Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/23/15
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
1237 PM CDT THU MAY 21 2015
.AVIATION...
MVFR CIGS CONTINUE DUE TO INVERSION OVER THE REGION. THERE WILL BE
LIFTING THIS AFTERNOON...BUT SOUTHERN SITES WILL REMAIN MVFR
THROUGH 22/00Z. WITH NORTHEAST WINDS OVERNIGHT...SOME LOWER CLOUDS
ARE EXPECTED DUE TO THE TERRAIN...BUT KEPT SCT FOR NOW. NEXT
SYSTEM WILL APPROACH AFTER SUNRISE FROM THE WEST...BUT ONLY AN
INCREASE IN CLOUD COVER FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 412 AM CDT THU MAY 21 2015/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
INITIALLY UPDATED POPS ACROSS PORTIONS OF WESTERN AND SOUTHERN
ARKANSAS TO REFLECT CURRENT RADAR TRENDS AS WELL AS TREND TOWARDS
THE HRRR WHICH SHOWS PRECIPITATION CONTINUING FOR MUCH OF THE FIRST
HALF OF THE DAY ACROSS SOUTHERN ARKANSAS. PRECIP SHOULD CONTINUE TO
WEAKEN AND SPREAD TO THE SOUTH AS SLOW MOVING COLD FRONT CONTINUES
TO MOVE SOUTH.
CONTINUED THE TREND OF LOWERING TEMPS AND GOING BELOW GUIDANCE FOR
THURSDAY AND FRIDAY WITH STRONG NORTHERLY FLOW IN PLACE. AT THIS
POINT..TEMPERATURES WILL BE RUNNING TEN TO FIFTEEN DEGREES BELOW
NORMAL IN MOST LOCATIONS ACROSS THE STATE.
HIGH PRESSURE AT THE SURFACE BEGINS TO SHIFT OFF TO THE EAST LATE
FRIDAY ALLOWING A RETURN OF MOIST SOUTHERLY FLOW. SOUTHERLY FLOW
WILL BE DEEP AND MOISTURE WILL INCREASE DRAMATICALLY LATE SATURDAY.
BEGAN TO TREND DEWPOINTS UP AT THIS POINT WITH RAW MODELS SUGGESTING
70 PLUS DEWPOINTS WILL BE IN PLACE ACROSS SW ARKANSAS.
AT THIS POINT THERE STILL REMAINS SOME UNCERTAINTY ON THE SEVERE
WEATHER POTENTIAL. BUT MODEL SOUNDINGS DO SUGGEST SOME STRONGER
THUNDERSTORMS WILL BE POSSIBLE ON SUNDAY ACROSS WESTERN ARKANSAS.
RAINFALL TOTALS WILL GENERALLY BE LIGHT AND LIMITED TO WESTERN
ARKANSAS THROUGH THE FIRST HALF OF THE WEEKEND. RAINFALL CHANCES AND
QPF INCREASE SUNDAY EVENING WITH AN ADDITIONAL ONE TO TWO INCHES
POSSIBLE. WESTERN ARKANSAS HAS BEEN FAIRLY HARD HIT IN THE PAST FEW
WEEKS WITH HEAVY RAIN...AND AN ADDITIONAL ROUND OF HEAVY RAIN WILL
LIKELY BE PROBLEMATIC. THIS IS STILL A FEW DAYS OUT...BUT BEARS
WATCHING IN FUTURE FORECASTS.
LONG TERM...MONDAY THROUGH WEDNESDAY
NO SIG CHGS WERE MADE TO THE CURRENT FCST AS THE LATEST MODEL TRENDS
CONT TO INDC AN UNSETTLED WX PATTERN ACRS THE MID SOUTH. A
PERSISTENT SWLY FLOW ALOFT WL CONT TO BRING SEVERAL UPR LVL IMPULSES
NEWD THRU AR. THESE FEATURES WL INTERACT WITH THE MOIST AIRMASS IN
PLACE TO PRODUCE GOOD CHCS OF SHRA/TSRA. WITH SOILS ALREADY QUITE
SATURATED...ANY ADDITIONAL RAINFALL WL ONLY ENHANCE THE CHCS OF
ADDITIONAL FLOODING OVR MUCH OF THE AREA.
SOME OF THE MODELS DO INDC THAT THE UPR PATTERN WL DE-AMPLIFY OVR
THE SRN STATES HEADING INTO THE MIDDLE OF NEXT WEEK. THIS WL RESULT
IN DRIER CONDS FOR THE FA.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...58
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
639 AM CDT THU MAY 21 2015
.AVIATION...21/12Z TAF CYCLE
MVFR CIGS WL BE WIDESPREAD ACRS THE FA THRU MUCH OF THE MRNG. THE
NRN EDGE OF ONGOING SHRA/TSRA ACTIVITY ACRS SRN AR COULD BRIEFLY
AFFECT THE SRN TAF SITES EARLY IN THE PD...WITH VCSH MENTIONED
ATTM. PRECIP WL CONT TO SHIFT SLOLY SWD AS THE MRNG PROGRESSES.
LOW CLOUDS WL GRADUALLY ERODE HEADING INTO THIS AFTN AS DRIER AIR
CONTS TO FILTER INTO THE AREA...WITH VFR CONDS RETURNING. /44/
&&
.PREV DISCUSSION... /ISSUED 412 AM CDT THU MAY 21 2015/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
INITIALLY UPDATED POPS ACROSS PORTIONS OF WESTERN AND SOUTHERN
ARKANSAS TO REFLECT CURRENT RADAR TRENDS AS WELL AS TREND TOWARDS
THE HRRR WHICH SHOWS PRECIPITATION CONTINUING FOR MUCH OF THE FIRST
HALF OF THE DAY ACROSS SOUTHERN ARKANSAS. PRECIP SHOULD CONTINUE TO
WEAKEN AND SPREAD TO THE SOUTH AS SLOW MOVING COLD FRONT CONTINUES
TO MOVE SOUTH.
CONTINUED THE TREND OF LOWERING TEMPS AND GOING BELOW GUIDANCE FOR
THURSDAY AND FRIDAY WITH STRONG NORTHERLY FLOW IN PLACE. AT THIS
POINT..TEMPERATURES WILL BE RUNNING TEN TO FIFTEEN DEGREES BELOW
NORMAL IN MOST LOCATIONS ACROSS THE STATE.
HIGH PRESSURE AT THE SURFACE BEGINS TO SHIFT OFF TO THE EAST LATE
FRIDAY ALLOWING A RETURN OF MOIST SOUTHERLY FLOW. SOUTHERLY FLOW
WILL BE DEEP AND MOISTURE WILL INCREASE DRAMATICALLY LATE SATURDAY.
BEGAN TO TREND DEWPOINTS UP AT THIS POINT WITH RAW MODELS SUGGESTING
70 PLUS DEWPOINTS WILL BE IN PLACE ACROSS SW ARKANSAS.
AT THIS POINT THERE STILL REMAINS SOME UNCERTAINTY ON THE SEVERE
WEATHER POTENTIAL. BUT MODEL SOUNDINGS DO SUGGEST SOME STRONGER
THUNDERSTORMS WILL BE POSSIBLE ON SUNDAY ACROSS WESTERN ARKANSAS.
RAINFALL TOTALS WILL GENERALLY BE LIGHT AND LIMITED TO WESTERN
ARKANSAS THROUGH THE FIRST HALF OF THE WEEKEND. RAINFALL CHANCES AND
QPF INCREASE SUNDAY EVENING WITH AN ADDITIONAL ONE TO TWO INCHES
POSSIBLE. WESTERN ARKANSAS HAS BEEN FAIRLY HARD HIT IN THE PAST FEW
WEEKS WITH HEAVY RAIN...AND AN ADDITIONAL ROUND OF HEAVY RAIN WILL
LIKELY BE PROBLEMATIC. THIS IS STILL A FEW DAYS OUT...BUT BEARS
WATCHING IN FUTURE FORECASTS.
LONG TERM...MONDAY THROUGH WEDNESDAY
NO SIG CHGS WERE MADE TO THE CURRENT FCST AS THE LATEST MODEL TRENDS
CONT TO INDC AN UNSETTLED WX PATTERN ACRS THE MID SOUTH. A
PERSISTENT SWLY FLOW ALOFT WL CONT TO BRING SEVERAL UPR LVL IMPULSES
NEWD THRU AR. THESE FEATURES WL INTERACT WITH THE MOIST AIRMASS IN
PLACE TO PRODUCE GOOD CHCS OF SHRA/TSRA. WITH SOILS ALREADY QUITE
SATURATED...ANY ADDITIONAL RAINFALL WL ONLY ENHANCE THE CHCS OF
ADDITIONAL FLOODING OVR MUCH OF THE AREA.
SOME OF THE MODELS DO INDC THAT THE UPR PATTERN WL DE-AMPLIFY OVR
THE SRN STATES HEADING INTO THE MIDDLE OF NEXT WEEK. THIS WL RESULT
IN DRIER CONDS FOR THE FA.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
412 AM CDT THU MAY 21 2015
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
INITIALLY UPDATED POPS ACROSS PORTIONS OF WESTERN AND SOUTHERN
ARKANSAS TO REFLECT CURRENT RADAR TRENDS AS WELL AS TREND TOWARDS
THE HRRR WHICH SHOWS PRECIPITATION CONTINUING FOR MUCH OF THE FIRST
HALF OF THE DAY ACROSS SOUTHERN ARKANSAS. PRECIP SHOULD CONTINUE TO
WEAKEN AND SPREAD TO THE SOUTH AS SLOW MOVING COLD FRONT CONTINUES
TO MOVE SOUTH.
CONTINUED THE TREND OF LOWERING TEMPS AND GOING BELOW GUIDANCE FOR
THURSDAY AND FRIDAY WITH STRONG NORTHERLY FLOW IN PLACE. AT THIS
POINT..TEMPERATURES WILL BE RUNNING TEN TO FIFTEEN DEGREES BELOW
NORMAL IN MOST LOCATIONS ACROSS THE STATE.
HIGH PRESSURE AT THE SURFACE BEGINS TO SHIFT OFF TO THE EAST LATE
FRIDAY ALLOWING A RETURN OF MOIST SOUTHERLY FLOW. SOUTHERLY FLOW
WILL BE DEEP AND MOISTURE WILL INCREASE DRAMATICALLY LATE SATURDAY.
BEGAN TO TREND DEWPOINTS UP AT THIS POINT WITH RAW MODELS SUGGESTING
70 PLUS DEWPOINTS WILL BE IN PLACE ACROSS SW ARKANSAS.
AT THIS POINT THERE STILL REMAINS SOME UNCERTAINTY ON THE SEVERE
WEATHER POTENTIAL. BUT MODEL SOUNDINGS DO SUGGEST SOME STRONGER
THUNDERSTORMS WILL BE POSSIBLE ON SUNDAY ACROSS WESTERN ARKANSAS.
RAINFALL TOTALS WILL GENERALLY BE LIGHT AND LIMITED TO WESTERN
ARKANSAS THROUGH THE FIRST HALF OF THE WEEKEND. RAINFALL CHANCES AND
QPF INCREASE SUNDAY EVENING WITH AN ADDITIONAL ONE TO TWO INCHES
POSSIBLE. WESTERN ARKANSAS HAS BEEN FAIRLY HARD HIT IN THE PAST FEW
WEEKS WITH HEAVY RAIN...AND AN ADDITIONAL ROUND OF HEAVY RAIN WILL
LIKELY BE PROBLEMATIC. THIS IS STILL A FEW DAYS OUT...BUT BEARS
WATCHING IN FUTURE FORECASTS.
&&
.LONG TERM...MONDAY THROUGH WEDNESDAY
NO SIG CHGS WERE MADE TO THE CURRENT FCST AS THE LATEST MODEL TRENDS
CONT TO INDC AN UNSETTLED WX PATTERN ACRS THE MID SOUTH. A
PERSISTENT SWLY FLOW ALOFT WL CONT TO BRING SEVERAL UPR LVL IMPULSES
NEWD THRU AR. THESE FEATURES WL INTERACT WITH THE MOIST AIRMASS IN
PLACE TO PRODUCE GOOD CHCS OF SHRA/TSRA. WITH SOILS ALREADY QUITE
SATURATED...ANY ADDITIONAL RAINFALL WL ONLY ENHANCE THE CHCS OF
ADDITIONAL FLOODING OVR MUCH OF THE AREA.
SOME OF THE MODELS DO INDC THAT THE UPR PATTERN WL DE-AMPLIFY OVR
THE SRN STATES HEADING INTO THE MIDDLE OF NEXT WEEK. THIS WL RESULT
IN DRIER CONDS FOR THE FA.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 65 47 68 54 / 10 10 0 20
CAMDEN AR 71 55 74 59 / 30 10 10 20
HARRISON AR 65 46 65 51 / 10 10 30 30
HOT SPRINGS AR 71 53 69 58 / 20 10 20 20
LITTLE ROCK AR 70 53 72 58 / 10 10 10 20
MONTICELLO AR 68 53 73 60 / 30 10 10 10
MOUNT IDA AR 71 51 66 57 / 20 10 30 20
MOUNTAIN HOME AR 66 46 66 51 / 10 10 10 20
NEWPORT AR 65 48 70 56 / 10 10 0 10
PINE BLUFF AR 68 53 72 59 / 20 10 10 20
RUSSELLVILLE AR 71 52 68 56 / 10 10 30 20
SEARCY AR 67 48 72 54 / 10 10 10 20
STUTTGART AR 67 52 72 59 / 20 10 10 20
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...65 / LONG TERM...44
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
316 PM PDT Thu May 21 2015
.Synopsis...
Mild weather with mountain showers and thunderstorms will continue
through Friday. Warmer temperatures with fewer mountain showers
expected this weekend into next week.
&&
.Discussion...
A broad upper level trough remains quasi-stationary along the West
Coast, with blocking ridge situated over the Rockies. Several
shortwaves have been rotating through this upper trough, and the
current one is moving toward the California coast today.
Widespread showers and thunderstorms have once again developed
this afternoon across the interior mountains of Northern
California once again. Lightning networks havent detected quite as
much lightning as yesterday, but today`s showers do seem to be
producing more in the way of precipitation. We`ve also seen a few
reports of snow above 8000 ft or so along the high Sierra. With
southeast to easterly flow aloft, some showers may try to work
their way down the hill toward the Valley this evening into Friday
morning. The ARW, NMM, and HRRR all hint at this possibility.
The aforementioned shortwave pushes south toward Southern
California on Friday, with steering flow becoming more northerly.
While we should still expect some mountain showers and
thunderstorms Friday afternoon, they shouldn`t be as widespread.
Northerly flow aloft will continue over Northern California
through the weekend. This should promote warmer weather, with
temperatures closer to normal. Isolated showers will still be
possible over the mountains, but confined to primarily Lake Tahoe
and southward.
Dang
&&
.Extended Discussion (Monday through Thursday)
For the extended period, the ability of the general upper trough
pattern over the region to persist through the rest of May is
impressive. with no significant heat-ups in sight. Upper low
pressure systems with weak short waves will pass through at times.
Unlike the current system, most of the lows will be centered to the
north and east of the forecast area. Most of the instability will
linger over the mountains, with afternoon heating bringing some
thunderstorms. The Valley should remain generally dry.
Temperatures will gradually warm to near to slightly above normal
levels by mid week on. Daytime highs in the valley will generally
be in the low to mid 80s with 70s in Delta Breeze influenced areas
(upper 60s for the Vallejo/Benicia area). Mountain highs will
range in the 50s/60s while Foothills warm into the 70s. EK
&&
.Aviation...
General VFR conditions expected for tonight, except in
SCT showers and ISO evening thunderstorms in the mountains and
foothills, possibly passing through the northern Sacramento Valley
. Could see some bkn020-025 cigs for the Delta and into the
southern Sacramento Valley 12-18z Friday morning. The Delta could
see gusts to 30kt tonight, with southwest gusts to around 20kt for
the Sacramento metro area through 05z. EK
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1102 AM PDT THU MAY 21 2015
.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.
&&
.DISCUSSION...AS OF 08:45 AM PDT THURSDAY...DEEP STRATUS DECK
COVERS MUCH OF THE BAY AREA THIS MORNING...MOSTLY CLOUDY START TO
THE DAY. INTERESTING TO NOTE THE CLOUDS ARE NOT YOUR TYPICAL
MARINE LAYER...SODARS AND PROFILERS DO NOT INDICATE A DEFINED
MARINE LAYER. THE KOAK SOUNDING ON THE OTHER HAND DOES SHOW A
MOIST LOWER 5K FEET. SYNOPTICALLY SPEAKING...A WEAK UPPER LEVEL
DISTURBANCE IS CURRENTLY SITTING OFF THE SF BAY COAST. THE
ASSOCIATED LIFT AND MOIST LOWER 5K FT HELPED TO PRODUCE SOME LIGHT
SHOWERS OVERNIGHT WITH SEVERAL STATIONS MEASURING UP TO A TENTH.
FOR THE REST OF TODAY...ANOTHER STRONGER UPPER LOW IS FORECAST TO
DROP SOUTHWARD THROUGH THE BASE OF A BROAD UPPER TROUGH. THE
UPPER LOW CAN BE SEEN ON THE WATER VAPOR NEAR 130W. LATEST SHORT
TERM MODELS...THE HRRR AND RAP BOTH INDICATE INCREASED SHOWER
ACTIVITY THIS AFTERNOON AS THE UPPER LOW DEEPENS OFF THE COAST.
THE BEST CHANCE FOR SHOWERS WILL BE OVER TERRAIN FAVORED
LOCATIONS. IN FACT...THE LATEST NAM/HRRR INDICATE A LITTLE BIT OF
SFC INSTABILITY OVER THE E BAY HILLS AND THE GABILAN RANGE THIS
AFTERNOON. THEREFORE COULD NOT TOTALLY RULE OUT SOME THUNDER AS WELL.
GIVEN THE UNCERTAINTY OF ACTUAL LOCATIONS FOR SHOWER
ACTIVITY...LATEST FORECAST HAS BLANKET COVERAGE OF SHOWERS THIS
AFTERNOON. NO MAJOR UPDATE IS NEEDED AT THIS TIME...BUT WILL LIKE
TWEAK THE WEATHER GRIDS TO BETTER REFLECT REALITY THIS AFTERNOON.
&&
.PREV DISCUSSION...AS OF 3:58 AM PDT THURSDAY...THE TROUGH AND
UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY WITH
HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE EASTERN
PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND FOR
SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER TROUGH
WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.
&&
.AVIATION...AS OF 11:00 AM PDT THURSDAY...WIDESPREAD CLOUDS TODAY
ALONG WITH A DEEP ALBEIT POORLY DEFINED MARINE LAYER PLUS ONSHORE
SURFACE FLOW WILL KEEPS CIGS GOING IN ALL SPOTS THROUGH THE
PERIOD. DID MAKE SOME ADJUSTMENTS TO THE TAFS FROM THE PREVIOUS
PACKAGE TO KEEP CIGS LOWER IN MOST SPOTS. MVFR GENERALLY EXPECTED
TONIGHT. WINDS SPEEDS MOSTLY UNDER 15 KT EXCEPT AT SFO. A FEW LIGHT
SHOWERS ALSO POSSIBLE THROUGH THE PERIOD. MODERATE CONFIDENCE.
VICINITY OF KSFO...STILL SHOWING BKN015 ON THE 5 MINUTE OB
ALTHOUGH CAMS ARE SHOWING DEFINITE BREAKS AND LIFTING. WIDESPREAD
CLOUDS THROUGH THE AREA ALONG WITH WESTERLY FLOW AT THE SURFACE
SHOULD KEEPS CIGS GOING ALL DAY UNDER 5KFT. WESTERLY WINDS FROM
21Z TO 02Z AROUND 15 KT FROM 260 TO 280. MODERATE CONFIDENCE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR THROUGH THE PERIOD DUE TO
PERSISTENT ONSHORE FLOW PLUS DEEP MARINE LAYER. SPEEDS WILL PICK
UP THROUGH THE DAY WITH WESTERLY VALUES OF 8 TO 12 KT AFTER 20Z.
LOCALLY HIGHER GUSTS TO KSNS POSSIBLE. MODERATE CONFIDENCE.
&&
.MARINE...AS OF 11:00 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM
&&
$$
PUBLIC FORECAST: MM
AVIATION/MARINE: BELL
VISIT US AT WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
848 AM PDT THU MAY 21 2015
.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.
&&
.DISCUSSION...AS OF 08:45 AM PDT THURSDAY...DEEP STRATUS DECK
COVERS MUCH OF THE BAY AREA THIS MORNING...MOSTLY CLOUDY START TO
THE DAY. INTERESTING TO NOTE THE CLOUDS ARE NOT YOUR TYPICAL
MARINE LAYER...SODARS AND PROFILERS DO NOT INDICATE A DEFINED
MARINE LAYER. THE KOAK SOUNDING ON THE OTHER HAND DOES SHOW A
MOIST LOWER 5K FEET. SYNOPTICALLY SPEAKING...A WEAK UPPER LEVEL
DISTURBANCE IS CURRENTLY SITTING OFF THE SF BAY COAST. THE
ASSOCIATED LIFT AND MOIST LOWER 5K FT HELPED TO PRODUCE SOME LIGHT
SHOWERS OVERNIGHT WITH SEVERAL STATIONS MEASURING UP TO A TENTH.
FOR THE REST OF TODAY...ANOTHER STRONGER UPPER LOW IS FORECAST TO
DROP SOUTHWARD THROUGH THE BASE OF A BROAD UPPER TROUGH. THE
UPPER LOW CAN BE SEEN ON THE WATER VAPOR NEAR 130W. LATEST SHORT
TERM MODELS...THE HRRR AND RAP BOTH INDICATE INCREASED SHOWER
ACTIVITY THIS AFTERNOON AS THE UPPER LOW DEEPENS OFF THE COAST.
THE BEST CHANCE FOR SHOWERS WILL BE OVER TERRAIN FAVORED
LOCATIONS. IN FACT...THE LATEST NAM/HRRR INDICATE A LITTLE BIT OF
SFC INSTABILITY OVER THE E BAY HILLS AND THE GABILAN RANGE THIS
AFTERNOON. THEREFORE COULD NOT TOTALLY RULE OUT SOME THUNDER AS WELL.
GIVEN THE UNCERTAINTY OF ACTUAL LOCATIONS FOR SHOWER
ACTIVITY...LATEST FORECAST HAS BLANKET COVERAGE OF SHOWERS THIS
AFTERNOON. NO MAJOR UPDATE IS NEEDED AT THIS TIME...BUT WILL LIKE
TWEAK THE WEATHER GRIDS TO BETTER REFLECT REALITY THIS AFTERNOON.
&&
.PREV DISCUSSION...AS OF 3:58 AM PDT THURSDAY...THE TROUGH AND
UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY WITH
HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE EASTERN
PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND FOR
SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER TROUGH
WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.
&&
.AVIATION...AS OF 4:57 AM PDT THURSDAY...A PERSISTENT AREA OF LOW
PRESSURE POSITIONED OVER THE WEST COAST WILL MAINTAIN CLOUD COVER
OVER THE TERMINALS TODAY. HOWEVER...A SMALLER SCALE LOW PRESSURE
SYSTEM WORKING ITS WAY TOWARDS THE CENTRAL CALIFORNIA COAST WILL
LIFT THE CLOUD DECK A BIT LATER THIS MORNING INTO THE AFTERNOON
HOURS PROVIDING THE AREA WITH A POSSIBILITY OF SHOWERS.
VICINITY OF KSFO...MVFR CIGS BKN-OVC030 ARE EXPECTED TO IMPROVE TO
VFR BKN-OVC035-050 LATER THIS MORNING INTO THE AFTERNOON HOURS. A
PERIOD OF BKN015 WILL BE POSSIBLE DURING THE EARLY MORNING HOURS. A
SLIGHT CHANCE OF SHOWERS IS ALSO IN THE GENERAL AREA FORECAST.
WESTERLY WINDS WILL REACH 15 KT THIS AFTERNOON.
CONFIDENCE IS MODERATE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR CIGS BKN-OVC030 ARE EXPECTED
TO PREVAIL TODAY WITH A PERIOD OF BKN012 POSSIBLE EARLY THIS
MORNING. A SLIGHT CHANCE OF SHOWERS IS IN THE GENERAL AREA
FORECAST FOR THE LATE MORNING AFTERNOON HOURS. WESTERLY WINDS WILL
REACH 10 KT THIS AFTERNOON WITH STRONGER GUSTS IN THE SALINAS
VALLEY.
CONFIDENCE IS MODERATE.
&&
.MARINE...AS OF 02:23 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM
&&
$$
PUBLIC FORECAST: MM
AVIATION/MARINE: LARRY
VISIT US AT WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1044 PM PDT WED MAY 20 2015
.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.
&&
.DISCUSSION...AS OF 9:00 PM PDT WEDNESDAY...UPPER LEVEL TROUGH JUST
WEST OF SAN FRANCISCO BROUGHT ANOTHER DAY OF COOL TEMPERATURES TO
THE AREA. STRATUS BURNED OFF IN SOME AREAS THIS AFTERNOON BUT OAK
SOUNDING SHOWS A DEEP MARINE LAYER AROUND 3000 FEET SO LOW CLOUDS
WILL REDEVELOP AND EXTEND WELL INLAND TONIGHT.
A STRONG DISTURBANCE APPROACHING THE BACK SIDE OF THE TROUGH WILL
INTENSIFY THE TROUGH AND PUSH IT TOWARDS SOUTHERN CALIFORNIA ON THURSDAY.
THIS WILL HELP DEEPEN THE MARINE LAYER EVEN MORE ON THURSDAY...TO
THE POINT WHERE THERE COULD BE LOCAL DRIZZLE OR LIGHT SHOWERS.
THIS ALSO RENEWS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS OVER
THE MOUNTAINS WITH THE BEST CHANCES OVER THE SAN BENITO COUNTY
MOUNTAINS. THE LATEST HRRR AND WRF MODELS SHOW SCATTERED PRECIP
AMOUNTS OF 1 TO 3 HUNDREDTHS OF AN INCH NEAR THE COAST AND LIGHT
CONVECTIVE PRECIP IN THE SAN BENITO COUNTY MOUNTAINS.
SLIGHT PRECIP CHANCES CONTINUE INTO FRIDAY AS THE LOW MOVES INLAND
OVER SOUTHERN CALIFORNIA BUT THUNDERSTORM CHANCES WILL BE
DIMINISHED ON THE BACK SIDE OF THE LOW. PRECIP CHANCES END FRIDAY
NIGHT.
PREVIOUS MODEL RUNS INDICATED AN UPPER LEVEL RIDGE BUILDING OFF
THE COAST THIS WEEKEND BUT LATEST MODELS ARE BRINGING ANOTHER
UPPER LEVEL DISTURBANCE ALONG THE BACK SIDE OF THE LOW THROUGH
THE NORTHERN CALIFORNIA INTERIOR ON SATURDAY WITH ONLY WEAK
RIDGING SUNDAY AND MONDAY. DRY WEATHER IS STILL EXPECTED AND
TEMPERATURES SHOULD STILL WARM UP SATURDAY THROUGH MONDAY BUT NOT
AS MUCH AS ORIGINALLY THOUGHT.
&&
.AVIATION...AS OF 10:44 PM PDT WEDNESDAY...LOW CLOUD ARE FILLING
IN ACROSS THE REGION WITH BORDERLINE IFR/MVFR CIGS BEING REPORTED.
ONSHORE FLOW WILL PREVAIL THROUGH TONIGHT WITH GUSTIER WINDS
FORECAST THURSDAY AFTERNOON. THE LOW SITUATED OVER THE REGION IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.
VICINITY OF KSFO...BORDERLINE IFR/MVFR CIGS EXPECTED THROUGH
TONIGHT. CIGS ARE EXPECTED TO LIFT A BIT THURSDAY RESULTING IN
-DZ AND VCSH. ONSHORE FLOW WILL PREVAIL.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED THROUGH MUCH OF
THE FORECAST PERIOD. ONSHORE FLOW WILL CONTINUE. -DZ AND VCSH POSS
THURSDAY MORNING.
&&
.MARINE...AS OF 8:44 PM PDT WEDNESDAY...UNSETTLED WEATHER IS
EXPECTED OVER THE COASTAL WATERS AS A STORM SYSTEM WILL MOVE
THROUGH THE REGION THURSDAY AND FRIDAY. LIGHT TO MODERATE
NORTHERLY WINDS WILL CONTINUE AS THE STORM SYSTEM SLIDES THROUGH.
NORTHERLY WINDS WILL INCREASE FRIDAY AND OVER THE WEEKEND AS THE
NORTHERLY PRESSURE GRADIENT INCREASES.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...NONE.
$$
PUBLIC FORECAST: W PI
AVIATION/MARINE: CW
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AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
339 PM MDT THU MAY 21 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 339 PM MDT THU MAY 21 2015
CLOUD COVER OVER THE FORECSAT AREA HAS BEEN INCREASING AS AN
EJECTING UPPER LEVEL TROUGH ROTATES INTO THE STATE FROM THE SOUTH.
SCATTERED SHOWER ACTIVITY HAS DEVELOPED OVER THE MOUNTAINS BUT
CONVECTION ON THE PLAINS HAS BEEN LIMITED BY THE STABLE LAYER IN
PLACE ACROSS NORTHEAST COLORADO. LATER THIS EVENING...DYNAMIC
FORCING ALOFT SHOULD PRODUCE A WIDESPREAD SHIELD OF PRECIPITATION
THAT EXTENDS FROM THE MOUNTAINS OUT ACROSS THE PLAINS. SNOW LEVELS
IN THE MOUNTAINS SHOULD GRADUALLY COME DOWN...BUT ONLY TO ABOUT
9500 OR 10 THOUSAND FEET. HIGHER MOUNTAIN PASSES ARE EXPECTED TO
PICK UP SEVERAL INCHES OF SNOW...AND THE WINTER WEATHER ADVISORY
REMAINS IN EFFECT FOR THIS.
SHORT RANGE MODELS CONTINUE TO SHOW GENERALLY LIGHT AMOUNTS OF QPF
FROM THIS SYSTEM...WITH THE RAP RUN SHOWING ONE-HALF INCH OR LESS
ACROSS THE PLAINS. ANY RAIN THAT FALLS WILL NOT TAKE VERY LONG TO
FIND ITS WAY TO CREEKS AND STREAMS SINCE THE GROUND REMAINS SO
CLOSE TO SATURATION. LIGHTER AMOUNTS OF RAIN SHOULD REDUCE THE
STRAIN ON THE HYDROLOGIC SITUATION. RIVER LEVELS IN THE DENVER AND
BOULDER AREA HAVE PLENTY OF CAPACITY TO HANDLE TONIGHTS RAINFALL.
LINGERING LIGHT RAIN SHOWERS ARE EXPECTED FRIDAY MORNING AS THE
UPPER TROUGH SLOWLY EXITS THE STATE. THERE SHOULD BE A BREAK IN
THE RAIN BY MIDDAY...BUT AFTERNOON HEATING OF THE MOIST AIRMASS
MAY DE-STABILIZE THE ATMOSPHERE AND PRODUCE SCATTERED
THUNDERSTORMS LATE IN THE AFTERNOON. TEMPERATURES ARE FORECAST TO
BE 5-10 DEGREES WARMER THAN THIS AFTERNOON. THE THREAT OF
LOCALIZED FLOOD PROBLEMS FRIDAY AFTERNOON WILL HINGE ON HOW MUCH
RAIN FALLS TONIGHT AND WHETHER AFTERNOON STORMS TRACK OVER AREAS
THAT RECEIVE APPRECIABLE RAIN TONIGHT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 339 PM MDT THU MAY 21 2015
SCATTERED RAIN SHOWERS AND ISOLATED THUNDERSTORMS ON FRIDAY
EVENING ARE EXPECTED TO GRADUALLY DECREASE AS THE AIRMASS
STABILIZES...WITH MOST AREAS SEEING PARTIAL CLEARING OVERNIGHT.
SATURDAY IS SHAPING UP TO BE A MORE ACTIVE WEATHER DAY. THE LATEST
MODEL RUNS INDICATE A STRONGER WAVE WITH LARGE SCALE Q-G
ASCENT...NOW LOCATED IN THE EASTERN PACIFIC...ROTATING NORTHEAST
OUT OF THE SOUTHWEST U.S. TROUGH. THE FORECAST AREA WILL LIKELY
RESIDE NEAR THE RIGHT REAR ENTRANCE REGION OF A DEPARTING JET AND
THE LEFT EXIT REGION OF AN APPROACHING SPEED MAX BY AFTERNOON. AT
THE SAME TIME...LOW/MID LEVEL WIND FIELDS WILL BE STRENGTHENING...
AND A SURFACE LOW PRESSURE IS EXPECTED TO DEEPEN OVER EASTERN
COLORADO. THIS WOULD PUT A DRYLINE INTO PLAY DEPENDING EXACTLY ON
WHERE THE SURFACE LOW DEEPENS. THINK THE GFS IS OVERDOING THE LOW
LEVEL DRYING OVER NORTHEAST COLORADO...SO AT THIS TIME FAVOR THE
ECMWF/NAM DEPICTION. CAPES ALONG AND AHEAD OF POTENTIAL DRYLINE
WOULD BE CAPABLE OF INCREASING TO 1500-2000 J/KG WITH SUFFICIENT
HEATING AND T/TD OF 68/50. WIND SHEAR WOULD SUPPORT SUPERCELLS
WITH LARGE HAIL AND TORNADO POTENTIAL...BUT ONLY IF WE GET THE
REQUIRED HEATING. WILL CONTINUE TO MONITOR THIS SEVERE POTENTIAL
THROUGH SATURDAY.
BY SUNDAY...AIRMASS IS STILL EXPECTED TO BE UNSTABLE UNDER
GENERAL TROUGHINESS. BOTH WIND SHEAR AND INSTABILITY WOULD BE A
LITTLE WEAKER THOUGH. SEVERE THREAT IS STILL THERE BUT LOWER THAN
SATURDAY. WILL CONTINUE THE FORECAST OF SCATTERED SHOWERS AND
THUNDERSTORMS.
MONDAY THROUGH MOST OF NEXT WEEK WILL FEATURE MORE AFTERNOON AND
EVENING CONVECTION EACH DAY WITH PLENTY OF RESIDUAL MOISTURE.
HOWEVER...TEMPERATURES WILL BE MODERATING AS FLOW ALOFT TURNS
MORE WESTERLY AND WE SHOULD FINALLY SEE MORE SUNSHINE AT LEAST
DURING THE MORNING HOURS. POTENTIAL FOR EMBEDDED DISTURBANCES
THROUGH THIS PERIOD BUT HARD TO TIME THESE RIGHT NOW.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z FRIDAY LATE AFTERNOON)
ISSUED AT 339 PM MDT THU MAY 21 2015
CLOUD HEIGHTS WILL GRADUALLY COME BACK DOWN TO MARGINAL VFR
CATEGORY THROUGH THE EVENING AS THE UPPER LEVEL DISTURBANCE
APPROACHES THE STATE FROM THE SOUTH. WINDS SHOULD TRANSITION TO
THE SOUTHEASTERLY THROUGH THE EVENING HOURS WHICH WILL HELP HOLD
THE MOIST LOW LEVEL AIRMASS IN PLACE OVER THE DENVER METRO AREA.
AS THE HEAVIEST PART OF THE SYSTEM MOVES OVER DENVER DURING THE
MORNING HOURS...IFR CEILINGS MAY DEVELOP. IMPROVED CONDITIONS ARE
EXPECTED BY LATE MORNING AS THE UPPER DISTURBANCE CLEARS OUT OF
THE STATE. ADDITIONAL SHOWERS ARE POSSIBLE LATE TOMORROW AFTERNOON
AS DAYTIME HEATING BEGINS TO DE-STABILIZE THE MOIST AIRMASS THAT
WILL BE IN PLACE.
&&
.HYDROLOGY...
ISSUED AT 339 PM MDT THU MAY 21 2015
FLOOD WARNINGS CONTINUE FOR THE SOUTH PLATTE FROM CENTRAL WELD
COUNTY INTO WESTERN MORGAN COUNTY. AT THIS TIME...GENERALLY MINOR
FLOODING IS ANTICIPATED WITH WATER LEVELS BELOW LAST WEEKS CREST.
CONTINUED MINOR FLOODING IS STILL ANTICIPATED ON THE CACHE LA
POUDRE IN WESTERN WELD COUNTY THROUGH EARLY NEXT WEEK.
NO APPRECIABLE RAIN HAS FALLEN IN THE PAST 36-48 HOURS SO THE
RIVERS SHOULD CONTINUE A SLOW DECREASE THROUGH THIS EVENING EXCEPT
FOR THE FLOOD CREST MOVING DOWN THE SOUTH PLATTE WHICH WILL MOVE
THROUGH FORT MORGAN AFTER MIDNIGHT.
ANOTHER ORGANIZED SHORTWAVE WILL MOVE THROUGH THE REGION TONIGHT
WITH MORE LIGHT TO MODERATE RAIN AND SOME EMBEDDED
THUNDERSHOWERS. TOTAL LIQUID PRECIPITATION IS EXPECTED TO RANGE
FROM .25 TO .75 INCHES ON THE PLAINS WITH UPWARDS OF AN INCH
POSSIBLE IN THE MOUNTAINS AND HIGHER FOOTHILLS. ALTHOUGH THESE
AMOUNTS DO NOT SEEM LARGE...THE SATURATED GROUND CONDITIONS
SHOULD RESULT IN EFFICIENT RUNOFF. RIVERS AND STREAMS THAT ARE
ALREADY RUNNING HIGH WILL CONTINUE TO DO SO.
SATURDAY WILL HAVE POTENTIAL FOR STRONGER THUNDERSTORMS WITH
HEAVY RAINFALL AND A FLASH FLOOD THREAT. PRECIPITABLE WATER
VALUES NEAR 0.70 TO 0.90 INCH ON THE PLAINS AND ANY STRONGER DEEP
CONVECTION THAT DEVELOPS WOULD SUPPORT POTENTIAL FOR QUICK 1 TO
1.5 INCH RAINFALL AMOUNTS FROM THE ISOLATED STRONGER STORMS. FLASH
FLOOD GUIDANCE CONTINUES TO DROP WITH ADDITIONAL RAINFALL AND SOIL
SATURATION. SUNDAY MAY ALSO SEE SOME THREAT OF LOCALIZED FLASH
FLOODING BUT MOISTURE LEVELS AND INSTABILITY WILL BE LESS THAN
SATURDAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM MDT FRIDAY FOR COZ034.
&&
$$
SHORT TERM...DANKERS
LONG TERM...BARJENBRUCH
AVIATION...DANKERS
HYDROLOGY...BARJENBRUCH/DANKERS
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1141 PM MDT WED MAY 20 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 328 PM MDT WED MAY 20 2015
CURRENT WATER VAPOR IMAGERY AND UPPER AIR ANALYSIS INDICATING A
UPPER RIDGING BUILDING ACROSS THE STATE WITH A BROAD UPPER TROUGH
DIGGING ACROSS THE WEST COAST. WATER VAPOR IMAGERY ALSO INDICATING
AN EMBEDDED SHORT WAVE LIFTING OUT ACROSS THE SOUTHERN GREAT BASIN
WITH ANOTHER ONE ROUNDING THE BASE OF THE TROUGH ACROSS THE SOUTHERN
CALIF COAST ATTM. WARMING ALOFT AND MOIST LOW LEVEL UPSLOPE KEEPING
LOW CLOUDS TRAPPED AND COOL TEMPERATURES IN THE 40S AND 50S ACROSS
THE EASTERN PLAINS AT THIS TIME. REGIONAL SATELLITE AND RADAR DATA
INDICATING INSOLATION ACROSS THE HIGHER TERRAIN TERRAIN WEST OF THE
FRONT RANGE IS HELPING TO DEVELOP ISOLATED SHOWERS AND A FEW
EMBEDDED THUNDERSTORMS THROUGH THE EARLY AFTERNOON...WITH THE BEST
COVERAGE ACROSS THE NORTHERN AND CENTRAL MTS.
TONIGHT...TRANSITORY UPPER RIDGE CONTINUES TO BUILD ACROSS THE STATE
WITH THE PASSING GREAT BASIN EMBEDDED WAVE HELPING TO DEVELOP
CONVECTION THROUGH THE LATE EVENING HOURS...MAINLY OVER THE HIGHER
TERRAIN. LATEST NAM...GFS AND EC ARE BULLISH WITH BRINGING SHOWERS
ACROSS THE STABLE I-25 CORRIDOR...AND HAVE STAYED CLOSER TO THE HRRR
AND RAP WHICH KEEPS BEST CHANCES OF GENERALLY LIGHT RAIN ACROSS EL
PASO COUNTY. MODEL SOUNDINGS INDICATING CLOUDS TO LOWER ACROSS THE
PLAINS AGAIN OVERNIGHT...WITH FOG AND PATCHY DRIZZLE POSSIBLE ALONG
AND WEST OF THE I-25 CORRIDOR.
THURSDAY...SOUTHERLY FLOW ALOFT INCREASES THROUGH THE DAY AS THE
WEST COAST SYSTEM SLOWLY MOVES EAST. LATEST MODELS ARE A TAD SLOWLY
WITH THE SOUTHERN CALIF SHORT WAVE LIFTING OUT ACROSS THE DESERT
SOUTHWEST AND INTO THE ROCKIES...WHICH MAY DELAY THE
ONSET...COVERAGE AND INTENSITY OF SHOWERS AND THUNDERSTORMS ACROSS
THE AREA. AT ANY RATE...WILL SEE SHOWERS AND STORMS DEVELOPING
ACROSS THE HIGHER TERRAIN THROUGH THE AFTERNOON WITH STORMS MOVING
ACROSS THE ADJACENT PLAINS THROUGH THE LATE AFTERNOON AND EARLY
EVENING. SLOWER MOVEMENT OF THE SYSTEM LOOKS TO HINDER MIXING ACROSS
THE EASTERN PLAINS...WITH LOW CLOUDS SLOWLY LIFTING THROUGH THE LATE
MORNING AND AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 328 PM MDT WED MAY 20 2015
THURSDAY NIGHT AND FRIDAY...AN UPPER LEVEL STORM SYSTEM ACROSS THE
SOUTHWEST US IS FORECAST TO EJECT A RATHER STRONG SHORTWAVE TROUGH
INTO COLORADO. SURFACE FLOW FROM THE SOUTHEAST WITH BRING IN A DEEP
LAYER OF MOISTURE...WHICH WILL BE LIFTED BY THE TERRAIN AND
SHORTWAVE DYNAMICS TO PRODUCE ANOTHER EPISODE OF WIDESPREAD
MODERATE...AND LOCALLY HEAVY RAINFALL TO THE EASTERN MOUNTAINS AND
PLAINS. THE SHOWERS AND STORMS ARE DEPICTED BY THE GFS AND NAM TO
MAINLY OCCUR DURING THE FIRST HALF OF THURSDAY NIGHT...AND QUICKLY
SPREAD NORTH AND EAST DURING THE OVERNIGHT. A FEW LIGHTNING STRIKES
ARE POSSIBLE ACROSS THE CWA WITH ELEVATED INSTABILITY...HOWEVER
SEVERE WEATHER IS UNLIKELY THROUGH THURSDAY NIGHT. GFS IS MORE HEAVY
HANDED WITH PRECIPITATION ACROSS THE I-25 AND EASTERN MOUNTAINS THAN
THE NAM ON THE LATEST RUNS. MORE THAN AN INCH OF RAIN IS POSSIBLE
OVER THE EASTERN HALF OF THE CWA...WITH LOCALLY HIGHER AMOUNTS. WITH
SATURATED GROUND...THE POTENTIAL FOR FLASH FLOODING AND FLOODING IS
THERE. RIVERS AND LARGE CREEKS MAY ALSO EXPERIENCE MORE EROSION
ISSUES. SNOW LEVELS WILL REMAIN HIGH...WITH SEVERAL INCHES OF SNOW
POSSIBLE THROUGH FRIDAY MORNING ABOVE 10 KFT.
IN THE WAKE OF THE SHORTWAVE...SINKING MOTION AND DRYING WILL OCCUR.
MODELS ARE HINTING AT A DRY LINE ACROSS THE FAR EASTERN
PLAINS...WHICH COULD SPARK STRONG TO SEVERE STORMS NEAR THE KANSAS
BORDER. CAPES OVER 1000 J/KG AND 0-6 KM BULK SHEARS ABOVE 50 KNOTS
COULD CAUSE SOME STORM ROTATION. ELSEWHERE ON FRIDAY...ISOLATED
SHOWERS AND STORMS WILL OCCUR ACROSS THE MOUNTAINS FRIDAY AFTERNOON
AND DISSIPATE FRIDAY EVENING.
SATURDAY...THE MAIN UPPER SYSTEM WILL MIGRATE THROUGH THE GREAT
BASIN...WITH SOUTH-SOUTHWEST FLOW ACROSS THE CWA. ISOLATED TO
SCATTERED SHOWERS AND STORMS MAY DEVELOP ACROSS THE MOUNTAINS AND
HIGH VALLEYS...AND THE DRY LINE IS FORECAST TO BE ACROSS THE EASTERN
COUNTIES AGAIN...WITH A RISK OF STRONG TO MARGINALLY SEVERE STORMS
DURING THE AFTERNOON AND EVENING.
SUNDAY AND MONDAY...THE NEXT SYSTEM WILL MOVE ACROSS THE ROCKIES
SUNDAY INTO MONDAY. A WEAK COLD FRONT WILL PUSH THROUGH THE PLAINS
SUNDAY MORNING BRINGING MOISTURE INTO THE REGION. AN UPPER
DISTURBANCE WILL BRING SOME SHOWERS AND STORM TO THE AREA...LASTING
INTO MONDAY AFTERNOON.
TUESDAY AND WEDNESDAY...A MODEST RIDGE MAY BUILD INTO THE
AREA...PROVIDING SOME SUNSHINE...AND ONLY THE POSSIBILITY OF
AFTERNOON AND EVENING ISOLATED SHOWERS AND STORMS. -TLM-
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1137 PM MDT WED MAY 20 2015
UPSLOPE FLOW CONTINUES OVER THE PLAINS OVERNIGHT AND INTO THE
MORNING THURSDAY...WITH IFR/LIFR CONDITIONS AT KCOS AND KPUB IN
FOG AND DRIZZLE UNTIL MIDMORNING. CIGS AND VIS GRADUALLY IMPROVE
DURING THE DAY...THOUGH CONDITIONS WILL LIKELY STAY MVFR OR WORSE
ALL DAY. SHOWERS WILL REDEVELOP AND LAST INTO THE EVENING WITH
FAIRLY WIDESPREAD IFR AGAIN THU EVENING OVER THE MOUNTAINS AND
PLAINS.
AT KALS...VFR CONDITIONS PREVAIL OVERNIGHT AND DURING THE DAY THU
WITH AN INCREASING CHANCE OF -SHRA/-TSRA AFTER 18Z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MW
LONG TERM...TM
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
746 AM EDT THU MAY 21 2015
.SYNOPSIS...
WEAK HIGH PRESSURE QUICKLY MOVES EAST TODAY...GIVING WAY TO LOW
PRESSURE THAT PASSES TO THE SOUTH AND EAST TONIGHT. A COLD FRONT
MOVES THROUGH LATE FRIDAY. HIGH PRESSURE BUILDS ACROSS THE AREA
ON SATURDAY...THEN MOVES OFFSHORE EARLY SUNDAY. A WARM FRONT WILL
THEN SLOWLY APPROACH FROM THE SOUTHWEST LATE SUNDAY THROUGH
TUESDAY. THE FRONT MAY LIFT TO THE NORTH WEDNESDAY MORNING...AND
BE FOLLOWED BY A COLD FRONT LATER WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST SEEMS ON TRACK. MADE MINOR ADJUSTMENTS TO TEMPERATURE AND
DEWPOINT TO REFLECT LATEST SURFACE OBSERVATIONS. OTHERWISE...PLENTY
OF MID AND HIGH LEVEL CLOUDS THIS MORNING OUT AHEAD OF UPSTREAM
SHORTWAVE WILL LOWER AND THICKEN AS THE DAY PROGRESSES.
THERE COULD BE A FEW PEEKS OF SUN EARLY...BUT MAINLY CLOUDY
CONDITIONS ARE ANTICIPATED.
AT THE SFC...LOW PRESSURE OVER THE APPALACHIANS TO OUR SOUTH WILL
MOVE TOWARD THE MID ATLANTIC COAST LATE TODAY AHEAD OF THE
SHORTWAVE.
SOUTHWEST ZONES...THEN COASTAL ZONES FROM NYC EAST COULD SEE LIGHT
RAIN MOVE IN THIS AFTERNOON. LATEST HRRR SIMULATED
REFLECTIVITY...ALONG WITH HIGH RES ARW/NMM...DOES FORECAST RAIN TO
APPROACH THE AREA...AND CLIP THE SW ZONES THIS AFTERNOON. WILL
MAINTAIN CHANCE POPS DURING THE AFTERNOON...WITH A GENERAL
LOWERING OF POPS AS YOU HEAD NORTHWARD.
WITH PLENTY OF CLOUD COVER IN PLACE...TEMPS WILL STRUGGLE THROUGH
THE 50S...AND INTO THE LOWER 60S. THIS IS BELOW NORMAL BY 5 TO 10
DEGREES...AND IS SUPPORTED BY LATEST MOS NUMBERS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
LARGE UPPER TROUGH/LOW PRESSURE OVER EASTERN CANADA...WITH
SHORTWAVE ENERGY PIN-WHEELING AROUND THE CLOSED LOW...WILL PREVAIL
THIS TIME FRAME.
STRENGTHENING SHORTWAVE ROUNDING THE BASE OF THE LARGE UPPER TROUGH
QUICKLY TRAVERSES FROM WEST TO EAST TONIGHT...PASSING TO THE EAST OF
THE AREA EARLY FRIDAY MORNING. IN RESPONSE...SFC LOW OFF THE MID
ATLANTIC COAST IS EXPECTED TO DEEPEN SLIGHTLY...LOWERING A FEW
MILLIBARS...AS IT TRACKS SOMEWHERE JUST SOUTH AND EAST OF THE
40N/70W BENCHMARK TONIGHT INTO EARLY FRIDAY. IN FACT...CONSENSUS IS
OBSERVED IN LATEST NAM/GFS/SREF MEAN AND ECMWF WITH HANDLING OF THIS
LOW.
PRECIP SHIELD EXTENDS NORTH AND WEST OF THIS SFC LOW...AND EXPANDS
AHEAD OF THE AFOREMENTIONED SHORTWAVE.
AS FOR POPS...WILL CONTINUE TO CARRY HIGH CHANCE TO LIKELY POPS NEAR
THE COAST. THIS BASED ON ANALYSIS OF GFS AND NAM STATISTICAL
MOS...NCEP MODEL PLAN FIELDS...AND SREF PLUMES. IN GENERAL...COASTAL
LOCALES TONIGHT COULD OBSERVE ANYWHERE FROM AROUND A TENTH OF AN
INCH ON AVERAGE. ACROSS NORTHERN ZONES SUCH AS THE LOWER HUDSON
VALLEY AND SW CT...POPS REMAIN LOWER AND QPF WOULD RANGE FROM A
TRACE TO MAYBE A TENTH OF AN INCH.
ANY RAIN DEPARTS EARLY FRIDAY...WITH DRY WEATHER EXPECTED THROUGH
THE MORNING. CLOUDS GIVE WAY TO BRIEF SUNSHINE. BY AFTERNOON...A
COLD FRONT AHEAD OF DIGGING TROUGH APPROACHES LATE. CLOUDS INCREASE
AGAIN...AND A FEW SHOWERS ARE POSSIBLE. NAM MOST AGGRESSIVE IN
DEVELOPING AT LEAST SCATTERED COVERAGE DURING THE LATE AFTERNOON
HOURS...BUT WILL LEAN TOWARD SREF/ECMWF/GFS AND ONLY FORECAST
SLIGHT CHANCE POPS ATTM.
A COOL NIGHT IS EXPECTED TONIGHT...WITH LOWS IN THE 40S TO LOWER
50S. WEST FLOW AND BRIEF WAA FRIDAY WILL RESULT IN NEAR TO
PERHAPS SLIGHTLY ABOVE NORMAL TEMPS IN THE 70 TO 75 DEGREE RANGE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
PLEASANT WEATHER CONDITIONS ARE EXPECTED FOR THE WEEKEND AS HIGH
PRESSURE BUILDS ACROSS THE AREA ON SATURDAY...THEN OFFSHORE SUNDAY
MORNING. HIGH TEMPERATURES ON SATURDAY WILL BE IN THE MID TO UPPER
60S AND LOW TO MID 70S ON SUNDAY. A WARM FRONT LIFTS NORTH ON MONDAY
BRINGING A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS. INSTABILITY
SLOWLY INCREASES THROUGH THIS TIME...SO MENTIONED CHANCE THUNDER ON
TUESDAY FROM NYC NORTH/WEST. THE WARM FRONT SHOULD LIFT TO THE NE BY
WEDNESDAY MORNING...BUT COULD BE FOLLOWED BY A WEAK COLD FRONT OR
PRE-FRONTAL WEDNESDAY AFTERNOON INTO THURSDAY MORNING...WITH CHANCE
OF AFTERNOON SHOWERS AND THUNDERSTORMS ONCE AGAIN WEDNESDAY AND
THURSDAY.
TEMPERATURES WILL SLOWLY WARM UP DURING THE WEEK. WITH TEMPERATURES
STARTING OUT IN THE LOW TO MID 70S ON MONDAY...THEN LOW TO MID 80S
BY MIDWEEK.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
WEAK HIGH PRESSURE GIVES WAY TO LOW PRESSURE PASSING WELL SOUTH
AND EAST OF LONG ISLAND THROUGH TONIGHT.
EXPECTING MAINLY VFR CONDITIONS...ALTHOUGH MVFR CANNOT TOTALLY BE
RULED OUT AT TIMES DURING THE LIGHT RAIN LATER TODAY AND THIS
EVENING.
WINDS WILL BECOME MORE SOUTHERLY AT 10-15 KT BEFORE RETURNING TO
A MORE NORTHERLY FLOW LATE TONIGHT WHICH WILL AGAIN LOWER TO LESS
THAN 10 KT.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
21Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KLGA FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
21Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KEWR FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
21Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
23Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KHPN FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
03Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KISP FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
22Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRI-FRI NIGHT...POSSIBLE MVFR EARLY MORNING AND IN AFTERNOON.
OTHERWISE VFR. NW GUSTS 25-30 KT...LOWERING AT NIGHT WITH GUSTS
15-20 KT.
.SAT-SUN NIGHT...VFR. W GUSTS 15-20 KT DURING DAY SAT. SW GUSTS
15-25 KT DURING DAY SUN AND INTO EARLY SUN EVE.
.MON...POSSIBLE MVFR OR LOWER IN RAIN SHOWERS.
&&
.MARINE...
HIGH PRESSURE BRIEFLY BUILDS ACROSS THE WATERS TODAY. AS
SUCH...TRANQUIL WINDS AND SEAS ARE FORECAST. BY TONIGHT...THE HIGH
DEPARTS AND LOW PRESSURE APPROACHES AND TRACKS SOUTH AND EAST OF THE
WATERS. THIS LOW MOVES NORTHEAST AS A COLD FRONT APPROACHES FRIDAY
AFTERNOON. LIGHT NORTHERLY WINDS TONIGHT INTO FRIDAY MORNING TURN
TOWARD BACK TO THE WEST AND INCREASE DURING THE AFTERNOON. THERE
COULD VERY WELL BE 25 TO PERHAPS 30 KT GUSTS NEAR SHORE LATE IN
THE AFTERNOON...ESPECIALLY NY HARBOR AND WESTERN LI SOUND. WILL
HOLD OFF THOUGH ON ANY ADVISORIES ATTM DUE TO LATE 3RD
PERIOD...AND MAINLY A NEAR SHORE CONCERN.
TRANQUIL SEAS TONIGHT BUILDS LATE FRIDAY AFTERNOON IN RESPONSE TO
THE STRENGTHENING WESTERLY WINDS.
TRANQUIL CONDITIONS ARE EXPECTED SATURDAY AND SUNDAY MORNING...AS
HIGH PRESSURE BUILDS ACROSS THE AREA WATERS. SOUTHWEST FLOW
INCREASING TO 15-20 KT MAY BUILD OCEAN SEAS TO 5 FT SUNDAY
AFTERNOON/EVENING...ESPECIALLY FARTHER EAST WHERE A LONGER FETCH
WILL EXIST. OCEAN SEAS FALL BELOW SCA LEVELS BRIEFLY ON
MONDAY...THEN BUILD BACK TO SCA LEVELS ON TUESDAY.
&&
.FIRE WEATHER...
TODAY WILL REMAIN MAINLY CLOUDY AND COOL WITH LIGHT WINDS. SOME RAIN
IS EXPECTED LATE TODAY AND THROUGH TONIGHT...MAINLY ALONG THE COAST.
THEN...DRY WEATHER RETURNS FRIDAY. WEATHER CONDITIONS ON FRIDAY MAY
STILL BE CONDUCIVE TO GROWTH/SPREAD OF ANY FIRES THAT DEVELOP. MIN
RH ARE FORECAST TO BE IN THE 20S AND W-NW WINDS WILL GUST TO 25-30
MPH FRI AFTERNOON. KBDI IS IN THE 100S ACROSS MOST OF SRN CT AND THE
LOWER HUDSON VALLEY AND IN THE 200S ACROSS NYC METRO AND LONG
ISLAND...BUT MAY NOT BE FULLY REPRESENTATIVE OF THE PERSISTENT DRY
CONDITIONS THAT HAVE BEEN IN PLACE.
&&
.HYDROLOGY...
DRY THROUGH THIS MORNING. THEN THERE IS THE POTENTIAL
FOR AROUND A TENTH OF AN INCH OF RAIN ON AVERAGE NEAR THE COAST.
NORTHERN ZONES SUCH AS THE LOWER HUDSON VALLEY AND SRN CT...QPF
WOULD RANGE FROM A TRACE TO MAYBE A TENTH OF AN INCH.
THERE IS A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS MONDAY
INTO THE MIDDLE OF THE WEEK. MODEL UNCERTAINTIES ON
TIMING/PLACEMENT OF ANY HEAVY RAIN ARE STILL TOO LARGE TO MERIT
MENTION OF SPECIFIC AMOUNTS...AND MAY NOT EVEN PAN PER MODEL
FORECASTS OUT GIVEN THE PERSISTENT DRY PATTERN THAT HAS BEEN IN
PLACE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
504 AM EDT THU MAY 21 2015
.SYNOPSIS...
WEAK HIGH PRESSURE QUICKLY MOVES EAST TODAY...GIVING WAY TO LOW
PRESSURE THAT PASSES TO THE SOUTH AND EAST TONIGHT. A COLD FRONT
MOVES THROUGH LATE FRIDAY. HIGH PRESSURE BUILDS ACROSS THE AREA
ON SATURDAY...THEN MOVES OFFSHORE EARLY SUNDAY. A WARM FRONT WILL
THEN SLOWLY APPROACH FROM THE SOUTHWEST LATE SUNDAY THROUGH
TUESDAY. THE FRONT MAY LIFT TO THE NORTH WEDNESDAY MORNING...AND
BE FOLLOWED BY A COLD FRONT LATER WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PLENTY OF MID AND HIGH LEVEL CLOUDS THIS MORNING OUT AHEAD OF
UPSTREAM SHORTWAVE WILL LOWER AND THICKEN AS THE DAY PROGRESSES.
THERE COULD BE A FEW PEEKS OF SUN EARLY...BUT MAINLY CLOUDY
CONDITIONS ARE ANTICIPATED.
AT THE SFC...LOW PRESSURE OVER THE APPALACHIANS TO OUR SOUTH WILL
MOVE TOWARD THE MID ATLANTIC COAST LATE TODAY AHEAD OF THE
SHORTWAVE.
SOUTHWEST ZONES...THEN COASTAL ZONES FROM NYC EAST COULD SEE LIGHT
RAIN MOVE IN THIS AFTERNOON. LATEST HRRR SIMULATED
REFLECTIVITY...ALONG WITH HIGH RES ARW/NMM...DOES FORECAST RAIN TO
APPROACH THE AREA...AND CLIP THE SW ZONES THIS AFTERNOON. WILL
MAINTAIN CHANCE POPS DURING THE AFTERNOON...WITH A GENERAL
LOWERING OF POPS AS YOU HEAD NORTHWARD.
WITH PLENTY OF CLOUD COVER IN PLACE...TEMPS WILL STRUGGLE THROUGH
THE 50S...AND INTO THE LOWER 60S. THIS IS BELOW NORMAL BY 5 TO 10
DEGREES...AND IS SUPPORTED BY LATEST MOS NUMBERS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
LARGE UPPER TROUGH/LOW PRESSURE OVER EASTERN CANADA...WITH
SHORTWAVE ENERGY PIN-WHEELING AROUND THE CLOSED LOW...WILL PREVAIL
THIS TIME FRAME.
STRENGTHENING SHORTWAVE ROUNDING THE BASE OF THE LARGE UPPER TROUGH
QUICKLY TRAVERSES FROM WEST TO EAST TONIGHT...PASSING TO THE EAST OF
THE AREA EARLY FRIDAY MORNING. IN RESPONSE...SFC LOW OFF THE MID
ATLANTIC COAST IS EXPECTED TO DEEPEN SLIGHTLY...LOWERING A FEW
MILLIBARS...AS IT TRACKS SOMEWHERE JUST SOUTH AND EAST OF THE
40N/70W BENCHMARK TONIGHT INTO EARLY FRIDAY. IN FACT...CONSENSUS IS
OBSERVED IN LATEST NAM/GFS/SREF MEAN AND ECMWF WITH HANDLING OF THIS
LOW.
PRECIP SHIELD EXTENDS NORTH AND WEST OF THIS SFC LOW...AND EXPANDS
AHEAD OF THE AFOREMENTIONED SHORTWAVE.
AS FOR POPS...WILL CONTINUE TO CARRY HIGH CHANCE TO LIKELY POPS NEAR
THE COAST. THIS BASED ON ANALYSIS OF GFS AND NAM STATISTICAL
MOS...NCEP MODEL PLAN FIELDS...AND SREF PLUMES. IN GENERAL...COASTAL
LOCALES TONIGHT COULD OBSERVE ANYWHERE FROM AROUND A TENTH OF AN
INCH ON AVERAGE. ACROSS NORTHERN ZONES SUCH AS THE LOWER HUDSON
VALLEY AND SW CT...POPS REMAIN LOWER AND QPF WOULD RANGE FROM A
TRACE TO MAYBE A TENTH OF AN INCH.
ANY RAIN DEPARTS EARLY FRIDAY...WITH DRY WEATHER EXPECTED THROUGH
THE MORNING. CLOUDS GIVE WAY TO BRIEF SUNSHINE. BY AFTERNOON...A
COLD FRONT AHEAD OF DIGGING TROUGH APPROACHES LATE. CLOUDS INCREASE
AGAIN...AND A FEW SHOWERS ARE POSSIBLE. NAM MOST AGGRESSIVE IN
DEVELOPING AT LEAST SCATTERED COVERAGE DURING THE LATE AFTERNOON
HOURS...BUT WILL LEAN TOWARD SREF/ECMWF/GFS AND ONLY FORECAST
SLIGHT CHANCE POPS ATTM.
A COOL NIGHT IS EXPECTED TONIGHT...WITH LOWS IN THE 40S TO LOWER
50S. WEST FLOW AND BRIEF WAA FRIDAY WILL RESULT IN NEAR TO
PERHAPS SLIGHTLY ABOVE NORMAL TEMPS IN THE 70 TO 75 DEGREE RANGE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
PLEASANT WEATHER CONDITIONS ARE EXPECTED FOR THE WEEKEND AS HIGH
PRESSURE BUILDS ACROSS THE AREA ON SATURDAY...THEN OFFSHORE SUNDAY
MORNING. HIGH TEMPERATURES ON SATURDAY WILL BE IN THE MID TO UPPER
60S AND LOW TO MID 70S ON SUNDAY. A WARM FRONT LIFTS NORTH ON MONDAY
BRINGING A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS. INSTABILITY
SLOWLY INCREASES THROUGH THIS TIME...SO MENTIONED CHANCE THUNDER ON
TUESDAY FROM NYC NORTH/WEST. THE WARM FRONT SHOULD LIFT TO THE NE BY
WEDNESDAY MORNING...BUT COULD BE FOLLOWED BY A WEAK COLD FRONT OR
PRE-FRONTAL WEDNESDAY AFTERNOON INTO THURSDAY MORNING...WITH CHANCE
OF AFTERNOON SHOWERS AND THUNDERSTORMS ONCE AGAIN WEDNESDAY AND
THURSDAY.
TEMPERATURES WILL SLOWLY WARM UP DURING THE WEEK. WITH TEMPERATURES
STARTING OUT IN THE LOW TO MID 70S ON MONDAY...THEN LOW TO MID 80S
BY MIDWEEK.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
WEAK HIGH PRESSURE GIVES WAY TO LOW PRESSURE PASSING WELL SOUTH
AND EAST OF LONG ISLAND THROUGH TONIGHT.
EXPECTING MAINLY VFR CONDITIONS...ALTHOUGH MVFR CANNOT TOTALLY BE
RULED OUT AT TIMES DURING THE LIGHT RAIN LATER TODAY AND THIS
EVENING.
A GENERAL NORTHERLY FLOW LESS THAN 10 KT WILL BECOME MORE
SOUTHERLY AT 10-15 KT BEFORE RETURNING TO A MORE NORTHERLY FLOW
LATE TONIGHT WHICH WILL AGAIN LOWER TO LESS THAN 10 KT.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
21Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KLGA FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
21Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KEWR FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
21Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
23Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KHPN FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
23Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KISP FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
21Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
.OUTLOOK FOR 09Z FRIDAY THROUGH MONDAY...
.FRI-FRI NIGHT...POSSIBLE MVFR EARLY MORNING AND IN AFTERNOON.
OTHERWISE VFR. NW GUSTS 25-30 KT...LOWERING AT NIGHT WITH GUSTS
15-20 KT.
.SAT-SUN NIGHT...VFR. W GUSTS 15-20 KT DURING DAY SAT. SW GUSTS
15-25 KT DURING DAY SUN AND INTO EARLY SUN EVE.
.MON...POSSIBLE MVFR OR LOWER IN RAIN SHOWERS.
&&
.MARINE...
HIGH PRESSURE BRIEFLY BUILDS ACROSS THE WATERS TODAY. AS
SUCH...TRANQUIL WINDS AND SEAS ARE FORECAST. BY TONIGHT...THE HIGH
DEPARTS AND LOW PRESSURE APPROACHES AND TRACKS SOUTH AND EAST OF THE
WATERS. THIS LOW MOVES NORTHEAST AS A COLD FRONT APPROACHES FRIDAY
AFTERNOON. LIGHT NORTHERLY WINDS TONIGHT INTO FRIDAY MORNING TURN
TOWARD BACK TO THE WEST AND INCREASE DURING THE AFTERNOON. THERE
COULD VERY WELL BE 25 TO PERHAPS 30 KT GUSTS NEAR SHORE LATE IN
THE AFTERNOON...ESPECIALLY NY HARBOR AND WESTERN LI SOUND. WILL
HOLD OFF THOUGH ON ANY ADVISORIES ATTM DUE TO LATE 3RD
PERIOD...AND MAINLY A NEAR SHORE CONCERN.
TRANQUIL SEAS TONIGHT BUILDS LATE FRIDAY AFTERNOON IN RESPONSE TO
THE STRENGTHENING WESTERLY WINDS.
TRANQUIL CONDITIONS ARE EXPECTED SATURDAY AND SUNDAY MORNING...AS
HIGH PRESSURE BUILDS ACROSS THE AREA WATERS. SOUTHWEST FLOW
INCREASING TO 15-20 KT MAY BUILD OCEAN SEAS TO 5 FT SUNDAY
AFTERNOON/EVENING...ESPECIALLY FARTHER EAST WHERE A LONGER FETCH
WILL EXIST. OCEAN SEAS FALL BELOW SCA LEVELS BRIEFLY ON
MONDAY...THEN BUILD BACK TO SCA LEVELS ON TUESDAY.
&&
.FIRE WEATHER...
TODAY WILL REMAIN MAINLY CLOUDY AND COOL WITH LIGHT WINDS. SOME RAIN
IS EXPECTED LATE TODAY AND THROUGH TONIGHT...MAINLY ALONG THE COAST.
THEN...DRY WEATHER RETURNS FRIDAY. WEATHER CONDITIONS ON FRIDAY MAY
STILL BE CONDUCIVE TO GROWTH/SPREAD OF ANY FIRES THAT DEVELOP. MIN
RH ARE FORECAST TO BE IN THE 20S AND W-NW WINDS WILL GUST TO 25-30
MPH FRI AFTERNOON. KBDI IS IN THE 100S ACROSS MOST OF SRN CT AND THE
LOWER HUDSON VALLEY AND IN THE 200S ACROSS NYC METRO AND LONG
ISLAND...BUT MAY NOT BE FULLY REPRESENTATIVE OF THE PERSISTENT DRY
CONDITIONS THAT HAVE BEEN IN PLACE.
&&
.HYDROLOGY...
DRY THROUGH THIS MORNING. THEN THERE IS THE POTENTIAL
FOR AROUND A TENTH OF AN INCH OF RAIN ON AVERAGE NEAR THE COAST.
NORTHERN ZONES SUCH AS THE LOWER HUDSON VALLEY AND SRN CT...QPF
WOULD RANGE FROM A TRACE TO MAYBE A TENTH OF AN INCH.
THERE IS A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS MONDAY
INTO THE MIDDLE OF THE WEEK. MODEL UNCERTAINTIES ON
TIMING/PLACEMENT OF ANY HEAVY RAIN ARE STILL TOO LARGE TO MERIT
MENTION OF SPECIFIC AMOUNTS...AND MAY NOT EVEN PAN PER MODEL
FORECASTS OUT GIVEN THE PERSISTENT DRY PATTERN THAT HAS BEEN IN
PLACE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FIG/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...FIG
AVIATION...JM
MARINE...FIG/PW
FIRE WEATHER...
HYDROLOGY...FIG/PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
338 AM EDT THU MAY 21 2015
.SYNOPSIS...
WEAK HIGH PRESSURE QUICKLY MOVES EAST TODAY...GIVING WAY TO LOW
PRESSURE THAT PASSES TO THE SOUTH AND EAST TONIGHT. A COLD FRONT
MOVES THROUGH LATE FRIDAY. HIGH PRESSURE BUILDS ACROSS THE AREA
ON SATURDAY...THEN MOVES OFFSHORE EARLY SUNDAY. A WARM FRONT WILL
THEN SLOWLY APPROACH FROM THE SOUTHWEST LATE SUNDAY THROUGH
TUESDAY. THE FRONT MAY LIFT TO THE NORTH WEDNESDAY MORNING...AND
BE FOLLOWED BY A COLD FRONT LATER WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PLENTY OF MID AND HIGH LEVEL CLOUDS THIS MORNING OUT AHEAD OF
UPSTREAM SHORTWAVE WILL LOWER AND THICKEN AS THE DAY PROGRESSES.
THERE COULD BE A FEW PEEKS OF SUN EARLY...BUT MAINLY CLOUDY
CONDITIONS ARE ANTICIPATED.
AT THE SFC...LOW PRESSURE OVER THE APPALACHIANS TO OUR SOUTH WILL
MOVE TOWARD THE MID ATLANTIC COAST LATE TODAY AHEAD OF THE
SHORTWAVE.
SOUTHWEST ZONES...THEN COASTAL ZONES FROM NYC EAST COULD SEE LIGHT
RAIN MOVE IN THIS AFTERNOON. LATEST HRRR SIMULATED
REFLECTIVITY...ALONG WITH HIGH RES ARW/NMM...DOES FORECAST RAIN TO
APPROACH THE AREA...AND CLIP THE SW ZONES THIS AFTERNOON. WILL
MAINTAIN CHANCE POPS DURING THE AFTERNOON...WITH A GENERAL
LOWERING OF POPS AS YOU HEAD NORTHWARD.
WITH PLENTY OF CLOUD COVER IN PLACE...TEMPS WILL STRUGGLE THROUGH
THE 50S...AND INTO THE LOWER 60S. THIS IS BELOW NORMAL BY 5 TO 10
DEGREES...AND IS SUPPORTED BY LATEST MOS NUMBERS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
LARGE UPPER TROUGH/LOW PRESSURE OVER EASTERN CANADA...WITH
SHORTWAVE ENERGY PIN-WHEELING AROUND THE CLOSED LOW...WILL PREVAIL
THIS TIME FRAME.
STRENGTHENING SHORTWAVE ROUNDING THE BASE OF THE LARGE UPPER TROUGH
QUICKLY TRAVERSES FROM WEST TO EAST TONIGHT...PASSING TO THE EAST OF
THE AREA EARLY FRIDAY MORNING. IN RESPONSE...SFC LOW OFF THE MID
ATLANTIC COAST IS EXPECTED TO DEEPEN SLIGHTLY...LOWERING A FEW
MILLIBARS...AS IT TRACKS SOMEWHERE JUST SOUTH AND EAST OF THE
40N/70W BENCHMARK TONIGHT INTO EARLY FRIDAY. IN FACT...CONSENSUS IS
OBSERVED IN LATEST NAM/GFS/SREF MEAN AND ECMWF WITH HANDLING OF THIS
LOW.
PRECIP SHIELD EXTENDS NORTH AND WEST OF THIS SFC LOW...AND EXPANDS
AHEAD OF THE AFOREMENTIONED SHORTWAVE.
AS FOR POPS...WILL CONTINUE TO CARRY HIGH CHANCE TO LIKELY POPS NEAR
THE COAST. THIS BASED ON ANALYSIS OF GFS AND NAM STATISTICAL
MOS...NCEP MODEL PLAN FIELDS...AND SREF PLUMES. IN GENERAL...COASTAL
LOCALES TONIGHT COULD OBSERVE ANYWHERE FROM AROUND A TENTH OF AN
INCH ON AVERAGE. ACROSS NORTHERN ZONES SUCH AS THE LOWER HUDSON
VALLEY AND SW CT...POPS REMAIN LOWER AND QPF WOULD RANGE FROM A
TRACE TO MAYBE A TENTH OF AN INCH.
ANY RAIN DEPARTS EARLY FRIDAY...WITH DRY WEATHER EXPECTED THROUGH
THE MORNING. CLOUDS GIVE WAY TO BRIEF SUNSHINE. BY AFTERNOON...A
COLD FRONT AHEAD OF DIGGING TROUGH APPROACHES LATE. CLOUDS INCREASE
AGAIN...AND A FEW SHOWERS ARE POSSIBLE. NAM MOST AGGRESSIVE IN
DEVELOPING AT LEAST SCATTERED COVERAGE DURING THE LATE AFTERNOON
HOURS...BUT WILL LEAN TOWARD SREF/ECMWF/GFS AND ONLY FORECAST
SLIGHT CHANCE POPS ATTM.
A COOL NIGHT IS EXPECTED TONIGHT...WITH LOWS IN THE 40S TO LOWER
50S. WEST FLOW AND BRIEF WAA FRIDAY WILL RESULT IN NEAR TO
PERHAPS SLIGHTLY ABOVE NORMAL TEMPS IN THE 70 TO 75 DEGREE RANGE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
PLEASANT WEATHER CONDITIONS ARE EXPECTED FOR THE WEEKEND AS HIGH
PRESSURE BUILDS ACROSS THE AREA ON SATURDAY...THEN OFFSHORE SUNDAY
MORNING. HIGH TEMPERATURES ON SATURDAY WILL BE IN THE MID TO UPPER
60S AND LOW TO MID 70S ON SUNDAY. A WARM FRONT LIFTS NORTH ON MONDAY
BRINGING A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS. INSTABILITY
SLOWLY INCREASES THROUGH THIS TIME...SO MENTIONED CHANCE THUNDER ON
TUESDAY FROM NYC NORTH/WEST. THE WARM FRONT SHOULD LIFT TO THE NE BY
WEDNESDAY MORNING...BUT COULD BE FOLLOWED BY A WEAK COLD FRONT OR
PRE-FRONTAL WEDNESDAY AFTERNOON INTO THURSDAY MORNING...WITH CHANCE
OF AFTERNOON SHOWERS AND THUNDERSTORMS ONCE AGAIN WEDNESDAY AND
THURSDAY.
TEMPERATURES WILL SLOWLY WARM UP DURING THE WEEK. WITH TEMPERATURES
STARTING OUT IN THE LOW TO MID 70S ON MONDAY...THEN LOW TO MID 80S
BY MIDWEEK.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE BUILDS IN FROM THE WEST THROUGH TONIGHT. LOW
PRESSURE WILL PASS SOUTH OF THE REGION ON THURSDAY.
VFR THROUGH THE TAF PERIOD. LIGHT WINDS LESS THAN 10 KTS WILL
INCREASE THURSDAY WHILE BECOMING MORE SOUTHERLY. WIND SPEEDS
INCREASE TO 10-15 KT FOR THE AFTERNOON AND THEN LOWER AGAIN
THURSDAY NIGHT AS THEY BECOME MORE NORTHERLY.
SOME -RA WILL DEVELOP FOR MOST TERMINALS THURSDAY AFTERNOON AND
EVENING....BUT CATEGORIES WILL REMAIN VFR.
.OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
.LATE THU NIGHT...POSSIBLE MVFR IN RAIN. OTHERWISE VFR.
.FRI-FRI NIGHT...POSSIBLE MVFR EARLY. OTHERWISE VFR. NW GUSTS
15-20 KT...POSSIBLY UP TO 25 KT.
.SAT-SUN...VFR. S-SW WIND GUSTS BETWEEN 15-20 KT LATE SUN MORNING
AND SUN AFTERNOON.
.MON...CHANCE OF MVFR OR LOWER IN RAIN.
&&
.MARINE...
HIGH PRESSURE BRIEFLY BUILDS ACROSS THE WATERS TODAY. AS
SUCH...TRANQUIL WINDS AND SEAS ARE FORECAST. BY TONIGHT...THE HIGH
DEPARTS AND LOW PRESSURE APPROACHES AND TRACKS SOUTH AND EAST OF THE
WATERS. THIS LOW MOVES NORTHEAST AS A COLD FRONT APPROACHES FRIDAY
AFTERNOON. LIGHT NORTHERLY WINDS TONIGHT INTO FRIDAY MORNING TURN
TOWARD BACK TO THE WEST AND INCREASE DURING THE AFTERNOON. THERE
COULD VERY WELL BE 25 TO PERHAPS 30 KT GUSTS NEAR SHORE LATE IN
THE AFTERNOON...ESPECIALLY NY HARBOR AND WESTERN LI SOUND. WILL
HOLD OFF THOUGH ON ANY ADVISORIES ATTM DUE TO LATE 3RD
PERIOD...AND MAINLY A NEAR SHORE CONCERN.
TRANQUIL SEAS TONIGHT BUILDS LATE FRIDAY AFTERNOON IN RESPONSE TO
THE STRENGTHENING WESTERLY WINDS.
TRANQUIL CONDITIONS ARE EXPECTED SATURDAY AND SUNDAY MORNING...AS
HIGH PRESSURE BUILDS ACROSS THE AREA WATERS. SOUTHWEST FLOW
INCREASING TO 15-20 KT MAY BUILD OCEAN SEAS TO 5 FT SUNDAY
AFTERNOON/EVENING...ESPECIALLY FARTHER EAST WHERE A LONGER FETCH
WILL EXIST. OCEAN SEAS FALL BELOW SCA LEVELS BRIEFLY ON
MONDAY...THEN BUILD BACK TO SCA LEVELS ON TUESDAY.
&&
.FIRE WEATHER...
TODAY WILL REMAIN MAINLY CLOUDY AND COOL WITH LIGHT WINDS. SOME RAIN
IS EXPECTED LATE TODAY AND THROUGH TONIGHT...MAINLY ALONG THE COAST.
THEN...DRY WEATHER RETURNS FRIDAY. WEATHER CONDITIONS ON FRIDAY MAY
STILL BE CONDUCIVE TO GROWTH/SPREAD OF ANY FIRES THAT DEVELOP. MIN
RH ARE FORECAST TO BE IN THE 20S AND W-NW WINDS WILL GUST TO 25-30
MPH FRI AFTERNOON. KBDI IS IN THE 100S ACROSS MOST OF SRN CT AND THE
LOWER HUDSON VALLEY AND IN THE 200S ACROSS NYC METRO AND LONG
ISLAND...BUT MAY NOT BE FULLY REPRESENTATIVE OF THE PERSISTENT DRY
CONDITIONS THAT HAVE BEEN IN PLACE.
&&
.HYDROLOGY...
DRY THROUGH THIS MORNING. THEN THERE IS THE POTENTIAL
FOR AROUND A TENTH OF AN INCH OF RAIN ON AVERAGE NEAR THE COAST.
NORTHERN ZONES SUCH AS THE LOWER HUDSON VALLEY AND SRN CT...QPF
WOULD RANGE FROM A TRACE TO MAYBE A TENTH OF AN INCH.
THERE IS A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS MONDAY
INTO THE MIDDLE OF THE WEEK. MODEL UNCERTAINTIES ON
TIMING/PLACEMENT OF ANY HEAVY RAIN ARE STILL TOO LARGE TO MERIT
MENTION OF SPECIFIC AMOUNTS...AND MAY NOT EVEN PAN PER MODEL
FORECASTS OUT GIVEN THE PERSISTENT DRY PATTERN THAT HAS BEEN IN
PLACE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FIG/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...FIG
AVIATION...JM
MARINE...FIG/PW
FIRE WEATHER...
HYDROLOGY...FIG/PW
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
700 AM EDT THU MAY 21 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL TRACK SOUTH AND EAST OF OUR REGION LATE
TODAY AND TONIGHT, THEN A COLD FRONT CROSSES OUR AREA LATER FRIDAY.
HIGH PRESSURE BUILDS IN SATURDAY BUT THEN SHIFTS OFFSHORE SATURDAY
NIGHT AND SUNDAY. THE NEXT COLD FRONT DROPS INTO OUR AREA SUNDAY
NIGHT INTO MONDAY, THEN AS LOW PRESSURE TRACKS FROM THE PLAINS TO
THE GREAT LAKES REGION THE FRONT LIFTS BACK NORTH AS A WARM FRONT
LATE MONDAY INTO TUESDAY. A COLD FRONT IS FORECAST TO REMAIN WELL TO
OUR WEST DURING WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TODAY...HPC QPF AND 00Z/21 MODEL CONSENSUS HAS THE NORTHERN EDGE
OF THE MEASURABLE RAIN TODAY NEAR I-95. CALLED IT SHOWERS ON THE
NORTHERN EDGE OF THE RAIN SHIELD WHERE MORE SPORADIC. A PERIOD OF
MDT TO HEAVY RAIN APPEARS PROBABLE FAR SE NJ AND DELAWARE.
THIS 630AM FORECAST THEN TAKES INTO ACCOUNT THE HRRR AS WELL AS
THE NARRE THROUGH THIS MID AFTERNOON.
EXPANDED THE POTENTIAL FOR .01 NORTHWARD IN THIS ISSUANCE.
CONFIDENCE ON TEMPS/POPS IS BELOW AVERAGE FROM SE PA ACROSS
CENTRAL NJ WHERE GREATEST UNCERTAINTY EXISTS (KPHL- KTTN). TEMPS
WILL FALL INTO THE LOW AND MID 50S WHEN THE RAIN BECOMES STEADY. A
CHILLY DAY FOR THE DELMARVA. TEMPS WERE LOWERED SLIGHTLY IN THIS
UPDATE.
MEASURABLE RAIN IS NOT EXPECTED IN NE PA AND FAR NNJ TODAY (I80
NORTH).
LIGHT WIND WILL BE N-NE EARLY THIS MORNING THEN MIDDAY-THIS AFTN
BECOMES LIGHT SOUTH IN THE NORTH AND REMAINING E-NE ACROSS ACROSS
THE SOUTH.
WARMEST TEMPS MAY BE IN NNJ TODAY WHERE NO RAIN IS FCST.
FCST BASED ON A GENERAL 50 50 BLEND OF 00Z/21 NAM/GFS MOS.
CAUSE OF THE RAIN AND CLOUD COVER: INSTABILITY BURST WITH SLY FLOW
850 WAA BENEATH WSW FLOW AT MID LEVELS (700-500MB) WITH DECENT RRQ
250 JET AIDING LIFT. THIS AHEAD OF A RELATIVELY STRONG 500MB SHORT
WAVE MOVING ESEWD FROM THE MIDWEST THIS MORNING AND ARRIVING IN
THE UPPER OHIO VALLEY THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
LEFTOVER RAIN ALONG THE COAST AND A CHANCE OF A PERIOD OF RAIN OR
SHOWERS ELSEWHERE EARLY, THEN CLEARING TOWARD DAWN AS THE RELATIVELY
STRONG 500MB SHORT WAVE SEEN AS AN -80M 12 HR HFC PASSES THROUGH E
PA REACHING LI BY DAYBREAK FRIDAY.
PATCHY FOG POSSIBLE TOWARD DAWN IF IT CLEARS FAST ENOUGH AND IT
REMAINS DECOUPLED THROUGH THE NIGHT.
LIGHT WIND TREND W-NW OVERNIGHT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF A CLOSED LOW ACROSS EASTERN
CANADA THAT SHIFTS EASTWARD FRIDAY AND OVER THE WEEKEND AS ENERGY
STARTS TO EJECT INTO THE CENTRAL AND SOUTHERN PLAINS. THE LATTER
WILL TEND TO BUILD A RIDGE FROM NEAR FLORIDA NORTHWESTWARD TOWARD
THE MIDWEST SATURDAY INTO MONDAY. THE RIDGE THEN STRENGTHENS SOME AS
IT SHIFTS EASTWARD MONDAY AND TUESDAY, HOWEVER IT SHOULD FLATTEN
SOME ON ITS NORTHERN SIDE. THE MAIN FEATURE OF INTEREST IS A COLD
FRONT THAT DROPS DOWN LATE SUNDAY INTO MONDAY, BUT THEN IT LIFTS
BACK NORTH AS A WARM FRONT AS THE RIDGE BUILDS. IT LOOKS TO TURN
RATHER WARM TO EVEN HOT NEXT WEEK AS THE UPPER-LEVEL RIDGE IS IN
PLACE. WE USED A MODEL BLEND FOR FRIDAY THROUGH SUNDAY, THEN THE 00Z
WPC GUIDANCE WITH CONTINUITY THEREAFTER. SOME TWEAKS WERE THEN MADE
FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES.
FOR FRIDAY AND SATURDAY...THE CLOSED LOW TO OUR NORTH IS FORECAST TO
BE SHIFTING EASTWARD DURING THIS TIME FRAME AS ENERGY EJECTS INTO
THE CENTRAL AND SOUTHERN PLAINS. THIS WILL TAKE SURFACE LOW PRESSURE
INTO THE CANADIAN MARITIMES FRIDAY AND A COLD FRONT THROUGH OUR AREA
LATE IN THE DAY. WHILE THERE IS SOME INCREASE IN MOISTURE AHEAD OF
THE FRONT AND ALSO SOME LOWER LEVEL INSTABILITY FORECAST, THE DEEP
WESTERLY FLOW SHOULD TEND TO LIMIT THE CONVERGENCE. WHILE SOME
ISOLATED SHOWERS CANNOT BE RULED OUT, WE OPTED TO KEEP THE FORECAST
FRIDAY DRY ATTM. THE PRESSURE GRADIENT TIGHTENS WITH BREEZY
CONDITIONS DURING FRIDAY, THEN THIS GRADUALLY RELAXES LATER FRIDAY
NIGHT AND SATURDAY AS SURFACE HIGH PRESSURE MOVES IN. A MUCH DRIER
AIRMASS FOLLOWS THE FRONT, AND THIS WILL SET THE STAGE FOR A CHILLY
FRIDAY NIGHT AND EARLY SATURDAY. THERE COULD BE SOME FROST FORMATION
EARLY SATURDAY MORNING ACROSS PORTIONS OF THE NORTHERN ZONES,
PENDING WE DECOUPLE. FOR NOW, WE INCLUDED A PATCHY FROST MENTION.
HIGH PRESSURE THEN BEGINS TO SHIFT OFFSHORE SATURDAY NIGHT AS
RIDGING BUILDS TO OUR WEST.
FOR SUNDAY AND MONDAY...A RIDGE TO OUR WEST WILL GRADUALLY BUILD
EASTWARD. SOME ENERGY SLIDING SOUTHEASTWARD ACROSS NEW ENGLAND WILL
DROP A COLD FRONT INTO OUR AREA SUNDAY NIGHT AND MONDAY. THIS
FEATURE GENERALLY LOOKS TO BE ON THE WEAK SIDE, AND THERE IS SOME
GUIDANCE THAT HOLDS THIS FRONT FARTHER TO THE NORTH IN THE FORM OF A
WARM FRONT. THE FRONT DOES NOT LOOK TO STAY IN PLACE LONG AS THE
BUILDING RIDGE ALOFT ALONG WITH SURFACE HIGH PRESSURE TO OUR EAST
WILL HELP REINFORCE A SOUTHWESTERLY FLOW. THEREFORE THE BOUNDARY
SHOULD MOVE NORTH AS A WARM FRONT DURING MONDAY AND MONDAY NIGHT.
THERE MAY BE SOME CONVECTION RIDING ALONG OR NEAR THIS FRONT,
HOWEVER THIS MAY NOT BE UNTIL LATE MONDAY AS THE RIDGE AXIS MOVES
ACROSS. A WARMER AIRMASS SHOULD OVERSPREAD THE AREA ESPECIALLY
MONDAY AS AN EXPANDING WARM SECTOR MOVES NORTH, AND SOME INCREASE IN
THE DEW POINTS WILL ALSO OCCUR.
FOR TUESDAY AND WEDNESDAY...WE SHOULD BE IN THE WARM SECTOR DURING
THIS TIME FRAME AS A SHORT WAVE ALOFT AND SURFACE LOW TRACKS TO OUR
NORTH, WHICH WILL FLATTEN THE RIDGE SOME. WHILE THE SURFACE COLD
FRONT IS CURRENTLY FORECAST TO STAY TO OUR WEST, SOME CONVECTION
CANNOT BE RULED OUT AS THERE ARE SOME INDICATIONS OF A LEE SIDE
TROUGH DEVELOPING IN THE PRESENCE OF A WARM TO HOT AIRMASS ALONG
WITH AN INCREASE IN THE HUMIDITY. SOME PLACES HAVE A GOOD CHC OF
REACHING 90 DEGREES EACH AFTERNOON.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TODAY...VFR CIGS. LIGHT RAIN IS FORECAST TO SPREAD INTO OUR REGION
FROM THE WEST AND SOUTHWEST THIS MORNING. THE RAIN IS EXPECTED TO
REMAIN NEAR OR JUST SOUTH OF KABE. A PERIOD OF RAIN IS ANTICIPATED
FOR KILG, KPHL, KPNE AND KTTN DURING THE AFTN WITH THE CATEGORICAL
RAIN PROBABILITY RESTRICTED TO KILG. CONDITIONS SHOULD REMAIN IN
THE VFR CATEGORY AT THOSE LOCATIONS WITH CEILINGS STAYING ABOVE
3000 FEET AND VISIBILITY VALUES STAYING ABOVE 5 MILES.
THE RAIN IS FORECAST TO HAVE A GREATER IMPACT ON KMIV AND KACY
THAN ON OUR TAF SITES TO THE NORTH. CONDITIONS SHOULD DROP TO
MVFR AT KMIV AND KACY THIS AFTERNOON.
AFTER THIS MORNINGS LIGHT NE WIND TO START, A LIGHT SOUTHWEST
WIND MAY DEVELOP AT KRDG, KABE, KTTN, KPNE, KPHL AND KILG DURING
MIDDAY. THE WIND MAY REMAIN VARIABLE AT KMIV AND KACY OR IT COULD
RESETTLE INTO THE NORTHEAST OR EAST DURING THE AFTERNOON HOURS AT
THOSE LOCATIONS.
TONIGHT...MOSTLY VFR CIGS; ALTHOUGH, SOME LINGERING RAIN/SHWRS
MAY MEAN SOME SUB-VFR THROUGH THE FIRST PART OF THE NIGHT MAINLY
FROM AROUND KMIV/KACY AND SOUTH. LIGHT WIND TREND W-NW OVERNIGHT.
OUTLOOK...
FRIDAY...VFR OVERALL. A COLD FRONT MOVES THROUGH LATER IN THE DAY
WITH PERHAPS AN ISOLATED BRIEF SHOWER. WEST WINDS BECOMING NORTHWEST
AND GUSTING UP TO 25 KNOTS MAINLY DURING THE AFTERNOON AND EVENING,
THEN DIMINISHING.
SATURDAY...VFR. NORTHWEST WINDS AROUND 10 KNOTS.
SUNDAY...VFR. SOUTHWEST WINDS 10 TO 15 KNOTS, THEN TENDING TO BECOME
LIGHT AND VARIABLE AT NIGHT AS A FRONT DROPS NEAR OR INTO THE AREA.
MONDAY...MAINLY VFR. LIGHT AND VARIABLE WINDS BECOMING SOUTHWEST
AROUND 10 KNOTS. A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE
ESPECIALLY IN THE AFTERNOON.
&&
.MARINE...
SAFE BOATING WEEK CONTINUES THROUGH FRIDAY MORNING.
THERE IS A NEW USCG SAFETY APP THAT SHOULD BE OF VALUE TO
MARINERS AND WAS JUST UNVEILED THIS WEEK:
HTTP:/WWW.USCG.MIL/MOBILE
THIS APP PROVIDES ADDITIONAL SAFE BOATING RESOURCES FOR MOBILE DEVICE
USERS. WHEN LOCATION ENABLED, USERS CAN RECEIVE THE LATEST WEATHER
REPORTS FROM THE CLOSEST NOAA BUOY AS WELL AS REPORT THE LOCATION
OF A HAZARD ON THE WATER. IT FEATURES AN EMERGENCY ASSISTANCE
BUTTON, WHICH CAN CALL THE CLOSEST CG COMMAND CENTER.
THE FORECAST:
ISSUED SCA FOR THE DE BAY ATLC WATERS TONIGHT. NCAROLINA LOW
INTENSIFIES IN ITS DEPARTURE AND SHOULD DEVELOP MARGINAL 5 FT
HAZARDOUS SEAS AND A FEW SCA GUSTS AROUND 25 KT OVERNIGHT NEAR
44009.
OTHERWISE NO MARINE HEADLINE ANTICIPATED THROUGH TONIGHT.
NORTHERLY WINDS EARLY TODAY TEND NORTHEAST NORTHEAST-EAST BY
DAYBREAK THEN ONSHORE SOUTHEAST THIS AFTERNOON. WINDS EVENTUALLY BECOMING
NORTHWEST EVERYWHERE LATER THIS THURSDAY NIGHT.
OUTLOOK...
FRIDAY...A COLD FRONT MOVES THROUGH THE AREA LATE IN THE DAY AND THE
EVENING AS LOW PRESSURE MOVES AWAY, WITH A NORTHWEST WIND IN ITS
WAKE. PRIOR TO THIS, SOME GUSTS TO NEAR 25 KNOTS SHOULD LINGER
ACROSS THE FAR SOUTHERN COASTAL WATERS EARLY. THE FORECAST SOUNDINGS
SHOW BETTER MIXING MOSTLY NEARSHORE DURING THE DAY, THEN EXPANDING
TO OFFSHORE AT NIGHT AS COLDER AIR MOVES IN AND THEREFORE A SMALL
CRAFT ADVISORY MAY BE NEEDED FOR LATER FRIDAY NIGHT.
SATURDAY AND SUNDAY...NORTHWEST WIND GUSTS TO 25 KNOTS MAY OCCUR TO
START SATURDAY, OTHERWISE THE CONDITIONS SHOULD BE BELOW ADVISORY
CRITERIA.
MONDAY...A SOUTHWESTERLY FLOW IS ANTICIPATED TO INCREASE SOME,
HOWEVER THE CONDITIONS OVERALL SHOULD BE BELOW ADVISORY CRITERIA.
SOME SHOWERS AND THUNDERSTORMS ARE POSSIBLE.
&&
.FIRE WEATHER...
FOR FRIDAY AFTERNOON, THERE MAY BE THE RISK FOR ENHANCED WILDFIRE
SPREAD AS WEST-NORTHWEST WINDS GUST TO 20-25 MPH AT TIMES. IN
ADDITION, THIS WILL COMBINE WITH RELATIVE HUMIDITY VALUES DROPPING
TO AROUND 30 PERCENT IN SOME AREAS ALONG WITH DRY FINE FUELS. THIS
WILL DEPEND ON HOW MUCH WETTING OCCURS LATER TODAY ESPECIALLY ACROSS
THE SOUTHERN AREAS.
&&
.RIP CURRENTS...
SST`S ABOVE NORMAL AND JUST OFF THE COAST SSTS WELL ABOVE NORMAL
BY ALMOST 3C. THIS IS NOT GOOD ONCE IT TURNS HOT AND BEACHES ARE
UNGUARDED, SWIMMERS MAY TAKE CHANCES AT UNGUARDED LOCATIONS. BE
SMART ABOUT ANY SWIMMING EARLY THIS SEASON. ATLANTIC COASTAL WATER
TEMPS ARE WARMING --UPPER 50S TO MID 60S.
RIP CURRENT AWARENESS WEEK FOR MT HOLLY IS JUNE 7-13 WITH PSAS
VIA PUBLIC INFORMATION STATEMENTS, SOCIAL MEDIA, NOAA WEATHER
RADIO AND ANY MEDIA INTERVIEWS DESIRED (CONTACT OFFICE).
FOR RIP CURRENTS: DESPITE ANTICIPATED PROJECTIONS OF LOW OR
MODERATE RISK THROUGH THE MEMORIAL DAY WEEKEND, EARLY SEASON
FATALITIES OCCUR WHEN SWIMMING AT UNGUARDED TIMES/LOCATIONS.
WEAKER SWIMMERS OR SWIMMING IN AREAS WHERE RIP CURRENTS ARE
STRONGER (JETTIES) CAN QUICKLY BECOME LIFE THREATENING. WHEN
TRAINED LIFEGUARDS ARE NOT NEARBY, TIMELY RESCUE IS MUCH LESS
LIKELY. LETS GET THROUGH THE MONTH OF MAY WITH ALL SWIMMERS SAFE!
SWIM IN THE PRESENCE OF LIFE GUARDS! THANK YOU.
&&
.CLIMATE...
**TOP 10 WARMEST MAY CONTINUES LIKELY IN PORTIONS OF THE FORECAST
AREA**
THE FIRST 19 DAYS OF MAY IN OUR FORECAST AREA WERE AVERAGING WITHIN
ABOUT 1/2 DEGREE OF 7 DEGREES ABOVE NORMAL.
BASED ON THE ENSEMBLE AND A FORECAST THAT IS DETERMINISTICALLY
CONSERVATIVE INCLUDING OUR 330 PM MAY 20 PROJECTIONS THROUGH THE
27TH AND THEN THE 00Z/21 CONSERVATIVE FTPRHA THEREAFTER THROUGH
THE 31ST...EASILY OUTLOOKS A TOP 10 WARMEST MAY ON RECORD.
FOR PHILADELPHIA...PERIOD OF RECORD BACK TO 1874. PROJECTING AN
AVG TEMP OF 68.7 TO 69.3 OR AROUND 5 DEGREES ABOVE NORMAL AND AT
THE LEAST, 3RD WARMEST ON RECORD. WARMEST WAS 70.8 IN 1991. THEN
69.2 2004.
FOR ALLENTOWN...POR TO 1922. YESTERDAY WE WERE PROJECTING 65.0 OR
5.1 DEGREES ABOVE NORMAL AND 8TH WARMEST ON RECORD. WARMEST WAS
67.2 IN 1991.
POSTED BECAUSE WE`RE EXPECTING OUR FIRST 90 IN PHILADELPHIA BY THE
MIDDLE OF NEXT WEEK.
NORMAL FIRST DATE OF 90 OR HIGHER.
PHILADELPHIA MAY 29
ALLENTOWN MAY 30
WILMINGTON JUNE 4
ATLANTIC CITY JUNE 11.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 8 AM EDT
FRIDAY FOR ANZ455.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...DRAG 7A
SHORT TERM...DRAG
LONG TERM...GORSE
AVIATION...DRAG/GORSE 7A
MARINE...DRAG/GORSE
FIRE WEATHER...
RIP CURRENTS...
CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
337 AM EDT THU MAY 21 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL TRACK SOUTH AND EAST OF OUR REGION LATE
TODAY AND TONIGHT, THEN A COLD FRONT CROSSES OUR AREA LATER FRIDAY.
HIGH PRESSURE BUILDS IN SATURDAY BUT THEN SHIFTS OFFSHORE SATURDAY
NIGHT AND SUNDAY. THE NEXT COLD FRONT DROPS INTO OUR AREA SUNDAY
NIGHT INTO MONDAY, THEN AS LOW PRESSURE TRACKS FROM THE PLAINS TO
THE GREAT LAKES REGION THE FRONT LIFTS BACK NORTH AS A WARM FRONT
LATE MONDAY INTO TUESDAY. A COLD FRONT IS FORECAST TO REMAIN WELL TO
OUR WEST DURING WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TODAY...HPC QPF AND 00Z/21 MODEL CONSENSUS HAS THE NORTHERN EDGE
OF THE MEASURABLE RAIN TODAY NEAR I-95. THIS 330AM FORECAST THEN
TAKES INTO ACCOUNT THE HRRR AS WELL AS THE NARRE THROUGH THIS
MORNING. CONFIDENCE ON TEMPS/POPS IS BELOW AVERAGE FROM SE PA
ACROSS CENTRAL NJ WHERE GREATEST UNCERTAINTY EXISTS (KPHL-KTTN).
NO RAIN IS EXPECTED IN NE PA AND NNJ TODAY.
LIGHT WIND WILL BE N-NE THIS MORNING THEN THIS AFTN BECOMES LIGHT
SOUTH IN THE NORTH AND REMAINING E-NE ACROSS ACROSS THE SOUTH.
WARMEST TEMPS MAY BE IN NNJ TODAY WHERE NO RAIN IS FCST.
FCST BASED ON A GENERAL 50 50 BLEND OF 00Z/21 NAM/GFS MOS.
CAUSE OF THE RAIN AND CLOUD COVER: INSTABILITY BURST WITH SLY FLOW
WAA AHEAD OF A RELATIVELY STRONG 500MB SHORT WAVE MOVING ESEWD
FROM THE MIDWEST THIS MORNING AND ARRIVING IN THE UPPER OHIO
VALLEY THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
LEFTOVER RAIN ALONG THE COAST AND A CHANCE OF A PERIOD OF RAIN
ELSEWHERE EARLY, THEN CLEARING TOWARD DAWN AS THE RELATIVELY STRONG
500MB SHORT WAVE SEEN AS AN -80M 12 HR HFC PASSES THROUGH E PA
REACHING LI BY DAYBREAK FRIDAY.
PATCHY FOG POSSIBLE TOWARD DAWN IF IT CLEARS FAST ENOUGH AND IT
REMAINS DECOUPLED THROUGH THE NIGHT.
LIGHT WIND TREND W-NW OVERNIGHT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF A CLOSED LOW ACROSS EASTERN
CANADA THAT SHIFTS EASTWARD FRIDAY AND OVER THE WEEKEND AS ENERGY
STARTS TO EJECT INTO THE CENTRAL AND SOUTHERN PLAINS. THE LATTER
WILL TEND TO BUILD A RIDGE FROM NEAR FLORIDA NORTHWESTWARD TOWARD
THE MIDWEST SATURDAY INTO MONDAY. THE RIDGE THEN STRENGTHENS SOME AS
IT SHIFTS EASTWARD MONDAY AND TUESDAY, HOWEVER IT SHOULD FLATTEN
SOME ON ITS NORTHERN SIDE. THE MAIN FEATURE OF INTEREST IS A COLD
FRONT THAT DROPS DOWN LATE SUNDAY INTO MONDAY, BUT THEN IT LIFTS
BACK NORTH AS A WARM FRONT AS THE RIDGE BUILDS. IT LOOKS TO TURN
RATHER WARM TO EVEN HOT NEXT WEEK AS THE UPPER-LEVEL RIDGE IS IN
PLACE. WE USED A MODEL BLEND FOR FRIDAY THROUGH SUNDAY, THEN THE 00Z
WPC GUIDANCE WITH CONTINUITY THEREAFTER. SOME TWEAKS WERE THEN MADE
FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES.
FOR FRIDAY AND SATURDAY...THE CLOSED LOW TO OUR NORTH IS FORECAST TO
BE SHIFTING EASTWARD DURING THIS TIME FRAME AS ENERGY EJECTS INTO
THE CENTRAL AND SOUTHERN PLAINS. THIS WILL TAKE SURFACE LOW PRESSURE
INTO THE CANADIAN MARITIMES FRIDAY AND A COLD FRONT THROUGH OUR AREA
LATE IN THE DAY. WHILE THERE IS SOME INCREASE IN MOISTURE AHEAD OF
THE FRONT AND ALSO SOME LOWER LEVEL INSTABILITY FORECAST, THE DEEP
WESTERLY FLOW SHOULD TEND TO LIMIT THE CONVERGENCE. WHILE SOME
ISOLATED SHOWERS CANNOT BE RULED OUT, WE OPTED TO KEEP THE FORECAST
FRIDAY DRY ATTM. THE PRESSURE GRADIENT TIGHTENS WITH BREEZY
CONDITIONS DURING FRIDAY, THEN THIS GRADUALLY RELAXES LATER FRIDAY
NIGHT AND SATURDAY AS SURFACE HIGH PRESSURE MOVES IN. A MUCH DRIER
AIRMASS FOLLOWS THE FRONT, AND THIS WILL SET THE STAGE FOR A CHILLY
FRIDAY NIGHT AND EARLY SATURDAY. THERE COULD BE SOME FROST FORMATION
EARLY SATURDAY MORNING ACROSS PORTIONS OF THE NORTHERN ZONES,
PENDING WE DECOUPLE. FOR NOW, WE INCLUDED A PATCHY FROST MENTION.
HIGH PRESSURE THEN BEGINS TO SHIFT OFFSHORE SATURDAY NIGHT AS
RIDGING BUILDS TO OUR WEST.
FOR SUNDAY AND MONDAY...A RIDGE TO OUR WEST WILL GRADUALLY BUILD
EASTWARD. SOME ENERGY SLIDING SOUTHEASTWARD ACROSS NEW ENGLAND WILL
DROP A COLD FRONT INTO OUR AREA SUNDAY NIGHT AND MONDAY. THIS
FEATURE GENERALLY LOOKS TO BE ON THE WEAK SIDE, AND THERE IS SOME
GUIDANCE THAT HOLDS THIS FRONT FARTHER TO THE NORTH IN THE FORM OF A
WARM FRONT. THE FRONT DOES NOT LOOK TO STAY IN PLACE LONG AS THE
BUILDING RIDGE ALOFT ALONG WITH SURFACE HIGH PRESSURE TO OUR EAST
WILL HELP REINFORCE A SOUTHWESTERLY FLOW. THEREFORE THE BOUNDARY
SHOULD MOVE NORTH AS A WARM FRONT DURING MONDAY AND MONDAY NIGHT.
THERE MAY BE SOME CONVECTION RIDING ALONG OR NEAR THIS FRONT,
HOWEVER THIS MAY NOT BE UNTIL LATE MONDAY AS THE RIDGE AXIS MOVES
ACROSS. A WARMER AIRMASS SHOULD OVERSPREAD THE AREA ESPECIALLY
MONDAY AS AN EXPANDING WARM SECTOR MOVES NORTH, AND SOME INCREASE IN
THE DEW POINTS WILL ALSO OCCUR.
FOR TUESDAY AND WEDNESDAY...WE SHOULD BE IN THE WARM SECTOR DURING
THIS TIME FRAME AS A SHORT WAVE ALOFT AND SURFACE LOW TRACKS TO OUR
NORTH, WHICH WILL FLATTEN THE RIDGE SOME. WHILE THE SURFACE COLD
FRONT IS CURRENTLY FORECAST TO STAY TO OUR WEST, SOME CONVECTION
CANNOT BE RULED OUT AS THERE ARE SOME INDICATIONS OF A LEE SIDE
TROUGH DEVELOPING IN THE PRESENCE OF A WARM TO HOT AIRMASS ALONG
WITH AN INCREASE IN THE HUMIDITY. SOME PLACES HAVE A GOOD CHC OF
REACHING 90 DEGREES EACH AFTERNOON.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...VFR. AREAS OF CIGS AOA 20000 FT LOWER TO NEAR 10000
FT AT 12Z. WIND NNW BECOMING NNE WITH GUSTS 10-15 KT FROM THE I-95
CORRIDOR EASTWARD INCLUDING KPHL GROUP OF TAFS.
AFTER 12Z TODAY...VFR CIGS. LIGHT RAIN IS FORECAST TO SPREAD INTO
OUR REGION FROM THE WEST AND SOUTHWEST AROUND 1500Z. THE RAIN IS
EXPECTED TO REMAIN SOUTH OF KRDG AND KABE. A PERIOD OF LIGHT RAIN
IS ANTICIPATED FOR KILG, KPHL, KPNE AND KTTN DURING THE AFTN WITH
THE CATEGORICAL RAIN PROBABILITY RESTRICTED TO KILG. CONDITIONS
SHOULD REMAIN IN THE VFR CATEGORY AT THOSE LOCATIONS WITH CEILINGS
STAYING ABOVE 3000 FEET AND VISIBILITY VALUES STAYING ABOVE 5
MILES.
THE RAIN IS FORECAST TO HAVE A GREATER IMPACT ON KMIV AND KACY
THAN ON OUR TAF SITES TO THE NORTH. CONDITIONS MAY DROP TO MVFR AT
KMIV AND KACY THIS THURSDAY AFTERNOON.
AFTER THIS MORNINGS LIGHT NE WIND TO START, A LIGHT SOUTHWEST
WIND MAY DEVELOP AT KRDG, KABE, KTTN, KPNE, KPHL AND KILG DURING
MIDDAY. THE WIND MAY REMAIN VARIABLE AT KMIV AND KACY OR IT COULD
RESETTLE INTO THE NORTHEAST OR EAST DURING THE AFTERNOON HOURS AT
THOSE LOCATIONS.
TONIGHT...MOSTLY VFR CIGS; ALTHOUGH, SOME LINGERING RAIN/SHWRS
MAY MEAN SOME SUB-VFR THROUGH THE FIRST PART OF THE NIGHT MAINLY
FROM AROUND KMIV/KACY AND SOUTH. LIGHT WIND TREND W-NW OVERNIGHT.
OUTLOOK...
FRIDAY...VFR OVERALL. A COLD FRONT MOVES THROUGH LATER IN THE DAY
WITH PERHAPS AN ISOLATED BRIEF SHOWER. WEST WINDS BECOMING NORTHWEST
AND GUSTING UP TO 25 KNOTS MAINLY DURING THE AFTERNOON AND EVENING,
THEN DIMINISHING.
SATURDAY...VFR. NORTHWEST WINDS AROUND 10 KNOTS.
SUNDAY...VFR. SOUTHWEST WINDS 10 TO 15 KNOTS, THEN TENDING TO BECOME
LIGHT AND VARIABLE AT NIGHT AS A FRONT DROPS NEAR OR INTO THE AREA.
MONDAY...MAINLY VFR. LIGHT AND VARIABLE WINDS BECOMING SOUTHWEST
AROUND 10 KNOTS. A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE
ESPECIALLY IN THE AFTERNOON.
&&
.MARINE...
SAFE BOATING WEEK CONTINUES THROUGH FRIDAY MORNING.
THERE IS A NEW USCG SAFETY APP THAT SHOULD BE OF VALUE TO
MARINERS AND WAS JUST UNVEILED THIS WEEK:
HTTP:/WWW.USCG.MIL/MOBILE
THIS APP PROVIDES ADDITIONAL SAFE BOATING RESOURCES FOR MOBILE DEVICE
USERS. WHEN LOCATION ENABLED, USERS CAN RECEIVE THE LATEST WEATHER
REPORTS FROM THE CLOSEST NOAA BUOY AS WELL AS REPORT THE LOCATION
OF A HAZARD ON THE WATER. IT FEATURES AN EMERGENCY ASSISTANCE
BUTTON, WHICH CAN CALL THE CLOSEST CG COMMAND CENTER.
THE FORECAST:
ISSUING SCA FOR THE DE BAY ATLC WATERS TONIGHT. NCAROLINA LOW
INTENSIFIES IN ITS DEPARTURE AND SHOULD DEVELOP MARGINAL 5 FT
HAZARDOUS SEAS AND A FEW SCA GUSTS AROUND 25 KT OVERNIGHT NEAR
44009.
OTHERWISE NO MARINE HEADLINE ANTICIPATED THROUGH TONIGHT.
NORTHERLY WINDS EARLY TODAY TEND NORTHEAST NORTHEAST-EAST BY
DAYBREAK THEN ONSHORE SOUTHEAST THIS AFTERNOON. WINDS EVENTUALLY BECOMING
NORTHWEST EVERYWHERE LATER THIS THURSDAY NIGHT.
OUTLOOK...
FRIDAY...A COLD FRONT MOVES THROUGH THE AREA LATE IN THE DAY AND THE
EVENING AS LOW PRESSURE MOVES AWAY, WITH A NORTHWEST WIND IN ITS
WAKE. PRIOR TO THIS, SOME GUSTS TO NEAR 25 KNOTS SHOULD LINGER
ACROSS THE FAR SOUTHERN COASTAL WATERS EARLY. THE FORECAST SOUNDINGS
SHOW BETTER MIXING MOSTLY NEARSHORE DURING THE DAY, THEN EXPANDING
TO OFFSHORE AT NIGHT AS COLDER AIR MOVES IN AND THEREFORE A SMALL
CRAFT ADVISORY MAY BE NEEDED FOR LATER FRIDAY NIGHT.
SATURDAY AND SUNDAY...NORTHWEST WIND GUSTS TO 25 KNOTS MAY OCCUR TO
START SATURDAY, OTHERWISE THE CONDITIONS SHOULD BE BELOW ADVISORY
CRITERIA.
MONDAY...A SOUTHWESTERLY FLOW IS ANTICIPATED TO INCREASE SOME,
HOWEVER THE CONDITIONS OVERALL SHOULD BE BELOW ADVISORY CRITERIA.
SOME SHOWERS AND THUNDERSTORMS ARE POSSIBLE.
&&
.FIRE WEATHER...
FOR FRIDAY AFTERNOON, THERE MAY BE THE RISK FOR ENHANCED WILDFIRE
SPREAD AS WEST-NORTHWEST WINDS GUST TO 20-25 MPH AT TIMES. IN
ADDITION, THIS WILL COMBINE WITH RELATIVE HUMIDITY VALUES DROPPING
TO AROUND 30 PERCENT IN SOME AREAS ALONG WITH DRY FINE FUELS. THIS
WILL DEPEND ON HOW MUCH WETTING OCCURS LATER TODAY ESPECIALLY ACROSS
THE SOUTHERN AREAS.
&&
.RIP CURRENTS...
SST`S ABOVE NORMAL AND JUST OFF THE COAST SSTS WELL ABOVE NORMAL
BY ALMOST 3C. THIS IS NOT GOOD ONCE IT TURNS HOT AND BEACHES ARE
UNGUARDED, SWIMMERS MAY TAKE CHANCES AT UNGUARDED LOCATIONS. BE
SMART ABOUT ANY SWIMMING EARLY THIS SEASON. ATLANTIC COASTAL WATER
TEMPS ARE WARMING --UPPER 50S TO MID 60S.
RIP CURRENT AWARENESS WEEK FOR MT HOLLY IS JUNE 7-13 WITH PSAS
VIA PUBLIC INFORMATION STATEMENTS, SOCIAL MEDIA, NOAA WEATHER
RADIO AND ANY MEDIA INTERVIEWS DESIRED (CONTACT OFFICE).
FOR RIP CURRENTS: DESPITE ANTICIPATED PROJECTIONS OF LOW OR
MODERATE RISK THROUGH THE MEMORIAL DAY WEEKEND, EARLY SEASON
FATALITIES OCCUR WHEN SWIMMING AT UNGUARDED TIMES/LOCATIONS.
WEAKER SWIMMERS OR SWIMMING IN AREAS WHERE RIP CURRENTS ARE
STRONGER (JETTIES) CAN QUICKLY BECOME LIFE THREATENING. WHEN
TRAINED LIFEGUARDS ARE NOT NEARBY, TIMELY RESCUE IS MUCH LESS
LIKELY. LETS GET THROUGH THE MONTH OF MAY WITH ALL SWIMMERS SAFE!
SWIM IN THE PRESENCE OF LIFE GUARDS! THANK YOU.
&&
.CLIMATE...
**TOP 10 WARMEST MAY CONTINUES LIKELY IN PORTIONS OF THE FORECAST
AREA**
THE FIRST 19 DAYS OF MAY IN OUR FORECAST AREA WERE AVERAGING WITHIN
ABOUT 1/2 DEGREE OF 7 DEGREES ABOVE NORMAL.
BASED ON THE ENSEMBLE AND A FORECAST THAT IS DETERMINISTICALLY
CONSERVATIVE INCLUDING OUR 330 PM MAY 20 PROJECTIONS THROUGH THE
27TH AND THEN THE 00Z/21 CONSERVATIVE FTPRHA THEREAFTER THROUGH
THE 31ST...EASILY OUTLOOKS A TOP 10 WARMEST MAY ON RECORD.
FOR PHILADELPHIA...PERIOD OF RECORD BACK TO 1874. PROJECTING AN
AVG TEMP OF 68.7 TO 69.3 OR AROUND 5 DEGREES ABOVE NORMAL AND AT
THE LEAST, 3RD WARMEST ON RECORD. WARMEST WAS 70.8 IN 1991. THEN
69.2 2004.
FOR ALLENTOWN...POR TO 1922. YESTERDAY WE WERE PROJECTING 65.0 OR
5.1 DEGREES ABOVE NORMAL AND 8TH WARMEST ON RECORD. WARMEST WAS
67.2 IN 1991.
POSTED BECAUSE WE`RE EXPECTING OUR FIRST 90 IN PHILADELPHIA BY THE
MIDDLE OF NEXT WEEK.
NORMAL FIRST DATE OF 90 OR HIGHER.
PHILADELPHIA MAY 29
ALLENTOWN MAY 30
WILMINGTON JUNE 4
ATLANTIC CITY JUNE 11.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 8 AM EDT
FRIDAY FOR ANZ455.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...DRAG
SHORT TERM...DRAG
LONG TERM...GORSE
AVIATION...DRAG/GORSE
MARINE...DRAG/GORSE
FIRE WEATHER...GORSE
RIP CURRENTS...DRAG
CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
238 AM EDT THU MAY 21 2015
.SYNOPSIS...
WEAK HIGH PRESSURE PREVAILS OVER THE MID ATLANTIC STATES EARLY TODAY.
LOW PRESSURE INN THE CAROLINAS WILL STRENGTHEN AS IT MOVES NORTHEASTWARD
OUT TO SEA THIS EVENING. A WEAK COLD FRONT WILL CROSS THE AREA FRIDAY,
FOLLOWED BY HIGH PRESSURE RETURNING ACROSS THE REGION FRIDAY NIGHT
THROUGH SATURDAY, BEFORE PROGRESSING OFFSHORE SUNDAY. ORGANIZING
LOW PRESSURE ACROSS THE CENTRAL UNITED STATES WILL ALLOW A WARM
FRONT TO LIFT NORTH THROUGH THE REGION MONDAY, AND A COLD FRONT IS
FORECAST TO APPROACH FROM THE WEST TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
TODAY...HPC QPF AND 00Z/21 MODEL CONSENSUS HAS THE NORTHERN EDGE
OF THE MEASURABLE RAIN TODAY NEAR I-95. THIS 330AM FORECAST THEN
TAKES INTO ACCOUNT THE HRRR AS WELL AS THE NARRE THROUGH THIS
MORNING. CONFIDENCE ON TEMPS/POPS IS BELOW AVERAGE FROM SE PA
ACROSS CENTRAL NJ WHERE GREATEST UNCERTAINTY EXISTS (KPHL-KTTN).
NO RAIN IS EXPECTED IN NE PA AND NNJ TODAY.
LIGHT WIND WILL BE N-NE THIS MORNING THEN THIS AFTN BECOMES LIGHT
SOUTH IN THE NORTH AND REMAINING E-NE ACROSS ACROSS THE SOUTH.
WARMEST TEMPS MAY BE IN NNJ TODAY WHERE NO RAIN IS FCST.
FCST BASED ON A GENERAL 50 50 BLEND OF 00Z/21 NAM/GFS MOS.
CAUSE OF THE RAIN AND CLOUD COVER: INSTABILITY BURST WITH SLY FLOW
WAA AHEAD OF A RELATIVELY STRONG 500MB SHORT WAVE MOVING ESEWD
FROM THE MIDWEST THIS MORNING AND ARRIVING IN THE UPPER OHIO
VALLEY THIS EVENING.
&&
.SHORT TERM /TONIGHT/...
LEFTOVER RAIN ALONG THE COAST AND A CHANCE OF A PERIOD OF RAIN
ELSEWHERE EARLY, THEN CLEARING TOWARD DAWN AS THE RELATIVELY STRONG
500MB SHORT WAVE SEEN AS AN -80M 12 HR HFC PASSES THROUGH E PA
REACHING LI BY DAYBREAK FRIDAY.
PATCHY FOG POSSIBLE TOWARD DAWN IF IT CLEARS FAST ENOUGH AND IT
REMAINS DECOUPLED THROUGH THE NIGHT.
LIGHT WIND TREND W-NW OVERNIGHT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
ANOTHER WEAK SURFACE LOW PRESSURE WILL BE TRACKING TOWARD NORTHERN
NEW ENGLAND AND THE CANADIAN MARITIMES THROUGH THE DAYTIME FRIDAY,
WITH ITS ASSOCIATED COLD FRONT EXPECTED TO CROSS OUT REGION FRIDAY
AFTERNOON TO EVENING. WITH VERY LIMITED MOISTURE, WE HAVE
MAINTAINED A DRY FORECAST FRIDAY; ALTHOUGH, WEST- NORTHWEST WINDS
WILL PICK UP IN THE WAKE OF THIS FRONT AS THE PRESSURE GRADIENT
TIGHTENS FOR A TIME. WINDS THEN RELAX LATER FRIDAY NIGHT AND
THROUGH SATURDAY AS AN AREA OF HIGH PRESSURE BUILDS EASTWARD FROM
THE MIDWEST STATES. A COOL FRIDAY NIGHT WITH BELOW AVERAGE
TEMPERATURES IS ANTICIPATED FOR OUR AREA, WITH CLEARING SKIES AND
LIGHT WINDS. OVERNIGHT LOWS WILL RANGE FROM THE LOWER 50S IN THE
SOUTHERN DELMARVA TO THE LOWER 40S ACROSS OUR NORTHERN ZONES AND
PERHAPS EVEN SOME 30S AND PATCHY FROST INTO THE HIGHER TERRAIN OF
THE POCONOS.
LIGHT WINDS, AMPLE SUN, AND NEAR AVERAGE MAY TEMPERATURES ARE
EXPECTED FOR OUR AREA WITH HIGH PRESSURE PASSING OVER THE REGION
SATURDAY. WHILE SUNDAY WILL STILL BE PLEASANT, TEMPERATURES AND
DEWPOINTS WILL BE CREEPING UPWARD A FEW DEGREES AS THE AREA OF HIGH
PRESSURE EASES OFFSHORE AND A RETURN SOUTHWESTERLY FLOW SETS UP OVER
THE REGION. THIS WARMING TREND AND GRADUAL INCREASE IN DEWPOINTS
WILL CONTINUE THEN INTO MONDAY AS AN AREA OF LOW PRESSURE IS
FORECAST TO ORGANIZE OVER THE CENTRAL UNITED STATES, WITH ITS
ASSOCIATED WARM FRONT LIFTING NORTH THROUGH THE OHIO VALLEY AND OUR
REGION MONDAY. THERE SHOULD BE ENOUGH LIFT AND INSTABILITY AS THIS
BOUNDARY PASSES NORTH FOR SOME SCATTERED SHWR/TSTORM ACTIVITY ACROSS
OUR REGION, AND WE HAVE KEPT CHANCE POPS IN PLACE FOR MEMORIAL DAY,
SOMEWHAT HIGHER CHANCES FOR THE NORTHERN TWO-THIRDS OF THE FORECAST
AREA.
A MORE NOTICEABLE INCREASE IN WARMTH AND HUMIDITY IS THEN EXPECTED
GOING INTO TUESDAY AS OUR REGION WILL BE IN THE WARM SECTOR, WITH
THE SURFACE LOW AND WARM FRONT TO OUR NORTH. BUILDING INSTABILITY
AND A COLD FRONT APPROACHING FROM THE WEST WILL YIELD MORE SCATTERED
SHWR/TSTORM POTENTIAL, AND WE KEPT SOME CHANCE POPS IN PLACE THROUGH
THIS TIMEFRAME. DAYTIME TEMPERATURES SHOULD EASILY REACH INTO THE
MIDDLE AND UPPER 80S FROM THE DELAWARE VALLEY INTO THE DELMARVA,
WITH SOMEWHAT COOLER UPPER 70S/LOW 80S FARTHER NORTH AND ALONG THE
COAST. A LITTLE MORE UNCERTAINTY EXISTS INTO WEDNESDAY WITH REGARDS
TO ISOLATED/SCATTERED PRECIP POTENTIAL DEPENDING ON THE PROGRESS OF
THE FRONTAL BOUNDARY, AND FOR NOW, WE INTRODUCED SOME VERY LOW POPS
INTO THE FORECAST FOR THE WEDNESDAY TIMEFRAME.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...VFR. AREAS OF CIGS AOA 20000 FT LOWER TO NEAR 10000
FT AT 12Z. WIND NNW BECOMING NNE WITH GUSTS 10-15 KT FROM THE I-95
CORRIDOR EASTWARD INCLUDING KPHL GROUP OF TAFS.
AFTER 12Z TODAY...VFR CIGS. LIGHT RAIN IS FORECAST TO SPREAD INTO
OUR REGION FROM THE WEST AND SOUTHWEST AROUND 1500Z. THE RAIN IS
EXPECTED TO REMAIN SOUTH OF KRDG AND KABE. A PERIOD OF LIGHT RAIN
IS ANTICIPATED FOR KILG, KPHL, KPNE AND KTTN DURING THE AFTN WITH
THE CATEGORICAL RAIN PROBABILITY RESTRICTED TO KILG. CONDITIONS
SHOULD REMAIN IN THE VFR CATEGORY AT THOSE LOCATIONS WITH CEILINGS
STAYING ABOVE 3000 FEET AND VISIBILITY VALUES STAYING ABOVE 5
MILES.
THE RAIN IS FORECAST TO HAVE A GREATER IMPACT ON KMIV AND KACY
THAN ON OUR TAF SITES TO THE NORTH. CONDITIONS MAY DROP TO MVFR AT
KMIV AND KACY THIS THURSDAY AFTERNOON.
AFTER THIS MORNINGS LIGHT NE WIND TO START, A LIGHT SOUTHWEST
WIND MAY DEVELOP AT KRDG, KABE, KTTN, KPNE, KPHL AND KILG DURING
MIDDAY. THE WIND MAY REMAIN VARIABLE AT KMIV AND KACY OR IT COULD
RESETTLE INTO THE NORTHEAST OR EAST DURING THE AFTERNOON HOURS AT
THOSE LOCATIONS.
TONIGHT...MOSTLY VFR CIGS; ALTHOUGH, SOME LINGERING RAIN/SHWRS
MAY MEAN SOME SUB-VFR THROUGH THE FIRST PART OF THE NIGHT MAINLY
FROM AROUND KMIV/KACY AND SOUTH. LIGHT WIND TREND W-NW OVERNIGHT.
OUTLOOK...
FRIDAY...VFR CONDITIONS ARE EXPECTED WITH WEST-NORTHWEST WINDS
GUSTING TO AROUND 20 KNOTS DURING THE AFTERNOON.
SATURDAY...CONTINUED VFR WITH LIGHT NORTHWEST WINDS.
SUNDAY...VFR CONDITIONS WITH SOUTHWEST WINDS 10 TO 15 KNOTS.
MONDAY...MAINLY VFR WITH LIGHT SOUTHWEST WINDS; ALTHOUGH, SOME
SCATTERED SHWRS/TSTORMS AND SUB-VFR POSSIBLE AT TIMES.
&&
.MARINE...
SAFE BOATING WEEK CONTINUES THROUGH FRIDAY MORNING.
THERE IS A NEW USCG SAFETY APP THAT SHOULD BE OF VALUE TO
MARINERS AND WAS JUST UNVEILED THIS WEEK:
HTTP:/WWW.USCG.MIL/MOBILE
THIS APP PROVIDES ADDITIONAL SAFE BOATING RESOURCES FOR MOBILE DEVICE
USERS. WHEN LOCATION ENABLED, USERS CAN RECEIVE THE LATEST WEATHER
REPORTS FROM THE CLOSEST NOAA BUOY AS WELL AS REPORT THE LOCATION
OF A HAZARD ON THE WATER. IT FEATURES AN EMERGENCY ASSISTANCE
BUTTON, WHICH CAN CALL THE CLOSEST CG COMMAND CENTER.
THE FORECAST:
ISSUING SCA FOR THE DE BAY ATLC WATERS TONIGHT. NCAROLINA LOW
INTENSIFIES IN ITS DEPARTURE AND SHOULD DEVELOP MARGINAL 5 FT
HAZARDOUS SEAS AND A FEW SCA GUSTS AROUND 25 KT OVERNIGHT NEAR
44009.
OTHERWISE NO MARINE HEADLINE ANTICIPATED THROUGH TONIGHT.
NORTHERLY WINDS EARLY TODAY TEND NORTHEAST NORTHEAST-EAST BY
DAYBREAK THEN ONSHORE SOUTHEAST THIS AFTERNOON. WINDS EVENTUALLY BECOMING
NORTHWEST EVERYWHERE LATER THIS THURSDAY NIGHT.
OUTLOOK...
FRIDAY...WHILE WE HAVE NO HEADLINE ANTICIPATED AT THIS TIME THERE
IS SMALL POTENTIAL FOR AN SCA WEST-NORTHWEST FLOW LATE FRIDAY OR
FRIDAY NIGHT.
SATURDAY AND SUNDAY...CONTINUED SUB-ADVISORY CONDITIONS; ALTHOUGH,
SOME WIND GUSTS TO AROUND 20 KNOTS STILL POSSIBLE AT TIMES.
MONDAY...SUB-ADVISORY ANTICIPATED AT THIS TIME. SOME SCATTERED
SHWRS/TSTORMS EXPECTED WITH LOCALLY HIGHER WINDS/SEAS NEAR
TSTORMS.
&&
.FIRE WEATHER...
FOR FRIDAY AFTERNOON, THERE MAY BE THE RISK FOR ENHANCED WILDFIRE
SPREAD AS A WEST-NORTHWESTERLY WIND GUSTS TO BETWEEN 20 TO 25 MPH AT
TIMES. IN ADDITION, THIS WILL COMBINE WITH RELATIVE HUMIDITY VALUES
NEARING 30 PERCENT IN SOME AREAS ALONG WITH DRY FINE FUELS.
&&
.RIP CURRENTS...
SST`S ABOVE NORMAL AND JUST OFF THE COAST SSTS WELL ABOVE NORMAL
BY ALMOST 3C. THIS IS NOT GOOD ONCE IT TURNS HOT AND BEACHES ARE
UNGUARDED, SWIMMERS MAY TAKE CHANCES AT UNGUARDED LOCATIONS. BE
SMART ABOUT ANY SWIMMING EARLY THIS SEASON. ATLANTIC COASTAL WATER
TEMPS ARE WARMING --UPPER 50S TO MID 60S.
RIP CURRENT AWARENESS WEEK FOR MT HOLLY IS JUNE 7-13 WITH PSAS
VIA PUBLIC INFORMATION STATEMENTS, SOCIAL MEDIA, NOAA WEATHER
RADIO AND ANY MEDIA INTERVIEWS DESIRED (CONTACT OFFICE).
FOR RIP CURRENTS: DESPITE ANTICIPATED PROJECTIONS OF LOW OR
MODERATE RISK THROUGH THE MEMORIAL DAY WEEKEND, EARLY SEASON
FATALITIES OCCUR WHEN SWIMMING AT UNGUARDED TIMES/LOCATIONS.
WEAKER SWIMMERS OR SWIMMING IN AREAS WHERE RIP CURRENTS ARE
STRONGER (JETTIES) CAN QUICKLY BECOME LIFE THREATENING. WHEN
TRAINED LIFEGUARDS ARE NOT NEARBY, TIMELY RESCUE IS MUCH LESS
LIKELY. LETS GET THROUGH THE MONTH OF MAY WITH ALL SWIMMERS SAFE!
SWIM IN THE PRESENCE OF LIFE GUARDS! THANK YOU.
&&
.CLIMATE...
**TOP 10 WARMEST MAY CONTINUES LIKELY IN PORTIONS OF THE FORECAST
AREA**
THE FIRST 19 DAYS OF MAY IN OUR FORECAST AREA WERE AVERAGING WITHIN
ABOUT 1/2 DEGREE OF 7 DEGREES ABOVE NORMAL.
BASED ON THE ENSEMBLE AND A FORECAST THAT IS DETERMINISTICALLY
CONSERVATIVE INCLUDING OUR 330 PM MAY 20 PROJECTIONS THROUGH THE
27TH AND THEN THE 00Z/21 CONSERVATIVE FTPRHA THEREAFTER THROUGH
THE 31ST...EASILY OUTLOOKS A TOP 10 WARMEST MAY ON RECORD.
FOR PHILADELPHIA...PERIOD OF RECORD BACK TO 1874. PROJECTING AN
AVG TEMP OF 68.7 TO 69.3 OR AROUND 5 DEGREES ABOVE NORMAL AND AT
THE LEAST, 3RD WARMEST ON RECORD. WARMEST WAS 70.8 IN 1991. THEN
69.2 2004.
FOR ALLENTOWN...POR TO 1922. YESTERDAY WE WERE PROJECTING 65.0 OR
5.1 DEGREES ABOVE NORMAL AND 8TH WARMEST ON RECORD. WARMEST WAS
67.2 IN 1991.
POSTED BECAUSE WE`RE EXPECTING OUR FIRST 90 IN PHILADELPHIA BY THE
MIDDLE OF NEXT WEEK.
NORMAL FIRST DATE OF 90 OR HIGHER.
PHILADELPHIA MAY 29
ALLENTOWN MAY 30
WILMINGTON JUNE 4
ATLANTIC CITY JUNE 11.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLINE/DRAG 238
NEAR TERM...DRAG 238
SHORT TERM...DRAG 238
LONG TERM...KLINE
AVIATION...DRAG/KLINE 238
MARINE...DRAG/KLINE 238
FIRE WEATHER...
RIP CURRENTS...
CLIMATE...238
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
10 AM EDT THU MAY 21 2015
.DISCUSSION... CURRENT-THIS AFTERNOON...THE NASA VERTICAL WIND
PROFILERS SCATTERED ABOUT BREVARD COUNTY WERE DETECTING WEST TO
SOUTHWEST WINDS THROUGH 10000 FEET. THE 8AM/12Z SOUNDINGS FROM THE
FLORIDA RAOP SITES WERE INDICATING 500MB TEMPERATURES IN THE -9C TO -
10C RANGE AND A SLIGHTLY MORE MOIST ATMOSPHERE THAN WEDNESDAY.
SHOULD A SEA BREEZE BY EARLY AFTERNOON SOUTH OF CAPE CANAVERAL AND
BY MID AFTERNOON NORTH OF THE CAPE. THE HRRR IS INDICATING A LATE
AFTERNOON EAST COAST SEA BREEZE AND WEST WIND (SEA BREEZE) COLLISION
FROM SOUTHERN VOLUSIA COUNTY TO LAKE OKEECHOBEE. THIS LOOKS GOOD AND
WILL NOT CHANGE THE CURRENT FORECAST. PRIMARY CONCERNS WILL BE WIND
GUSTS AND HAIL WITH THE STRONGER STORMS.
.AVIATION...BRIEF...TOO BRIEF FOR A TEMPO GROUP...MVFR CEILINGS KLEE-
KSFB-KTIX AND SOUTH AS PATCHES OF STRATOCU MOVE NW-SE IN THE WARMING
LOWEST LAYERS.
PREVIOUS AVWX DISC...EXPECT A SIMILAR DIURNAL CONVECTIVE PATTERN TO
WED...AND AS SUCH ADDED TEMPO TS GROUPS TO DAB-SFB=TIX. ALSO HAVE
LATE EVENING VCTS (22Z-02Z) ALONG THE DAB-FPR CORRIDOR FOR LINGERING
STORMS THAT LINGER OR DRIFT OVER THE EAST COAST.
.MARINE... CURRENT-THIS AFTERNOON...BUOYS RECORDING 1 TO 2 FOOT SEAS
NEARSHORE AND TO 3 FEET AT BUOY 010 120NM OFFSHORE. THE NOAA BUOYS
AND CMAN SITES WERE RECORDING SOUTHWEST TO WEST WINDS AT 5 TO 10
KNOTS. SEA BREEZES WILL GIVE AN ONSHORE COMPONENT EARLY AFTERNOON
CAPE CANAVERAL SOUTH AND A MID TO LATE AFTERNOON ONSHORE COMPONENT
NORTH OF CAPE CANAVERAL. MAIN CONCERNS WILL BE STRONG WINDS FROM
STORMS MOVING OVER THE INDIAN RIVER LAGOON AND INTO THE NEARSHORE
WATERS.
PREVIOUS AFD
TODAY/TONIGHT...SHORT WAVE TROUGH MOVING THROUGH THE NERN CONUS WILL
SPIN UP THE TN/OH VALLEY SFC LOW AS IT MOVES ACROSS THE CAROLINAS
TODAY AND OFFSHORE. IN TURN...THIS WILL DRAG A SFC TROUGH THROUGH
NERN FL TODAY AND INTO ECFL BY TONIGHT. AHEAD OF THE SFC TROUGH...
ENHANCED RIBBON OF MOISTURE WILL SAG SEWD ACROSS THE NRN AND CTRL
CWA BY THIS AFTERNOON AND EVENING. WEAK MID LEVEL TROUGHING ALOFT
WITH EMBEDDED RIPPLES SLIDING EWD ACROSS NRN-CTRL FL SHOULD AID
DIURNAL CONVECTION.
IN LIGHT OF THIS...WENT 10-15PCT ABOVE GUIDANCE POPS FOR THIS AREA
RESULTING IN 40-50PCT FOR THE NRN 4 COS PLUS NRN BREVARD...AND 25-30
TO THE SOUTH. AS WAS THE CASE WEDNESDAY...WITH H50 TEMPS -9C/-10C
STRONG/SEVERE STORMS WILL BE POSSIBLE ALONG BOUNDARY INTERACTIONS
WITH ACTIVITY LINGERING A FEW HOURS PAST SUNSET.
SHADED MAXES A DEGREE ABOVE MAV MOS FOR THE MOST PART...GIVEN THAT
WED`S MAXES VERIFIED 1-3F HIGHER.
FRI...THE FRONTAL BOUNDARY WILL ADVANCE TO AROUND THE SOUTH CENTRAL
PENINSULA AND MAY BE HARD TO DISCERN LATER IN THE DAY. DEEPER
MOISTURE WILL LIE IN/AROUND THIS FEATURE WITH HIGHEST RAIN CHANCES
SOUTH FROM I-4. FOR NOW WILL GO WITH 20 TO 30 PERCENT ALONG THE I-4
CORRIDOR WITH 30 TO 50 POPS SOUTHWARD/INTERIOR AS AFTERNOON BOUNDARY
COLLISIONS WILL FAVOR MORE SHOWERS/ISOLD STORMS HERE. NORTHERLY FLOW
EARLY IN THE DAY WILL CONTINUE TO VEER TO NERLY THRU THE AFTERNOON.
NNW/NW STEERING FLOW REMAINS FORECAST UNDER 10 KTS SO SOME HEAVY
RAINFALL NOT OUT OF THE QUESTION. ANOTHER WARM DAY UNTIL THE ONSHORE
FLOW FILTERS INTO THE AREA BEHIND THE FRONT WITH MIDDLE 80S FORECAST
ALONG THE VOLUSIA COAST INCREASING INTO THE U80S/NEAR 90 DEGREES
FURTHER SOUTH ALONG THE COAST AND L90S...PERHAPS A FEW M90S
SOUTHWARD OVER THE INTERIOR IF ENOUGH SURFACE HEATING IS REALIZED.
OVERNIGHT LOWS IN THE U60S/L70S.
THE WEEKEND...ONSHORE FLOW IN THE LOW LEVELS WITH OCNL BREEZY
CONDITIONS POSSIBLE ALONG THE COAST. THE ECSB WILL MOVE INLAND EARLY
WITH ISOLATED SHOWERY PRECIPITATION POSSIBLE AREAWIDE BEFORE
NOON...THEN AFTERNOON/EVENING CONVECTION FAVORING THE INTERIOR
SOUTHWARD FROM ORLANDO AS WELL AS OVER THE WESTERN PENINSULA.
MORNING/EARLY AFTERNOON RAIN CHANCES FAVOR THE COAST WITH
AFTERNOON/EVENING CHANCES FAVORING THE INTERIOR ACROSS ECFL. HIGH
PRESSURE WILL RE-ESTABLISH ITSELF NORTH OF THE AREA LATER IN THE
WEEKEND PROMOTING THE DEEPER ONSHORE FLOW ACROSS THE AREA. L/M 80S
FOR HIGHS ALONG THE COAST AND UPPER 80S TO NEAR 90 DEGREES DEEPER
INTO THE INTERIOR. LOWS IN THE U60S/L70S...EXCEPT SOME M70S POSSIBLE
ALONG THE SPACE/TREASURE COASTS WHERE ONSHORE FLOW REMAINS ELEVATED.
MON-WED...THE RIDGE OF HIGH PRESSURE TO THE NORTH WILL SLIDE ONLY A
BIT FURTHER SOUTH THRU EARLY NEXT WEEK BUT WE RETAIN A DEEPER
ONSHORE FLOW OVER THE AREA. DEEPER CONVECTION NOT LIKELY BUT SHOWERY
PRECIPITATION WILL AGAIN FAVOR THE COAST IN THE MORNING/EARLY
AFTERNOON AND INTERIOR/WESTERN PENINSULA IN THE AFTERNOON IN A
PERSISTENT WEATHER PATTERN. THE EAST COAST SEA BREEZE WILL BE ACTIVE
EACH DAY PUSHING WELL INLAND IN THE AFTERNOON/EARLY EVENING.
HIGH/LOW TEMPERATURES COMPARABLE TO THE PREVIOUS PERIOD.
&&
.AVIATION...EXPECT A SIMILAR DIURNAL CONVECTIVE PATTERN TO WED...AND
AS SUCH ADDED TEMPO TS GROUPS TO DAB-SFB=TIX. ALSO HAVE LATE EVENING
VCTS (22Z-02Z) ALONG THE DAB-FPR CORRIDOR FOR LINGERING STORMS THAT
LINGER OR DRIFT OVER THE EAST COAST.
&&
.MARINE...TODAY/TONIGHT...SW FLOW AVERAGING 10-13KT WILL GIVE WAY TO
ONSHORE SEA BREEZE CIRC NEAR THE COAST IN THE AFTERNOON. SEAS 2-3FT
WITH HIGHER WINDS AND SEAS IN OFFSHORE MOVING STORMS...ESPECIALLY
NORTH OF THE CAPE AND NEAR THE COAST.
FRI...WEAK FRONTAL BOUNDARY IS EXPECTED TO SETTLE INTO SOUTH CENTRAL
FLORIDA AND WEAKEN FURTHER. NORTHERLY WINDS BEHIND THIS FEATURE WILL
VEER TO NNE INTO THE AFTERNOON...THEN NE/ENE THROUGH THE NIGHT. WIND
SPEEDS SHOULD BE AOB 15 KNOTS. SEAS 2-3 FT DURING THE DAY INCREASING
AWAY FROM THE COAST UP TO 4 FT FRI NIGHT.
SAT-MON...HIGH PRESSURE SLOWLY RE-ESTABLISHES ITSELF NORTH OF THE
WATERS WITH DEEPENING LOW-LEVEL ONSHORE FLOW. LIGHT SHOWERY
PRECIPITATION WILL BE FORECAST WITH FOCUS OF ATLC COASTAL SHOWERS AT
NIGHT AND IN THE MORNINGS ALONG THE COAST AND ACTIVITY FOCUSING
DEEPER INLAND IN THE AFTERNOON WITH THE ECSB. A STRONGER PRESSURE
GRADIENT WILL DEVELOP OVER THE AREA THIS WEEKEND WITH CAUTIONARY
STATEMENTS POSSIBLE AS EARLY AS SAT AFTERNOON FOR WINDS OFFSHORE
PERHAPS CONTINUING WELL OFFSHORE INTO SUN. OTHERWISE WINDS 10-15 KTS
INTRACOASTAL/NEAR SHORE WATERS. SEAS 3-4 FT ON SAT AND MAYBE
INCREASING TOWARDS 5 FT LATE IN THE DAY WITH THE STRONGER
WINDS...WITH EAST FETCH BUILDING SEAS TO 4-6 FT INTO SAT NIGHT INTO
SUN/MON OVER THE OPEN ATLC
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 92 69 86 71 / 50 20 10 10
MCO 93 72 93 72 / 40 20 30 20
MLB 91 71 88 75 / 30 30 20 20
VRB 91 71 89 74 / 20 30 30 20
LEE 92 71 90 71 / 40 20 30 20
SFB 93 72 90 71 / 50 20 30 20
ORL 94 73 90 72 / 40 20 30 20
FPR 90 71 89 73 / 20 30 30 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...WIMMER
LONG TERM/IMPACT WX...BRAGAW
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
140 AM EDT THU MAY 21 2015
.PREV DISCUSSION... /ISSUED 742 PM EDT WED MAY 20 2015/
EVENING UPDATE...
UPPER DISTURBANCE PUSHING INTO NW AL IS SPARKING CONVECTION THERE...
WITH ONGOING CONVECTION STILL NOTED ACROSS EAST AND SE AL. THESE
STORMS MAY PUSH INTO THE COLUMBUS AREA BY 9 PM... BUT EXPECT SOME
WEAKENING... SO MAY BE MOSTLY SHOWERS. THE GREATER CONCERN IS THE
CONVECTION TO THE NORTH WHERE HAS BETTER UPPER SHORT WAVE SUPPORT.
THIS CONVECTION WILL LIKELY SPREAD ISOLATED TO POSSIBLY STILL
SCATTERED THUNDERSTORMS INTO NW GA BETWEEN 9-10 PM... THEN SPREAD
ACROSS THE REST OF NORTH GA THROUGH MIDNIGHT AND COULD PERSIST UNTIL
AROUND 2-3 AM THU MORNING. NO SEVERE STORMS ARE EXPECTED... WITH THE
MAIN THREAT BEING OCCASIONAL CLOUD TO GROUND LIGHTNING AND BRIEF
WIND GUSTS TO 35-40MPH OR SO. WILL UP POPS OVER THE NW ZONES AS GET
MORE CONFIDENT THE CONVECTION WILL HOLD TOGETHER... BUT OTHERWISE...
THE CURRENT FORECAST LOOK ON TRACK. 39
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
/ISSUED AT 336 PM EDT WED MAY 20 2015/
MAIN FORECAST CONCERN IS WITH PRECIP POTENTIAL THIS EVENING INTO THE
EARLY MORNING AS A SHORTWAVE AND SOME ENHANCED MOISTURE APPROACHES
THE CWA FROM THE WEST. CURRENTLY A BAND OF SHOWERS AND STORMS IS
PUSHING INTO WESTERN ALABAMA AHEAD OF THIS DISTURBANCE WITH A WEAK
TRANSLATED SFC LOW. WHILE SOME HI-RES SOLUTIONS DO NOT APPEAR TO
SUPPORT THIS HOLDING TOGETHER AND PUSHING INTO WEST GA...SOME
PREVIOUS RAP SOLUTIONS SUPPORTED IT AND WILL NEED TO BE CLOSELY
MONITORED ESPECIALLY IF SOME OUTFLOW BOUNDARIES OR OTHER MESOSCALE
FORCING COMES TO AID. THIS MAY RESULT IN UPPING POPS IN WESTERN
PORTIONS OF THE AREA BY THIS EVENING. STILL SOME MLCAPE NEAR 1000
J/KG AND DECENT DCAPE IN PLACE. IF ANY STORM DEVELOPMENT CAN
MUSTER...THERE COULD STILL BE STRONG DOWNDRAFT WINDS EVEN THOUGH IT
IS A SHEAR DEPRIVED ENVIRONMENT. KEEPING BEST CHANCE POPS MAINLY
NORTH OF I-20 CORRIDOR INTO THE EARLY MORNING WITH THE SHORTWAVE
INFLUENCE.
PROGGED THERMAL PROFILES INDICATE GOOD DRYING OF THE COLUMN FOR
THURSDAY AND NOW BETTER AGREEMENT WITH A NOTABLE CAPPING INVERSION
ABOVE 850 MB. HAVE TRIMMED BACK POPS NOW TO ONLY HAVE A SLIGHT
CHANCE IN THE FAR SOUTHERN TIER FOR THE AFTERNOON...OTHERWISE
LOOKING TO STAY TOO DRY AND STABLE. WINDS LOOK TO BE KICKING IN WITH
THE STRENGTHENING PRESSURE GRADIENT AND AFTERNOON MIXING. WHILE
CURRENTLY LOOKING TO STAY A BIT BELOW CRITERIA...WILL NEED TO KEEP
AN EYE ON TRENDS FOR ANY FIRE DANGER CONCERNS WITH ALREADY DRY FUELS
/THOUGH MAY BE ALTERED WITH AFOREMENTIONED PRECIP CHANCES/. TEMPS
THURSDAY LOOK TO HAVE A STRONG GRADIENT WITH BELOW NORMAL HIGHS IN
THE MID/UPPER 70S FOR THE NW TO THE LOW 90S SE.
BAKER
LONG TERM /FRIDAY THROUGH WEDNESDAY/...
/ISSUED AT 336 PM EDT WED MAY 20 2015/
HAVE MADE A FEW MINOR ADJUSTMENTS TO POP AND WEATHER THROUGH THE
WEEKEND. LATEST LONG TERM MODELS HINT AT A MORE PROMINENT SURFACE
HIGH KEEPING MOISTURE TO THE WEST LARGELY AT BAY THROUGH
SUNDAY...WITH ONLY PORTIONS OF WESTERN AND NORTHERN GEORGIA AT
RISK FOR AN ISOLATED STORM. HAVE SCALED POPS BACK SOMEWHAT AS A
RESULT.
31
PREV DISCUSSION... /ISSUED 424 AM EDT WED MAY 20 2015/
LONG TERM PERIOD BEGINS A BIT DRIER AS THE FRONTAL SYSTEM WILL BE
SOUTH AND EAST OF THE AREA. HIGH PRESSURE BUILDING IN FROM THE
NORTHERN PLAINS AND MID WESTERN STATES BECOMES CENTERED OFF THE
MID ATLANTIC COAST AND STAYS THERE THROUGH THE WEEKEND. THIS RIDGE
CONTINUES TO ROTATE AND KEEPS THE DEEPER MOISTURE NORTH AND WEST
OF THE REGION THROUGH THE BEGINNING OF NEXT WEEK. THERE IS STILL
SOME MID AND UPPER LEVEL MOISTURE AROUND THE AREA SO WILL KEEP
SLIGHT CHANCE DIURNALLY DRIVEN POPS IN THE FORECAST DAYS 3-5. BY
TUESDAY THE RIDGE IS BEGINNING TO WEAKEN AND TRANSITION INTO MORE
OF A BERMUDA LIKE RIDGE. THIS WILL ALLOW DEEPER MOISTURE TO MOVE
IN FROM THE WEST ASSOCIATED WITH A WEAKENING FRONTAL BOUNDARY.
LOOKING AT INSTABILITIES INCREASING A BIT TUESDAY/WEDNESDAY ALONG
WITH PWS SO WILL INCREASE TO CHANCE POPS DAYS 6 AND 7.
01
&&
.AVIATION...
06Z UPDATE...
MODELS ARE CONTINUING TO ADD SOME MVFR CIGS TOWARDS DAWN. ANY
CIGS SHOULD CLEAR OUT SHORTLY AFTER SUNRISE...WITH VFR CONDITIONS
EXPECTED THROUGH THE PERIOD. WINDS WILL SHIFT MORE TO THE NW LATER
THIS AFTERNOON WITH FREQUENT GUSTS TO AROUND 20KT.
//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 85 56 81 59 / 10 5 0 5
ATLANTA 80 58 80 63 / 10 0 0 5
BLAIRSVILLE 74 48 74 54 / 30 5 0 5
CARTERSVILLE 79 53 79 56 / 10 0 0 5
COLUMBUS 88 61 84 65 / 10 0 0 5
GAINESVILLE 80 55 78 59 / 10 0 0 5
MACON 89 59 85 63 / 10 0 0 5
ROME 77 52 79 55 / 10 0 0 5
PEACHTREE CITY 83 54 81 60 / 10 0 0 5
VIDALIA 92 65 86 66 / 20 0 0 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
637 PM MDT FRI MAY 22 2015
.SHORT TERM...(TONIGHT THROUGH SATURDAY AFTERNOON)
ISSUED AT 247 PM MDT FRI MAY 22 2015
LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS CLOSED LOW OVER
THE SW US...WITH A NEGATIVELY TILTED TROUGH CENTERED OVER THE
NEBRASKA PANHANDLE/NORTHEAST COLORADO. SATELLITE SHOWS CLEARING
BEGINS TO MOVE INTO THE SW PART OF THE CWA...WITH STRATUS/SHOWERS
TRANSITIONING NORTHWARDS. THUNDERSTORMS ARE ALREADY BEGINNING TO
FIRE ALONG PALMER DIVING ALONG NORTHERN EXTENT OF SURFACE LOW IN
EASTERN COLORADO.
REGARDING SEVERE THREAT THIS AFTERNOON THROUGH TONIGHT...WITH
CLEARING TAKING PLACE IN THE SW RAP AND OBJECTIVE ANALYSIS INDICATED
500-1500 J/KG OF SB CAPE ALREADY DEVELOPING...AND GUIDANCE WOULD
FAVOR THIS DEVELOPING INTO THE SW PART OF THE CWA (ASSOCIATED WITH
CLEARING. GOOD VEERING PROFILES ARE IN PLACE ALONG AND JUST NORTH OF
THE SURFACE LOW WHERE RAP IS HINTING AT HELICITY VALUES APPROACHING
250 M2/S2 BY 00Z. ORGANIZED SUPERCELL/TORNADO THREAT SEEMS TO BE
TIED TO THIS SURFACE LOW AND WOULD FAVOR THE SOUTHWEST PART OF OUR
CWA. DEEP SPEED SHEER CONTINUES OVERNIGHT AND GUIDANCE INDICATES
AROUND 1000 J/KG OF MU CAPE (POSSIBLY HIGHER IF NAM IS TO BE
TRUSTED). STRONG ISENTROPIC SIGNAL CONTINUES THROUGH THE NIGHTTIME
PERIOD...AND SEVERAL LOBES OF VORTICITY AND OMEGA ROTATE THROUGH
THE REGION. THIS SHOULD COMBINE TO CREATE
SHOWERS/THUNDERSTORMS...POSSIBLY A SEVERE HAIL THREAT IF WE SEE ANY
THUNDERSTORMS. NOT AS SURE ABOUT WIND THREAT CONSIDERING THE
PROFILES AND STABLE LOWER LEVELS.
FOG/STRATUS/DRIZZLE WILL BE POSSIBLE ALL NIGHT WITH GOOD BL MOISTURE
FLUX THROUGH SATURDAY MORNING...TRANSITIONING EASTWARD. WITH BETTER
SHOWER/THUNDERSTORM/DRIZZLE COVERAGE DENSE FOG MAY NOT BE AS MUCH OF
A CONCERN DUE TO THE INCREASE IN MIXING. WILL NEED TO MONITOR AS
LESS MIXING WOULD RESULT IN DENSE FOG DUE TO THE LONG FETCH
UPSLOPE/MAGNITUDE OF MOISTURE ADVECTION.
GUIDANCES SHOWS TWO DISTINCT SHORTWAVE TROUGHS SATURDAY
MORNING...ONE IN THE SOUTHERN PLAINS AND ANOTHER DEVELOPING INTO
NORTHERN COLORADO BY LATE AFTERNOON AS THE H3 JET BEGINS TO SHIFT
EASTWARD. THERE SEEMS TO BE A LULL IN ACTIVITY BETWEEN THESE
FEATURES LIKELY DUE TO SOME WEAK SUBSIDENCE...AND NAM IS REALLY
HITTING THIS DRY PERIOD HARDER COMPARED TO GFS/ECMWF. DECIDED OT
TIMING OUT THE LULL TO FAVOR LOWER POPS SAT MORNING...BEFORE
COVERAGE REDEVELOPS IN THE AFTERNOON. BETTER PRECIP SIGNAL IS AGAIN
IN EASTERN COLORADO BY MID AFTERNOON. CAPE PROFILES ARE MUCH MORE
ROBUST ACROSS THE MAJORITY OF THE CWA...AS WELL AS GOOD SHEER. AS A
RESULT WE WILL PROBABLY SEE A BETTER SEVERE THREAT SATURDAY
AFTERNOON THAN TODAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 247 PM MDT FRI MAY 22 2015
THE SLOW-MOVING UPPER LOW OVER UT/CO AT THE BEGINNING OF THE PERIOD
IS FORECAST TO LIFT NORTHEAST INTO THE DAKOTAS BY EARLY NEXT
WEEK...BUT NOT BEFORE SWINGING SEVERAL MORE SHORT WAVE TROUGHS
AROUND ITS PERIPHERY ACROSS THE FORECAST AREA. THE PATTERN WILL
BE SOMEWHAT LESS ACTIVE FOR THE MIDDLE OF THE WEEK WITH
THUNDERSTORM POTENTIAL A BIT MORE OF THE HIT-AND-MISS VARIETY
BEFORE ANOTHER TROUGH DEVELOPS IN THE WEST TOWARD THE END OF THE
WEEK. OVERALL...THE LONG RANGE PERIOD WILL BE ONE OF DECREASING
PRECIPITATION POTENTIAL WITH TEMPERATURES WARMING BACK TO SEASONAL
NORMS IN THE 70S/LOW 80S FOR HIGHS AND 50S FOR LOWS.
TO START THE EXTENDED PERIOD...THERE IS DECENT POTENTIAL FOR
STRONG TO SEVERE STORMS SATURDAY AFTERNOON-EVENING AS THE UPPER
LOW MOVES INTO WESTERN COLORADO AND A SURFACE DRYLINE SETS UP OVER
EC/SE COLORADO. A 100 KT 250 MB JET STREAK WILL BE RUNNING UP THE
EAST SIDE OF THE UPPER LOW ALONG THE C0-KS BORDER DURING PEAK
HEATING...AND WITH LOW LEVEL MOISTURE ALREADY IN PLACE...A ROUND
OF SEVERE STORMS SEEMS PROBABLE IN EASTERN COLORADO AND WESTERN
KANSAS. STORMS WILL MOVE QUICKLY NORTH INTO NEBRASKA DURING THE
EVENING.
SUNDAY AFTERNOON/NIGHT...THE TAIL END OF THE UPPER LOW/TROUGH
WILL FINALLY SWING THROUGH THE AREA SO CONTINUED CHANCE POPS AS A
RESULT. WEAK SUBSIDENCE BEHIND THIS FEATURE ON MONDAY WILL PROVIDE
A LITTLE RELIEF FROM THE ONSLAUGHT OF RECENT PRECIPITATION.
MID WEEK WILL BE CHARACTERIZED BY A QUASI ZONAL FLOW WITH A FEW
WEAK EMBEDDED TROUGH WHICH WILL KEEP SLIGHT CHANCE TO CHANCE POPS
FOR THUNDERSTORMS BUT OTHERWISE ACCOMPANIED BY TEMPERATURES MORE
TYPICAL OF LATE MAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 557 PM MDT FRI MAY 22 2015
CONDITIONS AT GLD WILL START OUT IFR WITH A FEW SHOWERS MOVING
ACROSS THE AREA BETWEEN ABOUT 04Z AND 08Z LOWERING CONDITIONS TO
LIFR. DRIZZLE IS EXPECTED AFTER 08Z WITH CEILINGS LOWERING
CONDITIONS TO VLIFR THROUGH ABOUT 14Z. AFTER 14Z...CONDITIONS ARE
EXPECTED TO GRADUALLY IMPROVE WITH VFR EXPECTED AFTER 18Z.
MCK WILL BOUNCE BETWEEN IFR AND LIFR THROUGH ABOUT 04Z WITH LIFR
DROPPING TO VLIFR AFTER 08Z DUE MAINLY TO LOW CEILINGS WITH
SHOWERS AND DRIZZLE CONTINUING ABOUT 16Z. AFTER 16Z...CONDITIONS
WILL IMPROVE SLOWLY THROUGH THE DAY WITH MAINLY LIFR TO PREVAIL
THROUGH THE REMAINDER OF THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...DLF
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS JACKSON KY
152 AM EDT THU MAY 21 2015
.UPDATE...
ISSUED AT 152 AM EDT THU MAY 21 2015
LIGHT RAIN SHOWERS ARE PROGRESSING ACROSS PORTIONS OF THE REGION
TONIGHT IN ASSOCIATION WITH WEAK WAVE PASSING ACROSS THE OHIO AND
TN VALLEYS. DID BRING POPS DOWN A BIT JUST GIVEN THE LIGHT NATURE
OF THIS ACTIVITY. OTHERWISE MADE SOME MINOR ADJUSTMENTS TOWARDS
LATEST OBS AND TRENDS.
UPDATE ISSUED AT 1100 PM EDT WED MAY 20 2015
LIGHT RAIN SHOWERS ARE MOVING IN FROM THE WEST...HOWEVER THE
RETURNS CONTINUE TO BE VERY LIGHT. THE LAST FEW RUNS OF THE HRRR
HAVE COME IN WITH LESS AREAL COVERAGE THROUGH THE NIGHT. WILL
MAINTAIN LOW END LIKELY POPS...BUT CUT BACK THE QPF...AS A FEW
HUNDREDTHS TO SEVERAL HUNDREDTHS OF AN INCH AT BEST LOOK MORE
REASONABLE AT THIS POINT. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 853 PM EDT WED MAY 20 2015
LIGHT PRECIPITATION IS TRYING TO MAKE IT IN FROM THE WEST...BUT
SO FAR...THE LOW LEVEL DRY AIR HAS BEEN HOLDING IT TO A FEW
SPRINKLES AT BEST. THE LATEST HRRR STILL CONTINUES TO SHOW SOME
BETTER AREAL COVERAGE EVENTUALLY SHIFTING ACROSS EASTERN KENTUCKY
THROUGH THE OVERNIGHT...AS A SHORT WAVE TROUGH DRAWS CLOSER TO
THE AREA. WILL STICK WITH THE CURRENT FORECAST AND MAINLY ADJUST
THE POP TIMING ACCORDING TO THE LATEST RADAR AND SHORT TERM MODEL
GUIDANCE TRENDS. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 345 PM EDT WED MAY 20 2015
A GENERALLY ZONAL PATTERN WAS IN PLACE FROM THE PLAINS INTO THE
EASTERN CONUS THIS AFTERNOON. A SHORTWAVE TROUGH WAS MOVING EAST
IN THIS FLOW AND WAS OVER THE MS VALLEY REGION. FURTHER TO THE
NORTH OF THE REGION...AN UPPER LEVEL LOW WAS DROPPING SOUTH ACROSS
THE HUDSON BAY REGION. SFC HIGH PRESSURE AND SHORTWAVE RIDGING
THAT IS DEPARTING HAVE BROUGHT MOSTLY SUNNY SKIES TO THE REGION.
HOWEVER...HIGH CLOUDS HAVE BEEN INCREASING THIS AFTERNOON WITH MID
LEVEL CLOUDS AS CLOSE AS CENTRAL KY. RADAR RETURNS HAVE RAIN
SHOWERS ACROSS SOUTHERN IL AND INTO PARTS OF IN AS WELL AS WESTERN
KY AND MIDDLE TN. SOME THUNDERSTORMS ARE OCCURRING OVER SOUTHERN
MIDDLE TN. THESE SHOWERS AND STORMS ARE IN ASSOCIATION WITH THE
SHORTWAVE TROUGH MOVING FROM THE MS VALLEY AND INTO THE LOWER OH
AND TN VALLEY REGIONS. AT THE SFC...A LOW PRESSURE SYSTEM IS
NEARING THE MID MS VALLEY REGION.
THE SHORTWAVE TROUGH IS EXPECTED TO MOVE EAST ACROSS THE REGION
TONIGHT...WITH THE ATMOSPHERE SATURATING FROM THE TOP DOWN.
ANOTHER SHORTWAVE IS EXPECTED TO ROTATE AROUND THE UPPER LOW THAT
WILL MOVE FROM THE HUDSON AND JAMES BAY REGION INTO QUEBEC BY THE
END OF THE PERIOD. THIS SECOND SHORTWAVE WILL USHER IN A COLDER
AND DRIER AIR MASS INTO THE REGION. AT THE SFC...THE LOW PRESSURE
SYSTEM IS EXPECTED TO TRACK EAST JUST TO THE SOUTH OF THE REGION
TONIGHT WITH THIS SYSTEM REACHING THE EASTERN SEABOARD ON THURSDAY
EVENING. MEANWHILE...SFC HIGH PRESSURE WILL BUILD EAST INTO THE
REGION BEHIND THIS SFC LOW FOR THU NIGHT.
THE SHORTWAVE TROUGH MOVING ACROSS THE REGION TONIGHT AND THE SFC
LOW PASSING TO OUR SOUTH COMBINATION SHOULD BRING NUMEROUS SHOWERS
TO THE REGION BY LATE THIS EVENING INTO THE OVERNIGHT HOURS.
DEEPER MOISTURE AND SOMEWHAT BETTER INSTABILITY IS ANTICIPATED
NEAR THE TN BORDER CLOSER TO THE SFC LOW TRACK...AND A STRAY
THUNDERSTORM CANNOT BE RULED OUT NEAR THE TN BORDER AND THE
KY/TN/VA TRI STATE AREA THIS EVENING. THE LAST TWO GFS RUNS BRING
PRECIPITATION TO MUCH OF THE AREA TONIGHT. THE GFS HAD BEEN
CONSISTENTLY DRIER THAN MUCH OF THE GUIDANCE LEADING UP TO THIS
EVENT. WITH THE GFS NOW BRINGING SHOWERS TO THE AREA AS
WELL...POPS HAVE BEEN RAISED INTO THE LIKELY RANGE AS MEASURABLE
PRECIPITATION APPEARS PROBABLE FOR MOST LOCATIONS. LINGERING LOW
LEVEL MOISTURE AND WINDS BRIEFLY GOING UPSLOPE BEHIND THE
DEPARTING LOW WILL BRING THE THREAT FOR LINGERING SHOWERS INTO THE
DAY ON THURSDAY.
HIGH PRESSURE WILL USHER IN A COLDER AND DRIER AIR MASS LATE THU
INTO THU NIGHT...WITH WIDESPREAD LOW TO MID 40S ANTICIPATED. SOME
OF THE COOP MOS GUIDANCE SUGGESTS THAT COLDEST SPOTS IN THE NORTH
COULD REACH 39 OR 40...SO A FEW OF THE NORMALLY COLDER SPOTS MAY
NEED TO BE LOWERED A DEGREE OR TWO AS THU NIGHT APPROACHES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 315 PM EDT WED MAY 20 2015
NORTHWESTERLY FLOW ALOFT WILL DOMINATE THE REGION AS AN UPPER LEVEL
RIDGE BUILDS INTO EASTERN KENTUCKY AT THE START OF THE PERIOD. BY
THE SECOND HALF OF THE WEEKEND...THIS RIDGE WILL STRENGTHEN AND PUSH
EWD TOWARD THE EAST COAST ALLOWING FOR A TRANSITION TO SOUTHERLY
FLOW AT MID AND UPPER LEVELS. AN ACTIVE WEATHER PATTERN IS THEN IN
STORE FOR EASTERN KENTUCKY AS THE SOUTHERLY FLOW BRINGS AN INCREASE
IN MOISTURE AND A SERIES OF IMPULSES THROUGH THE END OF THE PERIOD.
AT THE SURFACE...THE FIRST PART OF MEMORIAL DAY WEEKEND WILL FEATURE
DRY AND BEAUTIFUL SPRING WEATHER WITH TEMPERATURES TOPPING OUT IN
THE LOW TO MID 70S FRIDAY AND SATURDAY. THE SURFACE RIDGE THEN
SHIFTS EAST OF THE REGION SUNDAY AS THE UPPER LEVEL RIDGE
STRENGTHENS OVER THE SOUTHEASTERN US...ALLOWING FOR MOISTURE AND
CLOUD COVER TO INCREASE. THERE WILL BE CHANCES FOR SHOWERS AND
DIURNALLY DRIVEN CONVECTION SUNDAY AFTERNOON THROUGH WEDNESDAY WITH
INSTABILITY INCREASING EACH DAY. TEMPERATURES WILL BE DEPENDENT ON
CONVECTIVE TIMING/COVERAGE...BUT A GENERAL WARMING TREND FROM THE
70S ON FRIDAY INTO THE MID 80S BY WEDNESDAY IS ANTICIPATED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 134 AM EDT THU MAY 21 2015
SEEING A FEW LIGHT RAIN SHOWERS MOVE ACROSS THE REGION
TONIGHT...HOWEVER WE ARE STRUGGLING GIVEN THE DRIER AIR IN PLACE
AND THE GENERALLY SHEARED OUT SYSTEM. THOSE WHO DID RECEIVE RAIN
WILL HAVE TO BEST CHANCES OF SEEING FALLING CIGS OVERNIGHT WITH A
BIT MORE LOW LEVEL MOISTURE TO PLAY WITH. GENERALLY SLOWLY BRING
MOST SITES TO MVFR BETWEEN 07Z AND 09Z AND RIGHT NOW KEPT WITH
THE LOWER VIS...HOWEVER THINK THE BIGGER RESTRICTION WILL BE THE
CEILINGS FOR MUCH OF THE PERIOD. TOWARD DAWN DO BRING SITES DOWN
TO IFR WITH SOUNDINGS INDICATING THE LOW LEVEL MOISTURE TRAPPED IN
THE LOWER LAYERS AND ALSO INTRODUCED SOME DRIZZLE. DID OPT TO MIX
THIS OUT BY EARLY AFTERNOON TODAY AND BRING TAFS SITES BACK TO
MVFR. OTHERWISE GENERALLY LIGHT WINDS THROUGH THE PERIOD AND
EVENTUALLY COMING OUT OF THE NW THIS AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...JP
LONG TERM...JVM
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
135 AM EDT THU MAY 21 2015
.UPDATE...
ISSUED AT 1100 PM EDT WED MAY 20 2015
LIGHT RAIN SHOWERS ARE MOVING IN FROM THE WEST...HOWEVER THE
RETURNS CONTINUE TO BE VERY LIGHT. THE LAST FEW RUNS OF THE HRRR
HAVE COME IN WITH LESS AREAL COVERAGE THROUGH THE NIGHT. WILL
MAINTAIN LOW END LIKELY POPS...BUT CUT BACK THE QPF...AS A FEW
HUNDREDTHS TO SEVERAL HUNDREDTHS OF AN INCH AT BEST LOOK MORE
REASONABLE AT THIS POINT. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 853 PM EDT WED MAY 20 2015
LIGHT PRECIPITATION IS TRYING TO MAKE IT IN FROM THE WEST...BUT
SO FAR...THE LOW LEVEL DRY AIR HAS BEEN HOLDING IT TO A FEW
SPRINKLES AT BEST. THE LATEST HRRR STILL CONTINUES TO SHOW SOME
BETTER AREAL COVERAGE EVENTUALLY SHIFTING ACROSS EASTERN KENTUCKY
THROUGH THE OVERNIGHT...AS A SHORT WAVE TROUGH DRAWS CLOSER TO
THE AREA. WILL STICK WITH THE CURRENT FORECAST AND MAINLY ADJUST
THE POP TIMING ACCORDING TO THE LATEST RADAR AND SHORT TERM MODEL
GUIDANCE TRENDS. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 345 PM EDT WED MAY 20 2015
A GENERALLY ZONAL PATTERN WAS IN PLACE FROM THE PLAINS INTO THE
EASTERN CONUS THIS AFTERNOON. A SHORTWAVE TROUGH WAS MOVING EAST
IN THIS FLOW AND WAS OVER THE MS VALLEY REGION. FURTHER TO THE
NORTH OF THE REGION...AN UPPER LEVEL LOW WAS DROPPING SOUTH ACROSS
THE HUDSON BAY REGION. SFC HIGH PRESSURE AND SHORTWAVE RIDGING
THAT IS DEPARTING HAVE BROUGHT MOSTLY SUNNY SKIES TO THE REGION.
HOWEVER...HIGH CLOUDS HAVE BEEN INCREASING THIS AFTERNOON WITH MID
LEVEL CLOUDS AS CLOSE AS CENTRAL KY. RADAR RETURNS HAVE RAIN
SHOWERS ACROSS SOUTHERN IL AND INTO PARTS OF IN AS WELL AS WESTERN
KY AND MIDDLE TN. SOME THUNDERSTORMS ARE OCCURRING OVER SOUTHERN
MIDDLE TN. THESE SHOWERS AND STORMS ARE IN ASSOCIATION WITH THE
SHORTWAVE TROUGH MOVING FROM THE MS VALLEY AND INTO THE LOWER OH
AND TN VALLEY REGIONS. AT THE SFC...A LOW PRESSURE SYSTEM IS
NEARING THE MID MS VALLEY REGION.
THE SHORTWAVE TROUGH IS EXPECTED TO MOVE EAST ACROSS THE REGION
TONIGHT...WITH THE ATMOSPHERE SATURATING FROM THE TOP DOWN.
ANOTHER SHORTWAVE IS EXPECTED TO ROTATE AROUND THE UPPER LOW THAT
WILL MOVE FROM THE HUDSON AND JAMES BAY REGION INTO QUEBEC BY THE
END OF THE PERIOD. THIS SECOND SHORTWAVE WILL USHER IN A COLDER
AND DRIER AIR MASS INTO THE REGION. AT THE SFC...THE LOW PRESSURE
SYSTEM IS EXPECTED TO TRACK EAST JUST TO THE SOUTH OF THE REGION
TONIGHT WITH THIS SYSTEM REACHING THE EASTERN SEABOARD ON THURSDAY
EVENING. MEANWHILE...SFC HIGH PRESSURE WILL BUILD EAST INTO THE
REGION BEHIND THIS SFC LOW FOR THU NIGHT.
THE SHORTWAVE TROUGH MOVING ACROSS THE REGION TONIGHT AND THE SFC
LOW PASSING TO OUR SOUTH COMBINATION SHOULD BRING NUMEROUS SHOWERS
TO THE REGION BY LATE THIS EVENING INTO THE OVERNIGHT HOURS.
DEEPER MOISTURE AND SOMEWHAT BETTER INSTABILITY IS ANTICIPATED
NEAR THE TN BORDER CLOSER TO THE SFC LOW TRACK...AND A STRAY
THUNDERSTORM CANNOT BE RULED OUT NEAR THE TN BORDER AND THE
KY/TN/VA TRI STATE AREA THIS EVENING. THE LAST TWO GFS RUNS BRING
PRECIPITATION TO MUCH OF THE AREA TONIGHT. THE GFS HAD BEEN
CONSISTENTLY DRIER THAN MUCH OF THE GUIDANCE LEADING UP TO THIS
EVENT. WITH THE GFS NOW BRINGING SHOWERS TO THE AREA AS
WELL...POPS HAVE BEEN RAISED INTO THE LIKELY RANGE AS MEASURABLE
PRECIPITATION APPEARS PROBABLE FOR MOST LOCATIONS. LINGERING LOW
LEVEL MOISTURE AND WINDS BRIEFLY GOING UPSLOPE BEHIND THE
DEPARTING LOW WILL BRING THE THREAT FOR LINGERING SHOWERS INTO THE
DAY ON THURSDAY.
HIGH PRESSURE WILL USHER IN A COLDER AND DRIER AIR MASS LATE THU
INTO THU NIGHT...WITH WIDESPREAD LOW TO MID 40S ANTICIPATED. SOME
OF THE COOP MOS GUIDANCE SUGGESTS THAT COLDEST SPOTS IN THE NORTH
COULD REACH 39 OR 40...SO A FEW OF THE NORMALLY COLDER SPOTS MAY
NEED TO BE LOWERED A DEGREE OR TWO AS THU NIGHT APPROACHES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 315 PM EDT WED MAY 20 2015
NORTHWESTERLY FLOW ALOFT WILL DOMINATE THE REGION AS AN UPPER LEVEL
RIDGE BUILDS INTO EASTERN KENTUCKY AT THE START OF THE PERIOD. BY
THE SECOND HALF OF THE WEEKEND...THIS RIDGE WILL STRENGTHEN AND PUSH
EWD TOWARD THE EAST COAST ALLOWING FOR A TRANSITION TO SOUTHERLY
FLOW AT MID AND UPPER LEVELS. AN ACTIVE WEATHER PATTERN IS THEN IN
STORE FOR EASTERN KENTUCKY AS THE SOUTHERLY FLOW BRINGS AN INCREASE
IN MOISTURE AND A SERIES OF IMPULSES THROUGH THE END OF THE PERIOD.
AT THE SURFACE...THE FIRST PART OF MEMORIAL DAY WEEKEND WILL FEATURE
DRY AND BEAUTIFUL SPRING WEATHER WITH TEMPERATURES TOPPING OUT IN
THE LOW TO MID 70S FRIDAY AND SATURDAY. THE SURFACE RIDGE THEN
SHIFTS EAST OF THE REGION SUNDAY AS THE UPPER LEVEL RIDGE
STRENGTHENS OVER THE SOUTHEASTERN US...ALLOWING FOR MOISTURE AND
CLOUD COVER TO INCREASE. THERE WILL BE CHANCES FOR SHOWERS AND
DIURNALLY DRIVEN CONVECTION SUNDAY AFTERNOON THROUGH WEDNESDAY WITH
INSTABILITY INCREASING EACH DAY. TEMPERATURES WILL BE DEPENDENT ON
CONVECTIVE TIMING/COVERAGE...BUT A GENERAL WARMING TREND FROM THE
70S ON FRIDAY INTO THE MID 80S BY WEDNESDAY IS ANTICIPATED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 134 AM EDT THU MAY 21 2015
SEEING A FEW LIGHT RAIN SHOWERS MOVE ACROSS THE REGION
TONIGHT...HOWEVER WE ARE STRUGGLING GIVEN THE DRIER AIR IN PLACE
AND THE GENERALLY SHEARED OUT SYSTEM. THOSE WHO DID RECEIVE RAIN
WILL HAVE TO BEST CHANCES OF SEEING FALLING CIGS OVERNIGHT WITH A
BIT MORE LOW LEVEL MOISTURE TO PLAY WITH. GENERALLY SLOWLY BRING
MOST SITES TO MVFR BETWEEN 07Z AND 09Z AND RIGHT NOW KEPT WITH
THE LOWER VIS...HOWEVER THINK THE BIGGER RESTRICTION WILL BE THE
CEILINGS FOR MUCH OF THE PERIOD. TOWARD DAWN DO BRING SITES DOWN
TO IFR WITH SOUNDINGS INDICATING THE LOW LEVEL MOISTURE TRAPPED IN
THE LOWER LAYERS AND ALSO INTRODUCED SOME DRIZZLE. DID OPT TO MIX
THIS OUT BY EARLY AFTERNOON TODAY AND BRING TAFS SITES BACK TO
MVFR. OTHERWISE GENERALLY LIGHT WINDS THROUGH THE PERIOD AND
EVENTUALLY COMING OUT OF THE NW THIS AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...JP
LONG TERM...JVM
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1135 AM CDT THU MAY 21 2015
.UPDATE...
FORECAST REASONING FROM SOUNDING DISCUSSION ALONG WITH
RADAR...MESO-ANALYSIS...AND HRRR MODEL TRENDS ALL SUPPORT RAISING
THE POP TO LIKELY RANGE FOR MUCH OF THE AREA THE REMAINDER OF
TODAY. TEMPERATURES WERE RISING A BIT FASTER AND ALREADY REACHED
THE FORECAST HIGHS. ANOTHER RISE OF A DEGREE OR TWO IS
POSSIBLE...HOWEVER INCREASING SHOWERS AND THUNDERSTORMS AND
ASSOCIATED CLOUD COVER WILL BE CAPPING OFF THE TEMPERATURES AND
CAUSING A GENERAL DOWNTREND AS THE AFTERNOON PROGRESSES. UPDATES
HAVE BEEN SENT. 22/TD
&&
.PREV DISCUSSION... /ISSUED 757 AM CDT THU MAY 21 2015/
..SOUNDING DISCUSSION...
PLENTY OF MOISTURE POOLING AHEAD OF THE WEAK FRONT CURRENTLY
LOCATED OVER NORTHERN LOUISIANA AND SOUTHERN MISSISSIPPI. PW IS
ABOUT 150% OF NORMAL FOR LATE MAY. AN INVERSION FROM THE SURFACE
TO 1000 FEET IS CAPPING THE ATMOSPHERE NOW...BUT WILL MIX OUT
WITH DAYTIME HEATING. PLENTY OF INSTABILITY WITH MLCAPE AROUND
1900 J/KG WITH ML LI OF -6 AND A 500MB TEMPERATURE OF -10C. WITH
THIS INSTABILITY...GOOD MOISTURE...AND THE FRONT AND ANY SEA
BREEZE BOUNDARIES BEING LIFTING MECHANISMS...STRONG TO PERHAPS
SEVERE STORMS WILL BE POSSIBLE TODAY. MAIN CONCERN WOULD BE STRONG
WIND GUSTS WITH A LESSER CHANCE OF HAIL GIVEN HIGH FREEZING LEVEL
AROUND 13700 FEET AND WET BULB ZERO ABOUT 2000 LESS THAN THAT.
THERE IS NOT MUCH IN THE WAY OF DIRECTIONAL WIND SHEAR ON THE
CURRENT SOUNDING WITH ALL WINDS HAVE A WESTERLY COMPONENT. BUT AS
THE FRONT NEARS MAY GET A BIT MORE DIRECTIONAL SHEAR. ONE LAST
THING TO MENTION IS WE MAY SEE A FEW THUNDERSTORMS DEVELOP AHEAD
OF THE FRONT WITH A CONVECTIVE TEMPERATURE CALCULATED AT
82F. CURRENT FORECAST HAS US REACHING 82F AROUND 16-17Z AND 11Z
HRRR HAS PRECIPITATION FORMING AROUND THEN TOO.
12Z BALLOON INFO: NO ISSUES WITH THE FLIGHT THAT LASTED 94 MINUTES
AND ASCENDED TO A HEIGHT OF 20.4 MILES ABOVE THE GROUND. THE
BALLOON BURST 21 MILES DOWNRANGE FROM THE OFFICE NEAR ANSLEY.
ANSORGE
PREV DISCUSSION... /ISSUED 430 AM CDT THU MAY 21 2015/
SYNOPSIS...
LATEST SURFACE ANALYSIS SHOWED A 1011MB LOW OVER WESTERN TENNESSEE
WITH A FRONTAL BOUNDARY EXTENDING SOUTHWEST TO WEST CENTRAL
ALABAMA TO WEST CENTRAL MISSISSIPPI TO WEST CENTRAL LOUISIANA.
A 1024MB HIGH WAS LOCATED OVER NEBRASKA/KANSAS. UPPER AIR
ANALYSIS SHOWED A HIGH OVER MEXICO...DISTURBANCE RIDING ON TOP OF THE
RIDGE OVER TEXAS AND A POSITIVELY TILTED TROUGH FROM GREAT LAKES
TO IOWA. IR SHOWED CLOUD COOLING AND SEVERAL THUNDERSTORM COMPLEX
EAST OF THE BIG BEND TO NORTH CENTRAL TEXAS. RADAR REVEALED
ISOLATED CONVECTION ALONG THE FRONT OVER SOUTHERN MISSISSIPPI AND
EAST CENTRAL LOUISIANA.
DISCUSSION...
FRONTAL BOUNDARY WILL CONTINUE TO PUSH SOUTH INTO THE FORECAST
AREA TODAY. SURFACE HEATING WILL INCREASE INSTABILITY AND SURFACE
CONVERGENCE WILL YIELD SCATTERED CONVECTION TODAY. WITH THE
FRONTAL BOUNDARY PUSHING SOUTH THROUGH THE AREA TONIGHT...THE
THREAT OF CONVECTION WILL CONTINUE OVERNIGHT. UPPER LEVEL TROUGH
UP NORTH WILL SWING SOUTH ... GREAT LAKES AND MID ATLANTIC
REGIONS. SURFACE HIGH ON THE PLAINS WILL PRESS SOUTHEAST OVER THE
MID SOUTH THROUGH FRIDAY AND DRY AIR WILL FILTER IN AS EARLY AS
THIS AFTERNOON ACROSS THE NORTH ZONES.
THE FRONTAL BOUNDARY IS EXPECTED TO PUSH SOUTH INTO THE CENTRAL
GULF COAST REGION TONIGHT AND LINGERS ACROSS THE AREA ON FRIDAY
BEFORE BECOMING DIFFUSE ON SATURDAY. HIGH PRESSURE WILL SETTLE
OVER THE EAST AND SOUTHERLY FLOW DEVELOP OVER THE LOWER
MISSISSIPPI VALLEY AND FORECAST AREA SATURDAY AFTERNOON. A
BUILDING UPPER LEVEL RIDGE OVER THE CENTRAL U.S AT THE END OF WEEK
WILL TRAVERSE INTO THE EASTERN CONUS OVER THE WEEKEND. THIS UPPER
LEVEL RIDGE ALONG WITH OVERALL DRIER AIR IN THE ATMOSPHERIC COLUMN
SHOULD HAMPER MOST CONVECTION ON SATURDAY...ISOLATED FOR WEST
ZONES. RAIN CHANCES WILL START TO GO UP AGAIN ON SUNDAY AS THE
UPPER RIDGE AXIS SHIFTS TO THE EAST OF THE REGION AND DISTURBANCES
IN THE SOUTHWEST FLOW ALOFT AHEAD OF A WESTERN CONUS SYSTEM BEGIN
TO IMPACT THE REGION. THIS PATTERN WILL CONTINUE THROUGH THE EARLY
PART OF NEXT WEEK WITH DAILY CHANCES FOR SCATTERED CONVECTION.
AVIATION...
FOG SHOULD ONLY AFFECT THE HOUMA TERMINAL THIS MORNING. CEILINGS
SHOULD STAY ABOVE 015 THIS MORNING AS WELL. WILL SHOW VCTS FOR TODAY
AT ALL SITES. IT LOOKS LIKE THERE WILL BE TWO WAVES OF SH/TS...ONE
DURING THE MORNING AS THE BOUNDARY SINKS SOUTHWARD THEN AGAIN IN THE
AFTERNOON AS HEATING AND BOTH THE FRONTAL BOUNDARY AND C-BRZ
BOUNDARIES BEGIN TO ENHANCE ACTIVITY DURING THE AFTERNOON AND EARLY
EVENING. NOT EXPECTING TO SEE ANY LARGE RESTRICTIONS IN VIS
OVERNIGHT AND CEILINGS SHOULD STAY AROUND 020 FOR THE MOST PART.
MARINE...LIGHT WIND REGIME EXPECTED TO PERSIST TODAY BUT STILL
LOOKS LIKE A WEAK NOCTURNAL JET OVER THE MS SOUND AND JUST TO THE
SOUTH WILL DEVELOP THE NEXT FEW NIGHTS CAUSING WINDS TO STRENGTHEN
IN THESE AREAS TO NEAR OR JUST OVER 10 KTS. HIGH PRESSURE SLIDES
THROUGH THE AREA TODAY/FRIDAY AS A WEAK FRONT TRIES TO PUSH INTO THE
COASTAL WATERS. HIGH PRESSURE WILL QUICKLY SHIFT EAST AND MODERATE
ONSHORE FLOW WILL DEVELOP OVER THE WEEKEND.
DECISION SUPPORT...
DSS CODE...GREEN...UPGRADE TO YELLOW POSSIBLE THIS AFTERNOON.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...MONITORING STRONG TO SEVERE THUNDERSTORM POTENTIAL
TODAY.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 82 62 81 65 / 60 20 40 20
BTR 86 65 82 68 / 60 30 40 20
ASD 86 67 80 68 / 60 30 40 20
MSY 86 73 84 73 / 60 30 40 20
GPT 86 68 80 71 / 50 30 40 20
PQL 86 66 81 68 / 50 30 40 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
116 PM EDT THU MAY 21 2015
.SYNOPSIS...
HIGH PRESSURE TO THE SOUTH WILL MOVE EAST TODAY. ANOTHER COLD
FRONT WILL APPROACH FROM CUBIC LATER TONIGHT AND MOVING THROUGH
THE REGION ON FRIDAYS WITH SHOWERS FOR THE REGION. CONDITIONS
WILL REMAIN UNSETTLED INTO STUART AN UPPER LOW MOVES ACROSS THE
REGION FROM CANAD.
&&
.NEAR TERM /THROUGH TONIGHT/...
115 PM UPDATE...NO SIGNFICANT CHANGES NEEDED WITH THIS UPDATE.
TWEAKED TEMPERATURES UP A COUPLE OF DEGREES AS MANY LOCATIONS WERE
ALREADY DRAWING CLOSE TO THEIR FORECASTED HIGH. ALSO ADDED
ISOLATED SHOWERS TO THIS AFTERNOON`S FORECAST FOR THE BANGOR AREA,
AS WE`RE STARTING TO SEE DECENT CUMULUS POPPING UP AND THE HRRR
CONTINUES TO SHOW THAT SHOWERS ARE GOING TO DEVELOP. NO OTHER
CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...CLOUDS WILL INCREASE TODAY AS ANOTHER
FRONTAL BOUNDARY SLIDES TOWARDS THE REGION. AN UPPER DISTURBANCE
SEEN IN WATER VAPOR IMAGERY IS FORECAST BY THE NAM AND GFS TO
SWINGS ACROSS THE REGION. LLVL CONVERGENCE IN THE WESTERN AREAS
COMBINED W/SOME WEAK MID LEVEL FORCING COULD ALLOW FOR A FEW
SHOWERS LATER THIS AFTERNOON. DECIDED TO TAKE A CONSENSUS
APCH(NAM/GFS AND HRRR 3KM) AND BROUGHT 20-30% POPS INTO THE WNW
AREAS A BIT EARLIER THAN PREVIOUSLY FORECAST. THE REST OF THE CWA
WILL REMAIN DRY. DAYTIME TEMPERATURES ARE FORECAST TO BE IN THE
LOW/MID 60S NORTH AND WEST TO THE UPPER 60S CENTRAL AND DOWNEAST.
A WAVE OF LOW PRESSURE OVER SOUTHERN QUEBEC IS EXPECTED TO DEVELOP
ON THE FRONTAL BOUNDARY AND MOVE NE ACROSS NW MAINE. SHOWERS ARE
FORECAST TO MOVE INTO NORTHERN AND WESTERN AREAS OVERNIGHT. RAINFALL
AMOUNTS WILL BE LIGHT(<.05"). TEMPERATURES ARE EXPECTED TO BE
WARMER THAN THEY WERE THIS MORNING HOLDING IN THE 40S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
LOW PRESSURE WILL TRACK EAST OF THE GULF OF MAINE DURING FRIDAY.
STEADY RAIN ASSOCIATED WITH THIS LOW SHOULD REMAIN TO THE EAST OF
THE STATE. HOWEVER, SHOWERS ASSOCIATED WITH AN APPROACHING UPPER
LOW FROM THE NORTHWEST AND ATTENDANT COLD FRONT CAN BE EXPECTED ON
FRIDAY. THE COLD FRONT WILL MOVE EAST OF THE DOWN EAST COAST EARLY
FRIDAY EVENING WITH ANY LINGERING SHOWERS PUSHING OFFSHORE.
NORTHWEST WINDS BEHIND THE FRONT WILL USHER IN COLDER AIR FRIDAY
NIGHT. 850MB TEMPS FALL TO AROUND -5C BY 12Z SATURDAY WITH 925 MB
TEMPS DOWN TO AROUND 0C. WITH THE COLD AIR ALOFT WE COULD SEE A
FEW SNOW SHOWERS ACROSS NORTHERN AREAS AS THE 500 MB LOW TRACKS
ACROSS THE REGION. EXPECT GUSTY NORTHWEST WINDS ON SATURDAY AS LOW
PRESSURE REMAINS TO OUR NORTHEAST AND A RIDGE OF HIGH PRESSURE
BUILDS EAST. SKIES WILL BE PARTLY SUNNY ACROSS NORTHERN AND
CENTRAL AREAS WITH THE CHANCE OF A SHOWER AND PARTLY TO MOSTLY
SUNNY SKIES DOWN EAST. HIGHS ON SATURDAY WILL BE BELOW NORMAL FOR
THIS TIME OF YEAR WITH HIGHS EXPECTED TO RANGE FROM THE MID TO
UPPER 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A SHORT WAVE IS EXPECTED TO APPROACH FROM THE NORTHWEST SATURDAY
EVENING AND CROSS THE REGION LATER SATURDAY NIGHT AND INTO EARLY
SUNDAY. EXPECT PARTLY TO MOSTLY CLOUDY SKIES SATURDAY NIGHT WITH
THE CHANCE FOR A SHOWER MAINLY ACROSS NORTHERN AREAS. HIGHS ON
SUNDAY WILL RANGE FROM THE LOW TO MID 60S NORTH AND CENTRAL AND
UPPER 60S TO NEAR 70 DOWN EAST. EXPECT MAINLY CLEAR SKIES SUNDAY
NIGHT FOLLOWED BY A MAINLY SUNNY AND WARM MEMORIAL DAY. CLOUDS
WILL INCREASE MONDAY NIGHT WITH A FEW SHOWERS EXPECTED AS WARM
FRONT LIFTS NORTHEAST TOWARD THE REGION. EXPECT A CHANCE FOR
SHOWERS AND PERHAPS AN ISLD TSTM TUESDAY INTO WEDNESDAY IN ADVANCE
OF A SLOW MOVING COLD FRONT FROM THE NORTHWEST. TEMPERATURES WILL
AVERAGE ABOVE NORMAL THROUGH MID WEEK.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR CONDITIONS THROUGH TONIGHT FOR ALL TERMINALS.
SHORT TERM: VFR BUT MVFR IN ANY RAIN SHOWERS FRIDAY AND RAIN/SNOW
SHOWERS FRIDAY NIGHT. VFR CONDITIONS EXPECTED SATURDAY THROUGH
MONDAY.
&&
.MARINE...
NEAR TERM: NO HEADLINES THROUGH TONIGHT. SEAS ARE TO REMAIN 2 TO 3
FT INTO TONIGHT W/WINDS 10 TO 15 KTS.
SHORT TERM: WINDS/SEAS MAY REACH SCA LEVELS FRIDAY NIGHT AND
SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT/DUDA
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
912 AM EDT THU MAY 21 2015
.SYNOPSIS...
HIGH PRESSURE TO THE SOUTH WILL MOVE EAST TODAY. ANOTHER COLD
FRONT WILL APPROACH FROM CUBIC LATER TONIGHT AND MOVING THROUGH
THE REGION ON FRIDAYS WITH SHOWERS FOR THE REGION. CONDITIONS
WILL REMAIN UNSETTLED INTO STUART AN UPPER LOW MOVES ACROSS THE
REGION FROM CANAD.
&&
.NEAR TERM /THROUGH TONIGHT/...
910 AM UPDATE...THE FORECAST IS STILL PRETTY MUCH ON TRACK. MID
AND HIGH CLOUDS HAVE COME IN A BIT FASTER THAN PREVIOUSLY
ANTICIPATED, SO HAVE ADJUSTED ACCORDINGLY. THE LATEST HRRR
GUIDANCE CONTINUES TO INDICATE THAT THERE WILL BE ISOLATED TO
PERHAPS EVEN SCATTERED SHOWERS THIS AFTERNOON, WITH SOME ACTIVITY
MAKING IT ALL THE WAY TO BANGOR, ELLSWORTH, AND EVEN MACHIAS. MOST
OF THE OTHER MODELS ARE NOT NEARLY AS GENEROUS WITH THE PRECIP AND
KEEP IT MUCH FURTHER NORTH. BUT THE HRRR DID VERY WELL WITH THE
SHOWERS THAT DEVELOPED YESTERDAY, SO WENT AHEAD AND ADDED ISOLATED
AFTERNOON SHOWERS FOR EVERYWHERE BASICALLY NORTH OF BANGOR. NO
OTHER CHANGES WERE NEEDED AT THIS TIME.
PREVIOUS DISCUSSION...CLOUDS WILL INCREASE TODAY AS ANOTHER
FRONTAL BOUNDARY SLIDES TOWARDS THE REGION. AN UPPER DISTURBANCE
SEEN IN WATER VAPOR IMAGERY IS FORECAST BY THE NAM AND GFS TO
SWINGS ACROSS THE REGION. LLVL CONVERGENCE IN THE WESTERN AREAS
COMBINED W/SOME WEAK MID LEVEL FORCING COULD ALLOW FOR A FEW
SHOWERS LATER THIS AFTERNOON. DECIDED TO TAKE A CONSENSUS
APCH(NAM/GFS AND HRRR 3KM) AND BROUGHT 20-30% POPS INTO THE WNW
AREAS A BIT EARLIER THAN PREVIOUSLY FORECAST. THE REST OF THE CWA
WILL REMAIN DRY. DAYTIME TEMPERATURES ARE FORECAST TO BE IN THE
LOW/MID 60S NORTH AND WEST TO THE UPPER 60S CENTRAL AND DOWNEAST.
A WAVE OF LOW PRESSURE OVER SOUTHERN QUEBEC IS EXPECTED TO DEVELOP
ON THE FRONTAL BOUNDARY AND MOVE NE ACROSS NW MAINE. SHOWERS ARE
FORECAST TO MOVE INTO NORTHERN AND WESTERN AREAS OVERNIGHT. RAINFALL
AMOUNTS WILL BE LIGHT(<.05"). TEMPERATURES ARE EXPECTED TO BE
WARMER THAN THEY WERE THIS MORNING HOLDING IN THE 40S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
LOW PRESSURE WILL TRACK EAST OF THE GULF OF MAINE DURING FRIDAY.
STEADY RAIN ASSOCIATED WITH THIS LOW SHOULD REMAIN TO THE EAST OF
THE STATE. HOWEVER, SHOWERS ASSOCIATED WITH AN APPROACHING UPPER
LOW FROM THE NORTHWEST AND ATTENDANT COLD FRONT CAN BE EXPECTED ON
FRIDAY. THE COLD FRONT WILL MOVE EAST OF THE DOWN EAST COAST EARLY
FRIDAY EVENING WITH ANY LINGERING SHOWERS PUSHING OFFSHORE.
NORTHWEST WINDS BEHIND THE FRONT WILL USHER IN COLDER AIR FRIDAY
NIGHT. 850MB TEMPS FALL TO AROUND -5C BY 12Z SATURDAY WITH 925 MB
TEMPS DOWN TO AROUND 0C. WITH THE COLD AIR ALOFT WE COULD SEE A
FEW SNOW SHOWERS ACROSS NORTHERN AREAS AS THE 500 MB LOW TRACKS
ACROSS THE REGION. EXPECT GUSTY NORTHWEST WINDS ON SATURDAY AS LOW
PRESSURE REMAINS TO OUR NORTHEAST AND A RIDGE OF HIGH PRESSURE
BUILDS EAST. SKIES WILL BE PARTLY SUNNY ACROSS NORTHERN AND
CENTRAL AREAS WITH THE CHANCE OF A SHOWER AND PARTLY TO MOSTLY
SUNNY SKIES DOWN EAST. HIGHS ON SATURDAY WILL BE BELOW NORMAL FOR
THIS TIME OF YEAR WITH HIGHS EXPECTED TO RANGE FROM THE MID TO
UPPER 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A SHORT WAVE IS EXPECTED TO APPROACH FROM THE NORTHWEST SATURDAY
EVENING AND CROSS THE REGION LATER SATURDAY NIGHT AND INTO EARLY
SUNDAY. EXPECT PARTLY TO MOSTLY CLOUDY SKIES SATURDAY NIGHT WITH
THE CHANCE FOR A SHOWER MAINLY ACROSS NORTHERN AREAS. HIGHS ON
SUNDAY WILL RANGE FROM THE LOW TO MID 60S NORTH AND CENTRAL AND
UPPER 60S TO NEAR 70 DOWN EAST. EXPECT MAINLY CLEAR SKIES SUNDAY
NIGHT FOLLOWED BY A MAINLY SUNNY AND WARM MEMORIAL DAY. CLOUDS
WILL INCREASE MONDAY NIGHT WITH A FEW SHOWERS EXPECTED AS WARM
FRONT LIFTS NORTHEAST TOWARD THE REGION. EXPECT A CHANCE FOR
SHOWERS AND PERHAPS AN ISLD TSTM TUESDAY INTO WEDNESDAY IN ADVANCE
OF A SLOW MOVING COLD FRONT FROM THE NORTHWEST. TEMPERATURES WILL
AVERAGE ABOVE NORMAL THROUGH MID WEEK.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR CONDITIONS THROUGH TONIGHT FOR ALL TERMINALS.
SHORT TERM: VFR BUT MVFR IN ANY RAIN SHOWERS FRIDAY AND RAIN/SNOW
SHOWERS FRIDAY NIGHT. VFR CONDITIONS EXPECTED SATURDAY THROUGH
MONDAY.
&&
.MARINE...
NEAR TERM: NO HEADLINES THROUGH TONIGHT. SEAS ARE TO REMAIN 2 TO 3
FT INTO TONIGHT W/WINDS 10 TO 15 KTS.
SHORT TERM: WINDS/SEAS MAY REACH SCA LEVELS FRIDAY NIGHT AND
SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT/DUDA
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
704 AM EDT THU MAY 21 2015
.SYNOPSIS...
HIGH PRESSURE TO THE SOUTH WILL MOVE EAST TODAY. ANOTHER COLD
FRONT WILL APPROACH FROM CUBIC LATER TONIGHT AND MOVING THROUGH
THE REGION ON FRIDAYS WITH SHOWERS FOR THE REGION. CONDITIONS
WILL REMAIN UNSETTLED INTO STUART AN UPPER LOW MOVES ACROSS THE
REGION FROM CANAD.
&&
.NEAR TERM /THROUGH TONIGHT/...
7 AM UPDATE: 09Z SATE IMAGERY SHOWED MID/HIGH CLOUDS MOVING ENE
IN ASSOCIATION W/AN UPPER DISTURBANCE MOVING ACROSS NORTHERN NY AND
NORTHERN NEW ENGLAND. MOST OF THE METERS SHOWED THE HIGH CLOUDS TO
BE THIN. SUNSHINE WILL ALLOW FOR TEMPERATURES TO WARM AFTER A CHILLY
START. WINDS WILL PICK UP BY MID MORNING BACKING TO SW BY THE AFTERNOON.
PREVIOUS DISCUSSION...
CLOUDS WILL INCREASE TODAY AS ANOTHER FRONTAL BOUNDARY SLIDES
TOWARDS THE REGION. AN UPPER DISTURBANCE SEEN IN WATER VAPOR
IMAGERY IS FORECAST BY THE NAM AND GFS TO SWINGS ACROSS THE
REGION. LLVL CONVERGENCE IN THE WESTERN AREAS COMBINED W/SOME WEAK
MID LEVEL FORCING COULD ALLOW FOR A FEW SHOWERS LATER THIS
AFTERNOON. DECIDED TO TAKE A CONSENSUS APCH(NAM/GFS AND HRRR 3KM)
AND BROUGHT 20-30% POPS INTO THE WNW AREAS A BIT EARLIER THAN
PREVIOUSLY FORECAST. THE REST OF THE CWA WILL REMAIN DRY. DAYTIME
TEMPERATURES ARE FORECAST TO BE IN THE LOW/MID 60S NORTH AND WEST
TO THE UPPER 60S CENTRAL AND DOWNEAST.
A WAVE OF LOW PRESSURE OVER SOUTHERN QUEBEC IS EXPECTED TO DEVELOP
ON THE FRONTAL BOUNDARY AND MOVE NE ACROSS NW MAINE. SHOWERS ARE
FORECAST TO MOVE INTO NORTHERN AND WESTERN AREAS OVERNIGHT. RAINFALL
AMOUNTS WILL BE LIGHT(<.05"). TEMPERATURES ARE EXPECTED TO BE
WARMER THAN THEY WERE THIS MORNING HOLDING IN THE 40S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
LOW PRESSURE WILL TRACK EAST OF THE GULF OF MAINE DURING FRIDAY.
STEADY RAIN ASSOCIATED WITH THIS LOW SHOULD REMAIN TO THE EAST OF
THE STATE. HOWEVER, SHOWERS ASSOCIATED WITH AN APPROACHING UPPER
LOW FROM THE NORTHWEST AND ATTENDANT COLD FRONT CAN BE EXPECTED ON
FRIDAY. THE COLD FRONT WILL MOVE EAST OF THE DOWN EAST COAST EARLY
FRIDAY EVENING WITH ANY LINGERING SHOWERS PUSHING OFFSHORE.
NORTHWEST WINDS BEHIND THE FRONT WILL USHER IN COLDER AIR FRIDAY
NIGHT. 850MB TEMPS FALL TO AROUND -5C BY 12Z SATURDAY WITH 925 MB
TEMPS DOWN TO AROUND 0C. WITH THE COLD AIR ALOFT WE COULD SEE A
FEW SNOW SHOWERS ACROSS NORTHERN AREAS AS THE 500 MB LOW TRACKS
ACROSS THE REGION. EXPECT GUSTY NORTHWEST WINDS ON SATURDAY AS LOW
PRESSURE REMAINS TO OUR NORTHEAST AND A RIDGE OF HIGH PRESSURE
BUILDS EAST. SKIES WILL BE PARTLY SUNNY ACROSS NORTHERN AND
CENTRAL AREAS WITH THE CHANCE OF A SHOWER AND PARTLY TO MOSTLY
SUNNY SKIES DOWN EAST. HIGHS ON SATURDAY WILL BE BELOW NORMAL FOR
THIS TIME OF YEAR WITH HIGHS EXPECTED TO RANGE FROM THE MID TO
UPPER 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A SHORT WAVE IS EXPECTED TO APPROACH FROM THE NORTHWEST SATURDAY
EVENING AND CROSS THE REGION LATER SATURDAY NIGHT AND INTO EARLY
SUNDAY. EXPECT PARTLY TO MOSTLY CLOUDY SKIES SATURDAY NIGHT WITH
THE CHANCE FOR A SHOWER MAINLY ACROSS NORTHERN AREAS. HIGHS ON
SUNDAY WILL RANGE FROM THE LOW TO MID 60S NORTH AND CENTRAL AND
UPPER 60S TO NEAR 70 DOWN EAST. EXPECT MAINLY CLEAR SKIES SUNDAY
NIGHT FOLLOWED BY A MAINLY SUNNY AND WARM MEMORIAL DAY. CLOUDS
WILL INCREASE MONDAY NIGHT WITH A FEW SHOWERS EXPECTED AS WARM
FRONT LIFTS NORTHEAST TOWARD THE REGION. EXPECT A CHANCE FOR
SHOWERS AND PERHAPS AN ISLD TSTM TUESDAY INTO WEDNESDAY IN ADVANCE
OF A SLOW MOVING COLD FRONT FROM THE NORTHWEST. TEMPERATURES WILL
AVERAGE ABOVE NORMAL THROUGH MID WEEK.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR CONDITIONS THROUGH TONIGHT FOR ALL TERMINALS.
SHORT TERM: VFR BUT MVFR IN ANY RAIN SHOWERS FRIDAY AND RAIN/SNOW
SHOWERS FRIDAY NIGHT. VFR CONDITIONS EXPECTED SATURDAY THROUGH
MONDAY.
&&
.MARINE...
NEAR TERM: NO HEADLINES THROUGH TONIGHT. SEAS ARE TO REMAIN 2 TO 3
FT INTO TONIGHT W/WINDS 10 TO 15 KTS.
SHORT TERM: WINDS/SEAS MAY REACH SCA LEVELS FRIDAY NIGHT AND
SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT/DUDA
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
352 AM EDT THU MAY 21 2015
.SYNOPSIS...
HIGH PRESSURE TO THE SOUTH WILL MOVE EAST TODAY. ANOTHER COLD
FRONT WILL APPROACH FROM QUEBEC LATER TONIGHT AND MOVING
THROUGH THE REGION ON FRIDAY WITH SHOWERS FOR THE REGION.
CONDITIONS WILL REMAIN UNSETTLED INTO SATURDAY AN UPPER LOW MOVES
ACROSS THE REGION FROM CANADA.
&&
.NEAR TERM /THROUGH TONIGHT/...
ANOTHER COLD FRONT EXPECTED TO AFFECT THE REGION.
06Z SURFACE ANALYSIS SHOWED HIGH PRES OVER NYS SLIDING E. SKIES
WERE GENERALLY CLEAR PER THE LATEST IR SATL IMAGERY W/SOME CLOUDS
SKIRTING NORTHERN AREAS AND ANOTHER BATCH MOVING INTO WESTERN AND
SW AREAS. TEMPERATURES VARYING QUITE A BIT, MEANING LOW LYING
REGIONS HAVE DROPPED BACK INTO THE MID AND UPPER 20S AS WINDS HAVE
DROPPED OFF. ELSEWHERE, TEMPERATURES WERE AVERAGING IN THE 40S
W/WINDS AOA 6 MPH. TEMPERATURES ARE EXPECTED TO DROP OFF BY
SUNRISE W/THE COOL AIR IN PLACE. THOSE CLOUDS ACROSS THE WEST AND
SW WILL INCREASE TODAY AS ANOTHER FRONTAL BOUNDARY SLIDES TOWARDS
THE REGION. AN UPPER DISTURBANCE SEEN IN WATER VAPOR IMAGERY IS
FORECAST BY THE NAM AND GFS TO SWINGS ACROSS THE REGION. LLVL
CONVERGENCE IN THE WESTERN AREAS COMBINED W/SOME WEAK MID LEVEL
FORCING COULD ALLOW FOR A FEW SHOWERS LATER THIS AFTERNOON.
DECIDED TO TAKE A CONSENSUS APCH(NAM/GFS AND HRRR 3KM) AND BROUGHT
20-30% POPS INTO THE WNW AREAS A BIT EARLIER THAN PREVIOUSLY
FORECAST. THE REST OF THE CWA WILL REMAIN DRY. DAYTIME
TEMPERATURES ARE FORECAST TO BE IN THE LOW/MID 60S NORTH AND WEST
TO THE UPPER 60S CENTRAL AND DOWNEAST.
A WAVE OF LOW PRESSURE OVER SOUTHERN QUEBEC IS EXPECTED TO DEVELOP
ON THE FRONTAL BOUNDARY AND MOVE NE ACROSS NW MAINE. SHOWERS ARE
FORECAST TO MOVE INTO NORTHERN AND WESTERN AREAS OVERNIGHT. RAINFALL
AMOUNTS WILL BE LIGHT(<.05"). TEMPERATURES ARE EXPECTED TO BE
WARMER THAN THEY WERE THIS MORNING HOLDING IN THE 40S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
LOW PRESSURE WILL TRACK EAST OF THE GULF OF MAINE DURING FRIDAY.
STEADY RAIN ASSOCIATED WITH THIS LOW SHOULD REMAIN TO THE EAST OF
THE STATE. HOWEVER, SHOWERS ASSOCIATED WITH AN APPROACHING UPPER
LOW FROM THE NORTHWEST AND ATTENDANT COLD FRONT CAN BE EXPECTED ON
FRIDAY. THE COLD FRONT WILL MOVE EAST OF THE DOWN EAST COAST EARLY
FRIDAY EVENING WITH ANY LINGERING SHOWERS PUSHING OFFSHORE.
NORTHWEST WINDS BEHIND THE FRONT WILL USHER IN COLDER AIR FRIDAY
NIGHT. 850MB TEMPS FALL TO AROUND -5C BY 12Z SATURDAY WITH 925 MB
TEMPS DOWN TO AROUND 0C. WITH THE COLD AIR ALOFT WE COULD SEE A
FEW SNOW SHOWERS ACROSS NORTHERN AREAS AS THE 500 MB LOW TRACKS
ACROSS THE REGION. EXPECT GUSTY NORTHWEST WINDS ON SATURDAY AS LOW
PRESSURE REMAINS TO OUR NORTHEAST AND A RIDGE OF HIGH PRESSURE
BUILDS EAST. SKIES WILL BE PARTLY SUNNY ACROSS NORTHERN AND
CENTRAL AREAS WITH THE CHANCE OF A SHOWER AND PARTLY TO MOSTLY
SUNNY SKIES DOWN EAST. HIGHS ON SATURDAY WILL BE BELOW NORMAL FOR
THIS TIME OF YEAR WITH HIGHS EXPECTED TO RANGE FROM THE MID TO
UPPER 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A SHORT WAVE IS EXPECTED TO APPROACH FROM THE NORTHWEST SATURDAY
EVENING AND CROSS THE REGION LATER SATURDAY NIGHT AND INTO EARLY
SUNDAY. EXPECT PARTLY TO MOSTLY CLOUDY SKIES SATURDAY NIGHT WITH
THE CHANCE FOR A SHOWER MAINLY ACROSS NORTHERN AREAS. HIGHS ON
SUNDAY WILL RANGE FROM THE LOW TO MID 60S NORTH AND CENTRAL AND
UPPER 60S TO NEAR 70 DOWN EAST. EXPECT MAINLY CLEAR SKIES SUNDAY
NIGHT FOLLOWED BY A MAINLY SUNNY AND WARM MEMORIAL DAY. CLOUDS
WILL INCREASE MONDAY NIGHT WITH A FEW SHOWERS EXPECTED AS WARM
FRONT LIFTS NORTHEAST TOWARD THE REGION. EXPECT A CHANCE FOR
SHOWERS AND PERHAPS AN ISLD TSTM TUESDAY INTO WEDNESDAY IN ADVANCE
OF A SLOW MOVING COLD FRONT FROM THE NORTHWEST. TEMPERATURES WILL
AVERAGE ABOVE NORMAL THROUGH MID WEEK.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR CONDITIONS THROUGH TONIGHT FOR ALL TERMINALS.
SHORT TERM: VFR BUT MVFR IN ANY RAIN SHOWERS FRIDAY AND RAIN/SNOW
SHOWERS FRIDAY NIGHT. VFR CONDITIONS EXPECTED SATURDAY THROUGH
MONDAY.
&&
.MARINE...
NEAR TERM: NO HEADLINES THROUGH TONIGHT. SEAS ARE TO REMAIN 2 TO 3
FT INTO TONIGHT W/WINDS 10 TO 15 KTS.
SHORT TERM: WINDS/SEAS MAY REACH SCA LEVELS FRIDAY NIGHT AND
SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT/DUDA
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
329 PM EDT THU MAY 21 2015
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE
.SYNOPSIS...
ISSUED AT 329 PM EDT THU MAY 21 2015
SCATTERED RAIN SHOWERS WILL MOVE SOUTH THROUGH THE AREA WITH A COLD
FRONT. BEHIND THIS FRONT...HIGH TEMPERATURES FRIDAY WILL BE AROUND
60...WHICH IS ABOUT 10 DEGREES BELOW NORMAL THIS TIME OF YEAR.
PATCHY FROST IS POSSIBLE OVER PARTS OF CENTRAL LOWER MICHIGAN FRIDAY
MORNING. THERE IS EVEN BETTER POTENTIAL FOR FROST SATURDAY MORNING.
RAIN CHANCES RETURN SUNDAY AFTERNOON WITH A WARMER AND WETTER
PATTERN LASTING WELL INTO NEXT WEEK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 329 PM EDT THU MAY 21 2015
SCATTERED SHOWERS ARE POSSIBLE THIS EVENING. COOLER THAN NORMAL
TEMPERATURES WILL PERSIST THROUGH FRIDAY NIGHT. FROST FORMATION IS
POSSIBLE TONIGHT MAINLY ACROSS CENTRAL LOWER MICHIGAN. WIDESPREAD
AREAS OF FROST ARE MORE LIKELY LATE FRIDAY NIGHT INTO SATURDAY
MORNING.
A WEAK COLD FRONT WILL DROP SOUTH THROUGH LOWER MICHIGAN THIS
EVENING AS AN UPPER LEVEL SHORTWAVE PROPAGATES OVER THE LOWER GREAT
LAKES REGION. MOISTURE IS CONFINED TO THE MID LEVELS WITH CLOUD
BASES AROUND 9K FEET. SFC DEWPOINTS ARE ONLY IN THE 30S TO LOWER
40S. ALL THIS SHOULD RESULT IN ISOLATED TO SCATTERED LIGHT RAIN
SHOWERS...CONFIRMED BY THE LAST SEVERAL RUNS OF THE RAP AND HRRR. A
SIMILAR AIRMASS YESTERDAY EVENING RESULTED IN A RAIN/SLEET MIX
MAINLY IN THE CHICAGO AREA. BUT PRECIP THIS EVENING WILL LIKELY NOT
BE HEAVY ENOUGH TO CAUSE SIGNIFICANT WET-BULBING.
MID-LEVEL CLOUDS WILL START TO CLEAR OUT FROM NORTH TO SOUTH LATE
TONIGHT AND WINDS WILL SUBSIDE AS THEY VEER NORTHERLY BEHIND THE SFC
FRONT. THIS SHOULD ALLOW DECENT RADIATIONAL COOLING CONDITIONS TO
SET UP AFTER MIDNIGHT. FROST WILL BE POSSIBLE ACROSS CENTRAL LOWER
MICHIGAN.
ANOTHER COOL DAY IS EXPECTED ON FRIDAY WITH NORTHWEST FLOW AT THE
SURFACE. BUT PLENTY OF SUNSHINE IS EXPECTED AS A SURFACE HIGH BUILDS
IN. UPPER RIDGING WILL CONTINUE TO BUILD IN THROUGH SATURDAY NIGHT
AS THE SFC HIGH SLIDES OFF TO THE SOUTHEAST. FAIR WEATHER IS
EXPECTED FRIDAY NIGHT THROUGH SATURDAY NIGHT...BUT THIS SHOULD ALLOW
GOOD FROST CONDITIONS TO SET UP FRIDAY NIGHT INTO SATURDAY MORNING.
WITH CLEAR SKIES AND LIGHT WINDS...LOWS WILL LIKELY DROP INTO THE
LOW TO MID 30S ACROSS MUCH OF THE FORECAST AREA. SOUTHWEST RETURN
FLOW FINALLY SETS UP SATURDAY...ALONG WITH PLENTY OF SUNSHINE AND
HIGHS IN THE LOWER 70S.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 329 PM EDT THU MAY 21 2015
THE MAIN STORY IN THE LONG TERM PERIOD IS THAT WE WILL FINALLY SEE
WARMER TEMPERATURES AS THE PERSISTENT HUDSON BAY UPPER LOW RETREATS
AND WE GET INTO DEEP SOUTHWEST FLOW. HIGHS IN THE 70S ARE LIKELY
AWAY FROM LK MI... WITH PERHAPS 80 DEGREES AND NOTICEABLY MORE HUMID
FROM MONDAY ON.
PROLONGED WARM ADVECTION PATTERN WITH A FLOW OFF THE GULF AND A
QUASI STATIONARY FRONTAL BOUNDARY WILL LIKELY LEAD TO ROUNDS OF
SHOWERS AND POSSIBLE TSTMS. HOWEVER THE TIMING/LOCATION/DURATION OF
CONVECTIVE EPISODES AND DAILY POSITION OF THE SFC FRONT IS LOW
CONFIDENCE AT THIS TIME. CURRENTLY WE HAVE THE HIGHEST POPS ON
SUNDAY NIGHT AND MONDAY WHICH IS WHEN THE SFC WARM FRONT IS LIFTING
NORTH THROUGH THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 153 PM EDT THU MAY 21 2015
VFR WEATHER WILL CONTINUE THE NEXT 24 HOURS. THE AREA OF CLOUDS
CURRENTLY OVERHEAD WITH BASES AT OR ABOVE 12,000 FT WILL MOVE OUT
THIS AFTERNOON... AND WILL BE FOLLOWED BY A NARROW BAND OF CLOUDS
DROPPING DOWN FROM THE NORTH THIS EVENING. THESE CLOUDS WILL HAVE
BASES BETWEEN 6000 AND 10,000 FT AND MAY PRODUCE A FEW LIGHT
RAIN SHOWERS OR SPRINKLES BUT NO REDUCTIONS TO VSBYS. CLEAR SKIES
WILL FOLLOW BEHIND THIS BAND OF CLOUDS FOR LATER NIGHT AND FRIDAY
MORNING. A PERIOD OF GUSTY WEST WINDS IS EXPECTED THROUGH 00Z
BEFORE DIMINISHING AND TURNING NORTHERLY LATER TONIGHT.
&&
.MARINE...
ISSUED AT 329 PM EDT THU MAY 21 2015
BREEZY WESTERLY WINDS WILL CONTINUE THIS AFTERNOON WITH WAVES IN
THE 1 TO 3 FOOT RANGE. SCATTERED LIGHT SHOWERS WILL BE POSSIBLE
LATE THIS AFTERNOON AND EVENING. WINDS ARE EXPECTED TO SUBSIDE
AND VEER NORTHERLY BEHIND A WEAK COLD FRONT OVERNIGHT. WAVES WILL
BE 1 TO 2 FEET. NORTHERLY WINDS OF 5 TO 10 KNOTS ON FRIDAY WITH
WAVES AROUND 1 FOOT. FRIDAY WILL FEATURE PLENTY OF SUNSHINE BUT
STILL COOLER THAN NORMAL TEMPS. WINDS WILL TURN SOUTHWESTERLY ON
SATURDAY IN THE 5 TO 15 KNOT RANGE WITH WAVES AROUND 1 FOOT.
&&
.HYDROLOGY...
ISSUED AT 1240 PM EDT THU MAY 21 2015
NO CONCERNS THROUGH THE WEEKEND. PRECIPITATION THAT COULD AFFECT
MAINSTEM RIVERS IS NOT EXPECTED UNTIL LATE SUNDAY...WHICH MARKS THE
START OF A WETTER PATTERN LASTING WELL INTO THE COMING WORK WEEK.
NATIONAL GUIDANCE ADVERTISES UNIFORM RAINFALL TOTALS OF 1-1.5
INCHES ACROSS THE AREA THROUGH THURSDAY MORNING. GIVEN THAT BASE
FLOWS ARE NEAR OR BELOW NORMAL AND THAT RAIN SHOULD BE SPREAD OUT
OVER TIME...WE EXPECT FAIRLY GENTLE RISES WILL BE UNDERWAY BY THE
MIDDLE OF NEXT WEEK.
THAT SAID...FORECASTING CONVECTIVE RAINFALL THIS FAR OUT IS
HIGHLY UNCERTAIN SO THERE STILL REMAINS A FAIRLY WIDE RANGE OF
POSSIBILITIES FOR RAINFALL AND RIVER RESPONSES AT THIS POINT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY FROM 3 AM TO 9 AM EDT FRIDAY FOR MIZ037>040-
043>046.
LM...NONE.
&&
$$
SYNOPSIS...TJT
SHORT TERM...EBW
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...TJT
MARINE...EBW
AREA FORECAST DISCUSSION
NWS DULUTH MN
331 AM CDT THU MAY 21 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM CDT THU MAY 21 2015
QUIET SHORT TERM FORECAST WITH UPPER LEVEL RIDGING BUILDING INTO
THE DAKOTAS...COMPLIMENTED BY BROAD SFC HIGH PRESSURE THROUGH THE
REMAINDER OF THE WEEK.
WINDS WILL BE OUT OF THE NORTH TODAY WITH AFTERNOON GUSTS IN THE
15 TO 20 KT RANGE AS HUDSON BAY LOW DEPARTS TO THE EAST. SKIES
WILL BECOME MOSTLY SUNNY WITH AFTERNOON TEMPERATURES IN THE 60S
TO LOW 70S. CONDITIONS WILL BE COOLER ALONG THE SHORES OF LAKE
SUPERIOR. THE RELATIVELY COOL AIR ALOFT WITH H85 TEMPS IN THE
SINGLE DIGITS WILL RESULT IN DEEP AFTERNOON MIXING TO AROUND 6000
FT...PROMOTING FALLING DEW POINTS/RH VALUES. HAVE LOWERED THE
MINIMUM RELATIVE HUMIDITY TODAY INTO THE 25 TO 30% RANGE ACROSS
THE FORECAST AREA.
FRIDAY WILL AGAIN BE SUNNY AND DRY WITH TEMPERATURES IN THE 60S TO
LOW 70S. WINDS WILL BE LIGHT...BECOMING SOUTHWEST 5 TO 10 MPH IN
THE AFTERNOON INLAND FROM LAKE SUPERIOR.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 312 AM CDT THU MAY 21 2015
A GENERALLY WET PATTERN DEVELOPING OVER THE WEEKEND AND INTO EARLY
NEXT WEEK WITH TEMPERATURES NEAR TO SLIGHTLY WARMER THAN NORMAL.
LARGE DIFFERENCES BETWEEN MODELS AND RUN-TO-RUN LEAD TO SLIGHTLY
LOWER THAN USUAL CONFIDENCE IN THE FORECAST....BUT AM FAIRLY
CONFIDENT IN A WIDESPREAD HALF INCH TO AN INCH OF RAINFALL ACROSS
MUCH OF THE REGION...WITH THE EXCEPTION OF FAR NORTHEAST MINNESOTA
FROM THE IRON EAST ACROSS THE ARROWHEAD REGION WHICH MAY MISS OUT ON
SOME OF THE HIGHER PRECIP AMOUNTS.
ON THE SYNOPTIC SCALE A LONGWAVE TROUGH WILL DEEPEN ACROSS THE
DESERT SOUTHWEST WITH A WEAK RIDGE AXIS OVER THE SOUTHEAST EXTENDING
UP THROUGH THE UPPER MIDWEST...WITH A BROAD AREA OF HIGH PRESSURE
OVER THE MID ATLANTIC STATES. THIS WILL RESULT IN SOUTHERN FLOW AT
LOW LEVELS ACROSS THE CENTRAL PLAINS INTO THE MISSISSIPPI RIVER
VALLEY...RESULTING IN RICH GULF MOISTURE BEING ADVECTED INTO THE
NORTHLAND. LARGE SCALE FORCING FROM MID-LEVEL DISTURBANCES WILL
RESULT IN SHOWERS AND A FEW THUNDERSTORMS LATE SATURDAY BUT MORE SO
SUNDAY INTO MONDAY.
IN GENERAL THERMODYNAMIC PROFILES DO NOT SUPPORT THUNDERSTORMS DUE
TO MID-LEVEL LAPSE RATES...BUT A FEW EMBEDDED STORMS WILL BE
POSSIBLE LATE IN THE WEEKEND INTO EARLY NEXT WEEK. THE POTENTIAL FOR
SEVERE THUNDERSTORMS IS VERY LOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 105 AM CDT THU MAY 21 2015
VFR CONDITIONS EXPECTED AT ALL TERMINALS THROUGH THE FORECAST
PERIOD...EXCEPT FOR KHYR AND KBRD. BETWEEN 07Z AND 10Z THE LATEST
GUIDANCE SHOWS DEW POINT DEPRESSIONS BETWEEN 4 TO 6 DEGREES F
ALONG WITH LIGHT WINDS AT KBRD AND KHYR. DURING THIS TIME FRAME
MVFR VIS IS POSSIBLE AS FOG MAY DEVELOP.
A COLD FRONT IS CURRENTLY LOCATED ALONG THE INTERNATIONAL BORDER.
THE FRONT WILL MOVE FROM NORTH TO SOUTH FOR THE REST OF TONIGHT
AND ON THURSDAY. THIS WILL SHIFT WINDS FROM A WESTERLY DIRECTION
TO A NORTHERLY DIRECTION BETWEEN 14Z AND 18Z AT ALL TERMINALS.
HOWEVER THE LAST FEW RAP RUNS AND LATEST NAM/GFS SHOW WINDS AT
KDLH SHIFT TO A NORTHEASTERLY DIRECTION AROUND 14Z BEFORE
BECOMING NORTHERLY AT 18Z. GUSTY WINDS WILL DEVELOP IN WAKE OF THE
COLD FRONT PASSAGE ONCE WINDS BECOME NORTHERLY. AFTER 01Z EXPECT
WINDS TO DECOUPLE AS THE NIGHT TIME INVERSION SETS UP.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 65 36 65 47 / 0 0 0 0
INL 64 35 70 48 / 0 0 0 0
BRD 67 40 70 48 / 0 0 0 0
HYR 67 35 69 45 / 0 0 0 0
ASX 63 32 65 46 / 0 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GRANING
LONG TERM...JJM
AVIATION...WL
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
106 AM CDT THU MAY 21 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 349 PM CDT WED MAY 20 2015
AN UPPER LEVEL WAVE WAS MOVING THROUGH THE UPPER MISSISSIPPI RIVER
VALLEY AT 18Z. MEANWHILE...A WEAK COLD FRONT WAS DROPPING SOUTH FROM
CANADA TOWARD THE MN BORDER. CLOUDS HAD DRIFTED INTO THE REGION THIS
AFTERNOON AS A RESULT OF THIS WAVE. THE FRONT WILL MOVE THROUGH NE
MN BY 12Z THURSDAY AND THROUGH NW WI BY 18Z. NO RAIN IS EXPECTED
WITH THIS FRONTAL PASSAGE...JUST A FEW CLOUDS AND A WIND SHIFT TO
THE NORTH OR NORTHWEST. SOME BRIEF GUSTY WINDS OUT OF THE NW MAY
OCCUR WITH FROPA...BUT WILL QUICKLY SUBSIDE. OTHERWISE...HIGH
PRESSURE WILL BUILD OVER THE AREA ON THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 PM CDT WED MAY 20 2015
THE FIRST PART OF THE LONG TERM PERIOD LOOKS TO BE FAIRLY QUIET...
WITH BROAD SFC HIGH PRESSURE CENTERED ACROSS THE OHIO RIVER VALLEY
FRIDAY... AND A MID-LAYERED TROUGH LOCATED ACROSS NEW ENGLAND...
CREATING A RIDGE ACROSS THE NORTHERN PLAINS. WITH LIGHT SOUTHERLY
WINDS ACROSS THE NORTHLAND AND LOW LEVEL EASTERLY FLOW OFF THE
LAKE...HIGH RES MODULES ARE INDICATING A POSSIBLE LAKE BREEZE
FORMING FRIDAY AFTERNOON ALONG THE NORTH SHORE. OTHERWISE... THE
MAIN FOCUS FOR THE LONG TERM PERIOD WILL BE A COLORADO LOW
APPROACHING THE NORTHLAND THIS WEEKEND. THERE REMAINS A SIGNIFICANT
DIFFERENCE BETWEEN THE ECMWF AND THE GFS/NAM/GEM REGARDING THE
IMPACTS OF THE LOW... WITH ECMWF COMING IN MOSTLY DRY SATURDAY
AFTERNOON... GFS COMING IN WITH NEARLY 0.5 INCHES OF RAIN IN CENTRAL
MINNESOTA... AND THE OTHER MODELS A BIT LESS. DECIDED TO LEAN AWAY
FROM THE ECMWF AND MORE TOWARDS THE WET SIDE AS IT APPEARS TO BE AN
OUTLIER. EXPECTING THE WARM FRONT TO MOVE NORTHWARD AND STALL ACROSS
OUR SOUTHERN CWA...JUST SOUTH OF DULUTH... SATURDAY EVENING AND
SUNDAY... WHERE THERE COULD BE ENOUGH MU CAPE TO PRODUCE THUNDERSTORM
ACTIVITY. FARTHER SOUTH OF THE STALLED FRONT WILL LIKELY SEE
SCATTERED SHOWERS. THE WET PATTERN... WITH OCCASIONAL CHANCES OF
THUNDERSTORMS...WILL CONTINUE INTO EARLY NEXT WEEK AS MOISTURE
INCREASES OUT OF THE SOUTH. WHILE IT IS STILL FAR OUT... THE GFS IS
INDICATING ENHANCED INSTABILITY AROUND WEDNESDAY OF NEXT WEEK FOR
STRONG THUNDERSTORMS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 105 AM CDT THU MAY 21 2015
VFR CONDITIONS EXPECTED AT ALL TERMINALS THROUGH THE FORECAST
PERIOD...EXCEPT FOR KHYR AND KBRD. BETWEEN 07Z AND 10Z THE LATEST
GUIDANCE SHOWS DEW POINT DEPRESSIONS BETWEEN 4 TO 6 DEGREES F
ALONG WITH LIGHT WINDS AT KBRD AND KHYR. DURING THIS TIME FRAME
MVFR VIS IS POSSIBLE AS FOG MAY DEVELOP.
A COLD FRONT IS CURRENTLY LOCATED ALONG THE INTERNATIONAL BORDER.
THE FRONT WILL MOVE FROM NORTH TO SOUTH FOR THE REST OF TONIGHT
AND ON THURSDAY. THIS WILL SHIFT WINDS FROM A WESTERLY DIRECTION
TO A NORTHERLY DIRECTION BETWEEN 14Z AND 18Z AT ALL TERMINALS.
HOWEVER THE LAST FEW RAP RUNS AND LATEST NAM/GFS SHOW WINDS AT
KDLH SHIFT TO A NORTHEASTERLY DIRECTION AROUND 14Z BEFORE
BECOMING NORTHERLY AT 18Z. GUSTY WINDS WILL DEVELOP IN WAKE OF THE
COLD FRONT PASSAGE ONCE WINDS BECOME NORTHERLY. AFTER 01Z EXPECT
WINDS TO DECOUPLE AS THE NIGHT TIME INVERSION SETS UP.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 40 65 45 70 / 0 0 0 10
INL 33 70 45 74 / 0 0 0 0
BRD 40 70 47 69 / 0 0 0 30
HYR 35 69 43 71 / 0 0 0 20
ASX 35 65 43 72 / 0 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GSF
LONG TERM...MCLOVIN
AVIATION...WL
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
852 AM PDT THU MAY 21 2015
.SYNOPSIS...A PACIFIC STORM WILL BRING PLENTY OF CLOUD COVER TO THE
AREA OVER THE NEXT FEW DAYS AND INCREASING CHANCES FOR SHOWERS AND
THUNDERSTORMS TODAY AND FRIDAY...MAINLY NORTH OF INTERSTATE 40.
COOLER BUT STILL MILD TEMPERATURES ARE EXPECTED TODAY FOLLOWED BY
MUCH COOLER CONDITIONS ON FRIDAY. SHOWER CHANCES WILL PERSIST MAINLY
ACROSS THE SOUTHERN GREAT BASIN...WITH A WARMING TREND THROUGH THE
HOLIDAY WEEKEND.
&&
.UPDATE...JETSTREAK OVER WESTERN ARIZONA THIS MORNING LEADING TO
SOME WEAK RADAR RETURNS OVER NORTHERN MOHAVE COUNTY. THIS PROBABLY
NOTHING MORE THAN VIRGA OR SPRINKLES. DID INCREASE POPS FOR THE
HIGHER TERRAIN OF NORTHERN MOHAVE COUNTY IN THE MORNING UPDATE.
OTHERWISE...AIR MASS WILL DESTABILZE ONCE AGAIN THIS AFTERNOON UNDER
INFLUENCE OF BROAD TROUGH OVER THE WESTERN STATES. CONVECTION WILL
OCCUR MAINLY OVER THE HIGHER TERRAIN OF INYO COUNTY AND SOUTHERN
NEVADA. LATEST 12Z GFS/NAM AND 14Z HRRR SUPPORT A SLIGHT CHANCE OF A
SHOWER OR THUNDERSTORM FOR THE LAS VEGAS VALLEY LATE THIS
AFTERNOON/EARLY EVENING FOR AREAS MAINLY WEST OF I-15. WILL LEAVE IN
FOR NOW, BUT MONITOR CU DEVELOPMENT AND LATER RUNS OF THE HRRR FOR
FURTHER UPDATES.
&&
.PREV DISCUSSION...
229 AM PDT THU MAY 21 2015
.SHORT TERM...THROUGH SATURDAY NIGHT.
LOW PRESSURE OFF THE WEST COAST THIS MORNING WILL BE THE WEATHER
MAKER FOR THE AREA THROUGH THE SHORT TERM. THIS MEANS INCREASING
CHANCES FOR SHOWERS AND THUNDERSTORMS, GUSTY WINDS AT TIMES AND
COOLER CONDITIONS HEADING INTO THE MEMORIAL DAY WEEKEND.
SHOWERS ARE EXPECTED LATER THIS MORNING OVER THE SIERRA AND THEN
SPREAD EAST ACROSS THE SOUTHERN GREAT BASIN DURING THE DAY. LOCAL
MODELS FORECAST A FEW SHOWERS OVER THE LAS VEGAS VALLEY LATE THIS
AFTERNOON INTO THE EVENING HOURS.
THE LOW IS FORECAST TO TRACK FROM NEAR POINT CONCEPTION ALONG THE
SOUTHERN CAL COAST THIS EVENING...ACROSS THE MOJAVE DESERT TONIGHT
INTO EARLY FRIDAY THEN LIFT NORTHEAST THROUGH MOHAVE COUNTY ARIZONA
INTO UTAH FRIDAY AND FRIDAY NIGHT. THIS WILL GIVE US THE BEST CHANCE
OF PRECIPITATION...ESPECIALLY ACROSS THE NORTHERN PORTIONS OF THE
CWA. MOISTURE/STABILITY PROFILES AND LIFT PROVIDED BY THE LOW AND
ITS ASSOCIATED JET WILL AID IN SHOWER AND THUNDERSTORM DEVELOPMENT.
MODEL SOLUTIONS DIVERGE ON SATURDAY REGARDING SHORTWAVE ENERGY
DIVING SOUTH ALONG THE WEST COAST AND ITS INTERATION WITH THE
DEPARTING LOW OVER UTAH. THE ECMWF IS VERY PROGRESSIVE WITH THIS
FEATURE AND TAKES IT HARMLESSLY INTO NORTHERN MEXICO SATURDAY NIGHT
WHILE THE GFS AND NAM ARE STRONGER AND SLOWER...INTERACTING WITH
MOISTURE OVER THE SOUTHERN GREAT BASIN SATURDAY. THESE SOLUTIONS
WHICH ARE SUPPORTED BY THE GFS ENSEMBLE MEAN...WOULD KEEP ACTIVE
WEATHER OVER THE NORTHERN FORECAST AREA INTO SATURDAY NIGHT.
OVERALL, TEMPERATURES ALOFT STAY ON WARMER SIDE AND SNOW LEVELS ARE
EXPECTED TO REMAIN QUITE HIGH...GENERALLY ABOVE 7500-8000 FEET. SNOW
ACCUMULATIONS UP TO 8 INCHES ARE POSSIBLE IN THE HIGHER TERRAIN OF
THE SIERRA BETWEEN 5 AM THIS MORNING AND 5 AM SATURDAY WHILE ONLY
TRACE TO LIGHT AMOUNTS ARE EXPECTED ELSEWHERE. RAIN AMOUNTS DURING
THE SAME TIME FRAME COULD RANGE FROM A FEW HUNDRETHS TO A TENTH OF
SO IN THE DESERTS WITH .25-.50 INCH IN THE SOUTHERN GREAT BASIN.
LOCALLY HEAVIER AMOUNTS WILL BE POSSIBLE WHERE THUNDERSTORMS FORM.
WIND GUSTS COULD BE STRONG AT TIME IN THE WESTERN MOJAVE DESERT
LATER TODAY AND AGAIN FRIDAY AFTERNOON BUT SHOULD STAY JUST UNDER
ADVISORY LEVELS. TEMPERATURES AREA GENERALLY EXPECTED TO BE ABOUT 5
DEGREES COOLER TODAY...THEN ANOTHER 5-8 DEGREES COOLER FRIDAY BEFORE
WARMING AGAIN...BUT STAYING WELL BELOW NORMAL...ON SATURDAY.
.LONG TERM...SUNDAY THROUGH WEDNESDAY.
A LOW PRESSURE SYSTEM WILL SLIDE INTO THE PACIFIC NORTHWEST SUNDAY
AND LINGER THERE THROUGH WEDNESDAY, AT LEAST ACCORDING TO THE 00Z
MODELS. MAYBE THEY ARE FINALLY GOING TO TREND TOWARD A COMMON
SOLUTION. FOR SUNDAY, WE WILL REMAIN UNDER THE INFLUENCE OF OUR
DEPARTING TROUGH. THE WESTERN EDGE OF THIS TROUGH FINALLY PUSHES
EAST WITH THE FINAL PIECE OF ENERGY SLIDING SOUTH THROUGH CALIFORNIA
AND INTO SOUTHERN ARIZONA. QUASI-ZONAL FLOW ALOFT SETS IN MONDAY,
QUICKLY FOLLOWED BY SOUTHWEST FLOW TUESDAY AHEAD OF ANOTHER
APPROACHING TROUGH. SOME SORT OF TROUGHING/SHORTWAVE ENERGY APPEARS
TO MOVE ACROSS THE REGION WEDNESDAY, EVEN THOUGH THE MODELS PRODUCE
THIS FEATURE IN DIFFERENT WAYS. GIVEN THE PATTERN EVOLUTION, A
CHANCE OF SHOWERS WILL REMAIN POSSIBLE PRETTY MUCH EVERY DAY, MAINLY
ACROSS THE SOUTHERN SIERRA AND HIGHER TERRAIN OF THE SOUTHERN GREAT
BASIN. TEMPERATURES WILL MODERATE A BIT, WARMING TO WITHIN A FEW OF
DEGREES OF NORMAL BY WEDNESDAY. SOUTH TO SOUTHWEST BREEZES ARE
LIKELY BOTH MONDAY AND TUESDAY AFTERNOON/EARLY EVENING. &&
$$
.AVIATION...FOR MCCARRAN... SOUTHERLY WINDS OF 8-10KTS TO CONTINUE
THROUGH THE OVERNIGHT HOURS THEN BACK TO THE SOUTHEAST FOR MUCH OF
THE DAY. SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE TODAY AND
COULD IMPACT ALL APPROACH CORRIDORS. THERE REMAINS A SLIGHT CHANCE
OF A SHOWER OR THUNDERSTORM DEVELOPING IN THE LAS VEGAS VALLEY LATER
TODAY OR THIS EVENING.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SHOWERS AND THUNDERSTORMS ARE POSSIBLE NORTH OF
INTERSTATE 40 TODAY AND FRIDAY. STRONG UPDRAFTS AND CONVECTIVE
TURBULENCE...GUSTY SURFACE WINDS...AND SMALL HAIL WILL BE POSSIBLE
WITH STRONGER STORM CELLS. OTHERWISE SOUTHERLY SURFACE WINDS IN THE
10-20KT RANGE WITH GUSTS TO 25KTS ARE EXPECTED TODAY.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE...PIERCE
SHORT TERM/AVIATION...SALMEN
LONG TERM...PADDOCK
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1040 PM EDT FRI MAY 22 2015
.SYNOPSIS...
PARTLY CLOUDY SKIES WILL GIVE WAY TO CLEAR SKIES OVERNIGHT. A
VERY COLD AIR MASS WILL BE OVER THE NORTH COUNTRY OVERNIGHT WITH
LOW TEMPERATURES BY DAYBREAK ON SATURDAY IN THE UPPER 20S TO LOWER
TO MID 30S. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD INTO THE
REGION ON SATURDAY AND REMAIN THROUGH SUNDAY. A WARM FRONT WILL
APPROACH THE NORTH COUNTRY ON MONDAY AND BRING A CHANCE OF RAIN
SHOWERS TO THE REGION.
&&
.NEAR TERM /UNTIL 7 AM SATURDAY MORNING/...
AS OF 1034 PM EDT FRIDAY...ISOLATED LATE RAIN SHOWERS (AND HIGHER
SUMMIT SNOW SHOWERS) CONTINUE TO DIMINISH ACROSS CENTRAL VT AT
0215Z...AND IR IMAGERY INDICATES CLEARING SKIES ACROSS THE ST.
LAWRENCE VALLEY AND POINTS NORTH AND WEST MOVING INTO THE NORTH
COUNTRY. STRONG LOW- LEVEL CAA CONTINUES AS WELL...WITH GUSTY NW
WINDS IN PLACE...BUT TEMPS ALREADY FALLING INTO THE MID-UPR 30S
ALONG THE INTL BORDER (36F AT NEWPORT VT AT 02Z). AS SUCH...FREEZE
WARNINGS LOOK ON TRACK WITH NO CHANGES MADE AT THIS TIME.
SLIGHTLY ABOVE FREEZING FOR EARLY AM LOWS EXPECTED IN THE FROST
ADVISORY AREA ACROSS THE CHAMPLAIN VALLEY (WITH MODERATING
INFLUENCE OF LAKE CHAMPLAIN AND STRONGER LOW-LEVEL MIXING). FROST
MAY ACTUALLY BE MITIGATED A BIT BY CONTINUED MODERATE WINDS...BUT
MORE SHELTERED LOCATIONS WILL SEE SOME PATCHY FROST FORMATION WITH
LOWS 33-36F IN THE CHAMPLAIN VALLEY. 850 MB TEMPERATURES ALREADY
DOWN TO -6C ALONG THE INTL BORDER PER LATEST RUC ANALYSIS...AND
SHOULD DROP TO AROUND -7 TO -8C DURING THE PRE- DAWN HOURS.
DEFINITELY A CHILLY NIGHT FOR LATE MAY...BUT TEMPERATURES WILL
BEGIN A STRONG MODERATING TREND BEGINNING ON SATURDAY.
&&
.SHORT TERM /7 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 400 PM EDT FRIDAY...A WEAK RIDGE OF HIGH PRESSURE WILL
BUILD INTO THE REGION ON SATURDAY AND REMAIN THROUGH SUNDAY.
EXPECTING TEMPERATURES TO CLIMB INTO THE UPPER 50S TO 60S ON
SATURDAY AFTER A COLD START WITH SUNNY SKIES EXPECTED. NOT AS COLD
SATURDAY NIGHT WITH LOWS FROM THE UPPER 30S TO THE 40S.
TEMPERATURES WILL CLIMB INTO THE 70S ON SUNDAY WITH HIGHS IN THE
70S. A WARM FRONT WILL APPROACH THE SOUTHWEST SAINT LAWRENCE
VALLEY LATE SUNDAY NIGHT...SO HAVE GONE WITH SLIGHT CHANCE POPS
FOR RAIN SHOWERS FOR THE SOUTHWEST SAINT LAWRENCE VALLEY IN
NORTHERN NEW YORK.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 320 PM EDT FRIDAY...LARGE SCALE PATTERN WILL FEATURE
DEVELOPING MID/UPPER LEVEL RIDGE ACROSS THE EASTERN CONUS BY
MIDWEEK. THIS SYNOPTIC SCALE SETUP WILL RESULT IN MUCH ABOVE
NORMAL TEMPS AND DAILY CHANCES FOR AFTERNOON/EVENING
SHOWERS/STORMS. NO WIDESPREAD WETTING RAIN EVENTS ARE ANTICIPATED
THROUGH THE MIDDLE OF NEXT WEEK. HAVE CONTINUED TO MENTION CHC TO
LOW LIKELY POPS MONDAY AFTN INTO TUESDAY...ASSOCIATED WITH SFC
WARM FRNT. THIS FEATURE WILL HAVE GOOD 5H VORT TRAVELING FROM NW
TO SE ACROSS OUR REGION...WHILE A RIBBON OF ENHANCED 850 TO 500MB
RH MOVES FROM SOUTHWEST TO NORTHEAST. STILL SOME TIMING
DIFFERENCES BETWEEN THE GFS/EURO...BUT OVERALL IDEA OF A PERIOD
OF RAIN SHOWERS LOOKS GOOD. QPF WILL GENERALLY BE <0.25 FOR THIS
WARM FRONT FEATURE.
FOR TUESDAY THROUGH FRIDAY OF NEXT WEEK OUR CWA IS WELL
ESTABLISHED IN THE WARM SECTOR...AS RIBBON OF ENHANCED MID LVL
MOISTURE AND ASSOCIATED VORTS LIFT NORTH OF OUR REGION. PROGGED
925MB TEMPS RANGE BTWN 18C AND 22C DURING THIS PERIOD...SUPPORTS HIGHS
WELL INTO THE 80S WITH MAYBE A FEW READINGS NEAR 90 IN THE
CHAMPLAIN AND SAINT LAWRENCE VALLEYS...ESPECIALLY GIVEN DRY SFC
CONDITIONS. THE LACK OF FORCING AND DEEP LAYER MOISTURE WILL LIMIT
AREAL COVERAGE/INTENSITY OF STORMS...ALONG WITH AN ORGANIZED
CONVECTION. THINKING DAILY AIRMASS TYPE STORMS WILL BE
POSSIBLE...ESPECIALLY ACROSS THE HIGHER TRRN DURING THE PEAK
SURFACE HEATING. DAILY MAX CAPE VALUES RANGE BTWN 800 AND 1500
J/KG WITH SHEAR PROFILES SUPPORTING PULSE TYPE STORMS DURING THE
WEDS THRU FRIDAY TIME PERIOD. OTHERWISE...BETTER CHANCES FOR
STORMS ARRIVES NEXT WEEKEND ASSOCIATED WITH A COLD FRONT.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...VFR EXPECTED THROUGH THE PERIOD. SCT-BKN
5000-8000 FOOT CLOUD DECK THIS EVENING GRADUALLY DISSIPATES
OVERNIGHT LEADING TO CLEAR SKIES AT ALL TAF SITES AFTER 06Z.
CLEAR SKIES CONTINUE INTO SATURDAY WITH ONLY SOME SCATTERED MID
LEVEL CLOUDS MOVING IN LATER SATURDAY AFTERNOON. NORTHWEST WINDS
5-12 KNOTS THIS EVENING SLACKEN OVERNIGHT BEFORE INCREASING AGAIN
OUT OF THE WEST/NORTHWEST SATURDAY MORNING TO 8-12 KNOTS WITH
GUSTS 15-22 KNOTS...HIGHEST MPV. WINDS TURN WEST/SOUTHWEST
SATURDAY AFTERNOON WITH GUSTS 15-25 KNOTS...HIGHEST AT MSS.
OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...VFR CONDITIONS CONTINUE
FOR SUNDAY INTO MONDAY...BEFORE A WEAK WARM FRONT WILL PRODUCE A
PERIOD OF LIGHT RAIN SHOWERS ON MONDAY AFTN INTO TUESDAY. A PERIOD
OF MVFR CIGS WILL BE POSSIBLE...ESPECIALLY IN THE MOUNTAINS. THE
CHANCES FOR AFTERNOON SHOWERS AND THUNDERSTORMS WILL CONTINUE FOR
WEDS...WITH BRIEF MVFR CIGS/VIS IN THE HEAVIER STORMS...MAINLY
DURING THE PEAK HEATING HOURS.
&&
.FIRE WEATHER...
A VERY DRY PERIOD CONTINUES ACROSS OUR REGION WITH MANY LOCATIONS
4 TO 6 INCHES BELOW NORMAL PRECIPITATION YEAR TO DATE. THE LATEST
US DROUGHT MONITOR HAS THE SAINT LAWRENCE VALLEY AND PARTS OF
SOUTHERN/CENTRAL VERMONT IN MODERATE DROUGHT CONDITIONS WITH
ABNORMALLY DRY ELSEWHERE. THESE DRY CONDITIONS HAVE PRODUCED VERY
DRY DEAD FUELS PER COORDINATION WITH VERMONT DEPT OF FOREST, PARK,
AND RECREATION. THESE DRY FUELS COMBINED WITH BREEZY SOUTHWEST TO
WEST WINDS SATURDAY AND MINIMUM AFTERNOON RELATIVE HUMIDITY VALUES
BETWEEN 17 AND 25% WILL INCREASE FIRE WEATHER CONCERNS. THE
STRONGEST WINDS WILL OCCUR BETWEEN NOON AND 7 PM...WHILE RH`S
WILL BE THE LOWEST BETWEEN 2 PM AND 6 PM ON SATURDAY. LOCALIZED
WIND GUSTS BETWEEN 20 AND 25 MPH WILL BE POSSIBLE IN THE SOUTHWEST
TO NORTHEAST ALIGNED SAINT LAWRENCE VALLEY AND PARTS OF CENTRAL
AND EASTERN VERMONT. GIVEN THE EXPECTED WEATHER CONDITIONS AND
VERY DRY FUELS...WE WILL ISSUE AN SPECIAL WEATHER STATEMENT TO
HIGHLIGHT THE FIRE WEATHER CONCERN...AS WINDS ARE MARGINAL AND
KEETCH BYRAM DROUGHT INDEX IS < 300 ACROSS OUR REGION.
HOWEVER...GIVEN THE CONDITIONS ABOVE ANY FIRES THAT DO OCCUR COULD
SPREAD QUICKLY...BURN INTENSELY AND BE DIFFICULT TO CONTAIN ON
SATURDAY.
&&
.MARINE...
AS OF 306 PM EDT FRIDAY...A LAKE WIND ADVISORY IS IN EFFECT FOR
LAKE CHAMPLAIN TONIGHT. NORTHWEST WINDS HAVE GENERALLY BEEN IN THE
10 TO 20 KNOT RANGE. STRENGTHENING PRESSURE GRADIENT SHOULD BE
ABLE TO PUSH LAKE WINDS TO LAKE WIND ADVISORY CRITERIA, IN THE 15
TO 25 KNOT RANGE, THROUGH AT LEAST THE FIRST HALF OF TONIGHT.
THEREAFTER, A SLACKENING PRESSURE GRADIENT SHOULD ALLOW FOR LAKE
WINDS TO SUBSIDE UNDER CRITERIA TOWARDS THE MORNING HOURS. EXPECT
WAVES TO BE IN THE 1 TO 3 FOOT RANGE WITH A MODERATE CHOP. HIGHEST
WAVES WILL TEND TO BE IN AREAS EXPOSED TO THE NORTH.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...FREEZE WARNING UNTIL 8 AM EDT SATURDAY FOR VTZ003-004-006>008-
010-012-016>019.
FROST ADVISORY UNTIL 8 AM EDT SATURDAY FOR VTZ002-005-009-011.
NY...FREEZE WARNING UNTIL 8 AM EDT SATURDAY FOR NYZ026-027-029>031-
034-087.
FROST ADVISORY UNTIL 8 AM EDT SATURDAY FOR NYZ028-035.
&&
$$
SYNOPSIS...WGH
NEAR TERM...BANACOS/WGH
SHORT TERM...WGH
LONG TERM...TABER
AVIATION...TABER/MUCCILLI
FIRE WEATHER...TABER
MARINE...LOCONTO
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
606 PM EDT THU MAY 21 2015
.SYNOPSIS...
LOW PRESSURE ALONG A COLD FRONT WILL SHIFT OFF THE COAST OVERNIGHT
MOVING THE COLD FRONT OFF THE COAST. COOLER HIGH PRESSURE WILL
BUILD INTO REGION FRIDAY AND CONTINUE INTO THE WEEKEND. AS THE
HIGH PRESSURE SHIFTS OFF THE COAST BY THE MIDDLE OF NEXT WEEK
HIGHER HUMDITIES WILL RETURN TO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 PM THURSDAY..SEVERE THUNDERSTORM WATCH 193 HAS BEEN
CANCELLED FOR THE ENTIRE AREA. RELEVANT PORTION OF PREVIOUS
DISCUSSION FROM 3 PM FOLLOWS BELOW:
DRY AIR WILL ADVECT IN BEHIND THIS TROUGH WITH DEWPOINT TEMPS
ALREADY DROPPING WEST OF I95 FROM NEAR 70 DOWN CLOSER TO 60 BY MID
AFTERNOON. TEMPS WILL BE SLOWER TO DROP IN CONTINUED SUNSHINE
THROUGH THE NEXT SEVERAL HOURS.
THEN THE MAIN H5 TROUGH EXTENDING DOWN FROM GREAT LAKES WILL
PUSH A COLD FRONT SOUTH AS IT MOVES EAST OVERNIGHT. SFC WINDS WILL
VEER AROUND QUITE ABRUPTLY AS THIS FRONT MOVES DOWN FROM THE
NORTH LATE EVENING INTO THE OVERNIGHT HOURS. A COUPLE OF THE MESO
MODELS WERE SHOWING A COUPLE OF SHWRS AS THIS FRONT MOVES THROUGH
BUT FOR NOW WILL KEEP POPS OUT OF FORECAST AFTER THIS INITIAL LINE
PASSES WITH DRIER AND RELATIVELY COOLER AIR MOVING IN. 850 TEMPS
WILL DROP FROM NEAR 16 C LATE THIS AFTERNOON DOWN TO 9C BY
MORNING. OVERALL EXPECT A COMPLETE CHANGE IN AIR MASS WITH WARMER
MORE HUMID AIR MASS TRANSITIONING TO A MORE SEASONABLE RELATIVELY
DRIER AIR MASS. TEMPS TONIGHT WILL BE SLOWER TO DROP INITIALLY BUT
ONCE FRONT DROPS SOUTH...TEMPS AND DEWPOINTS WILL FALL MORE
RAPIDLY WITH TEMPS DOWN NEAR 60 BY DAYBREAK.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...AS THE FRONT EXITS THE FORECAST REGION...COOLER
DRY HIGH PRESSURE WILL MOVE IN. GFS AND NAM ARE SHOWING THE
PRECIPITABLE WATER VALUES FALLING TO A RANGE OF 0.5 TO 1 INCHES.
THE HIGH PRESSURE CENTER WILL STAY TO THE NORTH DURING THIS PERIOD.
NO PRECIPITATION IS EXPECTED THROUGH THIS PERIOD AND MAXIMUM
TEMPERATURES ARE EXPECTED TO BE IN THE UPPER 70S FRIDAY AND AROUND
80 ON SATURDAY. LOWS EACH NIGHT SHOULD BOTTOM OUT IN THE MIDDLE
50S FRIDAY NIGHT AND THE UPPER 50S ON SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...SURFACE HIGH PRESSURE WILL BE CENTERED JUST
TO THE NORTH OF THE AREA AND WILL SHIFT OFF THE COAST BY THE
BEGINNING OF NEXT WEEK. THE AREA WILL SEE A RETURN OF ONSHORE
FLOW...A RETURN TO HIGHER HUMIDITIES...AND A WARM UP IN TEMPERATURES.
ALOFT A RIDGE STUBBORNLY HOLDS ON THROUGH ALMOST THURSDAY SO THE
CHANCES OF PRECIPITATION WILL BE MINIMAL THROUGH AT LEAST EARLY
TUESDAY AND MAYBE AN ISOLATED CHANCE OF A DIURNAL SHOWERS OR
THUNDERSTORMS BY LATE TUESDAY THROUGH THURSDAY. MAXIMUM TEMPERATURES
WILL REBOUND TO AROUND 90 BY TUESDAY AND REMAIN AT THOSE LEVELS
THROUGH THURSDAY. MINIMUM TEMPERATURES WILL BE IN THE LOWER 60S
ON SUNDAY NIGHT AND WILL SLOWLY RISE INTO THE UPPER 60S BY
WEDNESDAY NIGHT.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...THE HRRR MODEL CONTINUES TO SHOW MODERATE CONVECTION
OVER NORTHERN TERMINALS THROUGH THE AFTERNOON HOURS. THIS AGREES
WITH THE LATEST 12Z RUN OF THE NAM. KLBT WILL BE UNDER THE GUN
19-21Z WITH KILM 20-24Z. AT KCRE MOIST ONSHORE FLOW COULD RESULT
IN TEMPO IFR MARINE STRATUS CIGS THROUGH 20Z...POSSIBLY A FEW
HOURS LATER IF WINDS DO NOT SHIFT FURTHER TO THE SW LATER THIS
AFTERNOON. CONVECTION SHOULD MOVE OFF EARLY THIS EVENING. SW-W
WINDS WILL SHIFT TO THE NORTH TONIGHT AS LOW PRESSURE PULLS OFF TO
THE NE. MUCH DRIER AIR WILL USHER IN OVERNIGHT...WITH VFR CONDITIONS
EXPECTED FOR FRIDAY WITH SCATTERED SKIES.
EXTENDED OUTLOOK...VFR. MORNING FOG POSSIBLE MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/... AS OF 600 PM THURSDAY...SEVERE
THUNDERSTORM WATCH 193 HAS BEEN CANCELLED. RELEVANT PORTION OF
PREVIOUS DISCUSSION BELOW:
SW WINDS 15 TO 20 KT AHEAD OF A COASTAL TROUGH...WILL SHIFT TO THE W-
NW THROUGH THIS EVENING AS IT SHIFTS OFF SHORE. THE ASSOCIATED COLD
FRONT WILL GET PUSHED SOUTH TONIGHT WITH A MORE ABRUPT SHIFT OF
WINDS TO THE N LATE THIS EVENING INTO THE OVERNIGHT HOURS. THIS WILL
PRODUCE A NORTHERLY SURGE WITH WINDS INCREASING TO AROUND 20 KT LATE
TONIGHT. MODELS CONTINUE TO SHOW WINDS AND SEAS REACHING NEAR SMALL
CRAFT SHOULD EXERCISE CAUTION THRESHOLDS. SEAS 2 TO 4 FT THROUGH
THIS EVENING INTO OVERNIGHT MAY SEE SOME 5 FOOTERS OVERNIGHT ACROSS
THE OUTERMOST WATERS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...A COLD FRONT WILL HAVE PUSHED EAST OF THE
WATERS AND HIGH PRESSURE WILL BUILD OVER THE WATERS. WINDS WILL
BE FROM THE NORTH AT 15 TO 20 KNOTS ON FRIDAY MORNING AND WILL
SLOWLY WEAKEN TO 10 TO 15 KTS BY THE OF END FRIDAY AND REMAIN AT
THESE SPEEDS. WINDS WILL BEGIN THE DAY FROM THE NORTH AND WILL
VEER TO THE EAST BY SATURDAY. SEA HEIGHTS WILL START OUT AT 2 TO 4
FEET EARLY FRIDAY AND WILL SETTLE OUT AT 2 TO 3 FEET THROUGH
SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...HIGH PRESSURE WILL RULE THE COASTAL WATERS
WITH SOUTHEAST WINDS OF 10 KNOTS SLOWLY SHIFTING TO THE SOUTH AT
10 KNOTS BY TUESDAY. SEAS WILL REMAIN AT 2 TO 3 FEET FOR THE
ENTIRE FORECAST PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ/JDW
SHORT TERM...HAWKINS
LONG TERM...HAWKINS
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
343 PM EDT THU MAY 21 2015
.SYNOPSIS...
LOW PRESSURE ALONG A COLD FRONT WILL SHIFT OFF THE COAST OVERNIGHT
MOVING THE COLD FRONT OFF THE COAST. COOLER HIGH PRESSURE WILL
BUILD INTO REGION FRIDAY AND CONTINUE INTO THE WEEKEND. AS THE
HIGH PRESSURE SHIFTS OFF THE COAST BY THE MIDDLE OF NEXT WEEK
HIGHER HUMDITIES WILL RETURN TO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM THURSDAY...SEVERE
THUNDERSTORM WATCH 193 REMAINS IN EFFECT FOR SOUTHEAST NC THROUGH 8
PM. TROUGH EXTENDING FROM LOW PRESSURE AT THE SURFACE ALONG WITH
SHORTWAVE IN THE MID LEVELS WILL CONTINUE TO COMBINE WITH HEATING OF
THE DAY AND MOISTURE RICH AIR TO TO TRIGGER SHOWERS AND
THUNDERSTORMS ACROSS THE EASTERN CAROLINAS THIS AFTERNOON. THESE
THUNDERSTORMS MAY CONTAIN DAMAGING WINDS AND POSSIBLE HAIL. CAN NOT
RULE OUT AN ISOLATED TORNADO. A FAIRLY DECENT LINE SEGMENT DEVELOPED
JUST WEST OF ILM CWA EXTENDING INTO MARLBORO AND DARLINGTON COUNTIES
EARLY THIS AFTERNOON. THIS LINE ALONG I95 MID AFTERNOON WILL MOVE
EAST TOWARD THE COAST. IT REMAINS ALIGNED ALONG STEEP MOISTURE
GRADIENT AS EVIDENT ON WATER VAPOR IMAGERY AS WELL AS BEST
CONVERGENCE ALONG SFC TROUGH EXTENDING FROM LOW. DRY AIR WILL PUNCH
IN FROM THE WEST PROVIDING SOME DECENT DOWNDRAFT POTENTIAL WITH
THESE STORMS.
THIS TROUGH OF LOW PRESSURE WITH LINE OF CONVECTION WAS RUNNING
DOWN ALONG I95 MID AFTERNOON AND WILL CONTINUE EAST WITH LOW
BECOMES ELONGATED DOWN THE EAST COAST THROUGH EARLY THIS EVENING.
DRY AIR WILL ADVECT IN BEHIND THIS TROUGH WITH DEWPOINT TEMPS
ALREADY DROPPING WEST OF I95 FROM NEAR 70 DOWN CLOSER TO 60 BY MID
AFTERNOON. TEMPS WILL BE SLOWER TO DROP IN CONTINUED SUNSHINE
THROUGH THE NEXT SEVERAL HOURS.
THEN THE MAIN H5 TROUGH EXTENDING DOWN FROM GREAT LAKES WILL
PUSH A COLD FRONT SOUTH AS IT MOVES EAST OVERNIGHT. SFC WINDS WILL
VEER AROUND QUITE ABRUPTLY AS THIS FRONT MOVES DOWN FROM THE
NORTH LATE EVENING INTO THE OVERNIGHT HOURS. A COUPLE OF THE MESO
MODELS WERE SHOWING A COUPLE OF SHWRS AS THIS FRONT MOVES THROUGH
BUT FOR NOW WILL KEEP POPS OUT OF FORECAST AFTER THIS INITIAL LINE
PASSES WITH DRIER AND RELATIVELY COOLER AIR MOVING IN. 850 TEMPS
WILL DROP FROM NEAR 16 C LATE THIS AFTERNOON DOWN TO 9C BY
MORNING. OVERALL EXPECT A COMPLETE CHANGE IN AIR MASS WITH WARMER
MORE HUMID AIR MASS TRANSITIONING TO A MORE SEASONABLE RELATIVELY
DRIER AIR MASS. TEMPS TONIGHT WILL BE SLOWER TO DROP INITIALLY BUT
ONCE FRONT DROPS SOUTH...TEMPS AND DEWPOINTS WILL FALL MORE
RAPIDLY WITH TEMPS DOWN NEAR 60 BY DAYBREAK.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...AS THE FRONT EXITS THE FORECAST REGION...COOLER
DRY HIGH PRESSURE WILL MOVE IN. GFS AND NAM ARE SHOWING THE
PRECIPITABLE WATER VALUES FALLING TO A RANGE OF 0.5 TO 1 INCHES.
THE HIGH PRESSURE CENTER WILL STAY TO THE NORTH DURING THIS PERIOD.
NO PRECIPITATION IS EXPECTED THROUGH THIS PERIOD AND MAXIMUM
TEMPERATURES ARE EXPECTED TO BE IN THE UPPER 70S FRIDAY AND AROUND
80 ON SATURDAY. LOWS EACH NIGHT SHOULD BOTTOM OUT IN THE MIDDLE
50S FRIDAY NIGHT AND THE UPPER 50S ON SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...SURFACE HIGH PRESSURE WILL BE CENTERED JUST
TO THE NORTH OF THE AREA AND WILL SHIFT OFF THE COAST BY THE
BEGINNING OF NEXT WEEK. THE AREA WILL SEE A RETURN OF ONSHORE
FLOW...A RETURN TO HIGHER HUMIDITIES...AND A WARM UP IN TEMPERATURES.
ALOFT A RIDGE STUBBORNLY HOLDS ON THROUGH ALMOST THURSDAY SO THE
CHANCES OF PRECIPITATION WILL BE MINIMAL THROUGH AT LEAST EARLY
TUESDAY AND MAYBE AN ISOLATED CHANCE OF A DIURNAL SHOWERS OR
THUNDERSTORMS BY LATE TUESDAY THROUGH THURSDAY. MAXIMUM TEMPERATURES
WILL REBOUND TO AROUND 90 BY TUESDAY AND REMAIN AT THOSE LEVELS
THROUGH THURSDAY. MINIMUM TEMPERATURES WILL BE IN THE LOWER 60S
ON SUNDAY NIGHT AND WILL SLOWLY RISE INTO THE UPPER 60S BY
WEDNESDAY NIGHT.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...THE HRRR MODEL CONTINUES TO SHOW MODERATE CONVECTION
OVER NORTHERN TERMINALS THROUGH THE AFTERNOON HOURS. THIS AGREES
WITH THE LATEST 12Z RUN OF THE NAM. KLBT WILL BE UNDER THE GUN
19-21Z WITH KILM 20-24Z. AT KCRE MOIST ONSHORE FLOW COULD RESULT
IN TEMPO IFR MARINE STRATUS CIGS THROUGH 20Z...POSSIBLY A FEW
HOURS LATER IF WINDS DO NOT SHIFT FURTHER TO THE SW LATER THIS
AFTERNOON. CONVECTION SHOULD MOVE OFF EARLY THIS EVENING. SW-W
WINDS WILL SHIFT TO THE NORTH TONIGHT AS LOW PRESSURE PULLS OFF TO
THE NE. MUCH DRIER AIR WILL USHER IN OVERNIGHT...WITH VFR CONDITIONS
EXPECTED FOR FRIDAY WITH SCATTERED SKIES.
EXTENDED OUTLOOK...VFR. MORNING FOG POSSIBLE MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM THURSDAY...SEVERE THUNDERSTORM WATCH 193 HAS BEEN
ISSUED FOR SOUTHEAST NC INTO THE LOCAL COASTAL WATERS NORTH OF
CAPE FEAR THROUGH 8 PM. SW WINDS 15 TO 20 KT AHEAD OF A COASTAL
TROUGH...WILL SHIFT TO THE W-NW THROUGH THIS EVENING AS IT SHIFTS
OFF SHORE. THE ASSOCIATED COLD FRONT WILL GET PUSHED SOUTH TONIGHT
WITH A MORE ABRUPT SHIFT OF WINDS TO THE N LATE THIS EVENING INTO
THE OVERNIGHT HOURS. THIS WILL PRODUCE A NORTHERLY SURGE WITH
WINDS INCREASING TO AROUND 20 KT LATE TONIGHT. MODELS CONTINUE TO
SHOW WINDS AND SEAS REACHING NEAR SMALL CRAFT SHOULD EXERCISE
CAUTION THRESHOLDS. SEAS 2 TO 4 FT THROUGH THIS EVENING INTO
OVERNIGHT MAY SEE SOME 5 FOOTERS OVERNIGHT ACROSS THE OUTERMOST
WATERS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...A COLD FRONT WILL HAVE PUSHED EAST OF THE
WATERS AND HIGH PRESSURE WILL BUILD OVER THE WATERS. WINDS WILL
BE FROM THE NORTH AT 15 TO 20 KNOTS ON FRIDAY MORNING AND WILL
SLOWLY WEAKEN TO 10 TO 15 KTS BY THE OF END FRIDAY AND REMAIN AT
THESE SPEEDS. WINDS WILL BEGIN THE DAY FROM THE NORTH AND WILL
VEER TO THE EAST BY SATURDAY. SEA HEIGHTS WILL START OUT AT 2 TO 4
FEET EARLY FRIDAY AND WILL SETTLE OUT AT 2 TO 3 FEET THROUGH
SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...HIGH PRESSURE WILL RULE THE COASTAL WATERS
WITH SOUTHEAST WINDS OF 10 KNOTS SLOWLY SHIFTING TO THE SOUTH AT
10 KNOTS BY TUESDAY. SEAS WILL REMAIN AT 2 TO 3 FEET FOR THE
ENTIRE FORECAST PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...HAWKINS
LONG TERM...HAWKINS
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
315 PM EDT THU MAY 21 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE OFF OF THE COAST TONIGHT. HIGH PRESSURE
WILL BUILD INTO THE AREA FROM THE NORTHWEST TONIGHT AND FRIDAY.
THE HIGH WILL THEN GRADUALLY MOVE OFFSHORE AND PROVIDE DRY AND
SEASONABLY MILD WEATHER THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 315 PM THURSDAY...CONVECTION FIRING AS EXPECTED IN ADVANCE
OF LOW MOVING EAST ALONG DIFFUSE WARM FRONT BISECTING EASTERN NC
THIS AFTERNOON. EARLIER INSOLATION HELPED TO DESTABILIZE THE
ATMOSPHERE AND WITH INCREASING MID LEVEL FLOW EXPECTED
THUNDERSTORM ORGANIZATION WILL INCREASE AND WITH IT THE THREAT FOR
SEVERE WEATHER. THE MAIN CONCERNS BEING LARGE HAIL AND
DAMAGING WINDS ALTHOUGH AN ISOLATED TORNADO CANNOT BE RULED OUT.
PRECIPITATION SHOULD EAST OF THE COASTAL PLAIN BY 22Z AND
ALONG/OFF THE COAST BY 00Z. NOT EXPECTING MUCH IF ANY
PRECIPITATION AFTER 00Z BUT WILL HOLD ONTO A 30% POP THROUGH 03Z
AS THE HRRR AND RAP-13 MODELS PRODUCE PRECIPITATION AFTER 00Z.
OVERNIGHT LOWS WILL BE COOLER THAN LAST NIGHT WITH READINGS IN THE
MIDDLE TO UPPER 50S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
AS OF 315 PM THURSDAY...HIGH PRESSURE BUILDING OVER THE AREA FROM
THE NORTH WILL PRODUCE COOLER/DRIER WEATHER ACROSS NC FRIDAY.
HIGHS WILL BE IN THE LOWER TO MIDDLE 70S WITH A FEW UPPER 70S
POSSIBLE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM THU...SEVERAL DAYS OF DRY WEATHER. SURFACE RIDGE OVER
THE EASTERN SEABOARD SATURDAY WILL MOVE OFF THE COAST SUNDAY AND
REMAIN OVER THE WESTERN ATLANTIC THROUGH MIDWEEK. WARM AND HUMID
CONDITIONS DEVELOP EARLY NEXT WEEK IN SOUTHWEST FLOW. COASTAL
PLAINS TROF SETS UP BY WEDNESDAY AND THURSDAY WITH A CHANCE FOR
AFTERNOON AND EVENING CONVECTION GENERALLY ALONG AND WEST OF
HIGHWAY 17.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH 18Z FRIDAY/...
AS OF 130 PM THURSDAY...CONDITIONS WILL BECOME MVFR FOR THIS
AFTERNOON AS A WARM FRONT LIFTS NORTH THROUGH THE AREA. MOST OF THE
TAF SITES ARE CURRENTLY IN VFR CONDITIONS...BUT ALL THIS WILL
CHANGE ONCE LOW LEVEL CLOUDS START TO LIFT NORTH AND GOOD COVERAGE
OF SHOWERS AND THUNDERSTORMS START TO DEVELOP THIS AFTERNOON.
VISIBILITY MAY REDUCED WITH THE HEAVIER RAINFALL ASSOCIATED WITH
STRONG THUNDERSTORMS (EXPECT GUSTY WINDS). WINDS WILL SHIFT TO
THE NORTH TONIGHT AS THE LOW LIFTS TO THE NE.
FORECASTING SOUNDING CONTINUES TO SHOW LOW LEVEL MOISTURE WILL KEEP
CONDITIONS MVFR OR LOWER....BUT AT THIS MOMENT HAVE INDICATED SCT AT
700 FT AS CONFIDENCE REMAINS LOW. LIGHT NORTHERLY WINDS WILL HELP
PRECLUDE FOG DEVELOPMENT. EXPECT VFR CONDITIONS FOR FRIDAY UNDER
FEW TO SCATTERED CLOUDS.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 3 PM THU...DRY/VFR THROUGH THE PERIOD. LIGHT NORTH SURFACE
FLOW SATURDAY THEN LIGHT SOUTHERLY SUNDAY THROUGH TUESDAY.
&&
.MARINE...
SHORT TERM /THROUGH FRIDAY/...
AS OF 315 PM THURSDAY...LOW PRESSURE WILL MOVE ACROSS THE WATERS
THIS EVENING WITH THE FLOW VEERING FROM MODERATE SOUTHERLY TO
NORTHERLY TONIGHT. AS WINDS BECOME NORTH THEY WILL INCREASE TO 20
TO 25 KT OVER THE NORTHERN WATERS WITH SEAS BUILDING TO 4 TO 6 FT
OVER THE NORTHERN AND CENTRAL WATERS. THE COMBINATION OF MODERATE
FLOW AND GUSTY NORTH WINDS TONIGHT WILL PRODUCE MARGINAL ADVISORY
CONDITIONS OVER THE NORTHERN AND CENTRAL WATERS TONIGHT INTO
FRIDAY MORNING. AS HIGH PRESSURE BUILDS OVER THE WATERS FRIDAY
WINDS WILL DIMINISH TO 10 TO 15 KT AND SEAS WILL SUBSIDE TO 3 TO 5
FT.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 3 PM THU..DRY FRONT WILL DROP THROUGH FRIDAY NIGHT.
TEMPORARY SURGE IN WINDS/SEAS LATE FRIDAY NIGHT INTO EARLY
SATURDAY BUT WILL REMAIN BELOW SMALL CRAFT LEVELS. GENERALLY
LIGHT WINDS AND SEAS FOR THE REMAINDER OF THE LONG TERM. HIGH
PRESSURE WILL MOVE OFF THE EAST COAST SATURDAY NIGHT AND WILL
REMAIN OVER THE WESTERN ATLANTIC EARLY NEXT WEEK. LIGHT NORTHERLY
FLOW SATURDAY WILL BECOME LIGHT SOUTHERLY SUNDAY THROUGH TUESDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT FRIDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
FRIDAY FOR AMZ150.
&&
$$
SYNOPSIS...JME
NEAR TERM...JME
SHORT TERM...JME
LONG TERM...HSA
AVIATION...HSA/BM
MARINE...JME/HSA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
147 PM EDT THU MAY 21 2015
.SYNOPSIS...
A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR SOUTHEAST NORTH
CAROLINA INTO THE LOCAL COASTAL WATERS NORTH OF CAPE FEAR THROUGH
8 PM. ANY SEVERE THUNDERSTORMS WILL TRACK EAST AS TROUGH OF LOW
PRESSURE TRACKS EAST TOWARD THE COAST THROUGH THIS AFTERNOON. AS
LOW PRESSURE DEPARTS WELL TO OUR NORTHEAST...IT WILL DRAG A COLD
FRONT ACROSS THE AREA LATE IN THE DAY AND THIS EVENING. HIGH
PRESSURE WILL BUILD ACROSS THE EASTERN CAROLINAS FRIDAY AND
SATURDAY. THE HIGH WILL MOVE OFFSHORE SUNDAY...BRINGING A RETURN
TO HIGHER HUMIDITY BY TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM THURSDAY...SEVERE THUNDERSTORM WATCH 193 HAS BEEN
ISSUED FOR SOUTHEAST NC THROUGH 8 PM. APPROACH OF A WAVE OF LOW
PRESSURE AT THE SURFACE ALONG WITH SHORTWAVE IN THE MID LEVELS
WILL COMBINE WITH HEATING OF THE DAY AND MOISTURE RICH AIR TO TO
CONTINUE TO TRIGGER SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN
CAROLINAS LATE MORNING. THESE THUNDERSTORMS MAY CONTAIN DAMAGING
WINDS AND HAIL. CAN NOT RULE OUT AN ISOLATED TORNADO. A FAIRLY
DECENT LINE SEGMENT HAS DEVELOPED JUST WEST OF ILM CWA INTO
MARLBORO AND DARLINGTON COUNTIES EARLY THIS AFTERNOON ALIGNED WITH
BEST CONVERGENCE ALONG SFC TROUGH AS DRY AIR PUNCHES IN FROM THE
WEST AS EVIDENT ON WATER VAPOR IMAGERY.
THE MID LEVEL SHORTWAVE WILL MOVE ACROSS THE FORECAST AREA NEAR
THE TIME OF PEAK HEATING WITH THE UPPER JET IN A FAVORABLE
POSITION FOR ORGANIZED STORMS TO DEVELOP. THE BEST MOISTURE WILL
BE LOCATED TO THE SOUTH OF WARM FRONT AND CLOSER TO THE COAST WITH
DEWPOINTS UP AROUND 70. THE MARGINAL AREA OUTLINED BY SPC LINES UP
WITH BEST CONVECTIVE PARAMETERS...WITH ML CAPE CLOSE TO 1200 J/KG
AND BULK SHEAR VALUES WILL REACH AROUND 35 KT...HIGHEST ACROSS
SOUTHEAST NORTH CAROLINA. DCAPE WILL BE ABOVE 500 AS SW-WESTERLY
FLOW ALOFT WILL PROMOTE DRYING THROUGH THE MID LEVELS AND A
GREATER INVERTED V TYPE PROFILE THROUGH THE AFTERNOON. THE
DOWNSLOPING WESTERLY FLOW WILL ALSO PRODUCE MORE SUBSIDENCE WHICH
COULD ACT AGAINST CONVECTIVE DEVELOPMENT....BUT THIS WESTERLY
FLOW ALOFT WILL ALSO ALLOW FOR GREATER VERTICAL SHEAR AND MAY SEE
A FEW LINE SEGMENTS DEVELOP WITH POTENTIAL FOR DAMAGING
WIND. CAN NOT RULE OUT SOME HAIL OR BRIEF TORNADO...AS WELL. EXPECT
THIS TO AFFECT MAINLY THE NORTHERN TIER COUNTIES OF LOCAL CWA AND
MAINLY OVER EASTERN NORTH CAROLINA. KEPT POPS HIGHEST IN THIS
AREA. POPS WILL TREND DOWN TO CHANCE AND SLIGHT CHANCE ACROSS MOST
OF SOUTH CAROLINA. ANY STORMS AND CONVECTIVE DEBRIS CLOUDS WILL
MOVE SWIFTLY OFF TO THE EAST IN A 25 TO 35 KT WESTERLY STEERING
FLOW.
THE LINGERING WEAK FRONT WHICH HAS PUSHED BACK NORTH AS A WARM
FRONT WILL GET NUDGED EAST THROUGH THE DAY AS AS SFC LOW SWEEPS
ACROSS THE CAROLINAS AND OFF SHORE BY THIS EVENING. THE BEST CHC
OF MORE WIDESPREAD CONVECTION WILL BE ALONG AND N OF THE LOW
PRESSURE TRACK....PROVIDING THE NECESSARY LIFT FOR SHOWERS AND
THUNDERSTORMS. THEREFORE AS LOW TRACKS OFF THE COAST BY EARLY THIS
EVENING ANY CONVECTION WILL COME TO AN END.
A TRAILING COLD FRONT SHOULD SWEEP OFFSHORE AS LOW PRESSURE PULLS
OFF TO THE NE INTO THIS EVE...BRINGING DRIER AND MORE STABLE AIR
INTO THE AREA OVERNIGHT. WE WILL BE ON THE SOUTHERN PERIPHERY OF
ANOTHER WEAK MID-LEVEL TROUGH PIVOTING AROUND UPPER LOW ACROSS
SOUTHEAST CANADA. THIS MAY BRING AN UPTICK IN CLOUD COVER
OVERNIGHT...BUT NO RAINFALL.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...FAIR WEATHER WITH LOW RELATIVE HUMIDITY
IS EXPECTED THROUGH THE PERIOD AS HIGH PRESSURE SETTLES OVER THE
AREA. MAX TEMPERATURES EACH DAY WILL BE IN THE UPPER 70S TO
LOWER 80S...THOUGH SATURDAY SHOULD BE A DEGREE OR TWO WARMER THAN
FRIDAY. MINS FRIDAY NIGHT WILL FALL TO THE UPPER 50S TO LOWER 60S
AND MODERATE SLIGHTLY TO THE LOW TO MID 60S SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...SURFACE HIGH PRESSURE WILL REMAIN OVER THE
AREA THROUGH THE PERIOD AS A HIGH PRESSURE RIDGE BUILDS IN ALOFT
BY THE MIDDLE OF THE WEEK. THE RESULT WILL BE FAIR WEATHER THROUGH
THE PERIOD BUT TEMPERATURES AND HUMIDITY WILL BE ON THE RISE. MAX
TEMPERATURES WILL MODERATE FROM LOW TO MID 80S SUNDAY TO MID 80S TO
AROUND 90 BY WEDNESDAY. MIN TEMPERATURES WILL ALSO BE ON THE RISE
THROUGH THE PERIOD...GOING FROM LOW TO MID 60S SUNDAY NIGHT TO UPPER
60S TO LOWER 70S BY WEDNESDAY NIGHT. DRY WEATHER IS EXPECTED
THROUGH MOST OF THE PERIOD...THOUGH A SLIGHTLY WEAKER UPPER RIDGE
WEDNESDAY COULD ALLOW FOR THE DEVELOPMENT OF ISOLATED THUNDERSTORMS
DURING THE AFTERNOON AND EVENING.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...THE HRRR MODEL CONTINUES TO SHOW MODERATE CONVECTION
OVER NORTHERN TERMINALS THROUGH THE AFTERNOON HOURS. THIS AGREES
WITH THE LATEST 12Z RUN OF THE NAM. KLBT WILL BE UNDER THE GUN
19-21Z WITH KILM 20-24Z. AT KCRE MOIST ONSHORE FLOW COULD RESULT
IN TEMPO IFR MARINE STRATUS CIGS THROUGH 20Z...POSSIBLY A FEW
HOURS LATER IF WINDS DO NOT SHIFT FURTHER TO THE SW LATER THIS
AFTERNOON. CONVECTION SHOULD MOVE OFF EARLY THIS EVENING. SW-W
WINDS WILL SHIFT TO THE NORTH TONIGHT AS LOW PRESSURE PULLS OFF TO
THE NE. MUCH DRIER AIR WILL USHER IN OVERNIGHT...WITH VFR CONDITIONS
EXPECTED FOR FRIDAY WITH SCATTERED SKIES.
EXTENDED OUTLOOK...VFR. MORNING FOG POSSIBLE MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM THURSDAY...SEVERE THUNDERSTORM WATCH 193 HAS BEEN
ISSUED FOR SOUTHEAST NC INTO THE LOCAL COASTAL WATERS NORTH OF
CAPE FEAR THROUGH 8 PM. SW WINDS 15 TO 20 KT AHEAD OF A COLD
FRONT...WILL SHIFT TO THE NW THIS EVE...AND THEN N OVERNIGHT AS
LOW PRESSURE TO OUR N MOVES FURTHER AWAY. A DEVELOPING NORTHERLY
SURGE WILL INCREASE WINDS TO AROUND 20 KT LATE TONIGHT AND WE WILL
BE NEAR SMALL CRAFT SHOULD EXERCISE CAUTION LEVELS. SEAS WILL BE 2
TO 4 FT TODAY WITH SOME 5 FT SEAS ACROSS THE OUTERMOST WATERS LATE
TONIGHT. WINDS AND SEAS WILL BE LOCALLY HIGHER IN SCATTERED TO
NUMEROUS THUNDERSTORMS TODAY AND THIS EVE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...LOOKS LIKE A QUIET PERIOD ON THE WATERS WITH
NE WINDS OF 10 TO 15 KT FRIDAY INTO SATURDAY THAT WILL BECOME MORE
EASTERLY BY SATURDAY NIGHT. SEAS OF 3 FEET OR LESS ARE EXPECTED
THROUGH THE PERIOD.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SUMMER LIKE CONDITIONS WILL CONTINUE ON THE
WATERS WITH SE WINDS OF 10 TO 15 KT EXPECTED THROUGH THE FORECAST
PERIOD WITH SEAS OF 3 FT OR LESS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...RAN
LONG TERM...RAN
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
114 PM EDT THU MAY 21 2015
.SYNOPSIS...
A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR SOUTHEAST NORTH
CAROLINA INTO THE LOCAL COASTAL WATERS NORTH OF CAPE FEAR THROUGH
8 PM. ANY SEVERE THUNDERSTORMS WILL TRACK EAST AS TROUGH OF LOW
PRESSURE TRACKS EAST TOWARD THE COAST THROUGH THIS AFTERNOON. AS
LOW PRESSURE DEPARTS WELL TO OUR NORTHEAST...IT WILL DRAG A COLD
FRONT ACROSS THE AREA LATE IN THE DAY AND THIS EVENING. HIGH
PRESSURE WILL BUILD ACROSS THE EASTERN CAROLINAS FRIDAY AND
SATURDAY. THE HIGH WILL MOVE OFFSHORE SUNDAY...BRINGING A RETURN
TO HIGHER HUMIDITY BY TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM THURSDAY...SEVERE THUNDERSTORM WATCH 193 HAS BEEN
ISSUED FOR SOUTHEAST NC THROUGH 8 PM. APPROACH OF A WAVE OF LOW
PRESSURE AT THE SURFACE ALONG WITH SHORTWAVE IN THE MID LEVELS
WILL COMBINE WITH HEATING OF THE DAY AND MOISTURE RICH AIR TO TO
CONTINUE TO TRIGGER SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN
CAROLINAS LATE MORNING. THESE THUNDERSTORMS MAY CONTAIN DAMAGING
WINDS AND HAIL. CAN NOT RULE OUT AN ISOLATED TORNADO. A FAIRLY
DECENT LINE SEGMENT HAS DEVELOPED JUST WEST OF ILM CWA INTO
MARLBORO AND DARLINGTON COUNTIES EARLY THIS AFTERNOON ALIGNED WITH
BEST CONVERGENCE ALONG SFC TROUGH AS DRY AIR PUNCHES IN FROM THE
WEST AS EVIDENT ON WATER VAPOR IMAGERY.
THE MID LEVEL SHORTWAVE WILL MOVE ACROSS THE FORECAST AREA NEAR
THE TIME OF PEAK HEATING WITH THE UPPER JET IN A FAVORABLE
POSITION FOR ORGANIZED STORMS TO DEVELOP. THE BEST MOISTURE WILL
BE LOCATED TO THE SOUTH OF WARM FRONT AND CLOSER TO THE COAST WITH
DEWPOINTS UP AROUND 70. THE MARGINAL AREA OUTLINED BY SPC LINES UP
WITH BEST CONVECTIVE PARAMETERS...WITH ML CAPE CLOSE TO 1200 J/KG
AND BULK SHEAR VALUES WILL REACH AROUND 35 KT...HIGHEST ACROSS
SOUTHEAST NORTH CAROLINA. DCAPE WILL BE ABOVE 500 AS SW-WESTERLY
FLOW ALOFT WILL PROMOTE DRYING THROUGH THE MID LEVELS AND A
GREATER INVERTED V TYPE PROFILE THROUGH THE AFTERNOON. THE
DOWNSLOPING WESTERLY FLOW WILL ALSO PRODUCE MORE SUBSIDENCE WHICH
COULD ACT AGAINST CONVECTIVE DEVELOPMENT....BUT THIS WESTERLY
FLOW ALOFT WILL ALSO ALLOW FOR GREATER VERTICAL SHEAR AND MAY SEE
A FEW LINE SEGMENTS DEVELOP WITH POTENTIAL FOR DAMAGING
WIND. CAN NOT RULE OUT SOME HAIL OR BRIEF TORNADO...AS WELL. EXPECT
THIS TO AFFECT MAINLY THE NORTHERN TIER COUNTIES OF LOCAL CWA AND
MAINLY OVER EASTERN NORTH CAROLINA. KEPT POPS HIGHEST IN THIS
AREA. POPS WILL TREND DOWN TO CHANCE AND SLIGHT CHANCE ACROSS MOST
OF SOUTH CAROLINA. ANY STORMS AND CONVECTIVE DEBRIS CLOUDS WILL
MOVE SWIFTLY OFF TO THE EAST IN A 25 TO 35 KT WESTERLY STEERING
FLOW.
THE LINGERING WEAK FRONT WHICH HAS PUSHED BACK NORTH AS A WARM
FRONT WILL GET NUDGED EAST THROUGH THE DAY AS AS SFC LOW SWEEPS
ACROSS THE CAROLINAS AND OFF SHORE BY THIS EVENING. THE BEST CHC
OF MORE WIDESPREAD CONVECTION WILL BE ALONG AND N OF THE LOW
PRESSURE TRACK....PROVIDING THE NECESSARY LIFT FOR SHOWERS AND
THUNDERSTORMS. THEREFORE AS LOW TRACKS OFF THE COAST BY EARLY THIS
EVENING ANY CONVECTION WILL COME TO AN END.
A TRAILING COLD FRONT SHOULD SWEEP OFFSHORE AS LOW PRESSURE PULLS
OFF TO THE NE INTO THIS EVE...BRINGING DRIER AND MORE STABLE AIR
INTO THE AREA OVERNIGHT. WE WILL BE ON THE SOUTHERN PERIPHERY OF
ANOTHER WEAK MID-LEVEL TROUGH PIVOTING AROUND UPPER LOW ACROSS
SOUTHEAST CANADA. THIS MAY BRING AN UPTICK IN CLOUD COVER
OVERNIGHT...BUT NO RAINFALL.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...FAIR WEATHER WITH LOW RELATIVE HUMIDITY
IS EXPECTED THROUGH THE PERIOD AS HIGH PRESSURE SETTLES OVER THE
AREA. MAX TEMPERATURES EACH DAY WILL BE IN THE UPPER 70S TO
LOWER 80S...THOUGH SATURDAY SHOULD BE A DEGREE OR TWO WARMER THAN
FRIDAY. MINS FRIDAY NIGHT WILL FALL TO THE UPPER 50S TO LOWER 60S
AND MODERATE SLIGHTLY TO THE LOW TO MID 60S SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 300 AM THURSDAY...SURFACE HIGH PRESSURE WILL REMAIN OVER THE
AREA THROUGH THE PERIOD AS A HIGH PRESSURE RIDGE BUILDS IN ALOFT
BY THE MIDDLE OF THE WEEK. THE RESULT WILL BE FAIR WEATHER THROUGH
THE PERIOD BUT TEMPERATURES AND HUMIDITY WILL BE ON THE RISE. MAX
TEMPERATURES WILL MODERATE FROM LOW TO MID 80S SUNDAY TO MID 80S TO
AROUND 90 BY WEDNESDAY. MIN TEMPERATURES WILL ALSO BE ON THE RISE
THROUGH THE PERIOD...GOING FROM LOW TO MID 60S SUNDAY NIGHT TO UPPER
60S TO LOWER 70S BY WEDNESDAY NIGHT. DRY WEATHER IS EXPECTED
THROUGH MOST OF THE PERIOD...THOUGH A SLIGHTLY WEAKER UPPER RIDGE
WEDNESDAY COULD ALLOW FOR THE DEVELOPMENT OF ISOLATED THUNDERSTORMS
DURING THE AFTERNOON AND EVENING.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
PATCHY DENSE FOG SHOULD DISSIPATE FAIRLY RAPIDLY THIS MORNING AS
SOUTHWEST FLOW COMMENCES AHEAD OF LOW PRESSURE CENTERED JUST WEST OF
THE REGION. THIS SOUTHWEST FLOW WILL INCREASE THIS MORNING...WITH
GUSTS OVER 20 KTS EXPECTED BY LATE MORNING. THE HRRR MODEL CONTINUES
TO SHOW MODERATE CONVECTION OVER OUR NORTHERN COUNTIES. OUR NORTHERN
COASTAL COUNTIES STAND THE BEST CHANCE FOR SHOWERS AS THEY WILL
LIKELY HEAT UP THE MOST AND WILL HAVE THE LOW LEVEL CONVERGENCE OF
THE SEA BREEZE BOUNDARY. THE LOW AND ASSOCIATED CONVECTION WILL EXIT
THE AREA THIS EVENING...WITH NORTHERLY WINDS ON THE BACK SIDE.
EXTENDED OUTLOOK...VFR. FOG POSSIBLE MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM THURSDAY...SEVERE THUNDERSTORM WATCH 193 HAS BEEN
ISSUED FOR SOUTHEAST NC INTO THE LOCAL COASTAL WATERS NORTH OF
CAPE FEAR THROUGH 8 PM. SW WINDS 15 TO 20 KT AHEAD OF A COLD
FRONT...WILL SHIFT TO THE NW THIS EVE...AND THEN N OVERNIGHT AS
LOW PRESSURE TO OUR N MOVES FURTHER AWAY. A DEVELOPING NORTHERLY
SURGE WILL INCREASE WINDS TO AROUND 20 KT LATE TONIGHT AND WE WILL
BE NEAR SMALL CRAFT SHOULD EXERCISE CAUTION LEVELS. SEAS WILL BE 2
TO 4 FT TODAY WITH SOME 5 FT SEAS ACROSS THE OUTERMOST WATERS LATE
TONIGHT. WINDS AND SEAS WILL BE LOCALLY HIGHER IN SCATTERED TO
NUMEROUS THUNDERSTORMS TODAY AND THIS EVE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...LOOKS LIKE A QUIET PERIOD ON THE WATERS WITH
NE WINDS OF 10 TO 15 KT FRIDAY INTO SATURDAY THAT WILL BECOME MORE
EASTERLY BY SATURDAY NIGHT. SEAS OF 3 FEET OR LESS ARE EXPECTED
THROUGH THE PERIOD.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SUMMER LIKE CONDITIONS WILL CONTINUE ON THE
WATERS WITH SE WINDS OF 10 TO 15 KT EXPECTED THROUGH THE FORECAST
PERIOD WITH SEAS OF 3 FT OR LESS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...RAN
LONG TERM...RAN
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1039 AM EDT THU MAY 21 2015
.SYNOPSIS...
STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE TODAY. THE HIGHEST
RISK FOR SEVERE WEATHER WILL BE ACROSS SOUTHEAST NORTH CAROLINA.
LOW PRESSURE WILL MOVE ALONG A WEAK FRONT TODAY. AS LOW PRESSURE
DEPARTS WELL TO OUR NORTHEAST...IT WILL DRAG A COLD FRONT ACROSS
THE AREA LATE IN THE DAY AND THIS EVENING. HIGH PRESSURE WILL
BUILD ACROSS THE EASTERN CAROLINAS FRIDAY AND SATURDAY. THE HIGH
WILL MOVE OFFSHORE SUNDAY...BRINGING A RETURN TO HIGHER HUMIDITY
BY TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM THURSDAY...EASTERN NC REMAINS IN A MARGINAL RISK
FOR SEVERE WEATHER. CONVECTION WAS LOCATED OFFSHORE THIS MORNING
AND ANY FOG LIFTED...BUT STRATUS IS STILL BREAKING UP WITH A
FAIRLY DECENT BLANKET OF STRATOCU OVER NORTH CAROLINA. EXPECT
STRATOCU TO DISSIPATE SOME WITH A GREATER AMOUNT OF SUNSHINE
MIXING IN. APPROACH OF A WAVE OF LOW PRESSURE AT THE SURFACE ALONG
WITH SHORTWAVE IN THE MID LEVELS WILL COMBINE WITH HEATING OF THE
DAY AND MOISTURE RICH AIR TO BEGIN TO TRIGGER SHOWERS AND
THUNDERSTORMS ACROSS THE EASTERN CAROLINAS LATE MORNING.
THE MID LEVEL SHORTWAVE WILL MOVE ACROSS THE FORECAST AREA NEAR
THE TIME OF PEAK HEATING WITH THE UPPER JET IN A FAVORABLE
POSITION FOR ORGANIZED STORMS TO DEVELOP. THE BEST MOISTURE WILL
BE LOCATED TO THE SOUTH OF WARM FRONT AND CLOSER TO THE COAST WITH
DEWPOINTS UP AROUND 70. THE MARGINAL AREA OUTLINED BY SPC LINES UP
WITH BEST CONVECTIVE PARAMETERS...WITH ML CAPE CLOSE TO 1200 J/KG
AND BULK SHEAR VALUES WILL REACH AROUND 35 KT...HIGHEST ACROSS
SOUTHEAST NORTH CAROLINA. DCAPE WILL BE ABOVE 500 AS SW-WESTERLY
FLOW ALOFT WILL PROMOTE DRYING THROUGH THE MID LEVELS AND A
GREATER INVERTED V TYPE PROFILE THROUGH THE AFTERNOON. THE
DOWNSLOPING WESTERLY FLOW WILL ALSO PRODUCE MORE SUBSIDENCE WHICH
COULD ACT AGAINST CONVECTIVE DEVELOPMENT....BUT THIS WESTERLY
FLOW ALOFT WILL ALSO ALLOW FOR GREATER VERTICAL SHEAR AND MAY SEE
A FEW LINE SEGMENTS DEVELOP WITH POTENTIAL FOR DAMAGING
WIND. CAN NOT RULE OUT SOME HAIL OR BRIEF TORNADO...AS WELL. EXPECT
THIS TO AFFECT MAINLY THE NORTHERN TIER COUNTIES OF LOCAL CWA AND
MAINLY OVER EASTERN NORTH CAROLINA. KEPT POPS HIGHEST IN THIS
AREA. POPS WILL TREND DOWN TO CHANCE AND SLIGHT CHANCE ACROSS MOST
OF SOUTH CAROLINA. ANY STORMS AND CONVECTIVE DEBRIS CLOUDS WILL
MOVE SWIFTLY OFF TO THE EAST IN A 25 TO 35 KT WESTERLY STEERING
FLOW.
THE LINGERING WEAK FRONT WHICH HAS PUSHED BACK NORTH AS A WARM
FRONT WILL GET NUDGED EAST THROUGH THE DAY AS AS SFC LOW SWEEPS
ACROSS THE CAROLINAS AND OFF SHORE BY THIS EVENING. THE BEST CHC
OF MORE WIDESPREAD CONVECTION WILL BE ALONG AND N OF THE LOW
PRESSURE TRACK....PROVIDING THE NECESSARY LIFT FOR SHOWERS AND
THUNDERSTORMS. THEREFORE AS LOW TRACKS OFF THE COAST BY EARLY THIS
EVENING ANY CONVECTION WILL COME TO AN END.
A TRAILING COLD FRONT SHOULD SWEEP OFFSHORE AS LOW PRESSURE PULLS
OFF TO THE NE INTO THIS EVE...BRINGING DRIER AND MORE STABLE AIR
INTO THE AREA OVERNIGHT. WE WILL BE ON THE SOUTHERN PERIPHERY OF
ANOTHER WEAK MID-LEVEL TROUGH PIVOTING AROUND UPPER LOW ACROSS
SOUTHEAST CANADA. THIS MAY BRING AN UPTICK IN CLOUD COVER
OVERNIGHT...BUT NO RAINFALL.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...FAIR WEATHER WITH LOW RELATIVE HUMIDITY
IS EXPECTED THROUGH THE PERIOD AS HIGH PRESSURE SETTLES OVER THE
AREA. MAX TEMPERATURES EACH DAY WILL BE IN THE UPPER 70S TO
LOWER 80S...THOUGH SATURDAY SHOULD BE A DEGREE OR TWO WARMER THAN
FRIDAY. MINS FRIDAY NIGHT WILL FALL TO THE UPPER 50S TO LOWER 60S
AND MODERATE SLIGHTLY TO THE LOW TO MID 60S SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...SURFACE HIGH PRESSURE WILL REMAIN OVER THE
AREA THROUGH THE PERIOD AS A HIGH PRESSURE RIDGE BUILDS IN ALOFT
BY THE MIDDLE OF THE WEEK. THE RESULT WILL BE FAIR WEATHER THROUGH
THE PERIOD BUT TEMPERATURES AND HUMIDITY WILL BE ON THE RISE. MAX
TEMPERATURES WILL MODERATE FROM LOW TO MID 80S SUNDAY TO MID 80S TO
AROUND 90 BY WEDNESDAY. MIN TEMPERATURES WILL ALSO BE ON THE RISE
THROUGH THE PERIOD...GOING FROM LOW TO MID 60S SUNDAY NIGHT TO UPPER
60S TO LOWER 70S BY WEDNESDAY NIGHT. DRY WEATHER IS EXPECTED
THROUGH MOST OF THE PERIOD...THOUGH A SLIGHTLY WEAKER UPPER RIDGE
WEDNESDAY COULD ALLOW FOR THE DEVELOPMENT OF ISOLATED THUNDERSTORMS
DURING THE AFTERNOON AND EVENING.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
PATCHY DENSE FOG SHOULD DISSIPATE FAIRLY RAPIDLY THIS MORNING AS
SOUTHWEST FLOW COMMENCES AHEAD OF LOW PRESSURE CENTERED JUST WEST OF
THE REGION. THIS SOUTHWEST FLOW WILL INCREASE THIS MORNING...WITH
GUSTS OVER 20 KTS EXPECTED BY LATE MORNING. THE HRRR MODEL CONTINUES
TO SHOW MODERATE CONVECTION OVER OUR NORTHERN COUNTIES. OUR NORTHERN
COASTAL COUNTIES STAND THE BEST CHANCE FOR SHOWERS AS THEY WILL
LIKELY HEAT UP THE MOST AND WILL HAVE THE LOW LEVEL CONVERGENCE OF
THE SEA BREEZE BOUNDARY. THE LOW AND ASSOCIATED CONVECTION WILL EXIT
THE AREA THIS EVENING...WITH NORTHERLY WINDS ON THE BACK SIDE.
EXTENDED OUTLOOK...VFR. FOG POSSIBLE MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM THURSDAY...SW WINDS 15 TO 20 KT AHEAD OF A COLD
FRONT...WILL SHIFT TO THE NW THIS EVE...AND THEN N OVERNIGHT AS
LOW PRESSURE TO OUR N MOVES FURTHER AWAY. A DEVELOPING NORTHERLY
SURGE WILL INCREASE WINDS TO AROUND 20 KT LATE TONIGHT AND WE WILL
BE NEAR SMALL CRAFT SHOULD EXERCISE CAUTION LEVELS. SEAS WILL BE 2
TO 4 FT TODAY WITH SOME 5 FT SEAS ACROSS THE OUTERMOST WATERS LATE
TONIGHT. WINDS AND SEAS WILL BE LOCALLY HIGHER IN SCATTERED TO
NUMEROUS THUNDERSTORMS TODAY AND THIS EVE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...LOOKS LIKE A QUIET PERIOD ON THE WATERS WITH
NE WINDS OF 10 TO 15 KT FRIDAY INTO SATURDAY THAT WILL BECOME MORE
EASTERLY BY SATURDAY NIGHT. SEAS OF 3 FEET OR LESS ARE EXPECTED
THROUGH THE PERIOD.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SUMMER LIKE CONDITIONS WILL CONTINUE ON THE
WATERS WITH SE WINDS OF 10 TO 15 KT EXPECTED THROUGH THE FORECAST
PERIOD WITH SEAS OF 3 FT OR LESS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...RAN
LONG TERM...RAN
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
650 AM EDT THU MAY 21 2015
.SYNOPSIS...
STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE TODAY. THE HIGHEST
RISK FOR SEVERE WEATHER WILL BE ACROSS SOUTHEAST NORTH CAROLINA.
LOW PRESSURE WILL MOVE ALONG A WEAK FRONT TODAY. AS LOW PRESSURE
DEPARTS WELL TO OUR NORTHEAST...IT WILL DRAG A COLD FRONT ACROSS
THE AREA LATE IN THE DAY AND THIS EVENING. HIGH PRESSURE WILL
BUILD ACROSS THE EASTERN CAROLINAS FRIDAY AND SATURDAY. THE HIGH
WILL MOVE OFFSHORE SUNDAY...BRINGING A RETURN TO HIGHER HUMIDITY
BY TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM THURSDAY...CONVECTION WAS LOCATED OFFSHORE THIS
MORNING. VISIBILITIES WERE AS LOW AS A HALF MILE IN PATCHY FOG
EARLY THIS MORNING. ANY FOG WILL LIFT AND DISSIPATE THROUGH 730
AM. THE CONVECTION WAS LOCATED OFFSHORE THIS MORNING. APPROACH OF
A SURFACE WAVE AND MID-LEVEL DISTURBANCE WILL BEGIN TO TRIGGER
SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN CAROLINAS LATE
MORNING WITH THE HIGHEST CONCENTRATION OF THUNDERSTORMS EXPECTED
ACROSS EASTERN NORTH CAROLINA THIS AFTERNOON.
A WEAK FRONT WILL BE DRAPED ACROSS THE AREA TODAY. A WAVE OF LOW
PRESSURE AT THE SURFACE WILL MOVE ALONG THE FRONT...PROVIDING THE
NECESSARY LIFT FOR SHOWERS AND THUNDERSTORMS...ESPECIALLY ALONG
AND N OF THE LOW PRESSURE TRACK. A MID-LEVEL SHORTWAVE WILL MOVE
ACROSS THE FORECAST AREA NEAR THE TIME OF PEAK HEATING WITH THE
UPPER JET IN A FAVORABLE POSITION FOR ORGANIZED STORMS TO DEVELOP.
INSTABILITY WILL BE GROWING THROUGH THE MORNING AND EARLY
AFTERNOON...PEAKING AROUND 2500 J/KG AND POSSIBLY AS HIGH AS 3000
J/KG DURING THE AFTERNOON. BULK SHEAR VALUES WILL REACH AROUND 35
KT...HIGHEST ACROSS SOUTHEAST NORTH CAROLINA.
THUS...SEVERE WEATHER IS CERTAINLY POSSIBLE WITH THE HIGHEST
PROBABILITY ALONG AND NORTH OF THE LOW TRACK ACROSS SOUTHEAST NORTH
CAROLINA AND POINTS NORTH. WILL CARRY HIGHEST POPS...LIKELY TO
CATEGORICAL...IN THESE AREAS AS WE DO EXPECT THE CONVECTION TO
BECOME RATHER WELL ORGANIZED. WILL TREND POPS DOWN TO CHANCE AND
SLIGHT CHANCE ACROSS MOST OF SOUTH CAROLINA.
WHILE STRONGEST WINDS THIS AFTERNOON WILL BE N OF THE AREA...WE ARE
EXPECTING MID LEVEL WINDS TO REACH AROUND 40 KT. THE DIRECTION WILL
BE WESTERLY WHICH TENDS TO BE A DRYING AND MORE SUBSIDENT FLOW FOR
THE EASTERN CAROLINAS. THE MODEL SOUNDINGS ALSO SHOW THE DEVELOPMENT
OF INVERTED V SOUNDINGS...WHICH SIGNALS THE POTENTIAL FOR STRONG TO
PERHAPS DAMAGING WIND GUSTS AT THE SURFACE IN THE MORE PERSISTENT
STORMS.
A COLD FRONT SHOULD SWEEP OFFSHORE AS LOW PRESSURE PULLS OFF TO THE
NE LATE DAY AND THIS EVE...BRINGING AN END TO THE SHOWERS AND
THUNDERSTORMS AS DRIER AND MORE STABLE AIR REACHES THE AREA
OVERNIGHT. WE WILL BE ON THE SOUTHERN PERIPHERY OF ANOTHER WEAK
MID-LEVEL TROUGH PIVOTING AROUND UPPER LOW ACROSS SOUTHEAST
CANADA. THIS MAY BRING AN UPTICK IN CLOUD COVER OVERNIGHT...BUT
NO RAINFALL.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM THURSDAY...FAIR WEATHER WITH LOW RELATIVE HUMIDITY
IS EXPECTED THROUGH THE PERIOD AS HIGH PRESSURE SETTLES OVER THE
AREA. MAX TEMPERATURES EACH DAY WILL BE IN THE UPPER 70S TO
LOWER 80S...THOUGH SATURDAY SHOULD BE A DEGREE OR TWO WARMER THAN
FRIDAY. MINS FRIDAY NIGHT WILL FALL TO THE UPPER 50S TO LOWER 60S
AND MODERATE SLIGHTLY TO THE LOW TO MID 60S SATURDAY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...SURFACE HIGH PRESSURE WILL REMAIN OVER THE
AREA THROUGH THE PERIOD AS A HIGH PRESSURE RIDGE BUILDS IN ALOFT
BY THE MIDDLE OF THE WEEK. THE RESULT WILL BE FAIR WEATHER THROUGH
THE PERIOD BUT TEMPERATURES AND HUMIDITY WILL BE ON THE RISE. MAX
TEMPERATURES WILL MODERATE FROM LOW TO MID 80S SUNDAY TO MID 80S TO
AROUND 90 BY WEDNESDAY. MIN TEMPERATURES WILL ALSO BE ON THE RISE
THROUGH THE PERIOD...GOING FROM LOW TO MID 60S SUNDAY NIGHT TO UPPER
60S TO LOWER 70S BY WEDNESDAY NIGHT. DRY WEATHER IS EXPECTED
THROUGH MOST OF THE PERIOD...THOUGH A SLIGHTLY WEAKER UPPER RIDGE
WEDNESDAY COULD ALLOW FOR THE DEVELOPMENT OF ISOLATED THUNDERSTORMS
DURING THE AFTERNOON AND EVENING.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
PATCHY DENSE FOG SHOULD DISSIPATE FAIRLY RAPIDLY THIS MORNING AS
SOUTHWEST FLOW COMMENCES AHEAD OF LOW PRESSURE CENTERED JUST WEST OF
THE REGION. THIS SOUTHWEST FLOW WILL INCREASE THIS MORNING...WITH
GUSTS OVER 20 KTS EXPECTED BY LATE MORNING. THE HRRR MODEL CONTINUES
TO SHOW MODERATE CONVECTION OVER OUR NORTHERN COUNTIES. OUR NORTHERN
COASTAL COUNTIES STAND THE BEST CHANCE FOR SHOWERS AS THEY WILL
LIKELY HEAT UP THE MOST AND WILL HAVE THE LOW LEVEL CONVERGENCE OF
THE SEA BREEZE BOUNDARY. THE LOW AND ASSOCIATED CONVECTION WILL EXIT
THE AREA THIS EVENING...WITH NORTHERLY WINDS ON THE BACK SIDE.
EXTENDED OUTLOOK...VFR. FOG POSSIBLE MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM THURSDAY...SW WINDS 15 TO 20 KT AHEAD OF A COLD
FRONT...WILL SHIFT TO THE NW THIS EVE...AND THEN N OVERNIGHT AS
LOW PRESSURE TO OUR N MOVES FURTHER AWAY. A DEVELOPING NORTHERLY
SURGE WILL INCREASE WINDS TO AROUND 20 KT LATE TONIGHT AND WE WILL
BE NEAR SMALL CRAFT SHOULD EXERCISE CAUTION LEVELS. SEAS WILL BE 2
TO 4 FT TODAY WITH SOME 5 FT SEAS ACROSS THE OUTERMOST WATERS LATE
TONIGHT. WINDS AND SEAS WILL BE LOCALLY HIGHER IN SCATTERED TO
NUMEROUS THUNDERSTORMS TODAY AND THIS EVE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...LOOKS LIKE A QUIET PERIOD ON THE WATERS WITH
NE WINDS OF 10 TO 15 KT FRIDAY INTO SATURDAY THAT WILL BECOME MORE
EASTERLY BY SATURDAY NIGHT. SEAS OF 3 FEET OR LESS ARE EXPECTED
THROUGH THE PERIOD.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SUMMER LIKE CONDITIONS WILL CONTINUE ON THE
WATERS WITH SE WINDS OF 10 TO 15 KT EXPECTED THROUGH THE FORECAST
PERIOD WITH SEAS OF 3 FT OR LESS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD
SHORT TERM...RAN
LONG TERM...RAN
AVIATION...43
AREA FORECAST DISCUSSION
NWS TULSA OK
1137 PM CDT WED MAY 20 2015
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
MVFR TO IFR CONDITIONS TONIGHT WILL GIVE WAY TO VFR CONDITIONS
ON THURSDAY AT ALL AREA TAF SITES.
&&
.PREV DISCUSSION... /ISSUED 925 PM CDT WED MAY 20 2015/
..UPDATE...
DISCUSSION...
CLOUDY AND COOL POST-FRONTAL CONDITIONS ACROSS
THE FORECAST AREA THROUGH TONIGHT. AREA RADARS
ARE SHOWING ISOLATED SHOWERS/THUNDERSTORMS
ACROSS SRN OK...AND HAVE UPPED POPS FOR PARTS
OF SE OK AFTER 06Z AND INTO THURSDAY MORNING
BASED ON LATEST HRRR OUTPUT. ALSO BUMPED UP
CLOUD COVER AS WELL.
STILL EXPECTING SEVERAL ROUNDS OF POTENTIALLY
HEAVY PRECIPITATION OVER THE NEXT SEVERAL
DAYS...THE FIRST COMING ON FRIDAY. CONTEMPLATED
ISSUING A FLASH FLOOD WATCH...BUT WILL DEFER
TO THE NEXT SHIFT FOR NOW.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...10
AREA FORECAST DISCUSSION
NWS PORTLAND
233 PM PDT THU MAY 21 2015
.SYNOPSIS...A BROAD UPPER LEVEL TROUGH OVER THE EASTERN PACIFIC AND
ALONG THE WEST COAST WILL CONTINUE TO BRING A THREAT OF SHOWERS AND
THUNDERSTORMS TO THE CASCADES THROUGH THIS EVENING. THE MARINE LAYER
IS EXPECTED TO DEEPEN TONIGHT AND FRIDAY. THIS WILL PUSH THE
CONVECTIVE THREAT EAST OF THE CASCADES. STRONG ONSHORE FLOW WILL
CONTINUE THROUGH SATURDAY...THEN WEAKEN A LITTLE SUNDAY. ANOTHER
UPPER LOW LOOKS LIKE IT WILL APPROACH THE AREA EARLY NEXT WEEK...
BRINGING CONTINUED SHOWER CHANCES.
&&
.SHORT TERM...TONIGHT THROUGH SUNDAY...CONVECTION ALREADY FIRING
EARLY THIS AFTERNOON IN THE HIGHER CASCADES. A FEW LIGHTNING STRIKES
NOTED IN NE COWLITZ COUNTY IN THE WA CASCADES AND ALSO MCKENZIE PASS
IN THE LANE COUNTY CASCADES. THE 02 HR FCST OFF THE 18Z HRRR RUN
DEPICTS THE GENERAL CONVECTIVITY REASONABLY WELL. CELLS ARE DRIFTING
EAST TO WEST...BUT THE GENERAL TREND HAS BEEN FOR THEM TO WEAKEN UPON
REACHING THE LOWER CASCADE FOOTHILLS.
THE OVERALL LARGE-SCALE PATTERN THROUGH TONIGHT CONSISTS OF A BROAD
UPPER LOW CENTERED OFF THE CENTRAL CALIFORNIA COAST WITH MULTIPLE
SUBTLE SHORT-WAVES ROTATING AROUND IT. MEANWHILE...THERE IS A SECOND
LOW ALONG THE CENTRAL BRITISH COLUMBIA COAST. THIS WILL BE THE ONE
THAT BECOMES THE MAIN PLAYER LATER IN THE WEEKEND. VERY MOIST AIR
MASS IN PLACE AS EVIDENCED BY THE 1.11 PRECIPITABLE WATER FROM
THE 12Z KSLE SOUNDING. THIS IS WELL ABOVE THE 90TH PERCENTILE VALUE
FOR THIS TIME OF YEAR...OR ABOUT 2 STANDARD DEVIATIONS ABOVE AVERAGE.
THE SOUNDING ALSO SHOWED EAST FLOW FROM AROUND 850 MB THROUGH 300 MB.
THE 18Z HRRR SHOWS QPF SPREADING INTO THE WILLAMETTE VALLEY THIS
EVENING...GENERALLY AFTER 01Z FRI. ALTHOUGH MODEL SOUNDINGS FOR THE
WILLAMETTE VALLEY SHOW IMPRESSIVE CONVECTIVE POTENTIAL...NOT
EXPECTING MUCH IN THE WAY OF THUNDERSTORMS WEST OF THE CASCADE
FOOTHILLS. MODEL SOUNDINGS...ESPECIALLY THE NAM...ARE TOO HIGH WITH
THE SFC DEW POINTS. AS AN EXAMPLE...THE NAM SOUNDING FOR KPDX GIVES A
DEW POINT OF 62-65 DEG 00Z FRI...WHICH TRANSLATES TO NEARLY 2500 J/KG
SFC-BASED CAPE. THE GFS IS NOT AS EXTREME...BUT STILL INDICATES
SURFACE DEW POINTS NEAR 60.
THE SPC STORM-SCALE ENSEMBLE OF OPPORTUNITY...SSEO...FOCUSES
REFLECTIVITY VALUES OVER SW WA CASCADES AND FOOTHILLS INTO THE N
WILLAMETTE VALLEY 00Z TO 03Z FRI. IT ALSO INDICATES A 70 PCT OR
GREATER PROBABILITY OF 40 DBZ ECHOES OR GREATER. MODIFIED FORECAST
SOUNDING VALID 00Z FRI WITH A DEW POINT CLOSER TO 50 DEG F AND
SLIGHTLY COOLER SFC TEMP YIELDS A MORE REALISTIC CAPE OF ABOUT 900
J/KG... MIXED LAYER CAPE OF 675 J/KG AND LI OF -3C. THE COASTAL ZONES
HAVE THE LOWEST POPS THROUGH THIS EVENING. BY 06Z FRI THE BULK OF THE
FORECAST AREA WILL RESIDE IN A COL AREA AS THE UPPER LOW AND
ASSOCIATED EAST FLOW SINK SOUTH INTO CALIFORNIA AND NEVADA.
THE HI-RES WRF-ARW AND A MODEL CROSS-SECTION FROM KAST-KDLS SHOW A
FAIRLY SUBSTANTIAL MARINE LAYER BY 12Z FRI...DUE TO ANOTHER SYSTEM
DROPPING SOUTH ALONG THE BRITISH COLUMBIA COAST TO THE SOUTH
WASHINGTON AND NORTH OREGON COAST. THE WRF-ARW INDICATES AFTERNOON
CLEARING...AS DO FCST MODEL SOUNDINGS. THE MAIN CHANGE FRI WILL BE A
CHANGE IN FLOW ALOFT FROM THE WEAK EAST OF THE PAST COUPLE DAYS TO
MORE NW-N. THIS RESULTS IN A MORE STABLE AIR MASS...PUSHING THE
THUNDERSTORM THREAT FRI EAST OF THE CASCADES.
12Z MODEL RUNS HAVE AN UPPER TROUGH EXTENDING FROM VANCOUVER ISLAND
TO THE FAR N OREGON COAST 12Z SAT. GFS MODEL SOUNDINGS SUGGEST MARINE
LAYER TOPS TO NEARLY 5000 FT SAT MORNING. HAVE ADDED A MENTION OF
DRIZZLE SAT MORNING DUE TO THE FCST DEPTH OF THE MARINE LAYER. GOING
WITH SLIGHT CHANCE TO CHANCE POPS SAT AFTERNOON IN THE S WA AND FAR N
OREGON CASCADES...CLOSEST TO THE COL AREA. LEFT OUT ANY MENTION OF
THUNDERSTORMS. MODELS STILL SHOWING LARGE DIFFERENCES SUN AND BEYOND.
IF THE ECMWF IS CORRECT...THERE WOULD BE STRONGER ONSHORE FLOW SUN
WITH LESS AFTERNOON SUN. THE GFS AND NAM HAVE LESS ONSHORE FLOW. IN
ANY EVENT...GENERAL CONDITIONS LOOK STABLE...WITH ANY SHOWER THREAT
CONFINED TO NRN PART OF S WA CASCADE ZONE.
WEISHAAR
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...GFS AND ECMWF BOTH SHOW
AN UPPER LEVEL LOW OR TROUGH SITTING OVER OREGON AND WASHINGTON
THROUGH TUE. MAIN MODEL DIFFERNCE IS THAT THE GFS MAINTAINS A CLOSED
FEATURE...KEEPING IT OVER SW WA...WHILE THE ECMWF HAS MORE OF AN OPEN
TROUGH A LITTLE MORE EAST THAN THE GFS. REGARDLESS OF WHICH MODEL
VERIFIES BEST...THE MAIN SENSIBLE WEATHER FOR THE CWA WOULD BE
CONTINUED ONSHORE LOW-LEVEL FLOW WITH THE BEST THREAT OF SHOWERS...
ALBEIT SMALL...OVER THE CASCADES. THE GFS HOLDS THE UPPER LOW
SOMEWHERE OVER SE WA WED...WHILE THE ECMWF HAS A MORE PRORESSIVE NWLY
FLOW ALOFT. HAVE GONE WITH SLIGHT CHANCE POPS FOR THE CASCADES
WED...BUT IF THE GFS IS MORE RIGHT...THEN IT WOULD BE DRY. TOO MUCH
UNCERTAINTY TO TOTALLY DISREGARD ANY PRECIP THREAT. WEISHAAR
&&
.AVIATION...SCATTERED SHOWERS OVER THE CASCADES WILL CONTINUE TO
DRIFT WEST THIS AFTERNOON/EVENING. ISOLATED THUNDERSTORMS HAVE
BEGUN TO FORM OVER THE LINN AND LANE COUNTY CASCADES. EXPECT THE
THREAT FOR LIGHTNING TO INCREASE INTO THIS EVENING. THESE SHOWERS
CONTINUE TO BRING A MIXTURE OF VFR TO MVFR CIGS TO THE INLAND
VALLEY...WITH BRIEF PERIODS OF REDUCED FLIGHT RULES UNDER HEAVIER
SHOWERS. CONDITIONS INLAND WILL ONCE AGAIN DETERIORATE TOWARDS
MVFR AFTER 06Z. MARINE STRATUS WILL FILTER INLAND LATE TONIGHT.
THE COAST CONTINUES TO REMAIN SOCKED IN UNDER WEAK ONSHORE FLOW.
IFR CIGS HAVE RAISED A FEW HUNDRED FEET AND WILL CONTINUE TO
RISE THIS AFTERNOON...WITH MVFR CIGS POSSIBLE FOR A FEW HOURS.
HOWEVER...ANY IMPROVEMENTS WILL BE SHORT LIVED WITH CIGS LOWERING
TOWARDS IFR THIS EVENING AS MARINE STRATUS RETURNS.
KPDX AND APPROACHES...CONDITIONS WILL REMAIN MOSTLY VFR THIS
AFTERNOON AND EVENING. SCATTERED SHOWERS WILL CONTINUE TO DRIFT
WEST AND COULD IMPACT THE TERMINAL WITH PERIODS OF REDUCED FLIGHT
RULES UNDER HEAVIER SHOWERS. CONDITIONS DETERIORATE TOWARDS MVFR
AFTER 06Z. MARINE STRATUS WILL FILTER IN AGAIN LATE TONIGHT. /64
&&
.MARINE...A RATHER PERSISTENT WEATHER PATTERN WITH HIGH PRES
CENTERED ABOUT 600 NM OFFSHORE WILL CONTINUE THROUGH THE REST OF
THE WEEK AND THE WEEKEND. THIS WILL KEEP WINDS OUT OF THE NW BUT
GENERALLY BELOW 20 KT. A FRESH SWELL OF 5 TO 6 FT WILL ALSO
CONTINUE OUT OF THE WNW.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND
916 AM PDT THU MAY 21 2015
.SYNOPSIS...A BROAD UPPER LEVEL TROUGH OVER THE EASTERN PACIFIC AND
ALONG THE WEST COAST WILL CONTINUE TO BRING A THREAT OF SHOWERS AND
THUNDERSTORMS TO THE CASCADES THROUGH THIS EVENING. THE MARINE LAYER
IS EXPECTED TO DEEPEN TONIGHT AND FRIDAY. THIS WILL PUSH THE
CONVECTIVE THREAT EAST OF THE CASCADES. THE STRONGER ONSHORE FLOW
WILL CONTINUE THROUGH THE WEEKEND WITH SOME THREAT OF SHOWERS.
ANOTHER UPPER LOW LOOKS LIKE IT WILL APPROACH THE AREA EARLY NEXT
WEEK...BRINGING CONTINUED SHOWER CHANCES.
&&
.SHORT TERM...MORNING VISIBLE SATELLITE IMAGERY SHOWS CONSIDERABLE
CLOUD COVER ACROSS THE AREA. KRTX DUAL-POL DOPPLER RADAR INDICATING
SOME SHOWER ACTIVITY ACROSS THE CENTRAL OREGON COAST RANGE AND
COAST...AS WELL AS THE NORTH AND CENTRAL OREGON CASCADES. VERY MOIST
AIR MASS IN PLACE AS EVIDENCED BY THE 1.11 PRECIPITABLE WATER FROM
THE 12Z KSLE SOUNDING. THIS IS WELL ABOVE THE 90TH PERCENTILE VALUE
FOR THIS TIME OF YEAR. THE SOUNDING ALSO SHOWED EAST FLOW FROM AROUND
850 MB THROUGH 300 MB.
THE MARINE LAYER THIS MORNING APPEARS TO BE MORE BROKEN...EXCEPT
ALONG THE COASTAL AREAS. THE HI-RES WRF-ARW MAINTAINS THE MARINE
LAYER THROUGH AT LEAST 18Z THEN SHOWS IT BREAKING UP IN SW WA AND THE
N OREGON COASTS RANGE BETWEEN 18Z AND 21Z. OBVIOUSLY...CLOUD COVER
WILL HAVE A BIG IMPACT ON THE ABILITY FOR PARCELS TO REACH THE
CONVECTIVE TEMPERATURE. THE 14Z HRRR SHOWS SHOWERS AND POSSIBLE
CONVECTION DEVELOPING OVER THE HIGHER CASCADES AS EARLY AS 18Z ...BUT
THE GREATER COVERAGE LOOKS TO OCCUR JUST AFTER 00Z FRI. THE SPC
STORM-SCALE ENSEMBLE OF OPPORTUNITY...SSEO...FOCUSES REFLECTIVITY
VALUES OVER SW WA CASCADES AND FOOTHILLS INTO THE N WILLAMETTE VALLEY
00Z TO 03Z FRI. IT ALSO INDICATES A 70 PCT OR GREATER PROBABILITY OF
40 DBZ ECHOES OR GREATER. NAM AND GFS FORECAST SOUNDING FOR A POINT
NEAR SANTIAM PASS SHOWS IMPRESSIVE CONVECTIVE PARAMETERS LATE THIS
AFTERNOON...WITH CAPES IN EXCESS OF 1500 J/KG...MIXED LAYER CAPES OF
750 J/KG AND LI OF -4 TO -6 DEG C. ALL OF THIS IS PREDICATED ON A SFC
DEW POINT OF CLOSE TO 55 DEG F AT 850 MB...WHICH IS A LITTLE
OVERDONE. MODIFIED FORECAST SOUNDING VALID 00Z FRI WITH A DEW POINT
CLOSER TO 50 DEG F AND SLIGHTLY COOLER SFC TEMP YIELDS A MORE
REALISTIC CAPE OF ABOUT 900 J/KG... MIXED LAYER CAPE OF 675 J/KG AND
LI OF -3C. MODIFIED SOUNDING ALSO SHOWED MINIMAL CIN SO IF THERE IS
ANY APPRECIABLE SUNSHINE CONVECTION SHOULD DEVELOP QUICKLY. HIGHEST
POPS THIS AFTERNOON AND THIS EVENING WILL BE OVER THE CASCADES AND
FOOTHILLS...BUT THE DEEP EAST FLOW WILL ALLOW ANY SHOWERS AND
THUNDERSTORMS THAT DEVELOP OVER THE CASCADES TO DRIFT INTO THE
WILLAMETTE VALLEY. THE COASTAL ZONES HAVE THE LOWEST POPS...ALTHOUGH
A CELL EARLY THIS MORNING DROPPED JUST OVER ONE-HALF INCH OF RAIN AT
KONP IN A SHORT TIME. BY 06Z FRI THE BULK OF THE FORECAST AREA WILL
RESIDE IN A COL AREA AS THE UPPER LOW AND ASSOCIATED EAST FLOW SINK
SOUTH INTO CALIFORNIA AND NEVADA.
THE MODELS SHOW ANOTHER SYSTEM DROPPING SOUTH ALONG THE BRITISH
COLUMBIA COAST TO THE SOUTH WASHINGTON AND NORTH OREGON COAST FRIDAY.
THIS WILL DEEPEN THE MARINE LAYER IN SOUTHWEST WASHINGTON AND
NORTHWEST OREGON...AND MAY MAKE IT DIFFICULT FOR THE LOW CLOUDS TO
CLEAR IN THE AFTERNOON. IN ADDITION...THE WINDS AT ALL LEVELS ARE
TURNING MORE WEST TO NORTHWESTERLY...AND THIS SHOULD PUSH MOST OF THE
THUNDERSTORMS EAST OF THE CASCADE CREST FRIDAY AFTERNOON AND EVENING.
IF ANY DO FORM...IT WILL BE BRIEFLY RIGHT AT THE CREST AND THEN THEY
WILL MOVE OFF INTO CENTRAL OREGON...BUT HAVE LEFT THUNDER OUT OF THE
FORECAST AT THIS TIME.
ON FRIDAY NIGHT AND SATURDAY...THE SYSTEM APPROACHING FROM THE
NORTHWEST MOVES ACROSS OUR AREA. THIS SHOULD MAINTAIN SUBSTANTIAL
ONSHORE FLOW. THE BIGGEST QUESTION IS WHETHER THE COLD POOL
ASSOCIATED WITH THE LOW WILL MOVE OVERHEAD...WHICH COULD TRIGGER SOME
SHOWERS OR EVEN SOME THUNDERSTORMS. THE MODELS HAVE SHOWN A VARIETY
OF SOLUTIONS. THE GFS HAS SUGGESTED AT TIMES THAT THE ABOVE SCENARIO
IS POSSIBLE. THE ECMWF AND CANADIAN MODELS HAVE BEEN SHEARING A LEAD
SHORT WAVE SOUTH ALONG THE COAST SATURDAY...WAITING UNTIL SUNDAY FOR
A TRAILING LOW TO COME OVERHEAD. WILL CONTINUE THE BROAD BRUSHED
CHANCE OF SHOWERS FOR NOW WITH MEDIOCRE CONFIDENCE IN ANY DETAILS AT
BEST. WEISHAAR
.LONG TERM...NO SIGNIFICANT CHANGES. PREVIOUS DISCUSSION FOLLOWS...
SATURDAY NIGHT THROUGH WEDNESDAY...MODELS HAVE AGAIN COME INTO
REASONABLE AGREEMENT THAT AN UPPER LOW WILL SLIDE ACROSS THE PACIFIC
NORTHWEST LATE SATURDAY INTO SUNDAY...THOUGH STILL PLENTY OF SPREAD
AMONG MODEL GUIDANCE AS TO IF THE LOW TRACKS MORE EASTWARD ACROSS THE
CASCADES OR MORE SOUTHWARD TOWARDS THE GREAT BASIN. REGARDLESS...
INTRODUCED SLIGHT CHANCE POPS FOR MOST OF THE AREASUNDAY. MAY END UP
SEEING SOME THUNDERSTORMS NEAR THE CASCADE CREST IF THE UPPER LOW
TRACKS OVERHEAD AND LINGERS. FLOW ALOFT LOOKS TO REMAIN RATHER WEAK
OR WEAKLY ONSHORE WITH CONTINUED POSSIBILITIES FOR SHOWERS IN THE
CASCADES. TEMPERATURES WILL REMAIN NEAR SEASONAL FOR THE FIRST HALF
OF NEXT WEEK. CULLEN
&&
.AVIATION...ISOLATED SHOWERS CONTINUE TO MOVE THROUGH THE REGION
THIS MORNING BRINGING A MIXTURE OF VFR TO MVFR CIGS TO THE INLAND
VALLEY. THE COAST REMAINS SOCKED IN UNDER WEAK ONSHORE FLOW WITH
IFR/LIFR CIGS AOB 700 FT. CONDITIONS INLAND LOOK TO GRADUALLY
IMPROVE TOWARDS WIDESPREAD VFR AFTER 18Z. CIGS ALONG THE COAST
LOOK TO LIFT LATE THIS MORNING WITH CONDITIONS LIKELY TURNING MVFR
FOR A FEW HOURS THIS AFTERNOON. ISOLATED TO SCATTERED SHOWERS LOOK
TO CONTINUE THROUGH AT LEAST THIS EVENING...WITH THUNDERSTORMS
POSSIBLE ALONG THE CASCADES AND FOOTHILLS. BRIEF PERIODS OF
REDUCED FLIGHT RULES WILL BE POSSIBLE UNDER HEAVIER SHOWERS.
CONDITIONS TONIGHT WILL ONCE AGAIN DETERIORATE TOWARDS MVFR INLAND
AND IFR ALONG THE COAST AS MARINE STRATUS RETURNS.
KPDX AND APPROACHES...A MIXTURE OF MVFR TO VFR CIGS WILL GIVE WAY
TO MOSTLY VFR CONDITIONS AFTER 18Z. SCATTERED SHOWERS CONTINUE
THROUGH THIS EVENING...WITH BRIEF PERIODS OF REDUCED FLIGHT RULES
POSSIBLE UNDER HEAVIER SHOWERS. CONDITIONS DETERIORATE TOWARD MVFR
LATE TONIGHT AS MARINE STRATUS RETURNS. /64
&&
.MARINE...A RATHER PERSISTENT WEATHER PATTERN WITH HIGH PRES
CENTERED ABOUT 600 NM OFFSHORE WILL CONTINUE THROUGH THE REST OF THE
WEEK AND THE WEEKEND. THIS WILL KEEP WINDS OUT OF THE NW BUT
GENERALLY BELOW 20 KT. A FRESH SWELL OF 5 TO 6 FT WILL ALSO
CONTINUE OUT OF THE WNW.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND
244 AM PDT THU MAY 21 2015
.SYNOPSIS...A BROAD UPPER LEVEL TROUGH OVER THE EASTERN PACIFIC AND
ALONG THE WEST COAST WITH LIGHT EASTERLY FLOW ALOFT WILL CONTINUE TO
BRING A THREAT OF SHOWERS AND THUNDERSTORMS TO THE CASCADES THURSDAY
AFTERNOON AND EVENING. ONSHORE FLOW WILL KEEP THE COAST CLOUDY AND
COOL...WITH LOW CLOUDS SPREADING INTO THE VALLEYS IN THE NIGHTS AND
MORNINGS. THE ONSHORE FLOW IS FORECAST TO INCREASE LATE THURSDAY AND
ESPECIALLY THURSDAY NIGHT AND FRIDAY AS ANOTHER SYSTEM DROPS IN FROM
THE NORTHWEST...PUSHING ANY THUNDER EAST OF THE CASCADES ON FRIDAY.
THE STRONGER ONSHORE FLOW WILL CONTINUE THROUGH THE WEEKEND WITH SOME
THREAT OF SHOWERS. ANOTHER UPPER LOW LOOKS LIKE IT WILL APPROACH THE
AREA EARLY NEXT WEEK...BRINGING CONTINUED SHOWER CHANCES.
&&
.SHORT TERM...CONVECTION HAS ONE LAST HURRAH THIS EVENING WITH A
STORM STRENGTHENING IN THE NEWPORT AREA AND PRODUCING A FEW LIGHTNING
STRIKES AND SOME FAIRLY HEAVY RAIN. SMALL ISOLATED SHOWERS REMAIN
TONIGHT...GENERALLY SOUTH OF SALEM AND TILLAMOOK AND THE HRRR SHOWS
THE TREND WILL LIKELY CONTINUE THROUGH THE EARLY MORNING HOURS. ADDED
PATCHY FOG FOR TONIGHT AND INTO EARLY THURSDAY MORNING ALONG THE
COAST AND IN THE SOUTH VALLEY WHERE SHOWERS COVERAGE WAS HIGHEST
WEDNESDAY. DO NOT EXPECT ANY SIGNIFICANTLY DETERIORATED VISIBILITY
WITH FOG TONIGHT AND INTO THURSDAY THOUGH.
MARINE CLOUDS CONTINUE TO HUG THE COAST...WITH CEILINGS
LOWER THAN LAST NIGHT LIKELY DUE TO A WEAKENING OF THE ONSHORE FLOW
INLAND TODAY. THE MODELS STILL SAY THE LOW CLOUDS SHOULD PUSH INLAND
LATER TONIGHT AND THURSDAY MORNING AND IT LOOKS LIKE THEY ARE
STARTING TO DO SO WITH LOW CLOUDS BEING REPORTED AT KELSO. AS
IMPULSES ROTATE AROUND THE LARGE SCALE WEST COAST LOW...THE MODELS
SAY THE ONSHORE FLOW WILL INCREASE THURSDAY AFTERNOON...AND IF THIS
HAPPENS IT IS POSSIBLE THE LOW CLOUDS WILL HAVE TROUBLE BREAKING UP
THURSDAY AFTERNOON. THIS MAY AGAIN KEEP THE BEST CHANCE OF THUNDER UP
IN THE CASCADES THURSDAY AFTERNOON AND EVENING.
THE MODELS SHOW ANOTHER SYSTEM DROPPING DOWN AND APPROACHING THE
SOUTH WASHINGTON AND NORTH OREGON COASTS FROM OFF THE B.C. COAST ON
FRIDAY. THIS REINFORCES THE ONSHORE FLOW IN SOUTHWEST WASHINGTON AND
NORTHWEST OREGON ON FRIDAY...AND MAY MAKE IT DIFFICULT FOR THE LOW
CLOUDS TO CLEAR AGAIN IN THE AFTERNOON. IN ADDITION...THE WINDS AT
ALL LEVELS ARE TURNING MORE WEST TO NORTHWESTERLY...AND THIS SHOULD
PUSH MOST OF THE THUNDERSTORMS EAST OF THE CASCADE CREST FRIDAY
AFTERNOON AND EVENING. IF ANY DO FORM...IT WILL BE BRIEFLY RIGHT AT
THE CREST AND THEN THEY WILL MOVE OFF INTO CENTRAL OREGON...BUT HAVE
LEFT THUNDER OUT OF THE FORECAST AT THIS TIME.
ON FRIDAY NIGHT AND SATURDAY...THE SYSTEM APPROACHING FROM THE
NORTHWEST MOVES ACROSS OUR AREA. THIS SHOULD MAINTAIN SUBSTANTIAL
ONSHORE FLOW. THE BIGGEST QUESTION IS WHETHER THE COLD POOL
ASSOCIATED WITH THE LOW WILL MOVE OVERHEAD...WHICH COULD TRIGGER SOME
SHOWERS OR EVEN SOME THUNDERSTORMS. THE MODELS HAVE SHOWN A VARIETY
OF SOLUTIONS. THE GFS HAS SUGGESTED AT TIMES THAT THE ABOVE SCENARIO
IS POSSIBLE. THE ECMWF AND CANADIAN MODELS HAVE BEEN SHEARING A LEAD
SHORT WAVE SOUTH ALONG THE COAST SATURDAY...WAITING UNTIL SUNDAY FOR
A TRAILING LOW TO COME OVERHEAD. WILL CONTINUE THE BROAD BRUSHED
CHANCE OF SHOWERS FOR NOW WITH MEDIOCRE CONFIDENCE IN ANY DETAILS AT
BEST. BOWEN/TOLLESON
.LONG TERM...NO SIGNIFICANT CHANGES. PREVIOUS DISCUSSION FOLLOWS...
SATURDAY NIGHT THROUGH WEDNESDAY...MODELS HAVE AGAIN COME INTO
REASONABLE AGREEMENT THAT AN UPPER LOW WILL SLIDE ACROSS THE PACIFIC
NORTHWEST LATE SATURDAY INTO SUNDAY...THOUGH STILL PLENTY OF SPREAD
AMONG MODEL GUIDANCE AS TO IF THE LOW TRACKS MORE EASTWARD ACROSS THE
CASCADES OR MORE SOUTHWARD TOWARDS THE GREAT BASIN.
REGARDLESS...INTRODUCED SLIGHT CHANCE POPS FOR MOST OF THE AREA
SUNDAY. MAY END UP SEEING SOME THUNDERSTORMS NEAR THE CASCADE CREST
IF THE UPPER LOW TRACKS OVERHEAD AND LINGERS. FLOW ALOFT LOOKS TO
REMAIN RATHER WEAK OR WEAKLY ONSHORE WITH CONTINUED POSSIBILITIES FOR
SHOWERS IN THE CASCADES. TEMPERATURES WILL REMAIN NEAR SEASONAL FOR
THE FIRST HALF OF NEXT WEEK. CULLEN
&&
.AVIATION...DESPITE THE FEW SHOWERS STILL MOVING W ACROSS NW OREGON
EARLY THU MORNING...CONDITIONS WERE GENERALLY VFR OVER INLAND
AREAS...WITH JUST A FEW PATCHES OF AN MVFR CIG SHOWING UP
OCCASIONALLY. A WEAK ONSHORE FLOW WAS KEEPING THE COAST SOCKED IN
WITH IFR CIGS. EXPECT SOME MVFR CIGS TO SPREAD LOCALLY INLAND THIS
MORNING BETWEEN 11Z AND 15Z...MOST LIKELY IN THE N VALLEY AT THE
KPDX AND KTTD TAF SITES. THERE IS ABOUT A 30 PERCENT CHANCE FOR MVFR
CIGS TO FORM ELSEWHERE. THE INLAND CIGS SHOULD GIVE WAY TO VFR
CONDITIONS AGAIN INLAND AREAS BETWEEN 18Z AND 20Z. ALONG THE COAST
CIGS ARE EXPECTED TO LIFT A FEW HUNDRED FEET DURING THE MORNING
BEFORE BREAKING UP BETWEEN 18Z AND 21Z. VFR CONDITIONS ARE LIKELY TO
BE SHORT LIVED ALONG THE COAST THOUGH...WITH IFR CIGS REFORMING AT
THE END OF THE DAY AFTER 01Z.
KPDX AND APPROACHES...VFR CONDITIONS ARE LIKELY TO GIVE WAY TO AN
MVFR CLOUD DECK SPREADING UP THE COLUMBIA RIVER BETWEEN 11Z AND 15Z.
AFTER A FEW HOURS OF MVFR CIGS...EXPECT VFR CONDITIONS TO REDEVELOP
AFTER 18Z TO 20Z...AND THEN TO PERSIST PAST 10Z TONIGHT.
&&
.MARINE...A RATHER PERSISTENT WEATHER PATTERN WITH HIGH PRES
CENTERED ABOUT 600 NM OFFSHORE WILL CONTINUE THROUGH THE REST OF THE
WEEK AND THE WEEKEND. THIS WILL KEEP WINDS OUT OF THE NW BUT
GENERALLY BELOW 20 KT. A FRESH SWELL OF 5 TO 6 FT WILL ALSO
CONTINUE OUT OF THE WNW.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
529 PM EDT THU MAY 21 2015
.SYNOPSIS...
AN UNSEASONABLY COOL WEATHER PATTERN WILL CONTINUE THROUGH THE
END OF THE WEEK WITH A RATHER CHILLY START TO THE WEEKEND. A
GRADUAL WARMING TREND IS FORECAST THROUGH THE EARLY TO MIDDLE PART
OF NEXT WEEK ALONG WITH AN INCREASING RISK FOR SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
FLOW AROUND AN AREA OF LOW PRESSURE OVER NORTH CAROLINA THIS AFTN
WILL CONTINUE TO SUPPORT A LARGE AREA OF CLOUDS ACROSS PA. RADAR
IMAGERY SHOWS THAT SHOWERS HAVE MOVED EAST OF THE STATE FOR THE
TIME BEING. HOWEVER...A SHORTWAVE CURRENTLY MOVING ACROSS THE
OHIO VALLEY WILL LIKELY HELP FIRE SOME MORE SHOWERS ACROSS THE NRN
MTNS AND LAURELS LATE THIS AFTN AND EVENING. LATEST HRRR GUIDANCE
SUGGESTS THOUGH THAT THEY SHOULD REMAIN ISOLATED IN COVERAGE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
THE MAIN LARGE SCALE UPPER TROUGH AXIS IS PROGGED TO ROTATE
THROUGH THE ERN GREAT LAKES AND NRN NEW ENGLAND ON FRIDAY WHICH
SHOULD DRIVE A RE-ENFORCING SFC COLD FRONT THROUGH CENTRAL PA.
MODEL CONSENSUS CONTINUES TO SUGGEST ISOLD/WDLY SCT SHOWERS WITH
THE FRONTAL PASSAGE BUT WITH VERY LIMITED MSTR KEPT POPS AOB 20
PCT. MAX TEMPS SHOULD MODERATE SOME BUT STILL AVG BELOW NORMAL
FOR THIS TIME OF YEAR.
BEHIND THE COLD FRONT ACROSS THE REGION...A SPRAWLING AREA OF
HIGH PRESSURE /1030MB+/ WILL BUILD UNDER A DEVELOPING LARGE UPPER
RIDGE OVER THE REGION. A REINFORCING SHOT OF COLDER AIR AHEAD OF
RIDGE AXIS WILL BRING QUITE CHILLY TEMPS FOR SAT MORNING...WHERE A
FREEZE IS LOOKING MORE LIKELY ACROSS MUCH OF THE NORTHERN MTNS. A
/WELL COORDINATED/ FREEZE WATCH REMAINS IN EFFECT THERE...WITH
SCT FROST EXTENDING INTO THE LAUREL HIGHLANDS AND PORTIONS OF THE
CENTRAL MTNS. POTENTIAL FLY IN THE OINTMENT COULD BE THE
WINDS...THOUGH LIGHT...REMAINING JUST HIGH ENOUGH TO KEEP TEMPS
FROM BOTTOMING OUT COMPLETELY.
THE COLD AIR IS QUICKLY REPLACED BY MODERATING TEMPS ON SAT...AS
HIGHS REBOUND INTO THE 60S UNDER FULL SUN. NOT QUITE AS CHILLY FOR
SAT NIGHT WITH LOWS SETTLING BACK INTO THE 40S IN MOST
LOCALES...UPPER 30S POSS IN THE NW MTNS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
SUNDAY MARKS BEGINNING OF A ROBUST WARM-UP THAT WILL CONTINUE
THROUGH NEXT WEEK. ALL GUIDANCE SIGNALS THIS WARMING TREND...WITH
HIGH CONFIDENCE IN ABOVE NORMAL TEMPERATURES BY MEMORIAL DAY AS
ANOMALOUS 500MB RIDGE BUILDS OVER THE EASTERN U.S.
SOME DIFFERENCES ON PLACEMENT OF A WARM FRONTAL ZONE LIFTING NWD
FROM THE SRN PLAINS/LWR MS VLY WHICH WILL HAVE IMPACTS ON PCPN
RISK EARLY NEXT WEEK...THOUGH BEST DAILY POPS /HIGH CHANCE TO LOW
LIKELY/ WILL BE OVER THE NW WITH CHANCE POPS IN THE SE.
SLOW EVOLVING FLOW PATTERN GRADUALLY TAKES RIDGE AXIS EASTWARD AS
TROUGH OVER THE CENTRAL PORTION OF THE COUNTY WEAKENS...WITH JET
STREAM RETREATING NORTHWARD AND BECOMING MORE ZONAL. THIS WILL
STRETCH A SLOWLY APPROACHING COLD FRONTAL BOUNDARY MORE W-E...AND
LIKELY REMAINING OFF TO OUR NW. WE/LL REMAIN ON THE VERY WARM AND
MUGGY SIDE OF THE FRONT IN A VERY SUMMER-LIKE PATTERN...KEEPING
DAILY SHOWER/TSTM CHANCES IN THE FORECAST. HIGHS FROM MONDAY
ONWARD WILL RANGE FROM THE UPPER 70S NORTH TO THE MID/UPPER 80S
SE...WITH MILD LOWS IN THE 60S TO AROUND 70 IN THE SE.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
A WEAK DISTURBANCE WILL PASS THROUGH THIS EVENING WHICH WILL SHIFT
THE LARGE SCALE FLOW TO THE NORTHWEST AND ALLOW FOR DRIER AIR TO
SWEEP INTO THE REGION OVERNIGHT. THE AREA OF MVFR/IFR FROM THE
CENTRAL MOUNTAINS INTO THE LAUREL HIGHLANDS WILL CONTINUE INTO THE
EVENING BEFORE GRADUALLY IMPROVING LATER THIS EVENING.
HIGH PRESSURE WILL BUILD ACROSS THE REGION FRIDAY INTO THE
WEEKEND.
OUTLOOK...
FRI-SUN...NO SIG WX EXPECTED.
MON-TUE...MAINLY VFR...MVFR POSS IN SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR PAZ004>006-010-011-017-037.
&&
$$
SYNOPSIS...GARTNER
NEAR TERM...GARTNER
SHORT TERM...GARTNER/RXR
LONG TERM...RXR/STEINBUGL
AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
359 PM EDT THU MAY 21 2015
.SYNOPSIS...
AN UNSEASONABLY COOL WEATHER PATTERN WILL CONTINUE THROUGH THE
END OF THE WEEK WITH A RATHER CHILLY START TO THE WEEKEND. A
GRADUAL WARMING TREND IS FORECAST THROUGH THE EARLY TO MIDDLE PART
OF NEXT WEEK ALONG WITH AN INCREASING RISK FOR SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
FLOW AROUND AN AREA OF LOW PRESSURE OVER NORTH CAROLINA THIS AFTN
WILL CONTINUE TO SUPPORT A LARGE AREA OF CLOUDS ACROSS PA. RADAR
IMAGERY SHOWS THAT SHOWERS HAVE MOVED EAST OF THE STATE FOR THE
TIME BEING. HOWEVER...A SHORTWAVE CURRENTLY MOVING ACROSS THE
OHIO VALLEY WILL LIKELY HELP FIRE SOME MORE SHOWERS ACROSS THE NRN
MTNS AND LAURELS LATE THIS AFTN AND EVENING. LATEST HRRR GUIDANCE
SUGGESTS THOUGH THAT THEY SHOULD REMAIN ISOLATED IN COVERAGE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
THE MAIN LARGE SCALE UPPER TROUGH AXIS IS PROGGED TO ROTATE
THROUGH THE ERN GREAT LAKES AND NRN NEW ENGLAND ON FRIDAY WHICH
SHOULD DRIVE A RE-ENFORCING SFC COLD FRONT THROUGH CENTRAL PA.
MODEL CONSENSUS CONTINUES TO SUGGEST ISOLD/WDLY SCT SHOWERS WITH
THE FRONTAL PASSAGE BUT WITH VERY LIMITED MSTR KEPT POPS AOB 20
PCT. MAX TEMPS SHOULD MODERATE SOME BUT STILL AVG BELOW NORMAL
FOR THIS TIME OF YEAR.
BEHIND THE COLD FRONT ACROSS THE REGION...A SPRAWLING AREA OF
HIGH PRESSURE /1030MB+/ WILL BUILD UNDER A DEVELOPING LARGE UPPER
RIDGE OVER THE REGION. A REINFORCING SHOT OF COLDER AIR AHEAD OF
RIDGE AXIS WILL BRING QUITE CHILLY TEMPS FOR SAT MORNING...WHERE A
FREEZE IS LOOKING MORE LIKELY ACROSS MUCH OF THE NORTHERN MTNS. A
/WELL COORDINATED/ FREEZE WATCH REMAINS IN EFFECT THERE...WITH
SCT FROST EXTENDING INTO THE LAUREL HIGHLANDS AND PORTIONS OF THE
CENTRAL MTNS. POTENTIAL FLY IN THE OINTMENT COULD BE THE
WINDS...THOUGH LIGHT...REMAINING JUST HIGH ENOUGH TO KEEP TEMPS
FROM BOTTOMING OUT COMPLETELY.
THE COLD AIR IS QUICKLY REPLACED BY MODERATING TEMPS ON SAT...AS
HIGHS REBOUND INTO THE 60S UNDER FULL SUN. NOT QUITE AS CHILLY FOR
SAT NIGHT WITH LOWS SETTLING BACK INTO THE 40S IN MOST
LOCALES...UPPER 30S POSS IN THE NW MTNS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
SUNDAY MARKS BEGINNING OF A ROBUST WARM-UP THAT WILL CONTINUE
THROUGH NEXT WEEK. ALL GUIDANCE SIGNALS THIS WARMING TREND...WITH
HIGH CONFIDENCE IN ABOVE NORMAL TEMPERATURES BY MEMORIAL DAY AS
ANOMALOUS 500MB RIDGE BUILDS OVER THE EASTERN U.S.
SOME DIFFERENCES ON PLACEMENT OF A WARM FRONTAL ZONE LIFTING NWD
FROM THE SRN PLAINS/LWR MS VLY WHICH WILL HAVE IMPACTS ON PCPN
RISK EARLY NEXT WEEK...THOUGH BEST DAILY POPS /HIGH CHANCE TO LOW
LIKELY/ WILL BE OVER THE NW WITH CHANCE POPS IN THE SE.
SLOW EVOLVING FLOW PATTERN GRADUALLY TAKES RIDGE AXIS EASTWARD AS
TROUGH OVER THE CENTRAL PORTION OF THE COUNTY WEAKENS...WITH JET
STREAM RETREATING NORTHWARD AND BECOMING MORE ZONAL. THIS WILL
STRETCH A SLOWLY APPROACHING COLD FRONTAL BOUNDARY MORE W-E...AND
LIKELY REMAINING OFF TO OUR NW. WE/LL REMAIN ON THE VERY WARM AND
MUGGY SIDE OF THE FRONT IN A VERY SUMMER-LIKE PATTERN...KEEPING
DAILY SHOWER/TSTM CHANCES IN THE FORECAST. HIGHS FROM MONDAY
ONWARD WILL RANGE FROM THE UPPER 70S NORTH TO THE MID/UPPER 80S
SE...WITH MILD LOWS IN THE 60S TO AROUND 70 IN THE SE.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
FLOW AROUND AN AREA OF LOW PRESSURE OVER NORTH CAROLINA THIS AFTN
WILL CONTINUE TO SUPPORT A LARGE AREA OF CLOUDS ACROSS PA. MOST
OF THE CIGS ARE...AND WILL REMAIN VFR...BUT UPSLOPE FLOW IS
CAUSING SOME LOWERED CIGS AT KAOO AND KUNV AND IFR AT KJST.
SHOWERS HAVE MOVED EAST OF THE STATE FOR THE TIME BEING.
HOWEVER...A SHORTWAVE MOVING ACROSS THE OHIO VALLEY WILL LIKELY
HELP FIRE SOME MORE SHOWERS ACROSS THE WRN AND NRN MTNS LATE THIS
AFTN AND EVENING....THOUGH THEY SHOULD REMAIN ISOLATED IN
COVERAGE.
IMPROVING FLYING CONDS ARE EXPECTED LATER THIS EVENING...AS WINDS
SHIFT TO THE NW...DRAWING DRIER AIR AND CLEARING SKIES INTO THE
REGION.
HIGH PRESSURE WILL BUILD ACROSS THE REGION FRIDAY INTO THE
WEEKEND.
OUTLOOK...
FRI-SUN...NO SIG WX EXPECTED.
MON-TUE...MAINLY VFR...MVFR POSS IN SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR PAZ004>006-010-011-017-037.
&&
$$
SYNOPSIS...GARTNER
NEAR TERM...GARTNER
SHORT TERM...GARTNER/RXR
LONG TERM...RXR/STEINBUGL
AVIATION...FITZGERALD/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
308 PM EDT THU MAY 21 2015
.SYNOPSIS...
AN UNSEASONABLY COOL WEATHER PATTERN WILL CONTINUE THROUGH THE
END OF THE WEEK WITH A RATHER CHILLY START TO THE WEEKEND. A
GRADUAL WARMING TREND IS FORECAST THROUGH THE EARLY TO MIDDLE PART
OF NEXT WEEK ALONG WITH AN INCREASING RISK FOR SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
FLOW AROUND AN AREA OF LOW PRESSURE OVER NORTH CAROLINA THIS AFTN
WILL CONTINUE TO SUPPORT A LARGE AREA OF CLOUDS ACROSS PA. RADAR
IMAGERY SHOWS THAT SHOWERS HAVE MOVED EAST OF THE STATE FOR THE
TIME BEING. HOWEVER...A SHORTWAVE CURRENTLY MOVING ACROSS THE
OHIO VALLEY WILL LIKELY HELP FIRE SOME MORE SHOWERS ACROSS THE NRN
MTNS AND LAURELS LATE THIS AFTN AND EVENING. LATEST HRRR GUIDANCE
SUGGESTS THOUGH THAT THEY SHOULD REMAIN ISOLATED IN COVERAGE.
&&
.SHORT TERM /FRIDAY...
THE MAIN LARGE SCALE UPPER TROUGH AXIS IS PROGGED TO ROTATE
THROUGH THE ERN GREAT LAKES AND NRN NEW ENGLAND ON FRIDAY WHICH
SHOULD DRIVE A RE-ENFORCING SFC COLD FRONT THROUGH CENTRAL PA.
MODEL CONSENSUS CONTINUES TO SUGGEST ISOLD/WDLY SCT SHOWERS WITH
THE FRONTAL PASSAGE BUT WITH VERY LIMITED MSTR KEPT POPS AOB 20
PCT. MAX TEMPS SHOULD MODERATE SOME BUT STILL AVG BELOW NORMAL
FOR THIS TIME OF YEAR.
BEHIND THE COLD FRONT...A SPRAWLING AREA OF HIGH PRESSURE WILL
BUILD INTO THE REGION STARTING FRIDAY NIGHT. NO SIGNIFICANT ACTIVE
WEATHER IS EXPECTED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
CONFIDENCE CONTINUES TO INCREASE FOR AREAS OF FROST ALONG THE
ALLEGHENY FRONT BY SATURDAY MORNING. COULD EVEN SEE SOME FROST IN
THE OUTLYING AREAS AROUND STATE COLLEGE. WITH A FAVORABLE PATTERN
AND SUPPORT FROM MODEL CONSENSUS...COLLABORATED WITH BUF/BGM ON A
FREEZE WATCH FOR THE NRN MTNS WITH FCST MINS IN THE 28-32F RANGE.
WILL ALSO CONTINUE TO HIGHLIGHT FROST RISK IN THE HWO AND LATER
SHIFTS CAN ADD FROST HEADLINES AS NEEDED.
ALL GUIDANCE CONTINUES TO SIGNAL A WARMING TREND INTO THE MIDDLE
OF NEXT WEEK...WITH HIGH CONFIDENCE IN ABOVE NORMAL TEMPERATURES
BY MEMORIAL DAY AS ANOMALOUS 500MB RIDGE BUILDS OVER THE EASTERN
U.S. GFS/ECMWF DISAGREE ON PLACEMENT OF WARM FRONTAL ZONE LIFTING
NWD FROM THE SRN PLAINS/LWR MS VLY. THIS WILL LKLY IMPACT PCPN
RISK EARLY NEXT WEEK. A COLD FRONT IS PROGGED TO APPROACH THE AREA
LATER IN THE WEEK. WITH LOW CONFIDENCE IN BOUNDARY PLACEMENT AT
THIS RANGE...WILL MAINTAIN DAILY RISK OF MAINLY AFTERNOON
THUNDERSTORMS GIVEN INCREASINGLY HUMID/MUGGY SUMMER-LIKE PATTERN.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
FLOW AROUND AN AREA OF LOW PRESSURE OVER NORTH CAROLINA THIS AFTN
WILL CONTINUE TO SUPPORT A LARGE AREA OF CLOUDS ACROSS PA. MOST
OF THE CIGS ARE...AND WILL REMAIN VFR...BUT UPSLOPE FLOW IS
CAUSING SOME LOWERED CIGS AT KAOO AND KUNV AND IFR AT KJST.
SHOWERS HAVE MOVED EAST OF THE STATE FOR THE TIME BEING.
HOWEVER...A SHORTWAVE MOVING ACROSS THE OHIO VALLEY WILL LIKELY
HELP FIRE SOME MORE SHOWERS ACROSS THE WRN AND NRN MTNS LATE THIS
AFTN AND EVENING....THOUGH THEY SHOULD REMAIN ISOLATED IN
COVERAGE.
IMPROVING FLYING CONDS ARE EXPECTED LATER THIS EVENING...AS WINDS
SHIFT TO THE NW...DRAWING DRIER AIR AND CLEARING SKIES INTO THE
REGION.
HIGH PRESSURE WILL BUILD ACROSS THE REGION FRIDAY INTO THE
WEEKEND.
OUTLOOK...
FRI-SUN...NO SIG WX EXPECTED.
MON-TUE...MAINLY VFR...MVFR POSS IN SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR PAZ004>006-010-011-037.
&&
$$
SYNOPSIS...GARTNER
NEAR TERM...GARTNER
SHORT TERM...GARTNER/STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
718 AM EDT THU MAY 21 2015
.SYNOPSIS...
A SEASONABLY COOL WEATHER PATTERN WILL CONTINUE THROUGH THE END OF
THE WEEK WITH A RATHER CHILLY START TO THE WEEKEND. A GRADUAL
WARMING TREND IS FORECAST THROUGH THE EARLY TO MIDDLE PART OF NEXT
WEEK ALONG WITH AN INCREASING RISK FOR SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
EARLY AM WV LOOP SHOWS A WELL DEFINED MID LVL SHORTWAVE TRACKING
EASTWARD ACROSS S ONTARIO. LOW TO MID LVL THETA-E ADVECTION AHEAD
OF THE WAVE ALONG WITH MODEST HEIGHT FALLS AND PERHAPS SOME RIGHT
ENTRANCE REGION JET DYNAMICS ARE COMBINING TO PRODUCE SOME
SPOTTY/VERY LIGHT RAIN ACROSS EASTERN OHIO/WESTERN PA AS OF 0830Z.
UPSTREAM SFC REPORTS INDICATING ONLY A FEW HUNDREDTHS OF AN INCH
RAIN FROM THIS FEATURE OVR OHIO AND SUSPECT EVEN LESS OVR MOST OF
CENTRAL PA...WHERE DRY AIR IN THE LOW LVLS IS CURRENTLY
RESULTING IN VIRGA. WEAKENING SHORTWAVE WILL PASS NORTH OF PA
LATER THIS MORNING...CAUSING DWINDLING AREA OF -SHRA TO PRESS
EAST. LATEST 4KM NAM/HRRR INDICATE ONLY A SLIGHT CHC OF LINGERING
-SHRA BY NOON ACROSS THE SE COUNTIES.
A SECOND SHORTWAVE...DIVING INTO THE UPPER MIDWEST THIS AM...WILL
PUSH INTO WESTERN PA BY THIS EVENING. INCREASING LG SCALE FORCING
AHEAD OF THIS FEATURE WILL LIKELY PRODUCE ANOTHER ROUND OF SCT
-SHRA THIS EVENING. ALL NR TERM MDL INDICATE THE BEST CHC OF
MEASURABLE RAIN WILL BE ACROSS THE CENTRAL MTNS THIS
EVENING...ALONG PLUME OF SLIGHTLY HIGHER PWATS.
OVERCAST SKIES...COMBINED WITH AN ALREADY CHILLY AIR MASS OVR THE
AREA...WILL RESULT IN AN UNSEASONABLY COOL DAY WITH AFTERNOON
HIGHS 10 TO 20 DEGREES BELOW LATE MAY CLIMO...RANGING FROM 55-60F
OVER MOST OF CENTRAL PA.
TRENDED POPS DOWNWARD FROM NW TO SE EARLY TONIGHT AS DRIER AIR
ARRIVES IN WAKE OF PASSING SHORTWAVE. SFC LOW PASSING OFF THE MID
ATL COAST STRENGTHENS A BIT...WHICH SHOULD LEAD TO A SLIGHT
UPTICK IN NW WINDS INTO FRIDAY MORNING. LOWS SHOULD AVG IN THE
L-M40S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THE MAIN LARGE SCALE UPPER TROUGH AXIS IS PROGGED TO ROTATE
THROUGH THE ERN GREAT LAKES AND NRN NEW ENGLAND ON DAY 2 WHICH
SHOULD DRIVE A RE-ENFORCING SFC COLD FRONT THROUGH CENTRAL PA.
MODEL CONSENSUS CONTINUES TO SUGGEST ISOLD/WDLY SCT SHOWERS WITH
THE FRONTAL PASSAGE BUT WITH VERY LIMITED MSTR KEPT POPS AOB 20
PCT. DAY 2 MAX TEMPS SHOULD MODERATE SOME BUT STILL AVG BELOW
NORMAL FOR THIS TIME OF YEAR.
BEHIND THE COLD FRONT...A SPRAWLING AREA OF HIGH PRESSURE WILL
BUILD INTO THE REGION FRI NIGHT/A.M. SATURDAY. CONFIDENCE
CONTINUES TO INCREASE FOR AREAS OF FROST ALONG THE ALLEGHENY
FRONT BY SATURDAY MORNING. COULD EVEN SEE SOME FROST IN THE
OUTLYING AREAS AROUND STATE COLLEGE. WITH A FAVORABLE PATTERN AND
SUPPORT FROM MODEL CONSENSUS...COLLABORATED WITH BUF/BGM ON A
FREEZE WATCH FOR THE NRN MTNS WITH FCST MINS IN THE 28-32F RANGE.
WILL ALSO CONTINUE TO HIGHLIGHT FROST RISK IN THE HWO AND LATER
SHIFTS CAN ADD FROST HEADLINES AS NEEDED.
AFTER A RATHER CHILLY START TO THE WEEKEND...TEMPS SHOULD REBOUND
NICELY ON SATURDAY WITH HIGHS GENERALLY FROM 65-70F. HIGH PRESSURE
SLIDES OFF THE MID ATLC COAST SATURDAY NIGHT WITH A WARMER RETURN
FLOW SETTING UP INTO SUNDAY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ALL GUIDANCE CONTINUES TO SIGNAL A WARMING TREND INTO THE MIDDLE
OF NEXT WEEK...WITH HIGH CONFIDENCE IN ABOVE NORMAL TEMPERATURES
BY MEMORIAL DAY AS ANOMALOUS 500MB RIDGE BUILDS OVER THE EASTERN
U.S. GFS/ECMWF DISAGREE ON PLACEMENT OF WARM FRONTAL ZONE LIFTING
NWD FROM THE SRN PLAINS/LWR MS VLY. THIS WILL LKLY IMPACT PCPN
RISK EARLY NEXT WEEK. A COLD FRONT IS PROGGED TO APPROACH THE AREA
LATER IN THE WEEK. WITH LOW CONFIDENCE IN BOUNDARY PLACEMENT AT
THIS RANGE...WILL MAINTAIN DAILY RISK OF MAINLY AFTERNOON
THUNDERSTORMS GIVEN INCREASINGLY HUMID/MUGGY SUMMER-LIKE PATTERN.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
A WEAK AREA OF LOW PRESSURE WILL TRACK SOUTH OF PENNSYLVANIA EARLY
THIS MORNING...BRINGING A SCT -SHRA TO THE CENTRAL AND SOUTHERN
PART OF THE STATE. DRY AIR AT LOW LEVELS SHOULD ENSURE VFR CONDS
OVER MOST OF THE AREA. HOWEVER...A MOISTENING SERLY FLOW ASCENDING
THE HIGHER TERRAIN OF SOUTH CENTRAL PA IS LIKELY TO PRODUCE MVFR
CIGS AT KJST/KAOO...AND POSSIBLY KUNV...DURING MUCH OF THE
DAYLIGHT HOURS. LATEST HRRR EVEN IMPLIES THE CHC OF IFR CIGS AT
KJST BTWN 13Z-16Z. HOWEVER...ODDS OF THIS STILL ONLY ARND 50 PCT.
IMPROVING FLYING CONDS EXPECTED THIS EVENING...AS WINDS SHIFT TO
THE NW...DRAWING DRIER AIR AND CLEARING SKIES INTO THE REGION.
OUTLOOK...
FRI-SUN...NO SIG WX EXPECTED.
MON...MAINLY VFR...MVFR POSS IN SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR PAZ004>006-010-011-037.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
538 AM EDT THU MAY 21 2015
.SYNOPSIS...
A SEASONABLY COOL WEATHER PATTERN WILL CONTINUE THROUGH THE END OF
THE WEEK WITH A RATHER CHILLY START TO THE WEEKEND. A GRADUAL
WARMING TREND IS FORECAST THROUGH THE EARLY TO MIDDLE PART OF NEXT
WEEK ALONG WITH AN INCREASING RISK FOR SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
EARLY AM WV LOOP SHOWS A WELL DEFINED MID LVL SHORTWAVE TRACKING
EASTWARD ACROSS S ONTARIO. LOW TO MID LVL THETA-E ADVECTION AHEAD
OF THE WAVE ALONG WITH MODEST HEIGHT FALLS AND PERHAPS SOME RIGHT
ENTRANCE REGION JET DYNAMICS ARE COMBINING TO PRODUCE SOME
SPOTTY/VERY LIGHT RAIN ACROSS EASTERN OHIO/WESTERN PA AS OF 0830Z.
UPSTREAM SFC REPORTS INDICATING ONLY A FEW HUNDREDTHS OF AN INCH
RAIN FROM THIS FEATURE OVR OHIO AND SUSPECT EVEN LESS OVR MOST OF
CENTRAL PA...WHERE DRY AIR IN THE LOW LVLS IS CURRENTLY
RESULTING IN VIRGA. WEAKENING SHORTWAVE WILL PASS NORTH OF PA
LATER THIS MORNING...CAUSING DWINDLING AREA OF -SHRA TO PRESS
EAST. LATEST 4KM NAM/HRRR INDICATE ONLY A SLIGHT CHC OF LINGERING
-SHRA BY NOON ACROSS THE SE COUNTIES.
A SECOND SHORTWAVE...DIVING INTO THE UPPER MIDWEST THIS AM...WILL
PUSH INTO WESTERN PA BY THIS EVENING. INCREASING LG SCALE FORCING
AHEAD OF THIS FEATURE WILL LIKELY PRODUCE ANOTHER ROUND OF SCT
-SHRA THIS EVENING. ALL NR TERM MDL INDICATE THE BEST CHC OF
MEASURABLE RAIN WILL BE ACROSS THE CENTRAL MTNS THIS
EVENING...ALONG PLUME OF SLIGHTLY HIGHER PWATS.
OVERCAST SKIES...COMBINED WITH AN ALREADY CHILLY AIR MASS OVR THE
AREA...WILL RESULT IN AN UNSEASONABLY COOL DAY WITH AFTERNOON
HIGHS 10 TO 20 DEGREES BELOW LATE MAY CLIMO...RANGING FROM 55-60F
OVER MOST OF CENTRAL PA.
TRENDED POPS DOWNWARD FROM NW TO SE EARLY TONIGHT AS DRIER AIR
ARRIVES IN WAKE OF PASSING SHORTWAVE. SFC LOW PASSING OFF THE MID
ATL COAST STRENGTHENS A BIT...WHICH SHOULD LEAD TO A SLIGHT
UPTICK IN NW WINDS INTO FRIDAY MORNING. LOWS SHOULD AVG IN THE
L-M40S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THE MAIN LARGE SCALE UPPER TROUGH AXIS IS PROGGED TO ROTATE
THROUGH THE ERN GREAT LAKES AND NRN NEW ENGLAND ON DAY 2 WHICH
SHOULD DRIVE A RE-ENFORCING SFC COLD FRONT THROUGH CENTRAL PA.
MODEL CONSENSUS CONTINUES TO SUGGEST ISOLD/WDLY SCT SHOWERS WITH
THE FRONTAL PASSAGE BUT WITH VERY LIMITED MSTR KEPT POPS AOB 20
PCT. DAY 2 MAX TEMPS SHOULD MODERATE SOME BUT STILL AVG BELOW
NORMAL FOR THIS TIME OF YEAR.
BEHIND THE COLD FRONT...A SPRAWLING AREA OF HIGH PRESSURE WILL
BUILD INTO THE REGION FRI NIGHT/A.M. SATURDAY. CONFIDENCE
CONTINUES TO INCREASE FOR AREAS OF FROST ALONG THE ALLEGHENY
FRONT BY SATURDAY MORNING. COULD EVEN SEE SOME FROST IN THE
OUTLYING AREAS AROUND STATE COLLEGE. WITH A FAVORABLE PATTERN AND
SUPPORT FROM MODEL CONSENSUS...COLLABORATED WITH BUF/BGM ON A
FREEZE WATCH FOR THE NRN MTNS WITH FCST MINS IN THE 28-32F RANGE.
WILL ALSO CONTINUE TO HIGHLIGHT FROST RISK IN THE HWO AND LATER
SHIFTS CAN ADD FROST HEADLINES AS NEEDED.
AFTER A RATHER CHILLY START TO THE WEEKEND...TEMPS SHOULD REBOUND
NICELY ON SATURDAY WITH HIGHS GENERALLY FROM 65-70F. HIGH PRESSURE
SLIDES OFF THE MID ATLC COAST SATURDAY NIGHT WITH A WARMER RETURN
FLOW SETTING UP INTO SUNDAY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ALL GUIDANCE CONTINUES TO SIGNAL A WARMING TREND INTO THE MIDDLE
OF NEXT WEEK...WITH HIGH CONFIDENCE IN ABOVE NORMAL TEMPERATURES
BY MEMORIAL DAY AS ANOMALOUS 500MB RIDGE BUILDS OVER THE EASTERN
U.S. GFS/ECMWF DISAGREE ON PLACEMENT OF WARM FRONTAL ZONE LIFTING
NWD FROM THE SRN PLAINS/LWR MS VLY. THIS WILL LKLY IMPACT PCPN
RISK EARLY NEXT WEEK. A COLD FRONT IS PROGGED TO APPROACH THE AREA
LATER IN THE WEEK. WITH LOW CONFIDENCE IN BOUNDARY PLACEMENT AT
THIS RANGE...WILL MAINTAIN DAILY RISK OF MAINLY AFTERNOON
THUNDERSTORMS GIVEN INCREASINGLY HUMID/MUGGY SUMMER-LIKE PATTERN.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
A WEAK AREA OF LOW PRESSURE WILL TRACK SOUTH OF PENNSYLVANIA EARLY
THIS MORNING...BRINGING A FEW -SHRA TO THE CENTRAL AND SOUTHERN
PART OF THE STATE. HOWEVER...DRY AIR AT LOW LEVELS SHOULD ENSURE
VFR CONDS LAST THRU DAWN. THE -SHRA SHOULD PASS EAST OF THE AREA
BY LATE MORNING. HOWEVER...A MOISTENING SERLY FLOW ASCENDING THE
HIGHER TERRAIN OF SOUTH CENTRAL PA IS LIKELY TO PRODUCE MVFR CIGS
AT KJST/KAOO...AND POSSIBLY KUNV...DURING MUCH OF THE DAYLIGHT
HOURS. HRRR EVEN IMPLIES THE CHC OF IFR CIGS AT KJST THIS AFTN.
HOWEVER...ODDS OF THIS STILL LESS THAN 50 PCT. IMPROVING FLYING
CONDS EXPECTED THIS EVENING...AS WINDS SHIFT TO THE NW...DRAWING
DRIER AIR AND CLEARING SKIES INTO THE REGION.
OUTLOOK...
FRI-SUN...NO SIG WX EXPECTED.
MON...MAINLY VFR...MVFR POSS IN SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR PAZ004>006-010-011-037.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
842 PM CDT FRI MAY 22 2015
.UPDATE...
SHOWERS THAT DEVELOPED OVER EASTERN OKLAHOMA THIS AFTERNOON
CONTINUE TO PUSH EAST ACROSS ARKANSAS. LATEST HRRR SHOWS THAT THE
SHOWERS MAY SKIRT PORTIONS OF EASTERN ARKANSAS DURING THE EARLY
MORNING HOURS BEFORE DYING OUT. WILL UPDATE TO ADD 20 POPS. IN
ADDITION BLOW OFF HIGH CLOUDS FROM THIS SHOWER ACTIVITY CURRENTLY
COVERS MUCH OF THE MIDSOUTH. WILL ALSO UPDATE TO BUMP UP SKY COVER
TO MOSTLY CLOUDY FOR AT LEAST THE NORTHWEST HALF OF THE CWA DURING
THE OVERNIGHT HOURS. THE CLOUDS MAY KEEP TEMPERATURES WARMER THAN
EXPECTED OVER AT LEAST WEST TENNESSEE NEAR THE TENNESSEE RIVER.
WILL WAIT FOR ONE MORE OB BEFORE DECIDING IF LOWS NEED TO BE
RAISED IN THAT PARTICULAR HOUR.
KRM
&&
.DISCUSSION... /ISSUED 301 PM CDT FRI MAY 22 2015/
SKIES REMAIN MOSTLY SUNNY ACROSS THE FORECAST AREA THIS AFTERNOON
WITH TEMPERATURES IN THE UPPER 60S TO LOWER 70S. HIGH PRESSURE WAS
CENTERED OVER WESTERN KENTUCKY THIS AFTERNOON. THIS HIGH WILL MOVE
EAST OF THE REGION TONIGHT. TEMPERATURES WILL NOT BE NEARLY AS
CHILLY AS THIS MORNING WITH LOWS SATURDAY MORNING MAINLY IN THE
50S.
ON SATURDAY...WINDS WILL START TO BECOME MORE SOUTHERLY WHICH WILL
BRING WARMER AND MORE HUMID AIR INTO THE REGION. TEMPERATURES WILL
BE CLOSER TO NORMAL LEVELS WITH HIGHS MAINLY IN THE LOWER 80S. BY
SATURDAY NIGHT A WARM FRONT WILL START TO LIFT NORTH THROUGH THE
SOUTHERN PLAINS AND MUCH OF ARKANSAS. SOME THUNDERSTORMS ARE
EXPECTED TO DEVELOP ALONG AND AHEAD OF THE WARM FRONT AND SOME OF
THIS ACTIVITY MAY REACH WESTERN SECTIONS OF THE FORECAST AREA.
ON SUNDAY...A COLD FRONT WILL BE MOVING INTO THE SOUTHERN PLAINS.
THUNDERSTORMS ARE EXPECTED TO FORM AHEAD OF THE FRONT AND SOME OF
THIS ACTIVITY MAY MOVE INTO THE FORECAST AREA WITH THE BEST CHANCE
OF RAIN OVER AREAS WEST OF THE MISSISSIPPI RIVER. TEMPERATURES
WILL BE A LITTLE WARMER WITH HIGHS IN THE LOW TO MID 80S. AS THE
COLD FRONT MOVES CLOSER TO THE FORECAST AREA SUNDAY NIGHT THERE
WILL BE A BETTER CHANCE OF THUNDERSTORMS.
ON MONDAY...THE COLD FRONT WILL BE CLOSER TO THE FORECAST AREA SO
THIS WILL BE THE MOST LIKELY PERIOD FOR THUNDERSTORMS. THE COLD
FRONT WILL WEAKEN BEFORE IT REACHES THE FORECAST AREA SO RAIN
CHANCES WILL DIMINISH ON MONDAY NIGHT.
BY TUESDAY...AN UPPER LEVEL LOW IS FORECAST TO MOVE ACROSS EASTERN
KANSAS AND INTO MISSOURI. THIS WILL PRODUCE MORE THUNDERSTORMS
ACROSS THE FORECAST AREA FOR TUESDAY AND TUESDAY NIGHT. THE UPPER
LOW WILL MOVE INTO THE OHIO VALLEY ON WEDNESDAY WITH A DECREASING
CHANCE OF THUNDERSTORMS.
THE WEATHER PATTERN BECOMES MORE SUMMER LIKE FOR THURSDAY AND NEXT
FRIDAY WITH A CHANCE OF MAINLY AFTERNOON THUNDERSTORMS WITH
TEMPERATURES CLOSE TO NORMAL LEVELS.
ARS
&&
.AVIATION...
18Z TAF CYCLE
VFR. LIGHT WINDS OVERNIGHT BECOMING SE 6-8 KTS SATURDAY.
SJM
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
817 PM CDT FRI MAY 22 2015
.UPDATE...
MOIST COOL AIRMASS WITH FOG DEVELOPING EARLY THIS EVENING IN THE
SOUTHERN AND CENTRAL SOUTH PLAINS. RAP SHORT TERM SOLUTION
INDICATES GOOD CHANCE THIS WILL EXPAND FURTHER NORTH AND WEST
DURING THE EVENING. UPDATED FOR THE FOG. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 650 PM CDT FRI MAY 22 2015/
AVIATION...
LOW CIGS ARE HERE TO STAY THROUGH A MAJORITY OF THIS TAF PERIOD.
IFR TO MVFR CIGS THIS EVENING ARE EXPECTED TO QUICKLY DROP SOLIDLY
INTO IFR AND POSSIBLY LIFR TONIGHT. AN UPPER LEVEL DISTURBANCE
MOVING OVER THE REGION TONIGHT WILL GENERATE WIDESPREAD SHOWERS
AND THUNDERSTORMS DURING THE EARLY MORNING HOURS ON SATURDAY. IF
ANY STORMS DO IMPACT A TAF SITE...THE VISIBILITY WILL LIKELY DROP
FOR A BRIEF TIME BUT LOW CIGS WILL REMAIN. AFTER STORMS CLEAR THE
AREA LATE SATURDAY MORNING OR EARLY AFTERNOON...CIGS WILL
EVENTUALLY RISE INTO MVFR AND POSSIBLY VFR BY THE END OF THIS TAF
PERIOD.
PREV DISCUSSION... /ISSUED 351 PM CDT FRI MAY 22 2015/
SHORT TERM...
.A FLASH FLOOD WATCH IS NOW IN EFFECT FOR THE ENTIRE
AREA...EFFECTIVE FROM MIDNIGHT TONIGHT THROUGH EARLY SATURDAY
AFTERNOON...
AFTER THE EARLY DAY CONVECTION THINGS HAVE BEEN FAIRLY QUIET THIS
AFTERNOON...BUT THE WEATHER WILL SWING BACK TOWARD THE ACTIVE SIDE
LATE TONIGHT. THIS WILL OCCUR AS ANOTHER UPPER LEVEL DISTURBANCE
RAPIDLY APPROACHES FROM THE SOUTHWEST AHEAD OF THE PRIMARY UPPER LOW
MAKING ITS WAY SLOWLY EASTWARD THROUGH THE DESERT SOUTHWEST.
TEMPERATURES HAVE BEEN SLOW TO WARM TODAY WITH CLOUD COVER HOLDING
TOUGH...THOUGH WE HAVE SEEN READINGS EDGING UP INTO THE 60S FOR THE
FIRST TIME IN A WHILE AS SOUTHEASTERLY WINDS AND LIMITED INSOLATION
HAVE PROVIDED SOME MODIFICATION. THE MOIST SOUTHEAST FLOW WILL
STRENGTHEN TONIGHT IN ADVANCE OF THE APPROACHING WAVE...WITH STRONG
MOISTURE ADVECTION AND INCREASING UPPER DIVERGENCE AND LIFT
SUPPORTING THE RISK FOR WIDESPREAD RAIN...SOME WHICH WILL BE
HEAVY...LATE TONIGHT.
INITIALLY...CONVECTION WILL LIKELY DEVELOP IN SOUTHEAST NEW MEXICO
AND SOUTHWEST TEXAS THIS EVENING BEFORE GROWING UPSCALE INTO ONE OR
TWO COMPLEXES AS THEY MOVE NORTHEAST INTO AND ACROSS THE SOUTH
PLAINS REGION SATURDAY MORNING. IT APPEARS THE BULK OF THE ACTIVITY
WILL HOLD OFF LOCALLY UNTIL AROUND OR AFTER MIDNIGHT...WITH HEAVIER
RAIN AFFECTING LOCATIONS ON THE CAPROCK IN THE 06-12Z
TIME-FRAME...THEN SPREADING OFF THE CAPROCK BY 09-12Z. AS
USUAL...THERE ARE DIFFERENCES REGARDING THE PLACEMENT OF THE
HEAVIEST RAIN...WITH SOME NWP SUGGESTING THE NORTHWEST ZONES MOST
FAVORED...WHILE OTHER SOLUTIONS LIKE THE CENTRAL AND EASTERN ZONES.
IT IS TOUGH TO SAY EXACTLY WHERE THE HEAVIEST RAIN WILL FALL...BUT
SOMEONE IN THE AREA WILL LIKELY SEE A QUICK 1-3+ INCHES...WHICH WHEN
FALLING ON TOP OF THE ALREADY SATURATED SOILS...WILL RESULT IN
FLOODING ISSUES. OUTSIDE OF THE HEAVIEST RAIN SWATHS...A SOLID INCH
OF RAIN WILL LIKELY FALL IN MANY SPOTS. THE MOST WIDESPREAD AND
HEAVY RAIN WILL THEN LIKELY SHIFT OFF TO THE EAST BY SATURDAY
AFTERNOON...THOUGH ADDITIONAL REDEVELOPMENT WILL BE POSSIBLE AS THE
WESTERN TROUGH CONTINUES TO PROVIDE LARGE SCALE SUPPORT AND ANOTHER
EMBEDDED DISTURBANCE QUICKLY FOLLOWS ON THE HEELS OF THE EARLIER DAY
WAVE. GIVEN THE GOOD PROSPECTS FOR HEAVY RAIN SOMEWHERE IN THE AREA
AND THE RISK OF FLOODING...WE HAVE DECIDED TO ISSUE A FLASH FLOOD
WATCH FOR THE ENTIRE AREA FROM MIDNIGHT TONIGHT THROUGH EARLY
SATURDAY AFTERNOON. ADDITIONAL FLOOD HEADLINES MAY BE POSSIBLE LATER
SATURDAY...DEPENDING ON HOW THINGS EVOLVE IN THE WAKE OF THE ROUND
OF CONVECTION EARLIER IN THE DAY.
IN ADDITION TO THE FLOOD RISK...INCREASING INSTABILITY AND LIFT MAY
SUPPORT A FEW STRONG/SEVERE STORMS LATE TONIGHT MOVING IN FROM THE
SOUTHWEST. THE PRIMARY RISK WITH THE STRONGEST STORMS WOULD BE LARGE
HAIL. THE SEVERE THREAT MAY REDEVELOP SATURDAY AFTERNOON...BUT THIS
WILL BE CONTINGENT ON HOW THE EARLIER DAY ACTIVITY EVOLVES AND HOW
MUCH HEATING CAN BE REALIZED.
TEMPERATURES WILL BE ON THE MILD SIDE TONIGHT AS MOIST SOUTHEASTERLY
FLOW STRENGTHENS. THE SOUTHERLY WINDS /ALONG WITH AT LEAST SOME
INSOLATION OVER THE WESTERN ZONES/ SHOULD SECURE AFTERNOON HIGHS ON
SATURDAY PEAKING IN THE 70S FOR MOST.
LONG TERM...
THE UPPER-LOW WILL MOVE SLOWLY ACROSS THE ROCKIES LATE SATURDAY
INTO SUNDAY. WITH ANOTHER DISTINCT SHORTWAVE ROTATING AROUND THE
LOW AND PASSING OVER THE AREA SATURDAY NIGHT INTO SUNDAY MORNING
IT IS LIKELY THAT WE WILL SEE AT LEAST SOME T-STORM ACTIVITY
CONTINUING ACROSS THE REGION THROUGH THE NIGHT. A VEERING LOW-LVL
JET SHOULD GUIDE THE ACTIVITY EAST INTO THE ROLLING PLAINS EARLY
SUNDAY MORNING. FOR THE REMAINDER OF SUNDAY...WE/LL LOOK FOR MORE
SUNSHINE AS DEEP-LAYER MOISTURE DECREASES. TEMPERATURES MAY EVEN
REACH 80F IN SOME LOCATIONS. THE MORNING GUIDANCE IS IN GOOD
AGREEMENT THAT A MID-LVL DRY PUNCH WILL WORK INTO THE SOUTH
PLAINS DURING THE DAY AS THE SHORTWAVE TROUGH AXIS PIVOTS INTO
THE PANHANDLES AND NORTH TEXAS. THIS IN TURN MAY HELP TO TIGHTEN
AND PUSH THE DRYLINE EAST...BUT COULD ALSO INCREASE THE POTENTIAL
INSTABILITY IN AREAS THAT RETAIN THE LOW- LEVEL MOISTURE. WE/LL
JUST HAVE TO SEE IF A DRYLINE BULGE DEVELOPS SOMEWHERE NEAR THE
CAPROCK EDGE AS THE MORNING GFS AND NAM RUNS SUGGEST...BUT IF
RECENT HISTORY IS ANY GUIDE...THE DRYLINE WILL LIKELY FAVOR A MORE
WESTWARD POSITION...SO WE/LL BE WATCHING THIS CLOSELY. ISOLATED TO
SCATTERED TSTM DEVELOPMENT IS EXPECTED IN THE VICINITY OF THE
DRYLINE SUNDAY AFTERNOON...LIKELY BRINGING A CHANCE OF SEVERE
WEATHER. LARGE-SCALE SUBSIDENCE FOLLOWING THE WAVE SUNDAY EVENING
SHOULD BRING A QUIET SUNDAY NIGHT AND START TO MEMORIAL DAY.
HOWEVER...THE NEXT SHORTWAVE WILL BE MOVING ACROSS AZ AND NM...AND
THE FORECAST AREA WILL LIKELY ALREADY BEGIN TO FEEL THE LIFT FROM
THIS SYSTEM BY MONDAY AFTERNOON. THIS WAVE MAY BE BETTER TIMED
WITH DIABATIC WARMING TO TAP INTO STRONGER INSTABILITY AND GIVE US
ANOTHER ROUND OF POTENTIALLY SEVERE AFTERNOON AND EVENING
T-STORMS. THE DRYLINE MAY ADVANCE INTO THE CENTRAL SOUTH PLAINS
SUNDAY AFTERNOON PROVIDING THE LOW-LVL FOCUS FOR CONVECTIVE
INITIATION...BUT AGAIN WE AREN/T VERY CONFIDENT IN DRYLINE
FORECASTS AT THIS POINT GIVEN ALL THE SOIL AND SURFACE MOISTURE.
WE MAY GET A CHANCE TO DESOGGIFY SOMEWHAT TUESDAY INTO WEDNESDAY
AS A BRIEF PERIOD OF LOW-AMPLITUDE RIDGING INTERRUPTS OUR SEQUENCE
OF WAVES. HOWEVER...WARMER TEMPS AND PLENTIFUL LOW-LVL MOISTURE
MAY BE SUFFICIENT TO GIN UP SOME DIURNAL CONVECTION EITHER OF
THOSE DAYS...WITH BETTER CHANCES ARRIVING LATE WED AS HEIGHT FALLS
OVERSPREAD THE REGION DOWNSTREAM OF THE NEXT TROUGH MOVING THROUGH
THE WEST. SOLID T-STORM CHANCES WILL LIKELY RESUME WITH THE
PASSAGE OF THIS TROUGH THURSDAY INTO FRIDAY...ALONG WITH A SLIGHT
COOL OFF.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 56 76 51 76 / 80 50 20 20
TULIA 58 73 55 76 / 80 60 30 30
PLAINVIEW 60 73 57 78 / 80 60 30 30
LEVELLAND 61 77 57 80 / 80 50 30 20
LUBBOCK 62 75 58 80 / 80 60 30 30
DENVER CITY 61 79 56 80 / 80 50 30 20
BROWNFIELD 62 76 58 81 / 80 60 30 20
CHILDRESS 62 74 62 80 / 60 80 40 40
SPUR 62 75 60 80 / 70 80 40 50
ASPERMONT 65 77 62 83 / 50 80 50 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM MIDNIGHT CDT TONIGHT THROUGH SATURDAY
AFTERNOON FOR TXZ021>044.
&&
$$
05/99
AREA FORECAST DISCUSSION
NWS AMARILLO TX
354 PM CDT THU MAY 21 2015
.SHORT TERM...
MUCH OF THE TEXAS PANHANDLE HAS SEEN NEARLY 48 HOURS OF OVERCAST SKY
CONDITIONS IN THE WAKE OF A COLD FRONT THAT PASSED THROUGH TUESDAY
EVENING. DESPITE THE DIFFERENTIAL ADVECTION PROFILE SEEN IN THE
12Z SOUNDING...MOISTURE WAS QUITE DEEP EVEN EXTENDING ABOVE THE
EAST-NORTHEASTERLY LOW LEVEL FLOW TO NEAR 700 MB WHERE FLOW WAS MORE
SOUTHWESTERLY. VISIBLE SATELLITE SHOWS SOME BREAKS IN THE NORTHEAST
TEXAS PANHANDLE AND THE EASTERN OKLAHOMA PANHANDLE THIS AFTERNOON
AND THIS HAS BEEN COINCIDENT WITH WARMER TEMPERATURES IN THE LOWER
60S. FURTHER WEST TEMPERATURES HAVE YET TO RISE OUT OF THE 50S AND
SO A SHORT TERM UPDATE WAS SENT TO LOWER TEMPERATURES SLIGHTLY. OUR
RECORD LOW MAX TEMPERATURE FOR TODAY IS 56 SET IN 1900. BASED ON
CURRENT TRENDS IN THE OBSERVATIONS AND EXAMINING THE DIURNAL CURVE
FROM YESTERDAY UNDER SIMILAR CONDITIONS...WE SHOULD REACH OR
SLIGHTLY EXCEED THIS TEMPERATURE THIS AFTERNOON.
SHORT RANGE GUIDANCE AGREES ON TIMING OF ONSET OF DEEPER SATURATION
SEEN ON ISENTROPIC SURFACES. THIS IS CAUSING SOME CONVECTION IN
EASTERN NEW MEXICO EXTENDING EAST TO JUST ACROSS THE TEXAS STATE
LINE...NEAR BOVINA. THIS ACTIVITY SHOULD CONTINUE MOVING
NORTHEASTWARD THIS AFTERNOON WHILE EXPANDING AS ASCENT FROM
APPROACHING LEAD WAVE STRENGTHENS. GIVEN THE SHORT RANGE MODEL
AGREEMENT ON THE LARGE SCALE BELIEVE THIS IS A FAIRLY GOOD CASE FOR
SUCCESS OF CONVECTION ALLOWING MODELS WITH TIMING AND COVERAGE OF
PRECIPITATION THIS EVENING AND INTO THE NIGHT. HOURLY PROBABILITY OF
PRECIPITATION GRIDS FOLLOW THESE MODELS INCLUDING THE HRRR AND
TTU-WRF FAIRLY CLOSELY. MOST OF THE PRECIPITATION SHOULD EXIT THE
AREA EARLY TOMORROW MORNING. SUBSIDENCE/MID LEVEL HEIGHT RISES IN
THE WAKE OF THE LEAD SHORTWAVE AND PRECEDING THE CLOSED UPPER LOW
SHOULD LIMIT OPPORTUNITY FOR CONVECTION TOMORROW AFTERNOON. HAVE
SIGNIFICANT REDUCED PRECIPITATION PROBABILITIES FOR TOMORROW
AFTERNOON. MODEL FORECAST SOUNDINGS REVEAL DIFFERENCES IN MODELS
WITH HOW MOIST THE LOW LEVELS ARE AND THIS HAS IMPLICATIONS FOR BOTH
CLOUD COVER AND TEMPERATURES. THE NAM HAS GENERALLY PERFORMED WELL
THE DAY FOLLOWING A NIGHTTIME CONVECTIVE EVENT RECENTLY SO GAVE IT
SOME CREDIT BUT TOOK A BLENDED APPROACH BETWEEN THE DRIER/WARMER NAM
AND THE MOIST/COOL GFS AND ECMWF. QPF GRIDS WERE ADJUSTED SLIGHTLY
AND DEVIATE ONLY SLIGHTLY FROM WPC GUIDANCE...MAINLY IN JUST A
TEMPORAL SENSE BUT WITH SLIGHTLY HIGHER AMOUNTS. TOTALS THROUGH
TOMORROW RANGE FROM AROUND A HALF INCH IN THE NORTHWEST TO NEAR AN
INCH IN THE SOUTHEAST.
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY
SPLIT FLOW UPPER AIR PATTERN WILL MAINTAIN A WET AND ACTIVE WEATHER
PATTERN FOR THE EXTENDED PERIOD AS A SERIES OF UPPER LEVEL
DISTURBANCES PASS ACROSS THE SOUTHERN PLAINS.
A PACIFIC UPPER LOW WILL MOVE ACROSS THE GREAT BASIN AREA FRIDAY
EVENING...WITH A LEAD SHORTWAVE EJECTING OUT OF THIS SYSTEM BEFORE
MOVING OVER THE REGION LATE FRIDAY NIGHT. LOW-LEVEL MOISTURE WILL
REMAIN PLENTIFUL COURTESY OF PERSISTENT SOUTHEAST UPSLOPE SURFACE FLOW
AND A LIFTING WARM FRONT. WITH THE DRYLINE REMAINING IN EASTERN NM
LARGE SCALE ASCENT WILL BE THE PRIMARY FOCUS FOR CONVECTION
INITIATION FRIDAY EVENING...WITH THE HIGHEST CHANCES FOR PRECIP
OCCURRING BETWEEN 06-12Z SATURDAY. HIGH PW VALUES...NEAR THE 99TH
PERCENTILE...WILL SUPPORT MODERATE TO HEAVY RAINFALL. THIS IN TURN
RAISES CONCERN FOR THE FLOODING POTENTIAL PARTICULARLY OVER THE
SOUTHEAST TEXAS PANHANDLE WHERE RAINFALL TOTALS OVER 2 INCHES
OCCURRED OVER THE PAST 3 DAYS AND SOILS ARE MORE CONDUCIVE TO
FLOODING. DID CONTEMPLATE EXPANDING THE CURRENT FLASH FLOOD WATCH
FURTHER WESTWARD GIVEN ALL THE RAIN THE SOUTHERN TEXAS PANHANDLE HAS
RECEIVED RECENTLY. DECIDED TO HOLD OFF ON EXPANDING THE WATCH AS
CONFIDENCE IS NOT HIGH ENOUGH THAT ENOUGH RAINFALL WILL RESULT IN
FLASH FLOODING.
THE UPPER LOW WILL MOVE INTO THE FOUR CORNERS REGION SATURDAY EVENING
AND LIFT SLOWLY TO THE NORTHEAST SUNDAY. SEVERAL UPPER LEVEL
SHORTWAVE TROUGHS WILL MAINTAIN A THREAT OF SHOWERS AND THUNDERSTORMS
THROUGH THE HOLIDAY WEEKEND. THE DRYLINE WILL MIX A BIT FURTHER
EASTWARD SUNDAY...WHICH WILL FOCUS STORM INITIATION GENERALLY OVER
THE EASTERN PANHANDLES. IN GENERAL NOT EXPECTING MUCH IN THE WAY OF
SEVERE WEATHER ALTHOUGH POSSIBLE IF THERE IS ENOUGH DAYTIME
DESTABILIZATION...SOME STRONG TO SEVERE STORMS WILL BE POSSIBLE.
MAY SEE A BRIEF BREAK IN THE RAIN EARLY NEXT WEEK ALTHOUGH WITH THE
MEDIUM RANGE MODELS IN DISAGREEMENT IN THE SPEED OF THE UPPER
TROUGH...HELD ONTO SLIGHT CHANCE POPS MEMORIAL DAY. DECENT LOW-LEVEL
MOISTURE IN PLACE AND ANOTHER UPPER DISTURBANCE MOVING THROUGH THE
FOUR CORNERS REGION CAN GENERATE MORE SHOWERS AND THUNDERSTORMS
MIDWEEK.
CLK
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 48 67 57 71 56 / 80 40 60 60 20
BEAVER OK 48 67 57 71 58 / 80 50 40 60 40
BOISE CITY OK 46 70 54 72 51 / 70 30 40 30 20
BORGER TX 50 68 59 72 59 / 80 50 50 50 30
BOYS RANCH TX 49 71 58 74 56 / 80 40 60 50 20
CANYON TX 48 67 57 72 55 / 70 40 60 50 20
CLARENDON TX 49 66 58 70 58 / 80 50 50 70 40
DALHART TX 46 70 54 73 53 / 70 30 50 50 20
GUYMON OK 47 69 57 72 56 / 80 50 40 50 20
HEREFORD TX 47 68 57 73 55 / 70 40 70 40 20
LIPSCOMB TX 49 65 58 69 59 / 80 50 40 70 40
PAMPA TX 47 64 56 69 57 / 80 50 50 60 40
SHAMROCK TX 51 65 59 69 59 / 80 50 50 70 50
WELLINGTON TX 53 67 61 71 61 / 80 50 50 70 50
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH FROM LATE FRIDAY NIGHT THROUGH LATE SATURDAY
NIGHT FOR THE FOLLOWING ZONES: ARMSTRONG...COLLINGSWORTH...
DONLEY...GRAY...WHEELER.
OK...NONE.
&&
$$
17/05
AREA FORECAST DISCUSSION
NWS EL PASO TX/SANTA TERESA NM
210 PM MDT THU MAY 21 2015
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE AREA THIS
AFTERNOON AND EVENING...INTERACTING WITH A STALLED OUT FRONTAL
BOUNDARY AND LOW LEVEL MOISTURE OVER SOUTH-CENTRAL NEW MEXICO AND
FAR WEST TEXAS. THIS WILL RESULT IN ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING THIS AFTERNOON EAST OF THE CONTINENTAL
DIVIDE...SPREADING INTO THE RIO GRANDE VALLEY BY EARLY EVENING. A
FEW STORMS WILL BE SEVERE...PRODUCING DAMAGING WIND AND LARGE
HAIL. DRY SOUTHWEST FLOW WILL PREVAIL THROUGH THE WEEKEND.
&&
.DISCUSSION...
MAIN CONCERN IS SEVERE WEATHER POTENTIAL THIS AFTERNOON AND
EVENING. AS IS OFTEN THE CASE...BACKDOOR COLD FRONT PUSHED FURTHER
WEST OVERNIGHT THAN ORIGINALLY PROGGED...AND LOW CLOUD COVER HAS
HELPED LIMIT THE EASTWARD RETROGRESSION. QUASI-STATIONARY FRONT
CURRENTLY EXTENDS FROM THE EAST SLOPES OF THE BLACK RANGE TO
RIGHT AROUND DEMING AND COLUMBUS. RADAR THIN LINE EXTENDS FROM
JUST SE OF COLUMBUS ESE TO SAMALAYUCA...AND THIS IS LIKELY THE
FRONT. FROM THERE IT IS LIKELY BANKED UP AGAINST HIGHER TERRAIN SW
OF THE RIO GRANDE.
MEANWHILE...SHORTWAVE TROUGH IS SHARPLY DEFINED ON WATER VAPOR
IMAGERY ENTERING FAR SW NEW MEXICO...SOME MID-LEVEL CLOUDS AND VIRGA
ASSOCIATED WITH THIS FEATURE ARE ALSO APPARENT ON VISIBLE
SATELLITE AND RADAR IMAGERY RESPECTIVELY.
JUST NOW STARTING TO SEE CONVECTION INITIATE ALONG THE BLACK RANGE
AND PARTS OF SIERRA COUNTY. EXPECT CELLS TO DEVELOP FURTHER TO THE
SOUTH WITHIN INSTABILITY PLUME ALONG THE FRONT IN THE NEXT HOUR.
SEVERAL WRF RUNS AND HRRR SEEM TO BE HANDLING THE SITUATION WELL
DUE TO WELL- DEFINED BOUNDARIES AND CLEAR UPPER LEVEL FORCING.
EXPECT STORMS TO LIGHT UP ALONG THE FRONT AND MOVE
EASTWARD...INITIALLY ALONG THE BLACK RANGE INTO EASTERN LUNA
COUNTY...THEN SHIFTING EASTWARD TOWARDS THE RIO GRANDE BETWEEN 4
PM AND 6 PM AS LOW CLOUDS CONTINUE TO BREAK UP AND DESTABILIZATION
OCCURS BEHIND THE FRONT.
EXCELLENT DEEP LAYER SHEAR IS PRESENT FOR ROTATING UPDRAFTS...WITH
0-6KM SHEAR AOA 60 KNOTS AND 40 KNOTS IN THE 0-3KM LAYER. WET BULB
ZERO VALUES AROUND 12KFT MSL SUGGEST LARGE HAIL POSSIBLE...BUT
MODEL SOUNDINGS INDICATE MID-LEVEL LAPSE RATES IN THE -10 TO -20 C
LAYER ARE NOT TERRIBLY STEEP...WHICH IS A LIMITING FACTOR. SFC-
BASED CAPE VALUES WILL GENERALLY RUN FROM 1000-1500 J/KG IN THE
MAIN INSTABILITY AXIS ALONG THE FRONT.
MAIN THREATS WILL BE DAMAGING WINDS...LARGE HAIL (BUT LIKELY ON
THE LOWER END OF SEVERE CRITERIA DUE TO LIMITED LAPSE RATES). LCL
HEIGHTS AROUND 7000 FT MSL ARE A LITTLE LOW FOR AROUND THESE
PARTS...BUT LOW-LEVEL SPEED SHEAR IN THE 0-1KM LAYER IS LIMITED.
STILL...A QUICK-SPINUP FUNNEL IS OUT OF THE QUESTION ESPECIALLY IN
RAPIDLY DEVELOPING CELLS EARLY ON.
PW VALUES AT OR AROUND AN INCH ALONG THE RIO GRANDE SUGGESTS HEAVY
DOWNPOURS POSSIBLE...BUT A STEADY STORM MOTION SHOULD LIMIT FLASH
FLOOD THREAT TO LOCALIZED/POOR DRAINAGE AREAS WHERE RAINFALL RATES
ARE MORE OF AN ISSUE.
EXPECT THUNDERSTORM THREAT WILL DIMINISH QUICKLY AFTER 10PM WITH
LACK OF UPPER LEVEL SUPPORT...BUT A FEW ISOLATED STORMS WILL
REMAIN POSSIBLE THROUGH THE NIGHT EAST OF THE RIO GRANDE.
LOW LEVEL MOISTURE WILL AGAIN PUSH WELL WEST OF THE RIO GRANDE
OVERNIGHT... MAINLY AIDED BY CONVECTIVE OUTFLOW...BUT IT WILL BE
RAZOR-THIN AND QUICKLY MIX OUT TO THE EAST. STILL...THE LOW LEVEL
MOISTURE WILL NOT BE FAR TO OUR EAST THROUGH THE WEEKEND...AND A
SPOT SHOWER OR THUNDERSTORM IS NOT OUT OF THE QUESTION IN FAR
EASTERN HUDSPETH OR OTERO COUNTIES.
ELSEWHERE...DRY SOUTHWEST FLOW WILL PREVAIL THROUGH THE WEEKEND AS
THE MAIN UPPER LOW OFF CALIFORNIA MOVES TO THE EAST. TEMPERATURES
WILL MAINLY BE IN THE LOWER AND MID-80S ACROSS THE LOWLANDS
THROUGH THE WEEKEND...WITH A WARM-UP TOWARDS THE MIDDLE OF NEXT WEEK.
SOUTHEAST LOW LEVEL FLOW MAY BRING THE THUNDERSTORM THREAT BACK TO
THE RIO GRANDE BY WEDNESDAY.
&&
.AVIATION...VALID 22/00Z-23/00Z...
BACKDOOR FRONT HAS PUSHED WESTWARD TO CONTINENTAL DIVIDE: TIL 06Z
WINDS 120-160/13G23KTS SCT-BKN040 SCT-BKN100-140 SCT-BKN200-250
ISOLD TO SCT AREAS BKN020 BKN040 OVC-70 3SM -TSRAGS. 06Z-15Z:
SCT040-060 SCT100-140 SCT 200-250 WINDS 120/10KTS...AFT 15Z:
FEW-SCT070 FEW-SCT150. WINDS 23015G25KTS. LGT TO MDT MECHANICAL
TURBC OVR/NR MTNS BLO 15K FT MSL.
&&
.FIRE WEATHER...
A SURGE OF MOISTURE FROM THE EAST WILL RESULT IN SCATTERED SHOWERS
AND THUNDERSTORMS TODAY AND TONIGHT GENERALLY EAST OF A TCS-DMN LINE.
A FEW OF STORMS WILL BE STRONG WITH LARGER HAIL AND WIND GUSTS UP TO
50 MPH. THE INCREASED CLOUDS WILL AND RAIN WILL KEEP TEMPERATURES
BELOW NORMAL FOR MOST AREAS TODAY. HOWEVER THE EXTREME SOUTHWEST
CORNER OF THE NMEX BOOT HEEL MAY SEE NEAR CRITICAL FIRE WX
CONDITIONS THIS AFTN IN A SMALL AREA NEAR/ON THE AZ BORDER BUT
GENERALLY NOT MEETING TIME REQUIREMENTS FOR RED FLAG. DRY AND WINDY
CONDITIONS WILL RETURN ON FRIDAY WITH WARMER TEMPERATURES EXPECTED.
RED FLAG CONDITIONS SHOULD BE MEET IN ZONE 11 AND NEAR RED FLAG IN
OTHER LOWLANDS. BREEZY TO WINDY CONDITIONS WILL CONTINUE THROUGH THE
WEEKEND AS A LOW PRESSURE SYSTEM PASSES NORTH OF THE LOCAL AREA. DRY
CONDITIONS WITH SEASONAL TEMPERATURES WILL OCCUR MEMORIAL DAY AND
THE FIRST PART OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
EL PASO 59 88 62 84 58 / 30 0 0 0 0
SIERRA BLANCA 57 85 61 82 53 / 40 10 10 10 0
LAS CRUCES 50 84 50 79 50 / 30 0 0 0 0
ALAMOGORDO 52 83 53 80 51 / 50 0 0 0 0
CLOUDCROFT 38 59 39 55 39 / 50 10 10 0 0
TRUTH OR CONSEQUENCES 53 80 50 77 49 / 30 0 0 0 0
SILVER CITY 44 75 43 66 43 / 0 0 0 0 0
DEMING 47 83 46 78 47 / 10 0 0 0 0
LORDSBURG 44 82 45 74 46 / 0 0 0 0 0
WEST EL PASO METRO 60 88 62 83 57 / 30 0 0 0 0
DELL CITY 51 85 56 82 51 / 50 10 10 0 0
FORT HANCOCK 59 90 63 87 56 / 30 0 0 0 0
LOMA LINDA 53 80 58 75 53 / 40 0 0 0 0
FABENS 56 89 59 85 55 / 30 0 0 0 0
SANTA TERESA 53 88 56 82 53 / 30 0 0 0 0
WHITE SANDS HQ 58 83 57 79 54 / 30 0 0 0 0
JORNADA RANGE 46 82 48 78 46 / 30 0 0 0 0
HATCH 51 83 49 78 48 / 30 0 0 0 0
COLUMBUS 53 81 52 77 51 / 0 0 0 0 0
OROGRANDE 55 84 57 80 54 / 40 0 0 0 0
MAYHILL 43 67 46 65 44 / 50 10 10 0 0
MESCALERO 41 69 42 66 42 / 50 10 10 0 0
TIMBERON 43 68 44 64 44 / 50 10 10 0 0
WINSTON 42 71 41 67 42 / 20 0 0 0 0
HILLSBORO 45 79 45 76 46 / 20 0 0 0 0
SPACEPORT 48 82 45 78 46 / 30 0 0 0 0
LAKE ROBERTS 43 73 41 66 41 / 10 0 0 0 0
HURLEY 42 75 42 69 43 / 0 0 0 0 0
CLIFF 43 79 43 73 44 / 0 0 0 0 0
MULE CREEK 38 76 35 71 38 / 0 0 0 0 0
FAYWOOD 45 76 44 71 45 / 10 0 0 0 0
ANIMAS 46 80 45 76 47 / 0 0 0 0 0
HACHITA 46 84 44 78 46 / 0 0 0 0 0
ANTELOPE WELLS 46 83 43 79 46 / 0 0 0 0 0
CLOVERDALE 46 76 43 73 45 / 0 0 0 0 0
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH FRIDAY EVENING
FOR NMZ111.
TX...NONE.
&&
$$
25-HARDIMAN / 20-NOVLAN
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1149 PM CDT Wed May 20 2015
.AVIATION...
/06Z TAFS/
Look for IFR to MVFR conditions to continue for the next 24 hours.
Models this cycle present little chance for improvement during the
next 24 hours, as winter-like stratus remains firmly in place
across West Central Texas. Showers and perhaps a few thunderstorms
will develop, as warm air glides up and over the unseasonably cool
air near the surface.
&&
.PREV DISCUSSION... /ISSUED 1056 PM CDT Wed May 20 2015/
UPDATE...
The threat of severe thunderstorms has diminished across West
Central Texas. Most thunderstorms have moved south of our
counties. The old remaining thunderstorm cluster is over our
Northwest Hill Country counties, and the threat there has evolved
into more of a heavy rain threat, with the potential for local
flash flooding. Thus, we have canceled Severe Thunderstorm Watch
192 for all counties.
PREV DISCUSSION... /ISSUED 627 PM CDT Wed May 20 2015/
AVIATION...
/00Z TAFS/
Look for very challenging flight weather to continue for the next
24 hours. A cold front continue to move slowly south toward our
Interstate 10 corridor. North of the front low -winter-like stratus
has covered much of West Central Texas. Expect some improvement
tomorrow afternoon. Otherwise, plan for IFR to MVFR ceilings to
dominate.
PREV DISCUSSION... /ISSUED 552 PM CDT Wed May 20 2015/
UPDATE...
Thunderstorms, some severe, will continue to develop along or near
the cold front this evening. The cold front now extends near a
line from Barnhart...to Eldorado...to Brady. After coordination
with the Storm Prediction Central...we have issued Severe
Thunderstorm Watch number 192, which is valid until midnight CDT
tonight, for counties along and south of a line from Mertzon to
Brady. The latest Zone package headlines this watch for the
appropriate counties.
PREV DISCUSSION... /ISSUED 350 PM CDT Wed May 20 2015/
SHORT TERM...
(Tonight and Thursday)
A rather strong cold front has moved south of a San Angelo to
Coleman line this afternoon, dropping temperatures into the upper
50s and lower 60s across the Big Country. Low clouds and cold
advection north of the front has greatly reduced instability,
limiting the potential for diurnal convection. Ahead of the front,
temperatures have warmed into the lower 80s with dewpoints hanging
in the mid/upper 60s. Modified RAP soundings indicate SBCAPE values
on the order of 2000-2500 J/kg in the warm sector with effective
shear values exceeding 35 kts. This will support organized
convection this afternoon and during the evening hours, with the
primary focus along and south of the front. The primary concern is
for large hail and damaging winds. However, a tornadic storm cannot
be ruled out in the vicinity of this boundary.
Right moving supercell vectors are from the west and northwest at 10
to 15 mph. This slow storm motion and the presence of the
aforementioned cold front will support the potential for locally
heavy rainfall along the I-10 corridor tonight. Additional storms
will be possible overnight as isentropic ascent develops over the
frontal zone. As the front moves south overnight and early Thursday,
rain chances are expected to diminish during the morning hours.
However, shortwave ridging aloft will be shifting to the east as a
strong shortwave trough moves across the southern Rockies.
Increasing large scale ascent will promote the development of
scattered showers and thunderstorms during the afternoon hours.
Fortunately, the severe weather potential is expected to remain low
on Thursday. Much cooler temperatures are anticipated tomorrow, with
highs in the 60s across most of the area.
Johnson
LONG TERM...
(Thursday night through next Wednesday)
The main focus is with the severe weather and heavy rainfall
possibility for the Memorial Day holiday weekend.
Increased chance and coverage of showers and thunderstorms
is expected across our area Thursday night, with the arrival
of a stronger shortwave in southwest flow aloft. With subsidence
and advection of some drier mid-level air in the wake of this
departing shortwave, will have reduced chances for showers and
thunderstorms on Friday.
An upper low will move northeast into southeastern Utah Friday
night, with an upper trough trailing from the low across the
Desert Southwest. The main chance for showers and thunderstorms
Friday night will be overnight, and across our northwestern
counties, with the possibility of a weak embedded disturbance
out ahead of the main trough lifting northeast into far west
or northwest Texas.
The aforementioned upper trough will move slowly east across
Arizona and New Mexico over the holiday weekend. Given the
forecast strength of this system, will have increased potential
for severe weather with stronger instability and increased
vertical shear. Carrying higher PoPs over the weekend with the
highest rain chance on Saturday night. Heavy rainfall will also
be possible with repeat convective activity and precipitable
water values at or above 1.5 inches across much of our area.
The upper trough is progged to eventually lift northeast across
Texas, but the 12Z GFS and ECMWF differ on the timing.
Following departure of this system, drier and warmer conditions
look to be in store for our area as heights build aloft. May
have another upper trough approach from the southwestern states
next Wednesday, but keeping PoPs below mention with the
uncertainty at this time.
19
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 57 66 58 78 67 / 50 40 60 50 40
San Angelo 60 68 61 81 67 / 60 40 60 30 30
Junction 65 72 65 82 68 / 70 50 50 30 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SEATTLE WA
330 PM PDT THU MAY 21 2015
.SYNOPSIS...SHOWERS AND THUNDERSTORMS ARE OVER THE MOUNTAINS THIS
AFTERNOON AND A FEW COULD SPREAD TO THE LOWLANDS THIS EVENING. LOW
CLOUDS ON THE COAST WILL PUSH INLAND OVERNIGHT. FRIDAY AND SATURDAY
WILL BE COOLER WITH A CHANCE OF SHOWERS OVER THE INTERIOR OF WESTERN
WASHINGTON AND THE CASCADES. A PATTERN OF MORNING CLOUDS WITH SOME
AFTERNOON SUNSHINE IS LIKELY NEXT WEEK WITH A CONTINUING CHANCE OF
SHOWERS IN THE MOUNTAINS.
&&
.SHORT TERM...SCATTERED SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS
THIS AFTERNOON MAY SPREAD TO PORTIONS OF THE LOWLANDS THIS EVENING.
THE HRRR CONTINUES TO SHOW THE BEST CHANCE OF SHOWERS FOR THE
LOWLANDS IS OVER SW WA. MARINE STRATUS ON THE COAST WILL SPREAD
INLAND OVERNIGHT AND MARINE AIR SHOULD CONTINUE TO PUSH INTO WRN WA
THROUGH FRIDAY FOR A COOLER DAY. A CHANCE OF SHOWERS MIGHT PERSIST
FRIDAY THROUGH SATURDAY AS A WEAK UPPER LOW DROPS OVER THE AREA.
HIGHS WILL BE IN THE 60S AND THE BEST CHANCE FOR SHOWERS WILL BE
OVER THE CASCADES.
.LONG TERM...ANOTHER WEAK UPPER LOW WILL REMAIN OVER THE REGION
SUNDAY THROUGH WEDNESDAY WITH CONTINUED MODERATE LOW LEVEL ONSHORE
FLOW. MOST DAYS SHOULD SEE MORNING CLOUDS WITH SOME AFTERNOON
SUNSHINE OVER THE INTERIOR. THE COAST WILL PROBABLY STAY CLOUDY AND
COOL EACH DAY. THERE WILL BE A CHANCE OF SHOWERS...MAINLY IN THE
MOUNTAINS EACH AFTERNOON AND EVENING HOURS. THE POSITION OF THE LOW
CHANGES FROM RUN TO RUN AND SO IT IS HARD TO SAY IF THE LOWLANDS
WILL SEE ANY SHOWERS...BUT THE NORTH CASCADES PROBABLY HAVE THE BEST
CHANCE OF SHOWERS AND COULD SEE A SOAKING RAIN OR TWO IF THE LOW
BRINGS MOISTURE WWD FROM EASTERN WA...WHICH SOME MODELS RUNS HAVE
SHOWN.
&&
.AVIATION...AN UPPER LOW OVER THE CENTRAL COAST OF BRITISH COLUMBIA
IS FORECAST TO SLOWLY DIG S THRU TONIGHT. THE FLOW ALOFT WILL
GENERALLY BE LIGHT SLY. THE AIR MASS WAS UNSTABLE OVER THE MTNS THIS
AFTERNOON. THERE IS A CHANCE THAT AN ISOLATED TSTM COULD DRIFT OVER
THE LOWLANDS LATE TODAY OR EARLY THIS EVENING. THE LOWLAND AREAS
THAT WILL HAVE THE GREATEST CHANCE WILL BE E OF A KSEA-KPLU LINE AND
S OF KOLM. THE RISK OF TSTMS SHOULD END BY 0600 UTC.
MEANWHILE...THE SFC ONSHORE PRES GRADIENT CONTINUED TO TIGHTEN
THIS AFTERNOON. THIS WILL TRANSLATE TO LOW CLOUDS ACROSS THE
INTERIOR LOWLANDS FRI MORNING. ANTICIPATE WIDESPREAD IFR CIGS BY
1200 UTC. THERE WILL ALSO BE AREAS OF 1-3SM BR OR -DZ BR ON THE
COAST AFTER 0600 UTC.
KSEA...VFR CONDITIONS ARE ANTICIPATED TIL 0900 UTC. AFTER 0900
UTC...LOOK FOR CIGS IN THE 1-2K FT RANGE TO DEVELOP OVER THE
TERMINAL. CIGS SHOULD SETTLE NEAR 010 BY 1200 UTC.
&&
.MARINE...
PERSISTENT HIGH PRES OFFSHORE WITH LOWER PRES INLAND WILL RESULT
IN CONTINUED ONSHORE FLOW OF VARYING STRENGTH THROUGH TUE.
MEANWHILE...THE ONSHORE PRES GRADIENT CONTINUED TO STRENGTHEN THIS
AFTERNOON. THIS COMBINED WITH A MODEST TEMPERATURE GRADIENT
BETWEEN THE COAST /IN THE MID 50S/ AND THE INTERIOR /IN THE 70S/
THIS AFTERNOON WILL LIKELY RESULT IN GALE FORCE WINDS OVER THE
CENTRAL U.S. STRAIT OF JUAN DE FUCA THIS EVENING.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...GALE WARNING IN EFFECT TIL 5 AM FRI FOR THE CENTRAL STRAIT
OF JUAN DE FUCA.
SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE COASTAL WATERS
FROM CAPE FLATTERY TO CAPE SHOALWATER FROM 10 NM OUT TO 60
NM AND THE EAST ENTRANCE TO THE STRAIT OF JUAN DE FUCA.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
323 PM CDT THU MAY 21 2015
.TONIGHT - CONFIDENCE...MEDIUM
DRY AND MILD WESTERLY FLOW WILL PERSIST INTO THE EARLY EVENING
HOURS. FRONTAL BOUNDARY THEN PROGGED TO SWEEP SOUTH AND SHIFT
WINDS TO THE NE. ALREADY SEEING SOME NORTHERLY 20 KNOT PLUS GUSTS
ACRS NRN WI WITH WEAK POST FRONTAL PRESSURE RISES VCNTY U.P. SO NE
GUSTINESS EXPECTED ESPECIALLY NEAR LAKE MICHIGAN. WILL LEAVE
MENTION OF A FEW SHRA IN PARTS OF THE ERN CWA THIS EVENING. KGRB
RADAR SHOWS A FEW SHRA POPPING UP WITHIN AGITATED CU FIELD VCNTY
FRONTAL BOUNDARY. HIGH PRESSURE SETTLES IN LATER IN THE NIGHT.
.FRIDAY - CONFIDENCE...HIGH
SURFACE HIGH PRESSURE EXPECTED TO DOMINATE WITH PLENTY OF SUNSHINE AND
LIGHT WIND REGIME. ONSHORE COMPONENT WILL KEEP THE EAST COOLER. 925
TEMPS RISE TO AROUND 9C IN THE EAST AND 14C IN THE WEST...SO EXPECT
A DECENT EAST/WEST GRADIENT IN TEMPS.
.SHORT TERM...FRIDAY NIGHT THROUGH SUNDAY NIGHT.
FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE HIGH
SURFACE HIGH CENTERED OVER LOWER MICHIGAN SHIFTS SLOWLY TO THE
SOUTHEAST AND EXPANDS. WARMING 850 MB TEMPS AS COLD POOL MOVES EAST
WITH DEPARTING SRN CANADIAN CLOSED LOW...AND 500 MB HEIGHTS SLOWLY
RISE AS DEEPENING TROUGH MOVES INTO WESTERN U.S. WILL SEE LOWS HOLD
IN THE UPPER 40S IN THE SW THIRD...WITH LOW TO MID 40S ELSEWHERE.
SOME 700 MB MOISTURE AND OMEGA MOVE ACROSS WESTERN WI SATURDAY
AFTERNOON...BUT STRONGER Q-VECTOR CONVERGENCE STAYS TO THE WEST WITH
MORE FOCUSED 850 MB WARM AIR ADVECTION AND LOWER CONDENSATION
PRESSURE DEFICITS. SOUNDINGS ARE ALSO DRY BELOW 5K FT REFLECTING
INFLUENCE OF LOBE OF SURFACE HIGH PRESSURE EXTENDING WESTWARD OVER
SRN WI FROM BROAD HIGH CENTERED OVER THE MID-ATLANTIC STATES. NO
MORE THAN SLIGHT POPS WARRANTED AND WILL KEEP LIMITED TO THE FAR NW.
SOME DIFFERENCES IN HOW WARM 925 MB TEMPS GET SO CONSENSUS HIGHS IN
THE LOWER 70S AWAY FROM LAKE MICHIGAN LOOK GOOD WITH UPPER 60S
LAKESIDE.
SATURDAY NIGHT...FORECAST CONFIDENCE HIGH
JET SHIFTS NWD WITH UPPER RIDGING DEVELOPING OVER CENTRAL SECTIONS
OF THE COUNTRY IN RESPONSE TO DEEP FULL-LATITUDE TROUGH DIGGING INTO
THE SW U.S. PCPN CHANCES ARE PREDICATED ON TIMING OF PRECURSOR SHORT
WAVES EJECTING AHEAD OF DEEP WESTERN U.S. TROUGH AND LIFTING TOWARD
THE WESTERN GREAT LAKES IN MOIST SLY FLOW.
FIRST SHORT WAVE APPROACHES...WITH TIMING DIFFERENCES CAUSING PCPN
CHANCES THROUGH 12Z SUNDAY TO RANGE FROM KEEPING THE ENTIRE CWA
DRY/12Z GFS/...TO BRINGING PCPN INTO THE WEST OR FAR SOUTH/NAM AND
12ZECMWF/...OR OVER ALL BUT THE FAR NORTH AND EAST/12Z CANADIAN.
WILL FOLLOW CONSENSUS POPS WHICH LIMITS CHANCE POPS TO THE SOUTH
CENTRAL AND SLIGHT CHANCE ELSEWHERE WITH LESS THAN 15 PCT IN THE FAR
SOUTHEAST. LOWS WILL HOLD IN THE 50S OVERNIGHT WITH RISING 925 MB
TEMPS
SUNDAY AND SUNDAY NIGHT...FORECAST CONFIDENCE MEDIUM
ALL MODELS SWING INITIAL SHORT WAVE ACROSS SRN WI SUNDAY
MORNING...WITH ANOTHER WARM ADVECTION SURGE APPROACHING THE FAR
SOUTH BY 00Z MONDAY. HIGHER RESOLUTION VERSIONS OF GFS AND NAM
INDICATE THERE WILL PROBABLY SEE A BREAK IN THE PCPN BETWEEN THESE
TWO ROUNDS...BUT MODEL TIMING UNCERTAINTY LEADS TO POPS ALL DAY IN
THE CONSENSUS POPS. BETTER POPS SUNDAY NIGHT WITH WARM ADVECTION
SURGE. HOPEFULLY LATER RUNS WILL LEAD TO BETTER RESOLUTION TO PCPN
TIMING.
IF BREAK IN PCPN IS LONG ENOUGH...AND A BIT OF SUN CAN POP
THROUGH...COULD SEE TEMPS RISE HIGHER THAN UPPER 60S TO LOWER 70S
WITH FORECAST 925 MB TEMPS. INSTABILITY IN SOUNDINGS NOT THAT
IMPRESSIVE SO WILL LIMIT CHANCES OF THUNDER. LOWS WILL ONLY COOL
INTO THE UPPER 50S TO AROUND 60 NEAR THE IL BORDER.
.LONG TERM...MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE MEDIUM
AN UNSETTLED AND WET PERIOD IN OVERALL SWLY MID TO UPPER LEVEL FLOW
AS WESTERN TROUGH MOVES OUT INTO THE PLAINS MONDAY...AND THEN
DAMPENS AS IT CROSSES THE UPPER MIDWEST TUESDAY AND IS ABSORBED INTO
A CLOSED LOW OVER HUDSON BAY. MOIST SRLY SURFACE FLOW CONTINUES AS
SURFACE LOW PASSES BY TO THE WEST AND NORTH OF THE STATE. GFS AND
ECMWF BRING ANOTHER SURGE OF MOISTURE WITH A SHORT WAVE TUESDAY
NIGHT...WITH THE GFS DEVELOPING A SURFACE LOW THAT MOVES RIGHT ACROSS
THE STATE WEDNESDAY. ECMWF DRIES AREA OUT WEDNESDAY INTO
THURSDAY...WITH ANOTHER WAVE MOVING IN FOR THURSDAY AFTERNOON/NIGHT.
GFS KEEPS AREA DRY ONCE PCPN ENDS WEDNESDAY EVENING. RESULT IS
CHANCE POPS THROUGH THE EXTENDED WITH BLENDED SOLUTION. LOOKING FOR
ABOVE NORMAL TEMPERATURES THROUGH THE EXTENDED.
&&
.AVIATION/00Z TAFS/...VFR THIS PERIOD WITH WESTERLY SURFACE FLOW
AHEAD OF FRONT DROPPING SOUTHWARD FROM NRN WI. PREFER THE DRIER LOOK
OF THE HRRR WITH RESPECT TO PRECIP COVERAGE. LATEST GUIDANCE
SUGGESTS FRONT DROPS THROUGH TAF SITES BETWEEN 01Z-03Z. BRIEF PERIOD
OF GUSTY NE WINDS POSSIBLE. HAVE ALSO KEPT THE EVENING POPS WITH
THIS FEATURE AS WELL. NAM/RAP SOUNDINGS SHOW LITTLE POTENTIAL FOR
POST FRONTAL MVFR CIGS. QUIET HIGH PRESSURE DOMINATES FOR FRIDAY.
&&
.MARINE...A COLD FRONT WILL RACE DOWN THE LAKE EARLY THIS
EVENING...REACHING SHEBOYGAN AROUND 7 PM AND KENOSHA BY 9-10PM THIS
EVENING. WINDS WILL SHIFT ABRUPTLY FROM WESTERLY TO NORTHEAST AND
MAY GUST TO AROUND 20KTS POST FROPA FOR A TIME BEFORE SETTLING BACK
DOWN.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/FRIDAY AND AVIATION/MARINE...COLLAR
FRIDAY NIGHT THROUGH THURSDAY...REM
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1015 AM CDT THU MAY 21 2015
.AVIATION/18Z TAFS/...VFR THIS PERIOD WITH WESTERLY SURFACE FLOW
AHEAD OF FRONT DROPPING SOUTHWARD FROM NRN WI. PREFER THE DRIER
LOOK OF THE HRRR WITH RESPECT TO PRECIP COVERAGE. LATEST GUIDANCE
SUGGESTS FRONT DROPS THROUGH TAF SITES BETWEEN 01Z-03Z. BRIEF
PERIOD OF GUSTY NE WINDS POSSIBLE. HAVE ALSO KEPT THE EVENING
POPS WITH THIS FEATURE AS WELL. NAM/RAP SOUNDINGS SHOW LITTLE
POTENTIAL FOR POST FRONTAL MVFR CIGS. QUIET HIGH PRESSURE
DOMINATES FOR FRIDAY.
PC
&&
.PREV DISCUSSION... /ISSUED 312 AM CDT THU MAY 21 2015/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.
MOST PLACES SHOULD START OUT SUNNY THIS MORNING AS CLOUDS EXIT
THE FAR SOUTHEAST. TEMPS WILL REBOUND INTO THE UPPER 60S TO AROUND
70 THIS AFTERNOON...AS A WARMER AIR MASS PUSHES IN AHEAD OF AN
APPROACHING TROF/COLD FRONT DROPPING IN FROM THE NORTH FOR LATE
THIS AFTERNOON AND EVENING.
THE TROF...OR BACK DOOR COLD FRONT...WILL BE TIMED DURING MAX
DIABATIC HEATING...COUPLED WITH FAIRLY COLD TEMPS ALOFT. NEARLY
ALL THE MODELS DEVELOP SOME SHOWERS...MAYBE EVEN A RUMBLE OF
THUNDER...OVER THE FOX VALLEY OF EAST CENTRAL WISCONSIN VERY LATE
THIS AFTERNOON AND DRIFT IT SOUTH ACROSS THE EASTERN HALF OF THE
FORECAST AREA THIS EVENING.
THE FRONT WILL ACCELERATE DOWN THE LAKE SHORE WHILE THE SHOWERS
GRADUALLY DIMINISH WITH THE LOSS OF HEATING. WILL EXPAND THE POPS
A BIT GIVEN THE CONSENSUS. ALSO EXPECT A COUPLE OF HOURS OF GUSTY
NORTHEAST WINDS NEAR THE LAKE SHORE AFTER THE FRONT HITS. THINGS
WILL THEN CALM DOWN VERY QUICKLY THEREAFTER.
SHORT TERM...FRIDAY THROUGH SATURDAY NIGHT...FORECAST CONFIDENCE
IS MEDIUM.
MODELS ARE IN GOOD AGREEMENT WITH HIGH PRESSURE SLIDING SOUTHEAST
ACROSS THE WESTERN GREAT LAKES REGION FRIDAY AND FRIDAY NIGHT. THE
HIGH WILL BRING QUIET WEATHER. COOL TEMPERATURES IN THE 50S TO
AROUND 60 ARE EXPECTED NEAR LAKE MICHIGAN FRIDAY...WITH ONSHORE
WINDS. MILDER MID TO UPPER 60S ARE EXPECTED WELL INLAND. LOWS
SHOULD FALL INTO THE 40S FRIDAY NIGHT...WITH LIGHT SOUTH WINDS.
MODELS CONTINUE TO SHOW DIFFERENCES WITH PRECIPITATION TRENDS
SATURDAY AND SATURDAY NIGHT. THE GFS TAKES THE 850 MB JET AND
POINTS IT INTO THE REGION LATER SATURDAY INTO SATURDAY NIGHT. THE
NAM/CANADIAN/ECMWF ALL KEEP THIS FEATURE WEST OF THE AREA DURING
THIS TIME. THE MODELS DO SLIDE A MODEST 500 MB VORTICITY MAXIMUM
EAST NORTHEAST THROUGH THE AREA SATURDAY AFTERNOON...WITH THE
BUILDING 500 MB RIDGE TO THE WEST OF THE REGION. STEADY WARM AIR
ADVECTION DEVELOPS OVER THE REGION SATURDAY INTO SATURDAY
NIGHT...WHICH BRINGS MORE MOISTURE AS WELL.
AREA FORECAST SOUNDINGS RESPOND WITH DEEPER MOISTURE PROFILES
SATURDAY NIGHT...THOUGH LITTLE ELEVATED CAPE EXISTS. FOR
NOW...WILL LEAVE IN LOW POPS IN THE FAR WEST SATURDAY
AFTERNOON...THEN SPREAD THEM INTO THE REST OF THE AREA SATURDAY
NIGHT. COULD SEE THIS PERIOD ENDING UP DRY...IF NAM/ECMWF/CANADIAN
MODELS VERIFY OVER THE AGGRESSIVE GFS.
LONG TERM...SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE IS
MEDIUM.
GFS/ECMWF CONTINUE TO DIFFER WITH TIMING OF PRECIPITATION SUNDAY.
THE GFS CONTINUES TO BE MORE AGGRESSIVE AND HAS QPF OVER THE AREA
WITH WARM AIR/MOISTURE ADVECTION CONTINUING. THE ECMWF PUSHES THE
FOCUSED WARM AIR ADVECTION INTO THE AREA SUNDAY AFTERNOON. AS
DISCUSSED EARLIER...THE ECMWF MAY BE MORE REALISTIC WITH ITS
SLOWER TIMING INTO THE AREA THAN THE AGGRESSIVE GFS. CONTINUED TO
USE CONSENSUS MODEL POPS FOR NOW ON SUNDAY...HIGHEST IN THE
SOUTHWEST COUNTIES.
THE GFS THEN KEEPS THE WARM FRONT WELL NORTH OF THE AREA SUNDAY
NIGHT INTO MONDAY...WITH THE ECMWF KEEPING IT OVER OR NEAR THE
AREA. BOTH MODELS DO SHOW SOUTHWEST FLOW AT 500 MB...WITH SEVERAL
VORTICITY MAXIMA PUSHING THROUGH. GFS VERY AGGRESSIVE WITH MEAN
LAYER CAPE/DEEP LAYER SHEAR MONDAY INTO MONDAY NIGHT...WHICH IS
PROBABLY OVERDONE. WILL CONTINUE WITH THE CONSENSUS MODEL POPS FOR
THIS PERIOD...AND KEEP THUNDER MENTION GOING. IF THE PRECIPITATION
OCCURS AS THE MODELS ARE SHOWING...WE SHOULD GET SOME BENEFICIAL
RAINFALL OVER THE AREA.
SOUTHWEST FLOW AT 500 MB LINGERS INTO THE MIDDLE OF THE WEEK ON
THE GFS/ECMWF...WITH SOUTH WINDS AT THE SURFACE HELPING KEEP WARM
AND MOIST CONDITIONS OVER THE AREA. WILL CONTINUE CONSENSUS POPS
FOR THIS PERIOD...AND KEPT THUNDER WORDING IN THIS PERIOD AS
WELL. MORE BENEFICIAL RAINFALL MAY OCCUR DURING THIS TIME.
AVIATION/12Z TAFS/...
VFR CONDITIONS EXPECTED DURING THE TAF PERIOD. THE MAIN
OPERATIONAL CONCERN IS LIKELY THE COLD FRONT THAT WILL BE TRACKING
SOUTH ACROSS THE AREA THIS EVENING. IT WILL BE ACCOMPANIED BY A
COUPLE HOUR PERIOD OF GUSTY NORTHEAST WINDS IN THE WAKE OF THE
FRONT FOR KMKE AND TO A WEAKER EXTENT AT KUES/KENW. A FEW SHOWERS
ARE ALSO POSSIBLE.
WINDS WILL SHIFT FROM WESTERLY TO NORTHEAST VERY ABRUPTLY AS THE
FRONT MOVES THROUGH. SOMETIMES THESE FRONTS WILL HAVE A BRIEF
PERIOD OF MVFR CIGS WITH THEM...BUT THEN CLEAR OUT VERY QUICKLY.
NOT SURE IF THAT WILL OCCUR IN THIS CASE. LOOK FOR THE WINDS TO
GUST TO AROUND 20KTS FOR AN HOUR OR SO...THEN SETTLE DOWN QUICKLY
THEREAFTER.
MARINE...A COLD FRONT WILL RACE DOWN THE LAKE EARLY THIS
EVENING...REACHING SHEBOYGAN AROUND 7 PM AND KENOSHA BY 9-10PM
THIS EVENING. WINDS WILL SHIFT ABRUPTLY FROM WESTERLY TO NORTHEAST
AND GUST TO AROUND 20KTS FOR A FEW HOURS BEFORE SETTLING BACK
DOWN.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
FRIDAY THROUGH WEDNESDAY...WOOD
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1250 AM MDT THU MAY 21 2015
.UPDATE...
ISSUED AT 913 PM MDT WED MAY 20 2015
NO MAJOR CHANGES FOR THE EVENING UPDATE. MOST OF THE LIGHT SHOWER
ACTIVITY FROM LATE AFTERNOON EARLY EVENING HAS DISSIPATED WITH THE
EXCEPTION OF SOME LIGHT TO MODERATE SHOWERS PERSISTING IN
SOUTHWESTERN CARBON COUNTY WY. AREAS OF DENSE FOG HAVE REDEVELOPED
OVER THE SUMMIT BETWEEN CHEYENNE AND LARAMIE...AND WILL CONTINUE
THE DENSE FOG ADVISORY THROUGH THURSDAY MORNING FOR THAT PART OF
THE SOUTH LARAMIE RANGE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 243 PM MDT WED MAY 20 2015
SFC ANALYSIS SHOWS THE HIGH PRESSURE CENTER LOCATED NEAR THE PINE
RIDGE WITH EAST TO NORTHEAST UPSLOPE AND PERSISTENT LOW CLOUDS
ACROSS THE REGION. IT HAS BEEN ANOTHER COOL DAY WITH TEMPS A GOOD
20 DEGREES BELOW NORMAL. EXPIRED THE DENSE FOG ADVISORY FOR THE
SOUTH LARAMIE RANGE WITH WYDOT OBS SHOWING MOST VIS ABOVE 1 MILE.
THE HRRR DOES INDICATE VIS DROPPING BELOW ONE HALF MILE OVER THE
SOUTH LARAMIE RANGE BY 03Z. THIS MAKES SENSE WITH SFC WINDS
REMAINING SOUTHEAST TO SOUTH OVERNIGHT. HAVE AREAS OF FOG FROM
BUFORD TO THE SUMMIT BY EARLY TONIGHT AND CONTINUING THROUGH
THURSDAY MORING. WILL LET THE EVENING/NIGHT SHIFT MONITOR THE OBS
AND WEBCAMS OVER THE SUMMIT...AS DENSE FOG IS DEFINITELY POSSIBLE IN
THIS PATTERN. SHOWERS DEVELOPING THIS AFTN ALONG AND WEST OF THE
LARAMIE RANGE HAVE BEEN STRUGGLING TO STAY TOGETHER IN THE VERY
STABLE AIRMASS OVER THE PLAINS. KEPT ISOLATED TO SCATTERED SHOWERS
CONFINED TO MAINLY THE LARAMIE RANGE AND POINTS WEST THROUGH THE
EVENING.
PATTERN DOES NOT CHANGE A WHOLE LOT BY THURSDAY. LOW CLOUDS WILL BE
STUBBORN TO CLEAR YET AGAIN WITH MOIST SOUTHEAST LLVL FLOW.
SLIGHTLY BETTER INSTABILITY WILL EXIST ALONG THE LARAMIE RANGE (CAPE
VALUES OF 100-200 J/KG) BUT THIS IS LARGELY DEPENDENT ON SOME AFTN
CLEARING...WHICH IS QUESTIONABLE. INSTABILITY REALLY DROPS OFF TO
THE EAST OF CHEYENNE SO EXPECTING STORMS TO REMAIN CONFINED IN
VICINITY OF THE LARAMIE RANGE. A SHORTWAVE WILL EJECT NORTHWARD
FROM COLORADO BY LATE THURS NIGHT AND FRI MORNING. WITH GOOD UPPER
LEVEL DIFLUENCE...MODELS HAVE BEEN CONSISTENT AT SHOWING WIDESPREAD
RAIN DEVELOPING OVER THE PLAINS BY FRI MORNING AND CONTINUING
THROUGH MUCH OF THE DAY. THIS IS LOOKING LIKE ANOTHER 0.25-0.75
INCH MAINLY STRATIFORM RAIN EVENT FOR LOCATIONS TO THE EAST OF THE
LARAMIE RANGE. DID LOWER HIGHS A FEW DEGREES ON FRI WITH HIGHS
STRUGGLING TO GET ABOVE THE MID 50S.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 243 PM MDT WED MAY 20 2015
THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST IS THE SEVERE
WEATHER POTENTIAL SATURDAY.
SATURDAY-SATURDAY NIGHT:
LATEST LOOK AT THE GEM/GEFS ENSEMBLES AND ECMWF ARE SHOWING
REALLY GOOD AGREEMENT IN THE TRACK OF THE UPPER LEVEL TROF THIS
WEEKEND. THE MODELS ARE ALSO IN AGREEMENT IN SHOWING THIS CLOSED
UPPER TROF OPENING UP IN NORTHWEST COLORADO AND SENDING ITS FIRST
PIECE OF ENERGY INTO OUR REGION SATURDAY. HOWEVER...THERE IS QUITE
A BIT OF STANDARD DEVIATION IN THE PLACEMENT OF THE SURFACE LOW
AROUND 00Z SUNDAY. THE MEAN ENSEMBLES ARE SHOWING THE SURFACE LOW
DEVELOPING IN EASTERN COLORADO. HOWEVER...THERE IS SOME HINTS THAT
THIS SURFACE LOW MAY ACTUALLY DEVELOP FURTHER NORTH IN NORTHEAST
COLORADO AND LIFT NORTHEAST THROUGH THE NEBRASKA PANHANDLE. IF
THIS SURFACE LOW DEVELOPS FURTHER NORTH...WE MAY SEE WARMER
TEMPERATURES AND HIGHER LOW LEVEL MOISTURE BEING DRAWN INTO AREAS
EAST OF THE LARAMIE WHICH WILL RESULT IN HIGHER INSTABILITY. THIS
COULD SET THE STAGE FOR SEVERE WEATHER IN AREAS EAST OF THE
LARAMIE RANGE SATURDAY AFTN/EVE...ESPECIALLY WITH 0-6KM SHEAR
VALUES APPROACHING 40 TO 50 KTS. ANOTHER CONCERN IS WHETHER OR NOT
WE WILL SEE LOW CLOUDS. AT THIS POINT...IT DOES NOT APPEAR THAT
THE LOW CLOUDS WILL BE PRESENT...BUT WE WILL HAVE TO SEE HOW THAT
EVOLVES. IF THE LOW CLOUDS ARE NOT PRESENT...TEMPERATURES SHOULD
BE ABLE TO CLIMB TO THE 60S.
SUNDAY-SUNDAY NIGHT:
THE MODELS ARE SHOWING THE MAIN UPPER LEVEL TROF MOVING INTO THE
AREA ON SUNDAY IN ITS WEAKENED STATE. THERE IS A LITTLE MORE
UNCERTAINTY ON HOW THIS TROF WILL IMPACT THE AREA ON SUNDAY
AFTERNOON INTO SUNDAY EVENING. AT THIS POINT...IT APPEARS LIKE THE
MAIN CONVECTION SHOW WILL BE ON SATURDAY AFTERNOON/EVENING.
HOWEVER...IF WE DO NOT SEE MANY STORMS DURING THAT TIME...THEN
SUNDAY MAY BE A DAY TO WATCH AS WELL. IF WE DO SEE WIDESPREAD
CONVECTION ON SATURDAY THEN SUNDAY CHANCES MAY BE MUCH SMALLER.
FOR NOW...WE WILL STAY WITH THE MODEL BLENDS FOR CONSISTENCY SAKE.
MONDAY-WEDNESDAY:
MODELS/ENSEMBLES ARE IN PRETTY GOOD AGREEMENT IN SHOWING THE UPPER
LEVEL RIDGE BUILDING OVER THE AREA AHEAD OF THE NEXT UPPER LEVEL
TROF MOVING INTO THE NORTHERN ROCKIES. THIS TROF WILL INDUCE UPPER
LEVEL DIFFLUENCE OVER THE AREA ON MONDAY AND TUESDAY WHICH COULD
SPARK SOME CONVECTION OVER THE MOUNTAINS WITH SOME OF THIS
CONVECTION POSSIBLY SPILLING OVER INTO THE PLAINS. OVERALL...IT
DOES NOT LOOK LIKE A REAL WET PATTERN...BUT WE CANNOT RULE OUT THE
AFTERNOON AND EVENING CONVECTION CHANCES OVER OUR AREA EITHER.
ALTHOUGH...TEMPERATURES WILL NOT BE TOO COOL WITH HIGHS CLIMBING
TO NEAR NORMAL READING WITH HIGHS MAINLY IN THE 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1246 AM MDT THU MAY 21 2015
WYOMING TAFS...MOUNTAINS MOSTLY OBSCURED. IFR PREVAILS IN FOG
AND LOW CLOUDS THROUGH MID MORNING...THEN VFR WITH CEILINGS AROUND
4000 FEET AGL. IN THE LATE AFTERNOON AND EARLY EVENING...ISOLATED
TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS PRODUCING
VISIBILITIES 4 TO 6 MILES WITH OCCASIONAL MVFR CEILINGS.
NEBRASKA TAFS...VFR AND OCCASIONAL MVFR PREVAIL THROUGH THE
PRE DAWN HOURS...EXCEPT AT SIDNEY WHERE IFR IN FOG AND LOW CLOUDS
PREVAILS FROM 10Z TO 15Z. AFTER MID MORNING...VFR PREVAILS WITH
CEILINGS FROM 3000 TO 5000 FEET AGL...THEN MVFR DEVELOPS AGAIN
AT SIDNEY THURSDAY EVENING.
&&
.FIRE WEATHER...
ISSUED AT 243 PM MDT WED MAY 20 2015
NO FIRE WEATHER CONCERNS THROUGH THE WEEKEND. TEMPERATURES WILL
REMAIN BELOW NORMAL AND AFTERNOON HUMIDITY VALUES WILL BE ABOVE 50
PERCENT. THE BEST CHANCE OF WIDESPREAD WETTING RAIN WILL COME
THURSDAY NIGHT AND FRIDAY.
&&
.HYDROLOGY...
ISSUED AT 243 PM MDT WED MAY 20 2015
LARAMIE RIVER AT FORT LARAMIE AND LARAMIE WILL CONTINUE TO RUN AT
RELATIVELY HIGH LEVELS THROUGH THIS WEEK...BUT AT THIS TIME IS
EXPECTED TO REMAIN WITHIN ITS BANKS. ANOTHER ROUND OF MODERATE TO
HEAVY RAINFALL IS EXPECTED OVER THE HIGH PLAINS AND POSSIBLY THE
LARAMIE VALLEY ON FRIDAY...SO WILL NEED TO CONTINUE TO MONITOR
THE LARAMIE RIVER THROUGH LATE THIS WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL 10 AM MDT THIS MORNING FOR WYZ116.
NE...NONE.
&&
$$
UPDATE...JG
SHORT TERM...ZF
LONG TERM...REC
AVIATION...RUBIN
FIRE WEATHER...ZF
HYDROLOGY...ZF
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
345 AM MDT SAT MAY 23 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 342 AM MDT SAT MAY 23 2015
AN UPPER LEVEL LOW OVER EASTERN UTAH WILL MOVE VERY SLOWLY EASTWARD
THRU TONIGHT. QG FIELDS SHOW MID LVL ASCENT THRU THE DAY INTO THE
EARLY EVENING HOURS. MEANWHILE AT THE SFC LOW PRES WILL EXTEND FM
THE CNTRL MTNS INTO SERN CO WITH MAINLY SELY LOW LVL FLOW ACROSS THE
PLAINS. WITH SELY LOW LVL FLOW A DENVER CYCLONE WILL PROBABLY DVLP
BY EARLY AFTN WITH A CONVERGENCE ZN OVER DENVER OR JUST TO THE EAST.
SHOULD SEE A GRADUAL INCREASE IN SHOWER AND TSTM DEVELOPMENT
ACROSS MUCH OF THE AREA BY MIDDAY WHICH WILL LINGER INTO THE EARLY
EVENING HOURS. AS FAR AS SVR POTENTIAL IT APPEARS HIGHS OVER NERN
CO MAY STAY MAINLY IN THE UPPER 50S TO LOWER 60S WITH CAPES AROUND
1000 J/KG EXCEPT POSSIBLY OVER LINCOLN COUNTY WHERE THEY MAY REACH
AROUND 1500 J/KG. THERE WILL BE DECENT SHEAR SO EXPECT A FEW SVR
STORMS OVER THE PLAINS WITH MARGINAL LARGE HAIL AND A FEW
TORNADOES DUE TO LOW LCLS. MEANWHILE THERE WILL BE SOME POTENTIAL
FOR HEAVY RAIN ACROSS THE PLAINS SO WILL ISSUE A FLASH FLOOD WATCH
DUE TO SATURATED SOILS AS A FEW LOCATIONS COULD SEE A FEW INCHES
OF RAIN IN LESS THAN AN HOUR.
FOR TONIGHT THE UPPER LEVEL TROUGH WILL BE CENTERED OVER WESTERN
COLORADO HOWEVER THE MID LVL ASCENT WILL GRADUALLY LIFT NORTH OF THE
AREA THIS EVENING WITH PCPN CHANCES DECREASING BY MIDNIGHT FM SW TO
NE. MAY SEE SOME FOG DVLP AFTER MIDNIGHT ACROSS THE PLAINS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 342 AM MDT SAT MAY 23 2015
M.O.T.S...MUCH OF THE SAME BEST DESCRIBES THE DAILY WEATHER CYCLE
ANTICIPATED DURING THE UPCOMING WEEK. LET`S START WITH THE LARGE
SCALE FLOW PATTERN. MODELS SHOW UPPER TROUGHS REPEATEDLY FORMING
OVER THE INTERMOUNTAIN WEST...AND A CONTINUOUS FEED OF SUBTROPICAL
AIR UP INTO THE DESERT SOUTHWEST OR ONSHORE IN SRN CALIFORNIA
THROUGH THE PERIOD. THE FIRST OF THESE TROUGHS IS FORECAST TO
TRACK OVER THE CENTRAL ROCKY MTN REGION ON SUNDAY BRINGING COOLER
TEMPERATURES...SCATTERED SHOWERS...ISOLATED T-STORMS AND LIGHTER
WINDS TO THE FORECAST AREA. PROGGED 6-HR PRECIP AMOUNTS ON THE
ORDER OF 1/10TH TO 3/10TH INCH BY EVENING. SHEAR AND INSTABILITY
NOT AS GREAT AS THE DAY BEFORE DUE TO WEAKER FLOW AND COOLER
TEMPS. SO SEVERE WEATHER RISK WILL BE MUCH LOWER. MODELS LIFT THIS
TROUGH NEWRD OVER THE NRN GREAT PLAINS BY MONDAY MORNING WHICH
POSITIONS NERN COLORADO IN A SOMEWHAT DRIER AND WARMER NWLY FLOW
TO START THE DAY. BUT BY AFTERNOON MOISTURE AND INSTABILITY RETURN
WITH A PASSING MID-LEVEL DISTURBANCE...RESULTING IN ANOTHER ROUND
OF SCATTERED SHOWERS AND ISOLATED T-STORMS MAINLY OVER AND NEAR
THE MTNS THROUGH THE EARLY EVENING HRS. ON TUESDAY MODELS SHOW
EVEN DRIER AND WARMER CONDITIONS WITH A PASSING SHORTWAVE RIDGE.
STILL STG DAYTIME HEATING AND RESIDUAL MOISTURE SHOULD BE ADEQUATE
TO PRODUCE SCATTERED AFTERNOON/EVENING SHOWERS/T-STORM IN THE HIGH
COUNTRY AND ISOLATED T-STORMS ON THE NEARBY PLAINS. NOTHING SEVERE
AND RAIN AMOUNTS SHOULD BE ON THE LIGHT SIDE.
BY WEDNESDAY...THE NEXT UPPER TROUGH SETTLES IN OVER THE GREAT
BASIN. AS IT DOES SO...STRENGTHENING SWLY FLOW OUT AHEAD OF IT PUMPS
MOIST AND UNSTABLE AIR UP FROM THE DESERT SOUTHWEST POTENTIALLY
RESULTING IN ANOTHER ROUND OF SOAKING SHOWERS AND THUNDERSTORMS
FOR PORTIONS OF NORTH-CENTRAL AND NORTHEAST COLORADO DURING THE
AFTERNOON AND EVENING HRS. SHOWER COVERAGE SHOULD BE MORE THAN
THE DAY BEFORE AND WITH MEAN LAYER SPECIFIC HUMIDITY ON THE
INCREASE...ODDS INCREASE FOR LOCALLY HEAVY RAINFALL OVER SWRN
PORTIONS OF THE CWA.
THURSDAY AND BEYOND...MODELS DIFFER SOME ON WHEN THE WESTERN
TROUGH SHIFTS EAST AND THE DEGREE OF IMPACT IT`LL HAVE ON THE
FORECAST AREA. MOST MODELS SHOW A COLD FRONT SLIPPING INTO NERN
COLORADO ERLY ON THURSDAY AND A FAIRLY MOIST UPSLOPE FLOW ON THE
PLAINS THROUGHOUT THE DAY. FOR NOW WILL HOLD OFF ON GOING HOG WILD
WITH PRECIP THURSDAY BUT WILL STILL HOLD ONTO A CHANCE OF
SHOWERS/T-STORMS FOR MOST AREAS...TOGETHER WITH SLIGHTLY COOLER
TEMPS. FRIDAY COULD POSSIBLY BE WETTER AND COOLER YET IF THE
MEDIUM RANGE MODELS ARE CORRECT...THE PRODUCT OF DEEP MOISTURE
WRAPPING AROUND A CLOSED LOW SPINNING OVER E-CNTRL COLORADO.
M.O.T.S.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 342 AM MDT SAT MAY 23 2015
A WK DENVER CYCLONE WAS OVER DENVER WHICH HAS KEPT THE BRUNT OF LOW
CLOUDS AND FOG TO THE NORTH OF DIA. THE HRRR AND RAP STILL SHOW
THAT SOME BRIEF DENSE FOG MAY DVLP FOR A FEW HOURS IN THE 10Z-14Z
TIME PERIOD SO WILL KEEP IN A TEMPO GROUP FOR LIFR. OTHERWISE
CEILINGS/VSBY WILL BE MVFR THRU 16Z. SHOULD BEGIN TO SEE
SHOWER/TSTM DEVELOPMENT BY 18Z WITH ACTIVITY GRADUALLY ENDING BY
23Z IF HRRR/RAP CAN BE BELIEVED. MAY SEE SOME SMALL HAIL AND GUSTY
WINDS WITH VSBY DOWN TO 3-5 MILES IN THE STRONGER STORMS. WINDS
WILL BE LIGHT AND VARIABLE EARLY THIS MORNING AND THEN MORE ENE BY
EARLY AFTN.
FOR TONIGHT THE SHOWER/TSTM THREAT SHOULD END BY 02Z WITH WINDS
BRIEFLY NWLY FOR A FEW HOURS BEFORE BECOMING LIGHT DRAINAGE BEFORE
MIDNIGHT. THERE COULD BE SOME FOG AND LOW CLOUDS LATE TONIGHT INTO
SUN MORNING.
&&
.HYDROLOGY...
ISSUED AT 342 AM MDT SAT MAY 23 2015
MAY SEE FROM 1 TO 2 INCHES OF RAIN ACROSS PORTIONS OF THE PLAINS
THIS AFTN INTO THE EARLY EVENING HOURS WITH SOME POTENTIAL FOR FLASH
FLOODING DUE TO SATURATED SOILS. IN THE MTNS AND FOOTHILLS AMOUNTS
WILL AVERAGE FROM ONE QUARTER TO ONE HALF INCH WITH ISOLATED AMOUNTS
UP TO AN INCH IN A FEW LOCATIONS.
THE CACHE LA POUDRE AND SOUTH PLATTE RIVERS REMAIN ABOVE FLOOD STAGE
IN WELD COUNTY AND ACROSS WESTERN PORTIONS OF MORGAN COUNTY...AND
WILL STAY THAT WAY FOR ANOTHER DAY OR SO.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH THIS EVENING FOR
COZ042-044>046-048>051.
&&
$$
SHORT TERM...RPK
LONG TERM...BAKER
AVIATION...RPK
HYDROLOGY...RPK
AREA FORECAST DISCUSSION
NWS POCATELLO ID
236 AM MDT SAT MAY 23 2015
.DISCUSSION...UPPER LOW CONTINUES ITS TRACK ACROSS SOUTHERN UTAH
WITH MOISTURE CONTINUING TO STREAM INTO THE AREA FROM WYOMING.
SHOWERS SEEN ON RADAR TRACKING SOUTHWESTWARD FROM IDAHO FALLS. NAM
AND HRRR SUGGEST FURTHER RAIN DEVELOPING ACROSS SOUTHEASTERN
HIGHLANDS LATER THIS MORNING. MODELS HAVE BEEN HITTING OUR
SOUTHEASTERN CORNER PRETTY HEAVILY WITH RAIN OVER THE PAST SEVERAL
RUNS. THE LOW WILL CONTINUE TO SLOWLY LIFT INTO COLORADO TONIGHT
AND INTO WYOMING TOMORROW MORNING. PRECIPITATION SHOULD BE FAIRLY
LIGHT AFTER THE HEAVIER BAND MOVES THROUGH THIS MORNING. WE MAY
FINALLY SEE A BREAK FROM THE WET WEATHER BY SUNDAY MORNING...A
TREND MORE FAVORED BY THE NAM THAN THE GFS...AS THE LOW CONTINUES
TO TRACK EASTWARD. BOTH MODELS INDICATE A WEAK UPPER RIDGE
BUILDING INTO THE AREA SUNDAY EVENING...BUT THE GFS SUGGESTS A
WETTER PATTERN FOR MEMORIAL DAY AS IT DRAWS MOISTURE IN AHEAD OF
ANOTHER DEVELOPING LOW MOVING INTO WESTERN WASHINGTON MONDAY
NIGHT. NAM PRODUCES AFTERNOON CONVECTION MAINLY OVER THE CENTRAL
MOUNTAINS. EXTENDED MODELS CONTINUE WITH TO SHOW A RETURN TO WET
WEATHER WHILE WE REMAIN IN THE PROXIMITY OF THE UPPER LOW THROUGH
THE MIDDLE OF NEXT WEEK. RIDGING MAY FINALLY TAKE HOLD AS WE HEAD
INTO NEXT WEEKEND...THOUGH NOT CONFIDENT ENOUGH TO GO COMPLETELY
DRY. HINSBERGER
&&
.AVIATION...BROAD AREA OF LIGHT PRECIPITATION WORKING THROUGH EAST
IDAHO EARLY THIS MORNING WITH SCATTERED SHOWERS ACROSS PORTIONS OF
THE CENTRAL MTNS. PRECIP EXPECTED TO CONTINUE TO WRAP AROUND UPPER
LOW INTO SOUTHERN HIGHLANDS THIS MORNING. NORTHERN AREAS COULD DRY
OUT EARLY BUT EXPECT PRECIP TO FILL IN ACROSS THE REGION ONCE AGAIN
THIS AFTERNOON. CEILINGS SHOULD REMAIN A MIX OF VFR/MVFR. PRECIP
LOOKS TO DISSIPATE LATE THIS EVENING WITH DRY CONDITIONS MOST AREAS
AFTER MIDNIGHT THOUGH CANT RULE OUT A FEW SHOWERS CONTINUING TOWARD
SUNRISE. DMH
&&
.FIRE WEATHER...A DEEP UPPER LOW IS EXPECTED TO SHIFT FROM THE
SOUTHERN GREAT BASIN THROUGH THE FOUR CORNERS REGION AND INTO THE
CENTRAL PLAINS BY LATE SUNDAY. MOISTURE WRAPPING AROUND THE LOW WILL
KEEP EAST IDAHO UNDER THE THREAT OF PRECIPITATION EACH DAY THROUGH
THE WEEKEND. ANOTHER SYSTEM IS EXPECTED TO MOVE SLOWLY THROUGH THE
PACIFIC NORTHWEST NEXT WEEK FOR CONTINUED THREAT OF SHOWERS EACH
DAY. DMH
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1211 AM MDT SAT MAY 23 2015
.SHORT TERM...(TONIGHT THROUGH SATURDAY AFTERNOON)
ISSUED AT 247 PM MDT FRI MAY 22 2015
LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS CLOSED LOW OVER
THE SW US...WITH A NEGATIVELY TILTED TROUGH CENTERED OVER THE
NEBRASKA PANHANDLE/NORTHEAST COLORADO. SATELLITE SHOWS CLEARING
BEGINS TO MOVE INTO THE SW PART OF THE CWA...WITH STRATUS/SHOWERS
TRANSITIONING NORTHWARDS. THUNDERSTORMS ARE ALREADY BEGINNING TO
FIRE ALONG PALMER DIVING ALONG NORTHERN EXTENT OF SURFACE LOW IN
EASTERN COLORADO.
REGARDING SEVERE THREAT THIS AFTERNOON THROUGH TONIGHT...WITH
CLEARING TAKING PLACE IN THE SW RAP AND OBJECTIVE ANALYSIS INDICATED
500-1500 J/KG OF SB CAPE ALREADY DEVELOPING...AND GUIDANCE WOULD
FAVOR THIS DEVELOPING INTO THE SW PART OF THE CWA (ASSOCIATED WITH
CLEARING. GOOD VEERING PROFILES ARE IN PLACE ALONG AND JUST NORTH OF
THE SURFACE LOW WHERE RAP IS HINTING AT HELICITY VALUES APPROACHING
250 M2/S2 BY 00Z. ORGANIZED SUPERCELL/TORNADO THREAT SEEMS TO BE
TIED TO THIS SURFACE LOW AND WOULD FAVOR THE SOUTHWEST PART OF OUR
CWA. DEEP SPEED SHEER CONTINUES OVERNIGHT AND GUIDANCE INDICATES
AROUND 1000 J/KG OF MU CAPE (POSSIBLY HIGHER IF NAM IS TO BE
TRUSTED). STRONG ISENTROPIC SIGNAL CONTINUES THROUGH THE NIGHTTIME
PERIOD...AND SEVERAL LOBES OF VORTICITY AND OMEGA ROTATE THROUGH
THE REGION. THIS SHOULD COMBINE TO CREATE
SHOWERS/THUNDERSTORMS...POSSIBLY A SEVERE HAIL THREAT IF WE SEE ANY
THUNDERSTORMS. NOT AS SURE ABOUT WIND THREAT CONSIDERING THE
PROFILES AND STABLE LOWER LEVELS.
FOG/STRATUS/DRIZZLE WILL BE POSSIBLE ALL NIGHT WITH GOOD BL MOISTURE
FLUX THROUGH SATURDAY MORNING...TRANSITIONING EASTWARD. WITH BETTER
SHOWER/THUNDERSTORM/DRIZZLE COVERAGE DENSE FOG MAY NOT BE AS MUCH OF
A CONCERN DUE TO THE INCREASE IN MIXING. WILL NEED TO MONITOR AS
LESS MIXING WOULD RESULT IN DENSE FOG DUE TO THE LONG FETCH
UPSLOPE/MAGNITUDE OF MOISTURE ADVECTION.
GUIDANCES SHOWS TWO DISTINCT SHORTWAVE TROUGHS SATURDAY
MORNING...ONE IN THE SOUTHERN PLAINS AND ANOTHER DEVELOPING INTO
NORTHERN COLORADO BY LATE AFTERNOON AS THE H3 JET BEGINS TO SHIFT
EASTWARD. THERE SEEMS TO BE A LULL IN ACTIVITY BETWEEN THESE
FEATURES LIKELY DUE TO SOME WEAK SUBSIDENCE...AND NAM IS REALLY
HITTING THIS DRY PERIOD HARDER COMPARED TO GFS/ECMWF. DECIDED OT
TIMING OUT THE LULL TO FAVOR LOWER POPS SAT MORNING...BEFORE
COVERAGE REDEVELOPS IN THE AFTERNOON. BETTER PRECIP SIGNAL IS AGAIN
IN EASTERN COLORADO BY MID AFTERNOON. CAPE PROFILES ARE MUCH MORE
ROBUST ACROSS THE MAJORITY OF THE CWA...AS WELL AS GOOD SHEER. AS A
RESULT WE WILL PROBABLY SEE A BETTER SEVERE THREAT SATURDAY
AFTERNOON THAN TODAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 247 PM MDT FRI MAY 22 2015
THE SLOW-MOVING UPPER LOW OVER UT/CO AT THE BEGINNING OF THE PERIOD
IS FORECAST TO LIFT NORTHEAST INTO THE DAKOTAS BY EARLY NEXT
WEEK...BUT NOT BEFORE SWINGING SEVERAL MORE SHORT WAVE TROUGHS
AROUND ITS PERIPHERY ACROSS THE FORECAST AREA. THE PATTERN WILL
BE SOMEWHAT LESS ACTIVE FOR THE MIDDLE OF THE WEEK WITH
THUNDERSTORM POTENTIAL A BIT MORE OF THE HIT-AND-MISS VARIETY
BEFORE ANOTHER TROUGH DEVELOPS IN THE WEST TOWARD THE END OF THE
WEEK. OVERALL...THE LONG RANGE PERIOD WILL BE ONE OF DECREASING
PRECIPITATION POTENTIAL WITH TEMPERATURES WARMING BACK TO SEASONAL
NORMS IN THE 70S/LOW 80S FOR HIGHS AND 50S FOR LOWS.
TO START THE EXTENDED PERIOD...THERE IS DECENT POTENTIAL FOR
STRONG TO SEVERE STORMS SATURDAY AFTERNOON-EVENING AS THE UPPER
LOW MOVES INTO WESTERN COLORADO AND A SURFACE DRYLINE SETS UP OVER
EC/SE COLORADO. A 100 KT 250 MB JET STREAK WILL BE RUNNING UP THE
EAST SIDE OF THE UPPER LOW ALONG THE C0-KS BORDER DURING PEAK
HEATING...AND WITH LOW LEVEL MOISTURE ALREADY IN PLACE...A ROUND
OF SEVERE STORMS SEEMS PROBABLE IN EASTERN COLORADO AND WESTERN
KANSAS. STORMS WILL MOVE QUICKLY NORTH INTO NEBRASKA DURING THE
EVENING.
SUNDAY AFTERNOON/NIGHT...THE TAIL END OF THE UPPER LOW/TROUGH
WILL FINALLY SWING THROUGH THE AREA SO CONTINUED CHANCE POPS AS A
RESULT. WEAK SUBSIDENCE BEHIND THIS FEATURE ON MONDAY WILL PROVIDE
A LITTLE RELIEF FROM THE ONSLAUGHT OF RECENT PRECIPITATION.
MID WEEK WILL BE CHARACTERIZED BY A QUASI ZONAL FLOW WITH A FEW
WEAK EMBEDDED TROUGH WHICH WILL KEEP SLIGHT CHANCE TO CHANCE POPS
FOR THUNDERSTORMS BUT OTHERWISE ACCOMPANIED BY TEMPERATURES MORE
TYPICAL OF LATE MAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1207 AM MDT SAT MAY 23 2015
EXPECT LIFR CONDITIONS DUE MAINLY TO LOW CEILINGS TO PERSIST
OVERNIGHT THROUGH ABOUT 14Z AT GLD AND ABOUT 17Z AT MCK WITH
SHOWERS IN THE VICINITY OF EACH SITE. CONDITIONS WILL IMPROVE TO
MVFR AT GLD AFTER 17Z AND REMAIN THERE AS THUNDERSTORMS DEVELOP
AND MOVE ACROSS THE AREA AFTER 00Z. AT MCK...EXPECT CONDITIONS TO
REMAIN IFR WITH LIFR CONDITIONS AND SHOWERS POSSIBLE AFTER 00Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...DLF
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS PADUCAH KY
412 AM CDT SAT MAY 23 2015
.UPDATE...
ISSUED AT 412 AM CDT SAT MAY 23 2015
UPDATE IS FOR THE AVIATION SECTION. ALSO ADDED SOME SPRINKLES INTO
THE NORTHERN 1/2 OF THE CWFA PER RETURNS ON KPAH/KVWX. MODELS NOT
HANDLING THIS WELL AT ALL. SOME EVIDENCE OF WEAK ISENTROPIC LIFT
310K...700-500MB WAA AND MOISTURE PER THE RAP MODEL.
&&
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 145 AM CDT SAT MAY 23 2015
WILL BE ONE MORE DRY DAY TODAY...THEN POPS FOR SHOWERS AND
THUNDERSTORMS WILL GRADUALLY BE ON THE INCREASE FROM WEST TO EAST
THE REST OF THE WEEKEND AS A MID LEVEL RIDGE MOVES EAST OF THE
AREA... ALLOWING FOR MOIST UNSETTLED SW FLOW ALOFT AHEAD OF A
BROAD TROF AND LOW OVER THE WESTERN U.S. THE ACTIVE PATTERN WILL
CONTINUE THROUGH MEMORIAL DAY AND MONDAY NIGHT...WITH CONVECTIVE
CHANCES CONTINUING. THROUGHOUT THE SHORT TERM...PRECIP CHANCES
WILL BE DRIVEN BY AREAS OF INSTABILITY AND WEAK IMPULSES MOVING
SW/NE ACROSS THE AREA. THERE IS LITTLE SURFACE OR BOUNDARY LAYER
FOCUS. USED A BLEND OF EXISTING NUMBERS AND LATEST BASE MODEL
OUTPUT FOR TEMPS.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 145 AM CDT SAT MAY 23 2015
LOW CONFIDENCE IN POPS/TIMING FOR THE EXTENDED.
AS USUAL TRIED TO RULE OUT POPS FOR THE LEAST LIKELY TIME
FRAMES...BUT WITH LOW CONFIDENCE. LI`S STAY NEGATIVE WITH CAPES
SOARING INTO THE 1K 1500 J/KG/2 RANGE AT TIMES COULD NOT RULE OUT
THUNDER WITH ANY OF THE POPS. HOWEVER THE FORECAST SOUNDING DO NOT
LOOK IMPRESSIVE FOR RAIN IN THE EXTENDED. HOWEVER WE ARE WARM
SECTORED AND THERE WILL BE SOME PERTURBATIONS ALOFT THAT MOVE
THROUGH AND WILL SERVE AS A KICKER FOR STORMS. THERE ARE LITTLE TO
NO SURFACE REFLECTIONS OTHER THAN MAYBE A WEAK TROUGH MID WEEK OR
OUTFLOW BOUNDARIES THAT COULD INITIATE THUNDERSTORMS. HOWEVER DO
NOT SEE ANY ORGANIZED SEVERE STORMS IN THE EXTENDED. BUT AS
AFOREMENTIONED WE WILL BE IN THE WARM SECTOR AND WILL LIKELY SEE
NEAR OR SLIGHTLY ABOVE NORMAL TEMPERATURES FROM MID WEEK INTO THE
WEEKEND. BY LATE IN THE WEEKEND THE MODELS ARE ADVERTISING A COLD
FRONT COULD BRING A LITTLE RELIEF FROM THE WARM AND HUMID
CONDITIONS.
&&
.AVIATION...
ISSUED AT 412 AM CDT SAT MAY 23 2015
MAINLY MID AND HIGH CLOUDS TODAY THROUGH TONIGHT WITH LIGHT SE
WINDS THE RULE. DERIVED CU RULE OFF THE MODELS NOT SHOWING MUCH IF
ANY LOWER CLOUD DEVELOPMENT. VFR CONDITIONS EXPECTED.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
148 AM EDT SAT MAY 23 2015
.SYNOPSIS...
PARTLY CLOUDY SKIES WILL GIVE WAY TO CLEAR SKIES OVERNIGHT. A
VERY COLD AIR MASS WILL BE OVER THE NORTH COUNTRY OVERNIGHT WITH
LOW TEMPERATURES BY DAYBREAK ON SATURDAY IN THE UPPER 20S TO LOWER
TO MID 30S. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD INTO THE
REGION ON SATURDAY AND REMAIN THROUGH SUNDAY. A WARM FRONT WILL
APPROACH THE NORTH COUNTRY ON MONDAY AND BRING A CHANCE OF RAIN
SHOWERS TO THE REGION.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
AS OF 1034 PM EDT FRIDAY...ISOLATED LATE RAIN SHOWERS (AND HIGHER
SUMMIT SNOW SHOWERS) CONTINUE TO DIMINISH ACROSS CENTRAL VT AT
0215Z...AND IR IMAGERY INDICATES CLEARING SKIES ACROSS THE ST.
LAWRENCE VALLEY AND POINTS NORTH AND WEST MOVING INTO THE NORTH
COUNTRY. STRONG LOW- LEVEL CAA CONTINUES AS WELL...WITH GUSTY NW
WINDS IN PLACE...BUT TEMPS ALREADY FALLING INTO THE MID-UPR 30S
ALONG THE INTL BORDER (36F AT NEWPORT VT AT 02Z). AS SUCH...FREEZE
WARNINGS LOOK ON TRACK WITH NO CHANGES MADE AT THIS TIME.
SLIGHTLY ABOVE FREEZING FOR EARLY AM LOWS EXPECTED IN THE FROST
ADVISORY AREA ACROSS THE CHAMPLAIN VALLEY (WITH MODERATING
INFLUENCE OF LAKE CHAMPLAIN AND STRONGER LOW-LEVEL MIXING). FROST
MAY ACTUALLY BE MITIGATED A BIT BY CONTINUED MODERATE WINDS...BUT
MORE SHELTERED LOCATIONS WILL SEE SOME PATCHY FROST FORMATION WITH
LOWS 33-36F IN THE CHAMPLAIN VALLEY. 850 MB TEMPERATURES ALREADY
DOWN TO -6C ALONG THE INTL BORDER PER LATEST RUC ANALYSIS...AND
SHOULD DROP TO AROUND -7 TO -8C DURING THE PRE- DAWN HOURS.
DEFINITELY A CHILLY NIGHT FOR LATE MAY...BUT TEMPERATURES WILL
BEGIN A STRONG MODERATING TREND BEGINNING ON SATURDAY.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 400 PM EDT FRIDAY...A WEAK RIDGE OF HIGH PRESSURE WILL
BUILD INTO THE REGION ON SATURDAY AND REMAIN THROUGH SUNDAY.
EXPECTING TEMPERATURES TO CLIMB INTO THE UPPER 50S TO 60S ON
SATURDAY AFTER A COLD START WITH SUNNY SKIES EXPECTED. NOT AS COLD
SATURDAY NIGHT WITH LOWS FROM THE UPPER 30S TO THE 40S.
TEMPERATURES WILL CLIMB INTO THE 70S ON SUNDAY WITH HIGHS IN THE
70S. A WARM FRONT WILL APPROACH THE SOUTHWEST SAINT LAWRENCE
VALLEY LATE SUNDAY NIGHT...SO HAVE GONE WITH SLIGHT CHANCE POPS
FOR RAIN SHOWERS FOR THE SOUTHWEST SAINT LAWRENCE VALLEY IN
NORTHERN NEW YORK.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 320 PM EDT FRIDAY...LARGE SCALE PATTERN WILL FEATURE
DEVELOPING MID/UPPER LEVEL RIDGE ACROSS THE EASTERN CONUS BY
MIDWEEK. THIS SYNOPTIC SCALE SETUP WILL RESULT IN MUCH ABOVE
NORMAL TEMPS AND DAILY CHANCES FOR AFTERNOON/EVENING
SHOWERS/STORMS. NO WIDESPREAD WETTING RAIN EVENTS ARE ANTICIPATED
THROUGH THE MIDDLE OF NEXT WEEK. HAVE CONTINUED TO MENTION CHC TO
LOW LIKELY POPS MONDAY AFTN INTO TUESDAY...ASSOCIATED WITH SFC
WARM FRNT. THIS FEATURE WILL HAVE GOOD 5H VORT TRAVELING FROM NW
TO SE ACROSS OUR REGION...WHILE A RIBBON OF ENHANCED 850 TO 500MB
RH MOVES FROM SOUTHWEST TO NORTHEAST. STILL SOME TIMING
DIFFERENCES BETWEEN THE GFS/EURO...BUT OVERALL IDEA OF A PERIOD
OF RAIN SHOWERS LOOKS GOOD. QPF WILL GENERALLY BE <0.25 FOR THIS
WARM FRONT FEATURE.
FOR TUESDAY THROUGH FRIDAY OF NEXT WEEK OUR CWA IS WELL
ESTABLISHED IN THE WARM SECTOR...AS RIBBON OF ENHANCED MID LVL
MOISTURE AND ASSOCIATED VORTS LIFT NORTH OF OUR REGION. PROGGED
925MB TEMPS RANGE BTWN 18C AND 22C DURING THIS PERIOD...SUPPORTS HIGHS
WELL INTO THE 80S WITH MAYBE A FEW READINGS NEAR 90 IN THE
CHAMPLAIN AND SAINT LAWRENCE VALLEYS...ESPECIALLY GIVEN DRY SFC
CONDITIONS. THE LACK OF FORCING AND DEEP LAYER MOISTURE WILL LIMIT
AREAL COVERAGE/INTENSITY OF STORMS...ALONG WITH AN ORGANIZED
CONVECTION. THINKING DAILY AIRMASS TYPE STORMS WILL BE
POSSIBLE...ESPECIALLY ACROSS THE HIGHER TRRN DURING THE PEAK
SURFACE HEATING. DAILY MAX CAPE VALUES RANGE BTWN 800 AND 1500
J/KG WITH SHEAR PROFILES SUPPORTING PULSE TYPE STORMS DURING THE
WEDS THRU FRIDAY TIME PERIOD. OTHERWISE...BETTER CHANCES FOR
STORMS ARRIVES NEXT WEEKEND ASSOCIATED WITH A COLD FRONT.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...VFR EXPECTED THROUGH THE PERIOD. SCT-BKN
5000-8000 FOOT CLOUD DECK CONTNIUES TO DISSIPATE BUT STILL HANGING
IN A BIT WITH NW UPSLOPE FLOW ACROSS VT. EARLY THIS MORNING...GRADUALLY
DISSIPATES OVERNIGHT LEADING TO CLEAR SKIES AT ALL TAF SITES AND
CONTINUES THROUGH TODAY WITH ONLY SOME SCATTERED MID LEVEL CLOUDS
MOVING IN LATER TODAY AND INCREASING TO BKN SAT NGT/SUN MRNG.
NORTHWEST WINDS 5-10 KNOTS EARLY THIS MORNING AND WEST/NORTHWEST
THIS MORNING TO 8-12 KNOTS WITH GUSTS 15-22 KNOTS...HIGHEST MPV.
WINDS TURN WEST/SOUTHWEST SATURDAY AFTERNOON WITH GUSTS 15-25
KNOTS...HIGHEST AT MSS SLOWLY DIMINSHING TONIGHT.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...VFR CONDITIONS CONTINUE
FOR SUNDAY INTO MONDAY...BEFORE A WEAK WARM FRONT WILL PRODUCE A
PERIOD OF LIGHT RAIN SHOWERS ON MONDAY AFTN INTO TUESDAY. A PERIOD
OF MVFR CIGS WILL BE POSSIBLE...ESPECIALLY IN THE MOUNTAINS. THE
CHANCES FOR AFTERNOON SHOWERS AND THUNDERSTORMS WILL CONTINUE FOR
WEDS...WITH BRIEF MVFR CIGS/VIS IN THE HEAVIER STORMS...MAINLY
DURING THE PEAK HEATING HOURS.
&&
.FIRE WEATHER...
A VERY DRY PERIOD CONTINUES ACROSS OUR REGION WITH MANY LOCATIONS
4 TO 6 INCHES BELOW NORMAL PRECIPITATION YEAR TO DATE. THE LATEST
US DROUGHT MONITOR HAS THE SAINT LAWRENCE VALLEY AND PARTS OF
SOUTHERN/CENTRAL VERMONT IN MODERATE DROUGHT CONDITIONS WITH
ABNORMALLY DRY ELSEWHERE. THESE DRY CONDITIONS HAVE PRODUCED VERY
DRY DEAD FUELS PER COORDINATION WITH VERMONT DEPT OF FOREST, PARK,
AND RECREATION. THESE DRY FUELS COMBINED WITH BREEZY SOUTHWEST TO
WEST WINDS SATURDAY AND MINIMUM AFTERNOON RELATIVE HUMIDITY VALUES
BETWEEN 17 AND 25% WILL INCREASE FIRE WEATHER CONCERNS. THE
STRONGEST WINDS WILL OCCUR BETWEEN NOON AND 7 PM...WHILE RH`S
WILL BE THE LOWEST BETWEEN 2 PM AND 6 PM ON SATURDAY. LOCALIZED
WIND GUSTS BETWEEN 20 AND 25 MPH WILL BE POSSIBLE IN THE SOUTHWEST
TO NORTHEAST ALIGNED SAINT LAWRENCE VALLEY AND PARTS OF CENTRAL
AND EASTERN VERMONT. GIVEN THE EXPECTED WEATHER CONDITIONS AND
VERY DRY FUELS...WE WILL ISSUE AN SPECIAL WEATHER STATEMENT TO
HIGHLIGHT THE FIRE WEATHER CONCERN...AS WINDS ARE MARGINAL AND
KEETCH BYRAM DROUGHT INDEX IS < 300 ACROSS OUR REGION.
HOWEVER...GIVEN THE CONDITIONS ABOVE ANY FIRES THAT DO OCCUR COULD
SPREAD QUICKLY...BURN INTENSELY AND BE DIFFICULT TO CONTAIN ON
SATURDAY.
&&
.MARINE...
AS OF 306 PM EDT FRIDAY...A LAKE WIND ADVISORY IS IN EFFECT FOR
LAKE CHAMPLAIN TONIGHT. NORTHWEST WINDS HAVE GENERALLY BEEN IN THE
10 TO 20 KNOT RANGE. STRENGTHENING PRESSURE GRADIENT SHOULD BE
ABLE TO PUSH LAKE WINDS TO LAKE WIND ADVISORY CRITERIA, IN THE 15
TO 25 KNOT RANGE, THROUGH AT LEAST THE FIRST HALF OF TONIGHT.
THEREAFTER, A SLACKENING PRESSURE GRADIENT SHOULD ALLOW FOR LAKE
WINDS TO SUBSIDE UNDER CRITERIA TOWARDS THE MORNING HOURS. EXPECT
WAVES TO BE IN THE 1 TO 3 FOOT RANGE WITH A MODERATE CHOP. HIGHEST
WAVES WILL TEND TO BE IN AREAS EXPOSED TO THE NORTH.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR VTZ003-004-
006>008-010-012-016>019.
FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR VTZ002-005-009-
011.
NY...FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR NYZ026-027-
029>031-034-087.
FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NYZ028-035.
&&
$$
SYNOPSIS...WGH
NEAR TERM...BANACOS/WGH
SHORT TERM...WGH
LONG TERM...TABER
AVIATION...MUCCILLI/SLW
FIRE WEATHER...TABER
MARINE...LOCONTO
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
336 AM CDT SAT MAY 23 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 327 AM CDT SAT MAY 23 2015
ISSUES WILL BE HOW FAR AND WHEN WILL THE PRECIP SPREAD NORTH THE
NEXT FEW DAYS. LARGER UPPER TROUGH OVER UTAH/N ARIZONA THIS
MORNING. THIS WILL SLOWLY MOVE EAST THE NEXT FEW DAYS..AS MOISTURE
CONTINUES TO MOVE NORTH. THE NORTHERN EDGE OF HIGH LEVEL CLOUD
COVER WILL SPREAD OVER THE AREA TODAY WITH SOME MID CLOUDS IN THE
SRN FCST AREA THIS AFTN. OF INTEREST IS A SMALL AREA OF SHOWERS IN
THE SIOUX FALLS AREA. HRRR AND A FEW OTHER SHORT RANGE MODELS DO
BRING A FEW SPITS OF PRECIP NORTHEAST INTO WCNTRL MN (ALEX-ST
CLOUD AREA) LATE MORNING INTO EARLY AFTN. TO BLEND WITH WFO MPX I
DID INSERT A FEW SPRINKLES IN OTTER TAIL AND WADENA COUNTIES LATE
MORNING INTO MID AFTN. BASED ON MOISTURE MOVING NORTH ANY SHOWERS
WILL NOT REACH THE SD/ND BORDER AREA TIL LATE THIS AFTN AND
TRIMMED POPS ACCORDINGLY FOR TODAY. TONIGHT WILL SEE A SHOWER RICK
IN THE SOUTH BUT STUBBORN HIGH PRESSURE TO THE NORTH ALONG THE
CANADIAN BORDER WILL REMAIN IN PLACE SLOWING DOWN ANY NORTHWARD
ADVANCEMENT OF MOISTURE.
SUNDAY WILL SEE DEEPER MOISTURE START TO MOVE INTO SE ND AND THEN
SPREAD NORTH DURING THE DAY. THUS HIGHER POPS...MOSTLY SOUTHERN
FCST AREA. GFS REMAINS A BIT FASTER THAN ECMWF/GEM WHICH KEEP
DVL-GFK AREA DRY THRU SUN EVE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT MAY 23 2015
RAIN CHANCES SPREAD NORTH SUN NIGHT WITH HIGH RAIN CHANCES MONDAY
AS UPPER TROUGH AND SFC LOW MOVE FROM SOUTHERN SD INTO CNTRL/SRN
MN. HIGH PRESSURE DOES REMAIN OVER SOUTHERN MANITOBA AND SOME
MODELS WANT TO KEEP FAR NW FCST AREA DRY EVEN MONDAY. AT THIS TIME
WENT WITH SUPERBLEND OF MODELS AND IDEA OF CATEGORIAL POPS FOR
SHOWERS MONDAY SE 2/3 OF THE FCST AREA. SOME WEAK
INSTABILITY...BUT VERY WEAK...SO DID KEEP SLIGHT CHANCE OF THUNDER
SUN NIGHT THRU MON IN THE GRIDS. PRECIP BEGINS TO MOVE EAST MON
NIGHT. AS FOR HOW MUCH RAINFALL....MOST AREAS IN THE ONE HALF TO
THREE QUARTERS INCH RANGE GFK SOUTH AND EAST AND LESS NORTHWEST.
FOR TUESDAY THROUGH FRIDAY...
NOT A LOT OF AGREEMENT AMONG MODELS ALTHOUGH THEY DO ALL SHOW THE
POTENTIAL FOR THUNDERSTORM ACTIVITY. UPPER FEATURES BECOME OUT OF
PHASE WHEN COMPARING ECMWF AND GFS...UNCHANGED FROM YESTERDAY`S
SOLUTION. ECMWF HAS LONGER WAVES WITH MORE OF A SOUTHWEST FLOW MID
WEEK WHILE GFS HANGS ON TO A DIGGING SHORTWAVE NORTH OF THE BORDER
WITH MORE OF A ZONAL FLOW OVER THE NORTHERN PLAINS. AMOUNT OF
MOISTURE RETURN WILL BE KEY TO COVERAGE AND INTENSITY OF STORMS.
LATEST EXTENDED SUPERBLEND SOLUTION CONTINUES WITH POPS COVERING
MOST OF THE FORECAST AREA MOST OF THE TIME...ONLY ADJUSTMENT WAS TO
SMOOTH OUT MINUTE AREAS OF PCPN/NO PCPN WITHIN THE FGF CWA.
TEMPERATURES WILL BE NEAR NORMAL VALUES WITH DAYTIME HIGHS MOSTLY IN
THE 70S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1120 PM CDT FRI MAY 22 2015
MAINLY FAIR SKIES AND LIGHT SOUTHERLY WINDS THROUGH THE OVERNIGHT
AND EARLY MORNING HOURS. INCREASING VFR CIGS INTO SOUTHEASTERN ND
AND WEST CENTRAL MN BY 18Z... WITH SCT VFR CIGS AND VSBYS IN RAIN
SHOWERS AND ISOLD TSTMS AFT 20Z... MAINLY ACROSS THE SOUTHERN FA.
SOUTHERLY WINDS GUSTING 10 TO 15 KTS FROM MID MORNING TIL SUNSET.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...RIDDLE
LONG TERM...WJB/RIDDLE
AVIATION...GUST
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1128 PM CDT FRI MAY 22 2015
.DISCUSSION...
UPDATED FOR 06Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 842 PM CDT FRI MAY 22 2015/
UPDATE...
SHOWERS THAT DEVELOPED OVER EASTERN OKLAHOMA THIS AFTERNOON
CONTINUE TO PUSH EAST ACROSS ARKANSAS. LATEST HRRR SHOWS THAT THE
SHOWERS MAY SKIRT PORTIONS OF EASTERN ARKANSAS DURING THE EARLY
MORNING HOURS BEFORE DYING OUT. WILL UPDATE TO ADD 20 POPS. IN
ADDITION BLOW OFF HIGH CLOUDS FROM THIS SHOWER ACTIVITY CURRENTLY
COVERS MUCH OF THE MIDSOUTH. WILL ALSO UPDATE TO BUMP UP SKY COVER
TO MOSTLY CLOUDY FOR AT LEAST THE NORTHWEST HALF OF THE CWA DURING
THE OVERNIGHT HOURS. THE CLOUDS MAY KEEP TEMPERATURES WARMER THAN
EXPECTED OVER AT LEAST WEST TENNESSEE NEAR THE TENNESSEE RIVER.
WILL WAIT FOR ONE MORE OB BEFORE DECIDING IF LOWS NEED TO BE
RAISED IN THAT PARTICULAR HOUR.
KRM
DISCUSSION... /ISSUED 301 PM CDT FRI MAY 22 2015/
SKIES REMAIN MOSTLY SUNNY ACROSS THE FORECAST AREA THIS AFTERNOON
WITH TEMPERATURES IN THE UPPER 60S TO LOWER 70S. HIGH PRESSURE WAS
CENTERED OVER WESTERN KENTUCKY THIS AFTERNOON. THIS HIGH WILL MOVE
EAST OF THE REGION TONIGHT. TEMPERATURES WILL NOT BE NEARLY AS
CHILLY AS THIS MORNING WITH LOWS SATURDAY MORNING MAINLY IN THE
50S.
ON SATURDAY...WINDS WILL START TO BECOME MORE SOUTHERLY WHICH WILL
BRING WARMER AND MORE HUMID AIR INTO THE REGION. TEMPERATURES WILL
BE CLOSER TO NORMAL LEVELS WITH HIGHS MAINLY IN THE LOWER 80S. BY
SATURDAY NIGHT A WARM FRONT WILL START TO LIFT NORTH THROUGH THE
SOUTHERN PLAINS AND MUCH OF ARKANSAS. SOME THUNDERSTORMS ARE
EXPECTED TO DEVELOP ALONG AND AHEAD OF THE WARM FRONT AND SOME OF
THIS ACTIVITY MAY REACH WESTERN SECTIONS OF THE FORECAST AREA.
ON SUNDAY...A COLD FRONT WILL BE MOVING INTO THE SOUTHERN PLAINS.
THUNDERSTORMS ARE EXPECTED TO FORM AHEAD OF THE FRONT AND SOME OF
THIS ACTIVITY MAY MOVE INTO THE FORECAST AREA WITH THE BEST CHANCE
OF RAIN OVER AREAS WEST OF THE MISSISSIPPI RIVER. TEMPERATURES
WILL BE A LITTLE WARMER WITH HIGHS IN THE LOW TO MID 80S. AS THE
COLD FRONT MOVES CLOSER TO THE FORECAST AREA SUNDAY NIGHT THERE
WILL BE A BETTER CHANCE OF THUNDERSTORMS.
ON MONDAY...THE COLD FRONT WILL BE CLOSER TO THE FORECAST AREA SO
THIS WILL BE THE MOST LIKELY PERIOD FOR THUNDERSTORMS. THE COLD
FRONT WILL WEAKEN BEFORE IT REACHES THE FORECAST AREA SO RAIN
CHANCES WILL DIMINISH ON MONDAY NIGHT.
BY TUESDAY...AN UPPER LEVEL LOW IS FORECAST TO MOVE ACROSS EASTERN
KANSAS AND INTO MISSOURI. THIS WILL PRODUCE MORE THUNDERSTORMS
ACROSS THE FORECAST AREA FOR TUESDAY AND TUESDAY NIGHT. THE UPPER
LOW WILL MOVE INTO THE OHIO VALLEY ON WEDNESDAY WITH A DECREASING
CHANCE OF THUNDERSTORMS.
THE WEATHER PATTERN BECOMES MORE SUMMER LIKE FOR THURSDAY AND NEXT
FRIDAY WITH A CHANCE OF MAINLY AFTERNOON THUNDERSTORMS WITH
TEMPERATURES CLOSE TO NORMAL LEVELS.
ARS
&&
.AVIATION...
06Z TAF CYCLE
VFR. LIGHT WINDS OVERNIGHT BECOMING SE 6-8 KTS SATURDAY.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
314 AM CDT SAT MAY 23 2015
.SHORT TERM (TODAY THROUGH SUNDAY)...
MODERATE TO HEAVY RAINFALL IS GETTING AN EARLY START WITH
CONVECTION INCREASING WEST OF HIGHWAY 83. THIS IS ALL ASSOCIATED
WITH INCREASING LIFT AHEAD OF THE MAIN UPPER LOW WHICH IS STILL
OVER UTAH/ARIZONA PER 00Z UPPER AIR ANALYSIS AND LATEST WATER
VAPOR IMAGERY. RAINFALL RATES WITH THIS ACTIVITY ARE GENERALLY AT
1-2 INCHES PER HOUR AND WE HAVE ALREADY ISSUED ONE FLOOD ADVISORY.
THE HRRR IS ZEROING IN ON THIS AREA WHERE RAIN IS CURRENTLY
INCREASING AND IS COMING UP WITH SOME HIGH TOTALS THIS MORNING.
BECAUSE OF THIS EARLY THREAT OF HEAVY RAINFALL...WILL GO AHEAD
AND START THE FLASH FLOOD WATCH NOW. THIS WILL BE A BIT TOO EARLY
FOR THE EASTERN ZONES...BUT WANT TO AVOID CONFUSION WITH A
SEGMENTED PRODUCT. HIGH-RES MODEL GUIDANCE CONTINUES TO SHOW THE
WESTERN CWA AS THE FAVORED AREA FOR CONVECTION LATER THIS MORNING
BEFORE SPREADING ACROSS THE AREA THIS AFTERNOON. RAIN LOOKS LIKELY
FOR TODAY WITH 60/70 POPS ACROSS THE CWA. INDIVIDUAL CELLS COULD
CONTAIN HEAVY RAINFALL AND SOME TRAINING OF CELLS IS ALSO
POSSIBLE.
THE MAIN FORCING WITH THIS INITIAL WAVE OF LIFT ASSOCIATED WITH
THE UPPER LOW WILL BEGIN TO ARRIVE TO THE WESTERN ZONES LATE THIS
AFTERNOON AND EVENING. CONFIDENCE IS HIGH THAT A LINE OF SHOWERS
AND THUNDERSTORMS WILL DEVELOP WITH THIS LIFT AND STRETCH ACROSS A
LARGE PORTION OF TEXAS. THERE ARE SOME DISCREPANCIES WITH THE
GUIDANCE ON THE EXACT TIMING OF THIS WITH MOST MODELS SOMEWHERE
BETWEEN THE 21Z TO 03Z TIME FRAME...WITH SOME OF THE HIGH-RES
GUIDANCE BEING THE EARLIEST. THIS LINE IS EXPECTED TO SLOWLY MARCH
THROUGH THE CWA OVERNIGHT AND IS EXPECTED TO AVERAGE A QUICK 1-3
INCHES OF RAIN AS IT MOVES ACROSS. OVERNIGHT RAIN ON TOP OF ANY
RAINFALL THAT OCCURS TODAY WILL NOT BE ABLE TO SOAK INTO THE
GROUND...AS SOILS REMAIN QUITE SATURATED FROM A VERY WET SPRING.
MOST OF THE RAIN WILL RUNOFF INTO CREEKS...STREAMS AND RIVERS AND
FLOODING IS ONCE AGAIN LIKELY.
ALTHOUGH FLOODING RAINS IS OF THE HIGHEST CONCERN ON THIS HOLIDAY
WEEKEND...THERE IS THE THREAT OF SEVERE WEATHER AS WELL. SEVERE
PARAMETERS ARE FAVORABLE FOR SEVERE STORMS...BUT AM CONCERNED WITH
THE HIGHER COVERAGE OF STORMS AND THE EFFECT THAT COULD HAVE BY
CLUTTERING UP THE NEAR-STORM ENVIRONMENT. HOWEVER...CANT RULE OUT
BOWING SEGMENTS WITHIN THE MAIN LINE THAT COULD PRODUCE SOME
SEVERE WINDS. ALSO...LOW-LEVEL WINDS WILL INCREASE AND SOME
TURNING IN THE PROFILE WILL POSE AN ISOLATED TORNADO THREAT WITH
ANY STRONGER LINE SEGMENTS AS WELL AS THE MAIN LINE MOVES THROUGH
THE AREA.
BY SUNDAY MORNING...THE LINE OF STORMS WILL BE NEARING THE EASTERN
COUNTIES AND SHOULD MOVE OUT OF THE CWA SOMETIME AROUND 18Z. THE
THREAT OF FLOODING RAINS AND SOME SEVERE WEATHER WILL CONTINUE
SUNDAY MORNING. BY SUNDAY AFTERNOON...CAPE VALUES INCREASE TO
ABOVE 3000 J/KG WHICH IS SOMEWHAT INITIALLY CONCERNING.
HOWEVER...FORECAST SOUNDINGS SHOW DECENT AMOUNTS OF DRYING ALOFT
BEHIND THE INITIAL WAVE WHICH SHOULD LIMIT ACTIVITY. ALSO...THE
ENVIRONMENT SHOULD BE PRETTY WORKED OVER FROM THE OVERNIGHT AND
MORNING ACTIVITY. THE ONE AREA TO WATCH WILL BE THE WESTERN
COUNTIES WHERE THE MOST RECOVERY TIME WILL BE AND SOME HIGH-RES
MEMBERS ARE SHOWING THE POTENTIAL FOR REDEVELOPMENT SUNDAY
AFTERNOON IN THIS GENERAL AREA.
RAINFALL AMOUNTS THIS MORNING THROUGH SUNDAY WILL AVERAGE 1-4
INCHES WITH THE HIGHER AMOUNTS NEAR THE I-35 CORRIDOR. WE MUST
CONTINUE TO STRESS TO ANYONE ON LOCAL RIVERS AND LAKES THIS
HOLIDAY WEEKEND TO PAY VERY CLOSE ATTENTION TO THE WEATHER AND ANY
WARNINGS THAT ARE ISSUED. HAVE A PLAN IN PLACE TO SEEK SHELTER
AND ALWAYS REMEMBER TO TURN AROUND...DONT DROWN.
&&
.LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
SHOULD SEE A LULL IN ACTIVITY EARLY SUNDAY NIGHT...BUT THIS
SHOULD UNFORTUNATELY BE BRIEF. CURRENTLY ON WATER VAPOR
IMAGERY...ANOTHER IMPULSE ASSOCIATED WITH THE MAIN UPPER LOW CAN
BE SEEN NEAR THE WASHINGTON AND OREGON BORDER. 00Z GUIDANCE SEEMS
TO HAVE PICKED UP ON THIS FEATURE QUITE WELL AND BRINGS IT INTO
TEXAS FOR MONDAY /MEMORIAL DAY/. SUBSEQUENTLY...THE 00Z MODEL
GUIDANCE HAS INCREASED THE QPF AMOUNTS FORECASTED FOR MONDAY
AFTERNOON. THE GFS IS THE HIGHEST OF ALL GUIDANCE WITH ANOTHER 2
INCHES OF RAIN FOR THE I-35 CORRIDOR. WENT AHEAD AND INCREASED
RAIN TOTALS IN THE OFFICIAL FORECAST...BUT NOT QUITE AS HIGH AS
THE GFS IS ADVERTISING. IF CONFIDENCE INCREASES THAT UP TO ANOTHER
2 INCHES OF RAIN WILL FALL ON MONDAY....THE FLASH FLOOD WATCH WILL
NEED TO BE EXTENDED AT A LATER TIME. CAPE/SHEAR VALUES WILL
SUPPORT THE THREAT OF SEVERE WEATHER AS WELL. FORECAST SOUNDINGS
DUE SHOW THE THREAT FOR HAIL...DAMAGING WINDS AND POSSIBLE
ISOLATED TORNADOES FOR MONDAY AFTERNOON. THE OVERALL THREAT FOR
TORNADOES WILL BE HIGHLY DEPENDENT ON THE OVERALL COVERAGE OF
ACTIVITY AND IF ANY DISCRETE SUPERCELLS ARE AVAILABLE TO DEVELOP.
AGAIN...ANYONE OUTDOORS ON THE HOLIDAY NEED TO MAKE SURE TO HAVE A
PLAN AND BE READY TO SEEK SHELTER.
THE UPPER AIR PATTERN BECOMES MORE ZONAL ON TUESDAY WITH WEAK
RIDGING ON WEDNESDAY. OVERALL COVERAGE OF ACTIVITY SHOULD DECREASE
FOR MID-WEEK. POPS WILL SLIGHTLY INCREASE ONCE AGAIN TOWARDS THE
END OF THE WORK WEEK AS THE NEXT DISTURBANCE NEARS THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 81 68 81 71 82 / 60 90 60 40 60
AUSTIN BERGSTROM INTL AIRPORT 81 68 81 70 82 / 60 90 70 40 60
NEW BRAUNFELS MUNI AIRPORT 82 68 82 71 82 / 60 90 60 40 60
BURNET MUNI AIRPORT 79 66 80 69 81 / 50 90 60 30 50
DEL RIO INTL AIRPORT 82 68 89 70 87 / 70 70 30 20 40
GEORGETOWN MUNI AIRPORT 80 68 80 70 82 / 50 90 60 40 60
HONDO MUNI AIRPORT 82 66 84 70 82 / 70 90 50 30 60
SAN MARCOS MUNI AIRPORT 81 68 80 70 82 / 60 90 60 40 60
LA GRANGE - FAYETTE REGIONAL 83 69 80 71 82 / 40 80 80 50 70
SAN ANTONIO INTL AIRPORT 82 68 82 72 83 / 60 90 60 30 60
STINSON MUNI AIRPORT 83 69 83 72 83 / 60 90 60 30 60
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SUNDAY EVENING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DE WITT...DIMMIT...EDWARDS...FAYETTE...FRIO...
GILLESPIE...GONZALES...GUADALUPE...HAYS...KARNES...KENDALL...KERR...
KINNEY...LAVACA...LEE...LLANO...MAVERICK...MEDINA...REAL...TRAVIS...
UVALDE...VAL VERDE...WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...OAKS
SYNOPTIC/GRIDS...HAMPSHIRE
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
313 AM CDT SAT MAY 23 2015
.SHORT TERM (TODAY THROUGH SUNDAY)...
MODERATE TO HEAVY RAINFALL IS GETTING AN EARLY START WITH
CONVECTION INCREASING WEST OF HIGHWAY 83. THIS IS ALL ASSOCIATED
WITH INCREASING LIFT AHEAD OF THE MAIN UPPER LOW WHICH IS STILL
OVER UTAH/ARIZONA PER 00Z UPPER AIR ANALYSIS AND LATEST WATER
VAPOR IMAGERY. RAINFALL RATES WITH THIS ACTIVITY ARE GENERALLY AT
1-2 INCHES PER HOUR AND WE HAVE ALREADY ISSUED ONE FLOOD ADVISORY.
THE HRRR IS ZEROING IN ON THIS AREA WHERE RAIN IS CURRENTLY
INCREASING AND IS COMING UP WITH SOME HIGH TOTALS THIS MORNING.
BECAUSE OF THIS EARLY THREAT OF HEAVY RAINFALL...WILL GO AHEAD
AND START THE FLASH FLOOD WATCH NOW. THIS WILL BE A BIT TOO EARLY
FOR THE EASTERN ZONES...BUT WANT TO AVOID CONFUSION WITH A
SEGMENTED PRODUCT. HIGH-RES MODEL GUIDANCE CONTINUES TO SHOW THE
WESTERN CWA AS THE FAVORED AREA FOR CONVECTION LATER THIS MORNING
BEFORE SPREADING ACROSS THE AREA THIS AFTERNOON. RAIN LOOKS LIKELY
FOR TODAY WITH 60/70 POPS ACROSS THE CWA. INDIVIDUAL CELLS COULD
CONTAIN HEAVY RAINFALL AND SOME TRAINING OF CELLS IS ALSO
POSSIBLE.
THE MAIN FORCING WITH THIS INITIAL WAVE OF LIFT ASSOCIATED WITH
THE UPPER LOW WILL BEGIN TO ARRIVE TO THE WESTERN ZONES LATE THIS
AFTERNOON AND EVENING. CONFIDENCE IS HIGH THAT A LINE OF SHOWERS
AND THUNDERSTORMS WILL DEVELOP WITH THIS LIFT AND STRETCH ACROSS A
LARGE PORTION OF TEXAS. THERE ARE SOME DISCREPANCIES WITH THE
GUIDANCE ON THE EXACT TIMING OF THIS WITH MOST MODELS SOMEWHERE
BETWEEN THE 21Z TO 03Z TIME FRAME...WITH SOME OF THE HIGH-RES
GUIDANCE BEING THE EARLIEST. THIS LINE IS EXPECTED TO SLOWLY MARCH
THROUGH THE CWA OVERNIGHT AND IS EXPECTED TO AVERAGE A QUICK 1-3
INCHES OF RAIN AS IT MOVES ACROSS. OVERNIGHT RAIN ON TOP OF ANY
RAINFALL THAT OCCURS TODAY WILL NOT BE ABLE TO SOAK INTO THE
GROUND...AS SOILS REMAIN QUITE SATURATED FROM A VERY WET SPRING.
MOST OF THE RAIN WILL RUNOFF INTO CREEKS...STREAMS AND RIVERS AND
FLOODING IS ONCE AGAIN LIKELY.
ALTHOUGH FLOODING RAINS IS OF THE HIGHEST CONCERN ON THIS HOLIDAY
WEEKEND...THERE IS THE THREAT OF SEVERE WEATHER AS WELL. SEVERE
PARAMETERS ARE FAVORABLE FOR SEVERE STORMS...BUT AM CONCERNED WITH
THE HIGHER COVERAGE OF STORMS AND THE EFFECT THAT COULD HAVE BY
CLUTTERING UP THE NEAR-STORM ENVIRONMENT. HOWEVER...CANT RULE OUT
BOWING SEGMENTS WITHIN THE MAIN LINE THAT COULD PRODUCE SOME
SEVERE WINDS. ALSO...LOW-LEVEL WINDS WILL INCREASE AND SOME
TURNING IN THE PROFILE WILL POSE AN ISOLATED TORNADO THREAT WITH
ANY STRONGER LINE SEGMENTS AS WELL AS THE MAIN LINE MOVES THROUGH
THE AREA.
BY SUNDAY MORNING...THE LINE OF STORMS WILL BE NEARING THE EASTERN
COUNTIES AND SHOULD MOVE OUT OF THE CWA SOMETIME AROUND 18Z. THE
THREAT OF FLOODING RAINS AND SOME SEVERE WEATHER WILL CONTINUE
SUNDAY MORNING. BY SUNDAY AFTERNOON...CAPE VALUES INCREASE TO
ABOVE 3000 J/KG WHICH IS SOMEWHAT INITIALLY CONCERNING.
HOWEVER...FORECAST SOUNDINGS SHOW DECENT AMOUNTS OF DRYING ALOFT
BEHIND THE INITIAL WAVE WHICH SHOULD LIMIT ACTIVITY. ALSO...THE
ENVIRONMENT SHOULD BE PRETTY WORKED OVER FROM THE OVERNIGHT AND
MORNING ACTIVITY. THE ONE AREA TO WATCH WILL BE THE WESTERN
COUNTIES WHERE THE MOST RECOVERY TIME WILL BE AND SOME HIGH-RES
MEMBERS ARE SHOWING THE POTENTIAL FOR REDEVELOPMENT SUNDAY
AFTERNOON IN THIS GENERAL AREA.
RAINFALL AMOUNTS THIS MORNING THROUGH SUNDAY WILL AVERAGE 1-4
INCHES WITH THE HIGHER AMOUNTS NEAR THE I-35 CORRIDOR. WE MUST
CONTINUE TO STRESS TO ANYONE ON LOCAL RIVERS AND LAKES THIS
HOLIDAY WEEKEND TO PAY VERY CLOSE ATTENTION TO THE WEATHER AND ANY
WARNINGS THAT ARE ISSUED. HAVE A PLAN IN PLACE TO SEEK SHELTER
AND ALWAYS REMEMBER TO TURN AROUND...DONT DROWN.
&&
.LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
SHOULD SEE A LULL IN ACTIVITY EARLY SUNDAY NIGHT...BUT THIS
SHOULD UNFORTUNATELY BE BRIEF. CURRENTLY ON WATER VAPOR
IMAGERY...ANOTHER IMPULSE ASSOCIATED WITH THE MAIN UPPER LOW CAN
BE SEEN NEAR THE WASHINGTON AND OREGON BORDER. 00Z GUIDANCE SEEMS
TO HAVE PICKED UP ON THIS FEATURE QUITE WELL AND BRINGS IT INTO
TEXAS FOR MONDAY /MEMORIAL DAY/. SUBSEQUENTLY...THE 00Z MODEL
GUIDANCE HAS INCREASED THE QPF AMOUNTS FORECASTED FOR MONDAY
AFTERNOON. THE GFS IS THE HIGHEST OF ALL GUIDANCE WITH ANOTHER 2
INCHES OF RAIN FOR THE I-35 CORRIDOR. WENT AHEAD AND INCREASED
RAIN TOTALS IN THE OFFICIAL FORECAST...BUT NOT QUITE AS HIGH AS
THE GFS IS ADVERTISING. IF CONFIDENCE INCREASES THAT UP TO ANOTHER
2 INCHES OF RAIN WILL FALL ON MONDAY....THE FLASH FLOOD WATCH WILL
NEED TO BE EXTENDED AT A LATER TIME. CAPE/SHEAR VALUES WILL
SUPPORT THE THREAT OF SEVERE WEATHER AS WELL. FORECAST SOUNDINGS
DUE SHOW THE THREAT FOR HAIL...DAMAGING WINDS AND POSSIBLE
ISOLATED TORNADOES FOR MONDAY AFTERNOON. THE OVERALL THREAT FOR
TORNADOES WILL BE HIGHLY DEPENDENT ON THE OVERALL COVERAGE OF
ACTIVITY AND IF ANY DISCRETE SUPERCELLS ARE AVAILABLE TO DEVELOP.
AGAIN...ANYONE OUTDOORS ON THE HOLIDAY NEED TO MAKE SURE TO HAVE A
PLAN AND BE READY TO SEEK SHELTER.
THE UPPER AIR PATTERN BECOMES MORE ZONAL ON TUESDAY WITH WEAK
RIDGING ON WEDNESDAY. OVERALL COVERAGE OF ACTIVITY SHOULD DECREASE
FOR MID-WEEK. POPS WILL SLIGHTLY INCREASE ONCE AGAIN TOWARDS THE
END OF THE WORK WEEK AS THE NEXT DISTURBANCE NEARS THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 81 68 81 71 82 / 60 90 60 40 60
AUSTIN BERGSTROM INTL AIRPORT 81 68 81 70 82 / 60 90 70 40 60
NEW BRAUNFELS MUNI AIRPORT 82 68 82 71 82 / 60 90 60 40 60
BURNET MUNI AIRPORT 79 66 80 69 81 / 50 90 60 30 50
DEL RIO INTL AIRPORT 82 68 89 70 87 / 70 70 30 20 40
GEORGETOWN MUNI AIRPORT 80 68 80 70 82 / 50 90 60 40 60
HONDO MUNI AIRPORT 82 66 84 70 82 / 70 90 50 30 60
SAN MARCOS MUNI AIRPORT 81 68 80 70 82 / 60 90 60 40 60
LA GRANGE - FAYETTE REGIONAL 83 69 80 71 82 / 40 80 80 50 70
SAN ANTONIO INTL AIRPORT 82 68 82 72 83 / 60 90 60 30 60
STINSON MUNI AIRPORT 83 69 83 72 83 / 60 90 60 30 60
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 1 PM CDT THIS AFTERNOON THROUGH SUNDAY
EVENING FOR THE FOLLOWING COUNTIES: ATASCOSA...BANDERA...BASTROP...
BEXAR...BLANCO...BURNET...CALDWELL...COMAL...DE WITT...DIMMIT...
EDWARDS...FAYETTE...FRIO...GILLESPIE...GONZALES...GUADALUPE...
HAYS...KARNES...KENDALL...KERR...KINNEY...LAVACA...LEE...LLANO...
MAVERICK...MEDINA...REAL...TRAVIS...UVALDE...VAL VERDE...
WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...OAKS
SYNOPTIC/GRIDS...HAMPSHIRE
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
349 AM PDT Sat May 23 2015
.Synopsis...
Warmer temperatures with showers and thunderstorms expected this
weekend into next week, especially over mountains.
&&
.Discussion (Today through Tuesday)...
Broad upper low over desert SW this morning with a fairly
significant wave over the Pac NW moving southward. Leading edge
instability has triggered some showers over the west slopes of
Sierra northward of Hwy 20/I-80. The HRRR picked up on this area
of precipitation pretty well. The HRRR continues the
shower/thunderstorm development over the west slopes this
morning into the afternoon. The model also develops activity over
the Coastal Range from Glenn county down into western Yolo county
late this morning and afternoon.
In the meantime, marine stratus has developed over the Sacramento
region again this morning. As long as these troughs impact the
west coast, we keep the tightened onshore surface pressure
gradient and the threat of the stratus intrusion. Monday looks
like the next chance for some valley stratus.
The mountains will continue to see showery activity through
Tuesday, although activity may not be quite as widespread as
today. Seasonably cool temperatures will continue today with a
slow and gradual warming trend expected into early next week.
JClapp
&&
.Extended Discussion (Wednesday through Saturday)
Upper ridge forecast to return during the second half of next
week as the trough finally shifts east into the Rockies. This will
result in temperatures returning to around normal for late May
along with a reduction in mountain showers and thunderstorms.
Another trough may approach the west coast next weekend.
&&
.Aviation...
General VFR conditions expected next 24 hours except areas of
MVFR with local IFR conditions over the mountains in the vicinity
showers and isolated thunderstorms. Areas of MVFR ceilings in the
Sacramento area until about 16Z-17Z. Local southwesterly wind
gusts 10-20 kts.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS RENO NV
326 AM PDT SAT MAY 23 2015
.SYNOPSIS...
SCATTERED TO NUMEROUS SHOWERS AND A FEW THUNDERSTORMS ARE
EXPECTED TODAY FOR EASTERN CALIFORNIA AND WESTERN NEVADA AS LOW
PRESSURE MOVES OVER THE REGION. SHOWERS AND THUNDERSTORMS WILL
DECREASE IN COVERAGE SUNDAY AND MONDAY. TEMPERATURES BELOW AVERAGE
TODAY WILL WARM TO AROUND AVERAGE FOR SUNDAY AND MEMORIAL DAY
MONDAY.
&&
.SHORT TERM...
RAISED POP TODAY, ESPECIALLY FOR LATE MORNING AND THIS AFTERNOON FOR
THE EASTERN SIERRA AND FOR PORTIONS OF FAR WESTERN NEVADA. I ALSO
REDUCED OR REMOVED LATE NIGHT/MORNING SHOWER COVERAGE SUNDAY AND
MONDAY NIGHTS.
A FEW LIGHT SHOWERS AND AREAS OF DRIZZLE ARE ONGOING EARLY THIS
MORNING WITH HIGH HUMIDITIES AND WIDESPREAD STRATUS OR STRATOCUMULUS
DECKS PER SATELLITE AND OBSERVATIONS. THE NEXT WEATHER MAKER CAN
BE SEEN IN THE WATER VAPOR SATELLITE AS A CIRCULATION DROPPING
SOUTH ALONG THE OREGON COAST. THIS LOW WILL DROP INTO NORTHERN
CALIFORNIA THIS AFTERNOON AND EARLY EVENING. WITH THE MOIST AIRMASS,
SHOWERS ARE ALREADY BREAKING OUT IN THE SIERRA FOOTHILLS EAST OF
CHICO AND REDDING. THE 08Z HRRR INDICATES SHOWERS PUSHING OVER THE
CREST BETWEEN SUSANVILLE AND LAKE TAHOE BY MID MORNING. THIS
MAKES SENSE GIVEN THE SHOWERS ALREADY DEVELOPING AND THE INCOMING
UPPER LOW.
THIS AFTERNOON, WIDESPREAD SHOWERS ARE PROGGED TO PUSH OUT INTO
NEVADA AS THE UPPER LOW DROPS THROUGH THE SACRAMENTO VALLEY. WITH
THIS IN MIND, I HAVE RAISED POP TO LIKELY FOR THE RENO-TAHOE AREA
WITH A GOOD CHANCE FOR MANY OTHER AREAS NEAR AND SOUTH OF I-80.
THIS EVENING, THE GFS AND NAM SHOW THE BEST CHANCE FOR PRECIPITATION
SLIDING TO SOUTH OF HIGHWAY 50 AS A DEFORMATION AXIS TO THE EAST
OF THE LOW MOVES OVER THAT AREA. AS FAR AS THUNDERSTORMS THIS
AFTERNOON AND EVENING, THE CHANCES REMAIN LOW WITH THE CLOUDY,
MOIST CONDITIONS LIMITING CAPE. HOWEVER, A FEW THUNDERSTORMS ARE
EXPECTED IN THE MOIST AND AT LEAST SLIGHTLY UNSTABLE ATMOSPHERE.
TONIGHT, AND ESPECIALLY SUNDAY NIGHT, THERE WILL BE AN INCREASED
CHANCE FOR FOG AS CLOUD COVER DECREASES BEHIND TODAY`S LOW AND
MOISTURE REMAINS HIGH. HOWEVER, IT IS STILL QUITE UNCERTAIN AND WILL
DEPEND ON WHETHER THE LOWER LEVEL STRATUS DECK CAN BREAK UP. FOR
NOW, I JUST THREW IN PATCHY FOG AS A HEADS UP.
SUNDAY, THE COVERAGE OF SHOWERS LOOKS TO DECREASE SUBSTANTIALLY AS
SOME WARMING ALOFT/SLIGHT RIDGING MOVES IN BEHIND TODAY`S UPPER
LOW. HOWEVER, MORE INSOLATION AND RESIDUAL LOW LEVEL MOISTURE MAY
STILL ALLOW FOR A FEW AFTERNOON THUNDERSTORMS (MAINLY NEAR THE
SIERRA). ON MONDAY, A GLANCING BLOW FROM AN UPPER DISTURBANCE
MOVING THROUGH THE PACIFIC NORTHWEST WILL BRING INCREASED
AFTERNOON WESTERLY WINDS TO THE REGION. ELEVATED MOISTURE REMAINS
IN THE AREA SO CONVERGENCE AT THE LEADING EDGE OF THE WEST FLOW
ALONG WITH WARMER TEMPERATURES COULD BRING ISOLATED TO SCATTERED
AFTERNOON SHOWERS AND THUNDERSTORMS. SNYDER
.LONG TERM...TUESDAY THROUGH FRIDAY...
LOW PRESSURE IN THE PACIFIC NORTHWEST WILL SLOWLY MOVE EAST
TUESDAY AND WEDNESDAY. LIGHT WEST FLOW ALOFT WILL CONTINUE, BUT
PLENTY OF RESIDUAL MOISTURE WILL REMAIN FOR A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS. TEMPERATURES WILL ALSO WARM TO NEAR
AVERAGE FOR LATE MAY.
FOR THURSDAY INTO FRIDAY, RIDGING WILL BUILD ALONG THE WEST COAST IN
THE WAKE OF THE LOW. TEMPERATURES WILL CONTINUE TO WARM WITH 80S
LIKELY IN WESTERN NV AND 70S IN THE SIERRA VALLEYS. IN ADDITION,
WARMING TEMPS ALOFT WITH THE RIDGE AND SLOW SURFACE DRYING SHOULD
RESULT IN DRY CONDITIONS BY FRIDAY. CONTINUED A THREAT OF ISOLATED
SHOWERS AND THUNDERSTORMS THURSDAY IN THE WAKE OF THE LOW, ALTHOUGH
KEPT THEM OUT OF THE TAHOE BASIN WITH LIGHT WEST WINDS AND
INCREASING STABILIZATION. WALLMANN
&&
.AVIATION...
SHOWERS CONTINUE THIS MORNING ACROSS MUCH OF NORTHEAST CALIFORNIA
AND NORTHWEST NEVADA. LCL MVFR CONDS CONTINUE IN -SHRA WITH CIGS
2-3000 FEET, BUT MOST 4-5000 FEET. EXPECT AND INCREASE IN SHOWERS
WITH ISOLD TSRA 15-21Z WITH AN INCOMING IMPULSE. GREATEST IMPACT
WILL BE AROUND RENO-TAHOE AREAS WITH MVFR CIGS TO 2-3000 FEET,
ALTHOUGH KMMH WILL ALSO BE THREATENED LATER. GS ALSO POSSIBLE IN
ANY TSRA.
AFTER 00Z, BEHIND THE IMPULSE, MORE STABILIZATION WILL OCCUR WITH
POSSIBLE CLEARING. AT THIS POINT, CONFIDENCE IS LOW ON HOW MUCH
CLEARING WILL OCCUR WITH ONLY ISOLD -SHRA POSSIBLE AFTER 03Z. IF
SKIES CLEAR ENOUGH, EXPECT FG TO FORM IN MANY VALLEYS FROM THE
RECENT RAIN. KTRK/MARTIS VALLEY MOST LIKELY TO BE AFFECTED, BUT
KRNO/KLOL/KTVL MAY ALSO SEE FG WITH VIS NEAR OR BLO 1/4SM.
POTENTIAL FG FOR KTRK 60 PCT WITH OTHER AREAS 20-30 PCT. WALLMANN
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS MIAMI FL
923 AM EDT SAT MAY 23 2015
.UPDATE...
SURFACE ANALYSIS FROM THIS MORNING SHOWED A LEFTOVER BOUNDARY
ALONG THE EAST COAST OF FLORIDA THIS MORNING EAST NORTHEAST OF
LAKE OKEECHOBEE. SHOWERS AND STORMS MAY FOCUS NEAR THIS BOUNDARY
LATE THIS MORNING INTO THE EARLY AFTERNOON AND THEN MOVE TO THE
WEST AND SOUTHWEST TOWARDS THE INTERIOR AND GULF COAST. THE 12Z
SOUNDING SHOWED DRIER LOW LEVEL AIR AND WARMER TEMPERATURES ALOFT
COMPARED TO YESTERDAY. SO THE LOWER INSTABILITY WILL LEAD TO A
LOWER THREAT OF STRONG STORMS COMPARED TO THE PAST COUPLE DAYS.
HOWEVER...AN ISOLATED STRONG STORM OR TWO CANNOT BE RULED OUT
ACROSS THE GULF COAST THIS AFTERNOON...WITH THE MAIN THREATS BEING
FREQUENT LIGHTNING...GUSTY WINDS UP TO 50 MPH...SMALL HAIL...AND
HEAVY RAIN.
THE FLOW HAS BECOME EAST TO NORTHEAST IN THE LOW/MID LEVELS DUE
TO HIGH PRESSURE BUILDING OVER THE MID ATLANTIC AND SOUTHEAST
STATES. THIS FLOW WILL STRENGTHEN THROUGHOUT THE DAY AND OVER THE
MEMORIAL DAY WEEKEND...WITH LIFE THREATENING RIP CURRENTS LIKELY
AT THE EAST COAST BEACHES BY THIS EVENING AND CONTINUING THROUGH
TUESDAY. ISOLATED/SCATTERED SHOWERS AND A FEW EMBEDDED STORMS HAVE
DEVELOPED OVER THE ATLANTIC WATERS AND WERE MOVING TOWARDS THE
EAST COAST METRO AREAS. A WATERSPOUT WAS ALSO REPORTED ABOUT 16
MILES EAST OF MIAMI BEACH THIS MORNING. WATERSPOUTS WILL REMAIN
POSSIBLE...ESPECIALLY THIS MORNING...OVER THE ATLANTIC WATERS.
BUMPED UP POPS FOR THE EAST COAST AND ADDED SLIGHT CHANCE OF
STORMS. ISOLATED/SCATTERED SHOWERS AND A FEW STORMS ARE POSSIBLE
FOR THE EAST COAST METRO AREAS...MAINLY THROUGH EARLY AFTERNOON.
STORMS WILL THEN FOCUS ACROSS THE GULF COAST THIS AFTERNOON AS THE
EAST COAST SEA BREEZE PUSHES INLAND AND A WEAK GULF COAST SEA
BREEZE DEVELOPS. THE HRRR AND LOCAL WRF MODELS SHOW THE LAKE
SHADOW ON THE WEST AND SOUTHWEST SIDES OF THE LAKE MAY INHIBIT
DEVELOPMENT...SO LOWERED POPS THERE.
&&
.PREV DISCUSSION... /ISSUED 738 AM EDT SAT MAY 23 2015/
AVIATION...
LIGHT WINDS EARLY THIS MORNING WILL BECOME NE/E BY 14Z AS HIGH
PRESSURE BEGINS TO ESTABLISH ITSELF ACROSS FLORIDA. VFR CONDITIONS
WILL PREVAIL DESPITE HAZY/SMOKY SKIES EARLY THIS MORNING. NARROW
AREA OF SHOWERS AND POSSIBLY A TSTM MAY AFFECT FLL/PBI AREAS THIS
MORNING THROUGH ABOUT 18Z WITH VCSH INCLUDED AT THESE TERMINALS.
EASTERLY FLOW WILL SHIFT SHOWERS/TSTMS TO THE WESTERN HALF OF THE
PENINSULA AFTER 18Z WITH TEMPO TSRA AND MVFR AT KAPF. MOST OF THE
SHOWERS/TSTMS SHOULD WIND DOWN BY OR SHORTLY AFTER 00Z WITH MOSTLY
VFR CONDITIONS TONIGHT. /MOLLEDA
PREV DISCUSSION... /ISSUED 342 AM EDT SAT MAY 23 2015/
DISCUSSION...
WEAK SURFACE TROUGH, THIS VERY EARLY MORNING, LEFT OVER FROM WEAK
LOW PRESSURE/STATIONARY FRONT OVER CENTRAL FL YESTERDAY, WILL KICK
OFF A FEW SHOWERS/STORMS OFFSHORE AND NEAR THE BEACHES OF PALM
BEACH/BROWARD/MIAMI-DADE COUNTIES. AS STRONG SURFACE HIGH
PRESSURE MOVES OFF THE EAST COAST TODAY, THE PRESSURE GRADIENT
INCREASES INTO SUNDAY AND THE RESULTING DEEP EASTERLIES LEAD TO A
HIGH RISK OF RIP CURRENTS FOR THE HOLIDAY WEEKEND. A POCKET OF
DRIER AIR ALOFT COMPARED TO YESTERDAY, WILL BE FORCED INTO THE
EAST COAST ON VEERING H85 AND H7 WIND FLOW LATER TODAY. PWATS MAY
DROP OFF SLIGHTLY BY THIS EVENING. NE TO E WINDS WILL COMBINE WITH
A LATE DAY GULF BREEZE TO PLACE MOST SHOWERS/STORMS ACROSS THE
WEST COAST AND INTERIOR SECTIONS. ALTHOUGH H5 TEMPS WARM SLIGHTLY
AND H7-H5 LAPSE RATES DECREASE A LITTLE COMPARED TO YESTERDAY,
CAN`T RULE OUT A FEW STRONGER STORMS WEST COAST TODAY.
SHOWERS MAY FORM ALONG THE EAST COAST TONIGHT AND DURING PART OF
SUNDAY MORNING AS THE EASTERLIES REALLY GET UNDERWAY. DOWNRIGHT
BREEZY INTO SUN AFTERNOON WITH SOME 25KT GUSTS ALONG THE EAST
COAST POSSIBLE. SOME OF THE MORNING COASTAL SHOWERS MAY PENETRATE
INLAND. MONDAY LOOKS SIMILAR, BUT AGAIN MOST STORMS WILL BE
INTERIOR AND WEST COAST.
WITH THE COLD H5 TROUGH LIFTING FROM THE NORTHEAST SUNDAY, AND A
DEEP WEST COAST/FOUR CORNERS TROUGH PERSISTING, A MID LEVEL RIDGE
WILL HAVE FREE REIGN TO GROW AND EXPAND NOT ONLY OVER FLORIDA, BUT
EVENTUALLY OVER THE SOUTHEAST CONUS COAST. WITH THE RIDGE CUTTING
OFF THROUGH H3, LARGE SUBSIDENCE WILL LEAD TO A SIGNIFICANT AMOUNT
OF DRIER MID-LEVEL AIR ACROSS THE EAST COAST AND FLORIDA BY THE
MIDDLE OF NEXT WEEK. MODEL SOUNDINGS ACTUALLY DROP PWATS CLOSE TO 1"
AT TIMES ALONG THE EAST COAST. ALTHOUGH THERE WILL REMAIN
OPPORTUNITIES FOR STORMS ON THE WEST COAST, POPS WILL BE RATHER LOW
BY MIDWEEK REGION-WIDE.
AS THE H5 RIDGE AND SURFACE HIGH EVENTUALLY MOVE NORTHEAST AND
AWAY FROM THE EASTERN SEABOARD, THE GRADIENT WILL RELAX AND
PERSISTENT MODERATE EASTERLIES WILL BEGIN TO WEAKEN A BIT INTO
LATE WEEK.
MARINE...
THE GRADIENT INCREASES AS SURFACE HIGH PRESSURE MOVES OFF THE
EASTERN SEABOARD TODAY. WINDS BECOME INCREASINGLY EASTERLY AND
STRONGER THROUGH THE WEEKEND, CLOSE TO 15KTS BY LATE TODAY, THEN
NEAR 20KTS SUSTAINED LATE SUNDAY AND MONDAY, ELSE 15-20 KTS THROUGH
THE REST OF THE FORECAST. MID AND UPPER LEVEL HIGH PRESSURE WILL
REMAIN ANCHORED ALONG THE EAST COAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 78 87 79 / 30 30 30 20
FORT LAUDERDALE 88 78 87 79 / 30 30 30 30
MIAMI 89 77 88 78 / 30 20 30 30
NAPLES 93 73 93 72 / 70 30 60 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK FROM 8 PM EDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR FLZ168-172-173.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...84/AK
LONG TERM....21/KM
AREA FORECAST DISCUSSION...UPDATED
NWS TAMPA BAY RUSKIN FL
918 AM EDT SAT MAY 23 2015
.UPDATE...
12Z TBW RAOB SHOWS AN EASTERLY WIND FLOW IN PLACE ACROSS THE AREA WITH
WINDS APPROACHING 20 KTS IN THE LOWEST 1KFT OF THE MORNING SOUNDING.
A PWAT VALUE NEAR 1.6 INCHES SHOWS MORE THAN ENOUGH MOISTURE AVAILABLE
IN THE ATMOSPHERE TODAY TO SPARK ANOTHER ROUND OF AFTN SHOWERS AND
TSTMS. GIVEN THE STRONG EASTERLY FLOW IN PLACE...IT WILL BE DIFFICULT
FOR WEST COAST SEABREEZE TO PENETRATE TOO FAR INLAND TODAY SO HIGHEST
RAIN CHANCES LOOK TO BE CLOSER TO THE GULF COAST TODAY...ESPECIALLY
FROM AROUND TAMPA BAY INTO SW FLORIDA. RECENT RUNS OF CONVECTION
ALLOW MODELS AND THE HRRR SUPPORT THIS FORECAST THINKING. AS FAR
AS TEMPERATURES ARE CONCERNED...IT WILL BE HOT ONCE AGAIN WITH
TEMPS RUNNING A FEW DEGREES ABOVE NORMAL TO START THIS HOLIDAY
WEEKEND. THE CURRENT FORECAST LOOKS ON TRACK SO ONLY A FEW MINOR
ADJUSTMENTS WERE MADE FOR THE MORNING UPDATE.
&&
.AVIATION...
BRIEF MVFR/IFR CEILINGS AND VISIBILITIES WILL BE POSSIBLE AFTER 20Z
AS SHRA/TSRA DEVELOP AND MOVE ACROSS THE REGION...OTHERWISE VFR WILL
PREVAIL. EAST SOUTHEAST WINDS AROUND 10 KNOTS EXPECTED AFTER ABOUT
15Z THEN BRIEFLY BECOMING WEST TO NORTHWEST AT THE COASTAL TAF
SITES AFTER 20Z AS THE SEA BREEZE DEVELOPS...WITH GUSTS UP TO 30
KNOTS POSSIBLE IN THE VICINITY OF TSRA.
&&
.MARINE...
SURFACE HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY THROUGH THE
HOLIDAY WEEKEND AND INTO EARLY NEXT WEEK. AS THE HIGH BUILDS IN AN
INCREASING EAST TO SOUTHEAST WIND FLOW IS EXPECTED ACROSS THE GULF
WATERS WITH PERIODS OF CAUTIONARY OR LOW END SMALL CRAFT CONDITIONS
POSSIBLE THROUGH THE PERIOD...MAINLY DURING THE LATE NIGHT AND EARLY
MORNING HOURS. NO CHANGES NEEDED FOR THE MORNING UPDATE.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 92 74 91 74 / 60 10 60 20
FMY 92 73 91 73 / 60 20 50 20
GIF 92 72 91 72 / 50 10 40 10
SRQ 92 73 90 74 / 60 20 60 20
BKV 92 71 90 70 / 40 10 60 20
SPG 91 76 90 76 / 60 20 60 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION/FIRE WEATHER/MARINE...11/MCKAUGHAN
DECISION SUPPORT...13/OGLESBY
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
642 AM CDT SAT MAY 23 2015
.UPDATE...
ISSUED AT 636 AM CDT SAT MAY 23 2015
RADAR IMAGERY DEPICTS LIGHT RETURNS ACROSS NORTHERN MO THIS AM.
THESE ECHOES ARE SLOWLY MOVING TO THE ENE. AT THIS TIME DO NOT SEE
ANY OF IT MAKING IT TO THE GROUND. HRRR DEPICTS ISOLATED LIGHT
SHOWERS ACROSS THE AREA TODAY. WITH THE EXCEPTION OF THE SOUTHERN
CWA...TEMP DEWPOINT SPREADS REMAIN LARGE INDICATING THAT MORE
SATURATION WOULD NEED TO OCCUR FOR THE RAIN TO REACH THE GROUND.
DID NOT BUMP UP POPS AS I MY GUT TELLS ME WE WONT SEE MUCH FROM
THESE SHOWERS. WOULDNT BE SURPRISED TO GET SPRINKLES FROM THOUGH
DURING THE DAY TODAY. WILL ADVISE DAY SHIFT TO KEEP AN EYE ON
THESE SHOWERS IN CASE IT STARTS REACHING THE GROUND.
&&
.SYNOPSIS...
ISSUED AT 255 AM CDT SAT MAY 23 2015
HIGH PRESSURE WAS ENTRENCHED ACROSS THE AREA THIS MORNING. THE
STRONGEST HIGH WAS LOCATED OFF TO OUR EAST. THIS WAS LEADING TO A
LIGHT EASTERLY WIND ACROSS OUR EASTERN AREA. HIGH LEVEL MOISTURE
LEAD TO CIRRUS CLOUDS ACROSS THE AREA. THIS MOISTURE WAS THE
RESULT OF A SOUTH SOUTHWEST FLOW AT THE UPPER LEVELS. THIS FLOW
AND RIPPLES THROUGH THE FLOW WILL BE THE DOMINATE WEATHER PRODUCER
THROUGH THE HOLIDAY WEEKEND.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 255 AM CDT SAT MAY 23 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM ARE THE CHANCES FOR
PRECIPITATION TONIGHT. THE PRECIPITATION GRADIENT WILL BE LOCATED
SOMEWHERE ACROSS THE CWA...MAKING FOR A DIFFICULT FORECAST.
DURING THE DAY TODAY...HIGH LEVEL CLOUDS SHOULD PERSIST. WAA INTO
THE AREA AND INSOLATION WILL HELP TO INCREASE TEMPERATURES ACROSS
THE AREA TODAY INTO THE MID AND UPPER 70S. A FEW SITES MAY EVEN
BREAK THE 80 DEGREE MARK. H5 RIDGING WILL MOVE THROUGH THE AREA
TODAY AND EVEN THROUGH THE OVERNIGHT HOURS. THE FLOW WILL THEN
TURN SOUTH TO SOUTHWEST. THIS WILL LEAD TO MOISTURE ADVECTION
INTO THE AREA. TODAY WILL BE THE LAST DAY OF THE WEEKEND WITH NO
POPS.
TONIGHT...H5 RIDGING SHOULD OCCUPY MOST OF THE CWA THROUGH 12Z.
THIS...SHOULD HELP TO LIMIT OVERALL POPS FOR THE NIGHT. SPECTRAL
MODELS SUGGEST THAT WE WILL SEE PRECIP OVER MOST OF THE AREA FROM
6Z TO 12Z SUNDAY AM. THE NAM SUGGESTS THAT MOST OF THE PRECIP WILL
BE WEST OF THE MISSISSIPPI RIVER. MODEL REFLECTIVITY FROM THE
WRFARW AND WRFNMM SUPPORTS THIS NOTION AS WELL. AS FAR AS I CAN
TELL...THE NAM AND AND WRF MODELS HAVE A BETTER HANDLE ON COVERAGE
ACROSS THE CWA. THIS MEANS THAT RAIN WILL LIKELY STAY WEST OF
MISSISSIPPI RIVER THROUGH 12Z SUNDAY. A LACK OF INSTABILITY
SUGGESTS THAT THIS WILL BE MOSTLY RAIN. I CANNOT RULE OUT AN
ISOLATED THUNDERSTORM WITH THIS FLOW. I PUT THUNDER IN THE
FORECAST FOR ANY AREA THAT HAS A CHANCE OR GREATER FOR PRECIP.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 255 AM CDT SAT MAY 23 2015
NEAR TO SLIGHTLY ABOVE NORMAL TEMPS AND UNSETTLED WITH PERIODIC BOUTS OF SHOWERS
AND SOME STORMS.
SUNDAY AND SUNDAY NIGHT...HIGHER POPS TARGETING MAINLY WESTERN 1/2-2/3 OF CWA
ESPECIALLY SUNDAY AM WITH VEERING LOW LEVEL JET AND ATTENDANT MOIST ADVECTION AND
CONVERGENCE. THEN...CONTINUED CHANCES SUNDAY AFTERNOON WITH MOIST AXIS (PWATS
1.5-1.75 INCHES) AND POTENTIAL PERTURBATIONS EMBEDDED IN SOUTHWEST FLOW ALOFT.
PERHAPS SECONDARY FOCUS OF HIGHER POPS ARRIVING SUNDAY NIGHT WITH SHORTWAVE TROUGH
LIFTING INTO THE UPPER MIDWEST.
MEMORIAL DAY AND MONDAY NIGHT... MORE AGREEMENT THAT MEMORIAL DAY HARBORS A MUCH
LOWER POTENTIAL FOR PCPN AS FLOW VEERS WESTERLY USHERING IN SLIGHT DRYING AND
SHIFTING MAIN MOIST AXIS TO OUR EAST... WHILE MAIN FORCING ATTENDANT TO SHORTWAVE
TROUGH LIFTING AWAY FROM REGION. THUS MEMORIAL DAY OVERALL SHOULD HAVE MANY DRY
HOURS... BUT WARM AND MUGGY CONDITIONS WITH HIGHS AROUND 80 OR LOWER 80S AND DEWPTS
WELL IN THE 60S. PCPN CHCS LOOK TO INCREASE AGAIN MONDAY NIGHT AS SECONDARY
DISTURBANCE MOVES THROUGH THE MID-MISSISSIPPI VALLEY... AND ATTENDANT WEAK SURFACE
COOL FRONT SAGS INTO THE REGION BY TUESDAY AM.
TUESDAY THROUGH FRIDAY... SOME INDICATIONS OF POSSIBLY ANOTHER DRIER PERIOD DEVELOPING
BY WEDNESDAY OR WEDNESDAY NIGHT WITH PASSAGE OF WEAK FRONT AND INCREASING HEIGHTS
ALOFT IN WAKE OF UPPER LEVEL SHORTWAVE. PATTERN THOUGH LOOKS TO RELOAD AND TURN ACTIVE
YET AGAIN LATTER HALF OF THE WEEK AND JUST BEYOND WITH GULF MOISTURE INCREASING AHEAD
OF ANOTHER PLAINS TROUGH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 636 AM CDT SAT MAY 23 2015
VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD. EXPECT CLOUD DECK
TO START LOWERING BUT STAY AOA 5KFT. RAIN WILL START TO MOVE INTO
THE AREA NEAR THE END OF THE TAF PERIOD. WITH LOW CONFIDENCE ON
OVERALL COVERAGE OF THE PRECIP DECIDED TO LEAVE MENTION OF POPS
OUT. AT THIS TIME IT APPEARS CID IS THE ONLY SITE THAT COULD HAVE
-RA BEFORE 12Z SUNDAY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...GIBBS
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...05
AVIATION...GIBBS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
928 AM MDT SAT MAY 23 2015
.UPDATE...
A WEAK UPPER LOW OVER WESTERN MONTANA WITH A SECOND LOW OVER
EASTERN UTAH WILL BRING A CHANCE FOR SHOWERS AND ISOLATED
THUNDERSTORMS TO THE FORECAST AREA TODAY. RADAR SHOWING A FEW
SHOWERS ACROSS OUR WEST AND FAR EASTERN AREAS WITH MOVEMENT
BASICALLY EAST TO WEST DUE TO THE UPPER LOWS CIRCULATION.
SATELLITE IS SHOWING A NARROW BREAK IN THE CLOUDS ACROSS
ROSEBUD...TREASURE...NORTHERN BIG HORN AND EASTERN YELLOWSTONE
COUNTIES THIS MORNING. THIS WILL RESULT IN PARTLY SUNNY SKIES THIS
MORNING FOR THESE AREAS BUT CLOUDS ACROSS NORTHERN WYOMING AND
SOUTHEAST MONTANA WILL BEGIN TO MOVE INTO THE AREA BY AFTERNOON.
THE HRRR MODEL SHOWS SHOWER ACTIVITY MAINLY STAYING WEST OF
BILLINGS THROUGH MOST OF THE DAY WITH ACTIVITY POPPING UP BY MID
AFTERNOON ACROSS THE EAST. BRIEF HEAVY RAIN AND POSSIBLY SMALL
HAIL DUE TO LOW FREEZING LEVELS WILL BE POSSIBLE WITH ANY
SHOWER/THUNDERSTORM. HOWEVER...NO SEVERE WEATHER IS EXPECTED
TODAY.
UPDATE THIS MORNING WAS TO LESSEN PRECIP CHANCES ACROSS THE FAR
EAST AND TO CLEAR OUT SKIES SOME FOR THE EAST AND CENTRAL AREAS.
UPDATED FORECAST HAS BEEN SENT. HOOLEY
&&
.SHORT TERM...VALID FOR TDY AND SUN...
BROAD TROUGHING WILL BE OVER THE FORECAST AREA THROUGH THE
WEEKEND. THIS PATTERN WILL LEND TO UNSETTLED WEATHER IN THE FORM
OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS.
AN UPPER LOW WITHIN THE BROAD TROUGH WAS SITTING OVER SOUTHEAST
UTAH THIS MORNING. THIS LOW WILL SLOWLY SLIDE TOWARD SOUTHEAST
COLORADO BY TONIGHT. WEAKER ENERGY WILL ADVECT INTO THE FORECAST
AREA FROM WYOMING AS IT GETS EJECTED OFF OF THE MAIN LOW. THIS
COMBINED WITH WEAK DIFFLUENT FLOW AND PERSISTENT LOW LEVEL UPSLOPE
WITH BE ENOUGH TO GENERATE SCATTERED SHOWERS. INSTABILITY WAS NOT
GREAT BUT ENOUGH FOR A FEW LIGHTNING STRIKES...SIMILAR TO FRIDAY.
RELATIVELY LOW FREEZING LEVELS WILL LEAD TO THE POSSIBILITY OF
SMALL HAIL. WEAK STEERING WINDS WOULD ALSO LEAD TO SLOW MOVING
CELLS AND THUS LOCALLY HEAVY RAIN. STORMS WILL BE PULSY IN NATURE
AND THUS SHOULD NOT BE TERRIBLY STRONG.
THE UPPER LOW TO THE SOUTH WILL CREEP INTO WESTERN SOUTH DAKOTA
SUNDAY AFTERNOON. MODELS ALL HAVE BEEN ADVERTISING AN INCREASE IN
PRECIPITABLE WATER AMOUNTS AS PWATS RISE TO AROUND AN INCH OVER
SOUTHEAST MONTANA. THE GFS WAS DEEPER WITH THE NORTHERN EXTENT OF
THE MAIN UPPER LOW...AND FARTHER WEST IN PLACEMENT. THUS...THE GFS
WAS HEAVIER IN QPF TOTALS COMPARED TO THE ECMWF. HIGH PWATS OVER
THE EAST WOULD LEAD TO THE POSSIBILITY OF HEAVY RAIN. THE AXIS OF
HEAVY RAIN LOOKS TO BE EAST OF A FORSYTH TO SHERIDAN LINE.
HIGH TEMPERATURES TODAY WILL BE COOLER COMPARED TO FRIDAY WITH
ADDED CLOUD COVER. A SURFACE LOW FORMING OVER WESTERN NEBRASKA
WILL PULL IN EVEN COOLER AIR FOR SUNDAY. TWH
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
MODELS CONTINUE TO PAINT A GENERALLY UNSETTLED PATTERN FOR THE
EXTENDED. MONDAY WILL SEE SOME WEAK RIDGING WORKING INTO THE
AREA...SLOWLY DISPLACING THE WEEKEND LOW PRESSURE SYSTEM. SOME
INSTABILITY WILL WRAP AROUND THE BACKSIDE OF THE LOW...WHICH
WILL GIVE THE EASTERN HALF OF THE AREA A CHANCE OF RAIN...WITH
BETTER CHANCES CLOSER TO SOUTH DAKOTA. THE AREA WILL CONTINUE TO
BE IN A WEAKLY RIDGY PATTERN TUESDAY...BUT AS THE THE PATTERN
BEGINS SHIFTING INTO AN UNSETTLED SOUTHWESTERLY PATTERN THE
SOUTHWEST MOUNTAINS WILL AGAIN SEE A CHANCE AT PRECIP DURING THE
AFTERNOON TUESDAY.
THE REMAINDER OF THE EXTENDED IS DOMINATED BY A TROUGH SETTING
OVER THE PACIFIC NORTHWEST AND THE AREA REMAINING IN UNSETTLED
SOUTHWEST FLOW ALOFT. THIS WILL GIVE DAILY CHANCES FOR RAIN AS
WEAK SHORTWAVES STREAM ACROSS THE AREA. BOTH THE GFS AND ECMWF
HAVE TRENDED TOWARDS A SLOWER SOLUTION...ALONG THE LINES OF THE
00Z GFS FROM YESTERDAY...FOR THE PROGRESSION OF THE TROUGH. LOW
LEVEL FLOW WILL BE EASTERLY THROUGH MUCH OF THE EXTENDED...WHICH
WILL GIVE THE AREA DECENT MOISTURE ADVECTION...AND BY MIDWEEK
PRECIPITABLE WATER VALUES WILL BE THREE QUARTERS OF AN INCH TO AN
INCH ACROSS MUCH OF THE AREA. THERE IS SOME CAPE THAT DEVELOPS
DURING THE AFTERNOONS SO ISOLATED THUNDERSTORMS ARE POSSIBLE.
TEMPERATURES WILL REMAIN RELATIVE SEASONABLE THROUGH THE
EXTENDED. HIGHS WILL GENERALLY BE IN THE UPPER 60S TO LOWER 70S.
REIMER
&&
.AVIATION...
A WEAK DISTURBANCE MOVING EAST TO WEST WILL BRING SHOWERS AND
MVFR TO OCCASIONAL IFR CEILINGS TO FOOTHILLS AND MOUNTAIN
LOCATIONS FROM SHERIDAN TO LIVINGSTON THROUGH 18Z. THIS AFTERNOON
WILL SEE SCATTERED SHOWERS AND THUNDERSTORMS DEVELOP ACROSS THE
AREA. MODERATE TO HEAVY RAINFALL WITH THIS ACTIVITY WILL PRODUCE
LOCAL IFR VISIBILITY AND MVFR CEILINGS. AFTER SUNSET TONIGHT AREAS
THAT SAW ANY PRECIPITATION WILL BE FAVORED FOR STRATUS AND FOG
DEVELOPMENT THROUGH THE OVERNIGHT HOURS. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 065 045/062 045/069 047/071 048/070 048/069 047/064
3/T 24/T 32/T 23/T 33/T 33/T 33/T
LVM 060 041/061 039/068 044/068 043/065 043/068 042/064
6/T 43/T 33/T 34/T 44/T 43/T 33/T
HDN 067 046/063 045/069 046/074 048/072 048/072 047/066
3/T 35/T 43/T 23/T 33/T 33/T 33/T
MLS 067 045/062 047/067 046/073 049/072 049/070 048/065
3/T 46/T 45/T 22/T 33/T 32/T 23/T
4BQ 063 046/059 046/066 044/072 048/071 049/069 047/064
3/T 67/T 55/T 22/T 34/T 43/T 33/T
BHK 061 045/060 045/064 044/070 047/069 047/067 045/062
3/T 67/T 66/T 32/T 34/T 43/T 33/T
SHR 061 043/056 042/064 042/069 045/068 045/068 044/064
4/T 46/T 44/T 24/T 43/T 33/T 33/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
940 AM CDT SAT MAY 23 2015
.UPDATE...
ISSUED AT 940 AM CDT SAT MAY 23 2015
STILL LOOKING AT SOME POSSIBLE SPRINKLES ACROSS A SMALL PORTION OF
WEST CENTRAL MINNESOTA LATE MORNING/EARLY AFTERNOON.
OTHERWISE...ANTICIPATE CLOUD COVER INCREASING FROM SOUTH TO NORTH
TODAY...BUT REMAINING SOUTH OF HWY 2. RAP 850MB-700MB RELATIVE
HUMIDITY APPEARS TO HAVE A GOOD HANDLE ON THIS CLOUD SHIELD AND
USED FOR TIMING PURPOSES. MAX TEMPS WILL BE WELL INTO THE 70S
(POSSIBLY 80F) NORTH OF HWY 2 WITH FULL SOLAR...WITH COOLER VALUES
NEAR 70F WITH CLOUDS. DID RAISE MAX TEMPS A BIT NEAR THE
INTERNATIONAL BORDER.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 327 AM CDT SAT MAY 23 2015
ISSUES WILL BE HOW FAR AND WHEN WILL THE PRECIP SPREAD NORTH THE
NEXT FEW DAYS. LARGER UPPER TROUGH OVER UTAH/N ARIZONA THIS
MORNING. THIS WILL SLOWLY MOVE EAST THE NEXT FEW DAYS..AS MOISTURE
CONTINUES TO MOVE NORTH. THE NORTHERN EDGE OF HIGH LEVEL CLOUD
COVER WILL SPREAD OVER THE AREA TODAY WITH SOME MID CLOUDS IN THE
SRN FCST AREA THIS AFTN. OF INTEREST IS A SMALL AREA OF SHOWERS IN
THE SIOUX FALLS AREA. HRRR AND A FEW OTHER SHORT RANGE MODELS DO
BRING A FEW SPITS OF PRECIP NORTHEAST INTO WCNTRL MN (ALEX-ST
CLOUD AREA) LATE MORNING INTO EARLY AFTN. TO BLEND WITH WFO MPX I
DID INSERT A FEW SPRINKLES IN OTTER TAIL AND WADENA COUNTIES LATE
MORNING INTO MID AFTN. BASED ON MOISTURE MOVING NORTH ANY SHOWERS
WILL NOT REACH THE SD/ND BORDER AREA TIL LATE THIS AFTN AND
TRIMMED POPS ACCORDINGLY FOR TODAY. TONIGHT WILL SEE A SHOWER RICK
IN THE SOUTH BUT STUBBORN HIGH PRESSURE TO THE NORTH ALONG THE
CANADIAN BORDER WILL REMAIN IN PLACE SLOWING DOWN ANY NORTHWARD
ADVANCEMENT OF MOISTURE.
SUNDAY WILL SEE DEEPER MOISTURE START TO MOVE INTO SE ND AND THEN
SPREAD NORTH DURING THE DAY. THUS HIGHER POPS...MOSTLY SOUTHERN
FCST AREA. GFS REMAINS A BIT FASTER THAN ECMWF/GEM WHICH KEEP
DVL-GFK AREA DRY THRU SUN EVE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT MAY 23 2015
RAIN CHANCES SPREAD NORTH SUN NIGHT WITH HIGH RAIN CHANCES MONDAY
AS UPPER TROUGH AND SFC LOW MOVE FROM SOUTHERN SD INTO CNTRL/SRN
MN. HIGH PRESSURE DOES REMAIN OVER SOUTHERN MANITOBA AND SOME
MODELS WANT TO KEEP FAR NW FCST AREA DRY EVEN MONDAY. AT THIS TIME
WENT WITH SUPERBLEND OF MODELS AND IDEA OF CATEGORICAL POPS FOR
SHOWERS MONDAY SE 2/3 OF THE FCST AREA. SOME WEAK
INSTABILITY...BUT VERY WEAK...SO DID KEEP SLIGHT CHANCE OF THUNDER
SUN NIGHT THRU MON IN THE GRIDS. PRECIP BEGINS TO MOVE EAST MON
NIGHT. AS FOR HOW MUCH RAINFALL....MOST AREAS IN THE ONE HALF TO
THREE QUARTERS INCH RANGE GFK SOUTH AND EAST AND LESS NORTHWEST.
FOR TUESDAY THROUGH FRIDAY...
NOT A LOT OF AGREEMENT AMONG MODELS ALTHOUGH THEY DO ALL SHOW THE
POTENTIAL FOR THUNDERSTORM ACTIVITY. UPPER FEATURES BECOME OUT OF
PHASE WHEN COMPARING ECMWF AND GFS...UNCHANGED FROM YESTERDAY`S
SOLUTION. ECMWF HAS LONGER WAVES WITH MORE OF A SOUTHWEST FLOW MID
WEEK WHILE GFS HANGS ON TO A DIGGING SHORTWAVE NORTH OF THE BORDER
WITH MORE OF A ZONAL FLOW OVER THE NORTHERN PLAINS. AMOUNT OF
MOISTURE RETURN WILL BE KEY TO COVERAGE AND INTENSITY OF STORMS.
LATEST EXTENDED SUPERBLEND SOLUTION CONTINUES WITH POPS COVERING
MOST OF THE FORECAST AREA MOST OF THE TIME...ONLY ADJUSTMENT WAS TO
SMOOTH OUT MINUTE AREAS OF PCPN/NO PCPN WITHIN THE FGF CWA.
TEMPERATURES WILL BE NEAR NORMAL VALUES WITH DAYTIME HIGHS MOSTLY IN
THE 70S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 705 AM CDT SAT MAY 23 2015
VFR THRU 12Z SUN. EXPECTING AN INCREASE IN HIGH AND MID LEVEL
CLOUD COVER TODAY...THICKEST IN THE SRN RRV AND WCNTRL MN. SOUTH
WINDS GENERALLY NR 10 KTS. NO PRECIP PUT IN THE TAFS THRU 12Z SUN
AS BEST CHC IS BEYOND THEN.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...RIDDLE
LONG TERM...WJB/RIDDLE
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
938 AM CDT SAT MAY 23 2015
.UPDATE...
ISSUED AT 925 AM CDT SAT MAY 23 2015
SATELLITE LOOPS AND SHORT TERM MODELS INDICATE LARGE CLOUD MASS
OVER SOUTH DAKOTA MOVING NORTHWARD ACROSS NORTH DAKOTA THROUGH THE
DAY. LATEST HRRR AND NAM MODELS INDICATE LOW CLOUDS MAKING THEIR
WAY NORTHWARD TOWARDS THE I-94 CORRIDOR THROUGH THE DAY. LOW
CLOUDS IN HETTINGER HAVE SCATTERED OUT...BUT EXPECT THAT WITH TIME
THEY WILL COVER THE FAR SOUTHERN TIER OF COUNTIES FOR MUCH OF THE
AFTERNOON.
REGARDING RAIN CHANCES...WILL KEEP THE MENTION OF RAIN OUT FOR THE
MORNING HOURS AS PER THE EARLY MORNING FORECAST PACKAGE. SHORT
TERM MODELS - INCLUDING THE NAM - INDICATE AFTERNOON SHOWERS
LIFTING NORTHWARD OVER FAR SOUTHWESTERN AND FAR SOUTH CENTRAL
NORTH DAKOTA. A LOOK AT THE BOWMAN RADAR INDICATES LIGHT RADAR
RETURNS IN THE FAR SOUTHWEST PART OF NORTH DAKOTA...AND SUSPECT
RADAR IS PICKING UP ON MID CLOUDS AND/OR VIRGA IN THE AREA.
LIFTING GOING ON IN THE LOW/MID ATMOSPHERE BUT NOT ENOUGH YET TO
YIELD PRECIPITATION REACHING THE GROUND. THE GFS REMAINS VERY
AGGRESSIVE AND IS OVER- FORECASTING THE PRECIPITATION. MINOR
CHANGES TO AFTERNOON RAIN CHANCES...BUT BASICALLY CHANCES ARE FOR
SCATTERED SHOWERS TO BE MAINLY SOUTH OF I-94...PERHAPS A BIT
BETTER FOR SCATTERED SHOWERS TOWARDS THE MEDORA/BEACH AREA DURING
THE AFTERNOON.
BETTER LIFTING AND STRONGER FORCING BEGINS THIS EVENING.
RAISED TEMPERATURES A TAD IN THE FAR NORTH BASED ON CURRENT
TRENDS. OTHERWISE FORECAST ON TRACK.
UPDATE ISSUED AT 620 AM CDT SAT MAY 23 2015
EARLY MORNING WATER VAPOR IMAGERY SHOWS A WAVE MOVING NORTH ACROSS
SOUTH DAKOTA. THIS IS EXPECTED TO BE THE MAIN DRIVER OF THE RAIN
CHANCES TODAY. CURRENT RAP / HRRR SUGGEST ANY RAIN CHANCES SHOULD
HOLD OFF FOR SEVERAL MORE HOURS. THE CURRENT FORECAST BRINGS IN
POPS ACROSS THE SOUTH BY EARLY AFTERNOON...AND WILL MAINTAIN THAT
TIMING FOR THIS UPDATE. MAINLY BLENDED CURRENT CONDITIONS INTO
THE FORECAST WITH ONLY MINOR ADJUSTMENTS MADE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT SAT MAY 23 2015
THE MAIN FOCUS FOR THE SHORT TERM IS TIMING OF RAIN
TODAY/TONIGHT.
THE LATEST TRENDS IN THE 00 UTC MODEL SUITE INDICATE AN EVEN
FURTHER DELAY IN PRECIPITATION ONSET. THE EARLIER NAM AND GEM RUNS
KEPT RAIN OUT OF THE AREA UNTIL TONIGHT. THE GFS AND ECMWF HAVE
FOLLOWED SUIT WITH THEIR LATEST RUNS. FURTHERMORE...THE OO UTC
RUNS OF THE WRF FURTHER INDICATE A DELAY UNTIL THIS AFTERNOON.
THEREFORE...REMOVED ALL MENTION OF PRECIPITATION UNTIL THIS
AFTERNOON. IT APPEARS SOME SCATTERED RAIN SHOWERS ARE POSSIBLE
THIS AFTERNOON...WITH THE BULK OF THE RAIN EXPECTED LATER TONIGHT
INTO TOMORROW AS THE MAIN LOW PRESSURE CENTER EJECTS ACROSS THE
PLAINS. ALSO PUSHED BACK THE MENTION OF THUNDERSTORMS AS THE
LATEST GUIDANCE SUGGESTS INSTABILITY WILL BE CONFINED TO SOUTH
DAKOTA TODAY.
WITH INCREASING CLOUDS AND POSSIBLE RAIN...SOUTHERN NORTH DAKOTA
SHOULD BE THE COOL SPOT TODAY...WITH TEMPERATURES IN THE
60S...WHILE NORTHERN NORTH DAKOTA SEES A LITTLE MORE SUN AND
TEMPERATURES IN THE 70S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 343 AM CDT SAT MAY 23 2015
THE MAIN FORECAST CHALLENGE REMAINS THE RAIN / THUNDERSTORM
CHANCES SUNDAY AND MONDAY. MODEL DIFFERENCES KEEP CONFIDENCE IN
THE OVERALL DETAILS FOR SUNDAY AND MONDAY SOMEWHAT LOW. THE GFS
REMAINS THE MORE ROBUST MODEL IN REGARDS TO QPF ACROSS THE
FORECAST AREA...WHILE THE NAM IS ON THE LOW END OF VALUES. THE
ECMWF IS MORE IN THE MIDDLE...SO WILL CONTINUE TO GO WITH A BLEND
OF SOLUTIONS. THIS KEEPS THE HIGHER RAIN CHANCES AND QPF ACROSS
THE SOUTHERN PART OF NORTH DAKOTA. INSTABILITY IS STILL NOT VERY
HIGH ON SUNDAY...SO HAVE KEPT ANY THUNDERSTORM CHANCES ISOLATED.
AS STATED EARLIER...MODEL SOLUTIONS STILL VARY ON MONDAY...AND
THIS ALSO INFLUENCES THE AMOUNT OF INSTABILITY THEY PRODUCE. WILL
BUMP UP THE THUNDERSTORM PROBABILITIES ON MONDAY WITH MORE
INSTABILITY SHOWN BY THE GFS...BUT WILL KEEP THINGS IN THE CHANCE
CATEGORY.
IN REGARDS TO RAINFALL AMOUNTS...WE ARE STILL SHOWING THE HIGHEST
TOTALS IN SOUTHWEST NORTH DAKOTA WHERE AMOUNTS OF 1.00 - 1.25
INCHES ARE FORECAST THROUGH TUESDAY MORNING. THE LOWEST AMOUNTS
REMAIN IN THE NORTH WHERE WE HAVE 0.25 - 0.50 INCH THROUGH THAT
SAME TIME PERIOD.
THE UNSETTLED PATTERN CONTINUES MUCH OF NEXT WEEK WITH PERIODIC
WAVES MOVING THROUGH THE REGION. HAVE STAYED CLOSE TO A BLENDED
MODEL SOLUTION WHICH KEEPS SMALL POPS MOST OF NEXT WEEK.
INSTABILITY OVERALL IS NOT THAT IMPRESSIVE...SO WILL KEEP ANY
THUNDERSTORM CHANCES ISOLATED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 605 AM CDT SAT MAY 23 2015
VFR CONDITIONS ARE EXPECTED AT KISN/KMOT THROUGH THE TAF PERIOD.
VFR CONDITIONS WILL LIKELY DETERIORATE TO MFVR WITH RAIN AT
KDIK/KBIS/KJMS LATE TONIGHT...WITH THE BEST CHANCE FOR RAIN CLOSER
TO 12Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...AJ
LONG TERM...CK
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
711 AM CDT SAT MAY 23 2015
.UPDATE...
ISSUED AT 705 AM CDT SAT MAY 23 2015
HRRR WAS RIGHT ON THE MONEY WITH SOME LIGHT RAIN SHOWERS SPREADING
NORTHEAST THRU ECNTRL/SE SD INTO SW MN. THESE WILL MOVE
NORTHEAST...IT REMAINS TO BE SEEN HOW THEY HOLD TOGETHER.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 327 AM CDT SAT MAY 23 2015
ISSUES WILL BE HOW FAR AND WHEN WILL THE PRECIP SPREAD NORTH THE
NEXT FEW DAYS. LARGER UPPER TROUGH OVER UTAH/N ARIZONA THIS
MORNING. THIS WILL SLOWLY MOVE EAST THE NEXT FEW DAYS..AS MOISTURE
CONTINUES TO MOVE NORTH. THE NORTHERN EDGE OF HIGH LEVEL CLOUD
COVER WILL SPREAD OVER THE AREA TODAY WITH SOME MID CLOUDS IN THE
SRN FCST AREA THIS AFTN. OF INTEREST IS A SMALL AREA OF SHOWERS IN
THE SIOUX FALLS AREA. HRRR AND A FEW OTHER SHORT RANGE MODELS DO
BRING A FEW SPITS OF PRECIP NORTHEAST INTO WCNTRL MN (ALEX-ST
CLOUD AREA) LATE MORNING INTO EARLY AFTN. TO BLEND WITH WFO MPX I
DID INSERT A FEW SPRINKLES IN OTTER TAIL AND WADENA COUNTIES LATE
MORNING INTO MID AFTN. BASED ON MOISTURE MOVING NORTH ANY SHOWERS
WILL NOT REACH THE SD/ND BORDER AREA TIL LATE THIS AFTN AND
TRIMMED POPS ACCORDINGLY FOR TODAY. TONIGHT WILL SEE A SHOWER RICK
IN THE SOUTH BUT STUBBORN HIGH PRESSURE TO THE NORTH ALONG THE
CANADIAN BORDER WILL REMAIN IN PLACE SLOWING DOWN ANY NORTHWARD
ADVANCEMENT OF MOISTURE.
SUNDAY WILL SEE DEEPER MOISTURE START TO MOVE INTO SE ND AND THEN
SPREAD NORTH DURING THE DAY. THUS HIGHER POPS...MOSTLY SOUTHERN
FCST AREA. GFS REMAINS A BIT FASTER THAN ECMWF/GEM WHICH KEEP
DVL-GFK AREA DRY THRU SUN EVE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT MAY 23 2015
RAIN CHANCES SPREAD NORTH SUN NIGHT WITH HIGH RAIN CHANCES MONDAY
AS UPPER TROUGH AND SFC LOW MOVE FROM SOUTHERN SD INTO CNTRL/SRN
MN. HIGH PRESSURE DOES REMAIN OVER SOUTHERN MANITOBA AND SOME
MODELS WANT TO KEEP FAR NW FCST AREA DRY EVEN MONDAY. AT THIS TIME
WENT WITH SUPERBLEND OF MODELS AND IDEA OF CATEGORIAL POPS FOR
SHOWERS MONDAY SE 2/3 OF THE FCST AREA. SOME WEAK
INSTABILITY...BUT VERY WEAK...SO DID KEEP SLIGHT CHANCE OF THUNDER
SUN NIGHT THRU MON IN THE GRIDS. PRECIP BEGINS TO MOVE EAST MON
NIGHT. AS FOR HOW MUCH RAINFALL....MOST AREAS IN THE ONE HALF TO
THREE QUARTERS INCH RANGE GFK SOUTH AND EAST AND LESS NORTHWEST.
FOR TUESDAY THROUGH FRIDAY...
NOT A LOT OF AGREEMENT AMONG MODELS ALTHOUGH THEY DO ALL SHOW THE
POTENTIAL FOR THUNDERSTORM ACTIVITY. UPPER FEATURES BECOME OUT OF
PHASE WHEN COMPARING ECMWF AND GFS...UNCHANGED FROM YESTERDAY`S
SOLUTION. ECMWF HAS LONGER WAVES WITH MORE OF A SOUTHWEST FLOW MID
WEEK WHILE GFS HANGS ON TO A DIGGING SHORTWAVE NORTH OF THE BORDER
WITH MORE OF A ZONAL FLOW OVER THE NORTHERN PLAINS. AMOUNT OF
MOISTURE RETURN WILL BE KEY TO COVERAGE AND INTENSITY OF STORMS.
LATEST EXTENDED SUPERBLEND SOLUTION CONTINUES WITH POPS COVERING
MOST OF THE FORECAST AREA MOST OF THE TIME...ONLY ADJUSTMENT WAS TO
SMOOTH OUT MINUTE AREAS OF PCPN/NO PCPN WITHIN THE FGF CWA.
TEMPERATURES WILL BE NEAR NORMAL VALUES WITH DAYTIME HIGHS MOSTLY IN
THE 70S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 705 AM CDT SAT MAY 23 2015
VFR THRU 12Z SUN. EXPECTING AN INCREASE IN HIGH AND MID LEVEL
CLOUD COVER TODAY...THICKEST IN THE SRN RRV AND WCNTRL MN. SOUTH
WINDS GENERALLY NR 10 KTS. NO PRECIP PUT IN THE TAFS THRU 12Z SUN
AS BEST CHC IS BEYOND THEN.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...RIDDLE
LONG TERM...WJB/RIDDLE
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
623 AM CDT SAT MAY 23 2015
.UPDATE...
ISSUED AT 620 AM CDT SAT MAY 23 2015
EARLY MORNING WATER VAPOR IMAGERY SHOWS A WAVE MOVING NORTH ACROSS
SOUTH DAKOTA. THIS IS EXPECTED TO BE THE MAIN DRIVER OF THE RAIN
CHANCES TODAY. CURRENT RAP / HRRR SUGGEST ANY RAIN CHANCES SHOULD
HOLD OFF FOR SEVERAL MORE HOURS. THE CURRENT FORECAST BRINGS IN
POPS ACROSS THE SOUTH BY EARLY AFTERNOON...AND WILL MAINTAIN THAT
TIMING FOR THIS UPDATE. MAINLY BLENDED CURRENT CONDITIONS INTO
THE FORECAST WITH ONLY MINOR ADJUSTMENTS MADE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT SAT MAY 23 2015
THE MAIN FOCUS FOR THE SHORT TERM IS TIMING OF RAIN
TODAY/TONIGHT.
THE LATEST TRENDS IN THE 00 UTC MODEL SUITE INDICATE AN EVEN
FURTHER DELAY IN PRECIPITATION ONSET. THE EARLIER NAM AND GEM RUNS
KEPT RAIN OUT OF THE AREA UNTIL TONIGHT. THE GFS AND ECMWF HAVE
FOLLOWED SUIT WITH THEIR LATEST RUNS. FURTHERMORE...THE OO UTC
RUNS OF THE WRF FURTHER INDICATE A DELAY UNTIL THIS AFTERNOON.
THEREFORE...REMOVED ALL MENTION OF PRECIPITATION UNTIL THIS
AFTERNOON. IT APPEARS SOME SCATTERED RAIN SHOWERS ARE POSSIBLE
THIS AFTERNOON...WITH THE BULK OF THE RAIN EXPECTED LATER TONIGHT
INTO TOMORROW AS THE MAIN LOW PRESSURE CENTER EJECTS ACROSS THE
PLAINS. ALSO PUSHED BACK THE MENTION OF THUNDERSTORMS AS THE
LATEST GUIDANCE SUGGESTS INSTABILITY WILL BE CONFINED TO SOUTH
DAKOTA TODAY.
WITH INCREASING CLOUDS AND POSSIBLE RAIN...SOUTHERN NORTH DAKOTA
SHOULD BE THE COOL SPOT TODAY...WITH TEMPERATURES IN THE
60S...WHILE NORTHERN NORTH DAKOTA SEES A LITTLE MORE SUN AND
TEMPERATURES IN THE 70S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 343 AM CDT SAT MAY 23 2015
THE MAIN FORECAST CHALLENGE REMAINS THE RAIN / THUNDERSTORM
CHANCES SUNDAY AND MONDAY. MODEL DIFFERENCES KEEP CONFIDENCE IN
THE OVERALL DETAILS FOR SUNDAY AND MONDAY SOMEWHAT LOW. THE GFS
REMAINS THE MORE ROBUST MODEL IN REGARDS TO QPF ACROSS THE
FORECAST AREA...WHILE THE NAM IS ON THE LOW END OF VALUES. THE
ECMWF IS MORE IN THE MIDDLE...SO WILL CONTINUE TO GO WITH A BLEND
OF SOLUTIONS. THIS KEEPS THE HIGHER RAIN CHANCES AND QPF ACROSS
THE SOUTHERN PART OF NORTH DAKOTA. INSTABILITY IS STILL NOT VERY
HIGH ON SUNDAY...SO HAVE KEPT ANY THUNDERSTORM CHANCES ISOLATED.
AS STATED EARLIER...MODEL SOLUTIONS STILL VARY ON MONDAY...AND
THIS ALSO INFLUENCES THE AMOUNT OF INSTABILITY THEY PRODUCE. WILL
BUMP UP THE THUNDERSTORM PROBABILITIES ON MONDAY WITH MORE
INSTABILITY SHOWN BY THE GFS...BUT WILL KEEP THINGS IN THE CHANCE
CATEGORY.
IN REGARDS TO RAINFALL AMOUNTS...WE ARE STILL SHOWING THE HIGHEST
TOTALS IN SOUTHWEST NORTH DAKOTA WHERE AMOUNTS OF 1.00 - 1.25
INCHES ARE FORECAST THROUGH TUESDAY MORNING. THE LOWEST AMOUNTS
REMAIN IN THE NORTH WHERE WE HAVE 0.25 - 0.50 INCH THROUGH THAT
SAME TIME PERIOD.
THE UNSETTLED PATTERN CONTINUES MUCH OF NEXT WEEK WITH PERIODIC
WAVES MOVING THROUGH THE REGION. HAVE STAYED CLOSE TO A BLENDED
MODEL SOLUTION WHICH KEEPS SMALL POPS MOST OF NEXT WEEK.
INSTABILITY OVERALL IS NOT THAT IMPRESSIVE...SO WILL KEEP ANY
THUNDERSTORM CHANCES ISOLATED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 605 AM CDT SAT MAY 23 2015
VFR CONDITIONS ARE EXPECTED AT KISN/KMOT THROUGH THE TAF PERIOD.
VFR CONDITIONS WILL LIKELY DETERIORATE TO MFVR WITH RAIN AT
KDIK/KBIS/KJMS LATE TONIGHT...WITH THE BEST CHANCE FOR RAIN CLOSER
TO 12Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CK
SHORT TERM...AJ
LONG TERM...CK
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
953 AM CDT SAT MAY 23 2015
.UPDATE...
BIGGEST CHANGE TO THE FORECAST WAS TO UP RAIN CHANCES ACROSS THE
RIO GRANDE PLAINS BY 10 PERCENT THIS AFTERNOON. ALSO ADJUSTED
HIGHS FOR TODAY ACROSS THE HILL COUNTRY UP A DEGREE GIVEN CURRENT
OBSERVATIONS. OTHERWISE ONLY MINOR CHANGES MADE AND TRENDED ALL
HOURLY GRIDS BASED ON MORNING SURFACE OBSERVATIONS.
&&
.DISCUSSION...
ALL OF THE MORNING MESOSCALE/HIGH-RES MODELS CONTINUE TO TREND
EARLIER FOR THE LINE OF SHOWERS AND THUNDERSTORMS THIS EVENING.
MOST HAVE IT DEVELOPING OVER THE DEL RIO AREA AROUND 5 PM AND
GETTING INTO THE I-35 CORRIDOR BETWEEN 9 AND MIDNIGHT. HEAVY RAINS
AND SEVERE WEATHER ARE STILL LOOKING LIKELY WITH THIS SYSTEM...AND
WILL LOOK IN DEPTH INTO THAT IN THE AFTERNOON PACKAGE AND
DISCUSSION. FOR THE REST OF TODAY SCATTERED SHOWERS AND
THUNDERSTORMS SHOULD INCREASE IN COVERAGE THIS AFTERNOON AHEAD OF
THE LINE.
WILL CONTINUE TO STRESS THAT ANYONE ON LOCAL RIVERS AND LAKES THIS
HOLIDAY WEEKEND...TODAY THROUGH MONDAY...NEED TO PAY VERY CLOSE
ATTENTION TO THE WEATHER AND ANY WARNINGS THAT ARE ISSUED. HAVE
MULTIPLE WAYS TO RECEIVE WEATHER INFORMATION...HAVE A PLAN TO
SEEK SHELTER OR GET TO SAFETY SHOULD SEVERE WEATHER OR FLOODING
OCCUR...AND ALWAYS REMEMBER TURN AROUND...DONT DROWN.
&&
.PREV DISCUSSION... /ISSUED 653 AM CDT SAT MAY 23 2015/
AVIATION... /12Z TAF UPDATE/
ACTIVE CONVECTION IS IMPACTING AUS AT THE TIME OF TAF ISSUANCE.
THE SCATTERED SHOWERS AND THUNDERSTORMS LOOK TO BE PULLING NORTH
OF THE SAT/SSF VCNTYS FOR A FEW HOURS AND COULD LIFT NORTH OF THE
AUS AREA IN THE NEXT HOUR OR TWO AS WELL. DEEP TROPICAL MOISTURE
AND ANOTHER RIPPLE OF ENERGY NEAR DRT COULD BEGIN TO IMPACT THE
I-35 SITES AGAIN BY 15Z. CONVECTION SHOULD BE SCATTERED SO TIMING
IS IN LOW CONFIDENCE FOR TODAY. CONFIDENCE INCREASES FOR THE
PREVAILING THUNDER PERIOD...ALTHOUGH THE TIME WINDOW MAY BE ABLE
TO COMPRESS ONCE THE MUCH ANTICIPATED STORM COMPLEX BEGINS TO TAKE
SHAPE. AFTER THE COMPLEX IS SPECULATED TO PASS EAST OF I-35 TOWARD
DAYBREAK...WILL CONTINUE PREVAILING SHOWERS...WITH SOME POSSIBLE
FURTHER IMPROVEMENTS TO FOLLOW DURING THE DAYLIGHT HOURS SUNDAY.
WILL KEEP CONDITIONS FAIRLY PESSIMISTIC IN CASE THE SYSTEM SLOWS
DOWN.
PREV DISCUSSION... /ISSUED 314 AM CDT SAT MAY 23 2015/
SHORT TERM (TODAY THROUGH SUNDAY)...
MODERATE TO HEAVY RAINFALL IS GETTING AN EARLY START WITH
CONVECTION INCREASING WEST OF HIGHWAY 83. THIS IS ALL ASSOCIATED
WITH INCREASING LIFT AHEAD OF THE MAIN UPPER LOW WHICH IS STILL
OVER UTAH/ARIZONA PER 00Z UPPER AIR ANALYSIS AND LATEST WATER
VAPOR IMAGERY. RAINFALL RATES WITH THIS ACTIVITY ARE GENERALLY AT
1-2 INCHES PER HOUR AND WE HAVE ALREADY ISSUED ONE FLOOD ADVISORY.
THE HRRR IS ZEROING IN ON THIS AREA WHERE RAIN IS CURRENTLY
INCREASING AND IS COMING UP WITH SOME HIGH TOTALS THIS MORNING.
BECAUSE OF THIS EARLY THREAT OF HEAVY RAINFALL...WILL GO AHEAD
AND START THE FLASH FLOOD WATCH NOW. THIS WILL BE A BIT TOO EARLY
FOR THE EASTERN ZONES...BUT WANT TO AVOID CONFUSION WITH A
SEGMENTED PRODUCT. HIGH-RES MODEL GUIDANCE CONTINUES TO SHOW THE
WESTERN CWA AS THE FAVORED AREA FOR CONVECTION LATER THIS MORNING
BEFORE SPREADING ACROSS THE AREA THIS AFTERNOON. RAIN LOOKS LIKELY
FOR TODAY WITH 60/70 POPS ACROSS THE CWA. INDIVIDUAL CELLS COULD
CONTAIN HEAVY RAINFALL AND SOME TRAINING OF CELLS IS ALSO
POSSIBLE.
THE MAIN FORCING WITH THIS INITIAL WAVE OF LIFT ASSOCIATED WITH
THE UPPER LOW WILL BEGIN TO ARRIVE TO THE WESTERN ZONES LATE THIS
AFTERNOON AND EVENING. CONFIDENCE IS HIGH THAT A LINE OF SHOWERS
AND THUNDERSTORMS WILL DEVELOP WITH THIS LIFT AND STRETCH ACROSS A
LARGE PORTION OF TEXAS. THERE ARE SOME DISCREPANCIES WITH THE
GUIDANCE ON THE EXACT TIMING OF THIS WITH MOST MODELS SOMEWHERE
BETWEEN THE 21Z TO 03Z TIME FRAME...WITH SOME OF THE HIGH-RES
GUIDANCE BEING THE EARLIEST. THIS LINE IS EXPECTED TO SLOWLY MARCH
THROUGH THE CWA OVERNIGHT AND IS EXPECTED TO AVERAGE A QUICK 1-3
INCHES OF RAIN AS IT MOVES ACROSS. OVERNIGHT RAIN ON TOP OF ANY
RAINFALL THAT OCCURS TODAY WILL NOT BE ABLE TO SOAK INTO THE
GROUND...AS SOILS REMAIN QUITE SATURATED FROM A VERY WET SPRING.
MOST OF THE RAIN WILL RUNOFF INTO CREEKS...STREAMS AND RIVERS AND
FLOODING IS ONCE AGAIN LIKELY.
ALTHOUGH FLOODING RAINS IS OF THE HIGHEST CONCERN ON THIS HOLIDAY
WEEKEND...THERE IS THE THREAT OF SEVERE WEATHER AS WELL. SEVERE
PARAMETERS ARE FAVORABLE FOR SEVERE STORMS...BUT AM CONCERNED WITH
THE HIGHER COVERAGE OF STORMS AND THE EFFECT THAT COULD HAVE BY
CLUTTERING UP THE NEAR-STORM ENVIRONMENT. HOWEVER...CANT RULE OUT
BOWING SEGMENTS WITHIN THE MAIN LINE THAT COULD PRODUCE SOME
SEVERE WINDS. ALSO...LOW-LEVEL WINDS WILL INCREASE AND SOME
TURNING IN THE PROFILE WILL POSE AN ISOLATED TORNADO THREAT WITH
ANY STRONGER LINE SEGMENTS AS WELL AS THE MAIN LINE MOVES THROUGH
THE AREA.
BY SUNDAY MORNING...THE LINE OF STORMS WILL BE NEARING THE EASTERN
COUNTIES AND SHOULD MOVE OUT OF THE CWA SOMETIME AROUND 18Z. THE
THREAT OF FLOODING RAINS AND SOME SEVERE WEATHER WILL CONTINUE
SUNDAY MORNING. BY SUNDAY AFTERNOON...CAPE VALUES INCREASE TO
ABOVE 3000 J/KG WHICH IS SOMEWHAT INITIALLY CONCERNING.
HOWEVER...FORECAST SOUNDINGS SHOW DECENT AMOUNTS OF DRYING ALOFT
BEHIND THE INITIAL WAVE WHICH SHOULD LIMIT ACTIVITY. ALSO...THE
ENVIRONMENT SHOULD BE PRETTY WORKED OVER FROM THE OVERNIGHT AND
MORNING ACTIVITY. THE ONE AREA TO WATCH WILL BE THE WESTERN
COUNTIES WHERE THE MOST RECOVERY TIME WILL BE AND SOME HIGH-RES
MEMBERS ARE SHOWING THE POTENTIAL FOR REDEVELOPMENT SUNDAY
AFTERNOON IN THIS GENERAL AREA.
RAINFALL AMOUNTS THIS MORNING THROUGH SUNDAY WILL AVERAGE 1-4
INCHES WITH THE HIGHER AMOUNTS NEAR THE I-35 CORRIDOR. WE MUST
CONTINUE TO STRESS TO ANYONE ON LOCAL RIVERS AND LAKES THIS
HOLIDAY WEEKEND TO PAY VERY CLOSE ATTENTION TO THE WEATHER AND ANY
WARNINGS THAT ARE ISSUED. HAVE A PLAN IN PLACE TO SEEK SHELTER
AND ALWAYS REMEMBER TO TURN AROUND...DONT DROWN.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
SHOULD SEE A LULL IN ACTIVITY EARLY SUNDAY NIGHT...BUT THIS
SHOULD UNFORTUNATELY BE BRIEF. CURRENTLY ON WATER VAPOR
IMAGERY...ANOTHER IMPULSE ASSOCIATED WITH THE MAIN UPPER LOW CAN
BE SEEN NEAR THE WASHINGTON AND OREGON BORDER. 00Z GUIDANCE SEEMS
TO HAVE PICKED UP ON THIS FEATURE QUITE WELL AND BRINGS IT INTO
TEXAS FOR MONDAY /MEMORIAL DAY/. SUBSEQUENTLY...THE 00Z MODEL
GUIDANCE HAS INCREASED THE QPF AMOUNTS FORECASTED FOR MONDAY
AFTERNOON. THE GFS IS THE HIGHEST OF ALL GUIDANCE WITH ANOTHER 2
INCHES OF RAIN FOR THE I-35 CORRIDOR. WENT AHEAD AND INCREASED
RAIN TOTALS IN THE OFFICIAL FORECAST...BUT NOT QUITE AS HIGH AS
THE GFS IS ADVERTISING. IF CONFIDENCE INCREASES THAT UP TO ANOTHER
2 INCHES OF RAIN WILL FALL ON MONDAY....THE FLASH FLOOD WATCH WILL
NEED TO BE EXTENDED AT A LATER TIME. CAPE/SHEAR VALUES WILL
SUPPORT THE THREAT OF SEVERE WEATHER AS WELL. FORECAST SOUNDINGS
DUE SHOW THE THREAT FOR HAIL...DAMAGING WINDS AND POSSIBLE
ISOLATED TORNADOES FOR MONDAY AFTERNOON. THE OVERALL THREAT FOR
TORNADOES WILL BE HIGHLY DEPENDENT ON THE OVERALL COVERAGE OF
ACTIVITY AND IF ANY DISCRETE SUPERCELLS ARE AVAILABLE TO DEVELOP.
AGAIN...ANYONE OUTDOORS ON THE HOLIDAY NEED TO MAKE SURE TO HAVE A
PLAN AND BE READY TO SEEK SHELTER.
THE UPPER AIR PATTERN BECOMES MORE ZONAL ON TUESDAY WITH WEAK
RIDGING ON WEDNESDAY. OVERALL COVERAGE OF ACTIVITY SHOULD DECREASE
FOR MID-WEEK. POPS WILL SLIGHTLY INCREASE ONCE AGAIN TOWARDS THE
END OF THE WORK WEEK AS THE NEXT DISTURBANCE NEARS THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 81 68 81 71 82 / 60 90 60 40 60
AUSTIN BERGSTROM INTL AIRPORT 81 68 81 70 82 / 60 90 70 40 60
NEW BRAUNFELS MUNI AIRPORT 82 68 82 71 82 / 60 90 60 40 60
BURNET MUNI AIRPORT 79 66 80 69 81 / 60 90 60 30 50
DEL RIO INTL AIRPORT 82 68 89 70 87 / 80 70 30 20 40
GEORGETOWN MUNI AIRPORT 80 68 80 70 82 / 60 90 60 40 60
HONDO MUNI AIRPORT 82 66 84 70 82 / 70 90 50 30 60
SAN MARCOS MUNI AIRPORT 81 68 80 70 82 / 60 90 60 40 60
LA GRANGE - FAYETTE REGIONAL 83 69 80 71 82 / 40 80 80 50 70
SAN ANTONIO INTL AIRPORT 82 68 82 72 83 / 60 90 60 30 60
STINSON MUNI AIRPORT 83 69 83 72 83 / 60 90 60 30 60
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SUNDAY EVENING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DE WITT...DIMMIT...EDWARDS...FAYETTE...FRIO...
GILLESPIE...GONZALES...GUADALUPE...HAYS...KARNES...KENDALL...KERR...
KINNEY...LAVACA...LEE...LLANO...MAVERICK...MEDINA...REAL...TRAVIS...
UVALDE...VAL VERDE...WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...10
SYNOPTIC/GRIDS...TREADWAY
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
653 AM CDT SAT MAY 23 2015
.AVIATION... /12Z TAF UPDATE/
ACTIVE CONVECTION IS IMPACTING AUS AT THE TIME OF TAF ISSUANCE.
THE SCATTERED SHOWERS AND THUNDERSTORMS LOOK TO BE PULLING NORTH
OF THE SAT/SSF VCNTYS FOR A FEW HOURS AND COULD LIFT NORTH OF THE
AUS AREA IN THE NEXT HOUR OR TWO AS WELL. DEEP TROPICAL MOISTURE
AND ANOTHER RIPPLE OF ENERGY NEAR DRT COULD BEGIN TO IMPACT THE
I-35 SITES AGAIN BY 15Z. CONVECTION SHOULD BE SCATTERED SO TIMING
IS IN LOW CONFIDENCE FOR TODAY. CONFIDIDENCE INCREASES FOR THE
PREVAILING THUNDER PERIOD...ALTHOUGH THE TIME WINDOW MAY BE ABLE
TO COMPRESS ONCE THE MUCH ANTICIPATED STORM COMPLEX BEGINS TO TAKE
SHAPE. AFTER THE COMPLEX IS SPECULATED TO PASS EAST OF I-35
TOWARD DAYBREAK...WILL CONTINUE PREVAILING SHOWERS...WITH SOME
POSSIBLE FURTHER IMPROVEMENTS TO FOLLOW DURING THE DAYLIGHT HOURS
SUNDAY. WILL KEEP CONDITIONS FAIRLY PESSEMISTIC IN CASE THE SYSTEM
SLOWS DOWN.
&&
.PREV DISCUSSION... /ISSUED 314 AM CDT SAT MAY 23 2015/
SHORT TERM (TODAY THROUGH SUNDAY)...
MODERATE TO HEAVY RAINFALL IS GETTING AN EARLY START WITH
CONVECTION INCREASING WEST OF HIGHWAY 83. THIS IS ALL ASSOCIATED
WITH INCREASING LIFT AHEAD OF THE MAIN UPPER LOW WHICH IS STILL
OVER UTAH/ARIZONA PER 00Z UPPER AIR ANALYSIS AND LATEST WATER
VAPOR IMAGERY. RAINFALL RATES WITH THIS ACTIVITY ARE GENERALLY AT
1-2 INCHES PER HOUR AND WE HAVE ALREADY ISSUED ONE FLOOD ADVISORY.
THE HRRR IS ZEROING IN ON THIS AREA WHERE RAIN IS CURRENTLY
INCREASING AND IS COMING UP WITH SOME HIGH TOTALS THIS MORNING.
BECAUSE OF THIS EARLY THREAT OF HEAVY RAINFALL...WILL GO AHEAD
AND START THE FLASH FLOOD WATCH NOW. THIS WILL BE A BIT TOO EARLY
FOR THE EASTERN ZONES...BUT WANT TO AVOID CONFUSION WITH A
SEGMENTED PRODUCT. HIGH-RES MODEL GUIDANCE CONTINUES TO SHOW THE
WESTERN CWA AS THE FAVORED AREA FOR CONVECTION LATER THIS MORNING
BEFORE SPREADING ACROSS THE AREA THIS AFTERNOON. RAIN LOOKS LIKELY
FOR TODAY WITH 60/70 POPS ACROSS THE CWA. INDIVIDUAL CELLS COULD
CONTAIN HEAVY RAINFALL AND SOME TRAINING OF CELLS IS ALSO
POSSIBLE.
THE MAIN FORCING WITH THIS INITIAL WAVE OF LIFT ASSOCIATED WITH
THE UPPER LOW WILL BEGIN TO ARRIVE TO THE WESTERN ZONES LATE THIS
AFTERNOON AND EVENING. CONFIDENCE IS HIGH THAT A LINE OF SHOWERS
AND THUNDERSTORMS WILL DEVELOP WITH THIS LIFT AND STRETCH ACROSS A
LARGE PORTION OF TEXAS. THERE ARE SOME DISCREPANCIES WITH THE
GUIDANCE ON THE EXACT TIMING OF THIS WITH MOST MODELS SOMEWHERE
BETWEEN THE 21Z TO 03Z TIME FRAME...WITH SOME OF THE HIGH-RES
GUIDANCE BEING THE EARLIEST. THIS LINE IS EXPECTED TO SLOWLY MARCH
THROUGH THE CWA OVERNIGHT AND IS EXPECTED TO AVERAGE A QUICK 1-3
INCHES OF RAIN AS IT MOVES ACROSS. OVERNIGHT RAIN ON TOP OF ANY
RAINFALL THAT OCCURS TODAY WILL NOT BE ABLE TO SOAK INTO THE
GROUND...AS SOILS REMAIN QUITE SATURATED FROM A VERY WET SPRING.
MOST OF THE RAIN WILL RUNOFF INTO CREEKS...STREAMS AND RIVERS AND
FLOODING IS ONCE AGAIN LIKELY.
ALTHOUGH FLOODING RAINS IS OF THE HIGHEST CONCERN ON THIS HOLIDAY
WEEKEND...THERE IS THE THREAT OF SEVERE WEATHER AS WELL. SEVERE
PARAMETERS ARE FAVORABLE FOR SEVERE STORMS...BUT AM CONCERNED WITH
THE HIGHER COVERAGE OF STORMS AND THE EFFECT THAT COULD HAVE BY
CLUTTERING UP THE NEAR-STORM ENVIRONMENT. HOWEVER...CANT RULE OUT
BOWING SEGMENTS WITHIN THE MAIN LINE THAT COULD PRODUCE SOME
SEVERE WINDS. ALSO...LOW-LEVEL WINDS WILL INCREASE AND SOME
TURNING IN THE PROFILE WILL POSE AN ISOLATED TORNADO THREAT WITH
ANY STRONGER LINE SEGMENTS AS WELL AS THE MAIN LINE MOVES THROUGH
THE AREA.
BY SUNDAY MORNING...THE LINE OF STORMS WILL BE NEARING THE EASTERN
COUNTIES AND SHOULD MOVE OUT OF THE CWA SOMETIME AROUND 18Z. THE
THREAT OF FLOODING RAINS AND SOME SEVERE WEATHER WILL CONTINUE
SUNDAY MORNING. BY SUNDAY AFTERNOON...CAPE VALUES INCREASE TO
ABOVE 3000 J/KG WHICH IS SOMEWHAT INITIALLY CONCERNING.
HOWEVER...FORECAST SOUNDINGS SHOW DECENT AMOUNTS OF DRYING ALOFT
BEHIND THE INITIAL WAVE WHICH SHOULD LIMIT ACTIVITY. ALSO...THE
ENVIRONMENT SHOULD BE PRETTY WORKED OVER FROM THE OVERNIGHT AND
MORNING ACTIVITY. THE ONE AREA TO WATCH WILL BE THE WESTERN
COUNTIES WHERE THE MOST RECOVERY TIME WILL BE AND SOME HIGH-RES
MEMBERS ARE SHOWING THE POTENTIAL FOR REDEVELOPMENT SUNDAY
AFTERNOON IN THIS GENERAL AREA.
RAINFALL AMOUNTS THIS MORNING THROUGH SUNDAY WILL AVERAGE 1-4
INCHES WITH THE HIGHER AMOUNTS NEAR THE I-35 CORRIDOR. WE MUST
CONTINUE TO STRESS TO ANYONE ON LOCAL RIVERS AND LAKES THIS
HOLIDAY WEEKEND TO PAY VERY CLOSE ATTENTION TO THE WEATHER AND ANY
WARNINGS THAT ARE ISSUED. HAVE A PLAN IN PLACE TO SEEK SHELTER
AND ALWAYS REMEMBER TO TURN AROUND...DONT DROWN.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
SHOULD SEE A LULL IN ACTIVITY EARLY SUNDAY NIGHT...BUT THIS
SHOULD UNFORTUNATELY BE BRIEF. CURRENTLY ON WATER VAPOR
IMAGERY...ANOTHER IMPULSE ASSOCIATED WITH THE MAIN UPPER LOW CAN
BE SEEN NEAR THE WASHINGTON AND OREGON BORDER. 00Z GUIDANCE SEEMS
TO HAVE PICKED UP ON THIS FEATURE QUITE WELL AND BRINGS IT INTO
TEXAS FOR MONDAY /MEMORIAL DAY/. SUBSEQUENTLY...THE 00Z MODEL
GUIDANCE HAS INCREASED THE QPF AMOUNTS FORECASTED FOR MONDAY
AFTERNOON. THE GFS IS THE HIGHEST OF ALL GUIDANCE WITH ANOTHER 2
INCHES OF RAIN FOR THE I-35 CORRIDOR. WENT AHEAD AND INCREASED
RAIN TOTALS IN THE OFFICIAL FORECAST...BUT NOT QUITE AS HIGH AS
THE GFS IS ADVERTISING. IF CONFIDENCE INCREASES THAT UP TO ANOTHER
2 INCHES OF RAIN WILL FALL ON MONDAY....THE FLASH FLOOD WATCH WILL
NEED TO BE EXTENDED AT A LATER TIME. CAPE/SHEAR VALUES WILL
SUPPORT THE THREAT OF SEVERE WEATHER AS WELL. FORECAST SOUNDINGS
DUE SHOW THE THREAT FOR HAIL...DAMAGING WINDS AND POSSIBLE
ISOLATED TORNADOES FOR MONDAY AFTERNOON. THE OVERALL THREAT FOR
TORNADOES WILL BE HIGHLY DEPENDENT ON THE OVERALL COVERAGE OF
ACTIVITY AND IF ANY DISCRETE SUPERCELLS ARE AVAILABLE TO DEVELOP.
AGAIN...ANYONE OUTDOORS ON THE HOLIDAY NEED TO MAKE SURE TO HAVE A
PLAN AND BE READY TO SEEK SHELTER.
THE UPPER AIR PATTERN BECOMES MORE ZONAL ON TUESDAY WITH WEAK
RIDGING ON WEDNESDAY. OVERALL COVERAGE OF ACTIVITY SHOULD DECREASE
FOR MID-WEEK. POPS WILL SLIGHTLY INCREASE ONCE AGAIN TOWARDS THE
END OF THE WORK WEEK AS THE NEXT DISTURBANCE NEARS THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 81 68 81 71 82 / 60 90 60 40 60
AUSTIN BERGSTROM INTL AIRPORT 81 68 81 70 82 / 60 90 70 40 60
NEW BRAUNFELS MUNI AIRPORT 82 68 82 71 82 / 60 90 60 40 60
BURNET MUNI AIRPORT 79 66 80 69 81 / 50 90 60 30 50
DEL RIO INTL AIRPORT 82 68 89 70 87 / 70 70 30 20 40
GEORGETOWN MUNI AIRPORT 80 68 80 70 82 / 50 90 60 40 60
HONDO MUNI AIRPORT 82 66 84 70 82 / 70 90 50 30 60
SAN MARCOS MUNI AIRPORT 81 68 80 70 82 / 60 90 60 40 60
LA GRANGE - FAYETTE REGIONAL 83 69 80 71 82 / 40 80 80 50 70
SAN ANTONIO INTL AIRPORT 82 68 82 72 83 / 60 90 60 30 60
STINSON MUNI AIRPORT 83 69 83 72 83 / 60 90 60 30 60
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SUNDAY EVENING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DE WITT...DIMMIT...EDWARDS...FAYETTE...FRIO...
GILLESPIE...GONZALES...GUADALUPE...HAYS...KARNES...KENDALL...KERR...
KINNEY...LAVACA...LEE...LLANO...MAVERICK...MEDINA...REAL...TRAVIS...
UVALDE...VAL VERDE...WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...OAKS
SYNOPTIC/GRIDS...HAMPSHIRE
Area Forecast Discussion
National Weather Service Spokane WA
451 AM PDT SAT MAY 23 2015
.SYNOPSIS...
The Memorial Day Weekend is expected to be warmer than average,
with afternoon temperatures in the 70s and 80s. Look for scattered
showers and thunderstorms this weekend into next week. Some
thunderstorms will be capable of producing heavy downpours and
frequent lightning.
&&
.DISCUSSION...
Saturday through Sunday night: A thermal trough of lower pressure
will shift slightly more into the basin today. This will set up
a weak northerly gradient over the northeast portion of the
region. The main impact that this gradient will have is to filter
in some drier air into out of Canada. There are some
discrepancies amongst the 00Z model guidance as far as how much
drier air will push down. The GFS and RAP (a.k.a. RUC) solutions
are a bit more aggressive with the drier air. The NAM/SREF are
more moist with dew point temperatures generally remaining in the
mid 30s to the lower 40s across the northern mountain valleys;
although, both of these solutions show a slight drying trend as
well. As would be expected, the GFS is much less unstable today
compared to Friday with dew point temperatures dropping into the
20s with drier push. The GFS would suggest that the Cascade crest
and the far southeast portion of the forecast area would see
convection today. The NAM, on the other hand, is a bit more
unstable, with convection possible over the Waterville Plateau and
across the northern mountains. I went with more of a compromise
between these two models. Best chances for convection today is
expected along the Cascade crest, over the Northeast Blue
Mountains over to the Central Panhandle Mtns. I also added a
slight chance of showers over the Waterville Plateau and over the
Okanogan Highlands.
Sunday looks to be a better day for more thunderstorm activity compared
to Saturday. Models are in good agreement that an upper level low
pressure system, currently over Graham Island off the BC mainland,
will drop down toward the region. This disturbance will tap into
some instability across the northwestern portion of the forecast
area. This will result in isolated to scattered thunderstorms
across the east slopes of the Cascade Mtns and progressively shift
across the northern half of the forecast area Monday afternoon
into Monday evening. Thunderstorms will be very wet with heavy
down pours likely; small hail and gusty outflow winds will also
be possible with the thunderstorms.
Temperatures will remain above normal through this weekend. Expect
high temperatures to remain in the upper 70s and 80s. /SVH
Memorial Day: An upper low is expected to descend into central
Washington Monday afternoon/evening bringing a good chance for
showers and thunderstorms to round out our holiday weekend.
Model agreement is good that the center of the 500mb low will be
in the vicinity of Omak by late afternoon placing northeast
Washington and north Idaho in a favorable region of upper level
diffluence under an advancing 500mb cold pool. The models suggest
that a dry slot surging into the Columbia Basin into southeast
Washington will suppress showers over the Palouse and Basin in the
afternoon. However, as the upper cold pool advances southward in
the evening, widely scattered showers may develop as far south as
Moses Lake, Pullman and Lewiston. Storm motion on Monday will be
more typical (east or northeast) compared to the westerly
propagating cells of the last couple of days. Weak shear and light
storm steering flow Monday afternoon suggest the potential for
locally heavy rain especially under cells over northern Washington
that may become terrain based. Burn scar flooding could be a
concern Monday afternoon and early evening.
Tuesday: Chances for showers and thunderstorms have been raised
for Tuesday especially over the Idaho Panhandle and
northeast/north central Washington. There is good model agreement
that the upper low that arrives Monday will move little by Tuesday
afternoon and evening. We may see better convective coverage
Tuesday than we do on Monday. As the upper low stalls, the dry
slot we anticipate Monday will probably be less pronounced on
Tuesday. Once again, storm steering flow will be very weak on
Tuesday setting the stage for locally heavy rain. If the models
place the 500mb low correctly on Tuesday over central Washington,
thunderstorms could be of particular concern for the 2014 burn
scars. This area could be in a prime spot for deep layer moisture
and surface instability in the wrap around region of the upper
low.
Wednesday through Friday: For the second half of the week chances
for shower/thunderstorm chances trend down as the medium range
models weaken the upper low and build a warm ridge over the Inland
Northwest Thursday and Friday. The end of the week has the
potential to be quite warm. The ECMWF and GFS suggest 850mb
temperatures near 20C which translates to mid 80s to low 90s.
Without a strong push of dry air, slight chances for showers and
thunderstorms remain in the forecast for the mountains into
Thursday and Friday. Afternoon and early evening showers primarily
driven by diurnal surface based instability. /GKoch
&&
.AVIATION...
12Z TAFS: Isolated showers will linger near KEAT and KMWH early
this morning. Diurnally driven showers and thunderstorms will be
possible this afternoon over the higher terrain along the east
slopes of the northern Cascades, over the Northeast Blue Mtns and
over the southern and central Panhandle Mtns. Any storms that
develop over the Central Panhandle Mtns may impact KPUW and KLWS
TAF locations as storm motion will be to the west and southwest;
however, confidence is low since thunderstorms are expected to
dissipate quickly as they move off of the higher terrain. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 81 53 79 55 71 51 / 10 10 10 30 50 50
Coeur d`Alene 80 53 80 54 70 48 / 10 10 10 30 50 50
Pullman 75 47 74 49 70 46 / 10 20 10 10 20 20
Lewiston 81 55 81 56 78 53 / 20 30 10 20 20 20
Colville 83 53 82 53 73 50 / 10 10 20 40 70 50
Sandpoint 80 48 79 51 70 47 / 10 0 10 30 60 50
Kellogg 77 49 78 50 70 47 / 20 10 10 20 60 50
Moses Lake 85 55 83 55 80 52 / 20 10 20 20 20 20
Wenatchee 85 59 82 57 78 55 / 20 10 20 20 20 20
Omak 87 53 83 52 76 51 / 10 10 40 40 50 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
1001 AM PDT SAT MAY 23 2015
.UPDATE...
FORECAST WAS UPDATED TO INCREASE COVERAGE OF SHOWERS AND
PRECIPITATION AMOUNTS FOR THIS EVENING ACROSS ALPINE, MONO AND
WESTERN MINERAL COUNTIES.
FOR THE REST OF TODAY THROUGH MIDNIGHT EXPECT GENERALLY 0.25 TO
0.75 INCHES OF RAIN OVER THE SIERRA WITH UP TO 2 INCHES OF WET
SNOW ON MOUNTAIN ROADS ABOVE 9,000 FEET. EXPECT MORE LOCALIZED
AMOUNTS UP TO 0.50 INCHES ACROSS WESTERN NV. THIS PRECIPITATION
SHOULD MOSTLY BE A BENEFICIAL RAIN BUT LOCATIONS RECEIVING HIGHER
AMOUNTS WILL SEE PONDING OF WATER ON ROADWAYS AND IN POOR
DRAINAGE AREAS. SNOW ABOVE 9,000 FEET MAY PRODUCE SLICK ROADS
OVER HIGH PASSES INCLUDING MOUNT ROSE SUMMIT AND SONORA AND TIOGA
PASSES.
THE NORTH-TO-SOUTH MOVING SHORTWAVE CROSSING THE AREA TODAY EXITS
INTO SOUTHERN CA/NV AFTER MIDNIGHT, BUT THERE IS POTENTIAL ACROSS
THE EASTERN SIERRA AND WESTERN NV FOR ISOLATED SHOWERS TO CONTINUE
OVERNIGHT. JCM
&&
.SYNOPSIS...
SCATTERED TO NUMEROUS SHOWERS AND A FEW THUNDERSTORMS ARE EXPECTED
TODAY FOR EASTERN CALIFORNIA AND WESTERN NEVADA AS LOW PRESSURE
MOVES OVER THE REGION. SHOWERS AND THUNDERSTORMS WILL DECREASE IN
COVERAGE SUNDAY AND MONDAY. TEMPERATURES BELOW AVERAGE TODAY WILL
WARM TO AROUND AVERAGE FOR SUNDAY AND MEMORIAL DAY MONDAY.
&&
.PREVIOUS DISCUSSION... /ISSUED 326 AM PDT SAT MAY 23 2015/
SYNOPSIS...
SCATTERED TO NUMEROUS SHOWERS AND A FEW THUNDERSTORMS ARE
EXPECTED TODAY FOR EASTERN CALIFORNIA AND WESTERN NEVADA AS LOW
PRESSURE MOVES OVER THE REGION. SHOWERS AND THUNDERSTORMS WILL
DECREASE IN COVERAGE SUNDAY AND MONDAY. TEMPERATURES BELOW AVERAGE
TODAY WILL WARM TO AROUND AVERAGE FOR SUNDAY AND MEMORIAL DAY
MONDAY.
SHORT TERM...
RAISED POP TODAY, ESPECIALLY FOR LATE MORNING AND THIS AFTERNOON FOR
THE EASTERN SIERRA AND FOR PORTIONS OF FAR WESTERN NEVADA. I ALSO
REDUCED OR REMOVED LATE NIGHT/MORNING SHOWER COVERAGE SUNDAY AND
MONDAY NIGHTS.
A FEW LIGHT SHOWERS AND AREAS OF DRIZZLE ARE ONGOING EARLY THIS
MORNING WITH HIGH HUMIDITIES AND WIDESPREAD STRATUS OR STRATOCUMULUS
DECKS PER SATELLITE AND OBSERVATIONS. THE NEXT WEATHER MAKER CAN
BE SEEN IN THE WATER VAPOR SATELLITE AS A CIRCULATION DROPPING
SOUTH ALONG THE OREGON COAST. THIS LOW WILL DROP INTO NORTHERN
CALIFORNIA THIS AFTERNOON AND EARLY EVENING. WITH THE MOIST AIRMASS,
SHOWERS ARE ALREADY BREAKING OUT IN THE SIERRA FOOTHILLS EAST OF
CHICO AND REDDING. THE 08Z HRRR INDICATES SHOWERS PUSHING OVER THE
CREST BETWEEN SUSANVILLE AND LAKE TAHOE BY MID MORNING. THIS
MAKES SENSE GIVEN THE SHOWERS ALREADY DEVELOPING AND THE INCOMING
UPPER LOW.
THIS AFTERNOON, WIDESPREAD SHOWERS ARE PROGGED TO PUSH OUT INTO
NEVADA AS THE UPPER LOW DROPS THROUGH THE SACRAMENTO VALLEY. WITH
THIS IN MIND, I HAVE RAISED POP TO LIKELY FOR THE RENO-TAHOE AREA
WITH A GOOD CHANCE FOR MANY OTHER AREAS NEAR AND SOUTH OF I-80.
THIS EVENING, THE GFS AND NAM SHOW THE BEST CHANCE FOR PRECIPITATION
SLIDING TO SOUTH OF HIGHWAY 50 AS A DEFORMATION AXIS TO THE EAST
OF THE LOW MOVES OVER THAT AREA. AS FAR AS THUNDERSTORMS THIS
AFTERNOON AND EVENING, THE CHANCES REMAIN LOW WITH THE CLOUDY,
MOIST CONDITIONS LIMITING CAPE. HOWEVER, A FEW THUNDERSTORMS ARE
EXPECTED IN THE MOIST AND AT LEAST SLIGHTLY UNSTABLE ATMOSPHERE.
TONIGHT, AND ESPECIALLY SUNDAY NIGHT, THERE WILL BE AN INCREASED
CHANCE FOR FOG AS CLOUD COVER DECREASES BEHIND TODAY`S LOW AND
MOISTURE REMAINS HIGH. HOWEVER, IT IS STILL QUITE UNCERTAIN AND WILL
DEPEND ON WHETHER THE LOWER LEVEL STRATUS DECK CAN BREAK UP. FOR
NOW, I JUST THREW IN PATCHY FOG AS A HEADS UP.
SUNDAY, THE COVERAGE OF SHOWERS LOOKS TO DECREASE SUBSTANTIALLY AS
SOME WARMING ALOFT/SLIGHT RIDGING MOVES IN BEHIND TODAY`S UPPER
LOW. HOWEVER, MORE INSOLATION AND RESIDUAL LOW LEVEL MOISTURE MAY
STILL ALLOW FOR A FEW AFTERNOON THUNDERSTORMS (MAINLY NEAR THE
SIERRA). ON MONDAY, A GLANCING BLOW FROM AN UPPER DISTURBANCE
MOVING THROUGH THE PACIFIC NORTHWEST WILL BRING INCREASED
AFTERNOON WESTERLY WINDS TO THE REGION. ELEVATED MOISTURE REMAINS
IN THE AREA SO CONVERGENCE AT THE LEADING EDGE OF THE WEST FLOW
ALONG WITH WARMER TEMPERATURES COULD BRING ISOLATED TO SCATTERED
AFTERNOON SHOWERS AND THUNDERSTORMS. SNYDER
LONG TERM...TUESDAY THROUGH FRIDAY...
LOW PRESSURE IN THE PACIFIC NORTHWEST WILL SLOWLY MOVE EAST
TUESDAY AND WEDNESDAY. LIGHT WEST FLOW ALOFT WILL CONTINUE, BUT
PLENTY OF RESIDUAL MOISTURE WILL REMAIN FOR A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS. TEMPERATURES WILL ALSO WARM TO NEAR
AVERAGE FOR LATE MAY.
FOR THURSDAY INTO FRIDAY, RIDGING WILL BUILD ALONG THE WEST COAST IN
THE WAKE OF THE LOW. TEMPERATURES WILL CONTINUE TO WARM WITH 80S
LIKELY IN WESTERN NV AND 70S IN THE SIERRA VALLEYS. IN ADDITION,
WARMING TEMPS ALOFT WITH THE RIDGE AND SLOW SURFACE DRYING SHOULD
RESULT IN DRY CONDITIONS BY FRIDAY. CONTINUED A THREAT OF ISOLATED
SHOWERS AND THUNDERSTORMS THURSDAY IN THE WAKE OF THE LOW, ALTHOUGH
KEPT THEM OUT OF THE TAHOE BASIN WITH LIGHT WEST WINDS AND
INCREASING STABILIZATION. WALLMANN
AVIATION...
SHOWERS CONTINUE THIS MORNING ACROSS MUCH OF NORTHEAST CALIFORNIA
AND NORTHWEST NEVADA. LCL MVFR CONDS CONTINUE IN -SHRA WITH CIGS
2-3000 FEET, BUT MOST 4-5000 FEET. EXPECT AND INCREASE IN SHOWERS
WITH ISOLD TSRA 15-21Z WITH AN INCOMING IMPULSE. GREATEST IMPACT
WILL BE AROUND RENO-TAHOE AREAS WITH MVFR CIGS TO 2-3000 FEET,
ALTHOUGH KMMH WILL ALSO BE THREATENED LATER. GS ALSO POSSIBLE IN
ANY TSRA.
AFTER 00Z, BEHIND THE IMPULSE, MORE STABILIZATION WILL OCCUR WITH
POSSIBLE CLEARING. AT THIS POINT, CONFIDENCE IS LOW ON HOW MUCH
CLEARING WILL OCCUR WITH ONLY ISOLD -SHRA POSSIBLE AFTER 03Z. IF
SKIES CLEAR ENOUGH, EXPECT FG TO FORM IN MANY VALLEYS FROM THE
RECENT RAIN. KTRK/MARTIS VALLEY MOST LIKELY TO BE AFFECTED, BUT
KRNO/KLOL/KTVL MAY ALSO SEE FG WITH VIS NEAR OR BLO 1/4SM.
POTENTIAL FG FOR KTRK 60 PCT WITH OTHER AREAS 20-30 PCT. WALLMANN
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
321 PM MDT SAT MAY 23 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 321 PM MDT SAT MAY 23 2015
AREAS OF THUNDERSTORMS HAVE BEEN MOVING OVER THE NORTHEAST
COLORADO PLAINS FOR THE PAST COUPLE HOURS. ANOTHER STORM IS
PRESENTLY MOVING OUT OF DOUGLAS COUNTY AND TRACKING NORTHEASTWARD.
STORMS HAVE BEEN MOVING FAST ENOUGH THAT RAINFALL AMOUNTS HAVE
GENERALLY BEEN HELD TO LESS THAN THREE-QUARTERS OF AN INCH. NO
FLOODING PROBLEMS HAVE BEEN REPORTED YET...BUT WITH SOME MORE
THUNDERSTORMS STILL EXPECTED...WILL LET THE FLASH FLOOD WATCH
CONTINUE. THE LINEAR SHEAR PROFILE IS OVERWHELMING THE BUOYANCY OF
THE AIRMASS...SO TORNADIC STORMS HAVE NOT DEVELOPED. WILL CLEAR
THE WESTERN EDGE OF THE TORNADO WATCH WITH ISSUANCE OF THE
AFTERNOON PACKAGE. REST OF WATCH WILL REMAIN IN PLACE SINCE
THUNDERSTORM ACTIVITY IS ONGOING.
AFTER THE EVENING CONVECTION DIES OFF...THE MOIST AIRMASS AND WEAK
FLOW WILL ALLOW STRATUS AND FOG TO RE-DEVELOP...SIMILAR TO WHAT WE
SAW THIS MORNING. FOR SUNDAY...MODELS SHOW THE UPPER LOW WILL
STILL BE OVER THE CENTRAL PART OF THE STATE. THIS MEANS ANOTHER
DAY OF UNSETTLED WEATHER. HAVE INCREASED THE CHANCES FOR
THUNDERSTORMS TO LIKELY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 321 PM MDT SAT MAY 23 2015
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE ACROSS
NORTH CENTRAL AND NORTHEASTERN COLORADO SUNDAY EVENING AS THE UPPER
LOW SLOWLY MEANDERS ACROSS THE CENTRAL ROCKIES. THE SHOWERS SHOULD
GRADUALLY DECREASE ACROSS THE PLAINS AFTER MIDNIGHT WITH A CHANCE OF
RAIN AND SNOW CONTINUING IN THE MOUNTAINS. ON MONDAY...THE UPPER LOW
WEAKENS AND BECOMES AN OPEN TROUGH AS IT MOVES INTO THE CENTRAL
PLAINS STATES. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
REDEVELOP ON THE PLAINS BY AFTERNOON AS MOISTURE ON THE BACK SIDE OF
THE TROUGH WRAPS INTO COLORADO FROM THE NORTH.
TEMPERATURES WILL WARM INTO THE LOWER 70S ON THE PLAINS ON TUESDAY
AS UPPER LEVEL HIGH PRESSURE BUILDS OVER THE ROCKY MOUNTAIN REGION.
THERE WILL STILL BE ENOUGH RESIDUAL MOISTURE AROUND...COMBINED WITH
DAYTIME HEATING TO PRODUCE ISOLATED TO SCATTERED AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS...MOST NUMEROUS IN THE MOUNTAINS.
THE UPPER FLOW BECOMES SOUTHWESTERLY ON WEDNESDAY AHEAD OF AN UPPER
TROUGH OVER THE WESTERN UNITED STATES. THE SOUTHWEST FLOW WILL
RESULT IN HIGH TEMPERATURES IN THE LOW 70S ON THE PLAINS WEDNESDAY
AND THURSDAY. SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS WILL ALSO BE POSSIBLE EACH DAY AS WEAK UPPER LEVEL
DISTURBANCES INTERACT WITH RESIDUAL MOISTURE AND DAYTIME HEATING.
COOLER UNSETTLED WEATHER COULD RETURN BY FRIDAY AFTERNOON AS UPSLOPE
FLOW DEVELOPS BEHIND THE PASSAGE OF A COLD FRONT. THE GFS SHOWS
QUITE A BIT OF QPF FROM THE CONTINENTAL DIVIDE EASTWARD INTO THE
URBAN CORRIDOR SATURDAY AFTERNOON AND EVENING...WHILE THE ECMWF
SHOWS VERY LITTLE. WARMER AND DRIER WEATHER IS EXPECTED BY SATURDAY
AS UPPER LEVEL HIGH PRESSURE BUILDS INTO COLORADO FROM THE WEST.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z SUNDAY LATE AFTERNOON)
ISSUED AT 321 PM MDT SAT MAY 23 2015
INITIAL WAVE OF THUNDERSTORMS HAS MOVED PAST THE AIRPORT...BUT NEW
CELLS ARE NOW MOVING OUT OF DOUGLAS COUNTY. THE NEXT THUNDERSTORM
HAS A BIT MORE OF A NORTHEAST TRACK...AND MAY MISS KDEN. WILL
STILL MENTION A FEW MORE HOURS OF THUNDER IN THE DENVER AREA
AIRPORTS. OVERNIGHT...A REPEAT OF THIS MORING IS POSSIBLE WITH FOG
AND STRATUS DEVELOPING. ANOTHER ROUND OF THUNDERSTORMS WILL BE
POSSIBLE SUNDAY AFTERNOON AS THE CENTER OF THE UPPER LOW WILL
REMAIN OVER THE FORECAST AREA. THE COOLEST PART OF THE WEATHER
DISTURBANCE WILL BE OVER DENVER...LEADING TO THE MOST UNSETTLED
WEATHER.
&&
.HYDROLOGY...
ISSUED AT 321 PM MDT SAT MAY 23 2015
AFTERNOON THUNDERSTORMS HAVE BEEN MOVING ALONG NICELY AND ONLY
PRODUCING ABOUT ONE-THIRD TO THREE-QUARTERS OF AN INCH OF
RAINFALL. THE HRRR MODEL SHOWS ANOTHER ROUND OF SHOWERS OVER THE
DENVER METRO AREA DURING THE EVENING...BUT WITH GENERALLY LIGHT
AMOUNTS. THE THREAT OF ADDITIONAL ROUNDS OF THUNDERSTORMS ON THE
NORTHEAST PLAINS CONTINUES...SO WILL LET THE FLASH FLOOD WATCH
CONTINUE.
THE CACHE LA POUDRE AND SOUTH PLATTE RIVERS REMAIN ABOVE FLOOD
STAGE ACROSS WELD COUNTY WITH MINOR IMPACTS. THESE FLOOD WARNINGS
WILL CONTINUE FOR ANOTHER COUPLE DAYS AS THE RIVERS WILL BE SLOW
TO RECEDE.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR COZ042-044>046-
048>051.
&&
$$
SHORT TERM...DANKERS
LONG TERM...JK
AVIATION...DANKERS
HYDROLOGY...DANKERS
AREA FORECAST DISCUSSION
NWS MIAMI FL
257 PM EDT SAT MAY 23 2015
.DISCUSSION...
SCATTERED SHOWERS AND STORMS ONGOING ACROSS THE INTERIOR AND
TOWARDS THE GULF COAST THIS AFTERNOON...WITH MAINLY QUIET
CONDITIONS FOR THE EAST COAST METRO AREAS. A WEAK SEA BREEZE HAS
DEVELOPED ALONG THE GULF COAST...AND MORE NUMEROUS ACTIVITY IS
EXPECTED THERE THIS AFTERNOON. THIS THINKING MATCHES UP WELL WITH
THE LATEST HRRR WHICH HAS NUMEROUS STORMS IN THE VICINITY OF
NAPLES LATE THIS AFTERNOON INTO THE EARLY EVENING. STORMS SHOULD
WIND DOWN AND MOVE INTO THE GULF OF MEXICO THIS EVENING...WITH
MAINLY QUIET CONDITIONS AFTER MIDNIGHT.
SUNDAY AND MEMORIAL DAY...STRONG SURFACE HIGH PRESSURE EXTENDING
FROM THE MID ATLANTIC EAST NORTHEAST INTO THE WESTERN ATLANTIC
WILL DOMINATE THROUGH THE REST OF THE MEMORIAL DAY WEEKEND. BREEZY
CONDITIONS WILL TAKE HOLD ACROSS THE REGION...BUT ESPECIALLY FOR
THE EAST COAST...WITH GUSTS UP TO 30 MPH POSSIBLE. LIFE-
THREATENING RIP CURRENTS ARE LIKELY AT THE ATLANTIC BEACHES.
STRONG MID/UPPER LEVEL RIDGE WILL SETTLE JUST TO THE EAST OF THE
FLORIDA PENINSULA...AND SUBSIDENCE OVER THE WESTERN ATLANTIC WILL
LEAD TO PROGRESSIVE UPSTREAM DRYING. SHALLOW LOW LEVEL MOISTURE
WILL REMAIN IN THE MODERATE TO FRESH EASTERLY FLOW OVER THE
ATLANTIC...SO ISOLATED TO SCATTERED COASTAL/STREAMER SHOWERS WILL
REMAIN POSSIBLE FOR THE EAST COAST...MAINLY IN THE OVERNIGHT AND
MORNING HOURS. PWATS WILL REMAIN 1.5-1.7 INCHES ACROSS THE
INTERIOR WEST AND GULF COAST THROUGH MEMORIAL DAY...AND HIRES
MODELS ARE HINTING AT A WEAK SEA BREEZE ALONG THE IMMEDIATE GULF
COAST DEVELOPING EACH AFTERNOON. WITH THE BRISK EASTERLY
FLOW...EXPECT SHOWERS/STORMS TO QUICKLY MOVE WEST INTO THE GULF OF
MEXICO WITHOUT TOO MUCH FANFARE.
TUESDAY...MODELS IN GOOD AGREEMENT THAT THE DRIEST LOW/MID LEVEL
AIR FROM THE ATLANTIC WILL ARRIVE ACROSS THE REGION ON
TUESDAY...WITH PWATS FALLING TO 1-1.4 INCHES AREAWIDE. THIS SHOULD
LEAD TO GENERALLY DRY CONDITIONS EAST AND A FEW SHOWERS FOR THE
GULF COAST. HIGH PRESSURE WILL REMAIN OVER THE WESTERN ATLANTIC
WITH A MODERATE EASTERLY FLOW...AND HIGH RISK OF RIP CURRENTS
CONTINUING.
WEDNESDAY THROUGH FRIDAY...SQUEEZE PLAY UNDERWAY AS LARGE CUTOFF
UPPER LOW DRIFTS WEST NORTH OF PUERTO RICO AND THE DOMINICAN
REPUBLIC...AND AN UPPER TROUGH TRIES TO PUSH INTO THE OHIO VALLEY.
THE UPPER RIDGE WILL BEGIN TO GET STRETCHED ON WEDNESDAY AND THEN
IT BREAKS DOWN AND GETS SHUNTED TO THE SOUTHWEST THROUGH THE END
OF THE WEEK. LARGE SCALE SUBSIDENCE WILL CONTINUE ACROSS SOUTH
FLORIDA TO THE WEST OF THE UPPER LOW...WITH MINIMAL RAIN CHANCES.
&&
.AVIATION...
AFTERNOON THUNDERSTORMS DEVELOPING ON-SCHEDULE ACROSS THE SOUTHERN
FLORIDA PENINSULA, MAINLY FROM LAKE OKEECHOBEE SOUTH AND WEST OVER
THE INTERIOR SECTIONS. EASTERLY FLOW IN LOW/MID LEVELS WILL FOCUS
THESE STORMS OVER THE INTERIOR TO THE GULF COAST THE REMAINDER OF
THIS AFTERNOON THROUGH ABOUT 00Z. KAPF THE ONLY TERMINAL EXPECTED
TO BE IMPACTED BY THESE STORMS WITH PERIODS OF MVFR AND
SHIFTING/GUSTY WINDS THROUGH AT LEAST 22Z. EAST COAST TERMINALS
SHOULD REMAIN DRY/VFR WITH CIRRUS CANOPY FROM INLAND STORMS
SPREADING EASTWARD. EAST WINDS CONTINUE TONIGHT WITH ISOLATED EAST
COAST SHOWERS POSSIBLE BUT NOT ENOUGH TO INCLUDE IN TAFS AT THIS
TIME. EAST FLOW STRENGTHENS ON SUNDAY WITH LIKELY HIGHER COVERAGE
OF EAST COAST SHOWERS AFTER 12Z. /MOLLEDA
&&
.MARINE...
THE GRADIENT INCREASES AS SURFACE HIGH PRESSURE MOVES OFF THE
EASTERN SEABOARD TODAY. WINDS BECOME INCREASINGLY EASTERLY AND
STRONGER SUNDAY, THEN SUSTAINED NEAR 20 KNOTS SUNDAY NIGHT AND
MONDAY, ELSE 15-20 KTS THROUGH THE REST OF THE FORECAST. MID AND
UPPER LEVEL HIGH PRESSURE WILL REMAIN ANCHORED ALONG THE EAST
COAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 78 86 78 87 / 10 20 30 30
FORT LAUDERDALE 78 87 79 87 / 10 30 30 30
MIAMI 78 88 78 90 / 10 30 30 30
NAPLES 73 92 73 92 / 30 60 20 60
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK FROM 8 PM EDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR FLZ168-172-173.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...84/AK
LONG TERM....84/AK
AVIATION...59/RM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
410 PM EDT SAT MAY 23 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 409 PM EDT SAT MAY 23 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER
UT...A RIDGE FROM THE SE CONUS INTO THE UPPER MS VALLEY AND A TROUGH
OVER NE CANADA RESULTING IN CONFLUENT WNW FLOW THROUGH THE NRN
LAKES. AT THE SFC...SW TO W WINDS PREVAILED OVER MOST OF UPPER MI
BUT WERE WEAK ENOUGH TO ALLOW A LAKE BREEZE TO MOVE INTO THE N
CNTRL. MIXING AOA 10K FT HAS HELPED DROP DEWPOINTS INTO THE LOW TO
MID 30S. WITH TEMPS ALSO INTO THE UPPER 70S...RH VALUES HAVE DROPPED
INTO THE 20-25 PERCENT RANGE. VIS LOOP INDICATEED SCT DIURNAL CU
ALONG WITH SOME MID/HIGH CLOUDS APPROACHING FROM THE MN/WI.
TONIGHT...WITH PERSISTENT SW WINDS AND INCREASING MID/HIGH
CLOUDS...MIN READINGS WILL REMAIN IN THE UPPER 40S TO MID 50S WITH
THE WARMEST CONDITIONS NEAR LAKE SUPERIOR WHERE DOWNSLOPE FLOW WILL
PREVAIL.
SUNDAY...MODELS SUGGEST THAT THE SFC AND MID LEVEL TROUGH WILL MOVE
INTO THE PLAINS WITH CONTINUED RIDING INTO THE NRN LAKES. HOWEVER SW
TO W MID LEVEL FLOW BRINGING INCREASED MOISTURE WITH 300K-310K
ISENTROPIC ASCENT TOWARD THE AREA WILL BRING A CHANCE OF LIGHT RAIN
TOWARD THE AREA BY LATE IN THE DAY. EXPECT THAT THE ONSET OF THE
PCPN MAY BE DELAYED BY CONTINUE DRY LOW LEVELS. TEMPS SHOULD AGAIN
CLIMB INTO THE MID 70S BUT WILL BE LIMITED BY INCREASING CLOUD
THICKNESS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 357 PM EDT SAT MAY 23 2015
UPPER AIR PATTERN TO START LONG TERM SHOWS LARGER TROUGH FM WESTERN
CANADA INTO THE PLAIN STATES. RIDGE ALOFT CENTERED OVER SE CONUS
EXTENDS RIDGE BACK OVER GREAT LAKES. SHORTWAVE ON LEADING EDGE OF
WESTERN CONUS TROUGH LIFTS TOWARD UPPER MISSISSIPPI RIVER VALLEY ON
SUNDAY NIGHT. SFC LOW AND ASSOCIATED WARM AIR AND MOISTURE ADVECTION
AHEAD OF THE WAVE...SEEN IN H85-H7 MOISTURE TRANSPORT FIELDS...
COMBINES WITH LARGER SCALE ASCENT IN RIGHT ENTRANCE REGION OF 130+
KT JET STREAK FM NORTHERN ONTARIO TO NEW ENGLAND TO BRING A PERIOD
OF SHOWERS ACROSS CWA LATER SUNDAY NIGHT THROUGH EARLY MONDAY AFTN.
SHOWERS SHOULD END FIRST ALONG THE WI BORDER ON MONDAY MORNING AND
THEN ALONG LK SUPERIOR IN THE AFTERNOON. ELEVATED INSTABILITY SHOWS
UP SOME WITH SI/S LOWERING TOWARD 0-1C BUT THAT ARRIVES AFTER MAIN
FORCING MOVES ACROSS. NOT EXPECTING MUCH FOR TSRA AT THIS POINT.
RAIN COULD FALL HEAVY AT TIMES GIVEN PWATS BY 12Z MONDAY AT KGRB
THAT WOULD BE IN THE HIGHEST 5 PCT COMPARED TO CLIMO FOR THE DATE.
ESE-E WINDS AHEAD OF THE LOW AND ASSOCIATED WARM FRONT/ADVECTION OF
HIGHER DWPNTS AND RAIN OVER ALL THE AREA POINTS TO FOG OVER THE GREAT
LAKES/ADJACENT SHORELINES AND ALSO OVER KEWEENAW PENINSULA AND HIGHER
TERRAIN OF CNTRL CWA BTWN KIMT AND MARQUETTE.
UNCERTAINTY IN POPS/WX LATE MONDAY AFTN INTO MONDAY EVENING BUT
GENERALLY EXPECT MAINLY DRY WEATHER DUE TO MID-LEVEL SUBSIDENCE AND
DRYING THAT MOVES OVERHEAD IN WAKE OF PRIMARY SHORTWAVE. LIKELY WILL
BE LINGERING LOW-LEVEL MOISTURE...THOUGH SSW BLYR WINDS DO NOT FAVOR
PERSISTENT LOW CLOUDS SINCE THAT PROVIDES MINIMAL TRAJECTORIES OFF
THE ADDITIONAL MOISTURE FM THE GREAT LAKES. GIVEN THE SSW WINDS ALSO
DIMINISHED FOG ON THE LAND AREAS...AT LEAST AWAY FM LK MICHIGAN AND
THE OPEN WATERS OF LK SUPERIOR. NAM INDICATES ENOUGH ADDITIONAL MID-
LEVEL MOSITURE MOVES IN BY EVENING TO COMBINE WITH INCREASING
INSTABILITY TO PRODUCE CONVECTION. SINCE NAM IS ONLY MODEL
INDICATING THIS AT PRESENT...WILL DISCOUNT THAT IDEA AND CONTINUE TO
DOWNPLAY POPS. TEMPS ON MONDAY DEPEND ON EXTENT OF CLEARING. WILL
NOT TAKE MUCH TO BOOST TEMPS WITH WARM TEMPS ALOFT IN WARM SECTOR OF
SFC LOW THAT WILL BE NW OF LK SUPERIOR BY 00Z TUE. MIXING TO H9
RESULTS IN MAX TEMPS INTO THE 70S...SO INCREASED MAX TEMPS SLIGHTLY.
LATER MONDAY NIGHT INTO TUESDAY...MAIN FRONT SWINGS ACROSS UPPER
GREAT LAKES AS SFC LOW TRACKS NORTH OF LK SUPERIOR. VARYING IDEAS ON
STRENGTH AND WESTWARD EXTENT OF SHORTWAVE LIFTING NORTHEAST ALONG THE
FRONT. GFS MOST AGRESSIVE WITH THAT IDEA WHERE ECMWF AND GEM ARE NOT
AS BULLISH. KEPT IT SIMPLE AND RETAINED LOW CHANCE POPS ALONG AND
AHEAD OF FRONT MOVING THROUGH. BASED ON SW H85 THETA-E ADVECTION
AHEAD OF THE FRONT AND AT LEAST A FEW HUNDRED J/KG OF ELEVATED
CAPE...ADDED SLIGHT CHANCE FOR THUNDER OVER EAST HALF OF CWA MONDAY
NIGHT INTO TUESDAY. BASED ON FORECAST SOUNDINGS...KEPT THE FOG GOING
OVER THE GREAT LAKES AND NEAR LK MICHIGAN AT LEAST FOR THE MORNING ON
TUESDAY. ENOUGH DRYING DEVELOPS LATER IN THE DAY TO DISSIPATE THE
FOG. TEMPS ON TUESDAY COOLEST OVER NW CWA AND NEAR LK MICHIGAN WITH
MORE PRONOUNCED ONSHORE FLOW. EVEN FOR THOSE AREAS THOUGH...TEMPS
WILL BE IN THE 60S. MAX TEMPS REACH MID 70S INLAND TOWARD WI BORDER.
REST OF EXTENDED INDICATES MAINLY DRY WEATHER FOR WEDNESDAY WITH
ANOTHER FRONT BRINGING SMALL CHANCES FOR RAIN THURSDAY INTO FRIDAY.
BASED ON LATEST ECMWF WHICH TRENDED TOWARD LAST COUPLE RUNS OF
GFS...APPEARS THAT NEXT WEEKEND WOULD BE DRIER AS MORE ACTIVE
FRONTAL BOUNDARY SETTLES OVER THE LOWER GREAT LAKES AND OHIO VALLEY.
KEPT LOW CHANCES THAT CONSENSUS GAVE ATTM...BUT IF THESE MODEL
TRENDS CONTINUE...LATER SHIFTS MAY BE ABLE TO REMOVE POPS FM NEXT
SATURDAY. OVERALL TEMPS THROUGH THE WEEK SHOULD BE AROUND NORMAL.
GIVEN THE LACK OF REAL COOLING AT H85 OTHER THAN WITH THE FRONT
MOVING THROUGH ON TUESDAY...COULD SEE TEMPS MOST DAYS TUESDAY
THROUGH THURSDAY PUSH SLIGHTLY ABOVE NORMAL IN THE MID-UPR 70S.
NIGHTTIME LOWS SHOULD STAY SAFELY ABOVE FREEZING...WITH MAINLY 40S
TO AROUND 50 DEGREES EXPECTED. COOLER TEMPS MOVE BACK IN NEXT
WEEKEND AS COOLER CANADIAN HIGH PRESSURE SETTLES OVER THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 137 PM EDT SAT MAY 23 2015
GUSTY WINDS AT SAW AND ESPECIALLY CMX WILL DIMINISH THIS AFTERNOON
AS THE PRES GRADENT WEAKENS BEHIND A DEPARTING WEAK TROUGH.
OTHERWISE...ALTHOUGH SOME MID/HIGH CLOUDS MAY MOVE IN TONIGHT INTO
SUNDAY MORNING...VFR CONDITIONS WILL PERSIST AS THE LOW LEVELS
REMAIN DRY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 357 PM EDT SAT MAY 23 2015
SW-W WINDS TO 25 KTS...EVEN GREATER THAN 30 KTS AT HIGHER LEVEL
OBSERVATION PLATFORMS...DIMINISHES THROUGH THE EVENING. WINDS THEN
REMAIN LESS THAN 20 KTS INTO SUNDAY NIGHT BEFORE BECOMING EAST TO
SOUTHEAST AND INCREASING TO 20-25 KTS MONDAY AND MONDAY NIGHT AS A
LOW PRESSURE SYSTEM LIFTS TO NORTHWEST LK SUPERIOR. STRONGEST WINDS
SHOULD OCCUR ON MONDAY OVER WESTERN LK SUPERIOR WHERE WINDS WILL
TURN NORTHEAST DUE TO FUNNELLING. FOG SHOULD DEVELOP LATE SUNDAY
NIGHT AND THIS WILL LINGER OVER MUCH OF LK SUPERIOR THROUGH TUESDAY
MORNING. FOG MAY BECOME DENSE AT TIMES. WINDS BEYOND MONDAY NIGHT
DIMINISH TO 20 KTS OR LESS AS PRESSURE GRADIENT WEAKENS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
553 PM CDT SAT MAY 23 2015
.UPDATE...FOR 00Z AVIATION DISCUSSION BELOW
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 431 PM CDT SAT MAY 23 2015
ISOLATED LIGHT SHOWERS AND SPRINKLES ARE POSSIBLE THROUGH THE
EVENING AND MOST OF THE NIGHT BUT LITTLE TO NO ACCUMULATION IS
EXPECTED OVER THE NEXT 6 TO 12 HOURS. SO...AS OF RIGHT NOW WERE
ARE IN A RELATIVELY LULL IN THE PRECIP AFTER AN AREA OF LIGHT
SHOWERS AFFECTED PORTIONS OF SOUTHERN AND CENTRAL MINNESOTA
THROUGHOUT THE DAY /WITH JUST ENOUGH TO WET THE GROUND IN SPOTS/.
AS OF THIS AFTERNOON...THE LOCAL AREA IS UNDER A WEAK SURFACE
RIDGE WITH LIGHT WINDS AND AN OVERCAST ALTOSTRATUS DECK. THERE IS
WEAK 850MB FLOW OUT OF THE SOUTH...BUT MN/WI IS LARGELY UNDER THE
INFLUENCE OF NEUTRAL TEMPERATURE ADVECTION AT THE MOMENT. THERE
IS...HOWEVER...WARMING BETWEEN 850-700MB ACROSS NE/IA LATE THIS
AFTERNOON. THIS IS LIKELY THE BEGINNING OF THE WARMER THETA-E
PLUME EXPECTED TO SPREAD NORTH OVERNIGHT AND BRING WIDESPREAD RAIN
TO THE FORECAST AREA ON SUNDAY. BETWEEN 12-14Z THE RAP BRINGS
BETWEEN 100-150 UNITS OF 925-850MB MOISTURE TRANSPORT INTO SOUTH
CENTRAL MN. THIS WILL PROBABLY BE THE LEADING EDGE OF WIDESPREAD
SHOWERS /PERHAPS WITH EMBEDDED WEAK THUNDERSTORMS/. THE THREAT FOR
VIGOROUS CONVECTION TOMORROW IS LOW...BECAUSE WE SIMPLY STRUGGLE
TO GET MUCH OF ANY ELEVATED INSTABILITY IN HERE TOMORROW. MID
LEVEL LAPSE RATES DO STEEPEN ACROSS IA/NE...BUT LOCALLY IT IS
PROBABLY JUST GOING TO AMOUNT TO A NICE PERSISTENT STRATIFORM RAIN
TOMORROW.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 431 PM CDT SAT MAY 23 2015
FINALLY BEGINNING TO GET A BIT MORE AGREEMENT WITH THE GUIDANCE ON
HOW THINGS WILL UNFOLD DURING THE LONG TERM. IT WILL START OFF ON A
WET NOTE SUNDAY NIGHT INTO MONDAY...IS LOOKING MAINLY DRY MONDAY
NIGHT THROUGH WEDNESDAY...WITH ANOTHER ROUND OF THUNDERSTORMS COMING
THROUGH THURSDAY...FOLLOWED BY A PRETTY STRONG COLD FRONT ON FRIDAY.
WE WILL START THINGS OFF WITH THE STRONGEST SHORTWAVE OF THE WEEKEND
WORKING NORTH ACROSS MN. THE ECMWF SHOWS THIS WITH A 50 KT LLJ COMING
UP TO THE EAST SIDE OF A SFC LOW THAT WILL BE TRACKING DUE NORTH TO
THE WEST OF I-35. THIS WILL BRING A HEAVY BAND OF RAIN THROUGH THE
AREA AS PWATS INCREASE TO OVER 1.5". THE ONLY MODEL FOR THIS EVENT
THAT LOOKS TO BE AVOIDED AT THIS POINT IS THE GFS...AS IT HAS
STARTED OFF TOO FAR EAST WITH PRECIPITATION TODAY AND CONTINUES TO
BE AN EASTERN OUTLIER INTO SUNDAY NIGHT. GFS ASIDE...REST OF THE
MODELS SHOW AN AREA WIDE PRECIP EVENT UNFOLDING FROM SUNDAY
AFTERNOON INTO MONDAY MORNING...WITH JUST ABOUT EVERYONE LOOKING TO
GET IN ON 0.75" TO 1.25" OF RAIN FROM LATER SUNDAY THROUGH MONDAY
MORNING. ONE THING THAT IS LACKING WITH THIS SYSTEM WHEN LOOKING AT
SOUNDINGS IS INSTABILITY...AS A RESULT...CAPPED THUNDER MENTION TO
JUST A SLIGHT CHANCE SUNDAY NIGHT THROUGH MONDAY MORNING AS THIS
LOOKS TO PRIMARILY BE A RAIN EVENT.
FOR MONDAY...IT IS BEGINNING TO LOOK DRIER...ESPECIALLY INTO MONDAY
NIGHT...WHERE POPS WERE CUT BACK SIGNIFICANTLY. DURING THE DAY...THE
WAVE FROM SUNDAY NIGHT WILL HAVE ABOUT A 1000MB SFC LOW MOVING INTO
NRN MN. IN THE WAKE OF THIS MORNING WAVE...A DRY SLOT AND SHORT WAVE
RIDGING WILL MOVE ACROSS THE MPX AREA...WHICH MAY PRETTY MUCH CUT
OFF THE PRECIP FOR MONDAY AFTERNOON. FOR MONDAY EVENING...WHEN THE
TRAILING COLD FRONT LOOKS TO BECOME ACTIVE...SAID FRONT WILL BE OFF
OVER WI...WITH MOST OF THAT PRECIPITATION OFF TO THE EAST WHILE THE
DEFORMATION PRECIP ON THE BACK SIDE OF THE SFC LOW LOOKS TO LARGELY
FALL TO THE N/NW OF THE MPX AREA. THIS WAS A PRETTY BIG CHANGE FROM
EARLIER MODEL RUNS AND THEREFORE THE PREVIOUS FORECAST...WHICH
PRETTY MUCH HAD AREA WIDE LIKELY POPS FOR MONDAY NIGHT...SO TRIED TO
CUT A MIDDLE GROUND BETWEEN THIS AND THE PREVIOUS FORECAST TO KEEP
FROM HAVING SUCH A DRASTIC CHANGE...WHICH BASICALLY MEANS WE CUT
POPS IN HALF ON MONDAY NIGHT...WITH JUST CHANCE POPS LEFT AT THIS
POINT.
FOR TUESDAY...WE WILL HAVE A BAGGY SFC PRESSURE PATTERN IN
PLACE...BUT SOME LINGERING INSTABILITY...WHICH MAY HELP GENERATE
SOME ISOLATED TO SCATTERED DIURNALLY DRIVEN ACTIVITY...SO HAVE
MAINTAINED SOME 20/30 POPS FOR THAT DAY. DID REMOVE ANY REMAINING
POPS THOUGH FOR WEDNESDAY WITH ALL GUIDANCE NOW DRY AS SHORTWAVE
RIDGING MOVES ACROSS THE AREA.
FOR THURSDAY...ALTHOUGH THERE ARE TIMING DIFFERENCES BETWEEN THE
GFS AND ECMWF WITH THE LATTER BEING THE FASTER OF THE TWO...BOTH
CONTINUE TO SHOW ANOTHER FRONT WORKING ACROSS THE AREA WITH A ROUND
OF THUNDERSTORMS OUT AHEAD OF THIS FEATURE. BOTH MODELS HAVE BEEN
SHOWING THIS FOR A FEW DAYS...SO HAVE INTRODUCED SOME LIKELY POPS
FOR THURSDAY AFTERNOON AND NIGHT.
TO END THE EXTENDED...BOTH THE GFS/ECMWF SHOW A RATHER POTENT COLD
FRONT DROPPING SOUTH ACROSS THE AREA FRIDAY INTO SATURDAY. LOOKING
AT THE HEMISPHERIC H5 FORECASTS...IT ACTUALLY MAKES PHYSICAL SENSE
TO SEE A STRONG FRONT COMING THROUGH AT THE END OF THE WEEK AS BOTH
THE GFS/ECMWF SHOW THE UPPER AIR PATTERN TAKING ON A DECIDEDLY -NAO/-
AO PATTERN AS HIGH HEIGHTS MOVE OVER THE NORTH POLE...WITH
ANOMALOUSLY DEEP UPPER LOWS MOVING SOUTH OUT OF THE ARCTIC. THIS
PATTERN...EVEN IN EARLY SUMMER WOULD ALLOW COLD AIR TO GET DISLODGED
FROM THE ARCTIC AND THAT IS WHAT BOTH THE ECMWF/GFS SHOW FOR NEXT
WEEKEND AS A CONTINENTAL POLAR AIRMASS WORKS DOWN IN THE FORM OF A
1030+ MB HIGH WITH DEWPS BACK IN THE 20S/30S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 554 PM CDT SAT MAY 23 2015
SPOTTY SPRINKLES/VERY LIGHT RAIN SHOWERS WILL PESTER THE TAF AREA
THIS EVENING...BUT HAVE NO IMPACT ON CIGS/VSBYS. THE MAIN BATCH OF
RAIN IS EXPECTED TO CROSS THE MN/IA BORDER AROUND DAYBREAK
SUNDAY...THEN EXPAND NORTH AND EAST ACROSS THE AREA ON SUNDAY
MORNING/AFTERNOON. EXPECT CIGS/VSBYS TO DEGRADE TO MVFR WITHIN 3-4
HOURS OF PRECIP ONSET. HAVE NOT INCLUDED A THUNDER MENTION BECAUSE
INSTABILITY PROGS INDICATE A VERY MINIMAL THREAT. AFTER SQUIRRELY
WINDS TO START THE PERIOD /ASSOCIATED WITH BOUNDARIES IN THE
AREA/...SHOULD SEE WINDS LATCH ON TO A MORE EASTERLY DIRECTIONAL
COMPONENT FOR TONIGHT...AND THEN INCREASING ABOVE 10KTS ON SUNDAY
MORNING.
KMSP...
THE NORTHERLY WIND SHOULD GRADUALLY SHIFT TO EASTERLY FOR
TONIGHT...THEN INCREASE OUT OF THE EAST/SOUTHEAST FOR
SUNDAY...WITH GUSTS TO 18KTS. COULD SEE A FEW SHOWERS IN THE VCTY
OF THE FIELD DURING THE MORNING...BUT THE BULK OF THE SHOWERS
/WITH MVFR CIGS-VSBYS/ SHOULD ARRIVE AROUND/AFTER 17Z.
/OUTLOOK FOR KMSP/
MON...VFR. SCT SHRA/TSRA WITH MVFR OR LOWER CONDITIONS. WINDS S
10 KTS.
TUE...VFR. CHC SHRA/-TSRA. WINDS SW 10 KTS.
WED...VFR. WINDS SW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...CLF
LONG TERM...MPG
AVIATION...LS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
433 PM CDT SAT MAY 23 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 431 PM CDT SAT MAY 23 2015
ISOLATED LIGHT SHOWERS AND SPRINKLES ARE POSSIBLE THROUGH THE
EVENING AND MOST OF THE NIGHT BUT LITTLE TO NO ACCUMULATION IS
EXPECTED OVER THE NEXT 6 TO 12 HOURS. SO...AS OF RIGHT NOW WERE
ARE IN A RELATIVELY LULL IN THE PRECIP AFTER AN AREA OF LIGHT
SHOWERS AFFECTED PORTIONS OF SOUTHERN AND CENTRAL MINNESOTA
THROUGHOUT THE DAY /WITH JUST ENOUGH TO WET THE GROUND IN SPOTS/.
AS OF THIS AFTERNOON...THE LOCAL AREA IS UNDER A WEAK SURFACE
RIDGE WITH LIGHT WINDS AND AN OVERCAST ALTOSTRATUS DECK. THERE IS
WEAK 850MB FLOW OUT OF THE SOUTH...BUT MN/WI IS LARGELY UNDER THE
INFLUENCE OF NEUTRAL TEMPERATURE ADVECTION AT THE MOMENT. THERE
IS...HOWEVER...WARMING BETWEEN 850-700MB ACROSS NE/IA LATE THIS
AFTERNOON. THIS IS LIKELY THE BEGINNING OF THE WARMER THETA-E
PLUME EXPECTED TO SPREAD NORTH OVERNIGHT AND BRING WIDESPREAD RAIN
TO THE FORECAST AREA ON SUNDAY. BETWEEN 12-14Z THE RAP BRINGS
BETWEEN 100-150 UNITS OF 925-850MB MOISTURE TRANSPORT INTO SOUTH
CENTRAL MN. THIS WILL PROBABLY BE THE LEADING EDGE OF WIDESPREAD
SHOWERS /PERHAPS WITH EMBEDDED WEAK THUNDERSTORMS/. THE THREAT FOR
VIGOROUS CONVECTION TOMORROW IS LOW...BECAUSE WE SIMPLY STRUGGLE
TO GET MUCH OF ANY ELEVATED INSTABILITY IN HERE TOMORROW. MID
LEVEL LAPSE RATES DO STEEPEN ACROSS IA/NE...BUT LOCALLY IT IS
PROBABLY JUST GOING TO AMOUNT TO A NICE PERSISTENT STRATIFORM RAIN
TOMORROW.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 431 PM CDT SAT MAY 23 2015
FINALLY BEGINNING TO GET A BIT MORE AGREEMENT WITH THE GUIDANCE ON
HOW THINGS WILL UNFOLD DURING THE LONG TERM. IT WILL START OFF ON A
WET NOTE SUNDAY NIGHT INTO MONDAY...IS LOOKING MAINLY DRY MONDAY
NIGHT THROUGH WEDNESDAY...WITH ANOTHER ROUND OF THUNDERSTORMS COMING
THROUGH THURSDAY...FOLLOWED BY A PRETTY STRONG COLD FRONT ON FRIDAY.
WE WILL START THINGS OFF WITH THE STRONGEST SHORTWAVE OF THE WEEKEND
WORKING NORTH ACROSS MN. THE ECMWF SHOWS THIS WITH A 50 KT LLJ COMING
UP TO THE EAST SIDE OF A SFC LOW THAT WILL BE TRACKING DUE NORTH TO
THE WEST OF I-35. THIS WILL BRING A HEAVY BAND OF RAIN THROUGH THE
AREA AS PWATS INCREASE TO OVER 1.5". THE ONLY MODEL FOR THIS EVENT
THAT LOOKS TO BE AVOIDED AT THIS POINT IS THE GFS...AS IT HAS
STARTED OFF TOO FAR EAST WITH PRECIPITATION TODAY AND CONTINUES TO
BE AN EASTERN OUTLIER INTO SUNDAY NIGHT. GFS ASIDE...REST OF THE
MODELS SHOW AN AREA WIDE PRECIP EVENT UNFOLDING FROM SUNDAY
AFTERNOON INTO MONDAY MORNING...WITH JUST ABOUT EVERYONE LOOKING TO
GET IN ON 0.75" TO 1.25" OF RAIN FROM LATER SUNDAY THROUGH MONDAY
MORNING. ONE THING THAT IS LACKING WITH THIS SYSTEM WHEN LOOKING AT
SOUNDINGS IS INSTABILITY...AS A RESULT...CAPPED THUNDER MENTION TO
JUST A SLIGHT CHANCE SUNDAY NIGHT THROUGH MONDAY MORNING AS THIS
LOOKS TO PRIMARILY BE A RAIN EVENT.
FOR MONDAY...IT IS BEGINNING TO LOOK DRIER...ESPECIALLY INTO MONDAY
NIGHT...WHERE POPS WERE CUT BACK SIGNIFICANTLY. DURING THE DAY...THE
WAVE FROM SUNDAY NIGHT WILL HAVE ABOUT A 1000MB SFC LOW MOVING INTO
NRN MN. IN THE WAKE OF THIS MORNING WAVE...A DRY SLOT AND SHORT WAVE
RIDGING WILL MOVE ACROSS THE MPX AREA...WHICH MAY PRETTY MUCH CUT
OFF THE PRECIP FOR MONDAY AFTERNOON. FOR MONDAY EVENING...WHEN THE
TRAILING COLD FRONT LOOKS TO BECOME ACTIVE...SAID FRONT WILL BE OFF
OVER WI...WITH MOST OF THAT PRECIPITATION OFF TO THE EAST WHILE THE
DEFORMATION PRECIP ON THE BACK SIDE OF THE SFC LOW LOOKS TO LARGELY
FALL TO THE N/NW OF THE MPX AREA. THIS WAS A PRETTY BIG CHANGE FROM
EARLIER MODEL RUNS AND THEREFORE THE PREVIOUS FORECAST...WHICH
PRETTY MUCH HAD AREA WIDE LIKELY POPS FOR MONDAY NIGHT...SO TRIED TO
CUT A MIDDLE GROUND BETWEEN THIS AND THE PREVIOUS FORECAST TO KEEP
FROM HAVING SUCH A DRASTIC CHANGE...WHICH BASICALLY MEANS WE CUT
POPS IN HALF ON MONDAY NIGHT...WITH JUST CHANCE POPS LEFT AT THIS
POINT.
FOR TUESDAY...WE WILL HAVE A BAGGY SFC PRESSURE PATTERN IN
PLACE...BUT SOME LINGERING INSTABILITY...WHICH MAY HELP GENERATE
SOME ISOLATED TO SCATTERED DIURNALLY DRIVEN ACTIVITY...SO HAVE
MAINTAINED SOME 20/30 POPS FOR THAT DAY. DID REMOVE ANY REMAINING
POPS THOUGH FOR WEDNESDAY WITH ALL GUIDANCE NOW DRY AS SHORTWAVE
RIDGING MOVES ACROSS THE AREA.
FOR THURSDAY...ALTHOUGH THERE ARE TIMING DIFFERENCES BETWEEN THE
GFS AND ECMWF WITH THE LATTER BEING THE FASTER OF THE TWO...BOTH
CONTINUE TO SHOW ANOTHER FRONT WORKING ACROSS THE AREA WITH A ROUND
OF THUNDERSTORMS OUT AHEAD OF THIS FEATURE. BOTH MODELS HAVE BEEN
SHOWING THIS FOR A FEW DAYS...SO HAVE INTRODUCED SOME LIKELY POPS
FOR THURSDAY AFTERNOON AND NIGHT.
TO END THE EXTENDED...BOTH THE GFS/ECMWF SHOW A RATHER POTENT COLD
FRONT DROPPING SOUTH ACROSS THE AREA FRIDAY INTO SATURDAY. LOOKING
AT THE HEMISPHERIC H5 FORECASTS...IT ACTUALLY MAKES PHYSICAL SENSE
TO SEE A STRONG FRONT COMING THROUGH AT THE END OF THE WEEK AS BOTH
THE GFS/ECMWF SHOW THE UPPER AIR PATTERN TAKING ON A DECIDEDLY -NAO/-
AO PATTERN AS HIGH HEIGHTS MOVE OVER THE NORTH POLE...WITH
ANOMALOUSLY DEEP UPPER LOWS MOVING SOUTH OUT OF THE ARCTIC. THIS
PATTERN...EVEN IN EARLY SUMMER WOULD ALLOW COLD AIR TO GET DISLODGED
FROM THE ARCTIC AND THAT IS WHAT BOTH THE ECMWF/GFS SHOW FOR NEXT
WEEKEND AS A CONTINENTAL POLAR AIRMASS WORKS DOWN IN THE FORM OF A
1030+ MB HIGH WITH DEWPS BACK IN THE 20S/30S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 100 PM CDT SAT MAY 23 2015
EVEN WITH THESE LIGHT SHOWERS AND SPRINKLES MOVING THROUGH THE
AREA THIS AFTERNOON...LITTLE TO IMPACTS TO CEILINGS AND VISIBILITY
SHOULD BE EXPECTED. VFR SHOULD PERSIST INTO AT LEAST THE FIRST
HALF OF THE NIGHT. THE WINDS HAVE BEEN TRICKY TODAY...VARIABLE AT
MANY LOCATIONS. IN GENERAL...WE EXPECT A LIGHT E-SE FLOW TO
DEVELOP AT MOST SITES THIS AFTERNOON/EVENING. MANY SITES ARE
ALREADY THERE...BUT EASTERN MN AND WESTERN WI HAS BEEN SLOW TO
MAKE THE CHANGE OVER. TOMORROW LOOKS RAINY AND WE COULD START TO
SEE MORE SITES PICK UP MVRF CONDITIONS BY TOMORROW LATE MORNING
INTO THE AFTERNOON. THUNDER IS POSSIBLE TOMORROW...BUT WILL NOT
BE WIDESPREAD.
KMSP...
THE WIND DIRECTION HAS BEEN THE CHALLENGE OF THE TAF TODAY. WINDS
ARE TRICKY IN SITUATIONS LIKE THIS WHERE THE AIRPORTS SHOW
DIVERGING WINDS AT THE SURFACE. IN THESE CASES...THE WINDS ARE
OFTEN LIGHT AND HAVE LOTS OF VARIABILITY IN DIRECTION. THE LAST 30
MINUTES HAVE SHOWN MORE OF A TENDENCY OF A NORTHEAST DIRECTION.
SO OUR BEST EDUCATED GUESS AT THIS POINT IS FOR A N-NE-E-SE
TRANSITION TO THE WINDS OVER THE NEXT 6-12 HOURS AND IN GENERAL
THE SPEED SHOULD BE UNDER 7-8KTS.
/OUTLOOK FOR KMSP/
MON...VFR. SCT SHRA/TSRA WITH MVFR OR LOWER CONDITIONS. WINDS S
10 KTS.
TUE...VFR. CHC SHRA/-TSRA. WINDS SW 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...CLF
LONG TERM...MPG
AVIATION...CLF
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
306 PM CDT SAT MAY 23 2015
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 250 PM CDT SAT MAY 23 2015
TONIGHT
REGIONAL 88D MOSAIC SHOWING AREA OF TSRA OVER KS QUICKLY APPROACHING
THE SRN CWA. THE LAST SEVERAL RUNS OF THE HRRR SEEM TO HAVE A GOOD
HANDLE TIMING THE PCPN WITH THE LATEST INDICATING THE LEADING EDGE
OF THE ACTIVITY PUSHING INTO THE SRN CWA SOMETIME BTWN 22Z-24Z LATE
THIS AFTN. RAP13 SUGGESTING RATHER STRONG 305K UPGLIDE/INFLUX OF
MOISTURE SHOULD AID IN MAINTAINING THE PCPN ACTIVITY THEN THRU THE
MAJORITY OF THE OVERNIGHT HOURS. INSTABILITY WILL BE MINIMAL AT
BEST...THUS EXPECT ANY THUNDER TO BE ISOLATED IN NATURE.
AT THIS POINT...VERY GOOD AGREEMENT SEEN BTWN THE HRRR/RAP13/AWR-NMM
WITH HIGHEST QPF FOUND OVER THE SRN CWA WHERE MAX OMEGA WILL BE
REALIZED OVERNIGHT. GENERAL CONSENSUS AMONGST THE SHORT TERM MODELS
GIVE AMOUNTS GENERALLY AROUND 1.5" BY 12Z SUN SOUTH OF THE I-80
CORRIDOR. MEANWHILE OVER THE REST OF THE CWA...AMOUNTS ANYWHERE FROM
AROUND A TENTH OF AN INCH UP TO HALF AN INCH BY SUN MORNING LOOK
POSSIBLE. IN ADDITION...CHANCE OF FLASH FLOODING TO THE SOUTH LOOKS
RELATIVELY SMALL PER LATEST FLASH FLOOD GUIDANCE.
SUNDAY THROUGH TUESDAY
SHOWERS MAY BE ONGOING ALONG/EAST OF THE MISSOURI RIVER SUNDAY
MORNING...MAY WANE BY LATE MORNING...BUT THEN COULD REDEVELOP BY
SUNDAY AFTERNOON ALONG/SOUTH OF I80 AS THE NEXT UPPER LEVEL
IMPULSE BEGINS TO MOVE INTO REGION. INSTABILITY WILL ALSO RETURN
WITH MUCAPES INCREASING TO 1000-1500 J/KG DURING THE AFTERNOON. A
DRY SLOT COULD ALSO AFFECT PORTIONS OF CENTRAL/EASTERN NEBRASKA
WHICH COULD MAKE THUNDERSTORM ACTIVITY PRETTY SPARSE. A SECONDARY
WARM FRONT LIFTING NORTH THROUGH THE AREA SUNDAY NIGHT COULD BRING
A FEW STORMS...ESPECIALLY SUNDAY EVENING...THEN LIFTING NORTH
AFTER MIDNIGHT.
COULD SEE PRECIP WANE AGAIN MONDAY MORNING AS WEAK UPPER LEVEL
RIDGING MOVES INTO THE AREA. WITH WARM FRONT WELL NORTH OF THE
REGION...TEMPS SHOULD BE MUCH WARMER BACK INTO THE MID TO UPPER
70S. THIS WILL RESULT IN VERY UNSTABLE CONDITIONS DEVELOPING FOR
MONDAY AFTERNOON AND EVENING. THIS WILL BE WITHIN THE AREA WELL
AHEAD OF A WEAK COLD FRONT THAT SHOULD MOVE ACROSS THE REGION
MONDAY NIGHT. BEST THREAT FOR SEVERE STORMS AND POTENTIAL HEAVY
RAIN APPEARS TO BE MONDAY EVENING ALONG/SOUTH OF I80.
COLD FRONT IS STILL MOVING THROUGH THE REGION TUESDAY THUS STILL
HAVE A CHANCE OF PRECIP ALONG SOUTH OF THE FRONT...WITH PRECIP
CHANCES WINDING DOWN TUESDAY NIGHT.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 250 PM CDT SAT MAY 23 2015
WILL CONTINUE A DRY FORECAST WEDNESDAY AS WE SHOULD IN BETWEEN
SYSTEMS. NEXT TROUGH COMES OFF THE ROCKIES WEDNESDAY NIGHT INTO
THURSDAY BRINGING THE NEXT CHANCE FOR THUNDERSTORMS. A COUPLE MORE
IMPULSES MOVE ACROSS THE PLAINS THURSDAY NIGHT THROUGH SATURDAY
BRINGING ADDITIONAL HIGH CHANCE TO LIKELY POPS TO THE REGION.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1218 PM CDT SAT MAY 23 2015
REGIONAL RADAR SHOWING TSRA/IFR CONDITIONS CURRENTLY LIFTING THRU
KS AND INTO S-CNTRL NEB. EXPECT THE PCPN ACTIVITY TO REACH ERN NEB
LATE THIS AFTN WITH IFR CONDITIONS SETTLING IN AT ALL TAF SITES.
AT THIS POINT...APPEARS LIKELY THAT COMBINATION OF IFR/LIFR
CONDITIONS WILL PREVAIL THRU ABOUT 12Z SUN MORNING...THEN
POSSIBLE IMPROVEMENT TO MVFR TWD 18Z SUN.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...DEE/DEWALD
LONG TERM...DEWALD
AVIATION...DEE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1252 PM CDT SAT MAY 23 2015
.UPDATE...
ISSUED AT 940 AM CDT SAT MAY 23 2015
STILL LOOKING AT SOME POSSIBLE SPRINKLES ACROSS A SMALL PORTION OF
WEST CENTRAL MINNESOTA LATE MORNING/EARLY AFTERNOON.
OTHERWISE...ANTICIPATE CLOUD COVER INCREASING FROM SOUTH TO NORTH
TODAY...BUT REMAINING SOUTH OF HWY 2. RAP 850MB-700MB RELATIVE
HUMIDITY APPEARS TO HAVE A GOOD HANDLE ON THIS CLOUD SHIELD AND
USED FOR TIMING PURPOSES. MAX TEMPS WILL BE WELL INTO THE 70S
(POSSIBLY 80F) NORTH OF HWY 2 WITH FULL SOLAR...WITH COOLER VALUES
NEAR 70F WITH CLOUDS. DID RAISE MAX TEMPS A BIT NEAR THE
INTERNATIONAL BORDER.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 327 AM CDT SAT MAY 23 2015
ISSUES WILL BE HOW FAR AND WHEN WILL THE PRECIP SPREAD NORTH THE
NEXT FEW DAYS. LARGER UPPER TROUGH OVER UTAH/N ARIZONA THIS
MORNING. THIS WILL SLOWLY MOVE EAST THE NEXT FEW DAYS..AS MOISTURE
CONTINUES TO MOVE NORTH. THE NORTHERN EDGE OF HIGH LEVEL CLOUD
COVER WILL SPREAD OVER THE AREA TODAY WITH SOME MID CLOUDS IN THE
SRN FCST AREA THIS AFTN. OF INTEREST IS A SMALL AREA OF SHOWERS IN
THE SIOUX FALLS AREA. HRRR AND A FEW OTHER SHORT RANGE MODELS DO
BRING A FEW SPITS OF PRECIP NORTHEAST INTO WCNTRL MN (ALEX-ST
CLOUD AREA) LATE MORNING INTO EARLY AFTN. TO BLEND WITH WFO MPX I
DID INSERT A FEW SPRINKLES IN OTTER TAIL AND WADENA COUNTIES LATE
MORNING INTO MID AFTN. BASED ON MOISTURE MOVING NORTH ANY SHOWERS
WILL NOT REACH THE SD/ND BORDER AREA TIL LATE THIS AFTN AND
TRIMMED POPS ACCORDINGLY FOR TODAY. TONIGHT WILL SEE A SHOWER RICK
IN THE SOUTH BUT STUBBORN HIGH PRESSURE TO THE NORTH ALONG THE
CANADIAN BORDER WILL REMAIN IN PLACE SLOWING DOWN ANY NORTHWARD
ADVANCEMENT OF MOISTURE.
SUNDAY WILL SEE DEEPER MOISTURE START TO MOVE INTO SE ND AND THEN
SPREAD NORTH DURING THE DAY. THUS HIGHER POPS...MOSTLY SOUTHERN
FCST AREA. GFS REMAINS A BIT FASTER THAN ECMWF/GEM WHICH KEEP
DVL-GFK AREA DRY THRU SUN EVE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT MAY 23 2015
RAIN CHANCES SPREAD NORTH SUN NIGHT WITH HIGH RAIN CHANCES MONDAY
AS UPPER TROUGH AND SFC LOW MOVE FROM SOUTHERN SD INTO CNTRL/SRN
MN. HIGH PRESSURE DOES REMAIN OVER SOUTHERN MANITOBA AND SOME
MODELS WANT TO KEEP FAR NW FCST AREA DRY EVEN MONDAY. AT THIS TIME
WENT WITH SUPERBLEND OF MODELS AND IDEA OF CATEGORICAL POPS FOR
SHOWERS MONDAY SE 2/3 OF THE FCST AREA. SOME WEAK
INSTABILITY...BUT VERY WEAK...SO DID KEEP SLIGHT CHANCE OF THUNDER
SUN NIGHT THRU MON IN THE GRIDS. PRECIP BEGINS TO MOVE EAST MON
NIGHT. AS FOR HOW MUCH RAINFALL....MOST AREAS IN THE ONE HALF TO
THREE QUARTERS INCH RANGE GFK SOUTH AND EAST AND LESS NORTHWEST.
FOR TUESDAY THROUGH FRIDAY...
NOT A LOT OF AGREEMENT AMONG MODELS ALTHOUGH THEY DO ALL SHOW THE
POTENTIAL FOR THUNDERSTORM ACTIVITY. UPPER FEATURES BECOME OUT OF
PHASE WHEN COMPARING ECMWF AND GFS...UNCHANGED FROM YESTERDAY`S
SOLUTION. ECMWF HAS LONGER WAVES WITH MORE OF A SOUTHWEST FLOW MID
WEEK WHILE GFS HANGS ON TO A DIGGING SHORTWAVE NORTH OF THE BORDER
WITH MORE OF A ZONAL FLOW OVER THE NORTHERN PLAINS. AMOUNT OF
MOISTURE RETURN WILL BE KEY TO COVERAGE AND INTENSITY OF STORMS.
LATEST EXTENDED SUPERBLEND SOLUTION CONTINUES WITH POPS COVERING
MOST OF THE FORECAST AREA MOST OF THE TIME...ONLY ADJUSTMENT WAS TO
SMOOTH OUT MINUTE AREAS OF PCPN/NO PCPN WITHIN THE FGF CWA.
TEMPERATURES WILL BE NEAR NORMAL VALUES WITH DAYTIME HIGHS MOSTLY IN
THE 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1252 PM CDT SAT MAY 23 2015
CONTINUE WITH VFR CIGS/VSBY THROUGH THE FORECAST PERIOD. MID LEVEL
CIGS WILL GRADUALLY SPREAD NORTH INTO THE SOUTHERN FA REACHING FAR
EARLY THIS EVENING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...RIDDLE
LONG TERM...WJB/RIDDLE
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1225 PM CDT SAT MAY 23 2015
.UPDATE...
ISSUED AT 1225 PM CDT SAT MAY 23 2015
CLOUD COVER MOVING NORTH FROM SOUTH DAKOTA AND FORECAST TEMPERATURES
SOUTHWEST AND SOUTH CENTRAL MAINLY ON TRACK. STILL SUNNY NORTHWEST
AND NORTH CENTRAL HAVE RAISED MAX TEMPERATURES THERE TO THE LOW TO
MID 70S. THIS AFFECTS MINIMUM RELATIVE HUMIDITY VALUES...WITH DEWPOINTS
LOWERING NORTH WITH MIXING...AND MIN RH VALUES NORTH NOW EXPECTED
IN THE 20 TO 30 PERCENT RANGE.
RADAR RETURNS AT BOWMAN ARE BECOMING STRONGER IN NORTHWESTERN SOUTH
DAKOTA AND SOUTHEASTERN MONTANA. THUS CHANCES OF RAIN BEGINNING IN
THE SOUTHWEST EARLY THIS AFTERNOON APPEARS ON TRACK. NO CHANGES IN
TIMING EXPECTATIONS FOR RAIN...WITH AFTERNOON CHANCES FAR SOUTHWEST
AND FAR SOUTH CENTRAL AND MOVING NORTHWARD GRADUALLY TOWARD EVENING
TO AROUND I-94 IN THE SOUTHWEST BUT NOT REACHING I-94 IN THE JAMES
VALLEY UNTIL LATER THIS EVENING.
UPDATE ISSUED AT 925 AM CDT SAT MAY 23 2015
SATELLITE LOOPS AND SHORT TERM MODELS INDICATE LARGE CLOUD MASS
OVER SOUTH DAKOTA MOVING NORTHWARD ACROSS NORTH DAKOTA THROUGH THE
DAY. LATEST HRRR AND NAM MODELS INDICATE LOW CLOUDS MAKING THEIR
WAY NORTHWARD TOWARDS THE I-94 CORRIDOR THROUGH THE DAY. LOW
CLOUDS IN HETTINGER HAVE SCATTERED OUT...BUT EXPECT THAT WITH TIME
THEY WILL COVER THE FAR SOUTHERN TIER OF COUNTIES FOR MUCH OF THE
AFTERNOON.
REGARDING RAIN CHANCES...WILL KEEP THE MENTION OF RAIN OUT FOR THE
MORNING HOURS AS PER THE EARLY MORNING FORECAST PACKAGE. SHORT
TERM MODELS - INCLUDING THE NAM - INDICATE AFTERNOON SHOWERS
LIFTING NORTHWARD OVER FAR SOUTHWESTERN AND FAR SOUTH CENTRAL
NORTH DAKOTA. A LOOK AT THE BOWMAN RADAR INDICATES LIGHT RADAR
RETURNS IN THE FAR SOUTHWEST PART OF NORTH DAKOTA...AND SUSPECT
RADAR IS PICKING UP ON MID CLOUDS AND/OR VIRGA IN THE AREA.
LIFTING GOING ON IN THE LOW/MID ATMOSPHERE BUT NOT ENOUGH YET TO
YIELD PRECIPITATION REACHING THE GROUND. THE GFS REMAINS VERY
AGGRESSIVE AND IS OVER- FORECASTING THE PRECIPITATION. MINOR
CHANGES TO AFTERNOON RAIN CHANCES...BUT BASICALLY CHANCES ARE FOR
SCATTERED SHOWERS TO BE MAINLY SOUTH OF I-94...PERHAPS A BIT
BETTER FOR SCATTERED SHOWERS TOWARDS THE MEDORA/BEACH AREA DURING
THE AFTERNOON.
BETTER LIFTING AND STRONGER FORCING BEGINS THIS EVENING.
RAISED TEMPERATURES A TAD IN THE FAR NORTH BASED ON CURRENT
TRENDS. OTHERWISE FORECAST ON TRACK.
UPDATE ISSUED AT 620 AM CDT SAT MAY 23 2015
EARLY MORNING WATER VAPOR IMAGERY SHOWS A WAVE MOVING NORTH ACROSS
SOUTH DAKOTA. THIS IS EXPECTED TO BE THE MAIN DRIVER OF THE RAIN
CHANCES TODAY. CURRENT RAP / HRRR SUGGEST ANY RAIN CHANCES SHOULD
HOLD OFF FOR SEVERAL MORE HOURS. THE CURRENT FORECAST BRINGS IN
POPS ACROSS THE SOUTH BY EARLY AFTERNOON...AND WILL MAINTAIN THAT
TIMING FOR THIS UPDATE. MAINLY BLENDED CURRENT CONDITIONS INTO
THE FORECAST WITH ONLY MINOR ADJUSTMENTS MADE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT SAT MAY 23 2015
THE MAIN FOCUS FOR THE SHORT TERM IS TIMING OF RAIN
TODAY/TONIGHT.
THE LATEST TRENDS IN THE 00 UTC MODEL SUITE INDICATE AN EVEN
FURTHER DELAY IN PRECIPITATION ONSET. THE EARLIER NAM AND GEM RUNS
KEPT RAIN OUT OF THE AREA UNTIL TONIGHT. THE GFS AND ECMWF HAVE
FOLLOWED SUIT WITH THEIR LATEST RUNS. FURTHERMORE...THE OO UTC
RUNS OF THE WRF FURTHER INDICATE A DELAY UNTIL THIS AFTERNOON.
THEREFORE...REMOVED ALL MENTION OF PRECIPITATION UNTIL THIS
AFTERNOON. IT APPEARS SOME SCATTERED RAIN SHOWERS ARE POSSIBLE
THIS AFTERNOON...WITH THE BULK OF THE RAIN EXPECTED LATER TONIGHT
INTO TOMORROW AS THE MAIN LOW PRESSURE CENTER EJECTS ACROSS THE
PLAINS. ALSO PUSHED BACK THE MENTION OF THUNDERSTORMS AS THE
LATEST GUIDANCE SUGGESTS INSTABILITY WILL BE CONFINED TO SOUTH
DAKOTA TODAY.
WITH INCREASING CLOUDS AND POSSIBLE RAIN...SOUTHERN NORTH DAKOTA
SHOULD BE THE COOL SPOT TODAY...WITH TEMPERATURES IN THE
60S...WHILE NORTHERN NORTH DAKOTA SEES A LITTLE MORE SUN AND
TEMPERATURES IN THE 70S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 343 AM CDT SAT MAY 23 2015
THE MAIN FORECAST CHALLENGE REMAINS THE RAIN / THUNDERSTORM
CHANCES SUNDAY AND MONDAY. MODEL DIFFERENCES KEEP CONFIDENCE IN
THE OVERALL DETAILS FOR SUNDAY AND MONDAY SOMEWHAT LOW. THE GFS
REMAINS THE MORE ROBUST MODEL IN REGARDS TO QPF ACROSS THE
FORECAST AREA...WHILE THE NAM IS ON THE LOW END OF VALUES. THE
ECMWF IS MORE IN THE MIDDLE...SO WILL CONTINUE TO GO WITH A BLEND
OF SOLUTIONS. THIS KEEPS THE HIGHER RAIN CHANCES AND QPF ACROSS
THE SOUTHERN PART OF NORTH DAKOTA. INSTABILITY IS STILL NOT VERY
HIGH ON SUNDAY...SO HAVE KEPT ANY THUNDERSTORM CHANCES ISOLATED.
AS STATED EARLIER...MODEL SOLUTIONS STILL VARY ON MONDAY...AND
THIS ALSO INFLUENCES THE AMOUNT OF INSTABILITY THEY PRODUCE. WILL
BUMP UP THE THUNDERSTORM PROBABILITIES ON MONDAY WITH MORE
INSTABILITY SHOWN BY THE GFS...BUT WILL KEEP THINGS IN THE CHANCE
CATEGORY.
IN REGARDS TO RAINFALL AMOUNTS...WE ARE STILL SHOWING THE HIGHEST
TOTALS IN SOUTHWEST NORTH DAKOTA WHERE AMOUNTS OF 1.00 - 1.25
INCHES ARE FORECAST THROUGH TUESDAY MORNING. THE LOWEST AMOUNTS
REMAIN IN THE NORTH WHERE WE HAVE 0.25 - 0.50 INCH THROUGH THAT
SAME TIME PERIOD.
THE UNSETTLED PATTERN CONTINUES MUCH OF NEXT WEEK WITH PERIODIC
WAVES MOVING THROUGH THE REGION. HAVE STAYED CLOSE TO A BLENDED
MODEL SOLUTION WHICH KEEPS SMALL POPS MOST OF NEXT WEEK.
INSTABILITY OVERALL IS NOT THAT IMPRESSIVE...SO WILL KEEP ANY
THUNDERSTORM CHANCES ISOLATED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1225 PM CDT SAT MAY 23 2015
VFR CONDITIONS ARE EXPECTED AT KMOT THROUGH THE TAF PERIOD...WITH
VFR AT KISN UNTIL AROUND 06Z WHEN MVFR CIGS FORECAST.
VFR CONDITIONS WILL LIKELY DETERIORATE TO MFVR CIGS AT KDIK/KBIS
AROUND 00Z WITH VCSH...AND MVFR CIGS AND VSBYS WITH RAIN BY AROUND
04Z-06Z. KJMS TO BECOME MVFR LATER TONIGHT WITH RAIN.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...AJ
LONG TERM...CK
AVIATION...JV
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
226 PM CDT SAT MAY 23 2015
.SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...
AN ACTIVE AND COMPLEX FORECAST IS SHAPING UP OVER SOUTH CENTRAL
TEXAS THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK WITH BOTH
SEVERE WEATHER AND FLASH FLOODING POSSIBLE. FLASH FLOOD WATCH IS
IN EFFECT THROUGH 7 PM ON SUNDAY.
IN ADDITION TO THE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
THAT IS ONGOING CURRENTLY ACROSS THE TEXAS HILL COUNTRY AND I-35
CORRIDOR CONVECTION HAS BEGUN ACROSS NORTHERN MEXICO AND THE BIG
BEND REGION. THIS IS THE START OF A LARGE LINEAR MCS THAT ALL OF
THE MESOSCALE MODELS SHOW MOVING ACROSS THE STATE THIS EVENING
INTO EARLY TOMORROW MORNING. THE UPPER LEVEL LOW PRESSURE THAT HAS
BEEN SITTING OVER THE WESTERN UNITED STATES WILL MOVE TO THE EAST
AND NORTHEAST THIS AFTERNOON AND OVERNIGHT PROVIDING THE LIFT FOR
THIS MCS. THERE IS PLENTY OF MOISTURE IN PLACE WITH DEWPOINTS IN
THE LOW 70S AND PRECIPITABLE WATER VALUES BETWEEN 1.75 AND 2
INCHES. THERE IS ALSO PLENTY OF INSTABILITY OVER THE AREA WITH
THE MORNING DRT AND CRP SOUNDINGS BOTH HAVING 2000 - 3000 J/KG OF
CAPE. A GOOD AMOUNT OF LOW LEVEL AND BULK SHEAR IS ALSO EVIDENT
ACCORDING TO THE MODELS. THIS MEANS THAT ALL OF THE INGREDIENTS
ARE IN PLACE FOR BOTH HEAVY RAINFALL AND SEVERE WEATHER THIS
AFTERNOON THROUGH THE OVERNIGHT HOURS INTO TOMORROW. WILL
BREAKDOWN THE THREATS AND THE TIME PERIODS IN THE REST OF THE
SHORT TERM AFD.
FOR TONIGHT...AS ALREADY DISCUSSED...THE MESOSCALE MODELS DEVELOP
A COMPLEX OF STORMS THAT WILL SWEEP ACROSS THE STATE OVERNIGHT
TONIGHT. TIMING FOR THIS CONTINUES TO GET EARLIER. THE NSSL WRF
AND ARM BOTH HAVE THE LINE APPROACHING THE I-35 CORRIDOR BY THE
LATE AFTERNOON. THE TEXAS TECH WRF AND HRRR AND NMM ALL SAY THAT
THE LINE WILL BE MOVING THROUGH THE HILL COUNTRY AND APPROACHING
THE I-35 CORRIDOR BY 9PM AND SLOWLY PUSHING EAST THROUGH THE EARLY
MORNING HOURS. BASED ON CURRENT SATELLITE TRENDS THE EARLIER
TIMING IS BEGINNING TO LOOK MORE LIKELY. MODELS ARE STILL HOLDING
ONTO 1-3 INCH RAINFALL TOTALS WITH THIS INITIAL WAVE OF
CONVECTION. THIS...ON TOP OF ADDITIONAL RAINS THAT HAVE ALREADY
FALLEN TODAY...AND THE FACT THAT SOILS ARE SATURATED WILL LEAD TO
THE THREAT OF BOTH RIVER FLOODING AND FLASH FLOODING. THE SEVERE
WEATHER THREAT WILL ALSO BE PRESENT. WHILE CONVECTION GROUPING
TOGETHER LIKE THIS TYPICAL MEANS THE THREAT FOR SEVERE WEATHER IS
A LITTLE BIT LESS...CONVECTIVE PARAMETERS ARE VERY FAVORABLE. THE
MAIN CONCERNS WILL BE FIRST DAMAGING THUNDERSTORM WINDS WITHIN
BOWING SECTIONS OF THE LINE. THE HRRR ACTUAL SUPPORTS THIS WITH
SEVERAL BOWING SECTIONS BEING SHOWN IN THE MODEL REFLECTIVITY.
THERE IS ALSO SUFFICIENT SURFACE WIND SHEAR AND HELICITY VALUES
TO RESULT IN AN ISOLATED TORNADO THREAT AS WINDS PROFILES TURN
WITH HEIGHT.
DURING THE OVERNIGHT HOURS IT IS IMPERATIVE THAT THOSE OUT AND
ABOUT FOR THE HOLIDAY WEEKEND...ESPECIALLY THOSE ON LOCAL RIVERS
AND LAKES...MONITOR THE WEATHER AND BE READY TO ACT SHOULD A
WARNING BE ISSUED FOR THEIR AREA. HAVE MULTIPLE WAYS TO RECEIVE
WEATHER INFORMATION...HAVE A PLAN TO SEEK SHELTER OR GET TO SAFETY
SHOULD SEVERE WEATHER OR FLOODING OCCUR...AND ALWAYS REMEMBER TO
TURN AROUND...DONT DROWN.
AS WE GET INTO EARLY SUNDAY MORNING THE LINE WILL CONTINUE TO
PUSH ACROSS THE I-35 CORRIDOR INTO OUR EASTERN COUNTIES WITH
CONTINUED RISK FOR FLASH FLOODING AND SEVERE WEATHER. MODELS NOW
SHOW THE LINE MOVING OUT OF OUR CWA BY 09Z TO 12Z (4 TO 7 AM).
BEHIND THE LINE THE ATMOSPHERE WILL BE SOME WHAT WORKED OVER FROM
THE NIGHT OF STORMS. ALTHOUGH MODEL SOUNDINGS SHOW OVER 3000 J/KG
OF CAPE...SIGNIFICANT INSTABILITY...DURING THE AFTERNOON HOURS
ALONG THE I-35 CORRIDOR. THE SAME SOUNDINGS SHOW SIGNIFICANT LOW
AND UPPER LEVEL DRYING OF THE ATMOSPHERE. THIS SHOULD LIMIT SHOWER
AND THUNDERSTORM ACTIVITY SUNDAY AFTERNOON INTO THE OVERNIGHT
HOURS SUNDAYS. MESOSCALE MODELS LIKE THE ARM/NMM/NSSL WRF DO SHOW
SOME ISOLATED ACTIVITY SUNDAY AFTERNOON BUT COVERAGE SHOULD BE
LIMITED.
TO SUMMARIZE THE NEXT 24 HOURS...1 TO 4 INCHES OF RAINFALL ARE
EXPECTED WITH A LINE OF SHOWERS AND STORMS THAT WILL SLOWLY MOVE
ACROSS THE AREA THIS EVENING INTO THE OVERNIGHT HOURS. FLASH FLOOD
WATCH IN EFFECT. THE LINE SHOULD BE PUSHING OUT OF OUR AREA
EARLY SUNDAY MORNING. THE THREAT FOR SEVERE THUNDERSTORM WINDS
ALONG WITH AN ISOLATED TORNADO EXIST WITH THE LINE. BY TOMORROW
AFTERNOON ONLY AN ISOLATED SHOWER OR THUNDERSTORM IS EXPECTED
THROUGH THE AFTERNOON AND OVERNIGHT HOURS. EVERYONE SHOULD BE
WEATHER AWARE FOR THIS WEEKEND...ESPECIALLY THOSE OUT AND ABOUT ON
AREA RIVERS AND LAKES.
&&
.LONG TERM (MONDAY THROUGH SATURDAY)...
THE BREAK FROM THE SHOWER AND THUNDERSTORM ACTIVITY WILL BE SHORT
LIVED AS ANOTHER UPPER LEVEL DISTURBANCE APPROACHES ON MONDAY.
THIS DISTURBANCE...CURRENTLY SEEN ON WATER VAPOR ACROSS NORTHERN
CALIFORNIA WILL ROTATE AROUND THE BASE OF THE LARGER UPPER LEVEL
TROUGH AND GIVE SOUTH CENTRAL TEXAS ANOTHER SHOT OF RAIN AND
STORMS. MODELS INDICATE THAT THE BEST TIMING FOR ANOTHER WAVE OF
PRECIPITATION WILL BE FROM AROUND LUNCH TIME THROUGH THE
AFTERNOON. MODEL QPF (FROM THE GFS AND ECMWF) FOR THIS TIME PERIOD
SUGGEST ANOTHER 1 TO 2 INCHES POSSIBLE. PRECIPITABLE WATER VALUES
REMAIN OVER 1.5 INCHES AS WELL. LATER SHIFTS WOULD POSSIBLE NEED
TO CONSIDER EXTENDING THE FLASH FLOOD WATCH INTO MONDAY AS
CONFIDENCE INCREASES. THE CHANCE FOR SEVERE WEATHER WILL ALSO
RETURN ON MONDAY. SPC HAS THE AREA CURRENTLY BLANKETED IN A DAY 3
SLIGHT RISK. MODEL SOUNDINGS AGAIN SHOW CAPE AND SHEAR VALUES
SUPPORTIVE OF HAIL...DAMAGING WINDS AND ISOLATED TORNADOES. STORM
MODE AND COVERAGE OF STORMS WILL DETERMINE THE OVERALL THREAT OF
TORNADOES AS CHANCES ARE BETTER WITH ISOLATED SUPERCELLS RATHER
THAN WIDESPREAD CONVECTION OR MCS STORM MODES. WILL HAVE TO
MONITOR THE THREAT FOR SEVERE WEATHER MONDAY CLOSELY. STRESSING
AGAIN...ANYONE WITH OUTDOOR PLANS FOR THE HOLIDAY NEEDS TO MAKE
SURE THEY ARE WEATHER AWARE AND HAVE A PLAN TO SEEK SHELTER SHOULD
SEVERE WEATHER DEVELOP.
THE UPPER LEVEL FLOW FOR TUESDAY IS MORE ZONAL WITH SOME SLIGHT
RIDGING FOR WEDNESDAY. THIS WILL BRING ANOTHER REDUCTION IN POP
CHANCES FOR MID-WEEK. BY THE END OF THE WEEK ANOTHER LARGE UPPER
LEVEL TROUGH SETS UP ACROSS THE WEST RETURNING THE AREA TO A
SIMILAR PATTERN THAT WE HAVE BEEN IN FOR THE LAST FEW WEEKS WITH A
LARGE UPPER TROUGH SENDING A SERIES OF DISTURBANCES ACROSS THE
AREA. RAIN CHANCES WILL BE ON THE RISE AGAIN LATE NEXT WEEK INTO
NEXT WEEKEND.
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 69 81 70 81 69 / 90 70 30 70 60
AUSTIN BERGSTROM INTL AIRPORT 69 82 69 81 68 / 90 70 30 70 60
NEW BRAUNFELS MUNI AIRPORT 68 83 69 81 70 / 90 70 40 70 60
BURNET MUNI AIRPORT 67 81 69 80 67 / 90 70 30 70 40
DEL RIO INTL AIRPORT 68 90 71 89 69 / 60 30 20 50 20
GEORGETOWN MUNI AIRPORT 69 80 69 80 68 / 90 70 30 70 50
HONDO MUNI AIRPORT 68 85 70 83 69 / 90 40 30 70 40
SAN MARCOS MUNI AIRPORT 69 82 69 81 69 / 90 70 40 70 60
LA GRANGE - FAYETTE REGIONAL 71 82 71 82 71 / 80 80 60 60 60
SAN ANTONIO INTL AIRPORT 68 84 71 82 71 / 90 60 40 70 50
STINSON MUNI AIRPORT 69 84 71 83 71 / 90 60 40 70 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SUNDAY EVENING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DE WITT...DIMMIT...EDWARDS...FAYETTE...FRIO...
GILLESPIE...GONZALES...GUADALUPE...HAYS...KARNES...KENDALL...KERR...
KINNEY...LAVACA...LEE...LLANO...MAVERICK...MEDINA...REAL...TRAVIS...
UVALDE...VAL VERDE...WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...10
SYNOPTIC/GRIDS...TREADWAY
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1240 PM CDT SAT MAY 23 2015
.AVIATION.../18Z TAFS/
CONCERN FOR THIS FORECAST PERIOD WILL BE THE CONVECTION THAT
DEVELOPS THIS AFTERNOON...BUT MORE IMPORTANTLY THE SIGNIFICANT
CONVECTION THAT IS EXPECTED OVERNIGHT. SEVERAL OF THE HI RES
MODELS ARE REALLY DEVELOPING THE CONVECTION ALONG THE RIO GRANDE
IN THE 20Z-22Z TIME PERIOD AND MOVING THE SYSTEM EASTWARD TO THE
I-35 CORRIDOR BY 02Z-04Z AND THEN EAST OF THE TERMINALS BY 12Z
SUNDAY. HAVE USED THE SLIGHTLY FASTER TRENDS FOR THIS FORECAST
PERIOD. FOR THIS AFTERNOON 18Z-23Z SHOULD SEE MVFR/IFR CONDITIONS
WITH SCATTERED CONVECTION. WILL SEE THE MORE WIDESPREAD CONVECTION
DEVELOPING BY 20Z-22Z ACROSS THE RIO GRANDE AND THEN ADVANCING
EASTWARD THROUGH 09Z. LINGERING SHRA SHOULD MOVE OUT BY 12Z-13Z.
CIGS WILL FALL TO IFR WITH CONVECTION OVERNIGHT AND THEN IMPROVE
TO VFR BY 17Z. S/SE WINDS 10-15 KNOTS THROUGH 01Z THEN E/SE 5-10
KNOTS OVERNIGHT AND THROUGH 15Z. AFTER 15Z SUNDAY SOUTHERLY WINDS
AT 10-15 KNOTS WITH SOME GUSTS TO 20 KNOTS POSSIBLE.
&&
.PREV DISCUSSION... /ISSUED 953 AM CDT SAT MAY 23 2015/
UPDATE...
BIGGEST CHANGE TO THE FORECAST WAS TO UP RAIN CHANCES ACROSS THE
RIO GRANDE PLAINS BY 10 PERCENT THIS AFTERNOON. ALSO ADJUSTED
HIGHS FOR TODAY ACROSS THE HILL COUNTRY UP A DEGREE GIVEN CURRENT
OBSERVATIONS. OTHERWISE ONLY MINOR CHANGES MADE AND TRENDED ALL
HOURLY GRIDS BASED ON MORNING SURFACE OBSERVATIONS.
DISCUSSION...
ALL OF THE MORNING MESOSCALE/HIGH-RES MODELS CONTINUE TO TREND
EARLIER FOR THE LINE OF SHOWERS AND THUNDERSTORMS THIS EVENING.
MOST HAVE IT DEVELOPING OVER THE DEL RIO AREA AROUND 5 PM AND
GETTING INTO THE I-35 CORRIDOR BETWEEN 9 AND MIDNIGHT. HEAVY RAINS
AND SEVERE WEATHER ARE STILL LOOKING LIKELY WITH THIS SYSTEM...AND
WILL LOOK IN DEPTH INTO THAT IN THE AFTERNOON PACKAGE AND
DISCUSSION. FOR THE REST OF TODAY SCATTERED SHOWERS AND
THUNDERSTORMS SHOULD INCREASE IN COVERAGE THIS AFTERNOON AHEAD OF
THE LINE.
WILL CONTINUE TO STRESS THAT ANYONE ON LOCAL RIVERS AND LAKES THIS
HOLIDAY WEEKEND...TODAY THROUGH MONDAY...NEED TO PAY VERY CLOSE
ATTENTION TO THE WEATHER AND ANY WARNINGS THAT ARE ISSUED. HAVE
MULTIPLE WAYS TO RECEIVE WEATHER INFORMATION...HAVE A PLAN TO
SEEK SHELTER OR GET TO SAFETY SHOULD SEVERE WEATHER OR FLOODING
OCCUR...AND ALWAYS REMEMBER TURN AROUND...DONT DROWN.
PREV DISCUSSION... /ISSUED 653 AM CDT SAT MAY 23 2015/
AVIATION... /12Z TAF UPDATE/
ACTIVE CONVECTION IS IMPACTING AUS AT THE TIME OF TAF ISSUANCE.
THE SCATTERED SHOWERS AND THUNDERSTORMS LOOK TO BE PULLING NORTH
OF THE SAT/SSF VCNTYS FOR A FEW HOURS AND COULD LIFT NORTH OF THE
AUS AREA IN THE NEXT HOUR OR TWO AS WELL. DEEP TROPICAL MOISTURE
AND ANOTHER RIPPLE OF ENERGY NEAR DRT COULD BEGIN TO IMPACT THE
I-35 SITES AGAIN BY 15Z. CONVECTION SHOULD BE SCATTERED SO TIMING
IS IN LOW CONFIDENCE FOR TODAY. CONFIDENCE INCREASES FOR THE
PREVAILING THUNDER PERIOD...ALTHOUGH THE TIME WINDOW MAY BE ABLE
TO COMPRESS ONCE THE MUCH ANTICIPATED STORM COMPLEX BEGINS TO TAKE
SHAPE. AFTER THE COMPLEX IS SPECULATED TO PASS EAST OF I-35 TOWARD
DAYBREAK...WILL CONTINUE PREVAILING SHOWERS...WITH SOME POSSIBLE
FURTHER IMPROVEMENTS TO FOLLOW DURING THE DAYLIGHT HOURS SUNDAY.
WILL KEEP CONDITIONS FAIRLY PESSIMISTIC IN CASE THE SYSTEM SLOWS
DOWN.
PREV DISCUSSION... /ISSUED 314 AM CDT SAT MAY 23 2015/
SHORT TERM (TODAY THROUGH SUNDAY)...
MODERATE TO HEAVY RAINFALL IS GETTING AN EARLY START WITH
CONVECTION INCREASING WEST OF HIGHWAY 83. THIS IS ALL ASSOCIATED
WITH INCREASING LIFT AHEAD OF THE MAIN UPPER LOW WHICH IS STILL
OVER UTAH/ARIZONA PER 00Z UPPER AIR ANALYSIS AND LATEST WATER
VAPOR IMAGERY. RAINFALL RATES WITH THIS ACTIVITY ARE GENERALLY AT
1-2 INCHES PER HOUR AND WE HAVE ALREADY ISSUED ONE FLOOD ADVISORY.
THE HRRR IS ZEROING IN ON THIS AREA WHERE RAIN IS CURRENTLY
INCREASING AND IS COMING UP WITH SOME HIGH TOTALS THIS MORNING.
BECAUSE OF THIS EARLY THREAT OF HEAVY RAINFALL...WILL GO AHEAD
AND START THE FLASH FLOOD WATCH NOW. THIS WILL BE A BIT TOO EARLY
FOR THE EASTERN ZONES...BUT WANT TO AVOID CONFUSION WITH A
SEGMENTED PRODUCT. HIGH-RES MODEL GUIDANCE CONTINUES TO SHOW THE
WESTERN CWA AS THE FAVORED AREA FOR CONVECTION LATER THIS MORNING
BEFORE SPREADING ACROSS THE AREA THIS AFTERNOON. RAIN LOOKS LIKELY
FOR TODAY WITH 60/70 POPS ACROSS THE CWA. INDIVIDUAL CELLS COULD
CONTAIN HEAVY RAINFALL AND SOME TRAINING OF CELLS IS ALSO
POSSIBLE.
THE MAIN FORCING WITH THIS INITIAL WAVE OF LIFT ASSOCIATED WITH
THE UPPER LOW WILL BEGIN TO ARRIVE TO THE WESTERN ZONES LATE THIS
AFTERNOON AND EVENING. CONFIDENCE IS HIGH THAT A LINE OF SHOWERS
AND THUNDERSTORMS WILL DEVELOP WITH THIS LIFT AND STRETCH ACROSS A
LARGE PORTION OF TEXAS. THERE ARE SOME DISCREPANCIES WITH THE
GUIDANCE ON THE EXACT TIMING OF THIS WITH MOST MODELS SOMEWHERE
BETWEEN THE 21Z TO 03Z TIME FRAME...WITH SOME OF THE HIGH-RES
GUIDANCE BEING THE EARLIEST. THIS LINE IS EXPECTED TO SLOWLY MARCH
THROUGH THE CWA OVERNIGHT AND IS EXPECTED TO AVERAGE A QUICK 1-3
INCHES OF RAIN AS IT MOVES ACROSS. OVERNIGHT RAIN ON TOP OF ANY
RAINFALL THAT OCCURS TODAY WILL NOT BE ABLE TO SOAK INTO THE
GROUND...AS SOILS REMAIN QUITE SATURATED FROM A VERY WET SPRING.
MOST OF THE RAIN WILL RUNOFF INTO CREEKS...STREAMS AND RIVERS AND
FLOODING IS ONCE AGAIN LIKELY.
ALTHOUGH FLOODING RAINS IS OF THE HIGHEST CONCERN ON THIS HOLIDAY
WEEKEND...THERE IS THE THREAT OF SEVERE WEATHER AS WELL. SEVERE
PARAMETERS ARE FAVORABLE FOR SEVERE STORMS...BUT AM CONCERNED WITH
THE HIGHER COVERAGE OF STORMS AND THE EFFECT THAT COULD HAVE BY
CLUTTERING UP THE NEAR-STORM ENVIRONMENT. HOWEVER...CANT RULE OUT
BOWING SEGMENTS WITHIN THE MAIN LINE THAT COULD PRODUCE SOME
SEVERE WINDS. ALSO...LOW-LEVEL WINDS WILL INCREASE AND SOME
TURNING IN THE PROFILE WILL POSE AN ISOLATED TORNADO THREAT WITH
ANY STRONGER LINE SEGMENTS AS WELL AS THE MAIN LINE MOVES THROUGH
THE AREA.
BY SUNDAY MORNING...THE LINE OF STORMS WILL BE NEARING THE EASTERN
COUNTIES AND SHOULD MOVE OUT OF THE CWA SOMETIME AROUND 18Z. THE
THREAT OF FLOODING RAINS AND SOME SEVERE WEATHER WILL CONTINUE
SUNDAY MORNING. BY SUNDAY AFTERNOON...CAPE VALUES INCREASE TO
ABOVE 3000 J/KG WHICH IS SOMEWHAT INITIALLY CONCERNING.
HOWEVER...FORECAST SOUNDINGS SHOW DECENT AMOUNTS OF DRYING ALOFT
BEHIND THE INITIAL WAVE WHICH SHOULD LIMIT ACTIVITY. ALSO...THE
ENVIRONMENT SHOULD BE PRETTY WORKED OVER FROM THE OVERNIGHT AND
MORNING ACTIVITY. THE ONE AREA TO WATCH WILL BE THE WESTERN
COUNTIES WHERE THE MOST RECOVERY TIME WILL BE AND SOME HIGH-RES
MEMBERS ARE SHOWING THE POTENTIAL FOR REDEVELOPMENT SUNDAY
AFTERNOON IN THIS GENERAL AREA.
RAINFALL AMOUNTS THIS MORNING THROUGH SUNDAY WILL AVERAGE 1-4
INCHES WITH THE HIGHER AMOUNTS NEAR THE I-35 CORRIDOR. WE MUST
CONTINUE TO STRESS TO ANYONE ON LOCAL RIVERS AND LAKES THIS
HOLIDAY WEEKEND TO PAY VERY CLOSE ATTENTION TO THE WEATHER AND ANY
WARNINGS THAT ARE ISSUED. HAVE A PLAN IN PLACE TO SEEK SHELTER
AND ALWAYS REMEMBER TO TURN AROUND...DONT DROWN.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
SHOULD SEE A LULL IN ACTIVITY EARLY SUNDAY NIGHT...BUT THIS
SHOULD UNFORTUNATELY BE BRIEF. CURRENTLY ON WATER VAPOR
IMAGERY...ANOTHER IMPULSE ASSOCIATED WITH THE MAIN UPPER LOW CAN
BE SEEN NEAR THE WASHINGTON AND OREGON BORDER. 00Z GUIDANCE SEEMS
TO HAVE PICKED UP ON THIS FEATURE QUITE WELL AND BRINGS IT INTO
TEXAS FOR MONDAY /MEMORIAL DAY/. SUBSEQUENTLY...THE 00Z MODEL
GUIDANCE HAS INCREASED THE QPF AMOUNTS FORECASTED FOR MONDAY
AFTERNOON. THE GFS IS THE HIGHEST OF ALL GUIDANCE WITH ANOTHER 2
INCHES OF RAIN FOR THE I-35 CORRIDOR. WENT AHEAD AND INCREASED
RAIN TOTALS IN THE OFFICIAL FORECAST...BUT NOT QUITE AS HIGH AS
THE GFS IS ADVERTISING. IF CONFIDENCE INCREASES THAT UP TO ANOTHER
2 INCHES OF RAIN WILL FALL ON MONDAY....THE FLASH FLOOD WATCH WILL
NEED TO BE EXTENDED AT A LATER TIME. CAPE/SHEAR VALUES WILL
SUPPORT THE THREAT OF SEVERE WEATHER AS WELL. FORECAST SOUNDINGS
DUE SHOW THE THREAT FOR HAIL...DAMAGING WINDS AND POSSIBLE
ISOLATED TORNADOES FOR MONDAY AFTERNOON. THE OVERALL THREAT FOR
TORNADOES WILL BE HIGHLY DEPENDENT ON THE OVERALL COVERAGE OF
ACTIVITY AND IF ANY DISCRETE SUPERCELLS ARE AVAILABLE TO DEVELOP.
AGAIN...ANYONE OUTDOORS ON THE HOLIDAY NEED TO MAKE SURE TO HAVE A
PLAN AND BE READY TO SEEK SHELTER.
THE UPPER AIR PATTERN BECOMES MORE ZONAL ON TUESDAY WITH WEAK
RIDGING ON WEDNESDAY. OVERALL COVERAGE OF ACTIVITY SHOULD DECREASE
FOR MID-WEEK. POPS WILL SLIGHTLY INCREASE ONCE AGAIN TOWARDS THE
END OF THE WORK WEEK AS THE NEXT DISTURBANCE NEARS THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 81 68 81 71 82 / 60 90 60 40 60
AUSTIN BERGSTROM INTL AIRPORT 81 68 81 70 82 / 60 90 70 40 60
NEW BRAUNFELS MUNI AIRPORT 82 68 82 71 82 / 60 90 60 40 60
BURNET MUNI AIRPORT 79 66 80 69 81 / 60 90 60 30 50
DEL RIO INTL AIRPORT 82 68 89 70 87 / 80 70 30 20 40
GEORGETOWN MUNI AIRPORT 80 68 80 70 82 / 60 90 60 40 60
HONDO MUNI AIRPORT 82 66 84 70 82 / 70 90 50 30 60
SAN MARCOS MUNI AIRPORT 81 68 80 70 82 / 60 90 60 40 60
LA GRANGE - FAYETTE REGIONAL 83 69 80 71 82 / 40 80 80 50 70
SAN ANTONIO INTL AIRPORT 82 68 82 72 83 / 60 90 60 30 60
STINSON MUNI AIRPORT 83 69 83 72 83 / 60 90 60 30 60
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SUNDAY EVENING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DE WITT...DIMMIT...EDWARDS...FAYETTE...FRIO...
GILLESPIE...GONZALES...GUADALUPE...HAYS...KARNES...KENDALL...KERR...
KINNEY...LAVACA...LEE...LLANO...MAVERICK...MEDINA...REAL...TRAVIS...
UVALDE...VAL VERDE...WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...10
SYNOPTIC/GRIDS...TREADWAY
PUBLIC SERVICE/DATA COLLECTION...33