME GUSTY BY 14-15Z THU.
WILL HOLD MID CLOUDS IN ON THU AS AN ACTIVE NW FLOW ALOFT IS NOTED
IN SOME MODELS.
//ATL CONFIDENCE...
00Z UPDATE...
MEDIUM ON -SHRA. HIGH ON REMAINING ELEMENTS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 53 71 46 72 / 20 30 5 20
ATLANTA 55 72 51 72 / 30 40 5 30
BLAIRSVILLE 43 63 38 69 / 20 20 5 20
CARTERSVILLE 46 69 42 70 / 20 30 5 30
COLUMBUS 58 77 55 78 / 30 40 10 30
GAINESVILLE 52 69 48 69 / 20 20 5 20
MACON 55 77 51 76 / 20 40 5 30
ROME 47 70 43 69 / 20 30 5 30
PEACHTREE CITY 52 74 48 72 / 30 40 5 30
VIDALIA 60 82 59 78 / 20 40 5 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...17
LONG TERM....BDL
AVIATION...17
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1002 PM CDT WED APR 22 2015
.UPDATE...
826 PM CDT
FOR EVENING UPDATE...
LOWERED OVERNIGHT MINS A BIT ESPECIALLY IN THE ROCK/FOX RIVER
VALLEYS WEST OF CHICAGO. CLEARING SKIES...DECOUPLING WINDS AND VERY
DRY LOW LEVEL AIR IS EXPECTED TO RESULT IN SUB-FREEZING TEMPS
OVERNIGHT AWAY FROM THE URBAN CORE OF CHICAGO.
THE FORECAST AREA REMAINS UNDER THE INFLUENCE OF LARGE UPPER TROUGH
ACROSS EASTERN NORTH AMERICA...AND SURFACE LOW PRESSURE SLOWLY
MOVING FROM NORTHEAST OF THE GREAT LAKES TOWARD NEW ENGLAND AND
SOUTHERN QUEBEC. COLD AIR ON BLUSTERY WEST-NORTHWEST WINDS AND
EXTENSIVE CLOSED-CELL STRATOCU HAD EARLIER RESULTED IN AFTERNOON
TEMPERATURES STRUGGLING TO RISE OUT OF THE 40S IN MOST AREAS...WITH
EVEN A FEW SNOW FLURRIES NOTED THANKS TO A COMBINATION OF COLD AIR
ALOFT (-5C AT 850 MB PER 21Z AMDAR ASCENT SOUNDING FROM MDW)...STEEP
BOUNDARY LAYER LAPSE RATES AND LOW WET-BULB ZERO HEIGHTS OF 500-1000
FEET.
CURRENT IR SATELLITE IMAGERY SHOWS WESTERN/SOUTHERN PERIPHERY OF THE
CLOUD SHIELD ERODING WITH LOSS OF DIURNAL SURFACE-BASED INSTABILITY
THOUGH PATCHY CLOUD COVER WILL LIKELY CONTINUE TO AFFECT PARTS OF
NORTHEAST IL/NORTHWEST INDIANA INTO THE NIGHT BENEATH SHEARED AND
ELONGATED MID-LEVEL VORTICITY CHANNEL...THOUGH EVEN THOSE AREAS WILL
LIKELY SEE CLOUDS SCATTER OVERNIGHT PER RAP RH PROGS. AS INDICATED
ABOVE...CLEARING SKIES AND DECREASING WINDS COMBINED WITH DRY LOW
LEVEL AIR MASS (SURFACE DEW POINTS TEENS-LOW 20S OVER NORTH CENTRAL
IL) WILL ALLOW TEMPS TO SINK INTO THE MID 20S AWAY FROM THE CITY
OVERNIGHT...POSSIBLY EVEN LOWER 20S IN SOME SHELTERED SPOTS WHERE
WINDS ABLE TO DECOUPLE MORE STRONGLY IN MODEST SFC PRESSURE
GRADIENT. EXPECT DEW POINT TEMPS ACROSS EASTERN IA...CURRENTLY IN
THE SINGLE DIGITS IN SOME SPOTS...WILL COME UP A LITTLE WITH LOSS OF
DEEPER MIXING AND DECREASE IN WINDS. OTHERWISE...COULD SEE NEEDING
TO LOWER MIN TEMPS EVEN MORE ESPECIALLY WEST OF THE FOX RIVER.
RATZER
&&
.SHORT TERM...
315 PM CDT
THROUGH FRIDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH THE BELOW NORMAL TEMPS
TO PERSIST AND WITH WELL BELOW NORMAL TEMPS AROUND OR BELOW
FREEZING TONIGHT AND THURSDAY NIGHT...WITH A FREEZE WARNING IN
EFFECT FOR THE ENTIRE CWA TONIGHT.
WITH THE LARGE UPPER LEVEL LOW STILL SPINNING JUST NORTHEAST OF
THE GREAT LAKES REGION...FAIRLY ENERGETIC FLOW CONTINUES TO MOVE
OVERHEAD. THIS COINCIDING WITH STEEP LOW LEVEL LAPSE RATES ACROSS
NORTHERN ILLINOIS AND NORTHWEST INDIANA...ISOLATED SHOWERY
ACTIVITY IS STILL ONGOING AT THIS TIME. THIS WILL LIKELY CONTINUE
OVER THE NEXT COUPLE OF HOURS...BEFORE DIMINISHING BY EARLY THIS
EVENING. PRECIP TYPE WILL BE EITHER FLURRIES OR SPRINKLES DURING
THIS TIME. DESPITE LOW TO MID 40 SURFACE TEMPS IN PLACE...VERY
COLD AIR ALOFT AND THESE STEEP LAPSE RATES WILL CONTINUE TO
SUPPORT THE DEVELOPMENT OF FLURRIES AT TIMES. EXTENSIVE CLOUD
COVER STILL IN PLACE THIS AFTERNOON WILL DIMINISH THROUGH THE
EARLY EVENING...WITH CLEARING SKIES EXPECTED THROUGH THE REMAINDER
OF THE EVENING AND OVERNIGHT. WITH THE VERY COLD AIRMASS IN PLACE
AND CLEARING SKIES...VERY CHILLY CONDITIONS WILL OCCUR OVER THE
ENTIRE CWA TONIGHT. HAVE LOWERED TEMPS A COUPLE OF DEGREES IN MOST
PLACES...WITH THE UPPER 20S TO AROUND 30 LIKELY FOR MOST LOCATIONS
AND LOWER 30S FOR THE CHICAGO METRO AREA. WITH THESE EXPECTED
TEMPS...HAVE ISSUED A FREEZE WARNING FOR THE ENTIRE CWA INCLUDING
COOK...FOR AREAS OUTSIDE OF THE IMMEDIATE CITY. THIS WILL START
JUST AFTER THE MIDNIGHT TIME FRAME...GOING THROUGH 13Z THURSDAY.
HAVE MADE MENTION OF PATCHY FROST TONIGHT BUT WITH THE WINDS
STAYING SLIGHTLY ELEVATED...WIDESPREAD FROST DOES NOT APPEAR
LIKELY AT THIS TIME. ANOTHER COLD NIGHT IN THE LOWER 30S IS LIKELY
THURSDAY NIGHT AND WITH HIGH PRESSURE AND LIGHT TO CALM WINDS
SETTLING IN...WIDESPREAD FROST APPEARS MORE LIKELY DURING THIS
TIME.
RODRIGUEZ
&&
.LONG TERM...
315 PM CDT
FRIDAY NIGHT THROUGH WEDNESDAY...
PRECIP CHANCES WILL BEGIN TO INCREASE BY THE START OF THE WEEKEND
AS MID/UPPER LEVEL TROUGH AND ASSOCIATED SURFACE LOW APPROACH FROM
THE CENTRAL PLAINS. THE ARRIVAL OF THIS SYSTEM AND BEST FORCING
APPEAR TO ARRIVE DURING THE DAY SATURDAY AND LIKELY CONTINUE INTO
THE EVENING. AT THIS TIME IT DOES LOOK LIKE THE ENTIRE CWA WILL
OBSERVE RAIN...BUT SOME GUIDANCE IS HINTING AT A MORE SOUTHERLY
TRACK. SO DID RAISE POPS ON SATURDAY BUT KEPT THE HIGHEST ACROSS
THE SOUTHERN HALF OF THE CWA. WITH THE DEPARTURE OF THIS SYSTEM
AND RAIN...CONDITIONS DRY AND LOOK TO REMAIN DRY THROUGH EARLY
NEXT WEEK...WITH A TREND TOWARDS MORE NORMAL TEMPS.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* GUSTY WEST/NORTHWEST WINDS THURSDAY. CMS
//DISCUSSION...UPDATED 00Z...
GUSTY NORTHWEST WINDS WILL DIMINISH THIS EVENING AND LIKELY
REMAIN IN THE 5-10KT MOST LOCATIONS...BUT MAY DROP OFF A BIT MORE
OVERNIGHT AS CLOUDS SCATTER. WINDS WILL INCREASE AGAIN THURSDAY
MORNING...BUT NOT AS STRONG AS TODAY WITH GUSTS IN THE UPPER TEENS
TO NEAR 20KT RANGE. WINDS WILL QUICKLY DIMINISH THURSDAY EVENING
AS HIGH PRESSURE MOVES ACROSS THE AREA. CMS
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH FOR WINDS THRU THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...SLIGHT CHANCE EVENING SHRA. VFR. EAST WINDS.
* SATURDAY...SHRA LIKELY. IFR LIKELY. STRONG/GUSTY NORTHEAST WINDS.
* SUNDAY THRU TUESDAY...DRY/VFR. NORTHEAST WINDS.
&&
.MARINE...
130 PM CDT
UNSEASONABLY STRONG LOW PRESSURE NEAR JAMES BAY CONTINUES TO
RESULT IN FAIRLY STRONG NORTHWEST WINDS ACROSS THE LAKE AND THESE
WINDS SHOULD CONTINUE INTO TONIGHT BEFORE HIGH PRESSURE OVER THE
PLAINS BEGINS TO MIGRATE EASTWARD TOWARD THE MISSISSIPPI VALLEY. A
COUPLE OF DAYS OF FAIRLY LIGHT WINDS DOMINATED BY LAND/LAKE BREEZE
CIRCULATIONS SHOULD ENSUE THURSDAY AND FRIDAY BEFORE ANOTHER
FAIRLY STRONG LOW PRESSURE CAUSES WINDS TO RAMP UP AGAIN FRIDAY
NIGHT AND ESPECIALLY SATURDAY. THIS LOW WILL PASS WELL SOUTH OF
THE LAKE SETTING THE STAGE FOR STRONG NORTHEASTERLY
WINDS...ESPECIALLY SOUTHERN PORTIONS OF THE LAKE WHERE WINDS COULD
END UP NOT TERRIBLY FAR FOR GALE FORCE FOR A TIME SATURDAY
AFTERNOON SHOULD THE STRONGER MODELS VERIFY. NORTHERLY WINDS WILL
BEGIN TO EASE SUNDAY WITH GRADIENT BECOMING FAIRLY WEAK HEADING
INTO NEXT WEEK WITH WINDS ONCE AGAIN PRIMARILY DOMINATED BY
LAKE/LAND BREEZE CIRCULATION.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FREEZE WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039...2 AM THURSDAY TO 8 AM
THURSDAY.
IN...FREEZE WARNING...INZ001-INZ002-INZ010-INZ011-INZ019...2 AM
THURSDAY TO 8 AM THURSDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN
UNTIL 10 PM WEDNESDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN
UNTIL 10 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
826 PM CDT WED APR 22 2015
.UPDATE...
826 PM CDT
FOR EVENING UPDATE...
LOWERED OVERNIGHT MINS A BIT ESPECIALLY IN THE ROCK/FOX RIVER
VALLEYS WEST OF CHICAGO. CLEARING SKIES...DECOUPLING WINDS AND VERY
DRY LOW LEVEL AIR IS EXPECTED TO RESULT IN SUB-FREEZING TEMPS
OVERNIGHT AWAY FROM THE URBAN CORE OF CHICAGO.
THE FORECAST AREA REMAINS UNDER THE INFLUENCE OF LARGE UPPER TROUGH
ACROSS EASTERN NORTH AMERICA...AND SURFACE LOW PRESSURE SLOWLY
MOVING FROM NORTHEAST OF THE GREAT LAKES TOWARD NEW ENGLAND AND
SOUTHERN QUEBEC. COLD AIR ON BLUSTERY WEST-NORTHWEST WINDS AND
EXTENSIVE CLOSED-CELL STRATOCU HAD EARLIER RESULTED IN AFTERNOON
TEMPERATURES STRUGGLING TO RISE OUT OF THE 40S IN MOST AREAS...WITH
EVEN A FEW SNOW FLURRIES NOTED THANKS TO A COMBINATION OF COLD AIR
ALOFT (-5C AT 850 MB PER 21Z AMDAR ASCENT SOUNDING FROM MDW)...STEEP
BOUNDARY LAYER LAPSE RATES AND LOW WET-BULB ZERO HEIGHTS OF 500-1000
FEET.
CURRENT IR SATELLITE IMAGERY SHOWS WESTERN/SOUTHERN PERIPHERY OF THE
CLOUD SHIELD ERODING WITH LOSS OF DIURNAL SURFACE-BASED INSTABILITY
THOUGH PATCHY CLOUD COVER WILL LIKELY CONTINUE TO AFFECT PARTS OF
NORTHEAST IL/NORTHWEST INDIANA INTO THE NIGHT BENEATH SHEARED AND
ELONGATED MID-LEVEL VORTICITY CHANNEL...THOUGH EVEN THOSE AREAS WILL
LIKELY SEE CLOUDS SCATTER OVERNIGHT PER RAP RH PROGS. AS INDICATED
ABOVE...CLEARING SKIES AND DECREASING WINDS COMBINED WITH DRY LOW
LEVEL AIR MASS (SURFACE DEW POINTS TEENS-LOW 20S OVER NORTH CENTRAL
IL) WILL ALLOW TEMPS TO SINK INTO THE MID 20S AWAY FROM THE CITY
OVERNIGHT...POSSIBLY EVEN LOWER 20S IN SOME SHELTERED SPOTS WHERE
WINDS ABLE TO DECOUPLE MORE STRONGLY IN MODEST SFC PRESSURE
GRADIENT. EXPECT DEW POINT TEMPS ACROSS EASTERN IA...CURRENTLY IN
THE SINGLE DIGITS IN SOME SPOTS...WILL COME UP A LITTLE WITH LOSS OF
DEEPER MIXING AND DECREASE IN WINDS. OTHERWISE...COULD SEE NEEDING
TO LOWER MIN TEMPS EVEN MORE ESPECIALLY WEST OF THE FOX RIVER.
RATZER
&&
.SHORT TERM...
315 PM CDT
THROUGH FRIDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH THE BELOW NORMAL TEMPS
TO PERSIST AND WITH WELL BELOW NORMAL TEMPS AROUND OR BELOW
FREEZING TONIGHT AND THURSDAY NIGHT...WITH A FREEZE WARNING IN
EFFECT FOR THE ENTIRE CWA TONIGHT.
WITH THE LARGE UPPER LEVEL LOW STILL SPINNING JUST NORTHEAST OF
THE GREAT LAKES REGION...FAIRLY ENERGETIC FLOW CONTINUES TO MOVE
OVERHEAD. THIS COINCIDING WITH STEEP LOW LEVEL LAPSE RATES ACROSS
NORTHERN ILLINOIS AND NORTHWEST INDIANA...ISOLATED SHOWERY
ACTIVITY IS STILL ONGOING AT THIS TIME. THIS WILL LIKELY CONTINUE
OVER THE NEXT COUPLE OF HOURS...BEFORE DIMINISHING BY EARLY THIS
EVENING. PRECIP TYPE WILL BE EITHER FLURRIES OR SPRINKLES DURING
THIS TIME. DESPITE LOW TO MID 40 SURFACE TEMPS IN PLACE...VERY
COLD AIR ALOFT AND THESE STEEP LAPSE RATES WILL CONTINUE TO
SUPPORT THE DEVELOPMENT OF FLURRIES AT TIMES. EXTENSIVE CLOUD
COVER STILL IN PLACE THIS AFTERNOON WILL DIMINISH THROUGH THE
EARLY EVENING...WITH CLEARING SKIES EXPECTED THROUGH THE REMAINDER
OF THE EVENING AND OVERNIGHT. WITH THE VERY COLD AIRMASS IN PLACE
AND CLEARING SKIES...VERY CHILLY CONDITIONS WILL OCCUR OVER THE
ENTIRE CWA TONIGHT. HAVE LOWERED TEMPS A COUPLE OF DEGREES IN MOST
PLACES...WITH THE UPPER 20S TO AROUND 30 LIKELY FOR MOST LOCATIONS
AND LOWER 30S FOR THE CHICAGO METRO AREA. WITH THESE EXPECTED
TEMPS...HAVE ISSUED A FREEZE WARNING FOR THE ENTIRE CWA INCLUDING
COOK...FOR AREAS OUTSIDE OF THE IMMEDIATE CITY. THIS WILL START
JUST AFTER THE MIDNIGHT TIME FRAME...GOING THROUGH 13Z THURSDAY.
HAVE MADE MENTION OF PATCHY FROST TONIGHT BUT WITH THE WINDS
STAYING SLIGHTLY ELEVATED...WIDESPREAD FROST DOES NOT APPEAR
LIKELY AT THIS TIME. ANOTHER COLD NIGHT IN THE LOWER 30S IS LIKELY
THURSDAY NIGHT AND WITH HIGH PRESSURE AND LIGHT TO CALM WINDS
SETTLING IN...WIDESPREAD FROST APPEARS MORE LIKELY DURING THIS
TIME.
RODRIGUEZ
&&
.LONG TERM...
315 PM CDT
FRIDAY NIGHT THROUGH WEDNESDAY...
PRECIP CHANCES WILL BEGIN TO INCREASE BY THE START OF THE WEEKEND
AS MID/UPPER LEVEL TROUGH AND ASSOCIATED SURFACE LOW APPROACH FROM
THE CENTRAL PLAINS. THE ARRIVAL OF THIS SYSTEM AND BEST FORCING
APPEAR TO ARRIVE DURING THE DAY SATURDAY AND LIKELY CONTINUE INTO
THE EVENING. AT THIS TIME IT DOES LOOK LIKE THE ENTIRE CWA WILL
OBSERVE RAIN...BUT SOME GUIDANCE IS HINTING AT A MORE SOUTHERLY
TRACK. SO DID RAISE POPS ON SATURDAY BUT KEPT THE HIGHEST ACROSS
THE SOUTHERN HALF OF THE CWA. WITH THE DEPARTURE OF THIS SYSTEM
AND RAIN...CONDITIONS DRY AND LOOK TO REMAIN DRY THROUGH EARLY
NEXT WEEK...WITH A TREND TOWARDS MORE NORMAL TEMPS.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* GUSTY WEST/NORTHWEST WINDS EARLY THIS EVENING.
* GUSTY WEST/NORTHWEST WINDS THURSDAY. CMS
//DISCUSSION...UPDATED 00Z...
GUSTY NORTHWEST WINDS WILL DIMINISH THIS EVENING AND LIKELY
REMAIN IN THE 5-10KT MOST LOCATIONS...BUT MAY DROP OFF A BIT MORE
OVERNIGHT AS CLOUDS SCATTER. WINDS WILL INCREASE AGAIN THURSDAY
MORNING...BUT NOT AS STRONG AS TODAY WITH GUSTS IN THE UPPER TEENS
TO NEAR 20KT RANGE. WINDS WILL QUICKLY DIMINISH THURSDAY EVENING
AS HIGH PRESSURE MOVES ACROSS THE AREA. CMS
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH FOR WINDS THRU THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...SLIGHT CHANCE EVENING SHRA. VFR. EAST WINDS.
* SATURDAY...SHRA LIKELY. IFR LIKELY. STRONG/GUSTY NORTHEAST WINDS.
* SUNDAY THRU TUESDAY...DRY/VFR. NORTHEAST WINDS.
&&
.MARINE...
130 PM CDT
UNSEASONABLY STRONG LOW PRESSURE NEAR JAMES BAY CONTINUES TO
RESULT IN FAIRLY STRONG NORTHWEST WINDS ACROSS THE LAKE AND THESE
WINDS SHOULD CONTINUE INTO TONIGHT BEFORE HIGH PRESSURE OVER THE
PLAINS BEGINS TO MIGRATE EASTWARD TOWARD THE MISSISSIPPI VALLEY. A
COUPLE OF DAYS OF FAIRLY LIGHT WINDS DOMINATED BY LAND/LAKE BREEZE
CIRCULATIONS SHOULD ENSUE THURSDAY AND FRIDAY BEFORE ANOTHER
FAIRLY STRONG LOW PRESSURE CAUSES WINDS TO RAMP UP AGAIN FRIDAY
NIGHT AND ESPECIALLY SATURDAY. THIS LOW WILL PASS WELL SOUTH OF
THE LAKE SETTING THE STAGE FOR STRONG NORTHEASTERLY
WINDS...ESPECIALLY SOUTHERN PORTIONS OF THE LAKE WHERE WINDS COULD
END UP NOT TERRIBLY FAR FOR GALE FORCE FOR A TIME SATURDAY
AFTERNOON SHOULD THE STRONGER MODELS VERIFY. NORTHERLY WINDS WILL
BEGIN TO EASE SUNDAY WITH GRADIENT BECOMING FAIRLY WEAK HEADING
INTO NEXT WEEK WITH WINDS ONCE AGAIN PRIMARILY DOMINATED BY
LAKE/LAND BREEZE CIRCULATION.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FREEZE WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039...2 AM THURSDAY TO 8 AM
THURSDAY.
IN...FREEZE WARNING...INZ001-INZ002-INZ010-INZ011-INZ019...2 AM
THURSDAY TO 8 AM THURSDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 PM
WEDNESDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1230 PM CDT TUE APR 21 2015
.UPDATE...
ISSUED AT 1012 AM CDT TUE APR 21 2015
MAIN FORECAST CONCERN WILL BE WITH THE WINDS TODAY. ALREADY
STARTING TO SEE WIND GUSTS TO AROUND 30 MPH ACROSS THE NORTHERN
CWA. LATEST HRRR AND RAP DATA SUGGESTING A PERIOD OF 40-45 KNOTS
FOR A FEW HOURS EARLY THIS AFTERNOON ACROSS MAINLY AREAS ALONG AND
NORTH OF I-74...ALTHOUGH THEY ARE ALSO NOW SUGGESTING THIS AS FAR
SOUTH AS THE I-70 CORRIDOR. HAVE NOT GONE THAT HIGH SO FAR SOUTH
AS CLOUDS THERE WILL BE ON THE INCREASE AND PREVENT FULL MIXING...
BUT RAISED THE WIND GUSTS A TAD OVER THE NORTH AS MOSTLY SUNNY
CONDITIONS CONTINUE INTO AT LEAST MID AFTERNOON.
&&
.SHORT TERM...(TODAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
WINDY CONDITIONS WILL ONCE AGAIN DEVELOP ACROSS CENTRAL ILLINOIS
TODAY, THANKS TO A TIGHTENING PRESSURE GRADIENT AND DEEP-LAYER
MIXING. THE STRONGEST WINDS WILL BE FOCUSED ALONG/NORTH OF THE I-74
CORRIDOR, WHERE FORECAST SOUNDINGS SUGGEST SUSTAINED WINDS OF AROUND
30MPH WITH GUSTS UP TO 40MPH AT TIMES. WILL THEREFORE ISSUE A
WIND ADVISORY FOR THIS AREA FROM 11AM TO 7PM. FURTHER SOUTH
ACROSS THE REMAINDER OF THE KILX CWA, WINDS WILL REMAIN BELOW
ADVISORY CRITERIA, MAINLY IN THE 25 TO 30MPH RANGE. SKIES WILL
BE MOSTLY SUNNY THROUGH MUCH OF THE DAY, WITH AN INCREASE IN
CLOUDS NOTED ACROSS THE FAR SOUTH DURING THE AFTERNOON AS A
MID-LEVEL SHORT-WAVE APPROACHES FROM THE WEST. ALL MODELS ARE
DEVELOPING SCATTERED SHOWERS/THUNDER IN ADVANCE OF THIS WAVE, BUT
PRIMARILY KEEP THE ACTIVITY JUST SOUTH OF THE CWA. HIGHER-RES
MODELS SUCH AS THE HRRR ARE SLIGHTLY FURTHER NORTH, SO HAVE OPTED
TO INCLUDE SLIGHT CHANCE POPS FOR SHOWERS SOUTH OF I-70 THIS
AFTERNOON. THANKS TO INCREASED SUNSHINE, HIGH TEMPERATURES WILL
BE A FEW DEGREES WARMER THAN YESTERDAY, WITH READINGS CLIMBING
INTO THE LOWER TO MIDDLE 60S.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
MAIN CHALLENGES IN THE EXTENDED CONTINUE TO BE FROST POTENTIAL
WEDNESDAY/THURSDAY NIGHTS, AS WELL AS, TIMING OF NEXT PRECIP EVENT
BY THE END OF THE WEEK.
DEEP UPPER LOW CURRENTLY CENTERED OVER THE WESTERN GREAT LAKES WILL
BE THE DOMINANT WEATHER FEATURE ACROSS THE MIDWEST FOR THE NEXT FEW
DAYS, RESULTING IN COOL CONDITIONS THROUGH FRIDAY. AS A PIECE OF
ENERGY ROTATES AROUND THE LOW, A WEAK COLD FRONT WILL DROP THROUGH
ILLINOIS TONIGHT. FORECAST SOUNDINGS ARE INITIALLY QUITE DRY:
HOWEVER, THE LATEST MODELS SHOW QUITE A BIT MORE TOP-DOWN MOISTENING
THAN IN PREVIOUS RUNS. AS A RESULT, THINK SCATTERED LIGHT SHOWERS
WILL ACCOMPANY THE FRONT TONIGHT, WITH PERHAPS A FEW SHOWERS
LINGERING INTO WEDNESDAY MORNING ACROSS THE FAR SE. ONCE THE
FRONT EXITS, CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION FOR
THE MIDDLE AND END OF THE WEEK. THE RIDGE AXIS IS PROGGED TO BE
JUST WEST OF THE MISSISSIPPI RIVER BY 12Z THURSDAY, SO AM
EXPECTING WINDS TO DIMINISH CONSIDERABLY AS THE PRESSURE GRADIENT
WEAKENS. WITH CLEAR SKIES AND LIGHT WINDS, OVERNIGHT LOWS WILL
DIP INTO THE LOWER TO MIDDLE 30S, LEADING TO FROST DEVELOPMENT
ACROSS MUCH OF THE AREA. IF SKIES REMAIN CLEAR, ANOTHER
POTENTIALLY FROSTY NIGHT WILL OCCUR THURSDAY NIGHT AS WELL.
FURTHER OUT, MODELS ARE HAVING CONSIDERABLE DIFFICULTY PINNING DOWN
THE END OF THE WEEK SYSTEM. SOLUTIONS HAVE BEEN FLIP-FLOPPING FROM
RUN TO RUN, SO OVERALL FORECAST CONFIDENCE BEYOND THURSDAY REMAINS
LOWS. THE 00Z APR 21 GFS HAS MADE A MAJOR SHIFT BACK TO A SOLUTION
IT FEATURED A COUPLE OF DAYS AGO. MEANWHILE, BOTH THE ECMWF AND GEM
SEEM TO BE HEADING IN THE OPPOSITE DIRECTION. GIVEN SO MUCH MODEL
INCONSISTENCY, PREFER TO MAKE VERY FEW CHANGES TO THE EXTENDED.
WITH CANADIAN HIGH PRESSURE INITIALLY IN PLACE ACROSS THE MIDWEST ON
WEDNESDAY/THURSDAY, STILL THINK A SLOWER ARRIVAL OF THE NEXT STORM
SYSTEM MAKES SENSE. AS A RESULT, HAVE KEPT FRIDAY DRY DESPITE WHAT
THE ECMWF AND GEM ARE ADVERTISING. HAVE INTRODUCED POPS FRIDAY
NIGHT INTO SATURDAY AS A SYSTEM OVER THE DESERT SOUTHWEST GETS
KICKED EASTWARD. STILL QUITE A BIT OF UNCERTAINTY CONCERNING HOW
FAR NORTH PRECIP WILL SPREAD, BUT HAVE STUCK WITH PREVIOUS THINKING
OF KEEPING HIGHEST POPS FOCUSED ACROSS THE SOUTHERN HALF OF THE CWA.
THIS IS IN GOOD AGREEMENT WITH THE LATEST GFS, BUT NOT THE ECMWF/GEM
WHICH BOTH FOCUS PRECIP MUCH FURTHER NORTH. ONCE THE SYSTEM EXITS,
A RETURN TO DRY WEATHER IS ANTICIPATED FOR SUNDAY BEFORE ANOTHER
FAST-MOVING NORTHERN-STREAM WAVE POTENTIALLY BRINGS A FEW SHOWERS
BACK INTO THE PICTURE BY MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1230 PM CDT TUE APR 21 2015
STRONG WINDS GUSTING TO THE SURFACE NOW...WITH SOME GUSTS NEAR 35
KNOTS AT MIDDAY AROUND KPIA. STRONGEST WINDS EXPECTED IN THE
KPIA-KCMI CORRIDOR THROUGH AFTERNOON WITH SEVERAL GUSTS 30-40
KNOTS...WITH GUSTS STARTING TO TAIL OFF TOWARD 00Z. HAVE SEEN SOME
INCREASE IN DIURNAL CLOUDS AROUND 6000 FEET...AND VFR CONDITIONS
EXPECTED TO PREVAIL...ALTHOUGH CEILINGS WILL THICKEN UP AFTER
SUNSET. AREA OF RAIN SHOWERS WITH A FRONT WILL MOVE THROUGH
CENTRAL ILLINOIS MID TO LATE EVENING...BUT A FAIR AMOUNT OF DRY
AIR IS NOTED BELOW 4000 FEET ON FORECAST SOUNDINGS...SO WILL
CONTINUE MENTION WITH VCSH FOR NOW. HOWEVER...CEILINGS SHOULD
DROP CLOSER TO AROUND 3500-4000 FEET FOR SEVERAL HOURS...BEFORE
RISING OVERNIGHT BEHIND THE FRONT. SOME GUSTY NORTHWEST WINDS
EXPECTED AGAIN LATE WEDNESDAY MORNING...ALTHOUGH THESE SHOULD BE
ABOUT 20 KNOTS OR LESS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-037-038-
043>046.
&&
$$
UPDATE...GEELHART
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1013 AM CDT TUE APR 21 2015
.UPDATE...
ISSUED AT 1012 AM CDT TUE APR 21 2015
MAIN FORECAST CONCERN WILL BE WITH THE WINDS TODAY. ALREADY
STARTING TO SEE WIND GUSTS TO AROUND 30 MPH ACROSS THE NORTHERN
CWA. LATEST HRRR AND RAP DATA SUGGESTING A PERIOD OF 40-45 KNOTS
FOR A FEW HOURS EARLY THIS AFTERNOON ACROSS MAINLY AREAS ALONG AND
NORTH OF I-74...ALTHOUGH THEY ARE ALSO NOW SUGGESTING THIS AS FAR
SOUTH AS THE I-70 CORRIDOR. HAVE NOT GONE THAT HIGH SO FAR SOUTH
AS CLOUDS THERE WILL BE ON THE INCREASE AND PREVENT FULL MIXING...
BUT RAISED THE WIND GUSTS A TAD OVER THE NORTH AS MOSTLY SUNNY
CONDITIONS CONTINUE INTO AT LEAST MID AFTERNOON.
&&
.SHORT TERM...(TODAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
WINDY CONDITIONS WILL ONCE AGAIN DEVELOP ACROSS CENTRAL ILLINOIS
TODAY, THANKS TO A TIGHTENING PRESSURE GRADIENT AND DEEP-LAYER
MIXING. THE STRONGEST WINDS WILL BE FOCUSED ALONG/NORTH OF THE I-74
CORRIDOR, WHERE FORECAST SOUNDINGS SUGGEST SUSTAINED WINDS OF AROUND
30MPH WITH GUSTS UP TO 40MPH AT TIMES. WILL THEREFORE ISSUE A
WIND ADVISORY FOR THIS AREA FROM 11AM TO 7PM. FURTHER SOUTH
ACROSS THE REMAINDER OF THE KILX CWA, WINDS WILL REMAIN BELOW
ADVISORY CRITERIA, MAINLY IN THE 25 TO 30MPH RANGE. SKIES WILL
BE MOSTLY SUNNY THROUGH MUCH OF THE DAY, WITH AN INCREASE IN
CLOUDS NOTED ACROSS THE FAR SOUTH DURING THE AFTERNOON AS A
MID-LEVEL SHORT-WAVE APPROACHES FROM THE WEST. ALL MODELS ARE
DEVELOPING SCATTERED SHOWERS/THUNDER IN ADVANCE OF THIS WAVE, BUT
PRIMARILY KEEP THE ACTIVITY JUST SOUTH OF THE CWA. HIGHER-RES
MODELS SUCH AS THE HRRR ARE SLIGHTLY FURTHER NORTH, SO HAVE OPTED
TO INCLUDE SLIGHT CHANCE POPS FOR SHOWERS SOUTH OF I-70 THIS
AFTERNOON. THANKS TO INCREASED SUNSHINE, HIGH TEMPERATURES WILL
BE A FEW DEGREES WARMER THAN YESTERDAY, WITH READINGS CLIMBING
INTO THE LOWER TO MIDDLE 60S.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
MAIN CHALLENGES IN THE EXTENDED CONTINUE TO BE FROST POTENTIAL
WEDNESDAY/THURSDAY NIGHTS, AS WELL AS, TIMING OF NEXT PRECIP EVENT
BY THE END OF THE WEEK.
DEEP UPPER LOW CURRENTLY CENTERED OVER THE WESTERN GREAT LAKES WILL
BE THE DOMINANT WEATHER FEATURE ACROSS THE MIDWEST FOR THE NEXT FEW
DAYS, RESULTING IN COOL CONDITIONS THROUGH FRIDAY. AS A PIECE OF
ENERGY ROTATES AROUND THE LOW, A WEAK COLD FRONT WILL DROP THROUGH
ILLINOIS TONIGHT. FORECAST SOUNDINGS ARE INITIALLY QUITE DRY:
HOWEVER, THE LATEST MODELS SHOW QUITE A BIT MORE TOP-DOWN MOISTENING
THAN IN PREVIOUS RUNS. AS A RESULT, THINK SCATTERED LIGHT SHOWERS
WILL ACCOMPANY THE FRONT TONIGHT, WITH PERHAPS A FEW SHOWERS
LINGERING INTO WEDNESDAY MORNING ACROSS THE FAR SE. ONCE THE
FRONT EXITS, CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION FOR
THE MIDDLE AND END OF THE WEEK. THE RIDGE AXIS IS PROGGED TO BE
JUST WEST OF THE MISSISSIPPI RIVER BY 12Z THURSDAY, SO AM
EXPECTING WINDS TO DIMINISH CONSIDERABLY AS THE PRESSURE GRADIENT
WEAKENS. WITH CLEAR SKIES AND LIGHT WINDS, OVERNIGHT LOWS WILL
DIP INTO THE LOWER TO MIDDLE 30S, LEADING TO FROST DEVELOPMENT
ACROSS MUCH OF THE AREA. IF SKIES REMAIN CLEAR, ANOTHER
POTENTIALLY FROSTY NIGHT WILL OCCUR THURSDAY NIGHT AS WELL.
FURTHER OUT, MODELS ARE HAVING CONSIDERABLE DIFFICULTY PINNING DOWN
THE END OF THE WEEK SYSTEM. SOLUTIONS HAVE BEEN FLIP-FLOPPING FROM
RUN TO RUN, SO OVERALL FORECAST CONFIDENCE BEYOND THURSDAY REMAINS
LOWS. THE 00Z APR 21 GFS HAS MADE A MAJOR SHIFT BACK TO A SOLUTION
IT FEATURED A COUPLE OF DAYS AGO. MEANWHILE, BOTH THE ECMWF AND GEM
SEEM TO BE HEADING IN THE OPPOSITE DIRECTION. GIVEN SO MUCH MODEL
INCONSISTENCY, PREFER TO MAKE VERY FEW CHANGES TO THE EXTENDED.
WITH CANADIAN HIGH PRESSURE INITIALLY IN PLACE ACROSS THE MIDWEST ON
WEDNESDAY/THURSDAY, STILL THINK A SLOWER ARRIVAL OF THE NEXT STORM
SYSTEM MAKES SENSE. AS A RESULT, HAVE KEPT FRIDAY DRY DESPITE WHAT
THE ECMWF AND GEM ARE ADVERTISING. HAVE INTRODUCED POPS FRIDAY
NIGHT INTO SATURDAY AS A SYSTEM OVER THE DESERT SOUTHWEST GETS
KICKED EASTWARD. STILL QUITE A BIT OF UNCERTAINTY CONCERNING HOW
FAR NORTH PRECIP WILL SPREAD, BUT HAVE STUCK WITH PREVIOUS THINKING
OF KEEPING HIGHEST POPS FOCUSED ACROSS THE SOUTHERN HALF OF THE CWA.
THIS IS IN GOOD AGREEMENT WITH THE LATEST GFS, BUT NOT THE ECMWF/GEM
WHICH BOTH FOCUS PRECIP MUCH FURTHER NORTH. ONCE THE SYSTEM EXITS,
A RETURN TO DRY WEATHER IS ANTICIPATED FOR SUNDAY BEFORE ANOTHER
FAST-MOVING NORTHERN-STREAM WAVE POTENTIALLY BRINGS A FEW SHOWERS
BACK INTO THE PICTURE BY MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 634 AM CDT TUE APR 21 2015
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES NEXT 24HRS. CLEAR
SKIES WILL GIVE WAY TO SCATTERED MID CLOUDS ADVECTING THROUGH THE
AREA THIS MORNING AND INTO THIS AFTERNOON. HEIGHT OF CLOUDS WILL
LOWER TO AROUND 8KFT LATER THIS EVENING JUST AHEAD OF A WEAK COLD
FRONT EXPECTED TO MOVE THROUGH THE AREA TONIGHT. BELIEVE LOWER
LAYERS WILL BE TOO DRY FOR PCPN AT FIRST, BUT THINKING SHOWERS
WILL BE POSSIBLE IN CONJUNCTION WITH THE FRONT BEGINNING LATE IN
THE EVENING AND CONTINUING INTO THE OVERNIGHT HOURS. CIGS MAY
LOWER INTO MVFR RANGES WITH PCPN, BUT NOT CONFIDENT WITH THIS,
SO WILL KEEP CIGS IN VFR RANGES. PCPN WILL LIKELY END BEFORE
SUNRISE. WEST WINDS WILL BECOME QUITE GUSTY AGAIN TODAY AND SHOULD
GET UP TO 30-35KTS DURING THE AFTERNOON. AFTER SUNSET WINDS WILL
TAPER OFF BUT STILL LOOKING AT 11-13KTS DURING THE EVENING. AS THE
FRONT MOVES THROUGH AROUND MIDNIGHT, WINDS WILL BECOME
NORTHWESTERLY AND STILL OVER 10KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-037-038-
043>046.
&&
$$
UPDATE...GEELHART
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
634 AM CDT TUE APR 21 2015
.SHORT TERM...(TODAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
WINDY CONDITIONS WILL ONCE AGAIN DEVELOP ACROSS CENTRAL ILLINOIS
TODAY, THANKS TO A TIGHTENING PRESSURE GRADIENT AND DEEP-LAYER
MIXING. THE STRONGEST WINDS WILL BE FOCUSED ALONG/NORTH OF THE I-74
CORRIDOR, WHERE FORECAST SOUNDINGS SUGGEST SUSTAINED WINDS OF AROUND
30MPH WITH GUSTS UP TO 40MPH AT TIMES. WILL THEREFORE ISSUE A
WIND ADVISORY FOR THIS AREA FROM 11AM TO 7PM. FURTHER SOUTH
ACROSS THE REMAINDER OF THE KILX CWA, WINDS WILL REMAIN BELOW
ADVISORY CRITERIA, MAINLY IN THE 25 TO 30MPH RANGE. SKIES WILL
BE MOSTLY SUNNY THROUGH MUCH OF THE DAY, WITH AN INCREASE IN
CLOUDS NOTED ACROSS THE FAR SOUTH DURING THE AFTERNOON AS A
MID-LEVEL SHORT-WAVE APPROACHES FROM THE WEST. ALL MODELS ARE
DEVELOPING SCATTERED SHOWERS/THUNDER IN ADVANCE OF THIS WAVE, BUT
PRIMARILY KEEP THE ACTIVITY JUST SOUTH OF THE CWA. HIGHER-RES
MODELS SUCH AS THE HRRR ARE SLIGHTLY FURTHER NORTH, SO HAVE OPTED
TO INCLUDE SLIGHT CHANCE POPS FOR SHOWERS SOUTH OF I-70 THIS
AFTERNOON. THANKS TO INCREASED SUNSHINE, HIGH TEMPERATURES WILL
BE A FEW DEGREES WARMER THAN YESTERDAY, WITH READINGS CLIMBING
INTO THE LOWER TO MIDDLE 60S.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
MAIN CHALLENGES IN THE EXTENDED CONTINUE TO BE FROST POTENTIAL
WEDNESDAY/THURSDAY NIGHTS, AS WELL AS, TIMING OF NEXT PRECIP EVENT
BY THE END OF THE WEEK.
DEEP UPPER LOW CURRENTLY CENTERED OVER THE WESTERN GREAT LAKES WILL
BE THE DOMINANT WEATHER FEATURE ACROSS THE MIDWEST FOR THE NEXT FEW
DAYS, RESULTING IN COOL CONDITIONS THROUGH FRIDAY. AS A PIECE OF
ENERGY ROTATES AROUND THE LOW, A WEAK COLD FRONT WILL DROP THROUGH
ILLINOIS TONIGHT. FORECAST SOUNDINGS ARE INITIALLY QUITE DRY:
HOWEVER, THE LATEST MODELS SHOW QUITE A BIT MORE TOP-DOWN MOISTENING
THAN IN PREVIOUS RUNS. AS A RESULT, THINK SCATTERED LIGHT SHOWERS
WILL ACCOMPANY THE FRONT TONIGHT, WITH PERHAPS A FEW SHOWERS
LINGERING INTO WEDNESDAY MORNING ACROSS THE FAR SE. ONCE THE
FRONT EXITS, CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION FOR
THE MIDDLE AND END OF THE WEEK. THE RIDGE AXIS IS PROGGED TO BE
JUST WEST OF THE MISSISSIPPI RIVER BY 12Z THURSDAY, SO AM
EXPECTING WINDS TO DIMINISH CONSIDERABLY AS THE PRESSURE GRADIENT
WEAKENS. WITH CLEAR SKIES AND LIGHT WINDS, OVERNIGHT LOWS WILL
DIP INTO THE LOWER TO MIDDLE 30S, LEADING TO FROST DEVELOPMENT
ACROSS MUCH OF THE AREA. IF SKIES REMAIN CLEAR, ANOTHER
POTENTIALLY FROSTY NIGHT WILL OCCUR THURSDAY NIGHT AS WELL.
FURTHER OUT, MODELS ARE HAVING CONSIDERABLE DIFFICULTY PINNING DOWN
THE END OF THE WEEK SYSTEM. SOLUTIONS HAVE BEEN FLIP-FLOPPING FROM
RUN TO RUN, SO OVERALL FORECAST CONFIDENCE BEYOND THURSDAY REMAINS
LOWS. THE 00Z APR 21 GFS HAS MADE A MAJOR SHIFT BACK TO A SOLUTION
IT FEATURED A COUPLE OF DAYS AGO. MEANWHILE, BOTH THE ECMWF AND GEM
SEEM TO BE HEADING IN THE OPPOSITE DIRECTION. GIVEN SO MUCH MODEL
INCONSISTENCY, PREFER TO MAKE VERY FEW CHANGES TO THE EXTENDED.
WITH CANADIAN HIGH PRESSURE INITIALLY IN PLACE ACROSS THE MIDWEST ON
WEDNESDAY/THURSDAY, STILL THINK A SLOWER ARRIVAL OF THE NEXT STORM
SYSTEM MAKES SENSE. AS A RESULT, HAVE KEPT FRIDAY DRY DESPITE WHAT
THE ECMWF AND GEM ARE ADVERTISING. HAVE INTRODUCED POPS FRIDAY
NIGHT INTO SATURDAY AS A SYSTEM OVER THE DESERT SOUTHWEST GETS
KICKED EASTWARD. STILL QUITE A BIT OF UNCERTAINTY CONCERNING HOW
FAR NORTH PRECIP WILL SPREAD, BUT HAVE STUCK WITH PREVIOUS THINKING
OF KEEPING HIGHEST POPS FOCUSED ACROSS THE SOUTHERN HALF OF THE CWA.
THIS IS IN GOOD AGREEMENT WITH THE LATEST GFS, BUT NOT THE ECMWF/GEM
WHICH BOTH FOCUS PRECIP MUCH FURTHER NORTH. ONCE THE SYSTEM EXITS,
A RETURN TO DRY WEATHER IS ANTICIPATED FOR SUNDAY BEFORE ANOTHER
FAST-MOVING NORTHERN-STREAM WAVE POTENTIALLY BRINGS A FEW SHOWERS
BACK INTO THE PICTURE BY MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 634 AM CDT TUE APR 21 2015
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES NEXT 24HRS. CLEAR
SKIES WILL GIVE WAY TO SCATTERED MID CLOUDS ADVECTING THROUGH THE
AREA THIS MORNING AND INTO THIS AFTERNOON. HEIGHT OF CLOUDS WILL
LOWER TO AROUND 8KFT LATER THIS EVENING JUST AHEAD OF A WEAK COLD
FRONT EXPECTED TO MOVE THROUGH THE AREA TONIGHT. BELIEVE LOWER
LAYERS WILL BE TOO DRY FOR PCPN AT FIRST, BUT THINKING SHOWERS
WILL BE POSSIBLE IN CONJUNCTION WITH THE FRONT BEGINNING LATE IN
THE EVENING AND CONTINUING INTO THE OVERNIGHT HOURS. CIGS MAY
LOWER INTO MVFR RANGES WITH PCPN, BUT NOT CONFIDENT WITH THIS,
SO WILL KEEP CIGS IN VFR RANGES. PCPN WILL LIKELY END BEFORE
SUNRISE. WEST WINDS WILL BECOME QUITE GUSTY AGAIN TODAY AND SHOULD
GET UP TO 30-35KTS DURING THE AFTERNOON. AFTER SUNSET WINDS WILL
TAPER OFF BUT STILL LOOKING AT 11-13KTS DURING THE EVENING. AS THE
FRONT MOVES THROUGH AROUND MIDNIGHT, WINDS WILL BECOME
NORTHWESTERLY AND STILL OVER 10KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR ILZ027>031-037-038-043>046.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
323 AM CDT TUE APR 21 2015
.SHORT TERM...(TODAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
WINDY CONDITIONS WILL ONCE AGAIN DEVELOP ACROSS CENTRAL ILLINOIS
TODAY, THANKS TO A TIGHTENING PRESSURE GRADIENT AND DEEP-LAYER
MIXING. THE STRONGEST WINDS WILL BE FOCUSED ALONG/NORTH OF THE I-74
CORRIDOR, WHERE FORECAST SOUNDINGS SUGGEST SUSTAINED WINDS OF AROUND
30MPH WITH GUSTS UP TO 40MPH AT TIMES. WILL THEREFORE ISSUE A
WIND ADVISORY FOR THIS AREA FROM 11AM TO 7PM. FURTHER SOUTH
ACROSS THE REMAINDER OF THE KILX CWA, WINDS WILL REMAIN BELOW
ADVISORY CRITERIA, MAINLY IN THE 25 TO 30MPH RANGE. SKIES WILL
BE MOSTLY SUNNY THROUGH MUCH OF THE DAY, WITH AN INCREASE IN
CLOUDS NOTED ACROSS THE FAR SOUTH DURING THE AFTERNOON AS A
MID-LEVEL SHORT-WAVE APPROACHES FROM THE WEST. ALL MODELS ARE
DEVELOPING SCATTERED SHOWERS/THUNDER IN ADVANCE OF THIS WAVE, BUT
PRIMARILY KEEP THE ACTIVITY JUST SOUTH OF THE CWA. HIGHER-RES
MODELS SUCH AS THE HRRR ARE SLIGHTLY FURTHER NORTH, SO HAVE OPTED
TO INCLUDE SLIGHT CHANCE POPS FOR SHOWERS SOUTH OF I-70 THIS
AFTERNOON. THANKS TO INCREASED SUNSHINE, HIGH TEMPERATURES WILL
BE A FEW DEGREES WARMER THAN YESTERDAY, WITH READINGS CLIMBING
INTO THE LOWER TO MIDDLE 60S.
&&
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 323 AM CDT TUE APR 21 2015
MAIN CHALLENGES IN THE EXTENDED CONTINUE TO BE FROST POTENTIAL
WEDNESDAY/THURSDAY NIGHTS, AS WELL AS, TIMING OF NEXT PRECIP EVENT
BY THE END OF THE WEEK.
DEEP UPPER LOW CURRENTLY CENTERED OVER THE WESTERN GREAT LAKES WILL
BE THE DOMINANT WEATHER FEATURE ACROSS THE MIDWEST FOR THE NEXT FEW
DAYS, RESULTING IN COOL CONDITIONS THROUGH FRIDAY. AS A PIECE OF
ENERGY ROTATES AROUND THE LOW, A WEAK COLD FRONT WILL DROP THROUGH
ILLINOIS TONIGHT. FORECAST SOUNDINGS ARE INITIALLY QUITE DRY:
HOWEVER, THE LATEST MODELS SHOW QUITE A BIT MORE TOP-DOWN MOISTENING
THAN IN PREVIOUS RUNS. AS A RESULT, THINK SCATTERED LIGHT SHOWERS
WILL ACCOMPANY THE FRONT TONIGHT, WITH PERHAPS A FEW SHOWERS
LINGERING INTO WEDNESDAY MORNING ACROSS THE FAR SE. ONCE THE
FRONT EXITS, CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION FOR
THE MIDDLE AND END OF THE WEEK. THE RIDGE AXIS IS PROGGED TO BE
JUST WEST OF THE MISSISSIPPI RIVER BY 12Z THURSDAY, SO AM
EXPECTING WINDS TO DIMINISH CONSIDERABLY AS THE PRESSURE GRADIENT
WEAKENS. WITH CLEAR SKIES AND LIGHT WINDS, OVERNIGHT LOWS WILL
DIP INTO THE LOWER TO MIDDLE 30S, LEADING TO FROST DEVELOPMENT
ACROSS MUCH OF THE AREA. IF SKIES REMAIN CLEAR, ANOTHER
POTENTIALLY FROSTY NIGHT WILL OCCUR THURSDAY NIGHT AS WELL.
FURTHER OUT, MODELS ARE HAVING CONSIDERABLE DIFFICULTY PINNING DOWN
THE END OF THE WEEK SYSTEM. SOLUTIONS HAVE BEEN FLIP-FLOPPING FROM
RUN TO RUN, SO OVERALL FORECAST CONFIDENCE BEYOND THURSDAY REMAINS
LOWS. THE 00Z APR 21 GFS HAS MADE A MAJOR SHIFT BACK TO A SOLUTION
IT FEATURED A COUPLE OF DAYS AGO. MEANWHILE, BOTH THE ECMWF AND GEM
SEEM TO BE HEADING IN THE OPPOSITE DIRECTION. GIVEN SO MUCH MODEL
INCONSISTENCY, PREFER TO MAKE VERY FEW CHANGES TO THE EXTENDED.
WITH CANADIAN HIGH PRESSURE INITIALLY IN PLACE ACROSS THE MIDWEST ON
WEDNESDAY/THURSDAY, STILL THINK A SLOWER ARRIVAL OF THE NEXT STORM
SYSTEM MAKES SENSE. AS A RESULT, HAVE KEPT FRIDAY DRY DESPITE WHAT
THE ECMWF AND GEM ARE ADVERTISING. HAVE INTRODUCED POPS FRIDAY
NIGHT INTO SATURDAY AS A SYSTEM OVER THE DESERT SOUTHWEST GETS
KICKED EASTWARD. STILL QUITE A BIT OF UNCERTAINTY CONCERNING HOW
FAR NORTH PRECIP WILL SPREAD, BUT HAVE STUCK WITH PREVIOUS THINKING
OF KEEPING HIGHEST POPS FOCUSED ACROSS THE SOUTHERN HALF OF THE CWA.
THIS IS IN GOOD AGREEMENT WITH THE LATEST GFS, BUT NOT THE ECMWF/GEM
WHICH BOTH FOCUS PRECIP MUCH FURTHER NORTH. ONCE THE SYSTEM EXITS,
A RETURN TO DRY WEATHER IS ANTICIPATED FOR SUNDAY BEFORE ANOTHER
FAST-MOVING NORTHERN-STREAM WAVE POTENTIALLY BRINGS A FEW SHOWERS
BACK INTO THE PICTURE BY MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1158 PM CDT MON APR 20 2015
WINDS UP OVERNIGHT, DRIVEN PARTIALLY BY A PRESSURE GRADIENT STILL
IN PLACE IN THE WAKE OF THE EXITING LOW PRESSURE SYSTEM TO THE
NORTH/NORTHEAST. WINDS REMAIN GUSTY TOMORROW, GUSTING IN EXCESS OF
30-35KTS THROUGH THE AFTERNOON WITH DAYTIME HEATING/MIXING.
DIFFERING MOISTURE PROFILES PUT CU POTENTIAL AT 5KFT IN THE EAST
AND HIGHER IN THE WEST...ALTHOUGH THE CU RULE IS ACTUALLY
MINIMIZED IN A RIDGE THROUGH CENTRAL ILLINOIS. QUICK WAVE THROUGH
THE REGION WILL BRING THREAT OF PRECIP BUT COVERAGE IS LIKELY TO
BE SCATTERED AT THIS POINT AND MOSTLY NORTH AND SOUTH OF THE
AREA...SO VCSH FOR BMI AND PIA IS ALL THAT IS MENTIONED IN THE
TAFS FOR NOW.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR ILZ027>031-037-038-043>046.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
113 PM EDT TUE APR 21 2015
.SYNOPSIS...
ISSUED AT 107 PM EDT TUE APR 21 2015
STRONG WESTERLY WINDS WILL PERSIST THROUGH THE AFTERNOON WITH GUSTS
AS HIGH AS 45 MPH. THERE IS ALSO A SLIGHT CHANCE FOR A FEW
AFTERNOON RAIN SHOWERS...MAINLY ALONG AND NORTH OF THE TOLL ROAD.
HIGHS TODAY WILL BE IN THE MID 50S WITH LOWS TONIGHT IN THE MID
30S. COOL AND DRY CONDITIONS WILL THEN CONTINUE THROUGH THE REST
OF THIS WEEK.
&&
.UPDATE...
ISSUED AT 107 PM EDT TUE APR 21 2015
WIND ADVISORY GENERALLY ON TRACK WITH SEVERAL LOCATIONS SEEING
EITHER SUSTAINED AND/OR GUSTS NEAR OR JUST ABOVE CRITERIA. FEW
POCKETS UPSTREAM OF WIND GUSTS OVER 50 MPH WHICH MAY STILL MOVE IN
MID TO LATE AFTERNOON AS A COLD FRONT SWEEPS THROUGH AND AIDS
MIXING EVEN MORE. SCATTERED SHOWERS RAPIDLY DEVELOPED ACROSS FAR
NE INDIANA INTO NW OHIO BUT ARE DEPARTING JUST AS FAST. ADDITIONAL
SHOWERS ARE POSSIBLE ACROSS THE NE HALF OR SO OF THE AREA WITH A
NUDGE SOUTHWARD IN POPS WARRANTED IN UPDATE. THE STRONGEST SHOWERS
COULD PRODUCE SMALL HAIL AND LOCALLY INCREASE WIND SPEEDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM EDT TUE APR 21 2015
STRONG WINDS WILL BE THE FORECAST MESSAGE OF THE DAY. STILL A
DECENT HEIGHT/PRESSURE GRADIENT IN PLACE BETWEEN LARGELY
BAROTROPIC LOW PRESSURE NEAR JAMES BAY AND ANTICYCLONE ACROSS THE
GULF COAST. HOWEVER...THE REAL KEY FACTOR FOR GUSTY WINDS WILL BE
VERY DEEP BOUNDARY LAYER MIXING. COMBINATION OF DRY AIR ADVECTION
NEAR THE SURFACE...STRONG LATE APRIL SUN...AND VERY COLD
CONDITIONS ALOFT WILL SET THE STAGE FOR MIXING HEIGHTS TO CLIMB TO
AT LEAST 6 KFT WITH SOME MODELS (GFS AND RAP) SUGGESTING BOUNDARY
LAYER DEPTHS WILL APPROACH 9 KFT. WIND SPEEDS AT THOSE LEVELS WILL
BE IN THE 40-50 KT RANGE. NO DOUBT IT WILL BE WINDY BUT THE
QUESTION IS WILL IT REACH ADVISORY CRITERIA (39KTS/45MPH). LACK OF
GOOD ISENTROPIC DESCENT TO FORCE DOWN HIGHER MOMENTUM AIR IS
CONCERNING...AS IS LACK OF ISALLOBARIC COMPONENT. ALWAYS SOME
QUESTION AS TO HOW EFFICIENT TURBULENT MIXING ALONE WILL BE IN
PRODUCING HIGHER GUSTS AT THE SURFACE....ESPECIALLY WHEN MIXING
OVER SUCH A DEEP LAYER...AND NAM (AS WELL AS SOME OTHER HI-RES
MODEL) SOUNDINGS ARE NOT QUITE AS BULLISH. THAT BEING SAID...MOST
MODELS SHOW WIND SPEEDS AROUND 40 KTS AT THE TOP OF THE BOUNDARY
LAYER AND SEVERAL INDICATE MIXING INTO SOME 50 KT WINDS. GIVEN
THIS AND POTENTIAL FOR CONVECTIVE SHOWERS TO ENHANCE DOWNWARD
MOMENTUM TRANSFER (SEE NEXT PARAGRAPH)...FEEL IT IS PRUDENT TO GO
AHEAD AND PULL THE TRIGGER ON A WIND ADVISORY. EVEN IF MORE
IMPRESSIVE GFS AND RAP FORECAST SOUNDINGS/WIND FIELDS DONT
VERIFY...WILL STILL BE CLOSE TO ADVISORY CRITERIA.
500MB TEMPS BELOW -30C WILL SUPPORT A VERY DEEP LAYER OF STEEP LAPSE
RATES DURING THE DAY TODAY. DEGREE OF MOISTURE AVAILABLE IS VERY
MUCH IN QUESTION AND REMAINS A SIGNIFICANT LIMITING FACTOR FOR
PRECIP DEVELOPMENT BUT SHREDS OF VORTICITY ROTATING AROUND LARGE
CLOSED LOW COULD PROVIDE JUST ENOUGH MIDLEVEL CONVERGENCE/SATURATION
TO WARRANT A FEW ISOLATED SPRINKLES/SHOWERS...MAINLY IN OUR NORTHERN
COUNTIES. INHERITED FORECAST OF LOW CHANCE POPS ACROSS THE NORTH
SEEMS REASONABLE. IF ANY SHOWERS DO MANAGE TO DEVELOP...STRONG
NEGATIVE BUOYANCY DUE TO EVAPORATIONAL COOLING WITH "INVERTED V"
SOUNDING COULD HELP MIX DOWN SOME HIGHER GUSTS. COULD ALSO BE SOME
SMALL HAIL GIVEN COLD/DRY AIRMASS BUT VERY MARGINAL CAPE VALUES
SUGGEST ANY SUBSTANTIVE UPDRAFTS WILL BE FEW AND FAR BETWEEN.
SLIGHT CHANCE FOR SOME PRECIP LATE TONIGHT AS A MORE POTENT
SHORTWAVE SWINGS THROUGH THE AREA. MOST MODELS KEEP LOW LEVEL FGEN
RESPONSE JUST TO OUR SOUTH THOUGH AND WILL HOLD WITH A LOW CHANCE
POP. DESPITE VERY COLD AIR ALOFT...TEMPS SHOULD RECOVER INTO THE MID
50S TODAY GIVEN DEEP MIXING. LOWS TONIGHT SHOULD GENERALLY HOLD IN
THE MID 30S WITH STEADY WEST WINDS AND AT LEAST SOME CLOUDS KEEPING
THE THREAT OF FROST LOW.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM EDT TUE APR 21 2015
NEG HGT ANOMALIES WILL PERSIST OVR SE CANADA THIS PD IN ASSOCN/W SLW
EWD MEANDER OF DEEP CUTOFF FM THE LAKES THROUGH SE CANADA. THIS
YIELDS A CONTN OF NW FLW ALOFT ACRS THE LAKES/OH VALLEY ALG W/MUCH
BLO NORMAL TEMPS AND DRY WX THIS PD.
HWVR POTENTIAL PITFALL EXISTS IN FRI NIGHT-SAT TIME FRAME W/BOTH
HANDLING/PLACEMENT OF NWWD ORIENTED MID LVL TROUGH AXIS EXTENDING
BACK INTO THE NRN PLAINS AND NEWD EJECTION OF SRN STREAM SW LOCATED
OFF THE SRN CA COAST THIS MORNING. EC ELUCIDATED THIS POSSIBILITY
FIRST LAST NIGHT AND NOW HAS GROWING SPRT FM GEM. THUS FELT IT
PRUDENT TO PLACE SOME CONFIDENCE IN ALLBLEND GUIDANCE FOR THIS
TIME PD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 107 PM EDT TUE APR 21 2015
DEEP MIXING OF STRONGER WINDS HAS BEEN A BIT SLOW TO MATERIALIZE
AT KSBN...BUT STILL PLENTY TO CAUSE ISSUES. AT KFWA TAFS PRETTY
MUCH ON TRACK. WINDS WILL SUBSIDE THIS EVENING BUT STILL REMAIN
WESTERLY AND THEN PICK UP AGAIN ON WEDNESDAY. A FEW SHOWERS MAY
PASS NEAR EITHER AIRPORT THROUGH LATE AFTERNOON...BUT LITTLE
OVERALL IMPACT EXPECTED.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WIND ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
INZ003>009-012>018-020-022>027-032>034.
MI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ077>081.
OH...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ001-002-004-005-
015-016-024-025.
LM...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 4 PM EDT
WEDNESDAY FOR LMZ046.
GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LMZ046.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT WEDNESDAY FOR LMZ043.
&&
$$
UPDATE...FISHER
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...T
AVIATION...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
556 AM EDT TUE APR 21 2015
.SYNOPSIS...
ISSUED AT 356 AM EDT TUE APR 21 2015
STRONG WESTERLY WINDS ARE EXPECTED TODAY WITH GUSTS AS HIGH AS 45
MPH. THERE IS ALSO A SLIGHT CHANCE FOR A FEW AFTERNOON RAIN
SHOWERS...MAINLY ALONG AND NORTH OF THE TOLL ROAD. HIGHS TODAY WILL
BE IN THE MID 50S WITH LOWS TONIGHT IN THE MID 30S. COOL AND DRY
CONDITIONS WILL THEN CONTINUE THROUGH THE REST OF THIS WEEK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM EDT TUE APR 21 2015
STRONG WINDS WILL BE THE FORECAST MESSAGE OF THE DAY. STILL A
DECENT HEIGHT/PRESSURE GRADIENT IN PLACE BETWEEN LARGELY
BAROTROPIC LOW PRESSURE NEAR JAMES BAY AND ANTICYCLONE ACROSS THE
GULF COAST. HOWEVER...THE REAL KEY FACTOR FOR GUSTY WINDS WILL BE
VERY DEEP BOUNDARY LAYER MIXING. COMBINATION OF DRY AIR ADVECTION
NEAR THE SURFACE...STRONG LATE APRIL SUN...AND VERY COLD
CONDITIONS ALOFT WILL SET THE STAGE FOR MIXING HEIGHTS TO CLIMB TO
AT LEAST 6 KFT WITH SOME MODELS (GFS AND RAP) SUGGESTING BOUNDARY
LAYER DEPTHS WILL APPROACH 9 KFT. WIND SPEEDS AT THOSE LEVELS WILL
BE IN THE 40-50 KT RANGE. NO DOUBT IT WILL BE WINDY BUT THE
QUESTION IS WILL IT REACH ADVISORY CRITERIA (39KTS/45MPH). LACK OF
GOOD ISENTROPIC DESCENT TO FORCE DOWN HIGHER MOMENTUM AIR IS
CONCERNING...AS IS LACK OF ISALLOBARIC COMPONENT. ALWAYS SOME
QUESTION AS TO HOW EFFICIENT TURBULENT MIXING ALONE WILL BE IN
PRODUCING HIGHER GUSTS AT THE SURFACE....ESPECIALLY WHEN MIXING
OVER SUCH A DEEP LAYER...AND NAM (AS WELL AS SOME OTHER HI-RES
MODEL) SOUNDINGS ARE NOT QUITE AS BULLISH. THAT BEING SAID...MOST
MODELS SHOW WIND SPEEDS AROUND 40 KTS AT THE TOP OF THE BOUNDARY
LAYER AND SEVERAL INDICATE MIXING INTO SOME 50 KT WINDS. GIVEN
THIS AND POTENTIAL FOR CONVECTIVE SHOWERS TO ENHANCE DOWNWARD
MOMENTUM TRANSFER (SEE NEXT PARAGRAPH)...FEEL IT IS PRUDENT TO GO
AHEAD AND PULL THE TRIGGER ON A WIND ADVISORY. EVEN IF MORE
IMPRESSIVE GFS AND RAP FORECAST SOUNDINGS/WIND FIELDS DONT
VERIFY...WILL STILL BE CLOSE TO ADVISORY CRITERIA.
500MB TEMPS BELOW -30C WILL SUPPORT A VERY DEEP LAYER OF STEEP LAPSE
RATES DURING THE DAY TODAY. DEGREE OF MOISTURE AVAILABLE IS VERY
MUCH IN QUESTION AND REMAINS A SIGNIFICANT LIMITING FACTOR FOR
PRECIP DEVELOPMENT BUT SHREDS OF VORTICITY ROTATING AROUND LARGE
CLOSED LOW COULD PROVIDE JUST ENOUGH MIDLEVEL CONVERGENCE/SATURATION
TO WARRANT A FEW ISOLATED SPRINKLES/SHOWERS...MAINLY IN OUR NORTHERN
COUNTIES. INHERITED FORECAST OF LOW CHANCE POPS ACROSS THE NORTH
SEEMS REASONABLE. IF ANY SHOWERS DO MANAGE TO DEVELOP...STRONG
NEGATIVE BUOYANCY DUE TO EVAPORATIONAL COOLING WITH "INVERTED V"
SOUNDING COULD HELP MIX DOWN SOME HIGHER GUSTS. COULD ALSO BE SOME
SMALL HAIL GIVEN COLD/DRY AIRMASS BUT VERY MARGINAL CAPE VALUES
SUGGEST ANY SUBSTANTIVE UPDRAFTS WILL BE FEW AND FAR BETWEEN.
SLIGHT CHANCE FOR SOME PRECIP LATE TONIGHT AS A MORE POTENT
SHORTWAVE SWINGS THROUGH THE AREA. MOST MODELS KEEP LOW LEVEL FGEN
RESPONSE JUST TO OUR SOUTH THOUGH AND WILL HOLD WITH A LOW CHANCE
POP. DESPITE VERY COLD AIR ALOFT...TEMPS SHOULD RECOVER INTO THE MID
50S TODAY GIVEN DEEP MIXING. LOWS TONIGHT SHOULD GENERALLY HOLD IN
THE MID 30S WITH STEADY WEST WINDS AND AT LEAST SOME CLOUDS KEEPING
THE THREAT OF FROST LOW.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM EDT TUE APR 21 2015
NEG HGT ANOMALIES WILL PERSIST OVR SE CANADA THIS PD IN ASSOCN/W SLW
EWD MEANDER OF DEEP CUTOFF FM THE LAKES THROUGH SE CANADA. THIS
YIELDS A CONTN OF NW FLW ALOFT ACRS THE LAKES/OH VALLEY ALG W/MUCH
BLO NORMAL TEMPS AND DRY WX THIS PD.
HWVR POTENTIAL PITFALL EXISTS IN FRI NIGHT-SAT TIME FRAME W/BOTH
HANDLING/PLACEMENT OF NWWD ORIENTED MID LVL TROUGH AXIS EXTENDING
BACK INTO THE NRN PLAINS AND NEWD EJECTION OF SRN STREAM SW LOCATED
OFF THE SRN CA COAST THIS MORNING. EC ELUCIDATED THIS POSSIBILITY
FIRST LAST NIGHT AND NOW HAS GROWING SPRT FM GEM. THUS FELT IT
PRUDENT TO PLACE SOME CONFIDENCE IN ALLBLEND GUIDANCE FOR THIS
TIME PD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 556 AM EDT TUE APR 21 2015
DEEP MIXING AND TIGHT GRADIENT IN THE WAKE OF LOW PRESSURE OVER
ONTARIO WILL LEAD TO STRONG WESTERLY WINDS TODAY. WIND SPEEDS AT
THE TOP OF THE BOUNDARY LAYER ARE IN THE 40-50 KT RANGE SO EXPECT
GUSTS UP TO AROUND 40 KTS FROM LATE MORNING THROUGH THE AFTERNOON.
DRY AIR AND DEEP MIXING WILL HOWEVER KEEP CEILINGS ABOVE 5 KFT
THROUGH THE PERIOD. SLIGHT CHANCE OF A SPRINKLE/SHOWER AT KSBN
BUT NO IMPACT EXPECTED.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WIND ADVISORY FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM
EDT /7 PM CDT/ THIS EVENING FOR INZ003>009-012>018-020-
022>027-032>034.
MI...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR MIZ077>081.
OH...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR OHZ001-002-004-005-015-016-024-025.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR LMZ046.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 4 PM EDT
WEDNESDAY FOR LMZ046.
GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR LMZ046.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT WEDNESDAY FOR LMZ043.
&&
$$
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...T
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
356 AM EDT TUE APR 21 2015
.SYNOPSIS...
ISSUED AT 356 AM EDT TUE APR 21 2015
STRONG WESTERLY WINDS ARE EXPECTED TODAY WITH GUSTS AS HIGH AS 45
MPH. THERE IS ALSO A SLIGHT CHANCE FOR A FEW AFTERNOON RAIN
SHOWERS...MAINLY ALONG AND NORTH OF THE TOLL ROAD. HIGHS TODAY WILL
BE IN THE MID 50S WITH LOWS TONIGHT IN THE MID 30S. COOL AND DRY
CONDITIONS WILL THEN CONTINUE THROUGH THE REST OF THIS WEEK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM EDT TUE APR 21 2015
STRONG WINDS WILL BE THE FORECAST MESSAGE OF THE DAY. STILL A
DECENT HEIGHT/PRESSURE GRADIENT IN PLACE BETWEEN LARGELY
BAROTROPIC LOW PRESSURE NEAR JAMES BAY AND ANTICYCLONE ACROSS THE
GULF COAST. HOWEVER...THE REAL KEY FACTOR FOR GUSTY WINDS WILL BE
VERY DEEP BOUNDARY LAYER MIXING. COMBINATION OF DRY AIR ADVECTION
NEAR THE SURFACE...STRONG LATE APRIL SUN...AND VERY COLD
CONDITIONS ALOFT WILL SET THE STAGE FOR MIXING HEIGHTS TO CLIMB TO
AT LEAST 6 KFT WITH SOME MODELS (GFS AND RAP) SUGGESTING BOUNDARY
LAYER DEPTHS WILL APPROACH 9 KFT. WIND SPEEDS AT THOSE LEVELS WILL
BE IN THE 40-50 KT RANGE. NO DOUBT IT WILL BE WINDY BUT THE
QUESTION IS WILL IT REACH ADVISORY CRITERIA (39KTS/45MPH). LACK OF
GOOD ISENTROPIC DESCENT TO FORCE DOWN HIGHER MOMENTUM AIR IS
CONCERNING...AS IS LACK OF ISALLOBARIC COMPONENT. ALWAYS SOME
QUESTION AS TO HOW EFFICIENT TURBULENT MIXING ALONE WILL BE IN
PRODUCING HIGHER GUSTS AT THE SURFACE....ESPECIALLY WHEN MIXING
OVER SUCH A DEEP LAYER...AND NAM (AS WELL AS SOME OTHER HI-RES
MODEL) SOUNDINGS ARE NOT QUITE AS BULLISH. THAT BEING SAID...MOST
MODELS SHOW WIND SPEEDS AROUND 40 KTS AT THE TOP OF THE BOUNDARY
LAYER AND SEVERAL INDICATE MIXING INTO SOME 50 KT WINDS. GIVEN
THIS AND POTENTIAL FOR CONVECTIVE SHOWERS TO ENHANCE DOWNWARD
MOMENTUM TRANSFER (SEE NEXT PARAGRAPH)...FEEL IT IS PRUDENT TO GO
AHEAD AND PULL THE TRIGGER ON A WIND ADVISORY. EVEN IF MORE
IMPRESSIVE GFS AND RAP FORECAST SOUNDINGS/WIND FIELDS DONT
VERIFY...WILL STILL BE CLOSE TO ADVISORY CRITERIA.
500MB TEMPS BELOW -30C WILL SUPPORT A VERY DEEP LAYER OF STEEP LAPSE
RATES DURING THE DAY TODAY. DEGREE OF MOISTURE AVAILABLE IS VERY
MUCH IN QUESTION AND REMAINS A SIGNIFICANT LIMITING FACTOR FOR
PRECIP DEVELOPMENT BUT SHREDS OF VORTICITY ROTATING AROUND LARGE
CLOSED LOW COULD PROVIDE JUST ENOUGH MIDLEVEL CONVERGENCE/SATURATION
TO WARRANT A FEW ISOLATED SPRINKLES/SHOWERS...MAINLY IN OUR NORTHERN
COUNTIES. INHERITED FORECAST OF LOW CHANCE POPS ACROSS THE NORTH
SEEMS REASONABLE. IF ANY SHOWERS DO MANAGE TO DEVELOP...STRONG
NEGATIVE BUOYANCY DUE TO EVAPORATIONAL COOLING WITH "INVERTED V"
SOUNDING COULD HELP MIX DOWN SOME HIGHER GUSTS. COULD ALSO BE SOME
SMALL HAIL GIVEN COLD/DRY AIRMASS BUT VERY MARGINAL CAPE VALUES
SUGGEST ANY SUBSTANTIVE UPDRAFTS WILL BE FEW AND FAR BETWEEN.
SLIGHT CHANCE FOR SOME PRECIP LATE TONIGHT AS A MORE POTENT
SHORTWAVE SWINGS THROUGH THE AREA. MOST MODELS KEEP LOW LEVEL FGEN
RESPONSE JUST TO OUR SOUTH THOUGH AND WILL HOLD WITH A LOW CHANCE
POP. DESPITE VERY COLD AIR ALOFT...TEMPS SHOULD RECOVER INTO THE MID
50S TODAY GIVEN DEEP MIXING. LOWS TONIGHT SHOULD GENERALLY HOLD IN
THE MID 30S WITH STEADY WEST WINDS AND AT LEAST SOME CLOUDS KEEPING
THE THREAT OF FROST LOW.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM EDT TUE APR 21 2015
NEG HGT ANOMALIES WILL PERSIST OVR SE CANADA THIS PD IN ASSOCN/W SLW
EWD MEANDER OF DEEP CUTOFF FM THE LAKES THROUGH SE CANADA. THIS
YIELDS A CONTN OF NW FLW ALOFT ACRS THE LAKES/OH VALLEY ALG W/MUCH
BLO NORMAL TEMPS AND DRY WX THIS PD.
HWVR POTENTIAL PITFALL EXISTS IN FRI NIGHT-SAT TIME FRAME W/BOTH
HANDLING/PLACEMENT OF NWWD ORIENTED MID LVL TROUGH AXIS EXTENDING
BACK INTO THE NRN PLAINS AND NEWD EJECTION OF SRN STREAM SW LOCATED
OFF THE SRN CA COAST THIS MORNING. EC ELUCIDATED THIS POSSIBILITY
FIRST LAST NIGHT AND NOW HAS GROWING SPRT FM GEM. THUS FELT IT
PRUDENT TO PLACE SOME CONFIDENCE IN ALLBLEND GUIDANCE FOR THIS
TIME PD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 130 AM EDT TUE APR 21 2015
LOW LEVEL DRY AIR ADVECTION IN THE WAKE OF LARGE CYCLONE OVER
ONTARIO WILL ENSURE VFR CONDITIONS THROUGH THE PERIOD. MAIN IMPACT
WILL BE VERY STRONG WESTERLY WINDS DURING THE DAY TODAY AS MIXING
HEIGHTS CLIMB TO AROUND 7 KFT WHERE WIND SPEEDS ARE IN THE 40-45 KT
RANGE. A FEW GUSTS TO AROUND 40 KTS ARE POSSIBLE DURING THE LATE
MORNING AND EARLY AFTERNOON. ISOLATED SHOWERS/SPRINKLES ARE ALSO
POSSIBLE AT TIMES TODAY BUT NO IMPACT ANTICIPATED.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WIND ADVISORY FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM
EDT /7 PM CDT/ THIS EVENING FOR INZ003>009-012>018-020-
022>027-032>034.
MI...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR MIZ077>081.
OH...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR OHZ001-002-004-005-015-016-024-025.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM EDT WEDNESDAY FOR LMZ043-046.
&&
$$
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...T
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
815 PM CDT WED APR 22 2015
.SYNOPSIS...
ISSUED AT 305 PM CDT WED APR 22 2015
THE MIDWEST REMAINS UNDER THE INFLUENCE OF A STACKED LOW PRESSURE
SYSTEM CENTERED OVER ONTARIO. THE MAIN SENSIBLE WEATHER IMPACT
ACROSS E IOWA/W ILLINOIS TODAY HAS BEEN THE STRONG/GUSTY NW WINDS
BETWEEN 30-40 MPH. SFC DEWPOINTS ARE VERY LOW...HOVERING IN THE
TEENS. AT 3 PM THE RH AT THE DAVENPORT AIRPORT WAS DOWN TO 18
PERCENT.
&&
.UPDATE...
ISSUED AT 812 PM CDT WED APR 22 2015
CURRENT SURFACE ANALYSIS SHOWS DEWPOINT TEMPERATURES IN THE SINGLE
DIGITS UPSTREAM IN MN. 23Z RAP HAS THESE VALUES ADVECT ACROSS THE
AREA TONIGHT. CURRENT DEWPOINT TEMPS ARE 5 TO 10 DEGREES LOWER
THAN 5 HOURS AGO. WITH THE CLEAR SKIES AND WINDS
WEAKENING...TONIGHT LOOKS LIKE A NIGHT WHERE THE BOTTOM COULD DROP
OUT. THE NEXT COUPLE OF HOURS WILL TELL A LOT ABOUT HOW COLD WE
COULD GET TONIGHT. AS SUCH...LOWERED LOWS BY 3 TO 4 DEGREES TO
HEDGE TOWARDS LOWER TEMPS. IF THE DEWPOINTS DONT CHANGE MUCH WHEN
WE DECOUPLE THEN MAY NEED TO GO EVEN LOWER. WILL MONITOR AND
DECIDE WHAT TO DO AROUND 10PM. HAVE INCLUDED THE RECORD LOWS FOR
TONIGHT AS IT COULD BE POSSIBLE THAT WE COULD SEE TEMPS CLOSE TO
THEM TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 305 PM CDT WED APR 22 2015
THIS EVENING AND TONIGHT...SFC PRESSURE GRADIENT WILL WEAKEN
DRAMATICALLY AND ATMOSPHERE WILL DECOUPLE TO SOME EXTENT. THE SFC
HIGH PRESSURE AXIS WILL STAY WEST OF THE AREA ACROSS CENTRAL
IOWA...SO WINDS AROUND 5 KTS ARE FORECAST THROUGH THE NIGHT. CLEAR
SKIES AND VERY DRY AIR WILL SET THE STAGE FOR WELL BELOW NORMAL LOW
TEMPS IN THE MID 20S TO LOWER 30S.
WITH VEGETATION GREEN-UP WELL UNDERWAY AND LOCAL KNOWLEDGE FROM IOWA
STATE UNIVERSITY THAT FRUIT TREES ARE NOW SUSCEPTIBLE TO TEMPS IN
THE UPPER 20S...WILL ISSUE A FREEZE WARNING FOR THE ENTIRE AREA.
STARTED THE WARNING AT 2 AM CDT OVER NORTHERN TWO-THIRDS OF THE
FORECAST AREA WHERE MID TO UPPER 20S ARE FORECAST...AND AT 4 AM
OVER THE SOUTHERN THIRD WHERE UPPER 20S TO LOWER 30S ARE FORECAST.
BOTH WARNING SEGMENTS WILL EXPIRE AT 8 AM CDT THURSDAY MORNING.
THURSDAY...FINALLY MUCH LIGHTER WINDS...GENERALLY UNDER 15 MPH OUT
OF THE NW. OTHERWISE MOSTLY CLEAR SKIES WILL HELP TEMPS REACH TO
NEAR 60 F ON AVG.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 305 PM CDT WED APR 22 2015
ANOTHER COLD NIGHT WILL BEGIN THE EXTENDED...AS SURFACE HIGH
PRESSURE REMAINS OVER THE AREA. WARM ADVECTION ALOFT WILL RESULT IN
CIRRUS AND POSSIBLE MID CLOUDS AFTER LATE EVENING...THUS...LOWS
SHOULD OCCUR AROUND MIDNIGHT...FOLLOWED BY STEADY OR RISING
TEMPERATURES. LOWS MAY DIP NEAR 32 IN THE EAST...BUT SHOULD HOLD IN
THE UPPER 30S TO AROUND 40 IN THE WEST 1/3.
LOOKING AT FRIDAY THROUGH THE WEEKEND...MODELS CONTINUE TO SHOW A
WINTER LIKE SYSTEM AFFECTING THE REGION...WITH A CLOSED MID LEVEL
LOW...OVER IOWA...AND SURFACE LOW IN MISSOURI. THIS SYSTEM SHOULD
PRODUCE WIDESPREAD STRATIFORM RAINS...MUCH LIKE A SNOW
EVENT...WOULD...ALONG WITH COLD TEMPERATURES AND EAST WINDS.
THUS...A DEFORMATION ZONE OF RAIN WILL LIKELY IMPACT OUR ENTIRE
CWA...BUT MOST CERTAINLY IN THE SOUTH 1/2. POPS ARE FORECAST
CATEGORICAL FRIDAY NIGHT...AND SATURDAY MORNING IN THE SOUTH TO
ACCOUNT FOR WIDESPREAD LIGHT TO MODERATE RAIN.
RAIN...EAST WINDS...AND CLOUDS WILL KEEP SATURDAY COOL...BUT ENOUGH
OF FRIDAY SHOULD SEE FILTERED SUN TO GET HIGHS BACK TO THE MID TO
UPPER 50S. SATURDAY WILL BE HELD TO THE UPPER 40S TO LOWER 50S...AND
THAT TOO COULD BE OPTIMISTIC IF THE RAINS MATERIALIZE AS PERSISTENT
AS THE GFS AND ECMWF BOTH SHOW.
FOLLOWING THIS WEEKEND RAIN SYSTEM...MODELS ARE QUICKLY SHOWING A
RETURN TO NORTHWEST FLOW ON THE WESTERN FLANK OF THE DOMINANT
EASTERN CONUS UPPER LOW. THIS COLDER THAN NORMAL PATTERN MAY STAY IN
PLACE THROUGH THE EARLY DAYS OF MAY. WHILE SOME RAIN SHOWERS WILL BE
POSSIBLE IN CLIPPER TYPE FORCING...THE MAIN IMPACTS WILL MOST
CERTAINLY BE MORE BREEZY...DEEPLY MIXED DAYS...WITH HIGHS GENERALLY
BELOW NORMAL.
ERVIN
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 647 PM CDT WED APR 22 2015
VFR CONDITIONS WILL PERSIST THROUGH THE PERIOD. WINDS WILL FINALLY
START TO SLACKEN TOMORROW. MAIN AVIATION CONCERN WILL BE THE WIND
FOR THE REST OF TONIGHT. ONCE THE SUN SETS WINDS WILL DIE OFF
DRAMATICALLY.
&&
.CLIMATE...
ISSUED AT 812 PM CDT WED APR 22 2015
RECORD LOWS FOR APR 23...
BURLINGTON ...24...1910
CEDAR RAPIDS...20...1927
DUBUQUE...22...1910
MOLINE...22...1910
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FREEZE WARNING FROM 2 AM TO 8 AM CDT THURSDAY FOR BENTON-
BUCHANAN-CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-
IOWA-JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...FREEZE WARNING FROM 2 AM TO 8 AM CDT THURSDAY FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...FREEZE WARNING FROM 2 AM TO 8 AM CDT THURSDAY FOR CLARK-SCOTLAND.
&&
$$
UPDATE...GIBBS
SYNOPSIS...UTTECH
SHORT TERM...UTTECH
LONG TERM...ERVIN
AVIATION...GIBBS
CLIMATE...GIBBS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
956 PM MDT WED APR 22 2015
.UPDATE...
ISSUED AT 952 PM MDT WED APR 22 2015
MODELS COMING INTO FAIRLY GOOD AGREEMENT WITH THE LIKELIHOOD OF
FOG DEVELOPING OVER KIT CARSON/CHEYENNE COUNTIES LATE TONIGHT AND
EARLY THURSDAY MORNING. CURRENTLY THINKING VISIBILITIES OF A MILE
OR SO ARE LIKELY...WITH SOME LOCATIONS POSSIBLY DROPPING CLOSE TO
A QUARTER MILE.
TOOK OUT THE RAINFALL CHANCES FOR THE EVENING SINCE THE STORMS
JUST WEST OF THE AREA HAVE DIED. STILL THINKING SOME DRIZZLE/LIGHT
RAINFALL IS POSSIBLE LATE TONIGHT AND EARLY TOMORROW MORNING WITH
THE FOG.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 225 PM MDT WED APR 22 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS
NORTHERN AND SOUTHERN JET STREAMS SPLIT AROUND OUR CWA...WITH WEAK
RIDGING EXTENDING FROM THE SOUTHERN PLAINS AND ACROSS THE CENTRAL
ROCKIES. PACIFIC MOISTURE PLUME IS UNDERCUTTING UPPER RIDGE WITH
WEAK SHORTWAVE TROUGHS ROTATING NORTH AND EAST THROUGH THE
SOUTHERLY STORM TRACK. AT THE SURFACE A STATIONARY FRONT HAS
SLOWLY BEGUN THE PROCESS OF MOVING EAST WITH RADAR SHOWING
CONVECTION DEVELOPING IN THE WEAKLY UNSTABLE AIR MASS BEHIND THIS
FEATURE OVER THE HIGHER TERRAIN IN COLORADO.
THIS AFTERNOON TONIGHT...INITIAL CONCERN IS ON COVERAGE AND
PROGRESS OF THUNDERSTORM ACTIVITY IN COLORADO TOWARDS OUR CWA.
GUIDANCE SHOWS INCREASING INSTABILITY IN OUR WESTERN CWA...WHICH
COULD FAVOR THIS ACTIVITY MAKING AS FAR EAST AS THE CO/KS STATE
LINE. WHILE MOST OF THIS ACTIVITY WILL BE TIED TO DAYTIME
HEATING...WAA OVERNIGHT AND NOSE OF LLJ COULD SUPPORT
THUNDERSTORM LINGERING LATE THIS EVENING...OR SHOWERS AFTER
MIDNIGHT AS INSTABILITY WANES. MID LEVELS ARE NOT PARTICULARLY
MOIST AND DESPITE VERY GOOD OVERNIGHT MOISTURE ADVECTION WITHIN
THE BOUNDARY LAYER CAP ABOVE THIS WOULD LIKELY LIMIT CONVECTIVE
POTENTIAL FOR ANY NON ELEVATED PARCELS. I KEPT SLIGHT CHANCE OF
THUNDERSTORMS IN THE EVENING WITH SHOWERS LINGERING AFTER
MIDNIGHT THROUGH THURSDAY MORNING. CONSIDERING THE NEAR SATURATED
BOUNDARY LAYER THE PRECIP SIGNAL IN GUIDANCE MAY ACTUALLY BE
DRIZZLE/FOG.
THURSDAY...NAM SOUNDINGS INDICATE POTENTIAL FOR LINGERING
STRATUS/DRIZZLE DURING THE DAY...HOWEVER OVERALL PATTERN SHOULD
SUPPORT CLEARING SKIES FROM THE WEST WITH WARMER CONDITIONS ACROSS
EASTERN COLORADO. A STRONGER SHORTWAVE TROUGH WILL BEGIN TO MOVE
INTO THE CWA FROM THE WEST WITH INCREASING THUNDERSTORM CHANCES
ONCE AGAIN IN EASTERN COLORADO WHERE BETTER INSTABILITY IS
ADVERTISED ALONG WITH STRONGER LIFT. CONFIDENCE WAS HIGH ENOUGH
TO KEEP CHANCE POPS IN PLACE LATE THURSDAY AFTERNOON. HIGH
TEMPERATURES THURSDAY WILL BE TRICKY AND HIGHLY DEPENDENT ON
STRATUS CLEARING. HIGHS NEAR 70F (MAINLY IN THE WEST) ARE POSSIBLE
WHERE BEST CHANCE FOR CLEAR SKIES IS CURRENTLY ANTICIPATED.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 232 PM MDT WED APR 22 2015
THE UPPER RIDGE AXIS EXTENDING FROM THE GULF OF MEXICO THROUGH
THE NORTHERN HIGH PLAINS FLATTENS SOMEWHAT LATE THURSDAY INTO
THURSDAY NIGHT AS A SHORT WAVE TROUGH MOVES OUT OF THE SOUTHWEST
U.S. AND OVER THE CENTRAL PLAINS THURSDAY NIGHT. THE LEE SURFACE
TROUGH ALONG THE FRONT RANGE THAT DEEPENS IN RESPONSE TO THE UPPER
SHORT WAVE TROUGH HAS GOOD SOUTHEASTERLY FLOW AHEAD OF IT THAT
WILL BRING AMPLE GULF MOISTURE INTO THE REGION. SCATTERED STRONG
THUNDERSTORMS ARE POSSIBLE ACROSS THE FORECAST AREA THURSDAY NIGHT
AS A RESULT
THE MAIN UPPER TROUGH AXIS BEGINS TO LIFT OUT ACROSS THE
4-CORNERS REGION AND INTO THE CENTRAL AND SOUTHERN HIGH PLAINS
REGION BY FRIDAY AFTERNOON...WITH THE CENTROID OF THE TROUGH
MOVING OVER E CO/NW KS. DEWPOINTS IN THE 40S ACROSS THE AREA ON
THURSDAY AND THURSDAY NIGHT WILL INCREASE INTO THE LOWER 50S
ACROSS MAINLY THE EASTERN PORTION OF THE FORECAST AREA WHILE DRYER
AIR MOVES INTO THE WEST AS THE TROUGH MOVES EAST AND FORMS A
CLOSED LOW THAT MOVES ACROSS SOUTHERN KANSAS FRIDAY EVENING. WITH
AN INSTABILITY AXIS PRESENT OVER CENTRAL KANSAS...IT IS POSSIBLE
THE FORECAST AREA COULD SEE SOME STRONG TO SEVERE THUNDERSTORMS
MAINLY ACROSS THE FAR EASTERN SECTIONS THAT WILL BECOME MORE
WIDESPREAD AND STRONGER OVERNIGHT AS THEY MOVE FURTHER TO THE
EAST.
SHORT WAVE RIDGING IS EXPECTED BETWEEN THE EXITING TROUGH AS IT
LIFTS OUT OF THE REGION AND THE NEXT UPPER TROUGH THAT STARTS TO
DEEPEN OVER THE INTERMOUNTAIN WEST BETWEEN SATURDAY AND SATURDAY
EVENING. MODEL SOLUTIONS HAVE A LOW CENTER CONSOLIDATING AND
MOVING QUICKLY ACROSS NEW MEXICO SUNDAY EVENING. THEN AS MODEL
SOLUTIONS BEGIN TO DIVERGE TO A GREATER DEGREE...THE LOW SLOWS AND
ENDS UP SOMEWHERE OVER E OKLAHOMA/E TEXAS BY TUESDAY MORNING AS A
BLOCKING HIGH AMPLIFIES OVER THE WESTERN UNITED SATES. THAT RIDGE
MOVES OVER THE ROCKIES AND HIGH PLAINS REGION BY WEDNESDAY
EVENING. THE WEEKEND AND FIRST PART OF NEXT WEEK WILL REMAIN
UNSETTLED WITH SCATTERED THUNDERSTORMS POSSIBLE ACROSS THE AREA AS
THE LOW MOVES ACROSS THE SOUTHERN PLAINS. DRYER AND WARMER
CONDITIONS ARE ANTICIPATED BY MID-WEEK AS SURFACE HIGH PRESSURE
AND THE RIDGE ALOFT MOVE OVER THE HIGH PLAINS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 552 PM MDT WED APR 22 2015
VFR TO IFR CONDITIONS FORECAST FOR THE 0Z TAFS. DURING THE
OVERNIGHT HOURS THE LOW LEVEL JET STRENGTHENS WHICH WILL LEAD TO
SOME LLWS DEVELOPING. SINCE LLWS HAS DEVELOPED THE LAST TWO
NIGHTS...USED THE HEIGHT/SPEED FROM THOSE NIGHTS FOR THE TAFS.
OTHERWISE LATE TONIGHT IFR/MVFR CEILINGS WILL MOVE IN FROM THE
SOUTH- SOUTHWEST FIRST FOR KGLD THEN KMCK. THE CEILINGS WILL LIFT
FOR BOTH SITES SOME DURING THE AFTERNOON THEN DECLINE TOMORROW
EVENING.
IN ADDITION THERE WILL BE SOME FOG WEST OF KGLD PRIMARILY. AM ANTICIPATING
SOME MINIMAL VISIBILITY REDUCTION FOR KGLD AT THIS TIME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
602 PM MDT WED APR 22 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 225 PM MDT WED APR 22 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS
NORTHERN AND SOUTHERN JET STREAMS SPLIT AROUND OUR CWA...WITH WEAK
RIDGING EXTENDING FROM THE SOUTHERN PLAINS AND ACROSS THE CENTRAL
ROCKIES. PACIFIC MOISTURE PLUME IS UNDERCUTTING UPPER RIDGE WITH
WEAK SHORTWAVE TROUGHS ROTATING NORTH AND EAST THROUGH THE
SOUTHERLY STORM TRACK. AT THE SURFACE A STATIONARY FRONT HAS
SLOWLY BEGUN THE PROCESS OF MOVING EAST WITH RADAR SHOWING
CONVECTION DEVELOPING IN THE WEAKLY UNSTABLE AIR MASS BEHIND THIS
FEATURE OVER THE HIGHER TERRAIN IN COLORADO.
THIS AFTERNOON TONIGHT...INITIAL CONCERN IS ON COVERAGE AND
PROGRESS OF THUNDERSTORM ACTIVITY IN COLORADO TOWARDS OUR CWA.
GUIDANCE SHOWS INCREASING INSTABILITY IN OUR WESTERN CWA...WHICH
COULD FAVOR THIS ACTIVITY MAKING AS FAR EAST AS THE CO/KS STATE
LINE. WHILE MOST OF THIS ACTIVITY WILL BE TIED TO DAYTIME
HEATING...WAA OVERNIGHT AND NOSE OF LLJ COULD SUPPORT
THUNDERSTORM LINGERING LATE THIS EVENING...OR SHOWERS AFTER
MIDNIGHT AS INSTABILITY WANES. MID LEVELS ARE NOT PARTICULARLY
MOIST AND DESPITE VERY GOOD OVERNIGHT MOISTURE ADVECTION WITHIN
THE BOUNDARY LAYER CAP ABOVE THIS WOULD LIKELY LIMIT CONVECTIVE
POTENTIAL FOR ANY NON ELEVATED PARCELS. I KEPT SLIGHT CHANCE OF
THUNDERSTORMS IN THE EVENING WITH SHOWERS LINGERING AFTER
MIDNIGHT THROUGH THURSDAY MORNING. CONSIDERING THE NEAR SATURATED
BOUNDARY LAYER THE PRECIP SIGNAL IN GUIDANCE MAY ACTUALLY BE
DRIZZLE/FOG.
THURSDAY...NAM SOUNDINGS INDICATE POTENTIAL FOR LINGERING
STRATUS/DRIZZLE DURING THE DAY...HOWEVER OVERALL PATTERN SHOULD
SUPPORT CLEARING SKIES FROM THE WEST WITH WARMER CONDITIONS ACROSS
EASTERN COLORADO. A STRONGER SHORTWAVE TROUGH WILL BEGIN TO MOVE
INTO THE CWA FROM THE WEST WITH INCREASING THUNDERSTORM CHANCES
ONCE AGAIN IN EASTERN COLORADO WHERE BETTER INSTABILITY IS
ADVERTISED ALONG WITH STRONGER LIFT. CONFIDENCE WAS HIGH ENOUGH
TO KEEP CHANCE POPS IN PLACE LATE THURSDAY AFTERNOON. HIGH
TEMPERATURES THURSDAY WILL BE TRICKY AND HIGHLY DEPENDENT ON
STRATUS CLEARING. HIGHS NEAR 70F (MAINLY IN THE WEST) ARE POSSIBLE
WHERE BEST CHANCE FOR CLEAR SKIES IS CURRENTLY ANTICIPATED.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 232 PM MDT WED APR 22 2015
THE UPPER RIDGE AXIS EXTENDING FROM THE GULF OF MEXICO THROUGH
THE NORTHERN HIGH PLAINS FLATTENS SOMEWHAT LATE THURSDAY INTO
THURSDAY NIGHT AS A SHORT WAVE TROUGH MOVES OUT OF THE SOUTHWEST
U.S. AND OVER THE CENTRAL PLAINS THURSDAY NIGHT. THE LEE SURFACE
TROUGH ALONG THE FRONT RANGE THAT DEEPENS IN RESPONSE TO THE UPPER
SHORT WAVE TROUGH HAS GOOD SOUTHEASTERLY FLOW AHEAD OF IT THAT
WILL BRING AMPLE GULF MOISTURE INTO THE REGION. SCATTERED STRONG
THUNDERSTORMS ARE POSSIBLE ACROSS THE FORECAST AREA THURSDAY NIGHT
AS A RESULT
THE MAIN UPPER TROUGH AXIS BEGINS TO LIFT OUT ACROSS THE
4-CORNERS REGION AND INTO THE CENTRAL AND SOUTHERN HIGH PLAINS
REGION BY FRIDAY AFTERNOON...WITH THE CENTROID OF THE TROUGH
MOVING OVER E CO/NW KS. DEWPOINTS IN THE 40S ACROSS THE AREA ON
THURSDAY AND THURSDAY NIGHT WILL INCREASE INTO THE LOWER 50S
ACROSS MAINLY THE EASTERN PORTION OF THE FORECAST AREA WHILE DRYER
AIR MOVES INTO THE WEST AS THE TROUGH MOVES EAST AND FORMS A
CLOSED LOW THAT MOVES ACROSS SOUTHERN KANSAS FRIDAY EVENING. WITH
AN INSTABILITY AXIS PRESENT OVER CENTRAL KANSAS...IT IS POSSIBLE
THE FORECAST AREA COULD SEE SOME STRONG TO SEVERE THUNDERSTORMS
MAINLY ACROSS THE FAR EASTERN SECTIONS THAT WILL BECOME MORE
WIDESPREAD AND STRONGER OVERNIGHT AS THEY MOVE FURTHER TO THE
EAST.
SHORT WAVE RIDGING IS EXPECTED BETWEEN THE EXITING TROUGH AS IT
LIFTS OUT OF THE REGION AND THE NEXT UPPER TROUGH THAT STARTS TO
DEEPEN OVER THE INTERMOUNTAIN WEST BETWEEN SATURDAY AND SATURDAY
EVENING. MODEL SOLUTIONS HAVE A LOW CENTER CONSOLIDATING AND
MOVING QUICKLY ACROSS NEW MEXICO SUNDAY EVENING. THEN AS MODEL
SOLUTIONS BEGIN TO DIVERGE TO A GREATER DEGREE...THE LOW SLOWS AND
ENDS UP SOMEWHERE OVER E OKLAHOMA/E TEXAS BY TUESDAY MORNING AS A
BLOCKING HIGH AMPLIFIES OVER THE WESTERN UNITED SATES. THAT RIDGE
MOVES OVER THE ROCKIES AND HIGH PLAINS REGION BY WEDNESDAY
EVENING. THE WEEKEND AND FIRST PART OF NEXT WEEK WILL REMAIN
UNSETTLED WITH SCATTERED THUNDERSTORMS POSSIBLE ACROSS THE AREA AS
THE LOW MOVES ACROSS THE SOUTHERN PLAINS. DRYER AND WARMER
CONDITIONS ARE ANTICIPATED BY MID-WEEK AS SURFACE HIGH PRESSURE
AND THE RIDGE ALOFT MOVE OVER THE HIGH PLAINS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 552 PM MDT WED APR 22 2015
VFR TO IFR CONDITIONS FORECAST FOR THE 0Z TAFS. DURING THE
OVERNIGHT HOURS THE LOW LEVEL JET STRENGTHENS WHICH WILL LEAD TO
SOME LLWS DEVELOPING. SINCE LLWS HAS DEVELOPED THE LAST TWO
NIGHTS...USED THE HEIGHT/SPEED FROM THOSE NIGHTS FOR THE TAFS.
OTHERWISE LATE TONIGHT IFR/MVFR CEILINGS WILL MOVE IN FROM THE
SOUTH- SOUTHWEST FIRST FOR KGLD THEN KMCK. THE CEILINGS WILL LIFT
FOR BOTH SITES SOME DURING THE AFTERNOON THEN DECLINE TOMORROW
EVENING.
IN ADDITION THERE WILL BE SOME FOG WEST OF KGLD PRIMARILY. AM ANTICIPATING
SOME MINIMAL VISIBILITY REDUCTION FOR KGLD AT THIS TIME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1247 PM CDT Tue Apr 21 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 300 AM CDT TUE APR 21 2015
Deep upper low over the Great Lakes was making slow eastward
progress early this morning with likely a few small scale waves
rotating around it through the Northern and Central Plains. Periodic
mid cloud was present over the local area via isentropic upglide
from rather brisk and backed mid level winds. At least minor amounts
of EPV along the moist layer allowing some showers to form aloft,
with weak returns on radar showing some very light precip reaching
to the lower troposphere. HRRR and RAP runs quite similar to some
4km WRF runs with light precip forming over central Kansas in the
next few hours, with latest IR imagery indicating recent cloud
development there. All nearby 0Z soundings measured 850mb dewpoint
depressions around 12C, making measurable amounts hard to imagine in
this activity. A somewhat more unstable airmass develops over the
southeast quarter of Kansas this afternoon with weak surface
convergence. Will maintain small storm chances with still minor
isentropic lift and weak wave potential in place. The stronger wind
fields aloft could lead to some storm organization along with CAPE
around 500 J/kg and dry adiabatic low level lapse rates to produce a
very small threat for severe wind and hail in the mid afternoon to
early evening. Areas outside of storms could also see a few rather
strong wind gusts with mixing depths reaching 7000-10000ft AGL
though some veering remains through the column. The still dry
airmass and gusty winds lead to elevated fire danger in western
locations this afternoon.
Cold front via a stronger wave rotating around the low arrives this
evening and makes quick south progress through the state tonight.
Moisture, though modest, will continue to pool ahead of this front
for some storm chances through much of the night in the southern
zones, with typical diurnal trends allowing severe concerns to
diminish. Models are allowing the boundary layer to decouple fairly
quickly behind the front, but am somewhat skeptical of this given
the baroclinic zone they advertise. If winds can fall quicker than
expected, fairly clear skies could present a frost concern, but even
if they do the window of cold and calm conditions for formation
should be rather limited. Will mention patchy frost in far north
where concern is highest.
.LONG TERM...(Wednesday through Monday)
Issued at 300 AM CDT TUE APR 21 2015
Eastern Kansas remains on the southwest side of an upper surface
high for Wednesday, keeping high temperatures around 60 for most
of the area. Have kept rain chances out of the southern areas with
better chances south. Dry conditions continue Wednesday night into
Thursday, with lows in the upper 30s to near 40 and highs climbing
toward the middle 60s Thursday.
Upper pattern starts to shift Thursday night as shortwave ridge
noses out of the southern plains into our area, ahead of an upper
trof lifting northeast out of the four corners region. Initial
sensible weather impacts should be warmer lows in the 40s near 50
Thursday night with some showers possible after midnight as low
level jet makes a return over the area. Latest EC appears to be
trending toward the GFS solution for this shortwave as it moves
into the plains, taking a faster track and developing the warm
front from the surface low out into eastern or southeast Kansas.
GFS keeps the boundary south of the area and would make for cloudy
cool and rainy conditions area wide for Friday and Saturday night,
and with EC solutions also trending this way, have gone with
forecast as such.
Southern branch of the upper jet takes the shortwave trof east of
the area rather quickly on Saturday, with rain ending sometime
during the morning hours. Cooler high pressure once again noses
into the area behind the departing low and holds temperatures in
the low 60s, followed by overnight lows in the 40s. Highs on
Sunday rise a bit more into the middle 60s, and have kept rain
chances relegated to north and west while surface high continues
over the east. Another front progged to move across the area
Sunday night with northwest flow aloft returning on Monday.
Current forecast is for highs near 70, but this will depend on how
strong the front and wave are as to how much cooler air it does,
or does not, bring southward.
&&
.AVIATION...(For the 18Z TAFs through 18Z Wednesday Afternoon)
Issued at 1245 PM CDT TUE APR 21 2015
VFR conditions are expected the entire period with gusty winds
throughout the afternoon. Mid-level clouds will move south over the
area tonight as a frontal passage veers E winds N/NE after 04Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...67
AVIATION...Heller
AREA FORECAST DISCUSSION
NWS TOPEKA KS
649 AM CDT Tue Apr 21 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 300 AM CDT TUE APR 21 2015
Deep upper low over the Great Lakes was making slow eastward
progress early this morning with likely a few small scale waves
rotating around it through the Northern and Central Plains. Periodic
mid cloud was present over the local area via isentropic upglide
from rather brisk and backed mid level winds. At least minor amounts
of EPV along the moist layer allowing some showers to form aloft,
with weak returns on radar showing some very light precip reaching
to the lower troposphere. HRRR and RAP runs quite similar to some
4km WRF runs with light precip forming over central Kansas in the
next few hours, with latest IR imagery indicating recent cloud
development there. All nearby 0Z soundings measured 850mb dewpoint
depressions around 12C, making measurable amounts hard to imagine in
this activity. A somewhat more unstable airmass develops over the
southeast quarter of Kansas this afternoon with weak surface
convergence. Will maintain small storm chances with still minor
isentropic lift and weak wave potential in place. The stronger wind
fields aloft could lead to some storm organization along with CAPE
around 500 J/kg and dry adiabatic low level lapse rates to produce a
very small threat for severe wind and hail in the mid afternoon to
early evening. Areas outside of storms could also see a few rather
strong wind gusts with mixing depths reaching 7000-10000ft AGL
though some veering remains through the column. The still dry
airmass and gusty winds lead to elevated fire danger in western
locations this afternoon.
Cold front via a stronger wave rotating around the low arrives this
evening and makes quick south progress through the state tonight.
Moisture, though modest, will continue to pool ahead of this front
for some storm chances through much of the night in the southern
zones, with typical diurnal trends allowing severe concerns to
diminish. Models are allowing the boundary layer to decouple fairly
quickly behind the front, but am somewhat skeptical of this given
the baroclinic zone they advertise. If winds can fall quicker than
expected, fairly clear skies could present a frost concern, but even
if they do the window of cold and calm conditions for formation
should be rather limited. Will mention patchy frost in far north
where concern is highest.
.LONG TERM...(Wednesday through Monday)
Issued at 300 AM CDT TUE APR 21 2015
Eastern Kansas remains on the southwest side of an upper surface
high for Wednesday, keeping high temperatures around 60 for most
of the area. Have kept rain chances out of the southern areas with
better chances south. Dry conditions continue Wednesday night into
Thursday, with lows in the upper 30s to near 40 and highs climbing
toward the middle 60s Thursday.
Upper pattern starts to shift Thursday night as shortwave ridge
noses out of the southern plains into our area, ahead of an upper
trof lifting northeast out of the four corners region. Initial
sensible weather impacts should be warmer lows in the 40s near 50
Thursday night with some showers possible after midnight as low
level jet makes a return over the area. Latest EC appears to be
trending toward the GFS solution for this shortwave as it moves
into the plains, taking a faster track and developing the warm
front from the surface low out into eastern or southeast Kansas.
GFS keeps the boundary south of the area and would make for cloudy
cool and rainy conditions area wide for Friday and Saturday night,
and with EC solutions also trending this way, have gone with
forecast as such.
Southern branch of the upper jet takes the shortwave trof east of
the area rather quickly on Saturday, with rain ending sometime
during the morning hours. Cooler high pressure once again noses
into the area behind the departing low and holds temperatures in
the low 60s, followed by overnight lows in the 40s. Highs on
Sunday rise a bit more into the middle 60s, and have kept rain
chances relegated to north and west while surface high continues
over the east. Another front progged to move across the area
Sunday night with northwest flow aloft returning on Monday.
Current forecast is for highs near 70, but this will depend on how
strong the front and wave are as to how much cooler air it does,
or does not, bring southward.
&&
.AVIATION...(For the 12Z TAFs through 12Z Wednesday Morning)
Issued at 649 AM CDT TUE APR 21 2015
VFR conditions anticipated. Periods of mid cloud should dominate
with a small chance for -SHRA through much of the forecast, though
still of high-based variety. Wind gusts could push beyond forecast
parameters a few times in very deep mixing from 20Z-00Z but should
be exception. Cold front passage brings wind shift around 04Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...67
AVIATION...65
AREA FORECAST DISCUSSION
NWS TOPEKA KS
353 AM CDT Tue Apr 21 2015
.SHORT TERM...(Today and Tonight)
Issued at 300 AM CDT TUE APR 21 2015
Deep upper low over the Great Lakes was making slow eastward
progress early this morning with likely a few small scale waves
rotating around it through the Northern and Central Plains. Periodic
mid cloud was present over the local area via isentropic upglide
from rather brisk and backed mid level winds. At least minor amounts
of EPV along the moist layer allowing some showers to form aloft,
with weak returns on radar showing some very light precip reaching
to the lower troposphere. HRRR and RAP runs quite similar to some
4km WRF runs with light precip forming over central Kansas in the
next few hours, with latest IR imagery indicating recent cloud
development there. All nearby 0Z soundings measured 850mb dewpoint
depressions around 12C, making measurable amounts hard to imagine in
this activity. A somewhat more unstable airmass develops over the
southeast quarter of Kansas this afternoon with weak surface
convergence. Will maintain small storm chances with still minor
isentropic lift and weak wave potential in place. The stronger wind
fields aloft could lead to some storm organization along with CAPE
around 500 J/kg and dry adiabatic low level lapse rates to produce a
very small threat for severe wind and hail in the mid afternoon to
early evening. Areas outside of storms could also see a few rather
strong wind gusts with mixing depths reaching 7000-10000ft AGL
though some veering remains through the column. The still dry
airmass and gusty winds lead to elevated fire danger in western
locations this afternoon.
Cold front via a stronger wave rotating around the low arrives this
evening and makes quick south progress through the state tonight.
Moisture, though modest, will continue to pool ahead of this front
for some storm chances through much of the night in the southern
zones, with typical diurnal trends allowing severe concerns to
diminish. Models are allowing the boundary layer to decouple fairly
quickly behind the front, but am somewhat skeptical of this given
the baroclinic zone they advertise. If winds can fall quicker than
expected, fairly clear skies could present a frost concern, but even
if they do the window of cold and calm conditions for formation
should be rather limited. Will mention patchy frost in far north
where concern is highest.
.LONG TERM...(Wednesday through Monday)
Issued at 300 AM CDT TUE APR 21 2015
Eastern Kansas remains on the southwest side of an upper surface
high for Wednesday, keeping high temperatures around 60 for most
of the area. Have kept rain chances out of the southern areas with
better chances south. Dry conditions continue Wednesday night into
Thursday, with lows in the upper 30s to near 40 and highs climbing
toward the middle 60s Thursday.
Upper pattern starts to shift Thursday night as shortwave ridge
noses out of the southern plains into our area, ahead of an upper
trof lifting northeast out of the four corners region. Initial
sensible weather impacts should be warmer lows in the 40s near 50
Thursday night with some showers possible after midnight as low
level jet makes a return over the area. Latest EC appears to be
trending toward the GFS solution for this shortwave as it moves
into the plains, taking a faster track and developing the warm
front from the surface low out into eastern or southeast Kansas.
GFS keeps the boundary south of the area and would make for cloudy
cool and rainy conditions area wide for Friday and Saturday night,
and with EC solutions also trending this way, have gone with
forecast as such.
Southern branch of the upper jet takes the shortwave trof east of
the area rather quickly on Saturday, with rain ending sometime
during the morning hours. Cooler high pressure once again noses
into the area behind the departing low and holds temperatures in
the low 60s, followed by overnight lows in the 40s. Highs on
Sunday rise a bit more into the middle 60s, and have kept rain
chances relegated to north and west while surface high continues
over the east. Another front progged to move across the area
Sunday night with northwest flow aloft returning on Monday.
Current forecast is for highs near 70, but this will depend on how
strong the front and wave are as to how much cooler air it does,
or does not, bring southward.
&&
.AVIATION...(For the 06Z TAFs through 06Z Tuesday Night)
Issued at 1123 PM CDT MON APR 20 2015
VFR prevails through period while weak passing systems bring sct
to bkn mid level clouds. Westerly winds gust near 20 kts in the
afternoon while sct thunderstorms that develop should remain
south of the terminals.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...67
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS PADUCAH KY
924 PM CDT WED APR 22 2015
.UPDATE...
ISSUED AT 918 PM CDT WED APR 22 2015
NO CHANGE TO THE CURRENT FROST ADVISORY...ALTHOUGH...MIGHT SEE A
LITTLE COLDER TEMPERATURES OVER MCLEAN AND NORTHEAST MULHENBURG
COUNTIES IN WEST KENTUCKY. WILL NEED TO MONITOR OVERNIGHT.
THE NAM-WRF HIGH RESOLUTION GUIDANCE FAMILIES AND RAP GUIDANCE
APPEAR TO HAVE THE BEST HANDLE ON THE SENSIBLE WEATHER ELEMENTS
OVERNIGHT. THE VAST MAJORITY OF THE COLDER AND AND FROST POTENTIAL
SHOULD REMAIN ALONG AND NORTH OF THE CRAWLEY`S RIDGE/SHAWNEE HILLS
REGION.
MAIN ADJUSTMENT WAS TO SLOW THE DEGREE AND INTENSITY OF THE
RETURNING MID-LEVEL CLOUDS FROM ARKANSAS AND OKLAHOMA INTO
MISSOURI AND KENTUCKY OVERNIGHT. THIS SHOULD REDUCE ANY
SIGNIFICANT DISRUPTION IN RADIATIVE COOLING OVERNIGHT.
UPDATE ISSUED AT 632 PM CDT WED APR 22 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 00Z TAF ISSUANCE.
UPDATE ISSUED AT 438 PM CDT WED APR 22 2015
SORRY FOR THE LATE NOTICE.
TALKS WITH A STATE AGRONOMIST IN PARTS OF THE AREA EXPECTED TO
SEE PATCHY FROST AND TEMPERATURES IN THE 30S OVERNIGHT
NECESSITATED THE ISSUANCE OF A FROST ADVISORY FROM 2 AM TO 8 AM
CDT THURSDAY MORNING. MAIN CONCERN IS FOR PRIVATE AND COMMERCIAL
STRAWBERRY GROWERS...AS WELL AS PRIVATE AND COMMERCIAL PLANT
GROWERS WITH PLANTS VERY SENSITIVE TO FROST DEVELOPMENT.
FROST ADVISORY AREA OUTLINED IS ALONG AND NORTH OF A PIEDMONT
MISSOURI...VIENNA ILLINOIS...CALHOUN KENTUCKY LINE AT THIS TIME.
MAIN LIMITING FACTOR FOR COVERAGE IS THE AMOUNT OF EVAPORATION AT
THE GROUND SURFACE FROM THE INFLUX OF DRY AIR TODAY. HOWEVER...THERE
IS STILL ENOUGH ANTECEDENT MOISTURE FROM EARLIER RAIN
EVENTS...INCLUDING THE ONE LAST NIGHT TO ERR ON THE SIDE OF CAUTION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 116 PM CDT WED APR 22 2015
HIGH PRESSURE SHOULD RESULT IN QUIET WEATHER TONIGHT. MOS
CONTINUES TO SUGGEST MID TO UPPER 30S I-64 CORRIDOR OR JUST SOUTH.
PATCHY FROST WAS ALREADY IN PLACE. WILL MAINTAIN THIS THOUGH IT
LOOKS MARGINAL ESPECIALLY WITH FORECAST TEMP / DEW POINT SPREADS
WHAT THEY ARE. WILL MAINTAIN DRY WEATHER THURSDAY INTO THURSDAY
EVENING AS HIGH PRESSURE SLOWLY MOVES EAST. THE GFS AND NAM ARE IN
AGREEMENT THAT SOME LIGHT SHOWER/THUNDERSHOWER ACTIVITY COULD MAKE
IT INTO SEMO LATE THURSDAY NIGHT...WITH CHANCES INTO FRIDAY AS
WELL GRADUALLY SHIFTING EAST. CHANCES OF CONVECTION INCREASE
FRIDAY NIGHT AS THE MODELS CONTINUE TO ADVERTISE AN UPPER TROF AND
ASSOCIATED SURFACE LOW MOVING FROM THE PLAINS TOWARD THE UPPER
MIDWEST. USED A BLEND OF MOS GUIDANCE FOR TEMPS. MODEL PREFERENCE
WAS A GFS/NAM BLEND.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 116 PM CDT WED APR 22 2015
MEDIUM CONFIDENCE THROUGH THE WEEKEND WITH LOW CONFIDENCE WITH PATH
OF THE SYSTEM MID WEEK NEXT WEEK. LATEST MODELS RUNS INDICATE THE
SYSTEM NEXT WEEK WILL HIT US WHILE OTHERS SHOW A MORE SOUTHERLY PATH.
MAIN CONCERN WITH EXTENDED WILL BE WITH STRONG OR POSSIBLY SEVERE
STORMS SATURDAY AFTERNOON. THE ONE LIMITING FACTOR WILL BE AVAILABLE
MOISTURE WITH MOST MODELS NEAR ONE INCH OR LESS PW OR NEAR THE 75TH
PERCENTILE. OTHERWISE WINDS SHOW A GOOD SPEED SHEAR NOT SO MUCH ON
WITH DIRECTIONAL SHEAR I.E SRH <10M2/S2. HOWEVER WITH 850MB-500MB
LAPSE RATES 7+/KM AND MU CAPES BETWEEN 3K AND 4K ANY THING THAT DOES
GET GOING HAS THE POTENTIAL FOR SEVERE WIND AND WITH THE FREEZING
LEVEL NEAR 10K COULD NOT RULE OUT HAIL EITHER. CONSIDERING THE
SIGNIFICANT INSTABILITY IT WILL NOT TAKE AS MUCH SHEAR TO GET SOME
ROTATION.
OTHERWISE WEAK RIDGE WILL BUILD IN SUNDAY WITH THE NEXT SYSTEM ON
ITS HEELS. THE 00Z WED EU TAKES THIS ENERGY SOUTH OF THE FA THROUGH
THE LOWER TN VALLEY. THE 12Z EU TAKES BRINGS IT A LITTLE FARTHER
NORTH THROUGH OUR CWA TUE AND EXITS WED EARLY. THE CANADIAN IS MUCH
SLOWER WITH THIS SYSTEM. THE 06Z WED DGEX BRINGS THE CORE OF THE
UPPER LOW RIGHT THROUGH OUR CWA. SOME ENSEMBLES THE GEFS GEPS AND
EPS TAKE THE BRUNT OF THE SYSTEM SOUTH BUT STILL BRINGS PRECIP OVER
THE AREA. THUS WILL ALLOW EXTENDED INIT AND COLLABORATION CALCULATE
JUST WHAT POPS TO INCLUDE.
WILL START OUT ABOVE NORMAL TEMPS FOR THE WEEKEND AND COOL TO NEAR
NORMAL NEXT WEEK AS NEXT SYSTEM MOVES INTO THE REGION.
&&
.AVIATION...
ISSUED AT 632 PM CDT WED APR 22 2015
VFR FORECASTS. A MID-LEVEL IMPULSE MAY RESULT IN SOME MID-LEVEL
CEILINGS AT KCGI AND KPAH OVERNIGHT...OTHERWISE FEW CLOUDS ARE
EXPECTED THROUGH THE PERIOD. SURFACE HIGH PRESSURE WILL SETTLE
OVER THE AREA...SO WEST/NORTHWEST WINDS WILL BECOME LIGHT THIS
EVENING. MIXING ON THURSDAY MAY RESULT IN SOME GUSTS INTO THE
TEENS AT KEVV AND KOWB.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...FROST ADVISORY FROM 2 AM TO 8 AM CDT THURSDAY FOR ILZ075>078-
080>091.
MO...FROST ADVISORY FROM 2 AM TO 8 AM CDT THURSDAY FOR MOZ076-086-087-
100.
IN...FROST ADVISORY FROM 2 AM TO 8 AM CDT THURSDAY FOR INZ081-082-
085>088.
KY...FROST ADVISORY FROM 2 AM TO 8 AM CDT THURSDAY FOR KYZ014-015-018-
019.
&&
$$
UPDATE...SMITH
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
216 PM CDT TUE APR 21 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 215 PM CDT TUE APR 21 2015
NEAR TERM ON TRACK...AS CONVECTION CONTINUES TO TAKE SHAPE OVER
SOUTHERN INTO SOUTHEAST MISSOURI...LIGHTNING NOW OBSERVED WEST OF
OUR CWFA. WILL CONTINUE TO MONITOR FOR THE POSSIBILITY OF SOME
HAIL AND GUSTY WINDS GIVEN THE STEEP LAPSE RATES AND LOW FREEZING
LEVELS...DESPITE LACK OF LOW LEVEL MOISTURE. THE CHANCES WILL
CONTINUE THROUGH THE OVERNIGHT AS A BOUNDARY SETTLES SOUTH ACROSS
THE REGION. WILL DIMINISH POPS FROM NW TO SE WEDNESDAY MORNING...DRY
BY AFTERNOON. WILL KEEP IT DRY WEDNESDAY NIGHT THROUGH THURSDAY
WITH WEAK HIGH PRESSURE ANGLING IN FROM THE UPPER MIDWEST. CHANCES
OF SHOWERS MAY EXIST JUST SOUTH OF THE AREA NEAR OUR CWFA BORDER.
CAN ADJUST IF NEED BE. TEMPS A BLEND OF MOS AND EXISTING NUMBERS.
NAM HIGH RES AND HRRR A REASONABLE APPROACH FOR CONVECTIVE TRENDS
THROUGH 06Z.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 215 PM CDT TUE APR 21 2015
THE OPERATIONAL MODELS ARE TRYING TO FALL SOMEWHAT IN LINE WITH
PRIOR ENSEMBLE MEAN SOLUTIONS THROUGH SUNDAY. ALL IN ALL...
CONFIDENCE CONTINUES TO INCREASE FOR THE FIRST SYSTEM FRIDAY
THROUGH SATURDAY. UPPER TROF SHOULD EJECT NE INTO THE PLAINS BY
00Z SAT WITH MOISTURE QUICKLY SPREADING EAST BY FRIDAY AFTERNOON
AND EVENING. S/WV RIDGE AHEAD OF THE TROF NOT STRONG ENOUGH TO
WARD OFF ONCOMING SHRA/TSRA CHANCE. SO WE ARE ON THE AGGRESSIVE
SIDE OF THE ENVELOPE. LIKELY POPS STILL IN PLAY FOR FRIDAY NIGHT
WITH CHANCE TO LOW END LIKELY SATURDAY AS WELL...AS THE UPPER TROF
WEAKENS...AND THE REMNANT ENERGY TURNS ESE ACROSS THE AREA
SATURDAY...CONTINUING THE CHANCE OF CONVECTION. SURFACE BOUNDARY
SHOULD STAY JUST TO OUR SOUTH...SO ESSENTIALLY ELEVATED CONVECTION.
CHANCES TAIL OFF SATURDAY NIGHT WITH A DRY FORECAST IN PLACE FOR
SUNDAY. FOR MONDAY THROUGH TUESDAY...THE ENSEMBLE MEAN SOLUTIONS
WERE UTILIZED AND OPERATIONAL MODELS THROWN OUT. A HIGHLY COMPLEX
PATTERN IS FORECAST TO EVOLVE WITH SOME KIND OF A TROUGH EAST OF
THE PLAINS AND RIDGE WEST. HOWEVER THERE IS TOO MUCH VARIABILITY
IN THE DETAILS TO SIDE WITH ANY OPS SOLUTION AT THIS POINT. ITS
GOING TO CHANGE. WE FEE COMFORTABLE MAINTAINING LOW CHANCE POPS
FOR SHOWERS GIVEN THE UNSETTLED LOOK TO THE PATTERN. TEMPS WERE A
BLEND OF BASE MODEL OUTPUT AND EXISTING FORECAST NUMBERS.
&&
.AVIATION...
ISSUED AT 1225 PM CDT TUE APR 21 2015
FIRST ITEM OF CONCERN THIS FORECAST PERIOD IS THE GUSTY SOUTHWEST
WINDS. THEY WILL CONTINUE GUSTING UP TO AROUND 25 MPH AT TIMES FOR
THE REST OF THE AFTERNOON...WITH THE GUSTS SUBSIDING AFTER 00-02Z.
ALL INDICATIONS ARE THAT CONVECTION WILL DEVELOP AFTER 18Z AND
LAST THROUGH THE EVENING...WITH GREATEST PROBABILITIES OVER THE
KCGI/KPAH AREAS. ACTIVITY WILL BE RATHER SCATTERED...I.E. SHOULD
BE ABLE TO FLY AROUND...SO OPTED FOR JUST A VCTS. WILL UPGRADE TO
A TEMPO GROUP IF STORMS BECOME MORE ORGANIZED/WIDESPREAD. GUSTY
WINDS WILL BE POSSIBLE IN THE STRONGER STORMS. A FRONTAL BOUNDARY
WILL BE ADVANCING FROM THE NORTH LATER TONIGHT INTO EARLY TOMORROW
MORNING. THIS WILL BE FOCUS FOR MORE CONVECTION AND POSSIBLY LOWER
CIGS. THE FRONT WILL ALSO BRING A WIND SHIFT AROUND TO THE
WEST/NORTHWEST.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1047 PM EDT WED APR 22 2015
.SYNOPSIS...
LOW PRESSURE WILL APPROACH THE REGION FROM THE WEST OVERNIGHT. AN
OCCLUDED FRONT WILL LIFT ACROSS THURSDAY. THE WEATHER PATTERN WILL
REMAIN UNSETTLED THROUGH THE WEEKEND AS LOW PRESSURE ONLY SLOWLY
MOVES INTO THE MARITIMES.
&&
.NEAR TERM /THROUGH THURSDAY/...
1030 PM UPDATE: HRLY TEMPS WERE ADJUSTED ONE MORE TIME TO FIT THE
CURRENT CONDITIONS. TEMPS FELL BACK INTO THE UPPER 30S BACK ACROSS
THE WNW W/CLEARING EARLIER BUT SHOULD LEVEL OFF AND BEGIN TO RISE
OVERNIGHT. RADAR WAS PICKING UP ON SOME SHOWERS BACK ACROSS THE W
AND DOWN ACROSS THE COAST OUT AHEAD OF THE MAIN LOW. MAIN RAIN
SHIELD WAS BACK ACROSS NH AND SOUTHERN ME LIFTING NE. ADJUSTMENTS
WERE MADE TO THE LATEST TREND BRINGING BROKEN LINES OF SHOWERS
LIFTING N TONIGHT AND THEN THE PRECIP IS FORECAST TO FILL IN MORE
OVERNIGHT INTO THURSDAY. STILL EXPECTING TSTMS TO DEVELOP ACROSS
THE DOWNEAST AND THE COAST. DECIDED TO BRING TSTMS INTO THE
CENTRAL HIGHLANDS BASED ON THE LATEST 00Z NAM AND RAP SOUNDINGS
SHOWING SOME ELEVATED CONVECTION.
SFC LOW PRES VCNTY OF JAMES BAY WILL MOVE TO NEAR QUEBEC CITY THU
AFTERNOON. THE ACCOMPANYING UPPER LEVEL LOW IS ACROSS ONTARIO THIS
AFTERNOON AND WILL MOVE INTO NORTHERN NEW ENGLAND THU PM. AN
OCCLUSION WILL LIFT NORTH ACROSS THE CWA THU. MOST OF THE RAIN IS
FALLING WELL BACK TO THE WEST OF THE AREA THIS AFTERNOON ACROSS
NEW YORK STATE. RAIN WILL OVERSPREAD THE AREA FROM SOUTHWEST LATER
THIS EVENING AND OVERNIGHT. THE RAIN WILL TAPER OFF TO SCATTERED
SHOWERS AND DRIZZLE THU AFTERNOON ACROSS DOWNEAST MAINE WITH
PERIODS OF RAIN CONTINUING INTO THE AFTERNOON IN THE NORTH. THERE
IS AN AREA OF INSTABILITY ALOFT ASSOCIATED WITH A STRONG MID/UPPER
LEVEL JET WILL MOVE ACROSS PARTS OF DOWNEAST MAINE...MAINLY OVER
WASHINGTON COUNTY WELL AFTER MIDNIGHT AND THROUGH EARLY-MID
MORNING THAT COULD TOUCH OFF AN ISOLATED THUNDERSTORM.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
UNSETTLED WEATHER WILL CONTINUE THROUGH THE SHORT TERM PERIOD AS
UPPER LEVEL LOW PRESSURE REMAINS ACROSS THE REGION RIGHT THROUGH
THE PERIOD. THIS WILL RESULT IN PERIODS OF SHOWERS RIGHT THROUGH
THE PERIOD. THERE COULD EVEN BE SOME SNOW MIXED IN AT NIGHT MAINLY
ACROSS THE HIGHER TERRAIN OF THE NORTH AND WEST. LOWS THURSDAY
NIGHT AND FRIDAY NIGHT WILL GENERALLY BE IN THE LOW 30S NORTH AND
MID 30S CENTRAL AND DOWN EAST. HIGHS BOTH FRIDAY AND SATURDAY WILL
RANGE FROM THE UPPER 40S TO NEAR 50 NORTH AND CENTRAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
UPPER LEVEL LOW PRESSURE WILL CONTINUE TO AFFECT NORTHERN AND DOWN
EAST MAINE THROUGH TUESDAY WITH CONTINUED UNSETTLED CONDITIONS
EXPECTED. THIS WILL BRING MAINLY CLOUDY SKIES AND THE CHANCE FOR
SHOWERS TO THE REGION FROM TIME TO TIME. APPEARS AS IF THE UPPER
LOW WILL FINALLY MOVE OUT BY WEDNESDAY WITH IMPROVING CONDITIONS.
TEMPERATURES WILL BE CLOSE TO NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
NEAR TERM: CONDITIONS WILL LOWER TO MVFR AND EVENTUALLY IFR/LIFR
LATE TONIGHT AND THROUGH THU IN RAIN AND PATCHY FOG. SOME WIND
SHEAR IS POSSIBLE LATE TONIGHT AND EARLY THU...ESPECIALLY AT THE
DOWNEAST TERMINALS.
SHORT TERM: MVFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE
PERIOD MAINLY FOR CEILINGS.
&&
.MARINE...
NEAR TERM: HAVE TRANSITIONED THE SCA FOR HAZARDOUS SEAS TO A
GENERIC SCA FOR WIND AND SEAS ALONG THE COASTAL WATERS. HAVE
ISSUED A SCA FOR THE INTRACOASTAL WATERS STARTING LATE THIS
EVENING. THE WIND IS LIGHT THIS AFTERNOON...BUT WILL BE PICKING UP
TONIGHT AHEAD OF THE OCCLUDED FRONT. SEAS ARE RUNNING 6 TO 8 FT ON
THE OFFSHORE WATERS THIS AFTERNOON AND 3 TO 5 FT ON THE INTRA-
COASTAL WATERS.
SHORT TERM: THE SMALL CRAFT ADVISORY (SCA) FOR SEAS MAY NEED TO
BE EXTENDED THROUGH THURSDAY NIGHT...OTHERWISE WINDS/SEAS SHOULD
REMAIN BELOW SCA LEVELS FRIDAY THROUGH MONDAY.
&&
.HYDROLOGY...
MATM1 WILL REMAIN ABOVE MINOR FLOOD STAGE FOR THE
NEXT SEVERAL DAYS. RISES ARE LIKELY OVER THE NEXT COUPLE OF DAYS
ON AREA RIVERS AND STREAMS AS QPF OF 0.50" TO LOCALLY AN INCH IS
EXPECTED OVER THE NEXT 24 HOURS. AREA WATERWAYS ARE RUNNING AT
150-300 PERCENT OF NORMAL FLOW FOR THIS TIME OF YEAR. THERE IS
STILL ICE ON THE ST JOHN RIVER AROUND VAN BUREN...BUT THERE ARE NO
KNOWN ISSUES AT THIS TIME.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR ANZ052.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR ANZ050-051.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS GRAY ME
1219 AM EDT TUE APR 21 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 THIS MORNING/...
1215 AM...MINOR ESTF UPDATE TO REFLECT CURRENT RADAR TRENDS AND
TO INGEST THE 04Z MESONET INTO 1ST PERIOD GRIDS.
PREV DISC...
UPDATE...THE HIGHEST THREAT FOR STRONG WIND GUSTS IS
COMING TO AN END...SO WILL TAKE DOWN THE WIND ADVISORY. OTHERWISE
NO MAJOR CHANGES TO THE FORECAST. MESOSCALE MODELS STILL FAVOR THE
IDEA OF A COMPLEX OF TSTMS CROSSING THE FORECAST AREA DURING THE
MORNING. SO NO CHANGES THERE EITHER.
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 THIS MORNING THROUGH 6 AM WEDNESDAY/...
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 /04Z TUESDAY 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 UNTIL 3 AM EDT EARLY THIS MORNING FOR
MEZ025>028.
COASTAL FLOOD WARNING UNTIL 3 AM EDT EARLY THIS MORNING FOR
MEZ023-024.
NH...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR NHZ002>015.
COASTAL FLOOD WARNING UNTIL 3 AM EDT EARLY THIS MORNING FOR
NHZ014.
MARINE...GALE WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ150>154.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
738 PM EDT WED APR 22 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 344 PM EDT WED APR 22 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED UPR LO/
POCKET OF H5 TEMPS NEAR -30C CENTERED OVER ONTARIO TO THE SW OF
JAMES BAY DOWNSTREAM OF HI AMPLITUDE RDG OVER THE ROCKIES. DEEP
MOIST CYC NW FLOW ARND THE CLOSED LO CONTINUES TO IMPACT UPR MI...
DRAWING UNSEASONABLY CHILLY AIR /H85 TEMPS AS LO AS -12 TO -14C THAT
ARE SUFFICIENTLY COLD FOR LES/ INTO THE AREA. THE RESULT HAS BEEN
NMRS SN SHOWERS THAT HAVE BEEN EXACERBATED OVER LAND WITH DAYTIME
HEATING EVEN IN THE ABSENCE OF SGNFT LARGER SCALE FORCING/DEEP LYR
QVECTOR CNVGC.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/SN AMOUNTS
ESPECIALLY TNGT AS UPR LO DRIFTS SLOWLY TO THE E. TEMPS WL REMAIN
BLO NORMAL THRU THU.
TNGT...UPR LO IS FCST TO DRIFT SLOWLY TO THE E...ALLOWING FOR SLOWLY
RISING H5 HGT/WEAKENING LLVL CYC FLOW. ALTHOUGH SOME GENERAL LARGER
SCALE SUBSIDENCE IS FCST TO DOMINATE...H85 TEMPS REMAINING AS LO AS
ABOUT -13C IN THE PRESENCE OF SOME LINGERNING DEEP MSTR/NOCTURNAL
COOLING WL BE SUFFICIENT TO MAINTAIN LES IN THE FAVORED NW WIND SN
BELTS OVER THE ERN CWA. EXPECT UP TO A COUPLE INCHES OF SN ACCUM IN
THIS AREA. OVER THE W...WARMING H85 TEMPS TO ARND -10C/ LOWERING
SUBSIDENCE INVRN UNDER THE GREATER HGT RISES SHOULD TEND TO CAUSE
THE SN SHOWERS TO DIMINISH IN THAT AREA. HOWEVER...THE PERSISTENT
UPSLOPE NW FLOW AND LINGERING UPSLOPE FLOW WL ALLOW FOR AT LEAST
SOME SCT SN SHOWERS EVEN IN THAT AREA.
THU...PERSISTENT HGT RISES AND SUBSIDENCE/TENDENCY FOR THE LLVL FLOW
TO BECOME MORE ACYC AS WELL AS SOME LLVL DRYING IN THE PRESENCE OF
DAYTIME HEATING WL DIMINISH THE SN SHOWERS W-E. FCST SDNGS INDICATE
THERE WL BE SOME SUNSHINE IN THE AFTN AS WELL WITH HI PRES RDG FCST
TO BLD INTO THE WRN CWA LATER IN THE DAY. TEMPS SHOULD REBOUND INTO
THE 40S OVER THE INTERIOR W AND SCENTRAL AWAY FM LK MODERATION WITH
H85 TEMPS PROGGED TO REACH NEAR -6C ALONG THE WI BORDER BY 00Z FRI.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM EDT WED APR 22 2015
EVEN AS A SFC RIDGE MOVES IN FROM THE W THU NIGHT...ISOLATED SNOW
SHOWERS SHOULD LINGER INTO THE NIGHT IN NW WIND SNOWBELTS NEAR ERN
LAKE SUPERIOR. THIS AS 850MB TEMPS WILL BE AROUND -10C UNDER NW
WINDS. BY FRI MORNING...THE INCREASING INFLUENCE OF THE RIDGE AND
THE WARNING AIRMASS OVERHEAD WILL MAKE FOR A DRY DAY ACROSS THE U.P.
/RULING AT THE 12Z/22 GFS AS AN OUTLIER WITH THE LIGHT PRECIP OVER
THE FAR W/. CLEARING SKIES FROM W TO E THU NIGHT INTO FRI WILL LEAD
TO MIN TEMPS THU NIGHT IN THE TEENS OVER THE INTERIOR W AND IN THE
20S ELSEWHERE. HIGHS ON FRI WILL RANGE FROM THE MID 30S NEAR
CENTRAL/ERN LAKE SUPERIOR TO THE UPPER 40S ALONG THE WI BORDER.
THE WEEKEND LOOKS DRY...SUNNIER AND WARMER AS A SFC LOW SLIDES WELL
S OF THE CWA WITH SFC AND UPPER RIDGING REMAINING OVER THE CWA.
850MB TEMPS HOVERING AROUND 0C SAT AND SUN COMBINED WITH THE PARTLY
CLOUDS SKIES WILL MAKE FOR HIGHS IN THE 40S TO LOW 50S...COOLEST
NEAR LAKE SUPERIOR OVER AND E OF THE KEWEENAW DUE TO E-NE FLOW OFF
THE LAKE. THE RELATIVELY WEAK FLOW AND MORE LIMITED CLOUD COVER WILL
ALLOW MIN TEMPS SAT AND SUN NIGHTS TO BE IN THE MID 20S INLAND TO
LOW 30S ELSEWHERE.
MON ALSO LOOKS FREE OF PRECIP AS RIDGING WEAKENS BUT REMAINS
OVERHEAD. THE ECMWF SUGGEST THE UPPER LOW CURRENTLY IMPACTING THE
REGION MAY RETROGRADE BACK TOWARD THE AREA AFTER SITTING OVER NEW
ENGLAND...BUT THAT WOULD ONLY LEAD TO LIGHT PRECIP OVER THE E IF
THAT DID OCCUR...BUT WILL LEAVE PRECIP OUT OF THE FORECAST FOR NOW.
850MB TEMPS INCREASE A COUPLE OF DEGREES ON MON...BUT TEMPS SHOULD
BE SIMILAR TO SUN AS CLOUD COVER WILL BE INCREASED.
NOT REAL CONFIDENT FOR TUE AND WED AS MODELS SHOW UPPER LEVEL
IMPULSES MOVING THROUGH THE REGION...BUT THERE IS QUITE A BIT OF RUN
TO RUN AND MODEL TO MODEL DISCONTINUITY DURING THIS TIME AS A MORE
SIGNIFICANT PATTERN SHIFT MAY BE STARTING. PRECIP CHANCES ARE
GREATER THAN FRI-MON...BUT NOT HIGH BY ANY MEANS. TEMPS ON TUE LOOK
TO BE SIMILAR TO TUE...BUT MAY COOL DOWN A BIT ON WED. JUST USED A
CONSENSUS OF GUIDANCE FOR THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 736 PM EDT WED APR 22 2015
EXPECT PREDOMINANT MVFR CONDITIONS WITH COLD...MOIST NW FLOW OF AIR
AROUND DEEP LOW PRES IN SE CANADA THROUGH TONIGHT. UNDER THE HEAVIER
SHSN...CONDITIONS THROUGH THIS EVENING MAY BE REDUCED INTO THE IFR
RANGE. IMPROVEMENT TO VFR CONDITIONS IS EXPECTED THU WITH THE CLOSER
APPROACH OF SFC HIGH PRES AND DRIER AIR UNDER LARGE SCALE SUBSIDENCE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT WED APR 22 2015
A FEW NW WINDS GUSTING TO 30 TO NEAR 35KT GALES WILL REMAIN POSSIBLE
OVER N AND CENTRAL LAKE SUPERIOR THIS EVENING. LOW PRESSURE ACROSS
JAMES BAY WILL FILL LATE TONIGHT AND THURSDAY. THE TROUGH ACROSS
LAKE SUPERIOR THIS MORNING...EXTENDING FROM THE JAMES BAY LOW...WILL
SLOWLY BE REPLACED BY A RIDGE. THIS RIDGE WILL REMAIN IN PLACE FROM
FRIDAY THROUGH SUNDAY...EXTENDING FROM STRONG HIGH OVER FAR NORTHERN
CANADA AND GREENLAND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...JLB
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
352 PM EDT TUE APR 21 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 352 PM EDT TUE APR 21 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED UPR LO OVER
THE UPR LKS DOWNSTREAM OF HI AMPLITUDE UPR RDG OVER WRN NAMERICA.
COMBINATION OF DEEP CYC FLOW W TO NW FLOW AND INSTABILITY ENHANCED
BY DAYTIME HEATING UNDER ACCOMAPANYING THERMAL TROF /12Z H5 TEMP AT
GRB WAS -31C/ AND DEEP MSTR SHOWN ON THE 12Z RAOBS IS RESULTING IN
SCT-NMRS SN SHOWERS THAT ARE MIXED WITH RA IN THE WARMER LOCATIONS.
BUT COLDER CLD TOP TEMPS/MORE WIDESRPEAD SN SHOWERS ARE CONFINED
MAINLY TO NW ONTARIO/FAR NRN MN IN AREA WHERE MODELS INDICATE DEEP
QVECTOR CNVGC.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS AND POTENTIAL SN
ACCUMS ASSOCIATED WITH DEEP CYC...MOIST NW FLOW ARND SLOW MOVING
CLOSED LO TO THE NE OF UPR MI.
CLOSED LO CENTERED OVER ERN LK SUP THIS AFTN IS FCST TO DRIFT SLOWLY
TO THE NE AND TO JUST S OF JAMES BAY ON WED. ALTHOUGH ACCOMPANYING
DEEP LYR QVECTOR CNVGC THAT IS SUPPORTING COLDER CLD TOPS TO THE NW
IS FCST TO REMAIN TO THE N OF UPR MI...PERSISTENT MOIST...CYC NW
FLOW ARND THIS FEATURE WL MAINTAIN AT LEAST CHC POPS OVER THE CWA
THRU WED...WITH THE LOWER POPS GENERALLY OVER THE SCENTRAL AND THE
HIER POPS OVER THE HIER TERRAIN OF THE NW WITH UPSLOPE WIND
COMPONENT. BUT LOSS OF DAYTIME HEATING TNGT WL CAUSE THE
CHARACTER OF THE SHOWER PATTERN TO TRANSITIONS FM ONE THAT SUPPORTS
THE HIER POPS OVER THE INTERIOR THIS AFTN TO A MORE WINTRY LES
LOOK TNGT. IN FACT...THE NW FLOW IS PROGGED TO ADVECT H85 TEMPS AS
LO AS -13 TO -14C OVER THE KEWEENAW BY 12Z WED...TEMPS LO ENUF TO
SUPPORT LES AND INCRS SN/WATER RATIOS ONCE THE EFFECT OF DAYTIME
INSOLATION HAS FADED. OVER THE HIER TERRAIN OF THE W...THERE WL
LIKELY BE SEVERAL INCHES OF WET SN ACCUM TNGT INTO WED MRNG EVEN IN
THE ABSENCE OF SGNFT LARGER SCALE FORCING. OPTED TO ISSUE AN SPS
TO ALERT THE PUBLIC TO THE POTENTIAL OF SOME SLUSHY SN ACCUMS ON
ROADS LATER THIS EVNG INTO WED MRNG. DAYTIME HEATING ON WED WL
BRING ABOUT A RETURN TO A MORE LAND BASED INSTABILITY SHOWER
PATTERN. BUT SOMEWHAT HIER HGTS/SHARPENING MID LVL INVRN FARTHER FM
THE SLOWLY DEPARTING CLOSED LO THAT RESTRICTS DESTABILIZATION WL
TEND TO LIMIT COVERAGE/INTENSITY OF THE SHOWERS AS COMPARED TO TODAY.
ALTHOUGH H85 TEMPS ARE FCST TO MODERATE TO -10C TO -12C...MAX TEMPS
ON WED WL HOLD IN THE 30S EXPECT WHERE SOME DOWNSLOPE WARMING AIDS
DIURNAL TEMP RECOVERY INTO THE LO 40S OVER THE SCENTRAL. THERE COULD
BE SOME RECORD LO MAX TEMPS ON WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 PM EDT TUE APR 21 2015
THE UPPER LOW THAT IS CURRENTLY AFFECTING THE AREA WILL SHIFT EAST
INTO THE CANADIAN MARITIMES SHORTLY AFTER THE START OF THE LONG TERM
PERIOD. THIS WILL LEAVE THE AREA BETWEEN THAT UPPER LOW AND AN UPPER
RIDGE IN THE CENTRAL/SOUTHERN PLAINS. THUS...THE AREA WILL BE UNDER
NORTHWESTERLY FLOW ALOFT FOR MOST DAYS THROUGH THE UPCOMING WEEKEND.
WITH A SURFACE RIDGE STRETCHING SOUTH FROM A HIGH IN NORTHERN CANADA
MOVING INTO THE AREA BY FRIDAY AND FRIDAY NIGHT...EXPECT DRIER AIR
TO GRADUALLY MOVE INTO THE REGION AND DIMINISH THE PRECIPITATION
POTENTIAL AND LEAD TO A DRY WEEKEND (ALTHOUGH THERE ARE HINTS OF A
WEAK DISTURBANCE BRINGING AN ISOLATED SHOWER TO THE FAR WESTERN U.P.
LATE FRIDAY NIGHT INTO SATURDAY MORNING). WITH THE MAIN UPPER LOW
SHIFTING EAST...TEMPERATURES WILL SLOWLY WARM BUT STILL STAY BELOW
NORMAL FOR LATE APRIL (AIDED BY THE LIGHT NORTHERLY FLOW OFF LAKE
SUPERIOR).
HEADING INTO NEXT WEEK...THE UPPER LOW CURRENTLY OVER THE GULF OF
ALASKA WILL MOVE INTO THE PACIFIC NORTHWEST OVER THE NEXT 24-48HRS
AND THEN INTO THE CENTRAL CONUS ON MONDAY. AS THE WAVE CONTINUES
EAST...IT WILL INTERACT WITH THE UPPER LOW NEAR THE CANADIAN
MARITIMES AND RE-ESTABLISH THE UPPER TROUGH OVER THE EASTERN CONUS.
THIS WILL KEEP BELOW NORMAL TEMPERATURES IN PLACE INTO NEXT WEEK AND
POSSIBLY LEAD TO SOME SHOWERS AROUND THE GREAT LAKES REGION.
OVERALL...FAIRLY COOL AND QUIET END TO APRIL WITH NO HAZARDOUS
WEATHER EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 147 PM EDT TUE APR 21 2015
EXPECT SCT -SHSN...MIXED WITH RA AT THE WARMER SAW LOCATION...THIS
AFTN IN PERSISTENT CHILLY...MOIST AND GUSTY NW FLOW ARND LO PRES IN
ONTARIO ALONG WITH PREDOMINANT MVFR CONDITIONS. BEST CHC FOR SOME
HEAVIER SHSN/AT LEAST OCNL IFR CONDITIONS WL BE AT IWD WITH FVRBL
UPSLOPE FLOW. SAW HAS THE BEST CHC FOR VFR WX WITH A DOWNSLOPE WIND
COMPONENT. AS COLDER AIR ARRIVES TNGT...THE SHSN WL TEND TO INCREASE
IN COVERAGE AT CMX/IWD WITH USPLOPE NW WIND COMPONENT. PREDOMINANT
IFR TO OCNL MVFR VSBYS WL THE RULE AT THESE LOCATIONS INTO WED
MRNG...WHEN THE SHSN WL TEND TO BECOME MORE SCT AND ALLOW FOR
IMPROVING OVERALL CONDITIONS. DOWNSLOPE NATURE OF THE NW FLOW WL
LIMIT THE POTENTIAL FOR LOWER VSBYS AT SAW...BUT MVFR CIGS SHOULD
PREVAIL THERE WITH LINGERING LLVL MSTR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 305 PM EDT TUE APR 21 2015
NORTHWESTERLY WINDS UP TO 30 KNOTS WILL CONTINUE OVER LAKE SUPERIOR
THROUGH THURSDAY MORNING. THERE COULD BE A FEW PERIODS OF GALE
FORCE GUSTS TO 35KTS LATE TONIGHT INTO WEDNESDAY...BUT THEY
SHOULDN/T BE WIDESPREAD. HIGH PRESSURE WILL BEGIN TO BUILD INTO
WESTERN LAKE SUPERIOR THURSDAY AFTERNOON/NIGHT AND LEAD TO
GRADUALLY DIMINISHING WINDS INTO FRIDAY. LIGHT NORTHERLY WINDS UP
TO 15KTS ARE EXPECTED THIS WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
122 AM EDT TUE APR 21 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 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 120 AM EDT TUE APR 21 2015
APPROACH OF ANOTHER DISTURBANCE/LOW PRES TROF OVERNIGHT WILL RESULT
IN DETERIORATING CONDITIONS FROM MVFR TO IFR AT KIWD/KCMX AS -SHSN
INCREASE AGAIN. NOT OUT OF THE QUESTION THAT SOME BRIEF PERIODS OF
LIFR COULD OCCUR. DOWNSLOPE W TO SW WINDS AT KSAW WILL RESTRICT THE
IMPACT THERE...SO MVFR CIGS SHOULD PREVAIL. AFTER THE DISTURBANCE
EXITS TO THE E...EXPECT MVFR CONDITIONS TO RETURN TO KIWD/KCMX MID
TO LATE MORNING. -SHSN WILL CONTINUE AT ALL TERMINALS TODAY...AND
IT`S CERTAINLY POSSIBLE THAT BRIEF IFR VIS COULD OCCUR AT TIMES...
ESPECIALLY AT KIWD/KSAW AS DAYTIME HEATING/INSTABILITY AID -SHSN
INTENSITY. WINDS WILL GENERALLY REMAIN GUSTY...PARTICULARLY AT KCMX
WHERE GUSTS OF 25-30KT SHOULD BE COMMON FOR MUCH OF THE FCST PERIOD.
MVFR CONDITIONS WILL CONTINUE INTO THIS EVENING AT ALL TERMINALS.
&&
.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...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
841 PM MDT WED APR 22 2015
.UPDATE...
COMPLEX FLOW PATTERN OVER THE AREA WITH UPPER LOWS TO THE
NORTHWEST AND SOUTHWEST OF THE AREA...AND A BACKDOOR COLD FRONT
DRAPED OVER THE AREA. TRAPPED MID LEVEL MOISTURE WITHIN THIS
PATTERN IS RESULTING IN SCATTERED SHOWERS AND A FEW THUNDERSTORMS
IN THE VICINITY OF DISCRETE IMPULSES CROSSING THE WESTERN HALF OF
THE STATE. HI-RES MODELS HAVE DONE FAIRLY WELL WITH THE CHARACTER
OF THE CONVECTION SO FAR. THESE MODELS HINT AT SOME INCREASE IN
CONVECTION ALONG AND WEST OF A ROUNDUP TO NYE LINE BEFORE
MIDNIGHT...THEN ANOTHER PERIOD OF INCREASED ACTIVITY IN THE EARLY
MORNING HOURS...POSSIBLY SPREADING FURTHER EAST. THERE IS ALSO A
SUGGESTION OF SOME DEVELOPMENT FROM MUSSELSHELL/NORTHERN ROSEBUD
COUNTY SOUTHEAST INTO POWDER RIVER COUNTY OVERNIGHT IN THE DEEPER
EASTERLY LOW LEVEL FLOW BEHIND THE FRONT. GIVEN ALL THIS INCREASED
POPS TO HIGH CHANCE CATEGORY FOR WESTERN/NORTHWESTERN ZONES AND
PUSHED SLIGHT CHANCE FURTHER EAST AFTER MIDNIGHT TO ACCOUNT FOR
POTENTIAL WEAK DEVELOPMENT BEHIND THE FRONT. ALSO KEPT MENTION OF
THUNDER UNTIL MIDNIGHT. TEMPERATURES LOOK REASONABLE IN THE 35 TO
45 RANGE OVERNIGHT. CHAMBERS
&&
.SHORT TERM...VALID FOR THU AND FRI...
A DEEP UPPER TROUGH WILL WORK ACROSS SOUTHERN CANADA TONIGHT. THE
SOUTHERN EXTENT OF THE WAVE WILL SWING ACROSS THE FORECAST AREA. A
FLATTENING UPPER RIDGE WILL MOVE EAST AND DEFLECT MOST OF THE
ENERGY OVER NORTHERN MONTANA. HRRR WAS PUSHING SHOWERS WITH
EMBEDDED THUNDERSTORMS ACROSS THE WEST INTO CENTRAL ZONES. HAVE
PUSHED LOW POPS INTO BILLINGS THIS EVENING BASED ON THE HRRR
SOLUTION AND RADAR RETURNS DEVELOPING OVER THE WEST.
WILL KEEP SCATTERED POPS IN THE ZONES THURSDAY AND FRIDAY. THE
STRONGEST ENERGY WILL MOVE INTO THE WEST FRIDAY AFTERNOON AND
EVENING. LOW LEVEL EASTERLY WINDS WILL BE ABLE TO PREVENT THE
DEWPOINTS FROM DRYING OUT. MODEL PROGGED PWATS WERE AROUND 2
STANDARD DEVIATIONS ABOVE NORMAL...ESPECIALLY OVER THE EAST.
INSTABILITY WAS NOT EXPECTED TO BE TREMENDOUS...BUT ENOUGH TO
WARRANT ISOLATED THUNDER MENTION. WEAK MID LEVEL FLOW ON THURSDAY
WILL CAUSE PULSING...SHORT LIVED CELLS. CELLS WILL HAVE BETTER
MOVEMENT AND MORE ORGANIZATION ON FRIDAY. TEMPERATURES WILL BE IN
THE MID 60S TO RIGHT AROUND 70 BOTH THURSDAY AND FRIDAY. TWH
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
PATTERN CONTINUES TO LOOK UNSETTLED GOING INTO EARLY NEXT WEEK.
NEGATIVELY TILTED SHORTWAVE EMBEDDED IN SOUTHWEST FLOW ALOFT WILL
BRING A CHANCE FOR SHOWERS AND A FEW THUNDERSTORMS ON SATURDAY.
STRONGER UPPER LOW DEVELOPS OVER IDAHO AND SLIDES SOUTHEAST TOWARD
COLORADO SATURDAY NIGHT AND SUNDAY WITH 700MB LOW DEVELOPING OVER
NORTHERN WYOMING. THIS IS A GOOD PRECIPITATION PATTERN FOR THE
AREA LATE SATURDAY NIGHT THROUGH SUNDAY NIGHT. INCREASED
PRECIPITATION CHANCES TO LIKELY IN MOST LOCATIONS BY EARLY SUNDAY
MORNING...TAPERING OFF FROM NORTHWEST TO SOUTHEAST SUNDAY NIGHT
INTO MONDAY. MODELS INDICATING MANY AREAS COULD SEE HALF AN INCH
OF PRECIPITATION WITH THIS SYSTEM...WITH LOCALLY HEAVIER AMOUNTS
POSSIBLE. THIS IS A PRETTY WARM PACIFIC SYSTEM AND DYNAMIC
COOLING IS HAMPERED BY STRONGEST JET FORCING STAYING SOUTH OF THE
AREA...SO KEPT PRECIPITATION TYPE MAINLY RAIN BELOW 6000 FEET.
MODELS ALL GRABBING ONTO SOME SORT OF RIDGING TUESDAY INTO
THURSDAY NEXT WEEK FOR WARMER AND DRIER CONDITIONS. CHAMBERS
&&
.AVIATION...
MOSTLY CLEAR TO PARTLY CLOUDY SKIES WILL PREVAIL EAST OF A KMLS-
KSHR LINE. WEST OF THIS LINE EXPECT PARTLY TO MOSTLY CLOUDY SKIES
ALONG WITH AN ISOLATED SHOWER OR THUNDERSTORM CHANCE AND
ASSOCIATED MVFR CONDITION THROUGH 06Z. THE MOUNTAINS WILL BE
OBSCURED AT TIMES THROUGHOUT THE NIGHT. OTHERWISE...NO SIGNIFICANT
AVIATION HAZARDS ARE EXPECTED THIS EVENING AND THROUGH THE
OVERNIGHT HOURS. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 046/067 044/068 044/059 039/055 038/066 042/072 044/072
22/T 23/T 43/T 66/R 42/W 11/B 10/B
LVM 039/067 038/066 038/055 035/053 031/065 037/072 040/070
54/T 34/T 54/T 66/R 42/W 11/B 10/B
HDN 040/069 039/071 039/061 039/054 038/066 037/073 043/072
22/T 22/T 33/T 56/R 42/W 11/B 10/B
MLS 038/069 038/070 040/060 039/055 039/066 037/070 042/069
12/T 11/B 35/T 56/R 52/W 11/B 11/B
4BQ 037/071 038/070 041/061 040/055 039/065 039/069 041/068
12/T 22/T 25/T 57/R 63/W 11/B 11/U
BHK 032/065 034/064 036/058 040/053 039/062 038/066 041/064
02/T 11/B 25/T 56/R 63/W 11/B 11/B
SHR 039/067 039/067 039/056 037/050 036/063 037/069 039/066
02/T 22/T 22/T 47/R 52/W 11/B 10/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1236 PM CDT TUE APR 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT TUE APR 21 2015
AN ARCTIC COLD FRONT ACROSS NORTH DAKOTA WILL BACK INTO THE FCST
AREA THIS AFTN PRODUCING SOME CLOUDINESS. THE FRONT WILL CONTINUE
TO MOVE SOUTH AND WEST TONIGHT. BY 12Z WEDNESDAY A SMALL AREA OF
HIGH PRESSURE HAS SETTLED OVER NCNTL NEB WHICH SHOULD PRODUCE
LOWS IN THE 20S. BY THIS TIME...THE MODELS SUGGEST ANY CLOUD
COVER WOULD LIE ACROSS THE PANHANDLE AND SOUTHWEST NEB WHICH
WOULD HOLD UP LOWS IN THE LOWER 30S.
HIGHS TODAY RISE INTO THE 60S AHEAD OF THE FRONT WITH 50S NORTH
OF THE FRONT ALONG HIGHWAY 20.
THE MIDLEVEL CLOUD COVER ACROSS CNTL/SERN NEB EARLY THIS MORNING
IS ASSOCIATED WITH 700MB FRONTOGENESIS. THE RAP MOVES THESE
CLOUDS SOUTHEAST AND THEN DROPS A SECOND BATCH OF CLOUDS INTO NRN
NEB AS EARLY AS 15Z WHICH HANG AROUND MOST OF THE DAY AND THEN
MOVE SOUTH AND WEST TONIGHT. THE RADAR RETURNS ACROSS NORTH
DAKOTA MOVE EAST OF THE FCST AREA IN THE NAM MODEL WHILE THE HRRR
SHOWS TOO MUCH DRY AIR IN THE LOWER LEVELS FOR ANYTHING MORE THAN
SPRINKLES THIS AFTN AND TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 355 AM CDT TUE APR 21 2015
SURFACE HIGH PRESSURE QUICKLY FOLLOWS THE COLD FRONT AND WILL
SLIDE SOUTHEAST OF THE AREA EARLY IN THE DAY ON WEDNESDAY WITH
SOUTHERLY WINDS DEVELOPING. DESPITE SOUTHERLY WINDS...COOL AIR
ALOFT...850 TEMP FROM 3C EAST TO 8C WEST...AND EVEN WITH SUN AND
GOOD MIXING...HIGHS IN THE UPPER 50S AND LOWER 60S. MEANWHILE AN
UPPER LEVEL LOW LIFTS TOWARDS THE DESERT SW. MODELS ALSO SHOW A
WEAK SYSTEM AHEAD OF THE MAIN LOW...PUSHING ACROSS THE SOUTHERN
PLAINS.
A SECOND WAVE EJECTS FROM THE MAIN LOW AND ARRIVES TO THE
SOUTHERN/CENTRAL PLAINS WED NIGHT INTO THURSDAY. MARGINAL LIFT
INTO SW NEB MAY RESULT IN A FEW LIGHT SHOWERS INITIALLY. A BETTER
CHANCE ARRIVES LATER IN THE DAY ON THURSDAY AFTER WE GET SOME
HEATING. MODELS INCREASE CAPES TO A FEW 100 J/KG AND LIFTED INDEX
VALUES AROUND ZERO OR SLIGHTLY NEG. GENERALLY THING ACTIVITY WILL
BE SOME SHOWERS AND A FEW RUMBLES OF THUNDER HERE OR THERE.
BY FRIDAY THE MAIN LOW WILL BE CROSSING THE ROCKIES. MOISTURE
CONTINUES TO INCREASE AHEAD OF THE LOW AND FRIDAY LOOKS TO SEE A
WAVE OR TWO OF SHOWERS TO ROTATE THROUGH THE AREA. BETTER
MOISTURE LIFT ASSOCIATED CLOSER TO THE LOW...WHICH FAVORS HIGHER
POPS ACROSS SW NEB.
A SECOND WAVE...CLIPPER...QUICKLY FOLLOWS FOR THE WEEKEND. SHOULD
SEE A BRIEF BREAK IN THE ACTIVITY BEFORE THE SECOND WAVE
ARRIVES...ALTHOUGH TIMING THE BREAK IS DIFFICULT DUE TO MODEL
DIFFERENCES. FORECAST DOES RETAIN LOW POPS AND EXPECT THIS TO
CHANGE IN THE COMING DAYS AS THE LULL IN ACTIVITY BECOMES MORE
CLEAR. AT THIS TIME MODELS ARE IN FAVOR OF THE DRY PERIOD TO
OCCUR SOMETIME SATURDAY...EARLIEST IS THE GEM/GFS...WHILE LATER
IS FAVORED BY THE ECMWF.
THE NEXT WAVE SHOULD BE EAST OF THE AREA TO START THE WORK WEEK
DRY AND MILD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1235 PM CDT TUE APR 21 2015
A WEAK COLD FRONT WILL SLOWLY DROP THROUGH THE AREA THIS
AFTERNOON...SWITCHING WESTERLY WINDS TO THE NORTH. WITH GOOD
MIXING...NORTH TO NORTHWEST WINDS WILL BE 20-25 KTS AND GUSTY.
OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH WEDNESDAY MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...UNR-SR
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
632 AM CDT TUE APR 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT TUE APR 21 2015
AN ARCTIC COLD FRONT ACROSS NORTH DAKOTA WILL BACK INTO THE FCST
AREA THIS AFTN PRODUCING SOME CLOUDINESS. THE FRONT WILL CONTINUE
TO MOVE SOUTH AND WEST TONIGHT. BY 12Z WEDNESDAY A SMALL AREA OF
HIGH PRESSURE HAS SETTLED OVER NCNTL NEB WHICH SHOULD PRODUCE
LOWS IN THE 20S. BY THIS TIME...THE MODELS SUGGEST ANY CLOUD
COVER WOULD LIE ACROSS THE PANHANDLE AND SOUTHWEST NEB WHICH
WOULD HOLD UP LOWS IN THE LOWER 30S.
HIGHS TODAY RISE INTO THE 60S AHEAD OF THE FRONT WITH 50S NORTH
OF THE FRONT ALONG HIGHWAY 20.
THE MIDLEVEL CLOUD COVER ACROSS CNTL/SERN NEB EARLY THIS MORNING
IS ASSOCIATED WITH 700MB FRONTOGENESIS. THE RAP MOVES THESE
CLOUDS SOUTHEAST AND THEN DROPS A SECOND BATCH OF CLOUDS INTO NRN
NEB AS EARLY AS 15Z WHICH HANG AROUND MOST OF THE DAY AND THEN
MOVE SOUTH AND WEST TONIGHT. THE RADAR RETURNS ACROSS NORTH
DAKOTA MOVE EAST OF THE FCST AREA IN THE NAM MODEL WHILE THE HRRR
SHOWS TOO MUCH DRY AIR IN THE LOWER LEVELS FOR ANYTHING MORE THAN
SPRINKLES THIS AFTN AND TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 355 AM CDT TUE APR 21 2015
SURFACE HIGH PRESSURE QUICKLY FOLLOWS THE COLD FRONT AND WILL
SLIDE SOUTHEAST OF THE AREA EARLY IN THE DAY ON WEDNESDAY WITH
SOUTHERLY WINDS DEVELOPING. DESPITE SOUTHERLY WINDS...COOL AIR
ALOFT...850 TEMP FROM 3C EAST TO 8C WEST...AND EVEN WITH SUN AND
GOOD MIXING...HIGHS IN THE UPPER 50S AND LOWER 60S. MEANWHILE AN
UPPER LEVEL LOW LIFTS TOWARDS THE DESERT SW. MODELS ALSO SHOW A
WEAK SYSTEM AHEAD OF THE MAIN LOW...PUSHING ACROSS THE SOUTHERN
PLAINS.
A SECOND WAVE EJECTS FROM THE MAIN LOW AND ARRIVES TO THE
SOUTHERN/CENTRAL PLAINS WED NIGHT INTO THURSDAY. MARGINAL LIFT
INTO SW NEB MAY RESULT IN A FEW LIGHT SHOWERS INITIALLY. A BETTER
CHANCE ARRIVES LATER IN THE DAY ON THURSDAY AFTER WE GET SOME
HEATING. MODELS INCREASE CAPES TO A FEW 100 J/KG AND LIFTED INDEX
VALUES AROUND ZERO OR SLIGHTLY NEG. GENERALLY THING ACTIVITY WILL
BE SOME SHOWERS AND A FEW RUMBLES OF THUNDER HERE OR THERE.
BY FRIDAY THE MAIN LOW WILL BE CROSSING THE ROCKIES. MOISTURE
CONTINUES TO INCREASE AHEAD OF THE LOW AND FRIDAY LOOKS TO SEE A
WAVE OR TWO OF SHOWERS TO ROTATE THROUGH THE AREA. BETTER
MOISTURE LIFT ASSOCIATED CLOSER TO THE LOW...WHICH FAVORS HIGHER
POPS ACROSS SW NEB.
A SECOND WAVE...CLIPPER...QUICKLY FOLLOWS FOR THE WEEKEND. SHOULD
SEE A BRIEF BREAK IN THE ACTIVITY BEFORE THE SECOND WAVE
ARRIVES...ALTHOUGH TIMING THE BREAK IS DIFFICULT DUE TO MODEL
DIFFERENCES. FORECAST DOES RETAIN LOW POPS AND EXPECT THIS TO
CHANGE IN THE COMING DAYS AS THE LULL IN ACTIVITY BECOMES MORE
CLEAR. AT THIS TIME MODELS ARE IN FAVOR OF THE DRY PERIOD TO
OCCUR SOMETIME SATURDAY...EARLIEST IS THE GEM/GFS...WHILE LATER
IS FAVORED BY THE ECMWF.
THE NEXT WAVE SHOULD BE EAST OF THE AREA TO START THE WORK WEEK
DRY AND MILD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 630 AM CDT TUE APR 21 2015
THE MID LEVEL CLOUDS ACROSS SD WILL SPREAD SOUTH THROUGH THE
FORECAST AREA TODAY AND EXIT SOUTH AND WEST TONIGHT. VFR IS
EXPECTED ALL AREAS DURING THIS TIME.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
357 AM CDT TUE APR 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT TUE APR 21 2015
AN ARCTIC COLD FRONT ACROSS NORTH DAKOTA WILL BACK INTO THE FCST
AREA THIS AFTN PRODUCING SOME CLOUDINESS. THE FRONT WILL CONTINUE
TO MOVE SOUTH AND WEST TONIGHT. BY 12Z WEDNESDAY A SMALL AREA OF
HIGH PRESSURE HAS SETTLED OVER NCNTL NEB WHICH SHOULD PRODUCE
LOWS IN THE 20S. BY THIS TIME...THE MODELS SUGGEST ANY CLOUD
COVER WOULD LIE ACROSS THE PANHANDLE AND SOUTHWEST NEB WHICH
WOULD HOLD UP LOWS IN THE LOWER 30S.
HIGHS TODAY RISE INTO THE 60S AHEAD OF THE FRONT WITH 50S NORTH
OF THE FRONT ALONG HIGHWAY 20.
THE MIDLEVEL CLOUD COVER ACROSS CNTL/SERN NEB EARLY THIS MORNING
IS ASSOCIATED WITH 700MB FRONTOGENESIS. THE RAP MOVES THESE
CLOUDS SOUTHEAST AND THEN DROPS A SECOND BATCH OF CLOUDS INTO NRN
NEB AS EARLY AS 15Z WHICH HANG AROUND MOST OF THE DAY AND THEN
MOVE SOUTH AND WEST TONIGHT. THE RADAR RETURNS ACROSS NORTH
DAKOTA MOVE EAST OF THE FCST AREA IN THE NAM MODEL WHILE THE HRRR
SHOWS TOO MUCH DRY AIR IN THE LOWER LEVELS FOR ANYTHING MORE THAN
SPRINKLES THIS AFTN AND TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 355 AM CDT TUE APR 21 2015
SURFACE HIGH PRESSURE QUICKLY FOLLOWS THE COLD FRONT AND WILL
SLIDE SOUTHEAST OF THE AREA EARLY IN THE DAY ON WEDNESDAY WITH
SOUTHERLY WINDS DEVELOPING. DESPITE SOUTHERLY WINDS...COOL AIR
ALOFT...850 TEMP FROM 3C EAST TO 8C WEST...AND EVEN WITH SUN AND
GOOD MIXING...HIGHS IN THE UPPER 50S AND LOWER 60S. MEANWHILE AN
UPPER LEVEL LOW LIFTS TOWARDS THE DESERT SW. MODELS ALSO SHOW A
WEAK SYSTEM AHEAD OF THE MAIN LOW...PUSHING ACROSS THE SOUTHERN
PLAINS.
A SECOND WAVE EJECTS FROM THE MAIN LOW AND ARRIVES TO THE
SOUTHERN/CENTRAL PLAINS WED NIGHT INTO THURSDAY. MARGINAL LIFT
INTO SW NEB MAY RESULT IN A FEW LIGHT SHOWERS INITIALLY. A BETTER
CHANCE ARRIVES LATER IN THE DAY ON THURSDAY AFTER WE GET SOME
HEATING. MODELS INCREASE CAPES TO A FEW 100 J/KG AND LIFTED INDEX
VALUES AROUND ZERO OR SLIGHTLY NEG. GENERALLY THING ACTIVITY WILL
BE SOME SHOWERS AND A FEW RUMBLES OF THUNDER HERE OR THERE.
BY FRIDAY THE MAIN LOW WILL BE CROSSING THE ROCKIES. MOISTURE
CONTINUES TO INCREASE AHEAD OF THE LOW AND FRIDAY LOOKS TO SEE A
WAVE OR TWO OF SHOWERS TO ROTATE THROUGH THE AREA. BETTER
MOISTURE LIFT ASSOCIATED CLOSER TO THE LOW...WHICH FAVORS HIGHER
POPS ACROSS SW NEB.
A SECOND WAVE...CLIPPER...QUICKLY FOLLOWS FOR THE WEEKEND. SHOULD
SEE A BRIEF BREAK IN THE ACTIVITY BEFORE THE SECOND WAVE
ARRIVES...ALTHOUGH TIMING THE BREAK IS DIFFICULT DUE TO MODEL
DIFFERENCES. FORECAST DOES RETAIN LOW POPS AND EXPECT THIS TO
CHANGE IN THE COMING DAYS AS THE LULL IN ACTIVITY BECOMES MORE
CLEAR. AT THIS TIME MODELS ARE IN FAVOR OF THE DRY PERIOD TO
OCCUR SOMETIME SATURDAY...EARLIEST IS THE GEM/GFS...WHILE LATER
IS FAVORED BY THE ECMWF.
THE NEXT WAVE SHOULD BE EAST OF THE AREA TO START THE WORK WEEK
DRY AND MILD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1130 PM CDT MON APR 20 2015
FOR THE REMAINDER OF TONIGHT...SCATTERED TO BROKEN CIGS OF AROUND
10000 FT AGL ARE POSSIBLE THROUGH 12Z TUESDAY MORNING WITH
CLEARING THEREAFTER. SCATTERED CIGS AROUND 9000 TO 10000 FT AGL
ARE POSSIBLE DURING THE AFTERNOON HOURS WITH CLEARING EXPECTED
TUESDAY EVENING. WINDS WILL BE LIGHT AND VARIABLE AT UNDER 10 KTS
THROUGH MID MORNING...BECOMING WEST AND INCREASING TO 10 TO 20
KTS AROUND MIDDAY TUESDAY. SOME GUSTS TO 25 KTS ARE POSSIBLE
DURING THE LATE AFTERNOON HOURS. WINDS WILL SHIFT TO THE NORTH
AROUND 00Z WEDNESDAY AND WILL BE IN THE 10 TO 15 KT RANGE THROUGH
06Z WEDS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
708 PM EDT WED APR 22 2015
.SYNOPSIS...
A LARGE UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE FROM NORTH OF
THE GREAT LAKES EASTWARD ACROSS ONTARIO AND QUEBEC THIS WEEK. THIS
FEATURE WILL KEEP NORTHERN NEW YORK AND VERMONT TRAPPED IN AN
OVERCAST SHOWERY PERIOD. SOME SNOW SHOWERS ARE POSSIBLE ACROSS THE
HIGHER TERRAIN...WITH SOME ACCUMULATING SNOW FOR THE SUMMITS.
&&
.NEAR TERM /UNTIL 8 AM THURSDAY MORNING/...
AS OF 656 PM EDT WEDNESDAY...GOING FORECAST IN GOOD SHAPE. ONLY
MINOR ADJUSTMENTS TO HOURLY PARAMETERS FOR THIS EVENING SUCH AS
TEMPS/POPS TO REFLECT LATEST CONDITIONS AND TRENDS. RAIN RATHER
WIDESPREAD ACROSS VERMONT AT THIS TIME...WITH ONLY SCATTERED
SHOWERS OVER NORTHERN NEW YORK. EXPECT RAIN IN VERMONT TO DIMINISH
IN COVERAGE LATER ON THIS EVENING AS OCCLUDED FRONTAL BOUNDARY AND
ASSOCIATED SHORTWAVE MOVE ACROSS THE AREA. THREAT OF RAIN SHOWERS
WITH SNOW SHOWERS OVER THE MOUNTAINS WILL CONTINUE LATER TONIGHT
AS UPPER LOW SETTLES ACROSS THE REGION.
PREVIOUS DISCUSSION...
NORTH COUNTRY WILL REMAIN IN DEEP-LAYER SOUTHWESTERLY FLOW THIS
EVENING AS CLOSED UPPER LOW BEGINS TO SLOWLY DRIFT EASTWARD.
SHORTWAVE CURRENTLY LIFTING NORTHEASTWARD ACROSS OUR VERMONT
ZONES...THIS WILL ENHANCE UPWARD MOTION AND EXPAND COVERAGE OF
SHOWER ACTIVITY THIS EVENING. EXPECT WIDESPREAD RAIN ACROSS OUR
VERMONT ZONES AND HAVE CATEGORICAL POPS FOR THIS REASON. LINGERING
RAIN SHOWERS THIS EVENING WILL GRADUALLY MOVE NEWD OUT OF THE
REGION OVERNIGHT...ENDING BY MIDNIGHT. WHILE SKIES WILL REMAIN
MOSTLY CLOUDY OVERNIGHT...LOW- LEVEL CAA FROM THE WEST WILL ALLOW
TEMPS TO FALL INTO THE LOW-MID 30S.
&&
.SHORT TERM /8 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 345 PM EDT WEDNESDAY...SEASONABLY COOL AND MOIST
CONDITIONS...WITH POTENTIAL FOR UPSLOPE/OROGRAPHIC SNOWFALL
THURSDAY NIGHT INTO FRIDAY...INCLUDING LIGHT TO MODERATE
ACCUMULATIONS FOR THE HIGHER SUMMITS.
DURING THE DAYTIME HOURS ON THURSDAY UPPER LEVEL LOW WILL BE ITS
CLOSEST IN PROXIMITY TO OUR FORECAST AREA. CLOUDY SKIES...COOL
TEMPERATURES AND MOIST CONDITIONS WILL CONTINUE. COOLER THAN
NORMAL TEMPERATURES CAN BE EXPECTED. POTENTIAL FOR SHOWERS
INCREASES WITH NORTHWESTERLY FLOW DEVELOPING IN THE AFTERNOON AND
OVERNIGHT. PRETTY GOOD UPSLOPE SNOW SET UP FOR THURSDAY NIGHT AND
COLD ENOUGH ABOVE 1000 FEET FOR SNOW...RAIN SNOW MIX IN THE VALLEY
LOCATIONS. BELOW NORMAL MINIMUM TEMPERATURES ARE EXPECTED WITH
MOST OF THE AREA BOTTOMING OUT AROUND FREEZING. REGION REMAINS
STUCK UNDER INFLUENCE OF UPPER LEVEL LOW ALL THE WAY THROUGH
FRIDAY NIGHT...LOW WILL BE REACHING THE GULF OF MAINE BY FRIDAY
NIGHT. GENERALLY ISOLATED VALLEY SHOWERS AND MORE FREQUENT RAIN
AND SNOW SHOWERS ACROSS THE HIGHER ELEVATIONS ON FRIDAY AND FRIDAY
NIGHT. BELOW NORMAL TEMPERATURES CONTINUE THROUGH THIS PERIOD.
COULD SEE SOME DECENT SNOW ACCUMULATIONS IN THE HIGHER ELEVATIONS
FOR LATE MAY THIS WEEK...BEST CHANCE FOR ACCUMULATIONS BEING
THURSDAY NIGHT INTO FRIDAY MORNING WITH THE STRONGEST
NORTHWESTERLY FLOW DURING THAT TIME AND OROGRAPHIC UPSLOPE EFFECTS
HELPING US OUT. AROUND 6 INCHES OF SNOW ALONG THE RIDGE TOPS FROM
JAY PEAK TO MOUNT MANSFIELD...AND SIMILARLY ACROSS THE HIGHEST
PEAKS OF THE ADIRONDACKS. A COATING TO 1 ONE AMOUNTS DOWN TO ABOUT
1000 FEET WITH NO SIGNIFICANT ACCUMULATIONS BELOW THAT. DURING THE
DAYTIME HOURS ON FRIDAY THE SNOW LEVEL SHOULD LIFT TO 2000 FEET OR
HIGHER.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 326 PM EDT WEDNESDAY...THE BEGINNING OF THE WEEKEND WILL
CONTINUE THE THEME OF PERIODIC APRIL SHOWERS WITH MOSTLY CLOUDY
SKIES UNDER PERSISTENT NORTHWEST UPSLOPE FLOW WITH A CLOSED UPPER
LEVEL LOW TO THE NORTHEAST.
BOTH THE GFS AND ECMWF MODEL INDICATE THE UPPER LEVEL LOW WILL BE
CENTERED JUST OFF THE COAST OF MAINE SATURDAY WITH A SURFACE LOW
PRESSURE SYSTEM LOCATED WELL OFFSHORE SOUTHWEST OF NOVA SCOTIA.
THE PERSISTENT NORTHWEST FLOW WILL GENERATE SOME OFF AND ON
UPSLOPE RAIN/SNOW SHOWERS WITH THE SNOW SHOWERS ONLY REALLY BEING
POSSIBLE IN THE HIGHER SUMMITS DURING THE DAYTIMES WITH A MIX OF
RAIN AND SNOW IN THE VALLEYS POSSIBLE IN THE OVERNIGHT HOURS.
BEGINNING NEXT WEEK THE UPPER LEVEL LOW CONTINUES TO STAY IN A
SEMI PERMANENT LOCATION CENTERED OVER NEW ENGLAND AND THEN A
SURFACE LOW PRESSURE SYSTEM WILL SLIDE OFFSHORE JUST SOUTH OF
VIRGINIA AND PHASE WITH THE RETROGRADING LOW FROM THE CANADIAN
MARITIMES. HOWEVER THE STRENGTH AND INTENSITY OF THAT LOW IS
SIGNIFICANTLY BETWEEN THE GFS AND ECMWF. THE ECMWF REMAINS THE
SLOWER MOVING MODEL FROM THE REST OF THE MODEL SUITE BEING FAR
MORE PROGRESSIVE AND ENDS UP DEVELOPING A 962MB LOW OFFSHORE.
GIVEN THE NATURE OF THE SINGLE OUTLIER I STAYED AWAY FROM THAT
SOLUTION AND RELIED MORE ON A BLEND OF THE CANADIAN AND GFS.
REGARDING TEMPERATURES, DAYTIME MAX TEMPS WILL SEE A SLIGHT
WARMING TREND THROUGH THE WEEKEND INTO NEXT WEEK. EXPECT MAX TEMPS
WILL START IN THE UPPER 40S TO MID 50S ON SUNDAY WARMING TO MID
50S TO LOW 60S BY WEDNESDAY NEXT WEEK. OVERNIGHT LOWS WILL BE
PRETTY CONSISTENTLY IN THE UPPER 20S IN THE HIGHER TERRAIN ABOVE
2000 FEET TO THE MID TO UPPER 30S IN THE SAINT LAWRENCE AND
CHAMPLAIN VALLEYS.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...PERIODS OF MVFR CEILINGS AND VISIBILITIES
DEVELOPING AS RAIN SHOWERS MOVE INTO THE REGION, AND EVEN SOME WET
SNOW FLAKES MIXED IN AT SLK OVERNIGHT AS TEMPS DROP IN THE
BOUNDARY LAYER. SOME OF THE HIRES WINDOWS ARE SHOWING THAT THE
RAIN COULD BE HEAVY AT TIMES IN RUT/MPV HOWEVER GIVEN THE
UNCERTAINTY IN HOW HEAVY THE RAIN WILL FAIL I`VE CONTINUED TO
LEAVE IT OUT OF THE TAFS FOR NOW AND WILL MONITOR/UPDATE AS
NECESSARY.
SCATTERED TO BROKEN VFR CLOUDS AND SCATTERED RAIN SHOWERS WILL
PERSIST ACROSS THE REGION THROUGH TODAY. A WAVE OF LOW PRESSURE
WILL BRING A MORE ORGANIZED PERIOD OF LIGHT RAIN IN THE AFTERNOON
AND EVENING AS DEPICTED IN THE LATEST HRRR WHICH HAS A HANDLE ON
SHOWERS NOW ENTERING THE ST. LAWRENCE VALLEY. THE HRRR SEEMS A BIT
ON THE FASTER SIDE TO MOVE THE SHOWERS OUT SO I INITIALIZED THE
FORECAST WITH THE HRRR BUT THEN TRENDED MORE TOWARDS AN ENSEMBLE
OF THE LOCAL WRF`S FOR THE EVENING WITH REGARDS TO WX/VSBY. WINDS
SOUTH/SOUTHWEST LESS THAN 7 KNOTS BECOMING 10 KNOTS WITH GUSTS
15-20 KNOTS DURING THE DAY TODAY.
OUTLOOK 18Z THURSDAY THROUGH SUNDAY... 18Z THURS - 00Z SAT: VFR
WITH PERSISTENT MOSTLY CLOUDY CONDITIONS AND SOME POSSIBLE MVFR
WITH OFF AND ON LIGHT RAIN. COULD BE A SLIGHT MIX OF RAIN/SNOW
LATE THURS EVENING.
00Z SAT - SUNDAY: VFR WITH PERIODS OF MVFR AS RAIN SHOWERS MOVE
THROUGH THE AREA.
&&
.HYDROLOGY...
FLOOD WARNING CONTINUES FOR THE BARTON RIVER NEAR COVENTRY. MAY
SEE SOME RISES ON OTHER SMALLER RIVERS IN THE REGION WITH
WIDESPREAD RAINFALL ACROSS THE AREA. AT THIS POINT DOES NOT LOOK
LIKE WE WILL NEED ANY FURTHER WARNINGS AT THIS TIME.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...RJS/NEILES
SHORT TERM...NEILES
LONG TERM...DEAL
AVIATION...DEAL
HYDROLOGY...NEILES
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
945 PM EDT WED APR 22 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL CROSS THE AREA LATE TONIGHT. HIGH PRESSURE
RETURNS TO THE AREA THURSDAY NIGHT INTO SATURDAY. LOW PRESSURE
TRACKS OFF THE COAST SATURDAY NIGHT AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 940 PM WEDNESDAY...SOUTHWEST BREEZES HAVE CALMED A BIT
INLAND BUT CONTINUE AT THE COAST. TEMPERATURES AT MID-EVENING ARE
GENERALLY IN THE MID/UPPER 60S WITH DEWPOINTS IN THE MID 40S TO
LOW 50S. COLD FRONT MOVING INTO THE NC MOUNTAINS AND WILL MAKE
SLOW PROGRESS EAST OVERNIGHT. PER LATEST 3KM HRRR AND OTHER HIGH-
RES AND SHORT TERM MODELS...THINK CHANCES FOR ANY PRECIPITATION
OVERNIGHT WILL BE MINIMAL AND WILL REMOVE THE 20 PCT POP FROM THE
FORECAST. A COOL NIGHT WITH LOWS UPPER 40S INLAND AND LOW/MID 50S
COAST AS THE FRONT MOVES OFFSHORE BETWEEN 09Z AND 12Z THURSDAY.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
UNDER DRY NW FLOW ALOFT, COOL SFC HIGH PRESSURE BUILDS IN FROM
THE NW IN THE WAKE OF OVERNIGHT COLD FRONTAL PASSAGE. SHUD SEE
LOTS OF SUNSHINE BUT LOWERING THICKNESS SUPPORT HIGH TEMPS ONLY IN
THE UPPER 60S TO LOWER 70S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
AS OF 3 PM WED...HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE NW
THU NIGHT AND FRI RESULTING IN PLEASANT CONDITIONS ACROSS EASTERN
NC. GOOD RADIATIONAL COOLING CONDITIONS THU NIGHT ALLOWING TEMPS
TO DROP TO THE 40-50 DEGREE RANGE. COULD SEE A COUPLE UPPER 30S IN
THE NORMALLY COOLER LOCATIONS INLAND...BUT NOT EXPECTING COLD
ENOUGH TEMPS FOR FROST AT THIS TIME. LOW LEVEL THICKNESS VALUES
AND SUNNY SKIES SUPPORT HIGHS 60-70 DEG FRI...COOLEST ALONG THE
OUTER BANKS WITH LOW LEVEL NW FLOW.
HIGH PRESSURE WILL WEAKEN AND MOVE OFF THE COAST SAT IN RESPONSE
TO LOW PRESSURE APPROACHING FROM THE WEST...WHILE WEAKER LOW
DEVELOPS ALONG STALLED BOUNDARY TO THE SOUTH. WEAKER LOW WILL MOVE
ALONG THE NC COAST SAT NIGHT..WITH BOTH LOWS MERGING OFF THE
COAST SUNDAY. STILL LOOKS LIKE THE BEST PRECIP CHANCES WILL BE
LATE SAT INTO EARLY SUN MORNING. WILL CONTINUE HIGH CHANCE TO
LIKELY POPS. AN ISO TSTM WILL BE POSSIBLE ACROSS THE SOUTHERN
ZONES/COASTAL WATERS SAT NIGHT INTO SUN...BUT WITH LITTLE
INSTABILITY WILL CONTINUE TO LEAVE OUT MENTION AT THIS TIME. HELD
ONTO CHANCE POPS SUN WITH LOW OFF THE COAST. HIGHS THROUGH THE
WEEKEND INTO THE 60S.
STACKED LOW OVER THE NE MON WILL GRADUALLY MOVE SSE PUSHING THE
UPPER TROUGH OFF THE EAST COAST...ALLOWING TEMPS TO RISE A FEW
DEGREE FOR MON/TUE WITH HIGHS IN THE LOW 60S/LOW 70S.
A STRONG LOW PRESSURE SYSTEM IS EXPECTED TO IMPACT THE REGION MID
TO LATE NEXT WEEK...00Z ECMWF STILL FASTER AND STRONGER WITH THE
LOW THAN THE 12Z GFS. INCREASING PRECIP CHANCES TUE NIGHT INTO
WED. TSTM POTENTIAL...AND OTHER ADDITIONAL IMPACTS...WILL BE
DETERMINED BY EVENTUAL TRACK OF LOW.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
SHORT TERM /THROUGH 00Z FRIDAY/...
AS OF 640 PM WEDNESDAY...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH
THE TAF CYCLE. SOME SCATTERED TO BROKEN MID CLOUDS ALONG WITH A
PASSING SHOWER OR TWO WILL ACCOMPANY THE COLD FRONT ACROSS THE
REGION OVERNIGHT. CLOUD BASES SHOULD BE QUITE HIGH AND THERE
SHOULD BE MORE THAN ENOUGH MIXING IN THE LOW-LEVELS ALONG WITH
VERY LOW DEWPOINTS TO PREVENT ANY FOG. GENERALLY SUNNY WITH
WESTERLY WINDS AND LOW DEWPOINTS AGAIN ON THURSDAY WITH VFR FLYING
CONDITIONS EXPECTED.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 3 PM
WED...PRED VFR CONDITIONS WILL PREVAIL THROUGH EARLY SATURDAY.
SUB-VFR CHANCES INCREASING SAT AFTERNOON INTO SUNDAY NIGHT...AS AN
AREA OF LOW PRESSURE MOVES ALONG THE COAST. BEST RAIN CHANCES LATE
SAT INTO EARLY SUN.
&&
.MARINE...
SHORT TERM /THROUGH THURSDAY/...
AS OF 945 PM WEDNESDAY...SOUTHWEST WINDS CONTINUE QUITE GUSTY THIS
EVENING WITH GUSTS TO 26 KNOTS AT OREGON INLET AND 29 KNOTS AT
DIAMOND BUOY. WINDS OF 20 TO 25 KNOTS ALSO CONTINUE ON THE PAMLICO
SOUND. CURRENT ADVISORIES LOOK GOOD AT THIS TIME. WINDS BECOME
N/NW WINDS LATE TONIGHT AND DIMINISH AS HIGH PRESSURE SETTLES OVER
THE REGION THURSDAY. SEAS UP TO 5 TO 7 FEET SHOULD SUBSIDE BY LATE
THURSDAY MORNING.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 3 PM
WED...HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE NW THU NIGHT
AND FRI. GOOD CAA THU NIGHT WITH MODELS SHOWING NWLY SURGE
15-25KT. BRIEF PERIOD OF SCA CONDITIONS WILL BE POSSIBLE THU NIGHT
INTO EARLY FRI. WILL CAP SEAS AT 5FT FOR NOW. WINDS WILL GRADUALLY
BACK AND DIMINISH THROUGH THE DAY FRI. AN AREA OF LOW PRESSURE
WILL APPROACH THE WATERS SAT...MOVING OFF THE COAST SAT NIGHT INTO
SUN WITH WINDS INCREASING TO 10-20KT. LOW WILL STRENGTHEN OFF THE
COAST SUN WITH NLY WINDS 10-20KT AND SEAS 2-5FT. NORTHERLY WINDS
CONTINUE INTO MON BECOMING MORE NW TUE.
A STRONG LOW PRESSURE SYSTEM IS EXPECTED TO IMPACT THE WATERS MID
TO LATE NEXT WEEK...00Z ECMWF STILL FASTER AND STRONGER WITH THE
LOW THAN THE 12Z GFS. STRONG WINDS AND BUILDING SEAS EXPECTED...THOUGH
IMPACTS WILL BE DETERMINED BY EVENTUAL TRACK OF LOW.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY WILL DROP INTO THE 25-30% RANGE THURSDAY
AFTERNOON BUT WINDS WONT BE AS STRONG AS TODAY. THEREFORE AN
INCREASED FIRE DANGER IS NOT ANTICIPATED AGAIN ON THURSDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT THURSDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT THURSDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT THURSDAY FOR AMZ150-156-
158.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CTC
SHORT TERM...BTC
LONG TERM...CQD
AVIATION...RF/CTC/CQD
MARINE...BTC/CTC/CQD
FIRE WEATHER...BTC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
955 AM EDT TUE APR 21 2015
.SYNOPSIS...HIGH PRESSURE WILL BUILD OVER NC FROM THE SOUTHWEST
TODAY AND TONIGHT... THEN SHIFT EAST OFF THE COAST TUESDAY NIGHT
INTO WEDNESDAY. A DRY COLD FRONT WILL APPROACH FROM THE NORTH
WEDNESDAY NIGHT AND PUSH SOUTH OF THE REGION THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 955 AM TUESDAY...
THE LATEST SURFACE ANALYSIS SHOWED THE COLD FRONT OFFSHORE WITH A
WEAK SURFACE TROUGH TOWARD THE MOUNTAINS. DRY AIR WAS NOTED ON THE
LATEST WATER VAPOR IMAGES...AND ALSO SHOWN ON UPPER-AIR ANALYSES AND
THE KGSO 12Z SOUNDING. WINDS ALOFT WERE STRONGER THAN FORECAST BY
GUIDANCE...AND THIS SHOULD TRANSLATE INTO SOME SURFACE WIND GUSTS AT
LEAST AROUND 20KT BASED ON THE LATEST RAP SOUNDINGS...POSSIBLY
BRIEFLY TO 25KT IN A FEW SPOTS. OUTSIDE OF FEW-TO-SCATTERED CU
TOWARD THE TRIAD ON THE LATEST VISIBLE SATELLITE IMAGES...RAP
SOUNDINGS SUGGEST CONSIDERABLE SUNSHINE THROUGHOUT CENTRAL NORTH
CAROLINA. SURFACE DEW POINTS HAD FALLEN QUICKLY AND LEANED TOWARD
THE LOWER DEW POINT OF THE RAP MODEL THIS AFTERNOON AS A RESULT...
MAKING FOR SOME MINIMUM RELATIVE HUMIDITIES IN THE 20S PERCENT
PARTICULARLY OVER THE NORTHWEST PIEDMONT. RECENT RAIN AND WET GROUND
SHOULD KEEP FIRE WEATHER CONCERNS LOW. 1000-850MB THICKNESSES AND
GOOD MIXING PROVIDE FOR EXPECTED HIGHS AS CURRENTLY FORECAST...
LEANING TOWARD THE WARMER MET MOS GUIDANCE FOR HIGHS PRIMARILY 69 TO
74.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
AS OF 1240 AM TUESDAY...
CLEAR AND COOL CONDITIONS EXPECTED TONIGHT. LOWS IN THE MID 40S WITH
LIGHT WINDS.
WEDNESDAY... THE MAIN ISSUE WILL BE THE EXPECTED GUSTY RETURN FLOW
DEVELOPING LATE MORNING THROUGH THE AFTERNOON FROM THE SW. WINDS
SHOULD INCREASE TO 15-20 MPH WITH GUSTS TO 30 MPH OUT AHEAD OF THE
APPROACHING DRY COLD FRONT. HIGHS WILL WARM INTO THE MID TO UPPER
70S WITH PARTLY SUNNY SKIES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AS OF 1212 AM TUESDAY...
A MOISTURE STARVED COLD FRONT IS EXPECTED TO PUSH SOUTH THROUGH
CENTRAL NORTH CAROLINA WEDNESDAY NIGHT... THEN STALL WELL SOUTH OVER
SOUTH CAROLINA THURSDAY INTO FRIDAY. THE MAIN MOISTURE SOURCES ARE
FORECAST TO BE CUT OFF AS THIS FRONT MOVES THROUGH WEDNESDAY NIGHT.
WEAK HIGH PRESSURE WILL BUILD SOUTHEAST FROM THE OHIO VALLEY INTO
NORTH CAROLINA LATER THURSDAY INTO FRIDAY. SENSIBLE WEATHER
WEDNESDAY NIGHT WILL FEATURE ONLY A CHANCE OF A SPRINKLE OR TWO OR A
VERY LIGHT SHOWER WITH THE FRONT. LOWS GENERALLY FROM 50 NORTH INTO
THE UPPER 50S SOUTH. MOSTLY SUNNY SKIES THURSDAY WILL GIVE WAY TO
SOME INCREASE IN MID AND HIGH CLOUDS IN THE WEST AND SOUTH FRIDAY.
HIGHS BOTH DAYS SHOULD BE AROUND 70 INTO THE LOWER 70S SOUTH. LOWS
THURSDAY NIGHT GENERALLY IN THE 40S.
SATURDAY THROUGH MONDAY... THE BEST CHANCE OF RAIN IS EXPECTED TO BE
SATURDAY INTO SUNDAY AS THE ACTIVE SOUTHERN BRANCH JET SYSTEM TRACKS
ACROSS THE LOWER MISSISSIPPI VALLEY TOWARD THE SOUTHEASTERN STATES.
UNCERTAINTY WITHIN THE MODELS CONTINUE WITH THE TIMING/STRENGTH/
AND TRACK WITH THE SYSTEM. MODELS CONTINUE TO SHOW A DEEP TROUGH
OVER SE CANADA AND THE EASTERN STATES AS WELL WHICH WILL ESSENTIALLY
GUARANTEE BELOW NORMAL LATE APRIL TEMPERATURES THIS WEEKEND INTO
NEXT WEEK. THE BIG QUESTION WILL BE HOW MUCH RAIN WILL FALL OVER THE
WEEKEND WITH THE SOUTHERN BRANCH SYSTEM. WE WILL MAINTAIN CHANCE POP
WITH INCREASING CONFIDENCE FOR THE WEEKEND.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 650 AM TUESDAY...
VFR CONDITIONS ARE NOW EXPECTED THROUGH THURSDAY OR FRIDAY.
SUB-VFR CONDITIONS ARE EXPECTED TO DEVELOP WITH RAIN BY SATURDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BADGETT
NEAR TERM...DJF
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...BADGETT
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
644 AM EDT TUE APR 21 2015
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM OVER THE GREAT LAKES WILL BRING VERY
WINDY CONDITIONS TODAY...ALONG WITH A CHANCE OF SHOWERS AT TIMES
THROUGH WEDNESDAY MORNING. DRIER CONDITIONS ARE EXPECTED FROM
WEDNESDAY AFTERNOON THROUGH THE REST OF THE WEEK...WITH BREEZY
AFTERNOONS AND COOL TEMPERATURES. ANOTHER CHANCE OF RAIN WILL ARRIVE
ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SCATTERED TO BROKEN CLOUDS IN THE 6KFT-10KFT LAYER ARE CROSSING
THE ILN CWA FROM WEST TO EAST...DELINEATED VERY NICELY ON IR
SATELLITE. WITHIN THESE PATCHES OF CLOUDS ARE SOME
CONVECTIVE-LOOKING SHOWERS...AND ALTHOUGH NO LIGHTNING HAS BEEN
OBSERVED...PEA SIZE HAIL WAS OBSERVED WITH ONE OF THE SHOWERS
(THANKS TO THE FREEZING LEVELS OF AROUND 4KFT).
THE PRIMARY CONCERN TODAY REMAINS THE THREAT FOR STRONG
WINDS...AND AN ANALYSIS OF 00Z MODEL DATA SUPPORTED MAINTAINING
THE CURRENT ORIENTATION FOR THE WIND ADVISORY (WITH A SPECIAL
WEATHER STATEMENT FOR THE REST OF THE FORECAST AREA). STRONG
UNIDIRECTIONAL FLOW (AT ABOUT 250 DEGREES) EXTENDS THROUGH THE
ENTIRE DEPTH OF THE TROPOSPHERE...WITH VALUES STEADILY INCREASING
OFF THE SURFACE. USING A RECENT RAP RUN AT KDAY ON BUFKIT AS AN
EXAMPLE (AT 18Z)...WINDS INCREASE TO 40 KNOTS AT 825MB...THEN 50
KNOTS AT 700MB...AND 60 KNOTS AT 600MB. TODAY WILL BE AN EXERCISE
IN MIXING...AS THE EVENTUAL DEPTH OF THE MIXED LAYER WILL LIKELY
DETERMINE JUST HOW STRONG THE WINDS GET. GUSTS IN THIS FORECAST
WERE GENERALLY GLEANED FROM BUFKIT MOMENTUM TRANSFER VIA RAP/GFS
FORECASTS...WITH VALUES IN THE LOWER 40 KNOT RANGE IN THE NORTHERN
CWA...AND LOWER 30 KNOT RANGE IN THE SOUTHERN CWA.
ALTHOUGH CLEAR SKIES WILL BE IN PLACE AT THE BEGINNING OF THE
DAY...WEAK ELEVATED FORCING AND A SLIGHT INCREASE IN MOISTURE AT
THE TOP OF THE (RATHER HIGH) MIXED LAYER WILL RESULT IN SOME CLOUD
DEVELOPMENT...AND EVENTUALLY SHOWERS IN THE SOUTHEASTERN HALF OF
THE FORECAST AREA. THESE SHOWERS MAY BE VERY HIGH-BASED (PERHAPS
8000 FEET)...WITH SCATTERED COVERAGE AT MOST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
PRECIPITATION IS EXPECTED TO MOVE INTO THE REGION (OR PERHAPS
DEVELOP OVER THE FORECAST AREA) ON TUESDAY NIGHT INTO WEDNESDAY
MORNING. ALTHOUGH THERE ARE SOME MODEL DIFFERENCES WITH REGARDS TO
THE INTENSITY AND LAYOUT OF THE PRECIPITATION...THE OVERALL TIMING
APPEARS TO FAVOR THE 06Z-15Z TIME FRAME FOR THE ILN FORECAST
AREA...AHEAD OF A SHORTWAVE AND A SURFACE COLD FRONT. ALTHOUGH
THIS FRONT SHOWS UP NICELY ON MSLP PLOTS...THE WIND SHIFT AND
CHANGE IN AIR MASS ARE NOT ESPECIALLY NOTABLE. INSTABILITY (EVEN
ELEVATED) WILL BE HARD TO COME BY...SO THOUGH THUNDER IS NOT AN
IMPOSSIBILITY WITH THIS SETUP...THE CHANCE SEEMS VERY LOW.
ONCE THIS FRONT PASSES...VERY SIMILAR CONDITIONS ARE EXPECTED FOR
THE REST OF THE WEEK...WITH NORTHWEST FLOW AND COOL WEATHER. OHIO
IS LIKELY TO REMAIN IN BETWEEN AREAS OF ENHANCED MOISTURE FROM THE
NORTHERN AND SOUTHERN STREAMS...LEADING TO GENERALLY SUNNY
CONDITIONS UNTIL FRIDAY NIGHT.
TEMPERATURES ON THURSDAY AND FRIDAY MORNING MAY BE COOL ENOUGH FOR
FROST...BUT MOISTURE AND WIND FORECASTS ARE NOT AS FAVORABLE.
THUS...FROST WILL NOT BE INCLUDED IN THE GRIDS OR HWO.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
SOME DEEPER MOISTURE WILL BE PULLED UP TOWARD OUR AREA ON
SATURDAY AHEAD OF SHORT WAVE ENERGY MOVING OUT OF THE ROCKIES.
WHILE THE BEST FORCING/MOISTURE ASSOCIATED WITH THIS WILL REMAIN
TO OUR SOUTH...SOME PCPN COULD SNEAK UP INTO AT LEAST SOUTHERN
PORTIONS OF OUR FA EARLY IN THE WEEKEND. THIS MAY ALSO ALLOW FOR A
SLIGHT MODIFICATION IN TEMPERATURES WITH HIGHS PUSHING INTO THE
UPPER 50S TO LOWER 60S BY THE END OF THE LONG TERM PERIOD.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
LARGE SCALE UPPER LEVEL LOW CENTERED OVER THE WESTERN GREAT LAKES
THIS MORNING WILL MOVE SLOWLY EAST THROUGH THE TAF PERIOD. EMBEDDED
DISTURBANCES ROTATING AROUND THE LOW WILL AFFECT OUR REGION FROM
TIME TO TIME.
FOR TODAY...STRONG SURFACE LOW PRESSURE WILL REMAIN NORTH OF THE
GREAT LAKES. MEANWHILE...A COLD FRONT WILL APPROACH THE REGION
FROM THE WEST. THE INCREASING SURFACE PRESSURE GRADIENT COMBINED
WITH DEEP MIXING WILL RESULT IN WINDY CONDITIONS FROM MID MORNING
INTO EARLY EVENING. WINDS WILL VEER FROM A SOUTHWEST TO A
WEST/SOUTHWEST DIRECTION WITH WIND GUSTS IN THE 30 TO 40 KNOT
RANGE. MODELS CONTINUE TO INDICATE THAT SOME MOISTURE IN THE LOW
TO MID LEVEL WILL DEVELOP/ADVECT NORTHEAST INTO THE REGION BY THIS
AFTERNOON. THIS CLOUD LAYER COULD BECOME CONVECTIVE ENOUGH TO
PRODUCE A FEW SPRINKLES OR LIGHT SHOWERS...MAINLY ALONG AND SOUTH
OF THE OHIO RIVER.
FOR TONIGHT...ONE OF THOSE EMBEDDED DISTURBANCES MENTIONED WILL
DIG SOUTHEAST INTO OUR AREA. THIS FEATURE WILL TEAM UP WITH
FRONTAL CONVERGENCE FROM THE ADVANCING COLD FRONT TO BRING A
THREAT OF SHOWERS TO THE TAF SITES BETWEEN 06Z AND 12Z. THERE
COULD BE SOME POCKETS OF MVFR VISIBILITIES ASSOCIATED WITH THE
MORE ROBUST SHOWERS.
OUTLOOK...GUSTY WEST TO NORTHWEST WINDS UP TO 30 KNOTS EXPECTED
WEDNESDAY AFTERNOON INTO EARLY EVENING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR OHZ026-034-035-042>046-051>056-060>062.
KY...NONE.
IN...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR INZ050.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...JGL
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
415 AM EDT TUE APR 21 2015
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM OVER THE GREAT LAKES WILL BRING VERY
WINDY CONDITIONS TODAY...ALONG WITH A CHANCE OF SHOWERS AT TIMES
THROUGH WEDNESDAY MORNING. DRIER CONDITIONS ARE EXPECTED FROM
WEDNESDAY AFTERNOON THROUGH THE REST OF THE WEEK...WITH BREEZY
AFTERNOONS AND COOL TEMPERATURES. ANOTHER CHANCE OF RAIN WILL ARRIVE
ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SCATTERED TO BROKEN CLOUDS IN THE 6KFT-10KFT LAYER ARE CROSSING
THE ILN CWA FROM WEST TO EAST...DELINEATED VERY NICELY ON IR
SATELLITE. WITHIN THESE PATCHES OF CLOUDS ARE SOME
CONVECTIVE-LOOKING SHOWERS...AND ALTHOUGH NO LIGHTNING HAS BEEN
OBSERVED...PEA SIZE HAIL WAS OBSERVED WITH ONE OF THE SHOWERS
(THANKS TO THE FREEZING LEVELS OF AROUND 4KFT).
THE PRIMARY CONCERN TODAY REMAINS THE THREAT FOR STRONG
WINDS...AND AN ANALYSIS OF 00Z MODEL DATA SUPPORTED MAINTAINING
THE CURRENT ORIENTATION FOR THE WIND ADVISORY (WITH A SPECIAL
WEATHER STATEMENT FOR THE REST OF THE FORECAST AREA). STRONG
UNIDIRECTIONAL FLOW (AT ABOUT 250 DEGREES) EXTENDS THROUGH THE
ENTIRE DEPTH OF THE TROPOSPHERE...WITH VALUES STEADILY INCREASING
OFF THE SURFACE. USING A RECENT RAP RUN AT KDAY ON BUFKIT AS AN
EXAMPLE (AT 18Z)...WINDS INCREASE TO 40 KNOTS AT 825MB...THEN 50
KNOTS AT 700MB...AND 60 KNOTS AT 600MB. TODAY WILL BE AN EXERCISE
IN MIXING...AS THE EVENTUAL DEPTH OF THE MIXED LAYER WILL LIKELY
DETERMINE JUST HOW STRONG THE WINDS GET. GUSTS IN THIS FORECAST
WERE GENERALLY GLEANED FROM BUFKIT MOMENTUM TRANSFER VIA RAP/GFS
FORECASTS...WITH VALUES IN THE LOWER 40 KNOT RANGE IN THE NORTHERN
CWA...AND LOWER 30 KNOT RANGE IN THE SOUTHERN CWA.
ALTHOUGH CLEAR SKIES WILL BE IN PLACE AT THE BEGINNING OF THE
DAY...WEAK ELEVATED FORCING AND A SLIGHT INCREASE IN MOISTURE AT
THE TOP OF THE (RATHER HIGH) MIXED LAYER WILL RESULT IN SOME CLOUD
DEVELOPMENT...AND EVENTUALLY SHOWERS IN THE SOUTHEASTERN HALF OF
THE FORECAST AREA. THESE SHOWERS MAY BE VERY HIGH-BASED (PERHAPS
8000 FEET)...WITH SCATTERED COVERAGE AT MOST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
PRECIPITATION IS EXPECTED TO MOVE INTO THE REGION (OR PERHAPS
DEVELOP OVER THE FORECAST AREA) ON TUESDAY NIGHT INTO WEDNESDAY
MORNING. ALTHOUGH THERE ARE SOME MODEL DIFFERENCES WITH REGARDS TO
THE INTENSITY AND LAYOUT OF THE PRECIPITATION...THE OVERALL TIMING
APPEARS TO FAVOR THE 06Z-15Z TIME FRAME FOR THE ILN FORECAST
AREA...AHEAD OF A SHORTWAVE AND A SURFACE COLD FRONT. ALTHOUGH
THIS FRONT SHOWS UP NICELY ON MSLP PLOTS...THE WIND SHIFT AND
CHANGE IN AIR MASS ARE NOT ESPECIALLY NOTABLE. INSTABILITY (EVEN
ELEVATED) WILL BE HARD TO COME BY...SO THOUGH THUNDER IS NOT AN
IMPOSSIBILITY WITH THIS SETUP...THE CHANCE SEEMS VERY LOW.
ONCE THIS FRONT PASSES...VERY SIMILAR CONDITIONS ARE EXPECTED FOR
THE REST OF THE WEEK...WITH NORTHWEST FLOW AND COOL WEATHER. OHIO
IS LIKELY TO REMAIN IN BETWEEN AREAS OF ENHANCED MOISTURE FROM THE
NORTHERN AND SOUTHERN STREAMS...LEADING TO GENERALLY SUNNY
CONDITIONS UNTIL FRIDAY NIGHT.
TEMPERATURES ON THURSDAY AND FRIDAY MORNING MAY BE COOL ENOUGH FOR
FROST...BUT MOISTURE AND WIND FORECASTS ARE NOT AS FAVORABLE.
THUS...FROST WILL NOT BE INCLUDED IN THE GRIDS OR HWO.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
SOME DEEPER MOISTURE WILL BE PULLED UP TOWARD OUR AREA ON
SATURDAY AHEAD OF SHORT WAVE ENERGY MOVING OUT OF THE ROCKIES.
WHILE THE BEST FORCING/MOISTURE ASSOCIATED WITH THIS WILL REMAIN
TO OUR SOUTH...SOME PCPN COULD SNEAK UP INTO AT LEAST SOUTHERN
PORTIONS OF OUR FA EARLY IN THE WEEKEND. THIS MAY ALSO ALLOW FOR A
SLIGHT MODIFICATION IN TEMPERATURES WITH HIGHS PUSHING INTO THE
UPPER 50S TO LOWER 60S BY THE END OF THE LONG TERM PERIOD.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
LARGE SCALE UPPER LEVEL LOW CENTERED OVER THE WESTERN GREAT LAKES
THIS MORNING WILL MOVE SLOWLY EAST THROUGH THE TAF PERIOD. EMBEDDED
DISTURBANCES ROTATING AROUND THE LOW WILL AFFECT OUR REGION FROM
TIME TO TIME.
FOR EARLY THIS MORNING...THERE WILL BE A LULL IN SIGNIFICANT
WEATHER ACTIVITY. MID CLOUDS CURRENTLY OVER THE REGION WILL PUSH
OFF TO THE EAST...LEAVING MOSTLY CLEAR CONDITIONS BY 12Z.
FOR TODAY...STRONG SURFACE LOW PRESSURE WILL REMAIN NORTH OF THE
GREAT LAKES. MEANWHILE...A COLD FRONT WILL APPROACH THE REGION
FROM THE WEST. THE INCREASING SURFACE PRESSURE GRADIENT COMBINED
WITH DEEP MIXING WILL RESULT IN WINDY CONDITIONS FROM MID MORNING
INTO EARLY EVENING. WINDS WILL VEER FROM A SOUTHWEST TO A
WEST/SOUTHWEST DIRECTION WITH WIND GUSTS IN THE 30 TO 40 KNOT
RANGE. MODELS CONTINUE TO INDICATE THAT SOME MOISTURE IN THE LOW
TO MID LEVEL WILL DEVELOP/ADVECT NORTHEAST INTO THE REGION BY THIS
AFTERNOON. THIS CLOUD LAYER COULD BECOME CONVECTIVE ENOUGH TO
PRODUCE A FEW SPRINKLES OR LIGHT SHOWERS...MAINLY ALONG AND SOUTH
OF THE OHIO RIVER.
FOR TONIGHT...ONE OF THOSE EMBEDDED DISTURBANCES WILL DIG
SOUTHEAST INTO OUR AREA. THIS FEATURE WILL TEAM UP WITH FRONTAL
CONVERGENCE FROM THE ADVANCING COLD FRONT TO BRING A THREAT OF
SHOWERS TO THE TAF SITES BETWEEN 06Z AND 12Z. THERE COULD BE SOME
POCKETS OF MVFR VISIBILITIES ASSOCIATED WITH THE MORE ROBUST
SHOWERS.
OUTLOOK...GUSTY WEST TO NORTHWEST WINDS UP TO 30 KNOTS EXPECTED
WEDNESDAY AFTERNOON INTO EARLY EVENING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR OHZ026-034-035-042>046-051>056-060>062.
KY...NONE.
IN...WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR INZ050.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...JGL
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS NORMAN OK
645 AM CDT TUE APR 21 2015
.DISCUSSION...
AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW.
&&
.AVIATION...
THINK VFR CONDITIONS WILL MAINLY PREVAIL.
ISO-SCT -SHRA WILL BE EAST OF KPNC-KOKC-KDUC BY 15Z.
ISO-SCT TSRA WILL LIKELY DEVELOP OVER WESTERN OKLAHOMA AFTER
06Z...THUS ADDED VCTS AT TAF SITES IN THESE AREAS. BRIEF VARIABLE
GUSTY WINDS...GS...AND MVFR OR LOWER CONDITIONS MAY BE POSSIBLE
WITH TSRA.
FAIRLY LIGHT SURFACE WINDS WILL SHIFT TO THE NORTH TO NORTHEAST
AT MANY SITES AFTER 06Z.
MVFR/IFR CONDITIONS MAY FORM SOUTH OF KWWR-KOUN AFTER 06Z. DID NOT
MENTION THINKING THESE LOWER CONDITIONS WILL NOT FORM IN THESE
LOCATIONS BEFORE 12Z WEDNESDAY.
MBS
&&
.PREV DISCUSSION... /ISSUED 358 AM CDT TUE APR 21 2015/
DISCUSSION...
THE FORECAST CHALLENGE OF THE DAY IS SEVERE WEATHER POTENTIAL
THROUGH FRIDAY.
THIS MORNING...ISOLATED TO SCATTERED SHOWERS FROM WEAK MID LEVEL
MOISTURE CONVERGENCE/ISENTROPIC LIFT WILL CONTINUE MAINLY ACROSS
SOUTHERN OKLAHOMA. CANNOT RULE OUT A RUMBLE OF THUNDER...BUT NO
SEVERE WEATHER WILL OCCUR. ANY RAINFALL WILL BE LIGHT AND UNDER
0.10 INCH.
THIS AFTERNOON...SKIES WILL CLEAR AND ALLOW FOR GOOD DAYTIME
HEATING. THINK CAPPING WILL BE TOO STRONG FOR STORM
DEVELOPMENT...EXCEPT PERHAPS NEAR A WEAK SURFACE BOUNDARY OVER
SOUTHERN KANSAS ACCORDING TO THE LATEST HRRR RUN. KEPT 20 PERCENT
CHANCE FOR STORMS NEAR THE KANSAS AND OKLAHOMA STATE LINE EAST OF
ALVA AFTER 4 PM. IF THESE STORMS FORM...THEY COULD BE SEVERE WITH
SOME LARGE HAIL UP TO GOLF BALLS AND DAMAGING WINDS UP TO 60 MPH
AS STRONG 0-6 KM SHEAR AND MUCAPE AROUND 1000 J/KG SUPPORT SOME
SEVERE POTENTIAL.
TONIGHT...WILL MONITOR FOR ADDITIONAL STORM FORMATION...MAINLY
AFTER MIDNIGHT ACROSS WESTERN OKLAHOMA ON THE NOSE OF THE LOW
LEVEL JET. LATEST MODELS HAVE BEEN TRENDING SLOWER WITH STORM
DEVELOPMENT. WITH INCREASING ELEVATED INSTABILITY AND STRONG 0-6
KM SHEAR...STORMS WILL BEGIN WITH LARGE HAIL UP TO GOLF BALLS AS
THE MAIN HAZARD...BUT MAY TRANSITION TO SOME WIND AND HAIL AS
STORMS MAY FORM INTO A CLUSTER OR LINE THEN MOVE EAST OR SOUTHEAST
TOWARDS DAYBREAK...MAINLY AFFECTING WESTERN OKLAHOMA. A FEW
ADDITIONAL SEVERE STORMS MAY BE NEAR A DEVELOPING COLD FRONT IN
NORTHERN OKLAHOMA. WIDESPREAD SEVERE SEEMS UNLIKELY TONIGHT.
WEDNESDAY...AN ACTIVE DAY OF SEVERE WEATHER MAY OCCUR...
ESPECIALLY ACROSS THE SOUTHERN HALF OF OKLAHOMA AND NORTH TEXAS. A
COMPLEX OF STORMS MAY OCCUR DURING THE MORNING HOURS AND MOVE EAST
OR SOUTHEAST BRINGING SOME WIND AND HAIL REPORTS AS WELL AS
LOCALLY HEAVY RAINFALL. REDEVELOPMENT MAY OCCUR DURING THE
AFTERNOON AND EVENING NEAR THE OUTFLOW BOUNDARY WHICH MAY BE NEAR
THE RED RIVER. THERE IS SOME POTENTIAL FOR SIGNFICANT SEVERE
INCLUDING GIANT HAIL GREATER THAN GOLF BALLS...DAMAGING WINDS OVER
70 MPH...AND PERHAPS TORNADOES IF LOW LEVEL SHEAR IS STRONG
ENOUGH...BUT CONFIDENCE OF THIS OCCURRING REMAINS LOW AS NOT SURE
HOW THE CONVECTION DURING THE MORNING AFFECTS THE ENVIRONMENT
DURING THE AFTERNOON AND EVENING HOURS. IT APPEARS NORTHERN
OKLAHOMA MAY NOT RECEIVE MANY STORMS OR SEVERE WEATHER WHERE THE
AIR WILL BE COOLER AND MORE STABLE.
WEDNESDAY NIGHT INTO THURSDAY...A FEW SEVERE STORMS MAY LINGER
OVER FAR SOUTHERN OKLAHOMA AND NORTH TEXAS WITH LARGE HAIL...
DAMAGING WINDS...AND HEAVY RAINFALL. HOWEVER...MOST STORMS MAY BE
SOUTH OF THE RED RIVER...LEAVING BEHIND COOL AND STABLE CONDITIONS
ACROSS OKLAHOMA. CONFIDENCE OF SEVERE STORMS DURING THIS TIME
FRAME REMAINS LOW AS NOT SURE HOW WEDNESDAY/S CONVECTION CHANGES
THE AIRMASS ACROSS THE REGION. WENT BELOW MODEL GUIDANCE
TEMPERATURES.
FRIDAY...ANOTHER ROUND OF SEVERE THUNDERSTORMS...POSSIBLY WITH
SIGNIFICANT SEVERE...MAY RETURN TO THE AREA. VERY STRONG
SHEAR/WINDS WOULD SUPPORT FAST MOVING SUPERCELLS. HOWEVER...
MOISTURE AND INSTABILITY REMAIN QUESTIONABLE...ESPECIALLY AS
CONVECTION OVER TEXAS MAY LIMIT THE NORTHWARD PROGRESS OF RICHEST
MOISTURE AND HIGHEST INSTABILITY. REGARDLESS...WILL CLOSELY
MONITOR. ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS ALONG WITH
WINDY AND HOT WEATHER MAY FORM BEHIND A DRYLINE.
SATURDAY THROUGH MONDAY...A QUIETER WEATHER PATTERN IS FORECAST
WITH NEAR AVERAGE TEMPERATURES.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 77 54 69 54 / 20 20 50 40
HOBART OK 77 54 73 54 / 10 40 70 40
WICHITA FALLS TX 78 57 76 57 / 10 20 40 40
GAGE OK 79 49 66 46 / 10 40 40 30
PONCA CITY OK 78 49 64 47 / 20 30 30 30
DURANT OK 76 57 75 60 / 30 10 60 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17/17
AREA FORECAST DISCUSSION
NWS NORMAN OK
358 AM CDT TUE APR 21 2015
.DISCUSSION...
THE FORECAST CHALLENGE OF THE DAY IS SEVERE WEATHER POTENTIAL
THROUGH FRIDAY.
THIS MORNING...ISOLATED TO SCATTERED SHOWERS FROM WEAK MID LEVEL
MOISTURE CONVERGENCE/ISENTROPIC LIFT WILL CONTINUE MAINLY ACROSS
SOUTHERN OKLAHOMA. CANNOT RULE OUT A RUMBLE OF THUNDER...BUT NO
SEVERE WEATHER WILL OCCUR. ANY RAINFALL WILL BE LIGHT AND UNDER
0.10 INCH.
THIS AFTERNOON...SKIES WILL CLEAR AND ALLOW FOR GOOD DAYTIME
HEATING. THINK CAPPING WILL BE TOO STRONG FOR STORM
DEVELOPMENT...EXCEPT PERHAPS NEAR A WEAK SURFACE BOUNDARY OVER
SOUTHERN KANSAS ACCORDING TO THE LATEST HRRR RUN. KEPT 20 PERCENT
CHANCE FOR STORMS NEAR THE KANSAS AND OKLAHOMA STATE LINE EAST OF
ALVA AFTER 4 PM. IF THESE STORMS FORM...THEY COULD BE SEVERE WITH
SOME LARGE HAIL UP TO GOLF BALLS AND DAMAGING WINDS UP TO 60 MPH
AS STRONG 0-6 KM SHEAR AND MUCAPE AROUND 1000 J/KG SUPPORT SOME
SEVERE POTENTIAL.
TONIGHT...WILL MONITOR FOR ADDITIONAL STORM FORMATION...MAINLY
AFTER MIDNIGHT ACROSS WESTERN OKLAHOMA ON THE NOSE OF THE LOW
LEVEL JET. LATEST MODELS HAVE BEEN TRENDING SLOWER WITH STORM
DEVELOPMENT. WITH INCREASING ELEVATED INSTABILITY AND STRONG 0-6
KM SHEAR...STORMS WILL BEGIN WITH LARGE HAIL UP TO GOLF BALLS AS
THE MAIN HAZARD...BUT MAY TRANSITION TO SOME WIND AND HAIL AS
STORMS MAY FORM INTO A CLUSTER OR LINE THEN MOVE EAST OR SOUTHEAST
TOWARDS DAYBREAK...MAINLY AFFECTING WESTERN OKLAHOMA. A FEW
ADDITIONAL SEVERE STORMS MAY BE NEAR A DEVELOPING COLD FRONT IN
NORTHERN OKLAHOMA. WIDESPREAD SEVERE SEEMS UNLIKELY TONIGHT.
WEDNESDAY...AN ACTIVE DAY OF SEVERE WEATHER MAY OCCUR...
ESPECIALLY ACROSS THE SOUTHERN HALF OF OKLAHOMA AND NORTH TEXAS. A
COMPLEX OF STORMS MAY OCCUR DURING THE MORNING HOURS AND MOVE EAST
OR SOUTHEAST BRINGING SOME WIND AND HAIL REPORTS AS WELL AS
LOCALLY HEAVY RAINFALL. REDEVELOPMENT MAY OCCUR DURING THE
AFTERNOON AND EVENING NEAR THE OUTFLOW BOUNDARY WHICH MAY BE NEAR
THE RED RIVER. THERE IS SOME POTENTIAL FOR SIGNFICANT SEVERE
INCLUDING GIANT HAIL GREATER THAN GOLF BALLS...DAMAGING WINDS OVER
70 MPH...AND PERHAPS TORNADOES IF LOW LEVEL SHEAR IS STRONG
ENOUGH...BUT CONFIDENCE OF THIS OCCURRING REMAINS LOW AS NOT SURE
HOW THE CONVECTION DURING THE MORNING AFFECTS THE ENVIRONMENT
DURING THE AFTERNOON AND EVENING HOURS. IT APPEARS NORTHERN
OKLAHOMA MAY NOT RECEIVE MANY STORMS OR SEVERE WEATHER WHERE THE
AIR WILL BE COOLER AND MORE STABLE.
WEDNESDAY NIGHT INTO THURSDAY...A FEW SEVERE STORMS MAY LINGER
OVER FAR SOUTHERN OKLAHOMA AND NORTH TEXAS WITH LARGE HAIL...
DAMAGING WINDS...AND HEAVY RAINFALL. HOWEVER...MOST STORMS MAY BE
SOUTH OF THE RED RIVER...LEAVING BEHIND COOL AND STABLE CONDITIONS
ACROSS OKLAHOMA. CONFIDENCE OF SEVERE STORMS DURING THIS TIME
FRAME REMAINS LOW AS NOT SURE HOW WEDNESDAY/S CONVECTION CHANGES
THE AIRMASS ACROSS THE REGION. WENT BELOW MODEL GUIDANCE
TEMPERATURES.
FRIDAY...ANOTHER ROUND OF SEVERE THUNDERSTORMS...POSSIBLY WITH
SIGNIFICANT SEVERE...MAY RETURN TO THE AREA. VERY STRONG
SHEAR/WINDS WOULD SUPPORT FAST MOVING SUPERCELLS. HOWEVER...
MOISTURE AND INSTABILITY REMAIN QUESTIONABLE...ESPECIALLY AS
CONVECTION OVER TEXAS MAY LIMIT THE NORTHWARD PROGRESS OF RICHEST
MOISTURE AND HIGHEST INSTABILITY. REGARDLESS...WILL CLOSELY
MONITOR. ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS ALONG WITH
WINDY AND HOT WEATHER MAY FORM BEHIND A DRYLINE.
SATURDAY THROUGH MONDAY...A QUIETER WEATHER PATTERN IS FORECAST
WITH NEAR AVERAGE TEMPERATURES.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 77 54 69 54 / 20 20 50 40
HOBART OK 77 54 73 54 / 10 40 70 40
WICHITA FALLS TX 78 57 76 57 / 10 20 40 40
GAGE OK 79 49 66 46 / 10 40 40 30
PONCA CITY OK 78 49 64 47 / 20 30 30 30
DURANT OK 76 57 75 60 / 30 10 60 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17
AREA FORECAST DISCUSSION
NWS MEDFORD OR
257 PM PDT TUE APR 21 2015
.SHORT TERM...VISIBLE SATELLITE SHOWS THE ATMOSPHERE HAS
DESTABILIZED AS EXPECTED WITH NUMEROUS CUMULUS BUILDUPS OVER THE
HIGHER TERRAIN AND EAST SIDE. RADAR IS ALREADY SHOWING RETURNS IN
EASTERN SISKIYOU, NORTHERN KLAMATH, AND CENTRAL LAKE COUNTIES.
THERE HAS EVEN BEEN A STRIKE OR TWO RECORDED IN EASTERN SISKIYOU
COUNTY JUST WEST OF TENANT. AND NUMEROUS STRIKES RECORDED JUST
SOUTH OF THE CWA IN LASSEN COUNTY. HI- RES, NEAR TERM MODELS LIKE
THE HRRR (HIGH RESOLUTION RAPID REFRESH) SHOW MOST OF THE ACTION
OVER MODOC, LAKE, AND FAR EASTERN KLAMATH COUNTIES LATER THIS
AFTERNOON. STEERING WINDS ARE FAIRLY LIGHT SO THESE STORMS WILL
LIKELY BE SLOW MOVERS RESULTING IN THE POTENTIAL FOR SOME HEAVIER
DOWNPOURS UNDER THE CORE OF THESE STORMS. ALSO EXPECT SOME GUSTY
OUTFLOW WINDS WITH THE STRONGER STORMS ALONG WITH THE POTENTIAL
FOR SMALL HAIL. MODELS CONTINUE TO SHOW THE ATMOSPHERE STABILIZING
WITH THE LOSS OF DIURNAL HEATING SO CONVECTION SHOULD DIMINISH BY
TONIGHT. THE ATMOSPHERE WEST OF THE CASCADES IS MORE STABLE WITH
WEAKER LAPSE RATES SO NOT EXPECTING ANY THUNDERSTORMS FOR THAT
AREA.
ASIDE FROM THE RAIN EXPECTED WITH THE CONVECTION PREVIOUSLY MENTIONED,
MOST AREAS WILL REMAIN DRY WITH THE PASSAGE OF THE COLD FRONT.
WINDS WILL BE QUITE BREEZY THROUGH THE AFTERNOON IN RESPONSE TO
THIS COLD FRONT MOVING THROUGH THE AREA. THE UPPER LEVEL TROUGH
MOVES THROUGH OVERNIGHT INTO TOMORROW AND DRIER, MORE STABLE AIR
MOVES IN BEHIND IT FOR WEDNESDAY. WEAK RIDGING STARTS TO BUILD
OVER THE AREA WEDNESDAY NIGHT, BUT THIS IS SHORT LIVED AS A WEAK
TROUGH APPROACHES THE AREA THURSDAY MORNING. THERE IS A CHANCE FOR
SOME SHOWERS THURSDAY AFTERNOON, BUT THIS LOOKS MOSTLY CONFINED
FROM THE UMPQUA DIVIDE AND NORTH.
AN UPPER LOW MOVES IN OVER BRITISH COLUMBIA THURSDAY EVENING AND
SHORTWAVES ROTATING AROUND IT CONTINUE THE CHANCE FOR PRECIPITATION
FOR MOST OF THE AREA THROUGH SATURDAY MORNING.
.LONG TERM...SATURDAY THROUGH TUESDAY...THE OPERATIONAL EC AND
GFS ARE IN SIMILAR AGREEMENT WITH THE OVERALL PATTERN FRIDAY INTO
NEXT WEEKEND. HOWEVER THERE IS DISAGREEMENT WITH THE PLACEMENT AND
STRENGTH OF THE UPPER LOW FRIDAY. THE EC IS STRONGER AND FURTHER
SOUTH WITH THE UPPER LOW AND WETTER. HAVE KEPT IN A CHANCE OF
SHOWERS FOR MOST OF THE FORECAST AREA...THOUGH RAIN AND MOUNTAIN
SNOW AMOUNTS SHOULD BE LIGHT. THE TROUGH AXIS SHIFTS EAST FRIDAY
NIGHT AND RIDGING WILL ATTEMPT TO MOVE IN FROM THE SOUTHWEST. THE
GFS SHOWS MORE OF A DIRTY RIDGE SCENARIO WITH WARM FRONTAL
PRECIPITATION MOVING INTO THE AREA. THE EC HAS A MORE PRONOUNCED
RIDGE AND THUS SHOWS A DRY AND MILDER SOLUTION. SUSPECT THE WARM
FRONTAL PRECIPITATION IS OVERDONE, BUT DID NOT WANT TO DISCOUNT IT
COMPLETELY, SO WITH WITH A BLEND BETWEEN THE EC AND GFS WITH A
SLIGHTLY DRIER BIAS.
A DIRTY RIDGE REMAIN OVER THE AREA SUNDAY WITH THE BEST CHANCE FOR
PRECIPITATION OVER THE NORTHERN PART OF THE CWA. ESPECIALLY WEST OF
THE CASCADES AND NORTH OF THE UMPQUA DIVIDE.
SIGNIFICANT UPPER TROUGHING THAT`S BEEN HANGING OVER THE NORTHEAST
PACIFIC FINALLY REACHES THE FORECAST AREA WITH SIGNIFICANT RAIN
POTENTIALLY MONDAY INTO TUESDAY. THAT SAID...THERE IS SOME
UNCERTAINTY AS TO WHEN THIS TROUGHING REACHES THE AREA. ENSEMBLE
MEMBERS ARE OUT OF PHASE...BUT NOT AS MUCH AS YESTERDAY WITH THE
TROUGH AXIS STARTING TO DROP SOUTH. IN CONTRAST, THE OPERATIONAL EC
SHOWS MORE OF A SPLIT FLOW PATTERN NEAR 150 W AND MORE RIDGING IN
OUR AREA, THUS DELAYING ANY SIGNIFICANT PRECIPITATION.
IN SHORT...CONFIDENCE IS LOW TO MODERATE IN THE EXTENDED PERIOD AND
DID NOT MAKE ANY SIGNIFICANT CHANGES.
&&
.AVIATION...FOR THE 21/18Z TAF CYCLE...MVFR CONDITIONS WITH TERRAIN
OBSCURATIONS ARE EXPECTED FROM THE UMPQUA BASIN AND COASTAL
MOUNTAINS WESTWARD INTO TONIGHT. FURTHER INLAND GUSTY NORTHWEST
WINDS WILL DEVELOP THIS AFTERNOON THROUGH THIS EVENING WITH
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS EXPECTED FROM THE
OREGON CASCADES AND CALIFORNIA TRINITY ALPS EASTWARD. IT`S POSSIBLE
THUNDERSTORMS COULD RESULT IN TEMPORARY MVFR CIGS WITH MOUNTAINS
PARTLY OBSCURED BETWEEN 23Z AND 04Z. -PETRUCELLI
&&
.MARINE...UPDATED 300 PM PDT TUESDAY APR 21, 2015...HIGH PRESSURE
WILL BUILD INTO THE AREA TONIGHT BUT THIS WILL RESULT IN GUSTY NORTH
WINDS AND STEEP TO VERY STEEP SEAS. GALES AND WARNING LEVEL SEAS ARE
EXPECTED AT TIMES SOUTH OF CAPE BLANCO TONIGHT THROUGH WEDNESDAY
NIGHT. THURSDAY THROUGH THE WEEKEND...A SERIES OF FRONTAL SYSTEMS IS
LIKELY TO MOVE THROUGH WITH BUILDING SWELL. NORTHWEST WINDS
WEDNESDAY NIGHT THROUGH FRIDAY ARE EXPECTED TO BECOME SOUTHWESTERLY
THIS WEEKEND. SPILDE
&&
.FIRE WEATHER....FIRE WEATHER...UPDATED 3 PM PDT TUESDAY, APRIL
21ST, 2015... THE ATMOSPHERE IS ALREADY STARTING TO BECOME
UNSTABLE AHEAD OF A RATHER SHARP, BUT NOT STRONG, INCOMING TROUGH
OF LOW PRESSURE. A FEW ISOLATED STORMS HAVE DEVELOPED IN NORTHERN
CAL AND NORTHERN KLAMATH COUNTY NORTHEAST OF CHEMULT. THE LATEST
HRRR REFLECTIVITY PRODUCT SHOWS MOST OF THE ACTIVITY DEVELOPING IN
NORTHERN CAL, THEN MIGRATING NORTH INTO PARTS OF LAKE AND KLAMATH
COUNTIES LATE THIS AFTERNOON THROUGH THIS EVENING. UNLIKE THE HIGH
IMPACT LIGHTNING EVENTS THAT SOMETIMES AFFECT OUR REGION MAINLY IN
THE SUMMER, FORCING WITH THE INCOMING SYSTEM IS WEAK IN THAT THERE
IS NO CLEAR COLD POOL MOVING THROUGH. INSTEAD, A WEAK SURFACE
FRONT IS EXPECTED TO DEVELOP ALONG AND NEAR THE CASCADES THIS
AFTERNOON. THIS SHOULD GIVE RISE TO BUILD-UPS ALONG AND NEAR THE
TRINITY ALPS AND CASCADE CREST THIS AFTERNOON, SHIFTING EASTWARD
TO THE LEE OF THE CASCADES TOWARDS THE EVENING. CONDITIONS ARE
MOST FAVORABLE FOR SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN
THESE LEE AND EAST SIDE AREAS. MOST GUIDANCE FOCUSES ACTIVITY THIS
EVENING IN THE WARNER MOUNTAINS OF LAKE COUNTY AND ANOTHER IN
NORTHERN LAKE COUNTY THIS EVENING. WHILE FIRE DANGER DID REACH
HIGH IN PORTIONS OF THE MODOC ON MONDAY, FORECAST FIRE DANGER FOR
TODAY IS MODERATE. ADDITIONALLY, DEPARTURE FROM AVERAGE GREENNESS
IS SPOTTY IN TERMS OF DEFICITS, SO SUSPECT THERE`S SOME GREEN-UP
COMPONENT TO THE LIVE FUELS NOW. MODELS INDICATE THAT ANY STORMS
THAT DO GET GOING WILL PRODUCE GUSTY OUTFLOW WINDS MAINLY IN THE
20 TO 30 MPH RANGE, BUT ALSO SOME MEASURABLE RAINFALL. THUS,
DESPITE UNUSUALLY DRY CONDITIONS DUE TO THE ONGOING DROUGHT, WE
HAVE DECIDED THAT THIS EVENT DOES NOT WARRANT ANY WARNINGS.
INSTEAD, A HEADS-UP TYPE OF HEADLINE WILL BE MAINTAINED IN THE
FORECAST. BTL/PETRUCELLI
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT THURSDAY FOR
PZZ350-356-370-376.
HAZARDOUS SEAS WARNING UNTIL 5 AM PDT THURSDAY FOR PZZ356-376.
GALE WARNING UNTIL 5 AM PDT THURSDAY FOR PZZ356-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT THURSDAY
FOR PZZ350-356-370-376.
$$
MND/MAP/MAS
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
802 PM EDT WED APR 22 2015
.DISCUSSION...DID AN EARLY UPDATE TO DROP LATE AFTERNOON PERIOD
AND TO UPDATE THE GRIDS TO ADDRESS THE LINGERING CONVECTION OVER
SRN MIDDLE TN SOUTH INTO NRN AL AND NW GA. THIS ACTIVITY IS SHOWN
BY THE LATEST HRRR MODEL RUN TO PASS ACROSS SE TN AND SW NC THROUGH
ABOUT 04Z. STILL SOME LIGHTNING NOTED WITH CAPES OF AROUND 500 J/KG
ALONG THE TN STATELINE TO 1000 J/KG OVER NRN AL/NW GA.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 47 67 42 69 / 20 10 10 30
KNOXVILLE MCGHEE TYSON AIRPORT, TN 42 63 36 68 / 10 0 0 10
OAK RIDGE, TN 41 64 36 68 / 10 0 0 20
TRI CITIES AIRPORT, TN 37 62 32 65 / 10 0 0 10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
937 PM CDT WED APR 22 2015
.DISCUSSION...
WOW! THE SUPERCELL THAT MOVED OFF THE COAST ACROSS THE SAN ANTONIO
BAY AREA EARLIER THIS EVENING MADE IT ALL THE WAY OVER TO BUOY 42019...
AND AT 729 PM CDT PRODUCED A WIND GUST OF 76 KNOTS (87 MPH)! THIS WAS
THE SAME STORM THAT EARLIER PRODUCED LARGE HAIL AND WIND DAMAGE ALONG
THE WEST END OF SAN ANTONIO BAY (REFUGIO AND ARANSAS COUNTY AREA).
THERE WILL CONTINUE TO BE A CHANCE OF SHOWERS/THUNDERSTORMS ACROSS PARTS
OF OUR AREA OVERNIGHT...ESPECIALLY UP NORTH DURING THE REST OF THE EVENING
HOURS...AS ACTIVITY HEADS OUR WAY. 42
&&
.PREV DISCUSSION... /ISSUED 712 PM CDT WED APR 22 2015/
DISCUSSION...
00Z AVIATION DISCUSSION BELOW.
AVIATION...
THIS EVENING`S SUPERCELL THAT MOVED OFF THE UPPER TEXAS COAST AND
ACROSS SAN ANTONIO BAY APPEARS TO HAVE ROBBED INFLOW INTO THE
ONCE RAGGED SOUTHWESTERN FORECAST AREA`S CONVECTION THAT WAS
MOVING EAST AN HOUR AGO. ALL THAT IS LEFT IS A LIGHT RAIN SHIELD
CURRENTLY AFFECTING LBX...THIS LIGHT PRECIPITATION MOVING SOUTH
OF THE METRO TERMINALS. VFR DECKS THIS EVENING WILL LOWER BACK TO
MVFR JUST BEFORE SUNRISE. A LIGHT SOUTH BREEZE WITH CEILINGS
LIFTING BACK UP TO VFR BY LATE THURSDAY MORNING. UPPER RIDGING
FORMING JUST DOWNSTREAM OF NEXT BAJA REGION TROUGH SHOULD PROVIDE
ENOUGH SUBSIDENCE TO KEEP THURSDAY DRY. REGIONAL PROG SOUNDINGS
DEPICT A DRYING COLUMN...ESPECIALLY IN THE MID-LAYERS...AND NO
DISCERNIBLE APPROACHING UPSTREAM SHORTWAVE DISTURBANCE AID IN
LEANING THIS TAF PACKAGE TOWARDS A DRY BIAS. 31
PREV DISCUSSION... /ISSUED 402 PM CDT WED APR 22 2015/
DISCUSSION...
UPPER AIR ANALYSIS AND WATER VAPOR IMAGERY STILL SHOW A RATHER
PERSISTENT SOUTHERN JET STREAM OVER MUCH OF TX. IT IS HARD TO
IDENTIFY BUT IT APPEARS THAT THE CONVECTION OVER THE COASTAL BEND
AND NOW EAST OF SAN ANTONIO MAY BE SUPPORTED BY A WEAK SHORTWAVE
TROUGH. OVERALL PATTERN SHOWS WEAK SHORT WAVE RIDGING BUT THIS
DISTURBANCE MAY BE FLATTENING OUT THE RIDGE A BIT TODAY.
THERMODYNAMIC AND SHEAR PARAMETERS SUPPORT THE THREAT FOR SEVERE
STORMS WITH SOME STORMS BECOMING ORGANIZED. SHEAR WILL SUPPORT
STORM ROTATION AND LOW LEVEL TURNING OF THE WINDS WITH A
DEVELOPING WARM FRONT MAY BE ENOUGH TO SUPPORT LOW LEVEL ROTATION
IN STORMS ESPECIALLY ALONG THE COASTAL BEND. RECENT RAP/HRRR MODEL
RUNS BRING CONVECTION EAST OF KSAT INTO SE TX AROUND 23-01Z.
MODELS SHOW THAT STORMS MAY BE WEAKENING BUT COULD BE MOVING INTO
A MORE FAVORABLE ENVIRONMENT GIVEN TRENDS IN HEATING/INSTABILITY.
MODELS ALSO SHOW CONVECTION ALONG A BOUNDARY STRETCHING NW/SE FROM
MINERAL WELLS TO LUFKIN. THIS HIGHLIGHTS THE SEVERE THREAT FOR THE
NORTHERN MOST COUNTIES IN THE FORECAST AREA MAINLY
MADISON...HOUSTON...TRINITY CO. THE IDEA IS FOR THE THREAT TO END
LATER TONIGHT BUT HRRR TRENDS SHOW CONVECTION COMING DOWN FROM
THE METROPLEX AND AFFECT THE AREAS FROM COLLEGE STATION TO
HUNTSVILLE OVER THE LIVINGSTON BY EARLY MORNING HOURS. SO IT
APPEARS THERE WILL BE AT LEAST SOME OVERNIGHT THREAT.
THURSDAY LOOKS A BIT MORE QUIET AS MODELS DO AMPLIFY RIDGING OVER
THE REGION ALTHOUGH THERE WILL BE PLENTY OF MOISTURE/INSTABILITY
TO SUPPORT SEVERE STORMS. WE DO NOT WANT TO BE COMPLACENT BUT
THINK 20/30 POPS MIGHT BE GENEROUS. MOVING AHEAD TO
FRIDAY...RIDGING MOVES EAST IN RESPONSE TO UPPER LEVEL TROUGH OVER
THE S ROCKIES PUSHING INTO THE TX PANHANDLE AND S PLAINS. SFC LOW
DEEPENS AND MOVES INTO THE C PLAINS IN RESPONSE WITH STRONG JET
STREAK FROM MIDLAND TO OKC. THIS PUTS SE TX ON A MORE SUBSIDENT
SIDE OF THE JET BUT THAT MAY NOT MATTER MUCH WITH THE CURVATURE OF
THE JET. THERE IS ALSO A PACIFIC FRONT THAT DEVELOPS WITH
CONVECTION FORMING IN C TX MOVING EAST. THIS WILL AGAIN PUT AREAS
NORTH OF I-10 IN A THREAT FOR SEVERE WEATHER SINCE THERE WILL
AGAIN BE PLENTY OF MOISTURE/INSTABILITY AND SHEAR. MAIN QUESTION
WILL BE CAP STRENGTH. 850MB WINDS VEER TO SW WITH TEMPS AROUND 20C
OR MORE FOR MUCH OF THE SOUTHERN HALF OF THE AREA. AGAIN THIS
SUPPORTS IDEA OF AREAS NORTH OF I-10 OR EVEN NORTH OF CONROE WILL
HAVE A HIGHER THREAT FOR SEVERE WEATHER FRIDAY.
WE CONTINUE THUNDERSTORM CHANCES SATURDAY AS THE THROUGH PASSES NE
OF THE AREA OVERNIGHT. SOUTHERN JET STILL IS STRONG OVER THE
REGION. PACIFIC FRONT STALLS OVER THE AREA WHICH COULD SUPPORT A
FEW STORMS BUT WITH 850MB FLOW BECOMING MORE WSW...THINK STORMS
WILL BE ISO IN NATURE. WITH THE VEERED BOUNDARY LAYER FLOW...MAX
TEMPS COULD REACH UPPER 80S TO 90F BOTH SAT/SUN.
WHILE THERE MAY BE A BREAK FROM SEVERE WEATHER OVER THE
WEEKEND...MONDAY COULD BE ACTIVE AGAIN. BOTH GFS/ECMWF BRING A
UPPER LOW INTO THE PLAINS DURING THE DAY MON WITH FAVORABLE
SPLITTING JET STRUCTURE. LARGE SCALE ASCENT WILL BE STRONG ENOUGH
TO ERODE ANY CAPPING LEADING TO A MID MORNING TO EARLY AFTERNOON
SEVERE WEATHER CHANCES. DRYLINE/PACIFIC FRONT PUSHES THROUGH MON
NIGHT INTO TUE AS THUNDERSTORM ACTIVITY MOVES EAST. A STRONGER
COLD FRONT PUSHES THROUGH TUESDAY WHICH MUCH COLDER AIR BEHIND IT.
IN FACT THE 850MB TEMPS DROP TO ANYWHERE BETWEEN 4C AND 8C TUE
NIGHT INTO WED DEPENDING ON THE MODEL. SO IT LOOKS LIKE MONDAY
WILL NEED TO BE WATCHED CLOSELY FOR DETAILS ON SEVERE WEATHER BUT
GOOD NEWS THAT THERE COULD BE A STRONG COLD FRONT TO PUSH THROUGH
ONE LAST TIME BEFORE HEADING INTO THE MONTH OF MAY. 39
MARINE...
AS HIGH PRESSURE LINGERS TO THE EAST AND PRESSURES FALL OVER THE SRN
PLAINS...THE LIGHT/MODERATE ONSHORE FLOW WILL BE CONTINUING OVER THE
UPPER TX COAST THROUGH THE END OF THE WEEK/INTO THE WEEKEND. STRONG-
ER GUSTS/LIMITED VISIBILITIES POSSIBLE WITH STORMS DEVELOPING ACROSS
THE COASTAL WATERS THE REST OF THIS AFTN/EVENING...WITH LATER ROUNDS
OF PCPN POSSIBLE THURS AND FRI. LONG-RANGE MODELS STILL GOING WITH A
STRONG COLD FRONT INTO THE GULF WATERS NEXT TUES. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 70 85 71 83 68 / 40 30 30 60 20
HOUSTON (IAH) 69 86 73 84 71 / 30 20 20 40 20
GALVESTON (GLS) 72 82 73 82 73 / 20 20 20 30 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...42
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
733 PM CDT WED APR 22 2015
.UPDATE...
CURRENT FORECAST IS IN DECENT SHAPE. WILL LEAVE 20/30 POPS IN THE
FORECAST BUT OVERALL CHANCES FOR ADDITIONAL PRECIP IS LOW GIVEN
THE ATMOSPHERE IS PRETTY WORKED OVER FROM THE EARLIER CONVECTION.
AREAS SOUTH OF SAN ANTONIO RECEIVED BETWEEN 1-2 INCHES ACROSS A
LARGE AREA. OTHERWISE...MADE MINOR ADJUSTMENTS TO THE HOURLY
GRIDS FOR CURRENT TRENDS.
HAMPSHIRE
&&
.PREV DISCUSSION... /ISSUED 700 PM CDT WED APR 22 2015/
AVIATION.../00Z TAF CYCLE/
CENTRAL TAF SITES OF KAUS/KSAT/KSSF ARE MVFR WITH KDRT VFR AS OF
23/00Z. SOME ISOLATED -SHRA EXIST TO THE SE OF THE MAJOR TAF SITES
AND HAVE NOT DIRECTLY INCLUDED THEM BUT KSSF WILL BE CLOSEST TO
ACTIVITY OVER THE NEXT COUPLE OF HOURS. CLOUD CIGS WILL FALL
OVERNIGHT TO IFR AND POSSIBLY TO LIFR BY 12Z. KSSF/KSAT/KDRT WILL
IMPROVE MORE QUICKLY THAN KAUS THROUGH THE MID TO LATE MORNING TO
HIGH END MVFR AND THEN VFR THROUGH THE AFTERNOON. KAUS WILL LIKELY
STAY MVFR THROUGH THE EARLY AFTERNOON BEFORE IMPROVING TO VFR BY
MID AFTERNOON. SHRA/TSRA COVERAGE WILL BE LESS DURING THE DAY
THURSDAY BUT COVERAGE SHOULD EXPAND INTO THE LATE EVENING THROUGH
FRIDAY MORNING. SOME STORMS COULD BE STRONG TO SEVERE AND MAY
APPROACH TERMINALS THROUGH 12Z FRIDAY. /ALLEN/
PREV DISCUSSION... /ISSUED 231 PM CDT WED APR 22 2015/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
SEMI ACTIVE WEATHER PATTERN FOR THE NEXT FEW DAYS FOLLOWED BY A
FRONT THIS WEEKEND THEN DRYING OUT EARLY NEXT WEEK.
AS OF 2 PM THERE IS A MULTICELL CLUSTER OF THUNDERSTORMS
APPROACHING BEXAR COUNTY AND SAN ANTONIO. THE HRRR TAKES THIS
COMPLEX AS WELL AS OTHER SHOWERS AND THUNDERSTORMS OUT AHEAD OF IT
EASTWARD IMPACTING A BASTROP SOUTH TO GONZALES AND KENEDY LINE.
MODEL SOUNDINGS FROM THE NAM SHOW AN UNCAPPED ATMOSPHERE ALONG
AND EAST OF I-35 THIS AFTERNOON WITH 1000-3000 J/KG OF CAPE AND
50-60 KNOTS OF SHEAR. THIS MEANS THAT THIS COMPLEX OF STORMS IS
MOVING INTO A VERY GOOD ENVIRONMENT FOR STRONG TO SEVERE STORMS.
WE CONTINUE UNDER A SLIGHT RISK FROM SPC THIS AFTERNOON ALONG AND
EAST OF US HWY 281. WE HAVE ALSO SEEN HEAVY RAINFALL RATES OUT OF
THE ONGOING STORMS SO SOME LOCALIZED FLOODING IS NOT OUT OF THE
QUESTION WITH THE STRONGER STORMS. THE MAIN THREATS WILL BE LARGE
HAIL AND DAMAGING WINDS WITH ANY SEVERE WEATHER THAT DOES OCCUR
THIS AFTERNOON AND EVENING. THE THREAT FOR TORNADOES REMAINS LOW
AS LOW LEVEL SHEAR IS WEAK.
OTHER FEATURES IN PLAY TODAY ARE A STATIONARY FRONT ACROSS THE
RED RIVER IN NORTH TEXAS AND THE DRYLINE OUT IN WEST
TEXAS...ALTHOUGH OTHER THAN AN ISOLATED DRYLINE STORM NEITHER WILL
IMPACT OUR WEATHER MUCH. GENERAL RIDGING IS FORECAST TO TAKE
PLACE THROUGH THE PERIOD AS HIGH PRESSURE OVER NORTHERN MEXICO
MOVES SLOWLY EAST. CONVECTION WILL DECREASE OVERNIGHT TONIGHT AND
WITH NORTHWEST FLOW CONTINUING ONLY SLIGHT CHANCES FOR
PRECIPITATION ARE FORECAST FOR THURSDAY THROUGH THURSDAY EVENING.
MODEL SOUNDINGS SHOW A STRONG CAP ACROSS MOST OF SOUTH CENTRAL
TEXAS DURING THE DAY TOMORROW. BY LATE IN THE AFTERNOON MODELS DO
WEAKEN THE CAP WHICH COULD ALLOW FOR SOME ISOLATED SHOWERS AND
THUNDERSTORMS. AGAIN...CONDITIONS WILL BE FAVORABLE TOMORROW FOR
SEVERE WEATHER WITH 50 KNOTS OF UPPER LEVEL SHEAR AND 2000-3000
J/KG OF CAPE. THE DAY 2 OUTLOOK FROM SPC HAS THE WHOLE AREA IN A
SLIGHT RISK FOR TOMORROW...WITH LARGE HAIL AND DAMAGING WINDS
AGAIN THE PRIMARY THREATS.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
MODELS ARE IN AGREEMENT THAT THURSDAY NIGHT THROUGH FRIDAY MORNING
WILL BE A PERIOD OF HIGHER QPF...HIGHER RAIN CHANCES. THE GREATEST
CHANCES FOR RAIN WILL BE ALONG THE RIO GRANDE PLAINS THURSDAY
NIGHT SPREADING TO AREAS ALONG AND EAST OF I-35 FOR FRIDAY. AN
UPPER LEVEL TROUGH APPROACHING FROM THE WEST WILL PROVIDE THE
NEEDED LIFT FOR THIS PRECIPITATION. CHANCES OF SEVERE WEATHER
CONTINUE INTO FRIDAY WITH THE BEST INSTABILITY LOCATED ALONG AND
WEST OF I-35. AS THE TROUGH MOVES OFF TO THE EAST AND NORTHEAST
SATURDAY CHANCES FOR RAIN WILL DECREASE THROUGH THE DAY. THE NEXT
FRONT WILL MOVE THROUGH SUNDAY INTO MONDAY. THE GFS AND NEW 12Z
ECMWF DISAGREE BY ABOUT 24 ON THE TIMING OF THIS FRONT...WITH THE
ECMWF BRING THE SLOWER OF THE TWO. WILL GO WITH A PERSISTENCE
FORECAST AND CHANCE POPS FOR SUNDAY AND MONDAY...DRYING OUT
TUESDAY. THE ONE BENEFIT OF THIS FRONT IS IT WILL COOL THE AREA
BACK DOWN INTO THE 70S FOR HIGHS FOR A FEW DAYS BY THE MIDDLE OF
NEXT WEEK.
TREADWAY
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 70 88 70 85 67 / 30 30 40 60 30
AUSTIN BERGSTROM INTL AIRPORT 69 87 70 84 66 / 30 30 40 50 30
NEW BRAUNFELS MUNI AIRPORT 69 88 71 85 67 / 20 20 40 50 40
BURNET MUNI AIRPORT 67 87 68 84 64 / 30 40 40 60 20
DEL RIO INTL AIRPORT 69 90 68 88 64 / 10 20 50 30 30
GEORGETOWN MUNI AIRPORT 69 87 70 84 65 / 30 40 40 60 20
HONDO MUNI AIRPORT 70 88 71 85 66 / 20 20 40 40 50
SAN MARCOS MUNI AIRPORT 69 87 70 84 67 / 20 30 40 50 40
LA GRANGE - FAYETTE REGIONAL 70 87 72 85 69 / 30 30 30 50 40
SAN ANTONIO INTL AIRPORT 70 88 71 85 68 / 20 20 40 50 50
STINSON MUNI AIRPORT 71 88 71 85 69 / 20 20 40 40 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...15
SYNOPTIC/GRIDS...29
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
712 PM CDT WED APR 22 2015
.DISCUSSION...
00Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
THIS EVENING`S SUPERCELL THAT MOVED OFF THE UPPER TEXAS COAST AND
ACROSS SAN ANTONIO BAY APPEARS TO HAVE ROBBED INFLOW INTO THE
ONCE RAGGED SOUTHWESTERN FORECAST AREA`S CONVECTION THAT WAS
MOVING EAST AN HOUR AGO. ALL THAT IS LEFT IS A LIGHT RAIN SHIELD
CURRENTLY AFFECTING LBX...THIS LIGHT PRECIPITATION MOVING SOUTH
OF THE METRO TERMINALS. VFR DECKS THIS EVENING WILL LOWER BACK TO
MVFR JUST BEFORE SUNRISE. A LIGHT SOUTH BREEZE WITH CEILINGS
LIFTING BACK UP TO VFR BY LATE THURSDAY MORNING. UPPER RIDGING
FORMING JUST DOWNSTREAM OF NEXT BAJA REGION TROUGH SHOULD PROVIDE
ENOUGH SUBSIDENCE TO KEEP THURSDAY DRY. REGIONAL PROG SOUNDINGS
DEPICT A DRYING COLUMN...ESPECIALLY IN THE MID-LAYERS...AND NO
DISCERNIBLE APPROACHING UPSTREAM SHORTWAVE DISTURBANCE AID IN
LEANING THIS TAF PACKAGE TOWARDS A DRY BIAS. 31
&&
.PREV DISCUSSION... /ISSUED 402 PM CDT WED APR 22 2015/
DISCUSSION...
UPPER AIR ANALYSIS AND WATER VAPOR IMAGERY STILL SHOW A RATHER
PERSISTENT SOUTHERN JET STREAM OVER MUCH OF TX. IT IS HARD TO
IDENTIFY BUT IT APPEARS THAT THE CONVECTION OVER THE COASTAL BEND
AND NOW EAST OF SAN ANTONIO MAY BE SUPPORTED BY A WEAK SHORTWAVE
TROUGH. OVERALL PATTERN SHOWS WEAK SHORT WAVE RIDGING BUT THIS
DISTURBANCE MAY BE FLATTENING OUT THE RIDGE A BIT TODAY.
THERMODYNAMIC AND SHEAR PARAMETERS SUPPORT THE THREAT FOR SEVERE
STORMS WITH SOME STORMS BECOMING ORGANIZED. SHEAR WILL SUPPORT
STORM ROTATION AND LOW LEVEL TURNING OF THE WINDS WITH A
DEVELOPING WARM FRONT MAY BE ENOUGH TO SUPPORT LOW LEVEL ROTATION
IN STORMS ESPECIALLY ALONG THE COASTAL BEND. RECENT RAP/HRRR MODEL
RUNS BRING CONVECTION EAST OF KSAT INTO SE TX AROUND 23-01Z.
MODELS SHOW THAT STORMS MAY BE WEAKENING BUT COULD BE MOVING INTO
A MORE FAVORABLE ENVIRONMENT GIVEN TRENDS IN HEATING/INSTABILITY.
MODELS ALSO SHOW CONVECTION ALONG A BOUNDARY STRETCHING NW/SE FROM
MINERAL WELLS TO LUFKIN. THIS HIGHLIGHTS THE SEVERE THREAT FOR THE
NORTHERN MOST COUNTIES IN THE FORECAST AREA MAINLY
MADISON...HOUSTON...TRINITY CO. THE IDEA IS FOR THE THREAT TO END
LATER TONIGHT BUT HRRR TRENDS SHOW CONVECTION COMING DOWN FROM
THE METROPLEX AND AFFECT THE AREAS FROM COLLEGE STATION TO
HUNTSVILLE OVER THE LIVINGSTON BY EARLY MORNING HOURS. SO IT
APPEARS THERE WILL BE AT LEAST SOME OVERNIGHT THREAT.
THURSDAY LOOKS A BIT MORE QUIET AS MODELS DO AMPLIFY RIDGING OVER
THE REGION ALTHOUGH THERE WILL BE PLENTY OF MOISTURE/INSTABILITY
TO SUPPORT SEVERE STORMS. WE DO NOT WANT TO BE COMPLACENT BUT
THINK 20/30 POPS MIGHT BE GENEROUS. MOVING AHEAD TO
FRIDAY...RIDGING MOVES EAST IN RESPONSE TO UPPER LEVEL TROUGH OVER
THE S ROCKIES PUSHING INTO THE TX PANHANDLE AND S PLAINS. SFC LOW
DEEPENS AND MOVES INTO THE C PLAINS IN RESPONSE WITH STRONG JET
STREAK FROM MIDLAND TO OKC. THIS PUTS SE TX ON A MORE SUBSIDENT
SIDE OF THE JET BUT THAT MAY NOT MATTER MUCH WITH THE CURVATURE OF
THE JET. THERE IS ALSO A PACIFIC FRONT THAT DEVELOPS WITH
CONVECTION FORMING IN C TX MOVING EAST. THIS WILL AGAIN PUT AREAS
NORTH OF I-10 IN A THREAT FOR SEVERE WEATHER SINCE THERE WILL
AGAIN BE PLENTY OF MOISTURE/INSTABILITY AND SHEAR. MAIN QUESTION
WILL BE CAP STRENGTH. 850MB WINDS VEER TO SW WITH TEMPS AROUND 20C
OR MORE FOR MUCH OF THE SOUTHERN HALF OF THE AREA. AGAIN THIS
SUPPORTS IDEA OF AREAS NORTH OF I-10 OR EVEN NORTH OF CONROE WILL
HAVE A HIGHER THREAT FOR SEVERE WEATHER FRIDAY.
WE CONTINUE THUNDERSTORM CHANCES SATURDAY AS THE THROUGH PASSES NE
OF THE AREA OVERNIGHT. SOUTHERN JET STILL IS STRONG OVER THE
REGION. PACIFIC FRONT STALLS OVER THE AREA WHICH COULD SUPPORT A
FEW STORMS BUT WITH 850MB FLOW BECOMING MORE WSW...THINK STORMS
WILL BE ISO IN NATURE. WITH THE VEERED BOUNDARY LAYER FLOW...MAX
TEMPS COULD REACH UPPER 80S TO 90F BOTH SAT/SUN.
WHILE THERE MAY BE A BREAK FROM SEVERE WEATHER OVER THE
WEEKEND...MONDAY COULD BE ACTIVE AGAIN. BOTH GFS/ECMWF BRING A
UPPER LOW INTO THE PLAINS DURING THE DAY MON WITH FAVORABLE
SPLITTING JET STRUCTURE. LARGE SCALE ASCENT WILL BE STRONG ENOUGH
TO ERODE ANY CAPPING LEADING TO A MID MORNING TO EARLY AFTERNOON
SEVERE WEATHER CHANCES. DRYLINE/PACIFIC FRONT PUSHES THROUGH MON
NIGHT INTO TUE AS THUNDERSTORM ACTIVITY MOVES EAST. A STRONGER
COLD FRONT PUSHES THROUGH TUESDAY WHICH MUCH COLDER AIR BEHIND IT.
IN FACT THE 850MB TEMPS DROP TO ANYWHERE BETWEEN 4C AND 8C TUE
NIGHT INTO WED DEPENDING ON THE MODEL. SO IT LOOKS LIKE MONDAY
WILL NEED TO BE WATCHED CLOSELY FOR DETAILS ON SEVERE WEATHER BUT
GOOD NEWS THAT THERE COULD BE A STRONG COLD FRONT TO PUSH THROUGH
ONE LAST TIME BEFORE HEADING INTO THE MONTH OF MAY. 39
&&
MARINE...
AS HIGH PRESSURE LINGERS TO THE EAST AND PRESSURES FALL OVER THE SRN
PLAINS...THE LIGHT/MODERATE ONSHORE FLOW WILL BE CONTINUING OVER THE
UPPER TX COAST THROUGH THE END OF THE WEEK/INTO THE WEEKEND. STRONG-
ER GUSTS/LIMITED VISIBILITIES POSSIBLE WITH STORMS DEVELOPING ACROSS
THE COASTAL WATERS THE REST OF THIS AFTN/EVENING...WITH LATER ROUNDS
OF PCPN POSSIBLE THURS AND FRI. LONG-RANGE MODELS STILL GOING WITH A
STRONG COLD FRONT INTO THE GULF WATERS NEXT TUES. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 70 85 71 83 68 / 40 30 30 60 20
HOUSTON (IAH) 69 86 73 84 71 / 30 20 20 40 20
GALVESTON (GLS) 72 82 73 82 73 / 20 20 20 30 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...42
AVIATION/MARINE...31
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
700 PM CDT WED APR 22 2015
.AVIATION.../00Z TAF CYCLE/
CENTRAL TAF SITES OF KAUS/KSAT/KSSF ARE MVFR WITH KDRT VFR AS OF
23/00Z. SOME ISOLATED -SHRA EXIST TO THE SE OF THE MAJOR TAF SITES
AND HAVE NOT DIRECTLY INCLUDED THEM BUT KSSF WILL BE CLOSEST TO
ACTIVITY OVER THE NEXT COUPLE OF HOURS. CLOUD CIGS WILL FALL
OVERNIGHT TO IFR AND POSSIBLY TO LIFR BY 12Z. KSSF/KSAT/KDRT WILL
IMPROVE MORE QUICKLY THAN KAUS THROUGH THE MID TO LATE MORNING TO
HIGH END MVFR AND THEN VFR THROUGH THE AFTERNOON. KAUS WILL LIKELY
STAY MVFR THROUGH THE EARLY AFTERNOON BEFORE IMPROVING TO VFR BY
MID AFTERNOON. SHRA/TSRA COVERAGE WILL BE LESS DURING THE DAY
THURSDAY BUT COVERAGE SHOULD EXPAND INTO THE LATE EVENING THROUGH
FRIDAY MORNING. SOME STORMS COULD BE STRONG TO SEVERE AND MAY
APPROACH TERMINALS THROUGH 12Z FRIDAY. /ALLEN/
&&
.PREV DISCUSSION... /ISSUED 231 PM CDT WED APR 22 2015/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
SEMI ACTIVE WEATHER PATTERN FOR THE NEXT FEW DAYS FOLLOWED BY A
FRONT THIS WEEKEND THEN DRYING OUT EARLY NEXT WEEK.
AS OF 2 PM THERE IS A MULTICELL CLUSTER OF THUNDERSTORMS
APPROACHING BEXAR COUNTY AND SAN ANTONIO. THE HRRR TAKES THIS
COMPLEX AS WELL AS OTHER SHOWERS AND THUNDERSTORMS OUT AHEAD OF IT
EASTWARD IMPACTING A BASTROP SOUTH TO GONZALES AND KENEDY LINE.
MODEL SOUNDINGS FROM THE NAM SHOW AN UNCAPPED ATMOSPHERE ALONG
AND EAST OF I-35 THIS AFTERNOON WITH 1000-3000 J/KG OF CAPE AND
50-60 KNOTS OF SHEAR. THIS MEANS THAT THIS COMPLEX OF STORMS IS
MOVING INTO A VERY GOOD ENVIRONMENT FOR STRONG TO SEVERE STORMS.
WE CONTINUE UNDER A SLIGHT RISK FROM SPC THIS AFTERNOON ALONG AND
EAST OF US HWY 281. WE HAVE ALSO SEEN HEAVY RAINFALL RATES OUT OF
THE ONGOING STORMS SO SOME LOCALIZED FLOODING IS NOT OUT OF THE
QUESTION WITH THE STRONGER STORMS. THE MAIN THREATS WILL BE LARGE
HAIL AND DAMAGING WINDS WITH ANY SEVERE WEATHER THAT DOES OCCUR
THIS AFTERNOON AND EVENING. THE THREAT FOR TORNADOES REMAINS LOW
AS LOW LEVEL SHEAR IS WEAK.
OTHER FEATURES IN PLAY TODAY ARE A STATIONARY FRONT ACROSS THE
RED RIVER IN NORTH TEXAS AND THE DRYLINE OUT IN WEST
TEXAS...ALTHOUGH OTHER THAN AN ISOLATED DRYLINE STORM NEITHER WILL
IMPACT OUR WEATHER MUCH. GENERAL RIDGING IS FORECAST TO TAKE
PLACE THROUGH THE PERIOD AS HIGH PRESSURE OVER NORTHERN MEXICO
MOVES SLOWLY EAST. CONVECTION WILL DECREASE OVERNIGHT TONIGHT AND
WITH NORTHWEST FLOW CONTINUING ONLY SLIGHT CHANCES FOR
PRECIPITATION ARE FORECAST FOR THURSDAY THROUGH THURSDAY EVENING.
MODEL SOUNDINGS SHOW A STRONG CAP ACROSS MOST OF SOUTH CENTRAL
TEXAS DURING THE DAY TOMORROW. BY LATE IN THE AFTERNOON MODELS DO
WEAKEN THE CAP WHICH COULD ALLOW FOR SOME ISOLATED SHOWERS AND
THUNDERSTORMS. AGAIN...CONDITIONS WILL BE FAVORABLE TOMORROW FOR
SEVERE WEATHER WITH 50 KNOTS OF UPPER LEVEL SHEAR AND 2000-3000
J/KG OF CAPE. THE DAY 2 OUTLOOK FROM SPC HAS THE WHOLE AREA IN A
SLIGHT RISK FOR TOMORROW...WITH LARGE HAIL AND DAMAGING WINDS
AGAIN THE PRIMARY THREATS.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
MODELS ARE IN AGREEMENT THAT THURSDAY NIGHT THROUGH FRIDAY MORNING
WILL BE A PERIOD OF HIGHER QPF...HIGHER RAIN CHANCES. THE GREATEST
CHANCES FOR RAIN WILL BE ALONG THE RIO GRANDE PLAINS THURSDAY
NIGHT SPREADING TO AREAS ALONG AND EAST OF I-35 FOR FRIDAY. AN
UPPER LEVEL TROUGH APPROACHING FROM THE WEST WILL PROVIDE THE
NEEDED LIFT FOR THIS PRECIPITATION. CHANCES OF SEVERE WEATHER
CONTINUE INTO FRIDAY WITH THE BEST INSTABILITY LOCATED ALONG AND
WEST OF I-35. AS THE TROUGH MOVES OFF TO THE EAST AND NORTHEAST
SATURDAY CHANCES FOR RAIN WILL DECREASE THROUGH THE DAY. THE NEXT
FRONT WILL MOVE THROUGH SUNDAY INTO MONDAY. THE GFS AND NEW 12Z
ECMWF DISAGREE BY ABOUT 24 ON THE TIMING OF THIS FRONT...WITH THE
ECMWF BRING THE SLOWER OF THE TWO. WILL GO WITH A PERSISTENCE
FORECAST AND CHANCE POPS FOR SUNDAY AND MONDAY...DRYING OUT
TUESDAY. THE ONE BENEFIT OF THIS FRONT IS IT WILL COOL THE AREA
BACK DOWN INTO THE 70S FOR HIGHS FOR A FEW DAYS BY THE MIDDLE OF
NEXT WEEK.
TREADWAY
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 70 88 70 85 67 / 30 30 40 60 30
AUSTIN BERGSTROM INTL AIRPORT 69 87 70 84 66 / 30 30 40 50 30
NEW BRAUNFELS MUNI AIRPORT 69 88 71 85 67 / 20 20 40 50 40
BURNET MUNI AIRPORT 67 87 68 84 64 / 30 40 40 60 20
DEL RIO INTL AIRPORT 69 90 68 88 64 / 10 20 50 30 30
GEORGETOWN MUNI AIRPORT 69 87 70 84 65 / 30 40 40 60 20
HONDO MUNI AIRPORT 70 88 71 85 66 / 20 20 40 40 50
SAN MARCOS MUNI AIRPORT 69 87 70 84 67 / 20 30 40 50 40
LA GRANGE - FAYETTE REGIONAL 70 87 72 85 69 / 30 30 30 50 40
SAN ANTONIO INTL AIRPORT 70 88 71 85 68 / 20 20 40 50 50
STINSON MUNI AIRPORT 71 88 71 85 69 / 20 20 40 40 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...15
SYNOPTIC/GRIDS...29
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
344 PM CDT TUE APR 21 2015
.SHORT TERM...
SURFACE DEWPOINTS HAVE BEEN FAIRLY STAGNANT ACROSS THE FORECAST AREA
TODAY AS MODEST ADVECTION BALANCES MIXING. AT 3 PM...SATELLITE
IMAGERY SHOWED A DEVELOPING CUMULUS FIELD IN EASTERN NEW MEXICO
WHERE THE DEWPOINTS ARE MOSTLY IN THE 30S. MORE EXTENSIVE
DEVELOPMENT WAS ONGOING ACROSS THE SACRAMENTOS AND SANGRES OF NM.
THE HRRR HAS BEEN FAIRLY CONSISTENT WITH BRINGING SOME OF THIS
ACTIVITY EASTWARD ACROSS THE WESTERN AND CENTRAL SOUTH PLAINS LATE
THIS AFTERNOON AND EVENING...ALTHOUGH IT IS ABOUT THE ONLY MODEL TO
DO SO. FCST SOUNDINGS IN THESE AREAS INDICATE ANY STORMS THAT DO
DEVELOP WILL BE HIGH-BASED HAVE LITTLE CAPE TO WORK WITH...SO THEY
WILL ONLY BE CAPABLE OF SPOTTY RAIN AND STRONG WIND GUSTS. IF ANY
STORMS CAN SURVIVE FARTHER TO THE EAST THIS EVENING AND ENCOUNTER
THE DEEPER MOISTURE...IT IS NOT OUT OF THE QUESTION THAT A HAIL
THREAT COULD DEVELOP...BUT THIS APPEARS UNLIKELY AT THIS TIME.
TONIGHT...THE LOW LEVEL JET WILL BRING RICHER MOISTURE NWWD INTO
WEST TEXAS...WITH THE SURFACE DRYLINE RETREATING THROUGH MOST IF NOT
ALL OF THE CWA...PERHAPS HOLDING BACK ACROSS THE FAR SW TX
PANHANDLE. NAM FCST SNDGS SHOW FOG POTENTIAL ACROSS THE SOUTHERN AND
CENTRAL SOUTH PLAINS BY EARLY WED MORNING SO WE HAVE ADDED A PATCHY
MENTION IN THE GRIDS....SOME AREAS OF LOW STRATUS ARE POSSIBLE AS
WELL. MEANWHILE TO OUR NORTH ACROSS THE PANHANDLES...THEY WILL
LIKELY SEE SOME OVERNIGHT TSTM ACTIVITY COINCIDING WITH A SWD-MOVING
COLD FRONT. IT IS UNCERTAIN WHAT IMPACT STORM COLD POOLS MAY HAVE ON
THE PROGRESS OF THE FRONT...WHICH TENDS TO LOWER OUR CONFIDENCE ON
HOW THE FRONT/OUTFLOW BOUNDARY WILL BEHAVE ON WEDNESDAY. IN
GENERAL...WE EXPECT THE BOUNDARY TO SINK SOUTH THROUGH THE FAR SRN
PANHANDLE AND POSSIBLY INTO THE NORTHERN ROLLING PLAINS. BACK TO THE
WEST...THE DRYLINE SHOULD FORM UP AND MOVE EAST AS A SURFACE TROUGH
DEVELOPS FROM EASTERN NM INTO THE ROLLING PLAINS. ALTHOUGH WE HAVE
TO STRESS A LARGE UNCERTAINTY IN THE PARTICULARS...A TRIPLE-POINT
MAY DEVELOP SOMEWHERE FROM OUR CENTRAL TO SOUTHEAST COUNTIES. BACKED
FLOW AND HIGH SURFACE MOISTURE WILL BE POSSIBLE ACROSS AT LEAST OUR
NE ZONES. WITH A MID-LVL SHORTWAVE PASSING ACROSS THE AREA DURING
THE DAY...STRONG INSTABILITY AND DEEP SHEAR IS LIKELY TO DEVELOP
ALONG AND TO THE NORTH AND EAST OF THE TRIPLE-POINT. GUIDANCE
GENERALLY SHOWS A STRONG CONVECTIVE SIGNAL IN THIS AREA BY LATE
AFTERNOON...ALTHOUGH WITH A LOT OF SPREAD RECORDING THE AREA
POTENTIALLY IMPACTED. WHERE STORMS OCCUR...SEVERE WEATHER WILL BE A
STRONG POSSIBILITY...INCLUDING THE POSSIBILITY OF TORNADOES
DEPENDING THE ORIENTATION/EVOLUTION ON THE BOUNDARY/S/. FARTHER
WEST...WE HAVE TRIMMED POPS DOWN OUR NEAR THE STATE LINE BUT LEFT A
SLIGHT CHANCE GOING ACROSS MUCH OF THE SOUTH PLAINS IN CASE THE
DRYLINE IS FARTHER WEST THAN ANTICIPATED.
.LONG TERM...
THE PATTERN THEME THROUGH EARLY NEXT WEEK REMAINS THAT OF A
PROGRESSIVE ONE AS A SERIES OF SOUTHERN STREAM TROUGHS IMPACT THE
REGION. ONLY UNTIL THEREAFTER DOES THE PATTERN SHOW SIGNS OF
TRENDING MORE STAGNANT IN THE FORM OF MID-CONUS LONGWAVE RIDGING.
ALL DAYS CONSIDERED...WEDNESDAY EVENING LOOKS TO GRAB THE LIMELIGHT
FOR SENSIBLE WEATHER AS A SEVERE CONVECTIVE EPISODE SHOULD BE WELL
UNDERWAY. LOCATION OF THIS EVENT WILL BE HIGHLY DEPENDENT ON A
STATIONARY FRONT CURRENTLY PROGGED TO BISECT OUR CWA FROM NW-SE BY
LATE EVENING...THOUGH MODELS CONTINUE TO FAVOR OUR NERN COUNTIES.
BACKGROUND FORCING APPEARS RATHER SUBDUED AND LINKED MOSTLY TO A
SHORTWAVE TROUGH CRESTING SHALLOW RIDGING ALOFT AND A NORTHWARD PUSH
OF STRONGER SUBTROPICAL WINDS. THIS ALONG WITH FAVORABLE DEEP SHEAR
MAY SERVE TO KEEP CONVECTIVE MODES RESTRICTED TO ISOLATED OR
SCATTERED SUPERCELLS. FEEL 40-50 PERCENT POPS WED EVENING ARE
REPRESENTATIVE OF THIS SCENARIO FOR NOW BEFORE PRECIP EVENTUALLY
MOVES DOWNSTREAM LATE WED NIGHT.
BEYOND WEDNESDAY NIGHT...THE WAVERING FRONTAL BOUNDARY SHOULD LIFT
NORTH AS A WARM FRONT IN ADVANCE OF A MORE ROBUST TROUGH LIFTING OUT
OF THE DESERT SOUTHWEST. THIS WAVE WILL PROJECT EVEN STRONGER WINDS
ATOP THE REGION PERHAPS ACCOMPANIED BY OCCASIONAL IMPULSES AND
SLIGHT CHANCE POPS...ESPECIALLY OFF THE CAPROCK WHERE LL MOISTURE
WILL HAVE A GREATER RESIDENCE TIME. MODEL CONSENSUS IS FOR DRY
SLOTTING TO SURGE ATOP THE CAPROCK COUNTIES BY EARLY FRIDAY AND
QUICKLY SWEEP EAST AS THE BASE OF THE TROUGH LIFTS TO OUR NORTH.
THE TIMING AND PATH OF THIS TROUGH SUGGEST A WINDY DAY IS IN STORE
YET WE REMAIN A BIT RELUCTANT TO BITE ON THE STRONG WINDS AS
PROGGED BY THE GFS AT TIMES. TIME-HEIGHT X-SECTIONS SHOW NEXT TO
NIL CIRRUS...SO WE MAY NEED TO RATCHET UP OUR 20-30 MPH WINDS
EVEN FURTHER IN LATER FORECASTS IF THIS THEME PERSISTS.
BY SATURDAY...QUIETER WEATHER UNDER TRANSIENT RIDGING WILL BE
REPLACED BY ONE FINAL TROUGH AT SOME POINT ON SUNDAY AHEAD OF
MODIFIED CANADIAN AIR WHICH LOOKS TO DIVE INTO THE GULF COME
MONDAY. PRECIP MERIT FROM SUN-SUN NIGHT DOESN/T SHOW MUCH
SUBSTANCE AMONG THE LATEST GLOBAL MODELS...SO POPS WERE SCALED
BACK IN COVERAGE TO BETTER MATCH THE DRIER SUPERBLEND AND
CONSENSUS ROUTES.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33/93
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
114 PM CDT TUE APR 21 2015
.AVIATION...
/18Z TAFS/
MVFR CIGS BETWEEN DRT AND SAT/SSF/AUS SHOULD CONTINUE TO LIFT AND
STAY CLEAR OF OUR TAF SITES THIS AFTERNOON. SOUTHEAST FLOW FROM
THE GULF HAS RETURNED...WHICH COMBINED WITH WEAK LIFT WILL LEAD
TO CIGS LOWERING TO MVFR AROUND 3-4Z AND IFR AROUND 8Z AT ALL TAF
SITES. MODEL GUIDANCE SUGGESTS LIFR CIGS WITH TEMPO VLIFR CIGS ARE
POSSIBLE TONIGHT AT SAT/SSF/DRT...BUT HELD OFF PREVAILING THAT FOR
NOW. ISOLATED -SHRA IS POSSIBLE TONIGHT WITH A STRENGTHENING LLJ
AND -TSRA IS POSSIBLE TOMORROW AFTERNOON...BUT CAPPING ALOFT WILL
LIKELY KEEP COVERAGE TOO ISOLATED TO MENTION IN TAFS.
LH
&&
.PREV DISCUSSION... /ISSUED 1201 PM CDT TUE APR 21 2015/
UPDATE...
INCREASING CLOUD COVER HAS KEPT TEMPERATURES DOWN SLIGHTLY FROM
FORECAST. THIS TREND WILL CONTINUE AS SOUTHERLY LOWER LEVEL FLOW
INCREASES MOISTURE. HAVE LOWERED HIGH TEMPERATURES A COUPLE OF
DEGREES IN MANY AREAS FOR THIS AFTERNOON. ALSO...DUE TO UPPER
LEVEL RIDGE BUILDING IN FROM THE SOUTH WILL SERVE TO INCREASE
CONVECTIVE INHIBITION. AS A RESULT...WILL REMOVE MENTION OF
THUNDER. HOWEVER...WILL MAINTAIN SHOWERS AS RADAR IS SHOWING A
BAND OF SHOWERS STREAMING INTO TOWARD OUR AREA FROM THE SOUTH.
PREV DISCUSSION... /ISSUED 652 AM CDT TUE APR 21 2015/
AVIATION...
/12Z TAFS/
CLEAR SKIES ARE IN PLACE AS UPPER LEVEL MOISTURE PUSHES TO THE
EAST AND LIGHT WINDS FROM THE NORTHWEST AND NORTHEAST DOMINATE AT
THE SURFACE. HOWEVER...THIS CONDITION IS FORECAST TO QUICKLY
CHANGE THIS MORNING AS SOUTHERLY WINDS RETURN. MVFR CONDITIONS ARE
EXPECTED ACROSS KSAT AND KSSF AROUND 14Z TO 16Z AS A POCKET OF LOW
CLOUDS FORM ACROSS THE SAN ANTONIO METRO AREA. CLOUDS WILL
INCREASE THROUGHOUT THE DAY AS GULF MOISTURE PUSHES NORTHWARD FOR
THE RETURN OF MVFR CONDITIONS ACROSS AREA SITES THIS EVENING. AREA
SOUNDINGS AND MOS GUIDANCE ARE SUGGESTING CIGS TO LOWER TO
IFR/LIFR OVERNIGHT AS SATURATED AIR DOMINATES THE AREA. WINDS WILL
BE FROM THE SOUTHEAST FOR THE MOST PARTS WITH SPEEDS OF 10 KNOTS
AND GUSTING UP TO 21 KNOTS ACROSS KDRT THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 442 AM CDT TUE APR 21 2015/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
A WEAK UPPER LEVEL DISTURBANCE MOVED OVER THE AREA OVERNIGHT AND
CLEARING SKIES ARE LEFT IN ITS WAKE. THE CLEARING SHOULD BE
TEMPORARY AS A MOIST LAYER AT 850 HPA SHOULD SATURATE IN MANY
AREAS. THE CLOUDS WILL PROBABLY BE SCT VARIABLE TO BKN SINCE THE
MOISTURE LAYER APPEARS THIN. THUS WILL GO WITH SLIGHTLY ABOVE
BLENDED GUIDANCE HIGHS TODAY. RAP SOUNDINGS SUGGEST A BREAKABLE
CAP SHOULD THERE BE ENOUGH MOISTURE SO WILL CONTINUE WITH ISOLATED
POPS. AN UPPER LOW CURRENTLY OVER SOUTHERN CA WILL CONTINUE TO
CARVE DEEPER OVER THE BAJA PENINSULA THROUGH WEDNESDAY. DEEPENING
MOISTURE WILL LEAD TO INCREASED RAIN CHANCES AND A FEW STRONG
STORMS AND POSSIBLE SUPERCELLS AS NOTED IN THE SPC DAY 2 OUTLOOK.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
A FAIRLY LIGHT LOW LEVEL FLOW WEDNESDAY NIGHT INTO THURSDAY MEANS
THAT THERE COULD BE SOME REMNANT OUTFLOW BOUNDARIES LEFT FROM
WEDNESDAY STORMS TO BRING ADDITIONAL STORM FOCUS FOR THURSDAY AS
THE UPPER LOW BEGINS TO LIFT INTO THE SOUTHERN ROCKIES. HIGHEST
POPS OF THE WEEK ARE THUS SAVED FOR THURSDAY NIGHT INTO FRIDAY.
THE EJECTION OF THE LOW INTO A SHALLOW TROUGH LEAVES SOME COVERAGE
UNCERTAINTIES THIS FAR SOUTH...SO DO NOT WANT TO OVER-ADVERTISE
THE SEVERE THREAT BEYOND A NOD IN THE HWO. POPS SHOULD LOWER
SATURDAY INTO SUNDAY AS FLAT RIDGING ALOFT RETURNS. MOISTURE IS
SUFFICIENT FOR STORMS...BUT EXPECT A STRONGER CAPPING INVERSION.
ANOTHER LOW LATITUDE UPPER DISTURBANCE IS FORECAST BY THE GFS TO
BRING RAIN AND STORMS BY MIDWEEK...BUT WILL KEEP WITH THE MORE
CONSERVATIVE ECMWF UNTIL THE PATTERN DIFFERENCES BETWEEN MODELS
DECREASE. TEMPERATURES THROUGH THE PERIOD SHOULD CONTINUE TO BE
SEASONAL. A WEAK FRONT EXPECTED SATURDAY WILL PROBABLY ADD TO
DAYTIME TEMPERATURES THROUGH REDUCED CLOUDINESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 80 66 82 69 86 / 10 20 40 20 20
AUSTIN BERGSTROM INTL AIRPORT 79 66 81 68 85 / 10 20 40 30 20
NEW BRAUNFELS MUNI AIRPORT 79 66 82 69 87 / 10 20 40 20 20
BURNET MUNI AIRPORT 77 66 81 68 85 / 10 20 30 20 20
DEL RIO INTL AIRPORT 81 67 86 70 88 / 10 30 20 10 20
GEORGETOWN MUNI AIRPORT 79 67 82 68 86 / 10 20 40 30 20
HONDO MUNI AIRPORT 80 67 82 69 87 / 10 30 30 10 20
SAN MARCOS MUNI AIRPORT 78 66 81 68 85 / 10 20 40 20 20
LA GRANGE - FAYETTE REGIONAL 79 66 82 70 85 / 10 20 40 30 20
SAN ANTONIO INTL AIRPORT 79 68 82 71 86 / 10 20 30 20 20
STINSON MUNI AIRPORT 81 68 82 71 87 / 10 20 30 10 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...01
SYNOPTIC/GRIDS...04
PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1201 PM CDT TUE APR 21 2015
.UPDATE...
INCREASING CLOUD COVER HAS KEPT TEMPERATURES DOWN SLIGHTLY FROM
FORECAST. THIS TREND WILL CONTINUE AS SOUTHERLY LOWER LEVEL FLOW
INCREASES MOISTURE. HAVE LOWERED HIGH TEMPERATURES A COUPLE OF
DEGREES IN MANY AREAS FOR THIS AFTERNOON. ALSO...DUE TO UPPER
LEVEL RIDGE BUILDING IN FROM THE SOUTH WILL SERVE TO INCREASE
CONVECTIVE INHIBITION. AS A RESULT...WILL REMOVE MENTION OF
THUNDER. HOWEVER...WILL MAINTAIN SHOWERS AS RADAR IS SHOWING A
BAND OF SHOWERS STREAMING INTO TOWARD OUR AREA FROM THE SOUTH.
&&
.PREV DISCUSSION... /ISSUED 652 AM CDT TUE APR 21 2015/
AVIATION...
/12Z TAFS/
CLEAR SKIES ARE IN PLACE AS UPPER LEVEL MOISTURE PUSHES TO THE
EAST AND LIGHT WINDS FROM THE NORTHWEST AND NORTHEAST DOMINATE AT
THE SURFACE. HOWEVER...THIS CONDITION IS FORECAST TO QUICKLY
CHANGE THIS MORNING AS SOUTHERLY WINDS RETURN. MVFR CONDITIONS ARE
EXPECTED ACROSS KSAT AND KSSF AROUND 14Z TO 16Z AS A POCKET OF LOW
CLOUDS FORM ACROSS THE SAN ANTONIO METRO AREA. CLOUDS WILL
INCREASE THROUGHOUT THE DAY AS GULF MOISTURE PUSHES NORTHWARD FOR
THE RETURN OF MVFR CONDITIONS ACROSS AREA SITES THIS EVENING. AREA
SOUNDINGS AND MOS GUIDANCE ARE SUGGESTING CIGS TO LOWER TO
IFR/LIFR OVERNIGHT AS SATURATED AIR DOMINATES THE AREA. WINDS WILL
BE FROM THE SOUTHEAST FOR THE MOST PARTS WITH SPEEDS OF 10 KNOTS
AND GUSTING UP TO 21 KNOTS ACROSS KDRT THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 442 AM CDT TUE APR 21 2015/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
A WEAK UPPER LEVEL DISTURBANCE MOVED OVER THE AREA OVERNIGHT AND
CLEARING SKIES ARE LEFT IN ITS WAKE. THE CLEARING SHOULD BE
TEMPORARY AS A MOIST LAYER AT 850 HPA SHOULD SATURATE IN MANY
AREAS. THE CLOUDS WILL PROBABLY BE SCT VARIABLE TO BKN SINCE THE
MOISTURE LAYER APPEARS THIN. THUS WILL GO WITH SLIGHTLY ABOVE
BLENDED GUIDANCE HIGHS TODAY. RAP SOUNDINGS SUGGEST A BREAKABLE
CAP SHOULD THERE BE ENOUGH MOISTURE SO WILL CONTINUE WITH ISOLATED
POPS. AN UPPER LOW CURRENTLY OVER SOUTHERN CA WILL CONTINUE TO
CARVE DEEPER OVER THE BAJA PENINSULA THROUGH WEDNESDAY. DEEPENING
MOISTURE WILL LEAD TO INCREASED RAIN CHANCES AND A FEW STRONG
STORMS AND POSSIBLE SUPERCELLS AS NOTED IN THE SPC DAY 2 OUTLOOK.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
A FAIRLY LIGHT LOW LEVEL FLOW WEDNESDAY NIGHT INTO THURSDAY MEANS
THAT THERE COULD BE SOME REMNANT OUTFLOW BOUNDARIES LEFT FROM
WEDNESDAY STORMS TO BRING ADDITIONAL STORM FOCUS FOR THURSDAY AS
THE UPPER LOW BEGINS TO LIFT INTO THE SOUTHERN ROCKIES. HIGHEST
POPS OF THE WEEK ARE THUS SAVED FOR THURSDAY NIGHT INTO FRIDAY.
THE EJECTION OF THE LOW INTO A SHALLOW TROUGH LEAVES SOME COVERAGE
UNCERTAINTIES THIS FAR SOUTH...SO DO NOT WANT TO OVER-ADVERTISE
THE SEVERE THREAT BEYOND A NOD IN THE HWO. POPS SHOULD LOWER
SATURDAY INTO SUNDAY AS FLAT RIDGING ALOFT RETURNS. MOISTURE IS
SUFFICIENT FOR STORMS...BUT EXPECT A STRONGER CAPPING INVERSION.
ANOTHER LOW LATITUDE UPPER DISTURBANCE IS FORECAST BY THE GFS TO
BRING RAIN AND STORMS BY MIDWEEK...BUT WILL KEEP WITH THE MORE
CONSERVATIVE ECMWF UNTIL THE PATTERN DIFFERENCES BETWEEN MODELS
DECREASE. TEMPERATURES THROUGH THE PERIOD SHOULD CONTINUE TO BE
SEASONAL. A WEAK FRONT EXPECTED SATURDAY WILL PROBABLY ADD TO
DAYTIME TEMPERATURES THROUGH REDUCED CLOUDINESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 80 66 82 69 86 / 10 10 30 30 20
AUSTIN BERGSTROM INTL AIRPORT 79 66 81 68 85 / 10 10 30 30 20
NEW BRAUNFELS MUNI AIRPORT 79 66 82 69 87 / 10 20 30 30 20
BURNET MUNI AIRPORT 77 66 81 68 85 / 10 20 30 30 20
DEL RIO INTL AIRPORT 81 67 86 70 88 / 10 20 20 10 20
GEORGETOWN MUNI AIRPORT 79 67 82 68 86 / 10 10 30 30 20
HONDO MUNI AIRPORT 80 67 82 69 87 / 10 20 30 20 20
SAN MARCOS MUNI AIRPORT 78 66 81 68 85 / 10 20 30 30 20
LA GRANGE - FAYETTE REGIONAL 79 66 82 70 85 / 10 10 30 30 20
SAN ANTONIO INTL AIRPORT 79 68 82 71 86 / 10 20 30 20 20
STINSON MUNI AIRPORT 81 68 82 71 87 / 10 20 30 20 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...01
SYNOPTIC/GRIDS...04
PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
652 AM CDT TUE APR 21 2015
.AVIATION...
/12Z TAFS/
CLEAR SKIES ARE IN PLACE AS UPPER LEVEL MOISTURE PUSHES TO THE
EAST AND LIGHT WINDS FROM THE NORTHWEST AND NORTHEAST DOMINATE AT
THE SURFACE. HOWEVER...THIS CONDITION IS FORECAST TO QUICKLY
CHANGE THIS MORNING AS SOUTHERLY WINDS RETURN. MVFR CONDITIONS ARE
EXPECTED ACROSS KSAT AND KSSF AROUND 14Z TO 16Z AS A POCKET OF LOW
CLOUDS FORM ACROSS THE SAN ANTONIO METRO AREA. CLOUDS WILL
INCREASE THROUGHOUT THE DAY AS GULF MOISTURE PUSHES NORTHWARD FOR
THE RETURN OF MVFR CONDITIONS ACROSS AREA SITES THIS EVENING. AREA
SOUNDINGS AND MOS GUIDANCE ARE SUGGESTING CIGS TO LOWER TO
IFR/LIFR OVERNIGHT AS SATURATED AIR DOMINATES THE AREA. WINDS WILL
BE FROM THE SOUTHEAST FOR THE MOST PARTS WITH SPEEDS OF 10 KNOTS
AND GUSTING UP TO 21 KNOTS ACROSS KDRT THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 442 AM CDT TUE APR 21 2015/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
A WEAK UPPER LEVEL DISTURBANCE MOVED OVER THE AREA OVERNIGHT AND
CLEARING SKIES ARE LEFT IN ITS WAKE. THE CLEARING SHOULD BE
TEMPORARY AS A MOIST LAYER AT 850 HPA SHOULD SATURATE IN MANY
AREAS. THE CLOUDS WILL PROBABLY BE SCT VARIABLE TO BKN SINCE THE
MOISTURE LAYER APPEARS THIN. THUS WILL GO WITH SLIGHTLY ABOVE
BLENDED GUIDANCE HIGHS TODAY. RAP SOUNDINGS SUGGEST A BREAKABLE
CAP SHOULD THERE BE ENOUGH MOISTURE SO WILL CONTINUE WITH ISOLATED
POPS. AN UPPER LOW CURRENTLY OVER SOUTHERN CA WILL CONTINUE TO
CARVE DEEPER OVER THE BAJA PENINSULA THROUGH WEDNESDAY. DEEPENING
MOISTURE WILL LEAD TO INCREASED RAIN CHANCES AND A FEW STRONG
STORMS AND POSSIBLE SUPERCELLS AS NOTED IN THE SPC DAY 2 OUTLOOK.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
A FAIRLY LIGHT LOW LEVEL FLOW WEDNESDAY NIGHT INTO THURSDAY MEANS
THAT THERE COULD BE SOME REMNANT OUTFLOW BOUNDARIES LEFT FROM
WEDNESDAY STORMS TO BRING ADDITIONAL STORM FOCUS FOR THURSDAY AS
THE UPPER LOW BEGINS TO LIFT INTO THE SOUTHERN ROCKIES. HIGHEST
POPS OF THE WEEK ARE THUS SAVED FOR THURSDAY NIGHT INTO FRIDAY.
THE EJECTION OF THE LOW INTO A SHALLOW TROUGH LEAVES SOME COVERAGE
UNCERTAINTIES THIS FAR SOUTH...SO DO NOT WANT TO OVER-ADVERTISE
THE SEVERE THREAT BEYOND A NOD IN THE HWO. POPS SHOULD LOWER
SATURDAY INTO SUNDAY AS FLAT RIDGING ALOFT RETURNS. MOISTURE IS
SUFFICIENT FOR STORMS...BUT EXPECT A STRONGER CAPPING INVERSION.
ANOTHER LOW LATITUDE UPPER DISTURBANCE IS FORECAST BY THE GFS TO
BRING RAIN AND STORMS BY MIDWEEK...BUT WILL KEEP WITH THE MORE
CONSERVATIVE ECMWF UNTIL THE PATTERN DIFFERENCES BETWEEN MODELS
DECREASE. TEMPERATURES THROUGH THE PERIOD SHOULD CONTINUE TO BE
SEASONAL. A WEAK FRONT EXPECTED SATURDAY WILL PROBABLY ADD TO
DAYTIME TEMPERATURES THROUGH REDUCED CLOUDINESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 80 66 82 69 86 / 20 10 30 30 20
AUSTIN BERGSTROM INTL AIRPORT 79 66 81 68 85 / 20 10 30 30 20
NEW BRAUNFELS MUNI AIRPORT 79 66 82 69 87 / 20 20 30 30 20
BURNET MUNI AIRPORT 77 66 81 68 85 / 20 20 30 30 20
DEL RIO INTL AIRPORT 81 67 86 70 88 / 20 20 20 10 20
GEORGETOWN MUNI AIRPORT 79 67 82 68 86 / 20 10 30 30 20
HONDO MUNI AIRPORT 82 67 82 69 87 / 20 20 30 20 20
SAN MARCOS MUNI AIRPORT 78 66 81 68 85 / 20 20 30 30 20
LA GRANGE - FAYETTE REGIONAL 79 66 82 70 85 / 20 10 30 30 20
SAN ANTONIO INTL AIRPORT 80 68 82 71 86 / 20 20 30 20 20
STINSON MUNI AIRPORT 81 68 82 71 87 / 20 20 30 20 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...18
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
442 AM CDT TUE APR 21 2015
.SHORT TERM (TODAY THROUGH WEDNESDAY)...
A WEAK UPPER LEVEL DISTURBANCE MOVED OVER THE AREA OVERNIGHT AND
CLEARING SKIES ARE LEFT IN ITS WAKE. THE CLEARING SHOULD BE
TEMPORARY AS A MOIST LAYER AT 850 HPA SHOULD SATURATE IN MANY
AREAS. THE CLOUDS WILL PROBABLY BE SCT VARIABLE TO BKN SINCE THE
MOISTURE LAYER APPEARS THIN. THUS WILL GO WITH SLIGHTLY ABOVE
BLENDED GUIDANCE HIGHS TODAY. RAP SOUNDINGS SUGGEST A BREAKABLE
CAP SHOULD THERE BE ENOUGH MOISTURE SO WILL CONTINUE WITH ISOLATED
POPS. AN UPPER LOW CURRENTLY OVER SOUTHERN CA WILL CONTINUE TO
CARVE DEEPER OVER THE BAJA PENINSULA THROUGH WEDNESDAY. DEEPENING
MOISTURE WILL LEAD TO INCREASED RAIN CHANCES AND A FEW STRONG
STORMS AND POSSIBLE SUPERCELLS AS NOTED IN THE SPC DAY 2 OUTLOOK.
&&
.LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
A FAIRLY LIGHT LOW LEVEL FLOW WEDNESDAY NIGHT INTO THURSDAY MEANS
THAT THERE COULD BE SOME REMNANT OUTFLOW BOUNDARIES LEFT FROM
WEDNESDAY STORMS TO BRING ADDITIONAL STORM FOCUS FOR THURSDAY AS
THE UPPER LOW BEGINS TO LIFT INTO THE SOUTHERN ROCKIES. HIGHEST
POPS OF THE WEEK ARE THUS SAVED FOR THURSDAY NIGHT INTO FRIDAY.
THE EJECTION OF THE LOW INTO A SHALLOW TROUGH LEAVES SOME COVERAGE
UNCERTAINTIES THIS FAR SOUTH...SO DO NOT WANT TO OVER-ADVERTISE
THE SEVERE THREAT BEYOND A NOD IN THE HWO. POPS SHOULD LOWER
SATURDAY INTO SUNDAY AS FLAT RIDGING ALOFT RETURNS. MOISTURE IS
SUFFICIENT FOR STORMS...BUT EXPECT A STRONGER CAPPING INVERSION.
ANOTHER LOW LATITUDE UPPER DISTURBANCE IS FORECAST BY THE GFS TO
BRING RAIN AND STORMS BY MIDWEEK...BUT WILL KEEP WITH THE MORE
CONSERVATIVE ECMWF UNTIL THE PATTERN DIFFERENCES BETWEEN MODELS
DECREASE. TEMPERATURES THROUGH THE PERIOD SHOULD CONTINUE TO BE
SEASONAL. A WEAK FRONT EXPECTED SATURDAY WILL PROBABLY ADD TO
DAYTIME TEMPERATURES THROUGH REDUCED CLOUDINESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 80 66 82 69 86 / 20 10 30 30 20
AUSTIN BERGSTROM INTL AIRPORT 79 66 81 68 85 / 20 10 30 30 20
NEW BRAUNFELS MUNI AIRPORT 79 66 82 69 87 / 20 20 30 30 20
BURNET MUNI AIRPORT 77 66 81 68 85 / 20 20 30 30 20
DEL RIO INTL AIRPORT 81 67 86 70 88 / 20 20 20 10 20
GEORGETOWN MUNI AIRPORT 79 67 82 68 86 / 20 10 30 30 20
HONDO MUNI AIRPORT 82 67 82 69 87 / 20 20 30 20 20
SAN MARCOS MUNI AIRPORT 78 66 81 68 85 / 20 20 30 30 20
LA GRANGE - FAYETTE REGIONAL 79 66 82 70 85 / 20 10 30 30 20
SAN ANTONIO INTL AIRPORT 80 68 82 71 86 / 20 20 30 20 20
STINSON MUNI AIRPORT 81 68 82 71 87 / 20 20 30 20 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...18
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
410 AM EDT TUE APR 21 2015
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO MOVE EAST THROUGH VIRGINIA AND WILL
REACH THE COAST THIS MORNING. HIGH PRESSURE OVER THE SOUTHERN
PLAINS WILL MOVE EAST TO THE COAST BY WEDNESDAY MORNING. ANOTHER
FRONT WILL MOVE THROUGH THE AREA ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM EDT TUESDAY...
LOCAL NATIONAL WEATHER SERVICE RADAR SHOWED WIDELY SCATTERED
SHOWERS IN THE MOUNTAINS EARLY THIS MORNING. EVEN THOUGH UPSLOPE
FLOW CONTINUES THROUGH THE DAY...HAVE ENDED THE SHOWERS AFTER
THIS MORNING AND EXPECT A CLEARING SKY THIS AFTERNOON AS THE AIR
MASS DRIES OUT. HRRR SUGGESTS SHOWERS MAY BE GONE AS EARLY AT 7AM.
SURFACE DEW POINTS ALREADY DROPPING INTO THE 30S AND
40S BEHIND THE COLD FRONT THAT EXTENDED FROM EASTERN PENNSYLVANIA
TO THE FLORIDA PANHANDLE. DRIER AIR ALOFT MAY BE SEEN ON THE WATER
VAPOR LOOP ADVANCING ACROSS THE CENTRAL AND SOUTHERN APPALACHIANS.
THE DOWNSLOPE WINDS WILL AIDE IN DRYING AND WARMING THE AIR EAST
OF THE BLUE RIDGE. EXPECT HIGHS IN THE EAST TO BE ON THE WARMER
SIDE OF GUIDANCE. BUFKIT FORECAST SOUNDINGS SHOWED DEEP MIXING
WHICH WILL AIDE IN TRANSPORTING DRIER AIR DOWN TO THE SURFACE.
THE DEEP MIXING AND PRESSURE RISES OF 3 TO 6 MB IN 6 HOURS WILL
RESULT IN GUSTS AS HIGH AS 35 MPH.
WINDS WILL DIMINISH TONIGHT AFTER SUNSET. LATER TONIGHT CLOUDS
INCREASE AHEAD OF AN APPROACHING COLD FRONT. MODELS HOLD THE
POTENTIAL FOR PRECIPITATION WEST OF THE FORECAST AREA UNTIL AFTER
07Z/3AM. LOW LEVEL JET FROM THE SOUTH-SOUTHWEST ALSO INCREASES TO
NEARLY 45 KNOTS BY LATE TONIGHT. HAVE STRONG GUSTS...BUT STILL
UNDER ADVISORY CRITERIA...AT HIGHER ELEVATIONS AFTER MIDNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 330 AM EDT TUESDAY...
THE CLOSED UPPER LOW WILL CONTINUE TO DO A SIT AND SPIN OVER THE GREAT
LAKES REGION THROUGH THE SHORT TERM PERIOD....KEEPING OUR TEMPERATURES
AT OR SLIGHTLY BELOW NORMAL. BY WEDNESDAY MORNING A SPOKE OF ENERGY
ROTATING AROUND THE UPPER LOW WILL BE PUSHING A COLD FRONT INTO THE
AREA FROM THE WEST. MOISTURE/INSTABILITY ARE LIMITED BUT LAPSE RATES
ARE STEEP SO SOME SHOWERS AND THUNDERSTORMS WILL BE ABLE TO DEVELOP
AHEAD OF THE FRONT. THE BIG FEATURE OF NOTE WILL BE THE SYNOPTIC WINDS.
THE LOW LEVEL WIND FIELD WILL BE RAMPING UP TO 40KTS/50KTS AND MODEL
SOUNDINGS SHOW A VERY WELL MIXED AND DRY BOUNDARY LAYER THAT WILL BE
EFFICIENT FOR DOWNWARD MOMENTUM TRANSFER...ESPECIALLY AS COLDER AIR
STARTS TO WORK IN BEHIND THE FRONT. BELIEVE THE SITUATION WILL REMAIN
BELOW ADVISORY CRITERIA BUT THE RIDGES MAY SEE GUSTS AROUND 40MPH. ANY
SHOWERS/STORMS WILL ALSO HAVE PLENTY OF WIND TO MIX DOWN SO EVEN
UNIMPRESSIVE CONVECTIVE CLUSTERS MAY BE QUITE GUSTY.
BEHIND THE FRONT WE SHOULD GET ENOUGH HIGH PRESSURE BUILDING IN FROM
THE NORTHWEST TO KEEP THINGS QUIET...THOUGH BREEZY...THROUGH THE END OF
THE WORKWEEK. TEMPERATURES HAVE BEEN TRENDING COLDER FOR BOTH MAX/MIN
TEMPS THURSDAY AND FRIDAY...SO WILL BE SHADING GRIDS IN THAT DIRECTION.
SOME OF THE HIGHER TERRAIN WEST OF THE BLUE RIDGE WILL BE FLIRTING WITH
TEMPERATURES APPROACHING THE FREEZING MARK BOTH MORNINGS. HOWEVER...THE
AG PROGRAM WILL NOT BE IN FULL SWING WEST OF THE RIDGE UNTIL MAY 1 SO
THIS IS NOT LIKELY TO CAUSE ANY SIGNIFICANT PROBLEMS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
AS OF 130 PM EDT MONDAY...
NOT MUCH CHANGE TO THIS FORECAST. 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 /08Z TUESDAY THROUGH SATURDAY/...
AS OF 145 AM EDT TUESDAY...
COLD FRONT WAS EAST OF THE BLUE RIDGE EARLY THIS MORNING AND WAS
CLOSE TO CROSSING THROUGH KLYH AND KDAN AT 06Z/2AM. HAVE THE FRONT
PASSING THROUGH THESE STATIONS AND WINDS BECOMING WEST BY 08Z/4AM.
PRESSURE RISES BEHIND THE FRONT WILL BRING WIND GUSTS OF 20 TO 30
KNOTS THROUGH MID TO LATE AFTERNOON. AFTER SUNSET WINDS WILL
DIMINISH TO LESS THAN 10 KTS.
CURRENTLY SOME MVFR CEILINGS IN THE MOUNTAINS AND RAPIDLY
DISSIPATING SHOWERS. LOWER CONFIDENCE ABOUT HOW WIDESPREAD MVFR
CEILINGS WILL BE BEFORE 12Z/8AM. VFR CONDITIONS WILL RETURN THIS
AFTERNOON WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT.
EXTENDED AVIATION...
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY WITH THE PASSAGE OF A
COLD FRONT.
HIGH PRESSURE AT THE SURFACE BUILDS SOUTHEAST FROM THE OHIO
VALLEY THURSDAY NIGHT INTO FRIDAY. OVERRUNNING CLOUDS WORK INTO
THE AREA FRIDAY AHEAD OF A WARM FRONT. BY SATURDAY...ENOUGH
MOISTURE TO ALLOW FOR SHOWERS WITH BEST FORCING ACROSS THE
CAROLINAS.
&&
.HYDROLOGY...
AS OF 405 AM EDT TUESDAY...
AFTER THE IMPRESSIVE RAINFALL SINCE SUNDAY MORNING...WHICH SAW
OVER 6 INCHES AT A FEW GAGES IN ALLEGHANY COUNTY NC...RIVERS AND
LARGE CREEKS IN THE NEW RIVER AND UPPER ROANOKE VALLEYS HAVE
MOSTLY CRESTED AND ARE FALLING.
STAGES ALONG THE MAINSTEM NEW RIVER WILL CONTINUE TO FALL.
ALLISONIA AND RADFORD HAVE RECEDED BACK BELOW FLOOD STAGE.
RIVER FLOOD WARNINGS CONTINUE FOR THE LOWER ROANOKE RIVER AT
RANDOLPH AND AT DANVILLE AND SOUTH BOSTON ON THE DAN FOR MINOR
FLOODING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...MBS
LONG TERM...WP
AVIATION...AMS/JH
HYDROLOGY...AMS/PC
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1041 PM CDT WED APR 22 2015
.UPDATE...
&&
.AVIATION/06Z TAFS/...
VFR CONDITIONS EXPECTED. THE RAP AND NEW NAM SHOW THE LOW LEVELS
DRYING OUT FROM THE DELLS TO MADISON TO JANESVILLE AND WEST. WHILE
NOT SATURATED...THE LOW LEVELS REMAIN MORE MOIST NORTH TOWARD
SHEBOYGAN. EVEN THERE THE MOIST LAYER IS RATHER SHALLOW SO STILL
EXPECT MAINLY SCATTERED CUMULUS THERE ON THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 248 PM CDT WED APR 22 2015/
SHORT TERM...TONIGHT THROUGH SATURDAY
TONIGHT AND THURSDAY...FORECAST CONFIDENCE HIGH.
LOOK FOR VERY ISOLATED CHANCES OF RAIN AND SNOW SHOWERS TO CONTINUE
THIS AFTERNOON INTO THE EARLY EVENING BUT WILL FINALLY BEGIN TO
BREAK TONIGHT AS AN EXTENSIVE SFC LOW PRESSURE SYSTEM WILL MOVE OFF
TO THE EAST. A 500 MB SHORTWAVE TROUGH WITH ASSOCIATED SHEARED
POSITIVE VORTICITY ADVECTION WILL PERSIST OVER THE REGION THROUGH
THURSDAY AFTERNOON...BUT CONDITIONS LOOK TO BE CLEAR AS THE
ENVIRONMENTAL PROFILES FROM NAM AND RAP BUFKIT SOUNDINGS LOOK TO DRY
OUT OVERNIGHT. GUSTY NORTHWEST WINDS WILL CONTINUE TONIGHT...BUT
WILL WEAKEN AS SFC PRESSURE GRADIENT WEAKENS.
THURSDAY LOOKS LIKE A QUIETER DAY AS SFC HIGH PRESSURE MOVES INTO
THE REGION FROM THE NORTHWEST. MID-LEVEL HEIGHTS WILL RISE AS THE
HIGH PRESSURE APPROACHES. THE CAVEAT THURSDAY WILL BE CONTINUED COLD
TEMPERATURES AS WE REMAIN IN A NORTHWEST FLOW REGIME. 925 MB
TEMPERATURES WILL ONCE AGAIN BE IN THE SINGLE NEGATIVE DIGITS...WITH
LOWS DROPPING INTO THE UPPER 20S ACROSS SOUTHERN WISCONSIN. THE GOOD
NEWS IS SKIES WILL CLEAR THURSDAY AS A DRIER AIRMASS MOVES IN.
ABUNDANT SUNSHINE WILL HELP INCREASE OUR TEMPERATURES BACK INTO THE
LOWER 50S.
THURSDAY NIGHT THROUGH SATURDAY...FORECAST CONFIDENCE MEDIUM.
QUIET CONDITIONS CONTINUE FOR THURSDAY NIGHT AND FRIDAY AS SFC
RIDGING TAKES HOLD. GOOD RADIATIONAL COOLING THURSDAY NIGHT WILL
ALLOW NEAR TO BELOW FREEZING LOW TEMPERATURES AWAY FROM THE
LAKESHORE. RIDGE SHIFTS EAST OF THE REGION FRIDAY NIGHT AS A
SHORTWAVE IMPULSE EJECTS FROM THE CENTRAL PLAINS INTO IOWA AND
MISSOURI. ASSOCIATED SFC LOW TRACKS FROM NEBRASKA INTO MISSOURI
SATURDAY MORNING...WITH PCPN SHIELD BRUSHING SOUTHERN WISCONSIN
FRIDAY EVENING. BEST OMEGA AND LAYER Q-VECTOR CONVERGENCE ARRIVES
FRIDAY NIGHT AND LASTS THROUGH EARLY SATURDAY. KEPT CHANCE POPS IN
PLACE DURING THIS TIME. TEMPS IN THE NORTHERN CWA WILL BE NEAR
FREEZING FRIDAY NIGHT...WITH A RAIN-SNOW MIX POSSIBLE. WARM
ADVECTION SHOULD KICK IN SATURDAY MORNING...WITH PCPN
TRANSITIONING TO ALL RAIN. ANY LINGERING SHOWERS SHOULD COME TO AN
END SATURDAY NIGHT. HIGHS WARM INTO THE 50S AWAY FROM THE LAKE ON
FRIDAY...BEFORE TURNING COOLER ON SATURDAY.
LONG TERM...SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE
MEDIUM.
DECENT MODEL AGREEMENT ON SFC RIDGING TAKING HOLD ACROSS THE
EASTERN GREAT LAKES REGION ON SUNDAY AND MONDAY. TEMPERATURES
MODERATE A BIT FROM SATURDAY...WITH HIGHS IN THE 50S LOWER 60S.
THEREAFTER...12Z GFS/00Z ECMWF RUNS ARE TAKING A MORE SOUTHERLY
TRACK WITH A LOW PRESSURE SYSTEM INITIALLY OVER THE TX PANHANDLE
ON MONDAY. WHILE PREVIOUS GFS RUN LIFTED IT WELL INTO
MISSOURI...CONSENSUS TRACK IS NOW INTO THE LOWER MISSISSIPPI
VALLEY. IN LIGHT OF THIS...AND PER COORDINATION WITH SURROUNDING
WFOS...REMOVED POPS FOR MONDAY AND EARLY TUESDAY. KEPT CHANCE
POPS FOR TUESDAY AFTERNOON INTO WEDNESDAY WITH ECMWF SHOWING
BETTER SHORTWAVE ENERGY AND GENERATING SOME LIGHT PCPN.
AVIATION/00Z TAFS/...LOW END VFR CIGS WILL CONTINUE INTO THE EARLY
EVENING AS A PERSISTENT STRATOCUMULUS DECK WILL STICK AROUND THE
AREA. THE RAP AND NAM BUFKIT SOUNDINGS SHOW THE ATMOSPHERIC PROFILE
DRYING OUT LATER THIS EVENING...IMPROVING CIG HEIGHTS. VERY ISOLATED
RAIN AND SNOW SHOWERS ARE POSSIBLE THIS AFTERNOON AND EARLY EVENING
UNTIL A DRIER AIRMASS MOVES IN DURING THE OVERNIGHT HOURS. NORTHWEST
WINDS WILL REMAIN GUSTY INTO THE EARLY EVENING HOURS...WITH GUSTS
NEAR 25 KTS POSSIBLE. WINDS WILL WEAKEN AFTER 00Z THURSDAY.
MARINE...A SMALL CRAFT ADVISORY IS IN EFFECT UNTIL 00Z THURSDAY.
NORTHWEST WINDS WILL REMAIN GUSTY INTO THE EARLY EVENING
HOURS...WITH GUSTS NEAR 25 KTS POSSIBLE. WINDS SHOULD WEAKEN AFTER
00Z AS SFC PRESSURE GRADIENT WEAKENS. WAVES WILL BE 1-2 FT UNTIL
THE WINDS WEAKEN.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...HENTZ
TONIGHT/THURSDAY AND AVIATION/MARINE...JTS
THURSDAY NIGHT THROUGH WEDNESDAY...SPM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
706 PM CDT WED APR 22 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 243 PM CDT WED APR 22 2015
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER TROUGHS OVER BRITISH COLUMBIA...ALONG THE SOUTHERN
CALIFORNIA COAST...AND OVER THE FORECAST AREA INTO THE GREAT
LAKES...WHILE RIDGING EXTENDED FROM THE FOUR CORNERS OF THE U.S.
INTO ALBERTA. CYCLONIC FLOW OF MOISTURE AROUND THE GREAT LAKES UPPER
TROUGH...NICELY SEEN ON THE 12Z GRB SOUNDING...HELPING TO HOLD
STRATOCUMULUS ACROSS WI. GO A LITTLE MORE TO THE WEST OVER MN AND
IA...MUCH DRIER AIR WAS PRESENT ON THE 12Z MPX SOUNDING WITH A
PRECIPITABLE WATER OF 0.16 INCHES OR 36 PERCENT OF NORMAL. THIS
DRIER AIR HAS RESULTED IN CLEARER SKIES. A RIDGE OF HIGH PRESSURE
ACCOMPANYING THE CLEAR SKIES WAS LOCATED OVER THE EASTERN DAKOTAS. A
TIGHT PRESSURE GRADIENT EAST OF THIS RIDGE MAINTAINING A BRISK
NORTHWEST BREEZE OVER THE FORECAST AREA WITH SPEEDS/GUSTS A LITTLE
LOWER THAN 24 HRS AGO. STILL...THE SPEEDS HAVE BEEN STRONG ENOUGH TO
WARRANT THE EARLIER ISSUED WIND ADVISORY FOR A SMALL PORTION OF
NORTHEAST IOWA. AIRMASS REMAINS UNSEASONABLY COOL WITH 850MB TEMPS
IN THE -5 TO -8C RANGE...RESULTING IN THE PRESENT 40S
TEMPERATURES...AND EVEN 30S AT MEDFORD WI.
THE UPPER TROUGH AFFECTING THE FORECAST AREA INTO THE GREAT LAKES IS
PROGGED TO MAKE MUCH MORE EASTWARD PROGRESS OVER THE NEXT 24
HOURS...REACHING NEW ENGLAND BY 00Z FRI. THIS WILL ALLOW THE RIDGING
AND WARMER/DRIER AIR OVER THE NORTHERN ROCKIES AND PLAINS TO MARCH
TOWARDS THE FORECAST AREA. WE DO HAVE ONE SHORTWAVE TO CONTEND WITH
COMING DOWN THE BACK SIDE OF THE UPPER TROUGH TONIGHT...WHICH ITS
MAIN IMPACT IS TO BRING IN SLIGHTLY COOLER AIR FOR 12Z THU BEFORE
THE WARMING COMMENCES.
CLOUDS MAY BE A BIT PERSISTENT NORTHEAST OF I-94 TONIGHT...THANKS TO
THAT SHORTWAVE COMING THROUGH...BUT ELSEWHERE ANY STRATOCUMULUS WILL
DISSIPATE WITH LOSS OF DAYTIME HEATING. THIS CLEARING COMBINED WITH
WINDS DIMINISHING SOME AS THE RIDGE APPROACHES I-35 BY 12Z THU IS
EXPECTED TO RESULT IN A CHILLY NIGHT. 20S SHOULD BE COMMON ACROSS
MUCH OF THE REGION BY SUNRISE WITH PERHAPS NEAR 30 READINGS IN THE
MS RIVER VALLEY. NO FROST/FREEZE HEADLINES WILL BE POSTED YET AS
VEGETATION GROWTH IS NOT QUITE THERE. 850MB TEMPS ON THU CLIMB TO 0
TO -2C BY 00Z FRI WHICH WITH PLENTY OF SUN SHOULD BE ABLE TO BOOST
TEMPERATURES INTO THE LOW TO MID 50S FOR MOST LOCATIONS. MEDFORD
AGAIN MIGHT BE THE LONE COOLER EXCEPTION BEING CLOSER TO THE
DEPARTING COLD AIR. DEEP MIXING IS LIKELY AS WELL IN THE DRY AIRMASS
FEATURING PRECIPITABLE WATER NEAR 0.10 INCHES...CAUSING LOW RELATIVE
HUMIDITY VALUES. THE COMBINATION OF THESE LOW VALUES AND A 10 TO 15
MPH NORTHWEST BREEZE COULD RESULT IN SOME FIRE WEATHER CONCERN. SEE
FIRE WEATHER SECTION BELOW FOR MORE DETAILS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 243 PM CDT WED APR 22 2015
FIRST FOCUS OF THE LONG TERM PERIOD IS ON THE UPPER TROUGH NEAR THE
SOUTHERN CALIFORNIA COAST. MODELS ARE IN GOOD AGREEMENT LIFTING THIS
TROUGH INTO THE CENTRAL PLAINS ON FRIDAY AND INTO CENTRAL ILLINOIS
ON SATURDAY. ALTHOUGH THIS TRACK IS SOUTH OF THE FORECAST AREA...WE
STILL HAVE SOME SHOT AT PRECIPITATION DURING THE FRIDAY-SATURDAY
TIME FRAME. PART OF THIS IS DUE TO A SOMEWHAT DECENT MOISTURE SURGE
AHEAD OF THE TROUGH UP INTO THE FORECAST AREA ON FRIDAY...REFLECTED
BY PRECIPITABLE WATER CLIMBING TO AROUND 0.75 INCHES BY 00Z SAT.
ADDITIONALLY...A SHORTWAVE IS PROGGED TO EJECT OUT OF THE TROUGH AND
MOVE THROUGH THE AREA ON FRIDAY...INTERACTING WITH THE MOISTURE.
THEREFORE...CHANCES OF PRECIPITATION PERSIST FOR FRIDAY...ESPECIALLY
IN THE AFTERNOON AND INTO THE NIGHT WEST OF THE MS RIVER WHERE MORE
MOISTURE EXISTS. PRECIPITATION SHOULD BEGIN TO WANE NORTH TO SOUTH
ON SATURDAY AS THE UPPER TROUGH MOVES EAST OF OUR LONGITUDE...
CUTTING OFF THE MOISTURE TRANSPORT AND ALLOWING DRIER AIR TO GET
DRAWN IN FROM THE NORTH AND EAST. SOME MODEL DIFFERENCES EXIST ON
HOW MUCH PRECIPITATION EXISTS ON SATURDAY DUE TO SLIGHT NORTH/SOUTH
DIFFERENCES OF THE UPPER TROUGH TRACK...WITH THE 22.12Z GFS/CANADIAN
FARTHEST NORTH UP TO US-10 AND 22.12Z NAM/ECMWF FARTHEST SOUTH TO
AROUND US-20. THEREFORE...PRECIPITATION CHANCES ON SATURDAY REMAIN
AT OR BELOW 50 PERCENT. BETWEEN THE CLOUDS AND PRECIPITATION...HIGH
TEMPERATURES LOOK TO BE A LITTLE COOLER THAN ON THU.
A DRIER AND WARMER PERIOD IS ON TAP FOR SUNDAY AS AN UPPER RIDGE
AXIS APPROACHES THE FORECAST AREA FROM THE WEST. WITH 850MB TEMPS OF
0-2C...SHOULD SEE HIGHS CLIMB WELL UP INTO THE 50S AND POSSIBLY 60S
IN RIVER VALLEYS. EASTERLY FLOW FROM HIGH PRESSURE OVER ONTARIO
LIKELY TO CAUSE RELATIVE HUMIDITIES TO TANK.
MODELS HAVE CHANGED THEIR TUNE A BIT FOR SUNDAY NIGHT THROUGH MONDAY
NIGHT...LEANING TOWARDS DRIER AND WARMER. THIS IS A RESULT OF A
SHORTWAVE TROUGH COMING INTO THE PACIFIC NORTHWEST ON SATURDAY
THAT...INSTEAD OF HEADING TOWARDS THE FORECAST AREA...NOW DIGS DOWN
INTO THE SOUTHERN PLAINS. THEREFORE HAVE FOLLOWED SUIT...DRYING OUT
THE FORECAST AND RAISING TEMPERATURES.
AS WE HEAD INTO TUESDAY AND WEDNESDAY...UPPER RIDGING IS PROGGED TO
DEVELOP OVER THE WESTERN U.S. INTO WESTERN CANADA...CAUSING
SHORTWAVES TO DROP INTO THE REGION ON NORTHERLY FLOW. AS A
RESULT...SOME LOW PRECIPITATION CHANCES ARE IN THE FORECAST. HARD TO
SAY HOW MUCH PRECIPITATION WILL FALL GIVEN LACK OF MOISTURE
AVAILABILITY. DESPITE THE NORTHERLY FLOW...850MB TEMPS ARE STILL
PROGGED IN THE 2-4C RANGE SO TEMPERATURES DO NOT LOOKS TO CHANGE
MUCH FROM MONDAY AND STAY JUST BELOW SEASONABLE NORMALS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 629 PM CDT WED APR 22 2015
A TROUGH OVER NORTHERN WISCONSIN WILL MOVE SOUTHEAST ACROSS
WISCOSNIN TONIGHT. THIS SYSTEM WILL KEEP A 4-8K BROKEN DECK OF
CLOUDS JUST TO THE EAST OF KLSE THROUGH THURSDAY MORNING...AND
THEN THESE CLOUDS WILL MOVE EAST INTO MICHIGAN. WITH THIS IN
MIND KEPT SKC GOING FOR MUCH OF THIS TAF PERIOD...BUT WE WILL HAVE
TO WATCH LA CROSSE CLOSELY.
WITH THE LOSS OF DIURNAL HEATING THIS EVENING...THE WIND GUSTS
WILL QUICKLY DIMINISH AROUND 23.01Z AND WILL NOT REDEVELOP ON
THURSDAY. AFTER THE WIND GUSTS DIE DOWN...SUSTAINED WINDS WILL BE
OUT OF THE NORTHWEST AROUND 10 KNOTS.
&&
.FIRE WEATHER...
ISSUED AT 243 PM CDT WED APR 22 2015
TODAY HAS BEEN MOSTLY A DRYING DAY WEST OF THE MISSISSIPPI RIVER
WHERE MORE SUN HAS OCCURRED...CLOSER TO THE DRIER AIR OVER WESTERN
MN AND WINDS HAVE BEEN GUSTING 30-40 MPH. A WARMER DAY IS EXPECTED
ACROSS THE REGION ON THURSDAY WITH SUNNY SKIES. ADDITIONALLY...THE
DRY AIR OVER WESTERN MN MOVES IN...PLUMMETING RH VALUES TO 20-30
PERCENT. HOWEVER...WINDS DO NOT LOOK NEARLY AS STRONG WITH HIGH
PRESSURE MOVING IN...ONLY IN THE 10 TO 15 MPH RANGE. WITH SOME
GREEN-UP ALREADY OCCURRING AND THE LIGHTER WINDS...HAVE DECLINED
TO CONSIDER ANY FIRE WEATHER HAZARDS AT THIS TIME. SOME RAIN
REMAINS ON TAP TO MOVE INTO THE REGION FOR FRIDAY...ALONG WITH
CLOUDS...WHICH BOTH SHOULD HELP MITIGATE FIRE WEATHER CONCERNS.
LOOKING AHEAD...SUNDAY COULD BE ANOTHER DAY WORTH WATCH FOR FIRE
WEATHER CONCERNS...BUT SIMILAR TO THURSDAY WINDS ARE EXPECTED ON
THE LIGHTER SIDE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
630 PM CDT WED APR 22 2015
.UPDATE...THIS EVENING
ISSUED AT 629 PM CDT WED APR 22 2015
SOUNDINGS CONTINUE TO SHOW THAT THE WIND GUSTS WILL RAPIDLY
DIMINISH BETWEEN 23.00Z AND 23.01Z. DUE TO THIS...PLAN ON JUST
ALLOWING THE WIND ADVISORY FOR PARTS OF NORTHEAST IOWA TO EXPIRE
ON TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 243 PM CDT WED APR 22 2015
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER TROUGHS OVER BRITISH COLUMBIA...ALONG THE SOUTHERN
CALIFORNIA COAST...AND OVER THE FORECAST AREA INTO THE GREAT
LAKES...WHILE RIDGING EXTENDED FROM THE FOUR CORNERS OF THE U.S.
INTO ALBERTA. CYCLONIC FLOW OF MOISTURE AROUND THE GREAT LAKES UPPER
TROUGH...NICELY SEEN ON THE 12Z GRB SOUNDING...HELPING TO HOLD
STRATOCUMULUS ACROSS WI. GO A LITTLE MORE TO THE WEST OVER MN AND
IA...MUCH DRIER AIR WAS PRESENT ON THE 12Z MPX SOUNDING WITH A
PRECIPITABLE WATER OF 0.16 INCHES OR 36 PERCENT OF NORMAL. THIS
DRIER AIR HAS RESULTED IN CLEARER SKIES. A RIDGE OF HIGH PRESSURE
ACCOMPANYING THE CLEAR SKIES WAS LOCATED OVER THE EASTERN DAKOTAS. A
TIGHT PRESSURE GRADIENT EAST OF THIS RIDGE MAINTAINING A BRISK
NORTHWEST BREEZE OVER THE FORECAST AREA WITH SPEEDS/GUSTS A LITTLE
LOWER THAN 24 HRS AGO. STILL...THE SPEEDS HAVE BEEN STRONG ENOUGH TO
WARRANT THE EARLIER ISSUED WIND ADVISORY FOR A SMALL PORTION OF
NORTHEAST IOWA. AIRMASS REMAINS UNSEASONABLY COOL WITH 850MB TEMPS
IN THE -5 TO -8C RANGE...RESULTING IN THE PRESENT 40S
TEMPERATURES...AND EVEN 30S AT MEDFORD WI.
THE UPPER TROUGH AFFECTING THE FORECAST AREA INTO THE GREAT LAKES IS
PROGGED TO MAKE MUCH MORE EASTWARD PROGRESS OVER THE NEXT 24
HOURS...REACHING NEW ENGLAND BY 00Z FRI. THIS WILL ALLOW THE RIDGING
AND WARMER/DRIER AIR OVER THE NORTHERN ROCKIES AND PLAINS TO MARCH
TOWARDS THE FORECAST AREA. WE DO HAVE ONE SHORTWAVE TO CONTEND WITH
COMING DOWN THE BACK SIDE OF THE UPPER TROUGH TONIGHT...WHICH ITS
MAIN IMPACT IS TO BRING IN SLIGHTLY COOLER AIR FOR 12Z THU BEFORE
THE WARMING COMMENCES.
CLOUDS MAY BE A BIT PERSISTENT NORTHEAST OF I-94 TONIGHT...THANKS TO
THAT SHORTWAVE COMING THROUGH...BUT ELSEWHERE ANY STRATOCUMULUS WILL
DISSIPATE WITH LOSS OF DAYTIME HEATING. THIS CLEARING COMBINED WITH
WINDS DIMINISHING SOME AS THE RIDGE APPROACHES I-35 BY 12Z THU IS
EXPECTED TO RESULT IN A CHILLY NIGHT. 20S SHOULD BE COMMON ACROSS
MUCH OF THE REGION BY SUNRISE WITH PERHAPS NEAR 30 READINGS IN THE
MS RIVER VALLEY. NO FROST/FREEZE HEADLINES WILL BE POSTED YET AS
VEGETATION GROWTH IS NOT QUITE THERE. 850MB TEMPS ON THU CLIMB TO 0
TO -2C BY 00Z FRI WHICH WITH PLENTY OF SUN SHOULD BE ABLE TO BOOST
TEMPERATURES INTO THE LOW TO MID 50S FOR MOST LOCATIONS. MEDFORD
AGAIN MIGHT BE THE LONE COOLER EXCEPTION BEING CLOSER TO THE
DEPARTING COLD AIR. DEEP MIXING IS LIKELY AS WELL IN THE DRY AIRMASS
FEATURING PRECIPITABLE WATER NEAR 0.10 INCHES...CAUSING LOW RELATIVE
HUMIDITY VALUES. THE COMBINATION OF THESE LOW VALUES AND A 10 TO 15
MPH NORTHWEST BREEZE COULD RESULT IN SOME FIRE WEATHER CONCERN. SEE
FIRE WEATHER SECTION BELOW FOR MORE DETAILS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 243 PM CDT WED APR 22 2015
FIRST FOCUS OF THE LONG TERM PERIOD IS ON THE UPPER TROUGH NEAR THE
SOUTHERN CALIFORNIA COAST. MODELS ARE IN GOOD AGREEMENT LIFTING THIS
TROUGH INTO THE CENTRAL PLAINS ON FRIDAY AND INTO CENTRAL ILLINOIS
ON SATURDAY. ALTHOUGH THIS TRACK IS SOUTH OF THE FORECAST AREA...WE
STILL HAVE SOME SHOT AT PRECIPITATION DURING THE FRIDAY-SATURDAY
TIME FRAME. PART OF THIS IS DUE TO A SOMEWHAT DECENT MOISTURE SURGE
AHEAD OF THE TROUGH UP INTO THE FORECAST AREA ON FRIDAY...REFLECTED
BY PRECIPITABLE WATER CLIMBING TO AROUND 0.75 INCHES BY 00Z SAT.
ADDITIONALLY...A SHORTWAVE IS PROGGED TO EJECT OUT OF THE TROUGH AND
MOVE THROUGH THE AREA ON FRIDAY...INTERACTING WITH THE MOISTURE.
THEREFORE...CHANCES OF PRECIPITATION PERSIST FOR FRIDAY...ESPECIALLY
IN THE AFTERNOON AND INTO THE NIGHT WEST OF THE MS RIVER WHERE MORE
MOISTURE EXISTS. PRECIPITATION SHOULD BEGIN TO WANE NORTH TO SOUTH
ON SATURDAY AS THE UPPER TROUGH MOVES EAST OF OUR LONGITUDE...
CUTTING OFF THE MOISTURE TRANSPORT AND ALLOWING DRIER AIR TO GET
DRAWN IN FROM THE NORTH AND EAST. SOME MODEL DIFFERENCES EXIST ON
HOW MUCH PRECIPITATION EXISTS ON SATURDAY DUE TO SLIGHT NORTH/SOUTH
DIFFERENCES OF THE UPPER TROUGH TRACK...WITH THE 22.12Z GFS/CANADIAN
FARTHEST NORTH UP TO US-10 AND 22.12Z NAM/ECMWF FARTHEST SOUTH TO
AROUND US-20. THEREFORE...PRECIPITATION CHANCES ON SATURDAY REMAIN
AT OR BELOW 50 PERCENT. BETWEEN THE CLOUDS AND PRECIPITATION...HIGH
TEMPERATURES LOOK TO BE A LITTLE COOLER THAN ON THU.
A DRIER AND WARMER PERIOD IS ON TAP FOR SUNDAY AS AN UPPER RIDGE
AXIS APPROACHES THE FORECAST AREA FROM THE WEST. WITH 850MB TEMPS OF
0-2C...SHOULD SEE HIGHS CLIMB WELL UP INTO THE 50S AND POSSIBLY 60S
IN RIVER VALLEYS. EASTERLY FLOW FROM HIGH PRESSURE OVER ONTARIO
LIKELY TO CAUSE RELATIVE HUMIDITIES TO TANK.
MODELS HAVE CHANGED THEIR TUNE A BIT FOR SUNDAY NIGHT THROUGH MONDAY
NIGHT...LEANING TOWARDS DRIER AND WARMER. THIS IS A RESULT OF A
SHORTWAVE TROUGH COMING INTO THE PACIFIC NORTHWEST ON SATURDAY
THAT...INSTEAD OF HEADING TOWARDS THE FORECAST AREA...NOW DIGS DOWN
INTO THE SOUTHERN PLAINS. THEREFORE HAVE FOLLOWED SUIT...DRYING OUT
THE FORECAST AND RAISING TEMPERATURES.
AS WE HEAD INTO TUESDAY AND WEDNESDAY...UPPER RIDGING IS PROGGED TO
DEVELOP OVER THE WESTERN U.S. INTO WESTERN CANADA...CAUSING
SHORTWAVES TO DROP INTO THE REGION ON NORTHERLY FLOW. AS A
RESULT...SOME LOW PRECIPITATION CHANCES ARE IN THE FORECAST. HARD TO
SAY HOW MUCH PRECIPITATION WILL FALL GIVEN LACK OF MOISTURE
AVAILABILITY. DESPITE THE NORTHERLY FLOW...850MB TEMPS ARE STILL
PROGGED IN THE 2-4C RANGE SO TEMPERATURES DO NOT LOOKS TO CHANGE
MUCH FROM MONDAY AND STAY JUST BELOW SEASONABLE NORMALS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 629 PM CDT WED APR 22 2015
A TROUGH OVER NORTHERN WISCONSIN WILL MOVE SOUTHEAST ACROSS
WISCOSNIN TONIGHT. THIS SYSTEM WILL KEEP A 4-8K BROKEN DECK OF
CLOUDS JUST TO THE EAST OF KLSE THROUGH THURSDAY MORNING...AND
THEN THESE CLOUDS WILL MOVE EAST INTO MICHIGAN. WITH THIS IN
MIND KEPT SKC GOING FOR MUCH OF THIS TAF PERIOD...BUT WE WILL HAVE
TO WATCH LA CROSSE CLOSELY.
WITH THE LOSS OF DIURNAL HEATING THIS EVENING...THE WIND GUSTS
WILL QUICKLY DIMINISH AROUND 23.01Z AND WILL NOT REDEVELOP ON
THURSDAY. AFTER THE WIND GUSTS DIE DOWN...SUSTAINED WINDS WILL BE
OUT OF THE NORTHWEST AROUND 10 KNOTS.
&&
.FIRE WEATHER...
ISSUED AT 243 PM CDT WED APR 22 2015
TODAY HAS BEEN MOSTLY A DRYING DAY WEST OF THE MISSISSIPPI RIVER
WHERE MORE SUN HAS OCCURRED...CLOSER TO THE DRIER AIR OVER WESTERN
MN AND WINDS HAVE BEEN GUSTING 30-40 MPH. A WARMER DAY IS EXPECTED
ACROSS THE REGION ON THURSDAY WITH SUNNY SKIES. ADDITIONALLY...THE
DRY AIR OVER WESTERN MN MOVES IN...PLUMMETING RH VALUES TO 20-30
PERCENT. HOWEVER...WINDS DO NOT LOOK NEARLY AS STRONG WITH HIGH
PRESSURE MOVING IN...ONLY IN THE 10 TO 15 MPH RANGE. WITH SOME
GREEN-UP ALREADY OCCURRING AND THE LIGHTER WINDS...HAVE DECLINED
TO CONSIDER ANY FIRE WEATHER HAZARDS AT THIS TIME. SOME RAIN
REMAINS ON TAP TO MOVE INTO THE REGION FOR FRIDAY...ALONG WITH
CLOUDS...WHICH BOTH SHOULD HELP MITIGATE FIRE WEATHER CONCERNS.
LOOKING AHEAD...SUNDAY COULD BE ANOTHER DAY WORTH WATCH FOR FIRE
WEATHER CONCERNS...BUT SIMILAR TO THURSDAY WINDS ARE EXPECTED ON
THE LIGHTER SIDE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR IAZ008-018-019-029.
&&
$$
UPDATE...BOYNE
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
326 PM CDT TUE APR 21 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 326 PM CDT TUE APR 21 2015
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO ALBERTA AND VERY DEEP
TROUGHING OVER THE FORECAST AREA INTO THE GREAT LAKES. WITHIN THIS
TROUGH WAS AN UPPER LOW OVER EASTERN LAKE SUPERIOR...A SHORTWAVE
DROPPING SOUTH TOWARDS I-90 IN THE FORECAST AREA...AND ANOTHER
SHORTWAVE OVER NORTHEAST MN. COOL TEMPERATURES ALOFT REFLECTED BY
500MB TEMPS OF -27 TO -33C PER 12Z RAOBS...DAYTIME HEATING...NEAR
SATURATED CONDITIONS BETWEEN 700-850MB AND THE AFOREMENTIONED
SHORTWAVES HELPING TO PRODUCE PLENTY OF SHOWERS ACROSS THE
REGION....ESPECIALLY ALONG AND NORTH OF I-94. TEMPERATURES HAVE
STRUGGLED TO RISE WITH CLOUDS...PRECIP AND 850MB TEMPS OF -3 TO
-7C. READINGS HAVE ONLY CLIMBED INTO THE MID 30S TO LOW 40S. THE
COLD TEMPERATURES HAVE SUPPORTED A MIX OF RAIN AND SNOW...WITH THE
SNOW CONFINED MORESO TO HIGHER ELEVATIONS AND TAYLOR/CLARK
COUNTIES. ON TOP OF THE COOL AIR...A TIGHT PRESSURE GRADIENT AND
925MB WINDS OF 25-35 KT HAS RESULTED IN WINDS GUSTING TO THE 925MB
SPEEDS...MAKING IT FEEL FALL-LIKE. THESE WINDS ARE JUST BELOW
ADVISORY CRITERIA.
THE OVERALL UPPER PATTERN CHANGES LITTLE IN THE NEXT 24 HOURS WITH
ONLY A SLIGHT DRIFT EASTWARD OF THE UPPER LOW AND TROUGHING. THIS
SLIGHT DRIFT LOOKS TO BE ENOUGH SUCH THAT MUCH OF THE SHORTWAVE AND
INSTABILITY INDUCED SHOWERS ON WEDNESDAY WILL FALL EAST OF THE
FORECAST AREA. HOWEVER...PORTIONS OF TAYLOR AND ADAMS COULD GET
CLIPPED IN THE AFTERNOON. GETTING BACK TO TONIGHT...GENERAL MODEL
CONSENSUS SUGGESTS THE LOSS OF DAYTIME HEATING WILL ALLOW SHOWER
ACTIVITY TO BECOME MORE ISOLATED THROUGH THE EVENING...EVENTUALLY
ENDING BY MIDNIGHT.
CLOUDS LOOK TO HOLD OVER MUCH OF THE FORECAST AREA TONIGHT...AIDED
BY A SURGE OF 850MB MOISTURE CURRENTLY IN NORTHWEST ONTARIO DROPPING
SOUTHWARD WITH THE SHORTWAVE IN NORTHEAST MN. SUBSIDENCE IN THE WAKE
OF THIS SHORTWAVE...COMBINED WITH 925-700MB WINDS BACKING A BIT MORE
WESTERLY ON WEDNESDAY...WILL HELP TO RESULT IN MORE SUNSHINE.
DESPITE THE CLOUDS TONIGHT...AND A PERSISTENT BREEZE...TEMPERATURES
WILL STILL FALL AS THAT SHORTWAVE IN NORTHEAST MN DRAGS COLDER AIR
INTO THE FORECAST AREA. BY 12Z WED...850MB TEMPS ARE PROGGED TO DROP
TO -8 TO -11C...OR ALMOST 2 STANDARD DEVIATIONS BELOW NORMAL.
GUIDANCE LOWS IN THE MID 20S TO LOW 30S SEEM REASONABLE. HAVING MORE
SUNSHINE ON WEDNESDAY WILL HELP PRODUCE A WARMER DAY THAN
TODAY...ALBEIT STILL WELL BELOW NORMAL GIVEN 850MB TEMPS ONLY
CLIMBING TO -2 TO -7C BY 00Z THU. MOST LOCATIONS SHOULD CLIMB INTO
THE 40S...WITH LOW 50S LIKELY IN RIVER VALLEYS AND THE SOUTHWEST
PORTION OF THE FORECAST AREA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 326 PM CDT TUE APR 21 2015
THE UPPER FLOW PATTERN LOOKS TO BECOME MORE PROGRESSIVE THROUGH THE
END OF THE WEEK IN RESPONSE TO A DEEP UPPER TROUGH APPROACHING THE
PACIFIC NORTHWEST. THIS WILL HELP TO PUSH THE UPPER RIDGING AND
WARMER AIR OVER THE WESTERN U.S. TOWARDS THE FORECAST AREA. 850MB
TEMPS DO NOT CHANGE A WHOLE LOT WED NIGHT...BUT MORE IMPRESSIVE WARM
ADVECTION COMES IN FOR THU WITH 850MB TEMPS REACHING 0 TO -2C BY 00Z
FRI...AND 0 TO 4C BY 00Z SAT. LOW PRECIPITABLE WATER ON
THURSDAY...AROUND 0.1 INCHES...SHOULD HELP TO TANK DEWPOINTS AND
RESULTING RHS. COMBINED WITH A DRYING DAY ON WEDNESDAY AND A 10-15
MPH NORTHWEST BREEZE...FIRE WEATHER COULD BE A CONCERN. SEE FIRE
WEATHER SECTION BELOW.
FOR FRIDAY INTO SATURDAY...AN UPPER LOW CURRENTLY NEAR LOS ANGELES
IS PROGGED TO LIFT THROUGH THE CENTRAL PLAINS AND TRACK EASTWARD
ACROSS ILLINOIS. ALTHOUGH THIS TRACK IS SOUTH OF THE FORECAST
AREA...MOISTURE ADVECTION SPREADS NORTHWARD AHEAD OF THE UPPER LOW
TO HELP PRODUCE SOME RAIN. THE SPEED HAS SLOWED DOWN A BIT...AND AS
A RESULT DELAYED THE SPREADING OF CHANCES OF RAINFALL EASTWARD ON
FRIDAY. FURTHER DELAYS MAY BE NEEDED. RAIN CHANCES SPREAD ACROSS THE
FORECAST AREA FRIDAY NIGHT AND THEN SHIFT TO SOUTH OF I-90 ON
SATURDAY...RESULTING FROM EASTERLY FLOW DRAGGING MORE DRY AIR INTO
NORTHERN SECTIONS. OVERALL APPEARS TO BE A LIGHT RAIN...WITH THE
HEAVIER RAIN TO THE SOUTH TIED TO THE UPPER LOW FORCING.
DRIER WEATHER LOOKS TO FOLLOW SATURDAY NIGHT AND SUNDAY AS UPPER
RIDGING BUILDS BACK INTO THE FORECAST AREA FROM THE WEST.
TEMPERATURES SHOULD REBOUND CLOSER TO NORMAL AS WELL WITH MORE SUN
ON SUNDAY AND 850MB TEMPS IN THE 0-4C RANGE.
FOR EARLY NEXT WEEK UNCERTAINTY BEGINS TO INCREASE. NOT SO MUCH ON
THE UPPER PATTERN WHERE MODELS ADVERTISE TROUGHING DEVELOPING FROM
THE NORTHEAST U.S. INTO THE SOUTHEAST U.S....BUT WITH PRECIPITATION
CHANCES AS THIS TROUGH DEVELOPS. THE 21.12Z GFS HAS A SHORTWAVE
TROUGH DROPPING THROUGH THE REGION TO BRING PRECIPITATION TO THE
AREA. MEANWHILE THE 21.12Z ECMWF AND CANADIAN SUGGEST A DRY
PERIOD AS HIGH PRESSURE DOMINATES AT THE SURFACE...WITH THE
AFOREMENTIONED SHORTWAVE TROUGH FALLING APART. FOR NOW HAVE WENT
WITH THE CONSENSUS AND HAVE 20-30 PERCENT CHANCES. HOW THIS
SHORTWAVE TROUGH EVOLVES ALSO HAS AN IMPACT ON TEMPERATURES. IN
THE CASE OF THE 21.12Z GFS...IT SUGGESTS 850MB TEMPS PLUNGE TO
AROUND -4C BY 12Z TUE...ABOUT 8C COLDER THAN THE ECMWF. ALSO
FOLLOWED CONSENSUS HERE FOR NOW WITH TEMPS JUST SHY OF NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1201 PM CDT TUE APR 21 2015
EXPECT WINDY CONDITIONS OUT OF THE NORTHWEST TO CONTINUE THROUGH
THE TAF PERIOD WITH GUSTS OF 25 TO 35 KT THIS AFTERNOON. VFR
SHOULD PERSIST WITH A BRIEF MVFR CEILING POSSIBLE WITH A HEAVIER
SHOWER THIS AFTERNOON. SOME GUIDANCE HINTS AT MVFR CEILINGS EARLY
WEDNESDAY MORNING AS BACK EDGE OF CLOUDS MOVE THROUGH.
HOWEVER...WITH MIX OF VFR AND MVFR UPSTREAM ACROSS MINNESOTA KEPT
CEILINGS AT VFR WITH SCATTERING OUT BY MID WEDNESDAY MORNING.
&&
.FIRE WEATHER...
ISSUED AT 326 PM CDT TUE APR 21 2015
AFTER SOME RECENT COOL/WET DAYS...CONDITIONS LOOK TO DRY OUT AGAIN
WEDNESDAY AND THURSDAY. RELATIVE HUMIDITIES ARE EXPECTED TO DROP
INTO THE 20S ON WEDNESDAY AND MAY EVEN DROP BELOW 20 PERCENT IN A
FEW SOUTHEAST MN LOCATIONS ON THURSDAY. FIGURE MUCH OF WEDNESDAY
WILL BE A DRYING DAY FOR FUELS GIVEN THE WET WEATHER...WITH A 15
TO 25 MPH NORTHWEST BREEZE AIDING IN THE DRYING. THEREFORE
THURSDAY WOULD APPEAR TO BE THE MORE CONCERNING DAY...THOUGH WINDS
LOOK LIGHTER IN THE 10 TO 15 MPH RANGE. NEVERTHELESS...WELL HAVE
TO KEEP A CLOSE EYE ON THURSDAY AND SEE TOO WHERE ALL THE
VEGETATION STANDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR MNZ086-087-094-095.
IA...WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR IAZ008>010-018-019-
029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...CC
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
341 AM CDT TUE APR 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 341 AM CDT TUE APR 21 2015
MAIN FCST CONCERNS THIS PERIOD...STRONG WINDS THIS AFTERNOON...
-SHRA/-SHSN CHANCES TODAY INTO THIS EVENING...TEMPERATURES.
06Z DATA ANALYSIS HAD A 984 MB LOW SOUTHWEST OF JAMES BAY CANADA
WITH BROAD TROUGHING TO THE SOUTHWEST INTO NORTHERN MN. TIGHT
PRESSURE GRADIENT AND STEEPER LOW LEVEL LAPSE RATES REMAINED ACROSS
THE REGION...ESPECIALLY MN/WI WHERE WEST TO NORTHWEST WINDS OF 15 TO
20MPH GUSTING 25-35 MPH WERE QUITE COMMON. ONE SHORTWAVE OVER
NORTHERN MN INTO NORTHWEST WI WITH THE MID LEVEL LOW COMBINED WITH
SOME DEEPER MOISTURE AND TIGHTER 925-700MB CYCLONIC FLOW/
CONVERGENCE WERE PRODUCING SOME -SN/-SHSN OVER NORTHEAST MN INTO THE
NORTHWEST 1/4 OF WI. FURTHER SOUTH...WIDELY SCT -SHRA/-SHSN NOTED
OVER EAST CENTRAL MN INTO WESTERN WI.
21.00Z MODELS LOOK TO HAVE INITIALIZED WELL. SOLUTIONS QUITE SIMILAR
AS THE MID LEVEL LOW OVER NORTHERN MN DROPS ACROSS THE U.P. OF MI
TODAY THIS MORNING/EARLY THIS AFTERNOON...THEN LIFTS INTO EAST
CENTRAL ONTARIO LATE TODAY/TONIGHT. SOLUTIONS GENERALLY FAVOR
COMPROMISE OF THE EARLIER RUNS WITH DEEP...COLD CYCLONIC FLOW OVER
THE UPPER MIDWEST THIS PERIOD. SOME DIFFERENCES ON LIGHT QPF
PRODUCTION UNDER/SOUTH OF THE MID LEVEL LOW TODAY BUT THIS NOT
UNEXPECTED. OVERALL SHORT-TERM FCST CONFIDENCE IS GOOD THIS CYCLE.
IN THE SHORT TERM...TIGHT PRESSURE GRADIENT REMAINS OVER THE AREA
AGAIN TODAY...WITH STEEP LOW LEVEL LAPSE RATES/MIXING TO 850MB THIS
AFTERNOON. BIT MORE WIND IN THE MIXED PORTION OF COLUMN THAN
SUNDAY...25-30KTS AT 925MB AND AROUND 35KTS AT 850MB. 700MB TEMPS
AROUND -16C AS WELL THIS AFTERNOON WITH POTENTIAL OF MIXING TO
800MB. WILL MATCH UP WITH THE NEIGHBORS AND ISSUE A WIND ADVISORY
FOR ROUGHLY THE SOUTHWEST 1/3 OF THE FCST AREA FROM 16Z-23Z TODAY.
MODEL SOUNDINGS/X-SECTIONS SHOWING CONSIDERABLE MOISTURE/SATURATION
IN THE 900-500MB LAYER TO ROTATE ACROSS ROUGHLY THE NORTHEAST 2/3 OF
THE FCST AREA TODAY. THIS WITH THE -16C 700MB COLD POOL...A LOBE OF
VORTICITY ROTATING AROUND THE UPPER LOW AND THE TIGHTER 925-700MB
CYCLONIC CONVERGENCE...SETS THE STAGE FOR AT LEAST SCT -SHRA/-SHSN
ACROSS THE NORTHEAST HALF OF THE FCST AREA TODAY. RAISED PRECIP
CHANCES A BIT TODAY ACROSS THE NORTHEAST HALF OF THE FCST AREA...
WITH 60+ PERCENT ACROSS THE FAR NORTH END. COLUMN COLD ENOUGH FOR -
SHSN AS FAR SOUTH AS I-90 THRU MID MORNING. DIURNAL WARMING/ MIXING
OF LOWER PORTION OF THE COLUMN LOOKS TO CHANGE BULK OF PRECIP TO -
SHRA BY LATE MORNING...BUT STRONGER SHOWER CORES AND DRIER AIR BELOW
900MB FOR EVAPORATIVE COOLING MAY ALLOW SOME -SN/SLEET/SNOW PELLET
SHOWERS TO OCCUR WELL INTO THE AFTERNOON. DAY CREW WILL HAVE TO
MONITOR WARMING...AND OBS...AND MAY NEED TO INCLUDE THAT IN GRIDS AS
THE DAY WEARS ON. SECONDARY SHORTWAVE ROTATES IN AND ACROSS THE
AREA THIS EVENING...WITH A BETTER PV ADVECTION SIGNAL. RAISED
-SHRA/ -SHSN CHANCES/LINGERED THEM LONGER OVER THE EAST SIDE OF
THE FCST AREA THIS EVENING. 925-500MB SUBSIDENCE AND DRYING OF THE
COLUMN SPREADS ACROSS THE FCST AREA LATE THIS EVENING/OVERNIGHT...
WITH AND END TO THE -SHRA/-SHSN. SOME CLEARING LATER TONIGHT AS
WELL. PRESSURE GRADIENT CONTINUES TO RELAX TONIGHT BUT SFC WINDS
LOOKING TO REMAIN IN THE 7-14KT RANGE FOR BOUNDARY LAYER MIXING.
EVEN WITH THE WINDS...LOWS LOOKING TO FALL TO NEAR/BELOW FREEZING.
A BIT EARLY FOR FROST/FREEZE HEADLINES AT THIS POINT...BUT ANOTHER
WEEK OF THE WARMER TEMPS OF LAST WEEK WOULD HAVE LIKELY MADE THEM
NEEDED. USED A BLEND OF THE GUIDANCE HIGHS/LOWS FOR TODAY/TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 341 AM CDT TUE APR 21 2015
MAIN FCST CONCERNS FOR WED THRU THU NIGHT...COLD TEMPERATURES.
20.12Z MODELS IN GOOD AGREEMENT WED/WED NIGHT FOR THE MID LEVEL LOW/
TROUGH AXIS TO DRIFT SLOWLY EAST...WITH THE UPPER MIDWEST UNDER A
COLD NORTHWEST FLOW ALOFT. HGTS SLOWLY RISE THU/THU NIGHT AS THE LOW
PULLS INTO MAINE/QUEBEC AND TROUGHING MOVES INTO THE ROCKIES BUT
FLOW REMAINS OUT OF THE NORTHWEST. WITH THE TIGHTER/IMPROVING
CONSENSUS...FCST CONFIDENCE IN THE WED THRU THU NIGHT PERIOD IS GOOD
THIS CYCLE.
THE WED THRU THU NIGHT PERIOD IS DOMINATED BY SEASONABLY COLD AND
DRY CAN HIGH PRESSURE. SOME MOISTURE FROM LK SUPERIOR...STEEP LOW
LEVEL LAPSE RATES AND THE COLD AIR ALOFT LOOK TO SPREAD A SMALL -
SHRA/-SHSN CHANCE INTO THE FAR NORTH END OF THE FCST AREA WED...
OTHERWISE WED-THU NIGHT TREND DRY AS THE SFC RIDGE AXIS SLOWLY
DRIFTS EAST TOWARD/OVER THE AREA. 925MB TEMPS IN THE 0C TO -6C RANGE
AT 12Z THU AND IN THE +4C TO -2C RANGE AT 12Z FRI. NAEFS SHOWING
850MB TEMPS 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL ACROSS MUCH OF
THE UPPER MIDWEST THRU 12Z FRI. SFC RIDGE AXIS MAY BE CLOSE ENOUGH
FOR WINDS TO DECOUPLE WED NIGHT BUT THIS LOOKS MORE CERTAIN THU
NIGHT WITH THE RIDGE AXIS SOMEWHERE OVER WI. BOTH NIGHT TRENDING
COLD WITH LOWS NEAR OR BELOW 32F. AGAIN...A WEEK OR SO LATER IN THE
SEASON/MORE ADVANCED GROWTH/DEVELOPMENT OF VEGETATION AND FROST/
FREEZE HEADLINES WOULD BE NEEDED. APPROACH OF THE HIGH PRESSURE AND
SLOWLY RISING HGTS ALOFT TO BRING MORE SUNSHINE TO THE AREA
WED/THU. DEEP MIXING TO 750MB INDICATED FOR WED...WITH WINDS IN THE
900-750MB PORTION OF THE COLUMN STILL IN THE 20-30KT RANGE. BREEZY
AGAIN WED AFTERNOON...BUT LESS SO THAN SUNDAY AND TODAY. MORE
SUNSHINE WED/THU WILL HELP HIGH TEMPS RECOVER INTO THE 50S. USED
A BLEND OF THE GUIDANCE HIGHS/LOWS FOR WED THRU THU NIGHT.
FOR FRIDAY THRU MONDAY...DAYS 4 TO 7...
MAIN FCST CONCERNS THIS PERIOD...MAINLY RAIN CHANCES FRI/FRI NIGHT
AND AGAIN LATE SUN INTO MON...TEMPERATURES.
21.00Z MEDIUM RANGE MODELS IN GENERAL AGREEMENT FOR THE PATTERN TO
BE PROGRESSIVE FRI/SAT WITH RISING HGTS OVER THE EASTERN CONUS AND
TROUGHING MOVING THRU THE ROCKIES INTO THE PLAINS. HOWEVER PLENTY OF
SHORTWAVE DETAIL DIFFERENCES ALREADY BY FRI...WHICH WOULD IMPACT THE
SENSIBLE WEATHER ACROSS THE UPPER MIDWEST. AGREEMENT FOR WEAK SHORT-
WAVE RIDGING OT BUILD INTO THE REGION SAT. NEXT STRONGER TROUGHING
IS INTO THE PLAINS SUNDAY...THEN APPROACHING/CROSSING THE REGION SUN
NIGHT/MON. RUN-TO-RUN CONSISTENCY LEAVES QUITE A BIT TO BE DESIRED
BY SUN/MON WITH TROUGHS OFF BOTH COASTS AND UNCERTAIN FLOW ACROSS
THE CONUS BETWEEN THEM. FCST CONFIDENCE FOR FRI THRU MON...AS FAR AS
PRECIP CHANCES IS BELOW AVERAGE. AVERAGE CONFIDENCE FOR TEMPERATURES
TO RETURN TO NEAR NORMAL BY SUN/MON.
TROUGHING MOVING INTO THE PLAINS FRI DEVELOPS LOW PRESSURE OVER THE
CENTRAL/SOUTHERN PLAINS...BUT QUESTION IS NOW FAR NORTH INTO THE
MID/UPPER MS VALLEY THE INFLUENCE OF THIS LOW GETS. ECMWF/GEM WITH
MORE SHORTWAVE RIDGING AHEAD OF THIS FEATURE...AND WOULD SPREAD
MOISTURE/PRECIP CHANCES INTO MN/IA/WI FRI/FRI NIGHT. GFS WITH LESS
SHORTWAVE RIDGING HOLDS NORTHWEST FLOW ALOFT OVER THE REGION THRU
FRI NIGHT...AND KEEPS MN/IA/WI DRY. WITH LESSER CONFIDENCE STAY WITH
THE SMALL CONSENSUS MAINLY -SHRA CHANCES FRI/FRI NIGHT. RISING HGTS/
SHORTWAVE RIDGING WOULD BRING DRY HIGH PRESSURE TO THE REGION FOR
SAT/SAT NIGHT. NEXT TROUGH THRU THE ROCKIES DEVELOPS LEE TROUGHING
FROM MT TO TX ON SUN...WITH SOME FORM OF THIS TROUGH/LOW PUSHING
INTO THE MID/UPPER MS VALLEY SUN NIGHT/MON. DEEPER SOUTHERLY FLOW
AHEAD OF THIS SYSTEM WOULD BRING WARMER LOW LEVEL AIR/INCREASING
MOISTURE NORTHWARD FOR SUN INTO MON. RAIN CHANCES OF 20-30 PERCENT
SUN NIGHT/MON PER THE MODEL/ENSEMBLE CONSENSUS APPEAR REASONABLE.
MODEL/ENSEMBLE CONSENSUS OF THE HIGHS/LOWS FOR FRI THRU MON ALSO
APPEAR WELL TRENDED FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1140 PM CDT MON APR 20 2015
THE WESTERN EDGE OF THE CLOUD DECK HAS BEEN ERODING SOME THIS
EVENING. HOWEVER...LOOKING UPSTREAM INTO MINNESOTA...IT LOOKS LIKE
THE WESTERN EDGE HAS BEEN HOLDING FIRM AND AS THIS ROTATES DOWN
ACROSS THE AREA...EXPECT THAT SKIES WILL BE REMAIN BROKEN TO
OVERCAST THROUGH TUESDAY. FOR THE MOST PART THE CEILINGS HAVE
REMAINED VFR...BUT STILL EXPECTING THESE TO COME DOWN TO MVFR.
CURRENT MVFR CEILINGS ARE UPSTREAM OVER CENTRAL MINNESOTA AND
THESE SHOULD ROTATE ACROSS THE AREA OVERNIGHT. STILL SOME RETURNS
ON THE RADAR WITH THE 21.02Z HRRR CONTINUING TO SHOW SOME
SCATTERED ACTIVITY THROUGH THE NIGHT...BUT CONFIDENCE THAT ANY OF
THESE WILL HIT THE TAF SITES REMAIN LOW. THE 21.00Z NAM BUFKIT
SOUNDINGS CONTINUE TO SHOW THE GOOD LOW LEVEL LAPSE RATES
REMAINING THROUGH THE ENTIRE PERIOD TO MAINTAIN THE GUSTY WEST TO
NORTHWEST WINDS. THE STRONGEST WINDS WILL COME LATE TUESDAY
MORNING THROUGH THE AFTERNOON WHEN THE MIXING BECOMES THE DEEPEST
ALLOWING THE GUSTS TO BE AROUND 30 KNOTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WIND ADVISORY FROM NOON TODAY TO 6 PM CDT THIS EVENING FOR
MNZ086-087-094-095.
IA...WIND ADVISORY FROM NOON TODAY TO 6 PM CDT THIS EVENING FOR
IAZ008>010-018-019-029-030.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CDT MON APR 20 2015
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 235 PM CDT MON APR 20 2015
500 MB LOW/UPPER LEVEL TROUGH MEANDERS SLOWLY EASTWARD ACROSS THE
UPPER MISSISSIPPI RIVER TONIGHT-TUE...THEN WOBBLES OVER SOUTHEAST
CANADA FOR A FEW DAYS. BITS OF UPPER LEVEL ENERGY WILL ROTATE AROUND
THE UPPER LEVEL FEATURE BUT THE DEEPER SATURATION HOLDS ACROSS
NORTHERN PARTS OF MN/WI. STRONG SWATH OF 925-700 MB COLD AIR
ADVECTION DRIVES SOUTHEAST TONIGHT-TUE...GREATER ACROSS IA. BUFKIT
SOUNDINGS STILL SHOWING AS MUCH AS A 100 MB LAYER OF WEAK
INSTABILITY TUE AFTERNOON...ASSOCIATED WITH A SATURATED LAYER. ALL
IN ALL...THE MIX OF CYCLONIC UPPER LEVEL FLOW...LOW LEVEL COLD AIR
ADVECTION...WEAK INSTABILITY...FAVORABLY LOW/MID LEVEL LAPSE
RATES...AND SOME SATURATION FAVORS AREAS/SCATTERED SHOWERS.
LOCATIONS TO THE NORTH WILL HAVE THE BEST CHANCES...SPREADING
SOUTHWARD TUESDAY AFTERNOON. SOME SNOW COULD MIX IN TO THE NORTH
EARLY/LATE.
BUFKIT SOUNDINGS POINT TO DEEP MIXING ON TUESDAY...ESPECIALLY SOUTH
OF I-90 INTO IOWA. MIXING UPWARDS OF 800 MB WITH MOMENTUM TRANSFER
OF 30 TO 35 KTS. SFC PRESSURE GRADIENT TUE FAIRLY SIMILAR TO THIS
AFTERNOON. EXPECTING CLOUDY/MOSTLY CLOUDY CONDITIONS FOR THE I-90
CORRIDOR NORTHWARD...LIMITING THE MIXING. WITH MORE SUN SOUTH...FULL
MIXING COULD BE REALIZED. SEE SOME POTENTIAL FOR WIND ADV TUE
AFTERNOON - ESPECIALLY PARTS OF NORTHEAST IA. SOMETHING TO WATCH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 235 PM CDT MON APR 20 2015
GOOD AGREEMENT IN THE MODELS WITH PERSISTENT COOL NORTHWEST FLOW
THROUGH THE REST OF THE WORK WEEK. DIFFERENCES CROP UP FOR THE
WEEKEND AS THE ECMWF/GEM POINT TO SOME WEAK UPPER LEVEL RIDGE
BUILDING WHILE THE GFS MAINTAINS THE TROUGH - EVEN DEEPENING
IT/CARVING IT OUT MORE. WHILE ALL SOLUTIONS FAVOR KEEPING THE LOCAL
AREA DRY...THERE WOULD BE IMPACTS ON TEMPS. THE GFS WOULD KEEP HIGHS
IN THE LOW/MID 50S WHILE THE EC POINTS TO A RETURN TO NORMAL -
AROUND 60. MODELS HAVE BEEN FAIRLY CONSISTENT WITHIN
THEMSELVES...BUT STILL NOT SOLD ON THE RIDGING. WILL STICK WITH
CONSENSUS SOLUTIONS FOR THE WEEKEND FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1140 PM CDT MON APR 20 2015
THE WESTERN EDGE OF THE CLOUD DECK HAS BEEN ERODING SOME THIS
EVENING. HOWEVER...LOOKING UPSTREAM INTO MINNESOTA...IT LOOKS LIKE
THE WESTERN EDGE HAS BEEN HOLDING FIRM AND AS THIS ROTATES DOWN
ACROSS THE AREA...EXPECT THAT SKIES WILL BE REMAIN BROKEN TO
OVERCAST THROUGH TUESDAY. FOR THE MOST PART THE CEILINGS HAVE
REMAINED VFR...BUT STILL EXPECTING THESE TO COME DOWN TO MVFR.
CURRENT MVFR CEILINGS ARE UPSTREAM OVER CENTRAL MINNESOTA AND
THESE SHOULD ROTATE ACROSS THE AREA OVERNIGHT. STILL SOME RETURNS
ON THE RADAR WITH THE 21.02Z HRRR CONTINUING TO SHOW SOME
SCATTERED ACTIVITY THROUGH THE NIGHT...BUT CONFIDENCE THAT ANY OF
THESE WILL HIT THE TAF SITES REMAIN LOW. THE 21.00Z NAM BUFKIT
SOUNDINGS CONTINUE TO SHOW THE GOOD LOW LEVEL LAPSE RATES
REMAINING THROUGH THE ENTIRE PERIOD TO MAINTAIN THE GUSTY WEST TO
NORTHWEST WINDS. THE STRONGEST WINDS WILL COME LATE TUESDAY
MORNING THROUGH THE AFTERNOON WHEN THE MIXING BECOMES THE DEEPEST
ALLOWING THE GUSTS TO BE AROUND 30 KNOTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
347 AM MDT TUE APR 21 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 315 AM MDT TUE APR 21 2015
QUIET WEATHER THIS MORNING WITH SOME MID CLOUDS OVER SE WY KEEPING
TEMPS UP A BIT AND HINDERING ANY FOG FORMATION. NWLY FLOW ALOFT
WILL REMAIN OVER THE CWA THROUGH WEDS THEN TURN WESTERLY WEDS
NIGHT AND THURSDAY. A WEAK FRONT WILL SETTLE DOWN THE PLAINS LATER
THIS AFTERNOON INTO THIS EVENING AND LAY UP AGAINST THE MTNS BUT
NO SIGNIFICANT EFFECT SEEN FROM THIS THROUGH TONIGHT. SOME WEAK
INSTABILITY OVER WESTERN PARTS OF THE CWA SHOULD ALLOW FOR A FEW
SHOWERS TO DEVELOP THIS AFTERNOON WITH A TSTORM OR TWO NOT OUT OF
THE QUESTION. ACTIVITY WILL DECREASE THIS EVENING. AN APPROACHING
SHORTWAVE ON WEDS SHOULD ALLOW FOR SOMEWHAT BETTER COVERAGE OF
SHOWERS AND A FEW TSTORMS WEDS...MAINLY OVER SE WY WHERE SOME
MINOR UPSLOPE COMPONENT TO THE WIND SHOULD EXIST. SIMILAR PATTERN
FOR THURSDAY BUT PCPN SHOULD PROGRESS FARTHER EASTWARD OVER THE
PLAINS AND THE PANHANDLE AS THE SFC FRONT SLIPS BACK EAST.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM MDT TUE APR 21 2015
MINOR DIFFERENCES ARE APPARENT WITH THE 00Z/06Z DETERMINISTIC
MODEL GUIDANCE. FAIRLY BROAD UPPER TROUGH OVER THE INTERMOUNTAIN
WEST WILL PROGRESS EASTWARD WITH WEAK UPPER LOW MOVING SLOWLY
FROM THE FOUR CORNERS TO SOUTHEAST CO THURSDAY NIGHT AND CENTRAL
GREAT PLAINS BY FRIDAY EVENING. A SURFACE TROUGH BISECTING A PAIR
OF LOWS WILL LIE EAST OF THE LARAMIE RANGE. A RATHER MOIST
SOUTHEASTERLY UPSLOPE FLOW WITH DEW POINTS IN THE 40S COMBINED
WITH MODEST INSTABILITY /LIS -3 TO -5C/ AND WEAK UPPER LEVEL
DISTURBANCE WILL PRODUCE A DECENT COVERAGE OF SHOWERS AND
ISOLATED TSTORMS THURSDAY NIGHT AND FRIDAY. SHOWER COVERAGE
DECREASES SLIGHTLY FRIDAY NIGHT WITH THE EXIT OF THE DISTURBANCE.
SHORTWAVE TRANSITORY RIDGE ALOFT EARLY SATURDAY SLIDES EAST INTO
THE PLAINS SATURDAY AFTERNOON WHEN A STRONGER DISTURBANCE MOVES
ACROSS WY AND CO PRODUCING SCATTERED SHOWERS AND POSSIBLY A FEW
TSTORMS. THE GFS IS MORE PROGRESSIVE WITH THIS TROUGH AND CLEARS
OUT THE SHOWERS SATURDAY NIGHT WHILE THE ECMWF IS SLOWER AND KEEPS
THE CWA SHOWERY THROUGH SUNDAY. AREAS ALONG AND SOUTH OF I-80 IN
SOUTHEAST WY MAY SEE ISOLATED SHOWERS SUNDAY AFTERNOON WITH WEAK
OROGRAPHIC FLOW. A DRIER STABLE AIR MASS WILL PREVAIL MONDAY WITH
LARGE SCALE RIDGE OVER THE ROCKY MOUNTAINS. TRENDED TOWARD THE
COOLER ECMWF BIAS FOR TEMPERATURES WHICH WILL AVERAGE NEAR TO
SLIGHTLY ABOVE SEASONAL NORMALS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 239 AM MDT TUE APR 21 2015
DEVELOPMENT OF PATCHY DENSE FOG IN THE LARAMIE VALLEY EARLY THIS
MORNING IS NOT FAVORABLE GIVEN THE LARGER TEMP/DEW POINT SPREADS
AND BKN-OVC CLOUDS AROUND 8000 FT AGL. THE SREF AND HRRR PREDICT
VFR CONDITIONS. THERE COULD BE SOME MIFG AROUND...BUT SHOULD HAVE
LIMITED IMPACTS TO AVIATION. OTHERWISE...VFR WILL PREVAIL ACROSS
THE FORECAST AREA TODAY AND TONIGHT WITH OCCASIONAL MID AND HIGH
CLOUDS PASSING OVERHEAD IN NORTHWEST FLOW. IT WILL BE BREEZY WITH
WEST TO NORTHWEST SURFACE WINDS SUSTAINED 12-18 KT...GUSTING UP TO
30 KT. THE WINDS WILL DIMINISH EARLY THIS EVENING WITH THE
DECOUPLING OF THE LOW LEVEL BOUNDARY LAYER.
&&
.FIRE WEATHER...
ISSUED AT 315 AM MDT TUE APR 21 2015
CONCERNS EXPECTED TO REMAIN LOW FOR THE NEXT SEVERAL DAYS WITH
WEATHER CONDITIONS REMAINING NON-CRITICAL OVERALL. A FEW
THUNDERSTORMS WILL BE POSSIBLE MAINLY IN THE AFTERNOONS FOR THE
NEXT FEW DAYS BUT DRY LIGHTNING IS NOT EXPECTED. TEMPERATURES
WILL BE MILD THROUGH THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...RE
LONG TERM...MJ
AVIATION...MJ
FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1242 AM MDT TUE APR 21 2015
.UPDATE...
ISSUED AT 953 PM MDT MON APR 20 2015
MAIN CONCERN OVERNIGHT IS CERTAINLY THE POTENTIAL FOR FOG
DEVELOPMENT FOR AREAS WEST OF THE LARAMIE RANGE...INCLUDING I-80
BETWEEN RAWLINS AND LARAMIE. 00Z NAM IS KEEPING FOG AT BAY WITH
LOW BL HUMIDITIES AND A DRIER NEAR SURFACE LAYER BASED OFF THE
KLAR FORECAST SOUNDINGS. HRRR IS ALSO CONSISTENTLY SHOWING NO
DEVELOPMENT OF FOG OVERNIGHT. BASED ON THIS ENSEMBLE OF
GUIDANCE...AND SOME MID CLOUDS DEVELOPING AND MOVING IN FROM THE
NORTHWEST WITH A FORECAST WIND DIRECTION FROM THE SOUTHWEST...AM
NOT SO CONFIDENT WIDESPREAD DENSE FOG WILL DEVELOP OVERNIGHT.
LINGERING SNOWPACK AND LIGHT WINDS WILL CERTAINLY AID IN
DEVELOPMENT OF MORE PATCHY AREAS OF FOG ESPECIALLY LATE IN THE
NIGHT IN THE LARAMIE VALLEY...WITH VISIBILITIES DROPPING TO
PERHAPS ONE HALF MILE OR SO...BUT A WIDESPREAD EVENT SEEMS
UNLIKELY AT THIS TIME. THE HIGHEST PROBABILITY OF FOG WILL BE FOR
EASTERN AND SOUTHERN PORTIONS OF THE LARAMIE VALLEY...AND PERHAPS
NORTHERN CARBON COUNTY AS WELL. WILL HOLD OF ON ISSUING A DENSE
FOG ADVISORY FOR NOW DUE TO LOW CONFIDENCE...BUT WILL CLOSELY
MONITOR THE SITUATION.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 250 PM MDT MON APR 20 2015
TONIGHT...LOOKS LIKE ENOUGH INSTABILITY IN THE THETA E RIDGE ACROSS
OUR FAR SOUTHWEST COUNTIES FOR ISOLATED TO WIDELY SCATTERED EARLY
EVENING SHOWERS OVER SOUTHERN CARBON AND ALBANY COUNTIES. DRY
ELSEWHERE. BASED ON PERSISTENCE...WILL AGAIN FORECAST AREAS OF FOG
OVERNIGHT AND ESPECIALLY AFTER MIDNIGHT FOR MUCH OF CARBON COUNTY
AND ESPECIALLY OVER THE LARAMIE VALLEY AND THE SNOWPACK WHERE
TEMPERATURE AND DEWPOINT SPREADS ARE STILL ONLY 2 DEGREES AT MID
AFTERNOON.
TUESDAY...NON DESCRIPT NORTHWEST FLOW ALOFT CONTINUES. LOOKS LIKE
ENOUGH LOW AND MID LEVEL MOISTURE ALONG WITH DIFFERENTIAL HEATING
AND UPSLOPE TO GENERATE ISOLATED TO WIDELY SCATTERED AFTERNOON
SHOWERS...WITH ISOLATED THUNDERSTORMS WEST OF INTERSTATE 25.
TUESDAY NIGHT...SHOWERS AND THUNDERSTORMS SHOULD END IN THE EVENING
WITH THE LOSS OF DAYTIME HEATING AND LACK OF SIGNIFICANT
LIFTING...THOUGH STILL ENOUGH LOW AND MID LEVEL MOISTURE FOR
SCATTERED TO BROKEN CLOUD COVER...AND AREAS OF FOG ONCE AGAIN OVER
THE LARAMIE VALLEY.
WEDNESDAY...TRANSITORY RIDGING ALOFT MOVES OVERHEAD. STILL
THOUGH...ENOUGH LOW AND MID LEVEL MOISTURE AND INSTABILITY FOR
ISOLATED TO SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS WITH AN
INCREASE IN THUNDERSTORM COVERAGE DUE TO INCREASED INSTABILITY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 250 PM MDT MON APR 20 2015
SHORTWAVE RIDGE MOVES OVER THE AREA WEDNESDAY NIGHT. MOST AREAS
EAST OF THE LARAMIE RANGE WILL BE DRY...THOUGH GFS DOES SHOW SOME
LIGHT SHOWERS OUT OVER CARBON COUNTY INTO THURSDAY MORNING.
RIDGE AXIS MOVES EAST OF THE CWFA THURSDAY WITH AN UPPER SHORTWAVE
PUSHING INTO NORTHWESTERN COLORADO AND WESTERN WYOMING. BOTH THE
GFS AND ECMWF PAINTING MODERATE QPF OVER THE CWFA THURSDAY
AFTERNOON. LIFTED INDICES -2 TO -4C ACROSS THE CWFA WITH -5 TO -6C
ACROSS THE PANHANDLE. ADDED THUNDERSTORM MENTION IN THE FORECAST
FOR THURSDAY AFTERNOON/EVENING.
FRIDAY COULD BE AN INTERESTING DAY THUNDERSTORM WISE AS A SURFACE
LOW DEVELOPS OVER NORTHEASTERN COLORADO. UPPER LEVEL LOW ALMOST
VERTICALLY STACKED OVER THE SURFACE LOW ON BOTH THE GFS AND
ECMWF. GFS MOST BULLISH ON QPF...WITH AN AREA OVER HEAVY RAIN OVER
THE SOUTHERN PANHANDLE. LOW SLOW TO MOVE OUT OF THE AREA WITH
SHOWER ACTIVITY CONTINUING INTO SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1238 AM MDT TUE APR 21 2015
VFR CONDITIONS WILL PREVAIL OVERNIGHT WITH SCATTERED HIGH CLOUDS
OVER SOUTHEAST WY. AREAS OF IFR-LIFR CONDITIONS IN FOG WILL BE
POSSIBLE ACROSS THE LARAMIE VALLEY INCLUDING KLAR BETWEEN 10Z AND
14Z TUESDAY. OTHERWISE...SCATTERED TO BROKEN MID AND HIGH CLOUDS
ARE EXPECTED DURING THE DAY. IT WILL BE BREEZY TUESDAY AS WEST TO
NORTHWEST WINDS GUST BETWEEN 25 AND 30 KT...EXCEPT FOR VALLEY
LOCATIONS.
&&
.FIRE WEATHER...
ISSUED AT 250 PM MDT MON APR 20 2015
RECENT RAIN AND CONTINUED SNOW PACK FROM LAST WEEKS STORM WILL
KEEP FIRE WEATHER CONCERNS MINIMAL THROUGH THE WEEK. GOING TO SEE
INCREASED CHANCES FOR WETTING RAINS AND MOUNTAIN SNOWS LATE IN THE
WEEK AS ANOTHER PACIFIC LOW PRESSURE SYSTEM TRACKS ACROSS NORTHERN
COLORADO.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RJM
SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...MJ
FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
421 AM EDT THU APR 23 2015
.SHORT TERM (TODAY-FRIDAY)...
A CONVECTIVE COMPLEX OVER THE CENTRAL-EASTERN GULF OF MEXICO EARLY
THIS MORNING IS ASSOCIATED WITH A VORT MAX THAT WILL CONTINUE TO
SHIFT EASTWARD THROUGH THE REST OF THE MORNING HOURS. RADAR
IMAGERY SHOWS SOME SHOWERS OVER THIS REGION AND WOULD EXPECT THIS
ACTIVITY TO SHIFT EASTWARD AS WELL...MAKING IT INTO OUR SOUTHERN
COASTAL WATERS AND POSSIBLY EVEN COASTAL SOUTHWEST FLORIDA BEFORE
DAYBREAK. THIS IS SUPPORTED BY THE LATEST HRRR AND OTHER HIGH-RES
GUIDANCE. FOR THE REST OF TODAY...ANOTHER VORT MAX WILL APPROACH
FROM THE NORTHWEST WITH WEAK HIGH PRESSURE AT THE SURFACE AND A
FRONTAL BOUNDARY MOVING INTO THE SOUTHEAST. AS FAR AS RAIN CHANCES
GO...EXPECT THE ACTIVITY OVER THE GULF TO SHIFT SOUTHEAST THROUGH
THE MORNING AND THEN WE WILL TRANSITION TO MORE SEA-BREEZE/DIURNAL
SHOWERS AND THUNDERSTORMS FOR THE AFTERNOON HOURS...WITH THE BEST
CHANCES OVER INLAND AREAS AS THE WEST COAST SEA BREEZE FORMS AND
SHIFTS INLAND. THE WEAK FRONTAL BOUNDARY WILL SINK SOUTH INTO
NORTHERN FLORIDA TONIGHT INTO EARLY FRIDAY WITH MOSTLY QUIET
CONDITIONS EXPECTED ACROSS THE FORECAST AREA. UPPER-LEVEL RIDGING
WILL START TO BUILD OVER THE GULF DURING THE DAY WITH SURFACE HIGH
PRESSURE CENTERED TO THE NORTHEAST. SHOWER AND THUNDERSTORM
ACTIVITY DURING THE AFTERNOON WILL BE FOCUSED MAINLY OVER
SOUTHWEST FLORIDA. AS FAR AS TEMPERATURES...STILL LOOKING AT ABOVE
NORMAL VALUES TO END THE WEEK.
.LONG TERM (FRIDAY NIGHT-THURSDAY)...
CUT-OFF U/L LOW WILL MOVE OVER NEW ENGLAND WITH THE TROUGH AXIS
WELL OFF THE EASTERN SEABOARD. WEST COAST TROUGH WILL PERSIST WITH
BROAD RIDGING DOWNSTREAM OVER THE GULF OF MEXICO WITH A RIDGE AXIS
NORTH THROUGH THE TENNESSEE VALLEY. AN U/L DISTURBANCE WILL BE
EJECTED EAST ACROSS THE MID/LOWER MISSISSIPPI VALLEY FRIDAY NIGHT
TO THE TENNESSEE VALLEY ON SATURDAY. ONSHORE WESTERLY BOUNDARY
LAYER FLOW ACROSS THE FLORIDA PENINSULA WILL PUSH THE WEST COAST
SEA BREEZE BOUNDARY INLAND RATHER QUICKLY...WHICH WILL KEEP MOST
AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY EAST OF THE FORECAST
AREA.
U/L ENERGY OVER THE PACIFIC NORTHWEST WILL SINK SOUTHEAST AND CUT-
OFF OVER THE FOUR CORNERS AREA SUNDAY WITH STRONG U/L QUASI-ZONAL
FLOW PERSISTING ACROSS THE SOUTHERN TIER OF THE U.S. A WEAK FRONTAL
BOUNDARY WILL STALL ACROSS THE SOUTHEAST U.S. WITH DEEP TROPICAL
MOISTURE SOUTH OF THE BOUNDARY ACROSS THE FLORIDA PENINSULA. A WEAK
U/L DISTURBANCE WILL TRACK ACROSS THE FLORIDA PENINSULA SUNDAY WITH
A CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS MAINLY NORTH OF THE
TAMPA BAY AREA AND OVER THE INTERIOR. THE U/L LOW OVER THE
SOUTHWEST U.S. WILL BEGIN TO OPEN UP AND PUSH EAST ACROSS THE
SOUTHERN PLAINS MONDAY WHICH WILL INDUCE WEAK U/L RIDGING OVER THE
GULF OF MEXICO. COMBINATION OF DAYTIME HEATING AND SUFFICIENT DEEP
LAYER MOISTURE AND WEAK ATMOSPHERIC INSTABILITY WILL CREATE A CHANCE
OF AFTERNOON SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA
MONDAY AFTERNOON.
COMPLEX PATTERN TAKING SHAPE MIDDLE OF NEXT WEEK AS THE U/L LOW
MOVING OUT OF THE SOUTHERN PLAINS MAY BE ABSORBED BY NORTHERN STREAM
ENERGY OVER THE MID MISSISSIPPI RIVER VALLEY ON TUESDAY. THIS WILL
CREATE GOOD U/L DIFFLUENCE OVER THE LOWER MISSISSIPPI VALLEY WITH AN
AREA OF LOW PRESSURE DEVELOPING AND PUSHING SLOWLY EAST TO THE
SOUTHEAST U.S. ON WEDNESDAY. HIGH DEGREE OF UNCERTAINTY ON THIS
EVOLVING SYSTEM AS THE U/L PATTERN SUGGESTS A DIGGING STRONG U/L
DISTURBANCE APPROACHING THE SOUTHEAST U.S. WITH STRONG DYNAMICS/LIFT
DEVELOPING OVER WEST CENTRAL AND SOUTHWEST FLORIDA TUESDAY NIGHT AND
WEDNESDAY. A COLD FRONT WILL MOVE ACROSS THE EASTERN GULF OF MEXICO
AND THE FLORIDA PENINSULA TUESDAY NIGHT AND WEDNESDAY WITH
SHOWERS/THUNDERSTORMS LIKELY DEVELOPING AHEAD OF THE FRONT AND
SPREADING OVER THE FORECAST AREA WITH A FEW STRONG STORMS POSSIBLE
WITH LOCALLY HEAVY RAIN.
U/L ENERGY WILL LIFT RAPIDLY NORTHEAST ON THE EAST SIDE OF THE L/W
TROUGH WEDNESDAY NIGHT AND THURSDAY WITH THE SURFACE LOW LIFTING TO
THE MID ATLANTIC COAST. DRIER COOLER AIR WILL ADVECT ACROSS WEST
CENTRAL AND SOUTHWEST FLORIDA IN THE WAKE OF THE COLD FRONT.
&&
.AVIATION...
MAINLY VFR CONDITIONS ARE EXPECTED. THE EXCEPTION WILL BE ANY
THUNDERSTORMS THAT MOVE OVER TERMINALS...CAUSING BRIEF
RESTRICTIONS. WILL COVER THIS FOR NOW WITH VCTS MENTION AT ALL
SITES STARTING AT 18Z.
&&
.MARINE...
SHOWERS AND THUNDERSTORMS ARE POSSIBLE OVER THE COASTAL WATERS
TODAY...BUT OTHERWISE EXPECT BENIGN CONDITIONS TO CONTINUE
THROUGH THE FIRST PART OF THE WEEKEND WITH NO HEADLINES EXPECTED.
WINDS WILL INCREASE BRIEFLY LATE SATURDAY NIGHT INTO SUNDAY...BUT
THEN DIMINISH AGAIN FOR EARLY NEXT WEEK.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS AS RELATIVE HUMIDITY VALUES WILL REMAIN
ABOVE CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 85 73 89 72 / 40 20 20 0
FMY 88 72 89 73 / 50 20 30 10
GIF 88 70 88 71 / 50 20 20 10
SRQ 83 71 86 70 / 40 30 10 0
BKV 86 66 88 66 / 30 20 10 0
SPG 84 75 86 75 / 40 30 10 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...05/CARLISLE
LONG TERM/DECISION SUPPORT...13/OGLESBY
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
342 AM EDT THU APR 23 2015
.DISCUSSION...
TODAY AND TONIGHT...STRONG UPR ATMOSPHERIC WINDS WL CONTINUE
ACROSS THE REGION...PRODUCING A NOTABLE AMOUNT OF HIGHER LEVEL
CLOUDINESS. UNSETTLED CONDS WL BE OFFSET BY THE SOMEWHAT DRIER
OVERALL AIRMASS AND TEMPS AROUND -9C @ H5 WITH PWAT VALUES JUST
OVER AN INCH BUT RECOVERING. HAVE UNDERCUT THE HIGHER MOS
INDICATED POPS WHILE MAINTAINING MOSTLY SCT RAIN CHCS DURING THE
HEAT OF THE AFTN. LIGHT SFC GRADIENT CONDS WL LEAD TO A RICH
BOUNDARY INTERACTION ENVIRONMENT AT MID AFTERNOON WITH WLY UPR
STEERING WINDS FAVORING THE E SIDE OF THE PENINSULA FOR EVENTUAL
MOVEMENT OF SHRA/ISOLD/TS. LTST HRRR GUID KEEPS REMNANTS OF
CURRENT GULF MCS SOUTH OF THE FORECAST AREA WHILE SHOWING
ORGANIZED WEST COAST SOURCE PCPN AREA MIGRATING EWD ACROSS THE
SRN PENINSULA LATE AFTERNOON INTO EVENING.
FRIDAY...DRIEST DAY OF THE NEXT SEVERAL AS SURFACE HIGH MOVES OFF
SOUTH CAROLINA COAST AND LOW LEVEL FLOW VEERS NE/ENE IN THE
AFTERNOON ALONG WITH UPPER LEVEL RIDGE BUILDING INTO THE REGION. A
DRIER AIRMASS OVERALL WILL LIMIT CONVECTIVE COVERAGE TO FAR SRN AND
INTERIOR AREAS IN THE AFTERNOON WITH THE MORE ROBUST EAST COAST SEA
BREEZE.
HIGHS WILL RANGE FROM THE LOWER TO MID 80S COAST TO MID TO UPPER 80S
OVER THE INTERIOR. EVENING HOURS WILL REMAIN DRY WITH ANY SHOWERS
EXPECTED TO BE WEST OF THE REGION. LOWS UPPER 60S TO AROUND 70.
SAT-SUN...UPPER LEVEL RIDGE CROSSES THE STATE ON SAT AND IS QUICKLY
FLATTENED INTO SUN BY SHORTWAVE MOVING INTO THE MIDWEST/MID-
ATLANTIC. ACCOMPANYING THIS FEATURE WILL BE A SURFACE LOW CROSSING
THE MIDWEST/TN VALLEY AND PUSHING OFF THE CAROLINA COAST SUN
MORNING. ORIENTATION OF THE UPPER LEVEL FLOW WILL MEAN THE
ACCOMPANYING BOUNDARY WILL EARLY SAG INTO NORTH FLORIDA LATE
SATURDAY AND SUNDAY.
MID LEVEL MOISTURE WILL BE THE MAIN LIMITING FACTOR FOR CONVECTION
ON SATURDAY AS JET LEVEL DIVERGENCE REMAINS FAVORABLE AS WELL AS
BRISK STEERING FLOW KEEPING THE EAST COAST SEA BREEZE NEAR THE COAST
IN THE AFTERNOON. BETTER RAIN CHANCES INTO SUNDAY ESPECIALLY NORTH
OF ORLANDO AS MOISTURE ASSOCIATED WITH THE FRONT DROPS FURTHER
SOUTH.
WITHOUT THE SEA BREEZE TEMPERATURES REMAIN WELL ABOVE
NORMAL...POSSIBLY NEAR RECORDS IN SOME CASES...WITH HIGHS IN THE
UPPER 80S AND LOW 90S. OVERNIGHT LOWS IN THE 70S.
MON-WED...GFS HAS TRENDED TOWARDS THE ECMWF IN THE EXTENDED AND IS
LESS AGGRESSIVE IN POST FRONTAL DRYING ON MONDAY...KEEPING MORE
MOISTURE POOLED ACROSS THE SOUTH FLORIDA AND AROUND LAKE OKEECHOBEE
AS THE FRONT STALLS. THIS WILL KEEP RAIN CHANCES...AT LEAST ACROSS
OKEECHOBEE AND THE TREASURE COAST...SIMILAR TO SUNDAY.
GFS IS ALSO NOW SHOWING A MORE SOUTHERLY TRACK WITH THE UPPER LEVEL
LOW MEANDERING ACROSS THE SOUTHERN TIER OF THE US AND THEREFORE A
MORE SPLIT TRACK FLOW. AS WITH PREVIOUS RUNS OF THE ECMWF...THE
ASSOCIATED SURFACE LOW IS FORECAST TO TRACK ACROSS THE NORTHERN GULF
TUES AND WED AND ACROSS N FLORIDA INTO WED NIGHT. BEST RAIN CHANCES
THROUGH THESE DAYS WILL DEPEND ON WHERE THE WARM FRONTAL TYPE
BOUNDARY SETS UP ACROSS THE STATE AND HOW QUICKLY THE LOW CAN LIFT
OUT AND PULL THE FRONT THROUGH. OVERALL RAIN CHANCES CONTINUE ABOVE
NORMAL...WITH DAY TO DAY DIFFERENCES IMPOSSIBLE TO PREDICT THIS FAR
OUT. ABOVE NORMAL TEMPS CONTINUE THROUGH TUESDAY.
&&
.AVIATION...
VFR CONDS THROUGH 23/16Z WITH LCL SHRA AND CIGS NR FL 040-050
DVLPG AFT 23/18Z WITH BOUNDARY INTERACTION AND WEST COAST SOURCE
PCPN MIGRATING EWD. BEST TIMING LOOKS LATER FOR PSBL MVFR AND/OR
ISOLD IFR CONDS IN SHRA/TS FM 23/20Z-24/01Z.
&&
.MARINE...
TODAY AND TONIGHT...FAVORABLE CONDS WITH GRADIENT WINDS 10KT OR
LESS MORNING INTO AFTERNOON. OFFSHORE MOVING PCPN AREAS PSBL AFTER
MID AFTN INTO EVENING WL PRODUCE LCLLY HIGHER WINDS AND SEAS NR
THE CST.
FRI-MON...NORTHERLY FLOW DAYBREAK FRIDAY MORNING QUICKLY VEERS NE
INTO THE AFTERNOON AND SOUTHEAST DURING THE OVERNIGHT HOURS. BRIEF
PUSH OF SPEEDS UP TO 15KTS WITH NE WIND SHIFT FRI
MORNING...OTHERWISE SPEEDS GENERALLY AROUND 10KTS.
INCREASING S/SW WINDS ON SATURDAY AS NEXT SYSTEM MOVES BY TO THE
NORTH WITH OVERALL SPEEDS AROUND 15KTS WITH 15-20KTS AT TIMES
TOWARDS LATE DAY OVER THE OFFSHORE WATERS. QUICK OFFSHORE MOVING
THUNDERSTORMS WILL BE A POSSIBILITY DURING THE AFTERNOON AND EVENING
HOURS.
WESTERLY WINDS WILL INCREASE 15-20 KNOTS ON SUNDAY WITH ANOTHER
ROUND OF SCATTERED SHOWERS/TSTMS MOVING QUICKLY EASTWARD ACROSS THE
WATERS.
FRONT DROPS INTO REGION ON MONDAY DISRUPTING STRONGER WEST FLOW WITH
WINDS VEERING NORTHWEST 5-10KTS...BECOMING VARIABLE INTO THE
AFTERNOON AS SURFACE HIGH NOSES IN FROM NORTHWEST.
SEAS 2-4FT THROUGH THE PERIOD WITH UP TO 5FT OFFSHORE AT TIMES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 86 66 82 68 / 30 20 10 10
MCO 89 69 88 69 / 40 30 10 10
MLB 86 70 84 72 / 50 40 10 10
VRB 86 68 84 71 / 50 40 20 10
LEE 86 69 87 71 / 40 20 10 10
SFB 87 69 86 70 / 40 30 10 10
ORL 88 70 87 70 / 40 30 10 10
FPR 86 68 84 69 / 50 40 20 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...PENDERGRAST
LONG TERM....MOSES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
107 AM CDT THU APR 23 2015
.UPDATE...826 PM CDT
FOR EVENING UPDATE...
LOWERED OVERNIGHT MINS A BIT ESPECIALLY IN THE ROCK/FOX RIVER
VALLEYS WEST OF CHICAGO. CLEARING SKIES...DECOUPLING WINDS AND VERY
DRY LOW LEVEL AIR IS EXPECTED TO RESULT IN SUB-FREEZING TEMPS
OVERNIGHT AWAY FROM THE URBAN CORE OF CHICAGO.
THE FORECAST AREA REMAINS UNDER THE INFLUENCE OF LARGE UPPER TROUGH
ACROSS EASTERN NORTH AMERICA...AND SURFACE LOW PRESSURE SLOWLY
MOVING FROM NORTHEAST OF THE GREAT LAKES TOWARD NEW ENGLAND AND
SOUTHERN QUEBEC. COLD AIR ON BLUSTERY WEST-NORTHWEST WINDS AND
EXTENSIVE CLOSED-CELL STRATOCU HAD EARLIER RESULTED IN AFTERNOON
TEMPERATURES STRUGGLING TO RISE OUT OF THE 40S IN MOST AREAS...WITH
EVEN A FEW SNOW FLURRIES NOTED THANKS TO A COMBINATION OF COLD AIR
ALOFT (-5C AT 850 MB PER 21Z AMDAR ASCENT SOUNDING FROM MDW)...STEEP
BOUNDARY LAYER LAPSE RATES AND LOW WET-BULB ZERO HEIGHTS OF 500-1000
FEET.
CURRENT IR SATELLITE IMAGERY SHOWS WESTERN/SOUTHERN PERIPHERY OF THE
CLOUD SHIELD ERODING WITH LOSS OF DIURNAL SURFACE-BASED INSTABILITY
THOUGH PATCHY CLOUD COVER WILL LIKELY CONTINUE TO AFFECT PARTS OF
NORTHEAST IL/NORTHWEST INDIANA INTO THE NIGHT BENEATH SHEARED AND
ELONGATED MID-LEVEL VORTICITY CHANNEL...THOUGH EVEN THOSE AREAS WILL
LIKELY SEE CLOUDS SCATTER OVERNIGHT PER RAP RH PROGS. AS INDICATED
ABOVE...CLEARING SKIES AND DECREASING WINDS COMBINED WITH DRY LOW
LEVEL AIR MASS (SURFACE DEW POINTS TEENS-LOW 20S OVER NORTH CENTRAL
IL) WILL ALLOW TEMPS TO SINK INTO THE MID 20S AWAY FROM THE CITY
OVERNIGHT...POSSIBLY EVEN LOWER 20S IN SOME SHELTERED SPOTS WHERE
WINDS ABLE TO DECOUPLE MORE STRONGLY IN MODEST SFC PRESSURE
GRADIENT. EXPECT DEW POINT TEMPS ACROSS EASTERN IA...CURRENTLY IN
THE SINGLE DIGITS IN SOME SPOTS...WILL COME UP A LITTLE WITH LOSS OF
DEEPER MIXING AND DECREASE IN WINDS. OTHERWISE...COULD SEE NEEDING
TO LOWER MIN TEMPS EVEN MORE ESPECIALLY WEST OF THE FOX RIVER.
RATZER
&&
.SHORT TERM...
315 PM CDT
THROUGH FRIDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH THE BELOW NORMAL TEMPS
TO PERSIST AND WITH WELL BELOW NORMAL TEMPS AROUND OR BELOW
FREEZING TONIGHT AND THURSDAY NIGHT...WITH A FREEZE WARNING IN
EFFECT FOR THE ENTIRE CWA TONIGHT.
WITH THE LARGE UPPER LEVEL LOW STILL SPINNING JUST NORTHEAST OF
THE GREAT LAKES REGION...FAIRLY ENERGETIC FLOW CONTINUES TO MOVE
OVERHEAD. THIS COINCIDING WITH STEEP LOW LEVEL LAPSE RATES ACROSS
NORTHERN ILLINOIS AND NORTHWEST INDIANA...ISOLATED SHOWERY
ACTIVITY IS STILL ONGOING AT THIS TIME. THIS WILL LIKELY CONTINUE
OVER THE NEXT COUPLE OF HOURS...BEFORE DIMINISHING BY EARLY THIS
EVENING. PRECIP TYPE WILL BE EITHER FLURRIES OR SPRINKLES DURING
THIS TIME. DESPITE LOW TO MID 40 SURFACE TEMPS IN PLACE...VERY
COLD AIR ALOFT AND THESE STEEP LAPSE RATES WILL CONTINUE TO
SUPPORT THE DEVELOPMENT OF FLURRIES AT TIMES. EXTENSIVE CLOUD
COVER STILL IN PLACE THIS AFTERNOON WILL DIMINISH THROUGH THE
EARLY EVENING...WITH CLEARING SKIES EXPECTED THROUGH THE REMAINDER
OF THE EVENING AND OVERNIGHT. WITH THE VERY COLD AIRMASS IN PLACE
AND CLEARING SKIES...VERY CHILLY CONDITIONS WILL OCCUR OVER THE
ENTIRE CWA TONIGHT. HAVE LOWERED TEMPS A COUPLE OF DEGREES IN MOST
PLACES...WITH THE UPPER 20S TO AROUND 30 LIKELY FOR MOST LOCATIONS
AND LOWER 30S FOR THE CHICAGO METRO AREA. WITH THESE EXPECTED
TEMPS...HAVE ISSUED A FREEZE WARNING FOR THE ENTIRE CWA INCLUDING
COOK...FOR AREAS OUTSIDE OF THE IMMEDIATE CITY. THIS WILL START
JUST AFTER THE MIDNIGHT TIME FRAME...GOING THROUGH 13Z THURSDAY.
HAVE MADE MENTION OF PATCHY FROST TONIGHT BUT WITH THE WINDS
STAYING SLIGHTLY ELEVATED...WIDESPREAD FROST DOES NOT APPEAR
LIKELY AT THIS TIME. ANOTHER COLD NIGHT IN THE LOWER 30S IS LIKELY
THURSDAY NIGHT AND WITH HIGH PRESSURE AND LIGHT TO CALM WINDS
SETTLING IN...WIDESPREAD FROST APPEARS MORE LIKELY DURING THIS
TIME.
RODRIGUEZ
&&
.LONG TERM...
315 PM CDT
FRIDAY NIGHT THROUGH WEDNESDAY...
PRECIP CHANCES WILL BEGIN TO INCREASE BY THE START OF THE WEEKEND
AS MID/UPPER LEVEL TROUGH AND ASSOCIATED SURFACE LOW APPROACH FROM
THE CENTRAL PLAINS. THE ARRIVAL OF THIS SYSTEM AND BEST FORCING
APPEAR TO ARRIVE DURING THE DAY SATURDAY AND LIKELY CONTINUE INTO
THE EVENING. AT THIS TIME IT DOES LOOK LIKE THE ENTIRE CWA WILL
OBSERVE RAIN...BUT SOME GUIDANCE IS HINTING AT A MORE SOUTHERLY
TRACK. SO DID RAISE POPS ON SATURDAY BUT KEPT THE HIGHEST ACROSS
THE SOUTHERN HALF OF THE CWA. WITH THE DEPARTURE OF THIS SYSTEM
AND RAIN...CONDITIONS DRY AND LOOK TO REMAIN DRY THROUGH EARLY
NEXT WEEK...WITH A TREND TOWARDS MORE NORMAL TEMPS.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* GUSTY WEST/NORTHWEST WINDS THURSDAY.
KMD
//DISCUSSION...UPDATED 06Z...
STILL A PRESSURE GRADIENT OVER THE AREA SO SOME LIGHT WNW WINDS
REMAIN IN PLACE. WINDS WILL INCREASE AGAIN THURSDAY MORNING BUT WILL
NOT BE AS STRONG AS WEDNESDAY WITH GUSTS EXPECTED IN THE UPPER
TEENS TO NEAR 20KT RANGE. A LAKE BREEZE IS POSSIBLE...BUT AT THIS
TIME CONFIDENCE ONLY EXISTS IN THE LAKE BREEZE MAKING IT TO THE
NEAR SHORELINE AREAS. WINDS WILL QUICKLY DIMINISH THURSDAY EVENING
AS HIGH PRESSURE MOVES ACROSS THE AREA. KMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH FOR WINDS THRU THE PERIOD.
KMD
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...SLIGHT CHANCE EVENING SHRA. VFR. EAST WINDS.
* SATURDAY...SHRA LIKELY. IFR LIKELY. STRONG/GUSTY NORTHEAST WINDS.
* SUNDAY THRU TUESDAY...DRY/VFR. NORTHEAST WINDS.
&&
.MARINE...
130 PM CDT
UNSEASONABLY STRONG LOW PRESSURE NEAR JAMES BAY CONTINUES TO
RESULT IN FAIRLY STRONG NORTHWEST WINDS ACROSS THE LAKE AND THESE
WINDS SHOULD CONTINUE INTO TONIGHT BEFORE HIGH PRESSURE OVER THE
PLAINS BEGINS TO MIGRATE EASTWARD TOWARD THE MISSISSIPPI VALLEY. A
COUPLE OF DAYS OF FAIRLY LIGHT WINDS DOMINATED BY LAND/LAKE BREEZE
CIRCULATIONS SHOULD ENSUE THURSDAY AND FRIDAY BEFORE ANOTHER
FAIRLY STRONG LOW PRESSURE CAUSES WINDS TO RAMP UP AGAIN FRIDAY
NIGHT AND ESPECIALLY SATURDAY. THIS LOW WILL PASS WELL SOUTH OF
THE LAKE SETTING THE STAGE FOR STRONG NORTHEASTERLY
WINDS...ESPECIALLY SOUTHERN PORTIONS OF THE LAKE WHERE WINDS COULD
END UP NOT TERRIBLY FAR FOR GALE FORCE FOR A TIME SATURDAY
AFTERNOON SHOULD THE STRONGER MODELS VERIFY. NORTHERLY WINDS WILL
BEGIN TO EASE SUNDAY WITH GRADIENT BECOMING FAIRLY WEAK HEADING
INTO NEXT WEEK WITH WINDS ONCE AGAIN PRIMARILY DOMINATED BY
LAKE/LAND BREEZE CIRCULATION.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FREEZE WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 8 AM THURSDAY.
IN...FREEZE WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 AM
THURSDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1130 PM CDT WED APR 22 2015
.SYNOPSIS...
ISSUED AT 305 PM CDT WED APR 22 2015
THE MIDWEST REMAINS UNDER THE INFLUENCE OF A STACKED LOW PRESSURE
SYSTEM CENTERED OVER ONTARIO. THE MAIN SENSIBLE WEATHER IMPACT
ACROSS E IOWA/W ILLINOIS TODAY HAS BEEN THE STRONG/GUSTY NW WINDS
BETWEEN 30-40 MPH. SFC DEWPOINTS ARE VERY LOW...HOVERING IN THE
TEENS. AT 3 PM THE RH AT THE DAVENPORT AIRPORT WAS DOWN TO 18
PERCENT.
&&
.UPDATE...
ISSUED AT 812 PM CDT WED APR 22 2015
CURRENT SURFACE ANALYSIS SHOWS DEWPOINT TEMPERATURES IN THE SINGLE
DIGITS UPSTREAM IN MN. 23Z RAP HAS THESE VALUES ADVECT ACROSS THE
AREA TONIGHT. CURRENT DEWPOINT TEMPS ARE 5 TO 10 DEGREES LOWER
THAN 5 HOURS AGO. WITH THE CLEAR SKIES AND WINDS
WEAKENING...TONIGHT LOOKS LIKE A NIGHT WHERE THE BOTTOM COULD DROP
OUT. THE NEXT COUPLE OF HOURS WILL TELL A LOT ABOUT HOW COLD WE
COULD GET TONIGHT. AS SUCH...LOWERED LOWS BY 3 TO 4 DEGREES TO
HEDGE TOWARDS LOWER TEMPS. IF THE DEWPOINTS DONT CHANGE MUCH WHEN
WE DECOUPLE THEN MAY NEED TO GO EVEN LOWER. WILL MONITOR AND
DECIDE WHAT TO DO AROUND 10PM. HAVE INCLUDED THE RECORD LOWS FOR
TONIGHT AS IT COULD BE POSSIBLE THAT WE COULD SEE TEMPS CLOSE TO
THEM TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 305 PM CDT WED APR 22 2015
THIS EVENING AND TONIGHT...SFC PRESSURE GRADIENT WILL WEAKEN
DRAMATICALLY AND ATMOSPHERE WILL DECOUPLE TO SOME EXTENT. THE SFC
HIGH PRESSURE AXIS WILL STAY WEST OF THE AREA ACROSS CENTRAL
IOWA...SO WINDS AROUND 5 KTS ARE FORECAST THROUGH THE NIGHT. CLEAR
SKIES AND VERY DRY AIR WILL SET THE STAGE FOR WELL BELOW NORMAL LOW
TEMPS IN THE MID 20S TO LOWER 30S.
WITH VEGETATION GREEN-UP WELL UNDERWAY AND LOCAL KNOWLEDGE FROM IOWA
STATE UNIVERSITY THAT FRUIT TREES ARE NOW SUSCEPTIBLE TO TEMPS IN
THE UPPER 20S...WILL ISSUE A FREEZE WARNING FOR THE ENTIRE AREA.
STARTED THE WARNING AT 2 AM CDT OVER NORTHERN TWO-THIRDS OF THE
FORECAST AREA WHERE MID TO UPPER 20S ARE FORECAST...AND AT 4 AM
OVER THE SOUTHERN THIRD WHERE UPPER 20S TO LOWER 30S ARE FORECAST.
BOTH WARNING SEGMENTS WILL EXPIRE AT 8 AM CDT THURSDAY MORNING.
THURSDAY...FINALLY MUCH LIGHTER WINDS...GENERALLY UNDER 15 MPH OUT
OF THE NW. OTHERWISE MOSTLY CLEAR SKIES WILL HELP TEMPS REACH TO
NEAR 60 F ON AVG.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 305 PM CDT WED APR 22 2015
ANOTHER COLD NIGHT WILL BEGIN THE EXTENDED...AS SURFACE HIGH
PRESSURE REMAINS OVER THE AREA. WARM ADVECTION ALOFT WILL RESULT IN
CIRRUS AND POSSIBLE MID CLOUDS AFTER LATE EVENING...THUS...LOWS
SHOULD OCCUR AROUND MIDNIGHT...FOLLOWED BY STEADY OR RISING
TEMPERATURES. LOWS MAY DIP NEAR 32 IN THE EAST...BUT SHOULD HOLD IN
THE UPPER 30S TO AROUND 40 IN THE WEST 1/3.
LOOKING AT FRIDAY THROUGH THE WEEKEND...MODELS CONTINUE TO SHOW A
WINTER LIKE SYSTEM AFFECTING THE REGION...WITH A CLOSED MID LEVEL
LOW...OVER IOWA...AND SURFACE LOW IN MISSOURI. THIS SYSTEM SHOULD
PRODUCE WIDESPREAD STRATIFORM RAINS...MUCH LIKE A SNOW
EVENT...WOULD...ALONG WITH COLD TEMPERATURES AND EAST WINDS.
THUS...A DEFORMATION ZONE OF RAIN WILL LIKELY IMPACT OUR ENTIRE
CWA...BUT MOST CERTAINLY IN THE SOUTH 1/2. POPS ARE FORECAST
CATEGORICAL FRIDAY NIGHT...AND SATURDAY MORNING IN THE SOUTH TO
ACCOUNT FOR WIDESPREAD LIGHT TO MODERATE RAIN.
RAIN...EAST WINDS...AND CLOUDS WILL KEEP SATURDAY COOL...BUT ENOUGH
OF FRIDAY SHOULD SEE FILTERED SUN TO GET HIGHS BACK TO THE MID TO
UPPER 50S. SATURDAY WILL BE HELD TO THE UPPER 40S TO LOWER 50S...AND
THAT TOO COULD BE OPTIMISTIC IF THE RAINS MATERIALIZE AS PERSISTENT
AS THE GFS AND ECMWF BOTH SHOW.
FOLLOWING THIS WEEKEND RAIN SYSTEM...MODELS ARE QUICKLY SHOWING A
RETURN TO NORTHWEST FLOW ON THE WESTERN FLANK OF THE DOMINANT
EASTERN CONUS UPPER LOW. THIS COLDER THAN NORMAL PATTERN MAY STAY IN
PLACE THROUGH THE EARLY DAYS OF MAY. WHILE SOME RAIN SHOWERS WILL BE
POSSIBLE IN CLIPPER TYPE FORCING...THE MAIN IMPACTS WILL MOST
CERTAINLY BE MORE BREEZY...DEEPLY MIXED DAYS...WITH HIGHS GENERALLY
BELOW NORMAL.
ERVIN
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1127 PM CDT WED APR 22 2015
VFR CONDITIONS WILL DOMINATE THE PERIOD WITH LIGHTER WINDS TODAY
ACROSS THE AREA. SOME VERY ISOLATED CUMULUS CLOUDS COULD
DEVELOP...BUT NOTHING IS EXPECTED TO AFFECT VSBYS OR CEILINGS AT
THE TAF SITES. ANOTHER SYSTEM TO OUR WEST WILL LEAD THE WINDS TO
SHIFT TO THE EAST LATE IN THE PERIOD. WINDS WILL BE LIGHT AFTER
SUNSET TODAY AND MOST LIKELY FROM THE EAST AT ALL SITES.
&&
.CLIMATE...
ISSUED AT 812 PM CDT WED APR 22 2015
RECORD LOWS FOR APR 23...
BURLINGTON ...24...1910
CEDAR RAPIDS...20...1927
DUBUQUE...22...1910
MOLINE...22...1910
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FREEZE WARNING UNTIL 8 AM CDT THURSDAY FOR BENTON-BUCHANAN-CEDAR-
CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-JACKSON-
JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-MUSCATINE-
SCOTT-VAN BUREN-WASHINGTON.
IL...FREEZE WARNING UNTIL 8 AM CDT THURSDAY FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...FREEZE WARNING UNTIL 8 AM CDT THURSDAY FOR CLARK-SCOTLAND.
&&
$$
UPDATE...GIBBS
SYNOPSIS...UTTECH
SHORT TERM...UTTECH
LONG TERM...ERVIN
AVIATION...GIBBS
CLIMATE...GIBBS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1127 PM MDT WED APR 22 2015
.UPDATE...
ISSUED AT 952 PM MDT WED APR 22 2015
MODELS COMING INTO FAIRLY GOOD AGREEMENT WITH THE LIKELIHOOD OF
FOG DEVELOPING OVER KIT CARSON/CHEYENNE COUNTIES LATE TONIGHT AND
EARLY THURSDAY MORNING. CURRENTLY THINKING VISIBILITIES OF A MILE
OR SO ARE LIKELY...WITH SOME LOCATIONS POSSIBLY DROPPING CLOSE TO
A QUARTER MILE.
TOOK OUT THE RAINFALL CHANCES FOR THE EVENING SINCE THE STORMS
JUST WEST OF THE AREA HAVE DIED. STILL THINKING SOME DRIZZLE/LIGHT
RAINFALL IS POSSIBLE LATE TONIGHT AND EARLY TOMORROW MORNING WITH
THE FOG.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 225 PM MDT WED APR 22 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS
NORTHERN AND SOUTHERN JET STREAMS SPLIT AROUND OUR CWA...WITH WEAK
RIDGING EXTENDING FROM THE SOUTHERN PLAINS AND ACROSS THE CENTRAL
ROCKIES. PACIFIC MOISTURE PLUME IS UNDERCUTTING UPPER RIDGE WITH
WEAK SHORTWAVE TROUGHS ROTATING NORTH AND EAST THROUGH THE
SOUTHERLY STORM TRACK. AT THE SURFACE A STATIONARY FRONT HAS
SLOWLY BEGUN THE PROCESS OF MOVING EAST WITH RADAR SHOWING
CONVECTION DEVELOPING IN THE WEAKLY UNSTABLE AIR MASS BEHIND THIS
FEATURE OVER THE HIGHER TERRAIN IN COLORADO.
THIS AFTERNOON TONIGHT...INITIAL CONCERN IS ON COVERAGE AND
PROGRESS OF THUNDERSTORM ACTIVITY IN COLORADO TOWARDS OUR CWA.
GUIDANCE SHOWS INCREASING INSTABILITY IN OUR WESTERN CWA...WHICH
COULD FAVOR THIS ACTIVITY MAKING AS FAR EAST AS THE CO/KS STATE
LINE. WHILE MOST OF THIS ACTIVITY WILL BE TIED TO DAYTIME
HEATING...WAA OVERNIGHT AND NOSE OF LLJ COULD SUPPORT
THUNDERSTORM LINGERING LATE THIS EVENING...OR SHOWERS AFTER
MIDNIGHT AS INSTABILITY WANES. MID LEVELS ARE NOT PARTICULARLY
MOIST AND DESPITE VERY GOOD OVERNIGHT MOISTURE ADVECTION WITHIN
THE BOUNDARY LAYER CAP ABOVE THIS WOULD LIKELY LIMIT CONVECTIVE
POTENTIAL FOR ANY NON ELEVATED PARCELS. I KEPT SLIGHT CHANCE OF
THUNDERSTORMS IN THE EVENING WITH SHOWERS LINGERING AFTER
MIDNIGHT THROUGH THURSDAY MORNING. CONSIDERING THE NEAR SATURATED
BOUNDARY LAYER THE PRECIP SIGNAL IN GUIDANCE MAY ACTUALLY BE
DRIZZLE/FOG.
THURSDAY...NAM SOUNDINGS INDICATE POTENTIAL FOR LINGERING
STRATUS/DRIZZLE DURING THE DAY...HOWEVER OVERALL PATTERN SHOULD
SUPPORT CLEARING SKIES FROM THE WEST WITH WARMER CONDITIONS ACROSS
EASTERN COLORADO. A STRONGER SHORTWAVE TROUGH WILL BEGIN TO MOVE
INTO THE CWA FROM THE WEST WITH INCREASING THUNDERSTORM CHANCES
ONCE AGAIN IN EASTERN COLORADO WHERE BETTER INSTABILITY IS
ADVERTISED ALONG WITH STRONGER LIFT. CONFIDENCE WAS HIGH ENOUGH
TO KEEP CHANCE POPS IN PLACE LATE THURSDAY AFTERNOON. HIGH
TEMPERATURES THURSDAY WILL BE TRICKY AND HIGHLY DEPENDENT ON
STRATUS CLEARING. HIGHS NEAR 70F (MAINLY IN THE WEST) ARE POSSIBLE
WHERE BEST CHANCE FOR CLEAR SKIES IS CURRENTLY ANTICIPATED.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 232 PM MDT WED APR 22 2015
THE UPPER RIDGE AXIS EXTENDING FROM THE GULF OF MEXICO THROUGH
THE NORTHERN HIGH PLAINS FLATTENS SOMEWHAT LATE THURSDAY INTO
THURSDAY NIGHT AS A SHORT WAVE TROUGH MOVES OUT OF THE SOUTHWEST
U.S. AND OVER THE CENTRAL PLAINS THURSDAY NIGHT. THE LEE SURFACE
TROUGH ALONG THE FRONT RANGE THAT DEEPENS IN RESPONSE TO THE UPPER
SHORT WAVE TROUGH HAS GOOD SOUTHEASTERLY FLOW AHEAD OF IT THAT
WILL BRING AMPLE GULF MOISTURE INTO THE REGION. SCATTERED STRONG
THUNDERSTORMS ARE POSSIBLE ACROSS THE FORECAST AREA THURSDAY NIGHT
AS A RESULT
THE MAIN UPPER TROUGH AXIS BEGINS TO LIFT OUT ACROSS THE
4-CORNERS REGION AND INTO THE CENTRAL AND SOUTHERN HIGH PLAINS
REGION BY FRIDAY AFTERNOON...WITH THE CENTROID OF THE TROUGH
MOVING OVER E CO/NW KS. DEWPOINTS IN THE 40S ACROSS THE AREA ON
THURSDAY AND THURSDAY NIGHT WILL INCREASE INTO THE LOWER 50S
ACROSS MAINLY THE EASTERN PORTION OF THE FORECAST AREA WHILE DRYER
AIR MOVES INTO THE WEST AS THE TROUGH MOVES EAST AND FORMS A
CLOSED LOW THAT MOVES ACROSS SOUTHERN KANSAS FRIDAY EVENING. WITH
AN INSTABILITY AXIS PRESENT OVER CENTRAL KANSAS...IT IS POSSIBLE
THE FORECAST AREA COULD SEE SOME STRONG TO SEVERE THUNDERSTORMS
MAINLY ACROSS THE FAR EASTERN SECTIONS THAT WILL BECOME MORE
WIDESPREAD AND STRONGER OVERNIGHT AS THEY MOVE FURTHER TO THE
EAST.
SHORT WAVE RIDGING IS EXPECTED BETWEEN THE EXITING TROUGH AS IT
LIFTS OUT OF THE REGION AND THE NEXT UPPER TROUGH THAT STARTS TO
DEEPEN OVER THE INTERMOUNTAIN WEST BETWEEN SATURDAY AND SATURDAY
EVENING. MODEL SOLUTIONS HAVE A LOW CENTER CONSOLIDATING AND
MOVING QUICKLY ACROSS NEW MEXICO SUNDAY EVENING. THEN AS MODEL
SOLUTIONS BEGIN TO DIVERGE TO A GREATER DEGREE...THE LOW SLOWS AND
ENDS UP SOMEWHERE OVER E OKLAHOMA/E TEXAS BY TUESDAY MORNING AS A
BLOCKING HIGH AMPLIFIES OVER THE WESTERN UNITED SATES. THAT RIDGE
MOVES OVER THE ROCKIES AND HIGH PLAINS REGION BY WEDNESDAY
EVENING. THE WEEKEND AND FIRST PART OF NEXT WEEK WILL REMAIN
UNSETTLED WITH SCATTERED THUNDERSTORMS POSSIBLE ACROSS THE AREA AS
THE LOW MOVES ACROSS THE SOUTHERN PLAINS. DRYER AND WARMER
CONDITIONS ARE ANTICIPATED BY MID-WEEK AS SURFACE HIGH PRESSURE
AND THE RIDGE ALOFT MOVE OVER THE HIGH PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1119 PM MDT WED APR 22 2015
MVFR TO IFR CONDITIONS FORECAST FOR THE 6Z TAFS. LOW STRATUS OVER
THE TX PANHANDLE IS FORECAST TO MOVE NORTH AND EXPAND IN COVERAGE
THROUGH THE REST OF THE NIGHT. AM THINKING THE VERY LOW STRATUS
WILL MOVE OVER KGLD FROM THE WEST...WHILE THE MVFR CEILINGS MOVE
UP FROM THE SOUTH. KMCK WILL BE IMPACTED BY THE LOWER CEILINGS A
FEW HOURS AFTER KGLD. EXPECT THE LOWEST CEILING DURING THE EARLY
MORNING. AFTER THAT THE WARMER TEMPERATURES SHOULD ALLOW CEILINGS
TO LIFT SOME IN THE LATE MORNING/AFTERNOON. THURSDAY EVENING
CEILINGS WILL AGAIN LOWER...REACHING IFR AT BOTH SITES BY
MIDNIGHT.
ASIDE FROM THE LOW CEILINGS FOG IS EXPECTED TO DEVELOP WEST OF
KGLD. CURRENTLY AM NOT ANTICIPATING ANY FOG TO MOVE OVER THE SITE.
LLWS WILL CONTINUE THROUGH THE NIGHT FOR BOTH SITES...COMING TO AN
END BY MID MORNING. BASED ON THE STRENGTH OF THE LOW LEVEL JET
THURSDAY EVENING...WOULD EXPECT LLWS TO RETURN TO BOTH SITES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1139 PM CDT WED APR 22 2015
.UPDATE...
ISSUED AT 1139 PM CDT WED APR 22 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 00Z TAF ISSUANCE.
UPDATE ISSUED AT 918 PM CDT WED APR 22 2015
NO CHANGE TO THE CURRENT FROST ADVISORY...ALTHOUGH...MIGHT SEE A
LITTLE COLDER TEMPERATURES OVER MCLEAN AND NORTHEAST MULHENBURG
COUNTIES IN WEST KENTUCKY. WILL NEED TO MONITOR OVERNIGHT.
THE NAM-WRF HIGH RESOLUTION GUIDANCE FAMILIES AND RAP GUIDANCE
APPEAR TO HAVE THE BEST HANDLE ON THE SENSIBLE WEATHER ELEMENTS
OVERNIGHT. THE VAST MAJORITY OF THE COLDER AND AND FROST POTENTIAL
SHOULD REMAIN ALONG AND NORTH OF THE CRAWLEY`S RIDGE/SHAWNEE HILLS
REGION.
MAIN ADJUSTMENT WAS TO SLOW THE DEGREE AND INTENSITY OF THE
RETURNING MID-LEVEL CLOUDS FROM ARKANSAS AND OKLAHOMA INTO
MISSOURI AND KENTUCKY OVERNIGHT. THIS SHOULD REDUCE ANY
SIGNIFICANT DISRUPTION IN RADIATIVE COOLING OVERNIGHT.
UPDATE ISSUED AT 632 PM CDT WED APR 22 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 00Z TAF ISSUANCE.
UPDATE ISSUED AT 438 PM CDT WED APR 22 2015
SORRY FOR THE LATE NOTICE.
TALKS WITH A STATE AGRONOMIST IN PARTS OF THE AREA EXPECTED TO
SEE PATCHY FROST AND TEMPERATURES IN THE 30S OVERNIGHT
NECESSITATED THE ISSUANCE OF A FROST ADVISORY FROM 2 AM TO 8 AM
CDT THURSDAY MORNING. MAIN CONCERN IS FOR PRIVATE AND COMMERCIAL
STRAWBERRY GROWERS...AS WELL AS PRIVATE AND COMMERCIAL PLANT
GROWERS WITH PLANTS VERY SENSITIVE TO FROST DEVELOPMENT.
FROST ADVISORY AREA OUTLINED IS ALONG AND NORTH OF A PIEDMONT
MISSOURI...VIENNA ILLINOIS...CALHOUN KENTUCKY LINE AT THIS TIME.
MAIN LIMITING FACTOR FOR COVERAGE IS THE AMOUNT OF EVAPORATION AT
THE GROUND SURFACE FROM THE INFLUX OF DRY AIR TODAY. HOWEVER...THERE
IS STILL ENOUGH ANTECEDENT MOISTURE FROM EARLIER RAIN
EVENTS...INCLUDING THE ONE LAST NIGHT TO ERR ON THE SIDE OF CAUTION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 116 PM CDT WED APR 22 2015
HIGH PRESSURE SHOULD RESULT IN QUIET WEATHER TONIGHT. MOS
CONTINUES TO SUGGEST MID TO UPPER 30S I-64 CORRIDOR OR JUST SOUTH.
PATCHY FROST WAS ALREADY IN PLACE. WILL MAINTAIN THIS THOUGH IT
LOOKS MARGINAL ESPECIALLY WITH FORECAST TEMP / DEW POINT SPREADS
WHAT THEY ARE. WILL MAINTAIN DRY WEATHER THURSDAY INTO THURSDAY
EVENING AS HIGH PRESSURE SLOWLY MOVES EAST. THE GFS AND NAM ARE IN
AGREEMENT THAT SOME LIGHT SHOWER/THUNDERSHOWER ACTIVITY COULD MAKE
IT INTO SEMO LATE THURSDAY NIGHT...WITH CHANCES INTO FRIDAY AS
WELL GRADUALLY SHIFTING EAST. CHANCES OF CONVECTION INCREASE
FRIDAY NIGHT AS THE MODELS CONTINUE TO ADVERTISE AN UPPER TROF AND
ASSOCIATED SURFACE LOW MOVING FROM THE PLAINS TOWARD THE UPPER
MIDWEST. USED A BLEND OF MOS GUIDANCE FOR TEMPS. MODEL PREFERENCE
WAS A GFS/NAM BLEND.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 116 PM CDT WED APR 22 2015
MEDIUM CONFIDENCE THROUGH THE WEEKEND WITH LOW CONFIDENCE WITH PATH
OF THE SYSTEM MID WEEK NEXT WEEK. LATEST MODELS RUNS INDICATE THE
SYSTEM NEXT WEEK WILL HIT US WHILE OTHERS SHOW A MORE SOUTHERLY PATH.
MAIN CONCERN WITH EXTENDED WILL BE WITH STRONG OR POSSIBLY SEVERE
STORMS SATURDAY AFTERNOON. THE ONE LIMITING FACTOR WILL BE AVAILABLE
MOISTURE WITH MOST MODELS NEAR ONE INCH OR LESS PW OR NEAR THE 75TH
PERCENTILE. OTHERWISE WINDS SHOW A GOOD SPEED SHEAR NOT SO MUCH ON
WITH DIRECTIONAL SHEAR I.E SRH <10M2/S2. HOWEVER WITH 850MB-500MB
LAPSE RATES 7+/KM AND MU CAPES BETWEEN 3K AND 4K ANY THING THAT DOES
GET GOING HAS THE POTENTIAL FOR SEVERE WIND AND WITH THE FREEZING
LEVEL NEAR 10K COULD NOT RULE OUT HAIL EITHER. CONSIDERING THE
SIGNIFICANT INSTABILITY IT WILL NOT TAKE AS MUCH SHEAR TO GET SOME
ROTATION.
OTHERWISE WEAK RIDGE WILL BUILD IN SUNDAY WITH THE NEXT SYSTEM ON
ITS HEELS. THE 00Z WED EU TAKES THIS ENERGY SOUTH OF THE FA THROUGH
THE LOWER TN VALLEY. THE 12Z EU TAKES BRINGS IT A LITTLE FARTHER
NORTH THROUGH OUR CWA TUE AND EXITS WED EARLY. THE CANADIAN IS MUCH
SLOWER WITH THIS SYSTEM. THE 06Z WED DGEX BRINGS THE CORE OF THE
UPPER LOW RIGHT THROUGH OUR CWA. SOME ENSEMBLES THE GEFS GEPS AND
EPS TAKE THE BRUNT OF THE SYSTEM SOUTH BUT STILL BRINGS PRECIP OVER
THE AREA. THUS WILL ALLOW EXTENDED INIT AND COLLABORATION CALCULATE
JUST WHAT POPS TO INCLUDE.
WILL START OUT ABOVE NORMAL TEMPS FOR THE WEEKEND AND COOL TO NEAR
NORMAL NEXT WEEK AS NEXT SYSTEM MOVES INTO THE REGION.
&&
.AVIATION...
ISSUED AT 1139 PM CDT WED APR 22 2015
VFR FORECAST TONIGHT. SURFACE HIGH PRESSURE IS SETTLING OVER THE
REGION...BUT MIXING WILL RESULT IN THE POTENTIAL FOR GUSTS INTO
THE TEENS AT KEVV AND KOWB THURSDAY. SOME MID-LEVEL CEILINGS WILL
BE POSSIBLE OVERNIGHT AND INTO THE MORNING AT KCGI AND KPAH...BUT
OTHERWISE SKIES WILL BE CLEAR.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...FROST ADVISORY UNTIL 8 AM CDT THURSDAY FOR ILZ075>078-080>091.
MO...FROST ADVISORY UNTIL 8 AM CDT THURSDAY FOR MOZ076-086-087-100.
IN...FROST ADVISORY UNTIL 8 AM CDT THURSDAY FOR INZ081-082-085>088.
KY...FROST ADVISORY UNTIL 8 AM CDT THURSDAY FOR KYZ014-015-018-019.
&&
$$
UPDATE...DRS
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
319 AM EDT THU APR 23 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 344 PM EDT WED APR 22 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED UPR LO/
POCKET OF H5 TEMPS NEAR -30C CENTERED OVER ONTARIO TO THE SW OF
JAMES BAY DOWNSTREAM OF HI AMPLITUDE RDG OVER THE ROCKIES. DEEP
MOIST CYC NW FLOW ARND THE CLOSED LO CONTINUES TO IMPACT UPR MI...
DRAWING UNSEASONABLY CHILLY AIR /H85 TEMPS AS LO AS -12 TO -14C THAT
ARE SUFFICIENTLY COLD FOR LES/ INTO THE AREA. THE RESULT HAS BEEN
NMRS SN SHOWERS THAT HAVE BEEN EXACERBATED OVER LAND WITH DAYTIME
HEATING EVEN IN THE ABSENCE OF SGNFT LARGER SCALE FORCING/DEEP LYR
QVECTOR CNVGC.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/SN AMOUNTS
ESPECIALLY TNGT AS UPR LO DRIFTS SLOWLY TO THE E. TEMPS WL REMAIN
BLO NORMAL THRU THU.
TNGT...UPR LO IS FCST TO DRIFT SLOWLY TO THE E...ALLOWING FOR SLOWLY
RISING H5 HGT/WEAKENING LLVL CYC FLOW. ALTHOUGH SOME GENERAL LARGER
SCALE SUBSIDENCE IS FCST TO DOMINATE...H85 TEMPS REMAINING AS LO AS
ABOUT -13C IN THE PRESENCE OF SOME LINGERNING DEEP MSTR/NOCTURNAL
COOLING WL BE SUFFICIENT TO MAINTAIN LES IN THE FAVORED NW WIND SN
BELTS OVER THE ERN CWA. EXPECT UP TO A COUPLE INCHES OF SN ACCUM IN
THIS AREA. OVER THE W...WARMING H85 TEMPS TO ARND -10C/ LOWERING
SUBSIDENCE INVRN UNDER THE GREATER HGT RISES SHOULD TEND TO CAUSE
THE SN SHOWERS TO DIMINISH IN THAT AREA. HOWEVER...THE PERSISTENT
UPSLOPE NW FLOW AND LINGERING UPSLOPE FLOW WL ALLOW FOR AT LEAST
SOME SCT SN SHOWERS EVEN IN THAT AREA.
THU...PERSISTENT HGT RISES AND SUBSIDENCE/TENDENCY FOR THE LLVL FLOW
TO BECOME MORE ACYC AS WELL AS SOME LLVL DRYING IN THE PRESENCE OF
DAYTIME HEATING WL DIMINISH THE SN SHOWERS W-E. FCST SDNGS INDICATE
THERE WL BE SOME SUNSHINE IN THE AFTN AS WELL WITH HI PRES RDG FCST
TO BLD INTO THE WRN CWA LATER IN THE DAY. TEMPS SHOULD REBOUND INTO
THE 40S OVER THE INTERIOR W AND SCENTRAL AWAY FM LK MODERATION WITH
H85 TEMPS PROGGED TO REACH NEAR -6C ALONG THE WI BORDER BY 00Z FRI.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 319 AM EDT THU APR 23 2015
NAM SHOWS A 500 MB TROUGH OVER THE ROCKIES AND ANOTHER OVER NEW
ENGLAND 12Z FRI. THE TROUGH OVER THE ROCKIES MOVES INTO THE CENTRAL
PLAINS ON FRI AND GETS ABSORBED INTO THE TROUGH IN NEW ENGLAND ON
SAT. MOST OF THE PCPN WITH THIS SYSTEM STAYS TO THE WEST AND SOUTH
OF THE AREA...BUT DID PUT SOME SLIGHT CHANCE POPS IN FOR THE FAR
WEST FRI NIGHT. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE
GOING FORECAST FOR TEMPERATURES OR WEATHER AND KEPT IT DRY FOR LATE
FRI NIGHT INTO SAT NIGHT. QUIET AND COOL WEATHER FOR THIS FORECAST
PERIOD.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE
EASTERN U.S. WITH A DEEPER TROUGH IN THE ROCKIES AND A RIDGE OVER
THE PLAINS 12Z SUN. UPPER PATTERN CHANGES LITTLE FOR 12Z MON. A
RIDGE BUILDS INTO THE WESTERN U.S. 12Z TUE. A TROUGH IS POISED TO
DROP INTO THE UPPER GREAT LAKES 12Z TUE WHICH DOES MOVE INTO THE
AREA ON WED. LOOKS DRY FOR SUN AND MON WITH A SLOW WARMING
TREND...BUT TEMPERATURES WILL REMAIN BELOW NORMAL FOR THIS FORECAST
PERIOD. HAVE SOME SLIGHT CHANCE POPS IN FOR THE WEST HALF OF THE
AREA MON NIGHT THROUGH WED AS A SFC FRONT AND UPPER TROUGH ARE
NEARBY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 120 AM EDT THU APR 23 2015
EXPECT PREDOMINANT MVFR CONDITIONS WITH COLD...MOIST NW FLOW OF AIR
AROUND DEEP LOW PRES IN SE CANADA OVERNIGHT EVEN THROUGH SOME
LINGERING SNOW SHOWERS COULD REDUCE VSBY BRIEFLY TO IFR AT IWD/CMX.
IMPROVEMENT TO VFR CONDITIONS IS EXPECTED THURSDAY MORNING WITH THE
CLOSER APPROACH OF SFC HIGH PRES AND DRIER AIR UNDER LARGE SCALE
SUBSIDENCE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT WED APR 22 2015
A FEW NW WINDS GUSTING TO 30 TO NEAR 35KT GALES WILL REMAIN POSSIBLE
OVER N AND CENTRAL LAKE SUPERIOR THIS EVENING. LOW PRESSURE ACROSS
JAMES BAY WILL FILL LATE TONIGHT AND THURSDAY. THE TROUGH ACROSS
LAKE SUPERIOR THIS MORNING...EXTENDING FROM THE JAMES BAY LOW...WILL
SLOWLY BE REPLACED BY A RIDGE. THIS RIDGE WILL REMAIN IN PLACE FROM
FRIDAY THROUGH SUNDAY...EXTENDING FROM STRONG HIGH OVER FAR NORTHERN
CANADA AND GREENLAND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...07
AVIATION...JLB
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
122 AM EDT THU APR 23 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 344 PM EDT WED APR 22 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED UPR LO/
POCKET OF H5 TEMPS NEAR -30C CENTERED OVER ONTARIO TO THE SW OF
JAMES BAY DOWNSTREAM OF HI AMPLITUDE RDG OVER THE ROCKIES. DEEP
MOIST CYC NW FLOW ARND THE CLOSED LO CONTINUES TO IMPACT UPR MI...
DRAWING UNSEASONABLY CHILLY AIR /H85 TEMPS AS LO AS -12 TO -14C THAT
ARE SUFFICIENTLY COLD FOR LES/ INTO THE AREA. THE RESULT HAS BEEN
NMRS SN SHOWERS THAT HAVE BEEN EXACERBATED OVER LAND WITH DAYTIME
HEATING EVEN IN THE ABSENCE OF SGNFT LARGER SCALE FORCING/DEEP LYR
QVECTOR CNVGC.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/SN AMOUNTS
ESPECIALLY TNGT AS UPR LO DRIFTS SLOWLY TO THE E. TEMPS WL REMAIN
BLO NORMAL THRU THU.
TNGT...UPR LO IS FCST TO DRIFT SLOWLY TO THE E...ALLOWING FOR SLOWLY
RISING H5 HGT/WEAKENING LLVL CYC FLOW. ALTHOUGH SOME GENERAL LARGER
SCALE SUBSIDENCE IS FCST TO DOMINATE...H85 TEMPS REMAINING AS LO AS
ABOUT -13C IN THE PRESENCE OF SOME LINGERNING DEEP MSTR/NOCTURNAL
COOLING WL BE SUFFICIENT TO MAINTAIN LES IN THE FAVORED NW WIND SN
BELTS OVER THE ERN CWA. EXPECT UP TO A COUPLE INCHES OF SN ACCUM IN
THIS AREA. OVER THE W...WARMING H85 TEMPS TO ARND -10C/ LOWERING
SUBSIDENCE INVRN UNDER THE GREATER HGT RISES SHOULD TEND TO CAUSE
THE SN SHOWERS TO DIMINISH IN THAT AREA. HOWEVER...THE PERSISTENT
UPSLOPE NW FLOW AND LINGERING UPSLOPE FLOW WL ALLOW FOR AT LEAST
SOME SCT SN SHOWERS EVEN IN THAT AREA.
THU...PERSISTENT HGT RISES AND SUBSIDENCE/TENDENCY FOR THE LLVL FLOW
TO BECOME MORE ACYC AS WELL AS SOME LLVL DRYING IN THE PRESENCE OF
DAYTIME HEATING WL DIMINISH THE SN SHOWERS W-E. FCST SDNGS INDICATE
THERE WL BE SOME SUNSHINE IN THE AFTN AS WELL WITH HI PRES RDG FCST
TO BLD INTO THE WRN CWA LATER IN THE DAY. TEMPS SHOULD REBOUND INTO
THE 40S OVER THE INTERIOR W AND SCENTRAL AWAY FM LK MODERATION WITH
H85 TEMPS PROGGED TO REACH NEAR -6C ALONG THE WI BORDER BY 00Z FRI.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM EDT WED APR 22 2015
EVEN AS A SFC RIDGE MOVES IN FROM THE W THU NIGHT...ISOLATED SNOW
SHOWERS SHOULD LINGER INTO THE NIGHT IN NW WIND SNOWBELTS NEAR ERN
LAKE SUPERIOR. THIS AS 850MB TEMPS WILL BE AROUND -10C UNDER NW
WINDS. BY FRI MORNING...THE INCREASING INFLUENCE OF THE RIDGE AND
THE WARNING AIRMASS OVERHEAD WILL MAKE FOR A DRY DAY ACROSS THE U.P.
/RULING AT THE 12Z/22 GFS AS AN OUTLIER WITH THE LIGHT PRECIP OVER
THE FAR W/. CLEARING SKIES FROM W TO E THU NIGHT INTO FRI WILL LEAD
TO MIN TEMPS THU NIGHT IN THE TEENS OVER THE INTERIOR W AND IN THE
20S ELSEWHERE. HIGHS ON FRI WILL RANGE FROM THE MID 30S NEAR
CENTRAL/ERN LAKE SUPERIOR TO THE UPPER 40S ALONG THE WI BORDER.
THE WEEKEND LOOKS DRY...SUNNIER AND WARMER AS A SFC LOW SLIDES WELL
S OF THE CWA WITH SFC AND UPPER RIDGING REMAINING OVER THE CWA.
850MB TEMPS HOVERING AROUND 0C SAT AND SUN COMBINED WITH THE PARTLY
CLOUDS SKIES WILL MAKE FOR HIGHS IN THE 40S TO LOW 50S...COOLEST
NEAR LAKE SUPERIOR OVER AND E OF THE KEWEENAW DUE TO E-NE FLOW OFF
THE LAKE. THE RELATIVELY WEAK FLOW AND MORE LIMITED CLOUD COVER WILL
ALLOW MIN TEMPS SAT AND SUN NIGHTS TO BE IN THE MID 20S INLAND TO
LOW 30S ELSEWHERE.
MON ALSO LOOKS FREE OF PRECIP AS RIDGING WEAKENS BUT REMAINS
OVERHEAD. THE ECMWF SUGGEST THE UPPER LOW CURRENTLY IMPACTING THE
REGION MAY RETROGRADE BACK TOWARD THE AREA AFTER SITTING OVER NEW
ENGLAND...BUT THAT WOULD ONLY LEAD TO LIGHT PRECIP OVER THE E IF
THAT DID OCCUR...BUT WILL LEAVE PRECIP OUT OF THE FORECAST FOR NOW.
850MB TEMPS INCREASE A COUPLE OF DEGREES ON MON...BUT TEMPS SHOULD
BE SIMILAR TO SUN AS CLOUD COVER WILL BE INCREASED.
NOT REAL CONFIDENT FOR TUE AND WED AS MODELS SHOW UPPER LEVEL
IMPULSES MOVING THROUGH THE REGION...BUT THERE IS QUITE A BIT OF RUN
TO RUN AND MODEL TO MODEL DISCONTINUITY DURING THIS TIME AS A MORE
SIGNIFICANT PATTERN SHIFT MAY BE STARTING. PRECIP CHANCES ARE
GREATER THAN FRI-MON...BUT NOT HIGH BY ANY MEANS. TEMPS ON TUE LOOK
TO BE SIMILAR TO TUE...BUT MAY COOL DOWN A BIT ON WED. JUST USED A
CONSENSUS OF GUIDANCE FOR THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 120 AM EDT THU APR 23 2015
EXPECT PREDOMINANT MVFR CONDITIONS WITH COLD...MOIST NW FLOW OF AIR
AROUND DEEP LOW PRES IN SE CANADA OVERNIGHT EVEN THROUGH SOME
LINGERING SNOW SHOWERS COULD REDUCE VSBY BRIEFLY TO IFR AT IWD/CMX.
IMPROVEMENT TO VFR CONDITIONS IS EXPECTED THURSDAY MORNING WITH THE
CLOSER APPROACH OF SFC HIGH PRES AND DRIER AIR UNDER LARGE SCALE
SUBSIDENCE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT WED APR 22 2015
A FEW NW WINDS GUSTING TO 30 TO NEAR 35KT GALES WILL REMAIN POSSIBLE
OVER N AND CENTRAL LAKE SUPERIOR THIS EVENING. LOW PRESSURE ACROSS
JAMES BAY WILL FILL LATE TONIGHT AND THURSDAY. THE TROUGH ACROSS
LAKE SUPERIOR THIS MORNING...EXTENDING FROM THE JAMES BAY LOW...WILL
SLOWLY BE REPLACED BY A RIDGE. THIS RIDGE WILL REMAIN IN PLACE FROM
FRIDAY THROUGH SUNDAY...EXTENDING FROM STRONG HIGH OVER FAR NORTHERN
CANADA AND GREENLAND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...JLB
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
310 AM CDT THU APR 23 2015
.UPDATE...
PATCHY FOG HAS DEVELOPED AND EXPECT IT WILL CONTINUE AS MOST
PLACES ARE SATURATED. HAVE ADDED FOG FOR THIS MORNING.
&&
.PREV DISCUSSION... /ISSUED 109 AM CDT THU APR 23 2015/
AVIATION... /06Z TAF UPDATE/
SURFACE WINDS HAVE BECOME MOSTLY DECOUPLED ALONG HIGHWAY 90 TO
PROMOTE MAINLY IFR CONDITIONS AT DRT/SAT/SSF. RELATIVELY LIGHT
LOW LEVEL WINDS OF 15-20 KNOTS OFF THE DECK AS SHOWN IN VAD WIND
DATA WOULD SUGGEST A FEW AREAS SHOWING LIGHT FOG ALONG HIGHWAY
90...BUT CIGS ARE MORE LIKELY TO FALL INTO THE LIFR CATEGORY AS
DECOUPLING CONTINUES INTO DAYBREAK. THE SURFACE MOISTURE GRADIENT
WOULD SUGGEST GRADUAL MOISTURE ADVECTION TO HELP KEEP IFR CIGS IN
THROUGH MID MORNING AND MOST AREAS IN MVFR CONDITIONS INTO THE
EARLY AFTERNOON. THERE SHOULD BE A GOOD CHANCE FOR SOME VFR SKIES
IN THE LATE AFTERNOON AND EARLY EVENING BEFORE CLOUDS RETURN. CAP
STRENGTH IS EXPECTED TO HOLD OFF MOST CONVECTION INTO THIS
EVENING...BUT FUTURE TAF UPDATES WILL LIKELY NEED TO ADD A TEMPO
OR POSSIBLE PREVAILING THUNDERSTORM CATEGORY IN THE LAST 12 TO 18
HOURS OF THE FORECAST.
PREV DISCUSSION... /ISSUED 733 PM CDT WED APR 22 2015/
UPDATE...
CURRENT FORECAST IS IN DECENT SHAPE. WILL LEAVE 20/30 POPS IN THE
FORECAST BUT OVERALL CHANCES FOR ADDITIONAL PRECIP IS LOW GIVEN
THE ATMOSPHERE IS PRETTY WORKED OVER FROM THE EARLIER CONVECTION.
AREAS SOUTH OF SAN ANTONIO RECEIVED BETWEEN 1-2 INCHES ACROSS A
LARGE AREA. OTHERWISE...MADE MINOR ADJUSTMENTS TO THE HOURLY
GRIDS FOR CURRENT TRENDS.
HAMPSHIRE
PREV DISCUSSION... /ISSUED 231 PM CDT WED APR 22 2015/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
SEMI ACTIVE WEATHER PATTERN FOR THE NEXT FEW DAYS FOLLOWED BY A
FRONT THIS WEEKEND THEN DRYING OUT EARLY NEXT WEEK.
AS OF 2 PM THERE IS A MULTICELL CLUSTER OF THUNDERSTORMS
APPROACHING BEXAR COUNTY AND SAN ANTONIO. THE HRRR TAKES THIS
COMPLEX AS WELL AS OTHER SHOWERS AND THUNDERSTORMS OUT AHEAD OF IT
EASTWARD IMPACTING A BASTROP SOUTH TO GONZALES AND KENEDY LINE.
MODEL SOUNDINGS FROM THE NAM SHOW AN UNCAPPED ATMOSPHERE ALONG
AND EAST OF I-35 THIS AFTERNOON WITH 1000-3000 J/KG OF CAPE AND
50-60 KNOTS OF SHEAR. THIS MEANS THAT THIS COMPLEX OF STORMS IS
MOVING INTO A VERY GOOD ENVIRONMENT FOR STRONG TO SEVERE STORMS.
WE CONTINUE UNDER A SLIGHT RISK FROM SPC THIS AFTERNOON ALONG AND
EAST OF US HWY 281. WE HAVE ALSO SEEN HEAVY RAINFALL RATES OUT OF
THE ONGOING STORMS SO SOME LOCALIZED FLOODING IS NOT OUT OF THE
QUESTION WITH THE STRONGER STORMS. THE MAIN THREATS WILL BE LARGE
HAIL AND DAMAGING WINDS WITH ANY SEVERE WEATHER THAT DOES OCCUR
THIS AFTERNOON AND EVENING. THE THREAT FOR TORNADOES REMAINS LOW
AS LOW LEVEL SHEAR IS WEAK.
OTHER FEATURES IN PLAY TODAY ARE A STATIONARY FRONT ACROSS THE
RED RIVER IN NORTH TEXAS AND THE DRYLINE OUT IN WEST
TEXAS...ALTHOUGH OTHER THAN AN ISOLATED DRYLINE STORM NEITHER WILL
IMPACT OUR WEATHER MUCH. GENERAL RIDGING IS FORECAST TO TAKE
PLACE THROUGH THE PERIOD AS HIGH PRESSURE OVER NORTHERN MEXICO
MOVES SLOWLY EAST. CONVECTION WILL DECREASE OVERNIGHT TONIGHT AND
WITH NORTHWEST FLOW CONTINUING ONLY SLIGHT CHANCES FOR
PRECIPITATION ARE FORECAST FOR THURSDAY THROUGH THURSDAY EVENING.
MODEL SOUNDINGS SHOW A STRONG CAP ACROSS MOST OF SOUTH CENTRAL
TEXAS DURING THE DAY TOMORROW. BY LATE IN THE AFTERNOON MODELS DO
WEAKEN THE CAP WHICH COULD ALLOW FOR SOME ISOLATED SHOWERS AND
THUNDERSTORMS. AGAIN...CONDITIONS WILL BE FAVORABLE TOMORROW FOR
SEVERE WEATHER WITH 50 KNOTS OF UPPER LEVEL SHEAR AND 2000-3000
J/KG OF CAPE. THE DAY 2 OUTLOOK FROM SPC HAS THE WHOLE AREA IN A
SLIGHT RISK FOR TOMORROW...WITH LARGE HAIL AND DAMAGING WINDS
AGAIN THE PRIMARY THREATS.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
MODELS ARE IN AGREEMENT THAT THURSDAY NIGHT THROUGH FRIDAY MORNING
WILL BE A PERIOD OF HIGHER QPF...HIGHER RAIN CHANCES. THE GREATEST
CHANCES FOR RAIN WILL BE ALONG THE RIO GRANDE PLAINS THURSDAY
NIGHT SPREADING TO AREAS ALONG AND EAST OF I-35 FOR FRIDAY. AN
UPPER LEVEL TROUGH APPROACHING FROM THE WEST WILL PROVIDE THE
NEEDED LIFT FOR THIS PRECIPITATION. CHANCES OF SEVERE WEATHER
CONTINUE INTO FRIDAY WITH THE BEST INSTABILITY LOCATED ALONG AND
WEST OF I-35. AS THE TROUGH MOVES OFF TO THE EAST AND NORTHEAST
SATURDAY CHANCES FOR RAIN WILL DECREASE THROUGH THE DAY. THE NEXT
FRONT WILL MOVE THROUGH SUNDAY INTO MONDAY. THE GFS AND NEW 12Z
ECMWF DISAGREE BY ABOUT 24 ON THE TIMING OF THIS FRONT...WITH THE
ECMWF BRING THE SLOWER OF THE TWO. WILL GO WITH A PERSISTENCE
FORECAST AND CHANCE POPS FOR SUNDAY AND MONDAY...DRYING OUT
TUESDAY. THE ONE BENEFIT OF THIS FRONT IS IT WILL COOL THE AREA
BACK DOWN INTO THE 70S FOR HIGHS FOR A FEW DAYS BY THE MIDDLE OF
NEXT WEEK.
TREADWAY
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 88 71 84 67 88 / 30 30 60 40 20
AUSTIN BERGSTROM INTL AIRPORT 86 70 84 66 87 / 30 30 60 40 20
NEW BRAUNFELS MUNI AIRPORT 88 70 85 67 88 / 20 40 50 50 20
BURNET MUNI AIRPORT 87 68 83 63 87 / 30 40 60 30 10
DEL RIO INTL AIRPORT 89 68 87 64 89 / 20 40 30 30 10
GEORGETOWN MUNI AIRPORT 86 70 84 65 88 / 30 40 60 30 10
HONDO MUNI AIRPORT 87 70 84 66 88 / 20 50 40 50 20
SAN MARCOS MUNI AIRPORT 87 69 84 67 86 / 20 40 50 50 20
LA GRANGE - FAYETTE REGIONAL 86 71 84 69 86 / 20 30 40 40 20
SAN ANTONIO INTL AIRPORT 88 71 85 68 88 / 20 40 50 50 20
STINSON MUNI AIRPORT 87 71 85 69 88 / 20 40 50 50 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...18
SYNOPTIC/GRIDS...05
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
109 AM CDT THU APR 23 2015
.AVIATION... /06Z TAF UPDATE/
SURFACE WINDS HAVE BECOME MOSTLY DECOUPLED ALONG HIGHWAY 90 TO
PROMOTE MAINLY IFR CONDITIONS AT DRT/SAT/SSF. RELATIVELY LIGHT
LOW LEVEL WINDS OF 15-20 KNOTS OFF THE DECK AS SHOWN IN VAD WIND
DATA WOULD SUGGEST A FEW AREAS SHOWING LIGHT FOG ALONG HIGHWAY
90...BUT CIGS ARE MORE LIKELY TO FALL INTO THE LIFR CATEGORY AS
DECOUPLING CONTINUES INTO DAYBREAK. THE SURFACE MOISTURE GRADIENT
WOULD SUGGEST GRADUAL MOISTURE ADVECTION TO HELP KEEP IFR CIGS IN
THROUGH MID MORNING AND MOST AREAS IN MVFR CONDITIONS INTO THE
EARLY AFTERNOON. THERE SHOULD BE A GOOD CHANCE FOR SOME VFR SKIES
IN THE LATE AFTERNOON AND EARLY EVENING BEFORE CLOUDS RETURN. CAP
STRENGTH IS EXPECTED TO HOLD OFF MOST CONVECTION INTO THIS
EVENING...BUT FUTURE TAF UPDATES WILL LIKELY NEED TO ADD A TEMPO
OR POSSIBLE PREVAILING THUNDERSTORM CATEGORY IN THE LAST 12 TO 18
HOURS OF THE FORECAST.
&&
.PREV DISCUSSION... /ISSUED 733 PM CDT WED APR 22 2015/
UPDATE...
CURRENT FORECAST IS IN DECENT SHAPE. WILL LEAVE 20/30 POPS IN THE
FORECAST BUT OVERALL CHANCES FOR ADDITIONAL PRECIP IS LOW GIVEN
THE ATMOSPHERE IS PRETTY WORKED OVER FROM THE EARLIER CONVECTION.
AREAS SOUTH OF SAN ANTONIO RECEIVED BETWEEN 1-2 INCHES ACROSS A
LARGE AREA. OTHERWISE...MADE MINOR ADJUSTMENTS TO THE HOURLY
GRIDS FOR CURRENT TRENDS.
HAMPSHIRE
PREV DISCUSSION... /ISSUED 231 PM CDT WED APR 22 2015/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
SEMI ACTIVE WEATHER PATTERN FOR THE NEXT FEW DAYS FOLLOWED BY A
FRONT THIS WEEKEND THEN DRYING OUT EARLY NEXT WEEK.
AS OF 2 PM THERE IS A MULTICELL CLUSTER OF THUNDERSTORMS
APPROACHING BEXAR COUNTY AND SAN ANTONIO. THE HRRR TAKES THIS
COMPLEX AS WELL AS OTHER SHOWERS AND THUNDERSTORMS OUT AHEAD OF IT
EASTWARD IMPACTING A BASTROP SOUTH TO GONZALES AND KENEDY LINE.
MODEL SOUNDINGS FROM THE NAM SHOW AN UNCAPPED ATMOSPHERE ALONG
AND EAST OF I-35 THIS AFTERNOON WITH 1000-3000 J/KG OF CAPE AND
50-60 KNOTS OF SHEAR. THIS MEANS THAT THIS COMPLEX OF STORMS IS
MOVING INTO A VERY GOOD ENVIRONMENT FOR STRONG TO SEVERE STORMS.
WE CONTINUE UNDER A SLIGHT RISK FROM SPC THIS AFTERNOON ALONG AND
EAST OF US HWY 281. WE HAVE ALSO SEEN HEAVY RAINFALL RATES OUT OF
THE ONGOING STORMS SO SOME LOCALIZED FLOODING IS NOT OUT OF THE
QUESTION WITH THE STRONGER STORMS. THE MAIN THREATS WILL BE LARGE
HAIL AND DAMAGING WINDS WITH ANY SEVERE WEATHER THAT DOES OCCUR
THIS AFTERNOON AND EVENING. THE THREAT FOR TORNADOES REMAINS LOW
AS LOW LEVEL SHEAR IS WEAK.
OTHER FEATURES IN PLAY TODAY ARE A STATIONARY FRONT ACROSS THE
RED RIVER IN NORTH TEXAS AND THE DRYLINE OUT IN WEST
TEXAS...ALTHOUGH OTHER THAN AN ISOLATED DRYLINE STORM NEITHER WILL
IMPACT OUR WEATHER MUCH. GENERAL RIDGING IS FORECAST TO TAKE
PLACE THROUGH THE PERIOD AS HIGH PRESSURE OVER NORTHERN MEXICO
MOVES SLOWLY EAST. CONVECTION WILL DECREASE OVERNIGHT TONIGHT AND
WITH NORTHWEST FLOW CONTINUING ONLY SLIGHT CHANCES FOR
PRECIPITATION ARE FORECAST FOR THURSDAY THROUGH THURSDAY EVENING.
MODEL SOUNDINGS SHOW A STRONG CAP ACROSS MOST OF SOUTH CENTRAL
TEXAS DURING THE DAY TOMORROW. BY LATE IN THE AFTERNOON MODELS DO
WEAKEN THE CAP WHICH COULD ALLOW FOR SOME ISOLATED SHOWERS AND
THUNDERSTORMS. AGAIN...CONDITIONS WILL BE FAVORABLE TOMORROW FOR
SEVERE WEATHER WITH 50 KNOTS OF UPPER LEVEL SHEAR AND 2000-3000
J/KG OF CAPE. THE DAY 2 OUTLOOK FROM SPC HAS THE WHOLE AREA IN A
SLIGHT RISK FOR TOMORROW...WITH LARGE HAIL AND DAMAGING WINDS
AGAIN THE PRIMARY THREATS.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
MODELS ARE IN AGREEMENT THAT THURSDAY NIGHT THROUGH FRIDAY MORNING
WILL BE A PERIOD OF HIGHER QPF...HIGHER RAIN CHANCES. THE GREATEST
CHANCES FOR RAIN WILL BE ALONG THE RIO GRANDE PLAINS THURSDAY
NIGHT SPREADING TO AREAS ALONG AND EAST OF I-35 FOR FRIDAY. AN
UPPER LEVEL TROUGH APPROACHING FROM THE WEST WILL PROVIDE THE
NEEDED LIFT FOR THIS PRECIPITATION. CHANCES OF SEVERE WEATHER
CONTINUE INTO FRIDAY WITH THE BEST INSTABILITY LOCATED ALONG AND
WEST OF I-35. AS THE TROUGH MOVES OFF TO THE EAST AND NORTHEAST
SATURDAY CHANCES FOR RAIN WILL DECREASE THROUGH THE DAY. THE NEXT
FRONT WILL MOVE THROUGH SUNDAY INTO MONDAY. THE GFS AND NEW 12Z
ECMWF DISAGREE BY ABOUT 24 ON THE TIMING OF THIS FRONT...WITH THE
ECMWF BRING THE SLOWER OF THE TWO. WILL GO WITH A PERSISTENCE
FORECAST AND CHANCE POPS FOR SUNDAY AND MONDAY...DRYING OUT
TUESDAY. THE ONE BENEFIT OF THIS FRONT IS IT WILL COOL THE AREA
BACK DOWN INTO THE 70S FOR HIGHS FOR A FEW DAYS BY THE MIDDLE OF
NEXT WEEK.
TREADWAY
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 70 85 67 87 65 / 40 60 30 20 -
AUSTIN BERGSTROM INTL AIRPORT 70 84 66 87 63 / 40 50 30 20 -
NEW BRAUNFELS MUNI AIRPORT 71 85 67 87 64 / 40 50 40 30 -
BURNET MUNI AIRPORT 68 84 64 86 63 / 40 60 20 - -
DEL RIO INTL AIRPORT 68 88 64 89 64 / 50 30 30 - -
GEORGETOWN MUNI AIRPORT 70 84 65 87 63 / 40 60 20 10 -
HONDO MUNI AIRPORT 71 85 66 88 63 / 40 40 50 20 -
SAN MARCOS MUNI AIRPORT 70 84 67 86 64 / 40 50 40 30 -
LA GRANGE - FAYETTE REGIONAL 72 85 69 86 66 / 30 50 40 30 -
SAN ANTONIO INTL AIRPORT 71 85 68 88 66 / 40 50 50 30 -
STINSON MUNI AIRPORT 71 85 69 87 65 / 40 40 50 30 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...18
SYNOPTIC/GRIDS...05
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1153 PM CDT WED APR 22 2015
.DISCUSSION...
06Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
WEAKENING WINDS WITHIN A SLIGHTLY MORE MOIST RESIDENT AIR MASS HAS
THIS TAF TRENDING TOWARDS LOW END MVFR TO (TEMPO) IFR EARLY MORNING
CEILINGS. ALTHOUGH RECENT MODEL RUNS HAVE BEEN TOO AGGRESSIVE ON
LOWERING DECKS INTO (L)IFR...THE LARGE SCALE SET-UP OF GENERAL
HIGH PRESSURE OVER THE REGION WILL SET AN ENVIRONMENT MORE
CONDUCIVE FOR THE LOWERING OF BKN-OVC DECKS AND POSSIBLE BRIEF
MVFR BR BEGINNING THURSDAY MORNING...A HIGHER PROB OF IT RE-OCCURRING
LATE THURSDAY NIGHT INTO FRIDAY MORNING. THERE IS A SLIGHT CHANCE
FOR THURSDAY PM CONVECTION BUT TOO LOW AT THE MOMENT TO MENTION
WITHIN THIS PACKAGE. CONVECTIVE CHANCES WILL INCREASE FRIDAY...BUT
RECENT MODEL RUNS HAVE THE GREATEST IMPACT FOR INCLEMENT WEATHER
FOCUSED OFF TO THE NORTH OF THE FORECAST AREA. 31
&&
.PREV DISCUSSION... /ISSUED 937 PM CDT WED APR 22 2015/
DISCUSSION...
WOW! THE SUPERCELL THAT MOVED OFF THE COAST ACROSS THE SAN ANTONIO
BAY AREA EARLIER THIS EVENING MADE IT ALL THE WAY OVER TO BUOY 42019...
AND AT 729 PM CDT PRODUCED A WIND GUST OF 76 KNOTS (87 MPH)! THIS WAS
THE SAME STORM THAT EARLIER PRODUCED LARGE HAIL AND WIND DAMAGE ALONG
THE WEST END OF SAN ANTONIO BAY (REFUGIO AND ARANSAS COUNTY AREA).
THERE WILL CONTINUE TO BE A CHANCE OF SHOWERS/THUNDERSTORMS ACROSS PARTS
OF OUR AREA OVERNIGHT...ESPECIALLY UP NORTH DURING THE REST OF THE EVENING
HOURS...AS ACTIVITY HEADS OUR WAY. 42
&&
PREV DISCUSSION... /ISSUED 712 PM CDT WED APR 22 2015/
DISCUSSION...
00Z AVIATION DISCUSSION BELOW.
AVIATION...
THIS EVENING`S SUPERCELL THAT MOVED OFF THE UPPER TEXAS COAST AND
ACROSS SAN ANTONIO BAY APPEARS TO HAVE ROBBED INFLOW INTO THE
ONCE RAGGED SOUTHWESTERN FORECAST AREA`S CONVECTION THAT WAS
MOVING EAST AN HOUR AGO. ALL THAT IS LEFT IS A LIGHT RAIN SHIELD
CURRENTLY AFFECTING LBX...THIS LIGHT PRECIPITATION MOVING SOUTH
OF THE METRO TERMINALS. VFR DECKS THIS EVENING WILL LOWER BACK TO
MVFR JUST BEFORE SUNRISE. A LIGHT SOUTH BREEZE WITH CEILINGS
LIFTING BACK UP TO VFR BY LATE THURSDAY MORNING. UPPER RIDGING
FORMING JUST DOWNSTREAM OF NEXT BAJA REGION TROUGH SHOULD PROVIDE
ENOUGH SUBSIDENCE TO KEEP THURSDAY DRY. REGIONAL PROG SOUNDINGS
DEPICT A DRYING COLUMN...ESPECIALLY IN THE MID-LAYERS...AND NO
DISCERNIBLE APPROACHING UPSTREAM SHORTWAVE DISTURBANCE AID IN
LEANING THIS TAF PACKAGE TOWARDS A DRY BIAS. 31
&&
PREV DISCUSSION... /ISSUED 402 PM CDT WED APR 22 2015/
DISCUSSION...
UPPER AIR ANALYSIS AND WATER VAPOR IMAGERY STILL SHOW A RATHER
PERSISTENT SOUTHERN JET STREAM OVER MUCH OF TX. IT IS HARD TO
IDENTIFY BUT IT APPEARS THAT THE CONVECTION OVER THE COASTAL BEND
AND NOW EAST OF SAN ANTONIO MAY BE SUPPORTED BY A WEAK SHORTWAVE
TROUGH. OVERALL PATTERN SHOWS WEAK SHORT WAVE RIDGING BUT THIS
DISTURBANCE MAY BE FLATTENING OUT THE RIDGE A BIT TODAY.
THERMODYNAMIC AND SHEAR PARAMETERS SUPPORT THE THREAT FOR SEVERE
STORMS WITH SOME STORMS BECOMING ORGANIZED. SHEAR WILL SUPPORT
STORM ROTATION AND LOW LEVEL TURNING OF THE WINDS WITH A
DEVELOPING WARM FRONT MAY BE ENOUGH TO SUPPORT LOW LEVEL ROTATION
IN STORMS ESPECIALLY ALONG THE COASTAL BEND. RECENT RAP/HRRR MODEL
RUNS BRING CONVECTION EAST OF KSAT INTO SE TX AROUND 23-01Z.
MODELS SHOW THAT STORMS MAY BE WEAKENING BUT COULD BE MOVING INTO
A MORE FAVORABLE ENVIRONMENT GIVEN TRENDS IN HEATING/INSTABILITY.
MODELS ALSO SHOW CONVECTION ALONG A BOUNDARY STRETCHING NW/SE FROM
MINERAL WELLS TO LUFKIN. THIS HIGHLIGHTS THE SEVERE THREAT FOR THE
NORTHERN MOST COUNTIES IN THE FORECAST AREA MAINLY
MADISON...HOUSTON...TRINITY CO. THE IDEA IS FOR THE THREAT TO END
LATER TONIGHT BUT HRRR TRENDS SHOW CONVECTION COMING DOWN FROM
THE METROPLEX AND AFFECT THE AREAS FROM COLLEGE STATION TO
HUNTSVILLE OVER THE LIVINGSTON BY EARLY MORNING HOURS. SO IT
APPEARS THERE WILL BE AT LEAST SOME OVERNIGHT THREAT.
THURSDAY LOOKS A BIT MORE QUIET AS MODELS DO AMPLIFY RIDGING OVER
THE REGION ALTHOUGH THERE WILL BE PLENTY OF MOISTURE/INSTABILITY
TO SUPPORT SEVERE STORMS. WE DO NOT WANT TO BE COMPLACENT BUT
THINK 20/30 POPS MIGHT BE GENEROUS. MOVING AHEAD TO
FRIDAY...RIDGING MOVES EAST IN RESPONSE TO UPPER LEVEL TROUGH OVER
THE S ROCKIES PUSHING INTO THE TX PANHANDLE AND S PLAINS. SFC LOW
DEEPENS AND MOVES INTO THE C PLAINS IN RESPONSE WITH STRONG JET
STREAK FROM MIDLAND TO OKC. THIS PUTS SE TX ON A MORE SUBSIDENT
SIDE OF THE JET BUT THAT MAY NOT MATTER MUCH WITH THE CURVATURE OF
THE JET. THERE IS ALSO A PACIFIC FRONT THAT DEVELOPS WITH
CONVECTION FORMING IN C TX MOVING EAST. THIS WILL AGAIN PUT AREAS
NORTH OF I-10 IN A THREAT FOR SEVERE WEATHER SINCE THERE WILL
AGAIN BE PLENTY OF MOISTURE/INSTABILITY AND SHEAR. MAIN QUESTION
WILL BE CAP STRENGTH. 850MB WINDS VEER TO SW WITH TEMPS AROUND 20C
OR MORE FOR MUCH OF THE SOUTHERN HALF OF THE AREA. AGAIN THIS
SUPPORTS IDEA OF AREAS NORTH OF I-10 OR EVEN NORTH OF CONROE WILL
HAVE A HIGHER THREAT FOR SEVERE WEATHER FRIDAY.
WE CONTINUE THUNDERSTORM CHANCES SATURDAY AS THE THROUGH PASSES NE
OF THE AREA OVERNIGHT. SOUTHERN JET STILL IS STRONG OVER THE
REGION. PACIFIC FRONT STALLS OVER THE AREA WHICH COULD SUPPORT A
FEW STORMS BUT WITH 850MB FLOW BECOMING MORE WSW...THINK STORMS
WILL BE ISO IN NATURE. WITH THE VEERED BOUNDARY LAYER FLOW...MAX
TEMPS COULD REACH UPPER 80S TO 90F BOTH SAT/SUN.
WHILE THERE MAY BE A BREAK FROM SEVERE WEATHER OVER THE
WEEKEND...MONDAY COULD BE ACTIVE AGAIN. BOTH GFS/ECMWF BRING A
UPPER LOW INTO THE PLAINS DURING THE DAY MON WITH FAVORABLE
SPLITTING JET STRUCTURE. LARGE SCALE ASCENT WILL BE STRONG ENOUGH
TO ERODE ANY CAPPING LEADING TO A MID MORNING TO EARLY AFTERNOON
SEVERE WEATHER CHANCES. DRYLINE/PACIFIC FRONT PUSHES THROUGH MON
NIGHT INTO TUE AS THUNDERSTORM ACTIVITY MOVES EAST. A STRONGER
COLD FRONT PUSHES THROUGH TUESDAY WHICH MUCH COLDER AIR BEHIND IT.
IN FACT THE 850MB TEMPS DROP TO ANYWHERE BETWEEN 4C AND 8C TUE
NIGHT INTO WED DEPENDING ON THE MODEL. SO IT LOOKS LIKE MONDAY
WILL NEED TO BE WATCHED CLOSELY FOR DETAILS ON SEVERE WEATHER BUT
GOOD NEWS THAT THERE COULD BE A STRONG COLD FRONT TO PUSH THROUGH
ONE LAST TIME BEFORE HEADING INTO THE MONTH OF MAY. 39
MARINE...
AS HIGH PRESSURE LINGERS TO THE EAST AND PRESSURES FALL OVER THE SRN
PLAINS...THE LIGHT/MODERATE ONSHORE FLOW WILL BE CONTINUING OVER THE
UPPER TX COAST THROUGH THE END OF THE WEEK/INTO THE WEEKEND. STRONG-
ER GUSTS/LIMITED VISIBILITIES POSSIBLE WITH STORMS DEVELOPING ACROSS
THE COASTAL WATERS THE REST OF THIS AFTN/EVENING...WITH LATER ROUNDS
OF PCPN POSSIBLE THURS AND FRI. LONG-RANGE MODELS STILL GOING WITH A
STRONG COLD FRONT INTO THE GULF WATERS NEXT TUES. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 70 85 71 83 68 / 30 30 30 60 20
HOUSTON (IAH) 69 86 73 84 71 / 20 20 20 40 20
GALVESTON (GLS) 72 82 73 82 73 / 20 20 20 30 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...42
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1149 PM CDT WED APR 22 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 243 PM CDT WED APR 22 2015
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER TROUGHS OVER BRITISH COLUMBIA...ALONG THE SOUTHERN
CALIFORNIA COAST...AND OVER THE FORECAST AREA INTO THE GREAT
LAKES...WHILE RIDGING EXTENDED FROM THE FOUR CORNERS OF THE U.S.
INTO ALBERTA. CYCLONIC FLOW OF MOISTURE AROUND THE GREAT LAKES UPPER
TROUGH...NICELY SEEN ON THE 12Z GRB SOUNDING...HELPING TO HOLD
STRATOCUMULUS ACROSS WI. GO A LITTLE MORE TO THE WEST OVER MN AND
IA...MUCH DRIER AIR WAS PRESENT ON THE 12Z MPX SOUNDING WITH A
PRECIPITABLE WATER OF 0.16 INCHES OR 36 PERCENT OF NORMAL. THIS
DRIER AIR HAS RESULTED IN CLEARER SKIES. A RIDGE OF HIGH PRESSURE
ACCOMPANYING THE CLEAR SKIES WAS LOCATED OVER THE EASTERN DAKOTAS. A
TIGHT PRESSURE GRADIENT EAST OF THIS RIDGE MAINTAINING A BRISK
NORTHWEST BREEZE OVER THE FORECAST AREA WITH SPEEDS/GUSTS A LITTLE
LOWER THAN 24 HRS AGO. STILL...THE SPEEDS HAVE BEEN STRONG ENOUGH TO
WARRANT THE EARLIER ISSUED WIND ADVISORY FOR A SMALL PORTION OF
NORTHEAST IOWA. AIRMASS REMAINS UNSEASONABLY COOL WITH 850MB TEMPS
IN THE -5 TO -8C RANGE...RESULTING IN THE PRESENT 40S
TEMPERATURES...AND EVEN 30S AT MEDFORD WI.
THE UPPER TROUGH AFFECTING THE FORECAST AREA INTO THE GREAT LAKES IS
PROGGED TO MAKE MUCH MORE EASTWARD PROGRESS OVER THE NEXT 24
HOURS...REACHING NEW ENGLAND BY 00Z FRI. THIS WILL ALLOW THE RIDGING
AND WARMER/DRIER AIR OVER THE NORTHERN ROCKIES AND PLAINS TO MARCH
TOWARDS THE FORECAST AREA. WE DO HAVE ONE SHORTWAVE TO CONTEND WITH
COMING DOWN THE BACK SIDE OF THE UPPER TROUGH TONIGHT...WHICH ITS
MAIN IMPACT IS TO BRING IN SLIGHTLY COOLER AIR FOR 12Z THU BEFORE
THE WARMING COMMENCES.
CLOUDS MAY BE A BIT PERSISTENT NORTHEAST OF I-94 TONIGHT...THANKS TO
THAT SHORTWAVE COMING THROUGH...BUT ELSEWHERE ANY STRATOCUMULUS WILL
DISSIPATE WITH LOSS OF DAYTIME HEATING. THIS CLEARING COMBINED WITH
WINDS DIMINISHING SOME AS THE RIDGE APPROACHES I-35 BY 12Z THU IS
EXPECTED TO RESULT IN A CHILLY NIGHT. 20S SHOULD BE COMMON ACROSS
MUCH OF THE REGION BY SUNRISE WITH PERHAPS NEAR 30 READINGS IN THE
MS RIVER VALLEY. NO FROST/FREEZE HEADLINES WILL BE POSTED YET AS
VEGETATION GROWTH IS NOT QUITE THERE. 850MB TEMPS ON THU CLIMB TO 0
TO -2C BY 00Z FRI WHICH WITH PLENTY OF SUN SHOULD BE ABLE TO BOOST
TEMPERATURES INTO THE LOW TO MID 50S FOR MOST LOCATIONS. MEDFORD
AGAIN MIGHT BE THE LONE COOLER EXCEPTION BEING CLOSER TO THE
DEPARTING COLD AIR. DEEP MIXING IS LIKELY AS WELL IN THE DRY AIRMASS
FEATURING PRECIPITABLE WATER NEAR 0.10 INCHES...CAUSING LOW RELATIVE
HUMIDITY VALUES. THE COMBINATION OF THESE LOW VALUES AND A 10 TO 15
MPH NORTHWEST BREEZE COULD RESULT IN SOME FIRE WEATHER CONCERN. SEE
FIRE WEATHER SECTION BELOW FOR MORE DETAILS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 243 PM CDT WED APR 22 2015
FIRST FOCUS OF THE LONG TERM PERIOD IS ON THE UPPER TROUGH NEAR THE
SOUTHERN CALIFORNIA COAST. MODELS ARE IN GOOD AGREEMENT LIFTING THIS
TROUGH INTO THE CENTRAL PLAINS ON FRIDAY AND INTO CENTRAL ILLINOIS
ON SATURDAY. ALTHOUGH THIS TRACK IS SOUTH OF THE FORECAST AREA...WE
STILL HAVE SOME SHOT AT PRECIPITATION DURING THE FRIDAY-SATURDAY
TIME FRAME. PART OF THIS IS DUE TO A SOMEWHAT DECENT MOISTURE SURGE
AHEAD OF THE TROUGH UP INTO THE FORECAST AREA ON FRIDAY...REFLECTED
BY PRECIPITABLE WATER CLIMBING TO AROUND 0.75 INCHES BY 00Z SAT.
ADDITIONALLY...A SHORTWAVE IS PROGGED TO EJECT OUT OF THE TROUGH AND
MOVE THROUGH THE AREA ON FRIDAY...INTERACTING WITH THE MOISTURE.
THEREFORE...CHANCES OF PRECIPITATION PERSIST FOR FRIDAY...ESPECIALLY
IN THE AFTERNOON AND INTO THE NIGHT WEST OF THE MS RIVER WHERE MORE
MOISTURE EXISTS. PRECIPITATION SHOULD BEGIN TO WANE NORTH TO SOUTH
ON SATURDAY AS THE UPPER TROUGH MOVES EAST OF OUR LONGITUDE...
CUTTING OFF THE MOISTURE TRANSPORT AND ALLOWING DRIER AIR TO GET
DRAWN IN FROM THE NORTH AND EAST. SOME MODEL DIFFERENCES EXIST ON
HOW MUCH PRECIPITATION EXISTS ON SATURDAY DUE TO SLIGHT NORTH/SOUTH
DIFFERENCES OF THE UPPER TROUGH TRACK...WITH THE 22.12Z GFS/CANADIAN
FARTHEST NORTH UP TO US-10 AND 22.12Z NAM/ECMWF FARTHEST SOUTH TO
AROUND US-20. THEREFORE...PRECIPITATION CHANCES ON SATURDAY REMAIN
AT OR BELOW 50 PERCENT. BETWEEN THE CLOUDS AND PRECIPITATION...HIGH
TEMPERATURES LOOK TO BE A LITTLE COOLER THAN ON THU.
A DRIER AND WARMER PERIOD IS ON TAP FOR SUNDAY AS AN UPPER RIDGE
AXIS APPROACHES THE FORECAST AREA FROM THE WEST. WITH 850MB TEMPS OF
0-2C...SHOULD SEE HIGHS CLIMB WELL UP INTO THE 50S AND POSSIBLY 60S
IN RIVER VALLEYS. EASTERLY FLOW FROM HIGH PRESSURE OVER ONTARIO
LIKELY TO CAUSE RELATIVE HUMIDITIES TO TANK.
MODELS HAVE CHANGED THEIR TUNE A BIT FOR SUNDAY NIGHT THROUGH MONDAY
NIGHT...LEANING TOWARDS DRIER AND WARMER. THIS IS A RESULT OF A
SHORTWAVE TROUGH COMING INTO THE PACIFIC NORTHWEST ON SATURDAY
THAT...INSTEAD OF HEADING TOWARDS THE FORECAST AREA...NOW DIGS DOWN
INTO THE SOUTHERN PLAINS. THEREFORE HAVE FOLLOWED SUIT...DRYING OUT
THE FORECAST AND RAISING TEMPERATURES.
AS WE HEAD INTO TUESDAY AND WEDNESDAY...UPPER RIDGING IS PROGGED TO
DEVELOP OVER THE WESTERN U.S. INTO WESTERN CANADA...CAUSING
SHORTWAVES TO DROP INTO THE REGION ON NORTHERLY FLOW. AS A
RESULT...SOME LOW PRECIPITATION CHANCES ARE IN THE FORECAST. HARD TO
SAY HOW MUCH PRECIPITATION WILL FALL GIVEN LACK OF MOISTURE
AVAILABILITY. DESPITE THE NORTHERLY FLOW...850MB TEMPS ARE STILL
PROGGED IN THE 2-4C RANGE SO TEMPERATURES DO NOT LOOKS TO CHANGE
MUCH FROM MONDAY AND STAY JUST BELOW SEASONABLE NORMALS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1147 PM CDT WED APR 22 2015
SKIES WILL REMAIN MAINLY CLEAR THROUGH THE PERIOD. NORTHWEST WINDS
WILL REMAIN LESS THAN 10 KNOTS THROUGH 24.03Z...AND THEN BECOME
LIGHT SOUTHEAST.
&&
.FIRE WEATHER...
ISSUED AT 243 PM CDT WED APR 22 2015
TODAY HAS BEEN MOSTLY A DRYING DAY WEST OF THE MISSISSIPPI RIVER
WHERE MORE SUN HAS OCCURRED...CLOSER TO THE DRIER AIR OVER WESTERN
MN AND WINDS HAVE BEEN GUSTING 30-40 MPH. A WARMER DAY IS EXPECTED
ACROSS THE REGION ON THURSDAY WITH SUNNY SKIES. ADDITIONALLY...THE
DRY AIR OVER WESTERN MN MOVES IN...PLUMMETING RH VALUES TO 20-30
PERCENT. HOWEVER...WINDS DO NOT LOOK NEARLY AS STRONG WITH HIGH
PRESSURE MOVING IN...ONLY IN THE 10 TO 15 MPH RANGE. WITH SOME
GREEN-UP ALREADY OCCURRING AND THE LIGHTER WINDS...HAVE DECLINED
TO CONSIDER ANY FIRE WEATHER HAZARDS AT THIS TIME. SOME RAIN
REMAINS ON TAP TO MOVE INTO THE REGION FOR FRIDAY...ALONG WITH
CLOUDS...WHICH BOTH SHOULD HELP MITIGATE FIRE WEATHER CONCERNS.
LOOKING AHEAD...SUNDAY COULD BE ANOTHER DAY WORTH WATCH FOR FIRE
WEATHER CONCERNS...BUT SIMILAR TO THURSDAY WINDS ARE EXPECTED ON
THE LIGHTER SIDE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
950 AM EDT THU APR 23 2015
.DISCUSSION...
CONVECTIVE CLUSTER DVLPD JUST N OF KTBW ARND SUNRISE AND HAS PUSHED
STEADILY INTO THE E CENTRAL PENINSULA N OF SR-60. LATEST SAT IMAGERY
SHOWS WARMING TOPS ASSCD WITH THIS CLUSTER...AND OVERALL CG LTG
ACTIVITY HAS BEEN LOW. EVEN SO...KTBW RADAR SHOWS CONVECTION CELLS
EXTENDING WELL INTO THE NE GOMEX. ACTIVITY IS EMBEDDED WITHIN DEEP
AND BRISK MID/UPR LVL WRLY FLOW.
LCL AIRMASS UNDERWENT RAPID MODIFICATION OVERNIGHT...PWATS FROM THE
KTBW RAOBS INCREASED FROM 1.1" AT 00Z LAST NIGHT TO 1.8" AT 12Z THS
MRNG...KXMR VALUES INCREASED AS WELL THOUGH QUITE AS RAPID 1.0" AT
00Z TO 1.2" AT 12Z. COMPETING FRONTAL BOUNDARIES OVER THE FL
PENINSULA/NE GOMEX AND THE DEEP SOUTH WILL PUT THE OLD SQUEEZE PLAY
ON CENTRAL FL THAT WILL MAINTAIN THE MID/UPR LVL WRLY FLOW. UPSTREAM
MOISTURE IS PLENTIFUL AS RAP ANALYSIS SHOWS H100-H70 MEAN RH VALUES
BTWN 80-90PCT...H85-H50 VALUES BTWN 70-80PCT. MID LVL ANALYSIS ALSO
SHOWS A PAIR OF VORT RIPPLES IN THE H85-H50 LYR OVER THE ERN GOMEX
AND SW FL PENINSULA. H70 TEMPS ARND 5C AND H50 TEMPS ARND -10C ARE
YIELDING LAPSE RATES ARND 6.0C/KM.
BASED ON LATEST RADAR TREND AND WX ANALYSIS...WILL NUDGE POS UP TO
50-60PCT FROM NRN BREVARD/SEMINOLE/SRN LAKE CO SWD...ESP ALNG THE
COASTAL COUNTIES FROM BREVARD SWD AS LCL MOS GUIDANCE IS
SUGGESTING AN EAST COAST SEA BREEZE DVLPG FOR A FEW HRS THIS AFTN.
WILL NUDGE POPS OVER VOLUSIA/NRN LAKE UP TO 30/40PCT.
&&
.AVIATION...THRU 24/12Z
SFC WINDS: THRU 24/00Z...S/SW 5-9KTS...BTWN 23/16Z-23/22 S/SE 5-9KTS
COASTAL SITES ASSCD WITH THE EAST COAST SEA BREEZE. BTWN 24/00Z-
24/06Z... SW 3-7KTS. AFT 24-06Z...W/NW AOB 5KTS.
VSBYS/WX/CIGS: THRU 23/18Z...SCT MVFR SHRAS/ISOLD IFR TSRAS N OF
KVRB-KLAL MVG E 15-20KTS. BTWN 23/18Z-23/24Z...SCT MVFR SHRAS/ISOLD
IFR TSRAS ALL SITES. BTWN 24/00Z-24/03Z...CHC IFR TSRAS COASTAL
SITES...BCMG VFR INTERIOR SITES. AFT 24/03Z...VFR ALL SITES.
&&
.MARINE...
LOOSE SFC PGRAD OVER THE LCL ATLC WITH COMPETING FRONTAL TROFS OVER
THE FL STRAITS AND THE DEEP SOUTH AND A WEAK SFC RIDGE TUCKED IN
BETWEEN. FAVORABLE CONDS WITH S/SWRLY GRADIENT WINDS AOB 10KT...BCMG
SE NEAR THE COAST THIS AFTN WITH THE FORMATION OF THE EAST COAST SEA
BREEZE. SEAS AOB 2FT. OFFSHORE MOVING SHRAS/TSRA THIS AFTN INTO EVNG
CAPABLE OF GENERATING LCL SFC GUSTS ARND 34KTS.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...VOLKMER
AREA FORECAST DISCUSSION...UPDATE
NWS TAMPA BAY RUSKIN FL
800 AM EDT THU APR 23 2015
.UPDATE... A CLUSTER OF THUNDERSTORMS WILL MOVE ASHORE FROM HERNANDO
COUNTY SOUTHWARD TO PINELLAS COUNTY THROUGH 14/15Z. ADDITIONAL
SHOWER DEVELOPMENT IS BEGINNING FURTHER NORTH THAT WILL LIKLEY
EVENTUALLY IMPACT CITRUS AND LEVY COUNTY THIS MORNING. MOSTLY CLEAR
SKIES OVERNIGHT ACROSS THE NORTHERN NATURE COAST/BIG BEND REGION
ALLOWED FOR SOME RADIATIONAL COOLING TO TAKE PLACE. AS OF 7AM WE SAW
TEMPERATURES/DEWPOINTS CONSIDERABLY COOLER OVER THESE NORTHERN AREAS
THAT DOWN TOWARD THE I-4 CORRIDOR AND SOUTHWARD. THE COOLING HAS
ALLOWED FOR A SUBTLE LAND BREEZE/DRAINAGE FLOW TO DEVELOP AND TURN
THE WINDS OFFSHORE ALONG THE NATURE COAST. THIS PROCESS HAS DONE TWO
THINGS. ONE THE DIFFERENTIAL COOLING HAS RESULTED IN SUBTLE LOW
LEVEL FRONTOGENESIS ACROSS APALACHEE BAY...AND ALSO SET UP A DECENT
DIRECTIONAL CONVERGENCE ZONE OVER OUR NORTHERN WATERS. IT IS THIS
SURFACE CONVERGENCE/FOCUS AND THE FRONTOGENESIS CIRCULATION THAT
SEEMS TO BE THE MAIN PLAYER IN THIS DEVELOPMENT OF THIS CONVECTIVE
CLUSTER. WILL EXPECT TO CONTINUE SEEING DEVELOPMENT ACROSS THIS ZONE
UNTIL DIURNAL HEATING IS ABLE TO WEAKER/REVERSE THE LAND BREEZE FLOW
OFF THE NATURE COAST. WILL RAISE POPS ALONG AND NORTH OF THE I-4
CORRIDOR FOR THE REST OF THE MORNING. STILL APPEARS THAT ONCE THIS
INITIAL ROUND OF STORMS ACROSS THE NORTHERN FORECAST AREA ENDS THAT
THE MAJORITY OF SECOND HALF OF THE DAY CONVECTION WILL BE INLAND
ACROSS OUR SOUTH-CENTRAL ZONES. HOWEVER...WILL CONTINUE TO MONITOR
THE LATEST CONVECTION ALLOWING GUIDANCE AND ADJUST THIS AFTERNOON
FORECAST BASED ON HOW THIS GREATER THAN EXPECTED MORNING ACTIVITY
EFFECTS THE SEA-BREEZE FORMATION.
&&
.PREVIOUS DISCUSSION (TODAY-FRIDAY)... A CONVECTIVE COMPLEX OVER THE
CENTRAL-EASTERN GULF OF MEXICO EARLY THIS MORNING IS ASSOCIATED WITH
A VORT MAX THAT WILL CONTINUE TO SHIFT EASTWARD THROUGH THE REST OF
THE MORNING HOURS. RADAR IMAGERY SHOWS SOME SHOWERS OVER THIS REGION
AND WOULD EXPECT THIS ACTIVITY TO SHIFT EASTWARD AS WELL...MAKING IT
INTO OUR SOUTHERN COASTAL WATERS AND POSSIBLY EVEN COASTAL SOUTHWEST
FLORIDA BEFORE DAYBREAK. THIS IS SUPPORTED BY THE LATEST HRRR AND
OTHER HIGH-RES GUIDANCE. FOR THE REST OF TODAY...ANOTHER VORT MAX
WILL APPROACH FROM THE NORTHWEST WITH WEAK HIGH PRESSURE AT THE
SURFACE AND A FRONTAL BOUNDARY MOVING INTO THE SOUTHEAST. AS FAR AS
RAIN CHANCES GO...EXPECT THE ACTIVITY OVER THE GULF TO SHIFT
SOUTHEAST THROUGH THE MORNING AND THEN WE WILL TRANSITION TO MORE
SEA-BREEZE/DIURNAL SHOWERS AND THUNDERSTORMS FOR THE AFTERNOON
HOURS...WITH THE BEST CHANCES OVER INLAND AREAS AS THE WEST COAST
SEA BREEZE FORMS AND SHIFTS INLAND. THE WEAK FRONTAL BOUNDARY WILL
SINK SOUTH INTO NORTHERN FLORIDA TONIGHT INTO EARLY FRIDAY WITH
MOSTLY QUIET CONDITIONS EXPECTED ACROSS THE FORECAST AREA. UPPER-
LEVEL RIDGING WILL START TO BUILD OVER THE GULF DURING THE DAY WITH
SURFACE HIGH PRESSURE CENTERED TO THE NORTHEAST. SHOWER AND
THUNDERSTORM ACTIVITY DURING THE AFTERNOON WILL BE FOCUSED MAINLY
OVER SOUTHWEST FLORIDA. AS FAR AS TEMPERATURES...STILL LOOKING AT
ABOVE NORMAL VALUES TO END THE WEEK.
.LONG TERM (FRIDAY NIGHT-THURSDAY)...
CUT-OFF U/L LOW WILL MOVE OVER NEW ENGLAND WITH THE TROUGH AXIS
WELL OFF THE EASTERN SEABOARD. WEST COAST TROUGH WILL PERSIST WITH
BROAD RIDGING DOWNSTREAM OVER THE GULF OF MEXICO WITH A RIDGE AXIS
NORTH THROUGH THE TENNESSEE VALLEY. AN U/L DISTURBANCE WILL BE
EJECTED EAST ACROSS THE MID/LOWER MISSISSIPPI VALLEY FRIDAY NIGHT
TO THE TENNESSEE VALLEY ON SATURDAY. ONSHORE WESTERLY BOUNDARY
LAYER FLOW ACROSS THE FLORIDA PENINSULA WILL PUSH THE WEST COAST
SEA BREEZE BOUNDARY INLAND RATHER QUICKLY...WHICH WILL KEEP MOST
AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY EAST OF THE FORECAST
AREA.
U/L ENERGY OVER THE PACIFIC NORTHWEST WILL SINK SOUTHEAST AND CUT-
OFF OVER THE FOUR CORNERS AREA SUNDAY WITH STRONG U/L QUASI-ZONAL
FLOW PERSISTING ACROSS THE SOUTHERN TIER OF THE U.S. A WEAK FRONTAL
BOUNDARY WILL STALL ACROSS THE SOUTHEAST U.S. WITH DEEP TROPICAL
MOISTURE SOUTH OF THE BOUNDARY ACROSS THE FLORIDA PENINSULA. A WEAK
U/L DISTURBANCE WILL TRACK ACROSS THE FLORIDA PENINSULA SUNDAY WITH
A CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS MAINLY NORTH OF THE
TAMPA BAY AREA AND OVER THE INTERIOR. THE U/L LOW OVER THE
SOUTHWEST U.S. WILL BEGIN TO OPEN UP AND PUSH EAST ACROSS THE
SOUTHERN PLAINS MONDAY WHICH WILL INDUCE WEAK U/L RIDGING OVER THE
GULF OF MEXICO. COMBINATION OF DAYTIME HEATING AND SUFFICIENT DEEP
LAYER MOISTURE AND WEAK ATMOSPHERIC INSTABILITY WILL CREATE A CHANCE
OF AFTERNOON SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA
MONDAY AFTERNOON.
COMPLEX PATTERN TAKING SHAPE MIDDLE OF NEXT WEEK AS THE U/L LOW
MOVING OUT OF THE SOUTHERN PLAINS MAY BE ABSORBED BY NORTHERN STREAM
ENERGY OVER THE MID MISSISSIPPI RIVER VALLEY ON TUESDAY. THIS WILL
CREATE GOOD U/L DIFFLUENCE OVER THE LOWER MISSISSIPPI VALLEY WITH AN
AREA OF LOW PRESSURE DEVELOPING AND PUSHING SLOWLY EAST TO THE
SOUTHEAST U.S. ON WEDNESDAY. HIGH DEGREE OF UNCERTAINTY ON THIS
EVOLVING SYSTEM AS THE U/L PATTERN SUGGESTS A DIGGING STRONG U/L
DISTURBANCE APPROACHING THE SOUTHEAST U.S. WITH STRONG DYNAMICS/LIFT
DEVELOPING OVER WEST CENTRAL AND SOUTHWEST FLORIDA TUESDAY NIGHT AND
WEDNESDAY. A COLD FRONT WILL MOVE ACROSS THE EASTERN GULF OF MEXICO
AND THE FLORIDA PENINSULA TUESDAY NIGHT AND WEDNESDAY WITH
SHOWERS/THUNDERSTORMS LIKELY DEVELOPING AHEAD OF THE FRONT AND
SPREADING OVER THE FORECAST AREA WITH A FEW STRONG STORMS POSSIBLE
WITH LOCALLY HEAVY RAIN.
U/L ENERGY WILL LIFT RAPIDLY NORTHEAST ON THE EAST SIDE OF THE L/W
TROUGH WEDNESDAY NIGHT AND THURSDAY WITH THE SURFACE LOW LIFTING TO
THE MID ATLANTIC COAST. DRIER COOLER AIR WILL ADVECT ACROSS WEST
CENTRAL AND SOUTHWEST FLORIDA IN THE WAKE OF THE COLD FRONT.
&&
.AVIATION... CLUSTER OF SHOWER AND STORMS MOVING ASHORE WILL IMPACT
KTPA/KPIE/KLAL THIS MORNING WITH POTENTIAL BRIEF HEAVY DOWNPOURS.
TERMINALS SOUTH OF I-4 CORRIDOR SHOULD SEE A CONTINUATION OF VFR
CONDITIONS THIS MORNING...FOLLOWED BY A CHANCE FOR AFTERNOON STORMS
DEVELOPING ALONG THE SEA BREEZE.
&&
.MARINE...
SHOWERS AND THUNDERSTORMS ARE POSSIBLE OVER THE COASTAL WATERS
TODAY...BUT OTHERWISE EXPECT BENIGN CONDITIONS TO CONTINUE
THROUGH THE FIRST PART OF THE WEEKEND WITH NO HEADLINES EXPECTED.
WINDS WILL INCREASE BRIEFLY LATE SATURDAY NIGHT INTO SUNDAY...BUT
THEN DIMINISH AGAIN FOR EARLY NEXT WEEK.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS AS RELATIVE HUMIDITY VALUES WILL REMAIN
ABOVE CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 85 73 89 72 / 40 20 20 0
FMY 88 72 89 73 / 50 20 30 10
GIF 88 70 88 71 / 50 20 20 10
SRQ 83 71 86 70 / 40 30 10 0
BKV 86 66 88 66 / 30 20 10 0
SPG 84 75 86 75 / 40 30 10 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...05/CARLISLE
LONG TERM/DECISION SUPPORT...13/OGLESBY
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
613 AM CDT THU APR 23 2015
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 416 AM CDT THU APR 23 2015
SPLIT UPPER SYNOPTIC FLOW LEFT WESTERN KANSAS UNDER A WEAK FLOW
ALOFT AS SURFACE HIGH PRESSURE CONTINUED TO SLIDE EAST INTO THE
MISSISSIPPI VALLEY. TO THE SOUTH, SCATTERED CONVECTION WAS DECAYING
ALONG A STATIONARY FRONT NEAR THE RED RIVER VALLEY AS EASTERLY
SURFACE FLOW AND BOUNDARY LAYER COOLING CONTRIBUTED TO THE EXPANSION
OF STRATUS ACROSS THE PANHANDLES AND CENTRAL AND WESTERN KANSAS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM CDT THU APR 23 2015
THE NAM CONTINUE TO EXPAND THE STRATUS ACROSS THE ENTIRE AREA THIS
MORNING LEADING TO CLOUD BASES BETWEEN 2 AND 3 KFT DURING THE DAY.
INTENSE LATE APRIL INSOLATION SHOULD AID BOUNDARY LAYER MIXING,
EFFECTIVELY ERODING THE EXTREME WESTERN EDGE ALTHOUGH THE EXTENT TO
HOW FAR EAST THE STRATUS SCATTERS IS UNCERTAIN. DRY MID LEVELS MAY
CONTRIBUTE TO A DRIZZLE SETUP BETWWEEN ROUGHLY HIGHWAYS 83 AND 283
LATE THIS MORNING AND SPREADING EAST IN THE AFTERNOON. HIGHER
TERRAIN SURFACE BASED CONVECTION IS EXPLICITLY DEVELOPED BY THE 4 KM
NAM ACROSS SOUTHEAST COLORADO LATE IN THE DAY, AND DRIVEN EAST IN
THE HIGH (30-40 KNOT) SHEAR ENVIRONMENT BY THE EVENING, BUT TO A
MUCH MORE STABLE BOUNDARY LAYER IN KS. AT THE SAME TIME, THE
EVOLUTION OF THE UPPER PATTERN SUGGESTS A 700 MB TROUGH MOVING INTO
THE REGION, SETTING UP AN ISENTROPIC LIFT ZONE FOR THE OVERNIGHT,
WHICH MAY BE FAIRLY LIMITED GIVEN THE DRY MID LEVELS.
MOS/BLENDS FORECASTS UPPER 50S WITH MODELS SHOWING CLOSER TO 70 IN
THE AREA OF MORE ABUNDANT SUN TODAY. UNCERTAINTY WILL THEN INCREASE
INTO TONIGHT AS THE EFFECTS OF ANY POTENTAIL CONVECTION COULD
IMPACT TEMPERATURES, AREAL EXTENT OF PRECIPITATION AND LEFTOVER RAIN
COOLED STRATUS OR FOG.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 334 AM CDT THU APR 23 2015
MAIN UNCERTAINTY ON FRIDAY WILL BE HOW FAR NORTH THE WARM FRONT
WILL BE BY LATE DAY AND WHERE THE MOISTURE RETURN AND LOW LEVEL
FORCING BE LOCATED FRIDAY EVENING. AT THIS TIME THE NAM AND NMM
SUGGESTS THAT BETTER MOISTURE RETURN WILL TO BE LOCATED EAST OF
HIGHWAY 283 WHILE THE GFS, AND ARW WERE MORE PROGRESSIVE AND MOVED
THE FRONT, DRYLINE, MOISTURE, AND BETTER INSTABILITY FURTHER EAST
INTO CENTRAL KANSAS. GIVEN THE UNCERTAINTY BETWEEN THE MODELS
EARLY THIS MORNING WILL STAY CLOSE TO THE PREVIOUS FORECAST FOR
PRECIPITATION CHANCES WHICH SEEMS TO BE A NICE BLEND BETWEEN THE
TWO EXTREMES LATE FRIDAY INTO FRIDAY NIGHT. ACROSS EXTREME
SOUTHWEST KANSAS FRIDAY AFTERNOON A WEST WIND WILL DEVELOP BY THE
EARLY AFTERNOON AND DEW POINTS ARE EXPECTED TO FALL BACK INTO THE
30S. THIS WILL RESULT IN INCREASE FIRE DANGER LEVELS, HOWEVER
GIVEN THE RECENT GREEN UP BASED ON THE FUEL STATUS PAGE CONDITIONS
DO NOT LOOK FAVORABLE FOR A FIRE WATCH AT THIS TIME.
AS AN UPPER LEVEL TROUGH CROSSES THE CENTRAL PLAINS FRIDAY NIGHT
AND A COLD FRONT WILL DROP SOUTH ACROSS NEBRASKA. THIS FRONT WILL
CONTINUE TO MOVE SOUTH ACROSS WESTERN KANSAS ON SATURDAY WHICH
WILL ALLOW SOME COOLER AIR TO MOVE INTO NORTHERN KANSAS BY LATE
DAY. AT THIS TIME BASED ON THE TIMING OF THIS FRONTAL PASSAGE
SATURDAY AFTERNOON ANOTHER UNSEASONABLY WARM DAY CAN BE EXPECTED
ACROSS MUCH OF SOUTHWEST KANSAS. ACROSS NORTH CENTRAL KANSAS
TEMPERATURES ARE EXPECTED TO BE ROUGHLY 8-10 DEGREE COOLER. HIGHS
ON SATURDAY WILL VARY FROM THE LOWER 70S ALONG I-70 CORRIDOR TO
THE LOWER 80S NEAR THE OKLAHOMA BORDER.
THE COLD FRONT WILL BECOME NEARLY STATIONARY SATURDAY NIGHT AND
EXTEND FROM SOUTHEAST COLORADO INTO WESTERN OKLAHOMA. WARM AIR
ADVECTION AND ISENTROPIC LIFT DEVELOPS NORTH OF THIS FRONT LATE
SATURDAY NIGHT/EARLY SUNDAY AS ANOTHER UPPER LEVEL SYSTEM DEEPENS
AS IT CROSSES THE FOUR CORNERS REGION. CLOUDS WILL INITIALLY BE ON
THE INCREASE FOLLOWED BY IMPROVING CHANCES OF PRECIPITATION LATE
THIS WEEKEND GIVEN EAST/SOUTHEASTERLY UP SLOPE FLOW, MOISTURE
NORTH OF THE STATIONARY FRONT AND IMPROVING ISENTROPIC LIFT AHEAD
OF THIS DEVELOPING UPPER LEVEL LOW.
CLOUDY SKIES, COOL TEMPERATURES AND HIGH CHANCES FOR
PRECIPITATION CAN THEN BE EXPECTED FROM THROUGH EARLY NEXT WEEK AS
THE UPPER LOW SLOWLY MOVES FROM NEW MEXICO, ACROSS TEXAS PANHANDLE
INTO OKLAHOMA EARLY NEXT WEEK. GIVEN THE LATEST TRACK OF THIS
UPPER LEVEL SYSTEM THE AREA MORE FAVORABLE FOR WIDESPREAD
PRECIPITATION WILL BE SOUTH OF HIGHWAY 156.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 611 AM CDT THU APR 23 2015
06Z NAM BUFR SOUNDINGS WERE SIMILAR TO THE 00Z MODEL RUNS WITH
MOISTURE AND WEAK LIFT INCREASING IN THE 900MB TO 750MB LEVEL
TODAY. BASED ON THE 06Z NAM BUFR SOUNDING ALONG WITH THE LATEST
HRRR AND RAP MVFR CEILINGS ARE EXPECTED TO LOWER INTO IFR CATEGORY
AT DDC AND GCK BETWEEN 15Z AND 18Z AS PATCHY DRIZZLE DEVELOPS. AT
HYS CEILINGS ARE EXPECTED TO FALL BACK INTO THE IFR CATEGORY
BETWEEN 21Z THURSDAY AND 00Z FRIDAY. AFTER 00Z FRIDAY THE CHANCE
FOR FOG WILL INCREASE AND STATUS WILL CONTINUE TO LOWER AS THE
SURFACE TO 900MB LEVEL SATURATES AND A SOUTHEAST WINDS CONTINUE AT
10 KNOTS OR LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 61 55 79 50 / 20 40 20 20
GCK 63 51 77 47 / 20 60 20 20
EHA 72 49 79 47 / 20 40 10 10
LBL 66 54 81 49 / 20 30 10 10
HYS 60 51 73 49 / 10 60 40 50
P28 61 54 81 52 / 10 50 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
802 AM MDT THU APR 23 2015
.UPDATE...
MADE A QUICK UPDATE TO STRETCH POPS FARTHER EAST THIS MORNING.
WEAK BAND OF SHOWERS FROM LIVINGSTON TO JUST NORTH OF COLUMBUS
HOLDING ON. THOUGH HRRR DOES WEAKEN THEM IN TIME...THEY HAVE BEEN
HOLDING ON TO THEIR STRENGTH THE LAST COUPLE OF HOURS. TWH
&&
.SHORT TERM...VALID FOR TDY AND FRI...
EARLY MORNING AREA OF SHOWERS MOVING THROUGH NORTHERN PORTIONS OF
SOUTHEAST MONTANA PRODUCING ONLY LIGHT RAIN BUT EXPECT ACTIVITY TO
PERSIST FOR A WHILE AFTER 12Z. FLATTER FLOW BEHIND THIS WAVE IS
CLEARING OUT SOUTH CENTRAL MONTANA BUT WATER VAPOR IMAGERY SHOWS A
DECENT AMOUNT OF MOISTURE IS LINGERING IN PLACE BEHIND THE SYSTEM.
NOT MUCH IN THE WAY OF FORCING TODAY BUT PRECIPITABLE WATERS .50
TO .75 WILL COMBINE WITH DIURNAL WARMING TO ALLOW FOR SOME SHOWER
ACTIVITY WITH THE MOUNTAINS BEING FAVORED. A THUNDERSTORM OR TWO
CANNOT BE RULED OUT BUT ANY CELL MOVEMENT SHOULD BE PRETTY SLOW SO
EXPECT MOST CELLS TO REMAIN AS RAIN SHOWERS. TEMPERATURES WILL BE
COOLER TODAY WITH THE FLATTER FLOW ALOFT.
BROADER HEIGHT FALLS UPSTREAM OVERNIGHT OVER WASHINGTON AND BC
TURN THE FLOW ALOFT SOUTHWESTERLY. THE INITIAL HEIGHT RISES OVER
THE AREA ASSOCIATED WITH THIS PROCESS WILL STABILIZE THE AIRMASS
AFTER MIDNIGHT WHICH WILL BRING CLEARING AND ALLOW FOR A BIT
COOLER TEMPERATURES OVERNIGHT.
FRIDAY THE FLOW ALOFT BECOMES SLIGHTLY DIFFLUENT OVER THE AREA
WHICH ALLOWS A SURFACE TROUGH TO DEVELOP ALONG THE FOOTHILLS. THIS
ALLOWS MOISTURE TO DEEPEN AND SET UP A BETTER CHANCE FOR SHOWERS
OVER THE MOUNTAINS. BY AFTERNOON AND EVENING A DISTURBANCE ROTATES
THROUGH SOUTHWEST MONTANA AND THIS BRINGS A MUCH BETTER CHANCE FOR
SHOWER ACTIVITY WITH INCREASING MID LEVEL WINDS. THIS WILL SPEED
UP STORM MOVEMENT AND ALLOW SHOWERS TO BEGIN SPREADING INTO THE
PLAINS. AT THE SAME TIME A COOL FRONT BEGINS MOVING ACROSS THE
AREA FRIDAY NIGHT WHICH PROVIDES A BETTER TRIGGER FOR SHOWERS AND
ISOLATED THUNDERSTORMS. HAVE INCREASED POPS ESPECIALLY FOR FRIDAY
NIGHT AFTER MIDNIGHT AS MODELS ARE PRETTY CONSISTENT WITH THIS
EVOLUTION AND SREF PLUMES ARE ADVERTISING .30 INCHES OF PRECIP FOR
BILLINGS AREA. BORSUM
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
SATURDAY WILL BEGIN WITH A WEAK SHORTWAVE IN OUR CENTRAL PARTS
MOVING TOWARD THE EAST IN SW FLOW ALOFT. GOOD CHANCE OF SHOWERS
ALONG INVERTED TROF ACROSS OUR EAST AND HAVE RAISED POPS.
SUBSIDENCE ALONG WITH LOW LEVEL DRYING WILL LIMIT PCPN CHANCES
BEHIND THIS WAVE...UNTIL UPPER DIVERGENCE BEGINS TO INCREASE AGAIN
IN OUR FAR WEST PER APPROACHING DEEPER LOW. HAVE REDUCED POPS AND
TAKEN OUT THUNDER ACROSS OUR CENTRAL PARTS ON SATURDAY. THIS
INCLUDES BILLINGS WHICH SHOULD ONLY SEE A CHANCE OF SHOWERS EARLY
IN THE DAY. TEMPS WILL BE SEASONAL WITH HIGHS IN THE UPPER 50S TO
MID 60S.
LOW OVER THE PAC NW SATURDAY WILL DRIVE TOWARD THE CENTRAL AND
SOUTHERN ROCKIES SUNDAY. MODELS IN SOME DISAGREEMENT IN PATH OF
MID LEVEL LOW AND PCPN CHANCES IN OUR CWA...WITH THE GFS SHOWING A
FAIRLY WET UPSLOPE EVENT TRANSITIONING TO OUR SOUTHEAST SATURDAY
NIGHT THROUGH SUNDAY. THE ECMWF SUGGESTS WE WILL BE MORE DOMINATED
BY THE NORTHERN WEAKER SPLIT WITH LESS LOW LEVEL MOISTURE
ADVECTION...AND IS THUS DRIER. WILL LEAN TOWARD THE CONSENSUS/
SREF AND KEEP HIGH POPS ESPECIALLY FOR OUR SOUTHERN TIER THESE
PERIODS. PCPN AMOUNTS ON THE ORDER OF A HALF INCH POSSIBLE IN
THESE AREAS AND COULD SEE SOME WET SNOWFALL FOR THE FOOTHILLS
INCLUDING LIVINGSTON...RED LODGE AND STORY AS 850MB TEMPS MAY
APPROACH +1C WITH DYNAMIC COOLING...WARMER IF THE EC VERIFIES OF
COURSE. DO NOT SEE A HIGH IMPACT THREAT HERE JUST SOME MUCH-NEEDED
PCPN AND SOME SNOW OVER THE NORTH ASPECTS OF THE MOUNTAINS. SYSTEM
WILL CONTINUE TO DRIVE SOUTHWARD AND OUR PCPN POTENTIAL WILL
DIMINISH SUNDAY NIGHT AS DRIER NW FLOW TAKES OVER. TEMPS ON SUNDAY
LOOK TO BE THE COOLEST OF THE EXTENDED PERIOD WITH UPPER 40S AND
50S FOR HIGHS.
UPPER RIDGE WITH ABOVE NORMAL HEIGHTS WILL BRING US DRY AND WARMER
WEATHER MONDAY THROUGH WEDNESDAY...THOUGH MODELS DIVERGE HORRIBLY
WITH RESPECT THE OVERALL AMPLITUDE OF THE FLOW ACROSS THE EASTERN
PACIFIC AND CONUS. CONFIDENCE IS HIGH THAT OUR WX WILL BE DRY.
BIGGER QUESTION IS HOW WARM IT WILL GET AND HOW FAST. GFS SUGGESTS
A COUPLE DAYS OF EAST WINDS WHEREAS THE FLATTER ECMWF CREATES
STRONGER DOWNSLOPE WARMING. EITHER WAY WE SHOULD SEE TEMPS GET
BACK INTO THE 70S BY THE MIDDLE OF NEXT WEEK...WITH 80S ALSO
POSSIBLE.
JKL
&&
.AVIATION...
ISOLATED TO SCATTERED SHOWERS WILL AFFECT THE REGION TODAY AND
TONIGHT WITH LOCAL MVFR AND SOME MOUNTAIN OBSCURATIONS POSSIBLE.
VFR FLIGHT CONDITIONS WILL PREVAIL OTHERWISE. THERE IS POTENTIAL
FOR A FEW TSTMS THIS AFTERNOON AND EVENING. JKL
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 065 044/069 043/063 039/055 038/068 042/072 044/076
2/T 22/T 63/W 66/W 31/B 00/B 00/U
LVM 065 038/064 037/059 035/053 031/067 037/073 039/075
4/T 34/T 64/T 76/W 31/B 00/B 00/B
HDN 068 040/072 040/065 039/054 038/067 037/073 040/076
2/T 21/B 54/W 56/W 41/B 00/B 00/U
MLS 067 038/071 041/062 040/056 039/066 037/070 041/073
2/T 11/B 37/W 46/W 51/B 10/B 00/U
4BQ 069 040/070 041/062 040/055 039/063 037/069 039/072
2/T 21/B 25/T 47/W 61/B 10/B 00/U
BHK 065 035/067 039/059 040/055 038/062 037/065 037/069
2/T 11/B 17/W 46/W 52/W 10/B 00/B
SHR 065 039/067 039/061 037/050 036/064 036/069 038/072
2/T 23/T 42/W 47/W 51/B 00/B 00/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
637 AM CDT THU APR 23 2015
.UPDATE...
ISSUED AT 637 AM CDT THU APR 23 2015
THE 06Z NAM CAME IN STILL TRYING TO INITIATE TSTMS OVER SW NEB
THIS MORNING. THIS AS INCREASING LOW-LVL MOISTURE CREATES
ELEVATED INSTABILITY. THE 08Z HRRR DOESN`T HAVE IT AND THAT
BOLSTERS OUR CONFIDENCE IN KEEPING THE FCST DRY.
AFTER REVIEWING MORE DATA FOR THE 12Z TAFS...INSERTED A MENTION OF
FOG IN THE FCST LATE TONIGHT INTO FRI AM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CDT THU APR 23 2015
ALOFT: SPLIT FLOW CONTS BUT THE FCST AREA WILL BE MORE AFFECTED
BY THE SRN STREAM OVER THE NEXT 24 HRS. TWO UPR LOWS WERE OVER SRN
CA AND W OF THE BAJA PENINSULA. THESE LOWS WILL FILL AND
CONSOLIDATE AND PROGRESS THRU THE SW USA...WITH A +TILT TROF
EXTENDING FROM CO-AZ BY 12Z/FRI. IN THE MEANTIME...THE W FLOW
ALOFT OVER THE CNTRL PLAINS WILL BECOME ANTICYCLONIC AND
EVENTUALLY TURN SW.
SURFACE: HIGH PRES HAS DRIFTED INTO THE MS VALLEY AND WILL REMAIN
E OF THE REGION THRU TONIGHT. THE PRIMARY POLAR FRONT WILL REMAIN
OVER THE SRN PLAINS BUT BEGIN LIFTING N AS A WARM FRONT TONIGHT
...IN RESPONSE TO FALLING PRES WITHIN THE STRENGTHENING LEE TROF
AND EVENTUAL CYCLOGENESIS.
TODAY: GRADUALLY BECOMING CLOUDY. SATELLITE SHOWS STRATUS FORMING
AND EXPANDING ON THE COOL SIDE OF THE FRONT OVER NRN TX/OK/KS...
WITHIN A PLUME OF MODESTLY RICH LOW-LVL MOISTURE. THIS PLUME AND
THE STRATUS WILL OVERTAKE THE FCST AREA FROM SW-NE AND KEEP TEMPS
FROM REACHING THEIR MAX POTENTIAL.
QPF: ALL MODEL GRID-SCALE AND/OR CONVECTIVE PRECIP SCHEMES ARE
OUTPUTTING LIGHT QPF TODAY. JUST DON`T SEE IT HAPPENING GIVEN THE
LACK OF FORCING AND OVERALL RIDGING/SUBSIDENCE ALOFT. FCST
SOUNDINGS DON`T HAVE THE LOOK OF SPRINKLES EITHER. SO THEY WERE
WITHDRAWN FROM THE FCST. BELIEVE THE 00Z WRF-NMM DEPICTION IS MOST
LIKELY TO VERIFY. TODAY IS QUIET AND DRY THEN SCT TSTMS WILL
DEVELOP TO THE W LATE AFTERNOON WITHIN THE LEE TROF AND THEY
SHOULD PROPAGATE E AND BE MAINTAINED AS THEY ACCESS THE LLJ/WAA
AND GREATER LOW-LVL MOISTURE. NEW TSTMS MAY ALSO DEVELOP WITHIN
THE LLJ. BEST CHANCE FOR RAIN PER SREF QPF PROBABILITIES WILL BE
OVER N-CNTRL KS UP INTO THE SUPERIOR-HEBRON AREA.
INSTABILITY FROM THE 03Z SREF WILL BE ENOUGH TO SUPPORT THUNDER
FOR THE ENTIRE FCST AREA...BUT MUCAPE WILL BE UNDER 750 J/KG OVER
S- CNTRL NEB AND NOT EVEN REACH 1000 J/KG OVER N-CNTRL KS.
EFFECTIVE SHEAR WILL BE AROUND 25 KTS. SO RISK FOR EVEN A STRONG
TSTM APPEARS LIMITED.
TONIGHT: CLOUDY. SCT SHWRS/TSTMS. NOT EVERY LOCATION WILL SEE
THEM. THERE IS PLENTY OF UNCERTAINTY ON COVERAGE OF SHWRS/TSTMS.
CURRENTLY HAVE HIGHEST PROBABILITIES SE OF THE TRI-CITIES.
NUDGED LOW TEMPS ROUGHLY 3F ABOVE THE PREVIOUS FCST DUE TO
EXPECTED CLOUD COVER.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 359 AM CDT THU APR 23 2015
THE MAIN FOCUS IS ON TSTMS FRIDAY AND FRIDAY NIGHT.
ON FRIDAY...THE PATTERN ALOFT WILL FEATURE SOUTHWEST FLOW ACROSS
THE CENTRAL PLAINS WITH A LEAD SHORTWAVE TROUGH LIFTING ACROSS OUR
REGION AHEAD OF A DEEPER SHORTWAVE NEAR THE FOUR CORNERS REGION.
PCPN IS EXPECTED TO BE ONGOING/LINGERING INTO THE DAY ON FRIDAY
WITH THE PASSING LEAD WAVE...WITH REDEVELOPMENT OF RAIN SHOWERS
AND THUNDERSTORMS EXPECTED FRIDAY AFTERNOON/EVENING AND CONTINUING
THRU FRIDAY NIGHT AS THE SOUTHERN DEEPER TROUGH LIFTS OUT ACROSS
THE CENTRAL PLAINS.
CANNOT RULE OUT THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS
PRIMARILY ACROSS KANSAS INTO THE SOUTHERN PORTION OF NEBRASKA
FRIDAY AFTN/EVE. THE FIRST PART OF THE DAY ON FRIDAY WILL LIKELY
SEE REMNANT/DEPARTING CONVECTION AND A FAIR AMOUNT OF CLOUD COVER.
BREAKS IN THE CLOUDS ARE EXPECTED ACROSS OUR SOUTHERN AND WESTERN
ZONES HEADING INTO THE AFTERNOON AND A MOISTURE AXIS WITH SFC DPS
IN THE MID 50S ARE FORECAST TO ALIGN ACROSS THE EASTERN HALF OF
KANSAS INTO SOUTHEAST NEB WITH INSTABILITY PROGGED TO INCREASE TO
AROUND 1500 J/KG OR SO BY EVENING ACROSS OUR SOUTHERN ZONES.
STORMS ARE EXPECTED TO INITIATE ALONG/AHEAD OF THE SFC TROUGH AND
DRY LINE AND WARM FRONTAL BOUNDARY. SHEAR PROGS AVERAGE 30KTS AND
COMBINED WITH THE INSTABILITY...THE PRIMARY HAZARDS FROM THE
STORMS WILL BE LARGE HAIL/DAMAGING WINDS THRU THE EVENING
HOURS...WITH CHCS FOR SEVERE STORMS DECREASING OVERNIGHT.
ON SATURDAY...A FEW SHOWERS MAY LINGER IN THE MORNING UNTIL THE
UPPER LOW PASSES FARTHER TO THE EAST...THEN THE FORECAST DRIES OUT
FOR THE REMAINDER OF THE DAY. HEIGHTS RISE BEHIND THE DEPARTING
SYSTEM IN SHORTWAVE RIDGING IN BETWEEN ANOTHER TROUGH MOVING INTO
THE CENTRAL ROCKIES.
THERE REMAINS A FAIR AMOUNT OF UNCERTAINTY IN HANDLING THE UPPER
LOW IN THE ROCKIES OVER THE WEEKEND WITH THE GFS LIFTING OUT THE
SYSTEM FARTHER NORTH THAN THE ECMWF AND GFS ENSEMBLE. HAVE
MAINTAINED SOME BUFFER LOW POPS FOR OUR WESTERN COUNTIES SATURDAY
NIGHT BUT IN GENERAL HAVE LOWERED POPS FROM SUNDAY THROUGH TUESDAY
WITH MODELS BEGINNING TO FAVOR A MORE SOUTHERN SOLUTION.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z FRI MORNING)
ISSUED AT 637 AM CDT THU APR 23 2015
TODAY: VFR TO START BUT STRATUS IS EXPANDING ACROSS KS AND WILL BE
LIFTING INTO THE TERMINALS. CURRENT TIMING OF ARRIVAL IS 17Z-18Z.
SE WINDS WILL INCREASE AND GUST UP TO 25 KTS. CONFIDENCE: MEDIUM
DUE TO UNCERTAINTY ON TIMING STRATUS AND HEIGHT OF CIGS.
TONIGHT: CIGS DEGRADE TO MVFR AND IFR. ALL FCST GUIDANCE IS IN
UNISON THAT CIGS LOWER TO 300-500 FT WITH MVFR VSBYS. SCT SHWRS/
TSTMS AFTER 06Z. SE WINDS WILL REMAIN GUSTY. CONFIDENCE: MEDIUM TO
DUE UNCERTAINTY ON TIMING OF CIG HEIGHT CHANGES AND MAGNITUDE OF
VSBYS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...HALBLAUB
LONG TERM...FAY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
355 PM EDT THU APR 23 2015
.SYNOPSIS... 19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A COMPLEX
UPPER LEVEL PATTERN ACROSS THE CONUS. SPLIT FLOW ARRIVES OVER
NORTHERN CALIFORNIA WITH ONE BRANCH PUSHING INTO SOUTH-CENTRAL
CANADA AND ANOTHER CARVING A DEEP TROUGH THROUGH THE DESERT
SOUTHWEST/BAJA REGION. FURTHER EAST DOWNSTREAM WE FIND A DEEP AND
UNSEASONABLY COLD TROUGH IN PLACE ACROSS THE GREAT
LAKES/NORTHEASTERN STATES. SOUTHERN STREAM FLOW IS MOVING NORTH OUT
OF THE TROPICAL PACIFIC TO THE EAST OF THE BAJA TROUGH AND THEN
BECOMING MORE ZONAL AS TO MOVES OVER THE NORTH-CENTRAL GULF
COAST...INCLUDING THE FLORIDA PENINSULA.
AT THE SURFACE...A WEAK SURFACE BOUNDARY THAT SET UP ACROSS THE
NORTHEAST GULF OF MEXICO HAS BEEN THE FOCUS FOR PERSISTENT SHOWERS
AND THUNDERSTORM MOVING ASHORE TODAY. THE AREAS EFFECTED HAVE
SHIFTED THROUGH THE DAY...BUT WE HAVE NOW SEEN DECENT RAINFALL FOR
JUST ABOUT EVERYONE...WITH THE EXCEPTION OF PARTS OF LEE/CHARLOTTE
COUNTIES...AND ALSO LEVY COUNTY. THE CURRENT CONVECTIVE BAND EXTENDS
FROM THE MANATEE/SARASOTA COASTS INLAND THROUGH DESOTO AND SOUTHERN
HIGHLANDS COUNTIES. RADAR SHOWS A DEFINED OUTFLOW BOUNDARY HAS
SHIFTED SOUTH FROM THIS CONVECTIVE BAND AND APPEARS TO BE SLOWLY IN
INFLOW. CONVECTIVE ORGANIZATION AND STRENGTH OF THE CELLS HAS BEEN
ON THE DECLINE DURING THE PAST HOUR...AND EXPECT THIS TREND TO
CONTINUE INTO THE EARLY EVENING. FROM PINELLAS/HILLSBOROUGH/POLK
COUNTIES NORTHWARD THE RAINFALL HAS COME TO AN END...AND A DECENT
EVENING WEATHERWISE APPEARS IN STORE.
&&
.SHORT TERM (TONIGHT THROUGH FRIDAY)...
REST OF TODAY AND TONIGHT... BAND OF SHOWER AND ISOLATE STORMS WILL
CONTINUE TO BECOME LESS ORGANIZED INTO THE EVENING AS IT SINKS
ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. HAVE HIGHEST RAIN
CHANCES SOUTH OF THE TAMPA BAY AREA...WITH LITTLE TO NO ADDITIONAL
RAINFALL EXPECTED FOR THE I-4 CORRIDOR AND NORTHWARD. ALTHOUGH
ANOTHER STRONG STORM OR TWO CAN NOT BE RULED OUT ACROSS THE SOUTHERN
HALF OF THE AREA...THE THREAT FOR SEVERE WEATHER APPEARS TO BE
RAPIDLY DECLINING AS WELL.
ONCE THIS BAND OF STORMS DISSIPATES LATER THIS EVENING...AM
ANTICIPATING A GENERALLY DRY AND SEASONABLE OVERNIGHT PERIOD AS HIGH
PRESSURE BEGINS TO BUILD IN FROM THE NORTH. THERE MAY BE A BIT OF
FOG LATE AT NIGHT ACROSS THE INTERIOR...BUT SIGNIFICANT COVERAGE OR
VISIBILITY RESTRICTIONS ARE NOT EXPECTED AT THIS TIME. LOW
TEMPERATURES TONIGHT GENERALLY IN THE 60S...WITH LOWER 70S ALONG THE
IMMEDIATE COAST FROM TAMPA BAY SOUTHWARD.
FRIDAY IS SHAPING UP TO BE A MUCH QUIETER DAY IN TERMS OF
THUNDERSTORMS. THE DEEP LAYER MOISTURE WILL HAVE BEEN SCOURED OUT
FOR THE MOST PART MAKING THE COLUMN MORE HOSTILE TOWARD DEEP
CONVECTION. IN ADDITION...MID-LEVEL TEMPS ARE FORECAST BY THE
GUIDANCE SUITE TO BE 2-3 DEGREES WARMER ON FRIDAY THAN THEY ARE
TODAY. ALL THIS SUGGESTS A GENERALLY INACTIVE SEA BREEZE
THUNDERSTORM PATTERN. HIRES GUIDANCE ENSEMBLES SUGGEST A FEW WIDELY
SCT STORMS LATE IN THE DAY ALONG THE SEA-BREEZE...GENERALLY SOUTH OF
THE TAMPA BAY AREA. WILL HAVE 20-30% POPS AFTER 19-20Z SOUTH OF
TAMPA BAY FOR THIS POTENTIAL...HOWEVER ANY STORMS SHOULD BE BRIEF IN
DURATION AND LIFE CYCLE GIVEN THE MORE HOSTILE COLUMN ALOFT.
AFTERNOON TEMPERATURES RISING WELL INTO THE 80S FOR MOST
SPOTS...WITH EVEN SOME LOWER 90S ACROSS THE SOUTHERN ZONES.
&&
.LONG TERM (SATURDAY THROUGH NEXT THURSDAY)... SAT-SUN...UPPER LEVEL
RIDGING ACROSS THE AREA FLATTENS AS A SHORT WAVE TROUGH TRACKS
ACROSS THE OHIO VALLEY AND CROSSES THE MID-ATLANTIC STATES.
MEANWHILE A FRONT SAGS IN ALONG THE GULF COAST AND THROUGH THE SE
U.S. AS IT WEAKENS...ATLANTIC HIGH PRESSURE RIDGES IN ACROSS AND
SOUTH OF THE SOUTHERN HALF OF FL.
MON-TUE...AN UPPER TROUGH/LOW MOVES OUT OF THE FOUR CORNERS REGION
TO THE EASTERN PLAINS WITH WEAK RIDGING CONTINUING ACROSS THE GULF
REGION. THE FRONT IN THE SE U.S. SETTLES INTO FL. THE ECMWF HAS A
BROAD BOUNDARY ACROSS CENTRAL FL WHILE THE GFS IS MORE CONCENTRATED
IN THE NORTHERN HALF OF THE STATE.
WED-THU...THE UPPER TROUGH BROADENS OVER THE EASTERN CONUS AS IT
DROPS DOWN INTO THE GULF THEN SLIDES EAST..MORE SLOWLY IN THE ECMWF
WHILE THE GFS IS FASTER WITH A SLIGHTLY SHARPER TROUGH. AT THE
SURFACE LOW PRESSURE MOVES EAST WITH A TRAILING COLD FRONT. HERE THE
ECMWF AND GAS ARE SIMILAR WITH THE TIMING ALTHOUGH THE ECMWF HAS THE
LOW IN THE GULF AND MOVING ACROSS FL WHILE THE GFS KEEPS THE LOW IN
THE GULF COASTAL AND SOUTHERN STATES.
EXPECT SOME LOW POPS WITH SHOWERS AND A FEW THUNDERSTORMS MAINLY
NORTH AND INTERIOR INTO EARLY MON. RAIN CHANCES THEN GRADUALLY
INCREASE THROUGH MIDWEEK WITH SOME STRONG STORMS AND HEAVY RAIN
POSSIBLE. SHOWERS AND STORMS THEN TREND DOWN FOR THE END OF THE
PERIOD. TEMPERATURES WILL START OFF ABOVE NORMAL THEN SLOWLY
DECREASE TO NEAR NORMAL...WITH THE NORTH SLIGHTLY BELOW.
&&
.AVIATION... BAND OF CONVECTION STRETCHING FROM NEAR KSRQ TO LAKE
OKEECHOBEE WILL CONTINUE TO SLOWLY SINK SOUTHWARD INTO THE EARLY
EVENING. HAVE INCLUDED VCTS FOR KPGD...BUT APPEARS UNLIKELY THIS
LINE OF STORMS WILL REACH KFMY/KRSW. NORTH OF THE BAND FOR THE I-4
CORRIDOR TERMINALS...IT APPEARS THAT THE CONVECTION HAS FINALLY COME
TO AN END. THEREFORE VIS/CIG RESTRICTIONS WILL BE POSSIBLE FOR
KSRQ/KPGD THE NEXT SEVERAL HOURS...BUT THEREAFTER WILL BE
FORECASTING VFR THROUGH REMAINDER OF THE TAF PERIOD.
&&
.MARINE... A WEAK BOUNDARY OVER THE NORTHEAST GULF OF MEXICO WEAKENS
TONIGHT AS HIGH PRESSURE ATTEMPTS TO BUILD IN FROM THE NORTH. THIS
RIDGE SLIDES SOUTH TO THE FLORIDA STRAITS BY SATURDAY. WINDS AND
WAVES ARE GENERALLY EXPECTED TO REMAIN BELOW 15 KNOTS THROUGH THE
WEEKEND.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS AS RELATIVE HUMIDITY VALUES WILL REMAIN
ABOVE CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 72 87 73 87 / 10 10 10 0
FMY 73 90 73 89 / 10 30 10 0
GIF 69 88 71 89 / 20 20 0 30
SRQ 71 84 73 86 / 10 10 10 0
BKV 66 88 66 88 / 10 20 0 10
SPG 74 86 75 85 / 10 10 10 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/AVIATION/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT SERVICES...RUDE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
310 PM MDT THU APR 23 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 112 PM MDT THU APR 23 2015
LOW CLOUDS THAT WERE PRESENT ACROSS THE AREA DURING THE MORNING
HOURS CONTINUED TO LINGER FOR SOME LOCATIONS ACROSS THE TRI STATE
AREA IN THE EARLY AFTERNOON ON VISIBLE SATELLITE IMAGERY...HOWEVER
MOST LOCATIONS WERE UNDER PARTLY TO MOSTLY CLEAR SKIES. RAP 500 MB
ANALYSIS AND WATER VAPOR IMAGERY SHOWED A SHORTWAVE TROUGH ACROSS
THE CENTRAL HIGH PLAINS REGION...HOWEVER A LONGWAVE TROUGH ACROSS
THE GREAT BASIN REGION WAS MOVING EASTWARD INTO THE CENTRAL HIGH
PLAINS.
THE ADVANCING TROUGH WILL BRING SOME POCKETS OF HIGHER POTENTIAL
VORTICITY VALUES ACROSS THE TRI STATE AREA LATER THIS AFTERNOON AND
TONIGHT...WHICH WILL HELP DESTABILIZE THE ATMOSPHERE AND CAUSE
STORMS TO DEVELOP. A SURFACE STATIONARY BOUNDARY TO THE WEST ALONG
THE COLORADO FRONT RANGE WILL ALSO PROVIDE THE NEEDED PUSH AT THE
SURFACE TO GET STORMS GOING. MOST MODEL GUIDANCE HAS INITIATION
OCCURRING SOMETIME BETWEEN 21 AND 00Z IN EASTERN COLORADO WITH
STORMS GETTING GOING BY 00Z. PROFILE CAPE BETWEEN 1000 AND 1500
J/KG AND BULK SHEAR BETWEEN 30 AND 35 KTS MAY BE ENOUGH TO CAUSE
SOME STORMS TO PRODUCE LARGE HAIL...AND DRY MID LEVELS IN MODEL
SOUNDINGS WITH DCAPE BETWEEN 800 AND 1000 J/KG COULD RESULT IN
DAMAGING WINDS GUSTS. THE SHEAR VALUES DIMINISH OVERNIGHT...BUT
CAPE WILL STILL BE PRESENT OVERNIGHT AS STORMS MOVE EASTWARD.
THEREFORE...EXPECTING STORMS TO CONTINUE OVERNIGHT FOR SOME
LOCATIONS.
THE SURFACE STATIONARY FRONTAL BOUNDARY WILL REMAIN DRAPED ACROSS
THE TRI STATE AREA OVERNIGHT...WHICH WILL BRING SOUTHEAST WINDS AT
THE SURFACE AND INCREASED RELATIVE HUMIDITIES OVERNIGHT. AS A
RESULT...FOG WILL DEVELOP AND CLOUD COVER WILL REMAIN INCREASED
OVERNIGHT. EXPECTING LOW TEMPERATURES TO BE SLIGHTLY WARMER AS A
RESULT OF THE BLANKETING CLOUD COVER IN THE UPPER 40S.
FOG AND LOWER CLOUDS WILL BEGIN TO DIMINISH TOWARD THE EARLY TO MID
MORNING HOURS...BUT CLOUDS WILL RETURN DURING THE EARLY AFTERNOON AS
A SURFACE WARM FRONT APPROACHES THE TRI STATE AREA. RAIN SHOWERS
AND THUNDERSTORMS WILL DEVELOP IN THE LATE MORNING TO EARLY
AFTERNOON HOURS...MAINLY EAST OF HIGHWAY 83. CAPE VALUES AROUND
1000 J/KG AND BULK SHEAR BETWEEN 35 AND 40 KTS WILL BRING SOME
SEVERE POTENTIAL WITH LARGE HAIL AND DAMAGING WINDS...ALTHOUGH THE
MAIN ATMOSPHERIC DYNAMICS ARE WELL EAST OF OUR FORECAST AREA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 241 PM MDT THU APR 23 2015
THE UPPER TROUGH AND SURFACE LOW MOVING ACROSS THE AREA ON FRIDAY
WILL CONTINUE TO LIFT ENE AS A CLOSED LOW FRIDAY NIGHT WITH WEAK
SHORT WAVE RIDGING ALOFT OVER THE CENTRAL HIGH PLAINS ON SATURDAY.
SATURDAY LOOKS MOSTLY DRY BETWEEN SYSTEMS WITH THE NEXT LOW
PRESSURE CENTER DIVING INTO THE SOUTHWEST U.S. SOUTH OF THE
4-CORNERS REGION DURING BY SUNDAY MORNING. THE LOW ALOFT MOVES
INTO THE WEST TEXAS PANHANDLE REGION BY MONDAY MORNING...MOVING
SLOWLY INTO POSITION OVER EAST TEXAS AND EAST OKLAHOMA BY TUESDAY
MORNING AS THE SURFACE LOW TRACKS FURTHER SOUTH ALONG THE GULF
COAST OF TEXAS.
WITH THE MAIN LOW PRESSURE AREA ACROSS THE SOUTH CENTRAL U.S. WELL
SOUTH OF THE FORECAST AREA...THE SATURDAY NIGHT THROUGH MONDAY
NIGHT TIME FRAME WILL REMAIN UNSETTLED ACROSS THE FORECAST AREA WITH
A CHANCE OF RAIN SHOWERS AND THUNDERSTORMS...BUT EXPECT THE BULK
OF THE PRECIPITATION TO STAY OVER THE SOUTHERN PLAINS. TUESDAY
THROUGH THURSDAY SHOULD BE DRY AS THE AMPLIFYING RIDGE OVER THE
WEST COAST MOVES OVER THE ROCKIES AND HIGH PLAINS REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1147 AM MDT THU APR 23 2015
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE IN THE VICINITY OF
KGLD THIS AFTERNOON AND TONIGHT...WHICH WILL BRING GUSTY WINDS.
ONCE STORMS PASS THE VICINITY OF KGLD...LOWER FLIGHT CATEGORIES
WILL BE PRESENT DUE TO CEILING HEIGHTS AND VISIBILITY REDUCTIONS.
THUNDERSTORMS WILL DEVELOP IN THE VICINITY OF KMCK THIS
AFTERNOON...AND RAIN SHOWERS WILL DEVELOP IN THE EVENING AND
OVERNIGHT HOURS. LOWER FLIGHT CATEGORIES WILL RESULT TONIGHT DUE
TO LOW CEILINGS AND REDUCED VISIBILITIES.
BOTH TERMINALS SHOULD SEE FLIGHT CONDITIONS IMPROVE IN THE MID
MORNING HOURS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...MK
LONG TERM...LOCKHART
AVIATION...MK
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
343 PM CDT THU APR 23 2015
...UPDATED SHORT TERM DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 342 PM CDT THU APR 23 2015
FORECAST ISSUES IN THE SHORT TERM CENTER AROUND THUNDERSTORM CHANCES
TONIGHT AND FRIDAY AND THE SEVERE WEATHER POTENTIAL ASSOCIATED WITH
THE STORMS.
THE ATMOSPHERE OVER THE HIGH PLAINS OF EASTERN COLORADO AND FAR WESTERN
KANSAS WAS BECOMING MODERATELY UNSTABLE WITH DAYTIME HEATING THIS
AFTERNOON. A SURFACE TROUGH OF LOW PRESSURE STRENGTHENING OVER EASTERN
COLORADO WAS ALSO PROVIDING SOME LOW LEVEL CONVERGENCE AND TRIGGERING
WIDELY SCATTERED THUNDERSTORMS. SPC MESOANALYSIS SHOWS 30- 40 KNOTS
OF SHEAR IN THE 0-6 KM LAYER BUT ABOVE THIS LAYER, STRONGER SHEAR
WAS IN PLACE IN THE PRESENCE OF A STRONG SUBTROPICAL JET. THE STORMS
OVER EASTERN COLORADO WILL BE IN A FAVORABLE ENVIRONMENT TO BECOME
ROTATING SUPERCELLS. GIVEN THE STRONG EVACUATION ALOFT, LARGE HAIL
WILL BE A GOOD POSSIBILITY. THE HRRR MODEL HAS BEEN VERY CONSISTENT
WITH THUNDERSTORMS MOVING INTO WESTERN KANSAS AROUND JOHNSON AND
SYRACUSE AND POINTS NORTH THIS EVENING AROUND 23Z-01Z AND HAVE
KEPT THE BEST CHANCES IN THAT AREA EARLY THIS EVENING. AS THE
NIGHT CONTINUES, AN AREA OF THUNDERSTORMS COULD CONTINUE TO DEVELOP
OVER WEST CENTRAL AND NORTHWEST KANSAS AS A WEAK MID LEVEL DISTURBANCE
ALONG WITH THE LEFT EXIT REGION OF AN UPPER LEVEL SPEED MAX MOVES
OVER THE AREA. THE MODELS ALSO SHOW INCREASING SOUTHERLY FLOW AT THE
850 MILLIBAR LEVEL WHICH COULD ALSO HELP SUSTAIN THUNDERSTORMS THROUGH
THE NIGHT. THE BEST CHANCE FOR STORMS SHOULD BE ALONG AND/OR NORTH
OF HIGHWAY 50 AND 156. THE THREAT FOR SEVERE WEATHER SHOULD DIMINISH
SOMEWHAT AFTER DARK BUT CAN`T RULE OUT THE POSSIBILITY OF A FEW
ELEVATED HAILERS. CHANCES FOR STORMS WILL DIMINISH LATER TONIGHT
AS THE MID/UPPER LEVEL SUPPORT MOVES EAST OF THE AREA.
ON FRIDAY, THE MAIN UPPER TROUGH MOVES OUT INTO THE CENTRAL AND
SOUTHERN PLAINS. THE MODELS DEVELOP A SURFACE LOW OVER WEST CENTRAL
KANSAS WITH A FRONTAL BOUNDARY EXTENDING EAST FROM THE LOW. BY FRIDAY
AFTERNOON THE LOW WILL BE PROGRESSING EAST WHILE A DRYLINE PUSHES
EAST ACROSS SOUTHWEST THROUGH SOUTH CENTRAL KANSAS. THE UPPER LEVEL
JET PROPAGATES EAST THROUGH THE DAY. THE 18Z MODELS ARE NOW LOOKING
LESS FAVORABLE FOR SEVERE POTENTIAL AS THE BETTER 0-6 KM SHEAR WILL
BE TO THE SOUTH AND EAST OF THE DODGE CITY CWFA DURING THE MID/LATE
AFTERNOON HOURS. WITH SOME GOOD INSTABILITY OVER THE NORTHERN AND
EASTERN SECTIONS OF THE CWA, THERE WILL STILL BE POTENTIAL FOR
SOME SEVERE STORMS AS WELL AS THE POTENTIAL FOR TORNADOES ALONG
AND NORTH OF THE FRONTAL BOUNDARY OVER CENTRAL KANSAS.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 315 PM CDT THU APR 23 2015
THE WEAK UPPER LEVEL LOW WILL CONTINUE TO MOVE EASTWARD ACROSS
THE KS/NE BORDER FRIDAY NIGHT. THIS WILL HELP PUSH A SURFACE LOW
AND ASSOCIATED COLD FRONT THROUGH THE REMAINDER OF THE CWA AND
INTO EASTERN KANSAS. A FEW LINGERING THUNDERSTORMS WILL BE
POSSIBLE ACROSS CENTRAL KANSAS AS WELL AS AROUND THE I-70 CORRIDOR
IN THE EVENING WITH PRECIPITATION CHANCES COMING TO AN END
SOMETIME AFTER MIDNIGHT. NORTHWESTERLY WINDS WILL BE FELT BEHIND
THIS SYSTEM AND CONTINUE THROUGH THE MOST OF SATURDAY. SKIES LOOK
TO BECOME MOSTLY CLEAR BY SUNRISE SATURDAY AND CONTINUE THROUGH
THE DAY SATURDAY AS DRIER AIR MOVES INTO THE AREA. WINDS THEN
SHIFT TO MORE OF AN EASTERLY DIRECTION SATURDAY EVENING THROUGH
SUNDAY AS AN AREA OF LOW PRESSURE DEVELOPS AND INTENSIFIES
SOUTHWEST OF THE AREA. THIS OCCURS IN RESPONSE TO AN UPPER LEVEL
OPEN WAVE DIGGING INTO THE DESERT SOUTHWEST SATURDAY, INTENSIFYING
INTO AN UPPER LEVEL LOW OVER THE FOUR CORNER`S REGION SUNDAY.
MODELS THEN SUGGEST THAT THIS LOW WILL MOVE EASTWARD ACROSS THE
SOUTHERN PLAINS MONDAY INTO TUESDAY. HOWEVER, WITH THIS SYSTEM
BEING MORE THAN 4 DAYS OUT TIMING AND POSITION WILL MOST LIKELY
CHANGE OVER THE NEXT COUPLE OF MODEL RUNS. IF FUTURE MODEL RUNS
PREDICT THIS FEATURE TO MOVE FARTHER NORTH, THE CWA COULD SEE SOME
BENEFICIAL RAIN SUNDAY NIGHT THROUGH TUESDAY. NEVERTHELESS, HIGH
CLOUDS LOOK INCREASE IN COVERAGE SUNDAY AS THIS FEATURE MOVES
CLOSER TO THE AREA WITH MOSTLY CLOUDY SKIES EXPECTED SUNDAY NIGHT
THROUGH AT LEAST MONDAY. WINDS SHIFT TO MORE OF A NORTHERLY
DIRECTION BEHIND THIS SYSTEM THROUGH TUESDAY. UPPER LEVEL RIDGING
IS THEN EXPECTED TO BUILD INTO THE WESTERN UNITED STATES BEHIND
THIS SYSTEM WITH HIGH PRESSURE BEING THE DOMINATING FACTOR AT THE
SURFACE. THIS WILL BRING DRIER CONDITIONS TO WESTERN KANSAS FOR
THE REMAINDER OF THE WEEK.
AS FOR TEMPERATURES, LOWS FRIDAY NIGHT THROUGH MONDAY NIGHT WILL
GENERALLY BE IN THE 40S WITH THE EXCEPTION OF SOUTH CENTRAL KANSAS
FRIDAY NIGHT WHERE LOWER 50S WILL BE POSSIBLE AND WEST CENTRAL
KANSAS MONDAY NIGHT WHERE UPPER 30S COULD BE POSSIBLE. HIGHS LOOK
TO BE IN THE 70S WITH A FEW AREAS ACROSS THE KS/OK BORDER REACHING
INTO THE LOWER 80S SATURDAY THEN DECREASE INTO THE 60S SUNDAY. THE
COLDEST DAY OVER THE EXTENDED PERIOD LOOKS TO BE ON MONDAY WITH
HIGHS POSSIBLY ONLY REACHING TO AROUND 60 DEGREES. HIGHS ARE
FORECASTED TO REACH INTO THE MID 60S TUESDAY WITH 70S POSSIBLE
WEDNESDAY. LOWS TUESDAY THROUGH THURSDAY MORNING LOOK TO DIP INTO
THE 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1235 PM CDT THU APR 23 2015
MVFR CIGS SHOULD CONTINUE THROUGH THE AFTERNOON AT THE GARDEN
CITY AND DODGE CITY TERMINALS. VFR CONDITIONS SHOULD PREVAIL AT
HAYS ALTHOUGH SOME MVFR CIGS COULD DEVELOP OFF AND ON THIS
AFTERNOON. WIDELY SCATTERED THUNDERSTORMS DEVELOPING OVER EASTERN
COLORADO LATER THIS AFTERNOON ARE EXPECTED TO MOVE INTO WESTERN
KANSAS EARLY THIS EVENING. THERE IS SOME UNCERTAINTY WHETHER THE STORMS
WILL IMPACT OPERATIONS AT GARDEN CITY AND DODGE CITY AND HAVE
INCLUDED VCTS AT THOSE TERMINALS. HAYS WILL HAVE A BETTER CHANCE
TO BE IMPACTED AND WILL CARRY A TEMPO GROUP THERE LATER TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 54 81 49 78 / 40 20 20 10
GCK 50 77 48 77 / 50 20 20 10
EHA 49 76 47 79 / 30 10 10 10
LBL 54 80 48 81 / 30 10 10 10
HYS 51 73 50 73 / 60 40 40 10
P28 56 82 52 80 / 30 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GERARD
LONG TERM...HOVORKA_42
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS GOODLAND KS
112 PM MDT THU APR 23 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 112 PM MDT THU APR 23 2015
LOW CLOUDS THAT WERE PRESENT ACROSS THE AREA DURING THE MORNING
HOURS CONTINUED TO LINGER FOR SOME LOCATIONS ACROSS THE TRI STATE
AREA IN THE EARLY AFTERNOON ON VISIBLE SATELLITE IMAGERY...HOWEVER
MOST LOCATIONS WERE UNDER PARTLY TO MOSTLY CLEAR SKIES. RAP 500 MB
ANALYSIS AND WATER VAPOR IMAGERY SHOWED A SHORTWAVE TROUGH ACROSS
THE CENTRAL HIGH PLAINS REGION...HOWEVER A LONGWAVE TROUGH ACROSS
THE GREAT BASIN REGION WAS MOVING EASTWARD INTO THE CENTRAL HIGH
PLAINS.
THE ADVANCING TROUGH WILL BRING SOME POCKETS OF HIGHER POTENTIAL
VORTICITY VALUES ACROSS THE TRI STATE AREA LATER THIS AFTERNOON AND
TONIGHT...WHICH WILL HELP DESTABILIZE THE ATMOSPHERE AND CAUSE
STORMS TO DEVELOP. A SURFACE STATIONARY BOUNDARY TO THE WEST ALONG
THE COLORADO FRONT RANGE WILL ALSO PROVIDE THE NEEDED PUSH AT THE
SURFACE TO GET STORMS GOING. MOST MODEL GUIDANCE HAS INITIATION
OCCURRING SOMETIME BETWEEN 21 AND 00Z IN EASTERN COLORADO WITH
STORMS GETTING GOING BY 00Z. PROFILE CAPE BETWEEN 1000 AND 1500
J/KG AND BULK SHEAR BETWEEN 30 AND 35 KTS MAY BE ENOUGH TO CAUSE
SOME STORMS TO PRODUCE LARGE HAIL...AND DRY MID LEVELS IN MODEL
SOUNDINGS WITH DCAPE BETWEEN 800 AND 1000 J/KG COULD RESULT IN
DAMAGING WINDS GUSTS. THE SHEAR VALUES DIMINISH OVERNIGHT...BUT
CAPE WILL STILL BE PRESENT OVERNIGHT AS STORMS MOVE EASTWARD.
THEREFORE...EXPECTING STORMS TO CONTINUE OVERNIGHT FOR SOME
LOCATIONS.
THE SURFACE STATIONARY FRONTAL BOUNDARY WILL REMAIN DRAPED ACROSS
THE TRI STATE AREA OVERNIGHT...WHICH WILL BRING SOUTHEAST WINDS AT
THE SURFACE AND INCREASED RELATIVE HUMIDITIES OVERNIGHT. AS A
RESULT...FOG WILL DEVELOP AND CLOUD COVER WILL REMAIN INCREASED
OVERNIGHT. EXPECTING LOW TEMPERATURES TO BE SLIGHTLY WARMER AS A
RESULT OF THE BLANKETING CLOUD COVER IN THE UPPER 40S.
FOG AND LOWER CLOUDS WILL BEGIN TO DIMINISH TOWARD THE EARLY TO MID
MORNING HOURS...BUT CLOUDS WILL RETURN DURING THE EARLY AFTERNOON AS
A SURFACE WARM FRONT APPROACHES THE TRI STATE AREA. RAIN SHOWERS
AND THUNDERSTORMS WILL DEVELOP IN THE LATE MORNING TO EARLY
AFTERNOON HOURS...MAINLY EAST OF HIGHWAY 83. CAPE VALUES AROUND
1000 J/KG AND BULK SHEAR BETWEEN 35 AND 40 KTS WILL BRING SOME
SEVERE POTENTIAL WITH LARGE HAIL AND DAMAGING WINDS...ALTHOUGH THE
MAIN ATMOSPHERIC DYNAMICS ARE WELL EAST OF OUR FORECAST AREA.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 303 AM MDT THU APR 23 2015
ANOTHER SYSTEM WILL BEGIN TO MOVE INTO THE AREA EARLY SUNDAY. THIS
WILL BRING THE POSSIBILITY OF PRECIPITATION TO THE FORECAST AREA
THROUGH MONDAY NIGHT/TUESDAY. THE UPPER LEVEL LOW WILL TRACK TO THE
SOUTH TOWARDS TEXAS AND OKLAHOMA ON SUNDAY AND MONDAY. HIGH PRESSURE
WILL BUILD INTO THE HIGH PLAINS ON WEDNESDAY BRINGING DRIER AND
WARMER CONDITIONS.
MODELS ARE IN DISAGREEMENT ON HOW TO HANDLE THE TROUGH AS IT MOVES
INTO THE CONUS FROM CANADA MONDAY NIGHT. GFS SHOWS A LOW DEVELOPING
OVER CANADA AND MOVING SOUTH TOWARDS THE SOUTHERN LOW. THIS AFFECTS
THE TIMING OF THE RIDGE BUILDING INTO THE AREA BEHIND THE SYSTEM.
WILL HAVE TO SEE HOW FUTURE MODEL RUNS HANDLE THIS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1147 AM MDT THU APR 23 2015
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE IN THE VICINITY OF
KGLD THIS AFTERNOON AND TONIGHT...WHICH WILL BRING GUSTY WINDS.
ONCE STORMS PASS THE VICINITY OF KGLD...LOWER FLIGHT CATEGORIES
WILL BE PRESENT DUE TO CEILING HEIGHTS AND VISIBILITY REDUCTIONS.
THUNDERSTORMS WILL DEVELOP IN THE VICINITY OF KMCK THIS
AFTERNOON...AND RAIN SHOWERS WILL DEVELOP IN THE EVENING AND
OVERNIGHT HOURS. LOWER FLIGHT CATEGORIES WILL RESULT TONIGHT DUE
TO LOW CEILINGS AND REDUCED VISIBILITIES.
BOTH TERMINALS SHOULD SEE FLIGHT CONDITIONS IMPROVE IN THE MID
MORNING HOURS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...MK
LONG TERM...JBH
AVIATION...MK
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
321 PM CDT THU APR 23 2015
.SYNOPSIS...
ISSUED AT 320 PM CDT THU APR 23 2015
SPLIT UPPER LEVEL PATTERN OVER THE WESTERN HALF OF THE CONUS...BROAD
CYCLONIC FLOW TO THE EAST. A SHORTWAVE RIDGE WAS TRANSLATING EAST
ACROSS THE CENTRAL PLAINS...IN ADVANCE OF A STRONG PV MAX SLOWLY
MOVING NORTHEASTWARD ACROSS THE DESERT SOUTHWEST. THE ASSOCIATED
HEIGHT FALLS WITH THIS PATTERN WERE SUPPORTING THE GRADUAL DEEPENING
OF A LEE SIDE SFC TROUGH FROM NORTHEAST COLORADO THROUGH THE WESTERN
NEBRASKA PANHANDLE. EAST OF THIS TROUGH WINDS WERE BREEZY OUT OF THE
SOUTH...TRANSPORTING LOW LEVEL MOISTURE INTO THE CWA.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 320 PM CDT THU APR 23 2015
CUMULUS CLOUDS AND A FEW SHOWERS AND THUNDERSTORMS HAVE ALREADY
DEVELOPED JUST WEST OF THE CWA EARLY THIS AFTERNOON. HI-RES MODELS
HAVE CONSISTENTLY SHOWN THE THUNDERSTORM ACTIVITY INCREASING IN
COVERAGE AND MOVING EAST LATER THIS AFTERNOON AS A WEAK UPPER LEVEL
SHORTWAVE EJECTS OUT OF THE CENTRAL ROCKIES. THE BEST CHANCES
THROUGH THE EVENING WILL GENERALLY BE CONFINED TO THE PANHANDLE AND
SOUTHWEST NEBRASKA. AS FAR AS STORM INTENSITY...MLCAPE IN THE
VICINITY OF THE SFC TROUGH WILL NEAR 1000 J/KG BY LATER AFTERNOON
AND EARLY EVENING. STEEP MID LEVEL LAPSE RATES OF 7-8 C/KM ARE ALSO
IN PLACE OVER THE HIGH PLAINS. A STORM OR TWO REACHING STRONG TO
SEVERE LIMITS WITH HAIL AND GUSTY WINDS CANNOT BE RULED OUT...MAINLY
WEST OF HWY 61. THE ABILITY FOR STORMS TO SUSTAIN THEMSELVES AND
REMAIN ORGANIZED IS IN QUESTION DUE RATHER WEAK MID LEVEL FLOW AND
DEEP LAYER SHEAR ONLY AROUND 25 TO 30 KTS. THE MORE FAVORABLE
ENVIRONMENT WILL REMAIN TO THE SOUTH WHERE FASTER FLOW ALOFT AND
BETTER SHEAR PROFILES RESIDE.
THUNDERSTORM CHANCES MOVE EAST OVERNIGHT BUT COVERAGE SHOULD REMAIN
SCATTERED. UPPER LEVEL LOW CURRENTLY OVER THE DESERT SOUTHWEST WILL
EJECT EASTWARD TOWARD THE CENTRAL PLAINS. THIS WILL KEEP SOUTHERLY
FLOW IN PLACE OVERNIGHT...AND EVENTUALLY THE REDEVELOPMENT OF
STRATUS CLOUDS OVER MUCH OF THE AREA. PATCHY FOG IS POSSIBLE OVER
CENTRAL NEB...BUT BUFKIT DATA CONTINUES TO SUPPORT THICK LOW STRATUS
IN OUR ZONES. THIS IS ALSO SUPPORTED BY VISBY FIELDS IN RECENT RUNS
OF THE HRRR AND NAM. CONFIDENCE NOT HIGH ENOUGH TO INCLUDE ANY FOG
IN THE GRIDS AT THIS POINT...BUT THE EVENING SHIFT WILL NEED TO
REEVALUATE.
MODELS PAINT QPF ACROSS MUCH OF THE CWA BY FRIDAY AFTERNOON...BUT
REMAIN ALL OVER THE PLACE IN REGARDS TO THEIR PLACEMENT. EXPECTING
SCATTERED AND DISORGANIZED SHOWERS AND THUNDERSTORMS DUE TO LACK OF
A FOCUS FOR DEVELOPMENT. NOT EXPECTING MUCH IN THE WAY OF SEVERE
WEATHER AS THE MUCH BETTER ENVIRONMENT WILL BE OFF TO OUR SOUTH AND
EAST.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 320 PM CDT THU APR 23 2015
LONG WAVE TROUGH WILL BE MOVING INLAND FROM THE WEST COAST
FRIDAY NIGHT...WITH A LEAD SHORTWAVE MOVING ACROSS THE CENTRAL PLAINS
AHEAD OF THE TROUGH FRIDAY NIGHT. OPERATIONAL MODELS FCST THE
CENTRAL PLAINS TROUGH TO BECOME CLOSED NEAR OR JUST WEST OF THE MID
MISSOURI VALLEY. THIS WILL BE A RATHER DISORGANIZED EVENT...AND
WITH ONLY WEAK MOISTURE TRANSPORT...LIFT WILL ALSO BE SOMEWHAT
LIMITED AND UNFOCUSED. THIS CONTINUES TO SUGGEST A SHOWERY AND
UNORGANIZED PRECIPITATION EVENT. WILL LIMIT HIGHEST POPS TO 40 TO
50 PERCENT EVENING AND 20 TO 30 PERCENT AFTER MIDNIGHT. BEST
INSTABILITY ACROSS SERN ZONES...WITH HIGHER TSTM CHANCES WITH ONLY
ISOLATED EXPECTED ACROSS THE NORTH/NORTHWEST.
THE MAIN UPPER TROUGH WILL DIG SOUTHEAST ACROSS THE GREAT BASIN ON
SATURDAY AS A TRANSITORY RIDGE MOVES INTO THE CNTRL PLAINS. THIS
WILL LESSEN POPS TO ONLY A SLIGHT CHANCE NORTH AND WEST WITH PARTLY
SUNNY SKIES AND HIGH TEMPS NEAR 60 NORTHEAST TO NEAR 70 FAR
SOUTHWEST. THE GFS ENSEMBLE...GFS...AND ECMWF ALL AGREE THAT THE
UPPER TROUGH WILL DEEPEN INTO THE FOUR CORNERS REGION SATURDAY
NIGHT WITH AN AMPLIFIED SRLY FLOW ALOFT ACROSS THE CNTRL HIGH
PLAINS. CHCS FOR SHOWERS AND THUNDERSTORMS WILL BE CONFINED TO THE
HIGHS PLAINS WITH CHC POPS WEST OF HWY 83...AND NO WX ACROSS THE
EAST. ANY SHOWERS THAT DEVELOP WILL MOVE NORTH WILL LITTLE OR NOW
EASTWARD PROGRESSION. MEDIUM RANGE MODELS THEN INDICATED CLOSED
LOW WILL TRACK EAST ACROSS NEW MEXICO...THE TEXAS PANHANDLE...AND
THEN ACROSS NORTHERN TEXAS AND SOUTHERN OKLAHOMA SUNDAY THROUGH
MONDAY NIGHT. THERE REMAINS ENOUGH MODEL AGREEMENT AND CONFIDENCE
TO KEEP POPS INTO THE LIKELY CATEGORY ACROSS THE EASTERN PANHANDLE
SUNDAY WITH CHC POPS EAST TO VALENTINE THROUGH BROKEN BOW. AS NRN
STREAM TROUGH APPROACHES SUNDAY NIGHT AND MONDAY...POPS LESSEN AND
REMAIN ONLY ACROSS THE WEST. DRY MONDAY NIGHT AND BEYOND. UPPER
RIDGE OVER THE GREAT BASIN WILL SLOWLY BUILD EAST INTO THE CENTRAL
CONUS THROUGH THURSDAY. THE COOLEST DAY LOOK TO BE SUNDAY AS
EASTERLY UPSLOPE WINDS AND CLOUDINESS/SHOWERS LIMITS HIGHS TO
LOWER MID 50S WEST TO NEAR 60 EAST. HIGHS THEN WARM INTO THE 60S
MONDAY/TUESDAY...LOW 70S WEDNESDAY...THEN MID/UPPER 70S THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1242 PM CDT THU APR 23 2015
MORNING STRATUS DECK FROM SOUTHWEST INTO CENTRAL NEBRASKA IS
BEGINNING TO LIFT AND ERODE EARLY THIS AFTERNOON. EXPECTING VFR
CIGS AT ALL TERMINALS IN WESTERN AND NORTH CENTRAL NEBRASKA BY MID
AFTERNOON. NEXT AVIATION CONCERN IS THE CHANCE FOR TSRA LATER THIS
AFTERNOON AND EVENING. THE ACTIVITY WILL LIKELY BE SCATTERED IN
COVERAGE..AND DOES NOT WARRANT MENTION IN THE TAF AT THIS TIME.
TRENDS WILL MONITORED THROUGH THE AFTERNOON AND TSRA AMENDMENTS
MADE TO THE TAF IF NECESSARY.
STRATUS CLOUDS AND LOW CIGS WILL REDEVELOP OVERNIGHT. CONFIDENCE
IS HIGH IN THE OCCURRENCE OF MVFR OR LOWER CIGS ACROSS SOUTHWEST
NEBRASKA...INCLUDING KLBF. FURTHER NORTH...NEAR KVTN...MODEL
GUIDANCE HAS BEEN HIT OR MISS WITH THE POTENTIAL LOW CIGS FOR
TONIGHT INTO FRIDAY MORNING. INCLUDED BKN030 GROUP TO HIGHLIGHT
THE POTENTIAL FOR LOWER CIGS AT KVTN...HOWEVER FORECASTER
CONFIDENCE IS LOW AT THIS TIME.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MARTIN
SHORT TERM...MARTIN
LONG TERM...ROBERG
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1255 PM CDT THU APR 23 2015
.UPDATE...
ISSUED AT 637 AM CDT THU APR 23 2015
THE 06Z NAM CAME IN STILL TRYING TO INITIATE TSTMS OVER SW NEB
THIS MORNING. THIS AS INCREASING LOW-LVL MOISTURE CREATES
ELEVATED INSTABILITY. THE 08Z HRRR DOESN`T HAVE IT AND THAT
BOLSTERS OUR CONFIDENCE IN KEEPING THE FCST DRY.
AFTER REVIEWING MORE DATA FOR THE 12Z TAFS...INSERTED A MENTION OF
FOG IN THE FCST LATE TONIGHT INTO FRI AM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CDT THU APR 23 2015
ALOFT: SPLIT FLOW CONTS BUT THE FCST AREA WILL BE MORE AFFECTED
BY THE SRN STREAM OVER THE NEXT 24 HRS. TWO UPR LOWS WERE OVER SRN
CA AND W OF THE BAJA PENINSULA. THESE LOWS WILL FILL AND
CONSOLIDATE AND PROGRESS THRU THE SW USA...WITH A +TILT TROF
EXTENDING FROM CO-AZ BY 12Z/FRI. IN THE MEANTIME...THE W FLOW
ALOFT OVER THE CNTRL PLAINS WILL BECOME ANTICYCLONIC AND
EVENTUALLY TURN SW.
SURFACE: HIGH PRES HAS DRIFTED INTO THE MS VALLEY AND WILL REMAIN
E OF THE REGION THRU TONIGHT. THE PRIMARY POLAR FRONT WILL REMAIN
OVER THE SRN PLAINS BUT BEGIN LIFTING N AS A WARM FRONT TONIGHT
...IN RESPONSE TO FALLING PRES WITHIN THE STRENGTHENING LEE TROF
AND EVENTUAL CYCLOGENESIS.
TODAY: GRADUALLY BECOMING CLOUDY. SATELLITE SHOWS STRATUS FORMING
AND EXPANDING ON THE COOL SIDE OF THE FRONT OVER NRN TX/OK/KS...
WITHIN A PLUME OF MODESTLY RICH LOW-LVL MOISTURE. THIS PLUME AND
THE STRATUS WILL OVERTAKE THE FCST AREA FROM SW-NE AND KEEP TEMPS
FROM REACHING THEIR MAX POTENTIAL.
QPF: ALL MODEL GRID-SCALE AND/OR CONVECTIVE PRECIP SCHEMES ARE
OUTPUTTING LIGHT QPF TODAY. JUST DON`T SEE IT HAPPENING GIVEN THE
LACK OF FORCING AND OVERALL RIDGING/SUBSIDENCE ALOFT. FCST
SOUNDINGS DON`T HAVE THE LOOK OF SPRINKLES EITHER. SO THEY WERE
WITHDRAWN FROM THE FCST. BELIEVE THE 00Z WRF-NMM DEPICTION IS MOST
LIKELY TO VERIFY. TODAY IS QUIET AND DRY THEN SCT TSTMS WILL
DEVELOP TO THE W LATE AFTERNOON WITHIN THE LEE TROF AND THEY
SHOULD PROPAGATE E AND BE MAINTAINED AS THEY ACCESS THE LLJ/WAA
AND GREATER LOW-LVL MOISTURE. NEW TSTMS MAY ALSO DEVELOP WITHIN
THE LLJ. BEST CHANCE FOR RAIN PER SREF QPF PROBABILITIES WILL BE
OVER N-CNTRL KS UP INTO THE SUPERIOR-HEBRON AREA.
INSTABILITY FROM THE 03Z SREF WILL BE ENOUGH TO SUPPORT THUNDER
FOR THE ENTIRE FCST AREA...BUT MUCAPE WILL BE UNDER 750 J/KG OVER
S- CNTRL NEB AND NOT EVEN REACH 1000 J/KG OVER N-CNTRL KS.
EFFECTIVE SHEAR WILL BE AROUND 25 KTS. SO RISK FOR EVEN A STRONG
TSTM APPEARS LIMITED.
TONIGHT: CLOUDY. SCT SHWRS/TSTMS. NOT EVERY LOCATION WILL SEE
THEM. THERE IS PLENTY OF UNCERTAINTY ON COVERAGE OF SHWRS/TSTMS.
CURRENTLY HAVE HIGHEST PROBABILITIES SE OF THE TRI-CITIES.
NUDGED LOW TEMPS ROUGHLY 3F ABOVE THE PREVIOUS FCST DUE TO
EXPECTED CLOUD COVER.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 359 AM CDT THU APR 23 2015
THE MAIN FOCUS IS ON TSTMS FRIDAY AND FRIDAY NIGHT.
ON FRIDAY...THE PATTERN ALOFT WILL FEATURE SOUTHWEST FLOW ACROSS
THE CENTRAL PLAINS WITH A LEAD SHORTWAVE TROUGH LIFTING ACROSS OUR
REGION AHEAD OF A DEEPER SHORTWAVE NEAR THE FOUR CORNERS REGION.
PCPN IS EXPECTED TO BE ONGOING/LINGERING INTO THE DAY ON FRIDAY
WITH THE PASSING LEAD WAVE...WITH REDEVELOPMENT OF RAIN SHOWERS
AND THUNDERSTORMS EXPECTED FRIDAY AFTERNOON/EVENING AND CONTINUING
THRU FRIDAY NIGHT AS THE SOUTHERN DEEPER TROUGH LIFTS OUT ACROSS
THE CENTRAL PLAINS.
CANNOT RULE OUT THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS
PRIMARILY ACROSS KANSAS INTO THE SOUTHERN PORTION OF NEBRASKA
FRIDAY AFTN/EVE. THE FIRST PART OF THE DAY ON FRIDAY WILL LIKELY
SEE REMNANT/DEPARTING CONVECTION AND A FAIR AMOUNT OF CLOUD COVER.
BREAKS IN THE CLOUDS ARE EXPECTED ACROSS OUR SOUTHERN AND WESTERN
ZONES HEADING INTO THE AFTERNOON AND A MOISTURE AXIS WITH SFC DPS
IN THE MID 50S ARE FORECAST TO ALIGN ACROSS THE EASTERN HALF OF
KANSAS INTO SOUTHEAST NEB WITH INSTABILITY PROGGED TO INCREASE TO
AROUND 1500 J/KG OR SO BY EVENING ACROSS OUR SOUTHERN ZONES.
STORMS ARE EXPECTED TO INITIATE ALONG/AHEAD OF THE SFC TROUGH AND
DRY LINE AND WARM FRONTAL BOUNDARY. SHEAR PROGS AVERAGE 30KTS AND
COMBINED WITH THE INSTABILITY...THE PRIMARY HAZARDS FROM THE
STORMS WILL BE LARGE HAIL/DAMAGING WINDS THRU THE EVENING
HOURS...WITH CHCS FOR SEVERE STORMS DECREASING OVERNIGHT.
ON SATURDAY...A FEW SHOWERS MAY LINGER IN THE MORNING UNTIL THE
UPPER LOW PASSES FARTHER TO THE EAST...THEN THE FORECAST DRIES OUT
FOR THE REMAINDER OF THE DAY. HEIGHTS RISE BEHIND THE DEPARTING
SYSTEM IN SHORTWAVE RIDGING IN BETWEEN ANOTHER TROUGH MOVING INTO
THE CENTRAL ROCKIES.
THERE REMAINS A FAIR AMOUNT OF UNCERTAINTY IN HANDLING THE UPPER
LOW IN THE ROCKIES OVER THE WEEKEND WITH THE GFS LIFTING OUT THE
SYSTEM FARTHER NORTH THAN THE ECMWF AND GFS ENSEMBLE. HAVE
MAINTAINED SOME BUFFER LOW POPS FOR OUR WESTERN COUNTIES SATURDAY
NIGHT BUT IN GENERAL HAVE LOWERED POPS FROM SUNDAY THROUGH TUESDAY
WITH MODELS BEGINNING TO FAVOR A MORE SOUTHERN SOLUTION.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1245 PM CDT THU APR 23 2015
SIGNIFICANT WEATHER CHANGES WILL IMPACT AVIATION SERVICES FOR THE
AREA...ESPECIALLY TONIGHT AND SATURDAY. ALREADY SEEING SOME
INCREASE IN LOW/MID LEVEL CLOUDS ACROSS THE AREA...BUT MODELS ARE
IN GOOD AGREEMENT DEEPER MOISTURE TONIGHT WILL RESULT IN AT LEAST
MVFR CEILINGS...IF NOT IFR CEILINGS FOR THE FORECAST AREA TONIGHT
AND MOST OF THE DAY SATURDAY. ALL THE WHILE...A DEVELOPING UPPER
WAVE WILL MOVE ACROSS THE AREA AND CHURN UP SOME SHOWERS...AND
ISOLATED THUNDERSTORMS LATE TONIGHT WHICH WILL LIKELY LINGER INTO
THE DAY FRIDAY. SHOULD RESULT IN A PERIOD OF AT LEAST STEADY
PRECIPITATION DURING THE LAST 6 TO 9 HOURS OF THE FORECAST PERIOD.
VISIBILITIES COULD BE UP AND DOWN DURING THAT TIME...AND CURRENT
VSBY FORECAST OF 2-3 MILES IS LIKELY TOO HIGH BUT THERE COULD BE
SIGNIFICANT VISIBILITY VARIATIONS AT TIMES.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...HALBLAUB
LONG TERM...FAY
AVIATION...NOAA/NWS/MORITZ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
505 PM CDT THU APR 23 2015
.UPDATE...
ISSUED AT 503 PM CDT THU APR 23 2015
GETTING REPORTS OF SNOW FROM STANLEY AND PARSHALL AREAS. LOOKS
LIKE COOLING TO THE WET BULB IS CREATING ENOUGH COOLING FOR SNOW
LATE THIS AFTERNOON.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 303 PM CDT THU APR 23 2015
SHOWERS THIS AFTERNOON THROUGH TONIGHT HIGHLIGHT THE SHORT TERM
FORECAST.
OUTSIDE OF THE HIGHWAY 200 CORRIDOR...THE MAJORITY OF
PRECIPITATION IS NOT REACHING THE GROUND DUE TO DRY AIR IN THE
SUB-800 MB LAYER. THE 16-18 UTC HRRR ITERATIONS HAVE THE BEST
HANDLING OF THE ONGOING PRECIPITATION...ESPECIALLY THAT WHICH IS
REACHING THE GROUND...AND WILL WEIGH HEAVILY ON THEIR SOLUTIONS
THROUGH AFTERNOON AND EVENING. THEREAFTER...THE 12 AND INCOMING 18
UTC GLOBAL AND HIGH RESOLUTION SUITES ARE IN AGREEMENT ON ELEVATED
SHOWERS DEVELOPING TONIGHT ACROSS THE JAMES AND INTO THE RED RIVER
VALLEYS BY 05 UTC WITH A MODEST LOW LEVEL JET AHEAD OF THE
SURFACE LOW ACROSS WESTERN SOUTH DAKOTA. GIVEN MARGINALLY POSITIVE
SHOWALTER VALUES...WILL NOT PUT IN THUNDER AT THIS TIME. FRIDAY
APPEARS TO BE DRY ACROSS WESTERN AND CENTRAL NORTH DAKOTA BETWEEN
THE STRONGER LOW ACROSS THE CENTRAL PLAINS AND THE PACIFIC
NORTHWEST TROUGH.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 303 PM CDT THU APR 23 2015
A SPLIT FLOW THROUGH THE WEEKEND WITH PERIODS OF INTERACTION
BETWEEN THE SOUTHERN STREAM AND NORTHERN STREAM. THIS WILL
ULTIMATELY SET UP AN INCREASINGLY WET/UNSETTLED WEATHER PATTERN
THROUGH EARLY NEXT WEEK. TWO MAIN SHORTWAVES TO PUSH ACROSS WESTERN
AND CENTRAL NORTH DAKOTA FRIDAY NIGHT THROUGH MONDAY. THE LATEST
ECMWF IS ADVERTISING A MORE CONTINUOUS RAIN OVER THE WEEKEND INTO
MONDAY...WHILE THE GFS/CANADIAN GEM HAS A MORE DISTINCT START/END
TIME WITH EACH WAVE. UTILIZED A BLEND OF THE ABOVE MODELS ABOVE.
EXPECT A BRIEF DRYING AND WARMING TREND BY MIDWEEK...THEN A
PROGRESSIVE AND POSSIBLY UNSETTLED WEATHER PATTERN SETTING UP LATE
IN THE EXTENDED.
FOR FRIDAY NIGHT THROUGH SATURDAY...A TRANSITORY 700MB-500MB RIDGE
DEVELOPS OUT AHEAD OF AN APPROACHING SHORTWAVE TROUGH SLIDING INTO
THE NORTHERN ROCKIES. THIS SHOULD KEEP CONDITIONS DRY FOR MOST AREAS
FRIDAY NIGHT BEFORE EAST TO SOUTHEAST WINDS ADVECT AN AREA OF
MOISTURE INTO THE WEST. THIS MOISTURE WILL CONVERGE INTO AN
APPROACHING SURFACE COLD FRONT IN EASTERN MONTANA. THUS POPS BECOME
LIKELY THEN CATEGORICAL SATURDAY IN THE WEST...WITH DRIER CONDITIONS
IN THE EAST AS MID LEVEL RIDGING REMAINS INTACT UNTIL 00Z SUNDAY.
SATURDAY NIGHT THROUGH MONDAY NIGHT...AS MENTIONED ABOVE THERE ARE
DIFFERENCES IN THE ECMWF AND GFS/GEM...ESPECIALLY SATURDAY NIGHT
THROUGH SUNDAY. PER GFS/GEM...THE SURFACE LOW/COLD FRONT AND SHORTWAVE
MOVE INTO SOUTHERN CANADA WITH SHOWERS DIMINISHING SATURDAY NIGHT
INTO SUNDAY. THE TRAILING COLD FRONT STALLS UNDER A SOUTHWEST FLOW
ALOFT...WITH LOW LEVEL SOUTH TO SOUTHEAST WINDS FEEDING MOISTURE
INTO NORTH DAKOTA. THE GFS/GEM MODELS TREND TOWARD A CESSATION TO
THE PRECIPITATION UNTIL SUNDAY NIGHT WHEN THE THE FRONT BECOMES
RE-ENERGIZED AS THE NEXT SHORTWAVE TROUGH APPROACHES. WITH THE
SURFACE COLD FRONT AND SOUTHERN STREAM MOISTURE ALREADY IN
PLACE...THIS SETS THE STAGE FOR A MORE WIDESPREAD PRECIPITATION
EVENT SUNDAY NIGHT THROUGH MONDAY. AS MENTIONED ABOVE THE LATEST
ECMWF REALLY DOES NOT STOP THE PRECIPITATION WITH THE INITIAL
SHORTWAVE...RATHER KEEPS THE SURGE MAINLY CONTINUOUS IN THE WEST AND
SLOWLY SPREADS IT EAST AND NORTH THROUGH MONDAY. TOTAL PRECIPITATION
AMOUNTS COULD RANGE BETWEEN A HALF INCH TO ONE INCH IN THE WEST TO
AROUND A QUARTER OF AN INCH IN CENTRAL NORTH DAKOTA THROUGH MONDAY NIGHT.
MONDAY NIGHT THROUGH THURSDAY...GOOD AGREEMENT THAT PRECIPITATION
WILL BE EAST OF THE JAMES RIVER VALLEY BY 12Z TUESDAY FOLLOWED BY
UPPER RIDGING TUESDAY AND WEDNESDAY. WARM AIR ADVECTION RAMPS UP
LATE TUESDAY INTO WEDNESDAY...AHEAD OF AN ADVANCING COLD FRONT WHICH
IS FORECAST TO CROSS SOUTHERN CANADA WEDNESDAY AFTERNOON/EVENING. THE GFS
SHOWS SOME LIGHT PRECIPITATION DEVELOPING IN THE NORTH BEHIND THE
FRONT WEDNESDAY AFTERNOON. THE ECMWF IS ABOUT 6HRS SLOWER WITH THE
COLD FRONT...NOT ARRIVING INTO THE NORTHWEST UNTIL AROUND 00Z
THURSDAY. THURSDAY LOOKS DRY...ALTHOUGH THIS MAY BE BRIEF AS
THE NEXT SYSTEM IS ALREADY APPROACHING THURSDAY NIGHT INTO FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT |247 PM CDT THU APR 23 2015
SCATTERED RAIN SHOWERS ACROSS WESTERN AND CENTRAL NORTH DAKOTA
THIS AFTERNOON WILL CONTINUE TO MOVE EAST AND FADE WITH
SUNSET...BEFORE ADDITIONAL SHOWERS FORM TONIGHT NEAR KJMS AFTER 05
UTC. MVFR CONDITIONS IN RAIN POSSIBLE. OTHERWISE...VFR CONDITIONS
FOR THE 18 UTC CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...KS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
322 PM CDT THU APR 23 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 321 PM CDT THU APR 23 2015
PRECIP CHANCES AND TYPE TONIGHT AND TOMORROW WILL BE THE MAIN
FORECAST ISSUE FOR THE SHORT TERM.
WEST TO SOUTHWEST FLOW CONTINUES OVER THE REGION WITH VARIOUS WEAK
SHORTWAVES MOVING THROUGH THE FLOW. ONE WEAK LEAD SHORTWAVE HAS
ALREADY BEEN HEADING TOWARDS WESTERN ND...WITH SOME DECENT RADAR
RETURNS OVER THAT PART OF THE STATE. SOME LIGHT RAIN HAS BEEN
REACHING THE GROUND...ALTHOUGH NOT AS MUCH AS RADAR WOULD
INDICATE. DEW POINTS OVER THE CWA HAVE BEEN IN THE SINGLE DIGITS
TO TEENS. THE RAP AND HRRR HAVE THE PRECIP DISSIPATING AS IT MOVES
EAST...WHICH SEEMS REASONABLE GIVEN THE VERY DRY AIR. THINK THE
BETTER SHOT FOR PRECIPITATION WILL BE LATER TONIGHT AS A MORE
SOUTHERN SHORTWAVE MOVES INTO WY AND SFC LOW PRESSURE DEVELOPS
OVER WESTERN SD. THERE WILL BE SOME MID LEVEL WARM AIR
ADVECTION/FRONTOGENESIS OVER MAINLY THE SOUTHERN COUNTIES TONIGHT.
SOME OF THE MODELS HAVE SEVERAL TENTHS OF QPF TONIGHT...BUT GIVEN
HOW LONG IT WILL TAKE TO SATURATE WILL LEAN TOWARDS THE LOWER END
FOR PRECIP AMOUNTS. MODEL SOUNDINGS SHOW MOSTLY ABOVE ZERO AS THE
COLUMN SATURATES...BUT SOME SNOW MIXING IN ON THE NORTHERN EDGE OF
THE PRECIP IS NOT OUT OF THE QUESTION.
TOMORROW...THE SHORTWAVE TROUGH MOVES OUT INTO THE PLAINS...AND
THERE SHOULD BE A DECENT AMOUNT OF PRECIP OVER THE SOUTHERN
COUNTIES SPREADING NORTH AND EAST AS THE BEST MID LEVEL BAROCLINIC
ZONE LIFTS ACROSS THE AREA. CONTINUED TO KEEP LIKELY POPS FOR A
RAIN/SNOW MIX OVER THE SOUTHEASTERN COUNTIES FOR FRIDAY
MORNING...LINGERING INTO THE AFTERNOON. THE CLOUDS AND PRECIP
SHOULD KEEP TEMPS IN THE LOWER 40S IN THE EAST...BUT THINK THERE
WILL BE ENOUGH PEAKS OF SUN TO GET ABOVE 50 IN THE WESTERN
COUNTIES WHERE IT WILL BE DRIER. PRECIP WILL BEGIN TO TAPER OFF
FRIDAY NIGHT BUT KEPT SOME LOWER POPS THROUGH SATURDAY MORNING IN
OUR SOUTHEAST TO COORDINATE WITH NEIGHBORS. CLOUDS AND INCREASING
EASTERLY WINDS WILL KEEP TEMPS IN THE 30S FRIDAY NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 321 PM CDT THU APR 23 2015
SATURDAY AND SUNDAY...UPPER RIDGING WILL BUILD IN BRIEFLY...BUT
GIVE WAY AS THE NEXT SPLIT TROUGH BEGINS TO MOVE OUT FROM THE
WESTERN CONUS BY LATE SUNDAY. SFC HIGH PRESSURE OVER ONTARIO
SATURDAY WILL BRING EAST TO SOUTHEASTERLY WINDS WITH DRIER AIR INTO
THE CWA AND HIGHS SHOULD REACH THE 50S WITH AT LEAST SOME BREAKS
IN THE CLOUDS. TEMPS WILL BE EVEN WARMER FOR SUNDAY AS THE SFC
HIGH MOVES OFF TO THE EAST AND A TROUGH DEVELOPING OVER THE
WESTERN PLAINS STARTS SOME WARMER AIR MOVING BACK TO THE NORTH.
THE ECMWF TRIES TO BRING SOME PRECIP INTO OUR WESTERN COUNTIES FOR
SUNDAY AS THE NEXT UPPER SYSTEM APPROACHES...BUT THE OTHER MODELS
ARE A BIT SLOWER. INCLUDED SOME LOW POPS IN THE DEVILS LAKE BASIN
BUT THINK THE MAIN PRECIP WILL HOLD OFF UNTIL AFTER 00Z MONDAY.
SUNDAY NIGHT THROUGH THURSDAY...LONG WAVE UPPER LEVEL LOW PRESSURE
THAT WAS NORTH OF THE GREAT LAKES WILL MOVE OFF THE NEW ENGLAND
STATES EARLY IN THE PERIOD. BUT LONG WAVE TROUGH BECOMES RE-
ESTABLISHED OVER THE NORTHEAST STATES BY THE END OF THE PERIOD.
LONG WAVE UPPER RIDGE BUILDS OVER THE US AND CANADIAN ROCKIES THIS
PERIOD. ECMWF AND GFS WERE TRENDING FASTER THEN SLOWER OVER THE
LAST COUPLE MODEL RUNS. THE GFS IS FASTER THAN THE ECMWF. SO WILL
PREFER THE SLOWER ECMWF.
KEPT POPS FROM PREVIOUS RUN FOR MON NIGHT THROUGH TUE NIGHT.
APPROACHING UPPER LEVEL TROUGH WILL PRODUCE PRECIP FOR MON AND TUE
AND ANOTHER SHORT WAVE TROUGH IS EXPECTED WED NIGHT THROUGH THU
NIGHT.
HIGH TEMPS WERE INCREASED TWO TO FIVE DEGREES FOR MON TUE AND WED.
HIGH TEMPS DECREASED TWO TO FIVE DEGREES FOR THU FROM THIS MORNINGS
FORECAST PACKAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1256 PM CDT THU APR 23 2015
A CLEAR SKY WAS ACROSS MUCH OF THE FORECAST AREA. SOME CIRRUS CLOUDS
WERE MOVING INTO THE WESTERN ZONES. EXPECT CIRRUS CLOUDS THIS
AFTERNOON. CLOUDS SHOULD THICKEN AND LOWER THROUGH THE EVENING TO
AROUND 6 TO 9 THOUSAND FT AND AROUND 5 THOUSAND FT BY 12Z FRI. MVFR
CONDITIONS POSSIBLE FOR FRI. OTHERWISE VFR CONDITIONS EXPECTED THIS
AFTERNOON AND TONIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...JR
LONG TERM...JR/HOPPES
AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS BISMARCK ND
303 PM CDT THU APR 23 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 303 PM CDT THU APR 23 2015
SHOWERS THIS AFTERNOON THROUGH TONIGHT HIGHLIGHT THE SHORT TERM
FORECAST.
OUTSIDE OF THE HIGHWAY 200 CORRIDOR...THE MAJORITY OF
PRECIPITATION IS NOT REACHING THE GROUND DUE TO DRY AIR IN THE
SUB-800 MB LAYER. THE 16-18 UTC HRRR ITERATIONS HAVE THE BEST
HANDLING OF THE ONGOING PRECIPITATION...ESPECIALLY THAT WHICH IS
REACHING THE GROUND...AND WILL WEIGH HEAVILY ON THEIR SOLUTIONS
THROUGH AFTERNOON AND EVENING. THEREAFTER...THE 12 AND INCOMING 18
UTC GLOBAL AND HIGH RESOLUTION SUITES ARE IN AGREEMENT ON ELEVATED
SHOWERS DEVELOPING TONIGHT ACROSS THE JAMES AND INTO THE RED RIVER
VALLEYS BY 05 UTC WITH A MODEST LOW LEVEL JET AHEAD OF THE
SURFACE LOW ACROSS WESTERN SOUTH DAKOTA. GIVEN MARGINALLY POSITIVE
SHOWALTER VALUES...WILL NOT PUT IN THUNDER AT THIS TIME. FRIDAY
APPEARS TO BE DRY ACROSS WESTERN AND CENTRAL NORTH DAKOTA BETWEEN
THE STRONGER LOW ACROSS THE CENTRAL PLAINS AND THE PACIFIC
NORTHWEST TROUGH.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 303 PM CDT THU APR 23 2015
A SPLIT FLOW THROUGH THE WEEKEND WITH PERIODS OF INTERACTION
BETWEEN THE SOUTHERN STREAM AND NORTHERN STREAM. THIS WILL
ULTIMATELY SET UP AN INCREASINGLY WET/UNSETTLED WEATHER PATTERN
THROUGH EARLY NEXT WEEK. TWO MAIN SHORTWAVES TO PUSH ACROSS WESTERN
AND CENTRAL NORTH DAKOTA FRIDAY NIGHT THROUGH MONDAY. THE LATEST
ECMWF IS ADVERTISING A MORE CONTINUOUS RAIN OVER THE WEEKEND INTO
MONDAY...WHILE THE GFS/CANADIAN GEM HAS A MORE DISTINCT START/END
TIME WITH EACH WAVE. UTILIZED A BLEND OF THE ABOVE MODELS ABOVE.
EXPECT A BRIEF DRYING AND WARMING TREND BY MIDWEEK...THEN A
PROGRESSIVE AND POSSIBLY UNSETTLED WEATHER PATTERN SETTING UP LATE
IN THE EXTENDED.
FOR FRIDAY NIGHT THROUGH SATURDAY...A TRANSITORY 700MB-500MB RIDGE
DEVELOPS OUT AHEAD OF AN APPROACHING SHORTWAVE TROUGH SLIDING INTO
THE NORTHERN ROCKIES. THIS SHOULD KEEP CONDITIONS DRY FOR MOST AREAS
FRIDAY NIGHT BEFORE EAST TO SOUTHEAST WINDS ADVECT AN AREA OF
MOISTURE INTO THE WEST. THIS MOISTURE WILL CONVERGE INTO AN
APPROACHING SURFACE COLD FRONT IN EASTERN MONTANA. THUS POPS BECOME
LIKELY THEN CATEGORICAL SATURDAY IN THE WEST...WITH DRIER CONDITIONS
IN THE EAST AS MID LEVEL RIDGING REMAINS INTACT UNTIL 00Z SUNDAY.
SATURDAY NIGHT THROUGH MONDAY NIGHT...AS MENTIONED ABOVE THERE ARE
DIFFERENCES IN THE ECMWF AND GFS/GEM...ESPECIALLY SATURDAY NIGHT
THROUGH SUNDAY. PER GFS/GEM...THE SURFACE LOW/COLD FRONT AND SHORTWAVE
MOVE INTO SOUTHERN CANADA WITH SHOWERS DIMINISHING SATURDAY NIGHT
INTO SUNDAY. THE TRAILING COLD FRONT STALLS UNDER A SOUTHWEST FLOW
ALOFT...WITH LOW LEVEL SOUTH TO SOUTHEAST WINDS FEEDING MOISTURE
INTO NORTH DAKOTA. THE GFS/GEM MODELS TREND TOWARD A CESSATION TO
THE PRECIPITATION UNTIL SUNDAY NIGHT WHEN THE THE FRONT BECOMES
RE-ENERGIZED AS THE NEXT SHORTWAVE TROUGH APPROACHES. WITH THE
SURFACE COLD FRONT AND SOUTHERN STREAM MOISTURE ALREADY IN
PLACE...THIS SETS THE STAGE FOR A MORE WIDESPREAD PRECIPITATION
EVENT SUNDAY NIGHT THROUGH MONDAY. AS MENTIONED ABOVE THE LATEST
ECMWF REALLY DOES NOT STOP THE PRECIPITATION WITH THE INITIAL
SHORTWAVE...RATHER KEEPS THE SURGE MAINLY CONTINUOUS IN THE WEST AND
SLOWLY SPREADS IT EAST AND NORTH THROUGH MONDAY. TOTAL PRECIPITATION
AMOUNTS COULD RANGE BETWEEN A HALF INCH TO ONE INCH IN THE WEST TO
AROUND A QUARTER OF AN INCH IN CENTRAL NORTH DAKOTA THROUGH MONDAY NIGHT.
MONDAY NIGHT THROUGH THURSDAY...GOOD AGREEMENT THAT PRECIPITATION
WILL BE EAST OF THE JAMES RIVER VALLEY BY 12Z TUESDAY FOLLOWED BY
UPPER RIDGING TUESDAY AND WEDNESDAY. WARM AIR ADVECTION RAMPS UP
LATE TUESDAY INTO WEDNESDAY...AHEAD OF AN ADVANCING COLD FRONT WHICH
IS FORECAST TO CROSS SOUTHERN CANADA WEDNESDAY AFTERNOON/EVENING. THE GFS
SHOWS SOME LIGHT PRECIPITATION DEVELOPING IN THE NORTH BEHIND THE
FRONT WEDNESDAY AFTERNOON. THE ECMWF IS ABOUT 6HRS SLOWER WITH THE
COLD FRONT...NOT ARRIVING INTO THE NORTHWEST UNTIL AROUND 00Z
THURSDAY. THURSDAY LOOKS DRY...ALTHOUGH THIS MAY BE BRIEF AS
THE NEXT SYSTEM IS ALREADY APPROACHING THURSDAY NIGHT INTO FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT |247 PM CDT THU APR 23 2015
SCATTERED RAIN SHOWERS ACROSS WESTERN AND CENTRAL NORTH DAKOTA
THIS AFTERNOON WILL CONTINUE TO MOVE EAST AND FADE WITH
SUNSET...BEFORE ADDITIONAL SHOWERS FORM TONIGHT NEAR KJMS AFTER 05
UTC. MVFR CONDITIONS IN RAIN POSSIBLE. OTHERWISE...VFR CONDITIONS
FOR THE 18 UTC CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AYD
LONG TERM...KS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS NORMAN OK
418 PM CDT THU APR 23 2015
.DISCUSSION...
STRATUS HAS INHIBITED HEATING ACROSS THE ENTIRE AREA TODAY WITH
PERSISTENT ESE LOW LEVEL FLOW BEHIND THE FRONT. DO NOT EXPECT ANY
STORMS BEFORE 00Z. HOWEVER...LATER TONIGHT A NOCTURNAL LLJ WILL
DEVELOP OVER CENTRAL OK ISENTROPIC ASCENT WILL FOLLOW. IN
ADDITION...A SUBTLE MID LEVEL SHORTWAVE TROUGH WILL ALSO MOVE OUT
OF THE PANHANDLE ~06Z. NAM AND RAP SOUNDINGS ALSO INDICATE AROUND
1500 J/KG OF ELEVATED CAPE NEAR 06-09Z WITH PLENTY OF DEEP LAYER
SHEAR PRESENT. WOULD NOT BE SURPRISED IF A COUPLE OF SEVERE
STORMS DEVELOP OVERNIGHT ACROSS CENTRAL/N CENTRAL OK. THEN...LATE
TONIGHT THROUGH LATE TOMORROW MORNING A MID LEVEL SHORTWAVE
TROUGH WILL LIFT OUT OF WEST TEXAS AND APPROACH THE SE RED RIVER
VALLEY. MODELS CONTINUE TO INDICATE SCATTERED ACTIVITY OVER OUR SE
ZONES THROUGH MOST OF THE DAY.
THE PREVIOUS WILL LIKELY LIMIT INSTABILITY AT LEAST ALONG THE
SOUTHERN HALF OF THE DRYLINE FRI AFT/EVE. FURTHER NORTH ALONG THE
DRYLINE...SOMEWHERE FROM AROUND OKC TO TO SWO TO PNC...THERE MAY
BE ENOUGH INSTABILITY FOR A FEW STORMS TO DEVELOP BEFORE THEY MOVE
EAST OUT OF AREA DURING THE EVENING HOURS. IF STORMS DO MANAGE TO
DEVELOP LATE TOMORROW AFTERNOON ALONG AND EAST OF I35...THEY WILL
LIKELY BECOME SEVERE WITH DAMAGING WINDS...HAIL...AND PERHAPS
TORNADOES POSSIBLE.
DRIER CONDITIONS ARE EXPECTED SATURDAY AND TEMPS WILL CLIMB WELL
ABOVE AVERAGE OVER THE SW AS STRONG DOWNSLOPE FLOW DEVELOPS AHEAD
OF A COLD FRONT SLOWLY STALLING OUT. MAXTS IN THE LOW 90S APPEAR
POSSIBLE FOR PORTIONS OF WESTERN N TX. THE ATTENTION THEN TURNS TO
LATE SUNDAY THROUGH MONDAY AS A FAIRLY DEEP UPPER LOW TRAVERSES NM
AND MOVES INTO THE SOUTHERN PLAINS MON AM. WILL CONTINUE TO SLOWLY
INCREASE POPS FOR EARLY NEXT WEEK WITH THIS SYSTEM. IT WILL DRY
OUT AND COOL OFF TUES-WED BEHIND A COLD FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 62 80 56 85 / 40 30 20 0
HOBART OK 61 84 55 87 / 20 10 0 0
WICHITA FALLS TX 64 84 58 89 / 20 20 10 0
GAGE OK 58 81 52 84 / 20 20 10 0
PONCA CITY OK 59 81 58 83 / 30 30 20 10
DURANT OK 63 79 62 88 / 30 70 40 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
26/03