Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/19/15
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
933 AM PDT Fri Apr 17 2015
.Synopsis...
Warm weekend then cooling trend into mid week. A weak weather
system will bring a slight chance of mountain showers and
thunderstorms this weekend into Monday. A cold upper level trough
moves into the area by mid week bringing cooler temperatures and a
chance of precipitation over all of interior Northern California.
&&
.Discussion...
Cooler morning in the Valley with light winds and mountains warmer
with a warmer air mass. Temperatures this afternoon will rise into
the mid 80s in the Valley and low 50s to low 70s in the mountains
which is about 10 to 15 degrees above normal for mid April.
Temperatures warm up a little more on Saturday with high in the
mid 80s to around 90 in the Valley and mid 50s to mid 70s in the
mountains. Similar temperatures are expected on Sunday then a
little cooler temperatures on Monday as trough approaches the area
and onshore flow increases. Air temperatures are warm but water
temperatures in rivers and lakes remains cold in the low 40s to
low 60s. People going in the rivers and lakes this weekend should
use caution since cold water can lead to hypothermia.
A weak disturbance moves into Northern California on Saturday then
forms a weak upper level low off the Nor Cal coast late Saturday
into Sunday. This will bring some instability for a slight chance
of showers and thunderstorms over the mountains of interior
Northern California on Saturday and Sunday, mainly in the afternoons
and evenings. The best chance on Sunday looks like it will be over
the Sierra as the disturbance moves southwest. Upper level trough
trough digs offshore of the West Coast on Monday for continued
instability over the mountains for a slight chance of showers and
thunderstorms.
.Extended Discussion (Tuesday through Friday)
Mid range models zeroing in on idea of bringing weak Pacific
trough onto the coast around Tuesday although ECMWF and GEM still
have trough axis slightly offshore Tuesday afternoon. Rather
limited moisture with this system will limit precipitation mainly
to the mountain areas. GFS shows enough instability with this
system Tuesday afternoon to warrant slight thunderstorm threat as
well. Models all now pretty much centering the upper trough over
the west coast by Wednesday morning so entire CWA has at least a
slight threat of showers throughout the day Wednesday. GFS shows
most of the instability has moved into Nevada by Wednesday but
still somewhat borderline over central California so may need to
readdress thunderstorm threat for Wednesday as we get closer.
Weather change that appears fairly certain is the significant cool
off expected Tuesday and Wednesday. Forecast highs between Monday
and Wednesday showing a drop of anywhere from 15 to 20 degrees so
this change will be quite noticeable with highs dropping to around
normal for this time of year by mid week. Models vary a bit on
positioning of low/trough on Thursday but whichever solution
verifies...cyclonic flow over the region should continue the
shower threat CWA wide. Extended models showing a transition to northerly
flow aloft over the north state by Friday as upper system shifts
into the Great Basin. As a result...shower threat shifts eastward
with main precipitation threat from RAP around moisture over the
Sierra. Daytime temperatures rebound a bit but still close to
normal compared to very warm temperatures expected early in the
week.
&&
.Aviation...
VFR conditions next 24 hours. Isolated thunderstorms possible over
the mountains after 18z Saturday. Winds generally below 15 knots
except in vicinity of thunderstorms.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
241 AM PDT Fri Apr 17 2015
.Synopsis...
Very warm temperatures through the weekend. A weak weather system
will bring a slight chance of mountain showers or an isolated
thundertorm this weekend. Temperatures then start cooling Monday
through Wednesday with a chance of rain most areas.
&&
.Discussion...
Very little change to previous forecast. Very warm conditions will
continue today through Sunday. A weak upper disturbance will move
into the area this weekend. It will bring some instability with it
for just a slight chance of mainly afternoon and evening showers
or a thunderstorm both Saturday and Sunday.
Troughing still forecast to start carving out over the area on
Monday which will allow temperatures to begin cooling. Moisture
chances Monday look to remain only in the higher terrain. Rasch
.Extended Discussion (Tuesday through Friday)
Mid range models zeroing in on idea of bringing weak Pacific
trough onto the coast around Tuesday although ECMWF and GEM still
have trough axis slightly offshore Tuesday afternoon. Rather
limited moisture with this system will limit precipitation mainly
to the mountain areas. GFS shows enough instability with this
system Tuesday afternoon to warrant slight thunderstorm threat as
well. Models all now pretty much centering the upper trough over
the west coast by Wednesday morning so entire CWA has at least a
slight threat of showers throughout the day Wednesday. GFS shows
most of the instability has moved into Nevada by Wednesday but
still somewhat borderline over central California so may need to
readdress thunderstorm threat for Wednesday as we get closer.
Weather change that appears fairly certain is the significant cool
off expected Tuesday and Wednesday. Forecast highs between Monday
and Wednesday showing a drop of anywhere from 15 to 20 degrees so
this change will be quite noticeable with highs dropping to around
normal for this time of year by mid week. Models vary a bit on
positioning of low/trough on Thursday but whichever solution
verifies...cyclonic flow over the region should continue the
shower threat CWA wide. Extended models showing a transition to northerly
flow aloft over the north state by Friday as upper system shifts
into the Great Basin. As a result...shower threat shifts eastward
with main precipitation threat from RAP around moisture over the
Sierra. Daytime temperatures rebound a bit but still close to
normal compared to very warm temperatures expected early in the
week.
&&
.Aviation...
VFR conditions next 24 hours. Isolated thunderstorms possible over
the mountains after 18z Saturday. Winds generally below 15 knots
except in vicinity of thunderstorms.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
749 PM MDT SAT APR 18 2015
.UPDATE...
ISSUED AT 750 PM MDT SAT APR 18 2015
UPPER LEVEL LOW NOW OVER FAR EASTERN COLORADO AND WILL MOVE INTO
WESTERN KANSAS OVERNIGHT. THE SHOWERS AND THUNDERSTORMS HAVE
DECREASED THIS EVENING AS THE AIRMASS HAS STABILIZED SOME. STILL
EXPECT SHOWERS TO INCREASE OVERNIGHT ON THE BACKSIDE OF THE LOW.
WILL CONTINUE WITH HIGH POPS THIS EVENING AND OVERNIGHT. FOR THE
MOUNTAINS...FAVORED AREAS WILL SEE 3 TO 6 INCHES WITH LESS
ELSEWHERE. FOR THE FRONT RANGE AND EASTERN PLAINS...SNOW LEVEL
WILL START OFF ABOVE 6000 FEET...BUT LOWER OVERNIGHT AS THE
AIRMASS COOLS. COULD SEE AN INCH OR TWO OF SLUSHY ACCUMULATION
ALONG THE PALMER DIVIDE AND NEAR THE FOOTHILLS BY DAY BREAK. WINDS
WILL INCREASE TONIGHT AS THE LOW MOVES OFF. MAY SEE GUSTS OF 40 TO
50 MPH OVER THE PLAINS LATE TONIGHT AND EARLY SUNDAY. WILL
INCREASE WINDS IN THE FORECAST A LITTLE MORE. ON SUNDAY...EXPECT
DRIER AIR TO MOVE OVER THE PLAINS AND BRING THE SHOWERS TO AN END
DURING THE MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 322 PM MDT SAT APR 18 2015
UPPER LEVEL LOW HAS MADE VERY LITTLE EASTWARD PROGRESS TODAY AND
IS STILL LOCATED OVER SOUTHWEST WASHINGTON COUNTY...BASED ON THE
RECENT MOTION OF RADAR ECHOES. AFTERNOON HEATING AND COLD
TEMPERATURES ALOFT HAVE DE-STABILIZED THE AIRMASS ENOUGH FOR
EMBEDDED THUNDERSTORMS TO DEVELOP OVER THE FAR NORTHEAST PLAINS.
MOUNTAIN AREAS HAVE BEEN PICKING UP SCATTERED SNOW SHOWERS...BUT
NOT MUCH NEW SNOW ACCUMULATION...BASED ON WEB CAMERAS AND SNOTEL
DATA.
THE SHOWERS AND THUNDERSTORMS THIS EVENING SHOULD TAPER IN THE
EVENING...WITH THE LOSS OF DAYTIME HEATING. ADDITIONAL SHOWERS ARE
EXPECTED OVERNIGHT AS THE UPPER LOW MOVES EASTWARD AND THE RETURN
FLOW ON THE BACKSIDE OF THE LOW MOVES OUT OF THE MOUNTAINS AND
ACROSS THE PLAINS. THE NAM AND RAP FORECASTS HAVE RAIN OCCURRING
THROUGH MOST OF THE NIGHT AND THEN A DECREASE IN SHOWER ACTIVITY
BY MIDDAY SUNDAY. TEMPERATURES OVERNIGHT WILL DROP TO THE MID AND
UPPER 30S ON THE PLAINS WHICH MAY BE COOL ENOUGH FOR SOME SNOW TO
FALL. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED THOUGH. SUNDAY
WILL BE A MIX OF MORNING SHOWERS AND THEN DECREASING CLOUDS IN THE
AFTERNOON. STRONG INSOLATION SHOULD ALLOW AFTERNOON TEMPERATURES
TO CLIMB INTO THE LOWER 50S. MOUNTAIN AREAS COULD SEE SCATTERED
SNOW SHOWERS CONTINUE AS WE REMAIN UNDER MOIST NORTHWESTERLY FLOW.
SNOW ACCUMULATIONS SHOULD BE LESS THAN 3 OR 4 INCHES.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 322 PM MDT SAT APR 18 2015
A COLD NORTHWEST FLOW ON THE BACK SIDE OF EXITING
LONG WAY UPPER TROUGH DRIVES A CLIPPER TYPE DISTURBANCE SOUTHWARD
OUT OF WYOMING SUNDAY NIGHT AND MONDAY MORNING ACCORDING TO
DETERMINISTIC MODELS. SYSTEM APPEARS TO PACK ADJACENT COLD
AIR...MOISTURE AND OROGRAPHIC LIFT TO PRODUCE ANOTHER ROUND OF LIGHT
SNOW ACCUMULATION IN THE HIGHER MTN RANGES. MTN PASSES AND EXPOSED
NORTHWEST SLOPES COULD SEE ANYWHERE FROM 2-5 INCHES OF ADDITIONAL
SNOW ACCUMULATION BY MONDAY EVENING. WETBULB TEMP IS PROGGED TO BE
LOW ENOUGH FOR A RAIN/SNOW MIX ON THE NEAR BY PLAINS SUNDAY
EVENING...AND POSSIBLY ALL SNOW LATE SUNDAY NIGHT INTO MONDAY
MORNING. THIS SYSTEM DOES NOT LOOK LIKE A BIG PRECIP MAKER FOR THE
PLAINS AND ANY SNOW THAT FALLS AT LOWER ELEVATIONS SHOULD NOT
ACCUMULATE.
MODELS SHOW THIS DISTURBANCE QUICKLY MOVING OUT OF THE FCST AREA
DURING THE DAY MONDAY AND WITH LOW LEVEL WINDS TURNING WESTERLY...
TEMPS SHOULD MANAGE TO REACH THE 50S ON THE PLAINS WITH SUNSHINE
RETURNING LATE IN THE DAY.
MODELS SHOW A BREAK IN THE COOL AND WET NWLY FLOW PATTERN TUESDAY
INTO WEDNESDAY WHEN A DIRTY SHORTWAVE UPPER RIDGE OVER THE GREAT
BASIN WORKS ITS WAY ACROSS COLORADO. GFS AND NAM INDICATE A FAIR
AMOUNT OF MID AND HIGH LEVEL MOISTURE WITH THIS RIDGE...SUFFICIENT
TO WARRANT A CHANCE OF RAIN/SNOW SHOWERS IN THE HIGH COUNTRY ON
TUESDAY AND AGAIN BY WEDNESDAY AFTERNOON. LATE DAY SHOWERS ON
WEDNESDAY COULD BE ACCOMPANIED BY SOME THUNDER DURING THE WARMEST
TIME OF THE DAY. ON THE PLAINS...DRY CONDITIONS WILL PREVAIL WITH A
PREVAILING W-SWLY LOW LEVEL FLOW. AS A RESULT...TEMPS REBOUND WITH
AFTN READINGS 1-5 DEG F ABOVE AVERAGE ON TUES AND 5-10 DEG ABOVE
AVERAGE BY WED. LATE ON WEDNESDAY UPPER RIDGE OVER COLORADO APPEARS
TO FLATTEN OUT WITH MODELS SHOWING A WEAK SHORTWAVE TROUGH ZOOMING
UP FROM THE DESERT SOUTHWEST AND THEN ROUNDING THE TOP OF RIDGE.
SHOULD THIS HAPPEN...CAN SEE PRECIP CHANCES ON THE RISE AGAIN ACRS
THE CWA WITH RAIN/SNOW IN THE HIGH COUNTRY AND RAIN SHOWERS ON THE
PLAINS. THERE/S ALSO A SLIGHT CHANCE OF T-STORMS BY EVENING.
THURSDAY AND BEYOND...LARGE SCALE FLOW PATTERN OVER THE WESTERN
CONUS IS PROGGED TO BECOME MORE LIVELY WITH YET ANOTHER LARGE SCALE
UPPER TROUGH MAKING ITSELF FELT IN THE GREAT BASIN WEDNESDAY INTO
THURSDAY AND ACROSS THE NORTH CENTRAL AND NORTHEAST THURSDAY AND
FRIDAY. WITH AS MUCH MOISTURE AND COOL AIR WITH THIS SYSTEM...WILL
CONTINUE LOW POPS FOR ALL AREAS RIGHT THROUGH SATURDAY.
&&
.AVIATION...(FOR THE TAFS THROUGH 06Z SUNDAY EVENING)
ISSUED AT 750 PM MDT SAT APR 18 2015
SHOWERS AND THUNDERSTORMS HAVE DECREASED THIS EVENING AS THE
AIRMASS HAS STABILIZED. ADDITIONAL RAIN AND SNOW SHOWERS ARE
EXPECTED OVERNIGHT DUE TO LIFT FROM THE UPPER LEVEL LOW. LITTLE
TO NO SNOW ACCUMULATION IS EXPECTED. THE BEST CHANCE FOR SNOW
ACCUMULATION WILL BE AT KAPA. NORTHERLY WINDS WILL PREVAIL
THROUGH SUNDAY AND BE GUSTY AT TIMES WITH GUSTS TO 30 KNOTS
LATE TONIGHT AND SUNDAY. CEILINGS WILL FALL TO 1500 TO 3000 AS
THE SHOWER ACTIVITY PUSHES THROUGH. CEILINGS WILL THEN SLOWLY RISE
SUNDAY MORNING TO ABOVE 6000 FEET BY 20Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MEIER
SHORT TERM...DANKERS
LONG TERM...BAKER
AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
744 PM MDT SAT APR 18 2015
.UPDATE...
ISSUED AT 744 PM MDT SAT APR 18 2015
UPPER LOW CONTINUES TO ROTATE IN PLACE OVER THE EASTERN PLAINS
THIS EVENING. WRAP AROUND MOISTURE KEEPING SNOW GOING IN THE HIGH
COUNTRY...A MIXTURE ACROSS THE MESA AND PLATEAU REGION AND
THUNDERSTORMS ACROSS EASTERN UTAH. STEEP LAPSE RATES DUE TO
HEATING OUTSIDE OF THE THICKER CLOUD SHIELD IS AIDING THE WEAK
WAVE DROPPING THROUGH EASTERN UTAH. STORMS STARTED OUT QUITE
ROBUST WEST OF THE COLORADO RIVER...BUT AS THEY TRAVEL SOUTHEAST
ACROSS THE INSTABILITY GRADIENT...THEY WEAKEN OVER OUR CWA. WILL
LOSS OF HEATING EXPECT THE COVERAGE TO SLOWLY WANE OVER THE NEXT
HOUR OR SO. WILL BE WATCHING THE AFFECT OF NIGHTFALL ON EASTERN
PASSES AS MELTING HAS KEPT ROADS IN DECENT SHAPE. MAY KEEP SOME
OF THE HEADLINES ALONG DIVIDE IF NECESSARY PAST MIDNIGHT. LASTLY
DEW POINTS DID CREEP UP A BIT THIS AFTERNOON INTO THE 40S OVER THE
WESTERN VALLEYS. WILL BE MONITORING THE THREAT OF DENSE FOG
AS WELL.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 325 PM MDT SAT APR 18 2015
THE LOW PRESSURE RESPONSIBLE FOR THE MUCH NEEDED PRECIP OVER THE
LAST FEW DAYS IS NOW LOCATED OVER THE FRONT PLAINS WHILE CYCLONIC
FLOW CONTINUES TO PUMP IN MOISTURE FROM THE NORTH TO SOUTH. THIS
FLOW STARTS IN NERN WY AND THE PLUME REACHES AS FAR SOUTH AS THE
SAN JUANS. SNOW AND RAIN HAS FALLEN MUCH OF THE DAY UNDER THIS
PLUME OF MOISTURE AND WILL CONTINUE TO DO SO THROUGH THIS EVENING.
CURRENT WINTER HIGHLIGHTS LOOK GOOD SO NO CHANGES THERE. AN UPPER
LEVEL DISTURBANCE OVER SRN CANADA IS TRAILING A TROUGH THAT IS
CAUSING THE AREA OF LOW PRESSURE TO KEEP MOVING EWRD. THE REASON
THIS IS HAPPENING SO SLOWLY IS THE LACK OF ANY STRONG JET FEATURES
TO REALLY GET THIS SYSTEM MOVING. EVEN SO...THE CLOUD SHIELD/PLUME
WILL BRING MORE PRECIP TO THE AREA AS THE ATTENDANT LOW PRESSURE
MEANDERS EAST. BY MIDNIGHT...PRECIP WILL FAVOR THE NRN AND CENTRAL
MTNS ALONG WITH THE FLATTOPS DUE TO THEIR FAVORABLE LOCATION SO
ADDITIONAL ACCUMULATIONS STILL POSSIBLE UP THERE. THE REST OF THE
CWA MAY SEE AN ODD SHOWER OR TWO BUT NOTHING TOO SIGNIFICANT.
BY SUNDAY...THE CANADIAN LOW WILL BE JUST TO THE NORTH OF
MINNESOTA WHILE HIGH PRESSURE BUILDS INTO THE PACNW. THIS WILL
CAUSE OUR CWA TO BE SANDWICHED BETWEEN THESE TWO FEATURES. WEAK
PIECES OF ENERGY WILL DROP DOWN FROM THE NW POSSIBLY CAUSING SOME
PRECIP FOR THE CWA. THE GFS HIGHLIGHTING TWO DISTINCT WAVES...ONE
SUNDAY EVENING AND ANOTHER MONDAY MORNING. THE NAM12 ONLY SHOWING
SOME SPOTTY SHOWERS AT BEST WITH SOME CONVECTION THROWN IN. THE
HRRR AND RAP SHOWING MUCH LESS IN THE WAY OF PRECIP. THIS ALL
MEANS UNSETTLED WX WILL CONTINUE BUT WITH MUCH MORE DEFINITIVE
BREAKS BETWEEN DISTURBANCES. FORECAST BRINGS MOSTLY BENIGN
WEATHER SUNDAY WITH INCREASING CHANCES FOR PRECIP FROM
MIDAFTERNOON ONWARDS...MAINLY FAVORING THE CONTINENTAL DIVIDE.
TEMPS WILL WARM UP CONSIDERABLY TOMORROW THOUGH STILL REMAIN 5 TO
10 DEGREES BELOW NORMAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 325 PM MDT SAT APR 18 2015
UNSETTLED NW FLOW IS EXPECTED MONDAY AND TUESDAY. AN EMBEDDED WAVE
SHOULD FOCUS THE BEST CHANCE OF SHOWERS OVER THE NORTHERN AND
CENTRAL MOUNTAINS MONDAY AFTERNOON AND EVENING. DAYTIME INSTABILITY
WILL KEEP ISOLATED TO SCATTERED SHOWERS OVER THE MTNS ON TUESDAY.
TEMPORARY RIDGING DEVELOPS OVER THE AREA BY MIDWEEK AS A TROUGH
FORMS ALONG THE WEST COAST...WITH AN UPPER LOW OVER SRN CA BY THU
MORNING. ENOUGH RESIDUAL MOISTURE LINGERS FOR A FEW AFTERNOON
SHOWERS OR THUNDERSTORMS. FLOW ALOFT BECOMES SOUTHWEST...AND THE
SRN CA LIFTS ACROSS THE FOUR CORNERS/DESERT SOUTHWEST THU NIGHT
AND FRI MORNING. TIMING AND TRACK A BIT DIFFERENT BETWEEN MODELS
BUT STILL LOOKING LIKE A BETTER CHANCE OF PRECIPITATION WITH SOME
THUNDERSTORMS LATE NEXT WEEK. BOOSTED POPS FOR THU AFTERNOON
THROUGH FRI OVER THE BLENDED FORECAST GUIDANCE AS A RESULT.
GFS AND ECMWF SOLUTIONS CONTINUE TO DIVERGE ON SATURDAY. ECMWF MORE
AMPLIFIED AS IT DIGS A PAC NW TROUGH TO THE SRN GREAT BASIN BY
SATURDAY...RESULTING IN DOWNSTREAM RIDGING AND SW FLOW OVER OUR
AREA. GFS DROPS SOME ENERGY FROM THE PAC NW TROUGH DOWN THE WEST
COAST BUT SENDS MORE OF IT ACROSS THE NRN ROCKIES WITH WESTERLY
FLOW ACROSS UT/CO. WILL FOLLOW THE BLENDED GUIDANCE FOR SAT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 641 PM MDT SAT APR 18 2015
THE SLOW MOVING LOW PRESSURE SYSTEM WHICH HAS IMPACTED THE REGION
FOR THE LATTER PART OF THE WEEK WILL CONTINUE TO BRING PRECIPITATION
TO THE AREA TONIGHT. AIRPORTS WILL HAVE OCCASIONAL RAIN OR SNOW
SHOWERS RESULTING MVFR CIGS/VSBY WITH LOCALIZED IFR CONDITIONS.
MOUNTAINS WILL LARGELY BE OBSCURED IN CLOUDS AND SHOWERS. LATER
TONIGHT SOME AREAS MAY EXPERIENCE FOG CAPABLE OF YIELDING IFR
CONDITIONS. FOG WILL LINGER THROUGH 17Z THEN RAPIDLY DISSIPATE.
VFR CONDITIONS RETURN TO THE AREA SUNDAY AFTERNOON AS THE STORM
SHIFTS EAST. HOWEVER...MOUNTAIN SNOW SHOWERS WILL CONTINUE OVER
THE DIVIDE MOUNTAINS AND THE EASTERN UINTAS THOUGH IMPACTS ON
ADJACENT AIRPORTS IS UNLIKELY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT FOR COZ009-010-
012-017-018.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ003-
004-013.
UT...NONE.
&&
$$
UPDATE...15
SHORT TERM...TGR
LONG TERM...JAD
AVIATION...NL
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
641 PM MDT SAT APR 18 2015
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 325 PM MDT SAT APR 18 2015
THE LOW PRESSURE RESPONSIBLE FOR THE MUCH NEEDED PRECIP OVER THE
LAST FEW DAYS IS NOW LOCATED OVER THE FRONT PLAINS WHILE CYCLONIC
FLOW CONTINUES TO PUMP IN MOISTURE FROM THE NORTH TO SOUTH. THIS
FLOW STARTS IN NERN WY AND THE PLUME REACHES AS FAR SOUTH AS THE
SAN JUANS. SNOW AND RAIN HAS FALLEN MUCH OF THE DAY UNDER THIS
PLUME OF MOISTURE AND WILL CONTINUE TO DO SO THROUGH THIS EVENING.
CURRENT WINTER HIGHLIGHTS LOOK GOOD SO NO CHANGES THERE. AN UPPER
LEVEL DISTURBANCE OVER SRN CANADA IS TRAILING A TROUGH THAT IS
CAUSING THE AREA OF LOW PRESSURE TO KEEP MOVING EWRD. THE REASON
THIS IS HAPPENING SO SLOWLY IS THE LACK OF ANY STRONG JET FEATURES
TO REALLY GET THIS SYSTEM MOVING. EVEN SO...THE CLOUD SHIELD/PLUME
WILL BRING MORE PRECIP TO THE AREA AS THE ATTENDANT LOW PRESSURE
MEANDERS EAST. BY MIDNIGHT...PRECIP WILL FAVOR THE NRN AND CENTRAL
MTNS ALONG WITH THE FLATTOPS DUE TO THEIR FAVORABLE LOCATION SO
ADDITIONAL ACCUMULATIONS STILL POSSIBLE UP THERE. THE REST OF THE
CWA MAY SEE AN ODD SHOWER OR TWO BUT NOTHING TOO SIGNIFICANT.
BY SUNDAY...THE CANADIAN LOW WILL BE JUST TO THE NORTH OF
MINNESOTA WHILE HIGH PRESSURE BUILDS INTO THE PACNW. THIS WILL
CAUSE OUR CWA TO BE SANDWICHED BETWEEN THESE TWO FEATURES. WEAK
PIECES OF ENERGY WILL DROP DOWN FROM THE NW POSSIBLY CAUSING SOME
PRECIP FOR THE CWA. THE GFS HIGHLIGHTING TWO DISTINCT WAVES...ONE
SUNDAY EVENING AND ANOTHER MONDAY MORNING. THE NAM12 ONLY SHOWING
SOME SPOTTY SHOWERS AT BEST WITH SOME CONVECTION THROWN IN. THE
HRRR AND RAP SHOWING MUCH LESS IN THE WAY OF PRECIP. THIS ALL
MEANS UNSETTLED WX WILL CONTINUE BUT WITH MUCH MORE DEFINITIVE
BREAKS BETWEEN DISTURBANCES. FORECAST BRINGS MOSTLY BENIGN
WEATHER SUNDAY WITH INCREASING CHANCES FOR PRECIP FROM
MIDAFTERNOON ONWARDS...MAINLY FAVORING THE CONTINENTAL DIVIDE.
TEMPS WILL WARM UP CONSIDERABLY TOMORROW THOUGH STILL REMAIN 5 TO
10 DEGREES BELOW NORMAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 325 PM MDT SAT APR 18 2015
UNSETTLED NW FLOW IS EXPECTED MONDAY AND TUESDAY. AN EMBEDDED WAVE
SHOULD FOCUS THE BEST CHANCE OF SHOWERS OVER THE NORTHERN AND
CENTRAL MOUNTAINS MONDAY AFTERNOON AND EVENING. DAYTIME INSTABILITY
WILL KEEP ISOLATED TO SCATTERED SHOWERS OVER THE MTNS ON TUESDAY.
TEMPORARY RIDGING DEVELOPS OVER THE AREA BY MIDWEEK AS A TROUGH
FORMS ALONG THE WEST COAST...WITH AN UPPER LOW OVER SRN CA BY THU
MORNING. ENOUGH RESIDUAL MOISTURE LINGERS FOR A FEW AFTERNOON
SHOWERS OR THUNDERSTORMS. FLOW ALOFT BECOMES SOUTHWEST...AND THE
SRN CA LIFTS ACROSS THE FOUR CORNERS/DESERT SOUTHWEST THU NIGHT
AND FRI MORNING. TIMING AND TRACK A BIT DIFFERENT BETWEEN MODELS
BUT STILL LOOKING LIKE A BETTER CHANCE OF PRECIPITATION WITH SOME
THUNDERSTORMS LATE NEXT WEEK. BOOSTED POPS FOR THU AFTERNOON
THROUGH FRI OVER THE BLENDED FORECAST GUIDANCE AS A RESULT.
GFS AND ECMWF SOLUTIONS CONTINUE TO DIVERGE ON SATURDAY. ECMWF MORE
AMPLIFIED AS IT DIGS A PAC NW TROUGH TO THE SRN GREAT BASIN BY
SATURDAY...RESULTING IN DOWNSTREAM RIDGING AND SW FLOW OVER OUR
AREA. GFS DROPS SOME ENERGY FROM THE PAC NW TROUGH DOWN THE WEST
COAST BUT SENDS MORE OF IT ACROSS THE NRN ROCKIES WITH WESTERLY
FLOW ACROSS UT/CO. WILL FOLLOW THE BLENDED GUIDANCE FOR SAT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 641 PM MDT SAT APR 18 2015
THE SLOW MOVING LOW PRESSURE SYSTEM WHICH HAS IMPACTED THE REGION
FOR THE LATTER PART OF THE WEEK WILL CONTINUE TO BRING PRECIPITATION
TO THE AREA TONIGHT. AIRPORTS WILL HAVE OCCASIONAL RAIN OR SNOW
SHOWERS RESULTING MVFR CIGS/VSBY WITH LOCALIZED IFR CONDITIONS.
MOUNTAINS WILL LARGELY BE OBSCURED IN CLOUDS AND SHOWERS. LATER
TONIGHT SOME AREAS MAY EXPERIENCE FOG CAPABLE OF YIELDING IFR
CONDITIONS. FOG WILL LINGER THROUGH 17Z THEN RAPIDLY DISSIPATE.
VFR CONDITIONS RETURN TO THE AREA SUNDAY AFTERNOON AS THE STORM
SHIFTS EAST. HOWEVER...MOUNTAIN SNOW SHOWERS WILL CONTINUE OVER
THE DIVIDE MOUNTAINS AND THE EASTERN UINTAS THOUGH IMPACTS ON
ADJACENT AIRPORTS IS UNLIKELY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT FOR COZ009-010-
012-017-018.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ003-
004-013.
UT...NONE.
&&
$$
SHORT TERM...TGR
LONG TERM...JAD
AVIATION...NL
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1107 AM MDT FRI APR 17 2015
.UPDATE...
ISSUED AT 1010 AM MDT FRI APR 17 2015
THE UPPER LOW OVER THE SW QUAD OF THE STATE IS CONTINUING TO SWEEP
HEAVY SNOWFALL BACK INTO THE LAKE AND CHAFFEE COUNTY AREAS...AS
PER LATEST SATELLITE IMAGERY AND SPOTTER REPORTS.
THEREFORE...UPGRADED EXISTING SNOW ADVISORIES FOR LOWER PORTIONS
OF LAKE AND CHAFFEE COUNTIES TO A WINTER STORM WARNING...IN EFFECT
UNTIL 12Z TOMORROW MORNING. MOORE
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM MDT FRI APR 17 2015
THERE ARE SEVERAL CONCERNS FOR THE SHORT TERM FORECAST...INCLUDING
THE POTENTIAL FOR CRITICAL FIRE WX CONDITIONS...THE POTENTIAL FOR
SEVERE STORMS AND SNOW AMOUNTS.
STILL SEE OCNL LIGHTNING STRIKES OVR SERN CO THIS MORNING.
SATELLITE IMAGES SHOW THE UPR LOW CENTERED OVR NWRN NM THIS
MORNING...AND IT IS FORECAST TO MOVE NORTHEASTWARD TODAY AND
TONIGHT. BY 12Z SAT...THE NAM...GFS AND ECMWF SHOW THE LOW CENTER
IN DIFFERENT LOCATIONS. THE GFS AND ECMWF ARE FAIRLY SIMILAR WITH
THE LOW ABOUT OVR THE PALMER DVD...THE GFS IS A LITTLE FARTHER E AND
S THAN THE ECMWF. THE NAM HAS THE LOW CENTER AT 12Z SAT OVR NRN
SAGUACHE COUNTY.
FOR THE FIRST HALF OF TODAY THE MODELS SHOW CONTINUED MOIST EASTERLY
FLOW ACRS THE PIKES PEAK REGION...FREMONT COUNTY AND LAKE AND
CHAFFEE COUNTIES...WITH SOME PCPN ALSO OVR THE SW MTNS AND SRN
PORTIONS OF THE ERN MTNS...JUST NOT AS HEAVY AS NRN AREAS. AT THE
SAME TIME...A DRY SLOT WL WORK ITS WAY INTO THE SERN PLAINS.
HOWEVER...THE NAM HAS AN AREA OF CONVECTION DEVELOPING...MAINLY N OF
HIGHWAY 50 OVR THE ERN PLAINS THIS AFTERNOON...WITH LAS ANIMAS AND
BACA COUNTIES REMAINING DRY. THE GFS AND HRRR ARE DRY THIS AFTERNOON
OVR THE FAR SERN PLAINS. STRONG SOUTHERLY WINDS OVR BACA AND LAS
ANIMAS COUNTIES...ALONG WITH RH VALUES DROPPING BELOW 15 PERCENT ARE
EXPECTED THIS AFTERNOON SO WL ISSUE A RED FLAG WARNING FOR THESE
LOCATIONS. PORTIONS OF SRN PROWERS AND BENT COUNTIES MAY ALSO REACH
RED FLAG CRITERIA...BUT UNCERTAINTY ABOUT PCPN OVR THESE COUNTIES WL
KEEP ME FROM ISSUING A FIRE HIGHLIGHT AT THIS TIME. THE NAM
DECREASES PCPN OVR MANY OF THE MTN AREAS THIS AFTERNOON...WHILE IT
STILL LOOKS GOOD ON THE GFS OVR THE NRN MTNS PORTIONS OF THE CWA.
THE ECMWF DECREASES PCPN OVR THE PIKES PEAK REGION BUT KEEPS GOOD
PCPN GOING OVR LAKE AND CHAFFEE COUNTIES.
THE GFS IS MUCH DRIER AT THE SFC THIS AFTERNOON OVR THE FAR SERN
PLAINS THAN THE NAM...WHICH MAKES A DIFFERENCE IN THE POTENTIAL FOR
SEVERE WX. WL LEAN THE FORECAST A LITTLE MORE TOWARD THE NAM OVR
PROWERS...BENT...AND KIOWA COUNTIES. IF THE NAM IS CORRECT...CAPE
VALUES COULD RANGE FROM ABOUT 600-1500 J/KG OVR PROWERS...NRN BENT
AND KIOWA COUNTIES...WITH 0-6KM SHEAR VALUES OF 50-60 KTS...AND WE
COULD SEE A COUPLE SEVERE STORMS. THE HRRR ALSO SETS UP A DRYLINE
MAINLY NORTH OF HIGHWAY 50S THIS AFTERNOON OVR THE FAR SERN PLAINS.
HOWEVER...IF THE DRIER GFS IS CORRECT THE BETTER MSTR AND SVR
CHANCES WL BE EAST OF THE AREA.
TONIGHT AS THE UPR LOW CONTINUES TO LIFT NORTHEASTWARD...MUCH OF THE
SERN PLAINS LOOK TO BE DRY...WITH MANY OF THE MTN AREAS STILL SEEING
SOME PCPN. ALTHOUGH THE DIFFERING POSITIONS OF THE UPR LOW CENTER
RESULT IN DIFFERENCES IN WHAT MTNS AREAS WL HAVE THE BEST PCPN
CHANCES. WILL NOT MAKE ANY CHANGES TO THE WINTER WEATHER HIGHLIGHTS
THIS MORNING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 410 AM MDT FRI APR 17 2015
SATURDAY-SUNDAY...LATEST MODELS REMAIN IN DECENT AGREEMENT OF STRONG
UPPER LOW ACROSS SOUTH CENTRAL COLORADO EARLY SATURDAY SLOWLY
LIFTING NORTH AND EAST THROUGH SATURDAY NIGHT WITH THE SYSTEM THEN
WEAKENING AND MERGING WITH A BROAD UPPER TROUGH TRANSLATING ACROSS
THE NORTHERN TIER OF STATES. BEST CHANCES OF PRECIPITATION EARLY
SATURDAY REMAINS ACROSS THE CONTDVD THROUGH THE SOUTHERN MTS WITH
DEVELOPING WRAPAROUND PRECIPITATION SHIELD AND DEVELOPING NORTHWEST
FLOW BEHIND THE PASSING SYSTEM. SHOULD SEE ISOLATED TO SCATTERED
SHOWERS AND A FEW EMBEDDED THUNDERSTORMS ACROSS THE EASTERN PLAINS
SATURDAY AFTERNOON AND EVENING WITH COLD CORE UPPER LOW TRANSLATING
INTO NORTHEASTERN COLORADO. MAY NEED TO EXTEND OR ADD WINTER
HIGHLIGHTS ACROSS THE CENTRAL MTS INTO SATURDAY WITH SEVERAL INCHES
OF SNOW EXPECTED...ESPECIALLY AOA 10KT FEET. MID LEVEL TEMPS SLOWLY
WARM SATURDAY AS THE SYSTEM LIFTS OUT ACROSS THE AREA AND SHOULD SEE
HIGHS SLIGHTLY WARMER AS A RESULT...THOUGH STILL BELOW SEASONAL
AVERAGES.
PASSING UPPER SYSTEM ACROSS THE AREA LATE SATURDAY SENDS A COLD
FRONT ACROSS THE EASTERN PLAINS EARLY SUNDAY MORNING...WITH GUSTY
NORTH TO NORTHWEST WINDS OF 20 TO 40 MPH EXPECTED IN ITS WAKE...WITH
THE STRONGEST WINDS EXPECTED ACROSS THE FAR EASTERN PLAINS. A MINOR
WAVE EMBEDDED WITHIN THE NORTHWEST FLOW ALOFT SUPPORTS ISOLATED TO
SCATTERED SHOWERS ACROSS THE AREA ON SUNDAY...WITH TEMPERATURES
SLIGHTLY COOLER THAN SATURDAY.
MONDAY-TUESDAY...EMBEDDED DISTURBANCES IN THE SLOWLY MODERATING
NORTHWEST FLOW ACROSS THE AREA WILL KEEP ISOLATED TO SCATTERED
MAINLY AFTERNOON AND EVENING SHOWERS IN THE FORECAST WITH
TEMPERATURES WARMING BACK TO NEAR SEASONAL AVERAGES.
WEDNESDAY-THURSDAY...A REX LIKE BLOCKING PATTERN LOOKS TO SET UP
ACROSS THE REGION WITH RIDGING ACROSS THE ROCKIES AND TROUGHS
SETTING UP OVER THE COASTS. THIS LOOKS TO KEEP UNSETTLED WEATHER
ACROSS THE AREA WITH COOL HIGH PRESSURE ACROSS THE MIDWEST KEEPING
UPSLOPE FLOW IN PLACE ACROSS EASTERN COLORADO ALONG WITH INCREASING
MOISTURE WITHIN DEVELOPING SOUTHWEST FLOW ALOFT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1102 AM MDT FRI APR 17 2015
DRY AIR IS SPREADING ACROSS SOUTHERN AND EASTERN PORTIONS OF
COLORADO RESULTING IN VFR CONDITIONS AT ALL THREE TAF SITES.
MEANWHILE...WRAPPED UP INTENSE UPPER LOW WILL KEEP IFR TO LIFR AND
HEAVY SNOW CONTINUING ACROSS THE CENTRAL MTS. GENERALLY SOUTHERLY
WINDS CAN BE EXPECTED AT THE TAF SITES TODAY...THOUGH SHOWERS MAY
SPREAD OFF THE MOUNTAINS INTO THE KCOS TAF SITE DURING THE
AFTERNOON. IF THEY AFFECT THE TERMINAL...THEY SHOULD BE SHORT
LIVED AND GIVEN THE ANTICIPATED SPOTTY NATURE...KCOS TAF WILL
CARRY VCSH IN THE LATE AFTN/EARLY EVENING HOURS. WINDS WILL SHIFT
OUT OF THE NORTH LATER TONIGHT FOR KCOS AND KPUB TAF SITES WITH
WINDS GENERALLY UNDER 15 KTS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 AM MDT SATURDAY FOR COZ058>063-072-
073-080-082.
WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR
COZ077>079-084.
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ233-237.
WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT FOR COZ076-081.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT SATURDAY FOR COZ074-075.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ066.
&&
$$
UPDATE...MOORE
SHORT TERM...28
LONG TERM...MW
AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1014 AM MDT FRI APR 17 2015
.UPDATE...
ISSUED AT 1010 AM MDT FRI APR 17 2015
THE UPPER LOW OVER THE SW QUAD OF THE STATE IS CONTINUING TO SWEEP
HEAVY SNOWFALL BACK INTO THE LAKE AND CHAFFEE COUNTY AREAS...AS
PER LATEST SATELLITE IMAGERY AND SPOTTER REPORTS.
THEREFORE...UPGRADED EXISTING SNOW ADVISORIES FOR LOWER PORTIONS
OF LAKE AND CHAFFEE COUNTIES TO A WINTER STORM WARNING...IN EFFECT
UNTIL 12Z TOMORROW MORNING. MOORE
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM MDT FRI APR 17 2015
THERE ARE SEVERAL CONCERNS FOR THE SHORT TERM FORECAST...INCLUDING
THE POTENTIAL FOR CRITICAL FIRE WX CONDITIONS...THE POTENTIAL FOR
SEVERE STORMS AND SNOW AMOUNTS.
STILL SEE OCNL LIGHTNING STRIKES OVR SERN CO THIS MORNING.
SATELLITE IMAGES SHOW THE UPR LOW CENTERED OVR NWRN NM THIS
MORNING...AND IT IS FORECAST TO MOVE NORTHEASTWARD TODAY AND
TONIGHT. BY 12Z SAT...THE NAM...GFS AND ECMWF SHOW THE LOW CENTER
IN DIFFERENT LOCATIONS. THE GFS AND ECMWF ARE FAIRLY SIMILAR WITH
THE LOW ABOUT OVR THE PALMER DVD...THE GFS IS A LITTLE FARTHER E AND
S THAN THE ECMWF. THE NAM HAS THE LOW CENTER AT 12Z SAT OVR NRN
SAGUACHE COUNTY.
FOR THE FIRST HALF OF TODAY THE MODELS SHOW CONTINUED MOIST EASTERLY
FLOW ACRS THE PIKES PEAK REGION...FREMONT COUNTY AND LAKE AND
CHAFFEE COUNTIES...WITH SOME PCPN ALSO OVR THE SW MTNS AND SRN
PORTIONS OF THE ERN MTNS...JUST NOT AS HEAVY AS NRN AREAS. AT THE
SAME TIME...A DRY SLOT WL WORK ITS WAY INTO THE SERN PLAINS.
HOWEVER...THE NAM HAS AN AREA OF CONVECTION DEVELOPING...MAINLY N OF
HIGHWAY 50 OVR THE ERN PLAINS THIS AFTERNOON...WITH LAS ANIMAS AND
BACA COUNTIES REMAINING DRY. THE GFS AND HRRR ARE DRY THIS AFTERNOON
OVR THE FAR SERN PLAINS. STRONG SOUTHERLY WINDS OVR BACA AND LAS
ANIMAS COUNTIES...ALONG WITH RH VALUES DROPPING BELOW 15 PERCENT ARE
EXPECTED THIS AFTERNOON SO WL ISSUE A RED FLAG WARNING FOR THESE
LOCATIONS. PORTIONS OF SRN PROWERS AND BENT COUNTIES MAY ALSO REACH
RED FLAG CRITERIA...BUT UNCERTAINTY ABOUT PCPN OVR THESE COUNTIES WL
KEEP ME FROM ISSUING A FIRE HIGHLIGHT AT THIS TIME. THE NAM
DECREASES PCPN OVR MANY OF THE MTN AREAS THIS AFTERNOON...WHILE IT
STILL LOOKS GOOD ON THE GFS OVR THE NRN MTNS PORTIONS OF THE CWA.
THE ECMWF DECREASES PCPN OVR THE PIKES PEAK REGION BUT KEEPS GOOD
PCPN GOING OVR LAKE AND CHAFFEE COUNTIES.
THE GFS IS MUCH DRIER AT THE SFC THIS AFTERNOON OVR THE FAR SERN
PLAINS THAN THE NAM...WHICH MAKES A DIFFERENCE IN THE POTENTIAL FOR
SEVERE WX. WL LEAN THE FORECAST A LITTLE MORE TOWARD THE NAM OVR
PROWERS...BENT...AND KIOWA COUNTIES. IF THE NAM IS CORRECT...CAPE
VALUES COULD RANGE FROM ABOUT 600-1500 J/KG OVR PROWERS...NRN BENT
AND KIOWA COUNTIES...WITH 0-6KM SHEAR VALUES OF 50-60 KTS...AND WE
COULD SEE A COUPLE SEVERE STORMS. THE HRRR ALSO SETS UP A DRYLINE
MAINLY NORTH OF HIGHWAY 50S THIS AFTERNOON OVR THE FAR SERN PLAINS.
HOWEVER...IF THE DRIER GFS IS CORRECT THE BETTER MSTR AND SVR
CHANCES WL BE EAST OF THE AREA.
TONIGHT AS THE UPR LOW CONTINUES TO LIFT NORTHEASTWARD...MUCH OF THE
SERN PLAINS LOOK TO BE DRY...WITH MANY OF THE MTN AREAS STILL SEEING
SOME PCPN. ALTHOUGH THE DIFFERING POSITIONS OF THE UPR LOW CENTER
RESULT IN DIFFERENCES IN WHAT MTNS AREAS WL HAVE THE BEST PCPN
CHANCES. WILL NOT MAKE ANY CHANGES TO THE WINTER WEATHER HIGHLIGHTS
THIS MORNING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 410 AM MDT FRI APR 17 2015
SATURDAY-SUNDAY...LATEST MODELS REMAIN IN DECENT AGREEMENT OF STRONG
UPPER LOW ACROSS SOUTH CENTRAL COLORADO EARLY SATURDAY SLOWLY
LIFTING NORTH AND EAST THROUGH SATURDAY NIGHT WITH THE SYSTEM THEN
WEAKENING AND MERGING WITH A BROAD UPPER TROUGH TRANSLATING ACROSS
THE NORTHERN TIER OF STATES. BEST CHANCES OF PRECIPITATION EARLY
SATURDAY REMAINS ACROSS THE CONTDVD THROUGH THE SOUTHERN MTS WITH
DEVELOPING WRAPAROUND PRECIPITATION SHIELD AND DEVELOPING NORTHWEST
FLOW BEHIND THE PASSING SYSTEM. SHOULD SEE ISOLATED TO SCATTERED
SHOWERS AND A FEW EMBEDDED THUNDERSTORMS ACROSS THE EASTERN PLAINS
SATURDAY AFTERNOON AND EVENING WITH COLD CORE UPPER LOW TRANSLATING
INTO NORTHEASTERN COLORADO. MAY NEED TO EXTEND OR ADD WINTER
HIGHLIGHTS ACROSS THE CENTRAL MTS INTO SATURDAY WITH SEVERAL INCHES
OF SNOW EXPECTED...ESPECIALLY AOA 10KT FEET. MID LEVEL TEMPS SLOWLY
WARM SATURDAY AS THE SYSTEM LIFTS OUT ACROSS THE AREA AND SHOULD SEE
HIGHS SLIGHTLY WARMER AS A RESULT...THOUGH STILL BELOW SEASONAL
AVERAGES.
PASSING UPPER SYSTEM ACROSS THE AREA LATE SATURDAY SENDS A COLD
FRONT ACROSS THE EASTERN PLAINS EARLY SUNDAY MORNING...WITH GUSTY
NORTH TO NORTHWEST WINDS OF 20 TO 40 MPH EXPECTED IN ITS WAKE...WITH
THE STRONGEST WINDS EXPECTED ACROSS THE FAR EASTERN PLAINS. A MINOR
WAVE EMBEDDED WITHIN THE NORTHWEST FLOW ALOFT SUPPORTS ISOLATED TO
SCATTERED SHOWERS ACROSS THE AREA ON SUNDAY...WITH TEMPERATURES
SLIGHTLY COOLER THAN SATURDAY.
MONDAY-TUESDAY...EMBEDDED DISTURBANCES IN THE SLOWLY MODERATING
NORTHWEST FLOW ACROSS THE AREA WILL KEEP ISOLATED TO SCATTERED
MAINLY AFTERNOON AND EVENING SHOWERS IN THE FORECAST WITH
TEMPERATURES WARMING BACK TO NEAR SEASONAL AVERAGES.
WEDNESDAY-THURSDAY...A REX LIKE BLOCKING PATTERN LOOKS TO SET UP
ACROSS THE REGION WITH RIDGING ACROSS THE ROCKIES AND TROUGHS
SETTING UP OVER THE COASTS. THIS LOOKS TO KEEP UNSETTLED WEATHER
ACROSS THE AREA WITH COOL HIGH PRESSURE ACROSS THE MIDWEST KEEPING
UPSLOPE FLOW IN PLACE ACROSS EASTERN COLORADO ALONG WITH INCREASING
MOISTURE WITHIN DEVELOPING SOUTHWEST FLOW ALOFT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 410 AM MDT FRI APR 17 2015
KCOS WL MAINLY HAVE MVFR CONDITIONS THIS MORNING WITH THE POTENTIAL
FOR SNOW SHOWERS OR A MIX OF RAIN AND SNOW. THIS AFTERNOON FORECAST
SOUNDINGS SHOW A RETURN TO VFR CONDITIONS THROUGH EARLY
EVENING...AND THEN THE POTENTIAL FOR MVFR CONDITIONS DEVELOPING
AGAIN.
KPUB SHOULD GENERALLY HAVE MVFR CONDITIONS WITH THE POTENTIAL FOR
RAIN SHOWERS AND MAYBE EVEN A THUNDERSTORM. FORECAST SOUNDINGS SHOW
A RETURN TO VFR CONDITIONS IN THE LATE MORNING HOURS AND THROUGH THE
REST OF THE PERIOD.
KALS SHOULD GENERALLY SEE VFR CONDITIONS UNTIL LATE TONIGHT...WHEN
THERE WILL BE THE POTENTIAL FOR MVFR OR IFR CONDITIONS. BREEZY
SOUTHWEST WINDS ARE EXPECTED THIS AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 AM MDT SATURDAY FOR COZ058>063-072-
073-080-082.
WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR
COZ077>079-084.
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ233-237.
WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT FOR COZ076-081.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT SATURDAY FOR COZ074-075.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ066.
&&
$$
UPDATE...MOORE
SHORT TERM...28
LONG TERM...MW
AVIATION...28
AREA FORECAST DISCUSSION
NWS PUEBLO CO
410 AM MDT FRI APR 17 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM MDT FRI APR 17 2015
THERE ARE SEVERAL CONCERNS FOR THE SHORT TERM FORECAST...INCLUDING
THE POTENTIAL FOR CRITICAL FIRE WX CONDITIONS...THE POTENTIAL FOR
SEVERE STORMS AND SNOW AMOUNTS.
STILL SEE OCNL LIGHTNING STRIKES OVR SERN CO THIS MORNING.
SATELLITE IMAGES SHOW THE UPR LOW CENTERED OVR NWRN NM THIS
MORNING...AND IT IS FORECAST TO MOVE NORTHEASTWARD TODAY AND
TONIGHT. BY 12Z SAT...THE NAM...GFS AND ECMWF SHOW THE LOW CENTER
IN DIFFERENT LOCATIONS. THE GFS AND ECMWF ARE FAIRLY SIMILAR WITH
THE LOW ABOUT OVR THE PALMER DVD...THE GFS IS A LITTLE FARTHER E AND
S THAN THE ECMWF. THE NAM HAS THE LOW CENTER AT 12Z SAT OVR NRN
SAGUACHE COUNTY.
FOR THE FIRST HALF OF TODAY THE MODELS SHOW CONTINUED MOIST EASTERLY
FLOW ACRS THE PIKES PEAK REGION...FREMONT COUNTY AND LAKE AND
CHAFFEE COUNTIES...WITH SOME PCPN ALSO OVR THE SW MTNS AND SRN
PORTIONS OF THE ERN MTNS...JUST NOT AS HEAVY AS NRN AREAS. AT THE
SAME TIME...A DRY SLOT WL WORK ITS WAY INTO THE SERN PLAINS.
HOWEVER...THE NAM HAS AN AREA OF CONVECTION DEVELOPING...MAINLY N OF
HIGHWAY 50 OVR THE ERN PLAINS THIS AFTERNOON...WITH LAS ANIMAS AND
BACA COUNTIES REMAINING DRY. THE GFS AND HRRR ARE DRY THIS AFTERNOON
OVR THE FAR SERN PLAINS. STRONG SOUTHERLY WINDS OVR BACA AND LAS
ANIMAS COUNTIES...ALONG WITH RH VALUES DROPPING BELOW 15 PERCENT ARE
EXPECTED THIS AFTERNOON SO WL ISSUE A RED FLAG WARNING FOR THESE
LOCATIONS. PORTIONS OF SRN PROWERS AND BENT COUNTIES MAY ALSO REACH
RED FLAG CRITERIA...BUT UNCERTAINTY ABOUT PCPN OVR THESE COUNTIES WL
KEEP ME FROM ISSUING A FIRE HIGHLIGHT AT THIS TIME. THE NAM
DECREASES PCPN OVR MANY OF THE MTN AREAS THIS AFTERNOON...WHILE IT
STILL LOOKS GOOD ON THE GFS OVR THE NRN MTNS PORTIONS OF THE CWA.
THE ECMWF DECREASES PCPN OVR THE PIKES PEAK REGION BUT KEEPS GOOD
PCPN GOING OVR LAKE AND CHAFFEE COUNTIES.
THE GFS IS MUCH DRIER AT THE SFC THIS AFTERNOON OVR THE FAR SERN
PLAINS THAN THE NAM...WHICH MAKES A DIFFERENCE IN THE POTENTIAL FOR
SEVERE WX. WL LEAN THE FORECAST A LITTLE MORE TOWARD THE NAM OVR
PROWERS...BENT...AND KIOWA COUNTIES. IF THE NAM IS CORRECT...CAPE
VALUES COULD RANGE FROM ABOUT 600-1500 J/KG OVR PROWERS...NRN BENT
AND KIOWA COUNTIES...WITH 0-6KM SHEAR VALUES OF 50-60 KTS...AND WE
COULD SEE A COUPLE SEVERE STORMS. THE HRRR ALSO SETS UP A DRYLINE
MAINLY NORTH OF HIGHWAY 50S THIS AFTERNOON OVR THE FAR SERN PLAINS.
HOWEVER...IF THE DRIER GFS IS CORRECT THE BETTER MSTR AND SVR
CHANCES WL BE EAST OF THE AREA.
TONIGHT AS THE UPR LOW CONTINUES TO LIFT NORTHEASTWARD...MUCH OF THE
SERN PLAINS LOOK TO BE DRY...WITH MANY OF THE MTN AREAS STILL SEEING
SOME PCPN. ALTHOUGH THE DIFFERING POSITIONS OF THE UPR LOW CENTER
RESULT IN DIFFERENCES IN WHAT MTNS AREAS WL HAVE THE BEST PCPN
CHANCES. WILL NOT MAKE ANY CHANGES TO THE WINTER WEATHER HIGHLIGHTS
THIS MORNING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 410 AM MDT FRI APR 17 2015
SATURDAY-SUNDAY...LATEST MODELS REMAIN IN DECENT AGREEMENT OF STRONG
UPPER LOW ACROSS SOUTH CENTRAL COLORADO EARLY SATURDAY SLOWLY
LIFTING NORTH AND EAST THROUGH SATURDAY NIGHT WITH THE SYSTEM THEN
WEAKENING AND MERGING WITH A BROAD UPPER TROUGH TRANSLATING ACROSS
THE NORTHERN TIER OF STATES. BEST CHANCES OF PRECIPITATION EARLY
SATURDAY REMAINS ACROSS THE CONTDVD THROUGH THE SOUTHERN MTS WITH
DEVELOPING WRAPAROUND PRECIPITATION SHIELD AND DEVELOPING NORTHWEST
FLOW BEHIND THE PASSING SYSTEM. SHOULD SEE ISOLATED TO SCATTERED
SHOWERS AND A FEW EMBEDDED THUNDERSTORMS ACROSS THE EASTERN PLAINS
SATURDAY AFTERNOON AND EVENING WITH COLD CORE UPPER LOW TRANSLATING
INTO NORTHEASTERN COLORADO. MAY NEED TO EXTEND OR ADD WINTER
HIGHLIGHTS ACROSS THE CENTRAL MTS INTO SATURDAY WITH SEVERAL INCHES
OF SNOW EXPECTED...ESPECIALLY AOA 10KT FEET. MID LEVEL TEMPS SLOWLY
WARM SATURDAY AS THE SYSTEM LIFTS OUT ACROSS THE AREA AND SHOULD SEE
HIGHS SLIGHTLY WARMER AS A RESULT...THOUGH STILL BELOW SEASONAL
AVERAGES.
PASSING UPPER SYSTEM ACROSS THE AREA LATE SATURDAY SENDS A COLD
FRONT ACROSS THE EASTERN PLAINS EARLY SUNDAY MORNING...WITH GUSTY
NORTH TO NORTHWEST WINDS OF 20 TO 40 MPH EXPECTED IN ITS WAKE...WITH
THE STRONGEST WINDS EXPECTED ACROSS THE FAR EASTERN PLAINS. A MINOR
WAVE EMBEDDED WITHIN THE NORTHWEST FLOW ALOFT SUPPORTS ISOLATED TO
SCATTERED SHOWERS ACROSS THE AREA ON SUNDAY...WITH TEMPERATURES
SLIGHTLY COOLER THAN SATURDAY.
MONDAY-TUESDAY...EMBEDDED DISTURBANCES IN THE SLOWLY MODERATING
NORTHWEST FLOW ACROSS THE AREA WILL KEEP ISOLATED TO SCATTERED
MAINLY AFTERNOON AND EVENING SHOWERS IN THE FORECAST WITH
TEMPERATURES WARMING BACK TO NEAR SEASONAL AVERAGES.
WEDNESDAY-THURSDAY...A REX LIKE BLOCKING PATTERN LOOKS TO SET UP
ACROSS THE REGION WITH RIDGING ACROSS THE ROCKIES AND TROUGHS
SETTING UP OVER THE COASTS. THIS LOOKS TO KEEP UNSETTLED WEATHER
ACROSS THE AREA WITH COOL HIGH PRESSURE ACROSS THE MIDWEST KEEPING
UPSLOPE FLOW IN PLACE ACROSS EASTERN COLORADO ALONG WITH INCREASING
MOISTURE WITHIN DEVELOPING SOUTHWEST FLOW ALOFT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 410 AM MDT FRI APR 17 2015
KCOS WL MAINLY HAVE MVFR CONDITIONS THIS MORNING WITH THE POTENTIAL
FOR SNOW SHOWERS OR A MIX OF RAIN AND SNOW. THIS AFTERNOON FORECAST
SOUNDINGS SHOW A RETURN TO VFR CONDITIONS THROUGH EARLY
EVENING...AND THEN THE POTENTIAL FOR MVFR CONDITIONS DEVELOPING
AGAIN.
KPUB SHOULD GENERALLY HAVE MVFR CONDITIONS WITH THE POTENTIAL FOR
RAIN SHOWERS AND MAYBE EVEN A THUNDERSTORM. FORECAST SOUNDINGS SHOW
A RETURN TO VFR CONDITIONS IN THE LATE MORNING HOURS AND THROUGH THE
REST OF THE PERIOD.
KALS SHOULD GENERALLY SEE VFR CONDITIONS UNTIL LATE TONIGHT...WHEN
THERE WILL BE THE POTENTIAL FOR MVFR OR IFR CONDITIONS. BREEZY
SOUTHWEST WINDS ARE EXPECTED THIS AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM MDT SATURDAY FOR COZ059-062-
063-074-075.
WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR
COZ077>079-084.
RED FLAG WARNING FROM NOON TODAY TO 8 PM MDT THIS EVENING FOR
COZ233-237.
WINTER STORM WARNING UNTIL 6 AM MDT SATURDAY FOR COZ058-060-061-
072-073-080-082.
WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT FOR COZ076-081.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ066.
&&
$$
SHORT TERM...28
LONG TERM...MW
AVIATION...28
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1141 PM MDT THU APR 16 2015
.UPDATE...
ISSUED AT 930 PM MDT THU APR 16 2015
UPDATED TO MAKE SOME MINOR ADJUSTMENTS TO POPS THROUGH TOMORROW
BASED ON RADAR TRENDS AND 00Z GUIDANCE. LOOKS LIKE THE SVR THREAT
IS OVER FOR NOW...BUT COULD STILL SEE SOME ISOLD TS OVER THE
SE PLAINS TONIGHT. STILL EXPECTING SOME DRY AIR TO PUSH INTO SE
CO TOMORROW...BUT THERE WILL BE SCT SHOWERS AROUND IN THE MORNING.
MAIN AREA TO WATCH THROUGH TOMORROW WILL BE THE UPPER ARKANSAS AND
GUNNISON VALLEY...WHERE SOME GUIDANCE IS SHOWING A PERSISTENT SNOW
BAND DEVELOPING. ROSE
UPDATE ISSUED AT 543 PM MDT THU APR 16 2015
UPDATED THE FORECAST TO INCLUDE TELLER COUNTY AND NORTHERN FREMONT
COUNTY IN A WINTER STORM WARNING. MULTIPLE BANDS OF PRECIP
EXPECTED TO ROTATE IN FROM THE SE TONIGHT...WITH VARIOUS MODELS
SHOWING .7 TO 1.4 INCHES OF QPF. WITH COOLING TEMPS AFTER SUNSET
EXPECT ROADS TO ICE OVER...LEADING TO HAZARDOUS TRAVEL IN THE
WARNED AREAS. ROSE
UPDATE ISSUED AT 423 PM MDT THU APR 16 2015
UPDATED THE FORECAST TO CANCEL THE RED FLAG FOR THE SAN LUIS
VALLEY. SCATTERED SHOWERS ARE OVER THE VALLEY AND HUMIDITY IS
NO LONGER CRITICAL. ROSE
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 356 PM MDT THU APR 16 2015
...MODERATE TO HEAVY SNOW POSSIBLE FOR THE MOUNTAINS TONIGHT AND
FRIDAY...
...CRITICAL FIRE WEATHER CONDITIONS POSSIBLE FOR THE FAR SOUTHEAST
PLAINS AGAIN ON FRIDAY THOUGH THIS IS DEPENDENT ON HOW MUCH RAIN
FALLS OVER THESE AREAS TONIGHT...
...MARGINAL POTENTIAL FOR SEVERE POSSIBLE FOR NORTHERN EL PASO AND
KIOWA COUNTIES ON FRIDAY...
STILL A HIGHLY DYNAMIC FORECAST AS MODELS HONE IN ON TRACK AND
STRENGTH OF THE CLOSED LOW CURRENTLY ACROSS THE 4 CORNERS REGION.
MODELS BOBBLE THE UPPER LOW SOUTHWARD A BIT THIS EVENING...THEN BACK
TO THE NORTHEAST ACROSS THE CO/NM BORDER TONIGHT AS ENERGY ROTATES
AROUND THE BASE OF THE UPPER LOW AND ACROSS CO. THEN IT MAKES
STEADIER PROGRESS TO THE NORTHEAST INTO EAST CENTRAL CO ON FRIDAY.
ALREADY SEEING ENHANCEMENT ACROSS THE SOUTHEAST MTS AND NRN NM AS
THE NEXT IMPULSE APPROACHES. HRRR SEEMS TO HAVE PICKED UP ON THIS
TREND FAIRLY WELL. WE SHOULD CONTINUE TO SEE SHOWERS FILL IN ACROSS
THE SOUTHEAST MOUNTAINS...AND I-25 CORRIDOR...WITH SNOW LEVELS
AROUND 6000-6500 FEET. SNOW LEVELS MAY ACTUALLY RISE A BIT FOR THE
LOWER EASTERN SLOPES AS STRONG WAA OCCURS OVERNIGHT...WHICH COULD
CAUSE A SWITCH BACK TO RAIN AT KCOS OVERNIGHT. HOWEVER...MTN AREAS
SHOULD CONTINUE TO SEE SNOW AND HAVE EXPANDED ADVISORIES ACROSS MUCH
OF THE MOUNTAIN AREAS. GIVEN THE CONVECTIVE POTENTIAL WITH THIS
EVENINGS ROUND...CONCERNED THAT PORTIONS OF TELLER COUNTY COULD HIT
WARNING CRITERIA...THOUGH DON`T THINK IT WILL BE WIDESPREAD ENOUGH
ACROSS THE ZONE TO WARRANT AN UPGRADE. CENTRAL LAKE COUNTY COULD BE
IN A SIMILAR BOAT...SO THESE AREAS WILL BE THE ONES TO WATCH
CLOSELY. MEANWHILE...MODELS SHOW DEFORMATION BAND SNOW SPREADING
WESTWARD INTO THE SOUTHWEST MOUNTAINS TONIGHT AND CONTINUING THROUGH
FRIDAY. HAVE OPTED TO EXPAND ADVISORIES INTO THE LA GARITAS WHERE
SNOW AMOUNTS ARE APPROACHING THE 6-12 INCH RANGE. STILL SOME
QUESTION OVER THE EASTERN SAN JUANS THOUGH...COULD SEE A COUPLE
INCHES FALL THERE TONIGHT...WITH ANOTHER 1-3 INCHES FALLING ON
FRIDAY AS THE UPPER LOW WRAPS DEFORMATION BAND BACK TO THE SOUTHWEST
ACROSS THE REGION. CONTEMPLATED AN ADVISORY FOR THIS REGION...BUT
AM COMING UP SHY OF THE 6-12 INCHES NEEDED FOR A WINTER WX
ADVISORY...THOUGH CERTAINLY SUBTLE CHANGES IN THE TRACK AND STRENGTH
OF THE LOW COULD RESULT IN HEAVIER AMOUNTS FOR THIS REGION.
STICKING TRUE TO THE GRIDS FOR NOW AND WILL LET LATER SHIFTS
REASSESS.
AS FOR SEVERE THUNDERSTORM POTENTIAL ACROSS THE PLAINS...APPEARS
TIMING OF THE INITIAL WAVE THIS AFTERNOON WAS TOO QUICK FOR THE LOW
LEVEL MOISTURE RETURN...AND NICE LINE OF THUNDERSTORMS HAS ALREADY
DEVELOPED AND PUSHED EASTWARD INTO KANSAS. HOWEVER AS SURFACE WINDS
HAVE VEERED MORE EASTERLY DUE TO FALLING SFC PRESSURES ACROSS NEW
MEXICO...40S AND LOWER 50 DEW POINTS HAVE PULLED WESTWARD INTO THE
FAR SOUTHEAST PLAINS. ACTIVITY INCREASING ACROSS NORTHERN NEW
MEXICO MAY STILL HAVE A CHANCE TO INTERACT WITH THIS MOISTURE TO
PRODUCE SOME ISOLATED SEVERE THUNDERSTORMS...WITH HAIL AND GUSTY
WINDS THE PRIMARY STORM THREATS. OVERNIGHT...LATEST HRRR HINTS AT
ANOTHER ROUND CLIPPING BY BACA COUNTY DURING THE 8Z TO 09Z
TIMEFRAME...AND EVEN SOME SPOTTY THUNDERSTORMS POSSIBLE AS FAR WEST
AS THE I-25 CORRIDOR. SO THOUGH MAIN THREAT FOR SEVERE
THUNDERSTORMS WILL BE THIS EVENING...CAN`T RULE OUT A LOW GRADE
SEVERE THREAT ACROSS THE FAR SOUTHEAST PLAINS EVEN DURING THE
OVERNIGHT HOURS...THOUGH THUNDERSTORMS WILL TEND TO BE MORE
ELEVATED. TOMORROW AS THE SURFACE LOW LIFTS INTO SOUTHEAST
CO...COULD SEE SOME ISOLATED THUNDERSTORMS EVEN IN THE MORNING...AND
LAPSE RATES WILL BE STEEP GIVEN THE MID LEVEL COOLING ASSOCIATED
WITH THE SURFACE LOW. NAM12 SHOWS UP TO 1000 J/KG OF CAPE ACROSS
NORTHERN PORTIONS OF THE SE PLAINS DURING THE MORNING...SO COULD
HAVE ANOTHER CHANCE FOR SEVERE THUNDERSTORMS ON FRIDAY. BY
AFTERNOON...DRY AIR SPREADS INTO THE SOUTHEAST PLAINS AS SURFACE LOW
LIFTS NORTHWARD. THIS PUTS THE AXIS OF BEST INSTABILITY ALONG THE
NORTHERN FRINGES OF THE SOUTHEAST PLAINS BY AFTERNOON...PRIMARILY
NORTHEAST EL PASO AND KIOWA COUNTIES. THESE AREAS ARE OUTLOOKED FOR
A MARGINAL SEVERE THREAT TOMORROW...AND THIS LOOKS ON TARGET. COULD
SEE THIS MARGINAL THREAT SLIPPING SOUTHWARD A BIT TO ACCOUNT FOR ANY
STRONG MORNING CONVECTION. BUT AS DRY AIR EXPANDS NORTHWARD...SO
DOES THE POTENTIAL FOR CRITICAL FIRE WEATHER PARAMETERS...ESPECIALLY
ACROSS LAS ANIMAS...BACA...BENT...PROWERS... AND OTERO COUNTIES.
THE MITIGATING FACTOR WILL BE THE POTENTIAL FOR RAINFALL TO WET
FUELS TONIGHT OVER THESE SAME ZONES. GIVEN THIS POTENTIAL...HAVE
NOT GONE OUT WITH A FIRE WEATHER WATCH...BUT IF PRECIPITATION
DOESN`T MATERIALIZE ACROSS A WIDESPREAD ENOUGH AREA ACROSS THESE
REGION...THEN LATER SHIFTS MAY NEED TO HOIST A RED FLAG WARNING. -KT
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 356 PM MDT THU APR 16 2015
FRIDAY NIGHT THROUGH SATURDAY...MODELS HAVE SHIFTED A BIT OVER THE
PST 24 HRS...BUT STILL REMAIN FAIRLY CONSISTENT WITH THE PLACEMENT
AND PATH OF THE UPPER LOW. FRIDAY NIGHT THE LOW PRESSURE SYSTEM IS
FORECAST TO BE CENTERED RIGHT OVER COLORADO...THEN OVER THE NEXT 24
HRS IT WILL WOBBLE A BIT BEFORE SLOWLY EXITING THE STATE VIA THE
EASTERN BORDER. THIS PATTERN WOULD IMPLY THAT THE MTS...ESPECIALLY
THE CONTDVD...WILL GET THE BRUNT OF SNOWFALL...MAINLY THROUGH FRIDAY
NIGHT. THEREFORE...ONGOING WINTER HIGHLIGHTS RUNNING THROUGH 12Z
SATURDAY LOOK REASONABLE. SNOW AMOUNTS WILL THEN TAPER OVER OVER THE
DAY SATURDAY AS TEMPS BEGIN TO WARM AND THE SYSTEM WEAKENS. ISOLATED
TO SCATTERED SHOWERS ARE FORECAST FOR THE REMAINDER OF THE LOWER
ELEVATIONS...AND TEMPS DO NOT LOOK PARTICULARLY COLD WITH MIN TEMPS
IN THE 30S TO AROUND 40 F FOR THE PLAINS...AND MAX TEMPS SATURDAY IN
THE MID 50S TO LOWER 60S.
SUNDAY AND MONDAY...THE UPPER SYSTEM WEAKENS AND EXITS TO THE EAST
LATE SATURDAY...WITH BRISK NW FLOW ALOFT THEN SETTLING IN ACROSS THE
STATE. A COUPLE OF UPPER SHORTWAVES ARE EXPECTED TO DROP DOWN ACROSS
THE STATE ON BOTH DAYS...KEEPING THE THREAT OF SHOWER ACTIVITY FOR
THE CWA IN PLACE. LOOK FOR SCATTERED SHOWERS OVER THE HIGHER
TERRAIN...AND ISOLATED SHOWERS FOR THE PLAINS...WITH MAX TEMPS BOTH
DAYS HOVERING IN THE 50S TO NEAR 60 F.
TUESDAY THROUGH THURSDAY...CONFIDENCE IS FAIRLY LOW FOR WHAT HAPPENS
BEYOND MONDAY...THOUGH LONG RANGE MODELS SEEM TO AGREE ON THE
QUESTION MARK. A TEMPORARY RIDGE BUILDS INTO THE DESERT SW STARTING
TUE...HELPING TO LOWERING PCPN CHANCES AS WELL AS BOOSTING MAX TEMPS
FOR THE PLAINS BACK INTO THE 70S. TWO SEPARATE UPPER CLOSED LOW
SYSTEMS APPROACH STARTING WED NIGHT...ONE OVER THE PAC NW AND THE
OTHER OVER S CA...BUT THIS PATTERN WILL MOST LIKELY GO THROUGH
MULTIPLE ADJUSTMENTS BEFORE THEN. MOORE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1128 PM MDT THU APR 16 2015
LARGE UPPER LOW SPINNING NEAR THE 4 CORNERS REGION WILL PRODUCE
WIDESPREAD MVFR/IFR AND LOCAL LIFR CONDITIONS ACROSS THE FLIGHT
AREA THROUGH THROUGH TONIGHT AND UP THROUGH ABOUT 18Z FRIDAY.
AFTER 18Z...IT LOOKS LIKE THE FOCUS FOR THESE CONDITIONS WILL
SHIFT MAINLY TO THE WESTERN MOUNTAINS...WITH CONDITIONS ELSEWHERE
IMPROVING TO VFR...WITH JUST ISOLATED TO SCATTERED MVFR/IFR. THE
KCOS...KPUB AND KALS TAF SITES SHOULD ALL FOLLOW THIS TREND...WITH
IMPROVEMENT EXPECTED AFTER 18Z FRIDAY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM MDT SATURDAY FOR COZ059-062-
063-074-075.
WINTER WEATHER ADVISORY UNTIL 6 PM MDT FRIDAY FOR COZ077>079-084.
WINTER STORM WARNING UNTIL 6 AM MDT SATURDAY FOR COZ058-060-061-
072-073-080-082.
WINTER STORM WARNING UNTIL MIDNIGHT MDT FRIDAY NIGHT FOR COZ076-
081.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT FRIDAY NIGHT FOR
COZ066.
&&
$$
UPDATE...ROSE
SHORT TERM...KT
LONG TERM...MOORE
AVIATION...LW
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
445 AM EDT FRI APR 17 2015
.SYNOPSIS... 08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN UPPER
LEVEL PATTERN THAT HAS CHANGED LITTLE OVER THE PAST 24 HOURS.
NORTHERN STREAM WESTERLIES REMAIN MOSTLY ZONAL TO THE NORTH OF THE
CANADIAN BORDER...WHILE MOIST SOUTHERN STREAM WESTERLIES CROSS OVER
NORTHERN MEXICO FROM THE CENTRAL PACIFIC...AND THEN MOVE ALONG THE
NORTHERN GULF COAST/SOUTHEAST CONUS. BETWEEN THESE TWO BELTS OF
WESTERLIES...A LARGE CUTOFF LOW CENTERED OVER THE FOUR CORNERS
REGION CONTINUES TO SPIN AND EJECT PIECES OF ENERGY OUT INTO THE
SOUTHERN/CENTRAL PLAINS. A SERIES OF UPPER LEVEL IMPULSE ARE ALSO
RIDING THE SOUTHERN STREAM FLOW AND FORCING PERIODIC FLARES OF
CONVECTION OVER THE NORTH-CENTRAL GULF. THESE CONVECTIVE BURST WILL
MAKE OUR LOCAL FORECAST A BIT TRICKY INTO SATURDAY AS WILL BE
EXPLAINED IN THE SHORT TERM DISCUSSION BELOW.
AT THE SURFACE...A COMPLEX PRESSURE PATTERN EXISTS JUST TO OUR NORTH
AND NORTHEAST WITH A WEDGE HIGH IN PLACE ACROSS THE SOUTHEAST CONUS
AND AN AREA OF LOW PRESSURE ANALYZED JUST OFF THE GA/SC COAST. THE
FLOW AROUND THESE FEATURES HAS KEPT A WEAK FRONTAL BOUNDARY IN PLACE
ACROSS NORTH-CENTRAL FLORIDA...BISECTING OUR FORECAST AREA FROM EAST
TO WEST. THERE ARE AREAS OF LOWER CLOUDS EARLY THIS MORNING ALONG
AND TO THE NORTH OF THIS BOUNDARY THAT WILL BE OF SOME CONCERN TO
THE AVIATION COMMUNITY...ALTHOUGH THESE CIGS SHOULD LIFT
QUICKLY...WITHIN A FEW HOURS OF SUNRISE.
REGIONAL RADARS SHOW THAT THE LAST OF THE THURSDAY RESIDUAL SHOWER
ACTIVITY ASSOCIATED WITH THE WEAK FRONT AND SEA BREEZES HAS
DISSIPATED...LEAVING MOST OF THE FL PENINSULA DRY. HOWEVER...OFF TO
THE NORTHWEST ACROSS THE NE GULF AND FL PANHANDLE WE SEE A
BLOSSOMING AREA OF RAIN/EMBEDDED STORMS EXPANDING EASTWARD TOWARD
THE NORTHERN NATURE COAST ZONES. THIS AREA OF RAIN LOOKS
INCREASINGLY LIKELY TO IMPACT OUR NORTHERN NATURE COAST ZONES THIS
MORNING.
&&
.SHORT TERM (TODAY THROUGH SATURDAY)... TODAY...FIRST THINGS FIRST.
THE FORECAST CONCERN FOR THE MORNING HOURS IS THE LARGE AREA OF RAIN
OVER THE FL PANHANDLE/NORTHEAST GULF OF MEXICO. THIS CONVECTION CAN
BE ATTRIBUTED TO THE SYNOPTIC LIFT ASSOCIATED WITH A SUBTLE
SHORTWAVE PASSING OVER THE NORTH-CENTRAL GULF COAST...AND THE LOWER
LEVEL RESPONSE OF A STRENGTHENING JET RESULTING IN A BROAD WAA/LIFT
REGIME. THE MOST EFFICIENT LIFT WITH THE SHORTWAVE LOOKS TO PASS OFF
TO OUR NORTH...HOWEVER...IT IS BECOMING MORE AND MORE EVIDENT THAT
AT LEAST SOME OF THIS ACTIVITY WILL REACH OUR NORTHERN NATURE COAST
ZONES...MAINLY LEVY/CITRUS/NORTHERN SUMTER. THE RAP AND HRRR FOR
SEVERAL RUNS NOW HAVE BEEN AGGRESSIVE IN BRINGING THIS MOISTURE
EASTWARD INTO THESE AREA AFTER 11-12Z. IT IS HARD TO ARGUE WITH THIS
SOLUTION GIVEN THE CURRENT RADAR TRENDS. HAVE BUMPED UP RAIN CHANCES
TO LIKELY OVER OUR FAR NORTHERN ZONES THIS MORNING TO ACCOUNT FOR
THIS.
NOW...THE ARRIVAL OF THIS RAINFALL...WHICH IS NOT HANDLED WELL BY
MANY OF THE 00Z GUIDANCE MEMBERS...MAKES THE FORECAST TRICKY FOR THE
AFTERNOON HOURS FURTHER SOUTH INTO THE I-4 CORRIDOR AND PERHAPS
FURTHER SOUTH. THERE ARE TWO POSSIBILITIES. ONE IS THAT THE SHOWER
ACTIVITY SLOWS THE DIURNAL HEATING ACROSS THE NATURE COAST AND
ACTUALLY ENDS UP FORCING WEAK FRONTOGENESIS ALONG THE BOUNDARY DUE
TO DIFFERENTIAL DIURNAL HEATING. IN THIS CASE THE SHOWERS/STORMS
ACTIVITY INTO THE CENTRAL FORECAST AREA COULD BE ENHANCED (EVEN BACK
TOWARD THE COAST). THE LATEST 07Z HRRR SOLUTION IS SHOWING SOMETHING
SIMILAR TO THIS. THE SECOND POSSIBILITY IS THAT THE RAINFALL COOLING
AND MOMENTUM ARE ENOUGH TO PUSH AN OUTFLOW BOUNDARY SOUTH THROUGH
THE CENTRAL PENINSULA AND ACT TO INHIBIT ADDITIONAL CONVECTIVE
DEVELOPMENT THIS AFTERNOON IN ITS WAKE. METEOROLOGY IS NEVER AN
EXACT SCIENCE...AND THIS IS A TRICKY FORECAST TO SAY THE LEAST. IT
IS LIKELY BEST IN THIS SCENARIO NOT TO GET TOO HUNG UP ON
DETAILS...SINCE THIS JUST IS NOT A PATTERN WHERE THAT IS REALISTIC.
SO...WILL GO WITH LIKELY RAIN CHANCES FAR NORTH THIS MORNING...WITH
THE ENERGY AND HIGHEST RAIN CHANCES THEN PASSING OUT OF THESE AREA
FOR THE AFTERNOON. FURTHER SOUTH...WILL EXPECT SOME ENHANCEMENT
ALONG THE BOUNDARY FROM THE NORTH AND SOME SEA-BREEZE INTERACTION
FURTHER SOUTH. IT APPEARS AS THROUGH THE SOUTHERN HALF OF THE AREA
WILL HAVE THE BEST CHANCES AT A DEFINED SEA-BREEZE LATER TODAY. SO
SOUTH OF THE I-4 CORRIDOR...THE BEST RAIN CHANCES WILL BE LATE
AFTERNOON AND EVENING HOURS...AND GENERALLY INLAND AWAY FROM THE
COAST.
TONIGHT...SITUATION REMAIN TRICKY. THE QUESTION IS DO WE BELIEVE THE
PARAMETERIZED GUIDANCE OR THE CONVECTION ALLOWING GUIDANCE? THE
PARAMETERIZED GUIDANCE WOULD SUGGEST EVENING STORMS SETTLE DOWN AND
MOST OF THE OVERNIGHT IS BENIGN IN TERMS OF SENSIBLE WEATHER. MANY
OF THE HIRES CONVECTION ALLOWING MEMBERS SHOW A ROUND OF STORMS
QUICKLY CROSSING THE NE GULF AND INTO THE NATURE COAST (EVEN AS FAR
SOUTH AS THE TAMPA BAY AREA). THESE STORMS DEVELOP ALONG THE FOCUS
OF A LARGE OUTFLOW SURGE INITIATED OFF THE LOUISIANA COAST TODAY. IT
IS SURPRISING HOW MANY MEMBERS ARE SHOWING A SIMILAR SCENARIO.
HOWEVER...SO MANY THINGS HAVE TO COME TOGETHER FOR THIS CONVECTIVE
BLOB TO EVEN EXIST...INCLUDING THE PROPER PLACEMENT AND TIMING OF
THE CONVECTION OF THE LOUISIANA COAST. TOO MANY UNCERTAINTIES
HERE...AND HIRES GUIDANCE IS OFTEN OVER AGGRESSIVE IN THESE TYPE OF
CASES. WILL ALLOW FOR LOW END POPS OVER THE NATURE COAST
TONIGHT...BUT LEAN MORE TOWARD THE BENIGN GFS/NAM/ECMWF SOLUTIONS
UNTIL WE SEE EVIDENCE TO GO AGAINST THESE RELIABLE SOURCES.
SATURDAY...WELCOME TO THE WEEKEND. HEIGHT FALLS OVER THE SOUTHERN
PLAINS ASSOCIATED WITH THE EASTWARD EJECTING CUTOFF LOW WILL
ACTUALLY HELP TO RIDGE UP THE UPPER FLOW OVER OUR AREA. SO WHILE
PLENTY OF SHOWER/STORM ACTIVITY WILL BE ONGOING ACROSS THE NORTH-
CENTRAL GULF...THIS ORGANIZED CONVECTION WILL NOT BE ABLE TO COME
EASTWARD JUST YET. ALSO...OUR SURFACE BOUNDARY LOOKS TO BE JUST
ABOUT GONE BY THIS TIME...WITH A VERY WEAK GRADIENT LEFT BEHIND. THE
WEAK GRADIENT MEANS OUR FLOW WILL BE DOMINATED BY THE DEVELOPING
AFTERNOON SEA-BREEZES. JUST ABOVE THE SURFACE THE PREVAILING FLOW
WILL BE FRONT THE WEST...SO THE WEST COAST SEA BREEZE SHOULD QUICKLY
TRANSLATE INLAND AFTER INITIATION. WITH THIS IN MIND...WILL KEEP THE
BEST CHANCE OF DIURNAL STORMS SATURDAY AFTERNOON/EVENING GENERALLY
WELL INLAND...WITH ONLY LOW RAIN CHANCES BACK TOWARD THE COAST. EVEN
THESE LOW POPS SHOULD END BY MID/LATE AFTERNOON IN THE WAKE OF THE
SEA BREEZE PASSAGE.
&&
.LONG TERM (SUNDAY THROUGH NEXT THURSDAY)...
THE WEEKEND FINISHES WITH AN UPPER TROUGH OVER THE NORTH AND CENTRAL
HIGH PLAINS WHILE A RIDGE REACHES FROM THE EAST GULF TO THE UPPER
GREAT LAKES. A SURFACE LOW IN THE CENTRAL PLAINS HAS A COLD FRONT THAT
ARCS DOWN THROUGH THE MISSISSIPPI VALLEY AND INTO THE GULF. HIGH
PRESSURE IN EASTERN CANADA RIDGES SOUTH TO FL...BRIDGING A WARM FRONT
LIKE BOUNDARY OVER GA AND NW FL COASTAL WATERS.
THROUGH TUE - THE UPPER TROUGH AND SURFACE LOW LIFT UP OUT OF THE
PLAINS AND ACROSS THE GREAT LAKES INTO CANADA...WITH THE COLD FRONT
PUSHING EAST AND OFF THE EASTERN SEABOARD AND SETTLING SOUTHWARD OVER
FL. THE UPPER RIDGE AND CANADIAN HIGH PRESSURE...ALONG WITH THE WARM
FRONT OFF THE SE U.S COAST...SHIFT OUT OVER THE OPEN ATLANTIC.
FOR WED AND THU - THE UPPER TROUGH SLOWS AS IT CONTINUES TO LIFT ACROSS
EASTERN CANADA WITH ZONAL FLOW SETTING UP OVER THE GULF REGION. SURFACE
HIGH PRESSURE BUILDS IN OVER THE CENTRAL AND SOUTHERN PLAINS THEN TRACKS
ACROSS THE LOWER EASTERN SEABOARD TO THE ATLANTIC. THE FRONT ACROSS FL
HAS NOW STALLED ACROSS THE SOUTHERN HALF OF THE STATE AS IT WEAKENS.
THE DEPARTING WARM FRONT AND APPROACHING COLD FRONT WILL PROVIDE AMPLE
MOISTURE...MAXIMUM PWAT VALUES ALONG THE TWO BOUNDARIES ARE IN THE 1.8 TO
2.0 RANGE...FOR SHOWERS IN THE SLIGHT CHANCE TO LIKELY CATEGORY ALONG
WITH SOME THUNDERSTORMS. THE COLD FRONT MOVING IN ALONG WITH THE UPPER
TROUGH...BEFORE IT LIFTS AWAY...WILL RESULT IN THE HIGHEST HIGHEST
COVERAGE SUN AND MON. AS THE FRONT MOVES SOUTH AND WEAKENS THROUGH
MID-WEEK THE RAIN CHANCES BEGIN TO TREND DOWN FROM NORTH TO SOUTH.
TEMPERATURES WILL RUN A FEW DEGREES ABOVE NORMAL ALTHOUGH THEY WILL
COOL SLIGHTLY THROUGH THE PERIOD...THANKS TO CLOUD COVER AND RAINFALL.
&&
.AVIATION... AREA OF IFR/MVFR CIGS EARLY THIS MORNING FROM KTPA TO
KLAL AND NORTHWARD. FURTHER SOUTH VFR CONDITIONS PREVAIL. THESE CIG
RESTRICTIONS ARE ALONG AND NORTH OF A STATIONARY FRONTAL BOUNDARY.
SO...EXPECT RESTRICTIONS TO CONTINUE FOR SEVERAL MORE HOURS AND THEN
LIFT WITHIN A FEW HOURS AFTER SUNRISE. GENERAL VFR CONDITIONS WILL
THEN PREVAIL THROUGH THE MAJORITY OF THE DAY AND EVENING HOURS. SCT
THUNDERSTORMS ARE EXPECTED BY MID AFTERNOON...BUT GENERALLY SPEAKING
THE HIGHEST COVERAGE WILL BE INLAND FROM TERMINALS. &&
.MARINE... WIND AND SEAS REMAIN LOW THROUGH SATURDAY AWAY FROM ANY
THUNDERSTORMS. A WEAK FRONTAL BOUNDARY REMAINS IN PLACE ACROSS THE
NORTHEAST GULF TODAY. WINDS WILL SHIFT ONSHORE THIS AFTERNOON TO THE
SOUTH OF THIS BOUNDARY...MAINLY SOUTH OF TARPON SPRINGS...AND THEN
RETURN TO AN EAST/SOUTHEAST DIRECTION TONIGHT. SEA BREEZE
DEVELOPMENT IS EXPECTED FOR ALL COASTAL AREAS SATURDAY AFTERNOON.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY WILL REMAIN WELL ABOVE CRITICAL LEVELS THROUGH THE
WEEKEND KEEPING RED FLAG CONDITIONS FROM BEING REACHED. SHOWERS AND
THUNDERSTORMS WILL REMAIN IN THE FORECAST TODAY FOR MAINLY THE
NATURE COAST ZONES AND INTERIOR CENTRAL AND SOUTH-CENTRAL ZONES.
SHOWERS AND THUNDERSTORMS WILL AGAIN DEVELOP ALONG THE SEA BREEZE
SATURDAY AFTERNOON...WITH THE GREATEST CHANCE OF A WETTING RAIN WELL
INLAND FROM THE COAST.
FOG POTENTIAL... AREAS OF FOG EXPECTED AFTER MIDNIGHT TONIGHT AND
AGAIN SATURDAY NIGHT. THE HIGHEST POTENTIAL FOR FOG WILL EXIST
GENERALLY ALONG AND NORTH OF THE I-4 CORRIDOR.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 85 71 85 73 / 30 30 30 10
FMY 88 71 88 72 / 10 10 30 20
GIF 87 70 86 71 / 60 50 50 50
SRQ 85 71 84 71 / 10 20 20 10
BKV 86 67 86 67 / 40 30 30 30
SPG 84 73 84 75 / 20 30 20 10
&&
.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 TALLAHASSEE FL
433 AM EDT FRI APR 17 2015
.NEAR TERM [THROUGH TODAY]...
EARLY THIS MORNING A LARGE AREA OF RAIN WAS SITUATED ALONG THE NORTH-
CENTRAL GULF COAST, WITH LIGHT TO MODERATE RAIN JUST BEGINNING TO
ENTER OUR WESTERN FORECAST AREA AT 07 UTC. THE LAST SEVERAL RUNS OF
THE HRRR APPEAR TO HAVE THE BEST HANDLE ON THE INITIAL CONDITIONS,
BUT STILL DIVERGE AFTER ABOUT 5-6 HOURS. THEREFORE, CONFIDENCE IS
MUCH HIGHER FOR THE PRE-DAWN HOURS WITH LIGHT TO MODERATE RAIN
EXPECTED TO CONTINUE TO SPREAD INTO OUR AREA; HIGHEST POPS WILL BE
IN THE FLORIDA PANHANDLE WITH HEAVIER RAIN RATES FOCUSED TOWARD THE
GULF COAST. AFTER SUNRISE THE FORECAST BECOMES MORE UNCERTAIN WITH
MODELS INDICATING A VARIETY OF SOLUTIONS. ONE GENERAL TREND APPEARS
TO BE THE PRIMARY AREA OF RAIN BEGINNING TO DISSIPATE LATER IN THE
MORNING, FOLLOWED BY REDEVELOPMENT OF RAIN (MORE CONVECTIVE THIS
TIME) IN OUR WESTERN FORECAST AREA OR JUST WEST OF OUR AREA BETWEEN
16 UTC AND 19 UTC. HOWEVER, PINPOINTING A SPECIFIC AREA WHERE RAIN
IS MORE LIKELY OR RAINFALL TOTALS MAY BE HIGHER DURING THE DAYTIME
IS TOUGHER DUE TO MODEL DIFFERENCES AND THE LACK OF A STRONG FORCING
MECHANISM. THEREFORE, WE KEPT A "LIKELY" POP IN THE FORECAST
EVERYWHERE WITH AN EMPHASIS ON STRATIFORM PRECIP IN THE MORNING
(RAIN, MORE STABLE) AND A TREND TOWARD CONVECTIVE PRECIP IN THE
AFTERNOON (SHOWERS AND STORMS, MORE UNSTABLE). HOWEVER, OUR GENERAL
FEELING IS THAT RAIN AND STORMS WILL BECOME FOCUSED CLOSER TO THE
GULF COAST WITH TIME - NEARER TO THE SURFACE FRONT. WITH VERY HIGH
PRECIPITABLE WATER FOR APRIL AND WEAK FLOW BELOW 20,000 FT, ANY LOW
TOPPED CONVECTION WOULD HAVE THE POTENTIAL TO PRODUCE SOME LOCALIZED
HEAVY RAINFALL AND FLOODING. GIVEN THE EXPECTED ABUNDANCE OF RAIN
AND CLOUD COVER TODAY, WE TRENDED TEMPERATURES TOWARD THE LOWER END
OF GUIDANCE WITH HIGHS MAINLY IN THE LOW-MID 70S.
.SHORT TERM [TONIGHT THROUGH SUNDAY]...
THE UNUSUALLY WET PATTERN FOR APRIL WILL CONTINUE THROUGH THE
WEEKEND. HOWEVER, A CHANGE IS ON THE WAY. THE UPPER LOW OVER THE
CENTRAL PLAINS TONIGHT WILL LIFT TO THE NORTHEAST AND BECOME
ABSORBED IN THE NORTHERN STREAM ON SUNDAY. THE AXIS OF THE BROAD
UPPER TROUGH AND ASSOCIATED COLD FRONT WILL APPROACH LATE SUNDAY
WITH A DRIER AIRMASS ARRIVING EARLY NEXT WEEK. UNTIL THEN, SHOWERS
AND THUNDERSTORMS CAN BE EXPECTED EVEN DURING THE OVERNIGHT HOURS.
THE BEST CHANCE WILL BE ON SUNDAY WITH LIKELY TO CATEGORICAL POPS.
DESPITE THE EXTENSIVE CLOUD COVER AND RAIN CHANCES, TEMPS WILL
CONTINUE TO BE ABOVE SEASONAL LEVELS.
.LONG TERM [SUNDAY NIGHT THROUGH FRIDAY]...
THE COLD FRONT WILL PUSH THROUGH LATE MONDAY INTO EARLY TUESDAY
BUT SIGNIFICANT DRYING OF THE MID-UPPER LEVELS WILL HAVE ALREADY
BEGUN ON MONDAY WITH POPS ONLY IN THE CHANCE CATEGORY. TEMPERATURES
WILL NOT BE THAT COOL BEHIND THE FRONT, BUT THE LOWER HUMIDITY
WILL MAKE IT FEEL MORE PLEASANT THAN WHAT WE HAVE EXPERIENCED THE
PAST SEVERAL DAYS. ANOTHER COLD FRONT AND NEXT DECENT CHANCE FOR
RAIN WILL ARRIVE BY THE END OF THE WORK WEEK.
&&
.AVIATION...
[THROUGH 06Z SATURDAY] IFR CIGS PREVAILED AT THE TERMINALS AT TAF
ISSUANCE TIME, AND IFR-LIFR CIGS SHOULD LARGELY PREVAIL INTO THE MID
MORNING HOURS AS RAIN BUILDS INTO THE AREA. RAIN WILL LIKELY OCCUR
AT ALL OF THE TERMINALS AT SOME POINT TODAY, BUT TIMING IS SOMEWHAT
UNCERTAIN. CIGS SHOULD IMPROVE SOMEWHAT IN THE AFTERNOON, PERHAPS
INTO THE MVFR RANGE, BUT IFR-LIFR CIGS ARE LIKELY ONCE AGAIN
TONIGHT.
&&
.MARINE...
LIGHT SOUTHERLY WINDS ARE EXPECTED TODAY AND SATURDAY. WINDS WILL
INCREASE ON SUNDAY TO AT LEAST CAUTIONARY LEVELS AS A COLD FRONT
APPROACHES. WINDS AND SEAS WILL DECREASE AS THEY BECOME OFFSHORE
IN THE WAKE OF THE FRONT EARLY NEXT WEEK.
&&
.FIRE WEATHER...
RED FLAG CONDITIONS ARE NOT EXPECTED WITH HIGH RH PREVAILING THROUGH
THE WEEKEND. WETTING RAINS ARE LIKELY AND FUEL MOISTURE LEVELS
SHOULD STAY HIGH.
&&
.HYDROLOGY...
THOUGH NOT WIDESPREAD, RECENT HEAVY RAINS IN THE FL PANHANDLE,
SOUTHEAST AL, AND SOUTHWEST GA HAVE RESULTED IN SOME SHARP RISES IN
LOCAL RIVER STAGES. IN PARTICULAR, THE OCHLOCKONEE RIVER AT
THOMASVILLE, APALACHICOLA RIVER AT BLOUNTSTOWN, AND CHOCTAWHATCHEE
RIVER AT BRUCE ARE LIKELY TO BE ABOVE LOCAL ACTION STAGE FOR THE
NEXT SEVERAL DAYS, BUT REMAIN BELOW FLOOD STAGE. OVER THE NEXT
SEVERAL DAYS, WE EXPECT STORM TOTAL RAINFALL AMOUNTS TO RANGE FROM
ABOUT AN INCH IN NORTH FL, TO 4 INCHES IN SOUTHEAST AL AND PORTIONS
OF THE FL PANHANDLE. LOCALLY HIGHER AMOUNTS EXCEEDING 6 INCHES ARE
POSSIBLE. FORTUNATELY MANY OF THE RIVER STAGES IN SOUTHEAST AL AND
THE FL PANHANDLE WERE BELOW NORMAL BEFORE THIS WEEK. HOWEVER, THE
RAINS FROM THIS WEEK HAVE BROUGHT MANY OF THESE RIVERS TO ABOVE-
NORMAL FLOWS. DEPENDING ON WHERE THE HEAVIEST RAIN SETS UP OVER THE
NEXT SEVERAL DAYS, MORE OF THESE RIVERS COULD REACH LOCAL ACTION
STAGE NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TALLAHASSEE 77 66 84 69 81 / 70 30 40 50 70
PANAMA CITY 75 68 79 71 77 / 70 30 60 60 70
DOTHAN 72 63 79 67 77 / 70 30 60 80 70
ALBANY 73 62 79 66 78 / 60 30 40 60 70
VALDOSTA 76 64 84 67 81 / 70 30 40 30 70
CROSS CITY 79 66 84 67 83 / 60 30 40 30 60
APALACHICOLA 77 70 80 72 79 / 70 30 50 60 70
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...LAMERS
SHORT TERM...BARRY
LONG TERM...BARRY
AVIATION...LAMERS
MARINE...BARRY
FIRE WEATHER...LAMERS
HYDROLOGY...FOURNIER
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
721 PM EDT SAT APR 18 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA SUNDAY MORNING...AND AN
UPPER LEVEL DISTURBANCE WILL MOVE THROUGH SUNDAY AFTERNOON AND
EVENING. A COLD FRONT WILL APPROACH THE AREA MONDAY AND WILL CROSS
THE AREA MONDAY NIGHT. HIGH PRESSURE WILL PREVAIL TUESDAY THROUGH
THURSDAY. ANOTHER COLD FRONT COULD STALL OVER OR CLOSE TO THE REGION
LATE WEEK INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THIS EVENING...THE RISK FOR ISOLATED TO SCATTERED SHOWERS WILL
LINGER INTO THE EARLY EVENING HOURS WITH WEAK INSTABILITY IN
PLACE. CONVECTION WILL BE DIURNAL IN NATURE AND MAINLY DRIVEN BY
MESOSCALE BOUNDARY COLLISIONS. THE HIGHER RISK FOR MEASURABLE
RAINFALL WILL BE PRIMARY CONFINED TO NORTHERN PORTIONS OF
DORCHESTER...COLLETON AND BERKELEY COUNTIES...POSSIBLY EXTENDING
AS FAR EAST AS CHARLESTON COUNTY. INCREASED POPS TO 40-50 PERCENT
IN THIS AREA WITH 20-30 PERCENT CHANCE POPS ELSEWHERE WHERE
CONVECTION WILL BE MORE SPARSE. ACROSS THE FAR SOUTH...OUTFLOW
BOUNDARY SPARKING STRONGER CONVECTION OVER FAR SOUTHEAST
GEORGIA/NORTHEAST FLORIDA BETWEEN SAINT SIMONS AND JACKSONVILLE IS
MOVING STEADILY NORTH. THE BULK OF THIS ACTIVITY IS EXPECTED TO
REMAIN SOUTH OF THE ALTAMAHA RIVER...HOWEVER THE ATMOSPHERE
BETWEEN SAVANNAH AND DARIEN HAS YET TO BE OVERTURNED BY
CONVECTION. WILL SHOW 30 PERCENT POPS ACROSS THE FAR SOUTH FOR THE
NEXT FEW HOURS TO TAKE THIS TREND INTO ACCOUNT.
OVERNIGHT...INCOMING GUIDANCE HAS BACKED OFF A BIT ON THE AMOUNT
OF SHOWER ACTIVITY THAT WILL REDEVELOP LATE AS A DEVELOPING WARM
FRONT LIFTS NORTH ACROSS THE AREA. THE LATEST RAP AND H3R ARE
TRENDING WITH THE 18Z NAM IN KEEPING THE STRONGEST LOW-LEVEL
JETTING/ISENTROPIC ASSENT WEST OF THE AREA THROUGH SUNRISE...WHICH
SHOULD TRANSLATE TO LESS SHOWER/TSTM ACTIVITY. IT IS UNCLEAR
WHETHER THIS TREND WILL PERSIST...BUT THERE IS ENOUGH EVIDENCE IN
THE VARIOUS DATA SETS TO LOWER POPS SLIGHTLY FOR THE OVERNIGHT
PERIOD. WILL LIMIT POPS TO THE CHANCE CATEGORY ALL AREAS AND KEEP
ANY MENTION OF LIKELY POPS UNTIL AFTER SUNRISE SUNDAY. WILL
CONTINUE TO MONITOR MODEL TRENDS CAREFULLY AND MAKE FURTHER
ADJUSTMENTS WITH THE LATE EVENING UPDATE AFTER 00Z UPPER AIR DATA
ARE RECEIVED AND ANALYZED.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY MORNING...A WARM FRONT WILL LIFT NORTH OF THE REGION.
OVERRUNNING SHOWERS...PERHAPS ACCOMPANIED BY ISOLATED
THUNDERSTORMS...WILL INITIALLY FOCUS IN THE VICINITY OF THIS
BOUNDARY. THUS...MORNING POPS TAPERED FROM LIKELY NORTH/INLAND TO
CHANCE SOUTH. AFTER THE BOUNDARY LIFTS NORTH...THERE MAY BE A BREAK
IN PRECIPITATION COVERAGE FOR A WIDE SWATH OF THE FORECAST AREA LATE
MORNING INTO EARLY AFTERNOON. THEN...ON THE EASTERN PERIPHERY OF AN
UPSTREAM LONGWAVE TROUGH...A SHORTWAVE TROUGH AND AND ASSOCIATED
BAND OF DYNAMIC FORCING FOR ASCENT/BAND OF ENHANCED WARM CONVEYOR
BELT MOISTURE WILL EJECT EAST/NORTHEAST ACROSS THE REGION...WITHIN
AN ENVIRONMENT FEATURING SOME DEGREE OF DESTABILIZATION AND 0-6 KM
BULK SHEAR 35-45 KNOTS. THIS REGIME WILL SUPPORT MULTICELL
SHOWERS/THUNDERSTORMS...JUSTIFYING LIKELY/CATEGORICAL POPS. WHILE
THE DEGREE OF DESTABILIZATION REMAINS UNCERTAIN DUE TO CLOUD
COVER...SUFFICIENT INSTABILITY SHOULD DEVELOP WITHIN THIS
FORCED/SHEARED ENVIRONMENT TO PRODUCE A THREAT FOR AT LEAST POCKETS
OF SEVERE WEATHER PRIMARILY PRODUCING DAMAGING WIND GUSTS SUNDAY
AFTERNOON. THUS...SPC HAS UPGRADED TO A SLIGHT RISK FOR SEVERE
WEATHER SUNDAY. ALSO...SINCE PWATS WILL APPROACH 2 INCHES...ENHANCED
RAINFALL RATES COULD PRODUCE A LOCALIZED FLOOD THREAT IF/WHERE
PERSISTENT AND/OR MULTIPLE THUNDERSTORMS OCCUR.
THE SHORTWAVE WILL PUSH OFF THE COAST SUNDAY NIGHT...AND ELEVATED
POPS DURING THE EVENING SHOULD DECREASE BELOW 15 PERCENT AS SOMEWHAT
DRIER AIR/TEMPORARY SUBSIDENCE DEVELOP OVERNIGHT INTO EARLY MONDAY.
THE LONGWAVE TROUGH WILL DRIVE A SURFACE COLD FRONT TOWARD THE
REGION MONDAY. AHEAD OF THE FRONT...WARMING/DESTABILIZATION AND
STRENGTHENING LOW/MID LEVEL WIND FIELDS WILL DEVELOP...AND
THUNDERSTORMS WILL LIKELY DEVELOP OVER THE REGION AND/OR ADVANCE
INTO THE REGION FROM UPSTREAM MONDAY AFTERNOON/EVENING. FORECAST
UNCERTAINTY REGARDING THUNDERSTORM COVERAGE ARISES FROM DRYING ALOFT
DEPICTED BY MODEL SOUNDINGS...PERHAPS LIMITING COVERAGE OF
CONVECTION. THUS...CAPPED POPS AT 30-50 PERCENT...HIGHEST INLAND.
DESPITE THE POTENTIAL LIMITING INFLUENCE OF THIS DRY AIR...DYNAMIC
FORCING FOR ASCENT AND KINEMATIC/THERMODYNAMIC PARAMETERS SUGGEST A
POTENTIAL FOR ORGANIZED SEVERE WEATHER IN THE REGION MONDAY
AFTERNOON/EVENING.
MONDAY NIGHT...POPS LINGER BUT GRADUALLY DECREASE AS THE COLD FRONT
MOVES THROUGH. THE THREAT FOR SEVERE WEATHER SHOULD WANE AFTER DARK.
TUESDAY...HIGH PRESSURE WILL PUSH A DRIER AIRMASS INTO THE
REGION...ACCOMPANIED BY TEMPERATURES MAINLY 75-80F.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A RELATIVELY DRY AND SEASONABLE PATTERN WILL BE IN PLACE TUESDAY
NIGHT THROUGH THURSDAY WITH ZONAL FLOW ALOFT AND WEAK HIGH PRESSURE
AT THE SURFACE. HIGHS WILL CLIMB INTO THE LOWER 80S WITH LOWS IN THE
50S/60S. A WEAKENING COLD FRONT WILL DROP INTO THE REGION THURSDAY
NIGHT OR FRIDAY...POTENTIALLY PRODUCING SCATTERED SHOWERS. THIS
FRONT WILL LIKELY STALL OVER OR CLOSE TO THE REGION....THEN A
PROGRESSIVE UPPER SHORTWAVE WILL PUSH THROUGH THE AREA AROUND
SATURDAY...BRINGING INCREASING POPS.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
KCHS...SHOWER ACTIVITY BETWEEN KRBW-KDYB SHOULD DIMINISH AND
REMAIN WEST OF THE TERMINAL THROUGH 03Z. CIGS ARE EXPECTED TO
LOWER SLOWLY OVERNIGHT AS A WARM FRONT APPROACHES FROM THE SOUTH.
GUIDANCE AND FORECAST SOUNDINGS SUPPORT IFR CIGS DEVELOPING AFTER
MIDNIGHT AND REMAINING IN PLACE THROUGH SUNRISE...THEN SLOWLY
RISING AS THE FRONT LIFTS NORTH. A BAND OF RAIN/TSTMS WILL LIKELY
ACCOMPANY THE FRONT...SO WILL SHOW MVFR VSBYS IN -RA FROM 15-18Z.
A RISK FOR TSTMS WILL INCREASE LATE IN THE TAF PERIOD...BUT
TIMING TOO UNCERTAIN THIS FAR OUT FOR A MENTION.
KSAV...SHOWER ACTIVITY FROM KSSI-KJAX SHOULD REMAIN WELL TO THE
SOUTH. WILL WATCH FOR POSSIBLE REDEVELOPMENT ALONG MESOSCALE
BOUNDARY COLLISIONS...BUT ATTM NO IMPACTS ARE EXPECTED AT KSAV. A
WARM FRONT IS EXPECTED TO DEVELOP AND LIFT NORTH OVERNIGHT/EARLY
SUNDAY. BEST LIFT/RISK FOR LOWER CIGS WILL REMAIN NORTH OF THE
SAVANNAH RIVER...BUT ENOUGH EVIDENCE IS THERE TO JUSTIFY A PERIOD
OF LOW-END MVFR CIGS FROM ROUGHLY 07-12Z WITH VFR THEREAFTER.
COULD SEE A BRIEF TRANSITION PERIOD 04-07Z...BUT TIMING IS
UNCERTAIN. WHILE THE RISK FOR IFR CIGS IS THERE...BETTER
PROBABILITIES WILL REMAIN NORTH OF THE TERMINAL. A RISK FOR TSTMS
WILL INCREASE LATE IN THE TAF PERIOD...BUT TIMING TOO UNCERTAIN
THIS FAR OUT FOR A MENTION.
EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY SUNDAY AFTERNOON
INTO SUNDAY NIGHT...ESPECIALLY WITHIN SHOWERS/THUNDERSTORMS. OUTSIDE
SCATTERED SHOWERS/THUNDERSTORMS AS A COLD FRONT APPROACHES THEN
MOVES THROUGH THE REGION...MAINLY VFR MONDAY AND MONDAY NIGHT...THEN
VFR THROUGH MID WEEK.
&&
.MARINE...
TONIGHT...THE SETUP WILL CONTINUE TO SUPPORT QUIET
CONDITIONS ACROSS THE LOCAL WATERS. A SUBTLE WARM FRONT WILL LIFT
NORTHWARD AND A PREVAILING EAST-SOUTHEAST TO SOUTHEAST FLOW WILL
GRADUALLY BECOME MORE SOUTHERLY LATE. WINDS WILL BE LESS THAN 10 KT
WITH SEAS 2-3 FT.
A WARM FRONT WILL LIFT NORTH OF THE WATERS SUNDAY...FOLLOWED BY
INTENSIFYING SOUTH/SOUTHWEST FLOW. THE PROBABILITY FOR SMALL CRAFT
ADVISORY CONDITIONS WILL INCREASE ESPECIALLY SUNDAY NIGHT UNTIL A
COLD FRONT ARRIVES MONDAY NIGHT...ESPECIALLY CLOSE TO THE COAST
INCLUDING CHARLESTON HARBOR.
THE POTENTIAL EXISTS FOR THUNDERSTORMS WITH STRONG WINDS OVER THE
WATERS SUNDAY AFTERNOON/EVENING AND AGAIN MONDAY AFTERNOON/EVENING.
AFTER THE COLD FRONT PASSES...A QUIETER PATTERN WILL DEVELOP TUESDAY
UNTIL LATE WEEK AS HIGH PRESSURE PREVAILS.
&&
.TIDES/COASTAL FLOODING...
HAVE AGAIN OPTED AGAINST A COASTAL FLOOD ADVISORY. WINDS ARE
ONSHORE WITH A SEABREEZE SETTING UP...BUT ARE STILL WEAK.
ASTRONOMICAL INFLUENCES ARE LIKELY AT THEIR PEAK BUT CURRENT TIDAL
DEPARTURES ARE ONLY BETWEEN 0.2-0.3 FT...AND SHOULD DECREASE
FURTHER AS HIGH TIDE APPROACHES.
THERE IS A CHANCE THAT THE HIGH TIDE COULD REACH OR SLIGHTLY EXCEED
7.0 FT MLLW ON CHARLESTON HARBOR SUNDAY AND MONDAY EVENINGS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
637 AM EDT FRI APR 17 2015
.SYNOPSIS...
A LOW-LEVEL WEDGE WILL REMAIN IN PLACE THROUGH EARLY TODAY AND
BEGIN GRADUALLY DISSIPATING THIS AFTERNOON. AN UPPER DISTURBANCE
WILL CONTRIBUTE TO SOME SHOWER ACTIVITY TODAY. AN UPPER RIDGE WILL
PROVIDE FAIR WEATHER SATURDAY. EXPECT INCREASING MOISTURE AND
PRECIPITATION CHANCES WITH SHOWERS AND POSSIBLY THUNDERSTORMS
SUNDAY AND SUNDAY NIGHT. HEAVY RAIN MAY OCCUR. THE BULK OF THE
MOISTURE WILL SHIFT TO OUR EAST MONDAY AHEAD OF A WEAK COLD FRONT
THAT IS EXPECTED TO MOVE THROUGH THE AREA MONDAY AFTERNOON. FAIR
WEATHER IF FORECAST BEHIND THE FRONT LATE MONDAY THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE MODELS INDICATE DIMINISHED ISENTROPIC LIFT TODAY WITH THE
WEDGE PATTERN DISSIPATING BY THE MIDDLE OF THE DAY. THERE WILL BE
LIFT ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH. THE MODELS SHOW
THE GREATER FORCING ASSOCIATED WITH THE UPPER FEATURE AFFECTING
THE SOUTH PART TODAY. THE MODELS HAVE TRENDED WITH INCREASING POPS.
THE ARW AND SPC WRF DISPLAY SCATTERED COVERAGE OF SHOWERS. THE
HRRR IS TRENDING WITH GREATER COVERAGE APPROACHING THE CSRA BY
EARLY AFTERNOON. INSTABILITY ASSOCIATED WITH THE MID-LEVEL
SHORTWAVE TROUGH PLUS THE BREAK DOWN OF THE SURFACE WEDGE PATTERN
SUGGESTS POSSIBLE THUNDERSTORMS THIS AFTERNOON. BELIEVE CLOUDINESS
WILL HELP KEEP INSTABILITY WEAK. THE MODELS ALSO INDICATE WEAK
SHEAR. BELIEVE ANY THUNDERSTORMS THIS AFTERNOON WILL BE ISOLATED.
THERE IS LOW CONFIDENCE WITH THE HIGH TEMPERATURE FORECAST TODAY
BECAUSE OF TIMING UNCERTAINTY WITH THE DISSIPATING WEDGE PATTERN.
THE MODELS TYPICALLY DIMINISH THE WEDGE TOO QUICKLY SUPPORTING THE
COOLER GUIDANCE.
THE MODELS DISPLAYED LINGERING HIGH LOW-LEVEL MOISTURE TONIGHT. THE
GFS HAD MORE MID-LEVEL SHORTWAVE TROUGHING AFFECTING MAINLY THE
SOUTH PART OF THE FORECAST AREA TONIGHT. THE GUIDANCE CONSENSUS
SUPPORTED CHANCE POPS MAINLY IN THE SOUTH PART. THERE MAY BE AREAS
OF FOG BECAUSE OF THE HIGH LOW-LEVEL MOISTURE WITH LIGHT WIND PLUS
THE NAM FORECAST OF MID-LEVEL DRYING. THE GUIDANCE TEMPERATURES
WERE CLOSE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
LATEST MODEL RUNS TRENDING SLOWER WITH PROGRESSION OF SYSTEMS
AFFECTING OUR REGION. UPPER LOW WILL CONTINUE TO MEANDER OVER THE W
CONUS...FOUR CORNERS/FRONT RANGE REGION...THROUGH SATURDAY WITH THE
MAIN UPPER FLOW REMAINING WELL TO OUR NORTH ACROSS CANADA. LATEST
MODEL RUNS INDICATE UPPER SHORT WAVE TO TRAVERSE OUR REGION
FRIDAY...WITH UPPER RIDGE AXIS NOT SHIFTING EAST INTO OUR REGION
UNTIL SATURDAY. LOW LEVEL WEDGE WILL TRY TO GRADUALLY ERODE FRIDAY.
MODELS INDICATE WEDGE ERODING DURING THE MORNING...BUT MODELS TEND
TO ERODE WEDGES TOO QUICKLY. HOWEVER...WEDGE MAY INDEED ERODE DURING
THE AFTERNOON. WITH UPPER SHORT WAVE...DIURNAL HEATING...AND
APPEARANCE OF SUFFICIENT ATMOSPHERIC MOISTURE OVER THE
REGION...BUMPED UP POPS FOR FRIDAY. SATURDAY NOW APPEARS WILL BE
GENERALLY FAIR...WITH UPPER RIDGE AXIS AND DRIER MID LEVEL AIR OVER
THE REGION...THOUGH DIURNAL HEATING AND SEA BREEZE COULD LEAD TO
SOME AFTERNOON SHOWERS AND A POSSIBLE THUNDERSTORM MAINLY SOUTH.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
FRONT RANGE UPPER LOW IS PROGGED TO GRADUALLY OPEN AND SHIFT EAST
INTO THE CENTRAL CONUS SAT NT AND SUN IN RESPONSE TO NORTHERN STREAM
UPPER ENERGY DIGGING SE FROM W CANADA/PAC NW INTO THE NORTHERN
ROCKIES/N PLAINS. UPPER HIGH AXIS WILL SHIFT TO OUR EAST OFFSHORE
SAT NT. AHEAD OF THE UPPER LOW...SOUTHERN STREAM UPPER IMPULSES WILL
MOVE NE FROM NORTHERN MEXICO INTO THE LOWER MISSISSIPPI VALLEY/GULF
COAST REGION. THIS WILL LEAD TO SURFACE LOW DEVELOPING OVER THE
LOWER MISSISSIPPI VALLEY AND TRACKING NE INTO THE MIDWEST/GREAT
LAKES REGION...WHILE SURFACE HIGH SHIFTS SE INTO NEW ENGLAND. AN
INCREASING SE LOW LEVEL FLOW SATURDAY...BECOMING SW SUNDAY...WILL
BRING INCREASING MOISTURE BACK INTO OUR REGION. WITH MODELS SLOWING
PROGRESSIONS OF SYSTEMS DOWN SOME...IT NOW APPEARS AXIS OF HIGH
MOISTURE AND ASSOCIATED SHOWERS AND POSSIBLE THUNDERSTORMS WILL
PROVIDE THE BEST THREAT OF PRECIPITATION AND POSSIBLY HEAVY
RAIN...SUNDAY AFTERNOON THRU SUN NT TIME FRAME. THERE ARE
INDICATIONS THAT WITH MUCH HIGHER THAN NORMAL PRECIPITABLE WATER
VALUES FOR THIS TIME OF YEAR...THAT HEAVY RAIN WILL BE POSSIBLE.
MODELS SHIFT THE AXIS OF HIGHEST MOISTURE TO OUR EAST BY MONDAY
AHEAD OF A COLD FRONT PASSING THROUGH MONDAY AFTERNOON.
HOWEVER...SOME SHOWER AND POSSIBLE THUNDERSTORM ACTIVITY WILL BE
POSSIBLE WITH THE FROPA. DRIER AIR AND HIGH PRESSURE BEHIND THE
FRONT APPEARS WILL PROVIDE FAIR WEATHER FOR OUR REGION MONDAY NIGHT
THROUGH MID WEEK.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
COOL WEDGE REMAINS IN PLACE WITH MAINLY DRIZZLE OVER THE AREA
EARLY THIS MORNING. IFR CIGS START THE FORECAST. MOST OF THE GFS
AND NAM MOS PLUS SREF GUIDANCE SHOW AN IMPROVING TREND INTO THE
MVFR CATEGORY THIS AFTERNOON. THE NAM SURFACE-BASED LI PATTERN
SUGGESTED THE WEDGE PATTERN WILL DISSIPATE BY THE MIDDLE OF THE
DAY. CONFIDENCE IS NOT HIGH WITH THE TIMING. THE MODELS TYPICALLY
DIMINISH WEDGES TOO QUICKLY. THERE WILL BE LIFT ASSOCIATED WITH A
MID-LEVEL SHORTWAVE TROUGH TODAY. THE MODELS INDICATED FORCING
ASSOCIATED WITH THE UPPER FEATURE WILL BE STRONGER IN THE SOUTH.
SHOWERS AND ASSOCIATED RESTRICTIONS MAY BE MORE WIDESPREAD AT AGS
AND DNL AND WE FORECASTED MORE PESSIMISTIC CONDITIONS AT THESE
TERMINALS THAN FARTHER NORTH. THE SPC WRF AND ARW MODELS DISPLAY
SCATTERED SHOWER COVERAGE. THE HRRR IS TRENDING WITH GREATER
COVERAGE APPROACHING THE CSRA BY EARLY AFTERNOON. INSTABILITY
ASSOCIATED WITH THE MID-LEVEL SHORTWAVE TROUGH PLUS THE BREAK
DOWN OF THE SURFACE WEDGE PATTERN SUGGESTS POSSIBLE THUNDERSTORMS
THIS AFTERNOON. BELIEVE CLOUDINESS WILL HELP KEEP INSTABILITY
WEAK. BELIEVE ANY THUNDERSTORMS THIS AFTERNOON WILL BE ISOLATED
WITH THE CHANCE TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT
THIS TIME.
THE MODELS DISPLAYED LINGERING HIGH LOW-LEVEL MOISTURE TONIGHT. THE
GFS HAD MORE MID-LEVEL SHORTWAVE TROUGHING AFFECTING MAINLY THE
SOUTH PART OF THE FORECAST AREA TONIGHT SUPPORTING A CONTINUED
SHOWER CHANCE. THERE MAY BE AREAS OF FOG BECAUSE OF THE HIGH LOW-
LEVEL MOISTURE WITH LIGHT WIND PLUS THE NAM FORECAST OF MID-LEVEL
DRYING.
EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR OR IFR CONDITIONS
MAY OCCUR SATURDAY MORNING BECAUSE OF RESIDUAL LOW-LEVEL
MOISTURE. A WARM FRONT WILL LIKELY BRING WIDESPREAD MVFR OR IFR
CONDITIONS SATURDAY NIGHT THROUGH EARLY MONDAY MORNING.
&&
.HYDROLOGY...
RAINFALL ACROSS THE AREA THE PAST COUPLE OF DAYS COMBINED WITH
RELEASES FROM PARR RESERVOIR AND LAKE MURRAY WILL PRODUCES RISES
ALONG THE CONGAREE RIVER. THE RIVER IS FORECAST TO CREST JUST
BELOW THE ADVISORY STAGE OF 10 FEET AT COLUMBIA TODAY. A CREST
NEAR FLOOD STAGE OF 115 FEET AT CAROLINA EASTMAN MAY OCCUR TODAY.
THIS WILL PRODUCE SOME MINOR FLOODING ALONG THE THREE RIVERS
GREENWAY AND ALSO DOWNSTREAM FROM COLUMBIA OVER THE WEEKEND AT THE
CONGAREE NATIONAL PARK. ALL OTHER FORECAST POINTS ACROSS THE
MIDLANDS AND CSRA ARE EXPECTED TO REMAIN BELOW FLOOD STAGE THROUGH
SATURDAY...BUT POSSIBLE HEAVY RAIN IN THE HEADWATERS SUNDAY COULD
LEAD TO RIVER FLOODING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
215 AM EDT FRI APR 17 2015
.UPDATE...
AREA OF RAIN CONTINUES TO BLOSSOM ACROSS THE CWFA THIS EVENING.
LATEST RUNS OF THE HRRR SHOW THE RAINFALL SHOULD TAPER OFF AFTER
06Z. UPDATED THE POPS EARLIER THIS EVENING...AND JUST UPDATED THEM
AGAIN TO CATEGORICAL OVER A GOOD PORTION OF THE CWFA. HAVE ALSO
TWEAKED THE HOURLY TEMPS AND DEWPOINTS. CHANCES OF CONVECTION
REMAIN SMALL...BUT SHOULD CONTINUE THROUGH MIDNIGHT.
&&
.PREV DISCUSSION... /ISSUED 348 PM EDT THU APR 16 2015/
SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
A WET/UNSETTLED PATTERN LOOKS TO PERSIST THROUGH THE SHORT TERM.
THE WEDGE PERSISTS THIS AFTERNOON AND SHOULD CONTINUE INTO THE
OVERNIGHT WITH THE WEDGE GRADUALLY BREAKING DOWN FRIDAY. SHOWERS
AND A FEW THUNDERSTORMS WERE INCREASING TO THE WEST AND SHOULD
CONTINUE TO MOVE NORTHEAST...WITH HIGH RESOLUTION MODELS SHOWING
WIDESPREAD RAINFALL FOR MUCH OF THE NIGHT. THIS SHOULD CONTINUE INTO
FRIDAY MORNING. MOST UNSTABLE AIR WILL BE AROUND THE EDGE OF THE
COOLER AIR AND HAVE INCLUDED THUNDER FOR TONIGHT ALONG THE NORTHERN
AND WESTERN ZONES. SOME GENERAL INCREASE IN INSTABILITY FOR FRIDAY
AND HAVE MENTIONED THUNDER ACROSS THE AREA. MODELS HINT AT A BREAK
UNTIL NEXT WAVE APPROACHES THE FORECAST AREA ON SATURDAY...SO HAVE
REDUCED THE POPS FOR FRIDAY NIGHT.
FLOODING ISSUES MAY BE HIT AND MISS AND HAVE NOT ISSUED ANY FLOOD
WATCH. SOME LOCAL RIVER AND STREET FLOODING WILL CONTINUE TO BE
POSSIBLE.
TEMPERATURES THIS AFTERNOON ARE RUNNING A BIT LOWER THAN FORECAST
AND MAY HOLD NEAR STEADY OVERNIGHT WITH THE EASTERLY WINDS. SOME
WARMING EXPECTED ON FRIDAY.
41
LONG TERM /SATURDAY THROUGH THURSDAY/...
NO MAJOR CHANGES MADE TO THE EXTENDED FORECAST. MODELS STILL A
BIT SLOWER WITH INCREASING DEEP MOISTURE ON SATURDAY WITH THE BEST
MOISTURE NOT BEGINNING TO MOVE IN UNTIL 00Z SUN. BEST OPPORTUNITY
FOR RAINFALL CONTINUES TO BE SUN/SUN NIGHT WITH HIGH SHOWERS
CHANCES AND A CHANCE OF THUNDERSTORMS ACROSS THE AREA. PWS ACROSS
THE AREA INCREASE INTO THE 1.5 TO 1.75 INCH RANGE BEGINNING 00Z
SUN THROUGH 00Z MON. THIS WILL BRING PERIODS OF MODERATE TO HEAVY
RAIN THIS WEEKEND ACROSS THE ENTIRE CWA. THE POTENTIAL FOR
LOCALIZED FLOODING WILL NEED TO BE CLOSELY MONITORED. A COLD FRONT
MOVES ACROSS THE AREA MONDAY/MONDAY NIGHT AND RAIN CHANCES WILL
END MONDAY NIGHT. TUESDAY AND WEDNESDAY ARE EXPECTED TO BE DRY AS
THE WESTERLY UPPER FLOW DRIES OUT. A SHORT WAVE IN THE UPPER FLOW
THU MORNING WILL NEED TO BE WATCHED FOR POSSIBLE LIGHT PRECIP
CHANCES. HAVE INTRODUCE A SLIGHT CHANCE OF PRECIP FOR NOW.
TEMPERATURES ARE GENERALLY EXPECTED TO BE NEAR TO ABOVE NORMAL.
01
PREVIOUS LONG TERM DISCUSSION /FRIDAY NIGHT THROUGH WEDNESDAY/
/ISSUED AT 505 AM EDT THU APR 16 2015/...WE LOOK TO BE IN BETWEEN
SYSTEMS FRIDAY NIGHT AS WEAK SURFACE HIGH PRESSURE AND A SHORT
WAVE RIDGE ALOFT PREDOMINATE. THIS WILL TRANSLATE TO ONLY LOW POPS
DURING THE EVENING FOR CENTRAL AND PARTS OF NORTH GEORGIA.
FORECAST LOW TEMPERATURES RUNNING 8-10 DEGREES ABOVE NORMAL.
MODELS NOW SLOWER WITH INCREASING DEEP MOISTURE ON SATURDAY IN THE
SW UPPER FLOW AND INCREASING SOUTHERLY LOW LEVEL FLOW. BEST RAIN
CHANCES NOW LOOK TO BE LATE SATURDAY AND LIGHT.
DEEPEST MOISTURE INCREASES SATURDAY NIGHT AND CONTINUES INTO SUNDAY
NIGHT WITH HIGH SHOWERS CHANCES AND A CHANCE OF THUNDERSTORMS ACROSS
THE AREA.
A COLD FRONT MOVES ACROSS THE AREA MONDAY/MONDAY NIGHT AND RAIN CHANCES
WILL END MONDAY NIGHT.
TUESDAY AND WEDNESDAY ARE EXPECTED TO BE DRY AS THE WESTERLY UPPER
FLOW DRIES OUT. A SHORT WAVE IN THE UPPER FLOW LATE WEDNESDAY WILL
NEED TO BE WATCHED FOR POSSIBLE LIGHT PRECIP CHANCES.
UPDATED...
AT THIS TIME...A PERIOD OF MODERATE TO HEAVY RAIN WILL BE POSSIBLE THIS
WEEKEND...MOST SO FOR NORTHEAST GEORGIA. THE POTENTIAL FOR LOCALIZED FLOODING
WILL NEED TO BE CLOSELY MONITORED.
TEMPERATURES ARE GENERALLY EXPECTED TO BE NEAR TO ABOVE NORMAL.
BDL
&&
.AVIATION...
06Z UPDATE...
IFR OR LOWER CONDITIONS ARE EXPECTED TO PREDOMINATE ACROSS THE AREA
THROUGH 14Z...WITH CONDITIONS IMPROVING TO MVFR BY 16Z-18Z MOST
AREAS. MAY SEE SOME BRIEF...SCATTERED PERIODS OF VFR CONDITIONS
BETWEEN 20Z AND 02Z. SOME LIGHT RAIN OR SHOWERS ARE POSSIBLE THROUGH
16Z...WITH MAINLY SHOWERS SCATTERED ACROSS THE AREA...AND A FEW
ISOLATED THUNDERSTORMS...16Z-02Z. EAST WINDS 4-8KT THROUGH 16Z WITH
WINDS BECOMING SOMEWHAT VARIABLE IN DIRECTION 16Z-20Z. WINDS ARE
EXPECTED TO BE GENERALLY WESTERLY AFTER 20Z...BUT WILL BE LIGHT AT
5KTS OR LESS.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 54 72 58 81 / 90 40 20 40
ATLANTA 53 73 61 77 / 100 50 20 50
BLAIRSVILLE 52 71 54 75 / 100 40 20 40
CARTERSVILLE 53 73 57 79 / 100 50 20 50
COLUMBUS 57 73 61 79 / 100 60 20 50
GAINESVILLE 53 71 58 77 / 100 40 20 40
MACON 57 72 58 79 / 100 60 20 40
ROME 54 73 57 78 / 60 40 20 50
PEACHTREE CITY 53 73 57 77 / 100 50 20 50
VIDALIA 58 73 62 82 / 80 50 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1220 PM CDT FRI APR 17 2015
.UPDATE...
ISSUED AT 1050 AM CDT FRI APR 17 2015
WEAK RIDGING OVER THE REGION KEEPING MILD WEATHER IN PLACE. QUICK
MORNING WARM UP UNDER A MOSTLY SUNNY SKY AND TEMPS ON TRACK TO
HEAD INTO THE UPPER 70S. ALTHOUGH CUMULUS CLOUDS ARE EXPECTED TO
DEVELOP LATER THIS AFTERNOON...COVERAGE SHOULD BE LIGHTER IN THE
NORTH THAN THE SOUTHERN TIER OF THE STATE...AND SHOULD NOT
INTERFERE TOO MUCH WITH THE DIURNAL TREND UNDER SUCH LIGHT WINDS.
FORECAST DOING WELL...HAVE ONLY MADE SOME MINOR ADJUSTMENTS. MAJOR
UPDATES ARE NOT ANTICIPATED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CDT FRI APR 17 2015
A DENSE FOG ADVISORY ISSUED AROUND 2 AM FOR EASTERN IL WILL BE
ALLOWED TO CONTINUE THROUGH 9 AM CDT. THE PAST HOUR OR TWO THE DENSE
FOG WITH VSBYS 1/4 MILE OR LESS HAS BEEN CONFINED TO AREAS EAST OF I-
57 AND COULD EXPAND FURTHER WEST OF I-57 WITH AREAS OF FOG AND
PATCHY DENSE FOG AS FAR WEST AS I-55 PER HRRR MODEL UNTIL 9 AM. ONCE
THE FOG LIFTS LATER THIS MORNING A NICE MILD SPRING DAY IS SHAPING
UP ACROSS CENTRAL AND SOUTHEAST IL WITH WEAK HIGH PRESSURE OVER IN
AND SOME UPPER LEVEL RIDGING INTO IL GIVING MOSTLY SUNNY SKIES AND
LIGHT WINDS AND MILD HIGHS IN THE MID TO UPPER 70S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 331 AM CDT FRI APR 17 2015
DRY CONDITIONS STILL EXPECTED TO CONTINUE ACROSS CENTRAL AND
SOUTHEAST IL THROUGH AT LEAST SAT MORNING WITH JUST ISOLATED SHOWERS
AND THUNDERSTORMS POSSIBLE DURING MID/LATE SAT AFTERNOON ALONG AND
SW OF A GALESBURG TO LINCOLN TO LAWRENCEVILLE LINE. UPPER LEVEL
RIDGE INTO THE OHIO RIVER VALLEY AND IL YET ON SATURDAY TO BRING ANOTHER
MILD SPRING DAY IN THE MID TO UPPER 70S SATURDAY, WITH MILDEST
READINGS NEAR THE IN BORDER WHERE MORE SUNSHINE EXPECTED.
LARGE CUTOFF UPPER LEVEL LOW OVER COLORADO TONIGHT AND SATURDAY GETS
ABSORBED BY NORTHERN STREAM CUTOFF LOW NORTH OF ND/MN SUNDAY AND
MONDAY. WARM AIR ADVECTION SHOWERS AND SCATTERED THUNDERSTORMS TO
SPREAD NE ACROSS CENTRAL AND SOUTHEAST IL DURING SATURDAY NIGHT
ESPECIALLY AFTER MIDNIGHT AND CONTINUE SUNDAY. FAIRLY STRONG SURFACE
LOW PRESSURE EJECTS NE FROM OK PANHANDLE TO NEAR CENTRAL IL BY
SUNSET SUNDAY AND SWEEPS A COLD FRONT EAST THROUGH IL SUNDAY NIGHT.
THIS TO LIKELY BRING MORE SHOWERS AND THUNDERSTORMS SUNDAY AND
SUNDAY NIGHT AND SPC HAS MARGINAL RISK OF SEVERE STORMS SW OF I-74
SUNDAY AFTERNOON INTO EARLY SUNDAY EVENING WITH SLIGHT RISK SW OF A
PITTSFIELD TO EFFINGHAM TO LAWRENCEVILLE LINE FOR LARGE HAIL AND
DAMAGING WIND GUSTS POSSIBLE. HIGHS SUNDAY MOSTLY IN THE LOWER 70S
WITH SOME UPPER 60S NORTH OF I-74.
A LARGE UPPER LEVEL TROF THEN DOMINATES THE MIDWEST MONDAY-THURSDAY
AS STRONG CUTOFF LOW MOVES SLOWLY EAST ACROSS THE NORTHERN GREAT
LAKES REGION. SHOWERS SHOULD DIMINISH TO WIDELY SCATTERED SHOWERS
OVER CENTRAL IL ON MONDAY WITH BEST CHANCES OF SHOWERS OVER IN AND
NORTHERN IL. COOLER HIGHS OF 60-65F MONDAY WITH MILDEST READINGS BY
LAWRENCEVILLE. HAVE DRY AND COOL CONDITIONS MONDAY NIGHT THROUGH TUE
NIGHT. THEN SMALL CHANCES OF SHOWERS WED/THU WITH A WEATHER SYSTEM
APPROACHING FROM THE SW WITH GFS MODEL TRENDING MUCH WETTER DURING
THIS TIME FRAME WHILE ECMWF MODEL IS KEEPING IL DRY. COOL HIGHS IN
THE UPPER 50S/LOWER 60S TUE-WED WITH LOWS IN THE UPPER 30S TO MID
40S, WITH COOLEST READINGS FROM I-74 NORTH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1216 PM CDT FRI APR 17 2015
DIURNAL CU ACROSS THE REGION DEVELOPING AND VERY FEW OVER
CMI...BUT MORE BKN TO THE SOUTH FOR SPI AND DEC POTENTIALLY
THROUGH THE AFTERNOON. STILL VERY LIGHT AND VARIABLE WINDS
EXPECTED ACROSS THE REGION...WITH MAINLY WESTERLY FLOW ALOFT.
STILL PLENTY OF LLVL MOISTURE IN THE BOUNDARY LAYER TO LEND TO A
SLIGHT REDUCTION OF VISIBILITY OVERNIGHT AND IN THE EARLY MORNING
HOURS. HAVE CONTINUED THE TREND TO MAINLY MVFR VIS...BUT WILL HAVE
TO KEEP A CLOSE EYE ON THE XOVER TEMPS THIS AFTERNOON. NOT MUCH IN
THE WAY OF MIXING IS ANTICIPATED AGAIN WITH THE LIGHT FLOW...BUT
SINCE WESTERN TERMINALS WERE RELATIVELY LIGHT VIS DROPS THIS
MORNING...EXPECT SOME OF THAT WILL TRANSLATE EASTWARD.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...07
LONG TERM...07
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1057 AM CDT FRI APR 17 2015
.UPDATE...
ISSUED AT 1050 AM CDT FRI APR 17 2015
WEAK RIDGING OVER THE REGION KEEPING MILD WEATHER IN PLACE. QUICK
MORNING WARM UP UNDER A MOSTLY SUNNY SKY AND TEMPS ON TRACK TO
HEAD INTO THE UPPER 70S. ALTHOUGH CUMULUS CLOUDS ARE EXPECTED TO
DEVELOP LATER THIS AFTERNOON...COVERAGE SHOULD BE LIGHTER IN THE
NORTH THAN THE SOUTHERN TIER OF THE STATE...AND SHOULD NOT
INTERFERE TOO MUCH WITH THE DIURNAL TREND UNDER SUCH LIGHT WINDS.
FORECAST DOING WELL...HAVE ONLY MADE SOME MINOR ADJUSTMENTS. MAJOR
UPDATES ARE NOT ANTICIPATED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CDT FRI APR 17 2015
A DENSE FOG ADVISORY ISSUED AROUND 2 AM FOR EASTERN IL WILL BE
ALLOWED TO CONTINUE THROUGH 9 AM CDT. THE PAST HOUR OR TWO THE DENSE
FOG WITH VSBYS 1/4 MILE OR LESS HAS BEEN CONFINED TO AREAS EAST OF I-
57 AND COULD EXPAND FURTHER WEST OF I-57 WITH AREAS OF FOG AND
PATCHY DENSE FOG AS FAR WEST AS I-55 PER HRRR MODEL UNTIL 9 AM. ONCE
THE FOG LIFTS LATER THIS MORNING A NICE MILD SPRING DAY IS SHAPING
UP ACROSS CENTRAL AND SOUTHEAST IL WITH WEAK HIGH PRESSURE OVER IN
AND SOME UPPER LEVEL RIDGING INTO IL GIVING MOSTLY SUNNY SKIES AND
LIGHT WINDS AND MILD HIGHS IN THE MID TO UPPER 70S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 331 AM CDT FRI APR 17 2015
DRY CONDITIONS STILL EXPECTED TO CONTINUE ACROSS CENTRAL AND
SOUTHEAST IL THROUGH AT LEAST SAT MORNING WITH JUST ISOLATED SHOWERS
AND THUNDERSTORMS POSSIBLE DURING MID/LATE SAT AFTERNOON ALONG AND
SW OF A GALESBURG TO LINCOLN TO LAWRENCEVILLE LINE. UPPER LEVEL
RIDGE INTO THE OHIO RIVER VALLEY AND IL YET ON SATURDAY TO BRING ANOTHER
MILD SPRING DAY IN THE MID TO UPPER 70S SATURDAY, WITH MILDEST
READINGS NEAR THE IN BORDER WHERE MORE SUNSHINE EXPECTED.
LARGE CUTOFF UPPER LEVEL LOW OVER COLORADO TONIGHT AND SATURDAY GETS
ABSORBED BY NORTHERN STREAM CUTOFF LOW NORTH OF ND/MN SUNDAY AND
MONDAY. WARM AIR ADVECTION SHOWERS AND SCATTERED THUNDERSTORMS TO
SPREAD NE ACROSS CENTRAL AND SOUTHEAST IL DURING SATURDAY NIGHT
ESPECIALLY AFTER MIDNIGHT AND CONTINUE SUNDAY. FAIRLY STRONG SURFACE
LOW PRESSURE EJECTS NE FROM OK PANHANDLE TO NEAR CENTRAL IL BY
SUNSET SUNDAY AND SWEEPS A COLD FRONT EAST THROUGH IL SUNDAY NIGHT.
THIS TO LIKELY BRING MORE SHOWERS AND THUNDERSTORMS SUNDAY AND
SUNDAY NIGHT AND SPC HAS MARGINAL RISK OF SEVERE STORMS SW OF I-74
SUNDAY AFTERNOON INTO EARLY SUNDAY EVENING WITH SLIGHT RISK SW OF A
PITTSFIELD TO EFFINGHAM TO LAWRENCEVILLE LINE FOR LARGE HAIL AND
DAMAGING WIND GUSTS POSSIBLE. HIGHS SUNDAY MOSTLY IN THE LOWER 70S
WITH SOME UPPER 60S NORTH OF I-74.
A LARGE UPPER LEVEL TROF THEN DOMINATES THE MIDWEST MONDAY-THURSDAY
AS STRONG CUTOFF LOW MOVES SLOWLY EAST ACROSS THE NORTHERN GREAT
LAKES REGION. SHOWERS SHOULD DIMINISH TO WIDELY SCATTERED SHOWERS
OVER CENTRAL IL ON MONDAY WITH BEST CHANCES OF SHOWERS OVER IN AND
NORTHERN IL. COOLER HIGHS OF 60-65F MONDAY WITH MILDEST READINGS BY
LAWRENCEVILLE. HAVE DRY AND COOL CONDITIONS MONDAY NIGHT THROUGH TUE
NIGHT. THEN SMALL CHANCES OF SHOWERS WED/THU WITH A WEATHER SYSTEM
APPROACHING FROM THE SW WITH GFS MODEL TRENDING MUCH WETTER DURING
THIS TIME FRAME WHILE ECMWF MODEL IS KEEPING IL DRY. COOL HIGHS IN
THE UPPER 50S/LOWER 60S TUE-WED WITH LOWS IN THE UPPER 30S TO MID
40S, WITH COOLEST READINGS FROM I-74 NORTH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 639 AM CDT FRI APR 17 2015
DENSE FOG MOVED IN FROM THE EAST LAST NIGHT AND IS NOW COVERING
CMI ONLY. DEC AND BMI HAVE SOME LIGHT FOG AND COULD SEE LOWER
CONDITIONS FOR A COUPLE OF HOURS THIS MORNING. SO WILL HAVE TEMPO
GROUP FOR CMI, DEC, AND BMI. SPI AND PIA SHOULD NOT SEE ANY FOG,
GIVEN THE TEMP/DEWPOINT SPREAD, ESPECIALLY AT PIA. BESIDES THE
FOG, HIGH CIRRUS WILL SPREAD OVER ALL TAF SITES THIS MORNING AND
WILL CONTINUE THROUGH THE AFTERNOON AND INTO TONIGHT. MORE FOG IS
POSSIBLE AGAIN TONIGHT, SO HAVE ADDED 3-4SM AT ALL SITES AROUND
MIDNIGHT. WINDS SHOULD BE LIGHT AND VARIABLE THROUGH THE PERIOD AS
HIGH PRESSURE WILL DOMINATE THE AREA NEXT 24HRS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...07
LONG TERM...07
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
639 AM CDT FRI APR 17 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CDT FRI APR 17 2015
A DENSE FOG ADVISORY ISSUED AROUND 2 AM FOR EASTERN IL WILL BE
ALLOWED TO CONTINUE THROUGH 9 AM CDT. THE PAST HOUR OR TWO THE DENSE
FOG WITH VSBYS 1/4 MILE OR LESS HAS BEEN CONFINED TO AREAS EAST OF I-
57 AND COULD EXPAND FURTHER WEST OF I-57 WITH AREAS OF FOG AND
PATCHY DENSE FOG AS FAR WEST AS I-55 PER HRRR MODEL UNTIL 9 AM. ONCE
THE FOG LIFTS LATER THIS MORNING A NICE MILD SPRING DAY IS SHAPING
UP ACROSS CENTRAL AND SOUTHEAST IL WITH WEAK HIGH PRESSURE OVER IN
AND SOME UPPER LEVEL RIDGING INTO IL GIVING MOSTLY SUNNY SKIES AND
LIGHT WINDS AND MILD HIGHS IN THE MID TO UPPER 70S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 331 AM CDT FRI APR 17 2015
DRY CONDITIONS STILL EXPECTED TO CONTINUE ACROSS CENTRAL AND
SOUTHEAST IL THROUGH AT LEAST SAT MORNING WITH JUST ISOLATED SHOWERS
AND THUNDERSTORMS POSSIBLE DURING MID/LATE SAT AFTERNOON ALONG AND
SW OF A GALESBURG TO LINCOLN TO LAWRENCEVILLE LINE. UPPER LEVEL
RIDGE INTO THE OHIO RIVER VALLEY AND IL YET ON SATURDAY TO BRING ANOTHER
MILD SPRING DAY IN THE MID TO UPPER 70S SATURDAY, WITH MILDEST
READINGS NEAR THE IN BORDER WHERE MORE SUNSHINE EXPECTED.
LARGE CUTOFF UPPER LEVEL LOW OVER COLORADO TONIGHT AND SATURDAY GETS
ABSORBED BY NORTHERN STREAM CUTOFF LOW NORTH OF ND/MN SUNDAY AND
MONDAY. WARM AIR ADVECTION SHOWERS AND SCATTERED THUNDERSTORMS TO
SPREAD NE ACROSS CENTRAL AND SOUTHEAST IL DURING SATURDAY NIGHT
ESPECIALLY AFTER MIDNIGHT AND CONTINUE SUNDAY. FAIRLY STRONG SURFACE
LOW PRESSURE EJECTS NE FROM OK PANHANDLE TO NEAR CENTRAL IL BY
SUNSET SUNDAY AND SWEEPS A COLD FRONT EAST THROUGH IL SUNDAY NIGHT.
THIS TO LIKELY BRING MORE SHOWERS AND THUNDERSTORMS SUNDAY AND
SUNDAY NIGHT AND SPC HAS MARGINAL RISK OF SEVERE STORMS SW OF I-74
SUNDAY AFTERNOON INTO EARLY SUNDAY EVENING WITH SLIGHT RISK SW OF A
PITTSFIELD TO EFFINGHAM TO LAWRENCEVILLE LINE FOR LARGE HAIL AND
DAMAGING WIND GUSTS POSSIBLE. HIGHS SUNDAY MOSTLY IN THE LOWER 70S
WITH SOME UPPER 60S NORTH OF I-74.
A LARGE UPPER LEVEL TROF THEN DOMINATES THE MIDWEST MONDAY-THURSDAY
AS STRONG CUTOFF LOW MOVES SLOWLY EAST ACROSS THE NORTHERN GREAT
LAKES REGION. SHOWERS SHOULD DIMINISH TO WIDELY SCATTERED SHOWERS
OVER CENTRAL IL ON MONDAY WITH BEST CHANCES OF SHOWERS OVER IN AND
NORTHERN IL. COOLER HIGHS OF 60-65F MONDAY WITH MILDEST READINGS BY
LAWRENCEVILLE. HAVE DRY AND COOL CONDITIONS MONDAY NIGHT THROUGH TUE
NIGHT. THEN SMALL CHANCES OF SHOWERS WED/THU WITH A WEATHER SYSTEM
APPROACHING FROM THE SW WITH GFS MODEL TRENDING MUCH WETTER DURING
THIS TIME FRAME WHILE ECMWF MODEL IS KEEPING IL DRY. COOL HIGHS IN
THE UPPER 50S/LOWER 60S TUE-WED WITH LOWS IN THE UPPER 30S TO MID
40S, WITH COOLEST READINGS FROM I-74 NORTH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 639 AM CDT FRI APR 17 2015
DENSE FOG MOVED IN FROM THE EAST LAST NIGHT AND IS NOW COVERING
CMI ONLY. DEC AND BMI HAVE SOME LIGHT FOG AND COULD SEE LOWER
CONDITIONS FOR A COUPLE OF HOURS THIS MORNING. SO WILL HAVE TEMPO
GROUP FOR CMI, DEC, AND BMI. SPI AND PIA SHOULD NOT SEE ANY FOG,
GIVEN THE TEMP/DEWPOINT SPREAD, ESPECIALLY AT PIA. BESIDES THE
FOG, HIGH CIRRUS WILL SPREAD OVER ALL TAF SITES THIS MORNING AND
WILL CONTINUE THROUGH THE AFTERNOON AND INTO TONIGHT. MORE FOG IS
POSSIBLE AGAIN TONIGHT, SO HAVE ADDED 3-4SM AT ALL SITES AROUND
MIDNIGHT. WINDS SHOULD BE LIGHT AND VARIABLE THROUGH THE PERIOD AS
HIGH PRESSURE WILL DOMINATE THE AREA NEXT 24HRS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR ILZ044>046-
054>057-061>063-066>068-071>073.
&&
$$
SHORT TERM...07
LONG TERM...07
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
331 AM CDT FRI APR 17 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CDT FRI APR 17 2015
A DENSE FOG ADVISORY ISSUED AROUND 2 AM FOR EASTERN IL WILL BE
ALLOWED TO CONTINUE THROUGH 9 AM CDT. THE PAST HOUR OR TWO THE DENSE
FOG WITH VSBYS 1/4 MILE OR LESS HAS BEEN CONFINED TO AREAS EAST OF I-
57 AND COULD EXPAND FURTHER WEST OF I-57 WITH AREAS OF FOG AND
PATCHY DENSE FOG AS FAR WEST AS I-55 PER HRRR MODEL UNTIL 9 AM. ONCE
THE FOG LIFTS LATER THIS MORNING A NICE MILD SPRING DAY IS SHAPING
UP ACROSS CENTRAL AND SOUTHEAST IL WITH WEAK HIGH PRESSURE OVER IN
AND SOME UPPER LEVEL RIDGING INTO IL GIVING MOSTLY SUNNY SKIES AND
LIGHT WINDS AND MILD HIGHS IN THE MID TO UPPER 70S.
&&
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 331 AM CDT FRI APR 17 2015
DRY CONDITIONS STILL EXPECTED TO CONTINUE ACROSS CENTRAL AND
SOUTHEAST IL THROUGH AT LEAST SAT MORNING WITH JUST ISOLATED SHOWERS
AND THUNDERSTORMS POSSIBLE DURING MID/LATE SAT AFTERNOON ALONG AND
SW OF A GALESBURG TO LINCOLN TO LAWRENCEVILLE LINE. UPPER LEVEL
RIDGE INTO THE OHIO RIVER VALLEY AND IL YET ON SATURDAY TO BRING A
NOTHER MILD SPRING DAY IN THE MID TO UPPER 70S SATURDAY, WITH
MILDEST READINGS NEAR THE IN BORDER WHERE MORE SUNSHINE EXPECTED.
LARGE CUTOFF UPPER LEVEL LOW OVER COLORADO TONIGHT AND SATURDAY GETS
ABSORBED BY NORTHERN STREAM CUTOFF LOW NORTH OF ND/MN SUNDAY AND
MONDAY. WARM AIR ADVECTION SHOWERS AND SCATTERED THUNDERSTORMS TO
SPREAD NE ACROSS CENTRAL AND SOUTHEAST IL DURING SATURDAY NIGHT
ESPECIALLY AFTER MIDNIGHT AND CONTINUE SUNDAY. FAIRLY STRONG SURFACE
LOW PRESSURE EJECTS NE FROM OK PANHANDLE TO NEAR CENTRAL IL BY
SUNSET SUNDAY AND SWEEPS A COLD FRONT EAST THROUGH IL SUNDAY NIGHT.
THIS TO LIKELY BRING MORE SHOWERS AND THUNDERSTORMS SUNDAY AND
SUNDAY NIGHT AND SPC HAS MARGINAL RISK OF SEVERE STORMS SW OF I-74
SUNDAY AFTERNOON INTO EARLY SUNDAY EVENING WITH SLIGHT RISK SW OF A
PITTSFIELD TO EFFINGHAM TO LAWRENCEVILLE LINE FOR LARGE HAIL AND
DAMAGING WIND GUSTS POSSIBLE. HIGHS SUNDAY MOSTLY IN THE LOWER 70S
WITH SOME UPPER 60S NORTH OF I-74.
A LARGE UPPER LEVEL TROF THEN DOMINATES THE MIDWEST MONDAY-THURSDAY
AS STRONG CUTOFF LOW MOVES SLOWLY EAST ACROSS THE NORTHERN GREAT
LAKES REGION. SHOWERS SHOULD DIMINISH TO WIDELY SCATTERED SHOWERS
OVER CENTRAL IL ON MONDAY WITH BEST CHANCES OF SHOWERS OVER IN AND
NORTHERN IL. COOLER HIGHS OF 60-65F MONDAY WITH MILDEST READINGS BY
LAWRENCEVILLE. HAVE DRY AND COOL CONDITIONS MONDAY NIGHT THROUGH TUE
NIGHT. THEN SMALL CHANCES OF SHOWERS WED/THU WITH A WEATHER SYSTEM
APPROACHING FROM THE SW WITH GFS MODEL TRENDING MUCH WETTER DURING
THIS TIME FRAME WHILE ECMWF MODEL IS KEEPING IL DRY. COOL HIGHS IN
THE UPPER 50S/LOWER 60S TUE-WED WITH LOWS IN THE UPPER 30S TO MID
40S, WITH COOLEST READINGS FROM I-74 NORTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1157 PM CDT THU APR 16 2015
AREAS MVFR CONDITIONS WITH LOCAL IFR IN FOG FROM AROUND KCMI-K1H2
EASTWARD THIS EVENING...WITH VFR TO THE WEST AS A SURFACE HIGH
PRESSURE CENTER REMAINS NEAR THE NORTHEAST CORNER OF THE STATE.
FOG WILL SPREAD WESTWARD TO AROUND KBMI-KSPI EASTWARD WHERE
GREATEST AMOUNTS OF LOW LEVEL MOISTURE REMAIN ALONG WITH LIGHT
WINDS AND LACK OF HIGHER LEVEL CLOUD COVER. WITH DAYTIME
HEATING...FOG SHOULD DISSIPATE 13Z-15Z WITH SCATTERED CUMULUS
DEVELOPMENT ABOVE MVFR THRESHOLDS. LIGHT SSE WINDS 5-8 KTS
DEVELOPING IN THE DAYTIME PERIOD...CONTINUING INTO EVENING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR ILZ044>046-
054>057-061>063-066>068-071>073.
&&
$$
SHORT TERM...07
LONG TERM...07
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1157 PM CDT THU APR 16 2015
.UPDATE...
ISSUED AT 901 PM CDT THU APR 16 2015
HIGH PRESSURE OVER THE REGION WILL RESULT IN MINIMAL CLOUD COVER
OVERNIGHT. HOWEVER...FAIRLY HIGH DEWPOINTS MAINLY IN THE 50S WILL
LIKELY PRODUCE AREAS OF FOG AS THE CLEAR SKIES ALLOW GOOD
RADIATIONAL COOLING ALONG WITH LIGHT WINDS ASSOCIATED WITH THE
HIGH. ALREADY HAVE AREAS OF FOG IN FORECAST FROM I-57 CORRIDOR
EASTWARD...WHICH IS IN GOOD AGREEMENT WITH THE LATEST HRRR MODEL.
MAIN UPDATE POSSIBILITY WOULD BE EXTENT OF FOG WESTWARD...AS WELL
AS IF ANY DENSE AREAS DEVELOP. FOR NOW...CURRENT FORECAST LOOKS IN
GOOD SHAPE WITH ONLY UPDATES FOR MINOR TEMPERATURE/CLOUD TRENDS SO
FAR.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 310 PM CDT THU APR 16 2015
HIGH PRESSURE RIDGE SLIDING OFF TO THE EAST AS QUASI ZONAL
FLOW TRANSITIONING TO A SLIGHTLY SOUTHWESTERLY FLOW WITH A DEEP LOW
DIGGING IN AT H5 OVER THE DESERT SW. REMNANT MOISTURE AFFILIATED
WITH WAVE PULLING OFF TO THE EAST STILL IMPACTING THE EASTERN EDGES
OF THE STATE THIS AFTERNOON WITH A MORE PERSISTENT CLOUD COVER.
LIGHT AND VARIABLE WINDS TONIGHT WITH CLEARING SKIES JUST BEFORE
SUNSET SHOULD SET UP A GOOD ENVIRONMENT FOR SOME RADIATIONAL
COOLING. WITH RELATIVELY HIGHER RH IN THE BOUNDARY LAYER TODAY NOT
GETTING MUCH OF A CHANCE FOR MIXING...HAVE PUT FOG IN FOR THE
OVERNIGHT IN THE EAST AND SOUTHEAST. CONCERN THAT IT MAY BE MORE
WIDESPREAD THAN THE CURRENT PLACEMENT WITH THE DWPTS IN THE WEST
STILL NEAR 50.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 PM CDT THU APR 16 2015
FRIDAY WILL FEATURE UPPER LEVEL RIDGING AND WARMING ACROSS ILLINOIS,
AS A CUT-OFF LOW IN THE PLAINS SLOWLY DRIFTS FROM THE FOUR CORNERS
INTO COLORADO. HIGHS WILL REACH INTO THE UPPER 70S IN MANY AREAS
FRIDAY AFTERNOON, UNDER A LIGHT SOUTHEAST WIND.
RAIN AHEAD OF THE CUT-OFF LOW WILL ADVANCE EASTWARD ACROSS THE
PLAINS ON FRIDAY, EXPANDING ACROSS IOWA AND MISSOURI FRIDAY NIGHT
AND SATURDAY. CENTRAL ILLINOIS SHOULD REMAIN DRY THROUGH FRIDAY
NIGHT, WITH A FEW SHOWERS POSSIBLY AFFECTING AREAS SW OF SPI TO
EFFINGHAM ON SATURDAY. INCREASING CLOUDS ON SATURDAY WILL WORK TO
KEEP HIGHS A FEW DEGREES BELOW POTENTIAL HIGHS, BUT WE STILL EXPECT
MID 70S TO PREVAIL FOR HIGHS.
THE LOW WILL BECOME AN OPEN WAVE SATURDAY NIGHT, AS UPPER JET
SUPPORT DEVELOPS IN THE LEE OF THE TROUGH. THAT WILL WORK TO
INCREASE COVERAGE OF SHOWERS AND A FEW THUNDERSTORMS FROM SOUTHWEST
TO NORTHEAST ACROSS CENTRAL ILLINOIS SATURDAY NIGHT. AN INFLUX OF
GULF MOISTURE WILL INCREASE LOW LEVEL INSTABILITY THROUGH THE
WEEKEND. A BETTER CHANCE OF STRONG TO SEVERE STORMS LOOKS TO BE ON
SUNDAY WHEN A SURFACE LOW LIFTS NORTHEAST ACROSS ILLINOIS. THE
PASSAGE OF THE UPPER TROUGH AXIS SUNDAY NIGHT WILL CAUSE
THUNDERSTORM CHANCES TO LINGER AT LEAST THROUGH MIDNIGHT. SPC HAS
WESTERN IL IN THE DAY 4 15 PERCENT SEVERE OUTLOOK, WHICH INCLUDES
12Z SUNDAY TO 12Z MONDAY. WE KEPT LIKELY POPS ACROSS OUR AREA FROM
LATE SATURDAY NIGHT THROUGH SUNDAY NIGHT.
RAINFALL AND PERSISTENT CLOUD COVER SATURDAY NIGHT THROUGH SUNDAY
NIGHT WILL LIMIT DIURNAL TEMP SWINGS. LOWS SAT NIGHT WILL BE IN THE
MID TO UPPER 50S, WITH HIGHS NEAR 70 ON SUNDAY.
A MORE SIGNIFICANT AIRMASS CHANGE IS EXPECTED TO BEGIN SUNDAY NIGHT
BEHIND A DEPARTING SURFACE COLD FRONT. A LONG WAVE TROUGH ALOFT WILL
SETTLE INTO THE HEARTLAND, ALLOWING COOLER CANADIAN AIR TO SETTLE
INTO OUR AREA. LIGHT RAINFALL WILL LINGER ON MONDAY MORNING, MAINLY
EAST OF I-55, BUT CLOUDS SHOULD EVENTUALLY BEGIN TO CLEAR ACROSS
WESTERN IL MONDAY AFTERNOON.
AN EXTENDED PERIOD OF TEMPS AT OR BELOW NORMAL WILL CONTINUE FROM
MONDAY THROUGH AT LEAST WEDNESDAY, AS THE UPPER TROUGH STALLS OVER
THE GREAT LAKES AND NW FLOW DOMINATES ALOFT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1157 PM CDT THU APR 16 2015
AREAS MVFR CONDITIONS WITH LOCAL IFR IN FOG FROM AROUND KCMI-K1H2
EASTWARD THIS EVENING...WITH VFR TO THE WEST AS A SURFACE HIGH
PRESSURE CENTER REMAINS NEAR THE NORTHEAST CORNER OF THE STATE.
FOG WILL SPREAD WESTWARD TO AROUND KBMI-KSPI EASTWARD WHERE
GREATEST AMOUNTS OF LOW LEVEL MOISTURE REMAIN ALONG WITH LIGHT
WINDS AND LACK OF HIGHER LEVEL CLOUD COVER. WITH DAYTIME
HEATING...FOG SHOULD DISSIPATE 13Z-15Z WITH SCATTERED CUMULUS
DEVELOPMENT ABOVE MVFR THRESHOLDS. LIGHT SSE WINDS 5-8 KTS
DEVELOPING IN THE DAYTIME PERIOD...CONTINUING INTO EVENING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ONTON
SHORT TERM...HJS
LONG TERM...SHIMON
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1027 PM EDT SAT APR 18 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 159 PM EDT SAT APR 18 2015
AS HIGH PRESSURE DEPARTS THE AREA TONIGHT...AN ACTIVE WEATHER
PATTERN IS READY TO SET UP AS THE NEW WEEK BEGINS. LOW PRESSURE
OVER LOWER MISSISSIPPI RIVER VALLEY IS EXPECTED TO PUSH ACROSS
INDIANA ON SUNDAY...BRINGING RAIN AND PERHAPS A THUNDERSTORM.
AS THE LOW PUSHES NORTHEAST TO THE GREAT LAKES ON SUNDAY NIGHT...A
BROAD UPPER LEVEL LOW PRESSURE SYSTEM IS SET TO REMAIN IN PLACE
OVER THE GREAT LAKES. WEAK WEATHER DISTURBANCES ALONG WITH COOLER
AIR WILL PUSH ACROSS INDIANA FROM TIME TO TIME THROUGH
TUESDAY...BRINGING DAILY CHANCES FOR SHOWERS AND PERHAPS A
THUNDERSTORM.
COOLER WEATHER IS EXPECTED THROUGH THE END OF THE WORK WEEK AS
NORTHWEST FLOW FROM CANADA IS EXPECTED IN THE WAKE OF THE
DEPARTING LOW.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 1005 PM EDT SAT APR 18 2015
PUSHED OFF ARRIVAL OF PRECIP IN THE SOUTH FOR ANOTHER FEW HOURS PER
RADAR AND HRRR TRENDS. REMAINDER OF FORECAST IN GOOD SHAPE. SHOULD
NOT BE SIGNIFICANT CHANGES TO THE GIST OF THE GOING FORECAST.
PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 159 PM EDT SAT APR 18 2015
SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS HIGH PRESSURE CENTERED
OVER WEST VIRGINIA. LOW PRESSURE HAD DEVELOPED OVER NORTHERN
LOUISIANA. WATER VAPOR CONTINUED TO SHOW AN UPPER LEVEL LOW OVER
COLORADO WITH A STREAM OF TROPICAL MOISTURE AHEAD OF THIS
SYSTEM...STREAMING NORTH THROUGH THE MISSISSIPPI AND INTO THE OHIO
VALLEY. DEW POINT TEMPS ACROSS CENTRAL INDIANA REMAINED IN THE DRY
40S...WHILE MORE MOIST AIR WITH DEW POINTS IN THE 60S WAS NOT FAR
AWAY OVER WESTERN KENTUCKY.
MAIN FORECAST CHALLENGE TONIGHT WILL BE POPS AND TEMPS.
MUCH OF THIS FORECAST PERIOD WILL BE DRY AS BEST FORCING
ASSOCIATED WITH THE APPROACHING LOW PRESSURE SYSTEM FROM THE
SOUTHWEST FAILS TO ARRIVE UNTIL AFTER 06Z. DRY AIR REMAINS IN
PLACE ACROSS THE REGION THROUGH THE EVENING. 300K GFS ISENTROPIC
SURFACE SHOWS GOOD UPGLIDE AND A SURGE OF SPECIFIC HUMIDITIES IN
EXCESS OF 7 G/KG NEAR 12Z...WITH AN EVEN BETTER SURGE AFTER 12Z
SUNDAY.; FORECAST SOUNDINGS SHOW INCREASING SATURATION BY
12Z...WITH BEST SATURATION ACROSS THE SOUTHERN AREA WHERE MOISTURE
IS EXPECTED FIRST. WITH EXCELLENT FORCING EXPECTED AS WITH THE
ARRIVAL OF UPPER DYNAMICS...WILL TREND POPS HIGHER ACROSS THE
SOUTHWEST WHERE MOIST SHOULD ARRIVE PRIOR TO 12Z...BUT STICK CLOSE
TO GUIDANCE ELSEWHERE. THE EVENING SHOULD REMAIN DRY.
GIVEN THE EXPECTED CLOUDS AND PRECIP WILL TREND LOWS AT OR ABOVE
MAVMOS.
&&
.SHORT TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 159 PM EDT SAT APR 18 2015
A WET DAY IS A GIVEN ON SUNDAY. GFS AND NAM BOTH SHOW DEEPLY
SATURATED COLUMNS ON SUNDAY THROUGH THE MIDDLE OF THE DAY AS
STRONG FORCING WORKS ACROSS THE AREA ASSOCIATED WITH THE PASSING
SURFACE LOW. AS STATED ABOVE...THE GFS 300K ISENTROPIC SURFACE
SHOWS EXCELLENT UPGLIDE ALONG WITH VERY MOIST SPECIFIC HUMIDITIES
IN EXCESS OF 7 G/KG. THUS WILL USE 100 POPS ON SUNDAY...ALONG WITH
TEMPS COOLER THAN MAVMOS GIVEN THE EXPECTED CLOUDS AND RAIN.
GFS AND NAM SHOW THE FIRST WAVE OF FORCING DEPARTING THE AREA
AFTER 00Z...HOWEVER BROAD CYCLONIC UPPER FLOW APPEARS TO DEVELOP
AS THE UPPER LOW REACHES THE GREAT LAKES AND BEGINS TO MERGE AND
DEEPEN WITH ANOTHER UPPER LOW SINKING OUT OF NORTHERN CANADA. AN
ADDITIONAL SHORT WAVE EMBEDDED WITH THE FLOW LOOKS TO PASS ACROSS
CENTRAL INDIANA ON SUNDAY NIGHT AND INTO MONDAY. AGAIN GOOD
MOISTURE AND FORCING APPEARS IN PLACE. FORECAST SOUNDINGS SHOW
DEEP SATURATION AGAIN ON MONDAY MORNING AS THIS WAVE PASSES. THUS
WILL AGAIN TREND POPS HIGHER ON ON LATE SUNDAY NIGHT AND AGAIN ON
MONDAY. GIVEN THE EXPECTED CLOUDS AND COLD AIR ADVECTION AND
POSSIBLE RAIN SHOWERS WILL TREND LOWS WARMER THAN MAVMOS AND HIGHS
COOLER.
A BRIEF BREAK APPEARS ON MONDAY NIGHT AS THE PREVIOUS SECOND
SHORT WAVE DEPARTS ACROSS THE AREA AND SOME SUBSIDENCE IS SEEN
WITHIN THE BROAD CYCLONIC FLOW. GOOD MID LEVEL DRY AIR IS SEEN AS
WELL AS WITHIN FORECAST SOUNDINGS. WILL TREND TOWARD A DRIER FORECAST
ON MONDAY NIGHT...WITH LOWS AT OR BELOW MAVMOS.
NAM AND GFS BOTH SUGGEST A WEAKER AND POORLY DEFINED SHORT WAVE
PUSHES INTO THE AREA LATE ON TUESDAY. BEST FORCING APPEARS TO BE
ACROSS THE SOUTHERN PARTS OF THE FORECAST AREA. FORECAST SOUNDINGS
CONTINUE TO SHOW A RATHER DRY COLUMN WITH CONVECTIVE TEMPS
REACHABLE IN THE LOWER 50S. HOWEVER PLENTY OF DRY AIR ALOFT WILL
HAMPER SHOWER DEVELOPMENT. OVERALL CONFIDENCE IS LOW FOR THAT
TIME. THUS WILL TREND TO POPS AT OR BELOW MEXMOS...AND STICK CLOSE
ON HIGHS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 215 PM EDT SAT APR 18 2015
MODELS IN GENERAL AGREEMENT THAT THE EXTENDED WILL BE COOL WITH THE
POTENTIAL FOR A FEW SHOWERS MAINLY TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT AND AGAIN NEXT WEEKEND. WITH GOOD MODEL AGREEMENT...MADE
LITTLE CHANGES TO REGIONAL BLEND POPS. 5400 METER 1000-500 MILLIBAR
THICKNESS LINE ACROSS THE AREA THROUGH THE PERIOD STRONGLY SUPPORTS
THE BELOW NORMAL BLEND TEMPERATURES WITH AFTERNOON HIGHS IN THE MID
50S TO LOWER 60S AND LOWS IN THE MID 30S TO LOWER 40S.
&&
.AVIATION /DISCUSSION FOR 190300Z TAF ISSUANCE/...
ISSUED AT 1027 PM EDT SAT APR 18 2015
HI RES MODELS HAVE COME IN LINE AND ARE SLOWING DOWN ARRIVAL OF
PRECIP SO PUSHED BACK TIMING AT THE SITES BY A COUPLE HOURS WITH THE
UPDATE. PREVIOUS DISCUSSION FOLLOWS...
VFR TO START THE PERIOD WITH WINDS OF 5-10 KTS GENERALLY OUT OF THE
EAST. A SURFACE LOW WILL MOVE UP THE MISSISSIPPI AND THROUGH WESTERN
INDIANA BRINGING RAIN AND IFR CONDITIONS TO THE SITES. THIS SHOULD
START IN THE SOUTHERN SITES SOMETIME AFTER AROUND 11Z AND SPREAD
NORTH FROM THERE. THE LATEST NAM RUN SHOWS THINGS A BIT SLOWER AND
SREFS ARE LEANING THAT WAY AS WELL BUT THE HIGH RES MODELS ARE NOT
ON BOARD. FOR NOW SLOWED THE TIMING OF ARRIVAL SLIGHTLY TO A MORE
AVERAGE SOLUTION. WIND SPEEDS WILL INCREASE AS THE PRESSURE
GRADIENT ACROSS THE AREA INCREASES LATER TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...PUMA/NIELD
SHORT TERM...PUMA
LONG TERM...MK
AVIATION...CP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1005 PM EDT SAT APR 18 2015
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 159 PM EDT SAT APR 18 2015
AS HIGH PRESSURE DEPARTS THE AREA TONIGHT...AN ACTIVE WEATHER
PATTERN IS READY TO SET UP AS THE NEW WEEK BEGINS. LOW PRESSURE
OVER LOWER MISSISSIPPI RIVER VALLEY IS EXPECTED TO PUSH ACROSS
INDIANA ON SUNDAY...BRINGING RAIN AND PERHAPS A THUNDERSTORM.
AS THE LOW PUSHES NORTHEAST TO THE GREAT LAKES ON SUNDAY NIGHT...A
BROAD UPPER LEVEL LOW PRESSURE SYSTEM IS SET TO REMAIN IN PLACE
OVER THE GREAT LAKES. WEAK WEATHER DISTURBANCES ALONG WITH COOLER
AIR WILL PUSH ACROSS INDIANA FROM TIME TO TIME THROUGH
TUESDAY...BRINGING DAILY CHANCES FOR SHOWERS AND PERHAPS A
THUNDERSTORM.
COOLER WEATHER IS EXPECTED THROUGH THE END OF THE WORK WEEK AS
NORTHWEST FLOW FROM CANADA IS EXPECTED IN THE WAKE OF THE
DEPARTING LOW.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 1005 PM EDT SAT APR 18 2015
PUSHED OFF ARRIVAL OF PRECIP IN THE SOUTH FOR ANOTHER FEW HOURS PER
RADAR AND HRRR TRENDS. REMAINDER OF FORECAST IN GOOD SHAPE. SHOULD
NOT BE SIGNIFICANT CHANGES TO THE GIST OF THE GOING FORECAST.
PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 159 PM EDT SAT APR 18 2015
SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS HIGH PRESSURE CENTERED
OVER WEST VIRGINIA. LOW PRESSURE HAD DEVELOPED OVER NORTHERN
LOUISIANA. WATER VAPOR CONTINUED TO SHOW AN UPPER LEVEL LOW OVER
COLORADO WITH A STREAM OF TROPICAL MOISTURE AHEAD OF THIS
SYSTEM...STREAMING NORTH THROUGH THE MISSISSIPPI AND INTO THE OHIO
VALLEY. DEW POINT TEMPS ACROSS CENTRAL INDIANA REMAINED IN THE DRY
40S...WHILE MORE MOIST AIR WITH DEW POINTS IN THE 60S WAS NOT FAR
AWAY OVER WESTERN KENTUCKY.
MAIN FORECAST CHALLENGE TONIGHT WILL BE POPS AND TEMPS.
MUCH OF THIS FORECAST PERIOD WILL BE DRY AS BEST FORCING
ASSOCIATED WITH THE APPROACHING LOW PRESSURE SYSTEM FROM THE
SOUTHWEST FAILS TO ARRIVE UNTIL AFTER 06Z. DRY AIR REMAINS IN
PLACE ACROSS THE REGION THROUGH THE EVENING. 300K GFS ISENTROPIC
SURFACE SHOWS GOOD UPGLIDE AND A SURGE OF SPECIFIC HUMIDITIES IN
EXCESS OF 7 G/KG NEAR 12Z...WITH AN EVEN BETTER SURGE AFTER 12Z
SUNDAY.; FORECAST SOUNDINGS SHOW INCREASING SATURATION BY
12Z...WITH BEST SATURATION ACROSS THE SOUTHERN AREA WHERE MOISTURE
IS EXPECTED FIRST. WITH EXCELLENT FORCING EXPECTED AS WITH THE
ARRIVAL OF UPPER DYNAMICS...WILL TREND POPS HIGHER ACROSS THE
SOUTHWEST WHERE MOIST SHOULD ARRIVE PRIOR TO 12Z...BUT STICK CLOSE
TO GUIDANCE ELSEWHERE. THE EVENING SHOULD REMAIN DRY.
GIVEN THE EXPECTED CLOUDS AND PRECIP WILL TREND LOWS AT OR ABOVE
MAVMOS.
&&
.SHORT TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 159 PM EDT SAT APR 18 2015
A WET DAY IS A GIVEN ON SUNDAY. GFS AND NAM BOTH SHOW DEEPLY
SATURATED COLUMNS ON SUNDAY THROUGH THE MIDDLE OF THE DAY AS
STRONG FORCING WORKS ACROSS THE AREA ASSOCIATED WITH THE PASSING
SURFACE LOW. AS STATED ABOVE...THE GFS 300K ISENTROPIC SURFACE
SHOWS EXCELLENT UPGLIDE ALONG WITH VERY MOIST SPECIFIC HUMIDITIES
IN EXCESS OF 7 G/KG. THUS WILL USE 100 POPS ON SUNDAY...ALONG WITH
TEMPS COOLER THAN MAVMOS GIVEN THE EXPECTED CLOUDS AND RAIN.
GFS AND NAM SHOW THE FIRST WAVE OF FORCING DEPARTING THE AREA
AFTER 00Z...HOWEVER BROAD CYCLONIC UPPER FLOW APPEARS TO DEVELOP
AS THE UPPER LOW REACHES THE GREAT LAKES AND BEGINS TO MERGE AND
DEEPEN WITH ANOTHER UPPER LOW SINKING OUT OF NORTHERN CANADA. AN
ADDITIONAL SHORT WAVE EMBEDDED WITH THE FLOW LOOKS TO PASS ACROSS
CENTRAL INDIANA ON SUNDAY NIGHT AND INTO MONDAY. AGAIN GOOD
MOISTURE AND FORCING APPEARS IN PLACE. FORECAST SOUNDINGS SHOW
DEEP SATURATION AGAIN ON MONDAY MORNING AS THIS WAVE PASSES. THUS
WILL AGAIN TREND POPS HIGHER ON ON LATE SUNDAY NIGHT AND AGAIN ON
MONDAY. GIVEN THE EXPECTED CLOUDS AND COLD AIR ADVECTION AND
POSSIBLE RAIN SHOWERS WILL TREND LOWS WARMER THAN MAVMOS AND HIGHS
COOLER.
A BRIEF BREAK APPEARS ON MONDAY NIGHT AS THE PREVIOUS SECOND
SHORT WAVE DEPARTS ACROSS THE AREA AND SOME SUBSIDENCE IS SEEN
WITHIN THE BROAD CYCLONIC FLOW. GOOD MID LEVEL DRY AIR IS SEEN AS
WELL AS WITHIN FORECAST SOUNDINGS. WILL TREND TOWARD A DRIER FORECAST
ON MONDAY NIGHT...WITH LOWS AT OR BELOW MAVMOS.
NAM AND GFS BOTH SUGGEST A WEAKER AND POORLY DEFINED SHORT WAVE
PUSHES INTO THE AREA LATE ON TUESDAY. BEST FORCING APPEARS TO BE
ACROSS THE SOUTHERN PARTS OF THE FORECAST AREA. FORECAST SOUNDINGS
CONTINUE TO SHOW A RATHER DRY COLUMN WITH CONVECTIVE TEMPS
REACHABLE IN THE LOWER 50S. HOWEVER PLENTY OF DRY AIR ALOFT WILL
HAMPER SHOWER DEVELOPMENT. OVERALL CONFIDENCE IS LOW FOR THAT
TIME. THUS WILL TREND TO POPS AT OR BELOW MEXMOS...AND STICK CLOSE
ON HIGHS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 215 PM EDT SAT APR 18 2015
MODELS IN GENERAL AGREEMENT THAT THE EXTENDED WILL BE COOL WITH THE
POTENTIAL FOR A FEW SHOWERS MAINLY TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT AND AGAIN NEXT WEEKEND. WITH GOOD MODEL AGREEMENT...MADE
LITTLE CHANGES TO REGIONAL BLEND POPS. 5400 METER 1000-500 MILLIBAR
THICKNESS LINE ACROSS THE AREA THROUGH THE PERIOD STRONGLY SUPPORTS
THE BELOW NORMAL BLEND TEMPERATURES WITH AFTERNOON HIGHS IN THE MID
50S TO LOWER 60S AND LOWS IN THE MID 30S TO LOWER 40S.
&&
.AVIATION /DISCUSSION FOR 190000Z TAF ISSUANCE/...
ISSUED AT 721 PM EDT SAT APR 18 2015
VFR TO START THE PERIOD WITH WINDS OF 5-10 KTS GENERALLY OUT OF THE
EAST. A SURFACE LOW WILL MOVE UP THE MISSISSIPPI AND THROUGH WESTERN
INDIANA BRINGING RAIN AND IFR CONDITIONS TO THE SITES. THIS SHOULD
START IN THE SOUTHERN SITES SOMETIME AFTER AROUND 11Z AND SPREAD
NORTH FROM THERE. THE LATEST NAM RUN SHOWS THINGS A BIT SLOWER AND
SREFS ARE LEANING THAT WAY AS WELL BUT THE HIGH RES MODELS ARE NOT
ON BOARD. FOR NOW SLOWED THE TIMING OF ARRIVAL SLIGHTLY TO A MORE
AVERAGE SOLUTION. WIND SPEEDS WILL INCREASE AS THE PRESSURE
GRADIENT ACROSS THE AREA INCREASES LATER TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...PUMA/NIELD
SHORT TERM...PUMA
LONG TERM...MK
AVIATION...CP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS DODGE CITY KS
618 PM CDT SAT APR 18 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 222 PM CDT SAT APR 18 2015
ABBREVIATED SHORT TERM DUE TO CONVECTION ALREADY IN PROGRESS. THE GENERAL
STORY THIS AFTERNOON AND EVENING IS ANOTHER ROUND OF SEVERE WEATHER.
THINK THE MOST LIKEST PLACE (IN ADDITION TO WHAT IS OCCURRING NOW),
IS ALONG AND EAST OF A DRYLINE. THIS EXTENDS ROUGHLY FROM TREGO COUNTY,
JUST EAST OF DODGE CITY, AND DOWN TO EAST CENTRAL CLARK COUNTY. INSTABILITY
AND BULK SHEAR ARE SUPPORTIVE OF ORGANIZED THUNDERSTORMS. MESOSCALE
GUIDANCE SUGGESTS SOME SUPERCELLS ARE POSSIBLE EARLY IN THE EVENT AND
THEN STORM TYPE EVOLVING INTO A LINE ACROSS SOUTH CENTRAL KANSAS BY
MID EVENING. INITIALLY, IT WILL BE A LARGE HAIL EVENT WITH THE LHP FORECAST
HAIL SIZE OF AROUND 2". THIS SHOULD BE THE MAX SIZE. UPPER LEVEL WINDS
BACK WITH HEIGHT WITH TIME, SO THINK BENEFICIAL COMPETITION WILL INCREASE
AS TIME GOES FORWARD...HENCE, HAIL SIZE GROWTH POTENTIAL WILL BE SOMEWHAT
MITIGATED. FOR A TORNADO CONCERN, LOW LEVEL SHEAR IS ON THE WEAK SIDE.
THERE IS A SLIGHT WINDOW ACROSS BARBER, COMANCHE, AND PRATT COUNTIES,
WHERE THIS IMPROVES THIS EVENING. HOWEVER, THINK ACTIVITY WON`T BE
AS DISCRETE BY THAT TIME. THE MAIN THREAT WOULD THEN EVOLVE INTO A CONVECTIVE
WIND OUTFLOW CONCERN. BOTTOM LINE, THE OVERALL ENVIRONMENT IS JUST NOT
THAT CONDUCIVE FOR TORNADOES, EXCEPT IN THE ABOVE MENTIONED AREA ACROSS
SOUTH-CENTRAL KANSAS AND ONLY FOR A SMALL WINDOW. OTHERWISE, SEVERE
ACTIVITY WILL BE OUT OF THE REGION BY 03Z OR SO. A DEFORMATION BAND
IS FORECAST BEHIND THE MID TO LOW LEVEL PRESSURE PERTURBATION AND THINK
SHOWERS AND ISOLATED THUNDERSTORMS IN ITS WAKE. THE MESOSCALE MODELS
SHOW DECENT QPF WITH THIS ACTIVITY, SO OUR WESTERN AND NORTHWESTERN
COUNTIES MIGHT SEE ADDITIONAL RAINFALL.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 245 PM CDT SAT APR 18 2015
MEDIUM RANGE MODELS INDICATE A BROAD UPPER LEVEL TROUGH OF LOW
PRESSURE TRANSITIONING SLOWLY EASTWARD ACROSS THE NORTHERN AND
CENTRAL PLAINS EARLY IN THE WEEK SETTING UP GENERAL WESTERLY FLOW
ALOFT ACROSS THE WESTERN HIGH PLAINS. MEANWHILE, A WEAK UPPER LEVEL
RIDGE OF HIGH PRESSURE WILL PUSH ASHORE INTO THE PACIFIC NORTHWEST.
ALONG WITH A WEAKER FLOW ALOFT AND DRIER AIR PRESENT IN THE
LOWER/MID LEVELS, PRECIP CHANCES WILL REMAIN ABSENT ACROSS MUCH OF
WESTERN KANSAS THROUGH MONDAY EVENING. HOWEVER, THERE IS AN OUTSIDE
CHANCE FOR THUNDERSTORMS ACROSS EXTREME SOUTHWESTERN KANSAS LATE
MONDAY NIGHT AS INCREASED MOISTURE ASSOCIATED WITH A SERIES OF H5
VORT MAXIMA BEGINS TO MOVE OFF THE COLORADO ROCKIES SOUTHEASTWARD
INTO THE HIGH PLAINS. HELPING SET THE STAGE FOR INCREASING PRECIP
CHANCES WILL BE SURFACE HIGH PRESSURE MOVING SOUTHEAST OUT OF
KANSAS INTO THE LOWER MISSISSIPPI RIVER VALLEY, BRINGING ABOUT A
SOUTHEASTERLY UPSLOPE FLOW FROM THE SOUTH PLAINS UP INTO THE
OKLAHOMA PANHANDLE AND SOUTHWEST KANSAS. BECAUSE OF DRIER AIR
REMAINING IN THE LOWER/MID LEVELS, ANY STORM DEVELOPMENT IS LIKELY
TO BE ISOLATED AND HIGH BASED. PRECIP CHANCES RETURN IN EARNEST
MID TO LATE WEEK AS AN UPPER LEVEL SHORTWAVE PUSHING ASHORE INTO
SOUTHERN CALIFORNIA EARLY IN THE WEEK MOVES FURTHER EAST INTO THE
DESERT SOUTHWEST.
COOLER AND BELOW NORMAL TEMPERATURES ARE TO BE EXPECTED MONDAY IN
WAKE OF A COLD FRONTAL PASSAGE ON SUNDAY. COOLER AIR WILL FILTER
SOUTHWARD INTO WESTERN KANSAS WITH H85 TEMPERATURES DOWN INTO THE
MID SINGLE DIGITS(C) ACROSS CENTRAL AND SOUTHWEST KANSAS. WITH THE
HELP OF A NORTHWESTERLY DOWNSLOPE FLOW, HIGHS MAY REACH THE LOWER TO
MID 60S(F) MONDAY AFTERNOON. HIGHS ARE EXPECTED TO CLIMB WELL INTO
THE 60S(F) TUESDAY WITH A SLIGHT WARM UP TO THE AIR MASS ACROSS THE
HIGH PLAINS. THE GENERAL WARMING TREND IS LIKELY TO CONTINUE THROUGH
WEDNESDAY AS THE GENERAL FLOW NEAR THE SURFACE BECOMES MORE SOUTHERLY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 614 PM CDT SAT APR 18 2015
VFR CONDITIONS CAN BE EXPECTED OVERNIGHT. WESTERLY WINDS AT 10 TO
15 KNOTS WILL DEVELOP EARLY TONIGHT AS A SURFACE BOUNDARY MOVES
FROM WESTERN KANSAS INTO CENTRAL KANSAS THROUGH 06Z SUNDAY. WINDS
JUST BEHIND THIS BOUNDARY GUSTY NORTHWEST WINDS WILL BRIEFLY
DEVELOP. EVENING CONVECTION EAST OF DDC AND HYS IS ALSO EXPECTED
TO TAPER OFF FROM WEST TO EAST AS AN UPPER LEVEL DISTURBANCE
CROSSES WESTERN KANSAS. AS THE WINDS VEER MORE TO THE NORTHWEST
TOWARDS 12Z SUNDAY THE LOWER LEVELS WILL BEGIN TO SATURATE. BASED
ON THE HRRR AND RAP ALONG WITH THE BUFR SOUNDINGS SOME MVFR OR IFR
STATUS WILL BE POSSIBLE EARLY SUNDAY MORNING AFTER 12Z SUNDAY.
NORTHWESTERLY WINDS WILL ALSO BE ON THE INCREASE EARLY SUNDAY AND
BY 18Z SUNDAY WIND SPEEDS OF AT LEAST 25 KNOTS WILL BE LIKELY AT
ALL THREE TAF SITES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 59 36 61 / 50 70 10 10
GCK 43 56 34 60 / 50 70 10 10
EHA 41 57 36 61 / 30 30 10 20
LBL 43 58 37 61 / 30 40 10 10
HYS 49 58 34 61 / 70 70 0 10
P28 51 67 38 63 / 70 70 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SUGDEN
LONG TERM...JJOHNSON
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS TOPEKA KS
349 PM CDT Fri Apr 17 2015
.SHORT TERM...(This Evening through Saturday)
Issued at 346 PM CDT FRI APR 17 2015
Upper low continues to spin over the Rockies this afternoon with an
upper level jet rounding the base of the upper low and moving over
New Mexico. Earlier showers and thunderstorms were moving out of the
northern counties at 20Z. Some clearing was occurring across the
southern and western sections of the cwa this afternoon. Latest meso
analysis shows surface based CAPE around 500 to 1000 J/kg with an
uncapped atmosphere. Expect scattered convection to develop in
southwest Kansas along the dry line. additional scattered storms may
develop in south west and south central Kansas per the latest runs
of the RAP and HRRR. Models suggest additional development this
evening across western and central Kansas moving northeast into
north central Kansas with the increase and veering of the low level
jet overnight. Models are in agreement with a lobe of energy working
it`s way northeast out of Oklahoma later tonight and Saturday
morning. May see a repeat of this morning with an area of showers
and embedded thunderstorms moving across the area. Expect a break
for a few hours in the afternoon, then chances increase again with
storms developing again in the afternoon in western and central
Kansas as upward vertical motion increases with the advance of the
upper trough into the High Plains. Dryline looks to set up across
western Kansas with the GFS the furthest east in central Kansas.
Shear and instability will be favorable for some of the storms to be
strong to severe with large hail and winds the main hazards in the
late afternoon hours mainly west of a Herington to Washington
line.
.LONG TERM...(Saturday Night through Friday)
Issued at 346 PM CDT FRI APR 17 2015
Short range models are relatively consistent in moving surface low
and main piece of upper trough through eastern KS late Saturday
night and Sunday. Ahead of this system Saturday night, increasing
thunderstorm chances are expected, with some potential for severe
weather, with the best chance in our forecast area over the western
2/3. Shear parameters are not very impressive and amount of
sunshine and associated surface heating Sat afternoon and evening is
also a little suspect so this is not a high probability thing.
As the low and front move through on Sunday, some isolated thunder
may continue in the east in the morning, but showers associated with
cold air aloft just behind the front will continue precip chances
into the afternoon hours.
After that, subsidence and cold advection behind that system brings
in dry conditions and cooler temperatures for Sunday night through
Tuesday, with lows dipping into the upper 30s many places and highs
in the low to mid 60s.
Precip chances return to parts of eastern KS on Wednesday when weak
low-level warm advection and a weak wave in northwest flow aloft
interact. Latest ECMWF and GEM would indicate that the cool air at
the surface is more entrenched in place than the GFS, thus have
gone cooler than guidance for highs on Wednesday.
Beyond Wednesday, considerable differences exist between 12Z GFS and
ECMWF in upper flow pattern and precip chances. GFS and GFSEnsemble
places us in a more favorable pattern for a couple days of precip
for Thursday and Friday, while the ECMWF is slower in bringing a
shortwave trough out of the southwest U.S., and would give us the
better chances on Friday. Have gone with a general compromise
with 25 to 40 percent POPs for those days.
&&
.AVIATION...(For the 18Z TAFs through 18Z Saturday Afternoon)
Issued at 105 PM CDT FRI APR 17 2015
VFR conditions are expected through the period outside of
convection. Expect isolated tsra this afternoon and evening then a
better chance of more widespread shra and isolated tsra after 08Z
through the end of the period. MVFR vsbys are expected along with
brief reductions of cigs into the mvfr category. Winds remain east
southeast through the period generally less than 10 kts.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...GDP
AVIATION...53
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
335 AM CDT FRI APR 17 2015
...UPDATED FOR LONG TERM...
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 120 PM CDT THU APR 16 2015
IN THE SHORT TERM, A FEW (2-3) ROUNDS OF CONVECTION ARE ANTICIPATED
THROUGH HE NEXT 24 TO 36 HOURS OR SO AS A LARGE UPPER LOW MOVES
TOWARD THE REGION WITH FORCING FOR ASCENT, AND PERSISTENT MID LEVEL
MOISTURE ADVECTION TO MAINTAIN INSTABILITY FOR A PROLONGED PERIOD.
THE FIRST ROUNDS ARE EXPECTED ALREADY EARLY THIS AFTERNOON AS THE
NESTED 4 KM NAM AND HRRR MODELS HAVE GENERALLY AGREED ON CONVECTIVE
INITIATION BETWEEN AROUND 2 AND 4 PM, AND RAPIDLY DEVELOPING INTO A
MULTICELLULAR LINE AFTER AN HOUR OR SO OF SLOWER GROWING DISCREET
CELLS. THE INITIAL ROTATING STORMS GENERALLY WEST OF HIGHWAY 83
SHOULD BE CAPABLE OF PRODUCING HAIL LARGER THAN GOLFBALLS AND
DAMAGING WIND BEFORE THE STORMS BECOME MORE CLUSTERED OR LINEAR,
PRESENTING A SLIGHTLY SMALLER HAIL THREAT AND STILL DAMAGING WIND
THREAT THROUGH THE HIGHWAY 283 AND 183 CORRIDORS INTO THE EARLY
EVENING HOURS. THESE MODEL SOLUTIONS COULD BE INTERFERED WITH BY THE
EXTENSIVE STRATUS ACROSS THE AREA REDUCING THE SEVERE THREAT.
ANOTHER ROUND OF THUNDERSTORMS WILL PROBABLY OCCUR LATE TONIGHT INTO
THE OVERNIGHT AND POSSIBLY STILL ONGOING EARLY FRIDAY MORNING, WITH
A CONTINUED HAIL IF NOT AN ISOLATED WIND THREAT AS WELL, ALTHOUGH
SOME BL STABILITY SHOULD HINDER THE WIND THREAT. THE DYNAMICS OF THE
UPPER LOW WILL DRIVE A DRY SLOT THROUGH THE REGION OF FRIDAY, BUT
NOT BEFORE LATE MORNING/EARLY AFTERNOON DESTABILIZATION CONTRIBUTES
TO YET ANOTHER SEVERE EPISODE WITH AS GOOD OR BETTER CAPE AND SHEAR
COMBINATIONS.
TEMPERATURES WERE RAISED FOR FRIDAY MORNING, FOLLOWING THE NAM AND
GFS, AS OVERNIGHT CONVECTION SHOULD LIMIT THE RADIATIONAL COOLING.
ADDITIONALLY THE POPS WERE RAISED LOWERED FRIDAY MORNING AND
INCREASED ALONG THE MOISTURE TRANSPORT AXIS INTO FRIDAY AFTERNOON
WITH A MODEL CONSENSUS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 334 AM CDT FRI APR 17 2015
FOR SATURDAY, THE UPPER LOW IS FORECAST TO MOVE FROM CENTRAL
COLORADO AND INTO EASTERN COLORADO BY EVENING. A DRYLINE IS FORECAST
TO PUSH TOWARDS DODGE CITY BY LATE AFTERNOON AND EVENING. THE NAM
MODEL KEEPS THE DRYLINE FARTHER WEST, WHILE THE GFS PUSHES IT WELL
EAST INTO PARTS OF SOUTH CENTRAL KANSAS. TYPICALLY MODELS PUSH THE
DRYLINE MORE EAST THAN WHAT ACTUAL HAPPENS SO WILL GO WITH THE NAM
FOR NOW THAT AGREES WITH SPC SEVERE SLIGHT RISK FORECAST. CAPES ARE
FORECAST TO RUN FROM 1500-2000 J/KG. SOME NEGATIVES FOR WIDESPREAD
SEVERE ARE WEAKNESS IN THE MID AND UPPER LEVEL WINDS. SOME SEVERE
THUNDERSTORMS ARE POSSIBLE ALONG AND EAST OF THE DRYLINE BY
AFTERNOON INTO THE EVENING WITH LARGE HAIL FROM QUARTER TO GOLFBALL
WITH THE MID LEVELS FAIRLY COLD AROUND -17 CELSIUS. HIGHS ON
SATURDAY WILL RANGE FROM THE UPPER 60S FAR WEST TO THE MID 70 OVER
SOUTH CENTRAL SECTIONS OF KANSAS. FOR SATURDAY NIGHT WILL CONTINUE
WITH A CHANCE OR SHOWERS AND ISOLATED THUNDERSTORMS WITH OVERNIGHT
LOWS IN THE MID AND UPPER 40S.
FOR SUNDAY, THE UPPER LOW AND TROUGH MOVES INTO EASTERN KANSAS WITH
ONLY SOME LEFT OVER RAIN SHOWERS MAINLY NORTH AND EAST OF DODGE CITY
AS A COLD FRONT MOVES ACROSS WESTERN KANSAS. THUNDERSTORMS ARE ALSO
POSSIBLE IN THE PARTS OF SOUTH CENTRAL KANSAS WITH BETTER
INSTABILITY FROM PRATT AND COLDWATER AND SOUTH. HIGHS ON SUNDAY WILL
BE IN THE LOW TO MID 60S. LOWS SUNDAY NIGHT WILL RANGE FROM THE MID
30 NORTH AROUND THE I-70 CORRIDOR TO UPPER 30S AND LOW 40S SOUTH
FROM DODGE CITY TO THE OKLAHOMA BORDER.
FOR THE PERIOD OF MONDAY INTO THURSDAY, SOME DISTURBANCES IN
NORTHWESTERLY FLOW COULD BRING SOME SMALL CHANCES FOR RAIN SHOWERS
AND OR THUNDERSTORMS, WITH THE BEST CHANCES TOWARDS WEDNESDAY INTO
THURSDAY AS GULF MOISTURE RETURNS. HIGH TEMPS WILL RUN IN THE 60S
MONDAY AND TUESDAY, AND AROUND 70 ON WEDNESDAY AND THURSDAY. LOWS
WILL RANGE FROM THE UPPER 30S TUESDAY MORNING, THEN INTO THE 40S
INTO THURSDAY MORNING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1256 AM CDT FRI APR 17 2015
AREAS OF RAIN AND THUNDERSTORMS WILL AFFECT THE TAF SITES
PERIODICALLY THROUGH THE PERIOD. MUCH OF THE TIME, VFR CONDITIONS
WILL PERSIST, WITH SOUTHEAST WINDS AT 10 TO 15 KTS OUTSIDE OF
THUNDERSTORMS. VISIBILITIES MAY DROP TO MVFR IN ANY THUNDERSTORMS
WITH CEILINGS REMAINING VFR/MVFR, EXCEPT FOR IN ANY HEAVIER
SHOWERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 71 52 72 46 / 60 60 40 50
GCK 71 48 69 45 / 50 50 30 40
EHA 71 42 68 44 / 10 20 20 30
LBL 71 46 71 46 / 30 40 30 30
HYS 70 56 72 49 / 70 70 50 50
P28 71 56 75 51 / 70 70 40 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 8 PM CDT THIS
EVENING FOR KSZ084.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...KRUSE
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1259 AM CDT FRI APR 17 2015
...UPDATED FOR AVIATION DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 120 PM CDT THU APR 16 2015
IN THE SHORT TERM, A FEW (2-3) ROUNDS OF CONVECTION ARE ANTICIPATED
THROUGH HE NEXT 24 TO 36 HOURS OR SO AS A LARGE UPPER LOW MOVES
TOWARD THE REGION WITH FORCING FOR ASCENT, AND PERSISTENT MID LEVEL
MOISTURE ADVECTION TO MAINTAIN INSTABILITY FOR A PROLONGED PERIOD.
THE FIRST ROUNDS ARE EXPECTED ALREADY EARLY THIS AFTERNOON AS THE
NESTED 4 KM NAM AND HRRR MODELS HAVE GENERALLY AGREED ON CONVECTIVE
INITIATION BETWEEN AROUND 2 AND 4 PM, AND RAPIDLY DEVELOPING INTO A
MULTICELLULAR LINE AFTER AN HOUR OR SO OF SLOWER GROWING DISCREET
CELLS. THE INITIAL ROTATING STORMS GENERALLY WEST OF HIGHWAY 83
SHOULD BE CAPABLE OF PRODUCING HAIL LARGER THAN GOLFBALLS AND
DAMAGING WIND BEFORE THE STORMS BECOME MORE CLUSTERED OR LINEAR,
PRESENTING A SLIGHTLY SMALLER HAIL THREAT AND STILL DAMAGING WIND
THREAT THROUGH THE HIGHWAY 283 AND 183 CORRIDORS INTO THE EARLY
EVENING HOURS. THESE MODEL SOLUTIONS COULD BE INTERFERED WITH BY THE
EXTENSIVE STRATUS ACROSS THE AREA REDUCING THE SEVERE THREAT.
ANOTHER ROUND OF THUNDERSTORMS WILL PROBABLY OCCUR LATE TONIGHT INTO
THE OVERNIGHT AND POSSIBLY STILL ONGOING EARLY FRIDAY MORNING, WITH
A CONTINUED HAIL IF NOT AN ISOLATED WIND THREAT AS WELL, ALTHOUGH
SOME BL STABILITY SHOULD HINDER THE WIND THREAT. THE DYNAMICS OF THE
UPPER LOW WILL DRIVE A DRY SLOT THROUGH THE REGION OF FRIDAY, BUT
NOT BEFORE LATE MORNING/EARLY AFTERNOON DESTABILIZATION CONTRIBUTES
TO YET ANOTHER SEVERE EPISODE WITH AS GOOD OR BETTER CAPE AND SHEAR
COMBINATIONS.
TEMPERATURES WERE RAISED FOR FRIDAY MORNING, FOLLOWING THE NAM AND
GFS, AS OVERNIGHT CONVECTION SHOULD LIMIT THE RADIATIONAL COOLING.
ADDITIONALLY THE POPS WERE RAISED LOWERED FRIDAY MORNING AND
INCREASED ALONG THE MOISTURE TRANSPORT AXIS INTO FRIDAY AFTERNOON
WITH A MODEL CONSENSUS.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 1152 AM CDT THU APR 16 2015
FRIDAY NIGHT INTO SATURDAY WE WILL STILL BE DEALING WITH THE SLOW-
MOVING UPPER LOW, BUT BY THIS TIME THE LOW WILL BE SEVERELY OCCLUDED
WITH THE DRY INTRUSION WORKING IN FAST FROM THE SOUTHWEST. IN FACT,
FRIDAY NIGHT LOOKS RATHER DRY NOW WITH THE SYNOPTIC DRY INTRUSION
ACROSS MUCH OF KANSAS. WE HAVE REDUCED POPS AS A RESULT FRIDAY
NIGHT. AS WE HEAD INTO SATURDAY, ANY DAYTIME HEATING WILL PROMOTE
SHOWER AND ISOLATED THUNDERSTORM DEVELOPMENT AS THE CORE OF THE MID
LEVEL CYCLONE WALLOWS SLOWLY EASTWARD INTO FAR WESTERN KANSAS. WE
WILL MAINTAIN THE 20-40 POPS ACROSS MAINLY THE NORTHERN AND EASTERN
ZONES WITH A DRY FORECAST ACROSS FAR SOUTHWEST KANSAS.
WHAT IS LEFT OF THE LOW WILL FINALLY PULL AWAY SATURDAY NIGHT INTO
EARLY SUNDAY WITH FAIRLY STRONG NORTH WINDS TO FOLLOW DURING THE DAY
SUNDAY. WE COULD STILL SEE SOME WRAP-AROUND LIGHT PRECIPITATION IN
THE WEAKENING MID LEVEL DEFORMATION AXIS, HENCE THE 20 TOP 30 POPS
FOR MUCH OF THE AREA. LOOKING BEYOND THE WEEKEND, WE WILL ENTER A
NORTHWEST FLOW PATTERN ON THE SOUTHWEST SIDE OF A LARGE-SCALE UPPER
TROUGH ACROSS THE GREAT LAKES REGION. THE ATMOSPHERE WILL BE FAIRLY
COOL EARLY NEXT WEEK AS A RESULT WITH LARGE SCALE HIGH PRESSURE AT
THE SURFACE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1256 AM CDT FRI APR 17 2015
AREAS OF RAIN AND THUNDERSTORMS WILL AFFECT THE TAF SITES
PERIODICALLY THROUGH THE PERIOD. MUCH OF THE TIME, VFR CONDITIONS
WILL PERSIST, WITH SOUTHEAST WINDS AT 10 TO 15 KTS OUTSIDE OF
THUNDERSTORMS. VISIBILITIES MAY DROP TO MVFR IN ANY THUNDERSTORMS
WITH CEILINGS REMAINING VFR/MVFR, EXCEPT FOR IN ANY HEAVIER
SHOWERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 69 45 65 / 60 30 40 30
GCK 48 69 44 62 / 60 30 40 30
EHA 42 66 43 62 / 30 20 20 20
LBL 46 69 45 63 / 40 30 30 20
HYS 56 71 48 62 / 60 50 50 40
P28 56 72 51 67 / 60 40 50 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...UMSCHEID
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS JACKSON KY
200 PM EDT FRI APR 17 2015
.UPDATE...
ISSUED AT 200 PM EDT FRI APR 17 2015
QUICK UPDATE TO ALIGN T AND TD GRIDS WITH MOST RECENT OBS. NO
OTHER CHANGES WERE MADE TO THE FORECAST. SENT UPDATED GRIDS TO
NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1058 AM EDT FRI APR 17 2015
WV IMAGERY INDICATES THAT THE WEAK TROUGH HAS PUSHED EAST OF THE
AREA SO HAVE TRENDED POPS DOWN OVER THE NEXT 3 TO 6 HOURS...STILL
KEPT A SLIGHT CHANCE IN OUR SOUTHEASTERN COUNTIES TO REMAIN WITHIN
TOLERANCE WITH OUR NEIGHBORS DURING THAT TIME. OTHERWISE...IT/S
JUST A CLOUD COVER AND TEMPERATURE FORECAST TODAY. SO HAVE UPDATED
T AND TD GRIDS TO ALIGN WITH MOST RECENT OBS. NO OTHER CHANGES
WERE MADE TO THE CURRENT FORECAST BUT WILL KEEP AN EYE ON CLOUD
COVER AND TEMPS INTO THE AFTERNOON. SENT UPDATED GRIDS TO NDFD
AND WEB SERVERS.
UPDATE ISSUED AT 809 AM EDT FRI APR 17 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME LOW LEVEL CLOUDS
JUST TO THE WEST ASSOCIATED WITH A WEAK TROUGH MOVING THROUGH.
THIS HAS ALSO SPAWNED A FEW SHOWERS ACROSS THE AREA. RECENT RADAR
RETURNS HINT AT SOME OF THE ACTIVITY MAYBE DEVELOPING FURTHER
SOUTH SO HAVE LEFT POPS IN THROUGH MIDDAY. AS WELL HAVE PUT FOG IN
THE FORECAST LATE TONIGHT. WITH HIGH PRESSURE MOVING INTO THE AREA
AND CLEARING SKIES LATER TODAY...AS WELL A MOIST SURFACE LAYER AND
LIGHT WINDS WILL BE A FAVORABLE ENVIRONMENT FOR FOG DEVELOPMENT.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EDT FRI APR 17 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME MOIST SOUTHERLY
FLOW MOVING INTO KENTUCKY FROM THE SOUTHWEST THIS MORNING. AT THIS
TIME...WEAK SURFACE HIGH PRESSURE CENTERED OVER MI IS POISED TO
SLOWLY CREEP SOUTHEAST. IN THIS AREA OVER THE LOWER GREAT
LAKES...A BIT OF CLEARING MAY MAKE IT INTO EAST KENTUCKY THIS
MORNING. THIS COMBINED WITH THE MOISTURE PRESENT OVER THE AREA MAY
RESULT IN SOME DENSE FOG DEVELOPMENT TOWARDS DAWN. AT THIS
POINT...IT LOOKS LIKE A TOUGH CALL WITH CLOUD COVER CONTINUING TO
STREAM IN FROM THE SOUTHWEST. HAVE PUT PATCHY FOG IN THE FORECAST
TO COVER THIS BUT WILL ALSO MONITOR FOG DEVELOPMENT TOWARDS DAWN.
IN ADDITION TO THIS...A WEAK REMNANT TROUGH SLIDING EAST AHEAD OF
HIGH PRESSURE MAY BE ENOUGH TO SPAWN A FEW SHOWERS. HI RES MODELS
SUCH AS THE HRRR DO HINT AT THIS INTO THE DAY AS THIS TROUGH
SLOWLY SLIDES THROUGH. WITH NO REAL SURFACE FEATURE THIS ACTIVITY
IS TIED TO...WILL GO WITH SLIGHT CHANCE POPS THROUGH MIDDAY AND
ONLY SHOWERS EXPECTED.
HEADING INTO TONIGHT...MENTIONED HIGH PRESSURE WILL MOVE INTO THE
AREA TONIGHT. SOME BREAKS IN THE CLOUD COVER IS
EXPECTED...ESPECIALLY OVER THE NORTH WHERE SOME CLEAR SKIES LOOK
TO DEVELOP. THIS MAY POSE AS A BETTER FOG SET UP AND MAY NEED TO
MENTION THIS IN THE HWO. BY SATURDAY...A CLOSED UPPER LOW EJECTS
INTO THE CENTRAL PLAINS...AND A SHORTWAVE MOVES OUT OF THE BASE OF
THE LOW...CROSSING THE LOWER MS RIVER VALLEY AND NORTHEAST INTO
THE OH AND TN VALLEYS. SURFACE LOW PRESSURE AND A DEVELOPING WARM
FRONT WILL BRING A SURGE OF MOIST AIR INTO EAST KENTUCKY WITH A
SLIGHT CHANCE POPS MAKING MAKING IT INTO POINTS SOUTH OF THE HAL
ROGERS PARKWAY BY SATURDAY AFTERNOON. MODELS WITH THIS FEATURE
HAVE BEEN PRETTY CONSISTENT AND THE BEST CHANCE OF MEASURABLE
PRECIP WILL BE AFTER 00Z SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 335 AM EDT FRI APR 17 2015
CLOSED UPPER LEVEL LOW THAT HAS BEEN QUASI STATIONARY ACROSS THE
DESERT SW WILL FINALLY BEGIN PHASING WITH A NORTHERN STREAM TROUGH
AS WE MOVE INTO THE LONG RANGE PERIOD. DIFFLUENCE ALOFT...JET
ENERGY... AND SHORTWAVE WILL AID IN DEVELOPING SURFACE LOW
PRESSURE ACROSS THE SOUTHERN MISSISSIPPI RIVER VALLEY SATURDAY
NIGHT. THIS WILL HELP TO SPREAD SHOWERS AND THUNDERSTORMS ACROSS
THE REGION AS WE MOVE THROUGH THE DAY ON SUNDAY. MODEL SOUNDINGS
WOULD SUGGEST PWATS BETWEEN 1.2 AND 1.4 INCHES DURING THIS PERIOD
AS COLUMN SATURATES...THEREFORE SOME OF THESE SHOWERS AND STORMS
WILL LIKELY BE MODERATE INTENSITY AT TIMES. GIVEN THE VERY WET
ANTECEDENT CONDITIONS WE COULD SEE ISOLATED FLOODING THREAT ONCE
AGAIN. THIS WILL DEPEND ON THE DEVELOPMENT AND MOVEMENT OF THE LOW
PRESSURE THAT DEVELOPS AND MOVES NORTH NORTHEAST SUNDAY AND ALSO
ANY CONVECTION THAT DEVELOPS. THIS UPPER LEVEL SYSTEM DOES LOOK TO
PHASE WITH THE NORTHERN STREAM TROUGH AS MENTIONED ABOVE AND A
CLOSED UPPER LEVEL LOW DEVELOPS ACROSS THE NORTHERN PLAINS. THIS
WILL MAKE FOR A TWO PART SYSTEM AS ANOTHER SURFACE LOW DEVELOPS
ACROSS THE UPPER MIDWEST SUNDAY EVENING ASSOCIATED WITH A SPOKE OF
ENERGY FROM THE CLOSED UPPER LEVEL LOW. THIS LOW PRESSURE WILL
DRAG A COLD FRONT ACROSS THE REGION MONDAY AND RESULT IN ANOTHER
ROUND OF SHOWERS AND THUNDERSTORMS. UP TO THIS POINT WE DO SEE
GOOD MODEL AGREEMENT IN REGARDS TO THIS SYSTEM.
PASSAGE OF THIS FRONT WILL BREAKDOWN THE PATTERN WITH MORE OF A
WESTERLY FLOW AND COOLER AIR USHERED IN BEHIND THE FRONT. AN AREA
OF HIGH PRESSURE WILL BUILD TO THE SOUTH WITH HIGHS TEMPS IN THE
LOW TO MID 60S AND LOWS IN THE UPPER TO EVEN LOWER 40S TUESDAY
INTO WEDNESDAY. MORE DIVERGENCE IN THE MODEL GUIDANCE EXISTS IN
THE WEDNESDAY TO THURSDAY TIME FRAME. RIGHT NOW THE GFS AND GFS
ENSEMBLE MEAN ARE WETTER THAN THE ECMWF AT THIS POINT. GIVEN THE
UNCERTAINTY THAT EXISTS WILL LEAN TOWARD THE MODEL BLEND. THIS
WILL BRING SLIGHT POPS ACROSS THE NORTH WEDNESDAY AFTERNOON AND
CHANCE TO SLIGHT POPS WEDNESDAY NIGHT INTO THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 155 PM EDT FRI APR 17 2015
LOW LEVEL CLOUDS HAVE HAD A HARD TIME BREAKING UP THIS AFTERNOON.
BUT GIVEN RECENT VIS IMAGERY TRENDS...EXPECT MUCH OF THE
REMAINING CLOUD COVER TO CONTINUE BREAKING UP AND CIGS TO IMPROVE
TO VFR THROUGHOUT THE REMAINDER OF THE AFTERNOON. HIGH PRESSURE
MOVING IN LATER THIS EVENING AND TONIGHT ALONG WITH LIGHT WINDS
WILL PROVIDE AN ENVIRONMENT FAVORABLE FOR FOG DEVELOPMENT AND SO
HAVE PUT IFR VIS IN THE LOZ...JKL...SJS...SYM TAF SITES AND
ALTERNATE MINS AT THE SME TAF SITE TONIGHT AFTER 06Z. CONDITIONS
SHOULD THEN IMPROVE TO VFR ACROSS ALL TAF SITES AROUND 13Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JVM
SHORT TERM...SHALLENBERGER
LONG TERM...DJ
AVIATION...JVM
AREA FORECAST DISCUSSION
NWS JACKSON KY
155 PM EDT FRI APR 17 2015
.UPDATE...
ISSUED AT 1058 AM EDT FRI APR 17 2015
WV IMAGERY INDICATES THAT THE WEAK TROUGH HAS PUSHED EAST OF THE
AREA SO HAVE TRENDED POPS DOWN OVER THE NEXT 3 TO 6 HOURS...STILL
KEPT A SLIGHT CHANCE IN OUR SOUTHEASTERN COUNTIES TO REMAIN WITHIN
TOLERANCE WITH OUR NEIGHBORS DURING THAT TIME. OTHERWISE...IT/S
JUST A CLOUD COVER AND TEMPERATURE FORECAST TODAY. SO HAVE UPDATED
T AND TD GRIDS TO ALIGN WITH MOST RECENT OBS. NO OTHER CHANGES
WERE MADE TO THE CURRENT FORECAST BUT WILL KEEP AN EYE ON CLOUD
COVER AND TEMPS INTO THE AFTERNOON. SENT UPDATED GRIDS TO NDFD
AND WEB SERVERS.
UPDATE ISSUED AT 809 AM EDT FRI APR 17 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME LOW LEVEL CLOUDS
JUST TO THE WEST ASSOCIATED WITH A WEAK TROUGH MOVING THROUGH.
THIS HAS ALSO SPAWNED A FEW SHOWERS ACROSS THE AREA. RECENT RADAR
RETURNS HINT AT SOME OF THE ACTIVITY MAYBE DEVELOPING FURTHER
SOUTH SO HAVE LEFT POPS IN THROUGH MIDDAY. AS WELL HAVE PUT FOG IN
THE FORECAST LATE TONIGHT. WITH HIGH PRESSURE MOVING INTO THE AREA
AND CLEARING SKIES LATER TODAY...AS WELL A MOIST SURFACE LAYER AND
LIGHT WINDS WILL BE A FAVORABLE ENVIRONMENT FOR FOG DEVELOPMENT.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EDT FRI APR 17 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME MOIST SOUTHERLY
FLOW MOVING INTO KENTUCKY FROM THE SOUTHWEST THIS MORNING. AT THIS
TIME...WEAK SURFACE HIGH PRESSURE CENTERED OVER MI IS POISED TO
SLOWLY CREEP SOUTHEAST. IN THIS AREA OVER THE LOWER GREAT
LAKES...A BIT OF CLEARING MAY MAKE IT INTO EAST KENTUCKY THIS
MORNING. THIS COMBINED WITH THE MOISTURE PRESENT OVER THE AREA MAY
RESULT IN SOME DENSE FOG DEVELOPMENT TOWARDS DAWN. AT THIS
POINT...IT LOOKS LIKE A TOUGH CALL WITH CLOUD COVER CONTINUING TO
STREAM IN FROM THE SOUTHWEST. HAVE PUT PATCHY FOG IN THE FORECAST
TO COVER THIS BUT WILL ALSO MONITOR FOG DEVELOPMENT TOWARDS DAWN.
IN ADDITION TO THIS...A WEAK REMNANT TROUGH SLIDING EAST AHEAD OF
HIGH PRESSURE MAY BE ENOUGH TO SPAWN A FEW SHOWERS. HI RES MODELS
SUCH AS THE HRRR DO HINT AT THIS INTO THE DAY AS THIS TROUGH
SLOWLY SLIDES THROUGH. WITH NO REAL SURFACE FEATURE THIS ACTIVITY
IS TIED TO...WILL GO WITH SLIGHT CHANCE POPS THROUGH MIDDAY AND
ONLY SHOWERS EXPECTED.
HEADING INTO TONIGHT...MENTIONED HIGH PRESSURE WILL MOVE INTO THE
AREA TONIGHT. SOME BREAKS IN THE CLOUD COVER IS
EXPECTED...ESPECIALLY OVER THE NORTH WHERE SOME CLEAR SKIES LOOK
TO DEVELOP. THIS MAY POSE AS A BETTER FOG SET UP AND MAY NEED TO
MENTION THIS IN THE HWO. BY SATURDAY...A CLOSED UPPER LOW EJECTS
INTO THE CENTRAL PLAINS...AND A SHORTWAVE MOVES OUT OF THE BASE OF
THE LOW...CROSSING THE LOWER MS RIVER VALLEY AND NORTHEAST INTO
THE OH AND TN VALLEYS. SURFACE LOW PRESSURE AND A DEVELOPING WARM
FRONT WILL BRING A SURGE OF MOIST AIR INTO EAST KENTUCKY WITH A
SLIGHT CHANCE POPS MAKING MAKING IT INTO POINTS SOUTH OF THE HAL
ROGERS PARKWAY BY SATURDAY AFTERNOON. MODELS WITH THIS FEATURE
HAVE BEEN PRETTY CONSISTENT AND THE BEST CHANCE OF MEASURABLE
PRECIP WILL BE AFTER 00Z SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 335 AM EDT FRI APR 17 2015
CLOSED UPPER LEVEL LOW THAT HAS BEEN QUASI STATIONARY ACROSS THE
DESERT SW WILL FINALLY BEGIN PHASING WITH A NORTHERN STREAM TROUGH
AS WE MOVE INTO THE LONG RANGE PERIOD. DIFFLUENCE ALOFT...JET
ENERGY... AND SHORTWAVE WILL AID IN DEVELOPING SURFACE LOW
PRESSURE ACROSS THE SOUTHERN MISSISSIPPI RIVER VALLEY SATURDAY
NIGHT. THIS WILL HELP TO SPREAD SHOWERS AND THUNDERSTORMS ACROSS
THE REGION AS WE MOVE THROUGH THE DAY ON SUNDAY. MODEL SOUNDINGS
WOULD SUGGEST PWATS BETWEEN 1.2 AND 1.4 INCHES DURING THIS PERIOD
AS COLUMN SATURATES...THEREFORE SOME OF THESE SHOWERS AND STORMS
WILL LIKELY BE MODERATE INTENSITY AT TIMES. GIVEN THE VERY WET
ANTECEDENT CONDITIONS WE COULD SEE ISOLATED FLOODING THREAT ONCE
AGAIN. THIS WILL DEPEND ON THE DEVELOPMENT AND MOVEMENT OF THE LOW
PRESSURE THAT DEVELOPS AND MOVES NORTH NORTHEAST SUNDAY AND ALSO
ANY CONVECTION THAT DEVELOPS. THIS UPPER LEVEL SYSTEM DOES LOOK TO
PHASE WITH THE NORTHERN STREAM TROUGH AS MENTIONED ABOVE AND A
CLOSED UPPER LEVEL LOW DEVELOPS ACROSS THE NORTHERN PLAINS. THIS
WILL MAKE FOR A TWO PART SYSTEM AS ANOTHER SURFACE LOW DEVELOPS
ACROSS THE UPPER MIDWEST SUNDAY EVENING ASSOCIATED WITH A SPOKE OF
ENERGY FROM THE CLOSED UPPER LEVEL LOW. THIS LOW PRESSURE WILL
DRAG A COLD FRONT ACROSS THE REGION MONDAY AND RESULT IN ANOTHER
ROUND OF SHOWERS AND THUNDERSTORMS. UP TO THIS POINT WE DO SEE
GOOD MODEL AGREEMENT IN REGARDS TO THIS SYSTEM.
PASSAGE OF THIS FRONT WILL BREAKDOWN THE PATTERN WITH MORE OF A
WESTERLY FLOW AND COOLER AIR USHERED IN BEHIND THE FRONT. AN AREA
OF HIGH PRESSURE WILL BUILD TO THE SOUTH WITH HIGHS TEMPS IN THE
LOW TO MID 60S AND LOWS IN THE UPPER TO EVEN LOWER 40S TUESDAY
INTO WEDNESDAY. MORE DIVERGENCE IN THE MODEL GUIDANCE EXISTS IN
THE WEDNESDAY TO THURSDAY TIME FRAME. RIGHT NOW THE GFS AND GFS
ENSEMBLE MEAN ARE WETTER THAN THE ECMWF AT THIS POINT. GIVEN THE
UNCERTAINTY THAT EXISTS WILL LEAN TOWARD THE MODEL BLEND. THIS
WILL BRING SLIGHT POPS ACROSS THE NORTH WEDNESDAY AFTERNOON AND
CHANCE TO SLIGHT POPS WEDNESDAY NIGHT INTO THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 155 PM EDT FRI APR 17 2015
LOW LEVEL CLOUDS HAVE HAD A HARD TIME BREAKING UP THIS AFTERNOON.
BUT GIVEN RECENT VIS IMAGERY TRENDS...EXPECT MUCH OF THE
REMAINING CLOUD COVER TO CONTINUE BREAKING UP AND CIGS TO IMPROVE
TO VFR THROUGHOUT THE REMAINDER OF THE AFTERNOON. HIGH PRESSURE
MOVING IN LATER THIS EVENING AND TONIGHT ALONG WITH LIGHT WINDS
WILL PROVIDE AN ENVIRONMENT FAVORABLE FOR FOG DEVELOPMENT AND SO
HAVE PUT IFR VIS IN THE LOZ...JKL...SJS...SYM TAF SITES AND
ALTERNATE MINS AT THE SME TAF SITE TONIGHT AFTER 06Z. CONDITIONS
SHOULD THEN IMPROVE TO VFR ACROSS ALL TAF SITES AROUND 13Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JVM
SHORT TERM...SHALLENBERGER
LONG TERM...DJ
AVIATION...JVM
AREA FORECAST DISCUSSION
NWS JACKSON KY
1058 AM EDT FRI APR 17 2015
.UPDATE...
ISSUED AT 1058 AM EDT FRI APR 17 2015
WV IMAGERY INDICATES THAT THE WEAK TROUGH HAS PUSHED EAST OF THE
AREA SO HAVE TRENDED POPS DOWN OVER THE NEXT 3 TO 6 HOURS...STILL
KEPT A SLIGHT CHANCE IN OUR SOUTHEASTERN COUNTIES TO REMAIN WITHIN
TOLERANCE WITH OUR NEIGHBORS DURING THAT TIME. OTHERWISE...IT/S
JUST A CLOUD COVER AND TEMPERATURE FORECAST TODAY. SO HAVE UPDATED
T AND TD GRIDS TO ALIGN WITH MOST RECENT OBS. NO OTHER CHANGES
WERE MADE TO THE CURRENT FORECAST BUT WILL KEEP AN EYE ON CLOUD
COVER AND TEMPS INTO THE AFTERNOON. SENT UPDATED GRIDS TO NDFD
AND WEB SERVERS.
UPDATE ISSUED AT 809 AM EDT FRI APR 17 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME LOW LEVEL CLOUDS
JUST TO THE WEST ASSOCIATED WITH A WEAK TROUGH MOVING THROUGH.
THIS HAS ALSO SPAWNED A FEW SHOWERS ACROSS THE AREA. RECENT RADAR
RETURNS HINT AT SOME OF THE ACTIVITY MAYBE DEVELOPING FURTHER
SOUTH SO HAVE LEFT POPS IN THROUGH MIDDAY. AS WELL HAVE PUT FOG IN
THE FORECAST LATE TONIGHT. WITH HIGH PRESSURE MOVING INTO THE AREA
AND CLEARING SKIES LATER TODAY...AS WELL A MOIST SURFACE LAYER AND
LIGHT WINDS WILL BE A FAVORABLE ENVIRONMENT FOR FOG DEVELOPMENT.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EDT FRI APR 17 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME MOIST SOUTHERLY
FLOW MOVING INTO KENTUCKY FROM THE SOUTHWEST THIS MORNING. AT THIS
TIME...WEAK SURFACE HIGH PRESSURE CENTERED OVER MI IS POISED TO
SLOWLY CREEP SOUTHEAST. IN THIS AREA OVER THE LOWER GREAT
LAKES...A BIT OF CLEARING MAY MAKE IT INTO EAST KENTUCKY THIS
MORNING. THIS COMBINED WITH THE MOISTURE PRESENT OVER THE AREA MAY
RESULT IN SOME DENSE FOG DEVELOPMENT TOWARDS DAWN. AT THIS
POINT...IT LOOKS LIKE A TOUGH CALL WITH CLOUD COVER CONTINUING TO
STREAM IN FROM THE SOUTHWEST. HAVE PUT PATCHY FOG IN THE FORECAST
TO COVER THIS BUT WILL ALSO MONITOR FOG DEVELOPMENT TOWARDS DAWN.
IN ADDITION TO THIS...A WEAK REMNANT TROUGH SLIDING EAST AHEAD OF
HIGH PRESSURE MAY BE ENOUGH TO SPAWN A FEW SHOWERS. HI RES MODELS
SUCH AS THE HRRR DO HINT AT THIS INTO THE DAY AS THIS TROUGH
SLOWLY SLIDES THROUGH. WITH NO REAL SURFACE FEATURE THIS ACTIVITY
IS TIED TO...WILL GO WITH SLIGHT CHANCE POPS THROUGH MIDDAY AND
ONLY SHOWERS EXPECTED.
HEADING INTO TONIGHT...MENTIONED HIGH PRESSURE WILL MOVE INTO THE
AREA TONIGHT. SOME BREAKS IN THE CLOUD COVER IS
EXPECTED...ESPECIALLY OVER THE NORTH WHERE SOME CLEAR SKIES LOOK
TO DEVELOP. THIS MAY POSE AS A BETTER FOG SET UP AND MAY NEED TO
MENTION THIS IN THE HWO. BY SATURDAY...A CLOSED UPPER LOW EJECTS
INTO THE CENTRAL PLAINS...AND A SHORTWAVE MOVES OUT OF THE BASE OF
THE LOW...CROSSING THE LOWER MS RIVER VALLEY AND NORTHEAST INTO
THE OH AND TN VALLEYS. SURFACE LOW PRESSURE AND A DEVELOPING WARM
FRONT WILL BRING A SURGE OF MOIST AIR INTO EAST KENTUCKY WITH A
SLIGHT CHANCE POPS MAKING MAKING IT INTO POINTS SOUTH OF THE HAL
ROGERS PARKWAY BY SATURDAY AFTERNOON. MODELS WITH THIS FEATURE
HAVE BEEN PRETTY CONSISTENT AND THE BEST CHANCE OF MEASURABLE
PRECIP WILL BE AFTER 00Z SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 335 AM EDT FRI APR 17 2015
CLOSED UPPER LEVEL LOW THAT HAS BEEN QUASI STATIONARY ACROSS THE
DESERT SW WILL FINALLY BEGIN PHASING WITH A NORTHERN STREAM TROUGH
AS WE MOVE INTO THE LONG RANGE PERIOD. DIFFLUENCE ALOFT...JET
ENERGY... AND SHORTWAVE WILL AID IN DEVELOPING SURFACE LOW
PRESSURE ACROSS THE SOUTHERN MISSISSIPPI RIVER VALLEY SATURDAY
NIGHT. THIS WILL HELP TO SPREAD SHOWERS AND THUNDERSTORMS ACROSS
THE REGION AS WE MOVE THROUGH THE DAY ON SUNDAY. MODEL SOUNDINGS
WOULD SUGGEST PWATS BETWEEN 1.2 AND 1.4 INCHES DURING THIS PERIOD
AS COLUMN SATURATES...THEREFORE SOME OF THESE SHOWERS AND STORMS
WILL LIKELY BE MODERATE INTENSITY AT TIMES. GIVEN THE VERY WET
ANTECEDENT CONDITIONS WE COULD SEE ISOLATED FLOODING THREAT ONCE
AGAIN. THIS WILL DEPEND ON THE DEVELOPMENT AND MOVEMENT OF THE LOW
PRESSURE THAT DEVELOPS AND MOVES NORTH NORTHEAST SUNDAY AND ALSO
ANY CONVECTION THAT DEVELOPS. THIS UPPER LEVEL SYSTEM DOES LOOK TO
PHASE WITH THE NORTHERN STREAM TROUGH AS MENTIONED ABOVE AND A
CLOSED UPPER LEVEL LOW DEVELOPS ACROSS THE NORTHERN PLAINS. THIS
WILL MAKE FOR A TWO PART SYSTEM AS ANOTHER SURFACE LOW DEVELOPS
ACROSS THE UPPER MIDWEST SUNDAY EVENING ASSOCIATED WITH A SPOKE OF
ENERGY FROM THE CLOSED UPPER LEVEL LOW. THIS LOW PRESSURE WILL
DRAG A COLD FRONT ACROSS THE REGION MONDAY AND RESULT IN ANOTHER
ROUND OF SHOWERS AND THUNDERSTORMS. UP TO THIS POINT WE DO SEE
GOOD MODEL AGREEMENT IN REGARDS TO THIS SYSTEM.
PASSAGE OF THIS FRONT WILL BREAKDOWN THE PATTERN WITH MORE OF A
WESTERLY FLOW AND COOLER AIR USHERED IN BEHIND THE FRONT. AN AREA
OF HIGH PRESSURE WILL BUILD TO THE SOUTH WITH HIGHS TEMPS IN THE
LOW TO MID 60S AND LOWS IN THE UPPER TO EVEN LOWER 40S TUESDAY
INTO WEDNESDAY. MORE DIVERGENCE IN THE MODEL GUIDANCE EXISTS IN
THE WEDNESDAY TO THURSDAY TIME FRAME. RIGHT NOW THE GFS AND GFS
ENSEMBLE MEAN ARE WETTER THAN THE ECMWF AT THIS POINT. GIVEN THE
UNCERTAINTY THAT EXISTS WILL LEAN TOWARD THE MODEL BLEND. THIS
WILL BRING SLIGHT POPS ACROSS THE NORTH WEDNESDAY AFTERNOON AND
CHANCE TO SLIGHT POPS WEDNESDAY NIGHT INTO THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 809 AM EDT FRI APR 17 2015
SOME LOW LEVEL CLOUD COVER ASSOCIATED WITH A WEAK TROUGH MOVING
THROUGH FROM THE NORTHWEST WILL BRING SOME 2 TO 3 KFT CEILINGS
THROUGH THE AREA BETWEEN 12Z AND 15Z THIS MORNING.
AFTERWARD...SKIES WILL BEGIN TO CLEAR OUT BY THE AFTERNOON AND
EVENING. HIGH PRESSURE MOVING IN LATER THIS EVENING AND TONIGHT
ALONG WITH LIGHT WINDS WILL PROVIDE AN ENVIRONMENT FAVORABLE FOR
FOG DEVELOPMENT AND SO HAVE PUT IFR VIS IN ALL THE TAF SITES
TONIGHT AFTER 06Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JVM
SHORT TERM...SHALLENBERGER
LONG TERM...DJ
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
810 AM EDT FRI APR 17 2015
.UPDATE...
ISSUED AT 809 AM EDT FRI APR 17 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME LOW LEVEL CLOUDS
JUST TO THE WEST ASSOCIATED WITH A WEAK TROUGH MOVING THROUGH.
THIS HAS ALSO SPAWNED A FEW SHOWERS ACROSS THE AREA. RECENT RADAR
RETURNS HINT AT SOME OF THE ACTIVITY MAYBE DEVELOPING FURTHER
SOUTH SO HAVE LEFT POPS IN THROUGH MIDDAY. AS WELL HAVE PUT FOG IN
THE FORECAST LATE TONIGHT. WITH HIGH PRESSURE MOVING INTO THE AREA
AND CLEARING SKIES LATER TODAY...AS WELL A MOIST SURFACE LAYER AND
LIGHT WINDS WILL BE A FAVORABLE ENVIRONMENT FOR FOG DEVELOPMENT.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EDT FRI APR 17 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME MOIST SOUTHERLY
FLOW MOVING INTO KENTUCKY FROM THE SOUTHWEST THIS MORNING. AT THIS
TIME...WEAK SURFACE HIGH PRESSURE CENTERED OVER MI IS POISED TO
SLOWLY CREEP SOUTHEAST. IN THIS AREA OVER THE LOWER GREAT
LAKES...A BIT OF CLEARING MAY MAKE IT INTO EAST KENTUCKY THIS
MORNING. THIS COMBINED WITH THE MOISTURE PRESENT OVER THE AREA MAY
RESULT IN SOME DENSE FOG DEVELOPMENT TOWARDS DAWN. AT THIS
POINT...IT LOOKS LIKE A TOUGH CALL WITH CLOUD COVER CONTINUING TO
STREAM IN FROM THE SOUTHWEST. HAVE PUT PATCHY FOG IN THE FORECAST
TO COVER THIS BUT WILL ALSO MONITOR FOG DEVELOPMENT TOWARDS DAWN.
IN ADDITION TO THIS...A WEAK REMNANT TROUGH SLIDING EAST AHEAD OF
HIGH PRESSURE MAY BE ENOUGH TO SPAWN A FEW SHOWERS. HI RES MODELS
SUCH AS THE HRRR DO HINT AT THIS INTO THE DAY AS THIS TROUGH
SLOWLY SLIDES THROUGH. WITH NO REAL SURFACE FEATURE THIS ACTIVITY
IS TIED TO...WILL GO WITH SLIGHT CHANCE POPS THROUGH MIDDAY AND
ONLY SHOWERS EXPECTED.
HEADING INTO TONIGHT...MENTIONED HIGH PRESSURE WILL MOVE INTO THE
AREA TONIGHT. SOME BREAKS IN THE CLOUD COVER IS
EXPECTED...ESPECIALLY OVER THE NORTH WHERE SOME CLEAR SKIES LOOK
TO DEVELOP. THIS MAY POSE AS A BETTER FOG SET UP AND MAY NEED TO
MENTION THIS IN THE HWO. BY SATURDAY...A CLOSED UPPER LOW EJECTS
INTO THE CENTRAL PLAINS...AND A SHORTWAVE MOVES OUT OF THE BASE OF
THE LOW...CROSSING THE LOWER MS RIVER VALLEY AND NORTHEAST INTO
THE OH AND TN VALLEYS. SURFACE LOW PRESSURE AND A DEVELOPING WARM
FRONT WILL BRING A SURGE OF MOIST AIR INTO EAST KENTUCKY WITH A
SLIGHT CHANCE POPS MAKING MAKING IT INTO POINTS SOUTH OF THE HAL
ROGERS PARKWAY BY SATURDAY AFTERNOON. MODELS WITH THIS FEATURE
HAVE BEEN PRETTY CONSISTENT AND THE BEST CHANCE OF MEASURABLE
PRECIP WILL BE AFTER 00Z SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 335 AM EDT FRI APR 17 2015
CLOSED UPPER LEVEL LOW THAT HAS BEEN QUASI STATIONARY ACROSS THE
DESERT SW WILL FINALLY BEGIN PHASING WITH A NORTHERN STREAM TROUGH
AS WE MOVE INTO THE LONG RANGE PERIOD. DIFFLUENCE ALOFT...JET
ENERGY... AND SHORTWAVE WILL AID IN DEVELOPING SURFACE LOW
PRESSURE ACROSS THE SOUTHERN MISSISSIPPI RIVER VALLEY SATURDAY
NIGHT. THIS WILL HELP TO SPREAD SHOWERS AND THUNDERSTORMS ACROSS
THE REGION AS WE MOVE THROUGH THE DAY ON SUNDAY. MODEL SOUNDINGS
WOULD SUGGEST PWATS BETWEEN 1.2 AND AOA 1.4 INCHES DURING THIS
PERIOD AS COLUMN SATURATES...THEREFORE SOME OF THESE SHOWERS AND
STORMS WILL LIKELY BE MODERATE INTENSITY AT TIMES. GIVEN THE VERY
WET ANTECEDENT CONDITIONS WE COULD SEE ISOLATED FLOODING THREAT
ONCE AGAIN. THIS WILL DEPEND ON THE DEVELOPMENT AND MOVEMENT OF
THE LOW PRESSURE THAT DEVELOPS AND MOVES NORTH NORTHEAST SUNDAY
AND ALSO ANY CONVECTION THAT DEVELOPS. THIS UPPER LEVEL SYSTEM
DOES LOOK TO PHASE WITH THE NORTHERN STREAM TROUGH AS MENTIONED
ABOVE AND A CLOSED UPPER LEVEL LOW DEVELOPS ACROSS THE NORTHERN
PLAINS. THIS WILL MAKE FOR A TWO PART SYSTEM AS ANOTHER SURFACE
LOW DEVELOPS ACROSS THE UPPER MIDWEST SUNDAY EVENING ASSOCIATED
WITH A SPOKE OF ENERGY FROM THE CLOSED UPPER LEVEL LOW. THIS LOW
PRESSURE WILL DRAG A COLD FRONT ACROSS THE REGION MONDAY AND
RESULT IN ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. UP TO THIS
POINT WE DO SEE GOOD MODEL AGREEMENT IN REGARDS TO THIS SYSTEM.
PASSAGE OF THIS FRONT WILL BREAKDOWN THE PATTERN WITH MORE OF A
WESTERLY FLOW AND COOLER AIR USHERED IN BEHIND THE FRONT. AN AREA
OF HIGH PRESSURE WILL BUILD TO THE SOUTH WITH HIGHS TEMPS IN THE
LOW TO MID 60S AND LOWS IN THE UPPER TO EVEN LOWER 40S TUESDAY
INTO WEDNESDAY. MORE DIVERGENCE IN THE MODEL GUIDANCE EXISTS IN
THE WEDNESDAY TO THURSDAY TIME FRAME. RIGHT NOW THE GFS AND GFS
ENSEMBLE MEAN ARE WETTER THAN THE ECMWF AT THIS POINT. GIVEN THE
UNCERTAINTY THAT EXISTS WILL LEAN TOWARD THE MODEL BLEND. THIS
WILL BRING SLIGHT POPS ACROSS THE NORTH WEDNESDAY AFTERNOON AND
CHANCE TO SLIGHT POPS WEDNESDAY NIGHT INTO THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 809 AM EDT FRI APR 17 2015
SOME LOW LEVEL CLOUD COVER ASSOCIATED WITH A WEAK TROUGH MOVING
THROUGH FROM THE NORTHWEST WILL BRING SOME 2 TO 3 KFT CEILINGS
THROUGH THE AREA BETWEEN 12Z AND 15Z THIS MORNING.
AFTERWARD...SKIES WILL BEGIN TO CLEAR OUT BY THE AFTERNOON AND
EVENING. HIGH PRESSURE MOVING IN LATER THIS EVENING AND TONIGHT
ALONG WITH LIGHT WINDS WILL PROVIDE AN ENVIRONMENT FAVORABLE FOR
FOG DEVELOPMENT AND SO HAVE PUT IFR VIS IN ALL THE TAF SITES
TONIGHT AFTER 06Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...SHALLENBERGER
LONG TERM...DJ
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
335 AM EDT FRI APR 17 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EDT FRI APR 17 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME MOIST SOUTHERLY
FLOW MOVING INTO KENTUCKY FROM THE SOUTHWEST THIS MORNING. AT THIS
TIME...WEAK SURFACE HIGH PRESSURE CENTERED OVER MI IS POISED TO
SLOWLY CREEP SOUTHEAST. IN THIS AREA OVER THE LOWER GREAT
LAKES...A BIT OF CLEARING MAY MAKE IT INTO EAST KENTUCKY THIS
MORNING. THIS COMBINED WITH THE MOISTURE PRESENT OVER THE AREA MAY
RESULT IN SOME DENSE FOG DEVELOPMENT TOWARDS DAWN. AT THIS
POINT...IT LOOKS LIKE A TOUGH CALL WITH CLOUD COVER CONTINUING TO
STREAM IN FROM THE SOUTHWEST. HAVE PUT PATCHY FOG IN THE FORECAST
TO COVER THIS BUT WILL ALSO MONITOR FOG DEVELOPMENT TOWARDS DAWN.
IN ADDITION TO THIS...A WEAK REMNANT TROUGH SLIDING EAST AHEAD OF
HIGH PRESSURE MAY BE ENOUGH TO SPAWN A FEW SHOWERS. HI RES MODELS
SUCH AS THE HRRR DO HINT AT THIS INTO THE DAY AS THIS TROUGH
SLOWLY SLIDES THROUGH. WITH NO REAL SURFACE FEATURE THIS ACTIVITY
IS TIED TO...WILL GO WITH SLIGHT CHANCE POPS THROUGH MIDDAY AND
ONLY SHOWERS EXPECTED.
HEADING INTO TONIGHT...MENTIONED HIGH PRESSURE WILL MOVE INTO THE
AREA TONIGHT. SOME BREAKS IN THE CLOUD COVER IS
EXPECTED...ESPECIALLY OVER THE NORTH WHERE SOME CLEAR SKIES LOOK
TO DEVELOP. THIS MAY POSE AS A BETTER FOG SET UP AND MAY NEED TO
MENTION THIS IN THE HWO. BY SATURDAY...A CLOSED UPPER LOW EJECTS
INTO THE CENTRAL PLAINS...AND A SHORTWAVE MOVES OUT OF THE BASE OF
THE LOW...CROSSING THE LOWER MS RIVER VALLEY AND NORTHEAST INTO
THE OH AND TN VALLEYS. SURFACE LOW PRESSURE AND A DEVELOPING WARM
FRONT WILL BRING A SURGE OF MOIST AIR INTO EAST KENTUCKY WITH A
SLIGHT CHANCE POPS MAKING MAKING IT INTO POINTS SOUTH OF THE HAL
ROGERS PARKWAY BY SATURDAY AFTERNOON. MODELS WITH THIS FEATURE
HAVE BEEN PRETTY CONSISTENT AND THE BEST CHANCE OF MEASURABLE
PRECIP WILL BE AFTER 00Z SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 335 AM EDT FRI APR 17 2015
CLOSED UPPER LEVEL LOW THAT HAS BEEN QUASI STATIONARY ACROSS THE
DESERT SW WILL FINALLY BEGIN PHASING WITH A NORTHERN STREAM TROUGH
AS WE MOVE INTO THE LONG RANGE PERIOD. DIFFLUENCE ALOFT...JET
ENERGY... AND SHORTWAVE WILL AID IN DEVELOPING SURFACE LOW
PRESSURE ACROSS THE SOUTHERN MISSISSIPPI RIVER VALLEY SATURDAY
NIGHT. THIS WILL HELP TO SPREAD SHOWERS AND THUNDERSTORMS ACROSS
THE REGION AS WE MOVE THROUGH THE DAY ON SUNDAY. MODEL SOUNDINGS
WOULD SUGGEST PWATS BETWEEN 1.2 AND AOA 1.4 INCHES DURING THIS
PERIOD AS COLUMN SATURATES...THEREFORE SOME OF THESE SHOWERS AND
STORMS WILL LIKELY BE MODERATE INTENSITY AT TIMES. GIVEN THE VERY
WET ANTECEDENT CONDITIONS WE COULD SEE ISOLATED FLOODING THREAT
ONCE AGAIN. THIS WILL DEPEND ON THE DEVELOPMENT AND MOVEMENT OF
THE LOW PRESSURE THAT DEVELOPS AND MOVES NORTH NORTHEAST SUNDAY
AND ALSO ANY CONVECTION THAT DEVELOPS. THIS UPPER LEVEL SYSTEM
DOES LOOK TO PHASE WITH THE NORTHERN STREAM TROUGH AS MENTIONED
ABOVE AND A CLOSED UPPER LEVEL LOW DEVELOPS ACROSS THE NORTHERN
PLAINS. THIS WILL MAKE FOR A TWO PART SYSTEM AS ANOTHER SURFACE
LOW DEVELOPS ACROSS THE UPPER MIDWEST SUNDAY EVENING ASSOCIATED
WITH A SPOKE OF ENERGY FROM THE CLOSED UPPER LEVEL LOW. THIS LOW
PRESSURE WILL DRAG A COLD FRONT ACROSS THE REGION MONDAY AND
RESULT IN ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. UP TO THIS
POINT WE DO SEE GOOD MODEL AGREEMENT IN REGARDS TO THIS SYSTEM.
PASSAGE OF THIS FRONT WILL BREAKDOWN THE PATTERN WITH MORE OF A
WESTERLY FLOW AND COOLER AIR USHERED IN BEHIND THE FRONT. AN AREA
OF HIGH PRESSURE WILL BUILD TO THE SOUTH WITH HIGHS TEMPS IN THE
LOW TO MID 60S AND LOWS IN THE UPPER TO EVEN LOWER 40S TUESDAY
INTO WEDNESDAY. MORE DIVERGENCE IN THE MODEL GUIDANCE EXISTS IN
THE WEDNESDAY TO THURSDAY TIME FRAME. RIGHT NOW THE GFS AND GFS
ENSEMBLE MEAN ARE WETTER THAN THE ECMWF AT THIS POINT. GIVEN THE
UNCERTAINTY THAT EXISTS WILL LEAN TOWARD THE MODEL BLEND. THIS
WILL BRING SLIGHT POPS ACROSS THE NORTH WEDNESDAY AFTERNOON AND
CHANCE TO SLIGHT POPS WEDNESDAY NIGHT INTO THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 150 AM EDT FRI APR 17 2015
UPPER AND MID LEVEL CLOUD COVER WILL CONTINUE TO STREAM NORTH INTO
THE AREA THROUGH THE NIGHT. SOME WEAK INSTABILITY WILL CONTINUE TO
ALLOW SOME LOWER LEVEL CLOUD COVER TO DEVELOP TONIGHT AS WELL AS A
FEW SHOWERS. THIS LOOKS TO BE MAINLY ALONG THE SOUTHERN TAF SITES.
THE NORTHERN TAF SITES MAY SEE A BREAK IN CLOUD COVER HERE AND
THERE. TOWARD DAWN...SOME IFR CLOUD COVER LOOKS TO DEVELOP ACROSS
THE AREA AND HAVE PUT THIS INTO THE TAFS. WINDS WILL REMAIN LIGHT
THROUGH THE PERIOD. HIGH PRESSURE MOVING IN LATER IN THE TAF
PERIOD WILL SHUNT THIS LOWER LEVEL CLOUD COVER TO THE EAST TOWARDS
MIDDAY FRIDAY WITH MAINLY CLEAR SKIES OR CIRRUS EXPECTED.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SHALLENBERGER
LONG TERM...DJ
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
332 AM EDT FRI APR 17 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EDT FRI APR 17 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME MOIST SOUTHERLY
FLOW MOVING INTO KENTUCKY FROM THE SOUTHWEST THIS MORNING. AT THIS
TIME...WEAK SURFACE HIGH PRESSURE CENTERED OVER MI IS POISED TO
SLOWLY CREEP SOUTHEAST. IN THIS AREA OVER THE LOWER GREAT
LAKES...A BIT OF CLEARING MAY MAKE IT INTO EAST KENTUCKY THIS
MORNING. THIS COMBINED WITH THE MOISTURE PRESENT OVER THE AREA MAY
RESULT IN SOME DENSE FOG DEVELOPMENT TOWARDS DAWN. AT THIS
POINT...IT LOOKS LIKE A TOUGH CALL WITH CLOUD COVER CONTINUING TO
STREAM IN FROM THE SOUTHWEST. HAVE PUT PATCHY FOG IN THE FORECAST
TO COVER THIS BUT WILL ALSO MONITOR FOG DEVELOPMENT TOWARDS DAWN.
IN ADDITION TO THIS...A WEAK REMNANT TROUGH SLIDING EAST AHEAD OF
HIGH PRESSURE MAY BE ENOUGH TO SPAWN A FEW SHOWERS. HI RES MODELS
SUCH AS THE HRRR DO HINT AT THIS INTO THE DAY AS THIS TROUGH
SLOWLY SLIDES THROUGH. WITH NO REAL SURFACE FEATURE THIS ACTIVITY
IS TIED TO...WILL GO WITH SLIGHT CHANCE POPS THROUGH MIDDAY AND
ONLY SHOWERS EXPECTED.
HEADING INTO TONIGHT...MENTIONED HIGH PRESSURE WILL MOVE INTO THE
AREA TONIGHT. SOME BREAKS IN THE CLOUD COVER IS
EXPECTED...ESPECIALLY OVER THE NORTH WHERE SOME CLEAR SKIES LOOK
TO DEVELOP. THIS MAY POSE AS A BETTER FOG SET UP AND MAY NEED TO
MENTION THIS IN THE HWO. BY SATURDAY...A CLOSED UPPER LOW EJECTS
INTO THE CENTRAL PLAINS...AND A SHORTWAVE MOVES OUT OF THE BASE OF
THE LOW...CROSSING THE LOWER MS RIVER VALLEY AND NORTHEAST INTO
THE OH AND TN VALLEYS. SURFACE LOW PRESSURE AND A DEVELOPING WARM
FRONT WILL BRING A SURGE OF MOIST AIR INTO EAST KENTUCKY WITH A
SLIGHT CHANCE POPS MAKING MAKING IT INTO POINTS SOUTH OF THE HAL
ROGERS PARKWAY BY SATURDAY AFTERNOON. MODELS WITH THIS FEATURE
HAVE BEEN PRETTY CONSISTENT AND THE BEST CHANCE OF MEASURABLE
PRECIPWILL BE AFTER 00Z SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 330 AM EDT FRI APR 17 2015
THE LONG TERM DISCUSSION WILL BE ISSUED SHORTLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 150 AM EDT FRI APR 17 2015
UPPER AND MID LEVEL CLOUD COVER WILL CONTINUE TO STREAM NORTH INTO
THE AREA THROUGH THE NIGHT. SOME WEAK INSTABILITY WILL CONTINUE TO
ALLOW SOME LOWER LEVEL CLOUD COVER TO DEVELOP TONIGHT AS WELL AS A
FEW SHOWERS. THIS LOOKS TO BE MAINLY ALONG THE SOUTHERN TAF SITES.
THE NORTHERN TAF SITES MAY SEE A BREAK IN CLOUD COVER HERE AND
THERE. TOWARD DAWN...SOME IFR CLOUD COVER LOOKS TO DEVELOP ACROSS
THE AREA AND HAVE PUT THIS INTO THE TAFS. WINDS WILL REMAIN LIGHT
THROUGH THE PERIOD. HIGH PRESSURE MOVING IN LATER IN THE TAF
PERIOD WILL SHUNT THIS LOWER LEVEL CLOUD COVER TO THE EAST TOWARDS
MIDDAY FRIDAY WITH MAINLY CLEAR SKIES OR CIRRUS EXPECTED.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SHALLENBERGER
LONG TERM...DJ
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
151 AM EDT FRI APR 17 2015
.UPDATE...
ISSUED AT 150 AM EDT FRI APR 17 2015
ISSUED AN UPDATE TO INPUT THE LATEST TEMPS AND DEW POINTS ACROSS
THE AREA. PRECIP HAS NOT REDEVELOPED INTO THE AREA YET BUT
EVIDENCE OF A FEW VERY SMALL SHOWERS POPPING JUST NORTH OF THE OH
RIVER WILL JUST BE ENOUGH EVIDENCE OF WEAK INSTABILITY TO LEAVE
POPS IN FOR SLIGHT CHANCE SHOWERS THROUGH DAWN. A NEW ZFP WILL NOT
BE NEEDED WITH THIS UPDATE.
UPDATE ISSUED AT 1004 PM EDT THU APR 16 2015
PRECIP HAS DIED OUT OVER THE JKL FORECAST AREA FOR THE TIME BEING.
THERE WERE SHOWERS OCCURRING FROM WESTERN KY TO SOUTHWESTERN OH.
SHORT RANGE MODELS SUGGEST THIS AREA OF SHOWERS WILL SAG SOUTHEAST
AND ADDITIONAL SHOWER DEVELOPMENT WILL ALSO OCCUR OVER EASTERN KY
A LITTLE BEFORE DAWN. HAVE USED 20-30 PERCENT POP TO ACCOUNT FOR
THIS. MODELS ALSO SHOW A SMALL RESURGENCE OF SHOWERS LATE FRIDAY
AFTER SOME DESTABILIZATION OCCURS. IF IT OCCURS...THINK THE
ACTIVITY WOULD BE VERY ISOLATED. FORECAST SOUNDINGS SHOW VERY DRY
AIR ALOFT THAT THE CONVECTIVE CURRENTS WOULD BE RISING INTO.
WITHOUT A STRONG FOCUS/FORCING MECHANISM...DRY AIR ENTRAINMENT
COULD BE THE DEMISE OF WHAT WOULD OTHERWISE BE MORE PLENTIFUL
ACTIVITY.
UPDATE ISSUED AT 615 PM EDT THU APR 16 2015
UPDATED POPS FROM FRIDAY INTO SATURDAY. LATEST MODEL RUNS SUGGEST
THE TIME FRAME FROM LATE FRIDAY THROUGH SATURDAY WILL LIKELY BE
DRY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 306 PM EDT THU APR 16 2015
WITH THE LATEST RUN OF THE HRRR MODEL BEING A BIT OFF WITH ITS
HANDLING OF TODAYS CONVECTION...THE NAM12 WAS MODEL OF CHOICE FOR
THE SHORT TERM PORTION OF THE FORECAST. SHOWERS AND STORMS THAT
HAVE BEEN MOVING ACROSS EASTERN KENTUCKY THROUGHOUT THE DAY ARE
CURRENTLY AFFECTING THE NORTHEASTERN PORTION OF THE THE AREA. THIS
ACTIVITY IS EXPECTED TO MOVE ON OUT OF THE AREA IN THE NEXT FEW
HOURS. CURRENT RADAR INDICATES THAT ISOLATED TO SCATTERED SHOWERS
AND STORMS WILL CONTINUE TO MOVE INTO THE AREA FROM THE SOUTHWEST
DURING THE REMAINDER OF THE AFTERNOON AND EVENING HOURS. ONLY
ISOLATED ACTIVITY...IF THAT...WILL BE LEFT OVER FOR THE OVERNIGHT
HOURS. SHOWERS AND STORMS WILL BE POSSIBLE DURING THE DAY ON
FRIDAY...AS A WEAK FRONTAL BOUNDARY MOVES IN FROM THE WEST. WEAK
DISTURBANCES AHEAD OF THIS FRONT MAY ALSO KICK OFF SHOWERS AND
STORMS...BUT WITH A LACK OF INSTABILITY AND STRONG LIFT...IT
APPEARS THAT THE COVERAGE OF PRECIPITATION WILL BE SPARSE. BASED
ON THE LATEST MODEL DATA...THERE SHOULD BE LULL IN THE ACTION FROM
LATE FRIDAY AFTERNOON THROUGH EARLY SATURDAY MORNING...AS A WEAK
RIDGE OF HIGH PRESSURE BRIEFLY SETTLES OVER THE AREA.
TEMPERATURES DURING THE PERIOD WILL BE WELL ABOVE NORMAL FOR THIS
TIME OF YEAR...WITH HIGHS ON FRIDAY MAXING OUT IN THE 70S...AND
OVERNIGHT LOWS TONIGHT AND FRIDAY NIGHT BOTTOMING OUT IN THE LOW
TO MID 50S AREA WIDE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 340 PM EDT THU APR 16 2015
MAIN CONCERN DURING THE EXTENDED PERIOD IS FOCUSED ON A CUT OFF LOW
CURRENTLY OVER THE FOUR CORNERS REGION. THIS LOW IS PROGGED TO
PUSH SLOWLY EWD EARLY SATURDAY BEFORE ITS ENERGY GETS INGESTED AND
HELPS DEEPEN A NORTHERN STREAM TROUGH. THIS TROUGH WILL MOVE ALONG
THE US/CANADIAN BORDER UNTIL THE CLOSED LOW ENERGY PHASES WITH IT
AND MOVES EAST. IN ADDITION TO THE UPPER LEVEL TROUGH...A SFC LOW
IS FORECASTED TO DEVELOP SATURDAY NIGHT OVER THE PLAINS AND AHEAD
OF IT...A STRONG SURGE OF GULF MOISTURE RETURNS TO THE OH AND TN
VALLEYS. PW VALUES UP TO 1.4 INCHES ARE EXPECTED WITH THIS NEW
SURGE OF MOISTURE....WHICH ARE WELL ABOVE AVERAGE. THERE WILL BE
SOME MODERATE INSTABILITY AS WELL. THIS SYSTEM SHOULD PUSH OUT OF
KY BY MONDAY NIGHT. ON TUESDAY...A LOW THAT IS NOW CUT OFF IN THE
NORTHERN STREAM WILL UNDULATE OVER THE GREAT LAKES REGION THROUGH
THURSDAY WITH PIECES OF ENERGY WRAPPING AROUND IT. HOWEVER...THIS
SHOULDN/T CAUSE ANY ISSUES FOR KENTUCKY AS THE ENERGY APPEARS TO
STAY FURTHER NORTH UNTIL THURSDAY WHEN THE LOW STARTS SAGGING
SOUTHEASTWARD.
AT THE SFC...SATURDAY WILL BE MAINLY DRY AND WARM UNTIL LATE
AFTERNOON WHEN CHANCES FOR PRECIP BEGIN INCREASING. THE BULK OF
THE RAINFALL WILL FALL SUNDAY INTO MONDAY WHERE AT LEAST AN INCH
OF LIQUID IS LIKELY ACROSS EASTERN KENTUCKY. THERE IS ALSO A
CHANCE FOR THUNDERSTORMS DURING THIS TIME GIVEN THE MOIST AIR MASS
IN PLACE AND PLENTY OF SFC/UPPER LEVEL DYNAMICS. AS THIS SYSTEM
EXITS THE AREA MONDAY NIGHT...THINGS WILL DRY OUT AND EASTERN
KENTUCKY WILL GET A REPRIEVE FROM PRECIPITATION TUESDAY AND
WEDNESDAY. TEMPERATURES DURING THIS TIME WILL BE A BIT BELOW
NORMAL IF NOT RIGHT AT SEASONABLE LEVELS. RAIN CHANCES RETURN ON
THURSDAY AS THE LOW SAGS SOUTHEASTWARD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 150 AM EDT FRI APR 17 2015
UPPER AND MID LEVEL CLOUD COVER WILL CONTINUE TO STREAM NORTH INTO
THE AREA THROUGH THE NIGHT. SOME WEAK INSTABILITY WILL CONTINUE TO
ALLOW SOME LOWER LEVEL CLOUD COVER TO DEVELOP TONIGHT AS WELL AS A
FEW SHOWERS. THIS LOOKS TO BE MAINLY ALONG THE SOUTHERN TAF SITES.
THE NORTHERN TAF SITES MAY SEE A BREAK IN CLOUD COVER HERE AND
THERE. TOWARD DAWN...SOME IFR CLOUD COVER LOOKS TO DEVELOP ACROSS
THE AREA AND HAVE PUT THIS INTO THE TAFS. WINDS WILL REMAIN LIGHT
THROUGH THE PERIOD. HIGH PRESSURE MOVING IN LATER IN THE TAF
PERIOD WILL SHUNT THIS LOWER LEVEL CLOUD COVER TO THE EAST TOWARDS
MIDDAY FRIDAY WITH MAINLY CLEAR SKIES OR CIRRUS EXPECTED.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...AR
LONG TERM...JVM
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
925 PM CDT SAT APR 18 2015
.DISCUSSION...
MAIN WX CONCERN IS THE MCS OVER C AND N TX...MOVING E. RADAR STILL
SHOWS FAIRLY SOLID SQUALL LINE BETWEEN WHILE SOME WEAKENING IS
EXPECTED TO CONTINUE...LATEST NAM12 & HRRR SUGGEST IT CONTINUING E
THE NEXT SEVERAL HOURS...AFFECTING INLAND SE TX/C LA BETWEEN
06-09Z. THUS...HAVE INCREASED THE POPS AND QPF ACROSS THESE AREAS
FOR THE EVENING UPDATE. FOR THE REMAINDER OF THE AREA...20%
CONTINUES FOR ANY ISO SHRA/TSRA AHEAD OF THIS SYSTEM.
DML
&&
.PREV DISCUSSION... /ISSUED 734 PM CDT SAT APR 18 2015/
DISCUSSION...
FOR THE 00Z TAF PACKAGE.
AVIATION...
MAINLY ISOLATED TO SCATTERED SHOWERS ACROSS PARTS OF EAST AND
SOUTH CENTRAL LOUISIANA EARLY THIS EVENING. LATEST HRRR DEPICTS
CONVECTIVE COMPLEX OVER CENTRAL TEXAS REACHING PERHAPS AS FAR AS JUST
EAST OF THE SABINE RIVER SOMETIME AFTER MIDNIGHT BEFORE
DISSIPATING. WILL CONTINUE TO MONITOR RADAR/MODEL TRENDS THROUGH
THE EVENING. OTHERWISE...A MIX OF MVFR/VFR CIGS ACROSS THE AREA IS
EXPECTED TO LOWER INTO MVFR/IFR AS LIGHT FOG AND/OR LOWER CIGS
DEVELOP DURING THE OVERNIGHT HOURS. IMPROVEMENT TO VFR IS EXPECTED
ON SUNDAY AS DRIER AIR MOVES IN FROM THE WEST.
13
PREV DISCUSSION... /ISSUED 421 PM CDT SAT APR 18 2015/
SYNOPSIS...
LATEST UA ANALYSIS AND WV IMAGERY SHOWS SLOW-MOVING UPR LOW OVER
ERN COLORADO...WITH MOIST SWLY FLOW CONTINUING TO STREAM OVER THE
REGION. ONE IMPULSE ASSOCIATED WITH THIS SYSTEM WAS MOVING ACRS
SRN TX INTO THE WRN GULF...WITH A SECOND IMPULSE CROSSING WRN TX.
THESE TWO SYSTEMS WERE TRIGGERING STORMS ACRS THE NW/CNTL GULF
COAST AS WELL AS ACRS WRN TX. OVER THE IMMEDIATE CWA...ACTIVITY
HAS REMAINED FAIRLY SCTD...WITH A SWATH OF LT/MODT RAIN OVER THE
COASTAL WATERS...AND SCT SHRA/TSRA ACRS CNTL/WRN LA.
DISCUSSION...
OVERNIGHT CONVECTIVE COMPLEX ALLOWED THE AIRMASS TO STABILIZE
TODAY...AND ONGOING CONVECTION OVER THE GULF HAS LIMITED INFLOW.
THIS COMBINATION HAS REDUCED THE POTENTIAL FOR HEAVY RAIN AND
WIDESPREAD ACTIVITY TODAY AND LIKELY INTO TONIGHT. LOOKING AT A
COMBINATION OF RECENT HRRR RUNS AS WELL AS RAP/NAM GUIDANCE SHOWS
A DECREASING TREND DURING THE EVENING AND OVERNIGHT. ACTIVITY
ALONG THE TX COAST IS EXPECTED TO TREK E/NE BUT GRADUALLY WEAKEN
AS IT APPROACHES OUR COASTAL WATERS ZONES. LIKEWISE...THE STORMS
ACRS WRN TX WILL MOVE EAST THIS EVENING...BUT ALSO WEAKEN AS THEY
REACH THE AREA LATER TONIGHT. QPF VALUES ARE EXPECTED TO REMAIN
BELOW AN INCH THROUGH SUNDAY...AND WITH THIS IN MIND...HAVE GONE
AHEAD AND CANCELLED THE FLASH FLOOD WATCH.
DRIER MID LVL AIR WILL BEGIN TO PUSH EAST OVER THE AREA ON
SUNDAY...HELPING TO BRING A REPREIVE FROM THE RAINY PATTERN.
HOWEVER...ENOUGH MOISTURE WILL LINGER TO ALLOW FOR AT LEAST A SLT
CHC FOR A FEW SHOWERS OR TSTMS. BY SUNDAY NIGHT...A COOL FRONT
WILL MOVE THROUGH THE REGION. ENOUGH CONVERGENCE AND LIFT ARE
EXPECTED ALONG THE FRONTAL BOUNDARY TO PRODUCE A SCT BAND OF
SHOWERS AND TSTMS AS IT CROSSES THE AREA. SPC DOES HAVE THE AREA
OUTLINED IN A SLT RISK FOR SUNDAY/SUNDAY NIGHT AS INSTABILITY
LOOKS TO INCREASE AHEAD OF THE BOUNDARY. THUS AN ISOLATED STRONG
TO SEVERE STORM CANNOT BE RULED OUT ESPECIALLY ACRS THE NRN TIER
OF COUNTIES AND PARISHES.
DRY WEATHER FINALLY RETURNS ON MONDAY AND SHOULD CONTINUE INTO
TUESDAY AS HIGH PRES BUILDS INTO THE AREA. SMALL RAIN CHCS WILL
RETURN BY MIDWEEK WITH CHCS INCREASING TOWARD THE LATTER PART OF
THE WEEK. ZONAL FLOW WILL PREVAIL THROUGH THE WEEK AND LIFT
ASSOCIATED WITH EMBEDDED DISTURBANCES WILL KEEP AT LEAST CHC POPS
OVER THE AREA THURSDAY AND FRIDAY.
MARINE...
LT TO MDT SWLY FLOW WILL CONTINUE THROUGH SUNDAY WITH SHOWERS AND
TSTMS GRADUALLY DIMINISHING. A COOL FRONT WILL CROSS THE COASTAL
WATERS LATE SUNDAY NIGHT...WITH MODT OFFSHORE FLOW DEVELOPING
FOR MONDAY. EXERCISE CAUTION CONDITIONS COULD BE POSSIBLE AT TIMES
MONDAY INTO TUESDAY. WINDS WILL GRADUALLY VEER ELY TUESDAY...THEN
SELY BY WEDNESDAY AS SFC HIGH PRES MOVES EAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 63 83 60 76 / 30 30 30 10
LCH 64 82 63 79 / 20 20 20 10
LFT 65 84 64 79 / 30 20 20 10
BPT 64 82 63 79 / 20 20 20 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
PUBLIC...04
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
734 PM CDT SAT APR 18 2015
.DISCUSSION...
FOR THE 00Z TAF PACKAGE.
&&
.AVIATION...
MAINLY ISOLATED TO SCATTERED SHOWERS ACROSS PARTS OF EAST AND
SOUTH CENTRAL LOUISIANA EARLY THIS EVENING. LATEST HRRR DEPICTS
CONVECTIVE COMPLEX OVER CENTRAL TEXAS REACHING PERHAPS AS FAR AS JUST
EAST OF THE SABINE RIVER SOMETIME AFTER MIDNIGHT BEFORE
DISSIPATING. WILL CONTINUE TO MONITOR RADAR/MODEL TRENDS THROUGH
THE EVENING. OTHERWISE...A MIX OF MVFR/VFR CIGS ACROSS THE AREA IS
EXPECTED TO LOWER INTO MVFR/IFR AS LIGHT FOG AND/OR LOWER CIGS
DEVELOP DURING THE OVERNIGHT HOURS. IMPROVEMENT TO VFR IS EXPECTED
ON SUNDAY AS DRIER AIR MOVES IN FROM THE WEST.
13
&&
.PREV DISCUSSION... /ISSUED 421 PM CDT SAT APR 18 2015/
SYNOPSIS...
LATEST UA ANALYSIS AND WV IMAGERY SHOWS SLOW-MOVING UPR LOW OVER
ERN COLORADO...WITH MOIST SWLY FLOW CONTINUING TO STREAM OVER THE
REGION. ONE IMPULSE ASSOCIATED WITH THIS SYSTEM WAS MOVING ACRS
SRN TX INTO THE WRN GULF...WITH A SECOND IMPULSE CROSSING WRN TX.
THESE TWO SYSTEMS WERE TRIGGERING STORMS ACRS THE NW/CNTL GULF
COAST AS WELL AS ACRS WRN TX. OVER THE IMMEDIATE CWA...ACTIVITY
HAS REMAINED FAIRLY SCTD...WITH A SWATH OF LT/MODT RAIN OVER THE
COASTAL WATERS...AND SCT SHRA/TSRA ACRS CNTL/WRN LA.
DISCUSSION...
OVERNIGHT CONVECTIVE COMPLEX ALLOWED THE AIRMASS TO STABILIZE
TODAY...AND ONGOING CONVECTION OVER THE GULF HAS LIMITED INFLOW.
THIS COMBINATION HAS REDUCED THE POTENTIAL FOR HEAVY RAIN AND
WIDESPREAD ACTIVITY TODAY AND LIKELY INTO TONIGHT. LOOKING AT A
COMBINATION OF RECENT HRRR RUNS AS WELL AS RAP/NAM GUIDANCE SHOWS
A DECREASING TREND DURING THE EVENING AND OVERNIGHT. ACTIVITY
ALONG THE TX COAST IS EXPECTED TO TREK E/NE BUT GRADUALLY WEAKEN
AS IT APPROACHES OUR COASTAL WATERS ZONES. LIKEWISE...THE STORMS
ACRS WRN TX WILL MOVE EAST THIS EVENING...BUT ALSO WEAKEN AS THEY
REACH THE AREA LATER TONIGHT. QPF VALUES ARE EXPECTED TO REMAIN
BELOW AN INCH THROUGH SUNDAY...AND WITH THIS IN MIND...HAVE GONE
AHEAD AND CANCELLED THE FLASH FLOOD WATCH.
DRIER MID LVL AIR WILL BEGIN TO PUSH EAST OVER THE AREA ON
SUNDAY...HELPING TO BRING A REPREIVE FROM THE RAINY PATTERN.
HOWEVER...ENOUGH MOISTURE WILL LINGER TO ALLOW FOR AT LEAST A SLT
CHC FOR A FEW SHOWERS OR TSTMS. BY SUNDAY NIGHT...A COOL FRONT
WILL MOVE THROUGH THE REGION. ENOUGH CONVERGENCE AND LIFT ARE
EXPECTED ALONG THE FRONTAL BOUNDARY TO PRODUCE A SCT BAND OF
SHOWERS AND TSTMS AS IT CROSSES THE AREA. SPC DOES HAVE THE AREA
OUTLINED IN A SLT RISK FOR SUNDAY/SUNDAY NIGHT AS INSTABILITY
LOOKS TO INCREASE AHEAD OF THE BOUNDARY. THUS AN ISOLATED STRONG
TO SEVERE STORM CANNOT BE RULED OUT ESPECIALLY ACRS THE NRN TIER
OF COUNTIES AND PARISHES.
DRY WEATHER FINALLY RETURNS ON MONDAY AND SHOULD CONTINUE INTO
TUESDAY AS HIGH PRES BUILDS INTO THE AREA. SMALL RAIN CHCS WILL
RETURN BY MIDWEEK WITH CHCS INCREASING TOWARD THE LATTER PART OF
THE WEEK. ZONAL FLOW WILL PREVAIL THROUGH THE WEEK AND LIFT
ASSOCIATED WITH EMBEDDED DISTURBANCES WILL KEEP AT LEAST CHC POPS
OVER THE AREA THURSDAY AND FRIDAY.
MARINE...
LT TO MDT SWLY FLOW WILL CONTINUE THROUGH SUNDAY WITH SHOWERS AND
TSTMS GRADUALLY DIMINISHING. A COOL FRONT WILL CROSS THE COASTAL
WATERS LATE SUNDAY NIGHT...WITH MODT OFFSHORE FLOW DEVELOPING
FOR MONDAY. EXERCISE CAUTION CONDITIONS COULD BE POSSIBLE AT TIMES
MONDAY INTO TUESDAY. WINDS WILL GRADUALLY VEER ELY TUESDAY...THEN
SELY BY WEDNESDAY AS SFC HIGH PRES MOVES EAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 63 83 60 76 / 40 20 30 10
LCH 64 82 63 79 / 30 10 20 10
LFT 65 84 64 79 / 50 20 20 10
BPT 64 82 63 79 / 30 20 20 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...13
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
151 PM CDT FRI APR 17 2015
.DISCUSSION...
17/18Z TAF ISSUANCE.
&&
.AVIATION...
MUCH IMPROVED CONDITIONS TODAY COMPARED TO YESTERDAY. MAINLY
SCT/BKN CUMULUS OVER THE REGION...WITH PREVAILING VFR AND OCNL
MVFR CIGS AT TAF SITES EARLY THIS AFTN. THESE CONDITIONS WILL
CONTINUE INTO THE EVENING...WITH CONDITIONS AGAIN DETERIORATING
OVERNIGHT FROM WEST TO EAST AS THE NEXT DISTURBANCE APPROACHES.
CIGS WILL LOWER TO LOW END MVFR OR IFR AFTER 06Z...WITH SHRA/TSRA
DEVELOPING. CONVECTION WILL BECOME MORE WIDESPREAD THROUGH
SATURDAY MORNING...WITH GUSTY WINDS AND HEAVY RAIN EXPECTED WITHIN
SOME OF THE STRONGER STORMS. 24
&&
.PREV DISCUSSION... /ISSUED 1050 AM CDT FRI APR 17 2015/
DISCUSSION...
AFTER A FUN DAY YESTERDAY...LOCAL 88DS ARE REFRESHINGLY QUIET THIS
MORNING WITH MAINLY JUST RAINS ASSOCIATED WITH A DEPARTING
DISTURBANCE ALOFT EXITING THE ERN COASTAL WATERS AND POSSIBLY
BRUSHING LOWER ACADIANA. 12Z KLCH SOUNDING SHOWED A MUCH DRIER
AIRMASS IN PLACE OVER THE REGION TODAY...WHILE THE MODIFIED
SOUNDING SHOWED SIMILAR INSTABILITY TO THURSDAY. PLAYING TO OUR
ADVANTAGE TODAY IS A RELATIVE LACK OF APPROACHING DISTURBANCES
ROUNDING THE UPPER LOW OVER THE FOUR CORNERS REGION. HOWEVER GIVEN
THAT WE ARE STILL REASONABLY MOIST AND FAIRLY UNSTABLE...DAYTIME
HEATING OR PERHAPS SOME LINGERING BOUNDARIES FROM EARLIER
CONVECTION COULD STILL SPARK SOME SHOWERS AND STORMS ESPECIALLY
THIS AFTERNOON.
DESPITE WHAT LOOKS LIKE A LACK OF PRECIP TODAY...STILL EXPECTING
ANOTHER HEAVY RAINFALL EVENT BEGINNING TONIGHT AND RUNNING INTO
SATURDAY. GIVEN THE FLOODING WHICH OCCURRED YESTERDAY AND THE
SATURATED GROUNDS LEFT BEHIND FROM ALL THE RAIN...EXTENDED THE
INHERITED FLASH FLOOD WATCH THROUGH LATE TOMORROW AFTERNOON.
ELSEWHERE JUST TWEAKED GRIDS/ZONES BASED ON LATEST OBS/TRENDS...
UPDATE ALREADY OUT.
25
PREV DISCUSSION... /ISSUED 616 AM CDT FRI APR 17 2015/
AVIATION...SINCE MIDNIGHT CONVECTIVE ACTIVITY HAS DECREASED
SIGNIFICANTLY. RADAR NOW SHOWING JUST A FEW SHOWERS AND
THUNDERSTORMS AND THESE OFFSHORE OVER THE NEAR COASTAL WATERS.
TODAY LOOKS TO WITH MUCH LESS CONVECTION OVER THE AREA AS SOME
SHARPLY DRIER MID LEVEL AIR ADVECTS INTO THE REGION. MODELS
SUGGESTING A RAMPING UP OF PRECIP OVERNIGHT AS ANOTHER UPPER LEVEL
DISTURBANCE APPROACHES. ALTOCU CLOUDS AT AROUND 10KT FT CURRENTLY
OVER AREA. WILL SEE LOWER CLOUDS DEVELOP AS THE MORNING
PROGRESSES BUT WILL MAINTAIN THESE WITHIN VFR. 25
PREV DISCUSSION... /ISSUED 335 AM CDT FRI APR 17 2015/
DISCUSSION...POPS AND HEAVY RAIN WILL BE THE MAIN FORECAST ISSUES
OVER THE NEXT 48 HOURS. WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY
YESTERDAY AND OVERNIGHT WAS BEGINNING TO DECREASE AS OF 08Z. THE
LATEST HRRR CONFIRMS THIS WITH ACTIVITY DECREASING SIGNIFICANT
LATER THIS MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST
AREA. WILL CONTINUE WITH FFA FOR NOW...BUT MAY CANCEL EARLY IF
WEAKENING TREND CONTINUES. WILL TAPER POPS TO MID RANGE FOR THIS
AFTERNOON.
MODELS HAVE BEEN CONSISTENT IN LIFTING UPPER TROUGH NE THROUGH THE
WEEKEND. ALSO...APPEARS THAT NEXT ROUND OF SHOWERS AND THUNDERSTORMS
WILL BEGIN LATE TONIGHT AND BECOME MORE WIDESPREAD ON SATURDAY.
WILL LIKELY NEED TO REISSUE FFA FOR TONIGHT AND SATURDAY.
AFTER SATURDAY...A MUCH NEEDED PATTERN CHANGE IS FORECASTED. WEAK
UPPER RIDGE SHOULD DEVELOP OVER THE GULF COAST STATES. A FRONTAL
BOUNDARY SHOULD MOVE THROUGH THE AREA BY SUNDAY NIGHT AND THIS
WILL LIKELY BRING DRY WEATHER FOR EARLY NEXT WEEK. FRONT IS
FORECASTED TO STALL OVER THE GULF AND RETURN NORTH LATE IN THE
WEEK. AT THIS TIME...WILL KEEP LOW POPS IN THE FORECAST ALTHOUGH
LATEST MODELS ARE SHOWING A DEEPER MOISTURE PROFILE THIS CYCLE.
MARINE...PERIODIC SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH
THE EARLY PART OF THE WEEKEND. OTHERWISE HIGH PRESSURE OVER THE
EASTERN GULF AND LOW PRESSURE OVER WEST TEXAS WILL MAINTAIN ONSHORE
FLOW THROUGH SUNDAY. MODELS CONTINUE TO BRING FRONT INTO THE
NORTHERN GULF SUNDAY NIGHT ALLOWING FOR A BRIEF PERIOD OF OFFSHORE
FLOW. WEAK TO MODERATE EASTERLY FLOW IS ANTICIPATED FOR EARLY
NEXT WEEK AS HIGH PRESSURE SETTLES OVER THE SE U.S.
AP
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 81 66 77 62 / 30 70 80 40
LCH 82 67 77 64 / 40 70 80 40
LFT 81 69 78 65 / 40 60 90 40
BPT 82 67 79 64 / 40 70 70 40
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR LAZ027>033-
041>045-052>055-073-074.
TX...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR TXZ180-201-215-
216-259>262.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1050 AM CDT FRI APR 17 2015
.DISCUSSION...
AFTER A FUN DAY YESTERDAY...LOCAL 88DS ARE REFRESHINGLY QUIET THIS
MORNING WITH MAINLY JUST RAINS ASSOCIATED WITH A DEPARTING
DISTURBANCE ALOFT EXITING THE ERN COASTAL WATERS AND POSSIBLY
BRUSHING LOWER ACADIANA. 12Z KLCH SOUNDING SHOWED A MUCH DRIER
AIRMASS IN PLACE OVER THE REGION TODAY...WHILE THE MODIFIED
SOUNDING SHOWED SIMILAR INSTABILITY TO THURSDAY. PLAYING TO OUR
ADVANTAGE TODAY IS A RELATIVE LACK OF APPROACHING DISTURBANCES
ROUNDING THE UPPER LOW OVER THE FOUR CORNERS REGION. HOWEVER GIVEN
THAT WE ARE STILL REASONABLY MOIST AND FAIRLY UNSTABLE...DAYTIME
HEATING OR PERHAPS SOME LINGERING BOUNDARIES FROM EARLIER
CONVECTION COULD STILL SPARK SOME SHOWERS AND STORMS ESPECIALLY
THIS AFTERNOON.
DESPITE WHAT LOOKS LIKE A LACK OF PRECIP TODAY...STILL EXPECTING
ANOTHER HEAVY RAINFALL EVENT BEGINNING TONIGHT AND RUNNING INTO
SATURDAY. GIVEN THE FLOODING WHICH OCCURRED YESTERDAY AND THE
SATURATED GROUNDS LEFT BEHIND FROM ALL THE RAIN...EXTENDED THE
INHERITED FLASH FLOOD WATCH THROUGH LATE TOMORROW AFTERNOON.
ELSEWHERE JUST TWEAKED GRIDS/ZONES BASED ON LATEST OBS/TRENDS...
UPDATE ALREADY OUT.
25
&&
.PREV DISCUSSION... /ISSUED 616 AM CDT FRI APR 17 2015/
AVIATION...SINCE MIDNIGHT CONVECTIVE ACTIVITY HAS DECREASED
SIGNIFICANTLY. RADAR NOW SHOWING JUST A FEW SHOWERS AND
THUNDERSTORMS AND THESE OFFSHORE OVER THE NEAR COASTAL WATERS.
TODAY LOOKS TO WITH MUCH LESS CONVECTION OVER THE AREA AS SOME
SHARPLY DRIER MID LEVEL AIR ADVECTS INTO THE REGION. MODELS
SUGGESTING A RAMPING UP OF PRECIP OVERNIGHT AS ANOTHER UPPER LEVEL
DISTURBANCE APPROACHES. ALTOCU CLOUDS AT AROUND 10KT FT CURRENTLY
OVER AREA. WILL SEE LOWER CLOUDS DEVELOP AS THE MORNING
PROGRESSES BUT WILL MAINTAIN THESE WITHIN VFR.
PREV DISCUSSION... /ISSUED 335 AM CDT FRI APR 17 2015/
DISCUSSION...POPS AND HEAVY RAIN WILL BE THE MAIN FORECAST ISSUES
OVER THE NEXT 48 HOURS. WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY
YESTERDAY AND OVERNIGHT WAS BEGINNING TO DECREASE AS OF 08Z. THE
LATEST HRRR CONFIRMS THIS WITH ACTIVITY DECREASING SIGNIFICANT
LATER THIS MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST
AREA. WILL CONTINUE WITH FFA FOR NOW...BUT MAY CANCEL EARLY IF
WEAKENING TREND CONTINUES. WILL TAPER POPS TO MID RANGE FOR THIS
AFTERNOON.
MODELS HAVE BEEN CONSISTENT IN LIFTING UPPER TROUGH NE THROUGH THE
WEEKEND. ALSO...APPEARS THAT NEXT ROUND OF SHOWERS AND THUNDERSTORMS
WILL BEGIN LATE TONIGHT AND BECOME MORE WIDESPREAD ON SATURDAY.
WILL LIKELY NEED TO REISSUE FFA FOR TONIGHT AND SATURDAY.
AFTER SATURDAY...A MUCH NEEDED PATTERN CHANGE IS FORECASTED. WEAK
UPPER RIDGE SHOULD DEVELOP OVER THE GULF COAST STATES. A FRONTAL
BOUNDARY SHOULD MOVE THROUGH THE AREA BY SUNDAY NIGHT AND THIS
WILL LIKELY BRING DRY WEATHER FOR EARLY NEXT WEEK. FRONT IS
FORECASTED TO STALL OVER THE GULF AND RETURN NORTH LATE IN THE
WEEK. AT THIS TIME...WILL KEEP LOW POPS IN THE FORECAST ALTHOUGH
LATEST MODELS ARE SHOWING A DEEPER MOISTURE PROFILE THIS CYCLE.
MARINE...PERIODIC SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH
THE EARLY PART OF THE WEEKEND. OTHERWISE HIGH PRESSURE OVER THE
EASTERN GULF AND LOW PRESSURE OVER WEST TEXAS WILL MAINTAIN ONSHORE
FLOW THROUGH SUNDAY. MODELS CONTINUE TO BRING FRONT INTO THE
NORTHERN GULF SUNDAY NIGHT ALLOWING FOR A BRIEF PERIOD OF OFFSHORE
FLOW. WEAK TO MODERATE EASTERLY FLOW IS ANTICIPATED FOR EARLY
NEXT WEEK AS HIGH PRESSURE SETTLES OVER THE SE U.S.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 81 66 77 62 / 30 70 80 40
LCH 82 67 77 64 / 40 70 80 40
LFT 81 69 78 65 / 40 60 90 40
BPT 82 67 79 64 / 40 70 70 40
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR LAZ027>033-
041>045-052>055-073-074.
TX...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR TXZ180-201-215-
216-259>262.
GM...NONE.
&&
$$
PUBLIC...04
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
616 AM CDT FRI APR 17 2015
.AVIATION...SINCE MIDNIGHT CONVECTIVE ACTIVITY HAS DECREASED
SIGNIFICANTLY. RADAR NOW SHOWING JUST A FEW SHOWERS AND
THUNDERSTORMS AND THESE OFFSHORE OVER THE NEAR COASTAL WATERS.
TODAY LOOKS TO WITH MUCH LESS CONVECTION OVER THE AREA AS SOME
SHARPLY DRIER MID LEVEL AIR ADVECTS INTO THE REGION. MODELS
SUGGESTING A RAMPING UP OF PRECIP OVERNIGHT AS ANOTHER UPPER LEVEL
DISTURBANCE APPROACHES. ALTOCU CLOUDS AT AROUND 10KT FT CURRENTLY
OVER AREA. WILL SEE LOWER CLOUDS DEVELOP AS THE MORNING
PROGRESSES BUT WILL MAINTAIN THESE WITHIN VFR.
&&
.PREV DISCUSSION... /ISSUED 335 AM CDT FRI APR 17 2015/
DISCUSSION...POPS AND HEAVY RAIN WILL BE THE MAIN FORECAST ISSUES
OVER THE NEXT 48 HOURS. WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY
YESTERDAY AND OVERNIGHT WAS BEGINNING TO DECREASE AS OF 08Z. THE
LATEST HRRR CONFIRMS THIS WITH ACTIVITY DECREASING SIGNIFICANT
LATER THIS MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST
AREA. WILL CONTINUE WITH FFA FOR NOW...BUT MAY CANCEL EARLY IF
WEAKENING TREND CONTINUES. WILL TAPER POPS TO MID RANGE FOR THIS
AFTERNOON.
MODELS HAVE BEEN CONSISTENT IN LIFTING UPPER TROUGH NE THROUGH THE
WEEKEND. ALSO...APPEARS THAT NEXT ROUND OF SHOWERS AND THUNDERSTORMS
WILL BEGIN LATE TONIGHT AND BECOME MORE WIDESPREAD ON SATURDAY.
WILL LIKELY NEED TO REISSUE FFA FOR TONIGHT AND SATURDAY.
AFTER SATURDAY...A MUCH NEEDED PATTERN CHANGE IS FORECASTED. WEAK
UPPER RIDGE SHOULD DEVELOP OVER THE GULF COAST STATES. A FRONTAL
BOUNDARY SHOULD MOVE THROUGH THE AREA BY SUNDAY NIGHT AND THIS
WILL LIKELY BRING DRY WEATHER FOR EARLY NEXT WEEK. FRONT IS
FORECASTED TO STALL OVER THE GULF AND RETURN NORTH LATE IN THE
WEEK. AT THIS TIME...WILL KEEP LOW POPS IN THE FORECAST ALTHOUGH
LATEST MODELS ARE SHOWING A DEEPER MOISTURE PROFILE THIS CYCLE.
MARINE...PERIODIC SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH
THE EARLY PART OF THE WEEKEND. OTHERWISE HIGH PRESSURE OVER THE
EASTERN GULF AND LOW PRESSURE OVER WEST TEXAS WILL MAINTAIN ONSHORE
FLOW THROUGH SUNDAY. MODELS CONTINUE TO BRING FRONT INTO THE
NORTHERN GULF SUNDAY NIGHT ALLOWING FOR A BRIEF PERIOD OF OFFSHORE
FLOW. WEAK TO MODERATE EASTERLY FLOW IS ANTICIPATED FOR EARLY
NEXT WEEK AS HIGH PRESSURE SETTLES OVER THE SE U.S.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 80 66 77 62 / 60 70 80 40
LCH 81 67 77 64 / 70 70 80 40
LFT 80 69 78 65 / 70 60 90 40
BPT 81 67 79 64 / 70 70 70 40
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR LAZ027>033-
041>045-052>055-073-074.
TX...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR TXZ180-201-
215-216-259>262.
GM...NONE.
&&
$$
AVIATION...23
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1036 AM EDT FRI APR 17 2015
.SYNOPSIS...
A SURFACE TROUGH WILL PASS THROUGH THE REGION TODAY. HIGH
PRESSURE WILL RETURN FOR SATURDAY. THE HIGH WILL MOVE OFF THE
COAST SUNDAY AND A WARM FRONT WILL MOVE INTO THE AREA SUNDAY NIGHT
INTO MONDAY. A COLD FRONT WILL PASS THROUGH LATE MONDAY INTO
MONDAY NIGHT BEFORE HIGH PRESSURE RETURNS FOR THE MIDDLE PORTION
OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
14Z MSAS AND SURFACE ANALYSIS INDICATES SURFACE TROUGH HAS REACHED
WRN PA AND FAR EASTERN OH. THIS TROUGH WILL MOVE THROUGH THE
FORECAST AREA THIS AFTN. SOME SCATTERED AREAS OF LIGHT RAIN
SHOWERS AHEAD OF THIS BOUNDARY HAVE MOVED INTO WESTERN MD AND
EASTERN WV.
JUST TO THE EAST...SKIES HAVE CLEARED OVER MOST AREAS ALONG AND
EAST OF THE SHENANDOAH VALLEY...ALLOWING TEMPS TO REACH WELL INTO
THE 60S. TEMPS SHOULD RISE INTO THE L-M 70S BY AFTERNOON. NW FLOW
WILL DRAW IN COLD DRY AIR ALOFT TODAY. THIS WILL CAUSE LAPSE RATES
TO INCREASE. SHOWERS ARE EXPECTED TO FORM ALONG THE SFC TROUGH BY
EARLY AFTERNOON. LATEST HRRR GUIDANCE SHOWS CONVECTIVE SHOWERS
INCREASING IN COVERAGE BY EARLY AFTN IN THE SHENANDOAH VALLEY AND
SPREADING EWD TOWARD THE BALTIMORE/WASHINGTON METRO AREAS. WARMER
SFC TEMPS AND DECENT BOUNDARY LAYER MIXING WILL ALLOW SEVERAL HUNDRED
J/KG OF CAPE. A FEW THUNDERSTORMS ARE POSSIBLE LATE THIS
AFTERNOON AND EARLY EVENING. CLEARING IS EXPECTED BEHIND THE SFC
TROUGH INTO THE EVENING.
HIGH PRESSURE WILL MOVE INTO THE REGION TONIGHT AND PERSIST
SATURDAY. FCST MIN TEMPS INT HE 50S EXPECTED TONIGHT. FULL SUNSHINE
WILL ALLOW TEMPS TO RISE INTO THE UPPER 70S TO NEAR 80 IN THE METROS
SATURDAY.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
REGION REMAINS ON THE SOUTHERN PERIPHERY OF HIGH PRESSURE
CENTERED JUST NORTH OF THE GREAT LAKES. RIDGING BUILDS IN
ALOFT...WITH THE RIDGE AXIS SHIFTING ACROSS THE MID ATLANTIC BY
SUN MORNING. OVERALL PATTERN WILL KEEP THE AREA DRY. CLOUDS WILL
BEGIN TO INCREASE FROM THE SOUTHWEST AHEAD OF THE NEXT FRONTAL
SYSTEM. WINDS WILL LIGHTEN AND BECOME NE OVERNIGHT AS THE HIGH
BUILDS SOUTH.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
00Z MODEL SUITE CONTINUING WITH A SLOWER PROGRESSION OF THE NEXT
FRONTAL SYSTEM...AND THE ARRIVAL TIMING OF THE PCPN. RIDGE AXIS
SHIFTS EAST DURING THE DAY SUNDAY AS A DEEPENING CLOSED LOW OVER
THE NORTHERN PLAINS BUILDS EAST. BROAD LOW PRESSURE AT THE SFC
OVER THE CENTRAL PLAINS BECOMES ORGANIZED DURING HE DAY AS WELL AS
IT MOVES INTO THE WESTERN GREAT LAKES...GRADUALLY LIFTING THE
ASSOCIATED WARM FRONT TO THE NORTH AND INTO THE MID ATLANTIC.
GENERAL CONSENSUS AMONGST THE MODELS KEEPS THE WARM FRONT AT OR
JUST SOUTH OF THE VA/NC BORDER THRU SUN NIGHT...WITH PCPN
OCCURRING SUN-SUN NIGHT AS A RESULT OF DYNAMIC FORCING ALOFT WITH
MULTIPLE MID LVL SHORTWAVES AND STRENGTHENING LLJ AND 250MB JET.
PWATS INCRSG TO BETWEEN 1.2-1.4 IN...WHICH COULD RESULT IN PERIODS
OF MODERATE TO HEAVY RAIN.
SOME UNCERTAINTY STILL EXISTS WITH PCPN TIMING AND TSTM DEVELOPMENT
ON MONDAY. WARM FRONT LOOKS TO BE NEAR THE VA/NC BORDER EARLY
MONDAY...THEN GRADUALLY LIFTING NORTH DURING THE DAY. HOW QUICKLY IT
CAN CLEAR THE CWA AND WARM SECTOR THE AREA WILL AFFECT THE EXTENT OF
TSTM DEVELOPMENT...AND AS SUCH WILL CONTINUE TO MENTION SLIGHT CHC T
FOR MOST OF THE AREA NOW...AND CHC OVER CENTRAL VA WHERE THE BEST
DAYTIME HEATING SHOULD OCCUR. KEPT NORTHEASTERN MD OUT OF THE
THUNDER MENTION FOR NOW WITH COOLER TEMPS EXPECTED. IN
ADDITION...THINKING THERE SHOULD BE TWO ROUNDS OF PCPN...THE INITIAL
SUN NIGHT...WITH A BREAK AT SOME POINT MONDAY WITH THE NEXT ROUND
MOVING IN AHEAD OF THE APPROACHING COLD FRONT. THE COLD FRONT PUSHES
THROUGH MONDAY NIGHT...WITH PCPN CLEARING TO THE EAST BY EARLY TUES
MORNING.
SFC HIGH PRESSURE BUILDS IN FROM THE SOUTH IN THE WAKE OF THE FRONT
THRU WED...QUICKLY PROGRESSING OFFSHORE BY THURS...AND RESULTING IN
BRIEF PERIOD OF DRY WX. THE REGION REMAINS POSITIONED AT THE BASE OF
A BROAD UPPER LVL CLOSED LOW...WHICH WILL SEND THROUGH THE NEXT COLD
FRONT MIDWEEK...BRINGING THE NEXT CHC FOR PCPN. NEAR NORMAL TEMPS
EXPECTED THROUGH THE PERIOD ON WLY FLOW.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
VFR WITH DRY CONDITIONS EXPECTED AT THE TERMINALS THROUGH NOON. A
SFC TROUGH ACROSS THE OHIO VALLEY WILL MOVE FROM WEST TO EAST
ACROSS THE TERMINALS THIS AFTERNOON. SHOWERS WILL REDEVELOP. AN
ISOLATED TS IS POSSIBLE MAINLY CHO-DCA. IN TERMS OF WINDS...SW
FLOW IN THE MORNING WITH POTENTIAL FOR GUSTS TO AROUND 15 KT.
GUSTS ARE EXPECTED TO DIMINISH BY EARLY AFTERNOON. WINDS WILL
SHIFT TO THE W THIS AFTN AND EVENTUALLY TO THE NW BY LATE
AFTERNOON.
VFR CONDITIONS EXPECTED TONIGHT AND SATURDAY.
VFR CONDITIONS SAT NIGHT-SUN. SUB-VFR CONDITIONS BCMG LIKELY BY
SUN NIGHT WITH WIDESPREAD RAIN. PERIODS OF HEAVIER RAIN COULD DROP
CONDITIONS TO SUB-IFR SUN NIGHT. LLWS CONCERNS PSBL MON MORNING
WITH SE WINDS 40-50 KTS AT 2KFT...SHIFTING TO THE SOUTH DURING THE
MORNING.
SUB-VFR CONDITIONS REMAIN PSBL DURING THE DAY MON AS A COLD FRONT
BRINGS ANOTHER ROUND OF PCPN. SLIGHT CHC OF THUNDER CURRENTLY FOR
THE TAF SITES...MAINLY MON AFTN/EVENING. WIND SHIFT EXPECTED MON
EVENING WITH FRONTAL PASSAGE.
VFR CONDITIONS MON NIGHT AS THE PCPN TAPERS OFF...LASTING THRU WED.
&&
.MARINE...
SCA HAS BEEN CANCELLED...AS WINDS HAVE DIMINISHED TO AROUND 10KT
OVER MOST OF THE WATERS. A SFC TROUGH WILL CROSS THE WATERS THIS
AFTERNOON. SHOWERS ARE EXPECTED AND AN ISOLATED THUNDERSTORM IS
POSSIBLE MAINLY ACROSS THE SOUTHERN WATERS. S WINDS BECOME W-NW
THIS EVENING. HIGH PRESSURE BUILDS IN TONIGHT AND SATURDAY.
GENERALLY SUB-SCA CONDITIONS SAT NIGHT-SUN. SCA CONDITIONS PSBL
BY SUN NIGHT WITH INCRSG ELY FLOW. SCA CONDITIONS LAST DURING THE
DAY MON AHEAD OF THE COLD FRONT...BCMG SUB-SCA MON EVENING. GUSTS
TO 20 KTS PSBL AGAIN TUES AFTN IN THE WAKE OF THE FRONT.
&&
.EQUIPMENT...
AUDIO DEGRADATION AT THE NOAA WEATHER RADIO CHARLOTTESVILLE
TRANSMITTER IS EXPECTED TO CONTINUE THROUGH THIS WEEKEND.
TECHNICIANS ARE SCHEDULED TO PERFORM MAINTENANCE AT THE
TRANSMITTER SITE MONDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SEARS/KCS
NEAR TERM...HAS/KCS
SHORT TERM...HAS
LONG TERM...SEARS
AVIATION...SEARS/HAS/KCS
MARINE...SEARS/HAS/KCS
EQUIPMENT...KCS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
751 AM EDT FRI APR 17 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO MOVE OFF THE COAST THIS MORNING. A
SURFACE TROUGH WILL PASS THROUGH THE REGION TODAY AND HIGH
PRESSURE WILL RETURN FOR SATURDAY. THE HIGH WILL MOVE OFF THE
COAST SUNDAY AND A WARM FRONT WILL MOVE INTO THE AREA SUNDAY NIGHT
INTO MONDAY. A COLD FRONT WILL PASS THROUGH LATE MONDAY INTO
MONDAY NIGHT BEFORE HIGH PRESSURE RETURNS FOR THE MIDDLE PORTION
OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
HIGH PRESSURE WILL PERSIST OFF THE EAST COAST THIS MORNING. AN
UPPER LEVEL TROUGH WILL MOVE ACROSS THE MID-ATLANTIC THIS
MORNING...FOLLOWED BY A SURFACE TROUGH LATER TODAY.
EARLIER SHOWER ACTIVITY HAS MOVED INTO THE DELMARVA REGION. SOME
SCATTERED AREAS OF LIGHT RAIN ASSOCIATED WITH THE UPPER TROUGH TO
OUR WEST ARE APPROACHING THE HIGHLANDS. FURTHER EAST... A PERIOD
OF DRY CONDITIONS IS EXPECTED THIS MORNING BETWEEN THE EXITING
UPPER LEVEL DISTURBANCE AND INCOMING SFC TROUGH.
TEMPS SHOULD RISE INTO THE L-M 70S BY AFTERNOON. NW FLOW WILL DRAW
IN COLD DRY AIR ALOFT TODAY. THIS WILL CAUSE LAPSE RATES TO INCREASE
AND SHOWERS ARE EXPECTED TO FORM ALONG THE SFC TROUGH BY EARLY
AFTERNOON. LATEST HRRR GUIDANCE SHOWS A BKN LINE OF CONVECTIVE
SHOWERS TO MOVE E-SE THROUGH THE AFTERNOON. AS THE SHOWERS MOVE
PAST I-66...WARMER SFC TEMPS AND DECENT BOUNDARY LAYER MIXING WILL
ALLOW A FEW HUNDRED J/KG OF CAPE. A FEW THUNDERSTORMS ARE POSSIBLE
SOUTH OF I-66/MD RT50 LATE THIS AFTERNOON AND EARLY EVENING.
CLEARING IS EXPECTED BEHIND THE SFC TROUGH INTO THE EVENING.
HIGH PRESSURE WILL MOVE INTO THE REGION TONIGHT AND PERSIST
SATURDAY. FCST MIN TEMPS INT HE 50S EXPECTED TONIGHT. FULL SUNSHINE
WILL ALLOW TEMPS TO RISE INTO THE UPPER 70S TO NEAR 80 IN THE METROS
SATURDAY.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
REGION REMAINS ON THE SOUTHERN PERIPHERY OF HIGH PRESSURE
CENTERED JUST NORTH OF THE GREAT LAKES. RIDGING BUILDS IN
ALOFT...WITH THE RIDGE AXIS SHIFTING ACROSS THE MID ATLANTIC BY
SUN MORNING. OVERALL PATTERN WILL KEEP THE AREA DRY. CLOUDS WILL
BEGIN TO INCREASE FROM THE SOUTHWEST AHEAD OF THE NEXT FRONTAL
SYSTEM. WINDS WILL LIGHTEN AND BECOME NE OVERNIGHT AS THE HIGH
BUILDS SOUTH.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
00Z MODEL SUITE CONTINUING WITH A SLOWER PROGRESSION OF THE NEXT
FRONTAL SYSTEM...AND THE ARRIVAL TIMING OF THE PCPN. RIDGE AXIS
SHIFTS EAST DURING THE DAY SUNDAY AS A DEEPENING CLOSED LOW OVER
THE NORTHERN PLAINS BUILDS EAST. BROAD LOW PRESSURE AT THE SFC
OVER THE CENTRAL PLAINS BECOMES ORGANIZED DURING HE DAY AS WELL AS
IT MOVES INTO THE WESTERN GREAT LAKES...GRADUALLY LIFTING THE
ASSOCIATED WARM FRONT TO THE NORTH AND INTO THE MID ATLANTIC.
GENERAL CONSENSUS AMONGST THE MODELS KEEPS THE WARM FRONT AT OR
JUST SOUTH OF THE VA/NC BORDER THRU SUN NIGHT...WITH PCPN
OCCURRING SUN-SUN NIGHT AS A RESULT OF DYNAMIC FORCING ALOFT WITH
MULTIPLE MID LVL SHORTWAVES AND STRENGTHENING LLJ AND 250MB JET.
PWATS INCRSG TO BETWEEN 1.2-1.4 IN...WHICH COULD RESULT IN PERIODS
OF MODERATE TO HEAVY RAIN.
SOME UNCERTAINTY STILL EXISTS WITH PCPN TIMING AND TSTM DEVELOPMENT
ON MONDAY. WARM FRONT LOOKS TO BE NEAR THE VA/NC BORDER EARLY
MONDAY...THEN GRADUALLY LIFTING NORTH DURING THE DAY. HOW QUICKLY IT
CAN CLEAR THE CWA AND WARM SECTOR THE AREA WILL AFFECT THE EXTENT OF
TSTM DEVELOPMENT...AND AS SUCH WILL CONTINUE TO MENTION SLIGHT CHC T
FOR MOST OF THE AREA NOW...AND CHC OVER CENTRAL VA WHERE THE BEST
DAYTIME HEATING SHOULD OCCUR. KEPT NORTHEASTERN MD OUT OF THE
THUNDER MENTION FOR NOW WITH COOLER TEMPS EXPECTED. IN
ADDITION...THINKING THERE SHOULD BE TWO ROUNDS OF PCPN...THE INITIAL
SUN NIGHT...WITH A BREAK AT SOME POINT MONDAY WITH THE NEXT ROUND
MOVING IN AHEAD OF THE APPROACHING COLD FRONT. THE COLD FRONT PUSHES
THROUGH MONDAY NIGHT...WITH PCPN CLEARING TO THE EAST BY EARLY TUES
MORNING.
SFC HIGH PRESSURE BUILDS IN FROM THE SOUTH IN THE WAKE OF THE FRONT
THRU WED...QUICKLY PROGRESSING OFFSHORE BY THURS...AND RESULTING IN
BRIEF PERIOD OF DRY WX. THE REGION REMAINS POSITIONED AT THE BASE OF
A BROAD UPPER LVL CLOSED LOW...WHICH WILL SEND THROUGH THE NEXT COLD
FRONT MIDWEEK...BRINGING THE NEXT CHC FOR PCPN. NEAR NORMAL TEMPS
EXPECTED THROUGH THE PERIOD ON WLY FLOW.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
ANY LEFTOVER MVFR CIGS WILL IMPROVE TO VFR OVER THE NEXT HOUR OR
SO. THEN VFR WITH DRY CONDITIONS EXPECTED THROUGH NOON. A SFC
TROUGH ACROSS THE OHIO VALLEY WILL MOVE FROM WEST TO EAST ACROSS
THE TERMINALS THIS AFTERNOON. SHOWERS WILL REDEVELOP. AN ISOLATED
TS IS POSSIBLE MAINLY CHO-DCA. IN TERMS OF WINDS...SW FLOW IN THE
MORNING WITH POTENTIAL FOR GUSTS TO AROUND 15 KT. GUSTS ARE
EXPECTED TO DIMINISH BY EARLY AFTERNOON. WINDS WILL SHIFT TO THE W
THIS AFTN AND EVENTUALLY TO THE NW BY LATE AFTERNOON.
VFR CONDITIONS EXPECTED TONIGHT AND SATURDAY.
VFR CONDITIONS SAT NIGHT-SUN. SUB-VFR CONDITIONS BCMG LIKELY BY
SUN NIGHT WITH WIDESPREAD RAIN. PERIODS OF HEAVIER RAIN COULD DROP
CONDITIONS TO SUB-IFR SUN NIGHT. LLWS CONCERNS PSBL MON MORNING
WITH SE WINDS 40-50 KTS AT 2KFT...SHIFTING TO THE SOUTH DURING THE
MORNING.
SUB-VFR CONDITIONS REMAIN PSBL DURING THE DAY MON AS A COLD FRONT
BRINGS ANOTHER ROUND OF PCPN. SLIGHT CHC OF THUNDER CURRENTLY FOR
THE TAF SITES...MAINLY MON AFTN/EVENING. WIND SHIFT EXPECTED MON
EVENING WITH FRONTAL PASSAGE.
VFR CONDITIONS MON NIGHT AS THE PCPN TAPERS OFF...LASTING THRU WED.
&&
.MARINE...
SHOWERS HAVE MOVED EAST OF THE WATERS. SOUTHERLY CHANNELING IS
EXPECTED THIS MORNING AS A PRESSURE GRADIENT TIGHTENS ACROSS THE
WATERS. A SCA IS IN EFFECT FOR THE LOWER TIDAL POTOMAC AND MD
CHESAPEAKE BAY FOR GUSTS 18-20KTS. A SFC TROUGH WILL CROSS THE
WATERS THIS AFTERNOON. SHOWERS ARE EXPECTED AND AN ISOLATED
THUNDERSTORM IS POSSIBLE MAINLY ACROSS THE SOUTHERN WATERS. S
WINDS BECOME W-NW THIS EVENING. HIGH PRESSURE BUILDS IN TONIGHT
AND SATURDAY.
GENERALLY SUB-SCA CONDITIONS SAT NIGHT-SUN. SCA CONDITIONS PSBL
BY SUN NIGHT WITH INCRSG ELY FLOW. SCA CONDITIONS LAST DURING THE
DAY MON AHEAD OF THE COLD FRONT...BCMG SUB-SCA MON EVENING. GUSTS
TO 20 KTS PSBL AGAIN TUES AFTN IN THE WAKE OF THE FRONT.
&&
.EQUIPMENT...
AUDIO DEGRADATION AT THE NOAA WEATHER RADIO CHARLOTTESVILLE
TRANSMITTER IS EXPECTED TO CONTINUE THROUGH THIS WEEKEND.
TECHNICIANS ARE SCHEDULED TO PERFORM MAINTENANCE AT THE
TRANSMITTER SITE MONDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ530>534-
537>543.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ530>534-
537>543.
&&
$$
SYNOPSIS...SEARS
NEAR TERM...HAS/KCS
SHORT TERM...HAS
LONG TERM...SEARS
AVIATION...SEARS/HAS/KCS
MARINE...SEARS/HAS/KCS
EQUIPMENT...KCS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
359 AM EDT FRI APR 17 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO MOVE OFF THE COAST THIS MORNING. A
SURFACE TROUGH WILL PASS THROUGH THE REGION TODAY AND HIGH
PRESSURE WILL RETURN FOR SATURDAY. THE HIGH WILL MOVE OFF THE
COAST SUNDAY AND A WARM FRONT WILL MOVE INTO THE AREA SUNDAY NIGHT
INTO MONDAY. A COLD FRONT WILL PASS THROUGH LATE MONDAY INTO
MONDAY NIGHT BEFORE HIGH PRESSURE RETURNS FOR THE MIDDLE PORTION
OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
HIGH PRESSURE WILL CONTINUE TO MOVE OFF THE EAST COAST THIS
MORNING. AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE MID- ATLANTIC
THIS MORNING.
WARM AIR ADVECTION COUPLED WITH AN UPPER LEVEL DISTURBANCE HAS
ALLOWED SHOWERS TO MOVE ACROSS THE I-95 CORRIDOR THIS MORNING.
LESS THAN A QUARTER INCH HAS BEEN REPORTED OVERNIGHT. AN UPPER
LEVEL TROUGH WILL SWING THROUGH THE MID- ATLANTIC THIS MORNING AND
MOISTURE AND LIFT WILL PUSH OFF THE EAST COAST GIVING WAY TO DRIER
CONDITIONS. SHOWERS WILL DIMINISH BY MID- MORNING BUT A SFC
TROUGH CURRENTLY ACROSS THE OHIO VALLEY WILL MOVE THROUGH THE
REGION TODAY AND INCREASE POTENTIAL FOR MORE SHOWERS. A PERIOD OF
DRY CONDITIONS ARE EXPECTED THIS MORNING BETWEEN THE EXITING
UPPER LEVEL DISTURBANCE AND INCOMING SFC TROUGH.
TEMPS SHOULD RISE INTO THE L-M 70S BY AFTERNOON. NW FLOW WILL DRAW
IN COLD DRY AIR ALOFT TODAY. THIS WILL CAUSE LAPSE RATES TO INCREASE
AND SHOWERS ARE EXPECTED TO FORM ALONG THE SFC TROUGH BY EARLY
AFTERNOON. LATEST HRRR GUIDANCE SHOWS A BKN LINE OF CONVECTIVE
SHOWERS TO MOVE E-SE THROUGH THE AFTERNOON. AS THE SHOWERS MOVE
PAST I-66...WARMER SFC TEMPS AND DECENT BOUNDARY LAYER MIXING WILL
ALLOW A FEW HUNDRED J/KG OF CAPE. A FEW THUNDERSTORMS ARE POSSIBLE
SOUTH OF I-66/MD RT50 LATE THIS AFTERNOON AND EARLY EVENING.
CLEARING IS EXPECTED BEHIND THE SFC TROUGH INTO THE EVENING.
HIGH PRESSURE WILL MOVE INTO THE REGION TONIGHT AND PERSIST
SATURDAY. FCST MIN TEMPS INT HE 50S EXPECTED TONIGHT. FULL SUNSHINE
WILL ALLOW TEMPS TO RISE INTO THE UPPER 70S TO NEAR 80 IN THE METROS
SATURDAY.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
REGION REMAINS ON THE SOUTHERN PERIPHERY OF HIGH PRESSURE
CENTERED JUST NORTH OF THE GREAT LAKES. RIDGING BUILDS IN
ALOFT...WITH THE RIDGE AXIS SHIFTING ACROSS THE MID ATLANTIC BY
SUN MORNING. OVERALL PATTERN WILL KEEP THE AREA DRY. CLOUDS WILL
BEGIN TO INCREASE FROM THE SOUTHWEST AHEAD OF THE NEXT FRONTAL
SYSTEM. WINDS WILL LIGHTEN AND BECOME NE OVERNIGHT AS THE HIGH
BUILDS SOUTH.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
00Z MODEL SUITE CONTINUING WITH A SLOWER PROGRESSION OF THE NEXT
FRONTAL SYSTEM...AND THE ARRIVAL TIMING OF THE PCPN. RIDGE AXIS
SHIFTS EAST DURING THE DAY SUNDAY AS A DEEPENING CLOSED LOW OVER
THE NORTHERN PLAINS BUILDS EAST. BROAD LOW PRESSURE AT THE SFC
OVER THE CENTRAL PLAINS BECOMES ORGANIZED DURING HE DAY AS WELL AS
IT MOVES INTO THE WESTERN GREAT LAKES...GRADUALLY LIFTING THE
ASSOCIATED WARM FRONT TO THE NORTH AND INTO THE MID ATLANTIC.
GENERAL CONSENSUS AMONGST THE MODELS KEEPS THE WARM FRONT AT OR
JUST SOUTH OF THE VA/NC BORDER THRU SUN NIGHT...WITH PCPN
OCCURRING SUN-SUN NIGHT AS A RESULT OF DYNAMIC FORCING ALOFT WITH
MULTIPLE MID LVL SHORTWAVES AND STRENGTHENING LLJ AND 250MB JET.
PWATS INCRSG TO BETWEEN 1.2-1.4 IN...WHICH COULD RESULT IN PERIODS
OF MODERATE TO HEAVY RAIN.
SOME UNCERTAINTY STILL EXISTS WITH PCPN TIMING AND TSTM DEVELOPMENT
ON MONDAY. WARM FRONT LOOKS TO BE NEAR THE VA/NC BORDER EARLY
MONDAY...THEN GRADUALLY LIFTING NORTH DURING THE DAY. HOW QUICKLY IT
CAN CLEAR THE CWA AND WARM SECTOR THE AREA WILL AFFECT THE EXTENT OF
TSTM DEVELOPMENT...AND AS SUCH WILL CONTINUE TO MENTION SLIGHT CHC T
FOR MOST OF THE AREA NOW...AND CHC OVER CENTRAL VA WHERE THE BEST
DAYTIME HEATING SHOULD OCCUR. KEPT NORTHEASTERN MD OUT OF THE
THUNDER MENTION FOR NOW WITH COOLER TEMPS EXPECTED. IN
ADDITION...THINKING THERE SHOULD BE TWO ROUNDS OF PCPN...THE INITIAL
SUN NIGHT...WITH A BREAK AT SOME POINT MONDAY WITH THE NEXT ROUND
MOVING IN AHEAD OF THE APPROACHING COLD FRONT. THE COLD FRONT PUSHES
THROUGH MONDAY NIGHT...WITH PCPN CLEARING TO THE EAST BY EARLY TUES
MORNING.
SFC HIGH PRESSURE BUILDS IN FROM THE SOUTH IN THE WAKE OF THE FRONT
THRU WED...QUICKLY PROGRESSING OFFSHORE BY THURS...AND RESULTING IN
BRIEF PERIOD OF DRY WX. THE REGION REMAINS POSITIONED AT THE BASE OF
A BROAD UPPER LVL CLOSED LOW...WHICH WILL SEND THROUGH THE NEXT COLD
FRONT MIDWEEK...BRINGING THE NEXT CHC FOR PCPN. NEAR NORMAL TEMPS
EXPECTED THROUGH THE PERIOD ON WLY FLOW.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
MVFR CONDITIONS POSSIBLE THIS MORNING AS CIGS LOWER BEHIND
EXITING SHOWERS. CIGS SHOULD BECOME VFR SHORTLY AFTER SUNRISE AND
A PERIOD OF DRY CONDTIONS EXPECTED THROUGH NOON. A SFC TROUGH
ACROSS THE OHIO VALLEY WILL MOVE FROM WEST TO EAST ACROSS THE
TERMINALS THIS AFTERNOON. SHOWERS WILL REDEVELOP. AN ISOLATED TS
IS POSSIBLE MAINLY CHO-DCA. A WIND SHIFT FROM S-SW TO W-NW
EXPECTED TODAY. VFR CONDITIONS EXPECTED TONIGHT AND SATURDAY.
VFR CONDITIONS SAT NIGHT-SUN. SUB-VFR CONDITIONS BCMG LIKELY BY
SUN NIGHT WITH WIDESPREAD RAIN. PERIODS OF HEAVIER RAIN COULD DROP
CONDITIONS TO SUB-IFR SUN NIGHT. LLWS CONCERNS PSBL MON MORNING
WITH SE WINDS 40-50 KTS AT 2KFT...SHIFTING TO THE SOUTH DURING THE
MORNING.
SUB-VFR CONDITIONS REMAIN PSBL DURING THE DAY MON AS A COLD FRONT
BRINGS ANOTHER ROUND OF PCPN. SLIGHT CHC OF THUNDER CURRENTLY FOR
THE TAF SITES...MAINLY MON AFTN/EVENING. WIND SHIFT EXPECTED MON
EVENING WITH FRONTAL PASSAGE.
VFR CONDITIONS MON NIGHT AS THE PCPN TAPERS OFF...LASTING THRU WED.
&&
.MARINE...
SHOWERS WILL MOVE EAST OF THE WATERS BY MID-MORNING. SOUTHERLY
CHANNELING IS EXPECTED THIS MORNING AS A PRESSURE GRADIENT
TIGHTENS ACROSS THE WATERS. A SCA IS IN EFFECT FOR THE LOWER TIDAL
POTOMAC AND MD CHESAPEAKE BAY FOR GUSTS 18-20KTS. A SFC TROUGH
WILL CROSS THE WATERS THIS AFTERNOON. SHOWERS ARE EXPECTED AND AN
ISOLATED THUNDERSTORM IS POSSIBLE MAINLY ACROSS THE SOUTHERN
WATERS. S WINDS BECOME W-NW THIS EVENING. HIGH PRESSURE BUILDS IN
TONIGHT AND SATURDAY.
GENERALLY SUB-SCA CONDITIONS SAT NIGHT-SUN. SCA CONDITIONS PSBL
BY SUN NIGHT WITH INCRSG ELY FLOW. SCA CONDITIONS LAST DURING THE
DAY MON AHEAD OF THE COLD FRONT...BCMG SUB-SCA MON EVENING. GUSTS
TO 20 KTS PSBL AGAIN TUES AFTN IN THE WAKE OF THE FRONT. &&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ530>534-
537>543.
&&
$$
SYNOPSIS...SEARS/HAS
NEAR TERM...HAS
SHORT TERM...HAS
LONG TERM...SEARS
AVIATION...SEARS/HAS
MARINE...SEARS/HAS
AREA FORECAST DISCUSSION...UPDATED
NWS SPRINGFIELD MO
703 PM CDT Sat Apr 18 2015
...Update to Aviation Section...
.UPDATE...
Issued at 703 PM CDT SAT APR 18 2015
Forecast will be updated shortly to account for short term trends
from satellite/radar as well as to account for expected convective
trends heading into the overnight hours.
Over the past few hours, we have seen clearing across western
portions of the area. This clearing will likely be short lived as
mid/high level clouds increase from the west from convective
exhaust. That said, this area did see a soaking rain this morning
and dewpoints remain relatively high compared to expected lows. As
a result, will include a mention of patchy fog and keep an eye on
localized dense fog potential in places where skies can remain
clear for a longer period of time.
In addition, PoPs have been updated for the next 12 or so hours.
The western half of the area will likely see little in the way of
rain chances this evening. Chances over the eastern half look to
remain in the solid chance range giving on again/off again showers
and isolated thunder. HRRR and other short range models continue
to indicate rain chances increasing across south central Missouri
and the eastern Ozarks from late this evening into the overnight
hours. In addition, remnant convection from KS/OK complexes will
enter from the west, with rain chances steadily increasing
across extreme southeastern Kansas and western Missouri.
Interestingly, the Highway 65 corridor will likely be between
these two areas of activity and PoPs are lowest in this area for
tonight.
Taking a peak at tomorrow`s severe weather potential. There
remains some question as to just how much instability we will be
able to generate as decaying convection continues to spread in
from the west during the morning hours. The main upper trough will
not arrive until later in the day, bringing and increase in deep
layer shear. However, models struggle to bring much more that
500-1000 J/kg of most unstable CAPE into the southern half of the
area. By far the better chances for severe convection will be to
our south and southeast. Obviously this is close enough to keep a
close eye on trends and we will see what the 00z suite of models
have in store for the area.
&&
.SHORT TERM...(This Evening through Sunday Night)
Issued at 315 PM CDT SAT APR 18 2015
The coverage of showers and thunderstorms continued to decrease into
the afternoon. However a band of scattered showers and storms persisted
along a 925-850 MB convergence axis that stretched north to south
east of the Highway 65 corridor and in advance of a mid level vorticity
lobe lifting northeast across the area. Expect convection through
early evening to be focused along and ahead of these features
across south central Missouri. This 925-850 MB convergence axis
may become the focus for additional development later tonight
across the eastern Ozarks as another vorticity lobe lifts
northeast toward southeastern Missouri. Coverage of precipitation
will remain more isolated elsewhere much of tonight. However there
may be increase in convection from the west into southeastern
Kansas into far southwest late tonight as convection across the
Plains shifts eastward.
The closed upper level low now over eastern Colorado will open up
and track eastward toward Missouri on Sunday. Expect the coverage
of convection to increase Sunday as synoptic scale lift increases
with the aide of an increasingly diffluent upper flow and the
approach of vorticity maxima.
Deep layer shear will increase Sunday as the mid level flow
strengthens and lapse rates steepen as temperatures aloft cool in
response to the approaching upper level trough.
The question is the extent of instability that will develop. The
potential for ongoing convection and cloud cover may limit surface
heating and resulting instability. However if sufficient
instability can be realized then ingredients would be in place for
at least a few severe storms.
At this time the greatest potential for strong to severe storms
will be across far southern Missouri or generally along and south
of Interstate 44. The risk for severe weather could decrease or
increase depending on the amount of destabilization. The primary
risks with any severe storms that can develop would damaging winds
and large hail.
With some areas already receiving moderate to heavy rainfall the
past couple of days...the risk for localized flooding will have to
be monitored particularly across far southwestern Missouri.
Showers and some thunder will linger into Sunday night as the
upper level trough and associated cold front track across the
area.
.LONG TERM...(Monday through Saturday)
Issued at 315 PM CDT SAT APR 18 2015
Much cooler weather will prevail heading into early next week as
an upper level trough digs into the Great Lakes and maintains a
northwesterly flow aloft across the region. This cooler weather
will persist most of next week. Weather conditions could also be
rather unsettled as disturbances slide southeastward around the
periphery of the upper trough. This will bring intervals clouds and
the possibility of showers and thunderstorms at times mid through
late week. However this activity is expected to be spotty in
nature.
Temperatures could fall into the upper 30s Monday night. Frost is
not expected at this time but this potential should be monitored.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday Evening)
Issued at 703 PM CDT SAT APR 18 2015
Partial clearing, light winds and most grounds from earlier today
will bring a risk of fog to the area late this evening into the
overnight hours. At this time, have inserted MVFR fog at all
sites, however there is a chance for IFR (possibly lower)
conditions at BBG and SGF if skies can remain clear long enough
into the overnight hours. Better rain chances this evening will be
well to the west and just to the east of the aerodromes. Rain
chances will increase overnight at JLN as a decaying complex of
showers/storms approaches from KS/OK. This activity will spread
eastward into the SGF/BBG aerodromes during the daylight hours of
Sunday morning, with redevelopment of showers/storms possible at
all sites Sunday afternoon before exiting Sunday evening.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
UPDATE...Gagan
SHORT TERM...Foster
LONG TERM...Foster
AVIATION...Gagan
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1222 PM CDT Fri Apr 17 2015
.DISCUSSION...
Issued at 435 AM CDT FRI APR 17 2015
Today - Tonight:
Today will be a transition day. An upper ridge, now overhead, has
kept the KS/OK/TX Panhandle convection at bay since yesterday.
However, as the upper ridge nudges east this convection will be able
to edge closer and closer. This activity has been generated by weak
impulses ejecting from a cut-off upper low near the 4-corners area
and mid-level frontogenesis. This upper low has moved little over
the past 24 hours as it awaits its kicker which is just now crossing
into British Columbia. This latter feature is expected to strengthen
later today as upstream ridging sharpens and forces this shortwave
trough to dig southeast into the Northern Rockies...but not until
tomorrow. What this means is any convection reaching the CWA today
will weaken/fall apart as it moves away from the better upper
support.
Having said that there are some signals from the last couple runs of
the HRRR and to a lesser extent the 00z NAM that convection now
moving east through northern OK/south central KS could reach the far
western counties by around the noon hour. Regional radars show an
outflow boundary now expanding east from the KS convection with new
activity sprouting over north central OK. This activity is what the
HRRR picks up on and lifts northeast later this morning. So, will
slowly shift chance PoPs across the far western CWA today while
leaving the eastern half dry. Convective debris clouds will also
thin as they spread east today providing a thin veil of high clouds.
This shouldn`t hold back warming and expect temperatures to top out
in the middle and upper 70s.
The Southern Plateau closed low will gradually shift east tonight,
allowing new convection to push further east and become more
organized as it reaches the KS/MO state line towards sunrise. Will
handle this with a steady and gradual increase in PoPs through the
night.
Saturday - Sunday:
A very wet period with convection becoming numerous and likely
coming in waves as cells track nne while shifting slowly east. Model
precipitable water values 2 to 3 standard deviations are a cause for
concern. Steering winds in the 20kt area plus this moisture heighten
the threat of localized flooding. Have increased qpf and this may
even be underdone as its certainly feasible that some areas could
see up to 2 inches of rain through Saturday night. Extensive cloud
cover and rain-cooled air forces me to lower highs on both days and
won`t be surprised if they are lowered further in future
forecasts.
Modest MLCAPEs and 0-6km shear in the 20-30kt range are not likely
to support any severe threat on Saturday. Sunday may be a slightly
different story. By then the closed upper low will have opened up
and accelerated eastward. There is a chance we could be rain free
Sunday morning with some partial sunshine. Should this occur more
robust afternoon convection could form within a marginally supportive
airmass featuring MLCAPEs of 1200-1400 J/kg but only 25-30kt 0-6 km
bulk shear.
Monday - Friday:
The shortwave trough which will act as the kicker to move the
current closed upper low near the 4-corners will have formed into a
well developed upper trough from the Upper MS Valley through the Mid
MO Valley early in this period. As the upper trough axis passes
through on Monday strong subsidence and cold air advection will
provide ample sunshine but below average temperatures through
Tuesday.
By mid week, an upper ridge axis will build east into the Central
Plains with warm air advection spreading east. The GFS is more
aggressive and faster than the ECMWF in pushing weak mid level
vorticity lobes through the ridge axis. These features will be
ejected from a broad upper trough that will works into the desert
southwest. Difficult to determine how soon any scattered convection
could work its way back into the region. For now will introduce some
low chance PoPs for late Wednesday into Thursday.
The current closed upper low now over northern Mexico is expected to
weaken as it lifts north-northeast through the Central Plains and
CWA. While there should be decent moisture lifted northward with
this feature minimal instability will limit amount of thunder. Given
that the operational models have been generating a similar solution
believe 30-40 PoPs are warranted for scattered convection.
Thursday - Sunday:
Roll of the dice as to how weather will evolve from Thursday through
Sunday. Not especially fond of the blended model approach of carpet
bombing chance PoPs in every period. The medium range models drop a
deep upper trough into the Desert Southwest and then cut it off.
Models typically are challenged significantly with these features
initially. They tend to lift them out too soon and too far east. Will
be interesting to see how this system is handled going forward.
Difficult trying to time any weak impulse ejected from this system
within the downstream southwesterly flow. For now will handle this
with low chance PoPs with above average temperatures.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 1217 PM CDT FRI APR 17 2015
Band of showers will continue moving northeast, gradually weakening
while isolated convection will develop ahead of the activity.
Lightning has been on the decrease as the band has weakened, and
with the anticipated more scattered nature with time, expect
VCSH instead of prevailing period of precipitation. Rain should clear
terminal by mid-afternoon, with a lull in activity through midnight.
Next round of showers and embedded thunderstorms expected overnight,
with one or more rounds of convection through the end of the TAF
period. Will likely see periods of reduced visibility with overnight
activity, but prediction of specific reduction time is low and
precludes mention at this time.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...Blair
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
643 AM CDT Fri Apr 17 2015
.DISCUSSION...
Issued at 435 AM CDT FRI APR 17 2015
Today - Tonight:
Today will be a transition day. An upper ridge, now overhead, has
kept the KS/OK/TX Panhandle convection at bay since yesterday.
However, as the upper ridge nudges east this convection will be able
to edge closer and closer. This activity has been generated by weak
impulses ejecting from a cut-off upper low near the 4-corners area
and mid-level frontogenesis. This upper low has moved little over
the past 24 hours as it awaits its kicker which is just now crossing
into British Columbia. This latter feature is expected to strengthen
later today as upstream ridging sharpens and forces this shortwave
trough to dig southeast into the Northern Rockies...but not until
tomorrow. What this means is any convection reaching the CWA today
will weaken/fall apart as it moves away from the better upper
support.
Having said that there are some signals from the last couple runs of
the HRRR and to a lesser extent the 00z NAM that convection now
moving east through northern OK/south central KS could reach the far
western counties by around the noon hour. Regional radars show an
outflow boundary now expanding east from the KS convection with new
activity sprouting over north central OK. This activity is what the
HRRR picks up on and lifts northeast later this morning. So, will
slowly shift chance PoPs across the far western CWA today while
leaving the eastern half dry. Convective debris clouds will also
thin as they spread east today providing a thin veil of high clouds.
This shouldn`t hold back warming and expect temperatures to top out
in the middle and upper 70s.
The Southern Plateau closed low will gradually shift east tonight,
allowing new convection to push further east and become more
organized as it reaches the KS/MO state line towards sunrise. Will
handle this with a steady and gradual increase in PoPs through the
night.
Saturday - Sunday:
A very wet period with convection becoming numerous and likely
coming in waves as cells track nne while shifting slowly east. Model
precipitable water values 2 to 3 standard deviations are a cause for
concern. Steering winds in the 20kt area plus this moisture heighten
the threat of localized flooding. Have increased qpf and this may
even be underdone as its certainly feasible that some areas could
see up to 2 inches of rain through Saturday night. Extensive cloud
cover and rain-cooled air forces me to lower highs on both days and
won`t be surprised if they are lowered further in future
forecasts.
Modest MLCAPEs and 0-6km shear in the 20-30kt range are not likely
to support any severe threat on Saturday. Sunday may be a slightly
different story. By then the closed upper low will have opened up
and accelerated eastward. There is a chance we could be rain free
Sunday morning with some partial sunshine. Should this occur more
robust afternoon convection could form within a marginally supportive
airmass featuring MLCAPEs of 1200-1400 J/kg but only 25-30kt 0-6 km
bulk shear.
Monday - Friday:
The shortwave trough which will act as the kicker to move the
current closed upper low near the 4-corners will have formed into a
well developed upper trough from the Upper MS Valley through the Mid
MO Valley early in this period. As the upper trough axis passes
through on Monday strong subsidence and cold air advection will
provide ample sunshine but below average temperatures through
Tuesday.
By mid week, an upper ridge axis will build east into the Central
Plains with warm air advection spreading east. The GFS is more
aggressive and faster than the ECMWF in pushing weak mid level
vorticity lobes through the ridge axis. These features will be
ejected from a broad upper trough that will works into the desert
southwest. Difficult to determine how soon any scattered convection
could work its way back into the region. For now will introduce some
low chance PoPs for late Wednesday into Thursday.
The current closed upper low now over northern Mexico is expected to
weaken as it lifts north-northeast through the Central Plains and
CWA. While there should be decent moisture lifted northward with
this feature minimal instability will limit amount of thunder. Given
that the operational models have been generating a similar solution
believe 30-40 PoPs are warranted for scattered convection.
Thursday - Sunday:
Roll of the dice as to how weather will evolve from Thursday through
Sunday. Not especially fond of the blended model approach of carpet
bombing chance PoPs in every period. The medium range models drop a
deep upper trough into the Desert Southwest and then cut it off.
Models typically are challenged significantly with these features
initially. They tend to lift them out too soon and too far east. Will
be interesting to see how this system is handled going forward.
Difficult trying to time any weak impulse ejected from this system
within the downstream southwesterly flow. For now will handle this
with low chance PoPs with above average temperatures.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 639 AM CDT FRI APR 17 2015
Generally VFR conditions through this evening with a steady stream of
higher based clouds. Watching a band of showers and storms over north
central OK and south central KS that are starting to turn to the
northeast. Seeing signs this activity could lift through far eastern
KS and western MO but weaken during the afternoon hours. Rest of
northern and central MO should stay dry through the afternoon hours.
If current trends continue will likely need to amend forecast and
increase chances for thunder.
Should see a lull in activity this evening but another round of more
robust convection should form over KS tonight and reach far eastern
KS and western MO during the pre- dawn hours of Saturday morning.
Should see MVFR visibilities with this batch of showers and storms.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
436 AM CDT Fri Apr 17 2015
.DISCUSSION...
Issued at 435 AM CDT FRI APR 17 2015
Today - Tonight:
Today will be a transition day. An upper ridge, now overhead, has
kept the KS/OK/TX Panhandle convection at bay since yesterday.
However, as the upper ridge nudges east this convection will be able
to edge closer and closer. This activity has been generated by weak
impulses ejecting from a cut-off upper low near the 4-corners area
and mid-level frontogenesis. This upper low has moved little over
the past 24 hours as it awaits its kicker which is just now crossing
into British Columbia. This latter feature is expected to strengthen
later today as upstream ridging sharpens and forces this shortwave
trough to dig southeast into the Northern Rockies...but not until
tomorrow. What this means is any convection reaching the CWA today
will weaken/fall apart as it moves away from the better upper
support.
Having said that there are some signals from the last couple runs of
the HRRR and to a lesser extent the 00z NAM that convection now
moving east through northern OK/south central KS could reach the far
western counties by around the noon hour. Regional radars show an
outflow boundary now expanding east from the KS convection with new
activity sprouting over north central OK. This activity is what the
HRRR picks up on and lifts northeast later this morning. So, will
slowly shift chance PoPs across the far western CWA today while
leaving the eastern half dry. Convective debris clouds will also
thin as they spread east today providing a thin veil of high clouds.
This shouldn`t hold back warming and expect temperatures to top out
in the middle and upper 70s.
The Southern Plateau closed low will gradually shift east tonight,
allowing new convection to push further east and become more
organized as it reaches the KS/MO state line towards sunrise. Will
handle this with a steady and gradual increase in PoPs through the
night.
Saturday - Sunday:
A very wet period with convection becoming numerous and likely
coming in waves as cells track nne while shifting slowly east. Model
precipitable water values 2 to 3 standard deviations are a cause for
concern. Steering winds in the 20kt area plus this moisture heighten
the threat of localized flooding. Have increased qpf and this may
even be underdone as its certainly feasible that some areas could
see up to 2 inches of rain through Saturday night. Extensive cloud
cover and rain-cooled air forces me to lower highs on both days and
won`t be surprised if they are lowered further in future
forecasts.
Modest MLCAPEs and 0-6km shear in the 20-30kt range are not likely
to support any severe threat on Saturday. Sunday may be a slightly
different story. By then the closed upper low will have opened up
and accelerated eastward. There is a chance we could be rain free
Sunday morning with some partial sunshine. Should this occur more
robust afternoon convection could form within a marginally supportive
airmass featuring MLCAPEs of 1200-1400 J/kg but only 25-30kt 0-6 km
bulk shear.
Monday - Friday:
The shortwave trough which will act as the kicker to move the
current closed upper low near the 4-corners will have formed into a
well developed upper trough from the Upper MS Valley through the Mid
MO Valley early in this period. As the upper trough axis passes
through on Monday strong subsidence and cold air advection will
provide ample sunshine but below average temperatures through
Tuesday.
By mid week, an upper ridge axis will build east into the Central
Plains with warm air advection spreading east. The GFS is more
aggressive and faster than the ECMWF in pushing weak mid level
vorticity lobes through the ridge axis. These features will be
ejected from a broad upper trough that will works into the desert
southwest. Difficult to determine how soon any scattered convection
could work its way back into the region. For now will introduce some
low chance PoPs for late Wednesday into Thursday.
The current closed upper low now over northern Mexico is expected to
weaken as it lifts north-northeast through the Central Plains and
CWA. While there should be decent moisture lifted northward with
this feature minimal instability will limit amount of thunder. Given
that the operational models have been generating a similar solution
believe 30-40 PoPs are warranted for scattered convection.
Thursday - Sunday:
Roll of the dice as to how weather will evolve from Thursday through
Sunday. Not especially fond of the blended model approach of carpet
bombing chance PoPs in every period. The medium range models drop a
deep upper trough into the Desert Southwest and then cut it off.
Models typically are challenged significantly with these features
initially. They tend to lift them out too soon and too far east. Will
be interesting to see how this system is handled going forward.
Difficult trying to time any weak impulse ejected from this system
within the downstream southwesterly flow. For now will handle this
with low chance PoPs with above average temperatures.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1147 PM CDT THU APR 16 2015
VFR conditions to dominate through much of the fcst period...with
winds remaining from the east and southeast between 5-10 kts. Clouds
will be on the increase after 15z as long awaited storm system now
across the Four Corners region slowly tracks east. Cannot rule out
some isolated thunderstorms during the late afternoon...however more
concentrated activity will likely hold off until after 00z.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...32
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
613 PM CDT SAT APR 18 2015
.SYNOPSIS...
ISSUED AT 255 PM CDT SAT APR 18 2015
ANALYSIS OF THE 19Z MSL DATA SHOWED LOW PRESSURE CENTERED IN WESTERN
KANSAS WITH A WARM FRONT ACROSS NORTHERN KANSAS...A COLD FRONT INTO
THE OKLAHOMA/TEXAS PANHANDLE AND AN INVERTED TROUGH FROM SOUTHWEST
TO NORTH CENTRAL NEBRASKA. IN THE UPPER LEVELS...THE WATER VAPOR
IMAGERY SHOWED A CLOSED CYCLONIC CIRCULATION LOCATED IN EASTERN
COLORADO.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 255 PM CDT SAT APR 18 2015
THE CENTER OF STRONG CUT OFF LOW /H500 MB TEMP -25C/ IS NEAR AKRON
COLORADO THIS AFTERNOON. HIGH RES MODELS INSIST THAT
CONVECTION...AIDED BY A SIGNIFICANT PV ANOMALY ROTATING NORTHEAST
INTO WESTERN KANSAS AROUND THE LOW CENTER...WILL DEVELOP ONCE AGAIN
ACROSS NORTHWEST KANSAS AND SOUTHWEST NEBRASKA LATE THIS AFTERNOON
AND THIS EVENING. THE ACTIVITY WILL GROW UPSCALE MUCH LIKE LAST
NIGHT AS IT MOVES NORTH/NORTHEAST INTO THE REST OF WESTERN...CENTRAL
AND NORTH CENTRAL NEBRASKA TONIGHT.
AS FAR AS SEVERE POTENTIAL...GOOD SURFACE HEATING UNDERWAY ATTM
ACROSS SOUTHWEST NEBRASKA AND NORTHWEST KANSAS. EXPECTING MUCAPE ON
THE ORDER OF 1500 J/KG BY LATE AFTERNOON INTO THE EVENING HOURS. ONE
WEAKNESS ARE THE WIND FIELDS ARE FAIRLY LIGHT...AND NOT A A LOT OF
VEERING WITH HEIGHT. NEVERTHELESS WITH THE STEEP LOW AND MID LEVEL
LAPSE RATES...WILL SEE SOME VIGOROUS UPDRAFTS...AND SOME HAIL LIKELY
WITH THOSE STRONGER UPDRAFTS. TORNADO POTENTIAL IS NOT ZERO...BUT
AGAIN WITH THE WEAK WIND FIELDS AND LIMITED VEERING...NOT EXPECTING
THAT TO BE THE PRIMARY RISK. IF A TORNADO OCCURS IT WOULD MORE THAN
LIKELY BE WEAK. K INDICES ARE HIGH...AND LOCALLY HEAVY RAINFALL
WILL BE POSSIBLE.
THE CLOSED H500 MB CIRCULATION IS FORECASTED TO MIGRATE INTO
NORTHWEST KANSAS BY SUNDAY MORNING...AND CONTINUE EAST ACROSS KANSAS
DURING THE DAY. A SMALL DEFORMATION BAND OF PRECIPITATION IS LIKELY
ON THE NORTH AND WEST SIDE OF THE TRACK. THE EXACT TRACK OF THE LOW
CENTER IS UNCERTAIN...AS CONVECTION LIKELY TO INFLUENCE THE MASS
FIELD AND EXPECT THE FINAL TRACK COULD END UP A LITTLE FARTHER
NORTH. THIS IS HINTED IN THE LATEST RUN OF THE RAP MODEL. OTHERWISE
A COLD FRONT ASSOCIATED WITH A SEPARATE NORTHERN STREAM SYSTEM WILL
CRASH THROUGH THE AREA...BRINGING GUSTY NORTHWEST WINDS TO THE
REGION.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 255 PM CDT SAT APR 18 2015
MEDIUM RANGE...(SUNDAY NIGHT THROUGH TUESDAY)
THE UPPER LEVEL LOW ACROSS COLORADO WILL LIFT OUT AND COLLIDE WITH
AN UPPER LEVEL SHORT WAVE ACROSS ACROSS THE NORTHERN GREAT LAKES
FORMING A VERY LARGE CLOSED UPPER LOW. UPSTREAM HEIGHTS RISE SHARPLY
ACROSS NRN CANADA SUPPORTING A BROAD AREA OF HIGH PRESSURE WHICH
CIRCULATE COOL AIR SOUTH THROUGH THE PLAINS AND MIDWEST. THIS KEEPS
THE FORECAST AREA IN COOL NORTHWEST FLOW. DAYTIME MIXING PRODUCES
PARTLY CLOUDY SKIES MONDAY AND TUESDAY PLACING A LIMIT ON HEATING.
MONDAY WOULD BE A WINDY DAY WITH NORTHWEST WINDS INCREASING TO 20
TO 30 MPH IN THE AFTN WHICH WEAKEN AT SUNSET. WINDS STAY REASONABLY
STRONG SUNDAY NIGHT ALSO. THE EFFECT ON TEMPERATURES WOULD BE FOR
LOWS MONDAY MORNING FALLING INTO THE UPPER 20S ACROSS WESTERN
NEBRASKA BUT ABOVE FREEZING EAST OF HIGHWAY 83. LOWS FALL BELOW
FREEZING EVERYWHERE MONDAY NIGHT EXCEPT ALONG HIGHWAY 281. HIGHS
RISE INTO THE 50S MONDAY AND LOWER 60S TUESDAY.
THE FORECAST IS DRY AND THE MODELS INDICATE DEW POINTS FALL INTO
TEENS AND 20S SUNDAY NIGHT THROUGH TUESDAY. THE RISK TO THE FORECAST
IS THAT THE VERY DRY AIR COULD SUPPORT COLDER LOWS THAN FORECAST BUT
THAT WOULD COMPETE DIRECTLY WITH THE WARM WET GROUND FROM THE HEAVY
RAINFALL.
EXTENDED RANGE...(TUESDAY NIGHT THROUGH SATURDAY)
A RIDGE IN WESTERN NORTH AMERICA CONTINUES TO BUILD INTO THE
NORTHWEST TERRITORIES AND NORTHERN ALBERTA OPENING UP A PATH FROM
NUNAVUT IN EXTREME NORTHERN CANADA TO NORTH CENTRAL AND NORTHEAST
NEBRASKA. AS A RESULT...TEMPERATURES ARE EXPECTED TO BE A LITTLE
BELOW THE SEASONAL AVERAGES IN THE NORTHEAST NEBRASKA SANDHILLS AND
THE NIOBRARA VALLEY WITH NIGHTTIME TEMPERATURES AT OR BELOW FREEZING
INTO FRIDAY MORNING. EVEN IN THE WESTERN SANDHILLS...THE EASTERN
PANHANDLE AND SOUTHWEST NEBRASKA WILL BE SLIGHTLY BELOW AVERAGE
WITH LOWS IN THE LOW TO MID 30S.
IN THE SOUTHWEST STATES...A TROUGH DIGS INTO SOUTHERN CALIFORNIA
RESULTING IN SOUTHWEST FLOW ALOFT ACROSS THE CENTRAL PLAINS. A WEAK
INVERTED TROUGH MOVING ACROSS THE PLAINS COULD BRING THE POSSIBILITY
OF SHOWERS TO CENTRAL AND WESTERN NEBRASKA THURSDAY THROUGH
SATURDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 612 PM CDT SAT APR 18 2015
SCATTERED THUNDERSTORMS IN CENTRAL AND SOUTHWEST NEBRASKA ARE
EXPECTED TO INCREASE IN COVERAGE AND INTENSITY THIS EVENING UNTIL
02Z. DURING THAT TIME...HAIL AND VERY HEAVY RAIN CAN BE EXPECTED
WITH LARGE HAIL POSSIBLE. AFTER 02Z...THE PROBABILITY OF
THUNDERSTORMS WILL DECREASE. THEN...CEILING AND VISIBILITY WILL BE
ABOVE THE INSTRUMENT THRESHOLD THOUGH MARGINAL CONDITIONS ARE
POSSIBLE.
AFTER 08Z...WIND WILL SHIFT TO 340-360 AT 10-16KT AND THEN INCREASE
TO 14-18G24-30KT BY 14Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SPRINGER
SHORT TERM...TAYLOR
LONG TERM...CDC/SPRINGER
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1203 PM CDT FRI APR 17 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 318 AM CDT FRI APR 17 2015
PCPN CHANCES AND TEMPERATURES ARE THE PRIMARY FORECAST CONCERNS
IN THE TODAY PERIOD...THEN CONTINUED SHOWER/THUNDERSTORM CHANCES
ESPECIALLY FRIDAY NIGHT THROUGH SATURDAY NIGHT...THEN THE COLD
FRONTAL PASSAGE AND PRECIPITATION ENDING SUNDAY.
REGIONAL RADAR EARLY THIS MORNING SHOWS AREA OF SHOWERS AND ISOLATED
THUNDERSTORMS PIVOTING NORTH TO NORTHWEST FROM KANSAS INTO NEBRASKA
AROUND CLOSED UPPER LOW OVER SOUTH CENTRAL COLORADO. WESTERN
PORTIONS OF THE FORECAST AREA WILL BE MOST LIKELY TO SEE PRECIP
TODAY WITH EASTERN AREAS HAVING TO WAIT UNTIL THE AFTERNOON FOR
BETTER POPS AS THE UPPER LOW TRACKS SLOWLY EAST. RAP FORECAST
SOUNDINGS SHOW LIMITED INSTABILITY THROUGH MOST OF THE DAY
ESPECIALLY IN THE EAST AND NORTH WITH INCREASING INSTABILITY IN
WESTERN PARTS OF THE AREA ALONG AND WEST OF A BEATRICE-LINCOLN-
COLUMBUS ARC BY LATE AFTERNOON.
CLOUD COVER IS EXPECTED TO REMAIN IN PLACE MUCH OF THE DAY FOR THE
WEST HALF OF THE AREA WITH VARIABLE SKY COVER IN THE EAST HALF. THIS
SPLIT SHOULD SEE LOWER TEMPS AROUND 70 CONFINED TO THE WEST WITH MID
70S IN THE EAST WHERE SOME PERIODS OF SUN ARE POSSIBLE.
TONIGHT...THE OPERATIONAL MODELS ARE IN GOOD AGREEMENT THAT THE
CLOSED H5 LOW OVER THE FOUR-CORNERS REGION WILL LIFT NORTHEAST TO
COLORADO BY 00Z TONIGHT. THE H5 LOW MEANDERS OVER COLORADO THROUGH
SATURDAY...THEN DRIFTS INTO WESTERN KANSAS BY 06Z. THE NAM IS
SLIGHTLY DIFFERENT IN SPLITTING SOME OF THE H5 ENERGY TO THE NORTH
IN SOUTH DAKOTA AND THE CLOSED LOW A LITTLE FARTHER SOUTH TOWARD
OKLAHOMA.
SHOWERS AND THUNDERSTORMS SHOULD BE ONGOING OVER PARTS OF THE CWA
AND WILL CONTINUE TO SPREAD NORTH AND EAST FRIDAY NIGHT AND
SATURDAY. THESE PERIODS WILL HAVE THE HIGHEST POPS THIS WEEKEND.
THE INSTABILITY AXIS DOES LIFT NORTHWARD FRIDAY NIGHT AND
CONTINUES OVER THE AREA SATURDAY. THERE IS ALSO AN H85 BOUNDARY IN
THIS REGION THAT LIFTS NORTH AND MAY PROVIDE A FOCUS FOR ENHANCED
CONVECTIVE ACTIVITY. SOME .25-.5 INCH RAINS FELL ALONG WITH PEA
TO DIME- SIZED HAIL WAS REPORTED WITH SOME OF THE STORMS IN
SOUTHERN NEBRASKA THURSDAY NIGHT. FORECAST SOUNDINGS SHOW WEAK
INSTABILITY WITH MLCAPE OF 200J/KG FRIDAY NIGHT...AND A LITTLE
BETTER INSTABILITY WITH MLCAPE OF 500J/KG SATURDAY. SOME OF THE
STRONGER STORMS MAY PRODUCE SOME HAIL. RAINFALL AMOUNTS THROUGH
SATURDAY COULD RANGE FROM .5 TO 1 INCH.
SATURDAY NIGHT...THE MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO SHIFT FARTHER EAST INTO IOWA AND EXTEND IN A LARGE AREA
FROM THE GULF STATES THROUGH THE MISSISSIPPI VALLEY INTO MINNESOTA
AND THE DAKOTA. THE LOW LEVEL JET OF 40-50KTS DEVELOPS OVER IOWA
INTO MINNESOTA AND EVENTUALLY WI. THE H85 THERMAL RIDGE IS OVER THE
FORECAST AREA. BY 12Z SUNDAY THE GFS/NAM/EC ARE SIMILAR AND HAVE THE
SURFACE LOW OVER NORTHEAST NEBRASKA WITH A FRONT OVER FAR EASTERN
NEBRASKA INTO WESTERN IOWA. THIS BOUNDARY IS EAST OF THE AREA BY
18Z. WITH THE LONGWAVE TROF STILL MOVING THROUGH THE AREA...THERE
WILL STILL BE SCATTERED SHOWERS AND THUNDERSTORMS SATURDAY NIGHT AND
SUNDAY MORESO IN SOUTHEAST NEBRASKA. NORTHWEST WINDS BEHIND THE
FRONT TURN WINDY 15 TO 25KTS AT THE SURFACE WITH 40 TO 50KTS AT
H85. THE MOISTURE DRIES OUT TO .5-.75 PWAT BY 00Z AND 0.25 OF AN
INCH PWAT BY 12Z MONDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 318 AM CDT FRI APR 17 2015
THE CLOSED MID TROPOSPHERIC LOW OVER THE UPPER
MISSISSIPPI VALLEY MONDAY...SHIFTS TO THE UPPER GREAT LAKES
TUESDAY...AND LINGERS THERE THROUGH THURSDAY. IT SHOULD BE DRY
SUNDAY NIGHT THROUGH TUESDAY. HIGHS SHOULD BE IN THE 50S AND 60S. THE
GFS IS SLIGHTLY FARTHER NORTH WITH LOW...AND THIS ALLOWS A STORM
SYSTEM THAT MOVES INTO THE WESTERN U.S. TO AFFECT THE LOCAL AREA
WITH SHOWERS AND ISOLATED THUNDERSTORMS WEDNESDAY INTO THE REST OF
THE WEEK. THE EC IS MAINLY DRY THRU THURSDAY.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1158 AM CDT FRI APR 17 2015
VFR CONDITIONS ARE EXPECTED THROUGH TODAY...WITH CEILINGS AROUND
5-8KFT. LATE AFTERNOON TO EVENING...INCREASING COVERAGE OF SHOWERS
WILL BRING AT LEAST A VICINITY THREAT TO KOFK AND KLNK...WITH MORE
WIDESPREAD POTENTIAL AFTER 02Z. ANY SHOWERS AFFECTING TAF SITES
MAY BRING THUNDER...AS WELL AS VIS AND POSSIBLY EVEN CIGS INTO
MVFR RANGE. HAVE JUST MENTIONED THE SHOWERS AND VIS RESTRICTIONS
FOR NOW...WITH TIME YET TO MODIFY AS TIMING OF SHOWERS BECOMES
MORE EVIDENT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...FOBERT/ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...MAYES
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
332 AM CDT FRI APR 17 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 318 AM CDT FRI APR 17 2015
PCPN CHANCES AND TEMPERATURES ARE THE PRIMARY FORECAST CONCERNS
IN THE TODAY PERIOD...THEN CONTINUED SHOWER/THUNDERSTORM CHANCES
ESPECIALLY FRIDAY NIGHT THROUGH SATURDAY NIGHT...THEN THE COLD
FRONTAL PASSAGE AND PRECIPITATION ENDING SUNDAY.
REGIONAL RADAR EARLY THIS MORNING SHOWS AREA OF SHOWERS AND ISOLATED
THUNDERSTORMS PIVOTING NORTH TO NORTHWEST FROM KANSAS INTO NEBRASKA
AROUND CLOSED UPPER LOW OVER SOUTH CENTRAL COLORADO. WESTERN
PORTIONS OF THE FORECAST AREA WILL BE MOST LIKELY TO SEE PRECIP
TODAY WITH EASTERN AREAS HAVING TO WAIT UNTIL THE AFTERNOON FOR
BETTER POPS AS THE UPPER LOW TRACKS SLOWLY EAST. RAP FORECAST
SOUNDINGS SHOW LIMITED INSTABILITY THROUGH MOST OF THE DAY
ESPECIALLY IN THE EAST AND NORTH WITH INCREASING INSTABILITY IN
WESTERN PARTS OF THE AREA ALONG AND WEST OF A BEATRICE-LINCOLN-
COLUMBUS ARC BY LATE AFTERNOON.
CLOUD COVER IS EXPECTED TO REMAIN IN PLACE MUCH OF THE DAY FOR THE
WEST HALF OF THE AREA WITH VARIABLE SKY COVER IN THE EAST HALF. THIS
SPLIT SHOULD SEE LOWER TEMPS AROUND 70 CONFINED TO THE WEST WITH MID
70S IN THE EAST WHERE SOME PERIODS OF SUN ARE POSSIBLE.
TONIGHT...THE OPERATIONAL MODELS ARE IN GOOD AGREEMENT THAT THE
CLOSED H5 LOW OVER THE FOUR-CORNERS REGION WILL LIFT NORTHEAST TO
COLORADO BY 00Z TONIGHT. THE H5 LOW MEANDERS OVER COLORADO THROUGH
SATURDAY...THEN DRIFTS INTO WESTERN KANSAS BY 06Z. THE NAM IS
SLIGHTLY DIFFERENT IN SPLITTING SOME OF THE H5 ENERGY TO THE NORTH
IN SOUTH DAKOTA AND THE CLOSED LOW A LITTLE FARTHER SOUTH TOWARD
OKLAHOMA.
SHOWERS AND THUNDERSTORMS SHOULD BE ONGOING OVER PARTS OF THE CWA
AND WILL CONTINUE TO SPREAD NORTH AND EAST FRIDAY NIGHT AND
SATURDAY. THESE PERIODS WILL HAVE THE HIGHEST POPS THIS WEEKEND.
THE INSTABILITY AXIS DOES LIFT NORTHWARD FRIDAY NIGHT AND
CONTINUES OVER THE AREA SATURDAY. THERE IS ALSO AN H85 BOUNDARY IN
THIS REGION THAT LIFTS NORTH AND MAY PROVIDE A FOCUS FOR ENHANCED
CONVECTIVE ACTIVITY. SOME .25-.5 INCH RAINS FELL ALONG WITH PEA
TO DIME- SIZED HAIL WAS REPORTED WITH SOME OF THE STORMS IN
SOUTHERN NEBRASKA THURSDAY NIGHT. FORECAST SOUNDINGS SHOW WEAK
INSTABILITY WITH MLCAPE OF 200J/KG FRIDAY NIGHT...AND A LITTLE
BETTER INSTABILITY WITH MLCAPE OF 500J/KG SATURDAY. SOME OF THE
STRONGER STORMS MAY PRODUCE SOME HAIL. RAINFALL AMOUNTS THROUGH
SATURDAY COULD RANGE FROM .5 TO 1 INCH.
SATURDAY NIGHT...THE MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO SHIFT FARTHER EAST INTO IOWA AND EXTEND IN A LARGE AREA
FROM THE GULF STATES THROUGH THE MISSISSIPPI VALLEY INTO MINNESOTA
AND THE DAKOTA. THE LOW LEVEL JET OF 40-50KTS DEVELOPS OVER IOWA
INTO MINNESOTA AND EVENTUALLY WI. THE H85 THERMAL RIDGE IS OVER THE
FORECAST AREA. BY 12Z SUNDAY THE GFS/NAM/EC ARE SIMILAR AND HAVE THE
SURFACE LOW OVER NORTHEAST NEBRASKA WITH A FRONT OVER FAR EASTERN
NEBRASKA INTO WESTERN IOWA. THIS BOUNDARY IS EAST OF THE AREA BY
18Z. WITH THE LONGWAVE TROF STILL MOVING THROUGH THE AREA...THERE
WILL STILL BE SCATTERED SHOWERS AND THUNDERSTORMS SATURDAY NIGHT AND
SUNDAY MORESO IN SOUTHEAST NEBRASKA. NORTHWEST WINDS BEHIND THE
FRONT TURN WINDY 15 TO 25KTS AT THE SURFACE WITH 40 TO 50KTS AT
H85. THE MOISTURE DRIES OUT TO .5-.75 PWAT BY 00Z AND 0.25 OF AN
INCH PWAT BY 12Z MONDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 318 AM CDT FRI APR 17 2015
THE CLOSED MID TROPOSPHERIC LOW OVER THE UPPER
MISSISSIPPI VALLEY MONDAY...SHIFTS TO THE UPPER GREAT LAKES
TUESDAY...AND LINGERS THERE THROUGH THURSDAY. IT SHOULD BE DRY
SUNDAY NIGHT THROUGH TUESDAY. HIGHS SHOULD BE IN THE 50S AND 60S. THE
GFS IS SLIGHTLY FARTHER NORTH WITH LOW...AND THIS ALLOWS A STORM
SYSTEM THAT MOVES INTO THE WESTERN U.S. TO AFFECT THE LOCAL AREA
WITH SHOWERS AND ISOLATED THUNDERSTORMS WEDNESDAY INTO THE REST OF
THE WEEK. THE EC IS MAINLY DRY THRU THURSDAY.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1149 PM CDT THU APR 16 2015
SCT SHRA MAY AFFECT THE KLNK TAF OVER THE NEXT COUPLE OF HOURS BUT
THIS PRECIP WILL HAVE A HARD TIME MOVING NWD TOWARD THE KOMA TAF
DUE TO HIGHER STABILITY. SOME OF THIS -RA MAY MOVE INTO KOFK
TOWARD MRNG AND WILL INCLUDE A TEMPO GROUP THERE FOR A COUPLE
HOURS. MOST OF FRI SHOULD BE DRY FOR THE TAFS WITH A SCT-BKN MID
LEVEL CLOUD DECK AND LIGHT WINDS. SCT SHRA MAY AGAIN DVLP FRI EVNG
/ESPECIALLY FOR KOFK-KLNK THRU 06Z/ WITH AN EVEN BETTER CHANCE OF
PRECIP AT ALL THE TAF SITES JUST AFTER THIS PERIOD.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...FOBERT/ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
144 PM EDT FRI APR 17 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE ACROSS CENTRAL NEW YORK EARLY THIS
AFTERNOON AND NORTHEAST PENNSYLVANIA BY LATE AFTERNOON. THIS FRONT
WILL TRIGGER A FEW SHOWERS WITH AN ISOLATED THUNDERSTORM IN
NORTHEAST PENNSYLVANIA. ANOTHER COLD FRONT WILL PASS ACROSS THE
REGION SATURDAY. THIS FRONT COULD TRIGGER SOME SHOWERS IN
NORTHERN AND EASTERN NEW YORK WITH MAINLY DRY WEATHER IN CENTRAL
NEW YORK AND NORTHEAST PENNSYLVANIA. HIGH PRESSURE AND COOLER
WEATHER WILL BUILD ACROSS THE REGION FOR SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WATER VAPOR IMAGERY SHOWS A SHORT WAVE MOVING ACROSS THE EASTERN
GREAT LAKES AND EASTERN OHIO VALLEY THIS MORNING. THIS WAVE WILL
PUSH A WEAK FRONT ACROSS THE REGION THIS AFTERNOON WITH SOME LL
DRY ADVECTION BEHIND THE FRNT. THE FRONT AND LIFT ASSCTD WITH THE
SHRT WAVE WILL TRIGGER ISLD TO SCT SHRA ACRS C NY/NE PA THIS
AFTERNOON. THE FRNT COMES THRU AT MAX HEATING LATE THIS AFTERNOON
ESP IN NE PA. CAPES ON THE HI RES MODELS NOW ARE RANGING FROM
ARND 250 TO 500 J/KG IN NE PA ARND 21Z WITH THE HIGHER RESOLUTION
MODELS SHOWING SCT CONVECTIVE CELLS FORMING ON SIMULATED RADAR
FIELDS. THE BULK SHEAR IS ARND 20 KNOTS 0-1 KM AND 0-3 KM AND ABT
35 KNOTS 0-6 KM. FORCING IS NOT STRG BUT I HAVE ADDED ISLD TSRA TO
NE PA GRIDS. I MAY HAVE TO ADJUST THIS UP EVEN MORE AS RECENT RAP
AND HRRR RUNS HAVE MORE CAPE. WILL CONT TO MONITOR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
NW FLOW ALOFT TNGT WITH WEAK SFC FEATURES WILL RESULT IN A QUIET
PD WITH LGT WINDS AND BKN CLDS. WHILE A SHWR CAN/T BE RULED
OUT...NOT ENUF OF A CHANCE TO INCLUDE IN THE FCST ATTM.
SATURDAY WILL SEE A SHRT WV PASSING THRU NRN NEW ENG AND SOME LATE
DAY CAA IN THE WAKE OF THE WV. MODELS SHOW VERY DRY AIR OVER THE
AREA WITH THE BEST FRCG STAYING TO THE NE. SOME INSTABILITY LIKELY
WITH THE LWRD HGTS BUT DRY AIR SHD INHIBIT ANY SHWRS FROM FRMG IN
THE FCST AREA...ALTHOUGH NRN ONEIDA WILL BE CLOSE.
UPR RDGG OVER THE GREAT LAKES WILL ALLOW SFC HIPRES TO SLIDE INTO
THE AREA ON SUNDAY. TEMPS WILL BE A BIT LWR WITH THE CAA BUT DRIER
AIR SHD ALLOW FOR MSTLY SUNNY SKIES.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
0245 AM UPDATE...ONLY MADE A FEW ADJUSTMENTS TO PREVIOUS FORECAST
MADE DURING THE DAY SHIFT THURSDAY. MAIN CHANGE WAS TO ADJUST HIGH
TEMPS DOWN FOR MONDAY, WEDNESDAY, AND THURSDAY OF NEXT WEEK AS
GUIDANCE CONTINUES TO INDICATE WE WILL BE COOLER AND MORE
UNSETTLED UNDER THE INFLUENCE OF AN UPPER LEVEL TROUGH.
445 PM THURSDAY UPDATE... MODELS IN GOOD AGREEMENT ON MOIST
OCCLUDED FRONT LIKELY TO BRING RAIN AS IT SWEEPS THROUGH THE
REGION LATE SUNDAY NIGHT THROUGH MONDAY. SHOWALTER INDICES ONLY
GET TO AROUND ZERO...SHOWING ONLY SMALLEST HINT OF ELEVATED
INSTABILITY...SO CHANCE OF EMBEDDED THUNDER DURING THAT PERIOD
LOOKS MINIMAL TO NONE. QUARTER TO HALF INCH OF RAIN LOOKS QUITE
DOABLE HOWEVER.
CUTOFF LOW CURRENTLY OVER FOUR CORNERS REGION...IS DEPICTED BY
GFS-ECMWF TO MERGE WITH A DIGGING NORTHERN STREAM TROUGH OVER THE
MIDWEST THIS WEEKEND. THOSE FEATURES WILL COMBINE INTO A NEW
LARGER CUTOFF LOW...THE CENTER OF WHICH WILL SLOWLY SLOG ITS WAY
OVER THE WESTERN GREAT LAKES NEXT WEEK. THIS UPPER LOW WILL HAVE A
LARGE FOOTPRINT WITH DISTURBANCES-WAVES ROTATING AROUND IT ACROSS
GREAT LAKES TO NORTHEAST. MODELS DISAGREE ON LOCATION OF UPPER LOW
CENTER BY THURSDAY /EITHER CENTRAL GREAT LAKES AND HEADING EAST...OR
A BIT FURTHER NORTH AND STILL PARKED/ YET EITHER WAY IT LOOKS
RATHER TROUGHY AND UNSETTLED WITH CYCLONIC FLOW OVER OUR REGION.
SO AFTER BRIEFLY MILDER CONDITIONS TUESDAY...WE SHOULD TREND BACK
TO NEAR CLIMATOLOGY FOR TEMPERATURES WEDNESDAY-THURSDAY. IF THE
UPPER LOW SHIFTS EAST AS PER ECMWF...POSSIBLY A LITTLE COOLER THAN
CLIMATOLOGY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
SFC TROF IS MOVING THROUGH NRN PA AT 18Z WITH LOW LEVEL DRY AIR
ADVECTION BEHIND BOUNDARY. MVFR/LOW MVFR CIGS WILL IMPROVE TO VFR
BY LATE AFTERNOON WITH SKIES EXPECTED TO CLEAR EARLY THIS EVENING.
PATCHY FOG IS POSSIBLE OVERNIGHT DUE TO LIGHT WINDS AND WET GROUND
BUT MIST IS ONLY INCLUDED IN THE KRME TAF BETWEEN 09Z-13Z DUE TO
LIGHT EASTERLY FLOW. ON SATURDAY JUST SCT CLOUDS AROUND 4K FT.
W/NW WINDS AROUND 10 KNOTS BECOMING LIGHT AND VARIABLE THIS
EVENING THEN NW ON SATURDAY AT 10-15 KNOTS WITH GUSTS AROUND 25
KNOTS.
.OUTLOOK...
SAT NIGHT THRU SUN...VFR.
SUN NGT-WED...RESTRICTIONS IN -RA...ESP. SUN NGT-MON NGT.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DGM
LONG TERM...MDP/PCF
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1045 AM EDT FRI APR 17 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE ACROSS CENTRAL NEW YORK EARLY THIS
AFTERNOON AND NORTHEAST PENNSYLVANIA BY LATE AFTERNOON. THIS FRONT
WILL TRIGGER A FEW SHOWERS WITH AN ISOLATED THUNDERSTORM IN
NORTHEAST PENNSYLVANIA. ANOTHER COLD FRONT WILL PASS ACROSS THE
REGION SATURDAY. THIS FRONT COULD TRIGGER SOME SHOWERS IN
NORTHERN AND EASTERN NEW YORK WITH MAINLY DRY WEATHER IN CENTRAL
NEW YORK AND NORTHEAST PENNSYLVANIA. HIGH PRESSURE AND COOLER
WEATHER WILL BUILD ACROSS THE REGION FOR SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WATER VAPOR IMAGERY SHOWS A SHORT WAVE MOVING ACROSS THE EASTERN
GREAT LAKES AND EASTERN OHIO VALLEY THIS MORNING. THIS WAVE WILL
PUSH A WEAK FRONT ACROSS THE REGION THIS AFTERNOON WITH SOME LL
DRY ADVECTION BEHIND THE FRNT. THE FRONT AND LIFT ASSCTD WITH THE
SHRT WAVE WILL TRIGGER ISLD TO SCT SHRA ACRS C NY/NE PA THIS
AFTERNOON. THE FRNT COMES THRU AT MAX HEATING LATE THIS AFTERNOON
ESP IN NE PA. CAPES ON THE HI RES MODELS NOW ARE RANGING FROM
ARND 250 TO 500 J/KG IN NE PA ARND 21Z WITH THE HIGHER RESOLUTION
MODELS SHOWING SCT CONVECTIVE CELLS FORMING ON SIMULATED RADAR
FIELDS. THE BULK SHEAR IS ARND 20 KNOTS 0-1 KM AND 0-3 KM AND ABT
35 KNOTS 0-6 KM. FORCING IS NOT STRG BUT I HAVE ADDED ISLD TSRA TO
NE PA GRIDS. I MAY HAVE TO ADJUST THIS UP EVEN MORE AS RECENT RAP
AND HRRR RUNS HAVE MORE CAPE. WILL CONT TO MONITOR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
NW FLOW ALOFT TNGT WITH WEAK SFC FEATURES WILL RESULT IN A QUIET
PD WITH LGT WINDS AND BKN CLDS. WHILE A SHWR CAN/T BE RULED
OUT...NOT ENUF OF A CHANCE TO INCLUDE IN THE FCST ATTM.
SATURDAY WILL SEE A SHRT WV PASSING THRU NRN NEW ENG AND SOME LATE
DAY CAA IN THE WAKE OF THE WV. MODELS SHOW VERY DRY AIR OVER THE
AREA WITH THE BEST FRCG STAYING TO THE NE. SOME INSTABILITY LIKELY
WITH THE LWRD HGTS BUT DRY AIR SHD INHIBIT ANY SHWRS FROM FRMG IN
THE FCST AREA...ALTHOUGH NRN ONEIDA WILL BE CLOSE.
UPR RDGG OVER THE GREAT LAKES WILL ALLOW SFC HIPRES TO SLIDE INTO
THE AREA ON SUNDAY. TEMPS WILL BE A BIT LWR WITH THE CAA BUT DRIER
AIR SHD ALLOW FOR MSTLY SUNNY SKIES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
0245 AM UPDATE...ONLY MADE A FEW ADJUSTMENTS TO PREVIOUS FORECAST
MADE DURING THE DAY SHIFT THURSDAY. MAIN CHANGE WAS TO ADJUST HIGH
TEMPS DOWN FOR MONDAY, WEDNESDAY, AND THURSDAY OF NEXT WEEK AS
GUIDANCE CONTINUES TO INDICATE WE WILL BE COOLER AND MORE
UNSETTLED UNDER THE INFLUENCE OF AN UPPER LEVEL TROUGH.
445 PM THURSDAY UPDATE... MODELS IN GOOD AGREEMENT ON MOIST
OCCLUDED FRONT LIKELY TO BRING RAIN AS IT SWEEPS THROUGH THE
REGION LATE SUNDAY NIGHT THROUGH MONDAY. SHOWALTER INDICES ONLY
GET TO AROUND ZERO...SHOWING ONLY SMALLEST HINT OF ELEVATED
INSTABILITY...SO CHANCE OF EMBEDDED THUNDER DURING THAT PERIOD
LOOKS MINIMAL TO NONE. QUARTER TO HALF INCH OF RAIN LOOKS QUITE
DOABLE HOWEVER.
CUTOFF LOW CURRENTLY OVER FOUR CORNERS REGION...IS DEPICTED BY
GFS-ECMWF TO MERGE WITH A DIGGING NORTHERN STREAM TROUGH OVER THE
MIDWEST THIS WEEKEND. THOSE FEATURES WILL COMBINE INTO A NEW
LARGER CUTOFF LOW...THE CENTER OF WHICH WILL SLOWLY SLOG ITS WAY
OVER THE WESTERN GREAT LAKES NEXT WEEK. THIS UPPER LOW WILL HAVE A
LARGE FOOTPRINT WITH DISTURBANCES-WAVES ROTATING AROUND IT ACROSS
GREAT LAKES TO NORTHEAST. MODELS DISAGREE ON LOCATION OF UPPER LOW
CENTER BY THURSDAY /EITHER CENTRAL GREAT LAKES AND HEADING EAST...OR
A BIT FURTHER NORTH AND STILL PARKED/ YET EITHER WAY IT LOOKS
RATHER TROUGHY AND UNSETTLED WITH CYCLONIC FLOW OVER OUR REGION.
SO AFTER BRIEFLY MILDER CONDITIONS TUESDAY...WE SHOULD TREND BACK
TO NEAR CLIMATOLOGY FOR TEMPERATURES WEDNESDAY-THURSDAY. IF THE
UPPER LOW SHIFTS EAST AS PER ECMWF...POSSIBLY A LITTLE COOLER THAN
CLIMATOLOGY.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
12Z UPDATE... SHOWERS WILL CONTINUE DIMINISHING OVER THE AREA FROM
WEST TO EAST THIS MORNING HOWEVER STILL EXPECTING AT LEAST MVFR
FUEL ALT CONDITIONS FOR MOST SITES UNTIL THIS AFTERNOON DUE TO LOW
CIGS. FOR KBGM, CIGS WILL LIKELY DROP AT TIMES TO HIGH END IFR
THIS MORNING WITH IFR VISBYS LIKELY AT TIMES FOR KRME. CONDITIONS
IMPROVE TO VFR AT ALL SITES THIS AFTERNOON WITH SKIES CLEARING OUT
TONIGHT.
WINDS WILL GENERALLY BE W/SW AROUND 5 KNOTS EARLY THIS MORNING
BECOMING W/NW 5 TO 10 KNOTS BY THIS AFTERNOON.
.OUTLOOK...
SAT THRU SUN...VFR.
SUN NGT-MON-TUE...RESTRICTIONS IN -RA...ESP. SUN NGT-MON.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DGM
LONG TERM...MDP/PCF
AVIATION...PCF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1027 AM EDT FRI APR 17 2015
.SYNOPSIS...
A WEAK PRESSURE PATTERN WILL CONTINUE TO BRING MOSTLY CLOUDY SKIES
AND DRIZZLY CONDITIONS TODAY. SOME IMPROVEMENT CAN BE EXPECTED
SATURDAY AND SUNDAY. A WARM FRONT BRING ANOTHER GOOD CHANCE OF
RAIN LATER SUNDAY. NEXT WEEK LOOKS TO BE DRY AND SEASONABLE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM FRIDAY...LIGHT SHOWERS AND DRIZZLE CONTINUE ACROSS
THE AREA THIS MORNING. SOME OF THE ACTIVITY NEAR WILMINGTON HAS
BEEN A LITTLE HEAVIER. HRRR AND LATEST NAM SHOW A CONVECTIVE
SIGNAL IN THEIR RESPECTIVE MODELS WHICH SHOW SHOWERS INCREASING
THIS AFTERNOON. WILL MAINTAIN LOW CHANCE POPS AREAWIDE. FORECAST
EMPHASIS THEN SHIFTS TO POSSIBLE OVERNIGHT ACTIVITY WITH THE
SHORTWAVE IN THE TENNESSEE VALLEY. THE LATEST NAM IS A LITTLE LESS
ROBUST BUT WILL WAIT UNTIL THE 1200 UTC GFS ARRIVES TO MAKE ANY
CHANGES.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...THE FORECAST AREA WILL BE UNDER THE CONTROL
OF NEARLY A FULL LATITUDE AMPLIFIED UPPER RIDGE THIS PERIOD. THE
ROUGHLY NORTH TO SOUTH UPPER RIDGE AXIS WILL REMAIN WEST OF THE
ILM CWA DURING SAT. WITH WEAK HIGH PRESSURE AT THE SFC AND MAINLY
SUBSIDENCE ALOFT...THE CHANCE FOR CONVECTION HAS BEEN KEPT TO A
MINIMUM AND WILL ONLY INDICATE SEA BREEZE INDUCED CONVECTION.
THE UPPER RIDGE AXIS WILL DRIFT TO THE EAST AND ACROSS THE ILM
CWA SAT NIGHT...AND FINALLY OFF THE CAROLINA COASTS SUN THRU SUN
NIGHT. MODELS ARE IN DECENT AGREEMENT WITH THIS SCENARIO PANNING
OUT. A POTENT S/W MID-LEVEL TROF OR ONE COULD CALL IT A
CLIPPER...WILL DIVE SE AND RACE ACROSS THE NE STATES SAT...AND
OFFSHORE FROM NEW ENGLAND BY SUNDAY. THE SFC COLD FRONT
ASSOCIATED WITH THIS CLIPPER WILL BACKDOOR THE ILM CWA ON SUN
FOLLOWED BY A WEDGE OF HIGH PRESSURE FROM THE NORTH THRU SUN
NIGHT. POPS WILL BE ON THE LOW SIDE IF ANY WITH THIS FRONTAL
PASSAGE.
THE CENTRAL U.S. CUTOFF LOW IS PROGGED TO OPEN UP AND HOOK ONTO A
S/W UPPER TROF DIVING OUT OF CENTRAL CANADA BY THE END OF THIS
PERIOD. LOOK FOR AN AMPLIFYING PATTERN ALOFT WITH THE FA COMING
UNDER THE INFLUENCE OF THE FULL LATITUDE UPPER TROF ACROSS THE
CENTRAL U.S. BY LATE SUN. WITH SW FLOW ALOFT...GULF OF MEXICO
MOISTURE WILL BECOME WELL TAPPED BY MID TO LATE SUN. A S/W MID-
LEVEL TROF ROTATING THRU THE WELL AMPLIFIED UPPER PATTERN...WILL
PUSH ACROSS THE FA BY LATE SUN INTO EARLY MON. THE DYNAMICS
ASSOCIATED WITH IT AND THE STALLED SFC BOUNDARY IN THE VICINITY...
WILL BE ENOUGH TO INCREASE POPS TO LIKELY OR POSSIBLY
CATEGORICAL...BY AND DURING SUN NIGHT ACROSS THE ENTIRE ILM CWA.
AS FOR TEMPS THIS PERIOD...WILL GO WITH AT OR SLIGHTLY ABOVE CLIMO
WHICH IS BASICALLY 70S TO AROUND 80 FOR HIGHS...AND 50S TO AROUND
60 FOR LOWS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...A WELL AMPLIFIED LONGWAVE UPPER PATTERN TO
BECOME ESTABLISHED THIS PERIOD. THE ILM CWA WILL PRIMARILY BE
UNDER THE INFLUENCED OF NEARLY A FULL LATITUDE UPPER TROF...WITH
THE UPPER TROF N-S AXIS REMAINING WEST OF THE ILM CWA THIS PERIOD.
ITS ONLY TOWARD THE END OF THE LONG TERM PERIOD WHEN MODELS WANT
TO FLATTEN THIS AMPLIFIED FLOW...WITH MODELS DIVERGING FROM ONE
ANOTHER FOR THEIR RESPECTIVE SOLUTIONS BY THE MID-LATE WEEK PERIOD
OF NEXT WEEK.
AS FOR POPS...THE PCPN FROM SUN NIGHT WILL EXTEND INTO EARLY MON
BEFORE MOVING OFF TO THE NE. A COLD FRONT WILL APPROACH AND PUSH
ACROSS THE ILM CWA MON NIGHT INTO TUE...WITH IDLEST CHANCE POPS
BEING ADVERTISED. WEAK HIGH PRESSURE WILL FOLLOW FROM THE GULF
COAST STATES TUE THRU MUCH OF THE MID-WEEK PERIOD OF NEXT WEEK.
THIS COULD END UP FINALLY BEING A PERIOD OF DRYING OUT ACROSS THE
ILM CWA.
AS FOR MAX/MIN TEMPS THIS PERIOD...STAYED AT OR SLIGHTLY HIGHER
THAN CLIMO FOR THIS TIME OF THE YEAR. DO NOT SEE ANY INFLUENCE OF
COOL OR COLDER THAN NORMAL AIR MASSES AFFECTING THE ILM CWA DURING
THIS TIME PERIOD.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...LOW PRESSURE REMAINS OFFSHORE...WITH SMALL POCKETS OF
LIGHT SHOWERS MOVING ONSHORE. MOST OF THE SHOWERS WILL REMAIN AWAY
FROM THE TERMINALS...BUT A SMALL SHOWER IS NOT OUT OF THE QUESTION.
NORTHEAST FLOW IS EXPECTED TO CONTINUE TODAY...WITH MAINLY MVFR
CEILINGS. TONIGHT...A MORE ORGANIZED SHORT WAVE WILL MOVE WEST TO
EAST ACROSS THE REGION...WITH MORE ORGANIZED PRECIPITATION EXPECTED.
CEILINGS MAY LOWER TO IFR...BUT WILL KEEP PREDOMINATELY MVFR AT THIS
TIME.
EXTENDED OUTLOOK...VFR SATURDAY. SHOWERS MOVING BACK INTO THE REGION
LATE SATURDAY NIGHT THROUGH MONDAY MORNING. BECOMING VFR MONDAY
AFTERNOON THROUGH TUE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM FRIDAY...WINDS AND SEAS ON THE WAY DOWN THIS MORNING
WITH JMPN7 REPORTING EIGHT KNOTS FROM THE NORTHEAST. SEAS AT 41110
NOW BELOW FIVE FEET. FORECAST LOOKS GOOD WITH HEADLINES EXPIRING
AS THE DAY PROCEDES.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...SATURDAY TO START OFF WITH A WEAK SFC
PRESSURE PATTERN AND GRADIENT. BY THE END OF THE DAY AND DURING
SAT NIGHT...A BACKDOOR CUP IS EXPECTED TO OCCUR. IMMEDIATELY
FOLLOWING THE CUP...A WEDGE OF HIGH PRESSURE WILL NOSE DOWN FROM
SE CANADA AND THE NE STATES SAT NIGHT THRU SUN. THE SFC PRESSURE
GRADIENT WILL TIGHTEN FOR THE REMAINDER OF THE SHORT TERM PERIOD
WITH NE WINDS REACHING SCEC OR POSSIBLY SCA THRESHOLDS LATE SAT
INTO EARLY SUN. A COASTAL FRONT/TROF WILL DEVELOP AND BECOME
ESTABLISHED JUST OFFSHORE BY LATE SUN...BEFORE FINALLY LIFTING
INLAND AND NORTHWARD AT THE SAME TIME SUN NIGHT. WINDS WILL VEER
TO THE E THEN SE BY LATE SUN. THE SFC PG WILL FURTHER TIGHTEN AND
COULD SEE WINDS AGAIN REACH SCEC/SCA THRESHOLDS. THE ONSHORE FLOW
WILL CAPITALIZE ON A DECENT FETCH RESULTING IN SIGNIFICANT SEAS
BUILDING FROM LATE SAT THRU SUN NIGHT...AND LIKELY REACHING SCA
THRESHOLDS.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...COULD ARGUE THAT A SFC WARM FRONT WILL HAVE
PUSHED NORTHEAST OF THE LOCAL ILM WATERS COME MONDAY MORNING.
THUS THE STRONG SE-S WINDS WILL VEER TO THE SW AT REDUCED SPEEDS
AS THE SFC PG RELAXES SOME. THIS WILL BE SHORT-LIVED AS THE
GRADIENT ROOTEDNESS AGAIN AHEAD OF THE APPROACHING COLD
FRONT...WHICH IS PROGGED TO PUSH ACROSS THE LOCAL WATERS BY
DAYBREAK TUE. WINDS OVER THE WATERS WILL FURTHER VEER TO THE W-NW
AS RIDGING FROM WEAK SFC HIGH CENTERED OVER THE GULF COAST STATES
AFFECTS THE LOCAL WATERS ON TUESDAY. MODELS NOW INDICATE A
SECONDARY SFC COLD FRONT OR SFC TROF TO PUSH ACROSS THE LOCAL
WATERS TUE NIGHT...WHICH WILL FURTHER VEER THE WINDS TO THE NW-N.
SCEC OR SCA THRESHOLDS WILL REMAIN POSSIBLE AT THE START OF THIS
PERIOD...FADING QUICKLY BY LATE TUE NIGHT. SIGNIFICANT SEAS WILL
PEAK DURING MONDAY...THAN WILL INDICATE A SUBSIDING TREND THERE-
AFTER AS WINDS VEER TO EVENTUALLY AN OFFSHORE TRAJECTORY BY LATE
TUE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR AMZ254-256.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR AMZ250-
252.
&&
$$
SYNOPSIS...SHK
NEAR TERM...SHK
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...HDL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
955 PM CDT SAT APR 18 2015
.UPDATE...
ISSUED AT 955 PM CDT SAT APR 18 2015
ALTHOUGH THE 01 UTC RAP/HRRR ARE OVERDOING THE QPF IN MOST
AREAS...THEY HAVE A GOOD HANDLE ON THE AREA OF PRECIPITATION AND
HAVE UTILIZED THIS BLEND FOR POPS THROUGH THE NIGHT AND INTO
SUNDAY. BEST PRECIPITATION CHANCES WILL REMAIN OVER THE SOUTHEAST
FORECAST AREA. EXPECT PRECIPITATION TO FILL IN OVER THE JAMES
RIVER VALLEY OVER THE NEXT FEW HOURS. PRECIPITATION BAND FROM
SOUTHWEST INTO NORTH CENTRAL NORTH DAKOTA WILL MOVE ACROSS CENTRAL
NORTH DAKOTA AS WELL...WITH BEST PRECIPITATION CHANCES OVER
BISMARCK THROUGH AROUND MIDNIGHT. PRECIPITATION IS EXPECTED TO
MOVE OUT OF THE JAMES RIVER VALLEY AROUND 12-14Z...LOWERED POPS
ACROSS THE AREA EARLY MORNING...THEN BUMPED THEM UP MID TO LATE
MORNING INTO THE AFTERNOON AS WRAP AROUND MOISTURE MOVES INTO THE
AREA ON THE BACK SIDE OF THE EXITING SYSTEM.
UPDATE ISSUED AT |748 PM CDT SAT APR 18 2015
QUICK UPDATE FOR POPS BASED ON LATEST RADAR...ALSO REMOVED
THUNDER OVER THE SOUTHWEST. HEAVIEST SHOWERS LOOK TO REMAIN OVER
THE FAR SOUTH CENTRAL AND INTO EASTERN NORTH DAKOTA THIS EVENING.
BAND MOVING EAST ACROSS THE CENTRAL FROM AROUND MINOT TO GARRISON
TO HEBRON SHOULD HELP MOISTEN THE ATMOSPHERE NEAR KBIS THIS
EVENING. SHOWERS IN THE FAR SOUTH CENTRAL MOVING TOWARD BISMARCK
ARE NOW DISSIPATING ON THE NORTHERN FRINGE. 19 APRIL 00 UTC
SOUNDING STILL SHOWS QUITE A BIT OF DRY AIR BELOW THE MID AND
UPPER LEVEL MOISTURE BEGINNING AROUND 10K FEET.
UPDATE ISSUED AT 638 PM CDT SAT APR 18 2015
UPPER LEVEL LOW OVER SOUTHEAST COLORADO WITH A SHORTWAVE TROUGH
LIFTING NORTH THROUGH WESTERN SOUTH DAKOTA IS PUSHING SHOWERS INTO
CENTRAL NORTH DAKOTA. A NORTHERN STREAM WAVE WITH MORE INSOLATION
TO WORK WITH IS PRODUCING A LINE OF POST FRONTAL SHOWERS AND
ISOLATED THUNDER OVER WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE
THUNDER IS LIMITED TO THE SOUTHWEST...AND WITH THE LOSS OF DAYTIME
HEATING...DO NOT EXPECT THUNDER TO CONTINUE MUCH LONGER. WILL KEEP
A MENTION THROUGH THE EARLY EVENING. EXPECT SHOWERS TO INCREASE
OVER SOUTH CENTRAL INTO EASTERN NORTH DAKOTA LATER THIS EVENING AS
THE SHORTWAVES LIFTING NORTH AND TRACKING EAST CONVERGE OVER
CENTRAL NORTH DAKOTA...AND THEN MOVE INTO BETTER MOISTURE AND
SURFACE SUPPORT AS THE SYSTEM MOVES INTO EASTERN NORTH DAKOTA LATE
TONIGHT. ADJUSTED POPS/SKY COVER BASED MAINLY ON SHORT TERM
CONSENSUS MODEL AND LATEST RADAR. OTHERWISE NO SIGNIFICANT CHANGES
FROM THE GOING FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 315 PM CDT SAT APR 18 2015
RAINFALL POTENTIAL THROUGH TONIGHT HIGHLIGHTS THE SHORT TERM
FORECAST.
AS OF 1930 UTC...A COLD FRONT WAS JUST ENTERING NORTHWEST NORTH
DAKOTA AND WILL CONTINUE TO PROPAGATE THROUGH CENTRAL NORTH DAKOTA
THIS EVENING. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WITH
WEAK INSTABILITY HAVE DEVELOPED ALONG THIS FRONT AND WILL APPROACH
THE HIGHWAY 83 CORRIDOR BY 01-02 UTC. AS CYCLOGENESIS OCCURS
ACROSS EASTERN SOUTH DAKOTA THROUGH THE NIGHT AND THE NORTHERN STREAM
WAVE ASSOCIATED WITH THE COLD FRONT PHASES WITH THE LOW TO THE
SOUTH...RAINFALL COVERAGE WILL INCREASE ACROSS CENTRAL NORTH
DAKOTA THROUGH THE EVENING AND NIGHT. THEREAFTER...A WINDY SUNDAY
IS FORECAST IN THE WAKE OF THE NOW DEEPENING LOW ACROSS MINNESOTA.
AT THIS TIME...WIND GUSTS APPEAR TO STAY BELOW ADVISORY CRITERIA
WITH 30 TO 35 KTS TO MIX IN COLD AIR ADVECTION. SCATTERED LIGHT
RAIN SHOWERS ARE ALSO EXPECTED IN WRAP AROUND MOISTURE WITH
PERHAPS A FEW SNOWFLAKES MIXING IN SUNDAY MORNING AS TEMPERATURES
FALL INTO THE MID 30S NORTHWEST AND NORTH CENTRAL. GIVEN GOOD
AGREEMENT...WILL WEIGH HEAVILY ON THE 16-18 UTC HRRR ITERATIONS
BLENDED TO THE GLOBAL 12 UTC DETERMINISTIC AND ENSEMBLE SUITE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CDT SAT APR 18 2015
WINDY WITH SCATTERED SHOWERS TO BEGIN THE EXTENDED...COOL AND DRY
THROUGH THE REMAINDER OF THE WEEK.
AS THE MAIN SURFACE LOW ENTERS NORTHERN MINNESOTA AND SOUTHERN
CANADA...MOISTURE SHOULD WRAP AROUND THE BACKSIDE...PROVIDING
NORTH DAKOTA WITH SOME SCATTERED LIGHT RAIN. THE HIGH RESOLUTION
SHORT TERM MODELS ARE A LITTLE MORE ROBUST WITH PRECIPITATION
COVERAGE THAN THE GLOBAL MODELS (ECMWF/GFS). WITH THE LOW
REMAINING NEARBY AND REMAINING UNDER THE INFLUENCE OF A FAVORABLE
JET STREAK...LIGHT SHOWERS HERE AND THERE AREN`T OUT OF THE
QUESTION THROUGH TUESDAY. GUSTY WINDS ARE EXPECTED THOUGH THE DAY
SUNDAY AND MONDAY AS THE PRESSURE GRADIENT TIGHTENS WITH THE
SURFACE LOW DEEPENING AND PROPAGATING TOWARD THE GREAT LAKES.
THESE GUSTY NORTHWEST WINDS WILL BE ADVECTING DRIER AIR INTO THE
AREA. THIS COULD CREATE RATHER CRITICAL FIRE CONDITIONS MONDAY AS
RELATIVE HUMIDITY DROPS BELOW 20 PERCENT.
THROUGH THE REMAINDER OF THE WORK WEEK...UPPER LOW SLOWLY WORKS
OFF TO THE EAST KEEPING NORTH/NORTHWESTERLY FLOW OVER OUR AREA.
WITH THE EXCEPTION OF ISOLATED SHOWERS EARLY THIS WEEK...DRY
WEATHER IS EXPECTED. TEMPERATURES WILL REMAIN A BIT BELOW
AVERAGE WITH READINGS IN THE 50S FOR HIGHS AND 20S/30S FOR LOWS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 955 PM CDT SAT APR 18 2015
A COLD FRONT FROM NORTH CENTRAL INTO WESTERN NORTH DAKOTA THIS
EVENING WILL MOVE ACROSS THE CENTRAL THIS EVENING AND MERGE WITH A
LOW DEVELOPING ACROSS EASTERN SOUTH DAKOTA TONIGHT. SCATTERED RAIN
SHOWERS ARE EXPECTED TO MOVE FROM WESTERN INTO CENTRAL NORTH
DAKOTA THIS EVENING...AND BECOME MORE WIDESPREAD AS THEY MERGE
WITH SHOWERS MOVING IN FROM THE SOUTH. EMBEDDED MVFR CONDITIONS
POSSIBLE IN RAIN.
&&
.FIRE WEATHER...
ISSUED AT 315 PM CDT SAT APR 18 2015
CRITICAL FIRE WEATHER CONDITIONS MAY BE POSSIBLE ON MONDAY...AND
THIS WILL NEED TO BE MONITORED. WHILE TEMPERATURES WILL ONLY BE IN
THE 50S...MINIMUM RELATIVE HUMIDITY LEVELS OF 15 TO 20 PERCENT AND
NORTHWEST WINDS OF 25 TO 35 MPH ARE POSSIBLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AYD
LONG TERM...AJ
AVIATION...TWH
FIRE WEATHER...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
748 PM CDT SAT APR 18 2015
.UPDATE...
ISSUED AT |748 PM CDT SAT APR 18 2015
QUICK UPDATE FOR POPS BASED ON LATEST RADAR...ALSO REMOVED
THUNDER OVER THE SOUTHWEST. HEAVIEST SHOWERS LOOK TO REMAIN OVER
THE FAR SOUTH CENTRAL AND INTO EASTERN NORTH DAKOTA THIS EVENING.
BAND MOVING EAST ACROSS THE CENTRAL FROM AROUND MINOT TO GARRISON
TO HEBRON SHOULD HELP MOISTEN THE ATMOSPHERE NEAR KBIS THIS
EVENING. SHOWERS IN THE FAR SOUTH CENTRAL MOVING TOWARD BISMARCK
ARE NOW DISSIPATING ON THE NORTHERN FRINGE. 19 APRIL 00 UTC
SOUNDING STILL SHOWS QUITE A BIT OF DRY AIR BELOW THE MID AND
UPPER LEVEL MOISTURE BEGINNING AROUND 10K FEET.
UPDATE ISSUED AT 638 PM CDT SAT APR 18 2015
UPPER LEVEL LOW OVER SOUTHEAST COLORADO WITH A SHORTWAVE TROUGH
LIFTING NORTH THROUGH WESTERN SOUTH DAKOTA IS PUSHING SHOWERS INTO
CENTRAL NORTH DAKOTA. A NORTHERN STREAM WAVE WITH MORE INSOLATION
TO WORK WITH IS PRODUCING A LINE OF POST FRONTAL SHOWERS AND
ISOLATED THUNDER OVER WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE
THUNDER IS LIMITED TO THE SOUTHWEST...AND WITH THE LOSS OF DAYTIME
HEATING...DO NOT EXPECT THUNDER TO CONTINUE MUCH LONGER. WILL KEEP
A MENTION THROUGH THE EARLY EVENING. EXPECT SHOWERS TO INCREASE
OVER SOUTH CENTRAL INTO EASTERN NORTH DAKOTA LATER THIS EVENING AS
THE SHORTWAVES LIFTING NORTH AND TRACKING EAST CONVERGE OVER
CENTRAL NORTH DAKOTA...AND THEN MOVE INTO BETTER MOISTURE AND
SURFACE SUPPORT AS THE SYSTEM MOVES INTO EASTERN NORTH DAKOTA LATE
TONIGHT. ADJUSTED POPS/SKY COVER BASED MAINLY ON SHORT TERM
CONSENSUS MODEL AND LATEST RADAR. OTHERWISE NO SIGNIFICANT CHANGES
FROM THE GOING FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 315 PM CDT SAT APR 18 2015
RAINFALL POTENTIAL THROUGH TONIGHT HIGHLIGHTS THE SHORT TERM
FORECAST.
AS OF 1930 UTC...A COLD FRONT WAS JUST ENTERING NORTHWEST NORTH
DAKOTA AND WILL CONTINUE TO PROPAGATE THROUGH CENTRAL NORTH DAKOTA
THIS EVENING. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WITH
WEAK INSTABILITY HAVE DEVELOPED ALONG THIS FRONT AND WILL APPROACH
THE HIGHWAY 83 CORRIDOR BY 01-02 UTC. AS CYCLOGENESIS OCCURS
ACROSS EASTERN SOUTH DAKOTA THROUGH THE NIGHT AND THE NORTHERN STREAM
WAVE ASSOCIATED WITH THE COLD FRONT PHASES WITH THE LOW TO THE
SOUTH...RAINFALL COVERAGE WILL INCREASE ACROSS CENTRAL NORTH
DAKOTA THROUGH THE EVENING AND NIGHT. THEREAFTER...A WINDY SUNDAY
IS FORECAST IN THE WAKE OF THE NOW DEEPENING LOW ACROSS MINNESOTA.
AT THIS TIME...WIND GUSTS APPEAR TO STAY BELOW ADVISORY CRITERIA
WITH 30 TO 35 KTS TO MIX IN COLD AIR ADVECTION. SCATTERED LIGHT
RAIN SHOWERS ARE ALSO EXPECTED IN WRAP AROUND MOISTURE WITH
PERHAPS A FEW SNOWFLAKES MIXING IN SUNDAY MORNING AS TEMPERATURES
FALL INTO THE MID 30S NORTHWEST AND NORTH CENTRAL. GIVEN GOOD
AGREEMENT...WILL WEIGH HEAVILY ON THE 16-18 UTC HRRR ITERATIONS
BLENDED TO THE GLOBAL 12 UTC DETERMINISTIC AND ENSEMBLE SUITE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CDT SAT APR 18 2015
WINDY WITH SCATTERED SHOWERS TO BEGIN THE EXTENDED...COOL AND DRY
THROUGH THE REMAINDER OF THE WEEK.
AS THE MAIN SURFACE LOW ENTERS NORTHERN MINNESOTA AND SOUTHERN
CANADA...MOISTURE SHOULD WRAP AROUND THE BACKSIDE...PROVIDING
NORTH DAKOTA WITH SOME SCATTERED LIGHT RAIN. THE HIGH RESOLUTION
SHORT TERM MODELS ARE A LITTLE MORE ROBUST WITH PRECIPITATION
COVERAGE THAN THE GLOBAL MODELS (ECMWF/GFS). WITH THE LOW
REMAINING NEARBY AND REMAINING UNDER THE INFLUENCE OF A FAVORABLE
JET STREAK...LIGHT SHOWERS HERE AND THERE AREN`T OUT OF THE
QUESTION THROUGH TUESDAY. GUSTY WINDS ARE EXPECTED THOUGH THE DAY
SUNDAY AND MONDAY AS THE PRESSURE GRADIENT TIGHTENS WITH THE
SURFACE LOW DEEPENING AND PROPAGATING TOWARD THE GREAT LAKES.
THESE GUSTY NORTHWEST WINDS WILL BE ADVECTING DRIER AIR INTO THE
AREA. THIS COULD CREATE RATHER CRITICAL FIRE CONDITIONS MONDAY AS
RELATIVE HUMIDITY DROPS BELOW 20 PERCENT.
THROUGH THE REMAINDER OF THE WORK WEEK...UPPER LOW SLOWLY WORKS
OFF TO THE EAST KEEPING NORTH/NORTHWESTERLY FLOW OVER OUR AREA.
WITH THE EXCEPTION OF ISOLATED SHOWERS EARLY THIS WEEK...DRY
WEATHER IS EXPECTED. TEMPERATURES WILL REMAIN A BIT BELOW
AVERAGE WITH READINGS IN THE 50S FOR HIGHS AND 20S/30S FOR LOWS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 748 PM CDT SAT APR 18 2015
A COLD FRONT FROM NORTH CENTRAL INTO WESTERN NORTH DAKOTA EARLY
THIS EVENING WILL MOVE ACROSS THE CENTRAL THIS EVENING AND MERGE
WITH A LOW DEVELOPING ACROSS EASTERN SOUTH DAKOTA TONIGHT.
SCATTERED RAIN SHOWERS ARE EXPECTED TO MOVE FROM WESTERN INTO
CENTRAL NORTH DAKOTA THIS EVENING...AND BECOME MORE WIDESPREAD AS
THEY MERGE WITH SHOWERS MOVING IN FROM THE SOUTH. EMBEDDED MVFR
CONDITIONS POSSIBLE IN RAIN.
&&
.FIRE WEATHER...
ISSUED AT 315 PM CDT SAT APR 18 2015
CRITICAL FIRE WEATHER CONDITIONS MAY BE POSSIBLE ON MONDAY...AND
THIS WILL NEED TO BE MONITORED. WHILE TEMPERATURES WILL ONLY BE IN
THE 50S...MINIMUM RELATIVE HUMIDITY LEVELS OF 15 TO 20 PERCENT AND
NORTHWEST WINDS OF 25 TO 35 MPH ARE POSSIBLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AYD
LONG TERM...AJ
AVIATION...TWH
FIRE WEATHER...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
638 PM CDT SAT APR 18 2015
.UPDATE...
ISSUED AT 638 PM CDT SAT APR 18 2015
UPPER LEVEL LOW OVER SOUTHEAST COLORADO WITH A SHORTWAVE TROUGH
LIFTING NORTH THROUGH WESTERN SOUTH DAKOTA IS PUSHING SHOWERS INTO
CENTRAL NORTH DAKOTA. A NORTHERN STREAM WAVE WITH MORE INSOLATION
TO WORK WITH IS PRODUCING A LINE OF POST FRONTAL SHOWERS AND
ISOLATED THUNDER OVER WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE
THUNDER IS LIMITED TO THE SOUTHWEST...AND WITH THE LOSS OF DAYTIME
HEATING...DO NOT EXPECT THUNDER TO CONTINUE MUCH LONGER. WILL KEEP
A MENTION THROUGH THE EARLY EVENING. EXPECT SHOWERS TO INCREASE
OVER SOUTH CENTRAL INTO EASTERN NORTH DAKOTA LATER THIS EVENING AS
THE SHORTWAVES LIFTING NORTH AND TRACKING EAST CONVERGE OVER
CENTRAL NORTH DAKOTA...AND THEN MOVE INTO BETTER MOISTURE AND
SURFACE SUPPORT AS THE SYSTEM MOVES INTO EASTERN NORTH DAKOTA LATE
TONIGHT. ADJUSTED POPS/SKY COVER BASED MAINLY ON SHORT TERM
CONSENSUS MODEL AND LATEST RADAR. OTHERWISE NO SIGNIFICANT CHANGES
FROM THE GOING FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 315 PM CDT SAT APR 18 2015
RAINFALL POTENTIAL THROUGH TONIGHT HIGHLIGHTS THE SHORT TERM
FORECAST.
AS OF 1930 UTC...A COLD FRONT WAS JUST ENTERING NORTHWEST NORTH
DAKOTA AND WILL CONTINUE TO PROPAGATE THROUGH CENTRAL NORTH DAKOTA
THIS EVENING. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WITH
WEAK INSTABILITY HAVE DEVELOPED ALONG THIS FRONT AND WILL APPROACH
THE HIGHWAY 83 CORRIDOR BY 01-02 UTC. AS CYCLOGENESIS OCCURS
ACROSS EASTERN SOUTH DAKOTA THROUGH THE NIGHT AND THE NORTHERN STREAM
WAVE ASSOCIATED WITH THE COLD FRONT PHASES WITH THE LOW TO THE
SOUTH...RAINFALL COVERAGE WILL INCREASE ACROSS CENTRAL NORTH
DAKOTA THROUGH THE EVENING AND NIGHT. THEREAFTER...A WINDY SUNDAY
IS FORECAST IN THE WAKE OF THE NOW DEEPENING LOW ACROSS MINNESOTA.
AT THIS TIME...WIND GUSTS APPEAR TO STAY BELOW ADVISORY CRITERIA
WITH 30 TO 35 KTS TO MIX IN COLD AIR ADVECTION. SCATTERED LIGHT
RAIN SHOWERS ARE ALSO EXPECTED IN WRAP AROUND MOISTURE WITH
PERHAPS A FEW SNOWFLAKES MIXING IN SUNDAY MORNING AS TEMPERATURES
FALL INTO THE MID 30S NORTHWEST AND NORTH CENTRAL. GIVEN GOOD
AGREEMENT...WILL WEIGH HEAVILY ON THE 16-18 UTC HRRR ITERATIONS
BLENDED TO THE GLOBAL 12 UTC DETERMINISTIC AND ENSEMBLE SUITE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CDT SAT APR 18 2015
WINDY WITH SCATTERED SHOWERS TO BEGIN THE EXTENDED...COOL AND DRY
THROUGH THE REMAINDER OF THE WEEK.
AS THE MAIN SURFACE LOW ENTERS NORTHERN MINNESOTA AND SOUTHERN
CANADA...MOISTURE SHOULD WRAP AROUND THE BACKSIDE...PROVIDING
NORTH DAKOTA WITH SOME SCATTERED LIGHT RAIN. THE HIGH RESOLUTION
SHORT TERM MODELS ARE A LITTLE MORE ROBUST WITH PRECIPITATION
COVERAGE THAN THE GLOBAL MODELS (ECMWF/GFS). WITH THE LOW
REMAINING NEARBY AND REMAINING UNDER THE INFLUENCE OF A FAVORABLE
JET STREAK...LIGHT SHOWERS HERE AND THERE AREN`T OUT OF THE
QUESTION THROUGH TUESDAY. GUSTY WINDS ARE EXPECTED THOUGH THE DAY
SUNDAY AND MONDAY AS THE PRESSURE GRADIENT TIGHTENS WITH THE
SURFACE LOW DEEPENING AND PROPAGATING TOWARD THE GREAT LAKES.
THESE GUSTY NORTHWEST WINDS WILL BE ADVECTING DRIER AIR INTO THE
AREA. THIS COULD CREATE RATHER CRITICAL FIRE CONDITIONS MONDAY AS
RELATIVE HUMIDITY DROPS BELOW 20 PERCENT.
THROUGH THE REMAINDER OF THE WORK WEEK...UPPER LOW SLOWLY WORKS
OFF TO THE EAST KEEPING NORTH/NORTHWESTERLY FLOW OVER OUR AREA.
WITH THE EXCEPTION OF ISOLATED SHOWERS EARLY THIS WEEK...DRY
WEATHER IS EXPECTED. TEMPERATURES WILL REMAIN A BIT BELOW
AVERAGE WITH READINGS IN THE 50S FOR HIGHS AND 20S/30S FOR LOWS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 638 PM CDT SAT APR 18 2015
A COLD FRONT FROM NORTH CENTRAL INTO WESTERN NORTH DAKOTA EARLY
THIS EVENING WILL MOVE ACROSS THE CENTRAL THIS EVENING AND MERGE
WITH A LOW DEVELOPING ACROSS EASTERN SOUTH DAKOTA TONIGHT.
SCATTERED RAIN SHOWERS ARE EXPECTED TO MOVE FROM WESTERN INTO
CENTRAL NORTH DAKOTA THIS EVENING...AND BECOME MORE WIDESPREAD AS
THEY MERGE WITH SHOWERS MOVING IN FROM THE SOUTH. EMBEDDED MVFR
CONDITIONS POSSIBLE IN RAIN.
&&
.FIRE WEATHER...
ISSUED AT 315 PM CDT SAT APR 18 2015
CRITICAL FIRE WEATHER CONDITIONS MAY BE POSSIBLE ON MONDAY...AND
THIS WILL NEED TO BE MONITORED. WHILE TEMPERATURES WILL ONLY BE IN
THE 50S...MINIMUM RELATIVE HUMIDITY LEVELS OF 15 TO 20 PERCENT AND
NORTHWEST WINDS OF 25 TO 35 MPH ARE POSSIBLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AYD
LONG TERM...AJ
AVIATION...TWH
FIRE WEATHER...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1253 AM CDT FRI APR 17 2015
.UPDATE...
UPDATE ISSUED AT 1253 AM CDT FRI APR 17 2015
UPDATED FORECAST WITH THE CURRENT OBS. LOW TEMPERATURES HAVE BEEN
DUMPED DOWN TO REFLECT THE CURRENT OBS AND DEWPOINTS.
UPDATE
ISSUED AT 1001 PM CDT THU APR 16 2015
AS DISCUSSED BELOW...DRY AIR/LIGHT WINDS/A CLEAR SKY RESULTING IN
TEMPERATURES QUICKLY FALLING THROUGH THE 40S. ALREADY SOME MID 30S
REPORTED AT HETTINGER AND TIOGA. WILL BUMP OVERNIGHT LOWS DOWN A
BIT MORE. PRODUCTS OUT IN THE NEXT 15-20 MINUTES.
UPDATE
ISSUED AT 639 PM CDT THU APR 16 2015
VERY DRY AIR FILTERING IN FROM THE NORTHWEST. LOWERED DEW POINTS A
BIT CLOSER TO THE HRRR WHICH SEEMS TO BEST CAPTURE THIS...TEENS TO
LOW 20S WEST AND CENTRAL...30S OVER MY FAR SOUTHEAST. WITH A CLEAR
SKY AND WINDS TAPERING OFF...A GOOD SETUP FOR RADIATIONAL COOLING
TONIGHT SO DID TWEAK TEMPS DOWN A TAD...LOW 30S OVER MY WEST. MAY
NEED TO GO LOWER AND WILL MONITOR TRENDS OVER THE NEXT FEW HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 256 PM CDT THU APR 16 2015
H500 DEFORMATION ZONE BETWEEN THE CLOSED LOW ALOFT OVER THE FOUR
CORNERS AREA AND THE WESTERLY FLOW OVER SOUTHERN CANADA FORMING A
REGION OF SINKING/DRYING AIR OVER NORTHERN NORTH DAKOTA. AT THE
SURFACE HIGH PRESSURE OVER WYOMING AND MONTANA WILL MOVE EAST.
THESE FEATURES WILL CLEAR SKIES ACROSS THE REGION TONIGHT AND
FRIDAY. USED THE RAWBLEND GUIDANCE WHICH HAS PERFORMED WELL PAST
FEW NIGHT FOR MINIMUM TEMPERATURES. FOR HIGHS FRIDAY FOLLOWED THE
EUROPEAN BIAS CORRECTED GUIDANCE. THIS GAVE HIGHS CLOSE TO 70.
SEVERAL FACTORS COMBINING TO KEEP RELATIVE HUMIDITY LOW THROUGH THE
SHORT TERM. VEGETATION STILL LARGELY DORMANT AND LACK OF SOIL
MOISTURE KEEPS EVAPOTRANSPIRATION LOW. SO MAX RELATIVE HUMIDITY
TONIGHT SHOULD BE WELL BELOW SATURATION AND IN THE 70S...WITH MIN
RELATIVE HUMIDITY FRIDAY AROUND 20 PERCENT. WHAT WILL KEEP FIRE
WEATHER CONCERNS LOW WILL BE THE LACK OF WIND. EXPECTING
NORTHERLY WINDS AROUND 10 MPH FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 256 PM CDT THU APR 16 2015
A COOL AND DREARY PATTERN THROUGH THE EXTENDED.
WIDESPREAD RAINFALL IS LIKELY SATURDAY INTO SUNDAY. OCCASIONAL
SPRINKLES ARE POSSIBLE TROUGH TUESDAY.
THE UPPER LEVEL LOW CURRENTLY SPINNING AROUND THE FOUR CORNERS
REGION OF THE SOUTHWEST CONUS WILL SLOWLY LIFT NORTHEAST OVER THE
NEXT COUPLE OF DAYS. THIS LOW WILL TRANSPORT MOISTURE NORTHWARD.
MOISTURE WILL COMBINE WITH AMPLE LIFT SUPPLIED BY ANOTHER
LOW...AND COLD FRONT...PROPAGATING ACROSS SOUTHERN CANADA THIS
WEEKEND. WIDESPREAD RAINFALL IS LIKELY ACROSS PORTIONS OF THE
DAKOTAS AND MINNESOTA. AT THIS TIME THE 12 UTC GFS/ECMWF/SREF
INDICATE THE HEAVIEST RAINFALL (HALF INCH OR GREATER) WILL FALL
ACROSS SOUTHEAST NORTH DAKOTA AND WESTERN MINNESOTA. AS THE TWO
LOWS PROPAGATE EASTWARD AND COMBINE THEY SHOULD CREATE A RATHER
DEEP AND SLOW MOVING TROUGH ACROSS THE GREAT LAKES BY EARLY NEXT
WEEK. IT APPEARS THIS WILL LEAD TO A RATHER STAGNANT PATTERN OVER
THE NEXT WEEK WITH GENERALLY COOL AND CLOUDY CONDITIONS FOR MOST
OF NORTH DAKOTA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1253 AM CDT FRI APR 17 2015
VFR CONDITIONS WITH MOSTLY CLEAR SKIES AND LIGHT/VARIABLE WINDS
ARE EXPECTED THROUGH THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AC
SHORT TERM...WAA
LONG TERM...AJ
AVIATION...AC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1206 AM CDT FRI APR 17 2015
.UPDATE...
ISSUED AT 1206 AM CDT FRI APR 17 2015
UPDATED FORECAST WITH THE CURRENT OBS...NO MAJOR ADJUSTMENTS
NEEDED. WILL CONTINUE TO MONITOR LOW TEMPERATURES.
UPDATE
ISSUED AT 1001 PM CDT THU APR 16 2015
AS DISCUSSED BELOW...DRY AIR/LIGHT WINDS/A CLEAR SKY RESULTING IN
TEMPERATURES QUICKLY FALLING THROUGH THE 40S. ALREADY SOME MID 30S
REPORTED AT HETTINGER AND TIOGA. WILL BUMP OVERNIGHT LOWS DOWN A
BIT MORE. PRODUCTS OUT IN THE NEXT 15-20 MINUTES.
UPDATE
ISSUED AT 639 PM CDT THU APR 16 2015
VERY DRY AIR FILTERING IN FROM THE NORTHWEST. LOWERED DEW POINTS A
BIT CLOSER TO THE HRRR WHICH SEEMS TO BEST CAPTURE THIS...TEENS TO
LOW 20S WEST AND CENTRAL...30S OVER MY FAR SOUTHEAST. WITH A CLEAR
SKY AND WINDS TAPERING OFF...A GOOD SETUP FOR RADIATIONAL COOLING
TONIGHT SO DID TWEAK TEMPS DOWN A TAD...LOW 30S OVER MY WEST. MAY
NEED TO GO LOWER AND WILL MONITOR TRENDS OVER THE NEXT FEW HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 256 PM CDT THU APR 16 2015
H500 DEFORMATION ZONE BETWEEN THE CLOSED LOW ALOFT OVER THE FOUR
CORNERS AREA AND THE WESTERLY FLOW OVER SOUTHERN CANADA FORMING A
REGION OF SINKING/DRYING AIR OVER NORTHERN NORTH DAKOTA. AT THE
SURFACE HIGH PRESSURE OVER WYOMING AND MONTANA WILL MOVE EAST.
THESE FEATURES WILL CLEAR SKIES ACROSS THE REGION TONIGHT AND
FRIDAY. USED THE RAWBLEND GUIDANCE WHICH HAS PERFORMED WELL PAST
FEW NIGHT FOR MINIMUM TEMPERATURES. FOR HIGHS FRIDAY FOLLOWED THE
EUROPEAN BIAS CORRECTED GUIDANCE. THIS GAVE HIGHS CLOSE TO 70.
SEVERAL FACTORS COMBINING TO KEEP RELATIVE HUMIDITY LOW THROUGH THE
SHORT TERM. VEGETATION STILL LARGELY DORMANT AND LACK OF SOIL
MOISTURE KEEPS EVAPOTRANSPIRATION LOW. SO MAX RELATIVE HUMIDITY
TONIGHT SHOULD BE WELL BELOW SATURATION AND IN THE 70S...WITH MIN
RELATIVE HUMIDITY FRIDAY AROUND 20 PERCENT. WHAT WILL KEEP FIRE
WEATHER CONCERNS LOW WILL BE THE LACK OF WIND. EXPECTING
NORTHERLY WINDS AROUND 10 MPH FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 256 PM CDT THU APR 16 2015
A COOL AND DREARY PATTERN THROUGH THE EXTENDED.
WIDESPREAD RAINFALL IS LIKELY SATURDAY INTO SUNDAY. OCCASIONAL
SPRINKLES ARE POSSIBLE TROUGH TUESDAY.
THE UPPER LEVEL LOW CURRENTLY SPINNING AROUND THE FOUR CORNERS
REGION OF THE SOUTHWEST CONUS WILL SLOWLY LIFT NORTHEAST OVER THE
NEXT COUPLE OF DAYS. THIS LOW WILL TRANSPORT MOISTURE NORTHWARD.
MOISTURE WILL COMBINE WITH AMPLE LIFT SUPPLIED BY ANOTHER
LOW...AND COLD FRONT...PROPAGATING ACROSS SOUTHERN CANADA THIS
WEEKEND. WIDESPREAD RAINFALL IS LIKELY ACROSS PORTIONS OF THE
DAKOTAS AND MINNESOTA. AT THIS TIME THE 12 UTC GFS/ECMWF/SREF
INDICATE THE HEAVIEST RAINFALL (HALF INCH OR GREATER) WILL FALL
ACROSS SOUTHEAST NORTH DAKOTA AND WESTERN MINNESOTA. AS THE TWO
LOWS PROPAGATE EASTWARD AND COMBINE THEY SHOULD CREATE A RATHER
DEEP AND SLOW MOVING TROUGH ACROSS THE GREAT LAKES BY EARLY NEXT
WEEK. IT APPEARS THIS WILL LEAD TO A RATHER STAGNANT PATTERN OVER
THE NEXT WEEK WITH GENERALLY COOL AND CLOUDY CONDITIONS FOR MOST
OF NORTH DAKOTA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 639 PM CDT THU APR 16 2015
A FEW HIGH CLOUDS ACROSS THE NORTH MOVING THROUGH
TONIGHT...OTHERWISE A CLEAR SKY AND VFR CONDITIONS THROUGH THE 00Z
PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AC
SHORT TERM...WAA
LONG TERM...AJ
AVIATION...NH
AREA FORECAST DISCUSSION
NWS TULSA OK
627 PM CDT SAT APR 18 2015
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
MAINLY VFR CONDITIONS ACROSS THE AREA THIS EVENING WITH
THUNDERSTORMS DEVELOPING TO THE WEST OF THE AREA. WENT
WITH A TEMPO FOR THUNDER AT THE EASTERN OKLAHOMA TAF SITES
AT 04Z. THIS IS IN LINE WITH WHAT THE LATEST HRRR IS PROJECTING.
FOG WILL BE A CONCERN LATE TONIGHT AT THE NORTHWEST ARKSANS
SITES...COULD SEE IFR CONDITIONS BEFORE IMPROVING MID-MORNING
SUNDAY.
&&
.PREV DISCUSSION... /ISSUED 405 PM CDT SAT APR 18 2015/
DISCUSSION...
AN UPPER LEVEL LOW CONTINUES TO RESIDE THIS AFTERNOON OVER
SOUTHERN COLORADO AND NORTHERN NEW MEXICO PER LATEST WATER VAPOR
IMAGERY. OUT AHEAD OF THE UPPER LOW A DRYLINE HAS SET UP OVER FAR
WESTERN OKLAHOMA INTO WESTERN TEXAS. SCATTERED STRONG/SEVERE
CONVECTION HAS BEGUN TO INITIATE DURING THE PAST COUPLE OF HOURS
ALONG AND NEAR THIS DRYLINE...MOVING TO THE NORTH. TO THE EAST
ACROSS EASTERN OKLAHOMA AND NORTHWEST ARKANSAS...THE PRECIP FROM
THIS MORNING/EARLY AFTERNOON HAS SHIFTED OUT OF THE CWA WITH
PARTLY TO MOSTLY CLOUDY SKIES.
THIS EVENING AND OVERNIGHT TONIGHT...THE UPPER LOW OUT WEST IS
EXPECTED TO FINALLY PUSH OUT INTO WESTERN KANSAS AND BECOME MORE
OF AN OPEN WAVE COMPARED TO THE CLOSED OFF LOW THAT IT HAS BEEN.
AS THE LOW SHIFTS EASTWARD...THE SCATTERED CONVECTION SHOULD MAKE
ITS WAY TOWARD AND INTO PORTIONS OF THE CWA TONIGHT. THE GREATER
INSTABILITY WILL BE LOCATED CLOSER TO THE DRYLINE THIS
AFTERNOON/EVENING WHICH SHOULD AID IN CONVECTION WEAKENING AS IT
PUSHES INTO THE CWA OVERNIGHT. HOWEVER...ENOUGH SHEAR AND COLD
TEMPS ALOFT WILL ALLOW FOR A LIMITED SEVERE POTENTIAL WITH LARGE
HAIL AND STRONG WINDS BEGIN THE MAIN THREATS ACROSS THE CWA THIS
EVENING AND OVERNIGHT. CLOUDY CONDITIONS ALONG WITH DEWPOINTS
HOLDING IN THE UPPER 50/LOW 60S SHOULD KEEP LOW TEMPS SUNDAY
MORNING CLOSE TO THIS MORNING LOWS.
THE UPPER LOW IS FORECAST TO MOVE ACROSS THE REGION DURING THE DAY
SUNDAY...PUSHING A COLD FRONT INTO EASTERN OKLAHOMA SUNDAY
AFTERNOON AND THROUGH NORTHWEST ARKANSAS SUNDAY EVENING. AHEAD OF
THE COLD FRONT...THUNDERSTORM CHANCES WILL CONTINUE OVER THE CWA
WITH A LIMITED SEVERE POTENTIAL OVER MUCH OF THE REGION AS THE CAP
LOOKS TO BE WEAK. AN ELEVATED SEVERE POTENTIAL LOOKS POSSIBLE OVER
SOUTHEAST OKLAHOMA INTO WEST CENTRAL ARKANSAS AND EXTENDING
EASTWARD WHERE THE WARMER TEMPS AND BETTER INSTABILITY LOOKS TO BE
LOCATED. LARGE HAIL AND DAMAGING WINDS AGAIN LOOK TO BE THE MAIN
HAZARDS WITH ANY CONVECTION AHEAD OF THE FRONT. BEHIND THE
FRONT...GUSTY NORTHERLY WINDS IN THE 20 TO 30 MPH RANGE WILL BE
POSSIBLE.
LATEST MODEL SOLUTIONS INDICATE THE COLD FRONT EXITING THE CWA
SUNDAY EVENING AS THE UPPER LOW GETS ABSORBED INTO A SECOND LOW
PRESSURE SYSTEM DROPPING OUT OF CENTRAL CANADA AND INTO THE GREAT
LAKES REGION. THIS WILL AID IN TEMPS FALLING INTO THE 40S FOR MOST
LOCATIONS BY MONDAY MORNING AND COOL HIGH TEMPS MONDAY AFTERNOON.
DRIER AIR OVER THE CWA WILL HELP TO DELAY THE NEXT PRECIP CHANCES
INTO TUESDAY AS A PIECE OF ENERGY DROPS DOWN THROUGH THE PLAINS ON
THE BACKSIDE OF THE SLOW MOVING UPPER LOW OVER THE GREAT LAKES.
IN THE EXTENDED FORECAST...A FRONTAL BOUNDARY LOOKS TO MOVE INTO
THE CWA THURSDAY AHEAD OF ANOTHER SHORTWAVE MOVING INTO THE
SOUTHERN PLAINS WITHIN THE ZONAL FLOW ALOFT. THIS BOUNDARY SHOULD
BECOME THE FOCUS FOR THUNDERSTORM DEVELOPMENT WEDNESDAY INTO THE
WEEKEND BEFORE THE SHORTWAVE AND THE FRONT PUSHES EAST OF THE CWA.
INCREASING MOISTURE...AN UPPER LEVEL JET STREAK OF 100-130KT
PARALLEL TO THE NEARLY STATIONARY FRONTAL BOUNDARY AND INSTABILITY
OVER THE REGION WILL ALLOW FOR THE POTENTIAL FOR SEVERE WEATHER TO
BE POSSIBLE OVER THE REGION. TEMPS DURING THIS TIME FRAME LOOK TO BE
COOLER ON THE NORTHERN SIDE OF THE FRONT AND WARMER TO THE SOUTH.
LATEST INDICATIONS ARE THAT TEMPS COULD BE COOLER THAN WHAT HAS
BEEN FORECAST WHICH COULD LIMITED THE OVERALL SEVERE POTENTIAL.
THUS...WILL CONTINUE TO MONITOR LATEST DATA AS THIS SYSTEM SETS UP
OVER THE NEXT SEVERAL DAYS.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...10
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1030 AM MDT FRI APR 17 2015
.UPDATE...
ISSUED AT 1022 AM MDT FRI APR 17 2015
UPPER LOW CONTINUES TO CHURN OVER THE FOUR CORNERS REGION WITH
BANDS OF LIGHT RAIN MOVING NORTHWEST THROUGH NEBRASKA AND JUST
EDGING INTO FAR SOUTHWEST SOUTH DAKOTA. EXPECT THESE BANDS OF
LIGHT RAIN TO CONTINUE TO MOVE INTO FAR SOUTHERN PORTIONS OF SOUTH
DAKOTA WITH RAIN EVENTUALLY MOVING NORTH TO THE INTERSTATE 90
CORRIDOR BY LATE THIS AFTERNOON.
MADE MINOR ADJUSTMENTS TO THE PROGRESSION OF RAIN NORTHWARD -
SLOWING IT DOWN...AND REMOVED MENTION OF ISOLATED THUNDER THROUGH
LATE AFTERNOON...AS IT LOOKS LIKE LAPSE RATES AND AVAILABLE ENERGY
ARE MEAGER AT BEST. BETTER CHANCES FOR THUNDER ACROSS NORTHEAST
WYOMING AND SOUTHERN SOUTH DAKOTA SATURDAY AFTERNOON.
REMAINDER OF FORECAST IN GOOD SHAPE. UPDATES ARE OUT.
&&
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 352 AM MDT FRI APR 17 2015
CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER THE OKLAHOMA
PANHANDLE AREA RIGHT NOW...WITH WEAK HIGH PRESSURE OVER EASTERN MT
INTO WESTERN ND. UPPER LEVEL ANALYSIS SHOWS LARGE LOW PRESSURE
SYSTEM CENTERED OVER THE FOUR CORNERS AREA...WITH STRONG JET
WRAPPING AROUND THE SOUTHERN AND EASTERN SIDES OF THE LOW. CLOUD
SHIELD TO THE NORTH AND EAST OF THE SYSTEM IS PUSHING NORTHWARD
INTO SOUTHERN PARTS OF THE CWA...BUT DRYING UP AS IT MOVES INTO
VERY DRY AIRMASS OVER NORTHERN PORTIONS OF THE NORTHERN PLAINS
RIGHT NOW. REGIONAL RADARS SHOWING SHOWERS MOVING WEST-NORTHWEST
ACROSS MUCH OF WESTERN NEB INTO SOUTHEAST WY...WITH DRY CONDITIONS
PREVAILING ACROSS OUR CWA AT THE MOMENT. TEMPS CURRENTLY RANGE
FROM THE LOW TO MID 30S ACROSS PORTIONS OF NORTHEAST WY...THE
BLACK HILLS...AND FAR NORTHWEST SD...TO THE UPPER 40S ACROSS SOUTH
CENTRAL SD. WINDS ARE VARIABLE AT LESS THAN 10 MPH.
THE SYSTEM OVER THE FOUR CORNERS AREA EARLY THIS MORNING WILL MOVE
SLOWLY NORTHEASTWARD ACROSS SOUTHERN AND EASTERN CO OVER THE NEXT
COUPLE OF DAYS AND THEN ACCELERATE EASTWARD ACROSS THE CENTRAL
PLAINS SATURDAY NIGHT INTO SUNDAY. THE EXACT TRACK AND TIMING OF THE
SYSTEM IS STILL UNCERTAIN AT THIS POINT AND WILL ULTIMATELY HELP
DETERMINE HOW MUCH PCPN WE GET ACROSS THE AREA...ESPECIALLY NORTHERN
AND WESTERN PORTIONS OF THE CWA...WHERE AMOUNTS OF VERY LITTLE TO A
HALF INCH OR MORE ARE POSSIBLE DEPENDING ON THE TRACK. ALL THE 00Z
SHORT RANGE MODELS SHOW MOST OR ALL OF THE CWA RECEIVING AT LEAST A
LITTLE BIT OF RAINFALL...WITH THE HIGHEST AMOUNTS GENERALLY OVER FAR
SOUTHWEST INTO SOUTH CENTRAL SD. THE 00Z GFS SHOWS THE HEAVIEST PCPN
FURTHER EAST TOWARD CENTRAL SD...WHILE THE OTHER MODELS GENERALLY
HAVE IT OVER FAR SOUTHWEST/SOUTHERN SD. WILL LEAN THE FORECAST MORE
TOWARD THE CONSENSUS AT THIS POINT AND KEEP HEAVIER PCPN AMOUNTS
OVER FAR SOUTHERN SD. FORECAST CONFIDENCE IS HIGHEST RIGHT NOW ON
SOUTHERN PORTIONS OF THE CWA RECEIVING THE MOST RAINFALL...AS WELL
AS THE BEST CHANCES FOR RAINFALL ACROSS THE CWA BEING LATER TONIGHT
INTO SATURDAY EVENING. PROJECTED RAINFALL AMOUNTS ACROSS THE CWA
WILL MOSTLY BE IN THE 0.25 TO 0.75 INCH RANGE...WITH LESSER AMOUNTS
LIKELY OVER FAR NORTHWESTERN PORTIONS OF THE CWA AND POSSIBLY AN
INCH OR MORE OVER FAR SOUTHWEST INTO SOUTH CENTRAL SD.
HOWEVER...WOULD TEND TO LEAN MORE TOWARD THE LIGHTER AMOUNTS FOR
MOST AREAS AS HAS BEEN THE CASE FOR SYSTEMS OF LATE.
FOR TODAY...SKIES WILL STAY MOSTLY CLOUDY ACROSS FAR SOUTHERN
PORTIONS OF THE CWA...WITH CLOUDS GRADUALLY INCREASING TO THE NORTH.
WITH MORE SUNSHINE...TEMPS THIS AFTERNOON WILL BE HIGHEST OVER FAR
NORTHERN AND EASTERN PORTIONS OF THE CWA...WITH HIGHS RANGING FROM
THE 50S OVER THE BLACK HILLS AND FAR SOUTHWEST SD TO THE MID TO
UPPER 60S OVER FAR NORTHWEST INTO CENTRAL SD. WINDS WILL BECOME EAST
TO NORTHEAST IN MOST AREAS BY THE AFTERNOON. CHANCES FOR SHOWERS
WILL MAINLY BE CONFINED TO SOUTHERN SD TODAY...WITH THE BEST CHANCES
IN THE AFTERNOON. CAN NOT RULE OUT A THUNDERSTORM OR TWO ACROSS
SOUTHERN AREAS AS WELL THIS AFTERNOON.
AS THE UPPER LOW MOVES ACROSS CO TONIGHT AND SATURDAY...LOW LEVEL
MOISTURE AND UPPER LEVEL ENERGY WILL EXPAND NORTHWARD INTO THE
NORTHERN PLAINS...ESPECIALLY LATER TONIGHT AND SATURDAY. SHOWERS AND
ISOLATED THUNDERSTORMS CAN BE EXPECTED ACROSS THE AREA. THE MOST
WIDESPREAD COVERAGE OF SHOWERS SHOULD BE ON SATURDAY...SO WILL GO
WITH LIKELY POPS ACROSS MOST OF THE CWA. WITH THE LOW STAYING FAR
ENOUGH SOUTH OF THE CWA...TEMPS WILL STAY WARM ENOUGH FOR MOSTLY
RAIN ACROSS EVEN THE BLACK HILLS...BUT COULD SEE A MIX OVER THE
HIGHEST ELEVATIONS...MAINLY LATE TONIGHT/EARLY SATURDAY AND THEN
SATURDAY NIGHT WHEN THE SYSTEM EXITS. A COLD FRONT WILL TRACK ACROSS
THE CWA LATE SATURDAY AND SATURDAY NIGHT...HELPING TO PUSH THE
SYSTEM OUT OF THE REGION...BUT WILL BRING GUSTY WINDS ACROSS THE
AREA INTO SUNDAY.
.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 352 AM MDT FRI APR 17 2015
BLOCKED FLOW TO DEVELOP OVER THE WESTERN ATLANTIC AND
EASTERN NOAM...WHICH WILL SET THE STAGE FOR WESTERN NOAM RIDING AND
POTENTIAL REX TYPE BLOCKING OVER THE WESTERN CONUS. THIS WILL
SUPPORT A LOW CONFIDENCE FLOW REGIME AS FORECAST MODELS WILL
CONTINUALLY ADJUST TO THE LATEST OBS GIVEN TYPICAL POOR MODEL
PERFORMANCE IN THESE PATTERNS. GENERALLY DRY CONDS CAN BE EXPECTED
GIVEN THE REGION/S PROXY TO THE EASTERN NOAM UPPER TROUGH. A WEAK
SIGNAL FOR PRECIP DOES REMAIN TOWARD THE END OF THE PERIOD WHEN
FORECAST MODELS TRY TO ADVECT A WANDERING UPPER TROUGH EAST.
HOWEVER...AS ALREADY STATED...LOW CONFIDENCE PER FLOW DETAILS LENDS
ONLY A 20 POP AT BEST...WITH DRY THE LIKELY SCENARIO GIVEN THE
PATTERN. GIVEN STRONG INFLUENCE EXPECTED OF THE EVENTUAL EASTERN
CONUS UPPER LOW...EXPECT TEMPS TO BE NEAR OR SLIGHTLY BELOW SEASONAL
NORMS IN THE MAJORITY OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 538 AM MDT FRI APR 17 2015
VFR CONDS WILL PREVAIL MOST PLACES IN THE PERIOD. A SLOW MOVING
UPPER LOW WILL SLIDE NE AND BRING MVFR CONDS IN RAIN TO MAINLY
EXTREME SW SD TODAY. MVFR CONDS WILL SPREAD NORTH
TONIGHT...AFFECTING THE RAP TERMINAL BY LATE IN THE PERIOD...WITH
SCT IFR CIGS POSSIBLE IN THE BLACK HILLS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...15
SHORT TERM...26
LONG TERM...JC
AVIATION...JC
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
542 AM MDT FRI APR 17 2015
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 352 AM MDT FRI APR 17 2015
CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER THE OKLAHOMA
PANHANDLE AREA RIGHT NOW...WITH WEAK HIGH PRESSURE OVER EASTERN MT
INTO WESTERN ND. UPPER LEVEL ANALYSIS SHOWS LARGE LOW PRESSURE
SYSTEM CENTERED OVER THE FOUR CORNERS AREA...WITH STRONG JET
WRAPPING AROUND THE SOUTHERN AND EASTERN SIDES OF THE LOW. CLOUD
SHIELD TO THE NORTH AND EAST OF THE SYSTEM IS PUSHING NORTHWARD
INTO SOUTHERN PARTS OF THE CWA...BUT DRYING UP AS IT MOVES INTO
VERY DRY AIRMASS OVER NORTHERN PORTIONS OF THE NORTHERN PLAINS
RIGHT NOW. REGIONAL RADARS SHOWING SHOWERS MOVING WEST-NORTHWEST
ACROSS MUCH OF WESTERN NEB INTO SOUTHEAST WY...WITH DRY CONDITIONS
PREVAILING ACROSS OUR CWA AT THE MOMENT. TEMPS CURRENTLY RANGE
FROM THE LOW TO MID 30S ACROSS PORTIONS OF NORTHEAST WY...THE
BLACK HILLS...AND FAR NORTHWEST SD...TO THE UPPER 40S ACROSS SOUTH
CENTRAL SD. WINDS ARE VARIABLE AT LESS THAN 10 MPH.
THE SYSTEM OVER THE FOUR CORNERS AREA EARLY THIS MORNING WILL MOVE
SLOWLY NORTHEASTWARD ACROSS SOUTHERN AND EASTERN CO OVER THE NEXT
COUPLE OF DAYS AND THEN ACCELERATE EASTWARD ACROSS THE CENTRAL
PLAINS SATURDAY NIGHT INTO SUNDAY. THE EXACT TRACK AND TIMING OF THE
SYSTEM IS STILL UNCERTAIN AT THIS POINT AND WILL ULTIMATELY HELP
DETERMINE HOW MUCH PCPN WE GET ACROSS THE AREA...ESPECIALLY NORTHERN
AND WESTERN PORTIONS OF THE CWA...WHERE AMOUNTS OF VERY LITTLE TO A
HALF INCH OR MORE ARE POSSIBLE DEPENDING ON THE TRACK. ALL THE 00Z
SHORT RANGE MODELS SHOW MOST OR ALL OF THE CWA RECEIVING AT LEAST A
LITTLE BIT OF RAINFALL...WITH THE HIGHEST AMOUNTS GENERALLY OVER FAR
SOUTHWEST INTO SOUTH CENTRAL SD. THE 00Z GFS SHOWS THE HEAVIEST PCPN
FURTHER EAST TOWARD CENTRAL SD...WHILE THE OTHER MODELS GENERALLY
HAVE IT OVER FAR SOUTHWEST/SOUTHERN SD. WILL LEAN THE FORECAST MORE
TOWARD THE CONSENSUS AT THIS POINT AND KEEP HEAVIER PCPN AMOUNTS
OVER FAR SOUTHERN SD. FORECAST CONFIDENCE IS HIGHEST RIGHT NOW ON
SOUTHERN PORTIONS OF THE CWA RECEIVING THE MOST RAINFALL...AS WELL
AS THE BEST CHANCES FOR RAINFALL ACROSS THE CWA BEING LATER TONIGHT
INTO SATURDAY EVENING. PROJECTED RAINFALL AMOUNTS ACROSS THE CWA
WILL MOSTLY BE IN THE 0.25 TO 0.75 INCH RANGE...WITH LESSER AMOUNTS
LIKELY OVER FAR NORTHWESTERN PORTIONS OF THE CWA AND POSSIBLY AN
INCH OR MORE OVER FAR SOUTHWEST INTO SOUTH CENTRAL SD.
HOWEVER...WOULD TEND TO LEAN MORE TOWARD THE LIGHTER AMOUNTS FOR
MOST AREAS AS HAS BEEN THE CASE FOR SYSTEMS OF LATE.
FOR TODAY...SKIES WILL STAY MOSTLY CLOUDY ACROSS FAR SOUTHERN
PORTIONS OF THE CWA...WITH CLOUDS GRADUALLY INCREASING TO THE NORTH.
WITH MORE SUNSHINE...TEMPS THIS AFTERNOON WILL BE HIGHEST OVER FAR
NORTHERN AND EASTERN PORTIONS OF THE CWA...WITH HIGHS RANGING FROM
THE 50S OVER THE BLACK HILLS AND FAR SOUTHWEST SD TO THE MID TO
UPPER 60S OVER FAR NORTHWEST INTO CENTRAL SD. WINDS WILL BECOME EAST
TO NORTHEAST IN MOST AREAS BY THE AFTERNOON. CHANCES FOR SHOWERS
WILL MAINLY BE CONFINED TO SOUTHERN SD TODAY...WITH THE BEST CHANCES
IN THE AFTERNOON. CAN NOT RULE OUT A THUNDERSTORM OR TWO ACROSS
SOUTHERN AREAS AS WELL THIS AFTERNOON.
AS THE UPPER LOW MOVES ACROSS CO TONIGHT AND SATURDAY...LOW LEVEL
MOISTURE AND UPPER LEVEL ENERGY WILL EXPAND NORTHWARD INTO THE
NORTHERN PLAINS...ESPECIALLY LATER TONIGHT AND SATURDAY. SHOWERS AND
ISOLATED THUNDERSTORMS CAN BE EXPECTED ACROSS THE AREA. THE MOST
WIDESPREAD COVERAGE OF SHOWERS SHOULD BE ON SATURDAY...SO WILL GO
WITH LIKELY POPS ACROSS MOST OF THE CWA. WITH THE LOW STAYING FAR
ENOUGH SOUTH OF THE CWA...TEMPS WILL STAY WARM ENOUGH FOR MOSTLY
RAIN ACROSS EVEN THE BLACK HILLS...BUT COULD SEE A MIX OVER THE
HIGHEST ELEVATIONS...MAINLY LATE TONIGHT/EARLY SATURDAY AND THEN
SATURDAY NIGHT WHEN THE SYSTEM EXITS. A COLD FRONT WILL TRACK ACROSS
THE CWA LATE SATURDAY AND SATURDAY NIGHT...HELPING TO PUSH THE
SYSTEM OUT OF THE REGION...BUT WILL BRING GUSTY WINDS ACROSS THE
AREA INTO SUNDAY.
.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 352 AM MDT FRI APR 17 2015
BLOCKED FLOW TO DEVELOP OVER THE WESTERN ATLANTIC AND
EASTERN NOAM...WHICH WILL SET THE STAGE FOR WESTERN NOAM RIDING AND
POTENTIAL REX TYPE BLOCKING OVER THE WESTERN CONUS. THIS WILL
SUPPORT A LOW CONFIDENCE FLOW REGIME AS FORECAST MODELS WILL
CONTINUALLY ADJUST TO THE LATEST OBS GIVEN TYPICAL POOR MODEL
PERFORMANCE IN THESE PATTERNS. GENERALLY DRY CONDS CAN BE EXPECTED
GIVEN THE REGION/S PROXY TO THE EASTERN NOAM UPPER TROUGH. A WEAK
SIGNAL FOR PRECIP DOES REMAIN TOWARD THE END OF THE PERIOD WHEN
FORECAST MODELS TRY TO ADVECT A WANDERING UPPER TROUGH EAST.
HOWEVER...AS ALREADY STATED...LOW CONFIDENCE PER FLOW DETAILS LENDS
ONLY A 20 POP AT BEST...WITH DRY THE LIKELY SCENARIO GIVEN THE
PATTERN. GIVEN STRONG INFLUENCE EXPECTED OF THE EVENTUAL EASTERN
CONUS UPPER LOW...EXPECT TEMPS TO BE NEAR OR SLIGHTLY BELOW SEASONAL
NORMS IN THE MAJORITY OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 538 AM MDT FRI APR 17 2015
VFR CONDS WILL PREVAIL MOST PLACES IN THE PERIOD. A SLOW MOVING
UPPER LOW WILL SLIDE NE AND BRING MVFR CONDS IN RAIN TO MAINLY
EXTREME SW SD TODAY. MVFR CONDS WILL SPREAD NORTH
TONIGHT...AFFECTING THE RAP TERMINAL BY LATE IN THE PERIOD...WITH
SCT IFR CIGS POSSIBLE IN THE BLACK HILLS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...26
LONG TERM...JC
AVIATION...JC
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1006 PM CDT SAT APR 18 2015
.UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO INCREASE SHWR/TSTM CHANCES
FROM SW TO NE REST OF EVENING AND OVERNIGHT. TWEAKED HRLY TEMP...DEWPOINT...
SKY...AND WIND SPEED/DIRECTION GRIDS ALSO. REMAINDER OF FORECAST
REMAINS ON TRACK.
&&
.PREV DISCUSSION.../ISSUED 633 PM CDT SAT APR 18 2015/
UPDATE...FOR AVIATION.
AVIATION...
00Z TAFS...BNA/CKV/CSV...A LOW PRESSURE SYSTEM AND WARM FRONT WILL
LIFT INTO MID TN OVERNIGHT BRINGING WIDESPREAD SHOWERS WITH
EMBEDDED TSRA. LOOK FOR MVFR CIGS/VSBYS TO DEVELOP AROUND
06Z...DROPPING TO IFR AND SOME LIFR WITH POCKETS OF +SHRA BY 11Z.
THE MAIN BAND OF MOISTURE WILL LIFT NORTH OF THE ARA BY 18Z...WITH
IMPROVEMENT ON SUNDAY AFTERNOON. ANOTHER SYSTEM WILL APPROACH
SUNDAY EVENING WITH SCATTERED TSRA...SOME POSSIBLY SEVERE.
13
PREV DISCUSSION... /ISSUED 530 PM CDT SAT APR 18 2015/
UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CURRENT REGIONAL
SFC OBS...SATELLITE...AND MOSAIC RADAR TRENDS ALONG WITH THE LATEST IN
SHORT RANGE MODEL CONSENSUS...THUS MAINTAINING ISO SHWRS/TSTMS THRU AT
LEAST THE MID EVENING HRS. BULK OF SHWR/TSTMS ACTIVITY SHOULD SPREAD FROM
THE SW TO THE NE ACROSS THE MID STATE AFTER MIDNIGHT.
PREV DISCUSSION.../ISSUED 351 PM CDT SAT APR 18 2015/
DISCUSSION...
AS AN UPPER TROUGH CENTERED OVER THE CENTRAL PLAINS MOVES EAST THIS
AFTERNOON AND OVERNIGHT IT WILL INFLUENCE SHOWERS AND THUNDERSTORMS
TO CONTINUE THEIR TREK NORTHWARD THROUGH MIDDLE TN. HRRR IS FORECASTING
SCATTERED AFTERNOON ACTIVITY TO MOVE INTO KENTUCKY AND ANOTHER
WAVE OF PRECIP TO SPREAD INTO MIDDLE TENNESSEE FROM THE SOUTH
BEFORE MIDNIGHT. PWAT VALUES WILL BE AROUND 1.5 INCHES FOR SEVERAL
HOURS OVERNIGHT TONIGHT. WITH THE GROUND ALREADY SATURATED FROM
THIS PAST WEEK`S RAINFALL...WE COULD SEE CREEKS AND STREAMS RISE
PRETTY QUICKLY DURING THE OVERNIGHT HOURS...WATCH FOR MINOR
FLOODING IN LOW LYING AREAS AND PONDING OF WATER ON ROADWAYS
OVERNIGHT. WHILE THERE MAY BE STORMS AROUND...NOT EXPECTING
ANYTHING STRONG OR SEVERE TONIGHT.
BETWEEN LATE SUNDAY MORNING AND EARLY AFTERNOON THE DEEPEST
MOISTURE WILL PUSH NORTH OF OUR AREA. LINGERING CLOUD
COVER...ESPECIALLY OVER THE NORTHEASTERN PORTION OF THE CWA MAY
INHIBIT INSTABILITY...BUT CLOUDS SHOULD BREAK UP ENOUGH DURING
THE AFTERNOON HOURS TO ALLOW FOR TEMPERATURES TO WARM INTO THE LOW
70S ALONG THE CUMBERLAND PLATEAU AND MID 70S ELSEWHERE. THIS
SHOULD BE WARM ENOUGH TO INITIATE ISOLATED TO SCATTERED STORMS
THROUGHOUT THE AFTERNOON. CURRENTLY SPC HAS THE MID-STATE IN A
SLIGHT RISK FOR SEVERE THUNDERSTORMS FOR SUNDAY AFTERNOON THROUGH
SUNDAY NIGHT. THE MAIN THREAT WITH ANY STORMS DURING THIS TIME
FRAME WILL BE DAMAGING WINDS AND HAIL. WE COULD SEE A COUPLE OF
ROUNDS OF THUNDERSTORMS OVERNIGHT SUNDAY NIGHT AHEAD OF A
SHORTWAVE AND ITS ASSOCIATED SURFACE LOW...WHICH STRENGTHEN OVER
SOUTHERN ILLINOIS AND HEAD NORTHEAST ON MONDAY.
THE FRONTAL PASSAGE ASSOCIATED WITH THE AFOREMENTIONED LOW WILL
OCCUR ON MONDAY AND WILL ALLOW FOR TEMPERATURES TO COOL INTO THE
40S OVERNIGHT MONDAY NIGHT. ALL PRECIP SHOULD PUSH EAST OF THE
TENNESSEE VALLEY TUESDAY NIGHT. A SURFACE HIGH MOVES IN ON TUESDAY
AND GIVES US A MUCH NEEDED DRY AND RELATIVELY COOL DAY WITH HIGH
TEMPERATURES IN THE MID 60S.
THE NEXT CHANCE OF PRECIP ENTERS THE FORECAST WEDNESDAY EVENING AS
A WEAK FRONT BRINGS A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH
THE AREA. COULD SEE A BREAK ON FRIDAY AS THAT MOISTURE PUSHES
SOUTH...THEN ANOTHER SURFACE LOW BRINGS ADDITIONAL THUNDERSTORM
CHANCES FRIDAY NIGHT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
633 PM CDT SAT APR 18 2015
.UPDATE...FOR AVIATION.
&&
.AVIATION...
00Z TAFS...BNA/CKV/CSV...A LOW PRESSURE SYSTEM AND WARM FRONT WILL
LIFT INTO MID TN OVERNIGHT BRINGING WIDESPREAD SHOWERS WITH
EMBEDDED TSRA. LOOK FOR MVFR CIGS/VSBYS TO DEVELOP AROUND
06Z...DROPPING TO IFR AND SOME LIFR WITH POCKETS OF +SHRA BY 11Z.
THE MAIN BAND OF MOISTURE WILL LIFT NORTH OF THE ARA BY 18Z...WITH
IMPROVEMENT ON SUNDAY AFTERNOON. ANOTHER SYSTEM WILL APPROACH
SUNDAY EVENING WITH SCATTERED TSRA...SOME POSSIBLY SEVERE.
13
&&
.PREV DISCUSSION... /ISSUED 530 PM CDT SAT APR 18 2015/
UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CURRENT REGIONAL
SFC OBS...SATELLITE...AND MOSAIC RADAR TRENDS ALONG WITH THE LATEST IN
SHORT RANGE MODEL CONSENSUS...THUS MAINTAINING ISO SHWRS/TSTMS THRU AT
LEAST THE MID EVENING HRS. BULK OF SHWR/TSTMS ACTIVITY SHOULD SPREAD FROM
THE SW TO THE NE ACROSS THE MID STATE AFTER MIDNIGHT.
PREV DISCUSSION.../ISSUED 351 PM CDT SAT APR 18 2015/
DISCUSSION...
AS AN UPPER TROUGH CENTERED OVER THE CENTRAL PLAINS MOVES EAST THIS
AFTERNOON AND OVERNIGHT IT WILL INFLUENCE SHOWERS AND THUNDERSTORMS
TO CONTINUE THEIR TREK NORTHWARD THROUGH MIDDLE TN. HRRR IS FORECASTING
SCATTERED AFTERNOON ACTIVITY TO MOVE INTO KENTUCKY AND ANOTHER
WAVE OF PRECIP TO SPREAD INTO MIDDLE TENNESSEE FROM THE SOUTH
BEFORE MIDNIGHT. PWAT VALUES WILL BE AROUND 1.5 INCHES FOR SEVERAL
HOURS OVERNIGHT TONIGHT. WITH THE GROUND ALREADY SATURATED FROM
THIS PAST WEEK`S RAINFALL...WE COULD SEE CREEKS AND STREAMS RISE
PRETTY QUICKLY DURING THE OVERNIGHT HOURS...WATCH FOR MINOR
FLOODING IN LOW LYING AREAS AND PONDING OF WATER ON ROADWAYS
OVERNIGHT. WHILE THERE MAY BE STORMS AROUND...NOT EXPECTING
ANYTHING STRONG OR SEVERE TONIGHT.
BETWEEN LATE SUNDAY MORNING AND EARLY AFTERNOON THE DEEPEST
MOISTURE WILL PUSH NORTH OF OUR AREA. LINGERING CLOUD
COVER...ESPECIALLY OVER THE NORTHEASTERN PORTION OF THE CWA MAY
INHIBIT INSTABILITY...BUT CLOUDS SHOULD BREAK UP ENOUGH DURING
THE AFTERNOON HOURS TO ALLOW FOR TEMPERATURES TO WARM INTO THE LOW
70S ALONG THE CUMBERLAND PLATEAU AND MID 70S ELSEWHERE. THIS
SHOULD BE WARM ENOUGH TO INITIATE ISOLATED TO SCATTERED STORMS
THROUGHOUT THE AFTERNOON. CURRENTLY SPC HAS THE MID-STATE IN A
SLIGHT RISK FOR SEVERE THUNDERSTORMS FOR SUNDAY AFTERNOON THROUGH
SUNDAY NIGHT. THE MAIN THREAT WITH ANY STORMS DURING THIS TIME
FRAME WILL BE DAMAGING WINDS AND HAIL. WE COULD SEE A COUPLE OF
ROUNDS OF THUNDERSTORMS OVERNIGHT SUNDAY NIGHT AHEAD OF A
SHORTWAVE AND ITS ASSOCIATED SURFACE LOW...WHICH STRENGTHEN OVER
SOUTHERN ILLINOIS AND HEAD NORTHEAST ON MONDAY.
THE FRONTAL PASSAGE ASSOCIATED WITH THE AFOREMENTIONED LOW WILL
OCCUR ON MONDAY AND WILL ALLOW FOR TEMPERATURES TO COOL INTO THE
40S OVERNIGHT MONDAY NIGHT. ALL PRECIP SHOULD PUSH EAST OF THE
TENNESSEE VALLEY TUESDAY NIGHT. A SURFACE HIGH MOVES IN ON TUESDAY
AND GIVES US A MUCH NEEDED DRY AND RELATIVELY COOL DAY WITH HIGH
TEMPERATURES IN THE MID 60S.
THE NEXT CHANCE OF PRECIP ENTERS THE FORECAST WEDNESDAY EVENING AS
A WEAK FRONT BRINGS A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH
THE AREA. COULD SEE A BREAK ON FRIDAY AS THAT MOISTURE PUSHES
SOUTH...THEN ANOTHER SURFACE LOW BRINGS ADDITIONAL THUNDERSTORM
CHANCES FRIDAY NIGHT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
336 AM CDT FRI APR 17 2015
.DISCUSSION...
BROAD SOUTHWEST FLOW ALOFT REMAINS IN PLACE ACROSS THE MID SOUTH
TODAY OUT AHEAD OF A LARGE UPPER LEVEL LOW PRESSURE SYSTEM
SPINNING OVER THE FOUR CORNERS REGION OF THE INTERMOUNTAIN WEST.
DEEPER MOISTURE REMAINS IN PLACE ACROSS THE SOUTHERN HALF OF THE
FORECAST AREA TO THE SOUTH OF AN INVERTED SURFACE TROUGH THAT
REMAINS STRETCHED ACROSS NORTHERN PORTIONS OF THE REGION. A MID
LEVEL SHORTWAVE NOTED FROM WATER VAPOR IMAGERY OVER THE ARKLATEX
EARLY THIS MORNING WILL CONTINUE TO LIFT NORTHEAST TODAY. THIS
SHOULD COMBINE WITH INCREASING INSTABILITY TO SUPPORT HIGH END
CHANCES FOR SHOWERS AND THUNDERSTORMS BASICALLY ALONG AND SOUTH OF
INTERSTATE 40. CHANCES DECREASE WITH NORTHERN EXTENT AS OVERALL
MOISTURE DECREASES. AS THE SHORTWAVE MOVES EAST OF THE REGION
TONIGHT AND INSTABILITY WANES...CONVECTION SHOULD DIMINISH.
A STRONGER MID LEVEL SHORTWAVE SHOULD EJECT OUT OF THE SOUTHERN
PLAINS AND ACROSS THE MID SOUTH ON SATURDAY AND SATURDAY NIGHT.
ENHANCED MOISTURE AND LIFT FROM THIS FEATURE SHOULD SUPPORT LIKELY
TO CATEGORICAL CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS MUCH
OF THE REGION BY SATURDAY AFTERNOON AND AREAWIDE SATURDAY NIGHT.
PERIODS OF HEAVY RAINFALL WILL BE POSSIBLE DURING THIS TIME PERIOD
AS RICH MOISTURE SPREADS NORTH FROM THE GULF OF MEXICO.
CONSIDERING THE RECENT WET PATTERN OF LATE...SOME FLOODING
CONCERNS WILL DEVELOP LATER SATURDAY AND SATURDAY NIGHT. A FLOOD
WATCH MAY BE NEEDED IN LATER FORECASTS IF THIS TREND CONTINUES.
THE UPPER LEVEL LOW PRESSURE WILL FINALLY LIFT NORTHEAST ACROSS
THE MISSISSIPPI RIVER VALLEY AS AN OPEN WAVE BY SUNDAY AND SUNDAY
NIGHT. THIS SHOULD FORCE A COLD FRONT EAST ACROSS THE REGION
SUNDAY NIGHT. THE ATMOSPHERE SHOULD DESTABILIZE ACROSS THE REGION
BY SUNDAY AFTERNOON AND EVENING AS THE UPPER TROUGH OVERSPREADS
THE REGION. THIS SHOULD SUPPORT THE DEVELOPMENT OF ADDITIONAL
SHOWERS AND THUNDERSTORMS ALONG AND AHEAD OF THE FRONT. THE
ENVIRONMENT APPEARS TO BECOME MORE SUPPORTIVE OF SEVERE STORM
DEVELOPMENT DURING THIS TIME PERIOD AS DEEP LAYER SHEAR INCREASES
AND LAPSE RATES STEEPEN. STORM MODE APPEARS TO INITIALLY SUPPORT A
MIX OF SHORT LINE SEGMENTS AND POTENTIALLY SUPERCELLS WHICH
QUICKLY CONGEAL INTO A SQUALL LINE AS MID LEVEL FORCING
STRENGTHENS. IT STILL REMAINS A BIT EARLY TO FORECAST OVERALL
THREATS WITH CERTAINTY THIS FAR OUT...BUT WILL BEGIN TO MENTION
THIS SEVERE WEATHER THREAT IN THE LATEST HAZARDOUS WEATHER
OUTLOOK.
THE FRONT SHOULD SWEEP EAST OF THE REGION BY EARLY MONDAY MORNING
WITH ANY LINGERING SHOWERS AND THUNDERSTORMS ACROSS THE EAST
ENDING. MUCH DRIER AND SLIGHTLY COOLER CONDITIONS WILL MOVE INTO
THE REGION FOR EARLY NEXT WEEK AS HIGH PRESSURE BUILDS OVERHEAD.
PLEASANT SPRING WEATHER WITH SLIGHTLY BELOW AVERAGE TEMPERATURES
WILL PERSIST FROM MONDAY THROUGH WEDNESDAY OF NEXT WEEK.
A MORE UNSETTLED AND MOISTER WEATHER PATTERN SHOULD BECOME
ESTABLISHED ACROSS THE MID SOUTH ONCE AGAIN BY THE END OF NEXT
WEEK.
JLH
&&
.AVIATION...
06Z TAF CYCLE
STRATUS IS CURRENTLY SPREADING NW ACROSS THE CWA. KTUP IS ALREADY
EXPERIENCING IFR CIGS AND EXPECT KMKL AND KMEM TO SEE THEM BY 7Z.
MEANWHILE...EXPECT SOME FOG TO BEGIN DEVELOPING AT KJBR AND
CONDITIONS SHOULD DETERIORATE RAPIDLY TO VLIFR. STRATUS AND FOG MAY
BE SLOW TO LIFT IN THE MORNING. LATEST HRRR SHOWS SHRAS POSSIBLY A
FEW TSRAS DEVELOPING ACROSS N MS AROUND 15Z THAT WILL SPREAD NORTH
AND EAST INTO THE KMEM AND KTUP AREA THROUGH AT LEAST 20-21Z. LIGHT
AND VARIABLE WINDS EXPECTED THROUGH THE PERIOD.
KRM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1221 AM CDT FRI APR 17 2015
.UPDATE...
UPDATED TO ADD 06Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 909 PM CDT THU APR 16 2015/
UPDATE...EVENING UPDATE.
DISCUSSION...
DECREASED POPS BASED ON RADAR COVERAGE. SHORT TERM GUIDANCE HAS
BEEN PRETTY ACCURATE LATELY...AND IT HAS MORE DEVELOPMENT ACROSS
EAST ARKANSAS AND NORTH MISSISSIPPI TOWARD MORNING. TEMPERATURES
ARE ON TRACK.
PREV DISCUSSION... /ISSUED 650 PM CDT THU APR 16 2015/
DISCUSSION... /ISSUED 307 PM CDT THU APR 16 2015/
SKIES ARE MOSTLY SUNNY OVER A LARGE PORTION OF THE FORECAST AREA
THIS AFTERNOON WITH TEMPERATURES RANGING FROM THE UPPER 60S TO
LOWER 80S. A FEW SHOWERS AND ISOLATED THUNDERSTORMS WERE MOVING
ACROSS PORTIONS OF NORTHEAST MISSISSIPPI AT THIS TIME. THIS
ACTIVITY HAS FORMED NEAR A WEAK FRONTAL BOUNDARY WHICH EXTENDS
FROM CENTRAL MISSISSIPPI THROUGH SOUTHEAST ALABAMA AND INTO NORTH
FLORIDA.
THIS BOUNDARY IS EXPECTED TO LIFT NORTH TONIGHT AND AS IT DOES
ADDITIONAL SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP WITH
THE BEST CHANCE OF THUNDERSTORMS EXPECTED OVER NORTHEAST
MISSISSIPPI. TEMPERATURES WILL REMAIN ON THE WARM SIDE WITH LOWS
FRIDAY MORNING IN THE UPPER 50S TO MID 60S. BY FRIDAY MORNING THE
BOUNDARY WILL RETREAT BACK SOUTH WITH ADDITIONAL SHOWERS AND
THUNDERSTORMS EXPECTED TO DEVELOP MAINLY OVER PORTIONS OF NORTH
MISSISSIPPI. TEMPERATURES WILL REMAIN ON THE WARM SIDE WITH HIGHS
IN THE UPPER 70S TO AROUND 80 DEGREES.
BY FRIDAY NIGHT...AN UPPER LEVEL LOW WILL BE MOVING SLOWLY OUT OF
THE CENTRAL ROCKIES AND INTO THE PLAINS. SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO DEVELOP AHEAD OF THIS SYSTEM WITH SOME OF THIS
ACTIVITY POSSIBLY MOVING INTO MAINLY WESTERN SECTIONS OF THE
FORECAST AREA. ON SATURDAY AS THE UPPER LOW PUSHES FURTHER EAST
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL INCREASE FOR SATURDAY
AND SATURDAY NIGHT.
BY SUNDAY...A COLD FRONT WILL BE MOVING INTO EASTERN OKLAHOMA AND
WESTERN ARKANSAS SO MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED.
THE COLD FRONT WILL MOVE THROUGH THE FORECAST AREA SUNDAY NIGHT
WITH ADDITIONAL SHOWERS AND THUNDERSTORMS. THERE MAY ALSO BE A
SMALL CHANCE OF SEVERE THUNDERSTORMS AHEAD OF THE FRONT.
COOLER AND DRIER AIR WILL MOVE INTO THE REGION BEHIND THE FRONT
ON MONDAY BRINING AN END TO THE THREAT OF THUNDERSTORMS WITH
TEMPERATURES DROPPING BACK CLOSER TO NORMAL LEVELS. DRY WEATHER
WILL CONTINUE INTO TUESDAY AND WEDNESDAY AS WELL WITH HIGH
PRESSURE REMAINING IN CONTROL. TEMPERATURES WILL REMAIN NEAR
NORMAL LEVELS.
ANOTHER COLD FRONT IS EXPECTED TO DROP SOUTH INTO THE CENTRAL
PLAINS AND OHIO VALLEY WEDNESDAY NIGHT AND NEXT THURSDAY. THIS
WILL BRING ANOTHER CHANCE OF SHOWERS FOR WEDNESDAY NIGHT AND A
BETTER CHANCE OF SHOWERS AND THUNDERSTORMS FOR NEXT THURSDAY.
ARS
&&
.AVIATION...
06Z TAF CYCLE
STRATUS IS CURRENTLY SPREADING NW ACROSS THE CWA. KTUP IS ALREADY
EXPERIENCING IFR CIGS AND EXPECT KMKL AND KMEM TO SEE THEM BY 7Z.
MEANWHILE...EXPECT SOME FOG TO BEGIN DEVELOPING AT KJBR AND
CONDITIONS SHOULD DETERIORATE RAPIDLY TO VLIFR. STRATUS AND FOG MAY
BE SLOW TO LIFT IN THE MORNING. LATEST HRRR SHOWS SHRAS POSSIBLY A
FEW TSRAS DEVELOPING ACROSS N MS AROUND 15Z THAT WILL SPREAD NORTH
AND EAST INTO THE KMEM AND KTUP AREA THROUGH AT LEAST 20-21Z. LIGHT
AND VARIABLE WINDS EXPECTED THROUGH THE PERIOD.
KRM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1201 AM CDT FRI APR 17 2015
.UPDATE...FOR 06Z AVIATION DISCUSSION.
&&
.AVIATION...06Z AVIATION DISCUSSION.
SEVERAL ADMS POSSIBLE THRU AT LEAST 17/15Z DUE TO CEILING FORMATION/
FLUCTUATIONS AND FOG FORMATION POTENTIALLY LIMITING VSBYS. UPPER LEVEL
RIDGING INFLUENCES SHOULD AMPLIFY THRU 18/06Z ALSO AND SHOULD LIMIT
CONVECTION POTENTIAL AT TAF SITES...AS SHORT RANGE MODELS SHOWING LITTLE
IN THE WAY OF CONVECTION AFFECTING TAF SITES THRU 17/12Z. EXPECT MVFR
CEILINGS BNA/CSV TO PERSIST THRU AT LEAST 17/15Z. THERE SILL MAYBE ENOUGH
BELIEVE THAT THERE MAYBE ENOUGH CLRING...ESPECIALLY ACROSS NW PORTIONS OF
THE MID STATE...WITH LIGHT WINDS FOR PATCHY FOG DEVELOPMENT...FOR MVFR TO
IFR FOG POSSIBLE...WITH TEMPO LIFR VSBYS POSSIBLE BNA/CSV. EXPECT FOG
DISSIPATION AFTER 17/15Z WITH DISSIPATION IN MVFR/IFR CEILINGS GENERALLY
AFTER 17/18Z. EXPECT VFR AC/CI CEILINGS AFTER 18/02Z AS UPPER LEVEL RIDGING
INFLUENCES BECOME EVEN MORE ENHANCED.
&&
.PREV DISCUSSION.../ISSUED 822 PM CDT THU APR 16 2015/
DISCUSSION...
RADAR IS PRECIP FREE AT THIS TIME BUT CLOUDINESS STILL BLANKETS
MUCH OF THE AREA. MOISTURE IN THE FORM OF SHOWERS AND
THUNDERSTORMS DOES EXIST TO OUR SOUTH AND SOUTHWEST ACROSS MS AND
AL. LATEST HRRR DOES INDICATE THAT SOME OF THIS MOISTURE MAY
APPROACH OUR SOUTHWESTERN AREAS TOWARD 12Z.
UPPER LEVEL PATTERN CONTINUES TO FLOW FROM THE SOUTHWEST. WE ARE
EXPECTING SOME AMPLIFICATION OF A SE-NW UPPER RIDGE BY TOMORROW,
BEFORE THAT HAPPENS HOWEVER...ONE MORE WEAK DISTURBANCE WILL RIDE
NORTHEASTWARD AND JUST ENOUGH UPPER DIVERGENCE MAY HELP PRODUCE
THAT AFOREMENTIONED ACTIVITY TOWARD 12Z.
OTW...DEWPOINT DEPRESSIONS ARE VERY LOW CURRENTLY. NUMERICAL DATA
DOES SUGGEST SOME LOW VSBY CATS. THUS...WILL GO AHEAD AND ADD
PATCHY FOG AREA WIDE FOR AFT 06Z. ADDITIONALLY...WILL OPT TO LOWER
POPS TO 20 PERCENT FOR THE ENTIRE MID STATE EXCEPT FOR OUR
SOUTHWEST...WHERE POPS WILL REMAIN AT 30 PERCENT. JUST SHOWERS
TONIGHT...NO T EXPECTED.
PREV DISCUSSION... /ISSUED 652 PM CDT THU APR 16 2015/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
SEVERAL ADMS POSSIBLE THRU 17/24Z DUE TO CEILING FORMATION/FLUCTUATIONS AND
FOG FORMATION POTENTIALLY LIMITING VSBYS. UPPER LEVEL RIDGING INFLUENCES
SHOULD AMPLIFY THRU 17/24Z ALSO AND SHOULD LIMIT CONVECTION POTENTIAL AT
TAF SITES...AS SHORT RANGE MODELS SHOWING LITTLE IN THE WAY OF CONVECTION
THRU 17/12Z. EXPECT MVFR CEILINGS BNA AND CSV TO PERSIST THRU AT LEAST 17/15Z.
WITH MOISTURE RICH AIRMASS GENERALLY IN PLACE...BELIEVE THAT THERE MAYBE
ENOUGH CLRING...ESPECIALLY ACROSS CNTRL/NW PORTIONS OF THE MID STATE...WITH
LIGHT WINDS FOR PATCHY FOG DEVELOPMENT...FOR MVFR TO IFR FOG POSSIBLE...WITH
TEMPO LIFR VSBYS POSSIBLE BNA/CSV. EXPECT FOG DISSIPATION AFTER 17/15Z WITH
DISSIPATION IN MVFR/IFR CEILINGS AFTER 17/18Z...BUT FOR TAF BREVITY CONCERNS...
DID NOT MENTION IN TAF FORECAST AS THIS TIME.
PREV DISCUSSION.../ISSUED 318 PM CDT THU APR 16 2015/
SHORT TERM...SKIES REMAINED MOSTLY CLOUDY INTO THE EARLY
AFTERNOON OVER EASTERN AND SOUTHERN PARTS OF THE MID-STATE.
MEANWHILE, SKIES BECAME PARTLY CLOUDY OVER THE WEST. AS USUAL FOR
THIS TIME OF YEAR, TEMPS WERE QUICK TO WARM UP ONCE THE SUN POPPED
OUT AND AT 2 PM, CLARKSVILLE WAS EXPERIENCING A TOASTY 74 DEGREES.
TEMPERATURES WERE STRUGGLING A BIT MORE IN THE MOSTLY CLOUDY
AREAS, WITH 2 PM READINGS MAINLY IN THE MIDDLE AND UPPER 60S OVER
EASTERN AND CENTRAL AREAS.
THE SHORTWAVE THAT BROUGHT US THE ROUND OF SHOWERS AND THUNDERSTORMS
LAST NIGHT AND THIS MORNING, WAS CROSSING THE OHIO VALLEY THIS
AFTERNOON AND PUSHING MOST THE SHOWERS AND THUNDERSTORMS TO THE
EAST OF OUR FORECAST AREA. HOWEVER, SINCE THE UPPER LEVEL
DISTURBANCE WAS PASSING SO FAR TO OUR NORTH, A BAND OF RELATIVELY
DEEP MOISTURE WAS SLOW TO PUSH OUT OF OUR EASTERN AND SOUTHERN
COUNTIES. AS A RESULT, BY EARLY AFTERNOON SOME SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS REMAINED ALONG THE CUMBERLAND PLATEAU
AND IN AREAS CLOSE TO THE ALABAMA BORDER.
IT STILL LOOKS LIKE WE`LL GET A TEMPORARY BREAK TONIGHT THROUGH
SATURDAY MORNING FROM THE MORE WIDESPREAD SHOWER AND THUNDERSTORM
ACTIVITY THAT WE`VE SEEN OVER RECENT DAYS. IN ADDITION, AS CLOUDS
DIMINISH FRIDAY NIGHT, BELIEVE OUR SOGGY WET GROUND WILL AID THE
DEVELOPMENT OF AREAS OF FOG--SOME OF WHICH COULD BECOME LOCALLY
DENSE.
ANOTHER SWATH OF DEEP MOISTURE SWINGS NORTHEASTWARD ACROSS THE AREA
SATURDAY AFTERNOON AND SATURDAY NIGHT, BRINGING ANOTHER ROUND OF
SHOWERS AND STORMS AND THE POTENTIAL FOR LOCALLY HEAVY RAINFALL.
SINCE THE RESPONSIBLE SHORTWAVE SHEARS OFF ONCE AGAIN TO THE
NORTH, THE RAIN IS SLOWER TO CLEAR OUT OF OUR EASTERN AREAS, AND
THE CUMBERLAND PLATEAU COULD SEE SHOWERS AND THUNDERSTORMS FOR A
GOOD PART OF SUNDAY AS WELL. ANOTHER INCH OR SO OF RAIN WILL
LIKELY OCCUR, SOME OF WHICH WILL COME IN DOWNPOURS. SINCE GROUNDS
WILL SILL BE PRETTY SOGGY BY THEN, EXPECT RUN OFF TO PRODUCE
PONDING OF WATER IN URBAN LOCATIONS (LIKE NASHVILLE) AND IN LOW LYING
AREAS.
AFTER THE RAIN PASSES EAST OF OUR AREA SUNDAY EVENING, LOOK FOR A
COLD FRONT TO SWEEP ACROSS THE AREA SUNDAY NIGHT AND MONDAY
MORNING, BRINGING ANOTHER ROUND OF RAIN. THIS WILL PROBABLY COME
ACROSS THE AREA AS A RELATIVELY FAST-MOVING BAND OF SHOWERS AND
THUNDERSTORMS, AND BRIEF HEAVY DOWNPOURS MAY ONCE AGAIN OCCUR, AND
CAUSE SOME PONDING IN LOW LYING SPOTS AND URBAN AREAS. HOWEVER,
THE STORMS AND SHOWERS SHOULDN`T LAST LONG, AND BY MONDAY
AFTERNOON WE SHOULD BE DRYING OUT PRETTY WELL, AS HIGH PRESSURE
BUILDS IN FROM THE WEST.
LONG TERM...A DRY SHORTWAVE SWINGS IN MONDAY NIGHT, DEEPENING AN
UPPER LEVEL TROUGH OVER THE GREAT LAKES AND TENNESSEE VALLEY. SOME
PATCHY CLOUDS WILL SPREAD ACROSS THE AREA, BUT DON`T EXPECT ANYTHING
MORE THAN SOME LIGHT SPRINKLES. BY SUNRISE TUESDAY, COOLER AIR WILL
HAVE WORKED IN FROM THE NORTHWEST AND WE`LL BE LOOKING AT
TEMPERATURES IN THE MIDDLE AND UPPER 40S. DRY AND COOL WEATHER
LINGERS INTO WEDNESDAY, WITH LOWS IN THE 40S AND HIGHS FROM THE
MID 60S TO MID 70S.
ATMOSPHERIC MOISTURE INCREASES AGAIN BY LATE NEXT WEEK, CREATING
THE CHANCE FOR MORE SHOWERS AND THUNDERSTORMS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1039 PM CDT SAT APR 18 2015
.AVIATION...
LIGHT NORTH TO NORTHWEST WINDS WILL INCREASE BY MID MORNING SUNDAY
INTO THE 26 TO 32 KNOT RANGE WITH HIGHER GUSTS. WINDS WILL THEN
DECREASE TO LESS THAN 10 KNOTS WITH SUNSET ON SUNDAY. SKIES ARE
EXPECTED TO REMAIN VFR.
&&
.PREV DISCUSSION... /ISSUED 615 PM CDT SAT APR 18 2015/
AVIATION...
A FEW SHOWERS AND THUNDERSTORMS HAVE DEVELOPED UNDER THE COLD CORE OF
THE LOW...SO HAVE ENTERED SOME GUSTY SHOWERS INTO THE TAFS FOR THIS
EVENING. NORTHWEST WINDS WILL GENERALLY REMAIN AT 10 KNOTS OR LESS
OUTSIDE OF THE SHOWERS. NORTHWEST TO NORTH WINDS WILL THEN PICK UP TO
25 TO 30 KNOTS WITH HIGHER GUSTS BY MID MORNING ON SUNDAY. SKIES
SHOULD REMAIN VFR.
PREV DISCUSSION... /ISSUED 521 PM CDT SAT APR 18 2015/
UPDATE...
WEST TEXAS MESONET AND SCHOOL NET OBSERVATIONS SHOW A CONTINUED
DECREASE IN SURFACE DEW POINTS AND VEERING OF SURFACE WINDS ACROSS
THE FAR EASTERN PORTION OF THE TEXAS PANHANDLE. SPC RAP MESOANALYSIS
HAS RESPONDED BY DEPICTING MUCH HIGHER LCL HEIGHTS THAT ARE LESS
FAVORABLE FOR TORNADOES. A MORE FAVORABLE ENVIRONMENT EXISTS FURTHER
EAST INTO OKLAHOMA WHERE SURFACE WINDS REMAINED BACKED AND AT LEAST
SHALLOW LOW LEVEL MOISTURE /DEW POINTS IN THE MID TO UPPER 50S/ IS
PRESENT. A FAIRLY POTENT VORT MAX IS MOVING ACROSS THE TEXAS
PANHANDLE NOW AS SEEN ON WATER VAPOR LOOP AND THIS MAY RESULT IN AN
UPTICK IN CONVECTION OVER THE NEXT COUPLE OF HOURS. HAIL AND WIND
ARE STILL POSSIBLE WITH THE STRONGEST STORMS AS ENOUGH INSTABILITY
REMAINS INTO EARLY EVENING. WILL CONTINUE TO MONITOR TRENDS IN THE
OBSERVATIONS...ESPECIALLY LATER THIS EVENING WHEN MIXING SUBSIDES
AND THE DRYLINE POSSIBLY SHIFTS WESTWARD SOME. THE BEST CHANCE OF
BETTER LOW LEVEL MOISTURE RETURNING TO THE FORECAST AREA WILL BE
ACROSS WHEELER AND COLLINGSWORTH COUNTIES.
BRB
PREV DISCUSSION... /ISSUED 221 PM CDT SAT APR 18 2015/
DISCUSSION...
EARLY THIS AFTERNOON A DEEP CLOSED LOW WAS SITUATED OVER EASTERN
COLORADO AND SLOWLY MOVING EAST. A BAND OF CLOUDS ASSOCIATED WITH A
RELATIVELY POTENT VORT LOBE ROTATING AROUND THE MID-UPPER LOW WAS
EVIDENT IN IR/VIS SATELLITE. SURFACE OBSERVATIONS SHOW LIGHT RAIN
BENEATH THIS BAND OF CLOUDS AT CLAYTON NEW MEXICO AND PRESUMABLY
FURTHER SOUTH-SOUTHWEST EAST OF TUCUMCARI INTO THE FAR WESTERN TEXAS
PANHANDLE WHERE LIGHT ECHOS WERE PRESENT ON REGIONAL RADAR MOSAIC.
FURTHER EAST ACROSS THE TEXAS AND OKLAHOMA PANHANDLE LOW CLOUDS HAVE
DIMINISHED AND/OR SHIFTED INTO OKLAHOMA AS SURFACE WINDS CONTINUE TO
VEER SLIGHTLY. SHALLOW LOW LEVEL MOISTURE SEEN ON 12Z KAMA SOUNDING
REMAINS ACROSS THE EASTERN PANHANDLES EAST OF A DIFFUSE DRYLINE.
THERE REMAINS SOME UNCERTAINTY ON THE POSITION OF THE DRYLINE THAT
IS EXPECTED TO SHARPEN THIS AFTERNOON AS DIABATIC HEATING/MIXING
COMMENCES. USING SHORT RANGE MODEL FORECAST SOUNDINGS AS GUIDANCE ON
THE DEPTH OF MOISTURE OFF THE CAPROCK AND ESPECIALLY FURTHER EAST
NEAR THE OKLAHOMA BORDER LEADS TO FAIRLY HIGH CONFIDENCE ON THE
PREVIOUS FORECAST WHICH RELEGATES ANY SUBSTANTIAL DEEP CONVECTION TO
NEAR OR JUST EAST OF THE OKLAHOMA STATE LINE LATER THIS AFTERNOON.
LOW LEVEL MOISTURE IS DEEPER FROM THERE EASTWARD INTO OKLAHOMA AND
THUS DRYLINE CIRCULATION THAT DEVELOPS STANDS A BETTER CHANCE AT
INITIATING CONVECTION THERE THAN WAS THE CASE FURTHER WEST
YESTERDAY. SO THROUGH THE LATE AFTERNOON AND EVENING THERE IS ONLY A
LOW PROBABILITY OF ISOLATED-SCATTERED CONVECTION ACROSS THE EXTREME
EASTERN PORTION OF THE PANHANDLES WITH BETTER CHANCES OUT OF THE
FORECAST AREA ACROSS WESTERN OKLAHOMA. IF THE ABOVE ASSESSMENT IS
MISPLACED SLIGHTLY EAST THAN ANY STORM THAT DOES DEVELOP ON OUR SIDE
OF THE STATE LINE WOULD HAVE THE POTENTIAL TO BECOME SEVERE DUE TO
MODERATE INSTABILITY AND SUFFICIENT DEEP LAYER SHEAR OF AROUND 30
KNOTS FOR STORM ORGANIZATION/PERSISTENCE. LARGE HAIL WOULD BE THE
PRIMARY THREAT INTO THE EVENING GIVEN STEEP MID LEVEL LAPSE RATES
OWING TO THE APPROACHING MID-UPPER LOW. WILL CONTINUE TO MONITOR
TRENDS IN SURFACE OBSERVATIONS AND DRYLINE EVOLUTION THROUGHOUT THE
AFTERNOON.
FURTHER WEST OF THE DRYLINE...DEEP MIXING WILL OCCUR GENERALLY EAST
OF THE AFOREMENTIONED BAND OF LOW-MID CLOUDS NOW ENTERING THE TEXAS
PANHANDLE. CU FIELD IS INCREASING IMMEDIATELY AHEAD OF THIS. BASES
SHOULD BECOME RELATIVELY HIGH AS MIXED LAYER DEEPENS THROUGH THE
AFTERNOON. WITH FORCING FROM PREVIOUSLY MENTIONED VORT LOBE
CONVECTION MAY BECOME DEEP ENOUGH FOR SHOWERS AND THUNDERSTORMS FOR
MUCH OF THE AREA LATER THIS AFTERNOON. IF CONVECTION BECOMES DEEP
ENOUGH FOR CHARGE SEPARATION AND LIGHTNING...LIMITED INSTABILITY
SHOULD PRECLUDE THE THREAT OF SEVERE THUNDERSTORMS. PROGNOSTICATIONS
FROM THE HI-RES CONVECTION ALLOWING GUIDANCE INCLUDING THE HRRR AND
TTU WRF SEEM TO LINE UP WELL WITH THE ABOVE THINKING.
AS THE MID-UPPER LOW CONTINUES TO SHIFT EAST A COLD FRONT WILL MOVE
THROUGH THE AREA TONIGHT. MODEL GUIDANCE IS IN AGREEMENT IN AN
EVOLUTION OF THE LOW INTO A MORE OPEN AND PROGRESSIVE WAVE THAT WILL
BE EAST OF THE AREA BY TOMORROW AFTERNOON. AN AREA OF MOISTURE ON
THE BACK SIDE OF THIS EVOLVING SHORTWAVE TROUGH FAVORABLY TIMED WITH
PEAK HEATING SHOULD BE ENOUGH FOR EXTENSIVE CUMULUS DEVELOPMENT
DURING THE AFTERNOON POSSIBLY ENOUGH FOR BROKEN SKY CONDITIONS
ESPECIALLY ACROSS THE EASTERN PORTION OF THE AREA. DEPTH OF
CONVECTION IN ROUGHLY THE NORTHEAST THIRD WILL NEED TO BE MONITORED
AS IT MAY BECOME SUFFICIENT FOR A FEW SHOWERS GIVEN RESIDUAL COOL MID
LEVEL TEMPERATURES AND RELATIVELY HIGH TQ INDEX VALUES. ADJUSTED LOW
POPS ON SUNDAY AFTERNOON TO EXTEND A BIT FURTHER SOUTH AND WEST TO
ACCOUNT FOR THIS.
EARLY NEXT WEEK A SPLIT UPPER FLOW PATTERN WILL EXIST WITH STRONG
PERIODICALLY PERTURBED WESTERLY SOUTHERN BRANCH JUST SOUTH OF US AND
NORTHWESTERLY NORTHERN BRANCH ACROSS THE CENTRAL PLAINS. MEAN
RIDGING WILL BE PRESENT OVER THE WESTERN STATES. GRADUALLY
INCREASING 500 MB HEIGHTS AND A SLIGHTLY MORE AMPLIFIED PATTERN WILL
EVOLVE THROUGH THE WEEK ESPECIALLY AS ANOTHER CLOSED LOW DEVELOPS
AND DEEPENS OVER THE SOUTHWESTERN CONUS BY THURSDAY. AS THIS MOVES
EAST THIS WILL PROBABLY RESULT IN ANOTHER CONVECTIVELY ACTIVE
PATTERN FOR THE LATTER HALF OF THE WEEK. AS IS TYPICALLY THE CASE AT
THAT TIME RANGE MODEL GUIDANCE DIFFERS IN TIMING AND AMPLITUDE BUT
THE SIGNAL IS THERE FOR A SCENARIO FAVORING A NORTH/WEST SURGE OF
LOW LEVEL MOISTURE AND FORCING FOR ASCENT RESULTING IN ABOVE CLIMO
PRECIPITATION PROBABILITIES AND THE POSSIBILITY OF SEVERE
THUNDERSTORMS BY MID AND ESPECIALLY LATE WEEK. EVEN BEFORE THEN
THERE WILL BE A FEW OPPORTUNITIES FOR PRECIPITATION EARLIER IN THE
WEEK AS DIFFICULT TO RESOLVE SMALL SHORTWAVE TROUGHS WITHIN MEAN
WEST-NORTHWESTERLY FLOW CROSS THE AREA. CONVECTION MAY EMANATE FROM
THE HIGHER TERRAIN OF COLORADO AND NEW MEXICO AND MOVE INTO THE
PANHANDLES LATE MONDAY AND AGAIN LATE TUESDAY...ALTHOUGH THIS
FORECAST WILL BE LESS DETERMINISTIC WITH TIMING OF HIGHER
PROBABILITIES OF PRECIPITATION AND MORE BROAD BRUSH GIVEN INHERENT
UNCERTAINTIES OF THIS TYPE PATTERN.
BRB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
15/06
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
857 PM CDT SAT APR 18 2015
.DISCUSSION...
WATCHING A LINE OF STRONG/SEVERE STORMS HEADING TOWARD OUR WESTERN
COUNTIES THIS EVENING. AT THIS TIME...SPC WAS NOT PLANNING ON ISSUING
ANY WATCHES WITH THIS STORM COMPLEX. IF THE LATEST RUN OF THE HRRR
IS CORRECT...EXPECT THESE STORMS TO WEAKEN AS THEY MOVE INTO AND
ACROSS OUR AREA. 42
&&
.PREV DISCUSSION... /ISSUED 610 PM CDT SAT APR 18 2015/
DISCUSSION...
SEE 00Z AVIATION DISCUSSION.
AVIATION...
SOUTHERN TAF SITES WILL ENDURE AN HOUR OR SO OF TSRA BUT AFTER
THAT THINGS LOOK TO FINALLY SETTLE DOWN. A DISTURBANCE OVER
CENTRAL TEXAS WILL MOVE EAST THIS EVENING AND COULD BRING A BAND
OF SHRA/TSRA ACROSS THE NORTHERN TAF SITES DURING THE MID EVENING.
THE HRRR INITIALIZED REASONABLY WELL AND HAVE LEANED TOWARD THAT
MODEL FOR TSRA CHANCES TONIGHT. FCST SOUNDINGS SHOW SOME
POTENTIAL FOR CLEARING SKIES LATER TONIGHT. THE GROUND REMAINS
SATURATED AND IF SKIES CLEAR...FEEL THE POTENTIAL FOR FOG...SOME
LOCALLY DENSE WILL BE HIGH. 43
PREV DISCUSSION... /ISSUED 445 PM CDT SAT APR 18 2015/
DISCUSSION...
SENT OUT AN UPDATED FORECAST PACKAGE AND RAISED POPS AREA WIDE DUE
TO ONGOING/DEVELOPING CONVECTION ACROSS THE COASTAL COUNTIES AND
OFF THE COAST...AND FOR DEVELOPING STORMS OUT WEST THAT THE MODELS
HAVE MOVING INTO THE AREA THIS EVENING. SOME OF THE STORMS COULD
HAVE THE POTENTIAL TO BECOME STRONG OR SEVERE...WITH DAMAGING WINDS...
LARGE HAIL...AND LOCALLY HEAVY RAINFALL THE PRIMARY SEVERE WEATHER
THREATS. 42
PREV DISCUSSION... /ISSUED 340 PM CDT SAT APR 18 2015/
DISCUSSION...
THE UPPER LOW OVER EASTERN CO WILL OPEN UP AND SHEAR OUT OVER THE
PLAINS DURING THE NEXT DAY OR TWO. A COUPLE OF SHORTWAVE TROUGHS
MOVING OVERHEAD WILL BRING SCATTERED THUNDERSTORMS ACROSS SE TX
DURING A COUPLE OF EPISODES TONIGHT...THE FIRST DURING THE LATE
AFTERNOON AND EARLY EVENING AND THE SECOND FROM LATE EVENING
INTO THE OVERNIGHT PERIOD. CANNOT RULE OUT THE POSSIBILITY OF AN
ISOLATED OR STRONG THUNDERSTORM. ALTHOUGH THE MAIN STORM ACTION
WELL OFFSHORE OF THE COAST HAS BEEN STEALING MOST OF THE INFLOW
MOISTURE...THE LATEST SATELLITE TRENDS INDICATE THAT THE STORMS
NEAR MATAGORDA BAY WERE BEGINNING TO EXHIBIT COOLING CLOUD TOPS.
THERE IS ALSO A SLIGHT CHANCE THAT THE STORMS OVER THE FAR
SOUTHWESTERN SET OF COUNTIES MAY CONTAIN LOCALLY HEAVY RAINFALL
DURING THE REMAINING AFTERNOON HOURS. THE SECOND ROUND OF STORMS
WAS BEING FORECASTED BY THE HRRR AND TEXAS TECH WRF TO MOVE OVER
THE NORTHWESTERN AND NORTHERN SET OF COUNTIES BETWEEN ABOUT 9 PM
AND 2 AM OR SO. RAP FORECAST SOUNDING SHOW THE POTENTIAL FOR
ISOLATED STRONG OR SEVERE STORMS WITH THESE AS WELL.
HIGH PRESSURE SHOULD THEN BUILD OVERHEAD SUNDAY AND MONDAY AND
LOWER THE RAIN CHANCES. BOTH THE GFS AND ECMWF AGREE WITH ONSHORE
WINDS AND RAIN CHANCES RETURNING BY WEDNESDAY.
MARINE...
AN UPPER LEVEL DISTURBANCE WILL GENERATE SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS ACROSS THE COASTAL WATERS THIS EVENING.
SOME STORMS COULD BE STRONG. OTHERWISE...ONSHORE FLOW WILL PERSIST
THROUGH SUNDAY. A COLD FRONT WILL PUSH OFF THE COAST SUNDAY NIGHT
WITH MODERATE OFFSHORE WINDS IN ITS WAKE. WINDS WILL DIMINISH AND
VEER BACK TO THE SOUTHEAST BY LATE TUESDAY NIGHT AS HIGH PRESSURE
PUSHES OFF TO THE EAST. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 63 85 56 75 54 / 50 20 10 10 20
HOUSTON (IAH) 64 85 61 78 57 / 50 20 20 10 10
GALVESTON (GLS) 69 81 66 77 66 / 50 20 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...42
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
615 PM CDT SAT APR 18 2015
.AVIATION...
A FEW SHOWERS AND THUNDERSTORMS HAVE DEVELOPED UNDER THE COLD CORE OF
THE LOW...SO HAVE ENTERED SOME GUSTY SHOWERS INTO THE TAFS FOR THIS
EVENING. NORTHWEST WINDS WILL GENERALLY REMAIN AT 10 KNOTS OR LESS
OUTSIDE OF THE SHOWERS. NORTHWEST TO NORTH WINDS WILL THEN PICK UP TO
25 TO 30 KNOTS WITH HIGHER GUSTS BY MID MORNING ON SUNDAY. SKIES
SHOULD REMAIN VFR.
&&
.PREV DISCUSSION... /ISSUED 521 PM CDT SAT APR 18 2015/
UPDATE...
WEST TEXAS MESONET AND SCHOOL NET OBSERVATIONS SHOW A CONTINUED
DECREASE IN SURFACE DEW POINTS AND VEERING OF SURFACE WINDS ACROSS
THE FAR EASTERN PORTION OF THE TEXAS PANHANDLE. SPC RAP MESOANALYSIS
HAS RESPONDED BY DEPICTING MUCH HIGHER LCL HEIGHTS THAT ARE LESS
FAVORABLE FOR TORNADOES. A MORE FAVORABLE ENVIRONMENT EXISTS FURTHER
EAST INTO OKLAHOMA WHERE SURFACE WINDS REMAINED BACKED AND AT LEAST
SHALLOW LOW LEVEL MOISTURE /DEW POINTS IN THE MID TO UPPER 50S/ IS
PRESENT. A FAIRLY POTENT VORT MAX IS MOVING ACROSS THE TEXAS
PANHANDLE NOW AS SEEN ON WATER VAPOR LOOP AND THIS MAY RESULT IN AN
UPTICK IN CONVECTION OVER THE NEXT COUPLE OF HOURS. HAIL AND WIND
ARE STILL POSSIBLE WITH THE STRONGEST STORMS AS ENOUGH INSTABILITY
REMAINS INTO EARLY EVENING. WILL CONTINUE TO MONITOR TRENDS IN THE
OBSERVATIONS...ESPECIALLY LATER THIS EVENING WHEN MIXING SUBSIDES
AND THE DRYLINE POSSIBLY SHIFTS WESTWARD SOME. THE BEST CHANCE OF
BETTER LOW LEVEL MOISTURE RETURNING TO THE FORECAST AREA WILL BE
ACROSS WHEELER AND COLLINGSWORTH COUNTIES.
BRB
PREV DISCUSSION... /ISSUED 221 PM CDT SAT APR 18 2015/
DISCUSSION...
EARLY THIS AFTERNOON A DEEP CLOSED LOW WAS SITUATED OVER EASTERN
COLORADO AND SLOWLY MOVING EAST. A BAND OF CLOUDS ASSOCIATED WITH A
RELATIVELY POTENT VORT LOBE ROTATING AROUND THE MID-UPPER LOW WAS
EVIDENT IN IR/VIS SATELLITE. SURFACE OBSERVATIONS SHOW LIGHT RAIN
BENEATH THIS BAND OF CLOUDS AT CLAYTON NEW MEXICO AND PRESUMABLY
FURTHER SOUTH-SOUTHWEST EAST OF TUCUMCARI INTO THE FAR WESTERN TEXAS
PANHANDLE WHERE LIGHT ECHOS WERE PRESENT ON REGIONAL RADAR MOSAIC.
FURTHER EAST ACROSS THE TEXAS AND OKLAHOMA PANHANDLE LOW CLOUDS HAVE
DIMINISHED AND/OR SHIFTED INTO OKLAHOMA AS SURFACE WINDS CONTINUE TO
VEER SLIGHTLY. SHALLOW LOW LEVEL MOISTURE SEEN ON 12Z KAMA SOUNDING
REMAINS ACROSS THE EASTERN PANHANDLES EAST OF A DIFFUSE DRYLINE.
THERE REMAINS SOME UNCERTAINTY ON THE POSITION OF THE DRYLINE THAT
IS EXPECTED TO SHARPEN THIS AFTERNOON AS DIABATIC HEATING/MIXING
COMMENCES. USING SHORT RANGE MODEL FORECAST SOUNDINGS AS GUIDANCE ON
THE DEPTH OF MOISTURE OFF THE CAPROCK AND ESPECIALLY FURTHER EAST
NEAR THE OKLAHOMA BORDER LEADS TO FAIRLY HIGH CONFIDENCE ON THE
PREVIOUS FORECAST WHICH RELEGATES ANY SUBSTANTIAL DEEP CONVECTION TO
NEAR OR JUST EAST OF THE OKLAHOMA STATE LINE LATER THIS AFTERNOON.
LOW LEVEL MOISTURE IS DEEPER FROM THERE EASTWARD INTO OKLAHOMA AND
THUS DRYLINE CIRCULATION THAT DEVELOPS STANDS A BETTER CHANCE AT
INITIATING CONVECTION THERE THAN WAS THE CASE FURTHER WEST
YESTERDAY. SO THROUGH THE LATE AFTERNOON AND EVENING THERE IS ONLY A
LOW PROBABILITY OF ISOLATED-SCATTERED CONVECTION ACROSS THE EXTREME
EASTERN PORTION OF THE PANHANDLES WITH BETTER CHANCES OUT OF THE
FORECAST AREA ACROSS WESTERN OKLAHOMA. IF THE ABOVE ASSESSMENT IS
MISPLACED SLIGHTLY EAST THAN ANY STORM THAT DOES DEVELOP ON OUR SIDE
OF THE STATE LINE WOULD HAVE THE POTENTIAL TO BECOME SEVERE DUE TO
MODERATE INSTABILITY AND SUFFICIENT DEEP LAYER SHEAR OF AROUND 30
KNOTS FOR STORM ORGANIZATION/PERSISTENCE. LARGE HAIL WOULD BE THE
PRIMARY THREAT INTO THE EVENING GIVEN STEEP MID LEVEL LAPSE RATES
OWING TO THE APPROACHING MID-UPPER LOW. WILL CONTINUE TO MONITOR
TRENDS IN SURFACE OBSERVATIONS AND DRYLINE EVOLUTION THROUGHOUT THE
AFTERNOON.
FURTHER WEST OF THE DRYLINE...DEEP MIXING WILL OCCUR GENERALLY EAST
OF THE AFOREMENTIONED BAND OF LOW-MID CLOUDS NOW ENTERING THE TEXAS
PANHANDLE. CU FIELD IS INCREASING IMMEDIATELY AHEAD OF THIS. BASES
SHOULD BECOME RELATIVELY HIGH AS MIXED LAYER DEEPENS THROUGH THE
AFTERNOON. WITH FORCING FROM PREVIOUSLY MENTIONED VORT LOBE
CONVECTION MAY BECOME DEEP ENOUGH FOR SHOWERS AND THUNDERSTORMS FOR
MUCH OF THE AREA LATER THIS AFTERNOON. IF CONVECTION BECOMES DEEP
ENOUGH FOR CHARGE SEPARATION AND LIGHTNING...LIMITED INSTABILITY
SHOULD PRECLUDE THE THREAT OF SEVERE THUNDERSTORMS. PROGNOSTICATIONS
FROM THE HI-RES CONVECTION ALLOWING GUIDANCE INCLUDING THE HRRR AND
TTU WRF SEEM TO LINE UP WELL WITH THE ABOVE THINKING.
AS THE MID-UPPER LOW CONTINUES TO SHIFT EAST A COLD FRONT WILL MOVE
THROUGH THE AREA TONIGHT. MODEL GUIDANCE IS IN AGREEMENT IN AN
EVOLUTION OF THE LOW INTO A MORE OPEN AND PROGRESSIVE WAVE THAT WILL
BE EAST OF THE AREA BY TOMORROW AFTERNOON. AN AREA OF MOISTURE ON
THE BACK SIDE OF THIS EVOLVING SHORTWAVE TROUGH FAVORABLY TIMED WITH
PEAK HEATING SHOULD BE ENOUGH FOR EXTENSIVE CUMULUS DEVELOPMENT
DURING THE AFTERNOON POSSIBLY ENOUGH FOR BROKEN SKY CONDITIONS
ESPECIALLY ACROSS THE EASTERN PORTION OF THE AREA. DEPTH OF
CONVECTION IN ROUGHLY THE NORTHEAST THIRD WILL NEED TO BE MONITORED
AS IT MAY BECOME SUFFICIENT FOR A FEW SHOWERS GIVEN RESIDUAL COOL MID
LEVEL TEMPERATURES AND RELATIVELY HIGH TQ INDEX VALUES. ADJUSTED LOW
POPS ON SUNDAY AFTERNOON TO EXTEND A BIT FURTHER SOUTH AND WEST TO
ACCOUNT FOR THIS.
EARLY NEXT WEEK A SPLIT UPPER FLOW PATTERN WILL EXIST WITH STRONG
PERIODICALLY PERTURBED WESTERLY SOUTHERN BRANCH JUST SOUTH OF US AND
NORTHWESTERLY NORTHERN BRANCH ACROSS THE CENTRAL PLAINS. MEAN
RIDGING WILL BE PRESENT OVER THE WESTERN STATES. GRADUALLY
INCREASING 500 MB HEIGHTS AND A SLIGHTLY MORE AMPLIFIED PATTERN WILL
EVOLVE THROUGH THE WEEK ESPECIALLY AS ANOTHER CLOSED LOW DEVELOPS
AND DEEPENS OVER THE SOUTHWESTERN CONUS BY THURSDAY. AS THIS MOVES
EAST THIS WILL PROBABLY RESULT IN ANOTHER CONVECTIVELY ACTIVE
PATTERN FOR THE LATTER HALF OF THE WEEK. AS IS TYPICALLY THE CASE AT
THAT TIME RANGE MODEL GUIDANCE DIFFERS IN TIMING AND AMPLITUDE BUT
THE SIGNAL IS THERE FOR A SCENARIO FAVORING A NORTH/WEST SURGE OF
LOW LEVEL MOISTURE AND FORCING FOR ASCENT RESULTING IN ABOVE CLIMO
PRECIPITATION PROBABILITIES AND THE POSSIBILITY OF SEVERE
THUNDERSTORMS BY MID AND ESPECIALLY LATE WEEK. EVEN BEFORE THEN
THERE WILL BE A FEW OPPORTUNITIES FOR PRECIPITATION EARLIER IN THE
WEEK AS DIFFICULT TO RESOLVE SMALL SHORTWAVE TROUGHS WITHIN MEAN
WEST-NORTHWESTERLY FLOW CROSS THE AREA. CONVECTION MAY EMANATE FROM
THE HIGHER TERRAIN OF COLORADO AND NEW MEXICO AND MOVE INTO THE
PANHANDLES LATE MONDAY AND AGAIN LATE TUESDAY...ALTHOUGH THIS
FORECAST WILL BE LESS DETERMINISTIC WITH TIMING OF HIGHER
PROBABILITIES OF PRECIPITATION AND MORE BROAD BRUSH GIVEN INHERENT
UNCERTAINTIES OF THIS TYPE PATTERN.
BRB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
15/06
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
610 PM CDT SAT APR 18 2015
.DISCUSSION...
SEE 00Z AVIATION DISCUSSION.
&&
.AVIATION...
SOUTHERN TAF SITES WILL ENDURE AN HOUR OR SO OF TSRA BUT AFTER
THAT THINGS LOOK TO FINALLY SETTLE DOWN. A DISTURBANCE OVER
CENTRAL TEXAS WILL MOVE EAST THIS EVENING AND COULD BRING A BAND
OF SHRA/TSRA ACROSS THE NORTHERN TAF SITES DURING THE MID EVENING.
THE HRRR INITIALIZED REASONABLY WELL AND HAVE LEANED TOWARD THAT
MODEL FOR TSRA CHANCES TONIGHT. FCST SOUNDINGS SHOW SOME
POTENTIAL FOR CLEARING SKIES LATER TONIGHT. THE GROUND REMAINS
SATURATED AND IF SKIES CLEAR...FEEL THE POTENTIAL FOR FOG...SOME
LOCALLY DENSE WILL BE HIGH. 43
&&
.PREV DISCUSSION... /ISSUED 445 PM CDT SAT APR 18 2015/
DISCUSSION...
SENT OUT AN UPDATED FORECAST PACKAGE AND RAISED POPS AREA WIDE DUE
TO ONGOING/DEVELOPING CONVECTION ACROSS THE COASTAL COUNTIES AND
OFF THE COAST...AND FOR DEVELOPING STORMS OUT WEST THAT THE MODELS
HAVE MOVING INTO THE AREA THIS EVENING. SOME OF THE STORMS COULD
HAVE THE POTENTIAL TO BECOME STRONG OR SEVERE...WITH DAMAGING WINDS...
LARGE HAIL...AND LOCALLY HEAVY RAINFALL THE PRIMARY SEVERE WEATHER
THREATS. 42
PREV DISCUSSION... /ISSUED 340 PM CDT SAT APR 18 2015/
DISCUSSION...
THE UPPER LOW OVER EASTERN CO WILL OPEN UP AND SHEAR OUT OVER THE
PLAINS DURING THE NEXT DAY OR TWO. A COUPLE OF SHORTWAVE TROUGHS
MOVING OVERHEAD WILL BRING SCATTERED THUNDERSTORMS ACROSS SE TX
DURING A COUPLE OF EPISODES TONIGHT...THE FIRST DURING THE LATE
AFTERNOON AND EARLY EVENING AND THE SECOND FROM LATE EVENING
INTO THE OVERNIGHT PERIOD. CANNOT RULE OUT THE POSSIBILITY OF AN
ISOLATED OR STRONG THUNDERSTORM. ALTHOUGH THE MAIN STORM ACTION
WELL OFFSHORE OF THE COAST HAS BEEN STEALING MOST OF THE INFLOW
MOISTURE...THE LATEST SATELLITE TRENDS INDICATE THAT THE STORMS
NEAR MATAGORDA BAY WERE BEGINNING TO EXHIBIT COOLING CLOUD TOPS.
THERE IS ALSO A SLIGHT CHANCE THAT THE STORMS OVER THE FAR
SOUTHWESTERN SET OF COUNTIES MAY CONTAIN LOCALLY HEAVY RAINFALL
DURING THE REMAINING AFTERNOON HOURS. THE SECOND ROUND OF STORMS
WAS BEING FORECASTED BY THE HRRR AND TEXAS TECH WRF TO MOVE OVER
THE NORTHWESTERN AND NORTHERN SET OF COUNTIES BETWEEN ABOUT 9 PM
AND 2 AM OR SO. RAP FORECAST SOUNDING SHOW THE POTENTIAL FOR
ISOLATED STRONG OR SEVERE STORMS WITH THESE AS WELL.
HIGH PRESSURE SHOULD THEN BUILD OVERHEAD SUNDAY AND MONDAY AND
LOWER THE RAIN CHANCES. BOTH THE GFS AND ECMWF AGREE WITH ONSHORE
WINDS AND RAIN CHANCES RETURNING BY WEDNESDAY.
MARINE...
AN UPPER LEVEL DISTURBANCE WILL GENERATE SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS ACROSS THE COASTAL WATERS THIS EVENING.
SOME STORMS COULD BE STRONG. OTHERWISE...ONSHORE FLOW WILL PERSIST
THROUGH SUNDAY. A COLD FRONT WILL PUSH OFF THE COAST SUNDAY NIGHT
WITH MODERATE OFFSHORE WINDS IN ITS WAKE. WINDS WILL DIMINISH AND
VEER BACK TO THE SOUTHEAST BY LATE TUESDAY NIGHT AS HIGH PRESSURE
PUSHES OFF TO THE EAST. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 79 63 85 56 75 / 50 50 20 10 10
HOUSTON (IAH) 80 64 85 61 78 / 50 50 20 20 10
GALVESTON (GLS) 77 69 81 66 77 / 50 50 20 20 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...42
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
321 PM CDT FRI APR 17 2015
.SHORT TERM...
DRYLINE AT 19Z EXTENDED FROM JUST WEST OF SILVERTON SOUTH TO WHITE
RIVER LAKE AND NEAR LAKE ALAN HENRY. THIS BOUNDARY HAS BEEN FORCED
WEST ALL DAY BY CONVECTIVE OUTFLOWS FARTHER EAST AND RECENT RUNS OF
THE RUC HAVE THE DRYLINE ARRIVING ALONG INTERSTATE 27 BY THIS
EVENING...PERHAPS MUCH SOONER. INSTABILITY-WISE...A NARROW AXIS OF
SBCAPE AROUND 1000 J/KG MAY FULFILL SOME TSTORMS ALONG AND EAST OF
THE DRYLINE THROUGH THE EVENING...BUT VISUAL TRENDS OF TOWERING AND
MODERATE CU SUGGEST DEEPER ASCENT IS LACKING. WATER VAPOR IMAGERY
INDICATE THIS AREA IS BATTLING SUBSIDENCE ALOFT DUE TO AN AXIS OF
PERSISTENT DEEP CONVECTION 60-100 MILES FARTHER EAST. BECAUSE OF
THIS AND LIMITED NWP SUPPORT...POPS HAVE BEEN SCALED BACK TO SLIGHT
CHANCE FOR MOST AREAS OFF THE CAPROCK.
AS THE FOUR CORNERS LOW BEGINS LIFTING NORTHEAST TONIGHT...LOWER
TROPOSPHERIC WINDS WILL VEER MORE WESTERLY ACROSS THE WESTERN HALF
OF THE CWA AND HELP TO NUDGE THE DRYLINE EASTWARD BEFORE DAYBREAK
SAT. MODELS AGREE THE DRYLINE WILL MIX OUT OF OUR EASTERN ZONES BY
MIDDAY AHEAD OF BREEZY SW WINDS...BUT ANY DISRUPTION TO THIS SUCH AS
WE SAW TODAY WITH CONVECTIVE OUTFLOWS COULD SUPPORT A MORE WESTERLY
DRYLINE LOCATION AND NECESSITATE MODIFICATIONS TO OUR DRY FORECAST
FOR SATURDAY. WHEREVER THE DRYLINE ENDS UP...DEEP CONVECTION SHOULD
EASILY UNFOLD BY SAT AFTN UNDER WEAK INHIBITION...STRONGER CYCLONIC
FLOW AND A FAVORABLE MID-LEVEL COLD POCKET OF -20C AT 500MB.
.LONG TERM...
COLD FRONT PROGGED TO MOVE THROUGH THE FCST AREA SUNDAY MORNING
WITH ENOUGH COLD ADVECTION TO RESULT IN HIGHS MAINLY UPPER 60S AND
LOWER 70S WHILE ALSO SCOURING LOW LEVEL MOISTURE OUT OF THE FCST
AREA. MAY SEE SOME CONVECTION ATTEMPT TO DEVELOP ON THE HIGH
TERRAIN OF NRN NM/SRN COLO AND BE DRIVEN TO THE SE ON NWLY UPPER
FLOW...BUT WITH DRY LOW LEVELS WOULD EXPECT IT TO HAVE A HARD
TIME GETTING THIS FAR TO THE SE. SITUATION CHANGES SOME MONDAY
WHEN SOUTH AND SE WINDS BEGIN TO BRING MOISTURE BACK INTO THE
AREA. LOOKS LIKE HIGH TERRAIN CONVECTION WILL HAVE A BETTER CHANCE
OF MOVING THROUGH THE PANHANDLE AND INTO NRN PARTS OF THE FCST
AREA.
THE MIDDLE PART OF THE WEEK WILL THEN BE ONE WITH POSSIBILITY OF
WEAKLY-FORCED DIURNAL DRYLINE STORMS WITH LOW LEVEL MOISTURE
INCREASING WITH TIME...CONFLUENT FLOW ALOFT TRANSITIONING TO WEAK
UPPER RIDGING. 20-30 PCT STORM CHANCES TUESDAY THROUGH FRIDAY LOOK
FINE WITH THIS SYNOPTIC SETUP.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 72 40 70 40 / 10 0 0 10
TULIA 76 43 73 44 / 20 0 0 10
PLAINVIEW 77 44 73 45 / 20 0 0 0
LEVELLAND 75 43 75 46 / 10 0 0 0
LUBBOCK 78 45 76 47 / 20 0 0 0
DENVER CITY 74 44 74 47 / 0 0 0 0
BROWNFIELD 76 45 76 48 / 10 0 0 0
CHILDRESS 68 55 79 51 / 50 20 10 10
SPUR 78 53 79 50 / 40 20 0 0
ASPERMONT 74 56 81 52 / 50 20 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93/07
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1215 AM CDT FRI APR 17 2015
.DISCUSSION...
06Z TAF DISCUSSION IN AVIATION SECTION...
&&
.AVIATION...
CONVECTION STILL ONGOING SO START TARS WITH TSRA/VCTS UNTIL 09Z
WHEN HRRR TRENDS SHOW CONVECTION ENDING. SHOULD HAVE MVFR TYPE
CITS AFTER THAT WITH RAIN COOLED AIRMASS BUT NOT MUCH OTHER
CLEARING. CIGS LIFT TO VFR LATE MORNING THROUGH AFTERNOON. BASED
ON GFS/ECMWF AND WRF RUNS...POSSIBLE MCS MOVING INTO THE AREA LATE
EVENING/FRI NIGHT TIME FRAME. START VCTS AT 22Z UNTIL 04Z TO
HIGHLIGHT THAT THREAT.
39
&&
.PREV DISCUSSION... /ISSUED 953 PM CDT THU APR 16 2015/
UPDATE...
VERY BUSY EVENING AS ADVERTISED. CATEGORICAL POPS IN ORDER THROUGH
MID NIGHT AREA WIDE...OUTSIDE OF THE COAST/SWRN COUNTIES BEHIND
MAIN AREA OF CONVECTION. LATEST MESO ANALYSIS INDICATES
PRIMARY/EFFECTIVE WARM FRONT ESTABLISHED ROUGHLY ALONG AND JUST
SOUTH OF I-10 WITH ABUNDANT MOISTURE /SURFACE DEWPOINTS IN THE
LOWER 70S/ IN PLACE ACROSS THE WARM SECTOR. SPC HAS TORNADO WATCH
IN EFFECT AS ACTIVITY NEAR AND SOUTH OF THIS FRONT INGESTS
MODERATELY UNSTABLE AND WEAKLY CAPPED WARM SECTOR AIR. THIS WILL
INCREASE THE POTENTIAL FOR SPIN UPS UNTIL THE WARM SECTOR ITSELF
BEGINS TO CAP OFF LATER TONIGHT. IMPRESSIVE FEED OF MOISTURE WILL
SUSTAIN THREAT OF HEAVY RAIN WITH ANY ACTIVITY AREA WIDE.
CURRENTLY FFA IS CONFINED TO THE WARM SECTOR WHERE MOST ABUNDANT
FEED OF MOISTURE SHOULD CONFINE THE MOST INTENSE RAINFALL RATES.
HOWEVER FLOODING REMAINS A CONCERN AREA WIDE GIVEN THE EVENING
RAINFALL ACROSS SOME NRN AREAS. THUS...FEEL FFA IS WARRANTED
ACROSS THE CWA THROUGH THE DAY TOMORROW AND WILL EXPAND. WITH
ANOTHER POSSIBLE LATE DAY/EVENING MCS...FFA MAY NEED TO BE
EXTENDED IN LATER FORECASTS THROUGH THE NIGHT FRIDAY/SATURDAY
MORNING.
PREV DISCUSSION... /ISSUED 659 PM CDT THU APR 16 2015/
DISCUSSION...
00Z TAF DISCUSSION IN AVIATION...
AVIATION...
MAIN CONCERN IS OBVIOUSLY CONVECTION. LOOKS LIKE CONVECTION WILL
BE ENDING THROUGH 02-03Z...WILL HOLD ONTO VCTS/TSRA FOR MOST TAF
SITES AS CONVECTION WANES. BASED ON HRRR TRENDS MAY KEEP SOME VCSH
GOING THROUGH THE NIGHT IF ANYTHING RE-DEVELOPS. CONFIDENCE IS NOT
VERY HIGH ON THIS SO ANTICIPATE AMMENDING TAFS TO REMOVE
CONVECTION IN THE SHORT TERM. CIGS SHOULD BE VFR/MVFR OVERNIGHT
INTO TOMORROW MORNING. BASED ON WRF-ARW/TX TECH WRF AND EVEN
SUPPORTED BY GFS...EXPECT LARGE MCS TO MOVE INTO THE AREA IN THE
EVENING SO ADDED MENTION OF VCTS FOR TAFS. STILL TIME TO WORK OUT
THESE DETAILS AND LIKELY BE FOCUS OF 06Z TAFS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 66 79 63 83 59 / 60 50 40 20 20
HOUSTON (IAH) 67 80 64 84 63 / 60 50 40 20 20
GALVESTON (GLS) 70 76 69 78 68 / 60 50 40 20 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
WALLER...WASHINGTON...WHARTON.
GM...SMALL CRAFT ADVISORY UNTIL 4 AM CDT EARLY THIS MORNING FOR THE
FOLLOWING ZONES: GALVESTON BAY...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...33
AVIATION/MARINE...39
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
932 PM EDT SAT APR 18 2015
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST TONIGHT ALLOWING CLOUDS FROM LOW
PRESSURE OVER THE TENNESSEE VALLEY TO SPREAD ACROSS THE REGION
OVERNIGHT. RAIN...HEAVY AT TIMES...WILL FALL SUNDAY INTO SUNDAY
NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF
SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL
CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 912 PM EDT SATURDAY
STILL A FEW DIURNAL SHOWERS ALONG THE BLUE RIDGE BUT THEY ARE
FADING FAST. WILL REMOVE POPS FOR THE REST OF THE EVENING...THEN
INCREASE POPS TOWARDS SUNRISE AS LOW PRESSURE ENTERS THE
TENNESSEE VALLEY. MINOR UPDATES TO OTHER GRIDS.
PREVIOUS DISCUSSION...
AS OF 300 PM EDT SATURDAY
WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.
ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.
PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.
CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...
HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...
MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
AS OF 735 PM EDT SATURDAY...
ISOLATED SHOWERS ALONG THE BLUE RIDGE SHOULD DISSIPATE SHORTLY
WITH LOSS OF HEATING.
MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL
SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT
CEILINGS TO LOWER TO MVFR ON THE 06-09Z TIME RANGE.
A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT
WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY SUNDAY AND
CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG
AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE NOT EXPECTED
TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL CREATE
POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA WILL
BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL WIND
SHEAR.
CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING
THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT
MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT.
WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND
FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING
AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION ARRIVES.
EXTENDED AVIATION...
A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG IT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS
IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL
THE FRONT CLEARS THE REGION MONDAY EVENING
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.
&&
.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...
ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
VAZ015>017-032.
NC...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
NCZ001>003-018>020.
WV...NONE.
&&
$$
SYNOPSIS...PH
NEAR TERM...PH/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...PC/PH
HYDROLOGY...PH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
742 PM EDT SAT APR 18 2015
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST TONIGHT ALLOWING CLOUDS FROM LOW
PRESSURE OVER THE TENNESSEE VALLEY TO SPREAD ACROSS THE REGION
OVERNIGHT. RAIN...HEAVY AT TIMES...WILL FALL SUNDAY INTO SUNDAY
NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF
SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL
CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 712 PM EDT SATURDAY
A FEW ISOLATED SHOWERS AND THUNDERSTORMS POPPED UP THIS
AFTERNOON...MAINLY SOUTH OF HIGHWAY 460 IN THE WEST AND SOUTH OF
THE VA-NC BORDER EAST. THIS CONVECTION WILL FADE WITH LOSE OF
HEATING THIS EVENING. RAIN CHANCES WILL INCREASE OVERNIGHT AS A
STRONG AREA OF LOW PRESSURE APPROACHES THE REGION.
PREVIOUS DISCUSSION...
AS OF 300 PM EDT SATURDAY
WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.
ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.
PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.
CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...
HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...
MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 735 PM EDT SATURDAY...
ISOLATED SHOWERS ALONG THE BLUE RIDGE SHOULD DISSIPATE SHORTLY
WITH LOSS OF HEATING.
MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL
SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT
CEILINGS TO LOWER TO MVFR ON THE 06-09Z TIME RANGE.
A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT
WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY SUNDAY AND
CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG
AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE NOT EXPECTED
TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL CREATE
POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA WILL
BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL WIND
SHEAR.
CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING
THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT
MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT.
WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND
FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING
AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION ARRIVES.
EXTENDED AVIATION...
A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG IT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS
IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL
THE FRONT CLEARS THE REGION MONDAY EVENING
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.
.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...
ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
VAZ015>017-032.
NC...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
NCZ001>003-018>020.
WV...NONE.
&&
$$
SYNOPSIS...PH
NEAR TERM...PH/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...PC/PH
HYDROLOGY...PH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
712 PM EDT SAT APR 18 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE OVER OUR AREA TODAY WILL MOVE EAST ALLOWING
A MOISTURE EASTERLY FLOW TO DEVELOP TONIGHT. A COMPLEX STORM SYSTEM
PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN...HEAVY AT
TIMES...SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE
REGION WITH A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON
MONDAY. DRY AND COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF
NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 712 PM EDT SATURDAY
A FEW ISOLATED SHOWERS AND THUNDERSTORMS POPPED UP THIS
AFTERNOON...MAINLY SOUTH OF HIGHWAY 460 IN THE WEST AND SOUTH OF
THE VA-NC BORDER EAST. THIS CONVECTION WILL FADE WITH LOSE OF
HEATING THIS EVENING. RAIN CHANCES WILL INCREASE OVERNIGHT AS A
STRONG AREA OF LOW PRESSURE APPROACHES THE REGION.
PREVIOUS DISCUSSION...
AS OF 300 PM EDT SATURDAY
WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.
ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.
PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.
CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...
HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...
MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.
&&
.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
AS OF 120 PM EDT SATURDAY...
VFR CONDITIONS WERE NOTED AT ALL THE TAF SITES EARLY THIS
AFTERNOON...BUT FLYING CONDITIONS ARE FORECAST TO DETERIORATE
DURING THE OVERNIGHT HOURS/EARLY MORNING SUNDAY.
FOR THE REMINDER OF TODAY...WEAK CONVERGENCE AND UPSLOPE MAY
GENERATE ISOLD SHWRS OR TSTORMS THIS AFTERNOON...ESPECIALLY NEAR
BLUE RIDGE ALONG OR SOUTH OF VA/NC BORDER...BUT PROBABILITY IS TOO
LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.
MODELS HAVE BEEN CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS
TO LOWER TO MVFR AFTER 08Z. HIGHEST CONFIDENCE IN MVFR CEILINGS
IS AT KBCB AFTER 08Z/2AM.
A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER
MIDNIGHT WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY
SUNDAY AND CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN
PLACE ALONG AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE
NOT EXPECTED TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL
CREATE POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA
WILL BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL
WIND SHEAR.
CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING
THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT
MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT.
WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND
FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING
AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION MOVES ARRIVES.
EXTENDED AVIATION...
A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH
A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN
INTO SUNDAY NIGHT.
THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY
TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS
THE REGION.
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY.
.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...
ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
VAZ015>017-032.
NC...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
NCZ001>003-018>020.
WV...NONE.
&&
$$
SYNOPSIS...PH
NEAR TERM...PH/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/PH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
636 PM EDT FRI APR 17 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND SATURDAY BRINGING
DRY AND WARM WEATHER FOR THE START OF THE WEEKEND. A COMPLEX STORM
SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN
SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH
A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND
COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 635 PM EDT FRIDAY...
UPDATE TO REFLECT CURRENT MAINLY ISOLD COVERAGE OF
SHOWERS FROM FOOTHILLS INTO SOUTHSIDE VA. INCLUDED A COUPLE HOURS
OF CHC POPS ACROSS SOUTHSIDE THROUGH EARLY EVENING WITH CLUSTER
OF SHOWERS THERE...AND SO FAR NOT SEEING ANY SIGNS OF EVEN
INTERCLOUD LIGHTNING WITH CELLS NEAR MTV AND DAN...BUT KEEPING
ISOLD THUNDER IN FCST GIVEN SBCAPES OF 500-800 J/KG....AND SOME
ISOL LTG IN CELLS JUST NORTHEAST OF BUCKINGHAM COUNTY. ALL THIS
ACTIVITY SHOULD SLOWLY DIMINISH AS IT DRIFTS SOUTHEASTWARD INTO
FAR NORTHERN NC BY 8 OR 9PM...AND RECENT HRRR RUNS SEEM TO BE
DOING A BETTER JOB CAPTURING THE SPARSITY OF THE SHALLOW
CONVECTION AND WEAKENING INTO THE EVENING HOURS WITH LOSS OF
HEATING.
SOME OF THE MORE WIDESPREAD LIGHT RAIN OVER FAR SW NC AND UPSTATE
SC WILL SLIDE TO THE NORTHEAST IN ADVANCE OF WEAK SHORT WAVE
HEADING EAST OUT OF TN...BUT PREVIOUS THINKING THAT IT WILL REMAIN
SOUTH OF THE FCST AREA STILL LOOKS ON TRACK. WE DO KEEP A
LINGERING SLIGHT CHC POP ACROSS NW NC MTNS UNTIL A LITTLE AFTER
MIDNIGHT JUST IN CASE...BUT THEN DROP ALL POPS TOWARD MORNING.
PREVIOUS DISCUSSION AS OF 235 PM EDT MONDAY...
AT 18Z...A WEAK SURFACE TROF WAS NOTED JUST EAST OF THE BLUE
RIDGE...AND WEAK CONVERGENCE ALONG THIS BOUNDARY COMBINED WITH SOME
MODEST INSTABILITY (DCAPES 500-700 J/KG) SHOULD GENERATE ISOLATED
SHOWERS AND STORMS ALONG THE BLUE RIDGE AS WELL AS AREAS NORTH OF I-
64 WHERE VISIBLE SATELLITE SHOWS SOME ENHANCED CUMULUS FORMING IN
ADVANCE OF A FAINT UPPER LEVEL DISTURBANCE.
MESOSCALE MODELS ARE OVERDONE ON THIS COVERAGE OF THIS PRECIP...BUT
GENERALLY HAVE A GOOD HANDLE ON THE LOCATION OF DEVELOPMENT.
ANY ISOLATED/WIDELY SCATTERED PRECIP THAT DEVELOPS SHOULD GRADUALLY
DIMINISH TONIGHT...BEFORE AN UPPER LEVEL SHORTWAVE IN WEST TENNESSEE
ZIPS ACROSS NRN NC LATE TONIGHT. THIS SYSTEM WILL BRING AN INCREASE
IN CLOUD COVER...ESPECIALLY ACROSS THE SOUTHERN PORTION OF OUR
FORECAST AREA LATE TONIGHT...AND A FEW SHOWERS MAY BE POSSIBLE.
AT THE SFC...HIGH PRESSURE WILL SLOWLY NOSE SOUTH INTO THE EASTERN
OHIO VALLEY BRINGING A LIGHT NORTH WIND. A SHALLOW LAYER OF MOISTURE
NEAR THE SURFACE WILL REMAIN...WHICH WILL RESULT IN POCKETS OF
FOG...ESPECIALLY WHERE CLOUDS ARE ABSENT TO THE NORTH. LEANED TOWARD
THE WARMER GUIDANCE VALUES WITH CLOUDS.
FOR SATURDAY...HEIGHTS BUILD IN ADVANCE OF A DEEP UPPER LEVEL TROF
IN THE WEST AND TEMPS SHOULD AGAIN WARM WELL INTO THE 70S AND THE
80S IN THE EAST.
A WEAK LOW LEVEL EAST FLOW COMBINED WITH A NOSE OF HIGHER THETA-E
AIR IN NW NC INTO FAR SW VA MAY SPARK ISOLATED SHOWERS/STORMS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...
FOCUS THROUGH THIS PERIOD REMAINS ON A STRONG NEGATIVELY TILTED
UPPER TROUGH PROGGED TO LIFT RAPIDLY NORTHEAST ACROSS THE REGION
SUNDAY INTO EARLY MONDAY. MEANWHILE...ANTECEDENT HIGH PRESSURE
WILL MOVE OFF THE MID-ATLANTIC COAST INTO A NEAR CLASSIC WEDGE
POSITION. STRONG PVA/ISENTROPIC LIFT INDUCED RAINFALL INTO THE
WEDGE AIR MASS WILL ENHANCE/INTENSIFY THE WEDGE SUNDAY.
RAINFALL/QPF WILL BE THE MAIN CONCERN AS THE WEDGE KEEPS A VERY
STABLE/COOL AIR MASS IS PLACE. MOIST SOUTHEAST...UPSLOPE FLOW
ALONG THE BLUE RIDGE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS
WATAUGA NORTHEAST TOWARD FLOYD. AS NOTED YESTERDAY...HOWEVER...THE
SYSTEM WILL REMAIN HIGHLY PROGRESSIVE...LIMITING THE PERIOD OF
HEAVIER RAINFALL TO 12 HOURS OR LESS. WPC HAS PARTS OF THE NC/VA
SOUTHERN VA PIEDMONT OUTLOOKED FOR EXCESSIVE RAINFALL. THE MAIN
CONCERN WITHIN THIS AREA WOULD BE WATAUGA THROUGH
ASHE/WILKES...WITH LESS CONCERN TOWARD THE DANVILLE AREA WHERE
ANTECEDENT CONDITIONS ARE RELATIVELY DRY. IN ADDITION...THE
CONVECTIVE THREAT THROUGH THE HEAVIER RAIN PERIOD AS NOTED ABOVE
IS MINIMAL TO NONE...WHICH SHOULD FURTHER REDUCE THE FLASH FLOOD
THREAT. WILL RE-EVALUATE AGAIN TOMORROW...BUT AT THIS POINT NO
NEED FOR A FLOOD/FLASH FLOOD WATCH. ONE MAY EVENTUALLY BE NEEDED
FOR A SMALL AREA INCLUDING THE NW NC MOUNTAINS AND THE ADJACENT
FOOTHILLS. WENT WELL BELOW GUIDANCE ON MAX TEMPS IN THE WEDGE
SUNDAY...BUT AT OR ABOVE GUIDANCE ON MONDAY IN THE WARM SECTOR.
MAX TEMPS MONDAY WILL BE A GOOD 20 DEGREES WARMER IN MOST AREAS
THAN ON SUNDAY.
MONDAY IS A DIFFERENT STORY. A SIGNIFICANT WARM SECTOR WILL SURGE
NORTHWARD INTO THE REGION MONDAY AFTERNOON BEHIND THE DEPARTING
UPPER TROUGH AND AN APPROACHING STRONG COLD FRONT ASSOCIATED WITH
A DEEPENING BROAD UPPER TROUGH ACROSS THE GREAT LAKES. SEVERAL OF
THE MODELS CONTINUE TO ADVERTISE GOOD POTENTIAL FOR STRONG
THUNDERSTORMS MONDAY AFTERNOON...WITH SIGNIFICANT SVR PARAMETER
NEAR 20000 ACROSS THE PIEDMONT...CAPES NEARING 2000 J/KG WITH AT
LEAST 20-30KTS OF 0-2KM LOW-LEVEL SHEAR AND LIS NEAR -4C. SPC DAY
4 OUTLOOK SUGGESTS THAT DAMAGING WINDS WOULD BE THE MAIN CONCERN
WITH ANY CONVECTION...MOST LIKELY LINEAR ORIENTED...THAT DEVELOPS
ALONG/IN ADVANCE OF THE COLD FRONT MONDAY AFTERNOON/EVENING. THIS
ACTIVITY QUICKLY MOVES EAST OF THE REGION MON AFTERNOON.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...
A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO
BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP
AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY
TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS
PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK.
ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND
COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY
UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND
CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS
THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE
60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND
SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A
DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN
POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT
INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL
COLD/STABLE AIR MASS.
BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL
PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE
ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS
WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER
NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS
OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN
MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS
VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE
MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A
BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES
ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE
WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE
PERIOD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 120 PM EDT FRIDAY...
VFR WITH A FEW MVFR CIGS WERE NOTED ACROSS THE REGION EARLY THIS
AFTERNOON. CLOUDS SHOULD GRADUALLY SCATTERED THROUGH THE REMAINDER
OF THE AFTERNOON AND EARLY EVENING HOURS WITH LIGHT WINDS.
ISOLATED SHOWERS AND THUNDERSTORMS MAY DEVELOP THIS
AFTERNOON...BUT COVERAGE WILL BE VERY LIMITED AND THE CHANCES OF
ONE OF THESE STRAY SHOWERS/STORMS IMPACTING A TAF SITE IS SMALL.
A SHALLOW LAYER OF LOW LEVEL MOISTURE WILL REMAIN IN PLACE
TONIGHT...AND WITH LIGHT WINDS...POCKETS FOG REDUCING VISIBILITIES
TO IFR TO MVFR CATEGORIES WILL BE POSSIBLE LATE TONIGHT.
HIGH PRESSURE BUILDS NOSING DOWN INTO OUR REGION
SATURDAY...WILL USHER IN SLIGHTLY DRIER AIR ALLOWING MORNING
FOG/STRATUS TO QUICKLY ERODE...BRINGING VFR CONDITIONS TO ALL
AREAS BY MID-MORNING SATURDAY.
EXTENDED AVIATION...
A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN
THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR
CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN
PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR
RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PH
NEAR TERM...JH/PH/SK
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...JH/PH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
108 PM CDT FRI APR 17 2015
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND SATURDAY
ISSUED AT 400 AM CDT FRI APR 17 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A WEAK COLD
FRONT SLOWLY MOVING TO THE SOUTHEAST OVER FAR NORTHWEST WISCONSIN.
AHEAD OF THE FRONT...AREAS OF BROKEN MID-CLOUDS ARE MOVING TO THE
EAST OVER CENTRAL AND NORTHERN WISCONSIN. CLEAR SKIES EXIST BEHIND
THIS FRONT OVER THE NORTHERN PLAINS. MEANWHILE...SHOWERS AND
THUNDERSTORMS ARE OCCURRING OVER THE CENTRAL PLAINS AHEAD OF AN
UPPER LOW SPINNING OVER THE 4 CORNERS REGION. FORECAST CONCERNS
INCLUDE HIGH TEMPS AND LOW HUMIDITIES FOR SATURDAY.
TODAY...THE COLD FRONT WILL SLOW AS IT WEAKENS OVER THE NORTHWEST
THIRD OF THE STATE. SCATTERED TO BROKEN MID-LEVEL CLOUD DECK WILL
GRADUALLY DISSIPATE THROUGH THE MORNING AS SUBSIDENCE STRENGTHENS
OVERHEAD. WILL STILL BE SOME RESIDUAL MOISTURE LEFT AROUND
800MB...HOWEVER...THAT WILL TURN INTO A CU FIELD BY LATE MORNING
OVER CENTRAL TO NORTHEAST WISCONSIN. FAR NORTHERN WISCONSIN WILL
SEE AN INFLUX OF DRIER AIR DURING THE AFTERNOON...WHICH WILL DROP
HUMIDITIES INTO THE 20 TO 25 PCT RANGE. HUMIDITIES SHOULD BE ABOVE
CRITICAL CRITERIA ELSEWHERE. RAISED HIGH TEMPS BASED ON 925MB TEMPS
ON THE BETTER PERFORMING NAM AND ECMWF...AND MAY NOT BE HIGH
ENOUGH. TEMPS TO MAX OUT TO NEAR 70 NORTH TO THE UPPER 70S IN THE
WARM SPOTS.
TONIGHT...THE WEAKENING FRONT WILL DROP ACROSS CENTRAL AND
NORTHEAST WISCONSIN DURING THE EVENING WHILE A SECONDARY AND MORE
POTENT FRONT QUICKLY MOVES SOUTH ACROSS NORTHERN AND CENTRAL
WISCONSIN AFTER MIDNIGHT. BEHIND THE SECOND FRONT...WINDS WILL
SHIFT TO THE NORTHEAST AND COULD GUST FOR A COUPLE HOURS TO 20 OR 25
MPH. TEMPS WILL ALSO COOL OFF QUICKLY BEHIND THE FRONT WITH LOWS
FALLING INTO THE MIDDLE 30S NORTH TO THE MIDDLE 40S SOUTH.
SATURDAY...CANADIAN HIGH PRESSURE WILL BUILD SOUTHEAST ACROSS THE
CENTRAL GREAT LAKES. THE AIRMASS ASSOCIATED WITH THIS SURFACE HIGH
IS EXCEPTIONALLY DRY (NAM 850-700MB RH FALLS TO 2 PCT!). THOUGH
HIGH CLOUDS WILL BE ON THE INCREASE DURING THE AFTERNOON AHEAD OF
THE CENTRAL ROCKIES UPPER LOW...SHOULD STILL SEE PLENTY OF SUNSHINE
ALBEIT WITH COOLER TEMPERATURES. CRITICAL RELATIVE HUMIDITIES
BETWEEN 15 TO 25 PCT WILL STILL OCCUR THOUGH NORTH AND WEST OF THE
FOX VALLEY. POTENTIAL IS THERE FOR HUMIDITIES TO FALL LOWER THAN
THIS IF TAPPING OCCURS INTO THIS BONE DRY AIR ALOFT. HIGHS MAINLY
IN THE LOW TO MID 60S AWAY FROM LAKE MICHIGAN.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
ISSUED AT 400 AM CDT FRI APR 17 2015
500MB OPEN TROUGH WILL EVOLVE INTO A CLOSED LOW OVER THE WESTERN
GREAT LAKES REGION BY EARLY NEXT WEEK. COOL CYCLONIC FLOW WILL
CONTINUE FOR THE REMAINDER OF NEXT WEEK AS THE 500MB LOW MEANDERS
ACROSS THE GREAT LAKES REGION/EASTERN CANADA.
MODELS IN SOMEWHAT BETTER AGREEMENT TONIGHT BRINGING THE BEST
CHANCE FOR RAIN SUNDAY INTO SUNDAY NIGHT. WILL CONTINUE A SMALL
CHANCE OF SHOWERS AFTER MIDNIGHT ON SATURDAY NIGHT TO ACCOUNT FOR
A SLIGHTLY QUICKER ARRIVAL THAT SOME OF THE MODELS ARE DEPICTING.
WILL HAVE LIKELY OR LOW END CATEGORICAL CHANCES FOR RAIN ON SUNDAY.
HIGH TEMPERATURES TRICKY DEPENDING ON QUICK THE STEADIER RAINS
ARRIVE. IF RAIN ARRIVES EARLY IN THE DAY SUNDAY...HIGH TEMPERATURES
WILL NEED TO BE LOWERED. COUNTING ON SOME DRY ON BACKSIDE OF THE
RETREATING HIGH PRESSURE SYSTEM TO SLOW THE ARRIVAL OF THE RAIN
ACROSS EASTERN WISCONSIN.
OTHERWISE...BELOW NORMAL TEMPERATURES ARE EXPECTED FOR MUCH OF THE
WEEK WITH CHANCES OF RAIN INTO THE MIDDLE OF NEXT WEEK. STILL HAVE
A CHANCE OF SNOW LATE AT NIGHT OR EARLY IN THE DAY FOR EACH PERIOD
FROM MONDAY NIGHT THROUGH WEDNESDAY. BY THURSDAY...UPPER LOW MAY BE
FAR ENOUGH AWAY FOR JUST A SMALL CHANCE OF RAIN ACROSS THE FAR NORTH.
PREVIOUS FORECAST TEMPERATURES SEEMED REASONABLE WITH ONLY MINOR CHANGES
MADE IN SOME PERIODS.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 108 PM CDT FRI APR 17 2015
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. SCATTERED TO
BROKEN CUMULUS THIS AFTERNOON SHOULD DISSIPATE AROUND/SHORTLY
AFTER SUNSET. A DRY COLD FRONT WILL ARRIVE LATER TONIGHT. WINDS
WILL SHIFT TO THE NORTHEAST BEHIND THE FRONT...AND BECOME GUSTY
FOR A FEW HOURS...ESPECIALLY IN EASTERN WISCONSIN.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......MG
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
604 AM CDT FRI APR 17 2015
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND SATURDAY
ISSUED AT 400 AM CDT FRI APR 17 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A WEAK COLD
FRONT SLOWLY MOVING TO THE SOUTHEAST OVER FAR NORTHWEST WISCONSIN.
AHEAD OF THE FRONT...AREAS OF BROKEN MID-CLOUDS ARE MOVING TO THE
EAST OVER CENTRAL AND NORTHERN WISCONSIN. CLEAR SKIES EXIST BEHIND
THIS FRONT OVER THE NORTHERN PLAINS. MEANWHILE...SHOWERS AND
THUNDERSTORMS ARE OCCURRING OVER THE CENTRAL PLAINS AHEAD OF AN
UPPER LOW SPINNING OVER THE 4 CORNERS REGION. FORECAST CONCERNS
INCLUDE HIGH TEMPS AND LOW HUMIDITIES FOR SATURDAY.
TODAY...THE COLD FRONT WILL SLOW AS IT WEAKENS OVER THE NORTHWEST
THIRD OF THE STATE. SCATTERED TO BROKEN MID-LEVEL CLOUD DECK WILL
GRADUALLY DISSIPATE THROUGH THE MORNING AS SUBSIDENCE STRENGTHENS
OVERHEAD. WILL STILL BE SOME RESIDUAL MOISTURE LEFT AROUND
800MB...HOWEVER...THAT WILL TURN INTO A CU FIELD BY LATE MORNING
OVER CENTRAL TO NORTHEAST WISCONSIN. FAR NORTHERN WISCONSIN WILL
SEE AN INFLUX OF DRIER AIR DURING THE AFTERNOON...WHICH WILL DROP
HUMIDITIES INTO THE 20 TO 25 PCT RANGE. HUMIDITIES SHOULD BE ABOVE
CRITICAL CRITERIA ELSEWHERE. RAISED HIGH TEMPS BASED ON 925MB TEMPS
ON THE BETTER PERFORMING NAM AND ECMWF...AND MAY NOT BE HIGH
ENOUGH. TEMPS TO MAX OUT TO NEAR 70 NORTH TO THE UPPER 70S IN THE
WARM SPOTS.
TONIGHT...THE WEAKENING FRONT WILL DROP ACROSS CENTRAL AND
NORTHEAST WISCONSIN DURING THE EVENING WHILE A SECONDARY AND MORE
POTENT FRONT QUICKLY MOVES SOUTH ACROSS NORTHERN AND CENTRAL
WISCONSIN AFTER MIDNIGHT. BEHIND THE SECOND FRONT...WINDS WILL
SHIFT TO THE NORTHEAST AND COULD GUST FOR A COUPLE HOURS TO 20 OR 25
MPH. TEMPS WILL ALSO COOL OFF QUICKLY BEHIND THE FRONT WITH LOWS
FALLING INTO THE MIDDLE 30S NORTH TO THE MIDDLE 40S SOUTH.
SATURDAY...CANADIAN HIGH PRESSURE WILL BUILD SOUTHEAST ACROSS THE
CENTRAL GREAT LAKES. THE AIRMASS ASSOCIATED WITH THIS SURFACE HIGH
IS EXCEPTIONALLY DRY (NAM 850-700MB RH FALLS TO 2 PCT!). THOUGH
HIGH CLOUDS WILL BE ON THE INCREASE DURING THE AFTERNOON AHEAD OF
THE CENTRAL ROCKIES UPPER LOW...SHOULD STILL SEE PLENTY OF SUNSHINE
ALBEIT WITH COOLER TEMPERATURES. CRITICAL RELATIVE HUMIDITIES
BETWEEN 15 TO 25 PCT WILL STILL OCCUR THOUGH NORTH AND WEST OF THE
FOX VALLEY. POTENTIAL IS THERE FOR HUMIDITIES TO FALL LOWER THAN
THIS IF TAPPING OCCURS INTO THIS BONE DRY AIR ALOFT. HIGHS MAINLY
IN THE LOW TO MID 60S AWAY FROM LAKE MICHIGAN.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
ISSUED AT 400 AM CDT FRI APR 17 2015
500MB OPEN TROUGH WILL EVOLVE INTO A CLOSED LOW OVER THE WESTERN
GREAT LAKES REGION BY EARLY NEXT WEEK. COOL CYCLONIC FLOW WILL
CONTINUE FOR THE REMAINDER OF NEXT WEEK AS THE 500MB LOW MEANDERS
ACROSS THE GREAT LAKES REGION/EASTERN CANADA.
MODELS IN SOMEWHAT BETTER AGREEMENT TONIGHT BRINGING THE BEST
CHANCE FOR RAIN SUNDAY INTO SUNDAY NIGHT. WILL CONTINUE A SMALL
CHANCE OF SHOWERS AFTER MIDNIGHT ON SATURDAY NIGHT TO ACCOUNT FOR
A SLIGHTLY QUICKER ARRIVAL THAT SOME OF THE MODELS ARE DEPICTING.
WILL HAVE LIKELY OR LOW END CATEGORICAL CHANCES FOR RAIN ON SUNDAY.
HIGH TEMPERATURES TRICKY DEPENDING ON QUICK THE STEADIER RAINS
ARRIVE. IF RAIN ARRIVES EARLY IN THE DAY SUNDAY...HIGH TEMPERATURES
WILL NEED TO BE LOWERED. COUNTING ON SOME DRY ON BACKSIDE OF THE
RETREATING HIGH PRESSURE SYSTEM TO SLOW THE ARRIVAL OF THE RAIN
ACROSS EASTERN WISCONSIN.
OTHERWISE...BELOW NORMAL TEMPERATURES ARE EXPECTED FOR MUCH OF THE
WEEK WITH CHANCES OF RAIN INTO THE MIDDLE OF NEXT WEEK. STILL HAVE
A CHANCE OF SNOW LATE AT NIGHT OR EARLY IN THE DAY FOR EACH PERIOD
FROM MONDAY NIGHT THROUGH WEDNESDAY. BY THURSDAY...UPPER LOW MAY BE
FAR ENOUGH AWAY FOR JUST A SMALL CHANCE OF RAIN ACROSS THE FAR NORTH.
PREVIOUS FORECAST TEMPERATURES SEEMED REASONABLE WITH ONLY MINOR CHANGES
MADE IN SOME PERIODS.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 604 AM CDT FRI APR 17 2015
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. SCATTERED TO BROKEN
MID-LEVEL CLOUDS WILL DEPART THIS MORNING...WHICH WILL LEAVE CLEAR
CONDITIONS THROUGH TONIGHT. A DRY COLD FRONT WILL ARRIVE AFTER
MIDNIGHT. WINDS WILL SHIFT TO THE NORTHEAST BEHIND THE FRONT...AND
BECOME GUSTY FOR A FEW HOURS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......MPC
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND SATURDAY
ISSUED AT 400 AM CDT FRI APR 17 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A WEAK COLD
FRONT SLOWLY MOVING TO THE SOUTHEAST OVER FAR NORTHWEST WISCONSIN.
AHEAD OF THE FRONT...AREAS OF BROKEN MID-CLOUDS ARE MOVING TO THE
EAST OVER CENTRAL AND NORTHERN WISCONSIN. CLEAR SKIES EXIST BEHIND
THIS FRONT OVER THE NORTHERN PLAINS. MEANWHILE...SHOWERS AND
THUNDERSTORMS ARE OCCURRING OVER THE CENTRAL PLAINS AHEAD OF AN
UPPER LOW SPINNING OVER THE 4 CORNERS REGION. FORECAST CONCERNS
INCLUDE HIGH TEMPS AND LOW HUMIDITIES FOR SATURDAY.
TODAY...THE COLD FRONT WILL SLOW AS IT WEAKENS OVER THE NORTHWEST
THIRD OF THE STATE. SCATTERED TO BROKEN MID-LEVEL CLOUD DECK WILL
GRADUALLY DISSIPATE THROUGH THE MORNING AS SUBSIDENCE STRENGTHENS
OVERHEAD. WILL STILL BE SOME RESIDUAL MOISTURE LEFT AROUND
800MB...HOWEVER...THAT WILL TURN INTO A CU FIELD BY LATE MORNING
OVER CENTRAL TO NORTHEAST WISCONSIN. FAR NORTHERN WISCONSIN WILL
SEE AN INFLUX OF DRIER AIR DURING THE AFTERNOON...WHICH WILL DROP
HUMIDITIES INTO THE 20 TO 25 PCT RANGE. HUMIDITIES SHOULD BE ABOVE
CRITICAL CRITERIA ELSEWHERE. RAISED HIGH TEMPS BASED ON 925MB TEMPS
ON THE BETTER PERFORMING NAM AND ECMWF...AND MAY NOT BE HIGH
ENOUGH. TEMPS TO MAX OUT TO NEAR 70 NORTH TO THE UPPER 70S IN THE
WARM SPOTS.
TONIGHT...THE WEAKENING FRONT WILL DROP ACROSS CENTRAL AND
NORTHEAST WISCONSIN DURING THE EVENING WHILE A SECONDARY AND MORE
POTENT FRONT QUICKLY MOVES SOUTH ACROSS NORTHERN AND CENTRAL
WISCONSIN AFTER MIDNIGHT. BEHIND THE SECOND FRONT...WINDS WILL
SHIFT TO THE NORTHEAST AND COULD GUST FOR A COUPLE HOURS TO 20 OR 25
MPH. TEMPS WILL ALSO COOL OFF QUICKLY BEHIND THE FRONT WITH LOWS
FALLING INTO THE MIDDLE 30S NORTH TO THE MIDDLE 40S SOUTH.
SATURDAY...CANADIAN HIGH PRESSURE WILL BUILD SOUTHEAST ACROSS THE
CENTRAL GREAT LAKES. THE AIRMASS ASSOCIATED WITH THIS SURFACE HIGH
IS EXCEPTIONALLY DRY (NAM 850-700MB RH FALLS TO 2 PCT!). THOUGH
HIGH CLOUDS WILL BE ON THE INCREASE DURING THE AFTERNOON AHEAD OF
THE CENTRAL ROCKIES UPPER LOW...SHOULD STILL SEE PLENTY OF SUNSHINE
ALBEIT WITH COOLER TEMPERATURES. CRITICAL RELATIVE HUMIDITIES
BETWEEN 15 TO 25 PCT WILL STILL OCCUR THOUGH NORTH AND WEST OF THE
FOX VALLEY. POTENTIAL IS THERE FOR HUMIDITIES TO FALL LOWER THAN
THIS IF TAPPING OCCURS INTO THIS BONE DRY AIR ALOFT. HIGHS MAINLY
IN THE LOW TO MID 60S AWAY FROM LAKE MICHIGAN.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
ISSUED AT 400 AM CDT FRI APR 17 2015
500MB OPEN TROUGH WILL EVOLVE INTO A CLOSED LOW OVER THE WESTERN
GREAT LAKES REGION BY EARLY NEXT WEEK. COOL CYCLONIC FLOW WILL
CONTINUE FOR THE REMAINDER OF NEXT WEEK AS THE 500MB LOW MEANDERS
ACROSS THE GREAT LAKES REGION/EASTERN CANADA.
MODELS IN SOMEWHAT BETTER AGREEMENT TONIGHT BRINGING THE BEST
CHANCE FOR RAIN SUNDAY INTO SUNDAY NIGHT. WILL CONTINUE A SMALL
CHANCE OF SHOWERS AFTER MIDNIGHT ON SATURDAY NIGHT TO ACCOUNT FOR
A SLIGHTLY QUICKER ARRIVAL THAT SOME OF THE MODELS ARE DEPICTING.
WILL HAVE LIKELY OR LOW END CATEGORICAL CHANCES FOR RAIN ON SUNDAY.
HIGH TEMPERATURES TRICKY DEPENDING ON QUICK THE STEADIER RAINS
ARRIVE. IF RAIN ARRIVES EARLY IN THE DAY SUNDAY...HIGH TEMPERATURES
WILL NEED TO BE LOWERED. COUNTING ON SOME DRY ON BACKSIDE OF THE
RETREATING HIGH PRESSURE SYSTEM TO SLOW THE ARRIVAL OF THE RAIN
ACROSS EASTERN WISCONSIN.
OTHERWISE...BELOW NORMAL TEMPERATURES ARE EXPECTED FOR MUCH OF THE
WEEK WITH CHANCES OF RAIN INTO THE MIDDLE OF NEXT WEEK. STILL HAVE
A CHANCE OF SNOW LATE AT NIGHT OR EARLY IN THE DAY FOR EACH PERIOD
FROM MONDAY NIGHT THROUGH WEDNESDAY. BY THURSDAY...UPPER LOW MAY BE
FAR ENOUGH AWAY FOR JUST A SMALL CHANCE OF RAIN ACROSS THE FAR NORTH.
PREVIOUS FORECAST TEMPERATURES SEEMED REASONABLE WITH ONLY MINOR CHANGES
MADE IN SOME PERIODS.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1048 PM CDT THU APR 16 2015
VFR CONDITIONS EXPECTED TONIGHT INTO FRIDAY. A FRONTAL BOUNDARY
WILL DROP SOUTHEASTWARD OVER THE STATE TONIGHT INTO FRIDAY
MORNING. SINCE THE AIR MASS IS DRY...EXPECT A BAND OF MID LEVEL
CLOUDS TO BE ASSOCIATED WITH THE FRONT. LIGHT SOUTHWEST WINDS
SHIFTING NORTHWEST WILL MARK THE FRONTS PASSAGE. LATER
FRIDAY MORNING...DEEP MIXING MAY PRODUCE A WEST WIND OF 5 TO 10 MPH
WHILE WINDS TURN NORTHEAST TO EAST ALONG LAKE MICHIGAN FRIDAY
AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
945 PM MDT SAT APR 18 2015
.UPDATE...
ISSUED AT 945 PM MDT SAT APR 18 2015
THE BAND OF MODERATE TO LOCALLY HEAVY SNOW CONTINUES TO SLOWLY
SHIFT EAST THIS EVENING...BUT PERHAPS SLIGHTLY SLOWER THAN
PREVIOUS THINKING. EARLIER ANALYSIS SUGGESTED A FEW STRONGER SNOW
SHOWERS WERE PERSISTING FROM THE NORTHERN LARAMIE RANGE SOUTHWEST
THROUGH THE ARLINGTON AREA AND ON UP INTO THE SNOWY RANGE AND
SOUTHERNMOST AREAS OF THE SIERRA MADRE MOUNTAINS. SHORT TERM
MODELS ALSO SUGGESTED THAT THE BAND WOULD MOVE SLOW TO THE EAST
THIS EVENING... SO FELT IT PRUDENT TO EXTEND THE WINTER STORM
WARNING AND ADVISORY FOR A FEW MORE HOURS AS SNOW WOULD CONTINUE
TO IMPACT THESE LOCATIONS. ENDED THE HEADLINES AT 11PM AS IR
IMAGERY IS SHOWING A RAPID WARMING OF CLOUD TOPS...AND MODELS
SUGGEST THE BAND WILL HAVE WEAKENED AND SHIFTED ENOUGH TO THE EAST
TO CANCEL ALL WINTER HEADLINES AT THIS TIME.
ALSO...ADDED AREAS OF FOG TO THE SUMMIT THROUGH MIDNIGHT AS
WEBCAMS SHOWED THE DEVELOPMENT OF FOG EARLIER...AND HRRR KEEPS
THE FOG AROUND THROUGH 11PM-12AM.
.UPDATE ISSUED AT 546 PM MDT SAT APR 18 2015
TORNADO WATCH HAS BEEN CANCELLED. CONDITIONS ARE NO LONGER
FAVORABLE FOR TORNADO DEVELOPMENT IN THE SOUTHERN NEBRASKA
PANHANDLE WITH THE BOUNDARY LAYER STABILIZING. A FEW
THUNDERSTORMS AREA STILL POSSIBLE OVER THE NEXT FEW HOURS INTO
SOUTHEAST WYOMING AND PANHANDLE BUT SEVERE WEATHER IS VERY
UNLIKELY. A ROUGE FUNNEL CLOUD AND SMALL HAIL STILL POSSIBLE FOR
THE NEXT HOUR OR SO.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 440 PM MDT SAT APR 18 2015
LOTS OF WEATHER CONCERNS OVER THE NEXT 12 HOURS. HEAVY SNOW
CONTINUES IN A NARROW BAND...MAINLY ACROSS EASTERN/CENTRAL CARBON
COUNTY...STRETCHING NORTHEAST INTO THE NORTHERN LARAMIE RANGE. ON
EITHER SIDE OF THE HEAVY BAND...MAINLY LOOKING AT LIGHT NON
ACCUMULATING SNOW OR RAIN. THIS WILL CONTINUE TO BE THE CASE UNTIL
LATE THIS EVENING WHEN THE DEFORMATION AXIS BEGINS TO SHIFT EAST
AS THE NORTHWEST FLOW KICKER PUSHES THE UPPER LOW INTO THE PLAINS.
THE BAND WILL SHIFT EAST LATE THIS EVENING INTO THE OVERNIGHT
HOURS BUT IT WILL ALSO WEAKEN SUBSTANTIAL WILL LITTLE IN THE WAY
OF ADDITION MEASURABLE PRECIPITATION AFTER MIDNIGHT ANYWHERE IN
THE FORECAST AREA.
SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER THE PLAINS. A
TORNADO WATCH IS IN EFFECT FOR MORRILL AND CHEYENNE COUNTY IN THE
SOUTHERN NEBRASKA PANHANDLE UNTIL 8 PM MDT. BASED ON RADAR TRENDS
AND CURRENT ATMOSPHERIC ENVIRONMENT...ANY TORNADO THREAT IS
RAPIDLY DECREASING. CURRENT SHOWER ACTIVITY WILL RAPIDLY
STABILIZE THE BOUNDARY LAYER. ALSO...LIMITED SHEAR IS ONLY
SUPPORTIVE OFF VERY SHORT LIVED AND WEAK TORNADIC ACTIVITY. WOULD
NOT BE SURPRISED TO SEE A FEW FUNNEL CLOUD REPORTS WITH
DEVELOPING SHOWERS AND THUNDERSTORMS AS THE OVERALL ENVIRONMENT IS
MORE SUPPORTIVE OF FUNNEL CLOUDS BUT THAT TOO WILL QUICKLY WANE
OVER THE NEXT FEW HOURS.
ANOTHER CONCERN FOR TONIGHT IS NORTHERN WINDS WHICH WILL RAMP UP
THIS EVENING INTO THE OVERNIGHT AS A COLD FRONT MOVES ACROSS THE
AREA. COULD SEE A SHORT PERIOD OF NASTY WINTER CONDITIONS...MAINLY
INTO THE SOUTHERN LARAMIE RANGE AND CHEYENNE AS THE SNOW BAND
SHIFTS EAST AND INTERACTS WITH STRONG GUSTY NORTHERN WINDS. NAM
AND GFS BUFKIT SOUNDINGS AROUND MIDNIGHT SHOWING 45 TO 50 KT
WINDS AT CHEYENNE NOT TOO FAR OFF THE SURFACE. VERY WELL COULD SEE
A 3 TO 4 HOUR PERIOD WITH LOW VISIBILITIES DUE TO FALLING SNOW AND
GUSTY WINDS. FORTUNATELY THIS WILL BE SHORT LIVED IF IT THIS
COMBINATIONS DOES INDEED OCCUR. ALSO WINDS SPEEDS WILL APPROACH
WIND ADVISORY LEVELS INTO THE NEBRASKA PANHANDLE LATER TONIGHT
AND INTO SUNDAY AFTERNOON. DID NOT ISSUE ANY WIND HEADLINES GIVEN
WINTER WEATHER AND CONVECTIVE HEADLINES...BUT A WIND ADVISORY MAY
BE NEEDED EVENTUALLY.
QUIETER WEATHER ACROSS THE AREA SUNDAY WITH THE UPPER LOW OUT OF
THE PICTURE. KEPT SOME LOW POPS GOING ACROSS THE WEST DURING THE
DAY SUNDAY...BUT IT IS LOOKING LESS AND LESS LIKELY FOR ANY
MEASURABLE PRECIPITATION FOR MOST OF SUNDAY. MAIN CHANCES WILL BE
WITH NORTHERN STREAM SHORTWAVE AND UPPER LEVEL JET ENERGY WHICH
SHOULD IMPACT THE SNOWY AND SIERRA MADRES SUNDAY NIGHT.
ACCUMULATIONS WILL BE MINIMAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 250 PM MDT SAT APR 18 2015
MEDIUM TO LONG RANGE MODELS IN FAIR AGREEMENT THROUGH THE MIDDLE
OF NEXT WEEK...WITH SOME DISAGREEMENT REGARDING THE TRACK AND
EVOLUTION OF A DEVELOPING LOW PRESSURE SYSTEM LIFTING NORTHEAST
ACROSS THE CENTRAL AND SOUTHERN ROCKY MOUNTAINS BY THURSDAY AND
FRIDAY. FOR EARLY NEXT WEEK...ALL MODELS SHOW NORTHWEST FLOW
INITIALLY WITH RELATIVELY DRY CONDITIONS LASTING INTO EARLY
WEDNESDAY. A WEAK SHORTWAVE TROUGH WILL PUSH ACROSS THE REGION
EMBEDDED IN THE NORTHWEST FLOW...BUT OUTSIDE OF SOME MOUNTAIN/HIGH
VALLEY RAIN AND SNOW SHOWERS...DO NOT EXPECT ANYTHING SIGNIFICANT
WITH HIGH TEMPERATURES ABOUT 10 TO 15 DEGREES COOLER THAN SEASONAL
AVERAGES. TEMPERATURES WILL FINALLY MODERATE SOME BY TUES AND
ESPECIALLY INTO WED...BACK INTO THE UPPER 50S TO UPPER 60S TO THE
EAST OF THE LARAMIE RANGE. A SURFACE HIGH WILL BUILD OVER THE
GREAT PLAINS LATE WEDNESDAY AND ON THURSDAY...RESULTING IN WINDS
VEERING INTO THE EAST AND SOUTHEAST. KEPT TSTORMS IN THE FORECAST
FOR THURSDAY WEST OF THE LARAMIE RANGE...BUT KEPT SHOWERS FURTHER
EAST DUE TO A PERSISTENT LLVL STRATUS DECK.
MODELS STRUGGLING WITH A SHORTWAVE DISTURBANCE LIFTING NORTHEAST
OUT OF ARIZONA THURSDAY NIGHT. 12Z GFS ATTEMPTS TO FORM A CLOSED
LOW ACROSS THE NORTH CENTRAL PLAINS OF COLORADO BY EARLY
FRIDAY...WITH PRECIP EXTENDING INTO THE I80 CORRIDOR OF SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THE ECMWF ON THE OTHER HAND IS MUCH
FURTHER SOUTH...MAINLY SHOWING THE FEATURE ACROSS NORTHERN NEW
MEXICO LIFTING NORTHEAST INTO KANSAS BY FRIDAY. KEPT A 20 TO 30
PERCENT CHANCE OF RAIN AND HIGH ELEVATION SNOW FOR FRIDAY AND EARLY
SATURDAY MORNING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH SUNDAY AFTERNOON)
A BAND OF SNOW AND RAIN WILL REMAIN OVER CONVERSE...CARBON...AND
ALBANY COUNTIES THIS EVENING...AND THEN WILL RAPIDLY PUSH
SOUTHEAST NEAR A COLD FRONT...WHICH WILL PUSH SOUTHWARD TONIGHT. SCATTERED
TSTORMS HAVE DEVELOPED NEAR KSNY AND JUST EAST OF KCYS THIS
AFTERNOON. THESE TSTORMS WILL GRADUALLY MOVE NORTHWEST THIS
AFTERNOON AND THIS EVENING. SMALL HAIL AND BRIEF HEAVY RAINFALL IS
EXPECTED. A MORE STABLE AIRMASS WILL PUSH INTO THE REGION ON
SUNDAY BEHIND A WEAK COLD FRONT...RESULTING IN LOW PRECIPITATION
CHANCES ACROSS MOST OF THE FORECAST AREA. HOWEVER...IT WILL BE
WINDY BEHIND THIS FRONT WITH NORTH WINDS BETWEEN 20 TO 30 KNOTS
EAST OF THE LARAMIE RANGE.
&&
.FIRE WEATHER...
ISSUED AT 250 PM MDT SAT APR 18 2015
SHOWERS AND THUNDERSTORMS WILL END ACROSS ACROSS THE PLAINS
TONIGHT WITH SNOW ENDING OVER HIGHER ELEVATIONS OF WYOMING AS THE
UPPER LEVEL DISTURBANCE SHIFTS EAST INTO THE CENTRAL PLAINS.
WARMING TREND THROUGH MID WEEK BUT GENERALLY ON THE COOLER SIDE
AND DRY. NEXT CHANCE FOR WIDESPREAD PRECIPITATION IS LATE NEXT
WEEK...MAYBE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 11 PM MDT THIS EVENING FOR WYZ110-114.
WINTER WEATHER ADVISORY UNTIL 11 PM MDT THIS EVENING FOR WYZ103-
105-112-113.
NE...NONE.
&&
$$
UPDATE...RJM
SHORT TERM...SML
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...SML
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1053 PM MDT THU APR 16 2015
.UPDATE...
ISSUED AT 539 PM MDT THU APR 16 2015
LATEST RADAR TRENDS SHOWING PRECIP FILLING IN OVER NORTEASTERN
COLORADO. LATEST INFRARED IMAGERY SHOWING RAPIDLY COOLING CLOUD
TOPS OVER SOUTHEASTERN COLORADO...MOVING DUE NORTH...SO OUR DRY
SLOT WE HAVE BEEN LOOKING AT LATE THIS AFTERNOON IS GETTING EDGED
EASTWARD. BOTH GFS AND NAM SOUNDINGS SHOWING FAVORABLE TEMPERATURE
PROFILES LATE THIS EVENING WITH SURFACE TEMPERATURES FALLING TO
BELOW FREEZING DURING THE BEST TIME OF LOW LEVEL MOISTURE
CONVERGENCE OVER THE SOUTH LARAMIE RANGE. VERY STRONG ISENTROPIC
LIFT OVER EXTREME SOUTHEAST WYOMING THIS EVENING FROM THE 300-310K
PRESSURE SURFACES. OPTED TO UPGRADE THE CURRENT WINTERWEATHER
ADVISORY WE HAVE GOING FOR CENTRAL LARAMIE COUNTY TO A WINTER
STORM WARNING AS WELL AS INCREASING SNOW AMOUNTS ACROSS THE WARNED
AREA AS ALL GUIDANCE POINTING TOWARDS OVER AN INCH OF STORM TOTAL
QPF WITH THIS EVENT. UPDATES HAVE BEEN SENT.
NEXT CONCERN DEALS WITH POSSIBILITY OF UPGRADING ADVISORIES
FURTHER NORTH ACROSS THE CENTRAL LARAMIE RANGE AND POSSIBLY PLATTE
COUNTY. CURRENT THINKING RIGHT NOW IS THE AXIS OF HEAVIEST PRECIP
WILL MOVE INTO THIS AREA TOMORROW AFTERNOON DURING DAYLIGHT
HOURS...SO MAYBE THERE WOULD BE A LITTLE MORE MELTING. DECIDED TO
LET THE NIGHT CREW TAKE ANOTHER LOOK AT THIS BEFORE ISSUING
ANYTHING.
&&
.SHORT TERM...(TONIGHT-SATURDAY NIGHT)
ISSUED AT 248 PM MDT THU APR 16 2015
FORECAST PROBLEMS WILL BE TEMPERATURES AND PRECIPITATION AMOUNTS
AND WHERE THE HEAVIER SNOWS WILL FALL OVER THE NEXT COUPLE DAYS.
UPPER LOW SPINNING OVER THE 4 CORNERS AREA SHOULD BEGIN A SLOW ENE
DRIFT ACROSS COLORADO LATER TONIGHT BEFORE LIKELY STALLING AGAIN
OVER COLORADO. PERIODIC DISTURBANCES ROTATING AROUND THIS LOW WILL
BRING SHOTS OF RAIN AND SNOW TO MOST OF THE CWA THROUGH SATURDAY
BEFORE A SHORTWAVE DROPS OUT OF SW CANADA AND PICKS UP THE
LOW...MOVING IT EAST INTO KANSAS AND DECREASING PCPN ACROSS THE
CWA. HIGHEST SNOWFALL WILL BE OVER THE LARAMIE RANGE AND THE
SNOWYS. ONE CONCERN IS CONVECTION CURRENTLY FIRING OVER KANSAS
WHICH COULD CUT MOISTURE AVAILABILITY IN THIS AREA AND REDUCE
SNOWFALL AMOUNTS. CURRENT WINTER STORM WARNING LOOKS IN GOOD SHAPE
REGARDLESS BUT FOR AREAS SUCH AS AROUND CHEYENNE SNOWFALL COULD
TURN OUT GREATER THAN CURRENTLY ANTICIPATED...WITH THE GREATEST
RISK BEING LATER TONIGHT INTO FRIDAY MORNING. WILL STAY WITH THE
WINTER WX ADVY BUT IT WONT TAKE MUCH TO UPGRADE IT.
TEMPERATURES TRICKY THROUGH FRIDAY ESPECIALLY ADJACENT TO THE LAR
RANGE WHERE EXPECTED WARMING TODAY DID NOT OCCUR DUE TO SOME COLD
AIR DAMMING. SFC WINDS LIKELY TO REMAIN NORTH TO NORTHEASTERLY
THUS WAA WILL BE LIMITED IF AT ALL IN THIS AREA. THUS EXPECT PCPN
TO REMAIN ALL SNOW THUS HAVE UPPED SNOWFALL AMOUNTS THERE. SHOULD
SEE IMPROVEMENT FRIDAY AFTERNOON OVER THE HIGH PLAINS WITH THE
NEXT EXPECTED LULL. PCPN SHOULD BECOME MORE SHOWERY IN NATURE
FRIDAY NIGHT AND SATURDAY WITH SNOW LEVEL RISING SLOWLY AS SOME
WARMING OCCURS.
.LONG TERM...(SUNDAY-WEDNESDAY)
ISSUED AT 248 PM MDT THU APR 16 2015
OUR PROBLEM CHILD UPPER-LOW WILL FINALLY LOOSEN ITS GRIP ON SUN AS A
STRONG KICKER SYSTEM DIVES SOUTHEAST ACROSS THE DAKOTAS. THE PATTERN
WILL REMAIN UNSETTLED THOUGH AS CYCLONIC MID LEVEL FLOW WILL REMAIN
INTACT OVER THE NORTHERN/CENTRAL ROCKIES. EXPECT INSTABILITY SHOWERS
TO CONTINUE FOR MOST OF THE CWA LATE IN THE WEEKEND. GFS/ECMWF SHOW
H7 TEMPS FALLING TO AROUND -8 TO -10 DEG C ON SUN AM BEHIND A STRONG
COLD FROPA...SO EXPECT THE PTYPE TO BE SNOW. THIS SHOULD NOT AMOUNT
TO MUCH OUTSIDE OF THE MOUNTAINS THOUGH. MOST MEDIUM RANGE GUIDANCE
SHOWS THE COOL/MOIST CYCLONIC FLOW PERSISTING THROUGH THE MIDDLE OF
NEXT WEEK...SO EXPECT CONTINUED DAILY CHANCES FOR RAIN/SNOW SHOWERS
WITH LITTLE OR NO ACCUMULATIONS. A WARMING TREND SHOULD BEGIN BY WED
AS RIDGING FINALLY TRANSLATES EASTWARD...ALLOWING H7 TEMPS TO CLIMB
BACK ABOVE FREEZING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1049 PM MDT THU APR 16 2015
HRRR GUIDANCE USED FOR THE 06Z TAFS. IFR.LIFR CONDITIONS INITIALLY
CONFINED TO KLAR AND KCYS WITH WRAP AROUND MOISTURE AND SNOW.
LATEST IR IMAGERY SHOWS COOLING CLOUD TOPS THAT INDICATES MOE
WIDESPREAD PRECIP LATER THIS MORNING. HRRR SHOWS IFR/LIFR
SPREADING EAST INTO THE SOUTHERN NEBRASKA PANHANDLE DURING THE
09-10Z TIMEFRAME AND CONTINUING THROUGH THE DAY FRIDAY. COULD
PERSIST THROUGH FRIDAY NIGHT.
&&
.FIRE WEATHER...
ISSUED AT 248 PM MDT THU APR 16 2015
MINIMAL CONCERNS SEEN THROUGH THE WEEKEND WITH GENEROUS RAIN AN/OR
SNOWS FALLING OVER MUCH OF THE AREA. TEMPERATURES WILL BE COOL TO
MILD WITH WEATHER CONDITIONS NON-CRITICAL.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL NOON MDT FRIDAY FOR WYZ114>118.
WINTER WEATHER ADVISORY UNTIL NOON MDT FRIDAY FOR WYZ103-105-106-
110-112.
NE...NONE.
&&
$$
UPDATE...GCC
SHORT TERM...RE
LONG TERM...CLH
AVIATION...GCC
FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1252 AM MDT SUN APR 19 2015
.UPDATE...
ISSUED AT 1250 AM MDT SUN APR 19 2015
UPDATED TO REMOVE EXPIRED WINTER WEATHER HEADLINES. SIGNIFICANT
SNOWFALL HAS ENDED IN THE NORTHERN AND CENTRAL MTS OF CO AND ONLY
LIGHT ADDITIONAL ACCUMULATIONS AREA EXPECTED.
UPDATE ISSUED AT 744 PM MDT SAT APR 18 2015
UPPER LOW CONTINUES TO ROTATE IN PLACE OVER THE EASTERN PLAINS
THIS EVENING. WRAP AROUND MOISTURE KEEPING SNOW GOING IN THE HIGH
COUNTRY...A MIXTURE ACROSS THE MESA AND PLATEAU REGION AND
THUNDERSTORMS ACROSS EASTERN UTAH. STEEP LAPSE RATES DUE TO
HEATING OUTSIDE OF THE THICKER CLOUD SHIELD IS AIDING THE WEAK
WAVE DROPPING THROUGH EASTERN UTAH. STORMS STARTED OUT QUITE
ROBUST WEST OF THE COLORADO RIVER...BUT AS THEY TRAVEL SOUTHEAST
ACROSS THE INSTABILITY GRADIENT...THEY WEAKEN OVER OUR CWA. WILL
LOSS OF HEATING EXPECT THE COVERAGE TO SLOWLY WANE OVER THE NEXT
HOUR OR SO. WILL BE WATCHING THE AFFECT OF NIGHTFALL ON EASTERN
PASSES AS MELTING HAS KEPT ROADS IN DECENT SHAPE. MAY KEEP SOME
OF THE HEADLINES ALONG DIVIDE IF NECESSARY PAST MIDNIGHT. LASTLY
DEW POINTS DID CREEP UP A BIT THIS AFTERNOON INTO THE 40S OVER THE
WESTERN VALLEYS. WILL BE MONITORING THE THREAT OF DENSE FOG
AS WELL.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 325 PM MDT SAT APR 18 2015
THE LOW PRESSURE RESPONSIBLE FOR THE MUCH NEEDED PRECIP OVER THE
LAST FEW DAYS IS NOW LOCATED OVER THE FRONT PLAINS WHILE CYCLONIC
FLOW CONTINUES TO PUMP IN MOISTURE FROM THE NORTH TO SOUTH. THIS
FLOW STARTS IN NERN WY AND THE PLUME REACHES AS FAR SOUTH AS THE
SAN JUANS. SNOW AND RAIN HAS FALLEN MUCH OF THE DAY UNDER THIS
PLUME OF MOISTURE AND WILL CONTINUE TO DO SO THROUGH THIS EVENING.
CURRENT WINTER HIGHLIGHTS LOOK GOOD SO NO CHANGES THERE. AN UPPER
LEVEL DISTURBANCE OVER SRN CANADA IS TRAILING A TROUGH THAT IS
CAUSING THE AREA OF LOW PRESSURE TO KEEP MOVING EWRD. THE REASON
THIS IS HAPPENING SO SLOWLY IS THE LACK OF ANY STRONG JET FEATURES
TO REALLY GET THIS SYSTEM MOVING. EVEN SO...THE CLOUD SHIELD/PLUME
WILL BRING MORE PRECIP TO THE AREA AS THE ATTENDANT LOW PRESSURE
MEANDERS EAST. BY MIDNIGHT...PRECIP WILL FAVOR THE NRN AND CENTRAL
MTNS ALONG WITH THE FLATTOPS DUE TO THEIR FAVORABLE LOCATION SO
ADDITIONAL ACCUMULATIONS STILL POSSIBLE UP THERE. THE REST OF THE
CWA MAY SEE AN ODD SHOWER OR TWO BUT NOTHING TOO SIGNIFICANT.
BY SUNDAY...THE CANADIAN LOW WILL BE JUST TO THE NORTH OF
MINNESOTA WHILE HIGH PRESSURE BUILDS INTO THE PACNW. THIS WILL
CAUSE OUR CWA TO BE SANDWICHED BETWEEN THESE TWO FEATURES. WEAK
PIECES OF ENERGY WILL DROP DOWN FROM THE NW POSSIBLY CAUSING SOME
PRECIP FOR THE CWA. THE GFS HIGHLIGHTING TWO DISTINCT WAVES...ONE
SUNDAY EVENING AND ANOTHER MONDAY MORNING. THE NAM12 ONLY SHOWING
SOME SPOTTY SHOWERS AT BEST WITH SOME CONVECTION THROWN IN. THE
HRRR AND RAP SHOWING MUCH LESS IN THE WAY OF PRECIP. THIS ALL
MEANS UNSETTLED WX WILL CONTINUE BUT WITH MUCH MORE DEFINITIVE
BREAKS BETWEEN DISTURBANCES. FORECAST BRINGS MOSTLY BENIGN
WEATHER SUNDAY WITH INCREASING CHANCES FOR PRECIP FROM
MIDAFTERNOON ONWARDS...MAINLY FAVORING THE CONTINENTAL DIVIDE.
TEMPS WILL WARM UP CONSIDERABLY TOMORROW THOUGH STILL REMAIN 5 TO
10 DEGREES BELOW NORMAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 325 PM MDT SAT APR 18 2015
UNSETTLED NW FLOW IS EXPECTED MONDAY AND TUESDAY. AN EMBEDDED WAVE
SHOULD FOCUS THE BEST CHANCE OF SHOWERS OVER THE NORTHERN AND
CENTRAL MOUNTAINS MONDAY AFTERNOON AND EVENING. DAYTIME INSTABILITY
WILL KEEP ISOLATED TO SCATTERED SHOWERS OVER THE MTNS ON TUESDAY.
TEMPORARY RIDGING DEVELOPS OVER THE AREA BY MIDWEEK AS A TROUGH
FORMS ALONG THE WEST COAST...WITH AN UPPER LOW OVER SRN CA BY THU
MORNING. ENOUGH RESIDUAL MOISTURE LINGERS FOR A FEW AFTERNOON
SHOWERS OR THUNDERSTORMS. FLOW ALOFT BECOMES SOUTHWEST...AND THE
SRN CA LIFTS ACROSS THE FOUR CORNERS/DESERT SOUTHWEST THU NIGHT
AND FRI MORNING. TIMING AND TRACK A BIT DIFFERENT BETWEEN MODELS
BUT STILL LOOKING LIKE A BETTER CHANCE OF PRECIPITATION WITH SOME
THUNDERSTORMS LATE NEXT WEEK. BOOSTED POPS FOR THU AFTERNOON
THROUGH FRI OVER THE BLENDED FORECAST GUIDANCE AS A RESULT.
GFS AND ECMWF SOLUTIONS CONTINUE TO DIVERGE ON SATURDAY. ECMWF MORE
AMPLIFIED AS IT DIGS A PAC NW TROUGH TO THE SRN GREAT BASIN BY
SATURDAY...RESULTING IN DOWNSTREAM RIDGING AND SW FLOW OVER OUR
AREA. GFS DROPS SOME ENERGY FROM THE PAC NW TROUGH DOWN THE WEST
COAST BUT SENDS MORE OF IT ACROSS THE NRN ROCKIES WITH WESTERLY
FLOW ACROSS UT/CO. WILL FOLLOW THE BLENDED GUIDANCE FOR SAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1040 PM MDT SAT APR 18 2015
A HIGH LATITUDE SYSTEM DIVING INTO THE NORTHERN PLAINS WILL BE
KICKING THIS STORM SYSTEM THAT HAS BEEN PARKED OVER COLORADO THE
PAST SEVERAL DAYS. THIS WILL ALLOW PRECIPITATION COVERAGE TO TREND
DOWNWARD OVER MOST OF WESTERN COLORADO AND EASTERN UTAH. THE HIGH
DIVIDE MOUNTAINS WILL THE MOST LIKELY AREA TO KEEP COLLECTING
LIGHT SNOW OVERNIGHT AND BE UNDER OBSCURATION. THE BIG CHALLENGE
INTO MID MORNING SUNDAY WILL BE LOW CLOUDS AND FOG DUE TO A MOIST
NEAR SURFACE LAYER FROM RECENT PRECIPITATION. THERE IS ALREADY A
HINT OF THIS AT KRIL...KASE AND KMTJ LATE THIS EVENING AS CLOUD
COVER ALOFT HAS THINNED. ANTICIPATE THIS WILL BECOME MORE OF A
WIDESPREAD PROBLEM THROUGH THE NIGHT BRINGING IFR/LIFR TO MANY
VALLEYS INCLUDING THE COLORADO TAF SITES. IMPROVEMENT SHOULD BE
QUICKER SUNDAY MORNING WITH MORE SUNSHINE AVAILABLE TO BURN OFF
THE LOW LEVEL MOISTURE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...CC
SHORT TERM...TGR
LONG TERM...JAD
AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1040 PM MDT SAT APR 18 2015
.UPDATE...
ISSUED AT 744 PM MDT SAT APR 18 2015
UPPER LOW CONTINUES TO ROTATE IN PLACE OVER THE EASTERN PLAINS
THIS EVENING. WRAP AROUND MOISTURE KEEPING SNOW GOING IN THE HIGH
COUNTRY...A MIXTURE ACROSS THE MESA AND PLATEAU REGION AND
THUNDERSTORMS ACROSS EASTERN UTAH. STEEP LAPSE RATES DUE TO
HEATING OUTSIDE OF THE THICKER CLOUD SHIELD IS AIDING THE WEAK
WAVE DROPPING THROUGH EASTERN UTAH. STORMS STARTED OUT QUITE
ROBUST WEST OF THE COLORADO RIVER...BUT AS THEY TRAVEL SOUTHEAST
ACROSS THE INSTABILITY GRADIENT...THEY WEAKEN OVER OUR CWA. WILL
LOSS OF HEATING EXPECT THE COVERAGE TO SLOWLY WANE OVER THE NEXT
HOUR OR SO. WILL BE WATCHING THE AFFECT OF NIGHTFALL ON EASTERN
PASSES AS MELTING HAS KEPT ROADS IN DECENT SHAPE. MAY KEEP SOME
OF THE HEADLINES ALONG DIVIDE IF NECESSARY PAST MIDNIGHT. LASTLY
DEW POINTS DID CREEP UP A BIT THIS AFTERNOON INTO THE 40S OVER THE
WESTERN VALLEYS. WILL BE MONITORING THE THREAT OF DENSE FOG
AS WELL.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 325 PM MDT SAT APR 18 2015
THE LOW PRESSURE RESPONSIBLE FOR THE MUCH NEEDED PRECIP OVER THE
LAST FEW DAYS IS NOW LOCATED OVER THE FRONT PLAINS WHILE CYCLONIC
FLOW CONTINUES TO PUMP IN MOISTURE FROM THE NORTH TO SOUTH. THIS
FLOW STARTS IN NERN WY AND THE PLUME REACHES AS FAR SOUTH AS THE
SAN JUANS. SNOW AND RAIN HAS FALLEN MUCH OF THE DAY UNDER THIS
PLUME OF MOISTURE AND WILL CONTINUE TO DO SO THROUGH THIS EVENING.
CURRENT WINTER HIGHLIGHTS LOOK GOOD SO NO CHANGES THERE. AN UPPER
LEVEL DISTURBANCE OVER SRN CANADA IS TRAILING A TROUGH THAT IS
CAUSING THE AREA OF LOW PRESSURE TO KEEP MOVING EWRD. THE REASON
THIS IS HAPPENING SO SLOWLY IS THE LACK OF ANY STRONG JET FEATURES
TO REALLY GET THIS SYSTEM MOVING. EVEN SO...THE CLOUD SHIELD/PLUME
WILL BRING MORE PRECIP TO THE AREA AS THE ATTENDANT LOW PRESSURE
MEANDERS EAST. BY MIDNIGHT...PRECIP WILL FAVOR THE NRN AND CENTRAL
MTNS ALONG WITH THE FLATTOPS DUE TO THEIR FAVORABLE LOCATION SO
ADDITIONAL ACCUMULATIONS STILL POSSIBLE UP THERE. THE REST OF THE
CWA MAY SEE AN ODD SHOWER OR TWO BUT NOTHING TOO SIGNIFICANT.
BY SUNDAY...THE CANADIAN LOW WILL BE JUST TO THE NORTH OF
MINNESOTA WHILE HIGH PRESSURE BUILDS INTO THE PACNW. THIS WILL
CAUSE OUR CWA TO BE SANDWICHED BETWEEN THESE TWO FEATURES. WEAK
PIECES OF ENERGY WILL DROP DOWN FROM THE NW POSSIBLY CAUSING SOME
PRECIP FOR THE CWA. THE GFS HIGHLIGHTING TWO DISTINCT WAVES...ONE
SUNDAY EVENING AND ANOTHER MONDAY MORNING. THE NAM12 ONLY SHOWING
SOME SPOTTY SHOWERS AT BEST WITH SOME CONVECTION THROWN IN. THE
HRRR AND RAP SHOWING MUCH LESS IN THE WAY OF PRECIP. THIS ALL
MEANS UNSETTLED WX WILL CONTINUE BUT WITH MUCH MORE DEFINITIVE
BREAKS BETWEEN DISTURBANCES. FORECAST BRINGS MOSTLY BENIGN
WEATHER SUNDAY WITH INCREASING CHANCES FOR PRECIP FROM
MIDAFTERNOON ONWARDS...MAINLY FAVORING THE CONTINENTAL DIVIDE.
TEMPS WILL WARM UP CONSIDERABLY TOMORROW THOUGH STILL REMAIN 5 TO
10 DEGREES BELOW NORMAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 325 PM MDT SAT APR 18 2015
UNSETTLED NW FLOW IS EXPECTED MONDAY AND TUESDAY. AN EMBEDDED WAVE
SHOULD FOCUS THE BEST CHANCE OF SHOWERS OVER THE NORTHERN AND
CENTRAL MOUNTAINS MONDAY AFTERNOON AND EVENING. DAYTIME INSTABILITY
WILL KEEP ISOLATED TO SCATTERED SHOWERS OVER THE MTNS ON TUESDAY.
TEMPORARY RIDGING DEVELOPS OVER THE AREA BY MIDWEEK AS A TROUGH
FORMS ALONG THE WEST COAST...WITH AN UPPER LOW OVER SRN CA BY THU
MORNING. ENOUGH RESIDUAL MOISTURE LINGERS FOR A FEW AFTERNOON
SHOWERS OR THUNDERSTORMS. FLOW ALOFT BECOMES SOUTHWEST...AND THE
SRN CA LIFTS ACROSS THE FOUR CORNERS/DESERT SOUTHWEST THU NIGHT
AND FRI MORNING. TIMING AND TRACK A BIT DIFFERENT BETWEEN MODELS
BUT STILL LOOKING LIKE A BETTER CHANCE OF PRECIPITATION WITH SOME
THUNDERSTORMS LATE NEXT WEEK. BOOSTED POPS FOR THU AFTERNOON
THROUGH FRI OVER THE BLENDED FORECAST GUIDANCE AS A RESULT.
GFS AND ECMWF SOLUTIONS CONTINUE TO DIVERGE ON SATURDAY. ECMWF MORE
AMPLIFIED AS IT DIGS A PAC NW TROUGH TO THE SRN GREAT BASIN BY
SATURDAY...RESULTING IN DOWNSTREAM RIDGING AND SW FLOW OVER OUR
AREA. GFS DROPS SOME ENERGY FROM THE PAC NW TROUGH DOWN THE WEST
COAST BUT SENDS MORE OF IT ACROSS THE NRN ROCKIES WITH WESTERLY
FLOW ACROSS UT/CO. WILL FOLLOW THE BLENDED GUIDANCE FOR SAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1040 PM MDT SAT APR 18 2015
A HIGH LATITUDE SYSTEM DIVING INTO THE NORTHERN PLAINS WILL BE
KICKING THIS STORM SYSTEM THAT HAS BEEN PARKED OVER COLORADO THE
PAST SEVERAL DAYS. THIS WILL ALLOW PRECIPITATION COVERAGE TO TREND
DOWNWARD OVER MOST OF WESTERN COLORADO AND EASTERN UTAH. THE HIGH
DIVIDE MOUNTAINS WILL THE MOST LIKELY AREA TO KEEP COLLECTING
LIGHT SNOW OVERNIGHT AND BE UNDER OBSCURATION. THE BIG CHALLENGE
INTO MID MORNING SUNDAY WILL BE LOW CLOUDS AND FOG DUE TO A MOIST
NEAR SURFACE LAYER FROM RECENT PRECIPITATION. THERE IS ALREADY A
HINT OF THIS AT KRIL...KASE AND KMTJ LATE THIS EVENING AS CLOUD
COVER ALOFT HAS THINNED. ANTICIPATE THIS WILL BECOME MORE OF A
WIDESPREAD PROBLEM THROUGH THE NIGHT BRINGING IFR/LIFR TO MANY
VALLEYS INCLUDING THE COLORADO TAF SITES. IMPROVEMENT SHOULD BE
QUICKER SUNDAY MORNING WITH MORE SUNSHINE AVAILABLE TO BURN OFF
THE LOW LEVEL MOISTURE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT FOR COZ009-010-
012-017-018.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ003-
004-013.
UT...NONE.
&&
$$
UPDATE...15
SHORT TERM...TGR
LONG TERM...JAD
AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
420 AM CDT SUN APR 19 2015
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* EAST WINDS ARND 6 TO 10 KT...OCCASIONAL GUSTS TO 17KT.
* WINDS TURN NORTH LATE TONIGHT...THEN NORTHWEST EARLY MON.
* RAIN OVERSPREAD TAF SITES LATE THIS AFTN THRU TONIGHT.
* POSSIBLE LOW END MVFR CIGS OR PATCHY IFR CIGS DEVELOPING.
BEACHLER
//DISCUSSION...UPDATED 06Z...
WITH THE DEPARTING HIGH PRESSURE TO THE EAST...MID-LVL MOISTURE
WAS SLOWLY LIFTING NORTH ACROSS THE NORTHERN IL/NORTHWEST IN
AIRFIELDS. THIS HAS ALLOWED A CIRRUS CLOUD DECK TO THICKEN...AND
ADDITIONAL MOISTURE IS EXPECTED TO LIFT NORTHEAST AS A LOW
PRESSURE SYSTEM NEARS THE REGION LATER TONIGHT INTO EARLY MON.
GUIDANCE HAS BEEN SLOWLY TRENDING LATER WITH THE ARRIVAL OF PRECIP
UNTIL AFT 18Z...AND MAY NOT BE CLOSER TO 23Z. WILL CONTINUE TO
MENTION VCSH BUT PUSH IT TO 20Z...THEN EXPECT THE COVERAGE TO
INCREASE IN PRECIP CLOSER TO 23Z. WITH THE STEADILY THICKEN AND
LOWER CLOUDS...THE CHALLENGE IS ALSO ON WIND SPEEDS. IT IS STILL
POSSIBLE GUSTS WILL NEED TO BE PUT BACK INTO THE TAF...ALTHOUGH
WITH THE ABUNDANT CLOUD COVER...IT IS QUESTIONABLE HOW FREQUENT
GUSTS WILL OCCUR AT THE TAF SITES. SO HAVE REMOVED THE MENTION AT
THIS TIME AND JUST INCREASED THE SUSTAINED WINDS. THEN AT SOME
POINT LATE THIS EVENING CIGS ARE EXPECTED TO QUICKLY DIP TO MVFR
AND POSSIBLY TO IFR CONDS. PRECIP COVERAGE WILL BEGIN TO DIMINISH
EARLY MON...AND MAY TREND TOWARDS PATCHY DRIZZLE WHICH MAY ALSO
FURTHER LOWER CIGS AND VSBYS EARLY MON MORNING.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH CONFIDENCE IN ALL ELEMENTS THROUGH 18Z...MEDIUM CONFIDENCE
IN WIND DIR/SPEED AFT 18Z.
* MEDIUM CONFIDENCE IN PRECIP TIMING/COVERAGE.
* HIGH CONFIDENCE IN CIGS DIMINISHING TO AT LEAST MVFR CONDS AFT
21Z...AND MEDIUM CONFIDENCE IN CIGS BECOMING IFR AFT 3Z MON.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...CHANCE OF SHRA/MVFR. GUSTY WEST-NORTHWESTERLY WINDS.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
KJB
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
344 AM CDT SUN APR 19 2015
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* EAST WINDS ARND 6 TO 10 KT...OCCASIONAL GUSTS TO 17KT.
* WINDS TURN NORTH LATE TONIGHT...THEN NORTHWEST EARLY MON.
* RAIN OVERSPREAD TAF SITES LATE THIS AFTN THRU TONIGHT.
* POSSIBLE LOW END MVFR CIGS OR PATCHY IFR CIGS DEVELOPING.
BEACHLER
//DISCUSSION...UPDATED 06Z...
WITH THE DEPARTING HIGH PRESSURE TO THE EAST...MID-LVL MOISTURE
WAS SLOWLY LIFTING NORTH ACROSS THE NORTHERN IL/NORTHWEST IN
AIRFIELDS. THIS HAS ALLOWED A CIRRUS CLOUD DECK TO THICKEN...AND
ADDITIONAL MOISTURE IS EXPECTED TO LIFT NORTHEAST AS A LOW
PRESSURE SYSTEM NEARS THE REGION LATER TONIGHT INTO EARLY MON.
GUIDANCE HAS BEEN SLOWLY TRENDING LATER WITH THE ARRIVAL OF PRECIP
UNTIL AFT 18Z...AND MAY NOT BE CLOSER TO 23Z. WILL CONTINUE TO
MENTION VCSH BUT PUSH IT TO 20Z...THEN EXPECT THE COVERAGE TO
INCREASE IN PRECIP CLOSER TO 23Z. WITH THE STEADILY THICKEN AND
LOWER CLOUDS...THE CHALLENGE IS ALSO ON WIND SPEEDS. IT IS STILL
POSSIBLE GUSTS WILL NEED TO BE PUT BACK INTO THE TAF...ALTHOUGH
WITH THE ABUNDANT CLOUD COVER...IT IS QUESTIONABLE HOW FREQUENT
GUSTS WILL OCCUR AT THE TAF SITES. SO HAVE REMOVED THE MENTION AT
THIS TIME AND JUST INCREASED THE SUSTAINED WINDS. THEN AT SOME
POINT LATE THIS EVENING CIGS ARE EXPECTED TO QUICKLY DIP TO MVFR
AND POSSIBLY TO IFR CONDS. PRECIP COVERAGE WILL BEGIN TO DIMINISH
EARLY MON...AND MAY TREND TOWARDS PATCHY DRIZZLE WHICH MAY ALSO
FURTHER LOWER CIGS AND VSBYS EARLY MON MORNING.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN ALL ELEMENTS THROUGH 18Z...MEDIUM CONFIDENCE
IN WIND DIR/SPEED AFT 18Z.
* MEDIUM CONFIDENCE IN PRECIP TIMING/COVERAGE.
* HIGH CONFIDENCE IN CIGS DIMINISHING TO AT LEAST MVFR CONDS AFT
21Z...AND MEDIUM CONFIDENCE IN CIGS BECOMING IFR AFT 3Z MON.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...CHANCE OF SHRA/MVFR. GUSTY WEST-NORTHWESTERLY WINDS.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
KJB
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
328 AM CDT SUN APR 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT SUN APR 19 2015
LATEST WATER VAPOR IMAGERY CONTINUES TO SHOW CLOSED UPPER LOW OVER
EASTERN COLORADO, WITH LEAD SHORT-WAVE ROTATING AROUND THIS FEATURE
ACROSS ARKANSAS/LOUISIANA. AS THIS WAVE LIFTS NORTHWARD, PRECIP
WILL EVENTUALLY SPREAD INTO CENTRAL ILLINOIS TODAY. 07Z/2AM RADAR
MOSAIC SHOWS DRY CONDITIONS ACROSS THE ENTIRE KILX CWA: HOWEVER,
SHOWERS ARE BEGINNING TO DEVELOP AND BECOME MORE WIDESPREAD FURTHER
SOUTH ACROSS WESTERN KENTUCKY AND FAR SOUTHERN ILLINOIS. BASED ON
RADAR TIMING TOOLS AND LATEST HRRR FORECAST, THINK SCATTERED SHOWERS
WILL ARRIVE SOUTH OF I-70 OVER THE NEXT COUPLE OF HOURS, THEN WILL
SPREAD NORTHWARD TOWARD THE I-74 CORRIDOR BY MIDDAY. HAVE ADJUSTED
POPS TO ACCOUNT FOR THE SLOWER ARRIVAL OF PRECIP DURING THE MORNING,
THEN HAVE GONE WITH CATEGORICAL POPS ACROSS THE BOARD THIS
AFTERNOON. ASIDE FROM SOME SBCAPES OF AROUND 1000J/KG ACROSS THE
FAR SE CWA, FORECAST SOUNDINGS REMAIN FAIRLY STABLE TODAY. AS A
RESULT, AM EXPECTING MAINLY SHOWERS WITH JUST A FEW EMBEDDED
THUNDERSTORMS. DUE TO CLOUD COVER AND PRECIP, HIGH TEMPERATURES
WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS, WITH READINGS
MAINLY IN THE 60S. WARMEST TEMPS OF AROUND 70 WILL BE FOCUSED
ALONG/WEST OF THE ILLINOIS RIVER WHERE PRECIP WILL BE SLOWEST TO
ARRIVE.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 328 AM CDT SUN APR 19 2015
LEAD SHORT-WAVE WILL LIFT INTO NORTHERN ILLINOIS/INDIANA BY EARLY
EVENING, LIKELY LEADING TO A TEMPORARY LULL IN THE SHOWERS.
MEANWHILE, THE MAIN UPPER LOW WILL GET A SOLID PUSH EASTWARD AND
WILL ARRIVE ACROSS ILLINOIS LATER TONIGHT INTO MONDAY MORNING.
SHOWERS AND PERHAPS A THUNDERSTORM WILL ACCOMPANY THIS FEATURE, SO
WILL CONTINUE LIKELY POPS TONIGHT THROUGH MONDAY MORNING. ONCE THE
500MB VORT MAX AND THE ASSOCIATED SURFACE COLD FRONT PASS TO THE
EAST, RAIN CHANCES WILL COME TO AN END BY MONDAY AFTERNOON. THANKS
TO A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT, STRONG W/NW
WINDS GUSTING TO BETWEEN 25 AND 30 MPH WILL DEVELOP ON MONDAY. THE
WINDS WILL SUBSIDE FOR A TIME MONDAY NIGHT, BUT WILL ONCE AGAIN
INCREASE MARKEDLY DURING THE DAY TUESDAY. HIGH TEMPERATURES BOTH
DAYS WILL REMAIN IN THE LOWER 60S, WHILE OVERNIGHT LOWS DIP INTO THE
UPPER 30S AND LOWER 40S.
00Z APR 19 MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING
THE EXTENDED FORECAST, WITH CONSENSUS FEATURING A CHILLY AND LARGELY
DRY WEEK AHEAD. BOTH THE GFS AND ECMWF INDICATE A WEAK COLD FRONT
WILL PASS THROUGH CENTRAL ILLINOIS TUESDAY NIGHT INTO WEDNESDAY:
HOWEVER, THEY DISAGREE ON HOW MUCH PRECIP IT WILL GENERATE. THE GFS
IS SLIGHTLY WETTER AND FASTER WITH FROPA, WHILE THE ECMWF IS DRIER
AND ABOUT 6 HOURS SLOWER WITH THE FRONT. DUE TO THE STRONG
NORTHWESTERLY UPPER FLOW PATTERN IN PLACE ACROSS THE MIDWEST, THINK
THE FASTER GFS IS THE WAY TO GO WITH TIMING, BUT THINK THE DRIER
ECMWF IS BETTER WITH QPF AS DEEP MOISTURE WILL BE LACKING WITH THIS
FEATURE. AS A RESULT, HAVE OPTED TO CARRY LOW CHANCE POPS
EVERYWHERE TUESDAY NIGHT, THEN ONLY ACROSS THE SE CWA ON WEDNESDAY.
ONCE THE FRONT PASSES, A COOL/CANADIAN AIRMASS WILL SETTLE INTO THE
REGION FOR THE MIDDLE AND END OF THE WEEK. HIGH TEMPERATURES WILL
STRUGGLE TO REACH THE 60 DEGREE MARK ON BOTH WEDNESDAY AND THURSDAY,
WHILE LOWS DROP INTO THE 30S. COLDEST MORNING MAY END UP BEING
FRIDAY MORNING, WHEN RIDGE OF HIGH PRESSURE IS OVERHEAD AND WINDS
WILL BE LIGHTEST. WILL NEED TO KEEP AN EYE ON TEMPS, AS FROST
ADVISORIES WILL BE POSSIBLE ACROSS PARTS OF CENTRAL/SOUTHEAST
ILLINOIS LATER THIS WEEK. AFTER THAT, ANOTHER SYSTEM WILL APPROACH
FROM THE SOUTHWEST BY THE END OF THE WEEK: HOWEVER, ITS INFLUENCE
LIKELY WILL NOT BE FELT UNTIL FRIDAY NIGHT/SATURDAY AT THE EARLIEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1145 PM CDT SAT APR 18 2015
VFR CONDITIONS CONTINUE ACROSS CENTRAL IL TAF SITES THIS EVENING
AS A COMPLEX PATTERN OF A LARGE SCALE CENTRAL U.S. TROUGH WITH
MULTIPLE EMBEDDED DISTURBANCES DEVELOPS. MAINLY VFR CONDITIONS
EXPECTED UNTIL AROUND 12Z WHEN THE FIRST EMBEDDED DISTURBANCE
LIFTS NORTHEASTWARD INTO SE ILLINOIS. EXPECT INCREASING
PRECIPITATION AT SOUTHERN TERMINALS KSPI-KDEC AROUND 10Z SPREADING
NORTH TO KPIA-KBMI-KCMI AROUND 12Z. BY 14-16Z...PREDOMINANT RAIN
WITH MVFR CIGS/VSBYS LIKELY AND INCLUDED IN TAFS. ISOLATED
THUNDERSTORMS POSSIBLE AS WELL...BUT LIKELIHOOD/TIMING NOT HIGH
ENOUGH FOR EXPLICIT MENTION THIS FAR OUT. BRIEFLY IMPROVING
CONDITIONS LATE AFTERNOON EARLY EVENING AS FIRST DISTURBANCE MOVES
OUT OF CENTRAL IL...BUT TRAILING WAVE/COLD FRONT EXPECTED TO
INITIATE ADDITIONAL SHOWERS/THUNDERSTORMS TOWARD 06Z. WITH A
NARROW WINDOW OF UNCERTAIN IMPROVEMENT...KEPT MVFR CIGS/VSBYS
THROUGH 06Z. WINDS E-NE5-10 KTS THROUGH 15Z BECOMING VARIABLE-
NNW DURING AFTERNOON AS LOW LIFTS TO THE NE OF CENTRAL IL AREA.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1205 AM CDT SUN APR 19 2015
.DISCUSSION...
FOR THE 06Z TAF PACKAGE.
&&
.AVIATION...
AS ANTICIPATED...VISIBILITY RESTRICTIONS HAVE BEGUN TO DEVELOP
ACROSS THE AREA...AND CONVECTIVE COMPLEX APPROACHING FROM THE
NORTHWEST IS STARTING TO DECAY. TIMED THE REMNANTS OF THIS FEATURE
INTO KBPT...KLCH...AND KAEX AS JUST A BRIEF PERIOD OF INCREASED
WINDS AND LIGHT RAIN. NO EFFECTS CARRIED AT THE ACADIANA
TERMINALS. EXPECT THAT THE RESULTANT MIXING WILL IMPROVE THE
VISIBILITY...AT LEAST TEMPORARILY...BUT DID SHOW THE FOG RE-
DEVELOPING A COUPLE HOURS LATER. VFR TO PREVAIL TOMORROW ONCE THE
FOG ERODES.
13
&&
.PREV DISCUSSION... /ISSUED 925 PM CDT SAT APR 18 2015/
DISCUSSION...
MAIN WX CONCERN IS THE MCS OVER C AND N TX...MOVING E. RADAR STILL
SHOWS FAIRLY SOLID SQUALL LINE BETWEEN WHILE SOME WEAKENING IS
EXPECTED TO CONTINUE...LATEST NAM12 & HRRR SUGGEST IT CONTINUING E
THE NEXT SEVERAL HOURS...AFFECTING INLAND SE TX/C LA BETWEEN
06-09Z. THUS...HAVE INCREASED THE POPS AND QPF ACROSS THESE AREAS
FOR THE EVENING UPDATE. FOR THE REMAINDER OF THE AREA...20%
CONTINUES FOR ANY ISO SHRA/TSRA AHEAD OF THIS SYSTEM.
DML
PREV DISCUSSION... /ISSUED 734 PM CDT SAT APR 18 2015/
DISCUSSION...
FOR THE 00Z TAF PACKAGE.
AVIATION...
MAINLY ISOLATED TO SCATTERED SHOWERS ACROSS PARTS OF EAST AND
SOUTH CENTRAL LOUISIANA EARLY THIS EVENING. LATEST HRRR DEPICTS
CONVECTIVE COMPLEX OVER CENTRAL TEXAS REACHING PERHAPS AS FAR AS JUST
EAST OF THE SABINE RIVER SOMETIME AFTER MIDNIGHT BEFORE
DISSIPATING. WILL CONTINUE TO MONITOR RADAR/MODEL TRENDS THROUGH
THE EVENING. OTHERWISE...A MIX OF MVFR/VFR CIGS ACROSS THE AREA IS
EXPECTED TO LOWER INTO MVFR/IFR AS LIGHT FOG AND/OR LOWER CIGS
DEVELOP DURING THE OVERNIGHT HOURS. IMPROVEMENT TO VFR IS EXPECTED
ON SUNDAY AS DRIER AIR MOVES IN FROM THE WEST.
13
PREV DISCUSSION... /ISSUED 421 PM CDT SAT APR 18 2015/
SYNOPSIS...
LATEST UA ANALYSIS AND WV IMAGERY SHOWS SLOW-MOVING UPR LOW OVER
ERN COLORADO...WITH MOIST SWLY FLOW CONTINUING TO STREAM OVER THE
REGION. ONE IMPULSE ASSOCIATED WITH THIS SYSTEM WAS MOVING ACRS
SRN TX INTO THE WRN GULF...WITH A SECOND IMPULSE CROSSING WRN TX.
THESE TWO SYSTEMS WERE TRIGGERING STORMS ACRS THE NW/CNTL GULF
COAST AS WELL AS ACRS WRN TX. OVER THE IMMEDIATE CWA...ACTIVITY
HAS REMAINED FAIRLY SCTD...WITH A SWATH OF LT/MODT RAIN OVER THE
COASTAL WATERS...AND SCT SHRA/TSRA ACRS CNTL/WRN LA.
DISCUSSION...
OVERNIGHT CONVECTIVE COMPLEX ALLOWED THE AIRMASS TO STABILIZE
TODAY...AND ONGOING CONVECTION OVER THE GULF HAS LIMITED INFLOW.
THIS COMBINATION HAS REDUCED THE POTENTIAL FOR HEAVY RAIN AND
WIDESPREAD ACTIVITY TODAY AND LIKELY INTO TONIGHT. LOOKING AT A
COMBINATION OF RECENT HRRR RUNS AS WELL AS RAP/NAM GUIDANCE SHOWS
A DECREASING TREND DURING THE EVENING AND OVERNIGHT. ACTIVITY
ALONG THE TX COAST IS EXPECTED TO TREK E/NE BUT GRADUALLY WEAKEN
AS IT APPROACHES OUR COASTAL WATERS ZONES. LIKEWISE...THE STORMS
ACRS WRN TX WILL MOVE EAST THIS EVENING...BUT ALSO WEAKEN AS THEY
REACH THE AREA LATER TONIGHT. QPF VALUES ARE EXPECTED TO REMAIN
BELOW AN INCH THROUGH SUNDAY...AND WITH THIS IN MIND...HAVE GONE
AHEAD AND CANCELLED THE FLASH FLOOD WATCH.
DRIER MID LVL AIR WILL BEGIN TO PUSH EAST OVER THE AREA ON
SUNDAY...HELPING TO BRING A REPREIVE FROM THE RAINY PATTERN.
HOWEVER...ENOUGH MOISTURE WILL LINGER TO ALLOW FOR AT LEAST A SLT
CHC FOR A FEW SHOWERS OR TSTMS. BY SUNDAY NIGHT...A COOL FRONT
WILL MOVE THROUGH THE REGION. ENOUGH CONVERGENCE AND LIFT ARE
EXPECTED ALONG THE FRONTAL BOUNDARY TO PRODUCE A SCT BAND OF
SHOWERS AND TSTMS AS IT CROSSES THE AREA. SPC DOES HAVE THE AREA
OUTLINED IN A SLT RISK FOR SUNDAY/SUNDAY NIGHT AS INSTABILITY
LOOKS TO INCREASE AHEAD OF THE BOUNDARY. THUS AN ISOLATED STRONG
TO SEVERE STORM CANNOT BE RULED OUT ESPECIALLY ACRS THE NRN TIER
OF COUNTIES AND PARISHES.
DRY WEATHER FINALLY RETURNS ON MONDAY AND SHOULD CONTINUE INTO
TUESDAY AS HIGH PRES BUILDS INTO THE AREA. SMALL RAIN CHCS WILL
RETURN BY MIDWEEK WITH CHCS INCREASING TOWARD THE LATTER PART OF
THE WEEK. ZONAL FLOW WILL PREVAIL THROUGH THE WEEK AND LIFT
ASSOCIATED WITH EMBEDDED DISTURBANCES WILL KEEP AT LEAST CHC POPS
OVER THE AREA THURSDAY AND FRIDAY.
MARINE...
LT TO MDT SWLY FLOW WILL CONTINUE THROUGH SUNDAY WITH SHOWERS AND
TSTMS GRADUALLY DIMINISHING. A COOL FRONT WILL CROSS THE COASTAL
WATERS LATE SUNDAY NIGHT...WITH MODT OFFSHORE FLOW DEVELOPING
FOR MONDAY. EXERCISE CAUTION CONDITIONS COULD BE POSSIBLE AT TIMES
MONDAY INTO TUESDAY. WINDS WILL GRADUALLY VEER ELY TUESDAY...THEN
SELY BY WEDNESDAY AS SFC HIGH PRES MOVES EAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 63 83 60 76 / 30 30 30 10
LCH 64 82 63 79 / 20 20 20 10
LFT 65 84 64 79 / 30 20 20 10
BPT 64 82 63 79 / 20 20 20 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DULUTH MN
342 AM CDT SUN APR 19 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
THE FOCUS REMAINS ON THE RAIN TODAY AND TONIGHT. REFINED THE PCPN
CHANCES BY USING A BLEND OF THE RAP13 AND HRRR MODEL RUNS THROUGH
THIS MORNING SINCE THE TWO MODELS SEEM TO BE DOING PRETTY WELL
CAPTURING THE LOCATION OF THE CURRENT RAIN. DID NOT MAKE ANY
DRAMATIC CHANGES TO RAINFALL. OVERALL...MUCH OF THE FORECAST AREA
CAN EXPECT ABOUT 0.30 TO 0.75 INCHES OF RAINFALL THROUGH TONIGHT.
AT 330 AM...AN AREA OF LOW PRESSURE WAS OVER THE BORDER BETWEEN
SOUTH DAKOTA AND SW MINNESOTA. A FRONTAL BOUNDARY EXTENDED
NORTHWARD TO ANOTHER AREA OF LOW PRESSURE IN SOUTHERN MANITOBA.
THERE WAS AN UPPER LEVEL TROUGH OVER THE NORTHERN HIGH PLAINS AND
SASKATCHEWAN/MANITOBA DIGGING AND DEEPENING TOWARDS THE NORTHERN
PLAINS AND ONTARIO. A LARGE AREA OF RAIN WAS LIFTING TO NNE
THROUGH THE SOUTHERN TWO THIRDS OF THE FORECAST AREA. THIS RAIN
WAS ASSOCIATED WITH A BAND OF MID LEVEL FRONTOGENESIS AHEAD OF THE
LOW NEAR THE SD/MN BORDER. THERE WAS ADDITIONAL RAIN IN EASTERN
SOUTH DAKOTA AND NW MINNESOTA MOVING TO THE EAST IN THE WAKE OF
THE TROUGH BOUNDARY AND AHEAD OF THE UPPER LEVEL TO THE WEST. THE
NORTHLAND HAD CLOUDY SKIES WITH TEMPERATURES IN THE UPPER 30S TO
MIDDLE 40S. THE NORTHLAND HAD LIGHT EASTERLY TO SOUTHEASTERLY
WINDS.
THIS MORNING...THE SURFACE LOW NEAR THE SD/MN BORDER WILL LIFT NE
TO THE AITKIN AREA BY THIS AFTERNOON. THE SURFACE LOW IN SOUTHERN
MANITOBA WILL DIG TO THE SE. THE RAIN OVER THE FORECAST AREA EARLY
THIS MORNING WILL CONTINUE LIFTING TO THE NORTH WITH THE BAND OF
MID LEVEL FRONTOGENESIS. PARTS OF THE NORTHERN FORECAST COULD PICK
UP TO AROUND A HALF INCH OF RAIN THROUGH THIS MORNING. THE COLD
FRONT IN NORTH DAKOTA WILL BEGIN TO MOVE INTO THE WESTERN FORECAST
AREA LATE THIS MORNING.
THIS AFTERNOON AND EVENING...THE TWO LOWS WILL GRADUALLY MERGE
INTO ONE LOW OVER NW ONTARIO. CLOUDY AND COOL WEATHER IS EXPECTED
WITH HIGHS RANGING FROM THE UPPER 40S OVER THE NORTH TO THE 50S
OVER THE SOUTH. MOST OF THE AFTERNOON AND EVENING RAIN WILL BE
OVER THE EASTERN FORECAST AREA AHEAD OF THE EASTWARD ADVANCING
COLD FRONT. A DRY SLOT WILL MOVE INTO THE WESTERN FORECAST
AREA...AND THERE COULD BE PARTIAL CLEARING IN THE SW FORECAST
AREA. ALSO...A PROMINENT BAND OF LOW/MID LEVEL FRONTOGENESIS WILL
SET UP OVER NW WISCONSIN THIS EVENING WHICH DEVELOP AND INTENSIFY
A BAND OF RAIN OVER THAT AREA. THE UPPER LEVEL TROUGH OVER THE
NORTHERN PLAINS AND SOUTH CENTRAL CANADA WILL DEEPEN AND DEVELOP
INTO A WELL DEFINED UPPER LEVEL OVER SOUTHERN MANITOBA THIS
AFTERNOON AND CONTINUE DEEPENING AS IT APPROACHES NORTHERN
MANITOBA.
LATER TONIGHT AND EARLY MONDAY...THE COLD FRONT WILL FINISH
MOVING THROUGH THE FORECAST AREA. THE UPPER LEVEL LOW WILL
CONTINUE DEEPENING OVER NW ONTARIO. THE LOW/MID LEVEL
FRONTOGENETICAL BAND IN NW WISCONSIN SHOULD EXIT TO THE EAST BY
AROUND DAWN. TEMPERATURES WILL DROP INTO THE MIDDLE AND LOWER 30S
TONIGHT. THE SYNOPTIC LIFT FROM THE UPPER LEVEL LOW WILL LIKELY
RESULT IN LIGHT RAIN AND SNOW MOVING INTO THE NW FORECAST AREA.
LITTLE OF ANY SNOW ACCUMULATION IS EXPECTED SINCE MUCH OF IT
SHOULD MELT...EITHER ON IMPACT OR LATER IN THE MORNING.
MONDAY...IT WILL BE MUCH COOLER DAY WITH BLUSTERY NW WINDS.
SUSTAINED WINDS OF 10 TO 20 MPH WILL DEVELOP BY THE
AFTERNOON...AND THERE COULD BE GUSTS UP TO 30 MPH. THE 850 HPA
TEMPERATURES WILL BE ABOUT -5 TO -6 DEGREES CELSIUS. HEAVY CLOUD
COVER AND THE COOL NW FLOW WILL PREVENT HIGHS FROM GETTING MUCH
HIGHER THAN THE LOW TO MIDDLE 40S. THERE WILL BE INCREASING
CHANCES OF COLD RAIN SHOWERS AS THE UPPER LOW DEEPENS AND MOVES TO
JUST NORTH OF KOOCHICHING COUNTY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
A DEEP AREA OF LOW PRESSURE WILL SETTLE SOUTHWARD INTO THE LAKE
SUPERIOR REGION MONDAY NIGHT AND TUESDAY. THE CLOSED H5 LOW WILL
REACH WESTERN LAKE SUPERIOR BY TUESDAY AFTERNOON. NUMEROUS
SHOWERS WILL ROTATE SOUTHWARD AROUND THE UPPER LOW...GENERALLY IN
THE FORM OF SNOW SHOWERS AT NIGHT AND RAIN OR SNOW SHOWERS DURING
THE DAY THROUGH THE MIDDLE OF THE WEEK. DEFINITELY COULD BE SOME
SLUSHY ACCUMULATION AT TIMES...ESPECIALLY IN THE NORTH. WOULD NOT
BE SURPRISED TO SEE A COUPLE EPISODES OF UP TO A COUPLE INCHES...
FOLLOWED BY SOME PARTIAL TO FULL MELTING DURING THE DAY. THIS
MASSIVE UPPER LEVEL TROUGH WILL EVENTUALLY LOSE ITS GRIP ON THE
AREA FROM THE MIDDLE TO THE END OF THE WORK WEEK. THE GEM AND TO
SOME EXTENT THE ECMWF ARE THE MOST AGGRESSIVE IN PUSHING THE
UPPER TROUGH EASTWARD THROUGH THE END OF THE WEEK...WITH THE GEM
BRINGING UPPER LEVEL RIDGING ALREADY INTO THE CWA BY 12Z FRIDAY.
THE GFS IS MUCH SLOWER AND DEEPER WITH THE UPPER LEVEL LOW.
STRONGLY FAVORING THE GEM/ECMWF SOLUTION...ESPECIALLY LATE IN THE
WEEK AND INTO THE WEEKEND. HIGH TEMPERATURES WILL REMAIN ON THE
COOL SIDE DURING THE WEEK...REACHING BACK INTO THE LOW TO MID 50S
ON THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 101 AM CDT SUN APR 19 2015
AN AREA OF LOW PRESSURE WILL SPREAD GRADUALLY LOWERING CLOUDS AND
RAINFALL INTO THE AREA FROM THE SOUTHWEST THROUGH 10Z...WITH
CEILINGS SLOWLY LOWERING TO IFR WITH VISIBILITIES TO MVFR IN
LIGHT RAIN. THIS WILL CONTINUE THROUGH APPROXIMATELY 18Z BEFORE
SLOWLY DIMINISHING AGAIN FROM SOUTHWEST TO NORTHEAST. CEILINGS
EXPECTED TO REMAIN MVFR-IFR UNTIL AFTER LOW PASSAGE AND WINDS
TURN TO NORTHWEST...ALLOWING CEILINGS AND VISIBILITIES TO
GRADUALLY RETURN TO MVFR...THEN VFR BY 02Z THIS EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 36 42 30 / 90 40 60 50
INL 49 32 40 27 / 100 50 70 60
BRD 55 36 42 30 / 90 20 60 40
HYR 56 37 44 31 / 90 60 50 50
ASX 56 38 45 32 / 80 60 50 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR LSZ142>147.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...DAP
AVIATION...DAP
AREA FORECAST DISCUSSION...UPDATED
NWS SPRINGFIELD MO
1201 AM CDT Sun Apr 19 2015
...Updated Aviation Section...
.UPDATE...
Issued at 703 PM CDT SAT APR 18 2015
Forecast will be updated shortly to account for short term trends
from satellite/radar as well as to account for expected convective
trends heading into the overnight hours.
Over the past few hours, we have seen clearing across western
portions of the area. This clearing will likely be short lived as
mid/high level clouds increase from the west from convective
exhaust. That said, this area did see a soaking rain this morning
and dewpoints remain relatively high compared to expected lows. As
a result, will include a mention of patchy fog and keep an eye on
localized dense fog potential in places where skies can remain
clear for a longer period of time.
In addition, PoPs have been updated for the next 12 or so hours.
The western half of the area will likely see little in the way of
rain chances this evening. Chances over the eastern half look to
remain in the solid chance range giving on again/off again showers
and isolated thunder. HRRR and other short range models continue
to indicate rain chances increasing across south central Missouri
and the eastern Ozarks from late this evening into the overnight
hours. In addition, remnant convection from KS/OK complexes will
enter from the west, with rain chances steadily increasing
across extreme southeastern Kansas and western Missouri.
Interestingly, the Highway 65 corridor will likely be between
these two areas of activity and PoPs are lowest in this area for
tonight.
Taking a peak at tomorrow`s severe weather potential. There
remains some question as to just how much instability we will be
able to generate as decaying convection continues to spread in
from the west during the morning hours. The main upper trough will
not arrive until later in the day, bringing and increase in deep
layer shear. However, models struggle to bring much more that
500-1000 J/kg of most unstable CAPE into the southern half of the
area. By far the better chances for severe convection will be to
our south and southeast. Obviously this is close enough to keep a
close eye on trends and we will see what the 00z suite of models
have in store for the area.
&&
.SHORT TERM...(This Evening through Sunday Night)
Issued at 315 PM CDT SAT APR 18 2015
The coverage of showers and thunderstorms continued to decrease into
the afternoon. However a band of scattered showers and storms persisted
along a 925-850 MB convergence axis that stretched north to south
east of the Highway 65 corridor and in advance of a mid level vorticity
lobe lifting northeast across the area. Expect convection through
early evening to be focused along and ahead of these features
across south central Missouri. This 925-850 MB convergence axis
may become the focus for additional development later tonight
across the eastern Ozarks as another vorticity lobe lifts
northeast toward southeastern Missouri. Coverage of precipitation
will remain more isolated elsewhere much of tonight. However there
may be increase in convection from the west into southeastern
Kansas into far southwest late tonight as convection across the
Plains shifts eastward.
The closed upper level low now over eastern Colorado will open up
and track eastward toward Missouri on Sunday. Expect the coverage
of convection to increase Sunday as synoptic scale lift increases
with the aide of an increasingly diffluent upper flow and the
approach of vorticity maxima.
Deep layer shear will increase Sunday as the mid level flow
strengthens and lapse rates steepen as temperatures aloft cool in
response to the approaching upper level trough.
The question is the extent of instability that will develop. The
potential for ongoing convection and cloud cover may limit surface
heating and resulting instability. However if sufficient
instability can be realized then ingredients would be in place for
at least a few severe storms.
At this time the greatest potential for strong to severe storms
will be across far southern Missouri or generally along and south
of Interstate 44. The risk for severe weather could decrease or
increase depending on the amount of destabilization. The primary
risks with any severe storms that can develop would damaging winds
and large hail.
With some areas already receiving moderate to heavy rainfall the
past couple of days...the risk for localized flooding will have to
be monitored particularly across far southwestern Missouri.
Showers and some thunder will linger into Sunday night as the
upper level trough and associated cold front track across the
area.
.LONG TERM...(Monday through Saturday)
Issued at 315 PM CDT SAT APR 18 2015
Much cooler weather will prevail heading into early next week as
an upper level trough digs into the Great Lakes and maintains a
northwesterly flow aloft across the region. This cooler weather
will persist most of next week. Weather conditions could also be
rather unsettled as disturbances slide southeastward around the
periphery of the upper trough. This will bring intervals clouds and
the possibility of showers and thunderstorms at times mid through
late week. However this activity is expected to be spotty in
nature.
Temperatures could fall into the upper 30s Monday night. Frost is
not expected at this time but this potential should be monitored.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1201 AM CDT SUN APR 19 2015
Challenging forecast for area aerodromes as convection will fester
around the region the rest of tonight, and regenerate Sunday
afternoon. Decaying bands of showers/storms will attempt to enter
from the west in the coming hours, however a lack of instability
will likely result in this activity losing its punch and gradually
dissipating as it moves through the JLN aerodrome. Earlier
clearing at SGF/BBG is being replaced by mid/high level clouds.
There is patchy ground fog around, but this may not become too
widespread. Bouts of MVFR visibility are expected, with an outside
chance of IFR at BBG. Main storm system will move into area Sunday
afternoon/evening. Another round of showers/storms will be
associated with this system, which will begin to exit to the east
by the end of the TAF cycle. Winds will be light into the daylight
hours of Sunday morning, becoming southwesterly during the day and
shift to the northwest heading into the evening.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
UPDATE...Gagan
SHORT TERM...Foster
LONG TERM...Foster
AVIATION...Gagan
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
314 AM CDT SUN APR 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT SUN APR 19 2015
THE UPPER LOW WHICH PRODUCED UP TO 52 INCHES OF SNOW IN COLORADO
HAS DRIFTED EAST INTO WRN KS THIS MORNING. RAIN AND THUNDERSTORMS
ARE FALLING UNDER THE LOW. A DEFORMATION ZONE OF RAIN AND
ISOLATED THUNDERSTORMS IS WEAKENING ACROSS NCNTL AND SWRN NEB
THIS MORNING. THE MODELS DRAG THIS AREA OF RAIN SOUTH AND OUT OF
THE FORECAST AREA BY 15Z-18Z. A STRONG COLD FRONT WITH SCATTERED
SHOWERS WILL DROP THROUGH THE FCST AREA THIS MORNING SETTING UP A
WINDY AND COOL DAY. NORTHWEST WINDS WILL INCREASE TO 20 TO 30 MPH
WITH GUSTS TO 40 MPH. THESE WINDS ARE ALREADY UNDERWAY IN THE
PANHANDLE.
THE STRONG WINDS BEND AROUND THE BLACK HILLS PRODUCING
CONVERGENCE ACROSS SHERIDAN AND CHERRY COUNTIES. THE HRRR SHOWS
SPRINKLES DEVELOPING BUT GIVEN THE VERY DRY AIR MOVING IN WITH
DEW POINTS FALLING INTO THE 20S BY NOON...NO MEASURABLE RAINFALL
WOULD BE EXPECTED.
HIGHS TODAY RISE INTO THE 50S WITH PARTLY CLOUDY SKIES. THE
MODELS ARE BRINGING IN COLD AIR ALOFT FROM AN UPPER LEVEL ACROSS
MANITOBA. THE RESULT IS H700MB TEMPERATURES FALL TO AROUND -10C
BY 21Z. SOME SUN IS EXPECTED BUT SKIES WOULD LIKELY CLOUD UP IN
THE AFTERNOON WITH THE COLD AIR ALOFT.
TONIGHT...THE UPPER LOW ACROSS WRN KS WILL LIFT INTO THE UPPER
MIDWEST AND BE ABSORBED THE A DISTURBANCE ACROSS WRN ONTARIO
TONIGHT. THIS WILL PULL PACIFIC HIGH PRESSURE INTO THE FCST AREA.
GENERALLY CLEAR SKIES ARE EXPECTED WITH LOWS IN THE 20S TO LOWER
30S. WINDS STAY UP AT 10 TO 15 MPH NEAR ONEILL WHERE THE WARMER
LOWS ARE EXPECTED.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 313 AM CDT SUN APR 19 2015
MONDAY INTO MID WEEK WILL SEE THE LOW PRESSURE SYSTEMS TO THE
NORTHEAST AND EAST MERGE NEAR/NORTH OF THE GREAT LAKES. MEANWHILE
NORTHWEST FLOW DOMINATES THE HIGH PLAINS AND AN UPPER LEVEL
TROUGH DIGS ACROSS THE PACIFIC COAST. THE LOW PRESSURE SYSTEM TO
THE NORTHEAST WILL DRAW SOME COOL AND DRY CANADIAN AIR TO THE
REGION. TEMPERATURES WILL BE THE MAIN FOCUS THROUGH MID WEEK AND
ARE TRICKY. THE DRY AIR MOVING SOUTH WILL ALLOW FOR DEW POINTS TO
FALL INTO THE TEENS AND 20S...HOWEVER WITH THE RECENT HEAVY
RAIN...THOUGHT MODELS ARE A TAD TO DRY SO DID RAISE SLIGHTLY BUT
COULD SEE THEM BEING HIGHER...ESPECIALLY BY WED. SKIES WILL
GENERALLY BE MOSTLY CLEAR...ALTHOUGH A COUPLE WEAK CLIPPERS MAY
BRING A BRIEF INCREASE OF CLOUDS. WITH MOSTLY CLEAR SKIES AND DRY
AIR TEMPS TO LIKELY FALL TO OR BELOW THE FREEZING MARK FOR THE
FIRST FEW DAYS OF THE WEEK...UNLESS BL MOISTURE ENDS UP BEING
MORE THAN EXPECTED FROM RECENT RAIN. MEANWHILE AFTERNOON SUN WILL
HELP OFFSET THE COOL CONDITIONS AND BE ABLE TO AID IN MIXING THE
BL...SEASONAL HIGHS /50S AND 60S/ EXPECTED. ONE CONCERN WITH
HIGHS IS THE COOL TEMPS ALOFT...WHICH MAY RESULT IN SOME
AFTERNOON CLOUDS DUE TO STEEP LAPSE RATES DEVELOPING. FAIRLY DRY
AIR AT THE SFC SO NOTHING EXPECTED TO REACH THE GROUND.
BY THE END OF THE WEEK THE WEST COAST TROUGH WILL BECOME AN OPEN
WAVE CROSSING THE DESERT SW/4 CORNERS. A TRANSITION FROM NW TO SW
FLOW WILL BRING A RETURN FOR WET WEATHER. MODELS NOT IN THE BEST
OF AGREEMENT ON TIMING...BUT DO PUSH THE WAVE ONTO THE
SOUTHERN/CENTRAL PLAINS BY THE WEEKEND. SHOULD SEE A BRIEF WINDOW
OF RETURN MOIST SOUTHEASTERLY FLOW AHEAD OF THE WAVE. THIS TRACK
AND THE INCREASE OF MOISTURE WILL FAVOR A CHANCE FOR
RAIN...ALBEIT BETTER FOR SOUTHERN ZONES THAN NORTHERN ZONES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1152 PM CDT SAT APR 18 2015
THE THUNDERSTORMS IN CENTRAL NEBRASKA ARE WEAKENING. LATER
TONIGHT...AS THE UPPER LOW MAKES ITS WAY ONTO THE PLAINS...
SCATTERED SHOWERS WILL COALESCE INTO WIDESPREAD RAIN AFTER 06Z
SOUTH OF AN ONL-MHN-OGA LINE. THEN...AS A FRONT COME
THROUGH...RAIN WILL END FROM THE NORTH IN CENTRAL NEBRASKA BY 11Z
AND IN SOUTH CENTRAL AND SOUTHWEST NEBRASKA EARLY AFTERNOON. THE
RAIN IS EXPECTED TO END BBW-LBF-IML AROUND 13Z.
AFTER 08Z...WIND WILL SHIFT TO 340-360 AT 10-16KT AND THEN
INCREASE TO 14-18G24-30KT BY 14Z
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1154 PM CDT SAT APR 18 2015
.SYNOPSIS...
ISSUED AT 255 PM CDT SAT APR 18 2015
ANALYSIS OF THE 19Z MSL DATA SHOWED LOW PRESSURE CENTERED IN WESTERN
KANSAS WITH A WARM FRONT ACROSS NORTHERN KANSAS...A COLD FRONT INTO
THE OKLAHOMA/TEXAS PANHANDLE AND AN INVERTED TROUGH FROM SOUTHWEST
TO NORTH CENTRAL NEBRASKA. IN THE UPPER LEVELS...THE WATER VAPOR
IMAGERY SHOWED A CLOSED CYCLONIC CIRCULATION LOCATED IN EASTERN
COLORADO.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 255 PM CDT SAT APR 18 2015
THE CENTER OF STRONG CUT OFF LOW /H500 MB TEMP -25C/ IS NEAR AKRON
COLORADO THIS AFTERNOON. HIGH RES MODELS INSIST THAT
CONVECTION...AIDED BY A SIGNIFICANT PV ANOMALY ROTATING NORTHEAST
INTO WESTERN KANSAS AROUND THE LOW CENTER...WILL DEVELOP ONCE AGAIN
ACROSS NORTHWEST KANSAS AND SOUTHWEST NEBRASKA LATE THIS AFTERNOON
AND THIS EVENING. THE ACTIVITY WILL GROW UPSCALE MUCH LIKE LAST
NIGHT AS IT MOVES NORTH/NORTHEAST INTO THE REST OF WESTERN...CENTRAL
AND NORTH CENTRAL NEBRASKA TONIGHT.
AS FAR AS SEVERE POTENTIAL...GOOD SURFACE HEATING UNDERWAY ATTM
ACROSS SOUTHWEST NEBRASKA AND NORTHWEST KANSAS. EXPECTING MUCAPE ON
THE ORDER OF 1500 J/KG BY LATE AFTERNOON INTO THE EVENING HOURS. ONE
WEAKNESS ARE THE WIND FIELDS ARE FAIRLY LIGHT...AND NOT A A LOT OF
VEERING WITH HEIGHT. NEVERTHELESS WITH THE STEEP LOW AND MID LEVEL
LAPSE RATES...WILL SEE SOME VIGOROUS UPDRAFTS...AND SOME HAIL LIKELY
WITH THOSE STRONGER UPDRAFTS. TORNADO POTENTIAL IS NOT ZERO...BUT
AGAIN WITH THE WEAK WIND FIELDS AND LIMITED VEERING...NOT EXPECTING
THAT TO BE THE PRIMARY RISK. IF A TORNADO OCCURS IT WOULD MORE THAN
LIKELY BE WEAK. K INDICES ARE HIGH...AND LOCALLY HEAVY RAINFALL
WILL BE POSSIBLE.
THE CLOSED H500 MB CIRCULATION IS FORECASTED TO MIGRATE INTO
NORTHWEST KANSAS BY SUNDAY MORNING...AND CONTINUE EAST ACROSS KANSAS
DURING THE DAY. A SMALL DEFORMATION BAND OF PRECIPITATION IS LIKELY
ON THE NORTH AND WEST SIDE OF THE TRACK. THE EXACT TRACK OF THE LOW
CENTER IS UNCERTAIN...AS CONVECTION LIKELY TO INFLUENCE THE MASS
FIELD AND EXPECT THE FINAL TRACK COULD END UP A LITTLE FARTHER
NORTH. THIS IS HINTED IN THE LATEST RUN OF THE RAP MODEL. OTHERWISE
A COLD FRONT ASSOCIATED WITH A SEPARATE NORTHERN STREAM SYSTEM WILL
CRASH THROUGH THE AREA...BRINGING GUSTY NORTHWEST WINDS TO THE
REGION.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 255 PM CDT SAT APR 18 2015
MEDIUM RANGE...(SUNDAY NIGHT THROUGH TUESDAY)
THE UPPER LEVEL LOW ACROSS COLORADO WILL LIFT OUT AND COLLIDE WITH
AN UPPER LEVEL SHORT WAVE ACROSS ACROSS THE NORTHERN GREAT LAKES
FORMING A VERY LARGE CLOSED UPPER LOW. UPSTREAM HEIGHTS RISE SHARPLY
ACROSS NRN CANADA SUPPORTING A BROAD AREA OF HIGH PRESSURE WHICH
CIRCULATE COOL AIR SOUTH THROUGH THE PLAINS AND MIDWEST. THIS KEEPS
THE FORECAST AREA IN COOL NORTHWEST FLOW. DAYTIME MIXING PRODUCES
PARTLY CLOUDY SKIES MONDAY AND TUESDAY PLACING A LIMIT ON HEATING.
MONDAY WOULD BE A WINDY DAY WITH NORTHWEST WINDS INCREASING TO 20
TO 30 MPH IN THE AFTN WHICH WEAKEN AT SUNSET. WINDS STAY REASONABLY
STRONG SUNDAY NIGHT ALSO. THE EFFECT ON TEMPERATURES WOULD BE FOR
LOWS MONDAY MORNING FALLING INTO THE UPPER 20S ACROSS WESTERN
NEBRASKA BUT ABOVE FREEZING EAST OF HIGHWAY 83. LOWS FALL BELOW
FREEZING EVERYWHERE MONDAY NIGHT EXCEPT ALONG HIGHWAY 281. HIGHS
RISE INTO THE 50S MONDAY AND LOWER 60S TUESDAY.
THE FORECAST IS DRY AND THE MODELS INDICATE DEW POINTS FALL INTO
TEENS AND 20S SUNDAY NIGHT THROUGH TUESDAY. THE RISK TO THE FORECAST
IS THAT THE VERY DRY AIR COULD SUPPORT COLDER LOWS THAN FORECAST BUT
THAT WOULD COMPETE DIRECTLY WITH THE WARM WET GROUND FROM THE HEAVY
RAINFALL.
EXTENDED RANGE...(TUESDAY NIGHT THROUGH SATURDAY)
A RIDGE IN WESTERN NORTH AMERICA CONTINUES TO BUILD INTO THE
NORTHWEST TERRITORIES AND NORTHERN ALBERTA OPENING UP A PATH FROM
NUNAVUT IN EXTREME NORTHERN CANADA TO NORTH CENTRAL AND NORTHEAST
NEBRASKA. AS A RESULT...TEMPERATURES ARE EXPECTED TO BE A LITTLE
BELOW THE SEASONAL AVERAGES IN THE NORTHEAST NEBRASKA SANDHILLS AND
THE NIOBRARA VALLEY WITH NIGHTTIME TEMPERATURES AT OR BELOW FREEZING
INTO FRIDAY MORNING. EVEN IN THE WESTERN SANDHILLS...THE EASTERN
PANHANDLE AND SOUTHWEST NEBRASKA WILL BE SLIGHTLY BELOW AVERAGE
WITH LOWS IN THE LOW TO MID 30S.
IN THE SOUTHWEST STATES...A TROUGH DIGS INTO SOUTHERN CALIFORNIA
RESULTING IN SOUTHWEST FLOW ALOFT ACROSS THE CENTRAL PLAINS. A WEAK
INVERTED TROUGH MOVING ACROSS THE PLAINS COULD BRING THE POSSIBILITY
OF SHOWERS TO CENTRAL AND WESTERN NEBRASKA THURSDAY THROUGH
SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1152 PM CDT SAT APR 18 2015
THE THUNDERSTORMS IN CENTRAL NEBRASKA ARE WEAKENING. LATER
TONIGHT...AS THE UPPER LOW MAKES ITS WAY ONTO THE PLAINS...
SCATTERED SHOWERS WILL COALESCE INTO WIDESPREAD RAIN AFTER 06Z SOUTH
OF AN ONL-MHN-OGA LINE. THEN...AS A FRONT COME THROUGH...RAIN WILL
END FROM THE NORTH IN CENTRAL NEBRASKA BY 11Z AND IN SOUTH CENTRAL
AND SOUTHWEST NEBRASKA EARLY AFTERNOON. THE RAIN IS EXPECTED TO END
BBW-LBF-IML AROUND 13Z.
AFTER 08Z...WIND WILL SHIFT TO 340-360 AT 10-16KT AND THEN INCREASE
TO 14-18G24-30KT BY 14Z
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SPRINGER
SHORT TERM...TAYLOR
LONG TERM...CDC/SPRINGER
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
337 AM MDT SUN APR 19 2015
.SYNOPSIS...
AN OVERALL UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE NORTHERN
HIGH TERRAIN AND THE NORTHEAST PLAINS THROUGH ALL OF THIS WEEK. HIGH
TEMPERATURES WILL SLOWLY TREND BACK TOWARD NORMAL THROUGH THE MIDDLE
OF THE WEEK AHEAD OF THE NEXT STORM SYSTEM APPROACHING FROM THE WEST.
DRY SOUTHWEST WINDS WILL INCREASE WEDNESDAY AND THURSDAY FOR WESTERN
AND CENTRAL NEW MEXICO. THE CHANCES FOR SHOWERS AND THUNDERSTORMS
WILL INCREASE AGAIN FOR ALL AREAS FRIDAY AS THE CORE OF AN UPPER LOW
SLIDES OVERHEAD. COOLER TEMPERATURES WILL MOVE BACK INTO THE AREA
BEHIND THIS SYSTEM...WHILE THE CHANCES OF PRECIPITATION CONTINUE
OVER THE NORTH THROUGH NEXT WEEKEND.
&&
.DISCUSSION...
THE FINAL VESTIGES OF WRAP-AROUND PRECIP ARE IMPACTING THE FRONT
RANGE OF COLORADO THIS MORNING AS EVIDENCED BY WIDESPREAD SHOWERS
AND GUSTY NORTH WINDS. THIS ACTIVITY IS INDICATED BY THE 00Z/06Z
NAM AND HRRR GUIDANCE TO CLIP NORTHEAST NM THIS MORNING. QPF WILL
BE LIGHT WITH MOST AREAS REPORTING LESS THAN A TENTH. HIGHS AGAIN
TODAY WILL BE BELOW NORMAL ALL AREAS...WITH READINGS 10-15F BELOW
NORMAL FOR THE EAST. HIGH PRESSURE BUILDING DOWN THE FRONT RANGE
TONIGHT BEHIND THE DEPARTING UPPER LOW WILL HELP FORCE LIGHT GAP
WINDS INTO THE RIO GRANDE VALLEY LATE TONIGHT.
ONE LAST UPPER VORT TRANSLATION WITHIN NW FLOW BEHIND THE DEPARTING
WAVE WILL SLIDE OVER THE NORTHERN MTS AND NE PLAINS MONDAY. THIS
WILL FORCE ANOTHER ROUND OF AFTERNOON SHOWERS NEAR THE HIGH TERRAIN
AS FAR SOUTH AS I-40. AGAIN TEMPS WILL BE BELOW NORMAL WITH A SLIGHT
TREND TOWARD NORMAL FOR THE FAR WEST.
AN AMORPHOUS COMPLEX OF UPPER LEVEL LOW PRESSURE CURRENTLY TAKING
SHAPE ALONG THE WEST COAST WILL BECOME THE NEXT WEATHER PLAYER FOR
MID TO LATE WEEK. GUIDANCE SHOWS H5 HEIGHTS DEEPENING INTO A 562DM
LOW TUESDAY OVER SOUTHERN CALIFORNIA WITH A WEAK SHORTWAVE RIDGE
SLIDING OVER NM. THIS WILL TREND SHOWER AND WIND ACTIVITY DOWNWARD
FOR NM. A 90-110KT 300MB JET AXIS THEN CARVES SOUTHWARD ALONG THE
WEST COAST AND DEEPENS THE TROUGH INTO A TIGHTLY WOUND 550DM H5 LOW
OVER SOUTHERN CALIFORNIA THROUGH THURSDAY. THIS WILL INCREASE MID
LEVEL FLOW AND DEEPEN THE LEE SIDE TROUGH OVER EASTERN NM. WINDS
AND TEMPS WILL INCREASE OVER THE STATE WITH SOME POSSIBLE MARGINAL
FIRE WEATHER ISSUES NOTED WEDNESDAY AND/OR THURSDAY.
BEYOND THURSDAY THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE
TRANSLATION OF LOW PRESSURE OVER NM BY FRIDAY/SATURDAY AND INTO
NEXT WEEK. THE GFS AND ECMWF OPEN THE WAVE AND SLIDE DISORGANIZED
PRECIP OVER THE AREA...FOLLOWED BY A SERIES OF FAST MOVING WEAKLY
DEFINED SHORTWAVE TROUGHS AND RIDGES.
GUYER
&&
.FIRE WEATHER...
WHILE SOME POTENTIAL STILL REMAINS...AS IT CURRENTLY LOOKS THE RISK
OF A RETURN OF CRITICAL FIRE WX CONDITIONS THURSDAY AND FRIDAY HAS
DIMINISHED SOMEWHAT.
A BACK DOOR FRONT MOVING ACROSS THE EASTERN PLAINS THIS MORN AND
INTO THE AFTN WILL BRING INCREASINGLY STRONG AND GUSTY WINDS TO THE
NE PLAINS AND TO A LESSER DEGREE THE EAST CENTRAL PLAINS THIS MORN.
GUSTS NEAR 45 OR 50 MPH ARE POSSIBLE NEAR CLAYTON THIS MORN. WIND
SPEEDS ARE EXPECTED TO DECREASE SOMEWHAT THIS AFTN. CRITICAL FIRE WX
CONDITIONS NOT EXPECTED AS HUMIDITIES TO REMAIN TOO HIGH. AFTN TEMPS
WILL ONLY BE SLIGHTLY COOLER TODAY AS COMPARED TO SATURDAY BEHIND
THE FRONT. AS THE FRONT BACKS UP TO THE CENTRAL MTN CHAIN...EXPECT A
FEW HIGH BASED SHOWERS AND THUNDERSTORMS TO DEVELOP DUE TO UPSLOPE
FLOW...MORE SO ALONG THE EAST SLOPES OF THE SANGRE DE CRISTO MTNS
AND LESS SO FARTHER SOUTH. HUMIDITY RECOVERIES TONIGHT WILL BE GOOD
TO EXCELLENT MOST AREAS OUTSIDE OF WEST CENTRAL AND SW NM WHERE FAIR
TO GOOD RECOVERIES TO BE THE RULE. LOW TEMPS WILL BE A LITTLE ABOVE
NORMAL WEST AND CENTRAL...A BIT BELOW EAST. HIGH TEMPS ON SUNDAY
WILL REMAIN BELOW NORMAL ACROSS THE EAST DUE TO THE FRONTAL
PASSAGE...THOUGH WILL BE INCHING UP TOWARD NORMAL ACROSS THE WEST.
LATER MON...WEAK RIDGE ALOFT WILL DEVELOP ACROSS WESTERN NM...THOUGH
ENOUGH RESIDUAL MOISTURE WILL BE AROUND TO TRIGGER A FEW HIGH BASED
BUILDUPS AND VIRGA IN THE AFTERNOON HOURS. A FEW SPRINKLES MAY
ACTUALLY REACH THE GROUND ACROSS THE NORTHERN HIGH TERRAIN...THOUGH
THE BIGGER CONCERN MAY BE ERRATIC WIND GUSTS WITH ANY VIRGA ACROSS
WESTERN NM. OTHERWISE TEMPS SHOULD WARM TO AROUND 5 DEGREES OF
NORMAL EAST...VERY CLOSE TO NORMAL WEST.
THE BACK DOOR COLD FRONT EARLIER SCHEDULED TO ARRIVE LATER MON NIGHT
INTO TUE MORN HAS BEEN MARGINALIZED AND IN SOME MODELS ELIMINATED
FROM THE SCENE COMPLETELY. STILL MAY BE JUST ENOUGH MOISTURE AND
WEAK UPSLOPE TO CREATE A FEW SHOWERS AND THUNDERSTORMS TUE AFTN WITH
AID OF AFTN HEATING.
WED LOOKS TO BE BREEZY IN MANY AREAS...BUT FOR THE MOST PART THE
STRONGEST WINDS STILL ARE EXPECTED TO ARRIVE THU AND FRI. BUT
CRITICAL CONDITIONS HAVE SHRUNK SIGNIFICANTLY THU AND DO NOT APPEAR
AT ALL FOR FRI. THIS MAY ONLY BE A TEMPORARY REDUCTION AS FCST
MODELS SEEM TO BE IN TRANSITION AGAIN IN THEIR DEPICTION OF UPPER
LVL LOW PRESSURE EVOLUTION OFF TO OUR WEST. THE BACK DOOR FRONT WILL
BE REINFORCED ACROSS NE NM AND SOME THUNDERSTORMS MAY DEVELOP THERE
THU AFTN.
NO VENTILATION ISSUES ARE EXPECTED FOR THE NEXT 6 DAYS...WITH MAINLY
VERY GOOD TO EXCELLENT VENT RATES EXPECTED...THOUGH FAR NORTHEAST NM
MAY DROP INTO THE FAIR OR GOOD CATEGORIES MID TO LATE WEEK. SAT MAY
SEE SOME EROSION OF VENTILATION RATES.
43
&&
.AVIATION...
06Z TAF CYCLE
A POTENT BACKDOOR COLD FRONT WILL SLIDE DOWN THE ERN PLAINS
OVERNIGHT INTO EARLY SUNDAY MORNING. STRONG NORTH WINDS OF 20 TO
30KT WITH GUSTS NEAR 45 KT WILL BE POSSIBLE ACROSS NE NM...ESPECIALLY
BETWEEN 09Z AND 18Z SUNDAY. THE BACKDOOR FRONT WILL RESULT IN
ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS SUNDAY...MAINLY OVER
THE NORTHERN AND SOUTHWEST MOUNTAINS AND ALONG THE EAST SLOPES OF
THE CENTRAL MOUNTAIN CHAIN INCLUDING KLVS. WITH WEST TO NORTHWEST
FLOW ALOFT IN PLACE AND ELY UPSLOPE SFC FLOW...A FEW STRONG STORMS
ARE POSSIBLE DURING THE LATE AFTERNOON AND EARLY EVENING FROM THE
EAST SLOPES SANGRE DE CRISTOS EWD TO THE NE PLAINS.
33
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 65 34 70 37 / 5 0 5 5
DULCE........................... 62 25 62 28 / 10 10 20 10
CUBA............................ 62 32 64 35 / 10 10 10 10
GALLUP.......................... 65 29 69 32 / 5 5 10 5
EL MORRO........................ 59 33 64 35 / 10 10 10 5
GRANTS.......................... 63 29 67 31 / 10 5 10 5
QUEMADO......................... 61 37 65 37 / 10 5 10 5
GLENWOOD........................ 74 45 76 44 / 5 5 5 5
CHAMA........................... 54 25 55 25 / 20 20 20 10
LOS ALAMOS...................... 57 40 62 41 / 20 10 20 10
PECOS........................... 57 33 60 38 / 10 10 10 10
CERRO/QUESTA.................... 54 24 55 26 / 20 30 30 20
RED RIVER....................... 45 25 46 29 / 30 50 40 30
ANGEL FIRE...................... 48 21 51 24 / 30 30 30 20
TAOS............................ 55 28 59 30 / 20 20 20 20
MORA............................ 54 29 58 34 / 20 20 20 20
ESPANOLA........................ 62 38 66 39 / 10 10 10 10
SANTA FE........................ 57 38 61 41 / 10 10 10 10
SANTA FE AIRPORT................ 63 34 66 36 / 10 10 10 10
ALBUQUERQUE FOOTHILLS........... 65 43 69 46 / 10 5 5 10
ALBUQUERQUE HEIGHTS............. 67 44 71 46 / 5 5 5 5
ALBUQUERQUE VALLEY.............. 68 39 72 41 / 5 5 5 5
ALBUQUERQUE WEST MESA........... 69 41 71 45 / 5 5 5 5
LOS LUNAS....................... 70 36 74 39 / 5 5 5 5
RIO RANCHO...................... 68 42 70 46 / 5 5 5 5
SOCORRO......................... 71 44 75 46 / 10 5 10 5
SANDIA PARK/CEDAR CREST......... 62 38 65 44 / 10 10 10 10
TIJERAS......................... 65 38 67 43 / 10 10 10 10
MORIARTY/ESTANCIA............... 61 29 66 32 / 10 10 10 10
CLINES CORNERS.................. 61 32 63 39 / 10 10 10 10
GRAN QUIVIRA.................... 63 39 66 42 / 10 10 10 10
CARRIZOZO....................... 68 44 70 46 / 10 10 5 5
RUIDOSO......................... 65 37 65 43 / 10 10 5 5
CAPULIN......................... 48 30 55 35 / 40 30 30 30
RATON........................... 54 28 58 31 / 20 40 30 30
SPRINGER........................ 55 31 64 35 / 10 50 20 30
LAS VEGAS....................... 57 29 61 37 / 10 20 20 20
CLAYTON......................... 56 33 63 40 / 20 10 20 40
ROY............................. 56 30 63 37 / 5 20 20 30
CONCHAS......................... 63 39 70 44 / 0 5 10 20
SANTA ROSA...................... 64 35 69 43 / 5 5 10 10
TUCUMCARI....................... 66 35 72 43 / 0 5 10 30
CLOVIS.......................... 65 37 68 43 / 0 5 5 20
PORTALES........................ 68 38 70 45 / 0 0 0 20
FORT SUMNER..................... 67 38 70 44 / 0 5 5 10
ROSWELL......................... 71 44 72 45 / 0 5 0 5
PICACHO......................... 68 40 69 44 / 5 10 5 5
ELK............................. 65 38 65 44 / 10 10 5 5
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ530.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
121 AM EDT SUN APR 19 2015
.SYNOPSIS...
AN APPROACHING FRONTAL SYSTEM WILL BRING SHOWERS AND A CHANCE OF
THUNDERSTORMS TODAY THROUGH MONDAY. A FEW STORMS COULD BE STRONG TO
SEVERE MONDAY. DRY AND SEASONABLE HIGH PRESSURE WILL BUILD INTO THE
AREA TUESDAY AND WEDNESDAY. A WEAK COLD FRONT MAY BRING SHOWERS AND
ISOLATED THUNDERSTORMS INTO LATE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 130 AM SUNDAY...WE`RE PROBABLY AT A CONVECTIVE MINIMUM RIGHT
NOW. LATEST HRRR AND HRRRX MODELS SHOW AN INCREASE IN SHOWER
ACTIVITY LATE TONIGHT...AND ESPECIALLY AROUND DAYBREAK ACROSS THE
PEE DEE REGION AS THE DEVELOPING WARM FRONT AND BETTER UPPER SUPPORT
ARRIVES FROM THE SOUTHWEST. A FEW DOWNWARD TWEAKS HAVE BEEN MADE TO
FORECAST LOW TEMPS NEAR THE COAST. DISCUSSION FROM 1030 PM FOLLOWS...
THE DIURNALLY INDUCED CONVECTION CONTINUES TO DISSIPATE ACROSS THE
FA AND IS NOW BASICALLY WIDELY SCATTERED IN COVERAGE...AND IN THE
FORM OF LIGHT RAIN SHOWERS. WILL DROP POPS TO ISOLATED IN COVERAGE
FOR PORTIONS OF THE ILM CWA BUT ONLY FOR TEMPORARILY THIS EVENING UP
TO A FEW HRS AFTER MIDNIGHT. WITH A SFC COLD FRONTAL BOUNDARY
DROPPING SOUTH AND POSSIBLY BACKDOORING THE FA OVERNIGHT BEFORE
TEMPORARILY STALLING...AND A FEW LEFTOVER SHALLOW MESOSCALE SFC
BOUNDARIES PRESENT. WILL NOT ENTIRELY REMOVE PCPN FOR THE REMAINDER
OF THE OVERNIGHT.
IN FACT...DURING THE PRE-DAWN HRS OF SUNDAY THRU DAYBREAK...LOOK
FOR POPS TO RAMP BACK UP ACROSS THE ILM CWA FROM SW TO NE...WITH A
GOOD CHANCE OR POSSIBLY LIKELY ACROSS THE SW PORTIONS BY SUNRISE
SUN. INCREASING MID-LEVEL DYNAMICS FROM A SERIES OF S/W MID-LEVEL
TROUGHS...PLENTY OF AVBL MOISTURE WITH 00Z SUNDAY NEARBY SOUNDINGS
AND MODEL PROGS INDICATING PWS OF 1.5 TO 1.75 INCHES...AND AS
MENTIONED EARLIER...SFC BASED BOUNDARIES WILL LIE ACROSS THE FA
ALLOWING FOR SFC BASED CONVERGENCE TO AID MORE ORGANIZED PCPN
DEVELOPMENT TO COMPLEMENT THE MID-LEVEL SUPPORT. LATEST MIN TEMPS
FORECAST OVERNIGHT LOOKING AOK AND SEE NO REASON TO FURTHER TWEAK
FROM EARLIER CHANGES.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...PRIMARY HEADLINES INCLUDE POTENTIAL FOR A
GOOD SOAKING OF RAIN...AND A FEW STRONG THUNDERSTORMS. MONDAY
APPEARS THE MORE OPTIMUM SET-UP FOR STRONG/SEVERE STORMS WITH MORE
ROBUST KINEMATIC FIELDS AND STRONGER LOW-LEVEL HEATING JUST AHEAD
OF A COLD FRONT. EXTENSIVE CLOUD CANOPY SUNDAY MAY IMPEDE
CONVECTION INITIATION/GROWTH. SUNDAY MEANWHILE OFFERS THE HIGHER
RAIN AMOUNTS AS COLUMN MOISTURE SURGES AS A WARM FRONT LIFTS N OF
THE AREA AND PRECIPITABLE WATERS SURGE TO 1.8". SEVERAL MCV
PERTURBATIONS ALOFT SWEPT NE IN WAKE OF THE WARM FRONT MAY SUSTAIN
SHOWER AND STORM CHANCES INTO SUNDAY NIGHT. CURRENT IR ANIMATIONS
SHOW COLD TOPS INDEED FLARING ALONG THE NORTHERN GULF OF MEXICO.
WPC QPF DEPICTIONS SHOW .75-1 INCH BASIN AVERAGES SUNDAY...AND
WITH CONVECTIVE ELEMENTS...SOME AREAS LIKELY TO RECEIVE GREATER
AMOUNTS. MONDAY LESS BASIN QPF BUT MORE POWERFUL STORMS IN THE
CARDS WITH MAXIMUMS RISING WELL INTO THE 80S AND PARTIAL SUNSHINE
AIDING INSOLATION AND CELL POPS. SPC PAINTS SLIGHT RISK FOR BOTH
LATE SUNDAY AND MONDAY. BALMY PERIOD OVERALL AND BEST GUESS ON
FRONTAL PASSAGE NOW SLATED AROUND OR AFTER DAYBREAK TUESDAY.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...AN ALMOST WINTERLIKE LOOKING UPPER PATTERN
FOR MOST OF THE PERIOD WITH A LARGE VORTEX IN THE VICINITY OF THE
GREAT LAKES. WESTERLY FLOW AROUND THIS FEATURE WILL KEEP MUCH OF THE
COLUMN DRY AND LEAD TO RAIN-FREE CONDITIONS LOCALLY. LOW LEVELS WILL
BE DRY AS WELL THROUGH SOME TIME WEDNESDAY AS HIGH PRESSURE BUILDS
IN FROM THE NORTHWEST. SOON THEREAFTER THIS HIGH MOVES OFFSHORE AND
SOME MOISTENING RETURN FLOW ENSUES. SOME GUIDANCE SHOWING THIS
CALLING FOR RAIN AS SOON AS THURSDAY BUT GIVEN THE AFOREMENTIONED
DOWNSLOPE FLOW STILL FEEL THAT THURSDAY NIGHT INTO FRIDAY IS THE
BETTER DAY TO INTRODUCE SOME RAIN CHANCES ESPECIALLY GIVEN THE
APPROACH OF A COLD FRONT. THOUGH THIS SURFACE BOUNDARY MAY LIE TO
OUR SOUTH ON SATURDAY SOME LOW LEVEL BAROCLINICITY PAIRED WITH MID
LEVEL VORT APPROACHING TO KEEP RAIN IN THE FORECAST.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...A MIXTURE OF VFR/MVFR THROUGH THE EARLY OVERNIGHT HOURS
DUE TO LOW CIGS AND PATCHY FOG...WITH CONDITIONS DETERIORATING TO
MVFR/IFR LATE OVERNIGHT AND THROUGH INTO SUNDAY WITH AN APPROACHING
FRONTAL SYSTEM.
OVERALL...VFR PREVAILS ACROSS THE AREA TONIGHT WITH LIGHT AND
VARIABLE WINDS AND INTERMITTENT LOW CIGS...AS WELL AS MID TO HIGH
CLOUDS AS SEEN FROM LATEST SATELLITE IMAGERY. OBSERVATIONS ARE ALSO
DEPICTING PATCHY FOG INLAND...JUST AT MARGINAL VFR/MVFR STATUS ATTM.
WITH ISOLATED LIGHT SHOWERS SLOWLY MOVING ACROSS THE
AREA...ANTICIPATE CONDITIONS TO DETERIORATE OVERNIGHT CREATING
WIDESPREAD MVFR/IFR DUE TO LOW CIGS AND AREAS OF FOG. AFTER
DAYBREAK...EXPECT EASTERLY WINDS AOB 12 KTS IN THE MORNING TO BECOME
EAST-SOUTHEAST BY AFTERNOON WITH GUSTS UP NEAR 20 KTS POSSIBLE WITH
A FRONTAL SYSTEM TO AFFECT THE AREA. A MIXTURE OF VFR/MVFR/IFR IS
ANTICIPATED AS SHOWERS AND ISOLATED THUNDERSTORMS...ALONG WITH LOW
CIGS AND PATCHY AREAS OF FOG MOVE THROUGHOUT THE AREA THROUGH THE
END OF THE VALID TAF PERIOD.
EXTENDED OUTLOOK...MVFR/IFR POSSIBLE INTO MONDAY WITH SHOWERS AND
ISOLATED THUNDERSTORMS. A COLD FRONT WILL PUSH THROUGH THE AREA
MONDAY NIGHT WITH SHOWERS POSSIBLE FOLLOWED BY MAINLY VFR CONDITIONS
TUESDAY. POSSIBLE SHOWERS RETURNING LATER IN THE WEEK.
&&
.MARINE... NEAR TERM /THROUGH TONIGHT/...
AS OF 130 AM SUNDAY...BASED ON OBSERVATIONS ALONG THE COAST I HAVE
BACKED WIND DIRECTIONS MORE NORTHERLY. NO OTHER SIGNIFICANT CHANGES
ARE NEEDED. DISCUSSION FROM 1030 PM FOLLOWS...
NO CHANGES TO THE WINDS FROM THE PREVIOUS UPDATE. WINDS TO BECOME NE-
E THROUGHOUT...AND INCREASE TO 10-15 KT...WITH THE HIGHER WIND SPEEDS
FROM CAPE FEAR NORTHWARD. THIS A RESULT OF THE BACKDOOR FRONTS
POSITIONING WITH ENOUGH TIGHTENING OF THE SFC PG AS RIDGING EXTENDS
SOUTH FROM THE NE STATES SFC HIGH. SIGNIFICANT SEAS WILL RUN 2 TO 4
FT...WITH THE 4 FOOTERS PRIMARILY ACROSS THE OUTER WATERS OFF CAPE
FEAR...AND NORTHWARD. DOMINANT PERIODS WILL RUN 8 TO 9 SECONDS IN
RESPONSE TO THE 2 TO 3 FOOT ESE GROUND SWELL. HAVE REDUCED THE POPS
FOR THIS EVENING BASED ON LATEST 88D TRENDS. SHOULD SEE POPS
INCREASE DURING THE PRE-DAWN SUN HRS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...EXERCISE CAUTION OR ADVISORY MARINE REGIME
ON TAP THIS PERIOD AS A FRONTAL SYSTEM APPROACHES AND WORSENS
LOCAL MARINE CONDITIONS. WAVE GROWTH HOWEVER MAY BE LIMITED SINCE
SE-S WIND FLOW HAS LIMITED STAYING TIME BEFORE WINDS GO SW EARLY
ON MONDAY. HAVE CAPPED SEAS AT 5 FEET SUNDAY FOR NOW WITH GUSTS TO
20 KT AHEAD OF THE COLD FRONT...SET TO CROSS THE WATERS TUESDAY
MORNING. SEVERAL STRONG TSTMS ARE POSSIBLE SUNDAY THROUGH THROUGH
EARLY TUESDAY AND SPECIAL MARINE WARNINGS MAY BE NEEDED AT TIMES.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...OFFSHORE/NORTHWESTERLY POST COLD FRONTAL
FLOW REGIME ON TUESDAY WILL GROW LIGHTER LATE IN THE DAY AND AT
NIGHT AS CENTER OF HIGH PRESSURE APPROACHES. THE CENTER OF HIGH
PRESSURE MOVES OFFSHORE BY WEDNESDAY EVENING. THIS WILL BRING A
PERIOD OF VERY LIGHT GRADIENT WHEREIN WINDS REMAIN UNDER 10 KNOTS
AND VEER IN DIRECTION FOR AN EXTENDED TIME UNTIL FINALLY SETTLING
ON SOUTHERLY BY WED EVE. SUCH LIGHT WINDS IN THE ABSENCE OF SWELL
ENERGY OUGHT TO BE GOOD FOR MINIMAL SEAS OF 2 FT OR LESS. THE HIGH
MOVES FURTHER OFFSHORE ON THURSDAY ALLOWING FOR A ONE CATEGORY
RISE IN WINDS AND A WAVES FORECAST RISING TO JUST THE 2 TO 3 FT
RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...DCH/TRA
SHORT TERM...MJC
LONG TERM...MBB
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1218 AM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 1218 AM CDT SUN APR 19 2015
NO CHANGES MADE TO THE PREVIOUS FORECAST.
UPDATE ISSUED AT 955 PM CDT SAT APR 18 2015
ALTHOUGH THE 01 UTC RAP/HRRR ARE OVERDOING THE QPF IN MOST
AREAS...THEY HAVE A GOOD HANDLE ON THE AREA OF PRECIPITATION AND
HAVE UTILIZED THIS BLEND FOR POPS THROUGH THE NIGHT AND INTO
SUNDAY. BEST PRECIPITATION CHANCES WILL REMAIN OVER THE SOUTHEAST
FORECAST AREA. EXPECT PRECIPITATION TO FILL IN OVER THE JAMES
RIVER VALLEY OVER THE NEXT FEW HOURS. PRECIPITATION BAND FROM
SOUTHWEST INTO NORTH CENTRAL NORTH DAKOTA WILL MOVE ACROSS CENTRAL
NORTH DAKOTA AS WELL...WITH BEST PRECIPITATION CHANCES OVER
BISMARCK THROUGH AROUND MIDNIGHT. PRECIPITATION IS EXPECTED TO
MOVE OUT OF THE JAMES RIVER VALLEY AROUND 12-14Z...LOWERED POPS
ACROSS THE AREA EARLY MORNING...THEN BUMPED THEM UP MID TO LATE
MORNING INTO THE AFTERNOON AS WRAP AROUND MOISTURE MOVES INTO THE
AREA ON THE BACK SIDE OF THE EXITING SYSTEM.
UPDATE ISSUED AT |748 PM CDT SAT APR 18 2015
QUICK UPDATE FOR POPS BASED ON LATEST RADAR...ALSO REMOVED
THUNDER OVER THE SOUTHWEST. HEAVIEST SHOWERS LOOK TO REMAIN OVER
THE FAR SOUTH CENTRAL AND INTO EASTERN NORTH DAKOTA THIS EVENING.
BAND MOVING EAST ACROSS THE CENTRAL FROM AROUND MINOT TO GARRISON
TO HEBRON SHOULD HELP MOISTEN THE ATMOSPHERE NEAR KBIS THIS
EVENING. SHOWERS IN THE FAR SOUTH CENTRAL MOVING TOWARD BISMARCK
ARE NOW DISSIPATING ON THE NORTHERN FRINGE. 19 APRIL 00 UTC
SOUNDING STILL SHOWS QUITE A BIT OF DRY AIR BELOW THE MID AND
UPPER LEVEL MOISTURE BEGINNING AROUND 10K FEET.
UPDATE ISSUED AT 638 PM CDT SAT APR 18 2015
UPPER LEVEL LOW OVER SOUTHEAST COLORADO WITH A SHORTWAVE TROUGH
LIFTING NORTH THROUGH WESTERN SOUTH DAKOTA IS PUSHING SHOWERS INTO
CENTRAL NORTH DAKOTA. A NORTHERN STREAM WAVE WITH MORE INSOLATION
TO WORK WITH IS PRODUCING A LINE OF POST FRONTAL SHOWERS AND
ISOLATED THUNDER OVER WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE
THUNDER IS LIMITED TO THE SOUTHWEST...AND WITH THE LOSS OF DAYTIME
HEATING...DO NOT EXPECT THUNDER TO CONTINUE MUCH LONGER. WILL KEEP
A MENTION THROUGH THE EARLY EVENING. EXPECT SHOWERS TO INCREASE
OVER SOUTH CENTRAL INTO EASTERN NORTH DAKOTA LATER THIS EVENING AS
THE SHORTWAVES LIFTING NORTH AND TRACKING EAST CONVERGE OVER
CENTRAL NORTH DAKOTA...AND THEN MOVE INTO BETTER MOISTURE AND
SURFACE SUPPORT AS THE SYSTEM MOVES INTO EASTERN NORTH DAKOTA LATE
TONIGHT. ADJUSTED POPS/SKY COVER BASED MAINLY ON SHORT TERM
CONSENSUS MODEL AND LATEST RADAR. OTHERWISE NO SIGNIFICANT CHANGES
FROM THE GOING FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 315 PM CDT SAT APR 18 2015
RAINFALL POTENTIAL THROUGH TONIGHT HIGHLIGHTS THE SHORT TERM
FORECAST.
AS OF 1930 UTC...A COLD FRONT WAS JUST ENTERING NORTHWEST NORTH
DAKOTA AND WILL CONTINUE TO PROPAGATE THROUGH CENTRAL NORTH DAKOTA
THIS EVENING. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WITH
WEAK INSTABILITY HAVE DEVELOPED ALONG THIS FRONT AND WILL APPROACH
THE HIGHWAY 83 CORRIDOR BY 01-02 UTC. AS CYCLOGENESIS OCCURS
ACROSS EASTERN SOUTH DAKOTA THROUGH THE NIGHT AND THE NORTHERN STREAM
WAVE ASSOCIATED WITH THE COLD FRONT PHASES WITH THE LOW TO THE
SOUTH...RAINFALL COVERAGE WILL INCREASE ACROSS CENTRAL NORTH
DAKOTA THROUGH THE EVENING AND NIGHT. THEREAFTER...A WINDY SUNDAY
IS FORECAST IN THE WAKE OF THE NOW DEEPENING LOW ACROSS MINNESOTA.
AT THIS TIME...WIND GUSTS APPEAR TO STAY BELOW ADVISORY CRITERIA
WITH 30 TO 35 KTS TO MIX IN COLD AIR ADVECTION. SCATTERED LIGHT
RAIN SHOWERS ARE ALSO EXPECTED IN WRAP AROUND MOISTURE WITH
PERHAPS A FEW SNOWFLAKES MIXING IN SUNDAY MORNING AS TEMPERATURES
FALL INTO THE MID 30S NORTHWEST AND NORTH CENTRAL. GIVEN GOOD
AGREEMENT...WILL WEIGH HEAVILY ON THE 16-18 UTC HRRR ITERATIONS
BLENDED TO THE GLOBAL 12 UTC DETERMINISTIC AND ENSEMBLE SUITE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CDT SAT APR 18 2015
WINDY WITH SCATTERED SHOWERS TO BEGIN THE EXTENDED...COOL AND DRY
THROUGH THE REMAINDER OF THE WEEK.
AS THE MAIN SURFACE LOW ENTERS NORTHERN MINNESOTA AND SOUTHERN
CANADA...MOISTURE SHOULD WRAP AROUND THE BACKSIDE...PROVIDING
NORTH DAKOTA WITH SOME SCATTERED LIGHT RAIN. THE HIGH RESOLUTION
SHORT TERM MODELS ARE A LITTLE MORE ROBUST WITH PRECIPITATION
COVERAGE THAN THE GLOBAL MODELS (ECMWF/GFS). WITH THE LOW
REMAINING NEARBY AND REMAINING UNDER THE INFLUENCE OF A FAVORABLE
JET STREAK...LIGHT SHOWERS HERE AND THERE AREN`T OUT OF THE
QUESTION THROUGH TUESDAY. GUSTY WINDS ARE EXPECTED THOUGH THE DAY
SUNDAY AND MONDAY AS THE PRESSURE GRADIENT TIGHTENS WITH THE
SURFACE LOW DEEPENING AND PROPAGATING TOWARD THE GREAT LAKES.
THESE GUSTY NORTHWEST WINDS WILL BE ADVECTING DRIER AIR INTO THE
AREA. THIS COULD CREATE RATHER CRITICAL FIRE CONDITIONS MONDAY AS
RELATIVE HUMIDITY DROPS BELOW 20 PERCENT.
THROUGH THE REMAINDER OF THE WORK WEEK...UPPER LOW SLOWLY WORKS
OFF TO THE EAST KEEPING NORTH/NORTHWESTERLY FLOW OVER OUR AREA.
WITH THE EXCEPTION OF ISOLATED SHOWERS EARLY THIS WEEK...DRY
WEATHER IS EXPECTED. TEMPERATURES WILL REMAIN A BIT BELOW
AVERAGE WITH READINGS IN THE 50S FOR HIGHS AND 20S/30S FOR LOWS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1218 AM CDT SUN APR 19 2015
WIDESPREAD RAIN IS EXPECTED TO CONTINUE THROUGH 06Z MONDAY.
KBIS/KJMS HAVE THE GREATEST CHANCES FOR RAIN WITH PERIODS OF MVFR
CONDITIONS POSSIBLE AT EACH OF THE TAF SITES.
&&
.FIRE WEATHER...
ISSUED AT 315 PM CDT SAT APR 18 2015
CRITICAL FIRE WEATHER CONDITIONS MAY BE POSSIBLE ON MONDAY...AND
THIS WILL NEED TO BE MONITORED. WHILE TEMPERATURES WILL ONLY BE IN
THE 50S...MINIMUM RELATIVE HUMIDITY LEVELS OF 15 TO 20 PERCENT AND
NORTHWEST WINDS OF 25 TO 35 MPH ARE POSSIBLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AC
SHORT TERM...AYD
LONG TERM...AJ
AVIATION...AC
FIRE WEATHER...AYD
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1135 PM CDT SAT APR 18 2015
.UPDATE...FOR AVIATION.
&&
.AVIATION...
06Z TAFS...BNA/CKV/CSV...A LOW PRESSURE SYSTEM AND WARM FRONT
WILL LIFT INTO MID TN OVERNIGHT BRINGING WIDESPREAD SHOWERS.
LOOK FOR -SHRA WITH MVFR CIGS/VSBYS TO DEVELOP AROUND 08Z...WITH
TEMPO IFR AND SOME LIFR 10Z-15Z. THE MAIN BAND OF MOISTURE WILL
LIFT NORTH OF MID TN BY 18Z. ANOTHER SYSTEM WILL APPROACH SUNDAY
AFTERNOON AND EVENING WITH SCATTERED TSRA...SOME POSSIBLY SEVERE.
13
&&
.PREV DISCUSSION... /ISSUED 1006 PM CDT SAT APR 18 2015/
UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO INCREASE SHWR/TSTM CHANCES
FROM SW TO NE REST OF EVENING AND OVERNIGHT. TWEAKED HRLY TEMP...DEWPOINT...
SKY...AND WIND SPEED/DIRECTION GRIDS ALSO. REMAINDER OF FORECAST
REMAINS ON TRACK.
PREV DISCUSSION... /ISSUED 530 PM CDT SAT APR 18 2015/
UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CURRENT REGIONAL
SFC OBS...SATELLITE...AND MOSAIC RADAR TRENDS ALONG WITH THE LATEST IN
SHORT RANGE MODEL CONSENSUS...THUS MAINTAINING ISO SHWRS/TSTMS THRU AT
LEAST THE MID EVENING HRS. BULK OF SHWR/TSTMS ACTIVITY SHOULD SPREAD FROM
THE SW TO THE NE ACROSS THE MID STATE AFTER MIDNIGHT.
PREV DISCUSSION.../ISSUED 351 PM CDT SAT APR 18 2015/
DISCUSSION...
AS AN UPPER TROUGH CENTERED OVER THE CENTRAL PLAINS MOVES EAST THIS
AFTERNOON AND OVERNIGHT IT WILL INFLUENCE SHOWERS AND THUNDERSTORMS
TO CONTINUE THEIR TREK NORTHWARD THROUGH MIDDLE TN. HRRR IS FORECASTING
SCATTERED AFTERNOON ACTIVITY TO MOVE INTO KENTUCKY AND ANOTHER
WAVE OF PRECIP TO SPREAD INTO MIDDLE TENNESSEE FROM THE SOUTH
BEFORE MIDNIGHT. PWAT VALUES WILL BE AROUND 1.5 INCHES FOR SEVERAL
HOURS OVERNIGHT TONIGHT. WITH THE GROUND ALREADY SATURATED FROM
THIS PAST WEEK`S RAINFALL...WE COULD SEE CREEKS AND STREAMS RISE
PRETTY QUICKLY DURING THE OVERNIGHT HOURS...WATCH FOR MINOR
FLOODING IN LOW LYING AREAS AND PONDING OF WATER ON ROADWAYS
OVERNIGHT. WHILE THERE MAY BE STORMS AROUND...NOT EXPECTING
ANYTHING STRONG OR SEVERE TONIGHT.
BETWEEN LATE SUNDAY MORNING AND EARLY AFTERNOON THE DEEPEST
MOISTURE WILL PUSH NORTH OF OUR AREA. LINGERING CLOUD
COVER...ESPECIALLY OVER THE NORTHEASTERN PORTION OF THE CWA MAY
INHIBIT INSTABILITY...BUT CLOUDS SHOULD BREAK UP ENOUGH DURING
THE AFTERNOON HOURS TO ALLOW FOR TEMPERATURES TO WARM INTO THE LOW
70S ALONG THE CUMBERLAND PLATEAU AND MID 70S ELSEWHERE. THIS
SHOULD BE WARM ENOUGH TO INITIATE ISOLATED TO SCATTERED STORMS
THROUGHOUT THE AFTERNOON. CURRENTLY SPC HAS THE MID-STATE IN A
SLIGHT RISK FOR SEVERE THUNDERSTORMS FOR SUNDAY AFTERNOON THROUGH
SUNDAY NIGHT. THE MAIN THREAT WITH ANY STORMS DURING THIS TIME
FRAME WILL BE DAMAGING WINDS AND HAIL. WE COULD SEE A COUPLE OF
ROUNDS OF THUNDERSTORMS OVERNIGHT SUNDAY NIGHT AHEAD OF A
SHORTWAVE AND ITS ASSOCIATED SURFACE LOW...WHICH STRENGTHEN OVER
SOUTHERN ILLINOIS AND HEAD NORTHEAST ON MONDAY.
THE FRONTAL PASSAGE ASSOCIATED WITH THE AFOREMENTIONED LOW WILL
OCCUR ON MONDAY AND WILL ALLOW FOR TEMPERATURES TO COOL INTO THE
40S OVERNIGHT MONDAY NIGHT. ALL PRECIP SHOULD PUSH EAST OF THE
TENNESSEE VALLEY TUESDAY NIGHT. A SURFACE HIGH MOVES IN ON TUESDAY
AND GIVES US A MUCH NEEDED DRY AND RELATIVELY COOL DAY WITH HIGH
TEMPERATURES IN THE MID 60S.
THE NEXT CHANCE OF PRECIP ENTERS THE FORECAST WEDNESDAY EVENING AS
A WEAK FRONT BRINGS A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH
THE AREA. COULD SEE A BREAK ON FRIDAY AS THAT MOISTURE PUSHES
SOUTH...THEN ANOTHER SURFACE LOW BRINGS ADDITIONAL THUNDERSTORM
CHANCES FRIDAY NIGHT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1239 AM CDT SUN APR 19 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...WIND SPEEDS ARE DECREASING AS TEMPERATURES COOL
TONIGHT. CLEAR SKIES WILL OPEN UP FOR SOME AREAS OF GROUND FOG TO
DEEPEN THROUGH THE NIGHT AND REFLECTED THAT IN THE TAFS. BRO/HRL
WILL LIKELY CONTINUE TO GET WORSE THROUGH THE NIGHT BUT MFE MAY
HOLD ON VFR MOST OF THE EVENING WITH A LARGER SFC DEWPOINT
DEPRESSION. DRIER AIR JUST ABOVE THE SURFACE SHOULD ALLOW
CONDITIONS TO IMPROVE PRETTY QUICKLY THROUGH MID MORNING. THERE IS
A CONDITIONAL RISK FOR CONVECTION MAINLY THIS AFTERNOON. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 633 PM CDT SAT APR 18 2015/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...A FEW SHOWERS HAVE ATTEMPTED TO GET GOING OVER THE
COASTAL COUNTIES OF DEEP SOUTH TEXAS...HOWEVER THEY HAVE LARGELY
FIZZLED OUT DUE TO A MORE STABLE ATMOSPHERE AIDED BY THE FRIDAY
EVENING/NIGHT CONVECTION. CURRENT SATELLITE IMAGERY DOESN/T SHOW
ANY CONVECTION IN THE VICINITY OF THE AERODROMES AND THIS HAS
BEEN REMOVED FROM THE PREVIOUS TAFS. SURFACE WINDS WILL LIKELY
REMAIN TOO STRONG OVERNIGHT TO ALLOW FOR SIGNIFICANT FORMATION OF
FOG...BUT A TEMPO HAS BEEN INCLUDED FOR LIGHT FOG DEVELOPMENT FOR
NEAR SUNRISE SUNDAY MORNING. PREVIOUSLY-LOWER CEILINGS HAVE BEEN
BEEN DUMPED IN FAVOR OF THE MID AND HIGH LEVEL CLOUDINESS
STREAMING OVERHEAD OUT OF NEIGHBORING MEXICO. OVERALL...VFR
SHOULD BE THE RULE THROUGH THE NEXT 24 HOURS.
PREV DISCUSSION... /ISSUED 255 PM CDT SAT APR 18 2015/
SHORT TERM.../NOW THROUGH SUNDAY NIGHT/...A LOW PRESSURE SYSTEM
CENTERED OVER EASTERN COLORADO IS MAINTAINING A BROAD AREA OF
DIFFLUENT FLOW ALOFT OVER SOUTH CENTRAL TEXAS. ALSO ...A VERY
ACTIVE SUB TROPICAL JET WITH SHORTWAVES WITHIN THE FLOW IS MOVING
ACROSS SOUTH TX UNDERNEATH THIS LOW. THIS WILL CONTINUE TO PRODUCE
NUMEROUS SHOWERS AND THUNDERSTORMS ALONG THE LOWER TEXAS GULF
WATERS NORTHEAST INTO THE NORTHWEST GULF COAST. THERE IS AN AREA
OF CONVECTION DEVELOPING ALONG A STATIONARY FRONT WHICH IS
INTERACTING WITH PLENTY OF DEEP LAYER MOISTURE AND INSTABILITY
POOLED ALONG IT. NEAR THE SURFACE DEW POINTS RANGE FROM 70 TO 75
DEGREES AND PRECIPITABLE WATER VALUES IN THE LAST KBRO 12Z
SOUNDING SHOWS 1.96 INCHES AND THE LATEST RAP MODEL RUN SHOWS
PWATS OF 1.5 TO 1.9 INCHES ESPECIALLY FROM HIDALGO COUNTY
NORTHEAST AND EAST TOWARDS THE COAST. IN ADDITION...THE A SLIGHT
BREAK IN THE CLOUDS IS ALLOWING FOR TEMPS TO WARM UP FOR THE NEXT
FEW HOURS RESULTING IN INCREASE INSTABILITY ACROSS THE AREA. THIS
WILL RESULT IN A CONTINUATION OF THE CONVECTION IN THE LATE
AFTERNOON THROUGH THE OVERNIGHT HOURS THROUGH MIDNIGHT. THE
CONVECTION WILL ALSO BE ENHANCE ALONG THE SIERRA MADRE AND MOVE
NORTHEAST WHICH WILL MAKE ITS WAY INTO STARR AND HIDALGO COUNTY
LATE EVENING INTO THE OVERNIGHT. THE MAIN THREAT WITH THESE STORMS
WILL BE VERY HEAVY DOWNPOURS PRODUCING FLOODING...STRONG DAMAGING
WINDS...HAIL AND FREQUENT CG LIGHTNING. INTO SUNDAY THE UPPER
LEVEL JET WILL MAKE ITS WAY INTO SOUTH TEXAS PROVIDING SUPPORT FOR
SOME CONVECTION TO DEVELOP SUNDAY AFTERNOON. EXPECT THE BEST
POTENTIAL TO REMAIN ALONG THE COAST DUE TO THE INSTABILITY IN THE
AREA. EXPECT A FEW OF THE STORMS TO BECOME SEVERE. THE CLOSED LOW
BECOMES AN OPEN WAVE AS IT MOVES NORTHEAST INTO THE GREAT LAKES
SUNDAY NIGHT PUSHING A COLD FRONT BEHIND IT ALONG THE CENTRAL
PLAINS. THE CONVECTION WILL BE ENHANCE EVEN MORE OVERNIGHT SUNDAY
ASSOCIATED TO THE BOUNDARY AS THE FRONT APPROACHES THE AREA. THE
FRONT WILL ARRIVED BY THE END OF THE SHORT TERM OVER THE NORTHERN
RANCHLANDS EARLY MONDAY MORNING.
LONG TERM.../MONDAY THROUGH SATURDAY/...THE CLOSED LOW THAT
HAS BEEN PLAUGING THE REGION WITH INTERMITTENT THUNDERSTORMS FOR
THE LAST SEVERAL DAYS OPENS UP AND MERGES WITH A SHARP SHORTWAVE
TROUGH UPPER TROUGH MOVING OUT OF CANADA. THE RESULT WILL BE A
LARGE SCALE UPPER TROUGH DEVELOPING MONDAY INTO TUESDAY FROM THE
NORTHERN PLAINS TO THE MIDWEST EXTENDING SOUTH INTO THE GULF
SOUTH. THIS SENDS A COLD FRONT THROUGH SOUTH TEXAS SUNDAY NIGHT
MOVING OFFSHORE THE LOWER TEXAS COAST AS EARLY AS SUNRISE MONDAY.
MODELS ARE IN GOOD AGREEMENT AND REMAIN VERY CONSISTENT WITH THE
EVOLUTION OF THE UPPER LEVEL AND SURFACE FEATURES. MODERATE TO
HIGH CONFIDENCE IN THE FORECAST THROUGH TUESDAY MAINTAINS A
LOWERING OF TEMPERATURES AND HIGHER CHANCES OF RAINFALL. THE
COOLING OF THE LOWER ATMOSPHERE, LOWER LAPSE RATES, WEAKENING
INSTABILITY WILL LIMIT THE THUNDERSTORM INTENSITY AND SEVERE
WEATHER PROBABILITIES GO WAY LOW. GFS MODEL SOUNDING CONTINUE TO
INDICATE THE BEST CHANCE OF THUNDER MONDAY MORNING AS THE FRONTAL
BOUNDARY PASSES THROUGH BUT AS THE COOLER SURFACE AIR SETTLES IN
THE INSTABILITY QUICKLY WEAKENS. ANY THUNDERSTORMS THAT LINGER
INTO THE MONDAY AFTERNOON AND EVENING WILL BE ELEVATED.
AS WE MOVE INTO TUESDAY AND THE REST OF THE WEEK THE FRONT
INITIALLY REMAINS STATIONARY NEAR OR JUST SOUTH OF THE REGION
KEEPING A MOIST EASTERLY FLOW AND POSSIBLY THE HIGHEST CHANCE OF
RAIN. BOTH GFS AND ECMWF INDICATE ON AVERAGE THAT TUESDAY WILL
HAVE THE BEST COVERAGE OF RAIN. THIS WILL ALSO KEEP TEMPERATURES
BELOW NORMAL.
AFTER TUESDAY FORECAST TRENDS DOWNWARD ON THE RAIN AND UP
WITH THE TEMPERATURES. THE FRONT EVENTUALLY DISSIPATES OR MOVES
BACK NORTH AS SHORTWAVE RIDGING BUILDS OVER WESTERN TEXAS WITH THE
NEXT UPPER TROUGH APPROACHING THE PACIFIC COAST. GFS AND ECMWF DO
LITTLE WITH THIS TROUGH AND IT LOOKS MUCH WEAKER THEN THE LAST FEW
TROUGHS. SOME PERTURBATIONS DO ADVANCE THROUGH THE TROUGH AND
RIDE ALONG STOUT SOUTHWESTERLY UPPER JET AND MAY SPARK SOME
AFTERNOON CONVECTION OVER THE SIERRA MADRE AND THEN DRIFT INTO OUR
CWA EACH AFTERNOON AND EVENING. THIS WILL BE INDICATED BY LOW
GRADE POPS EACH LATE DAY AND EVENING.
MARINE...NOW THROUGH SUNDAY NIGHT...THE SOUTHEAST WINDS WILL
REMAIN LIGHT TO VARIABLE WITH LOW SEAS ACROSS THE GULF WATERS. THE
MAIN CONCERNED THROUGH THE SHORT TERM WILL CONTINUE TO BE THE
CONVECTION OVER THE GULF. THERE IS ENOUGH INSTABILITY IN THE AREA
FROM A STATIONARY BOUNDARY PARALLEL TO THE COAST THAT WILL ENHANCE
MORE CONVECTION INCREASING LATE THIS AFTERNOON AND CONTINUE
OVERNIGHT. SUNDAY...THE POTENTIAL FOR CONVECTION WILL BEGIN TO
DEVELOP IN THE AFTERNOON AND CONTINUE OVERNIGHT AS A COLD FRONT IS
EXPECTED TO ARRIVED EARLY MONDAY INCREASING THE CHANCE OF RAIN
EVEN MORE AND SHIFTING WINDS NORTHERLY.
MONDAY THROUGH THURSDAY...COLD FRONT STILL ON TAP FOR EARLY
MONDAY AS HIGH PRESSURE BUILDS DOWN THE CENTRAL PLAINS AS A MID
LEVEL TROUGH DEEPENS INTO THE GULF SOUTH STATES. NORTHEAST WINDS
INCREASE APPROACHING SMALL CRAFT ADVISORY CONDITIONS MONDAY
AFTERNOON. SEAS TO RESPOND AND BUILD UPWARDS TO 6 FEET BY MONDAY
NIGHT. MODERATE NORTHEAST TO EAST WINDS PERSIST TUESDAY AS THE
FRONT BECOMES STATIONARY AND HIGH PRESSURE EXPANDS OVER THE
CENTRAL GULF. A RETURN TO SOUTHEAST WINDS WEDNESDAY WITH A GRADUAL
INCREASE THROUGH THE END OF THE WEEK IS EXPECTED. SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS MONDAY AND TUESDAY WITH
DECREASING COVERAGE MID TO LATE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 72 77 72 78 / 30 40 40 40
BROWNSVILLE 72 78 72 80 / 30 50 40 40
HARLINGEN 71 80 70 79 / 40 50 40 40
MCALLEN 72 80 71 79 / 30 50 40 40
RIO GRANDE CITY 71 80 68 78 / 30 40 50 60
SOUTH PADRE ISLAND 72 76 72 76 / 30 40 40 40
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/60
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1137 PM CDT SAT APR 18 2015
.DISCUSSION...
SEE 06Z AVIATION DISCUSSION.
&&
.AVIATION...
A LINE OF SHRA/TSRA WILL MOVE ACROSS THE NORTHERN TAF SITES BEFORE
06Z AND A PERIOD OF LIGHT RAIN WILL LIKELY PERSIST THROUGH 08S IN
THE WAKE OF THIS LINE. THINGS ARE A BIT MORE MUDDLED AS TO HOW FAR
SOUTH THIS LINE OF PRECIP WILL MOVE. LATEST HRRR SHOWS AN EASTWARD
PUSH TO THE NORTHERN HALF AND A SOUTHWARD PUSH TO THE WESTERN HALF
OF THE LINE. THE LINE IS STILL GENERATING WIND GUSTS BETWEEN 30-40
KNOTS SO FEEL IT IS BEST TO CARRY VCTS AND TEMPO A WIND GUST GROUP
AS FAR AS KHOU AND KSGR. THE COLD POOL/PRESSURE RISES LOOK STRONG
ENOUGH TO SUPPORT THE HRRR SOLUTION FURTHER SOUTH. WINDS WILL
LIKELY BECOME W-SW OVERNIGHT AND SW ON SUNDAY IN RESPONSE TO LOW
PRESSURE MOVING EAST ALONG THE RED RIVER. THE HRRR/GFS ADVERTISE A
TIGHT GRADIENT IN THE AFTN SO ADDED GUSTS TO THE NORTHERN TAF
SITES CLOSER TO THE TIGHTER GRADIENT. A COLD FRONT WILL APPROACH
SE TX ON SUN AFTN. NAM 12 FCST SOUNDINGS SHOW AN UNSTABLE
ATMOSPHERE OVER THE NORTH. JET DYNAMICS LOOK FAVORABLE WITH SE TX
LYING IN A LFQ BETWEEN 18-00Z. HAVE ADDED VCTS FOR KCXO
NORTHWARD. SOUNDINGS NOT QUITE AS UNSTABLE FOR THE HOUSTON
TERMINALS TOMORROW AFTN BUT THIS COULD CHANGE. ONE LAST
CAVEAT...IF SKIES CLEAR TONIGHT...WOULD EXPECT FOG TO DEVELOP BUT
JUST NOT SURE HOW MUCH CLEARING WILL OCCUR IN THE WAKE OF TONIGHTS
STORMS. 43
&&
.PREV DISCUSSION... /ISSUED 857 PM CDT SAT APR 18 2015/
DISCUSSION...
WATCHING A LINE OF STRONG/SEVERE STORMS HEADING TOWARD OUR WESTERN
COUNTIES THIS EVENING. AT THIS TIME...SPC WAS NOT PLANNING ON ISSUING
ANY WATCHES WITH THIS STORM COMPLEX. IF THE LATEST RUN OF THE HRRR
IS CORRECT...EXPECT THESE STORMS TO WEAKEN AS THEY MOVE INTO AND
ACROSS OUR AREA. 42
PREV DISCUSSION... /ISSUED 445 PM CDT SAT APR 18 2015/
DISCUSSION...
SENT OUT AN UPDATED FORECAST PACKAGE AND RAISED POPS AREA WIDE DUE
TO ONGOING/DEVELOPING CONVECTION ACROSS THE COASTAL COUNTIES AND
OFF THE COAST...AND FOR DEVELOPING STORMS OUT WEST THAT THE MODELS
HAVE MOVING INTO THE AREA THIS EVENING. SOME OF THE STORMS COULD
HAVE THE POTENTIAL TO BECOME STRONG OR SEVERE...WITH DAMAGING WINDS...
LARGE HAIL...AND LOCALLY HEAVY RAINFALL THE PRIMARY SEVERE WEATHER
THREATS. 42
MARINE...
AN UPPER LEVEL DISTURBANCE WILL GENERATE SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS ACROSS THE COASTAL WATERS THIS EVENING.
SOME STORMS COULD BE STRONG. OTHERWISE...ONSHORE FLOW WILL PERSIST
THROUGH SUNDAY. A COLD FRONT WILL PUSH OFF THE COAST SUNDAY NIGHT
WITH MODERATE OFFSHORE WINDS IN ITS WAKE. WINDS WILL DIMINISH AND
VEER BACK TO THE SOUTHEAST BY LATE TUESDAY NIGHT AS HIGH PRESSURE
PUSHES OFF TO THE EAST. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 63 85 56 75 54 / 60 20 10 10 20
HOUSTON (IAH) 64 85 61 78 57 / 50 20 20 10 10
GALVESTON (GLS) 69 81 66 77 66 / 50 20 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...42
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
147 AM EDT SUN APR 19 2015
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST TONIGHT ALLOWING CLOUDS FROM LOW
PRESSURE OVER THE TENNESSEE VALLEY TO SPREAD ACROSS THE REGION
OVERNIGHT. RAIN...HEAVY AT TIMES...WILL FALL SUNDAY INTO SUNDAY
NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF
SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL
CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 912 PM EDT SATURDAY
STILL A FEW DIURNAL SHOWERS ALONG THE BLUE RIDGE BUT THEY ARE
FADING FAST. WILL REMOVE POPS FOR THE REST OF THE EVENING...THEN
INCREASE POPS TOWARDS SUNRISE AS LOW PRESSURE ENTERS THE
TENNESSEE VALLEY. MINOR UPDATES TO OTHER GRIDS.
PREVIOUS DISCUSSION...
AS OF 300 PM EDT SATURDAY
WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS
IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS
BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY
FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS
AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR
POPS IN THE FORECAST.
ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW
LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT.
A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER
VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE
CRITERIA.
PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY
MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA
UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE
AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF
LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG
UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL
FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE
RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS
SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD
WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN
BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND
EAST...IF HIGHER QPF TRENDS CONTINUE.
CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN
PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS
IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
AS OF 335 PM EDT SATURDAY...
HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY
NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT
WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA
BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH
DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD
WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A
BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH
UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER
TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN
AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE
WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN
ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY
AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE
WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE
PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF
SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF
20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS
GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER
NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK
OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE
MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL
BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING
INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF
THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS
REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST
AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT
SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN
WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND
SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH
HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS
COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO
SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME.
UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER
CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A
FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE
TO 70 EVEN TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...
MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO
ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH
THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE
UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO
THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE
BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT
INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT
SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS
DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH
850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE
WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS
MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING
THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO
BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN
WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE
FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE
CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW
ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN
THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY
FROST/FREEZE CONCERN AT THIS POINT.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 145 AM EDT SUNDAY...
MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL
SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT
CEILINGS TO LOWER TO MVFR ON THE 09Z/5AM-16Z/11AM TIME RANGE.
A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT
WHICH MAY BRING WIND GUSTS TO 30 KTS TODAY. WITH A WEDGE OF HIGH
PRESSURE IN PLACE ALONG AND EAST OF THE BLUE RIDGE...AFTER SUNSET THESE
STRONG WINDS ARE NOT EXPECTED TO REACH THE SURFACE. HAVE LLWS IN
THE KDAN...KLWB AND KBCB TAFS AFTER 00Z/8PM.
A STRONG UPSLOPE FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE
REGION NORTH OF A STATIONARY FRONT TODAY. CEILINGS WILL LOWER TO
IFR LATE THIS AFTERNOON INTO THE EVENING AND WILL REMAIN LOW
OVERNIGHT.
EXTENDED AVIATION...
A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE.
THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS
UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING.
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.HYDROLOGY...
AS OF 330 PM EDT SATURDAY...
ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC
MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE
PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%.
THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM
THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN
THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW
3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD
DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS.
WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A
SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE
SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE
MODEL TRENDS OF INCREASING QPF WITH EACH RUN.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ015>017-032.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020.
WV...NONE.
&&
$$
SYNOPSIS...PH
NEAR TERM...PH/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/PC
HYDROLOGY...PH
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND MONDAY
ISSUED AT 327 AM CDT SUN APR 19 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SPLIT FLOW
OVER CENTRAL NORTH AMERICA EARLY THIS MORNING. IN THE SOUTHERN
STREAM...UPPER LEVEL LOW PRESSURE IS SPINNING OVER WESTERN
KANSAS/EASTERN COLORADO. AHEAD OF THIS FEATURE...SHOWERS AND
THUNDERSTORMS ARE OCCURRING FROM NEBRASKA TO LOUISIANA. EVEN
FURTHER NORTHEAST...MID-LEVEL MOISTURE TRANSPORT AND ILL-DEFINED
SHORTWAVES ARE ALSO CREATING SHOWERS AND A FEW THUNDERSTORMS FROM
WESTERN WISCONSIN INTO ILLINOIS. A COUPLE SPOTTY SHOWERS POPPED UP
SHORTLY AFTER MIDNIGHT OVER WOOD COUNTY TO THE DELLS...AND WILL HAVE
TO CARRY AN ISOLATED MENTION EARLY THIS MORNING ACROSS THE
I-39/ROUTE 51 CORRIDOR. IN THE NORTHERN STREAM...SHORTWAVE ENERGY
IS PROGRESSING EAST OVER THE NORTHWEST PLAINS. AS THESE FEATURES
MOVE EAST...PRECIP CHANCES AND TIMING ARE THE MAIN FORECAST CONCERNS.
TODAY...LOW PRESSURE OVER THE NORTHERN PLAINS WILL HEAD EAST WHILE
THE SOUTHERN STREAM LOW WILL LIFT NORTHEAST OVER THE CENTRAL
MISSISSIPPI VALLEY. WEAK SHORTWAVE ACTIVITY ROTATING ON THE EASTERN
PERIPHERY OF THE UPPER LOW OVER WESTERN KANSAS WILL LIFT NORTH
ACROSS THE WESTERN GREAT LAKES TODAY BUT INTO A MORE STABLE AND
DRIER AIRMASS. DESPITE THIS...THE HIGHER RES MODELS AND RUC DEPICT
SPOTTY SHOWERS DEVELOPING OVER CENTRAL AND NORTHEAST WISCONSIN THIS
MORNING WHICH BEAR SOME WEIGHT GIVEN THE SPOTTY SHOWERS POPPING UP
OVER THE DELLS AT THIS HOUR. AS A RESULT...QUITE DIFFICULT TO ADD
MUCH TEMPORAL RESOLUTION TO THE FORECAST THIS MORNING OTHER THAN
SAYING SLIGHT CHANCE OF A SHOWER. FORCING INCREASES OVER WESTERN
WISCONSIN DURING THE AFTERNOON WHEN A FGEN BAND MOVES ACROSS THAT
PART OF THE STATE. THE EASTERN EDGE OF THE INDUCED RAIN BAND WILL
LIKELY BE PUSHING INTO N-C WISCONSIN LATE IN THE AFTERNOON. AM
THINKING EASTERN WISCONSIN WILL REMAIN MOSTLY DRY DUE TO NE FLOW. THE
SLOWER ARRIVAL OF THE PRECIP WILL HELP TEMPERATURES RISE INTO THE
MID 60S OVER CENTRAL WI. CLOUD COVER AND EAST WINDS WILL SUPPORT
MUCH COOLER READINGS OVER EASTERN WI THOUGH.
TONIGHT...THE MEDIUM RANGE MODELS TRACK THE SOUTHERN STREAM SURFACE
LOW FROM CENTRAL ILLINOIS/INDIANA TO NORTHERN LOWER MICHIGAN. SOME
POSSIBILITY THAT THE LOW WILL TRACK WEST OF THIS LINE IN THE
MESOMODELS THOUGH. COMMA HEAD PRECIP FROM THIS LOW LOOKS TO MOVE
INTO NORTHEAST WISCONSIN BY MID TO LATE EVENING. MEANWHILE...RAIN
BAND ASSOCIATED WITH MID-LEVEL FGEN AHEAD OF THE NORTHERN STREAM
WAVE WILL SHIFT EAST THROUGH THE NIGHT ACROSS CENTRAL AND EASTERN
WISCONSIN. SEEMS LIKE A GOOD RECIPE FOR PERIODS OF RAIN ACROSS THE
REGION. LOWS RANGING FROM THE UPPER 30S NORTH TO MID 40S SOUTH.
MONDAY...THE FGEN RAIN BAND WILL GRADUALLY BE WEAKENING AS IT MOVES
EAST ACROSS EASTERN WISCONSIN DURING THE MORNING AND EXITS DURING
THE AFTERNOON. THE MID-LEVEL DRY SLOT WILL WORK OVERHEAD IN THE
WAKE OF THE RAIN DURING THE AFTERNOON AND MAY SEE A FEW PEAKS OF
SUNSHINE. OTHERWISE...BECOMING BREEZY WITH HIGHS IN THE MID 40S
NORTH TO LOW 50S SOUTH.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
ISSUED AT 327 AM CDT SUN APR 19 2015
CLOSED UPPER LOW WILL BRING UNSETTLED AND COOL CONDITIONS TO THE
REGION TUESDAY INTO WEDNESDAY. THE UPPER LOW WILL GRADUALLY PULL
AWAY THURSDAY AND FRIDAY...BUT CYCLONIC FLOW COULD STILL BRING A
SMALL CHANCE OF PRECIPITATION THURSDAY INTO FRIDAY ACROSS THE
FAR NORTH. DESPITE THE CALENDER STATING ITS LATE APRIL...SOME SNOW
IS IN THE FORECAST LATE AT NIGHT INTO THE MORNING HOURS. COULD BE SOME
MINOR ACCUMULATION ACROSS THE FAR NORTH TUESDAY MORNING AND AGAIN
WEDNESDAY MORNING.
BELOW NORMAL TEMPERATURES WILL CONTINUE INTO NEXT WEEKEND WITH DRY
CONDITIONS EXPECTED ON FRIDAY. ONLY MINOR CHANGES MADE TO PRECIPITATION
CHANCES AND TEMPERATURES DURING THE PERIOD.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1014 PM CDT SAT APR 18 2015
CLOUDS WILL CONTINUE TO THICKEN AND LOWER THROUGH THE
NIGHT AND EARLY SUNDAY MORNING AS LOW PRESSURE SYSTEMS APPROACH
FROM THE WEST AND SOUTH. RAIN IS EXPECTED TO BEGIN LATER SUNDAY
MORNING ACROSS THE WEST AND SUNDAY AFTERNOON ACROSS THE EASTERN
TAF SITES. TIMING OF THE RAIN SHOWERS IS A BIT TENUOUS AS THERE
REMAINS SIGNIFICANT DIFFERENCES BETWEEN THE NWP MODELS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......KURIMSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1123 PM MDT SAT APR 18 2015
.UPDATE...
ISSUED AT 1108 PM MDT SAT APR 18 2015
CLOUD TOPS CONTINUE TO WARM ON IR IMAGERY...AND THE BAND OF
MODERATE SNOW HAS SHIFTED EAST MORE INTO CENTRAL/SOUTHERN ALBANY
COUNTY AND WESTERN LARAMIE COUNTY...SO ALLOWED THE WINTER
HIGHLIGHTS TO EXPIRE.
UPDATE ISSUED AT 945 PM MDT SAT APR 18 2015
THE BAND OF MODERATE TO LOCALLY HEAVY SNOW CONTINUES TO SLOWLY
SHIFT EAST THIS EVENING...BUT PERHAPS SLIGHTLY SLOWER THAN
PREVIOUS THINKING. EARLIER ANALYSIS SUGGESTED A FEW STRONGER SNOW
SHOWERS WERE PERSISTING FROM THE NORTHERN LARAMIE RANGE SOUTHWEST
THROUGH THE ARLINGTON AREA AND ON UP INTO THE SNOWY RANGE AND
SOUTHERNMOST AREAS OF THE SIERRA MADRE MOUNTAINS. SHORT TERM
MODELS ALSO SUGGESTED THAT THE BAND WOULD MOVE SLOW TO THE EAST
THIS EVENING... SO FELT IT PRUDENT TO EXTEND THE WINTER STORM
WARNING AND ADVISORY FOR A FEW MORE HOURS AS SNOW WOULD CONTINUE
TO IMPACT THESE LOCATIONS. ENDED THE HEADLINES AT 11PM AS IR
IMAGERY IS SHOWING A RAPID WARMING OF CLOUD TOPS...AND MODELS
SUGGEST THE BAND WILL HAVE WEAKENED AND SHIFTED ENOUGH TO THE EAST
TO CANCEL ALL WINTER HEADLINES AT THIS TIME.
ALSO...ADDED AREAS OF FOG TO THE SUMMIT THROUGH MIDNIGHT AS
WEBCAMS SHOWED THE DEVELOPMENT OF FOG EARLIER...AND HRRR KEEPS
THE FOG AROUND THROUGH 11PM-12AM.
.UPDATE ISSUED AT 546 PM MDT SAT APR 18 2015
TORNADO WATCH HAS BEEN CANCELLED. CONDITIONS ARE NO LONGER
FAVORABLE FOR TORNADO DEVELOPMENT IN THE SOUTHERN NEBRASKA
PANHANDLE WITH THE BOUNDARY LAYER STABILIZING. A FEW
THUNDERSTORMS AREA STILL POSSIBLE OVER THE NEXT FEW HOURS INTO
SOUTHEAST WYOMING AND PANHANDLE BUT SEVERE WEATHER IS VERY
UNLIKELY. A ROUGE FUNNEL CLOUD AND SMALL HAIL STILL POSSIBLE FOR
THE NEXT HOUR OR SO.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 440 PM MDT SAT APR 18 2015
LOTS OF WEATHER CONCERNS OVER THE NEXT 12 HOURS. HEAVY SNOW
CONTINUES IN A NARROW BAND...MAINLY ACROSS EASTERN/CENTRAL CARBON
COUNTY...STRETCHING NORTHEAST INTO THE NORTHERN LARAMIE RANGE. ON
EITHER SIDE OF THE HEAVY BAND...MAINLY LOOKING AT LIGHT NON
ACCUMULATING SNOW OR RAIN. THIS WILL CONTINUE TO BE THE CASE UNTIL
LATE THIS EVENING WHEN THE DEFORMATION AXIS BEGINS TO SHIFT EAST
AS THE NORTHWEST FLOW KICKER PUSHES THE UPPER LOW INTO THE PLAINS.
THE BAND WILL SHIFT EAST LATE THIS EVENING INTO THE OVERNIGHT
HOURS BUT IT WILL ALSO WEAKEN SUBSTANTIAL WILL LITTLE IN THE WAY
OF ADDITION MEASURABLE PRECIPITATION AFTER MIDNIGHT ANYWHERE IN
THE FORECAST AREA.
SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER THE PLAINS. A
TORNADO WATCH IS IN EFFECT FOR MORRILL AND CHEYENNE COUNTY IN THE
SOUTHERN NEBRASKA PANHANDLE UNTIL 8 PM MDT. BASED ON RADAR TRENDS
AND CURRENT ATMOSPHERIC ENVIRONMENT...ANY TORNADO THREAT IS
RAPIDLY DECREASING. CURRENT SHOWER ACTIVITY WILL RAPIDLY
STABILIZE THE BOUNDARY LAYER. ALSO...LIMITED SHEAR IS ONLY
SUPPORTIVE OFF VERY SHORT LIVED AND WEAK TORNADIC ACTIVITY. WOULD
NOT BE SURPRISED TO SEE A FEW FUNNEL CLOUD REPORTS WITH
DEVELOPING SHOWERS AND THUNDERSTORMS AS THE OVERALL ENVIRONMENT IS
MORE SUPPORTIVE OF FUNNEL CLOUDS BUT THAT TOO WILL QUICKLY WANE
OVER THE NEXT FEW HOURS.
ANOTHER CONCERN FOR TONIGHT IS NORTHERN WINDS WHICH WILL RAMP UP
THIS EVENING INTO THE OVERNIGHT AS A COLD FRONT MOVES ACROSS THE
AREA. COULD SEE A SHORT PERIOD OF NASTY WINTER CONDITIONS...MAINLY
INTO THE SOUTHERN LARAMIE RANGE AND CHEYENNE AS THE SNOW BAND
SHIFTS EAST AND INTERACTS WITH STRONG GUSTY NORTHERN WINDS. NAM
AND GFS BUFKIT SOUNDINGS AROUND MIDNIGHT SHOWING 45 TO 50 KT
WINDS AT CHEYENNE NOT TOO FAR OFF THE SURFACE. VERY WELL COULD SEE
A 3 TO 4 HOUR PERIOD WITH LOW VISIBILITIES DUE TO FALLING SNOW AND
GUSTY WINDS. FORTUNATELY THIS WILL BE SHORT LIVED IF IT THIS
COMBINATIONS DOES INDEED OCCUR. ALSO WINDS SPEEDS WILL APPROACH
WIND ADVISORY LEVELS INTO THE NEBRASKA PANHANDLE LATER TONIGHT
AND INTO SUNDAY AFTERNOON. DID NOT ISSUE ANY WIND HEADLINES GIVEN
WINTER WEATHER AND CONVECTIVE HEADLINES...BUT A WIND ADVISORY MAY
BE NEEDED EVENTUALLY.
QUIETER WEATHER ACROSS THE AREA SUNDAY WITH THE UPPER LOW OUT OF
THE PICTURE. KEPT SOME LOW POPS GOING ACROSS THE WEST DURING THE
DAY SUNDAY...BUT IT IS LOOKING LESS AND LESS LIKELY FOR ANY
MEASURABLE PRECIPITATION FOR MOST OF SUNDAY. MAIN CHANCES WILL BE
WITH NORTHERN STREAM SHORTWAVE AND UPPER LEVEL JET ENERGY WHICH
SHOULD IMPACT THE SNOWY AND SIERRA MADRES SUNDAY NIGHT.
ACCUMULATIONS WILL BE MINIMAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 250 PM MDT SAT APR 18 2015
MEDIUM TO LONG RANGE MODELS IN FAIR AGREEMENT THROUGH THE MIDDLE
OF NEXT WEEK...WITH SOME DISAGREEMENT REGARDING THE TRACK AND
EVOLUTION OF A DEVELOPING LOW PRESSURE SYSTEM LIFTING NORTHEAST
ACROSS THE CENTRAL AND SOUTHERN ROCKY MOUNTAINS BY THURSDAY AND
FRIDAY. FOR EARLY NEXT WEEK...ALL MODELS SHOW NORTHWEST FLOW
INITIALLY WITH RELATIVELY DRY CONDITIONS LASTING INTO EARLY
WEDNESDAY. A WEAK SHORTWAVE TROUGH WILL PUSH ACROSS THE REGION
EMBEDDED IN THE NORTHWEST FLOW...BUT OUTSIDE OF SOME MOUNTAIN/HIGH
VALLEY RAIN AND SNOW SHOWERS...DO NOT EXPECT ANYTHING SIGNIFICANT
WITH HIGH TEMPERATURES ABOUT 10 TO 15 DEGREES COOLER THAN SEASONAL
AVERAGES. TEMPERATURES WILL FINALLY MODERATE SOME BY TUES AND
ESPECIALLY INTO WED...BACK INTO THE UPPER 50S TO UPPER 60S TO THE
EAST OF THE LARAMIE RANGE. A SURFACE HIGH WILL BUILD OVER THE
GREAT PLAINS LATE WEDNESDAY AND ON THURSDAY...RESULTING IN WINDS
VEERING INTO THE EAST AND SOUTHEAST. KEPT TSTORMS IN THE FORECAST
FOR THURSDAY WEST OF THE LARAMIE RANGE...BUT KEPT SHOWERS FURTHER
EAST DUE TO A PERSISTENT LLVL STRATUS DECK.
MODELS STRUGGLING WITH A SHORTWAVE DISTURBANCE LIFTING NORTHEAST
OUT OF ARIZONA THURSDAY NIGHT. 12Z GFS ATTEMPTS TO FORM A CLOSED
LOW ACROSS THE NORTH CENTRAL PLAINS OF COLORADO BY EARLY
FRIDAY...WITH PRECIP EXTENDING INTO THE I80 CORRIDOR OF SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THE ECMWF ON THE OTHER HAND IS MUCH
FURTHER SOUTH...MAINLY SHOWING THE FEATURE ACROSS NORTHERN NEW
MEXICO LIFTING NORTHEAST INTO KANSAS BY FRIDAY. KEPT A 20 TO 30
PERCENT CHANCE OF RAIN AND HIGH ELEVATION SNOW FOR FRIDAY AND EARLY
SATURDAY MORNING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
AREAS OF MVFR AND IFR CIGS WILL AFFECT MOST TERMINALS OVERNIGHT WITH
SOME RAIN AND SNOW EARLY IN THE PERIOD. GUSTY SFC WINDS EXPECTED
ESPECIALLY OVER THE PLAINS TONIGHT AND SUNDAY. CIGS IMPVG DURING
THE DAY SUNDAY.
&&
.FIRE WEATHER...
ISSUED AT 250 PM MDT SAT APR 18 2015
SHOWERS AND THUNDERSTORMS WILL END ACROSS ACROSS THE PLAINS
TONIGHT WITH SNOW ENDING OVER HIGHER ELEVATIONS OF WYOMING AS THE
UPPER LEVEL DISTURBANCE SHIFTS EAST INTO THE CENTRAL PLAINS.
WARMING TREND THROUGH MID WEEK BUT GENERALLY ON THE COOLER SIDE
AND DRY. NEXT CHANCE FOR WIDESPREAD PRECIPITATION IS LATE NEXT
WEEK...MAYBE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RJM
SHORT TERM...SML
LONG TERM...TJT
AVIATION...RE
FIRE WEATHER...SML
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1108 PM MDT SAT APR 18 2015
.UPDATE...
ISSUED AT 1108 PM MDT SAT APR 18 2015
CLOUD TOPS CONTINUE TO WARM ON IR IMAGERY...AND THE BAND OF
MODERATE SNOW HAS SHIFTED EAST MORE INTO CENTRAL/SOUTHERN ALBANY
COUNTY AND WESTERN LARAMIE COUNTY...SO ALLOWED THE WINTER
HIGHLIGHTS TO EXPIRE.
UPDATE ISSUED AT 945 PM MDT SAT APR 18 2015
THE BAND OF MODERATE TO LOCALLY HEAVY SNOW CONTINUES TO SLOWLY
SHIFT EAST THIS EVENING...BUT PERHAPS SLIGHTLY SLOWER THAN
PREVIOUS THINKING. EARLIER ANALYSIS SUGGESTED A FEW STRONGER SNOW
SHOWERS WERE PERSISTING FROM THE NORTHERN LARAMIE RANGE SOUTHWEST
THROUGH THE ARLINGTON AREA AND ON UP INTO THE SNOWY RANGE AND
SOUTHERNMOST AREAS OF THE SIERRA MADRE MOUNTAINS. SHORT TERM
MODELS ALSO SUGGESTED THAT THE BAND WOULD MOVE SLOW TO THE EAST
THIS EVENING... SO FELT IT PRUDENT TO EXTEND THE WINTER STORM
WARNING AND ADVISORY FOR A FEW MORE HOURS AS SNOW WOULD CONTINUE
TO IMPACT THESE LOCATIONS. ENDED THE HEADLINES AT 11PM AS IR
IMAGERY IS SHOWING A RAPID WARMING OF CLOUD TOPS...AND MODELS
SUGGEST THE BAND WILL HAVE WEAKENED AND SHIFTED ENOUGH TO THE EAST
TO CANCEL ALL WINTER HEADLINES AT THIS TIME.
ALSO...ADDED AREAS OF FOG TO THE SUMMIT THROUGH MIDNIGHT AS
WEBCAMS SHOWED THE DEVELOPMENT OF FOG EARLIER...AND HRRR KEEPS
THE FOG AROUND THROUGH 11PM-12AM.
.UPDATE ISSUED AT 546 PM MDT SAT APR 18 2015
TORNADO WATCH HAS BEEN CANCELLED. CONDITIONS ARE NO LONGER
FAVORABLE FOR TORNADO DEVELOPMENT IN THE SOUTHERN NEBRASKA
PANHANDLE WITH THE BOUNDARY LAYER STABILIZING. A FEW
THUNDERSTORMS AREA STILL POSSIBLE OVER THE NEXT FEW HOURS INTO
SOUTHEAST WYOMING AND PANHANDLE BUT SEVERE WEATHER IS VERY
UNLIKELY. A ROUGE FUNNEL CLOUD AND SMALL HAIL STILL POSSIBLE FOR
THE NEXT HOUR OR SO.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 440 PM MDT SAT APR 18 2015
LOTS OF WEATHER CONCERNS OVER THE NEXT 12 HOURS. HEAVY SNOW
CONTINUES IN A NARROW BAND...MAINLY ACROSS EASTERN/CENTRAL CARBON
COUNTY...STRETCHING NORTHEAST INTO THE NORTHERN LARAMIE RANGE. ON
EITHER SIDE OF THE HEAVY BAND...MAINLY LOOKING AT LIGHT NON
ACCUMULATING SNOW OR RAIN. THIS WILL CONTINUE TO BE THE CASE UNTIL
LATE THIS EVENING WHEN THE DEFORMATION AXIS BEGINS TO SHIFT EAST
AS THE NORTHWEST FLOW KICKER PUSHES THE UPPER LOW INTO THE PLAINS.
THE BAND WILL SHIFT EAST LATE THIS EVENING INTO THE OVERNIGHT
HOURS BUT IT WILL ALSO WEAKEN SUBSTANTIAL WILL LITTLE IN THE WAY
OF ADDITION MEASURABLE PRECIPITATION AFTER MIDNIGHT ANYWHERE IN
THE FORECAST AREA.
SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER THE PLAINS. A
TORNADO WATCH IS IN EFFECT FOR MORRILL AND CHEYENNE COUNTY IN THE
SOUTHERN NEBRASKA PANHANDLE UNTIL 8 PM MDT. BASED ON RADAR TRENDS
AND CURRENT ATMOSPHERIC ENVIRONMENT...ANY TORNADO THREAT IS
RAPIDLY DECREASING. CURRENT SHOWER ACTIVITY WILL RAPIDLY
STABILIZE THE BOUNDARY LAYER. ALSO...LIMITED SHEAR IS ONLY
SUPPORTIVE OFF VERY SHORT LIVED AND WEAK TORNADIC ACTIVITY. WOULD
NOT BE SURPRISED TO SEE A FEW FUNNEL CLOUD REPORTS WITH
DEVELOPING SHOWERS AND THUNDERSTORMS AS THE OVERALL ENVIRONMENT IS
MORE SUPPORTIVE OF FUNNEL CLOUDS BUT THAT TOO WILL QUICKLY WANE
OVER THE NEXT FEW HOURS.
ANOTHER CONCERN FOR TONIGHT IS NORTHERN WINDS WHICH WILL RAMP UP
THIS EVENING INTO THE OVERNIGHT AS A COLD FRONT MOVES ACROSS THE
AREA. COULD SEE A SHORT PERIOD OF NASTY WINTER CONDITIONS...MAINLY
INTO THE SOUTHERN LARAMIE RANGE AND CHEYENNE AS THE SNOW BAND
SHIFTS EAST AND INTERACTS WITH STRONG GUSTY NORTHERN WINDS. NAM
AND GFS BUFKIT SOUNDINGS AROUND MIDNIGHT SHOWING 45 TO 50 KT
WINDS AT CHEYENNE NOT TOO FAR OFF THE SURFACE. VERY WELL COULD SEE
A 3 TO 4 HOUR PERIOD WITH LOW VISIBILITIES DUE TO FALLING SNOW AND
GUSTY WINDS. FORTUNATELY THIS WILL BE SHORT LIVED IF IT THIS
COMBINATIONS DOES INDEED OCCUR. ALSO WINDS SPEEDS WILL APPROACH
WIND ADVISORY LEVELS INTO THE NEBRASKA PANHANDLE LATER TONIGHT
AND INTO SUNDAY AFTERNOON. DID NOT ISSUE ANY WIND HEADLINES GIVEN
WINTER WEATHER AND CONVECTIVE HEADLINES...BUT A WIND ADVISORY MAY
BE NEEDED EVENTUALLY.
QUIETER WEATHER ACROSS THE AREA SUNDAY WITH THE UPPER LOW OUT OF
THE PICTURE. KEPT SOME LOW POPS GOING ACROSS THE WEST DURING THE
DAY SUNDAY...BUT IT IS LOOKING LESS AND LESS LIKELY FOR ANY
MEASURABLE PRECIPITATION FOR MOST OF SUNDAY. MAIN CHANCES WILL BE
WITH NORTHERN STREAM SHORTWAVE AND UPPER LEVEL JET ENERGY WHICH
SHOULD IMPACT THE SNOWY AND SIERRA MADRES SUNDAY NIGHT.
ACCUMULATIONS WILL BE MINIMAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 250 PM MDT SAT APR 18 2015
MEDIUM TO LONG RANGE MODELS IN FAIR AGREEMENT THROUGH THE MIDDLE
OF NEXT WEEK...WITH SOME DISAGREEMENT REGARDING THE TRACK AND
EVOLUTION OF A DEVELOPING LOW PRESSURE SYSTEM LIFTING NORTHEAST
ACROSS THE CENTRAL AND SOUTHERN ROCKY MOUNTAINS BY THURSDAY AND
FRIDAY. FOR EARLY NEXT WEEK...ALL MODELS SHOW NORTHWEST FLOW
INITIALLY WITH RELATIVELY DRY CONDITIONS LASTING INTO EARLY
WEDNESDAY. A WEAK SHORTWAVE TROUGH WILL PUSH ACROSS THE REGION
EMBEDDED IN THE NORTHWEST FLOW...BUT OUTSIDE OF SOME MOUNTAIN/HIGH
VALLEY RAIN AND SNOW SHOWERS...DO NOT EXPECT ANYTHING SIGNIFICANT
WITH HIGH TEMPERATURES ABOUT 10 TO 15 DEGREES COOLER THAN SEASONAL
AVERAGES. TEMPERATURES WILL FINALLY MODERATE SOME BY TUES AND
ESPECIALLY INTO WED...BACK INTO THE UPPER 50S TO UPPER 60S TO THE
EAST OF THE LARAMIE RANGE. A SURFACE HIGH WILL BUILD OVER THE
GREAT PLAINS LATE WEDNESDAY AND ON THURSDAY...RESULTING IN WINDS
VEERING INTO THE EAST AND SOUTHEAST. KEPT TSTORMS IN THE FORECAST
FOR THURSDAY WEST OF THE LARAMIE RANGE...BUT KEPT SHOWERS FURTHER
EAST DUE TO A PERSISTENT LLVL STRATUS DECK.
MODELS STRUGGLING WITH A SHORTWAVE DISTURBANCE LIFTING NORTHEAST
OUT OF ARIZONA THURSDAY NIGHT. 12Z GFS ATTEMPTS TO FORM A CLOSED
LOW ACROSS THE NORTH CENTRAL PLAINS OF COLORADO BY EARLY
FRIDAY...WITH PRECIP EXTENDING INTO THE I80 CORRIDOR OF SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THE ECMWF ON THE OTHER HAND IS MUCH
FURTHER SOUTH...MAINLY SHOWING THE FEATURE ACROSS NORTHERN NEW
MEXICO LIFTING NORTHEAST INTO KANSAS BY FRIDAY. KEPT A 20 TO 30
PERCENT CHANCE OF RAIN AND HIGH ELEVATION SNOW FOR FRIDAY AND EARLY
SATURDAY MORNING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH SUNDAY AFTERNOON)
A BAND OF SNOW AND RAIN WILL REMAIN OVER CONVERSE...CARBON...AND
ALBANY COUNTIES THIS EVENING...AND THEN WILL RAPIDLY PUSH
SOUTHEAST NEAR A COLD FRONT...WHICH WILL PUSH SOUTHWARD TONIGHT. SCATTERED
TSTORMS HAVE DEVELOPED NEAR KSNY AND JUST EAST OF KCYS THIS
AFTERNOON. THESE TSTORMS WILL GRADUALLY MOVE NORTHWEST THIS
AFTERNOON AND THIS EVENING. SMALL HAIL AND BRIEF HEAVY RAINFALL IS
EXPECTED. A MORE STABLE AIRMASS WILL PUSH INTO THE REGION ON
SUNDAY BEHIND A WEAK COLD FRONT...RESULTING IN LOW PRECIPITATION
CHANCES ACROSS MOST OF THE FORECAST AREA. HOWEVER...IT WILL BE
WINDY BEHIND THIS FRONT WITH NORTH WINDS BETWEEN 20 TO 30 KNOTS
EAST OF THE LARAMIE RANGE.
&&
.FIRE WEATHER...
ISSUED AT 250 PM MDT SAT APR 18 2015
SHOWERS AND THUNDERSTORMS WILL END ACROSS ACROSS THE PLAINS
TONIGHT WITH SNOW ENDING OVER HIGHER ELEVATIONS OF WYOMING AS THE
UPPER LEVEL DISTURBANCE SHIFTS EAST INTO THE CENTRAL PLAINS.
WARMING TREND THROUGH MID WEEK BUT GENERALLY ON THE COOLER SIDE
AND DRY. NEXT CHANCE FOR WIDESPREAD PRECIPITATION IS LATE NEXT
WEEK...MAYBE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RJM
SHORT TERM...SML
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...SML
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
901 AM EDT SUN APR 19 2015
...INCREASING POTENTIAL FOR STRONG/SEVERE STORMS THIS AFTERNOON...
.UPDATE...
INTERESTING ENVIRONMENTAL SETUP FOR THIS AFTERNOON IN OUR AREA.
INITIAL PRECIPITATION AREA EXITING TO NORTHEAST WITH INITIAL
SHORTWAVE SEEN ON WATER VAPOR IMAGERY. VISIBLE IMAGERY SHOWING
AREA OF CLEARING...JUST SOME HIGH CLOUDS...SOUTHWEST GA/NW AND
WCTRL FL WHICH WILL SHIFT EASTWARD AHEAD OF DEVELOPING CONVECTION
OVER GULF OF MEX. THUS SHOULD ALLOW SURFACE TEMPS TO RISE INTO
80-85 RANGE ACROSS FCST AREA...DESTABILIZING AIRMASS.
GENERALLY FOLLOWING THE HRRR...ANTICIPATE INCREASE/UPSCALE IN
CONVECTION W OF FORECAST AREA INTO NRN GULF THROUGH THE MORNING
APPROACHING OUR WRN COUNTIES TOWARD 18Z...AHEAD OF A WELL-DEFINED
SHORTWAVE SEEN ON WATER VAPOR. MODELS BRING SHORT WAVE OVER OUR
FORECAST AREA LATE THIS AFTERNOON.
MEANWHILE...MORNING SOUNDINGS SUGGEST POTENTIAL FOR EAST COAST
SEA BREEZE TO MAKE SOME PROGRESS INLAND...PERHAPS TO I-95 CORRIDOR
MID AFTERNOON WHILE WEST COAST SEA BREEZE MOVES EASTWARD DURING
AFTERNOON.
LATEST HRRR SUGGESTS TWO AREAS OF CONCERN...FIRST IS AN ORGANIZED
LINE...OR LINE SEGMENTS...MOVING NORTHEAST ACROSS OUR WESTERN
COUNTIES 18Z-21Z...AND EASTERN COUNTIES 21Z-00Z. PRIMARY THREAT
WILL BE LOCALLY SEVERE WINDS WITH BOWING SEGMENTS GIVEN UNSTABLE
AIRMASS AND DECENT LOW-LEVEL LAPSE RATES. FEEL THE BEST POTENTIAL
FOR SEVERE WEATHER FROM THIS PORTION WILL BE SUWANNEE VALLEY
REGION OF NE FL...AND MUCH OF SE GA. SUFFICIENT LOW-LEVEL
SHEAR/HELICITY SUCH THAT ISOLATED TORNADOES WILL BE POSSIBLE. A
TORNADO WATCH IS ISSUED WEST OF OUR AREA...AND WOULD ANTICIPATE
EASTWARD EXPANSION THIS AFTERNOON. HRRR SUGGESTS WEAKENING OF
THIS ACTIVITY AS IT MOVES EAST OVER OUR FORECAST AREA...BUT
UNCERTAIN OF THIS SOLUTION GIVEN WELL DEFINED SHORT WAVE AND
DIFFLUENCE IN RIGHT-REAR QUAD SUPPORTING CONVECTION.
A SECOND AREA OF CONCERN IS ASSOCIATED WITH EASTWARD MOVING WEST
COAST SEA BREEZE...WHICH HRRR SUGGESTS COULD INITIATE DISCRETE
CELLULAR CONVECTION AFTER 18Z OVER EASTERN PORTION OF NE FL...
PARTICULARLY LATER IN AFTERNOON AS IT CONVERGES WITH EAST COAST
SEA BREEZE. COMBINATION OF CAPE VALUES 2000-3000 J/KG AND DEEP
LAYER SHEAR VALUES NEAR 40KTS SUGGEST SOME SUPERCELL STRUCTURES
POSSIBLE...WITH POTENTIAL FOR ISOLATED STRONG/SEVERE STORMS.
PRIMARY THREAT HERE WOULD BE STRONG WINDS AND HAIL...BUT CANNOT
RULE OUT ISOLATED TORNADO ESPECIALLY FAR EASTERN COUNTIES IF FLOW
IS BACKED NEAR EAST COAST SEA BREEZE.
&&
.AVIATION...VFR CONDITIONS THRU EARLY AFTERNOON...WITH POTENTIAL
FOR MVFR CONDITIONS ASSOCIATED WITH SCATTERED TO NUMEROUS TSRA.
&&
.MARINE...NO SIGNIFICANT CHANGES PLANNED IN NEXT CWF ISSUANCE.
WINDS WILL BECOME SOUTH TODAY WITH 2-4 FT SEAS. SHOWERS/T-STORMS
WILL INCREASE DURING THE AFTERNOON INTO THE EARLY EVENING HOURS.
RIP CURRENTS: MODERATE RISK TODAY DUE TO LINGERING SWELL.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 82 65 82 58 / 80 30 30 20
SSI 79 68 81 64 / 80 30 30 20
JAX 84 67 84 62 / 80 30 30 20
SGJ 82 68 82 65 / 70 30 40 20
GNV 85 67 83 64 / 70 20 40 20
OCF 86 67 83 65 / 60 20 40 20
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
WOLF/SANDRIK/WALKER
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1121 AM EDT SUN APR 19 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT INTO THE AREA TODAY...ACCOMPANIED BY AN UPPER
LEVEL DISTURBANCE. A COLD FRONT WILL APPROACH THE AREA MONDAY...
MOVING OFFSHORE MONDAY NIGHT. HIGH PRESSURE WILL BUILD IN TUESDAY
THROUGH THURSDAY. A WEAK COLD FRONT WILL DROP THROUGH THE AREA
THURSDAY NIGHT...THEN A STORM SYSTEM WILL AFFECT THE REGION NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATE THIS MORNING...THE WARM FRONT PRECIPITATION THAT HAD
BLOSSOMED EARLIER THIS MORNING ACROSS SOUTHEAST GEORGIA HAS
DISSIPATED PRETTY RAPIDLY AS IT LIFTS TO THE NORTHEAST. AS
SUCH...THE REST OF THE MORNING WILL BE RELATIVELY QUIET AHEAD OF
THE MAIN FORECAST PROBLEM WHICH IS THE LARGE AREA OF CONVECTION
CURRENTLY IMPACTING MUCH OF ALABAMA/GEORGIA/FLORIDA.
OVERALL...THERE WILL BE LIMITED PRECIPITATION COVERAGE OUT AHEAD
OF THE APPROACHING LINE OTHER THAN SCATTERED DISCRETE
SHOWERS/THUNDERSTORMS THAT SHOULD DEVELOP RIGHT AS THE LINE PUSHES
INTO THE WESTERN ZONES. CURRENTLY...THE RECENT RUNS OF THE HRRR
SEEMS TO HAVE AN EXCELLENT HANDLE ON THE POSITION OF THE
CONVECTION AND ITS AFTERNOON PROGRESSION SEEMS QUITE REASONABLE.
REGARDING TIMING...THE HRRR IS RUNNING ABOUT AN HOUR OR TWO ON
THE SLOW SIDE SO WE THINK THE LINE OF STORMS WILL BEGIN IMPACTING
THE WESTERN ZONES IN THE 1-2PM WINDOW. THIS WOULD PUT THE LINE
INTO THE SAVANNAH METRO AREA 3-5PM AND THEN THE CHARLESTON REGION
BETWEEN 6-8PM. THE POTENTIAL FOR SEVERE WEATHER APPEARS TO BE
INCREASING. UPSTREAM OFFICES HAVE BEEN ISSUING A MIXTURE OF
SEVERE/TORNADO WARNINGS THIS MORNING WITH A NUMBER OF WIND DAMAGE
REPORTS. BASED ON ITS LOCATION RELATIVE TO THE LINE AT 12Z...THE
TAE MORNING SOUNDING IS LIKELY THE BEST SAMPLING OF THE
APPROACHING NEAR STORM ENVIRONMENT. AS SUCH...WE EXPECT A STRONGLY
SHEARED ENVIRONMENT WITH A NICE VEERING OF THE LOW LEVEL PROFILE
AND CAPE VALUES INCREASING INTO THE 1500-2000 J/KG RANGE. IN
FACT...THE TAE SOUNDING HAS A DISTINCT ELEVATED MIXED LAYER THAT
ACTUALLY SHOWS UP WELL WHEN LOOKING AT HRRR SOUNDINGS LATER THIS
AFTERNOON. ONE OF THE MORE TROUBLING ASPECTS IS THE POTENTIAL FOR
A WINDOW OF CLEARING NOTED ON VISIBLE SATELLITE IMAGERY. AS THIS
CLEARING HAS MOVED ACROSS SOUTH GEORGIA TEMPERATURES HAVE RISEN
INTO THE UPPER 70S AND EVEN TO 80 WITHIN JUST AN HOUR. GIVEN LOW
LEVEL THICKNESS VALUES AS THEY ARE...EVEN A BRIEF PERIOD OF SUN
WILL LEAD TO A RAPID WARM UP AND INCREASE THE SURFACE
DESTABILIZATION POTENTIAL.
SO USING THE HRRR AND ITS SOUNDINGS AS THE BEST REPRESENTATION OF
THE AFTERNOON NEAR STORM ENVIRONMENT...IT APPEARS WE ARE LOOKING
AT CAPE VALUES AS HIGH AS 2500 J/KG...0-3 KM SHEAR OF 30-35
KT...AND SRH VALUES BETWEEN 150-250 THANKS TO THE SOUTHEAST
BACKED LOW LEVEL FLOW. SUCH AN ENVIRONMENT WILL LIKELY FAVOR A
CONVECTIVE MODE OF LINEAR SEGMENTS WITH EMBEDDED SUPERCELL
ELEMENTS AND EVEN THE POTENTIAL FOR A DISCRETE SUPERCELL OR TWO.
DAMAGING WIND GUSTS CONTINUES TO BE THE PRIMARY SEVERE WEATHER
THREAT...BUT THE SHEAR AND LOW LEVEL VEERING WILL ALSO PROVIDE A
TORNADO THREAT AS WELL. MUCH WILL BE DETERMINED BY HOW MUCH SUN
CAN BREAK THROUGH AND TEMPERATURES WARM. ONE OTHER POTENTIAL THING
TO WATCH IS THAT THE CURRENT SOUTHEAST WINDS COULD ADVECT IN A
SLIGHTLY MORE STABLE MARINE ENVIRONMENT. HOWEVER...GIVEN THAT WE
ARE OUT OF THE COOLEST SHELF WATER SEASON THIS IMPACT IS EXPECTED
TO BE LIMITED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
TONIGHT...THE SHORTWAVE WILL PUSH OFF THE COAST AND ELEVATED POPS
DURING THE EVENING HOURS SHOULD DECREASE BELOW 15 PERCENT AS
SOMEWHAT DRIER AIR AND TEMPORARY SUBSIDENCE DEVELOP OVERNIGHT INTO
EARLY MONDAY. ANOTHER IN A SERIES OF VERY MILD OVERNIGHTS WITH
TEMPS ONLY FALLING TO THE MID 60S ONCE AGAIN.
THE LONGWAVE TROUGH WILL PERSIST TO OUR WEST ON MONDAY WHILE A
SERIES OF POTENT SHORTWAVES LIFT NORTHEAST THROUGH THE LOCAL
FORECAST AREA. A 145 KT SOUTHERN STREAM JET STREAK IS PROGGED TO
SLIDE ALONG THE CENTRAL GULF COAST REGION DURING THE DAY...SPREADING
A REGION OF ENHANCED UPPER LEVEL DIVERGENCE INTO SC/GA IN THE AFTERNOON.
MODEL TIME SECTIONS SHOW CONSIDERABLE DRYING ABOVE 850 MB EARLY IN
THE PERIOD...WITH PWATS DROPPING BELOW 1.25" BY MONDAY AFTERNOON.
THE MAIN COLD FRONT WILL SLOWLY MOVE EAST DURING THE DAY...CROSSING
THE REGION AT SOME POINT MONDAY EVENING. GIVEN THE DRY AIR ALOFT...
CONSIDERABLE BREAKS IN THE CLOUDS AND COMPRESSIONAL HEATING AHEAD
OF THE FRONT SHOULD HELP PUSH TEMPS INTO THE MID/UPPER 80S.
THE BIG QUESTION ON MONDAY IS HOW MUCH CONVECTIVE COVERAGE DEVELOPS.
THE DEEP DRY LAYER ABOVE THE SURFACE MAY LIMIT THE INITIAL
CONVECTIVE DEVELOPMENT. HOWEVER...MODELS ARE HINTING AT AN UPSTREAM
CONVECTIVE CLUSTER MOVING INTO WESTERN AREAS LATER IN THE AFTERNOON.
THERMODYNAMICS AND KINEMATICS ARE QUITE IMPRESSIVE ON MONDAY. 40-50
KT OF 0-6 KM BULK SHEAR...CAPES OF 1500-2000 J/KG AND DOWNDRAFT
CAPES 1000 TO 1500 J/KG. A FAIRLY ROBUST SEA BREEZE IS EXPECTED TO
DEVELOP IN THE AFTERNOON GIVEN SUCH WARM TEMPS INLAND AND PREVAILING
SOUTHERLY FLOW. THIS MAY COME INTO PLAY LATE IN THE DAY IF UPSTREAM
CONVECTION MOVES IN FROM THE WEST.
GIVEN THE SOMEWHAT DRIER TREND IN THE LATEST MODELS...WE MINIMIZED
POPS MONDAY MORNING WITH VALUES INCREASING TO 30-40% IN THE
AFTERNOON...ESPECIALLY ACROSS INTERIOR SC/GA. AS THE ACTIVITY AHEAD
OF THE FRONT MOVES THROUGH OUR AREA IT SHOULD BE GRADUALLY
WEAKENING. THEN SOME ADDITIONAL ACTIVITY...LIKELY WEAKER...COULD
ACCOMPANY THE ACTUAL FRONT LATER IN THE EVENING OR OVERNIGHT. WE
PLAN TO MAINTAIN SEVERE WEATHER POTENTIAL IN THE HAZARDOUS WEATHER
OUTLOOK.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT WITH DRY WEATHER AND
SEASONABLE TEMPERATURES TUESDAY AND WEDNESDAY. HIGHS WILL CLIMB TO
NEAR 80 BOTH DAYS WITH OVERNIGHT LOWS IN THE MID 50S.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
A ZONAL PATTERN WILL EXIST MUCH OF THE PERIOD. A WEAK BACK DOOR COLD
FRONT DROPS THROUGH THE AREA THURSDAY NIGHT. THE FRONT WILL STALL TO
THE SOUTH BEFORE LIFTING BACK NORTH AS A WARM FRONT FRIDAY NIGHT AND
SATURDAY. A PRONOUNCED SHORTWAVE EMBEDDED IN THE QUASI-ZONAL FLOW
WILL MOVE THROUGH SATURDAY NIGHT ACCOMPANIED BY A COLD FRONT.
PRECIPITATION POSSIBLE STARTING FRIDAY NIGHT AND CONTINUING INTO
SATURDAY NIGHT. TEMPS WILL BE MODERATED BY INCREASING CLOUD COVER
AND WEAK COLD ADVECTION.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
DEEP MOISTURE ACROSS THE TAF CORRIDOR TODAY. LAYERED CLOUDS THIS
MORNING DIFFICULT TO PIN DOWN AS RECENTLY LOW STRATUS DECKS DEVELOPED
IN THE WARM FRONTAL ZONE DEVELOPING ACROSS THE REGION. MODELS
INDICATE THAT IFR/LIFR CIGS AND IFR VSBYS SHOULD BE CONFINED TO
THE MORNING HOURS WITH MVFR TO VFR CIGS DEVELOPING IN A BIT OF A
DRIER SLOT THIS AFTERNOON AHEAD OF CONVECTION THAT SHOULD SWEEP
THROUGH THE TERMINALS IN THE 19Z TO 00Z TIME FRAME. TSTMS ARE
POSSIBLE WITH HEAVY DOWNPOURS AND PERHAPS GUSTY AND SHIFTING
WINDS. MAINLY VFR TONIGHT BUT MVFR/IFR CIGS ARE POSSIBLE LATE.
EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS/TSTMS EXPECTED AT BOTH
TERMINALS MONDAY AFTERNOON AND EVENING WITH BRIEF MVFR CEILING/VSBY
RESTRICTIONS POSSIBLE. OTHERWISE VFR CONDITIONS EXPECTED.
&&
.MARINE...
A WARM FRONT WILL LIFT THROUGH THE WATERS TODAY...FOLLOWED BY
INTENSIFYING SOUTH/SOUTHWEST FLOW. LIGHT AND VARIABLE WINDS EARLY
THIS MORNING WILL BECOME SE PRIOR TO THE WARM FRONT WHICH WILL
SHIFT FLOW SW TO S TONIGHT. WHILE SPEEDS INCREASE TONIGHT AND SEAS
SLOWLY BUILD...THE AVERAGE SPEED COULD REACH ONLY 15 KT BY
DAYBREAK OVER NEAR SHORE WATERS WITH SEAS 3 TO 4 FT.
THE POTENTIAL EXISTS FOR THUNDERSTORMS WITH STRONG WINDS OVER THE
WATERS THIS AFTERNOON EVENING. VERY HEAVY DOWNPOURS REDUCING
LOCAL VSBYS BELOW 1 NM ARE ALSO POSSIBLE WITH THE STRONGEST
STORMS MOVING OFFSHORE LATE IN THE DAY AND EARLY THIS EVENING.
A PREVAILING SSW FLOW WILL EXIST MONDAY MORNING AS A COLD FRONT
APPROACHES FROM THE WEST. THE GRADIENT WILL STRENGTHEN DURING THE
AFTERNOON...ESPECIALLY ALONG THE COAST WHERE A STRONG SEA BREEZE
DEVELOPS DUE TO MID/UPPER 80S TEMPS OVER LAND. THE LATEST GFS AND
NAM MOS AT FOLLY BEACH SC SHOW SFC WINDS EXCEEDING 20 KT LATE MONDAY
AFTERNOON WHEN THE SEA BREEZE IS STRONGEST. THIS SEEMS FAIRLY
REASONABLE GIVEN THE PATTERN AND THE WARMER INLAND TEMPS EXPECTED. A
SMALL CRAFT ADVISORY MAY EVENTUALLY BE REQUIRED FOR CHARLESTON
HARBOR MONDAY AFTERNOON FOR WINDS/GUSTS IN THE 20-30 KT RANGE.
A BRIEF PERIOD OF SMALL CRAFT ADVISORY CONDITIONS MAY DEVELOP OVER
OFFSHORE WATERS MONDAY NIGHT AS THE COLD FRONT MOVES THROUGH AND
WINDS GUST TO 25 KT WITH SOME 6 FT SEAS ALSO POSSIBLE.
TUESDAY THROUGH FRIDAY LOOK FAIRLY QUIET OVER THE WATERS AS HIGH
PRESSURE PREVAILS.
&&
.TIDES/COASTAL FLOODING...
THERE IS A CHANCE THAT THE HIGH TIDE COULD REACH OR SLIGHTLY
EXCEED 7.0 FT MLLW ON CHARLESTON HARBOR THIS EVENING.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...BSH
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...
MARINE...JRL
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
952 AM CDT SUN APR 19 2015
.UPDATE...
952 AM CDT
I MADE SOME UPDATES TO THE FORECAST FOR TODAY TO RAISE
TEMPERATURES AND PUSH OFF THE TIMING OF THE RAIN CHANCES.
WATER VAPOR IMAGERY INDICATES OUR MID/UPPER LEVEL DISTURBANCE OF
INTEREST FOR LATER TODAY NOW LIFTING NORTHWARD ACROSS WESTERN
KENTUCKY. THIS FEATURE IS CURRENTLY SUPPORTING AN AREA OF
NORTHWARD MOVING SHOWERS ACROSS SOUTHERN PORTIONS OF ILLINOIS AND
INDIANA. THEREFORE...THIS AREA OF SHOWERS WILL GRADUALLY WORK
NORTHWARD ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA
DURING THE AFTERNOON. IT APPEARS THE THREAT FOR THUNDERSTORMS WILL
BE VERY LOW WITH THIS ACTIVITY...WITH TRENDS SUGGESTING NO
LIGHTNING STRIKES OVER THE PAST FEW HOURS...SO I HAVE REMOVED THE
MENTION OF SUCH THIS AFTERNOON. IN ADDITION...WITH THE SLOWER
ONSET OF PRECIP TODAY...IT APPEARS TEMPERATURES WILL BE ABLE TO
WARM TO NEAR 70 IN MOST AREAS AWAY FROM LAKE MICHIGAN...SO I
RAISED HIGH TEMPERATURES TODAY.
KJB
&&
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* EAST WINDS BETWEEN 7-12KT INCREASING TO 12-15KT WITH GUSTS UP TO
20KT THRU MIDDAY.
* WEST WINDS GUSTING TO 20 KT TOMORROW.
* RAIN OVERSPREADS TAF SITES LATER THIS AFTN THRU TONIGHT. MVFR
VSBY IS PSBL UNDER HEAVIER SHOWERS.
* LOW END MVFR CIGS DEVELOP...POSSIBLY IFR CONDS DEVELOP BY 3Z
THRU DAYBREAK MON.
JEE
//DISCUSSION...UPDATED 12Z...
EAST WINDS CONTINUE TO KEEP THE LOW LEVELS RELATIVELY DRY AND LACK
OF LOW CLOUDS...HOWEVER MOISTURE IS CREEPING NORTH ACROSS SOUTHERN
IL/IN. WINDS WILL OCCASIONALLY GUST TO 20KT THRU MIDDAY...THEN
EXPECT WITH THE ABUNDANCE OF MOISTURE AND RAIN THE GUSTS MAY
BECOME LESS FREQUENT WITH SUSTAINED WINDS INCREASING SLIGHTLY TO
ARND 12-15KT. AS A LOW PRESSURE LIFTS NORTHEAST TOWARDS THE REGION
TONIGHT...CIGS ARE EXPECTED TO LOWER TO MVFR AND LIKELY TO IFR
CONDS WITH BASES ARND 800FT AGL BY 3Z. A FEW GUIDANCE MEMBERS
SUGGEST CIGS MAY DIP FURTHER TO ARND 400FT AGL BY 6Z AS A BRIEF
LULL IN THE PRECIP IS POISED TO LIFT OVERHEAD. AT THIS TIME WILL
MENTION VCSH BY 6Z MON...WHICH MAY END UP AS DRIZZLE OR LGT RAIN.
CIGS WILL REMAIN IFR THRU DAYBREAK MON...UNTIL A TIGHT GRADIENT
RETURNS AND WINDS INCREASE FROM THE WEST/NORTHWEST. THIS SHUD HELP
TO LIFT CIGS BACK TO MVFR AND EVENTUALLY VFR CONDS BY LATER MON.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-HIGH CONFIDENCE IN RAIN TIMING AND COVERAGE.
* MEDIUM CONFIDENCE IN WIND SPEED AND DIRECTION AFTER 18Z.
* HIGH CONFIDENCE IN CIGS BCMG AT LEAST MVFR AND PSBLY
IFR...MEDIUM CONFIDENCE IN TIMING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
856 AM CDT SUN APR 19 2015
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* EAST WINDS BETWEEN 7-12KT INCREASING TO 12-15KT WITH GUSTS UP TO
20KT THRU MIDDAY.
* WEST WINDS GUSTING TO 20 KT TOMORROW.
* RAIN OVERSPREADS TAF SITES LATER THIS AFTN THRU TONIGHT. MVFR
VSBY IS PSBL UNDER HEAVIER SHOWERS.
* LOW END MVFR CIGS DEVELOP...POSSIBLY IFR CONDS DEVELOP BY 3Z
THRU DAYBREAK MON.
JEE
//DISCUSSION...UPDATED 12Z...
EAST WINDS CONTINUE TO KEEP THE LOW LEVELS RELATIVELY DRY AND LACK
OF LOW CLOUDS...HOWEVER MOISTURE IS CREEPING NORTH ACROSS SOUTHERN
IL/IN. WINDS WILL OCCASIONALLY GUST TO 20KT THRU MIDDAY...THEN
EXPECT WITH THE ABUNDANCE OF MOISTURE AND RAIN THE GUSTS MAY
BECOME LESS FREQUENT WITH SUSTAINED WINDS INCREASING SLIGHTLY TO
ARND 12-15KT. AS A LOW PRESSURE LIFTS NORTHEAST TOWARDS THE REGION
TONIGHT...CIGS ARE EXPECTED TO LOWER TO MVFR AND LIKELY TO IFR
CONDS WITH BASES ARND 800FT AGL BY 3Z. A FEW GUIDANCE MEMBERS
SUGGEST CIGS MAY DIP FURTHER TO ARND 400FT AGL BY 6Z AS A BRIEF
LULL IN THE PRECIP IS POISED TO LIFT OVERHEAD. AT THIS TIME WILL
MENTION VCSH BY 6Z MON...WHICH MAY END UP AS DRIZZLE OR LGT RAIN.
CIGS WILL REMAIN IFR THRU DAYBREAK MON...UNTIL A TIGHT GRADIENT
RETURNS AND WINDS INCREASE FROM THE WEST/NORTHWEST. THIS SHUD HELP
TO LIFT CIGS BACK TO MVFR AND EVENTUALLY VFR CONDS BY LATER MON.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-HIGH CONFIDENCE IN RAIN TIMING AND COVERAGE.
* MEDIUM CONFIDENCE IN WIND SPEED AND DIRECTION AFTER 18Z.
* HIGH CONFIDENCE IN CIGS BCMG AT LEAST MVFR AND PSBLY
IFR...MEDIUM CONFIDENCE IN TIMING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
647 AM CDT SUN APR 19 2015
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* EAST WINDS BETWEEN 7-12KT INCREASING TO 12-15KT WITH GUSTS UP TO
20KT THRU MIDDAY.
* WINDS TURN NORTH LATE TONIGHT...THEN NORTHWEST EARLY MON.
* RAIN OVERSPREADS TAF SITES LATER THIS AFTN THRU TONIGHT.
* LOW END MVFR CIGS DEVELOP...POSSIBLY IFR CONDS DEVELOP BY 3Z
THRU DAYBREAK MON.
BEACHLER
//DISCUSSION...UPDATED 12Z...
EAST WINDS CONTINUE TO KEEP THE LOW LEVELS RELATIVELY DRY AND LACK
OF LOW CLOUDS...HOWEVER MOISTURE IS CREEPING NORTH ACROSS SOUTHERN
IL/IN. WINDS WILL OCCASIONALLY GUST TO 20KT THRU MIDDAY...THEN
EXPECT WITH THE ABUNDANCE OF MOISTURE AND RAIN THE GUSTS MAY
BECOME LESS FREQUENT WITH SUSTAINED WINDS INCREASING SLIGHTLY TO
ARND 12-15KT. AS A LOW PRESSURE LIFTS NORTHEAST TOWARDS THE REGION
TONIGHT...CIGS ARE EXPECTED TO LOWER TO MVFR AND LIKELY TO IFR
CONDS WITH BASES ARND 800FT AGL BY 3Z. A FEW GUIDANCE MEMBERS
SUGGEST CIGS MAY DIP FURTHER TO ARND 400FT AGL BY 6Z AS A BRIEF
LULL IN THE PRECIP IS POISED TO LIFT OVERHEAD. AT THIS TIME WILL
MENTION VCSH BY 6Z MON...WHICH MAY END UP AS DRIZZLE OR LGT RAIN.
CIGS WILL REMAIN IFR THRU DAYBREAK MON...UNTIL A TIGHT GRADIENT
RETURNS AND WINDS INCREASE FROM THE WEST/NORTHWEST. THIS SHUD HELP
TO LIFT CIGS BACK TO MVFR AND EVENTUALLY VFR CONDS BY LATER MON.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN ALL ELEMENTS THROUGH 18Z...MEDIUM CONFIDENCE
IN WIND DIR/SPEED AFT 18Z.
* MEDIUM CONFIDENCE IN PRECIP TIMING/COVERAGE.
* HIGH CONFIDENCE IN CIGS DIMINISHING TO AT LEAST MVFR CONDS AFT
21Z...AND MEDIUM CONFIDENCE IN CIGS BECOMING IFR AFT 3Z MON.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
642 AM CDT SUN APR 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT SUN APR 19 2015
LATEST WATER VAPOR IMAGERY CONTINUES TO SHOW CLOSED UPPER LOW OVER
EASTERN COLORADO, WITH LEAD SHORT-WAVE ROTATING AROUND THIS FEATURE
ACROSS ARKANSAS/LOUISIANA. AS THIS WAVE LIFTS NORTHWARD, PRECIP
WILL EVENTUALLY SPREAD INTO CENTRAL ILLINOIS TODAY. 07Z/2AM RADAR
MOSAIC SHOWS DRY CONDITIONS ACROSS THE ENTIRE KILX CWA: HOWEVER,
SHOWERS ARE BEGINNING TO DEVELOP AND BECOME MORE WIDESPREAD FURTHER
SOUTH ACROSS WESTERN KENTUCKY AND FAR SOUTHERN ILLINOIS. BASED ON
RADAR TIMING TOOLS AND LATEST HRRR FORECAST, THINK SCATTERED SHOWERS
WILL ARRIVE SOUTH OF I-70 OVER THE NEXT COUPLE OF HOURS, THEN WILL
SPREAD NORTHWARD TOWARD THE I-74 CORRIDOR BY MIDDAY. HAVE ADJUSTED
POPS TO ACCOUNT FOR THE SLOWER ARRIVAL OF PRECIP DURING THE MORNING,
THEN HAVE GONE WITH CATEGORICAL POPS ACROSS THE BOARD THIS
AFTERNOON. ASIDE FROM SOME SBCAPES OF AROUND 1000J/KG ACROSS THE
FAR SE CWA, FORECAST SOUNDINGS REMAIN FAIRLY STABLE TODAY. AS A
RESULT, AM EXPECTING MAINLY SHOWERS WITH JUST A FEW EMBEDDED
THUNDERSTORMS. DUE TO CLOUD COVER AND PRECIP, HIGH TEMPERATURES
WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS, WITH READINGS
MAINLY IN THE 60S. WARMEST TEMPS OF AROUND 70 WILL BE FOCUSED
ALONG/WEST OF THE ILLINOIS RIVER WHERE PRECIP WILL BE SLOWEST TO
ARRIVE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 328 AM CDT SUN APR 19 2015
LEAD SHORT-WAVE WILL LIFT INTO NORTHERN ILLINOIS/INDIANA BY EARLY
EVENING, LIKELY LEADING TO A TEMPORARY LULL IN THE SHOWERS.
MEANWHILE, THE MAIN UPPER LOW WILL GET A SOLID PUSH EASTWARD AND
WILL ARRIVE ACROSS ILLINOIS LATER TONIGHT INTO MONDAY MORNING.
SHOWERS AND PERHAPS A THUNDERSTORM WILL ACCOMPANY THIS FEATURE, SO
WILL CONTINUE LIKELY POPS TONIGHT THROUGH MONDAY MORNING. ONCE THE
500MB VORT MAX AND THE ASSOCIATED SURFACE COLD FRONT PASS TO THE
EAST, RAIN CHANCES WILL COME TO AN END BY MONDAY AFTERNOON. THANKS
TO A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT, STRONG W/NW
WINDS GUSTING TO BETWEEN 25 AND 30 MPH WILL DEVELOP ON MONDAY. THE
WINDS WILL SUBSIDE FOR A TIME MONDAY NIGHT, BUT WILL ONCE AGAIN
INCREASE MARKEDLY DURING THE DAY TUESDAY. HIGH TEMPERATURES BOTH
DAYS WILL REMAIN IN THE LOWER 60S, WHILE OVERNIGHT LOWS DIP INTO THE
UPPER 30S AND LOWER 40S.
00Z APR 19 MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING
THE EXTENDED FORECAST, WITH CONSENSUS FEATURING A CHILLY AND LARGELY
DRY WEEK AHEAD. BOTH THE GFS AND ECMWF INDICATE A WEAK COLD FRONT
WILL PASS THROUGH CENTRAL ILLINOIS TUESDAY NIGHT INTO WEDNESDAY:
HOWEVER, THEY DISAGREE ON HOW MUCH PRECIP IT WILL GENERATE. THE GFS
IS SLIGHTLY WETTER AND FASTER WITH FROPA, WHILE THE ECMWF IS DRIER
AND ABOUT 6 HOURS SLOWER WITH THE FRONT. DUE TO THE STRONG
NORTHWESTERLY UPPER FLOW PATTERN IN PLACE ACROSS THE MIDWEST, THINK
THE FASTER GFS IS THE WAY TO GO WITH TIMING, BUT THINK THE DRIER
ECMWF IS BETTER WITH QPF AS DEEP MOISTURE WILL BE LACKING WITH THIS
FEATURE. AS A RESULT, HAVE OPTED TO CARRY LOW CHANCE POPS
EVERYWHERE TUESDAY NIGHT, THEN ONLY ACROSS THE SE CWA ON WEDNESDAY.
ONCE THE FRONT PASSES, A COOL/CANADIAN AIRMASS WILL SETTLE INTO THE
REGION FOR THE MIDDLE AND END OF THE WEEK. HIGH TEMPERATURES WILL
STRUGGLE TO REACH THE 60 DEGREE MARK ON BOTH WEDNESDAY AND THURSDAY,
WHILE LOWS DROP INTO THE 30S. COLDEST MORNING MAY END UP BEING
FRIDAY MORNING, WHEN RIDGE OF HIGH PRESSURE IS OVERHEAD AND WINDS
WILL BE LIGHTEST. WILL NEED TO KEEP AN EYE ON TEMPS, AS FROST
ADVISORIES WILL BE POSSIBLE ACROSS PARTS OF CENTRAL/SOUTHEAST
ILLINOIS LATER THIS WEEK. AFTER THAT, ANOTHER SYSTEM WILL APPROACH
FROM THE SOUTHWEST BY THE END OF THE WEEK: HOWEVER, ITS INFLUENCE
LIKELY WILL NOT BE FELT UNTIL FRIDAY NIGHT/SATURDAY AT THE EARLIEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 542 AM CDT SUN APR 19 2015
MID AND HIGH CLOUDS WILL CONTINUE OVER THE AREA THIS MORNING,
EFFECTING ALL TAF SITES UNTIL THE PCPN MOVES INTO THE SITES. WILL
START ALL SITES WITH VCSH AS THE PCPN MOVES NORTHWARD AND
INITIALLY SATURATES THE LOWER LEVELS, DURING THE MORNING HOURS.
THEN BETWEEN 10AM AND NOON, PCPN WILL BECOME MORE DOMINATE AND
STEADY. TIMING OF ONSET OF PCPN WAS TAKEN FROM A BLEND OF THE
BUFKIT DATA, NAM12, HRRR, AND RADAR TRENDS. MVFR CIGS AND VIS
WILL ARRIVE WITH THE RAIN AND CONTINUE THROUGH REST OF TAF VALID
PERIOD. PCPN COULD LET UP SOME LATE THIS EVENING, SO HAVE ADDED
ANOTHER LINE FOR VCSH AFTER THE BULK OF THE RAIN MOVES THROUGH,
AND BEFORE THE NEXT BATCH ARRIVES LATE TONIGHT/EARLY TOMORROW
MORNING. WINDS WILL BE EASTERLY TO START, BUT THEN BECOME
SOUTHEASTERLY AS THE SYSTEM GET CLOSER TO THE SITES. WITH THE
SURFACE LOW PRESSURE AREA MOVING RIGHT OVER THE TAFS, WINDS WILL
BE VARIABLE, ENDING AT WEST TO SOUTHWEST LATER TONIGHT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
733 AM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 730 AM CDT SUN APR 19 2015
SCATTERED SHOWERS CONTINUE TO DEVELOP AND MOVE GENERALLY IN A NORTHWARD
DIRECTION...AND WERE MAINLY WEST OF A MACOMB IL TO MANCHESTER IA LINE.
THESE SHOWERS WERE OCCURRING IN THE AXIS OF THE BETTER 850 MB MOISTURE
TRANSPORT AND PRECIPITABLE WATERS OVER AN INCH.
ELSEWHERE...LOW PRESSURE WAS ORGANIZING IN THE LOWER MS VALLEY AND
A BROAD AREA OF PRESSURE FALLS WAS NOTED TO THE NORTH INDICATING LARGE
SCALE ASCENT/WARM AIR ADVECTION WAS INCREASING. ALSO PRESSURE FALLS
WERE OCCURRING IN THE UPPER MS VALLEY IN ASSOCIATION WITH THE DIGGING
NORTHERN STREAM TROUGH. REGIONAL DOPPLER RADARS WERE SHOWING THE LEADING
EDGE OF A RATHER LARGE AREA OF RAIN/ISOLATED THUNDERSTORMS FROM THE
MO OZARKS AND SOUTHERN IL...MOVING NORTHWARD.
THE HRRR MESO MODEL HAS CAPTURED THIS RAIN AREA WITH THE LEADING
EDGE REACHING MACOMB BY NOON...THE QUAD CITIES BY EARLY AFTERNOON
AND DUBUQUE/FREEPORT BY LATE AFTERNOON. THEREFORE...WIDESPREAD
RAIN APPEARS LIKELY THIS AFTERNOON AND CONTINUING TONIGHT...WHICH
THE CURRENT GRIDS DEPICT.
&&
.SYNOPSIS...
ISSUED AT 345 AM CDT SUN APR 19 2015
MODELS CONTINUE TO STRUGGLE WITH THE EASTERLY FEED OF DRY AIR INTO
OUR NORTHEAST CWA AND AT SOME LOCATIONS DEWPOINTS WERE 10 DEGREES
LOWER THAN ANY GUIDANCE. IN OUR WESTERN CWA GUIDANCE WAS CLOSE TO
REALITY AS WINDS WERE MORE SOUTHEAST. SPC MESO ANALYSIS SHOWED
DECENT 850 MB MOISTURE TRANSPORT ALONG WITH PRECIPITABLE WATERS
OVER AN INCH IN OUR WESTERN CWA. AND SURE ENOUGH DOPPLER RADAR HAS
SHOWN POCKETS OF SHOWERS AND ISOLATED THUNDERSTORMS ALL NIGHT.
RAINFALL ESTIMATES INDICATE 1/4 TO 3/4 OF AN INCH HAS FALLEN IN
SOME SPOTS IN OUR WEST SINCE LAST EVENING.
3 AM TEMPERATURES RANGED FROM 50 AT FREEPORT TO 61 AT MACOMB.
ELSEWHERE...CANADIAN HIGH PRESSURE WAS CENTERED NORTHEAST OF LAKE
SUPERIOR AND SOME SITES IN NW WI WERE REPORTING DEWPOINTS IN THE TEENS.
UPPER LEVEL TROUGH WAS DIGGING INTO THE NORTHERN PLAINS WHILE
ANOTHER TROUGH WAS PUSHING INTO THE CENTRAL/SOUTHERN PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT SUN APR 19 2015
FORECAST FOCUS ON INCREASING RAIN AND TEMPERATURES.
TODAY...UPPER LEVEL TROUGH APPROACHES FROM THE WEST AND THIS WILL PROVIDE
LARGE SCALE ASCENT ALONG WITH BETTER MOISTURE TRANSPORT AS THE DAY PROGRESSES.
THE MORE WIDESPREAD RAIN APPEARS TO DEVELOP THIS AFTERNOON WITH THE
ARRIVAL OF STRONGER FORCING...AS A SHORT WAVE PUSHES ACROSS IA AHEAD
OF THE MAIN TROUGH. MEANWHILE...PHASING BEGINS TO OCCUR AND MODELS LIFT
A DEEPENING CYCLONE OUT OF THE LOWER MS VALLEY INTO FAR WESTERN INDIANA
BY 00Z. INTERESTING THAT THE NAM/ECMWF KEEP NW IL DRY MUCH OF THE DAY
AND THEY MAY BE ON TO SOMETHING WITH SUCH A DRY EASTERLY FEED INTO THAT
AREA. I WILL MENTION ISOLATED THUNDERSTORMS THIS AFTERNOON AS DEEP LAYER
SHEAR IS WEAK AND MUCAPE IS 500 J/KG OR LESS. WITH MORE CLOUDINESS TODAY
MAXIMUM TEMPERATURES SHOULD BE COOLER THAN THAN THE PAST COUPLE OF DAYS.
I AM EXPECTING HIGHS IN THE UPPER 60S TO LOWER 70S AT MOST LOCATIONS.
TONIGHT...PHASING IS NEARLY COMPLETE AND A LONG WAVE TROUGH PUSHES
ACROSS THE MIDWEST WITH DECENT FORCING AND GOOD MOISTURE IN PLACE.
IN THE MEANTIME...THE SLOWLY DEEPENING CYCLONE LIFTS INTO NORTHERN
LOWER MI BY 12Z. MODELS INDICATE WIDESPREAD RAIN OVER THE CWA MUCH
OF THE NIGHT. THIS LOOKS TO BE MORE OF A STRATIFORM/DEFORMATION TYPE
RAIN RATHER THAN ALL OUT CONVECTIVE/MCS TYPE SO WILL NOT MENTION THUNDER
AS INSTABILITY IS VERY LIMITED...AND THE ENTIRE COLUMN IS VERY SATURATED.
A COLD FRONT WILL PUSH ACROSS THE CWA DURING THE NIGHT USHERING MUCH
COOLER TEMPERATURES INTO THE AREA BY MORNING. MINIMUM TEMPERATURES
WILL RANGE FROM THE LOWER 40S AT INDEPENDENCE TO THE UPPER 40S AT
PRINCETON AND MACOMB IN ILLINOIS.
RAINFALL AMOUNTS TODAY THROUGH TONIGHT SHOULD BE 0.3 TO 0.7 INCHES OVER
MUCH OF THE CWA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 345 AM CDT SUN APR 19 2015
COOLER AND MAINLY DRY FOR MUCH OF UPCOMING WEEK WITH FROST/FREEZE
POTENTIAL LATER IN THE WEEK.
MUCH OF THE UPCOMING WEEK AHEAD WILL FEATURE A LARGE AND SLOW
MOVING UPPER LOW FROM THE GREAT LAKES TO EASTERN CANADA DUE TO
HIGHLY AMPLIFIED RIDGING OVER THE EASTERN ATLANTIC AND GREENLAND.
OUR CWA WILL BE GOVERNED BY NORTHWEST FLOW ON BACKSIDE OF THE
LARGE UPPER LOW WHICH WILL USHER IN REINFORCING BOUTS OF CANADIAN
AIR RESULTING IN COOLER HIGHS IN THE 50S AND 60S... WITH LOWS
MAINLY IN THE 30S. THE COOLER AIR WILL ALSO BE ACCOMPANIED BY
WINDY CONDITIONS MONDAY AND TUESDAY WITH THE POTENTIAL TO BE
NEAR WIND ADVISORY CRITERIA GIVEN JUXTAPOSITION OF TIGHT PRESSURE
GRADIENT... COLD ADVECTION AND DEEP MIXING. AFTER SOME LINGERING
SHOWERS POSSIBLE EARLY MONDAY AM... WILL HAVE THE POTENTIAL
FOR AFTERNOON POPCORN SHOWERS ACROSS MAINLY THE NORTHERN CWA BOTH
MONDAY AND TUESDAY WITH STEEP MID LEVEL LAPSE RATES... COLD
AIR ALOFT... AND SKINNY CAPE NOTED ON FORECAST SOUNDINGS. WILL
NEED TO WATCH FOR ENHANCED WIND GUSTS WITH ANY SHOWERS VIA
EVAPORATIVE COOLING OF PCPN IN LARGE... DRY SUB-CLOUD LAYER WITH
CLASSIC INVERTED V SOUNDINGS.
CANADIAN SURFACE RIDGE AXIS BUILDING IN THURSDAY INTO FRIDAY WILL
BRING POTENTIAL FOR FROST AND POSSIBLY FREEZING TEMPS ONE OR BOTH
MORNINGS. MIN TEMPS MAY NEED LOWERING BY 3-5 DEGS SOME LOCATIONS
ESPECIALLY THURSDAY AM BASED ON 850 MB TEMPS -4C TO -7C WITH MORE
WIDESPREAD 20S POSSIBLE WITH ANY DURATION OF CLEAR SKIES AND LIGHT
WINDS.
RAIN CHANCES LOOK TO RETURN BY EITHER LATE IN THE WEEK AND/OR NEXT
WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 730 AM CDT SUN APR 19 2015
VFR CONDS BECOMING MVFR/LCL IFR CONDS. SCATTERED SHOWERS IN EASTERN
IA THIS MORNING WILL EXPAND IN COVERAGE AND THE RAIN WILL BE WIDESPREAD
THIS AFTERNOON AND TONIGHT. ISOLATED THUNDERSTORMS ARE ALSO POSSIBLE...MAINLY
THIS AFTERNOON. A COLD FRONT WILL ALSO ARRIVE TONIGHT. EAST TO SOUTHEAST
WINDS LESS THAN 10 KNOTS TODAY THEN BECOMING NORTHWEST 15 TO 25 KNOTS
BEHIND THE COLD FRONT TONIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...HAASE
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...MCCLURE
AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS DULUTH MN
949 AM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 945 AM CDT SUN APR 19 2015
RAIN WILL CONTINUE TO AFFECT THE FORECAST AREA THROUGH THE DAY.
HOWEVER...THERE WILL BE AN HOUR OR TWO WHEN NO RAIN IS OCCURRING
AND TRIED TO ACCOUNT FOR THIS IN THE FORECAST. KEPT THE MAX TEMPS
THE SAME FOR NOW...BUT WILL LOOK INTO LOWERING LATER TODAY. REST
OF THE FORECAST IN THE BALLPARK.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
THE FOCUS REMAINS ON THE RAIN TODAY AND TONIGHT. REFINED THE PCPN
CHANCES BY USING A BLEND OF THE RAP13 AND HRRR MODEL RUNS THROUGH
THIS MORNING SINCE THE TWO MODELS SEEM TO BE DOING PRETTY WELL
CAPTURING THE LOCATION OF THE CURRENT RAIN. DID NOT MAKE ANY
DRAMATIC CHANGES TO RAINFALL. OVERALL...MUCH OF THE FORECAST AREA
CAN EXPECT ABOUT 0.30 TO 0.75 INCHES OF RAINFALL THROUGH TONIGHT.
AT 330 AM...AN AREA OF LOW PRESSURE WAS OVER THE BORDER BETWEEN
SOUTH DAKOTA AND SW MINNESOTA. A FRONTAL BOUNDARY EXTENDED
NORTHWARD TO ANOTHER AREA OF LOW PRESSURE IN SOUTHERN MANITOBA.
THERE WAS AN UPPER LEVEL TROUGH OVER THE NORTHERN HIGH PLAINS AND
SASKATCHEWAN/MANITOBA DIGGING AND DEEPENING TOWARDS THE NORTHERN
PLAINS AND ONTARIO. A LARGE AREA OF RAIN WAS LIFTING TO NNE
THROUGH THE SOUTHERN TWO THIRDS OF THE FORECAST AREA. THIS RAIN
WAS ASSOCIATED WITH A BAND OF MID LEVEL FRONTOGENESIS AHEAD OF THE
LOW NEAR THE SD/MN BORDER. THERE WAS ADDITIONAL RAIN IN EASTERN
SOUTH DAKOTA AND NW MINNESOTA MOVING TO THE EAST IN THE WAKE OF
THE TROUGH BOUNDARY AND AHEAD OF THE UPPER LEVEL TO THE WEST. THE
NORTHLAND HAD CLOUDY SKIES WITH TEMPERATURES IN THE UPPER 30S TO
MIDDLE 40S. THE NORTHLAND HAD LIGHT EASTERLY TO SOUTHEASTERLY
WINDS.
THIS MORNING...THE SURFACE LOW NEAR THE SD/MN BORDER WILL LIFT NE
TO THE AITKIN AREA BY THIS AFTERNOON. THE SURFACE LOW IN SOUTHERN
MANITOBA WILL DIG TO THE SE. THE RAIN OVER THE FORECAST AREA EARLY
THIS MORNING WILL CONTINUE LIFTING TO THE NORTH WITH THE BAND OF
MID LEVEL FRONTOGENESIS. PARTS OF THE NORTHERN FORECAST COULD PICK
UP TO AROUND A HALF INCH OF RAIN THROUGH THIS MORNING. THE COLD
FRONT IN NORTH DAKOTA WILL BEGIN TO MOVE INTO THE WESTERN FORECAST
AREA LATE THIS MORNING.
THIS AFTERNOON AND EVENING...THE TWO LOWS WILL GRADUALLY MERGE
INTO ONE LOW OVER NW ONTARIO. CLOUDY AND COOL WEATHER IS EXPECTED
WITH HIGHS RANGING FROM THE UPPER 40S OVER THE NORTH TO THE 50S
OVER THE SOUTH. MOST OF THE AFTERNOON AND EVENING RAIN WILL BE
OVER THE EASTERN FORECAST AREA AHEAD OF THE EASTWARD ADVANCING
COLD FRONT. A DRY SLOT WILL MOVE INTO THE WESTERN FORECAST
AREA...AND THERE COULD BE PARTIAL CLEARING IN THE SW FORECAST
AREA. ALSO...A PROMINENT BAND OF LOW/MID LEVEL FRONTOGENESIS WILL
SET UP OVER NW WISCONSIN THIS EVENING WHICH DEVELOP AND INTENSIFY
A BAND OF RAIN OVER THAT AREA. THE UPPER LEVEL TROUGH OVER THE
NORTHERN PLAINS AND SOUTH CENTRAL CANADA WILL DEEPEN AND DEVELOP
INTO A WELL DEFINED UPPER LEVEL OVER SOUTHERN MANITOBA THIS
AFTERNOON AND CONTINUE DEEPENING AS IT APPROACHES NORTHERN
MANITOBA.
LATER TONIGHT AND EARLY MONDAY...THE COLD FRONT WILL FINISH
MOVING THROUGH THE FORECAST AREA. THE UPPER LEVEL LOW WILL
CONTINUE DEEPENING OVER NW ONTARIO. THE LOW/MID LEVEL
FRONTOGENETICAL BAND IN NW WISCONSIN SHOULD EXIT TO THE EAST BY
AROUND DAWN. TEMPERATURES WILL DROP INTO THE MIDDLE AND LOWER 30S
TONIGHT. THE SYNOPTIC LIFT FROM THE UPPER LEVEL LOW WILL LIKELY
RESULT IN LIGHT RAIN AND SNOW MOVING INTO THE NW FORECAST AREA.
LITTLE OF ANY SNOW ACCUMULATION IS EXPECTED SINCE MUCH OF IT
SHOULD MELT...EITHER ON IMPACT OR LATER IN THE MORNING.
MONDAY...IT WILL BE MUCH COOLER DAY WITH BLUSTERY NW WINDS.
SUSTAINED WINDS OF 10 TO 20 MPH WILL DEVELOP BY THE
AFTERNOON...AND THERE COULD BE GUSTS UP TO 30 MPH. THE 850 HPA
TEMPERATURES WILL BE ABOUT -5 TO -6 DEGREES CELSIUS. HEAVY CLOUD
COVER AND THE COOL NW FLOW WILL PREVENT HIGHS FROM GETTING MUCH
HIGHER THAN THE LOW TO MIDDLE 40S. THERE WILL BE INCREASING
CHANCES OF COLD RAIN SHOWERS AS THE UPPER LOW DEEPENS AND MOVES TO
JUST NORTH OF KOOCHICHING COUNTY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
A DEEP AREA OF LOW PRESSURE WILL SETTLE SOUTHWARD INTO THE LAKE
SUPERIOR REGION MONDAY NIGHT AND TUESDAY. THE CLOSED H5 LOW WILL
REACH WESTERN LAKE SUPERIOR BY TUESDAY AFTERNOON. NUMEROUS
SHOWERS WILL ROTATE SOUTHWARD AROUND THE UPPER LOW...GENERALLY IN
THE FORM OF SNOW SHOWERS AT NIGHT AND RAIN OR SNOW SHOWERS DURING
THE DAY THROUGH THE MIDDLE OF THE WEEK. DEFINITELY COULD BE SOME
SLUSHY ACCUMULATION AT TIMES...ESPECIALLY IN THE NORTH. WOULD NOT
BE SURPRISED TO SEE A COUPLE EPISODES OF UP TO A COUPLE INCHES...
FOLLOWED BY SOME PARTIAL TO FULL MELTING DURING THE DAY. THIS
MASSIVE UPPER LEVEL TROUGH WILL EVENTUALLY LOSE ITS GRIP ON THE
AREA FROM THE MIDDLE TO THE END OF THE WORK WEEK. THE GEM AND TO
SOME EXTENT THE ECMWF ARE THE MOST AGGRESSIVE IN PUSHING THE
UPPER TROUGH EASTWARD THROUGH THE END OF THE WEEK...WITH THE GEM
BRINGING UPPER LEVEL RIDGING ALREADY INTO THE CWA BY 12Z FRIDAY.
THE GFS IS MUCH SLOWER AND DEEPER WITH THE UPPER LEVEL LOW.
STRONGLY FAVORING THE GEM/ECMWF SOLUTION...ESPECIALLY LATE IN THE
WEEK AND INTO THE WEEKEND. HIGH TEMPERATURES WILL REMAIN ON THE
COOL SIDE DURING THE WEEK...REACHING BACK INTO THE LOW TO MID 50S
ON THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 656 AM CDT SUN APR 19 2015
A LARGE AREA OF LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST INTO
THE NORTHLAND TODAY AND TONIGHT. ABUNDANT MOISTURE THROUGH THE
PLAINS WILL CONTINUE TO BRING AREAS OF LIGHT RAIN TODAY INTO
TONIGHT. CLOUD HEIGHTS ARE EXPECTED TO GRADUALLY DECREASE TO MVFR
OR EVEN IFR DURING THE MORNING...AND REMAIN THAT WAY THROUGH THE
AFTERNOON. SOME IMPROVEMENT IN CLOUD HEIGHTS WILL BE POSSIBLE FROM
THE WEST...AS SOMEWHAT DRIER AIR PUSHES EASTWARD BEHIND A COLD
FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 34 44 29 / 90 30 30 60
INL 49 32 40 28 / 100 40 60 60
BRD 56 35 43 31 / 80 20 40 40
HYR 58 37 46 30 / 90 80 30 60
ASX 58 37 47 32 / 80 80 20 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR
LSZ142>147.
&&
$$
UPDATE...GSF
SHORT TERM...GROCHOCINSKI
LONG TERM...DAP
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS DULUTH MN
701 AM CDT SUN APR 19 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
THE FOCUS REMAINS ON THE RAIN TODAY AND TONIGHT. REFINED THE PCPN
CHANCES BY USING A BLEND OF THE RAP13 AND HRRR MODEL RUNS THROUGH
THIS MORNING SINCE THE TWO MODELS SEEM TO BE DOING PRETTY WELL
CAPTURING THE LOCATION OF THE CURRENT RAIN. DID NOT MAKE ANY
DRAMATIC CHANGES TO RAINFALL. OVERALL...MUCH OF THE FORECAST AREA
CAN EXPECT ABOUT 0.30 TO 0.75 INCHES OF RAINFALL THROUGH TONIGHT.
AT 330 AM...AN AREA OF LOW PRESSURE WAS OVER THE BORDER BETWEEN
SOUTH DAKOTA AND SW MINNESOTA. A FRONTAL BOUNDARY EXTENDED
NORTHWARD TO ANOTHER AREA OF LOW PRESSURE IN SOUTHERN MANITOBA.
THERE WAS AN UPPER LEVEL TROUGH OVER THE NORTHERN HIGH PLAINS AND
SASKATCHEWAN/MANITOBA DIGGING AND DEEPENING TOWARDS THE NORTHERN
PLAINS AND ONTARIO. A LARGE AREA OF RAIN WAS LIFTING TO NNE
THROUGH THE SOUTHERN TWO THIRDS OF THE FORECAST AREA. THIS RAIN
WAS ASSOCIATED WITH A BAND OF MID LEVEL FRONTOGENESIS AHEAD OF THE
LOW NEAR THE SD/MN BORDER. THERE WAS ADDITIONAL RAIN IN EASTERN
SOUTH DAKOTA AND NW MINNESOTA MOVING TO THE EAST IN THE WAKE OF
THE TROUGH BOUNDARY AND AHEAD OF THE UPPER LEVEL TO THE WEST. THE
NORTHLAND HAD CLOUDY SKIES WITH TEMPERATURES IN THE UPPER 30S TO
MIDDLE 40S. THE NORTHLAND HAD LIGHT EASTERLY TO SOUTHEASTERLY
WINDS.
THIS MORNING...THE SURFACE LOW NEAR THE SD/MN BORDER WILL LIFT NE
TO THE AITKIN AREA BY THIS AFTERNOON. THE SURFACE LOW IN SOUTHERN
MANITOBA WILL DIG TO THE SE. THE RAIN OVER THE FORECAST AREA EARLY
THIS MORNING WILL CONTINUE LIFTING TO THE NORTH WITH THE BAND OF
MID LEVEL FRONTOGENESIS. PARTS OF THE NORTHERN FORECAST COULD PICK
UP TO AROUND A HALF INCH OF RAIN THROUGH THIS MORNING. THE COLD
FRONT IN NORTH DAKOTA WILL BEGIN TO MOVE INTO THE WESTERN FORECAST
AREA LATE THIS MORNING.
THIS AFTERNOON AND EVENING...THE TWO LOWS WILL GRADUALLY MERGE
INTO ONE LOW OVER NW ONTARIO. CLOUDY AND COOL WEATHER IS EXPECTED
WITH HIGHS RANGING FROM THE UPPER 40S OVER THE NORTH TO THE 50S
OVER THE SOUTH. MOST OF THE AFTERNOON AND EVENING RAIN WILL BE
OVER THE EASTERN FORECAST AREA AHEAD OF THE EASTWARD ADVANCING
COLD FRONT. A DRY SLOT WILL MOVE INTO THE WESTERN FORECAST
AREA...AND THERE COULD BE PARTIAL CLEARING IN THE SW FORECAST
AREA. ALSO...A PROMINENT BAND OF LOW/MID LEVEL FRONTOGENESIS WILL
SET UP OVER NW WISCONSIN THIS EVENING WHICH DEVELOP AND INTENSIFY
A BAND OF RAIN OVER THAT AREA. THE UPPER LEVEL TROUGH OVER THE
NORTHERN PLAINS AND SOUTH CENTRAL CANADA WILL DEEPEN AND DEVELOP
INTO A WELL DEFINED UPPER LEVEL OVER SOUTHERN MANITOBA THIS
AFTERNOON AND CONTINUE DEEPENING AS IT APPROACHES NORTHERN
MANITOBA.
LATER TONIGHT AND EARLY MONDAY...THE COLD FRONT WILL FINISH
MOVING THROUGH THE FORECAST AREA. THE UPPER LEVEL LOW WILL
CONTINUE DEEPENING OVER NW ONTARIO. THE LOW/MID LEVEL
FRONTOGENETICAL BAND IN NW WISCONSIN SHOULD EXIT TO THE EAST BY
AROUND DAWN. TEMPERATURES WILL DROP INTO THE MIDDLE AND LOWER 30S
TONIGHT. THE SYNOPTIC LIFT FROM THE UPPER LEVEL LOW WILL LIKELY
RESULT IN LIGHT RAIN AND SNOW MOVING INTO THE NW FORECAST AREA.
LITTLE OF ANY SNOW ACCUMULATION IS EXPECTED SINCE MUCH OF IT
SHOULD MELT...EITHER ON IMPACT OR LATER IN THE MORNING.
MONDAY...IT WILL BE MUCH COOLER DAY WITH BLUSTERY NW WINDS.
SUSTAINED WINDS OF 10 TO 20 MPH WILL DEVELOP BY THE
AFTERNOON...AND THERE COULD BE GUSTS UP TO 30 MPH. THE 850 HPA
TEMPERATURES WILL BE ABOUT -5 TO -6 DEGREES CELSIUS. HEAVY CLOUD
COVER AND THE COOL NW FLOW WILL PREVENT HIGHS FROM GETTING MUCH
HIGHER THAN THE LOW TO MIDDLE 40S. THERE WILL BE INCREASING
CHANCES OF COLD RAIN SHOWERS AS THE UPPER LOW DEEPENS AND MOVES TO
JUST NORTH OF KOOCHICHING COUNTY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
A DEEP AREA OF LOW PRESSURE WILL SETTLE SOUTHWARD INTO THE LAKE
SUPERIOR REGION MONDAY NIGHT AND TUESDAY. THE CLOSED H5 LOW WILL
REACH WESTERN LAKE SUPERIOR BY TUESDAY AFTERNOON. NUMEROUS
SHOWERS WILL ROTATE SOUTHWARD AROUND THE UPPER LOW...GENERALLY IN
THE FORM OF SNOW SHOWERS AT NIGHT AND RAIN OR SNOW SHOWERS DURING
THE DAY THROUGH THE MIDDLE OF THE WEEK. DEFINITELY COULD BE SOME
SLUSHY ACCUMULATION AT TIMES...ESPECIALLY IN THE NORTH. WOULD NOT
BE SURPRISED TO SEE A COUPLE EPISODES OF UP TO A COUPLE INCHES...
FOLLOWED BY SOME PARTIAL TO FULL MELTING DURING THE DAY. THIS
MASSIVE UPPER LEVEL TROUGH WILL EVENTUALLY LOSE ITS GRIP ON THE
AREA FROM THE MIDDLE TO THE END OF THE WORK WEEK. THE GEM AND TO
SOME EXTENT THE ECMWF ARE THE MOST AGGRESSIVE IN PUSHING THE
UPPER TROUGH EASTWARD THROUGH THE END OF THE WEEK...WITH THE GEM
BRINGING UPPER LEVEL RIDGING ALREADY INTO THE CWA BY 12Z FRIDAY.
THE GFS IS MUCH SLOWER AND DEEPER WITH THE UPPER LEVEL LOW.
STRONGLY FAVORING THE GEM/ECMWF SOLUTION...ESPECIALLY LATE IN THE
WEEK AND INTO THE WEEKEND. HIGH TEMPERATURES WILL REMAIN ON THE
COOL SIDE DURING THE WEEK...REACHING BACK INTO THE LOW TO MID 50S
ON THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 656 AM CDT SUN APR 19 2015
A LARGE AREA OF LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST INTO
THE NORTHLAND TODAY AND TONIGHT. ABUNDANT MOISTURE THROUGH THE
PLAINS WILL CONTINUE TO BRING AREAS OF LIGHT RAIN TODAY INTO
TONIGHT. CLOUD HEIGHTS ARE EXPECTED TO GRADUALLY DECREASE TO MVFR
OR EVEN IFR DURING THE MORNING...AND REMAIN THAT WAY THROUGH THE
AFTERNOON. SOME IMPROVEMENT IN CLOUD HEIGHTS WILL BE POSSIBLE FROM
THE WEST...AS SOMEWHAT DRIER AIR PUSHES EASTWARD BEHIND A COLD
FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 34 44 29 / 80 30 30 60
INL 49 32 40 28 / 90 40 60 60
BRD 56 35 43 31 / 80 20 40 40
HYR 58 37 46 30 / 80 80 30 60
ASX 58 37 47 32 / 80 80 20 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR
LSZ142>147.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...DAP
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
727 AM CDT Sun Apr 19 2015
.UPDATE...
Issued at 723 AM CDT SUN APR 19 2015
Made major adjustments to the forecast. Lowered PoPs considerably for
the rest of the morning south and west of a h7 vorticity lobe that
defines the back edge of showers over northern and into central
MO...roughly along an arc from St. Joseph to Sedalia. Trend of the
HRRR, RUC and even the NAM supports the above scenario. Convective
cluster over north central OK may graze the far southern counties
this afternoon so likely PoPs this area seems reasonable. So, for a
good portion of today many areas will see little in the way of
measurable rainfall. Still believe we`ll see a band of stratiform
type rain tied to the post-frontal baroclinic zone/deformation zone
that will slide ese across the CWA from late afternoon through this
evening.
&&
.SHORT TERM...(Today through Tuesday)
Issued at 407 AM CDT SUN APR 19 2015
Today - Tonight:
Today`s weather will be governed by the transition of an upper level
closed low to an open wave. Latest water vapor satellite imagery
shows the closed upper low has now shifted east into west central KS
early this morning. A shortwave trough digging into the Northern
High Plains will push this feature and its associated convection
through the CWA today with the rain ending from west to east this
evening.
Scattered showers and isolated thunderstorms will accompany a
couple mid level vorticity lobes as they rotate northeast across KS
and MO. No severe storms are expected today as less than impressive
MUCAPEs in the 400-800 J/kg range and bulk shear values around 25kts
will limit the strength of the storms. Like yesterday a few cells
could produce small hail during peak heating. Temperatures will
again be negatively impacted by the convection and cloud cover. A
more organized band of stratiform rain tied to post-frontal
frontogenesis and an elongated deformation zone overspreads the
region during the evening hours.
Monday - Tuesday:
The Northern Plains upper trough will gradually sharpen south and
shift east on Monday with strong subsidence spilling southeast on
the backside of the trough. Clearing skies will help offset cold air
advection yielding slightly below average temperatures both days.
The operational models are showing similar weak signals on Tuesday
that we`ll need to start considering the chance of some shower
activity. The models generate a series of weak strung out vorticity
lobes stretching southeast from NE through MO. Moisture will be the
main limiting factor so if any rain forms it will be light and
scattered.
.LONG TERM...(Wednesday through Saturday)
Issued at 407 AM CDT SUN APR 19 2015
Slightly below normal temperatures will stretch through the latter
half of the week as deep low pressure very slowly transitions SE
across the Great Lakes, and northwest flow aloft ushers cooler
temperatures into the region. At the same time a surface boundary
will drift southward through Wednesday, leaving the forecast area in
north to northeast surface flow and also helping to keep highs in
the lower to mid 60s. A few light showers and isolated storms are
possible over the southern tier of the CWA Wednesday and Wednesday
night as the front heads south, then a period of drier conditions is
expected on the north side of the boundary Thursday.
Southerly surface flow will eventually return by the end of the work
week ahead of a shortwave trough that will eject out of the desert
southwest and into the Plains by Friday. Widely scattered showers
and storms are possible as early as Friday afternoon, but are more
likely Friday night as the upper trough passes over the CWA. Timing
of this system is still a bit uncertain, and the probability of any
embedded storms will depend on how quickly southerly flow and low-
level moisture return to the region ahead of the shortwave trough.
At this time, the southern track of the associated surface low and
the environment in place ahead of the system suggests that the
potential for strong storms is very low. The clouds and any rain
associated with the system will keep temperatures down despite the
transition to southerly flow, so have kept highs mainly in the lower
60s through the end of the work week and into the weekend. Current
model trends show the wet weather clearing out by Saturday evening
and a dry Sunday, but will have to watch the potential for Friday`s
system to slow down and impact the coming weekend.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday Morning)
Issued at 635 AM CDT SUN APR 19 2015
Scattered showers and a few storms lifting north through northern MO
may define the last of the rain till late this afternoon and evening
when deformation band of stratiform type rain moves in. The onset of
gusty northwest winds will likely signal when this band will move in
with its MVFR ceilings. Till then think much of the day will only see
spotty hit/miss type showers. Thunderstorm risk looks minimal.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...MJ
LONG TERM...Laflin
AVIATION...MJ
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
620 AM CDT SUN APR 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT SUN APR 19 2015
THE UPPER LOW WHICH PRODUCED UP TO 52 INCHES OF SNOW IN COLORADO
HAS DRIFTED EAST INTO WRN KS THIS MORNING. RAIN AND THUNDERSTORMS
ARE FALLING UNDER THE LOW. A DEFORMATION ZONE OF RAIN AND
ISOLATED THUNDERSTORMS IS WEAKENING ACROSS NCNTL AND SWRN NEB
THIS MORNING. THE MODELS DRAG THIS AREA OF RAIN SOUTH AND OUT OF
THE FORECAST AREA BY 15Z-18Z. A STRONG COLD FRONT WITH SCATTERED
SHOWERS WILL DROP THROUGH THE FCST AREA THIS MORNING SETTING UP A
WINDY AND COOL DAY. NORTHWEST WINDS WILL INCREASE TO 20 TO 30 MPH
WITH GUSTS TO 40 MPH. THESE WINDS ARE ALREADY UNDERWAY IN THE
PANHANDLE.
THE STRONG WINDS BEND AROUND THE BLACK HILLS PRODUCING
CONVERGENCE ACROSS SHERIDAN AND CHERRY COUNTIES. THE HRRR SHOWS
SPRINKLES DEVELOPING BUT GIVEN THE VERY DRY AIR MOVING IN WITH
DEW POINTS FALLING INTO THE 20S BY NOON...NO MEASURABLE RAINFALL
WOULD BE EXPECTED.
HIGHS TODAY RISE INTO THE 50S WITH PARTLY CLOUDY SKIES. THE
MODELS ARE BRINGING IN COLD AIR ALOFT FROM AN UPPER LEVEL ACROSS
MANITOBA. THE RESULT IS H700MB TEMPERATURES FALL TO AROUND -10C
BY 21Z. SOME SUN IS EXPECTED BUT SKIES WOULD LIKELY CLOUD UP IN
THE AFTERNOON WITH THE COLD AIR ALOFT.
TONIGHT...THE UPPER LOW ACROSS WRN KS WILL LIFT INTO THE UPPER
MIDWEST AND BE ABSORBED THE A DISTURBANCE ACROSS WRN ONTARIO
TONIGHT. THIS WILL PULL PACIFIC HIGH PRESSURE INTO THE FCST AREA.
GENERALLY CLEAR SKIES ARE EXPECTED WITH LOWS IN THE 20S TO LOWER
30S. WINDS STAY UP AT 10 TO 15 MPH NEAR ONEILL WHERE THE WARMER
LOWS ARE EXPECTED.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 313 AM CDT SUN APR 19 2015
MONDAY INTO MID WEEK WILL SEE THE LOW PRESSURE SYSTEMS TO THE
NORTHEAST AND EAST MERGE NEAR/NORTH OF THE GREAT LAKES. MEANWHILE
NORTHWEST FLOW DOMINATES THE HIGH PLAINS AND AN UPPER LEVEL
TROUGH DIGS ACROSS THE PACIFIC COAST. THE LOW PRESSURE SYSTEM TO
THE NORTHEAST WILL DRAW SOME COOL AND DRY CANADIAN AIR TO THE
REGION. TEMPERATURES WILL BE THE MAIN FOCUS THROUGH MID WEEK AND
ARE TRICKY. THE DRY AIR MOVING SOUTH WILL ALLOW FOR DEW POINTS TO
FALL INTO THE TEENS AND 20S...HOWEVER WITH THE RECENT HEAVY
RAIN...THOUGHT MODELS ARE A TAD TO DRY SO DID RAISE SLIGHTLY BUT
COULD SEE THEM BEING HIGHER...ESPECIALLY BY WED. SKIES WILL
GENERALLY BE MOSTLY CLEAR...ALTHOUGH A COUPLE WEAK CLIPPERS MAY
BRING A BRIEF INCREASE OF CLOUDS. WITH MOSTLY CLEAR SKIES AND DRY
AIR TEMPS TO LIKELY FALL TO OR BELOW THE FREEZING MARK FOR THE
FIRST FEW DAYS OF THE WEEK...UNLESS BL MOISTURE ENDS UP BEING
MORE THAN EXPECTED FROM RECENT RAIN. MEANWHILE AFTERNOON SUN WILL
HELP OFFSET THE COOL CONDITIONS AND BE ABLE TO AID IN MIXING THE
BL...SEASONAL HIGHS /50S AND 60S/ EXPECTED. ONE CONCERN WITH
HIGHS IS THE COOL TEMPS ALOFT...WHICH MAY RESULT IN SOME
AFTERNOON CLOUDS DUE TO STEEP LAPSE RATES DEVELOPING. FAIRLY DRY
AIR AT THE SFC SO NOTHING EXPECTED TO REACH THE GROUND.
BY THE END OF THE WEEK THE WEST COAST TROUGH WILL BECOME AN OPEN
WAVE CROSSING THE DESERT SW/4 CORNERS. A TRANSITION FROM NW TO SW
FLOW WILL BRING A RETURN FOR WET WEATHER. MODELS NOT IN THE BEST
OF AGREEMENT ON TIMING...BUT DO PUSH THE WAVE ONTO THE
SOUTHERN/CENTRAL PLAINS BY THE WEEKEND. SHOULD SEE A BRIEF WINDOW
OF RETURN MOIST SOUTHEASTERLY FLOW AHEAD OF THE WAVE. THIS TRACK
AND THE INCREASE OF MOISTURE WILL FAVOR A CHANCE FOR
RAIN...ALBEIT BETTER FOR SOUTHERN ZONES THAN NORTHERN ZONES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 620 AM CDT SUN APR 19 2015
SATELLITE SUGGESTS THE DEFROMATION ZONE CAUSING MVFR CIGS/-RA MAY
HAVE STALLED ACROSS SOUTHERN NEBRASKA.
A COLD FRONT IS RACING SOUTH WHICH SHOULD DRY THIS AIR OUT ENDING
THE RAIN AND LOW CIGS. THIS SUGGESTS VFR WOULD BE WIDESPREAD
THROUGHOUT THE FCST AREA BY 15Z-18Z. VFR IS EXPECTED ALL AREAS
THEREAFTER.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
913 AM MDT SUN APR 19 2015
.UPDATE...
ADDED QUAY AND CURRY COUNTIES TO THE WIND ADVY FOR TODAY AND
TWEAKED UP WIND SPEEDS OUT THERE. OTHERWISE NO CHANGES.
&&
.PREV DISCUSSION...553 AM MDT SUN APR 19 2015...
.AVIATION...
12Z TAF CYCLE
SIGNIFICANT BACKDOOR COLD FRONT WILL SLIDE FARTHER SOUTH ACROSS THE
ERN PLAINS THIS MORN. NORTH WINDS OF 18 TO 30KT WITH GUSTS
BETWEEN 35 AND 45KT CAN BE EXPECTED ACROSS THE NE QUARTER OF NM...
THE STRONGEST IN THE VICINITY OF UNION COUNTY BETWEEN 14Z AND 19Z
SUNDAY. THE BACKDOOR FRONT WILL HELP TRIGGER ISOLATED AFTERNOON
AND EARLY EVE -SHRA AND -TSRA TODAY...MAINLY OVER THE NORTHERN MTS
AND ALONG THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN INCLUDING
KLVS...EAST SLOPES OF THE SANGRE DE CRISTOS MOST FAVORED. ISOLATED
EVEN HIGHER BASED CONVECTION POSSIBLE ALSO ACROSS THE SW MTS THIS
AFTN. LATE TONIGHT THERE IS A POSSIBILITY OF SOME NEAR MVFR CIGS
ACROSS AREAS E AND SE FROM THE E SLOPES OF THE SANGRE DE CRISTOS.
43
&&
.PREV DISCUSSION...337 AM MDT SUN APR 19 2015...
.SYNOPSIS...
AN OVERALL UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE NORTHERN
HIGH TERRAIN AND THE NORTHEAST PLAINS THROUGH ALL OF THIS WEEK. HIGH
TEMPERATURES WILL SLOWLY TREND BACK TOWARD NORMAL THROUGH THE MIDDLE
OF THE WEEK AHEAD OF THE NEXT STORM SYSTEM APPROACHING FROM THE WEST.
DRY SOUTHWEST WINDS WILL INCREASE WEDNESDAY AND THURSDAY FOR WESTERN
AND CENTRAL NEW MEXICO. THE CHANCES FOR SHOWERS AND THUNDERSTORMS
WILL INCREASE AGAIN FOR ALL AREAS FRIDAY AS THE CORE OF AN UPPER LOW
SLIDES OVERHEAD. COOLER TEMPERATURES WILL MOVE BACK INTO THE AREA
BEHIND THIS SYSTEM...WHILE THE CHANCES OF PRECIPITATION CONTINUE
OVER THE NORTH THROUGH NEXT WEEKEND.
&&
.DISCUSSION...
THE FINAL VESTIGES OF WRAP-AROUND PRECIP ARE IMPACTING THE FRONT
RANGE OF COLORADO THIS MORNING AS EVIDENCED BY WIDESPREAD SHOWERS
AND GUSTY NORTH WINDS. THIS ACTIVITY IS INDICATED BY THE 00Z/06Z
NAM AND HRRR GUIDANCE TO CLIP NORTHEAST NM THIS MORNING. QPF WILL
BE LIGHT WITH MOST AREAS REPORTING LESS THAN A TENTH. HIGHS AGAIN
TODAY WILL BE BELOW NORMAL ALL AREAS...WITH READINGS 10-15F BELOW
NORMAL FOR THE EAST. HIGH PRESSURE BUILDING DOWN THE FRONT RANGE
TONIGHT BEHIND THE DEPARTING UPPER LOW WILL HELP FORCE LIGHT GAP
WINDS INTO THE RIO GRANDE VALLEY LATE TONIGHT.
ONE LAST UPPER VORT TRANSLATION WITHIN NW FLOW BEHIND THE DEPARTING
WAVE WILL SLIDE OVER THE NORTHERN MTS AND NE PLAINS MONDAY. THIS
WILL FORCE ANOTHER ROUND OF AFTERNOON SHOWERS NEAR THE HIGH TERRAIN
AS FAR SOUTH AS I-40. AGAIN TEMPS WILL BE BELOW NORMAL WITH A SLIGHT
TREND TOWARD NORMAL FOR THE FAR WEST.
AN AMORPHOUS COMPLEX OF UPPER LEVEL LOW PRESSURE CURRENTLY TAKING
SHAPE ALONG THE WEST COAST WILL BECOME THE NEXT WEATHER PLAYER FOR
MID TO LATE WEEK. GUIDANCE SHOWS H5 HEIGHTS DEEPENING INTO A 562DM
LOW TUESDAY OVER SOUTHERN CALIFORNIA WITH A WEAK SHORTWAVE RIDGE
SLIDING OVER NM. THIS WILL TREND SHOWER AND WIND ACTIVITY DOWNWARD
FOR NM. A 90-110KT 300MB JET AXIS THEN CARVES SOUTHWARD ALONG THE
WEST COAST AND DEEPENS THE TROUGH INTO A TIGHTLY WOUND 550DM H5 LOW
OVER SOUTHERN CALIFORNIA THROUGH THURSDAY. THIS WILL INCREASE MID
LEVEL FLOW AND DEEPEN THE LEE SIDE TROUGH OVER EASTERN NM. WINDS
AND TEMPS WILL INCREASE OVER THE STATE WITH SOME POSSIBLE MARGINAL
FIRE WEATHER ISSUES NOTED WEDNESDAY AND/OR THURSDAY.
BEYOND THURSDAY THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE
TRANSLATION OF LOW PRESSURE OVER NM BY FRIDAY/SATURDAY AND INTO
NEXT WEEK. THE GFS AND ECMWF OPEN THE WAVE AND SLIDE DISORGANIZED
PRECIP OVER THE AREA...FOLLOWED BY A SERIES OF FAST MOVING WEAKLY
DEFINED SHORTWAVE TROUGHS AND RIDGES.
GUYER
&&
.FIRE WEATHER...
WHILE SOME POTENTIAL STILL REMAINS...AS IT CURRENTLY LOOKS THE RISK
OF A RETURN OF CRITICAL FIRE WX CONDITIONS THURSDAY AND FRIDAY HAS
DIMINISHED SOMEWHAT.
A BACK DOOR FRONT MOVING ACROSS THE EASTERN PLAINS THIS MORN AND
INTO THE AFTN WILL BRING INCREASINGLY STRONG AND GUSTY WINDS TO THE
NE PLAINS AND TO A LESSER DEGREE THE EAST CENTRAL PLAINS THIS MORN.
GUSTS NEAR 45 OR 50 MPH ARE POSSIBLE NEAR CLAYTON THIS MORN. WIND
SPEEDS ARE EXPECTED TO DECREASE SOMEWHAT THIS AFTN. CRITICAL FIRE WX
CONDITIONS NOT EXPECTED AS HUMIDITIES TO REMAIN TOO HIGH. AFTN TEMPS
WILL ONLY BE SLIGHTLY COOLER TODAY AS COMPARED TO SATURDAY BEHIND
THE FRONT. AS THE FRONT BACKS UP TO THE CENTRAL MTN CHAIN...EXPECT A
FEW HIGH BASED SHOWERS AND THUNDERSTORMS TO DEVELOP DUE TO UPSLOPE
FLOW...MORE SO ALONG THE EAST SLOPES OF THE SANGRE DE CRISTO MTNS
AND LESS SO FARTHER SOUTH. HUMIDITY RECOVERIES TONIGHT WILL BE GOOD
TO EXCELLENT MOST AREAS OUTSIDE OF WEST CENTRAL AND SW NM WHERE FAIR
TO GOOD RECOVERIES TO BE THE RULE. LOW TEMPS WILL BE A LITTLE ABOVE
NORMAL WEST AND CENTRAL...A BIT BELOW EAST. HIGH TEMPS ON SUNDAY
WILL REMAIN BELOW NORMAL ACROSS THE EAST DUE TO THE FRONTAL
PASSAGE...THOUGH WILL BE INCHING UP TOWARD NORMAL ACROSS THE WEST.
LATER MON...WEAK RIDGE ALOFT WILL DEVELOP ACROSS WESTERN NM...THOUGH
ENOUGH RESIDUAL MOISTURE WILL BE AROUND TO TRIGGER A FEW HIGH BASED
BUILDUPS AND VIRGA IN THE AFTERNOON HOURS. A FEW SPRINKLES MAY
ACTUALLY REACH THE GROUND ACROSS THE NORTHERN HIGH TERRAIN...THOUGH
THE BIGGER CONCERN MAY BE ERRATIC WIND GUSTS WITH ANY VIRGA ACROSS
WESTERN NM. OTHERWISE TEMPS SHOULD WARM TO AROUND 5 DEGREES OF
NORMAL EAST...VERY CLOSE TO NORMAL WEST.
THE BACK DOOR COLD FRONT EARLIER SCHEDULED TO ARRIVE LATER MON NIGHT
INTO TUE MORN HAS BEEN MARGINALIZED AND IN SOME MODELS ELIMINATED
FROM THE SCENE COMPLETELY. STILL MAY BE JUST ENOUGH MOISTURE AND
WEAK UPSLOPE TO CREATE A FEW SHOWERS AND THUNDERSTORMS TUE AFTN WITH
AID OF AFTN HEATING.
WED LOOKS TO BE BREEZY IN MANY AREAS...BUT FOR THE MOST PART THE
STRONGEST WINDS STILL ARE EXPECTED TO ARRIVE THU AND FRI. BUT
CRITICAL CONDITIONS HAVE SHRUNK SIGNIFICANTLY THU AND DO NOT APPEAR
AT ALL FOR FRI. THIS MAY ONLY BE A TEMPORARY REDUCTION AS FCST
MODELS SEEM TO BE IN TRANSITION AGAIN IN THEIR DEPICTION OF UPPER
LVL LOW PRESSURE EVOLUTION OFF TO OUR WEST. THE BACK DOOR FRONT WILL
BE REINFORCED ACROSS NE NM AND SOME THUNDERSTORMS MAY DEVELOP THERE
THU AFTN.
NO VENTILATION ISSUES ARE EXPECTED FOR THE NEXT 6 DAYS...WITH MAINLY
VERY GOOD TO EXCELLENT VENT RATES EXPECTED...THOUGH FAR NORTHEAST NM
MAY DROP INTO THE FAIR OR GOOD CATEGORIES MID TO LATE WEEK. SAT MAY
SEE SOME EROSION OF VENTILATION RATES.
43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ530-534-535.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
553 AM MDT SUN APR 19 2015
.AVIATION...
12Z TAF CYCLE
SIGNIFICANT BACKDOOR COLD FRONT WILL SLIDE FARTHER SOUTH ACROSS THE
ERN PLAINS THIS MORN. NORTH WINDS OF 18 TO 30KT WITH GUSTS
BETWEEN 35 AND 45KT CAN BE EXPECTED ACROSS THE NE QUARTER OF NM...
THE STRONGEST IN THE VICINITY OF UNION COUNTY BETWEEN 14Z AND 19Z
SUNDAY. THE BACKDOOR FRONT WILL HELP TRIGGER ISOLATED AFTERNOON
AND EARLY EVE -SHRA AND -TSRA TODAY...MAINLY OVER THE NORTHERN MTS
AND ALONG THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN INCLUDING
KLVS...EAST SLOPES OF THE SANGRE DE CRISTOS MOST FAVORED. ISOLATED
EVEN HIGHER BASED CONVECTION POSSIBLE ALSO ACROSS THE SW MTS THIS
AFTN. LATE TONIGHT THERE IS A POSSIBILITY OF SOME NEAR MVFR CIGS
ACROSS AREAS E AND SE FROM THE E SLOPES OF THE SANGRE DE CRISTOS.
43
&&
.PREV DISCUSSION...337 AM MDT SUN APR 19 2015...
.SYNOPSIS...
AN OVERALL UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE NORTHERN
HIGH TERRAIN AND THE NORTHEAST PLAINS THROUGH ALL OF THIS WEEK. HIGH
TEMPERATURES WILL SLOWLY TREND BACK TOWARD NORMAL THROUGH THE MIDDLE
OF THE WEEK AHEAD OF THE NEXT STORM SYSTEM APPROACHING FROM THE WEST.
DRY SOUTHWEST WINDS WILL INCREASE WEDNESDAY AND THURSDAY FOR WESTERN
AND CENTRAL NEW MEXICO. THE CHANCES FOR SHOWERS AND THUNDERSTORMS
WILL INCREASE AGAIN FOR ALL AREAS FRIDAY AS THE CORE OF AN UPPER LOW
SLIDES OVERHEAD. COOLER TEMPERATURES WILL MOVE BACK INTO THE AREA
BEHIND THIS SYSTEM...WHILE THE CHANCES OF PRECIPITATION CONTINUE
OVER THE NORTH THROUGH NEXT WEEKEND.
&&
.DISCUSSION...
THE FINAL VESTIGES OF WRAP-AROUND PRECIP ARE IMPACTING THE FRONT
RANGE OF COLORADO THIS MORNING AS EVIDENCED BY WIDESPREAD SHOWERS
AND GUSTY NORTH WINDS. THIS ACTIVITY IS INDICATED BY THE 00Z/06Z
NAM AND HRRR GUIDANCE TO CLIP NORTHEAST NM THIS MORNING. QPF WILL
BE LIGHT WITH MOST AREAS REPORTING LESS THAN A TENTH. HIGHS AGAIN
TODAY WILL BE BELOW NORMAL ALL AREAS...WITH READINGS 10-15F BELOW
NORMAL FOR THE EAST. HIGH PRESSURE BUILDING DOWN THE FRONT RANGE
TONIGHT BEHIND THE DEPARTING UPPER LOW WILL HELP FORCE LIGHT GAP
WINDS INTO THE RIO GRANDE VALLEY LATE TONIGHT.
ONE LAST UPPER VORT TRANSLATION WITHIN NW FLOW BEHIND THE DEPARTING
WAVE WILL SLIDE OVER THE NORTHERN MTS AND NE PLAINS MONDAY. THIS
WILL FORCE ANOTHER ROUND OF AFTERNOON SHOWERS NEAR THE HIGH TERRAIN
AS FAR SOUTH AS I-40. AGAIN TEMPS WILL BE BELOW NORMAL WITH A SLIGHT
TREND TOWARD NORMAL FOR THE FAR WEST.
AN AMORPHOUS COMPLEX OF UPPER LEVEL LOW PRESSURE CURRENTLY TAKING
SHAPE ALONG THE WEST COAST WILL BECOME THE NEXT WEATHER PLAYER FOR
MID TO LATE WEEK. GUIDANCE SHOWS H5 HEIGHTS DEEPENING INTO A 562DM
LOW TUESDAY OVER SOUTHERN CALIFORNIA WITH A WEAK SHORTWAVE RIDGE
SLIDING OVER NM. THIS WILL TREND SHOWER AND WIND ACTIVITY DOWNWARD
FOR NM. A 90-110KT 300MB JET AXIS THEN CARVES SOUTHWARD ALONG THE
WEST COAST AND DEEPENS THE TROUGH INTO A TIGHTLY WOUND 550DM H5 LOW
OVER SOUTHERN CALIFORNIA THROUGH THURSDAY. THIS WILL INCREASE MID
LEVEL FLOW AND DEEPEN THE LEE SIDE TROUGH OVER EASTERN NM. WINDS
AND TEMPS WILL INCREASE OVER THE STATE WITH SOME POSSIBLE MARGINAL
FIRE WEATHER ISSUES NOTED WEDNESDAY AND/OR THURSDAY.
BEYOND THURSDAY THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE
TRANSLATION OF LOW PRESSURE OVER NM BY FRIDAY/SATURDAY AND INTO
NEXT WEEK. THE GFS AND ECMWF OPEN THE WAVE AND SLIDE DISORGANIZED
PRECIP OVER THE AREA...FOLLOWED BY A SERIES OF FAST MOVING WEAKLY
DEFINED SHORTWAVE TROUGHS AND RIDGES.
GUYER
&&
.FIRE WEATHER...
WHILE SOME POTENTIAL STILL REMAINS...AS IT CURRENTLY LOOKS THE RISK
OF A RETURN OF CRITICAL FIRE WX CONDITIONS THURSDAY AND FRIDAY HAS
DIMINISHED SOMEWHAT.
A BACK DOOR FRONT MOVING ACROSS THE EASTERN PLAINS THIS MORN AND
INTO THE AFTN WILL BRING INCREASINGLY STRONG AND GUSTY WINDS TO THE
NE PLAINS AND TO A LESSER DEGREE THE EAST CENTRAL PLAINS THIS MORN.
GUSTS NEAR 45 OR 50 MPH ARE POSSIBLE NEAR CLAYTON THIS MORN. WIND
SPEEDS ARE EXPECTED TO DECREASE SOMEWHAT THIS AFTN. CRITICAL FIRE WX
CONDITIONS NOT EXPECTED AS HUMIDITIES TO REMAIN TOO HIGH. AFTN TEMPS
WILL ONLY BE SLIGHTLY COOLER TODAY AS COMPARED TO SATURDAY BEHIND
THE FRONT. AS THE FRONT BACKS UP TO THE CENTRAL MTN CHAIN...EXPECT A
FEW HIGH BASED SHOWERS AND THUNDERSTORMS TO DEVELOP DUE TO UPSLOPE
FLOW...MORE SO ALONG THE EAST SLOPES OF THE SANGRE DE CRISTO MTNS
AND LESS SO FARTHER SOUTH. HUMIDITY RECOVERIES TONIGHT WILL BE GOOD
TO EXCELLENT MOST AREAS OUTSIDE OF WEST CENTRAL AND SW NM WHERE FAIR
TO GOOD RECOVERIES TO BE THE RULE. LOW TEMPS WILL BE A LITTLE ABOVE
NORMAL WEST AND CENTRAL...A BIT BELOW EAST. HIGH TEMPS ON SUNDAY
WILL REMAIN BELOW NORMAL ACROSS THE EAST DUE TO THE FRONTAL
PASSAGE...THOUGH WILL BE INCHING UP TOWARD NORMAL ACROSS THE WEST.
LATER MON...WEAK RIDGE ALOFT WILL DEVELOP ACROSS WESTERN NM...THOUGH
ENOUGH RESIDUAL MOISTURE WILL BE AROUND TO TRIGGER A FEW HIGH BASED
BUILDUPS AND VIRGA IN THE AFTERNOON HOURS. A FEW SPRINKLES MAY
ACTUALLY REACH THE GROUND ACROSS THE NORTHERN HIGH TERRAIN...THOUGH
THE BIGGER CONCERN MAY BE ERRATIC WIND GUSTS WITH ANY VIRGA ACROSS
WESTERN NM. OTHERWISE TEMPS SHOULD WARM TO AROUND 5 DEGREES OF
NORMAL EAST...VERY CLOSE TO NORMAL WEST.
THE BACK DOOR COLD FRONT EARLIER SCHEDULED TO ARRIVE LATER MON NIGHT
INTO TUE MORN HAS BEEN MARGINALIZED AND IN SOME MODELS ELIMINATED
FROM THE SCENE COMPLETELY. STILL MAY BE JUST ENOUGH MOISTURE AND
WEAK UPSLOPE TO CREATE A FEW SHOWERS AND THUNDERSTORMS TUE AFTN WITH
AID OF AFTN HEATING.
WED LOOKS TO BE BREEZY IN MANY AREAS...BUT FOR THE MOST PART THE
STRONGEST WINDS STILL ARE EXPECTED TO ARRIVE THU AND FRI. BUT
CRITICAL CONDITIONS HAVE SHRUNK SIGNIFICANTLY THU AND DO NOT APPEAR
AT ALL FOR FRI. THIS MAY ONLY BE A TEMPORARY REDUCTION AS FCST
MODELS SEEM TO BE IN TRANSITION AGAIN IN THEIR DEPICTION OF UPPER
LVL LOW PRESSURE EVOLUTION OFF TO OUR WEST. THE BACK DOOR FRONT WILL
BE REINFORCED ACROSS NE NM AND SOME THUNDERSTORMS MAY DEVELOP THERE
THU AFTN.
NO VENTILATION ISSUES ARE EXPECTED FOR THE NEXT 6 DAYS...WITH MAINLY
VERY GOOD TO EXCELLENT VENT RATES EXPECTED...THOUGH FAR NORTHEAST NM
MAY DROP INTO THE FAIR OR GOOD CATEGORIES MID TO LATE WEEK. SAT MAY
SEE SOME EROSION OF VENTILATION RATES.
43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ530.
&&
$$
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
930 AM EDT SUN APR 19 2015
.SYNOPSIS...
HIGH PRESSURE EXTENDING OVER THE AREA FROM THE NORTH WILL SHIFT
OFFSHORE TODAY. A WARM FRONT WILL LIFT NORTHEAST ACROSS THE AREA
TONIGHT AS LOW PRESSURE MOVES INTO THE OHIO VALLEY. A COLD FRONT
WILL MOVE THROUGH FROM THE WEST EARLY TUESDAY FOLLOWED BY HIGH
PRESSURE WEDNESDAY. ANOTHER COLD FRONT WILL MOVE IN FROM THE
NORTHWEST THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 925 AM SUNDAY...MADE SOME SLIGHT ADJUSTMENTS TO NEAR-TERM
POPS AS LEADING EDGE OF PRECIPITATION SHIELD NOW MOVING INTO
NORTHEAST SOUTH CAROLINA AND WILL LIKELY BE A FEW MORE HOURS UNTIL
IT ARRIVES IN OUR CWA. THERE ARE A FEW ISOLATED SHOWERS OCCURRING
INLAND DUE TO SOME WEAK ISENTROPIC LIFT. GENERALLY FOLLOWED THE
3KM HRRR WHICH IS DOING A GOOD JOB OF DEPICTING THE RAINFALL. NO
CHANGES THROUGH THE AFTERNOON AS RAIN BECOMES WIDESPREAD AND
STEADY. CONVECTIVE DEVELOPMENT POTENTIAL SEEMS LIMITED BASED ON
CURRENT PARAMETERS AS BEST INSTABILITY OCCURRING MUCH FURTHER
SOUTHWEST ACROSS GEORGIA...ALABAMA AND THE FLORIDA PANHANDLE. NO
CHANGE TO TEMPERATURE FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 400 AM SUNDAY...LATEST GDNC CONTINUES TO INDICATE WET
CONDITIONS TONIGHT AND INCREASED POPS TO 100% ALL ZONES. DIFFLUENT
UPR FLOW AHEAD OF UPR TROF LIFTING OUT OF SRN PLAINS WILL INDUCE
LARGE SCALE ASCENT ACROSS AREA ALONG WITH DEEP MSTR PLUME FROM
GULFMEX. SFC WARM FRONT WILL APPROACH FROM SW AS DEVELOPING LOW
PRES MOVES INTO WRN OH VLY. WDSPRD SHOWERS AND PSBLY SCT TSTMS
EXPECTED TO GRADUALLY SPREAD SW TO NE ACROSS ERN NC OVERNIGHT. QPF
LOWERED SLIGHTLY BASED ON HPC AND LATEST MODEL BLEND...BUT MOST
AREAS STILL SEEING 1/2 TO 1 INCH.
PER NEAR-TERM...MARGINAL SVR THREAT FOR SW SECTIONS WITH SOME
POTENTIAL FOR ROTATING STORMS ALONG AND AHEAD OF WARM FRONT.
GENERALLY A HIGH SHEAR/LOW CAPE THREAT WITH WDSPRD CLOUDS AND PCPN
LIMITING INSTABILITY.
MIN TEMPS MAINLY LOW-MID 60S EVEN WITH WDSPRD RAIN.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 350 AM SUNDAY...BY MONDAY, THE UPPER TROUGH WILL SHIFT
EAST NEAR THE GREAT LAKES REGION WITH SEVERAL SHORTWAVES/
VORTICITY MAXIMA ROTATING AROUND THE BASE OF THE UPPER TROUGH. THE
SURFACE LOW WILL MOVE NORTHEAST INTO SOUTHEASTERN CANADA WITH THE
ATTENDANT COLD FRONT WELL NORTH OF THE REGION. THE BEST LIFT FROM
THE NORTHERN STREAM LIFTS WELL NORTH OF THE AREA WHILE THE
SOUTHERN STREAM JET REMAINS WELL SOUTHWEST OF EASTERN NC. THE BEST
MOISTURE ALSO LIFTS WELL NORTH OF EASTERN NC WITH FORECAST
SOUNDINGS INDICATING PWATS FALLING TO 1.20 INCHES MONDAY
AFTERNOON. GUIDANCE IS IN GOOD AGREEMENT WITH A SHORTWAVE/VORT MAX
MOVING THROUGH EASTERN NC MONDAY AFTERNOON/EVENING WHICH COULD
HELP SUPPORT OR ENHANCE ONGOING CONVECTION. 500 MB TEMPS FALL
FROM AROUND -11/-12 C SUNDAY TO -15/-16 C MONDAY AFTERNOON
INDICATING A FAVORABLE ENVIRONMENT FOR LARGE HAIL SHOULD STORMS
BECOME SEVERE. GIVEN SOUTHWESTERLY UNIDIRECTIONAL SHEAR, CAN ALSO
EXPECT A FEW SHOWERS/THUNDERSTORMS ALONG THE INLAND MOVING SEA-
BREEZE. AS DRY SLOTTING DEVELOPS MONDAY MORNING, CLOUD COVER WILL
DIMINISH ALLOWING EXCELLENT INSOLATION. INSTABILITY WILL BE
PLENTIFUL THOUGH THE ENVIRONMENT WILL A TRIGGER FOR CONVECTIVE
INITIATION, AND LACK VEERING LOW LEVEL WINDS. SPC MAINTAINS A
SLIGHT RISK FOR EASTERN NC THROUGH MONDAY EVENING/NIGHT. BIGGEST
THREAT WILL BE LARGE HAIL AND DAMAGING WIND GUSTS, THOUGH AN
ISOLATED TORNADO CANNOT BE RULED OUT.
INCREASED POPS TO CHANCE INLAND MONDAY AFTERNOON. HIGHS MONDAY
WILL BE IN THE LOW 80S INLAND AND MID 70S BEACHES.
MONDAY NIGHT/TUESDAY...COLD FRONT MOVES OFFSHORE LATE MONDAY NIGHT
AND EARLY TUESDAY MORNING WITH SLIGHTLY COOLER AND DRIER AIR
MOVING IN. TUESDAY`S HIGHS SHOULD BE IN THE MID 70S...BUT WITH
DEWPOINTS DOWN IN THE LOWER 50S BY AFTERNOON.
TUESDAY NIGHT/WEDNESDAY...HIGH PRESSURE BUILDS OVERHEAD WITH
MAINLY HIGH CLOUDS WEDNESDAY. COOL MORNING LOWS AROUND 50 REBOUND
TO AFTERNOON HIGHS IN THE MID 70S.
WEDNESDAY NIGHT/THURSDAY...ZONAL FLOW ALOFT CONTINUES AS A COLD
FRONT CROSSES THE REGION LATE THURSDAY. GUIDANCE IN MODEST
AGREEMENT FOR LIGHT SHOWERS/THUNDERSTORMS THURSDAY, THUS HAVE
INTRODUCED SLIGHT CHANCE POP WITH FRONTAL PASSAGE. ANOTHER COOL
MORNING THURSDAY WITH LOWS 50 TO 55...REBOUNDING INTO THE UPPER
70S THURSDAY AFTERNOON.
THURSDAY NIGHT/FRIDAY...DRY WEATHER BEHIND THE FRONT WITH SUNNY
COOLER WEATHER FOR FRIDAY. LOWS AGAIN IN THE 50 TO 55 DEGREE
RANGE WITH HIGHS UPPER 60S FAR NORTHEAST AND LOW 70S ELSEWHERE.
FRIDAY NIGHT/SATURDAY...ANOTHER SOUTHERN STREAM SYSTEM APPROACHES
LATE SATURDAY. HAVE INDICATED INCREASED CLOUD COVER AND A SMALL
CHANCE OF RAIN IN THE AFTERNOON.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH 12Z MONDAY/...
AS OF 700 AM SUNDAY...LIFT STRATUS CIGS DEVELOPED ALL TAF SITES
10-11Z WITH LIFR VSBYS AS WELL AT KPGV AND KISO. CONDITIONS
EXPECTED TO LIFT TO VFR BY AROUND 13Z. VFR PERSISTING INTO EARLY
AFTN...THEN CONDITIONS DETERIORATING. WIDESPREAD SHOWERS/ISOLD
TSTMS EXPECTED TO DEVELOP AND SPREAD SW TO NE ACROSS AREA THIS
AFTN INTO EARLY EVENING...WITH WDSPRD IFR CIGS LIKELY ALL TAF
SITES BY 00Z AND PERSISTING OVERNIGHT WITH VSBYS 3-5 SM IN SHRA.
LIGHT WINDS THIS MORNING WILL BECOME SE 10-15 KT THIS AFTN INTO
EVENING.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 355 AM SUNDAY...PRECIPITATION DIMINISHES MONDAY BUT SOME
ISOLATED STRONG TO SEVERE TSTMS MAY BE POSSIBLE, ESPECIALLY KPGV
AND KISO, MONDAY AFTERNOON AND EVENING WHICH COULD PRODUCE SUB-VFR
AVIATION CONDITIONS. HIGH PRESSURE BUILDS IN ACROSS EASTERN NC
TUESDAY INTO WEDNESDAY YIELDING MOSTLY VFR CONDITIONS. A WEAK
FRONT WILL MOVE SOUTH INTO EASTERN NC THURSDAY BUT WITH LIMITED
MOISTURE SO EXPECT MOSTLY VFR CONDITIONS THURSDAY.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 930 AM SUNDAY...NO MAJOR CHANGES TO THE CURRENT FORECAST
WITH LIGHT NORTHEAST WINDS INTO EARLY AFTERNOON...BECOMING E-SE AS
WARM FRONT LIFTS NORTH. WINDS INCREASE TO 15 TO 20 KNOTS BY THIS
EVENING. PRES GRAD WILL TIGHTEN TONIGHT WITH WARM FRONT MOVING IN
FROM SW...RESULTING IN WINDS BECOMING S-SW 20-25 KT. SEAS BUILDING
TO 4-6 FT OUTER WATERS LATE TODAY AND PEAKING 6-8 FT LATE TONIGHT.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 355 AM SUNDAY...GUSTY S/SW WINDS WILL BUILD SEAS TO 7-8 FEET
MONDAY. SEAS WILL REMAIN ELEVATED INTO TUESDAY MORNING AND CURRENT
SCA FOR ALL COASTAL WATERS WILL REMAIN IN EFFECT UNTIL 12Z TUESDAY.
HIGH PRESSURE WILL BUILD OVER THE NC WATERS TUESDAY INTO WEDNESDAY
WITH WINDS SHIFTING MORE WESTERLY, 5-15 KT. SEAS WILL DIMINISH TO
2-4 FT TUESDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT WILL MOVE
SOUTH INTO THE NORTHERN WATERS THURSDAY AND SHIFT SOUTH OF THE
WATERS THURSDAY NIGHT. WINDS VEER NORTHWEST BEHIND THE FRONT BUT
REMAIN 5-15 KT WITH SEAS 2-4 FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 8 AM EDT
TUESDAY FOR AMZ150-152-154-156-158.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...DAG
AVIATION...JBM/DAG
MARINE...CTC/JBM/DAG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
929 AM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 929 AM CDT SUN APR 19 2015
THE FORECAST FOR THE REMAINDER OF TODAY IS ON TRACK WITH THE
STRATUS FIELD OVERTAKING WESTERN AND CENTRAL NORTH DAKOTA EXPECTED
TO SLOWLY SCATTER WITH DIURNAL HEATING WITH RAIN SHOWER COVERAGE
INCREASING THROUGH THE AFTERNOON. THIS IS IN LINE WITH THE 12-13
UTC HRRR ITERATIONS.
UPDATE ISSUED AT 629 AM CDT SUN APR 19 2015
INITIAL BATCH OF WIDESPREAD RAIN CONTINUES TO PUSH OFF TO THE
EAST...THOUGH SECONDARY ROUND OF SCATTERED WRAP AROUND SHOWERS ARE
STARTING TO DEVELOP AND WORK INTO FAR NORTHWEST NORTH DAKOTA. HAVE
ADJUSTED POPS TO ACCOUNT FOR THIS. HAVE ALSO INCREASED CLOUD COVER
MAINLY OVER THE WEST AS CLOUDS CONTINUE TO STREAM IN BEHIND THE
LOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT SUN APR 19 2015
CONTINUED CHANCES FOR RAIN AND WINDY CONDITIONS THROUGH
SUNDAY...HIGHLIGHT THE SHORT TERM.
AN UPPER LEVEL TROUGH OVER THE NORTHERN PLAINS WILL CONTINUE TO
PROVIDE AMPLE MOISTURE AND INSTABILITY...PROLONGING CHANCES FOR
WIDESPREAD SHOWERS IN CENTRAL AND EASTERN AREAS OF THE STATE THROUGH
THE DAY. ADDITIONALLY...TEMPERATURES SLIGHTLY BELOW AVERAGE AND
STRONG NORTHWEST WINDS WILL ACCOMPANY THE DEEPENING TROUGH. THE
CURRENT 00Z MODEL SUITE PROVIDES GOOD AGREEMENT ON THE UPPER LEVEL
TROUGH DIGGING AND SLOWLY MOVING EASTWARD...PUSHING OVER
MINNESOTA/EASTERN MANITOBA AND CLOSING OFF BY 12Z MONDAY. NORTH
CENTRAL NORTH DAKOTA INTO THE JAMES RIVER VALLEY HAVE THE
POTENTIAL FOR A FEW SNOW FLAKES EARLY MONDAY MORNING...AS COLD AIR
FILTERING SOUTHWARD FROM CANADA IS EXPECTED TO DROP OVERNIGHT LOWS
TO JUST BELOW FREEZING.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 400 AM CDT SUN APR 19 2015
UPPER LOW WILL WORK ALONG THE MINNESOTA/ONTARIO BORDER ON MONDAY.
THIS SHOULD KEEP PRECIPITATION TO THE EAST OF OUR AREA THROUGH THE
DAY...THOUGH GUSTY NORTHWEST WINDS WILL CONTINUE IN THE WAKE OF
THE SYSTEM. A FAST MOVING WAVE WILL MOVE IN BEHIND THE SYSTEM LATE
TUESDAY NIGHT INTO EARLY WEDNESDAY WHICH MAY BRING A LITTLE LIGHT
PRECIPITATION TO CENTRAL NORTH DAKOTA...BUT WILL KEEP POPS LOW
WITH LACK OF MUCH MOISTURE TO WORK WITH. QUIET AND COOL CONDITIONS
ARE THEN EXPECTED WITH RIDGING TO THE WEST AND NORTHWESTERLY FLOW
OVER OUR AREA. MODELS START TO DISAGREE WITH THE POSITION OF THE
RIDGE AND WHETHER A FEW UPPER WAVES WILL MAKE IT THROUGH THE AREA
TOWARDS THE END OF THE WEEK. THEREFORE...WILL KEEP ANY
PRECIPITATION CHANCES ON THE LOW SIDE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 925 AM CDT SUN APR 19 2015
MVFR/VFR STRATUS WILL CONTINUE TO SPREAD ACROSS WESTERN AND
CENTRAL NORTH DAKOTA THIS MORNING. THIS DECK IS EXPECTED TO SLOWLY
LIFT AND SCATTER INTO THE AFTERNOON WITH RAIN SHOWER COVERAGE ALSO
INCREASING INTO THE AFTERNOON. STRONG NORTHWEST WIND GUSTS OF
30-35 KTS ARE ALSO FORECAST ACROSS WESTERN AND CENTRAL NORTH
DAKOTA TODAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...AC
LONG TERM...JJS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
959 AM EDT SUN APR 19 2015
.SYNOPSIS...
HIGH PRESSURE WAS OVER SOUTHEAST CANADA AND LOW PRESSURE WAS IN
ARKANSAS WITH A WARM FROM EXTENDING INTO SOUTH CAROLINA. THE LOW
AND WARM FRONT WILL MOVE NORTH TODAY AND TONIGHT. A COLD FRONT
CROSSES THE REGION ON MONDAY THEN HIGH PRESSURE BUILDS IN FOR
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 958 AM EDT SUNDAY...
FLOOD WATCHES REMAIN IN EFFECT FROM THIS AFTERNOON INTO TONIGHT.
A WARM FRONT WILL LIFT NORTH TODAY AND CROSS THE FORECAST AREA
TONIGHT. DEEPER MOISTURE AND HIGHER PWATS WILL INCREASE IN THE
WARM ADVECTION WITH THE NORTHWARD ADVANCE OF THE FRONT. THE RNK
WRF-ARW...HIRESW-ARW AND HRRR SHOWED WIDESPREAD RAIN LIFTING
NORTHWARD ACROSS OUR AREA. LOW LEVEL JET INCREASING TO 50-60 KNOTS
FROM THE SOUTHEAST WILL RESULT IN STRONG UPSLOPE AND ISENTROPIC
LIFT. THE STRONG WINDS THROUGH A DEEP LAYER WILL PROVIDE LARGE
HELICITY VALUES LATE THIS AFTERNOON INTO THIS EVENING. THE DAY
ONE CONVECTIVE OUTLOOK (SWODY1) PLACED A MARGINAL (5 PERCENT
CHANCE OF WIND) ACROSS SOUTHWEST PORTION OF CWA. MODIFIED
TEMPERATURES...DEW POINT AND POPS FR THIS MORNING INTO THIS
AFTERNOON. MORE ADJUSTMENTS AS THE DAY PROGRESSES...
AS OF 430 AM EDT SUNDAY...
WARM FRONT ASSOCIATED WITH A LOW IN ARKANSAS WILL MOVE NORTH TODAY
AND WILL CROSS THROUGH THE FORECAST AREA TONIGHT. STRONG SYNOPTIC
SCALE LIFT WILL PRODUCE WIDESPREAD RAIN ACROSS THE FORECAST AREA.
LOW LEVEL JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL
RESULT IN STRONG UPSLOPE AND ISENTROPIC LIFT. RAIN WILL SPREAD
INTO THE AREA FROM SOUTHWEST TO NORTHEAST BEFORE 18Z/2PM. MOST
LOCATIONS WILL HAVE ABOUT A 12 HOUR PERIOD OF LIGHT TO MODERATE
RAIN. HAVE PRECIPITATION ENDING FROM SOUTHWEST TO NORTHEAST AFTER
06Z/2AM.
TEMPERATURES STARTING THE DAY QUITE MILD. GRIDDED LAMP GUIDANCE
INDICATED STEADY AND POSSIBLY SLIGHTLY FALLING TEMPERATURES TODAY.
LITTLE CHANGE IN AIR MASS IS EXPECTED TONIGHT WITH TEMPERATURES
AND DEW POINTS REMAINING MAINLY IN THE 50S.
THE STRONG WINDS THROUGH A DEEP LAYER WILL PROVIDE LARGE HELICITY
VALUES LATE THIS AFTERNOON INTO THIS EVENING. THERE IS A LOW
CHANCE THERE COULD BE ENHANCED DIRECTIONAL SHEAR AS THE WARM FRONT
CROSSES. FOR NOW WILL LEAVE OUT ANY THUNDER.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 345 AM EDT SUNDAY...
THE NEW WEEK STARTS OFF WITH OUR REGION IN A WARM AND MOIST AIRMASS. AS
TEMPERATURES RISE WELL INTO THE 70S ON MONDAY THE ATMOSPHERE WILL
DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP. THE DYNAMIC ENVIRONMENT SUPPORTS THE CHANCE FOR
SOME SEVERE STORMS AND THE SPC SLIGHT RISK LOOKS TO BE ON TARGET ACROSS
OUR AREA WITH THE POTENTIAL FOR SVR WEATHER INCREASING EASTWARD WHERE
INSTABILITY WILL BE GREATER. IT WILL ALSO BE QUITE BREEZY WITH
EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER.
THE FRONT SHOULD BE CLEARING THE EASTERN ZONES EARLY MONDAY EVENING.
COLDER AIR WORKING IN ON NW WINDS BEHIND THE FRONT WILL COMBINE WITH
LOW LEVEL MOISTURE TO GENERATE SOME UPSLOPE SHOWERS ACROSS THE FAR
WESTERN SLOPES MONDAY NIGHT.
A BROAD CLOSED UPPER LOW BUILDING IN OVER THE NORTHEAST US WILL THEN
KEEP COOL...BREEZY...AND UNSETTLED WEATHER CONDITIONS ACROSS THE REGION
THROUGH MIDWEEK. TUESDAY LOOKS TO BE THE BEST CHANCE FOR A BREAK IN THE
ACTION AS ANY LINGERING SHOWERS ACROSS THE FAR WEST DISSIPATE BY EARLY
MORNING. BY WEDNESDAY THE NEXT COLD FRONT WILL BE ROTATING IN FROM THE
WEST WITH A CHANCE FOR SHOWERS AND MAYBE SOME THUNDER ESPECIALLY WEST
OF THE BLUE RIDGE. TEMPERATURES TUESDAY AND WEDNESDAY WILL BE RUNNING
AT OR SLIGHTLY BELOW NORMAL WITH UPPER 50S/LOWER 60S WEST OF THE BLUE
RIDGE AND MID 60S TO AROUND 70 EAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 350 PM EDT SATURDAY...
MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO ACROSS THE
PIEDMONT. FOLLOWING THIS DISTURBANCE COMES THE BONAFIDE COLDER AIR
WHICH PROMISES TO PUSH 850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE
REMAINDER OF THE WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH
GRADUALLY SHIFTS MORE TOWARD THE MID-ATLANTIC LATE IN THE
PERIOD...STRENGTHENING THE NORTHWEST FLOW ACROSS THE REGION...AND
ALLOWING 850MB TEMPS TO BOTTOM OUT ACROSS THE NORTH AROUND -5C BY
SATURDAY. THIS PATTERN WILL CONTINUE TO RESULT IN A SIGNIFICANT
TEMPERATURE DIFFERENCE FROM THE WESTERN MOUNTAINS WITH CLOUDS AND
VARIABLE CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST
FLOW ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN THE
UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY FROST/FREEZE
CONCERN AT THIS POINT.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
AS OF 745 AM EDT SUNDAY...
RAIN HAD ADVANCED INTO SOUTHWEST VIRGINIA AND WESTERN NORTH
CAROLINA THIS MORNING WITH CEILINGS LOWERING IN ADVANCE OF THE
RAIN. RAIN WILL BEGIN AT KBLF AROUND THE 12Z START OF THE TAF TIME
AND BY 16Z/NOON AT THE OTHER TAF SITES.
A STRONG SOUTHEAST LOW LEVEL JET WILL CONTINUE TO INCREASE TODAY
AND TONIGHT WHICH WILL BRING WIND GUSTS AS HIGH AS 30 KTS TODAY.
WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE BLUE
RIDGE...AFTER SUNSET THESE STRONG WINDS ARE NOT EXPECTED TO REACH
THE SURFACE. HAVE LLWS IN THE KDAN...KLWB AND KBCB TAFS AFTER
00Z/8PM.
A STRONG UPSLOPE FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE
REGION NORTH OF A STATIONARY FRONT TODAY. CEILINGS WILL LOWER TO
IFR BY THIS AFTERNOON AND WILL REMAIN LOW OVERNIGHT.
EXTENDED AVIATION...
A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE
AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE.
THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS
UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING.
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.HYDROLOGY...
AS OF 430 AM EDT SUNDAY...
HAVE EXPANDED THE FLOOD WATCH FOR MORE OF THE SOUTHERN BLUE RIDGE
AND FOR THE BLUE RIDGE AND ADJACENT EASTERN COUNTIES NORTH OF OF
ROANOKE. BUFKIT SOUNDINGS SHOWED A DEEP LAYER FROM THE SURFACE
THROUGH MID LEVELS OF THE ATMOSPHERE WITH SOUTHEAST WINDS...THAT
WILL BE INCREASING TO AROUND 50 KNOTS THIS AFTERNOON AND EVENING.
PRECIPITABLE WATER VALUES JUST ABOVE 1.5 INCHES WILL BE ADVECTED
INTO THE FORECAST AREA. THE STRONGEST LIFT AND HIGHEST RAINFALL
AMOUNTS WILL BE FROM 18Z/2PM THROUGH 06Z/2AM SO HAVE ADDED HEAVY
RAIN TO THE FORECAST ALONG THE BLUE RIDGE FOR THIS TIME FRAME.
TOTAL RAINFALL AMOUNTS WILL RANGE FROM 1 TO 3 INCHES THROUGH
12Z/8AM MONDAY. FLASH FLOOD GUIDANCE VALUES WERE ROUGHLY 1.5 TO
2.5 INCHES FOR 3 HOURS. SO THIS AMOUNT OF RAINFALL HAS THE
POTENTIAL TO PRODUCE FLOODING ON SMALL STREAMS AND CREEKS.
PROBABILISTIC GUIDANCE FOR MAINSTEM RIVERS SUGGESTS A SMALL
POSSIBILITY FOR MINOR FLOODING ALONG THE DAN RIVER AND NEW RIVER.
HOWEVER...THE IS HIGHLY DEPENDENT ON THE AMOUNT OF RAINFALL
THROUGH MONDAY MORNING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ009-012>017-032.
FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH LATE TONIGHT
FOR VAZ022>024-033>035.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/PC
HYDROLOGY...AMS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
551 AM CDT SUN APR 19 2015
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND MONDAY
ISSUED AT 327 AM CDT SUN APR 19 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SPLIT FLOW
OVER CENTRAL NORTH AMERICA EARLY THIS MORNING. IN THE SOUTHERN
STREAM...UPPER LEVEL LOW PRESSURE IS SPINNING OVER WESTERN
KANSAS/EASTERN COLORADO. AHEAD OF THIS FEATURE...SHOWERS AND
THUNDERSTORMS ARE OCCURRING FROM NEBRASKA TO LOUISIANA. EVEN
FURTHER NORTHEAST...MID-LEVEL MOISTURE TRANSPORT AND ILL-DEFINED
SHORTWAVES ARE ALSO CREATING SHOWERS AND A FEW THUNDERSTORMS FROM
WESTERN WISCONSIN INTO ILLINOIS. A COUPLE SPOTTY SHOWERS POPPED UP
SHORTLY AFTER MIDNIGHT OVER WOOD COUNTY TO THE DELLS...AND WILL HAVE
TO CARRY AN ISOLATED MENTION EARLY THIS MORNING ACROSS THE
I-39/ROUTE 51 CORRIDOR. IN THE NORTHERN STREAM...SHORTWAVE ENERGY
IS PROGRESSING EAST OVER THE NORTHWEST PLAINS. AS THESE FEATURES
MOVE EAST...PRECIP CHANCES AND TIMING ARE THE MAIN FORECAST CONCERNS.
TODAY...LOW PRESSURE OVER THE NORTHERN PLAINS WILL HEAD EAST WHILE
THE SOUTHERN STREAM LOW WILL LIFT NORTHEAST OVER THE CENTRAL
MISSISSIPPI VALLEY. WEAK SHORTWAVE ACTIVITY ROTATING ON THE EASTERN
PERIPHERY OF THE UPPER LOW OVER WESTERN KANSAS WILL LIFT NORTH
ACROSS THE WESTERN GREAT LAKES TODAY BUT INTO A MORE STABLE AND
DRIER AIRMASS. DESPITE THIS...THE HIGHER RES MODELS AND RUC DEPICT
SPOTTY SHOWERS DEVELOPING OVER CENTRAL AND NORTHEAST WISCONSIN THIS
MORNING WHICH BEAR SOME WEIGHT GIVEN THE SPOTTY SHOWERS POPPING UP
OVER THE DELLS AT THIS HOUR. AS A RESULT...QUITE DIFFICULT TO ADD
MUCH TEMPORAL RESOLUTION TO THE FORECAST THIS MORNING OTHER THAN
SAYING SLIGHT CHANCE OF A SHOWER. FORCING INCREASES OVER WESTERN
WISCONSIN DURING THE AFTERNOON WHEN A FGEN BAND MOVES ACROSS THAT
PART OF THE STATE. THE EASTERN EDGE OF THE INDUCED RAIN BAND WILL
LIKELY BE PUSHING INTO N-C WISCONSIN LATE IN THE AFTERNOON. AM
THINKING EASTERN WISCONSIN WILL REMAIN MOSTLY DRY DUE TO NE FLOW. THE
SLOWER ARRIVAL OF THE PRECIP WILL HELP TEMPERATURES RISE INTO THE
MID 60S OVER CENTRAL WI. CLOUD COVER AND EAST WINDS WILL SUPPORT
MUCH COOLER READINGS OVER EASTERN WI THOUGH.
TONIGHT...THE MEDIUM RANGE MODELS TRACK THE SOUTHERN STREAM SURFACE
LOW FROM CENTRAL ILLINOIS/INDIANA TO NORTHERN LOWER MICHIGAN. SOME
POSSIBILITY THAT THE LOW WILL TRACK WEST OF THIS LINE IN THE
MESOMODELS THOUGH. COMMA HEAD PRECIP FROM THIS LOW LOOKS TO MOVE
INTO NORTHEAST WISCONSIN BY MID TO LATE EVENING. MEANWHILE...RAIN
BAND ASSOCIATED WITH MID-LEVEL FGEN AHEAD OF THE NORTHERN STREAM
WAVE WILL SHIFT EAST THROUGH THE NIGHT ACROSS CENTRAL AND EASTERN
WISCONSIN. SEEMS LIKE A GOOD RECIPE FOR PERIODS OF RAIN ACROSS THE
REGION. LOWS RANGING FROM THE UPPER 30S NORTH TO MID 40S SOUTH.
MONDAY...THE FGEN RAIN BAND WILL GRADUALLY BE WEAKENING AS IT MOVES
EAST ACROSS EASTERN WISCONSIN DURING THE MORNING AND EXITS DURING
THE AFTERNOON. THE MID-LEVEL DRY SLOT WILL WORK OVERHEAD IN THE
WAKE OF THE RAIN DURING THE AFTERNOON AND MAY SEE A FEW PEAKS OF
SUNSHINE. OTHERWISE...BECOMING BREEZY WITH HIGHS IN THE MID 40S
NORTH TO LOW 50S SOUTH.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
ISSUED AT 327 AM CDT SUN APR 19 2015
CLOSED UPPER LOW WILL BRING UNSETTLED AND COOL CONDITIONS TO THE
REGION TUESDAY INTO WEDNESDAY. THE UPPER LOW WILL GRADUALLY PULL
AWAY THURSDAY AND FRIDAY...BUT CYCLONIC FLOW COULD STILL BRING A
SMALL CHANCE OF PRECIPITATION THURSDAY INTO FRIDAY ACROSS THE
FAR NORTH. DESPITE THE CALENDER STATING ITS LATE APRIL...SOME SNOW
IS IN THE FORECAST LATE AT NIGHT INTO THE MORNING HOURS. COULD BE SOME
MINOR ACCUMULATION ACROSS THE FAR NORTH TUESDAY MORNING AND AGAIN
WEDNESDAY MORNING.
BELOW NORMAL TEMPERATURES WILL CONTINUE INTO NEXT WEEKEND WITH DRY
CONDITIONS EXPECTED ON FRIDAY. ONLY MINOR CHANGES MADE TO PRECIPITATION
CHANCES AND TEMPERATURES DURING THE PERIOD.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 551 AM CDT SUN APR 19 2015
BROKEN MID-LEVEL CLOUDS THROUGH THIS AFTERNOON WITH
SPOTTY SHOWERS POSSIBLE. THEN AS LOW PRESSURE MOVES ACROSS THE
REGION TONIGHT...STEADY RAIN WILL MOVE ACROSS THE TAF SITES
BEGINNING THIS EVENING AND CONTINUING FOR MUCH OF THE NIGHT. EXPECT
CIGS AND VSBYS TO LOWER ONCE THE RAIN ARRIVES. IFR CIGS LOOK
LIKELY...AND SOME THREAT OF LIFR CIGS BASED ON UPSTREAM OBS OVER THE
NORTHERN PLAINS AND MOS GUIDANCE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
345 PM EDT SUN APR 19 2015
.DISCUSSION...
TONIGHT...SOUTHERN EDGE OF CONVECTIVE BAND MOVING INTO NE GULF AND
NORTH FL HAS BEEN WEAKENING RECENTLY AND HRRR/WRF MODELS INDICATE
THIS TREND WILL CONTINUE. HOWEVER SOME PRECIP/EMBEDDED STORM
ACTIVITY FROM THIS BAND MAY REACH LAKE COUNTY TOWARD SUNSET. AHEAD
OF THIS LINE HRRR CONTINUES TO SHOW SOME ISO/SCT STORMS FORMING
ESPECIALLY NEAR THE COAST FROM BOUNDARY COLLISIONS WITH THE EAST
COAST SEA BREEZE. LATEST SFC OBS SHOW THE SEA BREEZE HAS BEEN ABLE
TO HOLD ON RIGHT ALONG THE COAST AT SOME LOCATIONS. HOWEVER AN
INCREASING LOW LEVEL S/SW FLOW INTO LATE DAY MAY PUSH WHAT SEA
BREEZE REMAINS OFFSHORE. IF SO CONVECTIVE ACTIVITY MAY BE LIMITED
INTO THIS EVENING. FOR NOW WILL HOLD ONTO A CHANCE FOR STORMS INTO
THE EVENING MAINLY ALONG THE COAST. IF ANY BOUNDARY COLLISIONS DO
OCCUR ISO STRONG STORMS NOT OUT OF THE QUESTION.
RAIN CHANCES END BY MIDNIGHT WITH ANY SHOWERS/STORMS PUSHING
OFFSHORE. OVERNIGHT LOWS WILL BE IN THE UPPER 60S TO LOW 70S.
MONDAY...MODELS SHOW ANOTHER MID LEVEL S/W PUSHING THROUGH THE NRN
GULF AHEAD OF WEAK FRONT MOVING INTO THE SOUTHEAST STATES. THIS
DISTURBANCE WILL LIKELY LEAD TO ANOTHER BAND OF CONVECTION
DEVELOPING OVER THE CENTRAL/EASTERN GULF SHIFTING EASTWARD TOWARD
THE FL PENINSULA IN THE EARLY MORNING HOURS. NAM AND TO A DEGREE THE
WRF SHOW THIS BAND DEVELOPING FARTHER NORTH AND PUSHING ACROSS MUCH
OF THE REGION INTO THE AFT WHILE THE GFS/ECMWF KEEP GREATEST RAIN
CHANCES/MOISTURE SOUTH OF ORLANDO. HAVE LEANED TOWARD A BLEND FOR
NOW WHICH KEEPS RAIN CHANCES FAIRLY CONSISTENT AROUND 50-60 PERCENT.
SOME STRONG TO ISO SEVERE STORMS POSSIBLE IF ENOUGH HEATING CAN
OCCUR OUT AHEAD OF ANY CONVECTION OVER THE GULF. MAIN THREAT WOULD
BE STRONG WIND GUSTS AND HAIL.
TUE...A COOL FRONT WILL SETTLE SOUTH ACROSS CENTRAL FL BRINGING SOME
DRIER AIR AND TEMPERATURES MORE SEASONABLE FOR THIS TIME OF YEAR IN
THE LOW TO MID 80S. HAVE LOWERED RAIN CHANCES ACROSS THE NORTH TO 20
PERCENT NORTH OF ORLANDO AND THIS MAY BE GENEROUS. MOISTURE LINGERING
ACROSS THE SOUTH WILL KEEP RAIN CHANCES 40 TO 50 PERCENT FROM
OKEECHOBEE TO THE TREASURE COAST.
REST OF WEEK (PREVIOUS)...DEPARTURE OF STRONG UPR WIND MAXIMA WL BRING
EVOLUTION TO ZONAL PATTERN WITH BROAD WEAK HIGH DOWNSTREAM ACTING
TO STABILIZE AIRMASS...WITH SOME DRYING AS WELL OVER THE NORTH AT
MIDWEEK. AFTERNOON BOUNDARY INTERACTION AND SUFFICIENT LL MOISTURE
WL FORCE SOME SHOWERS AND SLOW MOVING STORMS WED-THU WITH AT LEAST
MENTIONABLE RAIN CHCS IN THE EXTENDED FCST LACKING ANY NOTABLE
PATTERN CHG AND OR DRYING OF THE AMBIENT AIRMASS.
&&
.AVIATION...
TEMPO IFR/MVFR CONDS IN ISO/SCT SHRA/TSRA MAINLY TOWARD THE COAST
WILL OCCUR AHEAD OF APPROACHING BAND OF CONVECTION THAT IS
WEAKENING OVER THE NE GULF. THIS BAND MAY REACH AREAS WEST OF I-4
TOWARD SUNSET...PRODUCING ADDITIONAL REDUCTIONS TO CIG/VIS MAINLY AT
KLEE. CONVECTION THEN DIMINISHING/PUSHING OFFSHORE INTO LATE EVENING
WITH MAINLY VFR OVERNIGHT. DEEP MOISTURE AND AN APPROACHING
DISTURBANCE ALOFT WILL KEEP HIGH RAIN CHANCES IN THE FORECAST FOR
TOMORROW WITH SCT-NMRS SHRA/TSRA PRODUCING TEMPO IFR/MVFR CONDS INTO
THE AFT.
&&
.MARINE...
TONIGHT-MONDAY...S/SW WINDS UP TO 10-15 KNOTS WILL BECOME MORE W/SW
INTO LATE MON AS A WEAK FRONTAL BOUNDARY PUSHES INTO THE SOUTHEAST
STATES. SEAS WILL REMAIN AROUND 2-4 FEET. MAIN CONCERN WILL CONTINUE
TO BE FOR OFFSHORE MOVING STORMS THIS EVENING AND TOMORROW AFT/EVE...
PRODUCING STRONG GUSTY WINDS.
TUE-THU...WEAK FRONT PROGGED TO MOVE DOWN THE FL PENINSULA TUE SO
WIND FLOW WILL BE W/NW 10 KNOTS. FLOW BEHIND THE FRONT MID WEEK WILL
BECOME ONSHORE AROUND 10 KNOTS. SEAS WILL REMAIN 4 FEET OR LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 69 84 68 80 / 40 40 20 20
MCO 70 87 69 83 / 20 50 20 30
MLB 71 87 70 82 / 40 60 30 30
VRB 70 87 70 83 / 40 60 30 50
LEE 70 84 68 82 / 20 50 20 20
SFB 70 85 69 83 / 30 50 20 20
ORL 71 86 69 83 / 20 50 20 30
FPR 69 87 70 83 / 40 60 30 50
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...WEITLICH
LONG TERM....KELLY
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
127 PM EDT SUN APR 19 2015
...TORNADO WATCH TIL 8PM I-10 CORRIDOR NORTHWARD...
...POTENTIAL FOR A FEW STRONG/SEVERE STORMS AGAIN MONDAY...
.NEAR TERM...THROUGH TONIGHT...
WATER VAPOR SHOWING AN IMPRESSIVE SHORTWAVE THAT WILL MOVE
EASTWARD TOWARD AND OVER FORECAST AREA THROUGH THIS EVENING. BAND
OF SHOWERS AND EMBEDDED THUNDERSTORMS WILL ACCOMPANY WAVE THIS
AFTERNOON. SUFFICIENT INSTABILITY AND DEEP-LAYER SHEAR AHEAD OF
SYSTEM TO SUPPORT A FEW STRONG OR SEVERE STORMS EMBEDDED WITHIN
THE LINE...MAINLY BOWING LINE SEGMENTS WITH DAMAGING WIND
POTENTIAL...THOUGH AN ISOLATED TORNADO IS ALSO POSSIBLE. IN
ADDITION...STARTING TO SEE CONVECTION BREAK OUT AHEAD OF SYSTEM
OVER OUR WRN COUNTIES. GIVEN THE ENVIRONMENT IN PLACE...THERE IS
POTENTIAL FOR A FEW DISCRETE STRONG/SEVERE CELLS TO DEVELOP THIS
AFTERNOON. LATEST HRRR SUGGESTS THIS ACTIVITY COULD INTENSIFY AS
IT SPREADS NORTHEAST OVER THE NEXT FEW HOURS. TORNADO WATCH IS IN
EFFECT FOR AREAS FROM THE I-10 CORRIDOR NORTHWARD TIL 8PM.
BAND OF SHOWERS/STORMS WILL MOVE QUICKLY NORTH AND EAST ACROSS
FORECAST AREA BETWEEN 2PM AND 7PM...THEN MOVE OFFSHORE. LOW TEMPS
EXPECTED TO BE 68-70 MOST LOCATIONS.
SHORT TERM...MONDAY THROUGH TUESDAY NIGHT... FOR MONDAY...COLD
FRONT APPROACHES FROM THE NORTHWEST. MORE WESTERLY FLOW AT LOW AND
MID LEVELS BRINGS IN DRIER AIR...AND AS A RESULT THE MODELS
DEVELOP CONSIDERABLY LESS PRECIP COVERAGE MONDAY AFTERNOON
COMPARED TO THIS AFTERNOON. WILL MAINTAIN 30-40 POP FOR MONDAY
AFTERNOON. ONCE AGAIN SPC HAS SLIGHT RISK OF SEVERE STORMS OVER
OUR AREA...AND ONCE AGAIN WE SHOULD HAVE FAVORABLE COMBINATION OF
MODERATE CAPE AND SUFFICIENT DEEP LAYER SHEAR. LOW-LEVEL WINDS
WILL BE MORE SW AHEAD OF COLD FRONT...AND THIS WILL REDUCE
HELICITY...SO PRIMARY THREAT WILL BE STRONG WINDS. WARM AGAIN
MONDAY WITH HIGHS IN THE MID 80S ACROSS THE FORECAST AREA.
COLD FRONT MOVES ACROSS THE AREA LATE MONDAY NIGHT...WITH SOMEWHAT
COOLER DRIER CONDITIONS TUESDAY. CURRENT FORECAST HIGH TEMPS OF
UPPER 70S SE GA...AROUND 80 I-10 CORRIDOR...AND LOW 80S GNV/OCF
LOOKS FINE. COOLER NIGHT TUESDAY NIGHT WITH LOW TEMPS 55-60 ACROSS
THE AREA...EXCEPT LOW 60S COAST.
LONG TERM...WEDNESDAY THROUGH SUNDAY...
GIVEN THE HIGH IMPACT THREATS THROUGH MONDAY...DID NOT MAKE
SIGNIFICANT CHANGES TO THE MEDIUM RANGE GIVEN NOT MUCH
SIGNIFICANT CHANGE IN LATEST MODEL GUIDANCE. STILL EXPECT WEAK
SURFACE RIDGING AND ZONAL FLOW ALOFT THROUGH THE END OF THE
WORKWEEK...WITH SOME INCREASE IN TEMPS AS WELL AS SLIGHT CHANCES
FOR SHOWERS WITH SEA BREEZES. BETTER RAIN CHANCES MAY STILL COME
OVER WEEKENDD... THOUGH SOME UNCERTAINTY AS TO TRACK OF NEXT WEEK
SYSTEM AND WHERE THE MORE WIDESPREAD PRECIPITATION WILL END UP.
&&
.AVIATION...MAIN SQUALL LINE WELL WEST OF THE LOCAL FIELDS WITH
GAINESVILLE MOST LIKELY TO FEEL ITS IMPACT. EXPECT CONVECTION TO
MOVE IN THERE BETWEEN 19-21 UTC WITH CEILINGS IN THE 2.5 KFT RANGE.
THE COAST FIELDS FROM SAINT AUGUSTINE THROUGH THE JACKSONVILLE METRO
AREA TO SAINT SIMONS ISLAND SHOULD SEE A CONVERGENCE BETWEEN THE
DOMINANT SOUTHWESTERLY LOW LEVEL FLOW PATTERN AND THE DEVELOPING
ATLANTIC SEA BREEZE FRONT. EXPECT STRONG TO POSSIBLY SEVERE
CONVECTION TO FIRE UP ALONG THE ATLANTIC COAST WITH CEILINGS BETWEEN
2.5-5 KFT. THESE STORMS SHOULD PASS OFFSHORE THIS EVENING BY 23OO
UTC AS THE WEAKENING SQUALL LINE MAKES ITS RUN AT THE COAST.
&&
.MARINE....WINDS WILL GRADUALLY INCREASE AND VEER OUT AHEAD OF
APPROACHING COLD FRONT ALTHOUGH NO HEADLINES EXPECTED THRU MONDAY.
THE COLD FRONT CROSSES THE WATERS MONDAY NIGHT BRINGING A BRIEF
PERIOD OF CONDITIONS APPROACHING ADVISORY CRITERIA IN THE
OFFSHORE COMPONENT. SCATTERED TO NUMEROUS AFTERNOON AND EVENING
SHOWERS/TSMS THRU MONDAY... WITH STRONG WINDS POSSIBLE WITH THE
MORE INTENSE STORMS. HIGH PRESSURE QUICKLY BUILDS IN BEHIND THE
FRONT TUE WITH WIND/SEAS DECREASING FOR REMAINDER OF WEEK.
.RIP CURRENTS...MODERATE RISK THIS AFTERNOON...LOW RISK MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 67 85 60 77 / 30 30 20 10
SSI 69 82 65 75 / 30 30 20 10
JAX 69 85 64 79 / 30 30 20 10
SGJ 70 83 67 77 / 30 40 20 10
GNV 68 85 65 81 / 20 40 20 10
OCF 69 85 66 82 / 20 40 20 10
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
WOLF/SANDRIK/WALKER
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
425 PM EDT SUN APR 19 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA MONDAY. THE FRONT WILL CROSS THE
REGION MONDAY NIGHT AND WILL SHIFT OFFSHORE BY EARLY TUESDAY. HIGH
PRESSURE WILL THEN PREVAIL TUESDAY INTO THURSDAY. A WEAK COLD FRONT
WILL DROP THROUGH THE AREA THURSDAY NIGHT...THEN WILL STALL JUST
SOUTH OF THE REGION LATE WEEK. A STORM SYSTEM WILL AFFECT THE REGION
NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
REST OF THE AFTERNOON AND EVENING...THUNDERSTORMS ARE CURRENTLY
PROGRESSING THROUGH SOUTHEAST GEORGIA AND THE TORNADO WATCH HAS
BEEN EXPANDED TO INCLUDE CHARLESTON COUNTY...BERKELEY
COUNTY...CHARLESTON HARBOR...AND AMZ350. THE ENVIRONMENT HAS SET
UP MUCH LIKE WAS ANTICIPATED THIS MORNING. TEMPERATURES ACROSS
SOUTHEAST GEORGIA HAVE WARMED INTO THE LOW 80S IN MANY AREAS WITH
DEW POINTS IN THE LOW 70S. SURFACE BASED CAPE VALUES ARE IN THE
2000-2500 J/KG RANGE AND 0-3 KM SHEAR IS ON THE ORDER OF 30-35 KT.
THE NEAR SURFACE FLOW IS BACKED TO MORE SOUTHEASTERLY WHICH IS
ENHANCING THE STORM RELATIVE HELICITY VALUES INTO THE 200 RANGE.
CURRENT RADAR TRENDS SHOW LINEAR CONVECTION JUST TO THE WEST WITH
MORE DISCRETE CELLULAR DEVELOPMENT FURTHER SOUTH ACROSS THE
NORTHERN EXTENT OF JAX/S FORECAST AREA. THE CONVECTIVE MODE WILL
CONTINUE TO FAVOR LINEAR SEGMENTS AND WITH THE SHEAR/INSTABILITY
COMBINATION EMBEDDED SUPERCELL ELEMENTS ARE EXPECTED. HI-RES MODEL
RUNS SUCH AS THE HRRR CONTINUE TO SHOW AN ELEVATED MIXED LAYER
SIGNATURE IN THE SOUNDINGS. DAMAGING WINDS CONTINUE TO BE THE
PRIMARY THREAT...THOUGH LARGE HAIL CANNOT BE TOTALLY RULED OUT.
THERE ALSO REMAINS THE THREAT OF BRIEF TORNADOES SPINNING UP
WITHIN ANY QLCS SEGMENTS. TIMING IS LARGELY UNCHANGED...WITH THE
CONVECTION REACHING THE SAVANNAH METRO AREA RIGHT NOW AND THEN
WILL REACH THE CHARLESTON AREA AROUND 22Z-23Z.
TONIGHT...THE LINE OF CONVECTION WILL PUSH EAST OF THE AREA AND
OFFSHORE RIGHT AROUND MIDNIGHT. THEREAFTER...MODEL TIME HEIGHTS AND
SOUNDING SHOWS NOTABLE MID/UPPER LEVEL DRYING AND THE REMAINDER OF
THE NIGHT IS EXPECTED TO BE DRY. STRATUS WILL FILL IN OVERNIGHT AND
OVERCAST SKIES WILL PREVAIL. ANOTHER VERY WARM NIGHT IS
EXPECTED...WITH YET ANOTHER PERSISTENCE FORECAST FOR LOWS. THE
FORECAST FEATURES MID TO UPPER 60S AGAIN.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
THE UPSTREAM LONGWAVE TROUGH WILL PUSH A STRONG COLD FRONT TOWARD
THE REGION MONDAY. AFTER A RAIN-FREE MORNING...THE CHANCE FOR
THUNDERSTORMS WILL INCREASE DURING THE AFTERNOON. DESTABILIZATION
SUPPORTED BY FEATURING MLCAPES INCREASING TO 2000-3000 J/KG...FAIRLY
UNIDIRECTIONAL 0-6 KM BULK SHEAR 40-50 KNOTS AND SOME DYNAMIC
FORCING FOR ASCENT PROVIDED BY AN APPROACHING SHORTWAVE TROUGH
ALOFT/LARGE SCALE HEIGHT FALLS PRODUCED BY THE PARENT LONGWAVE
TROUGH WILL SUPPORT THE POTENTIAL FOR ANOTHER ROUND OF ORGANIZED
THUNDERSTORMS PRODUCING SEVERE WEATHER. DOWNDRAFT CAPES AROUND 1500
J/KG AND DRIER AIR ALOFT WILL SUPPORT DAMAGING WIND GUSTS AND EVEN
LARGE HAIL.
THUNDERSTORM COVERAGE REMAINS UNCERTAIN MONDAY AFTERNOON/EVENING.
WHILE ORGANIZED THUNDERSTORMS COULD PUSH INTO THE REGION FROM THE
WEST...STRONG THUNDERSTORMS SOUTH OF THE REGION COULD LIMIT COVERAGE
OVER THE REGION. ALSO POSSIBLE...STRONGEST THUNDERSTORMS COULD
REMAIN JUST NORTH OF THE REGION. FOR NOW...CAPPED POPS AT 50 PERCENT
OR LESS...HIGHEST INLAND/NORTH...BUT ADJUSTMENTS COULD YET BE
REQUIRED. WILL CONTINUE TO HIGHLIGHT THE SEVERE WEATHER THREAT
WITHIN THE HAZARDOUS WEATHER OUTLOOK.
THE COLD FRONT WILL CROSS THE REGION MONDAY NIGHT. THE CHANCE FOR
THE SHOWERS/THUNDERSTORMS WILL GRADUALLY WANE...AND THE POTENTIAL
FOR SEVERE WEATHER WILL ALSO DIMINISH WITH DIURNAL STABILIZATION.
MUCH DRIER HIGH PRESSURE WILL PREVAIL TUESDAY AND WEDNESDAY. HIGHS
WILL AVERAGE IN THE MID TO UPPER 70S...AND LOWS IN THE 50S WILL BE
COMMON TUESDAY NIGHT.
GUIDANCE PULLS VARYING DEGREES OF MID/HIGH LEVEL MOISTURE INTO THE
REGION WITHIN A ZONAL FLOW AHEAD OF AN APPROACHING COLD FRONT
WEDNESDAY. WHILE CLOUD COVER SHOULD INCREASE...CONVECTIVE
PRECIPITATION PRODUCED BY THE GFS APPEARS OVERDONE. THUS...HELD POPS
BELOW 15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A ZONAL PATTERN WILL EXIST MUCH OF THE PERIOD. A WEAK BACK DOOR COLD
FRONT DROPS THROUGH THE AREA THURSDAY NIGHT. THE FRONT WILL STALL TO
THE SOUTH BEFORE LIFTING BACK NORTH AS A WARM FRONT FRIDAY NIGHT AND
SATURDAY. A PRONOUNCED SHORTWAVE EMBEDDED IN THE QUASI-ZONAL FLOW
WILL MOVE THROUGH SATURDAY NIGHT ACCOMPANIED BY A COLD FRONT.
PRECIPITATION POSSIBLE STARTING FRIDAY NIGHT AND CONTINUING INTO
SATURDAY NIGHT. TEMPS WILL BE MODERATED BY INCREASING CLOUD COVER
AND WEAK COLD ADVECTION.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
MVFR CEILINGS HAVE RETURNED TO BOTH TERMINALS EARLY THIS AFTERNOON
AND THE MAIN FORECAST ISSUE THROUGH THE EVENING WILL BE TIMING
THUNDERSTORMS INTO THE FORECAST. BASED ON CURRENT RADAR TRENDS AND
HI-RES MODEL GUIDANCE...IT LOOKS LIKE THUNDER WILL REACH KSAV AND
IMPACT THE TERMINAL BETWEEN 20Z-22Z. HAVE GONE WITH IFR CONDITIONS
IN THUNDER WITH GUSTY WINDS TO ALMOST 40 KT BASED ON SOME UPSTREAM
OBSERVATIONS. AT KCHS...THUNDER WILL ARRIVE LATER AND IT IS
UNCLEAR IF IT WILL BE AS STRONG AS IT IS EXPECTED AT KSAV. HAVE
GONE WITH 22Z-00Z AT KCHS WITH IFR CONDITIONS AND SLIGHTLY LESSER
WIND GUSTS. ONCE THE CONVECTION MOVE EAST OF THE TERMINALS THERE
WILL BE A BIT OF A LULL UNTIL IFR CEILINGS ARE PROGGED TO RETURN
AFTER MIDNIGHT. BOTH SITES GET PREVAILING IFR CEILINGS THROUGH THE
LATE NIGHT...SCATTERING OUT MONDAY MORNING.
EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS WITHIN SCATTERED
SHOWERS/TSTMS POSSIBLE AT BOTH TERMINALS MONDAY AFTERNOON AND
EVENING. OTHERWISE...VFR THROUGH THE PERIOD.
&&
.MARINE...
THIS EVENING AND TONIGHT...THE MAIN FORECAST ISSUE WILL BE THE LINE
OF THUNDERSTORMS EXPECTED TO MOVE THROUGH THE LOCAL WATERS THIS
EVENING AND THE FIRST PART OF TONIGHT. THESE STORMS COULD BE QUITE
STRONG...PRODUCING 35 KT OR GREATER WINDS GUSTS...FREQUENT
LIGHTNING...AND EVEN THE POTENTIAL FOR A TORNADIC WATERSPOUT. THE
STORMS WILL IMPACT THE GEORGIA AND SOUTHERN SOUTH CAROLINA WATERS
THROUGH ABOUT 10 PM...AND THEN MOVE OFF THE CHARLESTON COUNTY WATERS
JUST AFTER MIDNIGHT. OTHERWISE...SOUTHERLY FLOW WILL PREVAIL AND
THEN TURN MORE SOUTHWESTERLY LATE. OUTSIDE OF CONVECTION WINDS WILL
TOP OUT IN THE 15-20 KT RANGE AND NO SMALL CRAFT ADVISORIES ARE
ANTICIPATED.
AHEAD OF AN APPROACHING COLD FRONT...SMALL CRAFT ADVISORY GUSTS FROM
THE SOUTHWEST ARE POSSIBLE MONDAY AND MONDAY EVENING...ESPECIALLY
ACROSS NEARSHORE WATERS. HOWEVER...SINCE THIS EVENT APPEARS
MARGINAL...OPTED NOT TO RAISE A SMALL CRAFT ADVISORY.
IN THE WAKE OF COLD FROPA...WINDS WILL SHIFT TOWARD THE NORTHWEST.
TUESDAY THROUGH FRIDAY LOOK FAIRLY QUIET OVER THE WATERS AS HIGH
PRESSURE PREVAILS.
&&
.TIDES/COASTAL FLOODING...
THERE IS A CHANCE THAT THE HIGH TIDE COULD REACH OR SLIGHTLY
EXCEED 7.0 FT MLLW ON CHARLESTON HARBOR THIS EVENING.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...BSH
SHORT TERM...SPR
LONG TERM...JRL
AVIATION...BSH/SPR
MARINE...BSH/SPR
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
147 PM EDT SUN APR 19 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT INTO THE AREA TODAY...ACCOMPANIED BY AN UPPER
LEVEL DISTURBANCE. A COLD FRONT WILL APPROACH THE AREA MONDAY...
MOVING OFFSHORE MONDAY NIGHT. HIGH PRESSURE WILL BUILD IN TUESDAY
THROUGH THURSDAY. A WEAK COLD FRONT WILL DROP THROUGH THE AREA
THURSDAY NIGHT...THEN A STORM SYSTEM WILL AFFECT THE REGION NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY THIS AFTERNOON...QUICK UPDATE TO INCLUDE TORNADO WATCH 79
WHICH IS IN EFFECT THROUGH 8 PM. NO CHANGE TO PREVIOUS FORECAST
THINKING AND PREVIOUS DISCUSSION FOLLOWS BELOW.
LATE THIS MORNING...THE WARM FRONT PRECIPITATION THAT HAD
BLOSSOMED EARLIER THIS MORNING ACROSS SOUTHEAST GEORGIA HAS
DISSIPATED PRETTY RAPIDLY AS IT LIFTS TO THE NORTHEAST. AS
SUCH...THE REST OF THE MORNING WILL BE RELATIVELY QUIET AHEAD OF
THE MAIN FORECAST PROBLEM WHICH IS THE LARGE AREA OF CONVECTION
CURRENTLY IMPACTING MUCH OF ALABAMA/GEORGIA/FLORIDA.
OVERALL...THERE WILL BE LIMITED PRECIPITATION COVERAGE OUT AHEAD
OF THE APPROACHING LINE OTHER THAN SCATTERED DISCRETE
SHOWERS/THUNDERSTORMS THAT SHOULD DEVELOP RIGHT AS THE LINE PUSHES
INTO THE WESTERN ZONES. CURRENTLY...THE RECENT RUNS OF THE HRRR
SEEMS TO HAVE AN EXCELLENT HANDLE ON THE POSITION OF THE
CONVECTION AND ITS AFTERNOON PROGRESSION SEEMS QUITE REASONABLE.
REGARDING TIMING...THE HRRR IS RUNNING ABOUT AN HOUR OR TWO ON
THE SLOW SIDE SO WE THINK THE LINE OF STORMS WILL BEGIN IMPACTING
THE WESTERN ZONES IN THE 1-2PM WINDOW. THIS WOULD PUT THE LINE
INTO THE SAVANNAH METRO AREA 3-5PM AND THEN THE CHARLESTON REGION
BETWEEN 6-8PM. THE POTENTIAL FOR SEVERE WEATHER APPEARS TO BE
INCREASING. UPSTREAM OFFICES HAVE BEEN ISSUING A MIXTURE OF
SEVERE/TORNADO WARNINGS THIS MORNING WITH A NUMBER OF WIND DAMAGE
REPORTS. BASED ON ITS LOCATION RELATIVE TO THE LINE AT 12Z...THE
TAE MORNING SOUNDING IS LIKELY THE BEST SAMPLING OF THE
APPROACHING NEAR STORM ENVIRONMENT. AS SUCH...WE EXPECT A STRONGLY
SHEARED ENVIRONMENT WITH A NICE VEERING OF THE LOW LEVEL PROFILE
AND CAPE VALUES INCREASING INTO THE 1500-2000 J/KG RANGE. IN
FACT...THE TAE SOUNDING HAS A DISTINCT ELEVATED MIXED LAYER THAT
ACTUALLY SHOWS UP WELL WHEN LOOKING AT HRRR SOUNDINGS LATER THIS
AFTERNOON. ONE OF THE MORE TROUBLING ASPECTS IS THE POTENTIAL FOR
A WINDOW OF CLEARING NOTED ON VISIBLE SATELLITE IMAGERY. AS THIS
CLEARING HAS MOVED ACROSS SOUTH GEORGIA TEMPERATURES HAVE RISEN
INTO THE UPPER 70S AND EVEN TO 80 WITHIN JUST AN HOUR. GIVEN LOW
LEVEL THICKNESS VALUES AS THEY ARE...EVEN A BRIEF PERIOD OF SUN
WILL LEAD TO A RAPID WARM UP AND INCREASE THE SURFACE
DESTABILIZATION POTENTIAL.
SO USING THE HRRR AND ITS SOUNDINGS AS THE BEST REPRESENTATION OF
THE AFTERNOON NEAR STORM ENVIRONMENT...IT APPEARS WE ARE LOOKING
AT CAPE VALUES AS HIGH AS 2500 J/KG...0-3 KM SHEAR OF 30-35
KT...AND SRH VALUES BETWEEN 150-250 THANKS TO THE SOUTHEAST
BACKED LOW LEVEL FLOW. SUCH AN ENVIRONMENT WILL LIKELY FAVOR A
CONVECTIVE MODE OF LINEAR SEGMENTS WITH EMBEDDED SUPERCELL
ELEMENTS AND EVEN THE POTENTIAL FOR A DISCRETE SUPERCELL OR TWO.
DAMAGING WIND GUSTS CONTINUES TO BE THE PRIMARY SEVERE WEATHER
THREAT...BUT THE SHEAR AND LOW LEVEL VEERING WILL ALSO PROVIDE A
TORNADO THREAT AS WELL. MUCH WILL BE DETERMINED BY HOW MUCH SUN
CAN BREAK THROUGH AND TEMPERATURES WARM. ONE OTHER POTENTIAL THING
TO WATCH IS THAT THE CURRENT SOUTHEAST WINDS COULD ADVECT IN A
SLIGHTLY MORE STABLE MARINE ENVIRONMENT. HOWEVER...GIVEN THAT WE
ARE OUT OF THE COOLEST SHELF WATER SEASON THIS IMPACT IS EXPECTED
TO BE LIMITED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
TONIGHT...THE SHORTWAVE WILL PUSH OFF THE COAST AND ELEVATED POPS
DURING THE EVENING HOURS SHOULD DECREASE BELOW 15 PERCENT AS
SOMEWHAT DRIER AIR AND TEMPORARY SUBSIDENCE DEVELOP OVERNIGHT INTO
EARLY MONDAY. ANOTHER IN A SERIES OF VERY MILD OVERNIGHTS WITH
TEMPS ONLY FALLING TO THE MID 60S ONCE AGAIN.
THE LONGWAVE TROUGH WILL PERSIST TO OUR WEST ON MONDAY WHILE A
SERIES OF POTENT SHORTWAVES LIFT NORTHEAST THROUGH THE LOCAL
FORECAST AREA. A 145 KT SOUTHERN STREAM JET STREAK IS PROGGED TO
SLIDE ALONG THE CENTRAL GULF COAST REGION DURING THE DAY...SPREADING
A REGION OF ENHANCED UPPER LEVEL DIVERGENCE INTO SC/GA IN THE AFTERNOON.
MODEL TIME SECTIONS SHOW CONSIDERABLE DRYING ABOVE 850 MB EARLY IN
THE PERIOD...WITH PWATS DROPPING BELOW 1.25" BY MONDAY AFTERNOON.
THE MAIN COLD FRONT WILL SLOWLY MOVE EAST DURING THE DAY...CROSSING
THE REGION AT SOME POINT MONDAY EVENING. GIVEN THE DRY AIR ALOFT...
CONSIDERABLE BREAKS IN THE CLOUDS AND COMPRESSIONAL HEATING AHEAD
OF THE FRONT SHOULD HELP PUSH TEMPS INTO THE MID/UPPER 80S.
THE BIG QUESTION ON MONDAY IS HOW MUCH CONVECTIVE COVERAGE DEVELOPS.
THE DEEP DRY LAYER ABOVE THE SURFACE MAY LIMIT THE INITIAL
CONVECTIVE DEVELOPMENT. HOWEVER...MODELS ARE HINTING AT AN UPSTREAM
CONVECTIVE CLUSTER MOVING INTO WESTERN AREAS LATER IN THE AFTERNOON.
THERMODYNAMICS AND KINEMATICS ARE QUITE IMPRESSIVE ON MONDAY. 40-50
KT OF 0-6 KM BULK SHEAR...CAPES OF 1500-2000 J/KG AND DOWNDRAFT
CAPES 1000 TO 1500 J/KG. A FAIRLY ROBUST SEA BREEZE IS EXPECTED TO
DEVELOP IN THE AFTERNOON GIVEN SUCH WARM TEMPS INLAND AND PREVAILING
SOUTHERLY FLOW. THIS MAY COME INTO PLAY LATE IN THE DAY IF UPSTREAM
CONVECTION MOVES IN FROM THE WEST.
GIVEN THE SOMEWHAT DRIER TREND IN THE LATEST MODELS...WE MINIMIZED
POPS MONDAY MORNING WITH VALUES INCREASING TO 30-40% IN THE
AFTERNOON...ESPECIALLY ACROSS INTERIOR SC/GA. AS THE ACTIVITY AHEAD
OF THE FRONT MOVES THROUGH OUR AREA IT SHOULD BE GRADUALLY
WEAKENING. THEN SOME ADDITIONAL ACTIVITY...LIKELY WEAKER...COULD
ACCOMPANY THE ACTUAL FRONT LATER IN THE EVENING OR OVERNIGHT. WE
PLAN TO MAINTAIN SEVERE WEATHER POTENTIAL IN THE HAZARDOUS WEATHER
OUTLOOK.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT WITH DRY WEATHER AND
SEASONABLE TEMPERATURES TUESDAY AND WEDNESDAY. HIGHS WILL CLIMB TO
NEAR 80 BOTH DAYS WITH OVERNIGHT LOWS IN THE MID 50S.
&&
.LONG TERM /MONDAY THROUGH SUNDAY/...
A ZONAL PATTERN WILL EXIST MUCH OF THE PERIOD. A WEAK BACK DOOR COLD
FRONT DROPS THROUGH THE AREA THURSDAY NIGHT. THE FRONT WILL STALL TO
THE SOUTH BEFORE LIFTING BACK NORTH AS A WARM FRONT FRIDAY NIGHT AND
SATURDAY. A PRONOUNCED SHORTWAVE EMBEDDED IN THE QUASI-ZONAL FLOW
WILL MOVE THROUGH SATURDAY NIGHT ACCOMPANIED BY A COLD FRONT.
PRECIPITATION POSSIBLE STARTING FRIDAY NIGHT AND CONTINUING INTO
SATURDAY NIGHT. TEMPS WILL BE MODERATED BY INCREASING CLOUD COVER
AND WEAK COLD ADVECTION.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
MVFR CEILINGS HAVE RETURNED TO BOTH TERMINALS EARLY THIS AFTERNOON
AND THE MAIN FORECAST ISSUE THROUGH THE EVENING WILL BE TIMING
THUNDERSTORMS INTO THE FORECAST. BASED ON CURRENT RADAR TRENDS AND
HI-RES MODEL GUIDANCE...IT LOOKS LIKE THUNDER WILL REACH KSAV AND
IMPACT THE TERMINAL BETWEEN 20Z-22Z. HAVE GONE WITH IFR CONDITIONS
IN THUNDER WITH GUSTY WINDS TO ALMOST 40 KT BASED ON SOME UPSTREAM
OBSERVATIONS. AT KCHS...THUNDER WILL ARRIVE LATER AND IT IS
UNCLEAR IF IT WILL BE AS STRONG AS IT IS EXPECTED AT KSAV. HAVE
GONE WITH 22Z-00Z AT KCHS WITH IFR CONDITIONS AND SLIGHTLY LESSER
WIND GUSTS. ONCE THE CONVECTION MOVE EAST OF THE TERMINALS THERE
WILL BE A BIT OF A LULL UNTIL IFR CEILINGS ARE PROGGED TO RETURN
AFTER MIDNIGHT. BOTH SITES GET PREVAILING IFR CEILINGS THROUGH THE
LATE NIGHT...SCATTERING OUT MONDAY MORNING.
EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS/TSTMS EXPECTED AT BOTH
TERMINALS MONDAY AFTERNOON AND EVENING WITH BRIEF MVFR CEILING/VSBY
RESTRICTIONS POSSIBLE. OTHERWISE VFR CONDITIONS EXPECTED.
&&
.MARINE...
A WARM FRONT WILL LIFT THROUGH THE WATERS TODAY...FOLLOWED BY
INTENSIFYING SOUTH/SOUTHWEST FLOW. LIGHT AND VARIABLE WINDS EARLY
THIS MORNING WILL BECOME SE PRIOR TO THE WARM FRONT WHICH WILL
SHIFT FLOW SW TO S TONIGHT. WHILE SPEEDS INCREASE TONIGHT AND SEAS
SLOWLY BUILD...THE AVERAGE SPEED COULD REACH ONLY 15 KT BY
DAYBREAK OVER NEAR SHORE WATERS WITH SEAS 3 TO 4 FT.
THE POTENTIAL EXISTS FOR THUNDERSTORMS WITH STRONG WINDS OVER THE
WATERS THIS AFTERNOON EVENING. VERY HEAVY DOWNPOURS REDUCING
LOCAL VSBYS BELOW 1 NM ARE ALSO POSSIBLE WITH THE STRONGEST
STORMS MOVING OFFSHORE LATE IN THE DAY AND EARLY THIS EVENING.
A PREVAILING SSW FLOW WILL EXIST MONDAY MORNING AS A COLD FRONT
APPROACHES FROM THE WEST. THE GRADIENT WILL STRENGTHEN DURING THE
AFTERNOON...ESPECIALLY ALONG THE COAST WHERE A STRONG SEA BREEZE
DEVELOPS DUE TO MID/UPPER 80S TEMPS OVER LAND. THE LATEST GFS AND
NAM MOS AT FOLLY BEACH SC SHOW SFC WINDS EXCEEDING 20 KT LATE MONDAY
AFTERNOON WHEN THE SEA BREEZE IS STRONGEST. THIS SEEMS FAIRLY
REASONABLE GIVEN THE PATTERN AND THE WARMER INLAND TEMPS EXPECTED. A
SMALL CRAFT ADVISORY MAY EVENTUALLY BE REQUIRED FOR CHARLESTON
HARBOR MONDAY AFTERNOON FOR WINDS/GUSTS IN THE 20-30 KT RANGE.
A BRIEF PERIOD OF SMALL CRAFT ADVISORY CONDITIONS MAY DEVELOP OVER
OFFSHORE WATERS MONDAY NIGHT AS THE COLD FRONT MOVES THROUGH AND
WINDS GUST TO 25 KT WITH SOME 6 FT SEAS ALSO POSSIBLE.
TUESDAY THROUGH FRIDAY LOOK FAIRLY QUIET OVER THE WATERS AS HIGH
PRESSURE PREVAILS.
&&
.TIDES/COASTAL FLOODING...
THERE IS A CHANCE THAT THE HIGH TIDE COULD REACH OR SLIGHTLY
EXCEED 7.0 FT MLLW ON CHARLESTON HARBOR THIS EVENING.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...BSH
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...BSH
MARINE...JRL
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
508 PM CDT SUN APR 19 2015
.SHORT TERM...
319 PM CDT
THROUGH MONDAY NIGHT...
AFTER ANOTHER WARM EARLY AFTERNOON ACROSS MUCH OF THE REGION RAIN IS
BEGINNING TO SPREAD NORTHWARD ACROSS SOUTHERN SECTIONS OF THE CHICAGO
METRO AREA AS OF THIS WRITING. THIS ACTIVITY WILL CONTINUE TO
OVERSPREAD THE REGION THROUGH THE AFTERNOON AND EVENING...WITH
TEMPERATURES LIKELY TO DROP BACK INTO THE UPPER 50S AND LOW 60S IN
THE RAIN.
THE MID-LEVEL DISTURBANCE...AND THE ASSOCIATED SURFACE SYSTEM WILL
QUICKLY SHIFT NORTHWARD OVER LOWER MICHIGAN OVERNIGHT...AND IT
APPEARS THAT THE RAIN WILL BECOME MORE SHOWERY AND INTERMITTENT OR
POSSIBLY JUST SOME DRIZZLE LATER THIS EVENING AND INTO THE EARLY
MORNING ACROSS MUCH OF THE AREA AS THIS INITIAL MID LEVEL
DISTURBANCE SHIFTS NORTH OF THE AREA AND SOME DRIER MID LEVEL AIR
SHIFTS OVER THE SOUTHEASTERN HALF OF MY AREA. SOME ADDITIONAL RAIN
SHOWERS ARE POSSIBLE AGAIN EARLY MONDAY WITHIN A REGION OF MID LEVEL
DEFORMATION AND RAP AROUND MOISTURE ASSOCIATED WITH THE DEEPENING
LOWER AND MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION AND
SOUTHERN CANADA.
CONDITIONS SHOULD DRY OUT MONDAY AFTERNOON...WITH ONLY A SMALL
CHANCE OF AN ADDITIONAL SHOWER DEVELOPING AS COLDER AIR ALOFT
STEEPENS THE LOWER LEVEL LAPSE RATES. THE MAIN STORY DURING THE
AFTERNOON WILL BE THE WINDS. WINDS ARE EXPECTED TO INCREASE OUT OF
THE WEST-NORTHWEST DURING THE DAY AS STOUT SURFACE PRESSURE
GRADIENT SETS UP OVER THE REGION AS THE SURFACE LOW DEEPENS TO
AROUND 985 MB ACROSS ONTARIO MONDAY AFTERNOON. MODEL SOUNDINGS
SUGGEST GOOD AFTERNOON MIXING TO AROUND 850 MB SHOULD ALLOW FOR
GUSTS OF AROUND 30 KT AT TIMES...ESPECIALLY DURING THE AFTERNOON.
THESE WIND GUSTS SHOULD ABATE MONDAY EVENING...BUT STRONG WINDS
LOOK TO DEVELOP AGAIN ON TUESDAY. SEE LONG TERM DISCUSSION FOR
MORE INFO ON TUESDAY`S WINDS.
KJB
&&
.LONG TERM...
319 PM CDT
TUESDAY THROUGH SUNDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH BELOW NORMAL TEMPS
THROUGH THE FORECAST.
LARGE UPPER LEVEL CENTER WILL BE CENTERED ACROSS THE REGION AT THE
START OF THE PERIOD...AND REMAIN SITUATED THROUGH MUCH OF THE WORK
WEEK AS IT SLOWLY MOVES EAST. SEVERAL VORT LOBES ARE ANTICIPATED TO
WRAP AROUND THIS UPPER LEVEL LOW ON TUESDAY AND WITH STEEPENING
LAPSE RATES...EXPECT SKY COVER TO INCREASE THROUGH THE DAY WHILE
SCATTERED SHOWERS BECOME POSSIBLE...ESPECIALLY ACROSS NORTHERN
ILLINOIS. AS THIS OCCURS...LIKELY DEEP MIXING WITH STRONG FLOW ALOFT
WILL ALLOW FOR ANOTHER WINDY DAY. GUIDANCE IS SUGGESTING THAT
ADVISORY CONDITIONS COULD BE REACHED IN THE AFTERNOON...AND WILL
NEED TO CONTINUE MONITORING THIS POTENTIAL. ANY REMAINING PRECIP AND
CLOUD COVER SHOULD EXIT THE AREA TUESDAY NIGHT WITH DRY CONDITIONS
EXPECTED. SOME GUIDANCE DEVELOPS A SWATH OF PRECIP OVER THE CWA LATE
IN THE NIGHT INTO EARLY WEDNESDAY. HOWEVER...A MORE LIKELY SCENARIO
AT THIS TIME WOULD BE FOR DRY CONDITIONS AND SO HAVE LEFT OUT ANY
POPS AT THIS TIME. ONGOING CAA WILL MAKE FOR CHILLY CONDITIONS
TUESDAY NIGHT...WITH LOW TEMPS IN THE 30S. IF PRECIP WERE TO OCCUR
DURING THIS PERIOD...THESE COLDER CONDITIONS COULD SUPPORT THE
POTENTIAL FOR AT LEAST A RAIN SNOW MIX ACROSS NORTHERN ILLINOIS.
EXPECT DRY CONDITIONS WITH BELOW NORMAL TEMPS THROUGH THE REST OF
THE FORECAST PERIOD...WITH FORECAST HIGHS IN THE 50S. COLD NIGHT
TIME LOWS IN THE 30S COULD BECOME AN ISSUE LATE IN THE WORK WEEK AS
HIGH PRESSURE IS ANTICIPATED TO MOVE OVERHEAD...WITH LIGHTER WINDS
AND THE COLD TEMPS POSSIBLY CREATING A SETUP FOR FROST.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* EAST TO NORTHEAST WINDS AROUND 10 KT THROUGH MID EVENING.
* LIGHT TO MODERATE RAIN THROUGH MID-EVENING THEN BECOMING MORE
SHOWERY.
* QUICKLY LOWERING CIGS THROUGH SUNDOWN THEN GRADUALLY LOWERING
THROUGH IFR CATEGORY...POSSIBLY EVEN TO LIFR BY 03Z.
* GRADUALLY LOWERING VISIBILITY THROUGH THIS EVENING WITH IFR
VISIBILITY LIKELY PREVAILING BY MID EVENING.
* ANOTHER ROUND OF -SHRA PROBABLE EARLY MONDAY MORNING.
* GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT MONDAY AFTN.
MTF/JEE
//DISCUSSION...UPDATED 18Z...
RAIN IS SLOWLY PUSHING NORTH AND IS JUST SOUTH OF I-80 AT THIS
TIME. MVFR AND LOWER CIGS ARE OVER CENTRAL AND SOUTHERN IL AND
INDIANA BUT ALSO PUSHING NORTH. ADJUSTED PRECIP AND CIG TIMING
BASED ON RADAR AND SATELLITE TRENDS. MVFR VSBY WILL BE TIED TO THE
HEAVIER RAIN SHOWERS...AND CIGS WILL LOWER TO MVFR LATE THIS AFTN
AND THEN TO IFR THIS EVENING. ALL GUIDANCE MEMBERS SHOW IFR CIGS
ACROSS THE TERMINALS.
WILL EITHER SEE SCATTERED SHOWERS OR A BREAK IN RAIN AFTER
MIDNIGHT TONIGHT WITH ANOTHER ROUND OF RAIN PUSHING WEST TO EAST
EARLY MONDAY MORNING.
EAST WINDS BCM NORTHEAST ARND 10 KT LATE THIS AFTN AND BACK TO NW
BY 03Z. WINDS CONTINUE TO BACK TO WEST BY EARLY MONDAY MORNING.
GUSTY WINDS FOLLOW THE BAND OF RAIN SHOWERS...WITH 20G30KT
EXPECTED BY MONDAY AFTERNOON. THINKING THE GUSTY WINDS AND DRIER
AIR WILL HELP CIGS LIFT LATE MONDAY MORNING AND AFTN...BUT HAVE
MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM-HIGH IN WINDS.
* HIGH IN RAIN TIMING.
* MEDIUM-HIGH IN IFR CIG TIMING AND MEDIUM IN VISIBILITY TIMING.
* HIGH IN IFR CIG DURATION. LOW-MEDIUM IN IFR VISIBILITY DURATION.
MTF/JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
324 PM CDT
AS A TROUGH OF LOW PRESSURE AND SECONDARY LOW PRESSURE CENTER
MOVE ACROSS THE GREAT LAKES REGION TONIGHT...WINDS WILL LIKELY BE
VARIABLE AT TIMES. THIS WILL ESPECIALLY BE THE CASE OVER THE
SOUTHERN HALF OF THE LAKE WHERE THE LOW PRESSURE SYSTEM IS
EXPECTED TO MOVE THROUGH. IN THE NEAR TERM...EAST NORTHEAST WINDS
WILL PREVAIL OVER THE LAKE WITH THE HIGHEST SPEEDS TO 30 KT
OCCURRING OVER THE NORTHERN HALF AND WHILE 15 TO 25 KT WINDS ARE
BEING OBSERVED OVER THE SOUTH...WITH SPEEDS EXPECTED TO SLIGHTLY
DIMINISH TONIGHT. AS THIS TROUGH/LOW EXIT TO THE EAST ON
MONDAY...STRONGER WESTERLY WINDS WILL DEVELOP. HIGHEST WINDS TO 30
KT WILL OCCUR ALONG THE NEARSHORE WATERS WHILE ONLY 15 TO 25 KT
ARE LIKELY OVER THE OPEN WATERS. A SIMILAR SETUP IS EXPECTED ON
TUESDAY BUT WITH SPEEDS SLIGHTLY HIGHER...AS TO 30 KT WILL LIKELY
PREVAIL FOR BOTH LOCATIONS AND WITH EVEN GALES POSSIBLE ALONG THE
NEARSHORE WATERS DURING THE DAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...11 AM MONDAY TO 9 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
325 PM CDT SUN APR 19 2015
.SHORT TERM...
319 PM CDT
THROUGH MONDAY NIGHT...
AFTER ANOTHER WARM EARLY AFTERNOON ACROSS MUCH OF THE REGION RAIN IS
BEGINNING TO SPREAD NORTHWARD ACROSS SOUTHERN SECTIONS OF THE CHICAGO
METRO AREA AS OF THIS WRITING. THIS ACTIVITY WILL CONTINUE TO
OVERSPREAD THE REGION THROUGH THE AFTERNOON AND EVENING...WITH
TEMPERATURES LIKELY TO DROP BACK INTO THE UPPER 50S AND LOW 60S IN
THE RAIN.
THE MID-LEVEL DISTURBANCE...AND THE ASSOCIATED SURFACE SYSTEM WILL
QUICKLY SHIFT NORTHWARD OVER LOWER MICHIGAN OVERNIGHT...AND IT
APPEARS THAT THE RAIN WILL BECOME MORE SHOWERY AND INTERMITTENT OR
POSSIBLY JUST SOME DRIZZLE LATER THIS EVENING AND INTO THE EARLY
MORNING ACROSS MUCH OF THE AREA AS THIS INITIAL MID LEVEL
DISTURBANCE SHIFTS NORTH OF THE AREA AND SOME DRIER MID LEVEL AIR
SHIFTS OVER THE SOUTHEASTERN HALF OF MY AREA. SOME ADDITIONAL RAIN
SHOWERS ARE POSSIBLE AGAIN EARLY MONDAY WITHIN A REGION OF MID LEVEL
DEFORMATION AND RAP AROUND MOISTURE ASSOCIATED WITH THE DEEPENING
LOWER AND MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION AND
SOUTHERN CANADA.
CONDITIONS SHOULD DRY OUT MONDAY AFTERNOON...WITH ONLY A SMALL
CHANCE OF AN ADDITIONAL SHOWER DEVELOPING AS COLDER AIR ALOFT
STEEPENS THE LOWER LEVEL LAPSE RATES. THE MAIN STORY DURING THE
AFTERNOON WILL BE THE WINDS. WINDS ARE EXPECTED TO INCREASE OUT OF
THE WEST-NORTHWEST DURING THE DAY AS STOUT SURFACE PRESSURE
GRADIENT SETS UP OVER THE REGION AS THE SURFACE LOW DEEPENS TO
AROUND 985 MB ACROSS ONTARIO MONDAY AFTERNOON. MODEL SOUNDINGS
SUGGEST GOOD AFTERNOON MIXING TO AROUND 850 MB SHOULD ALLOW FOR
GUSTS OF AROUND 30 KT AT TIMES...ESPECIALLY DURING THE AFTERNOON.
THESE WIND GUSTS SHOULD ABATE MONDAY EVENING...BUT STRONG WINDS
LOOK TO DEVELOP AGAIN ON TUESDAY. SEE LONG TERM DISCUSSION FOR
MORE INFO ON TUESDAY`S WINDS.
KJB
&&
.LONG TERM...
319 PM CDT
TUESDAY THROUGH SUNDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH BELOW NORMAL TEMPS
THROUGH THE FORECAST.
LARGE UPPER LEVEL CENTER WILL BE CENTERED ACROSS THE REGION AT THE
START OF THE PERIOD...AND REMAIN SITUATED THROUGH MUCH OF THE WORK
WEEK AS IT SLOWLY MOVES EAST. SEVERAL VORT LOBES ARE ANTICIPATED TO
WRAP AROUND THIS UPPER LEVEL LOW ON TUESDAY AND WITH STEEPENING
LAPSE RATES...EXPECT SKY COVER TO INCREASE THROUGH THE DAY WHILE
SCATTERED SHOWERS BECOME POSSIBLE...ESPECIALLY ACROSS NORTHERN
ILLINOIS. AS THIS OCCURS...LIKELY DEEP MIXING WITH STRONG FLOW ALOFT
WILL ALLOW FOR ANOTHER WINDY DAY. GUIDANCE IS SUGGESTING THAT
ADVISORY CONDITIONS COULD BE REACHED IN THE AFTERNOON...AND WILL
NEED TO CONTINUE MONITORING THIS POTENTIAL. ANY REMAINING PRECIP AND
CLOUD COVER SHOULD EXIT THE AREA TUESDAY NIGHT WITH DRY CONDITIONS
EXPECTED. SOME GUIDANCE DEVELOPS A SWATH OF PRECIP OVER THE CWA LATE
IN THE NIGHT INTO EARLY WEDNESDAY. HOWEVER...A MORE LIKELY SCENARIO
AT THIS TIME WOULD BE FOR DRY CONDITIONS AND SO HAVE LEFT OUT ANY
POPS AT THIS TIME. ONGOING CAA WILL MAKE FOR CHILLY CONDITIONS
TUESDAY NIGHT...WITH LOW TEMPS IN THE 30S. IF PRECIP WERE TO OCCUR
DURING THIS PERIOD...THESE COLDER CONDITIONS COULD SUPPORT THE
POTENTIAL FOR AT LEAST A RAIN SNOW MIX ACROSS NORTHERN ILLINOIS.
EXPECT DRY CONDITIONS WITH BELOW NORMAL TEMPS THROUGH THE REST OF
THE FORECAST PERIOD...WITH FORECAST HIGHS IN THE 50S. COLD NIGHT
TIME LOWS IN THE 30S COULD BECOME AN ISSUE LATE IN THE WORK WEEK AS
HIGH PRESSURE IS ANTICIPATED TO MOVE OVERHEAD...WITH LIGHTER WINDS
AND THE COLD TEMPS POSSIBLY CREATING A SETUP FOR FROST.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* EAST WINDS ARND 10 KT BCMG NORTH LESS THAN 10 KT THIS EVENING.
* RAIN MOVING IN OVER THE NEXT 1-2 HOURS WITH MVFR VSBY. COULD
HAVE PERIODS OF IFR VSBY WITH HEAVIEST SHOWERS.
* CIGS LOWER TO IFR LATE THIS AFTN THROUGH EARLY MONDAY MORNING.
* SCATTERED SHOWERS OVERNIGHT WITH ANOTHER ROUND OF -SHRA EARLY
MONDAY MORNING.
* GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT MONDAY AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
RAIN IS SLOWLY PUSHING NORTH AND IS JUST SOUTH OF I-80 AT THIS
TIME. MVFR AND LOWER CIGS ARE OVER CENTRAL AND SOUTHERN IL AND
INDIANA BUT ALSO PUSHING NORTH. ADJUSTED PRECIP AND CIG TIMING
BASED ON RADAR AND SATELLITE TRENDS. MVFR VSBY WILL BE TIED TO THE
HEAVIER RAIN SHOWERS...AND CIGS WILL LOWER TO MVFR LATE THIS AFTN
AND THEN TO IFR THIS EVENING. ALL GUIDANCE MEMBERS SHOW IFR CIGS
ACROSS THE TERMINALS.
WILL EITHER SEE SCATTERED SHOWERS OR A BREAK IN RAIN AFTER
MIDNIGHT TONIGHT WITH ANOTHER ROUND OF RAIN PUSHING WEST TO EAST
EARLY MONDAY MORNING.
EAST WINDS BCM NORTHEAST ARND 10 KT LATE THIS AFTN AND BACK TO NW
BY 03Z. WINDS CONTINUE TO BACK TO WEST BY EARLY MONDAY MORNING.
GUSTY WINDS FOLLOW THE BAND OF RAIN SHOWERS...WITH 20G30KT
EXPECTED BY MONDAY AFTERNOON. THINKING THE GUSTY WINDS AND DRIER
AIR WILL HELP CIGS LIFT LATE MONDAY MORNING AND AFTN...BUT HAVE
MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN RAIN SHOWERS THIS AFTERNOON AND EVENING.
* HIGH CONFIDENCE IN PERIODS OF MVFR VSBY...LOW CONFIDENCE IN
OCCURRENCE AND PERSISTENCE OF IFR VSBY.
* HIGH CONFIDENCE IN IFR CIGS...MEDIUM CONFIDENCE TIMING AND
PERSISTENCE.
* HIGH CONFIDENCE IN WIND TRENDS OVERNIGHT...MEDIUM CONFIDENCE IN
TIMING OF BACKING WINDS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST PARAMETERS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
324 PM CDT
AS A TROUGH OF LOW PRESSURE AND SECONDARY LOW PRESSURE CENTER
MOVE ACROSS THE GREAT LAKES REGION TONIGHT...WINDS WILL LIKELY BE
VARIABLE AT TIMES. THIS WILL ESPECIALLY BE THE CASE OVER THE
SOUTHERN HALF OF THE LAKE WHERE THE LOW PRESSURE SYSTEM IS
EXPECTED TO MOVE THROUGH. IN THE NEAR TERM...EAST NORTHEAST WINDS
WILL PREVAIL OVER THE LAKE WITH THE HIGHEST SPEEDS TO 30 KT
OCCURRING OVER THE NORTHERN HALF AND WHILE 15 TO 25 KT WINDS ARE
BEING OBSERVED OVER THE SOUTH...WITH SPEEDS EXPECTED TO SLIGHTLY
DIMINISH TONIGHT. AS THIS TROUGH/LOW EXIT TO THE EAST ON
MONDAY...STRONGER WESTERLY WINDS WILL DEVELOP. HIGHEST WINDS TO 30
KT WILL OCCUR ALONG THE NEARSHORE WATERS WHILE ONLY 15 TO 25 KT
ARE LIKELY OVER THE OPEN WATERS. A SIMILAR SETUP IS EXPECTED ON
TUESDAY BUT WITH SPEEDS SLIGHTLY HIGHER...AS TO 30 KT WILL LIKELY
PREVAIL FOR BOTH LOCATIONS AND WITH EVEN GALES POSSIBLE ALONG THE
NEARSHORE WATERS DURING THE DAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
320 PM CDT SUN APR 19 2015
.SHORT TERM...
319 PM CDT
THROUGH MONDAY NIGHT...
AFTER ANOTHER WARM EARLY AFTERNOON ACROSS MUCH OF THE REGION RAIN IS
BEGINNING TO SPREAD NORTHWARD ACROSS SOUTHERN SECTIONS OF THE CHICAGO
METRO AREA AS OF THIS WRITING. THIS ACTIVITY WILL CONTINUE TO
OVERSPREAD THE REGION THROUGH THE AFTERNOON AND EVENING...WITH
TEMPERATURES LIKELY TO DROP BACK INTO THE UPPER 50S AND LOW 60S IN
THE RAIN.
THE MID-LEVEL DISTURBANCE...AND THE ASSOCIATED SURFACE SYSTEM WILL
QUICKLY SHIFT NORTHWARD OVER LOWER MICHIGAN OVERNIGHT...AND IT
APPEARS THAT THE RAIN WILL BECOME MORE SHOWERY AND INTERMITTENT OR
POSSIBLY JUST SOME DRIZZLE LATER THIS EVENING AND INTO THE EARLY
MORNING ACROSS MUCH OF THE AREA AS THIS INITIAL MID LEVEL
DISTURBANCE SHIFTS NORTH OF THE AREA AND SOME DRIER MID LEVEL AIR
SHIFTS OVER THE SOUTHEASTERN HALF OF MY AREA. SOME ADDITIONAL RAIN
SHOWERS ARE POSSIBLE AGAIN EARLY MONDAY WITHIN A REGION OF MID LEVEL
DEFORMATION AND RAP AROUND MOISTURE ASSOCIATED WITH THE DEEPENING
LOWER AND MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION AND
SOUTHERN CANADA.
CONDITIONS SHOULD DRY OUT MONDAY AFTERNOON...WITH ONLY A SMALL
CHANCE OF AN ADDITIONAL SHOWER DEVELOPING AS COLDER AIR ALOFT
STEEPENS THE LOWER LEVEL LAPSE RATES. THE MAIN STORY DURING THE
AFTERNOON WILL BE THE WINDS. WINDS ARE EXPECTED TO INCREASE OUT OF
THE WEST-NORTHWEST DURING THE DAY AS STOUT SURFACE PRESSURE
GRADIENT SETS UP OVER THE REGION AS THE SURFACE LOW DEEPENS TO
AROUND 985 MB ACROSS ONTARIO MONDAY AFTERNOON. MODEL SOUNDINGS
SUGGEST GOOD AFTERNOON MIXING TO AROUND 850 MB SHOULD ALLOW FOR
GUSTS OF AROUND 30 KT AT TIMES...ESPECIALLY DURING THE AFTERNOON.
THESE WIND GUSTS SHOULD ABATE MONDAY EVENING...BUT STRONG WINDS
LOOK TO DEVELOP AGAIN ON TUESDAY. SEE LONG TERM DISCUSSION FOR
MORE INFO ON TUESDAY`S WINDS.
KJB
&&
.LONG TERM...
319 PM CDT
TUESDAY THROUGH SUNDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH BELOW NORMAL TEMPS
THROUGH THE FORECAST.
LARGE UPPER LEVEL CENTER WILL BE CENTERED ACROSS THE REGION AT THE
START OF THE PERIOD...AND REMAIN SITUATED THROUGH MUCH OF THE WORK
WEEK AS IT SLOWLY MOVES EAST. SEVERAL VORT LOBES ARE ANTICIPATED TO
WRAP AROUND THIS UPPER LEVEL LOW ON TUESDAY AND WITH STEEPENING
LAPSE RATES...EXPECT SKY COVER TO INCREASE THROUGH THE DAY WHILE
SCATTERED SHOWERS BECOME POSSIBLE...ESPECIALLY ACROSS NORTHERN
ILLINOIS. AS THIS OCCURS...LIKELY DEEP MIXING WITH STRONG FLOW ALOFT
WILL ALLOW FOR ANOTHER WINDY DAY. GUIDANCE IS SUGGESTING THAT
ADVISORY CONDITIONS COULD BE REACHED IN THE AFTERNOON...AND WILL
NEED TO CONTINUE MONITORING THIS POTENTIAL. ANY REMAINING PRECIP AND
CLOUD COVER SHOULD EXIT THE AREA TUESDAY NIGHT WITH DRY CONDITIONS
EXPECTED. SOME GUIDANCE DEVELOPS A SWATH OF PRECIP OVER THE CWA LATE
IN THE NIGHT INTO EARLY WEDNESDAY. HOWEVER...A MORE LIKELY SCENARIO
AT THIS TIME WOULD BE FOR DRY CONDITIONS AND SO HAVE LEFT OUT ANY
POPS AT THIS TIME. ONGOING CAA WILL MAKE FOR CHILLY CONDITIONS
TUESDAY NIGHT...WITH LOW TEMPS IN THE 30S. IF PRECIP WERE TO OCCUR
DURING THIS PERIOD...THESE COLDER CONDITIONS COULD SUPPORT THE
POTENTIAL FOR AT LEAST A RAIN SNOW MIX ACROSS NORTHERN ILLINOIS.
EXPECT DRY CONDITIONS WITH BELOW NORMAL TEMPS THROUGH THE REST OF
THE FORECAST PERIOD...WITH FORECAST HIGHS IN THE 50S. COLD NIGHT
TIME LOWS IN THE 30S COULD BECOME AN ISSUE LATE IN THE WORK WEEK AS
HIGH PRESSURE IS ANTICIPATED TO MOVE OVERHEAD...WITH LIGHTER WINDS
AND THE COLD TEMPS POSSIBLY CREATING A SETUP FOR FROST.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* EAST WINDS ARND 10 KT BCMG NORTH LESS THAN 10 KT THIS EVENING.
* RAIN MOVING IN OVER THE NEXT 1-2 HOURS WITH MVFR VSBY. COULD
HAVE PERIODS OF IFR VSBY WITH HEAVIEST SHOWERS.
* CIGS LOWER TO IFR LATE THIS AFTN THROUGH EARLY MONDAY MORNING.
* SCATTERED SHOWERS OVERNIGHT WITH ANOTHER ROUND OF -SHRA EARLY
MONDAY MORNING.
* GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT MONDAY AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
RAIN IS SLOWLY PUSHING NORTH AND IS JUST SOUTH OF I-80 AT THIS
TIME. MVFR AND LOWER CIGS ARE OVER CENTRAL AND SOUTHERN IL AND
INDIANA BUT ALSO PUSHING NORTH. ADJUSTED PRECIP AND CIG TIMING
BASED ON RADAR AND SATELLITE TRENDS. MVFR VSBY WILL BE TIED TO THE
HEAVIER RAIN SHOWERS...AND CIGS WILL LOWER TO MVFR LATE THIS AFTN
AND THEN TO IFR THIS EVENING. ALL GUIDANCE MEMBERS SHOW IFR CIGS
ACROSS THE TERMINALS.
WILL EITHER SEE SCATTERED SHOWERS OR A BREAK IN RAIN AFTER
MIDNIGHT TONIGHT WITH ANOTHER ROUND OF RAIN PUSHING WEST TO EAST
EARLY MONDAY MORNING.
EAST WINDS BCM NORTHEAST ARND 10 KT LATE THIS AFTN AND BACK TO NW
BY 03Z. WINDS CONTINUE TO BACK TO WEST BY EARLY MONDAY MORNING.
GUSTY WINDS FOLLOW THE BAND OF RAIN SHOWERS...WITH 20G30KT
EXPECTED BY MONDAY AFTERNOON. THINKING THE GUSTY WINDS AND DRIER
AIR WILL HELP CIGS LIFT LATE MONDAY MORNING AND AFTN...BUT HAVE
MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN RAIN SHOWERS THIS AFTERNOON AND EVENING.
* HIGH CONFIDENCE IN PERIODS OF MVFR VSBY...LOW CONFIDENCE IN
OCCURRENCE AND PERSISTENCE OF IFR VSBY.
* HIGH CONFIDENCE IN IFR CIGS...MEDIUM CONFIDENCE TIMING AND
PERSISTENCE.
* HIGH CONFIDENCE IN WIND TRENDS OVERNIGHT...MEDIUM CONFIDENCE IN
TIMING OF BACKING WINDS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST PARAMETERS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
248 PM CDT SUN APR 19 2015
.UPDATE...
952 AM CDT
I MADE SOME UPDATES TO THE FORECAST FOR TODAY TO RAISE
TEMPERATURES AND PUSH OFF THE TIMING OF THE RAIN CHANCES.
WATER VAPOR IMAGERY INDICATES OUR MID/UPPER LEVEL DISTURBANCE OF
INTEREST FOR LATER TODAY NOW LIFTING NORTHWARD ACROSS WESTERN
KENTUCKY. THIS FEATURE IS CURRENTLY SUPPORTING AN AREA OF
NORTHWARD MOVING SHOWERS ACROSS SOUTHERN PORTIONS OF ILLINOIS AND
INDIANA. THEREFORE...THIS AREA OF SHOWERS WILL GRADUALLY WORK
NORTHWARD ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA
DURING THE AFTERNOON. IT APPEARS THE THREAT FOR THUNDERSTORMS WILL
BE VERY LOW WITH THIS ACTIVITY...WITH TRENDS SUGGESTING NO
LIGHTNING STRIKES OVER THE PAST FEW HOURS...SO I HAVE REMOVED THE
MENTION OF SUCH THIS AFTERNOON. IN ADDITION...WITH THE SLOWER
ONSET OF PRECIP TODAY...IT APPEARS TEMPERATURES WILL BE ABLE TO
WARM TO NEAR 70 IN MOST AREAS AWAY FROM LAKE MICHIGAN...SO I
RAISED HIGH TEMPERATURES TODAY.
KJB
&&
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* EAST WINDS ARND 10 KT BCMG NORTH LESS THAN 10 KT THIS EVENING.
* RAIN MOVING IN OVER THE NEXT 1-2 HOURS WITH MVFR VSBY. COULD
HAVE PERIODS OF IFR VSBY WITH HEAVIEST SHOWERS.
* CIGS LOWER TO IFR LATE THIS AFTN THROUGH EARLY MONDAY MORNING.
* SCATTERED SHOWERS OVERNIGHT WITH ANOTHER ROUND OF -SHRA EARLY
MONDAY MORNING.
* GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT MONDAY AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
RAIN IS SLOWLY PUSHING NORTH AND IS JUST SOUTH OF I-80 AT THIS
TIME. MVFR AND LOWER CIGS ARE OVER CENTRAL AND SOUTHERN IL AND
INDIANA BUT ALSO PUSHING NORTH. ADJUSTED PRECIP AND CIG TIMING
BASED ON RADAR AND SATELLITE TRENDS. MVFR VSBY WILL BE TIED TO THE
HEAVIER RAIN SHOWERS...AND CIGS WILL LOWER TO MVFR LATE THIS AFTN
AND THEN TO IFR THIS EVENING. ALL GUIDANCE MEMBERS SHOW IFR CIGS
ACROSS THE TERMINALS.
WILL EITHER SEE SCATTERED SHOWERS OR A BREAK IN RAIN AFTER
MIDNIGHT TONIGHT WITH ANOTHER ROUND OF RAIN PUSHING WEST TO EAST
EARLY MONDAY MORNING.
EAST WINDS BCM NORTHEAST ARND 10 KT LATE THIS AFTN AND BACK TO NW
BY 03Z. WINDS CONTINUE TO BACK TO WEST BY EARLY MONDAY MORNING.
GUSTY WINDS FOLLOW THE BAND OF RAIN SHOWERS...WITH 20G30KT
EXPECTED BY MONDAY AFTERNOON. THINKING THE GUSTY WINDS AND DRIER
AIR WILL HELP CIGS LIFT LATE MONDAY MORNING AND AFTN...BUT HAVE
MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN RAIN SHOWERS THIS AFTERNOON AND EVENING.
* HIGH CONFIDENCE IN PERIODS OF MVFR VSBY...LOW CONFIDENCE IN
OCCURRENCE AND PERSISTENCE OF IFR VSBY.
* HIGH CONFIDENCE IN IFR CIGS...MEDIUM CONFIDENCE TIMING AND
PERSISTENCE.
* HIGH CONFIDENCE IN WIND TRENDS OVERNIGHT...MEDIUM CONFIDENCE IN
TIMING OF BACKING WINDS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST PARAMETERS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1237 PM CDT SUN APR 19 2015
.UPDATE...
952 AM CDT
I MADE SOME UPDATES TO THE FORECAST FOR TODAY TO RAISE
TEMPERATURES AND PUSH OFF THE TIMING OF THE RAIN CHANCES.
WATER VAPOR IMAGERY INDICATES OUR MID/UPPER LEVEL DISTURBANCE OF
INTEREST FOR LATER TODAY NOW LIFTING NORTHWARD ACROSS WESTERN
KENTUCKY. THIS FEATURE IS CURRENTLY SUPPORTING AN AREA OF
NORTHWARD MOVING SHOWERS ACROSS SOUTHERN PORTIONS OF ILLINOIS AND
INDIANA. THEREFORE...THIS AREA OF SHOWERS WILL GRADUALLY WORK
NORTHWARD ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA
DURING THE AFTERNOON. IT APPEARS THE THREAT FOR THUNDERSTORMS WILL
BE VERY LOW WITH THIS ACTIVITY...WITH TRENDS SUGGESTING NO
LIGHTNING STRIKES OVER THE PAST FEW HOURS...SO I HAVE REMOVED THE
MENTION OF SUCH THIS AFTERNOON. IN ADDITION...WITH THE SLOWER
ONSET OF PRECIP TODAY...IT APPEARS TEMPERATURES WILL BE ABLE TO
WARM TO NEAR 70 IN MOST AREAS AWAY FROM LAKE MICHIGAN...SO I
RAISED HIGH TEMPERATURES TODAY.
KJB
&&
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* EAST WINDS 10-14 KT BCMG NORTH LESS THAN 10 KT THIS EVENING.
* RAIN ARRIVES 21-22Z WITH 5SM VSBY WITH HEAVIER SHOWERS.
* CIGS LOWER TO MVFR LATE THIS AFTN THEN TO IFR THIS EVENING
THROUGH EARLY MONDAY MORNING.
* SCATTERED SHOWERS OVERNIGHT WITH ANOTHER ROUND OF -SHRA EARLY
MONDAY MORNING.
* GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT MONDAY AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
RAIN IS SLOWLY PUSHING NORTH AND IS JUST SOUTH OF I-80 AT THIS
TIME. MVFR AND LOWER CIGS ARE OVER CENTRAL AND SOUTHERN IL AND
INDIANA BUT ALSO PUSHING NORTH. ADJUSTED PRECIP AND CIG TIMING
BASED ON RADAR AND SATELLITE TRENDS. MVFR VSBY WILL BE TIED TO THE
HEAVIER RAIN SHOWERS...AND CIGS WILL LOWER TO MVFR LATE THIS AFTN
AND THEN TO IFR THIS EVENING. ALL GUIDANCE MEMBERS SHOW IFR CIGS
ACROSS THE TERMINALS.
WILL EITHER SEE SCATTERED SHOWERS OR A BREAK IN RAIN AFTER
MIDNIGHT TONIGHT WITH ANOTHER ROUND OF RAIN PUSHING WEST TO EAST
EARLY MONDAY MORNING.
EAST WINDS BCM NORTHEAST ARND 10 KT LATE THIS AFTN AND BACK TO NW
BY 03Z. WINDS CONTINUE TO BACK TO WEST BY EARLY MONDAY MORNING.
GUSTY WINDS FOLLOW THE BAND OF RAIN SHOWERS...WITH 20G30KT
EXPECTED BY MONDAY AFTERNOON. THINKING THE GUSTY WINDS AND DRIER
AIR WILL HELP CIGS LIFT LATE MONDAY MORNING AND AFTN...BUT HAVE
MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN RAIN SHOWERS THIS AFTERNOON AND EVENING.
* HIGH CONFIDENCE IN MVFR CIGS...MEDIUM CONFIDENCE IN MVFR CIG
TIMING AND OCCURRENCE AND TIMING OF IFR CIGS.
* HIGH CONFIDENCE IN WIND TRENDS OVERNIGHT...MEDIUM CONFIDENCE IN
TIMING OF BACKING WINDS.
* MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR MONDAY.
* HIGH CONFIDENCE IN ALL OTHER FORECAST PARAMETERS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1229 PM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 1114 AM CDT SUN APR 19 2015
SFC LOW LIFTING NORTHWARD INTO THE REGION AND PUSHING PLENTY OF
WAA RAIN AHEAD OF IT ACROSS THE FA. PLENTY OF PRECIP EXPECTED
TODAY AND INTO TONIGHT, BUT MORE SCATTERED IN NATURE IN THE
OVERNIGHT HOURS. SOME DRY AIR WORKING AROUND THE LOW AND ERODING
SOME OF THE RAINFALL MAY BRING A BREAK IN THE RAINFALL
BRIEFLY...BUT NOT ENOUGH TO PULL PRECIP ANYWHERE FOR LONG. HAVE
MADE A FEW ADJUSTMENTS TO THE FORECAST, BUT NO MAJOR UPDATES ARE
ANTICIPATED AT THIS TIME.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT SUN APR 19 2015
LATEST WATER VAPOR IMAGERY CONTINUES TO SHOW CLOSED UPPER LOW OVER
EASTERN COLORADO, WITH LEAD SHORT-WAVE ROTATING AROUND THIS FEATURE
ACROSS ARKANSAS/LOUISIANA. AS THIS WAVE LIFTS NORTHWARD, PRECIP
WILL EVENTUALLY SPREAD INTO CENTRAL ILLINOIS TODAY. 07Z/2AM RADAR
MOSAIC SHOWS DRY CONDITIONS ACROSS THE ENTIRE KILX CWA: HOWEVER,
SHOWERS ARE BEGINNING TO DEVELOP AND BECOME MORE WIDESPREAD FURTHER
SOUTH ACROSS WESTERN KENTUCKY AND FAR SOUTHERN ILLINOIS. BASED ON
RADAR TIMING TOOLS AND LATEST HRRR FORECAST, THINK SCATTERED SHOWERS
WILL ARRIVE SOUTH OF I-70 OVER THE NEXT COUPLE OF HOURS, THEN WILL
SPREAD NORTHWARD TOWARD THE I-74 CORRIDOR BY MIDDAY. HAVE ADJUSTED
POPS TO ACCOUNT FOR THE SLOWER ARRIVAL OF PRECIP DURING THE MORNING,
THEN HAVE GONE WITH CATEGORICAL POPS ACROSS THE BOARD THIS
AFTERNOON. ASIDE FROM SOME SBCAPES OF AROUND 1000J/KG ACROSS THE
FAR SE CWA, FORECAST SOUNDINGS REMAIN FAIRLY STABLE TODAY. AS A
RESULT, AM EXPECTING MAINLY SHOWERS WITH JUST A FEW EMBEDDED
THUNDERSTORMS. DUE TO CLOUD COVER AND PRECIP, HIGH TEMPERATURES
WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS, WITH READINGS
MAINLY IN THE 60S. WARMEST TEMPS OF AROUND 70 WILL BE FOCUSED
ALONG/WEST OF THE ILLINOIS RIVER WHERE PRECIP WILL BE SLOWEST TO
ARRIVE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 328 AM CDT SUN APR 19 2015
LEAD SHORT-WAVE WILL LIFT INTO NORTHERN ILLINOIS/INDIANA BY EARLY
EVENING, LIKELY LEADING TO A TEMPORARY LULL IN THE SHOWERS.
MEANWHILE, THE MAIN UPPER LOW WILL GET A SOLID PUSH EASTWARD AND
WILL ARRIVE ACROSS ILLINOIS LATER TONIGHT INTO MONDAY MORNING.
SHOWERS AND PERHAPS A THUNDERSTORM WILL ACCOMPANY THIS FEATURE, SO
WILL CONTINUE LIKELY POPS TONIGHT THROUGH MONDAY MORNING. ONCE THE
500MB VORT MAX AND THE ASSOCIATED SURFACE COLD FRONT PASS TO THE
EAST, RAIN CHANCES WILL COME TO AN END BY MONDAY AFTERNOON. THANKS
TO A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT, STRONG W/NW
WINDS GUSTING TO BETWEEN 25 AND 30 MPH WILL DEVELOP ON MONDAY. THE
WINDS WILL SUBSIDE FOR A TIME MONDAY NIGHT, BUT WILL ONCE AGAIN
INCREASE MARKEDLY DURING THE DAY TUESDAY. HIGH TEMPERATURES BOTH
DAYS WILL REMAIN IN THE LOWER 60S, WHILE OVERNIGHT LOWS DIP INTO THE
UPPER 30S AND LOWER 40S.
00Z APR 19 MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING
THE EXTENDED FORECAST, WITH CONSENSUS FEATURING A CHILLY AND LARGELY
DRY WEEK AHEAD. BOTH THE GFS AND ECMWF INDICATE A WEAK COLD FRONT
WILL PASS THROUGH CENTRAL ILLINOIS TUESDAY NIGHT INTO WEDNESDAY:
HOWEVER, THEY DISAGREE ON HOW MUCH PRECIP IT WILL GENERATE. THE GFS
IS SLIGHTLY WETTER AND FASTER WITH FROPA, WHILE THE ECMWF IS DRIER
AND ABOUT 6 HOURS SLOWER WITH THE FRONT. DUE TO THE STRONG
NORTHWESTERLY UPPER FLOW PATTERN IN PLACE ACROSS THE MIDWEST, THINK
THE FASTER GFS IS THE WAY TO GO WITH TIMING, BUT THINK THE DRIER
ECMWF IS BETTER WITH QPF AS DEEP MOISTURE WILL BE LACKING WITH THIS
FEATURE. AS A RESULT, HAVE OPTED TO CARRY LOW CHANCE POPS
EVERYWHERE TUESDAY NIGHT, THEN ONLY ACROSS THE SE CWA ON WEDNESDAY.
ONCE THE FRONT PASSES, A COOL/CANADIAN AIRMASS WILL SETTLE INTO THE
REGION FOR THE MIDDLE AND END OF THE WEEK. HIGH TEMPERATURES WILL
STRUGGLE TO REACH THE 60 DEGREE MARK ON BOTH WEDNESDAY AND THURSDAY,
WHILE LOWS DROP INTO THE 30S. COLDEST MORNING MAY END UP BEING
FRIDAY MORNING, WHEN RIDGE OF HIGH PRESSURE IS OVERHEAD AND WINDS
WILL BE LIGHTEST. WILL NEED TO KEEP AN EYE ON TEMPS, AS FROST
ADVISORIES WILL BE POSSIBLE ACROSS PARTS OF CENTRAL/SOUTHEAST
ILLINOIS LATER THIS WEEK. AFTER THAT, ANOTHER SYSTEM WILL APPROACH
FROM THE SOUTHWEST BY THE END OF THE WEEK: HOWEVER, ITS INFLUENCE
LIKELY WILL NOT BE FELT UNTIL FRIDAY NIGHT/SATURDAY AT THE EARLIEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1226 PM CDT SUN APR 19 2015
MODELS BRINGING THE SFC LOW UP AND THROUGH THE AREA WITHIN THE TAF
PD. TWO MAJOR CONCERNS...VIS DROP AND LOW CIGS ASSOCIATED WITH THE
PROLONGED RAIN. HAVE KEPT THE LOWER VIS/CIGS ON THE EASTERN
TERMINALS. CONCERN ON THE WEST SIDE IS THE MODEL HINT AT A
SECONDARY LINE OF PRECIP SHOWING UP WITH THE 500MB TROF LATER AS
THE LOW PULLS OUT TO THE EAST. GUIDANCE NOT REALLY REFLECTING THAT
WELL...AND WILL BE IN CONFLICT WITH SOME OF THE DRIER AIR BEING
PULLED INTO THE WEST SIDE OF THE SYSTEM. CONFIDENCE LOWER FOR PIA
AND SPI THAN THE OTHER SITES.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1119 AM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 1114 AM CDT SUN APR 19 2015
SFC LOW LIFTING NORTHWARD INTO THE REGION AND PUSHING PLENTY OF
WAA RAIN AHEAD OF IT ACROSS THE FA. PLENTY OF PRECIP EXPECTED
TODAY AND INTO TONIGHT, BUT MORE SCATTERED IN NATURE IN THE
OVERNIGHT HOURS. SOME DRY AIR WORKING AROUND THE LOW AND ERODING
SOME OF THE RAINFALL MAY BRING A BREAK IN THE RAINFALL
BRIEFLY...BUT NOT ENOUGH TO PULL PRECIP ANYWHERE FOR LONG. HAVE
MADE A FEW ADJUSTMENTS TO THE FORECAST, BUT NO MAJOR UPDATES ARE
ANTICIPATED AT THIS TIME.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT SUN APR 19 2015
LATEST WATER VAPOR IMAGERY CONTINUES TO SHOW CLOSED UPPER LOW OVER
EASTERN COLORADO, WITH LEAD SHORT-WAVE ROTATING AROUND THIS FEATURE
ACROSS ARKANSAS/LOUISIANA. AS THIS WAVE LIFTS NORTHWARD, PRECIP
WILL EVENTUALLY SPREAD INTO CENTRAL ILLINOIS TODAY. 07Z/2AM RADAR
MOSAIC SHOWS DRY CONDITIONS ACROSS THE ENTIRE KILX CWA: HOWEVER,
SHOWERS ARE BEGINNING TO DEVELOP AND BECOME MORE WIDESPREAD FURTHER
SOUTH ACROSS WESTERN KENTUCKY AND FAR SOUTHERN ILLINOIS. BASED ON
RADAR TIMING TOOLS AND LATEST HRRR FORECAST, THINK SCATTERED SHOWERS
WILL ARRIVE SOUTH OF I-70 OVER THE NEXT COUPLE OF HOURS, THEN WILL
SPREAD NORTHWARD TOWARD THE I-74 CORRIDOR BY MIDDAY. HAVE ADJUSTED
POPS TO ACCOUNT FOR THE SLOWER ARRIVAL OF PRECIP DURING THE MORNING,
THEN HAVE GONE WITH CATEGORICAL POPS ACROSS THE BOARD THIS
AFTERNOON. ASIDE FROM SOME SBCAPES OF AROUND 1000J/KG ACROSS THE
FAR SE CWA, FORECAST SOUNDINGS REMAIN FAIRLY STABLE TODAY. AS A
RESULT, AM EXPECTING MAINLY SHOWERS WITH JUST A FEW EMBEDDED
THUNDERSTORMS. DUE TO CLOUD COVER AND PRECIP, HIGH TEMPERATURES
WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS, WITH READINGS
MAINLY IN THE 60S. WARMEST TEMPS OF AROUND 70 WILL BE FOCUSED
ALONG/WEST OF THE ILLINOIS RIVER WHERE PRECIP WILL BE SLOWEST TO
ARRIVE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 328 AM CDT SUN APR 19 2015
LEAD SHORT-WAVE WILL LIFT INTO NORTHERN ILLINOIS/INDIANA BY EARLY
EVENING, LIKELY LEADING TO A TEMPORARY LULL IN THE SHOWERS.
MEANWHILE, THE MAIN UPPER LOW WILL GET A SOLID PUSH EASTWARD AND
WILL ARRIVE ACROSS ILLINOIS LATER TONIGHT INTO MONDAY MORNING.
SHOWERS AND PERHAPS A THUNDERSTORM WILL ACCOMPANY THIS FEATURE, SO
WILL CONTINUE LIKELY POPS TONIGHT THROUGH MONDAY MORNING. ONCE THE
500MB VORT MAX AND THE ASSOCIATED SURFACE COLD FRONT PASS TO THE
EAST, RAIN CHANCES WILL COME TO AN END BY MONDAY AFTERNOON. THANKS
TO A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT, STRONG W/NW
WINDS GUSTING TO BETWEEN 25 AND 30 MPH WILL DEVELOP ON MONDAY. THE
WINDS WILL SUBSIDE FOR A TIME MONDAY NIGHT, BUT WILL ONCE AGAIN
INCREASE MARKEDLY DURING THE DAY TUESDAY. HIGH TEMPERATURES BOTH
DAYS WILL REMAIN IN THE LOWER 60S, WHILE OVERNIGHT LOWS DIP INTO THE
UPPER 30S AND LOWER 40S.
00Z APR 19 MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING
THE EXTENDED FORECAST, WITH CONSENSUS FEATURING A CHILLY AND LARGELY
DRY WEEK AHEAD. BOTH THE GFS AND ECMWF INDICATE A WEAK COLD FRONT
WILL PASS THROUGH CENTRAL ILLINOIS TUESDAY NIGHT INTO WEDNESDAY:
HOWEVER, THEY DISAGREE ON HOW MUCH PRECIP IT WILL GENERATE. THE GFS
IS SLIGHTLY WETTER AND FASTER WITH FROPA, WHILE THE ECMWF IS DRIER
AND ABOUT 6 HOURS SLOWER WITH THE FRONT. DUE TO THE STRONG
NORTHWESTERLY UPPER FLOW PATTERN IN PLACE ACROSS THE MIDWEST, THINK
THE FASTER GFS IS THE WAY TO GO WITH TIMING, BUT THINK THE DRIER
ECMWF IS BETTER WITH QPF AS DEEP MOISTURE WILL BE LACKING WITH THIS
FEATURE. AS A RESULT, HAVE OPTED TO CARRY LOW CHANCE POPS
EVERYWHERE TUESDAY NIGHT, THEN ONLY ACROSS THE SE CWA ON WEDNESDAY.
ONCE THE FRONT PASSES, A COOL/CANADIAN AIRMASS WILL SETTLE INTO THE
REGION FOR THE MIDDLE AND END OF THE WEEK. HIGH TEMPERATURES WILL
STRUGGLE TO REACH THE 60 DEGREE MARK ON BOTH WEDNESDAY AND THURSDAY,
WHILE LOWS DROP INTO THE 30S. COLDEST MORNING MAY END UP BEING
FRIDAY MORNING, WHEN RIDGE OF HIGH PRESSURE IS OVERHEAD AND WINDS
WILL BE LIGHTEST. WILL NEED TO KEEP AN EYE ON TEMPS, AS FROST
ADVISORIES WILL BE POSSIBLE ACROSS PARTS OF CENTRAL/SOUTHEAST
ILLINOIS LATER THIS WEEK. AFTER THAT, ANOTHER SYSTEM WILL APPROACH
FROM THE SOUTHWEST BY THE END OF THE WEEK: HOWEVER, ITS INFLUENCE
LIKELY WILL NOT BE FELT UNTIL FRIDAY NIGHT/SATURDAY AT THE EARLIEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 542 AM CDT SUN APR 19 2015
MID AND HIGH CLOUDS WILL CONTINUE OVER THE AREA THIS MORNING,
EFFECTING ALL TAF SITES UNTIL THE PCPN MOVES INTO THE SITES. WILL
START ALL SITES WITH VCSH AS THE PCPN MOVES NORTHWARD AND
INITIALLY SATURATES THE LOWER LEVELS, DURING THE MORNING HOURS.
THEN BETWEEN 10AM AND NOON, PCPN WILL BECOME MORE DOMINATE AND
STEADY. TIMING OF ONSET OF PCPN WAS TAKEN FROM A BLEND OF THE
BUFKIT DATA, NAM12, HRRR, AND RADAR TRENDS. MVFR CIGS AND VIS
WILL ARRIVE WITH THE RAIN AND CONTINUE THROUGH REST OF TAF VALID
PERIOD. PCPN COULD LET UP SOME LATE THIS EVENING, SO HAVE ADDED
ANOTHER LINE FOR VCSH AFTER THE BULK OF THE RAIN MOVES THROUGH,
AND BEFORE THE NEXT BATCH ARRIVES LATE TONIGHT/EARLY TOMORROW
MORNING. WINDS WILL BE EASTERLY TO START, BUT THEN BECOME
SOUTHEASTERLY AS THE SYSTEM GET CLOSER TO THE SITES. WITH THE
SURFACE LOW PRESSURE AREA MOVING RIGHT OVER THE TAFS, WINDS WILL
BE VARIABLE, ENDING AT WEST TO SOUTHWEST LATER TONIGHT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1110 AM CDT SUN APR 19 2015
.UPDATE...
952 AM CDT
I MADE SOME UPDATES TO THE FORECAST FOR TODAY TO RAISE
TEMPERATURES AND PUSH OFF THE TIMING OF THE RAIN CHANCES.
WATER VAPOR IMAGERY INDICATES OUR MID/UPPER LEVEL DISTURBANCE OF
INTEREST FOR LATER TODAY NOW LIFTING NORTHWARD ACROSS WESTERN
KENTUCKY. THIS FEATURE IS CURRENTLY SUPPORTING AN AREA OF
NORTHWARD MOVING SHOWERS ACROSS SOUTHERN PORTIONS OF ILLINOIS AND
INDIANA. THEREFORE...THIS AREA OF SHOWERS WILL GRADUALLY WORK
NORTHWARD ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA
DURING THE AFTERNOON. IT APPEARS THE THREAT FOR THUNDERSTORMS WILL
BE VERY LOW WITH THIS ACTIVITY...WITH TRENDS SUGGESTING NO
LIGHTNING STRIKES OVER THE PAST FEW HOURS...SO I HAVE REMOVED THE
MENTION OF SUCH THIS AFTERNOON. IN ADDITION...WITH THE SLOWER
ONSET OF PRECIP TODAY...IT APPEARS TEMPERATURES WILL BE ABLE TO
WARM TO NEAR 70 IN MOST AREAS AWAY FROM LAKE MICHIGAN...SO I
RAISED HIGH TEMPERATURES TODAY.
KJB
&&
.SHORT TERM...
340 AM CDT
THROUGH MONDAY...
UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW
PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE
ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND
THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING
INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS
WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN
PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE
SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND
NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS
LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE
PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH
DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40
SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER
40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO
DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER
THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM
WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF
LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS
OCCURRING.
LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION
NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT
REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA.
A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS
FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN
FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL
SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER.
THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF
THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE
NORTHERN STREAM SHORTWAVE.
OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE
SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW
LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE
CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED
WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF
SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE
HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET
WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY
LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH
THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS
AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN
THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL
ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO
SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE
EXISTS IN COVERAGE FARTHER EAST.
THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE
MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO
VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN
MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT
SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME.
THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE
NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING
ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY
AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY
IN THE COLD ADVECTION REGIME.
KMD
&&
.LONG TERM...
340 AM CDT
MONDAY NIGHT THROUGH SATURDAY...
THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A
HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL
RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY
HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR
NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO.
THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING
OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED
STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH
BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS
AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD
NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE
HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND
LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS
IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO
IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME
THOUGH...SO RECORD COLD IS NOT ANTICIPATED.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* EAST WINDS BETWEEN 10-15KT INTO THIS EVENING.
* WEST WINDS GUSTING TO 20 KT TOMORROW.
* RAIN OVERSPREADS TAF SITES LATER THIS AFTN THRU TONIGHT. MVFR
VSBY UNDER HEAVIER SHOWERS.
* LOW END MVFR CIGS DEVELOP...POSSIBLY IFR CONDS DEVELOP BY 3Z
THRU DAYBREAK MON.
* A SECOND ROUND OF RAIN ARRIVES EARLY MONDAY MORNING.
JEE
//DISCUSSION...UPDATED 12Z...
EAST WINDS CONTINUE TO KEEP THE LOW LEVELS RELATIVELY DRY AND LACK
OF LOW CLOUDS...HOWEVER MOISTURE IS CREEPING NORTH ACROSS SOUTHERN
IL/IN. WINDS WILL OCCASIONALLY GUST TO 20KT THRU MIDDAY...THEN
EXPECT WITH THE ABUNDANCE OF MOISTURE AND RAIN THE GUSTS MAY
BECOME LESS FREQUENT WITH SUSTAINED WINDS INCREASING SLIGHTLY TO
ARND 12-15KT. AS A LOW PRESSURE LIFTS NORTHEAST TOWARDS THE REGION
TONIGHT...CIGS ARE EXPECTED TO LOWER TO MVFR AND LIKELY TO IFR
CONDS WITH BASES ARND 800FT AGL BY 3Z. A FEW GUIDANCE MEMBERS
SUGGEST CIGS MAY DIP FURTHER TO ARND 400FT AGL BY 6Z AS A BRIEF
LULL IN THE PRECIP IS POISED TO LIFT OVERHEAD. AT THIS TIME WILL
MENTION VCSH BY 6Z MON...WHICH MAY END UP AS DRIZZLE OR LGT RAIN.
CIGS WILL REMAIN IFR THRU DAYBREAK MON...UNTIL A TIGHT GRADIENT
RETURNS AND WINDS INCREASE FROM THE WEST/NORTHWEST. THIS SHUD HELP
TO LIFT CIGS BACK TO MVFR AND EVENTUALLY VFR CONDS BY LATER MON.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN RAIN TIMING...MEDIUM-HIGH CONFIDENCE IN
PRECIP COVERAGE THIS EVENING. MEDIUM CONFIDENCE IN PRECIP
COVERAGE TONIGHT AND MONDAY MORNING.
* MEDIUM CONFIDENCE IN WIND SPEED AND DIRECTION AFTER 18Z.
* HIGH CONFIDENCE IN CIGS BCMG AT LEAST MVFR AND PSBLY
IFR...MEDIUM CONFIDENCE IN TIMING.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR BECOMING VFR.
TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS.
WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
FRIDAY...MAINLY VFR. CHC PM SHRA.
SATURDAY...MAINLY VFR.
BEACHLER
&&
.MARINE...
257 AM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST
TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE
CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE
LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN
TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS
POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE
ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL
THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON.
THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL
DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT
GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER
TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID-
WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES
TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID-
WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
248 PM EDT SUN APR 19 2015
.SYNOPSIS...
SHOWERS WILL OVERSPREAD THE REGION THIS EVENING AND CONTINUE
THROUGH MONDAY. UNSEASONABLY COOL TEMPERATURES ARE EXPECTED FOR
THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
DRY AIR SAMPLED BY THE 12Z UPPER AIR SOUNDING REVEALS A
SUBSTANTIAL LAYER OF DRY AIR. THIS HAS KEPT THE RAIN AND CLOUDS AT
BAY FOR MUCH OF THE DAY...ALLOWING FOR TEMPERATURES TO RISE
QUICKLY ABOVE NORMAL. TEMPERATURE RISES HAVE BEEN AIDED...AT LEAST
IN PART...BY DOWNSLOPING EASTERLY FLOW SUSTAINED AT 10-15KTS WITH
GUSTS CLOSE TO 25KTS.
TEMPERATURES THIS EVENING WILL DECREASE ACROSS THE SOUTH FIRST AS
THE THICKER CLOUD COVER AND EVENTUAL RAIN SHOWERS MOVE IN. TIMING
THE ONSET OF PRECIPITATION HAS BEEN PUSHED BACK AN HOUR OR TWO FOR
MOST LOCATIONS TO ACCOUNT FOR THE DRY AIR IN PLACE. KEEPING
CATEGORICAL POPS IN FOR THIS EVENING/EARLY TONIGHT...DESPITE
SEVERAL OF THE LATEST HRRR RUNS CONTINUING TO SHOW CONSIDERABLE
MOISTURE EROSION UPON ARRIVAL...RESULTING IN TRIMMING OF QPF
GENERATION. ALL OTHER GUIDANCE INCLUDING THE VARIOUS OTHER HI-RES
MODELS SHOW THE CURRENT SWATH OF RAIN ALONG THE WARM FRONT
HOLDING TOGETHER THROUGH OUR AREA.
TONIGHT THE DRY SLOT IN THE WARM SECTOR WILL RESULT IN A LULL IN PRECIPITATION
THAT IS EXPECTED TO LAST THROUGH DAYBREAK. CLOUDS MAY DIMINISH TO
THE POINT WHERE POCKETS OF CLEARING COULD AID THE MONDAY MORNING
WARM-UP AS STRONG SOUTHEASTERLY FLOW VEERS SOUTHERLY. COLDER AIR
ADVANCING EASTWARD ALOFT WILL RESULT IN INSTABILITY AND DRIVE
THUNDERSTORM ACTIVITY ALONG AND AHEAD OF THE COLD FRONT. A SLIGHT
RISK OF SEVERE THUNDERSTORMS IS INCLUDED FOR OUR AREA...WITH THE
MAIN THREAT BEING DAMAGING WINDS. TAX
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
FRONT WILL BE IN OR JUST EAST OF THE RIDGES AT 00Z TUESDAY...WITH
A SECONDARY COLD FRONT LAGGING BEHIND WITH THE UPPER LEVEL COLD
AIR. ENOUGH MOISTURE AND STEEP ENOUGH LAPSE RATES REMAIN BEHIND
THE IMMEDIATE SURFACE BOUNDARY TO KEEP SHRA/TSRA CHANCES GOING
THROUGH MUCH OF THE NIGHT. DRIER AIR SHOULD ALLOW PRECIPITATION TO
CEASE AREAWIDE BY 12Z.
MODELS ARE IN GENERAL AGREEMENT THAT DECAYING MISSISSIPPI VALLEY
SHORTWAVE GETS ABSORBED BY DEEPENING UPPER LOW...WHICH DROPS INTO
THE NORTHERN GREAT LAKES BY 12Z TUESDAY. THIS LEADS TO A TROUGHING
PATTERN FOR THE NORTHEAST U.S. WHICH LOOKS TO PERSIST FOR SOME
TIME. CONFIDENCE IS HIGH IN THESE DETAILS. HOWEVER...TIMING OF
INDIVIDUAL SHORTWAVES ROTATING AROUND BECOMES MORE PROBLEMATIC
WITH TIME.
MAIN VORT LOBE RESIDES IN OR NEAR OUR NORTHERN COUNTIES
TUESDAY. THIS PLUS BETTER INSTABILITY LEADS TO HIGHER POPS IN THIS
AREA TUESDAY AFTERNOON/EVENING. HELD OFF ON THUNDER FOR NOW WITH
EQUILIBRIUM LEVELS MOSTLY BELOW 15K FEET...BUT THIS MAY HAVE TO BE
REEVALUATED WITH COLD TEMPS ALOFT EXPECTED.
A WEAK IMPULSE MAINLY AFFECTS THE SOUTHERN COUNTIES WITH A FEW
SHRA TUESDAY NIGHT. THE NEXT...MORE ORGANIZED...FRONTAL BOUNDARY
ARRIVES WEDNESDAY WITH BETTER RAIN CHANCES AREAWIDE. BEHIND THE
FRONT...BOUNDARY LAYER MAY BE ABLE TO COOL SUFFICIENTLY TO ALLOW
SNOWFLAKES TO MIX IN NORTH OF PIT LATE WEDNESDAY NIGHT...BUT NO
ACCUMULATION IS FORESEEN.
A GENERAL COOLING TREND IN TEMPERATURE WILL BE SEEN WITH VALUES
SINKING BELOW NORMAL BY THE END OF THE PERIOD. CL
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
BROAD UPPER TROUGHING WILL REMAIN OVER THE EASTERN CONUS THROUGH
THE EXTENDED AND RESULT IN BELOW NORMAL TEMPERATURES EACH DAY
ALONG WITH CLOUDY SKIES AND SLIGHT CHANCES FOR PRECIPITATION
THROUGHOUT THE PERIOD AS SHORTWAVES TRANSITION THROUGH THE FLOW
AND CAA ALOFT PERSISTS. CONFIDENCE IS HIGH IN THE GENERAL FORECAST
AS MODELS HAVE BEEN FAIRLY CONSISTENT IN PROGGING THIS LONGWAVE
PATTERN...REFLECTED IN LATEST RMOP AND MODTRENDS GUIDANCE.
HOWEVER...CONFIDENCE IN TIMING OF ANY MORE SIGNIFICANT PERIODS OF
PRECIPITATION IS RELATIVELY LOW. FORECAST MAX/MIN TEMPERATURES ARE
NOT EXCEPTIONALLY COLD...BUT PERSISTENT AROUND 10 DEGREES BELOW
NORMALS AS ENSEMBLE ANOMALIES ARE SHOWING TEMPS AND HEIGHTS ALOFT
ONLY RANGING FROM 1-2 STANDARD DEVIATIONS BELOW NORMAL THROUGH THE
PERIOD.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
HIGH CIRRUS CONTINUES TO MOVE SLOWLY ACROSS THE AREA...BUT NO
RESTRICTIONS ARE ANTICIPATED UNTIL THE RAIN SHOWERS ASSOCIATED
WITH THE WARM FRONT ARRIVE THIS EVENING. EXPECTING RAIN TO FALL
OUT OF MOSTLY VFR CIGS INITIALLY...BUT HEADING INTO THE OVERNIGHT
THE CIGS SHOULD CONTINUE THIER DESCENT TO MVFR. CEILINGS MAY BE
BROKEN AS WE HEAD INTO MIDDAY MONDAY...WITH THUNDERSTORMS EXPECTED
THROUGH AFTERNOON.
GUSTY EAST-SOUTHEASTERLY FLOW WILL CONTINUE EVENING AND
OVERNIGHT...GRADUALLY RELAXING THROUGH THE EARLY MORNING MONDAY.
SURFACE FLOW WILL AGAIN INCREASE AS IT VEERS MORE SOUTHERLY MONDAY
AFTERNOON. TAX
.OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
RESTRICTIONS ARE POSSIBLE WITH A MID WEEK UPPER TROUGH.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
218 PM EDT SUN APR 19 2015
.SYNOPSIS...
SHOWERS WILL OVERSPREAD THE REGION THIS EVENING AND CONTINUE
THROUGH MONDAY. UNSEASONABLY COOL TEMPERATURES ARE EXPECTED FOR
THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
DRY AIR SAMPLED BY THE 12Z UPPER AIR SOUNDING REVEALS A
SUBSTANTIAL LAYER OF DRY AIR. THIS HAS KEPT THE RAIN AND CLOUDS AT
BAY FOR MUCH OF THE DAY...ALLOWING FOR TEMPERATURES TO RISE
QUICKLY ABOVE NORMAL. TEMPERATURE RISES HAVE BEEN AIDED...AT LEAST
IN PART...BY DOWNSLOPING EASTERLY FLOW SUSTAINED AT 10-15KTS WITH
GUSTS CLOSE TO 25KTS.
TEMPERATURES THIS EVENING WILL DECREASE ACROSS THE SOUTH FIRST AS
THE THICKER CLOUD COVER AND EVENTUAL RAIN SHOWERS MOVE IN. TIMING
THE ONSET OF PRECIPITATION HAS BEEN PUSHED BACK AN HOUR OR TWO FOR
MOST LOCATIONS TO ACCOUNT FOR THE DRY AIR IN PLACE. KEEPING
CATEGORICAL POPS IN FOR THIS EVENING/EARLY TONIGHT...DESPITE
SEVERAL OF THE LATEST HRRR RUNS CONTINUING TO SHOW CONSIDERABLE
MOISTURE EROSION UPON ARRIVAL...RESULTING IN TRIMMING OF QPF
GENERATION. ALL OTHER GUIDANCE INCLUDING THE VARIOUS OTHER HI-RES
MODELS SHOW THE CURRENT SWATH OF RAIN ALONG THE WARM FRONT
HOLDING TOGETHER THROUGH OUR AREA.
TONIGHT THE DRY SLOT IN THE WARM SECTOR WILL RESULT IN A LULL IN PRECIPITATION
THAT IS EXPECTED TO LAST THROUGH DAYBREAK. CLOUDS MAY DIMINISH TO
THE POINT WHERE POCKETS OF CLEARING COULD AID THE MONDAY MORNING
WARM-UP AS STRONG SOUTHEASTERLY FLOW VEERS SOUTHERLY. COLDER AIR
ADVANCING EASTWARD ALOFT WILL RESULT IN INSTABILITY AND DRIVE
THUNDERSTORM ACTIVITY ALONG AND AHEAD OF THE COLD FRONT. A SLIGHT
RISK OF THUNDERSTORMS IS INCLUDED FOR OUR AREA...WITH THE MAIN
THREAT BEING DAMAGING WINDS.
TAX
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/...
SHOWER COVERAGE WILL DECREASE OVERNIGHT AS UPPER LEVEL SUPPORT
SHIFTS TO THE EAST AND A LARGE UPPER LEVEL DRY SLOT OVERSPREADS
THE AREA.
THE RESULTING SUBSIDENCE IS EXPECTED TO CONTINUE THROUGH MONDAY
MORNING...AND MAY PROMOTE MODEST HEATING OF A RELATIVELY-MOIST
BOUNDARY LAYER WITH 45-50KT OF SOUTHWEST FLOW ALOFT.
A SECOND SHORTWAVE TROUGH IS PROJECTED TO MOVE QUICKLY NORTHEASTWARD
AND CROSS THE REGION BY LATE DAY. LIFT IN ASSOCIATION WITH THAT
DISTURBANCE WOULD AID CONVECTIVE DEVELOPMENT DURING THE
AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED WITH
THIS SCENARIO. WIDESPREAD SEVERE THUNDERSTORMS ARE NOT EXPECTED
OWING TO PROGNOSIS OF WEAK MID LEVEL LAPSE RATES.
UNUSUALLY STRONG UPPER LOW PRESSURE IS FORECAST TO BUILD SEWD
INTO THE GREAT LAKES REGION BY TUESDAY...WITH ITS ASSOCIATED COLD
FRONT TO CROSS THE FORECAST AREA DURING THE MORNING.
COLD ADVECTION BEHIND THE FRONTAL PASSAGE IS PROGGED TO PROVIDE
INCREASED COVERAGE OF STRATOCU AND POSSIBLE LAKE ENHANCEMENT TO
LIGHT PRECIPITATION...WITH THAT LIMITED TO THE NORTHERN ZONES WITH
EXPECTATIONS OF WESTERLY FETCH AND DRY ADVECTION.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
BROAD UPPER TROUGHING WILL REMAIN OVER THE EASTERN CONUS THROUGH
THE EXTENDED AND RESULT IN BELOW NORMAL TEMPERATURES EACH DAY
ALONG WITH CLOUDY SKIES AND SLIGHT CHANCES FOR PRECIPITATION
THROUGHOUT THE PERIOD AS SHORTWAVES TRANSITION THROUGH THE FLOW
AND CAA ALOFT PERSISTS. CONFIDENCE IS HIGH IN THE GENERAL FORECAST
AS MODELS HAVE BEEN FAIRLY CONSISTENT IN PROGGING THIS LONGWAVE
PATTERN...REFLECTED IN LATEST RMOP AND MODTRENDS GUIDANCE.
HOWEVER...CONFIDENCE IN TIMING OF ANY MORE SIGNIFICANT PERIODS OF
PRECIPITATION IS RELATIVELY LOW. FORECAST MAX/MIN TEMPERATURES ARE
NOT EXCEPTIONALLY COLD...BUT PERSISTENT AROUND 10 DEGREES BELOW
NORMALS AS ENSEMBLE ANOMALIES ARE SHOWING TEMPS AND HEIGHTS ALOFT
ONLY RANGING FROM 1-2 STANDARD DEVIATIONS BELOW NORMAL THROUGH THE
PERIOD.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
HIGH CIRRUS CONTINUES TO MOVE SLOWLY ACROSS THE AREA...BUT NO
RESTRICTIONS ARE ANTICIPATED UNTIL THE RAIN SHOWERS ASSOCIATED
WITH THE WARM FRONT ARRIVE THIS EVENING. EXPECTING RAIN TO FALL
OUT OF MOSTLY VFR CIGS INITIALLY...BUT HEADING INTO THE OVERNIGHT
THE CIGS SHOULD CONTINUE THIER DESCENT TO MVFR. CEILINGS MAY BE
BROKEN AS WE HEAD INTO MIDDAY MONDAY...WITH THUNDERSTORMS EXPECTED
THROUGH AFTERNOON.
GUSTY EAST-SOUTHEASTERLY FLOW WILL CONTINUE EVENING AND
OVERNIGHT...GRADUALLY RELAXING THROUGH THE EARLY MORNING MONDAY.
SURFACE FLOW WILL AGAIN INCREASE AS IT VEERS MORE SOUTHERLY MONDAY
AFTERNOON. TAX
.OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
RESTRICTIONS ARE POSSIBLE WITH A MID WEEK UPPER TROUGH.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DULUTH MN
1220 PM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 945 AM CDT SUN APR 19 2015
RAIN WILL CONTINUE TO AFFECT THE FORECAST AREA THROUGH THE DAY.
HOWEVER...THERE WILL BE AN HOUR OR TWO WHEN NO RAIN IS OCCURRING
AND TRIED TO ACCOUNT FOR THIS IN THE FORECAST. KEPT THE MAX TEMPS
THE SAME FOR NOW...BUT WILL LOOK INTO LOWERING LATER TODAY. REST
OF THE FORECAST IN THE BALLPARK.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
THE FOCUS REMAINS ON THE RAIN TODAY AND TONIGHT. REFINED THE PCPN
CHANCES BY USING A BLEND OF THE RAP13 AND HRRR MODEL RUNS THROUGH
THIS MORNING SINCE THE TWO MODELS SEEM TO BE DOING PRETTY WELL
CAPTURING THE LOCATION OF THE CURRENT RAIN. DID NOT MAKE ANY
DRAMATIC CHANGES TO RAINFALL. OVERALL...MUCH OF THE FORECAST AREA
CAN EXPECT ABOUT 0.30 TO 0.75 INCHES OF RAINFALL THROUGH TONIGHT.
AT 330 AM...AN AREA OF LOW PRESSURE WAS OVER THE BORDER BETWEEN
SOUTH DAKOTA AND SW MINNESOTA. A FRONTAL BOUNDARY EXTENDED
NORTHWARD TO ANOTHER AREA OF LOW PRESSURE IN SOUTHERN MANITOBA.
THERE WAS AN UPPER LEVEL TROUGH OVER THE NORTHERN HIGH PLAINS AND
SASKATCHEWAN/MANITOBA DIGGING AND DEEPENING TOWARDS THE NORTHERN
PLAINS AND ONTARIO. A LARGE AREA OF RAIN WAS LIFTING TO NNE
THROUGH THE SOUTHERN TWO THIRDS OF THE FORECAST AREA. THIS RAIN
WAS ASSOCIATED WITH A BAND OF MID LEVEL FRONTOGENESIS AHEAD OF THE
LOW NEAR THE SD/MN BORDER. THERE WAS ADDITIONAL RAIN IN EASTERN
SOUTH DAKOTA AND NW MINNESOTA MOVING TO THE EAST IN THE WAKE OF
THE TROUGH BOUNDARY AND AHEAD OF THE UPPER LEVEL TO THE WEST. THE
NORTHLAND HAD CLOUDY SKIES WITH TEMPERATURES IN THE UPPER 30S TO
MIDDLE 40S. THE NORTHLAND HAD LIGHT EASTERLY TO SOUTHEASTERLY
WINDS.
THIS MORNING...THE SURFACE LOW NEAR THE SD/MN BORDER WILL LIFT NE
TO THE AITKIN AREA BY THIS AFTERNOON. THE SURFACE LOW IN SOUTHERN
MANITOBA WILL DIG TO THE SE. THE RAIN OVER THE FORECAST AREA EARLY
THIS MORNING WILL CONTINUE LIFTING TO THE NORTH WITH THE BAND OF
MID LEVEL FRONTOGENESIS. PARTS OF THE NORTHERN FORECAST COULD PICK
UP TO AROUND A HALF INCH OF RAIN THROUGH THIS MORNING. THE COLD
FRONT IN NORTH DAKOTA WILL BEGIN TO MOVE INTO THE WESTERN FORECAST
AREA LATE THIS MORNING.
THIS AFTERNOON AND EVENING...THE TWO LOWS WILL GRADUALLY MERGE
INTO ONE LOW OVER NW ONTARIO. CLOUDY AND COOL WEATHER IS EXPECTED
WITH HIGHS RANGING FROM THE UPPER 40S OVER THE NORTH TO THE 50S
OVER THE SOUTH. MOST OF THE AFTERNOON AND EVENING RAIN WILL BE
OVER THE EASTERN FORECAST AREA AHEAD OF THE EASTWARD ADVANCING
COLD FRONT. A DRY SLOT WILL MOVE INTO THE WESTERN FORECAST
AREA...AND THERE COULD BE PARTIAL CLEARING IN THE SW FORECAST
AREA. ALSO...A PROMINENT BAND OF LOW/MID LEVEL FRONTOGENESIS WILL
SET UP OVER NW WISCONSIN THIS EVENING WHICH DEVELOP AND INTENSIFY
A BAND OF RAIN OVER THAT AREA. THE UPPER LEVEL TROUGH OVER THE
NORTHERN PLAINS AND SOUTH CENTRAL CANADA WILL DEEPEN AND DEVELOP
INTO A WELL DEFINED UPPER LEVEL OVER SOUTHERN MANITOBA THIS
AFTERNOON AND CONTINUE DEEPENING AS IT APPROACHES NORTHERN
MANITOBA.
LATER TONIGHT AND EARLY MONDAY...THE COLD FRONT WILL FINISH
MOVING THROUGH THE FORECAST AREA. THE UPPER LEVEL LOW WILL
CONTINUE DEEPENING OVER NW ONTARIO. THE LOW/MID LEVEL
FRONTOGENETICAL BAND IN NW WISCONSIN SHOULD EXIT TO THE EAST BY
AROUND DAWN. TEMPERATURES WILL DROP INTO THE MIDDLE AND LOWER 30S
TONIGHT. THE SYNOPTIC LIFT FROM THE UPPER LEVEL LOW WILL LIKELY
RESULT IN LIGHT RAIN AND SNOW MOVING INTO THE NW FORECAST AREA.
LITTLE OF ANY SNOW ACCUMULATION IS EXPECTED SINCE MUCH OF IT
SHOULD MELT...EITHER ON IMPACT OR LATER IN THE MORNING.
MONDAY...IT WILL BE MUCH COOLER DAY WITH BLUSTERY NW WINDS.
SUSTAINED WINDS OF 10 TO 20 MPH WILL DEVELOP BY THE
AFTERNOON...AND THERE COULD BE GUSTS UP TO 30 MPH. THE 850 HPA
TEMPERATURES WILL BE ABOUT -5 TO -6 DEGREES CELSIUS. HEAVY CLOUD
COVER AND THE COOL NW FLOW WILL PREVENT HIGHS FROM GETTING MUCH
HIGHER THAN THE LOW TO MIDDLE 40S. THERE WILL BE INCREASING
CHANCES OF COLD RAIN SHOWERS AS THE UPPER LOW DEEPENS AND MOVES TO
JUST NORTH OF KOOCHICHING COUNTY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 342 AM CDT SUN APR 19 2015
A DEEP AREA OF LOW PRESSURE WILL SETTLE SOUTHWARD INTO THE LAKE
SUPERIOR REGION MONDAY NIGHT AND TUESDAY. THE CLOSED H5 LOW WILL
REACH WESTERN LAKE SUPERIOR BY TUESDAY AFTERNOON. NUMEROUS
SHOWERS WILL ROTATE SOUTHWARD AROUND THE UPPER LOW...GENERALLY IN
THE FORM OF SNOW SHOWERS AT NIGHT AND RAIN OR SNOW SHOWERS DURING
THE DAY THROUGH THE MIDDLE OF THE WEEK. DEFINITELY COULD BE SOME
SLUSHY ACCUMULATION AT TIMES...ESPECIALLY IN THE NORTH. WOULD NOT
BE SURPRISED TO SEE A COUPLE EPISODES OF UP TO A COUPLE INCHES...
FOLLOWED BY SOME PARTIAL TO FULL MELTING DURING THE DAY. THIS
MASSIVE UPPER LEVEL TROUGH WILL EVENTUALLY LOSE ITS GRIP ON THE
AREA FROM THE MIDDLE TO THE END OF THE WORK WEEK. THE GEM AND TO
SOME EXTENT THE ECMWF ARE THE MOST AGGRESSIVE IN PUSHING THE
UPPER TROUGH EASTWARD THROUGH THE END OF THE WEEK...WITH THE GEM
BRINGING UPPER LEVEL RIDGING ALREADY INTO THE CWA BY 12Z FRIDAY.
THE GFS IS MUCH SLOWER AND DEEPER WITH THE UPPER LEVEL LOW.
STRONGLY FAVORING THE GEM/ECMWF SOLUTION...ESPECIALLY LATE IN THE
WEEK AND INTO THE WEEKEND. HIGH TEMPERATURES WILL REMAIN ON THE
COOL SIDE DURING THE WEEK...REACHING BACK INTO THE LOW TO MID 50S
ON THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1220 PM CDT SUN APR 19 2015
CONDITIONS VARIED FROM LIFR TO MVFR ACROSS THE NORTHLAND WITH
PERIODS OF RAIN/FOG/DRIZZLE MOVING THROUGH THE AREA. THESE
CONDITIONS WILL PERSIST THROUGH THE AFTERNOON INTO TONIGHT. THE
RAIN WILL BE MOST WIDESPREAD OVER EASTERN AREAS...ESPECIALLY
NORTHWEST WISCONSIN TONIGHT. SOUTHWEST AREAS INCLUDING KBRD MAY GO
VFR BRIEFLY LATER THIS EVENING...BUT AS COLDER AIR MOVES BACK IN
ON THE BACKSIDE OF THE LOW...LOWER CEILINGS WILL ONCE AGAIN RETURN.
TEMPERATURES MAY GET COLD ENOUGH FOR SOME SNOW OVER PORTIONS OF
NORTHERN MINNESOTA LATER TONIGHT. GUSTY WEST/NORTHWEST WINDS WILL
ALSO DEVELOP LATER IN THE PERIOD...ESPECIALLY ON MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 34 44 29 / 90 30 30 60
INL 49 32 40 28 / 100 40 60 60
BRD 56 35 43 31 / 80 20 40 40
HYR 58 37 46 30 / 90 80 30 60
ASX 58 37 47 32 / 90 80 20 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR
LSZ142>147.
&&
$$
UPDATE...GSF
SHORT TERM...GROCHOCINSKI
LONG TERM...DAP
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1239 PM CDT Sun Apr 19 2015
.UPDATE...
Issued at 723 AM CDT SUN APR 19 2015
Made major adjustments to the forecast. Lowered PoPs considerably for
the rest of the morning south and west of a h7 vorticity lobe that
defines the back edge of showers over northern and into central
MO...roughly along an arc from St. Joseph to Sedalia. Trend of the
HRRR, RUC and even the NAM supports the above scenario. Convective
cluster over north central OK may graze the far southern counties
this afternoon so likely PoPs this area seems reasonable. So, for a
good portion of today many areas will see little in the way of
measurable rainfall. Still believe we`ll see a band of stratiform
type rain tied to the post-frontal baroclinic zone/deformation zone
that will slide ese across the CWA from late afternoon through this
evening.
&&
.SHORT TERM...(Today through Tuesday)
Issued at 407 AM CDT SUN APR 19 2015
Today - Tonight:
Today`s weather will be governed by the transition of an upper level
closed low to an open wave. Latest water vapor satellite imagery
shows the closed upper low has now shifted east into west central KS
early this morning. A shortwave trough digging into the Northern
High Plains will push this feature and its associated convection
through the CWA today with the rain ending from west to east this
evening.
Scattered showers and isolated thunderstorms will accompany a
couple mid level vorticity lobes as they rotate northeast across KS
and MO. No severe storms are expected today as less than impressive
MUCAPEs in the 400-800 J/kg range and bulk shear values around 25kts
will limit the strength of the storms. Like yesterday a few cells
could produce small hail during peak heating. Temperatures will
again be negatively impacted by the convection and cloud cover. A
more organized band of stratiform rain tied to post-frontal
frontogenesis and an elongated deformation zone overspreads the
region during the evening hours.
Monday - Tuesday:
The Northern Plains upper trough will gradually sharpen south and
shift east on Monday with strong subsidence spilling southeast on
the backside of the trough. Clearing skies will help offset cold air
advection yielding slightly below average temperatures both days.
The operational models are showing similar weak signals on Tuesday
that we`ll need to start considering the chance of some shower
activity. The models generate a series of weak strung out vorticity
lobes stretching southeast from NE through MO. Moisture will be the
main limiting factor so if any rain forms it will be light and
scattered.
.LONG TERM...(Wednesday through Saturday)
Issued at 407 AM CDT SUN APR 19 2015
Slightly below normal temperatures will stretch through the latter
half of the week as deep low pressure very slowly transitions SE
across the Great Lakes, and northwest flow aloft ushers cooler
temperatures into the region. At the same time a surface boundary
will drift southward through Wednesday, leaving the forecast area in
north to northeast surface flow and also helping to keep highs in
the lower to mid 60s. A few light showers and isolated storms are
possible over the southern tier of the CWA Wednesday and Wednesday
night as the front heads south, then a period of drier conditions is
expected on the north side of the boundary Thursday.
Southerly surface flow will eventually return by the end of the work
week ahead of a shortwave trough that will eject out of the desert
southwest and into the Plains by Friday. Widely scattered showers
and storms are possible as early as Friday afternoon, but are more
likely Friday night as the upper trough passes over the CWA. Timing
of this system is still a bit uncertain, and the probability of any
embedded storms will depend on how quickly southerly flow and low-
level moisture return to the region ahead of the shortwave trough.
At this time, the southern track of the associated surface low and
the environment in place ahead of the system suggests that the
potential for strong storms is very low. The clouds and any rain
associated with the system will keep temperatures down despite the
transition to southerly flow, so have kept highs mainly in the lower
60s through the end of the work week and into the weekend. Current
model trends show the wet weather clearing out by Saturday evening
and a dry Sunday, but will have to watch the potential for Friday`s
system to slow down and impact the coming weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 1237 PM CDT SUN APR 19 2015
Rain will stay out of the terminals for the next few hours, but by
this evening rain, with some embedded thunder will move through the
terminals. Expect the bulk of the rainy activity to only last a
couple hours, with perhaps a few lingering hours of low ceilings and
drizzle or very light rain. Expect winds to be gusty all night, but
they should really pick up out of the NW by mid morning on Monday.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...MJ
LONG TERM...Laflin
AVIATION...Leighton
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
129 PM CDT SUN APR 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT SUN APR 19 2015
THE UPPER LOW WHICH PRODUCED UP TO 52 INCHES OF SNOW IN COLORADO
HAS DRIFTED EAST INTO WRN KS THIS MORNING. RAIN AND THUNDERSTORMS
ARE FALLING UNDER THE LOW. A DEFORMATION ZONE OF RAIN AND
ISOLATED THUNDERSTORMS IS WEAKENING ACROSS NCNTL AND SWRN NEB
THIS MORNING. THE MODELS DRAG THIS AREA OF RAIN SOUTH AND OUT OF
THE FORECAST AREA BY 15Z-18Z. A STRONG COLD FRONT WITH SCATTERED
SHOWERS WILL DROP THROUGH THE FCST AREA THIS MORNING SETTING UP A
WINDY AND COOL DAY. NORTHWEST WINDS WILL INCREASE TO 20 TO 30 MPH
WITH GUSTS TO 40 MPH. THESE WINDS ARE ALREADY UNDERWAY IN THE
PANHANDLE.
THE STRONG WINDS BEND AROUND THE BLACK HILLS PRODUCING
CONVERGENCE ACROSS SHERIDAN AND CHERRY COUNTIES. THE HRRR SHOWS
SPRINKLES DEVELOPING BUT GIVEN THE VERY DRY AIR MOVING IN WITH
DEW POINTS FALLING INTO THE 20S BY NOON...NO MEASURABLE RAINFALL
WOULD BE EXPECTED.
HIGHS TODAY RISE INTO THE 50S WITH PARTLY CLOUDY SKIES. THE
MODELS ARE BRINGING IN COLD AIR ALOFT FROM AN UPPER LEVEL ACROSS
MANITOBA. THE RESULT IS H700MB TEMPERATURES FALL TO AROUND -10C
BY 21Z. SOME SUN IS EXPECTED BUT SKIES WOULD LIKELY CLOUD UP IN
THE AFTERNOON WITH THE COLD AIR ALOFT.
TONIGHT...THE UPPER LOW ACROSS WRN KS WILL LIFT INTO THE UPPER
MIDWEST AND BE ABSORBED THE A DISTURBANCE ACROSS WRN ONTARIO
TONIGHT. THIS WILL PULL PACIFIC HIGH PRESSURE INTO THE FCST AREA.
GENERALLY CLEAR SKIES ARE EXPECTED WITH LOWS IN THE 20S TO LOWER
30S. WINDS STAY UP AT 10 TO 15 MPH NEAR ONEILL WHERE THE WARMER
LOWS ARE EXPECTED.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 313 AM CDT SUN APR 19 2015
MONDAY INTO MID WEEK WILL SEE THE LOW PRESSURE SYSTEMS TO THE
NORTHEAST AND EAST MERGE NEAR/NORTH OF THE GREAT LAKES. MEANWHILE
NORTHWEST FLOW DOMINATES THE HIGH PLAINS AND AN UPPER LEVEL
TROUGH DIGS ACROSS THE PACIFIC COAST. THE LOW PRESSURE SYSTEM TO
THE NORTHEAST WILL DRAW SOME COOL AND DRY CANADIAN AIR TO THE
REGION. TEMPERATURES WILL BE THE MAIN FOCUS THROUGH MID WEEK AND
ARE TRICKY. THE DRY AIR MOVING SOUTH WILL ALLOW FOR DEW POINTS TO
FALL INTO THE TEENS AND 20S...HOWEVER WITH THE RECENT HEAVY
RAIN...THOUGHT MODELS ARE A TAD TO DRY SO DID RAISE SLIGHTLY BUT
COULD SEE THEM BEING HIGHER...ESPECIALLY BY WED. SKIES WILL
GENERALLY BE MOSTLY CLEAR...ALTHOUGH A COUPLE WEAK CLIPPERS MAY
BRING A BRIEF INCREASE OF CLOUDS. WITH MOSTLY CLEAR SKIES AND DRY
AIR TEMPS TO LIKELY FALL TO OR BELOW THE FREEZING MARK FOR THE
FIRST FEW DAYS OF THE WEEK...UNLESS BL MOISTURE ENDS UP BEING
MORE THAN EXPECTED FROM RECENT RAIN. MEANWHILE AFTERNOON SUN WILL
HELP OFFSET THE COOL CONDITIONS AND BE ABLE TO AID IN MIXING THE
BL...SEASONAL HIGHS /50S AND 60S/ EXPECTED. ONE CONCERN WITH
HIGHS IS THE COOL TEMPS ALOFT...WHICH MAY RESULT IN SOME
AFTERNOON CLOUDS DUE TO STEEP LAPSE RATES DEVELOPING. FAIRLY DRY
AIR AT THE SFC SO NOTHING EXPECTED TO REACH THE GROUND.
BY THE END OF THE WEEK THE WEST COAST TROUGH WILL BECOME AN OPEN
WAVE CROSSING THE DESERT SW/4 CORNERS. A TRANSITION FROM NW TO SW
FLOW WILL BRING A RETURN FOR WET WEATHER. MODELS NOT IN THE BEST
OF AGREEMENT ON TIMING...BUT DO PUSH THE WAVE ONTO THE
SOUTHERN/CENTRAL PLAINS BY THE WEEKEND. SHOULD SEE A BRIEF WINDOW
OF RETURN MOIST SOUTHEASTERLY FLOW AHEAD OF THE WAVE. THIS TRACK
AND THE INCREASE OF MOISTURE WILL FAVOR A CHANCE FOR
RAIN...ALBEIT BETTER FOR SOUTHERN ZONES THAN NORTHERN ZONES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 116 PM CDT SUN APR 19 2015
THE LARGE SLOW MOVING STORM SYSTEM RESPONSIBLE FOR THE WEATHER OF
LATE WILL CONTINUE TO MOVE AWAY FROM THE AREA. VFR CONDITIONS WILL
BE THE RULE...WITH GUSTY NORTHWEST WINDS UP TO 35 KTS THIS
AFTERNOON. WINDS WILL DIMINISH TONIGHT...BUT INCREASE ONCE AGAIN
MONDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1149 AM MDT SUN APR 19 2015
.AVIATION...
18Z TAF CYCLE
STRONG BACKDOOR COLD FRONT HAS MOVED SOUTH ACROSS OF THE EASTERN
PLAINS. N WIND GUSTS OF 30 TO 35 KT WILL CONTINUE FOR A COUPLE
MORE HOURS AT RTN AND TCC BEFORE DIMINISHING. GUSTS AROUND 40 KT
AT CAO AND CVN. THE BACKDOOR FRONT WILL HELP TRIGGER ISOLATED
AFTERNOON AND EARLY EVE -SHRA AND -TSRA TODAY...MAINLY OVER THE
SANGRE DE CRISTO MOUNTAINS AND ACROSS THE NE. MORE ISOLATED
ACTIVITY POSSIBLE ALONG THE CENTRAL MOUNTAIN CHAIN AND THEIR E
SLOPES. WILL CARRY VCTS AND VCSH AT LVS WITH NO MENTION AT THE
OTHER TAF SITES. ISOLATED...HIGHER BASED CONVECTION POSSIBLE
ACROSS THE SW MTS THIS AFTN. LATE TONIGHT THERE IS A POSSIBILITY
OF SOME NEAR MVFR CIGS ACROSS THE E...INCLUDING LVS..TCC AND ROW.
&&
.PREV DISCUSSION...913 AM MDT SUN APR 19 2015...
.UPDATE...
ADDED QUAY AND CURRY COUNTIES TO THE WIND ADVY FOR TODAY AND
TWEAKED UP WIND SPEEDS OUT THERE. OTHERWISE NO CHANGES.
&&
.PREV DISCUSSION...337 AM MDT SUN APR 19 2015...
.SYNOPSIS...
AN OVERALL UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE NORTHERN
HIGH TERRAIN AND THE NORTHEAST PLAINS THROUGH ALL OF THIS WEEK. HIGH
TEMPERATURES WILL SLOWLY TREND BACK TOWARD NORMAL THROUGH THE MIDDLE
OF THE WEEK AHEAD OF THE NEXT STORM SYSTEM APPROACHING FROM THE WEST.
DRY SOUTHWEST WINDS WILL INCREASE WEDNESDAY AND THURSDAY FOR WESTERN
AND CENTRAL NEW MEXICO. THE CHANCES FOR SHOWERS AND THUNDERSTORMS
WILL INCREASE AGAIN FOR ALL AREAS FRIDAY AS THE CORE OF AN UPPER LOW
SLIDES OVERHEAD. COOLER TEMPERATURES WILL MOVE BACK INTO THE AREA
BEHIND THIS SYSTEM...WHILE THE CHANCES OF PRECIPITATION CONTINUE
OVER THE NORTH THROUGH NEXT WEEKEND.
&&
.DISCUSSION...
THE FINAL VESTIGES OF WRAP-AROUND PRECIP ARE IMPACTING THE FRONT
RANGE OF COLORADO THIS MORNING AS EVIDENCED BY WIDESPREAD SHOWERS
AND GUSTY NORTH WINDS. THIS ACTIVITY IS INDICATED BY THE 00Z/06Z
NAM AND HRRR GUIDANCE TO CLIP NORTHEAST NM THIS MORNING. QPF WILL
BE LIGHT WITH MOST AREAS REPORTING LESS THAN A TENTH. HIGHS AGAIN
TODAY WILL BE BELOW NORMAL ALL AREAS...WITH READINGS 10-15F BELOW
NORMAL FOR THE EAST. HIGH PRESSURE BUILDING DOWN THE FRONT RANGE
TONIGHT BEHIND THE DEPARTING UPPER LOW WILL HELP FORCE LIGHT GAP
WINDS INTO THE RIO GRANDE VALLEY LATE TONIGHT.
ONE LAST UPPER VORT TRANSLATION WITHIN NW FLOW BEHIND THE DEPARTING
WAVE WILL SLIDE OVER THE NORTHERN MTS AND NE PLAINS MONDAY. THIS
WILL FORCE ANOTHER ROUND OF AFTERNOON SHOWERS NEAR THE HIGH TERRAIN
AS FAR SOUTH AS I-40. AGAIN TEMPS WILL BE BELOW NORMAL WITH A SLIGHT
TREND TOWARD NORMAL FOR THE FAR WEST.
AN AMORPHOUS COMPLEX OF UPPER LEVEL LOW PRESSURE CURRENTLY TAKING
SHAPE ALONG THE WEST COAST WILL BECOME THE NEXT WEATHER PLAYER FOR
MID TO LATE WEEK. GUIDANCE SHOWS H5 HEIGHTS DEEPENING INTO A 562DM
LOW TUESDAY OVER SOUTHERN CALIFORNIA WITH A WEAK SHORTWAVE RIDGE
SLIDING OVER NM. THIS WILL TREND SHOWER AND WIND ACTIVITY DOWNWARD
FOR NM. A 90-110KT 300MB JET AXIS THEN CARVES SOUTHWARD ALONG THE
WEST COAST AND DEEPENS THE TROUGH INTO A TIGHTLY WOUND 550DM H5 LOW
OVER SOUTHERN CALIFORNIA THROUGH THURSDAY. THIS WILL INCREASE MID
LEVEL FLOW AND DEEPEN THE LEE SIDE TROUGH OVER EASTERN NM. WINDS
AND TEMPS WILL INCREASE OVER THE STATE WITH SOME POSSIBLE MARGINAL
FIRE WEATHER ISSUES NOTED WEDNESDAY AND/OR THURSDAY.
BEYOND THURSDAY THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE
TRANSLATION OF LOW PRESSURE OVER NM BY FRIDAY/SATURDAY AND INTO
NEXT WEEK. THE GFS AND ECMWF OPEN THE WAVE AND SLIDE DISORGANIZED
PRECIP OVER THE AREA...FOLLOWED BY A SERIES OF FAST MOVING WEAKLY
DEFINED SHORTWAVE TROUGHS AND RIDGES.
GUYER
&&
.FIRE WEATHER...
WHILE SOME POTENTIAL STILL REMAINS...AS IT CURRENTLY LOOKS THE RISK
OF A RETURN OF CRITICAL FIRE WX CONDITIONS THURSDAY AND FRIDAY HAS
DIMINISHED SOMEWHAT.
A BACK DOOR FRONT MOVING ACROSS THE EASTERN PLAINS THIS MORN AND
INTO THE AFTN WILL BRING INCREASINGLY STRONG AND GUSTY WINDS TO THE
NE PLAINS AND TO A LESSER DEGREE THE EAST CENTRAL PLAINS THIS MORN.
GUSTS NEAR 45 OR 50 MPH ARE POSSIBLE NEAR CLAYTON THIS MORN. WIND
SPEEDS ARE EXPECTED TO DECREASE SOMEWHAT THIS AFTN. CRITICAL FIRE WX
CONDITIONS NOT EXPECTED AS HUMIDITIES TO REMAIN TOO HIGH. AFTN TEMPS
WILL ONLY BE SLIGHTLY COOLER TODAY AS COMPARED TO SATURDAY BEHIND
THE FRONT. AS THE FRONT BACKS UP TO THE CENTRAL MTN CHAIN...EXPECT A
FEW HIGH BASED SHOWERS AND THUNDERSTORMS TO DEVELOP DUE TO UPSLOPE
FLOW...MORE SO ALONG THE EAST SLOPES OF THE SANGRE DE CRISTO MTNS
AND LESS SO FARTHER SOUTH. HUMIDITY RECOVERIES TONIGHT WILL BE GOOD
TO EXCELLENT MOST AREAS OUTSIDE OF WEST CENTRAL AND SW NM WHERE FAIR
TO GOOD RECOVERIES TO BE THE RULE. LOW TEMPS WILL BE A LITTLE ABOVE
NORMAL WEST AND CENTRAL...A BIT BELOW EAST. HIGH TEMPS ON SUNDAY
WILL REMAIN BELOW NORMAL ACROSS THE EAST DUE TO THE FRONTAL
PASSAGE...THOUGH WILL BE INCHING UP TOWARD NORMAL ACROSS THE WEST.
LATER MON...WEAK RIDGE ALOFT WILL DEVELOP ACROSS WESTERN NM...THOUGH
ENOUGH RESIDUAL MOISTURE WILL BE AROUND TO TRIGGER A FEW HIGH BASED
BUILDUPS AND VIRGA IN THE AFTERNOON HOURS. A FEW SPRINKLES MAY
ACTUALLY REACH THE GROUND ACROSS THE NORTHERN HIGH TERRAIN...THOUGH
THE BIGGER CONCERN MAY BE ERRATIC WIND GUSTS WITH ANY VIRGA ACROSS
WESTERN NM. OTHERWISE TEMPS SHOULD WARM TO AROUND 5 DEGREES OF
NORMAL EAST...VERY CLOSE TO NORMAL WEST.
THE BACK DOOR COLD FRONT EARLIER SCHEDULED TO ARRIVE LATER MON NIGHT
INTO TUE MORN HAS BEEN MARGINALIZED AND IN SOME MODELS ELIMINATED
FROM THE SCENE COMPLETELY. STILL MAY BE JUST ENOUGH MOISTURE AND
WEAK UPSLOPE TO CREATE A FEW SHOWERS AND THUNDERSTORMS TUE AFTN WITH
AID OF AFTN HEATING.
WED LOOKS TO BE BREEZY IN MANY AREAS...BUT FOR THE MOST PART THE
STRONGEST WINDS STILL ARE EXPECTED TO ARRIVE THU AND FRI. BUT
CRITICAL CONDITIONS HAVE SHRUNK SIGNIFICANTLY THU AND DO NOT APPEAR
AT ALL FOR FRI. THIS MAY ONLY BE A TEMPORARY REDUCTION AS FCST
MODELS SEEM TO BE IN TRANSITION AGAIN IN THEIR DEPICTION OF UPPER
LVL LOW PRESSURE EVOLUTION OFF TO OUR WEST. THE BACK DOOR FRONT WILL
BE REINFORCED ACROSS NE NM AND SOME THUNDERSTORMS MAY DEVELOP THERE
THU AFTN.
NO VENTILATION ISSUES ARE EXPECTED FOR THE NEXT 6 DAYS...WITH MAINLY
VERY GOOD TO EXCELLENT VENT RATES EXPECTED...THOUGH FAR NORTHEAST NM
MAY DROP INTO THE FAIR OR GOOD CATEGORIES MID TO LATE WEEK. SAT MAY
SEE SOME EROSION OF VENTILATION RATES.
43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ530-534-535.
&&
$$
40
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
622 PM EDT SUN APR 19 2015
.SYNOPSIS...
A FRONTAL SYSTEM WILL BRING SHOWERS AND A FEW THUNDERSTORMS
THROUGH MONDAY. A FEW STORMS MAY BE STRONG TO SEVERE. DRY AND
SEASONABLE HIGH PRESSURE WILL BUILD INTO THE AREA TUESDAY AND
WEDNESDAY. WARMER TEMPERATURES ARE EXPECTED THURSDAY AHEAD OF
THE NEXT COLD FRONT. MUCH COOLER TEMPERATURES ARE POSSIBLE
LATE WEEK AND INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 555 PM SUNDAY...TORNADO WATCH NUMBER 82 THRU 11 PM REMAINS
IN EFFECT FOR THE ILM SC CWA...PLUS ROBESON COUNTY OF THE ILM NC
CWA.
BROKEN LINE OF STRONG TO SEVERE THUNDERSTORMS IS ON THE WESTERN
DOORSTEPS OF THE ILM CWA AT THE MOMENT. POPS HAVE BEEN RE-ADJUSTED
THRUOUT THIS EVENING TO TAKE INTO ACCOUNT OF THE TIMING AND
PROGRESSION OF THIS LINE AS IT TRAVERSES THE ILM CWA. AT THIS
POINT...THE CUMULATIVE THINKING IS THAT THE CONVECTION WILL WEAKEN
TO BELOW SEVERE LIMITS BY THE TIME IT PROGRESSES ACROSS THE ILM NC
COUNTIES LATER THIS EVENING AND OVERNIGHT AND THEREFORE A WATCH IS
WAS NOT PLANNED AT THIS TIME.
PREVIOUS........................................................
AS OF 315 PM SUNDAY...AS LIGHT STRATIFORM RAINFALL PULLS NE AWAY
FROM THE REGION THIS AFTERNOON...A MORE ORGANIZED BAND OF SHOWERS
AND TSTMS WILL MOVE INTO NE SC 6 PM - 7 PM...AND INTO SE NC IN THE
MIDDLE AND LATE EVENING. THIS IS APT TO BRING SIGNIFICANTLY MORE
RAINFALL AMOUNTS TO THE AREA TONIGHT. SATELLITE DERIVED SENSORS OF
PRECIPITABLE WATERS SHOW A LARGE SWATH OF 46MM/1.81 INCH PWATS
MOVING INTO THE AREA THAT WILL HELP FUEL THE CONVECTION. SEVERAL
ISOLATED OR DISCREET CELLS MAY ALSO FIRE AHEAD OF THE ORGANIZED
RAIN AREA AFTER THE STRATIFORM RAIN HAS CLEARED. SEVERAL RECENT
NEAR TERM MODELS SHOWS THE BULK OF RAINFALL MOVING NE OF SE NC
AFTER 5Z/1AM. THE ORGANIZED NATURE OF THIS FEATURE IF HELD INTACT
WILL INTRODUCE A SLIGHT CHANCE OF WIND DAMAGE OR HAIL TONIGHT.
MINIMUMS TONIGHT WILL NOT FALL MUCH BELOW THE MIDDLE 60S EVEN IN
RAIN COOLED LOCATIONS AS DEWPOINTS REMAIN ELEVATED.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...THE CWA WILL BE IN A RATHER WARM AND BLUSTERY
SOUTHWEST FLOW AT THE BEGINNING OF THE PERIOD...IN BETWEEN A
DEPARTING WARM FRONT TO THE NORTHEAST AND A COLD FRONT ACROSS THE
TENNESSEE VALLEY. THIS FRONT MOVES STEADILY ACROSS THE SOUTHEAST
DURING THE DAY AND SHOULD BE JUST ACROSS OUR WESTERN COUNTIES BY
0000 UTC TUESDAY. SEVERE PARAMETERS STILL LOOK CONDUCIVE FOR AN
EVENT WITH ADEQUATE INSTABILITY AND SHEAR. HOWEVER HIGH
RESOLUTION GUIDANCE IS SHOWING A LACK OF ACTIVITY WITH THE FRONT.
THE MET HAS SIX HOUR POPS IN THE SINGLE DIGITS FOR THE 18-00 UTC
TIME FRAME IN LBT AND ILM. THE GFS REMAINS MORE BULLISH WITH
SCATTERED ACTIVITY AHEAD OF A CONVECTIVE LINE. WILL MAINTAIN THE
CHANCE POPS AND FINE TUNE FOR THE TIMING FOR LATE AFTERNOON INTO
THE EVENING. SPC MAINTAINS THE SLIGHT RISK FOR THE AREA CITING THE
UNCERTAINTY. BEYOND THIS HIGH PRESSURE BUILDS IN FOR A NICE
TUESDAY AND PEACEFUL WEDNESDAY MORNING.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...HIGH PRESSURE BOTH MOVES OFFSHORE AND WEAKENS
CONSIDERABLY. PAIR THIS WITH ZONAL MID FLOW AND THE AFTERNOON SHOULD
BE SEASONABLE AND RAIN-FREE WITH A FAIR AMOUNT OF SUNSHINE. THE
APPROACH OF A COLD FRONT WILL YIELD A SMALL RISE IN POPS ON THURSDAY
OR POSSIBLY EVEN WEDNESDAY NIGHT. THIS SLOW MOVING BOUNDARY MOVES
THROUGH ON THURSDAY BUT WILL HAVE TO DEAL WITH MIDLEVEL DOWNSLOPING
PREVENTING DEEP MOISTURE. THE FRONT STALLS SOUTH OF THE REGION
POSSIBLY CLOSE ENOUGH FOR THE MAINTENANCE OF LOW END POPS. SOME
DEEPER MOISTURE AND MORE MEANINGFUL RAIN CHANCES MAY MATERIALIZE
OVER THE WEEKEND AS THE FRONT REMAINS TO OUR SOUTH BUT SOME WEAK MID
LEVEL IMPULSES WORK TO PROVIDE LIFT ATOP SOME LOW LEVEL ISENTROPIC
UPGLIDE.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...SOME CONVECTION IS TRYING TO MOVE ONSHORE NEAR
ILM...OTHERWISE THE COASTAL TERMINALS MAY NOT SEE TOO MUCH ACTION
INITIALLY. MAINLY A EAST SOUTHEAST WIND THIS AFTERNOON. THIS
EVENING...THE HRRR IS STAYING FAIRLY CONSISTENT IN BRINGING IN AN
ORGANIZED LINE OF OF CONVECTION TO THE INLAND TERMINALS AROUND 23Z.
WILL LEAN HEAVILY ON THIS MODEL THROUGH THE EVENING HOURS. AFTER THE
CONVECTION MOVES THROUGH...EXPECT IFR CEILING THROUGH THE OVERNIGHT
HOURS...WITH SOME LIGHT FOG. MONDAY...IMPROVING CEILINGS AS THE DAY
WEARS ON WITH A GUSTY SOUTHWEST WIND. CONVECTION IS EXPECTED TO FIRE
AFTER THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...A COLD FRONT WILL PUSH THROUGH THE AREA MONDAY
NIGHT WITH SHOWERS POSSIBLE FOLLOWED BY MAINLY VFR CONDITIONS
TUESDAY AND WEDNESDAY. POSSIBLE SHOWERS THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 555 PM SUNDAY...TOR WATCH 82 AFFECTS THE ILM SC WATERS THRU
11 PM. THE MARINE BOUNDARY LAYER OVER THE COOLER SHELF WATERS
WILL ACT TO WEAKEN CONVECTION AS IT REACHES AND MOVES ACROSS ALL
WATERS DURING THIS EVENING. THE STRONGER STORMS THIS EVENING THAT
AFFECT THE ILM SC WATERS COULD PRODUCE SMW CRITERIA BRIEF GALE
FORCE WIND GUSTS OR WATERSPOUTS. OTHERWISE...THE MAJORITY OF THE
CONVECTION WILL PRODUCE MWS CRITERIA WINDS AND LIGHTNING.
PREVIOUS........................................................
AS OF 315 PM SUNDAY...SEAS SLOWLY ON THE RISE IN THE MODERATE
ONSHORE WIND FLOW AND 3-5 FOOT SEAS EXPECTED OVERNIGHT. SEVERAL
TSTMS ARRIVING FROM THE SW TONIGHT MAY PRODUCE LOCALLY HIGHER WINDS
AND SEAS...AND SEVERAL SPECIAL MARINE WARNINGS MAY BE NEEDED FOR
TONIGHT WITH CLOUD TO SEA LIGHTNING POSING AN ADDITIONAL HAZARD.
WINDS WILL VEER TO S AND SW OVERNIGHT WHICH WILL HELP TO LIMIT WAVE
GROWTH AND A SMALL CRAFT ADVISORY IS NOT PLANNED ALTHOUGH AN
EXERCISE CAUTION STATEMENT COULD BE NEEDED.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...A SOUTHWEST FLOW OF 10-15 KNOTS INITIALLY WILL
INCREASE TO 15-20 BY THE END OF THE DAY MONDAY AS A FRONT MOVES
CLOSER FROM THE WEST. THE FRONT FINALLY CROSSES THE WATERS EARLY
TUESDAY MORNING WITH A MODEST WESTERLY FLOW OF 10-15 KNOTS IN ITS
WAKE. SMOOTH SAILING FOR THE REMAINDER OF THE PERIOD WITH WINDS TEN
KNOTS OR LESS FROM THE WEST NORTHWEST AND SEAS OF 2-4 FEET.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...WEDNESDAY BRINGS NEARLY MINIMAL WIND AND SEAS
DUE TO HIGH PRESSURE MOVING OVERHEAD. WINDS THOUGH LIGHT WILL VEER
CONSIDERABLY AS THE DAY PROGRESSES UNTIL A S TO SW FLOW BECOMES
PREDOMINANT LATE IN THE DAY OR AT NIGHT. MORE VEERING IS SLATED FOR
THURSDAY AS A COLD FRONT APPROACHES AND VERY SLOWLY CROSSES THE
WATERS. WITH THIS FRONT STALLING NEARBY TO OUR SOUTH ON FRIDAY A
LIGHT NORTHERLY FLOW WILL BE MAINTAINED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH/MJC
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...MJC/SHK/DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
319 PM EDT SUN APR 19 2015
.SYNOPSIS...
A FRONTAL SYSTEM WILL BRING SHOWERS AND A FEW THUNDERSTORMS
THROUGH MONDAY. A FEW STORMS MAY BE STRONG TO SEVERE. DRY AND
SEASONABLE HIGH PRESSURE WILL BUILD INTO THE AREA TUESDAY AND
WEDNESDAY. WARMER TEMPERATURES ARE EXPECTED THURSDAY AHEAD OF
THE NEXT COLD FRONT. MUCH COOLER TEMPERATURES ARE POSSIBLE
LATE WEEK AND INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 315 PM SUNDAY...AS LIGHT STRATIFORM RAINFALL PULLS NE AWAY
FROM THE REGION THIS AFTERNOON...A MORE ORGANIZED BAND OF SHOWERS
AND TSTMS WILL MOVE INTO NE SC 6 PM - 7 PM...AND INTO SE NC IN THE
MIDDLE AND LATE EVENING. THIS IS APT TO BRING SIGNIFICANTLY MORE
RAINFALL AMOUNTS TO THE AREA TONIGHT. SATELLITE DERIVED SENSORS OF
PRECIPITABLE WATERS SHOW A LARGE SWATH OF 46MM/1.81 INCH PWATS
MOVING INTO THE AREA THAT WILL HELP FUEL THE CONVECTION. SEVERAL
ISOLATED OR DISCREET CELLS MAY ALSO FIRE AHEAD OF THE ORGANIZED
RAIN AREA AFTER THE STRATIFORM RAIN HAS CLEARED. SEVERAL RECENT
NEAR TERM MODELS SHOWS THE BULK OF RAINFALL MOVING NE OF SE NC
AFTER 5Z/1AM. THE ORGANIZED NATURE OF THIS FEATURE IF HELD INTACT
WILL INTRODUCE A SLIGHT CHANCE OF WIND DAMAGE OR HAIL TONIGHT.
MINIMUMS TONIGHT WILL NOT FALL MUCH BELOW THE MIDDLE 60S EVEN IN
RAIN COOLED LOCATIONS AS DEWPOINTS REMAIN ELEVATED.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...THE CWA WILL BE IN A RATHER WARM AND BLUSTERY
SOUTHWEST FLOW AT THE BEGINNING OF THE PERIOD...IN BETWEEN A
DEPARTING WARM FRONT TO THE NORTHEAST AND A COLD FRONT ACROSS THE
TENNESSEE VALLEY. THIS FRONT MOVES STEADILY ACROSS THE SOUTHEAST
DURING THE DAY AND SHOULD BE JUST ACROSS OUR WESTERN COUNTIES BY
0000 UTC TUESDAY. SEVERE PARAMETERS STILL LOOK CONDUCIVE FOR AN
EVENT WITH ADEQUATE INSTABILITY AND SHEAR. HOWEVE HIGH RESOLUTION
GUIDANCE IS SHOWING A LACK OF ACVITITY WITH THE FRONT. THE MET HAS
SIX HOUR POPS IN THE SINGLE DIGITS FOR THE 18-00 UTC TIME FRAME IN
LBT AND ILM. THE GFS REMAINS MORE BULLISH WITH SCATTERED ACTIVITY
AHEAD OF A CONVECTIVE LINE. WILL MAINTAIN THE CHANCE POPS AND FINE
TUNE FOR THE TIMING FOR LATE AFTERNOON INTO THE EVENING. SPC
MAINTAINS THE SLIGHT RISK FOR THE AREA CITING THE UNCERTAINTY.
BEYOND THIS HIGH PRESSURE BUILDS IN FOR A NICE TUESDAY AND PEACEFUL
WEDNESDAY MORNING.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...HIGH PRESSURE BOTH MOVES OFFSHORE AND WEAKENS
CONSIDERABLY. PAIR THIS WITH ZONAL MID FLOW AND THE AFTERNOON SHOULD
BE SEASONABLE AND RAIN-FREE WITH A FAIR AMOUNT OF SUNSHINE. THE
APPROACH OF A COLD FRONT WILL YIELD A SMALL RISE IN POPS ON THURSDAY
OR POSSIBLY EVEN WEDNESDAY NIGHT. THIS SLOW MOVING BOUNDARY MOVES
THROUGH ON THURSDAY BUT WILL HAVE TO DEAL WITH MIDLEVEL DOWNSLOPING
PREVENTING DEEP MOISTURE. THE FRONT STALLS SOUTH OF THE REGION
POSSIBLY CLOSE ENOUGH FOR THE MAINTENANCE OF LOW END POPS. SOME
DEEPER MOISTURE AND MORE MEANINGFUL RAIN CHANCES MAY MATERIALIZE
OVER THE WEEKEND AS THE FRONT REMAINS TO OUR SOUTH BUT SOME WEAK MID
LEVEL IMPULSES WORK TO PROVIDE LIFT ATOP SOME LOW LEVEL ISENTROPIC
UPGLIDE.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...SOME CONVECTION IS TRYING TO MOVE ONSHORE NEAR
ILM...OTHERWISE THE COASTAL TERMINALS MAY NOT SEE TOO MUCH ACTION
INITIALLY. MAINLY A EAST SOUTHEAST WIND THIS AFTERNOON. THIS
EVENING...THE HRRR IS STAYING FAIRLY CONSISTENT IN BRINGING IN AN
ORGANIZED LINE OF OF CONVECTION TO THE INLAND TERMINALS AROUND 23Z.
WILL LEAN HEAVILY ON THIS MODEL THROUGH THE EVENING HOURS. AFTER THE
CONVECTION MOVES THROUGH...EXPECT IFR CEILING THROUGH THE OVERNIGHT
HOURS...WITH SOME LIGHT FOG. MONDAY...IMPROVING CEILINGS AS THE DAY
WEARS ON WITH A GUSTY SOUTHWEST WIND. CONVECTION IS EXPECTED TO FIRE
AFTER THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...A COLD FRONT WILL PUSH THROUGH THE AREA MONDAY
NIGHT WITH SHOWERS POSSIBLE FOLLOWED BY MAINLY VFR CONDITIONS
TUESDAY AND WEDNESDAY. POSSIBLE SHOWERS THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 315 PM SUNDAY...SEAS SLOWLY ON THE RISE IN THE MODERATE
ONSHORE WIND FLOW AND 3-5 FOOT SEAS EXPECTED OVERNIGHT. SEVERAL
TSTMS ARRIVING FROM THE SW TONIGHT MAY PRODUCE LOCALLY HIGHER WINDS
AND SEAS...AND SEVERAL SPECIAL MARINE WARNINGS MAY BE NEEDED FOR
TONIGHT WITH CLOUD TO SEA LIGHTNING POSING AN ADDITIONAL HAZARD.
WINDS WILL VEER TO S AND SW OVERNIGHT WHICH WILL HELP TO LIMIT WAVE
GROWTH AND A SMALL CRAFT ADVISORY IS NOT PLANNED ALTHOUGH AN
EXERCISE CAUTION STATEMENT COULD BE NEEDED.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...A SOUTHWEST FLOW OF 10-15 KNOTS INITIALLY WILL
INCREASE TO 15-20 BY THE END OF THE DAY MONDAY AS A FRONT MOVES
CLOSER FROM THE WEST. THE FRONT FINALLY CROSSES THE WATERS EARLY
TUESDAY MORNING WITH A MODEST WESTERLY FLOW OF 10-15 KNOTS IN ITS
WAKE. SMOOTH SAILING FOR THE REMAINDER OF THE PERIOD WITH WINDS TEN
KNOTS OR LESS FROM THE WEST NORTHWEST AND SEAS OF 2-4 FEET.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...WEDNESDAY BRINGS NEARLY MINIMAL WIND AND SEAS
DUE TO HIGH PRESSURE MOVING OVERHEAD. WINDS THOUGH LIGHT WILL VEER
CONSIDERABLY AS THE DAY PROGRESSES UNTIL A S TO SW FLOW BECOMES
PREDOMINANT LATE IN THE DAY OR AT NIGHT. MORE VEERING IS SLATED FOR
THURSDAY AS A COLD FRONT APPROACHES AND VERY SLOWLY CROSSES THE
WATERS. WITH THIS FRONT STALLING NEARBY TO OUR SOUTH ON FRIDAY A
LIGHT NORTHERLY FLOW WILL BE MAINTAINED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...MJC
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
201 PM EDT SUN APR 19 2015
.SYNOPSIS...
HIGH PRESSURE EXTENDING OVER THE AREA FROM THE NORTH WILL SHIFT
OFFSHORE TODAY. A WARM FRONT WILL LIFT NORTHEAST ACROSS THE AREA
TONIGHT AS LOW PRESSURE MOVES INTO THE OHIO VALLEY. A COLD FRONT
WILL MOVE THROUGH FROM THE WEST EARLY TUESDAY FOLLOWED BY HIGH
PRESSURE WEDNESDAY. ANOTHER COLD FRONT WILL MOVE IN FROM THE
NORTHWEST THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 110 PM SUNDAY...FORECAST PRETTY MUCH ON TRACK WITH A
MODERATE TO HEAVY SHOWERS DRIFTING IN FROM THE OCEAN AND THE
LEADING EDGE OF THE WIDESPREAD RAIN SHIELD IS MOVING INTO SOUTH
CENTRAL NORTH CAROLINA. GENERALLY FOLLOWED THE 3KM HRRR WHICH IS
DOING A GOOD JOB OF DEPICTING THE RAINFALL. NO CHANGES THROUGH THE
AFTERNOON AS RAIN BECOMES WIDESPREAD AND STEADY. CONVECTIVE
DEVELOPMENT POTENTIAL SEEMS LIMITED BASED ON CURRENT PARAMETERS AS
BEST INSTABILITY OCCURRING MUCH FURTHER SOUTHWEST ACROSS
GEORGIA...ALABAMA AND THE FLORIDA PANHANDLE. NO CHANGE TO
TEMPERATURE FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 400 AM SUNDAY...LATEST GDNC CONTINUES TO INDICATE WET
CONDITIONS TONIGHT AND INCREASED POPS TO 100% ALL ZONES. DIFFLUENT
UPR FLOW AHEAD OF UPR TROF LIFTING OUT OF SRN PLAINS WILL INDUCE
LARGE SCALE ASCENT ACROSS AREA ALONG WITH DEEP MSTR PLUME FROM
GULFMEX. SFC WARM FRONT WILL APPROACH FROM SW AS DEVELOPING LOW
PRES MOVES INTO WRN OH VLY. WDSPRD SHOWERS AND PSBLY SCT TSTMS
EXPECTED TO GRADUALLY SPREAD SW TO NE ACROSS ERN NC OVERNIGHT. QPF
LOWERED SLIGHTLY BASED ON HPC AND LATEST MODEL BLEND...BUT MOST
AREAS STILL SEEING 1/2 TO 1 INCH.
PER NEAR-TERM...MARGINAL SVR THREAT FOR SW SECTIONS WITH SOME
POTENTIAL FOR ROTATING STORMS ALONG AND AHEAD OF WARM FRONT.
GENERALLY A HIGH SHEAR/LOW CAPE THREAT WITH WDSPRD CLOUDS AND PCPN
LIMITING INSTABILITY.
MIN TEMPS MAINLY LOW-MID 60S EVEN WITH WDSPRD RAIN.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 350 AM SUNDAY...BY MONDAY, THE UPPER TROUGH WILL SHIFT
EAST NEAR THE GREAT LAKES REGION WITH SEVERAL SHORTWAVES/
VORTICITY MAXIMA ROTATING AROUND THE BASE OF THE UPPER TROUGH. THE
SURFACE LOW WILL MOVE NORTHEAST INTO SOUTHEASTERN CANADA WITH THE
ATTENDANT COLD FRONT WELL NORTH OF THE REGION. THE BEST LIFT FROM
THE NORTHERN STREAM LIFTS WELL NORTH OF THE AREA WHILE THE
SOUTHERN STREAM JET REMAINS WELL SOUTHWEST OF EASTERN NC. THE BEST
MOISTURE ALSO LIFTS WELL NORTH OF EASTERN NC WITH FORECAST
SOUNDINGS INDICATING PWATS FALLING TO 1.20 INCHES MONDAY
AFTERNOON. GUIDANCE IS IN GOOD AGREEMENT WITH A SHORTWAVE/VORT MAX
MOVING THROUGH EASTERN NC MONDAY AFTERNOON/EVENING WHICH COULD
HELP SUPPORT OR ENHANCE ONGOING CONVECTION. 500 MB TEMPS FALL
FROM AROUND -11/-12 C SUNDAY TO -15/-16 C MONDAY AFTERNOON
INDICATING A FAVORABLE ENVIRONMENT FOR LARGE HAIL SHOULD STORMS
BECOME SEVERE. GIVEN SOUTHWESTERLY UNIDIRECTIONAL SHEAR, CAN ALSO
EXPECT A FEW SHOWERS/THUNDERSTORMS ALONG THE INLAND MOVING SEA-
BREEZE. AS DRY SLOTTING DEVELOPS MONDAY MORNING, CLOUD COVER WILL
DIMINISH ALLOWING EXCELLENT INSOLATION. INSTABILITY WILL BE
PLENTIFUL THOUGH THE ENVIRONMENT WILL A TRIGGER FOR CONVECTIVE
INITIATION, AND LACK VEERING LOW LEVEL WINDS. SPC MAINTAINS A
SLIGHT RISK FOR EASTERN NC THROUGH MONDAY EVENING/NIGHT. BIGGEST
THREAT WILL BE LARGE HAIL AND DAMAGING WIND GUSTS, THOUGH AN
ISOLATED TORNADO CANNOT BE RULED OUT.
INCREASED POPS TO CHANCE INLAND MONDAY AFTERNOON. HIGHS MONDAY
WILL BE IN THE LOW 80S INLAND AND MID 70S BEACHES.
MONDAY NIGHT/TUESDAY...COLD FRONT MOVES OFFSHORE LATE MONDAY NIGHT
AND EARLY TUESDAY MORNING WITH SLIGHTLY COOLER AND DRIER AIR
MOVING IN. TUESDAY`S HIGHS SHOULD BE IN THE MID 70S...BUT WITH
DEWPOINTS DOWN IN THE LOWER 50S BY AFTERNOON.
TUESDAY NIGHT/WEDNESDAY...HIGH PRESSURE BUILDS OVERHEAD WITH
MAINLY HIGH CLOUDS WEDNESDAY. COOL MORNING LOWS AROUND 50 REBOUND
TO AFTERNOON HIGHS IN THE MID 70S.
WEDNESDAY NIGHT/THURSDAY...ZONAL FLOW ALOFT CONTINUES AS A COLD
FRONT CROSSES THE REGION LATE THURSDAY. GUIDANCE IN MODEST
AGREEMENT FOR LIGHT SHOWERS/THUNDERSTORMS THURSDAY, THUS HAVE
INTRODUCED SLIGHT CHANCE POP WITH FRONTAL PASSAGE. ANOTHER COOL
MORNING THURSDAY WITH LOWS 50 TO 55...REBOUNDING INTO THE UPPER
70S THURSDAY AFTERNOON.
THURSDAY NIGHT/FRIDAY...DRY WEATHER BEHIND THE FRONT WITH SUNNY
COOLER WEATHER FOR FRIDAY. LOWS AGAIN IN THE 50 TO 55 DEGREE
RANGE WITH HIGHS UPPER 60S FAR NORTHEAST AND LOW 70S ELSEWHERE.
FRIDAY NIGHT/SATURDAY...ANOTHER SOUTHERN STREAM SYSTEM APPROACHES
LATE SATURDAY. HAVE INDICATED INCREASED CLOUD COVER AND A SMALL
CHANCE OF RAIN IN THE AFTERNOON.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 18Z MONDAY/...
AS OF 140 PM SUNDAY...VFR CONDITIONS WILL PERSIST FOR ANOTHER ONE
TO TWO HOURS...BEFORE CONDITIONS BEGIN TO DETERIORATE THIS
AFTERNOON. SE WINDS WILL CONTINUE THROUGH THIS EVENING AT 10 TO 15
KNOTS. WIDESPREAD SHOWERS WILL SPREAD FROM THE SW TO NE THIS
AFTERNOON WITH A SLIGHT CHANCE OF THUNDERSTORMS THROUGH LATE THIS
EVENING. GUIDANCE AND MODEL SOUNDING ARE SHOWING WIDESPREAD IFR
CONDITIONS FOR ALL TAF SITES SHORTLY AFTER 00Z. IFR CONDITIONS
WILL PERSIST THROUGH THE OVERNIGHT UNDER WIDESPREAD RAIN SHOWERS.
CONDITIONS WILL IMPROVE BY 12Z MONDAY AS RAIN SHOWERS TAPERS OFF
TO THE EAST. EXPECTING VFR CONDITIONS TO RETURN BY 15Z MONDAY
UNDER SCT CLOUDS.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 355 AM SUNDAY...PRECIPITATION DIMINISHES MONDAY BUT SOME
ISOLATED STRONG TO SEVERE TSTMS MAY BE POSSIBLE, ESPECIALLY KPGV
AND KISO, MONDAY AFTERNOON AND EVENING WHICH COULD PRODUCE SUB-VFR
AVIATION CONDITIONS. HIGH PRESSURE BUILDS IN ACROSS EASTERN NC
TUESDAY INTO WEDNESDAY YIELDING MOSTLY VFR CONDITIONS. A WEAK
FRONT WILL MOVE SOUTH INTO EASTERN NC THURSDAY BUT WITH LIMITED
MOISTURE SO EXPECT MOSTLY VFR CONDITIONS THURSDAY.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 115 PM SUNDAY...WINDS HAVE DROPPED A BIT FROM THIS MORNING
WITH GENERALLY E/NE WIND 10 TO 15 KNOTS WITH SOME GUSTS TO AROUND
21 KNOTS AT DIAMOND SHOALS. SEAS STILL 3 TO 5 FEET WITH LONG
PERIOD SWELLS OVER THE CENTRAL AND NORTHERN WATERS. WINDS BECOME
SE LATER TODAY AS WARM FRONT LIFTS NORTH. WINDS INCREASE TO 15 TO
20 KNOTS BY THIS EVENING. PRES GRAD WILL TIGHTEN TONIGHT WITH WARM
FRONT MOVING IN FROM SW...RESULTING IN WINDS BECOMING S-SW 20-25
KT. SEAS BUILDING TO 4-6 FT OUTER WATERS LATE TODAY AND PEAKING
6-8 FT LATE TONIGHT.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 355 AM SUNDAY...GUSTY S/SW WINDS WILL BUILD SEAS TO 7-8 FEET
MONDAY. SEAS WILL REMAIN ELEVATED INTO TUESDAY MORNING AND CURRENT
SCA FOR ALL COASTAL WATERS WILL REMAIN IN EFFECT UNTIL 12Z TUESDAY.
HIGH PRESSURE WILL BUILD OVER THE NC WATERS TUESDAY INTO WEDNESDAY
WITH WINDS SHIFTING MORE WESTERLY, 5-15 KT. SEAS WILL DIMINISH TO
2-4 FT TUESDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT WILL MOVE
SOUTH INTO THE NORTHERN WATERS THURSDAY AND SHIFT SOUTH OF THE
WATERS THURSDAY NIGHT. WINDS VEER NORTHWEST BEHIND THE FRONT BUT
REMAIN 5-15 KT WITH SEAS 2-4 FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 8 AM EDT
TUESDAY FOR AMZ150-152-154-156-158.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...DAG
AVIATION...DAG/BM
MARINE...CTC/JBM/DAG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
148 PM EDT SUN APR 19 2015
.SYNOPSIS...
A FRONTAL SYSTEM WILL BRING SHOWERS AND A FEW THUNDERSTORMS
THROUGH MONDAY. A FEW STORMS MAY BE STRONG TO SEVERE. DRY AND
SEASONABLE HIGH PRESSURE WILL BUILD INTO THE AREA TUESDAY AND
WEDNESDAY. WARMER TEMPERATURES ARE EXPECTED THURSDAY AHEAD OF
THE NEXT COLD FRONT. MUCH COOLER TEMPERATURES ARE POSSIBLE
LATE WEEK AND INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1244 PM SUNDAY...NO SIGNIFICANT CHANGES FOR THE EARLY
AFTERNOON UPDATE...WITH POP DISTRIBUTION RANGING FROM SCATTERED
TO LIKELY ACROSS THE AREA AND A SLIGHT CHANCE OF A THUNDERSTORM.
EXTENSIVE CLOUD COVER WILL LIMIT SURFACE BASED BUOYANCY BUT A
RAMPING UP IN PRECIPITABLE WATERS AS SEEN IN SATELLITE DATA WILL
LIKELY REMOVE ANY CONVECTIVE INHIBITION AND POP-UP SHOWERS COULD
OCCUR ANYWHERE NEAR SMALL OUTFLOWS...DIFFERENTIAL HEATING...AND
WEAK SEA BREEZE CONVERGENCE ZONES. A BROAD AREA OF PATCHY LIGHT
RAIN WILL SPREAD NE ACROSS THE AREA THROUGH THE AFTERNOON. THE
PREVIOUS DISCUSSION FOLLOWS.
ADJUSTMENTS WERE REQUIRED TO SCALE BACK TIMING AND COVERAGE OF
PRECIPITATION TODAY...BASED ON DECLINING NATURE OF SHOWERS
ASSOCIATED WITH AN APPROACHING WARM FRONTAL FEATURE. SEVERAL
SHOWERS WILL MAKE A RUN TOWARD THE NORTH COAST FROM THE
OCEAN...AND AREAS WEST OF I-95 APPEAR POISED TO RECEIVE A TENTH
OF AN INCH THROUGH MIDDAY...OTHERWISE PROSPECTS OF SOLID RAIN
MEASUREMENTS WERE DECREASED IN THE FORECAST AND THE GRIDDED
PRODUCTS THROUGH EARLY AFTERNOON. SOME HOPE REMAINS FOR BREAKS IN
THE CLOUD COVER TO OFFER LOW-LEVEL HEATING WHICH COULD INITIATE
CONVECTION WITH WEAK SEA BREEZE CONVERGENCE. BETTER RAIN CHANCES
APPEAR OVERNIGHT PER SEVERAL OF THE NEAR TERM MODELS. FORECAST FOR
TODAY NOW READS SCATTERED EXCEPT FAR WESTERN ZONES LIKELY. DESPITE
REDUCTION IN POPS AND TIMING...A FEW TSTMS COULD BECOME STRONG AND
SPC MAINTAINS MARGINAL RISK OVER NC AND SLIGHT RISK OVER PORTIONS
OF NE SC TODAY.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...INTERESTING START TO THE WORK WEEK AS A
SHORTWAVE EMBEDDED WITHIN A DEEPENING TROUGH WILL CREATE THE
POTENTIAL FOR STRONG THUNDERSTORMS ON MONDAY.
WARM FRONT WILL BE WELL NORTH OF THE AREA MONDAY MORNING...AND MOST
OF THE HEAVY RAINFALL ANTICIPATED SUNDAY NIGHT WILL BE
NORTH/OFFSHORE BY THE BEGINNING OF THE PERIOD. SOME RESIDUAL SHOWERS
MAY PERSIST ON THE COAST EARLY...BUT ACTUALLY EXPECT THE MORNING
HOURS TO BE DRY FOR THE MOST PART LOCALLY. THE COLUMN WILL DRY
CONSIDERABLY FROM SUNDAY AS THE BEST MOISTURE DEPARTS TO THE
NE...AND SOME SUBSIDENCE IS EXPECTED BEHIND AN EXITING SHORTWAVE.
THIS WILL LEAVE AT LEAST PARTIAL INSOLATION...AND AS WARM/MOIST
ADVECTION CONTINUES THE ATMOSPHERE WILL BECOME QUITE UNSTABLE MONDAY
AFTN/EVE. FORECAST MLCAPE VALUES RISE TOWARDS 2000 J/KG...WITH THE
SREF MEAN AROUND 1500 J/KG. AT THE SAME TIME...A SHORTWAVE WILL RIDE
THROUGH THE DEEPENING TROUGH SO PVA COMBINED WITH HEIGHT FALLS
/STEEPENING MID-LEVEL LAPSE RATES/ WILL DRIVE AN ENVIRONMENT
CONDUCIVE TO STRONG CONVECTION. ADDITIONALLY...LFQ OF A SUBTROPICAL
250MB JET WILL APPROACH FROM THE SW. HOWEVER...SURFACE FORCING IS
MOSTLY WEAK AND THE MID-LEVELS REMAIN QUITE DRY DURING THE MOST
UNSTABLE PART OF THE DAY. THIS SUGGESTS THAT ACTIVITY WILL BE
ISOLATED OR SCATTERED MONDAY AFTN/EVE...BUT ANY STORM WILL HAVE
THE POTENTIAL TO BECOME STRONG AND SPC HAS THE AREA IN A SLIGHT
RISK FOR MONDAY. DO NOT EXPECT WIDESPREAD STRONG/SEVERE
STORMS...AND ATTM THE BEST FOCUS MAY BE ALONG THE PIEDMONT TROUGH
AND WESTERN PORTIONS OF THE CWA.
COLD FRONT WILL APPROACH SLOWLY FROM THE NW DRIVEN BY THE DEEPENING
UPPER TROUGH...AND IS NOW SLATED FOR A CROSSING JUST BEFORE DAWN
TUESDAY. THIS FRONT WILL BE ACCOMPANIED BY MORE WIDESPREAD SHOWER
ACTIVITY...BUT NOT EXPECTING STRONG CONVECTION WITH ITS PASSAGE.
COLD ADVECTION LAGS THE FRONT CONSIDERABLY...SO WHILE TUESDAY WILL
BE DRY WITH MUCH MORE SUNSHINE AS HIGH PRESSURE BUILDS ACROSS THE
REGION...TEMPS WILL NOT BE SIGNIFICANTLY COOLER THAN MONDAY.
ON THE DISCUSSION OF TEMPERATURES...MONDAY WILL LIKELY BE WELL ABOVE
NORMAL WITH WIDESPREAD 80S AWAY FROM THE BEACHES ON STRONG WARM
ADVECTION AHEAD OF THE FRONT. A RELATIVELY WARM NIGHT EXPECTED
MONDAY NIGHT AS FROPA OCCURS LATE...AND LOWS WILL DROP ONLY INTO THE
LOW 60S. SLIGHTLY COOLER TUESDAY WITH HIGHS REACHING WELL INTO THE
70S TO NEAR 80...BEFORE COOL DRY HIGH PRESSURE ALLOWS FOR TEMPS TO
CRASH TO AROUND 50 TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 AM SUNDAY...MID-LEVELS EVOLVE INTO A DECIDEDLY WINTER-LIKE
APPEARANCE THROUGH THE EXTENDED WITH A LARGE VORTEX CUTOFF ACROSS
SOUTHEAST CANADA WHICH WILL SLOWLY DROP ACROSS NEW ENGLAND BY THE
WKND. INITIALLY THIS PRODUCES BENIGN AND SEASONABLE WEATHER ACROSS
THE CAROLINAS...AS THE FLOW BECOMES ZONAL BENEATH THE CUTOFF...SO
SURFACE HIGH PRESSURE WILL BECOME THE DOMINANT FEATURE WED/THU. THIS
HIGH WILL MOVE OFFSHORE THURSDAY AHEAD OF THE NEXT COLD
FRONT...DRIVEN BY A PIECE OF VORT ENERGY ROTATING AROUND THE LARGE
MID-LEVEL VORTEX. MID-LEVEL FLOW REMAINS W/NW HOWEVER...SO ALTHOUGH
PRECIP CHANCES INCREASE WITH THE COLD FRONT...SIGNIFICANT SHOWER
ACTIVITY IS NOT ANTICIPATED. THE BIGGER STORY COULD BE MUCH COOLER
TEMPS BEHIND THIS FRONT FRI/SAT THANKS TO 1000-500MB THICKNESSES
DROPPING TOWARDS -2 SD`S FROM CLIMO...AND HIGHS/LOWS BY SATURDAY
COULD FALL WELL BELOW NORMAL. A LOW PRESSURE SYSTEM MAY BEGIN TO
EMERGE FROM THE GULF COAST STATES AND MOVE TOWARDS THE AREA AT THE
END OF THE PERIOD...AND WILL MAINTAIN INHERITED LOW-CHC POP FOR
SATURDAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...SOME CONVECTION IS TRYING TO MOVE ONSHORE NEAR
ILM...OTHERWISE THE COASTAL TERMINALS MAY NOT SEE TOO MUCH ACTION
INITIALLY. MAINLY A EAST SOUTHEAST WIND THIS AFTERNOON. THIS
EVENING...THE HRRR IS STAYING FAIRLY CONSISTENT IN BRINGING IN AN
ORGANIZED LINE OF OF CONVECTION TO THE INLAND TERMINALS AROUND 23Z.
WILL LEAN HEAVILY ON THIS MODEL THROUGH THE EVENING HOURS. AFTER THE
CONVECTION MOVES THROUGH...EXPECT IFR CEILING THROUGH THE OVERNIGHT
HOURS...WITH SOME LIGHT FOG. MONDAY...IMPROVING CEILINGS AS THE DAY
WEARS ON WITH A GUSTY SOUTHWEST WIND. CONVECTION IS EXPECTED TO FIRE
AFTER THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...A COLD FRONT WILL PUSH THROUGH THE AREA MONDAY
NIGHT WITH SHOWERS POSSIBLE FOLLOWED BY MAINLY VFR CONDITIONS
TUESDAY AND WEDNESDAY. POSSIBLE SHOWERS THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1244 PM SUNDAY...LOW PRESSURE OVER THE MID-MISSISSIPPI
VALLEY WILL DEEPEN TODAY. THE INCREASING SOUTHERLY WIND AHEAD OF
THIS SYSTEM WILL DRAG A WARM FRONT THROUGH THE COASTAL CAROLINAS
THIS AFTERNOON. GENERALLY EASTERLY WINDS THIS MORNING WILL VEER
SOUTHEASTERLY THIS AFTERNOON...THEN SOUTHERLY TONIGHT. WINDS WILL
INCREASE BUT NOT EXCESSIVELY SO GIVEN THE PRETTY LARGE DISTANCE
FROM HERE BACK TO THE LOW...AND ALSO THE FACT THAT THE INCOMING
AIRMASS WILL BE SIGNIFICANTLY WARMER THAN THE OCEAN SURFACE
LEADING TO MOST OF THE WIND ENERGY RIDING UP AND OVER A COOL AND
STABLE LAYER OF AIR AT THE SURFACE.
WIDESPREAD SHOWERS AND EMBEDDED T-STORMS SHOULD AFFECT THE COASTAL
WATERS THIS AFTERNOON AND TONIGHT. REDUCED VISIBILITY IN HEAVY
RAINFALL AND ALSO OCCASIONAL LIGHTNING STRIKES WILL BE THE MOST
SIGNIFICANT IMPACTS. SEAS WILL GRADUALLY BUILD DUE TO THE ONSHORE
FLOW...WITH THE WORST CONDITIONS EXPECTED NORTH OF CAPE FEAR. THERE
IS A 4-6 HOUR WINDOW LATE THIS EVENING INTO EARLY MONDAY MORNING
WHERE A SMALL CRAFT ADVISORY MAY BE NEEDED NORTH OF CAPE FEAR DUE TO
6 FOOT SEAS...BUT GIVEN SOME REMAINING UNCERTAINTY ABOUT HOW LONG
SOUTHERLY WINDS BLOW BEFORE VEERING SOUTHWESTERLY AND WEAKENING...I
WILL DELAY RAISING THE ADVISORY JUST YET.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...COLD FRONT APPROACHING FROM THE WEST WILL
PINCH THE GRADIENT MONDAY...AND GUSTY SW WINDS WILL REACH 15-20
KTS WITH SLIGHTLY HIGHER GUSTS. THIS WILL PERSIST ALL OF MONDAY
SINCE THE COLD FRONT IS NOT EXPECTED TO CROSS OFFSHORE UNTIL FIRST
LIGHT TUESDAY...AND THUS A CHOPPY SEA STATE IS EXPECTED. WAVE
HEIGHTS WILL RISE TO 4-5 FT...AND A SCEC MAY BE NEEDED MUCH OF
MONDAY. WINDS WILL SHIFT QUICKLY TO THE W AND THEN NW BEHIND THE
FRONT TUESDAY MORNING...AND THEN SLOWLY DECREASE IN SPEED FROM
10-15 KTS...TO AROUND 5 KTS AS HIGH PRESSURE BUILDS TOWARDS THE
AREA REDUCING THE PRESSURE GRADIENT. SEAS WILL FALL INITIALLY ON
THE OFFSHORE WIND TO 2-4 FT...BEFORE DROPPING FURTHER TO 1-2 FT
TUESDAY NIGHT.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 300 AM SUNDAY...BROAD HIGH PRESSURE WILL SKIRT ACROSS THE
WATERS AND OFFSHORE WEDNESDAY...SO LIGHT AND VARIABLE WINDS WILL
GRADUALLY TRANSITION TO A SW DIRECTION WEDNESDAY NIGHT AS RETURN
FLOW DEVELOPS. THIS SW FLOW WILL PERSIST MOST OF THURSDAY BUT WITH
SPEEDS INCREASING TO 10-15 KTS AHEAD OF A COLD FRONT WHICH WILL
CROSS THE WATERS AT THE END OF THE PERIOD. WAVE HEIGHTS OF 1-2 FT
WILL BUILD SLOWLY ONCE THE WIND BECOMES PREDOMINANTLY FROM THE SW
LATE WEDNESDAY...AND THEN CONTINUE TO SLOWLY RISE THURSDAY TO 3-4
FT BEFORE THE COLD FRONTAL PASSAGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...DL
MARINE...TRA/JDW
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
117 PM EDT SUN APR 19 2015
.SYNOPSIS...
HIGH PRESSURE EXTENDING OVER THE AREA FROM THE NORTH WILL SHIFT
OFFSHORE TODAY. A WARM FRONT WILL LIFT NORTHEAST ACROSS THE AREA
TONIGHT AS LOW PRESSURE MOVES INTO THE OHIO VALLEY. A COLD FRONT
WILL MOVE THROUGH FROM THE WEST EARLY TUESDAY FOLLOWED BY HIGH
PRESSURE WEDNESDAY. ANOTHER COLD FRONT WILL MOVE IN FROM THE
NORTHWEST THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 110 PM SUNDAY...FORECAST PRETTY MUCH ON TRACK WITH A
MODERATE TO HEAVY SHOWERS DRIFTING IN FROM THE OCEAN AND THE
LEADING EDGE OF THE WIDESPREAD RAIN SHIELD IS MOVING INTO SOUTH
CENTRAL NORTH CAROLINA. GENERALLY FOLLOWED THE 3KM HRRR WHICH IS
DOING A GOOD JOB OF DEPICTING THE RAINFALL. NO CHANGES THROUGH THE
AFTERNOON AS RAIN BECOMES WIDESPREAD AND STEADY. CONVECTIVE
DEVELOPMENT POTENTIAL SEEMS LIMITED BASED ON CURRENT PARAMETERS AS
BEST INSTABILITY OCCURRING MUCH FURTHER SOUTHWEST ACROSS
GEORGIA...ALABAMA AND THE FLORIDA PANHANDLE. NO CHANGE TO
TEMPERATURE FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 400 AM SUNDAY...LATEST GDNC CONTINUES TO INDICATE WET
CONDITIONS TONIGHT AND INCREASED POPS TO 100% ALL ZONES. DIFFLUENT
UPR FLOW AHEAD OF UPR TROF LIFTING OUT OF SRN PLAINS WILL INDUCE
LARGE SCALE ASCENT ACROSS AREA ALONG WITH DEEP MSTR PLUME FROM
GULFMEX. SFC WARM FRONT WILL APPROACH FROM SW AS DEVELOPING LOW
PRES MOVES INTO WRN OH VLY. WDSPRD SHOWERS AND PSBLY SCT TSTMS
EXPECTED TO GRADUALLY SPREAD SW TO NE ACROSS ERN NC OVERNIGHT. QPF
LOWERED SLIGHTLY BASED ON HPC AND LATEST MODEL BLEND...BUT MOST
AREAS STILL SEEING 1/2 TO 1 INCH.
PER NEAR-TERM...MARGINAL SVR THREAT FOR SW SECTIONS WITH SOME
POTENTIAL FOR ROTATING STORMS ALONG AND AHEAD OF WARM FRONT.
GENERALLY A HIGH SHEAR/LOW CAPE THREAT WITH WDSPRD CLOUDS AND PCPN
LIMITING INSTABILITY.
MIN TEMPS MAINLY LOW-MID 60S EVEN WITH WDSPRD RAIN.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 350 AM SUNDAY...BY MONDAY, THE UPPER TROUGH WILL SHIFT
EAST NEAR THE GREAT LAKES REGION WITH SEVERAL SHORTWAVES/
VORTICITY MAXIMA ROTATING AROUND THE BASE OF THE UPPER TROUGH. THE
SURFACE LOW WILL MOVE NORTHEAST INTO SOUTHEASTERN CANADA WITH THE
ATTENDANT COLD FRONT WELL NORTH OF THE REGION. THE BEST LIFT FROM
THE NORTHERN STREAM LIFTS WELL NORTH OF THE AREA WHILE THE
SOUTHERN STREAM JET REMAINS WELL SOUTHWEST OF EASTERN NC. THE BEST
MOISTURE ALSO LIFTS WELL NORTH OF EASTERN NC WITH FORECAST
SOUNDINGS INDICATING PWATS FALLING TO 1.20 INCHES MONDAY
AFTERNOON. GUIDANCE IS IN GOOD AGREEMENT WITH A SHORTWAVE/VORT MAX
MOVING THROUGH EASTERN NC MONDAY AFTERNOON/EVENING WHICH COULD
HELP SUPPORT OR ENHANCE ONGOING CONVECTION. 500 MB TEMPS FALL
FROM AROUND -11/-12 C SUNDAY TO -15/-16 C MONDAY AFTERNOON
INDICATING A FAVORABLE ENVIRONMENT FOR LARGE HAIL SHOULD STORMS
BECOME SEVERE. GIVEN SOUTHWESTERLY UNIDIRECTIONAL SHEAR, CAN ALSO
EXPECT A FEW SHOWERS/THUNDERSTORMS ALONG THE INLAND MOVING SEA-
BREEZE. AS DRY SLOTTING DEVELOPS MONDAY MORNING, CLOUD COVER WILL
DIMINISH ALLOWING EXCELLENT INSOLATION. INSTABILITY WILL BE
PLENTIFUL THOUGH THE ENVIRONMENT WILL A TRIGGER FOR CONVECTIVE
INITIATION, AND LACK VEERING LOW LEVEL WINDS. SPC MAINTAINS A
SLIGHT RISK FOR EASTERN NC THROUGH MONDAY EVENING/NIGHT. BIGGEST
THREAT WILL BE LARGE HAIL AND DAMAGING WIND GUSTS, THOUGH AN
ISOLATED TORNADO CANNOT BE RULED OUT.
INCREASED POPS TO CHANCE INLAND MONDAY AFTERNOON. HIGHS MONDAY
WILL BE IN THE LOW 80S INLAND AND MID 70S BEACHES.
MONDAY NIGHT/TUESDAY...COLD FRONT MOVES OFFSHORE LATE MONDAY NIGHT
AND EARLY TUESDAY MORNING WITH SLIGHTLY COOLER AND DRIER AIR
MOVING IN. TUESDAY`S HIGHS SHOULD BE IN THE MID 70S...BUT WITH
DEWPOINTS DOWN IN THE LOWER 50S BY AFTERNOON.
TUESDAY NIGHT/WEDNESDAY...HIGH PRESSURE BUILDS OVERHEAD WITH
MAINLY HIGH CLOUDS WEDNESDAY. COOL MORNING LOWS AROUND 50 REBOUND
TO AFTERNOON HIGHS IN THE MID 70S.
WEDNESDAY NIGHT/THURSDAY...ZONAL FLOW ALOFT CONTINUES AS A COLD
FRONT CROSSES THE REGION LATE THURSDAY. GUIDANCE IN MODEST
AGREEMENT FOR LIGHT SHOWERS/THUNDERSTORMS THURSDAY, THUS HAVE
INTRODUCED SLIGHT CHANCE POP WITH FRONTAL PASSAGE. ANOTHER COOL
MORNING THURSDAY WITH LOWS 50 TO 55...REBOUNDING INTO THE UPPER
70S THURSDAY AFTERNOON.
THURSDAY NIGHT/FRIDAY...DRY WEATHER BEHIND THE FRONT WITH SUNNY
COOLER WEATHER FOR FRIDAY. LOWS AGAIN IN THE 50 TO 55 DEGREE
RANGE WITH HIGHS UPPER 60S FAR NORTHEAST AND LOW 70S ELSEWHERE.
FRIDAY NIGHT/SATURDAY...ANOTHER SOUTHERN STREAM SYSTEM APPROACHES
LATE SATURDAY. HAVE INDICATED INCREASED CLOUD COVER AND A SMALL
CHANCE OF RAIN IN THE AFTERNOON.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH 12Z MONDAY/...
AS OF 700 AM SUNDAY...LIFT STRATUS CIGS DEVELOPED ALL TAF SITES
10-11Z WITH LIFR VSBYS AS WELL AT KPGV AND KISO. CONDITIONS
EXPECTED TO LIFT TO VFR BY AROUND 13Z. VFR PERSISTING INTO EARLY
AFTN...THEN CONDITIONS DETERIORATING. WIDESPREAD SHOWERS/ISOLD
TSTMS EXPECTED TO DEVELOP AND SPREAD SW TO NE ACROSS AREA THIS
AFTN INTO EARLY EVENING...WITH WDSPRD IFR CIGS LIKELY ALL TAF
SITES BY 00Z AND PERSISTING OVERNIGHT WITH VSBYS 3-5 SM IN SHRA.
LIGHT WINDS THIS MORNING WILL BECOME SE 10-15 KT THIS AFTN INTO
EVENING.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 355 AM SUNDAY...PRECIPITATION DIMINISHES MONDAY BUT SOME
ISOLATED STRONG TO SEVERE TSTMS MAY BE POSSIBLE, ESPECIALLY KPGV
AND KISO, MONDAY AFTERNOON AND EVENING WHICH COULD PRODUCE SUB-VFR
AVIATION CONDITIONS. HIGH PRESSURE BUILDS IN ACROSS EASTERN NC
TUESDAY INTO WEDNESDAY YIELDING MOSTLY VFR CONDITIONS. A WEAK
FRONT WILL MOVE SOUTH INTO EASTERN NC THURSDAY BUT WITH LIMITED
MOISTURE SO EXPECT MOSTLY VFR CONDITIONS THURSDAY.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 115 PM SUNDAY...WINDS HAVE DROPPED A BIT FROM THIS MORNING
WITH GENERALLY E/NE WIND 10 TO 15 KNOTS WITH SOME GUSTS TO AROUND
21 KNOTS AT DIAMOND SHOALS. SEAS STILL 3 TO 5 FEET WITH LONG
PERIOD SWELLS OVER THE CENTRAL AND NORTHERN WATERS. WINDS BECOME
SE LATER TODAY AS WARM FRONT LIFTS NORTH. WINDS INCREASE TO 15 TO
20 KNOTS BY THIS EVENING. PRES GRAD WILL TIGHTEN TONIGHT WITH WARM
FRONT MOVING IN FROM SW...RESULTING IN WINDS BECOMING S-SW 20-25
KT. SEAS BUILDING TO 4-6 FT OUTER WATERS LATE TODAY AND PEAKING
6-8 FT LATE TONIGHT.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 355 AM SUNDAY...GUSTY S/SW WINDS WILL BUILD SEAS TO 7-8 FEET
MONDAY. SEAS WILL REMAIN ELEVATED INTO TUESDAY MORNING AND CURRENT
SCA FOR ALL COASTAL WATERS WILL REMAIN IN EFFECT UNTIL 12Z TUESDAY.
HIGH PRESSURE WILL BUILD OVER THE NC WATERS TUESDAY INTO WEDNESDAY
WITH WINDS SHIFTING MORE WESTERLY, 5-15 KT. SEAS WILL DIMINISH TO
2-4 FT TUESDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT WILL MOVE
SOUTH INTO THE NORTHERN WATERS THURSDAY AND SHIFT SOUTH OF THE
WATERS THURSDAY NIGHT. WINDS VEER NORTHWEST BEHIND THE FRONT BUT
REMAIN 5-15 KT WITH SEAS 2-4 FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 8 AM EDT
TUESDAY FOR AMZ150-152-154-156-158.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...DAG
AVIATION...JBM/DAG
MARINE...CTC/JBM/DAG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1203 PM CDT SUN APR 19 2015
.UPDATE...
ISSUED AT 1202 PM CDT SUN APR 19 2015
QUICK UPDATE TO ADD A MENTION OF ISOLATED THUNDERSTORMS THIS
AFTERNOON WITH SMALL HAIL BEING REPORTED ACROSS MUCH OF WESTERN
AND CENTRAL NORTH DAKOTA WITH SHALLOW CONVECTION ASSOCIATED WITH COOL
TEMPERATURES ALOFT.
UPDATE ISSUED AT 929 AM CDT SUN APR 19 2015
THE FORECAST FOR THE REMAINDER OF TODAY IS ON TRACK WITH THE
STRATUS FIELD OVERTAKING WESTERN AND CENTRAL NORTH DAKOTA EXPECTED
TO SLOWLY SCATTER WITH DIURNAL HEATING WITH RAIN SHOWER COVERAGE
INCREASING THROUGH THE AFTERNOON. THIS IS IN LINE WITH THE 12-13
UTC HRRR ITERATIONS.
UPDATE ISSUED AT 629 AM CDT SUN APR 19 2015
INITIAL BATCH OF WIDESPREAD RAIN CONTINUES TO PUSH OFF TO THE
EAST...THOUGH SECONDARY ROUND OF SCATTERED WRAP AROUND SHOWERS ARE
STARTING TO DEVELOP AND WORK INTO FAR NORTHWEST NORTH DAKOTA. HAVE
ADJUSTED POPS TO ACCOUNT FOR THIS. HAVE ALSO INCREASED CLOUD COVER
MAINLY OVER THE WEST AS CLOUDS CONTINUE TO STREAM IN BEHIND THE
LOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT SUN APR 19 2015
CONTINUED CHANCES FOR RAIN AND WINDY CONDITIONS THROUGH
SUNDAY...HIGHLIGHT THE SHORT TERM.
AN UPPER LEVEL TROUGH OVER THE NORTHERN PLAINS WILL CONTINUE TO
PROVIDE AMPLE MOISTURE AND INSTABILITY...PROLONGING CHANCES FOR
WIDESPREAD SHOWERS IN CENTRAL AND EASTERN AREAS OF THE STATE THROUGH
THE DAY. ADDITIONALLY...TEMPERATURES SLIGHTLY BELOW AVERAGE AND
STRONG NORTHWEST WINDS WILL ACCOMPANY THE DEEPENING TROUGH. THE
CURRENT 00Z MODEL SUITE PROVIDES GOOD AGREEMENT ON THE UPPER LEVEL
TROUGH DIGGING AND SLOWLY MOVING EASTWARD...PUSHING OVER
MINNESOTA/EASTERN MANITOBA AND CLOSING OFF BY 12Z MONDAY. NORTH
CENTRAL NORTH DAKOTA INTO THE JAMES RIVER VALLEY HAVE THE
POTENTIAL FOR A FEW SNOW FLAKES EARLY MONDAY MORNING...AS COLD AIR
FILTERING SOUTHWARD FROM CANADA IS EXPECTED TO DROP OVERNIGHT LOWS
TO JUST BELOW FREEZING.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 400 AM CDT SUN APR 19 2015
UPPER LOW WILL WORK ALONG THE MINNESOTA/ONTARIO BORDER ON MONDAY.
THIS SHOULD KEEP PRECIPITATION TO THE EAST OF OUR AREA THROUGH THE
DAY...THOUGH GUSTY NORTHWEST WINDS WILL CONTINUE IN THE WAKE OF
THE SYSTEM. A FAST MOVING WAVE WILL MOVE IN BEHIND THE SYSTEM LATE
TUESDAY NIGHT INTO EARLY WEDNESDAY WHICH MAY BRING A LITTLE LIGHT
PRECIPITATION TO CENTRAL NORTH DAKOTA...BUT WILL KEEP POPS LOW
WITH LACK OF MUCH MOISTURE TO WORK WITH. QUIET AND COOL CONDITIONS
ARE THEN EXPECTED WITH RIDGING TO THE WEST AND NORTHWESTERLY FLOW
OVER OUR AREA. MODELS START TO DISAGREE WITH THE POSITION OF THE
RIDGE AND WHETHER A FEW UPPER WAVES WILL MAKE IT THROUGH THE AREA
TOWARDS THE END OF THE WEEK. THEREFORE...WILL KEEP ANY
PRECIPITATION CHANCES ON THE LOW SIDE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1202 PM CDT SUN APR 19 2015
MVFR/VFR STRATUS THIS MORNING IS EXPECTED TO SLOWLY LIFT AND
SCATTER INTO THE AFTERNOON WITH RAIN SHOWER COVERAGE ALSO
INCREASING INTO THE AFTERNOON. ISOLATED THUNDERSTORMS WITH SMALL
HAIL ARE POSSIBLE. STRONG NORTHWEST WIND GUSTS OF 30-35 KTS ARE
ALSO FORECAST ACROSS WESTERN AND CENTRAL NORTH DAKOTA TODAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...AC
LONG TERM...JJS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1221 PM EDT SUN APR 19 2015
.SYNOPSIS...
A WARM FRONT AND UPPER LEVEL DISTURBANCE APPROACHING FROM THE
TENNESSEE VALLEY WILL BRING A SOAKING RAIN TO THE REGION TONIGHT
AND EARLY MONDAY. ADDITIONAL SHOWERS AND SCATTERED THUNDERSTORMS
WILL ACCOMPANY A COLD FRONT AS IT PUSHES EAST ACROSS THE STATE
MONDAY AFTERNOON AND EVENING. A LARGE UPPER LEVEL LOW WILL SET UP
OVER ONTARIO AND QUEBEC FOR THE MIDDLE AND LATTER PART OF THE
WEEK...USHERING IN UNSEASONABLY COOL AIR WHICH WILL LAST INTO THE
WEEKEND OR LONGER.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
EARLIER...THICKER CIRROSTRATUS HAS THINNED ACROSS MUCH OF CENTRAL
AND NEPA...BUT THIS WINDOW WILL BE FLEETING AS THICKENING MID AND
HIGH CLOUDS STREAM IN QUICKLY FROM THE SW DURING THE MID TO LATE
AFTERNOON HOURS...WITH THE ONSET OF RAIN 4-6 HOURS AFTERWARD.
THE DECENT AMOUNT OF SUNSHINE HAS HELPED TO BOOST TEMPS A FEW-SVRL
DEG F ABOVE FCST HOURLY VALUES DURING THE LATE MORNING...BUT NOT
MUCH ABOVE ACTUAL FCST HIGHS FOR TODAY. SOME MAX TEMP TWEAKS WERE
DONE TO THE GRIDDED FCST DATABASE.
OVERALL...A RATHER NICE EARLY SPRING AFTERNOON...WITH A LIGHT TO
MODERATE SERLY BREEZE AND HIGH TEMPS RANGING FROM AROUND 60F
ACROSS THE HIGHER TERRAIN OF THE NORTH AND WEST...TO THE UPPER 60S
THROUGHOUT MUCH OF THE SUSQ VALLEY.
LATEST MODEL TIMING OF THE LEADING...NE EDGE OF RAIN /INCLUDING
THE 12Z NAM...09Z SREF...AND LATEST 14Z HRRR RUN/ SUGGESTS THE
BULK OF THE REGION WILL BE DRY FOR MUCH OF THE DAY.
FAR SOUTHWESTERN AREAS WILL LIKELY SEE SHOWERS BEGIN AROUND 5 PM
/21Z/...WHILE THE ONSET OF RAIN/SHOWERS MOVES TO NEAR A KBFD...TO
KUNV AND KMRB LINE AROUND 01Z MONDAY...THEN ACROSS THE SUSQ VALLEY
BETWEEN 03Z-05Z MONDAY.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH MONDAY NIGHT/...
LITTLE TO NO CHANGE WAS NECESSARY FROM THE PREVIOUS FEW FORECAST
CYCLES FOR THIS SHORT TERM PERIOD. THE MAIN CHANGE WAS TO FURTHER
REFINE THE TIMING AND TO SHOW A SLIGHTLY MORE-OBVIOUS 4-6HR BREAK
BETWEEN THE OVERNIGHT/MORNING RAIN AND THE STORMS IN THE
AFTERNOON/EVENING. MINS WILL BE HELD UP AS THE WINDS WILL BE
BREEZY. USUALLY...CENTRAL PA DOES NOT GET STRONG WIND GUSTS DURING
STABLE SERLY FLOW RAIN EVENTS. SO THOUGHTS OF A WIND ADVY WERE
DISCOUNTED RATHER EARLY IN THE FORECAST PROCESS TONIGHT.
HOWEVER...THE STRONG LOW AND MID LEVEL FLOW WILL BUMP THE PWATS
INTO THE 1-1.5 INCH RANGE TONIGHT AND MONDAY. THUS...RAIN COULD BE
HEAVY AT TIMES. WITH THE ADDITIONAL TSRA MON PM...THE
QPF REACHES BETWEEN 0.75 AND 1.25 INCHES OVER A LARGE PORTION OF
THE AREA. BUT THE STREAM FLOWS ARE REALLY LOW AND NO THUNDER
TONIGHT SHOULD TRANSLATE INTO NO FLOOD WORRIES OTHER THAN SOME
PONDING OF WATER ON ROADS AND A FEW SMALL CREEKS AT BANKFULL.
THINGS ARE GROWING NICELY NOW IN THE SE AND EVEN LOCALLY IN HAPPY
VALLEY WHICH SHOULD TAKE UP PLENTY OF WATER COMPARED TO JUST TWO
WEEKS AGO. SPC HAS PLACED ALL OF THE AREA INTO MRGL RISK AND
BROUGHT THE DAY2 SLGT RISK INTO SRN PA...RIGHTFULLY SO. THE BREAK
AND ASSOCIATED BREAKS IN THE CLOUDS/WARM SECTOR ON MONDAY WILL
LEAD TO GOOD HEATING AND THE FRONT/FORCING COMES THROUGH AT AN
OPPORTUNE TIME TO GRAB THE MAX CAPES AND MIN STABILITY. CAPES MAY
BE AROUND 1500J/KG AND LI/S DROP TO -3 TO -5. WIND PROFILES ARE
MAINLY MULTI-CELLULAR - BUT WITH THE WARM FRONT LIKELY CUTTING
THROUGH THE AREA AT THE TIME...WILL NEED TO KEEP AN EYE OUT FOR
ROTATING STORMS - ESPECIALLY IF THEY OCCUR ON OR NEAR LLVL
BOUNDARIES.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
BEHIND THE COLD FRONT MIDWEEK...THE UPPER LOW HANGS AROUND S
CANADA/NEW ENGLAND FOR SEVERAL DAYS KEEPING FAIRLY BRISK W/NW FLOW
ACROSS PA. THIS WILL BRING A STEADY STREAM OF COLDER AIR AS TEMPS
SLOWLY SLIP A BIT LOWER EACH DAY WITH BELOW NORMAL READINGS FOR A
SEVERAL DAY PERIOD LINGERING INTO NEXT WEEKEND. PROXIMITY OF
UPPER LOW WILL ALSO KEEP MENTION OF SCT SHOWERS IN THE FORECAST...
MAINLY DURING THE DAYTIME HOURS. WEDNESDAY MAY HOLD A FAST-MOVING
SHORT-WAVE WHICH COULD PRODUCE WHITE PRECIP - BUT DURING THE
MIDDLE OF THE DAY.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL PREVAIL MUCH OF THE DAY...BUT RAPIDLY
DETERIORATE FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT
RESTRICTIONS TO REACH THE FIRST CENTRAL PENNSYLVANIA AIRFIELDS
AROUND 00Z MONDAY /KJST/.
TIGHTENING GRADIENT LATER TODAY AND TONIGHT AHEAD OF AN
APPROACHING COLD FRONT WILL PRODUCE GUSTY WINDS...AND LOW LEVEL
WIND SHEAR CONDITIONS. THESE HAVE NOW BEEN ADDED TO ALL TAFS
STARTING BETWEEN 00 AND 04Z.
RAIN AND WIDESPREAD IFR TO LIFR TONIGHT INTO MONDAY...BEFORE THE
PRECIPITATION BECOMES MORE SHOWERY WITH THE APPROACH OF THE FRONT.
THIS COLD FRONT WILL ALSO INTRODUCE THE CHANCE OF THUNDERSTORMS
MONDAY TO THE ENTIRE REGION.
OUTLOOK...
MON...WIDESPREAD RESTRICTIONS IN RAIN EARLY...SOME IMPROVEMENT IN
THE AFTERNOON...BUT TSRA POSSIBLE.
TUE- THU...UNSETTLED WITH NW FLOW EACH DAY...WITH AREAS OF
RESTRICTED CIGS/VSBYS IN SHRA IN THE WESTERN AND NORTHERN
MOUNTAINS...SPOTTY RESTRICTIONS IN MORE SCATTERED SHRA IN CENTRAL
MOUNTAINS...AND MAINLY VFR IN THE EAST AND SOUTHEAST.
&&
.FIRE WEATHER...
SFC WIND FROM THE SOUTHEAST WILL BE 10-15 KTS WITH GUSTS AROUND
20KT ACROSS THE HIGHER TERRAIN OF SOUTHERN AND WESTERN PENN THIS
AFTERNOON...WHILE THE WIND STAYS A BIT LIGHTER ACROSS THE NE HALF
OF THE STATE - WHERE REL HUMIDITY IS EXPECTED TO DIP TO/STAY BELOW
30 PERCENT FOR THE REST OF THE AFTERNOON.
GUSTS OF 15 TO 20 MPH ARE POSSIBLE IN THE NORTHEAST BY LATE
AFTERNOON.
BUT THE GUSTS OVER 20MPH WILL ONLY MATCH UP WITH THE LOW RH/S FOR
AN HOUR OR TWO AT THE MOST AND ONLY IN A SMALL PORTION OF THE
NORTHERN MOUNTAINS. THEREFORE...PLAN IS AT THIS POINT - NOT TO
ISSUE A RED FLAG WARNING.
A SIGNIFICANT RAINFALL IS EXPECTED STARTING THIS EVENING AND
LASTING UNTIL A COLD FRONT PUSHES THROUGH ON MONDAY AFTERNOON AND
EVENING. COOLER TEMPERATURES FOR THE REST OF THE WEEK WILL LIKELY
LEAD TO HIGHER RH/S AND KEEP FIRE WEATHER CONDITIONS BELOW
CRITICAL.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...CERU/RXR
AVIATION...JUNG
FIRE WEATHER...LAMBERT
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
200 PM CDT SUN APR 19 2015
.DISCUSSION...SURFACE MAP AT 18Z SHOWS A 1000 MB LOW CENTERED OVER
SOUTHERN ILLINOIS, WITH A WARM FROM SITUATED TO OUR NORTH, A
COLD FRONT STILL WEST OF THE MISSISSIPPI RIVER, AND A PRE-FRONTAL
TROUGH JUST NOW CROSSING THE TENNESSEE RIVER THAT IS PROVIDING THE
FOCUS FOR A DEVELOPING LINE OF CONVECTION. SATELLITE IMAGERY IS
STARTING TO SHOW SOME BREAKS IN THE CLOUDS, ESPECIALLY WEST OF
NASHVILLE. LAPS SOUNDING FOR BNA AT 18Z SHOWS WEAK INSTABILITY,
WITH A LIFTED INDEX OF -3.3 AND A CAPE OF 962 J/KG. ATMOSPHERE
REMAINS SUFFICIENTLY MOIST, WITH PRECIPITABLE WATER OF 1.44 INCHES
AND A K-INDEX OF 34. LATEST HRRR SHOWS SCATTERED CELLS ACROSS
MIDDLE TENNESSEE UNTIL A MORE ORGANIZED LINE OF CONVECTION COMES
THROUGH WITH THE COLD FRONT BETWEEN 04Z AND 09Z. GIVEN THE TIMING
OF THE FRONT, THE POTENTIAL FOR WIDESPREAD SEVERE STORMS APPEARS
LOW, ALTHOUGH MIDDLE TENNESSEE DOES REMAIN UNDER A SLIGHT RISK OF
SEVERE WEATHER TODAY AND TONIGHT, SO ISOLATED CASES OF SEVERE
ACTIVITY ARE STILL POSSIBLE. AFTER A FEW LINGERING SHOWERS ON
MONDAY, LOOK FOR A BRIEF RESPITE ON TUESDAY BEFORE THE NEXT COLD
FRONT DROPS SOUTHWARD THROUGH MIDDLE TENNESSEE WEDNESDAY AND
THURSDAY. GIVEN THAT THE UPPER FLOW ACROSS THE REGION WILL REMAIN
EITHER CYCLONIC OR ZONAL, WARM ADVECTION WILL BE HARD TO COME BY,
AND SO TEMPERATURES DURING THE NEXT 7 DAYS WILL REMAIN AT OR BELOW
NORMAL.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 60 67 43 72 / 50 40 10 10
CLARKSVILLE 57 66 41 71 / 50 40 05 10
CROSSVILLE 58 62 42 63 / 50 60 20 10
COLUMBIA 59 68 43 73 / 60 30 10 10
LAWRENCEBURG 57 67 43 72 / 60 20 10 10
WAVERLY 57 68 42 72 / 60 30 05 10
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ROSE
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
412 PM EDT SUN APR 19 2015
.SYNOPSIS...
LOW PRESSURE OVER WESTERN KENTUCKY WITH A WARM FRONT EXTENDING EAST
AND COLD FRONT TRAILING SOUTHWARD FROM THE LOW WILL LIFT NORTHEAST
TONIGHT INTO MONDAY. A COLD FRONT CROSSES THE REGION ON
MONDAY...THEN HIGH PRESSURE BUILDS IN FOR TUESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 333 PM EDT SUNDAY...
FLOOD WATCHES REMAIN IN EFFECT INTO TONIGHT.
A WARM FRONT TO OUR SOUTH WILL LIFT NORTH THIS EVENING AND CROSS THE
FORECAST AREA TONIGHT. DEEPER MOISTURE AND HIGHER PWATS WILL
INCREASE IN THE WARM ADVECTION WITH THE NORTHWARD ADVANCE OF THE
FRONT. THE REGIONAL RADAR IMAGE SHOWED WIDESPREAD CONVECTION ACROSS
THE MID ATLANTIC REGION SOUTHWARD TO THE SOUTHEAST US. THERE ARE
SOME CONCERNS OF STRONG CONVECTION ACROSS GEORGIA THIS AFTERNOON MAY
TAKE SOME OF THE MOISTURE AWAY FROM OUR AREA. OUR LOCAL RNK
WRFARW...HIRESW-ARW...NAM AND GFS WAIT UNTIL AFTER 00Z BEFORE
BRINGING IN HEAVIER CONVECTION THIS EVENING...WHILE HRRR AND ECMWF
ARE A LITTLE FASTER WITH TIMING. THE HRRR AND HIRESW-ARW LIFTS THE
PRECIPITATION NORTHEAST WITH MOST OF RAIN PULLING OUT BY 06-08Z.
USED A BLEND OF HRRR AND NAM FOR POPS...TAPERING POPS BACK AFTER 06Z
TONIGHT INTO MONDAY MORNING.
NOT EXPECTING ANY STRONG THUNDERSTORMS THIS AFTERNOON INTO TONIGHT
WITH CLOUD COVER HINDERING INSTABILITIES. HOWEVER...THE LOW LEVEL
JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL RESULT IN
STRONG UPSLOPE AND ISENTROPIC LIFT. THE STRONG WINDS THROUGH A
DEEP LAYER WILL PROVIDE LARGE HELICITY VALUES LATE THIS AFTERNOON
INTO THIS EVENING. THE DAY ONE CONVECTIVE OUTLOOK (SWODY1) PLACED
A MARGINAL (5 PERCENT CHANCE OF WIND) ACROSS SOUTHWEST PORTION OF
CWA. PLAYED LOW TEMPERATURES CLOSE TO ADJMAV WITH READINGS FROM
THE UPPER 40S IN THE NORTHWEST MOUNTAINS TO AROUND 60 DEGREES IN
THE PIEDMONT.
A WARM...MOIST AND UNSTABLE AIRMASS EXPECTED MONDAY. THE ATMOSPHERE
WILL DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT WITH SHOWERS
AND THUNDERSTORMS DEVELOPING MONDAY. INITIALLY CUT BACK POPS CLOSER
TO NAM FOR MONDAY MORNING...THEN INCREASED TO LIKELY BY MONDAY
AFTERNOON. SPC CONTINUES OUR SLIGHT RISK FOR MONDAY ACROSS MOST OF
OUR CWA. THIS IS SUPPORTED BY THE DYNAMIC ENVIRONMENT WITH HEALTHY
SHEAR AND DECENT CAPES AROUND 2K. IT WILL ALSO BE QUITE BREEZY WITH
EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER.
THE FRONT SHOULD BE CLEARING MONDAY NIGHT. HIGH TEMPERATURES MONDAY
WILL RANGE FROM THE MID 60S IN THE MOUNTAINS TO THE LOWER 80S IN THE
PIEDMONT.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 345 PM EDT SUNDAY...
TAIL END OF COLD FRONT AND ASSOCIATED CONVECTION WILL BE EXITING
THE AREA JUST AFT 00Z. HOWEVER...A BROAD UPPER TROUGH...ALMOST
WINTERLIKE PATTERN CONTINUES TO EVOLVE AND DEEPEN ACROSS THE
GREAT LAKES WITH NUMEROUS SPOKES OF PVA/SHORT WAVES REMAINING
UPSTREAM. THIS LEAVES THE REGION...ESPECIALLY THE MOUNTAINS...WITH
A VERY UNSETTLED PATTERN. AT A MINIMUM...EXPECT VARIABLE
CLOUDINESS. TIMING OF EMBEDDED DISTURBANCES WILL BE THE KEY TO THE
TIMES FOR THE BETTER CHANCES OF SHOWERS. FOR SEVERAL DAYS...THE
GFS HAS INSISTED ON A SIGNIFICANT DISTURBANCE MOVING THROUGH THE
REGION WED WITH WIDESPREAD -SHRA AS A RESULT. THE OTHER MODELS
REMAIN LACKLUSTER WITH THIS FEATURE...BUT DO SUGGEST AT LEAST SOME
SMALL CHANCE WITHIN THIS TIME FRAME. GIVEN THE UNSETTLED NATURE OF
THE PATTERN WITH UPSLOPE FLOW AND VERY DIFFICULT TO TIME UPPER
DISTURBANCES...CANNOT REALLY DROP POPS AT ANY TIME. BEST FOCUS
THROUGH THE PERIOD WILL REMAIN WEST OF THE BLUE RIDGE...AND
ESPECIALLY ACROSS THE MOUNTAINS OF WV/FAR SW VA. IN
ADDITION...ENOUGH INSTABILITY SUGGESTED WITH COLD AIR ALOFT...TO
INTRODUCE ISOLD TSRA WITH THE WED DISTURBANCE AS WELL.
850MB TEMPS DROP TO NEAR 0C ACROSS THE NORTHERN PART OF THE
FORECAST AREA BY WED...BUT THE BETTER COLD ADVECTION COMES IN THE
EXTENDED PERIOD BEHIND THE WED DISTURBANCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...
BROAD UPPER TROUGH REMAINS IN PLACE AND DOMINATES THE EXTENDED
FORECAST...GRADUALLY SHIFTING FURTHER ESE LATE IN THE PERIOD.
THIS KEEPS THE REGION IN AN UNSTABLE/UNSETTLED NORTHWEST FLOW WITH
NUMEROUS EMBEDDED SHORT WAVES. MODELS VARY CONSIDERABLY AS TO THE
TIMING AND PLACEMENT OF THESE DISTURBANCES...BUT ENOUGH AGREEMENT
THAT POPS CANNOT BE DROPPED REALLY AT ANY TIME THE OVERALL TREND
IS TO PUSH THE BETTER MOISTURE FURTHER SOUTH OF THE REGION AS THE
WEEK PROGRESSES AND 850MB TEMPS DROP BELOW 0C IN THE NORTHERN
COUNTIES. THE ENTIRE PERIOD SHOULD FEATURE BELOW NORMAL
TEMPERATURES WITH LOW CHC POPS...HIGHEST ACROSS THE MOUNTAINS AND
TOWARD THE SOUTHERN COUNTIES...WITH THE NORTHERN PIEDMONT THE
DRIEST. ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL THROUGHOUT THE
PERIOD...NO REAL CLEAR CONCERN AT THIS POINT FOR FROST/FREEZE
BECAUSE OF CYCLONIC FLOW AND CLOUDS.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
AS OF 142 PM EDT SUNDAY...
KFCX WSR-88D SHOWED RAIN SPREADING NORTHEAST ACROSS THE FORECAST
AREA THIS AFTERNOON...AS A WARM FRONT LIFTS NORTH ACROSS THE
REGION. CEILINGS WILL LOWER TO MVFR AND IFR WITH RAIN.
A STRONG SOUTHEAST LOW LEVEL JET WILL CONTINUE TO INCREASE THIS
AFTERNOON AND TONIGHT WHICH WILL BRING WIND GUSTS AS HIGH AS 30
KTS. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE
BLUE RIDGE...AFTER SUNSET THESE STRONG WINDS ARE NOT EXPECTED TO
REACH THE SURFACE. SHORTEN THE TIME WINDOW AND KEPT LLWS IN THE
KLWB AND KBCB TAFS AFTER 00Z/8PM.
CEILINGS WILL LOWER TO IFR THIS EVENING INTO TONIGHT AND WILL
REMAIN LOW OVERNIGHT. A COLD FRONT APPROACHES LATER MONDAY
WITH SOME THUNDERSTORMS POSSIBLE AHEAD OF AND ALONG THE
FRONT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS IS LIKELY TO KEEP
PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL THE FRONT CLEARS THE
REGION MONDAY EVENING.
MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE
TAF PERIOD.
EXTENDED AVIATION...
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.HYDROLOGY...
AS OF 330 PM EDT SUNDAY...
HAVE EXPANDED THE FLOOD WATCH FOR THE ALLEGHANY HIGHLANDS OF
VIRGINIA.
A DEEP LAYER FROM THE SURFACE THROUGH MID LEVELS OF THE
ATMOSPHERE OF SOUTHEAST WINDS...WILL BE INCREASING TO AROUND 50
KNOTS LATER THIS AFTERNOON AND EVENING. PRECIPITABLE WATER VALUES
JUST ABOVE 1.5 INCHES WILL BE ADVECTED INTO THE FORECAST AREA. THE
STRONGEST LIFT AND HIGHEST RAINFALL AMOUNTS WILL BE FROM 18Z/2PM
THROUGH 06Z/2AM SO HAVE ADDED HEAVY RAIN TO THE FORECAST ALONG THE
BLUE RIDGE FOR THIS TIME FRAME.
TOTAL RAINFALL AMOUNTS WILL RANGE FROM 1 TO 3 INCHES THROUGH
12Z/8AM MONDAY. FLASH FLOOD GUIDANCE VALUES WERE ROUGHLY 1.5 TO
2.5 INCHES FOR 3 HOURS. SO THIS AMOUNT OF RAINFALL HAS THE
POTENTIAL TO PRODUCE FLOODING ON SMALL STREAMS AND CREEKS.
PROBABILISTIC GUIDANCE FOR MAINSTEM RIVERS SUGGESTS A SMALL
POSSIBILITY FOR MINOR FLOODING ALONG THE DAN RIVER AND NEW RIVER.
HOWEVER...THE IS HIGHLY DEPENDENT ON THE AMOUNT OF RAINFALL
THROUGH MONDAY MORNING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH LATE TONIGHT FOR VAZ018>020-022>024-
033>035.
FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ009-012>017-032.
NC...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ001>003-018>020.
WV...NONE.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...KK
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/KK
HYDROLOGY...KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
334 PM EDT SUN APR 19 2015
.SYNOPSIS...
LOW PRESSURE OVER WESTERN KENTUCKY WITH A WARM FRONT EXTENDING EAST
AND COLD FRONT TRAILING SOUTHWARD FROM THE LOW WILL LIFT NORTHEAST
TONIGHT INTO MONDAY. A COLD FRONT CROSSES THE REGION ON
MONDAY...THEN HIGH PRESSURE BUILDS IN FOR TUESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 333 PM EDT SUNDAY...
FLOOD WATCHES REMAIN IN EFFECT INTO TONIGHT.
A WARM FRONT TO OUR SOUTH WILL LIFT NORTH THIS EVENING AND CROSS THE
FORECAST AREA TONIGHT. DEEPER MOISTURE AND HIGHER PWATS WILL
INCREASE IN THE WARM ADVECTION WITH THE NORTHWARD ADVANCE OF THE
FRONT. THE REGIONAL RADAR IMAGE SHOWED WIDESPREAD CONVECTION ACROSS
THE MID ATLANTIC REGION SOUTHWARD TO THE SOUTHEAST US. THERE ARE
SOME CONCERNS OF STRONG CONVECTION ACROSS GEORGIA THIS AFTERNOON MAY
TAKE SOME OF THE MOISTURE AWAY FROM OUR AREA. OUR LOCAL RNK
WRFARW...HIRESW-ARW...NAM AND GFS WAIT UNTIL AFTER 00Z BEFORE
BRINGING IN HEAVIER CONVECTION THIS EVENING...WHILE HRRR AND ECMWF
ARE A LITTLE FASTER WITH TIMING. THE HRRR AND HIRESW-ARW LIFTS THE
PRECIPITATION NORTHEAST WITH MOST OF RAIN PULLING OUT BY 06-08Z.
USED A BLEND OF HRRR AND NAM FOR POPS...TAPERING POPS BACK AFTER 06Z
TONIGHT INTO MONDAY MORNING.
NOT EXPECTING ANY STRONG THUNDERSTORMS THIS AFTERNOON INTO TONIGHT
WITH CLOUD COVER HINDERING INSTABILITIES. HOWEVER...THE LOW LEVEL
JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL RESULT IN
STRONG UPSLOPE AND ISENTROPIC LIFT. THE STRONG WINDS THROUGH A
DEEP LAYER WILL PROVIDE LARGE HELICITY VALUES LATE THIS AFTERNOON
INTO THIS EVENING. THE DAY ONE CONVECTIVE OUTLOOK (SWODY1) PLACED
A MARGINAL (5 PERCENT CHANCE OF WIND) ACROSS SOUTHWEST PORTION OF
CWA. PLAYED LOW TEMPERATURES CLOSE TO ADJMAV WITH READINGS FROM
THE UPPER 40S IN THE NORTHWEST MOUNTAINS TO AROUND 60 DEGREES IN
THE PIEDMONT.
A WARM...MOIST AND UNSTABLE AIRMASS EXPECTED MONDAY. THE ATMOSPHERE
WILL DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT WITH SHOWERS
AND THUNDERSTORMS DEVELOPING MONDAY. INITIALLY CUT BACK POPS CLOSER
TO NAM FOR MONDAY MORNING...THEN INCREASED TO LIKELY BY MONDAY
AFTERNOON. SPC CONTINUES OUR SLIGHT RISK FOR MONDAY ACROSS MOST OF
OUR CWA. THIS IS SUPPORTED BY THE DYNAMIC ENVIRONMENT WITH HEALTHY
SHEAR AND DECENT CAPES AROUND 2K. IT WILL ALSO BE QUITE BREEZY WITH
EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER.
THE FRONT SHOULD BE CLEARING MONDAY NIGHT. HIGH TEMPERATURES MONDAY
WILL RANGE FROM THE MID 60S IN THE MOUNTAINS TO THE LOWER 80S IN THE
PIEDMONT.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 345 AM EDT SUNDAY...
COLDER AIR WORKING IN ON NW WINDS BEHIND THE FRONT WILL COMBINE WITH
LOW LEVEL MOISTURE TO GENERATE SOME UPSLOPE SHOWERS ACROSS THE FAR
WESTERN SLOPES MONDAY NIGHT.
A BROAD CLOSED UPPER LOW BUILDING IN OVER THE NORTHEAST US WILL THEN
KEEP COOL...BREEZY...AND UNSETTLED WEATHER CONDITIONS ACROSS THE REGION
THROUGH MIDWEEK. TUESDAY LOOKS TO BE THE BEST CHANCE FOR A BREAK IN THE
ACTION AS ANY LINGERING SHOWERS ACROSS THE FAR WEST DISSIPATE BY EARLY
MORNING. BY WEDNESDAY THE NEXT COLD FRONT WILL BE ROTATING IN FROM THE
WEST WITH A CHANCE FOR SHOWERS AND MAYBE SOME THUNDER ESPECIALLY WEST
OF THE BLUE RIDGE. TEMPERATURES TUESDAY AND WEDNESDAY WILL BE RUNNING
AT OR SLIGHTLY BELOW NORMAL WITH UPPER 50S/LOWER 60S WEST OF THE BLUE
RIDGE AND MID 60S TO AROUND 70 EAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 350 PM EDT SATURDAY...
MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW
CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER
THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE
UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO ACROSS THE
PIEDMONT. FOLLOWING THIS DISTURBANCE COMES THE BONAFIDE COLDER AIR
WHICH PROMISES TO PUSH 850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE
REMAINDER OF THE WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH
GRADUALLY SHIFTS MORE TOWARD THE MID-ATLANTIC LATE IN THE
PERIOD...STRENGTHENING THE NORTHWEST FLOW ACROSS THE REGION...AND
ALLOWING 850MB TEMPS TO BOTTOM OUT ACROSS THE NORTH AROUND -5C BY
SATURDAY. THIS PATTERN WILL CONTINUE TO RESULT IN A SIGNIFICANT
TEMPERATURE DIFFERENCE FROM THE WESTERN MOUNTAINS WITH CLOUDS AND
VARIABLE CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST
FLOW ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW
NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS
SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN THE
UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY FROST/FREEZE
CONCERN AT THIS POINT.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
AS OF 142 PM EDT SUNDAY...
KFCX WSR-88D SHOWED RAIN SPREADING NORTHEAST ACROSS THE FORECAST
AREA THIS AFTERNOON...AS A WARM FRONT LIFTS NORTH ACROSS THE
REGION. CEILINGS WILL LOWER TO MVFR AND IFR WITH RAIN.
A STRONG SOUTHEAST LOW LEVEL JET WILL CONTINUE TO INCREASE THIS
AFTERNOON AND TONIGHT WHICH WILL BRING WIND GUSTS AS HIGH AS 30
KTS. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE
BLUE RIDGE...AFTER SUNSET THESE STRONG WINDS ARE NOT EXPECTED TO
REACH THE SURFACE. SHORTEN THE TIME WINDOW AND KEPT LLWS IN THE
KLWB AND KBCB TAFS AFTER 00Z/8PM.
CEILINGS WILL LOWER TO IFR THIS EVENING INTO TONIGHT AND WILL
REMAIN LOW OVERNIGHT. A COLD FRONT APPROACHES LATER MONDAY
WITH SOME THUNDERSTORMS POSSIBLE AHEAD OF AND ALONG THE
FRONT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS IS LIKELY TO KEEP
PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL THE FRONT CLEARS THE
REGION MONDAY EVENING.
MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE
TAF PERIOD.
EXTENDED AVIATION...
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.HYDROLOGY...
AS OF 330 PM EDT SUNDAY...
HAVE EXPANDED THE FLOOD WATCH FOR THE ALLEGHANY HIGHLANDS OF
VIRGINIA.
A DEEP LAYER FROM THE SURFACE THROUGH MID LEVELS OF THE
ATMOSPHERE OF SOUTHEAST WINDS...WILL BE INCREASING TO AROUND 50
KNOTS LATER THIS AFTERNOON AND EVENING. PRECIPITABLE WATER VALUES
JUST ABOVE 1.5 INCHES WILL BE ADVECTED INTO THE FORECAST AREA. THE
STRONGEST LIFT AND HIGHEST RAINFALL AMOUNTS WILL BE FROM 18Z/2PM
THROUGH 06Z/2AM SO HAVE ADDED HEAVY RAIN TO THE FORECAST ALONG THE
BLUE RIDGE FOR THIS TIME FRAME.
TOTAL RAINFALL AMOUNTS WILL RANGE FROM 1 TO 3 INCHES THROUGH
12Z/8AM MONDAY. FLASH FLOOD GUIDANCE VALUES WERE ROUGHLY 1.5 TO
2.5 INCHES FOR 3 HOURS. SO THIS AMOUNT OF RAINFALL HAS THE
POTENTIAL TO PRODUCE FLOODING ON SMALL STREAMS AND CREEKS.
PROBABILISTIC GUIDANCE FOR MAINSTEM RIVERS SUGGESTS A SMALL
POSSIBILITY FOR MINOR FLOODING ALONG THE DAN RIVER AND NEW RIVER.
HOWEVER...THE IS HIGHLY DEPENDENT ON THE AMOUNT OF RAINFALL
THROUGH MONDAY MORNING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH LATE TONIGHT FOR VAZ018>020-022>024-
033>035.
FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ009-012>017-032.
NC...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ001>003-018>020.
WV...NONE.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...KK
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/KK
HYDROLOGY...AMS/KK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1158 AM CDT SUN APR 19 2015
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND MONDAY
ISSUED AT 327 AM CDT SUN APR 19 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SPLIT FLOW
OVER CENTRAL NORTH AMERICA EARLY THIS MORNING. IN THE SOUTHERN
STREAM...UPPER LEVEL LOW PRESSURE IS SPINNING OVER WESTERN
KANSAS/EASTERN COLORADO. AHEAD OF THIS FEATURE...SHOWERS AND
THUNDERSTORMS ARE OCCURRING FROM NEBRASKA TO LOUISIANA. EVEN
FURTHER NORTHEAST...MID-LEVEL MOISTURE TRANSPORT AND ILL-DEFINED
SHORTWAVES ARE ALSO CREATING SHOWERS AND A FEW THUNDERSTORMS FROM
WESTERN WISCONSIN INTO ILLINOIS. A COUPLE SPOTTY SHOWERS POPPED UP
SHORTLY AFTER MIDNIGHT OVER WOOD COUNTY TO THE DELLS...AND WILL HAVE
TO CARRY AN ISOLATED MENTION EARLY THIS MORNING ACROSS THE
I-39/ROUTE 51 CORRIDOR. IN THE NORTHERN STREAM...SHORTWAVE ENERGY
IS PROGRESSING EAST OVER THE NORTHWEST PLAINS. AS THESE FEATURES
MOVE EAST...PRECIP CHANCES AND TIMING ARE THE MAIN FORECAST CONCERNS.
TODAY...LOW PRESSURE OVER THE NORTHERN PLAINS WILL HEAD EAST WHILE
THE SOUTHERN STREAM LOW WILL LIFT NORTHEAST OVER THE CENTRAL
MISSISSIPPI VALLEY. WEAK SHORTWAVE ACTIVITY ROTATING ON THE EASTERN
PERIPHERY OF THE UPPER LOW OVER WESTERN KANSAS WILL LIFT NORTH
ACROSS THE WESTERN GREAT LAKES TODAY BUT INTO A MORE STABLE AND
DRIER AIRMASS. DESPITE THIS...THE HIGHER RES MODELS AND RUC DEPICT
SPOTTY SHOWERS DEVELOPING OVER CENTRAL AND NORTHEAST WISCONSIN THIS
MORNING WHICH BEAR SOME WEIGHT GIVEN THE SPOTTY SHOWERS POPPING UP
OVER THE DELLS AT THIS HOUR. AS A RESULT...QUITE DIFFICULT TO ADD
MUCH TEMPORAL RESOLUTION TO THE FORECAST THIS MORNING OTHER THAN
SAYING SLIGHT CHANCE OF A SHOWER. FORCING INCREASES OVER WESTERN
WISCONSIN DURING THE AFTERNOON WHEN A FGEN BAND MOVES ACROSS THAT
PART OF THE STATE. THE EASTERN EDGE OF THE INDUCED RAIN BAND WILL
LIKELY BE PUSHING INTO N-C WISCONSIN LATE IN THE AFTERNOON. AM
THINKING EASTERN WISCONSIN WILL REMAIN MOSTLY DRY DUE TO NE FLOW. THE
SLOWER ARRIVAL OF THE PRECIP WILL HELP TEMPERATURES RISE INTO THE
MID 60S OVER CENTRAL WI. CLOUD COVER AND EAST WINDS WILL SUPPORT
MUCH COOLER READINGS OVER EASTERN WI THOUGH.
TONIGHT...THE MEDIUM RANGE MODELS TRACK THE SOUTHERN STREAM SURFACE
LOW FROM CENTRAL ILLINOIS/INDIANA TO NORTHERN LOWER MICHIGAN. SOME
POSSIBILITY THAT THE LOW WILL TRACK WEST OF THIS LINE IN THE
MESOMODELS THOUGH. COMMA HEAD PRECIP FROM THIS LOW LOOKS TO MOVE
INTO NORTHEAST WISCONSIN BY MID TO LATE EVENING. MEANWHILE...RAIN
BAND ASSOCIATED WITH MID-LEVEL FGEN AHEAD OF THE NORTHERN STREAM
WAVE WILL SHIFT EAST THROUGH THE NIGHT ACROSS CENTRAL AND EASTERN
WISCONSIN. SEEMS LIKE A GOOD RECIPE FOR PERIODS OF RAIN ACROSS THE
REGION. LOWS RANGING FROM THE UPPER 30S NORTH TO MID 40S SOUTH.
MONDAY...THE FGEN RAIN BAND WILL GRADUALLY BE WEAKENING AS IT MOVES
EAST ACROSS EASTERN WISCONSIN DURING THE MORNING AND EXITS DURING
THE AFTERNOON. THE MID-LEVEL DRY SLOT WILL WORK OVERHEAD IN THE
WAKE OF THE RAIN DURING THE AFTERNOON AND MAY SEE A FEW PEAKS OF
SUNSHINE. OTHERWISE...BECOMING BREEZY WITH HIGHS IN THE MID 40S
NORTH TO LOW 50S SOUTH.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
ISSUED AT 327 AM CDT SUN APR 19 2015
CLOSED UPPER LOW WILL BRING UNSETTLED AND COOL CONDITIONS TO THE
REGION TUESDAY INTO WEDNESDAY. THE UPPER LOW WILL GRADUALLY PULL
AWAY THURSDAY AND FRIDAY...BUT CYCLONIC FLOW COULD STILL BRING A
SMALL CHANCE OF PRECIPITATION THURSDAY INTO FRIDAY ACROSS THE
FAR NORTH. DESPITE THE CALENDER STATING ITS LATE APRIL...SOME SNOW
IS IN THE FORECAST LATE AT NIGHT INTO THE MORNING HOURS. COULD BE SOME
MINOR ACCUMULATION ACROSS THE FAR NORTH TUESDAY MORNING AND AGAIN
WEDNESDAY MORNING.
BELOW NORMAL TEMPERATURES WILL CONTINUE INTO NEXT WEEKEND WITH DRY
CONDITIONS EXPECTED ON FRIDAY. ONLY MINOR CHANGES MADE TO PRECIPITATION
CHANCES AND TEMPERATURES DURING THE PERIOD.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1146 AM CDT SUN APR 19 2015
BROKEN MIDLEVEL CIGS CONTINUE THIS AFTERNOON INTO THE
EVENING...THOUGH VFR CONDITIONS SHOULD PREVAIL. LOW PRESSURE THEN
MOVE ACROSS THE GREAT LAKES REGION TONIGHT AND WILL RESULT IN
AN AREA OF STEADY RAIN OVERNIGHT. PRECIP SHOULD BE SLOWER TO
ARRIVE THAN PREVIOUSLY FORECASTED...WITH RAIN ARRIVING LATE EARLY
TONIGHT THROUGH MIDNIGHT. LOW END IFR CONDITIONS ARE EXPECTED WITH
THIS AREA OF RAIN...WITH LIFR CIGS POSSIBLE AS CURRENT OBS IN
AREA OF INCOMING PRECIP IN IL/IN SHOW SCATTERED CIGS BELOW 500FT.
LIFR CONDITIONS IN CURRENT RAIN NOT WIDESPREAD ENOUGH AND GUIDANCE
WAFFLING ON HOW LOW CIGS WILL GO...SO NOT ENOUGH CONFIDENCE TO ADD
IT TO THE TAFS AT THIS TIME...BUT WILL BE SOMETHING TO MONITOR.
HEAVIEST RAIN AND WORST CONDITIONS WILL LIKELY BE OVER EASTERN TAF
SITES.
RAIN WILL TAPER OFF MONDAY MORNING IN NORTH-CENTRAL WISCONSIN
WITH MVFR CIGS POSSIBLE BY THE SECOND HALF OF THE MORNING. LIGHT
RAIN WILL CONTINUE FURTHER EAST WITH IFR CONDITIONS MOST LIKELY
HOLDING TIGHT UNTIL LATER IN THE MORNING. WINDS WILL BACK FROM
SOUTHEAST THIS AFTERNOON...TO NORTH OVERNIGHT...TO NORTHEAST
MONDAY AS A COLD FRONT SWEEPS THROUGH THE STATE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......ALLEN