Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/23/14
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
1125 AM PDT WED MAY 21 2014
...NEW AVIATION/MARINE DISCUSSIONS...
.SYNOPSIS...
LOW PRESSURE WILL LINGER OVER THE AREA THROUGH THURSDAY...BRINGING A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS...MAINLY OVER THE
MOUNTAINS. A GRADUAL WARMING TREND IS EXPECTED THROUGH THE END OF
THE WEEK AS LOW PRESSURE SLOWLY MOVES EAST...WITH TEMPERATURES
RETURNING TO NEAR NORMAL BY FRIDAY. SLIGHTLY ABOVE NORMAL
TEMPERATURES ARE EXPECTED FOR THE WEEKEND AS HIGH PRESSURE RETURNS.
&&
.SHORT TERM (TODAY-FRI)...THE UPPER LOW HAS MOVED INTO NEVADA,
LEAVING US ON THE BACK SIDE OF THE TROF WITH NORTHERLY FLOW AND
STILL DECENT INSTABILITY DURING THE AFTERNOON. MARINE LYR ENDED UP
FILLING IN DECENTLY N OF PT CONCEPTION BUT AS EXPECTED NOT AS SOLID
IN THE SOUTH WITH A MUCH WEAKER AND DEEPER INVERSION. SURFACE
HEATING SHOULD HELP STRATOCU DEVELOP A LITTLE MORE THROUGH THE
AFTERNOON SO PARTLY CLOUDY A GOOD FORECAST FOR MOST COAST/VALLEY
AREAS. GOOD CHANCE OF SOME ISOLATED THUNDERSTORM DEVELOPMENT TODAY,
MAINLY FROM SE SLO COUNTY THROUGH THE SBA AND VENTURA MTNS. SOMEWHAT
LESSER CHANCES OVER LA COUNTY BUT CERTAINLY NOT ZERO. STEERING FLOW
IS FROM THE NORTHWEST AT AROUND 20-25 KT SO THERE IS ALSO A NON-ZERO
CHANCE OF THE REMNANTS OF ANY MTN CONVECTION TO DRIFT SOUTH INTO THE
ADJACENT FOOTHILLS AND VALLEYS. THE HRRR MODEL SHOWS THE BEST
CHANCES OF THIS ACROSS THE VENTURA COUNTY VALLEYS BETWEEN OJAI AND
PIRU LATE THIS AFTERNOON. LIKELY JUST SOME SPRINKLES OR VERY LIGHT
SHOWERS AT BEST.
MODELS CONTINUE TO ADVERTISE ADDITIONAL UPPER LEVEL ENERGY MOVING
INTO THE AREA FROM THE NORTH TONIGHT WHICH MAY BE ENOUGH TO MAINTAIN
A THREAT OF SHOWERS, MAINLY IN THE MTNS. MARINE LYR SITUATION
EXPECTED TO VERY SIMILAR TO THIS MORNING, THUS PRETTY SOLID UP NORTH
AND MORE SCATTERED IN THE SOUTH.
THE NAM HAS GONE BACK TO THU AS IT`S FAVORED CONVECTIVE DAY. IT`S
ALSO SHOWING BETTER INSTABILITY OVER THE VALLEYS WHILE THE STEERING
FLOW SHIFTS TO THE NORTHEAST. WILL CERTAINLY BE LOOKING INTO ADDING
SOME POPS FOR VALLEY AREAS FOR THU, ESPECIALLY IF WE GET SOME DRIFT
OFF TODAY. TEMPERATURES PERHAPS A SKOSH WARMER BUT JUST A COUPLE
DEGREES AT MOST.
***FROM PREVIOUS DISCUSSION***
THE MARINE LAYER WILL REESTABLISH ITSELF THU NIGHT AND SHOULD COVER
MOST OF THE COASTS AS WELL AS THE SANTA YNEZ VLY. ANOTHER WEAK
SUNDOWNER SHOULD KEEP THE SBA SOUTH COAST CLOUD FREE.
FRIDAY IS AN IN BETWEEN DAY AS THE PESKY UPPER LOW SLOWLY MOVES TO
THE EAST AND AN UPPER HIGH NOSES INTO NRN CA FROM THE WEST. SKIES
MAY BE PARTLY CLOUDY OVER L.A. COUNTY AS THE LAST EFFECTS OF THE UPR
LOW WILL STILL BE OVER IT. OTHERWISE THE BUILDING UPPER HIGH WILL
BRING MOSTLY CLEAR SKIES AND SOME WARMING ESP TO THE INTERIOR OF SLO
COUNTY WHICH WILL SEE THE GREATEST HGT RISES.
.LONG TERM (SAT-TUE)...
THE UPPER HIGH TAKES CONTROL OF THE HOLIDAY WEEKEND. THE WARM AIR
ALOFT WILL ESTABLISH A STRONG MARINE INVERSION BUT THE HIGH PRESSURE
ALOFT WILL SMOOSH THE MARINE LAYER TO ABOUT 1000 FEET OR TOO LOW TO
MAKE ANY SIGNIFICANT VLY PENETRATION. MAX TEMPS WILL JUMP NICELY
EVERYWHERE EXCEPT THE COAST AND TO SOME DEGREE THE VLYS WHERE THE
MARINE LAYER AND A STIFF SEA BREEZE WILL SERVE TO MODERATE THE WARM
UP. THE CSTS SHOULD STAY BELOW NORMAL AND THE VLYS WILL ONLY WARM TO
JUST BELOW NORMAL. THE MTNS AND THE REST OF THE INTERIOR WILL WARM
TO ABOVE NORMAL. RIGHT NOW SUNDAY LOOKS LIKE THE WARMEST DAY BUT
MDLS SOMETIMES COOL THINGS OFF TOO QUICKLY SO MONDAY COULD PRETTY
EASILY BE A REPEAT OF SUNDAY. EITHER WAY NOT BAD A HOLIDAY WEEKEND
AT ALL.
THE RIDGE FLATTENS OUT TUESDAY AND MAX TEMPS SHOULD COOL 3 TO 6
DEGREES. THE MARINE LAYER SHOULD SNEAK INTO THE VLYS AS WELL.
&&
.AVIATION...21/1800Z.
LOW CONFIDENCE IN THE 18Z TAF PACKAGE. A LARGE CUTOFF LOW HAS A
LARGE CLOUD SHIELD ROTATING AROUND IT AND THE LOW IS HEADING FOR LOS
ANGELES COUNTY ON THURSDAY. THE TAF PACKAGE WAS CHANGED TO BE MORE
PESSIMISTIC IN TERMS OF GREATER CLOUD COVERAGE. A CHAOTIC
STRATOCUMULUS DECK IS FORMING IN THE DAYTIME HEATING TODAY...SO THAT
ANY TAF SITE MAY SEE BKN CONDITIONS AT JUST ABOUT ANY TIME OF DAY
AND THE SITUATUION ONLY GESTS WORSE FOR THURSDAY. THERE WILL BE NO
TEMPORAL CONSISTENCY IN CLOUD COVER WITH SCT TO BKN CONDITIONS AND
OCCASIONAL MVFR CEILINGS FOR THE NEXT 24 HOURS. THE ANTELOPE VALLEY
WILL HAVE GUSTY WINDS IN THE AFTERNOON AND EVENING. IN ADDITION...A
FEW SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED OVER THE
MOUNTAINS THROUGH THURSDAY WITH THE HIGHEST CHANCES DURING THE
AFTERNOON AND EARLY EVENING. ONE OR TWO SHOWERS MAY EVEN DRIFT INTO
THE LA/VENTURA COUNTY VALLEYS ON THURSDAY.
KLAX AND KBUR...LOW CONFIDENCE IN THE 18Z TAF FORECAST. THERE WILL
BE PERIODS OF CLOUDINESS AND SCT TO BKN CONDITIONS WITH OCCASIONAL
MVFR CONDITIONS.
&&
.MARINE...21/900 AM...
ACROSS THE OUTER WATERS...MODERATE CONFIDENCE IN SMALL CRAFT
ADVISORY LEVEL WINDS THROUGH THIS EVENING. THERE IS A CHANCE THAT
WINDS COULD REMAIN AT SMALL CRAFT LEVELS THROUGH THURSDAY. FOR
FRIDAY THROUGH THE WEEKEND...WINDS ARE ANTICIPATED TO CONTINUE AT
LEAST AROUND THE SMALL CRAFT ADVISORY LEVELS. THE LATEST MODEL DATA
DOES SHOW THE POSSIBILITY OF GALE FORCE WINDS RETURNING TO PZ670 AND
PZ673 FRIDAY EVENING AND CONTINUING INTO SATURDAY. THERE IS LOW TO
MODERATE CONFIDENCE IN THIS SCENARIO.
ACROSS THE INNER WATERS...WINDS ARE GENERALLY EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY LEVELS THROUGH THE WEEKEND. WESTERN
SECTIONS COULD EXPERIENCE SOME LOCAL GUSTS TO 25 KNOTS...ESPECIALLY
IN THE AFTERNOON AND EVENING HOURS. THERE IS GOOD CONFIDENCE IN THIS
SCENARIO.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...MW/RORKE
AVIATION/MARINE...SWEET
SYNOPSIS...SUKUP
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS RENO NV
1040 AM PDT WED MAY 21 2014
.UPDATE...
UPDATED TO RAISE AFTERNOON POP, MAINLY FOR FAR WESTERN NEVADA. I
ALSO LOWERED HIGHS A FEW DEGREES, GENERALLY SOUTH OF A GERLACH TO
PORTOLA LINE, WITH MORE SHOWERS EXPECTED FOR THIS AFTERNOON. AS
FAR AS THE POP INCREASE, THE NAM AND HRRR MODELS APPEAR TO BE ON
TRACK FOR THIS AFTERNOON (WITH BRINGING A BAND OF SHOWERS/POSSIBLE
STORMS INTO WESTERN NEVADA) BASED ON RECENT RADAR AND SATELLITE
OBSERVATIONS SO THOSE SOLUTIONS WERE ACCEPTED. SNYDER
&&
.SYNOPSIS...
LOW PRESSURE LINGERING OVER CALIFORNIA AND NEVADA WILL CONTINUE TO
BRING COOLER AND BREEZY CONDITIONS ALONG WITH RAIN SHOWERS, ISOLATED
THUNDERSTORMS AND HIGH ELEVATION SNOW THROUGH EARLY THURSDAY. HIGH
PRESSURE WILL SLOWLY BUILD BACK INTO THE REGION BRINGING WARMER AND
DRIER CONDITIONS FOR THE END OF THE WEEK.
&&
.PREVIOUS DISCUSSION... /ISSUED 321 AM PDT WED MAY 21 2014/
SHORT TERM...
ONLY SLIGHT ADJUSTMENTS WERE NECESSARY TO THE EXISTING FORECAST.
THIS MAINLY CONCERNED INCREASING EXTENT OF LOW CHANCES OF SHOWERS
WITH ISOLATED THUNDERSTORMS NORTHWEST INTO NORTHWESTERN LASSEN
COUNTY. OTHERWISE, VERY LITTLE HAS CHANGED. LOW PRESSURE CONTINUES
TO INFLUENCE THE PATTERN BRINGING MORE SHOWERS AND ISOLATED
THUNDERSTORMS TODAY. ALTHOUGH, PRECIPITATION WILL NOT BE NEARLY AS
CONSISTENT AS YESTERDAY. WILL CONTINUE TO WATCH THE HUNTER FALLS
BURN SCAR IN CASE CELLS BEGIN TO TRAIN OR BECOME ANCHORED SINCE
UPPER FLOW IS UPSLOPE OUT OF THE NORTHEAST BECOMING RATHER LIGHT
THROUGH THE DAY. HOWEVER, THIS IS ON THE LOWER END OF POSSIBILITY
SINCE SHOWERS SHOULD BE MORE SCATTERED TODAY.
SHORT-TERM MODELS HAVE SHOWN MORE INSTABILITY AND MOISTURE FARTHER
NORTHWEST DURING THE AFTERNOON TODAY. ALSO, THEY ARE A LITTLE
SLOWER WITH THE EXIT OF LOW PRESSURE. AS A RESULT, HAVE ADDED
THE POSSIBILITY OF SHOWERS WITH ISOLATED THUNDERSTORMS FOR MUCH OF
LASSEN COUNTY WITH HIGHER CHANCES ALONG THE WARNERS. SHOWERS SEEMS
TO BE LINGERING FOR MONO COUNTY AS WELL. KEPT LIKELY WORDING
THROUGH THIS EVENING.
HIGH PRESSURE BEGINS TO DISPLACE THE LOW THURSDAY AFTERNOON AND
EVENING RETURNING THE AREA TO A WARMING TREND. HIGH TEMPERATURES
QUICKLY REBOUND BY FRIDAY WITH WESTERN NEVADA VALLEYS IN THE MID
80S AND MOSTLY CLEAR SKIES. ANOTHER WEAK TROUGH TRIES TO MOVE INTO
THE RIDGE IN NORTHERN LASSEN COUNTY EARLY FRIDAY, BUT DID NOT
RAISE PRECIPITATION CHANCES YET. WAITING FOR A CLEARER SIGNAL THAT
THE TROUGH WILL BE STRONG ENOUGH TO DEPRESS THE NORTHERN PERIPHERY
OF THE RIDGE. BOYD
LONG TERM...SATURDAY THROUGH TUESDAY...
UPPER LOW CONTINUES TO PUSH EAST OVER THE WEEKEND, ALLOWING FOR
RIDGING TO BUILD BACK OVER NORTHERN CA/NV. 700MB TEMPERATURES WILL
INCREASE SHARPLY OVER THE WEEKEND, TOPPING OFF AT AROUND +10C. THIS
WILL MEAN HIGH TEMPS IN THE LOWER ELEVATIONS REACHING INTO THE UPPER
80S WITH 70S IN THE SIERRA. THE STRONG HEATING WILL ALSO LEAD TO
INCREASED INSTABILITY OVER THE SIERRA. INTRODUCED A SLIGHT CHANCE OF
THUNDERSTORMS OVER THE SIERRA CREST ON SATURDAY AND SUNDAY
AFTERNOON/EVENINGS. THERE ISN`T MUCH IN THE WAY OF FORCING, SO
THUNDERSTORM DEVELOPMENT LOOKS VERY MARGINAL. ALTHOUGH, WITH THE
AMOUNT OF HEATING AND INSTABILITY WE WILL SEE THIS WEEKEND, A SLIGHT
CHANCE OF THUNDERSTORMS IS POSSIBLE.
BY MEMORIAL DAY, LOW PRESSURE BEGINS TO DROP INTO THE PAC NW. THE
JET STREAM LOOKS TO REMAIN OVER WA/OR, WHICH IS TRENDING FURTHER
NORTH THAN WE`VE SEEN OVER THE LAST FEW DAYS. THIS WILL STILL LEAD
TO GUSTY WINDS ON MONDAY ALTHOUGH MAYBE NOT QUITE AS STRONG AS
PREVIOUSLY THOUGHT. STILL, GUSTY WINDS UP TO 35-40 MPH COULD CREATE
PROBLEMS FOR AREA LAKES ON MEMORIAL DAY. SINCE THE MOISTURE WILL
REMAIN WELL TO THE NORTH IN THE PAC NW, WARM AND DRY CONDITIONS MAY
COMBINE WITH GUSTY WINDS ON MONDAY FOR FIRE WEATHER CONCERNS.
BACK DOOR COLD FRONT WILL PUSH DOWN THROUGH THE GREAT BASIN ON
TUESDAY. THIS WILL BRING TEMPERATURES BACK DOWN TO NEAR NORMALS WITH
MID TO UPPER 70S IN THE DESERT VALLEYS AND 60S IN THE SIERRA. HOON
AVIATION...
BAND OF RAIN AND HIGH ELEVATION SNOW WILL CONTINUE TO AFFECT WESTERN
NEVADA THROUGH TODAY. MVFR CIGS WILL BE POSSIBLE FOR AREA TERMINALS
THROUGH THIS AFTERNOON. A FEW THUNDERSTORMS ARE ALSO POSSIBLE THIS
AFTERNOON AS WE GET ADDITIONAL HEATING. THUNDERSTORMS WILL BE PRETTY
ISOLATED WITH ONLY A 10% CHANCE OF THUNDERSTORMS AFFECTING EACH
TERMINAL. HOON
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
935 AM PDT WED MAY 21 2014
.SYNOPSIS...
LOW PRESSURE WILL LINGER OVER THE AREA THROUGH THURSDAY...BRINGING A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS...MAINLY OVER THE
MOUNTAINS. A GRADUAL WARMING TREND IS EXPECTED THROUGH THE END OF
THE WEEK AS LOW PRESSURE SLOWLY MOVES EAST...WITH TEMPERATURES
RETURNING TO NEAR NORMAL BY FRIDAY. SLIGHTLY ABOVE NORMAL
TEMPERATURES ARE EXPECTED FOR THE WEEKEND AS HIGH PRESSURE RETURNS.
&&
.SHORT TERM (TODAY-FRI)...THE UPPER LOW HAS MOVED INTO NEVADA,
LEAVING US ON THE BACK SIDE OF THE TROF WITH NORTHERLY FLOW AND
STILL DECENT INSTABILITY DURING THE AFTERNOON. MARINE LYR ENDED UP
FILLING IN DECENTLY N OF PT CONCEPTION BUT AS EXPECTED NOT AS SOLID
IN THE SOUTH WITH A MUCH WEAKER AND DEEPER INVERSION. SURFACE
HEATING SHOULD HELP STRATOCU DEVELOP A LITTLE MORE THROUGH THE
AFTERNOON SO PARTLY CLOUDY A GOOD FORECAST FOR MOST COAST/VALLEY
AREAS. GOOD CHANCE OF SOME ISOLATED THUNDERSTORM DEVELOPMENT TODAY,
MAINLY FROM SE SLO COUNTY THROUGH THE SBA AND VENTURA MTNS. SOMEWHAT
LESSER CHANCES OVER LA COUNTY BUT CERTAINLY NOT ZERO. STEERING FLOW
IS FROM THE NORTHWEST AT AROUND 20-25 KT SO THERE IS ALSO A NON-ZERO
CHANCE OF THE REMNANTS OF ANY MTN CONVECTION TO DRIFT SOUTH INTO THE
ADJACENT FOOTHILLS AND VALLEYS. THE HRRR MODEL SHOWS THE BEST
CHANCES OF THIS ACROSS THE VENTURA COUNTY VALLEYS BETWEEN OJAI AND
PIRU LATE THIS AFTERNOON. LIKELY JUST SOME SPRINKLES OR VERY LIGHT
SHOWERS AT BEST.
MODELS CONTINUE TO ADVERTISE ADDITIONAL UPPER LEVEL ENERGY MOVING
INTO THE AREA FROM THE NORTH TONIGHT WHICH MAY BE ENOUGH TO MAINTAIN
A THREAT OF SHOWERS, MAINLY IN THE MTNS. MARINE LYR SITUATION
EXPECTED TO VERY SIMILAR TO THIS MORNING, THUS PRETTY SOLID UP NORTH
AND MORE SCATTERED IN THE SOUTH.
THE NAM HAS GONE BACK TO THU AS IT`S FAVORED CONVECTIVE DAY. IT`S
ALSO SHOWING BETTER INSTABILITY OVER THE VALLEYS WHILE THE STEERING
FLOW SHIFTS TO THE NORTHEAST. WILL CERTAINLY BE LOOKING INTO ADDING
SOME POPS FOR VALLEY AREAS FOR THU, ESPECIALLY IF WE GET SOME DRIFT
OFF TODAY. TEMPERATURES PERHAPS A SKOSH WARMER BUT JUST A COUPLE
DEGREES AT MOST.
***FROM PREVIOUS DISCUSSION***
THE MARINE LAYER WILL REESTABLISH ITSELF THU NIGHT AND SHOULD COVER
MOST OF THE COASTS AS WELL AS THE SANTA YNEZ VLY. ANOTHER WEAK
SUNDOWNER SHOULD KEEP THE SBA SOUTH COAST CLOUD FREE.
FRIDAY IS AN IN BETWEEN DAY AS THE PESKY UPPER LOW SLOWLY MOVES TO
THE EAST AND AN UPPER HIGH NOSES INTO NRN CA FROM THE WEST. SKIES
MAY BE PARTLY CLOUDY OVER L.A. COUNTY AS THE LAST EFFECTS OF THE UPR
LOW WILL STILL BE OVER IT. OTHERWISE THE BUILDING UPPER HIGH WILL
BRING MOSTLY CLEAR SKIES AND SOME WARMING ESP TO THE INTERIOR OF SLO
COUNTY WHICH WILL SEE THE GREATEST HGT RISES.
.LONG TERM (SAT-TUE)...
THE UPPER HIGH TAKES CONTROL OF THE HOLIDAY WEEKEND. THE WARM AIR
ALOFT WILL ESTABLISH A STRONG MARINE INVERSION BUT THE HIGH PRESSURE
ALOFT WILL SMOOSH THE MARINE LAYER TO ABOUT 1000 FEET OR TOO LOW TO
MAKE ANY SIGNIFICANT VLY PENETRATION. MAX TEMPS WILL JUMP NICELY
EVERYWHERE EXCEPT THE COAST AND TO SOME DEGREE THE VLYS WHERE THE
MARINE LAYER AND A STIFF SEA BREEZE WILL SERVE TO MODERATE THE WARM
UP. THE CSTS SHOULD STAY BELOW NORMAL AND THE VLYS WILL ONLY WARM TO
JUST BELOW NORMAL. THE MTNS AND THE REST OF THE INTERIOR WILL WARM
TO ABOVE NORMAL. RIGHT NOW SUNDAY LOOKS LIKE THE WARMEST DAY BUT
MDLS SOMETIMES COOL THINGS OFF TOO QUICKLY SO MONDAY COULD PRETTY
EASILY BE A REPEAT OF SUNDAY. EITHER WAY NOT BAD A HOLIDAY WEEKEND
AT ALL.
THE RIDGE FLATTENS OUT TUESDAY AND MAX TEMPS SHOULD COOL 3 TO 6
DEGREES. THE MARINE LAYER SHOULD SNEAK INTO THE VLYS AS WELL.
&&
.AVIATION...21/1140Z...
OVERALL...MODERATE CONFIDENCE IN 12Z TAF PACKAGE. CURRENT MVFR CONDS
ACROSS THE CENTRAL COAST AND LAX COAST SHOULD MIX OUT BY LATE THIS
MORNING. OTHERWISE...EXPECT SCT TO LOCALLY BKN VFR CLOUD DECK
THROUGH THIS EVENING. FOR TONIGHT...MODERATE CONFIDENCE IN RETURN OF
MVFR CIGS TO THE CENTRAL COAST AND LAX COAST.
KLAX...MODERATE CONFIDENCE IN 12Z TAF. THERE IS A 50% CHANCE THAT
CURRENT MVFR CIGS COULD MIX OUT BEFORE 16Z. FOR TONIGHT...LOW
CONFIDENCE IN RETURN OF MVFR CIGS. EAST WINDS THIS MORNING SHOULD
REMAIN BELOW 7 KNOTS.
KBUR...HIGH CONFIDENCE IN 12Z TAF. THERE IS A 20% CHANCE OF MVFR
CIGS LATE TONIGHT...AFTER 10Z.
&&
.MARINE...21/900 AM...
ACROSS THE OUTER WATERS...MODERATE CONFIDENCE IN SMALL CRAFT
ADVISORY LEVEL WINDS THROUGH THIS EVENING. THERE IS A CHANCE THAT
WINDS COULD REMAIN AT SMALL CRAFT LEVELS THROUGH THURSDAY. FOR
FRIDAY THROUGH THE WEEKEND...WINDS ARE ANTICIPATED TO CONTINUE AT
LEAST AROUND THE SMALL CRAFT ADVISORY LEVELS. THE LATEST MODEL DATA
DOES SHOW THE POSSIBILITY OF GALE FORCE WINDS RETURNING TO PZ670 AND
PZ673 FRIDAY EVENING AND CONTINUING INTO SATURDAY. THERE IS LOW TO
MODERATE CONFIDENCE IN THIS SCENARIO.
ACROSS THE INNER WATERS...WINDS ARE GENERALLY EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY LEVELS THROUGH THE WEEKEND. WESTERN
SECTIONS COULD EXPERIENCE SOME LOCAL GUSTS TO 25 KNOTS...ESPECIALLY
IN THE AFTERNOON AND EVENING HOURS. THERE IS GOOD CONFIDENCE IN THIS
SCENARIO.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...MW/RORKE
AVIATION/MARINE...RAT/SWEET
SYNOPSIS...SUKUP
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1140 AM MDT WED MAY 21 2014
.UPDATE...
ISSUED AT 1111 AM MDT WED MAY 21 2014
CURRENT FORECAST/SEVERE THREAT LOOKS ON TRACK...WITH LATEST HRRR
RUNS SUGGESTING CONVECTIVE INITIATION BETWEEN 19Z-20Z. STILL
APPEARS BEST TORNADO/SUPERCELL THREAT WILL BE NORTH NEAR THE
DCVZ INTO NE CO...WITH MORE OF A WIND/HAIL THREAT FARTHER SOUTH
WHERE T/TD SPREADS WILL BE LARGER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM MDT WED MAY 21 2014
...SEVERE THUNDERSTORMS POSSIBLE NORTHERN PORTIONS OF THE SOUTHEAST
PLAINS...CRITICAL FIRE WEATHER CONDITIONS EXPECTED ACROSS THE SAN
LUIS VALLEY...
UPPER LOW WILL STALL OUT OVER NEVADA TODAY BEFORE DROPPING SOUTHWARD
INTO SOUTHERN CA LATER TONIGHT. SOUTHERLY FLOW AHEAD OF THE SYSTEM
TODAY WILL START TO SHIFT SOME MID/HIGH LEVEL MOISTURE INTO THE
WESTERN MTS TODAY...BUT BY IN LARGE...LOWER LEVELS WILL REMAIN QUITE
DRY. WITH SOUTH TO SOUTHWEST WINDS INCREASING AGAIN ACROSS THE
SOUTHWEST MTS AND SAN LUIS VALLEY...EXPECT A RETURN OF CRITICAL FIRE
WEATHER CONDITIONS FOR THE SAN LUIS VALLEY WHERE FUELS ARE
CRITICALLY DRY. RAPID RATES OF FIRE SPREAD WILL BE POSSIBLE WITH
ANY FIRE STARTS AND CURRENT RED FLAG WARNING STILL LOOKS GOOD.
THERE COULD BE SOME ISOLATED HIGH BASED THUNDERSTORMS ALONG THE
CONTDVD TODAY...BUT THEY WILL BE FEW AND FAR BETWEEN...AND WITH
INVERTED V SOUNDINGS...MORE LIKELY TO PRODUCE GUSTY WINDS THAN MUCH
IN THE WAY OF RAINFALL.
DIFFERENT STORY WILL EXIST TODAY FOR THE SOUTHEAST PLAINS. LOW LEVEL
MOISTURE HAS SPREAD BACK IN WITH CURRENT DEW POINTS IN THE 50S FOR
THE LOWER ARKANSAS RIVER...WITH UPPER 40S FOR CANON CITY...AND EVEN
WOODLAND PARK SEEING LOWER 40 DEW POINTS. SOUTHERN I-25 CORRIDOR IS
STILL QUITE DRY WITH KTAD DEW POINT AT 13 AS OF 09Z. BOUNDARY WILL
CONTINUE TO PUSH SLOWLY SOUTHWARD THIS MORNING WITH STRATUS
EXPANDING ACROSS SOUTHEAST CO IN LIGHT UPSLOPE REGIME ALONG THE
LOWER EASTERN SLOPES OF TELLER/EL PASO COUNTY...THE LOWER WET
MOUNTAINS...AND THE NORTHERN SLOPES OF THE RATON RIDGE. THIS SHOULD
BURN OFF DURING THE LATE MORNING WITH DEW POINTS STAYING IN THE
UPPER 40S/LOWER 50S THROUGH EARLY AFTERNOON ACROSS THE MAJORITY OF
THE SOUTHEAST PLAINS. VORT MAX ACROSS NEW MEXICO WILL MOVE IN THIS
AFTERNOON...AND DRIER AIR WILL BEGIN TO MIX NORTHWARD OFF THE RATON
RIDGE. MAIN FACTOR DETERMINING EXTENT OF SEVERE WEATHER POTENTIAL
WILL BE HOW QUICKLY THESE DEW POINTS MIX OUT. HRRR AND RAP13 DROPS
DEW POINTS INTO THE UPPER 30S FOR THE I-25 CORRIDOR WITH 40S FARTHER
EAST BY 21Z. NAM12 AND LOCAL 4KM WRF KEEPS DEW POINTS IN THE LOWER
50S AT 21Z NORTHEAST OF A LINE FROM KCOS...TO KLHX...TO KSPD. SO
CAPES COULD BE AS LOW AS 500 J/KG ALONG THE I-25 CORRIDOR TO AROUND
1500 J/KG ACROSS KIOWA...BENT...PROWERS COUNTIES IF THE RAP IS
CORRECT. OR THEY COULD BE AROUND 1500+ J/KG IF THE NAM12 IS
CORRECT. EITHER WAY...0-6KM SHEARS WILL BE RUNNING AROUND 40-50
KTS...OR EVEN A LITTLE BETTER IF LOW LEVEL WINDS STAY OUT OF THE
EAST...WHICH WOULD SUPPORT DEVELOPMENT OF SUPERCELL THUNDERSTORMS.
BEST CHANCES FOR SEVERE LOOK TO BE ACROSS NORTHERN SECTIONS OF THE
SOUTHEAST PLAINS...WHERE HIGHER DEW POINTS ARE MORE LIKELY TO STAY
IN THE LONGEST. INITIATION MAY OCCUR ALONG THE NORTHERN SLOPES OF
THE RATON MESA AROUND 1 PM...WITH THUNDERSTORMS SPREADING/DEVELOPING
NORTHWARD ACROSS THE SOUTHEAST PLAINS THROUGH THE AFTERNOON.
MAJORITY OF THE ACTIVITY MOVES OUT OF THE AREA BY 00Z AS VORT MAX
LIFTS NORTHWARD. LARGE HAIL AND DAMAGING WINDS WILL BE THE MOST
LIKELY SEVERE THREAT...ESPECIALLY TO THE NORTH OF THE ARKANSAS
RIVER. IF DEW POINTS CAN STAY HIGH ENOUGH...THUS...LCLS LOW
ENOUGH...THERE COULD BE ENOUGH LOW LEVEL HELICITY FOR AN ISOLATED
TORNADO. THIS WOULD BE MORE LIKELY TO OCCUR ALONG THE PALMER DIVIDE
AND KIOWA COUNTY...BUT THREAT FOR THIS APPEARS ON THE LOWER SIDE OF
THE SPECTRUM AT THIS POINT. POTENTIAL FOR DAMAGING WIND GUSTS WILL
EXTEND FARTHER SOUTHWARD ACROSS THE SOUTHEAST PLAINS THAN HAIL
THREAT DUE TO HIGHER AVAILABLE DOWNDRAFT CAPE. WILL LIKELY PLAY THE
SEVERE THREAT AREA NORTHEAST OF A LINE FROM COLORADO SPRINGS...TO LA
JUNTA...TO TWO BUTTES.
FINAL CONCERN IS FOR POTENTIAL FOR HEAVY RAINFALL ON THE BURN SCARS
THIS AFTERNOON...PARTICULARLY ACROSS WALDO AND BLACK FOREST. WINDOW
FOR GREATEST THREAT WILL BE FROM 2 PM TO 6 PM...PROBABLY CENTERED
MORE IN THE 3 TO 5 PM RANGE FOR WALDO. AGAIN...STRENGTH OF
UPDRAFTS/POTENTIAL RAINFALL EFFICIENCIES WILL DEPEND ON HOW MUCH LOW
LEVEL MOISTURE STAYS IN. HUNCH IS THAT HIGHER TERRAIN WILL MIX OUT
AT LEAST SOME OF THE LOW LEVEL MOISTURE AND LCLS WILL BE UP AROUND
11-12KFT MSL...WHICH WILL ALLOW FOR SOME EVAPORATION BELOW CLOUD
BASE. ALTHOUGH THREAT FOR FLASH FLOOD PRODUCING RAINFALL IS THERE
TODAY...THINK THE THREAT IS BELOW A 40 PERCENT PROBABILITY. MORE
LIKELY SCENARIO IS FOR SOME RAINFALL AMOUNTS GENERALLY IN THE
.10 TO .40 RANGE...WHICH COULD MEAN SOME FLOOD ADVISORY RAINFALL
CAUSING MINOR RUN OFF FOR THE WALDO BURN SCAR. MAJORITY OF THE HIGH
RES MODELS SUGGEST THE LESSER IMPACT SCENARIO...BUT SITUATION WILL
REQUIRE CLOSE MONITORING THROUGH THE AFTERNOON AND EARLY EVENING
HOURS.
THUNDERSTORMS WILL COME TO AN END DURING THE EVENING FOR MOST
AREAS...WITH ANOTHER INTRUSION OF STRATUS TOWARDS MORNING ACROSS
NORTHERN PORTIONS OF THE SOUTHEAST PLAINS. -KT
.AVIATION... MVFR CIGS WILL CONTINUE TO EXPAND ACROSS THE SOUTHEAST
PLAINS THROUGH MORNING...WITH SOME POCKETS OF IFR CIGS ACROSS THE
PIKES PEAK REGION AND ALONG THE LOWER EASTERN SLOPES OF THE
SOUTHEAST MOUNTAINS. COULD EVEN SEE SOME PATCHY FOG. STRATUS
SHOULD ERODE BY 17-18Z FOR MOST AREAS WITH ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING DURING THE EARLY AFTERNOON ACROSS THE
SOUTHEAST MOUNTAINS AND NORTHERN SLOPES OF THE RATON RIDGE. THESE
WILL BE CAPABLE OF PRODUCING VFR TO LOCAL MVFR CIGS/VIS. LARGE HAIL
AND ERRATIC WIND GUSTS TO AROUND 50 KTS WILL BE POSSIBLE NORTH OF A
LINE FROM KCOS THE KLHX TO NORTH OF KSPD. THREAT DIMINISHES AFTER
00Z FOR THE KCOS AND KPUB TAF SITES. KALS WILL REMAIN DRY TODAY
WITH VFR CONDITIONS...THOUGH EXPECT A RETURN OF SOUTHWEST WINDS 15-
30 KTS IN THE AFTERNOON. -KT
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 523 AM MDT WED MAY 21 2014
NOT MANY ADJUSTMENTS NEEDED FOR THE LONGER TERM AS UNSETTLED
PATTERN IS STILL ANTICIPATED WITH LONGER TERM METEOROLOGICAL
ISSUES REMAINING POPS...SEVERE WEATHER THREAT AT TIMES WITH
INITIAL LONGER TERM FOCUS FOR SEVERE WEATHER FROM THURSDAY INTO
THURSDAY NIGHT...LOCALLY HEAVY RAINFALL AND ASSOCIATED BURN SCAR
FLOODING THREAT AND TEMPERATURES.
RECENT LONGER TERM FORECAST MODEL SOUNDINGS AND COMPUTER
SIMULATIONS CONTINUE TO SUGGEST THAT CLOSED UPPER LOW LOCATED
OVER SOUTHERN NEVADA AT 00Z FRIDAY WILL SHIFT INTO THE 4-CORNERS
REGION BY 00Z SUNDAY AND THEN SLOWLY MOVES ACROSS SOUTHERN
COLORADO INTO MONDAY MORNING BEFORE MOVING EAST OF THE FORECAST
DISTRICT BY MONDAY NIGHT/TUESDAY MORNING.
UNSETTLED METEOROLOGICAL CONDITIONS(PRIMARILY IN THE FORM OF
RAIN...HEAVY AT TIMES AS WELL AS STRONG TO SEVERE STORMS AT
TIMES) ARE ANTICIPATED FROM THURSDAY INTO MONDAY. AT THIS
TIME...IT APPEARS THAT THE HIGHEST POTENTIAL FOR SEVERE
THUNDERSTORMS(ESPECIALLY EASTERN SECTIONS) DURING THE LONGER
TERM SHOULD BE REALIZED FROM THURSDAY INTO THURSDAY
NIGHT...ESPECIALLY IF ENOUGH ADEQUATE ATMOSPHERIC MOISTURE
INTERACTS WITH SOMEWHAT FAVORABLE 0 TO 6 KM BULK SHEAR VALUES.
RECENT SPC 2ND DAY OUTLOOK(FOR THURSDAY) HAS A LARGE PORTION OF
EASTERN COLORADO COVERED WITH A SLIGHT RISK OF SEVERE
THUNDERSTORMS.
IN ADDITION...PRECIPITATION...HEAVY AT TIMES(WHICH WILL BE CAPABLE
OF PRODUCING FLOODING CONCERNS/ISSUES AT TIMES...ESPECIALLY OVER
THE AREA BURN SCARS)...IS ANTICIPATED AS THE UPPER SYSTEM IMPACTS
THE FORECAST DISTRICT FROM LATE THIS WEEK INTO EARLY NEXT WEEK. AS
ALWAYS...WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY.
IMPROVING METEOROLOGICAL CONDITIONS SHOULD THEN BY NOTED BY
TUESDAY AS THE CLOSED UPPER LOW IS PROJECTED TO MOVE EAST OF THE
FORECAST DISTRICT. TEMPERATURES ARE STILL EXPECTED TO RUN NEAR
LATE MAY CLIMATOLOGICAL AVERAGES DURING THE LONGER TERM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1129 AM MDT WED MAY 21 2014
MVFR STRATUS HAS ERODED OVER MUCH OF THE PLAINS AS OF 18Z...WITH
ISOLATED THUNDERSTORMS ALREADY DEVELOPING OVER THE MOUNTAINS WEST
OF KDEN. EXPECT ISOLATED TO SCATTERED TSRA OVER MUCH OF THE AREA
THIS AFTERNOON AND EVENING...WITH AREAS OF MVFR CIGS/VIS UNDER
SOME THE STRONGER STORMS. LARGE HAIL AND ERRATIC WIND GUSTS TO
AROUND 50 KTS WILL BE POSSIBLE NORTH OF A LINE FROM KCOS TO KLHX
TO KSPD. THREAT DIMINISHES AFTER 00Z FOR THE KCOS AND KPUB TAF
SITES. KALS WILL REMAIN DRY TODAY WITH VFR CONDITIONS...WITH
SOUTHWEST WINDS WINDS 15-30 KTS THIS AFTERNOON. MVFR STRATUS WILL
REDEVELOP AT KCOS AND KPUB 11Z-13Z AS MOIST AIR SLOSHES SOUTH ONCE
AGAIN...WITH SCATTERED TSRA MOST LOCATIONS THU AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ224.
&&
$$
UPDATE...PETERSEN
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1119 AM MDT WED MAY 21 2014
.UPDATE...
ISSUED AT 1111 AM MDT WED MAY 21 2014
CURRENT FORECAST/SEVERE THREAT LOOKS ON TRACK...WITH LATEST HRRR
RUNS SUGGESTING CONVECTIVE INITIATION BETWEEN 19Z-20Z. STILL
APPEARS BEST TORNADO/SUPERCELL THREAT WILL BE NORTH NEAR THE
DCVZ INTO NE CO...WITH MORE OF A WIND/HAIL THREAT FARTHER SOUTH
WHERE T/TD SPREADS WILL BE LARGER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM MDT WED MAY 21 2014
...SEVERE THUNDERSTORMS POSSIBLE NORTHERN PORTIONS OF THE SOUTHEAST
PLAINS...CRITICAL FIRE WEATHER CONDITIONS EXPECTED ACROSS THE SAN
LUIS VALLEY...
UPPER LOW WILL STALL OUT OVER NEVADA TODAY BEFORE DROPPING SOUTHWARD
INTO SOUTHERN CA LATER TONIGHT. SOUTHERLY FLOW AHEAD OF THE SYSTEM
TODAY WILL START TO SHIFT SOME MID/HIGH LEVEL MOISTURE INTO THE
WESTERN MTS TODAY...BUT BY IN LARGE...LOWER LEVELS WILL REMAIN QUITE
DRY. WITH SOUTH TO SOUTHWEST WINDS INCREASING AGAIN ACROSS THE
SOUTHWEST MTS AND SAN LUIS VALLEY...EXPECT A RETURN OF CRITICAL FIRE
WEATHER CONDITIONS FOR THE SAN LUIS VALLEY WHERE FUELS ARE
CRITICALLY DRY. RAPID RATES OF FIRE SPREAD WILL BE POSSIBLE WITH
ANY FIRE STARTS AND CURRENT RED FLAG WARNING STILL LOOKS GOOD.
THERE COULD BE SOME ISOLATED HIGH BASED THUNDERSTORMS ALONG THE
CONTDVD TODAY...BUT THEY WILL BE FEW AND FAR BETWEEN...AND WITH
INVERTED V SOUNDINGS...MORE LIKELY TO PRODUCE GUSTY WINDS THAN MUCH
IN THE WAY OF RAINFALL.
DIFFERENT STORY WILL EXIST TODAY FOR THE SOUTHEAST PLAINS. LOW LEVEL
MOISTURE HAS SPREAD BACK IN WITH CURRENT DEW POINTS IN THE 50S FOR
THE LOWER ARKANSAS RIVER...WITH UPPER 40S FOR CANON CITY...AND EVEN
WOODLAND PARK SEEING LOWER 40 DEW POINTS. SOUTHERN I-25 CORRIDOR IS
STILL QUITE DRY WITH KTAD DEW POINT AT 13 AS OF 09Z. BOUNDARY WILL
CONTINUE TO PUSH SLOWLY SOUTHWARD THIS MORNING WITH STRATUS
EXPANDING ACROSS SOUTHEAST CO IN LIGHT UPSLOPE REGIME ALONG THE
LOWER EASTERN SLOPES OF TELLER/EL PASO COUNTY...THE LOWER WET
MOUNTAINS...AND THE NORTHERN SLOPES OF THE RATON RIDGE. THIS SHOULD
BURN OFF DURING THE LATE MORNING WITH DEW POINTS STAYING IN THE
UPPER 40S/LOWER 50S THROUGH EARLY AFTERNOON ACROSS THE MAJORITY OF
THE SOUTHEAST PLAINS. VORT MAX ACROSS NEW MEXICO WILL MOVE IN THIS
AFTERNOON...AND DRIER AIR WILL BEGIN TO MIX NORTHWARD OFF THE RATON
RIDGE. MAIN FACTOR DETERMINING EXTENT OF SEVERE WEATHER POTENTIAL
WILL BE HOW QUICKLY THESE DEW POINTS MIX OUT. HRRR AND RAP13 DROPS
DEW POINTS INTO THE UPPER 30S FOR THE I-25 CORRIDOR WITH 40S FARTHER
EAST BY 21Z. NAM12 AND LOCAL 4KM WRF KEEPS DEW POINTS IN THE LOWER
50S AT 21Z NORTHEAST OF A LINE FROM KCOS...TO KLHX...TO KSPD. SO
CAPES COULD BE AS LOW AS 500 J/KG ALONG THE I-25 CORRIDOR TO AROUND
1500 J/KG ACROSS KIOWA...BENT...PROWERS COUNTIES IF THE RAP IS
CORRECT. OR THEY COULD BE AROUND 1500+ J/KG IF THE NAM12 IS
CORRECT. EITHER WAY...0-6KM SHEARS WILL BE RUNNING AROUND 40-50
KTS...OR EVEN A LITTLE BETTER IF LOW LEVEL WINDS STAY OUT OF THE
EAST...WHICH WOULD SUPPORT DEVELOPMENT OF SUPERCELL THUNDERSTORMS.
BEST CHANCES FOR SEVERE LOOK TO BE ACROSS NORTHERN SECTIONS OF THE
SOUTHEAST PLAINS...WHERE HIGHER DEW POINTS ARE MORE LIKELY TO STAY
IN THE LONGEST. INITIATION MAY OCCUR ALONG THE NORTHERN SLOPES OF
THE RATON MESA AROUND 1 PM...WITH THUNDERSTORMS SPREADING/DEVELOPING
NORTHWARD ACROSS THE SOUTHEAST PLAINS THROUGH THE AFTERNOON.
MAJORITY OF THE ACTIVITY MOVES OUT OF THE AREA BY 00Z AS VORT MAX
LIFTS NORTHWARD. LARGE HAIL AND DAMAGING WINDS WILL BE THE MOST
LIKELY SEVERE THREAT...ESPECIALLY TO THE NORTH OF THE ARKANSAS
RIVER. IF DEW POINTS CAN STAY HIGH ENOUGH...THUS...LCLS LOW
ENOUGH...THERE COULD BE ENOUGH LOW LEVEL HELICITY FOR AN ISOLATED
TORNADO. THIS WOULD BE MORE LIKELY TO OCCUR ALONG THE PALMER DIVIDE
AND KIOWA COUNTY...BUT THREAT FOR THIS APPEARS ON THE LOWER SIDE OF
THE SPECTRUM AT THIS POINT. POTENTIAL FOR DAMAGING WIND GUSTS WILL
EXTEND FARTHER SOUTHWARD ACROSS THE SOUTHEAST PLAINS THAN HAIL
THREAT DUE TO HIGHER AVAILABLE DOWNDRAFT CAPE. WILL LIKELY PLAY THE
SEVERE THREAT AREA NORTHEAST OF A LINE FROM COLORADO SPRINGS...TO LA
JUNTA...TO TWO BUTTES.
FINAL CONCERN IS FOR POTENTIAL FOR HEAVY RAINFALL ON THE BURN SCARS
THIS AFTERNOON...PARTICULARLY ACROSS WALDO AND BLACK FOREST. WINDOW
FOR GREATEST THREAT WILL BE FROM 2 PM TO 6 PM...PROBABLY CENTERED
MORE IN THE 3 TO 5 PM RANGE FOR WALDO. AGAIN...STRENGTH OF
UPDRAFTS/POTENTIAL RAINFALL EFFICIENCIES WILL DEPEND ON HOW MUCH LOW
LEVEL MOISTURE STAYS IN. HUNCH IS THAT HIGHER TERRAIN WILL MIX OUT
AT LEAST SOME OF THE LOW LEVEL MOISTURE AND LCLS WILL BE UP AROUND
11-12KFT MSL...WHICH WILL ALLOW FOR SOME EVAPORATION BELOW CLOUD
BASE. ALTHOUGH THREAT FOR FLASH FLOOD PRODUCING RAINFALL IS THERE
TODAY...THINK THE THREAT IS BELOW A 40 PERCENT PROBABILITY. MORE
LIKELY SCENARIO IS FOR SOME RAINFALL AMOUNTS GENERALLY IN THE
.10 TO .40 RANGE...WHICH COULD MEAN SOME FLOOD ADVISORY RAINFALL
CAUSING MINOR RUN OFF FOR THE WALDO BURN SCAR. MAJORITY OF THE HIGH
RES MODELS SUGGEST THE LESSER IMPACT SCENARIO...BUT SITUATION WILL
REQUIRE CLOSE MONITORING THROUGH THE AFTERNOON AND EARLY EVENING
HOURS.
THUNDERSTORMS WILL COME TO AN END DURING THE EVENING FOR MOST
AREAS...WITH ANOTHER INTRUSION OF STRATUS TOWARDS MORNING ACROSS
NORTHERN PORTIONS OF THE SOUTHEAST PLAINS. -KT
.AVIATION... MVFR CIGS WILL CONTINUE TO EXPAND ACROSS THE SOUTHEAST
PLAINS THROUGH MORNING...WITH SOME POCKETS OF IFR CIGS ACROSS THE
PIKES PEAK REGION AND ALONG THE LOWER EASTERN SLOPES OF THE
SOUTHEAST MOUNTAINS. COULD EVEN SEE SOME PATCHY FOG. STRATUS
SHOULD ERODE BY 17-18Z FOR MOST AREAS WITH ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING DURING THE EARLY AFTERNOON ACROSS THE
SOUTHEAST MOUNTAINS AND NORTHERN SLOPES OF THE RATON RIDGE. THESE
WILL BE CAPABLE OF PRODUCING VFR TO LOCAL MVFR CIGS/VIS. LARGE HAIL
AND ERRATIC WIND GUSTS TO AROUND 50 KTS WILL BE POSSIBLE NORTH OF A
LINE FROM KCOS THE KLHX TO NORTH OF KSPD. THREAT DIMINISHES AFTER
00Z FOR THE KCOS AND KPUB TAF SITES. KALS WILL REMAIN DRY TODAY
WITH VFR CONDITIONS...THOUGH EXPECT A RETURN OF SOUTHWEST WINDS 15-
30 KTS IN THE AFTERNOON. -KT
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 523 AM MDT WED MAY 21 2014
NOT MANY ADJUSTMENTS NEEDED FOR THE LONGER TERM AS UNSETTLED
PATTERN IS STILL ANTICIPATED WITH LONGER TERM METEOROLOGICAL
ISSUES REMAINING POPS...SEVERE WEATHER THREAT AT TIMES WITH
INITIAL LONGER TERM FOCUS FOR SEVERE WEATHER FROM THURSDAY INTO
THURSDAY NIGHT...LOCALLY HEAVY RAINFALL AND ASSOCIATED BURN SCAR
FLOODING THREAT AND TEMPERATURES.
RECENT LONGER TERM FORECAST MODEL SOUNDINGS AND COMPUTER
SIMULATIONS CONTINUE TO SUGGEST THAT CLOSED UPPER LOW LOCATED
OVER SOUTHERN NEVADA AT 00Z FRIDAY WILL SHIFT INTO THE 4-CORNERS
REGION BY 00Z SUNDAY AND THEN SLOWLY MOVES ACROSS SOUTHERN
COLORADO INTO MONDAY MORNING BEFORE MOVING EAST OF THE FORECAST
DISTRICT BY MONDAY NIGHT/TUESDAY MORNING.
UNSETTLED METEOROLOGICAL CONDITIONS(PRIMARILY IN THE FORM OF
RAIN...HEAVY AT TIMES AS WELL AS STRONG TO SEVERE STORMS AT
TIMES) ARE ANTICIPATED FROM THURSDAY INTO MONDAY. AT THIS
TIME...IT APPEARS THAT THE HIGHEST POTENTIAL FOR SEVERE
THUNDERSTORMS(ESPECIALLY EASTERN SECTIONS) DURING THE LONGER
TERM SHOULD BE REALIZED FROM THURSDAY INTO THURSDAY
NIGHT...ESPECIALLY IF ENOUGH ADEQUATE ATMOSPHERIC MOISTURE
INTERACTS WITH SOMEWHAT FAVORABLE 0 TO 6 KM BULK SHEAR VALUES.
RECENT SPC 2ND DAY OUTLOOK(FOR THURSDAY) HAS A LARGE PORTION OF
EASTERN COLORADO COVERED WITH A SLIGHT RISK OF SEVERE
THUNDERSTORMS.
IN ADDITION...PRECIPITATION...HEAVY AT TIMES(WHICH WILL BE CAPABLE
OF PRODUCING FLOODING CONCERNS/ISSUES AT TIMES...ESPECIALLY OVER
THE AREA BURN SCARS)...IS ANTICIPATED AS THE UPPER SYSTEM IMPACTS
THE FORECAST DISTRICT FROM LATE THIS WEEK INTO EARLY NEXT WEEK. AS
ALWAYS...WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY.
IMPROVING METEOROLOGICAL CONDITIONS SHOULD THEN BY NOTED BY
TUESDAY AS THE CLOSED UPPER LOW IS PROJECTED TO MOVE EAST OF THE
FORECAST DISTRICT. TEMPERATURES ARE STILL EXPECTED TO RUN NEAR
LATE MAY CLIMATOLOGICAL AVERAGES DURING THE LONGER TERM.
&&
.AVIATION... MVFR CIGS WILL CONTINUE TO EXPAND ACROSS THE SOUTHEAST
PLAINS THROUGH MORNING...WITH SOME POCKETS OF IFR CIGS ACROSS THE
PIKES PEAK REGION AND ALONG THE LOWER EASTERN SLOPES OF THE
SOUTHEAST MOUNTAINS. COULD EVEN SEE SOME PATCHY FOG. STRATUS
SHOULD ERODE BY 17-18Z FOR MOST AREAS WITH ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING DURING THE EARLY AFTERNOON ACROSS THE
SOUTHEAST MOUNTAINS AND NORTHERN SLOPES OF THE RATON RIDGE. THESE
WILL BE CAPABLE OF PRODUCING VFR TO LOCAL MVFR CIGS/VIS. LARGE HAIL
AND ERRATIC WIND GUSTS TO AROUND 50 KTS WILL BE POSSIBLE NORTH OF A
LINE FROM KCOS THE KLHX TO NORTH OF KSPD. THREAT DIMINISHES AFTER
00Z FOR THE KCOS AND KPUB TAF SITES. KALS WILL REMAIN DRY TODAY
WITH VFR CONDITIONS...THOUGH EXPECT A RETURN OF SOUTHWEST WINDS 15-
30 KTS IN THE AFTERNOON. -KT
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 523 AM MDT WED MAY 21 2014
NOT MANY ADJUSTMENTS NEEDED FOR THE LONGER TERM AS UNSETTLED
PATTERN IS STILL ANTICIPATED WITH LONGER TERM METEOROLOGICAL
ISSUES REMAINING POPS...SEVERE WEATHER THREAT AT TIMES WITH
INITIAL LONGER TERM FOCUS FOR SEVERE WEATHER FROM THURSDAY INTO
THURSDAY NIGHT...LOCALLY HEAVY RAINFALL AND ASSOCIATED BURN SCAR
FLOODING THREAT AND TEMPERATURES.
RECENT LONGER TERM FORECAST MODEL SOUNDINGS AND COMPUTER
SIMULATIONS CONTINUE TO SUGGEST THAT CLOSED UPPER LOW LOCATED
OVER SOUTHERN NEVADA AT 00Z FRIDAY WILL SHIFT INTO THE 4-CORNERS
REGION BY 00Z SUNDAY AND THEN SLOWLY MOVES ACROSS SOUTHERN
COLORADO INTO MONDAY MORNING BEFORE MOVING EAST OF THE FORECAST
DISTRICT BY MONDAY NIGHT/TUESDAY MORNING.
UNSETTLED METEOROLOGICAL CONDITIONS(PRIMARILY IN THE FORM OF
RAIN...HEAVY AT TIMES AS WELL AS STRONG TO SEVERE STORMS AT
TIMES) ARE ANTICIPATED FROM THURSDAY INTO MONDAY. AT THIS
TIME...IT APPEARS THAT THE HIGHEST POTENTIAL FOR SEVERE
THUNDERSTORMS(ESPECIALLY EASTERN SECTIONS) DURING THE LONGER
TERM SHOULD BE REALIZED FROM THURSDAY INTO THURSDAY
NIGHT...ESPECIALLY IF ENOUGH ADEQUATE ATMOSPHERIC MOISTURE
INTERACTS WITH SOMEWHAT FAVORABLE 0 TO 6 KM BULK SHEAR VALUES.
RECENT SPC 2ND DAY OUTLOOK(FOR THURSDAY) HAS A LARGE PORTION OF
EASTERN COLORADO COVERED WITH A SLIGHT RISK OF SEVERE
THUNDERSTORMS.
IN ADDITION...PRECIPITATION...HEAVY AT TIMES(WHICH WILL BE CAPABLE
OF PRODUCING FLOODING CONCERNS/ISSUES AT TIMES...ESPECIALLY OVER
THE AREA BURN SCARS)...IS ANTICIPATED AS THE UPPER SYSTEM IMPACTS
THE FORECAST DISTRICT FROM LATE THIS WEEK INTO EARLY NEXT WEEK. AS
ALWAYS...WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY.
IMPROVING METEOROLOGICAL CONDITIONS SHOULD THEN BY NOTED BY
TUESDAY AS THE CLOSED UPPER LOW IS PROJECTED TO MOVE EAST OF THE
FORECAST DISTRICT. TEMPERATURES ARE STILL EXPECTED TO RUN NEAR
LATE MAY CLIMATOLOGICAL AVERAGES DURING THE LONGER TERM.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ224.
&&
$$
UPDATE...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
524 AM MDT WED MAY 21 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM MDT WED MAY 21 2014
...SEVERE THUNDERSTORMS POSSIBLE NORTHERN PORTIONS OF THE SOUTHEAST
PLAINS...CRITICAL FIRE WEATHER CONDITIONS EXPECTED ACROSS THE SAN
LUIS VALLEY...
UPPER LOW WILL STALL OUT OVER NEVADA TODAY BEFORE DROPPING SOUTHWARD
INTO SOUTHERN CA LATER TONIGHT. SOUTHERLY FLOW AHEAD OF THE SYSTEM
TODAY WILL START TO SHIFT SOME MID/HIGH LEVEL MOISTURE INTO THE
WESTERN MTS TODAY...BUT BY IN LARGE...LOWER LEVELS WILL REMAIN QUITE
DRY. WITH SOUTH TO SOUTHWEST WINDS INCREASING AGAIN ACROSS THE
SOUTHWEST MTS AND SAN LUIS VALLEY...EXPECT A RETURN OF CRITICAL FIRE
WEATHER CONDITIONS FOR THE SAN LUIS VALLEY WHERE FUELS ARE
CRITICALLY DRY. RAPID RATES OF FIRE SPREAD WILL BE POSSIBLE WITH
ANY FIRE STARTS AND CURRENT RED FLAG WARNING STILL LOOKS GOOD.
THERE COULD BE SOME ISOLATED HIGH BASED THUNDERSTORMS ALONG THE
CONTDVD TODAY...BUT THEY WILL BE FEW AND FAR BETWEEN...AND WITH
INVERTED V SOUNDINGS...MORE LIKELY TO PRODUCE GUSTY WINDS THAN MUCH
IN THE WAY OF RAINFALL.
DIFFERENT STORY WILL EXIST TODAY FOR THE SOUTHEAST PLAINS. LOW LEVEL
MOISTURE HAS SPREAD BACK IN WITH CURRENT DEW POINTS IN THE 50S FOR
THE LOWER ARKANSAS RIVER...WITH UPPER 40S FOR CANON CITY...AND EVEN
WOODLAND PARK SEEING LOWER 40 DEW POINTS. SOUTHERN I-25 CORRIDOR IS
STILL QUITE DRY WITH KTAD DEW POINT AT 13 AS OF 09Z. BOUNDARY WILL
CONTINUE TO PUSH SLOWLY SOUTHWARD THIS MORNING WITH STRATUS
EXPANDING ACROSS SOUTHEAST CO IN LIGHT UPSLOPE REGIME ALONG THE
LOWER EASTERN SLOPES OF TELLER/EL PASO COUNTY...THE LOWER WET
MOUNTAINS...AND THE NORTHERN SLOPES OF THE RATON RIDGE. THIS SHOULD
BURN OFF DURING THE LATE MORNING WITH DEW POINTS STAYING IN THE
UPPER 40S/LOWER 50S THROUGH EARLY AFTERNOON ACROSS THE MAJORITY OF
THE SOUTHEAST PLAINS. VORT MAX ACROSS NEW MEXICO WILL MOVE IN THIS
AFTERNOON...AND DRIER AIR WILL BEGIN TO MIX NORTHWARD OFF THE RATON
RIDGE. MAIN FACTOR DETERMINING EXTENT OF SEVERE WEATHER POTENTIAL
WILL BE HOW QUICKLY THESE DEW POINTS MIX OUT. HRRR AND RAP13 DROPS
DEW POINTS INTO THE UPPER 30S FOR THE I-25 CORRIDOR WITH 40S FARTHER
EAST BY 21Z. NAM12 AND LOCAL 4KM WRF KEEPS DEW POINTS IN THE LOWER
50S AT 21Z NORTHEAST OF A LINE FROM KCOS...TO KLHX...TO KSPD. SO
CAPES COULD BE AS LOW AS 500 J/KG ALONG THE I-25 CORRIDOR TO AROUND
1500 J/KG ACROSS KIOWA...BENT...PROWERS COUNTIES IF THE RAP IS
CORRECT. OR THEY COULD BE AROUND 1500+ J/KG IF THE NAM12 IS
CORRECT. EITHER WAY...0-6KM SHEARS WILL BE RUNNING AROUND 40-50
KTS...OR EVEN A LITTLE BETTER IF LOW LEVEL WINDS STAY OUT OF THE
EAST...WHICH WOULD SUPPORT DEVELOPMENT OF SUPERCELL THUNDERSTORMS.
BEST CHANCES FOR SEVERE LOOK TO BE ACROSS NORTHERN SECTIONS OF THE
SOUTHEAST PLAINS...WHERE HIGHER DEW POINTS ARE MORE LIKELY TO STAY
IN THE LONGEST. INITIATION MAY OCCUR ALONG THE NORTHERN SLOPES OF
THE RATON MESA AROUND 1 PM...WITH THUNDERSTORMS SPREADING/DEVELOPING
NORTHWARD ACROSS THE SOUTHEAST PLAINS THROUGH THE AFTERNOON.
MAJORITY OF THE ACTIVITY MOVES OUT OF THE AREA BY 00Z AS VORT MAX
LIFTS NORTHWARD. LARGE HAIL AND DAMAGING WINDS WILL BE THE MOST
LIKELY SEVERE THREAT...ESPECIALLY TO THE NORTH OF THE ARKANSAS
RIVER. IF DEW POINTS CAN STAY HIGH ENOUGH...THUS...LCLS LOW
ENOUGH...THERE COULD BE ENOUGH LOW LEVEL HELICITY FOR AN ISOLATED
TORNADO. THIS WOULD BE MORE LIKELY TO OCCUR ALONG THE PALMER DIVIDE
AND KIOWA COUNTY...BUT THREAT FOR THIS APPEARS ON THE LOWER SIDE OF
THE SPECTRUM AT THIS POINT. POTENTIAL FOR DAMAGING WIND GUSTS WILL
EXTEND FARTHER SOUTHWARD ACROSS THE SOUTHEAST PLAINS THAN HAIL
THREAT DUE TO HIGHER AVAILABLE DOWNDRAFT CAPE. WILL LIKELY PLAY THE
SEVERE THREAT AREA NORTHEAST OF A LINE FROM COLORADO SPRINGS...TO LA
JUNTA...TO TWO BUTTES.
FINAL CONCERN IS FOR POTENTIAL FOR HEAVY RAINFALL ON THE BURN SCARS
THIS AFTERNOON...PARTICULARLY ACROSS WALDO AND BLACK FOREST. WINDOW
FOR GREATEST THREAT WILL BE FROM 2 PM TO 6 PM...PROBABLY CENTERED
MORE IN THE 3 TO 5 PM RANGE FOR WALDO. AGAIN...STRENGTH OF
UPDRAFTS/POTENTIAL RAINFALL EFFICIENCIES WILL DEPEND ON HOW MUCH LOW
LEVEL MOISTURE STAYS IN. HUNCH IS THAT HIGHER TERRAIN WILL MIX OUT
AT LEAST SOME OF THE LOW LEVEL MOISTURE AND LCLS WILL BE UP AROUND
11-12KFT MSL...WHICH WILL ALLOW FOR SOME EVAPORATION BELOW CLOUD
BASE. ALTHOUGH THREAT FOR FLASH FLOOD PRODUCING RAINFALL IS THERE
TODAY...THINK THE THREAT IS BELOW A 40 PERCENT PROBABILITY. MORE
LIKELY SCENARIO IS FOR SOME RAINFALL AMOUNTS GENERALLY IN THE
.10 TO .40 RANGE...WHICH COULD MEAN SOME FLOOD ADVISORY RAINFALL
CAUSING MINOR RUN OFF FOR THE WALDO BURN SCAR. MAJORITY OF THE HIGH
RES MODELS SUGGEST THE LESSER IMPACT SCENARIO...BUT SITUATION WILL
REQUIRE CLOSE MONITORING THROUGH THE AFTERNOON AND EARLY EVENING
HOURS.
THUNDERSTORMS WILL COME TO AN END DURING THE EVENING FOR MOST
AREAS...WITH ANOTHER INTRUSION OF STRATUS TOWARDS MORNING ACROSS
NORTHERN PORTIONS OF THE SOUTHEAST PLAINS. -KT
.AVIATION... MVFR CIGS WILL CONTINUE TO EXPAND ACROSS THE SOUTHEAST
PLAINS THROUGH MORNING...WITH SOME POCKETS OF IFR CIGS ACROSS THE
PIKES PEAK REGION AND ALONG THE LOWER EASTERN SLOPES OF THE
SOUTHEAST MOUNTAINS. COULD EVEN SEE SOME PATCHY FOG. STRATUS
SHOULD ERODE BY 17-18Z FOR MOST AREAS WITH ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING DURING THE EARLY AFTERNOON ACROSS THE
SOUTHEAST MOUNTAINS AND NORTHERN SLOPES OF THE RATON RIDGE. THESE
WILL BE CAPABLE OF PRODUCING VFR TO LOCAL MVFR CIGS/VIS. LARGE HAIL
AND ERRATIC WIND GUSTS TO AROUND 50 KTS WILL BE POSSIBLE NORTH OF A
LINE FROM KCOS THE KLHX TO NORTH OF KSPD. THREAT DIMINISHES AFTER
00Z FOR THE KCOS AND KPUB TAF SITES. KALS WILL REMAIN DRY TODAY
WITH VFR CONDITIONS...THOUGH EXPECT A RETURN OF SOUTHWEST WINDS 15-
30 KTS IN THE AFTERNOON. -KT
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 523 AM MDT WED MAY 21 2014
NOT MANY ADJUSTMENTS NEEDED FOR THE LONGER TERM AS UNSETTLED
PATTERN IS STILL ANTICIPATED WITH LONGER TERM METEOROLOGICAL
ISSUES REMAINING POPS...SEVERE WEATHER THREAT AT TIMES WITH
INITIAL LONGER TERM FOCUS FOR SEVERE WEATHER FROM THURSDAY INTO
THURSDAY NIGHT...LOCALLY HEAVY RAINFALL AND ASSOCIATED BURN SCAR
FLOODING THREAT AND TEMPERATURES.
RECENT LONGER TERM FORECAST MODEL SOUNDINGS AND COMPUTER
SIMULATIONS CONTINUE TO SUGGEST THAT CLOSED UPPER LOW LOCATED
OVER SOUTHERN NEVADA AT 00Z FRIDAY WILL SHIFT INTO THE 4-CORNERS
REGION BY 00Z SUNDAY AND THEN SLOWLY MOVES ACROSS SOUTHERN
COLORADO INTO MONDAY MORNING BEFORE MOVING EAST OF THE FORECAST
DISTRICT BY MONDAY NIGHT/TUESDAY MORNING.
UNSETTLED METEOROLOGICAL CONDITIONS(PRIMARILY IN THE FORM OF
RAIN...HEAVY AT TIMES AS WELL AS STRONG TO SEVERE STORMS AT
TIMES) ARE ANTICIPATED FROM THURSDAY INTO MONDAY. AT THIS
TIME...IT APPEARS THAT THE HIGHEST POTENTIAL FOR SEVERE
THUNDERSTORMS(ESPECIALLY EASTERN SECTIONS) DURING THE LONGER
TERM SHOULD BE REALIZED FROM THURSDAY INTO THURSDAY
NIGHT...ESPECIALLY IF ENOUGH ADEQUATE ATMOSPHERIC MOISTURE
INTERACTS WITH SOMEWHAT FAVORABLE 0 TO 6 KM BULK SHEAR VALUES.
RECENT SPC 2ND DAY OUTLOOK(FOR THURSDAY) HAS A LARGE PORTION OF
EASTERN COLORADO COVERED WITH A SLIGHT RISK OF SEVERE
THUNDERSTORMS.
IN ADDITION...PRECIPITATION...HEAVY AT TIMES(WHICH WILL BE CAPABLE
OF PRODUCING FLOODING CONCERNS/ISSUES AT TIMES...ESPECIALLY OVER
THE AREA BURN SCARS)...IS ANTICIPATED AS THE UPPER SYSTEM IMPACTS
THE FORECAST DISTRICT FROM LATE THIS WEEK INTO EARLY NEXT WEEK. AS
ALWAYS...WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY.
IMPROVING METEOROLOGICAL CONDITIONS SHOULD THEN BY NOTED BY
TUESDAY AS THE CLOSED UPPER LOW IS PROJECTED TO MOVE EAST OF THE
FORECAST DISTRICT. TEMPERATURES ARE STILL EXPECTED TO RUN NEAR
LATE MAY CLIMATOLOGICAL AVERAGES DURING THE LONGER TERM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 523 AM MDT WED MAY 21 2014
MVFR CIGS WILL CONTINUE TO EXPAND ACROSS THE SOUTHEAST
PLAINS THROUGH MORNING...WITH SOME POCKETS OF IFR CIGS ACROSS THE
PIKES PEAK REGION AND ALONG THE LOWER EASTERN SLOPES OF THE
SOUTHEAST MOUNTAINS. COULD EVEN SEE SOME PATCHY FOG. STRATUS
SHOULD ERODE BY 17-18Z FOR MOST AREAS WITH ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING DURING THE EARLY AFTERNOON ACROSS THE
SOUTHEAST MOUNTAINS AND NORTHERN SLOPES OF THE RATON RIDGE. THESE
WILL BE CAPABLE OF PRODUCING VFR TO LOCAL MVFR CIGS/VIS. LARGE HAIL
AND ERRATIC WIND GUSTS TO AROUND 50 KTS WILL BE POSSIBLE NORTH OF A
LINE FROM KCOS THE KLHX TO NORTH OF KSPD. THREAT DIMINISHES AFTER
00Z FOR THE KCOS AND KPUB TAF SITES. KALS WILL REMAIN DRY TODAY
WITH VFR CONDITIONS...THOUGH EXPECT A RETURN OF SOUTHWEST WINDS 15-
30 KTS IN THE AFTERNOON. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON TODAY TO 8 PM MDT THIS EVENING FOR
COZ224.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
458 AM MDT WED MAY 21 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 458 AM MDT WED MAY 21 2014
...SEVERE THUNDERSTORMS POSSIBLE NORTHERN PORTIONS OF THE SOUTHEAST
PLAINS...CRITICAL FIRE WEATHER CONDITIONS EXPECTED ACROSS THE SAN
LUIS VALLEY...
UPPER LOW WILL STALL OUT OVER NEVADA TODAY BEFORE DROPPING SOUTHWARD
INTO SOUTHERN CA LATER TONIGHT. SOUTHERLY FLOW AHEAD OF THE SYSTEM
TODAY WILL START TO SHIFT SOME MID/HIGH LEVEL MOISTURE INTO THE
WESTERN MTS TODAY...BUT BY IN LARGE...LOWER LEVELS WILL REMAIN QUITE
DRY. WITH SOUTH TO SOUTHWEST WINDS INCREASING AGAIN ACROSS THE
SOUTHWEST MTS AND SAN LUIS VALLEY...EXPECT A RETURN OF CRITICAL FIRE
WEATHER CONDITIONS FOR THE SAN LUIS VALLEY WHERE FUELS ARE
CRITICALLY DRY. RAPID RATES OF FIRE SPREAD WILL BE POSSIBLE WITH
ANY FIRE STARTS AND CURRENT RED FLAG WARNING STILL LOOKS GOOD.
THERE COULD BE SOME ISOLATED HIGH BASED THUNDERSTORMS ALONG THE
CONTDVD TODAY...BUT THEY WILL BE FEW AND FAR BETWEEN...AND WITH
INVERTED V SOUNDINGS...MORE LIKELY TO PRODUCE GUSTY WINDS THAN MUCH
IN THE WAY OF RAINFALL.
DIFFERENT STORY WILL EXIST TODAY FOR THE SOUTHEAST PLAINS. LOW LEVEL
MOISTURE HAS SPREAD BACK IN WITH CURRENT DEW POINTS IN THE 50S FOR
THE LOWER ARKANSAS RIVER...WITH UPPER 40S FOR CANON CITY...AND EVEN
WOODLAND PARK SEEING LOWER 40 DEW POINTS. SOUTHERN I-25 CORRIDOR IS
STILL QUITE DRY WITH KTAD DEW POINT AT 13 AS OF 09Z. BOUNDARY WILL
CONTINUE TO PUSH SLOWLY SOUTHWARD THIS MORNING WITH STRATUS
EXPANDING ACROSS SOUTHEAST CO IN LIGHT UPSLOPE REGIME ALONG THE
LOWER EASTERN SLOPES OF TELLER/EL PASO COUNTY...THE LOWER WET
MOUNTAINS...AND THE NORTHERN SLOPES OF THE RATON RIDGE. THIS SHOULD
BURN OFF DURING THE LATE MORNING WITH DEW POINTS STAYING IN THE
UPPER 40S/LOWER 50S THROUGH EARLY AFTERNOON ACROSS THE MAJORITY OF
THE SOUTHEAST PLAINS. VORT MAX ACROSS NEW MEXICO WILL MOVE IN THIS
AFTERNOON...AND DRIER AIR WILL BEGIN TO MIX NORTHWARD OFF THE RATON
RIDGE. MAIN FACTOR DETERMINING EXTENT OF SEVERE WEATHER POTENTIAL
WILL BE HOW QUICKLY THESE DEW POINTS MIX OUT. HRRR AND RAP13 DROPS
DEW POINTS INTO THE UPPER 30S FOR THE I-25 CORRIDOR WITH 40S FARTHER
EAST BY 21Z. NAM12 AND LOCAL 4KM WRF KEEPS DEW POINTS IN THE LOWER
50S AT 21Z NORTHEAST OF A LINE FROM KCOS...TO KLHX...TO KSPD. SO
CAPES COULD BE AS LOW AS 500 J/KG ALONG THE I-25 CORRIDOR TO AROUND
1500 J/KG ACROSS KIOWA...BENT...PROWERS COUNTIES IF THE RAP IS
CORRECT. OR THEY COULD BE AROUND 1500+ J/KG IF THE NAM12 IS
CORRECT. EITHER WAY...0-6KM SHEARS WILL BE RUNNING AROUND 40-50
KTS...OR EVEN A LITTLE BETTER IF LOW LEVEL WINDS STAY OUT OF THE
EAST...WHICH WOULD SUPPORT DEVELOPMENT OF SUPERCELL THUNDERSTORMS.
BEST CHANCES FOR SEVERE LOOK TO BE ACROSS NORTHERN SECTIONS OF THE
SOUTHEAST PLAINS...WHERE HIGHER DEW POINTS ARE MORE LIKELY TO STAY
IN THE LONGEST. INITIATION MAY OCCUR ALONG THE NORTHERN SLOPES OF
THE RATON MESA AROUND 1 PM...WITH THUNDERSTORMS SPREADING/DEVELOPING
NORTHWARD ACROSS THE SOUTHEAST PLAINS THROUGH THE AFTERNOON.
MAJORITY OF THE ACTIVITY MOVES OUT OF THE AREA BY 00Z AS VORT MAX
LIFTS NORTHWARD. LARGE HAIL AND DAMAGING WINDS WILL BE THE MOST
LIKELY SEVERE THREAT...ESPECIALLY TO THE NORTH OF THE ARKANSAS
RIVER. IF DEW POINTS CAN STAY HIGH ENOUGH...THUS...LCLS LOW
ENOUGH...THERE COULD BE ENOUGH LOW LEVEL HELICITY FOR AN ISOLATED
TORNADO. THIS WOULD BE MORE LIKELY TO OCCUR ALONG THE PALMER DIVIDE
AND KIOWA COUNTY...BUT THREAT FOR THIS APPEARS ON THE LOWER SIDE OF
THE SPECTRUM AT THIS POINT. POTENTIAL FOR DAMAGING WIND GUSTS WILL
EXTEND FARTHER SOUTHWARD ACROSS THE SOUTHEAST PLAINS THAN HAIL
THREAT DUE TO HIGHER AVAILABLE DOWNDRAFT CAPE. WILL LIKELY PLAY THE
SEVERE THREAT AREA NORTHEAST OF A LINE FROM COLORADO SPRINGS...TO LA
JUNTA...TO TWO BUTTES.
FINAL CONCERN IS FOR POTENTIAL FOR HEAVY RAINFALL ON THE BURN SCARS
THIS AFTERNOON...PARTICULARLY ACROSS WALDO AND BLACK FOREST. WINDOW
FOR GREATEST THREAT WILL BE FROM 2 PM TO 6 PM...PROBABLY CENTERED
MORE IN THE 3 TO 5 PM RANGE FOR WALDO. AGAIN...STRENGTH OF
UPDRAFTS/POTENTIAL RAINFALL EFFICIENCIES WILL DEPEND ON HOW MUCH LOW
LEVEL MOISTURE STAYS IN. HUNCH IS THAT HIGHER TERRAIN WILL MIX OUT
AT LEAST SOME OF THE LOW LEVEL MOISTURE AND LCLS WILL BE UP AROUND
11-12KFT MSL...WHICH WILL ALLOW FOR SOME EVAPORATION BELOW CLOUD
BASE. ALTHOUGH THREAT FOR FLASH FLOOD PRODUCING RAINFALL IS THERE
TODAY...THINK THE THREAT IS BELOW A 40 PERCENT PROBABILITY. MORE
LIKELY SCENARIO IS FOR SOME RAINFALL AMOUNTS GENERALLY IN THE
.10 TO .40 RANGE...WHICH COULD MEAN SOME FLOOD ADVISORY RAINFALL
CAUSING MINOR RUN OFF FOR THE WALDO BURN SCAR. MAJORITY OF THE HIGH
RES MODELS SUGGEST THE LESSER IMPACT SCENARIO...BUT SITUATION WILL
REQUIRE CLOSE MONITORING THROUGH THE AFTERNOON AND EARLY EVENING
HOURS.
THUNDERSTORMS WILL COME TO AN END DURING THE EVENING FOR MOST
AREAS...WITH ANOTHER INTRUSION OF STRATUS TOWARDS MORNING ACROSS
NORTHERN PORTIONS OF THE SOUTHEAST PLAINS. -KT
.AVIATION... MVFR CIGS WILL CONTINUE TO EXPAND ACROSS THE SOUTHEAST
PLAINS THROUGH MORNING...WITH SOME POCKETS OF IFR CIGS ACROSS THE
PIKES PEAK REGION AND ALONG THE LOWER EASTERN SLOPES OF THE
SOUTHEAST MOUNTAINS. COULD EVEN SEE SOME PATCHY FOG. STRATUS
SHOULD ERODE BY 17-18Z FOR MOST AREAS WITH ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING DURING THE EARLY AFTERNOON ACROSS THE
SOUTHEAST MOUNTAINS AND NORTHERN SLOPES OF THE RATON RIDGE. THESE
WILL BE CAPABLE OF PRODUCING VFR TO LOCAL MVFR CIGS/VIS. LARGE HAIL
AND ERRATIC WIND GUSTS TO AROUND 50 KTS WILL BE POSSIBLE NORTH OF A
LINE FROM KCOS THE KLHX TO NORTH OF KSPD. THREAT DIMINISHES AFTER
00Z FOR THE KCOS AND KPUB TAF SITES. KALS WILL REMAIN DRY TODAY
WITH VFR CONDITIONS...THOUGH EXPECT A RETURN OF SOUTHWEST WINDS 15-
30 KTS IN THE AFTERNOON. -KT
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 458 AM MDT WED MAY 21 2014
NOT MANY ADJUSTMENTS NEEDED FOR THE LONGER TERM AS UNSETTLED
PATTERN IS STILL ANTICIPATED WITH LONGER TERM ISSUES REMAINING
POPS...SEVERE WEATHER THREAT AT TIMES WITH INITIAL LONGER TERM
FOCUS FOR SEVERE WEATHER FROM THURSDAY INTO THURSDAY
NIGHT...LOCALLY HEAVY RAINFALL AND ASSOCIATED BURN SCAR FLOODING
THREAT AND POPS.
RECENT LONGER TERM FORECAST MODEL SOUNDINGS AND COMPUTER
SIMULATIONS CONTINUE TO SUGGEST THAT CLOSED UPPER LOW LOCATED
OVER SOUTHERN NEVADA AT 00Z FRIDAY WILL SHIFT INTO THE 4-CORNERS
REGION BY 00Z SUNDAY AND THEN SLOWLY MOVES ACROSS SOUTHERN
COLORADO INTO MONDAY MORNING BEFORE MOVING EAST OF THE FORECAST
DISTRICT BY MONDAY EVENING.
UNSETTLED METEOROLOGICAL CONDITIONS(PRIMARILY IN THE FORM OF
RAIN...HEAVY AT TIMES AS WELL AS STRONG TO SEVERE STORMS AT
TIMES) ARE ANTICIPATED FROM THURSDAY INTO MONDAY. AT THIS
TIME...IT APPEARS THAT THE HIGHEST POTENTIAL FOR SEVERE
THUNDERSTORMS(ESPECIALLY EASTERN SECTIONS) DURING THE LONGER
TERM SHOULD BE REALIZED FROM THURSDAY INTO THURSDAY
NIGHT...ESPECIALLY IF ENOUGH ADEQUATE ATMOSPHERIC MOISTURE
INTERACTS WITH SOMEWHAT FAVORABLE 0 TO 6 KM BULK SHEAR VALUES.
RECENT SPC 2ND DAY OUTLOOK(FOR THURSDAY) HAS A LARGE PORTION OF
EASTERN COLORADO COVERED WITH A SLIGHT RISK OF SEVERE
THUNDERSTORMS.
IN ADDITION...PRECIPITATION...HEAVY AT TIMES(WHICH WILL BE CAPABLE
OF PRODUCING FLOODING CONCERNS/ISSUES AT TIMES...ESPECIALLY OVER
AREA BURN SCARS)...IS ANTICIPATED AS THE UPPER SYSTEM IMPACTS THE
FORECAST DISTRICT FROM LATE THIS WEEK INTO EARLY NEXT WEEK. AS
ALWAYS...WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY.
IMPROVING METEOROLOGICAL CONDITIONS SHOULD THEN BY NOTED BY
TUESDAY AS THE CLOSED UPPER LOW MOVES EAST OF THE FORECAST
DISTRICT. TEMPERATURES ARE STILL PROJECTED TO RUN NEAR LATE
MAY CLIMATOLOGICAL AVERAGES DURING THE LONGER TERM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 458 AM MDT WED MAY 21 2014
MVFR CIGS WILL CONTINUE TO EXPAND ACROSS THE SOUTHEAST
PLAINS THROUGH MORNING...WITH SOME POCKETS OF IFR CIGS ACROSS THE
PIKES PEAK REGION AND ALONG THE LOWER EASTERN SLOPES OF THE
SOUTHEAST MOUNTAINS. COULD EVEN SEE SOME PATCHY FOG. STRATUS
SHOULD ERODE BY 17-18Z FOR MOST AREAS WITH ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING DURING THE EARLY AFTERNOON ACROSS THE
SOUTHEAST MOUNTAINS AND NORTHERN SLOPES OF THE RATON RIDGE. THESE
WILL BE CAPABLE OF PRODUCING VFR TO LOCAL MVFR CIGS/VIS. LARGE HAIL
AND ERRATIC WIND GUSTS TO AROUND 50 KTS WILL BE POSSIBLE NORTH OF A
LINE FROM KCOS THE KLHX TO NORTH OF KSPD. THREAT DIMINISHES AFTER
00Z FOR THE KCOS AND KPUB TAF SITES. KALS WILL REMAIN DRY TODAY
WITH VFR CONDITIONS...THOUGH EXPECT A RETURN OF SOUTHWEST WINDS 15-
30 KTS IN THE AFTERNOON. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON TODAY TO 8 PM MDT THIS EVENING FOR
COZ224.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBANY NY
1034 PM EDT THU MAY 22 2014
.SYNOPSIS...
LOW PRESSURE AND AN ASSOCIATED FRONTAL SYSTEM WILL
SLOWLY MOVE ACROSS THE REGION OVERNIGHT...WITH SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS. ANOTHER POTENT UPPER LEVEL DISTURBANCE WILL
PASS SOUTH OF THE REGION ON FRIDAY...BRINGING MORE SHOWERS AND
ISOLATED THUNDERSTORMS. UNSETTLED CONDITIONS WILL LINGER INTO THE
START OF THE HOLIDAY WEEKEND...WITH IMPROVEMENT EXPECTED FOR SUNDAY
AND MONDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 1034 PM EDT...THE SCT SHOWER AND ISOLD THUNDERSTORM COVERAGE
HAS BEGUN TO DIMINISH TONIGHT WITH THE MOST PERSISTENT SHOWERS AND
ISOLD THUNDERSTORMS OVER THE SRN DACKS REGION...AND ERN CATSKILLS.
THE LATEST HIRESWRF AND 3-KM HRRR COLUMNAR REF PRODUCTS INDICATE
SCT SHOWERS CONTINUING OVERNIGHT...AS THE OCCLUDED BOUNDARY
FINALLY MOVES THROUGH...ESPECIALLY FROM THE CAPITAL REGION
NORTHWARD. BASED ON THE CURRENT OBSERVATIONAL TRENDS...THE SCT
SHOWERS HAVE BEEN KEPT IN EVERYWHERE AFTER MIDNIGHT WITH THE ISOLD
TSRAS BEING REMOVED AFTER 06Z/2AM WITH THE INSTABILITY WANING DUE
TO THE LOSS OF THE DIURNAL HEATING. SOME LOCAL BURSTS OF MDT-HVY
RAINFALL WILL STILL BE POSSIBLE /ESPECIALLY ACROSS THE SRN DACKS
AND W-CNTRL MOHAWK VALLEY/...BUT THE WIDESPREAD HEAVY RAIN THREAT
HAS DIMINISHED. LOWS TONIGHT WITH CLOUDY CONDITIONS PERSISTING
WILL BE IN THE U40S TO M50S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
FRIDAY-FRIDAY NIGHT...FRIDAY COULD BE ANOTHER ACTIVE DAY...BUT
SHOULD BE LESS IN THE WAY OF HAIL/SEVERE...AND POSSIBLY MORE IN
THE WAY OF LOCALLY HEAVY RAINFALL AS A POTENT UPPER LEVEL
DISTURBANCE PASSES OVER OR JUST SOUTH/WEST OF THE
REGION...ALLOWING FOR STRONG UPPER LEVEL DIVERGENCE TO DEVELOP
ONCE AGAIN. MID LEVEL WIND FIELDS SHOULD BE WEAKER THAN
TODAY...AND THE BOUNDARY LAYER A LITTLE MORE STABLE.
HOWEVER...SLOW MOVING SHOWERS AND PERHAPS EMBEDDED THUNDERSTORMS
COULD ALLOW FOR SOME LOCALLY HEAVY RAINFALL...ESP ACROSS HIGHER
ELEVATIONS OF THE SCHOHARIE VALLEY/EASTERN CATSKILLS...AS WELL AS
ACROSS THE UPPER HUDSON RIVER VALLEY AND SOUTHERN VT...WHICH WILL
HAVE THE GREATEST UPPER LEVEL FORCING COINCIDENT WITH LOW LEVEL
CONVERGENCE WITH THE SLOWLY ADVANCING OCCLUDED FRONTAL BOUNDARY.
SHOWERS AND THUNDERSTORMS SHOULD DIMINISH IN AREAL COVERAGE FROM
NORTH TO SOUTH FRI NIGHT. TEMPS SHOULD ONLY REACH THE MID TO UPPER
60S FRI...THEN FALL INTO THE UPPER 40S TO LOWER/MID 50S FRI NT.
SAT-SAT NT...ALTHOUGH THE MAIN MID/UPPER LEVEL LOW WILL PASS EAST
OF THE REGION...ADDITIONAL SHORTWAVE ENERGY WILL PASS SOUTH ON ITS
WESTERN PERIPHERY. LOW LEVEL INSTABILITY WILL BE GREATER...ESP
SHOULD BREAKS IN THE CLOUDS OCCUR. SO...SOME TALLER CONVECTIVE
ELEMENTS COULD CONTAIN HAIL ONCE AGAIN. OVERALL AREAL COVERAGE
SHOULD BE SCATTERED...A LITTLE LESS THAN TODAY. TEMPS SHOULD REACH
THE UPPER 60S TO LOWER 70S IN VALLEYS...AND LOWER/MID 60S FOR
HIGHER ELEVATIONS. SHOWERS SHOULD TAPER OFF SAT NT...AS TEMPS FALL
INTO THE 40S IN MOST AREAS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
A PATTERN MORE TYPICAL OF SUMMER TAKES SHAPE AS WE APPROACH MEMORIAL
DAY. HIGH TEMPERATURES ON SUNDAY WILL BE IN THE UPPER 60S IN THE
MOUNTAINS...IN THE LOW TO UPPER 70S ELSEWHERE. FROM MEMORIAL DAY
THROUGH THURSDAY...HIGHS WILL BE MAINLY IN THE 70S AND LOWER 80S...
ALTHOUGH WEDNESDAY COULD BE SLIGHTLY COOLER...WITH SOME READINGS
AROUND 70 DEGREES SHOWING UP IN THE MOUNTAINS...WITH BARELY 80
DEGREES IN THE MID HUDSON VALLEY. SUNDAY NIGHT LOW TEMPERATURES
WILL BE IN THE 40S AND 50S...WITH READINGS REBOUNDING BY ABOUT 7
DEGREES FOR MONDAY NIGHT...FOLLOWED BY A SLIGHT REBOUND FOR THE LAST
TWO NIGHTS OF THE EXTENDED.
HIGH PRESSURE WILL MAKE A SHORT-LIVED APPEARANCE ON SUNDAY WITH A
WEAK SURFACE TROF OF LITTLE CONCERN SETTING UP JUST SOUTH AND EAST
OF OUR FORECAST AREA ON MONDAY. SHOWERS RETURN ON TUESDAY AS LOW
PRESSURE AND A COLD FRONT DIP THROUGH OUR ZONES FROM THE EASTERN
GREAT LAKES...SETTING OFF SHOWERS. LITTLE INSTABILITY OR MOISTURE
IS EXPECTED...BUT IT WILL BE A MOSTLY CLOUDY DAY. THE FRONT WILL
CONTINUE TO SLOWLY SINK SOUTH THROUGH THE MID-ATLANTIC REGION...
LIMITING CHC POPS TO OUR ZONES SOUTH OF ALBANY. WEDNESDAY NIGHT AND
THURSDAY WILL BE MAINLY DRY WITH A WEAK WARM FRONT PASSING TO OUR
NORTH.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
THERE ARE STILL SHOWERS AND EVEN A FEW THUNDERSTORMS ACROSS THE REGION.
SCATTERED ACTIVITY MIGHT PERSIST AWHILE THROUGH THIS EVENING...SO
HAVE CONTINUE VCSH EVERYWHERE THROUGH 06Z.
DURING THE EVENING HOURS...LOOK FOR MAINLY VFR...OCCASIONALLY MVFR
POSSIBLE IN SHOWERS. LATER OVERNIGHT...EVEN IF SHOWERS
DECREASE...LOOK FOR CIGS TO LOWER LOW MVFR OR IFR AT ALL THE
SITES.
CIGS WILL SLOWLY LIFT BACK TO MVFR LATER IN THE MORNING.
HOWEVER...SHOWERS AND POSSIBLY EVEN THUNDERSTORMS WILL LIKELY
DEVELOP AGAIN BY TOMORROW AFTERNOON AS ANOTHER TROUGH DIGS ACROSS
THE REGION. MAINLY VFR CONDITIONS ARE EXPECTED BUT COULD BRIEFLY
DROP TO MVFR OR IFR IN SHOWERS.
THE WIND WILL BE LIGHT OR SOUTHERLY GENERALLY UNDER 10KTS
OVERNIGHT...SHIFTING TO NORTHWEST 5-10KTS TOMORROW...POSSIBLY SOME
HIGHER GUSTS IN AFTERNOON THUNDERSTORMS.
OUTLOOK...
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA.
SUNDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MEMORIAL DAY: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA.
TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
UNSETTLED WEATHER IS EXPECTED INTO THE START OF THE HOLIDAY
WEEKEND. A LOW PRESSURE SYSTEM AND ITS ASSOCIATED FRONTAL SYSTEM WILL
PASS ACROSS THE REGION TONIGHT. DISTURBANCES IN THE UPPER LEVELS
OF ATMOSPHERE WILL MOVE OVER THE REGION FRIDAY THROUGH SATURDAY.
HIGH PRESSURE WILL BUILD IN FOR THE LATTER PART OF THE WEEKEND.
&&
.HYDROLOGY...
UNSETTLED WEATHER IS EXPECTED INTO THE START OF THE HOLIDAY
WEEKEND. HAVE FAVORED GUIDANCE FROM THE WEATHER PREDICTION
CENTER/NORTHEAST RIVER FORECAST CENTER FOR THE FORECAST...LOOKING
AT TOTAL RAINFALL AMOUNTS THROUGH FRIDAY NIGHT UP TO AN INCH.
HOWEVER...SOME LOCALLY HIGHER AMOUNTS MAY OCCUR WHERE
THUNDERSTORMS PRODUCE HEAVIER RAINFALL AND PERSIST OVER ANY
AREAS...WHICH COULD RESULT IN SOME LOCALIZED FLASH FLOODING OF
POOR DRAINAGE AND LOW LYING AREAS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...KL/WASULA
NEAR TERM...KL/WASULA
SHORT TERM...KL
LONG TERM...ELH
AVIATION...HWJIV
FIRE WEATHER...IAA/KL
HYDROLOGY...IAA/KL
AREA FORECAST DISCUSSION
NWS TAUNTON MA
758 PM EDT THU MAY 22 2014
.SYNOPSIS...
LOW PRESSURE WILL BRING OCCASIONAL SHOWERY WEATHER AND COOL
TEMPERATURES INTO SATURDAY. TURNING MILDER SUNDAY THEN WARM AND
DRY CONDITIONS EXPECTED FOR MEMORIAL DAY. A WEAK FRONT MAY BRING
SCATTERED SHOWERS TUESDAY INTO EARLY WEDNESDAY ALONG WITH COOLER
TEMPERATURES.
&&
.NEAR TERM /THROUGH FRIDAY/...
7 PM UPDATE...
ONE HECK OF A FORECAST AND A CHALLENGING ONE AT THAT. A FEW POINTS
WORTH NOTING:
LINE OF SHOWERS PRESENTLY ACROSS S-CENTRAL NEW ENGLAND SHOULD
PROGRESS SE PARENT WITH LEAD IMPULSES THROUGH THE CYCLONIC FLOW. A
MAJORITY OF THE WET-WEATHER SHOULD PUSH OFFSHORE TOWARDS MIDNIGHT
WILL A LULL TOWARDS MORNING. MUCH OF THE ACTIVITY IS LIKELY
ELEVATED ABOVE THE AVERAGE ONSHORE SE FLOW OF COOLER AIR OFF THE
WATERS. LITTLE TO NO INSTABILITY...SO NOT EXPECTING ANY THUNDER.
THEN THERES A REPEAT OF FOG USHERED IN BY THE E/SE FLOW AS
MENTIONED ABOVE. FEEL THE HRRR IS HANDLING THE PROGRESSION OF FOG
AND LOW VISIBILITIES WELL BUT THERE IS SOME QUESTION AS TO WHETHER
THE ONCOMING RAINS WILL WASH OUT THE SOUPY MESS. IN ADDITION...NO
CERTAINTY AS TO WHETHER FOG WILL BE WIDESPREAD ALONG THE E-SHORE
AS IT WAS LAST NIGHT. SO WILL HOLD OFF ON ISSUING A SPECIAL
WEATHER STATEMENT.
HAVE GONE AHEAD WITH AREAS OF DENSE FOG IMPACTING THE CAPE AND THE
ADJACENT WATERS. WILL HOLD OFF ON IMPACTS ELSEWHERE. VERY WET OUT
ACORSS THE INTERIOR AND WITH WINDS BECOMING LIGHT AND VARIABLE...
THERE IS THE POSSIBILITY OF DENSE FOG...BUT NAILING DOWN WHERE AND
WHEN IS THE GREATEST DIFFICULTY. NOT LEAVING THE BEST FORECAST DUE
TO THE LACK OF CREDIBLE GUIDANCE.
&&
.SHORT TERM /FRIDAY NIGHT/...
FRIDAY...
STRONGER SHORTWAVE WILL BE DIGGING SE FROM THE GT LAKES WITH SHARP
TROF APPROACHING FROM THE WEST. WHILE LOW PRES WILL BE CUTTING TO
THE S OF NEW ENG AN INVERTED TROF SETS UP ACROSS FAR W NEW ENG IN
RESPONSE TO THE STRONG SHORTWAVE. THIS IS WHERE WE EXPECT THE MAIN
FOCUS FOR SHOWERS TO BE...BUT SCT SHOWERS EXPECTED FURTHER TO THE
EAST AS MOISTURE DEEPENS WITH PERSISTENT QG FORCING. MODELS
INDICATE SOME WEAK SFC INSTABILITY IN THE WEST SO POTENTIAL FOR A
FEW TSTMS AS WELL. INCREASING LOW LEVEL EASTERLY FLOW WILL RESULT
IN COOLER TEMPS WITH MAXES UPPER 50S TO LOWER 60S.
FRIDAY NIGHT...
SHOWERS AND ISOLD TSTMS CONTINUE INTO THE EVENING AS THE TROF
MOVES ACROSS SNE WITH LOW PRES PASSING TO THE SE. MODELS KEEP THE
FOCUS IN WESTERN NEW ENG WHERE BEST LOW LEVEL CONVERGENCE AND MID
LEVEL OMEGA. AS THE TROF SHIFTS TO THE EAST OVERNIGHT A DECREASE
IN THE SHOWERS EXPECTED. MORE STRATUS AND PATCHY FOG LIKELY GIVEN
PERSISTENT LOW LEVEL MOISTURE AND EAST FLOW.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...
- WEEKEND CHANCES OF SHOWERS/THUNDERSTORMS ACROSS THE INTERIOR
- NICE AND MILD FOR MEMORIAL DAY
- ANOTHER SHOT OF WET WEATHER FOR TUESDAY
- CLASH OF AIRMASSES AND UNCERTAIN WEATHER FOR THE REST OF THE WEEK
/ OVERVIEW AND MODEL PREFERENCE...
AN UNSTABLE LONG-TERM FORECAST BY NEXT WEEK AS EXHIBITED BY THE NAO
TREND. YESTERDAY NEAR-NEUTRAL WITH A NEGATIVE TREND HAS NOW SHIFTED
POSITIVE TOWARDS THE END OF MAY. THOUGH THE NAEFS/CANADIAN CONTINUES
TO EXHIBIT A POSITIVE HEIGHT ANOMALY OVER THE HUDSON BAY REGION...
THE TREND OF ABOVE AVERAGE TEMPERATURES HAS SOMEWHAT DIMINISHED.
SO CONSIDERING THE LOW LIFTING INTO THE CENTRAL PLAINS...THE RIDGE
SHOULD STRENGTHEN AHEAD. BUT AN ICELANDIC LOW PROVIDING THE MEANS OF
DOWNSTREAM BLOCKING APPEARS TO LIMIT THE PROGRESSIVENESS OF THE LONG-
WAVE FLOW AND THEREBY RESULTS IN TROUGHING LINGERING IN PROXIMITY TO
NEW ENGLAND AND ACROSS THE NW-ATLANTIC. THIS POINT IS EXACERBATED BY
A COMPARISON OF GEFS RUNS WHICH SHOWS A TREND TOWARDS A STRONGER
INFLUENCE OF THE W-PERIPHERY OF THE TROUGH RESULTING IN COOLER AIR
ALOFT ACROSS THE REGION. WPC NOTES THE ECENS IS DEEPER WITH THE
TROUGH WHEREAS THE GEFS IS SHARPER AND SLOWER. THE NAEFS IS THE
MIDDLE GROUND. THUS AM EXPECTING A CLASH OF AIRMASSES ACROSS THE NE-
CONUS WITH WARMER AIR SW AND COOLER AIR NE.
HAVE HIGH CONFIDENCE IN THE FORECAST THROUGH MONDAY USING A MODEL
CONSENSUS BLEND. SPREAD INCREASES BY TUESDAY...SO WILL LEAN MORE
TOWARDS MODEL ENSEMBLE MEANS KEEPING THE TROUGH IN CLOSER PROXIMITY
TO THE NE-CONUS AND HOLDING COOLER CONDITIONS ACROSS THE REGION AND
LIMITING THE INFLUENCE OF THE RIDGE FROM THE W.
/ DAY-TO-DAY DETAILS...
SATURDAY...
INVERTED TROUGH IS THE FOCUS OF LOCALIZED CONVERGENCE BENEATH WEAK
DISTURBANCES ALOFT WHICH WILL YIELD SOME MEASURE OF LIFT. NOTING
COOLER AIR WRAPPING REARWARD OF THE DEPARTING LOW. MID-LEVELS LAPSE
RATES SHOULD STEEPEN. LOOKING LIKE A CLOUDY COOL DAY WITH SCATTERED
SHOWERS AND THUNDERSTORMS THE BETTER CHANCES OF WHICH WILL BE ALONG
THE INVERTED TROUGH IN A REGION OF FAVORABLE LIFT AND INSTABILITY.
THAT AREA IS MAINLY ACROSS THE W-INTERIOR AND HUDSON RIVER VALLEY
REGION. ONSHORE E-FLOW WILL KEEP THE CENTRAL AND EASTERN FORECAST
AREA UNDER A MORE STABLE COOL AIRMASS THEREBY LIMITING ACTIVITY...
BUT NOT DOWN TO ZERO.
WITH ANY ACTIVITY...HEAVY RAIN AND GUSTY WINDS ARE POSSIBLE. WITH
THE DEEP-LAYER NNW FLOW ALONG THE INVERTED FRONT...STORMS MAY TRAIN
SO PERHAPS THERE IS A LOCALIZED FLOODING THREAT. THOUGH AGAIN...FEEL
THE BETTER CHANCES MAY REMAIN W OF NEW ENGLAND. WILL HAVE TO CLOSELY
WATCH OUT FOR IMPACTS ACROSS THE CT-RIVER VALLEY.
ACTIVITY CONCLUDES INTO EVENING. WILL HOLD WITH NEAR-SEASONABLE
TEMPERATURES OVER THE W AND CENTRAL INTERIOR OF NEW ENGLAND BUT
COOLER ALONG THE SHORES WITH ANTICIPATED SEA-BREEZE. ANTECEDENT
RAINS WITH LIGHT AND VARIABLE FLOW OVERNIGHT...IF CONDITIONS ARE
ALLOWED TO CLEAR OUT...THERE IS A GREATER PROPENSITY FOR DENSE FOG.
SUNDAY...
CONTINUED CYCLONIC FLOW BUT LESSER FORCING MECHANISMS. THE COLD POOL
LINGERS ALOFT CONTINUING THE PRESENCE OF STEEP MID-LVL LAPSE RATES.
AS THE BOUNDARY LAYER DESTABILIZES...EXPECT SHOWERS AND POSSIBLE
THUNDERSTORMS TO DEVELOP...BUT ON A MORE ISOLATED NATURE AND AGAIN
MAINLY ACROSS THE INTERIOR WITH THE LIKELIHOOD OF SEA-BREEZES ALONG
THE SHORES USHERING IN MORE STABLE AIR.
WILL PREVAIL WITH SEASONABLE TEMPERATURES. STORM MOTION SHOULD BE N
TO S. WITH ANY STORMS...HEAVY RAIN AND GUSTY WINDS ARE POSSIBLE. NO
CERTAINTY IN PINPOINTING WHERE AND WHEN STORMS WILL DEVELOP. WEATHER
SHOULD TURN QUIET OVERNIGHT AS DAYTIME HEATING CONCLUDES.
MONDAY...
WILL KEEP WITH A DRY FORECAST BUT WILL NEED TO MONITOR ADDITIONAL
ENERGY CYCLONICALLY DIGGING THROUGH THE PREVAILING TROUGH PATTERN
ACROSS N NEW ENGLAND. HAVE A FEELING THAT RIDGING WILL PREVAIL
BETWEEN THE DEPARTING WEEKEND DISTURBANCE AND THE EXPECTED DISTURBED
WEATHER FOR TUESDAY. THEREFORE...SUBSIDENCE PREVAILING WITH H85
TEMPERATURES AROUND +12C WILL YIELD WARM CONDITIONS WITH THE GREATER
CHANCE OF MOSTLY CLEAR CONDITIONS TO THE S AND W. THE SUBSEQUENT
BOUNDARY LAYER MIXING WILL YIELD BREEZY W-WINDS.
TUESDAY...
A FRONTAL DISTURBANCE WILL SWEEP ACROSS NEW ENGLAND FROM THE NW TO
SE. WILL SEE LIKELY SEE SHOWERS AND THUNDERSTORMS ALONG AND AHEAD
PENDING ON THE TIMING OF THE DISTURBANCE WHICH IS KEY TOWARDS
WHETHER THE BOUNDARY LAYER WILL DESTABILIZE ALONG AND AHEAD. SIGNALS
HAVE BEEN CONSISTENT WITHIN THE MODELS AS TO OUTCOMES...YET WILL
EXERCISE CAUTION AND CONCLUDE IN DISCUSSION WITH THE SPREAD AND
VARIANCE OF OUTCOMES.
REST OF THE WEEK...
TOWARDS MIDWEEK AM EXPECTING A WARM-FRONT ALONG THE MID-LEVEL CLASH
OF AIRMASSES ALONG WHICH DISTURBANCES WILL TRAIN THROUGH THE
CYCLONIC FLOW POTENTIALLY PROVIDING PERIODS OF INCLEMENT WEATHER.
TOO MUCH SPREAD AS TO THE INFLUENCE OF RIDGING AGAINST THE LINGERING
TROUGH LENDS TO A LOT OF UNCERTAINTY. AGAIN...WILL PREVAIL TOWARDS
MODEL ENSEMBLE MEANS.
&&
.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH FRIDAY NIGHT/...LOW CONFIDENCE.
MIX OF IFR-VLIFR CONDITIONS. GOOD CHANCE OF 1/4SM FG DEVELOPING
ACROSS THE CAPE AND ADJACENT WATERS. UNCERTAIN ITS EXTENT TOWARDS
EASTERN MA...THOUGH WITH THE LGT/VRB WINDS ACROSS THE INTERIOR AND
LATEST RAINS...COULD SEE FOG PREVAIL. WILL NEED TO BE MONITORED
CLOSELY TOWARDS MORNING.
LAST OF SHOWERS SHOULD MOVE OUT OF THE REGION BY 4Z...LULL INTO
THE OVERNIGHT HOURS TOWARDS MORNING BY WHICH TIME SHOWERS SHOULD
BE DEVELOPING AGAIN ACROSS WESTERN MA. E/SE FLOW WITH A MIX OF
MVFR-IFR CONDITIONS AND RAIN. LOW CONFIDENCE TSRA /ISOLATED
ACTIVITY AT BEST/. FOG MAY LINGER FOR AREAS OF SOUTHERN NEEW
ENGLAND. RAINS BECOMING MORE WIDESPREAD TOWARDS EVENING WITH
LIKELY A RENEWED THREAT OF FOG.
KBOS TAF...VERY LOW CONFIDENCE. LOW CLOUDS LIKELY TO DEVELOP BUT
UNCERTAIN IF FOG OFF THE WATERS WILL IMPACT THE TERMINAL. IF IT
DOES SO...LIKELY TOWARDS MORNING. HAVE A TEMPO GROUP ACCORDINGLY.
KBDL TAF...LOW CONFIDENCE. RAINS WILL MOVE OUT...BUT THE WET
CONDITIONS AND LGT/VRB FLOW THAT MAY DEVELOP OVERNIGHT WOULD
EXACERBATE IFR-VLIFR FOG POTENTIAL. DID NOT MENTION WITH THE VERY
LOW CONFIDENCE. WILL HAVE TO MONITOR.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY...MODERATE CONFIDENCE.
BKN LOW-END VFR CIGS. SCT -SHRA/TSRA THE BETTER CHANCE OF WHICH WILL
BE ACROSS W-INTERIOR NEW ENGLAND TOWARDS THE HUDSON RIVER VALLEY.
TEMPO IFR WITH TSRA WITH +RA AND GUSTY WINDS. SEA-BREEZES ALONG THE
SHORES. WITH ACTIVITY CLEARING OVERNIGHT...IF WINDS BECOME LIGHT...
DENSE IFR FOG POSSIBLE.
SUNDAY...MODERATE CONFIDENCE.
BKN LOW-END VFR CIGS. ISOLATED -SHRA/TSRA ACROSS INTERIOR NEW
ENGLAND. SEA-BREEZES ALONG THE SHORES. ACTIVITY CONCLUDES OVERNIGHT.
MONDAY...LOW CONFIDENCE.
WILL CONTINUE TO HOLD VFR WITH GUSTY W-WINDS UP TO AROUND 25 KTS.
TUESDAY...LOW CONFIDENCE.
CONDITIONS DETERIORATING BY MORNING. WIDESPREAD RAIN WITH EMBEDDED
HEAVIER SHRA AND POSSIBLE TSRA. WILL SEE A COLD FRONT SWEEP ACROSS
THE TERMINALS. TERMINALS BEGINNING TO IMPROVE W TO E BY EVENING.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH FRIDAY NIGHT/...HIGH CONFIDENCE.
WINDS AND SEAS BELOW SCA THRESHOLDS THROUGH FRI EVENING WITH
EASTERLY FLOW. BUT CANT RULE OUT MARGINAL SCA CONDITIONS LATE FRI
NIGHT AS LOW LEVEL NE FLOW INCREASES AS LOW PRES PASSES TO THE
SOUTH. G20-25 KT AND 5 FT SEAS POSSIBLE FOR WATERS SE OF CAPE
COD.
THE MAIN CONCERN ON THE WATERS IS FOR AREAS OF
FOG WHICH COULD BE LOCALLY DENSE AT TIMES...PARTICULARLY DURING
THE LATE NIGHT/EARLY MORNING HOURS.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY INTO SUNDAY...MODERATE CONFIDENCE.
WHILE DAILY OCCURRENCES OF SEA-BREEZES ALONG THE SHORES ARE TO BE
EXPECTED...WINDS OVERALL INITIALLY OUT OF THE NE WILL VEER OUT OF
THE SW WITH TIME. SEAS TO REMAIN BELOW 5 FEET. DENSE FOG WILL BE
POSSIBLE ACROSS THE WATERS SATURDAY NIGHT INTO SUNDAY MORNING
RESULTING IN SIGNIFICANT VISIBILITY RESTRICTIONS.
MONDAY...LOW CONFIDENCE.
W/SW WINDS WITH GUSTS UP TO 25 KTS. SEAS ON THE OUTER-WATERS
GETTING UP TO 5 FEET.
TUESDAY...LOW CONFIDENCE.
INCREASING RAIN CHANCES AS A FRONT SLIDES ACROSS THE WATERS LATE.
WILL SEE SW WINDS BACK OUT OF THE NW WITH FRONTAL PASSAGE. WAVES
GETTING UP TO 5 FEET ON THE OUTER WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KJC/SIPPRELL
NEAR TERM...KJC/SIPPRELL
SHORT TERM...KJC
LONG TERM...SIPPRELL
AVIATION...KJC/SIPPRELL
MARINE...KJC/SIPPRELL
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
936 AM EDT WED MAY 21 2014
.SYNOPSIS...
A WARM FRONT FROM THE GREAT LAKES TO VIRGINIA WILL MOVE TO THE
SOUTHERN NEW JERSEY AND DELAWARE COASTS TONIGHT WHERE LOW PRESSURE
FORMS AND HEADS OUT TO SEA. A COLD FRONTAL PASSAGE FOLLOWS LATER
THURSDAY NIGHT. HIGH PRESSURE IN THE MIDWEST ON FRIDAY FINALLY
ARRIVES ALONG THE MID ATLANTIC COAST ON SUNDAY THEN BECOMES PART OF
THE BERMUDA HIGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS CONTINUE TO STREAM DOWN FROM THE NORTHWEST INTO
SOUTHEASTERN PA, SOUTHERN NJ, DE AND EASTERN MD THIS MORNING IN
ASSOCIATION WITH A MID LEVEL SHORTWAVE. THERE HAVE BEEN A FEW
STRIKES OF LIGHTNING TO THE NORTHWEST OF THE AREA SO A RUMBLE OF
THUNDER MAY STILL BE HEARD AS THE SHOWERS MOVE THROUGH.
THE BIG STORY OF TODAY WILL BE THE WARM FRONT AND ASSOCIATED
SHOWER AND THUNDERSTORM ACTIVITY IN THE WARM SECTOR. STILL LOOKS
TO BE SOME INSTABILITY, HOWEVER THERE ARE A FEW DIFFERENCES FROM
THE PREVIOUS MODEL RUNS WITH REGARDS TO THE STRONG STORM THREAT.
FIRST, BOTH THE RAP AND THE NAM ARE SHOWING A DRIER LOW LEVEL
PRIMARILY DUE TO A LATER ARRIVAL OF THE WARM FRONT, AND THUS LATER
ONSET OF LOW LEVEL MOISTURE ADVECTION. THIS, COMBINED WITH A
POSSIBLE WEAK INVERSION AROUND 800 MB, HAS LEAD TO LOWER ML CAPE
VALUES, NOW GENERALLY 100 J/KG OR LESS (EXCEPT FOR SOUTHERN
DELMARVA). HOWEVER, IN DELMARVA, IT STILL LOOKS LIKE K INDEX WILL
BE IN THE LOW 30S, LI WILL BE NEAR ZERO BY MID DAY. THUS, WILL
CONTINUE THE MENTION IN THE HWO FOR STRONG STORMS (PRIMARILY A
WIND THREAT GIVEN A RELATIVELY HIGH MELTING LEVEL). WITH THE LATER
ONSET OF MOISTURE ADVECTION, PWAT VALUES THROUGH THIS TIME LOOK TO
BE AT OR LESS THAN 1.5 IN, WHICH IS STILL ABOVE NORMAL, SO COULD
STILL SEE SOME HEAVY RAIN. AS WITH THE WIND THREAT, THIS THREAT IS
PRIMARILY FOR DELMARVA, WHERE THE 3 HR FLASH FLOOD GUIDANCE VALUES
ARE GENERALLY ABOVE 3 IN. THUS, DO NOT EXPECT A BIG FLOODING
THREAT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
SHOULD CONTINUE TO SEE INCREASING LOW LEVEL MOISTURE THROUGH THIS
PERIOD, SO EXPECT LOW CLOUDS, AND POSSIBLY SOME PATCHY FOG. CHANCES
FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE THROUGH THIS
PERIOD, THOUGH THERE MAY BE A BRIEF LULL LATE OVERNIGHT TONIGHT IN
BETWEEN THE WARM FRONT LIFTING NORTH OF THE REGION, AND COLD FRONT
EXPECTED LATER ON THURSDAY.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
5-WAVE GUIDANCE SHOWS RELATIVELY WEAK TROUGHING ACROSS THE EAST WITH
WEAK RIDGING ACROSS THE CENTRAL PORTION OF THE U.S. TO START THE
PERIOD. THE TROUGHING TRIES TO BECOME BETTER ESTABLISHED THROUGH THE
THE WEEKEND BEFORE RIDGING KICKS IT TO THE EAST BY EARLY NEXT WEEK.
A WEAK HIGH LATITUDE OMEGA BLOCK LOOKS POSSIBLE THROUGH THE END OF THE
WEEK AND HENCE THE AMOUNT OF UNSETTLED WEATHER EXPECTED THROUGH THE
FIRST HALF OF THE LONGTERM PERIOD.
SURFACE WARM FRONT SHOULD BE MOVING THROUGH THE REGION THURSDAY
MORNING AS A MID-LEVEL SHORTWAVE MOVES ALONG THE BOUNDARY WITHIN THE
NORTHWEST FLOW ALOFT. THIS COULD CONTINUE TO USHER THE DECAYING
GREAT LAKES MCS THROUGH NORTHERN PENNSYLVANIA BEFORE IT DIVES
FURTHER SOUTHEAST, POSSIBLY CLIPPING OUR NORTHERN AND WESTERN ZONES.
WITH THIS FEATURE THROUGH BY LATE THURSDAY MORNING THERE SHOULD BE A
LULL IN THE ACTION, AT LEAST ACROSS OUR SOUTHERN ZONES. MORE
MID-LEVEL SHORTWAVES WILL MOVE THROUGH IN THE CYCLONIC FLOW ALOFT
AND COULD TRIGGER MORE SHOWERS WITH EMBEDDED THUNDER ACROSS OUR
NORTHERN ZONES. LOW PRESSURE MOVES THROUGH THE GREAT LAKES LATER ON
THURSDAY AND PULLS A COLD FRONT THROUGH OUR REGION DURING THE
EVENING HOURS WITH MORE SHOWERS AND POSSIBLE THUNDERSTORMS.
FRIDAY SHOWS ANOTHER BATCH OF EMBEDDED MID-LEVEL ENERGY TRAVERSING
THE REGION WHICH COULD TOUCH OFF SOME SCATTERED INSTABILITY SHOWERS
WITH THE MID-LEVEL COLD POOL NOT TOO FAR REMOVED TO OUR NORTH. MUCH
CAN BE SAID ABOUT SATURDAY THAT CAN BE SAID ABOUT FRIDAY SO WE
CONTINUE WITH THE CHANCE POPS.
THE "BLOCKY" PATTERN BEGINS TO BREAK DOWN, BETTER ESTABLISHED
TROUGHING MOVING TOWARDS THE EAST, HEADING INTO THE LATER PART OF
THE WEEKEND. DEEP LAYER RIDGING ENTERS FROM THE WEST AND WE SHOULD
DRY OUT NICELY SUNDAY AND MEMORIAL DAY. SURFACE HIGH PRESSURE MOVES
OFFSHORE BY TUESDAY OF NEXT WEEK GIVING WAY TO A STRONG RETURN FLOW
AND ANOTHER INFLUX OF TROPICAL MOISTURE. THE NEXT SYSTEM LOOKS TO
ENTER FROM THE SOUTHWEST LATER ON TUESDAY WITH MORE SHOWERS.
TEMPERATURES THROUGHOUT THE PERIOD WILL FLUCTUATE TOWARDS BELOW NORMAL ON
FRIDAY AND SATURDAY CLIMBING AGAIN TO NORMAL ON SUNDAY AND THEN
SEVERAL DEGREES ABOVE NORMAL ON MONDAY AND TUESDAY.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CEILINGS WILL SLOWLY LOWER THROUGH THE DAY, WITH CONDITIONS
DETERIORATING TO MVFR AFTER 21Z. HOWEVER, LOCALIZED MVFR VISIBILITIES
ARE POSSIBLE AHEAD OF 21Z, IN THE VICINITY OF ANY THUNDERSTORMS.
SOME SHOWERS ARE MOVING THE REGION WITH SOME MVFR CONDITIONS
OCCURRING FOR A BRIEF PERIOD OF TIME. THESE SHOWERS WILL CONTINUE
TO MOVE TO THE SOUTHEAST AND ARE PRIMARILY ONLY AFFECTING KRDG,
KILG AND WILL MOVE TOWARD KMIV, POSSIBLY AFFECTING KACY AS WELL.
WE EXPECT A PERIOD OF SHOWERS TO ARRIVE AROUND MID DAY, BEFORE WE
COULD SEE ANOTHER ROUND OF THUNDERSTORMS, THIS TIME GENERALLY FOR
DE AND MD (INCLUDING KILG) AFTER 18Z. NOTE THAT THERE IS A SMALL
RISK OF THUNDERSTORMS ACROSS THE REGION. HOWEVER, CONFIDENCE IS
ONLY HIGH ENOUGH TO INCLUDE A PROB30 GROUP AT THE KILG TAF AT THIS
TIME.
A COMBINATION OF LOWERING CEILINGS AND POSSIBLY SOME BR DEVELOPMENT
WILL LEAD TO WIDESPREAD MVFR WITH LOCALIZED IFR CONDITIONS AFTER
21Z, CONTINUING THROUGH WEDNESDAY NIGHT.
OUTLOOK...
THURSDAY...MVFR OR LOWER IN SCATTERED SHOWERS AND THUNDERSTORMS.
BETTER CHANCE FOR SHOWERS WILL BE NORTH OF PHL EARLY IN THE DAY.
COLD FRONT PASSAGE LATER IN THE DAY WILL BACK WINDS TOWARDS THE
WEST-NORTHWEST.
FRIDAY - SATURDAY...MVFR OR LOWER IN SCATTERED SHOWERS. LESS OF A
CHANCE OF THUNDER BOTH DAYS WHEN COMPARED TO THURSDAY.
SUNDAY...VFR.
&&
.MARINE...
WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY
CONDITIONS. WINDS MAY OCCASIONALLY GUST NEAR 20KT THIS AFTERNOON AND
EVENING ESPECIALLY IN THE VICINITY OF ANY THUNDERSTORMS. AREAS OF
FOG COULD DEVELOP AFTER SUNSET TONIGHT, PRIMARILY OVER THE DELAWARE
BAY AND THE ATLANTIC COASTAL WATERS FROM THE DELAWARE BEACHES UP TO
ATLANTIC CITY.
OUTLOOK...
THURSDAY - SUNDAY...SUB-SCA CONDITIONS ARE EXPECTED. SHOWERS AND
THUNDERSTORMS ARE POSSIBLE EACH DAY THROUGH SATURDAY.
&&
.EQUIPMENT...
THE KDIX RADAR REMAINS OUT OF SERVICE. TECHNICIANS ARE CONTINUING TO
WORK HARD ON RESOLVING THE ISSUE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DRAG
NEAR TERM...JOHNSON/MEOLA
SHORT TERM...JOHNSON
LONG TERM...HEAVENER
AVIATION...HEAVENER/JOHNSON/MEOLA
MARINE...HEAVENER/JOHNSON
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
403 AM EDT Wed May 21 2014
.Near Term [Through Today]...
After keeping an eye out for some potential dense fog across SE AL
and western portions of the FL Panhandle this morning, a mostly
sunny, hot, and fairly dry day is expected across the region this
afternoon, with just a possible shallow CU field along the sea
breeze front. High temps should range from the middle 80s along the
coast to the lower 90s over much of the interior, with even hotter
weather on tap for the end of the week.
.Short Term [Tonight Through Friday]...
A deep and vertically-stacked ridge will be situated basically
right on top of our forecast area for the end of the work week
(Thursday and Friday). In fact, the 500mb heights will build close
to 5900m which is around 1.5 standard deviations above normal.
850mb temperatures are also forecast to increase into the +19C
range, which is close to 2 standard deviations above normal and
right around the 99th percentile for May for Tallahassee. This
creates high confidence in above-normal temperatures for both
days, and it seems likely that model guidance is underestimating
potential highs. Other factors favoring hot weather include the
surface-850mb ridge axis being positioned just west of our area,
setting up northwesterly low-level flow which could suppress the
inland progression of the sea breeze. Additionally, the column
should be fairly dry (and thus limited to no cloud cover is
expected) with 1000-500mb deep layer RH less than 40%. For
Thursday, model guidance is more tightly clustered in the lower
90s, whereas a couple rule-of-thumb charts based on 850mb temps
suggest mid 90s are likely with a few upper 90s not out of the
question. The latest forecast calls for widespread mid-90s on
Thursday, which is warmer than guidance. However, it`s not
inconceivable that a few upper 90s could occur. Thursday should
see fairly deep mixing, and given the dry column the surface RH
and dewpoints should be relatively low. For Friday, there may be a
little more humidity. Guidance is warmer overall - in the mid 90s
- and that is also what our forecast calls for.
.Long Term [Friday Night Through Wednesday]...
The long term period will be hot and for the most part dry as deep
layer ridging will park itself over our CWA. Late in the weekend a
weak frontal boundary will position itself over our CWA. With the
frontal boundary combined with the inland progression of the sea
breeze, there may be potential for some isolated thunderstorms to
develop in the afternoon and early evening. Therefore maintained a
20-25% PoP from Sunday afternoon through the end of the period with
the greatest chance of a thunderstorm being generally north of the
Florida border.
&&
.Aviation...
[Through 06Z Thursday] Fairly tricky fog fcst across the terminals
tonight with the potential for a repeat of IFR/LIFR conditions at
ECP. Though most of the guidance is very skeptical, the HRRR and
developing Satellite imagery are not, and am also a bit concerned
for some dense fog approaching DHN before the overnight hours are
through. Also expect some minor MVFR level conditions at TLH and VLD
for a short period. Any fog should burn off rapidly during the day
today, with VFR conditions quickly returning.
&&
.Marine...
Winds should be less than 15 knots with seas 2 feet or less
through the weekend, with no rain or thunderstorms expected.
Locally stronger and gusty winds are possible near the coast each
afternoon due to the sea breeze. It`s possible we may have more
active rip currents along the Walton, Bay, and Gulf County beaches
on Thursday and Friday with gusty onshore flow, surf heights as
high as 2 feet, and a longer fetch of westerly flow over the far
northern Gulf of Mexico.
&&
.Fire Weather...
Although afternoon relative humidities will be very low across much
of the interior on Thursday, no other criteria will be met to cause
any Red Flag concerns.
&&
.Hydrology...
Only one area river is currently in minor flood, the Steinhatchee.
The Choctawhatchee at Bruce is forecast to reach minor flood stage
late Tonight, cresting just above flood at 13.2 feet. Little or
no rainfall is expected through next weekend.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 91 63 96 65 95 / 0 0 0 0 0
Panama City 87 68 90 70 89 / 0 0 0 0 0
Dothan 91 65 93 67 94 / 0 0 0 0 0
Albany 91 65 94 67 94 / 0 0 0 0 0
Valdosta 93 65 97 66 97 / 0 0 0 0 0
Cross City 90 62 93 65 93 / 0 0 0 0 0
Apalachicola 83 67 89 70 89 / 0 0 0 0 0
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...GOULD
SHORT TERM...LAMERS
LONG TERM...BARRY/NAVARRO
AVIATION...GOULD
MARINE...LAMERS
FIRE WEATHER...GOULD
HYDROLOGY...BLOCK/GODSEY
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
203 PM CDT WED MAY 21 2014
.DISCUSSION...
1217 PM CDT
CANCELLED DENSE FOG EARLY...AS WELL CONFINING HIGHEST POPS FOR
SHOWERS/THUNDERSTORMS TO SOUTHERN THIRD OF CWA THROUGH THIS
AFTERNOON.
LATEST VISIBLE SATELLITE IMAGERY DEPICTING DENSE FOG WHICH HAD
BEEN SPILLING ONSHORE FOR THE LAST SEVERAL HOURS CONTINUING TO
DIMINISH. WITH THIS DIMINISHING TREND EXPECTED TO CONTINUE...THE
THREAT FOR ANY DENSE FOG OVER THE NEXT SEVERAL HOURS WILL BE OVER
THE LAKE/NEARSHORE AND SO HAVE CANCELLED THE DENSE FOG ADVISORY.
BAGGY SURFACE GRADIENT IN PLACE AS COLD FRONT MAINTAINS A SLOW
SOUTHWARD PROGRESSION THROUGH NORTH CENTRAL ILLINOIS. THIS FRONT
WILL SLOWLY PUSH SOUTH THROUGH THE AFTERNOON WITH MUCH DRIER AIR
FILTERING ON THE BACKSIDE...WITH SURFACE DEWPOINTS IN THE 50S AND
40S ACROSS NORTHWEST ILLINOIS. THIS WILL LIKELY CONFINE THE
AFTERNOON THUNDERSTORM CHANCES TO THE SOUTHERN THIRD OF THE
CWA...MAINLY SOUTH OF A PONTIAC TO VALPARAISO LINE...AS THIS FRONT
SAGS SOUTH THIS AFTERNOON. UPSTREAM MID LEVEL WAVE AND INCREASING
MID LEVEL FLOW TO THE WEST WILL APPROACH OVER THE NEXT COUPLE OF
HOURS. AS THIS OCCURS...WEAK/MODERATE CONVERGENCE ALONG FRONTAL
BOUNDARY/SURFACE TROUGH AXIS SHOULD ALLOW FOR ISOL/SCATTERED
THUNDERSTORM DEVELOPMENT WITH PEAK DEVELOPMENT EXPECTED BY MID
AFTERNOON BEFORE CHANCES DIMINISH INTO THE LATE AFTERNOON WITH
SINKING FRONT. ALTHOUGH BEST OVERALL COVERAGE SHOULD STAY SOUTH
OF THE CWA...A FEW STORMS COULD BECOME STRONG TO SEVERE ACROSS THE
SOUTHERN TIER...ESPECIALLY IN AXIS OF HIGHER
DEWPOINTS/INSTABILITY.
RODRIGUEZ
//PREV DISCUSSION...
323 AM CDT
THE FORECAST CHALLENGES CENTER ON THUNDERSTORM CHANCES TODAY AS WELL
AS THE TEMPERATURES TODAY...PARTICULARLY NEAR LAKE MICHIGAN. AFTER
THAT...THE WEATHER IS QUIESCENT WITH A GRADUAL UNSETTLING DURING THE
LATTER HALF OF THE HOLIDAY WEEKEND INTO THE FIRST HALF OF NEXT WEEK.
TODAY...
A SURFACE COOL FRONT HAS BECOME STATIONARY AND DIFFUSE ACROSS
SOUTHEAST WI...TO NEAR LASALLE/PERU...THROUGH NORTHERN MO EARLY THIS
MORNING. THIS LIKELY WILL GET NUDGED SOUTHWARD BY OUTFLOWS FROM
ISOLATED EARLY MORNING CONVECTION. A SECONDARY STRONGER COLD FRONT
WITH PRESSURE RISES ANALYZED BEHIND IT IS MOVING INTO WESTERN WI
AND NORTHERN IA EARLY THIS MORNING AND WILL OVERTAKE THE ORIGINAL
BOUNDARY AS IT MOVES THROUGH THE FORECAST AREA THIS AFTERNOON.
WITH THE WEAK WINDS AHEAD OF THIS FEATURE...LAKE-COOLED AIR AS WELL
AS POSSIBLY FOG/STRATUS MAY ADVECT INTO PORTIONS OF THE ILLINOIS
SHORE...INCLUDING DOWNTOWN CHICAGO THIS MORNING. THIS IS
CHALLENGING GIVEN LIMITED OBSERVATIONAL DATA OVER THE LAKE...BUT
THERE HAVE BEEN A HANDFUL REPORTS/OBSERVATIONS OF FOG NORTHWARD ON
THE LAKE. WILL INCLUDE AT LEAST THE MENTION OF FOG THIS MORNING
ALONG THE SHORELINE WITH THE CONTINUED HIGH DEW POINT AIR AND SOME
ONSHORE COMPONENT. IF THAT FOG/STRATUS DOES OCCUR TEMPERATURES
WILL LIKELY HOLD STEADY NEAR THE LAKE BEFORE WARMING IN THE
AFTERNOON. HAVE INITIALLY FORECAST MID/UPPER 70S NEAR THE LAKE
SHORE OF ILLINOIS AND INDIANA...BUT CONFIDENCE ON THIS IS LOW.
OTHERWISE...GIVEN THE WARM STARTING POINT AND THINNING CONVECTIVE
DEBRIS BY LATE THIS MORNING...CWA LOCATIONS AWAY FROM THE LAKE
SHOULD WARM INTO MID 80S SUCH AS YESTERDAY.
AS MIXING ENSUES TODAY...CONVERGENCE IS EXPECTED TO DEVELOP ACROSS
THE SOUTHEAST FORECAST AREA AND THAT IS WHERE THE BETTER CHANCE FOR
SCATTERED STORMS THIS AFTERNOON IS. AS THE MAIN FRONT CATCHES UP
MID-LATE AFTERNOON...MORE ROBUST CONVECTION IS ANTICIPATED TO
DEVELOP JUST SOUTHEAST OF THE FORECAST AREA. IT CANNOT BE RULED
OUT THAT AN ISOLATED STORM OR TWO DEVELOP FURTHER NORTH THIS
AFTERNOON...INCLUDING THE CHICAGO METRO AREA...AS THE PRIMARY
FRONT MOVES INTO A HIGH PWAT/MODESTLY UNSTABLE ATMOSPHERE. NOT
ENOUGH CONFIDENCE TO MENTION IN THE FORECAST AT THIS TIME. FOR THE
SOUTHEAST FORECAST AREA THIS AFTERNOON...DEEP LAYER SHEAR AND
CONTINUED MODEST TO STRONG INSTABILITY WOULD SUPPORT A CONDITIONAL
THREAT FOR DISCRETE SEVERE STORMS INITIALLY CAPABLE OF MAINLY
LARGE HAIL IF THEY CAN DEVELOP BEFORE THE BEST CONVERGENCE CLEARS
THE FORECAST AREA. RIGHT NOW INITIATION IS EXPECTED BETWEEN 1-4 PM
AND THESE STORMS LIKELY MOVING OUT OF THE FORECAST AREA BY 4-7 PM.
THURSDAY THROUGH SATURDAY...
AN UPPER CLOSED LOW ACROSS THE SOUTHWEST CONUS THIS MORNING WILL
MOVE VERY LITTLE THROUGH THE NEXT FEW DAYS. IN RESPONSE TO
THIS...UPSTREAM RIDGING ACROSS THE PLAINS IS FORECAST...AND BEING
UNDER THE ANTICYCLONIC SIDE OF THE JET FOR THESE FEW DAYS IT LOOKS
QUIET. WHILE THERE MAY BE SOME HIGH CLOUDS OVERALL IT LOOKS
MOSTLY CLEAR IN MANY AREAS. THE SURFACE PATTERN OF A HIGH CENTER
IN THE WESTERN GREAT LAKES SUPPORTS ONSHORE FLOW. LOCAL
CLIMATOLOGICAL RESEARCH WITH ONSHORE FLOW FOR LATE MAY SUPPORTS
AROUND A 10-12 DEGREE TEMPERATURE DIFFERENCE FROM DOWNTOWN TO
OUTLYING SUBURBS WITH ALL DAY ONSHORE FLOW AND HAVE STUCK CLOSE TO
THAT. TEMPERATURES LOOK TO BE NEAR/SLIGHTLY BELOW NORMAL.
SUNDAY THROUGH TUESDAY...
THE CLOSED UPPER LOW IS FORECAST TO MOVE EAST DURING THIS TIME AND
GRADUALLY WEAKEN AS IT IS CUT OFF FROM THE MAIN JET.
HOWEVER...HEIGHT FALLS FROM THIS FEATURE ARE EXPECTED TO INCH
THEIR WAY OVER THE AREA DURING THIS TIME. WITH A DESTABILIZING
LOWER ATMOSPHERE...THUNDER CHANCES SLOWLY INCREASE...BUT MAINLY
WEST AND NORTH OF THE REGION THROUGH THE HOLIDAY. CONTINUE SMALL
CHANCES WITHIN THE FORECAST...WHICH WOULD BE MAINLY ASSOCIATED
WITH ELEVATED WARM AIR ADVECTION/POSSIBLE SHORT WAVE IMPULSES. SO
CONFIDENCE IS PRETTY LOW ON STORMS OCCURRING AT THIS TIME. THE
850MB TEMPERATURES AND LOW-LEVEL TRAJECTORIES SUPPORT MID 80S ON
THE HOLIDAY AND POTENTIALLY TUESDAY AS WELL...IF INDEED CONVECTION
AND ITS DEBRIS STAYS MAINLY WEST AND NORTH.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LGT/VRBL WINDS RETURNING TO NWLY BY EARLY AFTERNOON WITH
DAYTIME WARMING/MIXING.
* LAKE BREEZE MOVING INLAND BY LATE MORNING/EARLY AFTERNOON
SHIFTING WINDS TO NELY.
KREIN
//DISCUSSION...UPDATED 18Z...
A LAKE ENHANCED FRONT HAS PUSHED PUSHED WELL INLAND AND IS
DISSIPATING WITH DAYTIME DAYTIME WARMING/MIXING...WITH WINDS
RETURNING TO SYNOPTICALLY NWLY. GYY WILL BE THE ONLY SITE
MAINTAINING SOME LAKE INFLUENCE...BUT LATEST VIS SATELLITE IMAGERY
INDICATES THAT THE FOG IS REMAINING OFF SHORE WHILE THINNING...SO
EVEN THERE...CONDITIONS SHOULD SOON RETURN TO VFR. CONDITIONS WILL
BE QUIET FOR THE REMAINDER OF THE EVENING AND OVERNIGHT AS HIGH
PRESSURE SPREADS ACROSS THE MIDDLE AND UPPER MISSISSIPPI VALLEY.
THE MAIN ISSUE FOR TOMORROW WILL BE A WIND SHIFT ASSOCIATED WITH
LAKE BREEZE DEVELOPMENT. WITH THE HIGH SPREADING OVER THE WESTERN
GREAT LAKES REGION...THE SFC PRESSURE GRADIENT WILL BE VERY
WEAK...SO LAKE BREEZE DEVELOPMENT IS LIKELY...TURNING WINDS NLY AT
GYY AND NELY AT ORD/MDW. TIMING WILL BE THE MAIN QUESTION...THOUGH
THE LATEST HIGH RESOLUTION GUIDANCE SUGGESTS THAT MDW/GYY SHOULD
TURN BY LATE MORNING AND ORD BY EARLY AFTERNOON. DPA/RFD WILL
LIKELY REMAIN UNAFFECTED WITH WINDS REMAINING NWLY AT LESS THAN 10
KT. NO CIG/VIS RESTRICTIONS ARE EXPECTED THROUGH THE PERIOD.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN WIND TRENDS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY...VFR. EARLY LAKE BREEZE WIND SHIFT TO NORTHEAST LIKELY.
SATURDAY...VFR. EAST NORTHEAST WINDS.
SUNDAY...VFR.
MONDAY...PRIMARILY VFR. SLIGHT CHANCE TSRA.
TUESDAY...VFR.
RC
&&
.MARINE...
202 PM CDT
A FAIRLY BROAD AREA OF LOW PRESSURE IS POSITIONED OVER THE WESTERN
GREAT LAKES AND WILL MOVE EASTWARD TONIGHT AND THURSDAY. A COLD
FRONTAL BOUNDARY WILL MOVE ACROSS THE LAKE THIS EVENING WHICH WILL
BRING A STEADIER NORTHWEST WIND AS WELL AS DRIER AIR...WHICH WILL
WORK TO ERODE THE REMAINING FOG ACROSS THE OPEN WATERS LATE THIS
AFTERNOON AND EARLY THIS EVENING. GENERALLY LIGHT NORTHERLY FLOW
WILL REMAIN ACROSS THE LAKE INTO THE WEEKEND AS HIGH PRESSURE MOVES
OVER LAKE MICHIGAN. A SHIFT TO ONSHORE WINDS IS LIKELY THURSDAY AND
FRIDAY...WITH MORE VARIABILITY SATURDAY AS THE HIGH MOVES OVERHEAD.
A SHIFT TO A STEADIER SOUTHERLY WIND IS EXPECTED SATURDAY NIGHT AS
THE HIGH MOVES OFF TO THE EAST. LOW PRESSURE IS FORECAST TO TRACK
NORTHEAST ACROSS THE UPPER MIDWEST SUNDAY NIGHT AND MONDAY WHICH
WILL TIGHTEN THE PRESSURE GRADIENT LEADING TO A BIT OF AN INCREASE
IN WIND SPEEDS BUT STABLE AIR OVER THE LAKE SHOULD KEEP GUST
FREQUENCY LOW.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-
LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ743-LMZ744-
LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-
LMZ878 UNTIL 3 PM WEDNESDAY.
&&
$$
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
158 PM CDT Wed May 21 2014
.DISCUSSION...
ISSUED 158 PM CDT Wed May 21 2014
Severe storm potential will highlight the short term. A brief period
of cooler temps will close out the week, before a long wave ridge
builds into our area for the weekend. As that ridge slides east
later this weekend, a few late afternoon thunderstorms could bubble
up in our western areas on Sunday and Memorial Day as moisture
and heat return to IL.
SHORT TERM...Tonight through Saturday.
The initial severe thunderstorm watch #164 does not include any of
IL, but we still expect some thunderstorms to develop along the
cold front in IL later this afternoon. At 18z/1 pm, the front
extended on a line through Bloomington and Rushville. Surface
dewpoints ahead of the front had climbed into the mid 60s, with
air temps in the mid to upper 80s. Surface based CAPEs were in the
2800-3300 J/kg, with 0-6km wind shear of 35-50kts. LAPS soundings
were indicating little to no cap above the LCL. We should see some
of the storms become strong in our area, with very large hail the
main hazard and damaging winds possible. Supercell formation
appears likely at the onset, with the better chances of linear
progression most likely occurring after the storms advance eastward
into Indiana. The cumulus field on across C IL appears to be
deepening, with some towering cu. A watch may be needed in IL in
the 2-3 pm time frame.
Will maintain high chance PoPs the rest of the afternoon and into
the evening, as coverage could be limited by breaks in the line of
storm cells that develop.
The latest 4km model HRRR output shows rather limited coverage of
storms on an E-W line along and south of I-72, with storms
generally south of our CWA by 06z/1am. Will keep PoPs after
midnight limited to the far southern areas.
The cold front forward progress will slow down and stall near the
southern tip of IL, keeping shower and storm chances close by to
the south and west of our forecast area. We held onto a narrow
area of slight chance PoPs along our far southern counties on
Thurs and Thur night as a result.
Surface high pressure and a building ridge aloft should help keep
our area rain free on Friday and Saturday as moisture return will
be primarily into the Missouri and areas west.
A brief cooler period will occur from Thursday into Friday behind
today`s cold front. Highs will still linger right around normal in
the mid to upper 70s. Saturday will see temps begin a warming
trend, but highs will still remain mainly in the upper 70s.
LONG TERM...Sunday through Wednesday.
Warming through a deeper layer will develop on Sunday as the
surface ridge axis slides east of Illinois and southerly return
flow increases. Low and mid level moisture content will increase as
well, with dewpoints returning to the 60s west of I-55 on Sunday.
Thunderstorm chances will be mainly west of our forecast area, in
the vicinity of a surface trough along the Mississippi river
valley. Instability params support storm progression into western
IL, so we went with low chance and slight chance PoPs west of
I-55. A weakening of the surface trough and increasing cap
strength on Memorial Day may help to diminish storm chances a
little. However, an weak disturbance in the 400-600 mb layer
could cause a few isolated storms. We went with slight chance PoPs
NW of a line from Springfield to Champaign, for mainly late
afternoon/early evening storm potential. Most areas should remain
dry though. Memorial Day looks to be the warmest day of the
holiday weekend, as highs return to the mid 80s. Dewpoints in the
low to mid 60s will make it feel a bit humid outside as well.
On Tuesday and Wednesday, the ECMWF, and to some extent the GFS,
progress an upper low into the ridge, triggering a wider coverage
of showers and storms. Low chance PoPs were included for all our
counties Tuesday and Wednesday to account for the relative
agreement on a wetter solution. Increasing clouds and rain
potential should keep high temps in the 70s both days.
Shimon
&&
.AVIATION...
ISSUED 1247 PM CDT Wed May 21 2014
A frontal boundary will sag south into central IL this afternoon
and evening. Some isolated to scatted storm are expected to
develop this afternoon along and ahead of the front, though
coverage is expected to be too low to include in TAFS beyond VCTS.
If a terminal is impacted by TSRA, short reduction to IFR
possible with brief strong/gusty winds. Otherwise VFR expected
through Thu AM with diurnal cumulus this afternoon and scattered
mid clouds overnight. W/SW winds ahead of the front will veer to
the north this evening after the frontal passage, generally
remaining under 10 kts.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
425 PM EDT WED MAY 21 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 316 PM EDT WED MAY 21 2014
A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT BRINGING A CHANCE
FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL THEN BUILD IN AND
PROVIDE DRY CONDITIONS THROUGH MONDAY. AN UPPER LEVEL SYSTEM COULD
BRING SOME RAIN AGAIN TUESDAY INTO WEDNESDAY OF NEXT WEEK. FOR THE
MOST PART NEAR TO ABOVE AVERAGE TEMPERATURES CAN BE EXPECTED.
&&
.NEAR TERM /REST OF THIS AFTERNOON AND TONIGHT/...
ISSUED AT 316 PM EDT WED MAY 21 2014
SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS AFTERNOON
AHEAD OF AN UPPER WAVE. ATMOSPHERE CONTINUES TO BE FAVORABLE FOR
SEVERE WEATHER SO EXPECT SOME SEVERE STORMS WITH LARGE HAIL AND
DAMAGING WINDS LATE THIS AFTERNOON INTO EARLY EVENING.
BASED ON CURRENT DEVELOPMENT AND RAPID UPDATE MODELS...SOUTHEASTERN
FORECAST AREA LOOKS TO HAVE THE MOST COVERAGE LATER THIS AFTERNOON.
COLD FRONT IS STILL TO THE NORTHWEST...AND AS IT SLIDES DOWN THIS
EVENING AND TONIGHT ADDITIONAL STORMS ARE STILL POSSIBLE. WILL KEEP
CHANCE POPS THIS EVENING ALL AREAS AND THEN DECREASE THEM FROM NORTH
TO SOUTH AS THE NIGHT PROGRESSES /AND COLD FRONT SLIDES SOUTH/.
FOR TEMPERATURES STUCK WITH A MODEL BLEND.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 316 PM EDT WED MAY 21 2014
FOCUS IS ON ANY CHANCES FOR RAIN EARLY OTHERWISE ON TEMPERATURES.
MODELS ARE CLOSE ENOUGH THAT A BLEND CAN BE USED.
REAL PUSH OF COLDER AIR MOVES IN LATER DURING THE DAY ON THURSDAY
INTO THURSDAY EVENING. SOME MODELS TRY TO DEVELOP RAIN ACROSS THE
SOUTHWEST FORECAST AREA THURSDAY NIGHT AS A WAVE MOVES THROUGH NEAR
THE BOUNDARY...BUT BELIEVE THEY ARE OVERDOING IT AS SREF AND GFS
ENSEMBLES ARE DRY. WILL KEEP FORECAST DRY.
OTHERWISE HIGH PRESSURE WILL KEEP DRY CONDITIONS THROUGH THE SHORT
TERM. COLDER AIR MOVES IN BRIEFLY ON FRIDAY WITH A LITTLE BELOW
AVERAGE TEMPERATURES...BUT TEMPERATURE BEGIN REBOUNDING ON SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 316 PM EDT WED MAY 21 2014
MODELS ARE CLOSE ENOUGH THAT THE ALLBLEND INITIALIZATION CAN BE
USED.
HIGH PRESSURE AND UPPER RIDGE WILL KEEP DRY AND WARM CONDITIONS
THROUGH MONDAY. AN UPPER TROUGH TO THE WEST COULD BRING SOME SHOWERS
AND ISOLATED STORMS TUESDAY AND WEDNESDAY. TEMPERATURES WILL COOL
DOWN AGAIN ON WEDNESDAY.
&&
.AVIATION /DISCUSSION FOR THE 212100Z KIND TAF UPDATE/...
ISSUED AT 425 PM EDT WED MAY 21 2014
BROKEN LINE OF CONVECTION CURRENTLY EXTENDS FROM CENTRAL INDIANA
BACK INTO ILLINOIS NEAR A SURFACE BOUNDARY. SOME CONVECTION ALSO
DEVELOPING AHEAD OF AN UPPER WAVE PUSHING TOWARDS SOUTHWEST
ILLINOIS. SHORT TERM MODEL DATA SUGGEST THIS UPPER WAVE WILL BE
PASSING OVER THE KIND VICINITY TOWARDS 220100Z-220200Z...SO THINK
THE THREAT FOR CONVECTION WILL REMAIN HIGH UNTIL THAT TIME. WILL
EXTEND THE THUNDERSTORM THREAT IN TIME A FEW MORE HOURS ON THE
UPDATE. VARIABLE AND GUSTY SURFACE WIND AND HAIL ARE POSSIBLE WITH
THE HEAVIER CELLS.
PREVIOUS DISCUSSION FOLLOWS.
MAINLY VFR CONDITIONS EXPECTED THIS FORECAST PERIOD...HOWEVER
BRIEF MVFR OR IFR CONDITIONS WILL BE POSSIBLE WITH ANY TSRA
DEVELOPMENT LATE THIS AFTERNOON.
SURFACE AND RADAR ANALYSIS REVEALS A SURFACE BOUNDARY JUST NORTH
OF LAF AND MIE...AND SCT RWS AND TSRAS WERE DEVELOPING ALONG THE
BOUNDARY. HRRR SUGGESTS FURTHER CONVECTIVE DEVELOPMENT THIS
AFTERNOON WITH SOUTHWARD PROPAGATION ACROSS THE TAF SITES THROUGH
THE AFTERNOON. GIVEN THE FAVORABLE CONVECTIVE INSTABILITY HAVE
INCLUDED A TEMPO PERIOD FOR TSRA DURING THE LATE AFTERNOON EARLY
EVE AT THE TAF SITES.
HIGH DEW POINTS ARE EXPECTED TO LINGER THROUGH THE OVERNIGHT. THIS
COMBINED WITH RECENT RAIN AND LIGHT WINDS MAY RESULT IN SOME MVFR
FOG LATE TONIGHT. ANY FOG DEVELOPMENT WILL QUICKLY DISSIPATE AFTER
14Z THURSDAY AS DAYTIME HEATING RESUMES.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....JP/50
AVIATION...JP/JAS
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
316 PM EDT WED MAY 21 2014
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM...AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 316 PM EDT WED MAY 21 2014
A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT BRINGING A CHANCE
FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL THEN BUILD IN AND
PROVIDE DRY CONDITIONS THROUGH MONDAY. AN UPPER LEVEL SYSTEM COULD
BRING SOME RAIN AGAIN TUESDAY INTO WEDNESDAY OF NEXT WEEK. FOR THE
MOST PART NEAR TO ABOVE AVERAGE TEMPERATURES CAN BE EXPECTED.
&&
.NEAR TERM /REST OF THIS AFTERNOON AND TONIGHT/...
ISSUED AT 316 PM EDT WED MAY 21 2014
SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS AFTERNOON
AHEAD OF AN UPPER WAVE. ATMOSPHERE CONTINUES TO BE FAVORABLE FOR
SEVERE WEATHER SO EXPECT SOME SEVERE STORMS WITH LARGE HAIL AND
DAMAGING WINDS LATE THIS AFTERNOON INTO EARLY EVENING.
BASED ON CURRENT DEVELOPMENT AND RAPID UPDATE MODELS...SOUTHEASTERN
FORECAST AREA LOOKS TO HAVE THE MOST COVERAGE LATER THIS AFTERNOON.
COLD FRONT IS STILL TO THE NORTHWEST...AND AS IT SLIDES DOWN THIS
EVENING AND TONIGHT ADDITIONAL STORMS ARE STILL POSSIBLE. WILL KEEP
CHANCE POPS THIS EVENING ALL AREAS AND THEN DECREASE THEM FROM NORTH
TO SOUTH AS THE NIGHT PROGRESSES /AND COLD FRONT SLIDES SOUTH/.
FOR TEMPERATURES STUCK WITH A MODEL BLEND.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 316 PM EDT WED MAY 21 2014
FOCUS IS ON ANY CHANCES FOR RAIN EARLY OTHERWISE ON TEMPERATURES.
MODELS ARE CLOSE ENOUGH THAT A BLEND CAN BE USED.
REAL PUSH OF COLDER AIR MOVES IN LATER DURING THE DAY ON THURSDAY
INTO THURSDAY EVENING. SOME MODELS TRY TO DEVELOP RAIN ACROSS THE
SOUTHWEST FORECAST AREA THURSDAY NIGHT AS A WAVE MOVES THROUGH NEAR
THE BOUNDARY...BUT BELIEVE THEY ARE OVERDOING IT AS SREF AND GFS
ENSEMBLES ARE DRY. WILL KEEP FORECAST DRY.
OTHERWISE HIGH PRESSURE WILL KEEP DRY CONDITIONS THROUGH THE SHORT
TERM. COLDER AIR MOVES IN BRIEFLY ON FRIDAY WITH A LITTLE BELOW
AVERAGE TEMPERATURES...BUT TEMPERATURE BEGIN REBOUNDING ON SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 316 PM EDT WED MAY 21 2014
MODELS ARE CLOSE ENOUGH THAT THE ALLBLEND INITIALIZATION CAN BE
USED.
HIGH PRESSURE AND UPPER RIDGE WILL KEEP DRY AND WARM CONDITIONS
THROUGH MONDAY. AN UPPER TROUGH TO THE WEST COULD BRING SOME SHOWERS
AND ISOLATED STORMS TUESDAY AND WEDNESDAY. TEMPERATURES WILL COOL
DOWN AGAIN ON WEDNESDAY.
&&
.AVIATION /DISCUSSION FOR THE 211800Z TAFS/...
ISSUED AT 1234 PM EDT WED MAY 21 2014
MAINLY VFR CONDITIONS EXPECTED THIS FORECAST PERIOD...HOWEVER
BRIEF MVFR OR IFR CONDITIONS WILL BE POSSIBLE WITH ANY TSRA
DEVELOPMENT LATE THIS AFTERNOON.
SURFACE AND RADAR ANALYSIS REVEALS A SURFACE BOUNDARY JUST NORTH
OF LAF AND MIE...AND SCT RWS AND TSRAS WERE DEVELOPING ALONG THE
BOUNDARY. HRRR SUGGESTS FURTHER CONVECTIVE DEVELOPMENT THIS
AFTERNOON WITH SOUTHWARD PROPAGATION ACROSS THE TAF SITES THROUGH
THE AFTERNOON. GIVEN THE FAVORABLE CONVECTIVE INSTABILITY HAVE
INCLUDED A TEMPO PERIOD FOR TSRA DURING THE LATE AFTERNOON EARLY
EVE AT THE TAF SITES.
HIGH DEW POINTS ARE EXPECTED TO LINGER THROUGH THE OVERNIGHT. THIS
COMBINED WITH RECENT RAIN AND LIGHT WINDS MAY RESULT IN SOME MVFR
FOG LATE TONIGHT. ANY FOG DEVELOPMENT WILL QUICKLY DISSIPATE AFTER
14Z THURSDAY AS DAYTIME HEATING RESUMES.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....JP/50
AVIATION...JP
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1251 PM EDT WED MAY 21 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 325 AM EDT WED MAY 21 2014
SCATTERED SHOWERS AND SEVERE THUNDERSTORMS WILL BE POSSIBLE TODAY
AND THIS EVENING AS A COLD FRONT SLIDES ACROSS CENTRAL INDIANA.
TEMPS WILL DECREASE A BIT DURING THE SHORT TERM PERIOD IN THE WAKE
OF COLD FRONT...BUT CONDITIONS WILL BE DRY THROUGH NEXT TUESDAY
WITH HIGH PRESSURE OVER THE AREA. THE NEXT CHANCE FOR SHOWERS AND
THUNDERSTORMS WILL BE NEXT TUESDAY NIGHT/WEDNESDAY WHEN THE NEXT
UPPER LOW AND VORT MAX ENTER THE REGION.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 950 AM EDT WED MAY 21 2014
FORECAST IS PRETTY MUCH ON TRACK. LOWERED POPS THIS MORNING ACROSS
THE SOUTHWEST FORECAST AREA SINCE THUNDERSTORMS SHOULD BE CLOSER TO
THE BOUNDARY ACROSS NORTHERN INDIANA. LEFT POPS ALONE THIS
AFTERNOON. STORM PREDICTION CENTER STILL INDICATES A RISK FOR SEVERE
STORMS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY THREATS.
LEFT TEMPERATURES ALONE FOR NOW AND WILL SEE IF CONVECTION OR CLOUDS
FROM CONVECTION REQUIRE A CHANGE LATER THIS AFTERNOON.
PREVIOUS DISCUSSION FOLLOWS...
THE MAIN FOCUS OF THE NEAR TERM IS THE THREAT FOR SEVERE WEATHER.
SPC CONTINUES TO KEEP ALL OF CENTRAL INDIANA UNDER A SLIGHT RISK
FOR DAY 1.
RIDGE ALOFT WILL BREAK DOWN AS UPPER LEVEL LOW ENTERS THE GREAT
LAKES REGION TODAY. MEANWHILE...A COLD FRONT AT THE SURFACE WILL
TRACK ACROSS CENTRAL INDIANA...TRIGGERING SHOWERS AND
THUNDERSTORMS ALONG AND AHEAD OF IT. MLCAPES REMAIN IMPRESSIVE
ACROSS THE FORECAST AREA IN THE 2000 TO 3000 J/KG RANGE. MID LEVEL
LAPSE RATES WILL APPROACH THE 7C MARK BY THIS EVENING. THIS MEANS
THE SOUTH/SOUTHEASTERN PORTIONS OF FORECAST AREA WILL HAVE HIGHEST
THREAT FOR SEVERE DEVELOPMENT WITH BEST INSTABILITY OF THE DAY.
LARGE HAIL WILL BE A HUGE THREAT. IN ADDITION...STRONG WESTERLY SPEED
SHEAR WILL BE CONDUCIVE TO DAMAGING WINDS. HIGHLIGHTED THE
SOUTHEAST QUADRANT OF FORECAST AREA BY CARRYING LIKELY POPS DURING
THIS AFTERNOON AND EVENING. LATEST MODELS HAVE COLD FRONT ENTERING
THE NORTHWESTERN COUNTIES AROUND WED 18Z AND ARE TRENDING TOWARD A
VERY SLOW PROGRESSION OF THE FRONT THROUGH THE DAY.
TEMPS...TRENDED SLIGHTLY ABOVE GUIDANCE FOR TODAY. WARM
SOUTHWESTERLY FLOW AHEAD OF COLD FRONT SHOULD RESULT IN HIGH TEMPS
TOPPING OFF IN THE LOW TO MID 80S.
CURRENTLY...TEMPS ACROSS THE AREA ARE GENERALLY IN THE UPPER 70S
WITH DEWPOINTS IN THE UPPER 50S/LOW 60S. WINDS ARE SOUTHWESTERLY
AT 5 TO 10 MPH AND GUSTING TO 18 MPH.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
ISSUED AT 325 AM EDT WED MAY 21 2014
HELD ONTO WIDESPREAD PRECIP CHANCES UP TO THU 06Z ACROSS MOST OF
FORECAST AREA DUE TO THE SLOW PROGRESSION OF COLD FRONT AND
LINGERING MOISTURE/ISENTROPIC LIFT. ANTICIPATE QUICK CLEARING
AFTER THAT AND THEN A DRY FORECAST THROUGH THE REMAINDER OF SHORT
TERM PERIOD AS HIGH PRESSURE BUILDS BACK INTO THE REGION.
STUCK CLOSE TO GUIDANCE IN REGARD TO TEMPS FOR DURATION OF SHORT
TERM PERIOD. TEMPS BECOME CLOSER TO NORMAL IN WAKE OF
AFOREMENTIONED COLD FRONT...AND MODELS SEEM TO BE PICKING UP ON
THE TRANSITION WELL. HIGHS WILL GENERALLY BE IN THE LOW 70S OVER
THE NORTHERN COUNTIES...TO MID TO UPPER 70S ACROSS THE SOUTHERN
COUNTIES. OVERNIGHT LOWS WILL DIP BACK INTO THE 50S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 237 PM EDT TUE MAY 20 2014
MAIN FOCUS ON THE EXTENDED WILL BE ON TEMPERATURES AS MEMORIAL
DAY WEEKEND IS LOOKING VERY PROMISING FOR OUTDOOR ACTIVITIES
ACROSS CENTRAL INDIANA.
THE MOST CONSISTENT ECMWF AND ECMWF ENSEMBLE MEANS ALONG WITH THE
00Z GFS START THE EXTENDED OFF WITH BROAD SURFACE HIGH PRESSURE
ACROSS THE GREAT LAKES AND OHIO VALLEY AND A SHARP UPPER RIDGE
ACROSS THE MISSISSIPPI VALLEY. THE SURFACE HIGH WILL SHIFT EAST TO
THE APPALACHIANS SATURDAY NIGHT AND TO THE EASTERN SEABOARD SUNDAY.
THIS WILL ALLOW FOR A MODEST SOUTHERLY FLOW OF WARMER AIR INTO THE
THE OHIO VALLEY THROUGH NEXT WEEK.
EXPECT THE WEEKEND TO BE DRY WITH A FEW THUNDERSTORMS POSSIBLE EARLY
NEXT WEEK WITH LOW LEVEL MOISTURE INCREASING AND IMPULSES ROUNDING
THE BASE OF AN UPSTREAM UPPER LOW ACROSS THE CENTRAL PLAINS. FOR
NOW...WILL KEEP MEMORIAL DAY DRY AND GO WITH SMALL THUNDERSTORM
CHANCES BY TUESDAY.
REGIONAL ALLBLEND TEMPERATURES LOOK REASONABLE GIVEN THE SOUTHERLY
FLOW AND UPPER RIDGE PATTERN WITH AFTERNOON HIGHS STARTING OFF NEAR
NORMAL IN THE 70S ON SATURDAY AND CLIMBING TO THE MID 80S BY MONDAY.
&&
.AVIATION /DISCUSSION FOR THE 211800Z TAFS/...
ISSUED AT 1234 PM EDT WED MAY 21 2014
MAINLY VFR CONDITIONS EXPECTED THIS FORECAST PERIOD...HOWEVER
BRIEF MVFR OR IFR CONDITIONS WILL BE POSSIBLE WITH ANY TSRA
DEVELOPMENT LATE THIS AFTERNOON.
SURFACE AND RADAR ANALYSIS REVEALS A SURFACE BOUNDARY JUST NORTH
OF LAF AND MIE...AND SCT RWS AND TSRAS WERE DEVELOPING ALONG THE
BOUNDARY. HRRR SUGGESTS FURTHER CONVECTIVE DEVELOPMENT THIS
AFTERNOON WITH SOUTHWARD PROPAGATION ACROSS THE TAF SITES THROUGH
THE AFTERNOON. GIVEN THE FAVORABLE CONVECTIVE INSTABILITY HAVE
INCLUDED A TEMPO PERIOD FOR TSRA DURING THE LATE AFTERNOON EARLY
EVE AT THE TAF SITES.
HIGH DEW POINTS ARE EXPECTED TO LINGER THROUGH THE OVERNIGHT. THIS
COMBINED WITH RECENT RAIN AND LIGHT WINDS MAY RESULT IN SOME MVFR
FOG LATE TONIGHT. ANY FOG DEVELOPMENT WILL QUICKLY DISSIPATE AFTER
14Z THURSDAY AS DAYTIME HEATING RESUMES.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...TDUD/50
SHORT TERM...TDUD
LONG TERM....MK
AVIATION...JP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1040 AM EDT WED MAY 21 2014
.UPDATE...
AVIATION SECTIONS UPDATED.
&&
.SYNOPSIS...
ISSUED AT 325 AM EDT WED MAY 21 2014
SCATTERED SHOWERS AND SEVERE THUNDERSTORMS WILL BE POSSIBLE TODAY
AND THIS EVENING AS A COLD FRONT SLIDES ACROSS CENTRAL INDIANA.
TEMPS WILL DECREASE A BIT DURING THE SHORT TERM PERIOD IN THE WAKE
OF COLD FRONT...BUT CONDITIONS WILL BE DRY THROUGH NEXT TUESDAY
WITH HIGH PRESSURE OVER THE AREA. THE NEXT CHANCE FOR SHOWERS AND
THUNDERSTORMS WILL BE NEXT TUESDAY NIGHT/WEDNESDAY WHEN THE NEXT
UPPER LOW AND VORT MAX ENTER THE REGION.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 950 AM EDT WED MAY 21 2014
FORECAST IS PRETTY MUCH ON TRACK. LOWERED POPS THIS MORNING ACROSS
THE SOUTHWEST FORECAST AREA SINCE THUNDERSTORMS SHOULD BE CLOSER TO
THE BOUNDARY ACROSS NORTHERN INDIANA. LEFT POPS ALONE THIS
AFTERNOON. STORM PREDICTION CENTER STILL INDICATES A RISK FOR SEVERE
STORMS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY THREATS.
LEFT TEMPERATURES ALONE FOR NOW AND WILL SEE IF CONVECTION OR CLOUDS
FROM CONVECTION REQUIRE A CHANGE LATER THIS AFTERNOON.
PREVIOUS DISCUSSION FOLLOWS...
THE MAIN FOCUS OF THE NEAR TERM IS THE THREAT FOR SEVERE WEATHER.
SPC CONTINUES TO KEEP ALL OF CENTRAL INDIANA UNDER A SLIGHT RISK
FOR DAY 1.
RIDGE ALOFT WILL BREAK DOWN AS UPPER LEVEL LOW ENTERS THE GREAT
LAKES REGION TODAY. MEANWHILE...A COLD FRONT AT THE SURFACE WILL
TRACK ACROSS CENTRAL INDIANA...TRIGGERING SHOWERS AND
THUNDERSTORMS ALONG AND AHEAD OF IT. MLCAPES REMAIN IMPRESSIVE
ACROSS THE FORECAST AREA IN THE 2000 TO 3000 J/KG RANGE. MID LEVEL
LAPSE RATES WILL APPROACH THE 7C MARK BY THIS EVENING. THIS MEANS
THE SOUTH/SOUTHEASTERN PORTIONS OF FORECAST AREA WILL HAVE HIGHEST
THREAT FOR SEVERE DEVELOPMENT WITH BEST INSTABILITY OF THE DAY.
LARGE HAIL WILL BE A HUGE THREAT. IN ADDITION...STRONG WESTERLY SPEED
SHEAR WILL BE CONDUCIVE TO DAMAGING WINDS. HIGHLIGHTED THE
SOUTHEAST QUADRANT OF FORECAST AREA BY CARRYING LIKELY POPS DURING
THIS AFTERNOON AND EVENING. LATEST MODELS HAVE COLD FRONT ENTERING
THE NORTHWESTERN COUNTIES AROUND WED 18Z AND ARE TRENDING TOWARD A
VERY SLOW PROGRESSION OF THE FRONT THROUGH THE DAY.
TEMPS...TRENDED SLIGHTLY ABOVE GUIDANCE FOR TODAY. WARM
SOUTHWESTERLY FLOW AHEAD OF COLD FRONT SHOULD RESULT IN HIGH TEMPS
TOPPING OFF IN THE LOW TO MID 80S.
CURRENTLY...TEMPS ACROSS THE AREA ARE GENERALLY IN THE UPPER 70S
WITH DEWPOINTS IN THE UPPER 50S/LOW 60S. WINDS ARE SOUTHWESTERLY
AT 5 TO 10 MPH AND GUSTING TO 18 MPH.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
ISSUED AT 325 AM EDT WED MAY 21 2014
HELD ONTO WIDESPREAD PRECIP CHANCES UP TO THU 06Z ACROSS MOST OF
FORECAST AREA DUE TO THE SLOW PROGRESSION OF COLD FRONT AND
LINGERING MOISTURE/ISENTROPIC LIFT. ANTICIPATE QUICK CLEARING
AFTER THAT AND THEN A DRY FORECAST THROUGH THE REMAINDER OF SHORT
TERM PERIOD AS HIGH PRESSURE BUILDS BACK INTO THE REGION.
STUCK CLOSE TO GUIDANCE IN REGARD TO TEMPS FOR DURATION OF SHORT
TERM PERIOD. TEMPS BECOME CLOSER TO NORMAL IN WAKE OF
AFOREMENTIONED COLD FRONT...AND MODELS SEEM TO BE PICKING UP ON
THE TRANSITION WELL. HIGHS WILL GENERALLY BE IN THE LOW 70S OVER
THE NORTHERN COUNTIES...TO MID TO UPPER 70S ACROSS THE SOUTHERN
COUNTIES. OVERNIGHT LOWS WILL DIP BACK INTO THE 50S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 237 PM EDT TUE MAY 20 2014
MAIN FOCUS ON THE EXTENDED WILL BE ON TEMPERATURES AS MEMORIAL
DAY WEEKEND IS LOOKING VERY PROMISING FOR OUTDOOR ACTIVITIES
ACROSS CENTRAL INDIANA.
THE MOST CONSISTENT ECMWF AND ECMWF ENSEMBLE MEANS ALONG WITH THE
00Z GFS START THE EXTENDED OFF WITH BROAD SURFACE HIGH PRESSURE
ACROSS THE GREAT LAKES AND OHIO VALLEY AND A SHARP UPPER RIDGE
ACROSS THE MISSISSIPPI VALLEY. THE SURFACE HIGH WILL SHIFT EAST TO
THE APPALACHIANS SATURDAY NIGHT AND TO THE EASTERN SEABOARD SUNDAY.
THIS WILL ALLOW FOR A MODEST SOUTHERLY FLOW OF WARMER AIR INTO THE
THE OHIO VALLEY THROUGH NEXT WEEK.
EXPECT THE WEEKEND TO BE DRY WITH A FEW THUNDERSTORMS POSSIBLE EARLY
NEXT WEEK WITH LOW LEVEL MOISTURE INCREASING AND IMPULSES ROUNDING
THE BASE OF AN UPSTREAM UPPER LOW ACROSS THE CENTRAL PLAINS. FOR
NOW...WILL KEEP MEMORIAL DAY DRY AND GO WITH SMALL THUNDERSTORM
CHANCES BY TUESDAY.
REGIONAL ALLBLEND TEMPERATURES LOOK REASONABLE GIVEN THE SOUTHERLY
FLOW AND UPPER RIDGE PATTERN WITH AFTERNOON HIGHS STARTING OFF NEAR
NORMAL IN THE 70S ON SATURDAY AND CLIMBING TO THE MID 80S BY MONDAY.
&&
.AVIATION /DISCUSSION FOR THE 211500Z IND TAF UPDATE/...
ONGOING TAFS IN GOOD SHAPE. VFR CONDITIONS WILL CONTINUE INTO THE
AFTERNOON. CONVECTIVE TEMPS SHOULD BE REACHED EARLY THIS
AFTERNOON. HRRR CONTINUES TO SUGGEST 19Z AS CONVECTIVE INITIATION
TIME. THUS HAVE AS TRIMMED VCTS MENTION TO AFTER 18Z.
PREVIOUS DISCUSSION BELOW
/DISCUSSION FOR THE 211200Z TAF ISSUANCE/...
ISSUED AT 632 AM EDT WED MAY 21 2014
WITH STRONG INSTABILITY AND SUFFICIENT MOISTURE ALONG AND AHEAD OF
AN ADVANCING COLD FRONT...EXPECT STRONG CONVECTION TO INITIATE
MAINLY AFTER 18Z AS CONVECTIVE TEMPERATURES IN THE LOWER 80S ARE
REACHED. THE FRONT SHOULD REACH LAF NEAR 22Z...IND AND HUF NEAR 06Z
THURSDAY AND BMG TOWARD 12Z THURSDAY. ALTHOUGH...CONFIDENCE IN EXACT
TIMING IS NOT GREAT. ALSO...THE RAPID REFRESH REFLECTIVITY PROGS
INITIATE MOST OF THE CONVECTION SOUTH OF LAF...SO WILL ONLY GO WITH
VCTS AT LAF AND 3 HOUR TEMPO GROUPS ELSEWHERE. WILL ALSO ADD TEMPO
THUNDERSTORM WIND GUSTS TO 40 KNOTS...AND HIGHER GUSTS ARE ALSO
POSSIBLE.
FLYING CONDITIONS OUTSIDE OF STORMS SHOULD BE MOSTLY VFR THIS
MORNING BUT...COULD SEE SOME MVFR MAINLY BEFORE 15Z. WITHIN
THUNDERSTORMS...CONDITIONS SHOULD BE MVFR AND POSSIBLY WORSE.
WINDS WILL BE SOUTHWEST AHEAD OF THE FRONT AND SWITCH TO WEST
AS IT GETS CLOSER AND THEN NORTHWEST AND NORTH BEHIND THE FRONT.
WINDS SHOULD BE 15 KNOTS OR LESS TODAY AND LESS THAN 10 KNOTS AFTER
00Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...TDUD/50
SHORT TERM...TDUD
LONG TERM....MK
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
132 AM EDT WED MAY 21 2014
.SYNOPSIS...
ISSUED AT 343 PM EDT TUE MAY 20 2014
A COLD FRONT WILL SLOWLY SLIP SOUTH INTO THE REGION OVER THE NEXT
24 HOURS. SHOWERS AND THUNDERSTORMS ARE EXPECTED
TONIGHT...ESPECIALLY ACROSS PORTIONS OF LOWER MICHIGAN...NORTHERN
INDIANA AND NORTHWESTERN OHIO WITH SEVERE WEATHER A POSSIBILITY.
THE COLD FRONT WILL MOVE THROUGH ON WEDNESDAY WITH ADDITIONAL
CHANCES OF SHOWERS AND THUNDERSTORMS. LOWS TONIGHT WILL DROP INTO
THE 60S WITH HIGHS WEDNESDAY GENERALLY IN THE LOWER 80S...WITH
LOCALLY COOLER CONDITIONS ALONG THE LAKE.
&&
.UPDATE...
ISSUED AT 750 PM EDT TUE MAY 20 2014
CONVECTION HAS RAPIDLY DEVELOPED THIS EVENING ACROSS IN VICINITY
OF LOW LEVEL TROUGH AXIS FROM EASTERN IOWA INTO FAR SOUTHERN
WISCONSIN. A SECONDARY AREA OF WEAK PREFRONTAL CONVERGENCE HAS
ALSO LED TO A SECONDARY BROKEN LINE OF THUNDERSTORMS ACROSS
NORTHERN ILLINOIS. MODERATE INSTABILITY DEPICTED PER 23Z RAP
ANALYSIS FROM NORTHERN ILLINOIS INTO FAR NORTHERN INDIANA/SOUTHERN
LOWER MICHIGAN WITH 100 HPA MLCAPES ON THE ORDER OF 1500-2000
J/KG. AS OF 23Z...STRONGEST DEEP LAYER SHEAR RESIDES NORTH AND
WEST OF LOCAL AREA...BUT POCKET OF STRONGER UPPER LEVEL WESTERLIES
SHOULD OVERSPREAD SOUTHERN GREAT LAKES REGION OVER THE NEXT FEW
HOURS...INCREASING EFFECTIVE SHEAR ACROSS AT LEAST NORTHERN HALF
OF THE AREA. PER SPC MESODISCUSSIONS AND CONVECTIVE
OUTLOOKS...UPSCALE GROWTH STILL OF SOMEWHAT LOW CONFIDENCE GIVEN
LACK OF STRONG MID/UPPER LEVEL FORCING. HOWEVER...COMBINATION OF
MODERATE INSTABILITY AND INCREASING DEEP LAYER EFFECTIVE SHEAR
SHOULD AT LEAST SUPPORT ISOLD SEVERE RISK INTO NORTHWEST PORTIONS
OF THE AREA LATER THIS EVENING CONSIDERING ADDITIONAL OUTFLOW
INTERACTIONS WITH UPSTREAM CONVECTION. HAVE NOT MADE MANY CHANGES
TO PREVIOUS FORECAST WITH ONLY TWEAK TO SHAVE OFF POPS SOME ACROSS
SOUTHEAST HALF OF THE AREA OVER NEXT FEW HOURS. DID NOT MAKE
SUBSTANTIAL CHANGES TO POPS AFTER 03Z WITH SOME CONCERN THAT IF
UPSTREAM CONVECTION CAN CONGEAL...EASTWARD PROPAGATION WILL
ACCELERATE LATER THIS EVENING ACROSS EAST/SOUTHEAST PORTIONS OF
THE FORECAST AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 333 PM EDT TUE MAY 20 2014
...THREAT OF SEVERE WEATHER THIS EVENING...POSSIBLY INTO OVERNIGHT
HOURS...
MAIN FOCUS RESIDES ON COLD FRONT EXTENDING FROM CNTRL LK MI INTO
IOWA WHICH WILL BECOME THE TRIGGER POINT FOR THUNDERSTORMS OVER THE
NEXT COUPLE OF HOURS. CONCERNS LOOM IN EXACTLY HOW THESE STORMS WILL
EVOLVE AND DROP SE TOWARDS THE FORECAST AREA TONIGHT. SPC
MESOANALYSIS SHOWS SFC BASED CAPES 2000 TO 3000 J/KG WERE POOLING
ALONG THE FRONT WITH STEEPENING LAPSE RATES AND INCREASING SHEAR. CU
FIELD HAVE BEEN RATHER SUBDUED THUS FAR ALONG THE FRONT. HOWEVER ALL
HIGH RES MODELS SEEM TO POINT TOWARDS RAPID FORMATION OF STORMS IN
THE 21 TO 23Z TIME FRAME. INITIAL STORM MODE SHOULD BE MULTICELL
CLUSTERS/SOME SUPERCELLS WHICH WILL PRODUCE HAIL AND DAMAGING
WINDS...ALONG WITH SOME TORNADO THREAT. COLD POOL SHOULD BEGIN TO
ESTABLISH WITH CORFIDI VECTORS INDICATED A RAPID FORWARD PROPAGATION
INTO NW PARTS OF THE AREA AFTER 00Z AND OVERSPREADING AT LEAST
NORTHERN HALF THE REMAINDER OF THE EVENING. TIMING OF DAY WILL PLAY
SOMEWHAT AGAINST SEVERE POTENTIAL AS WILL FACT THAT ACTUAL COLD
FRONT WILL RESIDE WELL NW OF THE AREA UNTIL LATER TONIGHT.
HOWEVER...ALL SIGNS CONTINUE TO POINT TOWARDS INCREASING SEVERE
THREAT THIS EVENING...WARRANTING INCREASE IN POPS AND ADDITION OF
SVR WORDING. SOUTHERN EXTENT VERY QUESTIONABLE AS OUTFLOW BOUNDARIES
EVENTUALLY RACE AHEAD OF THE LINE AND ALLOW FOR POTENTIAL FOR THE
LINE TO STALL OUT WITH HRRR INDICATING SOME POTENTIAL FOR ADDITIONAL
DEVELOPMENT ACROSS ILLINOIS/IOWA MOVING IN LATER THIS EVENING. HAVE
NOT ADDED MENTION OF HVY RAIN...BUT TRAINING OF CELLS WILL BE
POSSIBLE WITH INHERENT THREAT FOR FLOODING. WILL DEFER TO EVE SHIFT
TO MONITOR TRENDS.
NO CHANGES TO FORECAST ON WEDNESDAY WITH RESIDUAL BOUNDARY FROM
OVERNIGHT CONVECTION BEING KEY IN CONVECTIVE CHANCES AS ACTUAL COLD
FRONT MOVES IN. NEW DAY2 OUTLOOK HAS SHOVED SLGT RISK A BIT FURTHER
SOUTH ACROSS MAINLY SE THIRD OF THE AREA WHICH IS REASONABLE AT THIS
STAGE. WILL DEFER TO OVERNIGHT SHIFT TO MAKE ADJUSTMENTS.
&&
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 333 PM EDT TUE MAY 20 2014
CDFNT SHOULD BE MOVG THROUGH S-SE PORTION OF CWA AT START OF THE
PERIOD WED EVE. CONVECTION WILL PRBLY HAVE MOVED OUT AHEAD OF THE
FRONT BY 00Z AND BE LOCATED S-SE OF THE CWA, BUT THERE IS A SMALL
CHC OF ACTIVITY CONTG TO DEVELOP ALONG IT, SO MAINTAINED A LOW POP
THROUGH WED EVE. COOLER/DRIER AIRMASS WILL SPREAD INTO THE AREA
BEHIND THE CDFNT BY THURSDAY. SHRTWV MOVG THROUGH THE UPR GRTLKS
TONIGHT/WED EXPECTED TO TRANSITION TO A CUT-OFF LOW OVER NERN
U.S./SE CANADA BY THU WITH ANOTHER CUT-OFF LOW LINGERING OVER THE
SWRN CONUS WHILE IN BETWEEN RIDGE OVER CENTRAL U.S. WILL PROVIDE
OUR AREA WITH FAIR WX LATE THIS WEEK. THESE SYSTEMS EXPECTED TO
MAKE SLOW E-NE PROGRESS OVER THE WEEKEND AND EARLY NEXT WEEK,
LIKELY CONTG THE DRY SPELL ACROSS OUR CWA. TEMPS THU SHOULD BE A
BIT BLO NORMAL, MODIFYING TO WELL ABOVE NORMAL OVER THE HOLIDAY
WEEKEND AS THE UPR RIDGE BUILDS INTO THE AREA. RETURN FLOW WILL
RESULT IN INCREASING LOW LEVEL MOISTURE AND SOME DEVELOPING
INSTABILITY AS SFC HIGH MOVES EAST OF THE AREA BY MONDAY, BUT
PROXIMITY OF UPR LEVEL RIDGE SUGGESTS ANY CONVECTION IN OUR AREA
WILL BE ISOLATED AT BEST, SO FOR NOW HELD OFF ADDING TO FCST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 127 AM EDT WED MAY 21 2014
RADAR AND SATELLITE TRENDS DICTATING NEAR TERM TAF PERIOD.
CONVECTIVE LINES ABOUT TO MOVE THROUGH BOTH KSBN AND KFWA. WIND
GUSTS TO 35 KNOTS POSSIBLE WITH MVFR CONDITIONS. BRIEF IFR
POSSIBLE...MAINLY FROM REDUCED VIS IN HEAVY RAINFALL. KFWA TO SEE
END TO PCPN BY 07Z BUT RADAR SHOWS SEVERAL CLUSTERS WEST OF KSBN
THAT MAY CONTINUE TO IMPACT THAT SITE THROUGH 09Z OR 10Z. MVFR
CIGS AND VIS DEVELOPMENT IN COOL AND MOIST BOUNDARY LAYER STILL
POSSIBLE TOWARD DAYBREAK. COLD FRONT SAGS SOUTH THIS AFTERNOON
WITH SOME LOW END CONVECTIVE POTENTIAL CLOSER TO KFWA SO INCLUDED
A PROB30 THERE TO ACCOUNT FOR ANY DEVELOPMENT. OTHERWISE VFR.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...MARSILI
SYNOPSIS...MURPHY/FISHER
SHORT TERM...FISHER
LONG TERM...JT
AVIATION...LASHLEY
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1250 AM EDT WED MAY 21 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 344 PM EDT TUE MAY 20 2014
A FRONTAL SYSTEM WILL BRING CHANCES FOR THUNDERSTORMS TO CENTRAL
INDIANA STARTING LATE TONIGHT ACROSS THE NORTH AND SPREADING SOUTH
WEDNESDAY AS A COLD FRONT SINKS SOUTH THROUGH THE AREA. THE BEST
CHANCES FOR SEVERE STORMS WITH THIS SYSTEM WILL BE WEDNESDAY
AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT
THURSDAY USHERING IN DRY WEATHER WITH IT FOR THE REMAINDER OF THE
PERIOD.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 940 PM EDT TUE MAY 20 2014
SCATTERED CONVECTION HAS BEEN OCCURRING ACROSS NORTHERN ILLINOIS
BACK INTO IOWA OVER THE PAST FEW HOURS. THIS EVENING/S UPPER AIR
INDICATES RATHER WEAK DEEP LAYER SHEAR ACROSS THE AREA...ALTHOUGH
MID LEVEL LAPSE RATES ARE VERY STEEP. SO FAR...HAVEN/T SEEN ANY
INDICATION OF A CONSOLIDATING COLD POOL FROM THE CONVECTION OFF TO
THE NORTH...ALTHOUGH SHORT TERM MODEL DATA SUGGEST A POTENTIAL
OUTFLOW MOVING INTO THE NORTHERN ZONES AFTER MIDNIGHT. STILL UNCLEAR
AS TO WHETHER CONVECTION WILL BUILD SOUTH INTO THE AREA LATER
TONIGHT. 850MB FLOW INTO THE CONVECTIVE AREA IS DECENT...BUT NOT
PARTICULARLY STRONG.
WILL KEEP CHANCE POPS GOING OVER THE NORTHERN HALF OF THE AREA
TONIGHT...BUT WILL BACK OFF ON THE TIMING UNTIL AFTER MIDNIGHT.
PREVIOUS DISCUSSION FOLLOWS.
SOME UNCERTAINTY STILL EXISTS WITH TONIGHT/S FORECAST CONCERNING HOW
FAR SOUTH STORMS WILL GET. SHORT TERM MODEL GUIDANCE WAS TRENDING
DRIER AND PUSHING THE POPS NORTH FOR SEVERAL RUNS THIS MORNING...BUT
LATEST RUNS OF RAP HAVE STARTED BRINGING ECHOES FURTHER SOUTH AND
VERY CLOSE TO THE NORTHERN COUNTIES. THE INFLUENCE OF THE UPPER
RIDGE SHOULD KEEP INITIAL FORMATION WELL NORTH OF THE FORECAST AREA
AND EXPECT CONDITIONS TO REMAIN DRY FOR A TIME AFTER 0Z. BY 6Z
HOWEVER COULD SEE STORMS STARTING TO APPROACH THE NORTHERN
COUNTIES...AND WOULD NOT BE OUT OF THE REALM OF POSSIBILITIES TO SEE
AN MCS DEVELOP AND RIDGE THE THETA E GRADIENT AROUND THE EDGE OF THE
UPPER RIDGE WHICH COULD BRING IT INTO THE NORTHERN/NORTHEASTERN
COUNTIES. NAM SEEMS TO FAVOR DEVELOPMENT A DECENT BIT FURTHER SOUTH
THAN OTHER SOLUTIONS AND GENERALLY DISCOUNTED IT. CONSIDERING THE
UNCERTAINTY AND VARIETY OF SOLUTIONS RIGHT NOW...THINK BEST COURSE
OF ACTION IS TO INCLUDE MID CHANCE POPS ALONG THE NORTHERN TO
NORTHEASTERN BORDER AND BRING A SLIGHT CHANCE DOWN ALONG THE EASTERN
BORDER AROUND 9Z THAT RUNS THROUGH 12Z TO ACCOUNT FOR THE LOW CHANCE
OF A RIGHT TURNING MCS
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 344 PM EDT TUE MAY 20 2014
FORECAST FOCUS IS ON CHANCES FOR SEVERE STORMS WEDNESDAY. CIN DROPS
OFF DURING THE DAY ON WEDNESDAY WHILE MLCAPES CLIMB TO OVER 2000
OVER MUCH OF THE FORECAST AREA BY THE AFTERNOON. THE COLD FRONT
SHOULD GET INTO THE NORTHWESTERN COUNTIES AROUND 12-15Z AND START
SINKING SOUTH THROUGH THE AREA...BUT MOVES THROUGH VERY SLOWLY.
0-6 KM BULK SHEAR INCREASES DURING THE AFTERNOON AND...ALONG WITH
THE AFOREMENTIONED INSTABILITY AND FRONTAL FORCING...SHOULD BE
SUFFICIENT TO SUPPORT AN ORGANIZED SEVERE THREAT THAT WILL BE
MAXIMIZED DURING THE 18Z WED-3Z THU TIMEFRAME.
WITH THIS SET OF MODEL RUNS THE FRONT DOES NOT MOVE AS QUICKLY AWAY
FROM THE AREA AND THUS HELD POPS INTO EARLY THURSDAY MORNING
/STILL PRIOR TO 12Z/ IN THE SOUTH. LOOKS LIKE HIGH PRESSURE WILL
BE BUILDING IN ENOUGH TO DRY OUT ALL PRECIP BY 12Z THOUGH AND THEN
WILL KEEP THE WEATHER DRY THROUGH THE SHORT TERM.
FOR TEMPERATURES GUIDANCE WAS CLOSE AND GENERALLY USED A CONSENSUS
EXCEPT FOR WEDNESDAY WHEN FAVORED WARMER MAV NUMBERS BASED ON
CONTINUED STRONG WARM ADVECTION AHEAD OF THE COLD FRONT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 237 PM EDT TUE MAY 20 2014
HOLIDAY WEEKEND LOOKS FANTASTIC WITH WARM DRY WEATHER EXPECTED AS
SURFACE HIGH PRESSURE DRIFTS SLOWLY THROUGH THE OHIO VALLEY.
NORTHERLY FLOW AND WEAK COLD ADVECTION INITIALLY EXPECTED BUT AS
THE CENTER OF THE HIGH SHIFTS EAST OF THE REGION...RETURN FLOW AND
THE ARRIVAL OF AN UPPER RIDGE WILL ENABLE STEADILY WARMING TEMPS
WITH THE POTENTIAL FOR SOME OF THE WARMEST AIR OF THE YEAR SO FAR
TO ARRIVE MONDAY AND TUESDAY. HIGHS IN THE 70S SATURDAY WILL RISE
INTO THE MID 80S BY MONDAY AND TUESDAY WITH SOME HINTS THAT TEMPS
COULD FLIRT WITH THE UPPER 80S IN SOUTHERN COUNTIES.
INCREASING MOISTURE BY MONDAY AND TUESDAY COULD SUPPORT AN
ISOLATED CONVECTIVE THREAT BUT IN THE ABSENCE OF ANY SIGNIFICANT
FORCING UNDER THE RIDGE...BELIEVE CHANCES ARE TOO LOW TO MENTION
AT THIS TIME.
&&
.AVIATION /DISCUSSION FOR THE 210600Z TAF ISSUANCE/...
ISSUED AT 1250 AM EDT WED MAY 21 2014
VFR CONDITIONS FOR MOST OF THIS PERIOD...WITH THE POTENTIAL FOR SOME
LOWER FLIGHT CATEGORIES (MFVR) ACROSS THE NRN SITES SUCH AS
KLAF...CLOSER TO CONVECTIVE POTENTIAL EARLY THIS MORNING. BASED ON
LATEST RADAR MOSAIC TRENDS AND SHORT TERM GUIDANCE...HAVE BACKED OFF
ON MENTIONING ANY VCTS AND CB...SAVE FOR KLAF. KIND KHUF AND KBMG
LIKELY TOO FAR SOUTH TO LIMIT ANY IMPACTS FROM A WEAKENING
THUNDERSTORM CLUSTER. MVFR AND LOWER RESTRICTIONS WILL BE POSSIBLE
WITHIN THE STORMS.
MODEL SOUNDINGS SUPPORT SOME CLEARING BY MIDDAY WITH WINDS VEERING
TO A MORE WESTERLY DIRECTION AS THE COLD FRONT SETTLES ACROSS
CENTRAL INDIANA. RENEWED CONVECTIVE DEVELOPMENT THIS AFTERNOON
EXPECTED AFTER 18Z FOCUSED ALONG AND SOUTH OF I-70. CONFIDENCE IS
LOW THIS FAR OUT IN THE FORECAST TO INCLUDE ANY MENTION OF TS AT
THIS TIME. ONLY INDICATED A LOW STRATUS DECK AROUND 4K FT AND
SCATTERED SHOWERS FOR THE TIME BEING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP/JAS
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...SMF
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1247 PM CDT WED MAY 21 2014
.SYNOPSIS...
ISSUED AT 330 AM CDT WED MAY 21 2014
06Z SFC ANALYSIS HAS A FRONT FROM NORTHEAST ILLINOIS INTO
NORTHEAST KANSAS. SEVERAL LOWS WERE ALONG THE FRONT FROM NORTHEAST
KANSAS INTO SOUTHEAST IOWA. A STRONGER COLD FRONT RAN FROM WESTERN
LAKE SUPERIOR INTO NORTHERN KANSAS. DEW POINTS WERE IN THE 60S
FROM THE DEEP SOUTH INTO THE WESTERN GREAT LAKES WITH 40S AND 50S
FROM THE NORTHERN PLAINS INTO THE UPPER MIDWEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT WED MAY 21 2014
WEAK LOW PRESSURE MOVING ALONG THE FRONT HELPED INITIATE NEW
STORMS ACROSS THE CENTRAL PARTS OF THE AREA. ALTHOUGH NOT SLOW
MOVING...THESE STORMS PRODUCED COPIOUS AMOUNTS OF RAINFALL IN A
VERY SHORT TIME PERIOD.
TRENDS FROM THE RAP INDICATE THE CURRENT STORMS ACROSS THE AREA
WILL CONTINUE TO MOVE EAST IN A NARROW BAND AND SLOWLY DISSIPATE
THROUGH SUNRISE AS THE OVERALL FORCING WEAKENS.
MUCH OF THE MORNING AND AFTERNOON HOURS ARE EXPECTED TO REMAIN DRY
UNTIL ANOTHER ROUND OF FORCING ARRIVES DURING PEAK HEATING. NEW
STORMS SHOULD THEN DEVELOP ACROSS THE FAR SOUTH CLOSE TO THE
FRONTAL BOUNDARY.
TONIGHT...THE AFTERNOON STORMS THAT DEVELOP WILL CONTINUE ACROSS
THE FAR SOUTH DURING THE EVENING BEFORE DISSIPATING. BOUNDARIES
FROM THIS CONVECTION ALONG WITH THE COLD FRONT WILL ALLOW A NEW
NOCTURNAL THUNDERSTORM COMPLEX TO DEVELOP IN NORTHWEST MISSOURI
AND THEN MOVE GENERALLY EAST SOUTHEAST THROUGH SUNRISE THURSDAY.
THE AREA THAT HAS THE BEST CHANCES FOR RAIN WILL BE THE FAR SOUTH
AND THE RAINFALL MAY BE LOCALLY HEAVY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED MAY 21 2014
THURSDAY THROUGH FRIDAY NIGHT THE COLD FRONT WILL REMAIN ACROSS
NORTHERN MISSOURI. INTERNALLY...THE MODELS ARE INDICATING THE THE
ACTIVE ZONE FOR NOCTURNAL THUNDERSTORM COMPLEXES WILL BE CLOSE TO
THE AREA.
THE OVERALL MOISTURE AND FORCING BEING SUGGESTED BY THE MODELS
INDICATES THAT A NOCTURNAL THUNDERSTORM COMPLEX MAY BRUSH THE FAR
SOUTHWEST/SOUTH THURSDAY/THURSDAY NIGHT BUT THEN PUSH THE FRONT
FURTHER TO THE SOUTH/WEST FOR FRIDAY AND FRIDAY NIGHT.
TEMPERATURES WILL BE CLOSE TO NORMAL.
SATURDAY ON...
THE MODEL CONSENSUS HAS MAINLY DRY CONDITIONS ON SATURDAY AS THE
BETTER MOISTURE AND FORCING REMAIN WEST OF THE AREA. TEMPERATURES
WILL BE CLOSE TO NORMAL.
STARTING SATURDAY NIGHT AND CONTINUING THROUGH TUESDAY THE MODEL
CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS EACH DAY. WILL IT RAIN
CONTINUOUSLY THE ENTIRE TIME. NO. HOWEVER...THE BIG PICTURE
INDICATES THE WEATHER PATTERN WILL BE TURNING MORE ACTIVE WITH
SOUTHWEST FLOW ALOFT DEVELOPING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1239 PM CDT WED MAY 21 2014
A LOW CHANCE FOR AN ISOLATED THUNDERSTORM TO DEVELOP IN VCNTY OR
JUST TO THE SOUTH OF THE BRL TAF SITE LATER THIS AFTERNOON AND
EVENING. TO THE NORTH...ANOTHER LOW CHANCE FOR A BKN MVFR DECK TO
MOVE OUT OF MN AND CLIP THE DBQ TAF SITE FROM 03Z-09Z THU/TONIGHT.
OTHERWISE A VFR TAF CYCLE THROUGH 18Z THU. SFC WINDS TO CONTINUE
TO BECOME MORE NORTHERLY AS THE DAY/EVENING PROGRESSES BEHIND A
COOL FRONT SAGGING TO THE SOUTH ACRS NORTHERN MO AND INTO CENTRAL
IL. NORTHERLY LLVL FLOW AND DRYING SFC DPT ADVECTION SHOULD
PRECLUDE ANY FOG DEVELOPMENT OVERNIGHT INTO EARLY THU MORNING IN
VCNTY OF THE TAF SITES. ..12..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...08
AVIATION...12
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
654 AM CDT WED MAY 21 2014
.UPDATE...
ISSUED AT 442 AM CDT WED MAY 21 2014
CONVECTION ALONG THE FRONT IS DISSIPATING MUCH FASTER THAN
PREVIOUSLY THOUGHT AS THE FORCING ALOFT WEAKENS. THE MOST RECENT
RAP TRENDS INDICATE DOWNWARD MOTION GETTING STRONGER ACROSS
EASTERN IOWA OVER THE NEXT SEVERAL HOURS.
THE FORECAST THROUGH SUNRISE AND THE MORNING COMMUTE HAS BEEN
UPDATED TO REFLECT THESE TRENDS.
&&
.SYNOPSIS...
ISSUED AT 330 AM CDT WED MAY 21 2014
06Z SFC ANALYSIS HAS A FRONT FROM NORTHEAST ILLINOIS INTO
NORTHEAST KANSAS. SEVERAL LOWS WERE ALONG THE FRONT FROM NORTHEAST
KANSAS INTO SOUTHEAST IOWA. A STRONGER COLD FRONT RAN FROM WESTERN
LAKE SUPERIOR INTO NORTHERN KANSAS. DEW POINTS WERE IN THE 60S
FROM THE DEEP SOUTH INTO THE WESTERN GREAT LAKES WITH 40S AND 50S
FROM THE NORTHERN PLAINS INTO THE UPPER MIDWEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT WED MAY 21 2014
WEAK LOW PRESSURE MOVING ALONG THE FRONT HELPED INITIATE NEW
STORMS ACROSS THE CENTRAL PARTS OF THE AREA. ALTHOUGH NOT SLOW
MOVING...THESE STORMS PRODUCED COPIOUS AMOUNTS OF RAINFALL IN A
VERY SHORT TIME PERIOD.
TRENDS FROM THE RAP INDICATE THE CURRENT STORMS ACROSS THE AREA
WILL CONTINUE TO MOVE EAST IN A NARROW BAND AND SLOWLY DISSIPATE
THROUGH SUNRISE AS THE OVERALL FORCING WEAKENS.
MUCH OF THE MORNING AND AFTERNOON HOURS ARE EXPECTED TO REMAIN DRY
UNTIL ANOTHER ROUND OF FORCING ARRIVES DURING PEAK HEATING. NEW
STORMS SHOULD THEN DEVELOP ACROSS THE FAR SOUTH CLOSE TO THE
FRONTAL BOUNDARY.
TONIGHT...THE AFTERNOON STORMS THAT DEVELOP WILL CONTINUE ACROSS
THE FAR SOUTH DURING THE EVENING BEFORE DISSIPATING. BOUNDARIES
FROM THIS CONVECTION ALONG WITH THE COLD FRONT WILL ALLOW A NEW
NOCTURNAL THUNDERSTORM COMPLEX TO DEVELOP IN NORTHWEST MISSOURI
AND THEN MOVE GENERALLY EAST SOUTHEAST THROUGH SUNRISE THURSDAY.
THE AREA THAT HAS THE BEST CHANCES FOR RAIN WILL BE THE FAR SOUTH
AND THE RAINFALL MAY BE LOCALLY HEAVY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED MAY 21 2014
THURSDAY THROUGH FRIDAY NIGHT THE COLD FRONT WILL REMAIN ACROSS
NORTHERN MISSOURI. INTERNALLY...THE MODELS ARE INDICATING THE THE
ACTIVE ZONE FOR NOCTURNAL THUNDERSTORM COMPLEXES WILL BE CLOSE TO
THE AREA.
THE OVERALL MOISTURE AND FORCING BEING SUGGESTED BY THE MODELS
INDICATES THAT A NOCTURNAL THUNDERSTORM COMPLEX MAY BRUSH THE FAR
SOUTHWEST/SOUTH THURSDAY/THURSDAY NIGHT BUT THEN PUSH THE FRONT
FURTHER TO THE SOUTH/WEST FOR FRIDAY AND FRIDAY NIGHT.
TEMPERATURES WILL BE CLOSE TO NORMAL.
SATURDAY ON...
THE MODEL CONSENSUS HAS MAINLY DRY CONDITIONS ON SATURDAY AS THE
BETTER MOISTURE AND FORCING REMAIN WEST OF THE AREA. TEMPERATURES
WILL BE CLOSE TO NORMAL.
STARTING SATURDAY NIGHT AND CONTINUING THROUGH TUESDAY THE MODEL
CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS EACH DAY. WILL IT RAIN
CONTINUOUSLY THE ENTIRE TIME. NO. HOWEVER...THE BIG PICTURE
INDICATES THE WEATHER PATTERN WILL BE TURNING MORE ACTIVE WITH
SOUTHWEST FLOW ALOFT DEVELOPING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 643 AM CDT WED MAY 21 2014
GENERALLY VFR CONDITIONS EXPECTED THROUGH THE TAF CYCLE. PATCHY
SHALLOW FOG NORTH OF I-80 WITH VARIABLE VSBYS FROM LIFR TO MVFR
WILL DISSIPATE NEXT 1-2 HOURS WITH INCREASING NORTH WINDS. COLD
FRONT TO SAG SOUTH OF KMLI AND KBRL BY MIDDAY WITH ANY SHOWERS
AND STORMS THIS AFTERNOON STAYING SOUTH OF KBRL. NORTHERLY
WINDS WILL INCREASE AT TERMINALS TO AROUND 10-15 KTS BY MIDDAY
WITH SOME LOCAL GUSTS TO NEAR 20 KTS POSSIBLE AT TIMES OVER
NORTHEAST IA. NORTHERLY WINDS THEN DECREASE BELOW 10 KTS TONIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...08
AVIATION...05
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
446 AM CDT WED MAY 21 2014
.UPDATE...
ISSUED AT 442 AM CDT WED MAY 21 2014
CONVECTION ALONG THE FRONT IS DISSIPATING MUCH FASTER THAN
PREVIOUSLY THOUGHT AS THE FORCING ALOFT WEAKENS. THE MOST RECENT
RAP TRENDS INDICATE DOWNWARD MOTION GETTING STRONGER ACROSS
EASTERN IOWA OVER THE NEXT SEVERAL HOURS.
THE FORECAST THROUGH SUNRISE AND THE MORNING COMMUTE HAS BEEN
UPDATED TO REFLECT THESE TRENDS.
&&
.SYNOPSIS...
ISSUED AT 330 AM CDT WED MAY 21 2014
06Z SFC ANALYSIS HAS A FRONT FROM NORTHEAST ILLINOIS INTO
NORTHEAST KANSAS. SEVERAL LOWS WERE ALONG THE FRONT FROM NORTHEAST
KANSAS INTO SOUTHEAST IOWA. A STRONGER COLD FRONT RAN FROM WESTERN
LAKE SUPERIOR INTO NORTHERN KANSAS. DEW POINTS WERE IN THE 60S
FROM THE DEEP SOUTH INTO THE WESTERN GREAT LAKES WITH 40S AND 50S
FROM THE NORTHERN PLAINS INTO THE UPPER MIDWEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT WED MAY 21 2014
WEAK LOW PRESSURE MOVING ALONG THE FRONT HELPED INITIATE NEW
STORMS ACROSS THE CENTRAL PARTS OF THE AREA. ALTHOUGH NOT SLOW
MOVING...THESE STORMS PRODUCED COPIOUS AMOUNTS OF RAINFALL IN A
VERY SHORT TIME PERIOD.
TRENDS FROM THE RAP INDICATE THE CURRENT STORMS ACROSS THE AREA
WILL CONTINUE TO MOVE EAST IN A NARROW BAND AND SLOWLY DISSIPATE
THROUGH SUNRISE AS THE OVERALL FORCING WEAKENS.
MUCH OF THE MORNING AND AFTERNOON HOURS ARE EXPECTED TO REMAIN DRY
UNTIL ANOTHER ROUND OF FORCING ARRIVES DURING PEAK HEATING. NEW
STORMS SHOULD THEN DEVELOP ACROSS THE FAR SOUTH CLOSE TO THE
FRONTAL BOUNDARY.
TONIGHT...THE AFTERNOON STORMS THAT DEVELOP WILL CONTINUE ACROSS
THE FAR SOUTH DURING THE EVENING BEFORE DISSIPATING. BOUNDARIES
FROM THIS CONVECTION ALONG WITH THE COLD FRONT WILL ALLOW A NEW
NOCTURNAL THUNDERSTORM COMPLEX TO DEVELOP IN NORTHWEST MISSOURI
AND THEN MOVE GENERALLY EAST SOUTHEAST THROUGH SUNRISE THURSDAY.
THE AREA THAT HAS THE BEST CHANCES FOR RAIN WILL BE THE FAR SOUTH
AND THE RAINFALL MAY BE LOCALLY HEAVY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED MAY 21 2014
THURSDAY THROUGH FRIDAY NIGHT THE COLD FRONT WILL REMAIN ACROSS
NORTHERN MISSOURI. INTERNALLY...THE MODELS ARE INDICATING THE THE
ACTIVE ZONE FOR NOCTURNAL THUNDERSTORM COMPLEXES WILL BE CLOSE TO
THE AREA.
THE OVERALL MOISTURE AND FORCING BEING SUGGESTED BY THE MODELS
INDICATES THAT A NOCTURNAL THUNDERSTORM COMPLEX MAY BRUSH THE FAR
SOUTHWEST/SOUTH THURSDAY/THURSDAY NIGHT BUT THEN PUSH THE FRONT
FURTHER TO THE SOUTH/WEST FOR FRIDAY AND FRIDAY NIGHT.
TEMPERATURES WILL BE CLOSE TO NORMAL.
SATURDAY ON...
THE MODEL CONSENSUS HAS MAINLY DRY CONDITIONS ON SATURDAY AS THE
BETTER MOISTURE AND FORCING REMAIN WEST OF THE AREA. TEMPERATURES
WILL BE CLOSE TO NORMAL.
STARTING SATURDAY NIGHT AND CONTINUING THROUGH TUESDAY THE MODEL
CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS EACH DAY. WILL IT RAIN
CONTINUOUSLY THE ENTIRE TIME. NO. HOWEVER...THE BIG PICTURE
INDICATES THE WEATHER PATTERN WILL BE TURNING MORE ACTIVE WITH
SOUTHWEST FLOW ALOFT DEVELOPING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1131 PM CDT TUE MAY 20 2014
THE OVERALL TREND FOR SHOWERS AND STORM THE REST OF TONIGHT SHOULD
BE DIMINISHING IN BOTH COVERAGE AND INTENSITY. THE THREAT OF
STORMS AT DBQ SHOULD BE VERY LOW WITH THE SURFACE BOUNDARY ALREADY
TO THE SOUTH. HAVE MAINTAINED A TEMPO GROUP FOR TSRA AT KCID WITH
SHRA/TSRA OVER AND JUST WEST OF THE AIRPORT. THIS ACTIVITY ALSO
SUPPORTED KEEPING A VCTS GOING A MLI FOR A FEW HOURS. THE THREAT
OF SHRA/TSRA AT KBRL SHOULD BE LOW SO DID NOT MENTION ANY
SHRA/TSRA THERE. WITH LIGHT WINDS OVER THE AREA THE REST OF
TONIGHT AND THE POTENTIAL FOR SOME CLEAR...HAVE CONTINUED THE
MENTION OF MVFR VSBYS IN FOG OVERNIGHT. FOR THE WEDNESDAY...FLIGHT
CONDITIONS SHOULD BE VFR THROUGH 06Z.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...08
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
349 AM CDT WED MAY 21 2014
.SYNOPSIS...
ISSUED AT 330 AM CDT WED MAY 21 2014
06Z SFC ANALYSIS HAS A FRONT FROM NORTHEAST ILLINOIS INTO
NORTHEAST KANSAS. SEVERAL LOWS WERE ALONG THE FRONT FROM NORTHEAST
KANSAS INTO SOUTHEAST IOWA. A STRONGER COLD FRONT RAN FROM WESTERN
LAKE SUPERIOR INTO NORTHERN KANSAS. DEW POINTS WERE IN THE 60S
FROM THE DEEP SOUTH INTO THE WESTERN GREAT LAKES WITH 40S AND 50S
FROM THE NORTHERN PLAINS INTO THE UPPER MIDWEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT WED MAY 21 2014
WEAK LOW PRESSURE MOVING ALONG THE FRONT HELPED INITIATE NEW
STORMS ACROSS THE CENTRAL PARTS OF THE AREA. ALTHOUGH NOT SLOW
MOVING...THESE STORMS PRODUCED COPIOUS AMOUNTS OF RAINFALL IN A
VERY SHORT TIME PERIOD.
TRENDS FROM THE RAP INDICATE THE CURRENT STORMS ACROSS THE AREA
WILL CONTINUE TO MOVE EAST IN A NARROW BAND AND SLOWLY DISSIPATE
THROUGH SUNRISE AS THE OVERALL FORCING WEAKENS.
MUCH OF THE MORNING AND AFTERNOON HOURS ARE EXPECTED TO REMAIN DRY
UNTIL ANOTHER ROUND OF FORCING ARRIVES DURING PEAK HEATING. NEW
STORMS SHOULD THEN DEVELOP ACROSS THE FAR SOUTH CLOSE TO THE
FRONTAL BOUNDARY.
TONIGHT...THE AFTERNOON STORMS THAT DEVELOP WILL CONTINUE ACROSS
THE FAR SOUTH DURING THE EVENING BEFORE DISSIPATING. BOUNDARIES
FROM THIS CONVECTION ALONG WITH THE COLD FRONT WILL ALLOW A NEW
NOCTURNAL THUNDERSTORM COMPLEX TO DEVELOP IN NORTHWEST MISSOURI
AND THEN MOVE GENERALLY EAST SOUTHEAST THROUGH SUNRISE THURSDAY.
THE AREA THAT HAS THE BEST CHANCES FOR RAIN WILL BE THE FAR SOUTH
AND THE RAINFALL MAY BE LOCALLY HEAVY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED MAY 21 2014
THURSDAY THROUGH FRIDAY NIGHT THE COLD FRONT WILL REMAIN ACROSS
NORTHERN MISSOURI. INTERNALLY...THE MODELS ARE INDICATING THE THE
ACTIVE ZONE FOR NOCTURNAL THUNDERSTORM COMPLEXES WILL BE CLOSE TO
THE AREA.
THE OVERALL MOISTURE AND FORCING BEING SUGGESTED BY THE MODELS
INDICATES THAT A NOCTURNAL THUNDERSTORM COMPLEX MAY BRUSH THE FAR
SOUTHWEST/SOUTH THURSDAY/THURSDAY NIGHT BUT THEN PUSH THE FRONT
FURTHER TO THE SOUTH/WEST FOR FRIDAY AND FRIDAY NIGHT.
TEMPERATURES WILL BE CLOSE TO NORMAL.
SATURDAY ON...
THE MODEL CONSENSUS HAS MAINLY DRY CONDITIONS ON SATURDAY AS THE
BETTER MOISTURE AND FORCING REMAIN WEST OF THE AREA. TEMPERATURES
WILL BE CLOSE TO NORMAL.
STARTING SATURDAY NIGHT AND CONTINUING THROUGH TUESDAY THE MODEL
CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS EACH DAY. WILL IT RAIN
CONTINUOUSLY THE ENTIRE TIME. NO. HOWEVER...THE BIG PICTURE
INDICATES THE WEATHER PATTERN WILL BE TURNING MORE ACTIVE WITH
SOUTHWEST FLOW ALOFT DEVELOPING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1131 PM CDT TUE MAY 20 2014
THE OVERALL TREND FOR SHOWERS AND STORM THE REST OF TONIGHT SHOULD
BE DIMINISHING IN BOTH COVERAGE AND INTENSITY. THE THREAT OF
STORMS AT DBQ SHOULD BE VERY LOW WITH THE SURFACE BOUNDARY ALREADY
TO THE SOUTH. HAVE MAINTAINED A TEMPO GROUP FOR TSRA AT KCID WITH
SHRA/TSRA OVER AND JUST WEST OF THE AIRPORT. THIS ACTIVITY ALSO
SUPPORTED KEEPING A VCTS GOING A MLI FOR A FEW HOURS. THE THREAT
OF SHRA/TSRA AT KBRL SHOULD BE LOW SO DID NOT MENTION ANY
SHRA/TSRA THERE. WITH LIGHT WINDS OVER THE AREA THE REST OF
TONIGHT AND THE POTENTIAL FOR SOME CLEAR...HAVE CONTINUED THE
MENTION OF MVFR VSBYS IN FOG OVERNIGHT. FOR THE WEDNESDAY...FLIGHT
CONDITIONS SHOULD BE VFR THROUGH 06Z.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...08
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS DES MOINES IA
337 AM CDT WED MAY 21 2014
.SHORT TERM /TODAY/...
ISSUED AT 337 AM CDT WED MAY 21 2014
ISOLATED CENTRAL IA THUNDERSTORM APPROACHING SEVERE LIMITS
DISSIPATED QUICKLY LAST HOUR. RAP SOUNDINGS SEEMED TO REFLECT THE
ENVIRONMENT QUITE WELL WITH POTENTIAL FOR STORMS ROOTED NEAR THE
SURFACE SHORTLY AFTER MIDNIGHT...BUT MLCINH INCREASING QUICKLY AS
BOUNDARY LAYER COOLS FURTHER AND DECOUPLING FINALLY TAKING PLACE.
WITH THIS PROGRESSION DO NOT REALLY EXPECT ANY ADDITIONAL
DEVELOPMENT UNTIL PEAK HEATING OF THE AFTERNOON...WHICH IS THE
PRIMARY FORECAST CONCERN.
SCENARIO FOR TODAY HAS CHANGED LITTLE OVER THE PAST FEW DAYS WITH
SEVERE WEATHER POTENTIAL STILL CONDITIONAL. MODELS ALL DEPICT
SIMILAR THERMODYNAMIC ENVIRONMENT WITH MLCINH ERODING DURING THE
AFTERNOON AND MLCAPES TO AROUND 1500 J/KG. HOWEVER WHILE THE CINH
HAS DIMINISHED SUFFICIENTLY FOR CONVECTION TO FIRE...LIMITING
FACTORS INCLUDE WEAK CONVERGENCE AND THE FACT THAT WARM 1-3KM
TEMPS WILL KEEP PARCELS FROM REALLY ACCELERATING UNTIL REACHING
3KM OR HIGHER. THERE IS A QUESTION WHETHER THE WEAK CONVERGENCE
WILL OVERCOME THIS. LARGE SCALE FORCING MAY HELP LIFT AND
DESTABILIZATION OF 1-3KM LAYER TOWARD 00Z HOWEVER AS CURRENT
DAKOTAS MN JET SEGMENT MOVES EASTWARD. THUS STILL HAVE SCATTERED
THUNDERSTORMS DEVELOPING IN THE EASTERN HIGHWAY 30/I80/HIGHWAY 92
CORRIDORS. MAIN SEVERE THREATS STILL APPEAR TO BE LARGE HAIL OR
WIND. LOW LEVEL SHEAR FAIRLY WEAK WITH HIGHER LCLS. STORM MOTION
WILL BE FAIRLY SLOW TOO BASED ON MEAN WIND AND BUNKERS
MOTION...LIKELY UNDER 25KTS.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 337 AM CDT WED MAY 21 2014
FROM TONIGHT INTO FRIDAY NIGHT OUR WEATHER PATTERN WILL BE
DOMINATED BY NORTHWEST FLOW ALOFT AND A LARGE SURFACE HIGH
PRESSURE AREA DRAPED ACROSS THE UPPER MIDWEST...WITH GENERALLY
NORTHEAST WINDS ACROSS CENTRAL IOWA. THE FRONTAL BOUNDARY MOVING
ACROSS SOUTHERN IOWA THIS TUESDAY MORNING WILL REMAIN NEARLY
STATIONARY ACROSS NORTHERN MISSOURI LATER IN THE WEEK...PROVIDING
SHOWER AND THUNDERSTORM CHANCES ACROSS FAR SOUTHERN IOWA AT TIMES
BUT PRIMARILY RAIN WILL BE LIMITED TO SOUTH OF THE BORDER
ESPECIALLY GIVEN THE DRY NORTHERLY SURFACE FLOW. HAVE MAINTAINED
JUST 20 TO OCCASIONALLY 30 POPS ACROSS OUR SOUTHERN COUNTIES WITH
NOTHING OF ANY CONSEQUENCE ANTICIPATED. MEANWHILE TEMPERATURES
WILL BE CONSIDERABLY COOLER THURSDAY AND FRIDAY...BUT LOWS SHOULD
REMAIN IN THE 40S EACH MORNING WITH NO FROST EXPECTED AT THIS
TIME.
BY EARLY SATURDAY MORNING THE LARGE 500 MB RIDGE AXIS WILL
APPROACH IOWA...MOVING OVERHEAD DURING THE DAY SATURDAY AND
HERALDING A SIGNIFICANT CHANGE IN THE SYNOPTIC REGIME FOR THE
LATTER HALF OF THE WEEKEND AND INTO NEXT WEEK. THE SURFACE HIGH
WILL MOVE OFF TO THE EAST RESULTING IN A RETURN OF SOUTHEAST TO
SOUTH SURFACE FLOW AND HIGHER DEWPOINTS...CONCURRENT WITH A 500 MB
SHORTWAVE RIDING UP RIGHT BEHIND THE RIDGE AXIS AND PROMOTING
THUNDERSTORM DEVELOPMENT ACROSS THE AREA AROUND SATURDAY NIGHT
WITH POPS IN THE 40S AND 50S FORECAST DUE TO MINOR TIMING
DISCREPANCIES IN THESE FEATURES. AFTER THIS INITIAL SURGE OF
PRECIPITATION IN A WARM ADVECTION REGIME CLEARS OUT TO THE
NORTHEAST ON SUNDAY THERE WILL BE A BRIEF WINDOW FOR MID LEVEL
RIDGING TO BUILD BACK OVERHEAD WITH A PROBABLE DRY PERIOD AROUND
SUNDAY NIGHT...HOWEVER CONCURRENTLY A LARGE 500 MB CUTOFF LOW WILL
BE MOVING INTO THE CENTRAL HIGH PLAINS NEAR THE COLORADO/KANSAS
BORDER AND SUBSEQUENTLY NORTHEASTWARD TOWARD IOWA. THIS WILL
LIKELY RESULT IN PRETTY WET WEATHER ACROSS OUR FORECAST AREA
AROUND MONDAY AND TUESDAY OF NEXT WEEK ALTHOUGH THERE ARE STILL
SOME DIFFERENCES IN THE TRACK AND TIMING OF THE LOW AMONG THE
LONGER RANGE PROGNOSTIC MODELS. ALL IN ALL IT WILL BE A SOMEWHAT
WETTER PERIOD FROM LATE SATURDAY TO THE MIDDLE OF NEXT
WEEK...HOWEVER THE SEVERE WEATHER PROBABILITY APPEARS RELATIVELY
LOW FOR THE SEASON AND THE RAIN WILL MOSTLY BE CONFINED TO THESE
TWO PERIODS...ONE FROM SATURDAY AFTERNOON INTO EARLY SUNDAY
MORNING AND THE SECOND FROM MONDAY THROUGH TUESDAY. THESE DETAILS
WILL LIKELY BECOME BETTER REFINED OVER THE NEXT FEW DAYS.
&&
.AVIATION...21/06Z
ISSUED AT 1204 AM CDT WED MAY 21 2014
LINGERING STORMS IN THE SOUTHEAST NEAR KOTM THROUGH 08Z OTHERWISE
VFR CONDITIONS EXPECTED DURING THE PERIOD. NORTH WINDS INCREASE
AFT 15Z WITH GUSTS TO NEAR 20KTS ACROSS NORTHERN PORTIONS AS
COOLER AIR AND HIGH PRESSURE BUILDS SOUTH DURING THE PERIOD. WINDS
SHOULD DIMINISH AFT 23Z. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...REV
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1206 AM CDT WED MAY 21 2014
.SYNOPSIS...
ISSUED AT 302 PM CDT TUE MAY 20 2014
COLD FRONT ACROSS IOWA WILL MOVE SOUTH OF THE STATE BY WED MORNING
AND BECOME STATIONARY TO THE SOUTH. HIGH PRESSURE EXPECTED TO
RIDGE INTO THE NORTH CENTRAL U.S. AND SETTLE OVER THE GREAT LAKES
BY THE WEEKEND. HIGH WILL FINALLY MOVE OFF SUNDAY WITH A
DEVELOPING FRONTAL SYSTEM IN THE ROCKIES MOVING TOWARD THE AREA
SUNDAY AND MONDAY.
&&
.SHORT TERM /TONIGHT/...
ISSUED AT 302 PM CDT TUE MAY 20 2014
BRIEF WINDOW FOR SEVERE CONVECTION LATE AFTERNOON INTO
THE EARLY EVENING HOURS AS STORMS WILL BE HIGHLY DEPENDENT ON
DAYTIME HEATING. FRONT REMAINS LAID UP ACROSS CENTRAL IOWA AND IS
ORIENTED FROM SW IOWA TOWARDS WATERLOO. VERY LITTLE...IF ANY SURFACE
CONVERGENCE OVER CENTRAL IOWA...WITH SOME CONVERGENCE PRESENT ACROSS
SOUTHWEST IOWA. AS OF 19Z...CAP IS BEGINNING TO SHOW SIGNS OF
ERODING AND MUCAPE VALUES HAVE INCREASED TO 2000 J/KG ACROSS
CENTRAL TO SOUTHERN IOWA. HOWEVER...THERE IS ABSOLUTELY NO 0-1KM BULK
SHEAR PRESENT AND THE DEEP LAYER SHEAR IS MARGINAL FOR SUSTAINABLE
UPDRAFTS. DCAPE VALUES RANGE FROM 900 TO 1100 J/KG ALONG AND SOUTH
OF THE FRONT...SO DOWNBURST THREAT IS VIABLE. IF STORMS DO
DEVELOP...STILL ANTICIPATING THE MAIN THREAT TO BE LARGE HAIL AND
DAMAGING WINDS. THE 20.15Z HOPWRF KEEPS CONVECTION INITIATION IN
EASTERN IOWA...WHILE THE 20.17Z HRRR IS MORE BULLISH WITH THE
CONVECTION DEVELOPING OVER WESTERN IOWA. THE SPC 20.12Z 4KM WRF
SEEMED LIKE A DECENT BLEND BETWEEN THE TWO. REGARDLESS...AS
MENTIONED...STORMS WILL BE HIGHLY SUNSHINE DEPENDENT AND NOT
EXPECTING CONVECTION TO LAST MUCH LATER THAN 02Z...WINDOW OF SEVERE
WEATHER OPPORTUNITY WILL BE FROM 21Z TO 02Z. HAVE SEVERE MENTION FOR
LIKELY POPS DURING THE AFOREMENTIONED TIME FRAME AND WENT DRY PAST
06Z TONIGHT FOR THE ENTIRE FORECAST AREA.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
ISSUED AT 302 PM CDT TUE MAY 20 2014
HIGH PRESSURE WILL NOSE INTO IOWA ON WEDNESDAY AND DOMINATE THE
WEATHER ACROSS THE STATE THROUGH THE REST OF THE WEEK. HIGH IS
LIKELY TO BECOME ANCHORED FOR A WHILE OVER THE COLD GREAT LAKES.
TYPICAL OF THIS TIME OF THE YEAR...BUT EVEN MORE LIKELY THIS YEAR
GIVEN THE COLDER THAN NORMAL WATER TEMPS AND THE PATTERN NOT IN AN
OVERLY PROGRESSIVE STATE.
AS THE HIGH BEGINS TO MOVE OFF AND LOSE ITS INFLUENCE
THUNDERSTORMS THAT WILL BE BRUSHING THE FAR SOUTHWEST PART OF IOWA
WILL BEGIN ADVANCING EAST. MODELS HAVE COME INTO CLOSER AGREEMENT
WITH THE OVERALL PROGRESSION. UPPER LOW WILL IMPINGE ON THE UPPER
RIDGE ADVERTISED IN THE MODELS IS ACCEPTED. A MILD AND WET PERIOD
IS ON TAP LOOKING AT THE BULK OF NEXT WEEK WITH THE SLOW MOVING
UPPER SYSTEM AND A NEGATIVE PNA SETTING UP.
&&
.AVIATION...21/06Z
ISSUED AT 1204 AM CDT WED MAY 21 2014
LINGERING STORMS IN THE SOUTHEAST NEAR KOTM THROUGH 08Z OTHERWISE
VFR CONDITIONS EXPECTED DURING THE PERIOD. NORTH WINDS INCREASE
AFT 15Z WITH GUSTS TO NEAR 20KTS ACROSS NORTHERN PORTIONS AS
COOLER AIR AND HIGH PRESSURE BUILDS SOUTH DURING THE PERIOD. WINDS
SHOULD DIMINISH AFT 23Z. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MS MAY 14
SHORT TERM...PODRAZIK
LONG TERM...MS MAY 14
AVIATION...REV
AREA FORECAST DISCUSSION
NWS GOODLAND KS
926 PM MDT THU MAY 22 2014
.UPDATE...
ISSUED AT 923 PM MDT THU MAY 22 2014
UPDATED GRIDS AND ZONES FOR THE CANCELLATION OF SEVERE
THUNDERSTORM WATCH 177. LATEST HRRR AND RADAR TRENDS INDICATE A
RELATIVELY SLOW MOVING AREA OF RAIN OVER EASTERN COLORADO AND
NORTHWEST KANSAS. FOR THIS REASON LOWERED POPS TO HIGH CHANCE IN
THE EASTERN FA FOR OVERNIGHT. ALSO INCLUDED PATCHY FOG FOR THE
OVERNIGHT PERIOD WITH A PATTERN SIMILAR TO LAST NIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 148 PM MDT THU MAY 22 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS LARGE CLOSED UPPER OVER
SOUTHERN CALIFORNIA WITH RIDGE ACROSS PLAINS AND SOUTHEASTERN US.
SOUTHERLY/DIFLUENT FLOW IS IN PLACE ACROSS THE SOUTHERN PLAINS AND
ROCKIES WITH MOIST PLUME EXTENDING FROM PACIFIC NORTH WITHIN THIS
FLOW. AT THE SURFACE A STALLED FRONT IS ANALYZED ACROSS SOUTHERN KS
AND ACROSS OK/TX PANHANDLES. UPSTREAM RADARS SHOW THUNDERSTORM
ACTIVITY ALREADY DEVELOPING ACROSS NORTHEAST NEW MEXICO AND ALONG
THE FRONT RANG WITH A NORTHERLY PROGRESSION.
UPPER LEVEL ENERGY ROTATING THROUGH THE UPPER FLOW ON THE EASTERN
EDGE OF THE UPPER TROUGH WE WILL CONTINUE TO SUPPORT
SHOWER/THUNDERSTORM DEVELOPMENT. ANOMALOUSLY MOIST AIR MASS (PWATS
TWO STANDARD DEVIATIONS ABOVE NORMAL) WILL LINGER TONIGHT THROUGH
TOMORROW.
FOR TONIGHT...THUNDERSTORMS ARE DEVELOPING IN PROXIMITY TO LARGE
SCALE DIFLUENT FLOW OVER NEW MEXICO AND CENTRAL COLORADO. TD VALUES
AROUND 60F HAS LEAD TO SBCAPE 1500-2000 J/KG. GUIDANCE SHOWS MUCAPE
THROUGH FRIDAY AROUND 2000 J/KG OVER OUR CWA. GUIDANCE SUPPORTS
THUNDERSTORM ACTIVITY UPSTREAM FROM OUR CWA MERGING INTO
CLUSTER/THUNDERSTORM COMPLEX AND SPREADING NORTH INTO OUR CWA. WITH
ELEVATED FRONTAL ZONE GENERALLY LINGERING NEAR THE I-70 CORRIDOR AND
MOISTURE POOLING/INSTABILITY LINGERING WE SHOULD SEE A GOOD PATTERN
FOR THIS ACTIVITY INCREASING IN COVERAGE. 0-6KM WIND IS 15KT OR
LESS...HOWEVER WIND PROFILES BELOW 800MB ARE VERY WEAK ALONG FRONTAL
ZONE OUT OF THE EAST...WHILE 400-250MB WINDS ARE STRAIGHT OUT OF THE
WEST. IN ADDITION TO THE ALREADY WET SIGNAL THIS PATTERN SUPPORTS
BACK BUILDING OF THUNDERSTORMS ALONG FRONTAL ZONE AND VERY SLOW
PROPAGATION OF THUNDERSTORMS. CONFIDENCE IS INCREASING IN AT LEAST A
LOCALIZED FLOODING THREAT TONIGHT...BUT I AM NOT SURE HOW WIDESPREAD
THIS WILL BE SO I AM HOLDING OFF ON ISSUANCE OF FLASH FLOOD WATCH.
SHEER PROFILES ARE NOT THAT IMPRESSIVE...HOWEVER WITH MODERATE
INSTABILITY/GOOD MID LEVEL LAPSE RATES...DAMAGING WINDS ASSOCIATED
WITH COLD POOL DRIVEN THUNDERSTORM COMPLEXES OR STRONG WIND/LARGE
HAIL WITH PULSE TYPE CONVECTION CANT BE RULED OUT.
GUIDANCE SHOWS GOOD 850MB SUPPORT LINGERING OVERNIGHT AND MODELS
CONTINUE TO LINGER SHOWERS/THUNDERSTORMS THROUGH TOMORROW
AFTERNOON...WITH AN ENHANCEMENT IN ACTIVITY AS SURFACE FRONT STALLS
ALONG KS/NE STATE LINE. I WAS COMFORTABLE LINGERING POPS ACROSS THE
CWA THROUGH THE SHORT TERM PERIOD...THOUGH I DID TRY TO TIME OUT THE
PERIODS BETWEEN WEAK SHORTWAVES FOR POSSIBLE LULLS IN COVERAGE. I
ALSO BUMPED UP QPF TO REFLECT PERIODS OF MODERATE-HEAVY PRECIP
POTENTIAL. THERE IS ALSO SOME POTENTIAL FOR FOG DEVELOPMENT LATE
TONIGHT/EARLY FRIDAY...HOWEVER SURFACE PATTERN COULD BE CHAOTIC IF
THUNDERSTORM ACTIVITY IS ONGOING...AND DECIDED NOT TO INCLUDE
MENTION WITH THIS UPDATE. TEMPS TONIGHT AND FRIDAY ARE TRICKY AS
MODELS WOULD SUPPORT SHOWERS/THUNDERSTORMS ACROSS THE REGION THROUGH
THESE PERIODS...AND FRONTAL POSITION IS STILL UNCERTAIN.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 328 PM MDT THU MAY 22 2014
MAIN FORECAST CONCERNS HOW LONG WILL UPCOMING WET PERIOD LAST AND
HOW MUCH WE WILL GET DURING THIS TIME WHICH LEAD TO HYDRO ISSUES.
SATELLITE SHOWING AN AMPLIFIED PATTERN FROM THE PACIFIC INTO NORTH
AMERICA. FOR OUR AREA SITUATION FOR THE FORESEEABLE FUTURE WILL BE
CONTROLLED BY SPEED AND LOCATION OF UPPER LOW NOW CUTTING OVER THE
SOUTHWEST PORTION OF THE COUNTRY. FLOW BEHIND THIS SYSTEM ALONG
WITH STRONGER JET WINDS AND HEIGHT FALLS TO ITS SOUTH SHOWING SLOW
MOVEMENT AND A FURTHER SOUTH MOVEMENT WILL CONTINUE. STATIONARY
FRONT CONTINUES TO BE TO OUR SOUTH AND WEST WITH THE SOUTHERN
POSITION ROUGHLY ALONG THE KANSAS BORDER.
AT JET LEVEL...MODELS APPEARED TO DO FINE. AT MID LEVELS...THE
MODELS TENDED TO BE TOO FAR SOUTH AND EAST WITH THE SOUTHWEST UPPER
LOW. HERE AND OVERALL THE UKMET WAS DOING A LITTLE BETTER THAN THE
GFS AND CANADIAN. THE NAM WAS DOING A LITTLE BETTER THAN THE ECMWF
ON THE SURFACE WIND AND PRESSURE FIELD. THE GFS WAS DOING A LITTLE
BETTER THAN THE CANADIAN AND SREF ON THE LOW LEVEL THERMAL FIELD.
FRIDAY NIGHT...CONTINUATION OF WHAT IS STARTING DURING THE DAY.
LARGE AREA OF THUNDERSTORMS/HEAVY RAINFALL MOVES ACROSS THE AREA
FROM SOUTHWEST TO NORTHEAST. IT LOOKS LIKE THERE SHOULD BE A LULL IN
THE PRECIPITATION TOWARD THE END OF THE NIGHT. AT THAT TIME...MODELS
ARE SHOWING A NEARLY SATURATED BOUNDARY LAYER AIR MASS. IF NO
RAINFALL IS OCCURRING THERE LOOKS LIKE THERE WILL BE A GOOD CHANCE
OF AREAS OF FOG DEVELOPING.
SATURDAY/SATURDAY NIGHT...AFTER OVERNIGHT SHORTWAVE TROUGH MOVES
THROUGH THE MID LEVELS DRY OUT AND SHOULD HAVE A BRIEF TIME PERIOD
WHERE LITTLE TO NO PRECIPITATION SHOULD BE OCCURRING. AREAS OF FOG
SHOULD CONTINUE THROUGH THE MORNING. MODELS ARE IN GENERAL
AGREEMENT OF HAVING THE UPPER LOW NEAR THE ARIZONA/NEW MEXICO
BORDER BY LATE IN THE AFTERNOON. ANOTHER SHORTWAVE ROTATES IN FROM
THE SOUTH AS DIFLUENT FLOW ALOFT MOVES OVER THE AREA. MODELS ARE
TRYING TO DRY OUT THE AIR MASS WITH THIS FLOW IN PLACE AND AM NOT
BUYING THIS RIGHT NOW. SHOULD BE ANOTHER ROUND OF THUNDERSTORMS
WITH MODERATE TO HEAVY RAINFALL.
SUNDAY...SOME DIFFERENCE ON POSITION OF THE UPPER LOW IS SHOWN BY
THE ENSEMBLES AND DETERMINISTIC MODELS WHICH AFFECTS MANY THINGS BUT
UPPER JET LOOKS TO BE NEAR OR OVER THE WESTERN HALF OF THE AREA.
AREA IS STILL IN SOUTHERLY FLOW ALOFT WITH LOW LEVEL ALSO
CONTINUING TO BRING IN MOISTURE. A SHORTWAVE ROTATES THROUGH THIS
WHILE A UPPER JET AXIS ESTABLISHES ITSELF OVER THE WESTERN HALF OF
THE AREA. ONCE AGAIN MODELS ARE SHOWING THE AIR MASS DRYING AND AM
NOT SURE ABOUT THAT. THERE SHOULD BE A CONTINUED CHANCE OF
THUNDERSTORMS.
SUNDAY NIGHT THROUGH THURSDAY...MODEL HANDLING OF UPPER LOW BY
ENSEMBLES AND DETERMINISTIC OUTPUT ARE SHOWING DIFFERENCES. ALTHOUGH
THERE IS A GENERAL TENDENCY OF SLOWING THE LOW OR KEEPING IT NEARLY
STATIONARY SUNDAY NIGHT INTO MONDAY WITH A BETTER AGREEMENT IN
HAVING THE CIRCULATION FURTHER SOUTH. MODELS ACTUALLY TAKE THIS
SYSTEM THROUGH MONDAY INTO MONDAY NIGHT IN A FAVORABLE POSITION TO
BE IN WRAP AROUND/MID LEVEL DEFORMATION ZONE. ALL THESE DIFFERENCES
NOT SURPRISING WITH THIS SINCE MODELS USUALLY DO HAVE A PROBLEM WITH
THESE KIND OF SYSTEMS AND THIS IS RATHER UNUSUAL FOR THIS TIME OF
YEAR.
THE CRH_INIT GAVE ME CHANCE POPS SUNDAY NIGHT INTO MONDAY WITH
SLIGHT CHANCES GIVEN MONDAY NIGHT. AM CONCERNED THAT THIS PERIOD
COULD END UP BEING WETTER...ESPECIALLY MONDAY AND MONDAY NIGHT. AM
CONTENT RIGHT NOW IN LEAVING THIS AS IS SINCE THERE ARE HIGH CHANCE
POPS IN THERE. WITH THAT MONDAY HIGH TEMPERATURES COULD BE COOLER
AND OVERALL MAY NOT BE THE MOST PLEASANT MEMORIAL DAY. BY THE TIME
MONDAY ENDS...A SUBSTANTIAL AMOUNT OF PRECIPITATION SINCE TODAY
COULD HAVE OCCURRED AND MAY BE EXPERIENCING HYDRO PROBLEMS THROUGH
MOST OF THIS PERIOD.
ON TUESDAY...MODELS STILL NOT SHOWING THE SYSTEM NOT TOO FAR TO THE
EAST AND SOUTH AT THE BEGINNING OF THE DAY. THIS DAY COULD DEFINITELY
BE COOLER AND WETTER AS WELL BUT EVERYONE IS CONTENT IN LEAVING AS IS
AND DO NOT BLAME THEM WITH THE MODEL DIFFERENCES. THERE IS SOME
MOVEMENT TO THE SOUTH AND EAST THROUGH TUESDAY NIGHT.
PROBABLY THE MOST UNCERTAIN TIME PERIOD IS WEDNESDAY INTO THURSDAY.
THE ECMWF AND GFS MOVE THE SYSTEM ABOUT THE SAME AMOUNT TO THE
EAST. HOWEVER...THE GFS IS FURTHER SOUTH. THE GFS HAS MORE RIDGING
OVER OUR AREA THAN THE ECMWF. THE ECMWF EVEN STARTS TO RETROGRADE
THE SYSTEM A LITTLE DURING THIS TIME PERIOD. THE AIR MASS STILL LOOKS
MOIST ENOUGH TO SUPPORT CONVECTION WITH SOME SHORTWAVE TROUGHS MOVING
THROUGH WITH THE ECMWF LOOKING A LITTLE MORE FAVORABLE. CRH_INIT
DOES HAVE SOME LOW CHANCE POPS IN THERE FROM LATE WEDNESDAY INTO
THURSDAY. THIS MAY BE A BIT WET BUT THIS IS CONVECTIVE SEASON AND
THESE POPS ACTUALLY FIT CLIMATOLOGY. SO NOT ONLY DID I NOT CHANGE
ANY OF THE POPS BUT OVERALL CHANGED NOTHING ELSE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 527 PM MDT THU MAY 22 2014
CURRENT RADAR TRENDS AND HRRR INDICATE THAT THUNDERSTORMS SHOULD
IMPACT KGLD EARLY THIS EVENING AND THEN PROGRESS TO KMCK BY LATE
EVENING. SCATTERED SHOWERS WILL CONTINUE OVERNIGHT WITH STRATUS
AND FOG DEVELOPING AT BOTH SITES BRINGING CONDITIONS DOWN TO MVFR.
FOG SHOULD DISSIPATE BY MID MORNING WITH VFR CONDITIONS RETURNING.
MORE THUNDERSTORMS WILL BE POSSIBLE AT BOTH SITES FRIDAY
AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...FS
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...FS
AREA FORECAST DISCUSSION
NWS WICHITA KS
642 PM CDT THU MAY 22 2014
...UPDATED FOR 00Z AVIATION DISCUSSION...
.UPDATE...
ISSUED AT 641 PM CDT THU MAY 22 2014
OVERALL...INTENSITY OF THE CONVECTION CONTINUES TO DECREASE AS
DIURNAL HEATING IS LOST FOR THE DAY. THE 21Z HRRR SHOWS AN AREA OF
STORMS THAT EXPANDS OVER THE HIGH PLAINS OVERNIGHT. ACCORDING TO
THE MODEL...THIS CAUSES OUTFLOW TO MOVE EAST AND PRODUCES
CONVECTION ACROSS THE FORECAST AREA AFTER 09Z.
GIVEN THERE ARE SO MANY BOUNDARIES LAYING AROUND AND THAT WE ARE
IN A WEAK FLOW SITUATION...CONFIDENCE IN ANY SUCH SOLUTION IS VERY
LOW. AT THIS TIME...THERE IS NO REASON TO DEVIATE FROM CURRENT
FORECAST.
COOK
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 325 PM CDT THU MAY 22 2014
LATE AFTERNOON/EARLY THIS EVENING
PERSISTENT CONVECTION FROM EARLIER THIS MORNING WENT UPSCALE
ALONG THE ASSOCIATED OUTFLOW ACROSS THE FLINT HILLS EARLY THIS
AFTERNOON. INTERSECTION OF STORM ON MESOSCALE OUTFLOW AND THE
SYNOPTIC STATIONARY FRONT APPARENTLY PRODUCED BRIEF ROPE TORNADO
EAST OF ROSALIA NEAR GREENWOOD/BUTLER COUNTY LINE. SPC MESO
DATA SHOWED MLCAPE OF 1500-2000 J/KG WITH SOME LOW LEVEL CAPE
AIDING INITIAL UPDRAFTS. THIS CONVECTION WAS ASSOCIATED WITH
RESIDUAL WEAK MESO VORT AND SHOULD CONTINUE TO FOSTER STORMS
IN THE WARM/UNSTABLE AIRMASS INTO THE EARLY EVENING ACROSS
SOUTHEAST KANSAS AND THE FLINT HILLS.
LATER TONIGHT THROUGH SUNDAY
ADDITIONAL CONVECTION IS EXPECTED ACROSS THE HIGH PLAINS WHICH
MAY SUPPORT A COUPLE COMPLEX OF STORMS OVERNIGHT. WEAK STEERING
FLOW WILL MAKE IT A BIT DIFFICULT TO PORTEND WHERE CONVECTION
MAY IMPACT THE FORECAST AREA. HOWEVER WILL SHOW A GENERAL
UP-TWEAK WITH MODEST POPS OVERNIGHT ACROSS THE ENTIRE AREA.
THE SHORT TERM MODELS ARE SOMEWHAT MORE IN AGREEMENT WITH A
SIGNAL FOR ORGANIZED CONVECTION TO AFFECT MUCH OF THE AREA
LATE FRIDAY INTO EARLY SATURDAY...AND WILL SHOW RELATIVELY
HIGHER POPS IN THESE TIME PERIODS. OTHERWISE...WITH LITTLE OR
NO CAPPING THROUGH SATURDAY...CHANCES FOR CONVECTION WILL REMAIN
IN THE FORECAST ALONG THE QUASI-STATIONARY FRONT. THIS FRONT
WILL WEAKEN AS IT SHIFTS NORTH DURING SUNDAY WITH INCREASING
SOUTHERLY FLOW ACROSS THE AREA. FOCUS FOR MORE ORGANIZED
CONVECTION SHOULD BE SITUATED ACROSS WESTERN KANSAS DURING THE
AFTERNOON., HOWEVER AS A SHORTWAVE EJECTS OUT ACROSS THE AREA
INTO SUNDAY NIGHT...BETTER CHANCES FOR CONVECTION SHOULD
AGAIN TRANSLATE EAST ACROSS MUCH OF THE AREA.
TEMPERATURES WILL REMAIN A LITTLE BIT ABOVE SEASONAL CLIMO
THOUGH NOT NEARLY AS HOT AS RECENT DAYS.
DARMOFAL
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 325 PM CDT THU MAY 22 2014
THE MAIN CHALLENGE IS THE HANDLING OF THE REMNANT CLOSED
UPPER LOW ACROSS THE PLAINS THROUGH EARLY NEXT WEEK. THE
ECMWF HOLDS ON TO THIS A BIT LONGER WHICH WOULD LINGER
PRECIP/CONVECTIVE CHANCES ACROSS SOUTHEAST KANSAS. FOR NOW
WILL MAKE LITTLE CHANGE TO THE GOING FORECAST.
KED
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 641 PM CDT THU MAY 22 2014
CONVECTION CONTINUES TO DECREASE IN AREAL COVERAGE AND INTENSITY
ACROSS THE AREA. CIRRUS DEBRIS WILL OVERSPREAD THE AREA AND SHOULD
REMAIN OVERNIGHT. THIS SHOULD PRECLUDE ANY FOG DEVELOPMENT...WHICH
IS COUNTER TO WHAT STATISTICAL GUIDANCE IS PRODUCING.
THE 21Z HRRR SHOWS CONVECTION INCREASING IN AREAL COVERAGE ACROSS
THE HIGH PLAINS OVERNIGHT. OUTFLOW FROM THESE STORMS IS FORECAST
BY THE HRRR TO MOVE EAST AND CAUSE CONVECTION AFTER 09Z WEST OF
INTERSTATE 135...AND AFTER 11Z EAST OF IT. VERY UNSURE THIS WILL
COME TO FRUITION GIVEN THE UNCERTAINTY OF THE PATTERN. THUS HAVE
REMOVED ALL MENTION OF CONVECTION FROM THE TAFS OVERNIGHT.
FRIDAY AGAIN PRESENTS ITSELF WITH ANOTHER CHANCE OF CONVECTION.
THE MOSTLY LIKELY TIME IS AFTER 19Z ACROSS THE ENTIRE REGION.
OUTFLOW BOUNDARIES TONIGHT AND TOMORROW WILL CAUSE OCCASIONAL WIND
CHANGES...BUT SPEEDS SHOULD REMAIN 10 KNOTS OR LESS.
COOK
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 66 82 65 81 / 40 50 60 50
HUTCHINSON 64 80 64 81 / 50 50 60 50
NEWTON 64 80 64 80 / 40 50 60 60
ELDORADO 64 80 64 80 / 40 50 60 60
WINFIELD-KWLD 66 83 65 82 / 40 50 50 50
RUSSELL 62 78 62 81 / 40 40 60 50
GREAT BEND 63 78 63 80 / 50 40 60 50
SALINA 63 80 64 81 / 40 40 60 50
MCPHERSON 64 80 64 80 / 40 50 60 50
COFFEYVILLE 67 83 66 83 / 60 40 40 50
CHANUTE 65 81 65 81 / 50 40 40 50
IOLA 64 80 65 80 / 50 40 40 60
PARSONS-KPPF 66 83 65 82 / 70 40 40 50
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
534 PM MDT THU MAY 22 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 148 PM MDT THU MAY 22 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS LARGE CLOSED UPPER OVER
SOUTHERN CALIFORNIA WITH RIDGE ACROSS PLAINS AND SOUTHEASTERN US.
SOUTHERLY/DIFLUENT FLOW IS IN PLACE ACROSS THE SOUTHERN PLAINS AND
ROCKIES WITH MOIST PLUME EXTENDING FROM PACIFIC NORTH WITHIN THIS
FLOW. AT THE SURFACE A STALLED FRONT IS ANALYZED ACROSS SOUTHERN KS
AND ACROSS OK/TX PANHANDLES. UPSTREAM RADARS SHOW THUNDERSTORM
ACTIVITY ALREADY DEVELOPING ACROSS NORTHEAST NEW MEXICO AND ALONG
THE FRONT RANG WITH A NORTHERLY PROGRESSION.
UPPER LEVEL ENERGY ROTATING THROUGH THE UPPER FLOW ON THE EASTERN
EDGE OF THE UPPER TROUGH WE WILL CONTINUE TO SUPPORT
SHOWER/THUNDERSTORM DEVELOPMENT. ANOMALOUSLY MOIST AIR MASS (PWATS
TWO STANDARD DEVIATIONS ABOVE NORMAL) WILL LINGER TONIGHT THROUGH
TOMORROW.
FOR TONIGHT...THUNDERSTORMS ARE DEVELOPING IN PROXIMITY TO LARGE
SCALE DIFLUENT FLOW OVER NEW MEXICO AND CENTRAL COLORADO. TD VALUES
AROUND 60F HAS LEAD TO SBCAPE 1500-2000 J/KG. GUIDANCE SHOWS MUCAPE
THROUGH FRIDAY AROUND 2000 J/KG OVER OUR CWA. GUIDANCE SUPPORTS
THUNDERSTORM ACTIVITY UPSTREAM FROM OUR CWA MERGING INTO
CLUSTER/THUNDERSTORM COMPLEX AND SPREADING NORTH INTO OUR CWA. WITH
ELEVATED FRONTAL ZONE GENERALLY LINGERING NEAR THE I-70 CORRIDOR AND
MOISTURE POOLING/INSTABILITY LINGERING WE SHOULD SEE A GOOD PATTERN
FOR THIS ACTIVITY INCREASING IN COVERAGE. 0-6KM WIND IS 15KT OR
LESS...HOWEVER WIND PROFILES BELOW 800MB ARE VERY WEAK ALONG FRONTAL
ZONE OUT OF THE EAST...WHILE 400-250MB WINDS ARE STRAIGHT OUT OF THE
WEST. IN ADDITION TO THE ALREADY WET SIGNAL THIS PATTERN SUPPORTS
BACK BUILDING OF THUNDERSTORMS ALONG FRONTAL ZONE AND VERY SLOW
PROPAGATION OF THUNDERSTORMS. CONFIDENCE IS INCREASING IN AT LEAST A
LOCALIZED FLOODING THREAT TONIGHT...BUT I AM NOT SURE HOW WIDESPREAD
THIS WILL BE SO I AM HOLDING OFF ON ISSUANCE OF FLASH FLOOD WATCH.
SHEER PROFILES ARE NOT THAT IMPRESSIVE...HOWEVER WITH MODERATE
INSTABILITY/GOOD MID LEVEL LAPSE RATES...DAMAGING WINDS ASSOCIATED
WITH COLD POOL DRIVEN THUNDERSTORM COMPLEXES OR STRONG WIND/LARGE
HAIL WITH PULSE TYPE CONVECTION CANT BE RULED OUT.
GUIDANCE SHOWS GOOD 850MB SUPPORT LINGERING OVERNIGHT AND MODELS
CONTINUE TO LINGER SHOWERS/THUNDERSTORMS THROUGH TOMORROW
AFTERNOON...WITH AN ENHANCEMENT IN ACTIVITY AS SURFACE FRONT STALLS
ALONG KS/NE STATE LINE. I WAS COMFORTABLE LINGERING POPS ACROSS THE
CWA THROUGH THE SHORT TERM PERIOD...THOUGH I DID TRY TO TIME OUT THE
PERIODS BETWEEN WEAK SHORTWAVES FOR POSSIBLE LULLS IN COVERAGE. I
ALSO BUMPED UP QPF TO REFLECT PERIODS OF MODERATE-HEAVY PRECIP
POTENTIAL. THERE IS ALSO SOME POTENTIAL FOR FOG DEVELOPMENT LATE
TONIGHT/EARLY FRIDAY...HOWEVER SURFACE PATTERN COULD BE CHAOTIC IF
THUNDERSTORM ACTIVITY IS ONGOING...AND DECIDED NOT TO INCLUDE
MENTION WITH THIS UPDATE. TEMPS TONIGHT AND FRIDAY ARE TRICKY AS
MODELS WOULD SUPPORT SHOWERS/THUNDERSTORMS ACROSS THE REGION THROUGH
THESE PERIODS...AND FRONTAL POSITION IS STILL UNCERTAIN.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 328 PM MDT THU MAY 22 2014
MAIN FORECAST CONCERNS HOW LONG WILL UPCOMING WET PERIOD LAST AND
HOW MUCH WE WILL GET DURING THIS TIME WHICH LEAD TO HYDRO ISSUES.
SATELLITE SHOWING AN AMPLIFIED PATTERN FROM THE PACIFIC INTO NORTH
AMERICA. FOR OUR AREA SITUATION FOR THE FORESEEABLE FUTURE WILL BE
CONTROLLED BY SPEED AND LOCATION OF UPPER LOW NOW CUTTING OVER THE
SOUTHWEST PORTION OF THE COUNTRY. FLOW BEHIND THIS SYSTEM ALONG
WITH STRONGER JET WINDS AND HEIGHT FALLS TO ITS SOUTH SHOWING SLOW
MOVEMENT AND A FURTHER SOUTH MOVEMENT WILL CONTINUE. STATIONARY
FRONT CONTINUES TO BE TO OUR SOUTH AND WEST WITH THE SOUTHERN
POSITION ROUGHLY ALONG THE KANSAS BORDER.
AT JET LEVEL...MODELS APPEARED TO DO FINE. AT MID LEVELS...THE
MODELS TENDED TO BE TOO FAR SOUTH AND EAST WITH THE SOUTHWEST UPPER
LOW. HERE AND OVERALL THE UKMET WAS DOING A LITTLE BETTER THAN THE
GFS AND CANADIAN. THE NAM WAS DOING A LITTLE BETTER THAN THE ECMWF
ON THE SURFACE WIND AND PRESSURE FIELD. THE GFS WAS DOING A LITTLE
BETTER THAN THE CANADIAN AND SREF ON THE LOW LEVEL THERMAL FIELD.
FRIDAY NIGHT...CONTINUATION OF WHAT IS STARTING DURING THE DAY.
LARGE AREA OF THUNDERSTORMS/HEAVY RAINFALL MOVES ACROSS THE AREA
FROM SOUTHWEST TO NORTHEAST. IT LOOKS LIKE THERE SHOULD BE A LULL IN
THE PRECIPITATION TOWARD THE END OF THE NIGHT. AT THAT TIME...MODELS
ARE SHOWING A NEARLY SATURATED BOUNDARY LAYER AIR MASS. IF NO
RAINFALL IS OCCURRING THERE LOOKS LIKE THERE WILL BE A GOOD CHANCE
OF AREAS OF FOG DEVELOPING.
SATURDAY/SATURDAY NIGHT...AFTER OVERNIGHT SHORTWAVE TROUGH MOVES
THROUGH THE MID LEVELS DRY OUT AND SHOULD HAVE A BRIEF TIME PERIOD
WHERE LITTLE TO NO PRECIPITATION SHOULD BE OCCURRING. AREAS OF FOG
SHOULD CONTINUE THROUGH THE MORNING. MODELS ARE IN GENERAL
AGREEMENT OF HAVING THE UPPER LOW NEAR THE ARIZONA/NEW MEXICO
BORDER BY LATE IN THE AFTERNOON. ANOTHER SHORTWAVE ROTATES IN FROM
THE SOUTH AS DIFLUENT FLOW ALOFT MOVES OVER THE AREA. MODELS ARE
TRYING TO DRY OUT THE AIR MASS WITH THIS FLOW IN PLACE AND AM NOT
BUYING THIS RIGHT NOW. SHOULD BE ANOTHER ROUND OF THUNDERSTORMS
WITH MODERATE TO HEAVY RAINFALL.
SUNDAY...SOME DIFFERENCE ON POSITION OF THE UPPER LOW IS SHOWN BY
THE ENSEMBLES AND DETERMINISTIC MODELS WHICH AFFECTS MANY THINGS BUT
UPPER JET LOOKS TO BE NEAR OR OVER THE WESTERN HALF OF THE AREA.
AREA IS STILL IN SOUTHERLY FLOW ALOFT WITH LOW LEVEL ALSO
CONTINUING TO BRING IN MOISTURE. A SHORTWAVE ROTATES THROUGH THIS
WHILE A UPPER JET AXIS ESTABLISHES ITSELF OVER THE WESTERN HALF OF
THE AREA. ONCE AGAIN MODELS ARE SHOWING THE AIR MASS DRYING AND AM
NOT SURE ABOUT THAT. THERE SHOULD BE A CONTINUED CHANCE OF
THUNDERSTORMS.
SUNDAY NIGHT THROUGH THURSDAY...MODEL HANDLING OF UPPER LOW BY
ENSEMBLES AND DETERMINISTIC OUTPUT ARE SHOWING DIFFERENCES. ALTHOUGH
THERE IS A GENERAL TENDENCY OF SLOWING THE LOW OR KEEPING IT NEARLY
STATIONARY SUNDAY NIGHT INTO MONDAY WITH A BETTER AGREEMENT IN
HAVING THE CIRCULATION FURTHER SOUTH. MODELS ACTUALLY TAKE THIS
SYSTEM THROUGH MONDAY INTO MONDAY NIGHT IN A FAVORABLE POSITION TO
BE IN WRAP AROUND/MID LEVEL DEFORMATION ZONE. ALL THESE DIFFERENCES
NOT SURPRISING WITH THIS SINCE MODELS USUALLY DO HAVE A PROBLEM WITH
THESE KIND OF SYSTEMS AND THIS IS RATHER UNUSUAL FOR THIS TIME OF
YEAR.
THE CRH_INIT GAVE ME CHANCE POPS SUNDAY NIGHT INTO MONDAY WITH
SLIGHT CHANCES GIVEN MONDAY NIGHT. AM CONCERNED THAT THIS PERIOD
COULD END UP BEING WETTER...ESPECIALLY MONDAY AND MONDAY NIGHT. AM
CONTENT RIGHT NOW IN LEAVING THIS AS IS SINCE THERE ARE HIGH CHANCE
POPS IN THERE. WITH THAT MONDAY HIGH TEMPERATURES COULD BE COOLER
AND OVERALL MAY NOT BE THE MOST PLEASANT MEMORIAL DAY. BY THE TIME
MONDAY ENDS...A SUBSTANTIAL AMOUNT OF PRECIPITATION SINCE TODAY
COULD HAVE OCCURRED AND MAY BE EXPERIENCING HYDRO PROBLEMS THROUGH
MOST OF THIS PERIOD.
ON TUESDAY...MODELS STILL NOT SHOWING THE SYSTEM NOT TOO FAR TO THE
EAST AND SOUTH AT THE BEGINNING OF THE DAY. THIS DAY COULD DEFINITELY
BE COOLER AND WETTER AS WELL BUT EVERYONE IS CONTENT IN LEAVING AS IS
AND DO NOT BLAME THEM WITH THE MODEL DIFFERENCES. THERE IS SOME
MOVEMENT TO THE SOUTH AND EAST THROUGH TUESDAY NIGHT.
PROBABLY THE MOST UNCERTAIN TIME PERIOD IS WEDNESDAY INTO THURSDAY.
THE ECMWF AND GFS MOVE THE SYSTEM ABOUT THE SAME AMOUNT TO THE
EAST. HOWEVER...THE GFS IS FURTHER SOUTH. THE GFS HAS MORE RIDGING
OVER OUR AREA THAN THE ECMWF. THE ECMWF EVEN STARTS TO RETROGRADE
THE SYSTEM A LITTLE DURING THIS TIME PERIOD. THE AIR MASS STILL LOOKS
MOIST ENOUGH TO SUPPORT CONVECTION WITH SOME SHORTWAVE TROUGHS MOVING
THROUGH WITH THE ECMWF LOOKING A LITTLE MORE FAVORABLE. CRH_INIT
DOES HAVE SOME LOW CHANCE POPS IN THERE FROM LATE WEDNESDAY INTO
THURSDAY. THIS MAY BE A BIT WET BUT THIS IS CONVECTIVE SEASON AND
THESE POPS ACTUALLY FIT CLIMATOLOGY. SO NOT ONLY DID I NOT CHANGE
ANY OF THE POPS BUT OVERALL CHANGED NOTHING ELSE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 527 PM MDT THU MAY 22 2014
CURRENT RADAR TRENDS AND HRRR INDICATE THAT THUNDERSTORMS SHOULD
IMPACT KGLD EARLY THIS EVENING AND THEN PROGRESS TO KMCK BY LATE
EVENING. SCATTERED SHOWERS WILL CONTINUE OVERNIGHT WITH STRATUS
AND FOG DEVELOPING AT BOTH SITES BRINGING CONDITIONS DOWN TO MVFR.
FOG SHOULD DISSIPATE BY MID MORNING WITH VFR CONDITIONS RETURNING.
MORE THUNDERSTORMS WILL BE POSSIBLE AT BOTH SITES FRIDAY
AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...FS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
634 PM CDT Thu May 22 2014
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Friday)
Issued at 350 PM CDT THU MAY 22 2014
A broad closed upper low was located across southern CA this
afternoon. A minor H5 shortwave trough was lifting northeast across
south central KS and was providing enough ascent for an area of
showers and thunderstorms across east central and central KS.
At the surface an outflow boundary extended from near Fort Scott,
KS, then extended west-northwest to near Cassoday before extending
southwest, east of ICT into northwest OK. The 19Z SPC mesoscale
EMC RUC showed 1500 ML CAPE along and south of the OFB across south
central and southeast KS. The instability decreases across east
central and northeast KS, with MLCAPES less than 500 J/KG along and
north of I-70. The greatest chance for stronger storms this
afternoon and early evening will be along and south of I-35, where
the stronger thunderstorms may produce pea to penny size hail and
wind gusts of 40 to 50 MPH. Across the remainder of east central KS
the greatest hazard will be brief heavy rainfall.
Tonight, once the minor H5 trough lifts northeast into northern MO,
the thunderstorms will push east of the CWA. Thunderstorms
developing across eastern CO late this afternoon will congeal into
one or two complexes of thunderstorms and track east and southeast
across western KS during the evening hours and may move into north
central KS after midnight, then across portions of east central KS
through the early morning hours of Friday. At this time the best
rain chances late tonight will be along and south of a Concordia, to
Manhattan, to Ottawa line, but this will be more of mesoscale
forecast and will depend on where the thunderstorms complexes
develop and how they will track during the evening hours. The
primary hazards from the thunderstorms later tonight will be pea to
penny size hail with locally heavy rainfall.
Friday...after the morning complex of thunderstorms weakens and
shifts east of the CWA, additional thunderstorms will redevelop
along the leftover outflow boundaries during the afternoon hours.
The effective shear looks to be rather weak, so any thunderstorms
that develop across northeast KS Tuesday afternoon should be pulse
storms with the primary hazard being small hail, gusty winds and
brief heavy rainfall. The best chances for thunderstorms Friday
afternoon will occur across the western and southern counties,
closer to the surface outflow boundary/front. Highs on Friday will
be in the mid to upper 70s.
.LONG TERM...(Friday Night through Thursday)
Issued at 350 PM CDT THU MAY 22 2014
The extended forecast will be noted with several chances for showers
and thunderstorms as a very slow-moving system moves through the
region.
By Friday night, models are in very good agreement in having a
closed-off low anchored over the southwestern U.S. and slowly
progress east-northeastward toward the region through the weekend.
As a result, southwesterly flow aloft will prevail with ample
moisture surging into the area. There looks to be a decent chance
for showers and thunderstorms Friday night into Saturday evening as models
suggest a shortwave developing along the lee side of the mid-level
trough and tracking into the area. While models suggest MUCAPE
values could be upwards of 1000-1500 J/kg, 0-6km bulk shear values
continue to look extremely low at less than 20kts. As a result, the
probability of severe weather still looks to be very low, however
cannot completely rule out the slight chance for small hail or some
stronger winds from any stronger storms that develop. The main
concern with this activity will be for heavy rainfall as soundings
show a very deep moist adiabatic profile with PWAT values upwards of
1.50 to 1.75 inches. If these rounds of showers and thunderstorms
end up tracking over the same areas, then we could see some
localized flash flooding.
By the latter part of the weekend into next week, the models
certainly begin to struggle in handling the details of this
approaching system. With that in mind, some models are suggesting
that the region may be between shortwaves Sunday and Sunday night,
so precipitation chances are lower during this period with any
activity likely being more scattered in nature. On Monday, the
mid-level low should be progressing towards western Kansas and the
Texas/Oklahoma panhandles. There looks to be a decent chance for
showers and thunderstorms on Monday as another shortwave tracks near
the area. Beyond Monday, as previously mentioned, the models
struggle with the tracking and timing of any additional shortwaves
as the mid-level low finally tracks over or just south of the area
Tuesday night through Wednesday. Additionally, there are very
notable differences in the tracking of the center of this low, as
the ECMWF keeps it just south of the forecast area with the GFS
having it dive much further south. Due to the large model
uncertainty, made only minor adjustments to the consensus forecast
with slight to low-end chance PoPs in place Monday night through
Wednesday night. The potential for severe storms next week continues
to be low.
Between the prolonged period of cloud cover and not much in the way
of temperature advection, expect temperatures to remain fairly
steady through the period with highs generally in the mid 70s to low
80s and lows in the 60s.
&&
.AVIATION...(For the 00Z TAFs through 00Z Friday Evening)
Issued at 626 PM CDT THU MAY 22 2014
VFR conditions are expected through the evening and into tonight.
There is still some uncertainty with the coverage and timing for
thunderstorms early tomorrow morning. Have left the mention of
VCTS for now.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...Hennecke
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS TOPEKA KS
335 PM CDT Wed May 21 2014
.SHORT TERM...(This Evening through Thursday)
Issued at 311 PM CDT WED MAY 21 2014
Latest surface analysis shows surface trough extending northeast
from a low over the Texas Panhandle to near Topeka then into
northwest Missouri. Dew points have increased to around 66 degrees
to the south of the boundary in east central Kansas. Cu field has
developed along and to the north of the boundary. Convergence was
still weak and capping remains in place as CIN values range from 100
to 200 J/kg at 20Z. 0-6km shear of 40 to 50 kts over the CWA and
shear is forecast to decrease some overnight to around 30 to 40 kts.
Cape was running around 2000-2500 J/kg at late afternoon. If cap is
able to be overcome then isolated thunderstorms could develop and
could become severe with hail and and wind the main Hazards. Have
left small chances for thunderstorms from late afternoon and into
the early evening hours. There does not seem to be any weak waves
that would set anything off. The HRRR and the new 18Z NAM develop
some convection this evening along the frontal boundary and in area
of 850 mb convergence and theta advection. Have increase chances
after 03Z. The next area to watch remains convection moving off the
High Plains and/or developing across south central Kansas. Models
are showing that good moisture transport will focus into central
Kansas by 06Z then veering into northeast Kansas by 12Z with the
increase of the low level jet. Corfidi vectors suggest an eastward
movement to any MCS that would develop out in western Kansas.
Precipitable water values increase to around 1.5 inches along I-70
overnight. Isolated hail and strong winds will be possible with the
MCS as it moves across the state.
Thursday, there still could be some morning convection which will
leave outflow boundaries across the area along with the frontal
boundary. Shear is not as strong as today generally in the
20 to 30 kt range and is less favorable for supercells. There is a
wave that was moving across New Mexico this afternoon that is
progged to be moving into central Kansas on Thursday. Will continue
to keep chance pops going for now. Lows tonight will range from the
lower 60s along the Nebraska border to the upper 60s across east
central Kansas. Highs Thursday will range from the mid 70s in far
northeast Kansas to the mid 80s in east central Kansas.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 311 PM CDT WED MAY 21 2014
The surface front will sag south again Thursday night in wake of
the shortwave trough that will round the upper ridge during the
day Thursday. Proximity of the boundary along with 925-850mb
20-30kt flow moving atop the sfc-850mb boundary could lead to sct
thunderstorms overnight into early Friday. Some low chcs for pops again
Friday although the upper ridge over the area and better low level
focus across western KS suggests chcs are minimal this far east.
Another upper wave will move across the region Friday night into
Saturday so that should bring better chcs for scattered
thunderstorms.
The main upper low will drift into the region Sunday and Monday.
It would appear that Sunday night into Monday would bring the
higher rain chcs as the upper low approaches the area given we
will lack a low level focus both days. The upper low will finally
depart Tuesday so precip chcs will diminish then with a dry
weather expected by mid to late week.
&&
.AVIATION...(For the 18Z TAFs through 18Z Thursday Afternoon)
Issued at 1233 PM CDT WED MAY 21 2014
VFR conditions are expected through the period outside of
convection. Frontal boundary/sfc trough hovering near or just
south of the terminals at the beginning of the period should
slowly move south. hi-resolution models develop some convection
along and south of the front after 22Z. Staying with VCTS for now
after 03Z as confidence is not high on timing. May see a cluster
of storms after 08Z which may affect the terminals through 14Z
keeping vcts going through then.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...Omitt
AVIATION...53
AREA FORECAST DISCUSSION
NWS GOODLAND KS
228 PM MDT WED MAY 21 2014
.SHORT TERM...(THIS AFTERNOON INTO TONIGHT)
ISSUED AT 205 PM MDT WED MAY 21 2014
MAIN CHANGE FOR THIS TIME PERIOD WAS TO SLOW THE ONSET OF
THUNDERSTORM DEVELOPMENT. FRONT WAS DRAPED RATHER FAR SOUTH AND
ALONG THE FRONT RANGE TO THE WEST. AN AREA OF SURFACE CONVERGENCE
EXTENDED FROM KIT CARSON AND CHEYENNE COUNTIES TOWARD THE
NORTHWEST. RATHER STRONG SURFACE WINDS OCCURRING OVER THE AREA AT
THIS TIME. SHORTWAVE TROUGH OVER NEW MEXICO IS EXPECTED TO MOVE
TOWARD THE NORTHEAST THROUGH THE NIGHT WITH A SLUG OF SUBTROPICAL
MOISTURE COMING IN ADVANCE OF IT. ALSO A RIGHT REAR QUADRANT OF
THE JET STARTS OVER THE SOUTHWEST HALF OF THE AREA LATE THIS
AFTERNOON INTO THE EVENING HOURS.
THIS IS ALL STARTING A LITTLE SLOWER THAN WHAT THE EARLIER FORECAST
HAD. AREA RADARS/SATELLITE/LIGHTNING DETECTION SHOW AN AREA/LINE
OF STORMS DEVELOPING FROM SOUTHWEST KANSAS INTO SOUTHEAST COLORADO
TO ALONG THE NORTHERN COLORADO FRONT RANGE. WHERE THE MAIN PROBLEM
IS FOR THIS FORECAST IS THAT THE MODELS DISAGREE ON WHERE TO PUT
THE MAIN SWATCH OF STORMS/QPF. SOME TAKE THE MAIN AREA OVER THE
NORTHWEST HALF...SOME OVER THE SOUTHEAST PORTION CLOSEST TO THE
FRONT AND SOME DO BOTH.
THE HRRR WHICH HAS BEEN DOING WELL RECENTLY HAS TRENDED FROM
TAKING A BROKEN SWATH OF PRECIPITATION FROM SOUTHWEST TO NORTHEAST
ACROSS THE ENTIRE CWA TO THE TWO DIFFERENT AREAS OVER THE SOUTHEAST
AND NORTHWEST. ALSO THE MODELS ARE ALSO INDICATING A COUPLE OF
DIFFERENT WAVES OF PRECIPITATION. ONE THIS EVENING WITH THIS
IN ITAL WAVE AND THEN ANOTHER ONE LATER TONIGHT. ALL IN ALL THERE
LOOKS TO BE SOME KIND OF PRECIPITATION MOVING ACROSS MOST OF THE
AREA...JUST NOT SURE EXACTLY WHERE.
.LONG TERM...(THURSDAY THROUGH WEDNESDAY)
ISSUED AT 228 PM MDT WED MAY 21 2014
THE FOCUS/MAIN CONCERNS FOR THE LONG TERM FORECAST PERIOD ARE SEVERE
WEATHER CHANCES AND POTENTIAL FOR HEAVY RAINS. THE PRIMARY TIME FOR
SEVERE WEATHER WITHIN THE LONG-TERM FORECAST RESIDES ON THURSDAY
AND THURSDAY NIGHT. THREAT FOR HEAVY RAINS WILL BE HIGHEST FROM
THURSDAY THROUGH SATURDAY NIGHT.
ON THURSDAY...A LULL IN CONVECTIVE ACTIVITY SEEMS PROBABLE FOR
THURSDAY MORNING BEFORE ACTIVITY ONCE AGAIN RAMPS UP IN THE
AFTERNOON. IN A SIMILAR SCENARIO TO WEDNESDAY...THUNDERSTORMS
DEVELOP TO THE SOUTH AND WEST ALONG A STALLED FRONT...CONVECTIVE
OUTFLOWS AND THE FRONT RANGE. THUNDERSTORMS THEN SPREAD NORTHEAST
ACROSS THE FORECAST AREA. INSTABILITY MAY BE HIGHER THURSDAY
COMPARED TO TODAY...HOWEVER...THE SHEAR SIGNIFICANTLY DECREASES. DO
NOT THINK THE TORNADO OR SUPERCELL THREAT IS AS HIGH FOR THURSDAY
COMPARED TO WEDNESDAY. PULSE-LIKE HAIL STORMS AND CONVECTIVE
CLUSTERS SHOULD BE THE PRIMARY STORM MODES WITH LARGE HAIL AND
DAMAGING WINDS AS THE MAIN THREAT. SOME SIGNIFICANT HAIL AT OR ABOVE
2 INCHES REMAINS POSSIBLE.
FROM THURSDAY NIGHT THROUGH MONDAY...SHOWER AND THUNDERSTORM CHANCES
CONTINUE ACROSS THE FORECAST AREA AS THE UPPER LEVEL LOW REMAINS
OVER THE WESTERN UNITED STATES. HAVE ADVERTISED THE BEST CHANCES FOR
RAIN IN THE AFTERNOON AND EVENING EACH DAY AS SHORTWAVE TROUGHS PASS
THROUGH AND DAYTIME INSTABILITY IS HIGHEST. IT IS POSSIBLE THAT
CONVECTION CONTINUES THROUGHOUT THE NIGHT ON THURSDAY AND POSSIBLY
FRIDAY. THE UPPER LEVEL LOW PRESSURE SYSTEM EJECTS OVER THE PLAINS
MONDAY AND CLEARS OUT TO THE EAST BY TUESDAY. MODELS HAVE SLOWED THE
SYSTEM SLIGHTLY SO HAVE PULLED POPS BACK TO THE WEST SOME.
WITH RESPECT TO POTENTIAL FLASH FLOODING...AGAIN THE HIGHEST
POTENTIAL FOR THIS THREAT IS BETWEEN THURSDAY NIGHT AND SATURDAY
NIGHT. PRECIPITABLE WATER READINGS APPROACH TO EXCEED 2 STANDARD
DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR. SEVERAL CLUSTERS WILL
PASS THROUGH WITH HEAVY RAIN RATES AND SUFFICIENT INSTABILITY. STILL
UNSURE ABOUT THIS BECOMING A WIDESPREAD FLOODING EVENT DUE TO
UNCERTAINTY IN EXACT STORM MOVEMENT. IF THERE WERE TO BE FLASH
FLOODING...THE MOST LIKELY LOCATION IS NORTHWEST KANSAS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1143 AM MDT WED MAY 21 2014
AT THIS TIME IT LOOKS LIKE THUNDERSTORMS WILL WILL NOT AFFECT
EITHER TAF SITE UNTIL THE EVENING HOURS AT THE EARLIEST. AT BOTH
SITES IT LOOKS LIKE CONDITIONS WILL STAY VFR WITH THE THUNDERSTORMS
UNLESS A STRONG TO SEVERE THUNDERSTORMS MOVES OVERHEAD WHICH COULD
LEAD TO MVFR CONDITIONS. THE BEST CHANCE FOR THIS LOOKS TO BE AT
KGLD BUT ALSO COULD BE STRATUS THAT DEVELOPS IN THE WAKE OF
WHATEVER THUNDERSTORM ACTIVITY HAS OCCURRED. THE MVFR CONDITIONS
LOOK TO OCCUR AT KGLD DURING THE LAST HALF OF THE PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
223 PM MDT WED MAY 21 2014
.SHORT TERM...(THIS AFTERNOON INTO TONIGHT)
ISSUED AT 205 PM MDT WED MAY 21 2014
MAIN CHANGE FOR THIS TIME PERIOD WAS TO SLOW THE ONSET OF
THUNDERSTORM DEVELOPMENT. FRONT WAS DRAPED RATHER FAR SOUTH AND
ALONG THE FRONT RANGE TO THE WEST. AN AREA OF SURFACE CONVERGENCE
EXTENDED FROM KIT CARSON AND CHEYENNE COUNTIES TOWARD THE
NORTHWEST. RATHER STRONG SURFACE WINDS OCCURRING OVER THE AREA AT
THIS TIME. SHORTWAVE TROUGH OVER NEW MEXICO IS EXPECTED TO MOVE
TOWARD THE NORTHEAST THROUGH THE NIGHT WITH A SLUG OF SUBTROPICAL
MOISTURE COMING IN ADVANCE OF IT. ALSO A RIGHT REAR QUADRANT OF
THE JET STARTS OVER THE SOUTHWEST HALF OF THE AREA LATE THIS
AFTERNOON INTO THE EVENING HOURS.
THIS IS ALL STARTING A LITTLE SLOWER THAN WHAT THE EARLIER FORECAST
HAD. AREA RADARS/SATELLITE/LIGHTNING DETECTION SHOW AN AREA/LINE
OF STORMS DEVELOPING FROM SOUTHWEST KANSAS INTO SOUTHEAST COLORADO
TO ALONG THE NORTHERN COLORADO FRONT RANGE. WHERE THE MAIN PROBLEM
IS FOR THIS FORECAST IS THAT THE MODELS DISAGREE ON WHERE TO PUT
THE MAIN SWATCH OF STORMS/QPF. SOME TAKE THE MAIN AREA OVER THE
NORTHWEST HALF...SOME OVER THE SOUTHEAST PORTION CLOSEST TO THE
FRONT AND SOME DO BOTH.
THE HRRR WHICH HAS BEEN DOING WELL RECENTLY HAS TRENDED FROM
TAKING A BROKEN SWATH OF PRECIPITATION FROM SOUTHWEST TO NORTHEAST
ACROSS THE ENTIRE CWA TO THE TWO DIFFERENT AREAS OVER THE SOUTHEAST
AND NORTHWEST. ALSO THE MODELS ARE ALSO INDICATING A COUPLE OF
DIFFERENT WAVES OF PRECIPITATION. ONE THIS EVENING WITH THIS
IN ITAL WAVE AND THEN ANOTHER ONE LATER TONIGHT. ALL IN ALL THERE
LOOKS TO BE SOME KIND OF PRECIPITATION MOVING ACROSS MOST OF THE
AREA...JUST NOT SURE EXACTLY WHERE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 337 AM MDT WED MAY 21 2014
MEDIUM RANGE MODEL CONSENSUS IS FOR THE SOUTHWEST CONUS CLOSED UPPER
LOW TO DRIFT EASTWARD TOWARD THE CENTRAL HIGH PLAINS REGION.
CONFIDENCE IN THIS SOLUTION IS ABOVE AVERAGE GIVEN RELATIVELY LITTLE
SPREAD IN THE DETERMINISTIC AND ENSEMBLE GUIDANCE...ALTHOUGH
RELATIVELY MINOR TIMING AND PLACEMENT DISCREPANCIES SHOW UP TOWARD
THE BEGINNING OF THE WEEK. CURRENT SOLUTION IS FOR THE UPPER LOW TO
PASS JUST SOUTH OF THE FORECAST AREA ACROSS SOUTHERN KANSAS LATE
MONDAY AND EARLY TUESDAY SHIFTING THE DEEP MOISTURE TO THE EAST.
UPPER LEVEL RIDGING WILL QUICKLY BUILD IN TOWARD THE MIDDLE OF THE
WEEK.
AHEAD OF THE UPPER LOW THE MEAN FLOW WILL BE MERIDIONAL WITH A
PERSISTENT BELT OF DEEP MOISTURE EXTENDING FROM THE WESTERN GULF
NORTHWARD INTO THE REGION. PWAT VALUES WILL BE CONSISTENTLY OVER ONE
INCH FOR MUCH OF THE PERIOD...ESPECIALLY ACROSS THE EAST. FORCING
FOR ASCENT FROM THE UPPER LOW...DEEP ANOMALOUS MOISTURE...AND STORM
MOTIONS AROUND 15 KNOTS OR LESS RAISE CONCERN FOR HEAVY RAINFALL
AMOUNTS. ADJUSTED QPF UPWARD SLIGHTLY TO BE MORE IN LINE WITH WPC
GUIDANCE. FLOODING CONCERNS AT THIS TIME ARE MINIMAL SINCE
CUMULATIVE AMOUNTS THAT MAY EXCEED TWO INCHES WILL OCCUR OVER THE
SPAN OF SEVERAL DAYS. THIS WILL NEED TO BE MONITORED...ESPECIALLY ON
A LOCALIZED BASIS IF TRAINING OF CONVECTIVE CELLS DEVELOPS.
COMPARED TO THE NEAR TERM...MID LEVEL LAPSE RATES ARE NOT AS STEEP
AND CAPE IS RELATIVELY SKINNY DURING THE EXTENDED PERIOD. THIS IS
TYPICAL OF SUCH A PATTERN WHICH SUPPORTS ANOMALOUS DEEP MOISTURE.
THIN CAPE AND WEAK SHEAR WILL LIMIT THE SEVERE POTENTIAL THROUGH THE
PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1143 AM MDT WED MAY 21 2014
AT THIS TIME IT LOOKS LIKE THUNDERSTORMS WILL WILL NOT AFFECT
EITHER TAF SITE UNTIL THE EVENING HOURS AT THE EARLIEST. AT BOTH
SITES IT LOOKS LIKE CONDITIONS WILL STAY VFR WITH THE THUNDERSTORMS
UNLESS A STRONG TO SEVERE THUNDERSTORMS MOVES OVERHEAD WHICH COULD
LEAD TO MVFR CONDITIONS. THE BEST CHANCE FOR THIS LOOKS TO BE AT
KGLD BUT ALSO COULD BE STRATUS THAT DEVELOPS IN THE WAKE OF
WHATEVER THUNDERSTORM ACTIVITY HAS OCCURRED. THE MVFR CONDITIONS
LOOK TO OCCUR AT KGLD DURING THE LAST HALF OF THE PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...RB
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1121 PM MDT TUE MAY 20 2014
.UPDATE...
ISSUED AT 1114 PM MDT TUE MAY 20 2014
SEVERE THREAT HAS ENDED FOR THIS EVENING IN THE LOCAL AREA WITH
BOUNDARY LAYER DECOUPLING AND INCREASING CIN. THUNDERSTORMS HAVE
RECENTLY REDEVELOPED JUST WEST OF THE AREA IN NORTHEAST COLORADO
ON NOSE OF A SOUTHERLY LLJ. HRRR HAS A GOOD HANDLE AND MOVES THAT
AREA NORTH INTO WYOMING AND THE NEBRASKA PANHANDLE...WHICH MATCHES
UP WELL WITH THE 310K ISENTROPIC FORECAST FROM THE NAM OF THE
POSITION OF THE LLJ THROUGH THE OVERNIGHT...SO WILL KEEP ONLY
SLIGHT CHANCE POPS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 219 PM MDT TUE MAY 20 2014
AIR MASS IS RATHER MOIST AND UNSTABLE BELOW 700 MB WITH LOW LEVEL
UPSLOPE IN PLACE BEHIND THE FRONT THAT IS TO OUR SOUTH. PROBLEM IS
THE LEVELS ABOVE ALL THIS. THERE IS LITTLE TO NO LIFT THROUGH JET
LEVEL AS HEIGHTS SLOWLY RISE THROUGH THE NIGHT. ALSO A RATHER
DEEP/VERY DRY EML IS ON TOP OF THE AREA. THIS IS BASICALLY SQUASHING
WHAT IS TRYING TO DEVELOP WHICH IS A RATHER WIDESPREAD FLAT CUMULUS
FIELD.
THE BEST LIFT...MOISTURE...INSTABILITY AND LEAST CAP IS OVER THE
FAR WEST AND NORTHWEST PORTION OF THE AREA THROUGH MID EVENING. SO
KEPT A SLIGHT CHANCE IN THIS AREA. BY 06Z...THE CAP STRENGTHENS
SIGNIFICANTLY AND EXPECT WHATEVER PRECIPITATION THAT WAS AROUND TO
BE DONE. WINDS SHOULD LIGHTEN UP THROUGH THE NIGHT AND IF CLOUD
COVER DECREASES ENOUGH...TEMPERATURES SHOULD HAVE NO PROBLEM WITH
READING DROPPING TO NEAR THE COOLER GUIDANCE.
AS HAS BEEN ADVERTISED THE LAST FEW DAYS...THE FIRST IN A SERIES
OF ACTIVE WEATHER DAYS WILL START ON WEDNESDAY. MOISTURE...LIFT
AND INSTABILITY INCREASE SUBSTANTIALLY OVER WHAT IS AROUND RIGHT
NOW. CONSIDERING THE STRONGER LIFT...LARGE INSTABILITY...AND SIGNIFICANT
SHEAR...SEVERE THUNDERSTORMS LOOK TO BE A GOOD BET WITH ALL THREATS
POSSIBLE. THUNDERSTORMS BEGIN BY MID AFTERNOON. CONTINUED THE
MENTION OF SEVERE THUNDERSTORMS IN THE FORECAST. MODELS ARE ALL
OVER THE PLACE WITH THE THERMAL FIELD. TENDED TO BLEND THE
GUIDANCE WITH A HEDGE TOWARD THE COOLER SIDE CONSIDERING THE THE
EXPECTED INCREASE IN CLOUD COVER AND UPSLOPE COMPONENT OF THE
WIND.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 320 PM MDT TUE MAY 20 2014
THE FOCUS/MAIN CONCERNS FOR THE LONG TERM FORECAST PERIOD ARE SEVERE
WEATHER CHANCES AND POTENTIAL FOR HEAVY RAINS. UPPER LEVEL PATTERN
WILL REMAIN FAVORABLE FOR SEVERE WEATHER WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT. WITH THE HEIGHTENED MOISTURE CONTENT OF THE
AIR...THE POTENTIAL EXISTS FOR SOME HEAVY RAINS AND FLASH FLOODING
FROM THURSDAY THROUGH SUNDAY.
SEVERE THUNDERSTORMS WILL CONTINUE INTO THE EVENING HOURS ON
WEDNESDAY. ATMOSPHERE AND WIND PROFILES BECOME MORE FAVORABLE FOR A
FEW TORNADOES DURING THE EARLY EVENING HOURS. WIND SHEAR AND HELICITY
HAVE COME DOWN SOME FROM THE MODEL RUNS YESTERDAY SO AM NOW MORE
PESSIMISTIC ABOUT THE PROBABILITY OF A STRONG TORNADO. CAN NOT RULE
OUT A STRONG TORNADO COMPLETELY WITH THE HIGH AMOUNT OF INSTABILITY
BUT SHEAR AND HELICITY DO NOT LOOK FAVORABLE FOR AN OUTBREAK OF
STRONG TORNADOES. LARGE HAIL...UP TO THE SIZE OF BASEBALLS...AND
DAMAGING WINDS REMAIN POSSIBLE THROUGH THE EVENING AS WELL BEFORE
STORMS CONGEAL INTO SMALL CLUSTERS AND FADE IN INTENSITY.
ON THURSDAY...ANOTHER ROUND OF SEVERE THUNDERSTORMS IS EXPECTED.
THIS IS A SIMILAR SETUP TO WEDNESDAY WITH A STALLED FRONT LINGERING
ALONG HIGHWAY 96 IN EASTERN COLORADO AND WESTERN KANSAS. FOR THIS
DAY...CONVECTION LOOKS TO BE MORE WIDESPREAD. INSTABILITY HAS
INCREASED FROM YESTERDAYS MODEL RUNS FOR THURSDAY WITH SBCAPE OF
2000-3500 J/KG. LARGE HAIL...POSSIBLY SIGNIFICANT WITH HAIL TO THE
SIZE OF BASEBALLS...AND DAMAGING WINDS WOULD BE THE PRIMARY THREATS.
A FEW TORNADOES ARE POSSIBLE FOR THURSDAY AS WELL...HOWEVER...WIND
SHEAR AND HELICITY DECREASE FOR THURSDAY AS THE WIND FIELD ALOFT
WEAKENS. WITH WIDESPREAD CONVECTION EXPECTED AND CONVECTION LIKELY
ON WEDNESDAY...THINK THE THREAT OF FLASH FLOODING INCREASES THURSDAY
FOR LOCATIONS WHERE STORMS ARE ABLE TO TRAIN OR WHERE GROUND HAS
BEEN SATURATED FROM WEDNESDAYS CONVECTION. OVERALL...THE FORECAST
CONFIDENCE FOR THURSDAY IS SOMEWHAT LOW DUE TO CONCERNS OVER THE
EVOLUTION OF CONVECTION WEDNESDAY. MODELS SEEM CONFIDENT THE
ATMOSPHERE WILL RECHARGE TO THE SOUTH ALONG THE FRONT SO WILL GO
WITH THIS MODE OF THINKING FOR NOW. THUNDERSTORM OUTFLOWS...AIR
STABILIZED BY WEDNESDAY NIGHTS CONVECTION AND POSSIBLE DAYTIME
STRATUS ARE MAJOR CONCERNS FOR THURSDAY.
FROM FRIDAY THROUGH SUNDAY...SHORTWAVE TROUGHS SWING AROUND THE
STATIONARY UPPER LEVEL LOW...CONTINUING THE CHANCES FOR SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING. PRECIPITABLE WATER ANOMALIES
APPROACH 2 STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR
THROUGH THE WEEKEND. INCREASED QPF FORECAST AND MAINTAINED MENTION
OF LOCALLY HEAVY RAIN/FLASH FLOODING. THIS WILL LIKELY NOT BECOME A
WIDESPREAD FLOODING EVENT BUT LOCAL PROBLEMS ARE POSSIBLE WHERE
SOILS BECOME SATURATED AND STORMS TRAIN.
THE UPPER LEVEL LOW FINALLY EJECTS ACROSS THE HIGH PLAINS MONDAY
WITH DRYING CONDITIONS TOWARDS THE MIDDLE OF NEXT WEEK. MONDAY
SHOULD BE THE LAST PRECIPITATION CHANCE AS SHORTWAVE RIDGING BUILDS
IN BEHIND THE LOW. WARMER TEMPERATURES...INTO THE MID 80S...RETURN
TUESDAY UNDER CLEARING SKIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1114 PM MDT TUE MAY 20 2014
VFR EXPECTED THROUGH THE OVERNIGHT WITH ONLY A SLIGHT CHANCE FOR
AN ISOLATED SHOWER OR THUNDERSTORM. NEXT PRECIPITATION CHANCES
WILL COME WEDNESDAY AFTERNOON WITH STORMS REDEVELOPING SOUTH OF
INTERSTATE 70 NEAR A STATIONARY FRONT THEN MOVING NORTH IN THE
LATE AFTERNOON AND EVENING HOURS. SOME STORMS MAY BE SEVERE WITH
LARGE HAIL AND DAMAGING WINDS ON WEDNESDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...024
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...024
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1208 AM CDT Wed May 21 2014
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Wednesday)
Issued at 314 PM CDT TUE MAY 20 2014
The forecast seems to be unfolding as expected with the latest NAM
forecast soundings showing a capping inversion holding strong over
the area through the afternoon. 19Z water vapor imagery shows a
closed low over central CA with southwesterly flow aloft. There does
not appear to be much in the way of large scale forcing within the
upper flow, and low level convergence along an inverted surface
trough appears to be marginal with not much of a CU field in the
warm sector. The HRRR does try to bring convection off the higher
terrain to the west, but again shows it weakening due to the
elevated mixed layer before it reaches central KS. So expect a dry
forecast heading into Wednesday. Have trended lows tonight a couple
degrees cooler across northern KS. With the trough axis forecast to
pivot more west to east across the forecast area, winds are likely
to become light. This combined with mostly clear skies should allow
for some decent radiational cooling and lows in the lower 60s across
the northern counties. East central KS is likely to stay south of
the trough axis in the warmer air with higher dewpoints so have kept
lows in the mid to upper 60s.
For Wednesday, models are in agreement that the weak boundary will
be across the area with good moisture pooling along it. The NAM and
GFS warm the boundary layer enough so that CAPE values increase to
3000 or 3500 J/kg. They also cool mid levels some so that there is
very little or no CIN by the mid afternoon. Large scale forcing
continues to look unimpressive, but there could be enough
convergence along the boundary for some isolated storms to develop
by the late afternoon. Deep layer shear of 40 to 50 KTS also suggest
that if storms are able to form, they could become supercellular. At
this point low level shear parameters show little or no chance for
tornadoes so main risks with storms that form would be a hail and
wind. Highs Wednesday should not be quite as warm as models weaken
the thermal ridge over the area. Because of this highs are forecast
to be in the middle and upper 80s.
.LONG TERM...(Wednesday Night through Tuesday)
Issued at 314 PM CDT TUE MAY 20 2014
Somewhat above normal thunderstorm chances continue to dominate the
middle and later portions of the forecast. Have shaded chances
slightly up and down when some confidence exists in possible
evolution, but overall confidence on timing and placement of precip
not high.
Wednesday night into Thursday night still present the more dynamic
storm periods with the stationary front keeping some minor
baroclinicity. Any local afternoon storms could easily persist in
the evening hours and keep at least modest severe weather potential,
but highest coverage for overnight Wednesday night into early
Thursday still at least moderately dependent on where convection can
be the most robust and organized to the west. Models differ on
where this will be, but some indications this could be a bit farther
south than earlier anticipated. A rather warm and moist boundary
layer should keep low-level parcels rather buoyant and NAM and GFS
agree with limited CIN through Wednesday night for at least some
severe potential. Synoptic surface high to the northeast and low the
southwest should keep at lest some low-level convergence intact for
Thursday afternoon over the area as long as overnight and early day
convection does not displace the effective front elsewhere. Corfidi
vectors turn more southeast and again may be rather parallel to the
front for overnight convection to again pass through. By Friday
afternoon, more meridional low level flow takes hold for the Central
Plains and should greatly reduce convergence, again barring
MCS-dominated surface features. GFS and ECMWF are rather consistent
with an upper wave emerging from the old trough, but this appears to
be at least partially due to previous convection. Despite weakening
mid-level lapse rates, instability should continue to be at least
modest with good moisture through the column for some storm chances
into Sunday. Better dynamic forcing aloft could commence Sunday
night into Tuesday afternoon if the GFS and ECMWF are correct with
the low finally pushing through, but of course timing ejection of
cut-off lows is difficult at best. Little change in temperatures is
forecast, but again highs will be greatly impacted by any persistent
MCS that persists.
&&
.AVIATION...(For the 06Z TAFs through 06Z Wednesday Night)
Issued at 1207 AM CDT WED MAY 21 2014
VFR conditions expected through the period. Thunderstorm chances
increase tomorrow afternoon around 21z with another more
widespread round possible after this issuance in the late evening
early morning hours. 67
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...65
AVIATION...67
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
909 PM EDT THU MAY 22 2014
.UPDATE...
ISSUED AT 840 PM EDT THU MAY 22 2014
A COLD FRONT CONTINUES TO SAG SOUTH ACROSS THE REGION AND IS EXITING
INTO VA AND TN. CONVECTION HAS ALSO MOVED WELL SOUTH OF THE AREA OVER
PARTS OF NORTHEAST TN AND THE SMOKEY MOUNTAINS. DRIER AIR IS BEGINNING
TO FILTER IN FROM THE NORTHWEST WITH DEWPOINTS ALREADY IN THE MID 50S
ACROSS THE FAR NORTH. A FEW OBSERVATIONS OF FOG HAVE BEEN NOTED NEAR
WHERE HEAVIER RAIN OCCURRED EARLIER THIS EVENING...AT EKQ AND I35.
ADDITIONAL FOG DEVELOPMENT SHOULD OCCUR INTO THE OVERNIGHT HOURS AS
DRIER AIR WILL BE SLOWER TO FILTER INTO CENTRAL AND SOUTHERN PORTIONS
OF THE CWA. HOURLY GRIDS HAVE BEEN ADJUSTED ACCORDINGLY.
UPDATE ISSUED AT 635 PM EDT THU MAY 22 2014
WITH THE WORST OF THE STORMS SINKING SOUTH OUT OF EAST KENTUCKY HAVE
GONE AHEAD AND DROPPED THE SEVERE WATCH FOR WAYNE AND MCCREARY
COUNTIES. ALSO TAPERED OFF THE THUNDERSTORM CHANCES THROUGH THE REST
OF THE EVENING AND ADDED SOME PATCHY DENSE FOG TO THE VALLEYS LATE
TONIGHT. FINALLY...TWEAKED THE NEAR TERM GRIDS PER THE LATEST OBS AND
TRENDS. THESE GRID UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS
ALONG WITH THE DISSEMINATION OF THE ZFP AND WCN. AN UPDATED HWO IS IN
THE QUEUE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 415 PM EDT THU MAY 22 2014
19Z SFC ANALYSIS SHOWS LOW PRESSURE CENTERED OVER THE POCONOS WITH A
COLD FRONT STRETCHED SOUTHWEST AND BISECTING KENTUCKY. SOUTH OF THIS
FRONT DEWPOINTS ARE IN THE MID AND UPPER 60S WITH TEMPERATURES IN THE
MID 80S. CONDITIONS ARE JUST A BIT DRIER AND COOLER TO THE NORTHWEST
OF IT. TO THE SOUTH OF THE FRONT...INSTABILITY IS QUITE HIGH WITH
LIS IN THE -8 TO -10 DEGREE RANGE WITH CAPE TO 3500 J/KG OVER THE
WESTERN PORTION OF THE STATE. ON SATELLITE...THE CU IS DOING BEST
OVER SOUTHERN KENTUCKY...WHILE ON RADAR SOME RETURNS ARE FINALLY
SHOWING UP TO THE NORTHWEST OF BOWLING GREEN. EXPECT THESE TO DEVELOP
AND STRENGTHEN RAPIDLY WITH A GENERAL MOVEMENT TO THE EAST SOUTHEAST.
SPC HAS HIGHLIGHTED THIS AREA THROUGH SOUTHERN PARTS OF EAST KENTUCKY
FOR A POTENTIAL WATCH BOX. MEANWHILE...WINDS ARE MAINLY FROM THE WEST
AT 10 TO 20 KTS ACROSS EAST KENTUCKY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE FAST NORTHWEST FLOW
THROUGH NORTHEAST KENTUCKY BETWEEN A RETREATING RIDGE TO THE SOUTH
AND EXPANDING TROUGHING TO THE NORTH. A WEAK PATCH OF ENERGY WILL
PASS THROUGH THIS NORTHWEST FLOW KNOCKING DOWN HEIGHTS LOCALLY INTO
THE EVENING. THE RIDGE IS FURTHER SUPPRESSED ON FRIDAY IN RESPONSE TO
THE NORTHEAST TROUGH DIGGING THROUGH THE CENTRAL APPALACHIANS. ONCE
THIS TROUGH AND SHARP SHORTWAVE MOVES OUT OF THE AREA...HEIGHTS WILL
REBOUND OVER EAST KENTUCKY INTO SATURDAY MORNING. WITH THE GOOD MODEL
AGREEMENT WILL FOLLOW THE DETAILS FROM THE NAM12 AND THE LAST FEW
RUNS OF THE HRRR MOST PROMINENTLY.
SENSIBLE WEATHER WILL FEATURE SCATTERED STORMS OVER THE SOUTHERN
HALF OF THE CWA THIS EVENING...POTENTIALLY SEVERE ALONG THE TENNESSEE
BORDER. A WATCH BOX IS NOW OUT WITH WAYNE AND MCCREARY INCLUDED...AND
JUST IN TIME AS THE STORMS ARE QUICKLY DEVELOPING OVER OUR SOUTHERN
TIER. EXPECT THESE TO FADE OUT BY MIDNIGHT WITH SOME CLEARING HELPING
TO BUILD FOG THROUGH THE VALLEYS ACROSS EAST KENTUCKY. THE FOG COULD
BECOME LOCALLY DENSE IN THE DEEPEST VALLEYS. THE FRONT DRIFTS TO THE
SOUTH OF THE AREA ON FRIDAY TAKING THE THREAT OF SHOWERS AND
THUNDERSTORMS WITH IT. THIS SHOULD MAKE FOR A PLEASANT END TO THE
WORK WEEK WITH TEMPERATURES ABOUT 5 TO 10 DEGREES COOLER THAN TODAY.
LATER FRIDAY NIGHT...ANTICIPATE A DECENT RIDGE TO VALLEY TEMPERATURE
SPLIT GIVEN MOSTLY CLEAR SKIES AND HIGH PRESSURE MOVING BY TO THE
NORTH. SOME PATCHY VALLEY FOG CAN ALSO BE EXPECTED TO DEVELOP
TOWARDS DAWN SATURDAY.
USED THE BCCONSSHORT GRIDS AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS WITH THE BCCONSALL
ADDED TO THE END OF THE SHORT TERM THEREAFTER. MOST ADJUSTMENTS
WHERE MADE TO ACCOUNT FOR TERRAIN DIFFERENCES TONIGHT AND FRIDAY
NIGHT IN THE LOWS. AS FOR POPS...ENDED UP ON THE HIGH SIDE OF ALL
GUIDANCE TONIGHT AND THEN SINGLE DIGITS THROUGH THE REST OF THE
PERIOD...IN LINE WITH THE MOS NUMBERS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 PM EDT THU MAY 22 2014
CONDITIONS WILL STAY FAIRLY CONSTANT IN THE UPPER LEVELS DURING THE
EXTENDED...WITH THE MODELS IN FAIRLY GOOD AGREEMENT THROUGH DAY 7.
SATURDAY 12Z WILL START OFF THE PERIOD WITH AN UPPER LEVEL RIDGE
MOVING FROM THE CENTRAL PLAINS ACROSS EASTERN KY. THIS RIDGE WILL
REMAIN THE DRIVING FORCE THROUGH TUESDAY. FOR THE MID TERM SECTION
OF THE FORECAST PERIOD...ANY MOISTURE WILL REMAIN TO THE WEST OF THE
RIDGE...KEEPING MUCH OF KY BOTH DRY AND IN A SOUTHERLY WIND PATTERN.
THIS WILL ALLOW TEMPERATURES TO BOOST TO WELL ABOVE NORMAL THROUGH
EARLY NEXT WEEK. SATURDAY IS STILL EXPECTED TO BE THE COOLEST DAY AS
HIGH PRESSURE AND UPPER LEVEL RIDGING ARE JUST BEGINNING TO TAKE
CONTROL...WITH HIGHS NEAR CLIMATOLOGICAL NORMAL FOR THIS TIME OF
YEAR. TEMPERATURES SATURDAY NIGHT WILL SHOW A DECENT DIURNAL RANGE
WITH A THERMAL BELT SETTING UP AROUND THE RIDGES. THEN AS SOUTHERLY
FLOW TAKES CONTROL...TEMPS WILL BEGIN TO RISE INTO THE MID AND EVEN
SOME UPPER 80S BY TUESDAY OF NEXT WEEK.
MODELS ARE SHOWING SOME VARIATION IN SOME ISOLATED TO SCATTERED
AFTERNOON SHOWERS/TSTORMS FOR MONDAY AND TUESDAY
AFTERNOON...ALTHOUGH NO PARTICULAR MODEL IS GOING TO HAVE A GOOD
HANDLE WHERE THEY WILL SET UP EXACTLY. THERE IS ENOUGH EVIDENCE TO
WARRANT ISOLATED CHANCES ON MONDAY...AND SCATTERED CHANCES ACROSS
EASTERN KY FOR TUESDAY. BY TUESDAY EVENING...LOW PRESSURE OVER THE
SOUTH CENTRAL PLAINS WILL HAVE SHIFTED EASTWARD SLIGHTLY AND WILL BE
ENTERING INTO THE MISSISSIPPI RIVER VALLEY. THIS WILL CREATE MORE
LIFT AND MOISTURE INFLUX...AS WELL AS CONTINUED WARM UNSTABLE
AIR...ALLOWING THE CHANCE OF SHOWERS AND THUNDERSTORMS TO CONTINUE
TUESDAY NIGHT INTO THURSDAY TO ROUND OUT OUR FORECAST PERIOD. STUCK
PRETTY CLOSE TO THE ALLBLEND FOR THE EXTENDED POPS DUE TO THE
UNCERTAINTY IN CONVECTION THIS FAR OUT IN THE FORECAST PERIOD.
SMOOTHED OUT ANY MAJOR BULLSEYES OF POPS AND LOWERED SOME OF THE
HIGHER END CHANCES THAT ARE HARD TO WARRANT THIS FAR OUT.
OTHERWISE...WE ARE MATCHING UP QUITE WELL WITH SURROUNDING OFFICES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 840 PM EDT THU MAY 22 2014
THE GROUND MOISTURE LEFT BEHIND FROM THE RECENT STORMS WILL LIKELY
BE ENOUGH FOR AREAS OF FOG...LOCALLY DENSE IN SOME OF THE DEEPER
VALLEYS...AND PROBABLY BELOW AIRPORT MINS AT SME AND LOZ...AS SKIES
GO AT LEAST PARTIALLY CLEAR TONIGHT. THE FOG WILL LIFT AND DISSIPATED
BY 14Z TO 15Z...WITH DIURNALLY DRIVEN CU LIKELY STAYING IN THE VFR
RANGE AROUND 4KFT. WINDS WILL GENERALLY BE LIGHT THROUGH THE PERIOD
OUT OF THE WEST OR NORTHWEST AT 10KT OR LESS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
655 PM EDT WED MAY 21 2014
.UPDATE...
ISSUED AT 655 PM EDT WED MAY 21 2014
NOW THAT WE ARE UNDER A SEVERE THUNDERSTORM WATCH BOX UNTIL 2 AM EDT
HAVE UPDATED ALL THE GRIDS THROUGH THE NIGHT TO REFLECT THE SEVERE
THREATS AND TIME THE STORM CLUSTERS AS FORECASTED BY THE HRRR. DID
TEMPER THE PROGNOSIS FROM THAT MODEL WITH THE EXISTING GRIDS AND
ALSO THE 18Z NAM12. IT DOES LOOK LIKE COLD POOLS ARE DEVELOPING WITH
THE CURRENT CLUSTERS TO THE NORTH AND THIS SHOULD HELP DRIVE STRONG
TO SEVERE STORMS SOUTH INTO OUR CWA QUICKER. HAVE TIMED THE STORMS
INTO THE JACKSON AREA AROUND 9 PM WITH THEM ARRIVING AN HOUR OR SO ON
EITHER SIDE OF THAT TIME NORTHWEST AND SOUTHEAST OF THE OFFICE. KEPT
IN THE HEAVY RAIN POTENTIAL AND THE HRRR IS NOW SHOWING BETTER
TRAINING POTENTIAL FOR OUR WESTERN COUNTIES THROUGH THE NIGHT. LARGE
HAIL AND GUSTY WINDS ARE STILL THE MAIN THREATS...THOUGH. DO EXPECT
THE SEVERE MODE TO TRANSITION TO A MAINLY DAMAGING WINDS ONE OVER THE
NEXT FEW HOURS. THESE GRID UPDATES AND THE NEW WCN/ZFP/HWO HAVE BEEN
ISSUED.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 350 PM EDT WED MAY 21 2014
18Z SFC ANALYSIS SHOWS LOW PRESSURE OVER THE GREAT LAKES WITH A COLD
FRONT EXTENDING SOUTHWEST THROUGH THE NORTHWEST OHIO VALLEY AND INTO
THE MIDDLE OF MISSOURI. SOUTHEAST OF THIS...PLENTY OF FUEL IS
BUILDING FOR CONVECTION IN THE FORM OF DEWPOINTS IN THE LOW TO MID
60S AND TEMPERATURES PUSHING 80 DEGREES. THIS HAS HELPED TO PRIME
EAST KENTUCKY FOR CONVECTION LATER IN THE EVENING AND THROUGH THE
NIGHT. A FEW ROGUE SHOWERS ARE POPPING UP AND DRIFTING EAST THROUGH
THE AREA THIS AFTERNOON...BUT THE MAIN SHOW LATER THIS EVENING WILL
BE ASSOCIATED WITH THE ONGOING STORMS IN OHIO AND INDIANA EITHER
DIRECTLY OR AS A RE-SPAWNED CLUSTER ON AN OUTFLOW BOUNDARY. ON
SATELLITE...THE HIGHER DEBRIS CLOUDS ARE STARTING TO CLEAR FROM THE
EARLIER CONVECTION TO THE NORTH. THIS SHOULD HELP GIVE A FINAL PUSH
TO THE INSTABILITY OVER THE NEXT SEVERAL HOURS...THOUGH LOWER CLOUDS
WILL REMAIN DUE TO THIS HUMID ENVIRONMENT. MEANWHILE...WINDS ARE FROM
THE SOUTHWEST TO WEST AT 10 TO 20 MPH WITH SOME GUSTS TO 25 MPH.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH RIDGING RETREATING TO THE
SOUTH TONIGHT IN THE FACE OF A DECENTLY STRONG SHORTWAVE MOVING
THROUGH FAST NORTHWEST FLOW...CROSSING NORTHERN KENTUCKY. THIS FLOW
PATTERN REMAINS IN PLACE INTO THE DAY THURSDAY WITH JUST A SLIGHT
SHIFT TO THE SOUTHWEST WITH THE MID LEVEL ENERGY TRACK. HEIGHT FALLS
WILL ACCOMPANY THIS ADJUSTMENT THROUGH EAST KENTUCKY INTO FRIDAY
MORNING IN CONJUNCTION WITH A SHARPER TROUGH SWEEPING SOUTHEAST
THROUGH THE EASTERN GREAT LAKES. WITH THIS AGREEMENT HAVE MAINLY
FOLLOWED THE GENERAL DETAILS FROM THE CURRENT AND PAST FEW RUNS OF
THE HRRR ALONG WITH SOME NAM12 INFLUENCE.
SENSIBLE WEATHER WILL FEATURE A LIKELY STORMY NIGHT ACROSS THE AREA.
THE HEIGHT FALLS...ENERGY PERTURBANCES AT MID LEVELS...AND A SPEED
MAX AT 500MB KEEPS THE STAGE SET FOR CONVECTIVE REDEVELOPMENT THROUGH
THE NIGHT INTO THURSDAY. INCREASING PWS...TOWARD 1.5 INCHES...THROUGH
THE AREA WILL CONTRIBUTE TO A POTENTIAL FOR HEAVY TO EXCESSIVE
AMOUNTS OF RAIN TONIGHT....ESPECIALLY IF SOLID COLD POOLS DEVELOP
ALONG WITH TRAINING OF CELLS. HOWEVER...CONFIDENCE IN ANY EXACT
SCENARIO REMAINS LOW GIVEN THE DEVELOPING CONVECTION PATTERN AND THE
CHALLENGE OF PREDICTING SUBSEQUENT INITIATION OFF OF THE SOUTHWARD
MOVING OUTFLOW BOUNDARIES. A LACK OF A CAP AND LIS TO -6/CAPES TO
2000 J/KG WILL ALSO MEAN A GOOD POTENTIAL FOR SEVERE WEATHER WITH ANY
ORGANIZED STORMS THIS EVENING AND INTO THE OVERNIGHT...SHOULD PRIOR
CONVECTION NOT STABILIZE THE ENVIRONMENT. HAVE HIT THIS POTENTIAL
HARD IN THE GRIDS...ZONES...AND HWO. AFTER A MILD NIGHT...A BOUNDARY
SHOULD BE LAYING FROM NORTHWEST TO SOUTHEAST ACROSS EAST KENTUCKY
WITH STILL A POTENTIAL FOR STRONG STORMS ACROSS SOUTHWESTERN PARTS
OF THE AREA. HAVE CONTINUED THIS THREAT INTO THE AFTERNOON. THE
BOUNDARY SHOULD WEAKEN AND DRIFT FURTHER SOUTHEAST INTO THE NIGHT
WITH LESS OF A RISK FOR CONVECTION. COOLER TEMPS WILL BE FOUND
THURSDAY NIGHT OVER OUR NORTHEAST WITH MILDER AND MUGGIER CONDITIONS
SOUTHWEST.
USED THE BCCONSSHORT GRIDS AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN TACKED ON
THE BCCONSALL. MOST ADJUSTMENTS WHERE MADE FOR TERRAIN DIFFERENCES
TONIGHT AND THURSDAY NIGHT. AS FOR POPS...ENDED UP ON THE HIGH SIDE
OF ALL GUIDANCE...BUT CLOSEST TO THE HIGHER MET NUMBERS TONIGHT AND
THURSDAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 300 PM EDT WED MAY 21 2014
EXTENDED MODELS ARE IN REASONABLE AGREEMENT THROUGH THE PERIOD...BUT
AS USUAL THERE IS BETTER AGREEMENT WITH LARGE SCALE FEATURES THAN
WITH DETAILS. WE START WITH AN UPPER LEVEL DISTURBANCE THAT DROPS
SOUTHEAST THROUGH THE REGION FRIDAY...EFFECTIVELY JUMP STARING A
TEMPORARILY STALLED OUT SFC COLD FRONTAL BOUNDARY AND SWEEPING IT
OUT OF OUR AREA. THEREAFTER UPPER LEVEL RIDGING AND SFC HIGH
PRESSURE WILL BUILD OVER OUR AREA AND PROVIDE US WITH VERY PLEASANT
WEATHER FOR THE UPCOMING WEEKEND.
MODELS DIFFER MORE WITH RETURN FLOW REGIME EARLY NEXT WEEK. WARM
FRONTAL ZONE WILL MOVE BACK TO THE NORTH ACROSS THE AREA MONDAY AND
COULD PROVIDE SOME PRECIPITATION TO EASTERN KENTUCKY. THEREAFTER WE
FIND OURSELVES IN THE WARM SECTOR AND MORE SUMMER LIKE WEATHER UNTIL
THE POTENTIAL ARRIVAL OF A LOW PRESSURE SYSTEM THAT WILL SLOWLY
MEANDER ITS WAY OUT OF THE CENTRAL PLAINS. 0Z ECMWF WANTS TO BRING
THIS SLOW MOVING DISTURBANCE INTO THE HEART OF THE OHIO VALLEY BY
LATE THURSDAY INTO FRIDAY...JUST BEYOND THE FORECAST WINDOW. A MUCH
MORE INCONSISTENT GFS...AND MORE SPECIFICALLY THE 12Z RUN WANTS TO
TAKE THE DISTURBANCE TO THE GULF COAST...WHILE DEVELOPING A MUCH
STRONGER SYSTEM OVER THE OHIO VALLEY FROM ENERGY DROPPING OUT OF
CANADA DURING THAT SME TIME FRAME. PAST RUNS OF THE ECMWF HAVE SHOWN
A TENDENCY TO TAKE THE DISTURBANCE TO THE GULF COAST AS WELL...BUT
HAS NOT SHOWN ANY EVIDENCE OF SUCH A STRONG SYSTEM DROPPING OUT OF
CANADA.
FOR SENSIBLE WEATHER...ATMOSPHERE STABILIZES RAPIDLY EARLY FRIDAY
MORNING. SO ANY SHOWERS THAT MIGHT LINGER ACROSS THE AREA THURSDAY
NIGHT WILL COME TO AN END JUST AS QUICKLY EARLY FRIDAY MORNING. HIGH
PRESSURE AND A PLEASANTLY COOL AIR MASS OVER THE AREA WILL PROVIDE
GREAT WEATHER FOR THE WEEKEND. WEATHER WILL TURN MUGGY AND RELATIVELY
HOT EARLY NEXT WEEK AFTER A WARM FRONT PUNCHES ITS WAY ACROSS OUR
AREA TO THE NORTH. FOR NOW IT APPEARS THE THREAT OF SHOWERS AND
THUNDERSTORMS WILL INCREASE DAILY THROUGH THE REMAINDER OF THE
WEEK...BUT MUCH WILL DEPEND ON THE PATTERN THAT SETS UP AT THE END
OF THE FORECAST WINDOW AND BEYOND. THE ECMWF AND GFS BOTH ADVERTISE
UNSETTLED WEATHER OVER OUR AREA BY THE END OF THE WEEK BUT VIA
DIFFERENT MEANS TO THAT END. AT THIS POINT AND AFTER CONSIDERING THE
TIME OF YEAR THOUGHTS ARE THAT ANYTHING IS POSSIBLE BEYOND TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 220 PM EDT WED MAY 21 2014
CONDITIONS ARE CURRENTLY VFR THROUGH THE AREA...BUT CIGS ARE NEAR
MVFR IN THIS HUMID ENVIRONMENT. CONVECTION IS EXPECTED LATER THIS
EVENING THROUGH THE ENTIRE FORECAST AREA WITH A POTENTIAL FOR
ORGANIZED AND UPSCALE DEVELOPMENT. INITIALLY...HAVE TIMED A
CONVECTIVE EVENT THROUGH THE TAF SITES DURING THE MID EVENING BASED
ON THE LATEST HRRR. HAVE LEFT VCTS IN THE TAFS FOR THE REST OF
THE NIGHT DUE TO A CONTINUED POTENTIAL FOR REDEVELOPMENT ALONG WITH
MVFR CIGS. THERE WILL LIKELY BE A LULL AND BETTER CONDITIONS FOR A
TIME EARLY IN THE MORNING OF THURSDAY...BUT FOR NOW WILL LEAVE THE
VCTS AND LOWER CIGS PREVAILING. WINDS WILL BE BREEZY FROM THE WEST
SOUTHWEST THROUGH THE EVENING WITH GUSTS TO 20 AND 25 KTS...BUT
CLOSER TO 35 KTS...OR HIGHER...WITH ANY STORMS THIS EVENING. WEST
WINDS OF 10 TO 20 KTS FOLLOW THROUGH THE REMAINDER OF THE TAF PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...RAY
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
350 PM EDT WED MAY 21 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 350 PM EDT WED MAY 21 2014
18Z SFC ANALYSIS SHOWS LOW PRESSURE OVER THE GREAT LAKES WITH A COLD
FRONT EXTENDING SOUTHWEST THROUGH THE NORTHWEST OHIO VALLEY AND INTO
THE MIDDLE OF MISSOURI. SOUTHEAST OF THIS...PLENTY OF FUEL IS
BUILDING FOR CONVECTION IN THE FORM OF DEWPOINTS IN THE LOW TO MID
60S AND TEMPERATURES PUSHING 80 DEGREES. THIS HAS HELPED TO PRIME
EAST KENTUCKY FOR CONVECTION LATER IN THE EVENING AND THROUGH THE
NIGHT. A FEW ROGUE SHOWERS ARE POPPING UP AND DRIFTING EAST THROUGH
THE AREA THIS AFTERNOON...BUT THE MAIN SHOW LATER THIS EVENING WILL
BE ASSOCIATED WITH THE ONGOING STORMS IN OHIO AND INDIANA EITHER
DIRECTLY OR AS A RE-SPAWNED CLUSTER ON AN OUTFLOW BOUNDARY. ON
SATELLITE...THE HIGHER DEBRIS CLOUDS ARE STARTING TO CLEAR FROM THE
EARLIER CONVECTION TO THE NORTH. THIS SHOULD HELP GIVE A FINAL PUSH
TO THE INSTABILITY OVER THE NEXT SEVERAL HOURS...THOUGH LOWER CLOUDS
WILL REMAIN DUE TO THIS HUMID ENVIRONMENT. MEANWHILE...WINDS ARE FROM
THE SOUTHWEST TO WEST AT 10 TO 20 MPH WITH SOME GUSTS TO 25 MPH.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH RIDGING RETREATING TO THE
SOUTH TONIGHT IN THE FACE OF A DECENTLY STRONG SHORTWAVE MOVING
THROUGH FAST NORTHWEST FLOW...CROSSING NORTHERN KENTUCKY. THIS FLOW
PATTERN REMAINS IN PLACE INTO THE DAY THURSDAY WITH JUST A SLIGHT
SHIFT TO THE SOUTHWEST WITH THE MID LEVEL ENERGY TRACK. HEIGHT FALLS
WILL ACCOMPANY THIS ADJUSTMENT THROUGH EAST KENTUCKY INTO FRIDAY
MORNING IN CONJUNCTION WITH A SHARPER TROUGH SWEEPING SOUTHEAST
THROUGH THE EASTERN GREAT LAKES. WITH THIS AGREEMENT HAVE MAINLY
FOLLOWED THE GENERAL DETAILS FROM THE CURRENT AND PAST FEW RUNS OF
THE HRRR ALONG WITH SOME NAM12 INFLUENCE.
SENSIBLE WEATHER WILL FEATURE A LIKELY STORMY NIGHT ACROSS THE AREA.
THE HEIGHT FALLS...ENERGY PERTURBANCES AT MID LEVELS...AND A SPEED
MAX AT 500MB KEEPS THE STAGE SET FOR CONVECTIVE REDEVELOPMENT THROUGH
THE NIGHT INTO THURSDAY. INCREASING PWS...TOWARD 1.5 INCHES...THROUGH
THE AREA WILL CONTRIBUTE TO A POTENTIAL FOR HEAVY TO EXCESSIVE
AMOUNTS OF RAIN TONIGHT....ESPECIALLY IF SOLID COLD POOLS DEVELOP
ALONG WITH TRAINING OF CELLS. HOWEVER...CONFIDENCE IN ANY EXACT
SCENARIO REMAINS LOW GIVEN THE DEVELOPING CONVECTION PATTERN AND THE
CHALLENGE OF PREDICTING SUBSEQUENT INITIATION OFF OF THE SOUTHWARD
MOVING OUTFLOW BOUNDARIES. A LACK OF A CAP AND LIS TO -6/CAPES TO
2000 J/KG WILL ALSO MEAN A GOOD POTENTIAL FOR SEVERE WEATHER WITH ANY
ORGANIZED STORMS THIS EVENING AND INTO THE OVERNIGHT...SHOULD PRIOR
CONVECTION NOT STABILIZE THE ENVIRONMENT. HAVE HIT THIS POTENTIAL
HARD IN THE GRIDS...ZONES...AND HWO. AFTER A MILD NIGHT...A BOUNDARY
SHOULD BE LAYING FROM NORTHWEST TO SOUTHEAST ACROSS EAST KENTUCKY
WITH STILL A POTENTIAL FOR STRONG STORMS ACROSS SOUTHWESTERN PARTS
OF THE AREA. HAVE CONTINUED THIS THREAT INTO THE AFTERNOON. THE
BOUNDARY SHOULD WEAKEN AND DRIFT FURTHER SOUTHEAST INTO THE NIGHT
WITH LESS OF A RISK FOR CONVECTION. COOLER TEMPS WILL BE FOUND
THURSDAY NIGHT OVER OUR NORTHEAST WITH MILDER AND MUGGIER CONDITIONS
SOUTHWEST.
USED THE BCCONSSHORT GRIDS AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN TACKED ON
THE BCCONSALL. MOST ADJUSTMENTS WHERE MADE FOR TERRAIN DIFFERENCES
TONIGHT AND THURSDAY NIGHT. AS FOR POPS...ENDED UP ON THE HIGH SIDE
OF ALL GUIDANCE...BUT CLOSEST TO THE HIGHER MET NUMBERS TONIGHT AND
THURSDAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 300 PM EDT WED MAY 21 2014
EXTENDED MODELS ARE IN REASONABLE AGREEMENT THROUGH THE PERIOD...BUT
AS USUAL THERE IS BETTER AGREEMENT WITH LARGE SCALE FEATURES THAN
WITH DETAILS. WE START WITH AN UPPER LEVEL DISTURBANCE THAT DROPS
SOUTHEAST THROUGH THE REGION FRIDAY...EFFECTIVELY JUMP STARING A
TEMPORARILY STALLED OUT SFC COLD FRONTAL BOUNDARY AND SWEEPING IT
OUT OF OUR AREA. THEREAFTER UPPER LEVEL RIDGING AND SFC HIGH
PRESSURE WILL BUILD OVER OUR AREA AND PROVIDE US WITH VERY PLEASANT
WEATHER FOR THE UPCOMING WEEKEND.
MODELS DIFFER MORE WITH RETURN FLOW REGIME EARLY NEXT WEEK. WARM
FRONTAL ZONE WILL MOVE BACK TO THE NORTH ACROSS THE AREA MONDAY AND
COULD PROVIDE SOME PRECIPITATION TO EASTERN KENTUCKY. THEREAFTER WE
FIND OURSELVES IN THE WARM SECTOR AND MORE SUMMER LIKE WEATHER UNTIL
THE POTENTIAL ARRIVAL OF A LOW PRESSURE SYSTEM THAT WILL SLOWLY
MEANDER ITS WAY OUT OF THE CENTRAL PLAINS. 0Z ECMWF WANTS TO BRING
THIS SLOW MOVING DISTURBANCE INTO THE HEART OF THE OHIO VALLEY BY
LATE THURSDAY INTO FRIDAY...JUST BEYOND THE FORECAST WINDOW. A MUCH
MORE INCONSISTENT GFS...AND MORE SPECIFICALLY THE 12Z RUN WANTS TO
TAKE THE DISTURBANCE TO THE GULF COAST...WHILE DEVELOPING A MUCH
STRONGER SYSTEM OVER THE OHIO VALLEY FROM ENERGY DROPPING OUT OF
CANADA DURING THAT SME TIME FRAME. PAST RUNS OF THE ECMWF HAVE SHOWN
A TENDENCY TO TAKE THE DISTURBANCE TO THE GULF COAST AS WELL...BUT
HAS NOT SHOWN ANY EVIDENCE OF SUCH A STRONG SYSTEM DROPPING OUT OF
CANADA.
FOR SENSIBLE WEATHER...ATMOSPHERE STABILIZES RAPIDLY EARLY FRIDAY
MORNING. SO ANY SHOWERS THAT MIGHT LINGER ACROSS THE AREA THURSDAY
NIGHT WILL COME TO AN END JUST AS QUICKLY EARLY FRIDAY MORNING. HIGH
PRESSURE AND A PLEASANTLY COOL AIR MASS OVER THE AREA WILL PROVIDE
GREAT WEATHER FOR THE WEEKEND. WEATHER WILL TURN MUGGY AND RELATIVELY
HOT EARLY NEXT WEEK AFTER A WARM FRONT PUNCHES ITS WAY ACROSS OUR
AREA TO THE NORTH. FOR NOW IT APPEARS THE THREAT OF SHOWERS AND
THUNDERSTORMS WILL INCREASE DAILY THROUGH THE REMAINDER OF THE
WEEK...BUT MUCH WILL DEPEND ON THE PATTERN THAT SETS UP AT THE END
OF THE FORECAST WINDOW AND BEYOND. THE ECMWF AND GFS BOTH ADVERTISE
UNSETTLED WEATHER OVER OUR AREA BY THE END OF THE WEEK BUT VIA
DIFFERENT MEANS TO THAT END. AT THIS POINT AND AFTER CONSIDERING THE
TIME OF YEAR THOUGHTS ARE THAT ANYTHING IS POSSIBLE BEYOND TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 220 PM EDT WED MAY 21 2014
CONDITIONS ARE CURRENTLY VFR THROUGH THE AREA...BUT CIGS ARE NEAR
MVFR IN THIS HUMID ENVIRONMENT. CONVECTION IS EXPECTED LATER THIS
EVENING THROUGH THE ENTIRE FORECAST AREA WITH A POTENTIAL FOR
ORGANIZED AND UPSCALE DEVELOPMENT. INITIALLY...HAVE TIMED A
CONVECTIVE EVENT THROUGH THE TAF SITES DURING THE MID EVENING BASED
ON THE LATEST HRRR. HAVE LEFT VCTS IN THE TAFS FOR THE REST OF
THE NIGHT DUE TO A CONTINUED POTENTIAL FOR REDEVELOPMENT ALONG WITH
MVFR CIGS. THERE WILL LIKELY BE A LULL AND BETTER CONDITIONS FOR A
TIME EARLY IN THE MORNING OF THURSDAY...BUT FOR NOW WILL LEAVE THE
VCTS AND LOWER CIGS PREVAILING. WINDS WILL BE BREEZY FROM THE WEST
SOUTHWEST THROUGH THE EVENING WITH GUSTS TO 20 AND 25 KTS...BUT
CLOSER TO 35 KTS...OR HIGHER...WITH ANY STORMS THIS EVENING. WEST
WINDS OF 10 TO 20 KTS FOLLOW THROUGH THE REMAINDER OF THE TAF PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...RAY
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
310 PM EDT WED MAY 21 2014
.UPDATE...
ISSUED AT 310 PM EDT WED MAY 21 2014
WITH THE EVOLUTION OF THIS EVENT COMING INTO CLEARER FOCUS...PER THE
LATEST HRRR AND OUTLOOKS/WATCH BOXES FROM SPC...HAVE UPDATED THE POP
AND WX GRIDS THROUGH THE NIGHT. DID ADD SOME ISOLATED SVR WORDING FOR
WIND AND HAIL TO THE GRIDS FOR THE EVENING OVER OUR NORTHERN ZONES.
ALSO FINE TUNED THE TEMPS AND DEWPOINTS THROUGH THE REST OF THE
AFTERNOON. THESE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1030 AM EDT WED MAY 21 2014
13Z SFC ANALYSIS SHOWS A BROAD AREA OF LOW PRESSURE THROUGH THE GREAT
LAKES AND INTO NORTHERN OHIO. A COLD FRONT IS LOCATED OVER THE
NORTHWEST PORTION OF THE OHIO VALLEY. THIS PLACES EAST KENTUCKY IN A
LARGE WARM SECTOR WELL TO THE SOUTH OF THIS BOUNDARY. DEWPOINTS HAVE
COME UP INTO THE UPPER 50S THROUGH THE AREA WITH LOW 60S POOLING
ALONG AND AHEAD OF THIS FRONT WHERE PWS ARE APPROACHING 1.6 INCHES.
MEANWHILE...TEMPERATURES HAVE CLIMBED INTO THE LOW 70S ALREADY...ON
THEIR WAY TO THE LOWER 80S. CONVECTION IS ONGOING THROUGH THE
NORTHERN PARTS OF THE REGION IN CONNECTION WITH THE LOW AND ITS
FRONTAL STRUCTURE. THIS IS INDICATIVE OF THE ENVIRONMENT AND
CONDITIONS SHOULD ONLY BECOME MORE FAVORABLE IN THE REGION TO THE
NORTH OF THE CWA AS THE DAY WEARS ON...TEMPERATURES SOAR...AND
INSTABILITY CLIMBS. EXPECT OUTFLOW BOUNDARIES FROM THE ONGOING AND
SUBSEQUENT CONVECTION TO WORK THEIR WAY SOUTH INTO EAST KENTUCKY BY
LATE AFTERNOON...PERHAPS ENOUGH SO TO TRIGGER OUR OWN ROUND OF
STORMS...AS THE 12Z NAM SUGGESTS. MOST LIKELY...THOUGH...THE HRRR
HAS THE RIGHT IDEA OF DEVELOPMENT HOLDING OFF UNTIL CLOSER TO 00Z
WHEN A CONVECTIVE CLUSTER IN SOUTHERN INDIANA AND OHIO SURGES INTO
NORTHERN KENTUCKY BRINGING ITS STORMY WEATHER TO OUR PART OF THE
STATE. THE FORECAST SOUNDINGS SUPPORT THIS SCENARIO KEEPING OUR AREA
CAPPED UNTIL AFTER 21Z...WHILE THE INSTABILITY GROWS. ONCE THE CAP IS
GONE THE WIND STRUCTURE THROUGH THE MID LEVELS HAS PRETTY GOOD SPEED
SHEAR TO ACCOMPANY CAPES TO 2K J/KG AND LIS TO -6. THE MIDDAY
SOUNDING EXPECTED OUT OF ILN WILL ALSO HELP TO TELL THE TALE. ALL
THIS SUPPORTS SPC/S SLIGHT RISK MONIKER FOR US THIS AFTERNOON AND
EVENING WITH LARGE HAIL AND DAMAGING WIND GUSTS THE MAIN THREATS.
WILL CONTINUE TO HIGHLIGHT THIS IN THE HWO AND HAVE ADDED A WEB
HEADLINE. OTHERWISE...MADE ONLY SLIGHT ADJUSTMENTS TO THE POP AND WX
GRIDS THROUGH 00Z WITH SOME TWEAKS TO TEMPERATURES AND DEWPOINTS
THROUGH THE REST OF THE DAY PER THE LATEST GUIDANCE...OBS...AND
TRENDS. THESE UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 727 AM EDT WED MAY 21 2014
FORECAST ON TRACK SO FAR THIS MORNING SO NO UPDATE IS PLANNED AT THIS
TIME.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 3 AM EDT WED MAY 21 2014
THE MODELS WERE ALL IN PRETTY GOOD AGREEMENT WITH THE LARGE SCALE
WEATHER PATTERN OVER THE NEXT 36 HOURS...THE TIMING OF A FRONTAL
PASSAGE LATER TODAY...AND THE AREAL COVERAGE OF PRECIPITATION
ASSOCIATED WITH THE FRONT. THE TIMING OF THE SOUTHWARD PROGRESSION OF
THE FRONT AND ITS ATTENDANT PRECIPITATION DID SEEM A BIT SLOWER THAN
THE PREVIOUS FORECAST SUGGESTED...SO ADJUSTMENTS WERE MADE TO ACCOUNT
FOR THIS. THE SREF AND NAM12 WERE BOTH USED IN CONJUNCTION TO CREATE
THE NEW FORECAST WITH THEIR PREFERRED FRONTAL PASSAGE TIMING AND
PRECIP DISTRIBUTION ALONG THE FRONT. THE MODEL SOUNDINGS ALL AGREED
THAT STRONG CAPPING WILL BE IN PLACE THROUGH EARLY THIS AFTERNOON.
WITH THAT IN MIND...IT SEEMED THAT LIKELY POPS WOULD BE A BIT
OVERDONE...SO THE NEW FORECAST WILL FEATURE A GENERAL 40 TO 50
PERCENT CHANCE OF RAIN THIS AFTERNOON AND EVENING...WITH SLOWER
SOUTHWARD FRONTAL MOVEMENT. AT THIS TIME THE PRIMARY FORECAST WILL BE
WHETHER OR NOT THERE IS STRONG ENOUGH FORCING AVAILABLE TO OVERCOME
THE STRONG CAPPING INVERSION SEEN IN THE MODEL SOUNDINGS AS AN
ONGOING LINE OF SHOWERS AND STORMS FINALLY MAKES IT WAY INTO THE
LATER TODAY. IT DOES APPEAR THAT WITH THE FRONT PUSHING THROUGH THAT
THERE WILL BE JUST ENOUGH FORCING...LOW LEVEL MOISTURE...AND
INSTABILITY AVAILABLE TO BREAK THE CAP EARLY THIS AFTERNOON. THE
CURRENT SOUNDINGS ARE SUPPORTIVE OF STRONG LOW LEVEL DRYING AND
THEREFORE ENHANCED THUNDERSTORM DOWNDRAFT POTENTIAL...MAKING DAMAGING
WINDS THE PRIMARY THREAT WITH ANY STORMS THAT AREA ABLE TO REACH
SEVERE LIMITS THIS AFTERNOON AND EVENING. SOUTHERLY TO SOUTHWESTERLY
WINDS AHEAD OF THE FRONT WILL PICK UP INTENSITY RATHER QUICKLY THIS
MORNING AS THE SUN BEGINS TO HEAT THINGS UP. SUSTAINED WINDS OF 10 TO
15 MPH WITH GUSTS OF 20 TO 25 MPH WILL BE POSSIBLE THROUGHOUT THE DAY
AHEAD OF THE FRONT.
THE FRONT WILL BE SLOW TO EXIT THE AREA AND MAY ACTUALLY STALL OUT
DURING THE OVERNIGHT HOURS...ALLOWING FOR LINGERING CHANCES OF
SHOWERS AND STORMS OVERNIGHT AND THROUGH THE DAY ON THURSDAY. IT DOES
APPEAR THAT THE FRONT WILL WASH OUT A BIT ON THURSDAY AS THE AIR MASS
NORTH OF THE BOUNDARY WILL ONLY BE SLIGHTLY DRIER THAN THAT TO THE
SOUTH OF IT. WITH THAT IN MIND...DECIDED TO GO WITH GENERAL CHANCE
POPS FOR TONIGHT AND TOMORROW...WITH THE HIGHEST RAIN CHANCES IN THE
AFTERNOON DURING PEAK HEATING. WITH THE CAPPING INVERSION ALL BUT
GONE ON THURSDAY...ANY STORMS THAT GO UP COULD BECOME STRONG WITH
GUSTY WINDS AND PERHAPS EVEN SMALL HAIL POSSIBLE.
TEMPERATURES TODAY ARE ONCE AGAIN EXPECTED TO TOP OUT IN THE LOWER
80S...WHICH IS WELL ABOVE NORMAL FOR THIS TIME OF YEAR. TEMPERATURES
ON THURSDAY LOOK BE JUST A BIT COOLER DUE AS A SLIGHTLY COOLER AND
DRIER AIR MASS INVADES THE AREA BEHIND A SLOWLY DEPARTING COLD FRONT.
HIGHS ON THURSDAY WILL STILL LIKELY MAX OUT AT AROUND 80 DEGREES
ACROSS THE AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 358 AM EDT WED MAY 21 2014
THE MODELS REMAIN IN GOOD AGREEMENT THROUGH THE LONG TERM...WITH
A BLOCKY PATTERN TO DOMINATE ACROSS THE CONUS. AN UPPER LEVEL LOW
WILL START OFF ACROSS SOUTHERN CALIFORNIA...WITH BROAD TROUGHING
ACROSS SOUTHEASTERN CANADA AND NEW ENGLAND. AN UPPER LEVEL RIDGE
WILL EXTEND ACROSS THE CENTER PART OF THE COUNTRY...STEMMED FROM THE
HIGH CENTER LOCATED NEAR THE FLORIDA PANHANDLE. THE HIGH WILL GET
SUPPRESSED FURTHER SOUTH AND SOUTHWEST INTO THE GULF OF MEXICO...AS
TROUGHING DEEPENS ACROSS NEW ENGLAND INTO THE WEEKEND. THE RESIDUAL
RIDGE AXIS WILL THEN SLOWLY SLIDE EASTWARD INTO THE MISSISSIPPI
VALLEY THROUGH THE HOLIDAY WEEKEND...AS THE CALIFORNIA UPPER LEVEL
LOW SLOWLY CHURNS ITS WAY INTO THE SOUTHERN PLAINS.
THURSDAY NIGHT WILL FEATURE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS EXITING THE SOUTHERN HALF OF THE FORECAST AREA...A FEW
OF WHICH COULD APPROACH SEVERE LIMITS BEFORE DIMINISHING. COOLER AND
DRIER AIR WILL MOVE IN FOR FRIDAY AND SATURDAY ACROSS EASTERN
KENTUCKY...WITH HIGHS GETTING KNOCKED BACK INTO THE MID 70S...WHILE
LOWS BOTTOM OUT IN LOW TO MID 50S FOR MOST LOCATIONS. THE UPPER LEVEL
RIDGE WILL THEN BUILD INTO THE AREA FOR THE SECOND HALF OF THE
HOLIDAY WEEKEND...WITH HIGHS RETURNING TO THE MID 80S BY MEMORIAL
DAY. ENOUGH MOISTURE MAY RETURN BY MONDAY TO ALLOW FOR ISOLATED
CONVECTION ALONG PORTIONS OF THE CUMBERLAND VALLEY. SCATTERED
CONVECTION WILL THEN THREATEN THE ENTIRE AREA BY TUESDAY...AS THE
RIDGE AXIS EDGES JUST OFF TO THE EAST AND ALLOWS FOR BETTER MOISTURE
RETURN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 220 PM EDT WED MAY 21 2014
CONDITIONS ARE CURRENTLY VFR THROUGH THE AREA...BUT CIGS ARE NEAR
MVFR IN THIS HUMID ENVIRONMENT. CONVECTION IS EXPECTED LATER THIS
EVENING THROUGH THE ENTIRE FORECAST AREA WITH A POTENTIAL FOR
ORGANIZED AND UPSCALE DEVELOPMENT. INITIALLY...HAVE TIMED A
CONVECTIVE EVENT THROUGH THE TAF SITES DURING THE MID EVENING BASED
ON THE LATEST HRRR. HAVE LEFT VCTS IN THE TAFS FOR THE REST OF
THE NIGHT DUE TO A CONTINUED POTENTIAL FOR REDEVELOPMENT ALONG WITH
MVFR CIGS. THERE WILL LIKELY BE A LULL AND BETTER CONDITIONS FOR A
TIME EARLY IN THE MORNING OF THURSDAY...BUT FOR NOW WILL LEAVE THE
VCTS AND LOWER CIGS PREVAILING. WINDS WILL BE BREEZY FROM THE WEST
SOUTHWEST THROUGH THE EVENING WITH GUSTS TO 20 AND 25 KTS...BUT
CLOSER TO 35 KTS...OR HIGHER...WITH ANY STORMS THIS EVENING. WEST
WINDS OF 10 TO 20 KTS FOLLOW THROUGH THE REMAINDER OF THE TAF PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...AR
LONG TERM...GEOGERIAN
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
635 AM EDT Wed May 21 2014
...Updated Aviation Discussion...
.SHORT TERM (Now through Thursday)...
Issued at 300 AM EDT Wed May 21 2014
...Severe Storms with Strong Wind Gusts Possible This Afternoon and
Evening...
Storms are firing early this morning on the northern edge of a ridge
anchored over Louisiana. Current trajectory of these storms should
keep precipitation away from our area this morning. However leftover
boundaries and an approaching cold front should provide the focus
for new storm development later this afternoon. Soundings continue
to advertise plenty of instability, with our high temperatures
forecast to reach the 80s, perhaps even upper 80s for some of our
warm spots along and west of I-65. That ridge will provide a cap on
development for most of the day here, but forecast soundings
indicate it will weaken as cooler air moves in here from the west
northwest flow aloft.
If this cap break happens earlier in the afternoon, we would see
some scattered storms develop. However still think the most likely
scenario will be for storms to develop first across central Indiana,
closer to the front and those boundaries mentioned above. These
storms would then organize into a line and push into our southeast
Indiana counties and Kentucky Bluegrass counties late in the
afternoon and evening hours. Hi-res WRF-NMM and ARW have backed off
on this scenario, instead opting for more widely scattered
convection areawide, whereas the local WRF fits our thinking.
Forecast soundings indicate downdraft CAPEs in the 1000-1500 range
ahead of this line, thus the main threat with these storms would be
damaging wind gusts. Secondary threats would be frequent to
excessive cloud to ground lightning as well as brief heavy rainfall.
That cold front will drift into the northern forecast area
overnight. Moisture pooling around, precipitable waters of 1.4-1.7
inches, may allow for additional storm development through the
night, but will limit overnight pops into the isolated/low-end
chance range. The front will continue southward during the day
Thursday. New convective development during the day will depend
greatly on what happens overnight. Think the most likely scenario is
enough of a break though to allow temperatures again to rise into
the 80s and allow storms to develop along the frontal boundary/old
outflow boundaries over south central Kentucky in the afternoon.
These storms once again could become severe, with damaging winds
again the primary threat.
.LONG TERM (Thursday night through Tuesday)...
Issued at 250 AM EDT Wed May 21 2014
Upper air pattern at 500mb late Thursday will feature ridging over
the plains, sandwiched between a deep nearly cutoff low near Las
Vegas and a shallow trough moving across the Great Lakes. Surface
high pressure of Canadian origin will build east towards Illinois,
pushing a weakening cold front south into Tennessee. Scattered
storms expected across southern Kentucky will diminish Thursday
evening with the loss of daytime heating.
Although the remnants of this front will stall across Tennessee and
extreme western Kentucky Friday, giving them scattered storms,
northeast winds over much of the Commonwealth will auger in drier
and slightly cooler air. Dewpoints will fall to near 50 across
northern Kentucky Friday. Friday will see the coolest temperatures
of the entire upcoming week with highs ranging from near 80 south to
as cool as the mid 70s across the northern Bluegrass. Expect mostly
clear skies Friday and Saturday with two refreshingly cool nights.
By early Sunday, the closed low over the desert southwest will
slowly move towards the Texas Panhandle. Strong 500mb ridging will
begin to build over the Lower Ohio Valley. By mid-week, strong
ridging will form an arc around the remnants of this closed low,
which is forecast to become nearly cutoff by both the GFS and the
ECMWF.
In a nutshell, a very summer-like regime will set up beginning
Sunday for a large portion of the Lower Ohio and Mississippi
Valleys. Humidities and dewpoints will increase a bit by Sunday and
especially by Monday, back towards the lower to mid 60s. However,
believe the latter half of the weekend will stay dry as any
convection will be inhibited by poor lapse rates and overhead 500mb
ridging. Highs Sunday and Monday will rise from the mid 80s Sunday
to a possibility of summer`s first 90 degree reading on Monday.
A typical summer-like pattern will continue Tuesday and for probably
much of the next workweek. Warm and humid conditions expected
Tuesday with a chance of afternoon and evening thunderstorms and
highs in the mid to upper 80s.
&&
.AVIATION (12Z TAF Update)...
Issued at 635 AM EDT Wed May 21 2014
Low pressure to our northwest is firing off storms across northern
IL/IN this hour. This low will drag a cold front toward the region
this afternoon. Latest HRRR and local WRF now going along with early
forecast reasoning of a line of storms forming over central Indiana
mid afternoon and pushing into the KSDF/KLEX terminals at some point
late in the afternoon or evening. Continue to have a PROB30 group
for both sites for stronger winds gusts and IFR conditions.
Continued development overnight is more in question, but the
presence of the front across the region late along with residual
moisture may allow for further storms late. Have slightly higher
confidence in this solution over KLEX, so have VCTS for them through
the night. Outside of storms today, winds will gust from the
southwest later this morning and afternoon, with peak gusts of 20-25
knots.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Short Term........RJS
Long Term.........JSD
Aviation..........RJS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
928 PM EDT THU MAY 22 2014
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE CHESAPEAKE BAY LATE THIS
EVENING BEFORE MOVING OFF THE DELMARVA COAST OVERNIGHT. AN UPPER-
LEVEL DISTURBANCE WILL MOVE THROUGH THE AREA FRIDAY...FOLLOWED BY
HIGH PRESSURE BUILDING IN FOR THE WEEKEND. THE HIGH MOVES OFFSHORE
EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE GREAT LAKES.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
SFC COLD FRONT ANALYZED JUST TO THE WEST OF THE MD CHSPK BAY AT 00Z.
THE COLD FRONT MOVES OFFSHORE BY AROUND MIDNIGHT. SFC DEWPOINTS IN
THE MID 60S AHEAD OF THE FRONT DECREASE BY 10-15 DEG F AS BREEZY NW
WINDS ADVECTS DRIER AIR BEHIND THE FRONT.
EXPECT STRATOCU TO DEVELOP OVER THE POTOMAC HIGHLANDS DURING THE
ERY MRNG HRS AS GREAT LAKES MOISTURE IS TRANSPORTED DOWNSTREAM AND
FCST MODEL SOUNDINGS INDICATE SATURATION AT THE TOP OF THE
BOUNDARY LAYER.
POST-FRONTAL CAA PATTERN HAS TAKEN A LITTLE BIT LONGER TO BECOME
ESTABLISHED THAN WHAT MODELS HAD INDICATED PER THERMAL COMPARISON
OF 00Z RAOBS AT IAD/PBZ/RNK TO 6-H FCSTS FROM THE 18Z NAM/GFS.
BASED ON THAT ASSESSMENT...TOOK A BLEND OF THE HRRR AND OUR LOCAL
WRF-ARW4N FOR MIN TEMPS TNGT WHICH WERE THE WARMEST GUIDANCE
AVAILABLE. MIN TEMPS RANGE FROM THE MID 40S ALONG THE ALLEGHENY
FRONT TO NEAR 60F IN THE CITIES AND NEAR THE BAY.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
A COOLER DAY FRI AS CD FNT PUSHES S OF THE CWA. DOMINANT FEATURE
WL BECOME AN UPR LVL LOW FORMING OVR NY/SRN QUEBEC. MOST LKLY THE
MRNG WL START OUT M SUNNY...THEN INCSRG CLDS DURG ERLY AFTN AS LO
LVL INSTABILITY DVLPS FM THE SHARP LO LVL LAPSE RATES. BECAUSE OF
THIS THERE WL BE A CHC RW DURG THE ERLY/MID AFTN...THE MOST LKLY
LOCATION WOULD BE CLOSE TO THE MASON-DIXON LN.
HIGHS SHOULD BE IN THE MU70S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
AN UPPER-LEVEL DISTURBANCE WILL SHIFT EAST OF THE AREA FRIDAY NIGHT
AND HIGH PRESSURE WILL BUILD OVERHEAD. ANY LEFTOVER SHOWERS FRIDAY
EVENING WILL DISSIPATE AND IT WILL TURN OUT DRY AND COOL FRIDAY
NIGHT.
HIGH PRESSURE WILL REMAIN OVERHEAD FOR THE WEEKEND...BRINGING MAINLY
DRY AND SEASONABLY WARM CONDITIONS. A COUPLE SHOWERS CANNOT BE RULED
OUT SATURDAY AFTERNOON ACROSS NORTHERN MARYLAND INTO THE WASHINGTON
AND BALTIMORE METROPOLITAN AREAS DUE TO LIMITED INSTABILITY.
HOWEVER...MUCH OF THE TIME WILL TURN OUT DRY.
HIGH PRESSURE WILL MOVE OFF THE COAST MONDAY AND A RETURN FLOW WILL
BRING WARMER AND MORE HUMID CONDITIONS. A COLD FRONT WILL PASS
THROUGH THE REGION TUESDAY AND IT WILL STALL OUT NEARBY FOR
WEDNESDAY AND THURSDAY...BRINGING THE CHANCE FOR SHOWERS AND
THUNDERSTORMS.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
COLD FRONT HAS MOVED EAST OF THE TERMINALS AS OF 01Z. NW WINDS
GUSTING 15-20 KT FOR A FEW HRS BEHIND THE FRONT THIS EVE. WINDS
SUBSIDE A BIT OVNGT BEFORE DAYTIME MIXING ENSUES AND WINDS GUST
20-25 KT ON FRI. VFR TNGT AND FRI. STRATOCU FIELD 4-6 KFT DEVELOPS
ON FRI.
VFR CONDS ARE XPCTD FRI NGT AND SAT. WINDS WL TURN TO THE NW W/
GUSTS UP TO 20-25 KT. SCT RW ARE PSBL SAT AFTN.
VFR CONDITIONS WILL PERSIST FRIDAY NIGHT THROUGH MONDAY AS HIGH
PRESSURE BUILDS OVERHEAD.
&&
.MARINE...
WINDS HAVE BEEN BELOW SCA THRESHOLD THUS FAR THIS EVE BUT COLD
FRONT IS CURRENTLY MOVING THRU THE WATERS. NW WINDS WILL INCREASE
BEHIND THE FRONT AND GUST TO 20 KT. SCA IS IN EFFECT TNGT AND FRI.
A PRESSURE SURGE IS EXPECTED AHEAD OF BUILDING HIGH PRESSURE FRIDAY
NIGHT. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE MARYLAND
CHESAPEAKE BAY AND LOWER TIDAL POTOMAC RIVER. THE SMALL CRAFT MAY
NEED TO BE EXTENDED INTO SATURDAY...BUT WINDS WILL DIMINISH LATER
SATURDAY AND SUNDAY AS HIGH PRESSURE BUILDS OVERHEAD.
HIGH PRESSURE WILL MOVE OFF THE COAST MONDAY AND A COLD FRONT MAY
IMPACT THE WATERS TUESDAY INTO WEDNESDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ530>534-
537-539>541-543.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT FRIDAY FOR ANZ538.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ535-
536-542.
SMALL CRAFT ADVISORY FROM 10 AM TO 8 PM EDT FRIDAY FOR ANZ535-
536-542.
&&
$$
UPDATE...KLEIN
PREV DISC...KLEIN/WOODY!/BJL/CEM
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
102 PM EDT WED MAY 21 2014
.AVIATION...
//DISCUSSION...
A COLD FRONT NOW OVER WRN LOWER MI AND WEAK WARM FRONTAL FEATURE NOW
LOCATED BETWEEN FNT AND MBS WILL BE THE TRIGGER FOR SCATTERED TO
POSSIBLY NUMEROUS THUNDERSTORM COVERAGE LATE THIS AFTERNOON. THE
COLD FRONT IS EXPECTED TO MOVE FROM EAST TO WEST ACROSS SE MI
BETWEEN 21Z AND 00Z. INCREASING INSTABILITY IN ADVANCE OF THIS FRONT
WILL HELP FUEL THE THUNDERSTORMS. GIVEN THE TIMING OF THE
FRONT...THERE IS REASONABLE CONFIDENCE THAT THE COVERAGE OF STORMS
LATE THIS AFTERNOON WILL BE ENOUGH TO JUSTIFY A TWO TO THREE HOUR
PERIOD OF THUNDERSTORMS IN THE TAFS. THE EXCEPTION WILL BE MBS WHERE
THE EARLIER FROPA MAY NOT ALLOW ENOUGH TIME FOR THUNDERSTORM
DEVELOPMENT. OBSERVATIONS SUGGEST THAT DAYTIME HEATING IS LIFTING
THE BASES OF THE MVFR STRATO CU FIELD...SUGGESTING BASES WILL LIKELY
FALL INTO THE 3500 TO 4500 FT RANGE PRIOR TO FROPA.
FOR DTW...THE FRONT SHOULD PUSH ACROSS METRO BETWEEN 22 AND 23Z. IT
REMAINS UNCLEAR JUST HOW EXTENSIVE THUNDERSTORM COVERAGE WILL BE AS
THERE IS LIKELY TO BE A CAPPING INVERSION PRESENT. THERE IS STILL A
POTENTIAL FOR STRONG STORMS LATE THIS AFTERNOON/EARLY EVENING WHICH
COULD IMPACT A GOOD PORTION OF METRO AIRSPACE.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE FOR THUNDERSTORMS BETWEEN 21Z AND 23Z.
* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET THIS AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 1106 AM EDT WED MAY 21 2014
UPDATE...
A REGION OF MID LEVEL SUBSIDENCE IN THE WAKE OF THE EARLY MORNING
THUNDERSTORM COMPLEXES HAS ESSENTIALLY SHUT DOWN CONVECTION THIS
MORNING. A LINGERING RESERVOIR OF LOW LEVEL MOISTURE OVER SOUTHERN
MICHIGAN HAS BEEN ALLOWING THE RAPID DEVELOPMENT OF STRATO CU AS
DIURNAL HEATING HAS KICKED IN. COVERAGE AND INTENSITY OF
AFTERNOON/EVENING THUNDERSTORMS WILL BE PREDICATED UPON HOW WELL
DIURNAL MIXING ERODES SOME OF THESE LOW CLOUDS AND WEAKENS A MID
LEVEL CAP. THE 14Z SURFACE ANALYSIS SHOWS AN ELONGATED REGION OF
LOW PRESSURE OVER SRN LOWER MI WITH AN ENHANCED REGION OF
CONVERGENCE ALONG A SFC TROUGH OVER THE WRN LAKE MI SHORELINE. THE
12Z NAM/RAP/HRR ALL SHOW THIS BOUNDARY ADVANCING INTO SE MI THIS
AFTERNOON...WHILE A MORE E-W ORIENTED BOUNDARY NOTED JUST SOUTH OF
THE I-69 CORRIDOR REMAINS NEARLY STATIONARY. THE LOW LEVEL WIND
FIELD MAY ALSO REMAIN WEAK ENOUGH TO ALLOW SOME LAKE BREEZE
DEVELOPMENT ALONG THE LAKES HURON/ST CLAIR/ERIE SHORELINES. THESE
BOUNDARIES WILL BE THE MAIN FOCUS FOR CONVECTIVE INITIATION LATER
TODAY. 12Z UPSTREAM RAOBS DO SUPPORT MODEL SOLUTIONS IN SHOWING A
WEDGE OF MID LEVEL DRY ACROSS THE UPPER MIDWEST. THIS OTHER REGION
OF MID LEVEL SUBSIDENCE AND PUSH OF DRY AIR IS EXPECTED TO ADVANCE
INTO SE MI BETWEEN 21Z AND 00Z. THE CONCERN IS WHETHER THERE WILL
BE ENOUGH INSTABILITY TO OVERCOME THE CAP PRIOR TO THE ARRIVAL OF
THIS REGION OF SUBSIDENCE.
SFC DEWPOINTS HAVE BEEN RISING WITH THE ONSET OF DAYTIME
HEATING...A SIGN OF RESPECTABLE LOW LEVEL MOISTURE DEPTH. THUS
MODEL SOUNDINGS AND THE MODIFIED 12Z DTX SOUNDING SUGGESTIVE OF
0-1KM ML CAPE OF 1500-2K J/KG SEEM REASONABLE IF SFC TEMPS CAN
PUSH 80 DEG THIS AFTERNOON. 0-6KM BULK SHEAR UP TO 40 KNOTS AND MID
LEVEL DRY AIR ADVECTION RAISES CONCERNS FOR SEVERE STORM POTENTIAL
LATER TODAY. THE SHEAR/INSTABILITY COMBINATION WILL BE FAVORABLE TO
BOTH SUPERCELLS AND LINEAR MODES OF CONVECTION...WITH DAMAGING
WIND GUSTS AND LARGE HAIL A CONCERN. SINCE THE COVERAGE AND
SEVERITY OF CONVECTION WILL RELY ON THE DEGREE OF AFTERNOON
DESTABILIZATION AND MID LEVEL CAP STRENGTH...AN 18Z DTX SOUNDING
WILL BE DONE TODAY.
PREV DISCUSSION...ISSUED 343 AM EDT WED MAY 21 2014
SHORT TERM... TODAY AND TONIGHT
SURFACE AND MODEL ANALYSIS FIELDS PROVIDE A STRAIGHTFORWARD
DIAGNOSIS FOR ONGOING CONVECTIVE FORCING BUT THAT STILL LEAVES A
CHALLENGING FORECAST FOR WHAT MAY FOLLOW LATER TODAY THROUGH THIS
EVENING UNTIL THE SURFACE COLD FRONT PUSHES THROUGH THE REGION
CLOSER TO MIDNIGHT.
THE LARGE SCALE PATTERN IS ANCHORED BY A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WHICH HAS AN OCCLUDED FRONT EXTENDING INTO
A BROADER SURFACE WAVE OVER LOWER MICHIGAN RIPPLING ALONG THE MAIN
WARM/STATIONARY FRONT EXTENDING INTO OUR AREA. THE LOW LEVEL
MOISTURE AXIS IS ALIGNED ALONG THIS SURFACE PRESSURE FEATURE WITH
BACKGROUND VERTICAL MOTION SUPPLIED BY AGEOSTROPHIC CIRCULATION
UNDER THE SOUTH FLANK OF THE UPPER JET. THE RESULT IS CONTINUED
SUPPORT FOR ONGOING CONVECTION AND DEVELOPMENT OF ADDITIONAL SHOWERS
AND WEAKER STORMS NORTH OF THE SURFACE BOUNDARY. SINCE MIDNIGHT...
CONCERN HAS TRANSITIONED FROM SEVERE WEATHER POTENTIAL NEAR THE OHIO
BORDER TO EXCESSIVE RAINFALL THROUGH THE I-69 CORRIDOR...ALTHOUGH
INTENSITY OF STORMS WILL REMAIN STRONG NEAR THE OHIO BORDER WHERE
MID LEVEL LAPSE RATES ARE GREATEST. AT THE SAME TIME...EXPECT
COVERAGE OF SHOWERS AND STORMS WILL BE NUMEROUS FARTHER NORTH WITHIN
THE FRONTAL CIRCULATION IN THE 850-700 MB LAYER. BASED ON MODEL MEAN
RH TRENDS...THERE IS GOOD AGREEMENT THAT THIS CLUSTER OF CONVECTION
WILL MOVE EAST OF THE AREA AROUND NOON.
OTHER THAN A SLOW PROGRESSION OF THE SURFACE PRESSURE PATTERN...
THERE WILL NOT BE MUCH DIFFERENCE IN THE LARGE SCALE FEATURES
AFFECTING THE AREA DURING THE AFTERNOON COMPARED TO THE CURRENT
SETUP. THE CONSENSUS OF MODEL MSL PRESSURE SOLUTIONS PLACES THE
TRIPLE POINT OF THE OCCLUSION OVER NORTHERN LOWER MICHIGAN AROUND
18Z. SOUTHWEST FLOW RETURNING BEHIND THE MORNING CONVECTIVE PATTERN
WILL BE ADEQUATE TO MAINTAIN THUNDERSTORM POTENTIAL WITH SUFFICIENT
RECOVERY OF INSTABILITY. THE TIMING AND MAGNITUDE OF RECOVERY IS THE
MAIN UNCERTAINTY IN THE FORECAST AND SEVERE WEATHER POTENTIAL.
REASONABLE DOWNWARD ADJUSTMENTS TO THE LATEST NAM AND RAP OUTPUT
STILL OFFERS 0-1KM MLCAPE RECOVERING TO ABOUT 1500 J/KG MID TO LATE
AFTERNOON...BUT WITH MODEST MID LEVEL LAPSE RATES OF 6-7C/KM IN THE
700-500 MB LAYER AS THE EML SUPPORTING THE EARLY MORNING STORMS IS
DIRECTED INTO THE UPPER OHIO VALLEY. REMAINING IN PLACE WILL BE THE
SOUTHERN FRINGES OF DYNAMIC SUPPORT FROM THE UPPER WAVE OVER
NORTHERN ONTARIO...AND STRONG WESTERLY FLOW ALOFT OVER LOWER
MICHIGAN. MODEL SOUNDINGS INDICATE A SOLID STRAIGHT-LINE HODOGRAPH
ANCHORED BY 50-60 KNOTS OF FLOW AROUND 500 MB AND 0-6 KM BULK SHEAR
AROUND 50 KNOTS. DIFFERENT FROM YESTERDAY WILL BE A MORE VEERED LOW
LEVEL FLOW WHICH IS LESS FAVORABLE FOR TORNADOGENESIS...BUT THE
OVERALL PROFILE IS STILL SUPPORTIVE OF STORM SPLITS/SUPERCELL
ORGANIZATION EARLY IN THE CONVECTIVE CYCLE. PLAN TO CALL FOR
ISOLATED STORMS APPROACHING SEVERE LIMITS UNTIL SEVERE POTENTIAL CAN
BE REFINED WITH OBSERVATIONS AS THE DAY PROGRESSES. SHOWERS AND
WEAKER STORMS SHOULD OTHERWISE BECOME NUMEROUS BY LATER AFTERNOON
THROUGH THE EVENING BEFORE THE COLD FRONT SWEEPS EVERYTHING OUT OF
THE REGION AROUND MIDNIGHT.
LONG TERM...
COLD ADVECTION PATTERN EMBEDDED WITHIN CORRIDOR OF CYCLONIC
NORTHWEST FLOW ALOFT WILL PERSIST INTO FRIDAY MORNING. H85
TEMPERATURES ARE PROGGED TO FALL FROM 10C LATE TONIGHT TO 4C FRIDAY
MORNING. ONGOING COLD ADVECTION WILL ENSURE STEEP LOW-LEVEL LAPSE
RATES CAPABLE OF SUPPORTING EXPANSIVE AFTERNOON STRATOCU,
PARTICULARLY IN THE PRESENCE OF LOW AMPLITUDE DISTURBANCES RIPPLING
ALONG IN THE FLOW ALOFT. INFLUX OF THE COOLER AIRMASS COMBINED WITH
CLOUDS DEVELOPING DURING PEAK HEATING WILL LIMIT HIGHS TO THE
MID/UPPER 60S ON BOTH FRIDAY AND SATURDAY. HIGH AMPLITUDE RIDGE WILL
VERY GRADUALLY MIGRATE OVER THE GREAT LAKES THROUGH THE HOLIDAY
WEEKEND AS THE PATTERN SLOWS IN RESPONSE TO THE CLOSED LOW OVER THE
SOUTHWEST UNITED STATES. REBOUNDING THERMAL PROFILES WILL BE
ACCOMPANIED BY DEEP LAYER SUBSIDENCE, ADDING CONFIDENCE TO THE
FORECAST FOR A WARM AND MOSTLY SUNNY HOLIDAY WEEKEND. TEMPERATURES
WILL MODERATE FROM LOW/MID 70S ON SATURDAY TO THE LOW 80S BY MONDAY.
MARINE...
A WEAK COLD FRONT WILL SWING THROUGH THE CENTRAL GREAT LAKES THIS
AFTERNOON. BRISK NORTHWEST WINDS WILL THEN BUILD IN FOR TONIGHT AND
THURSDAY. ANY THUNDERSTORMS WHICH DEVELOP TONIGHT THROUGH TOMORROW
MAY BE STRONG TO SEVERE. LIGHT WINDS WILL RETURN FOR THE WEEKEND AS
HIGH PRESSURE SETTLES OVER THE AREA.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SC
UPDATE.......SC
SHORT TERM...BT
LONG TERM....JVC
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1106 AM EDT WED MAY 21 2014
.UPDATE...
A REGION OF MID LEVEL SUBSIDENCE IN THE WAKE OF THE EARLY MORNING
THUNDERSTORM COMPLEXES HAS ESSENTIALLY SHUT DOWN CONVECTION THIS
MORNING. A LINGERING RESERVOIR OF LOW LEVEL MOISTURE OVER SOUTHERN
MICHIGAN HAS BEEN ALLOWING THE RAPID DEVELOPMENT OF STRATO CU AS
DIURNAL HEATING HAS KICKED IN. COVERAGE AND INTENSITY OF
AFTERNOON/EVENING THUNDERSTORMS WILL BE PREDICATED UPON HOW WELL
DIURNAL MIXING ERODES SOME OF THESE LOW CLOUDS AND WEAKENS A MID
LEVEL CAP. THE 14Z SURFACE ANALYSIS SHOWS AN ELONGATED REGION OF
LOW PRESSURE OVER SRN LOWER MI WITH AN ENHANCED REGION OF
CONVERGENCE ALONG A SFC TROUGH OVER THE WRN LAKE MI SHORELINE. THE
12Z NAM/RAP/HRR ALL SHOW THIS BOUNDARY ADVANCING INTO SE MI THIS
AFTERNOON...WHILE A MORE E-W ORIENTED BOUNDARY NOTED JUST SOUTH OF
THE I-69 CORRIDOR REMAINS NEARLY STATIONARY. THE LOW LEVEL WIND
FIELD MAY ALSO REMAIN WEAK ENOUGH TO ALLOW SOME LAKE BREEZE
DEVELOPMENT ALONG THE LAKES HURON/ST CLAIR/ERIE SHORELINES. THESE
BOUNDARIES WILL BE THE MAIN FOCUS FOR CONVECTIVE INITIATION LATER
TODAY. 12Z UPSTREAM RAOBS DO SUPPORT MODEL SOLUTIONS IN SHOWING A
WEDGE OF MID LEVEL DRY ACROSS THE UPPER MIDWEST. THIS OTHER REGION
OF MID LEVEL SUBSIDENCE AND PUSH OF DRY AIR IS EXPECTED TO ADVANCE
INTO SE MI BETWEEN 21Z AND 00Z. THE CONCERN IS WHETHER THERE WILL
BE ENOUGH INSTABILITY TO OVERCOME THE CAP PRIOR TO THE ARRIVAL OF
THIS REGION OF SUBSIDENCE.
SFC DEWPOINTS HAVE BEEN RISING WITH THE ONSET OF DAYTIME
HEATING...A SIGN OF RESPECTABLE LOW LEVEL MOISTURE DEPTH. THUS
MODEL SOUNDINGS AND THE MODIFIED 12Z DTX SOUNDING SUGGESTIVE OF
0-1KM ML CAPE OF 1500-2K J/KG SEEM REASONABLE IF SFC TEMPS CAN
PUSH 80 DEG THIS AFTERNOON. 0-6KM BULK SHEAR UP TO 40 KNOTS AND MID
LEVEL DRY AIR ADVECTION RAISES CONCERNS FOR SEVERE STORM POTENTIAL
LATER TODAY. THE SHEAR/INSTABILITY COMBINATION WILL BE FAVORABLE TO
BOTH SUPERCELLS AND LINEAR MODES OF CONVECTION...WITH DAMAGING
WIND GUSTS AND LARGE HAIL A CONCERN. SINCE THE COVERAGE AND
SEVERITY OF CONVECTION WILL RELY ON THE DEGREE OF AFTERNOON
DESTABILIZATION AND MID LEVEL CAP STRENGTH...AN 18Z DTX SOUNDING
WILL BE DONE TODAY.
&&
.AVIATION...ISSUED 715 AM EDT WED MAY 21 2014
//DISCUSSION...
EXPECT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TRAILING THE
PRIMARY STORM CLUSTER OUT OF SE MICHIGAN DURING THE MORNING. MVFR
VISIBILITY WILL ALSO BE POSSIBLE DUE TO FOG THROUGH MID MORNING...
ESPECIALLY WHERE IT HAS RAINED AND WITHIN THE FRONTAL ZONE STRETCHED
WEST TO EAST IN THE FNT/PTK AREA. BOUNDARY LAYER TEMPERATURE
RECOVERY WILL THEN HELP IMPROVE CONDITIONS BY LATE MORNING OR EARLY
AFTERNOON AT THE LATEST. ATTENTION THEN TURNS TO THUNDERSTORM
CHANCES FOR THE MID TO LATE AFTERNOON WHICH WILL DEPEND ON THE
TIMING OF SURFACE HEATING AND THE EVENTUAL SHAPE THE SURFACE FRONT
TO FOCUS LOW LEVEL CONVERGENCE. AT THIS POINT...THE BEST ESTIMATE OF
INITIATION IS EAST OF FNT AND PTK BUT OVER THE DTW AREA MID TO LATE
AFTERNOON. THE COLD FRONT ASSOCIATED WITH THE LOW PRESSURE SYSTEM
OVER THE NORTHERN GREAT LAKES WILL THEN SCOUR ACTIVITY OUT OF THE
REGION BY MIDNIGHT. MVFR CEILING OVER MINNESOTA WILL BE MONITORED
FOR POTENTIAL TO SPREAD OVER LOWER MICHIGAN AFTER MIDNIGHT AND LAST
THROUGH SUNRISE THURSDAY...BUT LOW END VFR STRATOCU LOOKS LIKE A
GOOD BET AS THE COOLER AIR SPREAD OVER THE REGION TOWARD SUNRISE
THURSDAY.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE FOR THUNDERSTORMS LATE AFTERNOON.
* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET TODAY AND THEN TOWARD
SUNRISE THURSDAY.
&&
.PREV DISCUSSION...ISSUED 343 AM EDT WED MAY 21 2014
SHORT TERM... TODAY AND TONIGHT
SURFACE AND MODEL ANALYSIS FIELDS PROVIDE A STRAIGHTFORWARD
DIAGNOSIS FOR ONGOING CONVECTIVE FORCING BUT THAT STILL LEAVES A
CHALLENGING FORECAST FOR WHAT MAY FOLLOW LATER TODAY THROUGH THIS
EVENING UNTIL THE SURFACE COLD FRONT PUSHES THROUGH THE REGION
CLOSER TO MIDNIGHT.
THE LARGE SCALE PATTERN IS ANCHORED BY A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WHICH HAS AN OCCLUDED FRONT EXTENDING INTO
A BROADER SURFACE WAVE OVER LOWER MICHIGAN RIPPLING ALONG THE MAIN
WARM/STATIONARY FRONT EXTENDING INTO OUR AREA. THE LOW LEVEL
MOISTURE AXIS IS ALIGNED ALONG THIS SURFACE PRESSURE FEATURE WITH
BACKGROUND VERTICAL MOTION SUPPLIED BY AGEOSTROPHIC CIRCULATION
UNDER THE SOUTH FLANK OF THE UPPER JET. THE RESULT IS CONTINUED
SUPPORT FOR ONGOING CONVECTION AND DEVELOPMENT OF ADDITIONAL SHOWERS
AND WEAKER STORMS NORTH OF THE SURFACE BOUNDARY. SINCE MIDNIGHT...
CONCERN HAS TRANSITIONED FROM SEVERE WEATHER POTENTIAL NEAR THE OHIO
BORDER TO EXCESSIVE RAINFALL THROUGH THE I-69 CORRIDOR...ALTHOUGH
INTENSITY OF STORMS WILL REMAIN STRONG NEAR THE OHIO BORDER WHERE
MID LEVEL LAPSE RATES ARE GREATEST. AT THE SAME TIME...EXPECT
COVERAGE OF SHOWERS AND STORMS WILL BE NUMEROUS FARTHER NORTH WITHIN
THE FRONTAL CIRCULATION IN THE 850-700 MB LAYER. BASED ON MODEL MEAN
RH TRENDS...THERE IS GOOD AGREEMENT THAT THIS CLUSTER OF CONVECTION
WILL MOVE EAST OF THE AREA AROUND NOON.
OTHER THAN A SLOW PROGRESSION OF THE SURFACE PRESSURE PATTERN...
THERE WILL NOT BE MUCH DIFFERENCE IN THE LARGE SCALE FEATURES
AFFECTING THE AREA DURING THE AFTERNOON COMPARED TO THE CURRENT
SETUP. THE CONSENSUS OF MODEL MSL PRESSURE SOLUTIONS PLACES THE
TRIPLE POINT OF THE OCCLUSION OVER NORTHERN LOWER MICHIGAN AROUND
18Z. SOUTHWEST FLOW RETURNING BEHIND THE MORNING CONVECTIVE PATTERN
WILL BE ADEQUATE TO MAINTAIN THUNDERSTORM POTENTIAL WITH SUFFICIENT
RECOVERY OF INSTABILITY. THE TIMING AND MAGNITUDE OF RECOVERY IS THE
MAIN UNCERTAINTY IN THE FORECAST AND SEVERE WEATHER POTENTIAL.
REASONABLE DOWNWARD ADJUSTMENTS TO THE LATEST NAM AND RAP OUTPUT
STILL OFFERS 0-1KM MLCAPE RECOVERING TO ABOUT 1500 J/KG MID TO LATE
AFTERNOON...BUT WITH MODEST MID LEVEL LAPSE RATES OF 6-7C/KM IN THE
700-500 MB LAYER AS THE EML SUPPORTING THE EARLY MORNING STORMS IS
DIRECTED INTO THE UPPER OHIO VALLEY. REMAINING IN PLACE WILL BE THE
SOUTHERN FRINGES OF DYNAMIC SUPPORT FROM THE UPPER WAVE OVER
NORTHERN ONTARIO...AND STRONG WESTERLY FLOW ALOFT OVER LOWER
MICHIGAN. MODEL SOUNDINGS INDICATE A SOLID STRAIGHT-LINE HODOGRAPH
ANCHORED BY 50-60 KNOTS OF FLOW AROUND 500 MB AND 0-6 KM BULK SHEAR
AROUND 50 KNOTS. DIFFERENT FROM YESTERDAY WILL BE A MORE VEERED LOW
LEVEL FLOW WHICH IS LESS FAVORABLE FOR TORNADOGENESIS...BUT THE
OVERALL PROFILE IS STILL SUPPORTIVE OF STORM SPLITS/SUPERCELL
ORGANIZATION EARLY IN THE CONVECTIVE CYCLE. PLAN TO CALL FOR
ISOLATED STORMS APPROACHING SEVERE LIMITS UNTIL SEVERE POTENTIAL CAN
BE REFINED WITH OBSERVATIONS AS THE DAY PROGRESSES. SHOWERS AND
WEAKER STORMS SHOULD OTHERWISE BECOME NUMEROUS BY LATER AFTERNOON
THROUGH THE EVENING BEFORE THE COLD FRONT SWEEPS EVERYTHING OUT OF
THE REGION AROUND MIDNIGHT.
LONG TERM...
COLD ADVECTION PATTERN EMBEDDED WITHIN CORRIDOR OF CYCLONIC
NORTHWEST FLOW ALOFT WILL PERSIST INTO FRIDAY MORNING. H85
TEMPERATURES ARE PROGGED TO FALL FROM 10C LATE TONIGHT TO 4C FRIDAY
MORNING. ONGOING COLD ADVECTION WILL ENSURE STEEP LOW-LEVEL LAPSE
RATES CAPABLE OF SUPPORTING EXPANSIVE AFTERNOON STRATOCU,
PARTICULARLY IN THE PRESENCE OF LOW AMPLITUDE DISTURBANCES RIPPLING
ALONG IN THE FLOW ALOFT. INFLUX OF THE COOLER AIRMASS COMBINED WITH
CLOUDS DEVELOPING DURING PEAK HEATING WILL LIMIT HIGHS TO THE
MID/UPPER 60S ON BOTH FRIDAY AND SATURDAY. HIGH AMPLITUDE RIDGE WILL
VERY GRADUALLY MIGRATE OVER THE GREAT LAKES THROUGH THE HOLIDAY
WEEKEND AS THE PATTERN SLOWS IN RESPONSE TO THE CLOSED LOW OVER THE
SOUTHWEST UNITED STATES. REBOUNDING THERMAL PROFILES WILL BE
ACCOMPANIED BY DEEP LAYER SUBSIDENCE, ADDING CONFIDENCE TO THE
FORECAST FOR A WARM AND MOSTLY SUNNY HOLIDAY WEEKEND. TEMPERATURES
WILL MODERATE FROM LOW/MID 70S ON SATURDAY TO THE LOW 80S BY MONDAY.
MARINE...
A WEAK COLD FRONT WILL SWING THROUGH THE CENTRAL GREAT LAKES THIS
AFTERNOON. BRISK NORTHWEST WINDS WILL THEN BUILD IN FOR TONIGHT AND
THURSDAY. ANY THUNDERSTORMS WHICH DEVELOP TONIGHT THROUGH TOMORROW
MAY BE STRONG TO SEVERE. LIGHT WINDS WILL RETURN FOR THE WEEKEND AS
HIGH PRESSURE SETTLES OVER THE AREA.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......SC
AVIATION.....BT
SHORT TERM...BT
LONG TERM....JVC
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
715 AM EDT WED MAY 21 2014
.AVIATION...
//DISCUSSION...
EXPECT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TRAILING THE
PRIMARY STORM CLUSTER OUT OF SE MICHIGAN DURING THE MORNING. MVFR
VISIBILITY WILL ALSO BE POSSIBLE DUE TO FOG THROUGH MID MORNING...
ESPECIALLY WHERE IT HAS RAINED AND WITHIN THE FRONTAL ZONE STRETCHED
WEST TO EAST IN THE FNT/PTK AREA. BOUNDARY LAYER TEMPERATURE
RECOVERY WILL THEN HELP IMPROVE CONDITIONS BY LATE MORNING OR EARLY
AFTERNOON AT THE LATEST. ATTENTION THEN TURNS TO THUNDERSTORM
CHANCES FOR THE MID TO LATE AFTERNOON WHICH WILL DEPEND ON THE
TIMING OF SURFACE HEATING AND THE EVENTUAL SHAPE THE SURFACE FRONT
TO FOCUS LOW LEVEL CONVERGENCE. AT THIS POINT...THE BEST ESTIMATE OF
INITIATION IS EAST OF FNT AND PTK BUT OVER THE DTW AREA MID TO LATE
AFTERNOON. THE COLD FRONT ASSOCIATED WITH THE LOW PRESSURE SYSTEM
OVER THE NORTHERN GREAT LAKES WILL THEN SCOUR ACTIVITY OUT OF THE
REGION BY MIDNIGHT. MVFR CEILING OVER MINNESOTA WILL BE MONITORED
FOR POTENTIAL TO SPREAD OVER LOWER MICHIGAN AFTER MIDNIGHT AND LAST
THROUGH SUNRISE THURSDAY...BUT LOW END VFR STRATOCU LOOKS LIKE A
GOOD BET AS THE COOLER AIR SPREAD OVER THE REGION TOWARD SUNRISE
THURSDAY.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE FOR THUNDERSTORMS LATE AFTERNOON.
* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET TODAY AND THEN TOWARD
SUNRISE THURSDAY.
&&
.PREV DISCUSSION...ISSUED 343 AM EDT WED MAY 21 2014
SHORT TERM... TODAY AND TONIGHT
SURFACE AND MODEL ANALYSIS FIELDS PROVIDE A STRAIGHTFORWARD
DIAGNOSIS FOR ONGOING CONVECTIVE FORCING BUT THAT STILL LEAVES A
CHALLENGING FORECAST FOR WHAT MAY FOLLOW LATER TODAY THROUGH THIS
EVENING UNTIL THE SURFACE COLD FRONT PUSHES THROUGH THE REGION
CLOSER TO MIDNIGHT.
THE LARGE SCALE PATTERN IS ANCHORED BY A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WHICH HAS AN OCCLUDED FRONT EXTENDING INTO
A BROADER SURFACE WAVE OVER LOWER MICHIGAN RIPPLING ALONG THE MAIN
WARM/STATIONARY FRONT EXTENDING INTO OUR AREA. THE LOW LEVEL
MOISTURE AXIS IS ALIGNED ALONG THIS SURFACE PRESSURE FEATURE WITH
BACKGROUND VERTICAL MOTION SUPPLIED BY AGEOSTROPHIC CIRCULATION
UNDER THE SOUTH FLANK OF THE UPPER JET. THE RESULT IS CONTINUED
SUPPORT FOR ONGOING CONVECTION AND DEVELOPMENT OF ADDITIONAL SHOWERS
AND WEAKER STORMS NORTH OF THE SURFACE BOUNDARY. SINCE MIDNIGHT...
CONCERN HAS TRANSITIONED FROM SEVERE WEATHER POTENTIAL NEAR THE OHIO
BORDER TO EXCESSIVE RAINFALL THROUGH THE I-69 CORRIDOR...ALTHOUGH
INTENSITY OF STORMS WILL REMAIN STRONG NEAR THE OHIO BORDER WHERE
MID LEVEL LAPSE RATES ARE GREATEST. AT THE SAME TIME...EXPECT
COVERAGE OF SHOWERS AND STORMS WILL BE NUMEROUS FARTHER NORTH WITHIN
THE FRONTAL CIRCULATION IN THE 850-700 MB LAYER. BASED ON MODEL MEAN
RH TRENDS...THERE IS GOOD AGREEMENT THAT THIS CLUSTER OF CONVECTION
WILL MOVE EAST OF THE AREA AROUND NOON.
OTHER THAN A SLOW PROGRESSION OF THE SURFACE PRESSURE PATTERN...
THERE WILL NOT BE MUCH DIFFERENCE IN THE LARGE SCALE FEATURES
AFFECTING THE AREA DURING THE AFTERNOON COMPARED TO THE CURRENT
SETUP. THE CONSENSUS OF MODEL MSL PRESSURE SOLUTIONS PLACES THE
TRIPLE POINT OF THE OCCLUSION OVER NORTHERN LOWER MICHIGAN AROUND
18Z. SOUTHWEST FLOW RETURNING BEHIND THE MORNING CONVECTIVE PATTERN
WILL BE ADEQUATE TO MAINTAIN THUNDERSTORM POTENTIAL WITH SUFFICIENT
RECOVERY OF INSTABILITY. THE TIMING AND MAGNITUDE OF RECOVERY IS THE
MAIN UNCERTAINTY IN THE FORECAST AND SEVERE WEATHER POTENTIAL.
REASONABLE DOWNWARD ADJUSTMENTS TO THE LATEST NAM AND RAP OUTPUT
STILL OFFERS 0-1KM MLCAPE RECOVERING TO ABOUT 1500 J/KG MID TO LATE
AFTERNOON...BUT WITH MODEST MID LEVEL LAPSE RATES OF 6-7C/KM IN THE
700-500 MB LAYER AS THE EML SUPPORTING THE EARLY MORNING STORMS IS
DIRECTED INTO THE UPPER OHIO VALLEY. REMAINING IN PLACE WILL BE THE
SOUTHERN FRINGES OF DYNAMIC SUPPORT FROM THE UPPER WAVE OVER
NORTHERN ONTARIO...AND STRONG WESTERLY FLOW ALOFT OVER LOWER
MICHIGAN. MODEL SOUNDINGS INDICATE A SOLID STRAIGHT-LINE HODOGRAPH
ANCHORED BY 50-60 KNOTS OF FLOW AROUND 500 MB AND 0-6 KM BULK SHEAR
AROUND 50 KNOTS. DIFFERENT FROM YESTERDAY WILL BE A MORE VEERED LOW
LEVEL FLOW WHICH IS LESS FAVORABLE FOR TORNADOGENESIS...BUT THE
OVERALL PROFILE IS STILL SUPPORTIVE OF STORM SPLITS/SUPERCELL
ORGANIZATION EARLY IN THE CONVECTIVE CYCLE. PLAN TO CALL FOR
ISOLATED STORMS APPROACHING SEVERE LIMITS UNTIL SEVERE POTENTIAL CAN
BE REFINED WITH OBSERVATIONS AS THE DAY PROGRESSES. SHOWERS AND
WEAKER STORMS SHOULD OTHERWISE BECOME NUMEROUS BY LATER AFTERNOON
THROUGH THE EVENING BEFORE THE COLD FRONT SWEEPS EVERYTHING OUT OF
THE REGION AROUND MIDNIGHT.
LONG TERM...
COLD ADVECTION PATTERN EMBEDDED WITHIN CORRIDOR OF CYCLONIC
NORTHWEST FLOW ALOFT WILL PERSIST INTO FRIDAY MORNING. H85
TEMPERATURES ARE PROGGED TO FALL FROM 10C LATE TONIGHT TO 4C FRIDAY
MORNING. ONGOING COLD ADVECTION WILL ENSURE STEEP LOW-LEVEL LAPSE
RATES CAPABLE OF SUPPORTING EXPANSIVE AFTERNOON STRATOCU,
PARTICULARLY IN THE PRESENCE OF LOW AMPLITUDE DISTURBANCES RIPPLING
ALONG IN THE FLOW ALOFT. INFLUX OF THE COOLER AIRMASS COMBINED WITH
CLOUDS DEVELOPING DURING PEAK HEATING WILL LIMIT HIGHS TO THE
MID/UPPER 60S ON BOTH FRIDAY AND SATURDAY. HIGH AMPLITUDE RIDGE WILL
VERY GRADUALLY MIGRATE OVER THE GREAT LAKES THROUGH THE HOLIDAY
WEEKEND AS THE PATTERN SLOWS IN RESPONSE TO THE CLOSED LOW OVER THE
SOUTHWEST UNITED STATES. REBOUNDING THERMAL PROFILES WILL BE
ACCOMPANIED BY DEEP LAYER SUBSIDENCE, ADDING CONFIDENCE TO THE
FORECAST FOR A WARM AND MOSTLY SUNNY HOLIDAY WEEKEND. TEMPERATURES
WILL MODERATE FROM LOW/MID 70S ON SATURDAY TO THE LOW 80S BY MONDAY.
MARINE...
A WEAK COLD FRONT WILL SWING THROUGH THE CENTRAL GREAT LAKES THIS
AFTERNOON. BRISK NORTHWEST WINDS WILL THEN BUILD IN FOR TONIGHT AND
THURSDAY. ANY THUNDERSTORMS WHICH DEVELOP TONIGHT THROUGH TOMORROW
MAY BE STRONG TO SEVERE. LIGHT WINDS WILL RETURN FOR THE WEEKEND AS
HIGH PRESSURE SETTLES OVER THE AREA.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....BT
SHORT TERM...BT
LONG TERM....JVC
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
343 AM EDT WED MAY 21 2014
.SHORT TERM... TODAY AND TONIGHT
SURFACE AND MODEL ANALYSIS FIELDS PROVIDE A STRAIGHTFORWARD
DIAGNOSIS FOR ONGOING CONVECTIVE FORCING BUT THAT STILL LEAVES A
CHALLENGING FORECAST FOR WHAT MAY FOLLOW LATER TODAY THROUGH THIS
EVENING UNTIL THE SURFACE COLD FRONT PUSHES THROUGH THE REGION
CLOSER TO MIDNIGHT.
THE LARGE SCALE PATTERN IS ANCHORED BY A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WHICH HAS AN OCCLUDED FRONT EXTENDING INTO
A BROADER SURFACE WAVE OVER LOWER MICHIGAN RIPPLING ALONG THE MAIN
WARM/STATIONARY FRONT EXTENDING INTO OUR AREA. THE LOW LEVEL
MOISTURE AXIS IS ALIGNED ALONG THIS SURFACE PRESSURE FEATURE WITH
BACKGROUND VERTICAL MOTION SUPPLIED BY AGEOSTROPHIC CIRCULATION
UNDER THE SOUTH FLANK OF THE UPPER JET. THE RESULT IS CONTINUED
SUPPORT FOR ONGOING CONVECTION AND DEVELOPMENT OF ADDITIONAL SHOWERS
AND WEAKER STORMS NORTH OF THE SURFACE BOUNDARY. SINCE MIDNIGHT...
CONCERN HAS TRANSITIONED FROM SEVERE WEATHER POTENTIAL NEAR THE OHIO
BORDER TO EXCESSIVE RAINFALL THROUGH THE I-69 CORRIDOR...ALTHOUGH
INTENSITY OF STORMS WILL REMAIN STRONG NEAR THE OHIO BORDER WHERE
MID LEVEL LAPSE RATES ARE GREATEST. AT THE SAME TIME...EXPECT
COVERAGE OF SHOWERS AND STORMS WILL BE NUMEROUS FARTHER NORTH WITHIN
THE FRONTAL CIRCULATION IN THE 850-700 MB LAYER. BASED ON MODEL MEAN
RH TRENDS...THERE IS GOOD AGREEMENT THAT THIS CLUSTER OF CONVECTION
WILL MOVE EAST OF THE AREA AROUND NOON.
OTHER THAN A SLOW PROGRESSION OF THE SURFACE PRESSURE PATTERN...
THERE WILL NOT BE MUCH DIFFERENCE IN THE LARGE SCALE FEATURES
AFFECTING THE AREA DURING THE AFTERNOON COMPARED TO THE CURRENT
SETUP. THE CONSENSUS OF MODEL MSL PRESSURE SOLUTIONS PLACES THE
TRIPLE POINT OF THE OCCLUSION OVER NORTHERN LOWER MICHIGAN AROUND
18Z. SOUTHWEST FLOW RETURNING BEHIND THE MORNING CONVECTIVE PATTERN
WILL BE ADEQUATE TO MAINTAIN THUNDERSTORM POTENTIAL WITH SUFFICIENT
RECOVERY OF INSTABILITY. THE TIMING AND MAGNITUDE OF RECOVERY IS THE
MAIN UNCERTAINTY IN THE FORECAST AND SEVERE WEATHER POTENTIAL.
REASONABLE DOWNWARD ADJUSTMENTS TO THE LATEST NAM AND RAP OUTPUT
STILL OFFERS 0-1KM MLCAPE RECOVERING TO ABOUT 1500 J/KG MID TO LATE
AFTERNOON...BUT WITH MODEST MID LEVEL LAPSE RATES OF 6-7C/KM IN THE
700-500 MB LAYER AS THE EML SUPPORTING THE EARLY MORNING STORMS IS
DIRECTED INTO THE UPPER OHIO VALLEY. REMAINING IN PLACE WILL BE THE
SOUTHERN FRINGES OF DYNAMIC SUPPORT FROM THE UPPER WAVE OVER
NORTHERN ONTARIO...AND STRONG WESTERLY FLOW ALOFT OVER LOWER
MICHIGAN. MODEL SOUNDINGS INDICATE A SOLID STRAIGHT-LINE HODOGRAPH
ANCHORED BY 50-60 KNOTS OF FLOW AROUND 500 MB AND 0-6 KM BULK SHEAR
AROUND 50 KNOTS. DIFFERENT FROM YESTERDAY WILL BE A MORE VEERED LOW
LEVEL FLOW WHICH IS LESS FAVORABLE FOR TORNADOGENESIS...BUT THE
OVERALL PROFILE IS STILL SUPPORTIVE OF STORM SPLITS/SUPERCELL
ORGANIZATION EARLY IN THE CONVECTIVE CYCLE. PLAN TO CALL FOR
ISOLATED STORMS APPROACHING SEVERE LIMITS UNTIL SEVERE POTENTIAL CAN
BE REFINED WITH OBSERVATIONS AS THE DAY PROGRESSES. SHOWERS AND
WEAKER STORMS SHOULD OTHERWISE BECOME NUMEROUS BY LATER AFTERNOON
THROUGH THE EVENING BEFORE THE COLD FRONT SWEEPS EVERYTHING OUT OF
THE REGION AROUND MIDNIGHT.
&&
.LONG TERM...
COLD ADVECTION PATTERN EMBEDDED WITHIN CORRIDOR OF CYCLONIC
NORTHWEST FLOW ALOFT WILL PERSIST INTO FRIDAY MORNING. H85
TEMPERATURES ARE PROGGED TO FALL FROM 10C LATE TONIGHT TO 4C FRIDAY
MORNING. ONGOING COLD ADVECTION WILL ENSURE STEEP LOW-LEVEL LAPSE
RATES CAPABLE OF SUPPORTING EXPANSIVE AFTERNOON STRATOCU,
PARTICULARLY IN THE PRESENCE OF LOW AMPLITUDE DISTURBANCES RIPPLING
ALONG IN THE FLOW ALOFT. INFLUX OF THE COOLER AIRMASS COMBINED WITH
CLOUDS DEVELOPING DURING PEAK HEATING WILL LIMIT HIGHS TO THE
MID/UPPER 60S ON BOTH FRIDAY AND SATURDAY. HIGH AMPLITUDE RIDGE WILL
VERY GRADUALLY MIGRATE OVER THE GREAT LAKES THROUGH THE HOLIDAY
WEEKEND AS THE PATTERN SLOWS IN RESPONSE TO THE CLOSED LOW OVER THE
SOUTHWEST UNITED STATES. REBOUNDING THERMAL PROFILES WILL BE
ACCOMPANIED BY DEEP LAYER SUBSIDENCE, ADDING CONFIDENCE TO THE
FORECAST FOR A WARM AND MOSTLY SUNNY HOLIDAY WEEKEND. TEMPERATURES
WILL MODERATE FROM LOW/MID 70S ON SATURDAY TO THE LOW 80S BY MONDAY.
&&
.MARINE...
A WEAK COLD FRONT WILL SWING THROUGH THE CENTRAL GREAT LAKES THIS
AFTERNOON. BRISK NORTHWEST WINDS WILL THEN BUILD IN FOR TONIGHT AND
THURSDAY. ANY THUNDERSTORMS WHICH DEVELOP TONIGHT THROUGH TOMORROW
MAY BE STRONG TO SEVERE. LIGHT WINDS WILL RETURN FOR THE WEEKEND AS
HIGH PRESSURE SETTLES OVER THE AREA.
&&
.AVIATION...ISSUED 1225 AM EDT WED MAY 21 2014
//DISCUSSION...
SURFACE ANALYSIS INDICATES A WEAK WAVE OF LOW PRESSURE RIPPLING
ALONG THE WARM FRONT LEFT OVER FROM YESTERDAY. THIS WILL CONTINUE TO
SUPPORT THUNDERSTORM ACTIVITY OVER SW LOWER AND NORTHERN INDIANA
WHICH IS EXPECTED TO DEVELOP EASTWARD WITH ENOUGH CONFIDENCE TO
INCLUDE IN THE TERMINALS FROM PTK SOUTH THROUGH THE DTW AREA. WEAK
EASTERLY FLOW NORTH OF THE BOUNDARY COULD FUNNEL SOME IFR CONDITIONS
INTO MBS AND MVFR INTO FNT IN EITHER OR LOW CEILING AND FOG BY
SUNRISE. BEHIND TONIGHTS THUNDERSTORM ACTIVITY...ADDITIONAL SHOWERS
AND LOW CEILING WILL SPREAD ACROSS THE REGION AS THE WAVE OF LOW
PRESSURE WORKS ACROSS LOWER MICHIGAN DURING THE MORNING. STILL SOME
OPPORTUNITY FOR NEW THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON
SUBJECT TO SUFFICIENT SURFACE HEATING.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE FOR THUNDERSTORMS BETWEEN 04-07Z TONIGHT.
* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET AFTER 04Z TONIGHT
THROUGH MUCH OF WEDNESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...BT
LONG TERM....JVC
MARINE.......JVC
AVIATION.....MANN/BT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1225 AM EDT WED MAY 21 2014
.AVIATION...
//DISCUSSION...
SURFACE ANALYSIS INDICATES A WEAK WAVE OF LOW PRESSURE RIPPLING
ALONG THE WARM FRONT LEFT OVER FROM YESTERDAY. THIS WILL CONTINUE TO
SUPPORT THUNDERSTORM ACTIVITY OVER SW LOWER AND NORTHERN INDIANA
WHICH IS EXPECTED TO DEVELOP EASTWARD WITH ENOUGH CONFIDENCE TO
INCLUDE IN THE TERMINALS FROM PTK SOUTH THROUGH THE DTW AREA. WEAK
EASTERLY FLOW NORTH OF THE BOUNDARY COULD FUNNEL SOME IFR CONDITIONS
INTO MBS AND MVFR INTO FNT IN EITHER OR LOW CEILING AND FOG BY
SUNRISE. BEHIND TONIGHTS THUNDERSTORM ACTIVITY...ADDITIONAL SHOWERS
AND LOW CEILING WILL SPREAD ACROSS THE REGION AS THE WAVE OF LOW
PRESSURE WORKS ACROSS LOWER MICHIGAN DURING THE MORNING. STILL SOME
OPPORTUNITY FOR NEW THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON
SUBJECT TO SUFFICIENT SURFACE HEATING.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE FOR THUNDERSTORMS BETWEEN 04-07Z TONIGHT.
* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET AFTER 04Z TONIGHT
THROUGH MUCH OF WEDNESDAY.
&&
.PREV DISCUSSION...ISSUED 915 PM EDT TUE MAY 20 2014
UPDATE...
COMPOSITE SURFACE BOUNDARY EXTENDING FROM TORONTO THROUGH CHICAGO
INTO IOWA HAS IGNITED A FAIR AMOUNT OF DISCRETE CONVECTION THIS
EVENING. THE ACTIVITY OVER LOWER MICHIGAN HAS BEEN RESTRICTED TO A
SINGLE CELL RESPONSE CURRENTLY MOVING THROUGH OAKLAND AND MACOMB
COUNTIES. THE RESPONSE HAS BEEN FAR MORE IMPRESSIVE OVER NORTHERN
ILLINOIS ALONG THE PERIPHERY OF MUCH GREATER QUALITY INSTABILITY
/COMPARE KDVN AND KDTX RAOB/. AS THE BOUNDARY CONTINUES TO SETTLE
SOUTH SLOWLY DURING THE LATE EVENING HOURS...UPSTREAM CONVECTION
WILL ADVANCE IN A NARROW CORRIDOR OF MODERATE INSTABILITY AHEAD
OF THE BOUNDARY. STORMS HAVE YET TO GEL INTO AN ORGANIZED COMPLEX
AND WILL REQUIRE A LITTLE MORE SIMMER TIME TO FORM A COMMON COLD
POOL. MOREOVER...LATEST RADAR TRENDS SUGGEST PREFERENTIAL
DEVELOPMENT FAVORING A SOUTHWARD DRIFT. EXPECTING ANY ORGANIZATION
TO FAVOR A MOTION THAT KEEPS THE MOST ROBUST ACTIVITY ACROSS
NORTHERN INDIANA AND NORTHWEST OHIO DURING THE OVERNIGHT HOURS.
REGARDLESS...PLENTY OF INSTABILITY TO SUPPORT SOME SEMBLANCE OF
ELEVATED NOCTURNAL CONVECTION ACROSS METRO DETROIT SOUTH TO THE
BORDER. HOWEVER...GREATEST POTENTIAL FOR SEVERE IS BECOMING
BETTER ESTABLISHED SOUTH OF THE BORDER /SEE LATEST SPC SWOMCD/.
PREV DISCUSSION...ISSUED 345 PM EDT TUE MAY 20 2014
SHORT TERM... THROUGH TONIGHT
SHORT TERM CONCERNS STILL REVOLVE AROUND CONVECTIVE TRENDS AND
POTENTIAL FOR SEVERE WEATHER. FIRST...FOR THE REMAINDER OF THIS
AFTERNOON INTO THE EVENING. FAST ZONAL UPPER LEVEL FLOW IS OVER THE
UPPER MIDWEST BETWEEN A RIDGE OVER THE SOUTHERN PLAINS AND A TROUGH
OVER SOUTHERN MANITOBA/SOUTHWESTERN ONTARIO. 18Z SURFACE ANALYSIS
SHOWED A WARM FRONT ARCING SE INTO MICHIGAN FROM ROUGHLY NORTH OF
MUSKEGEON TO LAPEER AND THEN SOUTH TO AROUND MONROE. THE
NORTH/EASTWARD PROGRESS OF THE FRONT IS BEING HINDERED BY FLOW OFF
THE COOLER LAKES. TEMPS CONTINUE TO WARM INTO THE LOW/MID 70S SOUTH
OF THE FRONT WITH DEWPOINTS IN THE LOW 50S TO NEAR 60. SOME CUMULUS
IS DEVELOPING OVER SOUTHWESTERN LOWER IN THE LEE OF LAKE
MICHIGAN...BUT SO FAR IT IS SHALLOW. MIDLEVEL LAPSE RATES ARE FAIRLY
MEAGER BUT SHOULD INCREASE INTO THE EVENING. SOME MODEST SURFACE
BASED INSTABILITY MAY DEVELOP AS WE GET LATER INTO THE AFTERNOON AND
EVENING. DEEP LAYER SHEAR OF 35-50KT IS FAVORABLE FOR ORGANIZED
CONVECTION SHOULD ANYTHING DEVELOP...BUT THE LACK OF CLEAR FORCING
MECHANISMS AND GREATER INSTABILITY WILL KEEP POPS IN THE LOW CHANCE
RANGE THROUGH 00Z.
ANOTHER THREAT IS EXPECTED TO DEVELOP AFTER 04Z...BUT IT
IS FAR FROM CERTAIN. DISCRETE CELLS ARE EXPECTED TO DEVELOP OVER
NORTHERN ILLINOIS LATE THIS AFTERNOON. THESE STORMS MAY EVOLVE INTO
ONE OR MORE FORWARD-PROPAGATING QUICK-MOVING MCS...WHICH COULD BE
LONG-LIVED DUE TO CONTINUED STRONG DEEP-LAYER SHEAR AND APPRECIABLE
INSTABILITY. THIS SCENARIO IS SUPPORTED BY THE 16Z HRRR AND THE 12Z
NMM. THESE COMPLEXES WOULD PREFERENTIALLY MOVE TOWARD THE RESERVOIR
OF GREATER INSTABILITY...WHICH IS BETTER TO OUR SOUTH WHERE THE
GREATER MIDLEVEL LAPSE RATES WILL RESIDE. STILL...THE THREAT IS GOOD
ENOUGH TO INCLUDE A SLIGHT CHANCE OF SEVERE WEATHER FROM M-59 SOUTH
/WITH THE BEST CHANCES NEAR THE OHIO BORDER/ FROM AROUND 04-10Z.
DAMAGING WIND WOULD BE THE MAIN THREAT...WITH LARGE HAIL AND AN
ISOLATED TORNADO SECONDARY. HEAVY RAIN IS ALSO POSSIBLE AS PWATS
INCREASE TO 1.3-1.5 INCHES.
LONG TERM...
LARGE UPPER LEVEL LOW SLOWLY WORKING THROUGH ONTARIO
TOMORROW...DROPPING SOUTHEAST INTO NEW ENGLAND THURSDAY NIGHT INTO
FRIDAY WILL DELIVER A RESPECTABLE SHOT OF COOL AIR TO SOUTHEAST
MICHIGAN THURSDAY INTO FRIDAY...BEFORE TEMPERATURES QUICKLY MODERATE
OVER THE WEEKEND AS AMPLIFIED UPPER LEVEL RIDGE BUILDS INTO THE
GREAT LAKES REGION...LIKELY LEADING TO EVEN WARMER TEMPERATURES (80+
DEGREES) EARLY NEXT WEEK.
AS FAR AS TOMORROW GOES...THE FORECAST WILL BE IMPACTED WITH WHAT
OCCURS OVERNIGHT...AS POTENTIAL DEPARTING MCV MAY CAST
SHADOW/SUBSIDENCE WAKE THROUGH A GOOD PORTION OF THE DAY.
OTHERWISE...DO HAVE SHORTWAVE TROUGH AXIS EXTENDING FROM THE
PREVIOUS MENTIONED UPPER LEVEL LOW OVER ONTARIO...WHICH WILL CAUSE
SURFACE COLD FRONT TO SWING THROUGH DURING THE PEAK DIURNAL CYCLE.
STRONG WESTERLY JET (65 KNOTS AT 500 MB) CORE WILL BRING AN
INCREASED RISK OF DAMAGING WINDS IF THUNDERSTORMS ARE ABLE TO
DEVELOP DURING THE AFTERNOON HOURS. THE PROBLEM IS WE CAN NOT FULLY
COUNT ON A MORNING CAP/LULL...AND STORMS COULD EASILY DEVELOP
EARLIER IN THE DAY. DURING THE AFTERNOON HOURS...THE INCREASING
MIXING DEPTHS WE ACCELERATE THE WESTERLY DRYING OUT
PROCESS...LEADING TO QUESTIONS WITH THE AREAL COVERAGE OF THE
POTENTIAL STORMS DEVELOPING ALONG THE COLD FRONT...AS MAX
INSTABILITY LOOKS TO BE OVER THE NORTHERN OHIO VALLEY. WITH THAT
SAID...IT LOOKS FAIRLY LIKELY SOMETIME DURING THE 12 HOUR
WINDOW...NUMEROUS SHOWERS AND THUNDERSTORMS WILL OCCUR...AND
UNFORTUNATELY WILL CARRY GENERIC HIGH SCATTERED/LOW LIKELY POPS
THROUGH THE DAY...AS TONIGHT`S EVOLUTION WILL BE A ONE OF THE KEYS
FOR TOMORROWS WEATHER.
STRONG NORTHWEST FLOW WEDNESDAY NIGHT INTO THURSDAY...WITH 850 MB
TEMPS FALLING INTO THE MID SINGLE NUMBERS. THE CYCLONIC/COLD
ADVECTION AND STEEP LOW LEVEL LAPSE RATES SHOULD BE SUFFICIENT TO
GENERATE PLENTY OF CLOUDS DURING THE DAYTIME HOURS OF
THURSDAY...LIKELY CAPPING MAXES IN THE UPPER 60S TO AROUND 70
DEGREES. ANOTHER PIECE OF ENERGY ROTATING SOUTH THROUGH THE CENTRAL
GREAT LAKES ON FRIDAY SHOULD MAINTAIN THE COOLER TEMPERATURES AND
CONSIDERABLE CLOUDS DURING THE DAYTIME HOURS...AND EVEN SUFFICIENT
DIURNAL INSTABILITY/CAPES/CLOUD DEPTHS (4-12 KFT) TO POSSIBLY
PRODUCE ISOLATED LIGHT SHOWERS.
12Z EURO IS IN DECENT AGREEMENT WITH THE CANADIAN/GFS IN BUILDING
UPPER LEVEL RIDGE OVER THE CENTRAL GREAT LAKES ON
MONDAY...SUPPORTING HIGHS IN EXCESS OF 80 DEGREE WITH INCREASING
SOUTHWEST FLOW AND 850 MB TEMPS WARMING INTO THE MID TEENS INTO
TUESDAY.
MARINE...
INCREASED SOUTHEAST FLOW OVER OUTER SAGINAW BAY AND THE ADJACENT
NEARSHORE WATERS DUE TO THUNDERSTORMS TRACKING THROUGH THE AREA WILL
DIMINISH AS WARM FRONT WEAKENS TONIGHT. A STRONG COLD FRONT WILL
SWING THROUGH THE CENTRAL GREAT LAKES TOMORROW AFTERNOON...WITH
BRISK NORTHWEST WINDS FOLLOWING FOR WEDNESDAY NIGHT AND THURSDAY.
ANY THUNDERSTORMS WHICH DEVELOP TONIGHT THROUGH TOMORROW MAY BE
STRONG TO SEVERE. COOLER AND MORE STABLE AIRMASS WILL FILTER INTO
THE REGION THURSDAY AND FRIDAY...BUT ISOLATED SHOWERS ARE STILL
POSSIBLE. A LARGE UPPER LEVEL RIDGE BUILDING INTO THE GREAT LAKES
REGION OVER THE WEEKEND WILL LEAD TO WARMUP TEMPERATURES AND LIGHT
WINDS.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MANN/BT
UPDATE.......MANN
SHORT TERM...DT
LONG TERM....SF
MARINE.......SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DULUTH MN
627 PM CDT THU MAY 22 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 255 PM CDT THU MAY 22 2014
CLOUDS HAVE BEEN VERY SLOW TO DISSIPATE TODAY...HANGING TOUGH FROM
KINL TO KDLH TO KHYR AND KPBH. THE RAP HAS BEEN DOING A DECENT JOB
DEPICTING THESE CLOUDS. COLD TEMPS AND CYCLONIC FLOW ALOFT HAVE
CONTRIBUTED TO A FAVORABLE SET UP FOR THE CLOUDS.
THE CLOUDS HAVE BEEN SLOWLY DIMINISHING THIS AFTERNOON AND WITH
LOSS OF HEATING...WE EXPECT IT TO CONTINUE. THE RAP ALSO SHOWS THE
CLOUDS DIMINISHING THIS EVENING. THE HIGH WILL PASS OVER THE CWA
AND WINDS WILL BECOME LIGHT ALLOWING TEMPS TO COOL INTO THE MID
THIRTIES TO LOWER FORTIES. SOME OF THE COOLER LOCALES ACROSS THE
CWA MAY DROP TO NEAR FREEZING.
AS THE HIGH CONTINUES ITS SLOW EASTWARD TRACK FRIDAY...WINDS WILL COME
AROUND TO MORE SOUTHERLY FOR MOST AREAS. IT SHOULD BE WARMER WITH
MOST AREAS CLIMBING TO 69 TO 75. AREAS AROUND LAKE SUPERIOR WILL BE
COOLER WITH LIGHT ONSHORE WINDS EXPECTED. THERE SHOULD ALSO BE MORE
SUN AS UPPER LEVEL RIDGING AND WARMING TEMPS OCCUR.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 255 PM CDT THU MAY 22 2014
OVERALL SYNOPTIC SCALE PATTERN FEATURES A MID LVL RIDGE OVER NRN
PLAINS AND UPPER MIDWEST NEXT 5 TO 7 DAYS. WITHIN THAT REGIME THERE
IS SOME AGREEMENT AMONGST MED RANGE MDL SUITE THAT A PROGRESSIVE
SHORTWAVE TROF MAY DAMPEN RIDGE ENOUGH TO WARRANT AN EPISODE OF
PRECIP. AS MID LVL RIDGE MOVES INTO REGION THIS WEEKEND WIT WILL BE
ACCOMPANIED BY A BROAD PATTERN OF WARM ADVECTION IN THE LOW/MID
LAYERS. A PROGRESSIVELY MORE MOIST ATMOSPHERE WILL DEVELOP AND THERE
IS A CHC THAT SCT CONVECTION MAY OCCUR AS EARLY AS SAT AFTN OVER
WRN CWA. HOWEVER WILL ACCEPT MDL TREND TO SLOW DOWN ARRIVAL OF
SUFFICIENT MOISTURE AND START PRECIP POTENTIAL SAT NIGHT. GRADUAL
INCREASE IN POPS SUNDAY WITH HIGHEST PROB OCCURRING SUN NIGHT/EARLY
MONDAY AS LARGE SCALE ASCENT IS MAXIMIZED WITH PASSAGE OF SHORTWAVE
ALOFT. SFC HIGH WILL BUILD SOUTH BEHIND THE DEPARTING SHORTWAVE
MONDAY. SOME TIMING DIFFERENCES WITH REGARD TO HOW SOON THE PRECIP
MOVES SOUTH OF THE CWA. BEYOND THAT UNCERTAINTY INCREASES AS INITIAL
SFC BDRY MOVES WELL SOUTH OF REGION TUESDAY AND THEN POSSIBLY
RETREATS NORTH BY MIDWEEK. ALLBLEND SOLUTION GIVES POPS ACROSS SRN
CWA TUES/WED HOWEVER NOT CONFIDENT THAT ENOUGH MOISTURE IS EVIDENT.
WILL LET NEXT SHIFT SHIFT TO A DRIER PATTERN IF MDL TRENDS CONTINUE.
TEMPS REMAIN ABOVE NORMAL THROUGH PERIOD AS 50H PATTERN ADVERTISES
ANOMALOUS RIDGING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 626 PM CDT THU MAY 22 2014
VFR THROUGH THE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 41 70 46 75 / 0 0 0 10
INL 39 73 50 79 / 0 0 10 10
BRD 42 75 55 79 / 0 0 10 10
HYR 38 75 45 76 / 0 0 0 10
ASX 39 68 43 72 / 0 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MELDE
LONG TERM...CANNON
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS DULUTH MN
303 PM CDT WED MAY 21 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 302 PM CDT WED MAY 21 2014
CLOUDS HAVE BEEN VERY SLOW TO DIMINISH OVER THE NORTHLAND TODAY
UNDER COOL NORTHWESTERLY FLOW ALOFT. THEY ARE STARTING TO THIN TO
OUR SOUTHWEST...AND THAT TREND WILL CONTINUE OVERNIGHT. WE DID
INCREASE CLOUDS THIS EVENING FOR MOST AREAS...FOLLOWING CLOSE TO
THE RAP LOW LEVEL MOISTURE FIELDS. THE LATEST RAP ALSO SHOWS
CLOUDS HANGING IN FOR MUCH OF THE NIGHT OVER THE NORTHEAST HALF TO
TWO THIRDS OF THE CWA. WE WILL MONITOR CLOUD TRENDS TONIGHT AND
WE MAY NEED TO BEEF UP CLOUDS AND ADJUST LOWS UP.
WE BUMPED UP CLOUDS A BIT ON THURSDAY AND WENT WITH PARTLY CLOUDY
SKIES. WE THINK THERE COULD BE CLOUDS AROUND EARLY AND WE SHOULD
DEVELOP SOME CU THROUGH THE DAY. AT THE SURFACE...HIGH PRESSURE
WILL BE OVERHEAD BUT TEMPS WILL STILL BE COOL ALOFT.
HIGH PRESSURE WILL CONTINUE TO IMPACT THE REGION AND PROVIDE DRY
CONDITIONS INTO FRIDAY. TEMPERATURES WILL WARM FROM THE SIXTIES
THURSDAY INTO THE SEVENTIES FOR MOST AREAS ON FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 302 PM CDT WED MAY 21 2014
THE EXTENDED PERIOD FROM FRIDAY NIGHT THROUGH NEXT WEDNESDAY FINALLY
LOOKS TO BE A SUSTAINED PERIOD OF AT OR ABOVE NORMAL TEMPS ACROSS
MOST OF THE REGION. WHILE AREAS NEAR LAKE SUPERIOR WILL LIKELY SEE
RATHER ROBUST LAKE BREEZE FRONTS DURING THE MIDDAY TO EVENING HOURS
SAT-MON TIME FRAME..THE REMAINDER OF THE DULUTH CWA SHOULD SEE HIGH
TEMPS WELL INTO THE 70S..ALONG WITH DEWPOINTS REACHING INTO THE 60S
BY THE MON-WED TIME FRAME.
SURFACE AND MID LEVEL RIDGE AXIS SHOULD BE OVER THE CWA NEAR THE
BEGINNING OF THE PERIOD FRI NIGHT/SAT..BRINGING A COOL MORNING.
HOWEVER..RETURN SOUTH/SOUTHEAST FLOW SHOULD DEVELOP IN MOST AREAS BY
MIDDAY SAT..WITH BEST CHANCES FOR RAIN SHOWERS REMAINING TO OUR WEST
UNTIL LATER IN THE DAY. RATHER ROBUST DIFFERENTIAL HEATING SHOULD
RESULT IN A FAIRLY STRONG LK SUPERIOR LAKE BOUNDARY DURING THE
AFTERNOON..WITH HIGH TEMPS OCCURRING LATE MORNING TO EARLY AFTERNOON
IN THE FAVORED LAKE BREEZE LOCATIONS. GIVEN THAT LOW LEVEL FLOW WILL
LIKELY STILL HAVE SOME EASTERLY COMPONENT..THERE SEEMS TO BE
POTENTIAL FOR ANY LAKE BREEZE BOUNDARY TO PENETRATE RATHER FAR
INLAND BY LATE AFTERNOON SATURDAY..WITH SOME COOLING EFFECT POSSIBLY
NOTED AS FAR WEST AS THE GRAND RAPIDS/IRON RANGE/INTERIOR ARROWHEAD
AREAS BY EVENING.
CHANCES FOR SHOWERS/TSTORMS WILL INCREASE FROM WEST TO EAST LATE SAT
INTO MONDAY AS NORTHERN STREAM WAVE PUSHES A WEAK FRONT INTO THE NE
MN AREA..BEFORE THE FRONT STALLS AND/OR WASHES OUT EARLY NEXT WEEK.
THE LARGE SOUTHERN STREAM UPPER LOW TRAVERSING THE PLAINS STATES TO
OUR SOUTH DURING THIS TIME AND PRECIPITATION/DEEP CONVECTION
ASSOCIATED WITH IT MAY ACT TO LESSEN THE NORTHWARD LOW LEVEL
MOISTURE TRANSPORT. HOWEVER..SUFFICIENT MOISTURE IS EXPECTED TO BE
IN PLACE TO SUPPORT SOME SHOWERS/STORMS IN VICINITY OF THE LINGERING
BOUNDARY FROM SAT NIGHT INTO MONDAY. AT THIS TIME..IT APPEARS THAT
INSTABILITY AND ESPECIALLY WIND SHEAR/FLOW WILL BE TOO WEAK TO
SUPPORT MUCH IN THE WAY OF ANY SEVERE WEATHER POTENTIAL. AGAIN..WE
EXPECT A LK SUPERIOR LAKE BREEZE FRONT TO DEVELOP SUN-MON AS
WELL..RESULTING IN LATE MORNING/EARLY AFTERNOON HIGH TEMPS IN AREAS
NEAR THE LAKE.
BY MID WEEK..A RATHER SIGNIFICANT LARGE SCALE PATTERN SHIFT TO A
PACNW UPPER TROF AND BROAD WSW MID LEVEL FLOW FROM THE GREAT BASIN
TO MANITOBA/NW ONTARIO SHOULD RESULT IN THE BUILDING OF A LOW LEVEL
THERMAL RIDGE FROM THE DAKOTAS INTO NW MINNESOTA. WHILE THE BEST
FLOW AND SHEAR AS WELL AS INSTABILITY AXIS IS EXPECTED TO REMAIN TO
OUR WEST BASED ON CURRENT GUIDANCE..THERE WILL STILL BE POTENTIAL FOR
SOME ELEVATED STORMS WITHIN THE LOW LEVEL WARM/MOIST ADVECTIVE ZONE
JUST DOWNSTREAM FROM THE MAIN UPPER LEVEL RIDGE AXIS ACROSS THE
DULUTH CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1230 PM CDT WED MAY 21 2014
HIGH END IFR TO LOW END MVFR CONDITIONS AT INL WILL GRADUALLY
IMPROVE LATER THIS AFTERNOON. MVFR CONDITIONS AT HIB AND BRD WILL
BECOME VFR BY 22Z. DLH AND HYR SHOULD REMAIN VFR THROUGH THE TAF
PERIOD. SOME WIND GUSTS UP TO 20 KNOTS FROM THE NORTHWEST WILL BE
OVER THE TAF SITES THROUGH LATE AFTERNOON. INCLUDED VCSH AT
INL...HIB AND DLH FOR AN ISOLATED RAIN SHOWER THROUGH 0Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 42 65 43 69 / 10 0 0 0
INL 40 61 40 73 / 10 0 0 10
BRD 41 70 43 75 / 0 0 0 10
HYR 41 66 39 73 / 10 0 0 0
ASX 42 64 39 68 / 10 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MELDE
LONG TERM...MILLER
AVIATION...KK
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1008 AM CDT WED MAY 21 2014
.UPDATE...ANOTHER DRY AND WARM DAY IS IN STORE AS HIGH PRESSURE
RIDGING REMAINS IN CONTROL. HIGHS THIS AFTERNOON ARE EXPECTED TO
REACH THE UPPER 80S FOR MOST LOCATIONS. THE CURRENT FORECAST IS IN
GOOD SHAPE WITH NO CHANGES NEEDED. /27/
&&
.AVIATION...ALL TAF SITES EXPECT KGLH HAVE MIXED OUT THIS MORNING.
EXPECT THAT TO OCCUR AROUND 16Z LEAVING ALL SITES IN VFR CONDITIONS
THROUGH MOST OF THE FORECAST PERIOD. WILL HAVE TO WATCH FOR
STRATUS/FOG DEVELOPMENT AGAIN TOWARD 12Z THURSDAY. /SW/
&&
.PREV DISCUSSION... /ISSUED 331 AM CDT WED MAY 21 2014/
SHORT TERM...TODAY THROUGH THURSDAY NIGHT...SPRAWLING MID/UPPER
LEVEL ANTICYCLONE...CENTERED OVER THE LOWER MS VALLEY...CONTINUES TO
PROVIDE TRANQUIL WEATHER OVER THE FORECAST AREA AND THIS LOOKS TO
CONTINUE THROUGH THE SHORT TERM. AT THE SURFACE...RIDGE AXIS REMAINS
POSITIONED ALONG THE NORTHERN GULF COAST. LOW LEVEL FLOW ABOUT THIS
AXIS CONTINUES TO PROVIDE AN OPPORTUNITY FOR STRATUS/FOG DEVELOPMENT
THROUGH ISENTROPIC ASCENT AGAIN THIS MORNING AND TO SOME EXTENT
THURSDAY MORNING AS WELL.
THIS ISENTROPIC ASCENT CAN BE BEST SEEN IN THE 290-295K THETA LAYER
WITH BEST ZONE OF PRESSURE ADVECTION COUPLED WITH RISING THETA
SURFACES ALONG AND SOUTH OF HIGHWAY 84. ALREADY STRATUS STREAMERS
HAVE DEV LOPED FROM KMCB-K1R7. HRRR AND SREF DATA INDICATING
STRATUS/FOG AREA WILL CONTINUE TO FILL IN THIS MORNING OVER SOUTHERN
PORTIONS OF THE AREA...BUT...LIKE YESTERDAY MORNING...DISSIPATE
RAPIDLY WITHIN A COUPLE HOURS AFTER SUNRISE.
HIGH PRESSURE CENTER LOOKS TO BECOME SITUATED OVER SOUTH MS TONIGHT.
THIS WILL SERVE TO CHANGE OUR LOW LEVEL WINDS TO A MORE SOUTHWESTERLY
DIRECTION AND LESS FAVORABLE FOR STRATUS DEVELOPMENT BOTH THURSDAY
AND FRIDAY MORNINGS. ONLY THE EXTREME SW SECTION OF THE FORECAST AREA
WILL MAINTAIN ENOUGH OF A SOUTHERLY WIND COMPONENT TO SEE SOME
STRATUS THURSDAY MORNING.
LOOKING AT THE GFS MOS ENSEMBLE...STANDARD DEVIATIONS NEAR ZERO ARE
NOT OFFERING MUCH OF AN OPPORTUNITY TO IMPROVE ON THE TEMPERATURE
FORECAST. AS THE SURFACE HIGH BECOMES CENTERED OVER SOUTH
MS...SIGNIFICANT LOW LEVEL MOISTURE RETURN WILL DIMINISH ALLOWING
FOR CONTINUED LARGE DIURNAL RANGES AND MAX TEMPS TO BEGIN INCHING UP
A LITTLE EACH DAY AS MOS IS INDICATING./26/
LONG TERM...FRIDAY THROUGH NEXT WEDNESDAY...WARM AND DRY FOR THE
MEMORIAL DAY WEEKEND WITH SLIGHTLY ABOVE NORMAL TEMPERATURES BY ~5F
DEGREES. RAIN CHANCES WILL INCREASE EACH DAY STARTING NEXT MONDAY
INTO MID WEEK AS A MID-LEVEL DISTURBANCE SLOWLY APPROACHES THE
REGION.
OVERALL CONUS PATTERN LATE WEEK INTO THE HOLIDAY WEEKEND WILL
FEATURE A MID/UPPER LEVEL TROUGH BEGINNING TO CUT-OFF OVER THE
DESERT SW AS RIDGING CONTINUES OVER THE SE WITH A SHARP S/WV TROUGH
PIVOTING ACROSS GREAT LAKES INTO THE MID ATLANTIC. THE MID ATLANTIC
TROUGH WILL ACT TO BRING A NW/SE ORIENTED WEAK DENSITY/CONVERGENCE
BOUNDARY ACROSS N/NE MS INTO AL OVER THE WEEKEND. DESPITE THIS
LOW-LVL FOCUS AND SOME HINT OF EMBEDDED IMPULSES WITHIN THE BACKSIDE
NW FLOW...PWATS OF 1.2-1.3"...HIGH LCL INVERTED "V" SOUNDINGS...AND
MASS FIELDS SUGGESTIVE OF LIMITED CONVECTION IF ANY...HAVE KEPT WEATHER
WORDING OUT OF GRIDS THIS PACKAGE. A ROGUE SHOWER CAN NOT BE
COMPLETELY RULED OUT FOR THE NE CORNER THOUGH AND WILL MONITOR
TRENDS.
FOR MON-WED NEXT WEEK...OPS GFS AND EC ARE IN DECENT AGREEMENT WITH
CUT-OFF LOW SLOWLY PROGRESSING EAST ACROSS THE PLAINS TOWARDS THE
MID TO LOWER MS VALLEY BY MID WEEK. AS THIS FEATURE APPROACHES...
RAIN/TSTORM CHANCES WILL INCREASE WITH SOME LINGERING ACTIVITY DURING
THE OVERNIGHT HOURS TUES INTO WED WITH GREATER COVERAGE WED AFTN.
FOR WEATHER ELEMENTS...MEX LOWS WERE RAISED 1-4F NEXT WEEK TO ALIGN TOWARDS
RAW EC/GFS DEWPOINTS. MEX POPS WERE BUMPED UP SLIGHTLY TUES-WED. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 89 63 90 63 / 0 0 0 0
MERIDIAN 89 60 90 60 / 0 0 0 0
VICKSBURG 87 61 88 59 / 0 0 0 0
HATTIESBURG 88 62 90 62 / 0 0 0 0
NATCHEZ 87 62 86 63 / 0 0 0 0
GREENVILLE 88 65 89 65 / 0 0 2 2
GREENWOOD 88 63 89 62 / 0 0 2 2
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON MS
331 AM CDT WED MAY 21 2014
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT...SPRAWLING MID/UPPER
LEVEL ANTICYCLONE...CENTERED OVER THE LOWER MS VALLEY...CONTINUES TO
PROVIDE TRANQUIL WEATHER OVER THE FORECAST AREA AND THIS LOOKS TO
CONTINUE THROUGH THE SHORT TERM. AT THE SURFACE...RIDGE AXIS REMAINS
POSITIONED ALONG THE NORTHERN GULF COAST. LOW LEVEL FLOW ABOUT THIS
AXIS CONTINUES TO PROVIDE AN OPPORTUNITY FOR STRATUS/FOG DEVELOPMENT
THROUGH ISENTROPIC ASCENT AGAIN THIS MORNING AND TO SOME EXTENT
THURSDAY MORNING AS WELL.
THIS ISENTROPIC ASCENT CAN BE BEST SEEN IN THE 290-295K THETA LAYER
WITH BEST ZONE OF PRESSURE ADVECTION COUPLED WITH RISING THETA
SURFACES ALONG AND SOUTH OF HIGHWAY 84. ALREADY STRATUS STREAMERS
HAVE DEVLOPED FROM KMCB-K1R7. HRRR AND SREF DATA INDICATING
STRATUS/FOG AREA WILL CONTINUE TO FILL IN THIS MORNING OVER SOUTHERN
PORTIONS OF THE AREA...BUT...LIKE YESTERDAY MORNING...DISSIPATE
RAPIDLY WITHIN A COUPLE HOURS AFTER SUNRISE.
HIGH PRESSURE CENTER LOOKS TO BECOME SITUATED OVER SOUTH MS TONIGHT.
THIS WILL SERVE TO CHANGE OUR LOW LEVEL WINDS TO A MORE SOUTHWESTERLY
DIRECTION AND LESS FAVORABLE FOR STRATUS DEVELOPMENT BOTH THURSDAY
AND FRIDAY MORNINGS. ONLY THE EXTREME SW SECTION OF THE FORECAST AREA
WILL MAINTAIN ENOUGH OF A SOUTHERLY WIND COMPONENT TO SEE SOME
STRATUS THURSDAY MORNING.
LOOKING AT THE GFS MOS ENSEMBLE...STANDARD DEVIATIONS NEAR ZERO ARE
NOT OFFERING MUCH OF AN OPPORTUNITY TO IMPROVE ON THE TEMPERATURE
FORECAST. AS THE SURFACE HIGH BECOMES CENTERED OVER SOUTH
MS...SIGNIFICANT LOW LEVEL MOISTURE RETURN WILL DIMINISH ALLOWING
FOR CONTINUED LARGE DIURNAL RANGES AND MAX TEMPS TO BEGIN INCHING UP
A LITTLE EACH DAY AS MOS IS INDICATING./26/
.LONG TERM...FRIDAY THROUGH NEXT WEDNESDAY...WARM AND DRY FOR THE
MEMORIAL DAY WEEKEND WITH SLIGHTLY ABOVE NORMAL TEMPERATURES BY ~5F
DEGREES. RAIN CHANCES WILL INCREASE EACH DAY STARTING NEXT MONDAY
INTO MID WEEK AS A MID-LEVEL DISTURBANCE SLOWLY APPROACHES THE
REGION.
OVERALL CONUS PATTERN LATE WEEK INTO THE HOLIDAY WEEKEND WILL
FEATURE A MID/UPPER LEVEL TROUGH BEGINNING TO CUT-OFF OVER THE
DESERT SW AS RIDGING CONTINUES OVER THE SE WITH A SHARP S/WV TROUGH
PIVOTING ACROSS GREAT LAKES INTO THE MID ATLANTIC. THE MID ATLANTIC
TROUGH WILL ACT TO BRING A NW/SE ORIENTED WEAK DENSITY/CONVERGENCE
BOUNDARY ACROSS N/NE MS INTO AL OVER THE WEEKEND. DESPITE THIS
LOW-LVL FOCUS AND SOME HINT OF EMBEDDED IMPULSES WITHIN THE BACKSIDE
NW FLOW...PWATS OF 1.2-1.3"...HIGH LCL INVERTED "V" SOUNDINGS...AND
MASS FIELDS SUGGESTIVE OF LIMITED CONVECTION IF ANY...HAVE KEPT WEATHER
WORDING OUT OF GRIDS THIS PACKAGE. A ROGUE SHOWER CAN NOT BE
COMPLETELY RULED OUT FOR THE NE CORNER THOUGH AND WILL MONITOR
TRENDS.
FOR MON-WED NEXT WEEK...OPS GFS AND EC ARE IN DECENT AGREEMENT WITH
CUT-OFF LOW SLOWLY PROGRESSING EAST ACROSS THE PLAINS TOWARDS THE
MID TO LOWER MS VALLEY BY MID WEEK. AS THIS FEATURE APPROACHES...
RAIN/TSTORM CHANCES WILL INCREASE WITH SOME LINGERING ACTIVITY DURING
THE OVERNIGHT HOURS TUES INTO WED WITH GREATER COVERAGE WED AFTN.
FOR WEATHER ELEMENTS...MEX LOWS WERE RAISED 1-4F NEXT WEEK TO ALIGN TOWARDS
RAW EC/GFS DEWPOINTS. MEX POPS WERE BUMPED UP SLIGHTLY TUES-WED./ALLEN/
&&
.AVIATION...STRATUS/FOG THIS MORNING WILL ALLOW FOR IFR CONDITIONS
UNTIL AROUND 14Z FOR KJAN/KHKS/KMEI/KHBG. THEREAFTER...VFR
CONDITIONS WILL PREVAIL./26/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 89 63 90 63 / 0 0 0 0
MERIDIAN 89 60 90 60 / 0 0 0 0
VICKSBURG 87 61 88 59 / 0 0 0 0
HATTIESBURG 88 62 90 62 / 0 0 0 0
NATCHEZ 87 62 86 63 / 0 0 0 0
GREENVILLE 88 65 89 65 / 0 0 2 2
GREENWOOD 88 63 89 62 / 0 0 2 2
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
341 PM CDT Wed May 21 2014
.SHORT TERM: (Through Late Tonight)
Issued at 1256 PM CDT Wed May 21 2014
Cold front extended from just north of UIN southwest through MCI.
This front will move southward through our forecast area tonight, and
should extend from west central MO southeast through southern IL by
12z Thursday. The cap should break late this afternoon with
scattered convection developing along this front. The HRRR model
has most of the convection across northeast MO and west central IL
early this evening, then shifts it southward with most of the
convection from around COU east through the St Louis metro area to
Vandalia and Salem IL by midnight. Some of these storms may be
severe due to very unstable conditions late this afternoon and this
evening with CAPEs of 2000-3000 J/Kg and surface LI values as low as
-10 south of the cold front. Low-mid level shear will also be
relatively strong with 500 mb wind speeds of up to 50 kts due to a
500 mb wind max moving through the Great Lakes region.
GKS
.LONG TERM: (Thursday through Next Wednesday)
Issued at 340 PM CDT Wed May 21 2014
The cold front will continue to sag slowly southward as a surface
ridge shifts eastward from the northern Plains into the Great Lakes
region. At least scattered convection is expected along and just
behind this front as weak shortwaves move east southeastward through
our area over the mid-upper level ridge centered over the Gulf Coast
states. The best coverage of convection should be across central
and southeast MO Thursday and Thursday night as the front becomes
more nw to se oriented. The ECMWF model appears to be a little too
far north with its qpf from Thursday afternoon into Friday morning.
Cooler and drier air will advect into the region behind the cold
front, particularly across northeast MO and west central IL.
The mid-upper level low now over NV will move slowly through the
southwest US. Weak shortwaves will eject northeastward from this
feature and bring more convection mainly to the western portion of
our forecast area Saturday and Saturday night with the upper level
ridge along with the surface ridge centered over the Great Lakes and
Ohio Valley regions keeping the eastern portion of our forecast area
dry. The mid-upper level low will eventually move into the Plains
by Monday. The models have varying solutions after this with the
ECMWF model moving it into MO by Tuesday, while the GFS model
weakens it and has it passing south of our area. With this model
uncertainty will just include chance pops for early next week,
although there may be more widespread showers/storms for Monday
night and Tuesday. Always difficult to forecast the exact path,
strength and speed of upper level lows coming out of the southwest
US.
GKS
&&
.AVIATION: (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1214 PM CDT Wed May 21 2014
Cold front over northwestern Missouri will continue to sag
southward today into this evening, reaching KUIN by around 03Z,
then pushing into KCOU and KSTL metro TAF sites by 05Z. Unstable
airmass ahead of the front may fuel scattered thunderstorms this
afternoon into early evening, however coverage is uncertain so
will address in the TAFS with several hours of VCTS and update
frequently as the situation becomes more clear. Any storms should
diminish overnight with loss of strong daytime heating. VFR
conditions expected otherwise on Wednesday with winds veering to
northeast.
Specifics for KSTL: Scattered thunderstorms may form near
approaching cold front from 23Z until around 05Z. Coverage is
uncertain however and may be rather limited, so handled in the TAF
with a VCTS. Otherwise expect VFR conditions. Surface winds will
back from west this afternoon through north with frontal passage
around 05Z, then become northeast.
Browning
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
308 PM CDT Wed May 21 2014
.SHORT TERM...(This Evening through Thursday Night)
Issued at 305 PM CDT WED MAY 21 2014
The focus through the period continues to be on thunderstorms
chances. For this afternoon the frontal boundary currently slowly
moving south across portions of the NRN CWA should serve as the
focus for isolated to scattered storms. Dprog/Dt of the HRRR paints
a narrow zone of storms along the front forming by 5 to 6 pm in our
CWA, then they move east and clear the CWA by around 9 or 10 pm.
Latest ACARS soundings out of KMCI depict the CAP slowly eroding so
confidence is rather high we should see a few storms along the
front. Given the large CAPE and modest shear profiles large hail
and damaging winds will be the main threats.
Late overnight tonight a large complex of storms may work into the
CWA from the west/southwest. At this time the better chances of
seeing storms appears to favor the WRN and NRN areas of the CWA.
The complex of storms should be weakening as they move in, thus the
overnight SVR potential is rather low.
Tomorrow most of the CWA will be north of the surface front so high
temps should be back down to near normal... mid to upper 70s with
mid 80s across our far SRN zones. Precip wise is a tough call depending
on how long any overnight activity lingers into the daylight morning
hours, residual cloud debris and degree of instability. So for now
just have low chance pops through tomorrow into tomorrow evening
given a lack upper level forcing.
.LONG TERM...(Friday through Wednesday)
Issued at 305 PM CDT WED MAY 21 2014
A rather messy short to medium range forecast through the Memorial
Day holiday and into much of next week. Why? The development of
the cutoff low across the southwestern United States that will
slowly crawl eastward into early next week. This low is expected to
pull increasing amounts of low-mid level moisture northward into the
Plains which will interact with a stalled frontal boundary in the
region.
By Friday morning, precipitation chances will increase briefly as a
secondary shortwave drops through the Great Lakes and a brief window
of warm advection commences overnight. This upper trough will push surface
high pressure into the region, and force the stalled front well
south of the area, potentially forcing precip south and east of the
CWA Friday afternoon and evening.
It`s hard to get too specific on forecast details through this
weekend and into Monday due to shortwave timing issues. The weekend
shouldn`t be a washout, but we`ll have to carry scattered PoP
wording through Monday.
Medium range models are all over the place in the eventual track of
the upper low through the area through Thursday. ECMWF/GEM produces
fairly widespread rains for Monday and Tuesday with a northern track,
GFS dives the ejecting low too far south to produce widespread rains,
but more scattered activity. Ensemble approach provides little
benefit, with a substantial spread in solutions. For now, have to
continue to include PoPs through much of the extended.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1208 PM CDT WED MAY 21 2014
VFR CIGS and VIS are planned through the period at all three
terminals. The issue will be whether scattered storms develop near
the terminals late this afternoon along a cold front that is
currently sliding south into the region. CIGS/VIS may dip down to
MVFR if a storm does pass over a terminal, but those conditions should
not last long. Late tonight more organized storms may move in from
the west approaching the terminals before clearing out by mid-
morning. Will try to time out better the overnight activity with the
00Z TAF issuance as confidence may be greater on location and
coverage by that time.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Pietrycha
LONG TERM...Dux
AVIATION...Pietrycha
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
101 PM CDT Wed May 21 2014
.SHORT TERM: (Through Late Tonight)
Issued at 1256 PM CDT Wed May 21 2014
Cold front extended from just north of UIN southwest through MCI.
This front will move southward through our forecast area tonight, and
should extend from west central MO southeast through southern IL by
12z Thursday. The cap should break late this afternoon with
scattered convection developing along this front. The HRRR model
has most of the convection across northeast MO and west central IL
early this evening, then shifts it southward with most of the
convection from around COU east through the St Louis metro area to
Vandalia and Salem IL by midnight. Some of these storms may be
severe due to very unstable conditions late this afternoon and this
evening with CAPEs of 2000-3000 J/Kg and surface LI values as low as
-10 south of the cold front. Low-mid level shear will also be
relatively strong with 500 mb wind speeds of up to 50 kts due to a
500 mb wind max moving through the Great Lakes region.
GKS
.LONG TERM: (Tonight through Tuesday)
Issued at 315 AM CDT Wed May 21 2014
Expect very slow southward progress of the boundary until tonight
and tomorrow when a 1020-1025 hPa surface high slides from Canada
into the western Great Lakes, pushing the front farther to the
south and southwest. At first glance, environmental parameters for
Thu look similar to Wed: H7-H5 lapse rates of 6.5-7 deg C/km and
40-50 kts of 0-6 km shear. However, the higher shear values are
much less widespread on Thu and are not as favorably located
relative to the position of the boundary. If the models are
correct in advancing the front into southwest MO by Thu afternoon,
then the overall thunderstorm coverage across the LSX CWA would
probably be lower on Thu afternoon compared to Wed, and the chance
for widespread severe thunderstorms would also be lower. The best
chance for thunderstorms would be across the western part of the
CWA, closer to the boundary and to the juicier moisture pooled
along and south of it.
The boundary becomes reoriented but remains over the region
through the weekend, eventually lifting back northeastward as a
warm front on Sat/Sun. Several vorticity maxima are forecast to
move across the region during this time and may interact with the
front to produce periods of showers and thunderstorms. Models are
in broad agreement that a large closed low pressure system over
the desert southwest will lift into the plains and then move
eastward across MO/IL early next week, but some placement/timing
differences remain in the 00z GFS/ECMWF. Additional periods of
SHRA/TSRA are expected with this system, but it would not be
surprising if the preferred timing for the system`s passage across
MO/IL changes a few times over the next several days.
Kanofsky
&&
.AVIATION: (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1214 PM CDT Wed May 21 2014
Cold front over northwestern Missouri will continue to sag
southward today into this evening, reaching KUIN by around 03Z,
then pushing into KCOU and KSTL metro TAF sites by 05Z. Unstable
airmass ahead of the front may fuel scattered thunderstorms this
afternoon into early evening, however coverage is uncertain so
will address in the TAFS with several hours of VCTS and update
frequently as the situation becomes more clear. Any storms should
diminish overnight with loss of strong daytime heating. VFR
conditions expected otherwise on Wednesday with winds veering to
northeast.
Specifics for KSTL: Scattered thunderstorms may form near
approaching cold front from 23Z until around 05Z. Coverage is
uncertain however and may be rather limited, so handled in the TAF
with a VCTS. Otherwise expect VFR conditions. Surface winds will
back from west this afternoon through north with frontal passage
around 05Z, then become northeast.
Browning
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
654 PM CDT THU MAY 22 2014
.SYNOPSIS...
ISSUED AT 342 PM CDT THU MAY 22 2014
THE H5 PATTERN REMAINS LARGELY UNCHANGED FROM 24 HOURS
AGO WITH LITTLE OR NO HT CHANGES NOTED ACROSS THE CONUS. HIGH
PRESSURE WAS ANCHORED OVER SERN ALABAMA...WITH LOW PRESSURE OVER THE
CANADIAN MARITIMES AND A CLOSED LOW OVER THE CALIFORNIA DESERT. WV
IMAGERY THIS AFTERNOON HAS A DECENT SHORTWAVE LIFTING NORTH ACROSS
THE SRN ROCKIES FROM NRN NEW MEXICO INTO SRN COLORADO. ANOTHER
SHORTWAVE WAS LIFTING ACROSS EASTERN UT AND WESTERN WYOMING AS OF
MIDDAY. FURTHER EAST...THE REMNANTS OF A CONVECTIVE COMPLEX WHICH
LIFTED ACROSS SRN NEBRASKA AND NORTHERN KS OVERNIGHT...HAS LIFTED
EAST INTO THE MID MISSISSIPPI VALLEY. AT THE SURFACE...A STATIONARY
FRONT EXTENDED FROM NEAR SAINT LOUIS MO...WSW INTO THE OK
PANHANDLE...THEN NNWD ALONG THE FRONT RANGE OF COLORADO AND WYOMING.
FURTHER NORTH...HIGH PRESSURE HAS MOVED FROM THE DAKOTAS INTO THE
UPPER MISSISSIPPI VALLEY THIS MORNING...WHICH HAS SHIFTED WINDS TO A
MORE SERLY DIRECTION THIS MORNING...AND HAS BEGUN TO PUSH ADDITIONAL
LOW LEVL MOISTURE INTO WESTERN AND NORTH CENTRAL NEBRASKA. AS OF 2
PM CDT...UNDER PARTLY CLOUDY SKIES...TEMPERATURES RANGED FROM 73 TO
75 DEGREES ACROSS WESTERN AND NORTH CENTRAL NEBRASKA.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 342 PM CDT THU MAY 22 2014
UPPER LEVEL RIDGE REMAINS PARKED ACROSS MUCH OF THE CENTRAL UNITED
STATES ONCE AGAIN TODAY...EFFECTIVELY IMPEDING THE UPPER FLOW OVER
MUCH OF THE CONUS. WITH THIS BLOCKED FLOW...THE UPPER LEVEL LOW OFF
TO OUR WEST HAS NOT MADE SIGNIFICANT EASTWARD PROGRESS OVER THE PAST
24 HOURS...BUT HAS SLIPPED SOUTH INTO SOUTHERN CALI/NORTHERN BAJA.
THIS SOUTHWARD SHIFT HAS ALLOWED FOR A SLIGHT AMPLIFICATION OF THE
RIDGE INTO THE WESTERN HIGH PLAINS...WHICH IS NOW PROVIDING FOR A
LIGHTER...BUT MORE DIRECT NORTHERLY COMPONENT OF THE STEERING LEVEL
WINDS. AS HAS BEEN THE CASE THE PAST FEW DAYS...THE CONVECTION
ALLOWING MODELS ARE GENERATING CONVECTION NEAR THE FRONT
RANGE/PALMER DIVIDE AND ALONG CONVERGENCE ASSOCIATED WITH A MODEST
DCVZ. WITH TIME THE MODELS INDICATE ADDITIONAL DEVELOPMENT FURTHER
EAST ON THE HIGH PLAINS AS THE ATMOSPHERE CONTINUES TO DESTABILIZE
IN A WEAK LOW LEVEL UPSLOPE REGIME. THIS ACTIVITY IS SHOWN TO SPILL
ONTO THE PLAINS OF FAR SOUTHWEST AND WESTERN NEBRASKA THIS EVENING
DESPITE THE GREATER NORTHERLY TRAJECTORY. THE HRRR HAS HANDLED THE
PAST FEW DAYS WELL ALONG THE FRONT RANGE AND ADJACENT PLAINS...THUS
THE FORECAST THROUGH INTO THE OVERNIGHT WAS TRENDED IN THAT
DIRECTION. WITH THAT...GENERALLY CUT BACK THE EXTENT AND
PROBABILITY OF PRECIP FOR MUCH OF THE CWA...SAVE FOR OUR FAR
SOUTHWEST WHERE THE RAP13 AND HRRR SUGGEST THE PRESENCE OF STORMS
AFTER 03Z. SHOULD STORMS HOLD TOGETHER INTO SOUTHWEST NEBRASKA THIS
EVENING THERE IS SOME SUPPORT OF ELEVATED INSTABILITY WHICH WOULD
PROMOTE A STRONG TO SEVERE STORM OR TWO. OTHERWISE INCREASING
CLOUDS OVERNIGHT WILL HELP KEEP TEMPERATURES MILD...WIDESPREAD LOWS
IN THE MID 50S SEEMS PLAUSIBLE.
FRIDAY...SURFACE HIGH PRESSURE WILL BUILD EAST TOWARD THE GREAT
LAKES REGION...ALLOWING FOR A GREATER SOUTHERLY COMPONENT TO THE
LOWER TROPOSPHERIC FLOW ACROSS THE CWA. WITH INCREASING LOW LEVEL
MOISTURE...SHOWERS AND THUNDERSTORMS WILL FORM WITH A LIFTING
FRONTAL BOUNDARY BY EARLY AFTERNOON. THE CAPPING INVERSION IS WEAK
FRIDAY...SO STORM COVERAGE IS EXPECTED TO BE MORE NUMEROUS...BUT
SEVERE COVERAGE SHOULD BE LIMITED AS NUMEROUS UPDRAFTS COMPETE AND
THE UPPER STEERING FLOW REMAINS WEAK UNDER RIDGING ALOFT.
TEMPERATURES WILL BE MODERATED BY EXPECTED OVERCAST SKIES AND THE
POTENTIAL OF SHOWERS. HIGHS IN THE 70S FOR MOST LOCATIONS SEEMS ON
PAR.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM CDT THU MAY 22 2014
FRIDAY NIGHT THROUGH MONDAY...FORECASTING CHALLENGES IN
THE MID RANGE CONTINUE TO BE PRECIPITATION CHANCES...AS A PERSISTENT
TROUGH OF LOW PRESSURE ALOFT CREEPS TOWARD THE CENTRAL AND SOUTHERN
PLAINS INTO THE WEEKEND. ONGOING CONVECTION ACROSS NERN COLORADO AND
WESTERN KS...WILL MAKE ITS WAY INTO SOUTHWESTERN AND WESTERN
NEBRASKA FRIDAY EVENING. AS HAS BEEN THE CASE OVER THE PAST SEVERAL
NIGHTS...THIS ACTIVITY IS EXPECTED TO WEAKEN AS IT MOVES EAST INTO
MUCH WEAKER SHEAR ACROSS WESTERN NEBRASKA. CHANCE POPS WERE
CONTINUED IN THE WEST AND SWRN CWA FRIDAY EVENING WITH POPS FALLING
SHARPLY IN THE CENTRAL AND EAST. EVEN WITH DECENT MOISTURE...THE
LACK OF A DECENT LOW LEVEL JET AND WEAK DYNAMICS SHOULD LIMIT THE
COVERAGE OF PCPN FRIDAY NIGHT. MIN TEMPS SATURDAY MORNING...ARE
EXPECTED TO BE MILD IN THE MID AND UPPER 50S GIVEN THE INCREASED LOW
LEVEL MOISTURE...AND EXPECTED LOW LEVEL CLOUD COVER. LOW CLOUDINESS
WILL LINGER INTO SATURDAY WITH THE MODELS INDICATING A CONTINUATION
OF PERSISTENT LOW LEVEL CLOUDINESS INTO SATURDAY AFTERNOON. WITH
AFTERNOON HEATING AND A WEAK CAP IN PLACE...AM EXPECTING SHOWERS AND
THUNDERSTORMS TO DEVELOP...ESPECIALLY OVER SWRN NEBRASKA WHERE
CAPE/S REACH 1000 TO 1500 J/KG SAT AFTERNOON. THIS ACTIVITY IS
EXPECTED TO BE FAIRLY DISORGANIZED THOUGH AS DEEP SHEAR IS VERY WEAK
AT 15 KTS OR LESS SAT AFTN AND SAT EVE. ON SATURDAY NIGHT...THE
FRONTAL BOUNDARY WILL LIFT NORTH INTO SOUTH DAKOTA. BY
SUNDAY...SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS SOUTH DAKOTA
INVOF OF THE FRONT...AIDED BY A SHORTWAVE TROUGH WHICH TRAVERSES THE
NRN TIER OF STATES SUN AFTERNOON. FURTHER SOUTH...SHRAS AND
THUNDERSTORMS WILL DEVELOP ACROSS THE HIGH PLAINS OF WESTERN KANSAS
SOUTH TO THE TX PANHANDLE. IN ADVANCE OF THE MAIN UPPER LEVEL TROUGH
OF LOW PRESSURE. DECIDED TO DROP POPS DOWN A BIT FOR
SUNDAY...PARTICULARLY IN SWRN NEBRASKA...WITH THE BEST FORCING OVER
WRN KS...AND NORTH OF THE FORECAST AREA INVOF THE FRONT. BETTER
CHANCES FOR PCPN WILL ARRIVE IN ALL AREAS SUNDAY NIGHT INTO EARLY
MONDAY AS THE FRONT DROPS SOUTH INTO THE FORECAST AREA.
MONDAY NIGHT THROUGH THURSDAY...THE UPPER LEVEL TROUGH OF LOW
PRESSURE WILL LIFT EAST ACROSS THE SOUTHERN PLAINS MONDAY INTO
MONDAY NIGHT...SHIFTING THE THREAT FOR PCPN EAST. TEMPERATURES WILL
WARM WEDNESDAY AND THURSDAY THANKS TO WEAK LOW AMPLITUDE RIDGING
ACROSS THE ROCKIES. NO DOUBT...WE MAY SEE SOME ISOLATED
THUNDERSTORMS WEDNESDAY AND THURSDAY AHEAD OF AN APPROACHING TROUGH
OF LOW PRESSURE. WITH GUIDANCE POPS WELL BELOW CLIMO...WILL LEAVE
CONDS DRY FOR NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 644 PM CDT THU MAY 22 2014
VISUAL FLIGHT RULES EXPECTED THROUGH MIDNIGHT AT TERMINALS KLBF
AND KVTN. SOUTHEAST WINDS ARE DRAWING MOISTURE NORTHWEST WHERE BEYOND
MIDNIGHT BOUNDARY LAYER MOISTURE IS FORECAST TO DEEPEN ACROSS
SOUTHWEST NEBRASKA. THE MODELS DIFFER IN THE APPROACH WITH LOW
CLOUDS FORMING AOB 2500 FEET...BEYOND 06Z. THEN AREAS OF FOG MAY
ALSO DEVELOP AND INCLUDED IN THE KLBF TERMINAL BEYOND 09Z THEN CLOUDS
LIFTING...OR DISSIPATING BEYOND 15Z TO VISUAL FLIGHT RULES.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...JACOBS
LONG TERM...JACOBS
AVIATION...KECK
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
322 PM CDT WED MAY 21 2014
.SYNOPSIS...
ISSUED AT 322 PM CDT WED MAY 21 2014
A FAIRLY STAGNANT UPPER LEVEL PATTERN WAS NOTED ACROSS
THE LOWER 48 THIS MORNING. WITH THE EXCEPTION OF FLAGSTAFF AZ...NO
UA SITES HAD HT FALLS OR RISES IN EXCESS OF 50 METERS. THE MAIN
FEATURES OF NOTE ACROSS THE LOWER 48 WERE HIGH PRESSURE OVER THE
MISSISSIPPI DELTA...A STRONG SHORTWAVE OFF THE COAST OF MAINE...AND
A CLOSED LOW OVER NEVADA. A WEAK JET STREAK AROUND 50 KTS WAS NOTED
FROM NRN AZ INTO WESTERN COLORADO. A COUPLE OF WEAK SHORTWAVES WERE
NOTED EARLY THIS AFTERNOON ALONG THE WESTERN SLOPES OF
COLORADO...AND OVER EASTERN NEW MEXICO. THESE TWO DISTURBANCES HAVE
LED TO INCREASED CLOUD COVER OVER WESTERN COLORADO...WYOMING...AS
WELL AS EASTERN NEW MEXICO AND THE TX PANHANDLE. AT THE
SURFACE...HIGH PRESSURE HAS PUSHED INTO THE DAKOTAS AND NORTHERN
NEBRASKA THIS AFTERNOON...FORCING A FRONTAL BOUNDARY INTO THE TEXAS
PANHANDLE. THIS BOUNDARY THEN WINDS TO THE WEST NORTHWEST ALONG THE
FRONT RANGE OF COLORADO AND WYOMING. WITH EASTERLY AND NORTHEASTERLY
WINDS...UNDER CLEAR TO PARTLY CLOUDY SKIES...2 PM CDT TEMPERATURES
RANGED FROM 65 AT AINSWORTH...TO 75 AT IMPERIAL.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 322 PM CDT WED MAY 21 2014
WEAK PV ANOMALY MOVING NWD ALONG THE FRONT RANGE OF CO PER WV
IMAGERY SHOULD CONTINUE TO GENERATE SFC PRESSURE FALLS IN THE LEE OF
THE PALMER DIVIDE AND ENHANCE EXISTING UPSLOPE FLOW TO INITIATE TSRA
ALONG THE HIGHER TERRAIN INITIALLY...WITH ORGANIZED CONVECTIVE
MOVEMENT EXPECTED TO BE NORTHEASTWARD INTO WESTERN AND SW NEB. SHORT
RANGE MODEL FCST SOUNDINGS INDICATE SOME REMAINING...THOUGH
ELEVATED...INSTABILITY OVERNIGHT. HOWEVER MOISTURE IS NOT OVERLY
IMPRESSIVE FURTHER NORTHEAST INTO CENTAL NEBR SINCE NRLY/NERLY FLOW
AT THE SFC ADVECTING ONLY MID TO UPPER 40S DEW POINTS. IN THE
ABSENCE OF A WELL DEFINED LLJ CONVECTION WILL HAVE A DIFFICULT TIME
BEING SUSTAINED INTO CENTRAL NEBR...MUCH LIKE LAST FEW NIGHTS.
HOWEVER...SINCE ORGANIZED CONVECTION WILL LIKELY BE MORE WIDESPREAD
IT MAY HAVE BETTER POTENTIAL. SHORT RANGE MODELS CURRENTLY ARE IN
DISAGREEMENT WITH THIS. HRRR ENSEMBLE UPDRAFT HELICITY SUGGESTS
ORGANIZATION OF INDIVIDUAL UPDRAFTS WOULD WEAKEN AS ANY REMAINING
STORMS MOVE INTO SW NEB. HARD TO ASSESS POTENTIAL FOR SVR...MODELS
SOUNDINGS SHOW SOME CAPE IN THE LOWER RANGE OF THE HAIL GROWTH
REGION...STILL BETTER POPS ARE INCLUDED TONIGHT MOST AREAS THAN PREV
NIGHTS.
WOULD EXPECT A SIMILAR SCENARIO THURSDAY MORNING AS WITH LAST COUPLE
OF MORNINGS IN THAT CONVECTIVE DEBRIS WILL REMAIN ACROSS SOME
PORTIONS OF THE CWA...THOUGH PINPOINTING WHERE IS DIFFICULT.
THEREFORE POPS INCLUDED PRIMARILY WHERE ELEVATED INSTABILITY
RESIDES. UPPER LOW OVER THE SOUTHWEST MOVES LITTLE BUT PIVOTS TO
BECOME SLIGHTLY NEGATIVELY TILTED THURS AFTERNOON. AS A RESULT WINDS
SHOULD BECOME MORE SOUTHEASTERLY AND ADVECT BETTER MOISTURE BACK
INTO THE AREA. FEEL MORE ORGANIZED CONVECTION THURSDAY SHOULD AGAIN
ENTER WESTERN NEB AFTER 00Z FRI. HIGHS WILL BE TEMPERED SOME BY
CLOUD COVER EARLY...BUT SHOULD RECOVER IN THE AFTERNOON MUCH LIKE
TODAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 322 PM CDT WED MAY 21 2014
FOR THURSDAY NIGHT THROUGH SATURDAY...PRECIPITATION CHANCES CONTINUE
TO BE THE MAIN FORECASTING CHALLENGE IN THE MID RANGE PERIODS. LIKE
THIS AFTERNOON...THUNDERSTORMS ARE EXPECTED TO BE ONGOING BY
THURSDAY EVENING OVER NERN COLORADO AND NWRN KS INVOF OF A STALLED
OUT FRONTAL BOUNDARY. WEAK SOUTHERLY AND SSWRLY STEERING WINDS WILL
LIFT THIS ACTIVITY NORTH INTO WESTERN NEBRASKA THURSDAY EVENING. AS
HAS BEEN THE CASE OVER THE PAST COUPLE OF NIGHTS...THIS ACTIVITY HAS
WEAKENED SUBSTANTIALLY AS IT MOVES INTO THE FORECAST AREA FROM THE
WEST AND SOUTHWEST. HOWEVER...TOMORROW NIGHT INTO FRIDAY...LOW LEVEL
WINDS WILL SHIFT MORE TO THE SOUTHEAST AS SURFACE HIGH PRESSURE
LIFTS INTO THE UPPER MISSISSIPPI VALLEY THIS SHIFT IN THE WIND
DIRECTION WILL SERVE TWO PURPOSES...A INCREASE LOW LEVEL
MOISTURE-BRINGING DEW POINTS BACK INTO THE 50S AND B...LEAD TO A 20
TO 30 KT LOW LEVEL JET THURSDAY NIGHT...WHICH WILL HELP TO SUSTAIN
CONVECTION INTO THE LATE NIGHT HOURS. WITH THE FLOW BEING FAIRLY
WEAK IN THE MID LEVELS AND DEEP MID LAYER INSTABILITY BEING FAIRLY
MEAGER...DECIDED TO LEAVE POPS IN THE 30 TO 50 PERCENT RANGE AS
COVERAGE IS EXPECTED TO REMAIN SCATTERED. ON FRIDAY...THE FRONTAL
BOUNDARY WILL LIFT NORTH INTO SOUTHWESTERN AND WESTERN
NEBRASKA...ALLOWING SHOWERS AND THUNDERSTORMS TO LINGER DURING THE
DAYTIME HOURS. CAPPING ON FRIDAY IS WEAK PER THE LATEST NAM AND GFS
SOLNS...SO AFTERNOON HEATING DURING THE DAYTIME HOURS...WILL QUICKLY
LEAD TO ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT. IN
ADDITION...FCST QPF`S ARE EXPECTED TO BE THE HIGHEST FRIDAY/FRIDAY
NIGHT...GIVEN THE EXPECTED WEAK STEERING WINDS AND PWATS OF 1.25 TO
1.50 INCHES. WITH RESPECT TO SEVERE POTENTIAL FRIDAY...AT THIS
TIME...THE SEVERE THREAT FOR FRIDAY APPEARS TO BE MARGINAL GIVEN THE
WEAK MID LEVEL FLOW...ALONG WITH LITTLE OR NO CAP...WHICH WILL
PRODUCE COMPETING UPDRAFTS AND DISORGANIZED CLUSTERS OF STORMS. ON
SATURDAY...THE FRONTAL BOUNDARY WILL LIFT EAST INTO CENTRAL PORTIONS
OF THE FORECAST AREA...FORCED BY THE APPROACH OF THE UPPER LEVEL LOW
AND TROUGH...WHICH WILL REACH THE FOUR CORNERS BY 00Z SUNDAY. THOUGH
PCPN CHANCES REMAIN POSSIBLE ACROSS THE ENTIRE FORECAST AREA...THE
HIGHEST POPS SATURDAY AND SATURDAY NIGHT WILL BE CARRIED ALONG AND
NORTH OF THE FRONT...IMPACTING MAINLY NORTHERN AND EASTERN PORTIONS
OF THE FORECAST AREA.
SUNDAY THROUGH WEDNESDAY...THE UPPER LEVEL LOW WILL BEGIN TO FILL ON
SUNDAY AS IT LIFTS EAST INTO THE SRN PLAINS. PCPN CHANCES WILL
LINGER SUNDAY INTO MONDAY...BEFORE THE SYSTEM EXITS THE SOUTHERN
PLAINS INTO THE ARKLATEX. DRIER AND WARMER CONDITIONS ARE EXPECTED
TUESDAY INTO WEDNESDAY AS A POSITIVELY TILTED RIDGE EXTENDS FROM THE
DESERT SOUTHWEST INTO NRN MINNESOTA. HIGHS WILL RETURN TO THE LOWER
80S FROM THE MIDDLE 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1253 PM CDT WED MAY 21 2014
AVIATION FORECAST CONCERNS DEAL WITH CONFIDENCE ON CONVECTIVE
DEVELOPMENT LATE THIS AFTERNOON INTO THE EVENING. VSBL SAT PICS
AND OBS SHOW FRONT HAS PUSHED UP AGAINST THE FRONT RANGE AND
UPSLOPE FLOW HAS RESULTED ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA. AC CLOUD COVER ACROSS THE MODDLE OF THE STATE A RESULT
OF PREVIOUS WEAK CONVECTION...MUCH THE SAME AS TUESDAY. THIS
CONVECTIVE DEBRIS WILL CONTINUE TO DRIFT NORTH DURING THE
AFTERNOON. CURRENT THOUGHT IS FOR CONVECTION TO DEVELOP CLOSE TO
THE DENVER FRONT RANGE AREA AS WELL AS NEAR THE LARAMIE RANGE IN
SOUTHEAST WY. SHORT RANGE AND CONVECTION ALLOWING MODELS SUGGEST
THAT FRONT RANGE CONVECTION WILL BE MOST ROBUST THROUGH THE
AFTERNOON AND AN ORGANIZED CLUSTER OF TSRA SHOULD MOVE NORTHEAST
INTO SOUTHWEST NEB AFTER 00Z. RAP13 SHOWING DECENT ELEVATED
INSTABILITY THROUGH MIDNIGHT TO MAINTAIN CONVECTION SOUTH OF I80
CORRIDOR...BUT CONFIDENCE IS LOW TO MAINTAIN STORMS THE FURTHER
NORTH IT GETS. HAVE INCLUDED A PREVAILING GROUP FOR -TSRA IN THE
LBF TAF...BUT ONLY PROB30 GROUP IN FOR KVTN.
SHOULD BE CONVECTIVE DEBRIS AGAIN TMRW MORNING...SIMILAR TO THE
LAST TWO DAYS. STRATUS SHOULD BE CONFINED TO WEST OF KVTN-KLBF
LINE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...JWS
LONG TERM...CLB
AVIATION...JWS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1256 AM CDT WED MAY 21 2014
.SYNOPSIS...
ISSUED AT 312 PM CDT TUE MAY 20 2014
A FAIRLY ACTIVE H5 PATTERN HAS DEVELOPED ACROSS THE
CONUS OVER THE PREVIOUS 24 HOURS. LOW PRESSURE WAS ANCHORED OFF THE
COAST OF MAINE...WITH ANOTHER LOW OVER NORTHERN PORTIONS OF THE
CENTRAL VALLEY OF CALIFORNIA. ANOTHER LOW WAS PRESENT OVER THE
ALASKA PANHANDLE WITH ANOTHER LOW OVER NORTHERN PORTIONS OF THE
NORTHWEST TERRITORIES OF CANADA. CLOSER TO THE CENTRAL CONUS...A
NICE SHORTWAVE TROUGH WAS NOTED OVER SWRN MANITOBA. A 50+KT JET
STREAK EXTENDED ACROSS NRN WYOMING INTO SOUTH DAKOTA AND CENTRAL
MINNESOTA THIS MORNING. THIS FEATURE HAS LED TO THE DEVELOPMENT OF
SOME LIGHT RAIN SHOWERS ACROSS NORTHERN NEBRASKA AND SRN SOUTH
DAKOTA. THIS ACTIVITY HAS REMAINED VERY LIGHT THIS MORNING WITH ONLY
TRACE AMOUNTS TO A FEW HUNDREDTHS OF AN INCH REPORTED. AT THE
SURFACE...A TROUGH OF LOW PRESSURE EXTENDED FROM SERN MONTANA INTO
NERN COLORADO. FURTHER EAST...A COLD FRONT EXTENDED FROM FAR SWRN
NEBRASKA INTO THE SOUTHERN TEXAS PANHANDLE. TEMPERATURES SOUTH OF
THIS FEATURE WERE IN THE MID 80S TO 90S. WEST AND NORTH OF THE
FRONT...READINGS WERE IN THE 70S TO LOWER 80S. AS OF 2 PM
CDT...TEMPERATURES ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA...RANGED FROM 73 AT VALENTINE...TO 83 AT BROKEN BOW.
&&
.UPDATE...
ISSUED AT 807 PM CDT TUE MAY 20 2014
UPDATE TO THE FORECAST TO INCLUDE SEVERE WORDING. PLEASE REFER TO
WCN 162 FOR FURTHER DETAILS CONCERNING THE WATCH. CURRENTLY
WATCHING TWO AREAS OF CONVECTION...FIRST ACROSS THE WESTERN
PANHANDLE...AND THE SECOND IN NORTHEASTERN COLORADO. CONVECTION
ALLOWING MODELS INDICATE THAT THESE STORMS WILL CONTINUE
EASTWARD...POSSIBLY IMPACTING SOUTHWESTERN AND WESTERN PORTIONS OF
THE CWA THIS EVENING/OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 312 PM CDT TUE MAY 20 2014
ALTOCUMULUS AND SPRINKLES BISECTING THE LBF CWA A RESULT OF REMNANTS
OF EARLIER CONVECTION AND WEAK MID LEVEL FORCING IN ASSOCIATION WITH
MID LEVEL INSTABILITY. SUBSEQUENT MID LEVEL FRONTOGENESIS HAS
DEVELOPED ACCORDING TO THE RAP FURTHER SOUTHEAST IS GENERATING SOME
ADDITIONAL CLOUD COVER ACROSS THE FAR EASTERN PORTION OF THE AREA.
FURTHER WEST...CONVECTION IS DEVELOPING NEAR THE LARAMIE RANGE IN WY
VERY SIMILAR TO THE WAY CONVECTION ALLOWING MODELS HAVE BEEN
SUGGESTING WITH EACH RUN. THE HRRR HAS THIS HANDLED WELL AND IN THE
ABSENCE OF SIGNIFICANT LARGE SCALE FORCING...THIS CONVECTION IS
PROGGED TO REMAIN ISOLATED AND DOES HAVE SOME POTENTIAL TO RETAIN
SUPERCELL STRUCTURE AS IT MOVES EAST INTO THE PANHANDLE THIS
EVENING...AGAIN ACCORDING TO THE HRRR AND ITS ENSEMBLE OF UPDRAFT
HELICITY. SHOULD THIS CLUSTER OF STORMS HOLD TOGETHER TONIGHT THERE
IS SOME SUPPORT IN THE SHORT RANGE MODELS FOR ELEVATED INSTABILITY
IN THE PANHANDLE. FURTHER SOUTH INTO SOUTHWEST NEB...SOME CONVECTION
DEVELOPING NEAR THE CO FRONT RANGE AND MODELS KEEP THIS PROGRESSING
EWD AS WELL SO PRECIP CHANCES ADDED TO THE SOUTHWEST OVERNIGHT.
HOWEVER...CONFIDENCE IN THIS SCENARIO IS ONLY MODERATE TO MAINTAIN
ITS STRUCTURE INTO THE SW DUE TO A LACK OF A LOW LEVEL JET.
OTHERWISE...LOW TEMPS IN THE UPPER 40S TO LOW 50S LOOKS GOOD BASED
ON LOW LEVEL MOISTURE PROFILE BEING MAINTAINED OVERNIGHT.
UPPER LEVEL RIDGE BUILDS INTO THE CENTRAL PLAINS AS THE SOUTHWESTERN
STATES UPPER LOW SLOWLY MOVES EWD. MAY BE SOME CONVECTIVE DEBRIS
ONCE AGAIN WED MORNING ESPECIALLY ACROSS WRN NEB. IN ADDITION...NAM
SUGGESTS POTENTIAL FOR STRATUS ALONG AND JUST EAST OF THE FRONTAL
POSITION IN FAVORED AREA OF UPSLOPE FLOW. THEN UPPER PV ANOMALY TO
MOVE INTO THE CENTRAL ROCKIES TOMORROW WHICH SHOULD ALLOW FOR A MUCH
BROADER COVERAGE OF CONVECTION AS THE UPPER FORCING SERVES TO
ENHANCE CONVERGENCE ALONG THE FRONT WHICH WILL BE LOCATED FROM NW KS
IN TO SERN WY. THIS DEVELOPMENT SHOULD BE DIURNALLY DRIVEN AND MAY
BE LIMITED DEPENDING ON ULTIMATE DEVELOPMENT OF STRATUS IN THE WEST.
TEMPS SHOULD BE COOLER WED THOUGH MODELS HAVE BEEN A LITTLE TOO COOL
IN THE SOUTH THE LAST COUPLE OF DAYS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 312 PM CDT TUE MAY 20 2014
WEDNESDAY NIGHT THROUGH TUESDAY...THE MAIN FORECAST
CHALLENGE WILL BE PRECIPITATION CHANCES IN THE MID RANGE AND
EXTENDED FORECAST. A PERSISTENT UPPER LEVEL TROUGH OF LOW PRESSURE
WILL REMAIN ANCHORED ACROSS THE WESTERN CONUS. PERSISTENT LOW LEVEL
MOISTURE WILL FLOW INTO WESTERN AND NORTH CENTRAL NEBRASKA THANKS TO
LOW LEVEL EASTERLY WINDS.
FOR WEDNESDAY NIGHT THROUGH FRIDAY...WEDNESDAY NIGHT...STRONG TO
SEVERE STORMS ARE EXPECTED TO BE ONGOING ACROSS NERN COLORADO AND
NWRN KS INVOF OF THE SURFACE FRONTAL BOUNDARY. WITH SSWRLY STEERING
WINDS CONTINUING ACROSS THE HIGH PLAINS...ACTIVITY WILL LIFT NWD
INTO THE FORECAST AREA DURING THE EVENING HRS. THERE WILL REMAIN A
LARGE HAIL THREAT MAINLY ACROSS FAR SWRN NEBRASKA AND THE SERN
NEBRASKA PANHANDLE WHICH WILL BE IN CLOSER PROXIMITY TO THE FRONTAL
BOUNDARY. FARTHER NORTH...HAIL SIZE SHOULD DECREASE ACROSS THE
WESTERN SANDHILLS AND I80 CORRIDOR...HOWEVER SMALL HAIL WILL REMAIN
A THREAT GIVEN THE DEGREE OF ELEVATED INSTABILITY EXPECTED
OVERNIGHT. BOTH THE GFS AND NAM SOLNS THIS MORNING...ARE INDICATIVE
OF MCS DEVELOPMENT WEDS EVENING...WHICH WILL TRAVERSE THE CWA
OVERNIGHT. THIS SEEMS PLAUSIBLE GIVEN THE 30 TO 40 KT H85 WINDS
ACROSS THE SOUTHERN AND CENTRAL CWA OVERNIGHT WEDS NIGHT. INHERITED
FORECAST HAD POPS IN THE 30 TO 50 PERCENT RANGE FROM NORTH TO SOUTH
WEDS NIGHT WHICH REMAINS ON TRACK GIVEN THE LATEST STATISTICAL
GUIDANCE. A SIMILAR CONVECTIVE SETUP WILL COMMENCE FOR LATE THURSDAY
INTO THURSDAY NIGHT. A FRONTAL BOUNDARY WILL BE STALLED OUT OVER
NORTHEASTERN COLORADO AND NWRN KS. WITH HEATING AND THE ARRIVAL OF AN
UPPER LEVEL SHORTWAVE...THUNDERSTORMS WILL INITIATE DURING THE LATE
AFTERNOON HRS INVOF THE FRONT. THERE ARE SOME MODEL DIFFERENCES IN
THE LOCATION OF THE FRONTAL BOUNDARY THURSDAY AFTERNOON WITH THE NAM
SOLN BEING THE FARTHEST SOUTH. WITH MCS DEVELOPMENT PROBABLE
TOMORROW NIGHT...JUST WHERE THIS BOUNDARY WILL LIE DOWN THURSDAY
WILL BE HARD TO PINPOINT...AS WILL BE THE SEVERE THREAT.
HOWEVER...ANOTHER ROUND OF SCATTERED THUNDERSTORMS IS POSSIBLE
THURSDAY NIGHT AS ACTIVITY ALONG THE FRONT LIFTS NORTH INTO THE
FORECAST AREA. FAVORABLE CONDITIONS...BOTH ALOFT AND AT THE SURFACE
FOR PRECIPITATION...WILL CONTINUE INTO FRIDAY. PERSISTENT SWRLY FLOW
ALOFT...A FRONTAL BOUNDARY ACROSS SWRN NEBRASKA AND EASTERLY AND
SERLY WINDS IN THE BOUNDARY LAYER ARE EXPECTED FRIDAY INTO FRIDAY
NIGHT. THE THREAT FOR SEVERE STORMS FRIDAY AFTERNOON AND FRIDAY
NIGHT WILL HINGE ON THE LOCATION OF THE SURFACE FRONTAL
BOUNDARY...WHICH ATTM IS EXPECTED TO LIE EITHER OVER SWRN NEBRASKA
OR OFF TO THE SW IN NERN COLORADO AND NWRN KS. LIKE WEDNESDAY AND
THURSDAY...SCATTERED THUNDERSTORMS WILL LIFT NORTH AND
NORTHEAST...FROM THE FRONTAL BOUNDARY INTO WESTERN AND NORTH CENTRAL
NEBRASKA FRIDAY EVENING AND FRIDAY NIGHT AND CHANCE POPS WERE
CONTINUED.
FRIDAY NIGHT THROUGH TUESDAY...AN UPPER LEVEL TROUGH WILL PERSIST
ACROSS THE INTERMOUNTAIN WEST FRIDAY NIGHT THROUGH SUNDAY
NIGHT...BEFORE LIFTING ACROSS THE CENTRAL PLAINS ON MONDAY. THE
THREAT FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE
WEEKEND...MAINLY DURING THE LATE AFTERNOON AND EVENING HOURS AS
ABUNDANT LOW LEVEL MOISTURE REMAINS IN PLACE ACROSS THE FORECAST
AREA. ON MONDAY AND MONDAY NIGHT...THE MAIN UPPER LEVEL LOW WILL
LIFT NORTHEAST INTO THE CENTRAL PLAINS...TRACKING INTO THE LOWER
MISSOURI VALLEY ON TUESDAY. PRECIPITATION CHANCES WILL CONTINUE INTO
MONDAY...WITH DRIER CONDS EXPECTED MONDAY NIGHT INTO TUESDAY. HIGHS
WILL GENERALLY BE IN THE 70S...WITH 80S POSSIBLE NEXT
TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1257 AM CDT WED MAY 21 2014
FOR THE KVTN AND KLBF 06Z TAFS...SHOWERS WITH THE OCCASIONAL STORM
WILL CONTINUE TO WORK EAST NORTHEAST ACROSS THE EASTERN PANHANDLE
AND ADJACENT SAND HILLS REGION OF WESTERN NEBRASKA EARLY THIS
MORNING. THIS ACTIVITY SHOULD PERSIST INTO THE PRE-DAWN HOURS WITH
ADDITIONAL CONVECTIVE DEVELOPMENT NOTED FROM REGIONAL RADARS OFF THE
HIGH PLAINS OF EASTERN WYOMING AND COLORADO. IF A STORM WERE TO
PASS OVER A TERMINAL...THEN BRIEF MVFR CONDITIONS WOULD BE
POSSIBLE. LATEST GUIDANCE FROM CONVECTIVE ALLOWING MODELS INDICATE
HOWEVER THAT THIS ACTIVITY SHOULD NOT IMPACT EITHER KVTN OR KLBF.
OTHERWISE STORMS ARE POSSIBLE ONCE AGAIN LATE IN THE TAF
PERIOD...ONCE AGAIN MAINLY ACROSS WESTERN AND SOUTHWEST NEBRASKA.
ATTM CONFIDENCE IS NOT ENOUGH FOR A MENTION IN THE OFFICIAL TAF
FORECAST.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JACOBS
SYNOPSIS...CLB
SHORT TERM...JWS
LONG TERM...CLB
AVIATION...POWER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
330 PM PDT WED MAY 21 2014
.SYNOPSIS...A LOW PRESSURE SYSTEM WILL CIRCULATE OVER SOUTHERN
NEVADA AND SURROUNDING AREAS THROUGH FRIDAY PRODUCING ISOLATED TO
SCATTERED SHOWERS AND A FEW THUNDERSTORMS. THE SYSTEM WILL FINALLY
MOVE AWAY TO THE EAST SATURDAY...WITH RAIN CHANCES DIMINISHING AND
TEMPERATURES QUICKLY CLIMBING OVER THE HOLIDAY WEEKEND.
&&
.SHORT TERM...THROUGH FRIDAY NIGHT...THE CIRCULATION CENTER OF THE
CUTOFF LOW HAS REMAINED OVER CENTRAL NYE COUNTY THROUGH THE DAY BUT
IT WILL QUICKLY DIVE DOWN OVER SOUTHERN CALIFORNIA TONIGHT. THIS IS
DUE TO ENERGY ROTATING DOWN THE WEST SIDE OF THE LOW WHICH WAS
AIDING IN PRODUCING A BAND OF CONSOLIDATED SHOWERS OVER THE
SOUTHWEST PART OF INYO COUNTY. THE 18Z NAM AND HRRR INDICATE THESE
SHOWERS WILL PUSH DOWN THROUGH NORTHWEST SAN BERNARDINO COUNTY THIS
EVENING AND A THUNDERSTORM OR TWO WILL ALSO BE POSSIBLE. SHOWERS
WILL DIMINISH AFTER 06Z AS THE LOW CENTER MOVES TOWARD THE SOUTHERN
CALIFORNIA COAST. MODELS ARE IN GOOD AGREEMENT THAT THE SYSTEM WILL
STRADDLE THE MEXICO BORDER AS IT SLOWLY CHURNS TOWARD THE EAST
THROUGH FRIDAY NIGHT. THIS SCENARIO WILL KEEP THE LIMITED MOISTURE
WITH THE SYSTEM MAINLY WEST OF LAS VEGAS THURSDAY. AS THE LOW CENTER
MOVES INTO SOUTHWEST ARIZONA FRIDAY AND FRIDAY NIGHT...WRAP AROUND
MOISTURE WILL BE PULLED DOWN THROUGH SOUTHERN NEVADA AND NORTHWEST
ARIZONA. SHOWERS SHOULD BE CONFINED PRIMARILY TO THE MOUNTAINS.
.LONG TERM...SATURDAY THROUGH TUESDAY.
MEMORIAL DAY WEEKEND IS LOOKING PRETTY TOASTY WITH MODEL CONSENSUS
SHOWING HIGH PRESSURE MOVING OVER THE AREA DURING THE WEEKEND.
YESTERDAY, MODELS WERE FORECASTING A TROUGH MOVING INTO THE WEST
EARLY NEXT WEEK BRINGING SLIGHTLY COOLER TEMPERATURES FOR MEMORIAL
DAY. NOW THE TROUGH AND ANY ASSOCIATED SHORTWAVE ENERGY IS FORECAST
TO STAY WELL NORTH OF THE AREA AND HAVE LITTLE TO NO IMPACT ON
TEMPERATURES. THUS, HIGHS SHOULD TOP OUT A FEW DEGREES ABOVE NORMAL
SATURDAY THEN WARM ANOTHER 3-5 DEGREES SUNDAY AND HOLD STEADY MONDAY
AND POSSIBLY INTO TUESDAY. IT`S A DISTINCT POSSIBILITY THAT
TEMPERATURES COULD AGAIN REACH OR EVEN EXCEED 100 DEGREES IN LAS
VEGAS ON SUNDAY AND MEMORIAL DAY, BUT FOR NOW, DECIDED TO KEEP THEM
IN THE UPPER 90S TO SEE IF MODEL SOLUTIONS MAINTAIN CONTINUITY OR
REVERT BACK TO A STRONGER PACIFIC TROUGH MOVING INTO THE WEST. &&
.AVIATION...FOR MCCARRAN...SOUTHEAST TO EAST WINDS MAY EXCEED 10
KNOTS THROUGH EARLY EVENING BEFORE BECOMING LIGHT AND VARIABLE 1-2
HOURS AFTER SUNSET AND EARLY THURSDAY. AN EASTERLY WIND COMPONENT
CAN BE EXPECTED THURSDAY AFTERNOON. SCT CLOUDS WITH BASES 10-12 KFT
WILL REMAIN AROUND THE AREA WITH SHOWERS POSSIBLE OVER THE SPRING
MOUNTAINS AND SHEEP RANGE THROUGH EARLY THIS EVENING THEN AGAIN
THURSDAY AS A LOW PRESSURE SYSTEM CIRCULATES AROUND SOUTHERN
CALIFORNIA AND SOUTHERN NEVADA.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...A LOW PRESSURE
SYSTEM WILL MOVE FROM CENTRAL NEVADA TO SOUTHERN CALIFORNIA TONIGHT
AND THURSDAY. ISOLATED TO SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS CAN BE EXPECTED OVER AREAS TO THE NORTH AND WEST OF
LAS VEGAS THROUGH THURSDAY. CLOUD BASES WILL GENERALLY BE AROUND
8-10 KFT MSL AND WILL LEAD TO PARTIAL MOUNTAIN OBSCURATION OVER THE
SOUTHERN SIERRA.
&&
.VEF WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
AZ...NONE.
CA...NONE.
&&
$$
SHORT TERM/AVIATION...ADAIR
LONG TERM...SALMEN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
955 AM PDT WED MAY 21 2014
.SYNOPSIS...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL OCCUR
IN THE SOUTHERN GREAT BASIN AND WESTERN MOJAVE DESERT AND LAST
THROUGH FRIDAY. THE SYSTEM WILL FINALLY MOVE AWAY SATURDAY...WITH
RAIN CHANCES DIMINISHING AND TEMPERATURES WARMING OVER THE HOLIDAY
WEEKEND.
&&
.UPDATE...THE CUTOFF UPPER LOW COULD BE SEEN ON SATELLITE LOOPS WITH
A FAIRLY TIGHT CIRCULATION OVER CENTRAL NYE COUNTY THIS MORNING. IT
APPEARS A VORT LOBE IN THE NORTHWEST QUADRANT OF THE SYSTEM WILL
DIVE SOUTHWARD TODAY...ENHANCING SHOWERS AND ISOLATED THUNDERSTORMS
OVER ESMERALDA...INYO AND CENTRAL NYE COUNTIES. THE RUC AND LOCAL
HIGH RES MODELS ARE SHOWING INCREASING POTENTIAL FOR CONVECTION OVER
NORTHWEST SAN BERNARDINO COUNTY LATE THIS AFTERNOON AND EVENING
WHILE THE 12Z GFS KEEPS PRECIP POTENTIAL OVER THE SAN BERNARDINO
MOUNTAINS AND TOWARD THE COAST. NO IMMEDIATE CHANGES ARE NEEDED TO
THE GOING FORECAST AS ISOLATED SHOWERS ARE CURRENTLY INDICATED OVER
NORTHWEST SAN BERNARDINO COUNTY. THE REST OF THE FORECAST AREA
LOOKS FINE BASED ON THE LATEST SATELLITE LOOPS AND MODEL INDICATIONS.
&&
.PREV DISCUSSION...328 AM PDT...
.SHORT TERM...THROUGH FRIDAY NIGHT...AN UPPER LOW CUTOFF FROM THE
MAIN BRANCH OF THE WESTERLIES WILL REMAIN OVER THE REGION THROUGH
FRIDAY BEFORE SLOWLY SHIFTING INTO ARIZONA ON SATURDAY. THIS WILL
LEAD TO A PATTERN OF MAINLY AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS OCCURRING MOSTLY OVER THE HIGHER TERRAIN. ANY
REMAINING SOUTHWEST WINDS WILL BE ACROSS FAR EASTERN MOHAVE COUNTY
TODAY...OTHERWISE NOW THAT UPPER LOW IS OVERHEAD WINDS WILL BE MUCH
LIGHTER. WITH THAT BEING SAID OUTFLOW GUSTS FROM THUNDERSTORMS ARE
POSSIBLE. COOL ONCE AGAIN TODAY WITH TEMPERATURES BACK TO NEAR
NORMAL FRIDAY.
.LONG TERM...SATURDAY THROUGH TUESDAY.
MEMORIAL DAY WEEKEND IS LOOKING LIKE A PRETTY TOASTY WITH MODEL
CONSENSUS SHOWING HIGH PRESSURE MOVING OVER THE AREA DURING THE
WEEKEND. YESTERDAY, MODELS WERE FORECASTING A TROUGH MOVING INTO THE
WEST EARLY NEXT WEEK BRINGING SLIGHTLY COOLER TEMPERATURES FOR
MEMORIAL DAY. NOW THE TROUGH AND ANY ASSOCIATED SHORTWAVE ENERGY IS
FORECAST TO STAY WELL NORTH OF THE AREA AND HAVE LITTLE TO NO IMPACT
ON TEMPERATURES. THUS, HIGHS SHOULD TOP OUT A FEW DEGREES ABOVE
NORMAL SATURDAY THEN WARM ANOTHER 3-5 DEGREES SUNDAY AND HOLD STEADY
MONDAY AND POSSIBLY INTO TUESDAY. IT`S A DISTINCT POSSIBILITY THAT
TEMPERATURES COULD AGAIN REACH OR EVEN EXCEED 100 DEGREES IN LAS
VEGAS ON SUNDAY AND MEMORIAL DAY, BUT FOR NOW, DECIDED TO KEEP THEM
IN THE UPPER 90S TO SEE IF MODEL SOLUTIONS MAINTAIN CONTINUITY OR
REVERT BACK TO A STRONGER PACIFIC TROUGH MOVING INTO THE WEST.
&&
.AVIATION...FOR MCCARRAN...THE GRADIENT WIND WILL CONTINUE TO
SUBSIDE TODAY NOW THAT UPPER LOW HAS MOVED OVERHEAD. IN
FACT...LOOKING AT AN EAST OR SOUTHEAST WIND OF 5-9 KTS DEVELOPING
LATE THIS MORNING AND CONTINUING INTO THIS EVENING. A CHANGE IN
CONFIGURATION MAY BE NECESSARY. SCT-BKN CLOUDS AROUND 10-12 KFT
TODAY AND WEDNESDAY. HIGHER PEAKS WEST OF THE VALLEY WILL BE
PARTIALLY OBSCURED AT TIMES.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...AN UPPER LOW OVER THE AREA WILL LEAD TO A PATTERN OF
MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS TODAY AND
WEDNESDAY. CEILING GENERALLY BETWEEN 5-7 KFT WITH HIGHER PEAKS
PARTIALLY OBSCURED AT TIMES. WIND SPEEDS GENERALLY BETWEEN 5-15 MPH
EXCEPT HIGHER GUSTS NEAR THUNDERSTORMS.
&&
.VEF WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
AZ...NONE.
CA...NONE.
&&
$$
UPDATE...ADAIR
PREV DISCUSSION...PIERCE/SALMEN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
251 PM EDT WED MAY 21 2014
.SYNOPSIS...SURFACE HIGH PRESSURE MOVES SOUTH AHEAD OF A COLD FRONT
THAT SLOWLY MOVES SOUTH THROUGH THE REGION THURSDAY INTO FRIDAY.
ANOTHER SURFACE HIGH BUILDS SOUTHEAST OVER THE REGION FOR THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 250 PM WEDNESDAY...
THE LATEST SURFACE ANALYSIS SHOWED A SOUTHWEST-TO-WEST GRADIENT OVER
CENTRAL NORTH CAROLINA OUTSIDE OF A PAIR OF WEAK SURFACE TROUGHS
OVER WESTERN PARTS OF THE STATE...WITH A COLD FRONT WELL TO OUR
NORTH OVER THE GREAT LAKES. REGIONAL RADAR IMAGES SHOWED SCATTERED
DEEP CONVECTION DEVELOPING OVER THE OHIO VALLEY EAST ACROSS THE
BORDER OF PENNSYLVANIA AND MARYLAND...WHERE MIXED-LAYER CAPE WAS
HIGHER ON THE LATEST SPC MESOANALYSIS AND IN AN AXIS OF PRECIPITABLE
WATER VALUES APPROACHING 1.5 INCHES. BASED ON THE 1000-500MB
THICKNESS PROFILE AND 700MB HEIGHTS...ANY DEEP CONVECTION WOULD TEND
TO MOVE SOUTHEAST. THE LATEST SPC MESOANALYSIS INSTABILITY DATA
SUGGESTS MIXED-LAYER CIN STILL PRESENT OVER CENTRAL NORTH
CAROLINA... BUT THE GFS AND NAM BUFR SOUNDINGS...MORE SO THAN THE
LATEST RAP SOUNDINGS...SHOW THE MID-LEVEL CAP ERODING TOWARD 00Z
THROUGHOUT THE AREA...BUT PARTICULARLY TOWARD THE TRIAD.
IN GOOD GENERAL INSTABILITY...WITH LIFTED INDICES TO -5C ON THE
LATEST MSAS...ALONG WITH WEAK SURFACE CONVERGENCE COURTESY OF THE
SURFACE TROUGHS AND THE APPROACH OF A MID-LEVEL SHORTWAVE...AN
ISOLATED SHOWER OR THUNDERSTORM COULD DEVELOP LATE THIS AFTERNOON
INTO EARLY EVENING AS THE CAP ERODES...MAINLY ALONG AND NORTH OF
U.S. 64. LATER THIS EVENING AND INTO THE OVERNIGHT...SOME OF THE
CONVECTIVE-ALLOWING MODELS WOULD SUGGEST THE POTENTIAL FOR SHOWERS
FROM UPSTREAM CONVECTION MOVING SOUTH INTO CENTRAL NORTH CAROLINA...
WITH THE GREATER CHANCES OF THESE TOWARD THE NORTHWEST PIEDMONT AND
AREAS NORTH AND NORTHEAST OF THE TRIANGLE. ANY SHOWER EARLY THIS
EVENING...WITH GOOD LAPSE RATES...COULD PRODUCE A GUSTY WIND...
THOUGH IT WOULD SEEM WITH THE DIURNAL TIMING OF ANY CONVECTION LATER
TONIGHT AND BUFR SOUNDINGS SHOWING A RETURN OF A LITTLE WARMING
ALOFT THAT THE POTENTIAL FOR STRONG CONVECTION OVERNIGHT WOULD BE
LIMITED. ANTICIPATE SOME MID- AND HIGH-LEVEL CLOUDS AT TIMES
OVERNIGHT DUE TO REMNANTS OF UPSTREAM ACTIVITY...AND OVERNIGHT LOWS
SHOULD BE MOSTLY IN THE MID 60S.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 250 PM WEDNESDAY...
THE GFS FORECASTS AN INCREASE IN 850MB THETA-E AIR BY THURSDAY
AFTERNOON...WITH BOTH THE GFS AND THE NAM SUPPORTIVE OF A MODEST MID-
LEVEL SHORTWAVE MOVING NORTHWEST-TO-SOUTHEAST ACROSS CENTRAL NORTH
CAROLINA DURING THE AFTERNOON. THE SURFACE FRONT SHOULD BE STILL TO
OUR NORTHWEST THROUGH THE DAY THURSDAY...EVENTUALLY MOVING THROUGH
MUCH OF CENTRAL NORTH CAROLINA...IF NOT ALL OF THE AREA...THURSDAY
NIGHT. MIXED-LAYER CAPE IN THE LOWEST KM IS AGAIN 1000 TO
1500J/KG... AND DOWNDRAFT CAPE THURSDAY IS FORECAST TO APPROACH
1000J/KG ON THE GFS WITH LIFTED INDICES AT LEAST TO -5C. ONE
LIMITING FACTOR COULD BE THE LOW-LEVEL CONVERGENCE...WHICH MAY BE
REDUCED DUE TO ANTICIPATED VEERING OF THE LOW-LEVEL WINDS AHEAD OF
THE FRONT TO WEST-TO-NORTHWEST ON BOTH THE NAM AND THE GFS. CHANCES
OF PRECIPITATION ON BOTH GUIDANCE ARE LOW...AND CONVECTIVE ALLOWING
MODELS ARE LIMITED IN COVERAGE AS WELL IN GENERAL. STILL...WITH THE
APPROACH AND PASSAGE OF THE MID-LEVEL WAVE...AT LEAST MODEST
INSTABILITY...AND AN INCREASE IN OVERALL MOISTURE...WOULD ANTICIPATE
ISOLATED-TO-SCATTERED SHOWERS AND THUNDERSTORMS BY THURSDAY
AFTERNOON...WITH THIS FORECAST NOTING THE HIGHER CHANCES RELATIVE TO
THE REST OF THE AREA MAINLY ALONG AND SOUTH OF U.S. 64...WHERE THERE
SHOULD BE BETTER WARMING AND OVERALL INSTABILITY. ANY STRONG STORM
COULD PRODUCE A SEVERE WIND GUST BUT CURRENTLY SUCH AN OCCURRENCE
SEEMS ISOLATED. 1000-850MB THICKNESSES SUGGEST THE MAV MOS GUIDANCE
IS ON THE WARM SIDE AND HAVE FORECAST HIGHS THURSDAY WITH A BLEND OF
THE MAV AND THE MET FOR HIGHS FROM 89 TO 93. OVERNIGHT LOWS THURSDAY
NIGHT IN THE LOWER TO MID 60S AS ANY CHANCES FOR PRECIPITATION
DIMINISH...THOUGH THE GFS DOES FORECAST AN INCREASE IN MID-LEVEL
CLOUDS LATE TOWARD THE NORTHWEST PIEDMONT. -DJF
FOR FRI/FRI NIGHT: MODELS AGREE THAT THE FRONT WILL LIKELY BE JUST
SOUTH OF THE STATE FRI MORNING... WITH COOLER DEWPOINTS (IN THE 50S)
ADVECTING IN... BLUSTERY NW WINDS WITHIN A DEEP BOUNDARY LAYER
MAINLY IN THE AFTERNOON... AND ONLY AN ISOLATED SHOT AT A SHOWER OR
STORM IN THE SRN CWA WHERE THE SREF INDICATES A LINGERING AREA OF A
FEW HUNDRED J/KG OF MLCAPE... AND WHERE THE GFS SHOWS A WEAK SHEAR
AXIS SHIFTING ESE... ALONG WITH A WEAK SURFACE LOW. EVEN HERE
THOUGH... THE BOUNDARY LAYER WILL BE FAIRLY DRY... INHIBITING MUCH
COVERAGE... ALTHOUGH DCAPE VALUES WILL REMAIN HIGH ENOUGH TO BRING
ABOUT CONCERN FOR LOCALLY HIGHER WIND GUSTS NEAR ANY SHOWERS/STORMS.
IT IS WORTH NOTING THAT THE ECMWF IS BY FAR THE WETTEST OF THE
MODELS... SHOWING WIDESPREAD CONVECTION OVER THE ENTIRE CWA ALONG A
DIFFUSE AND FURTHER-NORTH SURFACE FRONT. THIS HAS BEEN DISCOUNTED
FOR NOW BUT WILL NEED TO MONITOR LATER RUNS. OTHERWISE... A DRY AND
STABLE COLUMN WILL ENSURE A DRY FORECAST OVER THE REMAINDER OF THE
CWA... DESPITE STRONG SHORTWAVE ENERGY ROTATING ABOUT THE MID LEVEL
VORTEX JUST TO OUR NNE. EXPECT SOME FLAT CUMULUS MAINLY IN THE
AFTERNOON IN THE NORTH AND EAST... WITH MID CLOUDS ACROSS THE FAR
SOUTH... AND THE FEWEST CLOUDS IN THE WRN CWA. HIGHS 80-87... CLOSER
TO THE COOLER NAM-BASED GUIDANCE. EXPECT GENERALLY CLEAR SKIES
FRIDAY NIGHT WITH A COOL CANADIAN-SOURCE (BUT MODIFYING) SURFACE
HIGH BUILDING IN FROM THE NNW. EXPECT BELOW NORMAL LOWS OF 50-57.
FOR SAT/SAT NIGHT: SURFACE HIGH PRESSURE COVERS THE OHIO VALLEY AND
MID-ATLANTIC REGION TO START THE WEEKEND... WITH DRY NW FLOW ALOFT
AND STABLE/SINKING MID LEVELS... ON THE SUBSIDENT SIDE OF THE UPPER
JET. WHILE THIS RESIDENT AIR MASS WILL CONTINUE TO SLOWLY MODIFY...
THICKNESSES WILL START THE DAY NEARLY 30 M BELOW NORMAL... SO HIGHS
ON THE COOL SIDE LOOK REASONABLE... 77-81. CONTINUED BELOW NORMAL
LOWS OF 52-57 WITH THE HIGH CENTER DRIFTING OVERHEAD. -GIH
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 250 PM WEDNESDAY...
EXPECTED CONTINUED DRY WEATHER SUNDAY FOR CENTRAL NC AS THE 850 MB
ANTICYCLONE HOLDS OVER THE SOUTHEAST STATES... WHILE THE SURFACE
HIGH DRIFTS SLOWLY OFF THE COAST... AND RIDGING HOLDS IN THE MID
LEVELS FROM THE OH VALLEY OVER THE MIDSOUTH/GULF STATES. THE
GFS/ECMWF BOTH FORM WEAK LEE TROUGHING OVER VA AND THE FAR WRN NW
PIEDMONT ON MEMORIAL DAY AS THE SURFACE HIGH MOVES FURTHER
OFFSHORE... AND BOTH DEVELOP CONVECTION OVER THE HIGHER TERRAIN MON
AFTERNOON. THIS DOES INDEED LOOK LIKE A GOOD SETUP FOR MOUNTAIN
CONVECTION... BUT THERE ISN`T A LOT OF OPPORTUNITY FOR MOISTURE
RETURN THIS QUICKLY ESPECIALLY WITH NWRLY 850 MB FLOW... AND IT`S
QUESTIONABLE IF ANY OF THIS ACTIVITY WILL BE ABLE TO REACH OUR WRN
CWA GIVEN THE VERY WEAK STEERING FLOW WITH THE MID LEVEL RIDGE AXIS
LOCATED JUST WEST OF THE MOUNTAINS. WILL RETAIN A MENTION OF
ISOLATED STORMS OVER THE FAR WRN CWA MON AFTERNOON INTO EARLY
EVENING. THE SYNOPTIC PATTERN REMAINS SIMILAR ON TUE WITH A VERY
WEAK STEERING FLOW... A SURFACE TROUGH EXTENDING THROUGH CENTRAL
NC... AND AN EVER-WARMING (THICKNESSES RISING TO ABOUT 20 M ABOVE
NORMAL) BUT FAIRLY DRY BOUNDARY LAYER. FORECAST SOUNDINGS CONTINUE
TO SHOW VERY LOW VALUES OF SKINNY CAPE... AND WITH NO DYNAMIC
FORCING MECHANISMS EVIDENT... WILL STICK WITH LOW CHANCE POPS...
FOCUSED ON SEA BREEZE ACTIVITY IN THE AFTERNOON. MODELS SHOW THE MID
LEVEL RIDGE BREAKING DOWN TUE NIGHT/WED WITH SOMEWHAT GREATER MID
LEVEL FLOW BECOMING GENTLY CYCLONIC. EXPECT A SLOW AND STEADY
INCREASE IN BOUNDARY LAYER MOISTURE WITH THICKNESSES HOLDING ABOVE
NORMAL... RESULTING IN A BIT BETTER CHANCE OF AFTERNOON CONVECTION
AREAWIDE. EXPECT TEMPS TO RISE EACH DAY... FROM HIGHS IN THE LOW 80S
AND LOWS AROUND 60 SUN TO THE UPPER 80S/AROUND 90 AND UPPER 60S BY
WED.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 220 PM WEDNESDAY...
VFR CONDITIONS ARE EXPECTED OVERALL DURING THE 18Z VALID TAF PERIOD.
SOMEWHAT DIFFICULT TO DETERMINE HIGHER AREAS...IN A RELATIVE SENSE
IN CENTRAL NORTH CAROLINA...FOR POTENTIAL FOR ANY SHOWERS OR STORMS
FROM VERY LATE THIS AFTERNOON THROUGH THE OVERNIGHT HOURS. HIGHEST
INSTABILITY AND THREAT FOR A SHOWER OR STORM...MAINLY FROM UPSTREAM
ACTIVITY MOVING INTO THE AREA...APPEARS TO BE TOWARD THE TRIAD AND
OVER FAR NORTHEAST NORTH CAROLINA MAINLY NORTHEAST OF KRWI.
INTRODUCED A PROB30 FOR A SHOWER OVERNIGHT AT KINT AND KGSO BASED ON
CONVECTIVE MODEL OUTPUT...KEPT SUCH CONDITIONS OUT AT OTHER TAFS
THOUGH THERE IS A LOW PROBABILITY OF A SHOWER AT ANY SITE OVERNIGHT.
SOUTHWEST-TO-WEST SURFACE WINDS SHOULD GRADUALLY VEER AND BE MORE
WEST-TO-NORTHWEST DURING THE DAY THURSDAY.
BEYOND THE 18Z VALID TAF PERIOD...ISOLATED-TO-SCATTERED
THUNDERSTORMS ARE POSSIBLE IN CENTRAL NORTH CAROLINA THURSDAY
AFTERNOON AND EVENING...AND THEN AGAIN MAINLY FRIDAY AFTERNOON
TOWARD KFAY. DRY CONDITIONS ARE EXPECTED THROUGH THE WEEKEND... AND
THEN PREDOMINANTLY DRY INTO MONDAY. OUTSIDE OF ANY SHOWER OR
STORM...VFR CONDITIONS ARE ANTICIPATED.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF/GIH
LONG TERM...GIH
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
220 PM EDT WED MAY 21 2014
.SYNOPSIS...SURFACE HIGH PRESSURE MOVES SOUTH AHEAD OF A COLD FRONT
THAT SLOWLY MOVES SOUTH THROUGH THE REGION THURSDAY INTO FRIDAY.
ANOTHER SURFACE HIGH BUILDS SOUTHEAST OVER THE REGION FOR THE
WEEKEND.
&&
.NEAR TERM /THIS AFTERNOON AND TONIGHT/...
AS OF 1040 AM WEDNESDAY...
CENTRAL NORTH CAROLINA WAS ON THE NORTHERN PART OF HIGH PRESSURE
SURFACE AND ALOFT THIS MORNING...AND THIS WILL CONTINUE THROUGH THE
AFTERNOON. SURFACE HIGH PRESSURE GRADUALLY MOVES FARTHER SOUTH...AND
WHILE THE 12Z UPPER-AIR ANALYSES SHOWED SOME MODEST MOISTURE AT
850MB AND 700MB OVER NORTH CAROLINA...THERE WAS DRIER AIR AT THESE
LEVELS TO THE WEST THAT SHOULD MOVE INTO THE AREA DURING THE LATE
MORNING AND INTO THE AFTERNOON. RAP MODEL GUIDANCE SUGGESTS THIS
THROUGH ITS MOISTURE FORECASTS AND SOUNDING PROFILES...WITH A RETURN
OF SOME MOISTURE LATE IN THE DAY AND INTO THIS EVENING COINCIDENT
WITH WHAT SHOULD BE A WEAKENING MID-LEVEL SHORTWAVE MOVING INTO
CENTRAL NORTH CAROLINA FROM THE NORTHWEST. RAP SOUNDINGS ARE QUITE
STABLE TO DEEP CONVECTION THROUGH THE EVENING...AND LOW-LEVEL
FORCING IS LIMITED EXCEPT FOR THE PIEDMONT TROUGH THAT SHOULD MOVE
SLIGHTLY EAST DURING THE AFTERNOON. RAP QPF IS DRY FOR THE DAY...AND
THE CONVECTIVE ALLOWING MODELS...EXCEPT FOR THE SPC NMM...SHOW A
LIMITED POTENTIAL FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON. THE
SPC NMM WOULD SUGGEST THE POTENTIAL FOR SCATTERED COVERAGE IN AREAS
ALONG AND NORTH OF ABOUT U.S. 64 AND ESPECIALLY EAST AND NORTHEAST
OF THE TRIANGLE VERY LATE THIS AFTERNOON INTO THIS EVENING. IF THE
RAP MIXING OF SURFACE DEW POINTS VERIFY...THIS TYPE OF COVERAGE
COULD BE DIFFICULT TO OBTAIN. PUSHING BACK THE TIMING...KEPT THE
SLIGHT CHANCE TO CHANCE PRECIPITATION FORECAST FOR THE PERIOD AFTER
21Z THROUGH THE EVENING ALONG AND NORTH OF A LINE FROM THE TRIAD TO
GOLDSBORO...THE LATTER IN DEFERENCE TO THE SPC NMM OUTPUT. EVEN IF
JUST A COUPLE OF SHOWERS OCCUR...STEEP 1000-500MB LAPSE RATES
APPROACHING 8C/KM AND DOWNDRAFT CAPE TO 800J/KG ON THE LATEST SPC
MESOANALYSIS OUTPUT COULD RESULT IN A GUSTY WIND. AFTERNOON HIGHS
MID 80S TO AROUND 90 WITH A FEW WIND GUSTS IN THE 20S MPH DEVELOPING
AS 925MB WINDS INCREASE THIS AFTERNOON TO 20 TO 25KT. UNDER PARTLY
CLOUDY SKIES TONIGHT ON AVERAGE...OVERNIGHT LOWS MOSTLY IN THE MID
60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...
THURSDAY AND THURSDAY NIGHT: DEEP NWLY FLOW ALOFT WILL PERSIST
ACROSS THE AREA THROUGH THURSDAY. A WEAK SURFACE FRONT OVER THE
SOUTHERN OHIO VALLEY/TN VALLEY WILL MOVE SOUTH AND EAST INTO THE
AREA THURSDAY AFTERNOON/EVENING...PROPELLED BY A STRONG SHORTWAVE
DIVING SE THROUGH THE GREAT LAKES. WEAK SFC CONVERGENT ALONG THE
FRONT COMBINED WITH STRONG DAYTIME HEATING AND RESULTANT MODERATE
DESTABILIZATION WILL HELP TO SUPPORT SCATTERED THUNDERSTORMS
THURSDAY AFTERNOON AND EVENING. THE MAIN LIMITING FACTOR FOR GREATER
CONVECTIVE COVERAGE WILL BE THE LACK OF DEEP MOISTURE OWING TO NWLY
FLOW ALOFT AND WITH WHAT COULD BE A PERIOD OF SUBSIDENCE/DNVA IN THE
WAKE OF SHORTWAVE DISTURBANCES EXITING THURSDAY MORNING THAT COULD
ACT TO SUPPRESS CONVECTION THURSDAY AFTERNOON. AGAIN...ANY STORMS
THAT DEVELOP WILL HAVE THE POTENTIAL TO PRODUCE DAMAGING
THUNDERSTORM WIND GUSTS AS MODELS SHOW CONTINUED STRONG DCAPE OVER
THE PIEDMONT WITH THE DRY MID-LEVEL AIR AND STEEP LOW-LEVEL LAPSE
RATES...AND A BELT OF 30-40KT BULK SHEAR.
CONVECTION SHOULD DIE DOWN AROUND MIDNIGHT AS THE WEAK BOUNDARY
SETTLES TO OUR SOUTH. ARRIVAL COOLER AIR WILL BE DELAYED UNTIL
FRIDAY/FRIDAY NIGHT...SO LOWS THURSDAY NIGHT WILL STILL BE IN THE
60S.
THE FRONTAL ZONE WILL FINALLY SLIP INTO THE AREA FRIDAY AS ANOTHER
SHORTWAVE SWINGS ACROSS THE MID-ATLANTIC STATES AND A JET DIVES
THROUGH THE TN VALLEY. DRIER AIR FILTERING IN FROM THE NORTH SHOULD
SUPPRESS THE 60F DEWPOINTS AND MLCAPE OF AROUND 1000 J/KG TO THE
SOUTHERN PIEDMONT AND SANDHILLS. DEEP LAYER SHEAR WILL BE STILL
STRONG DUE TO THE AFOREMENTIONED JET AND COULD STILL SUPPORT SOME
ENHANCED UPDRAFTS AND A DAMAGING WIND THREAT...MAINLY CLOSER THE
NC/SC BORDER WHERE LOW-LEVEL LAPSE RATES WILL BE STEEPEST. DEEP
NORTHWEST FLOW WILL CONTINUE TO LIMIT MOISTURE OVERALL...BUT MODELS
APPEAR MORE ACTIVE WITH CONVECTION THAN IN PREVIOUS RUNS. WILL
NUDGE SLIGHT CHANCE POPS UP A BIT ACROSS THE SOUTH...WITH HIGHS
RANGING FROM LOWER 80S NORTH TO UPPER 80S SOUTH. ONCE ANY CONVECTION
COMES TO AN END AND DEWPOINTS BEGIN FALLING INTO THE 50S BEHIND THE
FRONT...LOWS WILL DIP INTO THE 50S AS WELL...55-60 NORTH TO SOUTH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 320 AM WEDNESDAY...
MUCH MORE SEASONABLE AND STABLE AIR WILL RESIDE OVER THE AREA THIS
WEEKEND AS THE COLD FRONT PUSHES SOUTH AND HIGH PRESSURE BUILDS IN
FROM THE GREAT LAKES REGION. THICKNESSES BOTTOM OUT AROUND 1360M
SATURDAY MORNING...WHICH SUGGEST HIGHS WILL BE JUST SLIGHTLY BELOW
NORMA IN THE UPPER 70S AND LOWER 80S SATURDAY AND SUNDAY. LOWS WILL
BE IN THE 50S. MEANWHILE...THE UPPER TOUGH OFF THE EAST COAST WILL
BEGIN TO GIVE WAY TO A RIDGE BUILDING FROM THE SOUTHERN PLAINS
TOWARD THE MIDWEST...SIGNALING A WARMING TREND EARLY NEXT WEEK WITH
HIGHS BACK IN THE 80S. THERE IS A LITTLE MORE UNCERTAINTY IN THE
LONGWAVE PATTERN TOWARD THE MIDDLE OF THE WEEK AS A THE REMNANTS OF
AN UPPER LOW OVER THE SOUTHWESTERN US DRIFTS ACROSS THE CENTRAL US.
HOWEVER...MOISTURE WILL BE INCREASING AS HIGH PRESSURE SHIFTS
OFFSHORE...BRINGING AN INCREASE IN THE POSSIBILITY OF SOME AFTERNOON
SHOWERS AND STORMS...MORE SO ON TUESDAY AND WEDNESDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 220 PM WEDNESDAY...
VFR CONDITIONS ARE EXPECTED OVERALL DURING THE 18Z VALID TAF PERIOD.
SOMEWHAT DIFFICULT TO DETERMINE HIGHER AREAS...IN A RELATIVE SENSE
IN CENTRAL NORTH CAROLINA...FOR POTENTIAL FOR ANY SHOWERS OR STORMS
FROM VERY LATE THIS AFTERNOON THROUGH THE OVERNIGHT HOURS. HIGHEST
INSTABILITY AND THREAT FOR A SHOWER OR STORM...MAINLY FROM UPSTREAM
ACTIVITY MOVING INTO THE AREA...APPEARS TO BE TOWARD THE TRIAD AND
OVER FAR NORTHEAST NORTH CAROLINA MAINLY NORTHEAST OF KRWI.
INTRODUCED A PROB30 FOR A SHOWER OVERNIGHT AT KINT AND KGSO BASED ON
CONVECTIVE MODEL OUTPUT...KEPT SUCH CONDITIONS OUT AT OTHER TAFS
THOUGH THERE IS A LOW PROBABILITY OF A SHOWER AT ANY SITE OVERNIGHT.
SOUTHWEST-TO-WEST SURFACE WINDS SHOULD GRADUALLY VEER AND BE MORE
WEST-TO-NORTHWEST DURING THE DAY THURSDAY.
BEYOND THE 18Z VALID TAF PERIOD...ISOLATED-TO-SCATTERED
THUNDERSTORMS ARE POSSIBLE IN CENTRAL NORTH CAROLINA THURSDAY
AFTERNOON AND EVENING...AND THEN AGAIN MAINLY FRIDAY AFTERNOON
TOWARD KFAY. DRY CONDITIONS ARE EXPECTED THROUGH THE WEEKEND... AND
THEN PREDOMINANTLY DRY INTO MONDAY. OUTSIDE OF ANY SHOWER OR
STORM...VFR CONDITIONS ARE ANTICIPATED.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...CBL/BLS
LONG TERM...BLS
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
939 PM CDT THU MAY 22 2014
.UPDATE...
ISSUED AT 929 PM CDT THU MAY 22 2014
NEW MODEL RUNS OF RAP AND NAM SHOW SOME CONVECTION BEGINNING
AROUND MIDNIGHT OR SHORTLY AFTER IN THE JAMES RIVER VALLEY.
SHIFTED THE FOCUS ON THIS AREA OVERNIGHT. ADDED CLOUDS ALSO TO THE
CENTRAL AND EAST. OTHERWISE NO OTHER CHANGES.
UPDATE ISSUED AT 621 PM CDT THU MAY 22 2014
MID LEVEL WARM ADVECTION SUPPORTING FLAT CUMULUS FIELD ACROSS WEST
AND CENTRAL NORTH DAKOTA. BUFKIT SOUNDINGS FROM 12Z NAM SHOWING
LIMITED POTENTIAL TO GROW WITH MID LEVEL WARM LAYER KEEPING THE
CONVECTION IN CHECK. THUS BELIEVE THE NAM SO FAR HAS A BETTER
HANDLE ON THE CONVECTIVE POTENTIAL. TRIMMED POPS BACK FOR THE
EVENING BUT DID KEEP SMALL POPS ACROSS THE FAR WEST AND SOUTHWEST
WHERE MID LEVEL WARM LAYER WEAKER.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 250 PM CDT THU MAY 22 2014
MAIN FORECAST ISSUE THIS AFTERNOON WILL BE THUNDERSTORM CHANCES.
CURRENTLY...ATMOSPHERE CONTINUES TO DESTABILIZE OVER EASTERN
MONTANA INTO WESTERN NORTH DAKOTA. HOWEVER...MID LEVEL CAPPING AND
WEAK SHEAR WILL INHIBIT CONVECTION LATE THIS AFTERNOON AND
OVERNIGHT. CAN NOT RULE OUT A FEW THUNDERSTORMS AND HAVE
MAINTAINED A SLIGHT CHANCE OF THUNDER IN THE SOUTHWEST LATE THIS
AFTERNOON AND INTO THE CENTRAL TONIGHT.
FRIDAY WILL BRING ANOTHER CHANCE OF AFTERNOON AND EVENING
THUNDERSTORMS. SHEAR PROFILE REMAINS WEAK WITH A MID LEVEL RIDGE
OVER THE AREA. HOWEVER...WE WILL SEE INCREASING LOW LEVEL MOISTURE
AS DEWPOINTS INCREASE WELL INTO THE 50S. WE SHOULD ALSO BE A GOOD
4 TO 8 DEGREES WARMER...THUS THE RISK OF STORMS WILL BE A LITTLE
GREATER AND THE SEVERE THREAT...ALTHOUGH STILL MINIMAL...WILL BE
GREATER THAN THIS AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 250 PM CDT THU MAY 22 2014
AN UNSETTLED WEATHER PATTERN REMAINS ON TRACK FOR THIS UPCOMING
WEEKEND FOLLOWED BY A BRIEF LULL FOR MOST OF MONDAY AND TUESDAY.
SUCCESSIVE SHORTWAVES RETURN WITH PERIODIC CHANCES FOR SHOWERS AND
THUNDERSTORMS WEDNESDAY AND THURSDAY. SOME DISCREPANCY IN THE
GFS/ECMWF SOLUTIONS BEGINNING MONDAY IN TERMS OF TIMING OF
SHORTWAVES AND COVERAGE OF PRECIPITATION. THROUGHOUT THE LONG TERM
PERIOD EXPECT HIGH TEMPERATURES IN THE 70S TO AROUND 80...WITH
OVERNIGHT LOWS IN THE 50S.
FOR FRIDAY NIGHT INTO SATURDAY NIGHT...INCREASING LOW LEVEL
MOISTURE/DEWPOINTS VIA A SOUTHERLY FLOW WILL RESULT IN PRECIPITABLE
WATER VALUES OF BETWEEN AN INCH AND ONE AND A HALF INCHES ACROSS
SOUTHERN NORTH DAKOTA FRIDAY NIGHT INTO EARLY SUNDAY...WHICH
INCLUDES DICKINSON...BISMARCK...AND JAMESTOWN. MAIN PLAYER IS AN
UPPER LOW SPINNING OVER NEVADA WHICH WILL EJECT A SIGNIFICANT MID
LEVEL SHORTWAVE INTO WESTERN SOUTH DAKOTA 12Z SATURDAY...AND THEN
TRACKING INTO NORTH CENTRAL NORTH DAKOTA BY SATURDAY EVENING. THE
MID LEVEL SHORTWAVE IS FORECAST TO BECOME A CLOSED LOW SATURDAY
NIGHT AS IT SLOWS UP AND SCOOTS INTO SOUTHERN MANITOBA. AT THE
SURFACE A COLD FRONT WILL BE SLIDING ACROSS WESTERN NORTH DAKOTA
SATURDAY EVENING AND THEN INTO PORTIONS OF CENTRAL NORTH DAKOTA
EARLY SUNDAY MORNING. SUFFICIENT INSTABILITY WILL BE IN PLACE WITH
0-6KM BULK SHEAR INCREASING TO AROUND 30KT DURING THE AFTERNOON
WHICH SHOULD LEAD TO A BETTER POTENTIAL FOR SEVERE THUNDERSTORMS
ESPECIALLY IN THE WEST...CLOSER TO THE SURFACE LOW AND MID LEVEL
SHORTWAVE. IN ADDITION...THE NAM/GFS SOUNDINGS INDICATE A FATTER
CAPE/LARGER AREA/POTENTIALLY STRONGER UPDRAFTS WILL RESIDE AT KISN
SOUTH TO KDIK SATURDAY AFTERNOON/EVENING. SPC HAS THIS AREA IN A SEE
TEXT INDICATING A HIGHER POTENTIAL OF SEVERE WEATHER AT THIS TIME.
OTHERWISE THERE IS GOOD AGREEMENT IN THE AREAL COVERAGE OF
PRECIPITATION ACROSS WESTERN AND CENTRAL NORTH DAKOTA AND HAVE
INCREASED POPS TO LIKELY AND/OR CATEGORICAL IN SOME AREAS BASED ON
THIS SATURDAY AFTERNOON AND EVENING.
ON SUNDAY...AS MENTIONED ABOVE...A SURFACE COLD FRONT WILL BE MOVING
INTO CENTRAL NORTH DAKOTA IN THE MORNING AND INTO THE SOUTHERN JAMES
RIVER VALLEY LATE IN THE AFTERNOON. COOLER/DRIER AIR AND MORE STABLE
CONDITIONS WILL NOSE INTO THE FAR WEST BY AFTERNOON WITH A MINIMAL
THREAT FOR PRECIPITATION. HOWEVER DECENT INSTABILITY AND SHEAR
APPEARS TO RESIDE IN SOUTH CENTRAL NORTH DAKOTA SPECIFICALLY OVER
THE SOUTHERN JAMES RIVER VALLEY. THIS LOOKS TO BE THE POSSIBLE
TARGET AREA FOR SEVERE WEATHER SUNDAY AFTERNOON AND EVENING.
MONDAY AND TUESDAY...MID LEVEL RIDGING THEN TAKES CONTROL BEHIND
SUNDAYS SHORTWAVE RESULTING IN DRY WEATHER MONDAY AND MONDAY NIGHT.
THE ECMWF IS FASTER IN SHIFTING ANOTHER SHORTWAVE THROUGH MONDAY
NIGHT INTO TUESDAY MAINLY AFFECTING THE NORTHWEST AND NORTH CENTRAL.
THE GFS IS MAINLY DRY. AFTER COLLABORATING WITH NEIGHBORING OFFICES
HAVE REDUCED POPS DURING THIS PERIOD PER WHAT THE ALLBLEND WAS
INDICATING. SOUTHERLY FLOW WILL ONCE AGAIN INCREASE TUESDAY ALLOWING
A LOW LEVEL MOISTENING TREND INTO WESTERN AND CENTRAL NORTH DAKOTA.
WEDNESDAY INTO THURSDAY...SUCCESSIVE SHORTWAVES EMBEDDED WITHIN A
SOUTHWEST FLOW WILL ONCE AGAIN RESULT IN MORE SHOWERS AND
THUNDERSTORMS FOR WESTERN AND CENTRAL NORTH DAKOTA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 929 PM CDT THU MAY 22 2014
WIND FLOW AROUND HIGH PRESSURE ACROSS MINNESOTA WILL MAINTAIN A
SOUTHERLY FLOW OF AIR ACROSS THE DAKOTAS THROUGH THE TAF PERIOD.
VFR EXPECTED. WIDELY SCATTERED/ISOLATED THUNDERSTORMS POSSIBLE
CENTRAL WITH THE JAMES RIVER VALLEY SEEING SCATTERED
THUNDERSTORMS AFTER MIDNIGHT. WILL INCLUDE A VCTS FOR KJMS
TONIGHT. OTHERWISE TIMING AND LOCATION AT OTHER TAF SITES ARE
UNCERTAIN THEREFORE DID NOT INCLUDE IN TAF FORECASTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...TWH
LONG TERM...KS
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1258 PM CDT WED MAY 21 2014
.UPDATE...
ISSUED AT 1255 PM CDT WED MAY 21 2014
NO CHANGES NEEDED. CLOUDS BREAKING UP DVL-FAR BUT THICKER IN NW MN
AS EXPECTED. EXPECT SLOW CLEARING AND CURRENT TEMPS APPEAR OK.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
CLOUDS AND TEMPERATURES WILL BE THE MAIN ISSUE FOR THE PERIOD.
WEST TO NORTHWESTERLY FLOW ALOFT WILL CONTINUE AS THE UPPER TROUGH
FROM YESTERDAY PULLS OFF TO THE EAST. THERE HAS BEEN PLENTY OF
CLOUDS BEHIND THE COLD FRONT THAT MOVED THROUGH...WITH THE ENTIRE
CWA SEEING MOSTLY CLOUDY SKIES THIS MORNING. RUC13 925-850MB RH WHICH
HAS A GOOD HANDLE ON CLOUDS DOES NOT REALLY SEE MUCH DECREASE
UNTIL THE MIDDLE OF THE DAY. THINK THAT CLOUDS WILL CONTINUE FOR
AT LEAST PART OF THE MORNING BEFORE HIGH PRESSURE MOVES IN THIS
AFTERNOON. THINK THAT THERE SHOULD BE SOME SUN LATE IN THE DAY AND
TEMPS WILL STILL GET INTO THE 60S.
TONIGHT...WE SHOULD CONTINUE TO SEE DECREASING CLOUDS AND WINDS
WILL BECOME LIGHT AS THE CENTER OF THE HIGH SETTLES OVER THE AREA.
DEW POINTS WILL DROP DOWN TO NEAR 40 DEGREES AND LOWS WILL BE
MAINLY IN THE LOW TO MID 40S ACROSS THE AREA. WILL HAVE TO WATCH
FOR SOME PATCHY FOG FORMATION BUT NOT CONFIDENT ENOUGH TO INCLUDE
IN THE GRIDS AT THIS POINT. THE UPPER RIDGE WILL CONTINUE TO BUILD
INTO THE PLAINS ON THURSDAY. LIGHT SOUTHEAST WINDS AND SOME SUN
WILL HELP TEMPS GET TO NEAR 70 DEGREES.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE UPPER RIDGE CONTINUES TO
BUILD INTO CANADA...AND MODELS SHOW SOME INDICATION OF SOME FAIRLY
WEAK WAVES RIDING ALONG THE BACK SIDE OF THE RIDGE. THERE COULD BE
SOME CONVECTIVE ACTIVITY WITH THESE WAVES...ALTHOUGH MODELS HAVE
MOST OF PRECIP TO OUR WEST AT THIS POINT. GIVEN THE UPPER LEVEL
FLOW SOME CONVECTION CLIPPING OUR NORTHWESTERN COUNTIES WILL BE
POSSIBLE...SO INCLUDED SOME LOW POPS THURSDAY NIGHT AND FRIDAY.
ACTIVITY WILL BE FURTHER EAST FRIDAY NIGHT AS THE RIDGE AXIS
SHIFTS A BIT EASTWARD AND MOISTURE TRANSPORT KICKS IN. INCLUDED
POPS BEYOND THE DEVILS LAKE AREA BUT KEPT THEM PRETTY LOW FOR NOW.
TEMPS THROUGH THE END OF THE WORK WEEK WILL BE WARMING UP TO ABOVE
NORMAL VALUES WITH HIGHS IN THE MID TO UPPER 70S.
FOR SATURDAY INTO SUNDAY...UPPER LEVEL RIDGE AXIS HAS SHIFTED OVER
THE AREA...WITH WARMER TEMPERATURES EXPECTED INTO THE MID TO UPPER
70S. A SERIES OF DISTURBANCES LOOK TO RIDE OVER THE RIDGE AXIS
DECREASING STABILITY AND ALLOWING FOR BETTER CHANCES FOR SHOWERS AND
TSTMS. OTHERWISE...FOR MONDAY AND TUESDAY...LOOK FOR CONTINUED WARM
TEMPS WITH SHOWERS DECREASING AS SFC HIGH PRESSURE SETTLES ACROSS
THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1255 PM CDT WED MAY 21 2014
STRATUS DECK ERODED QUICKLY IN SE ND AND IS LINGERING IN N RRV. AS A
RESULT FAR AND DVL WILL SEE SCT CIGS EARLY THIS AFTN AND TVF AND GFK
LIFTING STRATUS BEFORE SCT MID TO LATE AFTN AND BJI THIS EVENING.
VFR OVERNIGHT WITH A BIT OF A POTENTIAL FOR FOG DEVELOPMENT WITH
LIGHT WINDS...NOT MENTIONED IN THE TAFS DUE TO LOW CONFIDENCE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...JK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1007 AM CDT WED MAY 21 2014
.UPDATE...
ISSUED AT 1004 AM CDT WED MAY 21 2014
MAIN FCST ISSUE IS TEMPS/CLOUD COVER. CYCLONIC FLOW AROUND SFC LOW
NEAR THUNDER BAY ONTARIO ALONG WITH COLD ADVECTION WILL KEEP
WRAPAROUND CLOUD COVER WELL INTO THE AFTN OVER NW MN. SOME HOLES
WILL OCCUR HOWEVER AS SUN IS ABOVE THE CLOUD LAYER AND SOME THIN
BREAKS ALREADY. BUT OVERALL INCREASED CLOUD COVER THRU THE AFTN
AND LOWERED TEMPS A FEW DEGREES IN NE MN. FOR THE RRV AND ERN ND
EXPECT MORE SUN AS THE DAY PROGRESSES AND WITH THAT DIDNT TINKER
MUCH WITH TEMPS YET.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
CLOUDS AND TEMPERATURES WILL BE THE MAIN ISSUE FOR THE PERIOD.
WEST TO NORTHWESTERLY FLOW ALOFT WILL CONTINUE AS THE UPPER TROUGH
FROM YESTERDAY PULLS OFF TO THE EAST. THERE HAS BEEN PLENTY OF
CLOUDS BEHIND THE COLD FRONT THAT MOVED THROUGH...WITH THE ENTIRE
CWA SEEING MOSTLY CLOUDY SKIES THIS MORNING. RUC13 925-850MB RH WHICH
HAS A GOOD HANDLE ON CLOUDS DOES NOT REALLY SEE MUCH DECREASE
UNTIL THE MIDDLE OF THE DAY. THINK THAT CLOUDS WILL CONTINUE FOR
AT LEAST PART OF THE MORNING BEFORE HIGH PRESSURE MOVES IN THIS
AFTERNOON. THINK THAT THERE SHOULD BE SOME SUN LATE IN THE DAY AND
TEMPS WILL STILL GET INTO THE 60S.
TONIGHT...WE SHOULD CONTINUE TO SEE DECREASING CLOUDS AND WINDS
WILL BECOME LIGHT AS THE CENTER OF THE HIGH SETTLES OVER THE AREA.
DEW POINTS WILL DROP DOWN TO NEAR 40 DEGREES AND LOWS WILL BE
MAINLY IN THE LOW TO MID 40S ACROSS THE AREA. WILL HAVE TO WATCH
FOR SOME PATCHY FOG FORMATION BUT NOT CONFIDENT ENOUGH TO INCLUDE
IN THE GRIDS AT THIS POINT. THE UPPER RIDGE WILL CONTINUE TO BUILD
INTO THE PLAINS ON THURSDAY. LIGHT SOUTHEAST WINDS AND SOME SUN
WILL HELP TEMPS GET TO NEAR 70 DEGREES.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE UPPER RIDGE CONTINUES TO
BUILD INTO CANADA...AND MODELS SHOW SOME INDICATION OF SOME FAIRLY
WEAK WAVES RIDING ALONG THE BACK SIDE OF THE RIDGE. THERE COULD BE
SOME CONVECTIVE ACTIVITY WITH THESE WAVES...ALTHOUGH MODELS HAVE
MOST OF PRECIP TO OUR WEST AT THIS POINT. GIVEN THE UPPER LEVEL
FLOW SOME CONVECTION CLIPPING OUR NORTHWESTERN COUNTIES WILL BE
POSSIBLE...SO INCLUDED SOME LOW POPS THURSDAY NIGHT AND FRIDAY.
ACTIVITY WILL BE FURTHER EAST FRIDAY NIGHT AS THE RIDGE AXIS
SHIFTS A BIT EASTWARD AND MOISTURE TRANSPORT KICKS IN. INCLUDED
POPS BEYOND THE DEVILS LAKE AREA BUT KEPT THEM PRETTY LOW FOR NOW.
TEMPS THROUGH THE END OF THE WORK WEEK WILL BE WARMING UP TO ABOVE
NORMAL VALUES WITH HIGHS IN THE MID TO UPPER 70S.
FOR SATURDAY INTO SUNDAY...UPPER LEVEL RIDGE AXIS HAS SHIFTED OVER
THE AREA...WITH WARMER TEMPERATURES EXPECTED INTO THE MID TO UPPER
70S. A SERIES OF DISTURBANCES LOOK TO RIDE OVER THE RIDGE AXIS
DECREASING STABILITY AND ALLOWING FOR BETTER CHANCES FOR SHOWERS AND
TSTMS. OTHERWISE...FOR MONDAY AND TUESDAY...LOOK FOR CONTINUED WARM
TEMPS WITH SHOWERS DECREASING AS SFC HIGH PRESSURE SETTLES ACROSS
THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 643 AM CDT WED MAY 21 2014
CONDITIONS HAVE BEEN VARYING BETWEEN MVFR AND IFR...ALTHOUGH A FEW
SPOTS HAVE LIFTED TO 3500 FT IN THE NORTHERN FORECAST AREA. CIGS
WILL CONTINUE TO SLOWLY LIFT...MOVING UP INTO THE MVFR TO VFR
RANGE LATER THIS MORNING...THEN EVENTUALLY CLEARING OUT. FIRST TO
CLEAR OUT WILL BE KDVL WHILE KBJI WILL HANG ONTO CLOUDS UNTIL LATE
AFTERNOON. NORTHWEST WINDS AT 10 TO 15 KTS WILL BECOME LIGHT AND
VARIABLE AFTER SUNSET.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
643 AM CDT WED MAY 21 2014
.UPDATE...
ISSUED AT 643 AM CDT WED MAY 21 2014
MADE SOME MINOR TWEAKS TO CLOUD COVER...THINK WE SHOULD SLOWLY SEE
SOME ERODING THROUGHOUT THE DAY ALTHOUGH THE FAR EASTERN TIER MAY
SEE CLOUDS HANG ON A BIT LONGER. NO OTHER MAJOR CHANGES.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
CLOUDS AND TEMPERATURES WILL BE THE MAIN ISSUE FOR THE PERIOD.
WEST TO NORTHWESTERLY FLOW ALOFT WILL CONTINUE AS THE UPPER TROUGH
FROM YESTERDAY PULLS OFF TO THE EAST. THERE HAS BEEN PLENTY OF
CLOUDS BEHIND THE COLD FRONT THAT MOVED THROUGH...WITH THE ENTIRE
CWA SEEING MOSTLY CLOUDY SKIES THIS MORNING. RUC13 925-850MB RH WHICH
HAS A GOOD HANDLE ON CLOUDS DOES NOT REALLY SEE MUCH DECREASE
UNTIL THE MIDDLE OF THE DAY. THINK THAT CLOUDS WILL CONTINUE FOR
AT LEAST PART OF THE MORNING BEFORE HIGH PRESSURE MOVES IN THIS
AFTERNOON. THINK THAT THERE SHOULD BE SOME SUN LATE IN THE DAY AND
TEMPS WILL STILL GET INTO THE 60S.
TONIGHT...WE SHOULD CONTINUE TO SEE DECREASING CLOUDS AND WINDS
WILL BECOME LIGHT AS THE CENTER OF THE HIGH SETTLES OVER THE AREA.
DEW POINTS WILL DROP DOWN TO NEAR 40 DEGREES AND LOWS WILL BE
MAINLY IN THE LOW TO MID 40S ACROSS THE AREA. WILL HAVE TO WATCH
FOR SOME PATCHY FOG FORMATION BUT NOT CONFIDENT ENOUGH TO INCLUDE
IN THE GRIDS AT THIS POINT. THE UPPER RIDGE WILL CONTINUE TO BUILD
INTO THE PLAINS ON THURSDAY. LIGHT SOUTHEAST WINDS AND SOME SUN
WILL HELP TEMPS GET TO NEAR 70 DEGREES.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE UPPER RIDGE CONTINUES TO
BUILD INTO CANADA...AND MODELS SHOW SOME INDICATION OF SOME FAIRLY
WEAK WAVES RIDING ALONG THE BACK SIDE OF THE RIDGE. THERE COULD BE
SOME CONVECTIVE ACTIVITY WITH THESE WAVES...ALTHOUGH MODELS HAVE
MOST OF PRECIP TO OUR WEST AT THIS POINT. GIVEN THE UPPER LEVEL
FLOW SOME CONVECTION CLIPPING OUR NORTHWESTERN COUNTIES WILL BE
POSSIBLE...SO INCLUDED SOME LOW POPS THURSDAY NIGHT AND FRIDAY.
ACTIVITY WILL BE FURTHER EAST FRIDAY NIGHT AS THE RIDGE AXIS
SHIFTS A BIT EASTWARD AND MOISTURE TRANSPORT KICKS IN. INCLUDED
POPS BEYOND THE DEVILS LAKE AREA BUT KEPT THEM PRETTY LOW FOR NOW.
TEMPS THROUGH THE END OF THE WORK WEEK WILL BE WARMING UP TO ABOVE
NORMAL VALUES WITH HIGHS IN THE MID TO UPPER 70S.
FOR SATURDAY INTO SUNDAY...UPPER LEVEL RIDGE AXIS HAS SHIFTED OVER
THE AREA...WITH WARMER TEMPERATURES EXPECTED INTO THE MID TO UPPER
70S. A SERIES OF DISTURBANCES LOOK TO RIDE OVER THE RIDGE AXIS
DECREASING STABILITY AND ALLOWING FOR BETTER CHANCES FOR SHOWERS AND
TSTMS. OTHERWISE...FOR MONDAY AND TUESDAY...LOOK FOR CONTINUED WARM
TEMPS WITH SHOWERS DECREASING AS SFC HIGH PRESSURE SETTLES ACROSS
THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 643 AM CDT WED MAY 21 2014
CONDITIONS HAVE BEEN VARYING BETWEEN MVFR AND IFR...ALTHOUGH A FEW
SPOTS HAVE LIFTED TO 3500 FT IN THE NORTHERN FORECAST AREA. CIGS
WILL CONTINUE TO SLOWLY LIFT...MOVING UP INTO THE MVFR TO VFR
RANGE LATER THIS MORNING...THEN EVENTUALLY CLEARING OUT. FIRST TO
CLEAR OUT WILL BE KDVL WHILE KBJI WILL HANG ONTO CLOUDS UNTIL LATE
AFTERNOON. NORTHWEST WINDS AT 10 TO 15 KTS WILL BECOME LIGHT AND
VARIABLE AFTER SUNSET.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
321 AM CDT WED MAY 21 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
CLOUDS AND TEMPERATURES WILL BE THE MAIN ISSUE FOR THE PERIOD.
WEST TO NORTHWESTERLY FLOW ALOFT WILL CONTINUE AS THE UPPER TROUGH
FROM YESTERDAY PULLS OFF TO THE EAST. THERE HAS BEEN PLENTY OF
CLOUDS BEHIND THE COLD FRONT THAT MOVED THROUGH...WITH THE ENTIRE
CWA SEEING MOSTLY CLOUDY SKIES THIS MORNING. RUC13 925-850MB RH WHICH
HAS A GOOD HANDLE ON CLOUDS DOES NOT REALLY SEE MUCH DECREASE
UNTIL THE MIDDLE OF THE DAY. THINK THAT CLOUDS WILL CONTINUE FOR
AT LEAST PART OF THE MORNING BEFORE HIGH PRESSURE MOVES IN THIS
AFTERNOON. THINK THAT THERE SHOULD BE SOME SUN LATE IN THE DAY AND
TEMPS WILL STILL GET INTO THE 60S.
TONIGHT...WE SHOULD CONTINUE TO SEE DECREASING CLOUDS AND WINDS
WILL BECOME LIGHT AS THE CENTER OF THE HIGH SETTLES OVER THE AREA.
DEW POINTS WILL DROP DOWN TO NEAR 40 DEGREES AND LOWS WILL BE
MAINLY IN THE LOW TO MID 40S ACROSS THE AREA. WILL HAVE TO WATCH
FOR SOME PATCHY FOG FORMATION BUT NOT CONFIDENT ENOUGH TO INCLUDE
IN THE GRIDS AT THIS POINT. THE UPPER RIDGE WILL CONTINUE TO BUILD
INTO THE PLAINS ON THURSDAY. LIGHT SOUTHEAST WINDS AND SOME SUN
WILL HELP TEMPS GET TO NEAR 70 DEGREES.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE UPPER RIDGE CONTINUES TO
BUILD INTO CANADA...AND MODELS SHOW SOME INDICATION OF SOME FAIRLY
WEAK WAVES RIDING ALONG THE BACK SIDE OF THE RIDGE. THERE COULD BE
SOME CONVECTIVE ACTIVITY WITH THESE WAVES...ALTHOUGH MODELS HAVE
MOST OF PRECIP TO OUR WEST AT THIS POINT. GIVEN THE UPPER LEVEL
FLOW SOME CONVECTION CLIPPING OUR NORTHWESTERN COUNTIES WILL BE
POSSIBLE...SO INCLUDED SOME LOW POPS THURSDAY NIGHT AND FRIDAY.
ACTIVITY WILL BE FURTHER EAST FRIDAY NIGHT AS THE RIDGE AXIS
SHIFTS A BIT EASTWARD AND MOISTURE TRANSPORT KICKS IN. INCLUDED
POPS BEYOND THE DEVILS LAKE AREA BUT KEPT THEM PRETTY LOW FOR NOW.
TEMPS THROUGH THE END OF THE WORK WEEK WILL BE WARMING UP TO ABOVE
NORMAL VALUES WITH HIGHS IN THE MID TO UPPER 70S.
FOR SATURDAY INTO SUNDAY...UPPER LEVEL RIDGE AXIS HAS SHIFTED OVER
THE AREA...WITH WARMER TEMPERATURES EXPECTED INTO THE MID TO UPPER
70S. A SERIES OF DISTURBANCES LOOK TO RIDE OVER THE RIDGE AXIS
DECREASING STABILITY AND ALLOWING FOR BETTER CHANCES FOR SHOWERS AND
TSTMS. OTHERWISE...FOR MONDAY AND TUESDAY...LOOK FOR CONTINUED WARM
TEMPS WITH SHOWERS DECREASING AS SFC HIGH PRESSURE SETTLES ACROSS
THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1142 PM CDT TUE MAY 20 2014
HAVE LOWERED CIGS AND DELAYED CLEARING UNTIL LATE AFTN FOR ND
SITES AND EARLY AFTN FOR MN SITES TOMORROW. LOWEST CIGS WILL BE
OVER NWRN MN AT TVF...WITH IFR CIGS THROUGH MID MORNING...AND
DROPPING INTO LOWER MVFR RANGE AT BJI BY 12Z. MVFR CIGS FROM THE
NORTHERN VALLEY THROUGH THE DEVILS LAKE AREA WILL FINALLY BEGIN TO
CLEAR OUT...FROM WEST TO EAST...BY MID MORNING AND THE CLEAR LINE
WILL WORKS ITS WAY ACROSS MN THROUGHOUT THE DAY...REACHING BJI BY
ABOUT 21Z.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1142 PM CDT TUE MAY 20 2014
.UPDATE...
ISSUED AT 1142 PM CDT TUE MAY 20 2014
REMOVED POPS FOR FAR NORTHEAST AND INCREASED SKY COVER IN LINE
WITH RUC LOW LEVEL MOISTURE FIELD. NO OTHER CHANGES TO THIS FORECAST.
UPDATE ISSUED AT 924 PM CDT TUE MAY 20 2014
FORECAST CHALLENGE FOR TONIGHT WILL BE SKY AND OVERNIGHT LOWS. LOW
CLOUDS OVER MUCH OF N CNTRL ND DID NOT BREAK UP AS MUCH AS PREV
THOUGHT...AND WILL INCREASE SKY ACROSS AREA GRADUALLY OVERNIGHT
TONIGHT. RUC 925-850 LYRD RH IDEA SEEMS MOST LIKELY...WITH OVC
SKIES SPREADING ACROSS AREAS THAT ARE CURRENTLY CLEAR AND NW NOT
CLEARING OUT UNTIL MID MORNING TOMORROW. WILL HOWEVER REMOVE POPS
FOR THE NIGHT AS RADAR UNIMPRESSIVE.
UPDATE ISSUED AT 643 PM CDT TUE MAY 20 2014
MAIN ISSUES FOR THIS UPDATE WILL BE PROBABILITY FOR PRECIP ACROSS
THE NORTH AND ADJUSTMENTS TO SKY GRIDS.
CANADIAN RADARS SHOWING SHOWERS ROTATING AROUND THE UPPER LOW
BEGINNING TO DRY UP AS THEY APPROACH SOUTHERN AND SOUTHEASTERN
MANITOBA. WILL REMOVE POPS THROUGH 06Z AND KEEP LOW CHANCE POPS
FOR LAKE OF THE WOODS AFT 06Z. MAY PULL PRIOR TO NEXT UPDATE IF
NOTHING BEGINS TO REDEVELOP...HOWEVER WILL REMOVE MENTION OF
THUNDER. FOR SKY...MUCH OF SOUTHEASTERN HALF OF CWA IS CLEAR OR
CLEARING IN THE CELLULAR CU OVER EASTERN ZONES. WILL HAVE MOSTLY
CLEAR WORDING THROUGH 06Z...WITH INCREASED CLOUD COVER AS CLOUDS
OVER THE DEVILS LAKE BASIN BEGIN TO FILL IN CLEAR AREAS. LOOKS
LIKE THIS WILL HOLD TOGETHER LONG ENOUGH TO KEEP NORTHEASTERN
PORTION OF CWA MOSTLY CLOUDY TOMORROW...WHICH WILL ALSO IMPACT
AVIATION (SEE DISCUSSION BELOW).
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM CDT TUE MAY 20 2014
FORECAST CHALLENGE CONCERNS LOW END PCPN CHANCES AND TEMPERATURES.
MODELS IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD AND WILL USE
BLEND.
SURFACE/UPPER LOW WILL CONTINUE TO PROPAGATE EAST ALONG THE
MN/CANADIAN BORDER OVERNIGHT. CU FIELD EXPANDING SOUTHWARD WITH
THICKEST CLOUD COVER ALONG A DVL-ROX LINE. AIRMASS NOT VERY
UNSTABLE UNDER MID LEVEL COOLER AIR WITH NIL CAPE. A FEW SHOWERS
APPROACHING THE N CENTRAL ND BORDER AREA OTHERWISE ANY RAIN STILL
FARTHER NORTH INTO CANADA. FOR THIS DO NOT HAVE A LOT OF
CONFIDENCE ON SHRA POTENTIAL LATER THIS AFTERNOON INTO THE
EVENING. MODELS FOR THE MOST PART KEEPING ANY SHRA ACTIVITY
HUGGING THE INTERNATIONAL BORDER. WILL MAINTAIN SOME SLIGHT/LOW
CHANCES BUT AGAIN CONFIDENCE NOT HIGH. COLD ADVECTION WILL PUSH
THROUGH THE FA TONIGHT SO EXPECT MINIMUMS GENERALLY IN THE 40S.
LOW LEVEL COLD POOL OVER FA TOMORROW MORNING WILL SHIFT EAST
ACROSS MN DURING THE DAY WITH SOME WARM ADVECTION FROM THE VALLEY
WEST. NOT A GREAT DEAL OF MIXING EXPECTED WITH SURFACE HIGH
OVERHEAD. CONVECTIVE TEMPERATURES INITIALLY LOW BUT RAISE DURING
THE DAY SO DO EXPECT SOLAR. FEEL OPERATIONAL MODELS OVERDONE ON
QPF WEDNESDAY AFTERNOON SO KEPT FORECAST DRY. OVERALL EXPECT
TEMPERATURES AROUND 5 DEGREES BLO SEASONAL NORMS.
LIGHT WINDS AND SKC SHOULD ALLOW TEMPERATURES TO DROP OFF INTO THE
LOW TO MID 40S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 315 PM CDT TUE MAY 20 2014
HIGH SHIFTS SLIGHTLY EAST THURSDAY WITH COLUMN CONTINUING TO WARM.
MIXING WILL STILL REMAIN LIGHT HOWEVER WITH SOLAR EXPECT
TEMPERATURES CLOSER TO NORMAL.
WITH WARM ADVECTION AND WARMER COLUMN IN PLACE MINIMUM TEMPERATURES
NOT AS COOL THURSDAY NIGHT. MAIN MOISTURE TRANSPORT AND RELATED
INSTABILITY WILL REMAIN WELL TO OUR WEST OVER THE WESTERN DAKOTAS.
LOW CONFIDENCE ON EASTWARD EXTENT OF ANY LATE NIGHT/EARLY MORNING
RESIDUAL PCPN SO LIMITED POPS TO THE FAR WESTERN FA.
MIXING AND SURFACE MOISTURE FLUX INCREASES FRIDAY. HOW WARM WE GET
WILL DEPEND ON DEGREE OF CLOUD COVER BUT OVERALL TEMPERATURES
SHOULD BE AT OR A LITTLE ABOVE AVERAGE. SOME INSTABILITY WORKS
INTO THE WESTERN FA HOWEVER WITH LACK OF LOW LEVEL FORCING FEEL FA
FOR THE MOST PART WILL BE DRY.
THE FRIDAY NIGHT THROUGH TUESDAY PERIOD FINALLY HAS A STRING OF DAYS
WITH WARMER TEMPERATURES. ALONG WITH THESE WARMER TEMPERATURES WILL
ALSO FEATURE A RETURN TO SOME HUMIDITY. RIDGING OVER THE CENTRAL
PART OF THE COUNTRY WILL SLOWLY BE REPLACED BY SOUTHWEST FLOW WITH A
CUTOFF LOW KICKING OUT INTO THE CENTRAL PLAINS. HIGH TEMPS EACH DAY
SHOULD RANGE IN THE UPPER 70S TO AROUND 80. UNFORTUNATELY THE
COMBINATION OF HEAT HUMIDITY AND SOUTHWEST FLOW MEANS AN INCREASED
CHANCE FOR SHOWERS AND TSTMS. ESSENTIALLY EACH DAY CARRIES SOME
MENTION OF PCPN BUT REALISTICALLY THERE WILL BE SOME DRY PERIODS.
JUST HARD TO NAIL DOWN THIS FAR OUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1142 PM CDT TUE MAY 20 2014
HAVE LOWERED CIGS AND DELAYED CLEARING UNTIL LATE AFTN FOR ND
SITES AND EARLY AFTN FOR MN SITES TOMORROW. LOWEST CIGS WILL BE
OVER NWRN MN AT TVF...WITH IFR CIGS THROUGH MID MORNING...AND
DROPPING INTO LOWER MVFR RANGE AT BJI BY 12Z. MVFR CIGS FROM THE
NORTHERN VALLEY THROUGH THE DEVILS LAKE AREA WILL FINALLY BEGIN TO
CLEAR OUT...FROM WEST TO EAST...BY MID MORNING AND THE CLEAR LINE
WILL WORKS ITS WAY ACROSS MN THROUGHOUT THE DAY...REACHING BJI BY
ABOUT 21Z.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...SPEICHER
SHORT TERM...VOELKER
LONG TERM...GODON/VOELKER
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1011 PM EDT THU MAY 22 2014
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH OF THE REGION INTO THE TENNESSEE RIVER
VALLEY OVERNIGHT. HIGH PRESSURE BEHIND THE FRONT WILL BUILD ACROSS
THE AREA FRIDAY THROUGH SATURDAY NIGHT. FAIR WEATHER AND SEASONABLE
TEMPERATURES ARE EXPECTED TONIGHT THROUGH SATURDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
WITH EXTRAORDINARY LIGHT SPRINKLES OBSERVED AT NWS
WILMINGTON...AND A CONSISTENT SIGNAL ON THE HRRR THAT LIGHT ECHOES
WILL PASS OVER THE SOUTHERN THIRD OF THE CWA OVER THE NEXT 4-8
HOURS...A SLIGHT CHANCE OF SPRINKLES HAS BEEN ADDED TO THE
FORECAST FOR THE SOUTHERN TWO OR THREE TIERS OF COUNTIES.
OTHERWISE...VERY FEW CHANGES WERE NECESSARY...WITH TEMPERATURES
APPEARING TO BE ON TRACK. WHERE CLEARER SKIES ARE MORE LIKELY IN
THE FAR NORTH...TEMPERATURES WERE LOWERED JUST A COUPLE DEGREES.
PREVIOUS DISCUSSION >
SPLIT FLOW MID/UPR LEVEL FLOW PATTERN WITH CLOSED LOW OVER THE SW
U.S. AND RIDGE OVER THE GULF STATES. BAND OF NW MID LEVEL FLOW
FROM THE WESTERN GREAT LAKES INTO THE OHIO VALLEY TO PREVAIL
OVERNIGHT. SFC COLD FRONT OVER NORTHERN KENTUCKY TO PUSH SOUTH
INTO THE TN VALLEY AND STALL OUT OVERNIGHT. SOME HIGH AND MID LEVEL
CLOUDS DEBRIS CLOUDS FROM DECAYING CONVECTION WILL SPILL INTO THE
REGION THRU THE EARLY MORNING HOURS. GENERALLY EXPECT A PARTLY
CLOUDY SKY WITH CLOUDS THINNING OUT LATE ESPECIALLY NORTH.
TONIGHTS LOWS WILL BE COOLER WITH DRIER AIR FILTER IN. READINGS TO
TO RANGE FROM THE UPPER 40S NW TO THE MID 50S SE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
NORTHWEST MID/UPR LEVEL FLOW TO PERSIST THRU THE FCST PERIOD. SURFACE
HIGH PRESSURE WILL BUILD SOUTHEASTWARD INTO THE AREA FRIDAY...BECOMING
CENTERED OVER OUR AREA FRIDAY NIGHT. EXPECT PARTLY CLOUDY SKY CONDITIONS
DURING THE DAYLIGHT HOURS WITH SKIES BECOMING MOSTLY CLEAR FRIDAY NIGHT.
WITH THE DRIER AIR ADVECTING INTO THE REGION...DEWPOINTS TO DROP
INTO THE MID AND UPPER 40S. HIGHS ON FRIDAY WILL RANGE FROM NEAR
70 NE TO THE MID 70S SW. IN DRY AIRMASS WITH LIGHT WIND FLOW EXPECT
FRIDAY NIGHTS LOWS TO RANGE FROM THE UPPER 40S NE TO THE LOWER 50S SW.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
SURFACE HIGH WILL RIDE A NORTHWEST UPPER FLOW ACROSS THE AREA
SATURDAY AND SUNDAY TO BECOME CENTERED TO THE SOUTHEAST ON MONDAY.
THIS WILL KEEP A DRY WEATHER PATTERN OVER THE ILN FA.
THE HIGH WILL MOVE FARTHER TO THE EAST ON TUESDAY...WHILE SHORT WAVE
ENERGY AND MOISTURE START TO SPILL INTO THE OHIO VALLEY OVER AN
ERODING UPPER RIDGE. THIS SCENARIO WILL PRODUCE A CHANCE OF
THUNDERSTORMS TUESDAY INTO WEDNESDAY. ON THURSDAY WE MAY SEE A
RETURN TO DRY CONDITIONS AS THE UPPER RIDGE STRENGTHENS AHEAD OF AN
UPPER LOW CENTERED OVER THE GREAT PLAINS.
TEMPERATURES WILL EXHIBIT A WARMING TREND IN RELATION TO THE
MOVEMENT OF THE HIGH PRESSURE. AFTER HIGHS REACH THE 70S ON
SATURDAY...READINGS WILL RISE PRIMARILY INTO THE 80S SUNDAY THROUGH
THURSDAY DUE TO WARM ADVECTION AND INSOLATION.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. NUMEROUS HIGH
CLOUDS WILL CONTINUE TO MOVE ACROSS THE REGION TONIGHT...BUT THESE
CLOUDS SHOULD GRADUALLY THIN GOING INTO THE OVERNIGHT HOURS.
DIURNAL CUMULUS IN CENTRAL OHIO WILL ALSO GENERALLY
DISSIPATE...THOUGH THERE ARE SOME INDICATIONS OF LOW-LEVEL
MOISTURE REMAINING IN PLACE TONIGHT...WHICH COULD LEAD TO A FEW
PATCHES OF STRATOCUMULUS.
TOMORROW...WINDS WILL REMAIN OUT OF THE NORTHWEST...WITH DIURNAL
CUMULUS EXPECTED TO DEVELOP.
OUTLOOK...THUNDERSTORMS ARE POSSIBLE ON TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...HATZOS/AR
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
158 PM EDT WED MAY 21 2014
.SYNOPSIS...
THUNDERSTORMS WILL MOVE ACROSS THE REGION TODAY AHEAD OF A COLD
FRONT. THE COLD FRONT WILL CROSS THE REGION TONIGHT. HIGH PRESSURE
WILL THEN BRING FAIR WEATHER TO OUR AREA FOR THE REMAINDER OF THE
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST FOCUS IN THE NEAR TERM IS THE POTENTIAL FOR SEVERE
WEATHER THIS AFTERNOON INTO THIS EVENING. A 17Z ILN SOUNDING WILL
BE LAUNCHED TO INTERROGATE ATMOSPHERIC CHANGES FROM THIS MORNING
AND ALSO TO AID FOR BETTER ATMOSPHERIC ASSESSMENT FOR LATER THIS
AFTN.
IT LOOKS LIKE THAT PERHAPS THE LATEST HRRR MAY BE LATCHING ON AS
TO WHAT TRANSPIRES LATER THIS AFTERNOON AND EVENING. SCATTERED
CONVECTION ACRS NRN INDIANA INTO NRN/CNTRL OHIO IS WHAT REMAINS
OF NOCTURNAL CONVECTION THAT PUSHED INTO THE REGION WELL AHEAD OF
A COLD FRONT. HRRR AND OTHER MESOSCALE MODELS SUGGEST THAT A
PREFRONTAL CONVERGENCE BOUNDARY...LIKELY AIDED BY CURRENT
CONVECTION...SHOULD ALLOW CONVECTION TO EXPAND IN COVERAGE AND
INTENSITY AS IT SHIFTS SOUTHEAST TOWARD AN INCREASING UNSTABLE
AIRMASS TO THE SOUTH AND SOUTHWEST. DECENT BULK SHEAR WILL EXIST
FOR ORGANIZATION OF STORMS IN EITHER LINE SEGMENTS OR PERHAPS
DISCRETE ROTATORS. MOIST AIR IN THE FORM OF MID/UPPER 60S
DEWPOINTS SHOULD ADVECT INTO THE REGION THIS AFTERNOON. THESE
VALUES COUPLED WITH SFC TEMPS APPROACHING THE LOWER 80S SHOULD
YIELD MLCAPES IN THE 1500-2000 J/KG...WHICH IS MODERATE
INSTABILITY. GIVEN POTENTIAL FOR ROTATORS AND DECENT
INSTABILITY...COUPLED WITH FAVORABLE WET BULB ZERO VALUES IN THE
9-10 FT RANGE...LARGE HAIL IS A CONCERN. ALSO...MID LEVEL DRIER
AIR WILL RESULT IN ENTRAINMENT AND WITH DCAPES PUSHING INTO THE
1500 J/KG...DAMAGING DOWNBURSTS WITH THE HAIL AND/OR PCPN LOADING
WILL ALSO BE A CONCERN. CAN NOT RULE AT AN ISOLATED TORNADO...BUT
IF THIS WERE TO OCCUR...IT WOULD LIKELY BE A RESULT OF CELL
MERGERS AND/OR OUTFLOW BOUNDARIES WITH DEVELOPING CELLS. FORECAST
CALLS FOR LIKELY POPS THIS AFTN WITH THE POPS SHIFTING TOWARD THE
OHIO RIVER BY EVENING. HIGHS WILL RANGE FROM THE UPPER 70S NORTH
TO THE LOWER 80S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
ONGOING CONVECTION THIS EVENING SAGGING SOUTH OF THE OHIO RIVER
WILL CONTINUE A SLOW PROGRESSION SOUTH AHEAD OF THE COLD FRONT.
MODELS ARE INDICATING A DECREASE IN FORWARD PROPAGATION OF THE
FRONTAL SYSTEM SOUTH OF THE OHIO RIVER TONIGHT. THIS COULD POSE
A FLASH FLOOD THREAT IF STORMS BEGIN TO TRAIN ACROSS THE SAME
LOCATIONS LATE THIS EVENING. WILL HOLD OFF ON ANY MENTION OF THIS
IN THE HWO...AS THERE IS A LARGE AMOUNT OF UNCERTAINTY AS TO THIS
SCENARIO TAKING PLACE DUE TO UNCERTAINTIES IN THE EVENTUAL
LOCATION OF THE FRONTAL BOUNDARY AT THIS TIME FRAME.
THE ILN CWA IS EXPECTED TO BE MAINLY RAIN FREE BY DAYBREAK
THURSDAY WITH THE FRONT SHIFTING SOUTH OF OUR AREA. NORTHWESTERLY
FLOW WILL BRING DRIER AIR INTO THE REGION WITH SEASONABLE
TEMPERATURES AND FAIR WEATHER ON THURSDAY.
HIGH PRESSURE WILL SLOWLY BUILD SOUTHEASTWARD INTO OUR AREA FROM
THE MID WEST THROUGH FRIDAY AND FRIDAY NIGHT. SURFACE WINDS WILL
REMAIN NORTHWESTERLY THURSDAY NIGHT THROUGH FRIDAY AND WILL BECOME
LIGHT ON FRIDAY NIGHT AS THE HIGH BECOMES CENTERED ACROSS THE
REGION. EXPECT MOSTLY CLEAR SKIES DURING THE THURSDAY NIGHT
THROUGH FRIDAY NIGHT TIME PERIOD WITH NEAR NORMAL TEMPERATURES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL ALLOW FOR DRY CONDITIONS THROUGH THE WEEKEND.
COOL NORTHERLY FLOW WILL KEEP TEMPERATURES IN THE UPPER 60S TO LOW
70S ON FRIDAY. A RIDGE WILL GRADUALLY WORK INTO THE REGION THROUGH
THE WEEKEND WITH TEMPERATURES WARMING EACH DAY. BY MONDAY HIGH
TEMPERATURES ARE EXPECTED TO BE IN THE 80S ACROSS THE ENTIRE FA.
PRECIPITATION LOOKS TO HOLD OFF UNTIL TUESDAY. THE GFS IS TRYING TO
DEVELOP A FEW THUNDERSTORMS ACROSS NW PORTIONS OF THE FA ON MONDAY
HOWEVER DECIDED TO GO WITH A DRY FORECAST ON MONDAY AT THIS TIME.
ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE DURING THE DAY
ON TUESDAY. ANY THUNDERSTORM ACTIVITY IS EXPECTED TO DISSIPATE
DURING THE EVENING HOURS WITH THE LOSS OF DAYTIME HEATING.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
SHOWERS AND THUNDERSTORMS ARE FORECAST TO DEVELOP THIS AFTERNOON
NEAR THE NORTHERN TAF SITES IN AN AXIS OF LOW LEVEL CONVERGENCE.
ONCE THIS CONVECTION GETS GOING...IT SHOULD DEVELOP INTO A BROKEN
LINEAR STRUCTURE AS IT MOVES SOUTHEAST THROUGH THE TAF SITES AS IT
FEEDS ON A MOIST AND UNSTABLE AIRMASS. THUNDERSTORMS WILL BE
CAPABLE OF CONTAINING DAMAGING WINDS AND LARGE HAIL WITH BRIEF
MVFR TO IFR VISIBILITIES. ONLY GENERIC MVFR CONDITIONS WITH
THUNDERSTORMS HAVE BEEN PLACED IN THE TAFS ATTM...ALLOWING SHORT
TERM RADAR TRENDS DICTATE THE POTENTIAL FOR DETAILS AND AMENDMENTS.
FOR TONIGHT...MAIN CONVECTION SHOULD BE PUSHING SOUTH OF THE OHIO
RIVER. A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST.
IT APPEARS THAT THE FORCING WITH THE FRONT ITSELF WILL BE WEAK AT
BEST AND MOST CONVECTION IS EXPECTED TO WANE ACRS THE REGION THIS
EVENING WITH DECREASING INSTABILITY. SKIES WILL LIKELY GO PARTLY
CLOUDY OVERNIGHT AND WITH RECENT RAINFALL...SOME MVFR TO LOCALLY
IFR MIST MAY DEVELOP. THE FOG POTENTIAL WILL BE PARTICULARLY HIGHER
ACRS THE SRN TAF SITES WHERE FRONTAL PASSAGE WILL NOT OCCUR UNTIL
NEAR OR AFTER SUNRISE.
ON THURSDAY...FRONT PUSHES SOUTH OF THE REGION. CAA BEHIND THE
FRONT ALONG WITH 850 MB MOISTURE WILL EVENTUALLY ALLOW A BROKEN
CUMULUS DECK TO DEVELOP.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN/LATTO
NEAR TERM...HICKMAN
SHORT TERM...LATTO
LONG TERM...NOVAK
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1155 AM EDT WED MAY 21 2014
.SYNOPSIS...
THUNDERSTORMS WILL MOVE ACROSS THE REGION TODAY AHEAD OF A COLD
FRONT. THE COLD FRONT WILL CROSS THE REGION TONIGHT. HIGH PRESSURE
WILL THEN BRING FAIR WEATHER TO OUR AREA FOR THE REMAINDER OF THE
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST FOCUS IN THE NEAR TERM IS THE POTENTIAL FOR SEVERE
WEATHER THIS AFTERNOON INTO THIS EVENING. A 17Z ILN SOUNDING WILL
BE LAUNCHED TO INTERROGATE ATMOSPHERIC CHANGES FROM THIS MORNING
AND ALSO TO AID FOR BETTER ATMOSPHERIC ASSESSMENT FOR LATER THIS
AFTN.
IT LOOKS LIKE THAT PERHAPS THE LATEST HRRR MAY BE LATCHING ON AS
TO WHAT TRANSPIRES LATER THIS AFTERNOON AND EVENING. SCATTERED
CONVECTION ACRS NRN INDIANA INTO NRN/CNTRL OHIO IS WHAT REMAINS
OF NOCTURNAL CONVECTION THAT PUSHED INTO THE REGION WELL AHEAD OF
A COLD FRONT. HRRR AND OTHER MESOSCALE MODELS SUGGEST THAT A
PREFRONTAL CONVERGENCE BOUNDARY...LIKELY AIDED BY CURRENT
CONVECTION...SHOULD ALLOW CONVECTION TO EXPAND IN COVERAGE AND
INTENSITY AS IT SHIFTS SOUTHEAST TOWARD AN INCREASING UNSTABLE
AIRMASS TO THE SOUTH AND SOUTHWEST. DECENT BULK SHEAR WILL EXIST
FOR ORGANIZATION OF STORMS IN EITHER LINE SEGMENTS OR PERHAPS
DISCRETE ROTATORS. MOIST AIR IN THE FORM OF MID/UPPER 60S
DEWPOINTS SHOULD ADVECT INTO THE REGION THIS AFTERNOON. THESE
VALUES COUPLED WITH SFC TEMPS APPROACHING THE LOWER 80S SHOULD
YIELD MLCAPES IN THE 1500-2000 J/KG...WHICH IS MODERATE
INSTABILITY. GIVEN POTENTIAL FOR ROTATORS AND DECENT
INSTABILITY...COUPLED WITH FAVORABLE WET BULB ZERO VALUES IN THE
9-10 FT RANGE...LARGE HAIL IS A CONCERN. ALSO...MID LEVEL DRIER
AIR WILL RESULT IN ENTRAINMENT AND WITH DCAPES PUSHING INTO THE
1500 J/KG...DAMAGING DOWNBURSTS WITH THE HAIL AND/OR PCPN LOADING
WILL ALSO BE A CONCERN. CAN NOT RULE AT AN ISOLATED TORNADO...BUT
IF THIS WERE TO OCCUR...IT WOULD LIKELY BE A RESULT OF CELL
MERGERS AND/OR OUTFLOW BOUNDARIES WITH DEVELOPING CELLS. FORECAST
CALLS FOR LIKELY POPS THIS AFTN WITH THE POPS SHIFTING TOWARD THE
OHIO RIVER BY EVENING. HIGHS WILL RANGE FROM THE UPPER 70S NORTH
TO THE LOWER 80S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
ONGOING CONVECTION THIS EVENING SAGGING SOUTH OF THE OHIO RIVER
WILL CONTINUE A SLOW PROGRESSION SOUTH AHEAD OF THE COLD FRONT.
MODELS ARE INDICATING A DECREASE IN FORWARD PROPAGATION OF THE
FRONTAL SYSTEM SOUTH OF THE OHIO RIVER TONIGHT. THIS COULD POSE
A FLASH FLOOD THREAT IF STORMS BEGIN TO TRAIN ACROSS THE SAME
LOCATIONS LATE THIS EVENING. WILL HOLD OFF ON ANY MENTION OF THIS
IN THE HWO...AS THERE IS A LARGE AMOUNT OF UNCERTAINTY AS TO THIS
SCENARIO TAKING PLACE DUE TO UNCERTAINTIES IN THE EVENTUAL
LOCATION OF THE FRONTAL BOUNDARY AT THIS TIME FRAME.
THE ILN CWA IS EXPECTED TO BE MAINLY RAIN FREE BY DAYBREAK
THURSDAY WITH THE FRONT SHIFTING SOUTH OF OUR AREA. NORTHWESTERLY
FLOW WILL BRING DRIER AIR INTO THE REGION WITH SEASONABLE
TEMPERATURES AND FAIR WEATHER ON THURSDAY.
HIGH PRESSURE WILL SLOWLY BUILD SOUTHEASTWARD INTO OUR AREA FROM
THE MID WEST THROUGH FRIDAY AND FRIDAY NIGHT. SURFACE WINDS WILL
REMAIN NORTHWESTERLY THURSDAY NIGHT THROUGH FRIDAY AND WILL BECOME
LIGHT ON FRIDAY NIGHT AS THE HIGH BECOMES CENTERED ACROSS THE
REGION. EXPECT MOSTLY CLEAR SKIES DURING THE THURSDAY NIGHT
THROUGH FRIDAY NIGHT TIME PERIOD WITH NEAR NORMAL TEMPERATURES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE WILL ALLOW FOR DRY CONDITIONS THROUGH THE WEEKEND.
COOL NORTHERLY FLOW WILL KEEP TEMPERATURES IN THE UPPER 60S TO LOW
70S ON FRIDAY. A RIDGE WILL GRADUALLY WORK INTO THE REGION THROUGH
THE WEEKEND WITH TEMPERATURES WARMING EACH DAY. BY MONDAY HIGH
TEMPERATURES ARE EXPECTED TO BE IN THE 80S ACROSS THE ENTIRE FA.
PRECIPITATION LOOKS TO HOLD OFF UNTIL TUESDAY. THE GFS IS TRYING TO
DEVELOP A FEW THUNDERSTORMS ACROSS NW PORTIONS OF THE FA ON MONDAY
HOWEVER DECIDED TO GO WITH A DRY FORECAST ON MONDAY AT THIS TIME.
ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE DURING THE DAY
ON TUESDAY. ANY THUNDERSTORM ACTIVITY IS EXPECTED TO DISSIPATE
DURING THE EVENING HOURS WITH THE LOSS OF DAYTIME HEATING.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
THUNDERSTORMS ARE CONTINUING TO TRACK EAST SOUTHEASTWARD ALONG A
BOUNDARY STRETCHING FROM NORTHERN ILLINOIS THROUGH NORTHERN INDIANA
INTO NORTHERN OHIO. THESE STORMS ARE BEING MAINTAINED IN PART BY A
20-30 KNOT 925-850 MB LOW LEVEL JET. AS THIS JET BEGINS TO WEAKEN
THROUGH MID MORNING...EXPECT TO SEE A DECREASE IN THUNDERSTORM COVERAGE
AND INTENSITY OFF TO OUR NORTHWEST. HOWEVER...WE WILL DESTABILIZE
FAIRLY QUICKLY THROUGH LATE MORNING AND INTO THIS AFTERNOON. THIS
WILL COMBINE WITH THE BOUNDARY SAGGING DOWN INTO OUR AREA...TO
RESULT IN MORE WIDESPREAD THUNDERSTORM ACTIVITY THIS
AFTERNOON...POSSIBLY LINGERING INTO THIS EVENING AT THE SOUTHERN
TAF SITES. THERE IS QUITE A BIT OF VARIANCE AMONG THE HI-RES AND
LARGER SCALE MODELS IN REGARD TO THE TIMING AND PLACEMENT OF THIS
REDEVELOPMENT. WILL THEREFORE ALLOW FOR A FAIRLY GENERAL VCTS ON
INTO THIS EVENING WITH A SHORTER TIME FRAME TEMPO -TSRA
GROUP...TRYING TO TARGET THE TIMING OF THE BETTER CHANCE OF
THUNDERSTORMS. DRIER AIR WILL FILTER IN FROM THE NORTHWEST LATER
THIS AFTERNOON INTO THIS EVENING...ALLOWING FOR PCPN TO TAPER OFF
NORTHWEST TO SOUTHEAST THROUGH THIS EVENING.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN/LATTO
NEAR TERM...HICKMAN
SHORT TERM...LATTO
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
149 AM EDT WED MAY 21 2014
.SYNOPSIS...
WARM FRONT LIFTING NORTHEAST TONIGHT. WARMER AND MORE HUMID AIR WITH
ROUNDS OF CONVECTION INTO THURSDAY MORNING. COLD FRONT SAGS SOUTH
THURSDAY. DRIER FRIDAY INTO SUNDAY. WARM...HUMID MEMORIAL DAY.
&&
.NEAR TERM /THROUGH TODAY/...
MADE SOME MINOR ADJUSTMENTS AND REFINEMENTS TO THE TIMING ON
PRECIPITATION PRIMARILY USING THE HRRR TIMING FOR THE EVENING AND
NAM TIMING FOR LATER TONIGHT AND TOMORROW. THINGS STILL LOOK GOOD
FOR THUNDERSTORM SET UP WEDNESDAY AFTERNOON/EVENING.
PREVIOUS DISCUSSION FOLLOWS...
NEAR 18Z...HAVE WARM FRONT CMH OHIO TO CRW WV
TO NR LNP VA. NICE DIFFERENCE IN CLOUD STRUGGLE ON EITHER SIDE OF
THE FRONT. MORE CELLULAR IN WARM SECTOR IN EASTERN KY.
WILL STILL TRY TO LEAVE SOUTHERN COUNTIES DRY TONIGHT...FIGURING MID
LEVEL CAPE WILL HOLD...DESPITE THE LATE AFTERNOON HEATING AND
INCREASING DEW POINTS.
RAP MODEL INDICATES SOME WEAK 500 MB VORT MAX MOVING ESE THROUGH
EASTERN OHIO INTO NORTH CENTRAL WV 03Z TO 05Z TONIGHT. SO NO BIG
CHANGES IN LEAVING SOME CHANCE POPS THERE TONIGHT. THOUGH...NOT
FIGURING ON STRONG CONVECTION. MAY BE A LULL IN NORTHERN COUNTIES
OVERNIGHT...BUT WITH WNW FLOW ALOFT...HELD ONTO CHANCE POPS FOR NOW.
STILL FIGURING ON A CONVECTION COMPLEX FORMING IN THE MIDWEST
TONIGHT AND RIDING ESE DURING THE 06Z TO 12Z TIME FRAME. WILL HOLD
ONTO INCREASING POPS IN OUR NORTHERN COUNTIES FOR A WEAKENING FORM
OF THAT COMPLEX POSSIBLY REACHING THOSE COUNTIES TOWARD DAWN. SLOWED
DOWN THAT INCREASE BY A FEW HOURS...BUT NEED TO HAVE COMPLEX FORM
BEFORE ANY MAJOR ADJUSTMENT ON TIMING AND HOW FAR SOUTH.
DURING WEDNESDAY...WHAT IS LEFT OF THAT MORNING COMPLEX AND ITS
DEBRIS CLOUDS COULD AFFECT TIMING THE NEW CONVECTION THAT DEVELOPS
ON WEDNESDAY. SO DID NOT WANT TO GET TOO FANCY AT THIS DISTANCE IN
TIME. OVERALL...WE ARE STILL GRADUALLY SHIFTING THE HIGHER POPS
SOUTH DURING THE LATE AFTERNOON. 700 MB MID LEVEL FLOW INCREASES TO
ABOUT 45 KNOTS. THINKING WIND WOULD BE THE HIGHER THREAT ASSOCIATED
WITH THE STRONGER THUNDERSTORMS.
TEMPERATURE WISE...WENT A SHADE COOLER TONIGHT IN THE SOUTH
TONIGHT...FIGURING ON LESS CLOUDS AND THE WIND SUBSIDING A BIT.
NO MAJOR CHANGE IN MAXIMUM TEMPS ON WEDNESDAY SINCE SO DEPENDENT ON
CONVECTION TIMING.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
CONVECTIVELY ACTIVE AT START OF PERIOD WITH COLD FRONT WELL
UPSTREAM...AND WARM ADVECTION SHEAR BENEATH NW FLOW ALOFT. CAPE
VALUES ARE FCST AS HIGH AS 3 KJ/KG OVER THE MID OHIO VALLEY ON DEW
POINTS INTO THE LOWER AND MID 60S...ALONG WITH PW VALUES UP TO 1.5
IN. 40 KT MID LEVEL FLOW SUGGESTS FAST MOVING STORMS SO FLOODING
SHOULD NOT AMOUNT TO MORE THAN BRIEF LOCALIZED HIGH WATER...LEAVING
WIND DAMAGE AS THE MAIN THREAT. FLOW REGIME COULD ALSO SUPPORT AN
ORGANIZED CONVECTIVE COMPLEX MOVING E-SE.
ACTIVITY COULD LAST INTO THE NT AS SOME INSTABILITY IS MAINTAINED
AHEAD OF THE COLD FRONT ADVANCING FROM THE NW...WITH DRIER AIR
INFILTRATING THE AREA LATE WED NT AND THU. COULD THEREFORE STILL
SEE THUNDERSTORMS SRN ZONES THU BUT THE SEVERE THREAT SHOULD BE
DIMINISHED.
HIGH PRESSURE SETTLES IN BENEATH NW FLOW ALOFT THU NT AND FRI.
NO MAJOR TEMPERATURES...WITH MET AND / OR GFS BASED MOS BLENDED IN
IN MOST CASES. INHERITED PACKAGE SHOWED MORE OF A BAROCLINIC ZONE
THAN MOS GUIDANCE SUGGESTS BUT PRESERVED GIVEN MODEL GUIDANCE AS
THIS IS STILL SUGGESTED IN THE MODEL LOW LEVEL THERMAL FIELDS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE RULES AT THE SFC THIS PERIOD WHILE UPPER LEVEL NW FLOW
GIVES WAY TO RIDGING. EXPECT A STRETCH OF DRY WEATHER WITH
MODERATING TEMPERATURES THROUGH THE MEMORIAL DAY WEEKEND. DIURNAL
THUNDERSTORMS START TO BECOME A FACTOR MON OR TUE...HAVE A SLIGHT
CHANCE FOR AFTERNOON THUNDERSTORMS IN THE MOUNTAINS MON
AFTERNOON...AND THEN A CHC EVERYWHERE TUE AFTERNOON.
INHERITED TEMPERATURES LOOKED GOOD...WITH MEX AND / OR WPC BLENDED
IN HERE AND THERE...ALONG WITH CONSENSUS ALL AT THE END. SOME OF
THE GUIDANCE WAS LOWER BUT DID NOT SEE FIT TO LOWER MUCH IN THIS
PATTERN.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
06Z WEDNESDAY THRU 06Z THURSDAY...
THIS WHOLE FORECAST DEPENDS ON THUNDERSTORM COMPLEXES AHEAD OF A
COLD FRONT WHICH DOES NOT ENTER AREA UNTIL AFTER THIS PERIOD.
06Z-15Z. EXPECT ONE COMPLEX NORTHERN INDIANA/NORTHWEST OHIO TO MOVE
EAST SOUTHEAST JUST SOUTH OF WARM FRONT...WITH MOST OF COMPLEX
STAYING JUST NORTH OF AREA. WE DO HAVE SOUTHERN EDGE OF COMPLEX
CLIPPING NORTH CENTRAL AND NORTHEAST WEST VIRGINIA 10Z-15Z...DRY
ELSEWHERE. OUTSIDE OF CONVECTION...GENERALLY VFR CEILINGS AOA 8000
FEET SOUTH AND AROUND 4000 FEET NORTH.
AFTER 15Z...EXPECT ANOTHER THUNDERSTORM COMPLEX TO FORM OUT AHEAD OF
COLD FRONT BY 18Z OVER CENTRAL OHIO...THEN DROPPING SOUTHEAST
THROUGH 00Z INTO SOUTHERN SECTIONS OF AREA. A FEW STORMS COULD BE
SEVERE. AGAIN...OUTSIDE OF CONVECTION CEILINGS AOA 4000 FEET.
AFTER 00Z...EXPECT POST THUNDERSTORM COMPLEX MVFR CEILINGS TO FORM
ESPECIALLY NORTH...WITH DECREASED CHANCES FOR CONVECTION.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM TODAY...LOW TONIGHT.
ALTERNATE SCENARIOS: OCCURRENCE AND TIMING OF CONVECTION...ESPECIALLY
THIS AFTERNOON...ALONG WITH POST COMPLEX MVFR CEILINGS TONIGHT
DEPEND ON THE ACTUAL EVOLUTION OF THE COMPLEXES.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE WED 05/21/14
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H M H H H H H H
PKB CONSISTENCY H H H H H H H H M H H H
CKB CONSISTENCY H H H H H M H H H H H H
AFTER 06Z THURSDAY...
IFR CONDITIONS IN CONVECTION COMPLEXES THROUGH MUCH OF WEDNESDAY
NIGHT...THEN LINGERING IFR IN LOW CLOUDS AND LIGHTER SHOWERS NEAR THE COLD
FRONT 12Z TO 18Z THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/TRM
NEAR TERM...KTB/JR
SHORT TERM...TRM
LONG TERM...TRM
AVIATION...JMV
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
143 AM EDT WED MAY 21 2014
.SYNOPSIS...
A WARM AND MOIST AIRMASS WILL REMAIN IN PLACE OVER THE REGION
TONIGHT. A COLD FRONT WILL PUSH THROUGH THE REGION TOMORROW AND
TOMORROW NIGHT...WITH DRIER AND SLIGHTLY COOLER AIR MOVING OVER
THE OHIO VALLEY FOR THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CONVECTION ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA WILL
LIKELY CONTINUE THROUGH THE NIGHT AND MOVE EAST OR EAST
SOUTHEAST. THIS WILL PUT IT ALONG OR CLOSE TO THE FAR NORTHERN
COUNTIES IN THE FORECAST AREA. SO HAVE CONTINUED TO CONCENTRATE
HIGHER POPS THERE. THERE REMAINS SOME POTENTIAL FOR STRONGER
STORMS INTO WEST CENTRAL OHIO. HOWEVER INSTABILITY WILL DIMINISH A
BIT BY THE TIME STORMS REACH THAT AREA AND BASED ON RAP SOUNDINGS
THE STORMS MAY BE ELEVATED AT THAT POINT. BUT WILL CONTINUE TO
MONITOR THIS POTENTIAL. MEANWHILE THE SOUTHERN COUNTIES SHOULD
REMAIN DRY. FORECAST TEMPERATURES LOOK ON TRACK WITH LOWS IN THE
LOWER TO MID 60S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
LEFTOVER MORNING CONVECTION AND CLOUD DEBRIS WILL END UP PLAYING A
BIG ROLE IN THUNDERSTORM POTENTIAL FOR WEDNESDAY...WITH AN
OTHERWISE-FAVORABLE SETUP FOR STRONG STORMS.
THE WEAK SURFACE LOW WILL GRADUALLY DRIFT EAST ACROSS THE LOWER
PENINSULA OF MICHIGAN ON WEDNESDAY...WITH A COLD FRONT STRETCHING
TO THE SOUTHWEST INTO THE MIDDLE MISSISSIPPI VALLEY. THOUGH THE
FRONTAL BOUNDARY WILL NOT MAKE IT INTO THE ILN CWA UNTIL LATE
WEDNESDAY NIGHT...THE REGIME AHEAD OF THE FRONT WILL BE MOIST AND
UNSTABLE...AND THIS IS WHERE CONVECTION IS EXPECTED TO DEVELOP.
INSTABILITY WILL BE IMPACTED THE GREATEST BY REMNANTS FROM THE
EARLY WEDNESDAY MORNING ACTIVITY...A NEARLY-IMPOSSIBLE QUESTION
TO ANSWER UNTIL THE SITUATION TONIGHT PLAYS OUT. HOWEVER...THE
MOST LIKELY SCENARIO SEEMS TO FAVOR INSTABILITY GROWING THE MOST
IN THE SOUTHERN AND SOUTHWESTERN PORTIONS OF THE ILN CWA...WITH
THE GREATEST IMPEDING TO INSOLATION IN CENTRAL OHIO. HIGH-RES
MODELS ARE NOT KEYING IN ON MUCH STORM DEVELOPMENT IN THE NORTHERN
PORTIONS OF THE CWA...BUT SHOW A GOOD SIGNAL FOR DIURNALLY-TIMED
CONVECTION FIRING OFF IN THE SOUTHERN HALF OF THE FORECAST
AREA...IN AN AREA WHERE CAPE VALUES OF 2000-2500 J/KG APPEAR
POSSIBLE (AS LONG AS THE SUN CAN HEAT THINGS UP FOR A WHILE). WNW
WIND SHEAR IS COMFORTABLY IN THE MODERATE AREA OF THE
SCALE...WHICH WILL SUPPORT STORM ORGANIZATION. ALTHOUGH THERE IS
A LITTLE BIT OF TURNING (WSW AT THE SURFACE TO WNW AT
6KM)...OVERALL THIS SCENARIO SEEMS TO PRIMARILY SUPPORT A WIND AND
HAIL THREAT (PERHAPS WITH SOME DISCRETE AND ORGANIZED UPDRAFTS).
UNLESS CONVECTION COMPLETELY OVERTURNS THE ATMOSPHERE...A THREAT
FOR THUNDERSTORMS MAY CONTINUE INTO THE OVERNIGHT HOURS...WITH
SOME LINGERING INSTABILITY AHEAD OF THE COLD FRONT.
POPS WERE KEPT IN THE 20-30 PERCENT RANGE THROUGH MUCH OF THE DAY
ON WEDNESDAY...BUT RAMPED UP TO LIKELY IN THE SOUTHERN CWA DURING
THE AFTERNOON AND EVENING. POPS WERE DROPPED TO ZERO AFTER 09Z.
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY SLIDE
EASTWARD...BEGINNING TO INFLUENCE THE OHIO VALLEY ON THURSDAY. THE
AIR MASS MOVING IN WILL BE SIGNIFICANTLY DRIER AND SOMEWHAT
COOLER...WITH HIGHS DROPPING 5-10 DEGREES FROM WEDNESDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL ALLOW FOR DRY CONDITIONS THROUGH THE WEEKEND.
COOL NORTHERLY FLOW WILL KEEP TEMPERATURES IN THE UPPER 60S TO LOW
70S ON FRIDAY. A RIDGE WILL GRADUALLY WORK INTO THE REGION THROUGH
THE WEEKEND WITH TEMPERATURES WARMING EACH DAY. BY MONDAY HIGH
TEMPERATURES ARE EXPECTED TO BE IN THE 80S ACROSS THE ENTIRE FA.
PRECIPITATION LOOKS TO HOLD OFF UNTIL TUESDAY. THE GFS IS TRYING TO
DEVELOP A FEW THUNDERSTORMS ACROSS NW PORTIONS OF THE FA ON MONDAY
HOWEVER DECIDED TO GO WITH A DRY FORECAST ON MONDAY AT THIS TIME.
ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE DURING THE DAY
ON TUESDAY. ANY THUNDERSTORM ACTIVITY IS EXPECTED TO DISSIPATE
DURING THE EVENING HOURS WITH THE LOSS OF DAYTIME HEATING.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
THUNDERSTORMS ARE CONTINUING TO PUSH EAST ACROSS NORTHERN INDIANA
AND ARE NOW WORKING INTO NORTHWEST OHIO EARLY THIS MORNING. THESE
STORMS HAVE HAD A BIT OF A SOUTHEASTWARD PROPAGATION TO THEM...BUT
AIRMASS FARTHER SOUTH ACROSS OUR AREA IS MORE STABLE. AS A
RESULT...THINK THESE WILL GENERALLY REMAIN TO THE NORTH OF THE TAF
SITES THROUGH THE PRE DAWN HOURS. THAT BEING SAID...THE LATEST HI-RES
MODELS ARE IN DECENT AGREEMENT SHOWING SOME DEVELOPMENT FROM AN
OUTFLOW OF THE CURRENT ACTIVITY...DROPPING SOUTH ACROSS OUR AREA
LATER THIS MORNING INTO THIS AFTERNOON. HOW WIDESPREAD THIS
ACTIVITY WILL BE IS STILL SOMEWHAT IN DOUBT THOUGH SO WILL CONTINUE
TO COVER THE THREAT WITH A VCTS AT THE NORTHERN TAF SITES LATER
THIS MORNING. AS WE BEGIN TO DESTABILIZE THROUGH THIS
AFTERNOON...EXPECT COVERAGE TO INCREASE AS THE BOUNDARY SAGS SOUTH
TOWARD THE OHIO RIVER. THIS WILL LIKELY LEAD TO A BETTER CHANCE OF
THUNDERSTORMS AT THE SOUTHERN TAF SITES FOR THIS AFTERNOON INTO THIS
EVENING. HAVE KEPT CIGS AND VSBYS VFR...BUT BRIEF PERIODS OF MVFR
OR LOWER CIGS/VSBYS WILL BE POSSIBLE WITH ANY STORMS THAT AFFECT
THE TAF SITES.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...
SHORT TERM...HATZOS
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
156 AM EDT WED MAY 21 2014
.SYNOPSIS...
A WARM FRONT WILL SLIDE FROM THE OHIO VALLEY INTO CENTRAL
PENNSYLVANIA TONIGHT AND WEDNESDAY. A COLD FRONT WILL THEN MOVE
THROUGH ON THURSDAY...BRINGING COOLER AIR BACK TO THE REGION. THE
EXTENDED FORECAST INDICATES A GRADUAL WARMING TREND BEGINNING THIS
WEEKEND DESPITE SOME SHOWERS LINGERING IN THE POST- FRONTAL
NORTHWEST FLOW.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
130 AM UPDATE...
MIGHT AS WELL JUST BLOCK COPY PASTE FROM THE EARLIER DISC.
HOWEVER...THE STORMS MOVING INTO NWRN COS ARE MUCH STRONGER THAN
EARLIER - DESPITE STILL BEING ELEVATED/DETACHED FROM THE SURFACE.
THESE ALSO SEEM TO HAVE BETTER UPPER SUPPORT AND SHOULD LAST
LONGER AND DROP MORE RAIN. THEREFORE...HAVE FURTHER BUMPED POPS
UP AND EXTENDED THEM INTO THE SERN COS LATER TONIGHT. LATEST RUC
AND HRRR PROGS SUPPORT THIS MOVE. DEWPOINTS STILL IN THE 40S OVER
THE LAURELS AND FAR NERN COS WHERE NO RAIN HAS YET FALLEN.
PREV...
THE BACK EDGE OF THE CONVECTION SEEMS TO BE ON THE LAKE ERIE
SHORE-LINE NOW...MAKING A BEE-LINE FOR NW PA WITH STILL AN
OCCASIONAL LIGHTNING STRIKE STILL BEING DISPLAYED.
HOWEVER THE 23Z HRRR KEEPS THIS ZONE ACTIVE INTO THE OVERNIGHT AS
THE WARM FRONT PROGRESSES SLOWLY EAST. I RAMPED UP THE POPS AND
EXPANDED THE COVERAGE AS EARLIER MODEL OUTPUT REALLY DOWNPLAYED
THE AREAL COVERAGE OF THE SHOWERS. NEW MESO MODELS SEEM TO BE
FINALLY CATCHING UP.
WITH CLOUDS IN PLACE AND WEAK SOUTHERLY FLOW...A MILD NIGHT IN
STORE WITH TEMPS ONLY FALLING INTO THE 50S.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM THURSDAY/...
SHORTWAVE SLIDES SE OVER THE WARM FRONT ON WED...BRINGING SOME
BETTER DYNAMICS TO CENTRAL PA. BEST INSTABILITY/LIFT REMAINS OFF
TO OUR WEST THOUGH...AND PRIMARY THREAT OF SVR WEATHER WILL
REMAIN CONFINED TO THOSE REGIONS...BUT SOME STRONGER TSTORMS MAY
SLIP EASTWARD TOWARD OUR WESTERN BORDER LATER WED AS WARM SECTOR
WORKS NE AND MID LEVEL WINDS APPROACH 50 KTS. OVERALL
THOUGH...EXPECTING A SHOWERY DAY WITH SCT TSTORMS.
COLD FRONT FOLLOWS WED NIGHT/EARLY THU...WITH ANOTHER ROUND OF SCT
SHOWERS. THE UPPER LOW DRIVING THIS WHOLE CONVOLUTED SYSTEM WILL
THEN RESIDE OVER NEW ENGLAND FOR A DAY OR SO. THIS WILL KEEP THE
WX COOLER AND UNSETTLED FOR THE REST OF THE WEEK.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
RIDGE-TOPPING SHORTWAVE TROUGH IS EXPECTED TO AMPLIFY/DIG SEWD FROM
THE UPPER GREAT LAKES REGION ACROSS THE NORTHERN MID-ATLC AND
INTERIOR NORTHEAST STATES D3-4. THE UPPER LOW EXITING NORTHERN NEW
ENGLAND WILL ANCHOR A MEAN TROUGH ALONG/OFFSHORE THE EAST COAST SAT-
SUN BEFORE BEING REPLACED BY A GRADUALLY BUILDING HIGH-LEVEL RIDGE
D6-8.
THE 20/00Z AND 20/12Z MODEL AND ENSEMBLE CYCLES CONTINUE TO HANDLE
THE 500MB HEIGHT PATTEN ACROSS THE CONUS REASONABLY WELL THROUGH THE
UPCOMING WEEKEND. THE BULK OF THE UNCERTAINTY IN THE MID-UPPER
LEVEL FLOW AFTER DAY 6 RESIDES OVER THE WESTERN 1/3 OF NOAM.
SENSIBLE WEATHER HIGHLIGHTS...SCT SHWRS W/ISOLD TSTMS SHOULD
ACCOMPANY SFC COLD FRONT THRU CNTRL/RN PA EARLY THURS. THE FRONTAL
PASSAGE WILL BRIEFLY RETURN THE RECENT COOL/DRY CYC FLOW PATTERN
ALOFT WITH DIURNAL/INSTABILITY SHOWERS ASSOCD WITH INDIVIDUAL
SHORTWAVE IMPULSES ROTATING AROUND THE BACKSIDE OF THE DEPARTING
UPPER LEVEL TROUGH. A MID-LEVEL ANTICYCLONE BUILDING NORTH/EAST FROM
THE LWR MS VLY WILL PRODUCE A MORE TYPICAL EARLY-SUMMER PATTERN WITH
STRONG SIGNALS FOR AN UPWARD TREND IN TEMPERATURE/HUMIDITY FROM
MEMORIAL DAY INTO THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
STRONG THUNDERSTORM OVER SW NY HAS WEAKEN...BUT MORE DROPPING
SE FROM LAKE ERIE. AREA OF COOLING TOPS...AND MODELS SHOW
THIS AREA DROPPING SE ACROSS S PA.
THUS ADDED THUNDER TO THE 06Z PACKAGE.
BY MID TO LATE MORNING...THIS ACTIVITY SHOULD BE SOUTH
OF OUR AREA...THUS WENT WITH VFR CONDITIONS.
STILL STRONG DIRECTIONAL SHEAR AND WARM ADVECTION...THUS
WILL HAVE TO ADJUST THE TAFS FOR ANY ADDITIONAL STORMS
LATER TODAY. FOR NOW...LEFT THINGS VFR AFTER 00Z THU.
SOME SHOWERS COULD PERSIST INTO THE WEEKEND...AS ADDITIONAL
ENERGY ROTATES AROUND A DEEP UPPER LEVEL LOW.
BEST DAY FOR DRY WEATHER AND VFR CONDITIONS WILL BE SUNDAY.
.OUTLOOK...
THU...EARLY AM FOG/LOW CIGS POSS...MAINLY W MTNS.
FRI-SAT...MAINLY VFR. SCT SHOWERS POSS MAINLY N AND W WITH LOCAL
RESTRICTIONS.
SUN...NO RESTRICTIONS EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...DANGELO/LA CORTE
SHORT TERM...RXR
LONG TERM...STEINBUGL
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
131 AM EDT WED MAY 21 2014
.SYNOPSIS...
A WARM FRONT WILL SLIDE FROM THE OHIO VALLEY INTO CENTRAL
PENNSYLVANIA TONIGHT AND WEDNESDAY. A COLD FRONT WILL THEN MOVE
THROUGH ON THURSDAY...BRINGING COOLER AIR BACK TO THE REGION. THE
EXTENDED FORECAST INDICATES A GRADUAL WARMING TREND BEGINNING THIS
WEEKEND DESPITE SOME SHOWERS LINGERING IN THE POST- FRONTAL
NORTHWEST FLOW.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
130 AM UPDATE...
MIGHT AS WELL JUST BLOCK COPY PASTE FROM THE EARLIER DISC.
HOWEVER...THE STORMS MOVING INTO NWRN COS ARE MUCH STRONGER THAN
EARLIER - DESPITE STILL BEING ELEVATED/DETACHED FROM THE SURFACE.
THESE ALSO SEEM TO HAVE BETTER UPPER SUPPORT AND SHOULD LAST
LONGER AND DROP MORE RAIN. THEREFORE...HAVE FURTHER BUMPED POPS
UP AND EXTENDED THEM INTO THE SERN COS LATER TONIGHT. LATEST RUC
AND HRRR PROGS SUPPORT THIS MOVE. DEWPOINTS STILL IN THE 40S OVER
THE LAURELS AND FAR NERN COS WHERE NO RAIN HAS YET FALLEN.
PREV...
THE BACK EDGE OF THE CONVECTION SEEMS TO BE ON THE LAKE ERIE
SHORE-LINE NOW...MAKING A BEE-LINE FOR NW PA WITH STILL AN
OCCASIONAL LIGHTNING STRIKE STILL BEING DISPLAYED.
HOWEVER THE 23Z HRRR KEEPS THIS ZONE ACTIVE INTO THE OVERNIGHT AS
THE WARM FRONT PROGRESSES SLOWLY EAST. I RAMPED UP THE POPS AND
EXPANDED THE COVERAGE AS EARLIER MODEL OUTPUT REALLY DOWNPLAYED
THE AREAL COVERAGE OF THE SHOWERS. NEW MESO MODELS SEEM TO BE
FINALLY CATCHING UP.
WITH CLOUDS IN PLACE AND WEAK SOUTHERLY FLOW...A MILD NIGHT IN
STORE WITH TEMPS ONLY FALLING INTO THE 50S.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM THURSDAY/...
SHORTWAVE SLIDES SE OVER THE WARM FRONT ON WED...BRINGING SOME
BETTER DYNAMICS TO CENTRAL PA. BEST INSTABILITY/LIFT REMAINS OFF
TO OUR WEST THOUGH...AND PRIMARY THREAT OF SVR WEATHER WILL
REMAIN CONFINED TO THOSE REGIONS...BUT SOME STRONGER TSTORMS MAY
SLIP EASTWARD TOWARD OUR WESTERN BORDER LATER WED AS WARM SECTOR
WORKS NE AND MID LEVEL WINDS APPROACH 50 KTS. OVERALL
THOUGH...EXPECTING A SHOWERY DAY WITH SCT TSTORMS.
COLD FRONT FOLLOWS WED NIGHT/EARLY THU...WITH ANOTHER ROUND OF SCT
SHOWERS. THE UPPER LOW DRIVING THIS WHOLE CONVOLUTED SYSTEM WILL
THEN RESIDE OVER NEW ENGLAND FOR A DAY OR SO. THIS WILL KEEP THE
WX COOLER AND UNSETTLED FOR THE REST OF THE WEEK.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
RIDGE-TOPPING SHORTWAVE TROUGH IS EXPECTED TO AMPLIFY/DIG SEWD FROM
THE UPPER GREAT LAKES REGION ACROSS THE NORTHERN MID-ATLC AND
INTERIOR NORTHEAST STATES D3-4. THE UPPER LOW EXITING NORTHERN NEW
ENGLAND WILL ANCHOR A MEAN TROUGH ALONG/OFFSHORE THE EAST COAST SAT-
SUN BEFORE BEING REPLACED BY A GRADUALLY BUILDING HIGH-LEVEL RIDGE
D6-8.
THE 20/00Z AND 20/12Z MODEL AND ENSEMBLE CYCLES CONTINUE TO HANDLE
THE 500MB HEIGHT PATTEN ACROSS THE CONUS REASONABLY WELL THROUGH THE
UPCOMING WEEKEND. THE BULK OF THE UNCERTAINTY IN THE MID-UPPER
LEVEL FLOW AFTER DAY 6 RESIDES OVER THE WESTERN 1/3 OF NOAM.
SENSIBLE WEATHER HIGHLIGHTS...SCT SHWRS W/ISOLD TSTMS SHOULD
ACCOMPANY SFC COLD FRONT THRU CNTRL/RN PA EARLY THURS. THE FRONTAL
PASSAGE WILL BRIEFLY RETURN THE RECENT COOL/DRY CYC FLOW PATTERN
ALOFT WITH DIURNAL/INSTABILITY SHOWERS ASSOCD WITH INDIVIDUAL
SHORTWAVE IMPULSES ROTATING AROUND THE BACKSIDE OF THE DEPARTING
UPPER LEVEL TROUGH. A MID-LEVEL ANTICYCLONE BUILDING NORTH/EAST FROM
THE LWR MS VLY WILL PRODUCE A MORE TYPICAL EARLY-SUMMER PATTERN WITH
STRONG SIGNALS FOR AN UPWARD TREND IN TEMPERATURE/HUMIDITY FROM
MEMORIAL DAY INTO THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
SHOWERS CONTINUE TO TO INCREASE AS THEY ARE STREAMING ACROSS THE
NORTH EASTERN HALF OF PENNSYLVANIA THIS EVENING. THIS HAS ALLOWED
FOR BRIEF IFR CONDITIONS AT BFD...AND POSSIBLE MVFR AT IPT. THESE
SHOWERS ARE LIGHT IN GENERAL...BUT EMBEDDED HEAVY SHOWERS COULD
ALLOW FOR BRIEF MVFR TO IFR CIGS AND VSBYS AS THE SYSTEM MOVES IN
OVERNIGHT. THE SHOWERS HAVE ALSO ALLOWED FOR THE SFC TO BE MIXED
AND CAUSED GUSTY WINDS AT UNV. THESE WINDS WILL SUBSIDE BETWEEN 06
TO 08Z AS THE SFC DECOUPLES.
SHOWER ACTIVITY WILL PICK UP AS THE NIGHT PROGRESSES AND THROUGH TOMORROW
AS A WARM FRONT MOVES ACROSS THE REGION. THIS WILL BE QUICKLY FOLLOWED
BY A COLD FRONT ON THURSDAY. SCT THUNDERSTORMS WILL ALSO IMPACT
CENTRAL PA...MAINLY DURING THE DAY TOMORROW...WITH A FEW STRONG
STORMS POSS ACROSS THE NORTH AND WEST LATER WED INTO WED EVE.
LOWERING CIGS WILL SLIDE IN FROM THE NORTHWEST LATE TONIGHT AND
MAY BRING RESTRICTIONS INTO THE CENTRAL MTNS FOR MUCH OF WED. THE
SE SHOULD REMAIN MAINLY VFR...EXCEPT FOR LOCALIZED TSTORM IMPACTS.
.OUTLOOK...
WED...AM FOG/LOW CIGS LIKELY NORTHERN/CENTRAL MTNS. SCT MAINLY PM
TSRA IMPACTS POSS.
THU...EARLY AM FOG/LOW CIGS POSS...MAINLY W MTNS.
FRI-SAT...MAINLY VFR. SCT SHOWERS POSS MAINLY N AND W WITH LOCAL
RESTRICTIONS.
SUN...NO RESTRICTIONS EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...DANGELO/LA CORTE
SHORT TERM...RXR
LONG TERM...STEINBUGL
AVIATION...CERU/RXR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
837 PM MDT THU MAY 22 2014
.UPDATE...
ISSUED AT 831 PM MDT THU MAY 22 2014
CONVECTION OVER NERN WY IS MOSTLY LOCATED NEAR THE MT BORDER...AND
IS DIMINISHING SO HAVE ADJUSTED POPS OVER THAT AREA ACCORDINGLY.
WILL KEEP LOW POPS IN THE FCST FOR THE SD PLAINS LATER TONIGHT
GIVEN ENERGY PROPAGATING NWD FROM NERN CO.
UPDATE ISSUED AT 523 PM MDT THU MAY 22 2014
RAISED POPS FOR NERN WY AND AROUND THE NRN PERIPHERY OF THE BLKHLS
FOR THIS EVE BASED ON RADAR OBSERVATIONS.
&&
.SHORT TERM...THIS EVENING THROUGH FRIDAY NIGHT
ISSUED AT 230 PM MDT THU MAY 22 2014
CURRENT SURFACE MAP PLACES HIGH PRESSURE ACROSS MINNESOTA...WITH
RETURN FLOW ACROSS THE HIGH PLAINS. UPPER LOW CONTINUES TO SPIN
ACROSS THE SOUTHWESTERN U.S. WITH RIDGE AXIS ACROSS THE NORTHERN
PLAINS. MLCAPE AROUND 1000 J/KG ACROSS NORTHEAST WYOMING/FAR
WESTERN SOUTH DAKOTA...HOWEVER WEAK CAP AND LACK OF FORCING HAS
KEPT THUNDERSTORM DEVELOPMENT ACROSS THE BLACK HILLS. MARGINAL
SHEAR FOR ROTATING UPDRAFTS. VERY SLOW STORM MOVEMENT. MAIN
THREAT THROUGH THIS EVENING WILL BE SMALL HAIL AND LOCALLY HEAVY
RAINFALL. LATEST RUN OF THE HRRR KEEPS SOME THUNDERSTORM ACTIVITY
ACROSS NORTHEAST WYOMING/WESTERN SOUTH DAKOTA UNTIL AFTER
MIDNIGHT.
SIMILAR SETUP ACROSS THE AREA FOR FRIDAY. MAIN DIFFERENCE WILL BE
STRONGER SHORTWAVE LIFTING NORTHWARD THROUGH WYOMING/WESTERN
NEBRASKA FRIDAY AFTERNOON. WITH STRONGER FORCING...MORE WIDESPREAD
THUNDERSTORM ACTIVITY FRIDAY AFTERNOON/EVENING. SHEAR A LITTLE
STRONGER...SO A FEW SEVERE HAIL STORMS POSSIBLE. SLOW MOVEMENT AND
HIGH PRECIPITABLE WATER WILL RESULT IN LOCALLY HEAVY RAINFALL.
&&
.LONG TERM...SATURDAY THROUGH THURSDAY
ISSUED AT 230 PM MDT THU MAY 22 2014
SOUTHWEST FLOW ALOFT REMAINS ACROSS THE REGION THIS WEEKEND...WITH
SEVERAL SHORTWAVE DISTURBANCES EJECTING OUT OF A PERSISTENT TROF/CUT
OFF LOW OVER THE WESTERN UNITED STATES. CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE SATURDAY AND SUNDAY...WITH THE POTENTIAL
FOR A FEW STRONG TO SEVERE STORMS EACH DAY. MEDIUM RANGE MODELS
CONTINUE TO SHOW SOMEWHAT GOOD AGREEMENT ON THE TRACK AND TIMING OF
UPPER LOW AS IT FINALLY MOVES FROM THE SOUTHWEST CONUS INTO THE
CENTRAL PLAINS LATE THROUGH THE HOLIDAY WEEKEND. CHANCES FOR PCPN
SHOULD DECREASE ACROSS MUCH OF THE AREA BY MONDAY AS THE LOW TRACKS
SOUTH AND EAST OF THE REGION. CHANCES FOR PCPN COULD INCREASE AGAIN
FOR THE SECOND HALF OF THE WEEK AS FLOW ALOFT RETURNS TO THE
SOUTHWEST. TEMPERATURES WILL BE A BIT ABOVE AVERAGE THROUGH THE
PERIOD...WITH HIGHS IN THE 70S AND LOWER 80S ON THE PLAINS...60S AND
LOWER 70S ACROSS THE BLACK HILLS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 831 PM MDT THU MAY 22 2014
SCT TSTMS ACRS NERN WY WILL CONTINUE TO DIMINISH EARLY THIS
EVE...ALTHOUGH SOME IFR CONDITIONS DUE TO HEAVY RAIN ARE STILL
POSSIBLE NEAR THE MT BORDER THROUGH 04Z. OTHERWISE...VFR
CONDITIONS EXPECTED WITH ISOLATED HIGH BASED TSTMS POSSIBLE
OVERNIGHT. SCT TSTMS EXPECTED TO DEVELOP AGAIN FRIDAY AFTN.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...JOHNSON
SHORT TERM...7
LONG TERM...13
AVIATION...JOHNSON
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
529 PM MDT THU MAY 22 2014
.UPDATE...
ISSUED AT 523 PM MDT THU MAY 22 2014
RAISED POPS FOR NERN WY AND AROUND THE NRN PERIPHERY OF THE BLKHLS
FOR THIS EVE BASED ON RADAR OBSERVATIONS.
&&
.SHORT TERM...THIS EVENING THROUGH FRIDAY NIGHT
ISSUED AT 230 PM MDT THU MAY 22 2014
CURRENT SURFACE MAP PLACES HIGH PRESSURE ACROSS MINNESOTA...WITH
RETURN FLOW ACROSS THE HIGH PLAINS. UPPER LOW CONTINUES TO SPIN
ACROSS THE SOUTHWESTERN U.S. WITH RIDGE AXIS ACROSS THE NORTHERN
PLAINS. MLCAPE AROUND 1000 J/KG ACROSS NORTHEAST WYOMING/FAR
WESTERN SOUTH DAKOTA...HOWEVER WEAK CAP AND LACK OF FORCING HAS
KEPT THUNDERSTORM DEVELOPMENT ACROSS THE BLACK HILLS. MARGINAL
SHEAR FOR ROTATING UPDRAFTS. VERY SLOW STORM MOVEMENT. MAIN
THREAT THROUGH THIS EVENING WILL BE SMALL HAIL AND LOCALLY HEAVY
RAINFALL. LATEST RUN OF THE HRRR KEEPS SOME THUNDERSTORM ACTIVITY
ACROSS NORTHEAST WYOMING/WESTERN SOUTH DAKOTA UNTIL AFTER
MIDNIGHT.
SIMILAR SETUP ACROSS THE AREA FOR FRIDAY. MAIN DIFFERENCE WILL BE
STRONGER SHORTWAVE LIFTING NORTHWARD THROUGH WYOMING/WESTERN
NEBRASKA FRIDAY AFTERNOON. WITH STRONGER FORCING...MORE WIDESPREAD
THUNDERSTORM ACTIVITY FRIDAY AFTERNOON/EVENING. SHEAR A LITTLE
STRONGER...SO A FEW SEVERE HAIL STORMS POSSIBLE. SLOW MOVEMENT AND
HIGH PRECIPITABLE WATER WILL RESULT IN LOCALLY HEAVY RAINFALL.
&&
.LONG TERM...SATURDAY THROUGH THURSDAY
ISSUED AT 230 PM MDT THU MAY 22 2014
SOUTHWEST FLOW ALOFT REMAINS ACROSS THE REGION THIS WEEKEND...WITH
SEVERAL SHORTWAVE DISTURBANCES EJECTING OUT OF A PERSISTENT TROF/CUT
OFF LOW OVER THE WESTERN UNITED STATES. CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE SATURDAY AND SUNDAY...WITH THE POTENTIAL
FOR A FEW STRONG TO SEVERE STORMS EACH DAY. MEDIUM RANGE MODELS
CONTINUE TO SHOW SOMEWHAT GOOD AGREEMENT ON THE TRACK AND TIMING OF
UPPER LOW AS IT FINALLY MOVES FROM THE SOUTHWEST CONUS INTO THE
CENTRAL PLAINS LATE THROUGH THE HOLIDAY WEEKEND. CHANCES FOR PCPN
SHOULD DECREASE ACROSS MUCH OF THE AREA BY MONDAY AS THE LOW TRACKS
SOUTH AND EAST OF THE REGION. CHANCES FOR PCPN COULD INCREASE AGAIN
FOR THE SECOND HALF OF THE WEEK AS FLOW ALOFT RETURNS TO THE
SOUTHWEST. TEMPERATURES WILL BE A BIT ABOVE AVERAGE THROUGH THE
PERIOD...WITH HIGHS IN THE 70S AND LOWER 80S ON THE PLAINS...60S AND
LOWER 70S ACROSS THE BLACK HILLS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 523 PM MDT THU MAY 22 2014
SCT TSTMS...MAINLY ACRS NERN WY AND THE BLKHLS AREA THIS
EVE...WILL PRODUCE AREAS OF IFR CONDITIONS WITH SMALL HAIL AND
HEAVY RAIN. EXPECT MOST ACTIVITY TO DECREASE BY MID/LATE EVENING.
VFR CONDITIONS WILL CONTINUE OUTSIDE OF ANY TSTM ACTIVITY. SCT
TSTMS EXPECTED AGAIN FRIDAY AFTN.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...JOHNSON
SHORT TERM...7
LONG TERM...13
AVIATION...JOHNSON
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
240 PM MDT WED MAY 21 2014
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 226 PM MDT WED MAY 21 2014
CURRENT SURFACE MAP PLACES HIGH PRESSURE ACROSS THE EASTERN
DAKOTAS. PERSISTENT LOW CLOUDS ACROSS NORTHEAST WYOMING HAS
LIMITED SURFACE BASED INSTABILITY. THUNDERSTORMS DEVELOPING OVER
EAST CENTRAL WYOMING INTO COLORADO. LATEST RADAR TRENDS AND
CURRENT RUN OF HRRR BRINGS THUNDERSTORMS INTO NORTHEAST
WYOMING/FAR SOUTHWEST SOUTH DAKOTA THIS EVENING. THUNDERSTORMS
SHOULD PERSIST OVERNIGHT ACROSS WESTERN SOUTH DAKOTA WITH WEAK
850-700MB THETA-E ADVECTION AND STEEP MID LEVEL LAPSE RATES.
HIGH MOVES EAST FOR THURSDAY...WITH INSTABILITY AXIS CREEPING
FURTHER NORTHWARD. WITH LACK OF LARGE SCALE FORCING UNDER UPPER
RIDGE AXIS...THUNDERSTORM ACTIVITY MAY BE LIMITED TO THE HIGHER
TERRAIN OF NORTHEAST WYOMING INTO THE BLACK HILLS.
&&
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 226 PM MDT WED MAY 21 2014
SOUTHWEST FLOW ALOFT REMAINS ACROSS THE REGION LATE THIS WEEK INTO
THE WEEKEND...WITH SEVERAL SHORTWAVE DISTURBANCES EJECTING OUT OF A
PERSISTENT TROF/CUT OFF LOW OVER THE WESTERN UNITED STATES. AN
ACTIVE AND UNSETTLED WEATHER PATTERN WILL CONTINUE...WITH DAILY
CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH MUCH OF THE PERIOD.
MEDIUM RANGE MODELS CONTINUE TO SHOW GOOD AGREEMENT ON THE TRACK AND
TIMING OF UPPER LOW AS IT MOVES FROM THE SOUTHWEST CONUS INTO THE
CENTRAL PLAINS LATER IN THE HOLIDAY WEEKEND. CHANCES FOR PCPN SHOULD
DECREASE BY MONDAY AS THE LOW TRACKS SOUTH AND EAST OF THE AREA.
TEMPERATURES WILL GENERALLY BE A BIT ABOVE AVERAGE THROUGH THE
PERIOD...WITH HIGHS MOSTLY IN THE 70S ON THE PLAINS...60S AND LOWER
70S ACROSS THE BLACK HILLS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY)
ISSUED AT 226 PM MDT WED MAY 21 2014
CHANCES FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS MUCH OF
THE FORECAST AREA THROUGH TONIGHT. MVFR CONDITIONS AND GUSTY WINDS
ARE POSSIBLE IN THE VICINITY OF ANY HEAVIER SHOWERS. OTHERWISE AREAS
OF MVFR CIGS NOW OVER NE WY INTO PORTIONS OF FAR WRN SD WILL LINGER
TONIGHT INTO THURSDAY MORNING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...47
LONG TERM...13
AVIATION...13
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
735 PM CDT THU MAY 22 2014
.UPDATE...
HAVE REMOVED REMAINDER OF COUNTIES FROM SEVERE THUNDERSTORM WATCH
AS ALL CONVECTION HAS EXITED THE AREA. RADAR INDICATES OUTFLOW
BOUNDARY/EFFECTIVE COLD FRONT EXTENDS FROM NEAR DOVER TO JUST
NORTH OF NASHVILLE TO NEAR SPENCER...AND VISIBLE SATELLITE IMAGERY
SHOWS TOWERING CUMULUS CONTINUES ALONG BOUNDARY FROM CLARKSVILLE
WESTWARD INTO WESTERN KY AND MO. THUS SOME ADDITIONAL SHOWERS AND
STORMS COULD YET STILL FORM THIS EVENING AND MOVE ACROSS THE
NORTHERN HALF OF THE CWA...AS LATEST HRRR RUNS SUGGEST.
INDEED...LATEST RADAR MOSAIC IMAGERY SHOWS SHOWERS DEVELOPING IN
SE MO ATTM. HAVE ADJUSTED POPS FOR THE REST OF TONIGHT TO SHOW A
SLIGHT CHANCE ALONG AND NORTH OF A ERIN TO ALTAMONT LINE. WILL
ALSO MENTION PATCHY FOG IN SAME AREA DUE TO THE MOIST LOW
LEVELS...BUT FOG WILL BE MOST LIKELY ON THE NORTHERN PLATEAU WHERE
RAIN COOLED AIR HAS SATURATED THE BL. ALSO ADJUSTED TEMPS AND LOWS
FOR TONIGHT BASED ON LATEST OBS. REST OF FORECAST LOOKS TO BE ON
TRACK.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 641 PM CDT THU MAY 22 2014/
UPDATE...
ONE LONE CELL EXISTS JUST NORTH OF THE DOVER AREA BUT IT APPEARS
TO BE WEAKENING. ELSEWHERE...STILL A FEW RESIDUAL TSTMS ACROSS THE
PLATEAU BUT THEY TOO HAVE WEAKENED. INSTABILITY PARAMETERS REMAIN
ELEVATED BUT OVERALL FORCING LEVELS HAVE LESSENED.
FOR THE UPDATE...WILL REMOVE THE WATCH FROM AREAS WEST OF THE
PLATEAU BUT WILL ALLOW THE WATCH ACROSS THE PLATEAU TO CONTINUE
FOR A LITTLE LONGER. WILL ALSO MAKE ADJUSTMENTS TO THE SKY GRIDS
AND WILL LOWER POPS. UPDATE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 630 PM CDT THU MAY 22 2014/
AVIATION 00Z DISCUSSION...
CONVECTION ASSOCIATED WITH THE COLD FRONT WILL EFFECT PRIMARILY
THE CSV AREA THROUGH 03Z. ELSEWHERE...CHANCES FOR TSTM REDEVELOPMENT
ARE MUCH LOWER. BUT...A SEVERE TSTM WATCH DOES REMAIN IN EFFECT
FOR THE TERMINAL AREAS UNTIL 10 PM CDT. OTW...SOME LOWER CIGS ARE
EXPECTED LATER TONIGHT ALONG WITH SOME FOG TOWARD 12Z. PARTIAL
CLEARING WILL TAKE PLACE AFT 14Z OR SO. ISOL CONVECTION WILL THEN
BE POSSIBLE AFT 18Z.
PREV DISCUSSION... /ISSUED 321 PM CDT THU MAY 22 2014/
DISCUSSION...
FRONTAL BOUNDARY RESIDES ACROSS CENTRAL KY IN A W-E FASHION. IT IS
ACROSS THIS AREA WHERE THE ADDED FORCING HAS BROKEN THROUGH THE
CAP. THIS TREND SHOULD CONTINUE AND THE MID LEVEL FLOW SUGGESTS A
SOUTHEASTWARD MOVEMENT. MAY LIKELY INCLUDE A PRE 1ST PERIOD ZONE
GROUP AS THE EXPECTED CONVECTION WILL END EARLY THIS EVENING
ACROSS NW ZONES. ACROSS NORTHEASTERN AREAS...THE CONVECTION COULD
CONTINUE INTO THE EVENING. AS FOR THE SEVERE POTENTIAL...MUCH OF
THE MID STATE IS STILL UNDER A SLIGHT RISK...AND THAT HAS NOW BEEN
UPGRADED TO A SEVERE TSTM WATCH FOR MUCH OF THE NORTHERN TWO
THIRDS OF THE MID STATE UNTIL 10 PM. DEW POINTS HAVE SLOWLY RISEN
DURING THE DAY SO THE INSTABILITY LEVELS ARE ON THE INCREASE.
SOUTH OF THE BOUNDARY HOWEVER...WE ARE PICKING UP SOME SUBSIDENCE
IN THE LOWER LEVELS AND ITS FURTHER NORTH...NEAR THE FRONT...WHERE
THE FORCING RESIDES. CAPES ARE QUITE IMPRESSIVE THIS AFTERNOON AND
TSTMS WITH LARGE HAIL AND OR HIGH WIND GUSTS WILL BE POSSIBLE.
FOR TONIGHT...POPS WILL BE KEPT WITHIN THE CHANCE CATEGORY WITH
NO POPS FAR SOUTHWEST.
ON FRIDAY...THE COLD FRONT WILL BE POSITIONED ACROSS OUR SOUTHERN
COUNTIES. CAP WILL AGAIN DIMINISH TOWARD 18Z WITH ENHANCED CAPE
VALUES...ESPECIALLY NEAR THE FRONT. WILL AGAIN INCLUDE A SLIGHT
CHANCE OF SHOWERS AND TSTMS.
ON SATURDAY...SFC HIGH TO OUR NORTH WILL PREVAIL WITH A NE SFC FLOW.
UPPER RIDGE WILL BE ATTEMPTING TO DEVELOP TO OUR WEST. SOME LOWER
LEVEL MOISTURE ENHANCEMENT WILL ATTEMPT TO MAKE A RUN AT US AS WELL.
BUT OVERALL INSTABILITY PARAMETERS LOOK TOO LOW AT THIS TIME TO
SUPPORT POPS.
FOR THE NEAR TERM TEMPS...LOW LEVEL MOISTURE ON THE TIME HEIGHT
PROFILES TENDS TO SUPPORT GOING A DEGREE OR TWO ABOVE MINS.
OTW...GUIDANCE FOR HIGHS LOOKS TO BE ON TRACK.
IN THE EXTENDED FCST...A SMALL SCALE BUT APPARENT UPPER RIDGE WILL
MOVE ACROSS OUR AREA MONDAY AND TUESDAY. GFS HINTS TOWARD A FEW
DEVELOPMENTAL BOUNDARIES UNDERNEATH THE RIDGE. AFTERNOON CAPES ARE
IN PLACE EACH DAY WITH CAPS DIMINISHING TOWARD 18Z. UPPER LEVEL AND
MOISTURE COMPONENTS NOT IN SUPPORT OF ANY WELL ORGANIZED SYSTEMS.
THEREFORE...THIS LOOKS LIKE A MORE TYPICAL SUMMERTIME PATTERN WITH
WEAK FEATURES BUT A SUSTAINED UNSTABLE PATTERN EACH AFTERNOON. WILL
OPT TO CONTINUE WITH THE LOW POP CHANCES.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
55
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
252 PM EDT WED MAY 21 2014
.SHORT TERM (TONIGHT THROUGH THURSDAY)... SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO DEVELOP NORTH OF OUR AREA IN THE NEXT FEW
HOURS...SUPPORTED BY UPPER DIVERGENCE AND A 500 MB VORT MAX.
COVERAGE SHOULD BE MAINLY SCATTERED DUE TO LIMITED MOISTURE ACROSS
THE REGION. THIS ACTIVITY WILL BE MOVING SE...AND IS PROGGED BY THE
LOCAL WRF AND RUC TO AFFECT SW VA BETWEEN 02Z AND MIDNIGHT...THEN NE
TN AFTER MIDNIGHT. MUCAPE IN THE 1500-2000 J/KG RANGE AND 0-6 KM
SHEAR AROUND 35-40 KTS WILL MEAN A CHANCE OF SOME STORMS REACHING
SEVERE LEVELS. ACTIVITY SHOULD DIMINISH AFTER 06Z. BEHIND THE
EXITING VORT MAX.
ANOTHER DISTURBANCE IN THE NW FLOW ALOFT WILL MOVE THROUGH TOMORROW
AFTERNOON. THE CAP TOMORROW AFTERNOON IS WEAKER IN SOUTHERN
AREAS...AND LINGERING BOUNDARIES FROM OVERNIGHT CONVECTION MAY AID
DEVELOPMENT IN THE CENTRAL VALLEY. MLCAPE VALUES WILL BE VERY HIGH
CENTRAL AND SOUTH...UP TO 3500 J/KG ACCORDING TO THE NAM...WITH GOOD
0-6 KM SHEAR. AGAIN...WITH LIMITED MOISTURE...COVERAGE MAY NOT BE
MORE THAN SCATTERED AND POPS WILL STAY IN THE CHANCE RANGE...BUT
WHAT STORMS DO FORM COULD BE STRONG TO SEVERE WITH LARGE HAIL THE
MAIN THREAT.
.LONG TERM (THURSDAY NIGHT THROUGH WEDNESDAY)...WEAKENING FRONTAL
BOUNDARY WILL SLOWLY DROP SOUTH ACROSS THE REGION THURSDAY NIGHT AND
FRIDAY FOR CONTINUED SCATTERED TO ISOLATED CONVECTION. AIR MASS
WILL BE UNSTABLE AND A 850 JET MOVING THROUGH WILL ALLOW FOR THE
CHANCE OF AN OCCASIONAL STRONG TO SEVERE THUNDERSTORM TO BE
POSSIBLE. UPPER RIDGE BUILDS TO OUR WEST DURING THE WEEKEND PUTTING
THE MRX CWA IN A DRY NORTHWEST FLOW ALOFT FOR DRY CONDITIONS
SATURDAY. LOW LEVEL MOISTURE BEGINS TO MOVE BACK INTO SOUTHERN ARES
LATE SUNDAY AND COULD SEE A FEW ISOLATED STORMS DEVELOP LATE IN THE
DAY. THE RIDGE SHIFTS EAST INTO THE AREA ON MONDAY ALLOWING LOW
LEVEL MOISTURE TO PUSH INTO THE REST OF THE AREA. THIS COMBINED
WITH STRONG DAYTIME HEATING WILL PROVIDE INGREDIENTS FOR ISOLATED
DIURNAL CONVECTION THROUGH THE REST OF THE EXTENDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 62 88 66 87 / 10 20 20 30
KNOXVILLE MCGHEE TYSON AIRPORT, TN 63 85 62 83 / 20 50 20 20
OAK RIDGE, TN 63 85 62 82 / 20 50 20 20
TRI CITIES AIRPORT, TN 63 81 56 78 / 50 40 20 20
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS/MJB
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1023 AM EDT WED MAY 21 2014
.DISCUSSION...
12Z OHX SOUNDING AND RUC FORECAST SOUNDINGS INDICATE A STRONG
CAPPING INVERSION THAT WILL SUPPRESS CONVECTIVE DEVELOPMENT THROUGH
MOST OF THE AFTERNOON. THE CAP WILL BE WEAKEST OVER SW VA AND NE
TN...AND STRONGEST IN THE SOUTHERN VALLEY. RADAR CURRENTLY SHOWS
SHOWERS IN MIDDLE TN...BUT SURFACE OBS DO NOT SHOW PRECIP REACHING
THR GROUND...OR AT LEAST IT IS VERY LIGHT. THIS ACTIVITY IS
EXPECTED TO CONTINUE TO WEAKEN AS IT MOVES SE.
WILL MAKE SOME MINOR ADJUSTMENTS TO POP/WX GRIDS TO FOCUS MORE ON
NORTHERN AREAS THIS AFTERNOON. TEMPERATURES LOOK ON TRACK.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1221 PM CDT WED MAY 21 2014
.AVIATION...
18Z TAF CYCLE
SURFACE LOW OVER THE NORTHERN TEXAS PANHANDLE WITH FRONTAL BOUNDARY
STRETCHING SOUTHWEST TO NORTHEAST FROM THE NORTHWEST TEXAS PANHANDLE
INTO THE EASTERN OKLAHOMA PANHANDLE. DRYLINE LOCATED FROM THE
SURFACE LOW INTO EASTERN NEW MEXICO. THE DRYLINE SHOULD MOVE FURTHER
EAST INTO THE CENTRAL TEXAS PANHANDLE AS THE SURFACE LOW AND FRONTAL
BOUNDARY LIFT NORTH LATER TODAY AND THIS EVENING. EXPECTING
CONVECTION TO DEVELOP BY 21Z TO 23Z TODAY WHICH SHOULD AFFECT MAINLY
THE AMARILLO AND DALHART TAF SITES. DECIDED TO INTRODUCE A TEMPO
GROUP FOR CONVECTION BETWEEN 00Z AND 04Z THURSDAY AT BOTH TAF SITES
AS THIS APPEARS TO BE THE WINDOW FOR THE GREATEST CHANCES FOR
CONVECTION. VFR CONDITIONS WILL PREVAIL EXCEPT FOR MVFR CEILINGS IN
AND NEAR THE CONVECTION. WINDS WILL BE FROM THE SOUTHWEST 10 TO 20
KNOTS AT THE AMARILLO TAF SITE THEN BACKING AROUND TO THE SOUTHEAST
AND SOUTH 5 TO 15 KNOTS AFTER 00Z THURSDAY. WIND GUSTS TO NEAR 30 TO
40 KNOTS IN AND NEAR THUNDERSTORMS AT THE DALHART AND AMARILLO TAF
SITES. THE FRONTAL BOUNDARY WILL ALLOW FOR NORTH WINDS 10 TO 20 KNOTS
WITH HIGHER GUSTS AT THE DALHART AND GUYMON TAF SITES THEN BECOMING
SOUTH AND SOUTHEAST AT THE DALHART TAF SITE AFTER 20Z TODAY ONCE THE
FRONT LIFTS NORTH. NORTH AND NORTHEAST WINDS 10 TO 20 KNOTS AT THE
GUYMON TAF SITE UNTIL AFTER 06Z TO 09Z THURSDAY ONCE THE FRONT LIFTS
BACK NORTH AND WINDS BECOME SOUTH AND SOUTHEAST 5 TO 15 KNOTS.
SCHNEIDER
&&
.PREV DISCUSSION... /ISSUED 636 AM CDT WED MAY 21 2014/
AVIATION...
RETREATING DRYLINE HAS ALLOWED SURFACE DEWPOINTS TO INCREASE FROM 16
TO 51 DEGREES FAHRENHEIT SINCE 11 PM. SOUTHWEST LOW-LEVEL WINDS AS
SAMPLED BY KAMA VAD WINDS ARE MOIST...WITH RUC ANALYSIS DEPICTING 850
MB DEWPOINTS OF 9 TO 10 DEGREES CELSIUS JUST UPSTREAM. DEEPER AND
RICHER MOISTURE LIES ACROSS SOUTHEAST HALF OF TEXAS PANHANDLE...SOUTH
AND SOUTHEAST OF KAMA.
THICKENING MID-LEVEL CLOUDS THIS MORNING WILL STILL ALLOW SURFACE TO
WARM...WITH CONVECTIVE TEMPERATURES BEING REACHED BY 21Z. DRYLINE
SHOULD BE POISED NEAR KAMA AT THAT TIME...WITH MODEST INSTABILITY
AXIS IN CLOSE PROXIMITY. ISOLATED TO SCATTERED THUNDERSTORMS ARE
EXPECTED MAINLY AFTER 21Z NEAR KAMA AND KGUY...NEAR DRYLINE AND COLD
FRONT RESPECTIVELY. KDHT LESS LIKELY TO BE IMPACTED DUE TO DRIER
LOW- LEVEL AIR. OCCASIONAL VORTICITY MAXIMA EXPECTED TO PASS OVER
THE FORECAST AREA THIS EVENING AND TONIGHT...PROVIDING SUPPORT FOR
SHOWERS AND THUNDERSTORMS. WILL NOT INCLUDE THUNDER IN FORECASTS AT
THIS TIME...BUT WILL WAIT UNTIL HIGHER CERTAINTY OF TIMING AND
LOCATION OF DEVELOPMENT CAN BE ATTAINED.
COCKRELL
PREV DISCUSSION... /ISSUED 506 AM CDT WED MAY 21 2014/
DISCUSSION...
PRECIPITATION CHANCES...WHICH START TODAY AND CONTINUE THROUGH THE
MEMORIAL DAY WEEKEND...GRAB THE MAIN FOCUS OF THIS FORECAST.
THE UPPER LOW THAT WILL BRING INCREASING RAIN CHANCES TO THE
PANHANDLES OVER THE NEXT SEVERAL DAYS WAS CENTERED OVER SOUTHERN NV
EARLY THIS MORNING. WATER VAPOR IMAGERY SHOWED INCREASING MID/UPPER-
LEVEL SUBTROPICAL MOISTURE STREAMING NORTHEAST ACROSS THE SOUTHERN
HIGH PLAINS IN BETWEEN THE UPPER LOW AND RIDGING OVER THE LOWER MS
VALLEY. AT THE SURFACE...A COLD FRONT EXTENDED SOUTHWEST ACROSS KS TO
ALONG THE OK PANHANDLE/KS STATE LINE...WITH A DRYLINE EXTENDING
SOUTHWEST ACROSS THE TX PANHANDLE FROM JUST WEST OF PERRYTON TO
BETWEEN AMARILLO AND HEREFORD.
THESE TWO SURFACE BOUNDARIES...THE COLD FRONT AND DRYLINE...WILL BE
INSTRUMENTAL TO THUNDERSTORM CHANCES THIS AFTERNOON AND EVENING. THE
COLD FRONT IS EXPECTED TO PUSH SOUTH INTO THE NORTHERN TX PANHANDLE
THIS MORNING...BEFORE RETREATING NORTHWARD TOWARD THE CO/KS STATE
LINE THIS AFTERNOON. EXPECT THE DRYLINE /FAIRLY DIFFUSE/ TO BE
POSITIONED FROM AROUND SPEARMAN OR PERRYTON SOUTHWEST ROUGHLY ALONG A
BORGER/AMARILLO/HEREFORD LINE MID TO LATE AFTERNOON. WITH MINIMAL
CAPPING AND A WEAK MID-LEVEL SHORTWAVE TROUGH APPROACHING THE
AREA...ISOLATED TO SCATTERED CONVECTION IS EXPECTED TO INITIATE ALONG
THE BOUNDARIES THIS AFTERNOON. SOME OF THE STORMS COULD BE STRONG TO
SEVERE...WITH HAIL UP TO HALF DOLLAR SIZE AND WIND GUSTS TO 60 MPH
THE PRIMARY THREATS. LOW-LEVEL MOISTURE IS STILL SOMEWHAT
LIMITED...SO THE CONVECTION WILL BE FAIRLY HIGH-BASED. 0-1KM MLCAPES
SHOULD REACH AROUND 1500 J/KG TODAY NORTH OF THE FRONT AND EAST OF
THE DRYLINE. DEEP LAYER SHEAR WILL BE WEAKER ALONG THE DRYLINE...BUT
NOT BAD /30-40 KTS/ JUST NORTH OF THE SURFACE FRONT ACROSS THE OK
PANHANDLE...THUS THINK THE FAR NORTHERN PORTION OF THE CWA WILL BE
THE MOST FAVORABLE LOCATION FOR A FEW SEVERE STORMS. KEPT SOME LOW
POPS IN WEST OF THE DRYLINE/SOUTH OF THE FRONT WHERE SOME HIGH-BASED
SHOWERS OR MAYBE A WEAK THUNDERSTORM CAN/T BE RULED OUT DUE TO THE
INCREASING MID-LEVEL MOISTURE...SOME VERY WEAK INSTABILITY...AND THE
AFOREMENTIONED WEAK MID-LEVEL SHORTWAVE. TEMPS WILL BE COOLER TODAY
THAN THE PAST COUPLE OF DAYS...WITH FORECAST HIGHS IN THE LOWER 80S
TO LOWER 90S.
THUNDERSTORM CHANCES WILL BE ON THE INCREASE THURSDAY THROUGH
SATURDAY...AND LINGER THROUGH MONDAY. THE BIG PICTURE HASN/T CHANGED
MUCH...WITH THE UPPER LOW PROGGED TO SLOWLY WOBBLE ACROSS THE
SOUTHWEST THROUGH EARLY SATURDAY MORNING BEFORE LIFTING ACROSS THE
SOUTHERN ROCKIES AND SOUTHERN/CENTRAL HIGH PLAINS OVER THE HOLIDAY
WEEKEND...EVENTUALLY PUSHING EAST OF THE PANHANDLES LATE MONDAY
NIGHT/TUESDAY. LOW-LEVEL GULF MOISTURE WILL ADVECT NORTHWEST THROUGH
THE PANHANDLES INTO EASTERN NM ON THURSDAY...THEN REMAIN IN PLACE
THROUGH THE UPCOMING WEEKEND. THE COMBINATION OF THIS GULF MOISTURE
AND THE SUBTROPICAL MOISTURE TAP ALOFT WILL BOOST PRECIPITABLE WATER
VALUES TO JUST UNDER AN INCH IN THE NORTHWEST PANHANDLES TO NEAR AN
INCH AND A HALF IN THE EASTERN PANHANDLES. DAILY ROUNDS OF
THUNDERSTORMS ARE ANTICIPATED THROUGH MONDAY DUE TO FORCING FROM
EJECTING WEAK SHORTWAVES...BROAD DIFFLUENCE ALOFT...AND DIURNAL
HEATING OF A WEAKLY CAPPED ATMOSPHERE. THE NIGHTLY STRENGTHENING OF
THE LLJ WILL ALSO LIKELY HELP TO SUSTAIN SOME OF THE CONVECTION INTO
THE OVERNIGHT HOURS THURSDAY NIGHT THROUGH SUNDAY NIGHT.
IN TERMS OF SEVERE WEATHER...A FEW STRONG TO SEVERE STORMS WILL BE
POSSIBLE BOTH THURSDAY AND FRIDAY. INSTABILITY WILL BE DECENT WITH
MLCAPES PROGGED AROUND 1500 J/KG EACH DAY...BUT FLOW ALOFT AND
RESULTANT DEEP LAYER SHEAR WILL BE ON THE WEAK SIDE /30 KTS OR LESS/.
THIS WILL BE SUFFICIENT TO SUPPORT SOME STRONG MULTICELLULAR
CONVECTION...BUT WIDESPREAD/ORGANIZED SEVERE WEATHER IS NOT
ANTICIPATED DUE TO THE WEAKER SHEAR. CONDITIONS DO LOOK MORE
FAVORABLE FOR MORE ORGANIZED SEVERE WEATHER SATURDAY AND SUNDAY AS
THE FLOW ALOFT STRENGTHENS AHEAD OF THE APPROACHING UPPER LOW. DEEP
LAYER SHEAR SHOULD INCREASE TO AROUND 40 KTS OR HIGHER ACROSS THE
WESTERN AND CENTRAL PANHANDLES ON SATURDAY...WITH SIMILAR VALUES THAN
TRANSLATING ACROSS THE CENTRAL AND EASTERN PANHANDLES ON SUNDAY. CONTINUED
MOIST LOW-LEVELS AND COOLING TEMPS ALOFT WILL LIKELY LEAD TO MLCAPES
IN THE 1500-2000 J/KG RANGE. ACTUAL VALUES WILL BE MODULATED BY CLOUD
COVER AND POSSIBLE EARLY DAY CONVECTION...LEADING TO SOME UNCERTAINTY
HERE. HOWEVER...IT DOES APPEAR THAT SATURDAY AND SUNDAY WILL BE THE
DAYS TO WATCH FOR MORE ORGANIZED SEVERE CONVECTION. SOME SEVERE
POTENTIAL WILL LINGER ACROSS THE FAR EASTERN PANHANDLES ON
MONDAY...BEFORE THE RAIN AND THUNDERSTORMS SHIFT EAST OUT OF THE AREA
MONDAY NIGHT AS THE UPPER LOW TRACKS EAST INTO KS/OK. HEAVY
RAINFALL...LEADING TO SOME LOCALIZED FLOODING...WILL ALSO BE POSSIBLE
THURSDAY THROUGH MONDAY GIVEN THE AMPLE MOISTURE IN PLACE AND
POSSIBLE TRAINING FROM REPEATED ROUNDS OF CONVECTION.
DRY CONDITIONS WILL RETURN NEXT TUESDAY AND WEDNESDAY AS SUBSIDENCE
TAKES HOLD BEHIND THE DEPARTING UPPER LOW. AFTER A STRETCH OF COOLER
WEATHER THROUGH THE HOLIDAY WEEKEND...TEMPS WILL BEGIN TO REBOUND
TUESDAY AS HEIGHTS RISE AS SHORTWAVE RIDGING BUILDS IN BEHIND THE
UPPER LOW.
KB
FIRE WEATHER...
ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS THE FAR
WESTERN PANHANDLES THIS AFTERNOON INTO EARLY THIS EVENING. SOUTH TO
SOUTHWEST WINDS ARE EXPECTED TO INCREASE TO 15 TO 20 MPH WHILE
RELATIVE HUMIDITIES FALL TO 10 TO 20 PERCENT. ISOLATED THUNDERSTORMS
IN THIS AREA COULD ALSO PRODUCE A FEW CLOUD-TO-GROUND LIGHTNING
STRIKES AND LITTLE RAINFALL. NO ELEVATED OR CRITICAL FIRE WEATHER
CONDITIONS ARE ANTICIPATED THURSDAY THROUGH EARLY NEXT WEEK DUE TO
INCREASING MOISTURE AND RAINFALL CHANCES.
KB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
11/13
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
636 AM CDT WED MAY 21 2014
.AVIATION...
RETREATING DRYLINE HAS ALLOWED SURFACE DEWPOINTS TO INCREASE FROM 16
TO 51 DEGREES FAHRENHEIT SINCE 11 PM. SOUTHWEST LOW-LEVEL WINDS AS
SAMPLED BY KAMA VAD WINDS ARE MOIST...WITH RUC ANALYSIS DEPICTING 850
MB DEWPOINTS OF 9 TO 10 DEGREES CELSIUS JUST UPSTREAM. DEEPER AND
RICHER MOISTURE LIES ACROSS SOUTHEAST HALF OF TEXAS PANHANDLE...SOUTH
AND SOUTHEAST OF KAMA.
THICKENING MID-LEVEL CLOUDS THIS MORNING WILL STILL ALLOW SURFACE TO
WARM...WITH CONVECTIVE TEMPERATURES BEING REACHED BY 21Z. DRYLINE
SHOULD BE POISED NEAR KAMA AT THAT TIME...WITH MODEST INSTABILITY
AXIS IN CLOSE PROXIMITY. ISOLATED TO SCATTERED THUNDERSTORMS ARE
EXPECTED MAINLY AFTER 21Z NEAR KAMA AND KGUY...NEAR DRYLINE AND COLD
FRONT RESPECTIVELY. KDHT LESS LIKELY TO BE IMPACTED DUE TO DRIER
LOW- LEVEL AIR. OCCASIONAL VORTICITY MAXIMA EXPECTED TO PASS OVER
THE FORECAST AREA THIS EVENING AND TONIGHT...PROVIDING SUPPORT FOR
SHOWERS AND THUNDERSTORMS. WILL NOT INCLUDE THUNDER IN FORECASTS AT
THIS TIME...BUT WILL WAIT UNTIL HIGHER CERTAINTY OF TIMING AND
LOCATION OF DEVELOPMENT CAN BE ATTAINED.
COCKRELL
&&
.PREV DISCUSSION... /ISSUED 506 AM CDT WED MAY 21 2014/
DISCUSSION...
PRECIPITATION CHANCES...WHICH START TODAY AND CONTINUE THROUGH THE
MEMORIAL DAY WEEKEND...GRAB THE MAIN FOCUS OF THIS FORECAST.
THE UPPER LOW THAT WILL BRING INCREASING RAIN CHANCES TO THE
PANHANDLES OVER THE NEXT SEVERAL DAYS WAS CENTERED OVER SOUTHERN NV
EARLY THIS MORNING. WATER VAPOR IMAGERY SHOWED INCREASING MID/UPPER-
LEVEL SUBTROPICAL MOISTURE STREAMING NORTHEAST ACROSS THE SOUTHERN
HIGH PLAINS IN BETWEEN THE UPPER LOW AND RIDGING OVER THE LOWER MS
VALLEY. AT THE SURFACE...A COLD FRONT EXTENDED SOUTHWEST ACROSS KS TO
ALONG THE OK PANHANDLE/KS STATE LINE...WITH A DRYLINE EXTENDING
SOUTHWEST ACROSS THE TX PANHANDLE FROM JUST WEST OF PERRYTON TO
BETWEEN AMARILLO AND HEREFORD.
THESE TWO SURFACE BOUNDARIES...THE COLD FRONT AND DRYLINE...WILL BE
INSTRUMENTAL TO THUNDERSTORM CHANCES THIS AFTERNOON AND EVENING. THE
COLD FRONT IS EXPECTED TO PUSH SOUTH INTO THE NORTHERN TX PANHANDLE
THIS MORNING...BEFORE RETREATING NORTHWARD TOWARD THE CO/KS STATE
LINE THIS AFTERNOON. EXPECT THE DRYLINE /FAIRLY DIFFUSE/ TO BE
POSITIONED FROM AROUND SPEARMAN OR PERRYTON SOUTHWEST ROUGHLY ALONG A
BORGER/AMARILLO/HEREFORD LINE MID TO LATE AFTERNOON. WITH MINIMAL
CAPPING AND A WEAK MID-LEVEL SHORTWAVE TROUGH APPROACHING THE
AREA...ISOLATED TO SCATTERED CONVECTION IS EXPECTED TO INITIATE ALONG
THE BOUNDARIES THIS AFTERNOON. SOME OF THE STORMS COULD BE STRONG TO
SEVERE...WITH HAIL UP TO HALF DOLLAR SIZE AND WIND GUSTS TO 60 MPH
THE PRIMARY THREATS. LOW-LEVEL MOISTURE IS STILL SOMEWHAT
LIMITED...SO THE CONVECTION WILL BE FAIRLY HIGH-BASED. 0-1KM MLCAPES
SHOULD REACH AROUND 1500 J/KG TODAY NORTH OF THE FRONT AND EAST OF
THE DRYLINE. DEEP LAYER SHEAR WILL BE WEAKER ALONG THE DRYLINE...BUT
NOT BAD /30-40 KTS/ JUST NORTH OF THE SURFACE FRONT ACROSS THE OK
PANHANDLE...THUS THINK THE FAR NORTHERN PORTION OF THE CWA WILL BE
THE MOST FAVORABLE LOCATION FOR A FEW SEVERE STORMS. KEPT SOME LOW
POPS IN WEST OF THE DRYLINE/SOUTH OF THE FRONT WHERE SOME HIGH-BASED
SHOWERS OR MAYBE A WEAK THUNDERSTORM CAN/T BE RULED OUT DUE TO THE
INCREASING MID-LEVEL MOISTURE...SOME VERY WEAK INSTABILITY...AND THE
AFOREMENTIONED WEAK MID-LEVEL SHORTWAVE. TEMPS WILL BE COOLER TODAY
THAN THE PAST COUPLE OF DAYS...WITH FORECAST HIGHS IN THE LOWER 80S
TO LOWER 90S.
THUNDERSTORM CHANCES WILL BE ON THE INCREASE THURSDAY THROUGH
SATURDAY...AND LINGER THROUGH MONDAY. THE BIG PICTURE HASN/T CHANGED
MUCH...WITH THE UPPER LOW PROGGED TO SLOWLY WOBBLE ACROSS THE
SOUTHWEST THROUGH EARLY SATURDAY MORNING BEFORE LIFTING ACROSS THE
SOUTHERN ROCKIES AND SOUTHERN/CENTRAL HIGH PLAINS OVER THE HOLIDAY
WEEKEND...EVENTUALLY PUSHING EAST OF THE PANHANDLES LATE MONDAY
NIGHT/TUESDAY. LOW-LEVEL GULF MOISTURE WILL ADVECT NORTHWEST THROUGH
THE PANHANDLES INTO EASTERN NM ON THURSDAY...THEN REMAIN IN PLACE
THROUGH THE UPCOMING WEEKEND. THE COMBINATION OF THIS GULF MOISTURE
AND THE SUBTROPICAL MOISTURE TAP ALOFT WILL BOOST PRECIPITABLE WATER
VALUES TO JUST UNDER AN INCH IN THE NORTHWEST PANHANDLES TO NEAR AN
INCH AND A HALF IN THE EASTERN PANHANDLES. DAILY ROUNDS OF
THUNDERSTORMS ARE ANTICIPATED THROUGH MONDAY DUE TO FORCING FROM
EJECTING WEAK SHORTWAVES...BROAD DIFFLUENCE ALOFT...AND DIURNAL
HEATING OF A WEAKLY CAPPED ATMOSPHERE. THE NIGHTLY STRENGTHENING OF
THE LLJ WILL ALSO LIKELY HELP TO SUSTAIN SOME OF THE CONVECTION INTO
THE OVERNIGHT HOURS THURSDAY NIGHT THROUGH SUNDAY NIGHT.
IN TERMS OF SEVERE WEATHER...A FEW STRONG TO SEVERE STORMS WILL BE
POSSIBLE BOTH THURSDAY AND FRIDAY. INSTABILITY WILL BE DECENT WITH
MLCAPES PROGGED AROUND 1500 J/KG EACH DAY...BUT FLOW ALOFT AND
RESULTANT DEEP LAYER SHEAR WILL BE ON THE WEAK SIDE /30 KTS OR LESS/.
THIS WILL BE SUFFICIENT TO SUPPORT SOME STRONG MULTICELLULAR
CONVECTION...BUT WIDESPREAD/ORGANIZED SEVERE WEATHER IS NOT
ANTICIPATED DUE TO THE WEAKER SHEAR. CONDITIONS DO LOOK MORE
FAVORABLE FOR MORE ORGANIZED SEVERE WEATHER SATURDAY AND SUNDAY AS
THE FLOW ALOFT STRENGTHENS AHEAD OF THE APPROACHING UPPER LOW. DEEP
LAYER SHEAR SHOULD INCREASE TO AROUND 40 KTS OR HIGHER ACROSS THE
WESTERN AND CENTRAL PANHANDLES ON SATURDAY...WITH SIMILAR VALUES THAN
TRANSLATING ACROSS THE CENTRAL AND EASTERN PANHANDLES ON SUNDAY. CONTINUED
MOIST LOW-LEVELS AND COOLING TEMPS ALOFT WILL LIKELY LEAD TO MLCAPES
IN THE 1500-2000 J/KG RANGE. ACTUAL VALUES WILL BE MODULATED BY CLOUD
COVER AND POSSIBLE EARLY DAY CONVECTION...LEADING TO SOME UNCERTAINTY
HERE. HOWEVER...IT DOES APPEAR THAT SATURDAY AND SUNDAY WILL BE THE
DAYS TO WATCH FOR MORE ORGANIZED SEVERE CONVECTION. SOME SEVERE
POTENTIAL WILL LINGER ACROSS THE FAR EASTERN PANHANDLES ON
MONDAY...BEFORE THE RAIN AND THUNDERSTORMS SHIFT EAST OUT OF THE AREA
MONDAY NIGHT AS THE UPPER LOW TRACKS EAST INTO KS/OK. HEAVY
RAINFALL...LEADING TO SOME LOCALIZED FLOODING...WILL ALSO BE POSSIBLE
THURSDAY THROUGH MONDAY GIVEN THE AMPLE MOISTURE IN PLACE AND
POSSIBLE TRAINING FROM REPEATED ROUNDS OF CONVECTION.
DRY CONDITIONS WILL RETURN NEXT TUESDAY AND WEDNESDAY AS SUBSIDENCE
TAKES HOLD BEHIND THE DEPARTING UPPER LOW. AFTER A STRETCH OF COOLER
WEATHER THROUGH THE HOLIDAY WEEKEND...TEMPS WILL BEGIN TO REBOUND
TUESDAY AS HEIGHTS RISE AS SHORTWAVE RIDGING BUILDS IN BEHIND THE
UPPER LOW.
KB
FIRE WEATHER...
ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS THE FAR
WESTERN PANHANDLES THIS AFTERNOON INTO EARLY THIS EVENING. SOUTH TO
SOUTHWEST WINDS ARE EXPECTED TO INCREASE TO 15 TO 20 MPH WHILE
RELATIVE HUMIDITIES FALL TO 10 TO 20 PERCENT. ISOLATED THUNDERSTORMS
IN THIS AREA COULD ALSO PRODUCE A FEW CLOUD-TO-GROUND LIGHTNING
STRIKES AND LITTLE RAINFALL. NO ELEVATED OR CRITICAL FIRE WEATHER
CONDITIONS ARE ANTICIPATED THURSDAY THROUGH EARLY NEXT WEEK DUE TO
INCREASING MOISTURE AND RAINFALL CHANCES.
KB
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 87 61 83 59 79 / 30 30 30 40 50
BEAVER OK 93 63 88 63 84 / 30 30 40 40 50
BOISE CITY OK 84 55 83 56 78 / 20 20 40 40 50
BORGER TX 92 66 87 62 81 / 20 30 30 40 50
BOYS RANCH TX 90 60 84 62 79 / 20 20 40 40 50
CANYON TX 87 60 83 58 79 / 30 30 30 40 50
CLARENDON TX 92 64 85 62 79 / 20 20 20 40 50
DALHART TX 85 56 84 57 77 / 20 20 40 40 50
GUYMON OK 90 59 86 60 80 / 30 20 40 40 50
HEREFORD TX 84 59 82 59 79 / 20 20 30 40 50
LIPSCOMB TX 93 63 89 62 81 / 20 20 20 40 50
PAMPA TX 90 64 84 60 77 / 30 30 20 40 50
SHAMROCK TX 91 64 86 64 81 / 10 10 20 30 40
WELLINGTON TX 93 66 88 66 83 / 5 10 20 30 40
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
03/08
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1211 AM CDT WED MAY 21 2014
.DISCUSSION...
SEE AVIATION FOR 6Z TAF ISSUANCE.
&&
.AVIATION...
MVFR CONDITIONS HAVE FORMED ALONG THE COAST THIS EVENING AND HAVE
STARTED TO TRY AND MOVE INLAND. MORE WIDESPREAD MVFR CONDITIONS
REMAIN OFF TO OUR WEST. HRRR SHOWING LOW CLOUDS FILLING IN FROM
THE WEST BUT REMAINING PATCHY. GFS FORECAST SOUNDINGS ALSO HINT AT
THIS. AMDAR SOUNDINGS AGAIN LOOK SIMILAR TO LAST NIGHT BUT RH
LOOKS A TAD LOWER TONIGHT IN THE LOW LEVELS. THIS MEANS THAT TAF
SITES WILL LIKELY BOUNCE IN AND OUT OF MVFR TONIGHT WITH TAF SITES
FURTHER TO THE WEST HAVING A GREATER CHANCE OF STAYING MVFR
OVERNIGHT. 23
&&
.PREV DISCUSSION... /ISSUED 931 PM CDT TUE MAY 20 2014/
UPDATE...
00Z UA ANALYSIS INDICATES STRONG 850 RIDGING OVER THE FL PANHANDLE
EXTENDING INTO TEXAS WITH SOUTHERLY FLOW TOPPED BY 500MB RIDGE
OVER CENTRAL AND NORTHEAST TEXAS. SUBSIDENCE IS THE WEATHER WORD
OF THE DAY. SO OVERNIGHT EXPECT THAT LL MOISTURE WILL CONDENSE OUT
AND LIKELY TO FORM A BKN/OVER SC DECK OVER MAINLY THE WESTERN AND
NORTHWESTERN AREAS BUT THE METROPLEX SHOULD SEE SOME MOSTLY CLOUDY
TO CLOUDY SKIES AFTER MIDNIGHT AS WELL. UPDATED THE FORECAST TO
DECREASE THE CLOUD COVER THE CLEAR AT 9 FOR ALL THE INLAND
COUNTIES. THEN INCREASE THE CLOUD COVER OVERNIGHT WITH MOSTLY
CLOUDY CONDITIONS DEVELOPING. IN TURN DID RAISE TEMPS A FEW
DEGREES MAINLY WEST OF I-45.
45
PREV DISCUSSION... /ISSUED 246 PM CDT TUE MAY 20 2014/
DISCUSSION...
LATE SPRING DOLDRUMS CONTINUE AS VERY LITTLE DAY TO DAY CHANGES
ARE EXPECTED. UPPER LEVEL RIDGING WILL REMAIN OVER TEXAS THROUGH
FRIDAY WITH A GRADUAL WARMING TREND. RAIN CHANCES WILL REMAIN VERY
LOW WITH ONLY ISOLATED STREAMER SHOWERS POSSIBLE DURING THE EARLY
MORNING HOURS. THE UPPER RIDGE MOVES EAST OVER THE WEEKEND AND
HEIGHTS WILL BEGIN TO FALL. MODELS ARE TRENDING COOLER OVER THE
WEEKEND WHICH SEEMS REASONABLE CONSIDERING THE LOWER HEIGHTS. AN
UPPER LEVEL TROUGH WILL APPROACH THE STATE EARLY NEXT WEEK. IT
STILL LOOKS LIKE THE UPPER TROUGH WILL PASS TOO FAR NORTH TO HAVE
MUCH OF AN IMPACT LOCALLY. STILL...LOWER HEIGHTS AND INCREASING
LIFT AHEAD OF THE TROUGH COULD TRIGGER A FEW SHRA/TSRA SO WILL
MAINTAIN SLIGHT RAIN CHANCES MON/TUES. 43
MARINE...
PERSISTENT ONSHORE FLOW THROUGH THE REMAINDER OF THE WEEK WILL BE
GENERALLY LIGHT...OCCASIONALLY NEAR CAUTION MAGNITUDES DURING THE
OVERNIGHT INTO EARLY MORNING HOURS. SLIGHTLY CHOPPY BAY CONDITIONS
AND AVERAGE 2 FOOT NEARSHORE WAVE HEIGHTS...3 TO 4 FOOT HEIGHTS
FURTHER OFFSHORE. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 87 70 90 69 87 / 10 0 0 10 10
HOUSTON (IAH) 86 70 88 69 86 / 10 0 0 10 10
GALVESTON (GLS) 82 73 81 73 83 / 10 0 0 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...45
AVIATION/MARINE...23
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
614 AM CDT WED MAY 21 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CDT WED MAY 21 2014
MAIN FORECAST CONCERNS THIS PERIOD...TEMPERATURES AND CLOUD TRENDS.
DATA ANALYSIS AT 06Z HAD THE WEAK SFC TROUGH/FRONT FROM SOUTHWEST IA
TO NEAR KDVN AND CHICAGO. SCT SHRA/TSRA CONTINUED NEAR THIS
BOUNDARY...MOVING EAST/SOUTHEAST AWAY FROM THE FCST AREA. A
SECONDARY SFC TROUGH/FRONT EXTEND FROM A LOW IN SOUTHWEST ONT SOUTH
WARD THRU KDLH AND WESTERN WI. WEST AND NORTH OF THESE BOUNDARIES
DRIER/COOLER CAN HIGH PRESSURE WAS BUILDING INTO THE NORTHERN PLAINS
AND MN. SFC DEW POINTS NEAR/AHEAD OF THE BOUNDARIES IN THE 50S TO
LOWER 60S AND IN THE 40S BEHIND THEM. FOG-PRODUCT IMAGERY SHOWING
PLENTY OF LOWER CLOUDS/MOISTURE OVER EASTERN ND/NORTHWEST MN...
HEADED SOUTHEAST IN THE FLOW BETWEEN THE ONT LOW AND DAKOTAS HIGH.
21.00Z MODELS LOOK TO HAVE INITIALIZED WELL...EXCEPT FOR GFS WITH
ITS 5F TOO HIGH BIAS ON SFC DEW POINTS ACROSS THE MID/UPPER MS
VALLEY. PER 500MB ANALYSIS...MODELS CONVERGING ON A TIGHT CONSENSUS
TODAY/TONIGHT AS THE TROUGHING/ENERGY OVER SOUTHWEST ONT/NORTHERN MN
MOVES EAST AND RIDGING/RISING HGTS BUILD INTO THE NORTHERN PLAINS.
END RESULT IS NORTHWEST FLOW ALOFT OVER THE UPPER MIDWEST THIS
PERIOD. SHORT-TERM FCST CONFIDENCE IS GOOD THIS CYCLE.
IN THE SHORT TERM...WITH NORTHWEST FLOW ALOFT TODAY/TONIGHT THE
CANADIAN HIGH OVER THE DAKOTAS WILL SLOWLY BUILD SOUTHEAST AND END
UP CENTERED OVER MN BY 12Z THU. A DRY...QUIET/COOLER PERIOD FOR
TODAY/TONIGHT UNDER THE INFLUENCE OF THIS HIGH. LOW LEVEL COLD
ADVECTION AHEAD OF THE HIGH SENDS 850MB TEMPS DOWN INTO THE +4C TO
+10C RANGE BY 12Z THU...SO COOLER THIS TIME MEANS HIGHS/LOWS CLOSE
TO NORMAL FOR TODAY/TONIGHT. BIGGEST CONCERN THIS PERIOD IS WHAT
HAPPENS WITH THE STRATO-CU CLOUDS/MOISTURE OVER EASTERN ND/NORTHWEST
MN. MODEL 925-850MB RH PROGS DOING A DECENT JOB WITH THIS MOISTURE/
CLOUDS EARLY THIS MORNING...HOWEVER FOG PRODUCT IMAGERY/SFC OBS SHOW
THE CLOUDS MOVING MORE EAST VS. SOUTHEAST. CURRENT TRAJECTORY WOULD
TAKE THESE CLOUDS/MOISTURE MAINLY ACROSS CLARK/TAYLOR COUNTIES THIS
AFTERNOON/EVENING WHILE MODEL RH PROGS SWEEP THE CLOUDS/MOISTURE AS
FAR SOUTH AS THE MN/IA BORDER. 21.00Z KBIS RAOB SHOWED THIS MOISTURE
TO BE QUITE SHALLOW. WITH DRIER 925-700MB AIR OVER THE AREA THIS
MORNING AND DIURNAL WARMING/MIXING EXPECTED TO 850MB...WILL REMAIN
OPTIMISTIC FOR MORE SUN THAN CLOUDS ACROSS ALL BUT THE FAR NORTH END
OF THE FCST AREA THIS AFTERNOON/EARLY THIS EVENING. MODELS DO SWEEP
THIS MOISTURE EAST OF THE FCST AREA BY LATE EVENING...WITH A DEEP...
DRY AIRMASS OVER THE AREA BY THU MORNING. USED A BLEND OF THE
GUIDANCE HIGHS/LOWS FOR TODAY/TONIGHT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 317 AM CDT WED MAY 21 2014
MAIN FORECAST CONCERNS FOR THU THRU FRI NIGHT...TEMPERATURES AND
CLOUD TRENDS.
21.00Z MODELS OFFER A TIGHTER CONSENSUS IN THE THU THRU FRI NIGHT
PERIOD WITH QUITE BETWEEN MODEL AND RUN-TO-RUN CONSISTENCY TO
THEIR 19.00Z AND 20.00Z RUNS THRU FRI. BY FRI NIGHT LATEST
CONSENSUS FAVORS MORE PROGRESSIVE OF THE EARLIER RUNS WITH
SHORTWAVE ENERGY/ TROUGHING MOVING THRU THE SOUTHERN TO NORTHERN
ROCKIES. GIVEN THE TIGHT CONSENSUS THRU 12Z SAT AND RIDGING OVER
THE UPPER MIDWEST FOR RATHER TRANQUIL WEATHER...CONFIDENCE IS GOOD
FOR THU THRU FRI NIGHT.
THE TIGHT MODEL CONSENSUS HAS MID LEVEL HGTS OVER THE REGION RISING
THRU THE PERIOD WITH THE 500MB RIDGE AXIS OVER MN/IA AT 12Z SAT.
UNDER THESE RISING HGTS/RIDGE AXIS...THE CAN SFC HIGH OVER WESTERN
MN AT 12Z THU DRIFTS TO LK MICHIGAN BY 12Z SAT. MODEL SOUNDINGS HAVE
THE DEEP DRY LOOK THRU THE PERIOD...WITH PERHAPS SOME DIURNAL
CUMULUS DURING THE AFTERNOON HOURS AND SOME SCT CIRRUS FROM TIME TO
TIME. 850MB TEMP ANOMALIES AROUND -0.5 STANDARD DEVIATION FROM
12Z THU TO 12Z FRI...WARMING TO AROUND +0.5 STANDARD DEVIATION BY
12Z SAT. WITH PLENTY OF SUNSHINE THU/FRI...A DRIER LOW LEVEL
AIRMASS AND EVAPO-TRANSPIRATION 2 TO 3 WEEKS BEHIND...HIGHS
THU/FRI STILL LOOK TO BE NEAR/A BIT ABOVE NORMAL. THE DEEP DRY
AIRMASS AND HIGH NEARBY/ OVERHEAD WILL ALLOW FOR STRONGER
RADIATIONAL COOLING AND LARGER DIURNAL SWINGS AT NIGHT. LOWS
THU/FRI NIGHTS NEAR TO A BIT BELOW NORMAL LOOK GOOD. FAVORED THE
MODEL/ENSEMBLE CONSENSUS OF THE HIGHS/LOWS FOR THU THRU FRI NIGHT.
FOR SATURDAY THROUGH TUESDAY.../DAYS 4 TO 7/...
FORECAST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES STARTING SAT NIGHT
AND CONTINUING THRU TUE...TEMPERATURES.
MEDIUM RANGE MODEL RUNS OF 21.00Z IN GOOD AND IMPROVING AGREEMENT
SAT/SUN AS THE TROUGHING/ENERGY SLOWLY PROGRESS THRU THE ROCKIES AND
INTO THE CENTRAL CONUS. MID LEVEL RIDGE AXIS REMAINS OVER WI/IL THRU
SUN WHILE MN/IA COMING UNDER INCREASINGLY SOUTHWEST ON SUN. LESSER
BETWEEN MODEL AND RUN-TO-RUN CONSISTENCY MON/TUE AS THE SOUTHERN
STREAM TROUGHING SLOWLY LIFTS TOWARD/INTO THE MID/UPPER MS VALLEY.
IMPROVING CONSISTENCY AMONG THE MODELS ON THE NEXT STRONG TROUGHING
TO MOVE INTO THE WESTERN CONUS MON/TUE. EVEN WITH THE IMPROVING
LARGER SCALE CONSENSUS...SMALLER SCALE DETAIL DIFFERENCES PRODUCE
SENSIBLE WEATHER IMPACTS ALREADY SAT NIGHT. FCST CONFIDENCE IS
GOOD SAT THEN AVERAGE FOR SAT NIGHT THRU TUE.
RIDGING ALOFT/CANADIAN SFC HIGH PRESSURE REMAIN THE DOMINANT WEATHER
FEATURES THRU SAT...FOR ANOTHER DRY DAY. 925-850MB TEMPS CONTINUE TO
MODERATE AS THE CORE OF THE HIGH DRIFTS FURTHER EAST OF THE AREA AND
THE LOWER LEVEL FLOW BECOMES MORE SOUTHERLY. 850MB TEMPS IN THE +10C
TO +14C RANGE BY 00Z SUN...FOR ABOVE NORMAL HIGHS ON SAT TO START
THE HOLIDAY WEEKEND. SLOWLY PROGRESSIVE PATTERN AND THE TROUGHING
EJECTING INTO THE PLAINS WOULD THE HOLIDAY WEEKEND WEATHER GOES
DOWNHILL STARTING SAT NIGHT. MODELS START TO SPREAD INCREASING LOWER
LEVEL WARM ADVECTION/LIFT AND MOISTURE TRANSPORT INTO THE AREA SAT
NIGHT SUN...WITH CHANCES OF SHRA/TSRA WEST OF THE MS RIVER LATER SAT
NIGHT AND ACROSS THE AREA SUN. GFS THE MORE ROBUST WITH THIS...BUT
IT ALSO HAS 70F DEW POINTS ACROSS THE FCST AREA AT 00Z MON. THIS
LOOKS SUSPECT WITH THE GFS HIGH DEW POINT BIAS. ALSO LOOKING SUSPECT
IS CONVECTION SO FAR INTO/UNDER THE MID LEVEL RIDGE AXIS/
ANTICYCLONIC FLOW OVER THE MID/UPPER MS VALLEY. SOME OF THIS TIED
TO A WEAK SHORTWAVE THE MODELS PUSH THRU THE MID LEVEL RIDGE AXIS.
LEFT THE MODEL/ENSEMBLE CONSENSUS SHRA/TSRA CHANCES FOR SAT
NIGHT/SUN AS IS. HOWEVER...APPEARS GREATER SHRA/TSRA CHANCES THRU
SUN WOULD BE WEST/NORTH OF THE FCST AREA...CLOSER TO THE LOW LEVEL
TROUGH AND THERMAL/MOISTURE AXES. MAY YET BE ABLE TO SNEAK A
SECOND DRY DAY OUT OF THE HOLIDAY WEEKEND. SLOW EASTWARD
PROGRESSION OF THE LONGWAVE PATTERN MOVES THE LOWER LEVEL
TROUGHING/THETA-E RIDGING INTO/ACROSS THE FCST AREA SUN NIGHT THRU
TUE. SHRA/TSRA CHANCES THESE PERIODS LOOK BETTER TRENDED THAN
THOSE OF SAT NIGHT/SUN.
THRU ALL THIS 850MB TEMPS CONTINUE TO WARM...REACHING 1 TO 1.5
STANDARD DEVIATIONS ABOVE NORMAL BY LATER MON AND TUE. CONSENSUS
HIGHS OF 5 TO 10F ABOVE NORMAL FOR SUN THRU TUE DO LOOK WELL TRENDED
FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 614 AM CDT WED MAY 21 2014
THE WEAK COLD FRONT HAS ALREADY MOVED THROUGH BOTH TAF SITES WITH
THE WINDS COMING AROUND TO THE NORTHWEST. SATELLITE IMAGERY THIS
MORNING IS SHOWING AN AREA OF CLOUDS OVER NORTHWEST MINNESOTA
MOVING SOUTHEAST WITH MVFR TO VFR CEILINGS. BOTH THE 21.06Z NAM
AND 21.09Z RAP INDICATE THE MOISTURE WITH THESE CLOUDS SHOULD STAY
NORTH OF THE TAF SITES UNTIL POSSIBLY COMING IN LATE IN THE
AFTERNOON. FOR NOW...HAVE STAYED WITH JUST SHOWING A SCATTERED
DECK BUT IF THE MOISTURE FIELD HOLDS TOGETHER...MAY NEED TO ADD A
CEILING. THE 21.00Z KBIS SOUNDING INDICATED THE MOISTURE FIELD WAS
PRETTY THIN...SO IT WILL BE INTERESTING TO SEE HOW MUCH OF THIS
SURVIVES THROUGH THE MIXING OF THE DAY.
&&
.HYDROLOGY...
ISSUED AT 317 AM CDT WED MAY 21 2014
WATER LEVELS CONTINUE TO SLOWLY FALL ALONG THE MISSISSIPPI RIVER AND
FEW LOCATIONS REMAIN ABOVE FLOOD STAGE. THE WATER LEVELS WILL REMAIN
HIGH ALONG THE MISSISSIPPI RIVER THROUGH NEXT WEEK.
FOR THE BLACK RIVER...AS FAST AS IT ROSE ABOVE FLOOD STAGE AT BLACK
RIVER FALLS TUE MORNING...IT FELL JUST AS QUICKLY BELOW FLOOD STAGE
TUE EVENING. THE BLACK RIVER IS NO LONGER EXPECTED TO REACH FLOOD
STAGE AT THE GAUGING SITE NEAR GALESVILLE WI.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...04
HYDROLOGY....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1149 PM CDT TUE MAY 20 2014
.UPDATE...
ISSUED AT 635 PM CDT TUE MAY 20 2014
SURFACE BASED CONVECTION FIRED ABOUT 2 HOURS AGO JUST SOUTH OF THE
FORECAST AREA...THROUGH THE DUBUQUE AREA...ALONG A SURFACE TROUGH
THERE. ANTICIPATING OUTFLOWS FROM THE CONVECTION WILL HELP TO KEEP
MUCH OF THE CONVECTION SOUTH OF THE FORECAST AREA THROUGH THE
EVENING...THUS HAVE CONTINUED TO TREND PRECIPITATION CHANCES DOWN
AND FARTHER SOUTH. APPEARS ONLY FAR SOUTHERN PORTIONS OF
GRANT...CLAYTON AND FAYETTE COUNTIES COULD BE CLIPPED BY
SHOWERS/STORMS COMING OUT OF CENTRAL IOWA.
MEANWHILE...A FRONTOGENETIC BAND OF HIGH BASED SHOWERS...EVEN A
FEW THUNDERSTORMS...HAS BEEN OCCURRING ACROSS NORTHWEST IOWA. WILL
HAVE TO MONITOR THIS FEATURE THROUGH THE EVENING TO SEE IF IT CAN
IMPACT SOUTHEAST MN. WOULD ANTICIPATE VERY LITTLE PRECIPITATION
DUE TO DRIER LOW LEVEL AIR THAT HAS BEEN INVADING THE AREA THIS
AFTERNOON. IN FACT...EVEN UNDER THE FRONTOGENETIC BAND...REPORTS
OF RAIN ARE HARD TO COME BY. 20.21Z RAP/HRRR GUIDANCE SUGGESTS THE
BAND WILL DIMINISH AS IT COMES INTO SOUTHEAST MN THIS EVENING...SO
GIVEN ALL OF THIS HAVE KEPT THE FORECAST DRY.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 258 PM CDT TUE MAY 20 2014
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING UPPER LEVEL RIDGE
FLATTENING OUT OVER THE UPPER MIDWEST AND GREAT LAKES REGION. A VERY
WEAK SHORTWAVE TROUGH ON THE NORTHERN PERIPHERY OF THE UPPER LEVEL
RIDGE IS PRODUCING VERY LIGHT RAIN OR SPRINKLES ACROSS SOUTHERN
MINNESOTA PER LATEST MOSAIC RADAR. LATEST 19Z SURFACE ANALYSIS
INDICATING A WEAK COLD FRONT EXTENDING FROM CENTRAL WISCONSIN INTO
CENTRAL IOWA.
MAIN FORECAST CONCERNS ARE SHOWERS AND THUNDERSTORMS DEVELOPMENT
ALONG SURFACE FRONT LATE THIS AFTERNOON AND THIS EVENING. THE LATEST
20.12Z GFS/NAM AND 20.15Z RAP ARE INDICATING ALONG SURFACE FRONT CAP
WILL BREAK IN THE 22Z TUESDAY - 02Z WEDNESDAY TIME FRAME AND FOR
SHOWERS AND THUNDERSTORMS TO DEVELOP ALONG SURFACE FRONT PER BUFKIT
SOUNDINGS OVER EXTREME SOUTHERN FORECAST AREA. THE LATEST 20.16Z
HRRR DEVELOPS SHOWERS AND THUNDERSTORMS AROUND 23Z ACROSS SOUTHERN
FAYETTE...CLAYTON AND GRANT COUNTIES. THE 20.15Z RAP AND 20.12Z NAM
INDICATES ROUGHLY 1000-2000 J/KG OF SURFACE BASE CAPE AND 0-6KM
SHEAR APPROACHING 40 KNOTS LATE THIS AFTERNOON ALONG AND AHEAD
SURFACE FRONT ACROSS THE EXTREME SOUTHERN FORECAST AREA. THE 20.15Z
RAP/20.12Z NAM SHOW 0-1KM SHEAR LESS THAN 5 KNOTS OVER THIS AREA.
THE EXTREME SOUTHERN FORECAST AREA POSSIBLY COULD SEE SEVERE
THUNDERSTORMS WITH THE MAIN THREATS AT THIS TIME LOOK TO BE LARGE
HAIL AND WIND OVER THE EXTREME SOUTHERN FORECAST AREA.
SURFACE FRONT MOVES SOUTH OF FORECAST AREA WEDNESDAY AND DRIER AIR
AND SLIGHTLY COOLER AIR FILTERS INTO THE FORECAST AREA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 258 PM CDT TUE MAY 20 2014
SURFACE RIDGE BUILDS INTO THE FORECAST AREA THURSDAY INTO FRIDAY.
WITH SUBSIDENCE UNDERNEATH RIDGE AND FORECAST AREA UNDER NORTHERLY
FLOW. THIS SHOULD ALLOW FOR DRY WEATHER CONDITIONS AND SEASONABLE
TEMPERATURES ACROSS THE FORECAST AREA.
FOCUS THEN TURNS TO FRIDAY NIGHT INTO TUESDAY...WHERE THE MAIN
CONCERNS ARE PRECIPITATION CHANCES SATURDAY NIGHT INTO TUESDAY. THE
20.12Z GFS/ECMWF/GEM ARE IN GOOD AGREEMENT IN BUILDING UPPER
LEVEL RIDGE INTO THE CENTRAL UNITED STATES THIS WEEKEND...THEN
BREAKING DOWN UPPER LEVEL RIDGE AND DEVELOP SOUTHWEST FLOW OVER
THE CENTRAL UNITED STATES BY 00Z MONDAY. THE BIGGEST DIFFERENCES
BETWEEN THE MODELS IS TIMING AND STRENGTH OF SHORTWAVE TROUGHS
EJECTING OUT INTO THE NORTHERN PLAINS AND UPPER GREAT LAKES REGION
THROUGH THE PERIOD. THE FORECAST AREA SHOULD REMAIN DRY THROUGH
SATURDAY NIGHT AS UPPER LEVEL RIDGE DOMINATES THE GREAT LAKES
REGION. THEN...FIRST IMPULSE BEGINS TO BREAK RIDGE DOWN SUNDAY AND
PROVIDE THE POSSIBILITY OF SHOWERS AND THUNDERSTORMS INTO THE
WESTERN HALF OF THE FORECAST AREA. WITH UPPER LEVEL RIDGE BREAKING
DOWN OVER THE UPPER MIDWEST AND GREAT LAKES REGION MEMORIAL DAY
AND TUESDAY...A SERIES OF SHORTWAVE TROUGHS EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL MOVE OVER THE AREA. THE 20.12Z
GFS/ECMWF/GEM INDICATE STRENGTH ISSUES WITH EACH SHORTWAVE
TROUGH...HOWEVER THE SHORTWAVE TROUGH SHOW BETTER MOISTURE
TRANSPORT/CONVERGENCE OVER THE REGION BY 00Z TUESDAY. WILL
CONTINUE WITH CHANCES OF SHOWERS AND THUNDERSTORMS ACROSS FORECAST
AREA...ESPECIALLY LATE MEMORIAL DAY INTO TUESDAY. TEMPERATURES
FRIDAY NIGHT INTO TUESDAY WILL BE SLIGHTLY ABOVE NORMAL...AS THE
GFS/ECMWF/GEM INDICATE 850MB TEMPERATURES IN THE PLUS 14 TO PLUS
16 DEGREES CELSIUS RANGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1149 PM CDT TUE MAY 20 2014
SKIES ARE CLEARING OUT AND WITH WINDS LIGHT...CONCERN EXISTS
ABOUT FOG. THERE HAS ALREADY BEEN PLENTY OF FOG REPORTS ACROSS
PORTIONS OF CENTRAL MINNESOTA. HOWEVER...THEY HAVE HAD A LONGER
PERIOD OF CLEARING AND TEMPERATURE/DEWPOINT SPREADS ARE MUCH
GREATER AT THE TAF SITES. IN ADDITION...BREEZIER NORTHWEST WINDS
OVER WESTERN MINNESOTA ARE WORKING THEIR WAY SOUTHEAST BEHIND A
COLD FRONT. SO IT SEEMS LIKE THE WINDOW OF OPPORTUNITY FOR FOG
WILL BE VERY SMALL AT EITHER TAF SITE...MAINLY 07-09Z AT RST AND
09-12Z AT LSE. FOR NOW HAVE NOT MENTIONED FOG IN THE TAFS BUT WILL
NEED MONITORING FOR THE EARLY MORNING HOURS.
OTHERWISE...THE DRY AIR ASSOCIATED WITH THE NORTHWEST WINDS WILL
HELP KEEP CONDITIONS VFR. NOTE THAT THERE SHOULD BE SOME CUMULUS
AROUND DURING THE DAYTIME...AND EVEN THE EVENING HOURS AT
LSE...BUT STILL ANTICIPATING THE SKIES TO STAY VFR. PLAN ON THOSE
AFOREMENTIONED NORTHWEST WINDS TO PICK UP TO 10-15 KT BY LATE
MORNING...WITH GUSTS TO 20 KT POSSIBLE. THE WINDS WILL SUBSIDE
SOME IN THE EVENING WITH LOSS OF DAYTIME HEATING.
&&
.HYDROLOGY...
ISSUED AT 258 PM CDT TUE MAY 20 2014
WATER LEVELS CONTINUE TO SLOWLY FALL ALONG THE MISSISSIPPI RIVER AND
FEW LOCATIONS REMAIN ABOVE FLOOD STAGE. THE WATER LEVELS WILL REMAIN
HIGH ALONG THE MISSISSIPPI RIVER THROUGH NEXT WEEK.
IN ADDITION...DUE TO RECENT RAINFALL AMOUNTS OF ONE TO TWO AND A
HALF INCHES IN THE HEADWATERS OF THE BLACK RIVER. THE BLACK RIVER
HAS RISEN ABOVE FLOOD OR IS EXPECTED TO RISE ABOVE FLOOD STAGE AT A
COUPLE LOCATIONS OVER THE NEXT COUPLE OF DAYS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...AJ
HYDROLOGY...DTJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
326 PM MDT WED MAY 21 2014
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY NIGHT)
ISSUED AT 319 PM MDT WED MAY 21 2014
VISIBLE AND RADAR IMAGERY IS SHOWING TSTMS DEVELOPING IN THE
NORTHERN LARAMIE RANGE. THESE STORMS WILL BE MOVING INTO AN
UNSTABLE ENVIRONMENT OVER THE PLAINS WITH DEWPOINTS OF 45-55F AND
SBCAPES IN THE 1500-2000 J/KG RANGE. WHILE FLOW ALOFT IS WEAKER
THAN YESTERDAY...DEEP LAYER SHEAR OF 35-40 KTS WILL STILL BE
SUFFICIENT FOR SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL. ADDED
THE POTENTIAL FOR LARGE HAIL OVER CONVERSE AND NIOBRARA COUNTIES AS
CONVECTIVE PARAMETERS ARE JUST AS FAVORABLE UP THERE AS FURTHER
SOUTH. STORM INITIATION HAS BEEN QUITE LIMITED SO FAR OVER THE
SOUTHERN LARAMIE RANGE...PERHAPS BECAUSE SFC WINDS ARE MORE
SOUTHERLY OVER LARAMIE COUNTY. THINKING THAT THE STRONGEST STORMS
WILL BE ACROSS SOUTHEAST WY THIS AFTN WITH CAPE DROPPING OFF TO
500-1000 OVER THE NEBRASKA PANHANDLE. WHILE LARGE HAIL WILL BE THE
PRIMARY THREAT...CANNOT RULE OUT AN ISOLATED WEAK TORNADO. 0-1KM
HELICITY VALUES ARE CURRENTLY LESS THAN 50 OVER MUCH OF THE PLAINS
WITH LCL HEIGHTS AROUND 1 KM. THE HRRR HAS BEEN CONSISTENT OVER THE
PAST FEW RUNS AT SHOWING THE MOST WIDESPREAD STORM CONVERGE TO THE
NORTH OF LARAMIE COUNTY...WHICH SEEMS ON TRACK SO FAR. STORMS WILL
BEGIN TO WIND DOWN BY LATE EVENING.
UPPER LEVEL LOW CONTINUES TO SPIN OVER THE DESERT SOUTHWEST TOMORROW
WITH SOUTH-TO-SOUTHWESTERLY FLOW ALOFT. THE MAIN CHANGE FOR THURS
WILL BE THAT THE WINDS ALOFT WEAKEN SUBSTANTIALLY...THUS THE DEEP
LAYER SHEAR DECREASES. 0-6KM SHEAR VALUES ARE DOWN TO 15-25 KTS
OVER THE PLAINS DURING THE AFTN. THERE IS STILL GOOD INSTABILITY
WITH SBCAPES AROUND OF 1500-1750...SO TSTMS WITH HEAVY RAIN WILL
PROBABLY THE PRIMARY THREAT WITH THE SLOWER STORM MOTIONS...AS
OPPOSED TO LARGE HAIL.
.LONG TERM...(FRIDAY THROUGH TUESDAY NIGHT)
ISSUED AT 319 PM MDT WED MAY 21 2014
THE UPPER LOW WILL SLOWLY MOVE EASTWARD FROM THE DESERT SOUTHWEST
TOWARD THE SOUTHERN PLAINS FRI-SUN. LOOKING AT A GOOD COVERAGE FOR
SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH THIS
TIME. HEAVY RAIN IS POSSIBLE WITH SOME OF THIS ACTIVITY...ESPECIALLY
FOR FRIDAY AND SUNDAY. SHORTWAVE RIDGING WILL MOVE OVERHEAD FOR
MONDAY...WITH WARMING TEMPERATURES AND MUCH DRIER CONDITIONS
ANTICIPATED. FLOW ALOFT WILL BACK TO THE SOUTHWEST ON TUESDAY WITH
SHORTWAVE ENERGY MOVING OVERHEAD IN THE AFTERNOON. WILL SEE A RETURN
OF SOME SHOWERS AND AFTERNOON THUNDERSTORMS MAINLY FOR SOUTHEAST
WYOMING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1211 PM MDT WED MAY 21 2014
WIDELY SCATTERED SHOWERS AND STORMS LOOK LIKELY TODAY BEGINNING
OVER THE MOUNTAINS EARLY THIS AFTERNOON...SHIFTING EAST ACROSS THE
PLAINS THROUGH THE EVENING. A FEW OF THE STORMS LOOK TO BE STRONG TO
SEVERE WITH HAIL AND STRONG DOWNBURST WINDS IN THE LATE
AFTERNOON...ESPECIALLY FROM KCYS TO KTOR AND POINTS EAST. COULD BE
A PERIOD OF IFR CIGS/VSBYS AFTER STORMS CLEAR TO THE EAST AND
MOIST UPSLOPE FLOW OCCURS THROUGH THE EARLY MORNING HOURS FOR THE
EASTERN TERMINALS. LOOKING ALSO AT MVFR CIGS SPILLING INTO THE
LARAMIE VALLEY FROM THE SOUTH OVERNIGHT. ANOTHER ROUND OF SHOWERS
AND STORMS IS EXPECTED FOR THURSDAY.
&&
.FIRE WEATHER...
ISSUED AT 319 PM MDT WED MAY 21 2014
NO FIRE WEATHER CONCERNS THROUGH THE WEEKEND. A MOIST AIRMASS WILL
BE IN PLACE ACROSS THE REGION THROUGH THE WEEKEND. THIS WILL CAUSE
SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP EVERY AFTERNOON.
MINIMUM AFTERNOON HUMIDITY VALUES WILL GENERALLY BE ABOVE 40 PERCENT
AND WINDS WILL BE LIGHT OUTSIDE OF THUNDERSTORMS.
&&
.HYDROLOGY..
ISSUED AT 319 PM MDT WED MAY 21 2014
NORMAL TO ABOVE NORMAL TEMPERATURES TO CONTINUE FOR THE REMAINDER OF
THE WEEK FOR THE FORECAST AREA...ALONG WITH A CONTINUED WET PATTERN.
RISES ON TRIBUTARIES AND HEADWATERS ARE EXPECTED FOR THE SNOWY AND
SIERRA MADRE RANGES WITH THESE WARM TEMPERATURES. THE LARAMIE
RIVER...UPPER NORTH PLATTE AND LITTLE SNAKE RIVERS WILL CONTINUE TO
SEE RISES TO AND IN SOME CASES INTO FLOOD STAGE THROUGH THE END OF
THE WEEK. RAIN CHANCES CONTINUE JUST ABOUT EVERY AFTERNOON AND
EVENING THROUGH THE WEEKEND. MODELS SHOW THE POTENTIAL FOR A PERIOD
OF MODERATE RAIN SATURDAY NIGHT AND SUNDAY FOR AREAS WEST OF THE
LARAMIE RANGE. THIS IS DUE TO A SLOW MOVING LOW PRESSURE SYSTEM
TRACKING ACROSS CENTRAL COLORADO. FREEZING LEVELS LOOK TO STAY ABOVE
10K FEET THROUGH THIS EVENT. SO RAPID SNOW MELT AND SIGNIFICANT
FLOODING/RIVER RISES COULD TAKE PLACE IF IT MATERIALIZES. WILL
CONTINUE TO MONITOR AND ISSUE ANY WATCHES AS THE EVENT DRAWS CLOSER.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM...RJM
AVIATION...RJM
FIRE WEATHER...FINCH
HYDROLOGY...FINCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1259 PM MDT WED MAY 21 2014
.UPDATE...
ISSUED AT 1252 PM MDT WED MAY 21 2014
A TORNADO WATCH HAS BEEN ISSUED FOR LARAMIE...PLATTE...AND GOSHEN
COUNTIES THROUGH 8PM. CONVECTION IS BEGINNING TO INITIATE ALONG THE
LARAMIE RANGE AND SOUTHWARD INTO THE LARAMIE COUNTY FOOTHILLS.
WHILE 0-1KM HELICITIES ARE NOT OVERLY IMPRESSIVE...BACKED WINDS TO
THE EAST OF AN OUTFLOW BOUNDARY THAT EXTENDS FROM GREELEY TO
CHEYENNE COULD ENHANCE LLVL HELICITIES/ROTATION.
ISSUED AT 1058 AM MDT WED MAY 21 2014
SEVERE THREAT CONTINUES TO LOOK ON TRACK FOR MUCH OF THE PLAINS
THIS AFTN. THE RUC SHOWS AROUND 1500 J/KG OF CAPE WITH CIN CLOSE
TO ZERO BY 21Z. FLOW ALOFT AND DEEP LAYER SHEAR IS WEAKER THAN
YESTERDAY...HOWEVER 35-40 KTS OF 0-6KM SHEAR DURING THE EARLY AFTN
IS SUFFICIENT FOR SUPERCELLS. THE MODELS DO INDICATE THIS SHEAR
DROPPING TO 25-30 KTS BY THIS EVENING HOWEVER. STILL LOOKING LIKE
HAIL WILL BE THE PREDOMINANT THREAT...ALONG WITH HEAVY RAIN AS
STORM MOTIONS WILL BE SLOWER THAN THE PAST FEW DAYS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 407 AM MDT WED MAY 21 2014
AN ACTIVE AFTERNOON AND EARLY EVENING AHEAD ACROSS SE WY AND THE
SRN HALF OF THE NEBRASKA PANHANDLE TODAY AS DIFFLUENT SSW FLOW
INTERACTS WITH A STALLED SFC BOUNDARY THAT IS LOCATED SOUTH OF THE
CWFA. BEFORE THEN...LINGERING MORNING CONVECTION HAS SHOWN SIGNS
OF WEAKENING OVER THE PAST FEW HOURS AND WILL CONTINUE TO DO SO
THROUGH SUNRISE. BY DAY BREAK...ONLY ANTICIPATE A FEW REMAINING
SHOWERS AND SPRINKLES. THESE TOO SHOULD COMPLETE DISSIPATE BY MID-
MORNING.
ATTENTION THEN TURNS TO SEVERE WEATHER POTENTIAL THIS AFTERNOON
AND EVENING. 09Z SFC ANALYSIS HAS STALLED BOUNDARY ALONG THE FRONT
RANGE FOOTHILLS. DEW POINTS TO THE EAST OF THIS FTR ARE IN THE MID
40S TO LOW 50S AND TO THE WEST IN THE 20S AND 30S. FOG PRODUCT
SHOWING PRONOUNCED AREAS OF LOW CLOUDS AND FOG FROM ALBANY COUNTY
EAST THRU THE SOUTHEAST WYOMING PLAINS. SYNOPTICALLY...THIS IS
OCCURRING AHEAD OF AN UPPER CLOSED LOW DETACHED FROM THE MAIN
WESTERLIES SPINNING OVR THE GREAT BASIN. THE COMBINATION OF THE
PATTERN...BOTH SFC AND ALOFT COMBINED WITH SOUPY DEW POINTS AND AM
FOG/LOW CLOUDS IS A SURE FIRE BET FOR A SEVERE WEATHER SET-UP THIS
AFTERNOON/EARLY EVENING. THE QUESTION IS NOT IF IT WILL
OCCUR...ITS MORE TRYING TO PIN DOWN SPECIFICS OF WHERE AND HOW
STRONG. GLOBAL MODELS ARE SIMILAR IN SHOWING CAP ERODING BY AROUND
2 PM WITH CONVECTIVE INITIATION OVR ALBANY COUNTY AND THE LARAMIE
RANGE AS SHORTWAVE ENERGY STREAMS OVERHEAD AND CONVECTIVE TEMPS
ARE REACHED. STORM MOTION WILL BE SOUTHWESTERLY INITIALLY...BUT
WILL DEVIATE MORE WESTERLY AS THE UPDRAFTS STRENGTHEN. STORM
MOTIONS MAY EVEN TURN TOWARDS THE ESE OVR THE SRN PANHANDLE THIS
EVENING. AFTERNOON 0-6 KM SHEAR VALUES ALONG WITH A VEERING
PROFILE WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS TO BE THE
PRIMARY THUNDERSTORM MODE. SO...AS THESE THUNDERSTORMS EMERGE FROM
THE TERRAIN ONTO THE SOUTHEAST WYOMING HIGH PLAINS...THEY WILL
ENCOUNTER A MUCH BETTER AIR MASS...WITH THE STRONGEST STORMS
DEVIATING RIGHT OF THE MEAN FLOW. STORMS PUSH INTO
PLATTE/GOSHEN/LARAMIE COUNTIES THRU THE LATE AFTERNOON AND INTO
THE CENTRAL/SOUTHERN NEBRASKA PANHANDLE BY THIS EVENING. PROGD
SBCAPES PEAK AT 1200-1500 J/KG OVR THIS SAME AREA. LARGE HAIL WILL
BE THE PRIMARY HAZARD ASSOCIATED WITH THE LARGEST STORMS AS STEEP
LAPSE RATES IN THE HAIL GROWTH REGION COMBINE WITH FREEZING LEVELS
THAT ARE LOWER THAN 10 KFT AGL. ALTHOUGH NOT RULING DAMAGING WINDS
OUT...THE MOIST SUB-CLOUD AIR MASS WILL INHIBIT COVERAGE AND
SEVERITY. LOW LCLS ALONG WITH 0-1KM HELICITY VALUES THAT CLIMB
ABOVE 100 M2/S2 ALSO POINT TO THE POSSIBILITY OF A FEW TORNADOES.
MODELS SUGGEST AREAS FROM SRN PLATTE/GOSHEN INTO ERN LARAMIE AND
KIMBALL COUNTIES OF HAVING THE BEST SHOT. CONVECTION WILL LIKELY
AGAIN LINGER INTO THE OVERNIGHT HOURS...THOUGH COVERAGE/STRENGTH
WILL BE SIGNIFICANTLY LESS.
NOT MUCH PATTERN CHANGE FOR THURSDAY AS THE UPPER-LOW MOVES TO NR
THE CA/AZ STATELINE BY LATE IN THE DAY. WINDS ALOFT WILL BE
NOTICEABLY LIGHTER ON THURSDAY HOWEVER WITH 0-6KM SHEAR VALUES
FALLING TO 15-25 KNOTS THURSDAY AFTERNOON. SBCAPES AGAIN WILL CLIMB
ABOVE 1000 J/KG THURSDAY. HOWEVER...WITH LIGHTER WINDS ALOFT THINK
THAT CONVECTION WILL BE LESS DISCRETE COMPARED TO WEDNESDAYS. SFC
DEWPOINTS WILL REMAIN NEARLY UNCHANGED AS THE STATIONARY BOUNDARY
REMAINS MOSTLY SOUTH AND WEST OF THE CWFA. STILL KEPT RIBBON OF
SEVERE MENTION ACROSS EXTREME SE WYOMING AND THE SRN NEBRASKA
PANHANDLE WHICH WILL BE IN CLOSEST PROXIMITY OF THE BETTER SHEAR
VALUES. SLOWER STORM MOTION WILL YIELD MORE EFFICIENT RAIN PRODUCERS
ON THURSDAY.
UPPER-LOW MOVES LESS THAN 200 MILES IN 24 HOURS FOR FRIDAY. MODELS
ARE CONSISTENT IN LIFTING A STRONGER SHORTWAVE OVR THE AREA. WINDS
ALOFT WILL BE EVEN LESS ON FRIDAY. THE MAIN CONCERN ON FRIDAY WILL
AGAIN BE EFFICIENT RAIN PRODUCERS AND HEAVY RAIN PRODUCERS AS
LAYERED INSTABILITIES BECOME MORE SKINNY. ALTHOUGH SOME SMALL HAIL
MIGHT BE A POSSIBILITY ON FRIDAY...DO NOT ANTICIPATE SEVERE WEATHER
THREAT AT THIS POINT.
TEMPERATURES WILL REMAIN CONSISTENT THRU THE PERIOD WITH HIGHS IN
LOWER ELEVATIONS HOLDING BETWEEN 65 AND 75 DEGREES.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 407 AM MDT WED MAY 21 2014
SLOW MOVING UPPER LOW WILL CONTINUE TO AFFECT THE WEATHER OVER
THE CWA SATURDAY AND SUNDAY AS IT LIFTS NORTHEAST FROM ARIZONA...
FINALLY REACHING THE CENTRAL PLAINS EARLY MONDAY. THIS SYSTEM WILL
KEEP CHANCES FOR SHOWERS AND TSTMS GOING THROUGH THAT TIME THOUGH
THE INTENSITY OF THE STORMS LOOKS TO DIMINISH. A DRIER REGIME
SHOULD ARRIVE FOR EARLY NEXT WEEK AS THE UPPER LOW MOVES EAST AND
SHORT UPPER RIDGING BUILDS OVER THE REGION. SW UPPER FLOW MAY SET
UP TUESDAY WHICH COULD ALLOW FOR CONVECTION TO RETURN AT THAT
TIME. TEMPERATURES REMAINING MILD THROUGH THE WEEKEND THEN WARMING
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1211 PM MDT WED MAY 21 2014
WIDELY SCATTERED SHOWERS AND STORMS LOOK LIKELY TODAY BEGINNING
OVER THE MOUNTAINS EARLY THIS AFTERNOON...SHIFTING EAST ACROSS THE
PLAINS THROUGH THE EVENING. A FEW OF THE STORMS LOOK TO BE STRONG TO
SEVERE WITH HAIL AND STRONG DOWNBURST WINDS IN THE LATE
AFTERNOON...ESPECIALLY FROM KCYS TO KTOR AND POINTS EAST. COULD BE
A PERIOD OF IFR CIGS/VSBYS AFTER STORMS CLEAR TO THE EAST AND
MOIST UPSLOPE FLOW OCCURS THROUGH THE EARLY MORNING HOURS FOR THE
EASTERN TERMINALS. LOOKING ALSO AT MVFR CIGS SPILLING INTO THE
LARAMIE VALLEY FROM THE SOUTH OVERNIGHT. ANOTHER ROUND OF SHOWERS
AND STORMS IS EXPECTED FOR THURSDAY.
&&
.FIRE WEATHER...
ISSUED AT 407 AM MDT WED MAY 21 2014
FIRE CONCERNS TO REMAIN MINIMAL FOR THE REST OF THE WEEK WITH
CONDITIONS AND FUELS EXPECTED TO REMAIN NON-CRITICAL. SCATTERED
AFTERNOON AND EVENING THUNDERSTORMS WILL OCCUR ALONG AND EAST OF
THE LARAMIE RANGE MOST DAYS WITH VERY GOOD CHANCES FOR WETTING
RAINS. A MORE WIDESPREAD RAIN EVENT SATURDAY NIGHT AND SUNDAY WILL
CONTINUE TO SUPPRESS FIRE WEATHER CONCERNS THRU THE MEMORIAL DAY
WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...FINCH
SHORT TERM...HAHN
LONG TERM...RE
AVIATION...RJM
FIRE WEATHER...HAHN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1211 PM MDT WED MAY 21 2014
.UPDATE...
ISSUED AT 1058 AM MDT WED MAY 21 2014
SEVERE THREAT CONTINUES TO LOOK ON TRACK FOR MUCH OF THE PLAINS
THIS AFTN. THE RUC SHOWS AROUND 1500 J/KG OF CAPE WITH CIN CLOSE
TO ZERO BY 21Z. FLOW ALOFT AND DEEP LAYER SHEAR IS WEAKER THAN
YESTERDAY...HOWEVER 35-40 KTS OF 0-6KM SHEAR DURING THE EARLY AFTN
IS SUFFICIENT FOR SUPERCELLS. THE MODELS DO INDICATE THIS SHEAR
DROPPING TO 25-30 KTS BY THIS EVENING HOWEVER. STILL LOOKING LIKE
HAIL WILL BE THE PREDOMINANT THREAT...ALONG WITH HEAVY RAIN AS
STORM MOTIONS WILL BE SLOWER THAN THE PAST FEW DAYS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 407 AM MDT WED MAY 21 2014
AN ACTIVE AFTERNOON AND EARLY EVENING AHEAD ACROSS SE WY AND THE
SRN HALF OF THE NEBRASKA PANHANDLE TODAY AS DIFFLUENT SSW FLOW
INTERACTS WITH A STALLED SFC BOUNDARY THAT IS LOCATED SOUTH OF THE
CWFA. BEFORE THEN...LINGERING MORNING CONVECTION HAS SHOWN SIGNS
OF WEAKENING OVER THE PAST FEW HOURS AND WILL CONTINUE TO DO SO
THROUGH SUNRISE. BY DAY BREAK...ONLY ANTICIPATE A FEW REMAINING
SHOWERS AND SPRINKLES. THESE TOO SHOULD COMPLETE DISSIPATE BY MID-
MORNING.
ATTENTION THEN TURNS TO SEVERE WEATHER POTENTIAL THIS AFTERNOON
AND EVENING. 09Z SFC ANALYSIS HAS STALLED BOUNDARY ALONG THE FRONT
RANGE FOOTHILLS. DEW POINTS TO THE EAST OF THIS FTR ARE IN THE MID
40S TO LOW 50S AND TO THE WEST IN THE 20S AND 30S. FOG PRODUCT
SHOWING PRONOUNCED AREAS OF LOW CLOUDS AND FOG FROM ALBANY COUNTY
EAST THRU THE SOUTHEAST WYOMING PLAINS. SYNOPTICALLY...THIS IS
OCCURRING AHEAD OF AN UPPER CLOSED LOW DETACHED FROM THE MAIN
WESTERLIES SPINNING OVR THE GREAT BASIN. THE COMBINATION OF THE
PATTERN...BOTH SFC AND ALOFT COMBINED WITH SOUPY DEW POINTS AND AM
FOG/LOW CLOUDS IS A SURE FIRE BET FOR A SEVERE WEATHER SET-UP THIS
AFTERNOON/EARLY EVENING. THE QUESTION IS NOT IF IT WILL
OCCUR...ITS MORE TRYING TO PIN DOWN SPECIFICS OF WHERE AND HOW
STRONG. GLOBAL MODELS ARE SIMILAR IN SHOWING CAP ERODING BY AROUND
2 PM WITH CONVECTIVE INITIATION OVR ALBANY COUNTY AND THE LARAMIE
RANGE AS SHORTWAVE ENERGY STREAMS OVERHEAD AND CONVECTIVE TEMPS
ARE REACHED. STORM MOTION WILL BE SOUTHWESTERLY INITIALLY...BUT
WILL DEVIATE MORE WESTERLY AS THE UPDRAFTS STRENGTHEN. STORM
MOTIONS MAY EVEN TURN TOWARDS THE ESE OVR THE SRN PANHANDLE THIS
EVENING. AFTERNOON 0-6 KM SHEAR VALUES ALONG WITH A VEERING
PROFILE WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS TO BE THE
PRIMARY THUNDERSTORM MODE. SO...AS THESE THUNDERSTORMS EMERGE FROM
THE TERRAIN ONTO THE SOUTHEAST WYOMING HIGH PLAINS...THEY WILL
ENCOUNTER A MUCH BETTER AIR MASS...WITH THE STRONGEST STORMS
DEVIATING RIGHT OF THE MEAN FLOW. STORMS PUSH INTO
PLATTE/GOSHEN/LARAMIE COUNTIES THRU THE LATE AFTERNOON AND INTO
THE CENTRAL/SOUTHERN NEBRASKA PANHANDLE BY THIS EVENING. PROGD
SBCAPES PEAK AT 1200-1500 J/KG OVR THIS SAME AREA. LARGE HAIL WILL
BE THE PRIMARY HAZARD ASSOCIATED WITH THE LARGEST STORMS AS STEEP
LAPSE RATES IN THE HAIL GROWTH REGION COMBINE WITH FREEZING LEVELS
THAT ARE LOWER THAN 10 KFT AGL. ALTHOUGH NOT RULING DAMAGING WINDS
OUT...THE MOIST SUB-CLOUD AIR MASS WILL INHIBIT COVERAGE AND
SEVERITY. LOW LCLS ALONG WITH 0-1KM HELICITY VALUES THAT CLIMB
ABOVE 100 M2/S2 ALSO POINT TO THE POSSIBILITY OF A FEW TORNADOES.
MODELS SUGGEST AREAS FROM SRN PLATTE/GOSHEN INTO ERN LARAMIE AND
KIMBALL COUNTIES OF HAVING THE BEST SHOT. CONVECTION WILL LIKELY
AGAIN LINGER INTO THE OVERNIGHT HOURS...THOUGH COVERAGE/STRENGTH
WILL BE SIGNIFICANTLY LESS.
NOT MUCH PATTERN CHANGE FOR THURSDAY AS THE UPPER-LOW MOVES TO NR
THE CA/AZ STATELINE BY LATE IN THE DAY. WINDS ALOFT WILL BE
NOTICEABLY LIGHTER ON THURSDAY HOWEVER WITH 0-6KM SHEAR VALUES
FALLING TO 15-25 KNOTS THURSDAY AFTERNOON. SBCAPES AGAIN WILL CLIMB
ABOVE 1000 J/KG THURSDAY. HOWEVER...WITH LIGHTER WINDS ALOFT THINK
THAT CONVECTION WILL BE LESS DISCRETE COMPARED TO WEDNESDAYS. SFC
DEWPOINTS WILL REMAIN NEARLY UNCHANGED AS THE STATIONARY BOUNDARY
REMAINS MOSTLY SOUTH AND WEST OF THE CWFA. STILL KEPT RIBBON OF
SEVERE MENTION ACROSS EXTREME SE WYOMING AND THE SRN NEBRASKA
PANHANDLE WHICH WILL BE IN CLOSEST PROXIMITY OF THE BETTER SHEAR
VALUES. SLOWER STORM MOTION WILL YIELD MORE EFFICIENT RAIN PRODUCERS
ON THURSDAY.
UPPER-LOW MOVES LESS THAN 200 MILES IN 24 HOURS FOR FRIDAY. MODELS
ARE CONSISTENT IN LIFTING A STRONGER SHORTWAVE OVR THE AREA. WINDS
ALOFT WILL BE EVEN LESS ON FRIDAY. THE MAIN CONCERN ON FRIDAY WILL
AGAIN BE EFFICIENT RAIN PRODUCERS AND HEAVY RAIN PRODUCERS AS
LAYERED INSTABILITIES BECOME MORE SKINNY. ALTHOUGH SOME SMALL HAIL
MIGHT BE A POSSIBILITY ON FRIDAY...DO NOT ANTICIPATE SEVERE WEATHER
THREAT AT THIS POINT.
TEMPERATURES WILL REMAIN CONSISTENT THRU THE PERIOD WITH HIGHS IN
LOWER ELEVATIONS HOLDING BETWEEN 65 AND 75 DEGREES.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 407 AM MDT WED MAY 21 2014
SLOW MOVING UPPER LOW WILL CONTINUE TO AFFECT THE WEATHER OVER
THE CWA SATURDAY AND SUNDAY AS IT LIFTS NORTHEAST FROM ARIZONA...
FINALLY REACHING THE CENTRAL PLAINS EARLY MONDAY. THIS SYSTEM WILL
KEEP CHANCES FOR SHOWERS AND TSTMS GOING THROUGH THAT TIME THOUGH
THE INTENSITY OF THE STORMS LOOKS TO DIMINISH. A DRIER REGIME
SHOULD ARRIVE FOR EARLY NEXT WEEK AS THE UPPER LOW MOVES EAST AND
SHORT UPPER RIDGING BUILDS OVER THE REGION. SW UPPER FLOW MAY SET
UP TUESDAY WHICH COULD ALLOW FOR CONVECTION TO RETURN AT THAT
TIME. TEMPERATURES REMAINING MILD THROUGH THE WEEKEND THEN WARMING
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1211 PM MDT WED MAY 21 2014
WIDELY SCATTERED SHOWERS AND STORMS LOOK LIKELY TODAY BEGINNING
OVER THE MOUNTAINS EARLY THIS AFTERNOON...SHIFTING EAST ACROSS THE
PLAINS THROUGH THE EVENING. A FEW OF THE STORMS LOOK TO BE STRONG TO
SEVERE WITH HAIL AND STRONG DOWNBURST WINDS IN THE LATE
AFTERNOON...ESPECIALLY FROM KCYS TO KTOR AND POINTS EAST. COULD BE
A PERIOD OF IFR CIGS/VSBYS AFTER STORMS CLEAR TO THE EAST AND
MOIST UPSLOPE FLOW OCCURS THROUGH THE EARLY MORNING HOURS FOR THE
EASTERN TERMINALS. LOOKING ALSO AT MVFR CIGS SPILLING INTO THE
LARAMIE VALLEY FROM THE SOUTH OVERNIGHT. ANOTHER ROUND OF SHOWERS
AND STORMS IS EXPECTED FOR THURSDAY.
&&
.FIRE WEATHER...
ISSUED AT 407 AM MDT WED MAY 21 2014
FIRE CONCERNS TO REMAIN MINIMAL FOR THE REST OF THE WEEK WITH
CONDITIONS AND FUELS EXPECTED TO REMAIN NON-CRITICAL. SCATTERED
AFTERNOON AND EVENING THUNDERSTORMS WILL OCCUR ALONG AND EAST OF
THE LARAMIE RANGE MOST DAYS WITH VERY GOOD CHANCES FOR WETTING
RAINS. A MORE WIDESPREAD RAIN EVENT SATURDAY NIGHT AND SUNDAY WILL
CONTINUE TO SUPPRESS FIRE WEATHER CONCERNS THRU THE MEMORIAL DAY
WEEKEND.
&&
.HYDROLOGY...
ISSUED AT 407 AM MDT WED MAY 21 2014
NORMAL TO ABOVE NORMAL TEMPERATURES TO CONTINUE FOR THE REMAINDER
OF THE WEEK FOR THE FORECAST AREA...ALONG WITH A CONTINUED WET
PATTERN. RISES ON TRIBUTARIES AND HEADWATERS ARE EXPECTED FOR THE
SNOWY AND SIERRA MADRE RANGES WITH THESE WARM TEMPERATURES. THE
LARAMIE RIVER...UPPER NORTH PLATTE AND LITTLE SNAKE RIVERS WILL CONTINUE
TO SEE RISES TO AND IN SOME CASES INTO FLOOD STAGE THROUGH THE
END OF THE WEEK. RAIN CHANCES CONTINUE JUST ABOUT EVERY AFTERNOON
AND EVENING THROUGH THE WEEKEND. MODELS CONTINUE TO SUGGEST A
PERIOD OF MODERATE RAIN SATURDAY NIGHT AND SUNDAY FOR AREAS WEST
OF THE LARAMIE RANGE. THIS IS DUE TO A SLOW MOVING LOW PRESSURE
SYSTEM TRACKING ACROSS CENTRAL COLORADO. FREEZING LEVELS LOOK TO
STAY ABOVE 10K FEET THROUGH THIS EVENT. SO RAPID SNOW MELT AND
SIGNIFICANT FLOODING/RIVER RISES COULD TAKE PLACE IF IT
MATERIALIZES. WILL CONTINUE TO MONITOR AND ISSUE ANY WATCHES AS
THE EVENT DRAWS CLOSER.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...FINCH
SHORT TERM...HAHN
LONG TERM...RE
AVIATION...RJM
FIRE WEATHER...HAHN
HYDROLOGY...HAHN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1114 AM MDT WED MAY 21 2014
.UPDATE...
ISSUED AT 1058 AM MDT WED MAY 21 2014
SEVERE THREAT CONTINUES TO LOOK ON TRACK FOR MUCH OF THE PLAINS
THIS AFTN. THE RUC SHOWS AROUND 1500 J/KG OF CAPE WITH CIN CLOSE
TO ZERO BY 21Z. FLOW ALOFT AND DEEP LAYER SHEAR IS WEAKER THAN
YESTERDAY...HOWEVER 35-40 KTS OF 0-6KM SHEAR DURING THE EARLY AFTN
IS SUFFICIENT FOR SUPERCELLS. THE MODELS DO INDICATE THIS SHEAR
DROPPING TO 25-30 KTS BY THIS EVENING HOWEVER. STILL LOOKING LIKE
HAIL WILL BE THE PREDOMINANT THREAT...ALONG WITH HEAVY RAIN AS
STORM MOTIONS WILL BE SLOWER THAN THE PAST FEW DAYS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 407 AM MDT WED MAY 21 2014
AN ACTIVE AFTERNOON AND EARLY EVENING AHEAD ACROSS SE WY AND THE
SRN HALF OF THE NEBRASKA PANHANDLE TODAY AS DIFFLUENT SSW FLOW
INTERACTS WITH A STALLED SFC BOUNDARY THAT IS LOCATED SOUTH OF THE
CWFA. BEFORE THEN...LINGERING MORNING CONVECTION HAS SHOWN SIGNS
OF WEAKENING OVER THE PAST FEW HOURS AND WILL CONTINUE TO DO SO
THROUGH SUNRISE. BY DAY BREAK...ONLY ANTICIPATE A FEW REMAINING
SHOWERS AND SPRINKLES. THESE TOO SHOULD COMPLETE DISSIPATE BY MID-
MORNING.
ATTENTION THEN TURNS TO SEVERE WEATHER POTENTIAL THIS AFTERNOON
AND EVENING. 09Z SFC ANALYSIS HAS STALLED BOUNDARY ALONG THE FRONT
RANGE FOOTHILLS. DEW POINTS TO THE EAST OF THIS FTR ARE IN THE MID
40S TO LOW 50S AND TO THE WEST IN THE 20S AND 30S. FOG PRODUCT
SHOWING PRONOUNCED AREAS OF LOW CLOUDS AND FOG FROM ALBANY COUNTY
EAST THRU THE SOUTHEAST WYOMING PLAINS. SYNOPTICALLY...THIS IS
OCCURRING AHEAD OF AN UPPER CLOSED LOW DETACHED FROM THE MAIN
WESTERLIES SPINNING OVR THE GREAT BASIN. THE COMBINATION OF THE
PATTERN...BOTH SFC AND ALOFT COMBINED WITH SOUPY DEW POINTS AND AM
FOG/LOW CLOUDS IS A SURE FIRE BET FOR A SEVERE WEATHER SET-UP THIS
AFTERNOON/EARLY EVENING. THE QUESTION IS NOT IF IT WILL
OCCUR...ITS MORE TRYING TO PIN DOWN SPECIFICS OF WHERE AND HOW
STRONG. GLOBAL MODELS ARE SIMILAR IN SHOWING CAP ERODING BY AROUND
2 PM WITH CONVECTIVE INITIATION OVR ALBANY COUNTY AND THE LARAMIE
RANGE AS SHORTWAVE ENERGY STREAMS OVERHEAD AND CONVECTIVE TEMPS
ARE REACHED. STORM MOTION WILL BE SOUTHWESTERLY INITIALLY...BUT
WILL DEVIATE MORE WESTERLY AS THE UPDRAFTS STRENGTHEN. STORM
MOTIONS MAY EVEN TURN TOWARDS THE ESE OVR THE SRN PANHANDLE THIS
EVENING. AFTERNOON 0-6 KM SHEAR VALUES ALONG WITH A VEERING
PROFILE WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS TO BE THE
PRIMARY THUNDERSTORM MODE. SO...AS THESE THUNDERSTORMS EMERGE FROM
THE TERRAIN ONTO THE SOUTHEAST WYOMING HIGH PLAINS...THEY WILL
ENCOUNTER A MUCH BETTER AIR MASS...WITH THE STRONGEST STORMS
DEVIATING RIGHT OF THE MEAN FLOW. STORMS PUSH INTO
PLATTE/GOSHEN/LARAMIE COUNTIES THRU THE LATE AFTERNOON AND INTO
THE CENTRAL/SOUTHERN NEBRASKA PANHANDLE BY THIS EVENING. PROGD
SBCAPES PEAK AT 1200-1500 J/KG OVR THIS SAME AREA. LARGE HAIL WILL
BE THE PRIMARY HAZARD ASSOCIATED WITH THE LARGEST STORMS AS STEEP
LAPSE RATES IN THE HAIL GROWTH REGION COMBINE WITH FREEZING LEVELS
THAT ARE LOWER THAN 10 KFT AGL. ALTHOUGH NOT RULING DAMAGING WINDS
OUT...THE MOIST SUB-CLOUD AIR MASS WILL INHIBIT COVERAGE AND
SEVERITY. LOW LCLS ALONG WITH 0-1KM HELICITY VALUES THAT CLIMB
ABOVE 100 M2/S2 ALSO POINT TO THE POSSIBILITY OF A FEW TORNADOES.
MODELS SUGGEST AREAS FROM SRN PLATTE/GOSHEN INTO ERN LARAMIE AND
KIMBALL COUNTIES OF HAVING THE BEST SHOT. CONVECTION WILL LIKELY
AGAIN LINGER INTO THE OVERNIGHT HOURS...THOUGH COVERAGE/STRENGTH
WILL BE SIGNIFICANTLY LESS.
NOT MUCH PATTERN CHANGE FOR THURSDAY AS THE UPPER-LOW MOVES TO NR
THE CA/AZ STATELINE BY LATE IN THE DAY. WINDS ALOFT WILL BE
NOTICEABLY LIGHTER ON THURSDAY HOWEVER WITH 0-6KM SHEAR VALUES
FALLING TO 15-25 KNOTS THURSDAY AFTERNOON. SBCAPES AGAIN WILL CLIMB
ABOVE 1000 J/KG THURSDAY. HOWEVER...WITH LIGHTER WINDS ALOFT THINK
THAT CONVECTION WILL BE LESS DISCRETE COMPARED TO WEDNESDAYS. SFC
DEWPOINTS WILL REMAIN NEARLY UNCHANGED AS THE STATIONARY BOUNDARY
REMAINS MOSTLY SOUTH AND WEST OF THE CWFA. STILL KEPT RIBBON OF
SEVERE MENTION ACROSS EXTREME SE WYOMING AND THE SRN NEBRASKA
PANHANDLE WHICH WILL BE IN CLOSEST PROXIMITY OF THE BETTER SHEAR
VALUES. SLOWER STORM MOTION WILL YIELD MORE EFFICIENT RAIN PRODUCERS
ON THURSDAY.
UPPER-LOW MOVES LESS THAN 200 MILES IN 24 HOURS FOR FRIDAY. MODELS
ARE CONSISTENT IN LIFTING A STRONGER SHORTWAVE OVR THE AREA. WINDS
ALOFT WILL BE EVEN LESS ON FRIDAY. THE MAIN CONCERN ON FRIDAY WILL
AGAIN BE EFFICIENT RAIN PRODUCERS AND HEAVY RAIN PRODUCERS AS
LAYERED INSTABILITIES BECOME MORE SKINNY. ALTHOUGH SOME SMALL HAIL
MIGHT BE A POSSIBILITY ON FRIDAY...DO NOT ANTICIPATE SEVERE WEATHER
THREAT AT THIS POINT.
TEMPERATURES WILL REMAIN CONSISTENT THRU THE PERIOD WITH HIGHS IN
LOWER ELEVATIONS HOLDING BETWEEN 65 AND 75 DEGREES.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 407 AM MDT WED MAY 21 2014
SLOW MOVING UPPER LOW WILL CONTINUE TO AFFECT THE WEATHER OVER
THE CWA SATURDAY AND SUNDAY AS IT LIFTS NORTHEAST FROM ARIZONA...
FINALLY REACHING THE CENTRAL PLAINS EARLY MONDAY. THIS SYSTEM WILL
KEEP CHANCES FOR SHOWERS AND TSTMS GOING THROUGH THAT TIME THOUGH
THE INTENSITY OF THE STORMS LOOKS TO DIMINISH. A DRIER REGIME
SHOULD ARRIVE FOR EARLY NEXT WEEK AS THE UPPER LOW MOVES EAST AND
SHORT UPPER RIDGING BUILDS OVER THE REGION. SW UPPER FLOW MAY SET
UP TUESDAY WHICH COULD ALLOW FOR CONVECTION TO RETURN AT THAT
TIME. TEMPERATURES REMAINING MILD THROUGH THE WEEKEND THEN WARMING
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 407 AM MDT WED MAY 21 2014
PATCHY LIFR CIGS WILL AFFECT MAINLY KCYS EARLY THIS MORNING THEN
LIFT TO VFR BY LATE MORNING. WIDELY SCTD SHOWERS AND TSTRMS
EXPECTED TO MOVE OVER PARTS OF SE WY AND THE NEB PANHANDLE THIS
AFTERNOON AND EVENING OTHERWISE VFR EXPECTED OVERALL. LIFR CIGS
MAY RETURN TO KCYS LATE WEDS NIGHT IN SFC UPSLOPE FLOW.
&&
.FIRE WEATHER...
ISSUED AT 407 AM MDT WED MAY 21 2014
FIRE CONCERNS TO REMAIN MINIMAL FOR THE REST OF THE WEEK WITH
CONDITIONS AND FUELS EXPECTED TO REMAIN NON-CRITICAL. SCATTERED
AFTERNOON AND EVENING THUNDERSTORMS WILL OCCUR ALONG AND EAST OF
THE LARAMIE RANGE MOST DAYS WITH VERY GOOD CHANCES FOR WETTING
RAINS. A MORE WIDESPREAD RAIN EVENT SATURDAY NIGHT AND SUNDAY WILL
CONTINUE TO SUPPRESS FIRE WEATHER CONCERNS THRU THE MEMORIAL DAY
WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...FINCH
SHORT TERM...HAHN
LONG TERM...RE
AVIATION...RE
FIRE WEATHER...HAHN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1016 PM MDT TUE MAY 20 2014
.UPDATE...
ISSUED AT 944 PM MDT TUE MAY 20 2014
GRIDDED FORECASTS UPDATED FOR THE OVERNIGHT TO ACCOUNT FOR SPATIAL
COVERAGE OF ISOLATED SHOWERS AND THUNDERSTORMS EAST OF A DOUGLAS
TO PINE BLUFFS LINE. TEMPERATURE AND DEWPOINT SPREADS CONTINUE
TO NARROW WITH FOG ALREADY REPORTED AT CHADRON...AND WITH THE
NAM INDICATING BOUNDARY LAYER WINDS FROM THE EAST AND SOUTHEAST
LATE TONIGHT...AND BOUNDARY LAYER RELATIVE HUMIDITIES FROM 70 TO
100 PERCENT...HAVE ADDED MENTION OF AREAS OF FOG...WITH LOWER
VISIBILITIES FROM DOUGLAS TO LUSK WHERE MORE RAIN FELL...AND
WHERE BOUNDARY LAYER HUMIDITIES ARE PROGGED NEAR 100 PERCENT NEAR
DAYBREAK. 64/RUBIN
UPDATE ISSUED AT 716 PM MDT TUE MAY 20 2014
BEGAN PEELING OUR SOUTHEAST WYOMING COUNTIES OUT OF THE SEVERE
THUNDERSTORM WATCH. CONVECTION MAINLY CONFINED TO THE PANHANDLE
WITH SOME LIGHT CONVECTION OVER NORTHERN PLATTE AND GOSHEN
COUNTIES. THIS CONVECTION IN SOUTHEAST WYOMING APPEARS TO BE
WEAKENING...THEREFORE THE CANCELLATION OF THE WATCH. UPDATES HAVE
BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 300 PM MDT TUE MAY 20 2014
FORECAST CHALLENGES CONTINUE TO BE SEVERE THUNDERSTORM CHANCES
TODAY AND WEDNESDAY.
CURRENTLY...FAIRLY QUIET RIGHT NOW EARLY THIS AFTERNOON ACROSS THE
CWFA. STARTING TO GET SOME LIGHTNING STRIKES FROM CONVECTION
DEVELOPING OVER THE LARAMIE RANGE. WOULD EXPECT THIS TO CONTINUE
TO INCREASE IN COVERAGE AND INTENSITY AS THE AFTERNOON CONTINUES.
EASTERLY TO SOUTHEASTERLY SURFACE WINDS ACROSS EASTERN PORTIONS OF
THE CWFA WITH PRETTY GOOD DEWPOINTS. GETTING UPPER 40S OUT BY
CHADRON...47 HERE AT CHEYENNE AND 43 UP BY DOUGLAS. TEMPERATURES
IN THE MID 60S JUST ABOUT EVERYWHERE EAST OF THE LARAMIE RANGE.
LATEST SPC MESOANALYSIS SHOWING SURFACE BASED CAPES AROUND 1000
J/KG ALONG THE LARAMIE RANGE WITH NO CONVECTIVE INHIBITION
ANALYZED AT THIS TIME. LIFTED INDICES NEAR ZERO JUST ABOUT
EVERYWHERE WITH -3C IN THE GENERAL LOCATION WHERE CONVECTION IS
INITIATING. LATEST WATER VAPOR IMAGERY SHOWING CLOSED LOW MOVING
INTO CENTRAL NEVADA THIS AFTERNOON.
FOR LATER THIS AFTERNOON...LOOKING AT LIFTED INDICES TO CONTINUE
FALLING TO -3 TO -4C ACROSS MUCH OF THE AREA EAST OF THE LARAMIE
RANGE BY 00Z. LATEST HRRR CONVECTIVE FORECAST KEYED INTO A
SUPERCELL DEVELOPING NEAR WHEATLAND THIS AFTERNOON...THEN TRACKING
EAST ACROSS TORRINGTON BY 23Z AND THEN INTO SOUTHERN SIOUX COUNTY
BY THE 00-01Z TIME FRAME. CONVECTION FAIRLY WIDESPREAD ACROSS THE
NORTHERN PANHANDLE AFTER 00Z. HIGH 0-6KM BULK SHEAR FORECASTS OF
60 TO 65KTS SHOULD SUPPORT VERY LARGE HAIL DEVELOPMENT WITH STORMS
THAT GET GOING THIS AFTERNOON. ONE LAST ITEM WITH THE STORMS
TODAY. FORECAST STORM MOTIONS ARE LOW...GENERALLY 10KTS OR LESS.
SO WE NEED TO WATCH FOR HEAVY RAIN/POSSIBLE LOCALIZED FLASH
FLOODING.
PRETTY MUCH A REPEAT FOR WEDNESDAY AFTERNOON. SEVERE THUNDERSTORM
POTENTIAL WILL CONTINUE FOR LOCATIONS EAST OF THE LARAMIE RANGE.
MAYBE MORE DOWN IN THE SOUTHERN PART OF THE CWFA DOWN HERE NEAR
CHEYENNE.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 300 PM MDT TUE MAY 20 2014
MEDIUM RANGE GUIDANCE IS IN EXCELLENT AGREEMENT WITH A POTENT CUTOFF
LOW OVER THE 4 CORNERS EARLY IN THE FCST PERIOD. NOT MUCH CHANGE IN
SENSIBLE WEATHER ACROSS THE REGION WITH THIS PATTERN IN PLACE...WITH
CONTINUED DAILY CHANCES FOR SHOWERS AND STORMS THROUGH THE WEEKEND
AND INTO EARLY NEXT WEEK. THIS FEATURE LIFTS NORTHEAST TOWARD THE
CENTRAL HIGH PLAINS ON SUN AND MON WITH THE ECMWF STILL ADVERTISING
DEFORMATION PRECIP BANDING ON THE BACK SIDE. POTENTIAL EXISTS FOR A
FAIRLY WIDESPREAD MODERATE RAIN EVENT DURING THIS TIME...HOWEVER THE
GFS IS NOT AS BULLISH WITH QPF AMOUNTS. WILL NEED TO WATCH CLOSELY
AS THIS WILL CAUSE HYDRO ISSUES IF THIS PCPN FALLS OVER THE SNOW
PACKED MOUNTAINS. H7 TEMPS WILL BE AROUND 8 TO 10 DEG C THROUGH THE
MAJORITY OF THE FCST PERIOD...GIVING WAY TO HIGHS BETWEEN 65 AND 75
DEGREES FOR MUCH OF THE LOWER ELEVATIONS. WESTERLY DOWNSLOPE RETURNS
ON MON...GIVING WAY TO WARMER AND DRIER CONDITIONS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY AFTERNOON)
ISSUED AT 553 PM MDT TUE MAY 20 2014
CONVECTION TO CONTINUE THROUGH SUNSET THIS EVENING. WINDS
FAVORABLE OVERNIGHT FOR SOME UPSLOPING STRATUS TO DEVELOP HERE AT
KCYS AND POSSIBLY KLAR. WENT MVFR OF CEILINGS...BUT LATER SHIFTS
MAY NEED TO LOWER FURTHER.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MDT TUE MAY 20 2014
CONCERNS TO REMAIN LOW FOR THE REST OF THE WEEK WITH CONDITIONS
AND FUELS EXPECTED TO REMAIN NON-CRITICAL. SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS WILL MOVE ACROSS MAINLY EASTERN DISTRICTS
MOST DAYS WITH VERY GOOD CHANCES FOR WETTING RAINS. A MORE
WIDESPREAD RAIN EVENT SATURDAY AFTERNOON THROUGH MONDAY MORNING
SHOULD DEVELOP ACROSS SOUTHEAST WYOMING AND NEBRASKA
PANHANDLE...SO FIRE WEATHER CONCERNS ARE MINIMAL.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RUBIN
SHORT TERM...CLAYCOMB
LONG TERM...HAMMER
AVIATION...CLAYCOMB
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
245 AM MST FRI MAY 23 2014
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL CONTINUE TO MOVING EAST ACROSS THE DESERT
SOUTHWEST BRINGING A SLIGHT CHANCE OF THUNDERSTORMS TO THE AREA
TODAY. STORM CHANCES WILL BE LIMITED MAINLY TO THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON SATURDAY. ABOVE NORMAL TEMPERATURES WILL
RETURN TO THE REGION EARLY NEXT WEEK AS HIGH PRESSURE BECOMES
REESTABLISHED TO OUR SOUTH.
&&
.DISCUSSION...
LATEST WV IMAGERY SHOWS THE PERSISTENT CUTOFF LOW SPINNING ACROSS THE
DESERT SOUTHWEST. SHORT-TERM MODELS ARE IN GOOD AGREEMENT THAT THE
MID-TROPOSPHERIC LOW WILL CONTINUE DRIFTING EASTWARD INTO WESTERN AZ
TODAY. ALTHOUGH VORTICITY FORCED ASCENT REMAINS RELATIVELY STRONG
AND ORGANIZED ACROSS AZ...MOISTURE WILL BE A LIMITING FACTOR ACROSS
THE FORECAST AREA WITH THE DEEPEST MOISTURE CLEARLY LOCATED ALONG
THE EASTERN FLANK OF THE LOW AND EAST OF THE REGION.
NEVERTHELESS...A PERSISTENCE FORECAST ALONG WITH SUPPORT FROM THE
LOCAL WRFS AND HRRR SUGGEST THAT ISOLATED THUNDERSTORMS ARE POSSIBLE
TODAY IN THE VICINITY OF THE MID-LEVEL COLD POOL...MAINLY ACROSS THE
LOWER DESERTS OF SOUTHWESTERN AZ. ANY STORMS THAT DO DEVELOP WILL
NOT CONTAIN MUCH RAIN. INSTEAD THE GREATER THREAT REMAINS DRY
LIGHTNING ALONG WITH LOCALLY GUSTY WINDS AND LOCALIZED BLOWING DUST.
SUITE OF MODEL GUIDANCE INDICATES THAT THE UPPER LOW WILL CONTINUE
SLIDING EASTWARD THIS WEEKEND. HOWEVER...MODELS DIFFER ON THE
EVOLUTION OF SEVERAL SMALLER VORTICES EMBEDDED WITHIN THE LARGER
LOW. CONSEQUENTLY...DETERMINING THE EXACT THE PLACEMENT AND TIMING
OF PRECIPITATION WILL BE DIFFICULT...THOUGH THE CONSENSUS IS THAT
CONVECTION WILL LARGELY REMAIN CONFINED TO THE
CLIMATOLOGICALLY-FAVORED HIGHER TERRAIN NORTH AND EAST OF PHOENIX.
POPS ARE HIGHEST IN THESE AREAS...THOUGH ISOLATED THUNDERSTORMS IN
THE PHOENIX AREA CANNOT TOTALLY BE RULED OUT.
IN THE WAKE OF THE LOW EARLY NEXT WEEK...DRY SOUTHWESTERLY FLOW WILL
DEVELOP BETWEEN AN AREA OF LOW PRESSURE ACROSS THE PACIFIC NORTHWEST
AND A RIDGE ACROSS NORTHERN MEXICO. AFTER A PERIOD OF BELOW NORMAL
TEMPERATURES THROUGH SUNDAY...ABOVE NORMAL TEMPERATURES WILL RETURN
MONDAY AND WILL CONTINUE THROUGH NEXT WEEK. HOWEVER...LATEST
GUIDANCE INDICATES THAT TEMPERATURES WILL REMAIN WELL BELOW RECORDS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL... AND SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
UPPER LEVEL LOW WILL LINGER OVER THE REGION AND SLOWLY SHIFT EAST
ACROSS SE CALIFORNIA AND ARIZONA DURING THE PERIOD. WINDS EXPECTED
TO REMAIN LIGHT...GENERALLY AROUND 10KT THROUGH FRIDAY AFTERNOON.
THUNDERSTORMS SHOULD REMAIN CONFINED TO THE MOUNTAINS OF EASTERN AZ
OVERNIGHT...BUT NOT OUT OF THE QUESTION TO GET AN ISOLATED SHOWER IN
THE VICINITY OF TERMINALS BY 12Z FRIDAY. SUFFICIENT MOISTURE AND
INSTABILITY WILL KEEP SLIGHT CHANCE OF THUNDERSTORMS ACROSS THE
REGION DURING THE DAY FRIDAY AND INTO THE EVENING HOURS...THE
STRONGEST STORMS IF THEY FORM WILL HAVE THE POTENTIAL TO PRODUCE
OUTFLOW WIND GUSTS TO 40 KT...AND AREAS OF BLOWING DUST/REDUCED
VISIBILITY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
THE SLOW MOVING LOW PRESSURE SYSTEM WILL FINALLY MAKE AN EXIT FROM
THE REGION MOVING EASTWARD. ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE ACROSS NORTHEASTERN AZ THROUGH
SUNDAY...THOUGH RAIN CHANCES WILL BE CONSIDERABLY LESS ACROSS THE
LOWER DESERTS. ISOLATED DRY THUNDERSTORMS WILL ALSO REMAIN A THREAT
AS WELL...PARTICULARLY ACROSS THE HIGHER TERRAIN NORTH AND EAST OF
PHOENIX...AS THE AIR MASS WILL REMAIN VERY DRY WITH LOW HUMIDITY
VALUES. WINDS WILL GENERALLY REMAIN LIGHT...EXCEPT IN THE VICINITY
OF THUNDERSTORMS. A WARMING AND DRYING TREND IS EXPECTED WITH ABOVE
AVERAGE TEMPERATURES LIKELY BY MONDAY AND CONTINUING THROUGH MIDWEEK.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....MEYERS
FIRE WEATHER...DEWEY/HIRSCH
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
421 AM CDT FRI MAY 23 2014
...UPDATED LONG TERM DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI MAY 23 2014
ISENTROPIC LIFT WILL REDEVELOP LATER THIS MORNING IN A MOIST
ATMOSPHERE WITH PRECIPITABLE WATER VALUES IN EXCESS OF 1 INCH AS
FAR WEST AS EASTERN COLORADO. THIS SHOULD ALLOW SHOWER AND
THUNDERSTORMS TO DEVELOP EASILY WITH INCREASING LIFT. AS THE
THUNDERSTORMS HAVE DECAYED, WE`VE FOLLOWED THE HRRR TRENDS FOR
CONVECTION THROUGH AROUND 12-14 UTC, BEFORE SIGNIFICANTLY RAMPING UP
CHANCES TOWARD 18 UTC ONCE AGAIN. EXTENSIVE CLOUDS AND OCCASIONAL
PRECIPITATION ESPECIALLY BY THIS AFTERNOON WILL RELEGATE
TEMPERATURES HOMOGENEOUSLY IN THE 70S ACROSS MOST OF THE FORECAST
AREA. CAPE VALUES WILL BE NOT AS HIGH AS ON THURSDAY AND SEVERE
THREAT IS MINIMAL AS A RESULT. SHOWERS AND THUNDERSTORMS SHOULD
PERSIST INTO THE EVENING HOURS AND FORECAST PRECIPITATION CHANCES
WERE MAXIMIZED AROUND 0 UTC. AS A RESULT OF THE RELATIVELY HUMID
CONDITIONS, LOWS TONIGHT WILL LIKELY NOT FALL BELOW 60 DEGREES IN
MOST AREAS WITH FOG BECOMING POSSIBLE TOWARD EARLY MORNING
SATURDAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 418 AM CDT FRI MAY 23 2014
THE MEDIUM RANGE MODELS CONTINUE TO SHOW AN UPPER LEVEL LOW PRESSURE
SYSTEM MOVING SLOWLY FROM THE DESERT SOUTHWEST ON SATURDAY INTO THE
CENTRAL AND SOUTHERN HIGH PLAINS BY MEMORIAL DAY. AS THE UPPER LOW
APPROACHES THE REGION, LOW LEVEL SOUTHERLY FLOW WILL CONTINUE TO
PUMP GULF MOISTURE INTO THE CENTRAL HIGH PLAINS. WEAK DISTURBANCES
ROTATING AROUND THE UPPER LOW AND EJECTING OUT OVER THE CENTRAL
PLAINS WILL BRING THUNDERSTORM CHANCES TO WESTERN AND CENTRAL KANSAS
PRETTY MUCH EVERY DAY THROUGH TUESDAY. WIND FLOW WILL NOT BE OVERLY
STRONG OVER WESTERN KANSAS THE NEXT FEW DAYS BUT MODEL SOUNDINGS
SHOW SOME DIRECTIONAL SHEAR AND THERE SHOULD BE ENOUGH INSTABILITY
FOR AT LEAST A SMALL THREAT OF SEVERE WEATHER ON SATURDAY AFTERNOON
AND EVENING.
THE MODELS BEGIN TO DIVERGE A LITTLE ON HOW QUICKLY THE UPPER LOW
CONTINUES EAST OUT OF THE HIGH PLAINS TOWARD THE MIDDLE PART OF THE
WEEK BUT CONTINUE TO MOVE IT OUT WITH AN UPPER LEVEL RIDGE BUILDING
OVER THE HIGH PLAINS. THIS WILL ULTIMATELY RESULT IN DECREASING
CHANCES FOR THUNDERSTORMS ALONG WITH A WARMING TREND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 140 AM CDT FRI MAY 23 2014
REMNANTS OF A DECAYING MCS WILL AFFECT THE AREAL TERMINALS EARLY
THIS MORNING. MOST OF THE STRATIFORM PRECIPITATION SHOULD DIMINISH
BY AROUND 12 UTC. BY MID TO LATE MORNING, INCREASING ISENTROPIC LIFT
SHOULD DEVELOPING ASSOCIATED WITH AN APPROACHING WAVE, BRINGING
ADDITIONAL HIGH CHANCES FOR RAIN AN THUNDERSTORMS TO THE AREA
TERMINALS THROUGH THE DAY AND THIS EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 78 62 81 61 / 70 70 60 60
GCK 77 60 81 60 / 70 70 60 60
EHA 76 57 80 57 / 60 60 60 60
LBL 78 60 79 59 / 70 70 60 70
HYS 78 63 79 62 / 70 70 40 60
P28 80 64 80 64 / 70 70 50 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...GERARD
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
418 AM CDT Fri May 23 2014
...UPDATED LONG TERM DISCUSSION...
.SHORT TERM...(Today and tonight)
ISSUED AT 320 AM CDT FRI MAY 23 2014
Isentropic lift will redevelop later this morning in a moist
atmosphere with precipitable water values in excess of 1 inch as
far west as eastern Colorado. This should allow shower and
thunderstorms to develop easily with increasing lift. As the
thunderstorms have decayed, we`ve followed the HRRR trends for
convection through around 12-14 UTC, before significantly ramping up
chances toward 18 UTC once again. Extensive clouds and occasional
precipitation especially by this afternoon will relegate
temperatures homogeneously in the 70s across most of the forecast
area. Cape values will be not as high as on Thursday and severe
threat is minimal as a result. Showers and thunders toms should
persist into the evening hours and forecast precipitation chances
were maximized around 0 UTC. As a result of the relatively humid
conditions, lows tonight will likely not fall below 60 degrees in
most area with fog becoming possible toward early morning
Saturday.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 418 AM CDT FRI MAY 23 2014
The medium range models continue to show an upper level low pressure
system moving slowly from the Desert Southwest on Saturday into the
central and southern High Plains by Memorial Day. As the upper low
approaches the region, low level southerly flow will continue to
pump Gulf moisture into the central High Plains. Weak disturbances
rotating around the upper low and ejecting out over the central
Plains will bring thunderstorm chances to western and central Kansas
pretty much every day through Tuesday. Wind flow will not be overly
strong over western Kansas the next few days but model soundings
show some directional shear and there should be enough instability
for at least a small threat of severe weather on Saturday afternoon
and evening.
The models begin to diverge a little on how quickly the upper low
continues east out of the High Plains toward the middle part of the
week but continue to move it out with an upper level ridge building
over the High Plains. This will ultimately result in decreasing
chances for thunderstorms along with a warming trend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 140 AM CDT FRI MAY 23 2014
Remnants of a decaying MCS will affect the areal terminals early
this morning. Most of the stratiform precipitation should diminish
by around 12 UTC. By mid to late morning, increasing isentropic lift
should developing associated with an approaching wave, bringing
additional high chances for rain an thunderstorms to the area
terminals through the day and this evening.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 78 62 81 61 / 70 70 60 60
GCK 77 60 81 60 / 70 70 60 60
EHA 76 57 80 57 / 60 60 60 60
LBL 78 60 79 59 / 70 70 60 70
HYS 78 63 79 62 / 70 70 40 60
P28 80 64 80 64 / 70 70 50 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Gerard
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
322 AM CDT Fri May 23 2014
...SHORT TERM UPDATED...
.SYNOPSIS...
ISSUED AT 320 AM CDT FRI MAY 23 2014
A decaying MCS was still producing light to moderate rainfall from
Liberal to Garden city, Scott City and Syracuse as of 2 am. Strong
westerly surface outflow was weakening with time as well, as winds
near the Colorado line had readjusted to light and variable under
the leftover mesohigh. METAR totals and Dual-Pol storm total
accumulations indicated highest rainfall amount mainly from the
previous evening`s trailing stratiform ranged between 1 an under 2
inches southwest of a Liberal to Coolidge line.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 320 AM CDT FRI MAY 23 2014
Isentropic lift will redevelop later this morning in a moist
atmosphere with precipitable water values in excess of 1 inch as
far west as eastern Colorado. This should allow shower and
thunderstorms to develop easily with increasing lift. As the
thunderstorms have decayed, we`ve followed the HRRR trends for
convection through around 12-14 UTC, before significantly ramping up
chances toward 18 UTC once again. Extensive clouds and ocassional
precipitation especially by this afternoon will relegate
temperatures homogeneously in the 70s across most of the forecast
area. Cape values will be not as high as on Thursday and severe
threat is minimal as a result. Showers and thunderstoms should
persist into the evening hours and forecast precipitation chances
were maximized around 0 UTC. As a result of the relatively humid
conditions, lows tonight will likley not fall below 60 degrees in
most area with fog becoming possible toward early morning
Saturday.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 235 PM CDT THU MAY 22 2014
Medium range models indicate a southwest flow aloft prevailing
across the Western High Plains Saturday as a closed off upper level
low shifts slowly eastward across the Four Corners Region. As the
system approaches, increased divergence aloft downstream of the
trough axis will intensify across the high plains of eastern
Colorado, western Kansas, and the panhandle of Oklahoma, especially
into Saturday evening. Meanwhile, a prevailing low level
south-southeasterly flow will continue to draw additional moisture
into the state with H85 dewpoints nearing 15C. Although the flow
aloft is expected to remain generally weak, GFS/ECMWF model
soundings do show some marginal directional shear along with SBCAPE
values in excess of 1500 J/KG. As H5 vort maxima cycle northeast out
of the trough axis into the high plains, shower and thunderstorm
development is likely with some chance for marginally severe
weather possible. However, a bigger concern may be the potential
for brief periods of heavy rainfall with model soundings also
showing PW values well over one inch.
Similar conditions will exist Sunday as the closed off upper level
low moves across the Rockies into the Western High Plains. However,
a few more thunderstorms may be possible as an upper level jet noses
northward into southwest Kansas Sunday afternoon while a developing
dryline sharpens near the Colorado border. In addition, GFS/ECMWF
model soundings indicate an inverted V profile by Sunday afternoon
with SBCAPE values pushing above 2000 J/KG. Although speed shear
looks a little more favorable than Saturday, directional shear
does not which may limit the strength of any developing storms.
However, the potential for significant rainfall lingers with PW
values remaining fairly high with values near to a little above
one inch. Shower and thunderstorm potential shifts eastward more
into central Kansas Monday as the closed off low pushes further
east into western Kansas. Drier conditions are likely by Wednesday
as weak upper level ridging fills in across the Western High
Plains in wake of the departing upper level low.
Fairly mild temperatures are likely Saturday as a cooler air mass
remains locked in across the Western High Plains The GFS/ECMWF show
H85 temperatures changing little from Friday with the mid teens(C)
across central Kansas to the upper teens(C) out near the Colorado
border. Due to expected increased cloud cover and areas of precip,
look for highs up into the upper 70s(F) to near 80F. Similar
temperatures are likely into Monday before a gradual warming
trend begins by mid week as weak upper level ridging develops
across the Intermountain West.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 140 AM CDT FRI MAY 23 2014
Remnants of a decaying MCS will affect the areal terminals early
this morning. Most of the stratiform precipitation should diminish
by around 12 UTC. By mid to late morning, increasing isentropic lift
should developing associated with an approaching wave, bringing
additional high chances for rain an thunderstorms to the area
terminals through the day and this evening.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 78 62 81 61 / 70 70 60 60
GCK 77 60 81 60 / 70 70 60 60
EHA 76 57 80 57 / 60 60 60 60
LBL 78 60 79 59 / 70 70 60 70
HYS 78 63 79 62 / 70 70 40 60
P28 80 64 80 64 / 70 70 50 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Russell
SHORT TERM...Russell
LONG TERM...JJohnson
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
142 AM CDT Fri May 23 2014
...UPDATED AVIATION SECTION...
.SHORT TERM...(This evening through Friday)
ISSUED AT 346 PM CDT THU MAY 22 2014
Tonight:
Main concern is dealing with orographic convection to the west. Afternoon
radar mosaic shows considerable thunderstorm activity across Colorado
and New Mexico. MCS propagation vectors support the eastward translation
of this activity and will eventually reach far SW Kansas by evening.
The HRRR is insistent in generating an MCS with a cold pool. This model
does seem to be - at times- too aggressive with cold pool generation.
Still, enough isentropic lift and moisture advection supports ramping
up the pops this evening. Think the main concern is heavy rainfall as
the 12Z KDDC raob PWAT is between the 75th percentile and the +2SD mark.
This is statistically significant. Bulk shear is far from reaching supercell
archetype. Secondary threat to heavy rainfall is outflow winds, which
could impact far western Kansas along and west of Highway 83. The boundary
layer will become more stable this evening, so that could mitigate any
momentum transfer issues. In addition to convection, have increased
QPF more in line with WPC guidance. Most of the mesoscale models (HRRR/WRF/4
km NAM) all suggest that a good chunk of the region might see 0.50-1.00"
from tonights and tomorrow thunderstorm activity.
Tomorrow:
Have ramped up pops again by afternoon and evening as PWAT remains near
an 1.00" and isentropic lift/warm air advection continues through the
day. Moist adiabatic thermodynamic skew-t/log-p`s and also slow MCS
propagation vectors suggest that heavy rainfall is still a threat for
tomorrow. Highest pops will be during the afternoon to 00Z as diurnally
induced instability increases. Again, would not be surprised to see
decent rainfall amounts through 7 pm tomorrow night, as alluded to
above.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 235 PM CDT THU MAY 22 2014
Medium range models indicate a southwest flow aloft prevailing
across the Western High Plains Saturday as a closed off upper level
low shifts slowly eastward across the Four Corners Region. As the
system approaches, increased divergence aloft downstream of the
trough axis will intensify across the high plains of eastern
Colorado, western Kansas, and the panhandle of Oklahoma, especially
into Saturday evening. Meanwhile, a prevailing low level
south-southeasterly flow will continue to draw additional moisture
into the state with H85 dewpoints nearing 15C. Although the flow
aloft is expected to remain generally weak, GFS/ECMWF model
soundings do show some marginal directional shear along with SBCAPE
values in excess of 1500 J/KG. As H5 vort maxima cycle northeast out
of the trough axis into the high plains, shower and thunderstorm
development is likely with some chance for marginally severe
weather possible. However, a bigger concern may be the potential
for brief periods of heavy rainfall with model soundings also
showing PW values well over one inch.
Similar conditions will exist Sunday as the closed off upper level
low moves across the Rockies into the Western High Plains. However,
a few more thunderstorms may be possible as an upper level jet noses
northward into southwest Kansas Sunday afternoon while a developing
dryline sharpens near the Colorado border. In addition, GFS/ECMWF
model soundings indicate an inverted V profile by Sunday afternoon
with SBCAPE values pushing above 2000 J/KG. Although speed shear
looks a little more favorable than Saturday, directional shear
does not which may limit the strength of any developing storms.
However, the potential for significant rainfall lingers with PW
values remaining fairly high with values near to a little above
one inch. Shower and thunderstorm potential shifts eastward more
into central Kansas Monday as the closed off low pushes further
east into western Kansas. Drier conditions are likely by Wednesday
as weak upper level ridging fills in across the Western High
Plains in wake of the departing upper level low.
Fairly mild temperatures are likely Saturday as a cooler air mass
remains locked in across the Western High Plains The GFS/ECMWF show
H85 temperatures changing little from Friday with the mid teens(C)
across central Kansas to the upper teens(C) out near the Colorado
border. Due to expected increased cloud cover and areas of precip,
look for highs up into the upper 70s(F) to near 80F. Similar
temperatures are likely into Monday before a gradual warming
trend begins by mid week as weak upper level ridging develops
across the Intermountain West.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 140 AM CDT FRI MAY 23 2014
Remnants of a decaying MCS will affect the areal terminals early
this morning. Most of the stratiform precipitation should diminish
by around 12 UTC. By mid to late morning, increasing isentropic lift
should developing associated with an approaching wave, bringing
additional high chances for rain an thunderstorms to the area
terminals through the day and this evening.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 78 62 80 61 / 70 70 60 60
GCK 77 60 81 60 / 70 70 60 60
EHA 76 57 80 57 / 60 60 60 60
LBL 78 60 81 59 / 70 70 60 70
HYS 78 63 80 62 / 70 70 50 60
P28 80 64 82 64 / 70 70 60 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...Sugden
LONG TERM...JJohnson
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS WICHITA KS
1151 PM CDT THU MAY 22 2014
...UPDATED FOR 06Z AVIATION DISCUSSION...
.UPDATE...
ISSUED AT 641 PM CDT THU MAY 22 2014
OVERALL...INTENSITY OF THE CONVECTION CONTINUES TO DECREASE AS
DIURNAL HEATING IS LOST FOR THE DAY. THE 21Z HRRR SHOWS AN AREA OF
STORMS THAT EXPANDS OVER THE HIGH PLAINS OVERNIGHT. ACCORDING TO
THE MODEL...THIS CAUSES OUTFLOW TO MOVE EAST AND PRODUCES
CONVECTION ACROSS THE FORECAST AREA AFTER 09Z.
GIVEN THERE ARE SO MANY BOUNDARIES LAYING AROUND AND THAT WE ARE
IN A WEAK FLOW SITUATION...CONFIDENCE IN ANY SUCH SOLUTION IS VERY
LOW. AT THIS TIME...THERE IS NO REASON TO DEVIATE FROM CURRENT
FORECAST.
COOK
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 325 PM CDT THU MAY 22 2014
LATE AFTERNOON/EARLY THIS EVENING
PERSISTENT CONVECTION FROM EARLIER THIS MORNING WENT UPSCALE
ALONG THE ASSOCIATED OUTFLOW ACROSS THE FLINT HILLS EARLY THIS
AFTERNOON. INTERSECTION OF STORM ON MESOSCALE OUTFLOW AND THE
SYNOPTIC STATIONARY FRONT APPARENTLY PRODUCED BRIEF ROPE TORNADO
EAST OF ROSALIA NEAR GREENWOOD/BUTLER COUNTY LINE. SPC MESO
DATA SHOWED MLCAPE OF 1500-2000 J/KG WITH SOME LOW LEVEL CAPE
AIDING INITIAL UPDRAFTS. THIS CONVECTION WAS ASSOCIATED WITH
RESIDUAL WEAK MESO VORT AND SHOULD CONTINUE TO FOSTER STORMS
IN THE WARM/UNSTABLE AIRMASS INTO THE EARLY EVENING ACROSS
SOUTHEAST KANSAS AND THE FLINT HILLS.
LATER TONIGHT THROUGH SUNDAY
ADDITIONAL CONVECTION IS EXPECTED ACROSS THE HIGH PLAINS WHICH
MAY SUPPORT A COUPLE COMPLEX OF STORMS OVERNIGHT. WEAK STEERING
FLOW WILL MAKE IT A BIT DIFFICULT TO PORTEND WHERE CONVECTION
MAY IMPACT THE FORECAST AREA. HOWEVER WILL SHOW A GENERAL
UP-TWEAK WITH MODEST POPS OVERNIGHT ACROSS THE ENTIRE AREA.
THE SHORT TERM MODELS ARE SOMEWHAT MORE IN AGREEMENT WITH A
SIGNAL FOR ORGANIZED CONVECTION TO AFFECT MUCH OF THE AREA
LATE FRIDAY INTO EARLY SATURDAY...AND WILL SHOW RELATIVELY
HIGHER POPS IN THESE TIME PERIODS. OTHERWISE...WITH LITTLE OR
NO CAPPING THROUGH SATURDAY...CHANCES FOR CONVECTION WILL REMAIN
IN THE FORECAST ALONG THE QUASI-STATIONARY FRONT. THIS FRONT
WILL WEAKEN AS IT SHIFTS NORTH DURING SUNDAY WITH INCREASING
SOUTHERLY FLOW ACROSS THE AREA. FOCUS FOR MORE ORGANIZED
CONVECTION SHOULD BE SITUATED ACROSS WESTERN KANSAS DURING THE
AFTERNOON., HOWEVER AS A SHORTWAVE EJECTS OUT ACROSS THE AREA
INTO SUNDAY NIGHT...BETTER CHANCES FOR CONVECTION SHOULD
AGAIN TRANSLATE EAST ACROSS MUCH OF THE AREA.
TEMPERATURES WILL REMAIN A LITTLE BIT ABOVE SEASONAL CLIMO
THOUGH NOT NEARLY AS HOT AS RECENT DAYS.
DARMOFAL
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 325 PM CDT THU MAY 22 2014
THE MAIN CHALLENGE IS THE HANDLING OF THE REMNANT CLOSED
UPPER LOW ACROSS THE PLAINS THROUGH EARLY NEXT WEEK. THE
ECMWF HOLDS ON TO THIS A BIT LONGER WHICH WOULD LINGER
PRECIP/CONVECTIVE CHANCES ACROSS SOUTHEAST KANSAS. FOR NOW
WILL MAKE LITTLE CHANGE TO THE GOING FORECAST.
KED
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1139 PM CDT THU MAY 22 2014
SPORADIC CONVECTION CONTINUES ACROSS EASTERN KANSAS. AN AREA OF
THUNDERSTORMS HAS CONFINED ITSELF AROUND KICT SINCE ABOUT 0430Z.
THIS LOOKS TO PERSIST THROUGH 08Z AS A BEST ESTIMATE. AS HAS BEEN
STATED BEFORE...THESE SO CALLED AIRMASS THUNDERSTORMS ARE VERY
UNPREDICTABLE AT BEST.
CONDITIONS ARE AGAIN FAVORABLE FOR THUNDERSTORMS FRIDAY AFTERNOON
AND EVENING ACROSS MUCH OF THE AREA. TIMING LOOKS BEST DURING
AFTERNOON HEATING...FROM AROUND 19Z ON THE 23RD THROUGH ABOUT 04Z
ON THE 24TH. OUTSIDE OF THE STORMS...CONDITIONS WILL BE VFR.
COOK
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 66 82 65 81 / 40 50 60 50
HUTCHINSON 64 80 64 81 / 50 50 60 50
NEWTON 64 80 64 80 / 40 50 60 60
ELDORADO 64 80 64 80 / 40 50 60 60
WINFIELD-KWLD 66 83 65 82 / 40 50 50 50
RUSSELL 62 78 62 81 / 40 40 60 50
GREAT BEND 63 78 63 80 / 50 40 60 50
SALINA 63 80 64 81 / 40 40 60 50
MCPHERSON 64 80 64 80 / 40 50 60 50
COFFEYVILLE 67 83 66 83 / 60 40 40 50
CHANUTE 65 81 65 81 / 50 40 40 50
IOLA 64 80 65 80 / 50 40 40 60
PARSONS-KPPF 66 83 65 82 / 70 40 40 50
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1046 PM MDT THU MAY 22 2014
.UPDATE...
ISSUED AT 923 PM MDT THU MAY 22 2014
UPDATED GRIDS AND ZONES FOR THE CANCELLATION OF SEVERE
THUNDERSTORM WATCH 177. LATEST HRRR AND RADAR TRENDS INDICATE A
RELATIVELY SLOW MOVING AREA OF RAIN OVER EASTERN COLORADO AND
NORTHWEST KANSAS. FOR THIS REASON LOWERED POPS TO HIGH CHANCE IN
THE EASTERN FA FOR OVERNIGHT. ALSO INCLUDED PATCHY FOG FOR THE
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 148 PM MDT THU MAY 22 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS LARGE CLOSED UPPER OVER
SOUTHERN CALIFORNIA WITH RIDGE ACROSS PLAINS AND SOUTHEASTERN US.
SOUTHERLY/DIFLUENT FLOW IS IN PLACE ACROSS THE SOUTHERN PLAINS AND
ROCKIES WITH MOIST PLUME EXTENDING FROM PACIFIC NORTH WITHIN THIS
FLOW. AT THE SURFACE A STALLED FRONT IS ANALYZED ACROSS SOUTHERN KS
AND ACROSS OK/TX PANHANDLES. UPSTREAM RADARS SHOW THUNDERSTORM
ACTIVITY ALREADY DEVELOPING ACROSS NORTHEAST NEW MEXICO AND ALONG
THE FRONT RANG WITH A NORTHERLY PROGRESSION.
UPPER LEVEL ENERGY ROTATING THROUGH THE UPPER FLOW ON THE EASTERN
EDGE OF THE UPPER TROUGH WE WILL CONTINUE TO SUPPORT
SHOWER/THUNDERSTORM DEVELOPMENT. ANOMALOUSLY MOIST AIR MASS (PWATS
TWO STANDARD DEVIATIONS ABOVE NORMAL) WILL LINGER TONIGHT THROUGH
TOMORROW.
FOR TONIGHT...THUNDERSTORMS ARE DEVELOPING IN PROXIMITY TO LARGE
SCALE DIFLUENT FLOW OVER NEW MEXICO AND CENTRAL COLORADO. TD VALUES
AROUND 60F HAS LEAD TO SBCAPE 1500-2000 J/KG. GUIDANCE SHOWS MUCAPE
THROUGH FRIDAY AROUND 2000 J/KG OVER OUR CWA. GUIDANCE SUPPORTS
THUNDERSTORM ACTIVITY UPSTREAM FROM OUR CWA MERGING INTO
CLUSTER/THUNDERSTORM COMPLEX AND SPREADING NORTH INTO OUR CWA. WITH
ELEVATED FRONTAL ZONE GENERALLY LINGERING NEAR THE I-70 CORRIDOR AND
MOISTURE POOLING/INSTABILITY LINGERING WE SHOULD SEE A GOOD PATTERN
FOR THIS ACTIVITY INCREASING IN COVERAGE. 0-6KM WIND IS 15KT OR
LESS...HOWEVER WIND PROFILES BELOW 800MB ARE VERY WEAK ALONG FRONTAL
ZONE OUT OF THE EAST...WHILE 400-250MB WINDS ARE STRAIGHT OUT OF THE
WEST. IN ADDITION TO THE ALREADY WET SIGNAL THIS PATTERN SUPPORTS
BACK BUILDING OF THUNDERSTORMS ALONG FRONTAL ZONE AND VERY SLOW
PROPAGATION OF THUNDERSTORMS. CONFIDENCE IS INCREASING IN AT LEAST A
LOCALIZED FLOODING THREAT TONIGHT...BUT I AM NOT SURE HOW WIDESPREAD
THIS WILL BE SO I AM HOLDING OFF ON ISSUANCE OF FLASH FLOOD WATCH.
SHEER PROFILES ARE NOT THAT IMPRESSIVE...HOWEVER WITH MODERATE
INSTABILITY/GOOD MID LEVEL LAPSE RATES...DAMAGING WINDS ASSOCIATED
WITH COLD POOL DRIVEN THUNDERSTORM COMPLEXES OR STRONG WIND/LARGE
HAIL WITH PULSE TYPE CONVECTION CANT BE RULED OUT.
GUIDANCE SHOWS GOOD 850MB SUPPORT LINGERING OVERNIGHT AND MODELS
CONTINUE TO LINGER SHOWERS/THUNDERSTORMS THROUGH TOMORROW
AFTERNOON...WITH AN ENHANCEMENT IN ACTIVITY AS SURFACE FRONT STALLS
ALONG KS/NE STATE LINE. I WAS COMFORTABLE LINGERING POPS ACROSS THE
CWA THROUGH THE SHORT TERM PERIOD...THOUGH I DID TRY TO TIME OUT THE
PERIODS BETWEEN WEAK SHORTWAVES FOR POSSIBLE LULLS IN COVERAGE. I
ALSO BUMPED UP QPF TO REFLECT PERIODS OF MODERATE-HEAVY PRECIP
POTENTIAL. THERE IS ALSO SOME POTENTIAL FOR FOG DEVELOPMENT LATE
TONIGHT/EARLY FRIDAY...HOWEVER SURFACE PATTERN COULD BE CHAOTIC IF
THUNDERSTORM ACTIVITY IS ONGOING...AND DECIDED NOT TO INCLUDE
MENTION WITH THIS UPDATE. TEMPS TONIGHT AND FRIDAY ARE TRICKY AS
MODELS WOULD SUPPORT SHOWERS/THUNDERSTORMS ACROSS THE REGION THROUGH
THESE PERIODS...AND FRONTAL POSITION IS STILL UNCERTAIN.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 328 PM MDT THU MAY 22 2014
MAIN FORECAST CONCERNS HOW LONG WILL UPCOMING WET PERIOD LAST AND
HOW MUCH WE WILL GET DURING THIS TIME WHICH LEAD TO HYDRO ISSUES.
SATELLITE SHOWING AN AMPLIFIED PATTERN FROM THE PACIFIC INTO NORTH
AMERICA. FOR OUR AREA SITUATION FOR THE FORESEEABLE FUTURE WILL BE
CONTROLLED BY SPEED AND LOCATION OF UPPER LOW NOW CUTTING OVER THE
SOUTHWEST PORTION OF THE COUNTRY. FLOW BEHIND THIS SYSTEM ALONG
WITH STRONGER JET WINDS AND HEIGHT FALLS TO ITS SOUTH SHOWING SLOW
MOVEMENT AND A FURTHER SOUTH MOVEMENT WILL CONTINUE. STATIONARY
FRONT CONTINUES TO BE TO OUR SOUTH AND WEST WITH THE SOUTHERN
POSITION ROUGHLY ALONG THE KANSAS BORDER.
AT JET LEVEL...MODELS APPEARED TO DO FINE. AT MID LEVELS...THE
MODELS TENDED TO BE TOO FAR SOUTH AND EAST WITH THE SOUTHWEST UPPER
LOW. HERE AND OVERALL THE UKMET WAS DOING A LITTLE BETTER THAN THE
GFS AND CANADIAN. THE NAM WAS DOING A LITTLE BETTER THAN THE ECMWF
ON THE SURFACE WIND AND PRESSURE FIELD. THE GFS WAS DOING A LITTLE
BETTER THAN THE CANADIAN AND SREF ON THE LOW LEVEL THERMAL FIELD.
FRIDAY NIGHT...CONTINUATION OF WHAT IS STARTING DURING THE DAY.
LARGE AREA OF THUNDERSTORMS/HEAVY RAINFALL MOVES ACROSS THE AREA
FROM SOUTHWEST TO NORTHEAST. IT LOOKS LIKE THERE SHOULD BE A LULL IN
THE PRECIPITATION TOWARD THE END OF THE NIGHT. AT THAT TIME...MODELS
ARE SHOWING A NEARLY SATURATED BOUNDARY LAYER AIR MASS. IF NO
RAINFALL IS OCCURRING THERE LOOKS LIKE THERE WILL BE A GOOD CHANCE
OF AREAS OF FOG DEVELOPING.
SATURDAY/SATURDAY NIGHT...AFTER OVERNIGHT SHORTWAVE TROUGH MOVES
THROUGH THE MID LEVELS DRY OUT AND SHOULD HAVE A BRIEF TIME PERIOD
WHERE LITTLE TO NO PRECIPITATION SHOULD BE OCCURRING. AREAS OF FOG
SHOULD CONTINUE THROUGH THE MORNING. MODELS ARE IN GENERAL
AGREEMENT OF HAVING THE UPPER LOW NEAR THE ARIZONA/NEW MEXICO
BORDER BY LATE IN THE AFTERNOON. ANOTHER SHORTWAVE ROTATES IN FROM
THE SOUTH AS DIFLUENT FLOW ALOFT MOVES OVER THE AREA. MODELS ARE
TRYING TO DRY OUT THE AIR MASS WITH THIS FLOW IN PLACE AND AM NOT
BUYING THIS RIGHT NOW. SHOULD BE ANOTHER ROUND OF THUNDERSTORMS
WITH MODERATE TO HEAVY RAINFALL.
SUNDAY...SOME DIFFERENCE ON POSITION OF THE UPPER LOW IS SHOWN BY
THE ENSEMBLES AND DETERMINISTIC MODELS WHICH AFFECTS MANY THINGS BUT
UPPER JET LOOKS TO BE NEAR OR OVER THE WESTERN HALF OF THE AREA.
AREA IS STILL IN SOUTHERLY FLOW ALOFT WITH LOW LEVEL ALSO
CONTINUING TO BRING IN MOISTURE. A SHORTWAVE ROTATES THROUGH THIS
WHILE A UPPER JET AXIS ESTABLISHES ITSELF OVER THE WESTERN HALF OF
THE AREA. ONCE AGAIN MODELS ARE SHOWING THE AIR MASS DRYING AND AM
NOT SURE ABOUT THAT. THERE SHOULD BE A CONTINUED CHANCE OF
THUNDERSTORMS.
SUNDAY NIGHT THROUGH THURSDAY...MODEL HANDLING OF UPPER LOW BY
ENSEMBLES AND DETERMINISTIC OUTPUT ARE SHOWING DIFFERENCES. ALTHOUGH
THERE IS A GENERAL TENDENCY OF SLOWING THE LOW OR KEEPING IT NEARLY
STATIONARY SUNDAY NIGHT INTO MONDAY WITH A BETTER AGREEMENT IN
HAVING THE CIRCULATION FURTHER SOUTH. MODELS ACTUALLY TAKE THIS
SYSTEM THROUGH MONDAY INTO MONDAY NIGHT IN A FAVORABLE POSITION TO
BE IN WRAP AROUND/MID LEVEL DEFORMATION ZONE. ALL THESE DIFFERENCES
NOT SURPRISING WITH THIS SINCE MODELS USUALLY DO HAVE A PROBLEM WITH
THESE KIND OF SYSTEMS AND THIS IS RATHER UNUSUAL FOR THIS TIME OF
YEAR.
THE CRH_INIT GAVE ME CHANCE POPS SUNDAY NIGHT INTO MONDAY WITH
SLIGHT CHANCES GIVEN MONDAY NIGHT. AM CONCERNED THAT THIS PERIOD
COULD END UP BEING WETTER...ESPECIALLY MONDAY AND MONDAY NIGHT. AM
CONTENT RIGHT NOW IN LEAVING THIS AS IS SINCE THERE ARE HIGH CHANCE
POPS IN THERE. WITH THAT MONDAY HIGH TEMPERATURES COULD BE COOLER
AND OVERALL MAY NOT BE THE MOST PLEASANT MEMORIAL DAY. BY THE TIME
MONDAY ENDS...A SUBSTANTIAL AMOUNT OF PRECIPITATION SINCE TODAY
COULD HAVE OCCURRED AND MAY BE EXPERIENCING HYDRO PROBLEMS THROUGH
MOST OF THIS PERIOD.
ON TUESDAY...MODELS STILL NOT SHOWING THE SYSTEM NOT TOO FAR TO THE
EAST AND SOUTH AT THE BEGINNING OF THE DAY. THIS DAY COULD DEFINITELY
BE COOLER AND WETTER AS WELL BUT EVERYONE IS CONTENT IN LEAVING AS IS
AND DO NOT BLAME THEM WITH THE MODEL DIFFERENCES. THERE IS SOME
MOVEMENT TO THE SOUTH AND EAST THROUGH TUESDAY NIGHT.
PROBABLY THE MOST UNCERTAIN TIME PERIOD IS WEDNESDAY INTO THURSDAY.
THE ECMWF AND GFS MOVE THE SYSTEM ABOUT THE SAME AMOUNT TO THE
EAST. HOWEVER...THE GFS IS FURTHER SOUTH. THE GFS HAS MORE RIDGING
OVER OUR AREA THAN THE ECMWF. THE ECMWF EVEN STARTS TO RETROGRADE
THE SYSTEM A LITTLE DURING THIS TIME PERIOD. THE AIR MASS STILL LOOKS
MOIST ENOUGH TO SUPPORT CONVECTION WITH SOME SHORTWAVE TROUGHS MOVING
THROUGH WITH THE ECMWF LOOKING A LITTLE MORE FAVORABLE. CRH_INIT
DOES HAVE SOME LOW CHANCE POPS IN THERE FROM LATE WEDNESDAY INTO
THURSDAY. THIS MAY BE A BIT WET BUT THIS IS CONVECTIVE SEASON AND
THESE POPS ACTUALLY FIT CLIMATOLOGY. SO NOT ONLY DID I NOT CHANGE
ANY OF THE POPS BUT OVERALL CHANGED NOTHING ELSE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1037 PM MDT THU MAY 22 2014
SHOWERS AND THUNDERSTORMS WILL BE LIKELY AT KGLD OVERNIGHT WITH
ONLY A CHANCE AT KMCK. FORECAST SOUNDINGS INDICATE STRATUS AND FOG
WITH SOME MVFR CONDITIONS AND POSSIBLY IFR CONDITIONS WILL DEVELOP
AT KGLD AND KMCK OVERNIGHT. CONDITIONS SHOULD IMPROVE TO VFR BY MID
MORNING. TIMING OF THUNDERSTORMS IS RATHER UNCERTAIN FOR FRIDAY
BUT EXPECT THEM TO IMPACT BOTH SITES IN THE AFTERNOON AND EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...FS
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...FS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1146 PM CDT Thu May 22 2014
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Friday)
Issued at 350 PM CDT THU MAY 22 2014
A broad closed upper low was located across southern CA this
afternoon. A minor H5 shortwave trough was lifting northeast across
south central KS and was providing enough ascent for an area of
showers and thunderstorms across east central and central KS.
At the surface an outflow boundary extended from near Fort Scott,
KS, then extended west-northwest to near Cassoday before extending
southwest, east of ICT into northwest OK. The 19Z SPC mesoscale
EMC RUC showed 1500 ML CAPE along and south of the OFB across south
central and southeast KS. The instability decreases across east
central and northeast KS, with MLCAPES less than 500 J/KG along and
north of I-70. The greatest chance for stronger storms this
afternoon and early evening will be along and south of I-35, where
the stronger thunderstorms may produce pea to penny size hail and
wind gusts of 40 to 50 MPH. Across the remainder of east central KS
the greatest hazard will be brief heavy rainfall.
Tonight, once the minor H5 trough lifts northeast into northern MO,
the thunderstorms will push east of the CWA. Thunderstorms
developing across eastern CO late this afternoon will congeal into
one or two complexes of thunderstorms and track east and southeast
across western KS during the evening hours and may move into north
central KS after midnight, then across portions of east central KS
through the early morning hours of Friday. At this time the best
rain chances late tonight will be along and south of a Concordia, to
Manhattan, to Ottawa line, but this will be more of mesoscale
forecast and will depend on where the thunderstorms complexes
develop and how they will track during the evening hours. The
primary hazards from the thunderstorms later tonight will be pea to
penny size hail with locally heavy rainfall.
Friday...after the morning complex of thunderstorms weakens and
shifts east of the CWA, additional thunderstorms will redevelop
along the leftover outflow boundaries during the afternoon hours.
The effective shear looks to be rather weak, so any thunderstorms
that develop across northeast KS Tuesday afternoon should be pulse
storms with the primary hazard being small hail, gusty winds and
brief heavy rainfall. The best chances for thunderstorms Friday
afternoon will occur across the western and southern counties,
closer to the surface outflow boundary/front. Highs on Friday will
be in the mid to upper 70s.
.LONG TERM...(Friday Night through Thursday)
Issued at 350 PM CDT THU MAY 22 2014
The extended forecast will be noted with several chances for showers
and thunderstorms as a very slow-moving system moves through the
region.
By Friday night, models are in very good agreement in having a
closed-off low anchored over the southwestern U.S. and slowly
progress east-northeastward toward the region through the weekend.
As a result, southwesterly flow aloft will prevail with ample
moisture surging into the area. There looks to be a decent chance
for showers and thunderstorms Friday night into Saturday evening as models
suggest a shortwave developing along the lee side of the mid-level
trough and tracking into the area. While models suggest MUCAPE
values could be upwards of 1000-1500 J/kg, 0-6km bulk shear values
continue to look extremely low at less than 20kts. As a result, the
probability of severe weather still looks to be very low, however
cannot completely rule out the slight chance for small hail or some
stronger winds from any stronger storms that develop. The main
concern with this activity will be for heavy rainfall as soundings
show a very deep moist adiabatic profile with PWAT values upwards of
1.50 to 1.75 inches. If these rounds of showers and thunderstorms
end up tracking over the same areas, then we could see some
localized flash flooding.
By the latter part of the weekend into next week, the models
certainly begin to struggle in handling the details of this
approaching system. With that in mind, some models are suggesting
that the region may be between shortwaves Sunday and Sunday night,
so precipitation chances are lower during this period with any
activity likely being more scattered in nature. On Monday, the
mid-level low should be progressing towards western Kansas and the
Texas/Oklahoma panhandles. There looks to be a decent chance for
showers and thunderstorms on Monday as another shortwave tracks near
the area. Beyond Monday, as previously mentioned, the models
struggle with the tracking and timing of any additional shortwaves
as the mid-level low finally tracks over or just south of the area
Tuesday night through Wednesday. Additionally, there are very
notable differences in the tracking of the center of this low, as
the ECMWF keeps it just south of the forecast area with the GFS
having it dive much further south. Due to the large model
uncertainty, made only minor adjustments to the consensus forecast
with slight to low-end chance PoPs in place Monday night through
Wednesday night. The potential for severe storms next week continues
to be low.
Between the prolonged period of cloud cover and not much in the way
of temperature advection, expect temperatures to remain fairly
steady through the period with highs generally in the mid 70s to low
80s and lows in the 60s.
&&
.AVIATION...(For the 06Z TAFs through 06Z Friday Night)
Issued at 1139 PM CDT THU MAY 22 2014
Isolated showers with occasional thunder are beginning to
develop near the taf site. Expect this to continue for the next
few hours. Not confident how long the showers will last until the
early to mid morning hours. Do expect that the activity will fully
dissipate mid to late morning, although additional showers and
thunderstorms are possible late in the taf period.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...Hennecke
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS JACKSON KY
359 AM EDT FRI MAY 23 2014
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 258 AM EDT FRI MAY 23 2014
THE ARE TWO THINGS GOING ON THIS MORNING. THE FIRST IS THE IS AREAS
OF DENSE VALLEY FOG AROUND THE AREA...ESPECIALLY SOUTH OF THE HAL
ROGERS PARKWAY. THE NEXT IS THE RADAR IS SHOWING SOME WEAK RETURNS
TRYING TO MOVING INTO THE BLUEGRASS REGION IN THE NEXT FEW HOURS AND
ALSO SOME STRONGER ECHOES OVER WESTERN KENTUCKY AND CENTRAL
TENNESSEE. OTHER THAN THE HRRR...NONE OF THE MODELS ARE HANDLING
THESE ISOLATED TO SCATTERED SHOWERS. THE HRRR WAS SHOWING THESE
SHOWERS WILL BE DYING AS THEY TRY TO ENTER EASTERN KENTUCKY THIS
MORNING. WILL BE GOING WITH THE HRRR...SINCE IT IS THE ONLY MODEL
WITH A CLUE RIGHT NOW. A WEAK COLD FRONT IS LYING ALONG THE
TENNESSEE AND KY BORDER. THIS FRONT IS FORECAST TO MOVE SLOWING
SOUTH WITH TIME AS HIGH PRESSURE BUILDS INTO THE AREA. EXPECT THE FOG
TO BE BURNING OFF BETWEEN 8 AND 9 AM THIS MORNING. THERE MAY BE SOME
DEBRIS CLOUDS MOVING INTO THE AREA THIS MORNING AND THEN DECREASING
CLOUDS THIS AFTERNOON AS THE FRONT PUSHES FURTHER TO THE SOUTH. THE
CONSENSUS BLEND LOOKED PRETTY GOOD AND THEN NUDGED IT TOWARD THE GFS
MOS FOR THE HIGHS TODAY AND TOMORROW.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 359 AM EDT FRI MAY 23 2014
THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH AN
OVERALL SLOWED PATTERN AS A SHORTWAVE EXITS THE EAST COAST. A
MASSIVE RIDGE TAKES SHAPE OVER THE CENTRAL CONUS WITH THE JET STREAM
DISPLACED TO THE NORTH ALONG THE CANADIAN BORDER WITH NUMEROUS WAVES
TRACKING ALONG IT. MEANWHILE...AN UPPER CLOSED LOW SLIPS UNDERNEATH
THE RIDGE AND MOVES EAST INTO THE CENTRAL PLAINS BY MONDAY. BY
MONDAY NIGHT...A STRONGER SHORTWAVE DIVES SOUTH OVER THE EASTERN
GREAT LAKES AND INTO THE THE MID ATLANTIC STATES. BY MID WEEK...THE
PATTERN COMPLETELY STALLS WITH THE UPPER LOW OVER THE MID MS RIVER
VALLEY AND THE TROUGH OVER THE NEW ENGLAND STATES REMAINING. THE
PROMISING DETAIL HERE IS THAT BOTH THE GFS AND EURO AGREE ON
THIS...ONLY WITH MINOR DIFFERENCES. HOWEVER...THIS BEING A BLOCKING
PATTERN...THE MODELS MAY NOT HANDLE THE SET UP VERY WELL.
WITH THE UPPER LOW DRIFTING EAST ON TUESDAY AND THE FRONT ASSOCIATED
WITH THE WAVE OVER THE GREAT LAKES PUSHING SOUTH...THIS WILL SET THE
STAGE FOR SOME SHOWER AND THUNDERSTORM ACTIVITY FOR MONDAY THROUGH
THURSDAY. THIS ACTIVITY WILL ALSO LIKELY HAVE SOME DIURNAL
CHARACTERISTICS TO IT. AS WELL...DUE TO THE UNCERTAIN NATURE OF THIS
PATTERN...DID NOT GO ABOVE CHANCE POPS...ESPECIALLY FOR MONDAY AND
TUESDAY...WITH THAT UPPER LEVEL SUPPORT BARELY MAKING IT INTO THE
AREA. WITH THAT SAID...PLENTY OF WARMTH IN THIS PATTERN...DAYTIME
MAX HIGHS GETTING INTO THE 80S JUST ABOUT EVERYDAY OF THE EXTENDED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 135 AM EDT FRI MAY 23 2014
THERE IS SUFFICIENT LOW LEVEL MOISTURE IN THE VALLEYS TO PRODUCE FOG.
THE FOG SOUTH OF THE HAL ROGERS PARKWAY MAY BE DENSE PRODUCING
VISIBILITIES LESS THAN ON QUARTER MILE IN PLACES. SME AND LOZ WILL
LIKELY SEE SOME IFR FOG THIS MORNING THAT WILL BE BURNING OFF BETWEEN
13-14Z. JKL AND SJS MAY SEE SOME FOG DRIFTING UP FROM THE VALLEYS AS
IT BEGINS TO LIFT...HOWEVER JUST EXPECTING NO WORSE THAN MVFR AT
THOSE LOCATIONS. THE REST OF THE DAY WILL BE GREAT...WITH VFR ACROSS
ALL OF EASTERN KENTUCKY EXPECTED.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JJ
LONG TERM...SHALLENBERGER
AVIATION...JJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
259 AM EDT FRI MAY 23 2014
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 258 AM EDT FRI MAY 23 2014
THE ARE TWO THINGS GOING ON THIS MORNING. THE FIRST IS THE IS AREAS
OF DENSE VALLEY FOG AROUND THE AREA...ESPECIALLY SOUTH OF THE HAL
ROGERS PARKWAY. THE NEXT IS THE RADAR IS SHOWING SOME WEAK RETURNS
TRYING TO MOVING INTO THE BLUEGRASS REGION IN THE NEXT FEW HOURS AND
ALSO SOME STRONGER ECHOES OVER WESTERN KENTUCKY AND CENTRAL
TENNESSEE. OTHER THAN THE HRRR...NONE OF THE MODELS ARE HANDLING
THESE ISOLATED TO SCATTERED SHOWERS. THE HRRR WAS SHOWING THESE
SHOWERS WILL BE DYING AS THEY TRY TO ENTER EASTERN KENTUCKY THIS
MORNING. WILL BE GOING WITH THE HRRR...SINCE IT IS THE ONLY MODEL
WITH A CLUE RIGHT NOW. A WEAK COLD FRONT IS LYING ALONG THE
TENNESSEE AND KY BORDER. THIS FRONT IS FORECAST TO MOVE SLOWING
SOUTH WITH TIME AS HIGH PRESSURE BUILDS INTO THE AREA. EXPECT THE FOG
TO BE BURNING OFF BETWEEN 8 AND 9 AM THIS MORNING. THERE MAY BE SOME
DEBRIS CLOUDS MOVING INTO THE AREA THIS MORNING AND THEN DECREASING
CLOUDS THIS AFTERNOON AS THE FRONT PUSHES FURTHER TO THE SOUTH. THE
CONSENSUS BLEND LOOKED PRETTY GOOD AND THEN NUDGED IT TOWARD THE GFS
MOS FOR THE HIGHS TODAY AND TOMORROW.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 258 AM EDT FRI MAY 23 2014
THE EXTENDED DISCUSSION WILL BE ISSUED SHORTLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 135 AM EDT FRI MAY 23 2014
THERE IS SUFFICIENT LOW LEVEL MOISTURE IN THE VALLEYS TO PRODUCE FOG.
THE FOG SOUTH OF THE HAL ROGERS PARKWAY MAY BE DENSE PRODUCING
VISIBILITIES LESS THAN ON QUARTER MILE IN PLACES. SME AND LOZ WILL
LIKELY SEE SOME IFR FOG THIS MORNING THAT WILL BE BURNING OFF BETWEEN
13-14Z. JKL AND SJS MAY SEE SOME FOG DRIFTING UP FROM THE VALLEYS AS
IT BEGINS TO LIFT...HOWEVER JUST EXPECTING NO WORSE THAN MVFR AT
THOSE LOCATIONS. THE REST OF THE DAY WILL BE GREAT...WITH VFR ACROSS
ALL OF EASTERN KENTUCKY EXPECTED.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JJ
LONG TERM...SHALLENBERGER
AVIATION...JJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
135 AM EDT FRI MAY 23 2014
.UPDATE...
ISSUED AT 840 PM EDT THU MAY 22 2014
A COLD FRONT CONTINUES TO SAG SOUTH ACROSS THE REGION AND IS EXITING
INTO VA AND TN. CONVECTION HAS ALSO MOVED WELL SOUTH OF THE AREA OVER
PARTS OF NORTHEAST TN AND THE SMOKEY MOUNTAINS. DRIER AIR IS BEGINNING
TO FILTER IN FROM THE NORTHWEST WITH DEWPOINTS ALREADY IN THE MID 50S
ACROSS THE FAR NORTH. A FEW OBSERVATIONS OF FOG HAVE BEEN NOTED NEAR
WHERE HEAVIER RAIN OCCURRED EARLIER THIS EVENING...AT EKQ AND I35.
ADDITIONAL FOG DEVELOPMENT SHOULD OCCUR INTO THE OVERNIGHT HOURS AS
DRIER AIR WILL BE SLOWER TO FILTER INTO CENTRAL AND SOUTHERN PORTIONS
OF THE CWA. HOURLY GRIDS HAVE BEEN ADJUSTED ACCORDINGLY.
UPDATE ISSUED AT 635 PM EDT THU MAY 22 2014
WITH THE WORST OF THE STORMS SINKING SOUTH OUT OF EAST KENTUCKY HAVE
GONE AHEAD AND DROPPED THE SEVERE WATCH FOR WAYNE AND MCCREARY
COUNTIES. ALSO TAPERED OFF THE THUNDERSTORM CHANCES THROUGH THE REST
OF THE EVENING AND ADDED SOME PATCHY DENSE FOG TO THE VALLEYS LATE
TONIGHT. FINALLY...TWEAKED THE NEAR TERM GRIDS PER THE LATEST OBS AND
TRENDS. THESE GRID UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS
ALONG WITH THE DISSEMINATION OF THE ZFP AND WCN. AN UPDATED HWO IS IN
THE QUEUE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 415 PM EDT THU MAY 22 2014
19Z SFC ANALYSIS SHOWS LOW PRESSURE CENTERED OVER THE POCONOS WITH A
COLD FRONT STRETCHED SOUTHWEST AND BISECTING KENTUCKY. SOUTH OF THIS
FRONT DEWPOINTS ARE IN THE MID AND UPPER 60S WITH TEMPERATURES IN THE
MID 80S. CONDITIONS ARE JUST A BIT DRIER AND COOLER TO THE NORTHWEST
OF IT. TO THE SOUTH OF THE FRONT...INSTABILITY IS QUITE HIGH WITH
LIS IN THE -8 TO -10 DEGREE RANGE WITH CAPE TO 3500 J/KG OVER THE
WESTERN PORTION OF THE STATE. ON SATELLITE...THE CU IS DOING BEST
OVER SOUTHERN KENTUCKY...WHILE ON RADAR SOME RETURNS ARE FINALLY
SHOWING UP TO THE NORTHWEST OF BOWLING GREEN. EXPECT THESE TO DEVELOP
AND STRENGTHEN RAPIDLY WITH A GENERAL MOVEMENT TO THE EAST SOUTHEAST.
SPC HAS HIGHLIGHTED THIS AREA THROUGH SOUTHERN PARTS OF EAST KENTUCKY
FOR A POTENTIAL WATCH BOX. MEANWHILE...WINDS ARE MAINLY FROM THE WEST
AT 10 TO 20 KTS ACROSS EAST KENTUCKY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE FAST NORTHWEST FLOW
THROUGH NORTHEAST KENTUCKY BETWEEN A RETREATING RIDGE TO THE SOUTH
AND EXPANDING TROUGHING TO THE NORTH. A WEAK PATCH OF ENERGY WILL
PASS THROUGH THIS NORTHWEST FLOW KNOCKING DOWN HEIGHTS LOCALLY INTO
THE EVENING. THE RIDGE IS FURTHER SUPPRESSED ON FRIDAY IN RESPONSE TO
THE NORTHEAST TROUGH DIGGING THROUGH THE CENTRAL APPALACHIANS. ONCE
THIS TROUGH AND SHARP SHORTWAVE MOVES OUT OF THE AREA...HEIGHTS WILL
REBOUND OVER EAST KENTUCKY INTO SATURDAY MORNING. WITH THE GOOD MODEL
AGREEMENT WILL FOLLOW THE DETAILS FROM THE NAM12 AND THE LAST FEW
RUNS OF THE HRRR MOST PROMINENTLY.
SENSIBLE WEATHER WILL FEATURE SCATTERED STORMS OVER THE SOUTHERN
HALF OF THE CWA THIS EVENING...POTENTIALLY SEVERE ALONG THE TENNESSEE
BORDER. A WATCH BOX IS NOW OUT WITH WAYNE AND MCCREARY INCLUDED...AND
JUST IN TIME AS THE STORMS ARE QUICKLY DEVELOPING OVER OUR SOUTHERN
TIER. EXPECT THESE TO FADE OUT BY MIDNIGHT WITH SOME CLEARING HELPING
TO BUILD FOG THROUGH THE VALLEYS ACROSS EAST KENTUCKY. THE FOG COULD
BECOME LOCALLY DENSE IN THE DEEPEST VALLEYS. THE FRONT DRIFTS TO THE
SOUTH OF THE AREA ON FRIDAY TAKING THE THREAT OF SHOWERS AND
THUNDERSTORMS WITH IT. THIS SHOULD MAKE FOR A PLEASANT END TO THE
WORK WEEK WITH TEMPERATURES ABOUT 5 TO 10 DEGREES COOLER THAN TODAY.
LATER FRIDAY NIGHT...ANTICIPATE A DECENT RIDGE TO VALLEY TEMPERATURE
SPLIT GIVEN MOSTLY CLEAR SKIES AND HIGH PRESSURE MOVING BY TO THE
NORTH. SOME PATCHY VALLEY FOG CAN ALSO BE EXPECTED TO DEVELOP
TOWARDS DAWN SATURDAY.
USED THE BCCONSSHORT GRIDS AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS WITH THE BCCONSALL
ADDED TO THE END OF THE SHORT TERM THEREAFTER. MOST ADJUSTMENTS
WHERE MADE TO ACCOUNT FOR TERRAIN DIFFERENCES TONIGHT AND FRIDAY
NIGHT IN THE LOWS. AS FOR POPS...ENDED UP ON THE HIGH SIDE OF ALL
GUIDANCE TONIGHT AND THEN SINGLE DIGITS THROUGH THE REST OF THE
PERIOD...IN LINE WITH THE MOS NUMBERS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 PM EDT THU MAY 22 2014
CONDITIONS WILL STAY FAIRLY CONSTANT IN THE UPPER LEVELS DURING THE
EXTENDED...WITH THE MODELS IN FAIRLY GOOD AGREEMENT THROUGH DAY 7.
SATURDAY 12Z WILL START OFF THE PERIOD WITH AN UPPER LEVEL RIDGE
MOVING FROM THE CENTRAL PLAINS ACROSS EASTERN KY. THIS RIDGE WILL
REMAIN THE DRIVING FORCE THROUGH TUESDAY. FOR THE MID TERM SECTION
OF THE FORECAST PERIOD...ANY MOISTURE WILL REMAIN TO THE WEST OF THE
RIDGE...KEEPING MUCH OF KY BOTH DRY AND IN A SOUTHERLY WIND PATTERN.
THIS WILL ALLOW TEMPERATURES TO BOOST TO WELL ABOVE NORMAL THROUGH
EARLY NEXT WEEK. SATURDAY IS STILL EXPECTED TO BE THE COOLEST DAY AS
HIGH PRESSURE AND UPPER LEVEL RIDGING ARE JUST BEGINNING TO TAKE
CONTROL...WITH HIGHS NEAR CLIMATOLOGICAL NORMAL FOR THIS TIME OF
YEAR. TEMPERATURES SATURDAY NIGHT WILL SHOW A DECENT DIURNAL RANGE
WITH A THERMAL BELT SETTING UP AROUND THE RIDGES. THEN AS SOUTHERLY
FLOW TAKES CONTROL...TEMPS WILL BEGIN TO RISE INTO THE MID AND EVEN
SOME UPPER 80S BY TUESDAY OF NEXT WEEK.
MODELS ARE SHOWING SOME VARIATION IN SOME ISOLATED TO SCATTERED
AFTERNOON SHOWERS/TSTMS FOR MONDAY AND TUESDAY
AFTERNOON...ALTHOUGH NO PARTICULAR MODEL IS GOING TO HAVE A GOOD
HANDLE WHERE THEY WILL SET UP EXACTLY. THERE IS ENOUGH EVIDENCE TO
WARRANT ISOLATED CHANCES ON MONDAY...AND SCATTERED CHANCES ACROSS
EASTERN KY FOR TUESDAY. BY TUESDAY EVENING...LOW PRESSURE OVER THE
SOUTH CENTRAL PLAINS WILL HAVE SHIFTED EASTWARD SLIGHTLY AND WILL BE
ENTERING INTO THE MISSISSIPPI RIVER VALLEY. THIS WILL CREATE MORE
LIFT AND MOISTURE INFLUX...AS WELL AS CONTINUED WARM UNSTABLE
AIR...ALLOWING THE CHANCE OF SHOWERS AND THUNDERSTORMS TO CONTINUE
TUESDAY NIGHT INTO THURSDAY TO ROUND OUT OUR FORECAST PERIOD. STUCK
PRETTY CLOSE TO THE ALLBLEND FOR THE EXTENDED POPS DUE TO THE
UNCERTAINTY IN CONVECTION THIS FAR OUT IN THE FORECAST PERIOD.
SMOOTHED OUT ANY MAJOR BULLSEYES OF POPS AND LOWERED SOME OF THE
HIGHER END CHANCES THAT ARE HARD TO WARRANT THIS FAR OUT.
OTHERWISE...WE ARE MATCHING UP QUITE WELL WITH SURROUNDING OFFICES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 135 AM EDT FRI MAY 23 2014
THERE IS SUFFICIENT LOW LEVEL MOISTURE IN THE VALLEYS TO PRODUCE FOG.
THE FOG SOUTH OF THE HAL ROGERS PARKWAY MAY BE DENSE PRODUCING
VISIBILITIES LESS THAN ON QUARTER MILE IN PLACES. SME AND LOZ WILL
LIKELY SEE SOME IFR FOG THIS MORNING THAT WILL BE BURNING OFF BETWEEN
13-14Z. JKL AND SJS MAY SEE SOME FOG DRIFTING UP FROM THE VALLEYS AS
IT BEGINS TO LIFT...HOWEVER JUST EXPECTING NO WORSE THAN MVFR AT
THOSE LOCATIONS. THE REST OF THE DAY WILL BE GREAT...WITH VFR ACROSS
ALL OF EASTERN KENTUCKY EXPECTED.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...JJ
AREA FORECAST DISCUSSION
NWS GAYLORD MI
336 AM EDT FRI MAY 23 2014
.SYNOPSIS...
ISSUED AT 332 AM EDT FRI MAY 23 2014
HIGH PRESSURE WILL BUILD INTO THE REGION BY LATER TODAY AND REMAIN
IN CONTROL OF THE WEATHER THROUGH SUNDAY. THEREFORE...CLEARING SKIES
AND MODERATING TEMPERATURES WILL MOVE IN BY THIS AFTERNOON WITH
COMFORTABLE TEMPERATURES AND LOTS OF SUNSHINE EXPECTED FOR BOTH
SATURDAY AND SUNDAY. SHOWERS AND A FEW THUNDERSTORMS THEN LOOK
LIKELY MEMORIAL DAY AS A SYSTEM DROPS DOWN FROM THE NORTHWEST.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 332 AM EDT FRI MAY 23 2014
...CLOUDS GRADUALLY GIVE WAY TO SUN TODAY...
HIGH IMPACT WEATHER POTENTIAL: LOW THREAT OF FROST FOR INTERIOR
NORTHERN LOWER TONIGHT.
PATTERN SUMMARY: NORTHWEST FLOW ON CONTROL OF OUR REGION/S WEATHER
AS OF THIS WRITING WITH LOW HEIGHT ANOMALY OVER EASTERN
CANADA...WITH UPSTREAM HEIGHTS BUILDING OVER THE WESTERN UNITED
STATES NORTH OF A STATIONARY CUTOFF LOW ACROSS THE SOUTHWESTERN
PORTION OF THE COUNTRY. LAST IN A SERIES OF SHORTWAVES MAKING ITS
CLOSEST APPROACH TO NORTHERN MICHIGAN AS OF THIS WRITING...HELPING
SPAWN A FEW SPRINKLES ALONG THE COAST OF NORTHEAST LOWER MICHIGAN
AND NORTHERN LAKE HURON. AS THIS FEATURE CONTINUES TO MOVE SOUTH
AND EAST...SHORTWAVE RIDGING WILL BUILD IN IT/S PLACE. THIS IS
MANIFESTED AS A MODEST 1023 MB HIGH ALONG THE ONTARIO/MINNESOTA
BOARDER...WHICH WILL SLIDE INTO NORTHERN MICHIGAN THROUGH THE
UPCOMING FORECAST PERIOD. THIS SETUP SUGGESTS FAIR WEATHER...BUT WE
HAVE SOME LLEVEL STRATUS OVERHEAD ASSOCIATED WITH NEARBY SHORTWAVE
THAT WILL BE RELUCTANT TO LEAVE AND THUS COMPLICATE THE EARLY
PORTION OF THIS FORECAST THIS AM. BEYOND THIS...ATTENTION TURNS TO
WHAT LOOKS TO BE THE POTENTIAL FOR A CHILLY /FROSTY?/ NIGHT FRIDAY
NIGHT.
THROUGH DAYBREAK: STILL TRACKING AREA OF SPRINKLES ALONG THE COAST
OF NORTHEAST LOWER...THESE WILL CONTINUE TO SINK SOUTH WITH LOW
CLOUDS CONTINUING TO EXPAND ACROSS NORTHERN LOWER. ANY SPRINKLE
THREAT SHOULD END BY 09-10Z...WITH A LITTLE PATCHY DRIZZLE/SPRINKLE
ACTIVITY ALSO NOT OUT OF THE QUESTION THROUGH DAYBREAK ACROSS THE
HIGHER TERRAIN OF NORTHERN LOWER.
TODAY: PRIMARY CONCERN TODAY REVOLVES AROUND CLOUD COVER...IT/S
EROSION AND IMPACTS ON TEMPERATURES. PRETTY BIG MODEL DISPARITIES
IN HANDLING THE BOUNDARY LAYER MOISTURE FIELD THIS MORNING WITH THE
NAM MUCH MORE AGGRESSIVE IN MORNING CLEARING WHILE THE RAP AND OUR
IN HOUSE LOCAL WRF WOULD LIKE TO MAINTAIN LLEVEL SATURATION OVER
MUCH OF NORTHERN LOWER AT LEAST THROUGH THE NOON HOUR. TRACKING
BACK THIS CLOUD DECK 24 HOURS TO A LOCATION JUST WEST OF JAMES BAY
SUGGESTS A PRETTY SLOW CLEARING PROCESS...AND THAT IS IN LINE WITH
PATTERN RECOGNITION OF SOME MOISTURE GETTING TRAPPED BENEATH
DEVELOPING SUBSIDENCE INVERSION...AS WELL AS RECENT GFS LAMP
GUIDANCE. THUS...WILL DELAY CLEARING UNTIL ABOUT NOON OVER NORTHERN
LOWER...AND DURING THE MID MORNING OVER EASTERN UPPER. THE SUN WILL
EVENTUALLY WIN OUT...HOWEVER...WITH SKIES BECOMING MOSTLY CLEAR
TOWARDS EVENING.
TEMPERATURES /CONFIDENCE: MODERATE-HIGH/: EXPECT CLOUDS TO HAVE SOME
IMPACT ON TEMPERATURES...LIMITING THE DIURNAL HEATING WINDOW.
STILL...DAYS ARE LONG AND T8S AROUND +5-6 SUGGEST MID 60S FOR
HIGHS...AND EXPECT THAT WE/LL REACH THESE VALUES...BUT LATE IN THE
DAY.
TONIGHT: HIGH PRESSURE SETTLES OVERHEAD WITH VERY QUIET CONDITIONS
EXPECTED. WITH AMPLIFYING LONGWAVE RIDGE TO OUR WEST...
NAM/GFS/ECMWF WANT TO SPILL SOME MID/UPPER LEVEL MOISTURE OVER THE
ARRIVING MID LEVEL RIDGING...IMPACTING EASTERN UPPER AND FAR
NORTHERN LOWER AFTER MIDNIGHT. WILL INDICATE PARTLY CLOUDY SKIES
HERE...WITH MOSTLY CLEAR CONDITIONS TO THE SOUTH OF THIS. ONLY
POTENTIAL IMPACT OF THIS CLOUD COVER MAY BE TO KEEP A LID ON
TEMPERATURES FALLING TOO FAR IN THESE LOCALES.
TEMPERATURES /CONFIDENCE: MODERATE-HIGH/: CHILLY NIGHT IN STORE WITH
AFTERNOON DEWPOINTS LIKELY TO MIX OUT INTO THE UPPER 30S BY LATE IN
THE DAY IN SOME OF OUR INTERIOR DRY SPOTS. THIS WILL GIVE US PLENTY
OF ROOM TO COOL OVERNIGHT AS HIGH PRESSURE BUILDS OVERHEAD.
COMPLICATING FACTORS WILL BE POTENTIAL CLOUDS NORTH...AND SOME
RESIDUAL GRADIENT ALONG THE COAST OF NORTHEAST LOWER. STILL...
LOCALES FROM CAD TO GOV SHOULD BE ABLE TO CROSS INTO THE UPPER
30S...AND HAVE SOME CONCERNS WE MAY GO FURTHER THAN THIS DEPENDING
ON HOW TEMPS/DEWPOINTS EVOLVE TODAY /LATER CLEARING LIMITING
HIGHS/. WORST CASE SCENARIO /SIMILAR TO MAV/ WOULD ALLOW FOR A
LITTLE PATCHY FROST FOR THE INTERIOR /NO FREEZE EXPECTED/...BUT
EXPECTATIONS AT THIS TIME IS A LITTLE WARMER THAN THIS /ALTHOUGH
COOLER THAN INHERITED LOWS/. WILL PAINT UPPER 30S TO LOWER 40S WITH
NO HWO MENTION THIS GO AROUND.
&&
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 332 AM EDT FRI MAY 23 2014
...NICE START TO THE MEMORIAL DAY WEEKEND...
...HIGH IMPACT WEATHER POTENTIAL: NONE TO VERY LOW.
RIDGING AT THE SURFACE AND ALOFT PROMISES TO BRING PLEASANT LATE
SPRING CONDITIONS TO THE REGION SATURDAY INTO SUNDAY.
HOWEVER...NORTHERN STREAM ENERGY TRACKING ACROSS CANADA POSSIBLY IN
COMBINATION WITH A CUTOFF UPPER LOW EVIDENT ON WATER VAPOR IMAGERY
WILL LIKELY BRING SHOWERY CONDITIONS TO NORTHERN MICHIGAN FOR YOUR
MEMORIAL DAY (SORRY ABOUT THAT ONE). MORE RIDGING THEN BUILDS IN FOR
TUESDAY THROUGH THURSDAY LIKELY BRINGING ANOTHER DECENT STRETCH OF
WEATHER TO THE REGION.
SATURDAY INTO SUNDAY...SURFACE RIDGE CONTINUES TO MOVE ACROSS THE
REGION WITH HEIGHTS STEADILY RISING. A WEAK AND MOISTURE STARVED
SHORT WAVE SNEAKS UNDER THE RIDGE SATURDAY...WITH ONLY A PERIOD OF
MID LEVEL CLOUDS EXPECTED. OTHERWISE...CLEAR TO PARTLY CLOUDY SKIES
WITH PLEASANT TEMPERATURES ANTICIPATED. HIGHS MAINLY IN THE 70S
(EVEN A FEW LOWER 80S SUNDAY AFTERNOON) AND LOWS IN THE MIDDLE 40S
TO LOWER 50S.
SUNDAY NIGHT THROUGH MONDAY NIGHT...THE RIDGE TEMPORARILY BREAKS
DOWN ALLOWING A SYSTEM CRUISING ACROSS CANADA TO DROP DOWN FROM THE
NORTHWEST. A NICE LITTLE JET CORE IS SHOWN TO ACCOMPANY THIS FEATURE
SO IN COMBINATION WITH DAYTIME HEATING (AND POSSIBLY ENERGY FROM THE
WEAKENING CUTOFF UPPER LOW FROM THE SOUTHWEST)...SHOWERS AND
THUNDERSTORMS LOOK LIKELY. IN ADDITION...A NARROW THETA-E RIDGE
MOVES ACROSS THE REGION. EXPECT THE BEST CHANCE FOR SHOWERS AND
STORMS TO BE MONDAY AFTERNOON AND EVENING. IT IS STILL TOO EARLY TO
PIN DOWN SEVERE POTENTIAL BUT WILL HAVE TO MONITOR THE EVOLUTION OF
THE POSSIBLE JETLET AS A FEW STORMS MAY HAVE THE POTENTIAL TO BE ON
THE STRONGER SIDE.
TUESDAY THROUGH THURSDAY...PERHAPS SOME LOW CLOUDS AROUND TO START
OFF TUESDAY (THOUGH OVER LAKE INSTABILITY IS MUCH LESS THAN OUR
LATEST GO AROUND). OTHERWISE...RENEWED RIDGING AT THE SURFACE AND
ALOFT SHOULD LEAD TO ANOTHER STRETCH OF FINE LATE SPRING WEATHER.
HIGHS RANGING FROM THE MIDDLE 60S NORTH TO THE MIDDLE 70S SOUTH AND
LOWS IN THE MIDDLE 40S TO MIDDLE 50S (WHICH IS ALMOST PERFECT
SLEEPING WEATHER IF YOU ASK ME).
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 130 AM EDT FRI MAY 23 2014
PERIODS OF MVFR CIGS OVERNIGHT/EARLY FRIDAY.
HIGH PRESSURE NW OF SUPERIOR WILL DRIFT SE...FEEDING DRIER AIR INTO
THE REGION ON FRIDAY. A LAST ROUND OF LOW LEVEL MOISTURE/CLOUDS IS
DROPPING SOUTH ACROSS SUPERIOR AND UPPER MI. THIS WILL BRING MVFR
CIGS AT TIMES TO ALL TAF SITES. A FEW SPRINKLES WILL BE POSSIBLE
OVER THE NEXT 1-2 HOURS AT APN. DRIER AIR ARRIVES FRIDAY
MORNING...WITH CIGS GRADUALLY IMPROVING TO VFR DURING THE MORNING.
CLEAR SKIES EXPECTED FRIDAY EVENING.
NW WINDS...LIGHT TONIGHT INCREASING TO 10G18KTS FOR THE DAY ON
FRIDAY BEFORE DIMINISHING TO CALM/LIGHT-VARIABLE FRIDAY EVENING.
&&
.MARINE...
ISSUED AT 332 AM EDT FRI MAY 23 2014
SUMMARY: HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES REGION TODAY
AND TONIGHT...WITH NORTHWESTERLY WINDS GRADUALLY DECREASING. HIGH
PRESSURE WILL REMAIN OVERHEAD THROUGH SATURDAY BEFORE SHIFTING
SOUTH AND EAST OF THE REGION BY SUNDAY WITH LOW PRESSURE ARRIVING
SUNDAY NIGHT/MONDAY...WITH A ROUND OF SOUTHWEST WINDS BEFORE WINDS
SHIFT AGAIN TO THE NORTHWEST BY THE MIDDLE OF NEXT WEEK.
HEADLINES: MARGINAL SMALL CRAFT CONDITIONS POSSIBLE NEAR PRESQUE
ISLE FOR A TIME TODAY...OTHERWISE...HEADLINE FREE CONDITIONS LOOK TO
BE IN STORE THROUGH THE UPCOMING WEEKEND.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
SYNOPSIS...AS
SHORT TERM...ARNOTT
LONG TERM...AS
AVIATION...JZ/ARNOTT
MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS DULUTH MN
1136 PM CDT THU MAY 22 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 255 PM CDT THU MAY 22 2014
CLOUDS HAVE BEEN VERY SLOW TO DISSIPATE TODAY...HANGING TOUGH FROM
KINL TO KDLH TO KHYR AND KPBH. THE RAP HAS BEEN DOING A DECENT JOB
DEPICTING THESE CLOUDS. COLD TEMPS AND CYCLONIC FLOW ALOFT HAVE
CONTRIBUTED TO A FAVORABLE SET UP FOR THE CLOUDS.
THE CLOUDS HAVE BEEN SLOWLY DIMINISHING THIS AFTERNOON AND WITH
LOSS OF HEATING...WE EXPECT IT TO CONTINUE. THE RAP ALSO SHOWS THE
CLOUDS DIMINISHING THIS EVENING. THE HIGH WILL PASS OVER THE CWA
AND WINDS WILL BECOME LIGHT ALLOWING TEMPS TO COOL INTO THE MID
THIRTIES TO LOWER FORTIES. SOME OF THE COOLER LOCALES ACROSS THE
CWA MAY DROP TO NEAR FREEZING.
AS THE HIGH CONTINUES ITS SLOW EASTWARD TRACK FRIDAY...WINDS WILL COME
AROUND TO MORE SOUTHERLY FOR MOST AREAS. IT SHOULD BE WARMER WITH
MOST AREAS CLIMBING TO 69 TO 75. AREAS AROUND LAKE SUPERIOR WILL BE
COOLER WITH LIGHT ONSHORE WINDS EXPECTED. THERE SHOULD ALSO BE MORE
SUN AS UPPER LEVEL RIDGING AND WARMING TEMPS OCCUR.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 255 PM CDT THU MAY 22 2014
OVERALL SYNOPTIC SCALE PATTERN FEATURES A MID LVL RIDGE OVER NRN
PLAINS AND UPPER MIDWEST NEXT 5 TO 7 DAYS. WITHIN THAT REGIME THERE
IS SOME AGREEMENT AMONGST MED RANGE MDL SUITE THAT A PROGRESSIVE
SHORTWAVE TROF MAY DAMPEN RIDGE ENOUGH TO WARRANT AN EPISODE OF
PRECIP. AS MID LVL RIDGE MOVES INTO REGION THIS WEEKEND IT WILL
BE ACCOMPANIED BY A BROAD PATTERN OF WARM ADVECTION IN THE LOW/MID
LAYERS. A PROGRESSIVELY MORE MOIST ATMOSPHERE WILL DEVELOP AND
THERE IS A CHC THAT SCT CONVECTION MAY OCCUR AS EARLY AS SAT AFTN
OVER WRN CWA. HOWEVER WILL ACCEPT MDL TREND TO SLOW DOWN ARRIVAL
OF SUFFICIENT MOISTURE AND START PRECIP POTENTIAL SAT NIGHT.
GRADUAL INCREASE IN POPS SUNDAY WITH HIGHEST PROB OCCURRING SUN
NIGHT/EARLY MONDAY AS LARGE SCALE ASCENT IS MAXIMIZED WITH PASSAGE
OF SHORTWAVE ALOFT. SFC HIGH WILL BUILD SOUTH BEHIND THE DEPARTING
SHORTWAVE MONDAY. SOME TIMING DIFFERENCES WITH REGARD TO HOW SOON
THE PRECIP MOVES SOUTH OF THE CWA. BEYOND THAT UNCERTAINTY
INCREASES AS INITIAL SFC BDRY MOVES WELL SOUTH OF REGION TUESDAY
AND THEN POSSIBLY RETREATS NORTH BY MIDWEEK. ALLBLEND SOLUTION
GIVES POPS ACROSS SRN CWA TUES/WED HOWEVER NOT CONFIDENT THAT
ENOUGH MOISTURE IS EVIDENT. WILL LET NEXT SHIFT SHIFT TO A DRIER
PATTERN IF MDL TRENDS CONTINUE. TEMPS REMAIN ABOVE NORMAL THROUGH
PERIOD AS 50H PATTERN ADVERTISES ANOMALOUS RIDGING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1136 PM CDT THU MAY 22 2014
VFR THROUGH THE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 41 70 46 75 / 0 0 0 10
INL 39 73 50 79 / 0 0 10 10
BRD 42 75 55 79 / 0 0 10 10
HYR 38 75 45 76 / 0 0 0 10
ASX 39 68 43 72 / 0 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MELDE
LONG TERM...CANNON
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
359 AM CDT FRI MAY 23 2014
.SYNOPSIS...
ISSUED AT 300 AM CDT FRI MAY 23 2014
A MESOSCALE VORTICITY CENTER APPEARS LOCATED NEAR LAMAR CO FROM
EARLIER MCS WHICH DEVELOPED AND MOVED NORTHEAST FROM EASTERN NEW
MEXICO. THE LEADING EDGE OF THIS CONVECTION HAS PERSISTED ACROSS
NORTHWEST KANSAS AND SOUTHWEST NEBRASKA WITH A SLOW PROPAGATION TO
THE NORTH. DUE TO SLOW OVERALL STORM MOVEMENT...HEAVY RAINFALL
INDICATED BY RADAR FROM SERN CHASE INTO HAYES COUNTY. TEMPERATURES
ACROSS WRN NEBR RANGED IN THE UPPER 50S TO LOWER 60S WITH DEWPOINTS
IN THE MID 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CDT FRI MAY 23 2014
A CLOSED UPPER LOW WAS LOCATED IN FAR SRN CALIF EARLY THIS MORNING
WITH UPSTREAM RIDGING FROM THE LOWER MISSISSIPPI VALLEY
NORTHWESTWARD INTO WYOMING. MAIN AREA OF CONVECTION FROM WESTERN
KANSAS INTO SWRN NEBR WILL CONTINUE TO MOVE NORTH PRIOR TO 12Z. AN
APPARENT MVC NEAR LAMA CO SHOULD CONTINUED LIFT NORTHEAST TODAY
ALONG WITH A MID LEVEL DISTURBANCE. BOTH THE NAM AND GFS DEVELOP
PRECIPITATION BOTH TODAY AND TONIGHT ACROSS WRN NEBR. THE HIGHER
LIKELY POPS TODAY INTO THIS EVENING ARE PLACED ACROSS THE SOUTHEAST
PANHANDLE INTO SOUTHWEST NEBR. NORTHEAST COUNTIES SHOULD REMAIN DRY
TODAY WITH A SLIGHT CHANCE BY LATE AFTERNOON. IN ADDITION...BOTH THE
RAP AND HRRR MODELS INDICATE SHOWER AND THUNDERSTORM DEVELOPMENT
SHOULD OCCUR QUICKLY AFTER 15Z FROM SWRN NEBR INTO THE WESTERN
SANDHILLS. DUE TO WEAK DEEP LAYER SHEAR LESS THAN 20 KTS...STRONG OR
SEVERE STORMS ARE UNLIKELY. STORM MOTION TO THE NORTH AND NORTHEAST
WILL ONLY BE 10 TO 15 MPH...WITH HEAVY RAINFALL POSSIBLE WITH
TRAINING CELLS.
SKIES TO BE MOSTLY CLOUDY TODAY WITH HIGHS FROM NEAR 70 IN SWRN NEBR
TO AROUND 75 IN THE NORTHEAST WHERE A BIT MORE SUN EXPECTED.
CHANCES FOR SHOWERS AND THUNDERSTORMS FALL TO AROUND 30 PERCENT
AFTER MIDNIGHT TONIGHT...WITH SLIGHTLY BETTER CHANCES FROM CENTRAL
KANSAS INTO EASTERN NEBRASKA. WITH MAINLY CLOUDY SKIES AND DEWPOINTS
IN THE MID 50S...OVERNIGHT LOWS WILL MOSTLY RANGE IN THE UPPER 50S.
THE UPPER LEVEL LOW MEANWHILE WILL MOVE SLOWLY INTO CENTRAL ARIZONA
OVERNIGHT WITH A CONTINUED FETCH OF GULF MOISTURE FROM THE SOUTHERN
INTO THE CENTRAL PLAINS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 300 AM CDT FRI MAY 23 2014
CLOSED UPPER LEVEL LOW PRESSURE SYSTEM WILL PROGRESS VERY SLOWLY
TO THE EAST ACROSS THE SOUTHERN PLAINS THROUGH THE PERIOD. OUR
AREA WILL CONTINUE TO BE INFLUENCED FROM THE SYSTEM THROUGH AT
LEAST TUESDAY...WITH SCATTERED SHOWERS AND THUNDERSTORMS. PLENTY
OF GULF MOISTURE WILL BE IN PLACE SO SOME HEAVY RAIN IS POSSIBLE
WHERE STORMS DEVELOP. OVERALL SEVERE THREAT IS LOW DUE TO WEAK
WINDS ALOFT...BUT THIS WILL AID IN THE POSSIBILITY OF HEAVY
RAINFALL DUE TO SLOW MOVING STORMS. COVERAGE WILL BE
SCATTERED...AS NO REAL BOUNDARY TO FOCUS CONVECTION ON. THE
EXCEPTION WILL BE SUNDAY AFTERNOON AND EVENING...WHEN A WEAK COLD
FRONT WILL SAG INTO NORTHERN NEBRASKA. MAY SEE A BIT MORE COVERAGE
OF STORMS INVOF OF THE FRONT. WILL CONTINUE TO BLANKET THE AREA
WITH 30 POPS FOR MUCH OF THE WEEKEND...BUT WILL HAVE A SLIGHTLY
HIGHER 40 POP ACROSS THE NORTH SUNDAY NEAR THE FRONT.
WITH THE GULF MOISTURE WELL ESTABLISHED ACROSS THE
PLAINS...TEMPERATURES WILL BE MILD. THERE WILL BE LOW STRATUS
CLOUDS AROUND AT TIMES...BUT ALL MODELS INSIST THAT THERE WILL BE
AT LEAST SOME SUNSHINE EACH DAY THROUGH THE MEMORIAL DAY WEEKEND.
SHOULD SEE HIGHS IN THE 70S SATURDAY...AND WITH POSSIBLY MORE
SUNSHINE SUNDAY...HIGHS COULD REACH AROUND 80. LITTLE CHANGE IN
TEMPERATURES INTO MOST OF NEXT WEEK...WITH HIGHS UPPER 70S TO
LOWER 80S. LOWS WILL BE MILD...IN THE MID 50S TO LOWER 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 358 AM CDT FRI MAY 23 2014
MVFR CEILINGS NEAR BKN020 HAVE DEVELOPED AT KLBF AND SHOULD
PERSIST TODAY. AN AREA OF SHOWERS AND THUNDERSTORMS IN SWRN NEBR
SHOULD GRADUALLY LIFT INTO THE KLBF TERMINAL BY 12Z WITH OFF AND ON
SHOWERS THROUGH THE DAY. VFR CONDITIONS FORECAST AT KVTN...WITH
PROBABILITY TOO LOW TO INCLUDE MENTION FOR SHOWERS ATTM.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...TAYLOR
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
340 AM CDT FRI MAY 23 2014
.SYNOPSIS...
ISSUED AT 300 AM CDT FRI MAY 23 2014
A MESOSCALE VORTICITY CENTER APPEARS LOCATED NEAR LAMAR CO FROM
EARLIER MCS WHICH DEVELOPED AND MOVED NORTHEAST FROM EASTERN NEW
MEXICO. THE LEADING EDGE OF THIS CONVECTION HAS PERSISTED ACROSS
NORTHWEST KANSAS AND SOUTHWEST NEBRASKA WITH A SLOW PROPAGATION TO
THE NORTH. DUE TO SLOW OVERALL STORM MOVEMENT...HEAVY RAINFALL
INDICATED BY RADAR FROM SERN CHASE INTO HAYES COUNTY. TEMPERATURES
ACROSS WRN NEBR RANGED IN THE UPPER 50S TO LOWER 60S WITH DEWPOINTS
IN THE MID 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CDT FRI MAY 23 2014
A CLOSED UPPER LOW WAS LOCATED IN FAR SRN CALIF EARLY THIS MORNING
WITH UPSTREAM RIDGING FROM THE LOWER MISSISSIPPI VALLEY
NORTHWESTWARD INTO WYOMING. MAIN AREA OF CONVECTION FROM WESTERN
KANSAS INTO SWRN NEBR WILL CONTINUE TO MOVE NORTH PRIOR TO 12Z. AN
APPARENT MVC NEAR LAMA CO SHOULD CONTINUED LIFT NORTHEAST TODAY
ALONG WITH A MID LEVEL DISTURBANCE. BOTH THE NAM AND GFS DEVELOP
PRECIPITATION BOTH TODAY AND TONIGHT ACROSS WRN NEBR. THE HIGHER
LIKELY POPS TODAY INTO THIS EVENING ARE PLACED ACROSS THE SOUTHEAST
PANHANDLE INTO SOUTHWEST NEBR. NORTHEAST COUNTIES SHOULD REMAIN DRY
TODAY WITH A SLIGHT CHANCE BY LATE AFTERNOON. IN ADDITION...BOTH THE
RAP AND HRRR MODELS INDICATE SHOWER AND THUNDERSTORM DEVELOPMENT
SHOULD OCCUR QUICKLY AFTER 15Z FROM SWRN NEBR INTO THE WESTERN
SANDHILLS. DUE TO WEAK DEEP LAYER SHEAR LESS THAN 20 KTS...STRONG OR
SEVERE STORMS ARE UNLIKELY. STORM MOTION TO THE NORTH AND NORTHEAST
WILL ONLY BE 10 TO 15 MPH...WITH HEAVY RAINFALL POSSIBLE WITH
TRAINING CELLS.
SKIES TO BE MOSTLY CLOUDY TODAY WITH HIGHS FROM NEAR 70 IN SWRN NEBR
TO AROUND 75 IN THE NORTHEAST WHERE A BIT MORE SUN EXPECTED.
CHANCES FOR SHOWERS AND THUNDERSTORMS FALL TO AROUND 30 PERCENT
AFTER MIDNIGHT TONIGHT...WITH SLIGHTLY BETTER CHANCES FROM CENTRAL
KANSAS INTO EASTERN NEBRASKA. WITH MAINLY CLOUDY SKIES AND DEWPOINTS
IN THE MID 50S...OVERNIGHT LOWS WILL MOSTLY RANGE IN THE UPPER 50S.
THE UPPER LEVEL LOW MEANWHILE WILL MOVE SLOWLY INTO CENTRAL ARIZONA
OVERNIGHT WITH A CONTINUED FETCH OF GULF MOISTURE FROM THE SOUTHERN
INTO THE CENTRAL PLAINS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 300 AM CDT FRI MAY 23 2014
CLOSED UPPER LEVEL LOW PRESSURE SYSTEM WILL PROGRESS VERY SLOWLY
TO THE EAST ACROSS THE SOUTHERN PLAINS THROUGH THE PERIOD. OUR
AREA WILL CONTINUE TO BE INFLUENCED FROM THE SYSTEM THROUGH AT
LEAST TUESDAY...WITH SCATTERED SHOWERS AND THUNDERSTORMS. PLENTY
OF GULF MOISTURE WILL BE IN PLACE SO SOME HEAVY RAIN IS POSSIBLE
WHERE STORMS DEVELOP. OVERALL SEVERE THREAT IS LOW DUE TO WEAK
WINDS ALOFT...BUT THIS WILL AID IN THE POSSIBILITY OF HEAVY
RAINFALL DUE TO SLOW MOVING STORMS. COVERAGE WILL BE
SCATTERED...AS NO REAL BOUNDARY TO FOCUS CONVECTION ON. THE
EXCEPTION WILL BE SUNDAY AFTERNOON AND EVENING...WHEN A WEAK COLD
FRONT WILL SAG INTO NORTHERN NEBRASKA. MAY SEE A BIT MORE COVERAGE
OF STORMS INVOF OF THE FRONT. WILL CONTINUE TO BLANKET THE AREA
WITH 30 POPS FOR MUCH OF THE WEEKEND...BUT WILL HAVE A SLIGHTLY
HIGHER 40 POP ACROSS THE NORTH SUNDAY NEAR THE FRONT.
WITH THE GULF MOISTURE WELL ESTABLISHED ACROSS THE
PLAINS...TEMPERATURES WILL BE MILD. THERE WILL BE LOW STRATUS
CLOUDS AROUND AT TIMES...BUT ALL MODELS INSIST THAT THERE WILL BE
AT LEAST SOME SUNSHINE EACH DAY THROUGH THE MEMORIAL DAY WEEKEND.
SHOULD SEE HIGHS IN THE 70S SATURDAY...AND WITH POSSIBLY MORE
SUNSHINE SUNDAY...HIGHS COULD REACH AROUND 80. LITTLE CHANGE IN
TEMPERATURES INTO MOST OF NEXT WEEK...WITH HIGHS UPPER 70S TO
LOWER 80S. LOWS WILL BE MILD...IN THE MID 50S TO LOWER 60S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 644 PM CDT THU MAY 22 2014
VISUAL FLIGHT RULES EXPECTED THROUGH MIDNIGHT AT TERMINALS KLBF
AND KVTN. SOUTHEAST WINDS ARE DRAWING MOISTURE NORTHWEST WHERE BEYOND
MIDNIGHT BOUNDARY LAYER MOISTURE IS FORECAST TO DEEPEN ACROSS
SOUTHWEST NEBRASKA. THE MODELS DIFFER IN THE APPROACH WITH LOW
CLOUDS FORMING AOB 2500 FEET...BEYOND 06Z. THEN AREAS OF FOG MAY
ALSO DEVELOP AND INCLUDED IN THE KLBF TERMINAL BEYOND 09Z THEN CLOUDS
LIFTING...OR DISSIPATING BEYOND 15Z TO VISUAL FLIGHT RULES.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...TAYLOR
AVIATION...KECK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1257 AM CDT FRI MAY 23 2014
.UPDATE...
ISSUED AT 1227 AM CDT FRI MAY 23 2014
ISOLATED THUNDERSTORMS HAVE DEVELOPED EARLY THIS MORNING...MAINLY
ALONG THE HIGHWAY 83 CORRIDOR. BEFORE DAYBREAK...THE FOCUS IS EXPECTED TO
SHIFT MORE INTO THE JAMES RIVER VALLEY...WHERE A BROADER ACCAS
FIELD IS CURRENTLY LOCATED. AN ISOLATED STRONGER STORM WITH SMALL
HAIL IS NOT OUT OF THE QUESTION.
UPDATE ISSUED AT 929 PM CDT THU MAY 22 2014
NEW MODEL RUNS OF RAP AND NAM SHOW SOME CONVECTION BEGINNING
AROUND MIDNIGHT OR SHORTLY AFTER IN THE JAMES RIVER VALLEY.
SHIFTED THE FOCUS ON THIS AREA OVERNIGHT. ADDED CLOUDS ALSO TO THE
CENTRAL AND EAST. OTHERWISE NO OTHER CHANGES.
UPDATE ISSUED AT 621 PM CDT THU MAY 22 2014
MID LEVEL WARM ADVECTION SUPPORTING FLAT CUMULUS FIELD ACROSS WEST
AND CENTRAL NORTH DAKOTA. BUFKIT SOUNDINGS FROM 12Z NAM SHOWING
LIMITED POTENTIAL TO GROW WITH MID LEVEL WARM LAYER KEEPING THE
CONVECTION IN CHECK. THUS BELIEVE THE NAM SO FAR HAS A BETTER
HANDLE ON THE CONVECTIVE POTENTIAL. TRIMMED POPS BACK FOR THE
EVENING BUT DID KEEP SMALL POPS ACROSS THE FAR WEST AND SOUTHWEST
WHERE MID LEVEL WARM LAYER WEAKER.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 250 PM CDT THU MAY 22 2014
MAIN FORECAST ISSUE THIS AFTERNOON WILL BE THUNDERSTORM CHANCES.
CURRENTLY...ATMOSPHERE CONTINUES TO DESTABILIZE OVER EASTERN
MONTANA INTO WESTERN NORTH DAKOTA. HOWEVER...MID LEVEL CAPPING AND
WEAK SHEAR WILL INHIBIT CONVECTION LATE THIS AFTERNOON AND
OVERNIGHT. CAN NOT RULE OUT A FEW THUNDERSTORMS AND HAVE
MAINTAINED A SLIGHT CHANCE OF THUNDER IN THE SOUTHWEST LATE THIS
AFTERNOON AND INTO THE CENTRAL TONIGHT.
FRIDAY WILL BRING ANOTHER CHANCE OF AFTERNOON AND EVENING
THUNDERSTORMS. SHEAR PROFILE REMAINS WEAK WITH A MID LEVEL RIDGE
OVER THE AREA. HOWEVER...WE WILL SEE INCREASING LOW LEVEL MOISTURE
AS DEWPOINTS INCREASE WELL INTO THE 50S. WE SHOULD ALSO BE A GOOD
4 TO 8 DEGREES WARMER...THUS THE RISK OF STORMS WILL BE A LITTLE
GREATER AND THE SEVERE THREAT...ALTHOUGH STILL MINIMAL...WILL BE
GREATER THAN THIS AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 250 PM CDT THU MAY 22 2014
AN UNSETTLED WEATHER PATTERN REMAINS ON TRACK FOR THIS UPCOMING
WEEKEND FOLLOWED BY A BRIEF LULL FOR MOST OF MONDAY AND TUESDAY.
SUCCESSIVE SHORTWAVES RETURN WITH PERIODIC CHANCES FOR SHOWERS AND
THUNDERSTORMS WEDNESDAY AND THURSDAY. SOME DISCREPANCY IN THE
GFS/ECMWF SOLUTIONS BEGINNING MONDAY IN TERMS OF TIMING OF
SHORTWAVES AND COVERAGE OF PRECIPITATION. THROUGHOUT THE LONG TERM
PERIOD EXPECT HIGH TEMPERATURES IN THE 70S TO AROUND 80...WITH
OVERNIGHT LOWS IN THE 50S.
FOR FRIDAY NIGHT INTO SATURDAY NIGHT...INCREASING LOW LEVEL
MOISTURE/DEWPOINTS VIA A SOUTHERLY FLOW WILL RESULT IN PRECIPITABLE
WATER VALUES OF BETWEEN AN INCH AND ONE AND A HALF INCHES ACROSS
SOUTHERN NORTH DAKOTA FRIDAY NIGHT INTO EARLY SUNDAY...WHICH
INCLUDES DICKINSON...BISMARCK...AND JAMESTOWN. MAIN PLAYER IS AN
UPPER LOW SPINNING OVER NEVADA WHICH WILL EJECT A SIGNIFICANT MID
LEVEL SHORTWAVE INTO WESTERN SOUTH DAKOTA 12Z SATURDAY...AND THEN
TRACKING INTO NORTH CENTRAL NORTH DAKOTA BY SATURDAY EVENING. THE
MID LEVEL SHORTWAVE IS FORECAST TO BECOME A CLOSED LOW SATURDAY
NIGHT AS IT SLOWS UP AND SCOOTS INTO SOUTHERN MANITOBA. AT THE
SURFACE A COLD FRONT WILL BE SLIDING ACROSS WESTERN NORTH DAKOTA
SATURDAY EVENING AND THEN INTO PORTIONS OF CENTRAL NORTH DAKOTA
EARLY SUNDAY MORNING. SUFFICIENT INSTABILITY WILL BE IN PLACE WITH
0-6KM BULK SHEAR INCREASING TO AROUND 30KT DURING THE AFTERNOON
WHICH SHOULD LEAD TO A BETTER POTENTIAL FOR SEVERE THUNDERSTORMS
ESPECIALLY IN THE WEST...CLOSER TO THE SURFACE LOW AND MID LEVEL
SHORTWAVE. IN ADDITION...THE NAM/GFS SOUNDINGS INDICATE A FATTER
CAPE/LARGER AREA/POTENTIALLY STRONGER UPDRAFTS WILL RESIDE AT KISN
SOUTH TO KDIK SATURDAY AFTERNOON/EVENING. SPC HAS THIS AREA IN A SEE
TEXT INDICATING A HIGHER POTENTIAL OF SEVERE WEATHER AT THIS TIME.
OTHERWISE THERE IS GOOD AGREEMENT IN THE AREAL COVERAGE OF
PRECIPITATION ACROSS WESTERN AND CENTRAL NORTH DAKOTA AND HAVE
INCREASED POPS TO LIKELY AND/OR CATEGORICAL IN SOME AREAS BASED ON
THIS SATURDAY AFTERNOON AND EVENING.
ON SUNDAY...AS MENTIONED ABOVE...A SURFACE COLD FRONT WILL BE MOVING
INTO CENTRAL NORTH DAKOTA IN THE MORNING AND INTO THE SOUTHERN JAMES
RIVER VALLEY LATE IN THE AFTERNOON. COOLER/DRIER AIR AND MORE STABLE
CONDITIONS WILL NOSE INTO THE FAR WEST BY AFTERNOON WITH A MINIMAL
THREAT FOR PRECIPITATION. HOWEVER DECENT INSTABILITY AND SHEAR
APPEARS TO RESIDE IN SOUTH CENTRAL NORTH DAKOTA SPECIFICALLY OVER
THE SOUTHERN JAMES RIVER VALLEY. THIS LOOKS TO BE THE POSSIBLE
TARGET AREA FOR SEVERE WEATHER SUNDAY AFTERNOON AND EVENING.
MONDAY AND TUESDAY...MID LEVEL RIDGING THEN TAKES CONTROL BEHIND
SUNDAYS SHORTWAVE RESULTING IN DRY WEATHER MONDAY AND MONDAY NIGHT.
THE ECMWF IS FASTER IN SHIFTING ANOTHER SHORTWAVE THROUGH MONDAY
NIGHT INTO TUESDAY MAINLY AFFECTING THE NORTHWEST AND NORTH CENTRAL.
THE GFS IS MAINLY DRY. AFTER COLLABORATING WITH NEIGHBORING OFFICES
HAVE REDUCED POPS DURING THIS PERIOD PER WHAT THE ALLBLEND WAS
INDICATING. SOUTHERLY FLOW WILL ONCE AGAIN INCREASE TUESDAY ALLOWING
A LOW LEVEL MOISTENING TREND INTO WESTERN AND CENTRAL NORTH DAKOTA.
WEDNESDAY INTO THURSDAY...SUCCESSIVE SHORTWAVES EMBEDDED WITHIN A
SOUTHWEST FLOW WILL ONCE AGAIN RESULT IN MORE SHOWERS AND
THUNDERSTORMS FOR WESTERN AND CENTRAL NORTH DAKOTA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1227 AM CDT FRI MAY 23 2014
WIND FLOW AROUND HIGH PRESSURE ACROSS MINNESOTA WILL MAINTAIN A
SOUTHERLY FLOW OF AIR ACROSS THE DAKOTAS THROUGH THE TAF PERIOD.
VFR EXPECTED. WIDELY SCATTERED/ISOLATED THUNDERSTORMS POSSIBLE
CENTRAL WITH THE JAMES RIVER VALLEY SEEING SCATTERED
THUNDERSTORMS AFTER MIDNIGHT. WILL INCLUDE A VCTS FOR KJMS
TONIGHT. OTHERWISE TIMING AND LOCATION AT OTHER TAF SITES ARE
UNCERTAIN THEREFORE DID NOT INCLUDE IN TAF FORECASTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RP KINNEY
SHORT TERM...TWH
LONG TERM...KS
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
150 AM EDT FRI MAY 23 2014
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH OF THE REGION INTO THE TENNESSEE RIVER
VALLEY OVERNIGHT. HIGH PRESSURE BEHIND THE FRONT WILL BUILD ACROSS
THE AREA FRIDAY THROUGH SATURDAY NIGHT. FAIR WEATHER AND SEASONABLE
TEMPERATURES ARE EXPECTED TONIGHT THROUGH SATURDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WITH EXTRAORDINARY LIGHT SPRINKLES OBSERVED AT NWS
WILMINGTON...AND A CONSISTENT SIGNAL ON THE HRRR THAT LIGHT ECHOES
WILL PASS OVER THE SOUTHERN THIRD OF THE CWA OVER THE NEXT 4-8
HOURS...A SLIGHT CHANCE OF SPRINKLES HAS BEEN ADDED TO THE
FORECAST FOR THE SOUTHERN TWO OR THREE TIERS OF COUNTIES.
OTHERWISE...VERY FEW CHANGES WERE NECESSARY...WITH TEMPERATURES
APPEARING TO BE ON TRACK. WHERE CLEARER SKIES ARE MORE LIKELY IN
THE FAR NORTH...TEMPERATURES WERE LOWERED JUST A COUPLE DEGREES.
PREVIOUS DISCUSSION >
SPLIT FLOW MID/UPR LEVEL FLOW PATTERN WITH CLOSED LOW OVER THE SW
U.S. AND RIDGE OVER THE GULF STATES. BAND OF NW MID LEVEL FLOW
FROM THE WESTERN GREAT LAKES INTO THE OHIO VALLEY TO PREVAIL
OVERNIGHT. SFC COLD FRONT OVER NORTHERN KENTUCKY TO PUSH SOUTH
INTO THE TN VALLEY AND STALL OUT OVERNIGHT. SOME HIGH AND MID LEVEL
CLOUDS DEBRIS CLOUDS FROM DECAYING CONVECTION WILL SPILL INTO THE
REGION THRU THE EARLY MORNING HOURS. GENERALLY EXPECT A PARTLY
CLOUDY SKY WITH CLOUDS THINNING OUT LATE ESPECIALLY NORTH.
TONIGHTS LOWS WILL BE COOLER WITH DRIER AIR FILTER IN. READINGS TO
TO RANGE FROM THE UPPER 40S NW TO THE MID 50S SE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
NORTHWEST MID/UPR LEVEL FLOW TO PERSIST THRU THE FCST PERIOD. SURFACE
HIGH PRESSURE WILL BUILD SOUTHEASTWARD INTO THE AREA FRIDAY...BECOMING
CENTERED OVER OUR AREA FRIDAY NIGHT. EXPECT PARTLY CLOUDY SKY CONDITIONS
DURING THE DAYLIGHT HOURS WITH SKIES BECOMING MOSTLY CLEAR FRIDAY NIGHT.
WITH THE DRIER AIR ADVECTING INTO THE REGION...DEWPOINTS TO DROP
INTO THE MID AND UPPER 40S. HIGHS ON FRIDAY WILL RANGE FROM NEAR
70 NE TO THE MID 70S SW. IN DRY AIRMASS WITH LIGHT WIND FLOW EXPECT
FRIDAY NIGHTS LOWS TO RANGE FROM THE UPPER 40S NE TO THE LOWER 50S SW.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
SURFACE HIGH WILL RIDE A NORTHWEST UPPER FLOW ACROSS THE AREA
SATURDAY AND SUNDAY TO BECOME CENTERED TO THE SOUTHEAST ON MONDAY.
THIS WILL KEEP A DRY WEATHER PATTERN OVER THE ILN FA.
THE HIGH WILL MOVE FARTHER TO THE EAST ON TUESDAY...WHILE SHORT WAVE
ENERGY AND MOISTURE START TO SPILL INTO THE OHIO VALLEY OVER AN
ERODING UPPER RIDGE. THIS SCENARIO WILL PRODUCE A CHANCE OF
THUNDERSTORMS TUESDAY INTO WEDNESDAY. ON THURSDAY WE MAY SEE A
RETURN TO DRY CONDITIONS AS THE UPPER RIDGE STRENGTHENS AHEAD OF AN
UPPER LOW CENTERED OVER THE GREAT PLAINS.
TEMPERATURES WILL EXHIBIT A WARMING TREND IN RELATION TO THE
MOVEMENT OF THE HIGH PRESSURE. AFTER HIGHS REACH THE 70S ON
SATURDAY...READINGS WILL RISE PRIMARILY INTO THE 80S SUNDAY THROUGH
THURSDAY DUE TO WARM ADVECTION AND INSOLATION.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. A FEW
SPRINKLES WILL BE POSSIBLE AT KCVG AND KLUK AT THE BEGINNING OF
THE TAF PERIOD. DUE TO THE LIGHT AND ISOLATED NATURE OF THE
SPRINKLES LEFT PRECIPITATION MENTION OUT OF THE TAFS. CU WILL
DEVELOP DURING THE DAY ON FRIDAY AND DECREASE IN COVERAGE FRIDAY EVENING.
OUTLOOK...THUNDERSTORMS ARE POSSIBLE ON TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...HATZOS/AR
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...NOVAK
AREA FORECAST DISCUSSION
NWS NORMAN OK
227 AM CDT FRI MAY 23 2014
.UPDATE...
WINDS... PRECIP/WX... TEMPS...
&&
.DISCUSSION...
WINDS HAVE REMAINED ELEVATED ACROSS FAR WRN OK OVERNIGHT...
PRIMARILY DUE TO A MESOHIGH THAT CONTINUES TO PERSIST ACROSS NWRN
OK/SWRN KS THIS MORNING. WINDS HAVE SLOWLY DECREASED THROUGH THE
EARLY MORNING HOURS... BUT SOME LOCATIONS CONTINUE TO EXPERIENCE
NORTH WINDS OF 10 TO 15 MPH... GUSTING TO 20 MPH. GUIDANCE FROM
THE RAP AND HRRR HAVE THE SFC PRESSURE GRADIENT CONTINUING TO
WEAKEN THROUGH THE EARLY MORNING... WHICH ALIGNS WELL WITH
CURRENT SFC ANALYSIS.
ADJUSTED POPS GIVEN RADAR TRENDS... LIGHT SHOWERS AND A FEW
RUMBLES OF THUNDER CONTINUE TO MEANDER ACROSS W TX AND ACROSS WRN
OK THIS MORNING. THIS ACTIVITY IS EXPECTED TO CONTINUE THROUGH THE
MORNING. TEMPS REMAIN ON TRACK... BUT ADJUSTED SLIGHTLY OVER THE
NEXT FEW HOURS GIVEN OBS TREND.
JTK
&&
.PREV DISCUSSION... /ISSUED 1045 PM CDT THU MAY 22 2014/
DISCUSSION...
AVIATION DISCUSSION FOR THE 06Z TAFS IS BELOW.
AVIATION...
VFR CONDITIONS ARE MAINLY EXPECTED.
ISO-SCT SHRA WILL AFFECT KWWR AND KGAG FOR THE
NEXT 24 HOURS. WILL KEEP VCSH MENTION AT THESE SITES.
ISO-SCT SHRA/TSRA WILL DEVELOP ACROSS MUCH OF THE
AREA 15-21Z...THE CONTINUE AFTER 21Z. WILL KEEP
VCSH MENTION FOR NOW THINKING MOST ACTIVITY WILL
NOT HAVE A SIGNIFICANT AMOUNT OF THUNDER.
IF A SHRA/TSRA DIRECTLY AFFECTS A GIVEN SITE...BRIEF
MVFR/IFR CONDITIONS AND VARIABLE GUSTY WINDS WOULD
BE POSSIBLE.
MVFR/IFR CONDITIONS MAY DEVELOP NEAR KWWR AND KGAG
AFTER 08Z...AND ACROSS ALL OF WESTERN OKLAHOMA AFTER 03Z
SATURDAY...BUT WILL NOT MENTION DUE TO LOW CONFIDENCE.
MBS
PREV DISCUSSION... /ISSUED 831 PM CDT THU MAY 22 2014/
DISCUSSION...
CONVECTION THAT FORMED ON THE OLD BOUNDARY ACROSS NORTHWEST
OKLAHOMA THIS AFTERNOON IS GRADUALLY DIMINISHING. IT HAS LEFT A
COMPLICATED PATTERN OF WINDS AND TEMPERATURES.
THE EVENTUAL EVOLUTION OF THE CONVECTION OVER THE PANHANDLES IS IN
QUESTION...ALTHOUGH IT IS PROBABLE THAT AT LEAST SOME OF THE WIND
FIELD WILL AFFECT OUR WESTERN COUNTIES A FEW HOURS EITHER SIDE OF
MIDNIGHT.
THE FORECAST HAS BEEN UPDATED FOR THE LATE EVENING/OVERNIGHT TO
REFLECT THE CURRENT TRENDS AND ESTIMATES OF FUTURE DEVELOPMENTS.
FURTHER UPDATES ARE PROBABLE OVERNIGHT.
PREV DISCUSSION... /ISSUED 410 PM CDT THU MAY 22 2014/
DISCUSSION...
WIDELY SCATTERED SHOWERS AND STORMS HAVE FORMED THIS
AFTERNOON ACROSS NORTHWEST AND NORTH CENTRAL OKLAHOMA
STORM ARE NEARLY STATIONARY WITH NEW DEVELOPMENT SOUTHEAST.
THIS WILL SUPPORT LOCALLY HEAVY RAINFALL WITH GUSTY WINDS
AND SMALL HAIL. MOST OF THIS ACTIVITY SHOULD DIMINISH THIS
EVENING...WHILE STORMS TO THE WEST MAKE SOME PROGRESS TO
THE EAST...ESPECIALLY NORTHWEST OKLAHOMA (HRRR).
THE MID/UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA IS STILL ON TRACK
TO MOVE SLOWLY EAST INTO NEW MEXICO BY SATURDAY. BY SUNDAY...A
SHORTWAVE TROUGH WILL MOVE ACROSS THE NORTHERN ROCKIES AND PLAINS
WHICH WILL HELP MOVE THE LOW EASTWARD. OVERALL...THE TIMING OF
RAIN AND COVERAGE OF STORMS IS DIFFICULT TO DETERMINE.
HOWEVER...WESTERN OKLAHOMA/NORTH TEXAS AND PERHAPS NORTHERN
OKLAHOMA WILL HAVE BETTER CHANCES FOR SCATTERED/WIDESPREAD SHOWERS
AND STORMS FROM FRIDAY INTO EARLY SUNDAY.
BETTER RAIN CHANCES WILL SPREAD INTO CENTRAL AND EASTERN OKLAHOMA
LATE SUNDAY INTO TUESDAY AS THE UPPER LOW MOVES FROM THE NORTHERN
TEXAS PANHANDLE INTO SOUTHERN OKLAHOMA. THE RISK FOR SEVERE STORMS
WILL REMAIN LOW THROUGH THE PERIOD...BUT SHOULD INCREASE SOME
SUNDAY INTO MONDAY AS THE OVERALL FLOW INCREASES ACROSS THE THE
FA. THE MAIN RISK WILL BE HEAVY RAINFALL...STRONG WIND GUSTS AND
SOME HAIL.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 82 66 85 65 / 30 30 40 30
HOBART OK 80 64 85 66 / 60 30 40 40
WICHITA FALLS TX 83 66 88 67 / 40 30 30 30
GAGE OK 78 61 82 64 / 60 30 50 60
PONCA CITY OK 84 65 82 66 / 30 50 40 30
DURANT OK 85 66 85 66 / 10 20 30 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1033 PM MDT THU MAY 22 2014
.UPDATE...
ISSUED AT 831 PM MDT THU MAY 22 2014
CONVECTION OVER NERN WY IS MOSTLY LOCATED NEAR THE MT BORDER...AND
IS DIMINISHING SO HAVE ADJUSTED POPS OVER THAT AREA ACCORDINGLY.
WILL KEEP LOW POPS IN THE FCST FOR THE SD PLAINS LATER TONIGHT
GIVEN ENERGY PROPAGATING NWD FROM NERN CO.
UPDATE ISSUED AT 523 PM MDT THU MAY 22 2014
RAISED POPS FOR NERN WY AND AROUND THE NRN PERIPHERY OF THE BLKHLS
FOR THIS EVE BASED ON RADAR OBSERVATIONS.
&&
.SHORT TERM...THIS EVENING THROUGH FRIDAY NIGHT
ISSUED AT 230 PM MDT THU MAY 22 2014
CURRENT SURFACE MAP PLACES HIGH PRESSURE ACROSS MINNESOTA...WITH
RETURN FLOW ACROSS THE HIGH PLAINS. UPPER LOW CONTINUES TO SPIN
ACROSS THE SOUTHWESTERN U.S. WITH RIDGE AXIS ACROSS THE NORTHERN
PLAINS. MLCAPE AROUND 1000 J/KG ACROSS NORTHEAST WYOMING/FAR
WESTERN SOUTH DAKOTA...HOWEVER WEAK CAP AND LACK OF FORCING HAS
KEPT THUNDERSTORM DEVELOPMENT ACROSS THE BLACK HILLS. MARGINAL
SHEAR FOR ROTATING UPDRAFTS. VERY SLOW STORM MOVEMENT. MAIN
THREAT THROUGH THIS EVENING WILL BE SMALL HAIL AND LOCALLY HEAVY
RAINFALL. LATEST RUN OF THE HRRR KEEPS SOME THUNDERSTORM ACTIVITY
ACROSS NORTHEAST WYOMING/WESTERN SOUTH DAKOTA UNTIL AFTER
MIDNIGHT.
SIMILAR SETUP ACROSS THE AREA FOR FRIDAY. MAIN DIFFERENCE WILL BE
STRONGER SHORTWAVE LIFTING NORTHWARD THROUGH WYOMING/WESTERN
NEBRASKA FRIDAY AFTERNOON. WITH STRONGER FORCING...MORE WIDESPREAD
THUNDERSTORM ACTIVITY FRIDAY AFTERNOON/EVENING. SHEAR A LITTLE
STRONGER...SO A FEW SEVERE HAIL STORMS POSSIBLE. SLOW MOVEMENT AND
HIGH PRECIPITABLE WATER WILL RESULT IN LOCALLY HEAVY RAINFALL.
&&
.LONG TERM...SATURDAY THROUGH THURSDAY
ISSUED AT 230 PM MDT THU MAY 22 2014
SOUTHWEST FLOW ALOFT REMAINS ACROSS THE REGION THIS WEEKEND...WITH
SEVERAL SHORTWAVE DISTURBANCES EJECTING OUT OF A PERSISTENT TROF/CUT
OFF LOW OVER THE WESTERN UNITED STATES. CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE SATURDAY AND SUNDAY...WITH THE POTENTIAL
FOR A FEW STRONG TO SEVERE STORMS EACH DAY. MEDIUM RANGE MODELS
CONTINUE TO SHOW SOMEWHAT GOOD AGREEMENT ON THE TRACK AND TIMING OF
UPPER LOW AS IT FINALLY MOVES FROM THE SOUTHWEST CONUS INTO THE
CENTRAL PLAINS LATE THROUGH THE HOLIDAY WEEKEND. CHANCES FOR PCPN
SHOULD DECREASE ACROSS MUCH OF THE AREA BY MONDAY AS THE LOW TRACKS
SOUTH AND EAST OF THE REGION. CHANCES FOR PCPN COULD INCREASE AGAIN
FOR THE SECOND HALF OF THE WEEK AS FLOW ALOFT RETURNS TO THE
SOUTHWEST. TEMPERATURES WILL BE A BIT ABOVE AVERAGE THROUGH THE
PERIOD...WITH HIGHS IN THE 70S AND LOWER 80S ON THE PLAINS...60S AND
LOWER 70S ACROSS THE BLACK HILLS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1031 PM MDT THU MAY 22 2014
ISOLATED HIGH BASED TSTMS POSSIBLE OVERNIGHT...MAINLY ON THE SD
PLAINS...WITH LCL MVFR VSBYS. OTHERWISE...VFR CONDITIONS WILL
CONTINUE OVERNIGHT. SCT TSTMS EXPECTED TO DEVELOP AGAIN FRIDAY
AFTN...SOME WITH HEAVY RAINFALL AND LIFR VSBYS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...JOHNSON
SHORT TERM...7
LONG TERM...13
AVIATION...JOHNSON
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
520 AM EDT FRI MAY 23 2014
.DISCUSSION...QUICK UPDATE FOR DEVELOPING CONVECTIVE COMPLEX OVER
SOUTH-CENTRAL KENTUCKY. THIS AREA OF CONVECTION IS ALONG A COLD
FRONT MOVING SLOWLY SOUTH INTO THE NORTHERN FORECAST AREA. AN UPPER
LEVEL JET IS HELPING TO PROVIDE LIFT ALONG THE FRONTAL BOUNDARY.
LATEST HRRR MODEL SHOWS THIS AREA OF SHOWERS/THUNDERSTORMS MOVING
ACROSS NORTHERN TENNESSEE...GENERALLY ALONG AND NORTH OF INTERSTATE
40. HAVE INCREASED POPS TO LIKELY THERE FOR THIS MORNING.
SPC MESOANALYSIS SHOWS HAIL CAPE GOOD ENOUGH FOR MARGINAL SEVERE
HAIL. ALSO DRY AIR IN THE MID-LEVELS AND WINDS ALOFT TO SUPPORT
ISOLATED WIND DAMAGE. UPDATED FORECAST WILL BE OUT SOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 89 62 85 60 / 30 20 10 10
KNOXVILLE MCGHEE TYSON AIRPORT, TN 84 57 82 56 / 20 10 0 0
OAK RIDGE, TN 85 56 82 54 / 20 10 0 0
TRI CITIES AIRPORT, TN 81 48 80 47 / 50 0 0 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
342 AM EDT FRI MAY 23 2014
.SHORT TERM (TODAY AND TONIGHT)...LATEST SURFACE ANALYSIS SHOWS
COLD FRONT ACROSS SOUTHERN KENTUCKY INTO SOUTHWEST VIRGINIA. VERY
SLOW SOUTHWARD MOVEMENT IS OCCURRING AND EXPECTED TODAY. HRRR MODEL
SHOWS CONVECTION DEVELOPING ACROSS THE PLATEAU EARLY THIS
MORNING...THEN MOVING ACROSS THE CENTRAL VALLEY...SO HAVE UP POPS
TO 30 PERCENT. THE FRONTAL BOUNDARY WILL BE ACROSS THE SOUTHERN
HALF OF THE AREA THIS AFTERNOON. FORECAST SOUNDINGS SHOW A
MODERATELY UNSTABLE AIRMASS ONCE AGAIN WITH CAPES OF 2500-3000
J/KG. ALSO FAVORABLE HAIL CAPES FOR LARGE HAIL AND POTENTIAL OF
MICROBURSTS DUE TO DRY MID-LEVELS. HAVE INCLUDED SEVERE THREAT
WITHIN THE HWO AND WILL INCLUDE IN GRAPHICAST.
FRONTAL BOUNDARY MOVES SOUTH OF THE AREA FOR TONIGHT WITH DRIER AIR
AND END TO CONVECTION.
.LONG TERM (SATURDAY THROUGH THURSDAY)...THE FORECAST AREA ENJOYS A
PERIOD OF RIDGING TO START THE LONG TERM PERIOD WITH JUST ENOUGH
MOISTURE AND THE NEEDED INSTABILITY FOR JUST THE SLIGHTEST CHANCE OF
A SHOWER OR THUNDERSTORM ACROSS SOUTHEAST TENNESSEE AND SOUTHWEST
NORTH CAROLINA ON SUNDAY AFTERNOON. BY MONDAY THE RIDGE BEGINS TO
LOSE INFLUENCE AS AN UPPER LEVEL TROUGH MAKES A MOVE INTO THE
EASTERN LAKES AND NEW ENGLAND AND BY MID WEEK BOTH THE ECMWF AND THE
GFS INDICATE AMPLIFICATION OF THIS ACROSS THE NORTHEASTERN QUARTER
OF THE NATION. IN THIS CONFIGURATION PIECES OF UPPER LEVEL ENERGY
WILL DROP THROUGH THE BACK SIDE OF THE TROUGH ENHANCING LIFT FOR
CONVECTIVE EPISODES IN THE VICINITY OF SYNOPTIC FRONTAL BOUNDARY
THAT WILL BE DROPPING SOUTH INTO THE CENTRAL APPALACHIANS BY
WEDNESDAY. MAINTAINED CHANCE POPS FOR CONVECTION TUESDAY THROUGH
THURSDAY IN WHAT APPEARS TO BE A VERY WARM AND HUMID...SUMMER LIKE
PATTERN NEXT WEEK. STAYED WITH THE ABOVE NORMAL TEMPERATURES THROUGH
MUCH OF THE LONG TERM.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 89 62 85 60 / 30 20 10 10
KNOXVILLE MCGHEE TYSON AIRPORT, TN 84 57 82 56 / 20 10 0 0
OAK RIDGE, TN 85 56 82 54 / 20 10 0 0
TRI CITIES AIRPORT, TN 81 48 80 47 / 20 0 0 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1153 PM CDT THU MAY 22 2014
.AVIATION UPDATE...FOR 06Z TAF PACKAGE...
BR CONCERNS WILL BE PRESENT AT ALL TERMINAL THIS MORNING AS
YESTERDAYS STORMS HAVE MOISTENED THE LOW LEVEL ATMOSPHERE. TEMPO
IFR CONDITIONS ARE POSSIBLE SPORADICALLY AT KCSV AND MVFR AT KBNA
AND KCSV. VCTS WILL BE RETURNING BY MIDDLE AFTERNOON AGAIN
TOMORROW.
&&
.PREV DISCUSSION... /ISSUED 735 PM CDT THU MAY 22 2014/
UPDATE...
HAVE REMOVED REMAINDER OF COUNTIES FROM SEVERE THUNDERSTORM WATCH
AS ALL CONVECTION HAS EXITED THE AREA. RADAR INDICATES OUTFLOW
BOUNDARY/EFFECTIVE COLD FRONT EXTENDS FROM NEAR DOVER TO JUST
NORTH OF NASHVILLE TO NEAR SPENCER...AND VISIBLE SATELLITE IMAGERY
SHOWS TOWERING CUMULUS CONTINUES ALONG BOUNDARY FROM CLARKSVILLE
WESTWARD INTO WESTERN KY AND MO. THUS SOME ADDITIONAL SHOWERS AND
STORMS COULD YET STILL FORM THIS EVENING AND MOVE ACROSS THE
NORTHERN HALF OF THE CWA...AS LATEST HRRR RUNS SUGGEST.
INDEED...LATEST RADAR MOSAIC IMAGERY SHOWS SHOWERS DEVELOPING IN
SE MO ATTM. HAVE ADJUSTED POPS FOR THE REST OF TONIGHT TO SHOW A
SLIGHT CHANCE ALONG AND NORTH OF A ERIN TO ALTAMONT LINE. WILL
ALSO MENTION PATCHY FOG IN SAME AREA DUE TO THE MOIST LOW
LEVELS...BUT FOG WILL BE MOST LIKELY ON THE NORTHERN PLATEAU WHERE
RAIN COOLED AIR HAS SATURATED THE BL. ALSO ADJUSTED TEMPS AND LOWS
FOR TONIGHT BASED ON LATEST OBS. REST OF FORECAST LOOKS TO BE ON
TRACK.
SHAMBURGER
PREV DISCUSSION... /ISSUED 641 PM CDT THU MAY 22 2014/
UPDATE...
ONE LONE CELL EXISTS JUST NORTH OF THE DOVER AREA BUT IT APPEARS
TO BE WEAKENING. ELSEWHERE...STILL A FEW RESIDUAL TSTMS ACROSS THE
PLATEAU BUT THEY TOO HAVE WEAKENED. INSTABILITY PARAMETERS REMAIN
ELEVATED BUT OVERALL FORCING LEVELS HAVE LESSENED.
FOR THE UPDATE...WILL REMOVE THE WATCH FROM AREAS WEST OF THE
PLATEAU BUT WILL ALLOW THE WATCH ACROSS THE PLATEAU TO CONTINUE
FOR A LITTLE LONGER. WILL ALSO MAKE ADJUSTMENTS TO THE SKY GRIDS
AND WILL LOWER POPS. UPDATE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 630 PM CDT THU MAY 22 2014/
AVIATION 00Z DISCUSSION...
CONVECTION ASSOCIATED WITH THE COLD FRONT WILL EFFECT PRIMARILY
THE CSV AREA THROUGH 03Z. ELSEWHERE...CHANCES FOR TSTM REDEVELOPMENT
ARE MUCH LOWER. BUT...A SEVERE TSTM WATCH DOES REMAIN IN EFFECT
FOR THE TERMINAL AREAS UNTIL 10 PM CDT. OTW...SOME LOWER CIGS ARE
EXPECTED LATER TONIGHT ALONG WITH SOME FOG TOWARD 12Z. PARTIAL
CLEARING WILL TAKE PLACE AFT 14Z OR SO. ISOL CONVECTION WILL THEN
BE POSSIBLE AFT 18Z.
PREV DISCUSSION... /ISSUED 321 PM CDT THU MAY 22 2014/
DISCUSSION...
FRONTAL BOUNDARY RESIDES ACROSS CENTRAL KY IN A W-E FASHION. IT IS
ACROSS THIS AREA WHERE THE ADDED FORCING HAS BROKEN THROUGH THE
CAP. THIS TREND SHOULD CONTINUE AND THE MID LEVEL FLOW SUGGESTS A
SOUTHEASTWARD MOVEMENT. MAY LIKELY INCLUDE A PRE 1ST PERIOD ZONE
GROUP AS THE EXPECTED CONVECTION WILL END EARLY THIS EVENING
ACROSS NW ZONES. ACROSS NORTHEASTERN AREAS...THE CONVECTION COULD
CONTINUE INTO THE EVENING. AS FOR THE SEVERE POTENTIAL...MUCH OF
THE MID STATE IS STILL UNDER A SLIGHT RISK...AND THAT HAS NOW BEEN
UPGRADED TO A SEVERE TSTM WATCH FOR MUCH OF THE NORTHERN TWO
THIRDS OF THE MID STATE UNTIL 10 PM. DEW POINTS HAVE SLOWLY RISEN
DURING THE DAY SO THE INSTABILITY LEVELS ARE ON THE INCREASE.
SOUTH OF THE BOUNDARY HOWEVER...WE ARE PICKING UP SOME SUBSIDENCE
IN THE LOWER LEVELS AND ITS FURTHER NORTH...NEAR THE FRONT...WHERE
THE FORCING RESIDES. CAPES ARE QUITE IMPRESSIVE THIS AFTERNOON AND
TSTMS WITH LARGE HAIL AND OR HIGH WIND GUSTS WILL BE POSSIBLE.
FOR TONIGHT...POPS WILL BE KEPT WITHIN THE CHANCE CATEGORY WITH
NO POPS FAR SOUTHWEST.
ON FRIDAY...THE COLD FRONT WILL BE POSITIONED ACROSS OUR SOUTHERN
COUNTIES. CAP WILL AGAIN DIMINISH TOWARD 18Z WITH ENHANCED CAPE
VALUES...ESPECIALLY NEAR THE FRONT. WILL AGAIN INCLUDE A SLIGHT
CHANCE OF SHOWERS AND TSTMS.
ON SATURDAY...SFC HIGH TO OUR NORTH WILL PREVAIL WITH A NE SFC FLOW.
UPPER RIDGE WILL BE ATTEMPTING TO DEVELOP TO OUR WEST. SOME LOWER
LEVEL MOISTURE ENHANCEMENT WILL ATTEMPT TO MAKE A RUN AT US AS WELL.
BUT OVERALL INSTABILITY PARAMETERS LOOK TOO LOW AT THIS TIME TO
SUPPORT POPS.
FOR THE NEAR TERM TEMPS...LOW LEVEL MOISTURE ON THE TIME HEIGHT
PROFILES TENDS TO SUPPORT GOING A DEGREE OR TWO ABOVE MINS.
OTW...GUIDANCE FOR HIGHS LOOKS TO BE ON TRACK.
IN THE EXTENDED FCST...A SMALL SCALE BUT APPARENT UPPER RIDGE WILL
MOVE ACROSS OUR AREA MONDAY AND TUESDAY. GFS HINTS TOWARD A FEW
DEVELOPMENTAL BOUNDARIES UNDERNEATH THE RIDGE. AFTERNOON CAPES ARE
IN PLACE EACH DAY WITH CAPS DIMINISHING TOWARD 18Z. UPPER LEVEL AND
MOISTURE COMPONENTS NOT IN SUPPORT OF ANY WELL ORGANIZED SYSTEMS.
THEREFORE...THIS LOOKS LIKE A MORE TYPICAL SUMMERTIME PATTERN WITH
WEAK FEATURES BUT A SUSTAINED UNSTABLE PATTERN EACH AFTERNOON. WILL
OPT TO CONTINUE WITH THE LOW POP CHANCES.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TB12
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
508 AM MST FRI MAY 23 2014
.UPDATE...TO AVIATION AND FIRE WEATHER DISCUSSIONS...
&&
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL CONTINUE TO MOVING EAST ACROSS THE DESERT
SOUTHWEST BRINGING A SLIGHT CHANCE OF THUNDERSTORMS TO THE AREA
TODAY. STORM CHANCES WILL BE LIMITED MAINLY TO THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON SATURDAY. ABOVE NORMAL TEMPERATURES WILL
RETURN TO THE REGION EARLY NEXT WEEK AS HIGH PRESSURE BECOMES
REESTABLISHED TO OUR SOUTH.
&&
.DISCUSSION...
LATEST WV IMAGERY SHOWS THE PERSISTENT CUTOFF LOW SPINNING ACROSS
THE DESERT SOUTHWEST. SHORT-TERM MODELS ARE IN GOOD AGREEMENT THAT
THE MID-TROPOSPHERIC LOW WILL CONTINUE DRIFTING EASTWARD INTO
WESTERN AZ TODAY. ALTHOUGH VORTICITY FORCED ASCENT REMAINS
RELATIVELY STRONG AND ORGANIZED ACROSS AZ...MOISTURE WILL BE A
LIMITING FACTOR ACROSS THE FORECAST AREA WITH THE DEEPEST MOISTURE
CLEARLY LOCATED ALONG THE EASTERN FLANK OF THE LOW AND EAST OF THE
REGION. NEVERTHELESS...A PERSISTENCE FORECAST ALONG WITH SUPPORT
FROM THE LOCAL WRFS AND HRRR SUGGEST THAT ISOLATED THUNDERSTORMS ARE
POSSIBLE TODAY IN THE VICINITY OF THE MID-LEVEL COLD POOL...MAINLY
ACROSS THE LOWER DESERTS OF SOUTHWESTERN AZ. ANY STORMS THAT DO
DEVELOP WILL NOT CONTAIN MUCH RAIN. INSTEAD THE GREATER THREAT
REMAINS DRY LIGHTNING ALONG WITH LOCALLY GUSTY WINDS AND LOCALIZED
BLOWING DUST.
SUITE OF MODEL GUIDANCE INDICATES THAT THE UPPER LOW WILL CONTINUE
SLIDING EASTWARD THIS WEEKEND. HOWEVER...MODELS DIFFER ON THE
EVOLUTION OF SEVERAL SMALLER VORTICES EMBEDDED WITHIN THE LARGER
LOW. CONSEQUENTLY...DETERMINING THE EXACT THE PLACEMENT AND TIMING
OF PRECIPITATION WILL BE DIFFICULT...THOUGH THE CONSENSUS IS THAT
CONVECTION WILL LARGELY REMAIN CONFINED TO THE
CLIMATOLOGICALLY-FAVORED HIGHER TERRAIN NORTH AND EAST OF PHOENIX.
POPS ARE HIGHEST IN THESE AREAS...THOUGH ISOLATED THUNDERSTORMS IN
THE PHOENIX AREA CANNOT TOTALLY BE RULED OUT.
IN THE WAKE OF THE LOW EARLY NEXT WEEK...DRY SOUTHWESTERLY FLOW WILL
DEVELOP BETWEEN AN AREA OF LOW PRESSURE ACROSS THE PACIFIC NORTHWEST
AND A RIDGE ACROSS NORTHERN MEXICO. AFTER A PERIOD OF BELOW NORMAL
TEMPERATURES THROUGH SUNDAY...ABOVE NORMAL TEMPERATURES WILL RETURN
MONDAY AND WILL CONTINUE THROUGH NEXT WEEK. HOWEVER...LATEST
GUIDANCE INDICATES THAT TEMPERATURES WILL REMAIN WELL BELOW RECORDS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL... AND SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
UPPER LEVEL LOW WILL LINGER OVER THE REGION AND SLOWLY SHIFT EAST
ACROSS SE CALIFORNIA AND INTO ARIZONA TODAY. WINDS EXPECTED
TO REMAIN LIGHT AND DIURNALLY DRIVEN...GENERALLY AROUND 10KT THROUGH
FRIDAY AFTERNOON. SUFFICIENT MOISTURE AND INSTABILITY WILL KEEP
SLIGHT CHANCE OF THUNDERSTORMS ACROSS THE REGION DURING THE DAY AND
INTO THE EVENING HOURS...THE STRONGEST STORMS IF THEY FORM WILL HAVE
THE POTENTIAL TO PRODUCE OUTFLOW WIND GUSTS TO 40 KT...AND AREAS OF
BLOWING DUST/REDUCED VSBYS. THE BEST CORRIDOR FOR MIDDAY
INITIATION/DEVELOPMENT PER HI-RES MODELS LOOKS TO BE ACROSS
SOUTHWESTERN ARIZONA...WHERE ACTIVITY AND/OR OUTFLOWS COULD BE IN
THE VICINITY OF BLYTHE NEAR 23/1800Z. ADDITIONAL ACTIVITY ACROSS FAR
WESTERN MARICOPA COUNTY COULD SEND OUTFLOWS INTO THE PHOENIX METRO
WITH REDUCED VSBYS DUE TO DUST DURING THE AFTERNOON/EVE. WITH SOME
UNCERTAINTY AS TO TIMING ANY OUTFLOW WINDS INTO THE PHX METRO...LEFT
MENTION OUT OF THE 12Z TAFS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE OVER
THE NORTHEASTERN/EASTERN ARIZONA HIGH TERRAIN SUNDAY WHILE THE
ALREADY SLOW MOVING LOW MAKES A SLOWER EXIT TO THE EAST. LATEST
FORECAST RUNS HAVE SLOWED THE EXIT OF THIS WEEKEND`S LOW PRESSURE
SYSTEM...WITH RESIDUAL TROUGH HEIGHTS LINGERING OVER THE FOUR
CORNERS INTO MONDAY. WETTING RAINS FROM STORM ACTIVITY ON SUNDAY NOT
LIKELY...WITH STRONG GUSTY OUTFLOW WINDS AND LIGHTNING REMAINING THE
PRIMARY THREATS WITH ANY STORM DEVELOPMENT. STORM CHANCES A GREATLY
REDUCED FOR MONDAY AS THE BEST MOISTURE AND INSTABILITY PROFILES
CLEAR EAST OF THE AREA...BUT SOME ADDITIONAL COOLING AND BREEZINESS
COULD BE GENERATED MONDAY WITH A SLOWER LOW EXIT. ONCE THE UPPER LOW
EXITS THE REGION...A WARMING AND DRYING TREND WILL COMMENCE
RETURNING DAYTIME TEMPS AT OR ABOVE NORMAL BY MONDAY AND CONTINUING
THROUGH MIDWEEK.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....NOLTE/MEYERS
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1023 AM EDT FRI MAY 23 2014
.SYNOPSIS...
LOW PRESSURE WILL BRING A FEW ROUNDS OF SHOWERS AND ISOLATED
THUNDERSTORMS THROUGH SUNDAY...BUT CERTAINLY NOT EXPECTING A
WASHOUT. TURNING MILDER SUNDAY THEN WARM AND DRY CONDITIONS
EXPECTED FOR MEMORIAL DAY. A WEAK FRONT MAY BRING SCATTERED
SHOWERS TUESDAY INTO EARLY WEDNESDAY ALONG WITH COOLER
TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
***SHOWERS AND EMBEDDED THUNDERSTORMS ACROSS WESTERN MA/NORTHERN CT
WITH LOCALLY HEAVY RAINFALL EXPECTED THIS AFTERNOON AND EVENING***
1015 AM UPDATE...
ALL IS QUIET WITH A JUST A FEW SHOWERS MOVING NE FROM S NH. THE
MAIN CONCERN FOR LATER THIS AFTERNOON INTO THE EVENING IS
POTENTIAL FOR CONVECTION AS STRONG MID LEVEL SHORTWAVE DIVES SE
FROM THE GT LAKES. MODELS INDICATE SOME WEAK INSTABILITY WITH
SBCAPES AROUND 500 J/KG IN THE WEST ALONG WITH DECENT MID LEVEL
COOLING AND QG FORCING SO EXPECT SCT TO NUMEROUS SHOWERS AND
EMBEDDED TSTMS TO DEVELOP. MAIN FOCUS FOR CONVECTION WILL BE IN
WESTERN NEW ENG WHERE BEST INSTABILITY COMBINED WITH LOW LEVEL
CONVERGENCE ALONG A WEAK INVERTED TROF. HRRR IS TARGETING THE
WEST MOSTLY AFTER 20Z. WIND FIELDS ARE QUITE WEAK LATER THIS
AFTERNOON SO SEVERE THREAT IS LOW...BUT HEAVY RAINFALL WILL BE A
CONCERN AS STORMS WILL LIKELY BE SLOW MOVING.
MEANWHILE...ACROSS EASTERN NEW ENGLAND SCATTERED SHOWERS MAY
AFFECT THE REGION AT TIMES. HOWEVER...GIVEN MARINE LAYER/LESS
INSTABILITY NOT EXPECTING THUNDER OR THE ACTIVITY TO BE AS
WIDESPREAD.
RAISED TEMPS A FEW DEGREES WITH HIGHS MOSTLY IN THE 60S...EXCEPT
UPPER 50S ALONG THE IMMEDIATE E COAST OF MA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT...
SHOWERS AND EMBEDDED THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL WILL
CONTINUE ACROSS WESTERN NEW ENGLAND DURING THE EVENING HOURS IN
ASSOCIATION WITH THE SHORTWAVE. ACROSS EASTERN SECTIONS...JUST
EXPECTED SOME SCATTERED SHOWERS AS INSTABILITY/FORCING WILL BE LESS.
ACTIVITY SHOULD DIMINISH IN ALL AREAS AFTER MIDNIGHT...BUT SOME
MORE LOW CLOUDS AND PATCHY FOG WILL PROBABLY DEVELOP.
SATURDAY...
ANOTHER SHORTWAVE WILL LIKELY TRIGGER SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SAT AFTERNOON...MAINLY ACROSS WESTERN NEW ENGLAND
WHERE BETTER INSTABILITY IS LOCATED. SHORTWAVE DOES NOT LOOK AS
POTENT AS TODAY/S...SO NOT EXPECTING ACTIVITY TO BE AS WIDESPREAD.
ACROSS EASTERN NEW ENGLAND...PERHAPS A FEW SHOWERS BUT NOT MUCH MORE
THAN THAT WITH LIMITED INSTABILITY. HIGH TEMPS WILL MAINLY BE IN
THE 60S...WITH THE WARMEST READINGS IN THE LOWER CONNECTICUT RIVER
VALLEY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGHLIGHTS...
- WEEKEND CHANCES OF SHOWERS/THUNDERSTORMS ACROSS THE INTERIOR
- NICE AND MILD FOR MEMORIAL DAY
- ANOTHER SHOT OF WET WEATHER FOR TUESDAY AND WEDNESDAY
OVERVIEW AND MODEL PREFERENCES...
00Z MODEL GUIDANCE SUITE CONTINUES TO SHOW A GRADUAL TREND AWAY
FROM EASTERN RIDGE BUILDING THAT...THE TREND FROM EARLIER IN THE
WEEK. THIS IS CONSISTENT WITH SEVERAL OF THE ENSEMBLES SUGGESTING
A POSITIVE NAO...ALTHOUGH STILL WITH CONSIDERABLE SPREAD. GIVEN
THE RECENT SHIFT IN LONG TERM PATTERN AND UNCERTAINTY WITH SEVERAL
SMALLER SCALE WAVES/RIDGING IN A COOLER/TROUGH DRIVEN PATTERN...A
BLEND OF ENSEMBLES WITH THE PREVIOUS FORECAST SEEMS APPROPRIATE
FOR THE LONG TERM.
UNSTABLE...AS NOTED BY THE PREVIOUS FORECASTER...APPEARS TO BE
THE BEST WAY TO DEFINE THE LONG TERM. NOT NECESSARILY IN THE
ATMOSPHERIC STABILITY SENSE /ALTHOUGH THAT WILL BE A PLAYER AS
WELL AT TIMES/...BUT IN THE SENSE THAT THERE IS A LOT OF DAY-TO-
DAY UNCERTAINTY GIVEN WE ARE DEALING WITH A WEAK LONGWAVE TROF AND
SEVERAL ENERGY WAVES MOVING THROUGH IT. WITH LONGWAVE TROF IN
PLACE...THE WARM FRONT AHEAD OF BUILDING CENTRAL CONUS RIDGE MAY
ACTUALLY STALL...SOUTHWEST OR AT LEAST IN THE VICINITY OF SRN NEW
ENGLAND. THIS WAS THE WARM FRONT/RIDGE THAT WAS ORIGINALLY
SUGGESTING AN ABOVE NORMAL TEMPERATURE PERIOD. HOWEVER...NOW GIVEN
THAT THIS LOOKS TO REMAIN W OF NEW ENGLAND...A NEAR TO POTENTIALLY
EVEN BELOW NORMAL PATTERN LOOKS MORE FAVORABLE...WITH THE
POSSIBILITY OF PERIODIC WET WX WITH SHORTWAVE ENERGY OR SOME
MODEST DIURNAL INSTABILITY. THESE OVERALL TRENDS LOOK TO HOLD AT
LEAST THROUGH MID WEEK...BUT THE UNCERTAINTY SNOWBALLS TOWARD THE
END OF THE PERIOD.
DETAILS...
SAT NIGHT INTO SUN...
WITH POTENTIAL FOR DIURNAL/SHORTWAVE DRIVEN CONVECTION DURING THE
AFTERNOON AND EVENING...SOME SHOWERS/TSTORMS MAY LINGER INTO THE
EARLY OVERNIGHT HOURS UNTIL INSTABILITY IS LOSS WITH SETTING SUN.
THE CORE OF THE UPPER LVL SHORTWAVE MOVES THROUGH DURING THE EARLY
MORNING HOURS...SO WILL ACTUALLY HOLD ON TO POPS A BIT LONGER INTO
THE OVERNIGHT HOURS. BY SUN...STILL NOTE MODESTLY STEEP LAPSE
RATES AROUND 6.0-7.0C/KM BUT LESS OF A MECHANISM FOR LIFT.
THEREFORE...STILL LOOKS LIKE AFTERNOON SHOWERS/T-STORMS ARE
POSSIBLE...BUT SPATIAL EXTENT IS LIKELY TO BE LESS THAN THAT OF
SATURDAY. TEMPS NEAR NORMAL ARE LIKELY GIVEN +10C AT H85 AND
MIXING SHOULD AT LEAST MAKE A RUN AT NORMAL VALUES.
SUN NIGHT INTO MON...
AGREE WITH PREVIOUS FORECASTER THAT THIS PERIOD LOOKS TO BE THE
MOST LIKELY PERIOD FOR DRY WX THROUGH MID WEEK. MID LVL RIDGE WILL
EJECT OUT OF THE CENTRAL CONUS AS ANOTHER SHORTWAVE TROF DIVES
INTO THE NORTHEAST FROM NRN QC...FLATTENING IT AS IT APPROACHES.
THEREFORE...WITH SOME SUBSIDENCE STILL EVIDENT IN THE COLUMN
THROUGH THE PERIOD /AFTER ANY SUN EVENING SHOWERS/STORMS DIMINISH/
LOOK FOR MAINLY DRY FORECAST PERIOD INTO LATE MON.
THEREFORE...WILL CONTINUE THIS PATTERN WITH THIS OVERNIGHT
FORECAST UPDATE. H85 TEMPS AROUND +12 SUGGEST THE POSSIBILITY OF
TEMPS IN THE UPPER 70S TO AROUND 80...EVEN NEAR SHORE AS STRONG W
COMPONENT TO THE WIND IS LIKELY TO MITIGATE SEA BREEZE THREAT.
TUE AND WED...
AS MENTIONED BEFORE...THERE IS A LOT OF VARIABILITY BETWEEN
SOLUTIONS NOT JUST IN DETERMINISTIC GUIDANCE...BUT ENSEMBLES AS
WELL...BEGINNING THIS PERIOD. ALTHOUGH THERE IS NOW THE SUGGESTION
OF REINFORCEMENT OF THE TROF ACROSS THE NORTHEAST...KEEPING THE
STRONG RIDGING W OF THE GREAT LAKES...EXACTLY HOW THIS PLAYS OUT
IN SENSIBLE WX REMAINS MORE UNCERTAIN. GFS AND SOME MODELS
GENERATE STRONG LOW PRES WHICH MAY SLIDE S OF THE
REGION...DELIVERING A PROLONGED PERIOD OF WET WX...WHILE THE ECMWF
AND OTHER ENSEMBLES LEAN MORE ON A SERIES OF SHORTWAVES
CULMINATING IN COLD FRONTAL PASSAGE. IN ANY CASE...WITH PWAT
VALUES AVERAGING AROUND 1.0 INCHES...COOLING UPPER LVL TEMPS AND
AT LEAST A COUPLE OF SOURCES FOR LIFT...ANOTHER ROUND OF
POTENTIALLY WET/UNSETTLED WX IS EXPECTED. WILL NEED TO MONITOR THE
SHORTWAVE PLAYERS AS THEY MIGRATE THROUGH CANADA THROUGH THE
WEEKEND TO BETTER REFINE THE EXACT TIMING/LOCATIONS OF POTENTIAL
PRECIP.
LATE NEXT WEEK...
WITH CONUS RIDGING ATTEMPTING A SLIDE TO THE EAST THROUGH THIS
PERIOD EXACT DETAILS WILL DEPEND STRONGLY ON HOW QUICKLY THE
PERSISTENT TROF ACROSS THE NE HOLDS IN. IN ANY CASE...A PERIOD OF
DRY WX MAY FOLLOW THE UNSETTLED MID-WEEK TIMEFRAME THANKS TO
ANOTHER SHORTWAVE RIDGE EJECTION. WILL TREND TOWARD LOWER TO NIL
POPS...BUT EXACT TEMPERATURES WILL BE DEPENDENT ON TO WHAT EXTENT
THE TROF REMAINS OR THE WARM FRONT ASSOCIATED WITH THE RIDGE TO
THE W MOVES THROUGH. SO TEMPERATURES ARE LOW CONFIDENCE AT THIS
TIME.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY AFTERNOON/...LOW CONFIDENCE.
ANOTHER DAY SIMILAR TO YESTERDAY WHERE LOW CLOUDS AND SOME PATCHY
FOG LINGER INTO THE MID MORNING HOURS FOR SOME...BUT LONGER FOR
OTHERS. IFR SITES SHOULD LIFT TO AT LEAST MVFR BY MID-LATE
MORNING...AND THEN EXPECT A COMPLEX MIX OF MVFR/VFR BEFORE THINGS
LOWER AGAIN OVERNIGHT TONIGHT TO MVFR/IFR. WHILE THIS TREND IS
GENERALLY EXPECTED...THE LOW CONFIDENCE FORECAST IS MAINLY DUE TO
TIMING.
THIS AFTERNOON AND EVENING...MORE WIDESPREAD SHOWERS AND EMBEDDED
THUNDERSTORMS ARE POSSIBLE ESPECIALLY WEST OF A IJD-ORH-AFN LINE.
WINDS ARE EXPECTED TO SHIFT MORE TO THE N EARLY SAT
MORNING...WHICH MAY HELP TO LIFT CONDITIONS OUT OF MVFR/IFR AND TO
MORE VFR/MVFR INTO THE DAY ON SAT.
KBOS TAF...MODERATE CONFIDENCE. TRENDS IN TAF ARE GENERALLY
EXPECTED BUT CONFIDENCE IN TIMING IS THE MAIN ISSUE.
KBDL TAF...LOW CONFIDENCE IN TAF AND TIMING. IFR CONDITIONS EARLY
THIS MORNING MAY IMPROVE TO MVFR TO EVEN VFR THRESHOLDS BY THIS
AFTERNOON. PERIODS OF SHOWERS AND PERHAPS A FEW THUNDERSTORMS ARE
ANTICIPATED LATER TODAY INTO THIS EVENING.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SAT NIGHT INTO SUN...MODERATE CONFIDENCE.
SAT NIGHT FOG POSSIBLE WITH LOCALIZED MVFR/IFR CONDITIONS WITH VFR
DOMINATING DURING THE DAY ON SUN OUTSIDE OF AFTERNOON SHOWERS AND
THUNDERSTORMS. WINDS SHIFT FROM THE N-NE TO THE S EARLY IN THE DAY
ON SUN.
MON AND MON NIGHT...HIGH CONFIDENCE.
WINDS SHIFT TO THE W...WITH GUSTS AROUND 25 KT POSSIBLE DURING THE
AFTERNOON. LOWER CHANCES IN AFTERNOON SHOWERS AND
THUNDERSTORMS...BUT NON-ZERO. MAINLY VFR OUTSIDE OF ANY LOCALIZED
MVFR/IFR IN SHOWERS/STORMS.
TUE...LOW CONFIDENCE.
EXPECT MORE WIDESPREAD SHOWERS...AND MAYBE A THUNDERSTORM DURING
THE DAY ON TUESDAY. MIX OF MVFR/IFR POSSIBLE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY AFTERNOON/...HIGH CONFIDENCE.
WINDS/SEAS WILL REMAIN BELOW SCA LEVELS TODAY. LOW PRESSURE WILL
PASS SOUTH OF THE WATERS LATER TONIGHT AND SATURDAY. SEAS MAY BUILD
TO BETWEEN 3 AND 5 FEET WITH NORTHEAST WIND GUSTS OF 20 TO 25 KNOTS
LATE TONIGHT INTO SATURDAY ACROSS THE SOUTHERN WATERS. SINCE ITS A
MARGINAL LATE 2ND AND 3RD PERIOD EVENT...WILL DEFER POSSIBLE SCA
HEADLINES TO THE NEXT SHIFT.
THE OTHER MAIN CONCERN ON THE WATERS IS FOR AREAS OF FOG WHICH COULD
BE LOCALLY DENSE AT TIMES...PARTICULARLY DURING THE LATE NIGHT/EARLY
MORNING HOURS.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT INTO SUNDAY...MODERATE CONFIDENCE.
WINDS SHIFT FROM PREDOMINANTLY N-NE TO THE S-SW DURING THE DAY ON
SUN...BUT REMAIN BELOW 25 KT. SEAS TOO REMAIN BELOW 5 FT THROUGH
THE PERIOD. SOME LOW VSBYS POSSIBLE ESPECIALLY SUN MORNING IN FOG.
MONDAY...MODERATE CONFIDENCE.
WINDS SHIFT TO THE W AND STRENGTHEN ON MON...WITH SOME GUSTS
AROUND 25 KT...ESPECIALLY NEAR THE SHORE DURING THE AFTERNOON.
WITH STRONGER WINDS...EXPECT SEAS TO BUILD ESPECIALLY ON THE OCEAN
WATERS...POSSIBLY REACHING 5 FT BY LATE IN THE DAY.
TUESDAY...LOW CONFIDENCE.
SOME RAIN POSSIBLE WITH A FRONTAL PASSAGE WITH WINDS SHIFTING FROM
THE W...TO THE N. ALTHOUGH THE CONFIDENCE IN WINDS AROUND 25 KT IS
LOW...SOME LINGERING SWELLS OF 5+ FT MAY MEAN SMALL CRAFT
ADVISORIES REMAIN ACROSS SOME OF THE WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...KJC/FRANK
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
941 AM CDT Fri May 23 2014
...Update to synopsis...
.SYNOPSIS...
ISSUED AT 941 AM CDT FRI MAY 23 2014
The 23.12Z 250/500-hPa map showed a large mid to upper level disturbance
located cross western Arizona. 250-hPa 50 kt southwesterly flow continued
downstream of this feature across western Kansas. The KDDC raob was
fairly moist with a pwat of 1.13" - still between 75th percentile/+2SD.
At the sfc, KDDC WSR- 88D was indicating some showers/iso tstorms around
the region.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI MAY 23 2014
ISENTROPIC LIFT WILL REDEVELOP LATER THIS MORNING IN A MOIST
ATMOSPHERE WITH PRECIPITABLE WATER VALUES IN EXCESS OF 1 INCH AS
FAR WEST AS EASTERN COLORADO. THIS SHOULD ALLOW SHOWER AND
THUNDERSTORMS TO DEVELOP EASILY WITH INCREASING LIFT. AS THE
THUNDERSTORMS HAVE DECAYED, WE`VE FOLLOWED THE HRRR TRENDS FOR
CONVECTION THROUGH AROUND 12-14 UTC, BEFORE SIGNIFICANTLY RAMPING UP
CHANCES TOWARD 18 UTC ONCE AGAIN. EXTENSIVE CLOUDS AND OCCASIONAL
PRECIPITATION ESPECIALLY BY THIS AFTERNOON WILL RELEGATE
TEMPERATURES HOMOGENEOUSLY IN THE 70S ACROSS MOST OF THE FORECAST
AREA. CAPE VALUES WILL BE NOT AS HIGH AS ON THURSDAY AND SEVERE
THREAT IS MINIMAL AS A RESULT. SHOWERS AND THUNDERSTORMS SHOULD
PERSIST INTO THE EVENING HOURS AND FORECAST PRECIPITATION CHANCES
WERE MAXIMIZED AROUND 0 UTC. AS A RESULT OF THE RELATIVELY HUMID
CONDITIONS, LOWS TONIGHT WILL LIKELY NOT FALL BELOW 60 DEGREES IN
MOST AREAS WITH FOG BECOMING POSSIBLE TOWARD EARLY MORNING
SATURDAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 418 AM CDT FRI MAY 23 2014
THE MEDIUM RANGE MODELS CONTINUE TO SHOW AN UPPER LEVEL LOW PRESSURE
SYSTEM MOVING SLOWLY FROM THE DESERT SOUTHWEST ON SATURDAY INTO THE
CENTRAL AND SOUTHERN HIGH PLAINS BY MEMORIAL DAY. AS THE UPPER LOW
APPROACHES THE REGION, LOW LEVEL SOUTHERLY FLOW WILL CONTINUE TO
PUMP GULF MOISTURE INTO THE CENTRAL HIGH PLAINS. WEAK DISTURBANCES
ROTATING AROUND THE UPPER LOW AND EJECTING OUT OVER THE CENTRAL
PLAINS WILL BRING THUNDERSTORM CHANCES TO WESTERN AND CENTRAL KANSAS
PRETTY MUCH EVERY DAY THROUGH TUESDAY. WIND FLOW WILL NOT BE OVERLY
STRONG OVER WESTERN KANSAS THE NEXT FEW DAYS BUT MODEL SOUNDINGS
SHOW SOME DIRECTIONAL SHEAR AND THERE SHOULD BE ENOUGH INSTABILITY
FOR AT LEAST A SMALL THREAT OF SEVERE WEATHER ON SATURDAY AFTERNOON
AND EVENING.
THE MODELS BEGIN TO DIVERGE A LITTLE ON HOW QUICKLY THE UPPER LOW
CONTINUES EAST OUT OF THE HIGH PLAINS TOWARD THE MIDDLE PART OF THE
WEEK BUT CONTINUE TO MOVE IT OUT WITH AN UPPER LEVEL RIDGE BUILDING
OVER THE HIGH PLAINS. THIS WILL ULTIMATELY RESULT IN DECREASING
CHANCES FOR THUNDERSTORMS ALONG WITH A WARMING TREND.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 701 AM CDT FRI MAY 23 2014
VFR ceilings will continue through this morning. An area of scattered
showers and thunderstorms over the Texas Panhandle will spread north
across southwest and central Kansas late this morning and afternoon.
Some occasional MVFR ceilings could develop under the heavier
showers this afternoon. There is a small possibility that MVFR
ceilings and visibilities could develop at Dodge City and Hays but
confidence in this is pretty low at this time.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 78 62 81 61 / 70 70 60 60
GCK 77 60 81 60 / 70 70 60 60
EHA 76 57 80 57 / 60 60 60 60
LBL 78 60 79 59 / 70 70 60 70
HYS 78 63 79 62 / 70 70 40 60
P28 80 64 80 64 / 70 70 50 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Sugden
SHORT TERM...RUSSELL
LONG TERM...GERARD
AVIATION...Gerard
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
701 AM CDT Fri May 23 2014
...Updated aviation discussion...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI MAY 23 2014
ISENTROPIC LIFT WILL REDEVELOP LATER THIS MORNING IN A MOIST
ATMOSPHERE WITH PRECIPITABLE WATER VALUES IN EXCESS OF 1 INCH AS
FAR WEST AS EASTERN COLORADO. THIS SHOULD ALLOW SHOWER AND
THUNDERSTORMS TO DEVELOP EASILY WITH INCREASING LIFT. AS THE
THUNDERSTORMS HAVE DECAYED, WE`VE FOLLOWED THE HRRR TRENDS FOR
CONVECTION THROUGH AROUND 12-14 UTC, BEFORE SIGNIFICANTLY RAMPING UP
CHANCES TOWARD 18 UTC ONCE AGAIN. EXTENSIVE CLOUDS AND OCCASIONAL
PRECIPITATION ESPECIALLY BY THIS AFTERNOON WILL RELEGATE
TEMPERATURES HOMOGENEOUSLY IN THE 70S ACROSS MOST OF THE FORECAST
AREA. CAPE VALUES WILL BE NOT AS HIGH AS ON THURSDAY AND SEVERE
THREAT IS MINIMAL AS A RESULT. SHOWERS AND THUNDERSTORMS SHOULD
PERSIST INTO THE EVENING HOURS AND FORECAST PRECIPITATION CHANCES
WERE MAXIMIZED AROUND 0 UTC. AS A RESULT OF THE RELATIVELY HUMID
CONDITIONS, LOWS TONIGHT WILL LIKELY NOT FALL BELOW 60 DEGREES IN
MOST AREAS WITH FOG BECOMING POSSIBLE TOWARD EARLY MORNING
SATURDAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 418 AM CDT FRI MAY 23 2014
THE MEDIUM RANGE MODELS CONTINUE TO SHOW AN UPPER LEVEL LOW PRESSURE
SYSTEM MOVING SLOWLY FROM THE DESERT SOUTHWEST ON SATURDAY INTO THE
CENTRAL AND SOUTHERN HIGH PLAINS BY MEMORIAL DAY. AS THE UPPER LOW
APPROACHES THE REGION, LOW LEVEL SOUTHERLY FLOW WILL CONTINUE TO
PUMP GULF MOISTURE INTO THE CENTRAL HIGH PLAINS. WEAK DISTURBANCES
ROTATING AROUND THE UPPER LOW AND EJECTING OUT OVER THE CENTRAL
PLAINS WILL BRING THUNDERSTORM CHANCES TO WESTERN AND CENTRAL KANSAS
PRETTY MUCH EVERY DAY THROUGH TUESDAY. WIND FLOW WILL NOT BE OVERLY
STRONG OVER WESTERN KANSAS THE NEXT FEW DAYS BUT MODEL SOUNDINGS
SHOW SOME DIRECTIONAL SHEAR AND THERE SHOULD BE ENOUGH INSTABILITY
FOR AT LEAST A SMALL THREAT OF SEVERE WEATHER ON SATURDAY AFTERNOON
AND EVENING.
THE MODELS BEGIN TO DIVERGE A LITTLE ON HOW QUICKLY THE UPPER LOW
CONTINUES EAST OUT OF THE HIGH PLAINS TOWARD THE MIDDLE PART OF THE
WEEK BUT CONTINUE TO MOVE IT OUT WITH AN UPPER LEVEL RIDGE BUILDING
OVER THE HIGH PLAINS. THIS WILL ULTIMATELY RESULT IN DECREASING
CHANCES FOR THUNDERSTORMS ALONG WITH A WARMING TREND.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 701 AM CDT FRI MAY 23 2014
VFR ceilings will continue through this morning. An area of scattered
showers and thunderstorms over the Texas Panhandle will spread north
across southwest and central Kansas late this morning and afternoon.
Some occasional MVFR ceilings could develop under the heavier
showers this afternoon. There is a small possibility that MVFR
ceilings and visibilities could develop at Dodge City and Hays but
confidence in this is pretty low at this time.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 78 62 81 61 / 70 70 60 60
GCK 77 60 81 60 / 70 70 60 60
EHA 76 57 80 57 / 60 60 60 60
LBL 78 60 79 59 / 70 70 60 70
HYS 78 63 79 62 / 70 70 40 60
P28 80 64 80 64 / 70 70 50 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...GERARD
AVIATION...Gerard
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1045 AM EDT FRI MAY 23 2014
.UPDATE...
ISSUED AT 1045 AM EDT FRI MAY 23 2014
14Z SFC ANALYSIS SHOWS CANADIAN HIGH PRESSURE BUILDING INTO THE OHIO
VALLEY AS A NOW MOSTLY DRY COLD FRONT SETTLES SOUTH THROUGH EAST
KENTUCKY. A FEW LIGHT SHOWERS WERE ACCOMPANYING THIS BOUNDARY EARLIER
IN THE MORNING BUT HAVE SINCE DRIED UP. AS SUCH...EXPECT THE FRONT TO
CLEAR THE REST OF EAST KENTUCKY BY LATE AFTERNOON REMOVING THE THREAT
OF SHOWERS AND ALLOWING THE DRIER AIR TO WORK DEEPER INTO THE CWA.
CURRENTLY DEWPOINTS VARY FROM THE UPPER 40S AND LOWER 50S IN THE
NORTH OF THE AREA TO AROUND 60 IN THE FAR SOUTH. TEMPERATURES...
MEANWHILE ARE GENERALLY IN THE MID 60S. NORTH OF THE BOUNDARY WINDS
ARE FROM THE NORTH NORTHWEST AT 5 TO 10 KTS WITH LIGHT WINDS SOUTH OF
IT. HAVE UPDATED THE FORECAST TO LOWER POPS AND FINE TUNE SKY COVER
THROUGH THE REST OF THE DAY. HAVE ALSO TWEAKED THE NEAR TERM
TEMPERATURES AND DEWPOINTS PER THE LATEST GUIDANCE...OBS...AND
TRENDS. THE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS ALONG
WITH DISSEMINATION OF THE FRESHENED ZONES AND HWO...CLEANING UP THE
MORNING THUNDER CHANCES AND FOG.
UPDATE ISSUED AT 744 AM EDT FRI MAY 23 2014
UPDATED THE FORECAST TO HANDLE AT THE ISOLATED TO SCATTERED SHOWERS
THAT ARE MOVING ACROSS THE AREA THIS MORNING. HIGH PRESSURE WILL BE
MOVING IN THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 258 AM EDT FRI MAY 23 2014
THE ARE TWO THINGS GOING ON THIS MORNING. THE FIRST IS THE IS AREAS
OF DENSE VALLEY FOG AROUND THE AREA...ESPECIALLY SOUTH OF THE HAL
ROGERS PARKWAY. THE NEXT IS THE RADAR IS SHOWING SOME WEAK RETURNS
TRYING TO MOVING INTO THE BLUEGRASS REGION IN THE NEXT FEW HOURS AND
ALSO SOME STRONGER ECHOES OVER WESTERN KENTUCKY AND CENTRAL
TENNESSEE. OTHER THAN THE HRRR...NONE OF THE MODELS ARE HANDLING
THESE ISOLATED TO SCATTERED SHOWERS. THE HRRR WAS SHOWING THESE
SHOWERS WILL BE DYING AS THEY TRY TO ENTER EASTERN KENTUCKY THIS
MORNING. WILL BE GOING WITH THE HRRR...SINCE IT IS THE ONLY MODEL
WITH A CLUE RIGHT NOW. A WEAK COLD FRONT IS LYING ALONG THE
TENNESSEE AND KY BORDER. THIS FRONT IS FORECAST TO MOVE SLOWING
SOUTH WITH TIME AS HIGH PRESSURE BUILDS INTO THE AREA. EXPECT THE FOG
TO BE BURNING OFF BETWEEN 8 AND 9 AM THIS MORNING. THERE MAY BE SOME
DEBRIS CLOUDS MOVING INTO THE AREA THIS MORNING AND THEN DECREASING
CLOUDS THIS AFTERNOON AS THE FRONT PUSHES FURTHER TO THE SOUTH. THE
CONSENSUS BLEND LOOKED PRETTY GOOD AND THEN NUDGED IT TOWARD THE GFS
MOS FOR THE HIGHS TODAY AND TOMORROW.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 359 AM EDT FRI MAY 23 2014
THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH AN
OVERALL SLOWED PATTERN AS A SHORTWAVE EXITS THE EAST COAST. A
MASSIVE RIDGE TAKES SHAPE OVER THE CENTRAL CONUS WITH THE JET STREAM
DISPLACED TO THE NORTH ALONG THE CANADIAN BORDER WITH NUMEROUS WAVES
TRACKING ALONG IT. MEANWHILE...AN UPPER CLOSED LOW SLIPS UNDERNEATH
THE RIDGE AND MOVES EAST INTO THE CENTRAL PLAINS BY MONDAY. BY
MONDAY NIGHT...A STRONGER SHORTWAVE DIVES SOUTH OVER THE EASTERN
GREAT LAKES AND INTO THE THE MID ATLANTIC STATES. BY MID WEEK...THE
PATTERN COMPLETELY STALLS WITH THE UPPER LOW OVER THE MID MS RIVER
VALLEY AND THE TROUGH OVER THE NEW ENGLAND STATES REMAINING. THE
PROMISING DETAIL HERE IS THAT BOTH THE GFS AND EURO AGREE ON
THIS...ONLY WITH MINOR DIFFERENCES. HOWEVER...THIS BEING A BLOCKING
PATTERN...THE MODELS MAY NOT HANDLE THE SET UP VERY WELL.
WITH THE UPPER LOW DRIFTING EAST ON TUESDAY AND THE FRONT ASSOCIATED
WITH THE WAVE OVER THE GREAT LAKES PUSHING SOUTH...THIS WILL SET THE
STAGE FOR SOME SHOWER AND THUNDERSTORM ACTIVITY FOR MONDAY THROUGH
THURSDAY. THIS ACTIVITY WILL ALSO LIKELY HAVE SOME DIURNAL
CHARACTERISTICS TO IT. AS WELL...DUE TO THE UNCERTAIN NATURE OF THIS
PATTERN...DID NOT GO ABOVE CHANCE POPS...ESPECIALLY FOR MONDAY AND
TUESDAY...WITH THAT UPPER LEVEL SUPPORT BARELY MAKING IT INTO THE
AREA. WITH THAT SAID...PLENTY OF WARMTH IN THIS PATTERN...DAYTIME
MAX HIGHS GETTING INTO THE 80S JUST ABOUT EVERYDAY OF THE EXTENDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 744 AM EDT FRI MAY 23 2014
EXPECT VFR CONDITIONS ALL DAY TODAY ONCE THE VALLEY FOG BURNS OFF
BETWEEN 8 AND 9 AM THIS MORNING. EXPECT TO SEE SOME VALLEY FOG AGAIN
TONIGHT AS THERE IS SUFFICIENT LOW LEVEL MOISTURE STILL IN THE
VALLEYS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JJ
LONG TERM...SHALLENBERGER
AVIATION...JJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
743 AM EDT FRI MAY 23 2014
.UPDATE...
ISSUED AT 744 AM EDT FRI MAY 23 2014
UPDATED THE FORECAST TO HANDLE AT THE ISOLATED TO SCATTERED SHOWERS
THAT ARE MOVING ACROSS THE AREA THIS MORNING. HIGH PRESSURE WILL BE
MOVING IN THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 258 AM EDT FRI MAY 23 2014
THE ARE TWO THINGS GOING ON THIS MORNING. THE FIRST IS THE IS AREAS
OF DENSE VALLEY FOG AROUND THE AREA...ESPECIALLY SOUTH OF THE HAL
ROGERS PARKWAY. THE NEXT IS THE RADAR IS SHOWING SOME WEAK RETURNS
TRYING TO MOVING INTO THE BLUEGRASS REGION IN THE NEXT FEW HOURS AND
ALSO SOME STRONGER ECHOES OVER WESTERN KENTUCKY AND CENTRAL
TENNESSEE. OTHER THAN THE HRRR...NONE OF THE MODELS ARE HANDLING
THESE ISOLATED TO SCATTERED SHOWERS. THE HRRR WAS SHOWING THESE
SHOWERS WILL BE DYING AS THEY TRY TO ENTER EASTERN KENTUCKY THIS
MORNING. WILL BE GOING WITH THE HRRR...SINCE IT IS THE ONLY MODEL
WITH A CLUE RIGHT NOW. A WEAK COLD FRONT IS LYING ALONG THE
TENNESSEE AND KY BORDER. THIS FRONT IS FORECAST TO MOVE SLOWING
SOUTH WITH TIME AS HIGH PRESSURE BUILDS INTO THE AREA. EXPECT THE FOG
TO BE BURNING OFF BETWEEN 8 AND 9 AM THIS MORNING. THERE MAY BE SOME
DEBRIS CLOUDS MOVING INTO THE AREA THIS MORNING AND THEN DECREASING
CLOUDS THIS AFTERNOON AS THE FRONT PUSHES FURTHER TO THE SOUTH. THE
CONSENSUS BLEND LOOKED PRETTY GOOD AND THEN NUDGED IT TOWARD THE GFS
MOS FOR THE HIGHS TODAY AND TOMORROW.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 359 AM EDT FRI MAY 23 2014
THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH AN
OVERALL SLOWED PATTERN AS A SHORTWAVE EXITS THE EAST COAST. A
MASSIVE RIDGE TAKES SHAPE OVER THE CENTRAL CONUS WITH THE JET STREAM
DISPLACED TO THE NORTH ALONG THE CANADIAN BORDER WITH NUMEROUS WAVES
TRACKING ALONG IT. MEANWHILE...AN UPPER CLOSED LOW SLIPS UNDERNEATH
THE RIDGE AND MOVES EAST INTO THE CENTRAL PLAINS BY MONDAY. BY
MONDAY NIGHT...A STRONGER SHORTWAVE DIVES SOUTH OVER THE EASTERN
GREAT LAKES AND INTO THE THE MID ATLANTIC STATES. BY MID WEEK...THE
PATTERN COMPLETELY STALLS WITH THE UPPER LOW OVER THE MID MS RIVER
VALLEY AND THE TROUGH OVER THE NEW ENGLAND STATES REMAINING. THE
PROMISING DETAIL HERE IS THAT BOTH THE GFS AND EURO AGREE ON
THIS...ONLY WITH MINOR DIFFERENCES. HOWEVER...THIS BEING A BLOCKING
PATTERN...THE MODELS MAY NOT HANDLE THE SET UP VERY WELL.
WITH THE UPPER LOW DRIFTING EAST ON TUESDAY AND THE FRONT ASSOCIATED
WITH THE WAVE OVER THE GREAT LAKES PUSHING SOUTH...THIS WILL SET THE
STAGE FOR SOME SHOWER AND THUNDERSTORM ACTIVITY FOR MONDAY THROUGH
THURSDAY. THIS ACTIVITY WILL ALSO LIKELY HAVE SOME DIURNAL
CHARACTERISTICS TO IT. AS WELL...DUE TO THE UNCERTAIN NATURE OF THIS
PATTERN...DID NOT GO ABOVE CHANCE POPS...ESPECIALLY FOR MONDAY AND
TUESDAY...WITH THAT UPPER LEVEL SUPPORT BARELY MAKING IT INTO THE
AREA. WITH THAT SAID...PLENTY OF WARMTH IN THIS PATTERN...DAYTIME
MAX HIGHS GETTING INTO THE 80S JUST ABOUT EVERYDAY OF THE EXTENDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 744 AM EDT FRI MAY 23 2014
EXPECT VFR ALL DAY TODAY ONCE THE VALLEY FOG BURNS OFF BETWEEN 8 AND
9 AM THIS MORNING. EXPECT TO SEE SOME VALLEY FOG AGAIN TONIGHT. THERE
IS SUFFICIENT LOW LEVEL MOISTURE IN THE VALLEYS TO PRODUCE VALLY
FOG AGAIN TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJ
SHORT TERM...JJ
LONG TERM...SHALLENBERGER
AVIATION...JJ
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
903 AM EDT FRI MAY 23 2014
.SYNOPSIS...
WEAK LOW PRESSURE OVER EASTERN NEW YORK AND WESTERN NEW ENGLAND
WILL GRADUALLY SAG SOUTH THROUGH SOUTHERN NEW ENGLAND TODAY AND
WILL TURN EAST PASSING OUT TO SEA TONIGHT. A TROUGH OF LOW
PRESSURE WILL LINGER OVER THE REGION ON SATURDAY. WEAK HIGH
PRESSURE WILL BUILD OVER THE REGION SATURDAY NIGHT AND SUNDAY. LOW
PRESSURE WILL APPROACH FROM THE NORTH SUNDAY NIGHT AND WILL PUSH
SOUTHEAST THROUGH THE REGION ON MONDAY. LOW PRESSURE WILL SHIFT
EAST INTO THE MARITIMES MONDAY NIGHT. HIGH PRESSURE WILL BUILD IN
FROM THE NORTHEAST ON TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...SFC TROF LINGERS IN PLACE OVER SWRN PORTIONS OF CWFA.
SHRA WILL CONTINUE ALONG AND E OF THE TROF THRU THE DAY. GRADUALLY
THIS IS EXPECTED TO DRIFT SWD THRU THE AFTERNOON...BRINGING AN END
TO SHRA FROM N TO S AS IT DOES SO. THE LATEST HRRR SUPPORTS THIS
EVOLUTION THRU THE DAY...SO HAVE BLENDED THE FORECAST IN THIS
DIRECTION.
PREVIOUS DISCUSSION...TROUGH OF LOW PRESSURE DRAPED ACROSS
CENTRAL NEW HAMPSHIRE AND SOUTHWEST MAINE WILL BE THE FOCUS FOR
SHOWER ACTIVITY THROUGH THE DAY. RADAR SHOWING SHOWERS CURRENTLY
EXPANDING IN COVERAGE IN THIS GENERAL VICINITY ON RADAR AND EXPECT
THIS ACTIVITY TO LIFT INTO CENTRAL MAINE AND THE MOUNTAINS THROUGH
MID MORNING. SURFACE TROUGH WILL GRADUALLY SAG SOUTH INTO SOUTHERN
NEW ENGLAND THIS AFTERNOON AND EXPECT SHOWERS TO FOLLOW IT
SOUTHWARD DURING THE LATE AFTERNOON AND EVENING HOURS. PERSISTENT
ONSHORE FLOW WILL KEEP LOW CLOUDS IN PLACE ACROSS MUCH OF THE
FORECAST AREA TODAY IN CENTRAL AND SOUTHERN AREAS...ALTHOUGH THERE
MAY BE A FEW SUNNY BREAKS IN THE FAR NORTH. TEMPERATURES WILL
AVERAGE OUT WELL BELOW NORMAL WITH UPPER 50S TO LOWER 60S IN
INLAND LOCATIONS AND LOWER TO MID 50S ALONG THE COAST.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
WEAK LOW PRESSURE WILL PUSH OFF THE SOUTHERN NEW ENGLAND COAST
THIS EVENING AND WILL SLOWLY HEAD EAST OVERNIGHT. WILL SEE ANOTHER
CLOUDY NIGHT WITH AREAS OF FOG AND DRIZZLE AND PERHAPS A FEW
LINGERING SHOWERS DURING THE EVENING IN SOUTHERN ZONES. SHOULD SEE
FAIRLY UNIFORM LOWS ACROSS THE AREA OVERNIGHT WITH MOST LOCATIONS
BOTTOMING OUT IN THE MID TO UPPER 40S.
TROUGH OF LOW PRESSURE WILL LINGER OVER THE AREA ON SATURDAY. VERY
LITTLE GRADIENT TO HELP SHIFT LOW LEVEL MOISTURE OUT OF THE AREA
SO NOT LOOKING FOR MUCH SUN IN SOUTHERN AND COASTAL AREAS OF MAINE
AND NEW HAMPSHIRE. FARTHER INLAND ANY SUNNY BREAKS WILL COMBINE
WITH MARGINAL INSTABILITY TO POP OFF A FEW SHOWERS AND POSSIBLY A
THUNDERSTORM. HIGH TEMPS WILL ONLY TOP OUT IN THE LOWER TO MID 60S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
UNSETTLED WX THRU THE LONG TERM FCST PERIOD AS THE LONG WAVE TROF
POSITION REMAINS OVER THE ERN U.S. WITH THE LONG WAVE RIDGE SET UP
OVER THE CENTRAL PART OF THE U.S. THIS PATTERN ALLOWS EACH WEAK
SHORT WAVE TROF PROGRESSING TO THE E TO AMPLIFY AS IT REACHES THE
E COAST...IN SOME CASES FORMING A CUT OFF LOW THAT SLOWS DOWN SFC
SYSTEMS OVER THE REGION THUS PROLONGING THE PERIOD OF SHRA
ACTIVITY. THE CUTOFF LOW FORMS MONDAY NGT TO OUR NW THEN DRIFTS
OVERHEAD ON TUESDAY AND TUESDAY NGT BRINGING A STRONGER SFC LOW
THRU WITH THE BEST CHC OF SHRA ACTIVITY. USED A BLEND OF MODELS,
PREVIOUS FCST AND CLIMATOLOGY FOR THE LONG TERM FCST.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...WIDESPREAD IFR/LIFR CEILINGS THIS MORNING...IMPROVING
TO MVFR WITH AREAS OF IFR CEILINGS THIS AFTERNOON. MVFR/IFR
CEILINGS TONIGHT AND AREAS OF MVFR/IFR CEILINGS ON SATURDAY.
LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...SCT SHRA...WITH
GREATER CHC ACROSS THE N/MT AREAS...WITH MVFR CIG/VSBY MOST
LIKELY THRU THE LONG TERM FCST PERIOD.
&&
.MARINE...
SHORT TERM...NO FLAGS.
LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...FAIRLY WEAK PRESSURE
PATTERN KEEPS WINDS AND SEAS BELOW SCA LEVELS...THOUGH SEAS MAY
APPROACH 5 FT OVER THE OUTER MOST WATERS ON TUESDAY.
&&
.FIRE WEATHER...
HIGH HUMIDITY AND LIGHT WINDS WILL PERSIST
THROUGH SATURDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...LEGRO
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1114 AM EDT FRI MAY 23 2014
.SYNOPSIS...
ISSUED AT 332 AM EDT FRI MAY 23 2014
HIGH PRESSURE WILL BUILD INTO THE REGION BY LATER TODAY AND REMAIN
IN CONTROL OF THE WEATHER THROUGH SUNDAY. THEREFORE...CLEARING SKIES
AND MODERATING TEMPERATURES WILL MOVE IN BY THIS AFTERNOON WITH
COMFORTABLE TEMPERATURES AND LOTS OF SUNSHINE EXPECTED FOR BOTH
SATURDAY AND SUNDAY. SHOWERS AND A FEW THUNDERSTORMS THEN LOOK
LIKELY MEMORIAL DAY AS A SYSTEM DROPS DOWN FROM THE NORTHWEST.
&&
.UPDATE...
ISSUED AT 1114 AM EDT FRI MAY 23 2014
CLOUDS THINNING AWAY NICELY THIS MORNING WITH A MUCH SHALLOWER
MOISTURE PROFILE THIS MORNING PER 12Z KAPX RAOB VERSUS THURSDAY
MORNING. STILL SOME CLOUD COVER FLIRTING WITH NORTHEAST LOWER
DROPPING SOUTH/SOUTHWEST OUT OF ONTARIO...THAT MAY BE THE ONE
PROBLEM AREA THIS AFTERNOON THOUGH WITH WEAK OVERALL SUBSIDENCE
AND CONTINUED HEATING WE`LL SEE HOW MUCH CLOUD COVER WILL PREVAIL
THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 332 AM EDT FRI MAY 23 2014
...CLOUDS GRADUALLY GIVE WAY TO SUN TODAY...
HIGH IMPACT WEATHER POTENTIAL: LOW THREAT OF FROST FOR INTERIOR
NORTHERN LOWER TONIGHT.
PATTERN SUMMARY: NORTHWEST FLOW ON CONTROL OF OUR REGION/S WEATHER
AS OF THIS WRITING WITH LOW HEIGHT ANOMALY OVER EASTERN
CANADA...WITH UPSTREAM HEIGHTS BUILDING OVER THE WESTERN UNITED
STATES NORTH OF A STATIONARY CUTOFF LOW ACROSS THE SOUTHWESTERN
PORTION OF THE COUNTRY. LAST IN A SERIES OF SHORTWAVES MAKING ITS
CLOSEST APPROACH TO NORTHERN MICHIGAN AS OF THIS WRITING...HELPING
SPAWN A FEW SPRINKLES ALONG THE COAST OF NORTHEAST LOWER MICHIGAN
AND NORTHERN LAKE HURON. AS THIS FEATURE CONTINUES TO MOVE SOUTH
AND EAST...SHORTWAVE RIDGING WILL BUILD IN IT/S PLACE. THIS IS
MANIFESTED AS A MODEST 1023 MB HIGH ALONG THE ONTARIO/MINNESOTA
BOARDER...WHICH WILL SLIDE INTO NORTHERN MICHIGAN THROUGH THE
UPCOMING FORECAST PERIOD. THIS SETUP SUGGESTS FAIR WEATHER...BUT WE
HAVE SOME LLEVEL STRATUS OVERHEAD ASSOCIATED WITH NEARBY SHORTWAVE
THAT WILL BE RELUCTANT TO LEAVE AND THUS COMPLICATE THE EARLY
PORTION OF THIS FORECAST THIS AM. BEYOND THIS...ATTENTION TURNS TO
WHAT LOOKS TO BE THE POTENTIAL FOR A CHILLY /FROSTY?/ NIGHT FRIDAY
NIGHT.
THROUGH DAYBREAK: STILL TRACKING AREA OF SPRINKLES ALONG THE COAST
OF NORTHEAST LOWER...THESE WILL CONTINUE TO SINK SOUTH WITH LOW
CLOUDS CONTINUING TO EXPAND ACROSS NORTHERN LOWER. ANY SPRINKLE
THREAT SHOULD END BY 09-10Z...WITH A LITTLE PATCHY DRIZZLE/SPRINKLE
ACTIVITY ALSO NOT OUT OF THE QUESTION THROUGH DAYBREAK ACROSS THE
HIGHER TERRAIN OF NORTHERN LOWER.
TODAY: PRIMARY CONCERN TODAY REVOLVES AROUND CLOUD COVER...IT/S
EROSION AND IMPACTS ON TEMPERATURES. PRETTY BIG MODEL DISPARITIES
IN HANDLING THE BOUNDARY LAYER MOISTURE FIELD THIS MORNING WITH THE
NAM MUCH MORE AGGRESSIVE IN MORNING CLEARING WHILE THE RAP AND OUR
IN HOUSE LOCAL WRF WOULD LIKE TO MAINTAIN LLEVEL SATURATION OVER
MUCH OF NORTHERN LOWER AT LEAST THROUGH THE NOON HOUR. TRACKING
BACK THIS CLOUD DECK 24 HOURS TO A LOCATION JUST WEST OF JAMES BAY
SUGGESTS A PRETTY SLOW CLEARING PROCESS...AND THAT IS IN LINE WITH
PATTERN RECOGNITION OF SOME MOISTURE GETTING TRAPPED BENEATH
DEVELOPING SUBSIDENCE INVERSION...AS WELL AS RECENT GFS LAMP
GUIDANCE. THUS...WILL DELAY CLEARING UNTIL ABOUT NOON OVER NORTHERN
LOWER...AND DURING THE MID MORNING OVER EASTERN UPPER. THE SUN WILL
EVENTUALLY WIN OUT...HOWEVER...WITH SKIES BECOMING MOSTLY CLEAR
TOWARDS EVENING.
TEMPERATURES /CONFIDENCE: MODERATE-HIGH/: EXPECT CLOUDS TO HAVE SOME
IMPACT ON TEMPERATURES...LIMITING THE DIURNAL HEATING WINDOW.
STILL...DAYS ARE LONG AND T8S AROUND +5-6 SUGGEST MID 60S FOR
HIGHS...AND EXPECT THAT WE/LL REACH THESE VALUES...BUT LATE IN THE
DAY.
TONIGHT: HIGH PRESSURE SETTLES OVERHEAD WITH VERY QUIET CONDITIONS
EXPECTED. WITH AMPLIFYING LONGWAVE RIDGE TO OUR WEST...
NAM/GFS/ECMWF WANT TO SPILL SOME MID/UPPER LEVEL MOISTURE OVER THE
ARRIVING MID LEVEL RIDGING...IMPACTING EASTERN UPPER AND FAR
NORTHERN LOWER AFTER MIDNIGHT. WILL INDICATE PARTLY CLOUDY SKIES
HERE...WITH MOSTLY CLEAR CONDITIONS TO THE SOUTH OF THIS. ONLY
POTENTIAL IMPACT OF THIS CLOUD COVER MAY BE TO KEEP A LID ON
TEMPERATURES FALLING TOO FAR IN THESE LOCALES.
TEMPERATURES /CONFIDENCE: MODERATE-HIGH/: CHILLY NIGHT IN STORE WITH
AFTERNOON DEWPOINTS LIKELY TO MIX OUT INTO THE UPPER 30S BY LATE IN
THE DAY IN SOME OF OUR INTERIOR DRY SPOTS. THIS WILL GIVE US PLENTY
OF ROOM TO COOL OVERNIGHT AS HIGH PRESSURE BUILDS OVERHEAD.
COMPLICATING FACTORS WILL BE POTENTIAL CLOUDS NORTH...AND SOME
RESIDUAL GRADIENT ALONG THE COAST OF NORTHEAST LOWER. STILL...
LOCALES FROM CAD TO GOV SHOULD BE ABLE TO CROSS INTO THE UPPER
30S...AND HAVE SOME CONCERNS WE MAY GO FURTHER THAN THIS DEPENDING
ON HOW TEMPS/DEWPOINTS EVOLVE TODAY /LATER CLEARING LIMITING
HIGHS/. WORST CASE SCENARIO /SIMILAR TO MAV/ WOULD ALLOW FOR A
LITTLE PATCHY FROST FOR THE INTERIOR /NO FREEZE EXPECTED/...BUT
EXPECTATIONS AT THIS TIME IS A LITTLE WARMER THAN THIS /ALTHOUGH
COOLER THAN INHERITED LOWS/. WILL PAINT UPPER 30S TO LOWER 40S WITH
NO HWO MENTION THIS GO AROUND.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 332 AM EDT FRI MAY 23 2014
...NICE START TO THE MEMORIAL DAY WEEKEND...
...HIGH IMPACT WEATHER POTENTIAL: NONE TO VERY LOW.
RIDGING AT THE SURFACE AND ALOFT PROMISES TO BRING PLEASANT LATE
SPRING CONDITIONS TO THE REGION SATURDAY INTO SUNDAY.
HOWEVER...NORTHERN STREAM ENERGY TRACKING ACROSS CANADA POSSIBLY IN
COMBINATION WITH A CUTOFF UPPER LOW EVIDENT ON WATER VAPOR IMAGERY
WILL LIKELY BRING SHOWERY CONDITIONS TO NORTHERN MICHIGAN FOR YOUR
MEMORIAL DAY (SORRY ABOUT THAT ONE). MORE RIDGING THEN BUILDS IN FOR
TUESDAY THROUGH THURSDAY LIKELY BRINGING ANOTHER DECENT STRETCH OF
WEATHER TO THE REGION.
SATURDAY INTO SUNDAY...SURFACE RIDGE CONTINUES TO MOVE ACROSS THE
REGION WITH HEIGHTS STEADILY RISING. A WEAK AND MOISTURE STARVED
SHORT WAVE SNEAKS UNDER THE RIDGE SATURDAY...WITH ONLY A PERIOD OF
MID LEVEL CLOUDS EXPECTED. OTHERWISE...CLEAR TO PARTLY CLOUDY SKIES
WITH PLEASANT TEMPERATURES ANTICIPATED. HIGHS MAINLY IN THE 70S
(EVEN A FEW LOWER 80S SUNDAY AFTERNOON) AND LOWS IN THE MIDDLE 40S
TO LOWER 50S.
SUNDAY NIGHT THROUGH MONDAY NIGHT...THE RIDGE TEMPORARILY BREAKS
DOWN ALLOWING A SYSTEM CRUISING ACROSS CANADA TO DROP DOWN FROM THE
NORTHWEST. A NICE LITTLE JET CORE IS SHOWN TO ACCOMPANY THIS FEATURE
SO IN COMBINATION WITH DAYTIME HEATING (AND POSSIBLY ENERGY FROM THE
WEAKENING CUTOFF UPPER LOW FROM THE SOUTHWEST)...SHOWERS AND
THUNDERSTORMS LOOK LIKELY. IN ADDITION...A NARROW THETA-E RIDGE
MOVES ACROSS THE REGION. EXPECT THE BEST CHANCE FOR SHOWERS AND
STORMS TO BE MONDAY AFTERNOON AND EVENING. IT IS STILL TOO EARLY TO
PIN DOWN SEVERE POTENTIAL BUT WILL HAVE TO MONITOR THE EVOLUTION OF
THE POSSIBLE JETLET AS A FEW STORMS MAY HAVE THE POTENTIAL TO BE ON
THE STRONGER SIDE.
TUESDAY THROUGH THURSDAY...PERHAPS SOME LOW CLOUDS AROUND TO START
OFF TUESDAY (THOUGH OVER LAKE INSTABILITY IS MUCH LESS THAN OUR
LATEST GO AROUND). OTHERWISE...RENEWED RIDGING AT THE SURFACE AND
ALOFT SHOULD LEAD TO ANOTHER STRETCH OF FINE LATE SPRING WEATHER.
HIGHS RANGING FROM THE MIDDLE 60S NORTH TO THE MIDDLE 70S SOUTH AND
LOWS IN THE MIDDLE 40S TO MIDDLE 50S (WHICH IS ALMOST PERFECT
SLEEPING WEATHER IF YOU ASK ME).
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 630 AM EDT FRI MAY 23 2014
SUMMARY: HIGH PRESSURE BUILDS INTO THE GREAT LAKES DURING THE
UPCOMING FORECAST PERIOD WITH IMPROVING FLYING CONDITIONS EXPECTED.
RESTRICTIONS: ONGOING STRATUS WILL BRING GENERALLY MVFR RESTRICTIONS
THROUGH MID MORNING BEFORE SCATTERING OUT FOR THE AFTERNOON.
SCATTERED VFR CLOUDINESS FOR THE AFTERNOON WILL GIVE WAY TO
MOSTLY CLEAR SKIES TONIGHT /OUTSIDE OF SOME SCATTERED MID-UPPER
LEVEL CLOUDINESS NORTH/.
WINDS: NORTHWEST WINDS WILL STRENGTHEN TO 10G18KTS FOR THE DAY TODAY
BEFORE DIMINISHING TO CALM/LIGHT-VARIABLE TONIGHT.
LLWS: NO THREAT THIS CYCLE.
THUNDER: NO THREAT THIS CYCLE.
&&
.MARINE...
ISSUED AT 332 AM EDT FRI MAY 23 2014
SUMMARY: HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES REGION TODAY
AND TONIGHT...WITH NORTHWESTERLY WINDS GRADUALLY DECREASING. HIGH
PRESSURE WILL REMAIN OVERHEAD THROUGH SATURDAY BEFORE SHIFTING
SOUTH AND EAST OF THE REGION BY SUNDAY WITH LOW PRESSURE ARRIVING
SUNDAY NIGHT/MONDAY...WITH A ROUND OF SOUTHWEST WINDS BEFORE WINDS
SHIFT AGAIN TO THE NORTHWEST BY THE MIDDLE OF NEXT WEEK.
HEADLINES: MARGINAL SMALL CRAFT CONDITIONS POSSIBLE NEAR PRESQUE
ISLE FOR A TIME TODAY...OTHERWISE...HEADLINE FREE CONDITIONS LOOK TO
BE IN STORE THROUGH THE UPCOMING WEEKEND.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JPB
SYNOPSIS...AS
SHORT TERM...ARNOTT
LONG TERM...AS
AVIATION...ARNOTT
MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS GAYLORD MI
634 AM EDT FRI MAY 23 2014
.SYNOPSIS...
ISSUED AT 332 AM EDT FRI MAY 23 2014
HIGH PRESSURE WILL BUILD INTO THE REGION BY LATER TODAY AND REMAIN
IN CONTROL OF THE WEATHER THROUGH SUNDAY. THEREFORE...CLEARING SKIES
AND MODERATING TEMPERATURES WILL MOVE IN BY THIS AFTERNOON WITH
COMFORTABLE TEMPERATURES AND LOTS OF SUNSHINE EXPECTED FOR BOTH
SATURDAY AND SUNDAY. SHOWERS AND A FEW THUNDERSTORMS THEN LOOK
LIKELY MEMORIAL DAY AS A SYSTEM DROPS DOWN FROM THE NORTHWEST.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 332 AM EDT FRI MAY 23 2014
...CLOUDS GRADUALLY GIVE WAY TO SUN TODAY...
HIGH IMPACT WEATHER POTENTIAL: LOW THREAT OF FROST FOR INTERIOR
NORTHERN LOWER TONIGHT.
PATTERN SUMMARY: NORTHWEST FLOW ON CONTROL OF OUR REGION/S WEATHER
AS OF THIS WRITING WITH LOW HEIGHT ANOMALY OVER EASTERN
CANADA...WITH UPSTREAM HEIGHTS BUILDING OVER THE WESTERN UNITED
STATES NORTH OF A STATIONARY CUTOFF LOW ACROSS THE SOUTHWESTERN
PORTION OF THE COUNTRY. LAST IN A SERIES OF SHORTWAVES MAKING ITS
CLOSEST APPROACH TO NORTHERN MICHIGAN AS OF THIS WRITING...HELPING
SPAWN A FEW SPRINKLES ALONG THE COAST OF NORTHEAST LOWER MICHIGAN
AND NORTHERN LAKE HURON. AS THIS FEATURE CONTINUES TO MOVE SOUTH
AND EAST...SHORTWAVE RIDGING WILL BUILD IN IT/S PLACE. THIS IS
MANIFESTED AS A MODEST 1023 MB HIGH ALONG THE ONTARIO/MINNESOTA
BOARDER...WHICH WILL SLIDE INTO NORTHERN MICHIGAN THROUGH THE
UPCOMING FORECAST PERIOD. THIS SETUP SUGGESTS FAIR WEATHER...BUT WE
HAVE SOME LLEVEL STRATUS OVERHEAD ASSOCIATED WITH NEARBY SHORTWAVE
THAT WILL BE RELUCTANT TO LEAVE AND THUS COMPLICATE THE EARLY
PORTION OF THIS FORECAST THIS AM. BEYOND THIS...ATTENTION TURNS TO
WHAT LOOKS TO BE THE POTENTIAL FOR A CHILLY /FROSTY?/ NIGHT FRIDAY
NIGHT.
THROUGH DAYBREAK: STILL TRACKING AREA OF SPRINKLES ALONG THE COAST
OF NORTHEAST LOWER...THESE WILL CONTINUE TO SINK SOUTH WITH LOW
CLOUDS CONTINUING TO EXPAND ACROSS NORTHERN LOWER. ANY SPRINKLE
THREAT SHOULD END BY 09-10Z...WITH A LITTLE PATCHY DRIZZLE/SPRINKLE
ACTIVITY ALSO NOT OUT OF THE QUESTION THROUGH DAYBREAK ACROSS THE
HIGHER TERRAIN OF NORTHERN LOWER.
TODAY: PRIMARY CONCERN TODAY REVOLVES AROUND CLOUD COVER...IT/S
EROSION AND IMPACTS ON TEMPERATURES. PRETTY BIG MODEL DISPARITIES
IN HANDLING THE BOUNDARY LAYER MOISTURE FIELD THIS MORNING WITH THE
NAM MUCH MORE AGGRESSIVE IN MORNING CLEARING WHILE THE RAP AND OUR
IN HOUSE LOCAL WRF WOULD LIKE TO MAINTAIN LLEVEL SATURATION OVER
MUCH OF NORTHERN LOWER AT LEAST THROUGH THE NOON HOUR. TRACKING
BACK THIS CLOUD DECK 24 HOURS TO A LOCATION JUST WEST OF JAMES BAY
SUGGESTS A PRETTY SLOW CLEARING PROCESS...AND THAT IS IN LINE WITH
PATTERN RECOGNITION OF SOME MOISTURE GETTING TRAPPED BENEATH
DEVELOPING SUBSIDENCE INVERSION...AS WELL AS RECENT GFS LAMP
GUIDANCE. THUS...WILL DELAY CLEARING UNTIL ABOUT NOON OVER NORTHERN
LOWER...AND DURING THE MID MORNING OVER EASTERN UPPER. THE SUN WILL
EVENTUALLY WIN OUT...HOWEVER...WITH SKIES BECOMING MOSTLY CLEAR
TOWARDS EVENING.
TEMPERATURES /CONFIDENCE: MODERATE-HIGH/: EXPECT CLOUDS TO HAVE SOME
IMPACT ON TEMPERATURES...LIMITING THE DIURNAL HEATING WINDOW.
STILL...DAYS ARE LONG AND T8S AROUND +5-6 SUGGEST MID 60S FOR
HIGHS...AND EXPECT THAT WE/LL REACH THESE VALUES...BUT LATE IN THE
DAY.
TONIGHT: HIGH PRESSURE SETTLES OVERHEAD WITH VERY QUIET CONDITIONS
EXPECTED. WITH AMPLIFYING LONGWAVE RIDGE TO OUR WEST...
NAM/GFS/ECMWF WANT TO SPILL SOME MID/UPPER LEVEL MOISTURE OVER THE
ARRIVING MID LEVEL RIDGING...IMPACTING EASTERN UPPER AND FAR
NORTHERN LOWER AFTER MIDNIGHT. WILL INDICATE PARTLY CLOUDY SKIES
HERE...WITH MOSTLY CLEAR CONDITIONS TO THE SOUTH OF THIS. ONLY
POTENTIAL IMPACT OF THIS CLOUD COVER MAY BE TO KEEP A LID ON
TEMPERATURES FALLING TOO FAR IN THESE LOCALES.
TEMPERATURES /CONFIDENCE: MODERATE-HIGH/: CHILLY NIGHT IN STORE WITH
AFTERNOON DEWPOINTS LIKELY TO MIX OUT INTO THE UPPER 30S BY LATE IN
THE DAY IN SOME OF OUR INTERIOR DRY SPOTS. THIS WILL GIVE US PLENTY
OF ROOM TO COOL OVERNIGHT AS HIGH PRESSURE BUILDS OVERHEAD.
COMPLICATING FACTORS WILL BE POTENTIAL CLOUDS NORTH...AND SOME
RESIDUAL GRADIENT ALONG THE COAST OF NORTHEAST LOWER. STILL...
LOCALES FROM CAD TO GOV SHOULD BE ABLE TO CROSS INTO THE UPPER
30S...AND HAVE SOME CONCERNS WE MAY GO FURTHER THAN THIS DEPENDING
ON HOW TEMPS/DEWPOINTS EVOLVE TODAY /LATER CLEARING LIMITING
HIGHS/. WORST CASE SCENARIO /SIMILAR TO MAV/ WOULD ALLOW FOR A
LITTLE PATCHY FROST FOR THE INTERIOR /NO FREEZE EXPECTED/...BUT
EXPECTATIONS AT THIS TIME IS A LITTLE WARMER THAN THIS /ALTHOUGH
COOLER THAN INHERITED LOWS/. WILL PAINT UPPER 30S TO LOWER 40S WITH
NO HWO MENTION THIS GO AROUND.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 332 AM EDT FRI MAY 23 2014
...NICE START TO THE MEMORIAL DAY WEEKEND...
...HIGH IMPACT WEATHER POTENTIAL: NONE TO VERY LOW.
RIDGING AT THE SURFACE AND ALOFT PROMISES TO BRING PLEASANT LATE
SPRING CONDITIONS TO THE REGION SATURDAY INTO SUNDAY.
HOWEVER...NORTHERN STREAM ENERGY TRACKING ACROSS CANADA POSSIBLY IN
COMBINATION WITH A CUTOFF UPPER LOW EVIDENT ON WATER VAPOR IMAGERY
WILL LIKELY BRING SHOWERY CONDITIONS TO NORTHERN MICHIGAN FOR YOUR
MEMORIAL DAY (SORRY ABOUT THAT ONE). MORE RIDGING THEN BUILDS IN FOR
TUESDAY THROUGH THURSDAY LIKELY BRINGING ANOTHER DECENT STRETCH OF
WEATHER TO THE REGION.
SATURDAY INTO SUNDAY...SURFACE RIDGE CONTINUES TO MOVE ACROSS THE
REGION WITH HEIGHTS STEADILY RISING. A WEAK AND MOISTURE STARVED
SHORT WAVE SNEAKS UNDER THE RIDGE SATURDAY...WITH ONLY A PERIOD OF
MID LEVEL CLOUDS EXPECTED. OTHERWISE...CLEAR TO PARTLY CLOUDY SKIES
WITH PLEASANT TEMPERATURES ANTICIPATED. HIGHS MAINLY IN THE 70S
(EVEN A FEW LOWER 80S SUNDAY AFTERNOON) AND LOWS IN THE MIDDLE 40S
TO LOWER 50S.
SUNDAY NIGHT THROUGH MONDAY NIGHT...THE RIDGE TEMPORARILY BREAKS
DOWN ALLOWING A SYSTEM CRUISING ACROSS CANADA TO DROP DOWN FROM THE
NORTHWEST. A NICE LITTLE JET CORE IS SHOWN TO ACCOMPANY THIS FEATURE
SO IN COMBINATION WITH DAYTIME HEATING (AND POSSIBLY ENERGY FROM THE
WEAKENING CUTOFF UPPER LOW FROM THE SOUTHWEST)...SHOWERS AND
THUNDERSTORMS LOOK LIKELY. IN ADDITION...A NARROW THETA-E RIDGE
MOVES ACROSS THE REGION. EXPECT THE BEST CHANCE FOR SHOWERS AND
STORMS TO BE MONDAY AFTERNOON AND EVENING. IT IS STILL TOO EARLY TO
PIN DOWN SEVERE POTENTIAL BUT WILL HAVE TO MONITOR THE EVOLUTION OF
THE POSSIBLE JETLET AS A FEW STORMS MAY HAVE THE POTENTIAL TO BE ON
THE STRONGER SIDE.
TUESDAY THROUGH THURSDAY...PERHAPS SOME LOW CLOUDS AROUND TO START
OFF TUESDAY (THOUGH OVER LAKE INSTABILITY IS MUCH LESS THAN OUR
LATEST GO AROUND). OTHERWISE...RENEWED RIDGING AT THE SURFACE AND
ALOFT SHOULD LEAD TO ANOTHER STRETCH OF FINE LATE SPRING WEATHER.
HIGHS RANGING FROM THE MIDDLE 60S NORTH TO THE MIDDLE 70S SOUTH AND
LOWS IN THE MIDDLE 40S TO MIDDLE 50S (WHICH IS ALMOST PERFECT
SLEEPING WEATHER IF YOU ASK ME).
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 630 AM EDT FRI MAY 23 2014
SUMMARY: HIGH PRESSURE BUILDS INTO THE GREAT LAKES DURING THE
UPCOMING FORECAST PERIOD WITH IMPROVING FLYING CONDITIONS EXPECTED.
RESTRICTIONS: ONGOING STRATUS WILL BRING GENERALLY MVFR RESTRICTIONS
THROUGH MID MORNING BEFORE SCATTERING OUT FOR THE AFTERNOON.
SCATTERED VFR CLOUDINESS FOR THE AFTERNOON WILL GIVE WAY TO
MOSTLY CLEAR SKIES TONIGHT /OUTSIDE OF SOME SCATTERED MID-UPPER
LEVEL CLOUDINESS NORTH/.
WINDS: NORTHWEST WINDS WILL STRENGTHEN TO 10G18KTS FOR THE DAY TODAY
BEFORE DIMINISHING TO CALM/LIGHT-VARIABLE TONIGHT.
LLWS: NO THREAT THIS CYCLE.
THUNDER: NO THREAT THIS CYCLE.
&&
.MARINE...
ISSUED AT 332 AM EDT FRI MAY 23 2014
SUMMARY: HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES REGION TODAY
AND TONIGHT...WITH NORTHWESTERLY WINDS GRADUALLY DECREASING. HIGH
PRESSURE WILL REMAIN OVERHEAD THROUGH SATURDAY BEFORE SHIFTING
SOUTH AND EAST OF THE REGION BY SUNDAY WITH LOW PRESSURE ARRIVING
SUNDAY NIGHT/MONDAY...WITH A ROUND OF SOUTHWEST WINDS BEFORE WINDS
SHIFT AGAIN TO THE NORTHWEST BY THE MIDDLE OF NEXT WEEK.
HEADLINES: MARGINAL SMALL CRAFT CONDITIONS POSSIBLE NEAR PRESQUE
ISLE FOR A TIME TODAY...OTHERWISE...HEADLINE FREE CONDITIONS LOOK TO
BE IN STORE THROUGH THE UPCOMING WEEKEND.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
SYNOPSIS...AS
SHORT TERM...ARNOTT
LONG TERM...AS
AVIATION...ARNOTT
MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
641 AM CDT FRI MAY 23 2014
.SYNOPSIS...
ISSUED AT 300 AM CDT FRI MAY 23 2014
A MESOSCALE VORTICITY CENTER APPEARS LOCATED NEAR LAMAR CO FROM
EARLIER MCS WHICH DEVELOPED AND MOVED NORTHEAST FROM EASTERN NEW
MEXICO. THE LEADING EDGE OF THIS CONVECTION HAS PERSISTED ACROSS
NORTHWEST KANSAS AND SOUTHWEST NEBRASKA WITH A SLOW PROPAGATION TO
THE NORTH. DUE TO SLOW OVERALL STORM MOVEMENT...HEAVY RAINFALL
INDICATED BY RADAR FROM SERN CHASE INTO HAYES COUNTY. TEMPERATURES
ACROSS WRN NEBR RANGED IN THE UPPER 50S TO LOWER 60S WITH DEWPOINTS
IN THE MID 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CDT FRI MAY 23 2014
A CLOSED UPPER LOW WAS LOCATED IN FAR SRN CALIF EARLY THIS MORNING
WITH UPSTREAM RIDGING FROM THE LOWER MISSISSIPPI VALLEY
NORTHWESTWARD INTO WYOMING. MAIN AREA OF CONVECTION FROM WESTERN
KANSAS INTO SWRN NEBR WILL CONTINUE TO MOVE NORTH PRIOR TO 12Z. AN
APPARENT MVC NEAR LAMA CO SHOULD CONTINUED LIFT NORTHEAST TODAY
ALONG WITH A MID LEVEL DISTURBANCE. BOTH THE NAM AND GFS DEVELOP
PRECIPITATION BOTH TODAY AND TONIGHT ACROSS WRN NEBR. THE HIGHER
LIKELY POPS TODAY INTO THIS EVENING ARE PLACED ACROSS THE SOUTHEAST
PANHANDLE INTO SOUTHWEST NEBR. NORTHEAST COUNTIES SHOULD REMAIN DRY
TODAY WITH A SLIGHT CHANCE BY LATE AFTERNOON. IN ADDITION...BOTH THE
RAP AND HRRR MODELS INDICATE SHOWER AND THUNDERSTORM DEVELOPMENT
SHOULD OCCUR QUICKLY AFTER 15Z FROM SWRN NEBR INTO THE WESTERN
SANDHILLS. DUE TO WEAK DEEP LAYER SHEAR LESS THAN 20 KTS...STRONG OR
SEVERE STORMS ARE UNLIKELY. STORM MOTION TO THE NORTH AND NORTHEAST
WILL ONLY BE 10 TO 15 MPH...WITH HEAVY RAINFALL POSSIBLE WITH
TRAINING CELLS.
SKIES TO BE MOSTLY CLOUDY TODAY WITH HIGHS FROM NEAR 70 IN SWRN NEBR
TO AROUND 75 IN THE NORTHEAST WHERE A BIT MORE SUN EXPECTED.
CHANCES FOR SHOWERS AND THUNDERSTORMS FALL TO AROUND 30 PERCENT
AFTER MIDNIGHT TONIGHT...WITH SLIGHTLY BETTER CHANCES FROM CENTRAL
KANSAS INTO EASTERN NEBRASKA. WITH MAINLY CLOUDY SKIES AND DEWPOINTS
IN THE MID 50S...OVERNIGHT LOWS WILL MOSTLY RANGE IN THE UPPER 50S.
THE UPPER LEVEL LOW MEANWHILE WILL MOVE SLOWLY INTO CENTRAL ARIZONA
OVERNIGHT WITH A CONTINUED FETCH OF GULF MOISTURE FROM THE SOUTHERN
INTO THE CENTRAL PLAINS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 300 AM CDT FRI MAY 23 2014
CLOSED UPPER LEVEL LOW PRESSURE SYSTEM WILL PROGRESS VERY SLOWLY
TO THE EAST ACROSS THE SOUTHERN PLAINS THROUGH THE PERIOD. OUR
AREA WILL CONTINUE TO BE INFLUENCED FROM THE SYSTEM THROUGH AT
LEAST TUESDAY...WITH SCATTERED SHOWERS AND THUNDERSTORMS. PLENTY
OF GULF MOISTURE WILL BE IN PLACE SO SOME HEAVY RAIN IS POSSIBLE
WHERE STORMS DEVELOP. OVERALL SEVERE THREAT IS LOW DUE TO WEAK
WINDS ALOFT...BUT THIS WILL AID IN THE POSSIBILITY OF HEAVY
RAINFALL DUE TO SLOW MOVING STORMS. COVERAGE WILL BE
SCATTERED...AS NO REAL BOUNDARY TO FOCUS CONVECTION ON. THE
EXCEPTION WILL BE SUNDAY AFTERNOON AND EVENING...WHEN A WEAK COLD
FRONT WILL SAG INTO NORTHERN NEBRASKA. MAY SEE A BIT MORE COVERAGE
OF STORMS INVOF OF THE FRONT. WILL CONTINUE TO BLANKET THE AREA
WITH 30 POPS FOR MUCH OF THE WEEKEND...BUT WILL HAVE A SLIGHTLY
HIGHER 40 POP ACROSS THE NORTH SUNDAY NEAR THE FRONT.
WITH THE GULF MOISTURE WELL ESTABLISHED ACROSS THE
PLAINS...TEMPERATURES WILL BE MILD. THERE WILL BE LOW STRATUS
CLOUDS AROUND AT TIMES...BUT ALL MODELS INSIST THAT THERE WILL BE
AT LEAST SOME SUNSHINE EACH DAY THROUGH THE MEMORIAL DAY WEEKEND.
SHOULD SEE HIGHS IN THE 70S SATURDAY...AND WITH POSSIBLY MORE
SUNSHINE SUNDAY...HIGHS COULD REACH AROUND 80. LITTLE CHANGE IN
TEMPERATURES INTO MOST OF NEXT WEEK...WITH HIGHS UPPER 70S TO
LOWER 80S. LOWS WILL BE MILD...IN THE MID 50S TO LOWER 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 641 AM CDT FRI MAY 23 2014
MVFR CEILINGS NEAR OVC015 CONTINUE AT KLBF AND SHOULD PERSIST
TODAY. SHOWERS AND THUNDERSTORMS SHOULD GRADUALLY MOVE INTO THE
KLBF TERMINAL AFTER 15Z WITH OFF AND ON SHOWERS THROUGH THE DAY.
VFR CONDITIONS FORECAST AT KVTN...WITH PROBABILITY TOO LOW TO
INCLUDE MENTION FOR SHOWERS ATTM.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...TAYLOR
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
821 AM PDT FRI MAY 23 2014
.SYNOPSIS...A BROAD UPPER LEVEL LOW WILL SLOWLY MOVE EAST ACROSS
ARIZONA THROUGH THE WEEKEND...AND SLIGHT CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL PERSIST IN THE MOJAVE DESERT AND SOUTHERN GREAT
BASIN. TEMPERATURES WILL WARM A FEW DEGREES EACH DAY...REACHING WELL
ABOVE NORMAL BY MEMORIAL DAY.
&&
.UPDATE...HAVE UPDATED THE SKY/POP/QPF/WX GRIDS TO INCREASE CHANCES
FOR PRECIP...PRIMARILY FOR NORTHERN MOHAVE COUNTY. ONGOING
CONVECTION OVER COCONINO COUNTY IS CURRENTLY WEAKENING...BUT MAY
INCREASE AGAIN AFTER CROSSING THE RIVER. I COOLED HIGH TEMPS AND
RAISED DEWPOINTS IN THIS AREA FOR THE AFTERNOON. I ALSO BOOSTED POPS
OVER PORTIONS OF SAN BERNARDINO COUNTY. CONVECTION THERE SHOULD BE
A BIT MORE ISOLATED THAN IT WAS YESTERDAY...BUT A FEW SHOWERS OR
THUNDERSTORMS WILL BE POSSIBLE.
LOCAL HIGH-RES MODELS AND THE HRRR ARE POINTING TO THE POTENTIAL
FOR SOME MODEST OUTFLOW WINDS PUSHING WEST FROM NORTHERN MOHAVE AND
SOUTHERN LINCOLN COUNTIES TOWARDS THE LAS VEGAS VALLEY BY LATE
AFTERNOON/EVENING. AT THE MOMENT HAVE NOT ALTERED THE WIND GRIDS
AND WILL MONITOR CONVECTIVE ACTIVITY.
&&
.AVIATION...FOR MCCARRAN...NORTHEAST WINDS WILL AFFECT THE TERMINAL
AGAIN FRIDAY AND SATURDAY AFTERNOONS...BUT SHOULD REMAIN BELOW 10
KNOTS ABOUT 80 TO 90 PERCENT OF THE TIME. A THUNDERSTORM MAY DEVELOP
OVER THE NEARBY MOUNTAINS THIS AFTERNOON...BUT WILL LIKELY STAY OUT
OF THE VALLEY. THUNDERSTORMS MAY ALSO AFFECT THE PEACH
SPRINGS...MORMON MESA...AND DAGGETT APPROACH CORRIDORS. THERE WILL
ALSO BE A SLIGHT CHANCE OF OUTFLOW WINDS FROM THUNDERSTORM
ACTIVITY IMPACTING THE TERMINAL LATER THIS AFTERNOON/EVENING. FOR
SATURDAY...THUNDERSTORM CHANCES SHIFT EAST AND SHOULD BE LIMITED TO
THE PEACH SPRINGS AND MORMON MESA APPROACH CORRIDORS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...THUNDERSTORM CHANCES THIS AFTERNOON AND EVENING WILL BE
HIGHEST EAST OF A LINE FROM BARSTOW TO MOUNT CHARLESTON TO RACHEL.
FOR SATURDAY...THE BEST CHANCES WILL BE LIMITED TO MOHAVE AND
EASTERN LINCOLN COUNTIES. THE MAIN CONCERNS WITH STORMS EACH DAY
WILL BE ERRATIC GUSTY WINDS AND MOUNTAIN OBSCURATION.
&&
.PREV DISCUSSION...
ISSUED 227 AM PDT FRI MAY 23 2014
.SHORT TERM...THROUGH SUNDAY NIGHT...SATELLITE LOOP SHOWED UPPER LOW
SPINNING OVER SAN BERNARDINO COUNTY EARLY THIS MORNING. MOST SHOWERS
HAD DIED OUT DURING THE EVENING WITH THE LOSS OF HEATING. SURFACE
OBS SHOWED LOCALLY BREEZY CONDITIONS AND SEASONABLE TEMPERATURES.
THE LOW WILL SLOWLY WOBBLE EAST INTO ARIZONA TODAY AND MEANDER
AROUND THE FOUR CORNERS OVER THE WEEKEND. AFTERNOON THUNDERSTORM
CHANCES WILL CONTINUE THROUGH THE WEEKEND...AND PINPOINTING THE BEST
CHANCES WILL BE THE MAIN CHALLENGE. LIFTED INDEX FORECASTS FROM
YESTERDAY SEEMED TO DO A REASONABLE JOB...AND THEY SUGGEST THE BEST
CHANCES WOULD BE SOUTH AND WEST OF LAS VEGAS TODAY...FARTHER EAST ON
SATURDAY...THEN MAINLY IN THE SIERRA ON SUNDAY. /UPDATE...THE 06Z
NAM12 RUN SHOWS MORE INSTABILITY IN AN ARC FROM THE SIERRA ACROSS
THE SOUTHERN GREAT BASIN AND DOWN TO MOHAVE COUNTY ON SUNDAY...AND
IF THIS IS PRESENT IN THE 12Z RUNS...DAY SHIFT WILL NEED TO CONSIDER
INCREASING POPS./ WINDS WILL NOT BE A CONCERN EXCEPT FOR NEAR
THUNDERSTORMS...AND TEMPERATURES WILL CLIMB A FEW DEGREES EACH DAY
AS THE LOW MOVES AWAY AND HEIGHTS RISE AS POSITIVELY TILTED RIDGING
NOSES IN FROM THE PACIFIC.
.LONG TERM...MEMORIAL DAY THROUGH FRIDAY NIGHT.
A TROUGH IN THE MID AND UPPER LEVELS IS EXPECTED TO GRADUALLY DIG
SOUTH THROUGH THE WEEK ALONG THE WEST COAST, MAINLY AS PIECES OF
ENERGY WORK THROUGH THE TROUGH ACROSS THE PAC NW AND NORCAL. THIS
WILL KEEP OUR AREA IN A RELATIVELY MOISTURE STARVED SOUTHWEST FLOW
PATTERN THAT WILL RESULT IN A DRY FORECAST. MEMORIAL DAY AND TUESDAY
WILL BE THE WARMEST DAYS WITH TEMPS GRADUALLY FALLING A FEW DEGREES
EACH DAY AS HEIGHTS LOWER AND COOLER AIR MOVES IN ALOFT. TEMPS WERE
MAINLY A BLEND OF FORECAST SOUNDINGS BASED OFF THE GFS AND ECMWF AS
WELL AS STATISTICAL GUIDANCE AND SOME BIAS-CORRECTED CONS MODEL
GUIDANCE. THE CORE OF THE STRONGEST WINDS ASSOCIATED WITH THE JET
STREAM SHOULD REMAIN FAR ENOUGH TO OUR NORTH, HOWEVER, EACH DAY AS
THE DIURNAL TRENDS FAVOR SOUTHWEST WINDS SETTING UP, WE SHOULD SEE
LOCALLY BREEZY TO WINDY CONDITIONS IN THE AFTERNOON AND EVENING,
ESPECIALLY TOWARD THE END OF THE WEEK AS THE TROUGH DIGS FURTHER
SOUTH. THIS COULD FURTHER ENHANCE COOLING IN THE SOUTHWEST CWFA AS
THE MARINE LAYER DEEPENS ALONG THE COAST OF SOCAL AND SOME MARINE
AIR TRIES TO OOZE THROUGH THE COASTAL PASSES INTO THE HIGH DESERT.
&&
.VEF WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
AZ...NONE.
CA...NONE.
&&
$$
UPDATE/AVIATION...WOLCOTT
PREV DISCUSSION...MORGAN/STACHELSKI
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1025 AM CDT FRI MAY 23 2014
.UPDATE...
ISSUED AT 1025 AM CDT FRI MAY 23 2014
ISOLATED CLUSTER OF SHOWERS AND THUNDERSTORMS ALONG THE ND/SD
BORDER HAS DISSIPATED AND/OR MOVED INTO NORTHEAST SD. LATEST RAP
AND TO A LESSER EXTENT THE HRRR SHOWS SOME RE-DEVELOPMENT OF SOME
ISOLATED CONVECTION THIS AFTERNOON ACROSS SOUTHEAST ND ALONG LOW-
LEVEL CAPE GRADIENT WITH INSTABILITY INCREASING UP TO 1500 J/KG.
OVERALL FORCING IS WEAK...BUT THERE IS A SHORT WAVE RIDING THE
RIDGE THROUGH NORTH CENTRAL ND THAT COULD PRODUCE SOME LIFT FOR
ADDITIONAL AFTERNOON CONVECTION. ADDED 20 POPS ACROSS SOUTHEAST ND
THIS AFTERNOON FOR THIS POTENTIAL. OTHERWISE...UPDATED HOURLY
TEMPERATURES/SKY COVER/WINDS TO MATCH LATEST OBSERVATIONS. REST OF
FORECAST IN GOOD SHAPE WITH NO MAJOR ADJUSTMENTS NEEDED.
UPDATE ISSUED AT 641 AM CDT FRI MAY 23 2014
WEAK ISOLATED ELEVATED CONVECTION HAVING A TOUGH TIME WORKING EAST
INTO THE FORECAST AREA EARLY THIS MORNING. ANY STORMS WHICH
PROPAGATE EAST WILL MEET WITH AN INCREASINGLY DRY AND STABLE
AIRMASS. SLOWED UP EASTWARD PROGRESS WITH POPS OTHERWISE FORECAST
OK.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 312 AM CDT FRI MAY 23 2014
SHORT TERM CHALLENGES WILL BE LOW END COVERAGE PCPN CHANCES AND
TEMPERATURES. MODELS OVERALL IN FAIR AGREEMENT AND WILL USE
PERSISTENCE AND MODEL BLEND FOR FORECAST.
IN THE NEAR TERM WILL BE MONITORING ELEVATED CONVECTION ACROSS
THE CENTRAL DAKOTAS ASSOCIATED WITH WARM ADVECTION AND MODEST
850MB SPEED CONVERGENCE. MOST MODELS PICKING UP ON THIS
DEVELOPMENT HOWEVER HOW FAR EAST CONVECTION CAN GET IN QUESTION.
SURFACE HIGH PRESSURE TO REMAIN OVER MN/WESTERN GREAT LAKES AND
ASSOCIATED AIRMASS PRETTY DRY AND STABLE SO WOULD EXPECT ANY
CONVECTION TO WEAKEN AS IT PROPAGATES FARTHER EAST INTO THE FA.
WILL MAINTAIN SOME LOW END CHANCES ACROSS THE SW FORECAST AREA FOR
NOW AND ADJUST IF NEEDED. OTHERWISE MID LEVEL RIDGE TO BUILD
ACROSS THE N CENTRAL US WITH THE RIDGE AXIS OVER THE FA THROUGH
FRIDAY. STEADY WARM ADVECTION TODAY WITH SOUTH BREEZES AND WHILE
SOME CLOUD COVER FROM CONVECTIVE DEBRIS MAY BE AROUND THIS MORNING
OVERALL SHOULD SEE TEMPERATURES CLIMB WELL ABOVE AVERAGE.
SOME INSTABILITY AND CAPE WORK INTO THE WESTERN FA THIS AFTERNOON
INTO TONIGHT ALONG WITH PRECIPITABLE H2O VALUES INCREASING TO AN
INCH OR BETTER. MID LEVEL SUPPORT/SHEAR LOOKS WEAK AND NOT REALLY
SEEING MUCH FOR ANY LOW LEVEL CONVERGENCE OTHER THAN SOME WEAK
SPEED CONVERGENCE AROUND 850MB. ANY PCPN WHICH DEVELOPS TO
PROPAGATE NE SO WILL MAINTAIN CURRENT LOW END POPS. COLUMN WARM
AND WITH SOME MIXING HOLDING UP OVERNIGHT WILL BE A MILD NIGHT.
BRUNT OF SATURDAY SHOULD BE DRY. COULD SEE SOME RESIDUAL
CONVECTION SATURDAY MORNING ACROSS THE NORTH HOWEVER CONFIDENCE
NOT HIGH ENOUGH TO WARRANT POPS. BY MID/LATE AFTERNOON AIRMASS
AGAIN DESTABILIZES HOWEVER WITH LACK OF FORCING AND LOW LEVEL
CONVERGENCE NOT A GREAT DEAL OF CONFIDENCE WITH CONVECTION
POTENTIAL/COVERAGE.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 312 AM CDT FRI MAY 23 2014
SURFACE FRONTAL BOUNDARY CROSSES WESTERN DAKOTAS SATURDAY NIGHT.
ALONG AND AHEAD OF BOUNDARY SEEMS BEST POTENTIAL FOR CONVECTION
AND WILL MAINTAIN HIGHER POPS ACROSS THE WESTERN FA.
FRONT CROSSES FA SUNDAY/SUNDAY EVENING AND THESE PERIODS LOOK LIKE
THE BEST POTENTIAL FOR CONVECTION DURING THE HOLIDAY WEEKEND.
WILL BROAD BRUSH FA WITH LIKELY POPS AS MODELS HAVING SOME
DIFFERENCES WITH TIMING OF FROPA. BASED ON CONVECTIVE PARAMETERS
SEVERE THREAT LOOKS MARGINAL. THERMAL RIDGE AXIS WILL BE OVER FA
HOWEVER CLOUDS WILL LIKELY TEMPER MAXIMUM TEMPERATURES.
MEMORIAL DAY LOOKS DRY BUT BREEZY AND COOLER AS HIGH PRESSURE
BUILDS INTO THE FA.
MONDAY-THURSDAY...A CONTINUED WARM PATTERN IS EXPECTED THROUGH THE
PERIOD. THE 00Z GFS/ECMWF INDICATE MID/UPPER RIDGING WILL RE-ASSERT
ITSELF DURING THE MID-WEEK TIME FRAME OVER THE CENTRAL CONUS
FOLLOWING THE PASSAGE OF THE EARLY WEEK SHORTWAVE SUNDAY INTO
MONDAY...WITH UPPER TROUGHING DEVELOPING ACROSS THE PAC NORTHWEST.
THUS...AFTER PERHAPS SLIGHTLY COOLER TEMPS ON MONDAY...HIGHS SHOULD
BE WELL INTO THE 70S...IF NOT 80S FOR MID-WEEK. IF THIS RELATIVELY
AMPLIFIED PATTERN VERIFIES...LARGE SCALE FORCING WOULD BE WEAK
THROUGH MOST OF THE PERIOD WITH THE STRONGER WESTERLIES TO THE NORTH
AND WEST...WHERE THE BETTER PRECIP CHANCES WOULD BE. ANY WEAKER
DISTURBANCES AND ASSOCIATED FOCUSED LOW-LEVEL WARM ADVECTION COULD
LEAD TO POCKETS OF CONVECTION. WITH THE UNCERTAINTY OF THE
ORIENTATION/AMPLIFICATION OF THE LONG WAVE PATTERN AND EMBEDDED
IMPULSES...WILL KEEP SOME SLIGHT/CHANCE POPS TUE-THU OVER PORTIONS
OF THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 641 AM CDT FRI MAY 23 2014
VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD. ISOLATED
CONVECTION CONTINUES JUST TO THE WEST OF THE FORECAST AREA HOWEVER
NOT EXPECTING ANY OF THIS TO AFFECT TAF SITES. WILL SEE SOME SCT-
BKN MID CLOUD THIS MORNING OVER EASTERN ND ASSOCIATED WITH
CONVECTION. BY AFTERNOON EXPECT ONLY SCT CLOUDS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...ROGERS
SHORT TERM...VOELKER
LONG TERM...MAKOWSKI/VOELKER
AVIATION...VOELKER
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1046 AM EDT FRI MAY 23 2014
.DISCUSSION...
THE POTENTIAL FOR AFTERNOON CONVECTION SHIFTS TO OUR SOUTHERN
COUNTIES THIS AFTERNOON AS AN OUTFLOW BOUNDARY FROM THE AM STORMS
APPEARS TO BE SITUATED NEAR THE GA BORDER. THE RUC AND HRRR DEVELOP
SCATTERED CONVECTION IN THE SOUTHERN VALLEY AROUND 19Z. THE CAP IN
THAT AREA IS WEAKER TODAY COMPARED TO YESTERDAY...BUT THERE IS ALSO
MUCH LESS CAPE TODAY...SO THE SEVERE POTENTIAL LOOKS LOW. THE
CURRENT FORECAST OF CHANCE POPS IN THAT AREA THIS AFTERNOON LOOKS
ON TRACK...WITH NO POPS FROM KNOXVILLE NORTH WHERE STABILITY IS
GREATER. TEMPERATURES LOOK ON TRACK AS WELL...SO NO UPDATE IS
PLANNED.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS TUCSON AZ
121 PM MST FRI MAY 23 2014
.SYNOPSIS...A SLOW MOVING LOW PRESSURE SYSTEM WILL GRADUALLY MOVE
ACROSS THE AREA THROUGH SUNDAY. AS A RESULT OF THE SLOW MOVEMENT
GUSTY WINDS WILL OCCUR AGAIN MAINLY EAST OF TUCSON. THE STORM WILL
ALSO GENERATE SOME THUNDERSTORMS AROUND THE AREA THROUGH SATURDAY
WITH A FOCUS OVER HIGHER TERRAIN AND DURING THE AFTERNOON AND
EARLY EVENING HOURS. DRIER AND WARMER TEMPERATURES WILL RETURN TO
THE REGION NEXT WEEK AFTER THE LOW EXITS THE SOUTHWEST.
&&
.DISCUSSION...AFTERNOON CU FIELD HAS DEVELOPED ACROSS THE WESTERN
DESERTS AND EAST OF TUCSON. THE MOST AGITATED CU AS BEEN ACROSS
THE NERN ZONES WHERE AS OF 20Z SOME DESCENT CONVECTION IS
OCCURRING. THIS WILL CONTINUE TO THE BE THE PRIME SPOT FOR STORM
DEVELOPMENT THIS EVENING. STILL...NOT EXPECTING MUCH IN THE WAY OF
MEASURABLE PRECIP OUTSIDE OF THE HIGHER TERRAIN AS BASES OF THE
STORMS WILL REMAIN HIGH WITH DRY LOWER LEVELS. THAT BEING
SAID...THE SECONDARY CU FIELD OUT WEST WILL HAVE PLENTY OF UPPER
LEVEL SUPPORT BEING RIGHT UNDER THE SLOW MOVING LOW. POINT
SOUNDINGS ACROSS THAT AREA SHOW SLIGHTLY BETTER UPPER LEVEL
INSTABILITY AS WELL...SO THESE STORMS MAY BE SLIGHTLY BETTER RAIN
PRODUCERS. STILL...HAVE CONTINUED THE MAINLY DRY QPFS ACROSS THE
AREA TONIGHT.
SATURDAY AND SUNDAY AS THE LOW MEANDERS ACROSS THE STATE THE FOCUS
OF STORM DEVELOPMENT WILL BE ACROSS THE HIGHER TERRAIN NE OF
TUCSON. THAT BEING SAID...TOMORROW AFTERNOON WITH THE CENTER OF
THE LOW GENERALLY OVERHEAD HAVE NUDGED POPS UP ACROSS TUCSON TO MT
GRAHAM. AFTER SUNSET THOUGH THE FOCUS OF PRECIP WILL BE ACROSS THE
AFOREMENTIONED AREA.
THE LAST FEW RUNS HAVE SLOWED THE PROGRESSION OF THE LOW. THIS
WILL ALLOW FOR ADDITIONAL MOISTURE TO RAP AROUND THE LOW SUNDAY
NIGHT AND INTO MONDAY. THIS WINDOW LOOKS TO BE THE BEST SHOT FOR
WETTING RAINS. THEREFORE...HAVE UPPED POPS FOR SUNDAY AFTERNOON
AND EVENING. ALSO CONTINUED THE SLIGHT CHANCE POPS MONDAY MORNING.
THEN TUESDAY INTO THURSDAY SHORTWAVE RIDGING WILL BUILD IN THOUGH
IT WILL BE SHORT LIVED AS ANOTHER UPPER LOW WILL DIG SOUTHWARD
INTO THE SWRN CONUS. HAVE TRENDED THIS PACKAGE SLIGHTLY DRIER IN
THE EXTENDED THAN PREVIOUS FORECAST AS MOISTURE LOOKS TO BE MORE
ACROSS NEW MEXICO. THAT BEING SAID...MID RANGE GUIDANCE IS HINTING
AT SMALL SHORTWAVE LOW RIDING AROUND THE RIDGE PRIOR TO THE MAIN
TROUGH. THIS WOULD CONTRIBUTE AT LEAST SOME ADDITIONAL MOISTURE
AHEAD OF THE MAIN SYSTEM. NEVERTHELESS...THERE REMAINS ENOUGH
UNCERTAINTY IN THE EXTENDED FOR MUCH MORE THAN LOW END SLIGHT
CHANCE POPS.
&&
.AVIATION...VALID THRU 25/00Z.
AN UPPER LOW IS NOW ACROSS WESTERN ARIZONA MOVING SLOWLY EASTWARD.
SCT-BKN CLOUDS 10-12K FT MAINLY ACROSS GRAHAM/GREENLEE/COCHISE
COUNTIES WITH ISOLD -TSRA ESPECIALLY NORTH AND EAST OF KSAD THRU
24/03Z. GUSTY SW WINDS INTO THIS EVENING...ESPECIALLY NEAR KDUG AND
ALSO NEAR -TSRA...WITH GUSTS GREATER THAN 30 KTS POSSIBLE. WINDS
WILL GRADUALLY DIMINISH AFTER 24/03Z BECOMING LIGHT AND LESS THAN 10
KT OVERNIGHT INTO SATURDAY MORNING. ANOTHER ROUND OF ISOLD -TSRA
EXPECTED SATURDAY AFTERNOON MAINLY FROM KTUS EASTWARD WITH SOME
GUSTY WINDS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...BREEZY TO WINDY CONDITIONS WILL CONTINUE INTO THIS
EVENING ESPECIALLY EAST OF TUCSON AS AN UPPER LOW IS LOCATED ACROSS
WESTERN ARIZONA. THERE WILL BE SOME ISOLATED SHOWERS AND
THUNDERSTORMS MAINLY ACROSS GRAHAM AND GREENLEE COUNTIES INTO EARLY
THIS EVENING. AS LOWER LEVEL MOISTURE IS LIMITED...THERE WILL BE SOME DRY
LIGHTNING AS MUCH OF THE PRECIPITATION WILL REMAIN VIRGA WITH
LIMITED MEASURABLE RAINFALL. DUE TO LOW RELATIVE HUMIDITIES COMBINED WITH
GUSTY WINDS THIS AFTERNOON...A RED FLAG WARNING REMAINS IN EFFECT
FOR THE SOUTHERN THIRD OF FIRE WEATHER ZONE 152. EASTERN PORTIONS OF
151 WILL MEET CRITERIA BRIEFLY THIS AFTERNOON...BUT NOT ENOUGH TO
WARRANT A WARNING.
AS THE UPPER LOW SLOWLY MOVES EAST SATURDAY... MOISTURE WILL
GRADUALLY INCREASE WITH A BETTER CHANCE OF MEASURABLE RAINFALL.
HOWEVER...RH VALUES WILL STILL LIKELY BE ON THE LOW SIDE IN GENERAL.
THE BEST CHANCE OF PRECIPITATION WILL OCCUR FROM TUCSON EASTWARD
SATURDAY. ISOLATED DRY LIGHTNING MAY STILL BE AN ISSUE. A SLIGHT
CHANCE OF SHOWERS WILL CONTINUE INTO SUNDAY AND MONDAY MAINLY ACROSS
THE WHITE MOUNTAINS. THEREAFTER...EXPECT A PRONOUNCED WARMING TREND
SUNDAY THROUGH TUESDAY.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 7 PM MST THIS EVENING FOR AZZ152.
&&
$$
PUBLIC...MEADOWS
FIRE WEATHER/AVIATION...LADER
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
120 PM MST FRI MAY 23 2014
.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS.
&&
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL CONTINUE TO MOVING EAST ACROSS THE DESERT
SOUTHWEST BRINGING A SLIGHT CHANCE OF THUNDERSTORMS TO THE AREA
TODAY. STORM CHANCES WILL BE LIMITED MAINLY TO THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON SATURDAY. ABOVE NORMAL TEMPERATURES WILL
RETURN TO THE REGION EARLY NEXT WEEK AS HIGH PRESSURE BECOMES
REESTABLISHED TO OUR SOUTH.
&&
.DISCUSSION...
SLOW MOVING UPPER LOW NOW CENTERED NEAR BLYTHE THIS MORNING. VORT
MAXES CONTINUE TO ROTATE THROUGH THE SYSTEM. THE VORT MAX THAT WENT
THROUGH OUR AREA YESTERDAY IS NOW NEAR THE AZ/UT BORDER BUT YET
ANOTHER IS MOVING ACROSS SOUTHERN ARIZONA THIS MORNING. LATEST
MODELS SHOW ISOLATED TO SCATTERED CONVECTION DEVELOPING OVER OUR
FORECAST AREA IN LA PAZ...YUMA...AND WESTERN MARICOPA COUNTIES.
DESPITE FAVORABLE QG FORCING...MODELS ARE RELUCTANT TO DEVELOP
CONVECTION OVER SOUTHEAST ARIZONA WHICH IF IT DEVELOPED COULD ADVECT
INTO EASTERN PORTIONS OF OUR FORECAST AREA. HAD BEEN CONSIDERING AN
UP-RAMP IN POPS FOR TODAY BUT HRRR HAS TRENDED DOWNWARD IN AREAL
COVERAGE OF CONVECTION. WILL CONTINUE TO EVALUATE.
&&
.PREVIOUS DISCUSSION ISSUED 245 AM...
LATEST WV IMAGERY SHOWS THE PERSISTENT CUTOFF LOW SPINNING ACROSS
THE DESERT SOUTHWEST. SHORT-TERM MODELS ARE IN GOOD AGREEMENT THAT
THE MID-TROPOSPHERIC LOW WILL CONTINUE DRIFTING EASTWARD INTO
WESTERN AZ TODAY. ALTHOUGH VORTICITY FORCED ASCENT REMAINS
RELATIVELY STRONG AND ORGANIZED ACROSS AZ...MOISTURE WILL BE A
LIMITING FACTOR ACROSS THE FORECAST AREA WITH THE DEEPEST MOISTURE
CLEARLY LOCATED ALONG THE EASTERN FLANK OF THE LOW AND EAST OF THE
REGION. NEVERTHELESS...A PERSISTENCE FORECAST ALONG WITH SUPPORT
FROM THE LOCAL WRFS AND HRRR SUGGEST THAT ISOLATED THUNDERSTORMS ARE
POSSIBLE TODAY IN THE VICINITY OF THE MID-LEVEL COLD POOL...MAINLY
ACROSS THE LOWER DESERTS OF SOUTHWESTERN AZ. ANY STORMS THAT DO
DEVELOP WILL NOT CONTAIN MUCH RAIN. INSTEAD THE GREATER THREAT
REMAINS DRY LIGHTNING ALONG WITH LOCALLY GUSTY WINDS AND LOCALIZED
BLOWING DUST.
SUITE OF MODEL GUIDANCE INDICATES THAT THE UPPER LOW WILL CONTINUE
SLIDING EASTWARD THIS WEEKEND. HOWEVER...MODELS DIFFER ON THE
EVOLUTION OF SEVERAL SMALLER VORTICES EMBEDDED WITHIN THE LARGER
LOW. CONSEQUENTLY...DETERMINING THE EXACT THE PLACEMENT AND TIMING
OF PRECIPITATION WILL BE DIFFICULT...THOUGH THE CONSENSUS IS THAT
CONVECTION WILL LARGELY REMAIN CONFINED TO THE
CLIMATOLOGICALLY-FAVORED HIGHER TERRAIN NORTH AND EAST OF PHOENIX.
POPS ARE HIGHEST IN THESE AREAS...THOUGH ISOLATED THUNDERSTORMS IN
THE PHOENIX AREA CANNOT TOTALLY BE RULED OUT.
IN THE WAKE OF THE LOW EARLY NEXT WEEK...DRY SOUTHWESTERLY FLOW WILL
DEVELOP BETWEEN AN AREA OF LOW PRESSURE ACROSS THE PACIFIC NORTHWEST
AND A RIDGE ACROSS NORTHERN MEXICO. AFTER A PERIOD OF BELOW NORMAL
TEMPERATURES THROUGH SUNDAY...ABOVE NORMAL TEMPERATURES WILL RETURN
MONDAY AND WILL CONTINUE THROUGH NEXT WEEK. HOWEVER...LATEST
GUIDANCE INDICATES THAT TEMPERATURES WILL REMAIN WELL BELOW RECORDS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL... AND SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
WINDS EXPECTED TO REMAIN MOSTLY LIGHT AND DIURNALLY
DRIVEN...GENERALLY AROUND 10KT THROUGH THIS AFTERNOON. SUFFICIENT
MOISTURE AND INSTABILITY WILL KEEP SLIGHT CHANCE TO CHANCE OF
THUNDERSTORMS ACROSS THE REGION DURING THE DAY AND INTO THE EVENING
HOURS. THE STRONGEST STORMS...EXPECTED IN THE AFTERNOON AND EARLY
EVENING HOURS...IF THEY FORM WILL HAVE THE POTENTIAL TO PRODUCE
OUTFLOW WIND GUSTS TO 40 KT...AND AREAS OF BLOWING DUST/REDUCED
VSBYS. AREAS FOR EXPECTED ACTIVITY...ACROSS FAR WESTERN MARICOPA
COUNTY COULD SEND OUTFLOWS INTO THE PHOENIX METRO WITH REDUCED VSBYS
DUE TO DUST DURING THE AFTERNOON/EVE. SOME UNCERTAINTY AS TO TIMING
ANY OUTFLOW WINDS INTO THE PHX METRO...LEFT MENTION OUT OF THE TAFS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
SLIGHT CHANCE FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
WILL REMAIN OVER SOUTHERN GILA COUNTY AND AREAS WELL NORTH AND EAST
OF PHOENIX THROUGH MONDAY. WETTING RAINS ARE NOT LIKELY...WITH
STRONG GUSTY OUTFLOW WINDS AND LIGHTNING REMAINING THE PRIMARY
THREAT WITH STORM DEVELOPMENT. THE BEST MOISTURE AND INSTABILITY
PARAMETERS GREATLY DROP BY TUESDAY THROUGH THE WEEK...AS A RIDGE
BUILDS IN PLACE WITH WARMING AND DRYING CONDITIONS. WINDS WILL BE
MOSTLY CALM...EXCEPT IN AND AROUND THUNDERSTORM DEVELOPMENT.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ
PREVIOUS DISCUSSION...HIRSCH
AVIATION....DEWEY/NOLTE
FIRE WEATHER...DEWEY
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
955 AM MST FRI MAY 23 2014
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL CONTINUE TO MOVING EAST ACROSS THE DESERT
SOUTHWEST BRINGING A SLIGHT CHANCE OF THUNDERSTORMS TO THE AREA
TODAY. STORM CHANCES WILL BE LIMITED MAINLY TO THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON SATURDAY. ABOVE NORMAL TEMPERATURES WILL
RETURN TO THE REGION EARLY NEXT WEEK AS HIGH PRESSURE BECOMES
REESTABLISHED TO OUR SOUTH.
&&
.DISCUSSION...
SLOW MOVING UPPER LOW NOW CENTERED NEAR BLYTHE THIS MORNING. VORT
MAXES CONTINUE TO ROTATE THROUGH THE SYSTEM. THE VORT MAX THAT WENT
THROUGH OUR AREA YESTERDAY IS NOW NEAR THE AZ/UT BORDER BUT YET
ANOTHER IS MOVING ACROSS SOUTHERN ARIZONA THIS MORNING. LATEST
MODELS SHOW ISOLATED TO SCATTERED CONVECTION DEVELOPING OVER OUR
FORECAST AREA IN LA PAZ...YUMA...AND WESTERN MARICOPA COUNTIES.
DESPITE FAVORABLE QG FORCING...MODELS ARE RELUCTANT TO DEVELOP
CONVECTION OVER SOUTHEAST ARIZONA WHICH IF IT DEVELOPED COULD ADVECT
INTO EASTERN PORTIONS OF OUR FORECAST AREA. HAD BEEN CONSIDERING AN
UP-RAMP IN POPS FOR TODAY BUT HRRR HAS TRENDED DOWNWARD IN AREAL
COVERAGE OF CONVECTION. WILL CONTINUE TO EVALUATE.
&&
.PREVIOUS DISCUSSION ISSUED 245 AM...
LATEST WV IMAGERY SHOWS THE PERSISTENT CUTOFF LOW SPINNING ACROSS
THE DESERT SOUTHWEST. SHORT-TERM MODELS ARE IN GOOD AGREEMENT THAT
THE MID-TROPOSPHERIC LOW WILL CONTINUE DRIFTING EASTWARD INTO
WESTERN AZ TODAY. ALTHOUGH VORTICITY FORCED ASCENT REMAINS
RELATIVELY STRONG AND ORGANIZED ACROSS AZ...MOISTURE WILL BE A
LIMITING FACTOR ACROSS THE FORECAST AREA WITH THE DEEPEST MOISTURE
CLEARLY LOCATED ALONG THE EASTERN FLANK OF THE LOW AND EAST OF THE
REGION. NEVERTHELESS...A PERSISTENCE FORECAST ALONG WITH SUPPORT
FROM THE LOCAL WRFS AND HRRR SUGGEST THAT ISOLATED THUNDERSTORMS ARE
POSSIBLE TODAY IN THE VICINITY OF THE MID-LEVEL COLD POOL...MAINLY
ACROSS THE LOWER DESERTS OF SOUTHWESTERN AZ. ANY STORMS THAT DO
DEVELOP WILL NOT CONTAIN MUCH RAIN. INSTEAD THE GREATER THREAT
REMAINS DRY LIGHTNING ALONG WITH LOCALLY GUSTY WINDS AND LOCALIZED
BLOWING DUST.
SUITE OF MODEL GUIDANCE INDICATES THAT THE UPPER LOW WILL CONTINUE
SLIDING EASTWARD THIS WEEKEND. HOWEVER...MODELS DIFFER ON THE
EVOLUTION OF SEVERAL SMALLER VORTICES EMBEDDED WITHIN THE LARGER
LOW. CONSEQUENTLY...DETERMINING THE EXACT THE PLACEMENT AND TIMING
OF PRECIPITATION WILL BE DIFFICULT...THOUGH THE CONSENSUS IS THAT
CONVECTION WILL LARGELY REMAIN CONFINED TO THE
CLIMATOLOGICALLY-FAVORED HIGHER TERRAIN NORTH AND EAST OF PHOENIX.
POPS ARE HIGHEST IN THESE AREAS...THOUGH ISOLATED THUNDERSTORMS IN
THE PHOENIX AREA CANNOT TOTALLY BE RULED OUT.
IN THE WAKE OF THE LOW EARLY NEXT WEEK...DRY SOUTHWESTERLY FLOW WILL
DEVELOP BETWEEN AN AREA OF LOW PRESSURE ACROSS THE PACIFIC NORTHWEST
AND A RIDGE ACROSS NORTHERN MEXICO. AFTER A PERIOD OF BELOW NORMAL
TEMPERATURES THROUGH SUNDAY...ABOVE NORMAL TEMPERATURES WILL RETURN
MONDAY AND WILL CONTINUE THROUGH NEXT WEEK. HOWEVER...LATEST
GUIDANCE INDICATES THAT TEMPERATURES WILL REMAIN WELL BELOW RECORDS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL... AND SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
UPPER LEVEL LOW WILL LINGER OVER THE REGION AND SLOWLY SHIFT EAST
ACROSS SE CALIFORNIA AND INTO ARIZONA TODAY. WINDS EXPECTED
TO REMAIN LIGHT AND DIURNALLY DRIVEN...GENERALLY AROUND 10KT THROUGH
FRIDAY AFTERNOON. SUFFICIENT MOISTURE AND INSTABILITY WILL KEEP
SLIGHT CHANCE OF THUNDERSTORMS ACROSS THE REGION DURING THE DAY AND
INTO THE EVENING HOURS...THE STRONGEST STORMS IF THEY FORM WILL HAVE
THE POTENTIAL TO PRODUCE OUTFLOW WIND GUSTS TO 40 KT...AND AREAS OF
BLOWING DUST/REDUCED VSBYS. THE BEST CORRIDOR FOR MIDDAY
INITIATION/DEVELOPMENT PER HI-RES MODELS LOOKS TO BE ACROSS
SOUTHWESTERN ARIZONA...WHERE ACTIVITY AND/OR OUTFLOWS COULD BE IN
THE VICINITY OF BLYTHE NEAR 23/1800Z. ADDITIONAL ACTIVITY ACROSS FAR
WESTERN MARICOPA COUNTY COULD SEND OUTFLOWS INTO THE PHOENIX METRO
WITH REDUCED VSBYS DUE TO DUST DURING THE AFTERNOON/EVE. WITH SOME
UNCERTAINTY AS TO TIMING ANY OUTFLOW WINDS INTO THE PHX METRO...LEFT
MENTION OUT OF THE 12Z TAFS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE OVER
THE NORTHEASTERN/EASTERN ARIZONA HIGH TERRAIN SUNDAY WHILE THE
ALREADY SLOW MOVING LOW MAKES A SLOWER EXIT TO THE EAST. LATEST
FORECAST RUNS HAVE SLOWED THE EXIT OF THIS WEEKEND`S LOW PRESSURE
SYSTEM...WITH RESIDUAL TROUGH HEIGHTS LINGERING OVER THE FOUR
CORNERS INTO MONDAY. WETTING RAINS FROM STORM ACTIVITY ON SUNDAY NOT
LIKELY...WITH STRONG GUSTY OUTFLOW WINDS AND LIGHTNING REMAINING THE
PRIMARY THREATS WITH ANY STORM DEVELOPMENT. STORM CHANCES A GREATLY
REDUCED FOR MONDAY AS THE BEST MOISTURE AND INSTABILITY PROFILES
CLEAR EAST OF THE AREA...BUT SOME ADDITIONAL COOLING AND BREEZINESS
COULD BE GENERATED MONDAY WITH A SLOWER LOW EXIT. ONCE THE UPPER LOW
EXITS THE REGION...A WARMING AND DRYING TREND WILL COMMENCE
RETURNING DAYTIME TEMPS AT OR ABOVE NORMAL BY MONDAY AND CONTINUING
THROUGH MIDWEEK.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ
PREVIOUS DISCUSSION...HIRSCH
AVIATION....NOLTE/MEYERS
FIRE WEATHER...NOLTE
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
100 PM PDT FRI MAY 23 2014
.SYNOPSIS...
HIGH PRESSURE WILL GRADUALLY BUILD OVER SOUTHWEST CALIFORNIA THROUGH
THE WEEKEND. THIS WILL BRING A WARMING TREND TO THE AREA...ALTHOUGH
NIGHT AND MORNING STRATUS WILL CONTINUE TO IMPACT COASTAL AREAS. FOR
EARLY NEXT WEEK...A TROUGH WILL DEVELOP ALONG THE WEST COAST
BRINGING COOLER CONDITIONS AND A CONTINUATION OF THE COASTAL STRATUS
AND FOG.
&&
.SHORT TERM (TODAY-MON)...STARTING TO GET A FEW BUILDUPS THIS
AFTERNOON NEAR THE LA/SBD COUNTY LINE BUT OBVIOUSLY MUCH QUIETER SO
FAR THAN YESTERDAY. STILL LOOKING AT A SMALL CHANCE OF A STORM
DEVELOPING LATER THIS AFTERNOON OVER THE ERN SAN GABRIELS AS SOME
MOISTURE WRAPS AROUND THE BACK SIDE OF THE UPPER LOW OVER THE
COLORADO RIVER, THOUGH THE HRRR MODEL NOW INDICATES NO SIGNIFICANT
DEVELOPMENT.
HIGH PRESSURE NUDGING INTO THE AREA FROM THE WEST WILL BRING WARMER
AIR ALOFT, SHRINKING THE MARINE LYR BY A GOOD 1000 FT. WEB CAMS
ALONG THE CENTRAL COAST ALREADY SHOWING LOWER CLOUD BASES OFFSHORE.
THIS COULD LEAD TO SOME DENSE FOG FOR PORTIONS OF THE CENTRAL COAST
TONIGHT. INCREASING NORTHWEST FLOW WITH THE BUILDING HIGH WILL BRING
SOME GUSTY WINDS TO THE CENTRAL COAST AND SRN SBA COUNTY THIS
AFTERNOON AND EVENING BUT BELOW ADVISORY LEVELS FOR THE MOST PART.
LOW CLOUDS EXPECTED TO FILL IN ACROSS LA/VENTURA COUNTY WITH THE
STRENGTHENING INVERSION, THOUGH WITH LOWER BASES. WILL TAKE A LITTLE
LONGER TO FILL IN ACROSS SRN SBA COUNTY DUE TO THE WEAK SUNDOWNERS
THERE THIS EVENING.
REMAINDER OF THE FORECAST REMAINS LARGELY UNCHANGED FROM THE LAST
COUPLE DAYS. THE WARMING TREND WILL CONTINUE THROUGH THE WEEKEND,
PEAKING EITHER MONDAY OR TUESDAY. MARINE LYR WILL SHRINK EACH DAY
WITH LESS INLAND PUSH. WILL LIKELY REACH THE VALLEYS THROUGH SUNDAY
BUT PROBABLY NOT MONDAY. STRONG ONSHORE FLOW WILL KEEP CLOUDS
HUGGING THE COAST THROUGH THE AFTERNOON, KEEPING SOME BEACHES
OVERCAST WELL INTO THE AFTERNOON. WHILE VALLEYS WILL WARM UP INTO
THE 80S SUNDAY AND POSSIBLY NEAR 90 MONDAY, COASTAL AREAS WILL
REMAIN MOSTLY IN THE 60S TO LOWER 70S. INTERIOR SLO COUNTY WILL BE A
DAY AHEAD WITH THE WARMING BEING CLOSER TO THE RIDGE SO PLACES LIKE
PASO ROBLES WILL BE THE 90S BY SUNDAY.
.LONG TERM (TUE-FRI)...ECMWF CONTINUES TO BE A LITTLE FASTER WITH
THE TROF NEXT WEEK, MEANING A SLIGHT DIFFERENCE OF OPINION WITH
REGARD TO THE START OF THE COOLING TREND. OTHERWISE REALLY NO
SIGNIFICANT DIFFERENCES IN THE PATERN. BOTH MODELS INDICATE ABOUT
5-10 DEGREES OF COOLING FOR INLAND AREAS BY THU AND FRI WITH THE
MARINE LYR PUSHING BACK INTO THE VALLEYS.
&&
.AVIATION...23/1800Z.
MID/UPPER LEVEL RIDGE OF HIGH PRESSURE UPSTREAM WILL APPROACH THE
AREA. UPPER LEVEL STRONG NORTH WINDS WILL BECOME MODERATE AFTER
24/20Z WHILE MID LEVEL MODERATE NORTH NORTHEAST WINDS BECOME LIGHT
NORTH NORTHWEST AFTER 24/05Z. ISOLATED THUNDERSTORMS OVER THE HIGHER
TERRAIN WITH TOPS 35-40KFT WILL MOVE SOUTH AT APPROXIMATELY 20KT.
INCREASING STABILITY AFTER 24/04Z. FREEZING LEVEL WAS APPROXIMATELY
11KFT THIS MORNING WILL DIFFER BY PLUS 2KFT AFTER 24/12Z. WEAK TO
MODERATE ONSHORE PRESSURE GRADIENT THROUGH 24/06Z AND AFTER 25/20Z
OTHERWISE WEAK GRADIENT.
.KLAX...CHANCE CIGS 035 THROUGH 23/20Z. CHANCE CIGS 026 BETWEEN
24/04-24/08Z AND CHANCE CIGS 017 BETWEEN 24/08-24/20Z.
.KBUR...CHANCE CIGS 020 BETWEEN 24/09-24/11Z THEN CHANCE CIGS 014
AFTER 24/11Z.
VIRTUALLY CERTAIN - 95-100%
VERY LIKELY - 80-95%
LIKELY - 60-80%
CHANCE - 30-60%
VERY UNLIKELY - 20% OR LESS
&&
.MARINE...23/100 PM.
THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL DEVELOP IN
THE OUTER WATERS THIS AFTERNOON AND THEN PERSIST THROUGH TUESDAY.
THE ADVISORY CONDITIONS WILL LIKELY PUSH INTO THE INNER WATERS ALONG
THE SLO COAST SATURDAY. OTHERWISE A CATALINA EDDY WILL DEVELOP IN
THE LATE EVENING EACH NIGHT AND DISSIPATE BY EARLY AFTERNOON THROUGH
THE PERIOD. LOCALLY GENERATED SHORT PERIOD SEAS FROM THE NORTHWEST
AND SMALL LONG PERIOD SWELL FROM THE SOUTH WILL PERSIST.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...MW
AVIATION/MARINE...30
SYNOPSIS...SMITH
WWW.WEATHER.GOV/LOSANGELES
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
1101 AM PDT FRI MAY 23 2014
.SYNOPSIS...
HIGH PRESSURE WILL GRADUALLY BUILD OVER THE AREA THROUGH THE
WEEKEND. THIS WILL BRING A WARMING TREND TO THE AREA...ALTHOUGH
NIGHT AND MORNING STRATUS WILL CONTINUE TO IMPACT THE COASTAL AREAS.
FOR EARLY NEXT WEEK...A TROUGH WILL DEVELOP ALONG THE WEST COAST
BRINGING COOLER CONDITIONS...AND A CONTINUATION OF THE COASTAL
STRATUS AND FOG.
&&
.SHORT TERM (TODAY-SUN)...MAIN FORECAST CHALLENGE TODAY IS THE
POTENTIAL FOR AFTERNOON THUNDERSTORMS OVER THE EASTERN SAN GABRIELS.
MODELS CONTINUE TO ADVERTISE LI`S AROUND -5 THERE, BUT MOST OF THE
OTHER PARAMETERS ARE LESS FAVORABLE THAN YESTERDAY. BUFR SOUNDINGS
FROM THE AV SHOW A FAIR AMOUNT OF WARMING FROM THE SURFACE UP TO 15K
FT, YIELDING LESS AVAILABLE CAPE. LAST COUPLE HRRR RUNS HAVE
INDICATED JUST VERY LIGHT REFLECTIVITY RETURNS OVER THE EASTERN SAN
GABRIELS LATE THIS AFTERNOON AND THE NAM DOES HAVE SOME LIGHT PRECIP
JUST BARELY ACROSS THE LA/SBD COUNTY LINE. SAT IMAGERY SHOWS A
PRETTY GOOD AREA OF MOISTURE NORTH OF THE LOW CENTER IN SRN NV
MOVING THIS WAY. SO, GIVEN ALL THESE SOMEWHAT CONFLICTING FACTORS
IT`S PRUDENT TO HAVE A SLIGHT CHANCE OF THUNDER IN THERE. AT THE
VERY LEAST WE WILL SEE SOME AFTERNOON BUILDUPS AND A SHOWER OR TWO.
TEMPS TODAY MOST AREAS SHOULD BE A BIT WARMER THAN YESTERDAY,
ESPECIALLY IN THE MTNS AND AV WHERE THERE WAS SIGNIFICANT CLOUD
COVER AND SHOWERS YESTERDAY TO COOL THINGS OFF.
***FROM PREVIOUS DISCUSSION***
FOR TONIGHT THROUGH SUNDAY...FORECAST BECOMES RATHER BLAND AS THE
MAIN CHALLENGE WILL BE FIGURING OUT THE MARINE LAYER STRATUS. WITH
THE UPPER RIDGE BUILDING OVERHEAD THROUGH THE PERIOD AND ONSHORE
FLOW CONTINUING NEAR THE SURFACE...THE MARINE INVERSION SHOULD
BECOME STRONGER AND BETTER ESTABLISHED. SO...WILL ANTICIPATE A
TYPICAL LATE MAY PATTERN WITH STRATUS PUSHING INTO THE COASTAL
VALLEYS EARLY EACH MORNING...WITH THE MOST WIDESPREAD INLAND
PENETRATION EXPECTED SATURDAY MORNING. EACH AFTERNOON...THE STRATUS
SHOULD DISSIPATE NICELY ACROSS THE VALLEYS AND INLAND COASTAL PLAIN.
HOWEVER THE STRATUS WILL LIKELY LINGER ACROSS THE BEACHES EACH
AFTERNOON DUE TO THE CONTINUED MODERATE ONSHORE FLOW AND
STRENGTHENING INVERSION. AS FOR TEMPERATURES...WILL EXPECT A WARMING
TREND SATURDAY AND SUNDAY...ALTHOUGH WARMING WILL BE MUCH MORE
LIMITED ACROSS THE BEACHES.
AS FOR WINDS...WILL EXPECT TYPICAL ONSHORE WINDS THROUGH SUNDAY WITH
THE GUSTIEST WINDS ANTICIPATED ACROSS THE MOUNTAINS AND DESERTS.
THERE MAY BE A LITTLE NORTHERLY PUSH ACROSS THE MOUNTAINS IN THE
EVENING AND OVERNIGHT HOURS...BUT ANY NORTHERLY WINDS ARE EXPECTED
TO REMAIN BELOW ADVISORY THRESHOLDS.
.LONG TERM (MON-THU)...FOR THE EXTENDED...MODELS CONTINUE TO EXHIBIT
GOOD SYNOPTIC AGREEMENT. AT UPPER LEVELS...LOW MOVES INTO THE
PACIFIC NORTHWEST MONDAY/TUESDAY...FLATTENING THE RIDGE OVER THE
DISTRICT...AND A TROUGH DEEPENS ALONG THE WEST COAST WEDNESDAY AND
THURSDAY. NEAR THE SURFACE...A GENERALLY MODERATE ONSHORE FLOW WILL
CONTINUE.
FORECAST-WISE...THIS PATTERN WILL CONTINUE TO GENERATE RATHER
UNREMARKABLE WEATHER FOR THE AREA. WITH THE CONTINUED ONSHORE FLOW
AND LOWERING H5 HEIGHTS...THE MARINE INVERSION SHOULD REMAIN IN
PLACE WITH LOW CLOUDS/FOG IMPACTING THE COASTS AND VALLEYS THROUGH
THE PERIOD (WITH THE TYPICAL DAY-TO-DAY VARIATIONS IN INLAND
EXTENT). AS FOR TEMPERATURES...MONDAY WILL LIKELY BE THE WARMEST
DAY...WITH A GRADUAL COOLING TREND TUESDAY THROUGH THURSDAY.
&&
.AVIATION...23/1800Z.
MID/UPPER LEVEL RIDGE OF HIGH PRESSURE UPSTREAM WILL APPROACH THE
AREA. UPPER LEVEL STRONG NORTH WINDS WILL BECOME MODERATE AFTER
24/20Z WHILE MID LEVEL MODERATE NORTH NORTHEAST WINDS BECOME LIGHT
NORTH NORTHWEST AFTER 24/05Z. ISOLATED THUNDERSTORMS OVER THE HIGHER
TERRAIN WITH TOPS 35-40KFT WILL MOVE SOUTH AT APPROXIMATELY 20KT.
INCREASING STABILITY AFTER 24/04Z. FREEZING LEVEL WAS APPROXIMATELY
11KFT THIS MORNING WILL DIFFER BY PLUS 2KFT AFTER 24/12Z. WEAK TO
MODERATE ONSHORE PRESSURE GRADIENT THROUGH 24/06Z AND AFTER 25/20Z
OTHERWISE WEAK GRADIENT.
.KLAX...CHANCE CIGS 035 THROUGH 23/20Z. CHANCE CIGS 026 BETWEEN
24/04-24/08Z AND CHANCE CIGS 017 BETWEEN 24/08-24/20Z.
.KBUR...CHANCE CIGS 020 BETWEEN 24/09-24/11Z THEN CHANCE CIGS 014
AFTER 24/11Z.
VIRTUALLY CERTAIN - 95-100%
VERY LIKELY - 80-95%
LIKELY - 60-80%
CHANCE - 30-60%
VERY UNLIKELY - 20% OR LESS
&&
.MARINE...23/900 AM.
THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL DEVELOP IN
THE OUTER WATERS THIS AFTERNOON AND THEN PERSIST THROUGH TUESDAY.
THE ADVISORY CONDITIONS WILL LIKELY PUSH INTO THE INNER WATERS ALONG
THE SLO COAST SATURDAY. OTHERWISE A CATALINA EDDY WILL DEVELOP IN
THE LATE EVENING EACH NIGHT AND DISSIPATE BY EARLY AFTERNOON THROUGH
THE PERIOD. LOCALLY GENERATED SHORT PERIOD SEAS FROM THE NORTHWEST
AND SMALL LONG PERIOD SWELL FROM THE SOUTH WILL PERSIST.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...MW/RAT
AVIATION...30
MARINE...30
SYNOPSIS...SETO
WWW.WEATHER.GOV/LOSANGELES
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
930 AM PDT FRI MAY 23 2014
.SYNOPSIS...
HIGH PRESSURE WILL GRADUALLY BUILD OVER THE AREA THROUGH THE
WEEKEND. THIS WILL BRING A WARMING TREND TO THE AREA...ALTHOUGH
NIGHT AND MORNING STRATUS WILL CONTINUE TO IMPACT THE COASTAL AREAS.
FOR EARLY NEXT WEEK...A TROUGH WILL DEVELOP ALONG THE WEST COAST
BRINGING COOLER CONDITIONS...AND A CONTINUATION OF THE COASTAL
STRATUS AND FOG.
&&
.SHORT TERM (TODAY-SUN)...MAIN FORECAST CHALLENGE TODAY IS THE
POTENTIAL FOR AFTERNOON THUNDERSTORMS OVER THE EASTERN SAN GABRIELS.
MODELS CONTINUE TO ADVERTISE LI`S AROUND -5 THERE, BUT MOST OF THE
OTHER PARAMETERS ARE LESS FAVORABLE THAN YESTERDAY. BUFR SOUNDINGS
FROM THE AV SHOW A FAIR AMOUNT OF WARMING FROM THE SURFACE UP TO 15K
FT, YIELDING LESS AVAILABLE CAPE. LAST COUPLE HRRR RUNS HAVE
INDICATED JUST VERY LIGHT REFLECTIVITY RETURNS OVER THE EASTERN SAN
GABRIELS LATE THIS AFTERNOON AND THE NAM DOES HAVE SOME LIGHT PRECIP
JUST BARELY ACROSS THE LA/SBD COUNTY LINE. SAT IMAGERY SHOWS A
PRETTY GOOD AREA OF MOISTURE NORTH OF THE LOW CENTER IN SRN NV
MOVING THIS WAY. SO, GIVEN ALL THESE SOMEWHAT CONFLICTING FACTORS
IT`S PRUDENT TO HAVE A SLIGHT CHANCE OF THUNDER IN THERE. AT THE
VERY LEAST WE WILL SEE SOME AFTERNOON BUILDUPS AND A SHOWER OR TWO.
TEMPS TODAY MOST AREAS SHOULD BE A BIT WARMER THAN YESTERDAY,
ESPECIALLY IN THE MTNS AND AV WHERE THERE WAS SIGNIFICANT CLOUD
COVER AND SHOWERS YESTERDAY TO COOL THINGS OFF.
***FROM PREVIOUS DISCUSSION***
FOR TONIGHT THROUGH SUNDAY...FORECAST BECOMES RATHER BLAND AS THE
MAIN CHALLENGE WILL BE FIGURING OUT THE MARINE LAYER STRATUS. WITH
THE UPPER RIDGE BUILDING OVERHEAD THROUGH THE PERIOD AND ONSHORE
FLOW CONTINUING NEAR THE SURFACE...THE MARINE INVERSION SHOULD
BECOME STRONGER AND BETTER ESTABLISHED. SO...WILL ANTICIPATE A
TYPICAL LATE MAY PATTERN WITH STRATUS PUSHING INTO THE COASTAL
VALLEYS EARLY EACH MORNING...WITH THE MOST WIDESPREAD INLAND
PENETRATION EXPECTED SATURDAY MORNING. EACH AFTERNOON...THE STRATUS
SHOULD DISSIPATE NICELY ACROSS THE VALLEYS AND INLAND COASTAL PLAIN.
HOWEVER THE STRATUS WILL LIKELY LINGER ACROSS THE BEACHES EACH
AFTERNOON DUE TO THE CONTINUED MODERATE ONSHORE FLOW AND
STRENGTHENING INVERSION. AS FOR TEMPERATURES...WILL EXPECT A WARMING
TREND SATURDAY AND SUNDAY...ALTHOUGH WARMING WILL BE MUCH MORE
LIMITED ACROSS THE BEACHES.
AS FOR WINDS...WILL EXPECT TYPICAL ONSHORE WINDS THROUGH SUNDAY WITH
THE GUSTIEST WINDS ANTICIPATED ACROSS THE MOUNTAINS AND DESERTS.
THERE MAY BE A LITTLE NORTHERLY PUSH ACROSS THE MOUNTAINS IN THE
EVENING AND OVERNIGHT HOURS...BUT ANY NORTHERLY WINDS ARE EXPECTED
TO REMAIN BELOW ADVISORY THRESHOLDS.
.LONG TERM (MON-THU)...FOR THE EXTENDED...MODELS CONTINUE TO EXHIBIT
GOOD SYNOPTIC AGREEMENT. AT UPPER LEVELS...LOW MOVES INTO THE
PACIFIC NORTHWEST MONDAY/TUESDAY...FLATTENING THE RIDGE OVER THE
DISTRICT...AND A TROUGH DEEPENS ALONG THE WEST COAST WEDNESDAY AND
THURSDAY. NEAR THE SURFACE...A GENERALLY MODERATE ONSHORE FLOW WILL
CONTINUE.
FORECAST-WISE...THIS PATTERN WILL CONTINUE TO GENERATE RATHER
UNREMARKABLE WEATHER FOR THE AREA. WITH THE CONTINUED ONSHORE FLOW
AND LOWERING H5 HEIGHTS...THE MARINE INVERSION SHOULD REMAIN IN
PLACE WITH LOW CLOUDS/FOG IMPACTING THE COASTS AND VALLEYS THROUGH
THE PERIOD (WITH THE TYPICAL DAY-TO-DAY VARIATIONS IN INLAND
EXTENT). AS FOR TEMPERATURES...MONDAY WILL LIKELY BE THE WARMEST
DAY...WITH A GRADUAL COOLING TREND TUESDAY THROUGH THURSDAY.
&&
.AVIATION...23/12Z.
LOW TO MODERATE CONFIDENCE IN THE 12Z TAFS. THE REDUCED CONFIDENCE
IS DUE TO THE UNCERTAINTY IN THE MARINE LAYER LOCATION... TIMING...
AND EXTENT THIS MORNING AND AGAIN TONIGHT... AS WELL AS POSSIBLE
DEVELOPMENT OF SHOWERS/THUNDERSTORMS IN THE REGION THIS AFTERNOON
AND EVENING.
FOR THE COASTAL AND ADJACENT VALLEYS... COASTAL LOW CLOUDS AND FOG
HAS DEVELOPED ALONG THE COAST AND PUSHED INLAND INTO MANY ADJACENT
VALLEYS. FOR THOSE LOCATIONS WITH MARINE LAYER DEVELOPMENT THERE IS
A SIXTY PERCENT CHANCE OF THE LOW CLOUDS LINGERING UNTIL 20Z. THERE
IS AN EIGHTY PERCENT CHANCE OF VFR CONDITIONS ACROSS ALL LOCATIONS
BY MID AFTERNOON... THEN REDEVELOPMENT OF LOW CLOUDS AND FOG IS
EXPECTED IN MANY LOCATIONS AFTER 03Z.
IN THE ANTELOPE VALLEY AND SAN GABRIEL MOUNTAINS... A FIFTEEN
PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS 18Z-00Z... OTHERWISE AND
ELSEWHERE VFR CONDITIONS ARE EXPECTED FOR THE FORECAST PERIOD.
.KLAX... LOW TO MODERATE CONFIENCE IN THE 12Z TAF. COASTAL LOW
CLOUDS AND FOG HAS DEVELOPED ALONG THE COAST BUT THERE IS A GOOD
AMOUNT OF THE MARINE LAYER DRIFTING IN AND OUT OF THE KLAX AREA.
THOUGH THE CEILING MAY COME AND GO... THERE IS A SIXTY PERCENT
CHANCE OF IT LINGERING IN THE AREA UNTIL 20Z... FOLLOWED BY VFR
CONDITIONS THROUGH THE DAY... THEN REDEVELOPMENT OF LOW CEILINGS
AFTER 12Z.
.KBUR...MODERATE CONFIDENCE IN THE 12Z TAF. THE REDUCED CONFIDENCE
IS DUE TO THE UNCERTAINTY OF THE MARINE LAYER REMAINING IN THE KBUR
AREA THROUGH 17Z THOUGH THERE IS A TWENTY FIVE PERCENT CHANCE OF THE
LOW CLOUDS LINGERING UNTIL 20Z. VFR CONDITIONS ARE EXPECTED BY
MIDDAY AND CONTINUING INTO THE OVERNIGHT HOURS AFTER WHICH THERE IS
A SIXTY PERCENT CHANCE OF LOW CLOUDS REDEVELOPING 08Z-10Z.
&&
.MARINE...23/900 AM.
THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL DEVELOP IN
THE OUTER WATERS THIS AFTERNOON AND THEN PERSIST THROUGH TUESDAY.
THE ADVISORY CONDITIONS WILL LIKELY PUSH INTO THE INNER WATERS ALONG
THE SLO COAST SATURDAY. OTHERWISE A CATALINA EDDY WILL DEVELOP IN
THE LATE EVENING EACH NIGHT AND DISSIPATE BY EARLY AFTERNOON THROUGH
THE PERIOD. LOCALLY GENERATED SHORT PERIOD SEAS FROM THE NORTHWEST
AND SMALL LONG PERIOD SWELL FROM THE SOUTH WILL PERSIST.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...MW/RAT
AVIATION...KJ
MARINE...30
SYNOPSIS...SETO
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS PUEBLO CO
332 PM MDT FRI MAY 23 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 332 PM MDT FRI MAY 23 2014
CURRENTLY...CONVECTION RATHER SPARSE ACROSS SOUTHERN COLORADO SO FAR
THIS AFTERNOON...THOUGH AREA OF MORE VIGOROUS TSRA WASN`T TOO FAR
AWAY OVER NRN NM. AIR MASS OVER THE REGION REMAINS MODERATELY
UNSTABLE...AND EXPECT AN INCREASE IN STORMS MOST AREAS THROUGH THE
REMAINDER OF THE AFTERNOON...AS SEVERAL WEAK BOUNDARIES EVIDENT IN
KPUX RADAR DATA MAY CONVERGE ACROSS PUEBLO/EL PASO COUNTIES 21Z-
23Z...WHICH COULD FORCE SOME NEW CONVECTION. MESOSCALE
MODELS...INCLUDING THE LATEST HRRR SUPPORT THE IDEA OF INCREASING
TSRA OVER THE PLAINS THROUGH EARLY EVENING AS WELL. CONVECTION WILL
GRADUALLY WANE BY MIDNIGHT...THOUGH WITH MODELS HINTING AT OVERNIGHT
MCS ACROSS NRN NM...WILL KEEP SOME LOW POPS GOING DURING THE
NIGHT...MAINLY ACROSS SOUTHERN ZONES.
MESOSCALE DETAILS WILL LIKELY DRIVE CONVECTION ON SATURDAY...AS SOME
SORT OF WEAKENING MCS WILL BE MOVING OUT OF NERN NM/TX PANH INTO THE
SOUTHEAST PLAINS DURING THE MORNING. DEPENDING ON STRENGTH OF
MCS...MUCH OF AREA ALONG AND EAST OF THE MOUNTAINS MAY SEE SOME
FAIRLY HEALTHY SUBSIDENCE ON THE BACK SIDE OF THE SYSTEM...WHICH
WOULD LIMIT TSRA CHANCES. STILL...WITH MODERATE INSTABILITY COVERING
MOST OF THE AREA...TOUGH TO RULE OUT STORMS JUST ABOUT ANYWHERE
DURING THE AFTERNOON. BEST PRECIP COVERAGE MAY END UP OVER THE
SOUTHWEST MOUNTAINS...WHERE STRONG DYNAMIC LIFT FROM THE UPPER LOW
COMES INTO PLAY DURING THE LATE AFTERNOON. SEVERE THREAT LOOKS LOW
ONCE AGAIN...AS DEEPER INSTABILITY AND STRONGER WIND SHEAR REMAIN TO
THE SOUTH OVER WRN TX. MAX TEMPS SHOULD STAY RELATIVELY
UNCHANGED...WITH READINGS REMAINING BELOW SEASONAL AVERAGES.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 332 PM MDT FRI MAY 23 2014
SATURDAY NIGHT THROUGH TUESDAY...A VERY UNSETTLED PATTERN IN PLACE
OVER THE HOLIDAY WEEKEND...AND THE GFS...NAM AND EC MODELS ALL SEEM
TO AGREE ON THIS. THE UPPER LOW CURRENTLY OVER SOUTHWESTERN AZ IS
EXPECTED TO SLOWLY MEANDER ALONG THE CO/NM STATE LINE SAT NIGHT
THROUGH MON...BEFORE EXITING TO THE EAST ACROSS THE OK AND TX
PANHANDLES ON TUE. A COUPLE OF THINGS TO NOTE WITH THIS SYSTEM. THE
SLOW MOVEMENT AND THE EXPECTED PLACEMENT OF THE LOW MEANS THAT THERE
IS THE POTENTIAL FOR SOME HEAVY RAINFALL IN PLACES. MODELS ALSO
INDICATE A POSSIBLE DRY SLOT FOR SUNDAY ACROSS THE PLAINS. WHERE THE
HEAVY RAINFALL OCCURS...AND WHERE AND WHEN THE DRY SLOT WILL
HAPPEN...IS VERY DIFFICULT TO PREDICT AT THIS TIME.
THEREFORE...BLANKETED MOSTLY CLOUDY TO OVERCAST SKIES FOR THE
FORECAST AREA FOR MUCH OF THE WEEKEND...AND WENT WITH AT LEAST
ISOLATED POPS FOR MUCH OF THE AREA AT ALL TIMES. MODELS INDICATE THE
DRY SLOT WILL OCCUR SUNDAY OVER THE PLAINS...SO LESSENED SKY COVER
AND LOWERED POPS THERE DURING THAT TIME FRAME.
OTHERWISE...CONVECTION WILL OCCUR IN BANDS AND EXACT AMOUNTS AND
PLACEMENT ARE IMPOSSIBLE AT THIS TIME. AS FOR TEMPS...SHOULD BE
FAIRLY WARM WITH MAX TEMPS NEAR 80 F FOR THE PLAINS EACH
DAY...THOUGH ONGOING MAX TEMP FOR TUE WILL MOST LIKELY HAVE TO BE
COOLED. AREA BURN SCARS WILL NEED TO BE MONITORED CLOSELY EACH DAY
OVER THE HOLIDAY WEEKEND.
WEDNESDAY THROUGH FRIDAY...EXTENDED MODELS INDICATE THAT THE UPPER
LOW WILL HAVE FINALLY MOVED EAST OF THE AREA AND OUT OF COLORADO BY
TUE EVE...WITH RIDGING DEVELOPING ACROSS THE DESERT SW FOR THE
SECOND HALF OF THE WEEK. THE GFS PAINTS A VERY WET PICTURE...WHILE
THE EC IS LEANING TOWARDS A MORE PROBABLE SOLUTION OF DIURNAL MT
CONVECTION AND PREDOMINANTLY DRY ELSEWHERE. THEREFORE...AMENDED THE
EXTENDED PROCEDURE POP GRIDS TO SHOW ISOLATED TO LOW END SCATTERED
POPS OVER THE MTS AND ADJACENT PLAINS EACH AFTN AND EVE...THEN DRY
WITH CLEARING SKIES OVERNIGHT. SEASONABLE TEMPS ARE FORECAST...WITH
MAX TEMPS IN THE 80S FOR THE PLAINS AND 70S FOR THE HIGH VALLEYS.
MOORE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 332 PM MDT FRI MAY 23 2014
WILL CARRY A VCTS MENTION ALL 3 TAF SITES FROM 21Z UNTIL 02Z-
04Z...AND UPDATE TAFS AS STORMS GET CLOSER TO THE TERMINALS. MAY SEE
SOME INCREASING TSRA ACTIVITY KCOS AND KPUB 22Z-23Z AS SEVERAL
OUTFLOW BOUNDARIES COLLIDE IN THE GENERAL AREA. SOME OF THE STRONGER
STORMS MAY PRODUCE BRIEF MVFR CIGS/VIS...ALONG WITH SOME SMALL HAIL
AND GUSTY WINDS. EXPECT ACTIVITY TO GRADUALLY DIMINISH TO A FEW
SHOWERS LATE EVENING AND OVERNIGHT. EARLY MORNING STRATUS HAS BEEN
RATHER PATCHY THE PAST COUPLE DAYS...SO WILL KEEP MENTION OUT OF
TAFS FOR NOW...THOUGH THERE WILL STILL BE A THREAT FOR SOME MVFR
CIGS AFTER SUNRISE SATURDAY...ESPECIALLY EAST OF I-25. LITTLE CHANGE
IN THE PATTERN ON SATURDAY...WITH SCATTERED CONVECTION MOST AREAS
ONCE AGAIN.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1006 AM MDT FRI MAY 23 2014
.UPDATE...
ISSUED AT 1006 AM MDT FRI MAY 23 2014
WATER VAPOR SHOWING A DISTURBANCE OVER NORTHEAST COLORADO AT THIS
TIME WHICH IS PRODUCING A FEW SHOWERS OVER EASTERN COLORADO. A
SECOND WAVE NEAR THE COLORADO/NEW MEXICO BORDER SHOULD MOVE NORTH
ACROSS THE AREA TODAY AND HELP TRIGGER CONVECTION. THERE IS SOME
CLEARING ALONG THE FRONT RANGE. EXPECT TEMPERATURES TO CLIMB INTO
THE 60S AND POSSIBLY LOWER 70S HERE. CLOUD COVER OVER THE EASTERN
PLAINS WILL HOLD TEMPERATURES DOWN SOME. WILL WATCH TEMPERATURE
TRENDS OVER THE NEXT HOUR OR TWO AND MAY NEED TO RAISE HIGHS A FEW
DEGREES FOR TODAY.
AIRMASS WILL REMAIN MOIST TODAY...ABOUT THE SAME AS YESTERDAY. CAPES
WILL GENERALLY BE 500-1000 J/KG. A FEW LOCATIONS THAT CLIMB INTO THE
UPPER 60S AND LOWER 70S COULD SEE CAPES TO 1500 J/KG...PER THE RAP
MODEL. THE LATEST RAP AND HRRR MODELS SHOW MOST OF THE CONVECTION
TODAY BEING ALONG THE FRONT RANGE WHERE MOST OF THE CLEARING
CURRENTLY IS. THIS MAKES SENSE AND WILL TREND POPS THIS
DIRECTION.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 308 AM MDT FRI MAY 23 2014
AN UPPER LEVEL LOW WILL SLOWLY REMAIN OVER THE SWRN US WITH MAINLY
SLY FLOW ALOFT. ONE DISTURBANCE IS ALREADY OVER SERN CO EARLY THIS
MORNING AND WILL MOVE NORTH ACROSS THE PLAINS BY MIDDAY. SHOULD SEE
SOME INCREASE IN SHOWERS ALONG WITH A FEW TSTMS OVER THE FAR ERN
PLAINS LATER THIS MORNING INTO THE EARLY AFTN HOURS AS THIS FEATURE
LIFTS NORTH. MEANWHILE ANOTHER DISTURBANCE APPEARS TO BE OVER
CENTRAL NEW MEXICO AND IS MOVING NORTH AS WELL WHICH MAY AFFECT THE
AREA BY LATE AFTN INTO THE EARLY EVENING HOURS AND ENHANCE PCPN
CHANCES. MEANWHILE APPEARS THERE WILL BE QUITE A BIT OF CLOUD
COVER TODAY WHICH WILL NOT ALLOW FOR MUCH HEATING AN LIMIT
INSTABILITY. BEST CAPES ARE FCST IN AND NR THE FOOTHILLS WITH
VALUES UP TO AROUND 1000 J/KG SO THIS WOULD BE AN AREA TO WATCH FOR
POSSIBLE HEAVIER STORM DEVELOPMENT THIS AFTN. AT THIS POINT THINGS
DO NOT LOOK FAVORABLE FOR WIDESPREAD HEAVY RAIN ALTHOUGH A FEW
STRONGER STORMS MAY PRODUCE UP TO AN INCH IN 30 MINUTES. HIGHS THIS
AFTN MAY HOLD MOSTLY IN THE 60S ACROSS NERN CO DUE TO EXTENSIVE
CLOUD COVER.
FOR TONIGHT WOULD EXPECT SHOWERS AND TSTMS TO GRADUALLY DECREASE FM
SOUTH TO NORTH AS DISTURBANCE MENTIONED ABV MOVES TO THE NORTH OF
THE AREA.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 308 AM MDT FRI MAY 23 2014
FLOW ALOFT OVER THE STATE WILL TURN FROM SOUTHERLY TO
SOUTHEASTERLY AS THE UPPER LOW MOVES FURTHER EAST INTO NEW
MEXICO. PRECIPITABLE WATER VALUES WILL BE SIMILAR IF NOT JUST
SLIGHTLY LOWER THAN TODAY. COVERAGE AND STRENGTH OF STORMS WILL BE
LESS AS CAPE VALUES WILL BE SLIGHTLY LOWER...EXCEPT OVER THE FAR
NORTHEASTERN PLAINS WHERE VALUES OF 750-1250 J/KG ARE BEING
PROJECTED. THESE STORMS WILL STILL BE SLOW MOVERS AS STEERING
WINDS ARE LIGHT...SO THE THREAT OF HEAVY RAIN AND FLOODING ISSUES
WILL REMAIN ELEVATED. A LITTLE MORE BREAKS IN THE CLOUDS WILL
ALLOW FOR SOME SLIGHTLY WARMER TEMPERATURES SATURDAY COMPARED TO
TODAY.
MODELS SHOWING SLIGHTLY DRIER AIR MOVING UP LATE SATURDAY NIGHT
INTO SUNDAY WHICH SHOULD RESULT IN LESS SHOWER AND STORM COVERAGE.
STORM MOTION SUNDAY WILL BE SLIGHTLY WEST OF NORTH AS THE UPPER
LOW CONTINUES MOVING EAST OVER NEW MEXICO. TEMPERATURES WILL BE
SIMILAR IF NOT SLIGHTLY COOLER.
THE STORMS PROGRESS EAST CONTINUES TO SLOW...SHOWN IN MODEL
TRENDS. THIS WILL KEEP SHOWERS AND THUNDERSTORMS AROUND FOR MONDAY
WITH THE POTENTIAL FOR SLIGHTLY MORE COVERAGE AS WRAPAROUND
MOISTURE MOVES IN FROM THE NORTH DOWN ACROSS WESTERN COLORADO AND
THE MOUNTAINS. AS MOUNTAIN TOP WIND BECOMES NORTHWESTERLY AS THE
LOW MOVES EAST...THIS WILL QUICKLY DRY OUT THE PLAINS.
A WARMER AND RELATIVELY DRIER PATTERN WILL PERSIST TUESDAY THROUGH
THURSDAY WITH WEAK NORTHWESTERLY FLOW ALOFT AS A RIDGE BUILDS
IN FROM THE WEST. SOME MOISTURE LEFT UNDER THE RIDGE WILL ALLOW
FOR AFTERNOON CONVECTION MAINLY OVER THE MOUNTAINS TUESDAY. THE
CHANCES WILL SPREAD OUT ON TO THE PLAINS WEDNESDAY AND THURSDAY
AS LOW AND MID LEVEL MOISTURE STARTS MOVING UP FROM THE SOUTH.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z SATURDAY MORNING)
ISSUED AT 1006 AM MDT FRI MAY 23 2014
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ARE EXPECTED TO OCCUR
THIS AFTERNOON AND EVENING. THE STORMS TODAY WILL NOT BE AS STRONG
AS THE PAST FEW DAYS. STILL...BRIEF HEAVY RAIN AND SMALL HAIL
WITH CEILINGS BELOW 4000 FEET WILL BE POSSIBLE WITH THE
THUNDERSTORMS.
LIGHT WINDS THIS MORNING ARE EXPECTED TO TURN SOUTHEASTERLY AFTER
18Z AND CONTINUE THROUGH THE AFTERNOON AND EVENING. THERE WILL BE A
CHANCE FOR LOW CLOUDS AND PATCHY FOG AGAIN SATURDAY MORNING DUE
TO THE MOIST AIRMASS.
&&
.HYDROLOGY...
ISSUED AT 308 AM MDT FRI MAY 23 2014
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL OCCUR THIS AFTN INTO
THE EARLY EVENING HOURS. AT THIS TIME THE INTENSITY OF THE STORMS
WILL NOT BE STRONG AS THE PAST FEW DAYS HOWEVER A FEW AREAS COULD
STILL RECEIVE UP TO AN INCH OF RAIN IN 45 MINUTES OR LESS IN THE
FOOTHILLS AND ACROSS THE PLAINS.
SATURDAY WILL CONTINUE TO BE A CONCERN AS STORM MOTION WILL REMAIN SLOW.
OVERALL HOWEVER...MOISTURE IN THE ATMOSPHERE WILL DRY OUT
SLIGHTLY. MONDAY SEEMS TO HAVE A SLIGHT INCREASE IN MOISTURE AS
IT WRAPS AROUND THE BACKSIDE OF THE DEPARTING LOW...BUT FOR NOW IT
SEEMS TO STAY WEST OF THE DIVIDE.
NO MORE HEAVY PRECIPITATION CONCERNS AT THIS TIME TUESDAY ONWARD.
ONLY ISOLATED TO SCATTERED SHOWERS/THUNDERSTORMS WITH MORE AVERAGE
MOISTURE VALUES FOR THIS TIME OF YEAR. THE ONLY CAVEAT TO THAT IS
TEMPERATURES WILL BE INCREASING LIKELY TO ABOVE NORMALS. THIS WILL
SPEED UP SNOWMELT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MEIER
SHORT TERM...RPK
LONG TERM...KRIEDERMAN
AVIATION...MEIER
HYDROLOGY...RPK/KRIEDERMAN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
341 PM EDT FRI MAY 23 2014
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL BRING A FEW ROUNDS OF
SHOWERS AND ISOLATED THUNDERSTORMS THROUGH SUNDAY. TURNING MILDER
SUNDAY THEN WARM AND DRY CONDITIONS EXPECTED FOR MEMORIAL DAY. A
WEAK FRONT MAY BRING SCATTERED SHOWERS TUESDAY INTO EARLY
WEDNESDAY ALONG WITH COOLER TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WIDELY SCT SHOWERS ARE DEVELOPING ACROSS SNE WITH HEAVIER SHOWERS
AND ISOLD TSTMS IN E NY AND VT. THE HRRR IS HANDLING THE SHOWERS
QUITE WELL AND SHOWS HEAVIER SHOWERS DEVELOPING ACROSS W ZONES
THIS EVENING AFTER 6 PM AS MID LEVEL TROF APPROACHES. WHILE SFC
INSTABILITY WILL BEGIN TO WANE WITH LOSS OF HEATING...MID LEVEL
COOLING WILL INCREASE THE MID LEVEL LAPSE RATES ALONG WITH DECENT
QG FORCING FROM THE SHORTWAVE WILL ALLOW CONVECTION TO SUSTAIN
ITSELF INTO THE EVENING HOURS. PRIMARY FOCUS THROUGH THE EVENING
HOURS WILL LIKELY BE ACROSS W MA AND CT WHERE LOW LEVEL
CONVERGENCE IS MAXIMIZED ALONG WEAK BOUNDARY. MARGINAL
INSTABILITY AND PWATS LESS THAN 1" WILL BE A LIMITING FACTOR FOR
HEAVY RAINFALL...BUT VERY SLOW MOVEMENT OF CELLS SUPPORT LOCALLY
HEAVY RAIN IN A FEW LOCATIONS.
AS THE TROF AXIS SHIFTS EWD MAY SEE SHOWERS MOVE ALONG THE SOUTH
COAST AFTER MIDNIGHT AS NE INFLOW INCREASES N OF THE SFC LOW. GFS
AND TO A LESSER EXTENT THE ECMWF INDICATE SHOWERS AFFECTING THE S
COAST AFT 06Z. OTHERWISE...SUBSIDENCE SHOULD ALLOW ACTIVITY TO
DIMINISH IN THE INTERIOR WITH MOSTLY DRY CONDITIONS OVERNIGHT.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
SATURDAY...
MID LEVEL TROF AXIS WILL BE MOVING E OF NEW ENG BUT COLD POOL
ALOFT REMAINS WITH 500 MB TEMPS -20 TO -21C. MARGINAL INSTABILITY
DEVELOPS IN THE WEST WHICH WILL LEAD TO SCT SHOWERS/TSTMS. LOW
LEVEL WINDS INDICATE A WEAK BOUNDARY ACROSS W ZONES WHICH MAY
PROVIDE A FOCUS FOR CONVECTION. LOCALLY HEAVY RAINFALL WILL BE
PRIMARY THREAT AS WINDS ALOFT REMAIN WEAK. ACROSS E NEW
ENG...JUST A FEW SHOWERS EXPECTED BUT NOT MUCH MORE THAN THAT
WITH LIMITED INSTABILITY. ANOTHER DAY WITH LOTS OF CLOUDS
ALTHOUGH SOME BREAKS OF SUN POSSIBLE...ESPECIALLY IN EASTERN NEW
ENG. HIGH TEMPS WILL BE MOSTLY IN THE 60S.
SATURDAY NIGHT...
SOME LINGERING CONVECTION POSSIBLE IN THE WEST IN THE
EVENING...OTHERWISE WEAK RIDGING MOVES INTO THE REGION WHICH
WILL BRING MAINLY DRY CONDITIONS.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...
- SEA-BREEZE SUNDAY WILL BE THE FOCUS OF SHOWERS/THUNDERSTORMS
- MEMORIAL DAY MIX WITH BEST CONDITIONS SW WITH DISMAL WEATHER NE
- COLD FRONT AND WET WEATHER EXPECTED FOR TUESDAY
- SEASONABLE CONDITIONS AND BOUTS OF WET WEATHER INTO THE WEEKEND
/ OVERVIEW AND MODEL PREFERENCE...
IS THIS LATE MAY OR EARLY MARCH? PERSISTENT LOWER HEIGHTS ACROSS
GREENLAND STRENGTHEN THE NORTH-ATLANTIC RIDGE. AS SUCH THE LONGWAVE
PATTERN BUCKLES. SUBSEQUENTLY TROUGHING IS PREFERRED ALONG THE W-
PERIPHERY OF WHICH DISTURBANCES DIG SOUTHWARD RESULTING IN THE
CONTINUANCE OF COOLER WET WEATHER ACROSS A MAJORITY OF THE NE-CONUS
AGAINST RIDGING THROUGH THE MIDWEST AHEAD OF THE MIGRATING LOW INTO
THE CENTRAL CONUS. THIS PATTERN MAY LINGER FOR AWHILE INTO THE START
OF SUMMER.
WITH THE NAO EXHIBITING A NEAR-NEUTRAL TREND WITH ENSEMBLE MEMBERS
AND GREATER CONFIDENCE GAINED FROM BOTH GEFS/ECENS/NAEFS H5 MEANS OF
STRONGER REAR-TROUGHING INFLUENCE WITH A NW-SE STREAM OF THE W-
PERIPHERY ACROSS NEW ENGLAND...WILL PREVAIL WITH NEAR-SEASONABLE
CONDITIONS AND CHANCES OF WET-WEATHER KEEPING THE WARMER-RIDGING
PATTERN TO THE W. MODEL CONSENSUS IS PREFERRED THROUGH THE WEEKEND
BUT THEREAFTER ENSEMBLE MEAN TRENDS ARE RECOMMENDED.
/ DAY-TO-DAY DETAILS...
SUNDAY...
COMBINATION OF A SEA-BREEZE FRONT PROVIDING FORCING BENEATH CYCLONIC
FLOW...WEAK MID-LEVEL IMPULSES...AND THE LFQ OF THE UPPER-LEVEL JET
STREAK...LOOKS TO GENERATE LIFT TOWARDS SHOWERS AND THUNDERSTORMS BY
MIDDAY INTO EVENING ACROSS INTERIOR NEW ENGLAND /ESPECIALLY E/.
CHALLENGES IN FORECASTING EXACT OUTCOMES IS DIFFICULT AT MODELS
DIFFER ON INSTABILITY AND PRECIPITATION OUTPUT. NOTING CONSISTENCY
OF NW-SE UNIDIRECTIONAL SHEAR...FREEZING LVL HEIGHTS AROUND 8 KFT...
PWATS AROUND 0.75-INCHES...AND MINOR INSTABILITY...WET-WEATHER
ACTIVITY IS EXPECTED. A HEAVY RAIN / SMALL HAIL THREAT ALONG WITH
GUSTY WINDS IS POSSIBLE WITH ANY STORMS. MAIN CONCERN IS WITH ANY
TRAINING N TO S WITH THE MEAN-LAYER FLOW ALONG THE SEA-BREEZE FRONT.
EXPECTING ACTIVITY TO CONCLUDE OVERNIGHT WITH THE END OF DAYTIME
HEATING. WITH A STRONGER MID-LEVEL DISTURBANCE DIGGING TOWARDS NE
NEW ENGLAND INVOKING SW-FLOW...ANTICIPATE A DEFINING WARM-FRONTAL
BOUNDARY LIFTING NE OF THE REGION...PERHAPS DRAPED S ALONG THE
IMMEDIATE COAST W.
MONDAY /MEMORIAL DAY/...
WARM-FRONT SITUATES ACROSS NE NEW ENGLAND ALONG WHICH A STRONG MID-
LEVEL IMPULSE PROVIDES ENHANCED ASCENT TOWARDS THE DEVELOPMENT OF
WET-WEATHER. ITS EXTENT SW IS SPECULATIVE.
WITH THE BEST DYNAMICS NE AND MUCH OF OUR REGION BENEATH THE RFQ OF
THE UPPER-LEVEL JET...WILL KEEP THE DAYTIME FORECAST TIMEFRAME
MOSTLY DRY WITH THE EXPECTATION OF SOME LEVEL OF SUBSIDENCE. NW-FLOW
COULD IMPINGE UPON HIGHER TERRAIN UNDERGOING OROGRAPHIC LIFT BENEATH
CYCLONIC FLOW AND FALLING HEIGHTS RESULTING IN SHOWER DEVELOPMENT.
OVERALL...WETTER/COOLER/CLOUDIER TO THE NE WHEREAS THE BEST WARM-
SUNNY CONDITIONS ARE TO THE SW. EXPECT A NE-SW TEMPERATURE GRADIENT
WITH VALUES EXCEEDING 80-DEGREES OVER THE LOWER CT-VALLEY.
COLD FRONT ATTENDANT TO THE LOW PRES CENTER INVIGORATED BY THE MID-
LEVEL IMPULSE BEGINS TO SWEEP SE INTO THE FORECAST REGION. EXPECT AN
INCREASE IN WET-WEATHER CONDITIONS TOWARDS MORNING AS TEMPERATURES
PERHAPS COOL TOWARDS MIDNIGHT BUT THEN UNDERGO A NON-DIURNAL TREND
THEREAFTER WITH INCREASING SW-FLOW.
MIDWEEK TOWARDS THE WEEKEND...
MODEL SPREAD INCREASES LENDING TO UNCERTAINTY TOWARDS EXACT OUTCOMES
AND THUS ONE CAN ONLY SPECULATE. NO ONE MODEL IS PREFERRED.
ITS LIKELY A COLD FRONT AND ATTENDANT WET-WEATHER WILL SWEEP ACROSS
THE REGION TUESDAY. TIMING AND SPECIFIC IMPACTS ARE HIGHLY UNCERTAIN
AND THERE IS SOME QUESTION AS TO THE DIRECTION OF FLOW REARWARD OF
THE COLD FRONT...WHETHER NW OR NE. A PERIOD OF DRY WEATHER IS
POSSIBLE THROUGHOUT THE REMAINDER OF THE WEEK...BUT BENEATH CYCLONIC
FLOW THROUGH WHICH WEAK IMPULSES ARE LIKELY TO DIG SOUTH...EXPECT
INTERMITTENT BOUTS OF WET-WEATHER.
OF GREATER CERTAINTY IS THE FACT THAT THE CONTINUED INFLUENCE OF A
TROUGHING PATTERN THE W-PERIPHERY OF WHICH REMAINS SITUATED ACROSS
NEW ENGLAND WILL RESULT IN NEAR-SEASONABLE CONDITIONS. EXPECTING
SOME NORTHERLY COMPONENT OF FLOW TO KEEP COOLER WEATHER ACROSS THE
REGION. DO NOT BELIEVE THE PATTERN WILL SHIFT INTO NEXT WEEKEND.
HAVE A BAD FEELING THE TROUGH LINGERS FOR AWHILE LONGER RESULTING
IN PROLONGED COOL WEATHER.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...LOW CONFIDENCE TONIGHT.
MODERATE CONFIDENCE SAT AND SAT NIGHT.
THROUGH 00Z...MAINLY MVFR CIGS WITH AREAS OF VFR RI/SE MA AND
CAPE/ISLANDS WILL TREND TOWARD MVFR WITH AREAS OF IFR TOWARD
EVENING. SCT TO NUMEROUS SHOWERS AND A FEW TSTMS DEVELOPING IN W
NEW ENG 21-00Z.
TONIGHT...EXPECT CONDITIONS TO LOWER WITH WIDESPREAD MVFR/IFR
DEVELOPING BUT TIMING IS UNCERTAIN. ALSO LOW CONFIDENCE ON EXTENT
OF FOG. CURRENT THINKING IS FOG WILL BE PATCHY AND NOT DENSE.
NUMEROUS SHOWERS AND EMBEDDED TSTMS IN THE EVENING...MAINLY W.
NE WIND GUSTS TO 25 KT DEVELOPING OUTER CAPE/ISLANDS TOWARD 12Z.
SATURDAY...MVFR/IFR EXPECTED TO IMPROVE TO VFR IN THE AFTERNOON AS
WINDS BECOME MORE NORTHERLY. NE WIND GUSTS TO 25 KT IN THE MORNING
OVER THE CAPE/ISLANDS. SCT SHOWERS/TSTMS DEVELOPING IN THE
AFTERNOON IN THE WEST WITH BRIEF MVFR POSSIBLE.
SATURDAY NIGHT...MAINLY VFR...BUT PATCHY FOG POSSIBLE ALONG THE
COAST.
KBOS TAF...MODERATE CONFIDENCE. VFR WILL DETERIORATE TO MVFR LATE
AFTERNOON AND PERSIST INTO SAT MORNING. AREAS OF IFR DEVELOPING
TONIGHT BUT TIMING UNCERTAIN.
KBDL TAF...MODERATE CONFIDENCE. MAINLY MVFR INTO SAT MORNING BUT
LOW CONFIDENCE ON ANY IFR DEVELOPING. SCT SHOWERS AND A POSSIBLE
THUNDERSTORM LATE AFTERNOON/EVENING AND AGAIN SAT AFTERNOON.
OUTLOOK...SUNDAY THROUGH TUESDAY...
SUNDAY...MODERATE CONFIDENCE.
SEA-BREEZE PUSHING E WILL BE THE FOCUS FOR SHRA/TSRA ACROSS THE E/C
INTERIOR AS W/SW WINDS CONVERGE WITH WINDS FROM THE E. TEMPO MVFR-
IFR WITH ACTIVITY. THINKING ISOLATED TSRA. ACTIVITY CONCLUDES INTO
THE OVERNIGHT HOURS.
MONDAY...MODERATE CONFIDENCE.
WILL HOLD SW TERMINALS IN VFR WHEREAS TO THE NE EXPECT A MIX OF MVFR
TO LOW-VFR WITH THE POSSIBILITY OF -SHRA. SW FLOW PREVAILS. WILL SEE
INCREASING CHANCES FOR RAIN AHEAD OF A COLD FRONT TOWARDS TUESDAY
MORNING.
TUESDAY INTO WEDNESDAY...LOW CONFIDENCE.
COLD FRONT SWEEPING THROUGH THE TERMINALS THE TIMING AND IMPACTS OF
WHICH REMAIN UNCERTAIN. MIX OF MVFR-IFR CONDITIONS POSSIBLE ALONG
THE FRONT WITH WET-WEATHER. N-WINDS BEHIND THE FRONT THE DIRECTION
OF WHICH IS ALSO UNCERTAIN.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...HIGH CONFIDENCE.
LOW PRES PASSES S OF THE WATERS LATE TONIGHT AND SAT AND
INCREASING LOW LEVEL NE WINDS WILL LIKELY BRING A PERIOD OF G25
KT TO THE SOUTHERN WATERS LATE TONIGHT AND SAT MORNING ALONG WITH
BUILDING SEAS TO 5 FT SO WE ISSUED AN SCA. IT IS POSSIBLE SCA MAY
NEED TO BE EXPANDED TO NEARSHORE S COASTAL WATERS BUT NOT
CONFIDENT ENOUGH STRONGER WINDS WILL REACH THAT FAR N. WINDS
DIMINISH SAT AFTERNOON WITH LIGHT WINDS/SEAS SAT NIGHT AS WEAK
RIDGING DEVELOPS.
AREAS OF FOG ARE POSSIBLE TONIGHT WHICH COULD BE LOCALLY DENSE AT
TIMES.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY...MODERATE CONFIDENCE.
SEA-BREEZES ALONG THE IMMEDIATE SHORES WITH SOUTHERLY FLOW OVERALL.
INCLEMENT WEATHER MAINLY ACROSS THE INTERIOR. SEAS REMAINING BELOW 5
FEET.
MONDAY...MODERATE CONFIDENCE.
W/SW WINDS WITH GUSTS UP TO 25 KTS /ESP ALONG THE SHORE/. SEAS ON
THE OUTER-WATERS UP TO 5 FEET. SHOWERS POSSIBLE ACROSS THE E-WATERS
AROUND CAPE ANN.
TUESDAY INTO WEDNESDAY...LOW CONFIDENCE.
COLD FRONT SWEEPING ACROSS THE WATERS THE TIMING OF WHICH IS
UNCERTAIN. BREEZY SW WINDS ALONG AND AHEAD BACKING OUT OF THE N TO
THE REAR. WAVES ON THE OUTER WATERS ABOVE 5-FEET.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM TO 4 PM EDT SATURDAY FOR
ANZ254>256.
&&
$$
SYNOPSIS...KJC/SIPPRELL
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...SIPPRELL
AVIATION...KJC/SIPPRELL
MARINE...KJC/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAUNTON MA
203 PM EDT FRI MAY 23 2014
.SYNOPSIS...
LOW PRESSURE WILL BRING A FEW ROUNDS OF SHOWERS AND ISOLATED
THUNDERSTORMS THROUGH SUNDAY...BUT CERTAINLY NOT EXPECTING A
WASHOUT. TURNING MILDER SUNDAY THEN WARM AND DRY CONDITIONS
EXPECTED FOR MEMORIAL DAY. A WEAK FRONT MAY BRING SCATTERED
SHOWERS TUESDAY INTO EARLY WEDNESDAY ALONG WITH COOLER
TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
***SHOWERS AND EMBEDDED THUNDERSTORMS ACROSS WESTERN MA/NORTHERN CT
WITH LOCALLY HEAVY RAINFALL EXPECTED THIS AFTERNOON AND EVENING***
2 PM UPDATE...
WIDELY SCT SHOWERS ARE DEVELOPING ACROSS CENTRAL AND W NEW ENG
WITH HEAVIER SHOWERS AND SCT TSTMS IN E NY. THE HRRR IS HANDLING
THE SHOWERS QUITE WELL AND SHOWS HEAVIER SHOWERS DEVELOPING ACROSS
W ZONES LATE AFTERNOON THROUGH THE EVENING AS MID LEVEL SHORTWAVE
APPROACHES. SBCAPES CURRENTLY ONLY 100-200 J/KG WITH FORECAST
INDICATING UP TO 500 J/KG. MARGINAL INSTABILITY AND PWATS LESS
THAN 1" WILL BE A LIMITING FACTOR FOR HEAVY RAINFALL...BUT VERY
SLOW MOVEMENT OF CELLS SUPPORT LOCALLY HEAVY RAIN IN A FEW
LOCATIONS.
PREVIOUS DISCUSSION
1015 AM UPDATE...
ALL IS QUIET WITH A JUST A FEW SHOWERS MOVING NE FROM S NH. THE
MAIN CONCERN FOR LATER THIS AFTERNOON INTO THE EVENING IS
POTENTIAL FOR CONVECTION AS STRONG MID LEVEL SHORTWAVE DIVES SE
FROM THE GT LAKES. MODELS INDICATE SOME WEAK INSTABILITY WITH
SBCAPES AROUND 500 J/KG IN THE WEST ALONG WITH DECENT MID LEVEL
COOLING AND QG FORCING SO EXPECT SCT TO NUMEROUS SHOWERS AND
EMBEDDED TSTMS TO DEVELOP. MAIN FOCUS FOR CONVECTION WILL BE IN
WESTERN NEW ENG WHERE BEST INSTABILITY COMBINED WITH LOW LEVEL
CONVERGENCE ALONG A WEAK INVERTED TROF. HRRR IS TARGETING THE
WEST MOSTLY AFTER 20Z. WIND FIELDS ARE QUITE WEAK LATER THIS
AFTERNOON SO SEVERE THREAT IS LOW...BUT HEAVY RAINFALL WILL BE A
CONCERN AS STORMS WILL LIKELY BE SLOW MOVING.
MEANWHILE...ACROSS EASTERN NEW ENGLAND SCATTERED SHOWERS MAY
AFFECT THE REGION AT TIMES. HOWEVER...GIVEN MARINE LAYER/LESS
INSTABILITY NOT EXPECTING THUNDER OR THE ACTIVITY TO BE AS
WIDESPREAD.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT...
SHOWERS AND EMBEDDED THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL WILL
CONTINUE ACROSS WESTERN NEW ENGLAND DURING THE EVENING HOURS IN
ASSOCIATION WITH THE SHORTWAVE. ACROSS EASTERN SECTIONS...JUST
EXPECTED SOME SCATTERED SHOWERS AS INSTABILITY/FORCING WILL BE LESS.
ACTIVITY SHOULD DIMINISH IN ALL AREAS AFTER MIDNIGHT...BUT SOME
MORE LOW CLOUDS AND PATCHY FOG WILL PROBABLY DEVELOP.
SATURDAY...
ANOTHER SHORTWAVE WILL LIKELY TRIGGER SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SAT AFTERNOON...MAINLY ACROSS WESTERN NEW ENGLAND
WHERE BETTER INSTABILITY IS LOCATED. SHORTWAVE DOES NOT LOOK AS
POTENT AS TODAY/S...SO NOT EXPECTING ACTIVITY TO BE AS WIDESPREAD.
ACROSS EASTERN NEW ENGLAND...PERHAPS A FEW SHOWERS BUT NOT MUCH MORE
THAN THAT WITH LIMITED INSTABILITY. HIGH TEMPS WILL MAINLY BE IN
THE 60S...WITH THE WARMEST READINGS IN THE LOWER CONNECTICUT RIVER
VALLEY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGHLIGHTS...
- WEEKEND CHANCES OF SHOWERS/THUNDERSTORMS ACROSS THE INTERIOR
- NICE AND MILD FOR MEMORIAL DAY
- ANOTHER SHOT OF WET WEATHER FOR TUESDAY AND WEDNESDAY
OVERVIEW AND MODEL PREFERENCES...
00Z MODEL GUIDANCE SUITE CONTINUES TO SHOW A GRADUAL TREND AWAY
FROM EASTERN RIDGE BUILDING THAT...THE TREND FROM EARLIER IN THE
WEEK. THIS IS CONSISTENT WITH SEVERAL OF THE ENSEMBLES SUGGESTING
A POSITIVE NAO...ALTHOUGH STILL WITH CONSIDERABLE SPREAD. GIVEN
THE RECENT SHIFT IN LONG TERM PATTERN AND UNCERTAINTY WITH SEVERAL
SMALLER SCALE WAVES/RIDGING IN A COOLER/TROUGH DRIVEN PATTERN...A
BLEND OF ENSEMBLES WITH THE PREVIOUS FORECAST SEEMS APPROPRIATE
FOR THE LONG TERM.
UNSTABLE...AS NOTED BY THE PREVIOUS FORECASTER...APPEARS TO BE
THE BEST WAY TO DEFINE THE LONG TERM. NOT NECESSARILY IN THE
ATMOSPHERIC STABILITY SENSE /ALTHOUGH THAT WILL BE A PLAYER AS
WELL AT TIMES/...BUT IN THE SENSE THAT THERE IS A LOT OF DAY-TO-
DAY UNCERTAINTY GIVEN WE ARE DEALING WITH A WEAK LONGWAVE TROF AND
SEVERAL ENERGY WAVES MOVING THROUGH IT. WITH LONGWAVE TROF IN
PLACE...THE WARM FRONT AHEAD OF BUILDING CENTRAL CONUS RIDGE MAY
ACTUALLY STALL...SOUTHWEST OR AT LEAST IN THE VICINITY OF SRN NEW
ENGLAND. THIS WAS THE WARM FRONT/RIDGE THAT WAS ORIGINALLY
SUGGESTING AN ABOVE NORMAL TEMPERATURE PERIOD. HOWEVER...NOW GIVEN
THAT THIS LOOKS TO REMAIN W OF NEW ENGLAND...A NEAR TO POTENTIALLY
EVEN BELOW NORMAL PATTERN LOOKS MORE FAVORABLE...WITH THE
POSSIBILITY OF PERIODIC WET WX WITH SHORTWAVE ENERGY OR SOME
MODEST DIURNAL INSTABILITY. THESE OVERALL TRENDS LOOK TO HOLD AT
LEAST THROUGH MID WEEK...BUT THE UNCERTAINTY SNOWBALLS TOWARD THE
END OF THE PERIOD.
DETAILS...
SAT NIGHT INTO SUN...
WITH POTENTIAL FOR DIURNAL/SHORTWAVE DRIVEN CONVECTION DURING THE
AFTERNOON AND EVENING...SOME SHOWERS/TSTORMS MAY LINGER INTO THE
EARLY OVERNIGHT HOURS UNTIL INSTABILITY IS LOSS WITH SETTING SUN.
THE CORE OF THE UPPER LVL SHORTWAVE MOVES THROUGH DURING THE EARLY
MORNING HOURS...SO WILL ACTUALLY HOLD ON TO POPS A BIT LONGER INTO
THE OVERNIGHT HOURS. BY SUN...STILL NOTE MODESTLY STEEP LAPSE
RATES AROUND 6.0-7.0C/KM BUT LESS OF A MECHANISM FOR LIFT.
THEREFORE...STILL LOOKS LIKE AFTERNOON SHOWERS/T-STORMS ARE
POSSIBLE...BUT SPATIAL EXTENT IS LIKELY TO BE LESS THAN THAT OF
SATURDAY. TEMPS NEAR NORMAL ARE LIKELY GIVEN +10C AT H85 AND
MIXING SHOULD AT LEAST MAKE A RUN AT NORMAL VALUES.
SUN NIGHT INTO MON...
AGREE WITH PREVIOUS FORECASTER THAT THIS PERIOD LOOKS TO BE THE
MOST LIKELY PERIOD FOR DRY WX THROUGH MID WEEK. MID LVL RIDGE WILL
EJECT OUT OF THE CENTRAL CONUS AS ANOTHER SHORTWAVE TROF DIVES
INTO THE NORTHEAST FROM NRN QC...FLATTENING IT AS IT APPROACHES.
THEREFORE...WITH SOME SUBSIDENCE STILL EVIDENT IN THE COLUMN
THROUGH THE PERIOD /AFTER ANY SUN EVENING SHOWERS/STORMS DIMINISH/
LOOK FOR MAINLY DRY FORECAST PERIOD INTO LATE MON.
THEREFORE...WILL CONTINUE THIS PATTERN WITH THIS OVERNIGHT
FORECAST UPDATE. H85 TEMPS AROUND +12 SUGGEST THE POSSIBILITY OF
TEMPS IN THE UPPER 70S TO AROUND 80...EVEN NEAR SHORE AS STRONG W
COMPONENT TO THE WIND IS LIKELY TO MITIGATE SEA BREEZE THREAT.
TUE AND WED...
AS MENTIONED BEFORE...THERE IS A LOT OF VARIABILITY BETWEEN
SOLUTIONS NOT JUST IN DETERMINISTIC GUIDANCE...BUT ENSEMBLES AS
WELL...BEGINNING THIS PERIOD. ALTHOUGH THERE IS NOW THE SUGGESTION
OF REINFORCEMENT OF THE TROF ACROSS THE NORTHEAST...KEEPING THE
STRONG RIDGING W OF THE GREAT LAKES...EXACTLY HOW THIS PLAYS OUT
IN SENSIBLE WX REMAINS MORE UNCERTAIN. GFS AND SOME MODELS
GENERATE STRONG LOW PRES WHICH MAY SLIDE S OF THE
REGION...DELIVERING A PROLONGED PERIOD OF WET WX...WHILE THE ECMWF
AND OTHER ENSEMBLES LEAN MORE ON A SERIES OF SHORTWAVES
CULMINATING IN COLD FRONTAL PASSAGE. IN ANY CASE...WITH PWAT
VALUES AVERAGING AROUND 1.0 INCHES...COOLING UPPER LVL TEMPS AND
AT LEAST A COUPLE OF SOURCES FOR LIFT...ANOTHER ROUND OF
POTENTIALLY WET/UNSETTLED WX IS EXPECTED. WILL NEED TO MONITOR THE
SHORTWAVE PLAYERS AS THEY MIGRATE THROUGH CANADA THROUGH THE
WEEKEND TO BETTER REFINE THE EXACT TIMING/LOCATIONS OF POTENTIAL
PRECIP.
LATE NEXT WEEK...
WITH CONUS RIDGING ATTEMPTING A SLIDE TO THE EAST THROUGH THIS
PERIOD EXACT DETAILS WILL DEPEND STRONGLY ON HOW QUICKLY THE
PERSISTENT TROF ACROSS THE NE HOLDS IN. IN ANY CASE...A PERIOD OF
DRY WX MAY FOLLOW THE UNSETTLED MID-WEEK TIMEFRAME THANKS TO
ANOTHER SHORTWAVE RIDGE EJECTION. WILL TREND TOWARD LOWER TO NIL
POPS...BUT EXACT TEMPERATURES WILL BE DEPENDENT ON TO WHAT EXTENT
THE TROF REMAINS OR THE WARM FRONT ASSOCIATED WITH THE RIDGE TO
THE W MOVES THROUGH. SO TEMPERATURES ARE LOW CONFIDENCE AT THIS
TIME.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...LOW CONFIDENCE TONIGHT.
MODERATE CONFIDENCE SAT AND SAT NIGHT.
THROUGH 00Z...MAINLY MVFR CIGS WITH AREAS OF VFR RI/SE MA AND
CAPE/ISLANDS WILL TREND TOWARD MVFR WITH AREAS OF IFR TOWARD
EVENING. SCT TO NUMEROUS SHOWERS AND A FEW TSTMS DEVELOPING IN W
NEW ENG 21-00Z.
TONIGHT...EXPECT CONDITIONS TO LOWER WITH WIDESPREAD MVFR/IFR
DEVELOPING BUT TIMING IS UNCERTAIN. ALSO LOW CONFIDENCE ON EXTENT
OF FOG. CURRENT THINKING IS FOG WILL BE PATCHY AND NOT DENSE.
NUMEROUS SHOWERS AND EMBEDDED TSTMS IN THE EVENING...MAINLY W.
NE WIND GUSTS TO 25 KT DEVELOPING OUTER CAPE/ISLANDS TOWARD 12Z.
SATURDAY...MVFR/IFR EXPECTED TO IMPROVE TO VFR IN THE AFTERNOON AS
WINDS BECOME MORE NORTHERLY. NE WIND GUSTS TO 25 KT IN THE MORNING
OVER THE CAPE/ISLANDS. SCT SHOWERS/TSTMS DEVELOPING IN THE
AFTERNOON IN THE WEST WITH BRIEF MVFR POSSIBLE.
SATURDAY NIGHT...MAINLY VFR...BUT PATCHY FOG POSSIBLE ALONG THE
COAST.
KBOS TAF...MODERATE CONFIDENCE. VFR WILL DETERIORATE TO MVFR LATE
AFTERNOON AND PERSIST INTO SAT MORNING. AREAS OF IFR DEVELOPING
TONIGHT BUT TIMING UNCERTAIN.
KBDL TAF...MODERATE CONFIDENCE. MAINLY MVFR INTO SAT MORNING BUT
LOW CONFIDENCE ON ANY IFR DEVELOPING. SCT SHOWERS AND A POSSIBLE
THUNDERSTORM LATE AFTERNOON/EVENING AND AGAIN SAT AFTERNOON.
OUTLOOK...SUNDAY THROUGH TUESDAY...
SUN...MODERATE CONFIDENCE. VFR DOMINATING DURING THE DAY ON SUN
OUTSIDE OF AFTERNOON SHOWERS AND THUNDERSTORMS. WINDS SHIFT FROM
THE N-NE TO THE S EARLY IN THE DAY ON SUN.
MON AND MON NIGHT...HIGH CONFIDENCE.
WINDS SHIFT TO THE W...WITH GUSTS AROUND 25 KT POSSIBLE DURING THE
AFTERNOON. LOWER CHANCES IN AFTERNOON SHOWERS AND
THUNDERSTORMS...BUT NON-ZERO. MAINLY VFR OUTSIDE OF ANY LOCALIZED
MVFR/IFR IN SHOWERS/STORMS.
TUE...LOW CONFIDENCE.
EXPECT MORE WIDESPREAD SHOWERS...AND MAYBE A THUNDERSTORM DURING
THE DAY ON TUESDAY. MIX OF MVFR/IFR POSSIBLE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY AFTERNOON/...HIGH CONFIDENCE.
WINDS/SEAS WILL REMAIN BELOW SCA LEVELS TODAY. LOW PRESSURE WILL
PASS SOUTH OF THE WATERS LATER TONIGHT AND SATURDAY. SEAS MAY BUILD
TO BETWEEN 3 AND 5 FEET WITH NORTHEAST WIND GUSTS OF 20 TO 25 KNOTS
LATE TONIGHT INTO SATURDAY ACROSS THE SOUTHERN WATERS. SINCE ITS A
MARGINAL LATE 2ND AND 3RD PERIOD EVENT...WILL DEFER POSSIBLE SCA
HEADLINES TO THE NEXT SHIFT.
THE OTHER MAIN CONCERN ON THE WATERS IS FOR AREAS OF FOG WHICH COULD
BE LOCALLY DENSE AT TIMES...PARTICULARLY DURING THE LATE NIGHT/EARLY
MORNING HOURS.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT INTO SUNDAY...MODERATE CONFIDENCE.
WINDS SHIFT FROM PREDOMINANTLY N-NE TO THE S-SW DURING THE DAY ON
SUN...BUT REMAIN BELOW 25 KT. SEAS TOO REMAIN BELOW 5 FT THROUGH
THE PERIOD. SOME LOW VSBYS POSSIBLE ESPECIALLY SUN MORNING IN FOG.
MONDAY...MODERATE CONFIDENCE.
WINDS SHIFT TO THE W AND STRENGTHEN ON MON...WITH SOME GUSTS
AROUND 25 KT...ESPECIALLY NEAR THE SHORE DURING THE AFTERNOON.
WITH STRONGER WINDS...EXPECT SEAS TO BUILD ESPECIALLY ON THE OCEAN
WATERS...POSSIBLY REACHING 5 FT BY LATE IN THE DAY.
TUESDAY...LOW CONFIDENCE.
SOME RAIN POSSIBLE WITH A FRONTAL PASSAGE WITH WINDS SHIFTING FROM
THE W...TO THE N. ALTHOUGH THE CONFIDENCE IN WINDS AROUND 25 KT IS
LOW...SOME LINGERING SWELLS OF 5+ FT MAY MEAN SMALL CRAFT
ADVISORIES REMAIN ACROSS SOME OF THE WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...KJC
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...KJC/DOODY
MARINE...FRANK/DOODY
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
357 PM EDT FRI MAY 23 2014
.SYNOPSIS...
A COLD FRONT WILL DROP THROUGH THE AREA OVERNIGHT WITH HIGH PRESSURE
BUILDING BEHIND IT SATURDAY. THE HIGH WILL SHIFT INTO THE WESTERN
ATLANTIC ON SUNDAY AND REMAIN THE DOMINANT FEATURE THROUGH THE FIRST
PART OF NEXT WEEK BEFORE A COLD FRONT MOVES IN MID WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AFTERNOON VISIBLE SATELLITE IMAGERY INDICATES THE UPPER RIDGE HAS
BEGUN TO ERODE ACROSS CENTRAL AND EASTERN SC GIVEN THE INCREASING
CUMULUS FIELD. THE CU FIELD ACROSS OUR FORECAST AREA INDICATES THE
SEA BREEZE IS INCHING INLAND...NOW NEAR DANIEL ISLAND AND
APPROACHING NORTH CHARLESTON. GIVEN TEMPERATURES IN THE MID TO
UPPER 90S AND MIDDLE 60S DEWPOINTS...WE CANNOT RULE OUT AN
ISOLATED SHOWER OR TSTM ALONG THE SEA BREEZE THOUGH THE LOW-LEVEL
CONVERGENCE REMAINS QUITE WEAK IN THE VICINITY.
OUR MAIN FOCUS IS ON CONVECTION DEVELOPING WELL UPSTREAM AHEAD OF
A SUBTLE SHORTWAVE TROUGH. SEVERAL SEVERE TSTMS HAVE RECENTLY
POPPED UP ACROSS THE SC UPSTATE...WITH LARGE HAIL THE PRIMARY
ISSUE. THE CU FIELD ACROSS THE SC MIDLANDS HAS INCREASED DURING
THE LAST TWO HOURS...WITH SOME TOWERING CU EMBEDDED. RUC SOUNDING
AT KCHS SHOWS THE PRONOUNCED CAP AROUND 700 MB DISAPPEARING
BETWEEN 4 AND 6 PM. MEANWHILE...THE SEA BREEZE WILL BRING
INCREASING DEWPOINTS TO COASTAL SC. UPPER FORCING ASSOCIATED WITH
THE SHORTWAVE WILL BE OUR PRIMARY TRIGGER FOR CONVECTION...LIKELY
AFTER 5 PM AND FOCUSED AROUND 7 OR 8 PM. WE MADE LITTLE CHANCE TO
ONGOING POP FORECAST...SHOWING CHANCE POPS ACROSS FAR NORTHERN
AREAS EARLY THIS EVENING...SHIFTING OFFSHORE BEFORE MIDNIGHT.
SEVERE WX PARAMETERS MAINTAIN STRONG INSTABILITY AND COLD MID
LEVELS...SUPPORTING PRIMARILY A LARGE HAIL THREAT WITH A SECONDARY
WIND THREAT. LATER TONIGHT THE BACK DOOR COLD FRONT WILL DROP
THROUGH THE AREA WITH DRIER AIR AND NORTHERLY WINDS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY AND SATURDAY NIGHT...A BACKDOOR COLD FRONT WILL CONTINUE TO
DROP WELL SOUTH OF THE AREA AS SURFACE HIGH PRESSURE BUILDS IN FROM
THE OHIO VALLEY. A RELATIVELY DRY NORTHERLY FLOW WILL PREVAIL
THROUGH MUCH OF THE DAY AT THE SURFACE AND OVERALL MOISTURE WILL BE
INSUFFICIENT TO SUPPORT ANY PRECIPITATION ACROSS THE AREA. A SHORT
WAVE DISTURBANCE EMBEDDED WITHIN NORTHWEST FLOW ALOFT SHOULD BRING
SOME MID AND HIGH LEVEL CLOUDS INTO THE AREA LATER IN THE DAY AND
DURING SATURDAY NIGHT. TEMPERATURES WILL BE COOLER THAN PREVIOUS
DAYS...BUT DOWNSLOPE FLOW JUST ALOFT COULD STILL SUPPORT HIGHS IN
THE MID TO UPPER 80S ACROSS SOUTHEAST SC AND UPPER 80S TO AROUND 90
ACROSS SOUTHEAST GEORGIA. A ROBUST SEABREEZE SHOULD KEEP
TEMPERATURES ALONG THE IMMEDIATE COAST CONSIDERABLY COOLER. WITH THE
INCREASE IN CLOUD COVER AND A LIGHT ONSHORE SYNOPTIC FLOW DEVELOPING
SATURDAY NIGHT...LOWS SHOULD BE IN THE LOWER TO MID 60S.
SUNDAY AND SUNDAY NIGHT...SURFACE HIGH PRESSURE WILL SHIFT INTO THE
WESTERN ATLANTIC...SUPPORTING A SYNOPTIC ONSHORE FLOW ACROSS THE
AREA RESULTING IN AN INCREASE IN LOW LEVEL MOISTURE. FORCING
PROVIDED BY SHORT WAVE ENERGY EMBEDDED WITHIN THE NORTHWEST FLOW
ALOFT AND CONVERGENCE ALONG/AHEAD OF THE SEABREEZE SHOULD SUPPORT
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY ALONG AND
WEST OF THE I-95 CORRIDOR IN THE AFTERNOON AND EARLY EVENING.
MODERATE INSTABILITY WITH CAPE VALUES AS HIGH AS 1500-2500 J/KG AND
LI/S DOWN TO -7 TO -8C...HIGHEST ACROSS INTERIOR SOUTHEAST GA...
SHOULD BE SUFFICIENT FOR PULSE-TYPE ISOLATED SEVERE THUNDERSTORMS TO
OCCUR. ISOLATED CONVECTION COULD RE-FOCUS OVER THE COASTAL WATERS
LATE SUNDAY NIGHT. HIGHS ON SUNDAY SHOULD BE IN THE MID TO UPPER 80S
AWAY FROM THE COAST WITH LOWS SUNDAY NIGHT IN THE MID TO UPPER 60S.
MONDAY...A MOIST SOUTHERLY RETURN FLOW WILL DEVELOP AROUND ATLANTIC
HIGH PRESSURE. MEANWHILE...A LEE SIDE TROUGH INLAND AND THE SEA
BREEZE WILL ACT AS FOCI FOR MAINLY AFTERNOON/EVENING SCATTERED
SHOWERS AND THUNDERSTORMS. MODERATE INSTABILITY PARAMETERS ONCE
AGAIN LOOK FAVORABLE FOR ISOLATED PULSE SEVERE THUNDERSTORMS ALONG
AND AHEAD OF THE SEA BREEZE. HIGHS WILL BE IN THE UPPER 80S ACROSS
MUCH OF THE AREA AWAY FROM THE IMMEDIATE COAST.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
GENERALLY NORTHWEST FLOW ALOFT WILL PREVAIL THROUGH THE PERIOD. A
COLD FRONT SHOULD MOVE INTO THE AREA IN THE MID WEEK TIME FRAME AND
LIKELY STALL OUT. EXPECTED WIDELY SCATTERED TO SCATTERED MAINLY
AFTERNOON AND EVENING THUNDERSTORMS ALONG AND WEST OF THE SEA BREEZE
EACH DAY...WITH THE GREATEST COVERAGE LIKELY ON WEDNESDAY AS THE
COLD FRONT MOVES IN. ABOVE NORMAL TEMPERATURES ARE EXPECTED TUESDAY
AND WEDNESDAY AND THEN MORE NORMAL TEMPERATURES ARE LIKELY THURSDAY
AND FRIDAY.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
PRIMARILY VFR AT BOTH TERMINALS THROUGH 18Z SATURDAY. MAINTAINED
VCTS AT KCHS EARLY THIS EVENING B/C WE EXPECT CONVECTION TO BE
DROPPING IN FROM THE NORTHWEST AHEAD OF A COLD FRONT. COVERAGE
STILL DOES NOT LOOK ESPECIALLY GREAT SO WE DID NOT INCLUDE A TEMPO
GROUP AS OF YET. WINDS WILL SHIFT NNE OVERNIGHT AS THE FRONT DROPS
THROUGH THE TERMINALS.
EXTENDED AVIATION OUTLOOK...TEMPORARY FLIGHT RESTRICTIONS POSSIBLE
WITH MAINLY AFTERNOON/EARLY EVENING CONVECTION SUNDAY THROUGH
MID-WEEK. OTHERWISE...VFR CONDITIONS ARE EXPECTED TO PREVAIL.
&&
.MARINE...
CONDITIONS OVER THE WATERS WILL REMAIN FAIRLY QUIET THROUGH THE
MIDDLE OF NEXT WEEK. HIGH PRESSURE WILL BUILD IN ON SATURDAY AND
THEN SHIFT INTO THE ATLANTIC ON SUNDAY WHERE IT WILL PREVAIL
THROUGH MID-WEEK. THERE WILL BE A BIT OF A NORTHEAST SURGE
SATURDAY MORNING IN THE WAKE OF A COLD FRONT DROPPING SOUTH OF THE
AREA...BUT WIND SPEEDS SHOULD BE NO GREATER THAN ABOUT 15-20 KT.
ANOTHER COLD FRONT COULD ENTER THE WATERS DURING THE MID WEEK
PERIOD. WINDS/SEAS ARE EXPECTED TO BE BELOW ANY HEADLINE CRITERIA
THROUGH THE PERIOD.
&&
.CLIMATE...
CHS HAS HIT 97 DEGREES WHICH BREAKS THE RECORD HIGH FOR THE DATE.
RECORD HIGH TEMPS TODAY...
CHARLESTON 96/1956...DOWNTOWN 97/1956...SAVANNAH 99/2012
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JRL
SHORT TERM...JAQ
LONG TERM...MTE
AVIATION...JAQ/JRL
MARINE...JAQ/JRL
CLIMATE...
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1200 PM CDT Fri May 23 2014
...Update to aviation...
.SYNOPSIS...
ISSUED AT 941 AM CDT FRI MAY 23 2014
The 23.12Z 250/500-hPa map showed a large mid to upper level disturbance
located cross western Arizona. 250-hPa 50 kt southwesterly flow continued
downstream of this feature across western Kansas. The KDDC raob was
fairly moist with a pwat of 1.13" - still between 75th percentile/+2SD.
At the sfc, KDDC WSR- 88D was indicating some showers/iso tstorms around
the region.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI MAY 23 2014
ISENTROPIC LIFT WILL REDEVELOP LATER THIS MORNING IN A MOIST
ATMOSPHERE WITH PRECIPITABLE WATER VALUES IN EXCESS OF 1 INCH AS
FAR WEST AS EASTERN COLORADO. THIS SHOULD ALLOW SHOWER AND
THUNDERSTORMS TO DEVELOP EASILY WITH INCREASING LIFT. AS THE
THUNDERSTORMS HAVE DECAYED, WE`VE FOLLOWED THE HRRR TRENDS FOR
CONVECTION THROUGH AROUND 12-14 UTC, BEFORE SIGNIFICANTLY RAMPING UP
CHANCES TOWARD 18 UTC ONCE AGAIN. EXTENSIVE CLOUDS AND OCCASIONAL
PRECIPITATION ESPECIALLY BY THIS AFTERNOON WILL RELEGATE
TEMPERATURES HOMOGENEOUSLY IN THE 70S ACROSS MOST OF THE FORECAST
AREA. CAPE VALUES WILL BE NOT AS HIGH AS ON THURSDAY AND SEVERE
THREAT IS MINIMAL AS A RESULT. SHOWERS AND THUNDERSTORMS SHOULD
PERSIST INTO THE EVENING HOURS AND FORECAST PRECIPITATION CHANCES
WERE MAXIMIZED AROUND 0 UTC. AS A RESULT OF THE RELATIVELY HUMID
CONDITIONS, LOWS TONIGHT WILL LIKELY NOT FALL BELOW 60 DEGREES IN
MOST AREAS WITH FOG BECOMING POSSIBLE TOWARD EARLY MORNING
SATURDAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 418 AM CDT FRI MAY 23 2014
THE MEDIUM RANGE MODELS CONTINUE TO SHOW AN UPPER LEVEL LOW PRESSURE
SYSTEM MOVING SLOWLY FROM THE DESERT SOUTHWEST ON SATURDAY INTO THE
CENTRAL AND SOUTHERN HIGH PLAINS BY MEMORIAL DAY. AS THE UPPER LOW
APPROACHES THE REGION, LOW LEVEL SOUTHERLY FLOW WILL CONTINUE TO
PUMP GULF MOISTURE INTO THE CENTRAL HIGH PLAINS. WEAK DISTURBANCES
ROTATING AROUND THE UPPER LOW AND EJECTING OUT OVER THE CENTRAL
PLAINS WILL BRING THUNDERSTORM CHANCES TO WESTERN AND CENTRAL KANSAS
PRETTY MUCH EVERY DAY THROUGH TUESDAY. WIND FLOW WILL NOT BE OVERLY
STRONG OVER WESTERN KANSAS THE NEXT FEW DAYS BUT MODEL SOUNDINGS
SHOW SOME DIRECTIONAL SHEAR AND THERE SHOULD BE ENOUGH INSTABILITY
FOR AT LEAST A SMALL THREAT OF SEVERE WEATHER ON SATURDAY AFTERNOON
AND EVENING.
THE MODELS BEGIN TO DIVERGE A LITTLE ON HOW QUICKLY THE UPPER LOW
CONTINUES EAST OUT OF THE HIGH PLAINS TOWARD THE MIDDLE PART OF THE
WEEK BUT CONTINUE TO MOVE IT OUT WITH AN UPPER LEVEL RIDGE BUILDING
OVER THE HIGH PLAINS. THIS WILL ULTIMATELY RESULT IN DECREASING
CHANCES FOR THUNDERSTORMS ALONG WITH A WARMING TREND.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1200 PM CDT FRI MAY 23 2014
VFR conditions through TAF pd. Local upper end MVFR possible in
heavy/isolated tstorm activity...but this will be short/limited.
Variable winds becoming southerly.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 74 62 81 61 / 70 70 60 60
GCK 72 60 81 60 / 70 70 60 60
EHA 73 57 80 57 / 60 60 60 60
LBL 74 60 79 59 / 70 70 60 70
HYS 76 63 79 62 / 70 70 40 60
P28 82 64 80 64 / 70 70 50 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Sugden
SHORT TERM...RUSSELL
LONG TERM...GERARD
AVIATION...Sugden
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
400 PM EDT FRI MAY 23 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 350 PM EDT FRI MAY 23 2014
18Z SFC ANALYSIS SHOWS CANADIAN HIGH PRESSURE DROPPING INTO THE OHIO
VALLEY TODAY BRINGING ITS DRIER AIR MASS AND COOLER TEMPS. THIS HAS
MADE FOR A PLEASANT AND COMFORTABLE DAY FOR MUCH OF EAST KENTUCKY
UNDER PARTLY TO MOSTLY SUNNY SKIES. JUST ALONG THE BORDER WITH
TENNESSEE A FEW SPRINKLES MAY OCCUR AND CONDITIONS WILL BE MORE
HUMID...AS A COLD FRONT SETTLES INTO THE SOUTH PARTS OF THE STATE.
DIFFERENCES BROUGHT BY THIS FRONT TO EAST KENTUCKY INCLUDE TEMPS
ONLY IN THE LOWER 70S ACROSS THE NORTH ALONG WITH DEWPOINTS IN THE
40S WHILE TO THE FAR SOUTH READINGS ARE IN THE MID AND UPPER 70S AND
DEWPOINTS CLOSER TO 60. NORTH TO NORTHWEST WINDS GENERALLY AT 5 TO 10
MPH...WITH SOME GUSTS TO 15 MPH...ARE FOUND THROUGH THE AREA AT THIS
TIME.
THE MODELS REMAIN IN GOOD AGREEMENT ALOFT AS THEY ALL DEPICT THE SLOW
EVOLUTION OF THE RIDGE AND TROUGH STRUCTURE THROUGH THE AREA. A
RELATIVELY SHARP TROUGH WILL SWEEP BY WELL TO THE NORTHEAST TONIGHT
ALLOWING HEIGHTS TO REBOUND INTO SATURDAY AS RIDGING EASES INTO THE
STATE FROM THE SOUTHWEST. THIS WILL ALSO PUSH THE TRACK OF ANY MINOR
MID LEVEL WAVES TO THE EAST OF THE AREA KEEPING THE FLOW PATTERN
RATHER SMOOTH OVER EAST KENTUCKY INTO SUNDAY MORNING. ON ACCOUNT OF
THE SIMILARITIES IN THE MODELS HAVE LEANED TOWARD THE LATEST RUNS OF
THE HRRR AND NAM12 FOR WEATHER SPECIFICS.
SENSIBLE WEATHER WILL FEATURE A COOLER NIGHT UNDER MOSTLY CLEAR
SKIES WITH THE FRONT OFF TO THE SOUTHWEST. A SMALL RIDGE TO VALLEY
TEMPERATURE SPLIT IS EXPECTED TO OPEN UP DURING THE EVENING AND
CONTINUE THROUGH THE NIGHT. PATCHY FOG WILL BE POSSIBLE IN THE
VALLEYS LATER TONIGHT AND INTO THE FIRST PART OF SATURDAY MORNING.
VERY PLEASANT WEATHER CAN BE EXPECTED ON SATURDAY AS COMFORTABLE
HUMIDITY LEVELS WILL CONTINUE ALONG WITH PLENTY OF SUNSHINE AND
TEMPERATURES TOPPING OUT IN THE MID TO UPPER 70S. SIMILAR CONDITIONS
TO TONIGHT/S WILL BE HAD SATURDAY NIGHT...THOUGH SFC HIGH PRESSURE
MOVING BY TO THE NORTH SHOULD YIELD MORE OF A RIDGE TO VALLEY
TEMPERATURE SPLIT BY SUNDAY MORNING THAN WE ANTICIPATE FOR TONIGHT.
AFTER AN EXTRA DAY FOR THE BOUNDARY LAYER TO DRY OUT...THE PATCHY FOG
SHOULD BE CONFINED TO MAINLY THE DEEPEST VALLEYS JUST AROUND DAWN
SUNDAY MORNING.
AGAIN USED THE BCCONSSHORT GRIDS AS A STARTING POINT FOR TEMPS...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS WITH THE BCCONSALL
FILLING THE GAP TO THE END OF THE SHORT TERM. MOST OF THE ADJUSTMENTS
WHERE MADE TO ACCOUNT FOR TERRAIN DIFFERENCES IN THE LOWS TONIGHT AND
A BIT MORE EXTENSIVELY ON SATURDAY NIGHT. AS FOR POPS...ENDED UP IN
LINE WITH THE MOS NUMBERS THROUGH SUNDAY MORNING HOLDING IN THE LOW
SINGLE DIGITS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 400 PM EDT FRI MAY 23 2014
FORECAST STILL SEEMS TO BE IN GOOD AGREEMENT FROM YESTERDAY TO
TODAY. AT 12Z SUNDAY...STRONG UPPER LEVEL RIDGING WILL BE MOVING
INTO THE OHIO VALLEY REGION...WITH A CLOSED LOW REMAINING STEADY
OVER THE SOUTHERN PLAINS DURING MUCH OF THE MID TERM. ANOTHER TROUGH
WILL FORM OVER THE NORTHEAST CONUS...WITH SEVERAL CLOSED WAVES
MOVING THROUGH OVER THE COURSE OF THE EXTENDED PERIOD. WITH THESE
TWO TROUGHS IN PLACE...EXPECT THE UPPER LEVEL RIDGE TO REMAIN THE
DRIVING FORCE THROUGH MUCH OF THE EXTENDED.
THE 300MB JET STREAM WILL REMAIN WELL TO OUR NORTH...PLAYING INTO
THE NEW ENGLAND TROUGHING DURING THE EXTENDED. MEANWHILE...WEAK FLOW
ACROSS THE OHIO VALLEY...AND SOUTHERN RIDGING...WILL MEAN WELL ABOVE
NORMAL TEMPS FOR KY INTO THE FIRST HALF OF THE WEEK. FOR MONDAY AND
TUESDAY...THERE WILL BE ENOUGH MOISTURE FLOW AND AFTERNOON
INSTABILITY THAT SOME DIURNAL ISOLATED /MONDAY/ TO LOW END SCATTERED
/TUESDAY/ SHOWER AND THUNDERSTORMS WILL BE POSSIBLE. THE GFS IS THE
MOST AGGRESSIVE WITH BRINGING MOISTURE INTO THE AREA DURING THIS
TIME...WHILE THE GEM AND ECMWF SHOW THE MAIN THREAT FOR PRECIP ON
TUESDAY AND NOT MONDAY. BASED ON THE UNCERTAINTY...AND SCATTERED
NATURE OF THIS SET UP...DECIDED TO STICK CLOSE TO THE ALLBLEND FOR
POPS DURING THIS TIME PERIOD.
BY TUESDAY EVENING...A SURFACE LOW WILL MAKES ITS WAY SE ACROSS THE
NEW ENGLAND STATES. IN DOING SO...IT WILL PUSH A SURFACE COLD FRONT
SOUTHWARD...MAKING IT INTO EASTERN KY IN THE FORM OF A BACK DOOR
FRONT TUESDAY NIGHT AND WEDNESDAY. THE GFS SEEMS TO BRING THE FRONT
THROUGH ABOUT 6 HOURS FASTER THAN THE ECMWF...WITH A BAND OF SHOWERS
AND THUNDERSTORMS PUSHING FROM NE TO SE TUESDAY EVENING THROUGH
WEDNESDAY EVENING. BEHIND THIS FRONT...SOMEWHAT DRIER AIR WILL
FILTER IN...ALONG WITH A SLIGHT COOL DOWN IN TEMPERATURES FOR
WEDNESDAY. NEITHER ONE WILL BE SIGNIFICANT. ONCE AGAIN...GIVEN THE
UNCERTAINTY BETWEEN THE TWO MODELS THIS FAR OUT...STUCK FAIRLY CLOSE
TO THE ALLBLEND SOLUTION FOR POPS.
ONCE THE FRONT MOVES THROUGH...THE SURFACE LOW WILL THEN SHIFT BACK
NORTHWARD. THIS COULD ALLOW THE OPPORTUNITY FOR THE FRONT...THOUGH
WEEK...TO PUSH BACK NORTHWARD INTO KY AS WELL LATE IN THE WEEK. THIS
COULD POSSIBLY PUSH MOISTURE BACK INTO THE CWA FOR
THURSDAY...FRIDAY...AND POINTS AFTER. UNCERTAINTY THIS FAR OUT DOES
NOT WARRANT ANY MORE THAN CHANCE POPS. DAYTIME HEATING WILL HELP TO
INITIATE ANY SHOWERS/TSTORMS...SO EXPECT BEST CHANCE POPS DURING THE
AFTERNOON/EVENING HOURS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 230 PM EDT FRI MAY 23 2014
OUTSIDE OF SOME MVFR FOG EXPECTED AT LOZ AND SME LATE TONIGHT...
CONDITIONS WILL BE VFR AND MOSTLY SKC THROUGH THE TAF PERIOD. WINDS
WILL BE GENERALLY AROUND 5 KTS AND VARIABLE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
240 PM EDT FRI MAY 23 2014
.UPDATE...
ISSUED AT 240 PM EDT FRI MAY 23 2014
STILL SOME SPRINKLES ASSOCIATED WITH THE LEADING EDGE OF THE DRIER
AIR SINKING INTO EAST KENTUCKY NOTED ACROSS OUR SOUTHERN TIER OF
COUNTIES. HAVE REFINED THE FORECAST TO REFLECT THESE AND ALSO FINE
TUNED THE SKY COVER ALONG WITH THE T/TD GRIDS PER THE LATEST OBS AND
TRENDS.
UPDATE ISSUED AT 1045 AM EDT FRI MAY 23 2014
14Z SFC ANALYSIS SHOWS CANADIAN HIGH PRESSURE BUILDING INTO THE OHIO
VALLEY AS A NOW MOSTLY DRY COLD FRONT SETTLES SOUTH THROUGH EAST
KENTUCKY. A FEW LIGHT SHOWERS WERE ACCOMPANYING THIS BOUNDARY EARLIER
IN THE MORNING BUT HAVE SINCE DRIED UP. AS SUCH...EXPECT THE FRONT TO
CLEAR THE REST OF EAST KENTUCKY BY LATE AFTERNOON REMOVING THE THREAT
OF SHOWERS AND ALLOWING THE DRIER AIR TO WORK DEEPER INTO THE CWA.
CURRENTLY DEWPOINTS VARY FROM THE UPPER 40S AND LOWER 50S IN THE
NORTH OF THE AREA TO AROUND 60 IN THE FAR SOUTH. TEMPERATURES...
MEANWHILE ARE GENERALLY IN THE MID 60S. NORTH OF THE BOUNDARY WINDS
ARE FROM THE NORTH NORTHWEST AT 5 TO 10 KTS WITH LIGHT WINDS SOUTH OF
IT. HAVE UPDATED THE FORECAST TO LOWER POPS AND FINE TUNE SKY COVER
THROUGH THE REST OF THE DAY. HAVE ALSO TWEAKED THE NEAR TERM
TEMPERATURES AND DEWPOINTS PER THE LATEST GUIDANCE...OBS...AND
TRENDS. THE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS ALONG
WITH DISSEMINATION OF THE FRESHENED ZONES AND HWO...CLEANING UP THE
MORNING THUNDER CHANCES AND FOG.
UPDATE ISSUED AT 744 AM EDT FRI MAY 23 2014
UPDATED THE FORECAST TO HANDLE AT THE ISOLATED TO SCATTERED SHOWERS
THAT ARE MOVING ACROSS THE AREA THIS MORNING. HIGH PRESSURE WILL BE
MOVING IN THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 258 AM EDT FRI MAY 23 2014
THE ARE TWO THINGS GOING ON THIS MORNING. THE FIRST IS THE IS AREAS
OF DENSE VALLEY FOG AROUND THE AREA...ESPECIALLY SOUTH OF THE HAL
ROGERS PARKWAY. THE NEXT IS THE RADAR IS SHOWING SOME WEAK RETURNS
TRYING TO MOVING INTO THE BLUEGRASS REGION IN THE NEXT FEW HOURS AND
ALSO SOME STRONGER ECHOES OVER WESTERN KENTUCKY AND CENTRAL
TENNESSEE. OTHER THAN THE HRRR...NONE OF THE MODELS ARE HANDLING
THESE ISOLATED TO SCATTERED SHOWERS. THE HRRR WAS SHOWING THESE
SHOWERS WILL BE DYING AS THEY TRY TO ENTER EASTERN KENTUCKY THIS
MORNING. WILL BE GOING WITH THE HRRR...SINCE IT IS THE ONLY MODEL
WITH A CLUE RIGHT NOW. A WEAK COLD FRONT IS LYING ALONG THE
TENNESSEE AND KY BORDER. THIS FRONT IS FORECAST TO MOVE SLOWING
SOUTH WITH TIME AS HIGH PRESSURE BUILDS INTO THE AREA. EXPECT THE FOG
TO BE BURNING OFF BETWEEN 8 AND 9 AM THIS MORNING. THERE MAY BE SOME
DEBRIS CLOUDS MOVING INTO THE AREA THIS MORNING AND THEN DECREASING
CLOUDS THIS AFTERNOON AS THE FRONT PUSHES FURTHER TO THE SOUTH. THE
CONSENSUS BLEND LOOKED PRETTY GOOD AND THEN NUDGED IT TOWARD THE GFS
MOS FOR THE HIGHS TODAY AND TOMORROW.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 359 AM EDT FRI MAY 23 2014
THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH AN
OVERALL SLOWED PATTERN AS A SHORTWAVE EXITS THE EAST COAST. A
MASSIVE RIDGE TAKES SHAPE OVER THE CENTRAL CONUS WITH THE JET STREAM
DISPLACED TO THE NORTH ALONG THE CANADIAN BORDER WITH NUMEROUS WAVES
TRACKING ALONG IT. MEANWHILE...AN UPPER CLOSED LOW SLIPS UNDERNEATH
THE RIDGE AND MOVES EAST INTO THE CENTRAL PLAINS BY MONDAY. BY
MONDAY NIGHT...A STRONGER SHORTWAVE DIVES SOUTH OVER THE EASTERN
GREAT LAKES AND INTO THE THE MID ATLANTIC STATES. BY MID WEEK...THE
PATTERN COMPLETELY STALLS WITH THE UPPER LOW OVER THE MID MS RIVER
VALLEY AND THE TROUGH OVER THE NEW ENGLAND STATES REMAINING. THE
PROMISING DETAIL HERE IS THAT BOTH THE GFS AND EURO AGREE ON
THIS...ONLY WITH MINOR DIFFERENCES. HOWEVER...THIS BEING A BLOCKING
PATTERN...THE MODELS MAY NOT HANDLE THE SET UP VERY WELL.
WITH THE UPPER LOW DRIFTING EAST ON TUESDAY AND THE FRONT ASSOCIATED
WITH THE WAVE OVER THE GREAT LAKES PUSHING SOUTH...THIS WILL SET THE
STAGE FOR SOME SHOWER AND THUNDERSTORM ACTIVITY FOR MONDAY THROUGH
THURSDAY. THIS ACTIVITY WILL ALSO LIKELY HAVE SOME DIURNAL
CHARACTERISTICS TO IT. AS WELL...DUE TO THE UNCERTAIN NATURE OF THIS
PATTERN...DID NOT GO ABOVE CHANCE POPS...ESPECIALLY FOR MONDAY AND
TUESDAY...WITH THAT UPPER LEVEL SUPPORT BARELY MAKING IT INTO THE
AREA. WITH THAT SAID...PLENTY OF WARMTH IN THIS PATTERN...DAYTIME
MAX HIGHS GETTING INTO THE 80S JUST ABOUT EVERYDAY OF THE EXTENDED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 230 PM EDT FRI MAY 23 2014
OUTSIDE OF SOME MVFR FOG EXPECTED AT LOZ AND SME LATE TONIGHT...
CONDITIONS WILL BE VFR AND MOSTLY SKC THROUGH THE TAF PERIOD. WINDS
WILL BE GENERALLY AROUND 5 KTS AND VARIABLE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JJ
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
149 PM EDT FRI MAY 23 2014
.SYNOPSIS...
ISSUED AT 332 AM EDT FRI MAY 23 2014
HIGH PRESSURE WILL BUILD INTO THE REGION BY LATER TODAY AND REMAIN
IN CONTROL OF THE WEATHER THROUGH SUNDAY. THEREFORE...CLEARING SKIES
AND MODERATING TEMPERATURES WILL MOVE IN BY THIS AFTERNOON WITH
COMFORTABLE TEMPERATURES AND LOTS OF SUNSHINE EXPECTED FOR BOTH
SATURDAY AND SUNDAY. SHOWERS AND A FEW THUNDERSTORMS THEN LOOK
LIKELY MEMORIAL DAY AS A SYSTEM DROPS DOWN FROM THE NORTHWEST.
&&
.UPDATE...
ISSUED AT 1114 AM EDT FRI MAY 23 2014
CLOUDS THINNING AWAY NICELY THIS MORNING WITH A MUCH SHALLOWER
MOISTURE PROFILE THIS MORNING PER 12Z KAPX RAOB VERSUS THURSDAY
MORNING. STILL SOME CLOUD COVER FLIRTING WITH NORTHEAST LOWER
DROPPING SOUTH/SOUTHWEST OUT OF ONTARIO...THAT MAY BE THE ONE
PROBLEM AREA THIS AFTERNOON THOUGH WITH WEAK OVERALL SUBSIDENCE
AND CONTINUED HEATING WE`LL SEE HOW MUCH CLOUD COVER WILL PREVAIL
THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 332 AM EDT FRI MAY 23 2014
...CLOUDS GRADUALLY GIVE WAY TO SUN TODAY...
HIGH IMPACT WEATHER POTENTIAL: LOW THREAT OF FROST FOR INTERIOR
NORTHERN LOWER TONIGHT.
PATTERN SUMMARY: NORTHWEST FLOW ON CONTROL OF OUR REGION/S WEATHER
AS OF THIS WRITING WITH LOW HEIGHT ANOMALY OVER EASTERN
CANADA...WITH UPSTREAM HEIGHTS BUILDING OVER THE WESTERN UNITED
STATES NORTH OF A STATIONARY CUTOFF LOW ACROSS THE SOUTHWESTERN
PORTION OF THE COUNTRY. LAST IN A SERIES OF SHORTWAVES MAKING ITS
CLOSEST APPROACH TO NORTHERN MICHIGAN AS OF THIS WRITING...HELPING
SPAWN A FEW SPRINKLES ALONG THE COAST OF NORTHEAST LOWER MICHIGAN
AND NORTHERN LAKE HURON. AS THIS FEATURE CONTINUES TO MOVE SOUTH
AND EAST...SHORTWAVE RIDGING WILL BUILD IN IT/S PLACE. THIS IS
MANIFESTED AS A MODEST 1023 MB HIGH ALONG THE ONTARIO/MINNESOTA
BOARDER...WHICH WILL SLIDE INTO NORTHERN MICHIGAN THROUGH THE
UPCOMING FORECAST PERIOD. THIS SETUP SUGGESTS FAIR WEATHER...BUT WE
HAVE SOME LLEVEL STRATUS OVERHEAD ASSOCIATED WITH NEARBY SHORTWAVE
THAT WILL BE RELUCTANT TO LEAVE AND THUS COMPLICATE THE EARLY
PORTION OF THIS FORECAST THIS AM. BEYOND THIS...ATTENTION TURNS TO
WHAT LOOKS TO BE THE POTENTIAL FOR A CHILLY /FROSTY?/ NIGHT FRIDAY
NIGHT.
THROUGH DAYBREAK: STILL TRACKING AREA OF SPRINKLES ALONG THE COAST
OF NORTHEAST LOWER...THESE WILL CONTINUE TO SINK SOUTH WITH LOW
CLOUDS CONTINUING TO EXPAND ACROSS NORTHERN LOWER. ANY SPRINKLE
THREAT SHOULD END BY 09-10Z...WITH A LITTLE PATCHY DRIZZLE/SPRINKLE
ACTIVITY ALSO NOT OUT OF THE QUESTION THROUGH DAYBREAK ACROSS THE
HIGHER TERRAIN OF NORTHERN LOWER.
TODAY: PRIMARY CONCERN TODAY REVOLVES AROUND CLOUD COVER...IT/S
EROSION AND IMPACTS ON TEMPERATURES. PRETTY BIG MODEL DISPARITIES
IN HANDLING THE BOUNDARY LAYER MOISTURE FIELD THIS MORNING WITH THE
NAM MUCH MORE AGGRESSIVE IN MORNING CLEARING WHILE THE RAP AND OUR
IN HOUSE LOCAL WRF WOULD LIKE TO MAINTAIN LLEVEL SATURATION OVER
MUCH OF NORTHERN LOWER AT LEAST THROUGH THE NOON HOUR. TRACKING
BACK THIS CLOUD DECK 24 HOURS TO A LOCATION JUST WEST OF JAMES BAY
SUGGESTS A PRETTY SLOW CLEARING PROCESS...AND THAT IS IN LINE WITH
PATTERN RECOGNITION OF SOME MOISTURE GETTING TRAPPED BENEATH
DEVELOPING SUBSIDENCE INVERSION...AS WELL AS RECENT GFS LAMP
GUIDANCE. THUS...WILL DELAY CLEARING UNTIL ABOUT NOON OVER NORTHERN
LOWER...AND DURING THE MID MORNING OVER EASTERN UPPER. THE SUN WILL
EVENTUALLY WIN OUT...HOWEVER...WITH SKIES BECOMING MOSTLY CLEAR
TOWARDS EVENING.
TEMPERATURES /CONFIDENCE: MODERATE-HIGH/: EXPECT CLOUDS TO HAVE SOME
IMPACT ON TEMPERATURES...LIMITING THE DIURNAL HEATING WINDOW.
STILL...DAYS ARE LONG AND T8S AROUND +5-6 SUGGEST MID 60S FOR
HIGHS...AND EXPECT THAT WE/LL REACH THESE VALUES...BUT LATE IN THE
DAY.
TONIGHT: HIGH PRESSURE SETTLES OVERHEAD WITH VERY QUIET CONDITIONS
EXPECTED. WITH AMPLIFYING LONGWAVE RIDGE TO OUR WEST...
NAM/GFS/ECMWF WANT TO SPILL SOME MID/UPPER LEVEL MOISTURE OVER THE
ARRIVING MID LEVEL RIDGING...IMPACTING EASTERN UPPER AND FAR
NORTHERN LOWER AFTER MIDNIGHT. WILL INDICATE PARTLY CLOUDY SKIES
HERE...WITH MOSTLY CLEAR CONDITIONS TO THE SOUTH OF THIS. ONLY
POTENTIAL IMPACT OF THIS CLOUD COVER MAY BE TO KEEP A LID ON
TEMPERATURES FALLING TOO FAR IN THESE LOCALES.
TEMPERATURES /CONFIDENCE: MODERATE-HIGH/: CHILLY NIGHT IN STORE WITH
AFTERNOON DEWPOINTS LIKELY TO MIX OUT INTO THE UPPER 30S BY LATE IN
THE DAY IN SOME OF OUR INTERIOR DRY SPOTS. THIS WILL GIVE US PLENTY
OF ROOM TO COOL OVERNIGHT AS HIGH PRESSURE BUILDS OVERHEAD.
COMPLICATING FACTORS WILL BE POTENTIAL CLOUDS NORTH...AND SOME
RESIDUAL GRADIENT ALONG THE COAST OF NORTHEAST LOWER. STILL...
LOCALES FROM CAD TO GOV SHOULD BE ABLE TO CROSS INTO THE UPPER
30S...AND HAVE SOME CONCERNS WE MAY GO FURTHER THAN THIS DEPENDING
ON HOW TEMPS/DEWPOINTS EVOLVE TODAY /LATER CLEARING LIMITING
HIGHS/. WORST CASE SCENARIO /SIMILAR TO MAV/ WOULD ALLOW FOR A
LITTLE PATCHY FROST FOR THE INTERIOR /NO FREEZE EXPECTED/...BUT
EXPECTATIONS AT THIS TIME IS A LITTLE WARMER THAN THIS /ALTHOUGH
COOLER THAN INHERITED LOWS/. WILL PAINT UPPER 30S TO LOWER 40S WITH
NO HWO MENTION THIS GO AROUND.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 332 AM EDT FRI MAY 23 2014
...NICE START TO THE MEMORIAL DAY WEEKEND...
...HIGH IMPACT WEATHER POTENTIAL: NONE TO VERY LOW.
RIDGING AT THE SURFACE AND ALOFT PROMISES TO BRING PLEASANT LATE
SPRING CONDITIONS TO THE REGION SATURDAY INTO SUNDAY.
HOWEVER...NORTHERN STREAM ENERGY TRACKING ACROSS CANADA POSSIBLY IN
COMBINATION WITH A CUTOFF UPPER LOW EVIDENT ON WATER VAPOR IMAGERY
WILL LIKELY BRING SHOWERY CONDITIONS TO NORTHERN MICHIGAN FOR YOUR
MEMORIAL DAY (SORRY ABOUT THAT ONE). MORE RIDGING THEN BUILDS IN FOR
TUESDAY THROUGH THURSDAY LIKELY BRINGING ANOTHER DECENT STRETCH OF
WEATHER TO THE REGION.
SATURDAY INTO SUNDAY...SURFACE RIDGE CONTINUES TO MOVE ACROSS THE
REGION WITH HEIGHTS STEADILY RISING. A WEAK AND MOISTURE STARVED
SHORT WAVE SNEAKS UNDER THE RIDGE SATURDAY...WITH ONLY A PERIOD OF
MID LEVEL CLOUDS EXPECTED. OTHERWISE...CLEAR TO PARTLY CLOUDY SKIES
WITH PLEASANT TEMPERATURES ANTICIPATED. HIGHS MAINLY IN THE 70S
(EVEN A FEW LOWER 80S SUNDAY AFTERNOON) AND LOWS IN THE MIDDLE 40S
TO LOWER 50S.
SUNDAY NIGHT THROUGH MONDAY NIGHT...THE RIDGE TEMPORARILY BREAKS
DOWN ALLOWING A SYSTEM CRUISING ACROSS CANADA TO DROP DOWN FROM THE
NORTHWEST. A NICE LITTLE JET CORE IS SHOWN TO ACCOMPANY THIS FEATURE
SO IN COMBINATION WITH DAYTIME HEATING (AND POSSIBLY ENERGY FROM THE
WEAKENING CUTOFF UPPER LOW FROM THE SOUTHWEST)...SHOWERS AND
THUNDERSTORMS LOOK LIKELY. IN ADDITION...A NARROW THETA-E RIDGE
MOVES ACROSS THE REGION. EXPECT THE BEST CHANCE FOR SHOWERS AND
STORMS TO BE MONDAY AFTERNOON AND EVENING. IT IS STILL TOO EARLY TO
PIN DOWN SEVERE POTENTIAL BUT WILL HAVE TO MONITOR THE EVOLUTION OF
THE POSSIBLE JETLET AS A FEW STORMS MAY HAVE THE POTENTIAL TO BE ON
THE STRONGER SIDE.
TUESDAY THROUGH THURSDAY...PERHAPS SOME LOW CLOUDS AROUND TO START
OFF TUESDAY (THOUGH OVER LAKE INSTABILITY IS MUCH LESS THAN OUR
LATEST GO AROUND). OTHERWISE...RENEWED RIDGING AT THE SURFACE AND
ALOFT SHOULD LEAD TO ANOTHER STRETCH OF FINE LATE SPRING WEATHER.
HIGHS RANGING FROM THE MIDDLE 60S NORTH TO THE MIDDLE 70S SOUTH AND
LOWS IN THE MIDDLE 40S TO MIDDLE 50S (WHICH IS ALMOST PERFECT
SLEEPING WEATHER IF YOU ASK ME).
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 146 PM EDT FRI MAY 23 2014
MINIMAL AVIATION CONCERNS THROUGH SATURDAY MORNING WITH VFR
CONDITIONS EXPECTED TO PREVAIL.
&&
.MARINE...
ISSUED AT 332 AM EDT FRI MAY 23 2014
SUMMARY: HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES REGION TODAY
AND TONIGHT...WITH NORTHWESTERLY WINDS GRADUALLY DECREASING. HIGH
PRESSURE WILL REMAIN OVERHEAD THROUGH SATURDAY BEFORE SHIFTING
SOUTH AND EAST OF THE REGION BY SUNDAY WITH LOW PRESSURE ARRIVING
SUNDAY NIGHT/MONDAY...WITH A ROUND OF SOUTHWEST WINDS BEFORE WINDS
SHIFT AGAIN TO THE NORTHWEST BY THE MIDDLE OF NEXT WEEK.
HEADLINES: MARGINAL SMALL CRAFT CONDITIONS POSSIBLE NEAR PRESQUE
ISLE FOR A TIME TODAY...OTHERWISE...HEADLINE FREE CONDITIONS LOOK TO
BE IN STORE THROUGH THE UPCOMING WEEKEND.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JPB
SYNOPSIS...AS
SHORT TERM...ARNOTT
LONG TERM...AS
MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS DULUTH MN
351 PM CDT FRI MAY 23 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 350 PM CDT FRI MAY 23 2014
AN UPPER LEVEL RIDGE AND SURFACE HIGH HAS KEPT THE NORTHLAND UNDER
MOSTLY SUNNY SKIES WITH WARM TEMPERATURES TODAY.
WAA TONIGHT...ALONG WITH INCREASING INSTABILITY AND STEEPER LAPSE
RATES MAY LEAD TO SOME SHOWERS OVER PORTIONS OF OUR
WESTERN/NORTHERN CWA. SHOWERS AND THUNDERSTORMS HAVE FIRED OVER
FAR WESTERN MINNESOTA THIS AFTERNOON...AND THE LATEST HRRR DEPICTS
THIS AND HAS IT DIMINISHING WITH LOSS OF HEATING AND AS IT MOVE
AWAY FROM THE BETTER INSTABILITY. THE LATEST WRF-NMM ALSO DEPICTS THIS
ACTIVITY AND HAS IT DISSIPATING BEFORE IT REACHES OUR CWA. WE WILL
LEAVE IT OUT EARLY THIS EVENING...THEN KEEP SOME SMALL POPS LATER
TONIGHT.
LOWER STABILITY WILL RESIDE OVER FAR NORTHERN MINNESOTA
SATURDAY...AND WE KEPT A MENTION OF SOME SHOWERS OR THUNDERSTORM
THERE. MOST AREAS WILL SEE PARTLY TO MOSTLY SUNNY SKIES THOUGH AND
TEMPERATURES A BIT WARMER THAN TODAY. WE THINK THE SOUTHWEST FLOW
WILL BE STRONG ENOUGH TO KEEP A LAKE BREEZE FROM FORMING AT THE
HEAD OF THE LAKE AND ALONG THE SOUTH SHORE FOR MUCH OF THE DAY.
HOWEVER...ONE MAY BE ABLE TO DEVELOP LATE IN THE AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 350 PM CDT FRI MAY 23 2014
GOOD CONTINUITY FROM PREVIOUS FCST WITH A SOMEWHAT SPLIT FLOW IN THE
MID LVLS THIS PERIOD. THERE ARE TWO KEY FEATURES OF NOTE IN THE NEXT
5 TO 7 DAYS. FIRST...A SLOW MOVING CLOSED LOW OVER THE SRN ROCKIES
WILL TRACK INTO THE SRN PLAINS BY MIDWEEK. SECOND...A WEAK FRONTAL
BDRY ACCOMPANIED BY A SHORTWAVE TROF WILL SLIDE OVER THE CWA AMIDST
A DEVELOPING RIDGE. THIS SECOND FEATURE WILL BRING A PERIOD OF
SHOWERS/STORMS TO THE NORTHLAND MAINLY SUNDAY AND SUNDAY NIGHT.
THERE ARE DIFFERENCES IN HOW FAST INITIAL PRECIP MOVES INTO THE AREA
HOWEVER GOOD AGREEMENT EXISTS IN THE MASS FIELDS TO HAVE MODERATE
CONFIDENCE IN THE FCST. GEM REMAINS AN OUTLIER SIMILAR TO YESTERDAY
SO ITS OUTPUT WAS GIVEN LOWER CONSIDERATION. MAIN CHANGE TO
YESTERDAYS FCST WAS TO PUSH PRECIP OUT OF THE REGION MORE QUICKLY
MONDAY AS FRONTAL BDRY HEADS SOUTH AND SFC HIGH BUILDS INTO THE
AREA. BUILDING MID LVL RIDGE TUESDAY SHOULD ASSIST WITH STRENGTHENING
OF SFC HIGH AND WEDGE OF COOL DRY AIR ADVECTING DOWN LAKE INTO TWIN
PORTS. LATER FCSTS MAY NEED TO LOWER TEMPS/DEWPOINTS DURING THIS
TIME. WILL KEEP MON NIGHT THROUGH WED NIGHT DRY UNTIL NEXT POTENTIAL
FOR PRECIP ARRIVES LATE WEEK. TEMPS REMAIN ABOVE CLIMO EXCEPT NEAR
IMMEDIATE LAKEFRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1210 PM CDT FRI MAY 23 2014
VFR THROUGH THE PERIOD WITH TWO EXCEPTIONS... NEAR KINL AND KDLH.
RETURN FLOW OF MOISTURE AROUND THE PERIPHERY OF SFC HIGH WILL
ALLOW SLIGHT CHC/CHC OF SHOWERS LATE TONIGHT/TOMORROW AT KINL. MAY
NEED TO AMEND KDLH FOR BR/FG POTENTIAL AFTER 08Z TONIGHT AS FCST
SNDGS SHOW FAVORABLE HYDROLAPSE DEVELOPING FOR A BRIEF TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 48 75 56 78 / 10 10 10 20
INL 50 79 58 74 / 20 20 30 60
BRD 52 80 59 81 / 10 10 20 40
HYR 43 78 54 81 / 0 0 0 10
ASX 43 77 53 80 / 0 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MELDE
LONG TERM...CANNON
AVIATION...CANNON
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1242 PM CDT FRI MAY 23 2014
.SYNOPSIS...
ISSUED AT 300 AM CDT FRI MAY 23 2014
A MESOSCALE VORTICITY CENTER APPEARS LOCATED NEAR LAMAR CO FROM
EARLIER MCS WHICH DEVELOPED AND MOVED NORTHEAST FROM EASTERN NEW
MEXICO. THE LEADING EDGE OF THIS CONVECTION HAS PERSISTED ACROSS
NORTHWEST KANSAS AND SOUTHWEST NEBRASKA WITH A SLOW PROPAGATION TO
THE NORTH. DUE TO SLOW OVERALL STORM MOVEMENT...HEAVY RAINFALL
INDICATED BY RADAR FROM SERN CHASE INTO HAYES COUNTY. TEMPERATURES
ACROSS WRN NEBR RANGED IN THE UPPER 50S TO LOWER 60S WITH DEWPOINTS
IN THE MID 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CDT FRI MAY 23 2014
A CLOSED UPPER LOW WAS LOCATED IN FAR SRN CALIF EARLY THIS MORNING
WITH UPSTREAM RIDGING FROM THE LOWER MISSISSIPPI VALLEY
NORTHWESTWARD INTO WYOMING. MAIN AREA OF CONVECTION FROM WESTERN
KANSAS INTO SWRN NEBR WILL CONTINUE TO MOVE NORTH PRIOR TO 12Z. AN
APPARENT MVC NEAR LAMA CO SHOULD CONTINUED LIFT NORTHEAST TODAY
ALONG WITH A MID LEVEL DISTURBANCE. BOTH THE NAM AND GFS DEVELOP
PRECIPITATION BOTH TODAY AND TONIGHT ACROSS WRN NEBR. THE HIGHER
LIKELY POPS TODAY INTO THIS EVENING ARE PLACED ACROSS THE SOUTHEAST
PANHANDLE INTO SOUTHWEST NEBR. NORTHEAST COUNTIES SHOULD REMAIN DRY
TODAY WITH A SLIGHT CHANCE BY LATE AFTERNOON. IN ADDITION...BOTH THE
RAP AND HRRR MODELS INDICATE SHOWER AND THUNDERSTORM DEVELOPMENT
SHOULD OCCUR QUICKLY AFTER 15Z FROM SWRN NEBR INTO THE WESTERN
SANDHILLS. DUE TO WEAK DEEP LAYER SHEAR LESS THAN 20 KTS...STRONG OR
SEVERE STORMS ARE UNLIKELY. STORM MOTION TO THE NORTH AND NORTHEAST
WILL ONLY BE 10 TO 15 MPH...WITH HEAVY RAINFALL POSSIBLE WITH
TRAINING CELLS.
SKIES TO BE MOSTLY CLOUDY TODAY WITH HIGHS FROM NEAR 70 IN SWRN NEBR
TO AROUND 75 IN THE NORTHEAST WHERE A BIT MORE SUN EXPECTED.
CHANCES FOR SHOWERS AND THUNDERSTORMS FALL TO AROUND 30 PERCENT
AFTER MIDNIGHT TONIGHT...WITH SLIGHTLY BETTER CHANCES FROM CENTRAL
KANSAS INTO EASTERN NEBRASKA. WITH MAINLY CLOUDY SKIES AND DEWPOINTS
IN THE MID 50S...OVERNIGHT LOWS WILL MOSTLY RANGE IN THE UPPER 50S.
THE UPPER LEVEL LOW MEANWHILE WILL MOVE SLOWLY INTO CENTRAL ARIZONA
OVERNIGHT WITH A CONTINUED FETCH OF GULF MOISTURE FROM THE SOUTHERN
INTO THE CENTRAL PLAINS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 300 AM CDT FRI MAY 23 2014
CLOSED UPPER LEVEL LOW PRESSURE SYSTEM WILL PROGRESS VERY SLOWLY
TO THE EAST ACROSS THE SOUTHERN PLAINS THROUGH THE PERIOD. OUR
AREA WILL CONTINUE TO BE INFLUENCED FROM THE SYSTEM THROUGH AT
LEAST TUESDAY...WITH SCATTERED SHOWERS AND THUNDERSTORMS. PLENTY
OF GULF MOISTURE WILL BE IN PLACE SO SOME HEAVY RAIN IS POSSIBLE
WHERE STORMS DEVELOP. OVERALL SEVERE THREAT IS LOW DUE TO WEAK
WINDS ALOFT...BUT THIS WILL AID IN THE POSSIBILITY OF HEAVY
RAINFALL DUE TO SLOW MOVING STORMS. COVERAGE WILL BE
SCATTERED...AS NO REAL BOUNDARY TO FOCUS CONVECTION ON. THE
EXCEPTION WILL BE SUNDAY AFTERNOON AND EVENING...WHEN A WEAK COLD
FRONT WILL SAG INTO NORTHERN NEBRASKA. MAY SEE A BIT MORE COVERAGE
OF STORMS INVOF OF THE FRONT. WILL CONTINUE TO BLANKET THE AREA
WITH 30 POPS FOR MUCH OF THE WEEKEND...BUT WILL HAVE A SLIGHTLY
HIGHER 40 POP ACROSS THE NORTH SUNDAY NEAR THE FRONT.
WITH THE GULF MOISTURE WELL ESTABLISHED ACROSS THE
PLAINS...TEMPERATURES WILL BE MILD. THERE WILL BE LOW STRATUS
CLOUDS AROUND AT TIMES...BUT ALL MODELS INSIST THAT THERE WILL BE
AT LEAST SOME SUNSHINE EACH DAY THROUGH THE MEMORIAL DAY WEEKEND.
SHOULD SEE HIGHS IN THE 70S SATURDAY...AND WITH POSSIBLY MORE
SUNSHINE SUNDAY...HIGHS COULD REACH AROUND 80. LITTLE CHANGE IN
TEMPERATURES INTO MOST OF NEXT WEEK...WITH HIGHS UPPER 70S TO
LOWER 80S. LOWS WILL BE MILD...IN THE MID 50S TO LOWER 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1241 PM CDT FRI MAY 23 2014
SHOWERS AND EMBEDDED THUNDERSTORMS MOVING INTO THE KLBF TERMINAL
AT THE MOMENT. ACTIVITY THROUGH THE AFTERNOON...WITH MVFR AND AT
TIMES IFR CONDITIONS WITH SHOWER ACTIVITY. TONIGHT THE CHANCE
CONTINUES FOR ISOLATED/SCATTERED SHOWERS AND THUNDERSTORMS. UNSURE
ON COVERAGE AND WILL NOT MENTION IN TAF AT THIS TIME...HOWEVER
WITH THE RICH MOISTURE ENVIRONMENT...EXPECT FOG TO REDEVELOP. IF
THERE ARE SHOWERS...FOG MAY BE LESS A CONCERN.
FURTHER NORTH VFR CONDITION FOR MUCH OF THE DAY. ACTIVITY WILL
SLOWLY PUSH NORTH FOR THE AFTERNOON...AND EXPECT SOME SHOWERS TO
PUSH INTO THE KVTN. LATER TAF UPDATES WILL DEFINE TIMES...HOWEVER
FOR NOW WILL HAVE VCSH IN THE TAF AT HIGHEST CONFIDENCE OF
ACTIVITY IN THE AREA. SIMILAR TO KLBF...FOG COULD BE AND
ISSUE...ALTHOUGH LOWER VISBY EXPECTED SOUTH AND EAST OF KVTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...TAYLOR
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
156 PM EDT FRI MAY 23 2014
.SYNOPSIS...
SURFACE AND UPPER LEVEL LOW PRESSURE SYSTEMS MOVING ACROSS THE
NORTH COUNTRY TODAY WILL BRING SLOW MOVING SCATTERED SHOWERS WITH
ISOLATED THUNDERSTORMS TO THE AREA. NORTHWEST UPPER LEVEL FLOW
THROUGH THE HOLIDAY WEEKEND WILL CONTINUE THE UNSETTLED WEEKEND
WITH CHANCES FOR AFTERNOON SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 1253 PM EDT FRIDAY...MAIN CONCERN THIS AFTERNOON/EVENING IS
SLOW-MOVING NATURE OF MODERATE TO LOCALLY HEAVY RAIN
SHOWERS...ESPECIALLY ACROSS ADDISON AND RUTLAND COUNTIES IN
VERMONT.
STATIONARY LOW PRESSURE SYSTEM CENTERED OVER THE SRN CHAMPLAIN
VALLEY WILL CONTINUE TO BRING OVERCAST CONDITIONS AND PERSISTENT
PERIODS OF SHOWER ACTIVITY THIS AFTERNOON INTO THIS EVENING. IT
APPEARS THAT REMNANT OCCLUDED FRONT EXTENDING SWD ACROSS SWRN VT
INTO WRN MA WILL PROVIDE A FOCUS FOR ADDITIONAL SHOWER DEVELOP
THIS AFTERNOON...WITH A SLIGHT CHANCE OF A TSTM FOR
RUTLAND/WINDSOR COUNTIES GIVEN FORECAST WEAK SBCAPE VALUES IN 12Z
NAM MODEL SOUNDINGS. THE HRRR /BTV-4KM INDICATE ADDITIONAL SHOWER
DEVELOPMENT ACROSS CENTRAL VT MOVING SLOWLY SWD ACROSS
RUTLAND/WINDSOR COUNTIES THIS AFTN. RADAR TRENDS HAVE SHOWN A
GRADUAL INCREASE IN AREAL COVERAGE OF SHOWERS...WITH RAINFALL
RATES OF 0.2-0.4"/HR ACROSS SRN CHITTENDEN AND ADDISON COUNTIES
WITH THE MOST INTENSE ACTIVITY. FLASH FLOOD GUIDANCE SUGGESTS
2-3"/6-HR WILL BE NEEDED FOR ANY SIGNIFICANT FLOOD THREAT...SO
GIVEN RAIN RATES IT WILL DEPEND ON PERSISTENCE/STATIONARITY OF
INDIVIDUAL SHOWERS OVER THE NEXT SEVERAL HOURS.
VAD WIND PROFILES AND NAM FORECAST SOUNDINGS INDICATE SFC- 250MB
FLOW BELOW 10 KTS AT ALL LEVELS...WHICH CERTAINLY WILL SUPPORT
SLOW MOVING SHOWERS. CONTINUED WITH HEAVY RAIN WORDING FOR
CENTRAL/S-CENTRAL VT THIS AFTERNOON AND EVENING. THE ONLY
MITIGATING FACTOR IS THAT PW VALUES ARE ONLY AROUND 0.75"...AFTER
BEING 1.1-1.2" YESTERDAY. WE/LL CONTINUE TO MONITOR SHORT-TERM
TRENDS FOR ANY LOCALIZED FLOODING CONCERNS...WHICH WILL BE
CENTERED ON ADDISON AND RUTLAND COUNTIES.
WITH LOW OVERCAST IN PLACE...TEMPERATURES WILL NOT RISE
SIGNIFICANTLY THIS AFTN AND HIGH TEMP FORECAST IS A FEW DEGREES
BELOW THE MOS CONSENSUS. LOOKING FOR READINGS 62-64F IN THE
CHAMPLAIN VALLEY...65-69F IN THE ST. LAWRENCE VALLEY WITH A BIT
MORE SUNSHINE...WHILE HOLDING IN THE UPR 50S FOR THE NRN ADIRONDACKS AND
MOST SECTIONS EAST OF THE GREEN MTN SPINE.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SUNDAY/...
AS OF 515 AM EDT FRIDAY...UPPER LEVEL TROF FINALLY SHIFTS
SOUTHEAST OF THE NORTH COUNTRY OVERNIGHT AND COVERAGE OF SHOWERS
WILL DECREASE OVERNIGHT. SOME SHOWERS MAY AGAIN LINGER THROUGH
THE OVERNIGHT THOUGH...SIMILAR TO THE LAST COUPLE NIGHTS.
SOUTHERN AND EASTERN VERMONT WILL HAVE THE BEST CHANCE FOR THIS.
SKIES REMAIN CLOUDY AND TEMPERATURES WILL BE MILD. DURING THE
DAYTIME HOURS ON SATURDAY NORTHWESTERLY MID LEVEL FLOW DEVELOPS.
THERE SHOULD BE SOME SUN WITH DRIER AIR MOVING INTO THE REGION.
THIS WILL CAUSE SOME INSTABILITY...THOUGH MINOR...AND SOME
AFTERNOON SHOWERS AND ISOLATED THUNDERSTORMS ARE ONCE AGAIN
EXPECTED. DUE TO SOME SUN IN THE FORECAST...AFTERNOON MAX TEMPS
WILL BE CLOSER TO SEASONAL NORMALS ON SATURDAY. SURFACE WINDS
WILL ALSO BE A BIT STRONGER WITH GRADIENT FLOW SUPPORTING NW
WINDS AROUND 10 MPH THROUGH THE DAYTIME HOURS. DAYTIME SHOWERS
AND THUNDERSTORMS WILL DISSIPATE OVERNIGHT AND FLOW WEAKENS AS
WELL. PARTLY CLOUDY SKIES WILL BE IN PLACE...AND RESULTING IN MIN
TEMPERATURES NEAR SEASONAL NORMALS. SURFACE HIGH BEGINS TO RIDGE
INTO THE NORTH COUNTRY ON SUNDAY...THOUGH NORTHWESTERLY UPPER
LEVEL FLOW WILL CONTINUE. WEAK UPPER LEVEL DISTURBANCES PASSING
THROUGH PROGRESSIVE FLOW WILL ONCE AGAIN BRING POSSIBILITY OF
SOME AFTERNOON SHOWERS...HAVE CHANCE POPS MENTIONED AT THIS TIME.
TEMPERATURES WILL BE SLIGHTLY WARMER THAN SEASONAL NORMALS WITH
SUN HELPING TO WARM THE AREA.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 345 AM EDT FRIDAY...THE MAIN SURFACE WEATHER FEATURES WILL
BE A WARM FRONT MOVING IN SUNDAY NIGHT PASSING EARLY MONDAY AND A
COLD FRONT PASSING EARLY TUESDAY...BOTH WITH CHANCES OF SHOWERS
FOLLOWED BY MAINLY DRY WEATHER WED AND THU. THROUGH THE PERIOD
EXPECT CLOSE TO AVERAGE TEMPS FOR THIS TIME OF YEAR THOUGH IT
MIGHT BE A BIT COOLER ON WED.
THE UPPER LEVEL PATTERN FOR THE PERIOD WILL BE A PERSISTENT
NORTHWEST TO NORTH FLOW OVER OUR AREA WITH A COLD TROF/CUTOFF LOW
DEVELOPING IN THE CANADIAN MARITIMES AND HEAT RIDGE IN THE CENTER
OF THE COUNTRY.
CONFIDENCE RISING IN THE FORECAST AS MODELS ARE COMING INTO
BETTER AGREEMENT WITH THE EVOLUTION OF THE TROF/CUTOFF LOW IN THE
MARITIMES WITH THE ECMWF COMING BETTER IN LINE WITH THE GFS.
SUNDAY NIGHT A DEVELOPING WARM FRONT WILL BRING A CHANCE OF
SHOWERS WITH TEMPS IN THE 50S.
MONDAY AFTER SOME MORNING SHOWERS THE AREA GETS MORE INTO THE
WARM SECTOR WITH 85O TEMPS REACHING AS HIGH AS +10 TO +12C, SO
HIGH TEMPS WELL INTO THE 70S, PERHAPS NEAR 80. COULD BE A ROGUE
THUNDERSTORM BUT INSTABILITY LOOKS WEAK AT THIS POINT.
TUESDAY 850 TEMPS DROPPING WITH ABOUT +8C GIVING TEMPS IN THE
LOWER 70S WITH A CHANCE OF SHOWERS AS A COLD FRONT DROPS
SOUTHWARD THROUGH THE AREA.
WED...850 TEMPS DOWN NEAR 0C EARLY RECOVER UP TO ABOUT 5-7C SO
TEMPS WILL BE IN THE 60S TO AROUND 70 UNDER A COOL NORTHERLY FLOW
WITH LOTS OF FAIR WEATHER CUMULUS. ONLY EXCEPTION WILL BE CHANCE
OF A SHOWER ESPECIALLY IN THE NORTHEAST. LOW TEMPS DOWN IN THE
40S, PERHAPS INTO THE 30S IN THE COLD SPOTS.
THU...850 TEMPS BACK UP TO 8-10C WITH TEMPS IN THE 70S AGAIN WITH
A DRY NORTHERLY FLOW.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 18Z SATURDAY...QUASI-STATIONARY SFC LOW KEEPS MVFR/IFR
CONDITIONS ACROSS THE CPV AND VT...WITH VFR/MVFR AT KMSS AND KSLK
FOR THE REST OF TODAY. SHOWERS LGT TO MOD IN INTENSITY CONTINUE
TO ROTATE ABOUT THE LOW...WITH MORE CONVECTIVE ACTIVITY TOWARD
THE SOUTH...KRUT COULD SEE SOME THUNDER THIS AFTN.
MVFR/IFR EXPECTED TO PERSIST AT KBTV...KPBG AND KMPV THROUGH THIS
EVENING. KPBG MAY SEE BREAKS OF VFR BTWN SHOWERS. KSLK CURRENTLY
VFR WILL DETERIORATE TO MVFR WITH SHOWERS...WHILE KMSS HAS LESS
CHC FOR PRECIP WITH VCSH.
OVRNGT...LLVL MOISTURE WILL LEAD TO MVFR/IFR BR/FG AND CIGS FROM
LOW STRATUS DECK. EXPECT CONDITIONS TO GRADUALLY IMPROVE TO
VFR/MVFR AT ALL TAF SITES AFTER SUNRISE SATURDAY AS THE SFC LOW
IS EXPECTED TO FINALLY MOVE OUT OF THE NORTH COUNTRY.
OUTLOOK 18Z SATURDAY THROUGH WEDNESDAY...
18Z SAT THRU 00Z MON...VFR WITH SCT MVFR SHOWERS SATURDAY
AFTERNOON...AND ISOLATED SHOWERS SUNDAY AFTERNOON.
00Z MON THRU 12Z WEDENSDAY...SEVERAL UPPER LVL DISTURBANCES WILL
KEEP THREAT OF SCT MVFR SHOWERS ACROSS THE REGION.
12Z WEDNESDAY ONWARD...VFR CONDITIONS UNDER HIGH PRESSURE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...BANACOS
SHORT TERM...NEILES
LONG TERM...SISSON
AVIATION...KGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1257 PM EDT FRI MAY 23 2014
.SYNOPSIS...
SURFACE AND UPPER LEVEL LOW PRESSURE SYSTEMS MOVING ACROSS THE
NORTH COUNTRY TODAY WILL BRING SLOW MOVING SCATTERED SHOWERS WITH
ISOLATED THUNDERSTORMS TO THE AREA. NORTHWEST UPPER LEVEL FLOW
THROUGH THE HOLIDAY WEEKEND WILL CONTINUE THE UNSETTLED WEEKEND
WITH CHANCES FOR AFTERNOON SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 1253 PM EDT FRIDAY...MAIN CONCERN THIS AFTERNOON/EVENING IS
SLOW-MOVING NATURE OF MODERATE TO LOCALLY HEAVY RAIN
SHOWERS...ESPECIALLY ACROSS ADDISON AND RUTLAND COUNTIES IN
VERMONT.
STATIONARY LOW PRESSURE SYSTEM CENTERED OVER THE SRN CHAMPLAIN
VALLEY WILL CONTINUE TO BRING OVERCAST CONDITIONS AND PERSISTENT
PERIODS OF SHOWER ACTIVITY THIS AFTERNOON INTO THIS EVENING. IT
APPEARS THAT REMNANT OCCLUDED FRONT EXTENDING SWD ACROSS SWRN VT
INTO WRN MA WILL PROVIDE A FOCUS FOR ADDITIONAL SHOWER DEVELOP
THIS AFTERNOON...WITH A SLIGHT CHANCE OF A TSTM FOR
RUTLAND/WINDSOR COUNTIES GIVEN FORECAST WEAK SBCAPE VALUES IN 12Z
NAM MODEL SOUNDINGS. THE HRRR /BTV-4KM INDICATE ADDITIONAL SHOWER
DEVELOPMENT ACROSS CENTRAL VT MOVING SLOWLY SWD ACROSS
RUTLAND/WINDSOR COUNTIES THIS AFTN. RADAR TRENDS HAVE SHOWN A
GRADUAL INCREASE IN AREAL COVERAGE OF SHOWERS...WITH RAINFALL
RATES OF 0.2-0.4"/HR ACROSS SRN CHITTENDEN AND ADDISON COUNTIES
WITH THE MOST INTENSE ACTIVITY. FLASH FLOOD GUIDANCE SUGGESTS
2-3"/6-HR WILL BE NEEDED FOR ANY SIGNIFICANT FLOOD THREAT...SO
GIVEN RAIN RATES IT WILL DEPEND ON PERSISTENCE/STATIONARITY OF
INDIVIDUAL SHOWERS OVER THE NEXT SEVERAL HOURS.
VAD WIND PROFILES AND NAM FORECAST SOUNDINGS INDICATE SFC- 250MB
FLOW BELOW 10 KTS AT ALL LEVELS...WHICH CERTAINLY WILL SUPPORT
SLOW MOVING SHOWERS. CONTINUED WITH HEAVY RAIN WORDING FOR
CENTRAL/S-CENTRAL VT THIS AFTERNOON AND EVENING. THE ONLY
MITIGATING FACTOR IS THAT PW VALUES ARE ONLY AROUND 0.75"...AFTER
BEING 1.1-1.2" YESTERDAY. WE/LL CONTINUE TO MONITOR SHORT-TERM
TRENDS FOR ANY LOCALIZED FLOODING CONCERNS...WHICH WILL BE
CENTERED ON ADDISON AND RUTLAND COUNTIES.
WITH LOW OVERCAST IN PLACE...TEMPERATURES WILL NOT RISE
SIGNIFICANTLY THIS AFTN AND HIGH TEMP FORECAST IS A FEW DEGREES
BELOW THE MOS CONSENSUS. LOOKING FOR READINGS 62-64F IN THE
CHAMPLAIN VALLEY...65-69F IN THE ST. LAWRENCE VALLEY WITH A BIT
MORE SUNSHINE...WHILE HOLDING IN THE UPR 50S FOR THE NRN ADIRONDACKS AND
MOST SECTIONS EAST OF THE GREEN MTN SPINE.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SUNDAY/...
AS OF 515 AM EDT FRIDAY...UPPER LEVEL TROF FINALLY SHIFTS
SOUTHEAST OF THE NORTH COUNTRY OVERNIGHT AND COVERAGE OF SHOWERS
WILL DECREASE OVERNIGHT. SOME SHOWERS MAY AGAIN LINGER THROUGH
THE OVERNIGHT THOUGH...SIMILAR TO THE LAST COUPLE NIGHTS.
SOUTHERN AND EASTERN VERMONT WILL HAVE THE BEST CHANCE FOR THIS.
SKIES REMAIN CLOUDY AND TEMPERATURES WILL BE MILD. DURING THE
DAYTIME HOURS ON SATURDAY NORTHWESTERLY MID LEVEL FLOW DEVELOPS.
THERE SHOULD BE SOME SUN WITH DRIER AIR MOVING INTO THE REGION.
THIS WILL CAUSE SOME INSTABILITY...THOUGH MINOR...AND SOME
AFTERNOON SHOWERS AND ISOLATED THUNDERSTORMS ARE ONCE AGAIN
EXPECTED. DUE TO SOME SUN IN THE FORECAST...AFTERNOON MAX TEMPS
WILL BE CLOSER TO SEASONAL NORMALS ON SATURDAY. SURFACE WINDS
WILL ALSO BE A BIT STRONGER WITH GRADIENT FLOW SUPPORTING NW
WINDS AROUND 10 MPH THROUGH THE DAYTIME HOURS. DAYTIME SHOWERS
AND THUNDERSTORMS WILL DISSIPATE OVERNIGHT AND FLOW WEAKENS AS
WELL. PARTLY CLOUDY SKIES WILL BE IN PLACE...AND RESULTING IN MIN
TEMPERATURES NEAR SEASONAL NORMALS. SURFACE HIGH BEGINS TO RIDGE
INTO THE NORTH COUNTRY ON SUNDAY...THOUGH NORTHWESTERLY UPPER
LEVEL FLOW WILL CONTINUE. WEAK UPPER LEVEL DISTURBANCES PASSING
THROUGH PROGRESSIVE FLOW WILL ONCE AGAIN BRING POSSIBILITY OF
SOME AFTERNOON SHOWERS...HAVE CHANCE POPS MENTIONED AT THIS TIME.
TEMPERATURES WILL BE SLIGHTLY WARMER THAN SEASONAL NORMALS WITH
SUN HELPING TO WARM THE AREA.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 345 AM EDT FRIDAY...THE MAIN SURFACE WEATHER FEATURES WILL
BE A WARM FRONT MOVING IN SUNDAY NIGHT PASSING EARLY MONDAY AND A
COLD FRONT PASSING EARLY TUESDAY...BOTH WITH CHANCES OF SHOWERS
FOLLOWED BY MAINLY DRY WEATHER WED AND THU. THROUGH THE PERIOD
EXPECT CLOSE TO AVERAGE TEMPS FOR THIS TIME OF YEAR THOUGH IT
MIGHT BE A BIT COOLER ON WED.
THE UPPER LEVEL PATTERN FOR THE PERIOD WILL BE A PERSISTENT
NORTHWEST TO NORTH FLOW OVER OUR AREA WITH A COLD TROF/CUTOFF LOW
DEVELOPING IN THE CANADIAN MARITIMES AND HEAT RIDGE IN THE CENTER
OF THE COUNTRY.
CONFIDENCE RISING IN THE FORECAST AS MODELS ARE COMING INTO
BETTER AGREEMENT WITH THE EVOLUTION OF THE TROF/CUTOFF LOW IN THE
MARITIMES WITH THE ECMWF COMING BETTER IN LINE WITH THE GFS.
SUNDAY NIGHT A DEVELOPING WARM FRONT WILL BRING A CHANCE OF
SHOWERS WITH TEMPS IN THE 50S.
MONDAY AFTER SOME MORNING SHOWERS THE AREA GETS MORE INTO THE
WARM SECTOR WITH 85O TEMPS REACHING AS HIGH AS +10 TO +12C, SO
HIGH TEMPS WELL INTO THE 70S, PERHAPS NEAR 80. COULD BE A ROGUE
THUNDERSTORM BUT INSTABILITY LOOKS WEAK AT THIS POINT.
TUESDAY 850 TEMPS DROPPING WITH ABOUT +8C GIVING TEMPS IN THE
LOWER 70S WITH A CHANCE OF SHOWERS AS A COLD FRONT DROPS
SOUTHWARD THROUGH THE AREA.
WED...850 TEMPS DOWN NEAR 0C EARLY RECOVER UP TO ABOUT 5-7C SO
TEMPS WILL BE IN THE 60S TO AROUND 70 UNDER A COOL NORTHERLY FLOW
WITH LOTS OF FAIR WEATHER CUMULUS. ONLY EXCEPTION WILL BE CHANCE
OF A SHOWER ESPECIALLY IN THE NORTHEAST. LOW TEMPS DOWN IN THE
40S, PERHAPS INTO THE 30S IN THE COLD SPOTS.
THU...850 TEMPS BACK UP TO 8-10C WITH TEMPS IN THE 70S AGAIN WITH
A DRY NORTHERLY FLOW.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 12Z SATURDAY...MVFR/IFR WITH LIGHT SHOWERS OR DRIZZLE...LOW
CLOUDS...PATCHY FOG AND MIST WITH 0-3 DEGREE DEW POINT DEPRESSIONS
THROUGH MID MORNING WITH WEAK LOW PRESSURE RIGHT OVER THE AREA.
CEILINGS WILL SLOWLY LIFT DURING THE DAY TO MVFR OR JUST BARELY
VFR BY AFTERNOON DUE TO DAYTIME HEATING. CAN`T COMPLETELY RULE
OUT A THUNDERSTORM DEPENDING ON HOW MUCH HEATING TAKES PLACE, BUT
INSTABILITY IS MINIMAL WITH THE BEST CHANCE OF THUNDER AT KMSS
WITH A BIT MORE HEATING.
WINDS WILL BE LIGHT AND VARIABLE EXCEPT PERHAPS A TREND TO LIGHT
NORTHERLY IN THE CHAMPLAIN VALLEY AT KBTV/KPBG AND AT KMSS WHERE
IT WILL BE PERSISTENT NE AROUND 10 KTS.
OUTLOOK 06Z SATURDAY THROUGH TUESDAY...
12Z SAT THRU 00Z MON...MVFR/IFR EARLY BECOMING MAINLY VFR WITH
SCATTERED MVFR SHOWERS SATURDAY AFTERNOON...AND ISOLATED SHOWERS
SUNDAY AFTERNOON.
00Z MON THRU 00Z TUE...GENERALLY DRY WITH VFR CONDITIONS UNDER
SFC HIGH PRESSURE.
00Z TUE ONWARD...VFR WITH SCATTERED MVFR SHOWERS/POSSIBLE
THUNDERSTORMS ASSOCIATED WITH PASSING COLD FRONT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...BANACOS
SHORT TERM...NEILES
LONG TERM...SISSON
AVIATION...SISSON
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
110 PM CDT FRI MAY 23 2014
.UPDATE...
ISSUED AT 110 PM CDT FRI MAY 23 2014
17 UTC TEMPERATURES RUNNING A FEW DEGREES WARMER THAN PREVIOUSLY
FORECAST...ESPECIALLY ALONG THE VALLEY FLOOR. AS A RESULT...
INCREASED AFTERNOON HIGHS TO NEAR 80 DEGREES OR SLIGHTLY HIGHER
ALONG AND WEST OF THE VALLEY. BAND OF ALTOCU HAS DEVELOPED ALONG A
LINE FROM NEW ROCKFORD TO SOUTH OF WAHPETON...BUT NO ECHOES ON
RADAR YET. WILL KEEP 20 POPS THROUGH THE AFTERNOON...ALTHOUGH AREAL
COVERAGE OF ANY ACTIVITY SHOULD BE VERY LIMITED.
UPDATE ISSUED AT 1025 AM CDT FRI MAY 23 2014
ISOLATED CLUSTER OF SHOWERS AND THUNDERSTORMS ALONG THE ND/SD
BORDER HAS DISSIPATED AND/OR MOVED INTO NORTHEAST SD. LATEST RAP
AND TO A LESSER EXTENT THE HRRR SHOWS SOME RE-DEVELOPMENT OF SOME
ISOLATED CONVECTION THIS AFTERNOON ACROSS SOUTHEAST ND ALONG LOW-
LEVEL CAPE GRADIENT WITH INSTABILITY INCREASING UP TO 1500 J/KG.
OVERALL FORCING IS WEAK...BUT THERE IS A SHORT WAVE RIDING THE
RIDGE THROUGH NORTH CENTRAL ND THAT COULD PRODUCE SOME LIFT FOR
ADDITIONAL AFTERNOON CONVECTION. ADDED 20 POPS ACROSS SOUTHEAST ND
THIS AFTERNOON FOR THIS POTENTIAL. OTHERWISE...UPDATED HOURLY
TEMPERATURES/SKY COVER/WINDS TO MATCH LATEST OBSERVATIONS. REST OF
FORECAST IN GOOD SHAPE WITH NO MAJOR ADJUSTMENTS NEEDED.
UPDATE ISSUED AT 641 AM CDT FRI MAY 23 2014
WEAK ISOLATED ELEVATED CONVECTION HAVING A TOUGH TIME WORKING EAST
INTO THE FORECAST AREA EARLY THIS MORNING. ANY STORMS WHICH
PROPAGATE EAST WILL MEET WITH AN INCREASINGLY DRY AND STABLE
AIRMASS. SLOWED UP EASTWARD PROGRESS WITH POPS OTHERWISE FORECAST
OK.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 312 AM CDT FRI MAY 23 2014
SHORT TERM CHALLENGES WILL BE LOW END COVERAGE PCPN CHANCES AND
TEMPERATURES. MODELS OVERALL IN FAIR AGREEMENT AND WILL USE
PERSISTENCE AND MODEL BLEND FOR FORECAST.
IN THE NEAR TERM WILL BE MONITORING ELEVATED CONVECTION ACROSS
THE CENTRAL DAKOTAS ASSOCIATED WITH WARM ADVECTION AND MODEST
850MB SPEED CONVERGENCE. MOST MODELS PICKING UP ON THIS
DEVELOPMENT HOWEVER HOW FAR EAST CONVECTION CAN GET IN QUESTION.
SURFACE HIGH PRESSURE TO REMAIN OVER MN/WESTERN GREAT LAKES AND
ASSOCIATED AIRMASS PRETTY DRY AND STABLE SO WOULD EXPECT ANY
CONVECTION TO WEAKEN AS IT PROPAGATES FARTHER EAST INTO THE FA.
WILL MAINTAIN SOME LOW END CHANCES ACROSS THE SW FORECAST AREA FOR
NOW AND ADJUST IF NEEDED. OTHERWISE MID LEVEL RIDGE TO BUILD
ACROSS THE N CENTRAL US WITH THE RIDGE AXIS OVER THE FA THROUGH
FRIDAY. STEADY WARM ADVECTION TODAY WITH SOUTH BREEZES AND WHILE
SOME CLOUD COVER FROM CONVECTIVE DEBRIS MAY BE AROUND THIS MORNING
OVERALL SHOULD SEE TEMPERATURES CLIMB WELL ABOVE AVERAGE.
SOME INSTABILITY AND CAPE WORK INTO THE WESTERN FA THIS AFTERNOON
INTO TONIGHT ALONG WITH PRECIPITABLE H2O VALUES INCREASING TO AN
INCH OR BETTER. MID LEVEL SUPPORT/SHEAR LOOKS WEAK AND NOT REALLY
SEEING MUCH FOR ANY LOW LEVEL CONVERGENCE OTHER THAN SOME WEAK
SPEED CONVERGENCE AROUND 850MB. ANY PCPN WHICH DEVELOPS TO
PROPAGATE NE SO WILL MAINTAIN CURRENT LOW END POPS. COLUMN WARM
AND WITH SOME MIXING HOLDING UP OVERNIGHT WILL BE A MILD NIGHT.
BRUNT OF SATURDAY SHOULD BE DRY. COULD SEE SOME RESIDUAL
CONVECTION SATURDAY MORNING ACROSS THE NORTH HOWEVER CONFIDENCE
NOT HIGH ENOUGH TO WARRANT POPS. BY MID/LATE AFTERNOON AIRMASS
AGAIN DESTABILIZES HOWEVER WITH LACK OF FORCING AND LOW LEVEL
CONVERGENCE NOT A GREAT DEAL OF CONFIDENCE WITH CONVECTION
POTENTIAL/COVERAGE.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 312 AM CDT FRI MAY 23 2014
SURFACE FRONTAL BOUNDARY CROSSES WESTERN DAKOTAS SATURDAY NIGHT.
ALONG AND AHEAD OF BOUNDARY SEEMS BEST POTENTIAL FOR CONVECTION
AND WILL MAINTAIN HIGHER POPS ACROSS THE WESTERN FA.
FRONT CROSSES FA SUNDAY/SUNDAY EVENING AND THESE PERIODS LOOK LIKE
THE BEST POTENTIAL FOR CONVECTION DURING THE HOLIDAY WEEKEND.
WILL BROAD BRUSH FA WITH LIKELY POPS AS MODELS HAVING SOME
DIFFERENCES WITH TIMING OF FROPA. BASED ON CONVECTIVE PARAMETERS
SEVERE THREAT LOOKS MARGINAL. THERMAL RIDGE AXIS WILL BE OVER FA
HOWEVER CLOUDS WILL LIKELY TEMPER MAXIMUM TEMPERATURES.
MEMORIAL DAY LOOKS DRY BUT BREEZY AND COOLER AS HIGH PRESSURE
BUILDS INTO THE FA.
MONDAY-THURSDAY...A CONTINUED WARM PATTERN IS EXPECTED THROUGH THE
PERIOD. THE 00Z GFS/ECMWF INDICATE MID/UPPER RIDGING WILL RE-ASSERT
ITSELF DURING THE MID-WEEK TIME FRAME OVER THE CENTRAL CONUS
FOLLOWING THE PASSAGE OF THE EARLY WEEK SHORTWAVE SUNDAY INTO
MONDAY...WITH UPPER TROUGHING DEVELOPING ACROSS THE PAC NORTHWEST.
THUS...AFTER PERHAPS SLIGHTLY COOLER TEMPS ON MONDAY...HIGHS SHOULD
BE WELL INTO THE 70S...IF NOT 80S FOR MID-WEEK. IF THIS RELATIVELY
AMPLIFIED PATTERN VERIFIES...LARGE SCALE FORCING WOULD BE WEAK
THROUGH MOST OF THE PERIOD WITH THE STRONGER WESTERLIES TO THE NORTH
AND WEST...WHERE THE BETTER PRECIP CHANCES WOULD BE. ANY WEAKER
DISTURBANCES AND ASSOCIATED FOCUSED LOW-LEVEL WARM ADVECTION COULD
LEAD TO POCKETS OF CONVECTION. WITH THE UNCERTAINTY OF THE
ORIENTATION/AMPLIFICATION OF THE LONG WAVE PATTERN AND EMBEDDED
IMPULSES...WILL KEEP SOME SLIGHT/CHANCE POPS TUE-THU OVER PORTIONS
OF THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 110 PM CDT FRI MAY 23 2014
MAIN AVIATION CHALLENGE FOR THIS EVENING WILL BE A CHANCE FOR SOME
EARLY EVENING CONVECTION OVER EASTERN ND. MODELS ARE SHOWING SOME
WEAK INSTABILITY MAINLY OVER THE DVL AREA..EXTENDING EASTWARD TOWARD
GFK AROUND 01Z. WILL PUT IN VCTS FOR BOTH SITES AND FAR FROM AROUND
00Z TO 06Z...WITH MOST CONFIDENCE AT DVL. ANY ACTION WILL BE SHORT
LIVED AND DISSIPATE BY MIDNIGHT. CLEAR SKIES EXPECTED OVER NW AND W
CNTRL MN TONIGHT. SOUTHERLY WINDS WILL CONTINUE THROUGHOUT NEXT 24
HOURS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...ROGERS
SHORT TERM...VOELKER
LONG TERM...MAKOWSKI/VOELKER
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
427 PM EDT FRI MAY 23 2014
.SYNOPSIS...
A WEAK COLD FRONT WILL STALL OUT OVER GEORGIA TONIGHT. SURFACE HIGH
PRESSURE WILL THEN DRIFT EASTWARD FROM THE OHIO VALLEY TO THE
OFFSHORE ATLANTIC WATERS OVER THE WEEKEND. THE REGION IS EXPECTED TO
BE BACK UNDER THE INFLUENCE OF THE BERMUDA HIGH BY EARLY NEXT WEEK
WITH DEWPOINTS AND TEMPERATURES WARMING.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 425 PM EDT FRIDAY...SCATTERED CONVECTION WILL CONTINUE ACROSS
PORTIONS OF THE UPSTATE THROUGH THE REMAINDER OF THE AFTERNOON. THE
ATM REMAINS UNSTABLE ALONG AND SOUTH OF INTERSTATE 85 WITH A
PLUME OF SBCAPE IN EXCESS 2500 JOULES ACROSS THE WESTERN UPSTATE AND
PORTIONS OF NORTHEAST GA...PER 20Z MESOANALYSIS. WOULD NOT BE
SURPRISED TO SEE FURTHER INITIATION TO THE WEST ACROSS AREAS THAT
HAVE NOT BEEN WORKED OVER BY PAST/PRESENT CONVECTION...SPECIFICALLY
WEST OF I26 IN SC/GA WHERE CU FIELD REMAINS PREVALENT.
THUS...INCREASED POPS DRASTICALLY ACROSS THE UPSTATE TO ACCOUNT FOR
CONTINUED DEVELOPMENT THROUGH EARLY EVENING. HAIL REMAINS THE
PRIMARY THREAT WITH ANY DEEPER CONVECTION AS MULTIPLE REPORTS OF
QUARTER TO TENNIS BALL SIZED HAIL HAVE BEEN RECEIVED. NO CHANGES
PLANNED TO WATCH BOX AT THIS TIME.
PREVIOUS DISCUSSION...
AS OF 230 PM EDT...CONVECTION REMAINS LARGELY BENIGN ATTM WITH
MAINLY SCT CU OVER SOME OF THE MTNS AND WRN UPSTATE. UNDER STILL
BRISK MID-UPPER LEVEL NW FLOW...MTN WAVE CIRRUS CONTINUE TO KEEP
MCLDY SKIES OVER THE NC FOOTHILLS AND NW PIEDMONT. THESE AREAS WERE
HIT PRETTY HARD WITH OUTFLOW FROM THE TSTM CLUSTER THIS MORNING AND
APPEAR TO HAVE BEEN KEPT STABLE BY THIS AND TO SOME EXTENT THE
CIRRUS. S AND W OF THIS AREA ISOLATED TSRA ARE STILL
EXPECTED...WHERE 1500-2000 J OF UNCAPPED SBCAPE IS SHOWN ON SPC
MESOANALYSIS. INDEED A COUPLE OF CELLS ARE STARTING TO GO UP OVER
PICKENS COUNTY. THE 12Z NCEP HIRES WINDOW RUNS REINFORCE SUGGESTIONS
OF NUMEROUS HRRR AND RAP RUNS THAT ISOLD ACTIVITY WILL KICK OFF IN
THE SMOKIES AND IN THE UPSTATE EAST OF SPARTANBURG. WITH THE
AFOREMENTIONED INSTABILITY AND EFFECTIVE BULK SHEAR OF 35-45
KT...ALONG WITH SUBSTANTIAL DCAPE OVER 1000 J/KG...STORMS WILL BE
QUITE CAPABLE OF DMGG WIND/HAIL. SVR WATCH JUST ISSUED FOR THE SRN
TIER OF THE NC MTNS/FOOTHILLS...THE UPSTATE AND NE GA.
HIGH PRESSURE BEGINS TO BUILD ACRS THE GREAT LAKES AND OHIO VALLEY
THRU TONIGHT. COLD FRONT CONTINUES TO BE PROGGED TO PUSH SWD THRU
MOST OF THE NC MTNS AND PIEDMONT BY DAYBREAK...PUSHING THROUGH THE
ERN SC PIEDMONT THEREAFTER. IN THE WAKE OF THE FRONT THINGS REMAIN
STABLE THROUGH THE DAY. HOWEVER...WITH A FAIRLY FLAT UPPER RIDGE
REMAINING OVER THE GULF STATES...THE FRONT DOES NOT APPEAR TO FULLY
IMPACT THE SAVANNAH RIVER VALLEY AND WRN UPSTATE. HOWEVER SUBSIDENCE
ALOFT APPEARS TO BE ENOUGH TO WEAKEN LAPSE RATES TO THE POINT THAT
ONLY LIMITED CONVECTION WILL BE POSSIBLE IN THIS AREA. GFS AND NAM
CONTINUE TO PRODUCE HEFTY SBCAPE VALUES OVER 1000 J/KG WEST OF
GSP...BUT SREF PROBS SUGGEST VALUES MOST LIKELY WILL NOT GET THIS
HIGH. I WILL INCLUDE A SCHC FOR DIURNAL SHWRS/TSTMS ALONG THE SRN
ESCARPMENT AND AREAS JUST SOUTH WHERE THE BEST INSTABILITY IS
SUGGESTED. HIGHS WILL BE NEAR NORMAL IN THE MORE CONTINENTAL AIRMASS
BUT WITH BRIGHT SUNSHINE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM FRIDAY...ONLY SUBTLE CHANGES ARE EXPECTED TO THE
OVERALL UPPER PATTERN FROM SUNDAY INTO MONDAY...MEANING WE SHOULD
REMAIN UNDER A NW FLOW ALOFT BUT THAT HEIGHTS SHOULD RISE A BIT AS
THE TROF OFF THE EAST COAST DEAMPLIFIES. THIS PATTERN WILL ALLOW THE
CENTER OF SURFACE HIGH PRESSURE TO MIGRATE FROM THE MIDWEST/OH
VALLEY REGION TO A POSITION OFF THE SOUTHEAST COAST ON SUNDAY. ONCE
THIS HAPPENS...WE CAN EXPECT SOME RETURN OF MOISTURE FROM THE SOUTH
AND SOME WEAK WARM ADVECTION. THAT WILL PUT THE WESTERN CAROLINAS
AND NE GEORGIA BACK INTO A REGIME WHERE MAINLY DIURNAL SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE. PRECIP CHANCES WERE LIMITED TO A
SLIGHT CHANCE ACROSS MOST OF THE AREA SUNDAY OWING TO THE LACK OF
DEVELOPMENT SEEN IN THE NAM...BUT THEN WERE ALLOWED TO GO UP TO A
CHANCE ACROSS MOST OF THE REGION MONDAY AS MOISTURE AND INSTABILITY
WERE INCREMENTALLY BETTER. TEMPS WILL CREEP UP A BIT FOR SUNDAY...
AND THEN RISE ABOUT A CATEGORY HIGHER FOR MONDAY...AROUND 80 IN THE
MTN VALLEYS AND MIDDLE 80S E OF THE MTNS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 145 PM FRIDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON
TUESDAY WITH THE PERSISTENT UPPER RIDGE ANCHORED OVER THE CENTRAL
CONUS AND AN EMBEDDED H5 LOW DRIFTING SLOWLY EASTWARD OVER THE
SOUTHERN PLAINS. SIMULTANEOUSLY...A CLOSED UPPER LOW IS EXPECTED TO
DROP DOWN OVER EXTREME NORTHERN NEW ENGLAND AND REMAIN OVER THAT
REGION FOR MOST OF THE PERIOD. IN TERMS OF THE SYNOPTIC PATTERN
EVOLUTION OVER OUR REGION...WE DONT EXPECT ANY SIG CHANGES THRU DAY
7 WITH THE DOMINANT UPPER RIDGE REMAINING IN PLACE THRU THE PERIOD.
AT THE SFC...WE BEGIN THE PERIOD UNDER LIGHT SLY FLOW WITH A TYPICAL
BERMUDA HIGH IN PLACE TO OUR EAST. EARLY IN THE DAY...A FAIRLY
ROBUST LOW DEEPENS OVER EXTREME NORTHERN NEW ENGLAND AND BRINGS A
SWATH OF COOLER AND DRIER AIR TOWARDS THE FCST AREA. THE MODELS
DIFFER ON HOW FAR SOUTH THIS LOW WILL MAKE WITH THE GFS BRINGING IT
QUITE A BIT FARTHER SOUTH THAN THE ECMWF AND CMC MODELS. I WILL
CONTINUE TO PUT MORE EMPHASIS ON THE ECMWF AND CMC SOLUTIONS FOR THE
TIME BEING AND THUS I DONT EXPECT THE COOLER/DRIER AIR TO PENETRATE
AS FAR SOUTH AS THE GFS SUGGESTS. ONCE THIS LOW MOVES WELL
OFFSHORE...ANOTHER CANADIAN HIGH TRIES TO PUSH SOUTHWARD AND INTO
THE REGION...HOWEVER ITS LOOKING LIKE IT WILL DISSIPATE FAIRLY QUICKLY
ONCE IT MAKES TO THE CAROLINAS.
AT ANY RATE...NO MAJOR CHANGES WERE NEEDED TO THE SENSIBLE FCST. I
DID INCREASE POPS OVER SOME PORTIONS OF THE CWFA TO SOLID CHANCE FOR
WIDELY SCT DIURNAL SHOWERS AND TS FOR WED AND THURS. OTHERWISE...I
CARRY A SLIGHT TO SOLID CHANCE FOR SH AND TS EACH DAY OF THE PERIOD.
IN ADDITION...IT IS TOO EARLY TO MENTION ANY THREAT OF SVR OR WELL
ORGANIZED CONVECTION AT THIS POINT. TEMPS SHOULD START OUT 5 TO 10
DEGREES ABOVE NORMAL FOR LATE MAY AND GRADUALLY DROP THRU THE PERIOD
WITH HIGHS RIGHT AROUND NORMAL BY NEXT FRIDAY.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...FOLLOWING THE CONVECTION WHICH MOVED THRU THIS MORNING AND
LEFT BEHIND COOLER AND MORE STABLE AIR...THREAT OF TSRA THIS AFTN
APPEARS TO HAVE BEEN MITIGATED TO THE POINT THAT A TEMPO IS NO
LONGER WARRANTED. HOWEVER...THERE IS STILL A VERY SMALL CHANCE A
STORM COULD AFFECT THE FIELD WITH GUSTY WINDS AND POSSIBLY HAIL. A
FEW LOW VFR CU ARE LIKELY TO PERSIST AT ANY RATE. GENERALLY NW WINDS
WILL PRECEDE OVERNIGHT ARRIVAL OF BACKDOOR COLD FRONT...WHICH SHOULD
BRING WINDS N TO NNE AND VIRTUALLY CLEAR SKIES. PROFILES LOOK
UNFAVORABLE FOR FOG WITH LLVL DRYING IN THE WAKE OF THE FRONT.
ELSEWHERE...ISOLD SHRA/TSRA ARE EXPECTED THIS AFTN IN THE MTNS OF SW
NC...SC AND GA...AS WELL AS IN THE AREA GENERALLY SOUTH OF I-85. THE
TSRA WILL BE CAPABLE OF VERY GUSTY WINDS AND HAIL. THIS ACTIVITY
WILL BE DIURNALLY DRIVEN AND SHOULD NOT PERSIST INTO THE EVENING.
WINDS GO NORTHERLY OVERNIGHT AS COLD FRONT PUSHES IN. SHOULD REMAIN
TOO DRY FOR FOG EXCEPT PERHAPS IN MTN VALLEYS. THE FRONT MAY HANG UP
OVER THE SAVANNAH RIVER VALLEY AND CAUSE WINDS TO RETURN TO SW AFTER
DAYBREAK AT KAND/KGMU/KGSP. CONFIDENCE ON THIS IS LOW SO NO MENTION
WAS MADE IN THE TAF.
OUTLOOK...DRY HIGH PRESSURE BUILDS IN SATURDAY. VERY ISOLATED
SHRA/TSRA ARE POSSIBLE SAT/SUN AFTNS. AFTN CONVECTION COVERAGE IS
EXPECTED TO INCREASE SOMEWHAT FOR MONDAY AND TUESDAY...AS DEEPER
MOISTURE RETURNS.
CONFIDENCE TABLE...
20-02Z 02-08Z 08-14Z 14-20Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...CDG/WIMBERLEY
SHORT TERM...PM
LONG TERM...JPT
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
257 PM EDT FRI MAY 23 2014
.SYNOPSIS...
A WEAK COLD FRONT WILL STALL OUT OVER GEORGIA TONIGHT. SURFACE HIGH
PRESSURE WILL THEN DRIFT EASTWARD FROM THE OHIO VALLEY TO THE
OFFSHORE ATLANTIC WATERS OVER THE WEEKEND. THE REGION IS EXPECTED TO
BE BACK UNDER THE INFLUENCE OF THE BERMUDA HIGH BY EARLY NEXT WEEK
WITH DEWPOINTS AND TEMPERATURES WARMING.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 230 PM EDT...CONVECTION REMAINS LARGELY BENIGN ATTM WITH
MAINLY SCT CU OVER SOME OF THE MTNS AND WRN UPSTATE. UNDER STILL
BRISK MID-UPPER LEVEL NW FLOW...MTN WAVE CIRRUS CONTINUE TO KEEP
MCLDY SKIES OVER THE NC FOOTHILLS AND NW PIEDMONT. THESE AREAS WERE
HIT PRETTY HARD WITH OUTFLOW FROM THE TSTM CLUSTER THIS MORNING AND
APPEAR TO HAVE BEEN KEPT STABLE BY THIS AND TO SOME EXTENT THE
CIRRUS. S AND W OF THIS AREA ISOLATED TSRA ARE STILL
EXPECTED...WHERE 1500-2000 J OF UNCAPPED SBCAPE IS SHOWN ON SPC
MESOANALYSIS. INDEED A COUPLE OF CELLS ARE STARTING TO GO UP OVER
PICKENS COUNTY. THE 12Z NCEP HIRES WINDOW RUNS REINFORCE SUGGESTIONS
OF NUMEROUS HRRR AND RAP RUNS THAT ISOLD ACTIVITY WILL KICK OFF IN
THE SMOKIES AND IN THE UPSTATE EAST OF SPARTANBURG. WITH THE
AFOREMENTIONED INSTABILITY AND EFFECTIVE BULK SHEAR OF 35-45
KT...ALONG WITH SUBSTANTIAL DCAPE OVER 1000 J/KG...STORMS WILL BE
QUITE CAPABLE OF DMGG WIND/HAIL. SVR WATCH JUST ISSUED FOR THE SRN
TIER OF THE NC MTNS/FOOTHILLS...THE UPSTATE AND NE GA.
HIGH PRESSURE BEGINS TO BUILD ACRS THE GREAT LAKES AND OHIO VALLEY
THRU TONIGHT. COLD FRONT CONTINUES TO BE PROGGED TO PUSH SWD THRU
MOST OF THE NC MTNS AND PIEDMONT BY DAYBREAK...PUSHING THROUGH THE
ERN SC PIEDMONT THEREAFTER. IN THE WAKE OF THE FRONT THINGS REMAIN
STABLE THROUGH THE DAY. HOWEVER...WITH A FAIRLY FLAT UPPER RIDGE
REMAINING OVER THE GULF STATES...THE FRONT DOES NOT APPEAR TO FULLY
IMPACT THE SAVANNAH RIVER VALLEY AND WRN UPSTATE. HOWEVER SUBSIDENCE
ALOFT APPEARS TO BE ENOUGH TO WEAKEN LAPSE RATES TO THE POINT THAT
ONLY LIMITED CONVECTION WILL BE POSSIBLE IN THIS AREA. GFS AND NAM
CONTINUE TO PRODUCE HEFTY SBCAPE VALUES OVER 1000 J/KG WEST OF
GSP...BUT SREF PROBS SUGGEST VALUES MOST LIKELY WILL NOT GET THIS
HIGH. I WILL INCLUDE A SCHC FOR DIURNAL SHWRS/TSTMS ALONG THE SRN
ESCARPMENT AND AREAS JUST SOUTH WHERE THE BEST INSTABILITY IS
SUGGESTED. HIGHS WILL BE NEAR NORMAL IN THE MORE CONTINENTAL AIRMASS
BUT WITH BRIGHT SUNSHINE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM FRIDAY...ONLY SUBTLE CHANGES ARE EXPECTED TO THE
OVERALL UPPER PATTERN FROM SUNDAY INTO MONDAY...MEANING WE SHOULD
REMAIN UNDER A NW FLOW ALOFT BUT THAT HEIGHTS SHOULD RISE A BIT AS
THE TROF OFF THE EAST COAST DEAMPLIFIES. THIS PATTERN WILL ALLOW THE
CENTER OF SURFACE HIGH PRESSURE TO MIGRATE FROM THE MIDWEST/OH
VALLEY REGION TO A POSITION OFF THE SOUTHEAST COAST ON SUNDAY. ONCE
THIS HAPPENS...WE CAN EXPECT SOME RETURN OF MOISTURE FROM THE SOUTH
AND SOME WEAK WARM ADVECTION. THAT WILL PUT THE WESTERN CAROLINAS
AND NE GEORGIA BACK INTO A REGIME WHERE MAINLY DIURNAL SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE. PRECIP CHANCES WERE LIMITED TO A
SLIGHT CHANCE ACROSS MOST OF THE AREA SUNDAY OWING TO THE LACK OF
DEVELOPMENT SEEN IN THE NAM...BUT THEN WERE ALLOWED TO GO UP TO A
CHANCE ACROSS MOST OF THE REGION MONDAY AS MOISTURE AND INSTABILITY
WERE INCREMENTALLY BETTER. TEMPS WILL CREEP UP A BIT FOR SUNDAY...
AND THEN RISE ABOUT A CATEGORY HIGHER FOR MONDAY...AROUND 80 IN THE
MTN VALLEYS AND MIDDLE 80S E OF THE MTNS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 145 PM FRIDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON
TUESDAY WITH THE PERSISTENT UPPER RIDGE ANCHORED OVER THE CENTRAL
CONUS AND AN EMBEDDED H5 LOW DRIFTING SLOWLY EASTWARD OVER THE
SOUTHERN PLAINS. SIMULTANEOUSLY...A CLOSED UPPER LOW IS EXPECTED TO
DROP DOWN OVER EXTREME NORTHERN NEW ENGLAND AND REMAIN OVER THAT
REGION FOR MOST OF THE PERIOD. IN TERMS OF THE SYNOPTIC PATTERN
EVOLUTION OVER OUR REGION...WE DONT EXPECT ANY SIG CHANGES THRU DAY
7 WITH THE DOMINANT UPPER RIDGE REMAINING IN PLACE THRU THE PERIOD.
AT THE SFC...WE BEGIN THE PERIOD UNDER LIGHT SLY FLOW WITH A TYPICAL
BERMUDA HIGH IN PLACE TO OUR EAST. EARLY IN THE DAY...A FAIRLY
ROBUST LOW DEEPENS OVER EXTREME NORTHERN NEW ENGLAND AND BRINGS A
SWATH OF COOLER AND DRIER AIR TOWARDS THE FCST AREA. THE MODELS
DIFFER ON HOW FAR SOUTH THIS LOW WILL MAKE WITH THE GFS BRINGING IT
QUITE A BIT FARTHER SOUTH THAN THE ECMWF AND CMC MODELS. I WILL
CONTINUE TO PUT MORE EMPHASIS ON THE ECMWF AND CMC SOLUTIONS FOR THE
TIME BEING AND THUS I DONT EXPECT THE COOLER/DRIER AIR TO PENETRATE
AS FAR SOUTH AS THE GFS SUGGESTS. ONCE THIS LOW MOVES WELL
OFFSHORE...ANOTHER CANADIAN HIGH TRIES TO PUSH SOUTHWARD AND INTO
THE REGION...HOWEVER ITS LOOKING LIKE IT WILL DISSIPATE FAIRLY QUICKLY
ONCE IT MAKES TO THE CAROLINAS.
AT ANY RATE...NO MAJOR CHANGES WERE NEEDED TO THE SENSIBLE FCST. I
DID INCREASE POPS OVER SOME PORTIONS OF THE CWFA TO SOLID CHANCE FOR
WIDELY SCT DIURNAL SHOWERS AND TS FOR WED AND THURS. OTHERWISE...I
CARRY A SLIGHT TO SOLID CHANCE FOR SH AND TS EACH DAY OF THE PERIOD.
IN ADDITION...IT IS TOO EARLY TO MENTION ANY THREAT OF SVR OR WELL
ORGANIZED CONVECTION AT THIS POINT. TEMPS SHOULD START OUT 5 TO 10
DEGREES ABOVE NORMAL FOR LATE MAY AND GRADUALLY DROP THRU THE PERIOD
WITH HIGHS RIGHT AROUND NORMAL BY NEXT FRIDAY.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...FOLLOWING THE CONVECTION WHICH MOVED THRU THIS MORNING AND
LEFT BEHIND COOLER AND MORE STABLE AIR...THREAT OF TSRA THIS AFTN
APPEARS TO HAVE BEEN MITIGATED TO THE POINT THAT A TEMPO IS NO
LONGER WARRANTED. HOWEVER...THERE IS STILL A VERY SMALL CHANCE A
STORM COULD AFFECT THE FIELD WITH GUSTY WINDS AND POSSIBLY HAIL. A
FEW LOW VFR CU ARE LIKELY TO PERSIST AT ANY RATE. GENERALLY NW WINDS
WILL PRECEDE OVERNIGHT ARRIVAL OF BACKDOOR COLD FRONT...WHICH SHOULD
BRING WINDS N TO NNE AND VIRTUALLY CLEAR SKIES. PROFILES LOOK
UNFAVORABLE FOR FOG WITH LLVL DRYING IN THE WAKE OF THE FRONT.
ELSEWHERE...ISOLD SHRA/TSRA ARE EXPECTED THIS AFTN IN THE MTNS OF SW
NC...SC AND GA...AS WELL AS IN THE AREA GENERALLY SOUTH OF I-85. THE
TSRA WILL BE CAPABLE OF VERY GUSTY WINDS AND HAIL. THIS ACTIVITY
WILL BE DIURNALLY DRIVEN AND SHOULD NOT PERSIST INTO THE EVENING.
WINDS GO NORTHERLY OVERNIGHT AS COLD FRONT PUSHES IN. SHOULD REMAIN
TOO DRY FOR FOG EXCEPT PERHAPS IN MTN VALLEYS. THE FRONT MAY HANG UP
OVER THE SAVANNAH RIVER VALLEY AND CAUSE WINDS TO RETURN TO SW AFTER
DAYBREAK AT KAND/KGMU/KGSP. CONFIDENCE ON THIS IS LOW SO NO MENTION
WAS MADE IN THE TAF.
OUTLOOK...DRY HIGH PRESSURE BUILDS IN SATURDAY. VERY ISOLATED
SHRA/TSRA ARE POSSIBLE SAT/SUN AFTNS. AFTN CONVECTION COVERAGE IS
EXPECTED TO INCREASE SOMEWHAT FOR MONDAY AND TUESDAY...AS DEEPER
MOISTURE RETURNS.
CONFIDENCE TABLE...
19-01Z 01-07Z 07-13Z 13-19Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...WIMBERLEY
SHORT TERM...PM
LONG TERM...JPT
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
209 PM EDT FRI MAY 23 2014
.SYNOPSIS...
A COLD FRONT WILL SETTLE SLOWLY SOUTHWARD ACROSS THE REGION TODAY
AND THEN STALL OVER GEORGIA TONIGHT. SURFACE HIGH PRESSURE WILL MOVE
FROM THE OHIO VALLEY TO THE OFFSHORE ATLANTIC WATERS OVER THE
WEEKEND. INSTABILITY AND TEMPERATURES WILL STEADILY REBOUND THROUGH
NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 200 PM EDT...CONVECTION REMAINS MINIMAL ATTM WITH ONLY SCT CU
OVER SOME OF THE MTNS AND WRN UPSTATE. UNDER STILL BRISK MID-UPPER
LEVEL NW FLOW...MTN WAVE CIRRUS CONTINUE TO KEEP MCLDY SKIES OVER
THE NC FOOTHILLS AND NW PIEDMONT. THESE AREAS WERE HIT PRETTY HARD
WITH OUTFLOW FROM THE TSTM CLUSTER THIS MORNING AND APPEAR TO HAVE
BEEN KEPT STABLE BY THIS AND TO SOME EXTENT THE CIRRUS. S AND W OF
THIS AREA WE STILL ANTICIPATE SOME PRECIP ACTIVITY TO GET GOING
DURING THE AFTN...WHERE 1500-2000 J OF UNCAPPED SBCAPE IS SHOWN ON
SPC MESOANALYSIS. THE 12Z NCEP HIRES WINDOW RUNS JUST ARRIVED AND
REINFORCE SUGGESTIONS OF NUMEROUS HRRR AND RAP RUNS THAT ISOLD
ACTIVITY WILL KICK OFF IN THE SMOKIES AND IN THE UPSTATE EAST OF
SPARTANBURG. WITH THE AFOREMENTIONED INSTABILITY AND EFFECTIVE BULK
SHEAR OF 35-45 KT...ALONG WITH SUBSTANTIAL DCAPE OVER 1000
J/KG...STORMS WILL BE QUITE CAPABLE OF DMGG WIND/HAIL.
HIGH PRESSURE BEGINS TO BUILD ACRS THE GREAT LAKES AND OHIO VALLEY
THRU TONIGHT. COLD FRONT CONTINUES TO BE PROGGED TO PUSH SWD THRU
MOST OF THE NC MTNS AND PIEDMONT BY DAYBREAK...PUSHING THROUGH THE
ERN SC PIEDMONT THEREAFTER. IN THE WAKE OF THE FRONT THINGS REMAIN
STABLE THROUGH THE DAY. HOWEVER...WITH A FAIRLY FLAT UPPER RIDGE
REMAINING OVER THE GULF STATES...THE FRONT DOES NOT APPEAR TO FULLY
IMPACT THE SAVANNAH RIVER VALLEY AND WRN UPSTATE. HOWEVER SUBSIDENCE
ALOFT APPEARS TO BE ENOUGH TO WEAKEN LAPSE RATES TO THE POINT THAT
ONLY LIMITED CONVECTION WILL BE POSSIBLE IN THIS AREA. GFS AND NAM
CONTINUE TO PRODUCE HEFTY SBCAPE VALUES OVER 1000 J/KG WEST OF
GSP...BUT SREF PROBS SUGGEST VALUES MOST LIKELY WILL NOT GET THIS
HIGH. I WILL INCLUDE A SCHC FOR DIURNAL SHWRS/TSTMS ALONG THE SRN
ESCARPMENT AND AREAS JUST SOUTH WHERE THE BEST INSTABILITY IS
SUGGESTED.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 230 AM FRIDAY...A SEMI PERSISTENT RIDGE AXIS OVER THE MID
SOUTH AND LOWER MS RIVER VALLEY WILL KEEP NW FLOW ALOFT OVER THE
REGION SAT THROUGH MON. SOME DEGREE OF DRYING SHOULD SETTLE IN
FROM THE N ON SAT AS A SFC COLD FRONT MOVES TO THE SRN PERIPHERY
OF THE FORECAST AREA. HOWEVER...LINGERING MOISTURE IS EXPECTED
ACROSS SW SECTIONS...AND AN INVERTED SFC TROUGH NEAR THE SRN
APPALACHIANS AND UPPER SAVANNAH RIVER AREA WILL PROVIDE WEAK
FORCING. THIS MAY TRIGGER MAINLY DIURNAL ISOLD TO SCT CONVECTION
THROUGH THE WEEKEND...WITH BETTER COVERAGE DEVELOPING BY MON AFTN
AS INSTABILITY REBOUNDS. TEMPERATURES WILL BE NEAR CLIMO EARLY IN
THE PERIOD...RISING TO SLIGHTLY ABOVE CLIMO BY MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 145 PM FRIDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON
TUESDAY WITH THE PERSISTENT UPPER RIDGE ANCHORED OVER THE CENTRAL
CONUS AND AN EMBEDDED H5 LOW DRIFTING SLOWLY EASTWARD OVER THE
SOUTHERN PLAINS. SIMULTANEOUSLY...A CLOSED UPPER LOW IS EXPECTED TO
DROP DOWN OVER EXTREME NORTHERN NEW ENGLAND AND REMAIN OVER THAT
REGION FOR MOST OF THE PERIOD. IN TERMS OF THE SYNOPTIC PATTERN
EVOLUTION OVER OUR REGION...WE DONT EXPECT ANY SIG CHANGES THRU DAY
7 WITH THE DOMINANT UPPER RIDGE REMAINING IN PLACE THRU THE PERIOD.
AT THE SFC...WE BEGIN THE PERIOD UNDER LIGHT SLY FLOW WITH A TYPICAL
BERMUDA HIGH IN PLACE TO OUR EAST. EARLY IN THE DAY...A FAIRLY
ROBUST LOW DEEPENS OVER EXTREME NORTHERN NEW ENGLAND AND BRINGS A
SWATH OF COOLER AND DRIER AIR TOWARDS THE FCST AREA. THE MODELS
DIFFER ON HOW FAR SOUTH THIS LOW WILL MAKE WITH THE GFS BRINGING IT
QUITE A BIT FARTHER SOUTH THAN THE ECMWF AND CMC MODELS. I WILL
CONTINUE TO PUT MORE EMPHASIS ON THE ECMWF AND CMC SOLUTIONS FOR THE
TIME BEING AND THUS I DONT EXPECT THE COOLER/DRIER AIR TO PENETRATE
AS FAR SOUTH AS THE GFS SUGGESTS. ONCE THIS LOW MOVES WELL
OFFSHORE...ANOTHER CANADIAN HIGH TRIES TO PUSH SOUTHWARD AND INTO
THE REGION...HOWEVER ITS LOOKING LIKE IT WILL DISSIPATE FAIRLY QUICKLY
ONCE IT MAKES TO THE CAROLINAS.
AT ANY RATE...NO MAJOR CHANGES WERE NEEDED TO THE SENSIBLE FCST. I
DID INCREASE POPS OVER SOME PORTIONS OF THE CWFA TO SOLID CHANCE FOR
WIDELY SCT DIURNAL SHOWERS AND TS FOR WED AND THURS. OTHERWISE...I
CARRY A SLIGHT TO SOLID CHANCE FOR SH AND TS EACH DAY OF THE PERIOD.
IN ADDITION...IT IS TOO EARLY TO MENTION ANY THREAT OF SVR OR WELL
ORGANIZED CONVECTION AT THIS POINT. TEMPS SHOULD START OUT 5 TO 10
DEGREES ABOVE NORMAL FOR LATE MAY AND GRADUALLY DROP THRU THE PERIOD
WITH HIGHS RIGHT AROUND NORMAL BY NEXT FRIDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...FOLLOWING THE CONVECTION WHICH MOVED THRU THIS MORNING AND
LEFT BEHIND COOLER AND MORE STABLE AIR...THREAT OF TSRA THIS AFTN
APPEARS TO HAVE BEEN MITIGATED TO THE POINT THAT A TEMPO IS NO
LONGER WARRANTED. HOWEVER...THERE IS STILL A VERY SMALL CHANCE A
STORM COULD AFFECT THE FIELD WITH GUSTY WINDS AND POSSIBLY HAIL. A
FEW LOW VFR CU ARE LIKELY TO PERSIST AT ANY RATE. GENERALLY NW WINDS
WILL PRECEDE OVERNIGHT ARRIVAL OF BACKDOOR COLD FRONT...WHICH SHOULD
BRING WINDS N TO NNE AND VIRTUALLY CLEAR SKIES. PROFILES LOOK
UNFAVORABLE FOR FOG WITH LLVL DRYING IN THE WAKE OF THE FRONT.
ELSEWHERE...ISOLD SHRA/TSRA ARE EXPECTED THIS AFTN IN THE MTNS OF SW
NC...SC AND GA...AS WELL AS IN THE AREA GENERALLY SOUTH OF I-85. THE
TSRA WILL BE CAPABLE OF VERY GUSTY WINDS AND HAIL. THIS ACTIVITY
WILL BE DIURNALLY DRIVEN AND SHOULD NOT PERSIST INTO THE EVENING.
WINDS GO NORTHERLY OVERNIGHT AS COLD FRONT PUSHES IN. SHOULD REMAIN
TOO DRY FOR FOG EXCEPT PERHAPS IN MTN VALLEYS. THE FRONT MAY HANG UP
OVER THE SAVANNAH RIVER VALLEY AND CAUSE WINDS TO RETURN TO SW AFTER
DAYBREAK AT KAND/KGMU/KGSP. CONFIDENCE ON THIS IS LOW SO NO MENTION
WAS MADE IN THE TAF.
OUTLOOK...DRY HIGH PRESSURE BUILDS IN SATURDAY. VERY ISOLATED
SHRA/TSRA ARE POSSIBLE SAT/SUN AFTNS. AFTN CONVECTION COVERAGE IS
EXPECTED TO INCREASE SOMEWHAT FOR MONDAY AND TUESDAY...AS DEEPER
MOISTURE RETURNS.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...HG
NEAR TERM...WIMBERLEY
SHORT TERM...HG
LONG TERM...JPT
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
553 PM CDT FRI MAY 23 2014
.DISCUSSION...
SEE 00Z AVIATION DISCUSSION.
&&
.AVIATION...
CIRRUS DEBRIS FROM CONVECTION OVER WEST TEXAS WILL MOVE OVER SE TX
THIS EVENING. MODELS QUITE AGGRESSIVE WITH LOW CLOUDS OVERNIGHT
BUT LEANED A BIT TOWARD THE HRRR WHICH KEEPS THINGS MAINLY VFR
THROUGH 12Z WITH A BRIEF WINDOW OF MVFR CIGS BETWEEN 12-16Z SAT
MORNING. GENERALLY VFR CONDS EXPECTED SAT AFTN/EVENING. 43
&&
.PREV DISCUSSION... /ISSUED 332 PM CDT FRI MAY 23 2014/
DISCUSSION...
WESTERN TROF MAKING SLOW BUT GRADUAL EASTWARD PROGRESS AND SHOULD
CONTINUE DOING SO FOR THE NEXT SEVERAL DAYS. AREA WX SHOULD REMAIN
ABOUT THE SAME THRU THE WEEKEND AND WE`LL MOSTLY BE UNDER THE
INFLUENCE OF THE WESTERN PERIPHERY OF THE RIDGE AND DRIER AIR
SITUATED TO OUR EAST. BUT AS THE TROF MAKES FURTHER EWD THEN SEWD
PROGRESS (OK/TX PANHANDLE MON, OK TUE, TEXARKANA WED, TX/LA BORDER
THURS) EXPECT PW`S TO CLIMB AND THE REGION TO FALL MORE UNDER THE
INFLUENCE OF THE TROF. ECMWF HAS ACTUALLY TRENDED MORE TO THE GFS
SOLN FOR A CHANGE AND THE MODELS ARE ACTUALLY IN PRETTY GOOD AGREEMENT.
ASSUMING THIS VERIFIES IT LOOKS LIKE SCT SHRA/TSRA WILL BE A
DAILY POSSIBILITY INLAND - MORE ISOLATED COAST MON AFTN AND BEYOND.
THOUGH IMPULSES ROTATING AROUND THE TROF COULD REMAIN TRIGGERS AT
ANY TIME, BASED ON TIMING & LOOKS OF QPF FIELDS MOST LOOKS DIURNALLY
DRIVEN W/ DAYTIME HEATING & SEABREEZE BEING PRIMARY TRIGGERS. NUDGED
POPS UP SLIGHTLY ACROSS N-NE 2/3 OF THE CWA NEXT WEEK. WILL PROBABLY
NEED TO CONTINUE TWEAKING UP WITH MODEL CONSISTENCY/CONFIDENCE IN
THE DAYS TO COME.
REGARDING TONIGHT`S CAMELOPARDALIDS METEOR SHOWER:
EXPECT VARIABLE PERIODS OF CIRRUS MOVING OVERHEAD TONIGHT.
HOWEVER...WE`RE NOT EXPECTING QUITE AS MUCH SHRA/TSRA ACTIVITY TO
OUR WEST COMPARED TO LAST NIGHT SO DON`T EXPECT IT TO BE AS THICK
AND MAY QUITE POSSIBLY SEE SOME BREAKS. NASA WEBSITE SAYS PEAK
VIEWING WILL BE BETWEEN 1-3 AM CDT, BUT SHOULD BE ABLE TO SEE SOME
SEVERAL HOURS BEFORE & AFTER THOSE TIMES IF CLOUD COVER COOPERATES.
47
CLIMATE...
THE AVERAGE TEMPERATURE FOR MAY AT THE FIRST-ORDER CLIMATE SITES
CONTINUED TO BE BELOW NORMAL THROUGH YESTERDAY...MAY 22ND. IF THIS
TREND PERSISTS THROUGH THE END OF THE MONTH...BELOW NORMAL MONTHLY
AVERAGE TEMPERATURES WILL HAVE BEEN RECORDED FOR 8 MONTHS IN A ROW
AT COLLEGE STATION AND THE CITY OF HOUSTON...AND FOR 7 MONTHS IN A
ROW AT BOTH THE CITY OF GALVESTON AND HOBBY AIRPORT. THE LAST TIME
HOUSTON RECORDED EIGHT CONSECUTIVE MONTHS WITH BELOW NORMAL TEMPS
WAS JUN 1975 THROUGH JAN 1976.
HERE ARE THE MONTHLY AVERAGE TEMPERATURE DEPARTURES FOR OCTOBER 2013
THROUGH APRIL 2014 AND FOR MAY 1ST THROUGH 22ND...
SITE OCT NOV DEC JAN FEB MAR APR MAY 1-22
IAH -0.2 -4.2 -3.0 -3.6 -1.7 -3.9 -0.1 -2.7
GLS +0.4 -4.1 -4.0 -3.2 -3.2 -3.3 -0.7 -2.7
CLL -0.2 -4.3 -3.7 -3.4 -2.5 -4.6 -0.3 -2.7
HOU +0.5 -3.8 -2.9 -3.0 -1.4 -3.4 -0.2 -3.1
40
MARINE...
ONSHORE WINDS WILL PERSIST WITH HIGH PRESSURE TO THE EAST OVER THE
NORTHERN GULF AND LOW PRESSURE IN THE PLAINS TO THE WEST. AM
EXPECTING AT LEAST ISOLATED SHOWERS AND THUNDERSTORMS TO BEGIN ON
MONDAY OVER THE COASTAL WATERS AND BAYS. 40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 67 87 68 86 70 / 10 10 10 10 10
HOUSTON (IAH) 68 87 69 86 71 / 10 10 10 10 10
GALVESTON (GLS) 73 82 73 82 74 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...23
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
214 PM EDT FRI MAY 23 2014
.SYNOPSIS...
A COLD FRONT WILL SLIDE SOUTH OF THE AREA TODAY. HIGH PRESSURE
BUILDS IN BEHIND THE FRONT BRINGING A RETURN TO DRIER AND SLIGHTLY
COOLER WEATHER FOR THE WEEKEND. THE HIGH MOVES OFFSHORE BY MONDAY
IN ADVANCE OF ANOTHER COLD FRONT THAT WILL DROP SOUTH INTO THE
REGION BY MIDWEEK...RESULTING IN BETTER CHANCES FOR SHOWERS AND
STORMS TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1215 PM EDT FRIDAY...
LIGHT SHOWER ACTIVITY CONTINUES TO DEVELOP ALONG THE 850MB COLD
FRONT...WHICH IS MAKING ITS WAY SOUTH FROM NEAR THE VIRGINIA
NORTH CAROLINA BORDER THIS AFTERNOON. THE HRRR FORECAST MODEL HAS
BEEN HANDLING THE SHOWER ACTIVITY BEST THIS MORNING...AND WILL GO
WITH ITS CALL FOR THE BOUNDARY AND ASSOCIATED RAINFALL TO PUSH
INTO CENTRAL NORTH CAROLINA BY MID AFTERNOON. EXPECT THAT ONCE
THIS ACTIVITY MOVES OUT...OUR AREA WILL REMAIN DRY FOR THE REST
OF THE DAY.
THE OTHER CONCERN FOR TODAY WILL BE HIGH CLOUDS MOSTLY SOUTH OF
HIGHWAY 460. SATELLITE IMAGERY AS OF NOON INDICATES THE CIRRUS MAY
FINALLY BE ERODING FROM WEST TO EAST...BUT THAT IT WILL STILL TAKE
A COUPLE HOURS ACROSS THE VA SOUTHSIDE AND NC PIEDMONT FOR SOLID
SUNSHINE TO REACH THE SURFACE THERE. SINCE TEMPERATURES ALSO CAME
DOWN A FEW DEGREES AS SHOWER ACTIVITY PASSED ACROSS THERE...
LOWERED AFTERNOON HIGHS BY SEVERAL DEGREES TO THE UPPER 70S IN
THIS AREA. OUTSIDE OF THESE CLOUDS...TEMPERATURES STILL LOOK TO BE
ON TRACK TO REACH THE HIGHS FORECAST EARLY THIS MORNING.
WEAK/COOL HIGH PRESSURE WILL BUILD IN FROM THE NW OVERNIGHT BUT
THE CENTER WILL REMAIN WELL TO THE WEST THROUGH DAYBREAK. THIS
SHOULD MAKE FOR MAINLY CLEAR SKIES OUTSIDE OF CIRRUS AND PERHAPS
SOME LOW CLOUDS SPILLING BACK SOUTH AS ANOTHER UPPER LEVEL
DISTURBANCE ROTATES DOWN ON THE BACK OF THE EXITING UPPER SYSTEM
TO THE EAST. THIS WOULD MAINLY AFFECT SE WV LATE AND POSSIBLY THE
EXTREME NORTH GIVEN MORE OF A NORTHERLY TRAJECTORY. HOWEVER GIVEN
DRY AIR WILL ONLY INCLUDE MORE CLOUDS OVER THE FAR NW AT THIS
POINT. EXPECT A WEAK GRADIENT TO REMAIN IN PLACE OVERNIGHT BUT
LIKELY NOT ENOUGH TO KEEP THE VALLEYS FROM DECOUPLING AND DROPPING
WELL INTO THE 40S. ELSW WILL GO ON THE WARM SIDE OF MOS ESPCLY
BLUE RIDGE EAST WHERE LIKELY TO STAY CLOSE TO IF NOT ABOVE 50 FOR
LOWS WITH A LIGHT BREEZE.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 315 AM EDT FRIDAY...
MEMORIAL HOLIDAY WEEKEND LOOKING GOOD WITH MAINLY DRY AND
SEASONABLY WARM CONDITIONS.
HIGH PRESSURE WILL BUILD SOUTHEAST INTO OUR REGION SATURDAY.
NORTHWEST WINDS SHOULD STEADILY DIMINISH DURING THE DAY AS THE
OVERHEAD PRESSURE GRADIENT SLACKENS. HIGH TEMPERATURES SATURDAY
WILL RANGE FROM THE UPPER 60S IN THE NORTHWEST MOUNTAINS TO
AROUND 80 DEGREES IN THE PIEDMONT.
COOL FOR SATURDAY NIGHT WITH GOOD RADIATIONAL COOLING RESULTING
IN LOW TEMPERATURES FROM THE MID 40S IN THE MOUNTAINS TO THE MID
50S IN THE PIEDMONT. THE AREA OF HIGH PRESSURE WILL MOVE SOUTHEAST
INTO THE ATLANTIC OCEAN ON SUNDAY. LEANED TOWARDS THE ECMWF WITH
THE SLOWER RETURN OF MOISTURE AROUND THE HIGH CENTER COMPARED TO
GFS. AN ISOLATED SHOWER OR THUNDERSTORM MAY BE POSSIBLE ACROSS THE
HIGHER TERRAIN OF WESTERN NORTH CAROLINA LATE SUNDAY
AFTERNOON...BUT IT APPEARS THAT IT WILL BE TOO FAR SOUTH TO
ADVERTISE ANY POPS IN THE CWA. HIGH TEMPERATURES ON SUNDAY WILL
RANGE FROM THE MID 70S IN THE MOUNTAINS TO THE LOWER 80S IN THE
SOUTHEAST.
AS HIGH PRESSURE DEPARTS OFF THE COAST ON SUNDAY NIGHT...AN
UPPER LEVEL RIDGE SHOULD BUILD OVER THE SOUTHEAST US. USED
ENSEMBLE BLEND FOR LOWS TEMPERATURES SUNDAY NIGHT WITH READINGS
FROM AROUND 50 IN THE WEST TO THE UPPER 50S IN THE EAST.
A VERY TYPICAL MEMORIAL DAY EXPECTED...AS THE RETURN SOUTHERLY
FLOW ADVECTS WARM AND MOIST AIR TOWARD THE MID ATLANTIC. BOTH THE
ECWMF AND GFS INDICATED ISOLATED CONVECTIVE ACTIVITY OVER SOUTHERN
PORTIONS OF FORECAST AREA ESPECIALLY OVER THE SOUTHERN BLUE RIDGE
DURING THE AFTERNOON. LEANED TEMPERATURES MONDAY TOWARDS HPCGUIDE
WITH HIGHS FROM MID 70S IN THE WEST TO THE MID 80S IN THE EAST.
LOW TEMPERATURES MONDAY NIGHT WILL RANGE FROM THE MID 50S IN THE
MOUNTAINS TO THE LOWER 60S IN THE PIEDMONT.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
A SECOND UPPER LEVEL LOW WILL DROP SOUTHWARD TUESDAY OVER THE
NORTHEAST CONUS. THIS WILL DRAPE A COLD FRONT ACROSS THE OHIO
RIVER VALLEY...AND INCREASE THE CHANCES FOR MORE WIDESPREAD
SHOWERS AND THUNDERSTORMS OVER THE CWA FUELED BY DIURNAL HEATING
DURING TUESDAY AND WEDNESDAY. THE MODELS SEEM TO EMPHASIZE THE
WESTERN BLUE RIDGE FOR THE HIGHEST POPS...BUT IT MAY BE POSSIBLE
TO SEE SOME STORMS SPILL OVER TOWARD THE PIEDMONT. THE FRONT SAGS
SOUTHWARD TOWARD THE CAROLINAS BY THURSDAY...WITH MAYBE AN
ISOLATED THREAT OF THUNDERSTORMS OVER THE WESTERN NORTH CAROLINA
MOUNTAINS. BECAUSE OF THE INCREASED CLOUD COVER LATER IN THIS
FORECAST PERIOD...HIGH TEMPERATURES FOR WEDNESDAY AND THURSDAY
WERE KEPT SLIGHTLY COOLER THAN THE WARMER MAV GUIDANCE.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 200 PM EDT FRIDAY...
COLD FRONT HAS SHIFTED SOUTH OF ALL TAF SITES THIS AFTERNOON...
WITH VFR CONDITIONS REPORTED AREAWIDE PER SURFACE OBSERVATIONS.
STILL KEEPING AN EYE ON THE 850MB COOL FRONT MOVING ACROSS
NORTHERN NORTH CAROLINA...WITH THE ASSOCIATED RAIN SHOWER ACTIVITY
EXPECTED TO EXIT THE AREA EARLY THIS AFTERNOON. ACROSS CENTRAL
VIRGINIA...OBSERVING FEW TO SCT CU FIELD DEVELOPING WITH AFTERNOON
HEATING...WITH A WEST-NORTHWEST WIND GUSTING 15KT TO 20KT ACROSS
THE MOUNTAINS.
HIGH PRESSURE WILL SLIDE VERY SLOWLY TO THE EAST ACROSS THE
SOUTHERN GREAT LAKES THROUGH SATURDAY AFTERNOON...GRADUALLY
SHIFTING WINDS MORE NORTHERLY AS IT PROGRESSES. WITH MOSTLY CLEAR
SKIES UNDER PASSING CIRRUS OVERNIGHT...EXPECT WINDS TO DECOUPLE...
DROPPING SPEEDS TO 3KT TO 5KT. MAY SEE SOME VALLEY FOG DEVELOP...
ESPECIALLY AT KLWB...WHICH WILL LOCALLY DROP VISIBILITIES TO 1/4SM
OR LESS. SOME PATCHY FOG ALSO POSSIBLE AT KBCB AND PERHAPS KLYH
BUT GIVEN LOWERING DEWPOINTS/DRYING...WILL LEAVE OUT MENTION AT
THESE SPOTS FOR NOW. ANY FOG WILL DISSIPATE QUICKLY AFTER 13Z.
EXTENDED AVIATION DISCUSSION...
OVERALL...VFR CONDITIONS ARE EXPECTED SATURDAY THROUGH MONDAY
WITH SOME INCREASING POTENTIAL FOR EARLY MORNING MVFR FOG AT
KLWB/KLYH/KBCB. ISOLATED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS ARE POSSIBLE LATER MONDAY...WITH INCREASING COVERAGE
TUESDAY...ESPECIALLY OVER THE MOUNTAINS AS HIGH PRESSURE MOVES
OFFSHORE...AND DEEPER MOISTURE RETURNS AHEAD OF AN APPROACHING
COLD FRONT FROM THE NORTH.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF/WP
NEAR TERM...JH/NF
SHORT TERM...KK
LONG TERM...AMS/PW
AVIATION...JH/NF
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1226 PM EDT FRI MAY 23 2014
.SYNOPSIS...
A COLD FRONT WILL SLIDE SOUTH OF THE AREA TODAY. HIGH PRESSURE
BUILDS IN BEHIND THE FRONT BRINGING A RETURN TO DRIER AND SLIGHTLY
COOLER WEATHER FOR THE WEEKEND. THE HIGH MOVES OFFSHORE BY MONDAY
IN ADVANCE OF ANOTHER COLD FRONT THAT WILL DROP SOUTH INTO THE
REGION BY MIDWEEK...RESULTING IN BETTER CHANCES FOR SHOWERS AND
STORMS TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1215 PM EDT FRIDAY...
LIGHT SHOWER ACTIVITY CONTINUES TO DEVELOP ALONG THE 850MB COLD
FRONT...WHICH IS MAKING ITS WAY SOUTH FROM NEAR THE VIRGINIA
NORTH CAROLINA BORDER THIS AFTERNOON. THE HRRR FORECAST MODEL HAS
BEEN HANDLING THE SHOWER ACTIVITY BEST THIS MORNING...AND WILL GO
WITH ITS CALL FOR THE BOUNDARY AND ASSOCIATED RAINFALL TO PUSH
INTO CENTRAL NORTH CAROLINA BY MID AFTERNOON. EXPECT THAT ONCE
THIS ACTIVITY MOVES OUT...OUR AREA WILL REMAIN DRY FOR THE REST
OF THE DAY.
THE OTHER CONCERN FOR TODAY WILL BE HIGH CLOUDS MOSTLY SOUTH OF
HIGHWAY 460. SATELLITE IMAGERY AS OF NOON INDICATES THE CIRRUS MAY
FINALLY BE ERODING FROM WEST TO EAST...BUT THAT IT WILL STILL TAKE
A COUPLE HOURS ACROSS THE VA SOUTHSIDE AND NC PIEDMONT FOR SOLID
SUNSHINE TO REACH THE SURFACE THERE. SINCE TEMPERATURES ALSO CAME
DOWN A FEW DEGREES AS SHOWER ACTIVITY PASSED ACROSS THERE...
LOWERED AFTERNOON HIGHS BY SEVERAL DEGREES TO THE UPPER 70S IN
THIS AREA. OUTSIDE OF THESE CLOUDS...TEMPERATURES STILL LOOK TO BE
ON TRACK TO REACH THE HIGHS FORECAST EARLY THIS MORNING.
WEAK/COOL HIGH PRESSURE WILL BUILD IN FROM THE NW OVERNIGHT BUT
THE CENTER WILL REMAIN WELL TO THE WEST THROUGH DAYBREAK. THIS
SHOULD MAKE FOR MAINLY CLEAR SKIES OUTSIDE OF CIRRUS AND PERHAPS
SOME LOW CLOUDS SPILLING BACK SOUTH AS ANOTHER UPPER LEVEL
DISTURBANCE ROTATES DOWN ON THE BACK OF THE EXITING UPPER SYSTEM
TO THE EAST. THIS WOULD MAINLY AFFECT SE WV LATE AND POSSIBLY THE
EXTREME NORTH GIVEN MORE OF A NORTHERLY TRAJECTORY. HOWEVER GIVEN
DRY AIR WILL ONLY INCLUDE MORE CLOUDS OVER THE FAR NW AT THIS
POINT. EXPECT A WEAK GRADIENT TO REMAIN IN PLACE OVERNIGHT BUT
LIKELY NOT ENOUGH TO KEEP THE VALLEYS FROM DECOUPLING AND DROPPING
WELL INTO THE 40S. ELSW WILL GO ON THE WARM SIDE OF MOS ESPCLY
BLUE RIDGE EAST WHERE LIKELY TO STAY CLOSE TO IF NOT ABOVE 50 FOR
LOWS WITH A LIGHT BREEZE.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 315 AM EDT FRIDAY...
MEMORIAL HOLIDAY WEEKEND LOOKING GOOD WITH MAINLY DRY AND
SEASONABLY WARM CONDITIONS.
HIGH PRESSURE WILL BUILD SOUTHEAST INTO OUR REGION SATURDAY.
NORTHWEST WINDS SHOULD STEADILY DIMINISH DURING THE DAY AS THE
OVERHEAD PRESSURE GRADIENT SLACKENS. HIGH TEMPERATURES SATURDAY
WILL RANGE FROM THE UPPER 60S IN THE NORTHWEST MOUNTAINS TO
AROUND 80 DEGREES IN THE PIEDMONT.
COOL FOR SATURDAY NIGHT WITH GOOD RADIATIONAL COOLING RESULTING
IN LOW TEMPERATURES FROM THE MID 40S IN THE MOUNTAINS TO THE MID
50S IN THE PIEDMONT. THE AREA OF HIGH PRESSURE WILL MOVE SOUTHEAST
INTO THE ATLANTIC OCEAN ON SUNDAY. LEANED TOWARDS THE ECMWF WITH
THE SLOWER RETURN OF MOISTURE AROUND THE HIGH CENTER COMPARED TO
GFS. AN ISOLATED SHOWER OR THUNDERSTORM MAY BE POSSIBLE ACROSS THE
HIGHER TERRAIN OF WESTERN NORTH CAROLINA LATE SUNDAY
AFTERNOON...BUT IT APPEARS THAT IT WILL BE TOO FAR SOUTH TO
ADVERTISE ANY POPS IN THE CWA. HIGH TEMPERATURES ON SUNDAY WILL
RANGE FROM THE MID 70S IN THE MOUNTAINS TO THE LOWER 80S IN THE
SOUTHEAST.
AS HIGH PRESSURE DEPARTS OFF THE COAST ON SUNDAY NIGHT...AN
UPPER LEVEL RIDGE SHOULD BUILD OVER THE SOUTHEAST US. USED
ENSEMBLE BLEND FOR LOWS TEMPERATURES SUNDAY NIGHT WITH READINGS
FROM AROUND 50 IN THE WEST TO THE UPPER 50S IN THE EAST.
A VERY TYPICAL MEMORIAL DAY EXPECTED...AS THE RETURN SOUTHERLY
FLOW ADVECTS WARM AND MOIST AIR TOWARD THE MID ATLANTIC. BOTH THE
ECWMF AND GFS INDICATED ISOLATED CONVECTIVE ACTIVITY OVER SOUTHERN
PORTIONS OF FORECAST AREA ESPECIALLY OVER THE SOUTHERN BLUE RIDGE
DURING THE AFTERNOON. LEANED TEMPERATURES MONDAY TOWARDS HPCGUIDE
WITH HIGHS FROM MID 70S IN THE WEST TO THE MID 80S IN THE EAST.
LOW TEMPERATURES MONDAY NIGHT WILL RANGE FROM THE MID 50S IN THE
MOUNTAINS TO THE LOWER 60S IN THE PIEDMONT.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
A SECOND UPPER LEVEL LOW WILL DROP SOUTHWARD TUESDAY OVER THE
NORTHEAST CONUS. THIS WILL DRAPE A COLD FRONT ACROSS THE OHIO
RIVER VALLEY...AND INCREASE THE CHANCES FOR MORE WIDESPREAD
SHOWERS AND THUNDERSTORMS OVER THE CWA FUELED BY DIURNAL HEATING
DURING TUESDAY AND WEDNESDAY. THE MODELS SEEM TO EMPHASIZE THE
WESTERN BLUE RIDGE FOR THE HIGHEST POPS...BUT IT MAY BE POSSIBLE
TO SEE SOME STORMS SPILL OVER TOWARD THE PIEDMONT. THE FRONT SAGS
SOUTHWARD TOWARD THE CAROLINAS BY THURSDAY...WITH MAYBE AN
ISOLATED THREAT OF THUNDERSTORMS OVER THE WESTERN NORTH CAROLINA
MOUNTAINS. BECAUSE OF THE INCREASED CLOUD COVER LATER IN THIS
FORECAST PERIOD...HIGH TEMPERATURES FOR WEDNESDAY AND THURSDAY
WERE KEPT SLIGHTLY COOLER THAN THE WARMER MAV GUIDANCE.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
AS OF 635 AM EDT FRIDAY...
WEAK COOL FRONT SLIDING SOUTH INTO NORTHERN NORTH CAROLINA ATTM
SHOULD CONTINUE SOUTH OF THE REGION THIS MORNING. MID LEVEL
MOISTURE ALONG AND NORTH OF THE FRONT MAY BRING A FEW
-SHRA/SPRINKLES TO THE KBLF/KBCB CORRIDOR EARLY. OTRW NEXT WAVE
APPROACHING FROM EASTERN TN SHOULD MISS MOST OF THE TAF SITES THIS
MORNING BEFORE WEAKENING WITH MUCH THIS PRECIP MOSTLY AFFECTING
SPOTS FROM KMKJ TO KTNB IF AT ALL. THIS FEATURE MAY ACT TO
PRODUCE PERIODS OF MVFR CIGS AT KBLF THIS MORNING WITH SOME PATCHY
FOG POSSIBLE AROUND KLWB FOR AN HOUR OR TWO. EXPECT ANY MVFR
CIGS/VSBYS WILL BECOME VFR WITH ONLY SCTD CU AND RESIDUAL HIGH/MID
CLOUDS AFTER 14-15Z WITH ANOTHER BREEZY AFTERNOON IN
STORE...UNDER WEST/NW WINDS GUSTING 20-25 KNOTS.
WEAK HIGH PRESSURE BUILDS IN OVERNIGHT WITH VFR CONDITIONS FOR THE
MOST PART. HOWEVER MVFR/IFR CIGS MAY DEVELOP AROUND KLWB LATE AS
LOW CLOUDS SPIN BACK SOUTH AND DENSE FOG/STRATUS TAKE SHAPE IF
A LONGER PERIOD OF CLEARING IS SEEN OVERNIGHT. SOME PATCHY FOG
ALSO POSSIBLE AT KBCB AND PERHAPS KLYH BUT GIVEN LOWERING
DEWPOINTS/DRYING LEAVING OUT MENTION AT THESE SPOTS FOR NOW.
EXTENDED AVIATION DISCUSSION...
OVERALL...VFR CONDITIONS ARE EXPECTED SATURDAY THROUGH MONDAY
WITH SOME INCREASING POTENTIAL FOR EARLY MORNING MVFR FOG AT
KLWB/KLYH/KBCB. ISOLATED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS ARE POSSIBLE LATER MONDAY...WITH INCREASING
COVERAGE TUESDAY...ESPCLY OVER THE MOUNTAINS AS HIGH PRESSURE
MOVES OFFSHORE...AND DEEPER MOISTURE RETURNS AHEAD OF AN
APPROACHING COLD FRONT FROM THE NORTH.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF/WP
NEAR TERM...JH/NF
SHORT TERM...KK
LONG TERM...AMS/PW
AVIATION...JH/NF/WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
542 PM CDT FRI MAY 23 2014
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 242 PM CDT FRI MAY 23 2014
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE
HIGH PRESSURE CENTERED OVER THE STATE OF WISCONSIN EARLY THIS
AFTERNOON AND IS PROVIDING TRANQUIL AND SEASONABLE CONDITIONS.
LOOKING OUTSIDE THE REGION...MID-LEVEL THETAE ADVECTION IS PRODUCING
AN AREA OF CLOUD COVER WHICH IS ENTERING WESTERN LAKE SUPERIOR.
ANOTHER AREA OF HIGH CLOUDS IS SPILLING OVER THE MID-LEVEL RIDGE
CENTERED OVER THE GREAT PLAINS INTO IOWA AND NORTHERN ILLINOIS.
WITH SYNOPTIC SCALE FEATURES ONLY MOVING SLIGHTLY TO THE EAST OVER
THE NEXT 24 HOURS...FORECAST CONCERNS INCLUDE CLOUDS AND TEMPS.
TONIGHT...SURFACE HIGH PRESSURE WILL BECOME CENTERED OVER LAKE
MICHIGAN. MID AND HIGH CLOUDS FROM THE THETAE ADVECTION ZONE OVER
WESTERN LAKE SUPERIOR WILL LIKELY SPILL SOUTHEAST ACROSS NORTHERN
AND FAR NORTHEAST WISCONSIN DURING THE EVENING. HAVE KEPT SKIES
PARTLY CLOUDY IN THIS AREA AS A RESULT WHILE STUCK WITH MOSTLY CLEAR
TO CLEAR ELSEWHERE. STUCK WITH THE BETTER VERIFYING BC GUIDANCE FOR
LOW TEMPS WHICH WILL BE SEVERAL DEGREES WARMER THAN LAST NIGHT.
SATURDAY...SURFACE HIGH PRESSURE WILL MOVE TO THE LOWER PENINSULA OF
MICHIGAN. WINDS WILL SHIFT TO THE SOUTHWEST OVER THE STATE...BUT
THE COOLEST LOW LEVEL TEMPS WILL REMAIN OVER CENTRAL AND EASTERN
WISCONSIN. THEREFORE...EXPECT SCT DIURNAL CU IN THIS AREA AND
SHOULD HAVE A LITTLE MORE CIRRUS OVERHEAD TOO. THIS SHOULD NOT STOP
925MB TEMPS FROM WARMING INTO THE MID TO UPPER TEENS WHICH WOULD
PLACE HIGHS IN THE MID TO UPPER 70S AWAY FROM LAKE MICHIGAN.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 242 PM CDT FRI MAY 23 2014
UPPER RIDGING SHOULD KEEP DRY AND WARM WEATHER ACROSS
THE AREA THROUGH SUNDAY EVENING. A SHORTWAVE MOVING THROUGH THE
NORTHERN STREAM WILL COMBINE WITH LOW LEVEL MOISTURE AND CONVERGENCE
TO BRING SCATTERED SHOWERS AND THUNDERSTORMS LATE SUNDAY NIGHT AND
MEMORIAL DAY. SURFACE DEWPOINTS ARE FORECAST TO RISE INTO THE UPPER
50S TO LOW 60S WHICH RESULTS IN CAPES OF 1000 TO 2000 J/KG. WINDS
ALOFT ARE NOT VERY IMPRESSIVE AND TEMPERATURES ALOFT ARE NOT THAT
COLD. SO WE MAY HAVE A FEW STORMS WITH GUSTY WINDS AND SMALL HAIL
BUT SEVERE STORMS NOT LIKELY AT THIS POINT. A SURFACE FRONT SHOULD
MOVE THROUGH LATE MONDAY NIGHT AND AN UPPER RIDGE GETS ESTABLISHED
OVER THE HIGH PLAINS. A BIG SURFACE HIGH DROPS DOWN FROM ICE COVERED
HUDSON`S BAY INTO THE GREAT LAKES AND SHOULD PRODUCE A DRY EASTERLY
FLOW FROM TUESDAY THROUGH FRIDAY OR SATURDAY.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 541 PM CDT FRI MAY 23 2014
QUIET WX WITH VFR CONDITIONS EXPECTED THE NEXT 24 HRS AS SFC HIGH
LINGERS ACRS THE AREA.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......SKOWRONSKI
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 242 PM CDT FRI MAY 23 2014
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE
HIGH PRESSURE CENTERED OVER THE STATE OF WISCONSIN EARLY THIS
AFTERNOON AND IS PROVIDING TRANQUIL AND SEASONABLE CONDITIONS.
LOOKING OUTSIDE THE REGION...MID-LEVEL THETAE ADVECTION IS PRODUCING
AN AREA OF CLOUD COVER WHICH IS ENTERING WESTERN LAKE SUPERIOR.
ANOTHER AREA OF HIGH CLOUDS IS SPILLING OVER THE MID-LEVEL RIDGE
CENTERED OVER THE GREAT PLAINS INTO IOWA AND NORTHERN ILLINOIS.
WITH SYNOPTIC SCALE FEATURES ONLY MOVING SLIGHTLY TO THE EAST OVER
THE NEXT 24 HOURS...FORECAST CONCERNS INCLUDE CLOUDS AND TEMPS.
TONIGHT...SURFACE HIGH PRESSURE WILL BECOME CENTERED OVER LAKE
MICHIGAN. MID AND HIGH CLOUDS FROM THE THETAE ADVECTION ZONE OVER
WESTERN LAKE SUPERIOR WILL LIKELY SPILL SOUTHEAST ACROSS NORTHERN
AND FAR NORTHEAST WISCONSIN DURING THE EVENING. HAVE KEPT SKIES
PARTLY CLOUDY IN THIS AREA AS A RESULT WHILE STUCK WITH MOSTLY CLEAR
TO CLEAR ELSEWHERE. STUCK WITH THE BETTER VERIFYING BC GUIDANCE FOR
LOW TEMPS WHICH WILL BE SEVERAL DEGREES WARMER THAN LAST NIGHT.
SATURDAY...SURFACE HIGH PRESSURE WILL MOVE TO THE LOWER PENINSULA OF
MICHIGAN. WINDS WILL SHIFT TO THE SOUTHWEST OVER THE STATE...BUT
THE COOLEST LOW LEVEL TEMPS WILL REMAIN OVER CENTRAL AND EASTERN
WISCONSIN. THEREFORE...EXPECT SCT DIURNAL CU IN THIS AREA AND
SHOULD HAVE A LITTLE MORE CIRRUS OVERHEAD TOO. THIS SHOULD NOT STOP
925MB TEMPS FROM WARMING INTO THE MID TO UPPER TEENS WHICH WOULD
PLACE HIGHS IN THE MID TO UPPER 70S AWAY FROM LAKE MICHIGAN.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 242 PM CDT FRI MAY 23 2014
UPPER RIDGING SHOULD KEEP DRY AND WARM WEATHER ACROSS
THE AREA THROUGH SUNDAY EVENING. A SHORTWAVE MOVING THROUGH THE
NORTHERN STREAM WILL COMBINE WITH LOW LEVEL MOISTURE AND CONVERGENCE
TO BRING SCATTERED SHOWERS AND THUNDERSTORMS LATE SUNDAY NIGHT AND
MEMORIAL DAY. SURFACE DEWPOINTS ARE FORECAST TO RISE INTO THE UPPER
50S TO LOW 60S WHICH RESULTS IN CAPES OF 1000 TO 2000 J/KG. WINDS
ALOFT ARE NOT VERY IMPRESSIVE AND TEMPERATURES ALOFT ARE NOT THAT
COLD. SO WE MAY HAVE A FEW STORMS WITH GUSTY WINDS AND SMALL HAIL
BUT SEVERE STORMS NOT LIKELY AT THIS POINT. A SURFACE FRONT SHOULD
MOVE THROUGH LATE MONDAY NIGHT AND AN UPPER RIDGE GETS ESTABLISHED
OVER THE HIGH PLAINS. A BIG SURFACE HIGH DROPS DOWN FROM ICE COVERED
HUDSON`S BAY INTO THE GREAT LAKES AND SHOULD PRODUCE A DRY EASTERLY
FLOW FROM TUESDAY THROUGH FRIDAY OR SATURDAY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1234 PM CDT FRI MAY 23 2014
HIGH PRESSURE WILL BE MOVING ACROSS THE REGION THROUGH THE END OF
THE TAF PERIOD. OTHER THAN CUMULUS BUILD UP DURING THE LATE MORNING
THROUGH END OF THE AFTERNOON HOURS...SKIES WILL REMAIN MOSTLY
CLEAR. DID REMOVE THE MVFR VSBYS LATE TONIGHT SINCE LOW TEMPS ARE
NOT EXPECTED TO FALL BELOW THE CROSS-OVER TEMPERATURE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......MPC